KR20210023927A - A device that uses laser beams to weld opaque and permeable plastics without annealing - Google Patents

Abstract

In a plastic welding device for welding an impermeable first plastic and a transparent second plastic without annealing using a laser beam according to an embodiment of the present invention, the plastic welding device comprises: the first plastic and A second transparent plastic is adhered to each other, and a laser beam is irradiated to the adhered first plastic and the second plastic, and at least a portion of the laser beam is first absorbed while passing through the second plastic, and the first plastic and The remaining beam may be secondly absorbed into the first contact area of the second plastic, and the first contact area may be welded by using the first absorption and the second absorption.

Description

{A device that uses laser beams to weld opaque and permeable plastics without annealing}

The present invention relates to an apparatus for welding an impermeable plastic and a transmissive plastic using a laser beam without an annealing process. Specifically, the present invention relates to an apparatus and method for welding opaque plastics and transmissive plastics without annealing by using a laser beam having a wavelength of 1400 to 3000 nm.

In general, as a method of joining two members made of thermoplastic resin, there is a method of applying an adhesive to any one of the upper and lower members to be joined, or joining through ultrasonic welding or vibration welding.

However, in this method, environmental pollution occurs according to the use of the adhesive, the joint part is not smooth, and the joint strength is not constant, so when an external mechanical force is applied, damage to the inside of the product occurred, and above all, watertightness problems were caused.

Based on this problem, a laser welding method that conducts heat locally and implements a non-contact type at the same time has been proposed.

The laser welding method is to weld and bond the transmissive cover and the edge of the housing with a laser in a state in which the cover and the housing to be welded are in close contact. The laser that has passed through the cover is absorbed from the surface of the housing, and the absorbed laser is It is a method of welding and bonding the housing to the cover by heating and melting the housing at the interface between the cover and the housing.

However, in order to enable laser welding, the upper member and the lower member must be made of the same material. If a member of a different material is to be welded using a laser, since the temperature characteristics according to the material are different, the welding is not completely performed.

That is, as a general laser welding method, it is practically possible to weld a non-transparent housing made of PP, PET, or ABS material to each other as a vehicle lamp made of different materials, that is, a transparent cover made of PC and PMMA materials, and a transparent cover made of PC and PMMA materials, which are fixed to the vehicle body. There was a problem that I didn't.

Further, in the above-described laser welding method, since the laser is absorbed from the surface of the housing after passing through the cover, the surface of the housing sufficiently increases and melts, but the temperature does not rise because the cover is transmitted through the laser.

Therefore, the temperature of the cover is considerably lower than that of the housing, and a large temperature difference occurs, and this temperature difference makes the welding between the housing and the cover not firm and at the same time non-uniform welding quality. Therefore, a phenomenon in which the cover is partially separated from the surface of the housing by the vibration applied while the vehicle is driving has often occurred.

In this case, rain, snow, or external moisture penetrates into the gap between the cover and the housing, causing dew to form in the vehicle lamp, and this dew causes corrosion on the electrodes of the lamp, which shortens the lamp life.

In order to solve the problem caused by such a large temperature difference and to make the welding quality uniform, an annealing process may be applied.

The annealing process is a treatment method in which an alloy hardened by heat treatment is heated at a high temperature for a long time to gradually cool down to room temperature to soften it.In the case of a material in which a phase change occurs as the temperature rises or falls, it is gradually cooled over a sufficient period of time to obtain a stable equilibrium state. Say.

However, when such an annealing process is applied, there is a big problem that a short-circuit process part occurs in the entire welding process, and the manufacturing cost is remarkably increased.

Accordingly, there is a growing need for a technology that enables high-quality welding without annealing process by melting and welding the lower material together while melting the upper transparent material based on the laser beam.

(1) U.S. Patent Application No. 12/382633 (2) U.S. Patent Application No. 12/551837 (3) Japanese Patent Application No. 2016-052587

The present invention has been devised to solve the conventional problems as described above, and an object thereof is to provide a welding device using a laser and a control method thereof to a user.

Specifically, an object of the present invention is to provide a user with an apparatus and method for welding impermeable plastics and transmissive plastics without annealing process using a laser beam having a wavelength of 1400 to 3000 nm.

On the other hand, the technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned are clearly to those of ordinary skill in the technical field to which the present invention belongs from the following description. It will be understandable.

In a plastic welding device for welding an impermeable first plastic and a transparent second plastic without an annealing process using a laser beam according to an embodiment of the present invention for realizing the above-described problem, the plastic welding device Is, the first plastic and the transmissive second plastic are in close contact, the first and second plastics are irradiated with a laser beam, and at least a portion of the laser beam is first absorbed while passing through the second plastic The remaining beam is secondly absorbed into the first contact area of the first plastic and the second plastic, and the first contact area is welded by using the first absorption and the second absorption, and the laser beam is The laser beam having a wavelength range of 1400 to 3000 nm, at least part of the laser beam transmitted through the second plastic is reflected on a reflective surface provided in at least a part of the second plastic, and the reflected laser beam is different from the first contact area. The first and second plastics are absorbed into a second contact area, the first contact area and the second contact area are welded together, and at least a part of the first plastic and the second plastic is bent. If present, the plastic welding device collects first information on the curved part, and the laser beam is irradiated according to the first information before the first plastic and the second plastic are in close contact with each other. Adjust at least one of a focal length, an output value, a speed of the laser beam, and a separation distance between the first plastic and the second plastic, and the first information includes length, height change, and shape information for the curved part. And, by forming an intermediate surface formed with a step having an angle exceeding a critical angle into which the laser beam is introduced on at least a portion of the first plastic and the second plastic, the laser The beam is prevented from entering, and the plastic welding field Chi, before irradiating the laser beam to the first and second plastics, the first and second plastics are further closely contacted using a jig, and the jig is transparent, and the The output of the laser beam may be increased in a region in which the incident angle of the laser beam is equal to or less than a preset value or the incident energy density is increased among the first contact regions.

The present invention has been devised to solve the conventional problems as described above, and a welding device using a laser and a control method thereof can be provided to a user.

Specifically, the present invention can provide a user with an apparatus and method for welding opaque plastics and transmissive plastics without annealing process using a laser beam having a wavelength of 1400 to 3000 nm.

According to the present invention, by omitting the application of the annealing process, there is an effect that the short circuit process part in the entire welding process can be eliminated, and the manufacturing cost can be remarkably reduced.

The laser welding according to the present invention enables plastic bonding with low cost and high efficiency, and as a non-contact welding method, there is no external deformation of the product due to vibration, shock, and heat, and the bonding quality is excellent because no burr or fluff occurs. As it can be applied to products of 2D, 3D shape, regardless of size or shape, automation is easy, and system stability can be provided.

On the other hand, the effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those of ordinary skill in the art from the following description. I will be able to.

The following drawings attached to the present specification illustrate a preferred embodiment of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the present invention, so the present invention is limited to the matters described in such drawings. It is limited and should not be interpreted.
1 shows an example of a welding method using an adhesive, a welding method using vibration, and a welding method using ultrasonic waves that can be used for welding of plastics.
2 shows an example of a schematic diagram of a laser welding process in connection with the present invention.
3 is a diagram illustrating a welding method using a laser in connection with the present invention.
4 shows an example of a block diagram of a welding device using a laser proposed by the present invention.
5 shows an example of using a laser beam in a wavelength band for preheating a transparent cover and a laser beam in another wavelength band for melting a welding boundary between the transparent cover and the non-transmissive housing in connection with the present invention.
6 shows an example of preheating the transmission area of the transparent cover and melting the contact area by irradiating a laser beam having an infrared wavelength band through the edge of the transmissive cover toward the contact area of an adhering housing according to the present invention. I did it.
7 is a table showing the preferred condition values for laser welding to an automobile lamp in relation to the present invention.
8 shows an example of performing welding of a desired area by placing a reflective surface therein in connection with the present invention.
9 illustrates an example of adjusting a focal length, an output value, and the like using height information from a reference point of a curved object based on one laser source in relation to the present invention.
10A and 10B illustrate an example of forming a welding surface such that a lower surface of a transparent plastic contacting an opaque plastic has an angle perpendicular to the jig.
11 shows an example of preventing laser inflow into the interior by forming an intermediate surface between the welding surface and the transmitting part and forming an angle exceeding a critical angle with respect to the laser according to the present invention.
12 shows an example of increasing the degree of adhesion by applying a pressing jig transparently and allowing the laser to reach through the jig in connection with the present invention.
13 shows an example in which the welder protruding from the housing is inserted into the mounting portion formed on the resin cover to be welded, thereby maintaining a close contact without a separate jig.
14A to 14D are graphs for explaining the laser welding market related to the present invention.

Conventional technology used for plastic welding

1 shows an example of a welding method using an adhesive, a welding method using vibration, and a welding method using ultrasonic waves that can be used for welding of plastics.

The adhesive method shown in (a) of FIG. 1 requires an adhesive, which is a third material to connect the parts of the joined joint.

The adhesive method is a very efficient bonding method that permanently 　 bonds to a material 　, and a visible/ultraviolet curing adhesive is widely used.

The vibration welding method shown in FIG. 1(b) is a method of diffusing plastic melt while lateral vibration friction and pressure are applied according to frequency and amplitude.

The vibration welding method. It is mainly used for plastic products that require internal pressure and high strength, and is mainly used for welding of crystalline resins and engineering plastics.

In addition, the ultrasonic welding method shown in (c) of FIG. 1 is based on thermal conversion of friction and vibration energy.

In the ultrasonic welding method, high-frequency vibrations are transmitted together with pressure to the parts to be joined.

In the ultrasonic welding method, fine melting due to frictional heat occurs at the vibration interface.

However, such a welding method using an adhesive, a welding method using vibration, and a welding method using ultrasonic waves cause environmental pollution, the joint portion is not smooth, the strength is not constant, and problems related to watertightness occur frequently.

Therefore, in this specification, a laser welding method that conducts heat locally and implements a non-contact method is proposed and applied.

Laser welding technology

Welding refers to the technology of bonding separated materials by applying heat, pressure, or heat and pressure at the same time. From various electronic parts to large aircraft, oil tankers, power generation facilities, etc., high added value is obtained from materials in the state of primary processing. It is indispensable to the manufacturing, repair, and repair of the product to be created.

In particular, laser welding using the light generated from the laser is a welding method using the heat energy concentrated through the lens. High-strength steel, aluminum alloy, stainless steel, plastic due to the high power, high quality, high efficiency, and high luminance of the laser generator. It is applied to welding various kinds of materials such as.

2 shows an example of a schematic diagram of a laser welding process in connection with the present invention.

Referring to Fig. 2, after fixing the material for laser transmission and the material for absorption (transmitter/absorber) under a clamping force, ① laser is irradiated and the laser beam passes through the laser transmissive body, and ② reaches the absorber. Then, it is absorbed and converted into thermal energy. ③ The converted thermal energy melts the absorber and transfers heat to form a molten pool with the permeable body, and finally joins it.

In addition, FIG. 3 is a diagram illustrating a welding method using a laser in connection with the present invention.

Referring to Fig. 3, the adjustment of the laser output direction and focus becomes an important factor to increase the processing accuracy.

That is, when the laser is output, it is expanded by a beam expander, the direction of the expanded laser is adjusted through a reflecting mirror, and is focused through a focus lens and irradiated onto the workpiece.

In such a welding using a laser, the upper member and the lower member to be welded to each other are closely contacted, and then the edge portion of the adhered member is welded using a laser. In this case, the upper member is a material through which laser light is transmitted, and the lower member May be a material that generates heat by absorbing laser light.

At this time, the laser light passes through the upper member and is heated while being absorbed by the lower member, and the generated heat is transferred to the upper member and is thermally welded to each other to be welded.

As a factor influencing laser welding, in order to control laser welding, consider the transmittance, material compatibility, and thickness in terms of material, and in terms of the welding process, laser output, irradiation rate, clamping pressure and the presence or absence of a dedicated jig, laser Wavelength, beam diameter, product design shape, etc. can be considered.

Regarding the aspect of the welding process, the diameter and wavelength of the laser beam, the power, the irradiation speed, and the number of times have a great influence on the welding quality of the product, so it is necessary to check the laser used, and the above variables according to the size and thickness of the welding part. Is determined.

In addition, the work of optimizing the exterior without deformation and burning due to heat generation of the absorber (DOE: Design Of Energy) is essential, and the clamp used, that is, the pressure of the jig is equally important.

Regarding the technology of laser welding of plastic materials, plastic bonding requires various requirements in order to mass-produce into actual products.

It must be able to be manufactured efficiently in mass industrial production, and in terms of cost, simplification is required than in the existing bolting process, and the types of these bonding technologies include laser welding, rotational welding, vibration welding, and ultrasonic/harmonic welding. In general, laser welding has been suggested as an optimal method to solve the difficulties that occur during plastic welding.

The technology of laser welding of plastic resin uses the property that the energy of the laser beam penetrates the plastic resin of one part and the other part is absorbed by the resin, and the absorbed laser energy is converted into thermal energy and applies an appropriate force to both parts When applied, they are applied as a principle that they are welded to each other.

The main application fields include the welding of plastic resins in automobile lamp housings, external (intra-glass) diagnostic tools, and micro-tube bonding such as microfluidic devices.

Laser welding is an issue in plastic bonding due to its low cost and high efficiency. As a non-contact welding method, there is no external deformation of the product due to vibration, shock, or heat, and there is no burr or fluff, so the quality of bonding is poor. It has the advantage of being excellent.

In addition, laser welding of plastic materials can be applied to 2D and 3D-shaped products, so it is easy to automate, and system stability can be excellent, regardless of size or shape.

Welding device using laser

Hereinafter, a specific configuration of a welding device using a laser proposed by the present invention will be described with reference to the drawings.

4 shows an example of a block diagram of a welding device using a laser proposed by the present invention.

Referring to FIG. 4, the welding device 1 using a laser proposed by the present invention includes a laser emission unit 10, an extension unit 20, a mirror unit 30, a lens unit 40, and a motor unit 50. , A control unit 60, a compression unit 80, a power supply unit 91, a communication unit 92, a user input unit 93, a memory 94, an interface unit 95, and the like.

First, the laser emitter 10 provides a function of emitting a laser.

The laser emitter 10 is exemplarily installed on a horizontal axis to emit a laser, and alternatively, may be installed on a vertical axis.

Next, the expansion unit 20 provides a function of expanding the diameter of the laser output from the laser emission unit 10, and the mirror unit 30 is aligned by adjusting the direction of the laser expanded from the expansion unit 20 Provides the ability to adjust the degree.

The laser emitted in the horizontal direction from the laser emission unit 10 is changed in the vertical direction by the mirror unit 30 to pass through the expansion unit 20.

At this time, the cross-sectional area of the laser irradiated to the workpiece is changed according to the ratio at which the diameter of the laser is expanded by the expansion unit 20.

The extension part 20 may include a lens, a prism, and a collimator that makes the enlarged laser into a parallel beam.

On the other hand, the welding device 1 using a laser can arrange a plurality of mirror units 30 at positions where the direction of the laser emitted from the laser emission unit 10 needs to be changed, and the direction is changed by the mirror unit 30 The resulting laser may eventually become parallel to the laser axis emitted from the first laser emission unit 10.

The mirror unit 30 may be installed to change the direction of the laser so that the laser can be irradiated in a vertical direction to the workpiece.

In addition, the lens unit 40 provides a function of condensing the laser introduced through the laser emission unit 10 to form a focus.

The lens unit 40 forms a focus by condensing the expanded laser again, and may be installed under the mirror unit 30.

The lens unit 00 adjusts the focus by adjusting the position of the lens upward or downward, and for this purpose, a motor unit 50 or the like may be used.

Further, the motor unit 50 is used to change the positions of the mirror unit 30 and the lens unit 40.

In addition, the control unit 60 includes a laser emission unit 10, an extension unit 20, a mirror unit 30, a lens unit 40, a motor unit 50, a crimping unit 80, a power supply unit 91, Controls overall operations of the communication unit 92, the user input unit 93, the memory 94, and the interface unit 95.

The control unit 60 described herein may be implemented in a recording medium that can be read by a computer or a similar device using, for example, software, hardware, or a combination thereof.

According to hardware implementation, the embodiments described herein include Application Specific Integrated Circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), It may be implemented using at least one of processors, controllers, micro-controllers, microprocessors, and electrical units for performing other functions.

According to software implementation, the control unit 60 may be implemented as separate software modules. Each of the software modules may perform one or more functions and operations described herein. The software code can be implemented with a software application written in an appropriate programming language.

In addition, the crimping unit 80 is also called a jig, and is a kind of auxiliary tool used when processing various parts, and refers to a mechanism that forcibly fixes the plurality of objects when welding a plurality of objects. .

The jig 80 refers to a special tool that attaches or attaches a work piece to the work piece to determine the position of the machining part and guides the machining at the same time.In recent years, due to the advancement of the machining method and the rationalization of the production method, many jigs and attachments have been made to be used. It has been made, and an attachment is included in the jig.

In addition, the power supply unit 91 receives external power and internal power under the control of the control unit 60 to supply power necessary for the operation of each component.

In addition, the communication unit 92 may include one or more modules that enable wireless communication between the welding device 1 using a laser and a wireless communication system or between a device and a network in which the device is located.

The communication unit 92 may communicate through short-range communication or wireless communication.

The short-range communication may use at least one of Bluetooth, Radio Frequency Identification (RFID), infrared data association (IrDA), Ultra-Wideband (UWB), and ZigBee technology.

In addition, wireless communication is CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access) technology At least one of them may be used.

In addition, the user input unit 93 generates input data for the user to control the operation of the welding device 1 using a laser.

Here, the user input unit 130 may be composed of a key pad, a dome switch, a touch pad (positive pressure/electrostatic), a jog wheel, a jog switch, and the like.

In addition, the memory 94 may store a program for processing and control of the controller 60, and for temporary storage of input/output data (eg, messages, audio, still images, moving pictures, etc.). It can also perform a function.

The memory unit 94 may also store a frequency of use of each of the data.

The memory 94 is a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, SD or XD memory), and RAM. (Random Access Memory, RAM), SRAM (Static Random Access Memory), ROM (Read-Only Memory, ROM), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read-Only Memory), magnetic memory, magnetic It may include at least one type of storage medium among a disk and an optical disk.

In addition, the interface unit 95 serves as a passage for all external devices connected to the welding device 1 using a laser.

The interface unit 95 receives data from an external device or receives power and transmits it to each component inside the welding device 1 using a laser, or transmits data inside the welding device 1 using a laser to an external device. To be transmitted.

For example, a wired/wireless headset port, an external charger port, a wired/wireless data port, a memory card port, a port to connect a device equipped with an identification module, an audio input/output (I/O) port, A video input/output (I/O) port, an earphone port, and the like may be included in the interface unit 170.

The identification module is a chip that stores various types of information for authenticating the right to use the welding device 1 using a laser, and includes a user identification module (UIM), a subscriber identification module (SIM), and a general-purpose user. It may include an authentication module (Universal Subscriber Identity Module, USIM), and the like.

A device equipped with an identification module (hereinafter referred to as'identification device') may be manufactured in the form of a smart card. Therefore, the identification device can be connected to the welding device 1 using a laser.

When the welding device 1 using a laser is connected to an external cradle, the interface unit 95 becomes a path through which the power from the cradle is supplied to the welding device 1 using the laser, or by a user. Various command signals input from the cradle may be a path through which the mobile device is transmitted. Various command signals or the power input from the cradle may be operated as signals for recognizing that the mobile device is correctly mounted on the cradle.

The laser welding method based on the above-described laser welding device (1) is to weld and bond the permeable cover and the edge of the housing using a laser in a state in which the cover and the housing to be welded are in close contact. A laser is absorbed at the surface of the housing, and the absorbed laser heats and melts the housing at the interface between the cover and the housing, thereby welding and bonding the housing to the cover.

On the other hand, in order to enable laser welding, the upper member and the lower member must be made of the same material. If a member of a dissimilar material is to be welded using a laser, there is a problem in that the welding is not completely performed due to different temperature characteristics according to the material.

That is, as a general laser welding method, it is practically possible to weld a non-transparent housing made of PP, PET, or ABS material to each other as a vehicle lamp made of different materials, that is, a transparent cover made of PC and PMMA materials, and a transparent cover made of PC and PMMA materials, which are fixed to the vehicle body. There was a problem that I didn't.

Further, in the above-described laser welding method, since the laser is absorbed from the surface of the housing after passing through the cover, the surface of the housing sufficiently increases and melts, but the temperature does not rise because the cover is transmitted through the laser.

Therefore, the temperature of the cover is considerably lower than that of the housing, and a large temperature difference occurs, and this temperature difference makes the welding between the housing and the cover not firm and at the same time non-uniform welding quality. Therefore, a phenomenon in which the cover is partially separated from the surface of the housing by the vibration applied while the vehicle is driving has often occurred.

In this case, rain, snow, or external moisture penetrates into the gap between the cover and the housing, causing dew to form in the vehicle lamp, and this dew causes corrosion on the electrodes of the lamp, which shortens the lamp life.

In order to solve the problem caused by such a large temperature difference and to make the welding quality uniform, an annealing process may be applied.

The annealing process is a treatment method in which an alloy hardened by heat treatment is heated at a high temperature for a long time to gradually cool down to room temperature to soften it.In the case of a material in which a phase change occurs as the temperature rises or falls, it is gradually cooled over a sufficient period of time to obtain a stable equilibrium state. Say.

However, when such an annealing process is applied, there is a big problem that a short-circuit process part occurs in the entire welding process, and the manufacturing cost is remarkably increased.

Therefore, in the present specification, by melting the upper transparent material while melting the lower material together and welding, based on the laser beam, it is intended to propose a technology that enables high-quality welding without an annealing process.

How to use a double laser beam

In order to solve the above-described problem, in the present specification, as a first embodiment, a method of using a laser beam of a wavelength band for preheating the transmissive cover and a laser beam of another wavelength band to melt the welding boundary between the transmissive cover and the non-transmissive housing. Suggest.

5 illustrates an example of using a laser beam in a wavelength band for preheating a transparent cover and a laser beam in another wavelength band for melting a welding boundary between the transparent cover and the non-transmissive housing in connection with the present invention.

Referring to FIG. 5, the laser welding method according to the present embodiment begins with a step of intimate contact between a transmissive cover 200 of a vehicle lamp made of a different material and a non-transmissive housing 100 coupled to the transmissive cover 200. .

Thereafter, the second laser beam 12 of a second wavelength for preheating the transmission preheating region 210 of the transparent cover 200 and the transmission preheating region 210 are overlapped with the transmissive cover 200 and the non-transmissive housing. In order to weld the welding boundary surface 70 therebetween, the first laser beam 11 having a first wavelength shorter than the second wavelength is irradiated to the welding boundary surface 70.

At this time, the temperature of the first laser beam 11 irradiated to the welding boundary surface 70 is detected and a corresponding temperature signal is generated, and the temperature signal is transmitted to the control unit 60 in real time. It is used to control the output.

Here, the transmissive cover 200 transmits light irradiated from a light source and is mainly made of PC (Poly Carbonate) or PMMA (Poly Methyl Methacrylate) material.

In addition, the non-permeable housing 100 is generally made of polypropylene (PP), polyethylene terephthalate (PET), or acrylonitrile butadiene styrene copolymer (ABS).

In addition, the second laser beam 12 is for preheating the transmitted transmission preheating area 210, and for this purpose, the first wavelength of the second laser beam 12 is in the range of 1600 to 2000 nm, preferably in the range of 1670 to 1960 nm. Can be.

The second laser beam 12 of the second wavelength is absorbed by about 50 to 70% while passing through the transparent PC made of thermoplastic resin or the transparent cover 200 made of PMMA material to preheat the transmission preheating area 210 Have.

In addition, the first laser beam 11 is for melting the welding boundary surface 70 after passing through the transmissive cover 200, and the welding boundary surface 70 overlaps the preheated transmission preheating area 210.

To this end, the second wavelength of the first laser beam 11 is in the range of 750 to 1000 nm, preferably in the range of 808 to 980 nm.

The first laser beam 11 of this first wavelength is not absorbed by the transmissive cover 200 made of PC or PMMA, but is almost transmitted, and is mostly absorbed by the welding boundary surface 70 of the non-transmissive housing 100. And, accordingly, the welding boundary surface 70 is melted.

That is, the second laser beam 12 preheats the transmission preheating area 210 overlapping the welding boundary surface 70, so that when the first laser beam 11 melts the welding boundary surface 13, the first The difference in temperature characteristics between the permeable cover 200 and the non-permeable housing 100 is minimized.

Further, the output of the first laser beam 11 is 20 to 40 W, preferably 30 W, and the second laser beam 12 has an output of 20 to 50 W, preferably 40 W.

Here, the output of the second laser beam 12 may be greater than the output of the first laser beam 11, because the second laser beam 12 has to preheat a larger area than the first laser beam 11 to be.

In addition, the first laser beam 11 and the second laser beam 12 may be irradiated to overlap each other.

How to use a single laser beam in the infrared wavelength band

In addition, in order to solve the above-described problem, in the present specification, as a second embodiment, by irradiating a laser beam having an infrared wavelength band through the edge of the transmissive cover toward the contact area of the contact housing, preheating the transmissive area of the transmissive cover. And propose a method of melting the contact area.

6 shows an example of preheating the transmission area of the transparent cover and melting the contact area by irradiating a laser beam having an infrared wavelength band through the edge of the transmissive cover toward the contact area side of the attached housing according to the present invention. I did it.

6, in the welding method using a laser according to the present invention, the transparent cover 200 is in close contact with the housing 100, partially absorbed in the transmission region 220 passing through the transparent cover 200, and Welding is performed in the contact area 70 by irradiating a laser beam having a wavelength range of 1400 to 3000 nm so that the rest of the contact area 70 between the cover 200 and the housing 100 can be absorbed.

Here, the housing 100 may be fixed to a vehicle body, etc., a lamp may be embedded therein, and a mirror coating for reflecting light may be formed.

The housing 100 is a thermoplastic resin made of an opaque material, such as PP (PolyPropylene), PET (Polyethylene Tere70thalate), A13S (Acrylonitrile 13utadiene Styrene copolymer), PMMA (Poly Methyl Methacrylate),

It may be any one material selected from the group consisting of COC (Cyclic Olefin Copolymer).

Meanwhile, the permeable cover 200 may be welded to the inlet of the housing 100 to block external water or moisture from flowing into the interior of the housing 100.

This transparent cover 200 is a thermoplastic resin of a transparent material so that light irradiated from the lamp of the housing 100 is transmitted without loss, and may be any one material selected from the group consisting of PC (PolyCar13onate), PMMA, and COC. have.

Regarding the step of bringing the permeable cover 200 into close contact with the housing 100, the permeable cover 200 is formed by a jig 80 so that the edge of the permeable cover 200 can be completely in close contact with the housing 100. It can be pressed toward the (100) side.

In connection with the step of performing welding by irradiating the laser beam 13 through the transmissive cover 200 to the contact area 70 where the housing 100 and the transmissive cover 200 are in close contact with each other, irradiation with the transmissive cover 200 The laser beam 13 is partially absorbed in the transmissive region 220 of the transmissive cover 200, and the surface of the housing 100 to which the transmissive cover 200 is in close contact, that is, the transmissive cover 200 and the housing 100 By allowing the remainder to be absorbed in the contact area 70 between the ), the contact area between the housing 100 and the permeable cover 200 is welded together.

To this end, the laser beam 13 has a wavelength range of 1400 to 3000 nm, more preferably 1670 nm or 1940 nm.

The relationship between the transmittance (T) and the wavelength (λ) of the laser beam 13 to the thermoplastic resin decreases as the wavelength increases.

In this case, the low transmittance means that the absorbance for absorbing the laser beam 13 is increased, and accordingly, the temperature of the transmission region 220 through which the laser beam is transmitted increases.

Here, when the wavelength of the laser beam 13 is 1670 nm or 1940 nm, the absorbance of the transmissive region 220 increases exponentially as the surface side of the transmissive cover 12 approaches the contact region 70. .

Accordingly, the temperature generated in the light-transmitting area close to the contact area 70 and the temperature generated in the contact area 70 have a relatively continuous relationship, so that the materials of the housing 100 and the transmissive cover 200 are different. Even if it is a material, the quality of the welding bond between the permeable cover 200 and the housing 100 by melting in the contact region 70 is maximized.

In addition, since the temperature gradually increases by absorbing the laser beam from the transmissive area on the surface side of the transmissive cover 200, the temperature on the surface side of the transmissive cover 200 and the temperature of the outside environment outside the transmissive cover 200 are also relatively continuous. To achieve.

Therefore, it is possible to prevent the surface of the permeable cover 200 from being deformed due to the temperature difference between the surface of the permeable cover 200 and the outside air environment during the welding process. Accordingly, even if the permeable cover 200 is a temperature-sensitive material, high-quality welding is possible. It is possible.

In this way, the laser beam 13 is partially absorbed in the process of passing through the transmissive cover 200 to preheat the transmissive region 70, and then the rest is absorbed in the contact region 70 to melt the contact region 70. Let it.

At this time, since the transmissive region 70 is preheated by absorbing the laser beam, the temperature increases, and accordingly, the temperature difference between the transmissive region 220 and the contact region 70 decreases, and thus the melting of the housing 100 The surface is firmly bonded to the permeable cover 200 to improve the quality of welding.

In the present invention, typically, a laser using thulium can be applied.

As described above, a laser having an infrared wavelength band of 1400 to 3000 nm, more preferably 1670 nm or 1940 nm is used.

Only in the case of using a laser in this range, the laser beam 13 is partially absorbed in the process of passing through the transmissive cover 200 to preheat the transmissive region 70, and then the rest is absorbed in the contact region 70 and the contact region (70) can be melted.

According to the method proposed in the present specification, since the transmission region 70 is preheated by absorbing the laser beam, the temperature rises, and accordingly, the temperature difference between the transmission region 220 and the adhesion region 70 becomes small, and thus Since the surface of the housing 100 to be melted is firmly welded to the permeable cover 200 to improve the quality of welding, in the end, the conventional annealing process can be omitted.

As described above, in the present invention, by omitting the application of the annealing process, the short-circuiting process part in the entire welding process is eliminated, and the manufacturing cost can be significantly reduced.

Laser welding conditions

In addition, by irradiating a laser beam having an infrared wavelength band proposed as a second embodiment through the edge of the transmissive cover toward the contact area of the adhering housing, the method of preheating the transmissive area of the transmissive cover and melting the contact area is described in an automobile lamp. Preferred conditions when applied to will be described.

The output of the laser beam is preferably 20 to 50 W, preferably 40 W.

If the output of the laser beam is less than 20W, the output is significantly weakened while the laser beam passes through the transmission region 220 of the transmissive cover 200, so that the adhesion region 70 cannot be melted, and thus fusion is difficult. .

And when the output of the laser beam 13 is 50W or more, the transmissive region 220 of the transmissive cover 200 melts and becomes opaque. In this case, combustion occurs in the transmissive region 220 while absorbing more laser beams. Or the fusion reliability is deteriorated.

7 is a table showing the preferred condition values for laser welding to a vehicle lamp in relation to the present invention.

Referring to FIG. 7 as the most preferable condition, the laser focal size is Φ 2.2㎜, laser intensity 25W, welding speed At 29.5 mm/sec, the best effect could be achieved.

Furthermore, the pressure weight through the jig 80 is 25 ± 5 ㎏f, and the thickness of the laser beam is 7 mm, and the perimeter of the transmitted laser is 619.8 mm, and the radius is When it was 32.9 mm, the best welding effect could be obtained.

Welding using reflective surface structure

In addition, in order to solve the above-described problem, as a third embodiment, the present specification proposes a method of performing welding of a desired area by placing a reflective surface therein.

8 shows an example of performing welding of a desired area by placing a reflective surface therein in connection with the present invention.

Referring to FIG. 8, the first member 200 is a transparent resin member made of a thermoplastic resin (hereinafter, optically transparent part), and the second member 100 is an opaque resin member made of a thermoplastic resin (hereinafter, optically opaque). One part).

Reference numeral 340a denotes a joint at the rib wall (side), 340b denotes a joint at the bottom of the rib, and 13 denotes light energy introduced by the light energy generating device 10.

Regarding the arrangement of the optical axis reflection surface, a reflection surface 350 of light energy is provided at the tip of the rib of the optically transparent component 200.

This reflective surface is designed to reflect light energy as an inclined surface to the rib tip of the optically transparent component 200.

The reflective surface 350 may select light energy suitable for the absorption wavelength range of the optically opaque component 100 and reflect the light energy,

Further, the calibration rib 330 will be described. The fitting position correction rib 330 is disposed on the side of the optically opaque component 100 for the purpose of reliably bonding and welding the joint portion 330a on the rib wall surface.

As shown in FIG. 8, for the junction portion 340b on the bottom of the rib, a junction portion 340b on the bottom surface so that some light energy is transmitted to the bottom of the rib is provided.

In the setting of the optical axis reflective surface, the welding (welding) property is advantageous if the joint portion 340a of the rib wall surface of welding (welding) is the rib wall surface so as to be less as described above. Accordingly, the bonding surface becomes the bonding portion 340a serving as a wall surface.

In addition, light energy 13 is irradiated from the upper side of the optically transparent component 200.

However, since the light energy 13 in the normal shape passes through the rib and falls to the lower side due to wall reflection or the like, a reflective surface 350 of the light energy 13 is installed at the tip of the rib, and the optical axis is bent to prevent the housing wall surface. By irradiating the light energy 13 to the junction (340a) of the rib wall can be welded (welding, 320).

Through the reflective surface 350, most of the light energy 13 irradiated from the optically transparent component 200 reaches the junction 340a 3 provided on the wall surface of the rib of the optically opaque component 100.

In addition, since the joint 340b_ on the bottom surface of the rib is provided, the cross-section of the joint is of an L-shaped structure, so the strength of the welding (welding) site is more than that of the conventional joint specification (a straight line such as a letter or I). Can be expected to increase.

Therefore, according to the proposed method, it is possible to provide a component shape with higher welding (welding) strength than conventional products while stably maintaining a high-quality welding (welding) state while reducing design restrictions.

Here, the reflective surface is provided on the inclined surface shown in the cross-sectional view as the rib tip of the transparent resin member, and the bottom surface does not have a reflective surface.

In addition, when fabricating a reflective surface, any means can be used as long as it can reflect light energy in a certain wavelength range.

For example, it is possible to coat an optically reflective material as a method for fabricating a reflective surface, and if it is an optically reflective film, it is also possible to coat by other means such as coating, vapor deposition, or plating.

How to weld a curved object

In addition, in order to solve the above-described problem, as a fourth embodiment, the present specification proposes a method of adjusting the focal length, output value, etc. using height information from a reference point of a curved object based on one laser source. do.

9 illustrates an example of adjusting a focal length, an output value, and the like using height information from a reference point of a curved object based on one laser source in relation to the present invention.

As shown in FIG. 9, in the case of welding an object having a curvature, in the present embodiment, a method of using a plurality of laser sources or rotating a single laser source or an object receiving a laser is not used.

Instead, in this embodiment, one laser source is used, information on a curved object is obtained in advance, and the focal length, output value, speed, etc. of the laser source are adjusted using the change in height information from the reference point of the curved object. Suggest a way to do it.

Referring to FIG. 9, information on a curved object made of the transparent member 100 and the opaque member 200, for example, information on length, height change, shape, etc. may be obtained in advance.

Thereafter, while changing the focal length, output value, speed, separation distance from the object, etc. of the laser emitter 10 under the control of the control unit 60, a plurality of laser sources are used, or a single laser source or a laser is received. Welding can be performed on a curved object without rotating the object.

How to improve adhesion between objects and prevent internal damage by laser

In addition, in order to solve the above-described problem, in the present specification, as a fifth embodiment, a welding surface is formed so that the lower surface of the transparent plastic in contact with the opaque plastic has an angle perpendicular to the jig, and an intermediate surface is formed between the welding surface and the transmitting part. And forming an angle exceeding a critical angle with respect to the laser, and thus a method of preventing laser inflow into the interior is proposed.

10A and 10B illustrate an example of forming a welding surface such that a lower surface of a transparent plastic contacting an opaque plastic has an angle perpendicular to the jig.

In FIGS. 10A, 10B, and 11, it is assumed that welding is performed to make a vehicle luminaire.

Referring to FIGS. 10A and 10B, in the vehicle luminaire 1, the front opening of the container-shaped housing 100 with the front opening is covered by a transparent cover 200, and the housing 100 and the transparent cover 200 are covered. The light source 10 is arranged in the lamp room partitioned by this.

A welding surface 70 is formed on the rear surface of the periphery of the transparent cover 200 over the entire circumference, and the welding surface 70 is formed on the periphery of the front opening of the housing 100 by welding the welding surface 21 and light rays. Are joined.

That is, the housing in close contact with the welding surface 70 by transmitting the welding rays, which are coherent or non-interfering electromagnetic waves such as laser, visible rays, ultraviolet rays, infrared rays, etc., from the front side of the transparent cover 200 through the transparent cover 200 The welding surface 21 of (100) is irradiated.

That is, the portion 32i of the front surface 32 of the transparent cover corresponding to the welding surface 70 becomes the light incident surface.

By irradiation of the welding light, the welding surface 21 is excited by irradiation of the welding light, which is the electromagnetic wave, and generates heat, and is in close contact with the welding surface 21 and the welding surface 21 by the heat. The welding surface 70 of the transparent cover 200 melts together to become a commercial state, and the material resin of the housing 100 and the transparent cover 200 is integrated at the interface where the two welding surfaces 21 and 31 are in contact. .

Then, after the irradiation of the welded light, which is the electromagnetic wave, is terminated, the commercially available portion is cooled and solidified, whereby the transparent cover 200 is integrally bonded to the housing 100.

As described above, the transparent cover 200 needs to transmit a welding light, for example, a laser, and therefore, the material of the transparent cover 200 requires that the material of the transparent cover 200 has poor absorption of the welding light, which is an electromagnetic wave to be irradiated. For example, a transparent synthetic resin such as PMMA (polymethyl methacrylate) is preferable.

In addition, since the housing 100 is excited by the irradiation of an electromagnetic wave, which is an electromagnetic wave, and generates heat, the material is applied to radicals whose wavelength and vibration period coincide with the irradiated electromagnetic wave. It needs to have a molecular structure composed of.

As shown in FIG. 10, the transparent cover 200 has a flat shape with an almost constant thickness, and the front surface 32 is largely curved, and both ends in one cross-section, for example, the upper and lower ends of FIG. 2 ( 32u and 32d are inclined in opposite directions (θu, θd) with respect to the reference line (the line of the optical axis of the light source 10) XX.

Referring to FIG. 11, an enlarged cross-sectional view of a portion enclosed by a circle III of FIG. 10, that is, an upper end portion is shown.

In the case of performing ray welding, as described above, if the two welding surfaces 21 and 31 are not in close contact, the heat generated on the welding surface 21 of the housing 100 is transferred to the welding surface 70 of the transparent cover 200. ) Is not transmitted effectively, and a poor adhesion occurs in a place where the adhesion state is damaged.

In addition, in this specification, the term ``closed state'' means that the two faces are in close contact, as long as the gap is 0.1 mm (millimeter) or less, even if there is a gap between the two faces. The state in which the gap of 0.1 mm or less is interposed between them and the state in which the two surfaces are in close contact are collectively referred to as a "close state".

And, in order to bring the two welding surfaces 21 and 31 into a close contact state, a pressing force is applied from the front side of the transparent cover, so that the welding surface 70 of the transparent cover 200 is attached to the welding surface 21 of the housing 100. Squeezed into.

In this case, it is necessary to apply a pressing force in the direction of arrow 10 in FIG. 11 in order to uniformly apply the pressing force over the entire circumference of the welding surface 70.

The pressing direction F is a direction in which the angle θf formed with a line perpendicular to the front surfaces (eg, 32u, 32d) of both ends in one cross-section becomes substantially the same.

If the inclination angle of the welding surface 70 is the same as the inclination angle of the front surface 32, the welding surface 70 having the same inclination angle as the front surface 32 by the pressing force F applied in the direction of arrow 10, The surface pressure (Fs) acting in the vertical direction is equal to Equation 1 below.

Equation 1

That is, as θf increases, the surface pressure Fs decreases. And, as the surface pressure Fs decreases, the degree of adhesion between the two welding surfaces 21 and 31 decreases.

Therefore, in the vehicle luminaire 1 of the present invention, the angle formed between the front surface 32 and the front surface 32 by increasing the thickness of the portion of the rear surface of the transparent cover 200 that becomes the welding surface 70 is inside, that is, the luminaire (1) The angle (θ31) formed by the line perpendicular to the welding surface (70) and the pressing direction (10) by forming an inclination different from the front surface (32) so as to increase toward the center of (1) is the angle (θf) Make it smaller.

In this case, the surface pressure F31 acting in the direction perpendicular to the welding surface 31 of the inclination angle θ31 by the pressing force F applied in the direction of the arrow 10 is equal to Equation 2 below, and, Since θf>θ31, it becomes F31>Fs.

Equation 2

In other words, compared to the case where the inclination angle of the welding surface 70 is the same as the inclination angle of the front surface 32, a greater pressing force is applied between the two welding surfaces 21 and 31, and the two welding surfaces 21 , 31) The space is firmly in close contact.

Meanwhile, FIG. 11 shows an example of preventing laser inflow into the interior by forming an intermediate surface between the welding surface and the transmissive portion and forming an angle exceeding a critical angle with respect to the laser in relation to the present invention.

In Fig. 11, the light incident surface (b) and the welding surface (c) have the same inclination angle, and therefore, a transparent cover (a) having no thickened portion and no intermediate surface is placed on the housing (d). An example of the case of welding is shown.

The welding surface (c) of the transparent cover (a) is closely overlapped with the welding surface (e) formed on the periphery of the opening of the housing (d), and the laser (f) is transmitted through the transparent cover from the light incident surface (b). Irradiate the welding surfaces (e, c).

At this time, if the laser f is accurately irradiated to the welding surfaces e and c, there is no problem, but there is a case where the irradiation position of the laser f is shifted inward. Then, a part (g) of the laser (f) is further irradiated to the inside of the luminaire away from the welding surface (e) of the housing (d), and there is another member disposed in the luminaire, such as an extension (h). If there is a light, a part (g) of the laser (f) is irradiated to the member (h), but there is a fear that the irradiated part (i) may be burned.

So, if the intermediate surface 34 is formed between the welding surface 31 of the transparent cover 3 and the illumination light transmitting portion 33, as shown in FIG. 11, as in the vehicle lighting 1 of the present invention, as shown in FIG. When the laser L is shifted inward and a part Lp of the laser L is shifted inward from the welding surfaces 21 and 31, a part Lp of this laser is incident on the intermediate surface 34.

And, since this intermediate surface 34 has an inclination that exceeds the critical angle with respect to the welded light beam, a part Lp of this laser is totally reflected by the intermediate surface 34 and is directed outward.

Therefore, even if there is a member such as an extension behind the intermediate surface 34, there is no fear that this member is damaged by a welding beam such as a laser off the target.

How to use a transparent jig

In addition, in order to solve the above-described problem, in the present specification, as a sixth embodiment, a method of increasing the degree of adhesion by applying a pressing jig transparently and allowing the laser to reach through the jig is proposed.

12 shows an example of increasing the degree of adhesion by applying a pressing jig transparently and allowing the laser to reach through the jig in connection with the present invention.

Referring to FIG. 12, in the method of welding a light beam according to the present embodiment, the first resin member 200 in which the welding portion 70 is provided has transmittance with respect to irradiation light and transmittance to the first resin member with respect to the irradiation light. This is a light-beam welding method in which the second resin member 100 having a smaller transmittance and provided with a welded portion is welded by the irradiation light.

In particular, in this embodiment, the welding portion 70 of the first resin member 200 is pressed against the welding portion 70 of the second resin member 100 using a pressing jig 80 formed of a transparent material. The first resin member is formed of a transparent material while pressing the welded portion 70 of the first resin member 200 against the welded portion 70 of the second resin member 100 by a pressing process and a pressing jig 80 A heating process in which at least one of the welded portion of the first resin member or the welded portion of the second resin member is softened by heating with a heating element provided in the pressing jig 8 so as to contact the welded portions in close contact with each other. And a light source presses the irradiation light through the jig 80 and the first resin member 200 to irradiate the welded portion 70 of the second resin member 100 so that the first resin member 200 and the second A welding process of welding the resin member 100 is provided.

Therefore, it is not necessary to move the heating element for heating the welded portion in the direction in contact with the second resin member 100 before the pressing operation by the pressing jig, and the pressing jig 80 is formed of a transparent material so as to contact the first resin member 200. ).

Through the transparent jig 80, the heating operation and the pressing operation can be performed continuously, and workability is improved, and then good bonding properties are secured by welding the first resin member 200 and the second resin member 100. can do.

How to stay in close contact without a jig

In addition, in order to solve the above-described problem, in the present specification, as a seventh embodiment, a method of maintaining a close contact without a separate jig by inserting defects in the seating portion formed on the resin cover to which the welder protruding from the housing is welded is described. Suggest.

13 shows an example in which the welder protruding from the housing is inserted into a defect formed in the resin cover to be welded, thereby maintaining a close contact without a separate jig.

Referring to FIG. 13, it is a schematic cross-sectional view illustrating an enlarged connection state of the housing 100 and the outer cover 200.

The welding base 101 is fitted into the groove so that the outer peripheral side side of the welding base 101 and the inner wall of the first welding leg are joined by laser welding.

The laser welding portion 70 is located in a direction parallel to the fixing direction z'.

Even when the vehicle luminaire 1 is viewed from the front direction of the laser welding portion 70, the laser welding surface is hardly observed because the laser welding surface is parallel to the viewing direction.

Therefore, even when a non-uniform welding portion has occurred on the laser welding surface, the appearance can be not impaired.

Next, a method of bonding the outer cover 200 to the housing 100 by laser welding will be described.

The outer cover 200 is assembled by covering the concave portion in a direction parallel to the welding base 101 formed on the front circumference of the housing 100, that is, in the z'direction.

At this time, the welding base 101 is fitted so as to be inserted into the groove 201.

The outer peripheral side of the welding base 101 and the inner wall of the first welding leg are formed to be parallel to each other, and the inner side of the welding base 101 and the inner wall of the second welding leg are parallel to each other, and have the same size as the groove 201. Can be formed.

In addition, the welding base 101 may have a narrow cross-sectional trapezoidal shape in the width side of the tip side.

Therefore, when the welding base 101 and the welding leg are fitted together, the welding base 101 is in surface contact and fixed in the groove 201.

In addition, it is desirable to mold the housing 100 and the outer cover 200 to always make surface contact over all sides, but when it is difficult due to errors in injection molding and mold manufacturing reasons, the laser welding portion 70 of the groove 201 becomes It is desirable to have the side contact the surface.

Further, it is preferable that the welding base 101 has a shape having a side surface that is only inclined with respect to the fixing direction z'.

This is because by inclining, the surface contact at the laser welding portion can be strengthened by using its own weight.

In addition, it is preferable that either of the side surface of the weld base 101 and the inner wall of the groove 201 be a smooth surface.

This is because the laser welding surface can be a clean bonding by setting it as a smooth surface.

Subsequently, laser welding is performed while the housing 100 and the outer cover 200 are fitted together.

The laser light L (10) may be irradiated from the left side of the ground, that is, from the outer peripheral side of the vehicle luminaire (1).

The laser light L (10) passes through the first welding leg and is directed toward the welding base 101, and the welding base 101 receiving the laser light L (10) generates heat, and also heats the first welding leg by thermal conduction.

Thereafter, both are in a molten state, fused and welded. When the laser light L 10 is not irradiated, it is cooled and the laser welded portion 70 is bonded and fixed at the laser welded surface.

In this embodiment, when irradiating the laser beam L10, a special jig 80 is not used to apply pressure from the outside.

In the conventional laser welding, it was necessary to pressurize the bonding surface using the jig 80, but in this embodiment, the welding base 101 is inserted into the welding leg or groove 201, so the housing 100 ), or even if a special jig 80 is not used due to the weight of the outer cover 200, the laser welding portion 70 has a surface-contact bonding surface.

Therefore, it is possible to solve the conventional problem that the central portion of the outer cover 200 is damaged or contaminated.

Additional Examples

According to another embodiment of the present invention, in order to prevent the laser from entering and burning into the interior, an intermediate surface is formed between the welding surface and the illumination light transmitting part, and formed to be at an angle exceeding the critical angle with respect to the light beam, thereby forming a layer into the interior. It is possible to prevent inflow.

Further, according to another embodiment of the present invention, it is possible to increase the welding efficiency by increasing the scanning speed of the laser in a region where the incident angle is relatively small and the incident energy density is increased.

Laser welding market

14A to 14D are graphs for explaining the laser welding market related to the present invention.

14A shows the global laser welding market size in millions of dollars.

Referring to FIG. 14A, in the global market, the laser welding market is expected to grow from $ 1.425 billion in 2016 to 5.79% on an annual average, and grow to $ 1.97 billion by 2022.

In addition, FIG. 14B shows the market size of each laser welding region in units of million dollars.

Referring to FIG. 14B, the Asia-Pacific market is expected to account for the largest share, and is expected to grow from USD 528 million in 2016 to USD 765 million in 2022.

In addition, FIG. 14C shows the market size of each laser welding application industry in units of million dollars.

Referring to Fig. 14c, the machine tool market is expected to occupy the largest proportion, and is expected to grow from $366 million in 2016 to $483 million in 2022.

In addition, FIG. 14D shows the global laser plastic welding market size in billions of dollars.

Referring to Figure 14d, it is expected to grow from $758.9 million in 2016 to an annual average of 8.3% to reach $1.543.2 million in 2025, and the Asia-Pacific region is expected to reach $342.8 million (42% share). As it occupies the market, it occupies the largest market share in the world.

The global laser plastic welding market is pursuing innovation in various methods such as welding method, laser source, and automation to enter the highly competitive manufacturing machinery market.

With the advancement of laser plastic welding technology, it is possible to produce high-quality weld joints, and the laser plastic welding market is growing rapidly.In particular, as consumers' preference for aesthetic products increases, welding on the hidden surface There is an increasing demand for laser welding that can do the job.

The rapid decline in the price of laser welding equipment is also affecting the market expansion.

Therefore, it is judged that the demand for the welding device and control method using a laser proposed by the present invention is high and high marketability is guaranteed.

Effects according to the invention

The present invention has been devised to solve the conventional problems as described above, and a welding device using a laser and a control method thereof can be provided to a user.

Specifically, the present invention can provide a user with an apparatus and method for welding opaque plastics and transmissive plastics without annealing process using a laser beam having a wavelength of 1400 to 3000 nm.

According to the present invention, by omitting the application of the annealing process, there is an effect that the short circuit process part in the entire welding process can be eliminated, and the manufacturing cost can be remarkably reduced.

The laser welding according to the present invention enables plastic bonding with low cost and high efficiency, and as a non-contact welding method, there is no external deformation of the product due to vibration, shock, and heat, and the bonding quality is excellent because no burr or fluff occurs. As it can be applied to products of 2D, 3D shape, regardless of size or shape, automation is easy, and system stability can be provided.

In addition, since the laser is used, it is possible to increase the flexibility of the welding operation by increasing the focal length, and since the shape and the focal size of the laser beam can be changed, welding to an object having a three-dimensional shape is possible.

In addition, according to the present invention, the temperature difference between the transmissive region and the close contact region is reduced, so that the housing and the transmissive cover are firmly welded together, and further, a constant weld quality can be expected.

In addition, since preheating of the transmissive region and melting of the contact region proceed at the same time, even if the permeable cover and the non-permeable housing are of heterogeneous materials, there is an action and effect that solid and fast welding and bonding are possible.

On the other hand, the apparatus and method described above are not limitedly applicable to the configuration and method of the above-described embodiments, but the embodiments are all or part of each of the embodiments selectively combined so that various modifications can be made. It can also be configured.

Claims (1)

In the plastic welding device for welding the first impermeable plastic and the second transmissive plastic without annealing using a laser beam,

The plastic welding device,
The first plastic and the permeable second plastic are brought into close contact,
Irradiating a laser beam to the first and second plastics that are in close contact with each other,
At least a portion of the laser beam is first absorbed while passing through the second plastic, and the remaining beam is second absorbed in the first contact area of the first plastic and the second plastic,
Using the first absorption and the second absorption to allow the first adhesion region to be welded,

The laser beam has a wavelength range of 1400 to 3000 nm,

At least a portion of the laser beam transmitted through the second plastic is reflected on a reflective surface provided in at least a portion of the second plastic,
The reflected laser beam is absorbed into a second contact area of the first plastic and the second plastic different from the first contact area,
The first contact area and the second contact area are welded together,

When there is a part in which at least a part of the first plastic and the second plastic is curved,
The plastic welding device,
Before the first plastic and the second plastic are brought into close contact, first information on the curved part is collected,
The laser beam adjusts at least one of a focal length, an output value, a speed of the irradiated laser beam, and a separation distance between the first plastic and the second plastic according to the first information,
The first information includes length, height change, and shape information for the curved part,

In at least a portion of the first plastic and the second plastic, an intermediate surface formed with a step having an angle exceeding a critical angle through which the laser beam is introduced is formed, so that the laser beam is transmitted to an area other than the first contact area Is prevented from entering,

The plastic welding device,
Before irradiating the laser beam to the first and second plastics that are adhered, the first and second plastics are further brought into close contact with each other using a jig,

The jig is transparent,

The plastic welding apparatus, characterized in that the output of the laser beam is increased in a region in which the incident angle of the laser beam is equal to or less than a preset value or the incident energy density is increased among the first contact regions.

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