JP2003127178A - Method and apparatus for changing material and color in injection molding machine, and apparatus for changing material and color in its mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform material change and color change in a short time. SOLUTION: The apex 19A of a screw 19 is arranged more forward than a feeding opening 20A of a hopper 20 and is rotated, and a molten molding material in a heating cylinder 17 is discharged through a gate to a product cavity provided in a fixed mold 5 from a sprue. Opening and closing operation of a valve pin 66 is performed during material changing and color changing. By continuously passing a molding material under a molten condition through the sprue and the gate, an old molding material existing in the heating cylinder 17, the sprue, a runner and the gate is rapidly discharged. It is possible thereby to perform the material change and the color change in replacing the old molding material with a new molding material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material change or color change method in an injection molding machine for changing the material or color of a molding material (hereinafter referred to as material change or color change), a device therefor, and a material for a die thereof. And a color changing device.

[0002]

As an in-line screw type injection molding machine of this kind, one having various structures is conventionally known. In such an injection molding machine, the molding material is changed. Often molded,
Further, it is often practiced to change the color and mold even the same type of molding material with the same mold. Then, conventionally, the following method has been generally used to change the material and color of the molding material in this kind of injection molding machine. That is, the molding material injected from the nozzle on the tip side in the cylinder of the injection molding machine is designed to inject the molding material melted into the cavity from the molding material passage. To change colors, stop feeding the original molding material (old molding material) into the hopper, which is the material supply unit on the base end side of the cylinder, and then add the new molding material (new molding material). Input,
Start supply. Then, by repeating the measurement and injection several times, the old molding material is gradually extruded and removed from the nozzle portion, and the old molding material is replaced with the new molding material.

However, in the material change and color change in the conventional injection molding, the old molding material is gradually extruded by the new molding material and eliminated by repeating the measurement of the cylinder and the injection operation. Therefore, there is a problem that a molding product in which old and new molding materials are mixed is obtained at the time of this replacement operation, and not only the molding material is wasted, but also such a replacement operation time is long. Furthermore, it has been difficult to completely eliminate the old molding material that remains and adheres to the mold and nozzle portions by the conventional material changing and color changing methods.

Therefore, the present invention is to change the material of the injection molding machine,
Color change can be performed efficiently and in a short time, and in the case of a gate type valve, even a material adhered to a valve can be reliably removed. The purpose is to provide a material changing device and a color changing device.

[0005]

According to a first aspect of the present invention, a mold clamping device is provided on one side of the base and an injection device is provided on the other side of the base. The screw is built into the heating cylinder with the material supply section on the base end side, and the pressurizing device is connected to this screw, and the mold clamping device and the injection device are fixed to the movable mold that forms the product cavity. In the method of material change and color change in an injection molding machine in which the nozzles are connected to the material passages of the fixed mold while the molds are respectively attached, the tip of the screw is placed in front of the raw material supply unit and rotated, and the heating is performed. In an injection molding machine, the molten molding material in the cylinder is discharged from the material passage through a gate to a product cavity provided in the fixed mold. That material replacement, a color change method.

According to the structure of the first aspect, the molding material melted from the heating cylinder is discharged from the gate through the material passage so that the material and the color can be changed.

According to a second aspect of the present invention, the gate provided on the fixed mold is opened and closed by a valve, and the valve is opened and closed during material change and color change.
It is a method of material change and color change in the described injection molding machine.

According to the second aspect of the present invention, the material of the valve is changed, and the valve is opened / closed during the color change to promptly discharge the old molding material adhering to the material passage or the valve.

According to a third aspect of the present invention, a mold clamping device is provided on one side of the base and an injection device is provided on the other side of the base.
The injection device has a screw built in a heating cylinder having a nozzle formed at the tip and a raw material supply unit provided at the base end, and a pressurizing device is connected to this screw, and a product cavity is connected to the mold clamping device and the injection device. In the injection molding machine in which the movable mold and the fixed mold that form the above are respectively attached, and the nozzle is connected to the material passage of the fixed mold, the position detecting means of the screw is provided and the position detecting means is connected to the control device. An injection molding machine is characterized in that a pressurizing device is connected to the control device, and the pressurizing device is operated at the time of material change and color change by the control device based on the position detection means.

According to the structure of claim 3, the heating cylinder is arranged at a predetermined position by the screw position detecting means, and the molding material melted from the inside of the heating cylinder is discharged from the gate through the material passage to change the material. You can change colors. According to a fourth aspect of the present invention, the gate provided on the fixed mold is opened and closed by a valve, and the valve driving means for reciprocating the valve a plurality of times during material change and color change is provided. It is the described injection molding machine.

According to the structure of claim 4, the material of the valve is changed, and the valve is opened / closed during the color change to promptly discharge the old molding material adhering to the material passage or the valve.

The invention of claim 5 is the injection molding machine according to claim 4, characterized in that the control device is provided with a timer for material change and color change time setting.

According to the fifth aspect of the invention, the time for material change and color change can be adjusted by the timer.

According to a sixth aspect of the present invention, the molding material in the material passage is always kept in a molten state, and the material used for switching the molding material is a mold for opening and closing the gate from the material passage to the product cavity by a valve. A color changing device,
A material changer and color changer for a die, comprising a valve drive means for reciprocating the valve a plurality of times and an operation part connected to the valve drive means.

According to the sixth aspect of the present invention, the operating portion is operated to change the material by the valve driving means, and the valve is opened / closed during the color change to promptly discharge the old molding material adhering to the valve.

[0016]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings. First, the configuration of an injection molding machine, which is a molding machine, will be described. This injection molding machine, as shown in FIG.
A mold clamping device 1 and an injection device 2 which is a plasticizing device are provided, and these mold clamping device 1 and injection device 2 are arranged on a base 3. The mold clamping device 1 opens and closes a fixed mold 5 and a movable mold 6 which are hot runner molds 4 which are molds, and a fixed platen 7 to which the fixed mold 5 is detachably attached and a movable mold 6 are provided. The movable platen 8 is detachably attached. This movable platen 8
Moves in a direction toward and away from the stationary platen 7 (a mold opening / closing direction) by, for example, a hydraulically driven mold clamping cylinder 9, whereby the stationary mold 5 and the movable mold 6 are moved.
To open and close.

The injection device 2 has an injection device base 11
Is supported on a rail 12 fixed on the base 3 so as to be slidable in a direction toward and away from the mold 4. The injection device base 11 is moved by driving a hydraulically driven shift cylinder 13, for example. The injection device 2 is of an in-line screw type, and is provided with a heating cylinder 17 having a tip connected to a nozzle 16 that is attached to and detached from the fixed mold 5 as the injection device base 11 moves. In this heating cylinder 17,
A heater 18, which is a heating means, is provided on the outer periphery, and a screw 19 is incorporated. Further, a hopper 20 as a material supply unit is provided on the end of the heating cylinder 17 opposite to the nozzle 16. This hopper 20
Is for supplying a molding material (pellets) such as a thermoplastic resin before plasticization and supplying the molding material to the heating cylinder 17 through a supply port 20A provided at the lower end. The screw 19 is connected via a rod 22 to a pressurizing device, for example, a hydraulically driven injection cylinder 21, which is driven in the axial direction thereof, that is, in the direction approaching and separating from the mold 4. Further, the gear 24 is spline-fitted to the spline cylinder 23 fixed to the rod 22 in a state where the gear 24 is slidable in the axial direction of the screw 19 and the rod 22 and is prevented from rotating. A gear 26 fixed to the rotation output shaft of the motor 25 meshes with the gear 24. That is, the screw 19 is rotated by the drive of the motor 25.

Next, the structure of the hot runner die 4 will be described with reference to FIGS. 1 and 2. The fixed mold 5 and the movable mold 6, which are mold bodies, form a product-shaped product cavity 31 between them when the mold is closed. Fixed type 5
Is a fixed-side mold plate 32, a fixed-side receiving plate 33 fixed to the rear surface of the fixed-side mold plate 32, that is, the surface opposite to the movable mold 6,
A fixed side mounting plate 35 fixed via a spacer block 34 is provided on the back side of the fixed side receiving plate 33, and a support plate 36 is provided between the fixed side mounting plate 35 and the fixed side receiving plate 33. Manifold 37 is provided with intervening.
A cavity block 38 that forms the product cavity 31 is embedded and fixed to the fixed-side template 32.

The manifold 37 has a sprue bush.
41 is fixed. The sprue bush 41 projects toward the fixed-side mounting plate 35 and is located in a through hole 42 formed in the fixed-side mounting plate 35. A sprue 43, which is a material passage, is formed inside the sprue bush 41, and a band heater 44, which is a heating unit, is provided on the outer periphery of the sprue bush 41.
By the heating of the heater 44, the thermoplastic resin as the molding material in the sprue 43 is always kept in a molten state. A runner 45, which is a material passage, is formed inside the manifold 37.
The sprue 43 communicates with the entrance of 45. further,
The manifold 37 is provided with a heater 46 which is a heating means, and the heater 46 heats the runner 45.
The molding material inside is always kept in a molten state. A locate ring 47 is fixed to the surface of the fixed-side mounting plate 35 opposite to the manifold 37 so as to surround the through hole 42.

Further, a through hole 51 is formed from the fixed side receiving plate 33 to the cavity block 38, and a tip end portion of the through hole 51 serves as a gate 52 opening to the product cavity 31. The gate 52 has a cylindrical shape, and its axial direction coincides with the mold opening / closing direction.

The fixed mold 5 is provided with the gate 52.
A valve device 56 for opening and closing is installed. Next,
The configuration of the valve device 56 will be described. A substantially cylindrical valve casing 57 is incorporated in the through hole 51. A flange portion 58 is formed at one end of the valve casing 57 and is fixed to the manifold 37 and the fixed side receiving plate 33. The inside of the valve casing 57 has a material passage 59 having one end communicating with the outlet of the runner 45 in the manifold 37 and the other end communicating with the gate 52. The material passage 59 has a substantially columnar shape, but three or more support blades 60 extending in the mold opening / closing direction are integrally formed on the inner peripheral surface of the tip end portion on the gate 52 side. These support vanes 60 are located radially with respect to the central axis of the material passage 59. In addition, the valve casing 57
The inner material passage 59 has a columnar portion 61 at a portion closer to the gate 52 than the supporting blade 60. The inner peripheral surface of the columnar portion 61 is located substantially on the same cylindrical surface as the inner edge of the support blade 60.

A valve pin 66 as a valve is built in the valve casing 57. The valve pin 66 has the mold opening / closing direction as an axial direction, and a columnar gate closing portion 67 formed at the end portion on the product cavity 31 side is removably fitted into the gate 52 so that the gate 52 is closed.
Is to close. Further, the valve pin 66 is a through hole formed in the manifold 37 and the fixed side mounting plate 35.
A hydraulic cylinder device 70, which penetrates 68 and 69 and is provided on the fixed side mounting plate 35 as a fluid pressure cylinder device.
Are linked to. And this hydraulic cylinder device 70
Is driven to move the valve pin 66 in the mold opening / closing direction. The hydraulic cylinder device 70 is connected to a hydraulic circuit 71 provided outside the mold 4.

The outer peripheral surface of the valve pin 66 is always slidably in contact with the inner edge of the support blade 60 of the valve casing 57. This allows the valve pin 66 gate
The tip end on the 52 side is supported, but when the valve pin 66 closes the gate 52, the valve pin 66 fits into the cylindrical portion 61. On the other hand, when the gate 52 is opened, the tip of the valve pin 66 is located at the middle portion of the support blade 60. In addition, the valve pin
66 is supported by a guide bush 72 fixed in the valve casing 57 at the end of the valve casing 57 on the manifold 37 side. That is, the valve pin 66 slidably penetrates through the guide bush 72.

On the outer peripheral surface of the valve casing 57, a band heater 73 for heating the material passage 59 and a substantially cylindrical heater cover for covering the heater 73 from the outside are provided.
74 is fitted. Further, a temperature sensor 75 is provided along the heater 73. The molding material in the material passage 59 is always kept in a molten state by heating the heater 73.

Further, the gate of the valve casing 57
A fixing ring 76 is fitted and fixed to the outer peripheral side of the tip end on the 52 side. The outer peripheral surface of the fixing ring 76 is fitted into the cylindrical fitting surface 77 of the same diameter formed in the through hole 51. As a result, the valve casing 57 is supported by the cavity block 38 at its gate 52 side tip portion. The fixing ring 76 and the cavity block 38
Except for the mating surface 77 with the
Inner surface of valve casing 57 or heater cover 74
A gap is formed between the outer surface and the outer surface. This gap is
The heater 73 side and the gate 52 side are blocked by the fixing ring 76. The portion on the heater 73 side forms an air heat insulating layer 78, and the portion on the gate 52 side forms a resin heat insulating layer 79 communicating with the material passage 59 and the gate 52 and filled with a molding material. This resin heat insulation layer 79
May be filled in advance with a sealing ring made of a thermosetting resin or the like having excellent heat insulating properties that does not melt with the heat of the molten molding material.

The movable die 6 includes a movable side mold plate 81, a movable side receiving plate 82 fixed to a back surface of the movable side mold plate 81, that is, a surface opposite to the fixed mold 5, and the movable side receiving plate 82. And a movable side mounting plate (not shown) fixed via a spacer block (not shown). A core block 83 forming the product cavity 31 is embedded and fixed to the movable side mold plate 81. Further, although not shown, the movable die 6 is also provided with an ejection mechanism for ejecting the molded product to release it.

Next, the control means 91 will be described with reference to FIG. In the figure, reference numeral 92 is a control device, which is provided with a timer 92A for setting material change and color change time. The valve driving means for driving the valve pin 66 includes the hydraulic cylinder device 70 and the hydraulic circuit 71, and the control device 92 for controlling the hydraulic cylinder device 70 via the hydraulic circuit 71.
And a switch for operating the control device 92, and an operation means 93 such as a normal continuous molding operation unit 93A, a material change operated when changing material and a color change, and a change operation unit 93B for color change. It has and. Further, a screw position detection unit 94 is connected to the control device 92. The screw position detector 94 is provided in the heating cylinder 17, for example, and detects the position of the tip 19A of the screw 19. The screw position detection unit 94 does not directly detect the position of the screw 19 but may be, for example, an injection cylinder.
Alternatively, the position of the rod 22 may be detected by 21, and the position of the screw 19 may be calculated and detected based on this detection. Further, the control device 92 includes the mold clamping cylinder 9, the shift cylinder 13, and the heater 1.
8. The injection cylinder 21 and the motor 25 are connected.

Then, as a device used for material change and color change in the hot runner mold 4, the mold is opened and the molding material in the product cavity 31 is taken out, and then the heater 18 is operated in the mold open state and further. The position of the screw 19 is detected by the screw position detection unit 94, and the injection cylinder 21 is operated to measure the position of the screw 19, that is, the tip 19A of the screw 19 is connected to the supply port 20A of the hopper 20.
When the screw 19 moves backward so as to be arranged further forward, the injection cylinder 21 is operated to apply back pressure to move the screw 19 forward. That is, the tip 19A is the supply port
Apply back pressure to the screw 19 so that it will not retract from 20A,
A space L between the nozzle 16 and the tip 19A is secured, and a space for accommodating the molten molding material between the nozzle 16 and the tip 19A is secured. Further, the control device 92 has a function of operating the hydraulic circuit 71 and the hydraulic cylinder device 70 to automatically reciprocate the valve pin 66 to open and close.

Next, a molding method using the injection molding machine and the hot runner mold 4 will be described with reference to FIG. In the injection molding machine, continuous molding operation unit 93A
By operating the, the mold closing device 1 repeats the mold closing and mold opening, and the injection device 2 repeats the measuring process, the injection process and the pressure holding process. In the weighing process, the hopper
While the thermoplastic resin pellets, which is a raw material, are supplied from 20 to the heating cylinder 17, the molding material in the heating cylinder 17 is melted and plasticized by the heating force of the heater 18 and the shearing force of the rotation of the screw 19, The molten molding material is sent to and stored in the heating cylinder 17 on the nozzle 16 side (front side). At that time, screw 19
Moves backward from the mold 4.

Then, the fixed mold 5 and the movable mold 6 are closed, and a product cavity is provided between the fixed mold 5 and the movable mold 6.
After 31 is formed and a predetermined amount of molding material is accumulated in the front part of the heating cylinder 17, as shown in FIG. 1, the hydraulic cylinder device 70 is driven to move the valve pin 66 in the direction away from the movable mold 5. Then, the gate 52 is opened. After that, the screw 19 advances toward the mold 4 side by driving the injection cylinder 21, and the molding material in the heating cylinder 17 is injected from the nozzle 16 into the mold 4 and supplied (injection step). The injected molding material passes through the sprue 43, the runner 45 of the manifold 37, the material passage 59 in the valve casing 57, and the support blade 60 to which the valve pin 66 is fitted.
It flows from the gate 52 into the product cavity 31 through the space and the cylindrical portion 61. In this way the product cavity 31
After the inside is filled with the molding material, the back pressure applied from the injection cylinder 21 to the screw 19 holds the pressure (pressure holding step). After that, as shown in FIG. 2, the valve pin 66 moves toward the movable die 6 and is fitted into the gate 52, and
Close 52. As a result, the molding material in the material passage 59 and the molding material in the product cavity 31 are shut off from each other. After the pressure-holding process, the injection device 2 starts the weighing process again.

Further, the molding material in the mold 4, that is, the molded product is sufficiently cooled to be solidified (cooling step), and then the fixed mold 5 and the movable mold 6 are opened to mold the molded product. It is taken out by a take-out device not shown.
After that, the mold is closed again, and the molding cycle including the above steps is repeated. Meanwhile, the molding material in the material passage 59 of the sprue 43, the runner 45 and the valve casing 57 is always kept in a molten state by the heating of the heaters 44, 46 and 73.

Next, a material changing method such as material changing and color changing will be described with reference to FIG. The color change is to form a product of the same shape and different color by using the same mold 4 and changing only the molding material with a different pigment or dye. When changing the material, that is, switching from the old molding material to the new molding material, the hopper 20
A thermoplastic resin pellet, which is a new molding material, is supplied for color change, and the molding material switching operation section 93B of the operation means 93 is supplied.
When you operate, the timer 92A is set for a predetermined time in advance.
Starts timing. Then, the mold is opened by the mold clamping device 1, pellets of thermoplastic resin as a molding material are supplied from the hopper 20 into the heating cylinder 17, and the heater 18
The molding material in the heating cylinder 17 is melted and plasticized by the heating of and the shearing force generated by the rotation of the screw 19, and the molten molding material is sent to the nozzle 16 side (front side) in the heating cylinder 17 and stored therein. . Then, the fixed mold 5 and the movable mold 6 are left open, and after a predetermined amount of molding material is accumulated in the front part of the heating cylinder 17, as shown in FIG.
As shown in FIG. 5, the valve pin 66 is moved in the direction away from the movable die 5 by driving the hydraulic cylinder device 70, and the gate 52
Is released. Further, the screw 19 rotates, the molding material in the heating cylinder 17 is discharged from the nozzle 16 to the fixed mold 5 in an open state, and the valve pin 66 is opened by the hydraulic circuit 71 and the hydraulic cylinder device 70 via the control device 92. The valve pin 66 is reciprocated a plurality of times continuously or intermittently, thereby opening and closing the valve pin 66 a plurality of times. This molding material is
It passes through the sprue 43, the runner 45 of the manifold 37, the material passage 59 in the valve casing 57, the support blades 60 to which the valve pin 66 is fitted, and the cylindrical portion 61 to melt and plasticize from the gate 52. It is ejected and discharged to, for example, a discharge tray (not shown). The molding material contained in the discharge tray is cooled and solidified. At this time, when the screw 19 retracts and the tip 19A thereof retracts from the supply port 20A, the screw position detection unit 94 detects this and the control device
Back pressure is raised by the injection cylinder 21 via 92, and pressure is maintained so that the tip 19A of the screw 19 is arranged in front of the supply port 20A. As a result, the tip 19A is the supply port 20A.
It is controlled so that it is always placed on the front side. in the meantime,
The molten molding material in the heating cylinder 17 passes through the nozzle 16 and sprue 43, runner 45 and valve casing.
The molding material in the material passage 59 of 57 is always kept in a molten state by the heating of the heaters 44, 46, 73 and can be sequentially injected to switch to a new molding material. Further, the reciprocating movement of the valve pin 66 is automatically performed by driving the valve driving means of the hydraulic cylinder 70 and the hydraulic circuit 71.

With the reciprocating movement of the valve pin 66, the valve pin 66 and the gate 52 slide or the material passage passes.
By vibrating or pulsating the molding material in 59, the discharge of the former molding material remaining in the material passage 59 is promoted. In particular, the molding material adhering to the outer surface of the valve pin 66, the material passage 59 or the inner wall surface of the gate 52 is scraped off. Further, the discharge of the molding material before entering the resin heat insulating layer 79 is also promoted. Furthermore, the gate of the molding material in the material passage 59 is pushed by the valve pin 66.
Discharge from 52 to product cavity 31 is also facilitated. As a result, the previous molding material in the material passage 59 can be promptly and reliably replaced with the next molding material, the waste of the molding material can be reduced, and the productivity can be improved. Moreover, since the reciprocating motion of the valve pin 66 is automatically controlled until the set time by the timer 92A is completed after the material changing operation is started by operating the switching operation section 93B of the operation means 93, it does not take time and effort.

As described above, in the above-described embodiment, the mold clamping device 1 is provided on one side of the base 3 and the injection device 2 is provided on the other side of the base 3, and the injection device 2 includes the nozzle 16. The screw 19 is built into the heating cylinder 17 that is formed on the tip and the hopper 20 is provided on the base side.
An injection cylinder 21 is connected to the mold via a rod 22, and a movable mold 6 and a fixed mold 5 forming a product cavity 31 are attached to the mold clamping device 1 and the injection device 2, respectively, and a sprue 43 of the fixed mold 5, In the material change and color change method in the injection molding machine in which the nozzle 16 is connected to the runner 45, the tip 19A of the screw 19 is arranged in front of the supply port 20A of the hopper 20 and rotated, and the inside of the heating cylinder 17 is rotated. By discharging the molten molding material from the sprue 43 through the gate 52 to the product cavity 31 provided in the fixed mold 5, the molding material in a molten state continuously passes through the sprue 43 and the gate 52. The heating cylinder 17, the sprue 43, the runner 45, the material passage 59, and the old molding material in the gate 52 are quickly discharged,
It is possible to change materials and colors in place of new molding materials.

Further, the gate provided on the fixed die 5
52 is opened and closed by a valve pin 66, and by opening and closing the valve pin 66 during material change and color change, old molding material such as adhered to the valve pin 66 can be quickly discharged.

Further, the mold clamping device 1 is provided on one side of the base 3, and the injection device 2 is provided on the other side of the base 3. The injection device 2 has a nozzle 16 formed at its tip and a hopper 20. Screw to the heating cylinder 17 provided on the base end side
19 is built in, an injection cylinder 21 is connected to this screw 19 via a rod 22, and a movable mold 6 and a fixed mold 5 that form a product cavity 31 are attached to the mold clamping device 1 and the injection device 2, respectively, and The fixed type 5 sprue 43
In the injection molding machine in which the nozzle 16 is connected to, the screw position detection unit 94 of the screw 19 is provided, the screw position detection unit 94 is connected to the control device 92, and the injection cylinder 21 is connected to the control device 92. Then, the material is changed by the control device 92 based on the screw position detection unit 94, the injection cylinder 21 is operated at the time of color change, and the holding pressure is set so that the tip 19A of the screw 19 is arranged in front of the supply port 20A. Done, nozzle 16 and tip 19A
It is possible to reliably perform the material change and the color change by ensuring the space L between them and the space for accommodating the molten molding material between the nozzle 16 and the tip 19A.

Moreover, the gate provided on the fixed die 5
52 is opened / closed by a valve pin 66, and by providing a valve driving means such as a hydraulic cylinder 70 and a hydraulic circuit 71 that cause the control means 92 to reciprocate a plurality of times during the material change and color change of the valve pin 66, The old molding material such as adhered can be promptly discharged.

Further, since the control device 92 is provided with the timer 92A for setting the material change and color change time, the material is automatically changed and the color is changed until the set time of the timer 92A is reached after the switching operation section 93B is operated. Can be changed.

FIG. 7 shows a second embodiment of the first embodiment.
The same parts as those in the embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In the first embodiment, the control device 92 of the control means 91 operates the driving means such as the hydraulic cylinder 70 and the hydraulic circuit 71. In the second embodiment, however, the die itself has the hydraulic cylinder 70 and the hydraulic circuit. An operation unit 101 for operating valve driving means such as 71 is attached externally. That is, a switching operation unit 93B for material change and color change is provided in the external operation unit 101 instead of the operation on the injection molding machine side. The valve pin 66 is moved in the mold opening / closing direction by driving the hydraulic cylinder device 70. This hydraulic cylinder device 70 is connected to a hydraulic circuit 71 provided outside the mold 4, and this hydraulic circuit
In addition to the existing control device 102 on the injection molding machine side provided with a normal continuous molding operation part 93A, an external control device 103 equipped with a switching operation part 93B for material change and color change is connected to 71. ing. Therefore, in a normal state, the normal continuous molding operation unit 93A is operated to control the injection molding machine by the control device 102 to mold a molded product. On the other hand, when changing the material or the color, the control device 102 is manually controlled to control the injection cylinder 2
1 is operated to maintain the pressure so that the tip 19A of the screw 19 is located in front of the supply port 20A, and the distance L between the nozzle 16 and the tip 19A, and thus the molten state between the nozzle 16 and the tip 19A, By securing a space for containing the molding material and allowing the molten molding material to continuously pass through the sprue 43 and the gate 52, the old molding material in the heating cylinder 17, the sprue 43, and the gate 52 is promptly discharged. At this time, the control device 10 is operated by operating the switching operation section 93B for material change and color change.
By controlling the hydraulic cylinder device 70 to change the material and reciprocate a plurality of times during the color change, the old molding material attached to the gate 52 and the like can be reliably discharged.

In this way, the molding material in the sprue 43 is always kept in a molten state, and the sprue 43 moves from the product cavity to the product cavity.
A material changing and color changing device used for switching a molding material in a mold that opens and closes a gate 52 to 31 by a valve pin 66, and includes a hydraulic cylinder device 70 and a hydraulic circuit 71 that reciprocate the valve pin 66 a plurality of times. By providing the valve drive means and the control device 103 provided with the switching operation section 93B for material change and color change connected to the valve drive means including the hydraulic cylinder device 70 and the hydraulic circuit 71 and the like, the operation section 93B is provided. The valve pin 66 can be easily reciprocated simply by operating. Also, no major modification is required on the injection molding machine side.

Moreover, with the reciprocating movement of the valve pin 66, the valve pin 66 and the gate 52 slide or the material passage
By vibrating or pulsating the molding material in 59, the discharge of the former molding material remaining in the material passage 59 is promoted. In particular, the molding material adhering to the outer surface of the valve pin 66, the material passage 59 or the inner wall surface of the gate 52 is scraped off. Further, the discharge of the molding material before entering the resin heat insulating layer 79 is also promoted. Furthermore, the gate of the molding material in the material passage 59 is pushed by the valve pin 66.
Discharge from 52 to product cavity 31 is also facilitated. As a result, the previous molding material in the material passage 59 can be promptly and reliably replaced with the next molding material, the waste of the molding material can be reduced, and the productivity can be improved. Moreover, since the reciprocating movement of the valve pin 66 is automatically controlled after the molding material switching operation section 93B of the operation means 93 is operated to start the material change, no trouble is required.

The present invention is not limited to the above embodiment, but various modifications can be made within the scope of the present invention.

[0043]

According to the invention of claim 1, a mold clamping device is provided on one side of the base and an injection device is provided on the other side of the base, and the injection device has a nozzle formed at the tip. A screw is built in a heating cylinder with a material supply unit on the proximal side, a pressurizing device is connected to this screw, and a movable mold and a fixed mold that form a product cavity are attached to the mold clamping device and the injection device, respectively. Together with the material change in the injection molding machine in which the nozzle is connected to the fixed type material passage, in the color change method, while the tip of the screw is arranged in front of the raw material supply unit and rotated,
Melt molding material in the heating cylinder is discharged from the material passage through a gate to a product cavity provided in the fixed mold, there is a material change in an injection molding machine, a color change method, The molten molding material is discharged from the gate through the material passage, and the material and the color can be efficiently changed in a short time.

According to a second aspect of the present invention, the gate provided on the fixed mold is opened and closed by a valve, and the valve is opened and closed during a material change and a color change.
It is a method of material change and color change in the injection molding machine described, and it is possible to reliably discharge the old molding material adhering to the valve etc. by changing the material of the valve and opening / closing operation during the color change. Waste can be reduced and productivity can be improved.

According to a third aspect of the present invention, the mold clamping device is provided on one side of the base, and the injection device is provided on the other side of the base.
The injection device has a screw built in a heating cylinder having a nozzle formed at the tip and a material supply unit provided at the base end, and a pressurizing device is connected to the screw, and a product cavity is provided in the mold clamping device and the injection device. In the injection molding machine in which the movable mold and the fixed mold that form the above are respectively attached, and the nozzle is connected to the material passage of the fixed mold, the position detecting means of the screw is provided and the position detecting means is connected to the control device. The injection molding machine is characterized in that a pressure device is connected to the control device, and the control device operates the pressure device at the time of material change and color change based on the position detection means. The heating cylinder is placed at a predetermined position by the position detection means, and the molding material melted from inside the heating cylinder is discharged from the gate through the material passage. Material replacement, can be carried out in a short period of time well color change efficiency Te.

According to a fourth aspect of the present invention, the gate provided on the fixed mold is opened and closed by a valve, and the valve driving means is provided for reciprocating the valve a plurality of times during material change and color change. The injection molding machine according to claim 3, wherein the valve is opened / closed during material change and color change to reliably discharge the old molding material attached to the valve.

The invention of claim 5 is the injection molding machine according to claim 4, characterized in that the control device is provided with a timer for material change and color change time setting. The time can be adjusted automatically.

According to a sixth aspect of the invention, the molding material in the material passage is always kept in a molten state, and the material used for switching the molding material is a mold for opening and closing the gate from the material passage to the product cavity by a valve. A color changing device,
A material changing and color changing device for a mold, comprising valve driving means for reciprocating the valve a plurality of times, and an operating portion connected to the valve driving means. By means of the means, the valve is changed in material, and the valve is opened / closed during the color change to quickly and surely discharge the old molding material adhering to the valve.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a hot runner die according to an embodiment of a material changing device for a hot runner die of the present invention.

FIG. 2 is an enlarged cross-sectional view near the gate of the same.

FIG. 3 is a side view showing a cross section of a part of the same injection molding machine.

FIG. 4 is a block diagram of the same.

FIG. 5 is a timing chart of each step when molding the same product.

FIG. 6 is a time chart of material change and color change of the above.

FIG. 7 is a cross-sectional view of a hot runner die showing another embodiment of the material changing device in the hot runner die of the present invention.

[Explanation of symbols]

1 Mold clamping device 2 injection device 3 bases 4 Hot runner mold 5 fixed type 6 movable 16 nozzles 17 heating cylinder 19 screw 19A tip 20 Hopper (Material Supply Department) 20A supply port 21 injection cylinder 31 Product Cavity 43 Sprue (material passage) 45 runner (material passage) 52 gates 59 Material passage 66 Valve Pin (Valve) 92A timer 94 Screw position detector (screw position detector)

Claims (6)

[Claims] 1. A mold clamping device is provided on one side of a base, and an injection device is provided on the other side of the base. The injection device has a nozzle formed at the tip and a material supply unit on the base side. The heating cylinder provided has a screw built-in, a pressurizing device is connected to this screw, and a movable mold and a fixed mold that form a product cavity are attached to the mold clamping device and the injection device, respectively, and the material passage of the fixed mold. In the material change in the injection molding machine in which the nozzle is connected to, in the color change method, the tip of the screw is arranged in front of the raw material supply section and rotated, and the molten molding material in the heating cylinder is discharged from the material passage. Material change in an injection molding machine, characterized by discharging through a gate to a product cavity provided in the fixed mold,
How to change colors. 2. A material change and color change in an injection molding machine according to claim 1, wherein a gate provided on the fixed mold is opened and closed by a valve, and the valve is opened and closed during a material change and color change. How to change 3. A mold clamping device is provided on one side of the base, and an injection device is provided on the other side of the base. The injection device has a nozzle formed at the tip and a raw material supply section provided at the base. The heating cylinder incorporates a screw, the pressurizing device is connected to the screw, and the movable mold and the fixed mold that form the product cavity are attached to the mold clamping device and the injection device, respectively, and the material passage of the fixed mold is connected. In the injection molding machine to which the nozzle is connected, the position detecting means for the screw is provided, the position detecting means is connected to a control device, and the pressurizing device is connected to the control device, based on the position detecting means. An injection molding machine, characterized in that the control device operates the pressurizing device at the time of material change and color change. 4. The gate provided to the fixed mold is opened and closed by a valve, and a valve drive means for reciprocating the valve a plurality of times during material change and color change is provided. Injection molding machine. 5. The injection molding machine according to claim 4, wherein the controller is provided with a timer for setting material change and color change time. 6. A material changing and color changing device used for switching a molding material in a mold in which a molding material in a material passage is always kept in a molten state and a gate from the material passage to a product cavity is opened and closed by a valve. And a device for changing the material of the mold and a color changing device, comprising: a valve driving means for reciprocating the valve a plurality of times; and an operating portion connected to the valve driving means.