CN108457954A - A semi-hollow self-piercing riveting screw with fastening thread and self-piercing riveting equipment and method - Google Patents

Abstract

The invention provides a semi-hollow self-piercing riveting screw with fastening threads, which is characterized by comprising a rivet main body with a semi-hollow structure and a thread head with the fastening threads, wherein the thread head is arranged on the upper end surface of the rivet main body, the bottom of the thread head is provided with a tool withdrawal groove which is convenient for tool withdrawal after thread machining is finished, and the outer diameter of the rivet main body is the same as that of the thread head. The invention also discloses self-piercing riveting equipment and a self-piercing riveting method applying the riveting screw, wherein the riveting forming of a thinner plate is realized by pushing the semi-hollow self-piercing riveting screw through the improved self-piercing riveting punch rod, and then the mechanical connection between thicker plates is realized through a thread mechanism. The invention has simple structure, convenient processing and manufacturing and low cost, overcomes the limitation of the thickness of the plate riveted by the traditional semi-hollow self-punching riveting screw and can realize the mechanical connection between three layers or multiple layers of thicker plates.

Description

A semi-hollow self-piercing riveting screw with fastening thread and self-piercing riveting equipment and method

technical field

The invention belongs to the field of connecting metal and non-metal plates, and in particular relates to a semi-hollow self-piercing riveting screw with fastening threads and self-piercing riveting equipment and method, especially suitable for the same type and different type with high strength and thickness Mechanical connection of metallic materials and most non-metallic materials.

Background technique

Thin metal and non-metal sheets are widely used in the machinery industry and the automobile industry. Self-piercing riveting technology is a new type of thin sheet connection technology that replaces traditional resistance spot welding. It does not require pre-punching like traditional riveting technology. The process is simple, and the semi-hollow self-piercing rivet and the light alloy plate are plastically deformed together to form a mechanical inner lock and realize a firm mechanical connection; it is especially suitable for the tightness of 2-6mm light alloy and composite material plates that are difficult to weld. However, due to the limitation of the rivet material and its size, the plastic deformation of the rivet during the riveting forming process should not be too large, otherwise it will cause the rivet to break and fail. Connections created difficulties.

A utility model patent (application number 201520328312.5) discloses a threaded rivet. The patent adds a drill head to the head of the rivet to realize one-step riveting by removing material. The requirements are high, the cost is high, and it is not suitable for the riveting process of the existing semi-hollow self-piercing riveting equipment. The internal thread involved in this patent is to be fixed on the riveting gun, and has no actual connection function.

Therefore, it is necessary to provide a self-piercing riveting screw and equipment to solve the connection problem between thicker and multi-layer plates.

Contents of the invention

According to the technical problem raised above, a semi-hollow self-piercing riveting screw with fastening thread and self-piercing riveting equipment and method are provided. The present invention mainly utilizes the thread mechanism designed on the basis of the traditional semi-hollow self-piercing riveting screw, and designs the semi-hollow self-piercing riveting screw and the thread mechanism as a whole. The riveting and forming of thin sheets, and then the mechanical connection between thicker sheets is realized through the screw mechanism, so as to realize the connection of multi-layer sheets in different thickness ranges.

The technical means adopted in the present invention are as follows:

A semi-hollow self-piercing riveting screw with a fastening thread, characterized in that the semi-hollow self-piercing riveting screw with a fastening thread includes a rivet body with a semi-hollow structure and an upper end surface of the rivet body A thread head with a fastening thread, the bottom of the thread head is provided with a tool relief groove for tool retraction after the thread processing is completed, and the outer diameter of the rivet body is the same as the outer diameter of the thread head.

Further, the thread head is used for connecting thicker plates, and has M3-M8 coarse-pitch common thread and fine-pitch common thread, and its nominal length is 12mm-22mm.

The invention also discloses a self-piercing riveting device, which is characterized in that the above-mentioned semi-hollow self-piercing riveting screw with fastening thread is used, and the punch rod inside the self-piercing riveting head used in conjunction with it is provided with a The light hole of the semi-hollow self-piercing riveting screw with fastening thread, the light hole cooperates with the top of the thread head to ensure the centering of the riveting forming process; the self-piercing riveting equipment also includes a nesting The blank holder arranged on the outside of the self-piercing riveting punch and the self-piercing riveting lower die set up and down opposite to the blank holder, stack the upper and lower sheets to be riveted up and down on the self-piercing riveting On the lower mold, after the self-piercing riveting punch drives the blank holder to move down and the self-piercing lower mold is closed, the semi-hollow self-piercing riveting screw with fastening thread is pushed to make the The main body of the rivet forms a mechanical interlock with the upper plate and the lower plate, and then realizes the connection with the thicker plate through the screw mechanism of the thread head.

Further, the material of the upper plate and the lower plate is selected from one of high-strength light alloy, high-strength steel plate, low-strength carbon steel or non-metallic composite material; the thicker plate refers to a metal material with poor plasticity or non-metallic materials.

Further, the plate thickness of the upper plate and the lower plate is 2mm-6mm, and the plate thickness of the thicker plate is 4mm-16mm.

The present invention also discloses a method for riveting multi-layer plates using the above-mentioned self-piercing riveting equipment, which is characterized in that it includes the following steps:

S1. Stack the upper and lower sheets to be riveted on the lower self-piercing riveting mold;

S2. After the self-piercing riveting punch drives the blank holder to move down and the self-piercing riveting die is closed, push the semi-hollow self-piercing riveting screw with fastening thread to make the rivet forming a mechanical interlock between the main body and said upper and lower sheets;

S3. Realize the connection with the thicker plate through the screw mechanism of the thread head, so as to realize the connection of multi-layer plates in different thickness ranges.

Further, when riveting high-strength lightweight alloys or high-strength steel plates, the step S1 also includes putting the upper and lower plates to be riveted into a heating furnace for heating, so that the temperature quickly reaches the preset solid solution temperature, After a period of heat preservation, the solute atoms are fully dissolved into the matrix to obtain a saturated solid solution, and then the two-layer plate after solid solution is quickly transferred to the self-piercing riveting die to prepare for the self-piercing riveting of step S2, and then the riveted parts are protected. Press quenching.

Compared with the prior art, the semi-hollow self-piercing riveting screw with fastening thread of the present invention can be used for the connection of most non-metallic material plates such as light alloy, carbon steel and composite materials, and can be used for high-strength light alloy and high-strength The warm riveting between steel plates improves the formability of materials through heat treatment, and can realize self-piercing riveting at high temperature, and achieve mechanical connection with other high-strength materials or composite materials with poor plasticity through threads. The forming process of the self-piercing riveting of the present invention is to form a mechanical interlock through the expansion of the tail of the rivet, so as to realize an effective mechanical connection, and the thread head can be used to connect other plates with a larger thickness, and has the actual connection function.

The present invention has the following advantages:

1) Overcoming the limitation of the thickness of the riveted sheets by traditional semi-hollow self-piercing rivets, the mechanical connection between three or more thicker sheets can be realized.

2) High-strength lightweight alloys and high-strength steels can be riveted with semi-hollow self-piercing riveting screws with fastening threads after proper heat treatment process to obtain better quality joints.

3) The connection between heterogeneous plates with poor plasticity such as composite materials and carbon fibers can be realized.

4) The semi-hollow self-piercing riveting screw with fastening thread of the present invention has a simple structure, is easy to process and manufacture, and has low cost.

Based on the above reasons, the present invention can be widely promoted in the field of riveting of multilayer plates.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is a schematic structural view of the semi-hollow self-piercing riveting screw with fastening thread of the present invention.

Fig. 2 is a schematic diagram of applying the semi-hollow self-piercing riveting screw with fastening thread of the present invention to implement the connection of multi-layer plates in the embodiment.

Fig. 3 is a cross-sectional view of the semi-hollow self-piercing riveting screw and the riveting device with fastening threads of the present invention.

In the figure: 1, self-piercing riveting punch; 2, blank holder; 3, semi-hollow self-piercing riveting screw with fastening thread; 31, rivet main body; 32, thread head; 33, undercut groove; 4, Upper plate; 5. Lower plate; 6. Self-piercing riveting die.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1, a semi-hollow self-piercing riveting screw with a fastening thread, the semi-hollow self-piercing riveting screw 3 with a fastening thread includes a rivet body 31 with a semi-hollow structure and is arranged on the There is a threaded head 32 with fastening threads on the upper end surface of the rivet main body 31, and the bottom of the threaded head 32 is provided with a tool relief groove 33 that is convenient for threading to be retracted after the completion of the thread processing. The outer diameter of the rivet main body 31 is the same as that of the threaded head 32. same outer diameter. The thread head 32 is used for connecting thicker plates, and has M3-M8 coarse-pitch common thread and fine-pitch common thread, and its nominal length is 12mm-22mm.

As shown in Figure 3, the present invention also discloses a self-piercing riveting device, which uses the above-mentioned semi-hollow self-piercing riveting screw 3 with fastening threads, and the punch rod inside the self-piercing riveting punch 1 used in conjunction with it is equipped with a To accommodate the light hole of the semi-hollow self-piercing riveting screw 3 with fastening thread, the light hole cooperates with the top of the thread head 32 to ensure the centering of the riveting process; the self-piercing riveting The equipment also includes a blank holder 2 nested on the outside of the self-piercing riveting punch 1 and a self-piercing lower die 6 opposite to the blank holder 2 up and down. The plates 5 are stacked up and down and placed on the self-piercing riveting die 6, and the blank holder 2 is driven downward by the self-piercing riveting punch 1 to close the die with the self-piercing riveting die 6, and then push the The semi-hollow self-piercing riveting screw 3 with fastening threads, the legs of the rivet body 31 expand and drive the flow of the plate, and the rivet and the plate produce large plastic deformation at the same time, so that the rivet body 31 and the A mechanical interlock is formed between the upper plate 4 and the lower plate 5, and then the screw mechanism of the thread head 32 passes through the pre-drilled thicker plate, and is locked with a nut to realize the connection with the thicker plate. Connection, so as to realize the connection between three or more layers of thicker plates (as shown in Figure 2).

The material of the upper plate 4 and the lower plate 5 is selected from one of high-strength light alloy, high-strength steel plate, low-strength carbon steel or non-metallic composite material; the thicker plate refers to a metal material with poor plasticity or non-metallic materials.

The thickness of the upper plate 4 and the lower plate 5 is 2mm-6mm, and the thickness of the thicker plate is 4mm-16mm.

The present invention also discloses a method for riveting multi-layer plates using the above-mentioned self-piercing riveting equipment, which includes the following steps:

S1, stacking the riveted upper plate 4 and the lower plate 5 up and down on the self-piercing lower mold 6;

S2. After the self-piercing riveting punch 1 drives the blank holder 2 to move down and the self-piercing riveting lower mold 6 is molded, push the semi-hollow self-piercing riveting screw 3 with fastening thread Make the rivet body 31 form a mechanical interlock with the upper plate 4 and the lower plate 5;

S3. Realize the connection with the thicker plate through the screw mechanism of the thread head 32, so as to realize the connection of multi-layer plates in different thickness ranges.

When riveting high-strength lightweight alloys or high-strength steel plates, the step S1 also includes putting the upper plate 4 and the lower plate 5 to be riveted into a heating furnace for heating, so that the temperature quickly reaches the preset solid solution temperature, and the heat preservation After a period of time, the solute atoms are fully dissolved into the matrix to obtain a saturated solid solution, and then the solid-dissolved two-layer plate is quickly transferred to the self-piercing riveting die 6 to prepare for the self-piercing riveting of step S2, and then the riveted parts are protected. Press quenching, the riveted part is kept in the closed mold during cooling, and the double-layer sheet is kept under pressure to complete the in-mold quenching process.

Example 1

As shown in Figure 3, the upper plate 4 used in this embodiment is a 2mm thick 6061-T6 aluminum alloy, the lower plate 5 is a 3mm thick Q235 low carbon steel and a 4mm thick carbon fiber plate, the total thickness of the plates is 9mm, of which the yield strength of 6061-T6 aluminum alloy is 200-230Mpa, the tensile strength is 340-380Mpa, the yield strength of Q235 steel is 230-240Mpa, and the tensile strength is 370-500Mpa.

6061-T6 aluminum alloy and Q235 low-carbon steel can achieve good self-piercing riveting at room temperature, among which Q235 with better plasticity is placed in the middle as the lower plate 5, and 6061-T6 aluminum alloy is placed on the upper layer, which can be realized after positioning and clamping Riveting molding, carbon fiber sheet is not suitable for riveting due to its poor plasticity, so it is used as the uppermost sheet after pre-punching. After riveting, the threaded head 32 passes through the through hole of carbon fiber and is locked with a matching nut, so as to realize three layers of different thicknesses. Mechanical connection between heterogeneous sheets.

Example 2

As shown in Figure 3, the upper plate 4 and the lower plate 5 used in this embodiment are both 2mm thick 7075-T6 high-strength aluminum alloys, and a layer of 6mm thick high-strength steel plates. The total thickness of the plates is 10mm, of which 7075- The yield strength of T6 aluminum alloy is 480-520Mpa, and the tensile strength is 630-670Mpa; the yield strength of high-strength steel plate is 800-900Mpa, and the tensile strength is 1200-1300Mpa.

7075-T6 aluminum alloy cannot be riveted and formed at room temperature, so heat treatment is performed first to improve the formability of the material.

Firstly, the double-layer 7075-T6 aluminum alloy sheet to be riveted is heated and solution treated, wherein the solution temperature is 470-480°C, and the holding time is 25-35min. The formability of 7075 aluminum alloy is better at about 400°C, so the solution After completion, when the 7075 aluminum alloy cools down to 380-410°C, the self-piercing riveting punch 1 moves downward to push the semi-hollow self-piercing riveting screw 3 with fastening thread for riveting, and at the same time, the blank holder 2 and the self-piercing riveting die Under the action of 6, the 7075 aluminum alloy is quenched to strengthen the properties of the 7075 material matrix near the joint. After the temperature of the plate is lowered to below 100°C, the self-piercing riveting process of the double-layer lightweight plate is completed.

The double-layer self-piercing riveting joint cooled to normal temperature is penetrated into the thicker high-strength steel plate through the threaded head, and locked with nuts, finally realizing the connection of three thicker plates.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (7)

1. A semi-hollow self-piercing riveting screw with fastening thread, characterized in that, the semi-hollow self-piercing riveting screw (3) with fastening thread comprises a rivet body (31) with a semi-hollow structure and A threaded head (32) with a fastening thread arranged on the upper end surface of the rivet main body (31), the bottom of the threaded head (32) is provided with a tool relief groove (33) that facilitates the tool retraction after the thread processing is completed, and the The outer diameter of the rivet body (31) is the same as that of the threaded head (32). 2. The semi-hollow self-piercing riveting screw with fastening thread according to claim 1, characterized in that, the thread head (32) is used to connect thicker plates, and it has M3-M8 coarse teeth The nominal length of thread and fine thread is 12mm-22mm. 3. A self-piercing riveting device, characterized in that, the semi-hollow self-piercing riveting screw (3) with fastening thread described in claim 1 or 2 is applied, and the self-piercing riveting punch (1) used in conjunction with it The inner punch rod is provided with a light hole for accommodating the semi-hollow self-piercing riveting screw (3) with a fastening thread, and the light hole cooperates with the top of the thread head (32) to ensure riveting Centering of the process; the self-piercing riveting equipment also includes a blank holder (2) nested on the outside of the self-piercing riveting punch (1) and a blank holder (2) set up and down opposite to the blank holder (2). The lower self-piercing riveting mold (6), the upper layer plate (4) and the lower layer plate (5) to be riveted are stacked up and down on the lower self-piercing riveting mold (6), through the self-piercing riveting punch (1 ) to drive the blank holder (2) to move downwards and clamp the self-piercing lower mold (6), then push the semi-hollow self-piercing riveting screw (3) with fastening thread to make the rivet The main body (31) forms a mechanical interlock with the upper plate (4) and the lower plate (5), and then realizes the connection with the thicker plate through the screw mechanism of the thread head (32). 4. The self-piercing riveting device according to claim 3, characterized in that, the materials of the upper plate (4) and the lower plate (5) are selected from high-strength light alloy, high-strength steel plate, low-strength carbon steel or non-metallic One of composite materials; the thicker plate refers to metal materials or non-metal materials with poor plasticity. 5. The self-piercing riveting device according to claim 4, characterized in that, the plate thickness of the upper plate (4) and the lower plate (5) is 2mm-6mm, and the plate thickness of the thicker plate is 4mm -16mm. 6. A method for riveting multi-layer plates using self-piercing riveting equipment as claimed in claim 5, characterized in that it comprises the steps of: S1, stacking the riveted upper plate (4) and the lower plate (5) up and down on the self-piercing riveting lower mold (6); S2. After the self-piercing riveting punch (1) drives the blank holder (2) to move down and the self-piercing riveting lower mold (6) is mold-closed, push the half-air with the fastening thread The core self-piercing riveting screw (3) makes the rivet body (31) form a mechanical interlock with the upper plate (4) and the lower plate (5); S3. Realize the connection with the thicker plate through the screw mechanism of the thread head (32), so as to realize the connection of multi-layer plates in different thickness ranges. 7. The method for riveting multilayer plates according to claim 6, characterized in that, when riveting high-strength light alloy or high-strength steel plates, said step S1 also includes riveting the upper plate (4) and the lower plate to be riveted The plate (5) is heated in a heating furnace so that its temperature quickly reaches the preset solid solution temperature. After a period of heat preservation, the solute atoms are fully dissolved into the matrix to obtain a saturated solid solution, and then the two-layer plate after solid solution is quickly Transfer to the self-piercing riveting die (6) to prepare for the self-piercing riveting of step S2, and then carry out pressure-holding quenching to the riveted parts.