A quick die changing device for double wire riveter

Abstract

The utility model relates to riveting machine's technical field, specifically disclose a double riveting machine quick die changing device. Include: main die seat module, copper line mould and silver line mould, movable die set, one punch, two punches and positioning column, the positioning column sets up at least two roots under main die seat module, movable die set is equipped with at least four positioning column through -hole, the vertical distance of positioning column to positioning column through -hole is less than the vertical distance of one punch or two punches to main mould thimble, when one punch moves to with main mould thimble directly opposite and before the confluence, two positioning columns are inserted into two positioning column through -holes respectively, when two punches move to with main mould thimble directly opposite and before the confluence, two positioning columns are inserted into another two positioning column through -holes respectively. The scheme can ensure that silver-copper material section is pushed into the main mould central hole and is effectively corrected when horizontal deviation, thereby will significantly reduce silver layer deviation and head face copper leakage defect.

Description

Technical Field

[0001] This utility model relates to the technical field of rivets, and specifically discloses a quick mold changing device for a double-line riveting machine. Background Technology

[0002] Silver-copper composite contacts are core components in low-voltage electrical appliances, responsible for connecting and disconnecting current. Their typical structure consists of a silver or silver alloy layer covering the head, utilizing the excellent conductivity, resistance to welding, and arc erosion resistance of silver-based materials; the feet are made of copper or copper alloy, leveraging copper's high conductivity, high thermal conductivity, and low cost to achieve mechanical riveting and current carrying. Through this division of labor—with the silver layer handling electrical contact and the copper feet handling structure and conductivity—the contacts meet both electrical life and reliability requirements while also considering material costs, making them widely used in low-voltage electrical appliances such as relays, contactors, circuit breakers, and switches.

[0003] To efficiently manufacture these "silver head, copper foot" rivet-type contacts, double-wire riveting machines are commonly used in industry. Existing double-wire riveting machine models have a structure where copper wire is fed on one side and silver wire on the other, as referenced... Figure 1 The machine sequentially completes a multi-station cycle of "wire feeding - shearing - material delivery - pre-upsetting (first punch) - final upsetting (second punch) - ejection" to finish the electrical connection process. Compared to single-wire multiple processing or post-welding solutions, the double-wire riveting machine has advantages such as fast production cycle, high material utilization, and good bonding strength between the silver layer and the copper feet, and has become the mainstream equipment for mass production of composite contacts.

[0004] As electrical products increasingly demand higher performance from their electrical contacts, greater requirements are being placed on the dimensional accuracy, uniformity of silver layer distribution, and bonding strength of riveted contacts. However, current double-wire riveting machines suffer from the following problems: the position of the silver wire after cutting by the shears is unstable, leading to silver layer misalignment and inaccurate alignment with the head diameter. The concentricity deviation between the head and lead diameters can reach as high as 0.08mm, resulting in copper leakage on the head surface. Furthermore, the separate centering of the main and movable dies makes achieving concentricity difficult and highly dependent on the experience of the operators. Currently, the only solution to these problems is to increase the frequency of product inspection during production and make timely adjustments to the machine after problems occur, which increases production difficulty and raises potential quality risks. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a quick mold changing device for a double-wire riveting machine.

[0006] This utility model discloses a quick mold changing device for a double-wire riveting machine, which adopts the following technical solution:

[0007] A quick mold-changing device for a double-wire riveting machine includes:

[0008] The main mold base module is provided with an axially through main mold center hole and a main mold ejector pin that can slide axially in the main mold center hole;

[0009] The copper wire mold and the silver wire mold are respectively located on one side of the main mold ejector pin, and are used to feed copper wire and silver wire respectively;

[0010] The copper wire cutter and the silver wire cutter are respectively located on one side of the main mold base module, and are used to cut the copper wire and the silver wire respectively and send them to the center hole of the main mold.

[0011] The movable punching module is positioned above the main mold base module. The movable punching module has a first punch and a second punch distributed on both sides below it. The first punch and the second punch move with the movable punching module and their movement paths cover the positions of the first punch and the second punch corresponding to the ejector pins of the main mold, respectively.

[0012] At least two positioning pins are provided under the main mold base module, and the movable punch module is provided with at least four positioning pin through holes; the vertical distance from the positioning pin to the positioning pin through hole is less than the vertical distance from the first punch or the second punch to the main mold ejector pin; before the first punch moves to be directly opposite and engaged with the main mold ejector pin, the two positioning pins are respectively inserted into two of the positioning pin through holes; before the second punch moves to be directly opposite and engaged with the main mold ejector pin, the two positioning pins are respectively inserted into the other two positioning pin through holes.

[0013] Preferably, the movable punch module includes a movable punch base plate and a movable punch fixing plate detachably installed under the movable punch base plate, and the positioning post, the first punch and the second punch are installed on the movable punch fixing plate.

[0014] Preferably, a positioning pin and a positioning pin hole that matches and engages with the positioning pin are provided between the movable punch base plate and the movable punch fixing plate.

[0015] Preferably, the surface of the positioning post is provided with several annular grooves.

[0016] Preferably, the positioning post includes a first positioning post, a second positioning post, and a third positioning post. The first positioning post is located on the left front side of the first and second punches, the second positioning post is located on the right front side of the first and second punches, and the third positioning post is located on the rear side of the first and second punches.

[0017] Preferably, the main mold base module includes a main mold pad and a main mold base disposed on the main mold pad. The main mold base is provided with a main mold that cooperates with the first punch and the second punch for stamping. The positioning pin through hole is formed on the main mold base.

[0018] Preferably, the movable punching die assembly and the main die base assembly are cut from SKD-11 steel.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] This invention features at least two positioning pins below the main mold base module and two sets of positioning pin through holes corresponding to the positioning pins on the movable punch module. This allows the positioning pins to be inserted into the corresponding through holes before the first or second punch engages with the ejector pin of the main mold, achieving precise positioning and rigid connection between the movable punch and the main mold base. This forcibly corrects the concentricity of the two, ensuring that the lateral offset of the silver-copper material segment is effectively corrected when it is pushed into the center hole of the main mold. This significantly reduces silver layer misalignment and copper leakage defects on the head surface. At the same time, the positioning pin mating structure eliminates the need for dial indicator alignment during mold changes, enabling one-time positioning and immediate use, greatly shortening mold change time and effectively improving production efficiency and product qualification rate. Attached Figure Description

[0021] Figure 1 A schematic diagram of the production steps for silver-copper composite contacts;

[0022] Figure 2 This is a schematic diagram of the mold opening state of the quick mold changing device for the double-wire riveting machine in this embodiment;

[0023] Figure 3 This is a schematic diagram of the pre-upsetting state of the quick mold changing device for the double-wire riveting machine in this embodiment;

[0024] Figure 4 This is a schematic diagram of the final upsetting state of the quick mold change device for the double-wire riveting machine in this embodiment.

[0025] Explanation of icon numbers:

[0026] 1. Movable punch base plate; 2. Movable punch fixing plate; 3. Positioning pin; 4. First punch; 5. Second punch; 6. Copper wire shears; 7. Silver wire shears; 8. Main mold base; 81. Positioning pin through hole; 9. Main mold; 10. Copper wire mold; 11. Silver wire mold; 12. Main mold ejector pin; 13. Main mold pad plate. Detailed Implementation

[0027] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] This embodiment discloses a quick mold-changing device for a double-wire riveting machine, referring to... Figure 1-4The assembly includes a main mold base module, a copper wire mold 10 and a silver wire mold 11, copper wire cutters 6 and silver wire cutters 7, a movable punching die assembly, and at least two positioning pins 3. The main mold base module has an axially penetrating central hole and an axially sliding main mold ejector pin 12 is installed in the hole. The copper wire mold 10 and the silver wire mold 11 are respectively located on one side of the main mold ejector pin 12 for conveying copper wire and silver wire respectively. The copper wire cutters 6 and the silver wire cutters 7 are respectively located on the main mold base module for cutting the copper wire and silver wire and feeding them to the central hole of the main mold. The movable punching die assembly is located above the main mold base module. The movable punching die assembly has a first punch 4 and a second punch 5 distributed on both sides below it. The first punch 4 and the second punch 5 move with the movable punching die assembly. The moving path covers the positions directly opposite the main mold ejector pin 12; the positioning pin 3 is set below the main mold base module, and the movable punching die has at least four positioning pin through holes 81. The vertical distance from the positioning pin 3 to the positioning pin through hole 81 is less than the vertical distance from the first punch 4 or the second punch 5 to the main mold ejector pin 12; before the first punch 4 or the second punch 5 moves to be directly opposite and engages with the main mold ejector pin 12, the two positioning pins 3 are respectively inserted into the corresponding positioning pin through holes 81; an exhaust channel connecting the positioning pin through holes 81 can be provided in the main mold base module to allow compressed air to be discharged smoothly, reduce the air resistance when the positioning pin 3 is inserted into the positioning pin through hole 81, and ensure that the positioning pin 3 can be inserted smoothly.

[0029] Since the copper wire shears 6 and silver wire shears 7 only cut and feed the material segment to the opening of the center hole of the main mold, there may be slight left and right wobbling. However, by adopting the above solution, since there is a positioning post 3 between the main mold base module and the movable punch module, and the length of the positioning post 3 is greater than the length of the first punch 4 and the second punch 5, the positioning post 3 is pre-inserted into the positioning post through hole 81 before the head pin of the mold closing punch is pushed out. This makes the movable punch-main mold base a rigid frame, ensuring that the head pin axis and the main mold hole axis are absolutely coincident, effectively eliminating the concentric deviation between the main mold and the movable mold. Therefore, when the material segment is pushed into the center hole of the main mold by the head pin, its lateral displacement can be corrected, achieving forced centering. The concentricity is reduced from 0.08mm to below 0.03mm, and the qualification rate of the rivet contact is greatly improved. In addition, when mold changing is required, the movable punch die group can be precisely aligned with the main mold base through the positioning column 3, and then installed and fixed in the stamping drive device. This eliminates the need for dial indicator alignment, achieving one-time positioning and immediate use, reducing the mold changing time from 3 hours to less than 1 hour.

[0030] As a preferred embodiment, the movable punch assembly includes a movable punch base plate 1 and a movable punch fixing plate 2 detachably mounted under the movable punch base plate 1. Positioning pins 3, a first punch 4, and a second punch 5 are all mounted on the movable punch fixing plate 2. The fastening parts between the movable punch fixing plate 2 and the movable punch base plate 1 are arranged on the front of the riveting machine's operating area. This split design makes maintenance more convenient, eliminating the need for complete mold disassembly. The part requiring repair can be removed from the front simply by keeping the machine in the open mold position.

[0031] As a preferred embodiment, a positioning pin and a positioning pin hole that matches and engages with the movable punch base plate 1 and movable punch fixing plate 2 are provided between them. The movable punch base plate 1 and movable punch fixing plate 2 achieve precise positioning through the cooperation of the positioning pin and the positioning pin hole, so that the positioning accuracy is not affected when reinstalling after mold opening and maintenance.

[0032] As a preferred embodiment, the surface of the positioning post 3 is provided with several annular grooves. These annular grooves play an important role when the positioning post 3 and the positioning post through hole 81 are engaged: on the one hand, they can store lubricating oil, reduce friction between the positioning post 3 and the positioning post through hole 81, thereby reducing wear and extending the service life of the positioning post 3 and the positioning post through hole 81; on the other hand, the annular grooves can accommodate excess material generated by thermal expansion, reduce positioning deviation caused by thermal expansion, and further improve positioning accuracy.

[0033] As a preferred embodiment, the positioning posts 3 include three positioning posts: a first positioning post, a second positioning post, and a third positioning post. Six corresponding positioning post through holes 81 are provided. The first positioning post is located on the left front side of punch 4 and punch 5, the second positioning post is located on the right front side of punch 4 and punch 5, and the third positioning post is located on the rear side of punch 4 and punch 5. The three positioning posts 3 are arranged in a triangular pattern. This triangular positioning eliminates all degrees of freedom in the plane, prevents mold reversal, disperses the lateral force of upsetting, improves service life, and is suitable for high-speed continuous stamping.

[0034] As a preferred embodiment, the main mold base module includes a main mold pad 13 and a main mold base 8 disposed on the main mold pad 13. The main mold base 8 is provided with a main mold 9 that cooperates with the first punch 4 and the second punch 5 for stamping. The positioning pin through hole 81 is opened on the main mold base 8. The main mold base 8 can be replaced separately, while the main mold pad 13 is retained in the machine tool. When changing molds, it is only necessary to pull out the old main mold base, insert the new main mold base, and lock it in place.

[0035] As a preferred solution, the movable punch module and the main die base module, including the movable punch base plate 1, movable punch fixing plate 2, main die pad plate 13, and main die base 8, are all made of SKD-11 steel through wire cutting, and the material heat treatment hardness reaches HRC 58-60. Unlike the traditional 45# steel, this solution uses SKD-11 steel instead. The high-hardness die steel, combined with the "cut one, repair two" precision wire cutting, enables a micron-level sliding clearance between the positioning post 3 and the positioning post through hole 81, improving the wear resistance of the parts by more than 3 times. It can still maintain the initial accuracy under continuous high-speed stamping and reduce concentricity drift caused by wear.

[0036] Combination Figure 1-4 The working process of the quick mold changing device for the double-wire riveting machine of this utility model is as follows:

[0037] (1) Wire cutting: Copper wire mold 10 and silver wire mold 11 respectively feed copper wire and silver wire into their respective scissor holes; copper wire scissor 6 and silver wire scissor 7 move forward in sequence, copper wire scissor 6 cuts a section of copper wire and sends the cut copper wire to the center of the main mold through the cam mechanism, aligning with the center hole of the main mold; then silver wire scissor 7 cuts a section of silver wire and sends the cut silver wire to the center of the main mold through the servo feeding mechanism, aligning with the center of the cut copper wire.

[0038] (2) Positioning of the first punch: The entire movable punch module is moved horizontally to the pre-upsetting position. The movable punch module descends. Before the first punch 4 reaches the top of the main mold ejector pin 12, the three positioning pins 3 are inserted into the corresponding positioning pin through holes 81 to forcibly correct the concentricity of the movable punch and the main mold base.

[0039] (3) Pre-upsetting: Refer to Figure 3 The first punch presses down four times, and together with the main mold 9, it completes the pre-upsetting welding to form a silver-copper composite prototype. Then, the first punch returns four times, and the positioning column exits simultaneously.

[0040] (4) Second punch positioning: The movable punch die continues to move laterally until it reaches the final upsetting position. The movable punch die descends. Before the second punch 5 reaches above the main mold ejector pin 12, the positioning pin 3 is inserted into another set of positioning pin through holes 81 to ensure that the second punch 5 coincides with the center of the main mold.

[0041] (5) Final upsetting: Refer to Figure 4 The final upsetting is completed by pressing down 5 times, so that the head size, silver layer thickness and foot diameter meet the finished product requirements in one go;

[0042] (6) Demolding and part removal: Refer to Figure 2 The second stroke and the fifth return stroke cause the ejector pin in the mold cavity to push the finished product out of the mold cavity; the main mold ejector pin 12 moves upward and pushes the rivet out of the center hole of the main mold and into the finished product slide, completing one cycle;

[0043] (7) Cyclic Reset: Each component returns to its initial position, cuts off a new section of copper and silver wire, and enters the next cycle. During the operation, the positioning pin always enters the pin hole before the punch, ensuring that each mold is formed under the same reference, realizing zero adjustment, rapid mold change and high-precision continuous production.

[0044] The technical solution provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A quick mold-changing device for a double-wire riveting machine, characterized in that, include: The main mold base module is provided with an axially through main mold center hole and a main mold ejector pin that can slide axially in the main mold center hole; The copper wire mold and the silver wire mold are respectively located on one side of the main mold ejector pin, and are used to feed copper wire and silver wire respectively; The copper wire cutter and the silver wire cutter are respectively located on one side of the main mold base module, and are used to cut the copper wire and the silver wire respectively and send them to the center hole of the main mold. The movable punching module is positioned above the main mold base module. The movable punching module has a first punch and a second punch distributed on both sides below it. The first punch and the second punch move with the movable punching module and their movement paths cover the positions of the first punch and the second punch corresponding to the ejector pins of the main mold, respectively. At least two positioning pins are provided under the main mold base module, and the movable punch module is provided with at least four positioning pin through holes; the vertical distance from the positioning pin to the positioning pin through hole is less than the vertical distance from the first punch or the second punch to the main mold ejector pin; before the first punch moves to be directly opposite and engaged with the main mold ejector pin, the two positioning pins are respectively inserted into two of the positioning pin through holes; before the second punch moves to be directly opposite and engaged with the main mold ejector pin, the two positioning pins are respectively inserted into the other two positioning pin through holes.

2. The quick mold changing device for a double-wire riveting machine according to claim 1, characterized in that, The movable punch module includes a movable punch base plate and a movable punch fixing plate that is detachably installed under the movable punch base plate. The positioning post, the first punch, and the second punch are installed on the movable punch fixing plate.

3. The quick mold changing device for a double-wire riveting machine according to claim 2, characterized in that, A positioning pin and a positioning pin hole that matches and inserts into the movable punch base plate and the movable punch fixing plate are provided.

4. The quick mold changing device for a double-wire riveting machine according to claim 1, characterized in that, The surface of the positioning post is provided with several annular grooves.

5. The quick mold changing device for a double-wire riveting machine according to claim 1, characterized in that, The positioning post includes a first positioning post, a second positioning post, and a third positioning post. The first positioning post is located on the left front side of the first and second punches, the second positioning post is located on the right front side of the first and second punches, and the third positioning post is located on the rear side of the first and second punches.

6. The quick mold changing device for a double-wire riveting machine according to claim 1, characterized in that, The main mold base module includes a main mold pad and a main mold base disposed on the main mold pad. The main mold base is provided with a main mold that cooperates with the first and second punches for stamping. The positioning pin through hole is opened on the main mold base.

7. The quick mold changing device for a double-wire riveting machine according to claim 1, characterized in that, The movable punching die assembly and the main die base assembly are cut from SKD-11 steel.

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