Pin needle for making automobile connector by insert molding and processing technology thereof

Abstract

The application discloses a kind of PIN needle for insert molding manufacturing automobile connector and its processing technology, including PIN needle body, the end of PIN needle body is equipped with PIN needle head, PIN needle head and PIN needle body form contact area;Clamping portion, clamping portion is equipped in the other end of PIN needle body;And welding portion, welding portion is connected to clamping portion by link part.The PIN needle body, clamping portion and welding portion of the present application are set as integrally formed structure, completely eliminate the risk of loosening due to interference fit or welding in traditional split design, ensure the structural integrity and connection reliability of PIN needle in insert molding and subsequent automobile use process.

Description

Technical Field

[0001] This invention relates to a PIN pin for insert molding of automotive connectors and its processing technology. Background Technology

[0002] PIN pins (also known as connector pins or terminal pins) are metal components in connectors used for electrical conductivity and signal transmission.

[0003] The performance of the pins directly determines the electrical reliability, mechanical life, and environmental adaptability of the connector. Traditional pins are mostly made of tungsten carbide or copper alloy, formed by machining or powder metallurgy, and then surface treated. In the field of automotive connectors, especially when insert molding is involved, the pins need to be pre-placed in an injection mold and integrally injection molded with the plastic shell. This places extremely high demands on the dimensional accuracy, positioning stability, and bonding strength of the pins with the plastic.

[0004] Currently, existing PIN pins typically employ a split design, where the contact portion, snap-fit ​​portion, and soldering portion are processed separately and then assembled into a single unit using methods such as interference fit, riveting, or laser welding. However, this split structure has the following significant drawbacks:

[0005] (1) Poor connection reliability: The split structure relies on mechanical cooperation or welding connection. In the harsh environment of high frequency vibration and drastic temperature fluctuation (-40℃~150℃) in the engine compartment of the car, the connection is prone to fretting wear, stress relaxation or even loosening, resulting in increased contact resistance or signal interruption, which seriously affects driving safety.

[0006] (2) Difficulty in positioning inserts: Split pins are difficult to position precisely and stably in the axial and radial direction in injection molds. The impact of high-speed and high-pressure plastic melt during injection molding can easily cause the pins to shift, bend or "bent out of shape", resulting in uneven coating, out-of-tolerance exposed dimensions, and high scrap rate.

[0007] (3) Insufficient sealing and seepage prevention performance: There are micro gaps at the joints of the split structure, which are difficult to completely fill during injection molding. Furthermore, during use, corrosive media such as moisture and salt spray can easily seep into the connector along the joints, leading to a decrease in insulation resistance or electrochemical corrosion.

[0008] (4) Complex processing and assembly procedures: Separate parts need to be machined, stamped, heat treated, electroplated and other processes, and then assembled manually or automatically. There are many steps, large cumulative tolerances, low production efficiency and high cost, which makes it difficult to meet the large-scale and high consistency production needs of the automotive industry.

[0009] (5) Limited electroplating process: Each component of the split structure needs to be electroplated individually or electroplated as a whole after assembly. The former increases the number of processes, while the latter results in uneven plating due to the potential difference between different materials (such as hard alloy and copper alloy), which affects contact resistance and corrosion resistance.

[0010] To address the aforementioned issues, while some existing technologies attempt to employ one-piece turning, limitations in tool accessibility and material removal rate make it difficult to machine slender pins with complex slots, limiting steps, and irregularly shaped weld contours. Furthermore, residual stress generated during turning can easily lead to product deformation. In addition, existing processes lack systematic parameter optimization for key dimensions such as the total length of the pin, the width of each slot, and the arc groove, resulting in insufficient product consistency and mold adaptability. Summary of the Invention

[0011] The purpose of this invention is to provide a technical solution for the manufacturing of PIN pins for automotive connectors and their processing technology, addressing the shortcomings of existing technologies. By setting the PIN pin body, snap-fit ​​part, and soldering part as an integral molding structure, the risk of loosening due to interference fit or soldering in traditional split designs is completely eliminated. This ensures the structural integrity and connection reliability of the PIN pin during insert molding and subsequent automotive use, making it particularly suitable for harsh automotive environments with vibration and temperature changes, significantly improving connection reliability and structural stability.

[0012] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0013] A PIN pin for insert molding of automotive connectors, characterized in that: it includes...

[0014] The PIN needle body has a PIN needle tip at its end, and the PIN needle tip and the PIN needle body form a contact area.

[0015] A snap-fit ​​part is located at the other end of the PIN pin body;

[0016] And the welding part, which is connected to the snap-fit ​​part through the connecting part.

[0017] The pin provides clear functional zones, ensuring that it can simultaneously meet multiple needs such as contact with mating terminals (contact area), precise positioning in insert molding die (clamping part), and connection with cables or circuit boards (soldering part), laying the foundation for the overall functionality of the product.

[0018] Furthermore, the distance between the end face of the PIN pin and the end face of the soldering part is L1, 80mm≤L1≤85mm, which ensures that the PIN pin can adapt to the size requirements of specific automotive connector housings and insert molding dies, thus guaranteeing installation compatibility.

[0019] Furthermore, the distance between the end face of the PIN pin body and the snap-fit ​​part is L2, 25mm≤L2≤27mm, which ensures that the PIN pin and the mating terminal have sufficient contact area, thereby ensuring stable and low-resistance electrical contact performance.

[0020] Furthermore, the snap-fit ​​part includes a first limiting part, a second limiting part, a blocking part, and a fixing part. The first limiting part is close to the PIN needle tip, and the second limiting part and the blocking part are located between the fixing part and the first limiting part. By setting multiple limiting parts and blocking parts, multiple and precise axial and radial positioning of the PIN needle is achieved during the insert molding process, effectively preventing the PIN needle from shifting or deviating under injection pressure.

[0021] Furthermore, a first slot is provided between the first limiting part and the second limiting part. The width of the first slot is L3, 3.5mm≤L3≤4mm, which enables it to precisely cooperate with the positioning mechanism in the mold, providing reliable axial positioning and preventing the PIN pin from being punched out or pushed back during injection molding.

[0022] Furthermore, a second groove is provided between the second limiting part and the blocking part. The width of the second groove is L4, 3.5mm≤L4≤4mm, which enhances the bonding force between the PIN pin and the molded plastic and can effectively prevent liquid from seeping into the connector along the surface of the PIN pin.

[0023] Furthermore, a third slot is provided between the blocking part and the fixing part. The width of the third slot is L5, and 2.2mm≤L5≤2.5mm. This slot forms an interlocking structure with the injection-molded plastic, which plays an anchoring role and greatly enhances the holding force of the PIN pin in the connector, effectively preventing it from being pulled out or rotated due to external force.

[0024] Furthermore, the end of the PIN pin is provided with a positioning hole, and an arc-shaped groove is provided between the PIN pin and the PIN pin body. The positioning hole provides convenience for the suspension of the subsequent electroplating process, and also serves as a positioning reference for identifying and grasping products in the automated production line; the arc-shaped groove serves as a stress relief structure, which can effectively disperse the bending stress on the PIN pin during the insertion and removal process and prevent its root from breaking.

[0025] Furthermore, the PIN needle body, the snap-fit ​​part, and the soldering part are integrated into a single molded structure. The material used is copper, which ensures excellent electrical and thermal conductivity and fundamentally eliminates the connection strength and loosening risk of separate structures, significantly improving the electrical connection reliability and service life of the product.

[0026] A processing method for PIN pins in automotive connectors as described above, characterized by comprising the following steps:

[0027] S1, Cutting Material

[0028] a. Place the profile into the positioning fixture of the cutting machine, adjust the position of the profile, send it to the feeding clamp, start the cylinder, motor and water pump of the cutting machine in sequence, and confirm the cutting width. Press the start button to cut automatically. Put the material head cut off the first time into the scrap box, measure the product cut off the second time, until the inspection is qualified, and control the feed rate to 400-600mm.

[0029] b. During the unloading process, promptly sort out the products that flow down, blow off the surface saponification liquid with an air gun, check the appearance, and neatly place them into the transfer box to be transported to the next work station.

[0030] S2, Rough Car

[0031] a. Control the hydraulic pressure of the lathe between 2.5 and 4.5 MPa, and control the concentration of the saponification solution between 4 and 6%;

[0032] b. After cutting the product, place the welded part and the connecting part into the copper sleeve, then put it into the fixture, push the product to the bottom and position it, then clamp the workpiece, press the start switch, and the lathe will automatically perform rough turning on the contact area and the snap-fit ​​part.

[0033] c. Remove the machined product and place it neatly in the turnover box. Use an air gun to clean the copper slag on the fixture and cutting tools, and check each tool.

[0034] d. After placing the contact area and snap-fit ​​part of the machined product into the copper sleeve, put it into the fixture, push the product to the bottom for positioning, clamp the workpiece, press the start switch, and the lathe will automatically perform rough turning on the welded part and the connecting part.

[0035] e. Remove the machined product and place it neatly in the turnover box. Use an air gun to clean the copper slag on the fixture and cutting tools, and check each tool.

[0036] S3, Extrusion Molding

[0037] a. Clean the table and mold on the punch press. Place the product completed in step S2 into the die positioning slot, with the end face aligned with the mold positioning surface. Press the button, and the punch press will press down to complete the punching and trimming, forming the required welding and connection parts. After the hydraulic press of the punch press has fully returned to its original position, remove the product from the lower mold and place it neatly in the turnover box.

[0038] b. Clean the waste material attached to the upper mold and clean the lower mold with an air gun. There should be no copper dust or foreign matter in the first and second mold cavities.

[0039] S4, precision machining

[0040] a. First, place the contact area of ​​the extruded product into the copper sleeve, clamp and fix it with a fixture, and expose the snap-fit ​​and welded parts. Control the hydraulic pressure of the lathe at 2.5-4.5 MPa and the concentration of the saponification liquid at 4-6%. Perform precision turning on the lathe to form the fixing part, the third slot, the blocking part, the second slot, the second limiting part, the first slot and the first limiting part in sequence. During precision turning, the lathe uses an external turning cutter and an external grooving cutter. The speed of the external turning cutter is 1800 r / min and the feed rate is 0.08-0.1 mm / r. The speed of the external grooving cutter is 1200 r / min and the feed rate is 0.03-0.1 mm / r.

[0041] b. Then, place the welded part of the processed product into a copper sleeve, exposing the contact area to the outside. Control the hydraulic pressure of the lathe at 2.5-4.5 MPa and the concentration of the saponification solution at 4-6%. Perform precision turning on the lathe to form the PIN needle body and PIN needle head in sequence. Drill an arc groove between the PIN needle head and the PIN needle body, and then drill a positioning hole at the end of the PIN needle head. During precision turning, the lathe uses an external turning cutter, a diamond external turning cutter, a drill bit, and a chamfering cutter. The external turning cutter has a rotation speed of 1600 r / min and a feed rate of 0.1-0.15 mm / r. The diamond external turning cutter has a rotation speed of 1800 r / min and a feed rate of 0.03-0.06 mm / r. The drill bit has a rotation speed of 1800 r / min and a feed rate of 0.03-0.1 mm / r. The chamfering cutter has a rotation speed of 2000 r / min and a feed rate of 0.1-0.2 mm / r.

[0042] d. Finally, use an air gun to clean the copper slag off the cutting tools and check whether each tool is damaged;

[0043] S5, Drilling of fixed holes

[0044] After precision machining, place the product into a CNC milling and positioning fixture. Control the liquid source pressure at 2.5-4.5 MPa and the concentration of the saponification liquid at 4-6%. Press the start button and drill a fixing hole on the fixing part using a forming drill. The forming drill speed is 1500 r / min and the feed rate is 50-100 mm / r. After drilling, remove the product and place it in a turnover box. Clean the copper powder with an air gun.

[0045] S6, Electroplated Hard Silver

[0046] After drilling, the product is deburred by a polishing wheel. After processing, it is placed in an electroplating tank for silver plating by passing a suspension rope through a fixing hole.

[0047] This processing technology forms a synergistic overall process solution by precisely controlling the process parameters in each process step. It not only realizes the integrated and efficient production of products, but more importantly, the comprehensive control of these parameters ensures that the final product can meet the aforementioned dimensional accuracy and surface quality requirements, thereby guaranteeing the overall performance of the PIN pin.

[0048] Furthermore, the punch press in step S3 includes a base plate, a top plate, a lower die, and an upper die. The lower die is connected to the base plate via a base, and the upper die is connected to the top plate. The top plate is connected above the base plate via a hydraulic cylinder. The top surface of the lower die is provided with a first die cavity and a second die cavity that are interconnected. The first die cavity is provided with a pressing component, a first mounting plate, and an inclined block. The first mounting plate is detachably connected to the first die cavity. A lower pressing block is fixedly connected between the two first mounting blocks. A lower die positioning groove is provided on the top surface of the lower pressing block. The inclined block is located between the second die cavity and the lower pressing block. A second mounting plate is provided on the bottom surface of the upper die. An upper pressing block and a trapezoidal block are provided on the second mounting plate. The upper pressing block is provided with an upper die positioning groove that matches the lower die positioning groove. The trapezoidal block is detachably connected to the second mounting plate via a third mounting plate. The trapezoidal block and the upper pressing block cooperate to form an inclined groove. By setting up mutually cooperating upper and lower dies, as well as positioning grooves, inclined blocks, and trapezoidal blocks located within the dies, the cutting and pre-forming of the product can be completed simultaneously in one stamping action, ensuring the accuracy and consistency of the shape of the welded and connecting parts, and improving the durability and production efficiency of the dies.

[0049] Furthermore, the clamping assembly includes a U-shaped block, a locking block, a push rod, and a clamping block. The clamping block is connected to the locking block via the push rod, the locking block is detachably connected to the U-shaped block, and the U-shaped block is detachably connected to the side of the lower die. Through the design of the push rod and the clamping block, this assembly can firmly fix the product in the positioning groove of the lower die from the side during stamping, effectively preventing displacement of the product under tremendous impact force and significantly improving the yield rate of the stamping process.

[0050] Furthermore, a baffle is provided on the top surface of the lower mold on the other side of the second mold cavity. The baffle on the lower mold serves to limit and block movement. On the one hand, it can be used as a lateral positioning reference when the product is placed in, and on the other hand, it can prevent stamping waste from splashing, thereby improving operational safety and the cleanliness of the mold area.

[0051] The present invention, by adopting the above-described technical solution, has the following beneficial effects:

[0052] 1. This invention completely eliminates the risk of loosening caused by interference fit or welding in traditional split designs by making the PIN body, snap-fit ​​part and welding part into an integrated structure. It ensures the structural integrity and connection reliability of the PIN during insert molding and subsequent automotive use. It is especially suitable for harsh automotive environments with vibration and temperature changes, and the connection reliability and structural stability are significantly improved.

[0053] 2. This invention adopts an integrated structure and its processing technology, eliminating the cumbersome steps of processing and assembling separate parts. Through a streamlined process of "material cutting - rough turning - extrusion molding - precision turning - drilling - electroplating", especially by using cold extrusion molding technology to directly form the complex contours of welded and connecting parts, near-net-shape forming is achieved, significantly reducing material waste, processing time, and labor costs, improving production efficiency, simplifying processing procedures, and reducing costs.

[0054] 3. This invention precisely parameters and limits the total length of the PIN pin, the distance between the body and the locking part, and the width of the first, second, and third locking slots. Combined with the control of specific process parameters such as spindle speed and feed rate in the roughing and finishing processes, this invention ensures a high degree of consistency in product dimensions during mass production, meets the stringent requirements of automotive connectors for PIN pin precision, and ensures smooth use in automated insert molding equipment with high dimensional accuracy and product consistency.

[0055] 4. This invention uses copper as the base material and combines it with a final hard silver electroplating process, giving the PIN pins extremely low contact resistance and excellent conductivity, ensuring efficient signal and current transmission. Simultaneously, the hard silver plating gives the PIN pins good wear resistance and corrosion resistance, effectively resisting the high temperatures, humidity, and chemical corrosion commonly found in automotive engine compartments, significantly extending the product's service life, and exhibiting excellent conductivity and corrosion resistance. Attached Figure Description

[0056] The present invention will be further described below with reference to the accompanying drawings:

[0057] Figure 1 This is an illustration of a PIN pin used in the manufacturing of automotive connectors for insert molding, and the effect of the PIN pin in the processing technology thereof.

[0058] Figure 2 for Figure 1 Top view;

[0059] Figure 3 for Figure 2 A cross-sectional view along the AA direction;

[0060] Figure 4 This is a schematic diagram illustrating the connection between the PIN tip and the PIN body in this invention;

[0061] Figure 5 This is a flowchart illustrating the manufacturing process of the PIN pins in this invention.

[0062] Figure 6 This is a schematic diagram of the punch press in this invention;

[0063] Figure 7 This is a schematic diagram of the connection of the lower mold in this invention;

[0064] Figure 8 for Figure 6 A schematic diagram of the structure in the B direction.

[0065] In the image: 1-PIN pin body;

[0066] 2-Snap-fit ​​part; 201-First limiting part; 202-Second limiting part; 203-Blocking part; 204-Fixing part; 205-First slot; 206-Second slot; 207-Third slot;

[0067] 3-Welding part; 4-Fixing hole;

[0068] 5-PIN pin; 501-Positioning hole; 502-Arc groove;

[0069] 6-Connecting part; 7-Base plate; 8-Top plate; 9-Hydraulic cylinder; 10-Base; 11-Lower mold; 12-Upper mold; 13-Clamping assembly; 14-Lower punch positioning groove; 15-Baffle; 16-First mold cavity; 17-Second mold cavity; 18-First mounting plate; 19-U-shaped block; 20-Clamping block; 21-Push rod; 22-Clamping block; 23-Second mounting plate; 24-Upper pressure block; 25-Upper punch positioning groove; 26-Trapezoidal block; 27-Third mounting plate; 28-Inclined groove; 29-Inclined block. Detailed Implementation

[0070] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0071] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0072] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0073] like Figures 1 to 4 As shown, this invention provides a PIN pin for insert molding of automotive connectors, comprising a PIN pin body 1, a snap-fit ​​portion 2, and a soldering portion 3.

[0074] The end of the PIN needle body 1 is provided with a PIN needle tip 5, and the PIN needle tip 5 and the PIN needle body 1 form a contact area.

[0075] The distance between the end face of the PIN pin 5 and the end face of the soldering part 3 is L1, 80mm≤L1≤85mm, which ensures that the PIN pin can adapt to the size requirements of the specific model of automotive connector housing and insert molding die, and guarantees the compatibility of installation.

[0076] The snap-fit ​​part 2 is located at the other end of the PIN pin body 1.

[0077] The distance between the end face of the PIN pin body 1 and the snap-fit ​​part 2 is L2, 25mm≤L2≤27mm, which ensures that the PIN pin and the mating terminal have sufficient contact area, thereby ensuring stable and low-resistance electrical contact performance.

[0078] The snap-fit ​​part 2 includes a first limiting part 201, a second limiting part 202, a blocking part 203, and a fixing part 204. The first limiting part 201 is close to the PIN needle 5, and the second limiting part 202 and the blocking part 203 are located between the fixing part 204 and the first limiting part 201. By setting multiple limiting parts and blocking parts 203, multiple and precise axial and radial positioning of the PIN needle is achieved during the insert molding process, effectively preventing the PIN needle from shifting or deviating under injection pressure.

[0079] A first slot 205 is provided between the first limiting part 201 and the second limiting part 202. The width of the first slot 205 is L3, 3.5mm≤L3≤4mm, which enables it to precisely cooperate with the positioning mechanism in the mold, providing reliable axial positioning and preventing the PIN pin from being punched out or pushed back during injection molding.

[0080] A second slot 206 is provided between the second limiting part 202 and the blocking part 203. The width of the second slot 206 is L4, 3.5mm≤L4≤4mm, which enhances the bonding force between the PIN pin and the molded plastic and can effectively prevent liquid from seeping into the connector along the surface of the PIN pin.

[0081] A third slot 207 is provided between the blocking part 203 and the fixing part 204. The width of the third slot 207 is L5, 2.2mm≤L5≤2.5mm. The slot and the injection-molded plastic form an interlocking structure, which plays an anchoring role and greatly enhances the holding force of the PIN pin in the connector, effectively preventing it from being pulled out or rotated due to external force.

[0082] The welding part 3 is connected to the snap-fit ​​part 2 via the connecting part 6.

[0083] The end of the PIN needle 5 is provided with a positioning hole 501, and an arc groove 502 is provided between the PIN needle 5 and the PIN needle body 1. The positioning hole 501 provides convenience for the suspension of the subsequent electroplating process, and also serves as a positioning reference for identifying and grasping products in the automated production line. The arc groove 502 serves as a stress relief structure, which can effectively disperse the bending stress on the PIN needle 5 during the insertion and removal process and prevent its root from breaking.

[0084] The PIN needle 5 body, the snap-fit ​​part 2, and the soldering part 3 are integrally molded structures made of copper. The use of copper as an integral material ensures excellent electrical and thermal conductivity, and fundamentally eliminates the connection strength and loosening risk of separate structures, significantly improving the electrical connection reliability and service life of the product.

[0085] The PIN pin provides clear functional partitions, ensuring that it can simultaneously meet multiple needs such as contact with mating terminals (contact area), precise positioning in insert molding die (clamping part 2), and connection with cables or circuit boards (soldering part 3), laying the foundation for the overall functionality of the product.

[0086] The above dimensional parameters have been verified through finite element analysis and multiple trial moldings. They can ensure sufficient contact pressure while preventing plastic overflow from clogging the slots during injection molding and ensuring a precise fit between each slot and the mold positioning components.

[0087] A processing method for PIN pins used in insert molding of automotive connectors, as described above, includes the following steps:

[0088] S1, Cutting Material

[0089] a. Place the profile into the positioning fixture of the cutting machine, adjust the position of the profile, send it to the feeding clamp, start the cylinder, motor and water pump of the cutting machine in sequence, and confirm the cutting width. Press the start button to cut automatically. Put the material head cut off the first time into the scrap box, measure the product cut off the second time, until the inspection is qualified, and control the feed rate to 400-600mm.

[0090] b. During the unloading process, promptly sort out the products that flow down, blow off the surface saponification liquid with an air gun, check the appearance, and neatly place them into the transfer box to be transported to the next work station.

[0091] S2, Rough Car

[0092] a. Control the hydraulic pressure of the lathe between 2.5 and 4.5 MPa, and control the concentration of the saponification solution between 4 and 6%;

[0093] b. After the cut product is placed into the copper sleeve, the product is placed into the fixture, the product is pushed to the bottom and positioned, the workpiece is clamped, the start switch is pressed, and the lathe automatically performs rough turning on the contact area and the snap-fit ​​part 2.

[0094] c. Remove the machined product and place it neatly in the turnover box. Use an air gun to clean the copper slag on the fixture and cutting tools, and check each tool.

[0095] d. After placing the contact area of ​​the machined product and the snap-fit ​​part 2 into the copper sleeve, put it into the fixture, push the product to the bottom for positioning, clamp the workpiece, press the start switch, and the lathe will automatically perform rough turning on the welding part 3 and the connecting part 6.

[0096] e. Remove the machined product and place it neatly in the turnover box. Use an air gun to clean the copper slag on the fixture and cutting tools, and check each tool.

[0097] S3, Extrusion Molding

[0098] a. Clean the table and mold on the punch press, place the product completed in step S2 into the die positioning groove, with the end face aligned with the mold positioning surface, press the button, and the punch press will press down to complete the punching and trimming, forming the required welding part 3 and connecting part 6. After the hydraulic press of the punch press has fully returned to its original position, take the product out of the lower mold 11 and place it neatly in the turnover box.

[0099] b. Clean the waste material attached to the upper mold 12 and clean the lower mold 11 with an air gun. There are no copper dust or foreign objects in the first mold cavity 16 and the second mold cavity 17.

[0100] The punch press includes a base plate 7, a top plate 8, a lower die 11, and an upper die 12. The lower die 11 is connected to the base plate 7 via a base 10, and the upper die 12 is connected to the top plate 8. The top plate 8 is connected above the base plate 7 via a hydraulic cylinder 9. The top surface of the lower die 11 is provided with a first die cavity 16 and a second die cavity 17 that are interconnected. The first die cavity 16 is provided with a clamping assembly 13, a first mounting plate 18, and an inclined block 29. The first mounting plate 18 is detachably connected to the first die cavity 16, and the two first mounting blocks are fixedly connected. The upper mold 12 has a lower pressure block with a lower die positioning groove 14 on its top surface. An inclined block 29 is located between the second mold cavity 17 and the lower pressure block. A second mounting plate 23 is provided on the bottom surface of the upper mold 12. An upper pressure block 24 and a trapezoidal block 26 are provided on the second mounting plate 23. The upper pressure block 24 has an upper die positioning groove 25 that matches the lower die positioning groove 14. The trapezoidal block 26 is detachably connected to the second mounting plate 23 via a third mounting plate 27. The trapezoidal block 26 and the upper pressure block 24 cooperate to form an inclined groove 28. By setting up the mutually cooperating upper mold 12 and lower mold 11, as well as the positioning groove, inclined block 29, and trapezoidal block 26 located in the mold, the trimming and pre-forming of the product can be completed simultaneously in one stamping action. This ensures the accuracy and consistency of the shape of the welded part 3 and the connecting part 6, and improves the durability of the mold and the production efficiency.

[0101] The clamping assembly 13 includes a U-shaped block 19, a locking block 20, a push rod 21, and a clamping block 22. The clamping block 22 is connected to the locking block 20 via the push rod 21. The locking block 20 is detachably connected to the U-shaped block 19, and the U-shaped block 19 is detachably connected to the side of the lower mold 11. Through the design of the push rod 21 and the clamping block 22, this assembly can firmly fix the product in the positioning groove of the lower mold 11 from the side during stamping, effectively preventing displacement of the product under tremendous impact force and significantly improving the yield rate of the stamping process.

[0102] A baffle 15 is provided on the top surface of the lower mold 11 on the other side of the second mold cavity 17. The baffle 15 on the lower mold 11 serves to limit and block, acting as a lateral positioning reference when the product is placed in, and preventing stamping waste from splashing, thus improving operational safety and the cleanliness of the mold area.

[0103] S4, precision machining

[0104] a. First, place the contact area of ​​the extruded product into the copper sleeve, clamp and fix it with a fixture, and expose the snap-fit ​​part 2 and the welding part 3. Control the hydraulic pressure of the lathe at 2.5-4.5 MPa and the concentration of the saponification liquid at 4-6%. Perform precision turning on the lathe to form the fixing part 204, the third slot 207, the blocking part 203, the second slot 206, the second limiting part 202, the first slot 205 and the first limiting part 201 in sequence. During precision turning, the lathe uses an external turning cutter and an external grooving cutter. The speed of the external turning cutter is 1800 r / min and the feed rate is 0.08-0.1 mm / r. The speed of the external grooving cutter is 1200 r / min and the feed rate is 0.03-0.1 mm / r.

[0105] b. Then, place the welded part 3 of the processed product into the copper sleeve, exposing the contact area to the outside. Control the hydraulic pressure of the lathe at 2.5-4.5 MPa and the concentration of the saponification solution at 4-6%. Perform finish turning on the lathe to form the PIN needle body 1 and the PIN needle head 5 in sequence. Drill an arc-shaped groove 502 between the PIN needle head 5 and the PIN needle body 1, and then drill a positioning hole 501 along the end of the PIN needle head 5. During finish turning, the lathe adopts an external... Circular cutters, diamond external circular cutters, drill bits, and chamfering cutters are available. The external circular cutter has a rotational speed of 1600 r / min and a feed rate of 0.1–0.15 mm / r. The diamond external circular cutter has a rotational speed of 1800 r / min and a feed rate of 0.03–0.06 mm / r. The drill bit has a rotational speed of 1800 r / min and a feed rate of 0.03–0.1 mm / r. The chamfering cutter has a rotational speed of 2000 r / min and a feed rate of 0.1–0.2 mm / r.

[0106] d. Finally, use an air gun to clean the copper slag off the cutting tools and check whether each tool is damaged;

[0107] S5, Drill hole 4

[0108] After precision machining, place the product into a CNC milling and positioning fixture. Control the liquid source pressure at 2.5-4.5 MPa and the concentration of the saponification liquid at 4-6%. Press the start button to drill the fixing hole 4 on the fixing part 204 using a forming drill. The rotation speed of the forming drill is 1500 r / min and the feed rate is 50-100 mm / r. After drilling, remove the product and place it in a turnover box. Use an air gun to clean the copper powder.

[0109] S6, Electroplated Hard Silver

[0110] After drilling, the product is deburred by a polishing wheel. After processing, it is placed in an electroplating tank for silver plating after passing through the fixing hole 4 with a suspension rope.

[0111] This processing technology forms a synergistic overall process solution by precisely controlling the process parameters in each process step. It not only realizes the integrated and efficient production of products, but more importantly, the comprehensive control of these parameters ensures that the final product can meet the aforementioned dimensional accuracy and surface quality requirements, thereby guaranteeing the overall performance of the PIN pin.

[0112] The test results of PIN pins mass-produced using the processing technology of this invention are as follows:

[0113] 1. Appearance: The surface must be smooth and free from cracks, bubbles, grooves, burrs, scratches, discoloration, blemishes, oil stains and other surface defects.

[0114] 2. Electroplating: 8-12µm of hard silver is plated on the nickel layer in the connection area, 6-10µm of hard silver is plated on the nickel layer in the assembly area, and at least 1µm of hard silver is plated on the nickel layer in other areas. The hard silver requirements are: silver content 97%-98%, hardness ≥130HV, and passivation treatment is performed.

[0115] 3. Electrical conductivity (IACS): 97.5%;

[0116] 4. Hardness (HV): ≥130HV;

[0117] 5. Surface tension (N / m): >35;

[0118] 6. Dimensions (mm): Φ8±0.05 Meets requirements

[0119] Φ11±0.05 meets the requirements.

[0120] Φ9.2±0.05 meets the requirements.

[0121] Φ10±0.05 meets the requirements.

[0122] Φ4±0.1 meets the requirements

[0123] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to achieve substantially the same technical effect are all covered within the protection scope of the present invention.

Claims

1. A PIN pin for insert molding of automotive connectors, characterized in that: include The PIN needle body has a PIN needle tip at its end, and the PIN needle tip and the PIN needle body form a contact area. A snap-fit ​​portion is provided at the other end of the PIN pin body; And a welding part, which is connected to the snap-fit ​​part via a connecting part.

2. A PIN pin for insert molding of automotive connectors according to claim 1, characterized in that: The distance between the end face of the PIN needle and the end face of the solder joint is L1, where 80mm≤L1≤85mm.

3. A PIN pin for insert molding of automotive connectors according to claim 1, characterized in that: The distance between the end face of the PIN pin body and the snap-fit ​​part is L2, where 25mm≤L2≤27mm.

4. A PIN pin for insert molding of automotive connectors according to claim 1, characterized in that: The latching portion includes a first limiting portion, a second limiting portion, a blocking portion, and a fixing portion. The first limiting portion is close to the PIN needle, and the second limiting portion and the blocking portion are located between the fixing portion and the first limiting portion.

5. A PIN pin for insert molding of automotive connectors according to claim 4, characterized in that: A first slot is provided between the first limiting part and the second limiting part, and the width of the first slot is L3, 3.5mm≤L3≤4mm.

6. A PIN pin for insert molding of automotive connectors according to claim 4, characterized in that: A second slot is provided between the second limiting part and the blocking part, and the width of the second slot is L4, 3.5mm≤L4≤4mm.

7. A PIN pin for insert molding of automotive connectors according to claim 4, characterized in that: A third slot is provided between the blocking part and the fixing part, and the width of the third slot is L5, 2.2mm≤L5≤2.5mm.

8. A PIN pin for insert molding of automotive connectors according to claim 1, characterized in that: The end of the PIN needle is provided with a positioning hole, and an arc-shaped groove is provided between the PIN needle and the PIN needle body.

9. A PIN pin for insert molding of automotive connectors according to claim 1, characterized in that: The PIN needle body, the snap-fit ​​part, and the soldering part are integrally formed and are made of copper.

10. A processing method for PIN pins used in insert molding of automotive connectors as described in any one of claims 1 to 9, characterized in that... Includes the following steps: S1, Cutting Material a. Place the profile into the positioning fixture of the cutting machine, adjust the position of the profile, send it to the feeding clamp, start the cylinder, motor and water pump of the cutting machine in sequence, and confirm the cutting width. Press the start button to cut automatically. Put the material head cut off the first time into the scrap box, measure the product cut off the second time, until the inspection is qualified, and control the feed rate to 400-600mm. b. During the unloading process, promptly sort out the products that flow down, blow off the surface saponification liquid with an air gun, check the appearance, and neatly place them into the transfer box to be transported to the next work station. S2, Rough Car a. Control the hydraulic pressure of the lathe between 2.5 and 4.5 MPa, and control the concentration of the saponification solution between 4 and 6%; b. After cutting the product, place the welded part and the connecting part into the copper sleeve, then put it into the fixture, push the product to the bottom and position it, then clamp the workpiece, press the start switch, and the lathe will automatically perform rough turning on the contact area and the snap-fit ​​part. c. Remove the machined product and place it neatly in the turnover box. Use an air gun to clean the copper slag on the fixture and cutting tools, and check each tool. d. After placing the contact area and snap-fit ​​part of the machined product into the copper sleeve, put it into the fixture, push the product to the bottom for positioning, clamp the workpiece, press the start switch, and the lathe will automatically perform rough turning on the welded part and the connecting part. e. Remove the machined product and place it neatly in the turnover box. Use an air gun to clean the copper slag on the fixture and cutting tools, and check each tool. S3, Extrusion Molding a. Clean the table and mold on the punch press. Place the product completed in step S2 into the die positioning slot, with the end face aligned with the mold positioning surface. Press the button, and the punch press will press down to complete the punching and trimming, forming the required welding and connection parts. After the hydraulic press of the punch press has fully returned to its original position, remove the product from the lower mold and place it neatly in the turnover box. b. Clean the waste material adhering to the upper mold and clean the lower mold with an air gun. There should be no copper dust or foreign matter in the first and second mold cavities. S4, precision machining a. First, place the contact area of ​​the extruded product into the copper sleeve, clamp and fix it with a fixture, and expose the snap-fit ​​and welded parts. Control the hydraulic pressure of the lathe at 2.5-4.5 MPa and the concentration of the saponification liquid at 4-6%. Perform precision turning on the lathe to form the fixing part, the third slot, the blocking part, the second slot, the second limiting part, the first slot and the first limiting part in sequence. During precision turning, the lathe uses an external turning cutter and an external grooving cutter. The speed of the external turning cutter is 1800 r / min and the feed rate is 0.08-0.1 mm / r. The speed of the external grooving cutter is 1200 r / min and the feed rate is 0.03-0.1 mm / r. b. Then, place the welded part of the processed product into a copper sleeve, exposing the contact area to the outside. Control the hydraulic pressure of the lathe at 2.5-4.5 MPa and the concentration of the saponification solution at 4-6%. Perform precision turning on the lathe to form the PIN needle body and PIN needle head in sequence. Drill an arc groove between the PIN needle head and the PIN needle body, and then drill a positioning hole at the end of the PIN needle head. During precision turning, the lathe uses an external turning cutter, a diamond external turning cutter, a drill bit, and a chamfering cutter. The external turning cutter has a rotation speed of 1600 r / min and a feed rate of 0.1-0.15 mm / r. The diamond external turning cutter has a rotation speed of 1800 r / min and a feed rate of 0.03-0.06 mm / r. The drill bit has a rotation speed of 1800 r / min and a feed rate of 0.03-0.1 mm / r. The chamfering cutter has a rotation speed of 2000 r / min and a feed rate of 0.1-0.2 mm / r. d. Finally, use an air gun to clean the copper slag off the cutting tools and check whether each tool is damaged; S5, Drilling of fixed holes After precision machining, place the product into a CNC milling and positioning fixture. Control the liquid source pressure at 2.5-4.5 MPa and the concentration of the saponification liquid at 4-6%. Press the start button and drill a fixing hole on the fixing part using a forming drill. The forming drill speed is 1500 r / min and the feed rate is 50-100 mm / r. After drilling, remove the product and place it in a turnover box. Clean the copper powder with an air gun. S6, Electroplated Hard Silver After drilling, the product is deburred by a polishing wheel. After processing, it is placed in an electroplating tank for silver plating by passing a suspension rope through a fixing hole.

11. The processing technology for PIN pins in the manufacture of automotive connectors using insert molding according to claim 10, characterized in that: The punch press in step S3 includes a base plate, a top plate, a lower die, and an upper die. The lower die is connected to the base plate via a base, and the upper die is connected to the top plate. The top plate is connected above the base plate via a hydraulic cylinder. The top surface of the lower die has a first die cavity and a second die cavity that communicate with each other. The first die cavity has a pressing component, a first mounting plate, and an inclined block. The first mounting plate is detachably connected to the first die cavity. A lower pressing block is fixedly connected between the two first mounting blocks. The top surface of the lower pressing block has a lower die positioning groove. The inclined block is located between the second die cavity and the lower pressing block. The bottom surface of the upper die has a second mounting plate. The second mounting plate has an upper pressing block and a trapezoidal block. The upper pressing block has an upper die positioning groove that matches the lower die positioning groove. The trapezoidal block is detachably connected to the second mounting plate via a third mounting plate. The trapezoidal block and the upper pressing block cooperate to form an inclined groove.

12. The processing technology for PIN pins in the manufacture of automotive connectors using insert molding according to claim 11, characterized in that: The clamping assembly includes a U-shaped block, a locking block, a push rod, and a clamping block. The clamping block is connected to the locking block via the push rod. The locking block is detachably connected to the U-shaped block. The U-shaped block is detachably connected to the side of the lower mold.

13. The processing technology for PIN pins in the manufacture of automotive connectors using insert molding according to claim 11, characterized in that: A baffle is provided on the top surface of the lower mold on the other side of the second mold cavity.

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