Automobile connector terminal and manufacturing process thereof

Abstract

The invention discloses an automobile connector terminal and a manufacturing process thereof, and relates to the technical field of automobile terminal production, the automobile connector terminal comprises a terminal main body, a terminal injection molding surface is arranged in the middle of the terminal main body, and first etching grooves are formed in the top surface and the bottom surface of the terminal injection molding surface; the front face and the back face of the terminal injection molding face are each provided with a second etching groove, the outer wall of the terminal injection molding face of the terminal body is fixedly connected with an injection molding block, and the positions, corresponding to the first etching grooves of the terminal injection molding face, of the inner wall of the injection molding block are each provided with an injection molding large face. The tight combination between hardware and injection molding is increased, under the microscopic condition, the combination area of the terminal and the plastic is increased, the bending of the wave crests and the wave troughs is formed, the bumpiness of the air channel is increased, and the automobile connector can meet the sealing requirement under the power working environment of the new energy automobile.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive terminal production, and particularly relates to an automotive connector terminal and its manufacturing process. Background Art

[0002] A connector builds a communication bridge between blocked or isolated circuits in a circuit, enabling current to flow and the circuit to achieve its intended function. The forms and structures of connectors are ever-changing, and there are various forms of connectors depending on different application objects, frequencies, powers, application environments, etc. Especially in recent years with the rise of new energy vehicles, there are more and more special requirements for connectors.

[0003] In the prior art, automotive connectors generally use the smooth surface of the terminal for direct injection molding. In the power working environment of new energy vehicles, the automotive connector cannot meet the sealing requirements, affecting the electrical connection stability of new energy vehicles. Therefore, the present invention provides an automotive connector terminal and its manufacturing process. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] To achieve the above object, the present invention provides the following technical solutions: An automotive connector terminal includes a terminal body. A terminal injection molding surface is provided in the middle of the terminal body. First etching grooves are provided on both the top surface and the bottom surface of the terminal injection molding surface, and second etching grooves are provided on both the front surface and the back surface of the terminal injection molding surface. An injection molding block is fixedly connected to the outer wall of the terminal injection molding surface of the terminal body. Injection molding large surfaces are provided at positions corresponding to the first etching grooves on the inner wall of the injection molding block, and injection molding small surfaces are provided at positions corresponding to the second etching grooves.

[0006] A manufacturing process for an automotive connector terminal includes the following steps: S1. First, select a metal strip that meets the terminal manufacturing standards, perform electrolytic cleaning on it under the conditions of a current density of 3 - 5 A / dm² and a temperature of 40 - 60 °C, and then transport it to a stamping device. When the metal strip is fed into a mold that conforms to the terminal body, stamping is performed to stamp the metal strip into a primary terminal with a terminal bending shape. S2. For the primary terminal after stamping, the terminal needs to be sheared. After shearing, burr removal is required. After burr removal is completed, the terminal needs to be drilled to drill connection holes for automotive connection. After drilling, the terminal needs to be cleaned. After degreasing treatment, it is dried to ensure its appearance is clean, without burrs and oil stains. S3. Perform a film coating operation on the surface of the processed primary terminal. After the film coating operation, perform special treatment on the area to be injection-molded, that is, in the film coating area, perform a spray-type film coating, namely rough film coating, to ensure that the injection-molded area of the primary terminal has a film coating area in 40 - 60% of the area. When performing the spray-type film coating, at the same time, perform the film coating operation on the non-injection-molded area. The film coating for the non-film coating area is full coverage. After the film coating is completed, perform an etching operation at this time; S4. When performing the etching operation, first ensure that the etching solution is sprayed on the rough film coating area of the primary terminal. For the uncoated area of the injection-molded area, use the continuous spray method. When spraying, control the spray time of each side to be the same to ensure the same etching process; S5. After the etching is completed, perform a film removal operation. After the film removal is completed, obtain the etched terminal and perform the injection molding operation at this time; S6. When performing the injection molding, first determine the pressure and injection speed of the injection molding machine. By placing the etched terminal into the injection molding die, start the injection molding machine to inject the plastic material into the die, control the injection speed, and perform it slowly to prevent the injection speed from being too fast and damaging the etched structure on the terminal surface. At the same time, control the fluidity of the plastic material in the injection molding machine and increase it. After the increase, perform the injection molding at this time to ensure that the injected material can flow into the first etching groove and the second etching groove on the surface of the etched terminal. After the injection molding is completed, perform a curing treatment; S7. After the curing treatment is completed, perform a deburring operation to remove the burrs on the surface of the injection molding block, and then the finished product of the terminal body can be obtained.

[0007] Furthermore, the metal strip used is a copper alloy.

[0008] Furthermore, the etching solution used is FeCl 3 solution, and the mass concentration of the solution is 20% - 28%.

[0009] Furthermore, the film coating used is an epoxy resin-based ink, and the film removal operation uses DMAC for immersion treatment.

[0010] Furthermore, during the injection molding operation, the initial injection speed is as low as 30 - 50% of the rated value. After the etching groove has been blocked, the speed is increased to the rated value for injection molding. At the same time, according to the injection molding material, the temperature is appropriately increased to improve the fluidity of the injection molding material.

[0011] In the above technical solution, the technical effects and advantages provided by the present invention: 1. Through the treatment of hardware parts, the present invention enhances the tight combination between the hardware and the injection molding. Under microscopic conditions, it increases the bonding area between the terminals and the plastic, forms undulations of peaks and valleys, and increases the ruggedness of the air channels, enabling the automotive connector to still meet the sealing requirements under the power working environment of new energy vehicles.

[0012] 2. By adopting phased injection molding control, the present invention can greatly control the injection molding of the etching groove during injection molding, prevent melt jetting marks, air entrapment, and the erosion of the etching structure. At the same time, injecting at a rated rate can also increase the flow length, ensure full filling of the thin-walled area, and reduce shrinkage cavities.

[0013] 3. Through microscopic treatment by chemical etching, the present invention uses an etching structure to avoid sharp burrs and reduce the risk of high-voltage breakdown of terminals in new energy vehicles.

[0014] 4. Through material selection, etching microstructure design, phased injection molding control, and integration of the environmental protection process chain, the present invention achieves the comprehensive goals of high performance, low cost, and high reliability of the connector terminals, and is particularly suitable for harsh scenarios such as high-voltage connectors for new energy vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0016] Figure 1 is the overall structure schematic diagram of the present invention; Figure 2 is the overall structure decomposition schematic diagram of the present invention; Figure 3 is the cross-sectional structure schematic diagram of the injection molding block of the present invention; Figure 4 is the structure schematic diagram of the traditional terminal metal part of the present invention; Figure 5 is the overall structure schematic diagram of the traditional terminal of the present invention; Figure 6 is the structure schematic diagram of the etching groove of the present invention; Figure 7 is the schematic diagram after injection molding of the etching groove of the present invention.

[0017] DESCRIPTION OF THE REFERENCE NUMERALS: 1. Terminal body; 101. Terminal injection surface; 1011. First etching groove; 102. Second etching groove; 2. Injection molding block; 201. Large injection surface; 202. Small injection surface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0019] An embodiment of the present invention discloses an automotive connector terminal and its manufacturing process.

[0020] The present invention provides an automotive connector terminal as shown in Figure 1 - Figure 7 Figure 10, including a terminal body 1. A terminal injection surface 101 is provided in the middle of the terminal body 1. First etching grooves 1011 are provided on both the top surface and the bottom surface of the terminal injection surface 101. Second etching grooves 102 are provided on both the front surface and the back surface of the terminal injection surface 101. An injection block 2 is fixedly connected to the outer wall of the terminal injection surface 101 of the terminal body 1. Injection large surfaces 201 are provided at positions corresponding to the first etching grooves 1011 of the terminal injection surface 101 on the inner wall of the injection block 2. Injection small surfaces 202 are provided at positions corresponding to the second etching grooves 102 on the injection block 2.

[0021] An automotive connector terminal and its manufacturing process include the following: S1. First, select a metal strip that meets the terminal production standard, perform electrolytic cleaning on it under the conditions of a current density of 3 - 5 A / dm² and a temperature of 40 - 60 °C, and then transport it to a stamping device. When the metal strip is fed into a mold that conforms to the terminal body 1, stamping is performed to stamp the metal strip into a primary terminal with a terminal bending shape. S2. For the primary terminal after stamping, the terminal needs to be sheared. After shearing, burr removal is required. After burr removal is completed, at this time, the terminal needs to be drilled to drill a connection hole for automotive connection. After drilling is completed, the terminal needs to be cleaned. After degreasing treatment is completed, drying is performed to ensure its appearance is clean, without burrs and oil stains. S3. Perform a film covering operation on the surface of the processed primary terminal. After the film covering operation, special treatment is required for the area to be injection molded, that is, in the film covering area, a spray type film covering is performed, that is, rough film covering, to ensure that the injection molding area of the primary terminal has a film covering area in 40 - 60% of the area. When performing the spray type film covering, the non-injection molding area is also film covered at the same time. The film covering for the non-injection molding area is full coverage. After the film covering is completed, at this time, an etching operation is performed. Epoxy resin-based ink film covering is used to distinguish between full coverage of the non-injection molding area and partial coverage of the injection molding area, precisely protecting the non-etching area and ensuring that etching only acts on the target area to improve the consistency of the bonding surface. S4. When performing the etching operation, first ensure that the etching solution is sprayed on the thick film-covered area of the primary terminal. For the non-film-covered area of the etching injection area, the continuous spraying method is used. When spraying, control the spraying time on each side to be the same to ensure the same etching process. Avoid sharp burrs in the etched structure to reduce the risk of high-voltage breakdown. S5. After the etching is completed, the de-filming operation is carried out. After the de-filming is completed, the etched terminal is obtained, and then the injection molding operation is carried out at this time. S6. When performing injection molding, first determine the pressure and injection speed of the injection molding machine. By placing the etched terminal into the injection mold and starting the injection molding machine to inject the plastic material into the mold, control the injection speed and proceed slowly to prevent the fast injection speed from damaging the etched structure on the terminal surface. At the same time, control the fluidity of the plastic material in the injection molding machine and increase it. After the increase, perform injection molding at this time to ensure that the injected material can flow into the first etching groove 1011 and the second etching groove 102 on the surface of the etched terminal. After the injection molding is completed, perform the curing treatment to form the twists and turns of the wave peaks and wave valleys, increase the ruggedness of the air passage, so that under the power working environment of new energy vehicles, the automotive connector can still meet the sealing requirements. After injection molding, the injection molding block 2 formed by injection molding will naturally produce the injection molding large surface 201 and the injection molding small surface 202 corresponding to the first etching groove 1011 and the second etching groove 102. S7. After the curing treatment is completed, the deburring operation is carried out to remove the burrs on the surface of the injection molding block 2, and then the finished product of the terminal body 1 can be obtained.

[0022] Further, the metal strip is made of copper alloy.

[0023] Further, the etching solution used is FeCl 3 solution, and the mass concentration of the solution is 20%-28%.

[0024] Further, the film covering used is epoxy resin-based ink, and the de-filming operation uses DMAC for immersion treatment. By treating the hardware parts, the bonding surface area between the hardware and the plastic is increased, the air passage distance is extended and becomes more intricate, and at the same time, the bonding force between the plastic and the hardware is enhanced, so as to achieve good bonding and meet the requirements of gas sealing.

[0025] Further, during the injection molding operation, the initial injection speed is as low as 30%-50% of the rated value. After the etching groove has been blocked, the speed is increased to the rated value for injection molding. At the same time, according to the injection molding material, the temperature is appropriately increased to improve the fluidity of the injection molding material. By increasing the temperature, the fluidity of the plastic is increased, and at the same time, the two-stage injection speed is used to fully fill the etching groove, reducing the risks of bubbles and material shortage.

[0026] Experiment 1: Control group 1: Adopt the traditional injection molding mode of hardware terminals. Control Group 2: Traditional metal terminals using two-stage injection molding in the present invention; Experimental Group 1: The wave peaks and valleys are etched in the present invention, but two-stage injection molding is not used; Experimental Group 2: The wave peaks and valleys are etched in the present invention, and two-stage injection molding is used; The data is used to determine the airtightness strength, welding strength, and the retention rate of the welding strength after 200 cycles of testing in a thermal shock environment of -40°C to 85°C by monitoring the leakage amount with a test pressure of 250 KPa, a holding pressure time of 30 seconds, and a test time of 10 seconds: Category Leakage amount (Pa) Welding strength (MPa) Strength retention rate (%) Control group 1 80 30 85 Control group 2 76 32 86 Experimental group 1 40 44 95 Experimental group 2 28 50 98 In summary, it can be known that compared with the etched microstructure design, staged injection molding control, and environmentally friendly process chain integration in traditional metal terminals, this application achieves the comprehensive goals of high performance, low cost, and high reliability of the connector terminals, and is especially suitable for harsh scenarios such as high-voltage connectors in new energy vehicles.

[0027] Experiment 2: A film covering operation is performed on the surface of the processed primary terminal. After the film covering operation, special treatment is carried out on the area to be injection molded, that is, in the film covering area, a spray-type film covering is carried out once, that is, rough film covering, to ensure that the injection molding area of the primary terminal has a film covering area in 40 - 60% of the area. When performing the spray-type film covering, the non-injection molding area is also film covered at the same time. The film covering used for the non-injection molding area is full coverage. After the film covering is completed, an etching operation is carried out at this time. The epoxy resin-based ink film covering is used to distinguish between full coverage of the non-injection molding area and partial coverage of the injection molding area. The purpose of film covering the rough film covering area by spraying is to make there be some positions in the rough film covering area that are not film covered, which is convenient for the positions not covered by the film to be etched subsequently, and to protect the film covering area from being etched, accurately protecting the non-etched area, ensuring that the etching only acts on the target area, and improving the consistency of the bonding surface; The following experiments are carried out: Control Group 1: The surface of the traditional metal terminal is not treated as the control group; Control Group 2: The injection molding area of the primary terminal has a film covering in 40% of the area; Experimental Group 1: The injection molding area of the primary terminal has a film covering in 50% of the area; Experimental Group 2: The injection molding area of the primary terminal has a film covering in 60% of the area; With a test pressure of 250 KPa, a holding pressure time of 30 seconds, and a test time of 10 seconds, the leakage amount is monitored to determine the airtightness strength, welding strength, and the retention rate of the welding strength after 200 cycles of testing in a thermal shock environment of -40°C to 85°C for comparison: Category Leakage amount (Pa) Welding strength (MPa) Strength retention rate (%) Control group 1 80 30 85 Control group 2 36 45 92 Experimental group 1 28 50 98 Experimental group 2 24 46 91 The above results show that when 50% of the area has a film coating, the highest welding strength will be obtained. This is because an approximately equal proportion of crests and troughs are formed between the injection block 2, the first etching groove 1011, and the second etching groove 102, increasing the ruggedness of the air passage. At the same time, it can increase the welding strength and airtightness strength between the injection block 2, the first etching groove 1011, and the second etching groove 102, greatly improving the airtightness during the use of new energy vehicles.

[0028] Only some exemplary embodiments of the present invention have been described by way of illustration above. Undoubtedly, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. An automotive connector terminal, comprising a terminal body (1), characterized in that: A terminal injection molding surface (101) is provided in the middle of the terminal body (1), the upper and lower surfaces of the terminal injection molding surface (101) are provided with a first etching groove (1011), the left and right sides of the terminal injection molding surface (101) are provided with a second etching groove (102), the outer wall of the terminal injection molding surface (101) of the terminal body (1) is fixedly connected to an injection molding block (2), the inner wall of the injection molding block (2) and the position corresponding to the first etching groove (1011) of the terminal injection molding surface (101) are provided with a large injection molding surface (201), and the position corresponding to the second etching groove (102) of the injection molding block (2) is provided with a small injection molding surface (202).

2. A manufacturing process for an automobile connector terminal, implemented on the automobile connector terminal as claimed in claim 1, characterized in that: The following steps are included: S1. First, select a metal strip that meets the terminal manufacturing standards, electrolyze it at a current density of 3-5A / dm² and a temperature of 40-60℃, and then transport it to the stamping equipment, feed the metal strip into the mold for stamping, and stamp out a primary terminal with a terminal bending shape; S2, shearing the primary terminal after stamping; after shearing, removing burrs; after the burrs are removed, drilling holes on the terminal to drill connection holes for car connection; after drilling, cleaning, degreasing and drying the terminal; S3. Perform film lamination on the treated surface of the primary terminal. After the film lamination, perform special treatment on the area to be molded, that is, perform a spray lamination, i.e., rough lamination, on the film lamination area to ensure that the film lamination area exists in 40-60% of the injection molding area of ​​the primary terminal. When performing the spray lamination, the non-injection molding area is also film-laminated at the same time, and the film lamination used in the non-injection molding area is fully covered; S4. After the coating is completed, an etching operation is performed. First, the etching liquid is sprayed on the rough coating area of ​​the primary terminal, and the uncoated area of ​​the injection molding area is etched. The continuous spraying method is used to spray, and the spraying time of each side is controlled to be the same to ensure the same etching process; S5, after the etching is completed, a film stripping operation is performed to obtain an etched terminal, and then an injection molding operation is performed; S6. When performing injection molding, first determine the pressure and injection speed of the injection molding machine, place the etched terminal in the injection mold, start the injection molding machine to inject the plastic material into the mold, control the injection speed to prevent the injection speed from damaging the etched structure on the terminal surface due to excessive speed, and at the same time control the fluidity of the plastic material in the injection molding machine to increase it. After the fluidity is increased, perform injection molding to ensure that the injected material can flow into the first etching groove (1011) and the second etching groove (102) on the surface of the etched terminal. After the injection molding is completed, perform a curing process on it. S7. After taking out the injection molded part, perform a deburring operation to obtain a finished automotive connector terminal.

3. The manufacturing process of the automobile connector terminal according to claim 2, characterized in that: The metal strip is made of copper alloy.

4. The manufacturing process of the automobile connector terminal according to claim 2, characterized in that: The etching solution is FeCl3 solution, and the mass concentration of the solution is 20%-28%.

5. The manufacturing process of the automobile connector terminal according to claim 2, characterized in that: The coating is made of epoxy resin-based ink, and the film removal operation is carried out using DMAC, which is immersed in the film.

6. The manufacturing process of the automobile connector terminal according to claim 2, characterized in that: During the injection molding operation, the initial injection speed is as low as 30-50% of the rated value. After the etching groove has been blocked, the speed is increased to the rated value for injection molding. At the same time, according to the injection molding material, the temperature is appropriately increased to improve the fluidity of the injection molding material.

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