A roll-formed U-shaped crimp terminal and its manufacturing process

Abstract

The present invention discloses a roll-formed U-shaped crimp terminal and its manufacturing process, which includes selecting a continuous metal sheet of copper or copper alloy for cutting, performing precision rolling on the strip blank at the contact section of the terminal, and during the precision rolling process, by controlling the process parameters, forming two-sided arc surfaces K on the contact section of the terminal, performing chamfering on the cut surface at the front end of the contact section to form a U-shaped cut surface, and controlling the cut surface angle to be less than 90° to achieve inward inclination; machining an introduction area and a thinning transition area between the contact section and the connection section of the terminal, performing surface treatment and surface quality inspection on the terminal, and through the precision rolling technology, achieving a contact surface with low roughness, precisely controlling the thickness of the crimping area 110, the tip diameter, and the angle parameters of each key area, thereby effectively reducing the damage to the PCB plating layer and significantly improving the stability and reliability of the connection between the terminal and the PCB.

Description

Technical Field

[0001] The invention relates to the technical field of terminals, and in particular to a rolled U-shaped crimping terminal and a preparation process thereof. Background Art

[0002] With the rapid development of electronic information technology and the trend of electronic products towards miniaturization, lightweight and high integration, crimp terminals, as key contact elements between electronic components and printed circuit boards (PCBs), are widely used in automotive electronics, consumer electronics, communication equipment and industrial automation. Terminals are not only required to have good conductivity, but also need to maintain reliable mechanical and electrical connection performance in high-density and miniaturized application environments. Therefore, how to balance production efficiency and cost control while ensuring low contact resistance and stable connection has become an important technical problem that needs to be solved in the current industry.

[0003] In the prior art, the preparation process of crimping terminals mostly adopts traditional stamping, forming and crimping methods. These processes often make it difficult to accurately control the surface roughness of the contact area between the terminal contact surface and the PCB coating during the processing, resulting in a relatively rough contact surface, which can easily cause scratches or wear on the PCB coating during the crimping process, thereby reducing the reliability and durability of the connection. In addition, traditional processes have limitations in the control of the geometry and angles of key areas such as the terminal arc surface and cut surface. For example, the chamfering and filleting are not sufficiently processed, and the ideal inclination and edge smoothing effects cannot be achieved. These defects not only reduce the elasticity and contact force of the crimping terminal, but also may cause problems such as poor contact and increased contact resistance during long-term use.

[0004] In view of this, it is necessary to improve the crimping terminals in the prior art to solve the technical problem of wear caused by insufficient precision. Summary of the invention

[0005] The object of the present invention is to provide a rolled U-shaped crimping terminal and a preparation process thereof, so as to solve the above technical problems.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A preparation process of a rolled U-shaped crimping terminal, comprising:

[0008] Step S1, selecting a continuous metal sheet of copper or copper alloy and cutting it into strip blanks that meet the terminal size requirements;

[0009] Step S2, perform precision rolling on the strip blank at the contact section of the terminal. During precision rolling, by controlling process parameters, form two side arc surfaces K at the contact section of the terminal, such that the surface roughness of the rolling surface is ≤ 0.8 μm. At the same time, form a terminal with a U-shaped cross-section, with the thickness of the crimping area controlled within 0.10 - 0.50 mm, and the diameter of the terminal tip ≤ 0.30 mm;

[0010] Step S3, perform chamfering on the cut surface at the front end of the contact section to form a U-shaped cut surface, with the cut surface angle controlled to be less than 90° to achieve inward inclination; at the same time, perform rounding on the edge of the cut surface to make the minimum chamfer radius reach R0.05 mm;

[0011] Step S4, process and form an introduction area and a thinning transition area between the contact section and the connection section of the terminal. Among them, the guiding angle formed in the introduction area is ≤ 30°, the transition angle of the thinning transition area is ≤ 30°, and the length of the crimping area is controlled within 0.5 - 1.5 mm;

[0012] Step S5, perform surface treatment such as cleaning and deburring on the terminal, and then conduct surface quality inspection on the terminal, and sort according to the quality inspection results.

[0013] Optionally, step S1 specifically includes:

[0014] S11, select a continuous metal sheet with good plasticity and electrical conductivity as the raw material, which can be copper or copper alloy;

[0015] S12, after selecting the continuous metal sheet, it is necessary to check its surface. If there is surface contamination or oxide layer on its surface, perform surface cleaning;

[0016] S13, cut the cleaned metal sheet into strip blanks that meet the terminal size requirements, and control the width and length error of the metal sheet within ±0.1 mm during cutting.

[0017] Optionally, after step S13, it further includes:

[0018] S14, after cutting is completed, perform blank size verification to make the length, width, and thickness of each strip blank meet the design requirements;

[0019] S15, perform lubrication treatment on the cut strip blanks, and the lubricant for lubrication treatment includes oil-based lubricant or water-based lubricant.

[0020] Optionally, step S2 specifically includes:

[0021] S21. Clamp the obtained strip blank on the rolling mill, and use a positioning fixture to accurately align the predetermined contact section area of the terminal with the rolling area. At the same time, preset the spacing between each station and the center distance of the rolling rolls of the rolling mill.

[0022] S22. Select a rolling die that has been finely polished. Its surface has been specially hardened and polished to ensure that the surface roughness of the die is less than 0.5 μm. According to the design requirements of the terminal, preset the arc curvature parameters of the rolling die so that the arcs K formed on both sides have a consistent and uniform radian. At the same time, set the roll gap so that the thickness of the terminal crimping area after rolling is controlled within the range of 0.10 - 0.50 mm, and the tip forming diameter ≤ 0.30 mm.

[0023] S23. Before the precision rolling process, pre-treat the strip blank. The pre-treatment includes temperature balance and fine-tuning alignment. Use an automatic alignment device to detect the thickness and edge straightness of the blank.

[0024] S24. Start the rolling mill to perform precision rolling on the pre-treated blank. In the terminal contact section area, through continuous multi-pass micro-thinning processing, the formation of the arcs K on both sides is achieved. At the same time, the formation of the U-shaped cross-section is achieved through the design of the rolling die.

[0025] Optionally, after the step S24, it further includes:

[0026] S25. During the precision rolling process, configure an on-line measurement system to monitor the key process parameters in real time. The key process parameters include rolling pressure, rolling speed, material temperature, and surface roughness after forming. Use a feedback control system to automatically adjust the roll gap and feed speed.

[0027] S26. After rolling, perform directional cooling on the terminal. Use air cooling or water mist cooling methods to quickly bring the terminal to room temperature.

[0028] S27. After the rolling process is completed, use a surface roughness measuring instrument and a thickness measuring instrument to detect the arc surface of the terminal contact section, the U-shaped cross-section, and the tip size to ensure that all indicators meet the requirements of surface roughness ≤ 0.8 μm, crimping area thickness within 0.10 - 0.50 mm, and tip diameter ≤ 0.30 mm.

[0029] Optionally, the step S3 specifically includes:

[0030] S31. Before cutting the very front end of the terminal contact section, fix and position the terminal, and then use a laser measurement device to calibrate the position of the very front end of the terminal to ensure that the chamfering processing position is accurate with an error not exceeding ±0.01 mm.

[0031] S32. Use a numerically controlled cutting machine to chamfer the front end of the terminal contact section. The chamfering angle is usually set between 85° and 89°, and the feed rate during the cutting process should be set at 0.05 - 0.1 mm / s.

[0032] S33. After the chamfering process is completed, use a surface roughness meter to detect the surface quality of the chamfered area to ensure that the surface roughness does not exceed Ra0.8 μm.

[0033] Optionally, after step S33, the following steps are further included:

[0034] S34. After the chamfering process is completed, use a numerically controlled milling machine or a rounding tool to round the cutting edge of the chamfer. The rounding radius should be controlled at R0.05 mm. During the processing, the tool feed rate is usually set at 0.05 - 0.1 mm / s.

[0035] S35. After the chamfering and rounding processes are completed, cool the terminal. Specifically, use air cooling or liquid cooling to rapidly cool down the temperature. After cooling, use an ultrasonic cleaning device to remove burrs.

[0036] Optionally, step S4 specifically includes:

[0037] S41. In the transition area between the contact section and the connection section, first accurately position the terminal so that the transition area between the contact section and the connection section aligns with the forming die.

[0038] S42. Use a numerically controlled punching machine or stamping equipment to process the lead-in area of the terminal to ensure that the guiding angle of the lead-in area is controlled within ≤30°.

[0039] S43. After the lead-in area is formed, continue to process the thinning transition area between the terminal contact section and the connection section. The angle of the transition area is controlled within ≤30°. The processing of the thinning transition area uses a multi-pass step-by-step thinning technique, and the processing depth of each pass is controlled within 0.05 mm.

[0040] S44. After the lead-in area and the thinning transition area are processed, control the length of the crimping area. According to the design requirements, the length of the crimping area should be maintained between 0.5 - 1.5 mm. Specifically, use a laser measurement device to detect the crimping area in real time and adjust the feed rate and processing speed of the forming die.

[0041] Optionally, after step S44, the following steps are further included:

[0042] S45. After the processing is completed, use a digital microscope to detect the quality of the lead-in area, the transition area, and the crimping area to ensure that the angles and dimensions of each area meet the design requirements.

[0043] S46. After the processing of the introduction area, transition area, and crimping area is completed, a directional cooling treatment is carried out. Specifically, a liquid cooling or air cooling method is used to rapidly cool the processed terminals. After cooling, an ultrasonic cleaning device is used to remove impurities.

[0044] Compared with the prior art, the present invention has the following beneficial effects: First, a continuous metal sheet of copper or copper alloy is selected and cut into strip blanks that meet the terminal size requirements. Through precision rolling processing, arc surfaces K are formed on both sides at the terminal contact section, the surface roughness of the rolling surface is ≤0.8 μm, and it is ensured that the cross-section of the terminal is U-shaped, the thickness of the crimping area is 0.10 - 0.50 mm, and the diameter of the terminal tip is ≤0.30 mm. Subsequently, chamfering and rounding are performed on the cut surface at the very front end of the contact section to form an inwardly inclined U-shaped cut surface, further reducing sharp edges and avoiding damage to the PCB plating. An introduction area and a thinning transition area are processed between the contact section and the connection section of the terminal, ensuring that the guiding angle of the introduction area is ≤30°, the angle of the transition area is ≤30°, and the length of the crimping area is between 0.5 - 1.5 mm, ensuring that the terminal structure has good elasticity and contact force. The terminals are cleaned, deburred, and surface quality inspected, and sorted according to the inspection results to ensure that the products meet the quality standards. The preparation process of the roll-formed U-shaped crimping terminal proposed by the present invention realizes a low-roughness contact surface, precisely controls the thickness of the crimping area, the tip diameter, and the angle parameters of each key area through precision rolling technology, thereby effectively reducing the damage to the PCB plating and significantly improving the stability and reliability of the connection between the terminal and the PCB. Description of the Drawings

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0046] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention.

[0047] Figure 1 It is one of the flow diagrams of the preparation process of the roll-formed U-shaped crimping terminal of this embodiment;

[0048] Figure 2It is the second flow schematic diagram of the preparation process of the U-shaped crimp terminal formed by rolling in this embodiment;

[0049] Figure 3 It is the overall structure schematic diagram of the U-shaped crimp terminal formed by rolling in this embodiment;

[0050] Figure 4 It is the half-sectional structure schematic diagram of the U-shaped crimp terminal formed by rolling in this embodiment;

[0051] Figure 5 It is the schematic diagram of the cut surface 120 of the U-shaped crimp terminal formed by rolling in this embodiment;

[0052] Figure 6 It is the insertion structure schematic diagram of the U-shaped crimp terminal formed by rolling in this embodiment and the PCB. Specific embodiments

[0053] To make the invention purpose, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0054] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component present at the same time.

[0055] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific embodiments.

[0056] Combined with Figures 1 to 6 As shown, the embodiments of the present invention provide a preparation process for a U-shaped crimp terminal formed by rolling, including:

[0057] Step S1, select a continuous metal sheet of copper or copper alloy, cut it into a strip blank that meets the terminal size requirements, and cut the continuous metal sheet with good plasticity and electrical conductivity (such as copper or copper alloy) into a strip blank that meets the terminal size requirements to provide raw materials for subsequent forming processing.

[0058] Step S2, perform precision rolling on the strip blank at the contact section 100 of the terminal. During the precision rolling process, by controlling the process parameters, form two-sided arc surfaces K on the contact section 100 of the terminal, making the surface roughness of the rolling surface ≤ 0.8 μm. At the same time, form a terminal with a U-shaped cross-section, with the thickness of the crimping area 110 controlled within 0.10 - 0.50 mm, and the tip diameter of the terminal ≤ 0.30 mm.

[0059] Step S3, chamfer the cut surface 120 at the front end 101 of the contact section 100 to form a U-shaped cut surface 120, with the angle of the cut surface 120 controlled to be less than 90° (negative angle) to achieve inward inclination. At the same time, round the edges of the cut surface 120 to make the minimum chamfer radius reach R0.05 mm, thereby eliminating sharp edges and reducing damage to the PCB plating.

[0060] Step S4, machine an introduction area 300 and a thinning transition area 400 between the contact section 100 and the connection section 200 of the terminal. Among them, the guiding angle formed by machining the introduction area 300 ≤ 30°, the transition angle of the thinning transition area 400 ≤ 30°, and the length of the crimping area 110 is controlled within 0.5 - 1.5 mm, ensuring a smooth transition of the terminal thickness and good elasticity to provide a reliable contact force.

[0061] Step S5, perform surface treatment on the terminal, including cleaning and deburring, and then conduct surface quality inspection on the terminal, and sort according to the quality inspection results.

[0062] Ensure the surface of the terminal is clean. During the processing, strictly control and ensure that the remaining thickness of the PCB plating ≥ 20 μm to maintain sufficient conductivity and wear resistance. Inspect the key dimensions, surface roughness, and forming quality of each area of the terminal to ensure that the product meets the design requirements.

[0063] The working principle of the present invention is as follows: first, a continuous metal sheet of copper or copper alloy is selected and cut into a strip blank that meets the terminal size requirements. Through fine rolling, two side arc surfaces K are formed at the terminal contact section 100, and the surface roughness of the rolled surface is ≤0.8μm. It is ensured that the terminal cross section is U-shaped, the thickness of the crimping area 110 is 0.10-0.50mm, and the terminal needle tip diameter is ≤0.30mm; then, the front end 101 of the contact section 100 is chamfered and rounded to form an inward U-shaped cut surface 120, further reducing sharp edges and avoiding damage to the PCB plating. The lead-in area 3 is formed between the contact section 100 and the connecting section 200 of the terminal. 00 and thinning transition zone 400, ensuring that the guide angle of the introduction zone 300 is ≤30°, the angle of the transition zone is ≤30°, and the length of the crimping zone 110 is between 0.5 and 1.5 mm, ensuring that the terminal structure has good elasticity and contact force, the terminals are cleaned and deburred, and surface quality inspection is performed, and sorting is performed according to the inspection results to ensure that the products meet quality standards. The preparation process of the roll-formed U-shaped crimping terminal proposed in the present invention realizes a low-roughness contact surface through fine rolling technology, accurately controls the thickness of the crimping zone 110, the needle tip diameter and the angle parameters of each key area, thereby effectively reducing the damage to the PCB coating, and significantly improving the stability and reliability of the connection between the terminal and the PCB.

[0064] In this embodiment, it is specifically explained that step S1 specifically includes:

[0065] S11, selecting a continuous metal sheet with good plasticity and electrical conductivity as a raw material, which may be copper or a copper alloy;

[0066] The selected material should have properties suitable for subsequent plastic processing, and should have high conductivity, good corrosion resistance and weldability. Copper alloy materials (such as C1100 or C1020) are widely used in the manufacture of such terminals because of their excellent conductivity and strong plasticity, which can adapt to the requirements of precision molding process.

[0067] S12, after the continuous metal sheet is selected, its surface needs to be inspected, and if there is surface contamination or an oxide layer on its surface, the surface is cleaned;

[0068] Ensure that there is no obvious oxidation, stains, scratches or other defects that affect the quality of subsequent processing. If surface contamination or oxide layer is found, it should be removed by chemical cleaning or mechanical cleaning to ensure that the material surface is clean and has good lubricity. Common cleaning methods include pickling or mechanical polishing to ensure that no undesirable surface defects are produced during subsequent processing.

[0069] S13, cutting the cleaned metal sheet into strip blanks that meet the terminal size requirements, and controlling the width and length errors of the metal sheet within ±0.1mm during cutting.

[0070] The cutting process should use precision cutting equipment to ensure the accuracy of cutting and the surface flatness. When cutting, control the width and length errors of the metal sheet within ±0.1 mm to meet the dimensional requirements of the subsequent forming process. It is recommended to use laser cutting or precision stamping equipment for cutting to ensure smooth edges and no excessive heat-affected zone.

[0071] The thickness of the cut metal blank should be precisely controlled according to the terminal size requirements. Usually, the thickness of the metal sheet used should be between 0.1 mm and 0.5 mm, and the specific value is determined according to the thickness of the crimping area 110 of the terminal design. To ensure the smooth progress of the subsequent rolling process, the error of the metal sheet thickness should be controlled within ±0.02 mm to avoid affecting the crimping effect. If the selected material thickness is inappropriate, preliminary thickness adjustment should be carried out by methods such as rolling or calendering.

[0072] S14. After cutting is completed, conduct blank size verification to make the length, width, and thickness of each strip blank meet the design requirements;

[0073] The key to this step lies in the strict control of dimensional accuracy to prevent process defects caused by dimensional errors in subsequent processing. At this time, it can be detected by high-precision measuring equipment (such as a laser rangefinder or a digital caliper) to ensure that the error is within the specified tolerance range.

[0074] S15. It is recommended to lubricate the cut strip blanks. The lubricants for lubrication treatment include oil-based lubricants or water-based lubricants.

[0075] In order to reduce the friction between the metal and the equipment during the subsequent processing and prevent damage to the metal surface due to excessive friction, it is recommended to lubricate the cut metal blanks. Common lubricants include oil-based lubricants or water-based lubricants, and the selection of lubricants should be reasonably matched according to the type of metal material and the processing technology requirements. The lubricating layer should be evenly distributed to avoid poor processing caused by too much or too little lubricant.

[0076] In this embodiment, specifically, step S2 specifically includes:

[0077] S21. Clamp the obtained strip blank on the rolling mill, and use the positioning fixture to accurately align the predetermined contact section 100 area of the terminal with the rolling area; at the same time, preset the spacing between each station and the center distance of the rolling rolls of the rolling mill;

[0078] Ensure that thickness reduction and arc forming can be accurately achieved in subsequent processing. In this preset step, a laser positioning device can be used for assistance, and the positioning accuracy is controlled within ±0.01 mm.

[0079] S22. Select a rolled die that has been finely polished. Its surface has been specially hardened and polished to ensure that the surface roughness of the die is less than 0.5 μm. According to the design requirements of the terminal, preset the arc curvature parameters of the rolled die so that the arcs K formed on both sides have a consistent and uniform radian. At the same time, set the roll gap so that the thickness of the terminal crimping area 110 after rolling is controlled within the range of 0.10 - 0.50 mm, and the tip forming diameter ≤ 0.30 mm;

[0080] This helps to control the roughness of the surface transferred to the terminal rolling surface within ≤ 0.8 μm.

[0081] S23. Before the precision rolling process, pre-treat the strip blank. The pre-treatment includes temperature balancing and fine-tuning centering. Use an automatic centering device to detect the thickness and edge straightness of the blank;

[0082] Use an automatic centering device to detect the thickness and edge straightness of the blank, so that the blank is evenly stressed during the rolling process, preventing local thinning or local residual stress. This correction step helps to ensure that the formed U-shaped cross-section and arc K meet the design requirements during the subsequent forming process.

[0083] S24. Start the rolling mill to perform precision rolling on the pre-treated blank. In the area of the terminal contact section 100, through continuous multi-pass micro-thinning processing, the formation of the arcs K on both sides is achieved, and at the same time, the formation of the U-shaped cross-section is achieved through the rolled die design;

[0084] In each rolling process, strictly control the roll pressure, rolling speed, and feed rate to ensure that the surface of the terminal gradually meets the requirement of low roughness (≤ 0.8 μm) during multiple rollings. At the same time, through the rolled die design, the formation of the U-shaped cross-section is achieved, ensuring that the thickness of the crimping area 110 is maintained within 0.10 - 0.50 mm, and accurately controlling the terminal tip diameter within the range of ≤ 0.30 mm.

[0085] S25. During the precision rolling process, configure an on-line measurement system to monitor the key process parameters in real time. The key process parameters include rolling pressure, rolling speed, material temperature, and surface roughness after forming. Use a feedback control system to automatically adjust the roll gap and feed speed;

[0086] So as to correct the deviation immediately during the rolling process, ensuring that each batch of products meets the predetermined technical parameters. This innovative measure can effectively improve the forming accuracy and stabilize the U-shaped cross-section and tip size.

[0087] S26. After rolling, perform directional cooling on the terminal. Adopt air cooling or water mist cooling methods to quickly bring the terminal to room temperature;

[0088] Thus, internal stress concentration or dimensional deformation caused by uneven temperature is prevented. During the cooling process, the ambient temperature and humidity are kept stable to ensure the long-term stability of the shape and dimensions of the finished product after rolling.

[0089] S27, after the rolling process is completed, a surface roughness measuring instrument and a thickness measuring instrument are used to detect the arc surface, U-shaped cross-section, and tip size of the contact section 100 of the terminal, ensuring that all indicators meet the requirements of a surface roughness ≤ 0.8 μm, a thickness of the crimping area 110 between 0.10 and 0.50 mm, and a tip diameter ≤ 0.30 mm.

[0090] The detection data is uploaded to the industrial control system in real time to form a complete process data file, providing a basis for subsequent quality traceability and process optimization.

[0091] In this embodiment, specifically, step S3 specifically includes:

[0092] S31, before cutting off the front end 101 of the contact section 100 of the terminal, the terminal is fixed and positioned, and then a laser measuring device is used to calibrate the position of the front end 101 of the terminal to ensure that the chamfering position is accurate with an error not exceeding ±0.01 mm;

[0093] A high-precision fixture is used to firmly fix the terminal to ensure its stability during the chamfering process. At this time, a laser measuring device is used to accurately calibrate the position of the front end 101 of the terminal to ensure that the chamfering position is accurate with an error not exceeding ±0.01 mm. After positioning, the feed speed and tool angle of the cutting machine are set to ensure subsequent processing accuracy.

[0094] S32, a numerical control cutting machine is used to chamfer the front end 101 of the contact section 100 of the terminal. The chamfering angle is usually set between 85° and 89°, and the feed speed during the cutting process should be set at 0.05 - 0.1 mm / s;

[0095] The key to this process is to control the feed speed and cutting angle of the tool. The chamfering angle should be precisely controlled to be less than 90°, and the tool should have high hardness and wear resistance to ensure stability during the processing. The chamfering angle is usually set between 85° and 89°, and is specifically selected according to the structure and application requirements of the terminal. The feed speed during the cutting process should be set at 0.05 - 0.1 mm / s to ensure a smooth cutting surface and prevent material overheating.

[0096] S33, after the chamfering process is completed, a surface roughness instrument is used to detect the surface quality of the chamfered area to ensure that the surface roughness does not exceed Ra0.8 μm.

[0097] Strictly control the roughness of the cutting surface to avoid burrs or rough cutting marks on the surface. In addition, use special tools to slightly polish the chamfered surface to ensure that the chamfered surface is smooth and free of burrs, thereby further reducing the risk of damage to the PCB plating.

[0098] S34, after the chamfering process is completed, use a CNC milling machine or a rounding tool to round the cutting edge of the chamfer. The rounding radius should be controlled at R0.05 mm. During the processing, the tool feed rate is usually set at 0.05 - 0.1 mm / s;

[0099] Avoid sharp edges from scratching the PCB plating. The rounding tool should be kept sharp to ensure stable cutting quality during the processing. During the processing, the tool feed rate is usually set at 0.05 - 0.1 mm / s to ensure a uniform rounding radius.

[0100] S35, after the chamfering and rounding processes are completed, cool the terminals. Specifically, use air cooling or liquid cooling to rapidly reduce the temperature. After cooling, use an ultrasonic cleaning device to remove burrs;

[0101] Cooling treatment is carried out to avoid dimensional deviation caused by heat accumulation. Use air cooling or liquid cooling to rapidly reduce the temperature to ensure the stable shape of the terminals. After cooling, use an ultrasonic cleaning device to remove burrs, removing the tiny burrs that may be generated during cutting and rounding processes, ensuring the cleanliness of the terminal surface and avoiding affecting the subsequent crimping effect.

[0102] After each terminal completes the chamfering and rounding processes, strict dimensional and quality inspections should be carried out. Use a high-precision digital microscope to detect the angle of the chamfer to ensure that it is less than 90° and the error does not exceed ±1°. In addition, use a surface roughness meter to detect the chamfered surface and the rounding edge to ensure that the roughness meets the requirement of Ra0.8 μm and the rounding radius reaches R0.05 mm. All inspection data should be recorded and archived in real time for easy traceability and quality control.

[0103] In this embodiment, specifically, step S4 specifically includes:

[0104] S41, in the transition region between the contact section 100 and the connection section 200, first accurately position the terminal so that the transition region between the contact section 100 and the connection section 200 is aligned with the forming die;

[0105] During the forming process, use a laser to position the entire terminal and ensure that the processing positions and accuracies of the introduction area 300 and the thinning transition area 400 meet the design requirements. The goal of this step is to ensure that both the introduction area 300 and the thinning transition area 400 can have a smooth transition and no material defects.

[0106] S42. Use a numerically controlled punching machine or stamping equipment to process the insertion area 300 of the terminal, ensuring that the guiding angle of the insertion area 300 is controlled within ≤ 30°.

[0107] The processing of the insertion area 300 should ensure that no cracks or other defects occur during the deformation of the metal material. During operation, the stamping speed and pressure should be strictly controlled to avoid excessive pressure causing over-compression or stretching of the material. Usually, the stamping pressure is 10 - 20 tons, and the feeding speed is controlled within the range of 0.05 - 0.1 mm / s.

[0108] S43. After the insertion area 300 is formed, continue to process the thinning transition area 400 between the terminal contact section 100 and the connection section 200. The angle of the transition area is controlled within ≤ 30°. The processing of the thinning transition area 400 adopts a multi-pass step-by-step thinning technique, and the processing depth of each pass is controlled within 0.05 mm.

[0109] To ensure uniform distribution of the contact force between the terminal and the PCB plating hole and avoid poor contact caused by excessive contact force. The processing of the thinning transition area 400 adopts a multi-pass step-by-step thinning technique to gradually reduce the thickness of the transition area to ensure a smooth transition of the overall thickness. The processing depth of each pass should be controlled within 0.05 mm to avoid excessive deformation of the material.

[0110] S44. After the processing of the insertion area 300 and the thinning transition area 400 is completed, control the length of the crimping area 110. According to the design requirements, the length of the crimping area 110 should be maintained between 0.5 - 1.5 mm. Specifically, use a laser measurement device to detect the crimping area 110 in real time and adjust the feeding amount and processing speed of the forming die.

[0111] This step uses a laser measurement device to detect the crimping area 110 in real time and adjust the feeding amount and processing speed of the forming die to ensure that the length of the crimping area 110 of each terminal is accurate. During the processing, the equipment should maintain a constant speed and pressure to avoid errors in the length of the crimping area 110 caused by speed changes.

[0112] S45. After processing, use a digital microscope to inspect the quality of the insertion area 300, the transition area, and the crimping area 110 to ensure that the angles and dimensions of each area meet the design requirements.

[0113] In particular, use a digital measuring instrument to detect the guiding angle of the insertion area 300, the angle of the transition area, and the length of the crimping area 110 to ensure that their errors are controlled within ±0.01 mm. The dimensional data of each batch of products should be recorded and archived in real time to provide guarantee for quality traceability.

[0114] To ensure high precision during the processing, a real-time feedback system and an intelligent detection platform are adopted to dynamically monitor the forming conditions in the introduction area 300 and the transition area. Through sensors, optoelectronic measuring devices, and data analysis systems, automatic compensation is performed for the tiny errors that occur during the forming process. The innovative feedback system can adjust the stamping pressure, feed speed, and the clearance of the processing die in real time to maintain the stability of each process parameter and ensure the consistency of product quality.

[0115] S46, after the processing of the introduction area 300, the transition area, and the crimping area 110 is completed, a directional cooling treatment is carried out. Specifically, liquid cooling or air cooling is used to rapidly cool the processed terminals. After cooling, an ultrasonic cleaning device is used to remove impurities.

[0116] To reduce the internal stress generated during the processing. By using liquid cooling or air cooling, the processed terminals are rapidly cooled to avoid the deformation of the terminal shape or inaccurate dimensions caused by excessive temperature difference. After cooling, an ultrasonic cleaning device is used to remove the residues and impurities generated during the processing to ensure the cleanliness and high quality of the terminals.

[0117] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A preparation process for a rolled and formed U-shaped crimp terminal, characterized in that, Including: Step S1: Select a continuous metal sheet of copper or copper alloy and cut it into strip blanks that meet the terminal size requirements. Step S2: Perform precision rolling on the strip blanks at the contact section of the terminal. During the precision rolling process, by controlling process parameters, form two-sided arc surfaces K on the contact section of the terminal, making the surface roughness of the rolling surface ≤ 0.8 μm. At the same time, form a terminal with a U-shaped cross-section, with the thickness of the crimping area controlled within 0.10 - 0.50 mm and the tip diameter of the terminal ≤ 0.30 mm. Step S3: Perform chamfering on the cut surface at the very front end of the contact section to form a U-shaped cut surface, with the cut surface angle controlled to be less than 90° to achieve inward inclination. At the same time, perform rounding on the edge of the cut surface to make the minimum chamfer radius reach 0.05 mm. Step S4: Process and form an introduction area and a thinning transition area between the contact section and the connection section of the terminal. Among them, the guiding angle formed in the introduction area ≤ 30°, the transition angle of the thinning transition area ≤ 30°, and the length of the crimping area is controlled within 0.5 - 1.5 mm. Step S5: Perform surface treatment such as cleaning and deburring on the terminal, and then conduct surface quality inspection on the terminal, and sort according to the quality inspection results. Among them, the specific steps of Step S2 include: S21: Clamp the obtained strip blanks on a rolling mill, and use a positioning fixture to accurately align the predetermined contact section area of the terminal with the rolling area. At the same time, preset the spacing between each working position and the center distance of the rolling rolls of the rolling mill. S22: Select a rolling die that has been finely polished, whose surface has been hardened and polished, ensuring that the surface roughness of the die is lower than 0.5 μm. According to the terminal design requirements, preset the arc curvature parameters of the rolling die to make the two-sided arc surfaces K formed have consistent and uniform radian. At the same time, set the roll gap so that the thickness of the crimping area of the terminal after rolling is controlled within the range of 0.10 - 0.50 mm, and the tip forming diameter ≤ 0.30 mm. S23: Before the precision rolling process, perform pre-treatment on the strip blanks. The pre-treatment includes temperature balance and fine alignment. Use an automatic alignment device to detect the thickness and edge straightness of the blanks. S24: Start the rolling mill to perform precision rolling on the pre-treated blanks. In the contact section area of the terminal, through continuous multi-pass micro-thinning processing, form the two-sided arc surfaces K, and at the same time, achieve the formation of the U-shaped cross-section through the design of the rolling die.

2. The preparation process of the U-shaped crimp terminal formed by rolling according to claim 1, characterized in that, The specific steps of Step S1 include: S11: Select a continuous metal sheet with good plasticity and electrical conductivity as the raw material, and the raw material is copper or copper alloy. S12: After selecting the continuous metal sheet, it is necessary to check its surface. If there is surface contamination or oxide layer on its surface, perform surface cleaning. S13: Cut the cleaned metal sheet into strip blanks that meet the terminal size requirements, and control the width and length error of the metal sheet within ±0.1 mm during cutting.

3. The preparation process of the U-shaped crimp terminal formed by rolling according to claim 2, characterized in that, After Step S13, it also includes: S14: After cutting, perform blank size verification to make the length, width, and thickness of each strip blank meet the design requirements. S15. Lubricate the cut strip-shaped blank. The lubricant for lubrication treatment includes oil-based lubricant or water-based lubricant.

4. The preparation process of the U-shaped crimp terminal formed by rolling according to claim 1, characterized in that, After the step S24, the following steps are further included: S25. During the precision rolling process, configure an on-line measurement system to monitor the key process parameters in real time. The key process parameters include rolling pressure, rolling speed, material temperature, and surface roughness after forming. Use a feedback control system to automatically adjust the roll gap and feed speed; S26. After rolling, conduct directional cooling treatment on the terminals. Adopt air cooling or water mist cooling methods to quickly bring the terminals to room temperature; S27. After the rolling process is completed, use a surface roughness measuring instrument and a thickness measuring instrument to detect the arc surface of the contact section, U-shaped cross-section, and tip size of the terminals, and ensure that all indicators meet the requirements of surface roughness ≤ 0.8μm, crimping area thickness between 0.10 - 0.50mm, and tip diameter ≤ 0.30mm.

5. The preparation process of the U-shaped crimping terminal formed by rolling according to claim 1, characterized in that, The step S3 specifically includes: S31. Before cutting the front end of the contact section of the terminal, fix and position the terminal, and then use a laser measurement device to calibrate the position of the front end of the terminal to ensure the accuracy of the chamfering processing position, with an error not exceeding ±0.01mm; S32. Use a numerical control cutting machine to perform chamfering processing on the front end of the contact section of the terminal. The set chamfering angle is between 85° and 89°, and the feed speed during the cutting process should be set at 0.05 - 0.1mm / s; S33. After the chamfering processing is completed, use a surface roughness instrument to detect the surface quality of the chamfered area and ensure that the surface roughness does not exceed 0.8μm.

6. The preparation process of the U-shaped crimp terminal formed by rolling according to claim 5, characterized in that, After the step S33, the following steps are further included: S34. After the chamfering processing is completed, use a numerical control milling machine or a rounding tool to perform rounding processing on the cutting edge of the chamfer, and the rounding radius should be controlled within 0.05mm. During the processing, the tool feed speed is set at 0.05 - 0.1mm / s; S35. After the chamfering and rounding processing are completed, conduct cooling treatment on the terminals, specifically by quickly reducing the temperature using air cooling or liquid cooling methods. After cooling, use an ultrasonic cleaning device to perform deburring treatment.

7. The preparation process of the U-shaped crimp terminal formed by rolling according to claim 1, characterized in that, The step S4 specifically includes: S41. In the transition area between the contact section and the connection section, first accurately position the terminal so that the transition area between the contact section and the connection section is aligned with the forming die; S42. Use a numerical control punching machine or stamping equipment to process the lead-in area of the terminal and ensure that the guiding angle of the lead-in area is controlled within ≤ 30°; S43. After the lead-in area is formed, continue to process the thinning transition area between the contact section and the connection section of the terminal. The angle of the transition area is controlled within ≤ 30°. The processing of the thinning transition area adopts a multi-pass step-by-step thinning technology, and the processing depth of each pass is controlled within 0.05mm; S44. After the lead-in area and the thinning transition area are processed, control the length of the crimping area. According to the design requirements, the length of the crimping area should be maintained between 0.5 - 1.5mm; specifically, use a laser measurement device to detect the crimping area in real time and adjust the feed amount and processing speed of the forming die.

8. The preparation process of the U-shaped crimp terminal formed by rolling according to claim 7, characterized in that, After the step S44, the following steps are further included: S45, after processing is completed, use a digital microscope to conduct quality inspections on the lead-in area, transition area, and crimping area to ensure that the angles and dimensions of each area meet the design requirements; S46, after the processing of the lead-in area, transition area, and crimping area is completed, conduct directional cooling treatment, specifically by using liquid cooling or air cooling methods to rapidly cool the processed terminals. After cooling, use an ultrasonic cleaning device to remove impurities.

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