A hairpin wire production mold and a design method thereof

Abstract

The application discloses a hairpin wire production mold and a design method thereof. The design method of the hairpin wire production mold comprises the following steps: step 1, constructing a three-dimensional model diagram of a target hairpin wire in a three-dimensional model, and obtaining a central axis of the target hairpin wire from the three-dimensional model diagram; step 2, calculating a springback compensation value of the target hairpin wire, and reconstructing a three-dimensional model diagram of the hairpin wire before springback in the three-dimensional model according to the springback compensation value; and step 3, constructing the hairpin wire production mold in the three-dimensional model according to the three-dimensional model diagram of the hairpin wire before springback. The springback compensation value is designed into the mold during mold design, so that the hairpin wire before springback, which is produced by the designed mold, can spring back by itself after being taken out of the mold, and the target hairpin wire is obtained.

Description

Technical Field

[0001] This invention belongs to the field of mold technology, and in particular relates to a hairpin wire production mold and its design method. Background Technology

[0002] With the continuous development of the new energy vehicle industry, the requirements for lightweight motors are becoming increasingly stringent. Hairpin winding motors offer advantages such as high slot fill factor, high efficiency, light weight, and low cost; however, their manufacturing process is relatively complex. In particular, the shape of the hairpin wires is a spatial curved surface, making one-time molding difficult. To ensure the motor's temperature and insulation performance, multiple layers of hairpin wires must be stacked, and a reasonable theoretical gap must be maintained between each wire. This places high demands on the surface profile of the hairpin wires, increasing the difficulty of molding. Especially after molding, the hairpin wires exhibit a certain amount of springback under stress, resulting in a discrepancy between the actual manufactured hairpin wire shape and the designed target shape. Therefore, mold design is a key factor restricting the molding of hairpin wires.

[0003] Currently, the hair clip wire blank 1c used to manufacture the target hair clip wire 1a is U-shaped, with a V-shaped section 11 at the midpoint and parallel pins 12 at both ends, all lying in the same plane. When the mold shapes the hair clip wire blank 1c, it presses the V-shaped section 11 relative to the two pins 12 at a certain angle, and presses a twisted section 111, which tends to be "~", at the tip of the V-shaped section 11. The springback of the hair clip wire mainly occurs at the connection between the V-shaped section 11 and the pins 12. After the hair clip wire springs back, the angle between the connection between the pins 12 and the V-shaped section 11 in the lateral projection plane increases, and the vertical distance between the twisted section 111 and the plane containing the two pins 12 decreases. The structure of the target hair clip wire 1a is shown below. Figures 1-3 As shown. Summary of the Invention

[0004] To solve the above-mentioned technical problems, one of the objectives of this invention is to provide a hairpin wire production mold design method that pre-compensates the springback allowance of the hairpin wire. The hairpin wire produced by the mold is a pre-springback hairpin wire, and the pre-springback hairpin wire will automatically spring back to the target hairpin wire after being taken out of the mold.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A method for designing a hairpin wire production mold, comprising the following steps:

[0006] Step 1: Construct a 3D model of the target hairpin wire in the 3D model, and obtain the center axis of the target hairpin wire from the 3D model;

[0007] Step 2: Calculate the springback compensation value of the target hairpin wire, and reconstruct the 3D model of the hairpin wire before springback in the 3D model based on the springback compensation value;

[0008] Step 3: Construct the hairpin wire production mold in the 3D model based on the 3D model drawing of the hairpin wire before springback.

[0009] The beneficial effect of the technical solution of the present invention is that by designing the springback compensation value into the mold design, the springback hairpin wire made by the designed mold will spring back on its own after being taken out of the mold, and the target hairpin wire will be obtained.

[0010] The present invention can be further improved in the following ways based on the above technical solution:

[0011] Furthermore, the method for calculating the springback compensation value in step 2 is as follows:

[0012] In the 3D model, the distance W between the centers of the two pins of the target hairpin wire and the height H of the tip of the target hairpin wire are measured respectively.

[0013] The displacement compensation value of the target hairpin wire is h=W / m, where m=100; the single-sided angle compensation value of the center line of the target hairpin wire is β=arctan((H+h) / 0.5W)-arctan(H / 0.5W);

[0014] The displacement compensation value h and the single-sided angle compensation value β are the rebound compensation values.

[0015] The beneficial effect of the above-mentioned further technical solution is that the displacement compensation amount h can compensate for the shortening of the vertical distance between the torsional part and the plane where the two PINs are located, while the single-sided angle compensation value β can compensate for the increase in the angle between the PIN and the V-shaped part in the lateral projection plane after the rebound.

[0016] The second objective of this invention is to provide a hair clip wire production mold that is simple in structure, highly efficient in production, and has a simplified production process.

[0017] To achieve the above objectives, the technical solution of the present invention is as follows: A hairpin wire production mold, manufactured according to the hairpin wire production mold design method described above, includes a lower mold, an upper mold, and guide pillars. The lower mold and the upper mold are both horizontally arranged in the left-right direction. A cavity is recessed in the middle of the upper end of the lower mold. Two guide pillars are provided, and the two guide pillars are respectively vertically arranged at both ends of the lower mold. Vertical through guide holes are provided at both ends of the upper mold. Each guide pillar passes through the corresponding guide hole. A punch that mates with the cavity is protruding in the middle of the lower end of the upper mold. The hairpin wire blank is placed horizontally on the lower mold in the front-back direction, and the V-shaped part is suspended in the cavity. The open end of the hairpin wire blank faces forward. The upper mold moves downward under the action of external force to press the hairpin wire blank down to form the springback hairpin wire.

[0018] The beneficial effects of the above-mentioned technical solution of the present invention are as follows: the hairpin wire blank is placed horizontally on the lower mold in the front-back direction, with the pins facing forward and the V-shaped part located above the cavity. When the upper mold is pressed down, the punch can cooperate with the cavity to press the V-shaped part down to bend downward relative to the pins, so as to obtain the hairpin wire before springback. When the upper mold moves upward to reset, the hairpin wire before springback will have its V-shaped part slightly spring back upward relative to the pins under its own stress, thus obtaining the target hairpin wire.

[0019] The present invention can be further improved in the following ways based on the above technical solution:

[0020] Furthermore, the lower mold has a recessed area formed by a downward indentation in the middle. The walls on both sides of the recessed area are sloped surfaces that cooperate with the V-shaped part in the middle of the springback hairpin wire. A rear limiting block is protruding in the middle of the rear end of the recessed area, and a front limiting block is protruding in the middle of the front end of the recessed area. The rear side of the front limiting block protrudes in an isosceles triangle to form a supporting surface. The supporting surface cooperates with the inner side of the middle of the hairpin wire blank. The recessed area has a protruding ridge in the middle between the rear limiting block and the front limiting block that cooperates with the torsion part. The front limiting block and the rear limiting block enclose the cavity in the recessed area.

[0021] The beneficial effect of the above-mentioned further technical solution is that the front limit block and the rear limit block clamp the tip of the V-shaped part between them, and the supporting surface fits with the inner side of the V-shaped part to limit the two sides of the V-shaped part. This can prevent the V-shaped part from deforming under the downward pressure of the upper mold, thus preventing the product from being unqualified.

[0022] Furthermore, the center of the front side of the punch is recessed rearward to form a relief groove that matches and fits against the supporting surface.

[0023] The beneficial effect of the above-mentioned further technical solution is that the V-shaped part is pressed under the punch and fits against the supporting surface, which is conducive to the V-shaped part bending downwards against the supporting surface under the action of the upper die.

[0024] Furthermore, lower support blocks are provided on both sides of the front end of the lower mold corresponding to the slope, and upper pressure blocks are provided on both sides of the front end of the upper mold. The two lower support blocks correspond one-to-one with the two upper pressure blocks. The upper end of the lower support block is an inclined guide surface, and the guide surface is aligned with the corresponding part of the slope on the same side. The lower end surface of the upper pressure block is an inclined mating surface, and the mating surface mates with the guide surface on the same side. The lower end of the mating surface is recessed with a meshing groove distributed in the front-back direction. When the hairpin wire blank is placed on the lower mold, the two pins are supported on the two guide surfaces. When the upper mold is pressed down under the action of external force, the V-shaped part bends downward and drives the two pins to slide closer to each other until the two pins abut against the two meshing grooves.

[0025] The beneficial effects of the above-mentioned further technical solution are as follows: When the hair clip wire blank is placed on the lower mold, the connection between the two pins and the V-shaped part can be supported by the two lower support blocks, and the V-shaped part is embedded between the front limit block and the rear limit block. At this time, the hair clip wire blank can remain stable in a horizontal state. During the process of the upper mold pressing down, as the V-shaped part bends downward, the two pins will gradually slide down along the guide surface and approach each other. During this process, the two guide surfaces can keep the two pins in a horizontal state. When the V-shaped part is close to bending downward, the two pins will be embedded in the corresponding engagement grooves until the V-shaped part is completely bent downward. At this time, the two engagement grooves can limit the two pins and prevent them from bending outward in a figure-eight shape under stress. That is, the engagement grooves can keep the pins in a straight state.

[0026] Furthermore, a stop bar is provided at the lower end of the guide surface, distributed in the front-rear direction. When the upper mold moves down to the limit position, the engagement groove and the stop bar form a channel between the mating surface and the guide surface for the corresponding PIN to pass through.

[0027] The beneficial effect of the above-mentioned further technical solution is that when the V-shaped part bends downward into place, the channel can limit and shape the PIN.

[0028] Furthermore, when the upper mold moves down to its limit position, the distance between the engagement groove and the abutment bar on both sides oppositely distributed along the guide surface is L1, and the width of the PIN foot is L2, wherein L1 > L2.

[0029] The beneficial effect of the above-mentioned further technical solution is that: when the V-shaped part bends downward, the PIN will also rotate to a certain extent in the circumferential direction. By designing L1 to be greater than L2, the size of the channel is slightly larger than the outer size of the PIN, thus leaving a certain space for the rotation of the PIN and avoiding the PIN from being stuck at this point and interfering with the hairpin wire production mold.

[0030] Furthermore, each of the two lower support blocks has a guide male portion on one side away from each other at its upper end, and the lower end of the upper pressure block has a guide female portion that mates with the corresponding guide male portion. The guide male portion and the corresponding guide female portion are connected or in contact with each other for guidance.

[0031] The beneficial effect of the above-mentioned further technical solution is that when the upper pressure block moves up and down with the upper mold, the guide male and guide female parts cooperate to maintain vertically stable sliding.

[0032] Furthermore, the male guide portion is a groove or a recessed hole, the female guide portion is a protruding post, and the sides of the two female guide portions that are close to each other are inclined extrusion surfaces, and the inclination direction of the extrusion surfaces is different from that of the mating surfaces on the same side.

[0033] The beneficial effects of the above-mentioned further technical solution are as follows: it makes the structure of the guide male and guide female simple and the fit better, and the extrusion surface enables the two guide females to extrude the two pins to move downward along the guide surface and gather together as the upper mold moves downward. Attached Figure Description

[0034] Figure 1 An elevation view of the target hairpin wire in the prior art;

[0035] Figure 2 This is a front view of the target hairpin wire in the prior art;

[0036] Figure 3 This is a side view of the target hairpin wire in the prior art;

[0037] Figure 4 This is a comparison diagram of the pre-rebound hairpin wire and the target hairpin wire described in Embodiment 1 of the present invention;

[0038] Figure 5 This is a front elevation view of the hairpin wire production mold described in Embodiment 2 of the present invention;

[0039] Figure 6 This is a top view of the hairpin wire blank in Embodiment 2 of the present invention;

[0040] Figure 7 This is a rear elevation view of the hairpin wire production mold described in Embodiment 2 of the present invention;

[0041] Figure 8 This is an assembly diagram of the lower mold, guide post, lower support block, and mounting base as described in Embodiment 2 of the present invention;

[0042] Figure 9 for Figure 8 Rear elevation view when the rear limit block is removed;

[0043] Figure 10 This is an assembly diagram of the upper mold and upper pressure block as described in Embodiment 2 of the present invention;

[0044] Figure 11 This is a bottom view of the assembly of the upper mold and the upper pressure block as described in Embodiment 2 of the present invention;

[0045] Figure 12 This is a front view of the upper and lower molds when they are closed in Embodiment 2 of the present invention;

[0046] Figure 13 for Figure 12 Enlarged view of point A in the middle;

[0047] Figure 14 This is a schematic diagram of the test indicators of the target hairpin wire produced by the hairpin wire production mold provided in Embodiment 2 of the present invention.

[0048] In the diagram: 1a, target hairpin wire; 1b, hairpin wire before rebound; 1c, hairpin wire blank; 11, V-shaped part; 111, twisting part; 12, PIN foot; 2, lower mold; 21, cavity; 22, recessed area; 221, slope; 222, protruding ridge; 23, rear limit block; 24, front limit block; 241, supporting surface; 3, upper mold; 31, guide hole; 32, punch; 33, clearance groove; 4, guide post; 5, lower support block; 51, guide surface; 52, stop bar; 53, guide male part; 6, upper pressure block; 61, mating surface; 62, engagement groove; 63, guide female part; 631, extrusion surface; 7, mounting base. Detailed Implementation

[0049] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0051] It is understood that spatial relation terms such as “below,” “under,” “below,” “below,” “above,” “above,” etc., can be used here to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “below,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0052] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. In the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have the transmission of electrical signals or data between them.

[0053] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0054] Example 1

[0055] like Figure 4 As shown, this embodiment provides a method for designing a mold for producing hairpin wires, including the following steps:

[0056] Step 1: Construct a 3D model of the target hairpin wire 1a in the 3D model, and obtain the central axis of the target hairpin wire 1a from the 3D model;

[0057] Step 2: Calculate the springback compensation value of the target hairpin wire 1a, and reconstruct the 3D model of the hairpin wire 1b before springback in the 3D model based on the springback compensation value;

[0058] Step 3: Construct a hairpin wire production mold based on the 3D model of the hairpin wire 1b before springback. By incorporating the springback compensation value into the mold design, the hairpin wire 1b produced by the mold will spring back automatically after being removed from the mold, thus obtaining the target hairpin wire 1a.

[0059] The method for calculating the rebound compensation value in step 2 of this embodiment is as follows:

[0060] In the 3D model, the distance W between the centers of the two pins of the target hairpin wire 1a and the height H of the tip of the target hairpin wire 1a are measured respectively.

[0061] The displacement compensation value of the target hairpin wire 1a is h=W / m, where m=100 (m is an empirical value); the single-sided angle compensation value of the center line of the target hairpin wire 1a is β=arctan((H+h) / 0.5W)-arctan(H / 0.5W);

[0062] The displacement compensation value h and the single-sided angle compensation value β are the springback compensation values. In this way, the displacement compensation value h can compensate for the shortening of the vertical distance between the torsion part 111 and the plane where the two pins 12 are located, while the single-sided angle compensation value β can compensate for the increase in the angle between the pin 12 and the V-shaped part 11 at the connection point in the lateral projection plane after springback.

[0063] In this embodiment, a target hairpin wire 1a is used as an example for description. The target hairpin wire 1a has W=40.3mm, H=3.1mm, displacement compensation value h=W / 100=40.3 / 100=0.403mm, and single-sided angle compensation value β=arctan((H+h) / 0.5W)-arctan(H / 0.5W)=1.2°.

[0064] Figure 4 The length of the median segment AA is W, the length between segments BC1 is H, the length between segments BC2 is h, and the angle between the two ∠C1AC2 is β.

[0065] The 3D modeling software described in this embodiment can be SolidWorks or CATIA, but it is not limited to these.

[0066] The hairpin wire production mold described in this embodiment is designed according to the shape of the hairpin wire 1b before springback.

[0067] Example 2

[0068] like Figures 5-7As shown, this embodiment provides a hair clip wire production mold, which is manufactured according to the hair clip wire production mold design method described in Embodiment 1. It includes a lower mold 2, an upper mold 3, and guide pillars 4. The lower mold 2 and the upper mold 3 are both horizontally arranged in the left-right direction. The middle of the upper end of the lower mold 2 is recessed with a cavity 21. Two guide pillars 4 are provided, which are respectively vertically arranged at both ends of the lower mold 2. Both ends of the upper mold 3 are provided with vertically penetrating guide holes 31. Each guide pillar 4 passes through the corresponding guide hole 31. The middle of the lower end of the upper mold 3 is provided with a punch 32 that cooperates with the cavity 21. The hair clip wire blank 1c is placed horizontally on the lower mold 2 in the front-back direction, and the V-shaped part 11 is suspended in the cavity 21. The open end of the hair clip wire blank 1c faces forward. The upper mold 3 moves downward under the action of external force to press the hair clip wire blank 1c down to form the springback front hair clip wire 1b. This allows the hair clip wire blank 1c to be placed horizontally on the lower mold 2 in the front-to-back direction, with the pins 12 all facing forward, and the V-shaped part 11 located above the cavity 21. At this time, when the upper mold 3 is pressed down, the punch 32 can cooperate with the cavity 21 to press the V-shaped part 11 down to bend downward relative to the pins 12, so as to obtain the hair clip wire 1b before springback. When the upper mold 3 moves upward to reset, the hair clip wire 1b before springback will have its V-shaped part 11 slightly spring back upward relative to the pins 12 under its own stress, thus obtaining the target hair clip wire 1a.

[0069] like Figure 5 and Figure 7 As shown, in this embodiment, the guide post 4 cooperates with the guide hole 31. Preferably, the guide post 4 is a cylinder, and the guide hole 31 is a circular hole. The diameter of the guide post 4 is similar to the diameter of the guide hole 31, ensuring that after the guide post 4 passes through the corresponding guide hole 31, the upper mold 3 will not wobble during the up-and-down movement relative to the lower mold 2, thereby improving the accuracy of the forming of the hairpin wire 1b before the springback.

[0070] like Figure 8 and Figure 9As shown, in this embodiment, the lower mold 2 is recessed downward in the middle to form a recessed area 22. The walls on both sides of the recessed area 22 are slopes 221 that cooperate with the V-shaped part 11 in the middle of the springback hairpin wire 1b. A rear limiting block 23 is protruding in the middle of the rear end of the recessed area 22, and a front limiting block 24 is protruding in the middle of the front end of the recessed area 22. The rear side of the front limiting block 24 protrudes in an isosceles triangle to form a supporting surface 241. The supporting surface 241 cooperates with the inner side of the middle of the hairpin wire blank 1c. The recessed area 22 has a protruding ridge 222 in the middle between the rear limiting block 23 and the front limiting block 24 that cooperates with the torsion part 111. The front limiting block 24 and the rear limiting block 23 enclose the cavity 21 in the recessed area 22. This allows the front limiting block 24 and the rear limiting block 23 to clamp the tip of the V-shaped part 11 between them, while the supporting surface 241 fits against the inner side of the V-shaped part 11 to limit the two sides of the V-shaped part 11. This can prevent the V-shaped part 11 from deforming under the downward pressure of the upper mold 3, thus preventing the product from being defective.

[0071] like Figure 10 and Figure 11 As shown, in this embodiment, the center of the front side of the punch 32 is recessed rearward to form a relief groove 33 that cooperates with and fits against the supporting surface 241 (preferably, in this embodiment, the relief groove 33 can extend directly upward to penetrate the upper end of the upper die 3). This ensures that the V-shaped portion 11 is pressed precisely below the punch 32 and fits against the supporting surface 241, which facilitates the V-shaped portion 11 bending downward against the supporting surface 241 under the downward pressure of the upper die 3.

[0072] like Figure 5 , Figures 7-11As shown, in this embodiment, lower support blocks 5 are provided on both sides of the front end of the lower mold 2 corresponding to the slope 221, and upper pressure blocks 6 are provided on both sides of the front end of the upper mold 3. The two lower support blocks 5 correspond one-to-one with the two upper pressure blocks 6. The upper end of the lower support block 5 is an inclined guide surface 51, and the guide surface 51 is aligned with the corresponding part of the slope 221 on the same side. The lower end surface of the upper pressure block 6 is an inclined mating surface 61, and the mating surface 61 mates with the guide surface 51 on the same side. The lower end of the mating surface 61 is recessed with a meshing groove 62 distributed in the front-back direction. When the hair clip wire blank 1c is placed on the lower mold 2, the two pins 12 are supported on the two guide surfaces 51. When the upper mold 3 is pressed down under the action of external force, the V-shaped part 11 bends downward and drives the two pins 12 to slide closer to each other until the two pins 12 abut against the two meshing grooves 62. This allows the hair clip wire blank 1c to be placed on the lower mold 2, so that the connection between the two pins 12 and the V-shaped part 11 can be supported by the two lower support blocks 5, and the V-shaped part 11 is embedded between the front limit block 24 and the rear limit block 23. At this time, the hair clip wire blank 1c can remain stable in a horizontal state. During the pressing down of the upper mold 3, as the V-shaped part 11 bends downward, the two pins 12 will gradually slide down along the guide surface 51 and move closer to each other. During this process, the two guide surfaces 51 can keep the two pins 12 in a horizontal state. When the V-shaped part 11 is close to bending downward, the two pins 12 will be embedded in the corresponding engagement groove 62 until the V-shaped part 11 is completely bent downward. At this time, the two engagement grooves 62 can limit the two pins 12, preventing them from bending outward in a "V" shape under stress. That is, the engagement grooves 62 can keep the pins 12 in a straight state.

[0073] like Figure 5 , Figure 8 and Figure 9 As shown, in this embodiment, a stop bar 52 distributed in the front-to-back direction is protruding from the lower end of the guide surface 51. When the upper mold 3 moves down to its limit position, the engagement groove 62 and the stop bar 52 enclose a channel between the mating surface 61 and the guide surface 51 for the corresponding PIN foot 12 to pass through. This allows the channel to limit and shape the PIN foot 12 when the V-shaped portion 11 bends downward.

[0074] like Figure 12 and Figure 13As shown, in this embodiment, when the upper mold 3 moves down to its limit position, the distance between the two sides of the engagement groove 62 and the stop bar 52 distributed opposite to each other along the guide surface 51 is L1, and the width of the PIN 12 is L2, where L1 > L2. Since the PIN 12 will also rotate to a certain extent in the circumferential direction when the V-shaped part 11 bends downward, by designing L1 to be greater than L2, the size of the channel is slightly larger than the outer size of the PIN 12, thereby reserving a certain space margin for the rotation of the PIN 12 and avoiding the PIN 12 from getting stuck at this point and interfering with the hairpin wire production mold.

[0075] Specifically, if L1 is about 1mm larger than L2, the channel can accommodate a slight rotation of PIN 12.

[0076] like Figures 8-10 As shown, in this embodiment, each of the two lower support blocks 5 has a guide male portion 53 on one side of its upper end that is far apart from each other. The lower end of the upper pressure block 6 has a guide female portion 63 that cooperates with the corresponding guide male portion 53. The guide male portion 53 and the corresponding guide female portion 63 are connected or in contact with each other for guidance. This allows the upper pressure block 6 to maintain vertically stable sliding by the cooperation of the guide male portion 53 and the guide female portion 63 when it moves up and down with the upper mold 3.

[0077] like Figures 8-10 As shown, in this embodiment, the guide male part 53 is a groove or a concave hole, and the guide female part 63 is a protruding post; at this time, the two guide female parts 63 are inclined extrusion surfaces 631 on the side that are close to each other, and the inclination direction of the extrusion surface 631 is different from that of the mating surface 61 on the same side. This allows the two guide female parts 63 to be squeezed by the two extrusion surfaces 631 to move downward along the guide surface 51 and converge as the two guide female parts 63 move downward with the upper mold 3.

[0078] like Figure 5 , Figures 7-9 and Figure 12 As shown, the hairpin wire production mold in this embodiment also includes a mounting base 7, which is horizontally arranged, and the lower mold 2 is horizontally installed in the middle of the upper end of the mounting base 7.

[0079] like Figure 14 As shown in the table below, the target hairpin wire 1a produced by the hairpin wire production mold of this embodiment meets the design requirements, and the bending angle and surface dimensions at each bend are qualified.

[0080]

[0081] Where LA and LB represent the side lengths of each side at the cross-section of the left PIN 12, RA and RB represent the side lengths of each side at the cross-section of the left PIN 12, angle δ represents the included angle between the two sides of the V-shaped part 11, and center spacing d represents the spacing between the two PIN 12 axes.

[0082] Based on this, it can be determined that the hairpin wire production mold designed using the hairpin wire production mold design method provided in this embodiment 1 is qualified, and the target hairpin wire 1a obtained after the hairpin wire 1b prepared by it rebounds on its own also meets the requirements.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A mold for producing hair clip wires, characterized in that, The system includes a lower mold (2), an upper mold (3), and guide pillars (4). Both the lower mold (2) and the upper mold (3) are horizontally arranged in the left-right direction. The lower mold (2) has a cavity (21) recessed in the middle of its upper end. There are two guide pillars (4), which are vertically arranged at both ends of the lower mold (2). Both ends of the upper mold (3) are provided with vertically penetrating guide holes (31). Each guide pillar (4) passes through the corresponding guide hole. Hole (31), the upper mold (3) has a protruding punch (32) at the middle of the lower end that cooperates with the cavity (21). The hair clip wire blank (1c) is placed horizontally on the lower mold (2) in the front-back direction, and the V-shaped part (11) is suspended in the cavity (21). The open end of the hair clip wire blank (1c) faces forward. The upper mold (3) moves downward under the action of external force to press down the hair clip wire blank (1c) to form a springback front hair clip wire (1b). The lower mold (2) is recessed downward in the middle to form a recessed area (22). The walls on both sides of the recessed area (22) are slopes (221) that cooperate with the V-shaped part (11) in the middle of the springback hairpin wire (1b). A rear limiting block (23) is protruding in the middle of the rear end of the recessed area (22), and a front limiting block (24) is protruding in the middle of the front end of the recessed area (22). The rear side of the front limiting block (24) is an isosceles triangle. The protruding part forms a supporting surface (241), which matches the inner side of the middle part of the hairpin wire blank (1c). The recessed area (22) has a protruding ridge (222) that matches the torsion part (111) in the middle part between the rear limiting block (23) and the front limiting block (24). The front limiting block (24) and the rear limiting block (23) enclose the cavity (21) in the recessed area (22).

2. The hair clip wire production mold according to claim 1, characterized in that, The punch (32) has a recessed groove (33) on the front side of the middle, which is recessed to the rear and fits with the supporting surface (241).

3. The hair clip wire production mold according to claim 1, characterized in that, Lower support blocks (5) are provided on both sides of the front end of the lower mold (2) corresponding to the slope (221). Upper pressure blocks (6) are provided on both sides of the front end of the upper mold (3). The two lower support blocks (5) correspond one-to-one with the two upper pressure blocks (6). The upper end of the lower support block (5) is an inclined guide surface (51), and the guide surface (51) is aligned with the corresponding part of the slope (221) on the same side. The lower end of the upper pressure block (6) is an inclined mating surface (61), and the mating surface (61) is aligned with the corresponding part of the slope (221) on the same side. The guide surface (51) is fitted, and the lower end of the mating surface (61) is recessed with a meshing groove (62) distributed in the front-back direction. When the hair clip wire blank (1c) is placed on the lower mold (2), the two pins (12) are supported on the two guide surfaces (51). When the upper mold (3) is pressed down under the action of external force, the V-shaped part (11) bends downward and drives the two pins (12) to slide close to each other until the two pins (12) abut against the two meshing grooves (62).

4. The hair clip wire production mold according to claim 1, characterized in that, The guide surface (51) has a protruding abutment strip (52) distributed in the front-back direction at the lower end. When the upper mold (3) moves down to the limit position, the engagement groove (62) and the abutment strip (52) enclose the mating surface (61) and the guide surface (51) to form a channel for the corresponding PIN foot (12) to pass through.

5. The hair clip wire production mold according to claim 4, characterized in that, When the upper mold (3) moves down to the limit position, the distance between the two sides of the engagement groove (62) and the stop bar (52) distributed opposite to each other along the guide surface (51) is L1, and the width of the PIN foot (12) is L2, wherein L1 is greater than L2.

6. The hair clip wire production mold according to any one of claims 3-5, characterized in that, The two lower support blocks (5) are provided with guide male parts (53) on the side of their upper ends that are far apart from each other. The lower end of the upper pressure block (6) is provided with a guide female part (63) that cooperates with the corresponding guide male part (53). The guide male part (53) and the corresponding guide female part (63) are connected or in contact with each other for guidance.

7. The hair clip wire production mold according to claim 6, characterized in that, The male guide (53) is a groove or a recess, and the female guide (63) is a protruding post. The two female guides (63) are inclined extrusion surfaces (631) on the side that are close to each other, and the extrusion surfaces (631) are in different inclination directions from the mating surfaces (61) on the same side.

8. A design method for a hair clip wire production mold as described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Construct a 3D model of the target hairpin wire (1a) in the 3D model, and obtain the central axis of the target hairpin wire (1a) from the 3D model; Step 2: Calculate the rebound compensation value of the target hairpin wire (1a), and reconstruct the three-dimensional model of the hairpin wire (1b) before rebound in the three-dimensional model based on the rebound compensation value; Step 3: Construct the hairpin wire production mold in the 3D model based on the 3D model drawing of the hairpin wire (1b) before springback.

9. The design method for a hair clip wire production mold according to claim 8, characterized in that, The method for calculating the rebound compensation value in step 2 is as follows: In the 3D model, the distance W between the centers of the two pins of the target hairpin wire (1a) and the height H of the tip of the target hairpin wire (1a) are measured respectively. The displacement compensation value of the target hairpin wire (1a) is h=W / m, where m=100; the single-sided angle compensation value of the center line of the target hairpin wire (1a) is β=arctan((H+h) / 0.5W)-arctan(H / 0.5W); The displacement compensation value h and the single-sided angle compensation value β are the rebound compensation values.

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