A double-ended stud cold heading die and forming method

Abstract

This invention provides a cold heading mold and forming method for double-ended studs. The cold heading mold includes a feeding mechanism, a straightening mechanism, a cutting mechanism, a cold heading mechanism, and a threading mechanism. Multiple feeding mechanisms are used to convey the double-ended studs during the forming process. The straightening mechanism applies pressure to the blank to straighten it. The cutting mechanism has a grinding wheel at its front end for cleaning the surface of the blank and cutting the blank. The cold heading mechanism includes a main mold and a punch, with the punch located directly above the main mold. The main mold has a main mold cavity and an ejector pin, the main mold cavity being shaped like one end of the double-ended stud. The upper end of the ejector pin has an inner chamfer, and the lower end of the punch has an ejector pin. The threading mechanism is used to thread the blank after cold heading. Compared with existing technologies, this solution achieves the entire process of processing double-ended studs from wire to finished product through the cooperation of the cutting mechanism, cold heading mechanism, and threading mechanism; it eliminates chamfering and forging processes, greatly improving the processing efficiency of double-ended studs.

Description

Technical Field

[0001] This invention relates to the field of bolt manufacturing technology, and in particular to a cold heading die and forming method for a double-ended stud. Background Technology

[0002] A double-end stud is a cylindrical fastener with threads at both ends. It is widely used in power, chemical, oil refining, valve, railway, bridge, steel structure, automotive parts, machinery, boiler steel structures, cranes, large-span steel structures, and large buildings.

[0003] Double-ended stud blanks are typically machined by cutting or cold heading. Cold heading technology is preferred due to its high steel utilization, high productivity, and ease of automation. After cold heading, the blank needs to be chamfered or forged. Forging can easily lead to deformation and defects such as incomplete diagonal alignment at both ends. Furthermore, straightening and end-face machining are required before thread rolling or turning. The entire production process of double-ended studs is time-consuming, reducing processing efficiency. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a cold heading mold and forming method for double-ended studs, so as to solve the problems of low processing efficiency and defects of double-ended studs in the prior art.

[0005] To achieve the above and other related objectives, the present invention provides a double-ended stud cold heading die and a forming method, comprising:

[0006] The working principle of this basic scheme is as follows: First, the wire is straightened by a straightening mechanism before being cut into blanks, with pressure applied from both sides during the straightening process. Then, the wire is conveyed to a cutting mechanism, where a grinding wheel at the front end of the cutting mechanism grinds and cleans the surface of the wire. After grinding, a blank is cut according to the material required for one double-ended stud. The cut blank is placed into the main mold cavity, where it is cold-forged by a die, forming a first rod and a first chamfer at one end. The blank is then flipped over, and the other end is placed into the main mold cavity for cold forging, forming a second rod and a second chamfer at the other end. Finally, the first and second rods are threaded by a threading mechanism to obtain the double-ended stud. During the double-ended stud forming process, the blank can be transferred between the various mechanisms via a feeding mechanism.

[0007] The beneficial effects of this basic scheme are as follows:

[0008] 1. In this solution, the two ends of the blank are cold-forged separately by a cold-forging mechanism. During the cold-forging process, the chamfers at both ends of the double-ended stud can be directly formed by the inner chamfer of the ejector pin. Since the blank has been straightened beforehand, and the cold-forging mechanism will not deform the blank or cause defects such as incomplete diagonal sections during the cold-forging process, there is no need for subsequent straightening and end-face machining processes, which greatly reduces the production steps in the double-ended stud forming process and greatly improves processing efficiency.

[0009] 2. This solution utilizes multiple feeding mechanisms to transfer the blank between processes, which reduces the transfer time of the double-ended stud during the forming process, avoids excessive time consumption, and further improves the processing efficiency of the double-ended stud.

[0010] 3. In this solution, the two ends of the double-ended stud are threaded by a threading mechanism. During the threading process, the length of the threads can be equal or not, and the thread directions can be the same or opposite, which can process double-ended studs with different requirements.

[0011] Compared with existing technologies, the cold heading mold in this solution, through the cooperation of the cutting mechanism, cold heading mechanism, and thread turning mechanism, realizes the whole process of processing double-ended studs from wire to finished product; in particular, the cold heading mechanism realizes the cold heading and chamfering of both ends of the blank, eliminating the chamfering and forging processes, and greatly improving the processing efficiency of double-ended studs.

[0012] Furthermore, the main mold includes a main mold shell and a main mold core from the outside to the inside. A main mold pad is provided below the main mold core. The main mold core is the main mold cavity. The ejector rod can move up and down in the main mold cavity, and when the ejector rod stops moving, it forms an interference fit with the main mold cavity.

[0013] Beneficial effects: The arrangement of the main mold core and the main mold pad makes the main mold cavity more stable, and the movement of the ejector pin can adjust the length of the threads at both ends of the blank, making the mold more widely applicable.

[0014] Furthermore, the die includes a die shell, and a die pad is provided inside the die shell, with the ejector pin located at the lower end of the die pad.

[0015] Beneficial effects: The cooperation between the die shell and the die pad allows the ejector pin to be more stably aligned with the main die cavity to perform the stamping action on the blank.

[0016] Furthermore, the cold heading mechanism consists of two parts, arranged side by side, with a turning component for turning the blank between the two cold heading mechanisms.

[0017] Beneficial effects: This solution requires cold heading of both ends of the blank separately. During the process, the blank is flipped and conveyed by a flipping component. Using two cold heading mechanisms can streamline the cold heading process of the double-ended stud, further improving the production efficiency of the double-ended stud.

[0018] Furthermore, the flipping component includes a supporting side plate, a floating plate, and a clamping block. The floating plate is located between the supporting side plate and the clamping block. One end of the supporting side plate is provided with a connecting block, and one end of the floating plate is rotatably connected to the connecting block. The supporting side plate is provided with a horizontally movable slider. The floating plate is provided with a horizontally arranged strip hole. The middle of the strip hole is a semi-circular structure that bulges upward. A pin is provided at the lower end of the semi-circular structure on the floating plate. The clamping block is provided with a sliding groove, and the pin is slidably connected to the sliding groove. A support column is provided on the slider. The support column passes through the strip hole and is connected to the clamping block. One side of the clamping block is provided with a jaw for clamping a double-ended stud.

[0019] Beneficial effects: During use, the flipping component slides a slider horizontally, which in turn drives the support column and clamping block to slide horizontally as well. Since the support column passes through the slotted hole, it must slide horizontally along the slotted hole. Simultaneously, the groove on the clamping block engages with the pin. When the support column passes through the semi-circular slotted hole, the groove and pin allow the clamping block to flip 180°. During this process, the gripper on one side of the clamping block can hold the blank on one side of the cold heading mechanism, flip it 180°, and then place it into the main mold cavity of the other cold heading mechanism. This design of the flipping component is simple in structure, and allows for fast and precise flipping and transfer of blanks, further increasing the production efficiency of double-ended studs.

[0020] Furthermore, a cylinder is provided on the support side plate, and the cylinder is connected to the slider to drive the slider to slide horizontally.

[0021] Beneficial effects: By controlling the slider to slide horizontally with a cylinder, the use of the flipping parts can be automated, and the flipping of the blank can be more precise.

[0022] Furthermore, one end of the support column is slidably connected to the slider via a bearing, and the other end of the support column is fixedly connected to the clamping block.

[0023] Beneficial effect: During the horizontal movement of the support column, the clamping block will rotate 180°, and the support column is set in this way to make the rotation of the clamping block smoother.

[0024] Furthermore, the straightening mechanism employs multiple sets of opposing concave cams. Each concave cam includes a central concave wheel and cams positioned on either side of the concave wheel. The positions of the two cams relative to the concave wheel are adjustable.

[0025] Beneficial effects: The setting of multiple sets of concave cams facilitates the application of pressure to the blank wire and straightening. The cooperation between the concave wheel and the cam adjusts the magnitude of the pressure applied to the wire and the clamping position, making the straightening mechanism suitable for straightening wires of different diameters.

[0026] Furthermore, the thread-cutting mechanism is mounted on a support, and the support is equipped with pulleys, which are used to control the thread-cutting mechanism to move up and down along the support.

[0027] Beneficial effect: The threading mechanism can slide vertically through pulleys to complete the threading of both ends of the double-ended stud.

[0028] Accordingly, the present invention also provides a method for forming a double-ended stud, further comprising any of the above-mentioned methods, wherein the double-ended stud cold heading die, the forming method includes:

[0029] Straightening is performed by applying pressure to the blank wire using the straightening mechanism.

[0030] Cutting: The surface of the blank wire is polished and impurities are removed by a grinding wheel. The required length of blank is cut from the blank wire by the cutting mechanism according to the material amount of the double-ended stud.

[0031] Cold heading involves placing one end of the blank into the main mold cavity and cold heading it using the die to form a first rod and a first chamfer at one end. The blank is then flipped over and placed into the main mold cavity for cold heading, forming a second rod and a second chamfer at the other end.

[0032] Threading is performed on the first and second rod portions to obtain a double-ended stud.

[0033] The blank is conveyed using the feeding mechanism during the straightening, cutting, and threading processes.

[0034] The beneficial effects of a double-ended stud forming method are as follows: This forming method optimizes the manufacturing process of double-ended studs. The blank is directly formed through cold heading, eliminating the steps of chamfering and forging. This forming method can achieve equal or unequal lengths of the threads at both ends of the double-ended stud, as well as processing the threads at both ends in the same or opposite directions, greatly improving the processing efficiency of double-ended studs and significantly increasing the production efficiency of irregular nuts, effectively reducing production time. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of a double-headed stud cold heading die according to an example of the present invention;

[0036] Figure 2 This is a schematic diagram illustrating the changes in the blank during the forming process of a double-ended stud, as exemplified by the present invention.

[0037] Figure 3 This is a schematic diagram of the cold heading mechanism in a double-headed stud cold heading die according to an example of the present invention;

[0038] Figure 4 This is a top view of the concave cam in a straightening mechanism of a double-headed stud cold heading die according to an example of the present invention;

[0039] Figure 5 This is a schematic diagram of the structure of a flipping component in a double-headed stud cold heading mold, as an example of the present invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] Feeding mechanism 10

[0042] Straightening structure 20, concave cam 21, concave wheel 22, cam 23,

[0043] Cutting mechanism 30, grinding wheel 31

[0044] Cold heading mechanism 40, main mold 41, main mold shell 411, main mold core 412, main mold pad 413, main mold cavity 414, ejector pin 415, inner chamfer 416, punch 42, punch shell 421, punch pad 422, ejector pin 423.

[0045] The components include: a flipping mechanism 50, a supporting side plate 51, a slider 52, a slide rail 521, a support column 53, a cylinder 54, a connecting block 55, a float plate 56, a slotted hole 561, a pin 562, a clamping block 57, a gripper 581, and a slide groove 582.

[0046] 60, thread-cutting mechanism, 61, bracket, 62,

[0047] Wire 71, blank 72, first rod 721, first chamfer 722, second rod 723, second chamfer 724, double-ended stud 73. Detailed Implementation

[0048] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0049] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show components relevant to the present invention and are not drawn according to the actual number, shape, and size of components in implementation. In actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the component layout may be more complex. The structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives of the present invention, should still fall within the scope of the technical content disclosed in the present invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are only for clarity of description and are not intended to limit the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0050] Before describing the embodiments of the present invention in detail, the application environment of the present invention will be described first. The technology of the present invention is mainly applied to the manufacturing process of double-ended studs.

[0051] The specific structure of the double-headed stud 73 cold heading mold and forming method in this invention is described in conjunction with the following: Figures 1 to 5 The mold includes:

[0052] Feeding mechanism 10, wherein there are multiple feeding mechanisms 10, used to convey the double-headed studs 73 during the molding process;

[0053] A straightening mechanism, which is used to apply pressure to the blank 72 to straighten it;

[0054] The cutting mechanism 30 has a grinding wheel 31 at its front end. The grinding wheel 31 is used to remove the surface of the blank 72. The cutting mechanism cuts the blank 72.

[0055] The cold heading mechanism 40 includes a main mold 41 and a punch 42. The punch 42 is located directly above the main mold 41. The main mold 41 has a main mold cavity 414 and an ejector pin 415. The main mold cavity 414 is shaped like one end of a double-ended stud 73. The upper end of the ejector pin 415 is provided with an inner chamfer 416. The lower end of the punch 42 is provided with an ejector pin 423.

[0056] The threading mechanism 60 is used to thread the blank 72 after cold heading.

[0057] Multiple feeding mechanisms are respectively located outside the straightening mechanism, the cutting mechanism, and the threading mechanism 60. The feeding mechanism 10 can be a conveying mechanism capable of conveying wire 71 in the prior art, and the threading mechanism 60 can be a threading mechanism capable of threading cylindrical structures in the prior art.

[0058] In this scheme, the device first straightens the wire 71 before it is cut into blank 72 by a straightening mechanism. During the straightening process, pressure is applied from both sides of the wire 71. Then, the wire 71 is conveyed to the cutting mechanism 30. The surface of the wire 71 is polished and cleaned by the grinding wheel 31 at the front end of the cutting mechanism 30 to remove rust, dust and impurities from the surface of the wire 71. After polishing, a blank 72 is cut according to the material required for a double-ended stud 73. The cut blank 72 is placed into the main mold cavity 414, and the blank 72 is cold-forged by the punch 42 to form a first rod 721 and a first chamfer 722 at one end of the blank 72. The blank 72 is then flipped over and the other end of the blank 72 is placed into the main mold cavity 414 for cold forging to form a second rod 723 and a second chamfer 724 at the other end of the blank 72. Then, the first rod 721 and the second rod 723 are threaded by the threading mechanism to obtain a double-ended stud 73. During the forming process of the double-ended stud 73, the blank 72 can be transferred between various mechanisms by the feeding mechanism 10.

[0059] In some implementations, the main mold 41 includes, from the outside in, a main mold shell 411 and a main mold core 412. A main mold pad 413 is provided below the main mold core 412. The interior of the main mold core 412 is the main mold cavity 414. The ejector rod 415 can move up and down within the main mold cavity 414, and when the ejector rod 415 stops moving, it forms an interference fit with the main mold cavity 414. For example, Figure 3 As shown, the arrangement of the main mold core 412 and the main mold pad 413 makes the main mold cavity 414 more stable, and the movement of the ejector pin 415 can adjust the length of the threads at both ends of the blank 72, making the mold more widely applicable.

[0060] In some implementations, the die 42 includes a die shell 421, and a die pad 422 is provided inside the die shell 421. The ejector pin 423 is located at the lower end of the die pad 422. For example, Figure 3 As shown, through the cooperation of the die shell 421 and the die pad 422, the ejector pin 423 can be more stably aligned with the main die cavity 414 to perform the stamping action on the blank 72. In order to facilitate the lower end of the ejector pin 423 to not affect the first chamfer 722 that has been stamped by the die 42 when it is stamped again, the lower end of the ejector pin 423 is provided with a corresponding inner chamfer 416. During the cold heading process of the second rod 723 and the second chamfer 724, the inner chamfer 416 will protect the first inner chamfer 416 that has been cold headed.

[0061] In some implementations, the cold heading mechanism 40 is structured as two units, arranged side by side, with a turning component between them for turning the blank 72. For example, Figure 1 As shown, in this scheme, the two ends of the blank 72 need to be cold-forged separately. In the production process of a double-ended stud 73, the cold-forging mechanism 40 needs to be used twice. Therefore, setting two cold-forging mechanisms 40 can speed up the production process of the double-ended stud 73. After the blank 72 is cold-forged into the first rod 721 and the first chamfer 722 in the first cold-forging mechanism 40, the blank 72 is removed by the flipping component and flipped 180°. The flipped blank 72 is then placed in the second cold-forging mechanism 40. The flipping component flips and conveys the blank 72, further improving the production efficiency of the double-ended stud 73.

[0062] In some implementations, the flipping component includes a supporting side plate 51, a float plate 56, and a clamping block 57. The float plate 56 is located between the supporting side plate 51 and the clamping block 57. One end of the supporting side plate 51 is provided with a connecting block 55, and one end of the float plate 56 is rotatably connected to the connecting block 55. The supporting side plate 51 is provided with a horizontally movable slider 52. The float plate 56 is provided with a horizontally arranged strip hole 561. The middle part of the strip hole 561 is a semi-circular structure that bulges upward. A pin 562 is provided at the lower end of the semi-circular structure on the float plate 56. The clamping block 57 is provided with a sliding groove 582, and the pin 562 is slidably connected to the sliding groove 582. A support column 53 is provided on the slider 52. The support column 53 passes through the strip hole 561 and is connected to the clamping block 57. One side of the clamping block 57 is provided with a jaw 581 for clamping a double-headed stud 73.

[0063] Specifically, such as Figure 5 As shown, a slide rail 521 is provided on the support side plate 51, and the slider 52 slides in conjunction with the slide rail 521 to achieve horizontal sliding of the slider 52. The lengths of the slide rail 521 and the strip hole 561 are basically consistent. The slide groove 582 and the gripper 581 are located on both sides of the clamping block 57, and the connecting block 55 is provided on one side of the float plate 56. In order to reduce the resistance of the support column 53 sliding in the strip hole 561, an elastic structure can be provided on the connecting block 55 so that the float block always remains in the horizontal direction, but under the action of force, the float block can also rotate along the connecting block 55.

[0064] In the specific implementation process, such as Figure 5As shown, during use, the flipping component reciprocates the sliding block 52 in the horizontal direction, which drives the support column 53 and the clamping block 57 to slide in the horizontal direction. Since the support column 53 passes through the slot 561, the support column 53 needs to slide horizontally along the slot 561. When the support column 53 slides to the semi-circular structure in the middle of the slot 561, in order to continue sliding with the sliding block 52, the support column 53 will interact with the slot 561 of the semi-circular structure, causing the float to rotate downward. After the support column 53 passes through the slot 561 of the semi-circular structure, the float rotates back to the horizontal position. During the above process, the sliding groove 582 on the clamping block 57 and the pin 562 are always in sliding engagement. When the support column 53 makes the semi-circular strip hole 561, in order to keep the pin 562 in the sliding groove 582, the clamping block 57 must rotate around the pin 562. Since the semi-circular strip hole 561 has 180°, when the support column 53 passes through the semi-circular strip hole 561, the clamping block 57 rotates 180° around the pin 562. During this process, the jaw 581 on one side of the clamping block 57 also rotates 180°.

[0065] In practical use, when the flipping mechanism 50 is in use, the slider 52 slides to the leftmost end, and the support rod and clamping block 57 move to the left end accordingly. The gripper 581 faces to the left and clamps the middle of the blank 72 on the left cold heading mechanism 40. Then the slider 52 slides to the right, and the support rod and clamping block 57 slide to the right accordingly. During this process, the clamping block 57 will rotate 180°, and the gripper 581 clamping the blank 72 will rotate 180° accordingly. When the slider 52 slides to the rightmost end, the support rod and clamping block 57 move to the right end accordingly. After flipping, the gripper 581 transfers the blank 72 to the right cold heading mechanism 40. Because the transfer of blank 72 has a flipping function, it is not just a simple horizontal transfer. During the flipping process, as long as the position of the gripper 581 is set properly, the blank 72 can be directly placed in the main mold cavity 414 of the right cold heading mechanism 40. Activating the right cold heading mechanism 40 can directly cold-forge the second rod 723 and the second chamfer 724. The flipping component is set in this way, which has a simple structure and allows for fast and accurate flipping and transfer of blank 72, which can further increase the production efficiency of double-ended studs 73.

[0066] In some implementations, a cylinder 54 is provided on the support side plate 51, and the cylinder 54 is connected to the slider 52 to drive the slider 52 to slide horizontally. For example, Figure 5 As shown, by controlling the slider 52 to slide in the horizontal direction through the cylinder 54, the use of the flipping component can be automated, and the flipping of the blank 72 can be more precise.

[0067] In some implementations, one end of the support column 53 is slidably connected to the slider 52 via a bearing, and the other end of the support column 53 is fixedly connected to the clamping block 57. For example, Figure 1As shown, during the horizontal movement of the support column 53, the clamping block 57 will rotate 180°. This arrangement of the support column 53 makes the rotation of the clamping block 57 smoother.

[0068] In some implementations, the straightening mechanism employs multiple sets of opposing concave cams 21. Each concave cam 21 includes a central concave wheel 22 and cams 23 positioned on either side of the concave wheel 22. The positions of the two cams 23 relative to the concave wheel 22 are adjustable. For example, Figure 4 As shown, this scheme has three sets of concave cams 21. The three sets of concave cams 21 apply pressure to the wire 71 on the same vertical line. During the vertical transmission of the wire 71, the wire 71 can be straightened vertically. The cooperation between the concave wheel 22 and the cam 23 adjusts the magnitude and clamping position of the pressure applied to the wire 71, making the straightening mechanism suitable for straightening wires 71 of different diameters.

[0069] In some implementations, the thread-cutting mechanism 60 is mounted on a support 61, and the support 61 is equipped with pulleys 62. The pulleys 62 are used to control the up-and-down movement of the thread-cutting mechanism 60 along the support 61. For example, Figure 1 As shown, the threading mechanism 60 can slide vertically via pulley 62, thereby completing the threading of both ends of the double-ended stud 73.

[0070] In some implementations, the present invention also provides a method for forming a double-ended stud 73, further comprising any of the above-mentioned methods, wherein the double-ended stud 73 cold heading die is used, and the forming method includes:

[0071] Straightening is performed by applying pressure to the blank 72 wire 71 using the straightening mechanism;

[0072] Cutting: The surface of the blank 72 wire 71 is polished and impurities are removed by the grinding wheel 31. According to the amount of material used for the double-headed stud 73, the blank 72 of the required length is cut from the blank 72 wire 71 by the cutting mechanism 30.

[0073] Cold heading: One end of the blank 72 is placed in the main mold cavity 414 and cold heading is performed on the blank 72 by the punch 42, so that one end of the blank 72 forms a first rod portion 721 and a first chamfer 722; the blank 72 is flipped over and the other end of the blank 72 is placed into the main mold cavity 414 for cold heading, so that the other end of the blank 72 forms a second rod portion 723 and a second chamfer 724;

[0074] The threading process is used to thread the first rod portion 721 and the second rod portion 723 to obtain a double-ended stud 73.

[0075] The blank 72 is conveyed by the feeding mechanism 10 during the straightening, cutting and threading processes.

[0076] Based on the above scheme, some corresponding processes can be added. Specifically, there are two cold heading mechanisms 40, and a flipping component is used between the two cold heading mechanisms to transfer and flip the blank 72; the threading mechanism 60 is controlled to move up and down by pulleys 62, which can realize the cold heading processing of both ends of the blank 72. The straightening mechanism, cutting mechanism, cold heading mechanism 40, flipping component, cold heading mechanism 40, and threading mechanism 60 are arranged in a reasonable sequence, and feeding mechanisms 10 are added before and after each process as needed. In this scheme, the production process of double-ended studs 73 can be automatically transferred. The power components used in each process can be controlled systematically according to the process, which can realize the automation of the production process of double-ended studs 73, improve the production efficiency of double-ended studs 73, and reduce manual intervention.

[0077] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A double-end stud cold heading die characterized by, The utility model relates to a double -end stud cold heading die and a double -end stud forming method, which comprises the following parts: a plurality of feeding mechanisms for conveying double-end studs in the forming process; a straightening mechanism for providing pressure to the blank wire to straighten it; a cutting mechanism, the front end of which is provided with a grinding wheel for grinding the surface of the blank wire, and the cutting mechanism cuts the blank wire; a cold heading mechanism, which comprises a main die and a punch, the punch is located directly above the main die, the main die has a main die cavity and a ejector rod inside, the main die cavity is shaped like one end of the double-end stud, the upper end of the ejector rod is provided with an internal chamfer, and the lower end of the punch is provided with a ejector pin inside; a threading mechanism for threading the blank after cold heading; the cold heading mechanism is provided with a turnover part for turning over the blank between the two cold heading mechanisms arranged side by side. The turnover part comprises a support side plate, a floating plate and a clamping block, the floating plate is located between the support side plate and the clamping block, one end of the support side plate is provided with a connecting block, and one end of the floating plate is rotationally connected with the connecting block; a horizontally movable sliding block is arranged on the support side plate, a horizontally arranged strip-shaped hole is arranged on the floating plate, the middle part of the strip-shaped hole is a semicircular structure that protrudes upward, a pin is arranged on the lower end of the semicircular structure of the floating plate, a sliding groove is arranged on the clamping block, and the pin and the sliding groove are slidably connected; a support column is arranged on the sliding block, the support column passes through the strip-shaped hole and is connected with the clamping block, and one side of the clamping block is provided with a clamping jaw for clamping the double-end stud. A cylinder is arranged on the support side plate and connected with the sliding block to drive the sliding block to slide horizontally.

2. A double-end stud cold heading die according to claim 1, characterized in that: The main die comprises a main die shell and a main die core from outside to inside, a main die pad is arranged below the main die core, the inside of the main die core is the main die cavity, the ejector rod can move up and down in the main die cavity, and the ejector rod forms an interference fit with the main die cavity when the ejector rod stops moving.

3. A double-end stud cold heading die according to claim 2, characterized in that: The punch comprises a punch shell, the inside of the punch shell is provided with a punch pad, and the ejector pin is located at the lower end of the punch pad.

4. A double-end stud cold heading die according to claim 3, characterized in that: One end of the support column is connected with the sliding block through a bearing, and the other end of the support column is fixedly connected with the clamping block.

5. A double-end stud cold heading die according to any one of claims 1-4, characterized in that: The straightening mechanism adopts a plurality of concave-convex wheels arranged oppositely, the concave-convex wheels comprise a concave wheel in the middle and two convex wheels arranged on both sides of the concave wheel, and the positions of the two convex wheels and the concave wheel can be adjusted.

6. A double-end stud cold heading die according to claim 5, characterized in that: The threading mechanism is arranged on a support, a pulley is arranged on the support, and the pulley is used to control the threading mechanism to move up and down along the support.

7. A method of forming a double-end stud, characterized by, The double-end stud cold heading die and the double-end stud forming method according to any one of claims 1-6, the forming method comprises the following steps: straightening, the straightening mechanism is used to apply pressure to the blank wire to straighten it; cutting, the surface of the blank wire is polished by the grinding wheel to remove impurities, and the cutting mechanism is used to cut the blank wire to the required length according to the material quantity of the double-end stud; The blank is put into a main die cavity at one end, cold heading is performed on the blank by the die to form a first rod part and a first chamfer at one end of the blank; the blank is turned over to put the other end of the blank into the main die cavity to perform cold heading, so that a second rod part and a second chamfer are formed at the other end of the blank; Tapping is performed on the first rod part and the second rod part by the tapping mechanism to obtain a double-end stud; In the processes of straightening, cutting and tapping, the feeding mechanism is used for conveying the blank.

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