Trimming die and method for bolt head

Abstract

The invention relates to the technical field of bolt machining, in particular to a trimming die and method for a bolt head, and the trimming die comprises a male die assembly and a female die assembly; the male die assembly comprises a male die sleeve and a trimming male die, and the trimming male die is assembled in a center hole in the right end of the male die sleeve. The female die assembly comprises a female die sleeve, and a trimming female die and a female die core are sequentially installed in a center hole of the female die sleeve from left to right. A female die ejector rod is mounted in a central through hole of the female die core; a stepped boss at the left end of the female die core extends into a stepped inner hole of the trimming female die; the caliber of the edge cutting female die cutting edge is larger than that of the edge cutting male die cutting edge, and the edge cutting male die and the edge cutting female die are oppositely arranged and jointly used for edge cutting of the head of a bolt product. The die can conduct bidirectional trimming on a bolt head, in the discharging process, when the female die ejector rod pushes a bolt product to retreat leftwards, the cut-in part of the trimming female die can be trimmed again by the cutting edge of the trimming male die, and the problem that the middle of the head is prone to being sunken due to traditional single trimming is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bolt processing, and particularly relates to a trimming die and method for a bolt head. BACKGROUND

[0002] Bolts are common fasteners, and the manufacturing process thereof usually includes cold upsetting forming and trimming. The blank formed after cold upsetting needs to be trimmed by a trimming die to remove the head flash, so as to form a regular bolt head shape, such as a hexagonal head, a quadrangular head, etc. In the prior art, the trimming die usually adopts a single trimming mode, that is, the trimming is completed by single-side shearing of the male die or the female die. This mode is still applicable to the bolt products with a thin head type, but for the products with a thick head type, due to the plastic deformation limit of the material, the problems such as the middle part of the head being concave, the shearing surface being uneven, and burrs being more, etc. are easily caused after trimming.

[0003] For example, the patent with the announcement number CN210059485U discloses a quadrangular bolt burr-free trimming die, which comprises a trimming die and a lower die. The lower die is provided with a vertical die hole for accommodating the shank of the bolt, and the lower part of the die hole is provided with a thimble. The top of the die hole is provided with a square counterbore, the size of which is adapted to the support surface of the quadrangular bolt. The edge of the counterbore can cut and punch to form burrs, so as to avoid the influence of the burrs on the support surface and improve the assembly precision. Although the structure is simple, the single-side trimming is only used, and the middle part of the head of the bolt with a thick head type is easily concave due to the uneven plastic deformation of the material.

[0004] For another example, the patent with the announcement number CN222843091U discloses a bolt trimming die with a deburring structure, which comprises an upper die and a lower die. The lower end of the upper die is fixed with a trimming die. The lower die is provided with a cap preforming groove at the position corresponding to the trimming die. The top edge of the cap preforming groove is sharpened to form a cutting edge. The cap preforming groove is consistent in shape with the trimming die and similar in size. A machining through hole is formed in the cap preforming groove for accommodating the bolt. The lower end of the machining through hole is slidably connected with a thimble. The lower die of the bolt trimming die is provided with the cap preforming groove, and the cutting edge at the top of the cap preforming groove cooperates with the cutting edge of the trimming die to cut the burrs in two directions, so as to achieve good cutting effect and high speed. However, the structure still mainly uses single trimming, and the cutting edge of the lower die only plays an auxiliary role. The true two-way synchronous shearing is not realized, the trimming effect of the bolt with a thick head type is still not ideal, and the problem of head concave is not solved thoroughly.

[0005] In summary, the existing trimming die is prone to cause the problems such as the middle part of the head being concave, the shearing surface being uneven, and burrs being more, etc. when processing the bolt products with a thick head type. Therefore, there is an urgent need in the field for a trimming die and method which can realize two-way synchronous shearing, balanced stress, high trimming quality and effectively avoid the head concave. SUMMARY

[0006] The main purpose of the present application is to provide a trimming die and method for bolt head, through the cooperation of trimming male die and trimming female die to carry out bidirectional trimming, and using trimming male die to trim the trimmed part of trimming female die again in the unloading process, completely avoiding head depression and improving trimming quality.

[0007] To achieve the above purpose, on the one hand, the present application provides a trimming die for bolt head, comprising male die assembly and female die assembly; the male die assembly comprises male die sleeve and trimming male die, the trimming male die is assembled in the center hole of the right end of the male die sleeve; the female die assembly comprises female die sleeve, trimming female die and female die core are sequentially installed in the center hole of the female die sleeve from left to right; the female die core is installed in the center through hole of the female die core; the stepped boss of the left end of the female die core extends into the stepped inner hole of the trimming female die; the caliber of the trimming female die blade edge is larger than the caliber of the trimming male die blade edge, the trimming male die and the trimming female die are oppositely arranged and are used for trimming the head of bolt product together.

[0008] Preferably, the caliber of the trimming female die blade edge is 0.04mm larger than the caliber of the trimming male die blade edge.

[0009] Preferably, the distance between the left end face of the trimming female die blade edge and the left end face of the female die core is H, which satisfies: T / 2≤H≤2T / 3, wherein T is the head thickness of the bolt product.

[0010] Preferably, the center hole of the male die sleeve is a stepped hole, which comprises first right hole segment and first left hole segment from right to left, and the diameter of the first right hole segment is larger than the diameter of the first left hole segment, and the first screw hole is arranged on the side wall of the first right hole segment; the first locking inclined mouth is arranged on the outer peripheral surface of the trimming male die, the trimming male die is installed in the first right hole segment, and the top screw is screwed in the first screw hole and tightens the first locking inclined mouth.

[0011] Preferably, the blanking port is arranged on the bottom wall of the left half segment of the male die sleeve.

[0012] Preferably, the blanking inclined surface is arranged on the right side of the blanking port.

[0013] Preferably, the center hole of the trimming male die is a stepped hole, which comprises male die blade edge hole, first tapered hole and first flared hole from right to left; the taper β of the first tapered hole is 5-8 degrees.

[0014] Preferably, the center hole of the female die sleeve is a stepped hole, sequentially comprising a second left hole section and a second right hole section from left to right, and the diameter of the second left hole section is larger than that of the second right hole section, and a second threaded hole is arranged on the side wall of the second left hole section; a second locking inclined mouth is arranged on the outer peripheral surface of the trimming female die, the trimming female die is installed in the second left hole section, a jacking screw is screwed in the second threaded hole and jacks the second locking inclined mouth.

[0015] Preferably, the center hole of the trimming female die is a stepped hole, sequentially comprising a female die blade hole, a second tapered hole and a second flared hole from left to right; the taper α of the second tapered hole is 5-8 degrees; the shape of the stepped boss at the left end of the female die core is matched with the shapes of the second tapered hole and the second flared hole; the single-edge fitting gap between the female die ejector pin and the center through hole of the female die core is 0.02-0.04 mm, which ensures the smoothness and accuracy of the movement of the female die ejector pin and ensures the stability and reliability of the unloading process.

[0016] In a second aspect, the present application further provides a trimming method for a bolt head, which adopts the trimming die described above and comprises the following steps: S1, installing and fixing the male die assembly in the male die seat of the cold header, and installing and fixing the female die assembly in the female die seat of the cold header; S2, loading the bolt product into the female die assembly through the clamp jaw, and inserting the shank of the bolt product into the center hole of the female die core; S3, starting the cold header to drive the male die assembly to move rightward, and after the trimming male die contacts the bolt head of the bolt product, the trimming male die continues to move rightward to push the bolt product to move rightward until the right end surface of the bolt head contacts the trimming female die; the male die assembly continues to move rightward to make the trimming male die and the trimming female die simultaneously trim the bolt head; S4, when the gap between the trimming male die and the trimming female die reaches a set value, the male die assembly stops moving, the knockout mechanism on the cold header drives the female die ejector pin to move leftward to push the bolt product to move leftward, so that the part cut by the trimming female die is trimmed again by the blade of the trimming male die; the female die ejector pin continues to move leftward to push the bolt product into the center hole of the male die sleeve to complete unloading.

[0017] Thanks to the above technical solutions, the present application has the following advantages: (1) In the present application, the trimming male die and the trimming female die can be used to trim the bolt head in two directions, which avoids the uneven deformation of the material caused by single trimming, and because the caliber of the trimming female die blade is larger than that of the trimming male die blade, when the female die ejector pin pushes the bolt product to exit leftward, the part cut by the trimming female die is trimmed again by the blade of the trimming male die, which avoids the problem of the middle part of the head being concave caused by traditional single trimming.

[0018] (2) The trimming die provided by the application can synchronously trim the bolt head in two directions, so that the material is plastically deformed in a smaller area and more uniformly until being cut off, effectively improving the flatness and perpendicularity of the cut surface and significantly reducing the generation of burrs. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to the structures shown in the drawings without creative labor for those skilled in the art.

[0020] Figure 1 A structure diagram of the trimming die provided by the application; Figure 2 A schematic diagram of trimming the bolt product by using the trimming die provided by the application; Figure 3 A Figure 1 An enlarged view of A in the middle; Figure 4 A structure exploded diagram of the male die assembly in the application; Figure 5 A structure exploded diagram of the female die sleeve and the trimming female die in the application; Figure 6 A structure diagram of the female die core in the application; Figure 7 A structure diagram of the female die ejector rod in the application; Figure 8 A structure diagram of the bolt product.

[0021] Explanation of the reference numerals: 1 - male die assembly, 101 - male die sleeve, 101a - blanking opening, 101b - blanking slope, 101c - first right hole section, 101d - first left hole section, 101e - first threaded hole, 102 - trimming male die, 102a - first locking slope, 102b - male die blade hole, 102c - first tapered hole, 102d - first flared hole; 2 - female die assembly, 201 - female die sleeve, 201a - second left hole section, 201b - second right hole section, 201c - second threaded hole, 202 - trimming female die, 202a - second locking slope, 202b - female die blade hole, 202c - second tapered hole, 202d - second flared hole, 203 - female die core, 204 - female die ejector rod; 3 - bolt product. DETAILED DESCRIPTION

[0022] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0023] It should be noted that all the direction indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the direction indications also change accordingly.

[0024] In addition, the descriptions of “first”, “second” and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as “first”, “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of a person of ordinary skill in the art, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope of the present application.

[0025] In combination with Figures 1 to 8 As shown in the figure, in one aspect, the embodiment provides a trimming die for bolt head, which realizes bidirectional synchronous shearing through the cooperation of the trimming male die 102 and the trimming female die 202, and the trimming male die 102 can trim the trimming part of the trimming female die 202 again during the unloading process, effectively avoiding the head depression problem caused by single trimming, and improving the trimming quality and efficiency. The present application is particularly suitable for bolt products with thick head, such as hexagonal head bolt, whose head thickness is usually large, and traditional single trimming is easy to cause middle depression. The trimming die specifically includes a male die assembly 1 and a female die assembly 2.

[0026] In combination with Figure 1 and Figure 2 As shown in the figure, the male die assembly 1 includes a male die sleeve 101 and a trimming male die 102, and the trimming male die 102 is assembled in the center hole at the right end of the male die sleeve 101.

[0027] The female mold assembly 2 comprises a female mold sleeve 201, a trimming female mold 202 and a female mold core 203 are sequentially arranged in the central hole of the female mold sleeve 201 from left to right, a female mold ejector pin 204 is arranged in the central through hole of the female mold core 203, and the stepped boss at the left end of the female mold core 203 extends into the stepped inner hole of the trimming female mold 202. The caliber of the blade edge of the trimming female mold 202 is larger than that of the blade edge of the trimming male mold 102, the trimming male mold 102 is arranged opposite to the trimming female mold 202, and the trimming male mold 102 and the trimming female mold 202 are used for trimming the head of the bolt product 3 together.

[0028] In combination Figure 2 As shown, in use, the male mold assembly 1 and the female mold assembly 2 are arranged opposite to each other, and the head of the bolt product 3 is located between the male mold assembly 1 and the female mold assembly 2. The rod part of the bolt product 3 is inserted into the central hole of the female mold core 203. In the working process, the male mold assembly 1 moves to the right, pushes the bolt head of the bolt product 3 to interact with the female mold assembly 2, and realizes bidirectional trimming by using the trimming male mold 102 and the trimming female mold 202. After trimming, the female mold ejector pin 204 moves to the left, pushes the bolt product 3 to the left to exit, and because the caliber of the blade edge of the trimming female mold 202 is larger than that of the blade edge of the trimming male mold 102, when the female mold ejector pin 204 pushes the bolt product to the left to exit, the cutting-in part of the trimming female mold 202 is trimmed again by the blade edge of the trimming male mold 102, thereby avoiding the problem of middle head depression caused by traditional single trimming. Specifically, the caliber of the blade edge of the trimming female mold 202 is 0.04 mm larger than that of the blade edge of the trimming male mold 102. If the caliber difference between the blade edges of the trimming female mold 202 and the trimming male mold 102 is greater than 0.04 mm, when the female mold ejector pin 204 pushes the bolt product 3 to the left to exit, the blade edge of the trimming male mold 102 needs to trim a larger thickness of material, which leads to difficult ejection. Therefore, the caliber difference between the blade edges of the trimming female mold 202 and the trimming male mold 102 should not be too large.

[0029] In combination Figure 3 And Figure 8 As shown, the distance between the left end face of the blade edge of the trimming female mold 202 and the left end face of the female mold core 203 is H, which satisfies T / 2≤H≤2T / 3, wherein T is the thickness of the head of the bolt product 3. Through the size design, the trimming length of the bolt head by the trimming female mold 202 is ensured, that is, the trimming length is between T / 2 and 2T / 3.

[0030] In combination Figure 4As shown, the trimming male die 102 is assembled into the male die sleeve 101. The male die sleeve 101 serves as a support structure, and its central hole is designed as a stepped hole, which includes a first right hole section 101c and a first left hole section 101d from right to left. The first right hole section 101c has a larger diameter for accommodating the trimming male die 102. The first left hole section 101d has a smaller diameter, and an axial phase step is formed between the first right hole section 101c and the first left hole section 101d for forming axial limiting for the trimming male die 102. A first threaded hole 101e is arranged on the side wall of the first right hole section 101c. A first locking chamfer 102a is arranged on the outer peripheral surface of the trimming male die 102. The trimming male die 102 is installed in the first right hole section 101c, and the first locking chamfer 102a is clamped by a tightening screw in the first threaded hole 101e, thereby fixing the trimming male die 102.

[0031] Further, a blanking opening 101a is arranged on the bottom wall of the left half of the male die sleeve 101. A blanking slope 101b with an inclination angle of 45° is arranged on the right side of the blanking opening 101a. When the trimming of the bolt product 3 is completed and the bolt product 3 is pushed into the central hole of the male die sleeve 101 by the male die ejector pin 204, the bolt product 3 is guided by the blanking slope 101b to fall from the blanking opening 101a, thereby completing the unloading.

[0032] In this embodiment, the central hole of the trimming male die 102 is a stepped hole, which includes a die blade hole 102b, a first tapered hole 102c and a first flared hole 102d from right to left. The size of the die blade hole 102b matches the final size of the bolt head, which is used to form the hexagonal shape of the bolt head. The taper β of the first tapered hole 102c is 5-8 degrees, preferably 6 degrees. The first tapered hole 102c is arranged to provide a relief for the trimmed bolt head, thereby facilitating unloading.

[0033] In combination Figure 5 As shown, the trimming female die 202 is assembled into the female die sleeve 201. The central hole of the female die sleeve 201 is a stepped hole, which includes a second left hole section 201a and a second right hole section 201b from left to right. The second left hole section 201a has a larger diameter for accommodating the trimming female die 202, and the second right hole section 201b has a smaller diameter for installing the female die core 203. A second threaded hole 201c is arranged on the side wall of the second left hole section 201a. A second locking chamfer 202a is arranged on the outer peripheral surface of the trimming female die 202. The trimming female die 202 is installed in the second left hole section 201a, and the second locking chamfer 202a is clamped by a tightening screw in the second threaded hole 201c, thereby fixing the trimming female die 202.

[0034] Further, the center hole of the trimming die 202 is a stepped hole, including the die edge hole 202b, the second tapered hole 202c and the second flared hole 202d from left to right; the taper α of the second tapered hole 202c is 5-8 degrees. The stepped boss shape of the die core 203 is matched with the shape of the second tapered hole 202c and the second flared hole 202d, ensuring a tight fit. The center through hole of the die core 203 is used to accommodate the shank of the bolt product 3, serving as positioning to prevent the bolt product from shaking. The die ejector rod 204 is installed in the center through hole of the die core 203, and the single-sided gap between the die ejector rod 204 and the through hole is 0.02-0.04mm. This gap design ensures that the die ejector rod 204 can move smoothly and accurately push the material. If the gap is too large, it will affect the pushing accuracy, and if it is too small, it may be stuck due to thermal expansion or impurities.

[0035] In a second aspect, the embodiment provides a trimming method for a bolt head, which adopts the trimming die described above, and includes the following steps: S1, mold installation: install the male die assembly 1 in the male die seat of the cold header and fix it, and install the female die assembly 2 in the female die seat of the cold header and fix it. When installing, the centering tool should be used to ensure that the center axes of the male die assembly 1 and the female die assembly 2 are aligned to ensure trimming accuracy. The male die seat and the female die seat on the cold header are conventional corresponding technologies, which will not be described here.

[0036] S2, product clamping: clamp the bolt product 3 into the female die assembly 2 through the clamp jaw, and insert the shank of the bolt product 3 into the center hole of the die core 203, and the head of the bolt product 3 is located between the male die assembly 1 and the female die assembly 2. The center hole of the die core 203 tightly wraps the shank of the bolt product 3 to prevent it from shaking, ensuring that the product position is stable during trimming.

[0037] S3, trimming process: start the cold header, and the male die assembly 1 moves to the right under the drive of the machine tool. The trimming die 102 first contacts the bolt head of the bolt product 3, and continues to move to the right, pushing the bolt product 3 to move to the right. When the right end surface of the bolt head contacts the edge of the trimming die 202, the trimming die 102 and the trimming die 202 simultaneously apply shearing force to the bolt head, realizing bidirectional trimming.

[0038] S4, discharging: when the gap between the trimming male die 105 and the trimming female die 202 reaches the set value 0.1mm, the male die assembly 1 stops moving, the plate mechanism on the cold header moves, and the female die ejector rod 204 moves to the left. The plate mechanism is the existing structure on the cold header, which is a conventional prior art and will not be described here. The female die ejector rod 204 pushes the bolt product 3 to the left, so that the part cut by the trimming female die 202 is trimmed again by the blade of the trimming male die 102, which is equivalent to a fine cutting, which ensures the trimming quality and removes the burrs and uncut parts that may exist. This trimming action is crucial, which completely avoids the generation of the concave in the middle of the head, and ensures the integrity and aesthetics of the bolt head. Subsequently, the female die ejector rod 204 continues to move to the left, pushes the bolt product 3 into the center hole of the male die sleeve 101, and is discharged from the discharge port 101a under the guidance of the discharge slope 101b, and the discharging is completed. After discharging, the mold is reset, and the next trimming can be performed.

[0039] The present application realizes the balance of shearing force and the improvement of trimming quality through the bidirectional trimming of the trimming female and male dies and the re-trimming during discharging, and is particularly suitable for bolt products with thick head (thickness ≥8mm), which avoids the problem of head depression.

[0040] The above description is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields within the inventive concept of the present application, and the content of the present application specification and drawings are included in the patent protection scope of the present application.

Claims

1. A cutting die for bolt heads, characterized in that, It includes a male mold assembly (1) and a female mold assembly (2); the male mold assembly (1) includes a male mold sleeve (101) and a trimmed male mold (102), the trimmed male mold (102) being assembled in the center hole at the right end of the male mold sleeve (101); The female mold assembly (2) includes a female mold sleeve (201), in which a trimming female mold (202) and a female mold core (203) are installed from left to right in the central hole of the female mold sleeve (201); a female mold ejector rod (204) is installed in the central through hole of the female mold core (203); the stepped boss at the left end of the female mold core (203) extends into the stepped inner hole of the trimming female mold (202); The diameter of the cutting edge of the female cutting die (202) is larger than that of the cutting edge of the male cutting die (102). The male cutting die (102) and the female cutting die (202) are arranged opposite to each other and are used together to cut the head of the bolt product (3).

2. The trimming die according to claim 1, characterized in that, The diameter of the cutting edge of the female cutting die (202) is 0.04 mm larger than that of the cutting edge of the male cutting die (102).

3. The trimming die according to claim 1, characterized in that, The distance between the left end face of the cutting edge of the female mold (202) and the left end face of the female mold core (203) is H, which satisfies: T / 2≤H≤2T / 3, where T is the head thickness of the bolt product (3).

4. The trimming die according to claim 1, characterized in that, The central hole of the male mold sleeve (101) is a stepped hole, which includes a first right hole section (101c) and a first left hole section (101d) from right to left. The diameter of the first right hole section (101c) is larger than the diameter of the first left hole section (101d). A first threaded hole (101e) is provided on the side wall of the first right hole section (101c). A first locking oblique opening (102a) is provided on the outer peripheral surface of the cutting male mold (102). The cutting male mold (102) is installed in the first right hole section (101c). A tightening screw is screwed into the first threaded hole (101e) and tightens the first locking oblique opening (102a).

5. The trimming die according to claim 1, characterized in that, A material discharge port (101a) is provided on the bottom wall of the left half of the male mold sleeve (101).

6. The trimming die according to claim 5, characterized in that, A material discharge ramp (101b) is provided on the right side of the material discharge port (101a).

7. The trimming die according to claim 1, characterized in that, The central hole of the cutting male die (102) is a stepped hole, which includes, from right to left, a male die cutting edge hole (102b), a first conical hole (102c) and a first flared hole (102d); the taper β of the first conical hole (102c) is 5-8 degrees.

8. The trimming die according to claim 1, characterized in that, The central hole of the female mold sleeve (201) is a stepped hole, which includes a second left hole section (201a) and a second right hole section (201b) from left to left. The diameter of the second left hole section (201a) is larger than the diameter of the second right hole section (201b). A second threaded hole (201c) is provided on the side wall of the second left hole section (201a). A second locking bevel (202a) is provided on the outer peripheral surface of the cutting female mold (202). The cutting female mold (202) is installed in the second left hole section (201a). A tightening screw is screwed into the second threaded hole (201c) and tightens the second locking bevel (202a).

9. The trimming die according to claim 1, characterized in that, The central hole of the cutting female die (202) is a stepped hole, which includes, from left to right, a female die cutting edge hole (202b), a second conical hole (202c), and a second flared hole (202d); the taper α of the second conical hole (202c) is 5-8 degrees; The stepped boss shape at the left end of the female mold core (203) is adapted to the shape of the second conical hole (202c) and the second flared hole (202d); The clearance between the female mold ejector pin (204) and the central through hole of the female mold core (203) is 0.02-0.04 mm.

10. A method for trimming the edge of a bolt head, characterized in that, The method of using the trimming die according to any one of claims 1 to 9 includes the following steps: S1. Install and fix the male mold assembly (1) in the male mold base of the cold heading machine, and install and fix the female mold assembly (2) in the female mold base of the cold heading machine; S2. The bolt product (3) is inserted into the female mold assembly (2) by means of the clamping claws, and the shank of the bolt product (3) is inserted into the center hole of the female mold core (203); S3. Start the cold heading machine, drive the male mold assembly (1) to move to the right, and after the cutting male mold (102) contacts the bolt head of the bolt product (3), continue to move to the right, pushing the bolt product (3) to the right until the right end face of the bolt head contacts the cutting female mold (202); the male mold assembly (1) continues to move to the right, so that the cutting male mold (102) and the cutting female mold (202) simultaneously cut the bolt head; S4. When the gap between the cutting male die (105) and the cutting female die (202) reaches the set value, the male die assembly (1) stops moving, and the plate-beating mechanism on the cold heading machine drives the female die ejector rod (204) to move to the left, pushing the bolt product (3) to move to the left, so that the part cut by the cutting female die (202) is cut again by the cutting edge of the cutting male die (102); the female die ejector rod (204) continues to move to the left to push the bolt product (3) into the center hole of the male die sleeve (101) to complete the unloading.

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