Die set for machining straight threads and splines of bolts

Abstract

A die set for machining straight lines and splines of bolts comprises a first die set and a second die set, and in the cold heading process, the first die set and the second die set are adopted to extrude the head and the rod of a to-be-machined bolt correspondingly, so that the straight lines and the splines of the to-be-machined bolt are machined; an inner hexagonal groove and a straight line on the head portion and a spline on the rod portion are formed on the head portion and the rod portion of the bolt to be machined respectively, so that subsequent secondary machining steps are not needed, production efficiency is improved, and meanwhile extra cost generated by secondary machining can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of fasteners, in particular to a die set for processing straight grains and splines of bolts. Background Art

[0002] In existing technology, the traditional method for producing uniformly distributed straight grooves along the circumference of a bolt head is knurling. The traditional methods for producing rectangular spline teeth on the shank include rubbing, knurling, and milling. These methods all require secondary machining of the product blank using cutting tools to form the required straight grooves on the head circumference and rectangular spline teeth on the shank. This results in low production efficiency and high manufacturing costs. Furthermore, the use of cutting tools is subject to tool wear, posing a certain risk to product quality. Summary of the Invention

[0003] In view of this, the utility model provides a die set for processing bolt straight grooves and splines.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] The tool holder is a first tool holder, and a second tool holder is a second tool holder, wherein the tool holder has a first upper mold and a second lower mold, and the tool holder has a first upper mold and a first lower mold. The tool holder has a first upper mold and a first lower mold, and the tool holder has a first upper mold and a first lower mold. The tool holder has a first upper mold and a first lower mold, and the tool holder has a first upper mold and a first lower mold. The tool holder has a first upper mold and a first lower mold, and the tool holder has a first upper mold and a first lower mold. The tool holder has a first upper mold and a first lower mold, and the tool holder has a first upper mold and a first lower mold. The tool holder has a first upper mold and a first lower mold, and the tool holder has a first upper mold and a first lower mold. The tool holder has a first upper mold and a first lower mold, and the tool holder has a first upper mold and a first lower mold.

[0006] Preferably, the first lower die includes a first lower die outer shell, a first lower die main die, a first lower die core and a first lower die base body, the first lower die main die is fixed on the first lower die base body, the first lower die outer shell is covered on the first lower die main die, the first lower die core is arranged in the first lower die main die, the first lower positioning groove is opened on the first lower die core, the first lower die core includes a first rod core and a head lower die core, the head lower die core is arranged in an annular structure, the head lower die core protrudes on the inner ring side to form a plurality of head internal teeth, and the head internal teeth are connected to the lower end of the head of the bolt to be processed.

[0007] Preferably, 36 internal teeth are provided in the head, and the angle between adjacent internal teeth is 110°, and the internal teeth in the head squeeze the lower end of the head of the bolt to be processed.

[0008] Preferably, an alloy mold piece is arranged between the head lower mold core and the first lower mold shell, and three alloy mold pieces are arranged at equal intervals. An inclined surface is arranged on the side of the alloy mold piece close to the first lower mold shell, and the inclination direction of the inclined surface is that the bottom of the side of the alloy mold piece close to the first lower mold shell is inclined toward the upper part of the central axis of the first lower mold shell, and the inclination angle of the inclined surface is 5°.

[0009] Preferably, the first upper mold includes a first upper mold main mold, a first upper mold punch and a first upper mold core, the first upper mold main mold is sleeved on the first upper mold punch, the first upper mold punch has a hexagonal forming end, and a core mounting groove is formed between the hexagonal forming end and the first upper mold main mold, the first upper mold core is sleeved on the hexagonal forming end, the outer side of the first upper mold core is connected to the inner wall of the core mounting groove, and the hexagonal forming end extrude the upper end of the head of the bolt to be processed.

[0010] Preferably, the second lower die includes a second lower die shell, a second lower die main die and a second lower die core, the second lower die shell is sleeved on the second lower die main die, the second lower die core is arranged inside the second lower die main die, the second lower positioning groove is opened on the second lower die core, the rod portion of the bolt to be processed includes an upper rod portion and a lower rod portion, the second lower die core is provided with an upper die core and a lower die core corresponding to the upper rod portion and the lower rod portion, the upper die core and the lower die core are both arranged in a ring structure, the upper die core is provided with a plurality of rod protrusions on the inner ring side, and the rod protrusions squeeze the upper rod portion of the bolt to be processed.

[0011] Preferably, 12 rod protrusions are arranged at equal intervals, and the straight-line distance between adjacent rod protrusions is 1 mm.

[0012] Preferably, the second upper die includes a second upper die main die and a second upper die punch, the second upper positioning groove is opened on a side of the second upper die punch close to the second lower die, and the second upper die main die is sleeved on the second upper die punch.

[0013] The beneficial effect of the present invention is that, during the cold forging process, the first die set and the second die set are used to extrude the head and the shank of the bolt to be processed respectively, so that the hexagonal groove and straight groove on the head and the spline on the shank are formed on the head and the shank of the bolt to be processed respectively, thereby eliminating the need for subsequent secondary processing steps, improving production efficiency and reducing the additional cost generated by secondary processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Attachment Figure 1 Schematic diagram of the first module structure;

[0016] Attachment Figure 2 Schematic diagram of the second module structure;

[0017] Attachment Figure 3 Schematic diagram of the bolt structure to be processed;

[0018] Attachment Figure 4 Schematic diagram of the first lower mold structure;

[0019] Attachment Figure 5 Schematic diagram of the second lower mold structure;

[0020] Attachment Figure 6 This is a schematic diagram of the lower die structure of the head;

[0021] Attachment Figure 7 Schematic diagram of the upper mold core structure;

[0022] Attachment Figure 8 For attachment Figure 4 Enlarged view of point A in the middle. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] The utility model provides the following technical solutions:

[0026] As attached Figure 1-8As shown, the utility model discloses a die set for processing bolt straight grain and spline, comprising a bolt to be processed 1, a first die set and a second die set, the first die set comprising a first upper die 2 and a first lower die 3, the first upper die 2 and the first lower die 3 are respectively provided with a first upper positioning groove 4 and a first lower positioning groove 5, the bolt to be processed 1 has a rod 6 and a head 7, the lower ends of the rod 6 and the head 7 extend into the first lower positioning groove 5 and connect with the first lower die 3, the upper end of the head 7 extends into the first upper positioning groove 4 and connects with the first upper die 2, the first upper die 2 and the first lower die 3 perform the processing on the head 7 of the bolt 1 Extrusion forms an inner hexagonal groove 8 and a straight groove 9 on the upper end face and the lower end outer periphery of the head 7 of the bolt 1 to be processed, respectively; the second die set includes a second upper die 10 and a second lower die 11, and the second upper die 10 and the second lower die 11 are respectively provided with a second upper positioning groove 12 and a second lower positioning groove 13. The head 7 and the shank 6 of the bolt 1 to be processed taken out of the first die set are respectively extended into the second upper positioning groove 12 and the second lower positioning groove 13 and connected with the second upper die 10 and the second lower die 11. The second die set extrude the bolt 1 to be processed, and the second die set extrudes a spline 14 on the shank 6 of the bolt 1 to be processed. Specifically, in this design, by using the first die set and the second die set to extrude the head 7 and the shank 6 of the bolt 1 to be processed during the cold heading process, the inner hexagonal groove 8 and the straight groove 9 on the head 7 and the spline 14 on the shank 6 are respectively formed on the head 7 and the shank 6 of the bolt 1 to be processed, thereby eliminating the need for subsequent secondary processing steps, improving production efficiency and reducing the additional costs incurred by secondary processing.

[0027] Furthermore, the first lower die 3 includes a first lower die outer shell 15, a first lower die main die 16, a first lower die core 17 and a first lower die base 18, the first lower die main die 16 is fixed on the first lower die base 18, the first lower die outer shell 15 is covered on the first lower die main die 16, the first lower die core 17 is arranged in the first lower die main die 16, the first lower positioning groove 5 is opened on the first lower die core 17, the first lower die core 17 includes a first rod core 24 and a head lower die core 25, the head lower die core 25 is arranged in a ring structure, the head lower die core 25 protrudes on the inner ring side to form a plurality of head internal teeth 19, and the head internal teeth 19 are connected to the lower end of the head 7 of the bolt 1 to be processed. Specifically, in this embodiment, the first lower die shell 15 has a first shell body 20 and a die core positioning portion 21. The first shell body 20 is provided with a shell mounting groove 22. The first lower die main mold 16 is fixed in the shell mounting groove 22. The bottom end of the first lower die main mold 16 extends out of the shell mounting groove 22 and is connected to the first lower die base 18, which can ensure the overall stability of the first lower die 3. The die core positioning portion 21 is provided with a die core through hole 23 that is connected to the shell mounting groove 22. The die core through hole 23 limits the head lower die core 25, ensuring the accurate positioning of the head lower die core 25 during the processing, thereby improving the processing accuracy. The head inner teeth 19 protruding on the inner ring side of the head lower die core 25 can squeeze the lower end of the head 7 of the bolt 1 to be processed during the cold heading process, thereby processing the straight line 9 structure at the lower end of the head 7 of the bolt 1 to be processed.

[0028] Furthermore, the head internal teeth 19 are provided in 36 numbers, and the angle between adjacent head internal teeth 19 is 110 degrees. The head internal teeth 19 squeeze the lower end of the head 7 of the bolt 1 to be processed. Specifically, in this embodiment, the head internal teeth 19 are provided in 36 numbers, and the angle between adjacent head internal teeth 19 is 110 degrees. This structural design can better adapt to bolt heads 7 of different sizes and shapes, ensure uniform force during the squeezing process, and avoid local stress concentration or damage.

[0029] Furthermore, an alloy die piece 26 is disposed between the head lower die core 25 and the first lower die shell 15. Three alloy die pieces 26 are arranged at equal intervals. An inclined surface 27 is provided on the side of the alloy die piece 26 adjacent to the first lower die shell 15. The inclined surface 27 is tilted from the bottom of the side of the alloy die piece 26 adjacent to the first lower die shell 15 toward the upper portion of the central axis of the first lower die shell 15. The inclination angle of the inclined surface 27 is 5°. Specifically, in this embodiment, the alloy die piece can be effectively prevented from falling out of the die shell during the part ejection process. At the same time, the increased inclination angle can effectively extend the die piece life and prevent the alloy from cracking during the extrusion of straight lines.

[0030] Furthermore, the first upper die 2 includes a first upper die main die 28, a first upper die punch 29 and a first upper die core 30. The first upper die main die 28 is sleeved on the first upper die punch 29. The first upper die punch 29 has a hexagonal forming end 31. A core mounting groove 32 is formed between the hexagonal forming end 31 and the first upper die main die 28. The first upper die core 30 is sleeved on the hexagonal forming end 31. The outer side of the first upper die core 30 is connected to the inner wall of the core mounting groove 32. The hexagonal forming end 31 extrude the upper end of the head 7 of the bolt 1 to be processed. Specifically, in this embodiment, by providing the hexagonal forming end 31 on the first upper die punch 29, the upper end surface of the head 7 of the bolt 1 to be processed can be processed during the extrusion process of the first upper die 2, thereby forming the inner hexagonal groove 8. Moreover, this design ensures high precision and stability of the processing process. The close cooperation between the first upper die main die 28 and the first upper die punch die 29 not only enhances the stability of the overall structure, but also enables the die core mounting groove 32 to accurately fix the first upper die die core 30, thereby reducing deviation and error during the processing.

[0031] Furthermore, the second lower die 11 includes a second lower die shell 33, a second lower die main die 34 and a second lower die core 35. The second lower die shell 33 is sleeved on the second lower die main die 34. The second lower die core 35 is arranged inside the second lower die main die 34. The second lower positioning groove 13 is opened on the second lower die core 35. The rod 6 of the bolt 1 to be processed includes an upper rod 36 and a lower rod 37. The second lower die core 35 is provided with an upper die core 38 and a lower die core 39 corresponding to the upper rod 36 and the lower rod 37. The upper die core 38 and the lower die core 39 are both arranged in a ring structure. The upper die core 38 is provided with a plurality of rod protrusions 40 on the inner ring side. The rod protrusions 40 squeeze the upper rod 36 of the bolt 1 to be processed. Specifically, in this embodiment, the spline 14 on the bolt 1 to be processed needs to be formed at the upper position of the rod 6. Therefore, the second lower die core 35 is divided into an upper die core 38 and a lower die core 39, and a protruding rod protrusion 40 is provided on the inner ring side of the upper die core 38. The provision of the rod protrusion 40 can extrude the rod 6 of the bolt 1 to be processed during the cold forging process to form the structure of the spline 14.

[0032] Specifically, in this embodiment, twelve rod protrusions 40 are arranged at equal intervals, and the linear distance between adjacent rod protrusions 40 is 1 mm. This structure effectively ensures a uniform and stable distribution of the rod protrusions 40, thereby enhancing the strength and stability of the overall structure. Furthermore, the 1 mm spacing design not only ensures structural compactness but also takes into account the precision requirements of the manufacturing process, avoiding manufacturing difficulties or performance degradation caused by excessively small or large spacing.

[0033] Furthermore, the second upper mold 10 includes a second upper mold main mold 41 and a second upper mold punch 42 , the second upper positioning groove 12 is opened on the side of the second upper mold 10 close to the second lower mold 11 , and the second upper mold main mold 41 is sleeved on the second upper mold punch 42 .

[0034] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A die set for machining bolt straight grain and splines, comprising a bolt to be machined, a first die set, and a second die set, characterized in that: The first die set includes a first upper die and a first lower die, and the first upper locating groove and the first lower locating groove are respectively provided on the first upper die and the first lower die, and the bolt to be processed has a rod and a head, the lower ends of the rod and the head extend into the first lower locating groove and connect with the first lower die, and the upper end of the head extends into the first upper locating groove and connects with the first upper die, and the first upper die and the first lower die extrude the head of the bolt to be processed, and form an inner hexagonal groove and a straight line on the upper end face and the lower end outer periphery of the head of the bolt to be processed respectively; the second die set includes a second upper die and a second lower die, and the second upper die and the second lower die respectively provide a second upper locating groove and a second lower locating groove, the head and the rod of the bolt to be processed taken out from the first die set extend into the second upper locating groove and the second lower locating groove respectively and connect with the second upper die and the second lower die, the second die set extrude the bolt to be processed, and the second die extrude a spline on the rod of the bolt to be processed.

2. The die set for machining bolt straight grooves and splines according to claim 1, characterized in that: The first lower die includes a first lower die outer shell, a first lower die main die, a first lower die core and a first lower die base body, the first lower die main die is fixed on the first lower die base body, the first lower die outer shell is covered on the first lower die main die, the first lower die core is arranged in the first lower die main die, the first lower positioning groove is opened on the first lower die core, the first lower die core includes a first rod core and a head lower die core, the head lower die core is arranged in an annular structure, the head lower die core protrudes on the inner ring side to form a plurality of head internal teeth, and the head internal teeth are connected to the lower end of the head of the bolt to be processed.

3. The die set for machining bolt straight grooves and splines according to claim 2, characterized in that: The head inner teeth are provided with 36 teeth, and the angle between adjacent head inner teeth is 110 degrees. The head inner teeth extrude the lower end of the head of the bolt to be processed to form straight lines.

4. The die set for machining bolt straight grooves and splines according to claim 2, characterized in that: An alloy mold piece is arranged between the head lower mold core and the first lower mold shell, and three alloy mold pieces are arranged at equal intervals. An inclined surface is arranged on the side of the alloy mold piece close to the first lower mold shell. The inclination direction of the inclined surface is that the bottom of the side of the alloy mold piece close to the first lower mold shell is inclined toward the upper part of the central axis of the first lower mold shell, and the inclination angle of the inclined surface is 5°.

5. The die set for machining bolt straight grooves and splines according to claim 1, characterized in that: The first upper die includes a first upper die main die, a first upper die punch and a first upper die core. The first upper die main die is sleeved on the first upper die punch. The first upper die punch has a hexagonal forming end. A core mounting groove is formed between the hexagonal forming end and the first upper die main die. The first upper die core is sleeved on the hexagonal forming end. The outer side of the first upper die core is connected to the inner wall of the core mounting groove. The hexagonal forming end extrude the upper end of the head of the bolt to be processed to form an inner hexagonal groove.

6. The die set for machining bolt straight grooves and splines according to claim 1, characterized in that: The second lower die includes a second lower die shell, a second lower die main die and a second lower die core. The second lower die shell is sleeved on the second lower die main die. The second lower die core is arranged inside the second lower die main die. The second lower positioning groove is opened on the second lower die core. The rod portion of the bolt to be processed includes an upper rod portion and a lower rod portion. The second lower die core is provided with an upper die core and a lower die core corresponding to the upper rod portion and the lower rod portion. The upper die core and the lower die core are both arranged in an annular structure. The upper die core is provided with a plurality of rod protrusions on the inner ring side. The rod protrusions are used to extrude the upper rod portion of the bolt to be processed to form a spline.

7. The die set for machining bolt straight grooves and splines according to claim 6, characterized in that: Twelve rod protrusions are arranged at equal intervals, and the straight-line distance between adjacent rod protrusions is 1 mm.

8. The die set for machining bolt straight grooves and splines according to claim 1, characterized in that: The second upper die includes a second upper die main die and a second upper die punch. The second upper positioning groove is opened on a side of the second upper die punch close to the second lower die. The second upper die main die is sleeved on the second upper die punch.

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