A cold heading die set for front subframe mounting nut pipe

Abstract

The utility model provides a cold heading die set for front subframe mounting nut pipe, including the shearing die of installation in cold heading machine, first die, second die, third die, fourth die, fifth die, sixth die. First die, second die, third die, fourth die, fifth die, sixth die include main mode and punch respectively. First main mode and first punch cooperate, second main mode and second punch cooperate, third main mode and third punch cooperate, fourth main mode and fourth punch cooperate, fifth main mode and fifth punch cooperate, sixth main mode and sixth punch cooperate, and the blank is distributed extrusion, forms nut pipe structure. The utility model sets up multiple stations and extrudes deformation to bar material in turn, and the step cold heading is used for front subframe mounting nut pipe, improves production efficiency and material utilization, avoids direct forming deep hole, reduces forming force, guides material flow, avoids insufficient filling, reduces waste material, improves product quality.

Description

Technical Field

[0001] This utility model belongs to the technical field of cold heading die assembly, specifically relating to a cold heading die assembly for mounting nut tubes on the front subframe. Background Technology

[0002] The subframe is a key load-bearing component in modern automotive chassis systems, connecting the suspension, engine assembly, and body, and directly affecting the vehicle's safety, comfort, and handling stability. The front subframe is securely connected to the body via mounting points, which typically use built-in nut tubes to provide high-strength, high-reliability threaded connections.

[0003] Nut tubes are typically fasteners with a flange at one end and a tubular shape at the other, and are internally threaded. Their traditional manufacturing process primarily uses machining, which is inefficient in terms of material utilization and production efficiency. To overcome the shortcomings of machining, cold heading (cold extrusion) forming technology, as an advanced plastic forming process, has been introduced into the fastener manufacturing field. When applying cold heading technology to components like nut tubes with deep through holes and flanges at one end, such as those mounted on front subframes, the deformation force required for forming with existing cold heading dies is extremely high, placing very high demands on die strength and equipment tonnage. Furthermore, when forming the flange head, the metal material often fails to completely fill the corners of the die cavity, easily leading to unclear flange contours or insufficient dimensions.

[0004] Therefore, the above problems urgently need to be solved. Utility Model Content

[0005] Purpose of the utility model: In order to overcome the above shortcomings, this utility model provides a cold heading die set for front subframe mounting nut tubes. It can cold-form nut tubes with flanges and blind holes in one go with high efficiency. Multiple stations sequentially perform specific deformation on the blanks obtained by cutting metal bars, and finally directly cold-head the front subframe mounting nut tubes with flanges. This improves production efficiency and material utilization, avoids incomplete filling, and improves product quality.

[0006] Technical Solution: To achieve the above objectives, this utility model provides a cold heading die assembly for mounting nut tubes on a front subframe, comprising a shearing die, a first die, a second die, a third die, a fourth die, a fifth die, and a sixth die mounted on a cold heading machine. The shearing die is provided with a shearing chamber for accommodating bar stock.

[0007] The first mold includes a first main mold and a first punch. The first main mold has a first mold cavity, and the first punch has a first punch bar. The first punch bar cooperates with the first mold cavity to form a pre-upsetting positioning hole on the upper end of the blank.

[0008] The second mold includes a second main mold and a second punch. The second main mold has a second mold cavity, and the second punch has a second punch. The second punch cooperates with the second mold cavity to form a pre-upsetting blind hole by reverse extrusion at the lower end of the blank.

[0009] The third mold includes a third main mold and a third punch. The third main mold has a third mold cavity, and the third punch has a third punch. The third punch cooperates with the third mold cavity to form a pre-forged flange head on the upper end of the blank.

[0010] The fourth mold includes a fourth main mold and a fourth punch. The fourth main mold has a fourth mold cavity, and the fourth punch has a fourth punch. The fourth punch cooperates with the fourth mold cavity to extrude the pre-forged flange head into a flange head.

[0011] The fifth mold includes a fifth main mold and a fifth punch. The fifth main mold has a fifth mold cavity, and the fifth punch has a fifth punch. The fifth punch cooperates with the fifth mold cavity to extrude the pre-upsetting blind hole to form a pre-upsetting stepped hole, and extrude the pre-upsetting positioning hole to form a pre-through hole.

[0012] The sixth mold includes a sixth main mold and a sixth punch. The sixth main mold has a sixth mold cavity, and a sixth ejector mechanism is provided on the lower side of the sixth mold cavity. The sixth punch and the sixth ejector mechanism cooperate to open up the pre-upsetting stepped hole and the pre-through hole to form a stepped through hole, thus forming a nut tube structure.

[0013] The installation of nut tubes for the front subframe typically requires multiple machining processes, resulting in low processing efficiency. This invention sets up multiple stations to extrude and deform the bar stock in sequence, and cold-forges it step by step for use as nut tubes for the front subframe, thereby improving production efficiency and material utilization. This invention uses multiple molds to first reverse-extrude blind holes, then bidirectionally extrude to reserve thin walls, and finally lightly punch through, avoiding direct forming of deep holes, reducing forming force, guiding material flow, avoiding incomplete filling, reducing waste, and improving product quality.

[0014] Furthermore, in the aforementioned cold heading die assembly for mounting nut tubes on the front subframe, the first main die includes: a first main die shell, with a first die core connected to one end of the first main die shell near the first punch, the first die core having a first die cavity, and a first ejector pin slidably connected to the first main die shell on the lower side of the first die cavity, the first ejector pin being used to eject the blank within the first die cavity. A first pad is connected to the lower end of the first main die shell, and the first ejector pin is inserted into a through hole provided in the first pad. The first punch includes: a first punch shell, with a first punch bar slidably connected to the first punch shell, the first punch bar and the first die cavity being disposed opposite each other. A guide portion is provided at the lower end of the first punch bar, the guide portion forming a pre-upsetting positioning hole in a recess at the upsetting point of the blank top.

[0015] Furthermore, in the aforementioned cold heading die assembly for mounting nut tubes on the front subframe, the second main die includes: a second main die shell, a second die core connected to one end of the second main die shell near the second punch, the second die core having a second mold cavity, a second ejector mechanism slidably connected to the second main die shell on the lower side of the second mold cavity, the second ejector mechanism including a second mold sleeve located on the lower side of the second mold cavity, a second ejector pin slidably connected within the second mold sleeve, a second pad block connected to the bottom of the second main die shell, the top surface of the second pad block abutting against the second ejector pin, a second push rod slidably connected to the second pad block, the upper end of the second push rod abutting against the second mold sleeve, and the lower end of the second push rod extending out of the second pad block. The second ejector pin is used to form pre-headed blind holes, and the second mold sleeve is used to eject the blank in the second mold cavity. The second punch includes: a second punch shell, a second punch bar slidably connected to the second punch shell, the second punch bar being disposed opposite to the second mold cavity.

[0016] Furthermore, in the aforementioned cold heading die assembly for mounting nut tubes on the front subframe, the third main die includes: a third main die shell; a third die core connected to one end of the third main die shell near the third punch; a third die cavity provided in the third die core; a third ejector mechanism slidably connected to the third main die shell on the lower side of the third die cavity; the third ejector mechanism includes a third die sleeve located on the lower side of the third die cavity; a third ejector pin slidably connected within the third die sleeve; a third pad connected to the bottom of the third main die shell; the third pad abutting against the third ejector pin; a third push rod slidably connected to the third pad; the upper end of the third push rod abutting against the third die sleeve; and the lower end of the third push rod extending out of the third pad. The third ejector pin extends into the third die cavity, and the third die sleeve is used to eject the blank within the third die cavity. The third die includes: a third die shell, a third die core connected to the lower end of the third die shell, a third die cavity provided in the third die core, the bottom surface of the third die cavity being arc-shaped, the third die cavity and the third die cavity forming a mold cavity for forming a pre-upset flange head, and a third punch slidably connected to the third die shell. The third punch extends into the third die cavity and is positioned opposite to the third die cavity. The bottom surface of the third punch is provided with a center point.

[0017] Furthermore, in the aforementioned cold heading die assembly for mounting nut tubes on the front subframe, the fourth main die includes: a fourth main die shell; a fourth die core is connected to one end of the fourth main die shell near the fourth punch; the fourth die core includes a fourth outer die core and a fourth inner die core; the fourth outer die core is sleeved outside the fourth inner die core; the top of the fourth inner die core is lower than the top of the fourth outer die core; the tops of the fourth outer die core and the fourth inner die core form a flange forming cavity for flange head forming; the fourth inner die core has a fourth mold cavity; a fourth ejector mechanism is slidably connected to the fourth main die shell on the lower side of the fourth mold cavity; the fourth ejector mechanism includes a fourth mold sleeve located on the lower side of the fourth mold cavity; a fourth ejector pin slidably connected within the fourth mold sleeve; a fourth pad block is connected to the bottom of the fourth main die shell; the top surface of the fourth pad block abuts against the fourth ejector pin; a fourth push rod is slidably connected to the fourth pad block; the upper end of the fourth push rod abuts against the fourth mold sleeve; and the lower end of the fourth push rod extends out of the fourth pad block. The fourth ejector pin extends into the fourth mold cavity; the fourth mold sleeve is used to eject the blank within the fourth mold cavity.

[0018] The fourth die includes: a fourth die shell, a fourth punch bar slidably connected to the fourth die shell, and the fourth punch bar and the fourth die cavity being arranged opposite to each other.

[0019] Furthermore, in the aforementioned cold heading die assembly for mounting nut tubes on the front subframe, the fifth main die includes: a fifth main die shell, with a fifth die core connected to one end of the fifth main die shell near the fifth punch. The fifth die core includes an upper die core and a lower die core, with the upper die core connected to the top of the lower die core. The inner diameter of the upper die core is larger than that of the lower die core. The tops of the upper and lower die cores form a countersunk chamber for accommodating the flange head. The lower die core has a fifth die cavity, with a fifth ejector mechanism slidably connected to the fifth main die shell on the lower side of the fifth die cavity. The fifth ejector mechanism includes a fifth die sleeve located on the lower side of the fifth die cavity, and a fifth ejector pin slidably connected within the fifth die sleeve. The top of the fifth ejector pin is integrally provided with an upper forming rod and a lower forming rod, with the diameter of the upper forming rod being smaller than that of the lower forming rod. The upper forming rod is used to extrude the bottom of the pre-upsetting blind hole to form a pre-upsetting stepped hole. The outer wall of the lower forming rod is provided with a guide groove along the axis. A fifth pad is connected to the bottom of the fifth main mold shell. The top surface of the fifth pad abuts against the fifth ejector pin. A fifth push rod is slidably connected to the fifth pad. The upper end of the fifth push rod abuts against the fifth mold sleeve, and the lower end of the fifth push rod extends out of the fifth pad. The fifth ejector pin extends into the fifth mold cavity, and the fifth mold sleeve is used to eject the blank inside the fifth mold cavity.

[0020] The fifth die includes: a fifth die shell, a fifth punch slidably connected to the fifth die shell, and the fifth punch and the fifth die cavity being arranged opposite to each other. A fifth punch is slidably connected along the axis of the fifth punch, and the fifth punch is used to extrude the pre-upsetting positioning hole to form a pre-through hole.

[0021] Furthermore, in the aforementioned cold heading die assembly for mounting nut tubes on the front subframe, the sixth main die includes: a sixth main die shell, with a sixth die core slidably connected to one end of the sixth main die shell near the sixth punch. The sixth die core has a sixth die cavity, and a sixth ejector mechanism slidably connected to the sixth main die shell is provided on the lower side of the sixth die cavity. The sixth ejector mechanism includes a sixth die sleeve located on the lower side of the sixth die cavity, and a sixth ejector pin slidably connected within the sixth die sleeve. The top of the sixth ejector pin is integrally provided with an upper rod and a lower rod, the diameter of the upper rod being smaller than the diameter of the lower rod. The upper rod is used to open up the pre-heading stepped hole and the pre-through hole to form a stepped through hole. A guide groove is provided along the axis on the outer side wall of the lower rod. A sixth pad is connected to the bottom of the sixth main die shell, the top surface of the sixth pad abuts against the sixth ejector pin, a sixth push rod is slidably connected to the sixth pad, the upper end of the sixth push rod abuts against the sixth die sleeve, and the lower end of the sixth push rod extends out of the sixth pad. The sixth ejector pin extends into the sixth mold cavity, and the sixth mold sleeve is used to eject the blank inside the sixth mold cavity.

[0022] The sixth die includes: a sixth die shell, a sixth die core connected to the bottom of the sixth die shell, and the sixth die core and the sixth die cavity being arranged opposite to each other. The sixth die core is provided with a blanking hole, and the side wall of the sixth die shell is provided with a blanking groove, which is connected to the blanking hole.

[0023] Furthermore, in the aforementioned cold heading die assembly for mounting nut tubes on the front subframe, the sixth die shell is provided with a guide rod along the axis, the guide rod and the blanking hole are coaxially arranged, and the side of the guide rod near the blanking hole is provided with an inclined surface that is inclined towards the blanking groove.

[0024] This utility model is equipped with multiple molds, and the working steps include: shearing mold: blanking. The bar stock is cut into blanks of a fixed length.

[0025] First mold: positive extrusion positioning hole. A shallow, recessed pre-upsetting positioning hole is pressed out at one end of the billet using the guide part of the first punch.

[0026] Second mold: Reverse extrusion: The second ejector pin is used to reverse extrude upwards from the bottom of the blank, initially forming a deeper pre-upsetting blind hole. This avoids forming an excessively deep hole in a single forward extrusion, reducing the risk of punch breakage.

[0027] Third die: Forward extrusion flange head. Utilizing the arc-shaped bottom surface of the third die cavity, the material at the top of the billet is extruded outward, initially forming a pre-forged flange head in flange shape. The arc-shaped bottom surface design facilitates metal flow.

[0028] Fourth mold: Finishing the flange head. This mold performs the final shaping of the pre-forged flange head, resulting in a flange head with precise dimensions. The fourth mold core employs an inner and outer combined structure, consisting of a fourth outer mold core and a fourth inner mold core, ensuring sharp flange edges and high forming quality.

[0029] Fifth Die: Bidirectional Extrusion Forming of Stepped Holes. The upper forming rod of the fifth ejector pin extends into the bottom of the pre-upset blind hole, extruding its bottom into a smaller diameter to form a pre-upset stepped hole. The fifth punch of the fifth die performs a deep extrusion into the positioning hole, forming a pre-through hole. The pre-upset stepped hole and the pre-through hole are separated by an extremely thin partition, reducing the punching force and avoiding the high load and die wear caused by directly punching through thick material.

[0030] The sixth mold: punches through the blank to form a through hole.

[0031] The upper forming rod of the sixth ejector pin moves upward, acting like a punch, instantly piercing through the thin partition left at the workstation, connecting the pre-upsetting stepped hole and the pre-through hole to form the final stepped through hole. The punched-through waste material is discharged through the blanking hole and blanking groove of the sixth die core. The inclined design of the guide rod ensures that the waste material slides smoothly into the blanking groove, preventing blockage.

[0032] As can be seen from the above technical solution, this utility model has the following beneficial effects: The cold heading die assembly for the front subframe mounting nut tube of this utility model is set up with multiple stations to sequentially extrude and deform the bar stock, cold heading it in stages to produce the front subframe mounting nut tube, thus improving production efficiency and material utilization. By using multiple dies, it achieves first reverse extrusion of blind holes, then bidirectional extrusion to reserve thin walls, and finally light force punching through, avoiding direct forming of deep holes, reducing forming force, guiding material flow, avoiding incomplete filling, reducing waste, and improving product quality. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the cold heading die assembly for mounting nut tubes on the front subframe according to this utility model; Figure 2 This is a cross-sectional view of the first mold; Figure 3 As shown Figure 2 A magnified view of a portion of the image; Figure 4 This is a cross-sectional view of the second mold; Figure 5 This is a cross-sectional view of the third mold; Figure 6 As shown Figure 5 A magnified view of a portion of the image; Figure 7 This is a cross-sectional view of the fourth mold; Figure 8 As shown Figure 7 A magnified view of a portion of the image; Figure 9 This is a cross-sectional view of the fifth mold; Figure 10 As shown Figure 9 A magnified view of a portion of the image; Figure 11This is a cross-sectional view of the sixth mold; Figure 12 As shown Figure 11 A magnified view of a portion of the image; Figure 13 This is a process drawing of the present utility model; Figure 14 This is a structural diagram of the nut tube obtained by cold heading according to this utility model.

[0034] In the diagram: 1. Shearing die; 11. Shearing chamber; 2. First die; 21. First main die; 211. First main die shell; 212. First die core; 213. First mold cavity; 214. First ejector pin; 215. First pad block; 22. First punch; 221. First punch shell; 222. First punch bar; 2221. Guide part; 3. Second die; 31. Second main die; 311. Second main die shell; 312. Second die core; 313. Second mold cavity; 314. Second ejector mechanism; 3141. Second die sleeve; 3142. Second ejector pin; 315. Second pad block; 316. Second push rod; 32. Second punch; 321. Second punch shell; 322. Second punch bar; 4. 41. Third mold, 411. Third main mold, 412. Third main mold shell, 413. Third mold core, 414. Third ejector mechanism, 4141. Third mold sleeve, 4142. Third ejector pin, 415. Third pad block, 416. Third push rod, 42. Third punch, 421. Third punch shell, 422. Third punch bar, 423. Third punch core, 4231. Third punch cavity, 5. Fourth mold, 51. Fourth main mold, 511. Fourth main mold shell, 512. Fourth mold core, 5121. Fourth outer mold core, 5122. Fourth inner mold core, 513. Fourth mold cavity, 514. Fourth ejector mechanism, 5141. Fourth mold sleeve, 5142. Fourth ejector pin, 515. Fourth pad block; 516. Fourth push rod; 52. Fourth punch; 521. Fourth punch shell; 522. Fourth punch; 6. Fifth mold; 61. Fifth main mold; 611. Fifth main mold shell; 612. Fifth mold core; 6121. Fifth upper mold core; 6122. Fifth lower mold core; 613. Fifth mold cavity; 614. Fifth ejector mechanism; 6141. Fifth mold sleeve; 6142. Fifth ejector pin; 61421. Upper forming rod; 61422. Lower forming rod; 615. Fifth pad block; 616. Fifth push rod; 62. Fifth punch; 621. Fifth punch shell; 622. Fifth punch; 623. Fifth punch; 7. Sixth mold; 71. Sixth main mold; 7 11. Sixth main mold shell; 712. Sixth mold core; 713. Sixth mold cavity; 714. Sixth ejector mechanism; 7141. Sixth mold sleeve; 7142. Sixth ejector pin; 71421. Upper forming rod; 7142. Sixth ejector pin; 71422. Lower forming rod; 715. Sixth pad; 716. Sixth push rod; 72. Sixth punch; 721. Sixth punch shell; 722. Sixth punch core; 7221. Blanking hole; 723. Blanking groove; 724. Guide rod; 100. Blank; 101. Pre-upsetting positioning hole; 102. Pre-upsetting blind hole; 103. Pre-upsetting flange head; 104. Flange head; 1051. Pre-upsetting stepped hole; 1052. Pre-through hole; 106. Stepped through hole. Detailed Implementation

[0035] Example 1 like Figure 1-14 The cold heading die assembly shown is for mounting nut tubes on a front subframe. The assembly includes a shearing die 1, a first die 2, a second die 3, a third die 4, a fourth die 5, a fifth die 6, and a sixth die 7, all mounted on a cold heading machine. The shearing die 1 has a shearing chamber 11 for receiving bar stock.

[0036] The first mold 2 includes a first main mold 21 and a first punch 22. The first main mold 21 is provided with a first mold cavity 213, and the first punch 22 is provided with a first punch 222. The first punch 222 cooperates with the first mold cavity 213 to form a pre-upsetting positioning hole 101 on the upper end of the blank 100.

[0037] The second mold 3 includes a second main mold 31 and a second punch 32. The second main mold 31 is provided with a second mold cavity 313, and the second punch 32 is provided with a second punch 322. The second punch 322 cooperates with the second mold cavity 313 to back extrude and form a pre-upsetting blind hole 102 at the lower end of the blank 100.

[0038] The third mold 4 includes a third main mold 41 and a third punch 42. The third main mold 41 is provided with a third mold cavity 413, and the third punch 42 is provided with a third punch 422. The third punch 422 cooperates with the third mold cavity 413 to form a pre-forged flange head 103 on the upper end of the blank 100.

[0039] The fourth mold 5 includes a fourth main mold 51 and a fourth punch 52. The fourth main mold 51 is provided with a fourth mold cavity 513, and the fourth punch 52 is provided with a fourth punch 522. The fourth punch 522 cooperates with the fourth mold cavity 513 to extrude the pre-forged flange head 103 into a flange head 104.

[0040] The fifth mold 6 includes a fifth main mold 61 and a fifth punch 62. The fifth main mold 61 is provided with a fifth mold cavity 613, and the fifth punch 62 is provided with a fifth punch 622. The fifth punch 622 cooperates with the fifth mold cavity 613 to extrude the pre-upsetting blind hole 102 to form a pre-upsetting stepped hole 1051, and extrude the pre-upsetting positioning hole 101 to form a pre-through hole 1052.

[0041] The sixth mold 7 includes a sixth main mold 71 and a sixth punch 72. The sixth main mold 71 is provided with a sixth mold cavity 713. The sixth mold cavity 713 is provided with a sixth ejector mechanism 714 on its lower side. The sixth punch 72 cooperates with the sixth ejector mechanism 714 to open up the pre-upsetting stepped hole 1051 and the pre-through hole 1052 to form a stepped through hole 106, thus forming a nut tube structure.

[0042] like Figure 2-3The cold heading die assembly shown is for mounting nut tubes on the front subframe. The first main die 21 includes: a first main die shell 211, with a first die core 212 connected to one end of the first main die shell 211 near the first die 22. The first die core 212 has a first die cavity 213. A first ejector pin 214, slidably connected to the first main die shell 211, is provided on the lower side of the first die cavity 213. The first ejector pin 214 is used to eject the blank 100 from the first die cavity 213. A first pad 215 is connected to the lower end of the first main die shell 211, and the first ejector pin 214 passes through a through hole provided in the first pad 215. The first die 22 includes: a first die shell 221, with a first punch 222 slidably connected to the first die shell 221. The first punch 222 and the first die cavity 213 are arranged opposite each other. The lower end of the first punch 222 is provided with a guide part 2221, and the guide part 2221 forms a pre-upsetting positioning hole 101 in the recess at the top upsetting point of the blank 100.

[0043] like Figure 4 The cold heading die assembly shown is for mounting nut tubes on the front subframe. The second main die 31 includes: a second main die shell 311, a second die core 312 connected to one end of the second main die shell 311 near the second punch 32, a second die core 312 having a second die cavity 313, a second ejector mechanism 314 slidably connected to the second main die shell 311 on the lower side of the second die cavity 313, the second ejector mechanism 314 including a second die sleeve 3141 located on the lower side of the second die cavity 313, a second ejector pin 3142 slidably connected inside the second die sleeve 3141, a second pad 315 connected to the bottom of the second main die shell 311, the top surface of the second pad 315 abutting against the second ejector pin 3142, a second push rod 316 slidably connected to the second pad 315, the upper end of the second push rod 316 abutting against the second die sleeve 3141, and the lower end of the second push rod 316 extending out of the second pad 315. The second ejector pin 3142 is used to form the pre-upsetting blind hole 102, and the second mold sleeve 3141 is used to eject the blank 100 in the second mold cavity 313. The second punch 32 includes: a second punch shell 321, and a second punch 322 is slidably connected to the second punch shell 321. The second punch 322 and the second mold cavity 313 are arranged opposite to each other.

[0044] like Figure 5-6The cold heading die assembly shown for mounting nut tubes on the front subframe includes a third main die 41 comprising: a third main die shell 411; a third die core 412 connected to one end of the third main die shell 411 near the third punch 42; a third die core 412 having a third die cavity 413; a third ejector mechanism 414 slidably connected to the third main die shell 411 on the lower side of the third die cavity 413; a third ejector pin 4142 slidably connected to the third die sleeve 4141 on the lower side of the third die cavity 413; a third pad 415 connected to the bottom of the third main die shell 411; the third pad 415 abutting against the third ejector pin 4142; a third push rod 416 slidably connected to the third pad 415; the upper end of the third push rod 416 abutting against the third die sleeve 4141; and the lower end of the third push rod 416 extending out of the third pad 415. The third ejector pin 4142 extends into the third mold cavity 413, and the third mold sleeve 4141 is used to eject the blank 100 inside the third mold cavity 413. The third punch 42 includes: a third punch shell 421, with a third punch core 423 connected to the lower end of the third punch shell 421. The third punch core 423 has a third punch cavity 4231, the bottom surface of which is arc-shaped. The third punch cavity 4231 and the third mold cavity 413 form a mold cavity for forming the pre-upset flange head 103. The third punch shell 421 is slidably connected to a third punch 422. The third punch 422 extends into the third punch cavity 4231 and is positioned opposite to the third mold cavity 413. The bottom surface of the third punch 422 has a center point.

[0045] like Figure 7-8 The cold heading die assembly shown is for mounting nut tubes on the front subframe. The fourth main die 51 includes a fourth main die shell 511. A fourth die core 512 is connected to one end of the fourth main die shell 511 near the fourth die 52. The fourth die core 512 includes a fourth outer die core 5121 and a fourth inner die core 5122. The fourth outer die core 5121 is fitted outside the fourth inner die core 5122. The top of the fourth inner die core 5122 is lower than the top of the fourth outer die core 5121. The tops of the fourth outer die core 5121 and the fourth inner die core 5122 form a flange forming cavity for forming the flange head 104. The fourth inner die core 5122 is provided with a fourth... The fourth mold cavity 513 has a fourth ejector mechanism 514 slidably connected to the fourth main mold shell 511 on its lower side. The fourth ejector mechanism 514 includes a fourth mold sleeve 5141 located on the lower side of the fourth mold cavity 513, and a fourth ejector 5142 slidably connected to the fourth mold sleeve 5141. A fourth pad 515 is connected to the bottom of the fourth main mold shell 511. The top surface of the fourth pad 515 abuts against the fourth ejector 5142. A fourth push rod 516 is slidably connected to the fourth pad 515. The upper end of the fourth push rod 516 abuts against the fourth mold sleeve 5141, and the lower end of the fourth push rod 516 extends out of the fourth pad 515. The fourth ejector 5142 extends into the fourth mold cavity 513, and the fourth mold sleeve 5141 is used to eject the blank 100 inside the fourth mold cavity 513.

[0046] The fourth die 52 includes: a fourth die shell 521, a fourth punch 522 slidably connected to the fourth die shell 521, and the fourth punch 522 and the fourth die cavity 513 are arranged opposite to each other.

[0047] like Figure 9-10 The cold heading die assembly shown for mounting nut tubes on the front subframe includes a fifth main die 61 comprising a fifth main die shell 611. A fifth die core 612 is connected to one end of the fifth main die shell 611 near the fifth punch 62. The fifth die core 612 includes a fifth upper die core 6121 and a fifth lower die core 6122. The fifth upper die core 6121 is connected to the top of the fifth lower die core 6122. The inner diameter of the fifth upper die core 6121 is larger than the inner diameter of the fifth lower die core 6122. The tops of the fifth upper die core 6121 and the fifth lower die core 6122 form a countersunk chamber for accommodating the flange head 104. The fifth lower mold core 6122 is provided with a fifth mold cavity 613. A fifth ejector mechanism 614, slidably connected to the fifth main mold shell 611, is provided on the lower side of the fifth mold cavity 613. The fifth ejector mechanism 614 includes a fifth mold sleeve 6141 located on the lower side of the fifth mold cavity 613, and a fifth ejector pin 6142 slidably connected within the fifth mold sleeve 6141. The top of the fifth ejector pin 6142 is integrally provided with an upper forming rod portion 61421 and a lower forming rod portion 61422. The diameter of the upper forming rod portion 61421 is smaller than the diameter of the lower forming rod portion 61422. The upper forming rod portion 61421 is used to extrude the bottom of the pre-upsetting blind hole 102 to form the pre-upsetting stepped hole 1051. A guide groove is provided along the axis on the outer side wall of the lower forming rod portion 61422. The bottom of the fifth main mold shell 611 is connected to a fifth pad 615. The top surface of the fifth pad 615 abuts against the fifth ejector pin 6142. The fifth pad 615 is slidably connected to a fifth push rod 616. The upper end of the fifth push rod 616 abuts against the fifth mold sleeve 6141, and the lower end of the fifth push rod 616 extends out of the fifth pad 615. The fifth ejector pin 6142 extends into the fifth mold cavity 613, and the fifth mold sleeve 6141 is used to eject the blank 100 inside the fifth mold cavity 613.

[0048] The fifth die 62 includes: a fifth die shell 621, a fifth punch 622 slidably connected to the fifth die shell 621, and the fifth punch 622 and the fifth die cavity 613 being disposed opposite to each other. A fifth punch 623 is slidably connected along the axis of the fifth punch 622, and the fifth punch 623 is used to extrude the pre-upsetting positioning hole 101 to form a pre-through hole 1052.

[0049] like Figure 11-12The cold heading die assembly shown is for mounting nut tubes on the front subframe. The sixth main die 71 includes a sixth main die shell 711, with a sixth die core 712 slidably connected to one end of the sixth main die shell 711 near the sixth punch 72. The sixth die core 712 has a sixth die cavity 713. A sixth ejector mechanism 714 is slidably connected to the sixth main die shell 711 on the lower side of the sixth die cavity 713. The sixth ejector mechanism 714 includes a sixth die sleeve 7141 located on the lower side of the sixth die cavity 713, and a sixth ejector 7142 slidably connected inside the sixth die sleeve 7141. The top end of the sixth ejector 7142 is integrally provided with an upper rod portion 71421 and a lower rod portion 71422. The diameter of the upper rod portion 71421 is smaller than the diameter of the lower rod portion 71422. The upper rod portion 71421 is used to open up the pre-heading stepped hole 1051 and the pre-through hole 1052 to form a stepped through hole 106. The outer wall of the lower rod portion 71422 is provided with a guide groove along the axis. The bottom of the sixth main mold shell 711 is connected to a sixth pad 715, the top surface of the sixth pad 715 abuts against the sixth ejector pin 7142, the sixth pad 715 is slidably connected to a sixth push rod 716, the upper end of the sixth push rod 716 abuts against the sixth mold sleeve 7141, and the lower end of the sixth push rod 716 extends out of the sixth pad 715. The sixth ejector pin 7142 extends into the sixth mold cavity 713, and the sixth mold sleeve 7141 is used to eject the blank 100 in the sixth mold cavity 713.

[0050] The sixth die 72 includes: a sixth die shell 721, with a sixth die core 722 connected to the bottom end of the sixth die shell 721, and the sixth die core 722 and the sixth die cavity 713 being disposed opposite to each other. The sixth die core 722 is provided with a blanking hole 7221, and the side wall of the sixth die shell 721 is provided with a blanking groove 723, which communicates with the blanking hole 7221.

[0051] Furthermore, in the aforementioned cold heading die assembly for mounting nut tubes on the front subframe, the sixth die housing 721 is provided with a guide rod 724 along the axis. The guide rod 724 and the blanking hole 7221 are coaxially arranged, and the side of the guide rod 724 near the blanking hole 7221 is provided with an inclined surface that is inclined towards the blanking groove 723.

[0052] This utility model is equipped with multiple molds, and the working steps include: Shearing die 1: Blanking. Cut the bar stock to a fixed length into blanks of 100mm.

[0053] First mold 2: positive extrusion positioning hole. A shallow pit-shaped pre-upsetting positioning hole 101 is pressed out at one end of the blank using the guide part 2221 of the first punch 222.

[0054] Second mold 3: Reverse extrusion: The second ejector pin 3142 is used to reverse extrude upwards from the bottom of the blank, initially forming a deeper pre-upsetting blind hole 102. This avoids forming an excessively deep hole in a single forward extrusion, reducing the risk of punch breakage.

[0055] Third die 4: Forward extrusion flange head. Utilizing the arc-shaped bottom surface of the third die cavity 4231, the material at the upper end of the billet is extruded outward, initially forming a pre-forged flange head 103 in flange shape. The arc-shaped bottom surface design facilitates metal flow.

[0056] Fourth mold 5: Finishing the flange head. The pre-forged flange head 103 is then finalized to obtain a flange head 104 with precise dimensions. The fourth mold core employs an inner and outer combined structure: the outer mold core 5121 and the inner mold core 5122, ensuring clear flange edges and high forming quality.

[0057] Fifth Die 6: Bidirectional Extrusion Forming of Stepped Holes. The upper forming rod 61421 of the fifth ejector pin 6142 extends into the bottom of the pre-upsetting blind hole 102, extruding its bottom into a smaller diameter to form the pre-upsetting stepped hole 1051. The fifth punch 623 of the fifth die 62 performs deep extrusion by pressing downward into the positioning hole 101 to form the pre-through hole 1052. The pre-upsetting stepped hole 1051 and the pre-through hole 1052 are separated by an extremely thin partition, reducing the punching force and avoiding the high load and die wear caused by directly punching through thick material.

[0058] Sixth Die 7: Punching through and blanking to form a through hole. The upper rod 71421 of the sixth ejector pin 7142 moves upward, like a punch, instantly punching through the thin partition left at station 6, connecting the pre-upsetting stepped hole 1051 and the pre-through hole 1052 to form the final stepped through hole 106. The punched waste material is discharged through the blanking hole 7221 and blanking groove 723 of the sixth die core 722. The inclined design of the guide rod 724 ensures that the waste material slides smoothly into the blanking groove 723, preventing blockage.

[0059] The above embodiments are exemplary and are intended to illustrate the technical concept and features of this utility model, so that those skilled in the art can understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A cold heading die assembly for mounting nut tubes on a front subframe, characterized in that: Includes a shearing die (1), a first die (2), a second die (3), a third die (4), a fourth die (5), a fifth die (6), and a sixth die (7) installed on a cold heading machine; the shearing die (1) is provided with a shearing chamber (11) for accommodating bar stock; The first mold (2) includes a first main mold (21) and a first punch (22). The first main mold (21) is provided with a first mold cavity (213), and the first punch (22) is provided with a first punch (222). The first punch (222) cooperates with the first mold cavity (213) to form a pre-upsetting positioning hole (101) on the upper end of the blank (100). The second mold (3) includes a second main mold (31) and a second punch (32). The second main mold (31) is provided with a second mold cavity (313), and the second punch (32) is provided with a second punch (322). The second punch (322) cooperates with the second mold cavity (313) to back-extrude and form a pre-upsetting blind hole (102) at the lower end of the blank (100). The third mold (4) includes a third main mold (41) and a third punch (42). The third main mold (41) is provided with a third mold cavity (413), and the third punch (42) is provided with a third punch (422). The third punch (422) cooperates with the third mold cavity (413) to form a pre-forged flange head (103) at the upper end of the blank (100). The fourth mold (5) includes a fourth main mold (51) and a fourth punch (52). The fourth main mold (51) is provided with a fourth mold cavity (513), and the fourth punch (52) is provided with a fourth punch (522). The fourth punch (522) cooperates with the fourth mold cavity (513) to extrude the pre-forged flange head (103) into a flange head (104). The fifth mold (6) includes a fifth main mold (61) and a fifth punch (62). The fifth main mold (61) is provided with a fifth mold cavity (613), and the fifth punch (62) is provided with a fifth punch (622). The fifth punch (622) cooperates with the fifth mold cavity (613) to extrude the pre-upsetting blind hole (102) to form a pre-upsetting stepped hole (1051) and extrude the pre-upsetting positioning hole (101) to form a pre-through hole (1052). The sixth mold (7) includes a sixth main mold (71) and a sixth punch (72). The sixth main mold (71) is provided with a sixth mold cavity (713). The sixth mold cavity (713) is provided with a sixth ejector mechanism (714) on its lower side. The sixth punch (72) cooperates with the sixth ejector mechanism (714) to open up the pre-upsetting stepped hole (1051) and the pre-through hole (1052) to form a stepped through hole (106) and form a nut tube structure.

2. The cold heading die assembly for mounting nut tubes on the front subframe according to claim 1, characterized in that: The first main mold (21) includes: a first main mold shell (211), the first main mold shell (211) having a first mold core (212) connected to one end near the first punch (22), the first mold core (212) having a first mold cavity (213), the lower side of the first mold cavity (213) having a first ejector pin (214) slidably connected to the first main mold shell (211), the first ejector pin (214) being used to eject the blank (100) in the first mold cavity (213); the lower end of the first main mold shell (211) is connected to a first The first punch (215) is provided with a through hole through which the first ejector pin (214) passes; the first punch (22) includes: a first punch shell (221), the first punch shell (221) is slidably connected to a first punch (222), the first punch (222) and the first die cavity (213) are arranged opposite to each other; the lower end of the first punch (222) is provided with a guide part (2221), the guide part (2221) forms a pre-upsetting positioning hole (101) in the upsetting pit at the top of the blank (100).

3. The cold heading die assembly for mounting nut tubes on the front subframe according to claim 1, characterized in that: The second main mold (31) includes: a second main mold shell (311), a second mold core (312) connected to one end of the second main mold shell (311) near the second punch (32), the second mold core (312) having a second mold cavity (313), a second ejector mechanism (314) slidably connected to the second main mold shell (311) on the lower side of the second mold cavity (313), the second ejector mechanism (314) including a second mold sleeve (3141) located on the lower side of the second mold cavity (313), a second ejector pin (3142) slidably connected to the second mold sleeve (3141), a second pad (315) connected to the bottom of the second main mold shell (311), and the second pad (315) being topped The second ejector pin (3142) abuts against the second ejector pin (3142), and the second push rod (316) is slidably connected to the second push rod (315). The upper end of the second push rod (316) abuts against the second mold sleeve (3141), and the lower end of the second push rod (316) extends out of the second push rod (315). The second ejector pin (3142) is used to form a pre-upset blind hole (102), and the second mold sleeve (3141) is used to eject the blank (100) in the second mold cavity (313). The second punch (32) includes: a second punch shell (321), and a second punch (322) is slidably connected to the second punch shell (321). The second punch (322) and the second mold cavity (313) are arranged opposite to each other.

4. The cold heading die assembly for mounting nut tubes on the front subframe according to claim 1, characterized in that: The third main mold (41) includes: a third main mold shell (411), a third mold core (412) connected to one end of the third main mold shell (411) near the third punch (42), a third mold core (412) having a third mold cavity (413), and a third ejector mechanism (414) slidably connected to the third main mold shell (411) on the lower side of the third mold cavity (413), the third ejector mechanism (414) including a third ejector pin mechanism (414) located on the lower side of the third mold cavity (413). The third mold sleeve (4141) on the side is slidably connected to the third ejector pin (4142) inside the third mold sleeve (4141). The bottom of the third main mold shell (411) is connected to a third pad (415). The third pad (415) and the third ejector pin (4142) abut against each other. The third pad (415) is slidably connected to a third push rod (416). The upper end of the third push rod (416) abuts against the third mold sleeve (4141). 416) The lower end extends out of the third pad (415); the third ejector pin (4142) extends into the third mold cavity (413); the third mold sleeve (4141) is used to eject the blank (100) in the third mold cavity (413); the third punch (42) includes: a third punch shell (421), the lower end of the third punch shell (421) is connected to a third punch core (423), and the third punch core (423) is provided with a third punch cavity (416). 231), the bottom surface of the third die cavity (4231) is arc-shaped, the third die cavity (4231) and the third die cavity (413) form a die cavity for forming a pre-upset flange head (103), the third die shell (421) is slidably connected to the third punch (422); the third punch (422) extends into the third die cavity (4231) and is arranged opposite to the third die cavity (413); the bottom surface of the third punch (422) is provided with a tip.

5. The cold heading die assembly for mounting nut tubes on the front subframe according to claim 1, characterized in that: The fourth main mold (51) includes: a fourth main mold shell (511), and a fourth mold core (512) is connected to one end of the fourth main mold shell (511) near the fourth punch (52). The fourth mold core (512) includes a fourth outer mold core (5121) and a fourth inner mold core (5122). The fourth outer mold core (5121) is sleeved on the outside of the fourth inner mold core (5122). The top of the fourth inner mold core (5122) is lower than the top of the fourth outer mold core (5121). The tops of the fourth outer mold core (5121) and the fourth inner mold core (5122) form a flange forming cavity for forming the flange head (104). The fourth inner mold core (5122) is provided with a fourth mold cavity (513). A fourth ejector pin is slidably connected to the fourth main mold shell (511) on the lower side of the fourth mold cavity (513). The structure (514) includes a fourth mold sleeve (5141) located on the lower side of the fourth mold cavity (513), a fourth ejector pin (5142) slidably connected inside the fourth mold sleeve (5141), a fourth pad (515) connected to the bottom of the fourth main mold shell (511), the top surface of the fourth pad (515) abutting against the fourth ejector pin (5142), a fourth push rod (516) slidably connected to the fourth pad (515), the upper end of the fourth push rod (516) abutting against the fourth mold sleeve (5141), and the lower end of the fourth push rod (516) extending out of the fourth pad (515); the fourth ejector pin (5142) extends into the fourth mold cavity (513), and the fourth mold sleeve (5141) is used to eject the blank (100) inside the fourth mold cavity (513). The fourth die (52) includes: a fourth die shell (521), the fourth die shell (521) being slidably connected to a fourth punch (522), the fourth punch (522) and the fourth die cavity (513) being arranged opposite to each other.

6. The cold heading die assembly for mounting nut tubes on the front subframe according to claim 1, characterized in that: The fifth main mold (61) includes: a fifth main mold shell (611), the fifth main mold shell (611) being connected to a fifth mold core (612) at one end near the fifth punch (62), the fifth mold core (612) including a fifth upper mold core (6121) and a fifth lower mold core (6122), the fifth upper mold core (6121) being connected to the top of the fifth lower mold core (6122), the inner diameter of the fifth upper mold core (6121) being larger than the inner diameter of the ... The top of the fifth mold core (6121) and the fifth lower mold core (6122) form a countersunk chamber for accommodating the flange head (104); the fifth lower mold core (6122) is provided with a fifth mold cavity (613), and the lower side of the fifth mold cavity (613) is provided with a fifth ejector mechanism (614) slidably connected to the fifth main mold shell (611). The fifth ejector mechanism (614) includes a fifth mold sleeve (6141) located on the lower side of the fifth mold cavity (613), and a fifth ejector pin (6142) slidably connected to the fifth mold sleeve (6141). The fifth ejector pin (6142) has an upper forming rod (61421) and a lower forming rod (61422) integrally formed at its top. The diameter of the upper forming rod (61421) is smaller than that of the lower forming rod (61422). The upper forming rod (61421) is used to extrude the bottom of the pre-upsetting blind hole (102) to form the pre-upsetting stepped hole (1051). The outer side wall of the lower forming rod (61422) is provided with a guide groove along the axis. The bottom of the fifth main mold shell (611) is connected to a fifth pad block. 615), the top surface of the fifth pad (615) abuts against the fifth ejector pin (6142), the fifth pad (615) is slidably connected to the fifth push rod (616), the upper end of the fifth push rod (616) abuts against the fifth mold sleeve (6141), the lower end of the fifth push rod (616) extends out of the fifth pad (615); the fifth ejector pin (6142) extends into the fifth mold cavity (613), and the fifth mold sleeve (6141) is used to eject the blank (100) in the fifth mold cavity (613). The fifth die (62) includes: a fifth die shell (621), the fifth die shell (621) being slidably connected to a fifth punch (622), the fifth punch (622) and the fifth die cavity (613) being arranged opposite to each other; and a fifth punch (623) being slidably connected along the axis of the fifth punch (622), the fifth punch (623) being used to extrude the pre-upsetting positioning hole (101) to form a pre-through hole (1052).

7. The cold heading die assembly for mounting nut tubes on the front subframe according to claim 1, characterized in that: The sixth main mold (71) includes: a sixth main mold shell (711), with a sixth mold core (712) slidably connected to one end of the sixth main mold shell (711) near the sixth punch (72); the sixth mold core (712) has a sixth mold cavity (713), and a sixth ejector mechanism (714) slidably connected to the sixth main mold shell (711) is provided on the lower side of the sixth mold cavity (713). The sixth ejector mechanism (714) includes a sixth mold sleeve (7141) located on the lower side of the sixth mold cavity (713), and a sixth ejector (7142) slidably connected to the sixth mold sleeve (7141). The top end of the sixth ejector (7142) is integrally provided with an upper rod portion (71421) and a lower rod portion (71422). The diameter of the upper rod portion (71421) is smaller than the diameter of the lower rod portion (71422). The upper rod (71421) is used to open the pre-upsetting stepped hole (1051) and the pre-through hole (1052) to form a stepped through hole (106); the outer side wall of the lower rod (71422) is provided with a guide groove along the axis; the bottom of the sixth main mold shell (711) is connected to a sixth pad (715), the top surface of the sixth pad (715) abuts against the sixth ejector pin (7142), the sixth pad (715) is slidably connected to a sixth push rod (716), the upper end of the sixth push rod (716) abuts against the sixth mold sleeve (7141), and the lower end of the sixth push rod (716) extends out of the sixth pad (715); the sixth ejector pin (7142) extends into the sixth mold cavity (713), and the sixth mold sleeve (7141) is used to eject the blank (100) in the sixth mold cavity (713). The sixth die (72) includes: a sixth die shell (721), the bottom end of which is connected to a sixth die core (722), the sixth die core (722) and the sixth die cavity (713) being arranged opposite to each other; the sixth die core (722) is provided with a blanking hole (7221), and the side wall of the sixth die shell (721) is provided with a blanking groove (723), the blanking groove (723) and the blanking hole (7221) being connected.

8. The cold heading die assembly for mounting nut tubes on the front subframe according to claim 7, characterized in that: The sixth die shell (721) is provided with a guide rod (724) along the axis. The guide rod (724) and the discharge hole (7221) are coaxially arranged. The side of the guide rod (724) near the discharge hole (7221) is set as an inclined surface that is inclined towards the discharge groove (723).

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