A cold heading die assembly for a leaf spring lifting lug bracket sleeve

Abstract

This utility model provides a cold heading die assembly for a leaf spring lug bracket sleeve, comprising a multi-stage die assembly sequentially installed on a cold heading machine. The assembly includes: a first-stage die for forming a first semi-finished blank with upper and lower positioning holes; a second-stage die for forming a second semi-finished blank with a first pre-heading hole; a third-stage die for forming a third semi-finished blank with a second pre-heading hole; a fourth-stage die for forming a fourth semi-finished blank with a flange head; a fifth-stage die for forming a fifth semi-finished blank with an upper pre-heading countersunk hole; and a sixth-stage die for piercing the upper and second pre-heading holes to form a finished product with stepped through holes, and for forming radial embossing on the top surface of the flange head. This utility model cold-heads and extrudes metal blanks in stages, simultaneously forming radial embossing, reducing processes and improving production efficiency.

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 a leaf spring lifting lug bracket sleeve. Background Technology

[0002] The leaf spring hanger bracket sleeve is a key connecting component in the automotive suspension system, primarily used to achieve a flexible connection between the leaf spring and the vehicle frame. It must withstand alternating loads, vibrations, impacts, and lateral forces during vehicle operation, thus requiring strict standards for structural precision, mechanical properties, and surface quality. Leaf spring hanger bracket sleeves are typically manufactured using cold heading, a process with high material utilization and processing efficiency. However, existing cold heading dies lack guiding mechanisms, leading to misalignment between the punch and the die cavity, resulting in significant hole misalignment in the semi-finished product. Furthermore, the flange head of the leaf spring hanger bracket sleeve needs to be made with an uneven surface to increase friction with the connecting parts, usually requiring an additional embossing process after cold heading, resulting in low production efficiency.

[0003] Therefore, the above problems urgently need to be solved. Utility Model Content

[0004] Purpose of the utility model: To overcome the above shortcomings, this utility model provides a cold heading die assembly for a leaf spring lug bracket sleeve, enabling simultaneous processing of each step, reducing the transfer of semi-finished products, and improving production efficiency. During the forming of the first pre-heading hole, a guiding mechanism guides the second punch to ensure the hole position accuracy of the first pre-heading hole, avoiding skewing, and improving the forming quality of the leaf spring lug bracket sleeve.

[0005] Technical Solution: To achieve the above objectives, this utility model provides a cold heading die assembly for a leaf spring lug bracket sleeve, comprising a multi-sequence die assembly sequentially installed on a cold heading machine, including: a first-sequence die, which includes a first lower die, a first upper die, a first ejector pin, and a first punch. The first ejector pin is slidably disposed within the first lower die, and the first punch is slidably disposed within the first upper die. The first ejector pin and the first punch cooperate to press the two ends of the blank placed in the first lower die to form a first semi-finished blank having an upper positioning hole and a lower positioning hole.

[0006] The two-stage mold includes a second lower mold, a second upper mold, a second ejector pin, and a second punch. The second ejector pin is slidably disposed within the second lower mold, and the second punch is slidably disposed within the second upper mold. The second lower mold is provided with a guiding mechanism, and the second punch is slidably connected to the second lower mold through the guiding mechanism. The second ejector pin and the second punch cooperate to extrude the top of a first semi-finished blank placed within the second lower mold to form a second semi-finished blank with a first pre-upsetting hole.

[0007] The three-stage mold includes a third lower mold, a third upper mold, a third ejector pin, and a third punch. The third ejector pin is slidably disposed within the third lower mold, and the third punch is slidably disposed within the third upper mold. The third ejector pin and the third punch work together to press the bottom end of the second semi-finished blank, which has been flipped and placed within the third lower mold, to form a third semi-finished blank with a second pre-upsetting hole.

[0008] The four-stage mold includes a fourth lower mold, a fourth upper mold, a fourth ejector pin, and a fourth punch. The fourth ejector pin is slidably disposed within the fourth lower mold, and the fourth punch is slidably disposed within the fourth upper mold. The fourth ejector pin and the fourth punch work together to shape the top of the third semi-finished blank, which is placed within the fourth lower mold, into a fourth semi-finished blank with a flange head.

[0009] The five-stage mold includes a fifth lower mold, a fifth upper mold, a fifth ejector pin, and a fifth punch. The fifth ejector pin is slidably disposed within the fifth lower mold, and the fifth punch is slidably disposed within the fifth upper mold. The fifth ejector pin and the fifth punch work together to press the top of the fourth semi-finished blank, which is placed within the fifth lower mold, to form a fifth semi-finished blank with an upper pre-upsetting hole.

[0010] The six-stage mold comprises a sixth lower mold, a sixth upper mold, and a sixth ejector pin. The sixth ejector pin is slidably disposed within the sixth lower mold, and the sixth upper mold is provided with a material discharge groove. The sixth ejector pin and the sixth upper mold cooperate to pierce the upper pre-upsetting hole and the second pre-upsetting hole, forming a finished product with stepped through holes, and is also used to form radial embossing on the top surface of the flange head.

[0011] This utility model's multi-stage mold is installed on a multi-station cold heading machine, enabling simultaneous processing of each step. It cold-heads and extrudes metal billets in stages to form finished products (leaf spring hanger bracket sleeves), and simultaneously forms radial embossing, reducing the transfer of semi-finished products, shortening processes, and improving production efficiency. During the forming of the first pre-heading hole, a guiding mechanism guides the second punch to ensure the hole position accuracy of the first pre-heading hole, avoiding skewing and improving the forming quality of the leaf spring hanger bracket sleeves.

[0012] Furthermore, in the aforementioned cold heading die assembly for the leaf spring lug bracket sleeve, the first lower die includes: a first main die shell, with a first die core connected to one end of the first main die shell adjacent to the first upper die. The first die core has a first die cavity for placing the blank. A first ejector pin is installed on the lower side of the first die cavity, and the first ejector pin and the first main die shell are slidably connected. The tip of the first ejector pin extends into the first die cavity. The first ejector pin abuts against the bottom end of the blank in the first die cavity, and the first ejector pin is used to press the bottom end of the blank to form a first semi-finished blank with a lower positioning hole. A first pad is fitted at the lower end of the first main die shell, and the first ejector pin is slidably connected to a through hole provided in the first pad. A first slip ring is connected to the outer periphery of the first ejector pin, and the first slip ring and the through hole provided in the first pad are slidably engaged.

[0013] The first upper die includes a first die shell, and a first punch is slidably connected inside the first die shell. The first punch is disposed opposite to the first die cavity. The bottom end of the first punch presses against the top end of the blank placed in the first die cavity to form a first semi-finished blank with an upper positioning hole.

[0014] The first mold core includes a first upper mold core and a first lower mold core. The first upper mold core has a first upper cavity along its center line, and the first lower mold core has a first lower cavity. The first upper cavity and the first lower cavity are connected to each other to form a first mold cavity. The depth of the first mold cavity is greater than the length of the blank.

[0015] The first upper die and the first lower die press the blank at both ends, forming upper and lower positioning holes respectively. This provides a reference for subsequent cold heading, ensuring controllable material deformation and preventing cold heading skew. Simultaneously, a first slip ring is installed on the first ejector pin to constrain its movement path, preventing pin wobbling, improving its stability, and enhancing the positional accuracy of the lower positioning hole. During blank stamping, the blank is positioned within the first die cavity, preventing flash from forming at the top and improving finished product quality.

[0016] Furthermore, in the aforementioned cold heading die assembly for the leaf spring lug bracket sleeve, the second lower die includes: a second main die shell, with a second die core connected to one end of the second main die shell adjacent to the second upper die. The second die core has a second die cavity for placing the first semi-finished blank. A second ejector pin is installed on the lower side of the second die cavity, and the second ejector pin and the second main die shell are slidably connected. The tip of the second ejector pin extends into the second die cavity. The second ejector pin abuts against the bottom end of the first semi-finished blank inside the second die cavity, and is used to push the extruded second semi-finished blank out of the second die cavity. A second slip ring is connected to the lower end of the second ejector pin, and the second slip ring is slidably connected inside the second main die shell.

[0017] The second upper die includes a second die shell, a second punch, and the second die shell are slidably connected. The second punch is disposed opposite to the second die cavity. The bottom end of the second punch presses against the top end of the first semi-finished blank placed in the second die cavity to form a second semi-finished blank with a first pre-upsetting hole. The second punch presses against the upper positioning hole to form the first pre-upsetting hole.

[0018] Furthermore, in the aforementioned cold heading die assembly for the leaf spring lug bracket sleeve, the guiding mechanism includes a guide post arranged along the movement direction of the second punch. The lower end of the guide post is connected to the second die shell via a flange, and the second punch is slidably connected to a through hole provided in the flange. The top end of the guide post is connected to a second connecting block. A punch sleeve is slidably connected to the outer periphery of the second connecting block, and a pressure block is connected to the bottom end of the punch sleeve. The pressure block is connected to the second punch. When the second punch is pressing, it pushes the punch sleeve to move towards the second lower die. The second lower die pushes the second punch towards the first semi-finished blank via the pressure block. The pressure block slides along the guide post, and the guide post guides the second punch, ensuring the accuracy of the first pre-heading hole position, avoiding skewing, and improving the forming quality of the leaf spring lug bracket sleeve.

[0019] Furthermore, in the aforementioned cold heading die assembly for the leaf spring lug bracket sleeve, the third lower die includes: a third main die shell, with a third die core connected to one end of the third main die shell adjacent to the third upper die. The third die core contains a third die cavity for holding the second semi-finished blank. A third ejector pin is installed on the lower side of the third die cavity, and the third ejector pin and the third main die shell are slidably connected. The tip of the third ejector pin extends into the third die cavity. The third ejector pin abuts against the second semi-finished blank within the third die cavity. A third top sleeve is fitted over the third ejector pin, with the tip of the third ejector pin extending out of the third top sleeve. A third pad is connected to the bottom surface of the third top sleeve. The third ejector pin is connected to a countersunk through-hole in the third pad. A third pad block is connected to the bottom surface of the third pad, and the third ejector pin and the third pad block abut against each other. A third push rod passes through the third pad block, passing through the third pad and abutting against the bottom surface of the third top sleeve. The third push rod is used to push the third top sleeve to eject the extruded third semi-finished blank from the third die cavity.

[0020] The third upper die includes a third die shell, and a third punch is slidably connected inside the third die shell. The third punch is positioned opposite to the third die cavity, and the outer contour of the third punch matches the inner contour of the third die cavity. The third punch slides along the third die cavity during the cold heading process. The bottom end of the third punch presses against the top of the first semi-finished blank placed in the third die cavity, and the third punch presses against the bottom end of the second semi-finished blank to form a third semi-finished blank with a second pre-heading hole.

[0021] Furthermore, in the aforementioned cold heading die assembly for the leaf spring lug bracket sleeve, the fourth lower die includes: a fourth main die shell, with a fourth die core connected to one end of the fourth main die shell adjacent to the fourth upper die; the fourth die core contains a fourth die cavity for placing the third semi-finished blank. A fourth ejector pin is installed on the lower side of the fourth die cavity, and the fourth ejector pin and the fourth main die shell are slidably connected, with the tip of the fourth ejector pin extending into the fourth die cavity. The fourth ejector pin abuts against the third semi-finished blank within the fourth die cavity. A fourth top sleeve is fitted over the fourth ejector pin, with the tip of the fourth ejector pin extending out of the fourth top sleeve; a fourth pad is connected to the bottom surface of the fourth top sleeve. The fourth ejector pin is connected to a countersunk through hole in the fourth pad; a fourth pad block is connected to the bottom surface of the fourth pad; the fourth pad block is connected to a groove in the fourth pad block; and the fourth ejector pin and the fourth pad block abut against each other. The fourth pad is fitted with a fourth push rod, which passes through the fourth pad plate and abuts against the bottom surface of the fourth top sleeve. The fourth push rod is used to push the fourth top sleeve to push the extruded fourth semi-finished blank out of the fourth mold cavity.

[0022] The fourth mold core includes a fourth upper mold core and a fourth lower mold core. The fourth upper mold core has a fourth upper mold cavity along the center line, and the fourth lower mold core has a fourth lower mold cavity along the center line. The diameter of the fourth upper mold cavity is larger than that of the fourth lower mold cavity. The fourth upper mold cavity and the fourth lower mold cavity form a stepped fourth mold cavity.

[0023] The fourth upper die includes a fourth die shell, and a fourth punch is slidably connected inside the fourth die shell. The fourth punch is positioned opposite to the fourth die cavity, and its outer contour matches the upper contour of the fourth die cavity. During cold heading, the fourth punch slides along the upper end of the fourth die cavity. The fourth punch presses against the top of the third semi-finished blank placed inside the fourth die cavity to form a fourth semi-finished blank with a flange head.

[0024] Furthermore, in the aforementioned cold heading die assembly for the leaf spring lug bracket sleeve, the fifth lower die includes: a fifth main die shell, with a fifth die core connected to one end of the fifth main die shell adjacent to the fifth upper die. The fifth die core contains a fifth die cavity for holding the fourth semi-finished blank. A fifth ejector pin is installed on the lower side of the fifth die cavity, and the fifth ejector pin and the fifth main die shell are slidably connected. The tip of the fifth ejector pin extends into the fifth die cavity. The fifth ejector pin abuts against the fourth semi-finished blank within the fifth die cavity. A fifth top sleeve is fitted over the fifth ejector pin, with the tip of the fifth ejector pin extending out of the fifth top sleeve. A fifth pad is connected to the bottom surface of the fifth top sleeve. The fifth ejector pin is connected to a countersunk through hole in the fifth pad. A fifth push rod passes through the fifth pad and abuts against the bottom surface of the fifth top sleeve. The fifth push rod is used to push the fifth top sleeve to eject the extruded fifth semi-finished blank from the fifth die cavity.

[0025] The fifth mold core includes a fifth upper mold core and a fifth lower mold core. The fifth upper mold core has a fifth upper mold cavity along the center line, and the fifth lower mold core has a fifth lower mold cavity along the center line. The diameter of the fifth upper mold cavity is larger than that of the fifth lower mold cavity. The fifth upper mold cavity and the fifth lower mold cavity form a stepped fifth mold cavity.

[0026] The fifth upper die includes a fifth die shell, and a fifth punch is slidably connected inside the fifth die shell. The fifth punch is positioned opposite to the fifth die cavity, and its outer contour matches the upper contour of the fifth die cavity. During cold heading, the fifth punch slides along the upper end of the fifth die cavity. The fifth punch presses against the top of the fourth semi-finished blank placed inside the fifth die cavity to form a fifth semi-finished blank with an upper pre-heading countersunk hole.

[0027] Furthermore, in the aforementioned cold heading die assembly for the leaf spring lug bracket sleeve, the sixth lower die includes: a sixth main die shell, with a sixth die core connected to one end of the sixth main die shell adjacent to the sixth upper die; the sixth die core contains a sixth die cavity for placing the fifth semi-finished blank. A sixth ejector pin is installed on the lower side of the sixth die cavity, and the sixth ejector pin and the sixth main die shell are slidably connected, with the tip of the sixth ejector pin extending into the sixth die cavity. The sixth ejector pin abuts against the fifth semi-finished blank within the sixth die cavity. A sixth ejector sleeve is fitted over the sixth ejector pin, with the tip of the sixth ejector pin extending out of the sixth ejector sleeve; a sixth pad is connected to the bottom surface of the sixth ejector sleeve. The sixth ejector pin is connected to a countersunk through hole in the sixth pad. A sixth pad block is connected to the bottom surface of the sixth pad, and the sixth ejector pin abuts against the sixth pad block. A sixth push rod passes through the sixth pad block, and the sixth push rod passes through the sixth pad and abuts against the bottom surface of the sixth ejector sleeve. The sixth ejector is used to extrude the fifth semi-finished blank placed in the sixth mold cavity to form a finished product, and the sixth pusher is used to push the sixth ejector sleeve to push the extruded finished product out of the sixth mold cavity.

[0028] The sixth upper mold has a pressure core at one end near the sixth mold core. The pressure core has a through hole in the center that communicates with the material discharge groove. The bottom surface of the pressure core has radial protrusions for forming radial embossing.

[0029] The inner diameter of the sixth mold cavity is the same as the diameter of the rod portion of the fifth semi-finished blank, and the flange head abuts against the top surface of the sixth mold core. The tip of the sixth ejector pin is tapered and mates with the second pre-upsetting hole of the fifth semi-finished blank. During cold upsetting, it moves axially along the second pre-upsetting hole, upsetting the second pre-upsetting hole and the upper pre-upsetting countersunk hole together, and the waste material is discharged from the discharge groove. At the same time, the radial protrusions on the bottom surface of the pressure core of the sixth upper mold press against the top surface of the flange head to form a radial embossing. Then the sixth lower mold and the sixth upper mold separate, the sixth push rod pushes the sixth ejector sleeve, and the sixth ejector sleeve pushes the rod portion of the finished product out of the sixth mold cavity, while the sixth ejector pin remains stationary to avoid damaging the stepped through-hole structure of the finished product.

[0030] As can be seen from the above technical solution, this utility model has the following beneficial effects: The cold heading die assembly for the leaf spring lug bracket sleeve of this utility model cold-heads and extrudes the metal billet in stages to form the finished product (leaf spring lug bracket sleeve), avoiding stress concentration caused by large deformation at one time, reducing defects such as cracks and wrinkles, improving forming accuracy and quality, and simultaneously forming radial embossing, reducing the transfer of semi-finished products, shortening processes, and improving production efficiency. When forming the first pre-heading hole, the guiding mechanism guides the second punch to ensure the hole position accuracy of the first pre-heading hole, avoiding skewing, and improving the forming quality of the leaf spring lug bracket sleeve. The guide post guides the movement of the second punch, ensuring the hole position accuracy of the first pre-heading hole, avoiding skewing, and improving the forming quality of the leaf spring lug bracket sleeve. Attached Figure Description

[0031] Figure 1 This is a top view of the finished product; Figure 2 As shown Figure 1 Sectional view along axis AA; Figure 3 This is a product process drawing of this utility model; Figure 4 This is a cross-sectional view of the cold heading die assembly for the leaf spring lifting lug bracket sleeve of this utility model; Figure 5 This is a cross-sectional view of the first-order mold; Figure 6 This is a cross-sectional view of the two-stage mold; Figure 7 This is a cross-sectional view of the three-stage mold; Figure 8 This is a cross-sectional view of the four-stage mold; Figure 9 This is a cross-sectional view of the five-stage mold; Figure 10 This is a cross-sectional view of the six-stage mold; In the diagram: 100, billet; 101, first semi-finished billet; 1011, upper positioning hole; 1012, lower positioning hole; 102, second semi-finished billet; 1021, first pre-upsetting hole; 103, third semi-finished billet; 1031, second pre-upsetting hole; 104, fourth semi-finished billet; 1041, flange head; 105, fifth semi-finished billet; 1051, upper pre-upsetting countersunk hole; 106, finished product; 1061, radial embossing. 1. First mold assembly; 11. First lower mold; 111. First main mold shell; 112. First mold core; 1121. First upper mold core; 1122. First lower mold core; 113. First mold cavity; 115. First spacer block; 12. First upper mold; 121. First punch shell; 13. First ejector pin; 131. First slip ring; 14. First punch. 2. Second-stage mold, 21. Second lower mold, 211. Second main mold shell, 221. Second punch shell, 212. Second mold core, 213. Second mold cavity, 22. Second upper mold, 23. Second ejector pin, 2231. Guide pillar, 2232. Flange, 2233. Second connecting block, 2234. Punch sleeve, 2235. Pressure block, 231. Second slip ring, 24. Second punch. 3. Three-stage mold, 31. Third lower mold, 311. Third main mold shell, 312. Third mold core, 313. Third mold cavity, 32. Third upper mold, 321. Third punch shell, 33. Third ejector pin, 331. Third ejector sleeve, 34. Third punch, 35. Third backing plate, 36. Third pad block, 37. Third push rod. 4. Four-stage mold, 41. Fourth lower mold, 411. Fourth main mold shell, 412. Fourth mold core, 4121. Fourth upper mold core, 4122. Fourth lower mold core, 413. Fourth mold cavity, 42. Fourth upper mold, 421. Fourth punch shell, 43. Fourth ejector pin, 431. Fourth ejector sleeve, 432. Fourth slip ring, 44. Fourth punch, 45. Fourth pad, 46. Fourth pad block, 47. Fourth push rod. 5. Five-stage mold, 51. Fifth lower mold, 511. Fifth main mold shell, 512. Fifth mold core, 5121. Fifth upper mold core, 5122. Fifth lower mold core, 513. Fifth mold cavity, 52. Fifth upper mold, 521. Fifth punch shell, 53. Fifth ejector pin, 531. Fifth ejector sleeve, 54. Fifth punch, 55. Fifth backing plate, 57. Fifth push rod. 6. Sixth mold, 61. Sixth lower mold, 611. Sixth main mold shell, 612. Sixth mold core, 613. Sixth mold cavity, 62. Sixth upper mold, 621. Material slot, 622. Pressing core, 63. Sixth ejector pin, 631. Sixth ejector sleeve, 65. Sixth pad, 66. Sixth pad block, 67. Sixth push rod. Detailed Implementation

[0032] Example 1 like Figure 1-4 The cold heading die assembly shown includes a multi-stage die set sequentially installed on a cold heading machine, comprising: a first-stage die 1, which includes a first lower die 11, a first upper die 12, a first ejector pin 13, and a first punch 14. The first ejector pin 13 is slidably disposed within the first lower die 11, and the first punch 14 is slidably disposed within the first upper die 12. The first ejector pin 13 and the first punch 14 cooperate to press the two ends of a blank 100 placed in the first lower die 11 to form a first semi-finished blank 101 having an upper positioning hole 1011 and a lower positioning hole 1012.

[0033] The second-stage mold 2 includes a second lower mold 21, a second upper mold 22, a second ejector pin 23, and a second punch 24. The second ejector pin 23 is slidably disposed within the second lower mold 21, and the second punch 24 is slidably disposed within the second upper mold 22. The second lower mold 21 is provided with a guide mechanism, and the second punch 24 is slidably connected to the second lower mold 21 through the guide mechanism. The second ejector pin 23 and the second punch 24 cooperate to extrude the top of the first semi-finished blank 101 placed within the second lower mold 21 to form a second semi-finished blank 102 having a first pre-upsetting hole 1021.

[0034] The three-stage mold 3 includes a third lower mold 31, a third upper mold 32, a third ejector pin 33, and a third punch 34. The third ejector pin 33 is slidably disposed within the third lower mold 31, and the third punch 34 is slidably disposed within the third upper mold 32. The third ejector pin 33 and the third punch 34 cooperate to extrude the bottom end of the second semi-finished blank 102, which has been flipped and placed within the third lower mold 31, to form a third semi-finished blank 103 with a second pre-upsetting hole 1031.

[0035] The fourth mold 4 includes a fourth lower mold 41, a fourth upper mold 42, a fourth ejector pin 43, and a fourth punch 44. The fourth ejector pin 43 is slidably disposed within the fourth lower mold 41, and the fourth punch 44 is slidably disposed within the fourth upper mold 42. The fourth ejector pin 43 and the fourth punch 44 cooperate to shape the top of the third semi-finished blank 103 placed within the fourth lower mold 41 to form a fourth semi-finished blank 104 with a flange head 1041.

[0036] The five-stage mold 5 includes a fifth lower mold 51, a fifth upper mold 52, a fifth ejector pin 53, and a fifth punch 54. The fifth ejector pin 53 is slidably disposed within the fifth lower mold 51, and the fifth punch 54 is slidably disposed within the fifth upper mold 52. The fifth ejector pin 53 and the fifth punch 54 cooperate to press the top of the fourth semi-finished blank 104 placed within the fifth lower mold 51 to form a fifth semi-finished blank 105 with an upper pre-upsetting countersunk hole 1051.

[0037] The six-stage mold 6 includes a sixth lower mold 61, a sixth upper mold 62, and a sixth ejector pin 63. The sixth ejector pin 63 is slidably disposed within the sixth lower mold 61, and the sixth upper mold 62 is provided with a material discharge groove 621. The sixth ejector pin 63 and the sixth upper mold 62 cooperate to upset the upper pre-upsetting countersunk hole 1051 and the second pre-upsetting hole 1031, forming a finished product 106 with stepped through holes, and forming radial embossing 1061 on the top surface of the flange head 1041.

[0038] like Figure 5The cold heading die assembly for the leaf spring lug bracket sleeve shown includes a first lower die 11 comprising: a first main die shell 111, with a first die core 112 connected to one end of the first main die shell 111 adjacent to the first upper die 12; the first die core 112 has a first die cavity 113 for placing the blank 100; a first ejector pin 13 is mounted on the lower side of the first die cavity 113, and the first ejector pin 13 and the first main die shell 111 are slidably connected, with the tip of the first ejector pin 13 extending into the first die cavity 113; the first ejector pin 13 abuts against the bottom end of the blank 100 in the first die cavity 113, and the first ejector pin 13 is used to press the bottom end of the blank 100 to form a first semi-finished blank 101 with a lower positioning hole 1012; a first pad 115 is fitted to the lower end of the first main die shell 111, and the first ejector pin 13 is slidably connected to the through hole provided in the first pad 115. The first ejector pin 13 is connected to the outer periphery of the first slip ring 131, and the first slip ring 131 and the first pad 115 are provided with through holes for sliding engagement.

[0039] The first upper die 12 includes a first die shell 121, and a first punch 14 is slidably connected inside the first die shell 121. The first punch 14 is disposed opposite to the first die cavity 113. The bottom end of the first punch 14 presses against the top end of the blank 100 placed in the first die cavity 113 to form a first semi-finished blank 101 with an upper positioning hole 1011.

[0040] The first mold core 112 includes a first upper mold core 1121 and a first lower mold core 1122. The first upper mold core 1121 has a first upper cavity along the center line, and the first lower mold core 1122 has a first lower cavity. The first upper cavity and the first lower cavity are connected to each other to form a first mold cavity 113. The depth of the first mold cavity 113 is greater than the length of the blank 100.

[0041] The first upper die 12 and the first lower die 11 press the blank 100 at both ends, forming the upper positioning hole 1011 and the lower positioning hole 1012 respectively. This provides a reference for subsequent cold heading, ensuring controllable material deformation and preventing cold heading skew. Simultaneously, a first slip ring 131 is provided on the first ejector pin 13 to constrain its movement path, preventing it from wobbling and improving its stability, as well as the positional accuracy of the lower positioning hole 1012. During stamping, the blank 100 is positioned within the first die cavity 113, preventing flash from forming at the top of the blank 100 and improving the quality of the finished product.

[0042] like Figure 6The cold heading die assembly for the leaf spring lug bracket sleeve shown includes a second lower die 21 comprising: a second main die shell 211, with a second die core 212 connected to one end of the second main die shell 211 adjacent to the second upper die 22; the second die core 212 has a second die cavity 213 for holding a first semi-finished blank 101; a second ejector pin 23 is mounted on the lower side of the second die cavity 213, and is slidably connected to the second main die shell 211; the tip of the second ejector pin 23 extends into the second die cavity 213; the second ejector pin 23 abuts against the bottom end of the first semi-finished blank 101 within the second die cavity 213; and the second ejector pin 23 is used to eject the extruded second semi-finished blank 102 from the second die cavity 213; a second slip ring 231 is connected to the lower end of the second ejector pin 23, and the second slip ring 231 is slidably connected within the second main die shell 211.

[0043] The second upper die 22 includes a second die shell 221, a second punch 24 and a second die shell 221 slidably connected, and the second punch 24 is disposed opposite to the second die cavity 213. The bottom end of the second punch 24 presses against the top end of the first semi-finished blank 101 placed in the second die cavity 213 to form a second semi-finished blank 102 with a first pre-upsetting hole 1021. The second punch 24 presses against the upper positioning hole 1011 to form the first pre-upsetting hole 1021.

[0044] In this embodiment, the guiding mechanism includes a guide post 2231 arranged along the movement direction of the second punch 24. The lower end of the guide post 2231 is connected to the second die housing 221 via a flange 2232, and the second punch 24 is slidably connected to a through hole provided in the flange 2232. The top end of the guide post 2231 is connected to a second connecting block 2233. A punch sleeve 2234 is slidably connected to the outer periphery of the second connecting block 2233, and a pressure block 2235 is connected to the bottom end of the punch sleeve 2234. The pressure block 2235 is connected to the second punch 24. When the second punch 24 is punching, it pushes the punch sleeve 2234 to move towards the second lower die 21. The second lower die 21 pushes the second punch 24 to press against the first semi-finished blank 101 through the pressure block 2235. The pressure block 2235 slides along the guide post 2231, and the guide post 2231 guides the second punch 24 to ensure the hole position accuracy of the first pre-upsetting hole 1021, avoid skewing, and improve the forming quality of the leaf spring lifting lug bracket sleeve.

[0045] like Figure 7The cold heading die assembly for the leaf spring lug bracket sleeve shown includes a third lower die 31 comprising a third main die shell 311. A third die core 312 is connected to one end of the third main die shell 311 adjacent to the third upper die 32. The third die core 312 contains a third die cavity 313 for holding the second semi-finished blank 102. A third ejector pin 33 is mounted on the lower side of the third die cavity 313. The third ejector pin 33 and the third main die shell 311 are slidably connected, with the tip of the third ejector pin 33 extending into the third die cavity 313. The third ejector pin 33 abuts against the second semi-finished blank 102 within the third die cavity 313. A third top sleeve 331 is fitted over the third ejector pin 33, with the tip of the third ejector pin 33 extending out of the third top sleeve 331. A third pad 35 is connected to the bottom surface of the third top sleeve 331. The third ejector pin 33 is connected to the countersunk through hole provided in the third pad 35. The bottom surface of the third pad 35 is connected to the third pad block 36, and the third ejector pin 33 and the third pad block 36 abut against each other. The third pad block 36 is provided with a third push rod 37, which passes through the third pad 35 and abuts against the bottom surface of the third top sleeve 331. The third push rod 37 is used to push the third top sleeve 331 to push the extruded third semi-finished blank 103 out of the third mold cavity 313.

[0046] The third upper die 32 includes a third die shell 321. A third punch 34 is slidably connected within the third die shell 321. The third punch 34 is disposed opposite to the third die cavity 313, and the outer contour of the third punch 34 is adapted to the inner contour of the third die cavity 313. During the cold heading process, the third punch 34 slides along the third die cavity 313. The bottom end of the third punch 34 presses against the top end of the first semi-finished blank 101 placed in the third die cavity 313, and the third ejector pin 33 presses against the bottom end of the second semi-finished blank 102 to form a third semi-finished blank 103 with a second pre-heading hole 1031.

[0047] like Figure 8The cold heading die assembly shown for the leaf spring lug bracket sleeve includes a fourth lower die 41 comprising: a fourth main die shell 411, with a fourth die core 412 connected to one end of the fourth main die shell 411 adjacent to the fourth upper die 42; a fourth die cavity 413 is provided inside the fourth die core 412 for placing the third semi-finished blank 103; a fourth ejector pin 43 is installed on the lower side of the fourth die cavity 413, and the fourth ejector pin 43 and the fourth main die shell 411 are slidably connected, with the tip of the fourth ejector pin 43 extending into the fourth die cavity 413; the fourth ejector pin 43 abuts against the third semi-finished blank 103 inside the fourth die cavity 413; a fourth top sleeve 431 is fitted over the fourth ejector pin 43, with the tip of the fourth ejector pin 43 extending out of the fourth top sleeve 431; and a fourth pad 45 is connected to the bottom surface of the fourth top sleeve 431. The fourth ejector pin 43 is connected to the countersunk through hole of the fourth pad 45. The bottom surface of the fourth pad 45 is connected to the fourth pad block 46, and the fourth pad 45 is connected to the groove of the fourth pad block 46. The fourth ejector pin 43 and the fourth pad block 46 abut against each other. The fourth pad block 46 is provided with a fourth push rod 47, which passes through the fourth pad 45 and abuts against the bottom surface of the fourth top sleeve 431. The fourth push rod 47 is used to push the fourth top sleeve 431 to push the extruded fourth semi-finished blank 104 out of the fourth mold cavity 413.

[0048] The fourth mold core 412 includes a fourth upper mold core 4121 and a fourth lower mold core 4122. The fourth upper mold core 4121 has a fourth upper mold cavity along the center line, and the fourth lower mold core 4122 has a fourth lower mold cavity along the center line. The diameter of the fourth upper mold cavity is larger than that of the fourth lower mold cavity. The fourth upper mold cavity and the fourth lower mold cavity form a stepped fourth mold cavity 413.

[0049] The fourth upper die 42 includes a fourth die shell 421. A fourth punch 44 is slidably connected within the fourth die shell 421. The fourth punch 44 is disposed opposite to the fourth die cavity 413, and the outer contour of the fourth punch 44 is adapted to the upper contour of the fourth die cavity 413. During cold heading, the fourth punch 44 slides along the upper end of the fourth die cavity 413. The fourth punch 44 presses the top of the third semi-finished blank 103 placed in the fourth die cavity 413 to form a fourth semi-finished blank 104 with a flange head 1041.

[0050] like Figure 9The cold heading die assembly for the leaf spring lug bracket sleeve shown includes a fifth lower die 51 comprising a fifth main die shell 511. A fifth die core 512 is connected to one end of the fifth main die shell 511 adjacent to the fifth upper die 52. The fifth die core 512 contains a fifth die cavity 513 for holding a fourth semi-finished blank 104. A fifth ejector pin 53 is mounted on the lower side of the fifth die cavity 513. The fifth ejector pin 53 and the fifth main die shell 511 are slidably connected, with the tip of the fifth ejector pin 53 extending into the fifth die cavity 513. The fifth ejector pin 53 abuts against the fourth semi-finished blank 104 within the fifth die cavity 513. A fifth top sleeve 531 is fitted over the fifth ejector pin 53, with the tip of the fifth ejector pin 53 extending out of the fifth top sleeve 531. A fifth pad 55 is connected to the bottom surface of the fifth top sleeve 531. The fifth ejector pin 53 is connected to the countersunk through hole provided in the fifth pad 55. The fifth pad 55 is provided with a fifth push rod 57. The fifth push rod 57 passes through the fifth pad 55 and abuts against the bottom surface of the fifth top sleeve 531. The fifth push rod 57 is used to push the fifth top sleeve 531 to push the extruded fifth semi-finished blank 105 out of the fifth mold cavity 513.

[0051] The fifth mold core 512 includes a fifth upper mold core 5121 and a fifth lower mold core 5122. The fifth upper mold core 5121 has a fifth upper mold cavity along the center line, and the fifth lower mold core 5122 has a fifth lower mold cavity along the center line. The diameter of the fifth upper mold cavity is larger than that of the fifth lower mold cavity. The fifth upper mold cavity and the fifth lower mold cavity form a stepped fifth mold cavity 513.

[0052] The fifth upper die 52 includes a fifth die shell 521. A fifth punch 54 is slidably connected within the fifth die shell 521. The fifth punch 54 is disposed opposite to the fifth die cavity 513, and the outer contour of the fifth punch 54 is adapted to the upper contour of the fifth die cavity 513. During the cold heading process, the fifth punch 54 slides along the upper end of the fifth die cavity 513. The fifth punch 54 presses the top of the fourth semi-finished blank 104 placed in the fifth die cavity 513 to form a fifth semi-finished blank 105 with an upper pre-heading countersunk hole 1051.

[0053] like Figure 10The cold heading die assembly for the leaf spring lug bracket sleeve shown includes a sixth lower die 61 comprising: a sixth main die shell 611, with a sixth die core 612 connected to one end of the sixth main die shell 611 adjacent to the sixth upper die 62; a sixth die cavity 613 is provided within the sixth die core 612 for placing a fifth semi-finished blank 105; a sixth ejector pin 63 is installed on the lower side of the sixth die cavity 613, and the sixth ejector pin 63 and the sixth main die shell 611 are slidably connected, with the tip of the sixth ejector pin 63 extending into the sixth die cavity 613; the sixth ejector pin 63 abuts against the fifth semi-finished blank 105 within the sixth die cavity 613; a sixth ejector sleeve 631 is fitted over the sixth ejector pin 63, with the tip of the sixth ejector pin 63 extending out of the sixth ejector sleeve 631; a sixth pad 65 is connected to the bottom surface of the sixth ejector sleeve 631; and the sixth ejector pin 63 is connected to a countersunk through hole provided in the sixth pad 65. A sixth pad 66 is connected to the bottom surface of the sixth pad 65, and the sixth ejector pin 63 abuts against the sixth pad 66. A sixth push rod 67 passes through the sixth pad 66, and the sixth push rod 67 passes through the bottom surface of the sixth pad 65 and abuts against the sixth top sleeve 631. The sixth ejector pin 63 extrudes the fifth semi-finished blank 105 placed in the sixth mold cavity 613 to form the finished product 106, and the sixth push rod 67 is used to push the sixth top sleeve 631 to push the extruded finished product 106 out of the sixth mold cavity 613.

[0054] The sixth upper mold 62 is provided with a pressing core 622 at one end near the sixth mold core 612. The pressing core 622 has a through hole in the center that communicates with the material discharge groove 621. The bottom surface of the pressing core 622 is provided with radial protrusions for forming radial embossing 1061.

[0055] This utility model is used for a cold heading leaf spring lifting lug bracket sleeve. Multi-stage dies are fixed to corresponding positions on a multi-station cold heading machine using locating pins and bolts. The central axis of each die coincides with the stamping axis of the cold heading machine, ensuring the coaxiality of the punch and ejector pin. The cold heading process includes the following steps: The first die: The clamps of the cold heading machine move the sheared metal billet 100 to the first die cavity 113. The inner diameter of the first die cavity 113 is the same as the outer diameter of the billet 100. The tip of the first punch 14 is tapered and pushes the billet 100 into the first die cavity 113. The first ejector pin 13 remains stationary, and the first punch 14 punches the billet 100. The first punch 14 and the first ejector pin 13 cooperate to form a first semi-finished billet 101 with upper positioning holes 1011 and lower positioning holes 1012 at both ends. The first upper die 12 retracts, and the first ejector pin 13 moves toward the first upper die 12, pushing the first semi-finished billet 101 out of the first die cavity 113.

[0056] The second die: The clamps of the cold heading machine move the first semi-finished blank 101 to the second die cavity 213, the inner diameter of the second die cavity 213 being the same as the outer diameter of the first semi-finished blank 101. The tip of the second punch 24 is tapered, pushing the first semi-finished blank 101 into the second die cavity 213. The second ejector pin 23 remains stationary, and the second punch 24 punches the first semi-finished blank 101, forming a first pre-heading hole 1021 at the upper end of the first semi-finished blank 101, thus forming the second semi-finished blank 102. The second upper die 22 retracts, and the second ejector pin 23 moves toward the second upper die 22, pushing the second semi-finished blank 102 out of the second die cavity 213.

[0057] The cold heading machine clamps flip the second semi-finished blank 102 and move it to the third mold cavity 313. At this time, the first pre-upsetting hole 1021 faces the third lower mold 31. The inner contour diameter of the third mold cavity 313 is the same as the outer diameter of the second semi-finished blank 102. The inner diameter of the third ejector pin 33 is the same as the upper inner diameter of the second pre-upsetting hole 1031. The top of the third punch 34 is conical and pushes the second semi-finished blank 102 into the third mold cavity 313. The third ejector pin 33 does not move. The third punch 34 punches the top of the second semi-finished blank 102. The third ejector pin 33 squeezes the bottom of the second pre-upsetting hole 1031 to form the second pre-upsetting hole 1031, thus forming the third semi-finished blank 103. The third upper mold 32 retracts, the third lower mold 31 separates from the third upper mold 32, the third push rod 37 pushes the third top sleeve 331, the third top sleeve 331 pushes the third semi-finished blank 103 out of the third mold cavity 313, while the third ejector pin 33 remains stationary.

[0058] The fourth die; the clamps of the cold heading machine move the third semi-finished blank 103 to the fourth die cavity 413, the inner diameter of the fourth die cavity 413 is the same as the outer diameter of the third semi-finished blank 103; the inner diameter of the fourth ejector pin 43 is the same as that of the second pre-heading hole 1031. The tip of the fourth punch 44 is conical, and pushes the third semi-finished blank 103 into the fourth die cavity 413. The fourth ejector pin 43 does not move, and the fourth punch 44 punches the top of the third semi-finished blank 103, forming a flange head 1041 on the top of the third semi-finished blank 103, forming the fourth semi-finished blank 104. The fourth upper die 42 retracts, the fourth lower die 41 separates from the fourth upper die 42, the fourth push rod 47 pushes the fourth top sleeve 431, the fourth top sleeve 431 pushes the fourth semi-finished blank 104 out of the fourth die cavity 413, while the fourth ejector pin 43 remains stationary.

[0059] The fifth die; the clamps of the cold heading machine move the fourth semi-finished blank 104 to the fifth die cavity 513. The inner diameter of the fifth die cavity 513 is the same as the outer diameter of the fourth semi-finished blank 104; the inner diameter of the fifth ejector pin 53 is the same as that of the second pre-upsetting hole 1031. The tip of the fifth punch 54 is conical and pushes the fourth semi-finished blank 104 into the fifth die cavity 513. The fifth ejector pin 53 remains stationary, and the fifth punch 54 punches the top of the fourth semi-finished blank 104 to form the upper pre-upsetting countersunk hole 1051, forming the fifth semi-finished blank 105. The fifth upper die 52 retracts, the fifth lower die 51 separates from the fifth upper die 52, the fifth push rod 57 pushes the fifth top sleeve 531, and the fifth top sleeve 531 pushes the fifth semi-finished blank 105 out of the fifth die cavity 513, while the fifth ejector pin 53 remains stationary.

[0060] The fifth mold; the clamps of the cold heading machine move the fifth semi-finished blank 105 to the sixth mold cavity 613. The inner diameter of the sixth mold cavity 613 is consistent with the diameter of the rod part of the fifth semi-finished blank 105. The flange head 1041 abuts against the top surface of the sixth mold core 612. The top of the sixth ejector pin 63 is conical and matches the second pre-upsetting hole 1031 of the fifth semi-finished blank 105. During cold heading, it moves axially along the second pre-upsetting hole 1031, upsetting the second pre-upsetting hole 1031 and the upper pre-upsetting countersunk hole 1051. The waste material is discharged from the discharge groove 621. At the same time, the radial protrusions on the bottom surface of the pressure core 622 of the sixth upper mold 62 press the top surface of the flange head 1041 to form radial embossing 1061. Then the sixth lower mold 61 and the sixth upper mold 62 separate, the sixth push rod 67 pushes the sixth top sleeve 631, the sixth top sleeve 631 pushes the rod of the finished product 106 out of the sixth mold cavity 613, while the sixth ejector pin 63 remains stationary to avoid damaging the stepped through hole structure of the finished product 106.

[0061] 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-upsetting die set for a leaf spring ear bracket sleeve, characterized by: The multi-stage molds, which are sequentially installed on the cold heading machine, include: A first-order mold (1) includes a first lower mold (11), a first upper mold (12), a first ejector pin (13), and a first punch (14); the first ejector pin (13) is slidably disposed in the first lower mold (11), and the first punch (14) is slidably disposed in the first upper mold (12); the first ejector pin (13) and the first punch (14) cooperate to press the two ends of the blank (100) placed in the first lower mold (11) to form a first semi-finished blank (101) having an upper positioning hole (1011) and a lower positioning hole (1012). The second-order mold (2) includes a second lower mold (21), a second upper mold (22), a second ejector pin (23), and a second punch (24). The second ejector pin (23) is slidably disposed in the second lower mold (21), and the second punch (24) is slidably disposed in the second upper mold (22). The second lower mold (21) is provided with a guide mechanism, and the second punch (24) is slidably connected to the second lower mold (21) through the guide mechanism. The second ejector pin (23) and the second punch (24) cooperate to extrude the top of the first semi-finished blank (101) placed in the second lower mold (21) to form a second semi-finished blank (102) with a first pre-forging hole (1021). The three-stage mold (3) includes a third lower mold (31), a third upper mold (32), a third ejector pin (33), and a third punch (34); the third ejector pin (33) is slidably disposed in the third lower mold (31), and the third punch (34) is slidably disposed in the third upper mold (32); the third ejector pin (33) and the third punch (34) cooperate to extrude the bottom end of the second semi-finished blank (102) placed in the third lower mold (31) after being flipped to form a third semi-finished blank (103) with a second pre-forging hole (1031). The four-stage mold (4) includes a fourth lower mold (41), a fourth upper mold (42), a fourth ejector pin (43), and a fourth punch (44); the fourth ejector pin (43) is slidably disposed in the fourth lower mold (41), and the fourth punch (44) is slidably disposed in the fourth upper mold (42); the fourth ejector pin (43) and the fourth punch (44) cooperate to shape the top of the third semi-finished blank (103) placed in the fourth lower mold (41) to form a fourth semi-finished blank (104) with a flange head (1041). The five-stage mold (5) includes a fifth lower mold (51), a fifth upper mold (52), a fifth ejector pin (53), and a fifth punch (54); the fifth ejector pin (53) is slidably disposed in the fifth lower mold (51), and the fifth punch (54) is slidably disposed in the fifth upper mold (52); the fifth ejector pin (53) and the fifth punch (54) cooperate to press the top of the fourth semi-finished blank (104) placed in the fifth lower mold (51) to form a fifth semi-finished blank (105) with an upper pre-upsetting countersunk hole (1051). The six-stage mold (6) includes a sixth lower mold (61), a sixth upper mold (62), and a sixth ejector pin (63); the sixth ejector pin (63) is slidably disposed in the sixth lower mold (61), and the sixth upper mold (62) is provided with a material discharge groove (621); the sixth ejector pin (63) and the sixth upper mold (62) cooperate to upset the upper pre-upsetting hole (1051) and the second pre-upsetting hole (1031) to form a finished product (106) with stepped through holes, and to form radial embossing (1061) on the top surface of the flange head (1041).

2. The cold upset die set for a leaf spring ear support sleeve of claim 1, wherein: The first lower mold (11) includes: a first main mold shell (111), one end of the first main mold shell (111) adjacent to the first upper mold (12) is connected to a first mold core (112), the first mold core (112) is provided with a first mold cavity (113), the first mold cavity (113) is used to place the blank (100); the first ejector pin (13) is installed on the lower side of the first mold cavity (113), the first ejector pin (13) and the first main mold shell (111) are slidably connected, and the top end of the first ejector pin (13) extends into the first mold cavity (113); the first ejector pin (13) Abutting the bottom end of the blank (100) in the first mold cavity (113), the first ejector pin (13) is used to extrude the bottom end of the blank (100) to form a first semi-finished blank (101) with a lower positioning hole (1012); the lower end of the first main mold shell (111) is equipped with a first pad (115), and the first ejector pin (13) is slidably connected in the through hole provided in the first pad (115); the outer periphery of the first ejector pin (13) is connected with a first slip ring (131), and the first slip ring (131) and the through hole provided in the first pad (115) are slidably engaged; The first upper die (12) includes a first die shell (121), and the first punch (14) is slidably connected in the first die shell (121). The first punch (14) is disposed opposite to the first die cavity (113). The bottom end of the first punch (14) presses against the top end of the blank (100) placed in the first die cavity (113) to form a first semi-finished blank (101) with an upper positioning hole (1011). The first mold core (112) includes a first upper mold core (1121) and a first lower mold core (1122). The first upper mold core (1121) has a first upper chamber along the center line, and the first lower mold core (1122) has a first lower chamber. The first upper chamber and the first lower chamber are connected to each other to form a first mold cavity (113).

3. The cold upset die set for a leaf spring ear support sleeve of claim 1, wherein: The second lower mold (21) includes: a second main mold shell (211), with a second mold core (212) connected to one end of the second main mold shell (211) adjacent to the second upper mold (22), and a second mold cavity (213) provided inside the second mold core (212), the second mold cavity (213) being used to place the first semi-finished blank (101); and a second ejector pin (23) installed on the lower side of the second mold cavity (213), the second ejector pin (23) being slidable from the second main mold shell (211). The second ejector pin (23) is connected to the second mold cavity (213) with its top end extending into the second mold cavity (213); the second ejector pin (23) abuts against the bottom end of the first semi-finished blank (101) inside the second mold cavity (213), and the second ejector pin (23) is used to push the extruded second semi-finished blank (102) out of the second mold cavity (213); the lower end of the second ejector pin (23) is connected to a second slip ring (231), and the second slip ring (231) is slidably connected inside the second main mold shell (211); The second upper die (22) includes a second die shell (221), the second punch (24) and the second die shell (221) are slidably connected, the second punch (24) is disposed opposite to the second die cavity (213); the bottom end of the second punch (24) presses the top end of the first semi-finished blank (101) placed in the second die cavity (213) to form a second semi-finished blank (102) with a first pre-upsetting hole (1021).

4. The cold upset die set for a leaf spring ear support sleeve of claim 3, wherein: The guiding mechanism includes a guide post (2231) arranged along the movement direction of the second punch (24); the lower end of the guide post (2231) is connected to the second die shell (221) through a flange (2232), and the second punch (24) is slidably connected in the through hole provided in the flange (2232); the top end of the guide post (2231) is connected to the second connecting block (2233); a punch sleeve (2234) is slidably connected to the outer periphery of the second connecting block (2233), the bottom end of the punch sleeve (2234) is connected to the pressure block (2235), and the pressure block (2235) is connected to the second punch (24).

5. The cold upset die set for a leaf spring ear support sleeve of claim 1, wherein: The third lower mold (31) includes: a third main mold shell (311), one end of which adjacent to the third upper mold (32) is connected to a third mold core (312), the third mold core (312) having a third mold cavity (313) for placing the second semi-finished blank (102); a third ejector pin (33) is installed on the lower side of the third mold cavity (313), the third ejector pin (33) and the third main mold shell (311) are slidably connected, the top end of the third ejector pin (33) extends into the third mold cavity (313); the third ejector pin (33) abuts against the second semi-finished blank (102) inside the third mold cavity (313); the third ejector pin (33) is covered with a third ejector sleeve. The third top sleeve (331) has a third ejector pin (33) extending out of the top of the third top sleeve (331), and a third pad (35) is connected to the bottom surface of the third top sleeve (331). The third ejector pin (33) is connected to a countersunk through hole provided in the third pad (35), and a third pad block (36) is connected to the bottom surface of the third pad (35). The third ejector pin (33) and the third pad block (36) abut against each other. A third push rod (37) is provided through the third pad block (36). The third push rod (37) passes through the third pad (35) and abuts against the bottom surface of the third top sleeve (331). The third push rod (37) is used to push the third top sleeve (331) to push the extruded third semi-finished blank (103) out of the third mold cavity (313). The third upper die (32) includes a third die shell (321), and the third punch (34) is slidably connected to the third die shell (321). The third punch (34) is arranged opposite to the third die cavity (313). The outer contour of the third punch (34) is adapted to the inner contour of the third die cavity (313). The third punch (34) slides along the third die cavity (313) during the cold heading process. The bottom end of the third punch (34) presses the top end of the first semi-finished blank (101) placed in the third die cavity (313). The third ejector pin (33) presses the bottom end of the second semi-finished blank (102) to form a third semi-finished blank (103) with a second pre-heading hole (1031).

6. The cold upset die set for a leaf spring ear holder sleeve of claim 1, wherein: The fourth lower mold (41) includes: a fourth main mold shell (411), one end of which adjacent to the fourth upper mold (42) is connected to a fourth mold core (412), the fourth mold core (412) having a fourth mold cavity (413) inside, the fourth mold cavity (413) for placing the third semi-finished blank (103); a fourth ejector pin (43) is installed on the lower side of the fourth mold cavity (413), the fourth ejector pin (43) and the fourth main mold shell (411) are slidably connected, the top end of the fourth ejector pin (43) extends into the fourth mold cavity (413); the fourth ejector pin (43) abuts against the third semi-finished blank (103) inside the fourth mold cavity (413); the fourth ejector pin (43) is covered with a fourth ejector sleeve (431), the fourth ejector pin (43) 43) A fourth top sleeve (431) extends out from the top, and a fourth pad (45) is connected to the bottom surface of the fourth top sleeve (431); the fourth ejector pin (43) is connected to the countersunk through hole provided in the fourth pad (45), and a fourth pad block (46) is connected to the bottom surface of the fourth pad (45). The fourth pad (45) is connected to the groove provided in the fourth pad block (46), and the fourth ejector pin (43) and the fourth pad block (46) abut against each other; a fourth push rod (47) is provided through the fourth pad block (46), and the fourth push rod (47) passes through the fourth pad (45) and abuts against the bottom surface of the fourth top sleeve (431). The fourth push rod (47) is used to push the fourth top sleeve (431) to push the extruded fourth semi-finished blank (104) out of the fourth mold cavity (413). The fourth mold core (412) includes a fourth upper mold core (4121) and a fourth lower mold core (4122). The fourth upper mold core (4121) has a fourth upper mold cavity along the center line, and the fourth lower mold core (4122) has a fourth lower mold cavity along the center line. The diameter of the fourth upper mold cavity is larger than that of the fourth lower mold cavity. The fourth upper mold cavity and the fourth lower mold cavity form a stepped fourth mold cavity (413). The fourth upper die (42) includes a fourth die shell (421), and the fourth punch (44) is slidably connected to the fourth die shell (421). The fourth punch (44) is arranged opposite to the fourth die cavity (413). The outer contour of the fourth punch (44) is adapted to the upper contour of the fourth die cavity (413). The fourth punch (44) slides along the upper end of the fourth die cavity (413) during the cold heading process. The fourth punch (44) presses the top of the third semi-finished blank (103) placed in the fourth die cavity (413) to form a fourth semi-finished blank (104) with a flange head (1041).

7. The cold upset die set for a leaf spring ear holder sleeve of claim 1, wherein: The fifth lower mold (51) includes: a fifth main mold shell (511), one end of which adjacent to the fifth upper mold (52) is connected to a fifth mold core (512), the fifth mold core (512) having a fifth mold cavity (513) inside, the fifth mold cavity (513) for placing the fourth semi-finished blank (104); a fifth ejector pin (53) is installed on the lower side of the fifth mold cavity (513), the fifth ejector pin (53) and the fifth main mold shell (511) are slidably connected, the top end of the fifth ejector pin (53) extends into the fifth mold cavity (513); the fifth ejector pin (53) abuts against the fourth semi-finished blank inside the fifth mold cavity (513). (104); The fifth ejector pin (53) is fitted with a fifth top sleeve (531), the top of the fifth ejector pin (53) extends out of the fifth top sleeve (531), and the bottom surface of the fifth top sleeve (531) is connected to a fifth pad plate (55); The fifth ejector pin (53) is connected to a countersunk through hole provided in the fifth pad plate (55), and the fifth pad plate (55) is fitted with a fifth push rod (57), which passes through the fifth pad plate (55) and abuts against the bottom surface of the fifth top sleeve (531). The fifth push rod (57) is used to push the fifth top sleeve (531) to push the extruded fifth semi-finished blank (105) out of the fifth mold cavity (513); The fifth mold core (512) includes a fifth upper mold core (5121) and a fifth lower mold core (5122). The fifth upper mold core (5121) has a fifth upper mold cavity along the center line, and the fifth lower mold core (5122) has a fifth lower mold cavity along the center line. The diameter of the fifth upper mold cavity is larger than that of the fifth lower mold cavity. The fifth upper mold cavity and the fifth lower mold cavity form a stepped fifth mold cavity (513). The fifth upper die (52) includes a fifth die shell (521), and the fifth punch (54) is slidably connected to the fifth die shell (521). The fifth punch (54) is arranged opposite to the fifth die cavity (513). The outer contour of the fifth punch (54) is adapted to the upper contour of the fifth die cavity (513). The fifth punch (54) slides along the upper end of the fifth die cavity (513) during the cold heading process. The fifth punch (54) presses the top of the fourth semi-finished blank (104) placed in the fifth die cavity (513) to form a fifth semi-finished blank (105) with an upper pre-heading countersunk hole (1051).

8. The cold upset die set for a leaf spring ear holder sleeve of claim 1, wherein: The sixth lower mold (61) includes: a sixth main mold shell (611), one end of which adjacent to the sixth upper mold (62) is connected to a sixth mold core (612), the sixth mold core (612) having a sixth mold cavity (613) inside, the sixth mold cavity (613) being used to place the fifth semi-finished blank (105); a sixth ejector pin (63) is installed on the lower side of the sixth mold cavity (613), the sixth ejector pin (63) and the sixth main mold shell (611) being slidably connected, the top end of the sixth ejector pin (63) extending into the sixth mold cavity (613); the sixth ejector pin (63) abuts against the fifth semi-finished blank (105) inside the sixth mold cavity (613); the sixth ejector pin (63) is covered with a sixth ejector sleeve (631), the top end of the sixth ejector pin (63) extending outwards. A sixth top sleeve (631) is provided, and a sixth pad (65) is connected to the bottom surface of the sixth top sleeve (631); a sixth ejector pin (63) is connected to a countersunk through hole provided in the sixth pad (65); a sixth pad block (66) is connected to the bottom surface of the sixth pad (65), and the sixth ejector pin (63) and the sixth pad block (66) abut against each other; a sixth push rod (67) is provided through the sixth pad block (66), and the sixth push rod (67) passes through the sixth pad (65) and abuts against the bottom surface of the sixth top sleeve (631); the sixth ejector pin (63) extrudes the fifth semi-finished blank (105) placed in the sixth mold cavity (613) to form a finished product (106), and the sixth push rod (67) is used to push the sixth top sleeve (631) to push the extruded finished product (106) out of the sixth mold cavity (613); The sixth upper mold (62) has a pressure core (622) at one end near the sixth mold core (612). The pressure core (622) has a through hole in the center that communicates with the material groove (621). The bottom surface of the pressure core (622) has radial protrusions for forming radial embossing (1061).

Images