Cold heading die for limiting bolt

Abstract

The utility model discloses a cold heading die for limit bolt, including first cold heading die set, second cold heading die set and third cold heading die set in proper order, first cold heading die set includes first fixed die (1) and first movable die (2), first fixed die (1) and first movable die (2) are used for extruding the end of bolt blank from cylindrical shape into block shape, first fixed die (1) and first movable die (2) are used for extruding the end of bolt blank into block shape, second fixed die (1) and second movable die (2) are used for extruding the end of bolt blank into block shape. The second cold heading module comprises a second fixed die (3) and a second movable die (4), the second fixed die (3) and the second movable die (4) are used for extruding the end part of the bolt blank from a block shape into a sheet shape with a step part, and the third cold heading module comprises a third fixed die (5) and a third movable die (6); and the third fixed die (5) and the third movable die (6) are used for cutting off the step part of the bolt blank, so that the end part of the bolt blank forms a limiting piece with a specified size. The limiting bolt cold heading forming device can achieve cold heading forming of the limiting bolt.

Description

Technical Field

[0001] This utility model relates to a mold for processing limit bolts, and more particularly to a cold heading mold for limit bolts. Background Technology

[0002] A limiting bolt is a new type of metal fitting, characterized by a thin, sheet-like limiting plate at its end, which secures the bolt during installation. Currently, manufacturers process limiting bolts by first forming a block-shaped cap at the bolt end, then cold-forging the cap directly into the mold cavity to obtain a limiting plate structure of specified thickness and size. However, this method has a drawback: due to the thinness of the limiting plate, the flowability of the cap area during cold forging is relatively reduced. This can lead to the cap not completely covering the edges of the mold cavity during cold forging, resulting in edge defects in the formed limiting plate.

[0003] Based on the above, if the bolt cap is first flattened to form a limiting piece using a cold heading die, and then the outer ring of the limiting piece is cut off, it is easy to cause deformation and damage to the limiting piece at the cut point. Furthermore, the outer ring of the limiting piece is prone to sticking onto the cold heading die after being cut off, making it impossible to remove, thus reducing its stability. Due to these process limitations, it is currently difficult for manufacturers to achieve cold heading of limiting bolts. Utility Model Content

[0004] The purpose of this invention is to provide a cold heading die for a limit bolt. It enables the cold heading of the limit bolt.

[0005] The technical solution of this utility model: A cold heading die for a limiting bolt, comprising a first cold heading die group, a second cold heading die group, and a third cold heading die group arranged sequentially. The first cold heading die group includes a first fixed die and a first movable die, which are used to extrude the end of the bolt blank from a cylindrical shape into a block shape. The second cold heading die group includes a second fixed die and a second movable die, which are used to extrude the end of the bolt blank from a block shape into a thin sheet shape with a stepped portion. The third cold heading die group includes a third fixed die and a third movable die, which are used to cut off the stepped portion of the bolt blank, so that the end of the bolt blank forms a limiting piece of a specified size.

[0006] The third movable mold includes a third movable frame, on which a pressure block is detachably connected. A pusher plate is sleeved on the outer side of the pressure block, and a cavity is formed on the inner side of the pressure block. A guide block that is fastened to the third movable frame is provided at the end of the pressure block away from the third fixed mold. A push rod is slidably connected to the inner side of the guide block. One end of the push rod extends into the cavity and is connected to the pusher plate via a transmission rod. The other end of the push rod extends into the inner side of the guide block and forms a push head. The push head and the guide block are connected to each other via a first elastic element. A drive block that is slidably connected to the third movable frame is provided on the outer side of the push head.

[0007] In the aforementioned cold heading die for a limiting bolt, the transmission rod is threadedly connected to the pusher plate, and the end of the transmission rod passes through the pressure block and is fastened to the top rod. The pressure block is provided with an elongated hole for the transmission rod to move horizontally.

[0008] In the aforementioned cold heading mold for limiting bolts, both the first fixed mold and the second fixed mold include a first fixed mold frame. One end of the first fixed mold frame is fixedly connected to a first fixed mold core. One side of the first fixed mold core is provided with a first extension rod that is slidably connected to the first fixed mold frame. A first fixed mold cavity for fastening and limiting the bolt blank is formed between the first extension rod and the first fixed mold core.

[0009] In the aforementioned cold heading mold for a limiting bolt, the first movable mold includes a first movable mold frame, one end of which is fixedly connected to a first movable mold core, and a pressure rod is slidably connected to the inner side of the first movable mold core. A first movable mold cavity for cold heading the end of the bolt blank is formed between the pressure rod and the first movable mold core.

[0010] In the aforementioned cold heading mold for a limiting bolt, the second movable mold includes a second movable mold frame, one end of which is fixedly connected to a second movable mold core. A second movable mold cavity is formed between the second movable mold cores for cold heading the end of the bolt blank. A step groove for forming a stepped portion is provided in the second movable mold cavity.

[0011] In the aforementioned cold heading die for a limiting bolt, the third fixing die includes a third fixing die frame, one end of which is fixedly connected to a cutting block, the inner side of which is slidably connected to a third fixing die core, the inner side of which is connected to the third fixing die frame via a second elastic element, the inner side of which is slidably connected to a third extension rod, and a third fixing die cavity for fastening and limiting the bolt blank is formed between the third extension rod and the third fixing die core, and a cutting groove for the pressure block to extend into is formed between the cutting block and the third fixing die core.

[0012] In the aforementioned cold heading die for a limiting bolt, a driving rod that is slidably connected to a third movable frame is provided on one side of the driving block. One end of the driving rod extends to the outside of the third movable frame. The third movable frame is provided with a limiting surface on the side away from the third fixed mold for limiting and pushing the driving rod.

[0013] Compared with the prior art, this utility model has the following characteristics:

[0014] (1) Through the structural cooperation of the first cold heading module, the second cold heading module and the third cold heading module, this utility model can first extrude the end of the bolt blank from a cylindrical shape into a block shape, then perform secondary processing on the block structure to form a thin sheet shape with a stepped part, and finally cut off the stepped part of the edge of the thin sheet to form a limiting piece of a specified size; under the above cooperation, on the one hand, the forming effect of the limiting piece can be improved, and on the other hand, the step part can be used to improve the cutting effect of the third cold heading module on the limiting piece, that is, reduce the possibility of deformation and damage to the cut surface;

[0015] (2) Based on the above, by limiting the structure of the third movable mold, when the pressure block cuts the stepped part of the bolt blank, the stepped part will be sleeved on the outside of the pressure block as the pressure block extends in; and when the pressure block moves and resets with the third movable frame, the drive block can push the push rod, so that the drive block overcomes the elastic force of the first elastic element and drives the push plate to push outward, thereby using the push plate to separate the stepped part sleeved on the outside of the pressure block, thus ensuring the continuous working stability of this utility model; furthermore, through the structural cooperation of the drive rod and the limiting surface, the limiting surface can also push out with the translation of the drive rod, so that this utility model can realize the pushing and resetting action of the push plate by relying only on the translation of the third movable mold, thus reducing the equipment cost of this utility model;

[0016] (3) By using the structural cooperation of the first movable mold core and the pressure rod in the first movable mold, when the end of the bolt blank is cold-forged, the first movable mold core and the first fixed mold core can first form a closed cavity by mutual contact, and then the end of the bolt blank can be deformed in the closed cavity by the extrusion of the pressure rod, thereby effectively preventing the end material from overflowing from the gap between the first movable mold core and the first fixed mold core during the deformation process, and improving the deformation effect of its end structure;

[0017] Therefore, this utility model can realize the cold heading of the limiting bolt. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the third active module;

[0020] Figure 3 This is a schematic diagram of the structure of the first fixed mold;

[0021] Figure 4 This is a schematic diagram of the structure of the first active module;

[0022] Figure 5 This is a schematic diagram of the structure of the second active module;

[0023] Figure 6 This is a structural schematic diagram of the third fixed mold;

[0024] Figure 7 This is a process flow diagram of this utility model;

[0025] Figure 8 This is a cold forging process diagram of the limit bolt for the limit plate.

[0026] The labels in the attached diagram are as follows: 1-First fixed mold, 2-First movable mold, 3-Second fixed mold, 4-Second movable mold, 5-Third fixed mold, 6-Third movable mold, 7-Third movable frame, 8-Pressure block, 9-Push plate, 10-Guide block, 11-Ejector rod, 12-Transmission rod, 13-First elastic element, 14-Drive block, 15-First fixed mold frame, 16-First fixed mold core, 17-First extension rod, 18-First movable mold frame, 19-First movable mold core, 20-Pressure rod, 21-Second movable mold frame, 22-Second movable mold core, 23-Step groove, 24-Third fixed mold frame, 25-Cutting block, 26-Third fixed mold core, 27-Second elastic element, 28-Third extension rod, 29-Drive rod, 30-Limiting surface, 111-Ejector head. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0028] Example. A cold heading die for a limiting bolt, configured as follows: Figure 1 As shown, the assembly includes a first cold heading module, a second cold heading module, and a third cold heading module arranged sequentially. The first cold heading module includes a first fixed mold 1 and a first movable mold 2, which are used to extrude the end of the bolt blank from a cylindrical shape into a block shape. The second cold heading module includes a second fixed mold 3 and a second movable mold 4, which are used to extrude the end of the bolt blank from a block shape into a thin sheet shape with a stepped portion. The third cold heading module includes a third fixed mold 5 and a third movable mold 6, which are used to cut off the stepped portion of the bolt blank, so that the end of the bolt blank forms a limiting piece of a specified size.

[0029] The third movable mold 6 includes a third movable frame 7, on which a pressure block 8 is fixed by a set screw. A pusher plate 9 is sleeved on the outer side of the pressure block 8, and a cavity is formed on the inner side of the pressure block 8. A guide block 10 is provided at the end of the pressure block 8 away from the third fixed mold 5, which is fastened to the third movable frame 7. A push rod 11 is slidably connected to the inner side of the guide block 10. One end of the push rod 11 extends into the cavity and is connected to the pusher plate 9 via a transmission rod 12. The other end of the push rod 11 extends into the inner side of the guide block 10 and forms a push head 111. The push head 111 and the guide block 10 are connected to each other by a first elastic element 13, which can be a compression spring. A drive block 14 is provided on the outer side of the push head 111, which is slidably connected to the third movable frame 7. The end of the drive block 14 is in contact with the push head 111.

[0030] The transmission rod 12 is threaded onto the pusher plate 9. The end of the transmission rod 12 passes through the pressure block 8 and is fastened to the top rod 11. The pressure block 8 is provided with an elongated hole for the transmission rod 12 to move horizontally. The manufacturer may also choose a cotter pin to replace the transmission rod 12 to achieve the transmission function as needed.

[0031] The first fixed mold 1 and the second fixed mold 3 both include a first fixed mold frame 15. One end of the first fixed mold frame 15 is fixedly connected to a first fixed mold core 16. A first extension rod 17 is provided on one side of the first fixed mold core 16, which is slidably connected to the first fixed mold frame 15. The inner side of the first extension rod 17 is connected to a driving member and is used to push the bolt blank outward. A first fixed mold cavity is formed between the first extension rod 17 and the first fixed mold core 16 for fastening and limiting the bolt blank.

[0032] The first movable mold 2 includes a first movable mold frame 18, one end of which is fixedly connected to a first movable mold core 19. A pressure rod 20 is slidably connected to the inner side of the first movable mold core 19. A driving component is connected to the inner side of the pressure rod 20 and it is used to extrude and form the end of the bolt blank. A first movable mold cavity is formed between the pressure rod 20 and the first movable mold core 19 for cold heading the end of the bolt blank.

[0033] The second movable mold 4 includes a second movable mold frame 21, one end of which is fixedly connected to a second movable mold core 22. A second movable mold cavity is formed between the second movable mold cores 22 for cold heading the end of the bolt blank. A step groove 23 for forming a step portion is provided in the second movable mold cavity.

[0034] The third fixed mold 5 includes a third fixed mold frame 24. A cutting block 25 is fixedly connected to one end of the third fixed mold frame 24. A third fixed mold core 26 is slidably connected to the inner side of the cutting block 25. The inner side of the third fixed mold core 26 is connected to the third fixed mold frame 24 via a second elastic element 27, which can be a compression spring. A third extension rod 28 is slidably connected to the inner side of the third fixed mold core 26. A driving element is connected to the inner side of the third extension rod 28 and it is used to push the bolt blank outward. A third fixed mold cavity is formed between the third extension rod 28 and the third fixed mold core 26 for locking and limiting the bolt blank. A cutting groove is formed between the cutting block 25 and the third fixed mold core 26 for the pressure block 8 to extend into.

[0035] The drive block 14 has a drive rod 29 that is slidably connected to the third movable frame 7 on one side. One end of the drive rod 29 extends to the outside of the third movable frame 7. The third movable frame 7 has a limiting surface 30 on the side away from the third fixed mold 5 for limiting and pushing the drive rod 29.

[0036] The working principle of this utility model is as follows: In use, the bolt blank is first processed by the first fixed mold 1 and the first movable mold 2. Under the pressure of the pressure rod 20, the end of the bolt blank changes from a cylindrical shape to a block structure. After cold heading by the first cold heading mold, the bolt blank enters the second cold heading mold. The end of the bolt blank undergoes secondary cold heading through the cooperation of the second fixed mold 3 and the second movable mold 4, causing the block structure at the end to be compressed by the second movable mold core 22 into a thin sheet structure with steps. After processing by the second cold heading mold, the bolt blank enters the third cold heading mold. The cooperation of the pressure block 8, the cutting block 25, and the third fixed mold core 26 cuts off the steps on the outside of the bolt blank, pressing the bolt blank along with the end limiting piece into the cutting groove. The annular step, after being cut, is then fitted onto the outside of the pressure block 8.

[0037] After the third movable mold 6 completes the cutting action, it retracts towards the limiting surface 30. During the retraction of the third movable mold 6, the limiting surface 30 presses against the drive rod 29, causing the drive rod 29 to exert an outward pressing force on the ejector rod 11 via the drive block 14, thereby ejecting the ejector rod 11 towards the third fixed mold 5. After ejection, the ejector rod 11 drives the pusher plate 9 to perform a synchronous ejection action via the transmission rod 12, and the pusher plate 9 removes material from the annular step sleeved on the outside of the pressure block 8 after ejection. When the third movable mold 6 moves back towards the third fixed mold 5, the rebound action of the first elastic element 13 can drive the pusher plate 9 and the drive rod 29 to move and reset respectively, thereby ensuring the subsequent working stability of the third movable mold 6.

Claims

1. A cold heading die for a limiting bolt, characterized in that: The assembly includes a first cold heading module, a second cold heading module, and a third cold heading module arranged sequentially. The first cold heading module includes a first fixed mold (1) and a first movable mold (2), which are used to extrude the end of the bolt blank from a cylindrical shape into a block shape. The second cold heading module includes a second fixed mold (3) and a second movable mold (4), which are used to extrude the end of the bolt blank from a block shape into a thin sheet shape with a stepped portion. The third cold heading module includes a third fixed mold (5) and a third movable mold (6), which are used to cut off the stepped portion of the bolt blank, so that the end of the bolt blank forms a limiting piece of a specified size. The third movable mold (6) includes a third movable frame (7), on which a pressure block (8) is detachably connected. A pusher plate (9) is sleeved on the outer side of the pressure block (8), and a cavity is formed on the inner side of the pressure block (8). A guide block (10) is provided at the end of the pressure block (8) away from the third fixed mold (5) and is fastened to the third movable frame (7). A top rod (11) is slidably connected to the inner side of the guide block (10). One end of the top rod (11) extends into the cavity and is connected to the pusher plate (9) via a transmission rod (12). The other end of the top rod (11) extends into the inner side of the guide block (10) and forms a top head (111). The top head (111) and the guide block (10) are connected to each other via a first elastic element (13). A drive block (14) that is slidably connected to the third movable frame (7) is provided on the outer side of the top head (111).

2. The cold heading die for a limiting bolt according to claim 1, characterized in that: The transmission rod (12) is threaded onto the pusher plate (9). The end of the transmission rod (12) passes through the pressure block (8) and is fastened to the top rod (11). The pressure block (8) is provided with an elongated hole for the transmission rod (12) to move horizontally.

3. The cold heading die for a limiting bolt according to claim 1, characterized in that: The first fixed mold (1) and the second fixed mold (3) both include a first fixed mold frame (15). One end of the first fixed mold frame (15) is fixedly connected to a first fixed mold core (16). One side of the first fixed mold core (16) is provided with a first extension rod (17) that is slidably connected to the first fixed mold frame (15). A first fixed mold cavity for fastening and limiting the bolt blank is formed between the first extension rod (17) and the first fixed mold core (16).

4. The cold heading die for a limiting bolt according to claim 1, characterized in that: The first movable mold (2) includes a first movable mold frame (18), one end of which is fixedly connected to a first movable mold core (19), and a pressure rod (20) is slidably connected to the inner side of the first movable mold core (19). A first movable mold cavity for cold heading of the end of the bolt blank is formed between the pressure rod (20) and the first movable mold core (19).

5. The cold heading die for a limiting bolt according to claim 1, characterized in that: The second movable mold (4) includes a second movable mold frame (21), one end of which is fixedly connected to a second movable mold core (22). A second movable mold cavity is formed between the second movable mold cores (22) for cold heading the end of the bolt blank. A step groove (23) for forming a step portion is provided in the second movable mold cavity.

6. The cold heading die for a limiting bolt according to claim 1, characterized in that: The third fixed mold (5) includes a third fixed mold frame (24), one end of which is fixedly connected to a cutting block (25), and the inner side of the cutting block (25) is slidably connected to a third fixed mold core (26). The inner side of the third fixed mold core (26) is connected to the third fixed mold frame (24) via a second elastic element (27). The inner side of the third fixed mold core (26) is slidably connected to a third extension rod (28). A third fixed mold cavity for fastening and limiting the bolt blank is formed between the third extension rod (28) and the third fixed mold core (26). A cutting groove for the pressure block (8) to extend into is formed between the cutting block (25) and the third fixed mold core (26).

7. A cold heading die for a limiting bolt according to claim 1, characterized in that: The drive block (14) has a drive rod (29) that is slidably connected to the third movable frame (7) on one side. One end of the drive rod (29) extends to the outside of the third movable frame (7). The third movable frame (7) has a limiting surface (30) on the side away from the third fixed mold (5) for limiting and pushing the drive rod (29).

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