Trimming die for cold heading fastener

Abstract

The utility model provides a cold heading fastener trimming die which comprises a stamping die body and a main die body which are opened and closed front and back, an annular trimming stamping die is embedded in the rear end of the stamping die body, an annular trimming top die corresponding to the trimming stamping die is embedded in the front end of the main die body, a bolt rod portion inserting hole is formed in the front end of the main die body, and a bolt rod portion inserting hole is formed in the rear end of the main die body. A containing cavity with an opening in the rear end is formed in the punching die body, a punching rod is fixedly arranged at the front end of the cavity wall of the containing cavity, the punching rod is sequentially sleeved with a belleville spring and a movable sleeve from front to back, and the belleville spring is arranged between the front end of the cavity wall of the containing cavity and the front end of the movable sleeve in a supported mode. The trimming stamping die is fixedly arranged at the rear end of the movable sleeve with the same hole center; and when the punching die body is in the initial position, a movable gap exists between the rear end face of the punching rod and the rear end face of the trimming punching die. The trimming die for the cold heading fastener is suitable for trimming overlong and overthin rod bolts.

Description

Technical Field

[0001] The utility model relates to the technical field of molds, in particular to a cold heading fastener trimming mold. Background Art

[0002] Bolts, as a common fastener, are widely used in various machinery, equipment, vehicles, ships and other fields. Most of the bolts on the market are manufactured by cold heading process. However, during the cold heading process, due to the presence of a certain gap in the mold, the bolt will be pressed into the gap, and eventually burrs will form on the edge of the bolt head. Machining is required to remove the burrs during use, which is time-consuming and labor-intensive. The cold heading machine is a special equipment specially used for mass production of fasteners. It can sequentially complete the processes of cutting, heading, forming, chamfering, thread rolling, diameter reduction and trimming.

[0003] In order to cut off the flash of the bolt head, a special die needs to be installed on the cold heading machine. Existing cold heading fastener trimming dies, such as Figure 1 As shown, it includes a movable mold 91 and a fixed mold 92 that open and close front and back. The front end surface of the fixed mold 92 is provided with a placement hole 921 for inserting the rod of the bolt 90, and a push rod 922 is inserted into the placement hole 921 from the rear end. The rear end surface of the movable mold 91 is provided with a discharge channel 911 for the bolt head of the trimming bolt 90 to enter, and a drop port 912 connected to the discharge channel 911 is provided on the front side wall of the movable mold 91. At the same time, a first trimming cutter head 913 is embedded in the rear end of the movable mold 91, and a second trimming cutter head 923 corresponding to the first trimming cutter head 913 is embedded in the front end of the fixed mold 92. When in use, the movable mold 91 is opened relative to the fixed mold 92, and the rod of the bolt 90 is inserted into the placement hole 921. Hole 921, the movable mold 91 is closed relative to the fixed mold 92, and the flash on the bolt head of the bolt 90 is squeezed and cut off by the first trimming head 913 and the second trimming head 923. Then, the bolt 90 is pushed into the discharge channel 911 by the push rod 922 and dropped out from the drop port 912. In this process, the push rod 922 will tear off the flash that is not completely removed and is still adhered to the bolt head of the bolt 90. This trimming structure has the advantages of simple structure, high trimming finish, and easy debugging, but has the following disadvantages: First, when the bolt rod is too long, it cannot fall out of the drop port. Second, when the push rod pushes the bolt into the drop port, if the bolt rod is too thin, the push rod will easily bend and deform the too thin rod.

[0004] Therefore, designing a cold heading and trimming die suitable for trimming bolts with overly long and thin rods is a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0005] The purpose of the utility model is to provide a cold heading fastener trimming die which can overcome the defects of the prior art and is suitable for trimming bolts with overlong or overthin shanks, so as to solve the problem that the prior art cannot trim bolts with overlong or overthin shanks.

[0006] In order to solve the above problems, the utility model provides a cold heading fastener trimming die, comprising a die body and a main die body that open and close front and back, an annular trimming die is embedded in the rear end of the die body, an annular trimming top die corresponding to the trimming die is embedded in the front end of the main die body, a bolt rod insertion hole is provided at the front end of the main die body, a push pin is inserted into the bolt rod insertion hole from the rear end, a cavity with a rear end opening is provided inside the die body, a punch rod is fixedly provided at the front end of the cavity wall of the cavity, a disc spring and a movable sleeve are sequentially sleeved on the punch rod from front to back, the disc spring support is provided between the front end of the cavity wall of the cavity and the front end of the movable sleeve, the trimming die is fixed at the rear end of the movable sleeve with the same hole center; when the die body is in the initial position, there is a movable gap between the rear end face of the punch rod and the rear end face of the trimming die.

[0007] Compared with the existing technology, the advantages of the present invention are as follows: by providing an ejector pin between the punch die and the main die body, and performing the action of ejecting the bolt from the bolt shank insertion hole while the die is open, the present invention avoids the problem of the bolt shank being too long and thus being unable to be removed from the die; in addition, the present invention applies force to the bolt head through the punch rod, tearing off the burrs that have not been completely removed and are still adhered to the bolt head, thus avoiding the problem of extrusion deformation caused by the excessively thin bolt shank in the traditional method. Therefore, the present invention is suitable for cold heading and trimming of bolts with excessively long and thin shanks, and has the advantages of a wide range of applications, simple operation, and high trimming efficiency.

[0008] As an improvement, an anti-slip mechanism is provided between the die body and the movable sleeve to prevent the sleeve from escaping from the rear opening of the cavity. The anti-slip mechanism comprises an anti-slip groove extending forward and backward along the sidewalls of the movable sleeve, and a stopper fixed to the cavity wall and slidingly positioned within the anti-slip groove. This anti-slip mechanism effectively prevents the movable sleeve from falling out of the cavity during the mold opening process due to the excessive rebound force of the disc spring, ensuring the stability and reliability of the trimming process and thereby improving the overall performance of the trimming die.

[0009] As an improvement, a stress sleeve is embedded in the main mold body and the trimming top mold to create an interference fit. This structure effectively secures the trimming top mold to the main mold body, preventing it from loosening or falling off during the trimming process, ensuring stability and reliability. Furthermore, the stress sleeve effectively improves the trimming top mold's impact resistance and extends its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the overall structure of a cold heading fastener trimming die in the prior art;

[0011] Figure 2 It is a schematic diagram of the overall structure of the utility model.

[0012] Description of reference numerals:

[0013] 1. Die body; 10. Cavity; 2. Main die body; 20. Bolt shank insertion hole; 3. Trimming die; 4. Trimming ejector die; 40. Stress sleeve; 5. Ejector pin; 6. Punch rod; 7. Disc spring; 8. Movable sleeve; 81. Anti-slip groove; 82. Stopper. DETAILED DESCRIPTION

[0014] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0015] like Figure 2 As shown, in the utility model, the cold heading fastener trimming die comprises a die body 1 and a main die body 2 which open and close front and back, an annular trimming die 3 is embedded in the rear end of the die body 1, an annular trimming top die 4 which is arranged corresponding to the trimming die 3 is embedded in the front end of the main die body 2, a bolt rod insertion hole 20 is provided at the front end of the main die body 2, a ejector pin 5 is inserted into the bolt rod insertion hole 20 from the rear end, a cavity 10 with a rear end opening is provided inside the die body 1, a punch rod 6 is fixedly provided at the front end of the cavity wall of the cavity 10, a disc spring 7 and a movable sleeve 8 are sequentially sleeved on the punch rod 6 from front to back, the disc spring 7 is supported and arranged between the front end of the cavity wall of the cavity 10 and the front end of the movable sleeve 8, the trimming die 3 is fixed at the rear end of the movable sleeve 8 concentrically; when the die body 1 is in the initial position, there is a movable gap between the rear end face of the punch rod 6 and the rear end face of the trimming die 3.

[0016] The working principle of the present utility model is as follows: when the die body 1 is in the initial position, there is a movable gap between the rear end face of the punch rod 6 and the rear end face of the trimming die 3; during the trimming operation, the die body 1 moves toward the main die body 2 to close the mold, and the trimming die 3 and the trimming top die 4 squeeze each other to cut off the flash of the bolt head. At the same time, the compression disc spring 7 of the trimming die 3 shortens the movable gap between the rear end face of the punch rod 6 until the bolt head and the rear end of the punch rod 6 abut. At this time, the punch rod 6 applies a reverse force to the bolt head to tear off the flash that has not been completely removed and is still attached to the bolt head. Subsequently, the die body 1 moves in the opposite direction to open the mold, and the bolt with the flash cut off is ejected from the bolt rod socket 20 by means of the ejector pin 5.

[0017] The present invention provides an ejector pin 5 between the punch die 1 and the main die 2, and performs the action of ejecting the bolt from the bolt shank insertion hole 20 while the die is open. This avoids the problem of the bolt shank being too long and thus being unable to be removed from the die. Furthermore, the present invention applies force to the bolt head through the punch 6, tearing off the burrs that have not been completely removed and are still attached to the bolt head, thus avoiding the problem of extrusion deformation caused by the thinness of the bolt shank in the traditional method. Therefore, the present invention is suitable for cold heading and trimming of bolts with excessively long and thin shanks, and has the advantages of a wide range of applications, ease of operation, and high trimming efficiency.

[0018] like Figure 2 As shown, an anti-slip mechanism is provided between the die body 1 and the movable sleeve 8 to prevent the movable sleeve 8 from escaping from the rear end opening of the cavity 10. The anti-slip mechanism includes an anti-slip groove 81 extending forward and backward on the side wall of the movable sleeve 8, and a stopper 82 fixed to the cavity wall of the cavity 10 and slidably disposed within the anti-slip groove 81. This anti-slip mechanism effectively prevents the movable sleeve 8 from falling out of the cavity 10 due to the excessive rebound force of the disc spring 7 during the mold opening process, thereby ensuring the stability and reliability of the trimming process and thereby improving the overall performance of the trimming die.

[0019] like Figure 2 As shown, a stress sleeve 40 is embedded in the main mold body 2 and the trimming top mold 4 to form an interference fit. With this structure, the stress sleeve 40 effectively secures the trimming top mold 4 to the main mold body 2, preventing it from loosening or falling off during the trimming process, ensuring stability and reliability of the trimming process. Furthermore, the presence of the stress sleeve 40 effectively improves the impact resistance of the trimming top mold 4, extending its service life.

[0020] Although the disclosure is as described above, the scope of protection of the disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the scope of protection of the utility model.

Claims

1. A cold heading fastener trimming die, comprising a die body (1) and a main die body (2) that open and close front and back, wherein an annular trimming die (3) is embedded in the rear end of the die body (1), and an annular trimming top die (4) corresponding to the trimming die (3) is embedded in the front end of the main die body (2), a bolt shank insertion hole (20) is opened at the front end of the main die body (2), and a thimble (5) is inserted into the bolt shank insertion hole (20) from the rear end, characterized in that: A cavity (10) with a rear end opening is provided inside the die body (1), a punch rod (6) is fixedly provided at the front end of the cavity wall of the cavity (10), a disc spring (7) and a movable sleeve (8) are sequentially sleeved on the punch rod (6) from front to back, the disc spring (7) is supported and arranged between the front end of the cavity wall of the cavity (10) and the front end of the movable sleeve (8), and the trimming die (3) is fixedly arranged at the rear end of the movable sleeve (8) with the center of the hole; when the die body (1) is in the initial position, a movable gap exists between the rear end face of the punch rod (6) and the rear end face of the trimming die (3).

2. The cold heading fastener trimming die according to claim 1, characterized in that: An anti-slip mechanism is provided between the die body (1) and the movable sleeve (8) for limiting the movable sleeve (8) from being detached from the rear end opening of the cavity (10). The anti-slip mechanism comprises an anti-slip groove (81) extending forward and backward on the side wall of the movable sleeve (8) and a stopper (82) fixedly provided on the cavity wall of the cavity (10) and slidably provided in the anti-slip groove (81).

3. The cold heading fastener trimming die according to claim 1, characterized in that: A stress sleeve (40) is embedded in the main mold body (2) and the trimming top mold (4) in an interference fit.

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