Cold heading forming die for producing pressing rivet nuts
By combining the mold design of the workstations and the ejector pin push structure, the problems of high mold costs and poor equipment adaptability in the production of press-fit nuts have been solved, thereby improving equipment compatibility and product yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-05
- Publication Date
- 2026-03-17
AI Technical Summary
In the current production of press-fit nuts, each station requires an independent mold, which increases mold costs. Different models or specifications of cold heading equipment are difficult to adapt to processing needs, limiting the flexibility and scalability of production.
Design a cold heading die for producing press-fit nuts. By merging the dies of two stations, the upper punch moves in the opposite direction to exit the main die, and the ejector pin pushes the straight tube to remove the finished nut body from the main die, reducing die costs. The machining accuracy and stability are improved by using structures such as limit pads, punch sleeves, and spring blocks.
It reduces the requirements for cold heading equipment, improves equipment compatibility and product yield, reduces mold costs, and enhances production flexibility and scalability.
Smart Images
Figure CN223997219U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of press-fit nut manufacturing technology, and in particular to a cold heading mold for producing press-fit nuts. Background Technology
[0002] Press-fit nuts, also known as rivet nuts or self-locking nuts, are a type of nut used on thin plates or sheet metal. They are round in shape with knurled teeth and guide grooves at one end. They are manufactured using cold heading dies. In practical applications, cold heading dies typically require the following technologies:
[0003] 1. The upper die part is used to stamp the raw material;
[0004] 2. The lower die part, in conjunction with the punch, shapes the raw material;
[0005] 3. Ejection mechanism: After cold heading, the formed self-piercing rivet is ejected from the die cavity;
[0006] The processed raw materials are placed into a cold heading mold, which is usually composed of an upper mold and a lower mold. The upper mold and the lower mold form a rivet shape. Through the pressure of the cold heading machine, the raw materials are cold-headed in the mold, gradually deforming the raw materials into the shape of a rivet.
[0007] Multi-station cold heading machines contain multiple independent functional components or high-precision components. Due to the large number of stations, each station requires an independent mold, which increases mold costs. Different models or specifications of cold heading equipment are difficult to adapt to the processing requirements of the mold and can only process blanks of specific specifications, which limits the flexibility and scalability of production. Utility Model Content
[0008] To address the shortcomings of existing technologies, this utility model provides a cold heading forming mold for the production of press-fit nuts, solving the technical problems of each station requiring an independent mold, leading to increased mold costs, and the difficulty for different models or specifications of cold heading equipment to adapt to the processing requirements of the mold, which can only process blanks of specific specifications, thus limiting the flexibility and scalability of production.
[0009] To achieve the above objectives, this utility model provides the following technical solution:
[0010] A cold heading die for producing a press-fit nut includes an upper punch, a nut body, a main module, and a main mold shell. The main module is sleeved on the side end of the main mold shell. The nut body and the side end of the main module are aligned on the axis. A limiting pad for mating installation is installed inside the main mold shell. A push tube pad for guiding movement is fixedly installed inside the limiting pad. A punch body is slidably installed inside the push tube pad.
[0011] Preferably, a straight push tube aligned with the axis of the push tube pad is fixedly installed at the side end of the push tube pad, and the interior of the straight push tube is slidably connected to the punch body;
[0012] The limiting pad is provided with multiple telescopic spring blocks inside, and one end of each spring block is connected to the inside of the limiting pad.
[0013] The main mold shell has a punch sleeve fixedly installed inside to guide the movement of the punch body, and one side of the punch sleeve has a recessed design.
[0014] Preferably, a punch pad is provided at the side end of the punch sleeve, and a protrusion is provided at the side end of the punch pad to mate with the side end of the punch sleeve. A pin for mate fixing is provided on the outer side of the punch pad.
[0015] The surface of the nut body is provided with knurled teeth and guide grooves.
[0016] Compared with the prior art, the present invention has the following beneficial effects;
[0017] In this invention, the upper punch retracts from the main mold via its reverse movement. After the upper punch retracts from the main mold, the ejector pin begins to function, pushing the straight tube pusher pad, which in turn moves the straight tube pusher towards the mold opening, thus removing the finished nut body from the main mold. This facilitates the processing of the next nut body. The push of the ejector pin drives the straight tube pusher to move, transmitting the ejector pin's thrust to the straight tube pusher and ensuring that the straight tube pusher can smoothly push out the nut body. This reduces the requirements of the cold heading equipment for the press-fit nut and improves the equipment's compatibility. At the same time, by merging the molds of two stations, the mold cost of one station is reduced.
[0018] In this invention, the punch sleeve fixes and protects the punch, ensuring its stability and positional accuracy during the punching process. The punch pad provides support or cushioning during punching, reducing vibration and wear. The limiting pad prevents the embossed teeth on the nut body from failing to contact the die bottom plane before forming the guide groove of the rivet nut due to jamming, thus avoiding out-of-tolerance upper diameter of the guide groove and improving the product yield. Attached Figure Description
[0019] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings.
[0020] Figure 1 This is a structural diagram of the main module of this utility model;
[0021] Figure 2 This is a structural diagram of the limiting pad of this utility model;
[0022] Figure 3 This is a structural diagram of the main mold shell of this utility model;
[0023] Figure 4 This is a structural diagram of the nut body of this utility model.
[0024] Legend: 11. Upper punch; 12. Nut body; 13. Main module; 14. Main mold shell; 15. Punch body; 16. Spring block; 17. Straight tube push tube; 18. Limiting pad; 19. Push tube pad; 21. Punch sleeve; 22. Punch pad block; 23. Ejector pin. Detailed Implementation
[0025] This application provides a cold heading forming mold for producing press-fit nuts, effectively solving the problem of each station requiring an independent mold, leading to increased mold costs. Different models or specifications of cold heading equipment are difficult to adapt to the processing requirements of this mold, limiting the processing of only specific specifications of blanks and restricting production flexibility and scalability. The upper punch moves in the reverse direction to exit the main mold. After the upper punch exits the main mold, the ejector pin begins to function, pushing the straight tube pusher pad, which in turn moves the straight tube pusher towards the mold opening, ejecting the processed nut body from the main mold, facilitating the processing of the next nut body. The ejector pin pushes the straight tube pusher, transmitting the ejector pin's thrust to the straight tube pusher, ensuring the straight tube pusher can smoothly eject the nut body. This reduces the requirements of the cold heading equipment for press-fit nuts, improves equipment compatibility, and reduces the mold cost of one station by merging the molds of two stations.
[0026] Example
[0027] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the technical solution in this application embodiment effectively solves the technical problem that each workstation requires an independent mold, leading to increased mold costs. Furthermore, different models or specifications of cold heading equipment are difficult to adapt to the processing requirements of the mold, limiting the processing of blanks of specific specifications and restricting production flexibility and scalability. The overall approach is as follows:
[0028] To address the problems existing in the prior art, this utility model provides a cold heading forming mold for producing press-fit nuts, including an upper punch 11, a nut body 12, a main module 13, and a main mold shell 14. The main module 13 is sleeved on the side end of the main mold shell 14. The axial direction of the nut body 12 and the side end of the main module 13 are aligned. A limiting pad 18 for docking installation is installed inside the main mold shell 14. The main mold shell 14 fixes and protects the main mold, provides support for the main mold, and ensures the stability and positional accuracy of the main mold during processing. Throughout the process, the upper punch 11 provides power for the movement of the nut body 12, assisting in completing the punching and guide groove forming operations.
[0029] The limiting pad 18 has a push tube pad 19 for guiding movement fixedly installed inside. The push tube pad 19 has a punch body 15 slidably installed inside. The side end of the push tube pad 19 has a straight tube 17 aligned with the axis of the push tube pad 19 fixedly installed. The inside of the straight tube 17 is slidably connected to the punch body 15, pushing the straight tube 17 pad, thereby causing the straight tube 17 to move towards the die opening, and removing the machined nut body 12 from the main die.
[0030] The surface of the nut body 12 is provided with embossed teeth and guide grooves. The interior of the limiting pad 18 is provided with multi-segment telescopic spring blocks 16. One end of the spring block 16 is connected to the interior of the limiting pad 18. Through the elastic force of the spring block 16, the embossed teeth of the nut body 12 are always in contact with the bottom plane of the main module 13.
[0031] The main mold shell 14 has a punch sleeve 21 fixedly installed inside to guide the movement of the punch body 15, fix the punch body 15, and ensure the stability and positional accuracy of the punch body 15 during the punching process.
[0032] One side of the punch sleeve 21 is recessed. A punch pad 22 is provided at the side end of the punch sleeve 21. A protrusion is provided at the side end of the punch pad 22 to mate with the side end of the punch sleeve 21. An ejector pin 23 for docking and fixing is provided on the outside of the punch pad 22 to provide support for the punch body 15, reduce the vibration and wear of the punch body 15 during the punching process, provide power to push out the nut body 12, and assist in completing the demolding operation of the nut body 12.
[0033] Working principle:
[0034] In the first step, the upper punch 11 pushes the nut body 12 toward the main mold. During this process, the nut body 12 moves under the drive of the upper punch 11, and its embossed teeth first contact the bottom plane of the main mold. When the embossed teeth on the nut body 12 touch the bottom plane of the main mold, the main mold moves backward under the push of the nut body 12. At the same time, due to the elastic force of the spring, the embossed teeth of the nut body 12 are always in close contact with the bottom plane of the main mold, ensuring the processing accuracy. When the nut body 12 continues to move and touches the punch, the punching begins. With the further movement of the upper punch 11 and the nut body 12, the punching operation is completed. The upper punch 11 continues to drive the nut body 12 and the main mold to move. When the punching is about to be completed, it will also drive the nut body 12 to form the guide groove. After these operations are completed, the upper punch 11 moves in the opposite direction to exit the main mold. After the upper punch 11 exits the main mold, the ejector pin 23 begins to play its role, pushing the straight tube pusher 17 to move towards the mold opening, and taking the processed nut body 12 out of the main mold, so that the next nut body 12 can be processed. Under the push of the ejector pin 23, the straight tube pusher 17 is driven to move, which plays the role of transmitting the thrust of the ejector pin 23 to the straight tube pusher 17, ensuring that the straight tube pusher 17 can smoothly push out the nut body 12.
[0035] In the second step, the punch sleeve 21 fixes and protects the punch, ensuring its stability and positional accuracy during the punching process. The punch pad 22 provides support or cushioning during punching, reducing vibration and wear. The limiting pad 18 prevents the embossed teeth on the nut body 12 from failing to contact the bottom plane of the die before forming the guide groove of the press-fit nut due to jamming, thus avoiding out-of-tolerance upper diameter of the guide groove and improving the product yield. The main die shell 14 fixes and protects the main die, providing support and ensuring its stability and positional accuracy during processing. Throughout the process, the upper punch 11 provides power for the movement of the nut body 12, assisting in completing the punching and guide groove forming operations. The main die provides the mold for the punching and guide groove forming operations of the nut body 12, and works with the upper punch 11 to complete the processing of the press-fit nut.
[0036] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.
Claims
1. A production cold upset forming die for a press-in nut, comprising an upper punch rod (11), a nut body (12), a main die block (13) and a main die shell (14), characterized in that, The main module (13) is sleeved at the side end of the main mold shell (14), the nut body (12) is aligned with the axis of the side end of the main module (13), the inside of the main mold shell (14) is provided with a limiting pad (18) for butt joint installation, the inside of the limiting pad (18) is fixedly provided with a push tube pad (19) for guiding movement, and the inside of the push tube pad (19) is slidably provided with a punch body (15).
2. A cold upset forming die for producing a press-in nut according to claim 1, wherein The side end of the push tube pad (19) is fixedly provided with a straight cylinder push tube (17) aligned with the axis of the push tube pad (19), and the inside of the straight cylinder push tube (17) is slidably connected with the punch body (15).
3. A cold upset forming die for producing a press-in nut according to claim 1, wherein The inside of the limiting pad (18) is provided with a plurality of stretchable spring blocks (16), one end of the spring block (16) is connected with the inside of the limiting pad (18).
4. A cold upset forming die for producing a press-in nut according to claim 1, wherein The inside of the main mold shell (14) is fixedly provided with a punch sleeve (21) for guiding the movement of the punch body (15), and one side of the punch sleeve (21) is recessed.
5. A cold upset forming die for producing a press-in nut according to claim 4, wherein The side end of the punch sleeve (21) is provided with a punch pad block (22), the side end of the punch pad block (22) is provided with a protrusion, which is butt jointed with the side end of the punch sleeve (21), and the outside of the punch pad block (22) is provided with a thimble (23) for butt joint fixation.
6. A cold upset forming die for producing a press-in nut according to claim 1, wherein The surface of the nut body (12) is provided with an embossed tooth and a guide groove.