Structure of inclined forming die for riveting nut

Abstract

A kind of oblique thread forming die structure of riveting nut, including a forging die seat, a first forging die, a second forging die and a limiting piece;Forging die seat is made with a die cavity, the die cavity is provided with a threaded portion;The first forging die is made with a nut die hole and a forging die hole, the nut die hole penetrates the forging die hole, and a shoulder is formed between the two;The front end of the second forging die is provided with a slope, the inner surface is provided with an oblique thread portion and a through guide hole, and the oblique thread portion is composed of a plurality of inclined convex teeth;The second forging die is placed in the forging die hole together with the first forging die into the die cavity, the limiting piece is limited in the die cavity, and the second forging die and the forging die hole form low friction contact. The flange of the nut blank will be directly compression molded into an oblique thread convex tooth in the oblique thread portion of the second forging die, and when the mold is withdrawn, the second forging die is easily rotated with the inclination of the oblique thread convex tooth, and finally the flange is smoothly removed from the second forging die.

Description

Technical Field

[0001] This invention relates to a riveting nut forming mold structure, and more particularly to a riveting nut forming mold structure that can directly form oblique teeth on a nut forming machine during the continuous forming process of riveting nuts. Background Technology

[0002] A rivet nut is a connecting component that is press-fitted into an anchor hole in a thin metal sheet to provide bolt-on fastening. For example... Figure 1 As shown, a known riveting nut 10 with oblique teeth is presented. The riveting nut 10 mainly includes a nut body 11 and a flange 12. A threaded hole 13 with internal threads passes through the nut body 11 and the flange 12. The outer surface of the flange 12 is provided with oblique teeth 14 arranged at equal intervals. The oblique teeth 14 are protruding from the outer surface of the flange 12 at an angle, which is different from the known common design of axially parallel teeth. The oblique teeth 14 can improve the friction between the riveting nut and the plate. In addition to preventing the riveting nut from rotating, it also has the function of preventing the riveting nut from axially dislodging.

[0003] The known manufacturing process for riveting nuts mainly involves using nut forming machines commonly used in the industry. These machines utilize a series of molds to shape the blank into a nut prototype with a flange after several forging and shaping processes. However, since the forging action of the nut forming machine is mostly axial, it is only suitable for processing riveting nuts with straight grooves. If oblique grooves are forged and shaped using traditional molds in these known nut forming machines, it will be difficult to directly demold due to the interference between the oblique grooves and the mold. Forcing demolding can easily damage the workpiece or the mold. Therefore, the industry currently mainly achieves oblique grooves through a knurling process.

[0004] As explained above, the known oblique-knotted riveting nut cannot be directly processed using existing nut forming machines. It requires a second processing step through a knurling process, which significantly reduces overall production efficiency and greatly impacts production volume. Therefore, it is necessary for relevant manufacturers to explore better processing methods or improve mold equipment to enhance the forming efficiency of oblique-knotted nuts. Summary of the Invention

[0005] The main objective of this invention is to address the shortcomings of the prior art by providing a mortise forming mold structure for riveting nuts. This mold structure can directly form the mortise protrusion of the riveting nut on a nut forming machine, effectively improving production efficiency and significantly increasing the production volume of mortise protrusion riveting nuts.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a rivet nut forming die structure, characterized in that it comprises: a forging die base having a die cavity with a threaded portion; a first forging die having a nut cavity and a forging die cavity, the nut cavity penetrating the forging die cavity, and a sloping shoulder forming between the nut cavity and the forging die cavity; and a second forging die, the main body of the second forging die being a hollow cylindrical shape, the front end of the second forging die having a beveled surface, and the inner surface having a sloping portion and a through guide hole, the sloping portion being composed of several sloping protrusions; the second forging die being placed in the forging die cavity and together with the first forging die being placed in the die cavity, a limiting member being screwed onto the threaded portion of the forging die base, cooperating to restrict the first forging die and the second forging die within the die cavity, and causing the second forging die to form a low-friction contact with the forging die cavity.

[0007] The slope of the inclined surface corresponds to the slope of the shoulder.

[0008] The outer wall of the second forging die does not contact the inner wall of the forging die cavity.

[0009] The overall height of the second forging die is greater than 99.5% of the depth of the forging die cavity but less than the depth of the forging die cavity.

[0010] The inclination angle of the oblique convex teeth is between 35 and 45°.

[0011] In this invention, the flange of the nut blank is directly press-molded into oblique teeth on the oblique portion of the second forging die. During demolding, because the second forging die and the die cavity have low frictional contact, the second forging die can easily rotate according to the oblique angle of the oblique teeth on the oblique portion, ultimately allowing the flange to smoothly exit from the second forging die. Accordingly, this invention overcomes the deficiency that the oblique teeth of riveted nuts cannot be directly processed on known nut processing machines, and further significantly increases the production volume of oblique riveted nuts by omitting the two processing steps of the knurling process. Attached Figure Description

[0012] Figure 1 This is a three-dimensional schematic diagram of a known diagonal thread riveting nut.

[0013] Figure 2 This is an exploded view of the structure of a preferred embodiment of the present invention.

[0014] Figure 3 This is a cross-sectional schematic diagram of a preferred embodiment of the present invention.

[0015] Figure 4 This is a schematic diagram of extruding a flanged nut blank to create a diagonal pattern.

[0016] Figure 5 This is a schematic diagram of the action of the second forging die when the nut with the diagonal pattern is removed from the die cavity.

[0017] Symbol explanation:

[0018] 10. Riveting nuts

[0019] 11. Nut body

[0020] 12. Flange

[0021] 13. Screw hole

[0022] 14. Diagonal convex teeth

[0023] 20. Forging die holder

[0024] 21. Mold cavity

[0025] 22. Threaded section

[0026] 23. Limiting components

[0027] 30. First forging die

[0028] 31. Forging die cavity

[0029] 32. Nut mold cavity

[0030] 33. Sloping shoulder area

[0031] 40. Second forging die

[0032] 41. Against the slope

[0033] 42. Twill section

[0034] 421. Oblique convex teeth

[0035] 43. Guide hole

[0036] 50. Nut blank

[0037] 51. Flange

[0038] 52. Diagonal convex teeth

[0039] 60a, front punch

[0040] 60b, rear punch. Detailed Implementation

[0041] To fully describe the structural features, technical content, effects and other characteristics of the present invention, the following detailed description is provided in conjunction with the accompanying drawings and preferred embodiments.

[0042] First, please refer to Figure 2The diagram shows a preferred embodiment of the oblique pattern forming mold structure for the riveting nut of the present invention, which mainly consists of a forging die base 20, a first forging die 30, and a second forging die 40. The forging die base 20 has a mold cavity 21 to accommodate the first forging die 30 and the second forging die 40. The first forging die 30 has a forging die cavity 31 to accommodate the second forging die 40. The shape of the second forging die 40 is similar to that of the forging die cavity 31, but a dimensional tolerance is preset. A threaded portion 22 is provided in the mold cavity 21 near the open end, and a limiting member 23 is screwed into the threaded portion 22 to restrict the first forging die 30 and the second forging die 40 within the mold cavity 21.

[0043] Please refer to this again. Figure 3 As shown, is Figure 2 The diagram shows a cross-sectional view of the oblique pattern forming mold structure for the riveting nut of the present invention. The first forging die 30 has a forging die cavity 31 and a nut die cavity 32. The nut die cavity 32 passes through the forging die cavity 31, forming an oblique shoulder 33 between them. Please refer to... Figure 4 As shown, the main body of the second forging die 40 is a hollow cylindrical structure. The front end of the second forging die 40 has a beveled surface 41, corresponding to the slope of the shoulder portion 33. The inner surface of the second forging die 40 has a beveled section 42 and a through-hole 43. The beveled section 42 is the part where the flange of the nut blank is formed into beveled teeth. The beveled section 42 is composed of several beveled teeth 421, and the inclination angle of the beveled teeth 421 is between 35-45°. The outer diameter of the die 40 does not correspond to the inner wall of the forging die cavity 31. In this embodiment, the diameter is described as tapering at 5° from the inclined surface 41 to the rear end. That is, the outer shape of the second forging die 40 does not correspond to the inner shape of the forging die cavity 31 and they do not contact each other. In addition, the overall height of the second forging die 40 is less than the depth of the forging die cavity 31 and greater than 99.5% of the depth of the forging die cavity 31, so that the second forging die 40 and the forging die cavity 31 form a low-friction combination.

[0044] Please refer to this again. Figure 4 The figure shows a schematic diagram of the forging operation of a preferred embodiment of the present invention. The forging process of the nut processing machine is mainly divided into two stages. The first stage is the die stage, in which the front punch and the rear punch simultaneously extrude the nut blank. The second stage is the demolding stage, in which the rear punch pushes the nut blank out of the forming die cavity. The figure shows a schematic diagram of the nut blank 50 being extruded and formed using the die of the present invention in the die stage. The nut blank 50 has been placed in the nut cavity 32 by the feeding mechanism before the punch is actuated. Under the extrusion of the front punch 60a and the rear punch 60b, the flange 51 of the nut blank 50 is press-formed into oblique teeth 52 at the second forging die 40.

[0045] Finally, please refer to... Figure 5The diagram illustrates how the preferred embodiment of the present invention smoothly completes the mold removal action. The figure shows the nut blank 50 being pushed out of the nut die cavity 32 by the rear punch 60b. During this process, while the nut blank 50 is not rotating, the second forging die 40, due to the low-friction contact between it and the forging die cavity 31, can easily rotate along with the angle of the oblique teeth of the oblique groove portion 42. This ultimately allows the flange 51 of the nut blank 50 to smoothly disengage from the second forging die 40, thereby achieving the primary goal of directly forming the oblique groove of the riveted nut on the nut processing machine while avoiding damage to the oblique groove 52 of the blank and the oblique groove portion of the die.

[0046] After the above embodiments are described, it can be easily understood that the present invention has at least the following advantages: 1. The oblique pattern forming mold structure of the riveting nut of the present invention overcomes the deficiency that known nut processing machines cannot successfully complete the oblique pattern protrusion processing. 2. The application of the present invention omits the two processing steps of the known oblique pattern riveting nut knurling process, effectively shortening the processing procedure and time, and significantly increasing the production volume of oblique pattern riveting nuts.

[0047] In summary, the oblique pattern forming mold structure for the riveting nut of the present invention has indeed achieved its intended purpose and meets the needs of the industry, and a patent application is hereby filed in accordance with the law. However, although the present invention has been disclosed with reference to the foregoing preferred embodiments, the dimensions, shapes, or quantities shown in the drawings are not intended to limit the present invention. Those skilled in the art may make modifications or alterations without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A cross-forming die structure for swaging a cap nut, characterized by, It comprises: a forging die seat, which is formed with a die cavity, the die cavity is provided with a threaded portion; a first forging die, which is formed with a nut die cavity and a forging die cavity, the nut die cavity penetrates the forging die cavity, and a shoulder portion is formed between the nut die cavity and the forging die cavity; and a second forging die, which is in the form of a hollow cylinder, the outer surface of the front end of the second forging die is provided with an abutting inclined surface, the inner surface of the second forging die is formed with an inclined thread portion and a penetrating guide hole, the inclined thread portion is composed of a plurality of inclined convex teeth; the first forging die is placed in the die cavity, the second forging die is placed in the forging die cavity, the abutting inclined surface abuts against the shoulder portion, a limiting member is screwed on the threaded portion of the forging die seat, the first forging die and the second forging die are limited in the die cavity, and the outer wall of the second forging die does not contact the inner wall of the forging die cavity, so that the second forging die and the forging die cavity form a low-friction contact.

2. The inclined forming die structure for clinching a cap nut according to claim 1, wherein The inclination of the abutting inclined surface corresponds to the inclination of the shoulder portion.

3. The inclined forming die structure for clinching a cap nut according to claim 1, wherein The overall height of the second forging die is greater than 99.5% of the depth of the forging die cavity and less than the depth of the forging die cavity.

4. The inclined forming die structure for clinching a nut cap according to claim 1, wherein The inclination angle of the inclined convex teeth is between 35-45°.

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