Punch rod for simultaneous stretching of inner and outer holes with small hole features

Abstract

The utility model discloses a punch stick of inner and outer hole synchronous stretching with small hole feature, including punch end and fixed end, the inner hole that is used for the stretching of material middle part position is seted up in punch end middle part, the detachable connection of punch cap has in punch end, the through -hole that punch cap corresponds inner hole position seted up with the concentricity of inner hole, the partial embedding of punch cap is in the inner hole and is in the inner wall of inner hole and is pasted, the guide portion that is used for guiding the material to enter the inner hole when punching is provided in the through -hole, and this kind of punch stick can stretch the material with small hole feature and form, and the convenient operation simple structure.

Description

Technical Field

[0001] This utility model relates to the field of punching technology, specifically a punch with a small hole feature that allows for simultaneous stretching of inner and outer holes. Background Technology

[0002] Some existing parts to be processed have the characteristics of inner and outer holes. When such parts are processed using traditional mold structures, it is often necessary to stretch and form the inner and outer holes separately through two stations. It is not possible to process the inner and outer holes at the same time. In such parts with inner and outer holes, especially a part with a small hole, the existing punches cannot stretch and form the inner and outer holes at the same time, let alone stretch and form the unique small hole. Moreover, the traditional processing method is complicated and cannot meet the requirements. Utility Model Content

[0003] To address the shortcomings of existing technologies, the purpose of this utility model is to provide a punch bar with small hole features that can simultaneously stretch the inner and outer holes of materials with small hole structures, thereby solving the problems mentioned in the background art, such as the inability of traditional punch bars to simultaneously stretch the inner and outer holes of materials with small hole structures, and the complexity and inconvenience of the operation process.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a punch bar with a small hole feature for synchronous stretching of inner and outer holes, comprising a punching end and a fixed end. The punching end has an inner hole in the middle for stretching the material at the middle position. A punching cap is detachably connected to the punching end. The punching cap has a through hole concentric with the inner hole at the position corresponding to the inner hole. The punching cap is partially embedded in the inner hole and fits against the inner wall of the inner hole. A guide part is provided in the through hole for guiding the material into the inner hole during punching.

[0005] As a further improvement of this utility model, the guide part includes an arc-shaped guide wall provided at the position corresponding to the opening of the through hole and an inclined wall provided at the position corresponding to the inner hole. The arc-shaped guide wall and the inclined wall are connected and are both arranged circumferentially along the inner peripheral wall of the inner hole.

[0006] As a further improvement of this utility model, a shock-absorbing pad is provided between the inclined wall and the inner peripheral wall of the inner hole, with one side of the shock-absorbing pad being in contact with the inclined wall and the other side being in contact with the inner peripheral wall of the inner hole.

[0007] As a further improvement of this utility model, the stamping cap is snapped into place with the stamping end.

[0008] As a further improvement of this utility model, the inner wall of the inner hole is provided with a hardening layer, the hardness of which is greater than the hardness of the stamping end body, and the surface of the hardening layer is a rough surface.

[0009] As a further improvement of this utility model, the stamping end and the fixed end are integrally formed, the radial width of the stamping end is smaller than the radial width of the fixed end, and an annular notch for accommodating the stamping cap is formed between the stamping end and the fixed end.

[0010] As a further improvement of this utility model, the surface of the stamping end is provided with an anti-oxidation coating.

[0011] Compared with the prior art, this utility model provides a punch with a small hole feature for synchronous stretching of inner and outer holes, which has the following advantages: the inner hole of the punching end and the concentric through hole of the punching cap cooperate to allow the material to enter the inner hole through the through hole, realizing synchronous stretching of the material inside and outside the hole. This solves the problems of poor coaxiality and low forming accuracy caused by asynchronous stretching of inner and outer holes in traditional punches, and improves the consistency of workpiece dimensions; the guide part inside the through hole can smoothly guide the material into the inner hole, reduce material flow resistance, avoid material wrinkling and cracking during stretching, improve forming quality, and reduce scrap rate; the punching cap is detachable and fits against the inner wall of the inner hole. After wear, only the punching cap needs to be replaced, without replacing the entire punch, reducing maintenance costs; at the same time, punching caps with different specifications of through holes can be replaced to adapt to various hole diameter requirements, improving the versatility of the punch. Attached Figure Description

[0012] Figure 1 This is the front view of the present invention; Figure 2 This is a cross-sectional view of the shock-absorbing pad of this utility model when it is made of elastic rubber material; Figure 3 This is a partial cross-sectional view of the shock-absorbing pad layer of this utility model when it is a metal spring sheet; Figure 4 This is a cross-sectional view of the stamping cap of this utility model.

[0013] Reference numerals: 1. Stamping end; 2. Fixed end; 3. Stamping cap; 4. Annular notch; 11. Inner hole; 12. Hardened layer; 13. Anti-oxidation coating; 31. Through hole; 32. Guide part; 321. Arc-shaped guide wall; 322. Inclined wall; 323. Shock-absorbing pad layer. Detailed Implementation

[0014] As shown in the figure, to achieve the above-mentioned objective, this utility model provides a punch bar with a small hole feature for synchronous stretching of inner and outer holes, including a punching end 1 and a fixed end 2. The punching end 1 has an inner hole 11 in the middle for stretching the material at the middle position. A punching cap 3 is detachably connected to the punching end 1. The punching cap 3 has a through hole 31 concentric with the inner hole 11 at the position corresponding to the inner hole 11. The punching cap 3 is partially embedded in the inner hole 11 and fits against the inner wall of the inner hole 11. A guide part 32 is provided in the through hole 31 for guiding the material into the inner hole 11 during punching.

[0015] In implementation, this solution includes an integrally formed stamping end 1 and a fixed end 2, with the fixed end 2 used for connection and fixation to the stamping equipment. An inner hole 11 is axially formed in the center of the stamping end 1, used for stretching and forming the middle portion of the material. A stamping cap 3 is detachably connected to the side of the stamping end 1 away from the fixed end 2. The stamping cap 3 has a through hole 31 corresponding to the position of the inner hole 11, and the through hole 31 is concentric with the inner hole 11 and has the same diameter. An insert portion is formed on the side of the stamping cap 3 near the stamping end 1. The outer diameter of this insert portion matches the inner diameter of the inner hole 11, and the insert portion is embedded in the inner hole 11 and fits tightly against the inner wall of the inner hole 11. A guide portion 32 is provided inside the through hole 31. When the punch presses the material, the guide portion 32 can smoothly guide the material into the inner hole 11, achieving synchronous stretching of the inner and outer holes. During assembly, first align the embedded part of the stamping cap 3 with the inner hole 11 and insert it, so that the through hole 31 and the inner hole 11 are precisely aligned. Then, fix it with a detachable structure to ensure that the two do not move relative to each other during the stamping process. In this solution, a snap-fit ​​structure is preferred as the detachable structure. In other solutions, threaded connection, plug-in connection and other detachable connection methods can also be used.

[0016] As an improved specific embodiment, the guide part 32 includes an arc-shaped guide wall 321 provided at the opening position of the through hole 31 and an inclined wall 322 provided at the position of the inner hole 11. The arc-shaped guide wall 321 and the inclined wall 322 are connected and are both arranged circumferentially along the inner peripheral wall of the inner hole 11.

[0017] In implementation, the guide section 32 includes an arc-shaped guide wall 321 and an inclined wall 322. The arc-shaped guide wall 321 is located at the opening of the through hole 31 away from the inner hole 11, and is continuously arranged along the circumference of the through hole 31. Its cross-section is an outwardly convex arc shape, which can reduce the resistance when the material enters. The inclined wall 322 is located on the side close to the inner hole 11, and is continuously arranged along the circumference of the inner circumference of the inner hole 11. The inclined wall 322 extends inclinedly from the end of the arc-shaped guide wall 321 towards the axis of the inner hole 11, forming a gradual transition structure. The arc-shaped guide wall 321 and the inclined wall 322 are smoothly connected, with no sharp edges at the connection point to avoid scratching the material. When the material enters the through hole 31 under the action of punching force, it is first initially guided by the arc-shaped guide wall 321, and then further guided into the inner hole 11 by the inclined wall 322, realizing the smooth flow of the material and ensuring the synchronicity of the stretching of the inner and outer holes and the forming quality.

[0018] As an improved specific implementation, a shock-absorbing pad 323 is provided between the inclined wall 322 and the inner peripheral wall of the inner hole 11. One side of the shock-absorbing pad 323 is attached to the inclined wall 322, and the other side is attached to the inner peripheral wall of the inner hole 11.

[0019] In this implementation, a shock-absorbing pad 323 is provided between the inclined wall 322 and the inner peripheral wall of the inner hole 11. In the first embodiment, the shock-absorbing pad 323 is made of elastic rubber material, its shape adapted to the contact surfaces of the inclined wall 322 and the inner peripheral wall, and is bonded and fixed to the inclined wall 322 and the inner peripheral wall respectively using a high-temperature resistant adhesive. In the second embodiment, the shock-absorbing pad 323 is a metal spring sheet, the spring sheet is annular and evenly distributed circumferentially, one side is welded and fixed to the inclined wall 322, and the other side abuts against the inner peripheral wall. During the stamping process, the shock-absorbing pad 323 can absorb part of the impact force, reducing vibration and wear between the inclined wall 322 and the inner hole 11 wall, while buffering the reaction force during material stretching, improving the service life and stamping stability of the punch.

[0020] As an improved specific implementation, the stamping cap 3 is snapped into the stamping end 1.

[0021] In this solution, an annular groove is provided on the outer peripheral wall of the stamping end 1, and an annular block is provided on the inner wall of the stamping cap 3 at the corresponding position. The cross-section of the block is triangular, and the shape of the groove is adapted to the block. During assembly, the stamping cap 3 is aligned with the stamping end 1 and pressed down forcefully, so that the block is elastically deformed and inserted into the groove to achieve fixation.

[0022] As an improved embodiment, the inner wall of the inner hole 11 is provided with a hardening layer 12, the hardness of which is greater than the hardness of the stamping end 1 body, and the surface of the hardening layer 12 is a rough surface.

[0023] In this implementation, a carburizing and quenching process is used to form a hardened layer 12. The stamping end 1 is placed in a carburizing medium and heated to allow carbon atoms to penetrate into the inner wall of the inner hole 11. Subsequently, quenching is performed to form the hardened layer 12, which has a hardness higher than that of the stamping end 1 itself. The surface of the hardened layer 12 is roughened by sandblasting. In another embodiment, those skilled in the art can form the hardened layer 12 by spraying cemented carbide. Plasma spraying technology is used to spray cemented carbide powder onto the inner wall of the inner hole 11 to form a coating and increase hardness. The surface is roughened by electrical discharge machining. The hardened layer 12 improves the wear resistance of the inner hole 11, and the roughened surface enhances the friction with the material, ensuring stability during the stretching process.

[0024] As an improved specific implementation, the stamping end 1 and the fixed end 2 are integrally formed structures, the radial width of the stamping end 1 is smaller than the radial width of the fixed end 2, and an annular notch 4 for accommodating the stamping cap 3 is formed between the stamping end 1 and the fixed end 2.

[0025] In this design, the stamping end 1 and the fixed end 2 are integrally formed using a single forging process. The radial width of the stamping end 1 is smaller than that of the fixed end 2, and an annular notch 4 is formed at their connection. The width of this notch matches the thickness of the stamping cap 3. However, after the stamping cap 3 is connected to the stamping end 1, it will not completely fill the annular notch 4. When the stamping cap 3 is installed on the stamping end 1, a portion of the stamping cap 3 is located within the notch, allowing for a smooth transition between the outer surface of the stamping cap 3 and the outer surface of the fixed end 2. The integrally formed structure enhances the overall strength of the punch and avoids stress concentration that may occur with separate connections. The annular notch 4 not only provides space for the stamping cap 3 but also acts as an axial limiter, preventing the stamping cap 3 from moving towards the fixed end 2 during stamping and ensuring stamping accuracy.

[0026] As an improved embodiment, the surface of the stamping end 1 is provided with an anti-oxidation coating 13.

[0027] In the implementation of this solution, an electroplating process is used to form a chromium-plated coating to achieve oxidation resistance and wear resistance.

[0028] The above are merely preferred embodiments of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are within its protection scope. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within its protection scope.

Claims

1. A punch rod for inner and outer hole synchronous stretching with small hole characteristics, characterized by, It includes a stamping end and a fixed end. The stamping end has an inner hole in the middle for stretching the material at the middle position. A stamping cap is detachably connected to the stamping end. The stamping cap has a through hole concentric with the inner hole at the position corresponding to the inner hole. The stamping cap is partially embedded in the inner hole and fits against the inner wall of the inner hole. A guide part is provided in the through hole for guiding the material into the inner hole during stamping.

2. Punching rod with internal and external hole synchronous stretching with small hole characteristics according to claim 1, characterized in that, The guide portion includes an arc-shaped guide wall positioned at the location of the through hole opening and an inclined wall positioned at the location of the inner hole. The arc-shaped guide wall and the inclined wall are connected and are both arranged circumferentially along the inner circumferential wall of the inner hole.

3. The punch bar with synchronously stretched inner and outer holes featuring a small hole characteristic according to claim 2, characterized in that, A shock-absorbing pad is provided between the inclined wall and the inner peripheral wall of the inner hole. One side of the shock-absorbing pad is attached to the inclined wall, and the other side is attached to the inner peripheral wall of the inner hole.

4. The punch bar with synchronously stretched inner and outer holes featuring a small hole characteristic according to claim 1, characterized in that, The stamping cap is snapped into place with the stamping end.

5. The punch bar with synchronously stretched inner and outer holes featuring a small hole characteristic according to claim 1, characterized in that, The inner wall of the inner hole is provided with a hardening layer, the hardness of which is greater than the hardness of the stamping end body, and the surface of the hardening layer is rough.

6. The punch bar with synchronously stretched inner and outer holes featuring a small hole characteristic according to claim 1, characterized in that, The stamping end and the fixed end are integrally formed. The radial width of the stamping end is smaller than the radial width of the fixed end. An annular notch for accommodating the stamping cap is formed between the stamping end and the fixed end.

7. The punch bar with synchronously stretched inner and outer holes featuring a small hole characteristic according to claim 1, characterized in that, The surface of the stamping end is provided with an anti-oxidation coating.

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