Trifurcate universal joint cold extrusion die

Abstract

The utility model provides a cold extrusion die for a tripod universal joint, and belongs to the technical field of automobile part manufacturing equipment. The problem that the forming quality of an existing mold product is reduced is solved. The three-fork universal joint cold extrusion die comprises two symmetrically-arranged split dies, the split dies are cylindrical, the end face of one end of each split die is a parting surface, a semi-forming groove is formed in the parting surface, an annular exhaust groove is formed in the parting surface around the semi-forming groove, and an inner enclosure wall is formed in the position, between the exhaust groove and the semi-forming groove, of the parting surface; an outer peripheral wall is formed on the outer edge of the parting surface and located on the outer side of the exhaust groove, an inner notch communicated with the semi-forming groove and the exhaust groove is formed in the inner peripheral wall, and an outer notch communicated with the exhaust groove and the outside is formed in the outer peripheral wall. The mold improves the forming quality of products.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of automobile accessory manufacturing equipment, and relates to a three-pronged universal joint cold extrusion die. BACKGROUND

[0002] The universal joint is a universal joint, which is a machine part for realizing variable-angle power transmission and is used at positions where the direction of the transmission axis needs to be changed. It is the "joint" component of the universal transmission device of the automobile driving system. The universal joint includes a non-uniform speed universal joint, a quasi-uniform speed universal joint, and a uniform speed universal joint, etc. The three-ball pin type universal joint is a kind of uniform speed universal joint, which includes a bell-shaped shell and a three-ball pin located in the bell-shaped shell. At present, the three-pronged frame of the three-ball pin is extruded by a three-pronged universal joint cold extrusion die, and then machined to meet the assembly precision requirements.

[0003] Since the three-pronged frame of the three-ball pin is a symmetrical structure, the existing three-pronged universal joint cold extrusion die generally includes two symmetrically arranged split molds, and each split mold has a semi-molding groove on the parting surface. When the two split molds are abutted with the mold, the semi-molding grooves are combined into an enclosed molding cavity for forming the three-pronged frame. In the process of rapid closing of the mold, the air in the molding cavity is extruded by the three-pronged frame blank material to form high-pressure gas, which can easily cause pores or even cracks on the three-pronged frame, resulting in a decrease in the forming quality of the three-pronged frame product. UTILITY MODEL CONTENTS

[0004] The utility model aims at the above-mentioned problems existing in the prior art, and provides a three-pronged universal joint cold extrusion die, which solves the technical problem of how to improve the product forming quality.

[0005] The purpose of the utility model can be realized by the following technical schemes:

[0006] The three-pronged universal joint cold extrusion die includes two symmetrically arranged split molds, the split mold is in a cylindrical shape, and the end face of one end of the split mold is a parting surface, a semi-molding groove is arranged on the parting surface, characterized in that an annular exhaust groove is arranged around the semi-molding groove on the parting surface, an inner enclosing wall is formed between the exhaust groove and the semi-molding groove on the parting surface, an outer enclosing wall is formed at the outer edge of the parting surface outside the exhaust groove, an inner notch is formed on the inner enclosing wall and communicates the semi-molding groove and the exhaust groove, and an outer notch is formed on the outer enclosing wall and communicates the exhaust groove and the outside.

[0007] During the cold extrusion molding process, the semi-forming grooves of the two molds close together to form a forming cavity. The outer walls of the two molds abut against each other, and the inner walls also abut against each other, so that the two venting grooves merge into one venting channel. The air in the forming cavity can be discharged to the outside through the inner notch, the venting groove, and the outer notch. In this way, the gas in the forming cavity is discharged from the mold, thereby reducing the impact of high-pressure gas on the forming of the tripod, that is, reducing the porosity and cracks of the tripod caused by high-pressure gas, and improving the forming quality of the tripod.

[0008] The outer and inner walls have a limiting function when the mold is closed, ensuring that the two venting grooves can be combined into one venting channel when the two molds are closed, so that air can be discharged smoothly. Moreover, the presence of the inner wall has a blocking effect on material flow, which can reduce the formation of flash when the tripod is formed, and also helps to improve the forming quality of the tripod.

[0009] In the aforementioned three-pronged universal joint cold extrusion die, the inner notch and the outer notch are staggered in the circumferential direction at the parting point.

[0010] This arrangement ensures that the outer wall and the inner notch are opposite each other. The outer wall acts as a barrier to the flow of material, preventing excess material flowing out of the inner notch from damaging the mold base on the outside of the mold. In addition, it increases the resistance to material flow, preventing insufficient density in the part of the product corresponding to the inner notch, and also helps to improve the forming quality of the three-pronged support.

[0011] In the aforementioned three-pronged universal joint cold extrusion die, the semi-forming groove includes a central part and three shaft forks arranged around the central part, and the inner notch has three parts and is respectively connected to the outer ends of the three shaft forks.

[0012] During cold extrusion, the blank material is generally placed in the center. When the mold is opened and closed, the blank material diffuses and flows from the center to the shaft fork. The inner notch is connected to the outer end of the shaft fork, which allows as much air as possible to be discharged from the parting cavity, thereby improving the molding quality of the product.

[0013] In the aforementioned three-pronged universal joint cold extrusion die, there are three external notches, which are staggered with the three internal notches in the circumferential direction of the die parting.

[0014] The external notch is also designed with three notches to allow air passing through the three internal notches to escape as quickly as possible, reducing the impact of air on the product molding quality. In addition, this design also ensures that the mold is subjected to uniform force during venting, making the mold work more stably.

[0015] In the aforementioned three-pronged universal joint cold extrusion die, the side wall of the outer notch and the outer wall of the venting groove are rounded. This allows for smooth venting.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] A ring-shaped venting groove is set around the semi-forming groove on the parting surface. An inner notch is set on the inner wall and an outer notch is set on the outer wall. This allows air in the forming cavity to be discharged through the inner notch, venting groove and outer notch, reducing the impact of air on the forming quality of the tripod and thus improving the forming quality of the product. Attached Figure Description

[0018] Figure 1 This is a front view of a parting line in the cold extrusion die of this three-pronged universal joint.

[0019] Figure 2 yes Figure 1 A cross-sectional view along the AA direction.

[0020] Figure 3 This is a cross-sectional view of the cold extrusion die for a three-pronged universal joint when the two molds are being closed.

[0021] In the figure, 1 is the parting line; 1a is the parting surface; 1b is the semi-forming groove; 1b1 is the center part; 1b2 is the shaft fork part; 1c is the venting groove; 1d is the inner wall; 1d1 is the inner notch; 1e is the outer wall; 1e1 is the outer notch. Detailed Implementation

[0022] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0023] like Figure 1 and Figure 2 As shown, the cold extrusion die for a three-pronged universal joint includes two symmetrically arranged parting dies 1. Each parting die 1 is cylindrical, with one end face serving as a parting surface 1a. A semi-forming groove 1b is provided on the parting surface 1a, and an annular venting groove 1c is provided around the semi-forming groove 1b. An inner wall 1d is formed on the parting surface 1a between the venting groove 1c and the semi-forming groove 1b, and an outer wall 1e is formed at the outer edge of the parting surface 1a outside the venting groove 1c. The depth of the venting groove 1c is 0.3mm-1.0mm, typically 0.5mm. An inner notch 1d1 is provided on the inner wall 1d, connecting the semi-forming groove 1b and the venting groove 1c. An outer notch 1e1 is provided on the outer wall 1e, connecting the venting groove 1c and the outside. The inner notch 1d1 and the outer notch 1e1 are staggered circumferentially on the parting die 1. The sidewall of the outer notch 1e1 and the outer wall of the venting groove 1c are rounded. During the cold extrusion molding process, the semi-forming grooves 1b of the two parting molds 1 merge to form a forming cavity for forming the tripod. The outer walls 1e of the two parting molds 1 abut against each other, and the inner walls 1d also abut against each other, so that the two exhaust grooves 1c merge into an exhaust channel. The inner notches 1d1 of the two parting molds 1 merge to form an air inlet, and the outer notches 1e1 of the two parting molds 1 merge to form an air outlet.

[0024] The semi-forming groove 1b includes a central portion 1b1 and three shaft fork portions 1b2 arranged around the central portion 1b1. There are three inner notches 1d1, each connected to the outer end of one of the three shaft fork portions 1b2. The outer ends of the three shaft fork portions 1b2 are inclined outward at an angle of 2°-5°, typically 3°, to facilitate demolding. There are three outer notches 1e1, which are staggered with the three inner notches 1d1 in the circumferential direction of the mold parting 1. The three outer notches 1e1 and the three inner notches 1d1 are evenly arranged in the circumferential direction of the mold parting 1.

[0025] During cold extrusion, the blank material is placed at the center 1b1, such as... Figure 3 As shown, when the two molds 1 are closed, their parting surfaces 1a abut against each other, and the two molds 1 are symmetrically arranged. The blank material diffuses and flows from the center part 1b1 to the shaft fork part 1b2. Air in the parting cavity is discharged through the inner notch 1d1, the venting groove 1c, and the outer notch 1e1, reducing the impact of high-pressure gas on the forming of the tripod, that is, reducing the porosity and cracks caused by high-pressure gas in the tripod, and improving the forming quality of the tripod. In addition, the outer end face of the shaft fork part 1b2 has a limiting function, which not only reduces the waste of raw materials, but also makes the blank at the end of the tripod shaft fuller, and can reduce the allowance for direct finishing, reducing one roughing step, thus achieving the purpose of cost reduction and efficiency improvement.

[0026] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A cold extrusion die for a triple cardan joint, comprising two symmetrical split dies (1), the split dies (1) being cylindrical and the end face of one end of the split dies (1) being a parting surface (1a), a semi-formed groove (1b) being provided on the parting surface (1a), characterized in that, An annular exhaust groove (1c) is arranged on the parting surface (1a) around the semi-forming groove (1b), an inner surrounding wall (1d) is formed on the parting surface (1a) between the exhaust groove (1c) and the semi-forming groove (1b), an outer surrounding wall (1e) is formed on the outer edge of the parting surface (1a) outside the exhaust groove (1c), an inner notch (1d1) is formed on the inner surrounding wall (1d) and communicates with the semi-forming groove (1b) and the exhaust groove (1c), and an outer notch (1e1) is formed on the outer surrounding wall (1e) and communicates with the exhaust groove (1c) and the outside.

2. The cold extrusion die for a triple cardan joint according to claim 1, characterized in that, The inner notch (1d1) and the outer notch (1e1) are arranged in a staggered manner in the circumferential direction of the mold (1).

3. The cold extrusion die for a triple cardan joint according to claim 1, characterized in that, The semi-forming groove (1b) comprises a central part (1b1) and three shaft fork parts (1b2) arranged around the central part (1b1), and the inner notch (1d1) is three in number and is connected to the outer end of each of the three shaft fork parts (1b2).

4. The cold extrusion die for a triple cardan joint according to claim 3, characterized in that, The outer notch (1e1) is three in number and is arranged in a staggered manner with the three inner notches (1d1) in the circumferential direction of the mold (1).

5. A cold extrusion die for a triple cardan joint according to any one of claims 1 to 4, characterised in that, The side wall surface of the outer notch (1e1) and the outer side wall surface of the exhaust groove (1c) are connected through a round corner.

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