Tripod and forming device

Abstract

A tripod comprises a tripod frame and three pin shafts circumferentially arranged on the outer circumferential face of the tripod frame, a ball head is arranged at the end of each pin shaft, and an extrusion groove is formed in the center of the outer end face of each ball head. The diameter of the extrusion groove is gradually reduced from the groove opening to the groove bottom; the outer edge of the end face of the end, close to the pin shaft, of the ball head is provided with an annular connecting cambered surface, and the diameter of the connecting cambered surface is gradually decreased in the direction of the pin shaft. The outer wall of the pin shaft is in transition connection with the connecting cambered surface through a corner cambered surface; and the diameter of the corner cambered surface is gradually increased towards the direction of the ball head. According to the tripod, the situation that the density of the corner part where the pin shaft and the ball head intersect is insufficient can be effectively avoided, and the strength of the corner part where the ball head and the pin shaft intersect is effectively guaranteed.

Description

Technical Field

[0001] The invention relates to the field of constant velocity universal joints, in particular to a tripod pin. Background Art

[0002] The tripod is a constant velocity universal joint used in automobile drive shaft assemblies. It is mainly composed of a tripod, a pin shaft, a needle bearing and other components. The three pin shafts are evenly distributed on the outer circumference of the tripod, a ball head is provided at the end of the pin shaft, and the needle bearing is sleeved outside the ball head.

[0003] The tripod is formed by cold pressing in the mold cavity. The blank is first placed in the mold cavity, and then stamping is used to squeeze the blank continuously and fill the cavity to form a product with the same shape as the cavity. The cavity is composed of a tripod cavity for forming a tripod, a pin cavity for forming a pin shaft, and a ball head cavity for forming a ball head. When the blank fills the tripod cavity, it will be squeezed into the pin shaft cavity, and then into the ball head cavity. The ball head diameter of the tripod is larger than the pin diameter, so the diameter of the pin shaft cavity is smaller than the diameter of the ball head cavity. When the blank is squeezed into the ball head cavity, the blank will not fill the corner position where the ball head and the pin shaft intersect immediately, but will flow toward the depth of the ball head cavity first. When it contacts the bottom surface of the ball head cavity, it will spread outward and flow back to the corner position where the ball head and the pin shaft intersect under the obstruction of the inner surface of the ball head cavity. This filling method causes the corner position where the ball head and the pin shaft intersect to be the last filling position, and the blank at the corner position where the ball head and the pin shaft intersect cannot be fully extruded, resulting in insufficient density at this position, affecting the strength. Summary of the invention

[0004] The present invention aims to solve the existing technical problem by providing a tripod pin and a forming device, which can effectively avoid the situation where the density of the corner where the pin shaft and the ball head intersect is insufficient, and effectively ensure the strength of the corner where the ball head and the pin shaft intersect.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] The invention discloses a tripod pin, comprising a tripod rack, three pin shafts circumferentially arranged on the outer circumference of the tripod rack, a ball head being arranged at the end of the pin shaft, an extrusion groove being arranged at the center of the outer end surface of the ball head; the diameter of the extrusion groove gradually decreases from the groove opening to the groove bottom; an annular connecting arc surface is arranged at the outer edge of an end surface of the ball head adjacent to the pin shaft, and the diameter of the connecting arc surface gradually decreases toward the direction of the pin shaft; the outer wall of the pin shaft and the connecting arc surface are transitionally connected by a corner arc surface; the diameter of the corner arc surface gradually increases toward the direction of the ball head.

[0007] The inner wall of the extrusion groove is provided with a plurality of limiting planes which are evenly distributed in a circumference.

[0008] Adjacent limiting planes are transitionally connected via a guide cambered surface.

[0009] A plurality of guide arc surfaces are located at one end of the bottom of the extrusion groove and are connected through an annular arc-shaped concave surface.

[0010] The outer peripheral surface of the three-pin bracket and the outer wall of the pin shaft are transitionally connected through an annular guide arc surface, and the diameter of the guide arc surface gradually decreases toward the pin shaft.

[0011] A forming device comprises a pressure module and a stamping module; the pressure module and the stamping module are fitted together, and the side walls opposite to each other are provided with mutually symmetrical three-pin rack grooves, pin shaft grooves, ball head grooves and telescopic grooves; the three-pin rack grooves on the pressure module and the stamping module are combined to form an annular three-pin rack cavity; the pin shaft grooves on the pressure module and the stamping module are combined to form a pin shaft cavity; the ball head grooves on the pressure module and the stamping module are combined to form a ball head cavity; the pressure module and the telescopic grooves on the stamping film are combined to form a ball head cavity The contraction grooves enclose a telescopic cavity; there are three pin shaft cavities, which are evenly arranged on the outer circumferential surface of the ball head cavity; the ball head cavity is arranged at the outer end of the pin shaft cavity, and the diameter of the ball head cavity is larger than the diameter of the pin shaft cavity; the telescopic cavity is arranged at the center of the outer end surface of the ball head cavity, and the diameter of the ball head cavity is larger than the diameter of the telescopic cavity; a telescopic shaft matching with it is arranged in the telescopic cavity, and the outer end of the telescopic shaft passes outward to the outside of the telescopic cavity; an extrusion head located in the ball head cavity is arranged at the center of the inner end surface of the telescopic shaft, and the diameter of the extrusion head gradually decreases toward the pin shaft cavity.

[0012] The inner wall of the three-pin bracket cavity is transitionally connected to the inner wall of the pin shaft cavity via a first annular arc surface; the inner edge of one end of the ball head cavity adjacent to the pin shaft cavity is provided with a third annular arc surface; the inner wall of the pin shaft cavity and the third arc surface are transitionally connected via a second annular arc surface.

[0013] The inner edge of one end of the ball head cavity away from the pin shaft cavity is provided with a fourth arc surface in an annular shape.

[0014] A fifth arc surface in the shape of an annular ring is provided on the outer edge of one end face of the extrusion head adjacent to the pin shaft cavity; a sixth arc surface in the shape of an annular ring is provided on the outer wall of one end of the extrusion head located at the center of the inner end face of the telescopic shaft; a plurality of seventh arc surfaces located between the fifth arc surface and the sixth arc surface are provided on the outer wall of the extrusion head; and the seventh arc surface cuts the outer wall of the extrusion head into a plurality of support planes evenly distributed around the circumference.

[0015] The outer edge of the inner end surface of the telescopic shaft is provided with a chamfer.

[0016] The beneficial effects of the present invention are:

[0017] Compared with the prior art, the three-ball pin and forming device using the structure of the present invention cannot directly flow axially toward the deep part of the ball head cavity because the extrusion head is in the ball head cavity. Instead, the flow trajectory is directly changed under the obstruction of the inner end face of the extrusion head, and flows directly toward the corner position where the pin shaft and the ball head intersect, and then flows along the trajectories of the second arc surface and the third arc surface in sequence to the space between the outer wall of the extrusion head and the inner circumferential surface of the ball head cavity. This flow trajectory of the metal billet can ensure that there is enough billet to fill the corner position where the pin shaft and the ball head intersect, and effectively avoid the situation where the billet axially enters the deep part of the ball head cavity and then flows back to the corner position where the pin shaft and the ball head intersect, resulting in the billet at the corner position where the pin shaft and the ball head intersect cannot be fully extruded, thereby causing insufficient density, and effectively ensuring the strength of the corner position where the pin shaft and the ball head intersect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a tripod pin of the present invention;

[0019] Figure 2 It is a front view of a tripod pin of the present invention;

[0020] Figure 3 It is a structural schematic diagram of the molding device of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0022] See also Figures 1 to 3 The present invention provides a tripod pin, comprising a tripod bracket 1, three pin shafts 2 circumferentially arranged on the outer circumference of the tripod bracket 1, a ball head 3 being arranged at the end of the pin shaft 2, an extrusion groove 4 being arranged at the center of the outer end surface of the ball head 3; the diameter of the extrusion groove 4 gradually decreases from the groove opening to the groove bottom; an annular connecting arc surface 5 is arranged at the outer edge of one end surface of the ball head 3 adjacent to the pin shaft 2, and the diameter of the connecting arc surface 5 gradually decreases toward the pin shaft 2; the outer wall of the pin shaft 2 and the connecting arc surface 5 are transitionally connected by a corner arc surface 6; the diameter of the corner arc surface 6 gradually increases toward the ball head 3.

[0023] The inner wall of the extrusion groove 4 is provided with a plurality of limiting planes 7 evenly distributed in a circle. The existence of the supporting plane 25 enables the limiting plane 7 to be formed. The existence of the limiting plane 7 can form uniform supporting points in the extrusion groove 4, ensuring that the blank can be stably formed in the outer circle of the extrusion groove 4.

[0024] Adjacent limiting planes 7 are transitionally connected by a guide arc surface 8. The existence of the seventh arc surface 24 enables the guide arc surface 8 to be formed. The existence of the guide arc surface 8 can play a guiding role when the blank is formed in the outer ring of the extrusion groove 4, ensuring the smoothness of the blank flow and ensuring uniform density and stable strength of the ball head 3.

[0025] A plurality of guide arc surfaces 8 are located at one end of the bottom of the extrusion groove 4 and are connected by an annular arc-shaped concave surface 9. The existence of the fifth arc surface 22 can shape the arc-shaped concave surface, which plays a guiding role when the blank flows to the outer circle space of the extrusion groove 4 through the corner position where the pin shaft 2 and the ball head 3 intersect, further ensuring the smoothness of the blank flow.

[0026] The outer circumferential surface of the tripod 1 and the outer wall of the pin shaft 2 are transitionally connected by an annular guide arc surface 10. The existence of the first arc surface 18 can shape the guide arc surface. The diameter of the guide arc surface 10 gradually decreases toward the direction of the pin shaft 2. The diameter of the guide arc surface 10 gradually decreases toward the direction of the pin shaft 2. Since the diameter of the pin shaft cavity is much smaller than the diameter of the tripod cavity, when the blank is squeezed from the tripod cavity into the pin shaft cavity, it will encounter great resistance. At this time, the existence of the guide arc surface 10 can effectively reduce the resistance and improve the smoothness of the blank flow, thereby effectively improving the blank forming efficiency.

[0027] The presence of the extrusion head 17 can form the extrusion groove 4. Since the diameter of the extrusion groove 4 gradually decreases from the groove mouth to the groove bottom, when the blank enters the ball head cavity, the deeper it goes into the ball head cavity, the smaller the space is, so that the resistance during extrusion is greater. This resistance will form a relative force, causing a part of the blank in the ball head cavity to flow back to the corner position where the pin shaft 2 and the ball head 3 intersect, effectively improving the density and strength of the corner position where the pin shaft 2 and the ball head 3 intersect. At the same time, this shape is conducive to demolding after the extrusion groove 4 is formed. In actual design, the shape of the extrusion groove 4 can be designed into various shapes according to actual needs, such as hemispherical, triangular, etc., and is not limited to the shape disclosed in the present invention.

[0028] The existence of the second arc surface 20 can shape the corner arc surface 6, and the existence of the third arc surface 19 can shape the connecting arc surface 5. Since the diameter of the corner arc surface 6 gradually increases toward the ball head 3, and the diameter of the connecting arc surface 5 gradually decreases toward the pin shaft 2, when the blank is squeezed from the pin shaft cavity into the ball head cavity, it can play a guiding role, effectively reducing the resistance of the blank flow, making it easier to fill the blank at the corner position where the pin shaft 2 and the ball head 3 intersect, further ensuring the density and strength of the corner part where the pin shaft 2 and the ball head 3 intersect.

[0029] A forming device, comprising a pressure module 11 and a stamping module; the pressure module 11 and the stamping module are fitted together, and the side walls opposite to each other are provided with mutually symmetrical three-pin rack grooves 12, pin shaft grooves 13, ball head grooves 14 and telescopic grooves 15; the pressure module 11 and the three-pin rack grooves 12 on the stamping module are combined to form an annular three-pin rack cavity; the pressure module 11 and the pin shaft grooves 13 on the stamping module are combined to form a pin shaft cavity; the pressure module 11 and the ball head grooves 14 on the stamping module are combined to form a ball head cavity; the pressure module 11 A telescopic cavity is formed by enclosing the telescopic groove 15 on the stamping film; there are three pin shaft cavities, which are evenly arranged on the outer peripheral surface of the ball head cavity; the ball head cavity is arranged at the outer end of the pin shaft cavity, and the diameter of the ball head cavity is larger than the diameter of the pin shaft cavity; the telescopic cavity is arranged at the center of the outer end surface of the ball head cavity, and the diameter of the ball head cavity is larger than the diameter of the telescopic cavity; a telescopic shaft 16 matching with it is arranged in the telescopic cavity, and the outer end of the telescopic shaft 16 passes outward to the outside of the telescopic cavity; an extrusion head 17 located in the ball head cavity is arranged at the center of the inner end surface of the telescopic shaft 16, and the diameter of the extrusion head 17 gradually decreases toward the pin shaft cavity.

[0030] The inner wall of the three-pin bracket cavity and the inner wall of the pin shaft cavity are transitionally connected via a first annular arc surface 18; the inner edge of one end of the ball head cavity adjacent to the pin shaft cavity is provided with a third annular arc surface 19; the inner wall of the pin shaft cavity and the third arc surface 19 are transitionally connected via a second annular arc surface 20.

[0031] A fourth arc surface 21 in the shape of an annular ring is disposed on the inner edge of one end of the ball head cavity away from the pin shaft cavity.

[0032] A fifth arc surface 22 in the shape of an annular shape is provided on the outer edge of one end surface of the extrusion head 17 adjacent to the pin shaft cavity; a sixth arc surface 23 in the shape of an annular shape is provided on the outer wall of one end of the extrusion head 17 located at the center of the inner end surface of the telescopic shaft 16; a plurality of seventh arc surfaces 24 located between the fifth arc surface 22 and the sixth arc surface 23 are provided on the outer wall of the extrusion head 17; the seventh arc surface 24 cuts the outer wall of the extrusion head 17 into a plurality of supporting planes 25 evenly distributed around the circumference.

[0033] The outer edge of the inner end surface of the telescopic shaft 16 is provided with a chamfer 26 .

[0034] The method of use of the present invention is as follows:

[0035] When the blank needs to be cold-pressed into a tripod pin, the blank is first placed in the tripod slot 12 of the pressure-bearing module 11, and then the stamping module is moved close to the pressure-bearing module 11 and fitted. Under the action of pressure, the blank in the tripod slot 12 will be squeezed. As the blank fills the tripod cavity formed by the pressure-bearing module 11 and the tripod slot 12 on the stamping module, the blank will be squeezed into the pin shaft cavity along the trajectory of the first arc surface 18 under the action of pressure, and then squeezed into the ball head cavity. Since the extrusion head 17 is in the ball head cavity, the blank cannot flow directly axially toward the depth of the ball head cavity, but directly changes the flow trajectory under the obstruction of the inner end face of the extrusion head 17, and flows directly toward the corner position where the pin shaft 2 and the ball head 3 intersect. , and then flows along the trajectories of the second arc surface 20 and the third arc surface 19 to the space between the outer wall of the extrusion head 17 and the inner circumference of the ball head cavity. This flow trajectory of the metal billet can ensure that there is enough billet to fill the corner position where the pin shaft 2 and the ball head 3 intersect, and effectively avoid the situation where the billet axially enters the deep part of the ball head cavity and then flows back to the corner position where the pin shaft 2 and the ball head 3 intersect, resulting in the billet at the corner position where the pin shaft 2 and the ball head 3 cannot be fully extruded, resulting in insufficient density, and effectively ensuring the strength of the corner position where the pin shaft 2 and the ball head 3 intersect. The closer the inner end face of the extrusion head 17 is to the pin shaft cavity, the earlier the billet flows to the corner position where the pin shaft 2 and the ball head 3 intersect. Therefore, the length of the extrusion head 17 can be set according to actual needs.

[0036] After the tripod is formed, the extrusion head 17 is embedded in the extrusion groove 4. At this time, the supporting plane 25 fits with the limiting plane 7, the seventh arc surface 24 fits with the guide arc surface 8, the fifth arc surface 22 fits with the arc-shaped concave surface 9, the connecting arc surface 5 fits with the third arc surface 19, the corner arc surface 6 fits with the second arc surface 20, and the guide arc surface 10 fits with the first arc surface 18. The first arc surface 18, the second arc surface 20, the third arc surface 19 and the fourth arc surface 21 can all play a role in reducing resistance when the blank is stamped and flows, effectively ensuring the smoothness of the blank flow, thereby ensuring the forming efficiency, and the existence of the fifth arc surface 22 and the seventh arc surface 24 can ensure the smoothness of the extrusion head 17 when it escapes from the extrusion groove 4.

[0037] The extrusion head 17 can not only be used to generate the extrusion groove 4 on the ball head 3, but also serve as a support. When the blank is formed into a tripod, the extrusion head 17 is evenly distributed on the outer circle of the tripod, forming a number of circumferentially evenly distributed support points on the outer circle of the tripod, thereby effectively ensuring the stability of the tripod during forming. At the same time, in order to enable the extrusion groove 4 to form other shapes, the extrusion head 17 can be set to various shapes according to actual needs.

[0038] The outer end of the telescopic shaft 16 is connected to the hydraulic cylinder, and the movement of the telescopic shaft 16 in the telescopic chamber can be controlled by the hydraulic cylinder. Only by starting the hydraulic cylinder, the piston rod of the hydraulic cylinder will drive the telescopic shaft 16 to move, and the outer edge of the inner end surface of the telescopic shaft 16 is provided with a chamfer. The existence of the chamfer 26 can effectively ensure the smoothness of the movement of the telescopic shaft 16.

Claims

1. A tripod pin, comprising a tripod pin frame, three pin shafts arranged circumferentially on the outer circumference of the tripod pin frame, and a ball head is arranged at the end of the pin shaft, characterized in that: An extrusion groove is provided at the center of the outer end surface of the ball head; the diameter of the extrusion groove gradually decreases from the groove mouth to the groove bottom; an annular connecting arc surface is provided at the outer edge of the end surface of the ball head adjacent to the pin shaft, and the diameter of the connecting arc surface gradually decreases toward the pin shaft; the outer wall of the pin shaft and the connecting arc surface are transitionally connected by a corner arc surface; the diameter of the corner arc surface gradually increases toward the ball head.

2. A tripod according to claim 1, characterized in that: The inner wall of the extrusion groove is provided with a plurality of limiting planes which are evenly distributed in a circumference.

3. A tripod according to claim 2, characterized in that: Adjacent limiting planes are transitionally connected via a guide cambered surface.

4. A tripod according to claim 3, characterized in that: A plurality of guide arc surfaces are located at one end of the bottom of the extrusion groove and are connected through an annular arc-shaped concave surface.

5. A tripod according to claim 1, characterized in that: The outer peripheral surface of the three-pin bracket and the outer wall of the pin shaft are transitionally connected through an annular guide arc surface, and the diameter of the guide arc surface gradually decreases toward the pin shaft.

6. A molding device for producing the tripod according to claim 1, characterized in that: It comprises a pressure module and a stamping module; the pressure module and the stamping module are fitted together, and the side walls on the opposite sides of the two are provided with mutually symmetrical three-pin rack grooves, pin shaft grooves, ball head grooves and telescopic grooves; the three-pin rack grooves on the pressure module and the stamping module are enclosed to form an annular three-pin rack cavity; the pin shaft grooves on the pressure module and the stamping module are enclosed to form a pin shaft cavity; the ball head grooves on the pressure module and the stamping module are enclosed to form a ball head cavity; the telescopic grooves on the pressure module and the stamping film are enclosed The pin shaft cavities are provided with three and are evenly arranged on the outer circumference of the ball head cavity; the ball head cavity is arranged at the outer end of the pin shaft cavity, and the diameter of the ball head cavity is larger than the diameter of the pin shaft cavity; the telescopic cavity is arranged at the center of the outer end surface of the ball head cavity, and the diameter of the ball head cavity is larger than the diameter of the telescopic cavity; a telescopic shaft matching with the telescopic cavity is arranged in the telescopic cavity, and the outer end of the telescopic shaft passes outward to the outside of the telescopic cavity; an extrusion head located in the ball head cavity is arranged at the center of the inner end surface of the telescopic shaft, and the diameter of the extrusion head gradually decreases toward the pin shaft cavity.

7. A molding device according to claim 6, characterized in that: The inner wall of the three-pin bracket cavity is transitionally connected to the inner wall of the pin shaft cavity via a first annular arc surface; the inner edge of one end of the ball head cavity adjacent to the pin shaft cavity is provided with a third annular arc surface; the inner wall of the pin shaft cavity and the third arc surface are transitionally connected via a second annular arc surface.

8. A molding device according to claim 6, characterized in that: The inner edge of one end of the ball head cavity away from the pin shaft cavity is provided with a fourth arc surface in an annular shape.

9. A molding device according to claim 6, characterized in that: A fifth arc surface in the shape of an annular ring is provided on the outer edge of one end face of the extrusion head adjacent to the pin shaft cavity; a sixth arc surface in the shape of an annular ring is provided on the outer wall of one end of the extrusion head located at the center of the inner end face of the telescopic shaft; a plurality of seventh arc surfaces located between the fifth arc surface and the sixth arc surface are provided on the outer wall of the extrusion head; and the seventh arc surface cuts the outer wall of the extrusion head into a plurality of support planes evenly distributed around the circumference.

10. A molding device according to claim 6, characterized in that: The outer edge of the inner end surface of the telescopic shaft is provided with a chamfer.

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