Tripod pin
By designing extrusion grooves and arc-shaped structures on the three-ball pins, the flow trajectory of the billet is changed, solving the problem of insufficient density at the corner of the ball head and pin shaft, and improving strength and molding efficiency.
Patent Information
- Application Number
- CN202520302318.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-02-24
AI Technical Summary
The existing three-ball pins have insufficient density at the corner where the ball head intersects the pin shaft, resulting in insufficient strength.
The design incorporates structures such as extrusion grooves, corner arc surfaces, connecting arc surfaces, and guiding arc surfaces to alter the billet flow trajectory, ensuring that the billet fully fills the corner positions and guaranteeing density and strength.
This effectively avoids insufficient density, improves the strength of the corner where the ball head and pin intersect, and enhances molding efficiency and density uniformity.
Smart Images
Figure CN223938505U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of constant velocity universal joint, in particular to a three ball pin. BACKGROUND
[0002] Three ball pin is a kind of constant velocity universal joint for automobile drive shaft assembly, it is mainly by three pin frame, pin shaft and needle roller bearing etc. Component is composed, three pin shaft is evenly distributed on the outer circumferential surface of three pin frame, pin shaft end is provided with ball head, and needle roller bearing is then covered in ball head outside.
[0003] Three ball pin is cold pressure forming using the cavity of mould, first, blank is placed into the cavity of mould, then, blank is continuously extruded and filled in cavity using stamping, and the product with the same shape as cavity is formed, and the cavity is composed of three pin frame cavity for forming three pin frame, pin shaft cavity for forming pin shaft and ball head cavity for forming ball head, when blank fills three pin frame cavity, blank is extruded into pin shaft cavity, and then into ball head cavity, and the diameter of ball head of three ball pin is greater than the diameter of pin shaft, so the diameter of pin shaft cavity is less than the diameter of ball head cavity, when blank is extruded into ball head cavity, blank does not fill the corner position where ball head and pin shaft intersect first time, but flows to the depth of ball head cavity, when contacting the bottom surface of ball head cavity, diffuses outward again, and flows back to fill the corner position where ball head and pin shaft intersect under the block of inner circumferential surface of ball head cavity, this filling mode causes the corner position where ball head and pin shaft intersect to be the last filling position, and the blank at the corner position where ball head and pin shaft intersect cannot be extruded sufficiently, so that the density of this position is insufficient, and the strength is affected. SUMMARY
[0004] The utility model provides a kind of three ball pin, it can effectively avoid the insufficient density of the corner position where pin shaft and ball head intersect, effectively guarantee the strength of the corner position where ball head and pin shaft intersect.
[0005] The utility model solves the above-mentioned technical problems using the technical scheme that:
[0006] The utility model discloses a kind of three ball pins, including three pin frame, three pin shafts, pin shaft end is provided with ball head, the outer end surface center of ball head is equipped with a extrusion groove;The diameter of extrusion groove gradually decreases from slot to slot bottom;The outer edge of the end surface of ball head adjacent pin shaft is equipped with a annular connecting camber, and the diameter of connecting camber gradually decreases towards pin shaft direction;The outer wall of pin shaft and connecting camber are connected by a corner camber transition;The diameter of corner camber gradually increases towards ball head direction.
[0007] The inner wall of extrusion groove is equipped with several limit planes that are evenly distributed in circumference.
[0008] Adjacent limiting planes are connected by a guide arc surface.
[0009] Several guide arc surfaces are connected at one end of the bottom of the extrusion groove by a ring-shaped concave surface.
[0010] The outer circumferential surface of the three pins is connected to the outer wall of the pin shaft by a ring-shaped guide arc surface, the diameter of which gradually decreases towards the pin shaft.
[0011] The beneficial effects of this utility model are:
[0012] Compared with the prior art, the three-ball pin structure of this utility model, when cold-pressed, allows the extrusion groove to block the flow of the blank by its bottom. This prevents the blank from flowing directly axially from the pin cavity of the mold into the depth of the ball head cavity. Instead, the blank is blocked by the bottom of the extrusion groove, causing it to change its flow trajectory and flow directly towards the corner where the pin and ball head intersect. Then, it flows sequentially along the trajectory of the corner arc surface and the connecting arc surface to the outer space of the extrusion groove. This flow trajectory of the metal blank ensures that enough blank fills the corner where the pin and ball head intersect, effectively preventing the blank from flowing axially into the depth of the ball head cavity of the mold and then back to the corner where the pin and ball head intersect, which would result in insufficient compression and thus insufficient density. This effectively ensures the strength of the corner where the pin and ball head intersect. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the structure of the three-ball pin of this utility model;
[0014] Figure 2 This is the front view of the three-ball pin of this utility model. Detailed Implementation
[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:
[0016] Please see Figure 1 , Figure 2 This utility model provides a three-ball pin, including a three-pin holder 1 and three pins 2 arranged circumferentially on the outer circumference of the three-pin holder 1. The pins 2 are provided with ball heads 3 at their ends. The outer end face of the ball head 3 is provided with a pressing groove 4 at its center. The diameter of the pressing groove 4 gradually decreases from the groove opening to the groove bottom. The outer edge of the end face of the ball head 3 adjacent to the pin 2 is provided with an annular connecting arc surface 5. The diameter of the connecting arc surface 5 gradually decreases towards the pin 2. The outer wall of the pin 2 and the connecting arc surface 5 are connected by a corner arc surface 6. The diameter of the corner arc surface 6 gradually increases towards the ball head 3.
[0017] The inner wall of the extrusion groove 4 is provided with several circumferentially evenly distributed limiting planes 7.
[0018] Adjacent limiting planes 7 are connected by a guide arc surface 8.
[0019] Several guide arc surfaces 8 are connected at one end of the bottom of the extrusion groove 4 by an annular arc-shaped concave surface 9.
[0020] The outer peripheral surface of the three pin bracket 1 and the outer wall of the pin shaft 2 are connected by a ring-shaped guide arc surface 10, the diameter of which gradually decreases towards the pin shaft 2.
[0021] The method of using this utility model is as follows:
[0022] When the three-pin holder 1 is formed, if the billet is squeezed from the pin cavity of the mold into the ball head cavity, because the center of the outer end face of the ball head 3 is provided with an extrusion groove 4, the extrusion groove 4 can use its own bottom to block the flow of the billet, so that the billet cannot flow directly axially into the depth of the ball head cavity. Instead, under the obstruction of the bottom of the extrusion groove 4, the flow trajectory is directly changed, and it flows directly to the corner position where the pin 2 and the ball head 3 intersect. Then, it flows sequentially along the trajectory of the corner arc surface 6 and the connecting arc surface 5 to the outer space of the extrusion groove 4. This flow trajectory of the metal billet can ensure that... Sufficient blank material is filled at the corner where pin 2 and ball head 3 intersect, effectively preventing the blank material from axially entering the deep part of the ball head cavity of the mold and then flowing back to the corner where pin 2 and ball head 3 intersect, which would result in insufficient compression of the blank material at the corner where pin 2 and ball head 3 intersect and thus insufficient density. This effectively ensures the strength of the corner where pin 2 and ball head 3 intersect. The closer the bottom of the extrusion groove 4 is to the inner end face of the ball head, the earlier the blank material flows to the corner where pin 2 and ball head 3 intersect. Therefore, the depth of the extrusion groove 4 can be set according to actual needs.
[0023] Since the diameter of the extrusion groove 4 gradually decreases from the opening to the bottom, the space becomes smaller as the billet enters the ball head cavity of the mold, resulting in greater resistance during extrusion. This resistance creates a relative force, causing some of the billet in the ball head cavity to flow in the opposite direction to the corner where the pin 2 and the ball head 3 intersect. This effectively increases the density and strength of the corner where the pin 2 and the ball head 3 intersect. At the same time, this shape facilitates 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 this utility model.
[0024] Since the diameter of the corner arc surface 6 gradually increases towards the ball head 3, and the diameter of the connecting arc surface 5 gradually decreases towards the pin 2, it can guide the blank when it is added from the pin cavity of the mold into the ball head cavity, effectively reducing the resistance of the blank flow, making it easier for the blank to fill the corner position where the pin 2 and the ball head 3 intersect, and further ensuring the density and strength of the corner part where the pin 2 and the ball head 3 intersect.
[0025] The inner wall of the extrusion groove 4 is provided with several circumferentially evenly distributed limiting planes 7. The presence of the limiting planes 7 can form uniform support points in the extrusion groove 4, ensuring that the billet can be stably formed on the outer ring of the extrusion groove 4.
[0026] Adjacent limiting planes 7 are connected by a guide arc surface 8. The presence of the guide arc surface 8 can guide the billet when it is formed on the outer ring of the extrusion groove 4, ensuring the smooth flow of the billet and ensuring uniform density and stable strength at all parts of the ball head.
[0027] Several guide arc surfaces 8 are connected at one end of the bottom of the extrusion groove 4 by an annular arc concave surface 9. When the billet flows to the outer space of the extrusion groove 4 through the corner where the pin 2 and the ball head 3 intersect, it plays a guiding role and further ensures the smoothness of the billet flow.
[0028] The outer peripheral surface of the three-pin holder 1 and the outer wall of the pin 2 are connected by a ring-shaped guide arc surface 10. The diameter of the guide arc surface 10 gradually decreases towards the pin 2. Since the diameter of the pin cavity is much smaller than the diameter of the three-pin holder cavity, the billet will encounter great resistance when it is squeezed from the three-pin holder cavity into the pin cavity. At this time, the presence of the guide arc surface 10 can effectively reduce the resistance and improve the smoothness of the billet flow, thereby effectively improving the billet forming efficiency.
Claims
1. A three-ball pin, comprising three pin frames and three pins arranged circumferentially on the outer circumference of the three pin frames, wherein each pin has a ball end, characterized in that: A compression groove is provided at the center of the outer end face of the ball head; the diameter of the compression groove gradually decreases from the groove opening to the groove bottom; a ring-shaped connecting arc surface is provided on the outer edge of the end face of the ball head near the pin shaft, and the diameter of the connecting arc surface gradually decreases towards the pin shaft; the outer wall of the pin shaft and the connecting arc surface are connected by a corner arc surface; the diameter of the corner arc surface gradually increases towards the ball head.
2. A three-ball pin according to claim 1, characterized in that: The inner wall of the extrusion groove is provided with several circumferentially evenly distributed limiting planes.
3. A three-ball pin according to claim 2, characterized in that: Adjacent limiting planes are connected by a guide arc surface.
4. A three-ball pin according to claim 3, characterized in that: Several guide arc surfaces are connected at one end of the bottom of the extrusion groove by a ring-shaped concave surface.
5. A three-ball pin according to claim 1, characterized in that: The outer circumferential surface of the three pins is connected to the outer wall of the pin shaft by a ring-shaped guide arc surface, the diameter of which gradually decreases towards the pin shaft.