New structure of transmission shaft closed extrusion fork type preform

Abstract

The utility model discloses a new structure of transmission shaft closed extrusion fork class preformed piece, including the pole part and the fork lug part, and the outermost side of the left side and the right side of fork lug part is the circular structure, the connecting part of pole part and fork lug part between positive and negative side includes the first conical surface, and the connecting part of pole part and fork lug part between left side and right side includes the second conical surface and the third conical surface, the utility model discloses through to three key parts optimization improvement, reduces the rate of waste and the repair rate of forging, has improved the forming quality and overall performance of final forging significantly, meets the harsh demand of automobile transmission shaft to size precision and light weight, conforms to the development trend of modern automobile key part manufacturing technology of high efficiency, energy saving, convenient processing, the preformed piece structure of improvement can realize 0.15kg of blanking lightening, 0.05kg of burr lightening, has reduced the cost, has improved the yield of product, has reduced the labor intensity of worker to some extent simultaneously.

Description

Technical Field

[0001] This utility model belongs to the field of automotive drive shaft manufacturing technology, specifically relating to a new structure of a closed-type extrusion fork-type pre-forged drive shaft. Background Technology

[0002] With the rapid rise of the commercial vehicle industry and the continuous optimization of vehicle performance, the production technology standards for automotive driveshafts are also increasing. The requirements for dimensional accuracy and lightweighting of automotive driveshafts are becoming increasingly stringent. Near-net-shape forming technology is needed to reduce subsequent processing steps. High efficiency, energy saving, and ease of processing are the development trends of key automotive component manufacturing technologies today. Researching new structures for closed-loop extrusion fork-type pre-forged parts is of great significance to the development of enterprises.

[0003] The existing closed-type extrusion fork pre-forging structure is as follows: Figure 1 and Figure 2 As shown, the fork-type pre-forging with this structure includes a rod portion 1 and a fork lug portion 2, and has the following problems: 1) Figure 1 The outer part A1 of the middle fork ear 2 is only a slope during the pre-forging process. It needs to be formed into a round part in the subsequent final forging process. However, the slope of the outer part of the fork ear 2 is unstable when it is formed into a round part during the final forging process. As a result, the outer parts of the two fork ears 2 of the final forging are missing material and it is difficult to form a complete round part.

[0004] 2) Figure 2 The transition surface of the connecting part B1 between the rod part 1 and the fork lug part 2 is not smooth and is a concave arc transition, resulting in poor metal flow. During the final forging process, the metal flow in this part B1 is uneven, and the surface of the forging has wavy stripes. It may even cause defects such as folding and cracking in this area. This not only affects the overall quality of the final forging but also reduces the product qualification rate and increases production costs.

[0005] 3) Figure 1 The connecting part C1 between the middle rod part 1 and the fork lug part 2 on the left and right sides has a 65mm R-shaped circular arc surface at the connection point with the fork lug part and a 20mm R-shaped rounded corner transition at the connection point with the rod part 1. This causes the pre-forged part to be placed too high when it is placed into the final forging cavity, which may cause metal backflow and folding. Utility Model Content

[0006] The purpose of this invention is to provide a new structure for a closed-type extrusion fork pre-forged part with a transmission shaft that facilitates final forging and improves the quality of final forged products.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a new structure for a closed-type extrusion fork-like pre-forged part of a transmission shaft, including a rod and a fork lug, wherein the outermost sides of the left and right sides of the fork lug are circular; the connecting part between the rod and the fork lug on the front and back sides includes a first conical surface, which is connected to the fork lug by a first convex arc surface, and the first conical surface is connected to the rod by a first concave arc surface; the connecting part between the rod and the fork lug on the left and right sides includes a second conical surface and a third conical surface, which is connected to the fork lug by a second convex arc surface, the second conical surface is connected to the third conical surface by a second concave arc surface, and the third conical surface is connected to the rod by a third concave arc surface.

[0008] The outer surface of the circular structure is a convex spherical shape.

[0009] The angle between the generatrix of the first conical surface and the center line of the rod is 33°, and the radii of the first convex arc surface and the first concave arc surface are 15mm.

[0010] The angle between the generatrix of the second conical surface and the center line of the rod is 47°, the angle between the generatrix of the third conical surface and the center line of the rod is 21°, the radius of the second convex arc surface is 46mm, the radius of the second concave arc surface is 25mm, and the radius of the third concave arc surface is 15mm.

[0011] By adopting the above technical solution, compared with the prior art, this utility model has the following technical effects: (1) The outermost surfaces of the left and right sides of the fork lugs have a contour that is closer to the shape of the final forging when they are pre-forged. Specifically, the outermost surfaces of the left and right sides of the fork lugs are circular structures during pre-forging. This design not only improves the stability during final forging and makes the spherical shape easier to demold, but also ensures the integrity and material fullness of the outer sides of the two fork lugs during final forging.

[0012] (2) By increasing the smoothness of the transition part (first convex arc surface and first concave arc surface) and adding the first conical surface at the connection part between the rod and the fork lug, the fluidity of the metal is effectively improved, making the forging process smoother, thereby improving the quality and yield of the forging.

[0013] (3) The connection between the left and right sides of the rod and the fork lug has been moderately adjusted. From the fork lug to the rod, the connection is the second convex arc surface, the second conical surface, the second concave arc surface, the third conical surface and the third concave arc surface. The generatrix angle of the second conical surface is greater than that of the third conical surface. The radii of the second convex arc surface, the second concave arc surface and the third concave arc surface also gradually decrease. This makes the connection between the fork lug and the rod smoother and more natural. This structure also makes the pre-forged part fill the cavity more smoothly when it is put into the final forging cavity, avoiding the folding problem caused by the frame being too high, thereby improving the forming quality and overall performance of the final forging part.

[0014] In summary, this invention, through optimization and improvement of three key components, yields a new structure for a closed-loop extrusion fork-type pre-forging part with higher quality and superior performance. This reduces the scrap rate and rework rate of forgings, significantly improves the forming quality and overall performance of the final forging, meets the stringent requirements of automotive driveshafts for dimensional accuracy and lightweighting, and aligns with the development trend of modern automotive key component manufacturing technologies that emphasize high efficiency, energy saving, and ease of processing. The improved pre-forging part structure can reduce blanking weight by 0.15 kg and burr weight by 0.05 kg, lowering costs, increasing product yield, and simultaneously reducing the labor intensity of workers to some extent. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the existing structure of a closed-type extrusion fork pre-forged part; Figure 2 yes Figure 1 Side view; Figure 3 This is a schematic diagram of the structure of this utility model; Figure 4 yes Figure 3 Side view; Figure 5 yes Figure 3 Enlarged view of section A2; Figure 6 yes Figure 3 Enlarged view of section B2; Figure 7 yes Figure 3 Enlarged view of part C2. Detailed Implementation

[0016] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples.

[0017] like Figures 3-7 As shown, the novel structure of the closed-type extrusion fork pre-forged part of the transmission shaft of this utility model includes a rod part 1 and a fork lug part 2. The outermost sides of the left and right sides of the fork lug part 2 are circular structures 3. The connection between the front and back sides of the rod part 1 and the fork lug part 2 includes a first conical surface 4. The first conical surface 4 and the fork lug part 2 are transitioned by a first convex arc surface 5, and the first conical surface 4 and the rod part 1 are transitioned by a first concave arc surface 6. The connection between the left and right sides of the rod part 1 and the fork lug part 2 includes a second conical surface 7 and a third conical surface 8. The second conical surface 7 and the fork lug part 2 are transitioned by a second convex arc surface 9, the second conical surface 7 and the third conical surface 8 are transitioned by a second concave arc surface 10, and the third conical surface 8 and the rod part 1 are transitioned by a third concave arc surface 11.

[0018] The outer surface of circular structure 3 is a convex spherical shape.

[0019] The angle between the generatrix of the first conical surface 4 and the center line 12 of the rod 1 is 33°, and the radii of the first convex arc surface 5 and the first concave arc surface 6 are 15mm.

[0020] The angle between the generatrix of the second conical surface 7 and the center line 12 of the rod 1 is 47°, the angle between the generatrix of the third conical surface 8 and the center line 12 of the rod 1 is 21°, the radius of the second convex arc surface 9 is 46mm, the radius of the second concave arc surface 10 is 25mm, and the radius of the third concave arc surface 11 is 15mm.

[0021] The improvements and optimizations of this utility model have the following technical effects: (1) When the outermost sides of the left and right sides of the fork lugs 2 are pre-forged, they have a contour that is closer to the shape of the final forging. Specifically, during pre-forging, the outermost sides of the left and right sides of the fork lugs 2 are circular structures 3. This design not only improves the stability during final forging and makes the spherical shape easier to demold, but also ensures the integrity and material fullness of the outer sides of the two fork lugs 2 during final forging.

[0022] (2) By increasing the smoothness of the transition part (first convex arc surface 5 and first concave arc surface 6) and adding the first conical surface 4 at the connection part between the rod part 1 and the fork ear part 2 on the front and back sides, the fluidity of the metal is effectively improved, making the forging process smoother, thereby improving the quality and yield of the forging.

[0023] (3) The connection between the left and right sides of the rod 1 and the fork ear 2 has been moderately adjusted. From the fork ear 2 to the rod 1, the connection consists of the second convex arc surface 9, the second conical surface 7, the second concave arc surface 10, the third conical surface 8, and the third concave arc surface 11. The generatrix angle of the second conical surface 7 is greater than that of the third conical surface 8. The radii of the second convex arc surface 9, the second concave arc surface 10, and the third concave arc surface 11 also gradually decrease. This makes the connection between the fork ear 2 and the rod 1 smoother and more natural. This structure also allows the pre-forged part to fill the cavity more smoothly when it is placed into the final forging cavity, avoiding the folding problem caused by the frame being too high, thereby improving the forming quality and overall performance of the final forging part.

[0024] The above embodiments illustrate the basic principles and features of this utility model. However, the above descriptions are merely preferred embodiments and are not limited to these embodiments. Those skilled in the art, inspired by this patent, can make many modifications and improvements without departing from the spirit and scope of the claims, all of which fall within the protection scope of this utility model. Therefore, the patent and its scope of protection should be determined by the appended claims.

Claims

1. A novel structure for a closed-loop extrusion fork-type pre-forged part with a drive shaft, comprising a rod portion and a fork lug portion, characterized in that: The outermost sides of the left and right sides of the fork lug are circular structures; the connection between the rod and the fork lug includes a first conical surface, which is connected to the fork lug by a first convex arc surface, and the first conical surface is connected to the rod by a first concave arc surface; the connection between the rod and the left and right sides of the fork lug includes a second conical surface and a third conical surface, which is connected to the fork lug by a second convex arc surface, the second conical surface is connected to the third conical surface by a second concave arc surface, and the third conical surface is connected to the rod by a third concave arc surface.

2. The novel structure of the closed-type extrusion fork pre-forged part of the transmission shaft according to claim 1, characterized in that: The outer surface of the circular structure is a convex spherical shape.

3. The novel structure of the closed-type extrusion fork-type pre-forged part of the transmission shaft according to claim 1, characterized in that: The angle between the generatrix of the first conical surface and the center line of the rod is 33°, and the radii of the first convex arc surface and the first concave arc surface are 15mm.

4. The novel structure of the closed-type extrusion fork-type pre-forged part of the transmission shaft according to claim 1, characterized in that: The angle between the generatrix of the second conical surface and the center line of the rod is 47°, the angle between the generatrix of the third conical surface and the center line of the rod is 21°, the radius of the second convex arc surface is 46mm, the radius of the second concave arc surface is 25mm, and the radius of the third concave arc surface is 15mm.

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