Cold heading method for brake system oval t-shaped bushing of electric vehicle

Abstract

The application provides a cold upsetting manufacturing method of an elliptical T-shaped bushing of a brake system of an electric vehicle. The elliptical T-shaped bushing of the brake system of the electric vehicle is directly manufactured through cold upsetting four-mold manufacturing. Through the method, raw material utilization and quality can be improved, and production efficiency can be improved. In addition, the size is uniform, and the product has high strength.

Description

Technical Field

[0001] This invention relates to the field of multi-station cold heading technology, and specifically to a cold heading manufacturing method for an elliptical T-shaped bushing for a braking system of an electric vehicle. Background Technology

[0002] The elliptical T-shaped bushing for electric vehicle braking systems is an important component of electric vehicle braking systems.

[0003] The elliptical T-shaped bushing for an electric vehicle braking system has the following structural shape: it includes an elliptical cylindrical sleeve, the cross-section of which is composed of two symmetrical first semicircular hole walls and a first straight edge hole wall connecting the two ends of the two first semicircular hole walls, forming an inner hole and an outer wall of the elliptical cylinder. At one end of the elliptical cylindrical sleeve, there is an elliptical protrusion extending to the side, the elliptical protrusion being composed of two symmetrical second semicircles and a second straight edge connecting the two ends of the two second semicircles. The length of the elliptical sleeve is 1.4-1.65 times the outer diameter of the first semicircular hole wall, the length of the first straight edge hole wall of the elliptical cylindrical sleeve is 1.1-1.35 times the length of the elliptical sleeve hole wall, and there is a right-angle transition between the elliptical protrusion and the outer wall of the elliptical cylindrical sleeve.

[0004] In the past, braking systems for electric vehicles were manufactured using machine tools, resulting in low production efficiency and inconsistent quality. Summary of the Invention

[0005] The purpose of this invention is to provide a cold heading manufacturing method for elliptical T-shaped bushings for electric vehicle braking systems, which can improve product quality and efficiency. To this end, this invention adopts the following technical solution: A cold heading manufacturing method for an elliptical T-shaped bushing for an electric vehicle braking system, characterized in that the elliptical T-shaped bushing for the electric vehicle braking system has the following structural shape: it includes an elliptical cylindrical sleeve, the cross-section of which is composed of two symmetrical first semi-circular hole walls and a first straight edge hole wall connecting the two ends of the two first semi-circular hole walls, forming an inner through hole and an outer wall of the elliptical cylinder; one end of the elliptical cylindrical sleeve has an elliptical protrusion extending to the side, the elliptical protrusion being composed of two symmetrical second semi-circles and a second straight edge connecting the two ends of the two second semi-circles; the length of the elliptical cylindrical sleeve is 1.4-1.65 times the outer wall diameter of the first semi-circular hole wall; the length of the first straight edge hole wall of the elliptical cylindrical sleeve is 1.1-1.35 times the hole wall of the elliptical cylindrical sleeve; and the elliptical protrusion transitions at a right angle to the outer wall of the elliptical cylindrical sleeve. The manufacturing method includes the following steps: (1) The coiled material is fed into the cold heading forming machine and automatically cut into individual elliptical T-shaped bushing blanks for electric vehicle braking systems. The diameter of the coiled material is shorter than twice the outer radius of the first semi-circular hole wall and the sum of the length of the first straight side hole wall, and shorter than twice the inner radius of the first semi-circular hole wall and the sum of the length of the first straight side hole wall. The length of the blank is shorter than the length of the elliptical T-shaped bushing for electric vehicle braking systems. (2) The raw material is transferred to the No. 1 mold opening of the cold heading forming machine. After cold heading in the No. 1 mold, the front end of the No. 1 molded product is flattened and the rear end is rounded. (3) The No. 1 molded product is transferred to the No. 2 mold opening and cold-forged in the No. 2 mold, so that the front end of the No. 2 molded product is flattened and the rear end is forged into a rounded corner, and the No. 2 molded product is forged into a first elliptical cylinder whose cross-sectional outer contour is consistent with the outer contour of the elliptical cylinder sleeve. (4) The No. 2 molded product is transferred to the No. 3 mold opening and cold-forged in the No. 3 mold to pre-forge the elliptical head of the first elliptical cylinder. The outer contour of the elliptical head is consistent with the elliptical protrusion, and its thickness is thinner than the thickness of the elliptical protrusion. The elliptical head is then transitioned to the remaining surface of the first elliptical cylinder through a bevel to form the No. 3 molded product. The portion of the elliptical head that protrudes laterally from the surface of the remaining first elliptical cylinder, including the bevel portion, is used to form the elliptical protrusion. (5) The No. 3 molded product is transferred to the No. 4 mold opening and cold-forged in the No. 4 mold to make the front end of the No. 4 molded product have a positioning hole. The amount of metal transferred by the upsetting positioning hole is used to increase the thickness of the elliptical head. (6) The No. 4 molded product is transferred to the No. 5 mold opening. After cold heading in the No. 5 mold, the front end of the No. 4 molded product is headed to form a pre-headed hole for the inner through hole of the elliptical cylinder, and the rear end is headed to form a positioning hole, thus forming the No. 5 molded product. The outline of the pre-headed hole for the inner through hole of the elliptical cylinder is consistent with the outline of the inner through hole of the elliptical cylinder. The No. 5 molded product is extended until the remaining part excluding the length occupied by the elliptical head and the inclined surface is consistent with the length of the elliptical cylinder sleeve. The pre-headed hole for the inner through hole of the elliptical cylinder is separated from the positioning hole of the No. 5 molded product by the iron core to be drilled. (7) The No. 5 molded product is transferred to the No. 6 mold opening and cold-forged in the No. 6 mold to forge the front end of the No. 5 molded product into the elliptical protrusion. The elliptical protrusion transitions at a right angle with the outer wall of the elliptical cylinder sleeve to form the No. 6 molded product. (8) The No. 6 molded product is transferred to the No. 7 mold opening, and cold heading is performed in the No. 7 mold. The No. 6 molded product is then passed through an iron core to produce the elliptical T-shaped bushing for the electric vehicle braking system.

[0006] This invention enables the manufacture of elliptical T-shaped bushings for electric vehicle braking systems using a cold extrusion process. It uses coiled stock instead of straight bars or cut stock. First, a pre-treatment process is employed, involving spheroidizing annealing, phosphate and film surface treatment, and precision drawing and sizing, making the coiled stock more suitable for cold heading. The stock then flows into a cold heading machine, where it is sheared into individual elliptical T-shaped bushing blanks for electric vehicle braking systems using a multi-station method. Subsequently, it is transferred to a multi-station cold heading machine, employing composite extrusion based on engineering mechanics principles. Both ends are simultaneously stressed within the die, completing leveling, elliptical rod diameter upsetting, elliptical head upsetting, elliptical hole punching, head upsetting, and through-hole forming processes in a single operation. This allows the elliptical T-shaped bushing blanks for electric vehicle braking systems to be directly formed. This invention uses 7-station cold extrusion forming, eliminating three processes—machining, drilling, and reaming—compared to the original process. It also provides dimensional stability, significantly reducing material consumption and achieving a material utilization rate of 95%, saving 59.0% of material and substantially reducing costs. Furthermore, the material structure obtained through cold extrusion is more compact, and its tensile, yield, elongation, and impact mechanical properties are superior to those of machined materials, ensuring product quality. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the process flow before the fourth mold in the manufacturing method of the present invention.

[0008] Figure 2 , Figure 3 , Figure 4 These are top views of the second molded product, the third molded product, and the fourth molded product manufactured by the method of the present invention.

[0009] Figure 5 This is a schematic diagram of the process flow for the fifth to seventh molds of the manufacturing method of the present invention.

[0010] Figure 6 , Figure 7 , Figure 8 These are top views of the fifth molded product, the sixth molded product, and the seventh molded product manufactured by the method of the present invention. Detailed Implementation

[0011] Referring to the accompanying drawings, the elliptical T-shaped bushing 100 for an electric vehicle braking system manufactured according to the present invention has the following structural shape: it includes an elliptical cylindrical sleeve 101, the cross-section of which is composed of two symmetrical first semi-circular hole walls 102 and a first straight edge hole wall 103 connecting the two ends of the two first semi-circular hole walls 102, forming an elliptical cylindrical inner hole 108 and an elliptical cylindrical outer wall. At one end of the elliptical cylindrical sleeve 101, there is an elliptical protruding edge 104 protruding laterally. The elliptical protruding edge 104 is composed of two symmetrical second semi-circles 105 and a second straight edge 106 connecting the two ends of the two second semi-circles. The length of the elliptical cylindrical sleeve 101 is 1.4-1.65 times the diameter of the outer wall of the first semi-circular hole wall 102, the length of the first straight edge hole wall 103 of the elliptical cylindrical sleeve 101 is 1.1-1.35 times the length of the elliptical cylindrical sleeve hole wall, and there is a right-angle transition 107 between the elliptical protruding edge 104 and the outer wall of the elliptical cylindrical sleeve.

[0012] The manufacturing method includes the following steps: (1) The coiled material is fed into the cold heading forming machine and automatically cut into individual elliptical T-shaped bushing blanks 10 for electric vehicle braking systems. The coiled material is first heat-treated to spheroidize, then subjected to phosphate surface treatment and fine drawing and sizing treatment. The diameter of the coiled material is shorter than twice the outer wall radius of the first semi-circular hole wall 102 and the sum of the length of the first straight side hole wall 103, and shorter than twice the inner wall radius of the first semi-circular hole wall 102 and the sum of the length of the first straight side hole wall 103 (that is, the length of the cross-sectional profile of the elliptical inner through hole). The length of the blank 10 is shorter than the length of the elliptical T-shaped bushing 100 for electric vehicle braking systems.

[0013] (2) The raw material is transferred to the No. 1 mold opening of the cold heading forming machine. After cold heading in the No. 1 mold, the front end face 11 of the No. 1 molded product 1 is flattened and the rear end is headed out with rounded corners 12.

[0014] (3) Transfer the No. 1 molded product 1 to the No. 2 mold opening. After cold forging in the No. 2 mold, the front end face 21 of the No. 2 molded product 2 is flattened and the rear end is forged into a rounded corner 22. The No. 2 molded product 2 is forged into a first elliptical cylinder 20 whose cross-sectional outer contour is consistent with the outer contour of the elliptical cylinder sleeve 101. Except for the elliptical protrusion 104 to be formed, the cross-sectional outer contour of the remaining part of the first elliptical cylinder 20 will only undergo slight changes in subsequent processes due to the molding.

[0015] (4) The No. 2 molded product 2 is transferred to the No. 3 mold opening. After cold forging in the No. 3 mold, the front end of the first elliptical cylinder 20 is pre-forged into an elliptical head, and the remaining part is the second elliptical cylinder 30. The outer contour of the elliptical head 31 is consistent with the elliptical protrusion 104, and its thickness is thinner than the thickness of the elliptical protrusion 104. It then transitions to the surface of the remaining second elliptical cylinder 30 through the inclined surface 32 to form the No. 3 molded product 3, which protrudes laterally from the surface of the second elliptical cylinder 30. The elliptical head 31, including the inclined surface 32, is used to form the elliptical protrusion, reducing the metal transfer distance and ensuring that the elliptical inner through hole 108 does not deform when forging the elliptical protrusion 104.

[0016] (5) The No. 3 molded product 3 is transferred to the No. 4 mold opening and cold-forged in the No. 4 mold to make the front end of the No. 4 molded product 4 have a positioning hole 41. The amount of metal transferred by the upsetting positioning hole is used to increase the thickness of the elliptical head. The elliptical head with increased thickness is labeled 42.

[0017] (6) The No. 4 molded product 4 is transferred to the No. 5 mold opening. After cold heading in the No. 5 mold, the front end of the No. 4 molded product 4 is headed to form a pre-heading hole 51 for the inner through hole of the elliptical cylinder, and the rear end is headed to form a positioning hole 52, thus forming the No. 5 molded product 5. The outline of the pre-heading hole 51 for the inner through hole of the elliptical cylinder is consistent with the outline of the inner through hole of the elliptical cylinder. The amount of metal transferred by the hole is used to extend the No. 5 molded product to the length of the part 53 excluding the elliptical head 42 and the inclined surface 32, so that the length of this part 53 is consistent with the length of the elliptical cylinder sleeve 101. The outer outline of the cross section of this part 53 is consistent with the outer outline of the elliptical cylinder sleeve 101. That is, the outer wall surface of the elliptical cylinder sleeve 101 has been formed at this time. The pre-heading hole 51 for the inner through hole of the elliptical cylinder is separated from the positioning hole 52 of the No. 5 molded product 5 by the iron core 54 to be drilled.

[0018] (7) The No. 5 molded product 5 is transferred to the No. 6 mold opening and cold-forged in the No. 6 mold to forge the front end of the No. 5 molded product 5 into the elliptical protrusion 104. The metal amount of the elliptical protrusion 104 comes from the elliptical head 42 and the inclined surface 32 after the thickness is increased. The elliptical protrusion 104 and the outer wall of the elliptical cylinder sleeve are right-angled transition 107 to form the No. 6 molded product 6. With the reinforcement of the iron core 54 and the control of the metal amount transfer, it is possible to ensure that the pre-forging hole 51 (elliptical inner through hole 108) does not deform when forging the elliptical protrusion 104. At the same time, the aforementioned part 53 also remains consistent with the outer contour of the elliptical cylinder sleeve 101.

[0019] (8) The No. 6 molded product 6 is transferred to the No. 7 mold opening and cold-forged in the No. 7 mold to pass through the iron core 5 to make the elliptical T-shaped bushing for the electric vehicle braking system.

[0020] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the protection scope of the present invention.

Claims

1. A cold heading manufacturing method for an elliptical T-shaped bushing for a braking system of an electric vehicle, characterized in that, The elliptical T-shaped bushing for the braking system of electric vehicles has the following structural shape: it includes an elliptical cylindrical sleeve, the cross-section of which is composed of two symmetrical first semi-circular hole walls and a first straight edge hole wall connecting the two ends of the two first semi-circular hole walls, forming an inner through hole and an outer wall of the elliptical cylinder. At one end of the elliptical cylindrical sleeve, there is an elliptical protrusion that protrudes to the side. The elliptical protrusion is composed of two symmetrical second semi-circles and a second straight edge connecting the two ends of the two second semi-circles. The length of the elliptical cylindrical sleeve is 1.4-1.65 times the outer wall diameter of the first semi-circular hole wall, and the length of the first straight edge hole wall of the elliptical cylindrical sleeve is 1.1-1.35 times the length of the hole wall of the elliptical cylindrical sleeve. The elliptical protrusion transitions at a right angle to the outer wall of the elliptical cylindrical sleeve. The manufacturing method includes the following steps: (1) The coiled material is fed into the cold heading forming machine and automatically cut into individual elliptical T-shaped bushing blanks for electric vehicle braking systems. The diameter of the coiled material is shorter than twice the outer radius of the first semi-circular hole wall and the sum of the length of the first straight side hole wall, and shorter than twice the inner radius of the first semi-circular hole wall and the sum of the length of the first straight side hole wall. The length of the blank is shorter than the length of the elliptical T-shaped bushing for electric vehicle braking systems. (2) The raw material is transferred to the No. 1 mold opening of the cold heading forming machine. After cold heading in the No. 1 mold, the front end of the No. 1 molded product is flattened and the rear end is rounded. (3) The No. 1 molded product is transferred to the No. 2 mold opening and cold-forged in the No. 2 mold, so that the front end of the No. 2 molded product is flattened and the rear end is forged into a rounded corner, and the No. 2 molded product is forged into a first elliptical cylinder whose cross-sectional outer contour is consistent with the outer contour of the elliptical cylinder sleeve. (4) The No. 2 molded product is transferred to the No. 3 mold opening and cold-forged in the No. 3 mold to pre-forge the elliptical head of the first elliptical cylinder. The outer contour of the elliptical head is consistent with the elliptical protrusion, and its thickness is thinner than the thickness of the elliptical protrusion. The elliptical head is then transitioned to the remaining surface of the first elliptical cylinder through a bevel to form the No. 3 molded product. The portion of the elliptical head that protrudes laterally from the surface of the remaining first elliptical cylinder, including the bevel portion, is used to form the elliptical protrusion. (5) The No. 3 molded product is transferred to the No. 4 mold opening and cold-forged in the No. 4 mold to make the front end of the No. 4 molded product have a positioning hole. The amount of metal transferred by the upsetting positioning hole is used to increase the thickness of the elliptical head. (6) The No. 4 molded product is transferred to the No. 5 mold opening. After cold heading in the No. 5 mold, the front end of the No. 4 molded product is headed to form a pre-headed hole for the inner through hole of the elliptical cylinder, and the rear end is headed to form a positioning hole, thus forming the No. 5 molded product. The outline of the pre-headed hole for the inner through hole of the elliptical cylinder is consistent with the outline of the inner through hole of the elliptical cylinder. The No. 5 molded product is extended until the remaining part excluding the length occupied by the elliptical head and the inclined surface is consistent with the length of the elliptical cylinder sleeve. The pre-headed hole for the inner through hole of the elliptical cylinder is separated from the positioning hole of the No. 5 molded product by the iron core to be drilled. (7) The No. 5 molded product is transferred to the No. 6 mold opening and cold-forged in the No. 6 mold to forge the front end of the No. 5 molded product into the elliptical protrusion. The elliptical protrusion transitions at a right angle with the outer wall of the elliptical cylinder sleeve to form the No. 6 molded product. (8) The No. 6 molded product is transferred to the No. 7 mold opening and cold-forged in the No. 7 mold to break through the iron core of the No. 6 molded product and make the elliptical T-shaped bushing for the electric vehicle braking system.

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