Cold heading manufacturing method of chassis connecting and fixing pin for new energy vehicle

Abstract

The invention provides a cold heading manufacturing method of a chassis connecting and fixing pin for a new energy vehicle, which comprises the following steps of: shaping and leveling two ends, bundling a small rod diameter at the rear end, bundling the rod diameter at the front end, heading a middle flange and a step circle, heading the middle flange and six convex ribs, and heading a bottom end flange head to directly manufacture the chassis connecting and fixing pin for the new energy vehicle. Through the method, the raw material utilization rate and quality can be improved, the production efficiency is improved, the appearance size is uniform, and the product strength is high.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-station cold forging, and in particular to a cold forging manufacturing method for a chassis connecting fixing pin for a new energy vehicle. Background Art

[0002] The chassis connection fixing pin for new energy vehicles is an important automotive part used in the chassis connection system of new energy vehicles. Its quality directly affects the driving safety of new energy vehicles.

[0003] The outer structure of the chassis connecting fixing pin for new energy vehicles includes: an upper cylindrical rod body and a lower cylindrical rod body with the same center line, a middle flange located between the upper cylindrical rod body and the lower cylindrical rod body, and a flange head located at the bottom end; the distance from the top surface of the middle flange to the bottom surface of the flange head is basically the same as the length of the upper cylindrical rod body, the thickness of the middle flange is slightly thinner than the thickness of the bottom flange head, and the thickness of the middle flange is 10-20% of the length of the upper cylindrical rod body; the diameters of the upper cylindrical rod body and the lower cylindrical rod body are the same, and the top end of the upper cylindrical rod body has an arc-shaped transition top end; the middle flange includes a flange plate and an arc-shaped bottom thereof The transition section, the diameter of the flange is 2.6-3.3 times the diameter of the lower cylindrical rod, and the diameter of the bottom flange head is 1.25-1.45 of the diameter of the lower cylindrical rod; the upper end of the lower cylindrical rod has an arc-shaped transition connected with the arc-shaped transition section, the upper part of the lower cylindrical rod is closely connected to the middle flange, and is provided with six ribs, the length of the ribs is 50-75% of the diameter of the lower cylindrical rod, extending downward from the bottom end of the arc-shaped transition section, the six ribs are evenly distributed along the circumferential direction, and the distance from the protruding apex of the rib to the center line of the lower cylindrical rod is 0.9-1.1 times the radius of the bottom flange head.

[0004] Currently, most vehicle chassis connecting and fixing pins used in domestic and foreign markets are mainly produced through machining. This process has problems such as high material loss of processed products, long production cycle and low efficiency, and cannot meet the manufacturing needs of the above-mentioned shape of chassis connecting and fixing pins for new energy vehicles. Summary of the Invention

[0005] The purpose of the present invention is to provide a cold heading manufacturing method for connecting and fixing pins for chassis of new energy vehicles, which can manufacture the chassis of new energy vehicles through six-station cold heading, with high product strength and high production efficiency. To this end, the present invention adopts the following technical solutions: The invention discloses a cold heading manufacturing method for a chassis connecting and fixing pin for a new energy vehicle, characterized in that the outer structure of the chassis connecting and fixing pin for a new energy vehicle includes: an upper cylindrical rod body and a lower cylindrical rod body with the same center line, a middle flange located between the upper cylindrical rod body and the lower cylindrical rod body, and a flange head located at the bottom end; the distance from the top surface of the middle flange to the bottom surface of the flange head is substantially consistent with the length of the upper cylindrical rod body, the thickness of the middle flange is slightly thinner than the thickness of the bottom end flange head, and the thickness of the middle flange is 10-20% of the length of the upper cylindrical rod body; the diameters of the upper cylindrical rod body and the lower cylindrical rod body are consistent, and the top end of the upper cylindrical rod body has an arc-shaped transition top end; the middle method The flange includes a flange and an arc-shaped transition section at its lower portion. The diameter of the flange is 2.6-3.3 times the diameter of the lower cylindrical shaft, and the diameter of the bottom flange head is 1.25-1.45 times the diameter of the lower cylindrical shaft. The upper end of the lower cylindrical shaft has an arc-shaped transition that connects with the arc-shaped transition section. The upper portion of the lower cylindrical shaft is adjacent to the middle flange and is provided with six ribs. The rib length is 50-75% of the diameter of the lower cylindrical shaft and extends downward from the bottom end of the arc-shaped transition section. The six ribs are evenly distributed along the circumferential direction. The distance from the apex of the rib to the centerline of the lower cylindrical shaft is 0.9-1.1 times the radius of the bottom flange head. The manufacturing method comprises the following steps: (1) Feeding the round disc into a cold heading machine and automatically cutting it into a single raw material piece for connecting and fixing the chassis of a new energy vehicle, wherein the diameter of the round disc is close to the diameter of the bottom flange head, and the length of the raw material piece is shorter than the length of the connecting and fixing pin of the chassis of the new energy vehicle; (2) The raw material is transferred to the No. 1 mold port of the cold heading forming machine, and is cold headed in the No. 1 mold so that the front end and the rear end of the No. 1 molded product are flattened and the ends are both headed; (3) The molded product No. 1 is translated to the mouth of the mold No. 2, and is cold-forged in the mold No. 2, so that the rear portion of the molded product No. 2 is bounded, the diameter of the rear bounded rod is consistent with the diameter of the lower cylindrical rod body, the length of the bounded rod is consistent with the length of the lower cylindrical rod body, and the rear portion of the bounded rod and the portion not bounded are transitioned through a first arc surface transition section; (4) The molded product No. 2 is translated to the mouth of the mold No. 3, and is cold-forged in the mold No. 3, so that the front portion of the molded product No. 3 is bounded, the diameter of the front bounded rod is consistent with the diameter of the upper cylindrical rod body, and the length is slightly shorter than the upper cylindrical rod body. The front portion of the bounded rod and the portion not bounded are transitioned through a second arc surface transition section, and the total length of the front portion of the bounded rod and the second arc surface transition section is consistent with the length of the upper cylindrical rod body; (5) The molded product No. 3 is translated to the mold opening No. 4, and is cold-forged in the mold No. 4. The upper and middle parts of the unbound rod portion of the molded product No. 3 are forged into the front shape of the middle flange. The diameter of the front shape is smaller than the diameter of the flange plate and the thickness is thicker than the middle flange. The lower diameter of the unbound rod portion of the molded product No. 3 exceeds the rear part of the bound rod to form the six ribs and the arc-shaped transition at the upper end of the lower cylindrical rod; the front part of the bound rod and the second arc-shaped transition section are forged into the upper cylindrical rod and the arc-shaped transition top end of the upper cylindrical rod; (6) The finished product of the No. 4 mold is translated to the mouth of the No. 5 mold, and is cold-forged in the No. 5 mold so that the front shape of the middle flange of the finished product of the No. 4 mold is forged out of the middle flange. The middle flange includes the flange plate and the arc-shaped transition section at its lower part. The unbound rod portion and the first arc-shaped transition section are forged out of the six ribs and the upper end of the lower cylindrical rod body connected with the arc-shaped transition section, and the upper part of the lower cylindrical rod body on which the six ribs are based, thereby forming the front shape of the lower cylindrical rod body. The diameter of the front shape is consistent with the diameter of the lower cylindrical rod body, and the length is longer than the lower cylindrical rod body. The metal amount of the lower end exceeding the length of the lower cylindrical rod body is used to form the bottom flange head; (7) The finished product of the No. 5 mold is translated to the No. 6 mold mouth, and after cold forging in the No. 6 mold, the bottom flange head is forged from the lower end of the front shape of the lower cylindrical rod body, and the lower cylindrical rod body is formed at the same time; the main mold of the No. 6 mold is a three-piece mold along the circumferential direction, and a compression spring is set between the adjacent two molds. The mold core of the main mold is an inverted cone, and the outer circumferential surface of the three-piece mold is an inverted cone that matches the inverted cone of the mold core; the three-piece mold has an inwardly protruding fan-shaped segment corresponding to the outer shape of the lower cylindrical rod body and can form a hole that matches the lower cylindrical rod body. The rear end face of the inwardly protruding fan-shaped segment matches the upper end face of the bottom flange head, and the front end is provided with a profile that matches the shape of the rib, flange plate, arc transition section and the arc transition of the upper end of the lower cylindrical rod body. A rear top tube is set at the bottom of the main mold, and a positioning triangular ridge is set at the front end of the rear top tube.

[0006] The present invention can use a cold extrusion process to manufacture chassis connection fixing pins for new energy vehicles. Six cold extrusion processes, including shaping and leveling the two ends, constricting the small rod diameter at the rear end, constricting the rod diameter at the front end, upsetting the middle flange and step circle, upsetting the middle flange and six convex ribs, and upsetting the bottom flange head, are completed simultaneously in each mold. This directly manufactures the chassis connection fixing pins for new energy vehicles. The cold extrusion causes the material to undergo plastic deformation, changing its internal structure and improving the mechanical properties of the chassis connection fixing pins for new energy vehicles. By controlling the metal flow of each cold extrusion process, the six ribs of the middle flange cylinder and the upsetting tail flange that meet the shape and size requirements can be upset, ensuring product quality. The present invention uses multi-station cold extrusion molding technology, eliminating a large amount of lathe repair margin, achieving high material utilization, saving 15.9% of material, and achieving a production speed of up to 60 pieces per minute, which is highly efficient and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic diagram of the process from material cutting to fourth mold manufacturing in the manufacturing method of the present invention.

[0008] Figure 2 It is a schematic diagram of the process from the fifth mold manufacturing to the sixth mold manufacturing in the manufacturing method of the present invention.

[0009] Figure 3 This is a schematic diagram of the sixth mold forming process of the manufacturing method of the present invention. DETAILED DESCRIPTION

[0010] Reference Figure 1 、 Figure 2 、 Figure 3The outer structure of the chassis connecting fixing pin for new energy vehicles includes an upper cylindrical rod body 61 and a lower cylindrical rod body 62 with the same center line, a middle flange located between the upper cylindrical rod body 61 and the lower cylindrical rod body 62, and a flange head 63 at the bottom end. The distance L1 from the top surface of the middle flange to the bottom surface of the flange head is basically consistent with the length L2 of the upper cylindrical rod body. The thickness T1 of the middle flange is slightly thinner than the thickness of the bottom end flange head T2. The thickness of the middle flange is 10-20% of the length of the upper cylindrical rod body. The diameters of the upper cylindrical rod body 61 and the lower cylindrical rod body 62 are consistent. The top end of the upper cylindrical rod body 61 has an arc-shaped transition top end 611. The middle flange includes a flange plate 641 and a circular arc transition section 64 at its lower end. 2. The diameter of the flange 641 is 2.6-3.3 times the diameter of the lower cylindrical shaft 62, and the diameter of the bottom flange head 63 is 1.25-1.45 times the diameter of the lower cylindrical shaft 62. The upper end of the lower cylindrical shaft 62 has an arc transition 621 connected to the arc transition section 642. The upper part of the lower cylindrical shaft 62 is adjacent to the middle flange and is provided with six ribs 65. The length of the rib 65 is 50-75% of the diameter of the lower cylindrical shaft. It extends downward from the bottom end of the arc transition section 641. The six ribs 65 are evenly distributed along the circumferential direction. The distance from the protruding vertex 651 of the rib 65 to the center line of the lower cylindrical shaft 62 is 0.9-1.1 times the radius of the bottom flange head 63.

[0011] The cold heading manufacturing method comprises the following steps: (1) Feeding the round disc into a cold heading machine and automatically cutting it into a single raw material piece 10 for connecting and fixing the chassis of a new energy vehicle, wherein the diameter of the round disc is consistent with the diameter of the bottom flange head 63, and the length of the raw material piece 10 is shorter than the length of the connecting and fixing pin 6 of the chassis of the new energy vehicle; (2) The raw material is transferred to the No. 1 mold port of the cold heading machine, and is cold headed in the No. 1 mold so that the front end face and the rear end face of the No. 1 molded product 1 are flattened and the ends are both headed with guide angles 11 and 12.

[0012] (3) The molded product 1 is translated to the mouth of the mold No. 2, and is cold-forged in the mold No. 2, so that the rear portion 22 of the molded product 2 is bounded, the diameter of the rear bounded rod is consistent with the diameter of the lower cylindrical rod body 62, the length of the bounded rod is consistent with the length of the lower cylindrical rod body, and the rear portion 22 of the bounded rod and the portion 21 not bounded are transitioned through the first arc surface transition section 23.

[0013] (4) The molded product 2 is moved horizontally to the mouth of the mold 3 and cold-forged in the mold 3 so that the front portion 31 of the molded product 3 is bound. The diameter of the front bound portion is consistent with the diameter of the upper cylindrical rod 61 and the length is slightly shorter than the upper cylindrical rod. The front portion 31 of the bound rod and the portion 32 not bound are transitioned through the second arc surface transition section 33. The total length of the front portion 31 of the bound rod and the second arc surface transition section 33 is consistent with the length of the upper cylindrical rod. The metal amount of this part does not need to be involved in the forming of the middle flange, which helps to reduce the difficulty of cold forging and the forming quality, and improve the concentricity of the upper cylindrical rod 61 and the lower cylindrical rod 62. The rear portion 22 of the bound rod and the first arc surface transition section 23 remain unchanged, with only a slight difference caused by the die.

[0014] (5) The molded product 3 is translated to the mouth of the mold No. 4 and manufactured by cold heading in the mold No. 4. The upper and middle parts of the unbound rod portion 32 of the molded product 3 are forged into the front shape 41 of the middle flange. The diameter of the front shape 41 is smaller than the diameter of the flange 641 and the thickness is thicker than the middle flange. The metal amount of the front shape 4 is used to form the middle flange. The lower part 42 of the unbound rod portion of the molded product 3 is not cold headed in the mold No. 4. The part of its diameter exceeding the rear part 21 of the bound rod will be used in the subsequent cold heading to form the six ribs 65 and the arc-shaped transition 621 at the upper end of the lower cylindrical rod 62, which can reduce the subsequent metal transfer distance, reduce the difficulty of cold heading and improve the forming quality, as well as improve the concentricity of the upper cylindrical rod 61 and the lower cylindrical rod 62. The front portion 31 of the restrained rod and the second arcuate transition section 33 are formed into the upper cylindrical shaft 61 and its corresponding arcuate transition tip 611. Subsequent die-casting only produces minor variations, which can continuously improve surface quality. The rear portion 22 of the restrained rod and the first arcuate transition section 23 remain unchanged, with only minor variations caused by die-casting. This produces the fourth molded product 4.

[0015] (6) The molded product 4 is translated to the mouth of the mold No. 5, and is cold-forged in the mold No. 5, so that the front shape 41 of the middle flange of the molded product 4 is forged out of the middle flange, and the middle flange includes a flange plate 641 and an arc-shaped transition section 642 at its lower portion. The unbound rod portion 42 and the first arc-shaped transition section 23 are forged out of the six ribs 65 and the arc-shaped transition 621 at the upper end of the lower cylindrical rod 62 connected with the arc-shaped transition section 642, and the upper portion 622 of the lower cylindrical rod on which the six ribs 64 are based, thereby forming the front shape 51 of the lower cylindrical rod. The diameter of the front shape is consistent with the diameter of the lower cylindrical rod 62, and the length is longer than the lower cylindrical rod 62. The metal amount of the lower end exceeding the length of the lower cylindrical rod 62 is used to form the bottom flange head 63, so as to make the molded product 5 No. 5.

[0016] (7) The finished product 5 of the No. 5 mold is translated to the mouth of the No. 6 mold. After cold heading in the No. 6 mold, the bottom flange head 63 is formed on the lower end of the front shape 51 of the lower cylindrical rod body, and the lower cylindrical rod body 62 is formed at the same time. The other parts of the No. 5 mold product are only slightly different from those produced by the sleeve mold, and the chassis connecting fixing pin 6 for new energy vehicles is made. The main mold of the No. 6 mold is a three-piece mold 101 along the circumferential direction. A compression spring is set between the two adjacent molds 101. The mold core 103 of the main mold is an inverted cone. The outer peripheral surface of the three-piece mold 101 is an inverted cone that matches the inverted cone of the mold core 103; the three-piece mold 103 has an inwardly protruding fan-shaped segment 104 corresponding to the outer shape of the lower cylindrical rod body 62 and can form a hole that matches the lower cylindrical rod body 62. The rear end surface of the inwardly protruding fan-shaped segment 104 is aligned with the bottom The upper end surface of the end flange head 63 matches the shape of the rib 65, flange 641, arcuate transition section 642, and the arcuate transition section 621 at the upper end of the lower cylindrical shaft 62. A rear push tube 102 is positioned at the bottom of the main mold. A positioning triangular ridge 105 is provided at the front end of the rear push tube 102. The top edge of the positioning triangular ridge 105 aligns with the centerline, improving the stability of the push tube's motion when stamping the bottom end of the lower cylindrical shaft front form 51. This also enhances the concentricity of the upper and lower cylindrical shafts 61, 62. Reference numeral 106 in red in the figure denotes the front mold.

[0017] 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 any technician in this field within the field of the present invention are included in the protection scope of the present invention.

Claims

1. A cold heading manufacturing method for chassis connection fixing pins for new energy vehicles, characterized in that: The outer structure of the chassis connecting fixing pin for new energy vehicles includes: an upper cylindrical rod body and a lower cylindrical rod body with the same center line, a middle flange located between the upper cylindrical rod body and the lower cylindrical rod body, and a flange head located at the bottom end; the distance from the top surface of the middle flange to the bottom surface of the flange head is basically the same as the length of the upper cylindrical rod body, the thickness of the middle flange is slightly thinner than the thickness of the bottom flange head, and the thickness of the middle flange is 10-20% of the length of the upper cylindrical rod body; the diameters of the upper cylindrical rod body and the lower cylindrical rod body are the same, and the top end of the upper cylindrical rod body has an arc-shaped transition top end; the middle flange includes a flange plate and an arc-shaped bottom thereof The transition section has a flange diameter of 2.6-3.3 times the diameter of the lower cylindrical shaft, and the diameter of the bottom flange head is 1.25-1.45 times the diameter of the lower cylindrical shaft; the upper end of the lower cylindrical shaft has an arc-shaped transition that connects with the arc-shaped transition section, and the upper part of the lower cylindrical shaft is closely connected to the middle flange and is provided with six ribs, each rib length being 50-75% of the diameter of the lower cylindrical shaft, extending downward from the bottom end of the arc-shaped transition section, and the six ribs are evenly distributed along the circumferential direction, and the distance from the convex apex of the rib to the center line of the lower cylindrical shaft is 0.9-1.1 times the radius of the bottom flange head; The manufacturing method comprises the following steps: (1) Feeding the round disc into a cold heading machine and automatically cutting it into a single raw material piece for connecting and fixing the chassis of a new energy vehicle, wherein the diameter of the round disc is close to the diameter of the bottom flange head, and the length of the raw material piece is shorter than the length of the connecting and fixing pin of the chassis of the new energy vehicle; (2) The raw material is transferred to the No. 1 mold port of the cold heading forming machine, and is cold headed in the No. 1 mold so that the front end and the rear end of the No. 1 molded product are flattened and the ends are both headed; (3) The molded product No. 1 is translated to the mouth of the mold No. 2, and is cold-forged in the mold No. 2, so that the rear portion of the molded product No. 2 is bounded, the diameter of the rear bounded rod is consistent with the diameter of the lower cylindrical rod body, the length of the bounded rod is consistent with the length of the lower cylindrical rod body, and the rear portion of the bounded rod and the portion not bounded are transitioned through a first arc surface transition section; (4) The molded product No. 2 is translated to the mouth of the mold No. 3, and is cold-forged in the mold No. 3, so that the front portion of the molded product No. 3 is bounded, the diameter of the front bounded rod is consistent with the diameter of the upper cylindrical rod body, and the length is slightly shorter than the upper cylindrical rod body. The front portion of the bounded rod and the portion not bounded are transitioned through a second arc surface transition section, and the total length of the front portion of the bounded rod and the second arc surface transition section is consistent with the length of the upper cylindrical rod body; (5) The molded product No. 3 is translated to the mold opening No. 4, and is cold-forged in the mold No.

4. The upper and middle parts of the unbound rod portion of the molded product No. 3 are forged into the front shape of the middle flange. The diameter of the front shape is smaller than the diameter of the flange plate and the thickness is thicker than the middle flange. The lower diameter of the unbound rod portion of the molded product No. 3 exceeds the rear part of the bound rod to form the six ribs and the arc-shaped transition at the upper end of the lower cylindrical rod; the front part of the bound rod and the second arc-shaped transition section are forged into the upper cylindrical rod and the arc-shaped transition top end of the upper cylindrical rod; (6) The finished product of the No. 4 mold is translated to the mouth of the No. 5 mold, and is cold-forged in the No. 5 mold so that the front shape of the middle flange of the finished product of the No. 4 mold is forged out of the middle flange. The middle flange includes the flange plate and the arc-shaped transition section at its lower part. The unbound rod portion and the first arc-shaped transition section are forged out of the six ribs and the upper end of the lower cylindrical rod body connected with the arc-shaped transition section, and the upper part of the lower cylindrical rod body on which the six ribs are based, thereby forming the front shape of the lower cylindrical rod body. The diameter of the front shape is consistent with the diameter of the lower cylindrical rod body, and the length is longer than the lower cylindrical rod body. The metal amount of the lower end exceeding the length of the lower cylindrical rod body is used to form the bottom flange head; (7) The finished product of the No. 5 mold is translated to the No. 6 mold mouth, and after cold forging in the No. 6 mold, the bottom flange head is forged from the lower end of the front shape of the lower cylindrical rod body, and the lower cylindrical rod body is formed at the same time; the main mold of the No. 6 mold is a three-piece mold along the circumferential direction, and a compression spring is set between the adjacent two molds. The mold core of the main mold is an inverted cone, and the outer circumferential surface of the three-piece mold is an inverted cone that matches the inverted cone of the mold core; the three-piece mold has an inwardly protruding fan-shaped segment corresponding to the outer shape of the lower cylindrical rod body and can form a hole that matches the lower cylindrical rod body. The rear end face of the inwardly protruding fan-shaped segment matches the upper end face of the bottom flange head, and the front end is provided with a profile that matches the shape of the rib, flange plate, arc transition section and the arc transition of the upper end of the lower cylindrical rod body. A rear top tube is set at the bottom of the main mold, and a positioning triangular ridge is set at the front end of the rear top tube.

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