Manufacturing method of triangular arm connecting pin of chassis under support for vehicle

Abstract

The application provides a manufacturing method of a connecting pin of a triangular arm of a chassis lower support for vehicles. The connecting pin of the triangular arm of the chassis lower support for vehicles is manufactured by designing a blank capable of being manufactured by a cold extrusion process, then performing turning and repairing diameters of two ends of the blank, flattening two ends, turning and repairing diameters of the rod and the flange, and drilling the connecting handle. The application can apply the cold extrusion process, improve the comprehensive performance of the product, reduce material loss, and improve efficiency.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a connecting pin for the triangular arm of a vehicle chassis lower bracket. Background Technology

[0002] The chassis lower bracket triangular arm connecting pin is an important automotive component, widely used in the chassis connection system of automobile manufacturing, and its quality directly affects the driving safety of the vehicle.

[0003] The connecting pin of the triangular arm of the vehicle chassis lower bracket has the following shape characteristics: both ends are flat connecting handles, the middle is a connecting cylinder, the two ends of the connecting cylinder are flanges coaxial with the connecting cylinder, the connecting handle is located on the flange, the connecting handle is located in the middle of the flange, the bottom of the connecting handle passes through the center of the flange, both ends of the connecting handle are provided with through holes, the bottom of the connecting handle is a necked section, the width of the necked section is smaller than the diameter of the connecting cylinder; of the two ends, the flange at the first end has a larger diameter than the flange at the second end, the maximum width and length of the connecting handle at the first end are both larger than the maximum width and length of the connecting handle at the second end, the width of the connecting handle at the first end is smaller than the diameter of the flange at the first end, the width of the connecting handle at the second end is smaller than the diameter of the flange at the second end, and the maximum width of both the connecting handle at the first end and the connecting handle at the second end is larger than the diameter of the connecting cylinder.

[0004] Currently, most of the chassis lower bracket triangular arm connecting pins used in the domestic and international markets are mainly produced through machining. This process has problems such as high material loss, long production cycle, and low efficiency, and its overall performance can no longer meet the needs of the domestic and international automotive manufacturing industry. Summary of the Invention

[0005] The purpose of this invention is to provide a manufacturing method for a vehicle chassis lower bracket triangular arm connecting pin, which utilizes a cold extrusion process to improve the overall performance of the product, reduce material waste, and increase efficiency. To this end, this invention adopts the following technical solution: A method for manufacturing a triangular arm connecting pin for a vehicle chassis lower bracket, wherein the triangular arm connecting pin for a vehicle chassis lower bracket has the following product shape characteristics: both ends are flat connecting handles, the middle is a connecting cylinder, both ends of the connecting cylinder are flanges coaxial with the connecting cylinder, the connecting handles are located on the flanges, the bottom of the connecting handles is located in the middle of the flanges and passes through the center of the flanges, both ends of the connecting handles are provided with through holes, the bottom of the connecting handles is a necked section, the width of the necked section is smaller than the diameter of the connecting cylinder; of the two ends, the flange at the first end has a larger diameter than the flange at the second end, the maximum width and length of the connecting handle at the first end are both larger than the maximum width and length of the connecting handle at the second end, the width of the connecting handle at the first end is smaller than the diameter of the flange at the first end, the width of the connecting handle at the second end is smaller than the diameter of the flange at the second end, and the maximum width of both the connecting handle at the first end and the connecting handle at the second end is larger than the diameter of the connecting cylinder; The characteristic feature is that the connecting pin of the vehicle chassis lower bracket triangular arm is first manufactured into a blank with specific shape characteristics by cold extrusion process; the blank has the following shape characteristics: it includes three coaxial cylindrical sections, with a flange prototype between two adjacent cylindrical sections, the total length of the blank is the same as the total length of the connecting pin of the vehicle chassis lower bracket triangular arm, the diameter of the middle cylinder is the same as the diameter of the connecting cylinder, but the length is shorter than the connecting cylinder, the thickness of the two flange prototypes is greater than the thickness of the flanges at both ends of the connecting pin of the vehicle chassis lower bracket triangular arm, and the flange at the first end... The thickness and diameter of the prototype are both greater than the thickness and diameter of the flange at the first end. The thickness and diameter of the prototype of the flange at the first end are both greater than the thickness and diameter of the flange at the first end. The thickness and diameter of the prototype of the flange at the second end are both greater than the thickness and diameter of the flange at the second end. The diameter of the intermediate cylinder is greater than the diameter of the cylinder at the first end. The diameter of the cylinder at the first end is greater than the diameter of the cylinder at the second end. The sum of the length of the intermediate cylinder and the thickness of the prototype of the flanges at both ends is consistent with the sum of the thickness of the connecting cylinder of the triangular arm connecting pin of the vehicle chassis lower bracket and the thickness of the flanges at both ends. The cold extrusion process includes the following steps: (1-1) The coiled material is fed into the cold heading forming machine and automatically cut into individual automotive chassis lower bracket triangular arm connecting pin blanks. The diameter of the coiled material is close to the diameter of the connecting cylinder. (1-2) 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 No. 1 molded product is a cylinder with both the front and rear ends flattened and rounded corners. The diameter of the cylinder is the same as the diameter of the connecting cylinder. (1-3) The No. 1 molded product is moved to the No. 2 mold opening and cold-forged in the No. 2 mold to make the front end of the No. 2 molded product bound by a rod. The diameter and length of the bound rod part are the same as the diameter and length of the second end cylinder. The length of the No. 2 molded product is longer than the length of the No. 1 molded product. (1-4) The No. 2 molded product is moved to the No. 3 mold opening and cold-forged in the No. 3 mold to make the rear end of the No. 3 molded product bound by a rod. The diameter and length of the bound rod part are the same as the diameter and length of the first end cylinder. The length of the No. 3 molded product is longer than the length of the No. 2 molded product. (1-5) Move the No. 3 molded product to the No. 4 mold opening and cold forge it in the No. 4 mold. First, forge the large flange prototype, that is, forge the rounded corners of the rear end of the No. 3 molded product. At the same time, forge the flange prototype of the first end of the cylindrical section remaining after the two ends are bound by the rod. (1-6) The product made from mold No. 4 is transferred to the opening of mold No. 5. After cold heading in mold No. 5, the front end of the tie rod of the product made from mold No. 4 is rounded. At the same time, the second end of the remaining cylindrical section after the tie rods are formed into the flange shape of the second end is headed out. The main mold of mold No. 5 is provided with two molds along the circumferential direction. A compression spring is set between the two molds. The two molds correspond to the position of the upper end of the second flange shape to form the blank. The manufacturing method further performs the following manufacturing steps on the blank: (2) The rod diameters at both ends are machined to form a rotating upper head with a neck and a rotating lower head with a neck. The amount of metal remaining above the first flange prototype after machining corresponds to the amount of metal of the first connecting handle, and the amount of metal below the second flange prototype corresponds to the amount of metal of the second connecting handle. (3) Flatten both ends to form a first end connecting handle with a necked section at the bottom that has not yet been punched and a second end connecting handle with a necked section at the bottom that has not yet been punched. (4) Modify the rod diameter and flange outer diameter, that is, modify the diameter and thickness of the first end flange prototype to be consistent with the first end flange, modify the diameter and thickness of the second end flange prototype to be consistent with the second end flange, and form the connecting cylinder by reducing the cylinder length increased by reducing the thickness of the first end flange prototype and the second end flange prototype. (5) Drill holes in the connecting handle to form the connecting pin of the triangular arm of the vehicle chassis lower bracket.

[0006] Furthermore, the surface of the connecting handle is embossed between the diameter of the repair rod and the outer diameter of the flange.

[0007] By employing the technical solution of this invention, a new multi-station cold extrusion molding technology is used to form the blank in one step, followed by secondary processing to complete the product manufacturing. This saves materials, increases production efficiency, and reduces waste of manpower and materials. The basic blank formed by cold extrusion utilizes the principle of plastic deformation of metal materials, resulting in a more robust structure, higher safety, and stronger load-bearing capacity. The original processing method required 1943g of material, while the improved method only requires 796g, saving 59% of material. Attached Figure Description

[0008] Figure 1 This is a flowchart illustrating the cold extrusion manufacturing process of the blank according to the present invention.

[0009] Figure 2a and Figure 2b These are the front view and side view of the finished product after cold extrusion and end machining according to the present invention.

[0010] Figure 3a and 3b These are the front view and side view of the finished product after both ends have been machined and then flattened.

[0011] Figure 4 This is the front view of the finished product after both ends have been flattened and then embossed.

[0012] Figure 5 This is the front view of the finished product after the prototype of the repair flange has been completed.

[0013] Figure 6 This is the front view of the finished product after drilling holes at both ends.

[0014] Figure 7 This is a schematic diagram of the forming process of the flange prototype at the second end of die No. 5 in the cold extrusion manufacturing of this invention. Detailed Implementation

[0015] Referring to the accompanying drawings, the vehicle chassis lower bracket triangular arm connecting pin 100 manufactured according to the present invention has the following product shape features: connecting handles 101 and 102 at both ends are flat, and a connecting cylinder 105 is located in the middle. The two ends of the connecting cylinder 105 are flanges 103 and 104 coaxial with the connecting cylinder 103. The connecting handle 101 at the first end is located on the first flange 103, and the connecting handle 102 at the second end is located on the second flange 104. The bottoms of the connecting handles 101 and 102 are located in the middle of the flanges 103 and 104, respectively, passing through the centers of the flanges 103 and 104. Through holes 1011 and 1021 are respectively provided in the connecting handles 101 and 102 at both ends for connecting... The bottoms of handles 101 and 102 are respectively necked sections 1012 and 1022, the width of which is smaller than the diameter of the connecting cylinder 105. At both ends, the flange 103 at the first end has a larger diameter than the flange 104 at the second end. The maximum width and length of the connecting handle 101 at the first end are both larger than the maximum width and length of the connecting handle at the second end. The width of the connecting handle 101 at the first end is smaller than the diameter of the flange 103 at the first end. The width of the connecting handle 102 at the second end is smaller than the diameter of the flange 104 at the second end. The maximum width of both the connecting handle 101 at the first end and the connecting handle 102 at the second end is larger than the diameter of the connecting cylinder 105.

[0016] The preparation method of the present invention designs a blank 200 that facilitates the subsequent formation of connecting handles 101 and 102, strengthens and ensures the overall strength of connecting handles 101 and 102 during forming, as well as the strength of flanges 103 and 104, and can be manufactured using a cold extrusion process. The blank 200 has the following shape characteristics: it includes three coaxial cylindrical sections 201, 202, and 205; flange prototypes 203 and 204 are located between adjacent cylindrical sections; the total length of the blank 200 is approximately equal to the total length of the connecting pin 100 of the vehicle chassis lower bracket triangular arm; the diameter of the middle cylinder 205 is the same as the diameter of the connecting cylinder 105, but its length is shorter than that of the connecting cylinder 105; the thickness and diameter of the flange prototype 203 at the first end are both greater than the thickness of the flange 103 at the first end. The thickness and diameter of the second-end flange prototype 204 are both greater than the thickness and diameter of the second-end flange 104, respectively. The diameter of the middle cylinder 205 is greater than the diameter of the first-end cylinder 201, and the diameter of the first-end cylinder 201 is greater than the diameter of the second-end cylinder 202. The sum of the length of the middle cylinder 205 and the thickness of the two end flange prototypes 203 and 204 is basically equal to the sum of the thickness of the connecting cylinder 105 of the vehicle chassis lower bracket triangular arm connecting pin and the thickness of the two end flanges 103 and 104.

[0017] Reference Figure 1 The cold extrusion process includes the following steps: (1-1) The coiled material is fed into the cold heading forming machine and automatically cut into individual automotive chassis lower bracket triangular arm connecting pin blanks 300. The diameter of the coiled material is as close as possible to the diameter of the connecting cylinder 105. The length of the blank 300 is greater than the length of the blank 200, and is used to form the flange prototypes 203 and 204.

[0018] (1-2) The raw material 300 is transferred to the first mold opening of the cold heading forming machine. After cold heading in the first mold, the first molded product 1 is a cylinder 13 with both the front and rear ends flattened and rounded corners 11 and 12. The diameter of the cylinder 13 is basically the same as the diameter of the connecting cylinder 105. In the subsequent cold heading steps, there is only a slight change in diameter caused by the mold.

[0019] (1-3) The No. 1 molded product is moved to the No. 2 mold opening and cold-forged in the No. 2 mold to make the front end of the No. 2 molded product 2 bound by a rod. The diameter and length of the bound rod part 21 are the same as the diameter and length of the second end cylinder 202. The metal of the bound rod part 21 will be used to form the connecting handle 102 of the second end without needing to be transferred from elsewhere. The length of the No. 2 molded product 2 is longer than the length of the No. 1 molded product 1.

[0020] (1-4) The No. 2 molded product 2 is transferred to the No. 3 mold opening and cold-forged in the No. 3 mold to make the rear end of the No. 3 molded product 3 bound with a rod. The diameter and length of the rod part 31 are the same as the diameter and length of the first end cylinder 201. The metal of the rod part 31 will be used to form the connecting handle 101 of the first end without needing to be transferred from other places. The length of the No. 3 molded product 3 is longer than the length of the No. 2 molded product 2. The remaining cylindrical section 32 after both ends are bound with rods is greater than the length of the connecting cylinder 105. It will be used to form the flange prototypes 203 and 204 with a thickness greater than that of flanges 103 and 104. In the subsequent flattening operation, the strength of flanges 103 and 104, connecting handles 101 and 102 and the connection strength between them can be guaranteed.

[0021] (1-5) Move the No. 3 molded product 3 to the No. 4 mold opening and cold forge it in the No. 4 mold. First, forge the large flange prototype, that is, forge the rounded corner 41 at the rear end of the No. 3 molded product 3 to form the first end cylinder 201. At the same time, forge the first end of the remaining cylindrical section 32 after the two ends are bound by the rod to form the first end flange prototype 203. The amount of metal forging the flange prototype 203 comes from the first end of the cylindrical section 32 (the upper end according to the placement position in the figure), and make the No. 4 molded product 4.

[0022] (1-6) The No. 4 molded product 4 is transferred to the No. 5 mold opening. After cold forging in the No. 5 mold, the front end of the tie rod of the No. 4 molded product 4 is forged with a rounded corner 51 to form the second end cylinder 202. At the same time, the second end of the remaining cylindrical section 32 after both ends are tied with the tie rod (the lower end is placed in the figure) is forged with the flange prototype 204. The remaining cylindrical section is the middle cylinder 205, thus making the blank 200.

[0023] Reference Figure 7 The main mold 400 of the fifth mold is a two-piece mold, which upsets the flange prototype 204 at the second end while keeping other parts of the blank 200 unchanged. The two-piece mold consists of two single-piece molds 401 along the circumferential direction, with a compression spring between them. Reference numeral 402 indicates the hole for the compression spring. The mold sleeve 403 of the main mold is an inverted cone shape. The outer circumferential surfaces of the two molds match the inverted cone shape of the mold sleeve 403, allowing the two molds to extend, retract, and rise under the guidance of the inverted cone shape and the compression spring, facilitating mold closing and demolding. The two molds have cylindrical cavity sections 404 corresponding to the diameter and length of the central cylinder 205. A mold core 406 and a rear ejector 407 are provided below the main mold 400. A cavity 405 corresponding to the second end cylinder 202 is provided at the upper end of the mold core 406. An interval 408 corresponding to the thickness of the flange prototype 204 at the second end is provided between the upper end of the mold core 406 and the lower limit position of the main mold 400. The rear ejector 207 can pass through the mold core 206 from bottom to top.

[0024] The manufacturing method further performs the following manufacturing steps on the blank: (2) The diameters of both ends of the rod are machined to form a rotating upper head 501 with a neck 5011 and a rotating lower head 502 with a neck 5021. The amount of metal remaining above the first flange prototype 203 after machining corresponds to the amount of metal of the first connecting handle 101, and the amount of metal above the second flange prototype 204 corresponds to the amount of metal of the second connecting handle 102. This facilitates the subsequent flattening operation.

[0025] (3) The upper head 501 of the rotary body type with neck 5011 and the lower head 502 of the rotary body type with neck 5021 are flattened by means of flattening. The flattening is carried out on the basis of a thicker flange prototype, which is convenient to ensure structural strength, and forms the first end connecting handle 601 with the necked section 6011 at the bottom and the second end connecting handle 602 with the necked section 6021 at the bottom.

[0026] (4) After the flattening operation, the diameter of the rod and the outer diameter of the flange are modified. That is, the diameter and thickness of the first end flange prototype 203 are modified to be consistent with the first end flange to form the first end flange 103. The diameter and thickness of the second end flange prototype 204 are modified to be consistent with the second end flange to form the second end flange 104. The increased cylinder length by reducing the thickness of the first end flange prototype 203 and the second end flange prototype 204, together with the intermediate cylinder 205, forms the connecting cylinder 105. In this way, the flanges 103, 104 and the connecting cylinder 105 can be formed as desired, while ensuring that the quality of the connecting handles 101 and 102 is as good as the load-bearing performance of cold heading.

[0027] (5) Drill holes in the connecting handle to form the through holes 1011 and 1021, forming the vehicle chassis lower bracket triangular arm connecting pin 100.

[0028] Before machining the rod diameter and flange outer diameter, the surfaces of the connecting handles 601 and 602 can be embossed with a 700-degree pattern.

[0029] 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.

[0030] It should be noted that the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. The terms "installed," "set," "equipped with," "connected," "connected," and "sleeve-in" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral construction; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] In the description of this invention, it should be understood that the terms "one end," "the other end," "outer side," "inner side," "horizontal," "end," "length," "outer end," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. The terms "first" and "second" are also used only for the sake of brevity in description and do not indicate or imply relative importance.

[0032] Furthermore, in practicing the claims of this invention, those skilled in the art can understand and influence variations to the disclosed embodiments through a study of the drawings, the disclosure, and the appended claims. Additionally, in the claims and description, words such as "comprising" and "containing" do not exclude other elements or steps, and non-plural nouns do not exclude their plural forms.

Claims

1. A method for manufacturing a triangular arm connecting pin for a vehicle chassis lower bracket, wherein the triangular arm connecting pin for a vehicle chassis lower bracket has the following product shape characteristics: both ends are flat connecting handles, the middle is a connecting cylinder, both ends of the connecting cylinder are flanges coaxial with the connecting cylinder, the connecting handles are located on the flanges, the bottom of the connecting handles is located in the middle of the flanges and passes through the center of the flanges, both ends of the connecting handles are provided with through holes, the bottom of the connecting handles is a necked section, the width of the necked section is smaller than the diameter of the connecting cylinder; of the two ends, the flange at the first end has a larger diameter than the flange at the second end, the maximum width and length of the connecting handle at the first end are both larger than the maximum width and length of the connecting handle at the second end, the width of the connecting handle at the first end is smaller than the diameter of the flange at the first end, the width of the connecting handle at the second end is smaller than the diameter of the flange at the second end, and the maximum width of both the connecting handle at the first end and the connecting handle at the second end is larger than the diameter of the connecting cylinder; Its features The vehicle chassis lower bracket triangular arm connecting pin is first manufactured into a blank with specific shape characteristics using a cold extrusion process. The blank has the following shape characteristics: it includes three coaxial cylindrical sections, with a flange prototype between adjacent cylindrical sections. The total length of the blank is the same as the total length of the vehicle chassis lower bracket triangular arm connecting pin. The diameter of the middle cylinder is the same as the diameter of the connecting cylinder, but its length is shorter. The thickness of both flange prototypes is greater than the thickness of the flanges at both ends of the vehicle chassis lower bracket triangular arm connecting pin. The flange prototype at the first end... The thickness and diameter of the intermediate cylinder are both greater than the thickness and diameter of the flange at the first end. The thickness and diameter of the prototype flange at the first end are both greater than the thickness and diameter of the flange at the first end. The thickness and diameter of the prototype flange at the second end are both greater than the thickness and diameter of the flange at the second end. The diameter of the intermediate cylinder is greater than the diameter of the cylinder at the first end. The diameter of the cylinder at the first end is greater than the diameter of the cylinder at the second end. The sum of the length of the intermediate cylinder and the thickness of the prototype flanges at both ends is consistent with the sum of the thickness of the connecting cylinder of the triangular arm connecting pin of the vehicle chassis lower bracket and the thickness of the flanges at both ends. The cold extrusion process includes the following steps: (1-1) The coiled material is fed into the cold heading forming machine and automatically cut into individual automotive chassis lower bracket triangular arm connecting pin blanks. The diameter of the coiled material is close to the diameter of the connecting cylinder. (1-2) 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 No. 1 molded product is a cylinder with both the front and rear ends flattened and rounded corners. The diameter of the cylinder is the same as the diameter of the connecting cylinder. (1-3) The No. 1 molded product is moved to the No. 2 mold opening and cold-forged in the No. 2 mold to make the front end of the No. 2 molded product bound by a rod. The diameter and length of the bound rod part are the same as the diameter and length of the second end cylinder. The length of the No. 2 molded product is longer than the length of the No. 1 molded product. (1-4) The No. 2 molded product is moved to the No. 3 mold opening and cold-forged in the No. 3 mold to make the rear end of the No. 3 molded product bound by a rod. The diameter and length of the bound rod part are the same as the diameter and length of the first end cylinder. The length of the No. 3 molded product is longer than the length of the No. 2 molded product. (1-5) Move the No. 3 molded product to the No. 4 mold opening and cold forge it in the No. 4 mold. First, forge the large flange prototype, that is, forge the rounded corners of the rear end of the No. 3 molded product. At the same time, forge the flange prototype of the first end of the cylindrical section remaining after the two ends are bound by the rod. (1-6) The product made from mold No. 4 is transferred to the opening of mold No.

5. After cold heading in mold No. 5, the front end of the tie rod of the product made from mold No. 4 is rounded. At the same time, the second end of the remaining cylindrical section after the tie rods are formed into the flange shape of the second end is formed. The main mold of mold No. 5 is provided with two molds along the circumferential direction. A compression spring is set between the two molds. The two molds correspond to the position of the upper end of the flange shape of the second end to form the blank. The manufacturing method further performs the following manufacturing steps on the blank: (2) The rod diameters at both ends are machined to form a rotating upper head with a neck and a rotating lower head with a neck. The amount of metal remaining above the first flange prototype after machining corresponds to the amount of metal of the first connecting handle, and the amount of metal below the second flange prototype corresponds to the amount of metal of the second connecting handle. (3) Flatten both ends to form a first end connecting handle with a necked section at the bottom that has not yet been punched and a second end connecting handle with a necked section at the bottom that has not yet been punched. (4) Modify the rod diameter and flange outer diameter, that is, modify the diameter and thickness of the first end flange prototype to be consistent with the first end flange, modify the diameter and thickness of the second end flange prototype to be consistent with the second end flange, and form the connecting cylinder by reducing the cylinder length increased by reducing the thickness of the first end flange prototype and the second end flange prototype. (5) Drill holes in the connecting handle to form the connecting pin of the triangular arm of the vehicle chassis lower bracket.

2. The manufacturing method of the vehicle chassis lower bracket triangular arm connecting pin as described in claim 1, characterized in that... Embossing is performed on the surface of the connecting handle between the diameter of the repair rod and the outer diameter of the flange.

Images