Six-station cold extrusion manufacturing method for inner tube with toothed connection for automobile transmission system

Abstract

The invention provides a six-station cold extrusion manufacturing method for a toothed inner tube for an automobile transmission system. The toothed inner tube for an automobile transmission system is directly manufactured by cold extrusion six-die manufacturing. The method of the invention can improve the utilization rate and quality of raw materials and improve production efficiency, and the appearance quality is high and the product strength is high.

Description

Technical Field

[0001] The invention relates to the technical field of multi-station cold heading, in particular to a method for manufacturing a toothed connecting inner tube for an automobile transmission system. Background Art

[0002] The inner tube connected with a toothed belt for an automobile transmission system is an important component in the automobile transmission system. The main body of the outer structure of the inner tube connected with a toothed belt for an automobile transmission system is a rotating body structure with an I-shaped longitudinal section. The rotating body structure includes a main cylindrical section and a first truncated cone and a second truncated cone respectively arranged at both ends of the main cylindrical section, wherein the diameter of the second truncated cone is slightly larger than the diameter of the first truncated cone, a central through hole is arranged at the center of the rotating body structure, and a plurality of anti-slip teeth are radially arranged on the end face of the first truncated cone; wherein the diameter of the first truncated cone is 135-145% of the diameter of the main cylindrical section, the diameter of the second truncated cone is 150-160% of the diameter of the main cylindrical section, the diameter of the central through hole is 50-60% of the diameter of the main cylindrical section, the first truncated cone is thinner than the second truncated cone, the height of the second truncated cone is 35-45% of the length of the main cylindrical section, and the height of the first truncated cone is 20-30% of the length of the main cylindrical section.

[0003] In the past, the inner tubes of the toothed connection used in automobile transmission systems were mainly machined, which was slow, costly, and resulted in much material waste. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for manufacturing a toothed inner tube for an automobile transmission system, which can directly manufacture the toothed inner tube for an automobile transmission system by a multi-station cold extrusion method, thereby improving the utilization rate and quality of raw materials and improving production efficiency. To this end, the present invention adopts the following technical solutions:

[0005] A six-station cold extrusion manufacturing method for a toothed inner tube for an automobile transmission system, characterized in that the main body of the outer structure of the toothed inner tube for an automobile transmission system is a rotating body structure with an I-shaped longitudinal section, the rotating body structure comprises a main cylindrical section and a first truncated cone and a second truncated cone respectively arranged at both ends of the main cylindrical section, wherein the diameter of the second truncated cone is slightly larger than the diameter of the first truncated cone, a central through hole is arranged at the center of the rotating body structure, and a plurality of anti-slip teeth are arranged on the end surface of the first truncated cone; wherein the diameter of the first truncated cone is 135-145% of the diameter of the main cylindrical section, the diameter of the second truncated cone is 150-160% of the diameter of the main cylindrical section, the diameter of the central through hole is 50-60% of the diameter of the main cylindrical section, the first truncated cone is thinner than the second truncated cone, the height of the second truncated cone is 35-45% of the length of the main cylindrical section, and the height of the first truncated cone is 20-30% of the length of the main cylindrical section;

[0006] The manufacturing method comprises the following steps:

[0007] (1) Feeding the disc round material into a cold heading machine and automatically shearing it into a single raw material piece of the inner tube with a toothed connection for the automobile transmission system, wherein the diameter of the disc round material is close to the diameter of the main cylindrical section, and the length of the raw material piece is longer than the length of the inner tube with a toothed connection;

[0008] (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 diameter of the No. 1 molded product is consistent with the diameter of the main cylindrical section, and the rear end is rounded and the first center positioning hole is formed;

[0009] (3) The molded product No. 1 is translated to the mouth of the mold No. 2, and the molded product No. 1 is pre-upset. The amount of metal required for forming the second truncated cone is basically derived from the large head of the molded product No. 2 formed by the pre-upset large head. The diameter of the cylindrical section at the rear of the large head of the molded product No. 2 is consistent with the diameter of the molded product No. 1; the diameter of the large head of the molded product No. 2 is between the diameters of the first truncated cone and the second truncated cone. The large head of the molded product No. 2 is a three-section structure, with a cylindrical middle and a truncated cone at the front end. A positioning hole is upset at the top of the truncated cone. The height of the truncated cone is lower than the height of the middle cylinder. The rear end is a curved transition section that transitions with the cylindrical section of the molded product No. 2, and the die surface line of the mold No. 2 is located in the middle of the middle cylinder.

[0010] (4) The finished product of the No. 2 mold is translated to the opening of the No. 3 mold. The large end of the No. 2 molded product is roughened and flattened in the No. 3 mold to form the front shape of the second truncated cone. The diameter of the front shape is consistent with the diameter of the second truncated cone, and the height is slightly lower than the height of the second truncated cone. In addition, a second center positioning hole is upset at the front end. The amount of metal required to increase the height of the front shape to the height of the second truncated cone is derived from the amount of metal transferred by digging the hole in the front shape. For the No. 3 mold, the No. 2 molded product is completely cold extruded in the main mold.

[0011] (5) The finished product of the No. 3 mold is translated to the mouth of the No. 4 mold, and is cold-forged in the No. 4 mold. For the large end of the No. 3 molded product, a center blind hole is cold-extruded on the basis of the second center positioning hole to form the second truncated cone. The bottom thickness of the center blind hole meets the requirements of punching the iron core. The amount of metal transfer generated by digging the center blind hole in the cylindrical section of the No. 3 molded product is used to extend the length of the cylindrical section to form the cylindrical section of the No. 4 molded product, whose diameter is consistent with the diameter of the main cylindrical section; the diameter of the center blind hole is consistent with the diameter of the center through hole; for the No. 4 mold, the No. 3 molded product is completely cold-extruded in the main mold;

[0012] (6) The finished product of mold No. 4 is translated to the opening of mold No. 5, and an iron core is punched at the bottom of the central blind hole of the mold No. 4 to form a mold No. 5;

[0013] (7) The molded product No. 5 is translated to the mold opening No. 6, and the rear end of the molded product No. 5 is subjected to mold clamping and punching to form the first truncated cone, the main cylindrical section and the central through hole, and the anti-slip teeth on the end surface of the first truncated cone to form the toothed connecting inner tube;

[0014] The main mold of the No. 6 mold is a three-piece mold along the circumferential direction, a compression spring is arranged between two adjacent 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 cylindrical section corresponding to the outer shape of the main cylindrical section, a top pipe is arranged at the bottom of the main mold, and the end face of the top pipe is arranged to form the shape of the anti-slip teeth; the No. 6 mold is provided with a core rod, the core rod passes through the top pipe and the center through hole of the No. 5 molded product and is inserted into the center hole of the front mold, and cold extrusion is performed under the condition of the core rod protecting the hole.

[0015] Furthermore, the anti-slip teeth are radial teeth arranged radially.

[0016] The invention can use a six-station cold extrusion manufacturing method to continuously cold-extrusion-form the inner tube with a toothed connection for an automobile transmission system through a reasonable arrangement of workstation tasks, thereby improving the mechanical properties of the product and ensuring product quality. Compared with the original process, the invention saves a large amount of lathe processing, saves materials, reduces costs, has stable dimensions, and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the process flow of the manufacturing method of the present invention.

[0018] Figure 2 A front end plan view of a toothed connection inner tube for an automobile transmission system manufactured by the present invention.

[0019] Figure 3 This is a cross-sectional diagram of mold No. 6.

[0020] Figure 4 This is a schematic diagram of one of the three pieces of mold No. 6. DETAILED DESCRIPTION

[0021] Referring to the accompanying drawings, the main body of the outer structure of the inner tube of the belt connection for the automobile transmission system manufactured by the present invention is a rotating body structure with an I-shaped longitudinal section, and the rotating body structure includes a main cylindrical section 63 and a first truncated cone 61 and a second truncated cone 62 respectively arranged at both ends of the main cylindrical section, wherein the diameter of the second truncated cone 62 is slightly larger than the diameter of the first truncated cone 61, a central through hole 64 is arranged at the center of the rotating body structure, and a plurality of anti-slip teeth 65 are arranged on the end surface of the first truncated cone 61; wherein the diameter of the first truncated cone 61 is 135-145% of the diameter of the main cylindrical section, the diameter of the second truncated cone 62 is 150-160% of the diameter of the main cylindrical section, the diameter of the central through hole 64 is 50-60% of the diameter of the main cylindrical section 63, the first truncated cone 61 is thinner than the second truncated cone 62, the height of the second truncated cone 62 is 35-45% of the length of the main cylindrical section 63, and the height of the first truncated cone 61 is 20-30% of the length of the main cylindrical section 63.

[0022] The six-station cold extrusion manufacturing method uses a round disc material to firstly heat treat and spheroidize, then perform a phosphate surface treatment, fine drawing and sizing treatment, and then perform the following steps of cold extrusion manufacturing:

[0023] (1) Feeding the disc into a cold heading machine and automatically cutting it into a single raw material piece 101 for the inner tube with a toothed connection for the automobile transmission system, wherein the diameter of the disc is close to the diameter of the main cylindrical section 63, and the length of the raw material piece 101 is longer than the length of the inner tube with a toothed connection 100;

[0024] (2) The raw material 101 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 diameter of the No. 1 molded product 1 is consistent with the diameter of the main cylindrical section 63, and the rear end is formed with a fillet 11 and a first center positioning hole 12;

[0025] (3) The molded product 1 is translated to the mouth of the mold No. 2, and is cold-forged in the mold No. 2 to pre-forge the large head of the molded product 1. The amount of metal required to form the second truncated cone 62 is basically derived from the large head 21 of the molded product 2 formed by the pre-forging large head, which can reduce the distance of metal flow. The diameter of the cylindrical section 22 at the rear of the large head 21 of the molded product No. 2 is consistent with the diameter of the molded product 1; the diameter of the large head 21 of the molded product No. 2 is between the diameters of the first truncated cone 61 and the second truncated cone 62. The big head 21 of the finished product 2 is a three-section structure, with a cylindrical shape 212 in the middle, a truncated cone 211 at the front end, a positioning hole 23 formed on the top of the truncated cone, the height of the truncated cone 211 is lower than the height of the middle cylindrical shape 212, and the rear end is a curved transition section 213 that transitions with the cylindrical section 22 of the second molded product. The mold surface line of the second mold is located in the middle of the middle cylindrical shape 212. The big head 21 pre-upset in this shape can help to form a hollow truncated cone with a large diameter step difference and thickness, making the metal flow smoother. The positioning hole 24 is still retained on the rear end face of the second molded product 2.

[0026] (4) The second molded product 2 is translated to the mouth of the third mold. The large end of the second molded product 2 is roughened and upset in the third mold to form a front shape 31 of the second truncated cone 62. The diameter of the front shape is consistent with the diameter of the second truncated cone 62, and the height is slightly lower than the height of the second truncated cone 62. In addition, a second center positioning hole 32 is upset at the front end. The amount of metal required to increase the height of the front shape 31 to the height of the second truncated cone is derived from the amount of metal transferred by digging the hole in the front shape. For the third mold, the second molded product 2 is completely in the main mold ( Figure 1 The front and rear parts of the No. 3 molded product 3 are cylindrical sections 33, whose diameter is kept consistent with that of the No. 1 molded product 1, and the rear end surface of the cylindrical section 33 still retains the positioning hole 34. During the cold extrusion of the No. 3 mold, the cylindrical section 22 of the No. 2 molded product remains basically unchanged, that is, the cylindrical section 33 is basically the same as the cylindrical section 22.

[0027] (5) The molded product 3 is translated to the mouth of the mold No. 4, and is cold-forged in the mold No. 4. For the large end of the molded product 3, a center blind hole 41 is cold-extruded on the basis of the second center positioning hole 32 to form the second truncated cone 63. The thickness of the hole bottom 44 of the center blind hole 41 meets the requirements for punching the iron core. The amount of metal transfer generated by digging the center blind hole in the cylindrical section 33 of the molded product 3 is used to extend the length of the cylindrical section 33 to form the cylindrical section 43 of the molded product No. 4, whose diameter is consistent with the diameter of the main cylindrical section 63; the diameter of the center blind hole 41 is consistent with the diameter of the center through hole 64; for the mold No. 4, the molded product 3 is completely cold-extruded in the main mold; the positioning hole 45 from the iron core is forged at the rear end face of the hole bottom 44.

[0028] (6) The molded product 4 is translated to the opening of the mold 5, and the iron core 200 is punched into the bottom of the central blind hole 44 of the molded product 4 to form the molded product 5.

[0029] (7) The molded product 5 is translated to the mold opening of the sixth mold, and the rear end of the molded product 5 is subjected to mold clamping and punching to form the first truncated cone 61, the main cylindrical section 62, the central through hole 64, and the anti-slip teeth 65 on the end surface of the first truncated cone 61, so as to form the toothed connecting inner tube 100; in this embodiment, the anti-slip teeth 65 are radially arranged radial teeth.

[0030] The main mold of the sixth mold is a three-piece mold 301, and a compression spring is set between two adjacent single-piece molds 308. The three-piece mold 301 is composed of three single-piece molds 308 along the circumferential direction. The reference numeral 302 is a hole for setting the compression spring. The mold core 303 of the main mold is an inverted cone. The outer circumferential surface of the three-piece mold 301 is an inverted cone matching the inverted cone of the mold core, so that the three-piece mold 301 can be extended and lowered under the action of the inverted cone guide and the compression spring, and the mold is closed and demolded; the three-piece mold 301 has a corresponding main cylindrical section 6 3, a cylindrical section 304 protruding inwardly in the shape of the main mold is provided with a top pipe 305 at the bottom of the main mold, and the end face of the top pipe 305 is provided with the shape of the anti-slip tooth 65; the sixth mold is provided with a core rod 306, and the core rod 306 passes through the top pipe 305 and the center through hole 51 formed after the fifth molded product 5 is punched with the iron core and is inserted into the center hole of the front mold 307. Cold extrusion is performed under the condition that the core rod 306 protects the hole, which is helpful to simultaneously form the end face teeth and the first hollow truncated cone with a large diameter difference and accurately form the shape of the hole.

[0031] 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 the field of the present invention are included in the protection scope of the present invention.

Claims

1. A six-station cold extrusion manufacturing method for a toothed inner tube for an automobile transmission system, characterized in that The main body of the outer structure of the inner tube connected with the gear for the automobile transmission system is a rotating body structure with an I-shaped longitudinal section, and the rotating body structure includes a main cylindrical section and a first truncated cone and a second truncated cone respectively arranged at both ends of the main cylindrical section, wherein the diameter of the second truncated cone is slightly larger than the diameter of the first truncated cone, a central through hole is arranged at the center of the rotating body structure, and a plurality of anti-slip teeth are arranged on the end surface of the first truncated cone; wherein the diameter of the first truncated cone is 135-145% of the diameter of the main cylindrical section, the diameter of the second truncated cone is 150-160% of the diameter of the main cylindrical section, the diameter of the central through hole is 50-60% of the diameter of the main cylindrical section, the first truncated cone is thinner than the second truncated cone, the height of the second truncated cone is 35-45% of the length of the main cylindrical section, and the height of the first truncated cone is 20-30% of the length of the main cylindrical section; The manufacturing method comprises the following steps: (1) Feeding the disc round material into a cold heading machine and automatically shearing it into a single raw material piece of the inner tube with a toothed connection for the automobile transmission system, wherein the diameter of the disc round material is close to the diameter of the main cylindrical section, and the length of the raw material piece is longer than the length of the inner tube with a toothed connection; (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 diameter of the No. 1 molded product is consistent with the diameter of the main cylindrical section, and the rear end is rounded and the first center positioning hole is formed; (3) The molded product No. 1 is translated to the mouth of the mold No. 2, and the molded product No. 1 is pre-upset. The amount of metal required for forming the second truncated cone is basically derived from the large head of the molded product No. 2 formed by the pre-upset large head. The diameter of the cylindrical section at the rear of the large head of the molded product No. 2 is consistent with the diameter of the molded product No. 1; the diameter of the large head of the molded product No. 2 is between the diameters of the first truncated cone and the second truncated cone. The large head of the molded product No. 2 is a three-section structure, with a cylindrical middle and a truncated cone at the front end. A positioning hole is upset at the top of the truncated cone. The height of the truncated cone is lower than the height of the middle cylinder. The rear end is a curved transition section that transitions with the cylindrical section of the molded product No. 2, and the die surface line of the mold No. 2 is located in the middle of the middle cylinder. (4) The molded product No. 2 is translated to the opening of the mold No. 3, and the large end of the molded product No. 2 is roughened and upset in the mold No. 3 to form the front shape of the second truncated cone, the diameter of the front shape is consistent with the diameter of the second truncated cone, and the height is slightly lower than the height of the second truncated cone, and a second center positioning hole is upset at the front end to obtain the molded product No. 3; the amount of metal required to increase the height of the front shape to the height of the second truncated cone is derived from the amount of metal transferred by digging the hole in the front shape. For the mold No. 3, the molded product No. 2 is completely cold extruded in the main mold; (5) The finished product of the No. 3 mold is translated to the mouth of the No. 4 mold, and is cold-forged in the No. 4 mold. For the large end of the No. 3 molded product, a center blind hole is cold-extruded on the basis of the second center positioning hole to form the second truncated cone. The bottom thickness of the center blind hole meets the requirements of punching the iron core. The amount of metal transfer generated by digging the center blind hole in the cylindrical section of the No. 3 molded product is used to extend the length of the cylindrical section to form the cylindrical section of the No. 4 molded product, whose diameter is consistent with the diameter of the main cylindrical section; the diameter of the center blind hole is consistent with the diameter of the center through hole; for the No. 4 mold, the No. 3 molded product is completely cold-extruded in the main mold; (6) The finished product of mold No. 4 is translated to the opening of mold No. 5, and an iron core is punched at the bottom of the central blind hole of the finished product of mold No. 4 to form the finished product of mold No. 5; (7) The molded product No. 5 is translated to the mold opening No. 6, and the rear end of the molded product No. 5 is subjected to mold clamping and punching to form the first truncated cone, the main cylindrical section and the central through hole, and the anti-slip teeth on the end surface of the first truncated cone to form the toothed connecting inner tube; The main mold of mold No. 6 is a three-piece mold along the circumferential direction, a compression spring is arranged between two adjacent 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 cylindrical section corresponding to the outer shape of the main cylindrical section, a top pipe is arranged at the bottom of the main mold, and the end face of the top pipe is arranged to form the shape of the anti-slip teeth; mold No. 6 is provided with a core rod, the core rod passes through the top pipe and the center through hole of the molded product of No. 5 and is inserted into the center hole of the front mold, and cold extrusion is performed under the condition that the core rod protects the hole.

2. The six-station cold extrusion manufacturing method for the inner tube with a toothed connection for an automobile transmission system as claimed in claim 1, characterized in that The anti-slip teeth are radial teeth arranged radially.

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