A cold heading process and die for standard gear parts

Abstract

The present application relates to a cold heading process and die for a standard gear part, and to the field of gear blank processing, including the following steps: S1: cutting the wire according to the size and transferring it to die No. 1; S2: the punching rod makes the workpiece concave, the lower die cavity makes the workpiece convex, and transfers the workpiece to the predetermined position of die No. 2; S3: the punching rod makes the workpiece convex, the lower die cavity makes the workpiece convex, and the workpiece is thickened, and the workpiece is transferred to the predetermined position of die No. 3; S4: the punching rod flattens the upper ball die, the lower die cavity flattens the lower ball die, the punching rod pre-draws the workpiece, the ejector rod pre-draws the workpiece, and the workpiece is rotated 180° and then transferred to the predetermined position of die No. 4; S5: the ejector rod draws the second hole of the workpiece, and the workpiece is rotated 180° and then transferred to the predetermined position of die No. 5; S6: the ejector rod passes the waste into the waste punching pipe to form a through hole. The present application adopts the cold heading process instead of cutting processing to realize automated production with high production efficiency.

Description

Technical Field

[0001] The present application relates to the field of gear blank processing, and in particular to a cold heading processing technology and a mold for a gear standard part. Background Art

[0002] Standard gears refer to gears whose parameters meet standard values. Standard gears for different purposes are manufactured according to different standards. Standard gears are often used as reference samples for measuring gears, for producing gears, or for calibrating measuring instruments. Gear blanks refer to the blanks used to make gear transmission components such as gears and transmission shafts during the machining process.

[0003] Gear blanks are usually made of metal materials and have a certain size, shape and number of teeth, but they have not been processed carefully and accurately, and need further processing before they can be used to produce mechanical transmission parts. In the related technology, the gear blank is processed by cold heading solid rough blank + machining. The gear blank adopts three processing steps: cold heading solid rough blank, machining, and CNC finishing.

[0004] With respect to the above-mentioned related technologies, the inventors believe that this process has low production efficiency, requires multiple processing steps, and has high labor costs. Summary of the invention

[0005] In order to improve the production efficiency of gear blanks, the present application provides a cold heading process and a mold for gear standard parts.

[0006] In the first aspect, the present application provides a cold heading process for a gear standard part, which adopts the following technical solution:

[0007] A cold heading process for a gear standard part comprises the following steps:

[0008] S1: pull in the wire, cut it according to size, and transfer it to the predetermined position of the No. 1 mold. At this time, the workpiece is a cylindrical shear, and the length of the workpiece is 35.6mm and the diameter is 29.2mm;

[0009] S2: The punch unit moves as a whole, the punch pushes the workpiece into the lower die cavity, the punch makes the workpiece concave, and the lower die cavity makes the workpiece convex. After the operation is completed, the punch unit retreats and resets, the workpiece is pushed out by the ejector, and the clamp mechanism of the cold heading machine automatically clamps the workpiece and transfers the workpiece to the predetermined position of the second die. At this time, the two ends of the workpiece have an inner concave surface and an outer convex surface respectively, and the overall length of the workpiece is 36.3mm and the diameter is 29.6mm;

[0010] S3: The punch unit moves as a whole, the punch pushes the workpiece into the lower die cavity, the punch bulges the workpiece, the lower die cavity bulges the workpiece, and the workpiece is thickened. After the operation is completed, the punch unit retreats and resets, the workpiece is pushed out by the ejector, the clamp mechanism of the cold heading machine automatically clamps the workpiece, and the workpiece is transferred to the predetermined position of the third die. At this time, the diameter of the workpiece increases and the thickness decreases. The two ends of the workpiece have an upper ball die and a lower ball die respectively, and the overall length of the workpiece is 18mm and the diameter is 46mm;

[0011] S4: The punch unit moves as a whole, the punch pushes the workpiece into the lower die cavity, the punch flattens the upper ball die, the lower die cavity flattens the lower ball die, the punch makes a pre-hole on the workpiece, and the ejector makes a pre-hole on the workpiece. After the operation is completed, the punch unit retreats and resets, the ejector pushes the workpiece out, and the clamp mechanism of the cold heading machine automatically clamps the workpiece, rotates the workpiece 180°, and then transfers it to the predetermined position of the fourth die. At this time, the two ends of the workpiece have a first hole and a second hole, respectively, and the length of the workpiece is 15 mm, the diameter is 46.1 mm, the depth of the first hole is 3.5 mm, and the depth of the second hole is 3 mm;

[0012] S5: The punch unit moves as a whole, the punch pushes the workpiece into the lower die cavity, and the ejector pulls the second hole of the workpiece. After the operation is completed, the punch unit retreats and resets, and the ejector pushes the workpiece out. The clamp mechanism of the cold heading machine automatically clamps the workpiece, rotates the workpiece 180°, and then transfers it to the predetermined position of the fifth die. At this time, the two end faces of the workpiece have the first and third holes, respectively, and the length of the workpiece is 15.3 mm, the diameter is 46.2 mm, and the depth of the third hole is 5.5 mm.

[0013] S6: The punch unit moves as a whole, the waste punching tube pushes the workpiece into the lower die cavity, and the ejector rod passes the waste into the waste punching tube. After the operation is completed, the punch unit retreats and resets, and the workpiece is pushed out by the punch sleeve. At this time, the first pulling hole and the third pulling hole of the workpiece are connected to form a through hole, and the length of the workpiece is 15.2mm, the diameter is 46.4mm, and the diameter of the through hole is 14mm.

[0014] By adopting the above technical solution, cold heading process is used instead of cutting process to realize automated production with high production efficiency. Cold heading utilizes the plastic deformation of metal to form the desired shape with high material utilization rate. Cold heading is a precision forming technology with relatively high surface roughness and dimensional accuracy. The cold working hardening of the metal after cold extrusion and the formation of a reasonable fiber streamline distribution inside the part make the strength of the part much higher than that of the raw material.

[0015] Optionally, in S4, the punch rod and the ejector rod process the outer edge of the workpiece and form a chamfer, and the angle between the chamfered surface and the circumferential surface of the workpiece is 65°.

[0016] By adopting the above technical solution, in this step, the chamfering setting is completed at the same time, which can save the subsequent step of separate chamfering processing.

[0017] Optionally, in S5, the punch processes the end surface of the workpiece and forms a marking surface.

[0018] By adopting the above technical solution, in this step, the setting of the marking surface is completed at the same time, which can save the subsequent step of processing the marking surface separately, thereby saving costs in the next processing step.

[0019] Optionally, in S3, the angles of the upper ball mold and the lower ball mold are both 155°.

[0020] By adopting the above technical solution, at this angle, after the upper ball mold and the lower ball mold are flattened, the length of the workpiece is within the required range.

[0021] Optionally, in S5, the push rod processes the end face of the workpiece so that the end face of the workpiece forms a first concave surface that is concave inward, and the angle of the first concave surface is 1°~1.5°.

[0022] By adopting the above technical solution, the contact surface between the end of the push rod and the end face of the workpiece can be increased, so that the force applied to the push rod during extrusion is dispersed, thereby increasing the service life of the push rod.

[0023] Optionally, in S6, the punch sleeve processes the end face of the workpiece so that the end face of the workpiece forms a second concave surface that is concave inward, and the angle of the second concave surface is 0.5°~1°.

[0024] By adopting the above technical solution, the contact surface between the end of the punch sleeve and the end face of the workpiece can be increased, so that the force of the punch sleeve is dispersed during extrusion, thereby increasing the service life of the punch sleeve.

[0025] In the second aspect, the present application provides a cold heading processing mold for gear standard parts, adopting the following technical scheme: including mold No. 1, mold No. 2, mold No. 3, mold No. 4, and mold No. 5, and the mold No. 1, mold No. 2, mold No. 3, mold No. 4, and mold No. 5 are all composed of a die unit and a main die unit; the die units of the mold No. 1, mold No. 2, mold No. 3, and mold No. 4 all include a back-punching pad, a punch rod, and an upper die, and the main die units of the mold No. 1, mold No. 2, mold No. 3, and mold No. 4 all include a lower die, a push rod, a die sleeve, and a T-shaped pad; the die unit of the mold No. 5 includes a back-punching pad, a waste punching tube, and an upper die, and the main die unit of the mold No. 5 includes a lower die, a push rod, a punch sleeve, a die sleeve, and a T-shaped pad.

[0026] By adopting the above technical scheme, the setting of the upper die is convenient for installing the punch pad and the punch rod, and the punch rods at different stations can process the workpiece with different processes. The setting of the lower die is convenient for installing the ejector rod, punch sleeve, die sleeve and T-type pad, and the lower die cavity at different stations can process the workpiece with different processes.

[0027] Optionally, a first pull block is provided at the end of the punch rod of the third die, and a second pull block is provided at the end of the top rod of the third die, and the size of the first pull block is greater than that of the second pull block.

[0028] By adopting the above technical solution, the first pulling block facilitates the forming of the first pulling hole, the second pulling block facilitates the forming of the second pulling hole, and the depth of the first pulling hole is greater than the depth of the second pulling hole.

[0029] Optionally, a third pull block is provided at the end of the punch rod of the fourth die, and a fourth pull block is provided at the end of the top rod of the fourth die. The size of the fourth pull block is the same as that of the first pull block, and the size of the third pull block is larger than that of the fourth pull block.

[0030] By adopting the above technical solution, the third pulling block forms the second pulling hole into the third pulling hole.

[0031] Optionally, the waste punching pipe of the No. 5 mold is hollow, an upper waste port for waste discharge is provided in the middle of the waste punching pipe, a lower waste port cooperating with the upper waste port is provided in the upper mold of the No. 5 mold, and the top rod of the No. 5 mold is slidably matched with the middle of the waste punching pipe.

[0032] By adopting the above technical solution, in the No. 5 mold, the ejector rod can push the waste in the workpiece into the waste punching pipe, and drop it out along the upper waste port and the lower waste port, which is convenient for the discharge of the waste. Then the punch sleeve can push the workpiece in the lower mold cavity.

[0033] In summary, the present application includes at least one of the following beneficial technical effects:

[0034] 1. Use cold heading process instead of cutting process to realize automated production with high production efficiency. Cold heading is to use the plastic deformation of metal to make the required shape with high material utilization rate. Cold heading is a precision forming technology with high surface roughness and dimensional accuracy. The cold working hardening of metal after cold extrusion and the formation of reasonable fiber streamline distribution inside the parts make the strength of the parts much higher than that of the raw materials.

[0035] 2. The first concave surface can increase the contact surface between the end of the ejector rod and the end surface of the workpiece, so that the force of the ejector rod is dispersed when it is extruded, thereby increasing the service life of the ejector rod;

[0036] 3. The second concave surface can increase the contact area between the end of the punch sleeve and the end face of the workpiece, so that the force of the punch sleeve is dispersed during extrusion, thereby increasing the service life of the punch sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the cold heading process of standard gear parts and the cutting of the die;

[0038] Figure 2 It is the cross-sectional view of the cold heading process and die No. 1 of the gear standard parts;

[0039] Figure 3 It is a schematic diagram of the cold heading process of the gear standard part and the workpiece No. 1 of the die;

[0040] Figure 4 It is the cold heading process of the gear standard parts and the cross-sectional view of the No. 2 die of the die;

[0041] Figure 5 It is a schematic diagram of the cold heading process of the gear standard part and the second workpiece of the die;

[0042] Figure 6 It is the cold heading process of the gear standard parts and the cross-sectional view of the No. 3 die;

[0043] Figure 7 It is the cross-sectional view of the cold heading process of the gear standard part and the workpiece No. 3 of the die;

[0044] Figure 8 It is the cold heading process of the gear standard parts and the cross-sectional view of the No. 4 die of the die;

[0045] Fig. 9 It is the cross-sectional view of the cold heading process of the gear standard part and the die workpiece No. 4;

[0046] Fig.10 It is the cold heading process of the gear standard parts and the cross-sectional view of the No. 5 die;

[0047] Fig.11 It is a cross-sectional view of the cold heading process of the gear standard part and the mold workpiece No. 5.

[0048] Description of reference numerals: 1, mold No. 1; 2, mold No. 2; 3, mold No. 3; 4, mold No. 4; 5, mold No. 5; 6, workpiece; 601, upper ball mold; 602, lower ball mold; 603, first pulling hole; 604, second pulling hole; 605, third pulling hole; 606, inner concave surface; 607, outer convex surface; 608, marking surface; 609, chamfer; 610, first concave surface; 611, second concave surface; 612, through hole; 11. Punch die unit; 110. Back-punch pad; 111. Punch rod; 1110. First pull block; 1111. Third pull block; 112. Upper die; 12. Main die unit; 120. Lower die; 121. Push rod; 1210. Second pull block; 1211. Fourth pull block; 122. Die sleeve; 123. T-shaped pad; 124. Punch-off waste pipe; 1240. Upper waste port; 1241. Lower waste port; 125. Punch sleeve. DETAILED DESCRIPTION

[0049] The following is combined with Figures 1 to 11This application is described in further detail.

[0050] The present application embodiment discloses a cold heading process for a gear standard part. Figure 1 The cold heading process of gear standard parts includes the following steps:

[0051] S1: The wire wheel mechanism pulls in the wire, passes through the wire die, and holds the wire against the top of the mountain to position it. The cutting mechanism is activated to cut the wire according to size. The conveying mechanism clamps the cut material and conveys it to the predetermined position of the No. 1 die. At this time, the workpiece 6 is a cylindrical cut material, and the length of the workpiece 6 is 35.6mm, the diameter is 29.2mm, and the mass is 187g.

[0052] It should be noted that the wire wheel mechanism, the backrest, the cutting mechanism and the transmission mechanism are all internal structures of the cold heading machine, and the cold heading machine is the existing technology.

[0053] S2: Reference Figure 2 and Figure 3 , the two end surfaces of the workpiece 6 are respectively concave and convex, the punch unit 11 moves as a whole, the punch rod 111 pushes the workpiece 6 into the cavity of the lower die 120, the main die unit 12 is fixed on the cold heading machine, the punch rod 111 concave the workpiece 6, and the cavity of the lower die 120 convexes the workpiece 6, after the operation is completed, the punch unit 11 retreats and resets, the workpiece 6 is pushed out by the push rod 121, the clamping mechanism of the cold heading machine automatically clamps the workpiece 6, and transfers the workpiece 6 to the predetermined position of the second die 2, at this time, the two ends of the workpiece 6 have an inner concave surface 606 and an outer convex surface 607 respectively, and the overall length of the workpiece 6 is 36.3mm, the diameter is 29.6mm, the outer convex surface 607 is truncated cone-shaped, the upper bottom surface diameter of the outer convex surface 607 is 21mm, and the angle of the outer convex surface 607 is 150°.

[0054] It should be noted that the angle of the inner concave surface 606 is 150°~170°. The setting of the inner concave surface 606 can increase the contact area between the end of the punch rod 111 and the end face of the workpiece 6, so that the force of the punch rod 111 is dispersed during extrusion, so as to increase the service life of the punch rod 111, and the setting of the outer convex surface 607 facilitates the formation of the lower ball mold 602 in the next step.

[0055] S3: Reference Figure 4 and Figure 5The punch unit 11 moves as a whole, the punch rod 111 pushes the workpiece 6 into the cavity of the lower die 120, the punch rod 111 bulges the workpiece 6 and thickens the workpiece 6, the main die unit 12 is fixed on the cold heading machine, after the operation is completed, the punch unit 11 retreats and resets, the push rod 121 pushes the workpiece 6 out, the clamp mechanism of the cold heading machine automatically clamps the workpiece 6, and transfers the workpiece 6 to the predetermined position of the third die 3, at this time, the diameter of the workpiece 6 increases, the thickness decreases, and the two end surfaces of the workpiece 6 have upper ball The upper ball mold 601 and the lower ball mold 602 have an overall length of 18 mm and a diameter of 46 mm, a diameter error of within 0.05 mm, a length of the workpiece 6 minus the length of the upper ball mold 601 and the lower ball mold 602 is 12.5 mm, the upper ball mold 601 and the lower ball mold 602 are both truncated cone-shaped, the diameter of the upper bottom surface of the upper ball mold 601 is 21.5 mm, the diameter of the lower bottom surface of the lower ball mold 602 is 21 mm, and the angles of the upper ball mold 601 and the lower ball mold 602 are both 155°.

[0056] It should be noted that the setting of the upper ball mold 601 and the lower ball mold 602 is to prepare for the next step of pressing the two ends of the workpiece 6 into a flat surface, and the setting of the upper ball mold 601 and the lower ball mold 602 can also increase the contact area between the workpiece 6 and the punch rod 111 and the cavity of the lower mold 120 respectively, so that the force of the punch rod 111 is dispersed during extrusion, thereby increasing the service life of the punch rod 111.

[0057] S4: Reference Figure 6 and Figure 7 The punch unit 11 moves as a whole, the punch rod 111 pushes the workpiece 6 into the cavity of the lower die 120, the punch rod 111 flattens the upper ball die 601, and the cavity of the lower die 120 flattens the lower ball die 602. The punch rod 111 pre-pull holes on the workpiece 6, the main die unit 12 is fixed on the cold heading machine, the top rod 121 pre-pull holes on the workpiece 6, the punch rod 111 and the top rod 121 process the outer edge of the workpiece 6 and form a chamfer 609. After the operation is completed, the punch unit 11 retreats and resets, and the top rod 121 pushes the workpiece 6 out, and the clamp of the cold heading machine The structure automatically clamps the workpiece 6, rotates the workpiece 6 180° and then transmits it to the predetermined position of the No. 4 mold 4. At this time, the two end faces of the workpiece 6 respectively have a first pulling hole 603 and a second pulling hole 604, and the length of the workpiece 6 is 15 mm, the diameter is 46.1 mm, the diameter error is within 0.05 mm, the plane diameter of the workpiece 6 minus the chamfer 609 is 42.4 mm, the depth of the first pulling hole 603 is 3.5 mm, the depth of the second pulling hole 604 is 3 mm, and the angle between the chamfer 609 surface and the circumferential surface of the workpiece 6 is 65°.

[0058] It should be noted that in this step, the upper ball mold 601 and the lower ball mold 602 are flattened to make the two ends of the workpiece 6 flat, and the length of the workpiece 6 is controlled within a specified range, so that the length of the workpiece 6 can also be controlled within the specified range during subsequent punching. In this step, the setting of the chamfer 609 is completed at the same time, which can save the subsequent step of separately processing the chamfer 609.

[0059] S5: Reference Figure 8 and Fig. 9 The punch unit 11 moves as a whole, the punch rod 111 pushes the workpiece 6 into the cavity of the lower die 120, the punch rod 111 processes the end face of the workpiece 6 and forms a marking surface 608, the push rod 121 processes the end face of the workpiece 6 to form a first concave surface 610 concave inwardly on the end face of the workpiece 6, the push rod 121 pulls the second pulling hole 604 of the workpiece 6 to form a third pulling hole 605, the main die unit 12 is fixed on the cold heading machine, and after the operation is completed, the punch unit 11 retreats and resets, the push rod 121 pushes the workpiece 6 out, and the clamp mechanism of the cold heading machine automatically The workpiece 6 is clamped dynamically, rotated 180° and then transferred to the predetermined position of the No. 5 mold 5. At this time, the two end surfaces of the workpiece 6 respectively have a first pulling hole 603 and a third pulling hole 605, and the length of the workpiece 6 is 15.3 mm, the diameter is 46.2 mm, the diameter error is within 0.05 mm, the plane diameter of the workpiece 6 minus the chamfer 609 is 42.4 mm, the depth of the third pulling hole 605 is 5.5 mm, the angle between the chamfer 609 surface and the circumferential surface of the workpiece 6 is 65°, and the angle of the first recessed surface 610 is 1°~1.5°.

[0060] It should be noted that the setting of the first recessed surface 610 can increase the contact area between the end of the push rod 121 and the end face of the workpiece 6, so that the force of the push rod 121 is dispersed when it is extruded, so as to increase the service life of the push rod 121. In this step, the second pulling hole 604 can be pulled to form a third pulling hole 605 with a deeper depth. In order to prepare for the subsequent through hole 612, the setting of the marking surface 608 is convenient for distinguishing the front and back sides when the tooth shape of the workpiece 6 is subsequently processed. In this step, the setting of the marking surface 608 is completed together, which can save the subsequent step of separately processing the marking surface 608, thereby saving expenses in the next processing step.

[0061] S6: Reference Fig.10 and Fig.11The punch unit 11 moves as a whole, the waste punching tube 124 pushes the workpiece 6 into the cavity of the lower die 120, the main die unit 12 is fixed on the cold heading machine, the punch sleeve 125 processes the end face of the workpiece 6, so that the end face of the workpiece 6 forms a second recessed surface 611 recessed inwardly, and the ejector rod 121 passes the waste into the waste punching tube 124. After the operation is completed, the punch unit 11 retreats and resets, and the workpiece 6 is pushed out by the punch sleeve 125. At this time, the first pulling hole 603 and the third pulling hole 605 of the workpiece 6 are connected to form a through hole 612, and the length of the workpiece 6 is 15.1~15.4mm, the diameter is 46.2~46.4mm, the diameter of the through hole 612 is 14~14.1mm, and the angle of the second recessed surface 611 is 0.5°~1°.

[0062] It should be noted that the provision of the second recessed surface 611 can increase the contact surface between the end of the punch sleeve 125 and the end surface of the workpiece 6 , so that the force of the punch sleeve 125 is dispersed during extrusion, thereby increasing the service life of the punch sleeve 125 .

[0063] The embodiment of the present application also discloses a cold heading processing mold for gear standard parts, including mold No. 1 1, mold No. 2 2, mold No. 3 3, mold No. 4 4, and mold No. 5 5. The mold No. 1 1, mold No. 2 2, mold No. 3 3, mold No. 4 4, and mold No. 5 are respectively installed at different positions on the cold heading machine. The mold No. 1 1, mold No. 2 2, mold No. 3 3, mold No. 4 4, and mold No. 5 are all composed of a die unit 11 and a main die unit 12. The die unit 11 is installed at the moving end of the cold heading machine, and the main die unit 12 is installed at the fixed end of the cold heading machine.

[0064] The die units 11 of die No. 1, die No. 2, die No. 3, and die No. 4 all include a back-punching pad 110, a punch rod 111, and an upper die 112. The upper die 112 is fixedly installed on the moving end of the cold heading machine. The upper die 112 is hollow. The back-punching pad 110 and the punch rod 111 both penetrate and extend into the upper die 112. The back-punching pad 110 and the punch rod 111 are both fixedly connected to the upper die 112. The punch rod 111 is located at the front end of the back-punching pad 110, and the end of the punch rod 111 away from the back-punching pad 110 extends out of the upper die 112, so as to facilitate corresponding processing of the workpiece 6.

[0065] The main die units 12 of the No. 1 die 1, the No. 2 die 2, the No. 3 die 3, and the No. 4 die 4 all include a lower die 120, a push rod 121, a die sleeve 122, and a T-shaped pad 123. The lower die 120 is fixedly installed at the fixed end of the cold heading machine. The front end of the lower die 120 is a die cavity, and the rear end of the lower die 120 is a hollow setting. The die sleeve 122 is fixed to the rear end of the lower die 120, and the die sleeve 122 is also a hollow setting. The push rod 121 is slidably connected to the rear end of the lower die 120, and the T-shaped pad 123 is slidably connected in the die sleeve 122. The push rod 121 and the T-shaped pad 123 are fixedly connected. The push rod 121 is located at the front end of the T-shaped pad 123, and the end of the T-shaped pad 123 away from the push rod 121 is connected to the push rod in the cold heading machine. It should be noted that the push rod in the cold heading machine is the prior art.

[0066] Reference Figure 2 and Figure 3 In the No. 1 die 1, the end of the punch rod 111 away from the punch back pad 110 is convex, and the bottom of the die cavity of the lower die 120 is concave, so that in S1, the two ends of the workpiece 6 can be concave and convex respectively.

[0067] Reference Figure 4 and Figure 5 In the second die 2, the end of the punch rod 111 away from the punch pad 110 is concave, and the bottom of the lower die 120 cavity is concave, so that in S3, the two ends of the workpiece 6 can be convex to form an upper ball mold 601 and a lower ball mold 602, and the length of the lower die 120 cavity is small but the diameter is large, so that the workpiece 6 can be thickened.

[0068] Reference Figure 6 and Figure 7 In the third mold 3, a first pull block 1110 is fixed to the middle of one end of the punch rod 111 away from the punch back pad 110, and a second pull block 1210 is fixed to the middle of one end of the top rod 121 away from the T-shaped pad 123. The size of the first pull block 1110 is larger than that of the second pull block 1210. The first pull block 1110 facilitates the forming of the first pull hole 603, and the second pull block 1210 facilitates the forming of the second pull hole 604. In addition, the surfaces of the first pull block 1110 and the second pull block 1210 are both titanium-plated to improve the hardness, wear resistance and corrosion resistance of the surfaces of the first pull block 1110 and the second pull block 1210.

[0069] Reference Figure 8 and Fig. 9In the fourth mold 4, a third pull block 1111 is fixed to the middle of one end of the punch rod 111 away from the punch back pad 110, and a fourth pull block 1211 is fixed to the middle of one end of the top rod 121 away from the T-shaped pad 123. The size of the fourth pull block 1211 is the same as that of the first pull block 1110, and the size of the third pull block 1111 is larger than that of the fourth pull block 1211. The third pull block 1111 forms the second pull hole 604 into the third pull hole 605. In addition, the surfaces of the third pull block 1111 and the fourth pull block 1211 are both titanium-plated to improve the hardness, wear resistance and corrosion resistance of the surfaces of the third pull block 1111 and the fourth pull block 1211.

[0070] Reference Fig.10 Preferably, the die unit 11 of the fifth die 5 includes a back-punching pad 110, a punching waste pipe 124, and an upper die 112. The upper die 112 is fixedly installed on the moving end of the cold heading machine. The upper die 112 is hollow. The back-punching pad 110 and the punching waste pipe 124 both penetrate and extend into the upper die 112. The back-punching pad 110 and the punching waste pipe 124 are fixedly connected to the upper die 112. The punching waste pipe 124 is located at the front end of the back-punching pad 110. The end of the punching waste pipe 124 away from the punching back pad 110 extends out of the upper mold 112, and the punching waste pipe 124 is hollow. An upper waste port 1240 is opened in the middle of the punching waste pipe 124, and the upper mold 112 is opened with a lower waste port 1241 that cooperates with the upper waste port 1240. The lower waste port 1241 is located below the upper waste port 1240, and the two are connected to each other. The upper waste port 1240 and the lower waste port 1241 are used for waste discharge.

[0071] The main mold unit 12 of the fifth mold 5 includes a lower mold 120, a push rod 121, a punch sleeve 125, a mold sleeve 122, and a T-shaped pad 123. The lower mold 120 is fixedly installed at the fixed end of the cold heading machine. The front end of the lower mold 120 is a mold cavity, and the rear end of the lower mold 120 is a hollow setting. The mold sleeve 122 is fixed to the rear end of the lower mold 120. The mold sleeve 122 is also a hollow setting. The push rod 121 is slidably connected to the rear end of the lower mold 120, and the T-shaped pad 123 is slidably connected in the mold sleeve 122. The rod 121 is fixedly connected to the T-shaped pad 123, the push rod 121 is located at the front end of the T-shaped pad 123, the end of the T-shaped pad 123 away from the push rod 121 is connected to the push rod in the cold heading machine, the push rod 121 is slidably matched with the middle part of the waste punching pipe 124, the punch sleeve 125 is slidably connected between the rear end of the lower die 120 and the die sleeve 122, the punch sleeve 125 is slidably sleeved on the outside of the push rod 121, the punch sleeve 125 and the T-shaped pad 123 are respectively connected to two independent push rods in the cold heading machine.

[0072] In the No. 5 mold 5, the push rod 121 can push the waste in the workpiece 6 into the waste punching pipe 124, and drop it out along the upper waste port 1240 and the lower waste port 1241, which is convenient for the discharge of the waste. Then the punch sleeve 125 can push the workpiece 6 in the mold cavity of the lower mold 120.

[0073] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A cold heading process for standard gear parts, characterized in that: The steps include: S1: pull in the wire, cut it according to the size, and transfer it to the predetermined position of the first die. At this time, the workpiece (6) is a cylindrical shear material, and the length of the workpiece (6) is 35.6 mm and the diameter is 29.2 mm; S2: The punch unit of the No. 1 die moves as a whole, the punch pushes the workpiece (6) into the lower die cavity, the punch makes the workpiece (6) concave, and the lower die cavity makes the workpiece (6) convex. After the operation is completed, the punch unit retreats and resets, the workpiece (6) is pushed out by the ejector, the clamp mechanism of the cold heading machine automatically clamps the workpiece (6), and the workpiece (6) is transferred to the predetermined position of the No. 2 die. At this time, the two ends of the workpiece (6) respectively have an inner concave surface (606) and an outer convex surface (607), and the overall length of the workpiece (6) is 36.3 mm, the diameter is 29.6 mm, the outer convex surface (607) is truncated, the upper bottom surface diameter of the outer convex surface (607) is 21 mm, the angle of the outer convex surface (607) is 150°, and the angle of the inner concave surface (606) is 150°~170°; S3: The punch unit of the second die moves as a whole, the punch pushes the workpiece (6) into the lower die cavity, the punch bulges the workpiece (6), the lower die cavity bulges the workpiece (6), and the workpiece (6) is thickened. After the operation is completed, the punch unit retreats and resets, the workpiece (6) is pushed out by the ejector rod, the clamp mechanism of the cold heading machine automatically clamps the workpiece (6), and the workpiece (6) is transferred to the predetermined position of the third die. At this time, the diameter of the workpiece (6) increases and the thickness decreases. The two ends of the workpiece (6) respectively have an upper ball mold (601) and a lower ball mold (602). The workpiece (6) has an overall length of 18 mm and a diameter of 46 mm, and a diameter error within 0.05 mm. The length of the workpiece (6) minus the length of the upper ball mold (601) and the lower ball mold (602) is 12.5 mm. The upper ball mold (601) and the lower ball mold (602) are both truncated cone-shaped. The diameter of the upper bottom surface of the upper ball mold (601) is 21.5 mm, and the diameter of the lower bottom surface of the lower ball mold (602) is 21 mm. The angles of the upper ball mold (601) and the lower ball mold (602) are both 155°. S4: The punch unit of the third die moves as a whole, the punch pushes the workpiece (6) into the lower die cavity, the punch flattens the upper ball die (601), the lower die cavity flattens the lower ball die (602), the punch pre-pull holes on the workpiece (6), the push rod pre-pull holes on the workpiece (6), after the operation is completed, the punch unit retreats and resets, the push rod pushes the workpiece (6), the clamp mechanism of the cold heading machine automatically clamps the workpiece (6), the workpiece (6) is rotated 180° and then transferred to the predetermined position of the fourth die, at which time the two ends of the workpiece (6) have first pull holes ( 603) and the second broaching hole (604), the length of the workpiece (6) is 15 mm, the diameter is 46.1 mm, the diameter error is within 0.05 mm, the depth of the first broaching hole (603) is 3.5 mm, the depth of the second broaching hole (604) is 3 mm, the plane diameter of the workpiece (6) minus the chamfer (609) is 42.4 mm, the punch rod and the ejector rod process the outer edge of the workpiece (6) and form the chamfer (609), and the angle between the chamfer (609) surface and the circumferential surface of the workpiece (6) is 65°; S5: The punch unit of the fourth die moves as a whole, the punch pushes the workpiece (6) into the lower die cavity, the push rod pulls the second pulling hole (604) of the workpiece (6), and after the operation is completed, the punch unit retreats and resets, the push rod pushes the workpiece (6), and the clamp mechanism of the cold heading machine automatically clamps the workpiece (6), rotates the workpiece (6) 180 degrees, and then transfers it to the predetermined position of the fifth die. At this time, the two end faces of the workpiece (6) respectively have the first pulling hole (603) and the third pulling hole (605), and the length of the workpiece (6) is 15.3 mm, the diameter is 46.2 mm, the diameter error is within 0.05 mm, the depth of the third pulling hole (605) is 5.5 mm, and the push rod processes the end face of the workpiece (6) so that the end face of the workpiece (6) forms a first concave surface (610) that is concave inward, and the angle of the first concave surface (610) is 1°~1.5°; S6: The punch unit of the fifth die moves as a whole, the waste material punching tube pushes the workpiece (6) into the lower die cavity, and the ejector pushes the waste material into the waste material punching tube. After the operation is completed, the punch unit retreats and resets, and the workpiece (6) is pushed out by the punch sleeve. At this time, the first pulling hole (603) and the third pulling hole (605) of the workpiece (6) are connected to form a through hole (612), and the length of the workpiece (6) is 15.2 mm, the diameter is 46.4 mm, and the diameter of the through hole (612) is 14 mm. The punch sleeve processes the end face of the workpiece (6) so that the end face of the workpiece (6) forms a second concave surface (611) that is concave inward, and the angle of the second concave surface (611) is 0.5°~1°; In S5, the punch processes the end surface of the workpiece (6) and forms a marking surface (608).

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