A contact pin part cold extrusion forming process, die and die using method

Abstract

This invention introduces a cold extrusion forming process, mold, and mold usage method for contact pin parts, including: bar blanking → sandblasting → cleaning → first-stage extrusion → deburring → sandblasting → cleaning → second-stage extrusion → machining; forming molds, including a first-stage extrusion mold and a second-stage extrusion mold. This invention, by combining first-stage and second-stage extrusion, achieves a reasonable distribution of material flow between the two stages, which is beneficial for the plastic forming of metal and increases mold life. Since the junction between the waist-shaped column and the T-shaped connecting body is a sharp angle, the two-stage extrusion method changes the metal flow pattern during forging, avoiding material tearing at the sharp angle. The part itself has a complete streamline, good mechanical properties, and ensures the part's electrical conductivity. Secondary forming combined with minimal machining reduces cutting allowance and cutting surface, improves raw material utilization, increases production efficiency, reduces production costs, and enhances market competitiveness.

Description

Technical Field

[0001] This invention relates to the field of metal cold forging forming process and mold technology, and in particular to a cold extrusion forming process, mold and mold usage method for contact pin parts. Background Technology

[0002] Contact pin parts for new energy vehicles are mainly used in DC contactors and are one of the core components of DC contactors; for example Figure 1 As shown, the component structure includes a cuboid connecting end a, a waist-shaped column connecting end b, a connecting end c with an internally threaded hole, four sealing ring grooves d along the contour, and a T-shaped connecting body e. The lower ends of connecting ends a, c, and e are all rounded to the bottom surface. The contour accuracy error of the cuboid connecting end, the waist-shaped column connecting end, and the connecting end with the internally threaded hole must be within ±0.02mm to meet the requirements of good structural strength and good conductivity of the contact pin, enabling it to be used in complex environments such as high temperature, vibration, and frequent opening and closing. Therefore, its design and manufacturing process must simultaneously possess high precision, high stability, and good protective performance.

[0003] Currently, the existing technical solution 1 uses milling, which takes 25 minutes to process a single part, with a material utilization rate of 41.5%. The machining efficiency is low, which is not conducive to cost reduction and cannot meet the needs of large-volume supply. Moreover, the material's flow lines will be broken during the cutting process, which will have a significant impact on the fatigue performance of the part itself. The existing technical solution 2 uses open die forging and edge trimming. This process requires contour milling of the contour that contacts the injection mold to ensure an assembly dimension gap of 0.03-0.04mm, otherwise there will be a risk of glue leakage. The machining part is 50% more than cold extrusion molding, which lengthens the processing time. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cold extrusion forming process, mold, and mold usage method for contact pin parts, thereby improving processing efficiency and ensuring processing accuracy.

[0005] The technical solution adopted in this invention is:

[0006] A cold extrusion forming process for contact pin parts includes: bar blanking → sandblasting → cleaning → first-stage extrusion → deburring → sandblasting → cleaning → second-stage extrusion → machining.

[0007] The first extrusion is a positive extrusion, which forms an intermediate forging billet with a waist-shaped boss from the bar stock; the second extrusion is a composite extrusion, which forms the connecting end a, the waist-shaped column connecting end b, the connecting end c, four sealing ring grooves along the contour, and the T-shaped connecting body.

[0008] The machining includes machining the cuboid of connecting end a, the oblong end face of connecting end b, the end face of connecting end c, the internal threaded hole, and the lower end face of the T-shaped connecting body.

[0009] A cold extrusion forming die for a contact pin part includes a primary extrusion die and a secondary extrusion die;

[0010] The first-order extrusion die includes a first-order upper die assembly, a first-order upper die, a first-order lower die, a lower die floating assembly, and a lower die fixing assembly. Both the first-order upper die and the first-order lower die have a frustum structure. The first-order upper die is tightly fitted at the center of the first-order upper die assembly. The center of the first-order upper die has a waist-shaped through hole that matches the size of the waist-shaped column in the middle of the part. The center of the lower end face has a rectangular funnel-shaped groove around the waist-shaped through hole. The center of the first-order lower die has a rectangular through hole that corresponds to the rectangular funnel-shaped groove of the first-order upper die. The first-order lower die is correspondingly located at the center of the lower die floating assembly, which is mounted on the first-order lower die fixing assembly.

[0011] The two-stage extrusion die includes a two-stage upper die assembly, a punch, a punch mandrel, a two-stage lower die, and a lower die assembly. The punch is located at the center of the two-stage upper die assembly and is a square rod structure. A waist-shaped through hole matching the waist-shaped column in the middle of the part is provided at the center of the punch. A protruding ridge A for forming a sealing ring groove on the upper surface of the T-shaped connection body of the part is provided on the lower end face of the punch. Avoidance grooves extend from both ends of the protruding ridge A to the two sides of the punch mandrel. The punch mandrel is a long rod-shaped structure with a cross-section consistent with the waist-shaped through hole. The punch mandrel is tightly fitted into the waist-shaped through hole at the center of the punch. A space is left between the lower end face of the punch mandrel and the lower end face of the punch to accommodate the part. The gap of the central waist-shaped column; the second-order lower die is set in the center of the lower die assembly, and the upper circumference of the second-order lower die is provided with an installation step. The second-order lower die is a split frustum structure, including a main body and dividing blocks; the middle of the main body is set with a square cavity groove that matches the punch, and the dividing blocks are set opposite to each other at both ends of the cavity groove in the width direction; the outer edge surface of the main body is symmetrically provided with alignment grooves, the bottom of the cavity groove is set with arcs on both sides for the lower arc forming of the part, the bottom of the groove is provided with a boss for the T-shaped connection of the part to the main body forming, and the bottom and side walls of the groove are provided with a protruding ridge B for the forming of the sealing ring groove of the part; the center of the bottom of the groove is provided with an ejector through hole.

[0012] Specifically, the first-order upper mold assembly includes an upper template A, an upper mold pad, an upper mold middle ring, an upper mold outer ring, and guide sleeves; the upper template A is connected to the press movable crossbeam, the upper mold pad and the upper mold middle ring are set inside the upper mold outer ring, the upper mold outer ring is fixed to the lower side of the upper template by bolts, and the guide sleeves are respectively set at the four corners of the lower side of the upper template A; the first-order upper concave mold is tightly fitted inside the upper mold middle ring.

[0013] Specifically, the lower die floating assembly includes a lower die outer ring, a lower die pad, and a floating template; a first-order lower die is tightly fitted inside the lower die outer ring, the lower die pad is located inside the lower die outer ring on the lower side of the first-order lower die, and the lower die outer ring is bolted to the floating template.

[0014] Specifically, the lower mold fixing assembly includes an ejector A, an ejector pad, a fixing flange, an elastic washer I, a steel pad, an elastic washer II, an ejector rod A, an ejector pad A, a lower mold plate A, a nitrogen spring, equal-height bolts, and guide pillars; the fixing flange is set on the lower mold plate A, and the ejector pad A is set inside the center of the lower end of the fixing flange; the ejector rod A is set at the center of the ejector pad A through an upper step and its lower end passes through the lower mold plate A; the ejector pad is set on the ejector pad A, and the ejector A is a rectangular square rod structure. A rectangular through hole is placed on the ejector pad block, with its upper end passing through the floating template and the lower die pad in sequence, located in the center of the lower die. Elastic washer one, steel pad and elastic washer two are set on the steps on the outer edge of the fixed flange from top to bottom. Nitrogen spring is set between the lower template A and the floating template. The equal height bolt passes through the floating template and is tightened on the lower template A. The guide post is set on the lower template A, with the upper end of the guide post passing through the floating template and corresponding to the guide sleeve on the lower side of the upper template. The equal height bolt and the guide post are slidably fitted with the floating template.

[0015] Specifically, the second-order upper mold assembly includes an upper template B, an upper pad, a connecting flange pad, a connecting flange, a punch pad, a punch sleeve, and a lock nut; the upper template B is connected to the press's movable crossbeam, the upper pad is disposed between the upper template B and the connecting flange, the connecting flange is connected to the upper pad and the upper template by bolts, and the lower outer edge of the connecting flange is threaded; the punch sleeve and the connecting flange pad are disposed inside the connecting flange by a lock nut; the punch is tightly fitted inside the center of the punch sleeve, and the punch pad is disposed inside the punch sleeve on the upper side of the punch; the lower end of the punch protrudes from the lower end of the punch sleeve.

[0016] Specifically, the lower mold assembly includes a die middle ring, a die outer ring, a die threaded pressure ring, an ejector B, a mold base, an ejector pad B, a mold base pad, an ejector pin B, a lower template B, an ejector fixing block, a mold cylinder, and a mold cylinder pressure ring; the die middle ring is heat-fitted into the die outer ring, and the second-order lower die is tightly fitted into the upper part of the die middle ring; the die threaded pressure ring is threaded into the lower side of the die middle ring; the upper stepped portion of the mold base is located inside the die threaded pressure ring, and its upper end face contacts the lower end face of the second-order lower die; the mold base is connected by... The mold base plate is set on the lower template B; the ejector pin B is set at the center of the mold base plate and the lower template B; the ejector pad B is set inside the center of the lower end of the mold base; the upper end of the ejector pin B is in contact with the ejector pad B; the ejector B is set on the ejector pad B through the ejector fixing block; the upper end of the ejector B is located in the ejector through hole at the center of the second-order lower die; the mold cylinder is set on the lower template B outside the outer ring of the die through bolts; the mold cylinder pressure ring is set on the upper end of the mold cylinder through bolts and is set on the step of the outer ring of the upper end face of the outer ring of the die.

[0017] Specifically, the inner hole of the die cavity is a tapered hole with a stepped end that matches the frustum structure of the second-order lower die cavity. The inner wall of the die cavity is provided with a semi-circular groove corresponding to the alignment groove on the outer edge of the second-order lower die cavity. The alignment groove and the semi-circular groove together form a pin hole. The semi-circular groove extends upward along the inner wall to the top of the die cavity to form a pin removal hole.

[0018] A method for using a cold extrusion forming die for contact pin parts, the specific steps of which are as follows:

[0019] S1: Assembly of upper mold components in sequence;

[0020] The upper mold middle ring is forcefully pressed into the upper mold outer ring, the first-order upper die is forcefully pressed into the upper mold middle ring, the upper mold pad is placed on the upper part of the upper mold middle ring, the upper mold outer ring is connected to the upper template A by bolts, and the guide sleeves are respectively pressed into the four corner positions of the upper template A.

[0021] S2: Assembly of the lower die floating component;

[0022] Press the first-order lower die into the outer ring of the lower die, place the lower die pad under the lower ring of the lower die, and connect the lower die outer ring to the floating template with bolts.

[0023] S3: Assembly of lower mold fixing components;

[0024] Insert the ejector rod A into the ejector pad A, and then insert the assembly into the lower inner hole of the fixed flange. Fix the fixed flange to the lower template A with bolts. Insert the elastic washer I, the steel pad, and the elastic washer II into the step on the outer edge of the fixed flange in sequence. Install several nitrogen spring support seats and bolts on the lower template A. Place the ejector pad into the inner hole of the fixed flange. Press them into the lower template A respectively. Slide the lower die floating assembly assembled in step S2 through the guide post, and then insert the equal height bolts from the floating template into the lower template A and tighten them to limit the lower die floating assembly.

[0025] S4: First-order mold installation;

[0026] After assembling the components in step S1, use bolts to connect the upper template A to the movable crossbeam of the press. After aligning the positions of the first-sequence upper mold assembly and the lower die floating assembly through guide pillars and guide sleeves, use bolts to fix the lower template A to the press. Connect the ejector rod A to the lower ejector cylinder of the press to ensure that the first-sequence upper mold assembly and the lower die floating assembly are concentric and can slide together.

[0027] S5: One-stage extrusion molding;

[0028] The press's moving crossbeam rises, driving the first-order upper die assembly to move. When it moves a certain distance away from the lower die floating assembly, the round bar billet is placed into the first-order lower die. The press's moving crossbeam drives the first-order upper die assembly to press downwards. When the first-order upper die and the first-order lower die contact, a radially extruded cavity is formed. The flow space outlet of this cavity is the waist-shaped through hole in the center of the first-order upper die. As the first-order upper die assembly and the lower die floating assembly continue to move downwards as a whole, the billet is first upset to form a cuboid. Then, the material flows out from the flow space outlet, forming an intermediate forging billet with a waist-shaped column. During the radial extrusion process, after the lower surface of the floating die plate makes rigid contact with the upper surface of the fixed flange, the elastic washer one, elastic washer two, and nitrogen spring will provide an upward resistance to the lower die floating assembly, preventing the lower die floating assembly from moving downwards. When the press reaches the set load, the radial extrusion is completed.

[0029] S6: One-way return pickup;

[0030] After radial extrusion, the movable crossbeam drives the first-order upper die assembly to return upward. At the same time, the nitrogen spring and elastic washers one and two also push the lower die floating assembly upward under the action of restoring force. When the floating die plate stops at the upper end of the equal-height bolt, the movable crossbeam continues to drive the first-order upper die assembly upward. After moving a certain distance, the movable crossbeam of the press stops moving. The lower ejector cylinder of the press moves upward, thereby pushing the ejector rod A upward. The ejector rod A pushes the ejector pad block upward, the ejector pad block pushes the ejector A upward, and the ejector A pushes the intermediate forging billet upward, thereby ejecting the forging out of the first-order lower die cavity, and finally removing the intermediate forging billet.

[0031] S7: Assembly of the second-order upper mold assembly;

[0032] Press the punch mandrel into the punch, forcefully press the punch into the punch sleeve, and place the punch pad into the inner hole of the punch sleeve; place the upper pad and connecting flange on the lower side of the upper template B and align them with bolts; insert the connecting flange pad and the assembled punch sleeve into the connecting flange and fix them with lock nuts.

[0033] S8: Lower mold assembly;

[0034] Heat the outer ring of the die cavity to 450℃, and when the temperature of the middle ring of the die cavity is 20-50℃, place it in the inner heat-fitting sleeve of the outer ring of the die cavity; align the alignment groove on the outer edge of the second-order lower die cavity body with the position of the semi-circular groove on the inner wall of the middle ring of the die cavity to form a pin hole, and insert the pin for positioning. Then insert the dividing blocks into the middle ring of the die cavity respectively, and forcefully press the second-order lower die cavity into the middle ring of the die cavity. At the same time, under the pressure holding state, screw the threaded pressure ring of the die cavity into the lower end of the punch middle ring; install the die cylinder on the lower template B with bolts, and place the die base pad on the center of the lower template B; The ejector pin B is inserted into the center hole of the mold base pad and the lower template B; the lower end of the ejector B is forcefully pressed into the ejector fixing block; the ejector pad B and the ejector B are placed in the center of the mold base pad in sequence, and then the mold base is placed outside the ejector pad B, with the upper end of the ejector B protruding from the mold base. The assembled second-order lower die is inserted into the ejector B through the central ejector through hole, and the upper step of the mold base is located in the inner hole of the die thread pressure ring; the die cylinder pressure ring is placed on the step of the outer ring of the upper end face of the die outer ring and the die cylinder pressure ring is connected to the die cylinder with bolts.

[0035] S9: Second-order mold installation;

[0036] After aligning the upper and lower die components assembled in step S7 with the punch and the lower die in the second sequence, the upper template B is connected to the movable crossbeam of the press using bolts. The ejector rod A is connected to the lower ejector cylinder of the press. The lower die component is fixed to the press with bolts, and the ejector rod B is connected to the lower ejector cylinder of the press.

[0037] S9: Two-stage extrusion molding;

[0038] As the press's moving crossbeam rises, it drives the upper die assembly of the second-stage die upwards. When the upper die assembly is a certain distance away, the intermediate forging blank is placed into the cavity groove of the lower die of the second-stage die. The press's moving crossbeam drives the punch downwards, and the punch extends into the cavity groove of the lower die of the second-stage die. The waist-shaped boss of the intermediate forging blank extends into the inner hole of the punch. When the second-stage extrusion begins, the lower end face of the punch contacts the large end face of the intermediate forging blank, and the lower end face of the punch mandrel contacts the upper end face of the waist-shaped column. As the press's moving crossbeam continues to move downwards, the punch gradually moves downwards through layer-by-layer pressure transmission, pushing the intermediate forging blank downwards to produce plastic deformation. During the extrusion process, the T-shaped connecting body, the arcs of connecting end a and connecting end c, and four sealing ring grooves along the contour are formed in sequence. When the lower surface of the punch sleeve is in rigid contact with the upper surface of the lower die of the second-stage die, or when the press reaches the set load, the upper die assembly of the second-stage die can no longer move downwards, and the radial extrusion is completed.

[0039] S10: Second return trip for pickup;

[0040] After the second extrusion is completed, the movable crossbeam drives the second-stage upper die assembly to return upward. After the second-stage upper die assembly and the lower die assembly are separated by a certain distance, the movable crossbeam of the press stops moving. The lower ejector cylinder of the press moves upward, thereby pushing the ejector rod B to move upward. The ejector rod B pushes the ejector pad B and the ejector B to move upward. The ejector B pushes the second-stage extruded forging to move upward, thereby ejecting the second-stage extruded forging from the second-stage lower die and taking it out.

[0041] Due to the adoption of the technical solution described above, the present invention has the following advantages:

[0042] This invention combines primary and secondary extrusion to achieve a rational distribution of material flow between the two processes. Primary extrusion distributes the material before secondary extrusion completes the final forming, which is beneficial for the plastic forming of metal and increases mold life. Since the junction between the waist-shaped column and the T-shaped connecting body is a sharp angle, the two-stage extrusion method alters the metal flow pattern during forging, avoiding material tearing at the sharp angle. This results in a streamlined part with good mechanical properties and ensures electrical conductivity. Secondary forming combined with minimal machining reduces cutting allowances and cutting surfaces, improves raw material utilization, increases production efficiency, reduces production costs, and enhances market competitiveness. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the contact pin component of the present invention.

[0044] Figure 2 This is a diagram showing the process of the contact pin part of the present invention changing sequentially from bar stock, first-stage extrusion, second-stage extrusion, and machining.

[0045] Figure 3This is a schematic diagram of the first-order extrusion die of the present invention before extrusion.

[0046] Figure 4 This is a cross-sectional schematic diagram of the extrusion die of the present invention before extrusion.

[0047] Figure 5 This is a cross-sectional schematic diagram of the extrusion die of the present invention after extrusion.

[0048] Figure 6 This is a schematic diagram of a pre-formed upper die of the present invention.

[0049] Figure 7 This is a schematic diagram of a first-order lower die of the present invention.

[0050] Figure 8 This is an overall schematic diagram of the two-stage extrusion die of the present invention.

[0051] Figure 9 This is a cross-sectional schematic diagram of the two-stage extrusion die of the present invention before extrusion.

[0052] Figure 10 This is a cross-sectional schematic diagram of the two-stage extrusion die of the present invention after extrusion.

[0053] Figure 11 This is a schematic diagram of the engagement between the punch mandrel and the punch of the present invention.

[0054] Figure 12 This is an exploded view of the two-stage lower die of the present invention.

[0055] Figure 13 This is a schematic diagram of the inner ring of the die of the present invention.

[0056] In the diagram: a - connection end with a cuboid shape, b - waist-shaped column connection end, c - connection end with internal threaded hole, d - four sealing ring grooves along the contour, e - T-type connection body.

[0057] 1-Upper template A, 2-Upper mold pad, 3-Upper mold middle ring, 4-Upper mold outer ring, 5-Guide sleeve, 6-First-order upper die, 7-First-order lower die, 8-Lower die outer ring, 9-Lower die pad, 10-Floating template, 11-Ejector A, 12-Ejector pad, 13-Fixed flange, 14-Elastic washer one, 15-Steel pad, 16-Elastic washer two, 17-Ejector rod A, 18-Ejector pad A, 19-Lower template A, 20-Nitrogen spring, 21-Equal height bolt, 22-Guide post, 23-Upper template B, 24-Upper pad, 25-Connecting flange pad, 26-Connecting flange, 27-Punch pad, 28-Punch sleeve, 29-Locking nut, 30 - Punch, 301-Punch A, 302-Allowing groove, 31-Punch mandrel, 32-Secondary lower die, 321-Main body, 3211-Cavity groove, 3212-Alignment groove, 3213-Boss, 3214-Punch B, 322-Divider block, 33-Die middle ring, 331-Semi-circular groove, 332-Pin removal hole, 34-Die outer ring, 35-Die threaded pressure ring, 36-Ejector B, 37-Die base, 38-Ejector pad B, 39-Die base pad, 40-Ejector rod B, 41-Lower template B, 42-Ejector fixing block, 43-Die cylinder, 44-Die cylinder pressure ring, 45-Bar stock, 46-Intermediate forging, 47-Secondary extrusion forging. Detailed Implementation

[0058] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments. However, this should not be construed as limiting the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0059] Combined with appendix Figure 1-13 A cold extrusion forming process for contact pin parts includes: bar blanking → sandblasting → cleaning → first-stage extrusion → deburring → sandblasting → cleaning → second-stage extrusion → machining.

[0060] The first extrusion is a positive extrusion, which forms the bar billet 45 into an intermediate forging billet 46 with a waist-shaped boss; the second extrusion is a composite extrusion, which forms the connecting end a, the waist-shaped column connecting end b, the connecting end c, four sealing ring grooves d along the contour, and the T-shaped connecting body e; the machining includes machining the cuboid of the connecting end a, the waist-shaped column end face of the connecting end b, the end face of the connecting end c and the internal thread hole, and the lower end face of the T-shaped connecting body e.

[0061] A cold extrusion forming die for contact pin parts includes a primary extrusion die and a secondary extrusion die.

[0062] The first-order extrusion die includes a first-order upper die assembly, a first-order upper die 6, a first-order lower die 7, a lower die floating assembly, and a lower die fixing assembly. Both the first-order upper die 6 and the first-order lower die 7 are frustum structures. The first-order upper die 6 is tightly fitted at the center of the first-order upper die assembly. The center of the first-order upper die 6 is provided with a waist-shaped through hole that matches the size of the waist-shaped column in the middle of the part. The center of the lower end face is provided with a rectangular funnel-shaped groove around the waist-shaped through hole. The center of the first-order lower die 7 is provided with a rectangular through hole that corresponds to the rectangular funnel-shaped groove of the first-order upper die 6. The first-order lower die 7 is correspondingly located at the center of the lower die floating assembly, which is mounted on the first-order lower die fixing assembly.

[0063] The first-order upper mold assembly includes an upper template A1, an upper mold pad 2, an upper mold middle ring 3, an upper mold outer ring 4, and a guide sleeve 5. The upper template A1 is connected to the movable crossbeam of the press. The upper mold pad 2 and the upper mold middle ring 3 are set inside the upper mold outer ring 4. The upper mold outer ring 4 is fixed to the lower side of the upper template by bolts. The guide sleeves are respectively set at the four corners of the lower side of the upper template A1. The first-order upper concave mold 6 is tightly fitted inside the upper mold middle ring 3.

[0064] The lower die floating assembly includes a lower die outer ring 8, a lower die pad 9, and a floating template 10; a first-order lower die 7 is tightly fitted inside the lower die outer ring 8, the lower die pad 9 is located inside the lower die outer ring 8 below the first-order lower die 7, and the lower die outer ring 8 is bolted to the floating template 10.

[0065] The lower mold fixing assembly includes an ejector A11, an ejector pad 12, a fixing flange 13, a first elastic washer 14, a steel pad 15, a second elastic washer 16, an ejector rod A17, an ejector pad A18, a lower mold plate A19, a nitrogen spring 20, an equalizing bolt 21, and a guide post 22. The fixing flange 13 is mounted on the lower mold plate A19, and the ejector pad A18 is positioned at the center of the lower end of the fixing flange 13. The ejector rod A17 is positioned at the center of the ejector pad A18 via an upper step, and its lower end passes through the lower mold plate A19. The ejector pad 12 is mounted on the ejector pad A18. The ejector A11 is a rectangular bar structure. A rectangular through hole is placed on the ejector pad 12, with its upper end passing through the floating template 10 and the lower die pad 9, and located in the center of the lower die 7. Elastic washer 14, steel pad 15, and elastic washer 26 are arranged from top to bottom on the steps of the outer edge of the fixed flange 13. Nitrogen spring 20 is arranged between the lower template A19 and the floating template 10. Equal height bolt 21 passes through the floating template 10 and is tightened on the lower template A19. Guide post 22 is arranged on the lower template A19, with its upper end passing through the floating template 10 and corresponding to the guide sleeve on the lower side of the upper template. Equal height bolt 21 and guide post 22 are slidably fitted with the floating template 10.

[0066] The two-stage extrusion die includes a two-stage upper die assembly, a punch 30, a punch mandrel 31, a two-stage lower die 32, and a lower die assembly. The punch 30 is located at the center of the two-stage upper die assembly. The punch 30 is a square rod structure. The center of the punch 30 is provided with an oblong through hole that matches the oblong column in the middle of the part. The lower end face of the punch 30 is provided with a protruding ridge A301 for forming a sealing ring groove on the upper end face of the T-shaped connection body of the part. The two ends of the protruding ridge A301 extend to the two sides of the punch mandrel 31 and provide clearance grooves 302. The punch mandrel 31 is a long rod structure with a cross-section consistent with the oblong through hole. The punch mandrel 31 is tightly fitted in the oblong through hole in the center of the punch 30. A gap is left between the lower end face of the punch mandrel 31 and the lower end face of the punch 30 to accommodate the oblong column in the middle of the part. The second-order lower die 32 is located at the center of the lower die assembly. The upper circumference of the second-order lower die 32 is provided with an installation step. The second-order lower die 32 is a split frustum structure, including a main body 321 and a dividing block 322. The middle part of the main body 321 is provided with a square cavity groove 3211 that matches the punch 30. The dividing block 322 is provided at both ends of the cavity groove 3211 in the width direction. The outer edge surface of the main body 321 is symmetrically provided with alignment grooves 3212. The bottom of the cavity groove 3211 is provided with arcs on both sides for forming the lower arc of the part. The bottom of the groove is provided with a boss 3213 for forming the T-shaped connection of the part to the main body 321. The bottom and side wall of the groove are provided with a protruding ridge B3214 for forming the sealing ring groove of the part. The center of the bottom of the groove is provided with an ejector through hole.

[0067] The second-order upper mold assembly includes an upper template B23, an upper pad 24, a connecting flange pad 25, a connecting flange 26, a punch pad 27, a punch sleeve 28, and a locking nut 29. The upper template B23 is connected to the press's movable crossbeam. The upper pad 24 is positioned between the upper template B23 and the connecting flange 26. The connecting flange 26 is connected to the upper pad 24 and the upper template by bolts, and the lower outer edge of the connecting flange 26 is threaded. The punch sleeve 28 and the connecting flange pad 25 are positioned inside the connecting flange 26 by the locking nut 29. The punch 30 is tightly fitted inside the center of the punch sleeve 28, and the punch pad 27 is positioned inside the punch sleeve 28 on the upper side of the punch 30. The lower end of the punch 30 protrudes from the lower end of the punch sleeve 28.

[0068] The lower mold assembly includes a die middle ring 33, a die outer ring 34, a die threaded pressure ring 35, an ejector B36, a mold base 37, an ejector pad B38, a mold base pad 39, an ejector pin B40, a lower mold plate B41, an ejector fixing block 42, a mold cylinder 43, and a mold cylinder pressure ring 44; the die middle ring 33 is heat-fitted into the die outer ring 34, and the inner hole of the die middle ring 33 is an end portion that matches the frustum structure of the second-order lower die 32. A stepped tapered hole is provided. A semi-circular groove 331, corresponding to the alignment groove 3212 on the outer edge of the second-order lower die 32, is provided on the inner wall of the die center ring 33. The alignment groove 3212 and the semi-circular groove 331 together form a pin hole. The semi-circular groove 331 extends upwards along the inner wall to the top of the die center ring 33, forming a pin removal hole 332. The second-order lower die 32 is tightly fitted into the upper part of the die center ring 33. The die threaded pressure ring 35 passes through... The thread is located on the lower side inside the inner ring 33 of the die cavity; the upper step of the die base 37 is located inside the die cavity thread pressure ring 35, and the upper end face is in contact with the lower end face of the second-order lower die cavity 32. The die base 37 is set on the lower template B41 through the die base pad 39; the ejector pin B40 is located at the center of the die base pad 39 and the lower template B41, and the ejector pad B38 is located in the lower center of the die base 37. The upper end of the ejector pin B40 is in contact with the ejector pad B38; the ejector B36 is set on the ejector pad B38 through the ejector fixing block 42; the upper end of the ejector B36 is located in the ejector through hole at the center of the second-order lower die cavity 32; the die cylinder 43 is set on the lower template B41 outside the outer ring 34 of the die cavity by bolts, and the die cylinder pressure ring 44 is set on the upper end of the die cylinder 43 by bolts and is located on the step of the outer ring of the upper end face of the outer ring 34 of the die cavity.

[0069] A method for using a cold extrusion forming die for contact pin parts, the specific steps of which are as follows:

[0070] S1: Assembly of upper mold components in sequence;

[0071] The upper mold middle ring 3 is forcefully pressed into the upper mold outer ring 4, the first-order upper concave mold 6 is forcefully pressed into the upper mold middle ring 3, the upper mold pad 2 is placed on the upper part of the upper mold middle ring 3, the upper mold outer ring 4 is connected to the upper template A1 by bolts, and the guide sleeves are respectively pressed into the four corner positions of the upper template A1.

[0072] S2: Assembly of the lower die floating component;

[0073] Press the lower die 7 into the lower die outer ring 8, place the lower die pad 9 under the lower die outer ring 8, and connect the lower die outer ring 8 to the floating template 10 with bolts.

[0074] S3: Assembly of lower mold fixing components;

[0075] Insert the ejector rod A17 into the ejector pad A18, and then insert the assembly into the lower inner hole of the fixed flange 13. Fix the fixed flange 13 to the lower template A19 with bolts. Insert the elastic washer 14, steel pad 15, and elastic washer 26 into the steps on the outer edge of the fixed flange 13 in sequence. Install several nitrogen spring 20 support seats and bolts on the lower template A19. Place the ejector pad 12 into the inner hole of the fixed flange 13. Press them into the lower template A19 respectively. Slide the lower die floating assembly assembled in step S2 through the guide post 22, and then insert the equal height bolt 21 from the floating template 10 into the lower template A19 and tighten it to limit the lower die floating assembly.

[0076] S4: First-order mold installation;

[0077] After assembling the components in step S1, use bolts to connect the upper template A1 to the movable crossbeam of the press. After aligning the upper mold assembly and the lower die floating assembly with the guide post 22 and the guide sleeve, use bolts to fix the lower template A19 to the press. Connect the ejector rod A17 to the lower ejector cylinder of the press to ensure that the upper mold assembly and the lower die floating assembly are concentric and can slide together.

[0078] S5: One-stage extrusion molding;

[0079] The press's moving crossbeam rises, driving the upper die assembly to move. When it moves a certain distance away from the lower die floating assembly, the round bar billet 45 is placed into the lower die 7. The press's moving crossbeam drives the upper die assembly to press downwards. When the upper die 6 and the lower die 7 come into contact, a radially extruded cavity is formed. The flow space outlet of this cavity is the waist-shaped through hole in the center of the upper die 6. As the upper die assembly and the lower die floating assembly continue to move downwards as a whole, the billet is first upset to form a cuboid. Then, the material flows out from the flow space outlet, forming an intermediate forging billet 46 with a waist-shaped column. During the radial extrusion process, after the lower surface of the floating template 10 rigidly contacts the upper surface of the fixed flange 13, the elastic washer 14, the elastic washer 26, and the nitrogen spring 20 will exert an upward resistance on the lower die floating assembly, preventing it from moving downwards. When the press reaches the set load, the radial extrusion is completed.

[0080] S6: One-way return pickup;

[0081] After radial extrusion, the movable crossbeam drives the first-order upper die assembly to return upward. At the same time, the nitrogen spring 20 and elastic washers 14 and 16 also push the lower die floating assembly upward under the action of restoring force. When the floating template 10 moves to the upper end of the equal-height bolt 21, it stops. The movable crossbeam continues to drive the first-order upper die assembly upward. When it moves a certain distance, the movable crossbeam of the press stops moving. The lower ejector cylinder of the press moves upward, thereby pushing the ejector rod A17 upward. The ejector rod A17 pushes the ejector pad 12 upward. The ejector pad 12 pushes the ejector A11 upward. The ejector A11 pushes the intermediate forging billet upward, thereby ejecting the intermediate forging billet 46 out of the cavity of the first-order lower die 7. Finally, the intermediate forging billet 46 is taken out.

[0082] S7: Assembly of the second-order upper mold assembly;

[0083] Press the punch mandrel 31 into the punch 30, forcefully press the punch 30 into the punch sleeve 28, and place the punch pad 27 into the inner hole of the punch sleeve 28; place the upper pad 24 and the connecting flange 26 on the lower side of the upper template B23 and align them with bolts; install the connecting flange pad 25 and the assembled punch sleeve 28 into the connecting flange 26 and fix them with the lock nut 29.

[0084] S8: Lower mold assembly;

[0085] Heat the outer ring 34 of the die cavity to 450°C. When the temperature of the middle ring 33 of the die cavity is 20-50°C, place it inside the outer ring 34 of the die cavity for heat fitting. Align the positioning groove 3212 on the outer edge of the body 321 of the second-order lower die cavity 32 with the position of the semi-circular groove 331 on the inner wall of the middle ring 33 of the die cavity to form a pin hole, and insert the pin for positioning. Then insert the dividing blocks 322 into the middle ring 33 of the die cavity respectively, and forcefully press the second-order lower die cavity 32 into the middle ring 33 of the die cavity. At the same time, under the pressure holding state, screw the threaded pressure ring 35 of the die cavity into the lower end of the middle ring of the punch 30. Install the mold cylinder 43 on the lower template B41 with bolts, and place the mold base plate 39 on the center of the lower template B41. Insert the ejector pin B40 into the center hole of the mold base plate 39 and the lower template B41; forcefully press the lower end of the ejector B36 into the ejector fixing block 42; place the ejector plate B38 and the ejector B36 in the center of the mold base plate 39 in sequence, and then place the mold base 37 outside the ejector plate B38, with the upper end of the ejector B36 protruding from the mold base 37; insert the assembled second-order lower die 32 into the ejector B36 through the central ejector through hole, with the upper step of the mold base 37 located inside the inner hole of the die thread pressure ring 35; place the die cylinder pressure ring 44 on the step of the outer ring of the upper end face of the die outer ring 34 and connect the die cylinder pressure ring 44 to the die cylinder 43 with bolts.

[0086] S9: Second-order mold installation;

[0087] After aligning the upper and lower die assemblies assembled in step S7 with the punch 30 and the lower die 32, the upper template B23 is connected to the press movable crossbeam using bolts. The ejector rod A is connected to the lower ejector cylinder of the press. The lower die assembly is fixed to the press with bolts, and the ejector rod B40 is connected to the lower ejector cylinder of the press.

[0088] S9: Two-stage extrusion molding;

[0089] As the press's movable crossbeam rises, it drives the upper die assembly of the second-stage die upwards. When the upper die assembly is a certain distance away, the intermediate forging billet 46 is placed into the cavity groove 3211 of the lower die 32 of the second-stage die. The press's movable crossbeam drives the punch 30 downwards, and the punch 30 extends into the cavity groove 3211 of the lower die 32 of the second-stage die. The waist-shaped boss 3213 of the intermediate forging billet 46 extends into the inner hole of the punch 30. When the second-stage extrusion begins, the lower end face of the punch 30 contacts the large end face of the intermediate forging billet 46, and the lower end face of the punch mandrel 31 contacts the waist... The upper surfaces of the die 30 and the middle forging blank 46 are in contact with each other. As the moving crossbeam of the press moves downward continuously, the punch 30 gradually moves downward through the layer-by-layer pressure transmission, which pushes the middle forging blank 46 downward to produce plastic deformation. During the extrusion process, the T-shaped connecting body 321, the arc of connecting end a and connecting end c and four sealing ring grooves along the contour are formed in sequence. When the lower surface of the punch sleeve 28 is in rigid contact with the upper surface of the second-sequence lower die 32 or when the press reaches the set load, the second-sequence upper die assembly can no longer move downward, and the radial extrusion is completed.

[0090] S10: Second return trip for pickup;

[0091] After the second extrusion is completed, the movable crossbeam drives the second-stage upper die assembly to return upward. After the second-stage upper die assembly and the lower die assembly are separated by a certain distance, the movable crossbeam of the press stops moving. The lower ejector cylinder of the press moves upward, thereby pushing the ejector rod B40 to move upward. The ejector rod B40 pushes the ejector pad B38 and the ejector B36 to move upward. The ejector B36 pushes the second-stage extruded forging 47 to move upward, thereby ejecting the second-stage extruded forging 47 out of the second-stage lower die 32 and taking it out.

[0092] The parts of this invention not described in detail are prior art.

[0093] The embodiments selected herein for the purpose of disclosing the inventive objectives are currently considered suitable; however, it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of this concept and invention.

Claims

1. A contact pin part cold extrusion forming die characterized by: Including first-stage extrusion dies and second-stage extrusion dies; The first-order extrusion die includes a first-order upper die assembly, a first-order upper die, a first-order lower die, a lower die floating assembly, and a lower die fixing assembly. Both the first-order upper die and the first-order lower die have a frustum structure. The first-order upper die is tightly fitted at the center of the first-order upper die assembly. The center of the first-order upper die has a waist-shaped through hole that matches the size of the waist-shaped column in the middle of the part. The center of the lower end face has a rectangular funnel-shaped groove around the waist-shaped through hole. The center of the first-order lower die has a rectangular through hole that corresponds to the rectangular funnel-shaped groove of the first-order upper die. The first-order lower die is correspondingly located at the center of the lower die floating assembly, which is mounted on the first-order lower die fixing assembly. The two-stage extrusion die includes a two-stage upper die assembly, a punch, a punch mandrel, a two-stage lower die, and a lower die assembly. The punch is located at the center of the two-stage upper die assembly and is a square rod structure. A waist-shaped through hole matching the waist-shaped column in the middle of the part is provided at the center of the punch. A protruding ridge A for forming a sealing ring groove on the upper surface of the T-shaped connection body of the part is provided on the lower end face of the punch. Avoidance grooves extend from both ends of the protruding ridge A to the two sides of the punch mandrel. The punch mandrel is a long rod-shaped structure with a cross-section consistent with the waist-shaped through hole. The punch mandrel is tightly fitted into the waist-shaped through hole at the center of the punch. A space is left between the lower end face of the punch mandrel and the lower end face of the punch to accommodate the part. The gap of the central waist-shaped column; the second-order lower die is set in the center of the lower die assembly, and the upper circumference of the second-order lower die is provided with an installation step. The second-order lower die is a split frustum structure, including a main body and dividing blocks; the middle of the main body is set with a square cavity groove that matches the punch, and the dividing blocks are set opposite to each other at both ends of the cavity groove in the width direction; the outer edge surface of the main body is symmetrically provided with alignment grooves, the bottom of the cavity groove is set with arcs on both sides for the lower arc forming of the part, the bottom of the groove is provided with a boss for the T-shaped connection of the part to the main body forming, and the bottom and side walls of the groove are provided with a protruding ridge B for the forming of the sealing ring groove of the part; the center of the bottom of the groove is provided with an ejector through hole.

2. The cold extrusion forming die for a contact pin part according to claim 1, characterized in that: The first-order upper mold assembly includes an upper template A, an upper mold pad, an upper mold middle ring, an upper mold outer ring, and guide sleeves; the upper template A is connected to the movable crossbeam of the press, the upper mold pad and the upper mold middle ring are set inside the upper mold outer ring, the upper mold outer ring is fixed to the lower side of the upper template A by bolts, and the guide sleeves are respectively set at the four corners of the lower side of the upper template A; the first-order upper concave mold is tightly fitted inside the upper mold middle ring.

3. The cold extrusion forming die for a contact pin part according to claim 2, characterized in that: The lower die floating assembly includes a lower die outer ring, a lower die pad, and a floating template; a first-order lower die is tightly fitted inside the lower die outer ring, the lower die pad is located inside the lower die outer ring on the lower side of the first-order lower die, and the lower die outer ring is bolted to the floating template.

4. The cold extrusion forming die for a contact pin part according to claim 3, characterized in that: The lower mold fixing assembly includes an ejector A, an ejector pad, a fixing flange, a first elastic washer, a steel pad, a second elastic washer, an ejector rod A, an ejector pad A, a lower mold plate A, a nitrogen spring, equal-height bolts, and guide pillars. The fixing flange is mounted on the lower mold plate A, and the ejector pad A is positioned inside the center of the lower end of the fixing flange. The ejector rod A is positioned at the center of the ejector pad A via an upper step, and its lower end passes through the lower mold plate A. The ejector pad is mounted on the ejector pad A. The ejector A is a rectangular rod structure. The top end of the ejector pad passes through the floating template and the lower die pad in sequence and is located in the rectangular through hole at the center of the lower die. Elastic washer one, steel pad and elastic washer two are set on the steps on the outer edge of the fixed flange from top to bottom. Nitrogen spring is set between the lower template A and the floating template. The equal height bolt passes through the floating template and is tightened on the lower template A. The guide post is set on the lower template A, and the upper end of the guide post passes through the floating template and is set to correspond with the guide sleeve on the lower side of the upper template. The equal height bolt and the guide post are slidably fitted with the floating template.

5. The cold extrusion forming die for a contact pin part according to claim 4, characterized in that: The two-stage upper mold assembly includes an upper template B, an upper pad, a connecting flange pad, a connecting flange, a punch pad, a punch sleeve, and a lock nut. The upper template B is connected to the press's movable crossbeam. The upper pad is positioned between the upper template B and the connecting flange. The connecting flange is connected to the upper pad and the upper template by bolts, and the lower outer edge of the connecting flange is threaded. The punch sleeve and the connecting flange pad are positioned inside the connecting flange by a lock nut. The punch is tightly fitted inside the center of the punch sleeve, and the punch pad is positioned inside the punch sleeve on the upper side of the punch. The lower end of the punch protrudes from the lower end of the punch sleeve.

6. The cold extrusion forming die for a contact pin part according to claim 5, characterized in that: The lower mold assembly includes a die middle ring, a die outer ring, a die threaded pressure ring, an ejector B, a mold base, an ejector pad B, a mold base pad, an ejector pin B, a lower template B, an ejector fixing block, a mold cylinder, and a mold cylinder pressure ring. The die middle ring is heat-fitted into the die outer ring, and the second-order lower die is tightly fitted into the upper part of the die middle ring. The die threaded pressure ring is threaded into the lower side of the die middle ring. The upper stepped portion of the mold base is located inside the die threaded pressure ring, and its upper end face contacts the lower end face of the second-order lower die. The mold base is connected via a mold base... The pad is set on the lower template B; the ejector pin B is set at the center of the mold base pad and the lower template B; the ejector pad B is set inside the center of the lower end of the mold base; the upper end of the ejector pin B is in contact with the ejector pad B; the ejector B is set on the ejector pad B through the ejector fixing block; the upper end of the ejector B is located in the ejector through hole at the center of the second-order lower die; the mold cylinder is set on the lower template B outside the outer ring of the die through bolts; the mold cylinder pressure ring is set on the upper end of the mold cylinder through bolts and is set on the step of the outer ring of the upper end face of the outer ring of the die.

7. The cold extrusion forming die for a contact pin part according to claim 6, characterized in that: The inner hole of the die cavity is a tapered hole with a stepped end that matches the frustum structure of the second-order lower die cavity. The inner wall of the die cavity is provided with a semi-circular groove corresponding to the alignment groove on the outer edge of the second-order lower die cavity. The alignment groove and the semi-circular groove together form a pin hole. The semi-circular groove extends upward along the inner wall to the top of the die cavity to form a pin removal hole.

8. A method of using a cold extrusion forming die for a contact pin part as described in claim 7, characterized in that: S1: Assembly of upper mold components in sequence; The upper mold middle ring is forcefully pressed into the upper mold outer ring, the first sequence upper die is forcefully pressed into the upper mold middle ring, the upper mold pad is placed on the upper part of the upper mold middle ring, the upper mold outer ring is connected to the upper template A by bolts, and the guide sleeves are respectively pressed into the four corners of the upper template A. S2: Assembly of the lower die floating component; Press the first-order lower die into the outer ring of the lower die, and place the lower die pad under the lower ring of the lower die. Connect the lower die outer ring to the floating template with bolts. S3: Assembly of lower mold fixing components; Insert the ejector pin A into the ejector pad A, and insert the assembly into the lower inner hole of the fixed flange; fix the fixed flange to the lower template A with bolts; install the elastic washer one, the steel pad, and the elastic washer two in sequence onto the step on the outer edge of the fixed flange; install several nitrogen spring support seats and bolts on the lower template A; place the ejector pad block into the inner hole of the fixed flange; slide the lower die floating assembly assembled in step S2 through the guide post, and then insert the equal height bolt from the floating template into the lower template A and tighten it to limit the lower die floating assembly; S4: First-order mold installation; After assembling the components in step S1, use bolts to connect the upper template A to the movable crossbeam of the press. After aligning the positions of the first-sequence upper mold assembly and the lower die floating assembly through guide pillars and guide sleeves, use bolts to fix the lower template A to the press. Connect the ejector rod A to the lower ejector cylinder of the press to ensure that the first-sequence upper mold assembly and the lower die floating assembly are concentric and can slide and connect. S5: One-stage extrusion molding; The press's moving crossbeam rises, driving the first-order upper die assembly to move. When it moves a certain distance away from the lower die floating assembly, the round bar billet is placed into the first-order lower die. The press's moving crossbeam drives the first-order upper die assembly to press downwards. When the first-order upper die and the first-order lower die contact, a radially extruded cavity is formed. The flow space outlet of this cavity is the waist-shaped through hole in the center of the first-order upper die. As the first-order upper die assembly and the lower die floating assembly continue to move downwards as a whole, the billet is first upset to form a cuboid. Then, the material flows out from the flow space outlet, forming an intermediate forging billet with a waist-shaped column. During the radial extrusion process, after the lower surface of the floating die plate makes rigid contact with the upper surface of the fixed flange, the elastic washer one, the elastic washer two, and the nitrogen spring will exert an upward resistance on the lower die floating assembly, preventing the lower die floating assembly from moving downwards. When the press reaches the set load, the radial extrusion is completed. S6: One-way return pickup; After radial extrusion, the movable crossbeam drives the first-order upper die assembly to return upward. At the same time, the nitrogen spring and elastic washers one and two also push the lower die floating assembly upward under the action of restoring force. When the floating die plate stops at the upper end of the equal height bolt, the movable crossbeam continues to drive the first-order upper die assembly upward. After moving a certain distance, the movable crossbeam of the press stops moving. The lower ejector cylinder of the press moves upward, thereby pushing the ejector rod A upward. The ejector rod A pushes the ejector pad block upward, the ejector pad block pushes the ejector A upward, and the ejector A pushes the intermediate forging billet upward, thereby ejecting the forging out of the first-order lower die cavity. Finally, the intermediate forging billet is taken out. S7: Assembly of the second-order upper mold assembly; Press the punch mandrel into the punch, forcefully press the punch into the punch sleeve, and place the punch pad into the inner hole of the punch sleeve; place the upper pad and connecting flange on the lower side of the upper template B and align them with bolts; insert the connecting flange pad and the assembled punch sleeve into the connecting flange and fix them with lock nuts; S8: Lower mold assembly; Heat the outer ring of the die cavity to 450℃, and when the temperature of the middle ring of the die cavity is 20-50℃, place it in the inner heat-fitting sleeve of the outer ring of the die cavity; align the alignment groove on the outer edge of the second-order lower die cavity body with the position of the semi-circular groove on the inner wall of the middle ring of the die cavity to form a pin hole, and insert the pin for positioning. Then insert the dividing blocks into the middle ring of the die cavity respectively, and forcefully press the second-order lower die cavity into the middle ring of the die cavity. At the same time, under the pressure holding state, screw the threaded pressure ring of the die cavity into the lower end of the punch middle ring; install the die cylinder on the lower template B with bolts, and place the die base pad on the center of the lower template B; The ejector pin B is inserted into the center hole of the mold base pad and the lower template B; the lower end of the ejector B is forcefully pressed into the ejector fixing block; the ejector pad B and the ejector B are placed in the center of the mold base pad in sequence, and then the mold base is placed outside the ejector pad B, with the upper end of the ejector B protruding from the mold base. The assembled second-order lower die is inserted into the ejector B through the central ejector through hole, and the upper step of the mold base is located in the inner hole of the die thread pressure ring; the die cylinder pressure ring is placed on the step of the outer ring of the upper end face of the die outer ring and the die cylinder pressure ring is connected to the die cylinder with bolts. S9: Second-order mold installation; After aligning the upper and lower mold components assembled in step S7 with the punch and the lower die in the second sequence, the upper template B is connected to the movable crossbeam of the press using bolts, the ejector rod A is connected to the lower ejector cylinder of the press, the lower mold component is fixed to the press with bolts, and the ejector rod B is connected to the lower ejector cylinder of the press. S10: Two-stage extrusion molding; As the press's movable crossbeam rises, it drives the upper die assembly of the second-stage die upwards. When it is a certain distance away from the lower die assembly, the intermediate forging blank is placed into the cavity groove of the lower die of the second-stage die. The press's movable crossbeam drives the punch downwards, and the punch extends into the cavity groove of the lower die of the second-stage die. The waist-shaped boss of the intermediate forging blank extends into the inner hole of the punch. When the second-stage extrusion begins, the lower end face of the punch contacts the large end face of the intermediate forging blank, and the lower end face of the punch mandrel contacts the upper end face of the waist-shaped column. As the press's movable crossbeam continues to move downwards, the punch gradually moves downwards through layer-by-layer pressure transmission, pushing the intermediate forging blank downwards to produce plastic deformation. During the extrusion process, the T-shaped connecting body, the arcs of connecting end a and connecting end c, and four sealing ring grooves along the contour are formed in sequence. When the lower surface of the punch sleeve is in rigid contact with the upper surface of the lower die of the second-stage die, or when the press reaches the set load, the upper die assembly of the second-stage die can no longer move downwards, and the radial extrusion is completed. S11: Second return trip for pickup; After the second extrusion is completed, the movable crossbeam drives the second-stage upper die assembly to return upward. After the second-stage upper die assembly and the lower die assembly are separated by a certain distance, the movable crossbeam of the press stops moving. The lower ejector cylinder of the press moves upward, thereby pushing the ejector rod B to move upward. The ejector rod B pushes the ejector pad B and the ejector B to move upward. The ejector B pushes the second-stage extruded forging to move upward, thereby ejecting the second-stage extruded forging from the second-stage lower die and taking it out.

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