Cold extrusion forming process and die for contact pin part and using method of die

Abstract

The invention discloses a contact pin part cold extrusion forming process, a die and a die using method. The contact pin part cold extrusion forming process comprises the steps of bar punching and blanking, sand blowing, cleaning, primary extrusion, deburring, sand blowing, cleaning, secondary extrusion and machining. The forming die comprises a first-order extrusion die and a second-order extrusion die. Through combination of first-order extrusion and second-order extrusion, material flow of the first-order extrusion and the second-order extrusion can be reasonably distributed, plastic forming of metal is facilitated, and the service life of the die is prolonged; as the junction of the waist-shaped column and the T-shaped connecting main body is in a sharp corner state, a forge piece forming metal flowing mode is changed through a two-sequence extrusion mode, the problem of material tearing at the sharp corner is avoided, the streamline of the part is complete, the mechanical property is good, and the conductivity of the part is ensured; secondary forming is matched with little machining, the cutting allowance and the cutting face are reduced, the utilization rate of raw materials is increased, the production efficiency is improved, the production cost is reduced, and the market competitiveness is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal cold forging forming process and die, in particular to a cold extrusion forming process, die and die using method of contact pin part. BACKGROUND

[0002] The contact pin part of new energy vehicle is mainly used in a direct current contactor and is one of the core components of the direct current contactor. Figure 1 As shown in the figure, the part structure includes a connecting end a with a square body, a waist column connecting end b, a connecting end c with an internal thread hole, four sealing ring grooves along the contour d, and a T-shaped connecting main body e. The lower ends of the connecting end a, the connecting end c and the T-shaped connecting main body e are both circular arc transitions on both sides and the bottom surface. The contour precision error of the connecting end with a square body, the waist column connecting end and the connecting end with an internal thread hole is ±0.02mm, so that the contact pin has good structural strength and good electrical conductivity performance requirements, and can be used in complex use environments such as high temperature, vibration and frequent opening and closing. Therefore, the design and manufacturing process must have high precision, high stability and good protection performance.

[0003] At present, the existing technical scheme 1 adopts a milling process, and the single piece processing time is 25 minutes, the material utilization rate is 41.5%, the machining efficiency is low, which is not conducive to reducing the cost, and cannot meet the demand of large batch supply. Moreover, the material itself flow line will be broken in the cutting process, which has a great influence on the fatigue performance of the part itself. The existing technical scheme 2 adopts an open die forging forming + trimming process. The contour of the process required to contact the injection mold needs to be milled to ensure the assembly size gap of 0.03-0.04mm, otherwise there is a risk of glue leakage. The machined part is 50% more than the cold extrusion forming, which prolongs the processing time. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, provide a cold extrusion forming process, die and die using method of contact pin part, improve the processing efficiency and ensure the processing precision.

[0005] The technical scheme adopted by the present application is: A cold extrusion forming process of a contact pin part, comprising: rod punching and cutting → sand blasting → cleaning → first extrusion → deburring → sand blasting → cleaning → second extrusion → machining; The first extrusion is a positive extrusion, which forms a middle forging blank with a waist-shaped boss from a rod blank. The second extrusion is a composite extrusion, which forms the connecting end a, the waist column connecting end b, the connecting end c, the four sealing ring grooves along the contour and the T-shaped connecting main body. The machining includes machining the square body of the connecting end a, the waist-shaped column end face of the connecting end b, the end face and internal thread hole of the connecting end c, and the lower end face of the T-shaped connecting main body.

[0006] The contact pin part cold extrusion forming die comprises a first extrusion die and a second extrusion die. The first extrusion die comprises a first upper die assembly, a first upper die, a first lower die, a lower die floating assembly and a lower die fixed assembly; the first upper die and the first lower die are both circular truncated cone structures, the first upper die is tightly fitted in the center of the first upper die assembly, the first upper die is provided with a waist-shaped through hole matched with the waist-shaped column in the middle part of the part, and a rectangular funnel-shaped groove is arranged around the waist-shaped through hole in the center of the lower end face; the first lower die is provided with a rectangular through hole corresponding to the rectangular funnel-shaped groove of the first upper die in the center; the first lower die is arranged in the center of the lower die floating assembly corresponding to the first upper die, and the lower die floating assembly is arranged on the first lower die fixed assembly. The second extrusion die comprises a second upper die assembly, a punch, a punch shaft, a second lower die and a lower die assembly; the punch is arranged in the center of the second upper die assembly, the punch is a square rod structure, the punch is provided with a waist-shaped through hole matched with the waist-shaped column in the middle part of the part in the center, and the lower end face of the punch is provided with a convex rib A for forming a sealing ring groove on the upper end face of the T-shaped connection body of the part; the convex rib A is provided with an avoiding groove extending to the two side faces of the punch shaft along the two ends of the convex rib A; the punch shaft is a long rod structure with a cross section consistent with the waist-shaped through hole, the punch shaft is tightly fitted in the waist-shaped through hole in the center of the punch, and a gap for accommodating the waist-shaped column in the middle part of the part is left between the lower end face of the punch shaft and the lower end face of the punch; the second lower die is arranged in the center of the lower die assembly, the upper end circumference of the second lower die is provided with a mounting step, the second lower die is a split type circular truncated cone structure comprising a main body and a split block; the middle part of the main body is provided with a square cavity groove matched with the punch, and the split block is arranged on the two ends of the cavity groove in the width direction; the outer edge face of the main body is symmetrically provided with a positioning groove, the two sides of the groove bottom of the cavity groove are provided with an arc for forming a lower end arc of the part, the groove bottom is provided with a convex platform for forming a T-shaped connection body of the part, and the groove bottom and the side wall are provided with a convex rib B for forming a sealing ring groove of the part; the groove bottom is provided with a top piece through hole.

[0007] Specifically, the first upper die assembly comprises an upper die plate A, an upper die pad, an upper die middle ring, an upper die outer ring and a guide sleeve; the upper die plate A is connected with the movable cross beam of the press, the upper die pad and the upper die middle ring are arranged in the upper die outer ring, the upper die outer ring is fixed on the lower side of the upper die plate A through bolts, and the guide sleeve is arranged at the four corner positions of the lower side of the upper die plate A; the first upper die is tightly fitted in the upper die middle ring.

[0008] Specifically, the lower die floating assembly comprises a lower die outer ring, a lower die pad and a floating die plate; the first lower die is tightly fitted in the lower die outer ring, the lower die pad is arranged in the lower die outer ring on the lower side of the first lower die, and the lower die outer ring is arranged on the floating die plate through bolts.

[0009] Specifically, the lower mold fixed assembly includes a top piece A, a top piece pad, a fixed flange, an elastic washer I, a steel pad plate, an elastic washer II, a top rod A, a top piece pad A, a lower mold plate A, a nitrogen spring, an equal height bolt, and a guide column; the fixed flange is arranged on the lower mold plate A, and the top piece pad A is arranged in the center of the lower end of the fixed flange; the top rod A is arranged in the center of the top piece pad A through the upper end step and is arranged through the lower end of the lower mold plate A; the top piece pad is arranged on the top piece pad A, the top piece A is a rectangular bar structure, the top piece A is arranged on the top piece pad and the upper end is sequentially arranged in the rectangular through hole in the center of the lower concave die through the floating mold plate and the lower concave die pad; the elastic washer I, the steel pad plate, and the elastic washer II are sequentially arranged on the step at the outer edge of the fixed flange from top to bottom; the nitrogen spring is arranged between the lower mold plate A and the floating mold plate; the equal height bolt is arranged on the lower mold plate A after passing through the floating mold plate and being tightly screwed; the guide column is arranged on the lower mold plate A, and the upper end of the guide column is correspondingly arranged through the floating mold plate and the guide sleeve on the lower side of the upper mold plate; the equal height bolt and the guide column are arranged in sliding fit with the floating mold plate.

[0010] Specifically, the two-sequence upper mold assembly includes an upper mold plate B, an upper pad, a connecting flange pad, a connecting flange, a punch pad, a punch sleeve, and a locking nut; the upper mold plate B is connected with the movable cross beam of the press, the upper pad is arranged between the upper mold plate B and the connecting flange, the connecting flange is connected with the upper pad and the upper mold plate through bolts, and a thread is arranged on the lower end outer edge of the connecting flange; the punch sleeve and the connecting flange pad are arranged in the connecting flange through the locking nut; the punch is arranged in the center of the punch sleeve in tight fit, the punch pad is arranged in the punch sleeve on the upper side of the punch, and the lower end of the punch protrudes from the lower end of the punch sleeve.

[0011] Specifically, the lower mold assembly includes a concave die middle ring, a concave die outer ring, a concave die threaded compression ring, a top piece B, a mold base, a top piece pad B, a mold base pad, a top rod B, a lower mold plate B, a top piece fixing block, a mold cylinder, and a mold cylinder compression ring; the concave die middle ring is arranged in the concave die outer ring in thermal fit, and the two-sequence lower concave die is arranged in the upper part of the concave die middle ring in tight fit; the concave die threaded compression ring is arranged on the lower side of the concave die middle ring through threads; the upper end step of the mold base is arranged in the concave die threaded compression ring, the upper end face is arranged in contact with the lower end face of the two-sequence lower concave die, the mold base is arranged on the lower mold plate B through the mold base pad; the top rod B is arranged in the center of the mold base pad and the lower mold plate B, the top piece pad B is arranged in the center of the lower end of the mold base, and the upper end of the top rod B is arranged in contact with the top piece pad B; the top piece B is arranged on the top piece pad B through the top piece fixing block; the upper end of the top piece B is arranged in the top piece through hole in the center of the two-sequence lower concave die; the mold cylinder is arranged on the lower mold plate B outside the concave die outer ring through bolts, and the mold cylinder compression ring is arranged on the upper end of the mold cylinder through bolts and is arranged on the step of the outer ring of the upper end face of the concave die outer ring.

[0012] 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.

[0013] A method for using a cold extrusion forming die for contact pin parts, the specific steps of which are as follows: S1: Assembly of upper mold components in sequence; 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.

[0014] S2: Assembly of the lower die floating component; 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.

[0015] S3: Assembly of lower mold fixing components; 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.

[0016] 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 together.

[0017] 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, 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.

[0018] 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, and finally removing the intermediate forging billet.

[0019] 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.

[0020] 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.

[0021] S9: Second-order mold installation; 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.

[0022] S9: Two-stage extrusion molding; 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.

[0023] S10: 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.

[0024] Due to the adoption of the technical solution described above, the present invention has the following advantages: 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

[0025] Figure 1 This is a schematic diagram of the contact pin component of the present invention.

[0026] 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.

[0027] Figure 3 This is a schematic diagram of the first-order extrusion die of the present invention before extrusion.

[0028] Figure 4 This is a cross-sectional schematic diagram of the extrusion die of the present invention before extrusion.

[0029] Figure 5 This is a cross-sectional schematic diagram of the extrusion die of the present invention after extrusion.

[0030] Figure 6 This is a schematic diagram of a pre-formed upper die of the present invention.

[0031] Figure 7 This is a schematic diagram of a first-order lower die of the present invention.

[0032] Figure 8 This is an overall schematic diagram of the two-stage extrusion die of the present invention.

[0033] Figure 9 This is a cross-sectional schematic diagram of the two-stage extrusion die of the present invention before extrusion.

[0034] Figure 10 This is a cross-sectional schematic diagram of the two-stage extrusion die of the present invention after extrusion.

[0035] Figure 11 This is a schematic diagram of the engagement between the punch mandrel and the punch of the present invention.

[0036] Figure 12 This is an exploded view of the two-stage lower die of the present invention.

[0037] Figure 13 This is a schematic diagram of the inner ring of the die of the present invention.

[0038] 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.

[0039] 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

[0040] 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.

[0041] Combined with appendix Figures 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.

[0042] 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.

[0043] A cold extrusion forming die for contact pin parts includes a primary extrusion die and a secondary extrusion die.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] A method for using a cold extrusion forming die for contact pin parts, the specific steps of which are as follows: S1: Assembly of upper mold components in sequence; 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.

[0052] S2: Assembly of the lower die floating component; 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.

[0053] S3: Assembly of lower mold fixing components; 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.

[0054] S4: First-order mold installation; 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.

[0055] S5: One-stage extrusion molding; 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.

[0056] 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 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.

[0057] S7: Assembly of the second-order upper mold assembly; 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.

[0058] S8: Lower mold assembly; 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.

[0059] S9: Second-order mold installation; 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.

[0060] S9: Two-stage extrusion molding; 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.

[0061] S10: 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 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.

[0062] The parts of this invention not described in detail are prior art.

[0063] 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 process for cold extrusion forming of a contact pin part, characterized by: Bar punching down material → sand blasting → cleaning → one sequence extrusion → deburring → sand blasting → cleaning → two sequence extrusion → machining; The one sequence extrusion is positive extrusion, and the bar blank is formed into an intermediate forging blank with a waist-shaped boss; the two sequence extrusion is composite extrusion, and an end a, a waist-shaped column connecting end, an end c, four sealing ring grooves along the contour and a T-shaped connecting body are formed; The machining includes machining a four-square end a, a waist-shaped column end face of the end b, an end face and an internal thread hole of the end c and a lower end face of the T-shaped connecting body.

2. A contact pin part cold extrusion forming die characterized by: The one sequence extrusion die and the two sequence extrusion die are included; The one sequence extrusion die includes a one sequence upper die assembly, a one sequence upper die, a one sequence lower die, a lower die floating assembly and a lower die fixed assembly; the one sequence upper die and the one sequence lower die are both circular table structures, the one sequence upper die is tightly fitted in the center of the one sequence upper die assembly, the center of the one sequence upper die is provided with a waist-shaped through hole matched with the size of the waist-shaped column in the middle part of the part, and a rectangular funnel-shaped recess is arranged around the waist-shaped through hole in the center of the lower end face; the center of the one sequence lower die is provided with a rectangular through hole corresponding to the rectangular funnel-shaped recess of the one sequence upper die; the one sequence lower die is arranged in the center of the lower die floating assembly corresponding to the one sequence upper die, and the lower die floating assembly is arranged on the one sequence lower die fixed assembly; The two sequence extrusion die includes a two sequence upper die assembly, a punch, a punch shaft, a two sequence lower die and a lower die assembly; the punch is arranged in the center of the two sequence upper die assembly, the punch is a square rod structure, the center of the punch is provided with a waist-shaped through hole matched with the waist-shaped column in the middle part of the part, a convex rib A for forming a sealing ring groove on the upper end face of the T-shaped connecting body of the part is arranged on the lower end face of the punch, and an avoiding groove is arranged on the two side faces of the punch shaft extending from the two ends of the convex rib A to the two sides of the punch shaft; the punch shaft is a long rod structure with a cross section consistent with the waist-shaped through hole, the punch shaft is tightly fitted in the waist-shaped through hole in the center of the punch, and a gap for accommodating the waist-shaped column in the middle part of the part is left between the lower end face of the punch shaft and the lower end face of the punch; the two sequence lower die is arranged in the center of the lower die assembly, a mounting step is arranged on the upper end circumference of the two sequence lower die, the two sequence lower die is a split circular table structure including a main body and split blocks; the middle part of the main body is provided with a square cavity recess matched with the punch, and the split blocks are oppositely arranged on the two ends in the width direction of the cavity recess; the outer edge face of the main body is symmetrically provided with alignment grooves, the two sides of the groove bottom of the cavity recess are provided with arcs for forming a lower end arc of the part, a convex boss is arranged on the groove bottom for forming the T-shaped connecting body of the part, and convex ribs B are arranged on the groove bottom and the side wall for forming a sealing ring groove of the part; a top piece through hole is arranged in the center of the groove bottom.

3. The contact pin part cold extrusion forming die according to claim 2, characterized in that: The one sequence upper die assembly includes an upper die plate A, an upper die pad, an upper die middle ring, an upper die outer ring and a guide sleeve; the upper die plate A is connected with the movable cross beam of the press, the upper die pad and the upper die middle ring are arranged in the upper die outer ring, the upper die outer ring is fixed on the lower side of the upper die plate A through bolts, and the guide sleeves are respectively arranged at the four corner positions of the lower side of the upper die plate A; the one sequence upper die is tightly fitted in the upper die middle ring.

4. The contact pin part cold extrusion forming die according to claim 2, characterized in that: The lower concave die floating assembly comprises a lower concave die outer ring, a lower concave die base plate and a floating die plate; a first lower concave die is tightly arranged in the lower concave die outer ring; the lower concave die base plate is arranged in the lower concave die outer ring below the first lower concave die; and the lower concave die outer ring is arranged on the floating die plate through bolts.

5. The contact pin part cold extrusion forming die according to claim 4, characterized in that: The lower die fixed assembly comprises a top piece A, a top piece base, a fixed flange, an elastic washer I, a steel base plate, an elastic washer II, a top rod A, a top piece base A, a lower die plate A, a nitrogen spring, an equal-height bolt and a guide column; the fixed flange is arranged on the lower die plate A; the top piece base A is arranged in the center of the lower end of the fixed flange; the top rod A is arranged in the center of the top piece base A through the upper end step and passes through the lower end of the lower die plate A; the top piece base is arranged on the top piece base A; the top piece A is a rectangular bar structure; the top piece A is arranged on the top piece base and the upper end is arranged in the rectangular through hole in the center of the first lower concave die through the floating die plate and the lower concave die base plate in sequence; the elastic washer I, the steel base plate and the elastic washer II are arranged on the step of the outer edge of the fixed flange from top to bottom in sequence; the nitrogen spring is arranged between the lower die plate A and the floating die plate; the equal-height bolt is arranged on the lower die plate A after passing through the floating die plate; the guide column is arranged on the lower die plate A; the upper end of the guide column is arranged in the guide sleeve on the lower side of the upper die plate in correspondence; and the equal-height bolt and the guide column are arranged in sliding fit with the floating die plate.

6. The contact pin part cold extrusion forming die according to claim 2, characterized in that: The second upper die assembly comprises an upper die plate B, an upper base plate, a connecting flange base plate, a connecting flange, a punch base plate, a punch sleeve and a locking nut; the upper die plate B is connected with the movable cross beam of the press; the upper base plate is arranged between the upper die plate B and the connecting flange; the connecting flange is connected with the upper base plate and the upper die plate through bolts; the outer edge of the lower end of the connecting flange is provided with threads; the punch sleeve and the connecting flange base plate are arranged in the connecting flange through the locking nut; the punch is tightly arranged in the center of the punch sleeve; the punch base plate is arranged in the punch sleeve above the punch; and the lower end of the punch protrudes from the lower end of the punch sleeve.

7. The contact pin part cold extrusion forming die according to claim 2, characterized in that: The lower die assembly comprises a middle die ring, an outer die ring, a die thread compression ring, a top piece B, a die seat, a top piece base B, a die seat base plate, a top rod B, a lower die plate B, a top piece fixing block, a die cylinder and a die cylinder compression ring; the middle die ring is hot-fitted in the outer die ring; the second lower concave die is tightly arranged in the upper part of the middle die ring; the die thread compression ring is arranged in the lower side of the middle die ring through threads; the die seat step part is arranged in the die thread compression ring; the upper end surface of the die seat is in contact with the lower end surface of the second lower concave die; the die seat is arranged on the lower die plate B through the die seat base plate; the top rod B is arranged in the center of the die seat base plate and the lower die plate B; the top piece base B is arranged in the center of the lower end of the die seat; the upper end of the top rod B is in contact with the top piece base B; the top piece B is arranged on the top piece base B through the top piece fixing block; the upper end of the top piece B is arranged in the top piece through hole in the center of the second lower concave die; the die cylinder is arranged on the lower die plate B outside the outer die ring through bolts; and the die cylinder compression ring is arranged on the upper end of the die cylinder through bolts and is arranged on the step of the outer ring of the upper end surface of the outer die ring.

8. The contact pin part cold extrusion forming die according to claim 7, characterized in that: The inner hole of the middle die ring is a stepped conical hole matching the conical structure of the lower die, and a semicircular groove corresponding to the alignment groove on the outer edge of the lower die is arranged on the inner wall of the middle die ring. The alignment groove and the semicircular groove jointly form a pin hole, and the semicircular groove extends upward along the inner wall to the top end of the middle die ring to form a pin dismounting hole.

9. A method of using the contact pin part cold extrusion forming die according to any one of claims 2-8, characterized in that: S1: assembly of the upper die assembly; forcefully press the upper middle die ring into the upper outer die ring, forcefully press the upper die into the upper middle die ring, place the upper die pad on the upper part of the upper middle die ring, connect the upper outer die ring and the upper die plate A through bolts, and press the guide sleeves into the four corner positions of the upper die plate A respectively; S2: assembly of the lower die floating assembly; press the lower die into the lower outer die ring, place the lower die pad on the lower part of the lower outer die ring, and connect the lower outer die ring and the floating die plate through bolts; S3: assembly of the lower die fixed assembly; insert the top rod A into the top piece pad A, insert the assembly into the inner hole of the fixed flange, fix the fixed flange and the lower die plate A through bolts, sequentially insert the elastic washer one, the steel pad, and the elastic washer two onto the steps of the outer edge of the fixed flange, install a plurality of nitrogen spring supports and bolts on the lower die plate A, place the top piece pad into the inner hole of the fixed flange, and press into the lower die plate A respectively; slide connect the lower die floating assembly assembled in step S2 through the guide column, then insert the equal height bolts from the floating die plate into the lower die plate A and tighten, and limit the lower die floating assembly; S4: assembly of the first sequence die; connect the upper die plate A and the movable cross beam of the press through bolts after assembling the assembly in step S1, align the upper die assembly and the lower die floating assembly through the guide column and the guide sleeve, then fix the lower die plate A on the press through bolts after assembling the assembly in step S3, connect the top rod A and the lower ejecting oil cylinder of the press, and ensure that the upper die assembly and the lower die floating assembly are concentric and can be slidably connected; S5: first sequence extrusion forming; when the movable cross beam of the press rises to drive the upper die assembly to move away from the lower die floating assembly by a certain distance, place the round bar blank into the first sequence lower die, then the movable cross beam of the press drives the upper die assembly to press downward, and when the first sequence upper die and the first sequence lower die contact, a radial extrusion cavity is formed, the flow space outlet of the cavity is the waist-shaped through hole at the center of the first sequence upper die, and when the upper die assembly and the lower die floating assembly continue to move downward as a whole, the blank first undergoes upsetting to form a four-sided body, then the material flows out from the flow space outlet to form a middle forging blank with a waist-shaped column; during the radial extrusion, after the lower surface of the floating die plate and the upper surface of the fixed flange are in rigid contact, the elastic washer one, the elastic washer two, and the nitrogen gas spring will generate an upward resistance to the lower die floating assembly, and the lower die floating assembly cannot move downward any more; when the press reaches the set load, the radial extrusion is completed; S6: first sequence return stroke and part taking; After the radial extrusion is completed, the movable cross beam drives a sequence of upper die assembly to move upward, and the nitrogen spring and the elastic washer one and the elastic washer two also drive the lower die floating assembly to move upward under the restoring force, when the floating die plate moves to the upper end limit position of the equal height bolt, it stops, the movable cross beam continues to drive the sequence of upper die assembly to move upward, when it moves to a certain distance, the movable cross beam stops moving; the lower ejector cylinder of the press moves upward, thereby pushing the ejector rod A to move upward, the ejector rod A pushes the ejector pad to move upward, the ejector pad pushes the ejector A to move upward, the ejector A pushes the intermediate forging to move upward, thereby ejecting the forging from the sequence of lower die cavity, and finally taking out the intermediate forging; S7: assembly of the second sequence upper die assembly; The punch core shaft is pressed into the punch, the punch is strongly pressed into the punch sleeve, and the punch gasket plate is placed in the inner hole of the punch sleeve; the upper gasket plate and the connecting flange are placed on the lower side of the upper die plate B and are connected by bolts; the connecting flange gasket plate and the assembled punch sleeve are installed in the connecting flange and fixed by lock nuts; S8: assembly of the lower die assembly; When the outer ring of the female die is heated to 450℃ and the middle ring of the female die is at a temperature of 20-50℃, it is placed in the outer ring of the female die for heat shrinkage fitting; the position corresponding hole of the positioning groove on the outer edge of the second sequence lower die body and the semicircular groove on the inner wall of the middle ring of the female die is formed, and a pin is inserted for positioning, then the split block is inserted into the middle ring of the female die, the second sequence lower die is strongly pressed into the middle ring of the female die, and under the pressure maintaining state, the female die threaded compression ring is screwed into the lower end of the male die middle ring; the die cylinder is installed on the lower die plate B by bolts, and the die seat gasket plate is placed on the center of the lower die plate B; the ejector rod B is inserted into the center hole of the die seat gasket plate and the lower die plate B; the lower end of the ejector B is strongly pressed into the ejector fixed block; the ejector pad B and the ejector B are placed in the center of the die seat gasket plate in turn, and then the die seat is placed outside the ejector pad B, the upper end of the ejector B passes through the die seat, the assembled second sequence lower die is inserted into the ejector B through the center of the ejector hole, and the upper end step of the die seat is located in the inner hole of the female die threaded compression ring; the die cylinder compression ring is placed on the step of the outer ring of the female die upper end and is connected with the die cylinder by bolts; S9: installation of the second sequence die; After the second sequence upper die assembly assembled in step S7 is aligned with the lower die assembly through the punch and the second sequence lower die, the upper die plate B is connected with the movable cross beam of the press, the ejector rod A is connected with the lower ejector cylinder of the press, the lower die assembly is fixed to the press by bolts, and the ejector rod B is connected with the lower ejector cylinder of the press; S9: second sequence extrusion forming The intermediate forging is put into the cavity groove of the second sequence lower die when the movable cross beam of the press drives the second sequence upper die assembly to move upward and leave the lower die assembly by a certain distance, the movable cross beam drives the punch downward, the punch extends into the cavity groove of the second sequence lower die, and the waist boss of the intermediate forging extends into the inner hole of the punch; when the second sequence extrusion stress starts, the lower end surface of the punch is in contact with the large end surface of the intermediate forging, the lower end surface of the punch core shaft is in contact with the upper end surface of the waist column, with the continuous downward movement of the movable cross beam of the press, the punch gradually moves downward through layer-by-layer pressure transmission, the intermediate forging moves downward to produce plastic deformation, and in the extrusion process, the T-shaped connection body, the circular arcs of the connection end a and the connection end c, and the four profile sealing ring grooves are sequentially formed; when the lower surface of the punch sleeve is in rigid contact with the upper surface of the second sequence lower die or when the press reaches the set load, the second sequence upper die assembly cannot move downward any more, and the radial extrusion is completed; S10: second sequence back to take the piece; After the second sequence extrusion is completed, the movable cross beam drives the second sequence upper die assembly to move upward in backstroke, the second sequence upper die assembly is separated from the lower die assembly by a certain distance, and then the movable cross beam of the press stops moving; the lower ejecting oil cylinder of the press moves upward, thereby driving the ejector rod B to move upward, the ejector rod B drives the ejector pad B and the ejector B to move upward, the ejector B drives the second sequence extrusion forging to move upward, thereby ejecting the second sequence extrusion forging from the second sequence lower die and taking it out.

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