Cold forging forming process and die for triangular shaft of clutch

Abstract

The invention discloses a cold forging forming process and die for a triangular shaft of a clutch, and the cold forging forming process comprises the following steps: S1, blanking: straightening a wire rod material, and processing the wire rod material into a bar material longer than the triangular shaft; s2, annealing is conducted; s3, carrying out first surface treatment; s4, first extrusion is conducted, specifically, a floating die with a certain out-of-tolerance range is designed for the triangular shaft according to the shape of the triangular shaft, the bar subjected to first-time surface treatment is put into the floating die, pressure is applied from the two ends so that the bar can be upset to form a hexagon, the bar can extend out of three rectangular clamping positions in the radial direction of the hexagon, and a middle forging stock is formed; s5, carrying out non-oxidation annealing; and S6, carrying out secondary surface treatment. According to the cold forging forming process and the cold forging forming die for the clutch triangular shaft, the characteristic of near-net forming of materials can be utilized, a triangular shaft part which can be matched with a small amount of machining to have very high precision is formed, the material utilization rate can reach 53.4%, the machining time can be saved by at least 50%, and the production cost and the machining efficiency are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal cold forging, in particular to a cold forging forming process and a die for a clutch triangular shaft. Background Art

[0002] The triangular shaft is a component of the clutch, such as Figure 1 As shown, it includes a hexagonal, screw hole inner hole, three rectangular clamping positions and a forming groove. There are mainly two technical solutions for processing triangular shafts in the existing technology: Existing technical solution 1: directly use round bar material to mill to the forging shape of solution 1 through a machining center, and mill or turn off the other end. The material weight requirement is about 525g, and the raw material utilization rate is about 11.8%. The disadvantages of this solution are very low raw material utilization rate, large turning volume, and high raw material and processing costs.

[0003] Existing technical solution 2: After the steel blank is heated to the hot forging temperature of 1100℃, it is extruded forward to extrude the required triangular shaft and the largest cylindrical skin, and then the cylindrical skin part is turned off. The material weight requirement is about 333g, and the raw material utilization rate is about 18%. The disadvantages of this solution are: low raw material utilization rate; the die life of hot reverse extrusion is only one-tenth of the cold extrusion life; low production efficiency; large machining allowance and high processing cost.

[0004] Since the shape of the triangular shaft is rather special and machining the tool is somewhat difficult, it is necessary to propose a cold forging process with high machining accuracy and high material utilization rate. Summary of the invention

[0005] The purpose of the present invention is to propose a cold forging forming process and mold for a clutch triangular shaft, which can utilize the near-net-shape forming characteristics of the material to form a triangular shaft part with very high precision with a small amount of machining. The material utilization rate can reach 53.4%, the processing time can be saved by at least 50%, and the production cost and processing efficiency can be significantly improved.

[0006] The technical solution adopted by the present invention is: a cold forging forming process of a clutch triangular shaft, including a hexagon, a screw hole inner hole in the hexagon, three rectangular clamping positions extending along the radial direction of the hexagon, and a forming groove between the hexagon and the rectangular clamping positions, and the cold forging forming process includes the following steps: S1. Cutting: Straightening the disc round material and processing it into a rod material having a length greater than the triangular shaft; S2, annealing; S3, first surface treatment; S4, Squeeze 1: According to the shape of the triangular shaft, a floating die with a certain tolerance range is designed for it. The bar after the first surface treatment is placed in the floating die, and pressure is applied from both ends to upset the bar into a hexagonal shape, and the bar is extended along the radial direction of the hexagonal shape to form three rectangular positions to form an intermediate forging blank; S5, non-oxidation annealing; S6, second surface treatment; S7, Extrusion 2: According to the shape of the triangular shaft, a finishing die that meets the specified tolerance range is designed for it, and the intermediate forging billet that has undergone the second surface treatment is placed in the finishing die; the intermediate forging billet is compositely extruded, the size of the hexagonal and rectangular clamping positions is trimmed, and the connecting part of the hexagonal and rectangular clamping positions is extruded in the axial direction of the intermediate forging billet, so that the material of the connecting part is transferred to both sides to form a forming groove, and the final forging billet is formed after extrusion; S8, machining: The inner holes of the screw holes are drilled on the hexagon of the final forging billet and turned to the finished product requirements.

[0007] As a preferred solution, during the first surface treatment, 0.8 mm diameter stainless steel shot is used for shot blasting for 20 minutes, and then the film is subjected to phosphorus saponification treatment.

[0008] As a preferred solution, during annealing, the bar is heated to 760°C, kept at this temperature for 4 hours, and then reduced by 15°C per hour. After being reduced to 720°C, it is kept at this temperature for 6 hours, cooled to 500°C in the furnace, and air-cooled after being taken out of the furnace.

[0009] As a preferred solution, during non-oxidative annealing, the intermediate forging billet is first heated to 680°C, kept at this temperature for 3 hours, cooled with the furnace to below 100°C, and then air-cooled out of the furnace.

[0010] A floating die for cold forging of a clutch triangular shaft, the floating die comprising an upper die assembly, a lower die fixed assembly, and an intermediate floating die assembly therebetween; The upper die assembly comprises an upper die plate and an upper punch located on the upper die plate; The middle floating mold assembly includes a middle template and an upper concave mold 1 for forming a rectangular position, a lower concave mold 1 for forming a hexagonal position and a lower mold middle circle floating with the middle template; wherein the upper concave mold 1 and the lower mold middle circle are adjacent to each other up and down, and the adjacent surfaces of the two correspond to one side end surface of the rectangular position, and the lower concave mold 1 is placed in the lower mold middle circle; The lower die fixing assembly includes a lower die plate, a top piece device 1, and an elastic element that provides a floating support force for the intermediate die plate during the extrusion process of the intermediate forging blank; One end of the ejector extends into the lower concave die, and is sealed and combined with the upper punch, the upper concave die, the lower concave die and the lower die middle circle to form a floating molding cavity located inside the floating die.

[0011] As a preferred solution, the upper punch has a protrusion that can extend into the upper die.

[0012] As a preferred solution, a lower template fixing flange is fixed on the lower template, and a ejector fixing flange is slidably arranged inside the lower template fixing flange; the ejector passes through the ejector fixing flange and drives the ejector fixing flange to slide inside the lower template fixing flange during ejection.

[0013] As a preferred solution, the floating supporting force is greater than the force applied to the upper punch by the material of the intermediate forging blank when it is transferred in the floating forming cavity.

[0014] As a preferred solution, the elastic element includes an elastic element 1 which is in a ring shape and is sequentially sleeved on the outer side of the lower template fixing flange, a steel pad and an elastic element 2.

[0015] A finishing die for cold forging of a clutch triangular shaft, the finishing die comprising an upper die mechanism and a lower die mechanism; The upper die mechanism has a convex die; The lower die mechanism comprises an upper die 2 for forming a rectangular position, a lower die 2 for forming a hexagonal position, and a lower die middle circle; the upper die 2 and the lower die middle circle are adjacent to each other, and the adjacent surfaces of the two correspond to one side end surface of the rectangular position, the lower die 2 is located in the lower die middle circle, and an annular boss for forming the molding groove is provided on the end surface of the lower die 2; The lower mold mechanism also has a top piece device 2, one end of which extends into the lower concave mold 2 and is closed and combined with the upper concave mold 2, the lower concave mold 2 and the lower concave mold middle circle to form a finishing molding cavity inside the finishing mold.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. By combining floating extrusion and radial extrusion, the unit pressure is reduced and the mold life is increased.

[0017] 2. Using cold pressing to form, no heating is required, which reduces the process flow; compared with hot reverse extrusion, the mold life is longer; 3. The two-sequence extrusion method is used to change the metal flow mode of forging forming. The second extrusion plays the role of fine-tuning the size and pressing the groove, which can avoid the radial flow of metal in the mold at the forming groove, resulting in a short mold life, and can also reduce the amount of cutting during product forming. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 is a schematic diagram of the triangular axis; Figure 2 It is a schematic diagram of the forming of some processes of the present invention; Figure 3 It is a schematic diagram of the state of the floating mold of the present invention when it is closed; Figure 4 It is a schematic diagram of the state of the floating mold of the present invention when it is opened; Figure 5 It is a schematic diagram of the upper die 1 of the present invention; Figure 6 It is a schematic diagram of the lower concave die 1 of the present invention; Figure 7 It is a schematic diagram of the combination of the lower concave die 1 and the lower die middle ring of the present invention; Figure 8 It is a schematic diagram of the combination of the upper concave die 1, the lower concave die 1, and the lower die middle ring of the present invention; Fig. 9 It is a schematic diagram of the top member 1 in the present invention; Fig.10 It is a schematic diagram of the fixing flange of the ejector in the present invention; Fig.11 Schematic diagram of the upper punch in the present invention; Fig.12 It is a schematic diagram of the finishing mold of the present invention; Fig.13 It is a schematic diagram of a male mold of the present invention; Fig.14 It is a schematic diagram of the male mold sleeve of the present invention; Fig.15 It is a schematic diagram of the punch sleeve and the punch assembly of the present invention; Fig.16 It is a schematic diagram of the second lower concave mold of the present invention; Fig.17 It is a schematic diagram of the middle circle of the concave die of the present invention; Fig.18 It is a schematic diagram of the combination of the lower concave die 2 and the lower concave die middle ring of the present invention; Fig.19 It is a schematic diagram of the second upper concave die of the present invention; Fig. 20 It is a schematic diagram of the combination of the upper concave die 2 and the lower concave die 2 of the present invention; Fig.21This is a schematic diagram of the second outer ring of the lower mold of the present invention; Fig. 22 It is a schematic diagram of the combination of the upper concave die 2, the lower concave die 2 and the lower die outer ring 2 of the present invention.

[0020] Reference numerals: 100, triangular axis; 101, hexagonal; 102, rectangular positioning; 103, forming groove; 200, floating mold; 201, upper template, 202, upper die pad 1, 203, upper punch, 204, upper die outer ring, 205, die middle ring, 206, upper die 1, 207, lower die 1, 208, lower die middle ring, 209, lower die outer ring 1, 210, ejector 1, 211, middle pad, 212, middle template, 213, ejector fixing flange, 214, elastic element 1, 215, steel pad, 216, elastic element 2, 217, ejector pad, 218, lower template fixing flange, 219, ejector pad 2, 220, lower die ejector, 221, lower template, 222, elastic element 3, 223, equal height screw, 224, guide sleeve 1, 225, guide column, 226, guide sleeve 2, 227, floating extrusion forging, 228, bar stock; 300. Finishing mold; 301. Punch block, 302. Punch sleeve, 303. Punch, 304. Upper die (II), 305. Lower die (II), 306. Lower die middle ring, 307. Lower die outer ring (II), 308. Die base, 309. Ejector (II), 310. Pad, 311. Die cylinder pressure plate, 312. Die cylinder, 313. Ejector rod, 314. Upper die pad, 315. Upper die pad (II), 316. Upper die connecting flange, 317. Nut. DETAILED DESCRIPTION

[0021] The present invention is described in detail below by way of exemplary embodiments. However, it should be understood that, without further description, elements, structures and features in one embodiment may also be beneficially combined in other embodiments.

[0022] It should be noted that: unless otherwise defined, the technical terms or scientific terms used in this document shall have the usual meanings understood by people with ordinary skills in the field to which the invention belongs. The words "one", "an" or "the" and the like used in the patent application specification and claims of the present invention do not express quantity restrictions, but indicate the existence of at least one; the words "first", "second" and "third" used in this document shall not be regarded as restrictions on the order of components, but are only used to distinguish different components; words such as "include" or "comprise" and the like indicate that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, but do not exclude other elements or objects with the same function.

[0023] In order to more clearly describe the cold forging process and die of the clutch triangular shaft, Figure 1-22 Describe this embodiment: like Figure 1 and Figure 2 As shown, a cold forging process of a clutch triangular shaft is shown, wherein the triangular shaft 100 is made of 16MnCr5 steel, and comprises a hexagonal portion 101, a screw hole in the hexagonal portion 101, three rectangular positions 102 extending radially along the hexagonal portion 101, and a forming groove 103 between the hexagonal portion 101 and the rectangular positions 102. The cold forging process comprises the following steps: S1. Cutting: Straighten the disc and process it into a bar with a length greater than 100 of the triangular shaft; S2, Annealing: After heating the bar to 760℃, keep the temperature for 4 hours, reduce the temperature by 15℃ every hour, reduce the temperature to 720℃, keep the temperature for 6 hours, cool it to 500℃ with the furnace, and air cool it out of the furnace; The purpose of the first annealing is to convert the raw material structure into a spheroidized structure for easy extrusion molding; because the blank is in an aerobic environment, a thicker oxide scale after annealing will not have any effect; S3, the first surface treatment: use 0.8mm diameter stainless steel shot for 20 minutes, and then perform phosphorus saponification treatment on the film; S4, Squeeze 1: A floating die 200 with a certain tolerance range is designed for the triangular shaft 100 according to its shape, and the bar material after the first surface treatment is placed in the floating die 200, and pressure is applied from both ends to upset the bar material into a hexagonal shape, and the bar material is extended along the radial direction of the hexagonal shape to form three rectangular positions to form an intermediate forging blank; the design dimensional tolerance of the intermediate forging blank is less than 0.1 mm; The purpose of extrusion one is to produce an intermediate state that is very close to the forging target; S5, non-oxidation annealing: First, heat the intermediate forging billet to 680℃, keep it warm for 3 hours, cool it down to below 100℃, and then take it out of the furnace for air cooling; the second annealing is because the material becomes hard after the first extrusion, and if it is extruded without annealing, the extrusion force required is larger. And because it is close to the finished product, it must be annealed without oxidation to reduce the hardness of the forging billet without changing the size; S6. Second surface treatment: Use stainless steel shot with a diameter of 0.5 mm for shot blasting for 5 minutes, polish to remove the burrs on the end surface, use stainless steel shot with a diameter of 0.8 mm for shot blasting for 5-10 minutes, and finally perform phosphorus saponification treatment on the film; S7, Extrusion 2: According to the shape of the triangular shaft 100, a finishing die 300 that meets the specified tolerance range is designed for the triangular shaft 100, and the intermediate forging blank that has undergone the second surface treatment is placed in the finishing die 300; the intermediate forging blank is compositely extruded, the sizes of the hexagonal and rectangular clamping positions are trimmed, and the connecting parts of the hexagonal and rectangular clamping positions are extruded in the axial direction of the intermediate forging blank, so that the material of the connecting parts is transferred to both sides to form a forming groove, and the final forging blank is formed after extrusion; The part of the mold used to form the molding groove is arranged in the finishing mold, the radial flow of the metal material is small, and the mold will not be damaged during the molding process of the molding groove; In the mold design, the die is divided into two parts by upper and lower horizontal division and processed separately. On the one hand, it reduces the difficulty of processing, and on the other hand, it is divided from the fillet to avoid the mold from cracking. S8, machining: The inner holes of the screw holes are drilled on the hexagon of the final forging billet and turned to the finished product requirements.

[0024] See also Figure 3-11 A floating die for cold forging of a clutch triangular shaft, wherein the floating die 200 comprises an upper die assembly, a lower die fixed assembly, and an intermediate floating die assembly therebetween; 1. The upper die assembly consists of an upper die plate 201, an upper die pad 1 202, an upper punch 203, an upper die outer ring 204, and a guide sleeve 226; Assembly sequence of upper mold assembly: (1) Press the upper punch 203 forcefully into the upper die outer ring 204; (2) Place the upper die pad 202 into the upper part of the upper die outer ring 204; (3) Connect the upper die outer ring 204 and the upper die plate 201 with universal hexagon socket bolts; (4) Press the guide sleeves 226 (a total of 4 pieces) into the upper mold plate 201; 2. The middle floating mold assembly consists of: a concave mold middle ring 205, an upper concave mold 206, a lower concave mold 207, a lower mold middle ring 208, a lower mold outer ring 209, a middle pad 211, a middle template 212, and a guide sleeve 224; Assembly sequence of the intermediate floating mold assembly: (1) Press the middle ring 205 of the concave die into the outer ring 209 of the lower die; (2) Press the lower concave die 207 forcefully into the lower die middle ring 208; (3) Press the upper die 206 forcefully into the die middle ring 205; (4) Press the lower die 207 and the lower die center ring 208 assembly into the die center ring 205; (5) Place the middle pad 211 into the lower part of the lower die outer ring 209; (6) The lower die outer ring 209 is connected to the middle die plate 212 by ordinary hexagon socket bolts; (7) Press a total of four guide sleeves 24 into the middle template 212; The main parts are an upper concave die 206 for forming a rectangular position, a lower concave die 207 for forming a hexagonal position, and a lower die middle circle 208, which floats with the middle template 212; the upper concave die 206 and the lower die middle circle 208 are adjacent to each other, and the adjacent surfaces of the two correspond to one side end surface of the rectangular position, and the lower concave die 207 is placed in the lower die middle circle 208; the upper convex die 203 has a protrusion that can extend into the upper concave die 206; 3. The composition of the lower die fixing assembly: ejector 1 210, ejector fixing flange 213, elastic element 1 214, steel pad 215, elastic element 2 216, ejector pad 217, lower die plate fixing flange 218, ejector pad 219, lower die ejector rod 220, lower die plate 221, elastic element 3 222, equal height screws 223, guide pillars 225; Assembly sequence of the lower die fixing assembly: (1) Install the lower mold ejector rod 220 into the ejector backing plate 219, and install the assembly into the lower inner hole of the lower mold fixing flange 218; (2) The lower mold ejector rod 220, the ejector backing plate 219, and the lower mold fixing flange 218 are connected as a component to the lower mold plate 221 by ordinary hexagon socket bolts; (3) Place the elastic element 1 214, the steel backing plate 215, and the elastic element 2 216 in sequence onto the stepped cylinder on the lower template fixing flange 218; (4) The elastic element 3 222 is connected to the lower template 221 through a connecting plate and bolts; (5) The ejector 210 and the ejector fixing flange 213 are connected by interference fit as a component; (6) Place the ejector 210, the ejector fixing flange 213 assembly, and the ejector pad 217 into the inner hole of the lower template fixing flange 218 in sequence; (7) The intermediate floating mold assembly and the lower mold fixed assembly are connected by the sliding fit of the guide pillar 225 and the guide sleeve 24; (8) The intermediate floating mold assembly and the lower mold fixed assembly are limitedly connected by equal height bolts 23; The elastic element is arranged between the middle template 212 and the lower template 221, providing a floating support force for the middle template 212 during the extrusion process of the middle forging blank; the floating support force is greater than the force applied to the upper punch 203 when the material of the middle forging blank is transferred in the floating forming cavity.

[0025] One end of the ejector 210 extends into the lower concave die 207 and is closed and combined with the upper punch 203, the upper concave die 206, the lower concave die 207 and the lower die center ring 208 to form a floating molding cavity inside the floating mold 200.

[0026] The ejector 10 is a slender rod-like part that needs to bear a lot of force during the extrusion process and is prone to bending and breaking in the middle part. Therefore, a guide protection mechanism is set for the ejector 10, and the guide protection mechanism specifically includes: a lower template fixing flange 218 is fixed on the lower template fixing flange 218, and an ejector fixing flange 213 is slidably set in the lower template fixing flange 218; the ejector 210 passes through the ejector fixing flange 213, and drives the ejector fixing flange 213 to slide in the lower template fixing flange 218 during ejection.

[0027] In the above method, the elastic element includes an elastic element 1 214, a steel pad 215 and an elastic element 216 which are annular and are sequentially sleeved on the outside of the lower template fixing flange 218.

[0028] In extrusion 1, the action sequence of the floating extrusion die is: After the upper die assembly and the middle floating die assembly are aligned through the guide column 225 and the guide sleeve 226, it is ensured that the upper die assembly and the middle floating die assembly are concentric and can be slidably connected. The upper die assembly and the movable crossbeam plate of the press are reliably connected through bolts, and the lower die fixing assembly is fixed to the lower template of the press through bolts. The lower die ejector rod 220 is connected to the lower ejection cylinder of the press. The movable crossbeam of the press rises to drive the upper die assembly to move. When it leaves the lower die floating assembly for a certain distance, the round bar blank is placed in the middle floating die. In the concave die of the assembly, the movable crossbeam of the press drives the upper die assembly to press downward. When the upper die outer ring 204 contacts the lower die middle ring 208 and the lower die outer ring 209, a radial extrusion cavity is formed. The outlet of the cavity is the flow space between the upper punch 203, the upper concave die 206 and the lower concave die 207. When the upper die assembly and the intermediate floating die assembly continue to move downward as a whole, the blank is first upset to form a hexagonal column, and then the material flows out from the flow space to form an intermediate forging in the shape of a triangular shaft. When radial extrusion begins, the three prisms of the upper punch 203 will extend into the upper concave die 1 206, the lower end surface of the upper punch 203 contacts the upper end surface of the blank, and the upper end surface of the ejector 1 210 contacts the lower end surface of the blank. As the movable crossbeam of the press continuously moves downward to apply pressure to the upper die assembly, the upper die outer ring 204 pushes the middle floating die assembly downward through layer-by-layer pressure transmission. During the radial extrusion process, the elastic element 1 214, the elastic element 216 and the elastic element 3 222 will have an upward resistance to the middle floating die assembly.

[0029] The upper mold assembly pushes the middle floating mold assembly to gradually move downward until the lower surface of the middle mold plate 12 is in rigid contact with the upper surface of the lower mold plate fixing flange 218. The middle floating mold assembly can no longer move downward. When the press reaches the set load, radial extrusion is completed.

[0030] After the radial extrusion is completed, the movable crossbeam drives the upper die assembly to move upward in the return stroke. At the same time, the elastic element three 222 and the elastic element one 214 and the elastic element two 216 will also push the middle floating die assembly to move upward. When the middle floating die assembly moves to the limit position of the equal height screw 223, the middle floating die assembly will no longer move upward. At this time, the movable crossbeam continues to drive the upper die assembly to move upward. After moving to a certain distance, the movable crossbeam of the press stops moving. The lower ejection cylinder of the press moves upward, thereby pushing the lower die ejector rod 220 to move upward. The lower die ejector rod 220 pushes the ejector pad 217 to move upward. The ejector pad 217 pushes the ejector one 210 and the ejector fixed flange 213 assembly to move upward together. The ejector one 210 pushes the extruded forging to move upward, thereby ejecting the forging out of the concave mold cavity. Finally, the forging is taken out of the concave die to complete a cycle process and complete the radial extrusion process.

[0031] See also Figure 12-22, a finishing die used in a cold forging process of a clutch triangular shaft, the finishing die 300 comprising an upper die mechanism and a lower die mechanism; 1. The upper die mechanism consists of a punch block 301, a punch sleeve 302, a punch 303, an upper die pad 314, an upper die block 2 315, an upper die connecting flange 316, and a nut 317; Assembly sequence of upper die mechanism: (1) Connect the upper die pad 314 and the upper die connecting flange 316 to the press slide; (2) Shrink-fitting the punch 303 and the punch sleeve 302; (3) Place the punch block 301 into the punch sleeve 302; (4) The assembled punch sleeve 302 and upper die pad 2 315 are threadedly connected to the upper die connecting flange 316 through the nut 317 and fixed on the upper slide of the hydraulic press.

[0032] 2. The lower die mechanism consists of: an upper concave die 304, a lower concave die 305, a lower concave die middle ring 306, a lower die outer ring 307, a die base 308, a second ejector 309, a backing plate 310, a die cylinder pressure plate 311, a die cylinder 312, and an ejector rod 313.

[0033] Assembly sequence of the lower die mechanism: (1) Fix the mold cylinder 312 to the lower slide of the machine tool with bolts; (2) Place the backing plate 310 into the mold cylinder 312; (3) Place the ejector pin 313 into the mold cylinder 312 and hang it in the countersunk hole of the backing plate 310; (4) Assemble the mold base 308 and the ejector 309 and place them into the mold cylinder 312; (5) Place the pressed upper concave die 2 304, lower concave die 2 305, lower concave die middle ring 306, and lower die outer ring 2 307 on the die base 308; (6) Place the mold barrel pressing plate 311 on the lower mold outer ring 307, and fix the upper concave mold 304, the lower concave mold 305, the lower concave mold middle ring 306, the lower mold outer ring 307, the mold base 308, the ejector 309, etc. in the mold barrel 312 with bolts; Wherein: the second upper die 4 is used to form a rectangular position, and the second lower die 5 is used to form a hexagonal position; the second upper die 4 and the lower die middle circle 306 are adjacent to each other up and down, and the adjacent surfaces of the two correspond to one side end surface of the rectangular position, the second lower die 5 is located in the lower die middle circle 306, and an annular boss for forming a molding groove is provided on the end surface of the second lower die 5; The lower mold mechanism also has a push rod 313, one end of which extends into the second lower die 5, and is closed and combined with the second upper die 4, the second lower die 5 and the lower die middle ring 306 to form a finishing molding cavity inside the finishing mold 300.

[0034] In extrusion 2, the action sequence of the finishing die is: The upper die mechanism is reliably connected to the movable crossbeam plate of the press through nuts, and has a correct alignment relationship with the lower die mechanism. The lower die mechanism is fixed to the lower die plate of the press through bolts. The movable crossbeam of the press rises to drive the upper die mechanism to move. When it leaves the lower die mechanism for a certain distance, the triangular forging blank of the floating extrusion of extrusion 1 is placed in the die guide position of the upper die 2 304. The movable crossbeam of the press drives the upper die mechanism to press downward. When the punch 303 contacts the upper end face of the first sequence forging, it pushes the first sequence forging to continue to move downward and contact the side wall of the upper die 2 304 to correct the width dimensions of the three rectangular teeth of the forging. The punch 303 continues to move downward, and when the lower end face of the first forging contacts the upper end boss of the lower die 305, the material on both sides of the boss will continue to flow downward to the middle hexagonal position on one side, and the material on the other side will continue to flow to the lower space. When the punch sleeve 302 contacts the end face of the second die 3044, the upper die mechanism of the press will stop moving, and the die cavity will form a forging that has been refined by three rectangular tooth widths and pressed out three grooves.

[0035] The parts not described in detail in the above embodiments are prior art.

[0036] It should be noted that although the present invention is described by the above embodiments, the present invention may also have other various embodiments. Without departing from the spirit and scope of the present invention, it is obvious that those skilled in the art may make various corresponding changes and deformations to the present invention, but these changes and deformations should all fall within the scope of protection of the appended claims of the present invention and their equivalents.

Claims

1. A cold forging process for a clutch triangular shaft, wherein the triangular shaft (100) comprises a hexagon (101), a screw hole in the hexagon (101), three rectangular positions (102) extending radially along the hexagon (101), and a forming groove (103) between the hexagon (101) and the rectangular positions (102), characterized in that: The cold forging process includes the following steps: S1. Cutting: Straightening the disc material and processing it into a rod material having a length greater than the triangular shaft (100); S2, annealing; S3, first surface treatment; S4, Squeeze 1: A floating die (200) with a certain tolerance range is designed for the triangular shaft (100) according to its shape, a bar stock after the first surface treatment is placed in the floating die (200), pressure is applied from both ends to upset the bar stock into a hexagonal shape, and the bar stock is extended along the radial direction of the hexagonal shape to form three rectangular clamping positions, thereby forming an intermediate forging blank; S5, non-oxidation annealing; S6, second surface treatment; S7, Extrusion 2: A finishing die (300) is designed for the triangular shaft (100) according to its shape and within a specified tolerance range, and the intermediate forging blank after the second surface treatment is placed in the finishing die (300); the intermediate forging blank is compositely extruded, the dimensions of the hexagonal and rectangular clamping positions are trimmed, and the connecting portion of the hexagonal and rectangular clamping positions is extruded in the axial direction of the intermediate forging blank so that the material of the connecting portion is transferred to both sides to form a forming groove, and a final forging blank is formed after extrusion; S8, machining: The inner holes of the screw holes are drilled on the hexagon of the final forging billet and turned to the finished product requirements.

2. The cold forging process of the clutch triangular shaft according to claim 1, characterized in that: During the first surface treatment, 0.8 mm diameter stainless steel shot was used for shot blasting for 20 minutes, and then the film was subjected to phosphorus saponification treatment.

3. The cold forging process of the clutch triangular shaft according to claim 1, characterized in that: During annealing, heat the bar to 760℃, keep it warm for 4h, reduce it by 15℃ every hour, reduce it to 720℃, keep it warm for 6h, cool it to 500℃ with the furnace, and air cool it out of the furnace.

4. The cold forging process of the clutch triangular shaft according to claim 1, characterized in that: During non-oxidation annealing, first heat the intermediate forging billet to 680°C, keep it warm for 3 hours, cool it down to below 100°C with the furnace, and then take it out of the furnace for air cooling.

5. A floating die for cold forging of a clutch triangular shaft as claimed in claim 1, characterized in that: The floating mold (200) comprises an upper mold component, a lower mold fixed component, and an intermediate floating mold component located between the upper mold component and the lower mold fixed component; The upper mold assembly comprises an upper mold plate (201) and an upper punch (203) located on the upper mold plate (201); The intermediate floating mold assembly comprises an intermediate template (212), an upper concave mold 1 (206) for forming a rectangular position, a lower concave mold 1 (207) for forming a hexagonal position, and a lower mold center ring (208) that floats with the intermediate template (212); wherein the upper concave mold 1 (206) and the lower mold center ring (208) are adjacent to each other up and down, and the adjacent surfaces of the two correspond to one side end surface of the rectangular position, and the lower concave mold 1 (207) is placed in the lower mold center ring (208); The lower die fixing assembly comprises a lower die plate (221), a first ejector (210), and an elastic element for providing a floating support force for the intermediate die plate (212) during the extrusion process of the intermediate forging blank; One end of the ejector (210) extends into the lower concave die (207), and is closed and combined with the upper convex die (203), the upper concave die (206), the lower concave die (207) and the lower die middle ring (208) to form a floating molding cavity located inside the floating mold (200).

6. The floating mold according to claim 5, characterized in that: The upper convex mold (203) has a protrusion that can extend into the upper concave mold (206).

7. The floating mold according to claim 5, characterized in that: A lower template fixing flange (218) is fixed on the lower template (221), and a ejector fixing flange (213) is slidably arranged inside the lower template fixing flange (218); the ejector 1 (210) passes through the ejector fixing flange (213) and drives the ejector fixing flange (213) to slide inside the lower template fixing flange (218) during ejection.

8. The floating mold according to claim 5, characterized in that: The floating support force is greater than the force applied to the upper punch (203) by the material of the intermediate forging blank when it is transferred in the floating forming cavity.

9. The floating mold according to claim 7, characterized in that: The elastic element comprises an elastic element 1 (214) which is in an annular shape and is sequentially sleeved on the outside of the lower template fixing flange (218), a steel backing plate (215) and an elastic element 2 (216).

10. A finishing die for cold forging of a clutch triangular shaft as claimed in claim 1, characterized in that: The finishing die (300) comprises an upper die mechanism and a lower die mechanism; The upper die mechanism has a punch (303); The lower die mechanism comprises an upper die (304) for forming a rectangular position, a lower die (305) for forming a hexagonal position, and a lower die middle circle (306); the upper die (304) and the lower die middle circle (306) are adjacent to each other, and the adjacent surfaces of the two correspond to one side end surface of the rectangular position, the lower die (305) is located in the lower die middle circle (306), and an annular boss for forming the molding groove is provided on the end surface of the lower die (305); The lower mold mechanism also has a second ejector (309), one end of which extends into the second lower concave mold (305) and is closed and combined with the second upper concave mold (304), the second lower concave mold (305) and the lower concave mold middle ring (306) to form a finishing molding cavity located inside the finishing mold (300).

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