CN105618665A - Plastic forming method of draw-hole bolt - Google Patents

Abstract

The invention provides a plastic forming method of a draw-hole bolt and belongs to part cold heading methods. The plastic forming method comprises the steps that firstly, the tail taper and required dimension of a rod part are obtained by squeezing a part blank through a first stamping die (1); secondly, a bottom hole and the required dimension of the rod part are obtained by squeezing the part (2) in the first step through a second stamping die (3); thirdly, the head taper and the required dimension of upsetting depth and pumping depth of the rod part are obtained by squeezing the part (2) in the second step through a third stamping die (4); fourthly, the required dimension for flattening the head portion, drawing down the rod part and further hole drawing is obtained by squeezing the part (2) machined in the third step through a fourth stamping die (5); and fifthly, the head shape is obtained by squeezing the part (2) machined in the fourth step through a fifth stamping die (6). The plastic forming method of the draw-hole bolt has the advantages that the bottom hole is squeezed effectively, the procedures are simple, machining is convenient, the material utilization rate is high, and the service life of the dies is long.

Description

A method for plastic forming of bolts with holes

technical field

The invention belongs to the technical field of part processing technology, and in particular relates to a part cold heading processing method for effectively drawing bottom holes.

Background technique

Chinese patent application No. 201110341854.2 discloses a cold heading forming process for titanium alloy fasteners, which is to first select the titanium material in the coil annealed state with a Brinell hardness less than 100, and use a small pass process during drawing, that is, anneal each time The final deformation is increased by one pass, and the processing amount of each pass is 50% of the processing amount of the previous pass; the drawn coil material is sent to a high-strength multi-station cold heading machine, and is formed by at least two cold headings Made, and the deformation of each cold heading does not exceed 50%. The application of the inventive process can improve work efficiency by 10-15 times, reduce material utilization by 50%, and reduce the overall cost by more than 70%. The titanium fasteners produced by this process are more cost-effective than similar products of stainless steel in terms of economic value, and the application field of this product has been rapidly expanded several times. But its disadvantages are: the process is relatively complicated, there is still room for improvement in material utilization, the range of processed materials is small, and the product has burrs, which affect product quality. Therefore, the process still needs to be improved.

Contents of the invention

Aiming at the problems existing in the above-mentioned prior art, the present invention discloses a plastic forming method for hole-extruding bolts, which is a kind of cold heading of parts with effective extrusion of bottom holes, simple process, convenient processing, high material utilization rate and long mold life. processing methods.

The technical solution adopted by the present invention to solve the problems of the technologies described above is as follows:

A cold heading processing method for a part, which comprises the following steps:

Step 1, obtaining the taper of the tail and the required size of the rod through the extrusion of the part blank by the first stamping die (1);

Step 2, extruding the part (2) of step 1 through the second stamping die (3) to obtain the required dimensions of the bottom hole and the rod;

Step 3, extruding the part (2) of step 2 through the third stamping die (4) to obtain the required dimensions of the taper of the head, the upsetting of the rod portion and the evacuation depth;

Step 4, extruding the part (2) processed in step 3 through the fourth stamping die (5), obtaining the flattening of the head and reducing the diameter of the rod and further drawing holes to reach the required size;

In step five, the part (2) processed in step four is extruded through the fifth stamping die (6) to obtain the shape of the head.

Preferably, the first stamping die (1) comprises an upper die and a lower die (17), and the upper die can move up and down relative to the lower die (17); The rod briquetting block (14), the upper die shell (11) forms a die cavity (12), and the lower die (17) forms a lower die cavity (15) capable of forming the part blank into the size required for tail taper and rod upsetting, The lower die cavity (15) corresponds up and down with the die cavity (12); the stamping rod (13) stretches into the die cavity (12) of the upper die shell (11) from top to bottom and stretches out of the upper die shell (11) The bottom surface can also be pressed into the lower die cavity (15); the top of the stamping rod (13) is connected with the bottom surface of the fixed stamping rod briquetting block (14) of the upper die shell (11); the lower die cavity (15) is vertical Stretch into the ejector pin (16) that can push out the stamped part (2) from the cavity (15) of the lower die, the upper end of the ejector rod (16) is in the cavity (15) of the lower die, and the lower end is in the cavity (15) of the lower die ( 17) under the lower end face.

Preferably, the second stamping die (3) comprises a patrix and a lower die shell (34), and the patrix can move up and down relative to the lower die shell (34); , stamping rod briquetting block (33), the bottom of the upper mold shell (31) forms a die cavity (30-1) that can upset the part blank into a required size, and the stamping rod (32) extends into the die cavity from top to bottom ( 30-1), the upper end is connected with the bottom surface of the stamping rod briquetting block (33) fixed to the upper mold shell (31); the lower mold shell (34) cooperates with the inner mold front core (35) of the upper and lower movable type, and the inner mold The front core (35) forms a lower mold cavity (30-2) capable of extruding the part (2) formed in step 1 into a required size, and the lower mold cavity (30-2) is up and down with the punch cavity (30-1) Corresponding; the inner mold front kernel (35) can move up and down relative to the lower mold shell (34), and the push tube (36) stretches into the lower mold cavity (30-2) of the inner mold front kernel (35) from bottom to top, It can move up and down relative to the cavity (30-2) of the lower die; a stretching punch (39) is assembled in the push tube (36), and the upper end of the stretch punch (39) stretches out from the push tube (36) and is in the In the cavity of the lower mold (30-2), the lower end is fixed on the combined spacer (38-3), the combined spacer (38-3) is fixed on the inner mold spacer (38-1), and the inner mold spacer (38-3) 1) It is fixed on the lower end of the lower mold shell (34); a spring is placed between the upper end surface of the inner mold pad (38-1) and the lower end surface of the inner mold front core (35); the combined pad (38-3) is assembled Three needles (38-2) that can move vertically, the upper plane of the three needles (38-2) is in contact with the lower plane of the push tube (36); the three needles (38-2) can slide up and down through the combined pad (38-3) and stretch out the bottom of lower formwork (34).

Preferably, the 3rd stamping die comprises patrix (4) and lower die shell (44), and patrix (4) can move up and down relative to lower die shell (44); Upper die comprises patrix (41), stamping Rod (42), stamping rod briquetting block (43), the bottom of the upper die shell (41) forms a die cavity (40-1) that can punch the part blank into the size required by the taper of the head, and the stamping rod (42) is from top to bottom Stretch down into the die cavity (40-1), and its upper end passes through the top of the die cavity (40-1) and is connected with the bottom surface of the stamping bar briquetting block (43) fixed to the upper mold shell (41); the lower mold shell (44) form the lower mold cavity (40-2) that can place parts (2) molding, the lower mold cavity (40-2) corresponds to the die cavity (40-1) up and down, the lower mold cavity (40- 2) Stretch into the push tube (47), the push tube (47) can move up and down relative to the lower mold cavity (40-2), the push tube (47) cooperates with the stretching punch (48), and the stretching punch (48 ) upper end stretches out the push tube (47) and is in the cavity of the lower die (40-2), the lower end is fixed on the combined spacer (45), the combined spacer (45) is fixed on the lower mold shell (44), the combined spacer ( The lower plane of 45) is flush with the lower plane of the lower mold shell (44); the combined cushion block (45) cooperates with the three needles (46) that can move up and down, and the upper end of the three needles (46) is aligned with the lower surface of the push tube (47). The plane contacts, and the lower end stretches out of the combined spacer (45).

Preferably, the 4th stamping die comprises upper die (5) and lower die (52), upper die (5) can move up and down relative to lower die (52); Upper die (5) includes upper die shell (51), The bottom of the upper die shell (51) forms a die cavity (50-1) capable of stamping the conical part blank into a cake-shaped head; Cavity (50-2), lower die cavity (50-2) corresponds up and down with die cavity (50-1); Lower die cavity (50-2) stretches into the upper end of push tube (55), push tube ( 55) It can move up and down relative to the concave cavity (50-2) of the lower die. The push tube (55) is equipped with a stretching punch (56), and the upper end of the stretching punch (56) extends out of the push tube (55) and is in the lower position. In the die cavity (50-2), its lower end is fixed on the combination spacer (53), the combination spacer (53) is fixedly matched with the lower mold (52) and the lower plane is flush with the lower plane of the lower mold (52), The combination pad (53) is assembled with three needles (54) that can move up and down, and the upper plane of the three needles (54) contacts the lower plane of the push tube (55); the three needles (54) can slide up and down through the combination pad Block (53) and stretch out the bottom of lower mold (52).

Preferably, the fifth stamping die comprises an upper stamping die (6) and a lower die (65), and the upper stamping die (6) can move up and down relative to the bottom die (65) of the lower part; the upper stamping die (6) comprises a stamping die (61) , the upper trimming die (64) and the locking cover (62) of the part head, the upper trimming die (64) is embedded in the cavity of the locking cover (62), and the locking cover (62) is threadedly fixed on the The bottom end of the die (61), the die (6) forms the channel (60-1) through which the formed product is taken out from the die (61); The lower die cavity (60-2), the lower die cavity (60-2) corresponds to the channel (60-1) up and down; the lower die cavity (60-2) extends into the upper end of the through rod (66), through The lower end of the rod (66) is outside the lower mold (65); the through rod (66) is vertically arranged to eject the stamped part (2) from the cavity (60-2) of the lower die, and the through rod (66 ) slide up and down through the through hole of the lower mold (65) and stretch out the bottom of the lower mold (65).

The bottom mold adopts a combined type, and the depth of each sequence of pumping holes is guaranteed by controlling the stroke of the push tube, so that the bottom hole can be formed at one time.

In order to ensure that the depth of the bottom hole can meet the requirements, the holes are drawn three times to ensure the stability of the bottom hole forming. While ensuring the depth, it also avoids the influence of elastic deformation of the material, making the roundness and diameter of the bottom hole more stable.

The hole is divided into three times, so that the force of the punching needle of the reverse extrusion hole is more uniform, and the service life of the punching needle is improved.

The forming of the head is divided into five steps, and it is based on reducing the extrusion force of each sequence punch while ensuring the coaxiality of the head and the rod of the product.

Compared with the prior art, the present invention has the advantages of adopting five processes, that is, step one, to carry out chamfering and shaping to the blank; step two, drawing holes in the bottom mold; step three, punching die preforming and cooperating with the bottom mold to further draw holes; step 4. Upsetting the punching die, and at the same time, the base die bundles the wire blank and further draws holes to meet the depth requirement; step 5, the die cuts and extrudes the hexagonal shape; thereby gradually changing the appearance of the part to meet the processing requirements, high material utilization rate, material saving, and cost saving . The process of the invention is simple, and the parts only need to be placed in the designated position, and the mold can be processed and formed at one time, the effect can be seen immediately, the adjustability is high, the reject rate is reduced, and the cost is further saved. The invention can effectively remove burrs, the surface of the finished product is smooth and of good quality, and the application effect is good. The invention is a part processing technology with stable hole drawing, high speed and good effect. The concentricity of the processed parts can be guaranteed, the service life of the mold and accessories is relatively high, and the ejection of the mold is also convenient, so it can meet the requirements of cold heading.

Description of drawings

Fig. 1 is the sectional view of the first stamping die of the embodiment of the present invention;

Figure 2 is an exploded view of the structure of Figure 1;

Fig. 3 is an enlarged view of part I in Fig. 2;

Fig. 4 is the sectional view of the second stamping die of the embodiment of the present invention;

Fig. 5 is an exploded view of the structure of Fig. 4;

Fig. 6 is an enlarged view of part II in Fig. 5;

7 is a cross-sectional view of a third stamping die according to an embodiment of the present invention;

Figure 8 is an exploded view of the structure of Figure 7;

Fig. 9 is an enlarged view of part III in Fig. 8;

Fig. 10 is a sectional view of the fourth stamping die of the embodiment of the present invention;

Figure 11 is an exploded view of the structure of Figure 10;

Fig. 12 is an enlarged view of part IV in Fig. 11;

Fig. 13 is a sectional view of the fifth stamping die of the embodiment of the present invention;

Figure 14 is an exploded view of the structure of Figure 13;

Fig. 15 is an enlarged view of part V in Fig. 14;

Fig. 16 is an enlarged view of part VI in Fig. 14 .

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1-16, the plastic forming method of the hole-absorbing bolt in this embodiment is carried out according to the following steps:

Step 1: Extruding the part blank into the bottom mold through the first stamping die 1, forming a chamfer at the bottom of the blank, and obtaining the required size for the taper of the tail and the upsetting of the stem;

Step 2, extruding the part 2 of step 1 through the second stamping die 3 to obtain the upsetting of the part and drawing holes to reach the required size;

Step 3: Extrude and preform the head of part 2 in step 2 through the third stamping die 4. The part is then upset and further drilled to reach the required size to obtain the taper of the head and the upsetting of the rod and the evacuation depth. required size;

Step 4, using the fourth stamping die 5 to flatten the head of the part 2 processed in step 3, reduce the diameter of the rod, and further draw holes to reach the required size;

Step 5, use the fifth stamping die 6 to cut and extrude the head of the part 2 processed in step 4 to obtain the shape of the head, and at the same time cut off the excess waste on the head to obtain the shape and size of the head contour of the part without burrs, that is, complete The entire cold heading process of parts.

The first stamping die 1 comprises an upper die and a lower die 17, and the upper die can move up and down relative to the lower die 17 under the action of a driver. The die cavity 12 and the lower die 17 form a lower die cavity 15 that can form the part blank into a bottom taper and a bar upsetting required size. The lower die cavity 15 corresponds to the die cavity 12 up and down. The stamping rod 13 extends into the die cavity 12 of the upper die shell 11 from top to bottom and extends out of the bottom surface of the upper die shell 11 and can be pressed into the cavity 15 of the lower die 17, while the stamping rod 13 (in the die cavity 12) The top of the top is connected with the bottom surface of the stamping rod briquetting block 14 that the upper die shell 11 is fixed. The ejector pin 16 extending vertically into the cavity 15 of the lower die can push the stamped part 2 out of the cavity 15 of the lower die. under. When the blank part is put into the cavity 15 of the lower die, the stamping rod 13 moves downward under the driving action of the driver, and the upper part of the blank part 2 moves downward under the extrusion of the bottom end surface of the stamping rod 13 and enters the cavity of the lower die. The cavity 15 forms a part 2 with a taper at the tail and an upsetting stem with the required size.

The second stamping die 3 comprises an upper mold and a lower die shell 34, the upper die can move up and down relative to the lower die shell 34 through the action of a driver, and the upper die includes an upper die shell 31, a stamping rod 32, and a stamping rod pressing block 33, on which The bottom of the mold shell 31 forms a die cavity 30-1 that can upset the blank of the part into a required size. The stamping rod 32 extends into the die cavity 30-1 from top to bottom, and its upper end passes through the top hole of the die cavity 30-1. Afterwards, the bottom surface of the stamping rod block 33 that is fixed with the upper die shell 31 is connected. The lower mold shell 34 cooperates with the upper and lower movable inner mold front core 35, and the inner mold front core 35 forms a lower mold cavity 30-2 that can extrude the part 2 formed in step 1 into a required size, and the lower mold cavity 30-2 Corresponding to the die cavity 30-1 up and down. The inner mold front core 35 can move up and down relative to the lower mold shell 34, and the push tube 36 extends into the lower mold cavity 30-2 of the inner mold front core 35 from bottom to top, and it can move up and down relative to the lower mold cavity 30-2 . The stretching punch 39 is assembled in the push tube 36, and the upper end of the stretch punch 39 stretches out from the push tube 36 and is in the cavity 30-2 of the lower die, and the lower end is fixed on the combined cushion block 38-3, and the combined cushion block 38- 3 is fixed on the inner mold cushion block 38-1, and the inner mold cushion block 38-1 is fixed on the lower end of the lower mold shell 34. Load spring between the upper end face of inner mold cushion block 38-1 and the lower end face of inner mold front benevolence 35. Combined spacer 38-3 assembles three pins 38-2, and three pins 38-2 can vertically move, and its upper plane contacts with the lower plane of push tube 36. The three needles 38-2 can slide up and down through the through holes of the combined cushion block 38-3 and stretch out the bottom of the lower formwork 34. The part 2 moves downward under the action of the driver and enters the cavity 30-2 of the lower die to form a part 2 with a bottom hole at the tail and a required size for upsetting the stem.

The front core 35 of the inner mold moves downward relative to the lower mold 34 to the required position after being pressed by the die, and at the same time the spring is compressed, the push tube 36 can move up and down relative to the front core 35 of the inner mold and the stretching punch 39, and the stretching punch 39 It is fixed on the combined cushion block 38-3, the lower plane of the combined cushion block 38-3 is flush with the lower plane of the lower mold shell 34, and the combined cushion block 38-3 cooperates with the three needles 38-2. The lower plane of the inner mold spacer 38-1 is flush with the lower plane of the lower mold shell 34. After the blank parts are put into the punching cavity 30-1 of the upper mold and the cavity 30-2 of the lower mold, the upper mold is driven downward by the driver. Moving, the upper part of the blank part moves downward under the extrusion of the bottom surface of the stamping rod 32 and enters the cavity 30-2 of the lower die to form the part 2 of the required size of the head rod part.

The 3rd stamping die comprises patrix 4 and lower die shell 44, and patrix 4 can move up and down relative to lower die shell 44 by drive member, and upper die comprises patrix 41, stamping rod 42, stamping rod pressing block 43, and The bottom of the die shell 41 forms a die cavity 40-1 capable of stamping the part blank into the size required by the taper of the head. The stamping rod 42 extends into the die cavity 40-1 from top to bottom, and its upper end passes through the top of the die cavity 40-1. The through hole is connected with the bottom surface of the stamping rod pressing block 43 fixed with the upper die shell 41. The lower mold shell 44 forms a lower mold cavity 40-2 capable of placing the part 2 for molding. The lower mold cavity 40-2 corresponds to the punch cavity 40-1 up and down, and the lower mold cavity 40-2 stretches into the push tube 47. The tube 47 can move up and down relative to the cavity 40-2 of the lower die. The push tube 47 cooperates with the stretching punch 48. The upper end of the stretching punch 48 extends out of the push tube 47 and is in the cavity 40-2 of the lower die. The lower end is fixed on the The combined spacer 45 is fixed on the lower formwork 44 , and its lower plane is flush with the lower plane of the lower formwork 44 . Combination spacer 45 cooperates three needles 46, and three needles 46 can move up and down, and its upper end contacts with the lower plane of push tube 47, and the lower end stretches out of combination spacer 45. The three needles 46 can slide up and down through the through holes of the combined cushion block 45 and stretch out the bottom of the lower formwork 44 . The part 2 moves downward under the action of the driver and enters the cavity 40-2 of the lower die to form a part 2 with taper at the head and upsetting of the stem and further hole extraction requirements.

The 4th stamping die comprises upper mold 5 and lower mold 52, and upper mold 5 can move up and down relative to lower mold 52 by driving member, and upper mold 5 comprises upper die shell 51, and the bottom of upper die shell 51 forms the conical parts blank. Die cavity 50-1 for punching the pie-shaped head. The lower die 52 forms a lower die cavity 50-2 capable of placing the part 2 after step three, and the lower die cavity 50-2 corresponds to the die cavity 50-1 up and down. The cavity 50-2 of the lower die extends into the upper end of the push tube 55, and the push tube 55 can move up and down relative to the cavity 50-2 of the lower die. The push tube 55 is equipped with a stretching punch 56 whose upper end protrudes Push tube 55 outside and in lower die cavity 50-2, its lower end is fixed on combined spacer 53, combined spacer 53 is fixedly matched with lower die 52 and its lower plane is flush with the lower plane of lower die 52, combined pad Block 53 fits three needles 54, and three needles 54 can move up and down, and its upper plane contacts with the lower plane of push tube 55. The three needles 54 can slide up and down through the through holes of the combined cushion block 53 and stretch out from the bottom of the lower mold 52 . The part 2 moves downward under the action of the driver and enters the cavity 50-2 of the lower die to form the part 2 with the requirements of flattening the head, upsetting the stem and further drawing holes.

The fifth stamping die comprises an upper stamping die 6 and a lower die 65, and the upper stamping die 6 can move up and down relative to the bottom die 65 of the lower part through a driver. The tight cover 62, the upper trimming die 64 is embedded in the cavity of the locking cover 62, the locking cover 62 is screwed to the bottom of the die 61, and the die 6 forms a channel 60-1 for taking out the formed product from the die 61 . The lower mold 65 forms a lower mold cavity 60-2 that can smoothly enter the parts 2 that have completed step 4, and the lower mold cavity 60-2 corresponds to the channel 60-1 up and down. The lower mold cavity 60-2 extends into the upper end of the through rod (or push rod) 66, and the lower end of the through rod 66 is outside the lower die 65. The through rod 66 is vertically arranged, and it can push out the stamped part 2 from the cavity 60-2 of the lower die. The through rod 66 slides up and down through the through hole of the lower die 65 and stretches out the bottom of the lower die 65. When the upper die 6 moves downward under the drive of the driver, the lower plane of the trimming die 64 contacts the part 2 and impels the part 2 to enter the lower die cavity 60-2 and then starts to extrude, while the through rod 66 vertically pushes up the part 2 , to ensure that the part 2 is separated from the upper mold channel 60-1. Part 2 of step five is formed.

Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, rather than as a limitation to the present invention, as long as within the scope of the present invention, changes and deformations to the above embodiments will fall within the scope of the present invention scope of protection.

Claims (6)

1. A cold heading processing method for parts, characterized in that the steps are as follows: Step 1, obtaining the taper of the tail and the required size of the rod through the extrusion of the part blank by the first stamping die (1); Step 2, extruding the part (2) of step 1 through the second stamping die (3) to obtain the required dimensions of the bottom hole and the rod; Step 3, extruding the part (2) of step 2 through the third stamping die (4) to obtain the required dimensions of the taper of the head, the upsetting of the rod portion and the evacuation depth; Step 4, extruding the part (2) processed in step 3 through the fourth stamping die (5), obtaining the flattening of the head and reducing the diameter of the rod and further drawing holes to reach the required size; In step five, the part (2) processed in step four is extruded through the fifth stamping die (6) to obtain the shape of the head. 2. The cold heading processing method for parts according to claim 1, characterized in that: the first stamping die (1) includes an upper die and a lower die (17), and the upper die can move up and down relative to the lower die (17). Move; the upper die includes an upper die shell (11), a stamping rod (13), and a stamping rod press block (14). The upper die shell (11) forms a die cavity (12), and the lower die (17) forms a The cavity of the lower die (15) is the size required for the taper of the tail and the upsetting of the rod. The cavity of the lower die (15) corresponds to the die cavity (12) up and down; the stamping rod (13) extends into the upper die shell from top to bottom (11) die cavity (12) and stretches out the bottom surface of upper die shell (11) and can be pressed in the lower die cavity (15); The bottom surfaces of the stamping rod briquetting blocks (14) are connected; the lower mold cavity (15) vertically extends into the ejector pin (16) that can push the stamped part (2) out of the lower mold cavity (15), and the ejector pin (16) The upper end is in the cavity (15) of the lower die, and the lower end is under the lower end face of the lower die (17). 3. The part cold heading processing method according to claim 1, characterized in that: the second stamping die (3) comprises an upper die and a lower die shell (34), and the upper die can be moved relative to the lower die shell (34). ) to move up and down; the upper mold includes an upper die shell (31), a stamping rod (32), a stamping rod briquetting block (33), and the bottom of the upper die shell (31) forms a die cavity ( 30-1), the stamping rod (32) stretches into the die cavity (30-1) from top to bottom, and the upper end is connected with the bottom surface of the stamping rod briquetting block (33) fixed to the upper die shell (31); the lower die shell (34) Cooperate with the upper and lower movable inner mold front core (35), the inner mold front core (35) forms a lower mold cavity (30-2) that can extrude the part (2) formed in step 1 into the required size , the lower mold cavity (30-2) corresponds to the punch cavity (30-1) up and down; the inner mold front core (35) can move up and down relative to the lower mold shell (34), and the push tube (36) extends from bottom to top Enter the lower mold cavity (30-2) of the inner mold front core (35), which can move up and down relative to the lower mold cavity (30-2); the stretching punch (39) is assembled in the push tube (36), The upper end of the stretching punch (39) stretches out from the push tube (36) and is in the cavity (30-2) of the lower die, and the lower end is fixed on the combined spacer (38-3), and the combined spacer (38-3) Be fixed on the inner mold pad (38-1), and the inner mold pad (38-1) is fixed on the lower end of the lower mold shell (34); 35) between the lower end faces of springs; the three needles (38-2) that can move vertically are assembled in the combined spacer (38-3), and the upper plane of the three needles (38-2) and the lower surface of the push tube (36) Planar contact; three needles (38-2) can slide up and down through the combination pad (38-3) and stretch out the bottom of the lower formwork (34). 4. The part cold heading processing method according to claim 1, characterized in that: the third stamping die includes an upper die (4) and a lower die shell (44), and the upper die (4) can be moved relative to the lower die The shell (44) moves up and down; the upper mold includes an upper mold shell (41), a stamping rod (42), and a stamping rod pressing block (43). Die cavity (40-1) of required size, stamping rod (42) stretches into the die cavity (40-1) from top to bottom, and its upper end passes through the top of the die cavity (40-1) and connects with the upper die shell (41 ) is connected to the bottom surface of the fixed stamping rod briquetting block (43); the lower mold shell (44) forms a lower mold cavity (40-2) that can place the parts (2) for molding, and the lower mold cavity (40-2) Corresponding to the die cavity (40-1) up and down, the lower die cavity (40-2) extends into the push tube (47), and the push tube (47) can move up and down relative to the lower die cavity (40-2). The tube (47) cooperates with the stretching punch (48), and the upper end of the stretching punch (48) stretches out from the push tube (47) and is in the cavity (40-2) of the lower die, and the lower end is fixed on the combined pad (45), The combination spacer (45) is fixed on the lower formwork (44), and the lower plane of the combination spacer (45) is flush with the lower plane of the lower formwork (44); the combination spacer (45) cooperates with three pins that can move up and down (46), the upper end of three needles (46) contacts with the lower plane of push tube (47), and the lower end stretches out outside the combined spacer (45). 5. The part cold heading processing method according to claim 1, characterized in that: the fourth stamping die includes an upper die (5) and a lower die (52), and the upper die (5) can be moved relative to the lower die ( 52) move up and down; the upper mold (5) includes an upper mold shell (51), and the bottom of the upper mold shell (51) forms a die cavity (50-1) that can stamp the conical part blank into a pie-shaped head; Die (52) forms the lower bottom die cavity (50-2) that can place step 3 rear part (2), and lower die cavity (50-2) corresponds to die cavity (50-1) up and down; The cavity (50-2) stretches into the upper end of the push tube (55), and the push tube (55) can move up and down relative to the cavity (50-2) of the lower die, and the push tube (55) is assembled with a stretching punch (56), The upper end of the drawing punch (56) stretches out the push tube (55) and is in the cavity of the lower die (50-2), and its lower end is fixed on the combined spacer (53), and the combined spacer (53) and the lower die ( 52) fixed fit and the lower plane is flush with the lower plane of the lower die (52), the combined pad (53) is fitted with three needles (54) that can move up and down, and the upper plane of the three needles (54) is aligned with the push tube (55) ) of the lower plane contact; three needles (54) can slide up and down through the combination pad (53) and stretch out the bottom of the lower die (52). 6. The cold heading processing method of parts according to claim 1, characterized in that: the fifth stamping die includes an upper stamping die (6) and a lower die (65), and the upper stamping die (6) can be moved relative to the lower die The bottom mold (65) moves up and down; the upper stamping die (6) includes the punching die (61), the upper trimming die (64) of the part head, and the locking cover (62), and the upper trimming die (64) is embedded in the lock The cavity of the tight cover (62), the locking cover (62) is threadedly fixed on the bottom end of the die (61), and the die (6) forms a passage (60-1) for taking out the formed product from the die (61); The mold (65) forms a lower mold cavity (60-2) that can smoothly enter the parts (2) that have completed step 4, and the lower mold cavity (60-2) corresponds to the channel (60-1) up and down; The die cavity (60-2) stretches into the upper end of the through rod (66), and the lower end of the through rod (66) is outside the lower die (65); ) is ejected from the lower mold cavity (60-2), and the through rod (66) slides up and down through the through hole of the lower mold (65) and stretches out the bottom of the lower mold (65).