Post-drilling forming device for adjusting screw

Abstract

The utility model discloses a post-drilling forming device of an adjusting screw, and relates to the field of screw cold heading processing, the post-drilling forming device comprises a forming die used for processing the adjusting screw, the forming die comprises a first die, a second die and a third die which are arranged in sequence, the first die performs cold heading on a blank to form a first rough blank, the second die performs cold heading on the first rough blank to form a second rough blank, and the third die performs cold heading on the second rough blank to form a third rough blank. The third die performs cold heading on the second rough blank to form a third rough blank, and the third die is located on the third rough blank. And cold heading forming is conducted multiple times step by step, the position of a small hole formed through heading is accurately positioned in a large hole of the counterbore, and the small hole of the counterbore is machined through subsequent drilling. Flow and deformation of materials can be accurately controlled, deformation is controlled, the situation that the surface size of a product does not conform to form and location tolerance is avoided, and it is guaranteed that the table body, the screw rod and the counterbore meet the forming precision requirement.

Description

TECHNICAL FIELD

[0001] The utility model relates to screw cold heading processing field especially, and it is a kind of rear drilling forming device of adjusting screw. BACKGROUND

[0002] Cold heading is the forging method that the die is used to the metal bar stock at normal temperature and is formed by upsetting (usually local upsetting). It is usually used to manufacture the head of screw, bolt, rivet, etc. It can reduce or replace cutting processing.

[0003] As shown in Figures 9 to 10 The adjusting screw currently exists, and the adjusting screw includes column body, table body and screw rod, the cross section of the column body is circular, the cross section of the table body is octagonal, the table body is internally provided with a counterbore, the counterbore is connected by a large hole and a small hole, the large hole of the counterbore is arranged in the column body, the small hole of the counterbore is arranged in the screw rod, the nominal diameter of the screw rod is smaller than the diameter of the large hole of the counterbore, the edge position of the end face of the screw rod away from the table body is provided with a first bevel, and the end of the table body away from the column body is provided with a rounded edge.

[0004] The small hole of the counterbore is arranged in the screw rod after cold heading, and the outer thread needs to be processed on the outer wall of the screw rod. Since the diameter of the screw rod is small and the small hole of the counterbore and the outer thread need to be processed, the adjusting screw has high requirements for the precision of the counterbore and the structural strength. When the complete counterbore is directly processed by the ejector rod, the deformation of the screw rod wall may not be controlled due to the impact of the ejector rod, which may cause cracking, fracture and high thread error of the screw rod wall.

[0005] Therefore, the purpose of the utility model is to provide a rear drilling forming device of adjusting screw to solve the problems of deformation control, cracking and fracture of parts that may occur when the counterbore is cold headed in place at one time during the cold heading process. UTILITY MODEL CONTENTS

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a rear drilling forming device of adjusting screw, including a forming die for processing the adjusting screw, the adjusting screw includes a column body, a table body and a screw rod connected in sequence, the cross section of the column body is circular, the cross section of the table body is octagonal, the table body is internally provided with a counterbore, the counterbore is connected by a large hole and a small hole, the large hole of the counterbore is arranged in the column body, the small hole of the counterbore is arranged in the screw rod, the nominal diameter of the screw rod is smaller than the diameter of the large hole of the counterbore, the edge position of the end face of the screw rod away from the table body is provided with a first bevel, and the forming die includes a first die, a second die and a third die arranged in sequence.

[0007] The first die expands the one end of the blank to the first rod body, and extrudes the first rod body at both ends to form the first round corner, thereby forming the first rough blank;

[0008] The second die reduces the diameter of the one end of the first rough blank away from the first rod body to the second rod body, expands the diameter of the first rod body to form the third rod body, extrudes the second rod body at the end away from the third rod body to form the second round corner, extrudes the third rod body at the end close to the second rod body to form the third round corner, and extrudes the first pre-upset hole at the center of the end face of the third rod body away from the second rod body to form the second rough blank.

[0009] The third die extrudes the third rod body at the end close to the second rod body to form the pre-upset platform, extrudes the third round corner to form the bottom surface of the pre-upset platform, extrudes the column from the end of the third rod body away from the second rod body, deepens the first pre-upset hole to form the large hole of the counterbore, and extrudes the first pit for positioning the small hole of the counterbore inside the large hole of the counterbore, lengthens the second rod body to form the pre-upset rod, and extrudes the fourth round corner at the edge of the end face of the pre-upset rod away from the pre-upset platform to form the third rough blank.

[0010] Preferably, the first die comprises a first punch and a first main die, the first main die comprises a first die shell and a first die core, the first die core is embedded at one end of the first die shell, a first cavity is formed at the center of the first die core, the first punch comprises a first punch head and a first punch rod, a first punch groove is formed at one end of the first punch head, the first punch rod is arranged in the first punch groove, the first punch rod is coaxially arranged with the first punch groove, the end face of the first punch rod close to the first main die is coplanar with the inner wall of the first punch groove, and the two ends of the first rod body are respectively arranged in the first cavity and the first punch groove.

[0011] Preferably, the second die comprises a second punch and a second main die, the second main die comprises a second die shell and a second die core, the second die core is embedded at one end of the second die shell, a second cavity is formed at the center of the second die core, the second punch comprises a second punch head and a second punch rod, the second punch rod is arranged in the second punch head, the end of the second punch rod away from the second punch head is arranged in the second cavity, a cylindrical body is protruded at the center of the end face of the second punch rod away from the second punch head, the second cavity is provided with a first ring body and a second ring body, the cylindrical body, the first ring body and the second ring body are sequentially arranged, the outer diameter of the second punch rod ≤ the inner diameter of the first ring body < the diameter of the cylindrical body < the diameter of the second punch rod ≤ the outer diameter of the first ring body, and the cross sections of the first ring body and the second ring body are both arc-shaped.

[0012] Preferably, the third die set comprises a third punch and a third main die, the third punch comprises a punch shell, a third punch head, a first forming block, a first slider, a second slider, a first sleeve, a third punch rod, the punch shell is provided with a stepped hole, the first slider and the second slider are sequentially arranged in the stepped hole, the first slider and the second slider are slidingly arranged in the stepped hole, the first forming block is embedded in one end of the third punch head close to the third main die, the first forming block is provided with a forming hole for forming a column and a third punch groove for forming a pre-header at both ends, the third punch rod and the first sleeve are arranged in the first slider and the second slider respectively, one end of the first sleeve penetrates through the third punch head and extends into the forming hole, one end of the third punch rod penetrates through the first sleeve and extends into the third punch groove, and the end face of the third punch rod close to the third main die is a conical surface.

[0013] Preferably, the third main die comprises a third die shell and a third die core, the third die core is embedded in one end of the third die shell, and the third die core is provided with a third cavity at the center position, which is matched with the gap of the screw rod, and the end of the third cavity away from the third punch is chamfered.

[0014] Preferably, the stepped hole comprises a first through hole, a second through hole and a third through hole connected in sequence in the direction towards the third main die, and the diameters of the first through hole, the second through hole and the third through hole decrease in sequence.

[0015] Preferably, the second punch rod is a stepped rod, the stepped rod comprises a first rod body, a second rod body and a third rod body connected in sequence, the diameters of the first rod body, the second rod body and the third rod body decrease in sequence, and the second punch head is provided with a stepped groove matched with the second punch rod.

[0016] Preferably, the forming die further comprises a fourth die set, the first die set, the second die set, the third die set and the fourth die set are sequentially arranged, the fourth die set rounds the edge of the pre-header close to the bottom surface of the pre-header rod, the fourth die set extrudes a first bevel angle by extruding a fourth round angle, and the fourth die set extrudes a second pit for positioning a small hole of a counterbore on one end of the pre-header rod to form a product to be drilled.

[0017] Preferably, the fourth die set comprises a fourth punch and a fourth main die, the fourth main die comprises a fourth die shell, a fourth die core and a fourth ejector rod, the fourth die core is embedded in one end of the fourth die shell, the fourth die core is provided with a fourth cavity at the center position for forming a screw rod, the end of the fourth cavity away from the fourth punch is chamfered, the fourth ejector rod penetrates through the fourth die shell and extends into the fourth cavity, and the end face of the fourth ejector rod close to the fourth punch is provided with a conical body for forming a second pit.

[0018] Preferably, in the post-drilling forming device for the adjusting screw, the fourth punch includes a second forming block, a second sleeve, and a fourth punch rod. The second forming block has a guide hole and a fourth punch groove that are interconnected. One end of the second sleeve is located inside the guide hole. The end of the fourth punch rod near the fourth main mold passes through the second sleeve and extends into the fourth punch groove. The center of one end of the third punch rod and the fourth punch rod are both provided with a cone for forming the first recess. One end of the pre-upsetting table is located inside the fourth cavity, and the other end of the pre-upsetting table is located inside the fourth punch groove.

[0019] The beneficial effects of this invention are as follows: Multiple-step cold forging is used to accurately position the forged small hole inside the large countersunk hole, which is then drilled to create the small countersunk hole. This allows for precise control of material flow and deformation, controlling the amount of deformation to avoid discrepancies between the product's surface dimensions and geometric tolerances, and ensuring that the platform, screw rod, and countersunk hole meet the forming accuracy requirements. Attached Figure Description

[0020] The accompanying drawings further illustrate the present invention, but the embodiments in the drawings do not constitute any limitation on the present invention.

[0021] Figure 1 A schematic diagram of the molding die provided in an embodiment of this utility model. Figure 1 ;

[0022] Figure 2 This is a schematic diagram of the structure of a mold provided in an embodiment of the present utility model;

[0023] Figure 3 This is a schematic diagram of the structure of the two-mode module provided in one embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the three-mode structure provided in one embodiment of the present invention;

[0025] Figure 5 for Figure 1 A schematic diagram of the adjusting screw in the molding die. Figure 1 ;

[0026] Figure 6 A schematic diagram of the molding die provided in an embodiment of this utility model. Figure 2 ;

[0027] Figure 7 This is a schematic diagram of the structure of a four-module according to an embodiment of the present invention;

[0028] Figure 8 for Figure 6 A schematic diagram of the adjusting screw in the molding die. Figure 2 ;

[0029] Figure 9 Structure diagram of the adjusting screw;

[0030] Figure 10 Structure diagram of the adjusting screw.

[0031] 1: first rough blank; 11: first rod body; 12: first fillet; 2: second rough blank; 21: third rod body; 22: second rod body; 23: second fillet; 24: third fillet; 25: first pre-upsetting hole; 3: third rough blank; 31: pre-upsetting platform; 32: pre-upsetting rod; 33: fourth fillet; 4: product to be drilled; 41: fillet edge; 42: first bevel; 431: first recess; 432: second recess; 5: adjusting screw; 51: column body; 52: platform body; 53: screw rod; 54: counterbore; 55: first bevel; 541: large hole; 542: small hole; 61: first punch; 62: first main die; 611: first punch head; 612: first punch rod; 621: first die shell; 622: first die core; 71: second punch; 72: second main die; 711: second punch head; 712: second punch rod; 721: second die shell; 722: second die core; 81: third punch; 82: third main die; 811: punch shell; 812: third punch head; 813: first forming block; 814: first sleeve; 815: third punch rod; 816: first sliding block; 817: second sliding block; 821: third die shell; 822: third die core; 91: fourth punch; 92: fourth main die; 911: second forming block; 912: second sleeve; 913: fourth punch rod; 921: fourth die shell; 922: fourth die core. DETAILED DESCRIPTION

[0032] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0033] It should be noted that in the present application, when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or can have a middle element. When an element is referred to as being "pierced through" another element, it means that it directly penetrates the other element. "Inner" and "outer" refer to the inner and outer contours. "Far" and "near" refer to the far and near relative to a certain component.

[0034] As Figures 1-5The utility model discloses an embodiment provides a kind of rear drilling forming device of adjusting screw, including the forming die for processing adjusting screw, the adjusting screw 5 of the cold heading processing of the forming die includes the cylinder 51, platform body 52 and screw rod 53 connected in sequence, the cross section of the cylinder 51 is circular, the cross section of the platform body 52 is octagon, the inside of the platform body 52 is provided with countersunk hole 54, the countersunk hole 54 is connected by large hole 541 and small hole 542, the large hole 541 of the countersunk hole 54 is threaded in cylinder 51, the small hole 542 of the countersunk hole 54 is threaded in screw rod 53, the nominal diameter of the screw rod 53 is less than the diameter of the large hole 541 of countersunk hole 54, the edge position of the end face of the platform body 52 of the screw rod 53 is equipped with first bevel 5542, the forming die includes one die, two dies and three dies arranged in sequence;

[0035] The one die expands the first rod body 11 at one end of the blank, and simultaneously forms the first round corner 12 by strongly extruding the two ends of the first rod body 11, to form the first rough blank 1;

[0036] The two dies reduce the diameter of the end of the first rough blank 1 away from the first rod body 11 to form the second rod body 22, expand the diameter of the first rod body 11 to form the third rod body 21, strongly extrude the end of the second rod body 22 away from the third rod body 21 to form the second round corner 23, strongly extrude the end of the third rod body 21 close to the second rod body 22 to form the third round corner 24, and the two dies form the first pre-upsetting hole 25 at the center of the end face of the third rod body 21 away from the second rod body 22 to form the second rough blank 2;

[0037] The three dies strongly extrude the end of the third rod body 21 close to the second rod body 22 to form the pre-upsetting platform 31, strongly extrude the third round corner 24 to form the bottom surface of the pre-upsetting platform 31, form the cylinder 51 at the end of the third rod body 21 away from the second rod body 22, form the large hole 541 of the countersunk hole 54 by deepening the first pre-upsetting hole 25, form the first pit 431 for positioning the small hole 542 of the countersunk hole 54 inside the large hole 541 of the countersunk hole 54, form the pre-upsetting rod 32 by lengthening the second rod body 22, strongly extrude the edge position of the end face of the pre-upsetting rod 32 away from the pre-upsetting platform 31 to form the fourth round corner 33, to form the third rough blank 3, and the first pit 431 is conical.

[0038] Preferably, the first die comprises a first punch 61 and a first main die 62, the first main die 62 comprises a first die shell 621 and a first die core 622, the first die core 622 is embedded in one end of the first die shell 621, a first cavity is formed in the center of the first die core 622, the first punch 61 comprises a first punch head 611 and a first punch rod 612, a first punch groove is formed in one end of the first punch head 611, the first punch rod 612 is arranged in the first punch groove, the first punch rod 612 is coaxially arranged with the first punch groove, the end face of the first punch rod 612 close to the first main die 62 is coplanar with the inner wall of the first punch groove, and the two ends of the first rod body 11 are respectively sleeved in the first cavity and the first punch groove.

[0039] Preferably, the second die comprises a second punch 71 and a second main die 72, the second main die 72 comprises a second die shell 721 and a second die core 722, the second die core 722 is embedded in one end of the second die shell 721, a second cavity is formed in the center of the second die core 722, the second punch 71 comprises a second punch head 711 and a second punch rod 712, the second punch rod 712 is arranged in the second punch head 711, one end of the second punch rod 712 away from the second punch head 711 is arranged in the second cavity, a cylindrical body 51 is protruded from the center of the end face of the second punch rod 712 away from the second punch head 711, the second cavity is provided with a first ring body and a second ring body, the cylindrical body 51, the first ring body and the second ring body are arranged in sequence, the outer diameter of the second punch rod 712 is less than the inner diameter of the first ring body, the diameter of the cylindrical body 51 is less than the diameter of the second punch rod 712, and the outer diameter of the first ring body is less than the diameter of the second punch rod 712, the cross section of the first ring body and the second ring body are both arc-shaped.

[0040] Preferably, the third die comprises a third punch 81 and a third main die 82, the third punch 81 comprises a punch shell 811, a third punch head 812, a first forming block 813, a first sliding block 816, a second sliding block 817, a first sleeve 814 and a third punch rod 815, the punch shell 811 is provided with a stepped hole, the first sliding block 816, the second sliding block 817 and the third punch head 812 are arranged in the stepped hole in sequence, the first sliding block 816 and the second sliding block 817 are both slidingly arranged in the stepped hole, the first forming block 813 is embedded in one end of the third punch head 812 close to the third main die 82, the first forming block 813 is provided with a forming hole for forming the cylindrical body 51 and a third punch groove for forming the pre-upset boss 31 at two ends respectively, the first sleeve 814 and the third punch rod 815 are arranged in the first sliding block 816 and the second sliding block 817 respectively, one end of the first sleeve 814 penetrates through the third punch head 812 and extends into the forming hole, one end of the third punch rod 815 penetrates through the first sleeve 814 and extends into the third punch groove, and the end face of the third punch rod 815 close to the third main die 82 is a tapered face.

[0041] Preferably, the third main mold 82 includes a third mold shell 821 and a third mold core 822. The third mold core 822 is embedded at one end of the third mold shell 821. A third cavity with clearance fit with the screw rod 53 is opened at the center of the third mold core 822. The end of the third cavity away from the third punch 81 is rounded.

[0042] Preferably, the stepped hole includes a first through hole, a second through hole, and a third through hole connected sequentially along the direction toward the third main mold 82, wherein the diameters of the first through hole, the second through hole, and the third through hole decrease sequentially.

[0043] Preferably, the second punch 712 is a stepped rod, which includes a first rod 11, a second rod 22 and a third rod 21 connected in sequence, the diameters of the first rod 11, the second rod 22 and the third rod 21 decreasing in sequence, and the second punch 711 is provided with a stepped groove adapted to the second punch 712.

[0044] like Figures 2-8 As shown in the figure, in one embodiment, the forming mold further includes a fourth mold, wherein the first mold, the second mold, the third mold and the fourth mold are arranged in sequence. The fourth mold upsets the edge of the pre-upsetting table 31 near the bottom surface of the pre-upsetting rod 32 to form a rounded edge 41. The fourth mold strongly presses the fourth rounded corner 33 to upset a first oblique angle 5542. The fourth mold upsets the pre-upsetting rod 32 to form a second recess 432 for positioning the countersunk hole 54, forming a product 4 to be drilled. The second recess 432 is conical.

[0045] The four molds include a fourth punch 91 and a fourth main mold 92. The fourth main mold 92 includes a fourth mold shell 921, a fourth mold core 922 and a fourth ejector rod. The fourth mold core 922 is embedded in one end of the fourth mold shell 921. A fourth cavity for forming a screw rod 53 is opened at the center of the fourth mold core 922. The end of the fourth cavity away from the fourth punch 91 is chamfered. The fourth ejector rod passes through the fourth mold shell 921 and extends into the fourth cavity. A cone for forming a second recess 432 is protruding from the end face of the fourth ejector rod near the fourth punch 91.

[0046] The post-drilling forming device for the adjusting screw includes a fourth punch 91 comprising a second forming block 911, a second sleeve 912, and a fourth punch 913. The second forming block 911 has a guide hole and a fourth punch groove that are interconnected. One end of the second sleeve 912 is located inside the guide hole. One end of the fourth punch 913, near the fourth main die 92, passes through the second sleeve 912 and extends into the fourth punch groove. The center of one end of the third punch 815 and the fourth punch 913 is provided with a cone for forming the first recess 431. One end of the pre-upsetting table 31 is located inside the fourth cavity, and the other end of the pre-upsetting table 31 is located inside the fourth punch groove.

[0047] The technical features of the above-described embodiments can be combined in any manner. For the sake of brevity, not all possible combinations are described. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the spirit of the present inventive concept, and these should be considered within the scope of the present disclosure.

Claims

1. A rear counterboring forming device for adjusting a screw, characterized by: The application relates to a forming die for machining an adjusting screw, the adjusting screw comprising a column body, a table body and a screw rod connected in sequence, the cross section of the column body is circular, the cross section of the table body is octagonal, a countersunk hole is arranged in the table body, the countersunk hole is composed of a large hole and a small hole, the large hole of the countersunk hole is arranged in the column body, the small hole of the countersunk hole is arranged in the screw rod, the nominal diameter of the screw rod is smaller than the diameter of the large hole of the countersunk hole, a first inclined angle is arranged at the edge of the end face of the screw rod away from the table body, a round corner is arranged at the end of the table body away from the column body, and the forming die comprises a first die, a second die and a third die arranged in sequence. The first die expands the one end of the blank to form a first rod body, and simultaneously, the two ends of the first rod body are strongly pressed to form a first round corner and a first rough blank. The second die shrinks the end of the first rough blank away from the first rod body to form a second rod body, expands the first rod body to form a third rod body, strongly presses the end of the second rod body away from the third rod body to form a second round corner, strongly presses the end of the third rod body close to the second rod body to form a third round corner, and forms a first pre-upsetting hole in the center of the end face of the third rod body away from the second rod body to form a second rough blank. The third die strongly presses the end of the third rod body close to the second rod body to form a pre-upsetting table, strongly presses the third round corner to form the bottom surface of the pre-upsetting table, forms a column body at the end of the third rod body away from the second rod body, forms a large hole of a countersunk hole by deepening the first pre-upsetting hole, forms a first pit for positioning a small hole of the countersunk hole in the large hole of the countersunk hole, forms a pre-upsetting rod by lengthening the second rod body, strongly presses a fourth round corner at the end of the pre-upsetting rod away from the pre-upsetting table to form a third rough blank.

2. The rear counterbore forming device of claim 1, wherein: The first die comprises a first punch and a first main die, the first main die comprises a first die shell and a first die core, the first die core is embedded at one end of the first die shell, a first cavity is arranged at the center of the first die core, the first punch comprises a first punch head and a first punch rod, a first punch groove is arranged at one end of the first punch head, the first punch rod is arranged in the first punch groove, the first punch rod and the first punch groove are coaxially arranged, the end face of the first punch rod close to the first main die is coplanar with the inner wall of the first punch groove, and the two ends of the first rod body are respectively arranged in the first cavity and the first punch groove.

3. The rear counterbore forming device of claim 1, wherein: The second die comprises a second punch and a second main die, the second main die comprises a second die shell and a second die core, the second die core is embedded at one end of the second die shell, a second cavity is arranged at the center of the second die core, the second punch comprises a second punch head and a second punch rod, the second punch rod is arranged in the second punch head, the end of the second punch rod away from the second punch head is arranged in the second cavity, a cylindrical body is arranged at the center of the end face of the second punch rod away from the second punch head, the second cavity is provided with a first ring body and a second ring body, the cylindrical body, the first ring body and the second ring body are arranged in sequence, the outer diameter of the second punch rod is less than the inner diameter of the first ring body, the diameter of the cylindrical body is less than the diameter of the second punch rod, the diameter of the second punch rod is less than the outer diameter of the first ring body, and the cross sections of the first ring body and the second ring body are both arc-shaped.

4. The rear counterbore forming device of claim 1, wherein: The third die set comprises a third punch and a third main die, the third punch comprises a punch shell, a third punch head, a first forming block, a first slider, a second slider, a first sleeve, and a third punch rod, the punch shell is provided with a stepped hole, the first slider, the second slider, and the third punch head are sequentially arranged in the stepped hole, the first slider and the second slider are slidingly arranged in the stepped hole, the first forming block is embedded in one end of the third punch head close to the third main die, the first forming block is provided with a forming hole for forming a column and a third punch groove for forming a pre-header at two ends respectively, the third punch rod and the first sleeve are arranged in the first slider and the second slider respectively, one end of the first sleeve penetrates through the third punch head and extends into the forming hole, one end of the third punch rod penetrates through the first sleeve and extends into the third punch groove, and the end face of the third punch rod close to the third main die is a conical surface.

5. The rear counterbore forming device of claim 4, wherein: The third main die comprises a third die shell and a third die core, the third die core is embedded in one end of the third die shell, and the third die core is provided with a third cavity at the center position, which is matched with the gap of the screw rod, and the end of the third cavity away from the third punch is chamfered.

6. The rear counterboring forming device for adjusting screw according to claim 4, wherein: The stepped hole comprises a first through hole, a second through hole, and a third through hole connected in sequence in the direction close to the third main die, and the diameters of the first through hole, the second through hole, and the third through hole decrease in sequence.

7. The rear counterboring forming device for adjusting screw according to claim 3, wherein: The second punch rod is a stepped rod, the stepped rod comprises a first rod body, a second rod body, and a third rod body connected in sequence, the diameters of the first rod body, the second rod body, and the third rod body decrease in sequence, and the second punch head is provided with a stepped groove matched with the second punch rod.

8. The rear counterboring forming device for adjusting screw according to claim 4, wherein: The fourth die set comprises a fourth punch and a fourth main die, the fourth main die comprises a fourth die shell, a fourth die core, and a fourth ejector rod, the fourth die core is embedded in one end of the fourth die shell, the fourth die core is provided with a fourth cavity at the center position for forming a screw rod, the end of the fourth cavity away from the fourth punch is chamfered, the fourth ejector rod penetrates through the fourth die shell in sequence and extends into the fourth cavity, and the end face of the fourth ejector rod close to the fourth punch is provided with a conical body for forming a second recess.

9. The rear counterboring forming device of the adjusting screw according to claim 8, characterized in that: The fourth punch comprises a second forming block, a second sleeve, and a fourth punch rod, the second forming block is provided with a guide hole and a fourth punch groove in communication with each other, one end of the second sleeve is arranged in the guide hole, one end of the fourth punch rod penetrates through the second sleeve and extends into the fourth punch groove close to the fourth main die, the center positions of one end of the third punch rod and one end of the fourth punch rod are provided with a conical body for forming a first recess, one end of the pre-header is arranged in the fourth cavity, and the other end of the pre-header is arranged in the fourth punch groove.

10. The rear counterbore forming device of claim 9, wherein: ​

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