CN215786478U

CN215786478U - Heading die for internal multi-tooth bolt

Info

Publication number: CN215786478U
Application number: CN202023284267.8U
Authority: CN
Inventors: 杨立华
Original assignee: Fasteners Branch Co Of Fawer Automotive Parts Co ltd; Fawer Automotive Parts Co Ltd
Current assignee: Fasteners Branch Co Of Fawer Automotive Parts Co ltd; Fawer Automotive Parts Co Ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2022-02-11
Anticipated expiration: 2030-12-30

Abstract

The application relates to the technical field of cold heading forming, in particular to an upset head die for an internal multi-tooth bolt, which comprises a die main body part, an upset head component and a positioning component, wherein part of the upset head component is embedded at one end of the die main body part; the positioning member penetrates through the upset member, one end of the positioning member penetrates through the upset member and abuts against the die main body part through the elastic assembly, and the other end, opposite to the positioning member, of the positioning member penetrates through the upset member and extends to the outside of the upset member; the positioning member is locked on the main body part of the mould through a locking piece embedded in the main body part of the mould; the upset member is movable along the length of the locating member to perform an upset operation on the slug. It can be seen that this mould can accomplish the operation of pier nose alone, separates the operation of backward extrusion and upset among the prior art mutually and provides probably, in addition, utilizes the retaining member to lock locating component in mould main part in this application, and then can guarantee the locating component irrotational, can realize quick location, quick shaping.

Description

Heading die for internal multi-tooth bolt

Technical Field

The application relates to the technical field of cold heading forming, in particular to an upset head die for an inner multi-tooth bolt.

Background

In the current step of forming the internal multi-tooth bolt, after a pit is preformed at the head part of a three-station, the operations of back extruding the inner multi-angle of the bolt and heading are generally completed in a four-station, so that a final product is formed. Regarding the reverse-extrusion inner preset angle of the bolt blank 3 ' in the four-station by using the four-station forming die as shown in fig. 1, and simultaneously performing the operation of heading (wherein the four-station forming die comprises the punch 1 ' and the punch 2 '), however, the above process has the following problems:

firstly, for products which are multi-tooth in the inner and have a deeper and thin wall and a larger and thin head diameter, the metal flow is limited during upsetting, so that the punch 1' is subjected to larger extrusion force in the transverse direction and the longitudinal direction, the service life is sharply reduced, and the average service life in the existing production is less than 500 pieces; secondly, the head is gradually formed in the backward extrusion process, when the backward extrusion positioning member punch 1' works to a certain depth, a metal deformation dead zone is easily formed at the position R below the head, and due to the thin-wall part, if the inner angle depth is continuously deepened, the continuity of a metal streamline at the position of the thin-wall part below the head is easily damaged, and further the risk of part turning around occurs.

In order to solve the problems, the heading and the backward extrusion operation need to be separated, and the blank is required to keep the orientation unchanged in the backward extrusion and heading operations, so that the orientation of the positioning member of the four-station and five-station dies needs to be kept unchanged, and therefore a die which cannot be subjected to extrusion forming when heading forming and has the position of the positioning member unchanged in the heading operation is urgently needed.

SUMMERY OF THE UTILITY MODEL

The application aims to provide an upset head die for an inner multi-tooth bolt, and solves the technical problems that extrusion forming cannot be carried out when an upset head is urgently needed in the prior art and the position of a positioning component is not changed in upset head operation.

The application provides an interior multi-tooth bolt's button head mould includes: a die body, a heading member, and a positioning member;

wherein, the part structure of the heading member is embedded at one end of the main body part of the die; the positioning member penetrates through the upset member, one end of the positioning member penetrates through the upset member and abuts against the die main body part through an elastic assembly, and the other opposite end of the positioning member penetrates through the upset member and extends to the outside of the upset member;

the positioning member is locked on the mould main body part; the upset member is movable along the length of the locating member to effect an upset operation on the slug, and the spring assembly is capable of urging the locating member towards the slug a predetermined distance prior to forming the upset on the slug.

Preferably, the mold main body part comprises a guide bearing member, the guide bearing member is provided with a first mounting cavity, a second mounting cavity and a third mounting cavity, the first mounting cavity, the second mounting cavity and the third mounting cavity are communicated in sequence, the first mounting cavity penetrates through one end of the guide bearing member, and the third mounting cavity penetrates through the opposite other end of the guide bearing member;

part of the structure of the upset head member is inserted into the third mounting cavity, and part of the structure of the positioning member is inserted into the second mounting cavity; the guide bearing member is also provided with a first mounting hole, the second mounting cavity is communicated with the outside through the first mounting hole, a locking piece is arranged in the first mounting hole, and the side wall of the first mounting hole is in threaded connection with the locking piece; the end of the retaining member is compressed against the side wall of the positioning member.

Preferably, the mold main body further comprises a first stopper member and a mounting member, the first stopper member and the mounting member are sequentially disposed in the second mounting cavity, and the first stopper member is disposed close to the positioning member;

the first limiting member is provided with a second mounting hole, the second mounting hole penetrates through two sides of the first limiting member, an elastic assembly is arranged in the second mounting hole, and before blank heading forming, the elastic assembly pushes the positioning member, so that the positioning member leaves a preset distance relative to the end part, close to the first mounting cavity, of the second mounting cavity.

Preferably, the elastic assembly comprises an elastic member, a force application member and a second limit member; wherein the elastic member is disposed in the second mounting hole;

the first limiting member is provided with a third mounting hole, the third mounting hole penetrates through the side wall of the first limiting member, and the second limiting member is inserted into the third mounting hole; the second stopper member, the elastic member, the urging member, and the positioning member are arranged to abut in order along a longitudinal direction of the positioning member;

and before the upsetting of the slug is formed, the force application member pushes the positioning member so that the positioning member is separated from the end part, close to the first mounting cavity, of the second mounting cavity by a preset distance.

Preferably, the elastic member is a spring, and the second limit member is a catch pin.

Preferably, the side wall of the upset head component is formed with a limiting groove, the inner side wall of the guide bearing component facing the side wall of the upset head component is provided with a third limiting component, and the third limiting component is arranged in the limiting groove; said upset member being movable along the length of said locating member between a first extreme position and a second extreme position;

when the upset member moves to a first limit position, a first side wall of the limit groove of the upset member abuts against the third limit member, and when the upset member moves to a second limit position, a second side wall of the limit groove, opposite to the first side wall, abuts against the third limit member.

Preferably, the upset member includes a first mounting portion, a second mounting portion and a forming portion;

the first mounting part is connected with the second mounting part, the forming part is embedded in the second mounting part, and the forming surface of the second mounting part is exposed out of the second mounting part; the first installation part is inserted in the first installation cavity of the guide bearing component, the second installation part is located outside the first installation cavity, and the projection of the second installation part along the length direction of the positioning component covers the opening of the first installation cavity.

Preferably, a safety clearance exists between said guide carriage member and said second mounting portion when said upset member is moved toward the blank to said first limit position.

Preferably, the mold main body further comprises a pushing member and a discharging member;

wherein the mounting member is formed with a guide cavity penetrating both ends of the mounting member, the guide cavity accommodates a partial structure of the pushing member, and the partial structure of the pushing member is movable along the guide cavity;

the discharging member is arranged in the guide bearing member in a penetrating way, one end part of the discharging member can be abutted against the upset head member, and the other opposite end part of the discharging member extends into the guide cavity of the mounting member; the pushing member can push the discharging member so that the discharging member moves along the longitudinal direction of the positioning member.

Preferably, at least one lateral wall of the guide bearing component is provided with a limiting groove.

Compared with the prior art, the beneficial effect of this application is:

the application provides an operation that interior multiple tooth bolt's heading mould can accomplish the pier nose alone, for separating the operation of backward extrusion and heading among the prior art mutually provides probably, the locating component in the fifth station only plays the supporting role, and the atress is less, and then has avoided the risk of turning around that arouses when deep-drawing hole portion of blank, and the problem of rupture can not appear because of the effort that backward extrudees and heading produced simultaneously to the locating component moreover. In addition, because the orientation of the four-station positioning member and the five-station positioning member is kept consistent when the blank is transferred, namely, the positioning member is not rotated, the positioning member is locked on the main body part of the die by utilizing the locking member in the application, and then the positioning member is enabled not to be rotated, so that the rapid positioning and rapid forming can be realized, namely, the possibility of separating the backward extrusion and heading process in the prior art is provided, and meanwhile, the possibility of realizing continuous production is also provided.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic structural view of a four-station punch provided in the prior art;

FIG. 2 is a schematic diagram illustrating the operation of an upset head die for an inner multi-tooth bolt provided in an embodiment of the present application;

FIG. 3 is an exploded view of a part of the structure of an upset head die of an inner multi-tooth bolt provided by an embodiment of the application;

fig. 4 is a schematic structural view of a part of an upset head die of an inner multi-tooth bolt provided in an embodiment of the present application before a blank to be formed is formed;

fig. 5 is a schematic partial structural view of a heading die for an inner multi-tooth bolt provided in an embodiment of the present application in a process of forming a blank to be formed; fig. 6 is a schematic structural diagram of a guide bearing member according to an embodiment of the present application.

Reference numerals:

1 ' -punch, 2 ' -punch, 3 ' -bolt blank;

1-a mold body part, 11-a guide bearing member, 111-a first mounting cavity, 112-a second mounting cavity, 113-a third mounting cavity, 114-a first mounting hole, 115-a limiting groove, 12-a first limiting member, 121-a second mounting hole, 122-a third mounting hole, 13-a mounting member, 14-an elastic component, 141-an elastic member, 142-a force application member, 1421-an abutting part, 1422-a force application part, 143-a second limiting member, 15-a third limiting member, 16-a pushing member, 17-a discharging member, 2-a positioning member, 3-an upset member, 31-a first mounting part, 32-a second mounting part, 33-a forming part, 34-a limiting groove, 4-a locking member, and 5-blank.

Detailed Description

The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, devices, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and/or systems described herein will be apparent to those skilled in the art in view of the disclosure of the present application. For example, the order of operations described herein is merely an example, which is not limited to the order set forth herein, but rather, variations may be made in addition to operations which must occur in a particular order, which will be apparent upon understanding the disclosure of the present application. Moreover, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and/or systems described herein that will be apparent after understanding the disclosure of the present application.

Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on," "connected to," coupled to, "over," or "overlying" another element, it may be directly "on," "connected to," coupled to, "over," or "overlying" the other element, or one or more other elements may be present therebetween. In contrast, when an element is referred to as being "directly on," "directly connected to," directly coupled to, "directly over" or "directly overlying" another element, there may be no intervening elements present.

As used herein, the term "and/or" includes any one of the associated listed items and any combination of any two or more of the items.

Although terms such as "first", "second", and "third" may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section referred to in the examples described herein may be termed a second element, component, region, layer or section without departing from the teachings of the examples.

For ease of description, spatial relationship terms such as "above … …," "upper," "below … …," and "lower" may be used herein to describe one element's relationship to another element as illustrated in the figures. Such spatial relationship terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" relative to other elements would then be oriented "below" or "lower" relative to the other elements. Thus, the term "above … …" includes both an orientation of "above … …" and "below … …" depending on the spatial orientation of the device. The device may also be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative terms used herein should be interpreted accordingly.

The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The singular forms also are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, quantities, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and/or combinations thereof.

Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, may be expected. Thus, the examples described herein are not limited to the particular shapes shown in the drawings, but include changes in shape that occur during manufacturing.

The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. Further, while the examples described herein have a variety of configurations, other configurations are possible, as will be apparent after understanding the disclosure of the present application.

An upset head die for an inner multi-tooth bolt according to some embodiments of the present application is described below with reference to fig. 2-5.

Referring to fig. 2, an embodiment of the present application provides an upset head die for an internal multi-tooth bolt, including: a die body 1, a locating member 2 (i.e., a punch), and a heading member 3 (i.e., a punch);

wherein, the part structure of the heading component 3 is embedded at one end of the main body part 1 of the die; the positioning member 2 is arranged in the upset member 3 in a penetrating manner, one end of the positioning member 2 penetrates through the upset member 3 and abuts against the die main body part 1 through the elastic assembly 14, and the other opposite end of the positioning member 2 penetrates through the upset member 3 and extends to the outside of the upset member 3;

the positioning member 2 is locked to the main mold body 1 by a locking member 4 embedded in the main mold body 1; the upset member 3 is movable along the length of the locating member 2 to effect an upset operation on the slug 5 and the spring assembly 14 is operable to urge the locating member 2 towards the slug 5 a predetermined distance prior to upsetting the slug 5.

The upsetting operation of the upsetting die for the inner multi-tooth bolt comprises the following steps:

the blank 5 is conveyed to a fifth station after the inner corner of the bolt is reversely extruded, an upset head die of the multi-tooth bolt in the fifth station is aligned by utilizing the multiple teeth of the positioning member 2 and extends into the inner corner of the bolt formed in the four stations for positioning, and then the upset head of the blank 5 is carried out by the upset head member 3.

It can be seen that the heading die of the internal multi-tooth bolt can independently complete the heading operation, so that the backward extrusion and heading operation in the prior art can be separated from each other, the positioning member 2 in the fifth station only plays a supporting role and is stressed less, the turning risk caused by deep hole drawing of the blank 5 can be avoided, and the problem that the positioning member 2 is broken due to the acting force generated by the backward extrusion and the heading at the same time can be solved. In addition, the positioning member 2 has slight floating under the action of the elastic component 14, so that the distance of a concave pit formed by the blank 5 through four processes can be offset, and the impact force of the positioning member 2 on teeth is buffered, thereby further preventing the positioning member 2 from being broken.

Wherein, because the drift of quadruplex position and the drift of five stations must keep the direction unanimous promptly not take place the rotation, therefore in this application, lock locating component 2 in mould main part 1 through retaining member 4 to can guarantee that locating component 2 does not take place rotatoryly, so can realize quick shaping and quick location, this can realize: the backward extrusion and heading processes involved in the prior art are separated, and continuous production can be realized at the same time.

In this embodiment, as shown in fig. 2 and fig. 6, the mold main body portion 1 includes a guiding bearing member 11, the guiding bearing member 11 is provided with a first mounting cavity 111, a second mounting cavity 112 and a third mounting cavity 113, wherein the first mounting cavity 111, the second mounting cavity 112 and the third mounting cavity 113 are sequentially communicated, the first mounting cavity 111 penetrates through one end of the guiding bearing member 11, and the third mounting cavity 113 penetrates through the opposite end of the guiding bearing member 11;

part of the structure of the upset head member 3 is inserted in the third mounting cavity 113, and part of the structure of the positioning member 2 is inserted in the second mounting cavity 112; the guide bearing member 11 is further provided with a first mounting hole 114, the second mounting cavity 112 is communicated with the outside through the first mounting hole 114, the locking member 4 is arranged in the first mounting hole 114, and the side wall of the first mounting hole 114 is in threaded connection with the locking member 4; the end of the locking member 4 is pressed against the side wall of the positioning member 2.

According to the structure described above, it is possible to assemble the positioning member 2 and the guide bearing member 11 such that the positioning member 2 and the guide bearing member 11 are fixed relative to each other, and the positioning member 2 does not rotate in the circumferential direction, so that the requirements of actual production are met.

In this embodiment, preferably, as shown in fig. 2 and 3, the mold main body portion 1 further includes a first stopper member 12 and a mounting member 13, wherein both the first stopper member 12 and the mounting member 13 are disposed in the second mounting cavity 112 in sequence with each other, and the first stopper member 12 is disposed close to the positioning member 2;

the first limiting member 12 is provided with a second mounting hole 121, the second mounting hole 121 penetrates through two sides of the first limiting member 12, an elastic assembly 14 is arranged in the second mounting hole 121, and before upsetting of the slug 5 is formed, the elastic assembly 14 pushes the positioning member 2, so that the positioning member 2 is away from the end part, close to the first mounting cavity 111, of the second mounting cavity 112 by a predetermined distance a, that is, the predetermined distance a is formed between the positioning member 2 and the first limiting member 12.

According to the structure described above, the positioning member 2 has slight floating under the action of the elastic component 14, which can offset the distance of the concave pits formed by the four processes of the blank 5, and also buffer the impact force of the positioning member 2 on the teeth, thereby avoiding the breakage of the positioning member 2.

Further, in the embodiment according to the present application, as shown in fig. 1 to 4, the elastic assembly 14 includes an elastic member 141, a force application member 142, and a second stopper member 143; wherein, the elastic member 141 is disposed in the second mounting hole 121;

the first limiting member 12 is provided with a third mounting hole 122, the third mounting hole 122 penetrates through the side wall of the first limiting member 12, and the second limiting member 143 is inserted into the third mounting hole 122; the second stopper member 143, the elastic member 141, the urging member 142, and the positioning member 2 are sequentially abutted along the longitudinal direction of the positioning member 2;

and before upsetting the slug 5, the urging member 142 urges the positioning member 2 so that the positioning member 2 is spaced apart from the end of the second mounting chamber 112 close to the first mounting chamber 111 by a predetermined distance.

In addition, the positioning member 2 slightly floats under the action of the elastic member 141 and the force application member 142, so that the distance of a concave pit formed by the four processes of the blank 5 can be offset, and the impact force of the positioning member 2 on teeth is buffered, so that the positioning member 2 is prevented from being broken.

The force application member 142 has a T-shaped structure, the force application member 142 includes a contact portion 1421 and a force application portion 1422, and correspondingly, the second mounting hole 121 includes a first mounting hole portion and a second mounting hole portion, where the first mounting hole portion and the second mounting hole portion are communicated with each other, the diameter of the first mounting hole portion is greater than that of the second mounting hole portion, the elastic member 141 and the force application member 142 are disposed in the first mounting hole portion, the contact portion 1421 of the force application member 142 contacts with the sidewall of the first mounting hole portion to limit the force application member 142, and the force application portion 1422 of the force application member 142 is inserted into the second mounting hole portion.

In the embodiment according to the present application, the second limiting member 143 abuts against the elastic member 141, and limits the elastic member 141.

As shown in fig. 1 to 4, the elastic member 141 is preferably a spring, which is low in cost and convenient to process or purchase;

the second position-limiting member 143 may be a stop pin, which can abut against the elastic member 141 and limit the position of the elastic member 141.

In this embodiment, preferably, as shown in fig. 2 and 4, the side wall of the upset member 3 is formed with a stopper groove 34, the inner side wall of the guide bearing member 11 is provided with a third stopper member 15, and the third stopper member 15 can be placed in the stopper groove 34.

In an embodiment, for example, the upset member 3 may reciprocate along the length of the locating member 2 between a first extreme position and a second extreme position;

wherein, when the upset member 3 moves to the first limit position, the first side wall of the limit slot 34 of the upset member 3 abuts against the third limit member 15;

when the upset member 3 moves to the second limit position, the second side wall of the retaining groove 34 facing the first side wall abuts the third retaining member 15.

According to the structure described above, the heading member 3 can move in the working range, and the heading member 3 is prevented from coming out of the installation cavity of the guide bearing member 11, so that the controllability is enhanced, and the safety and reliability are improved.

In this embodiment, preferably, as shown in fig. 2, the upset member 3 includes a first mounting portion 31, a second mounting portion 32 and a forming portion 33;

the first mounting portion 31 and the second mounting portion 32 are connected to each other, the forming portion 33 is embedded in the second mounting portion 32, and the forming surface of the second mounting portion 32 is exposed out of the second mounting portion 32;

the first mounting portion 31 is inserted into the first mounting cavity 111 of the guide bearing member 11, the second mounting portion 32 is located outside the first mounting cavity 111, and a projection of the second mounting portion 32 along the length direction of the positioning member 2 covers an opening of the first mounting cavity 111.

When the upset member 3 moves towards the blank 5 to the first limit position, a safety clearance exists between the second mounting portion 32 and the guide bearing member 11, so that the second support guide portion is prevented from colliding with the guide bearing member 11, and the safety and reliability are improved.

As is apparent from the above-described structure, the forming portion 33 is used for upsetting the slug 5, and both the first mounting portion 31 and the second mounting portion 32 can support the forming portion 33.

Further, the first and second mounting portions 31 and 32 each function to support the positioning member 2 and guide the positioning member 2.

In this embodiment, preferably, as shown in fig. 2, the mold main body portion 1 further includes a guide member, a member for discharging 17, and a member for pushing 16.

In an embodiment, the mounting member 13 may be formed with a guide cavity penetrating both ends of the mounting member 13, wherein the guide cavity may accommodate a partial structure of the pushing member 16, and the partial structure of the pushing member 16 may be movable along the guide cavity.

Further, in the embodiment, the discharging member 17 is inserted into the guide bearing member 11, and one end portion of this discharging member 17 can abut against the upset member 3, and the other end portion of the discharging member 17 extends into the guide cavity of the mounting member 13; the pushing member 16 can push the discharging member 17 so that the discharging member 17 moves along the longitudinal direction of the positioning member 2.

According to the structure described above, in the discharging step, the pushing member 16 sequentially pushes the discharging member 17 and the heading member 3 to move toward the slug 5, and the heading member 3 finally pushes the slug 5 to separate from the positioning member 2, so that discharging is realized.

In this embodiment, preferably, as shown in fig. 6, the one-sided outer side wall of the guide bearing member 11 may further form a stopper groove 115.

According to the structure described above, the heading die of the inner multi-tooth bolt is fixed in the die mounting seat through the limiting groove 34, the stability of unilateral positioning is high, unstable factors cannot be additionally increased, and in addition, the structure of the die with five stations is more complex, and the unilateral positioning is adopted, so that the deterioration can be reduced.

Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present application, and are used for illustrating the technical solutions of the present application, but not limiting the same, and the scope of the present application is not limited thereto, and although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope disclosed in the present application; such modifications, changes or substitutions do not depart from the spirit and scope of the exemplary embodiments of the present application, and are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An upset head die for an inner multi-tooth bolt, comprising: a die body, a heading member, and a positioning member;

2. The heading die for an inner multi-tooth bolt according to claim 1, wherein the die body portion comprises a guide bearing member, the guide bearing member is provided with a first mounting cavity, a second mounting cavity and a third mounting cavity, the first mounting cavity, the second mounting cavity and the third mounting cavity are sequentially communicated, the first mounting cavity penetrates through one end of the guide bearing member, and the third mounting cavity penetrates through the other opposite end of the guide bearing member;

3. The upset die for an inner multi-tooth bolt according to claim 2, wherein the die body further includes a first stop member and a mounting member, the first stop member and the mounting member being disposed in series in the second mounting cavity, and the first stop member being disposed adjacent to the locating member;

the first limiting member is provided with a second mounting hole, the second mounting hole penetrates through two sides of the first limiting member, the elastic assembly is arranged in the second mounting hole, and the elastic assembly can push the positioning member to move towards the blank by a preset distance before the blank heading is formed.

4. The upset die for an inner multi-tooth bolt according to claim 3, wherein the resilient assembly includes a resilient member, a force applying member and a second stop member; wherein the elastic member is disposed in the second mounting hole;

5. The upset die for an inner multi-tooth bolt according to claim 4, wherein the resilient member is a spring and the second stop member is a stop pin.

6. The upset die for an inner multi-tooth bolt as claimed in claim 2, wherein the side wall of the upset member is formed with a limiting groove, and the inner side wall of the guide bearing member facing the side wall of the upset member is provided with a third limiting member disposed in the limiting groove; said upset member being movable along the length of said locating member between a first extreme position and a second extreme position;

7. The upset die for an inner multi-tooth bolt according to claim 2, wherein the upset member includes a first mounting portion, a second mounting portion, and a forming portion;

8. The upset die for an inner multi-tooth bolt according to claim 7, wherein a safety clearance exists between the pilot carrier and the second mounting portion when the upset member is moved toward the slug to the first limit position.

9. The upset die for an inner multi-tooth bolt according to claim 3, wherein the die body further includes a pushing member and a discharging member;

10. The upset head die for an inner multi-tooth bolt according to any one of claims 2 to 9, wherein at least one side outer side wall of the guide bearing member is provided with a limiting groove.