CN213944743U

CN213944743U - Semi-circle head bolt cold heading forging die

Info

Publication number: CN213944743U
Application number: CN202022143929.3U
Authority: CN
Inventors: 何利武; 李兵; 马建; 金秋
Original assignee: Dongfeng Motor Fastener Co ltd
Current assignee: Dongfeng Motor Fastener Co ltd
Priority date: 2020-09-27
Filing date: 2020-09-27
Publication date: 2021-08-13
Anticipated expiration: 2030-09-27

Abstract

The utility model discloses a half round head bolt cold heading forging die, concrete step is as follows: pre-upsetting and forming: putting the rod-shaped blank subjected to cold drawing pretreatment into a pre-upsetting die, and upsetting to obtain an eccentric blank; the head end of the rod-shaped blank is extruded into a frustum shape, and the part of the top end of the frustum, which is used for forming the notch, is in an inclined surface shape; and final upsetting and forming: putting the eccentric pre-upset forging piece formed in the step 1) into a final upsetting forging die, wherein the inclined surface of the eccentric pre-upset forging piece is opposite to the notch forming surface of the final upsetting die, and upsetting to obtain a semi-circular head bolt blank; in the cold heading process, the inclined part of the head is extruded firstly, then the semicircular head of the bolt is formed, the material is saved by 1.58% of the volume of the blank, the semicircular cutting process with high difficulty and complex process is avoided, the manufacturing cost is saved, and the product quality is ensured.

Description

Semi-circle head bolt cold heading forging die

Technical Field

The invention belongs to the field of a semi-circular head bolt cold heading process, and particularly relates to a semi-circular head bolt cold heading die.

Background

The semicircular head bolt is a steel part and is mainly used on automobile wheels. The product is required to have high dimensional accuracy, good mechanical property, larger bearing load, better appearance quality and the like. The production process of the part comprises the following steps: cold drawing the pre-treated blank → cold heading forming → knurling → rolling thread → heat treatment → surface treatment.

As shown in fig. 1, the process for producing the semi-circular head bolt by cold heading comprises the steps of firstly adopting forward extrusion and reducing diameter, simultaneously pre-upsetting the bolt head 1 into a conical body with a spherical crown, then simultaneously upsetting and forming the chamfer angles of the bolt head and the end of the rod part 2, and finally cutting the bolt head into a semi-circular head to form the notch part 3. The cold heading forming process needs to cut a semicircle, the material consumption is large, and when an excircle is cut, a circle of tearing tape is arranged at the excircle of the head of a product; the phenomena of block falling, edge tipping and the like occur on the trimming upper die, and the service life of the die is short; the edge cutting upper die rotates in the circumferential direction in the edge cutting upper die sleeve, so that the single-side positions of the upper die and the lower die are staggered, the material distribution is not smooth, the edge cutting process is complex, and the edge cutting is difficult.

Disclosure of Invention

The invention provides a semi-circular head bolt cold heading die, which solves the problems of low production quality and short service life of a die in the existing cold heading process.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a semi-circular head bolt cold heading die is characterized in that: comprises a multi-station die consisting of a pre-upsetting forming die 4 and a final-upsetting forming die 5; the pre-upsetting forming die is used for upsetting out eccentric head blank pieces, and the final-upsetting forming die is used for upsetting out semi-circular head bolt blank pieces.

The technical scheme is further limited, the pre-upsetting forming die consists of a first fixed die and a first movable die, a positioning hole in the first fixed die is used for positioning a rod part of a blank, and a forming cavity of the first movable die is used for forming a head part of the blank; the head end of the blank piece can be extruded into a frustum shape by the head deflection forming cavity, and the part used for forming the notch on the top end of the frustum is in an inclined surface shape.

The technical scheme is further limited, the angle of the inclined surface is 38-60 degrees, and the preferred angle is 42 degrees.

The technical scheme is further limited, the final upsetting forming die consists of a second fixed die and a second movable die, a positioning hole in the second fixed die is used for positioning a rod part of the blank, and a forming cavity of the second movable die is used for forming a half-round head of the blank; during cold heading, the inclined surface of the eccentric pre-heading forging piece and the notch forming surface of the final heading forging die are oppositely arranged.

Has the advantages that: in the cold heading process, the inclined part of the head is extruded firstly, and then the semicircular head of the bolt is formed, so that the material is saved by 1.58% of the volume of the blank, the semicircular cutting process with high difficulty and complex process is avoided, the manufacturing cost is saved, and the product quality is ensured; in the final upsetting forming step, the inclined surface of the eccentric pre-upsetting forging piece and the notch forming surface of the final upsetting forging die are oppositely arranged,

therefore, the blank material of the upsetting part is reasonably distributed and smoothly flows when the final upsetting is formed, and the shape of the head is ensured.

Drawings

Fig. 1 is a structure view of a half-head bolt blank in the background art.

Fig. 2 is a multi-station cold heading die for a half-head bolt.

Detailed Description

As shown in FIG. 2, a half-round head bolt cold upsetting die comprises a multi-station die consisting of a pre-upsetting forming die and a final upsetting forming die; the pre-upsetting forming die is used for upsetting a deviation head blank, and the final-upsetting forming die is used for upsetting a semi-circular head bolt blank;

as shown in fig. 2, the pre-upsetting forming die 4 is composed of a first fixed die 401 and a first movable die 402, a positioning hole in the first fixed die is used for positioning a rod part of the blank 6, a forming cavity of the first movable die is used for forming an offset head part of the blank, and the first movable die and the first fixed die can be matched; the head end of the rod-shaped blank piece can be extruded into a frustum shape by the head-biased forming cavity, and the part, used for forming the notch, on the top end of the frustum is in an inclined surface shape;

as shown in fig. 2, the final upsetting forming die 5 is composed of a second fixed die 501 and a second movable die 502, a positioning hole in the second fixed die is used for positioning the rod part of the blank member 6, a forming cavity of the second movable die is used for forming the half-round head of the blank member 6, and the second movable die can be matched with the second fixed die; during cold heading, the inclined surface of the eccentric pre-heading forging piece and the notch forming surface of the final heading forging die are oppositely arranged.

Description of the invention: the fixed die and the movable die are assembled on the cold header, and the cold header belongs to common knowledge in the field; the movable mold is closed with the fixed mold through the working end of the cold header.

Claims

1. A semi-circular head bolt cold heading die is characterized in that: the multi-station die comprises a pre-upsetting forming die and a final-upsetting forming die; the pre-upsetting forming die is used for upsetting out eccentric head blank pieces, and the final-upsetting forming die is used for upsetting out semi-circular head bolt blank pieces.

2. A half-head bolt cold heading die according to claim 1, wherein: the pre-upsetting forming die consists of a first fixed die and a first movable die, a positioning hole in the first fixed die is used for positioning a rod part of a blank piece, and a forming cavity of the first movable die is used for forming a head part of the blank piece; the head end of the blank piece can be extruded into a frustum shape by the head deflection forming cavity, and the part used for forming the notch on the top end of the frustum is in an inclined surface shape.

3. A half-head bolt cold heading die according to claim 2, wherein: the angle of inclined plane is 38 ~ 60.

4. A half-head bolt cold heading die according to claim 1 or 2, wherein: the final upsetting forming die consists of a second fixed die and a second movable die, a positioning hole in the second fixed die is used for positioning a rod part of a blank piece, and a forming cavity of the second movable die is used for forming a half-round head of the blank piece; during cold heading, the inclined surface of the eccentric pre-heading forging piece and the notch forming surface of the final heading forging die are oppositely arranged.