阅读说明：本技术 一种高强度螺母冷镦成型工艺 (Cold heading forming process for high-strength nut ) 是由 叶伟峰 于 2020-05-30 设计创作，主要内容包括：本发明提供一种高强度螺母冷镦成型工艺,包括皂化处理、切料、整镦、镦球、球化退火处理、预成型、成型、精成型、冲孔步骤。本发明设计合理,通过在镦球和预成型步骤之间加入退火处理,将将金属进行软化,来消除金属的应力,使金属组织更加均匀,且改善了金属的冷变形塑性,降低后续冷镦成型的难度；通过在剪切前增加对金属材料的皂化处理,来增加金属材料的表面润滑度,降低变形体和模具工作表面的摩擦力,即降低变形中由于摩擦而产生的拉应力。(The invention provides a cold heading forming process of a high-strength nut, which comprises the steps of saponification treatment, material cutting, whole heading, heading ball, spheroidizing annealing treatment, preforming, forming, fine forming and punching. The invention has reasonable design, and the annealing treatment is added between the upsetting ball and the preforming step to soften the metal so as to eliminate the stress of the metal, so that the metal structure is more uniform, the cold deformation plasticity of the metal is improved, and the difficulty of subsequent cold upsetting forming is reduced; by adding saponification treatment to the metal material before shearing, the surface smoothness of the metal material is increased, and the friction force between a deformation body and the working surface of a die is reduced, namely the tensile stress generated by friction in deformation is reduced.)

1. A cold heading forming process for a high-strength nut is characterized by comprising the following steps: the method comprises the following steps:

step 1, saponification treatment, namely performing saponification liquid treatment on the surface of a metal wire;

step 2, cutting, namely cutting metal wires with the suitable specification and size;

step 3, performing whole upsetting, namely performing cold upsetting on the round metal bar to form a fillet at the bottom of the round metal bar so as to obtain a first semi-finished product;

step 4, upsetting the first semi-finished product into an upper drum-shaped ball shape and a lower drum-shaped ball shape to form a second semi-finished product;

step 5, spheroidizing annealing treatment, softening annealing treatment is carried out on the obtained second semi-finished product,

step 6, performing, namely performing cold heading treatment on the semi-finished product obtained in the step to enable the head and tail profiles of the nut to be approximately formed, so as to obtain a third semi-finished product;

step 7, forming, namely further rolling and spreading the third semi-finished product to enable the head of the nut to be flat and cylindrical, the tail of the nut to be hexagonal, and basically forming the nut to obtain a fourth semi-finished product;

8, fine forming, namely performing upsetting forming on the head and the tail of the nut again to enable the size of the nut to further meet the requirement to obtain a fifth semi-finished product;

and 9, punching, namely tapping and punching the fifth semi-finished product to finish the forming processing of the nut.

2. The cold heading forming process for the high-strength nut as claimed in claim 1, wherein the cold heading forming process comprises the following steps: in the step 1, the surface of the first semi-finished product is cleaned, after the surface is free of oil stains, the saponified solution is heated, soaked for 3-8 minutes and then taken out, after drying, the saponified solution is soaked for 8-15 minutes and then taken out, and after drying, the saponified solution is used subsequently.

3. The cold heading forming process for the high-strength nut as claimed in claim 1, wherein the cold heading forming process comprises the following steps: in the step 5, isothermal spheroidizing annealing is used, the heating temperature is Ac1+ 20-30 ℃, the temperature is kept, then the product is cooled to Ar 1-20-30 ℃, after isothermal for a period of time, the product is taken out of the furnace and cooled by air, and the next operation is carried out.

4. The utility model provides a cold-heading mould for making high strength nut which characterized in that: comprises five moulds, a first mould and a second mould,

the first die is used for forming a round chamfer on the bottom of the metal wire to obtain a first semi-finished product;

the second die is used for upsetting the first semi-finished product into an upper drum-shaped ball and a lower drum-shaped ball to obtain a second semi-finished product;

the third die is used for further calendering and spreading the second semi-finished product, so that the side length of the second semi-finished product is increased while the thickness of the second semi-finished product is reduced, and a third semi-finished product is obtained;

the fourth die is used for further calendering and spreading the third semi-finished product, reducing the thickness of the third semi-finished product and increasing the side length of the second semi-finished product to enable the head of the nut to be flat and cylindrical, the tail of the nut to be hexagonal and the nut to be basically molded to obtain a fourth semi-finished product;

and the fifth die is used for further calendering the fourth semi-finished product to enable the diameter and the side length of the fourth semi-finished product to further meet the requirements, so that a fifth semi-finished product is obtained.

5. The cold heading die for manufacturing the high-strength nut as claimed in claim 4, wherein: the diameter of the upper drum-shaped spherical structure in the second die is larger than that of the lower drum-shaped spherical structure, and the thickness of the upper drum-shaped spherical structure is smaller than that of the lower drum-shaped spherical structure.

6. The cold heading die for manufacturing the high-strength nut as claimed in claim 4, wherein: and a plurality of triangular grooves are formed in the groove at the bottom of the fifth die, so that the bottom of the obtained fifth semi-finished product is uniformly formed into the triangular grooves.

Technical Field

The invention mainly relates to the technical field of nut processing, in particular to a cold heading forming process for a high-strength nut.

Background

In the current industrial production and daily life, the use of the nut is very common, and the nut is matched with the bolt for combined use, so that various mechanical parts can be installed and fixed, and the integrity and the stability of equipment are ensured.

In the processing process of the nut, most of the cold heading forming is carried out by using a die, most of the cold heading forming is carried out at least twice, the cold heading for the first time and the cold heading for the second time are easy to form, but after the metal material is subjected to multiple cold heading, the metal plasticity is changed due to cold hardening, and the subsequent cold heading forming treatment is influenced.

Disclosure of Invention

Solves the technical problem

The invention mainly provides a cold heading forming process for a high-strength nut, which is used for solving the technical problem that when the conventional nut provided by the background technology is manufactured, after a metal material is subjected to multiple times of cold heading, the plasticity of the metal is changed due to cold work hardening, and the subsequent cold heading forming treatment is further influenced.

Technical scheme

In order to achieve the purpose, the technical scheme provided by the invention is as follows: a cold heading forming process for a high-strength nut comprises the following steps:

step 1, saponification treatment, namely performing saponification liquid treatment on the surface of a metal wire;

step 2, cutting, namely cutting metal wires with the suitable specification and size;

step 3, performing whole upsetting, namely performing cold upsetting on the round metal bar to form a fillet at the bottom of the round metal bar so as to obtain a first semi-finished product;

step 4, upsetting the first semi-finished product into an upper drum-shaped ball shape and a lower drum-shaped ball shape to form a second semi-finished product;

step 5, spheroidizing annealing treatment, softening annealing treatment is carried out on the obtained second semi-finished product,

step 6, performing, namely performing cold heading treatment on the semi-finished product obtained in the step to enable the head and tail profiles of the nut to be approximately formed, so as to obtain a third semi-finished product;

step 7, forming, namely further rolling and spreading the third semi-finished product to enable the head of the nut to be flat and cylindrical, the tail of the nut to be hexagonal, and basically forming the nut to obtain a fourth semi-finished product;

8, fine forming, namely performing upsetting forming on the head and the tail of the nut again to enable the size of the nut to further meet the requirement to obtain a fifth semi-finished product;

and 9, punching, namely tapping and punching the fifth semi-finished product to finish the forming processing of the nut.

Further, in the step 1, the surface of the first semi-finished product is cleaned, after the surface is free of oil stains, the saponified solution is heated, soaked for 3-8 minutes and then taken out, after being dried, the saponified solution is soaked for 8-15 minutes and then taken out, and the first semi-finished product is dried and then used subsequently.

Further, in the step 5, isothermal spheroidizing annealing is used, the heating temperature is Ac1+ 20-30 ℃, the temperature is kept, then the product is cooled to Ar 1-20-30 ℃, after isothermal for a period of time, the product is taken out of the furnace and cooled by air, and the next operation is carried out.

A cold heading die for manufacturing a high-strength nut, which comprises five dies,

the first die is used for forming a round chamfer on the bottom of the metal wire to obtain a first semi-finished product;

the second die is used for upsetting the first semi-finished product into an upper drum-shaped ball and a lower drum-shaped ball to obtain a second semi-finished product;

the third die is used for further calendering and spreading the second semi-finished product, so that the side length of the second semi-finished product is increased while the thickness of the second semi-finished product is reduced, and a third semi-finished product is obtained;

the fourth die is used for further calendering and spreading the third semi-finished product, reducing the thickness of the third semi-finished product and increasing the side length of the second semi-finished product to enable the head of the nut to be flat and cylindrical, the tail of the nut to be hexagonal and the nut to be basically molded to obtain a fourth semi-finished product;

and the fifth die is used for further calendering the fourth semi-finished product to enable the diameter and the side length of the fourth semi-finished product to further meet the requirements, so that a fifth semi-finished product is obtained.

Furthermore, the diameter of the upper drum-shaped spherical structure in the second die is larger than that of the lower drum-shaped spherical structure, and the thickness of the upper drum-shaped spherical structure is smaller than that of the lower drum-shaped spherical structure

Furthermore, a plurality of triangular grooves are formed in the groove in the bottom of the fifth die, so that the bottom of the obtained fifth semi-finished product is uniformly formed into the triangular grooves.

Advantageous effects

Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:

the invention has reasonable design, and the annealing treatment is added between the upsetting ball and the preforming step to soften the metal so as to eliminate the stress of the metal, so that the metal structure is more uniform, the cold deformation plasticity of the metal is improved, and the difficulty of subsequent cold upsetting forming is reduced;

by adding saponification treatment to the metal material before shearing, the surface smoothness of the metal material is increased, and the friction force between a deformation body and the working surface of a die is reduced, namely the tensile stress generated by friction in deformation is reduced.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

In order to facilitate an understanding of the invention, the invention will now be described more fully hereinafter with reference to the accompanying drawings, in which several embodiments of the invention are shown, but which may be embodied in many different forms and are not limited to the embodiments described herein, but rather are provided for the purpose of providing a more thorough disclosure of the invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present; when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present; the terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; the terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention; as used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.