RU2350424C1 - Production method of headed bolt allowing internal polyhedron and flange, on cold-upsetting automation - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: production method of headed bolt allowing internal plyhedron and flange on cold-upsetting automate includes blank cutoff, further preliminary upset of fillister head and rod spinning, length of which is equal to length of complete product rod. Then it is formed fillister head of bolt till receiving of the diameter, equal to 1.01-1.02 of bolt head diameter of complete product. Then at one position it is implemented fabrication of flange and internal polyhedral chamber in a head. At following positions it is implemented bolt body reducing and lead-in chamfering at the end of a rod on pointing installation of cold-upsetting automate, with keeping of received in advance sizes of bolt head and flange, and at the last position it is implemented thread rolling.

EFFECT: ensured by optimal assignment of manufacturing efforts by upset passes and simplification of forging equipment, improvement of complete products and increasing of form tool durability.

2 cl, 1 dwg

Description

The invention relates to the processing of metals by pressure and can be used for cold heading fasteners.

A known method of manufacturing a screw with an internal hexagon, including cutting a workpiece, extruding the rod and forming the head, shaping the hexagonal cavity in the head, calibrating the head and rolling the thread (RF patent No. 2204457, class B21K 1/46).

The known method has the following disadvantages:

- low resistance of the cold heading tool when extruding the rod due to a high degree of deformation (more than 60%), which leads to the loss of phosphate coating and to the appearance of scoring on the rod at subsequent positions;

- the method does not provide stability and manufacturing quality of the screws in geometric parameters.

The technical result from the use of the invention lies in the fact that due to the optimal distribution of technological efforts along the transitions of landing and simplification of die tooling, the quality of manufactured products will increase, the resistance of the forming tool will increase.

The technical result is achieved by the fact that in the method of manufacturing a bolt with a head having an internal polyhedron and a flange, on a cold heading machine, comprising a piece of a workpiece, subsequent preliminary upsetting of the cylindrical head and extrusion of the rod, the length of which is equal to the length of the rod of the finished product, the subsequent formation of the cylindrical head to obtain a diameter equal to 1.01-1.02 of the diameter of the head of the finished product, the formation of the flange and the internal multifaceted cavity in the head, which are carried out on one position, reduction at subsequent positions of the bolt rod and removal of the chamfer at the end of the rod on the sharp-pointed device of the cold dispenser, while at the indicated subsequent positions, the previously obtained dimensions of the bolt head and flange are stored, and the thread is knurled at the last position. Simultaneously with the formation of the flange, a trademark of the manufacturer is applied to it.

The invention is illustrated by the drawing, which shows the manufacturing process of a bolt with a head having an internal polyhedron and a flange on a cold heading machine.

The method is as follows. On a cold heading machine mod. BV-3, a workpiece is cut from steel 20G2P, then a workpiece core is extruded, the length of which l is equal to the length of the finished product L, and the cylinder head is upset. In the second position, they continue to form a cylindrical head up to a diameter D of 1.01 ÷ 1.02 of the diameter of the head of the finished product D _goal , and in the third technological position, the formation of the internal polyhedral cavity in the head of the product and the formation of a flange with the application of a trademark on it are carried out, this, in subsequent operations, the obtained dimensions of the internal multifaceted cavity in the head and flange are stored, then the workpiece rod is reduced, then at the next position, the chamfer at the end of the rod is removed and the last position produces thread rolling.

By obtaining the exact dimensions and shape of the workpiece at the second stamping position, as well as combining the operations of extruding the internal polyhedral cavity in the head and molding the flange at the third position, the internal polyhedral cavity is completely filled and burrs, burrs and wrinkles appear on the side surface of the polyhedron.

Thus, the application of the proposed method helps to reduce the deformation forces of the workpiece at technological transitions, to reduce the friction forces on the working surfaces of the forming tool, as a result, the tool durability and the quality of manufactured products increase.

Claims (2)

1. A method of manufacturing a bolt with a head having an internal polyhedron and a flange on a cold heading machine, comprising a piece of workpiece, subsequent preliminary upsetting of the cylindrical head and extrusion of the rod, the length of which is equal to the length of the rod of the finished product, the subsequent formation of a cylindrical head to obtain a diameter equal to 1, 01 - 1.02 of the diameter of the head of the finished product, the formation of the flange and the internal multifaceted cavity in the head, which are carried out in one position, reduction in subsequent poses rations of the bolt rod and removal of the chamfer at the end of the rod on the cold device of the sharp-pointed device, while at the indicated subsequent positions the previously obtained dimensions of the bolt head and flange are stored, and the thread is rolled at the last position. 2. The method according to claim 1, characterized in that at the same time as the formation of the flange, a trademark of the manufacturer is applied to it.