SU1690934A1 - Method of hydraulic extrusion of blanks - Google Patents

Abstract

The invention relates to the processing of metals by pressure and can be used in mechanical engineering for the work hardening of workpieces. The aim of the invention is to reduce the labor intensity by eliminating the operation of applying lubricant to the surface of the workpieces and increasing tool life. Grease, for example petrolatum, is served as cooled from (: 10) to (-30) From briquette 3 together with workpiece 2. When pressed by plunger 4 of briquette 3, the plastic grease was pressed into the annular gap between the workpiece 2 and container 1 and the surface of the workpiece 2 was coated lubricant. Upon further movement of the plunger 4, the column of grease above the workpiece 2 was squeezed out through the annular gap between the plunger and the container 1. During the return stroke of the plunger 4, the channel of the container 1 was completely freed from the grease, after which the subsequent billet was loaded together with the briquette 3. 2 h. the item of f-ly, 2il., 1 tab. y

Description

The invention relates to the processing of metals by pressure and can be used in mechanical engineering for the work hardening of workpieces.

The aim of the invention is to reduce the labor intensity by eliminating the operation of applying lubricant to the surface of the workpieces and improving tool life.

FIG. 1 and 2 depict a scheme for implementing the method.

Grease, such as petrolatum, which simultaneously serves as a transfer medium and provides effective lubrication of the workpiece in the deformation zone and the sealing ring, is supplied in the form of cooled briquettes together with the workpieces, as a result of which the preparation and loading of the workpieces into the container is simplified, while labor intensity and pressing force, and the tightness of the working cavity of the container is increased.

Cooling the briquettes to (-10) - (-30) ° C increases the viscosity of the grease, which reduces friction losses as a result of providing a more efficient lubricating layer in the deformation zone.

Grease lubrication - oily lubricants obtained by adding solid thickener (paraffin, soap, silica gel, and

etc.) A blank 2 with a diameter of 48 mm and a length of 85 mm, made of steel 45, was placed into the cavity of container 1, after which a cylindrical cooled briquette 3 of petrolatum grease was loaded. When compressed by plunger 4 of the briquette 3 in the cavity of the container 1, the plastic lubricant of the briquette 3 and being between the workpieces 5 and 6 was pressed into the annular gap between the workpiece 2 and the container 1 and the surface of the workpiece 2 was coated with grease. With further compression of the briquette 3, the blanks 2 and 6 were deformed in the matrix 7. After leaving the matrix 7 of the first blank 6, the second blank 2 was partially deformed and the process was stopped. Upon further movement of the plunger 4, about 90% of the height of the column of grease 8, located above the workpiece 2, was squeezed out through the annular gap between the plunger 4 and the container 1 (FIG. 2). During the return stroke of the plunger 4, the channel of the container 1 was completely freed from grease and loading of the subsequent billet together with the grease briquette into the working cavity of the container was carried out smoothly. The tables are tabulated.

As can be seen from the table, the process of applying lubricant to the surface of the workpieces is eliminated and the time of their loading into the working cavity of the container is reduced, while the pressing pressure is reduced by 8% and the durability of the dies increases.

Petrolatum is a mixture of paraffins and ceresins with residual oil, released during dewaxing of petroleum oils.

At a temperature of 5 ° C and below, petrolamum hardens, its friction coefficient decreases, but at the same time

plasticity at high hydrostatic pressures, which ensures the transfer of pressure from the plunger to the end of the workpiece and its radial support. As a result, the pressing force is reduced - the process is more stable due to the absence of pressure peaks at the moment the workpiece starts to deform.

Cooling briquettes to -30 ° C grease significantly increases the durability of the matrix. Cooling briquettes to a lower temperature due to technical difficulties is impractical. Using the proposed method of hydraulic pressing blanks provides

process stabilization; reliable tightness; the ability to press without first applying a lubricating layer to the surface of the blanks; reduction of lubricant consumption

reducing the complexity and duration of operations, which improves the quality of products, the durability of the installation and the tool (matrices).

Claims (3)

1. Method of hydraulic pressing of the workpieces, in which the container with the working medium is deformed with the press residue, the workpiece is behind the workpiece, so that, in order to reduce the labor intensity by eliminating the operation of applying lubricant to the surface billets and, as a working medium, grease is used, which in the form of a cylindrical briquette is fed before pressing each subsequent billet, and after the deformation process is over, the rest above the end face the previous billet lubricant is removed from the container. 2. A method of pop 1, characterized in that petrolatum is used as the working medium. 3. A method according to claim 1, characterized in that the briquettes are cooled in a temperature range from (-1 0) to (-30) ° C before the lubricant container is fed into the cavity of the container.