SU1708486A1 - Method for making blade working members of agricultural machines - Google Patents

Abstract

The invention relates to the processing of metals by pressure, in particular to the manufacture of agricultural machinery, for example, blanks of the type of bits of agricultural implements. The purpose of the invention is to increase the utilization rate of the workpiece material and the durability of the deforming tool. Plastic deformation of the blades, the tangent of which the angle of inclination to the base plane is not less than the coefficient of friction between the wedge working surface of the punch and the workpiece, occurs under conditions of free flow of the metal of the workpiece throughout the working stroke of the punch. Due to this, the blades are formed simultaneously on two blanks. When deforming the end sections of the workpiece (when receiving double-sided bits, their length is chosen not less than half the length of the projections in terms of the wedge surface of the blade. 1 Cp f-crystals, 3 silts. The invention relates to pressure treatment of metals, in particular, to methods of manufacturing agricultural products of the invention is an increase in the utilization of the material of the workpiece and the durability of the deforming tool.Fig. 1 is a diagram of of the elastic shaping of the blade part of bits with a tapering angle a of strip width ao and thickness ho; in Fig. 2 a workpiece after deformation, plan view; in Fig. 3 a diagram of a plastic shaping of blades with a double wedge angle wedge / Method carried out as follows The initial blank in the form of a strip, the length of which, for example, is designed to produce two pieces of billets, is heated to a stamping temperature and subjected to plastic deformation in a stamp using a wedge punch on a flat plate (FIG. one). When stamping a strip designed to obtain two bits with a one-sided arrangement of the blades, the edge of the wedge punch is placed in the middle of the length of the workpiece. VIO 00i.iOO iO

Description

If several chisels with double-sided blades are stamped, the wedge punch and the end portions of the strip blank are deformed. At the same time, for the quality design of the blade part in the extreme areas of the workpiece, it is necessary to limit the length of the end section forming the so-called knife waste. The minimum length of the blade for symmetry of the location of the deformation zone should not be less than the length of the projection in terms of the wedge surface of the blade (or, equivalently, the distance from the projection on the original strip of the edge of the wedge punch to the edge of the strip should not be less than half the length of the projection in terms of the wedge blade). Based on this, the deforming of the double-sided blades on the strip original blank, designed to produce a single product, is also carried out.

During plastic shaping of the blade under the conditions of free flow of metal from under the wedge forming punch, the occurrence of the following conditions is required for the occurrence of tensile stresses in the deformation zone.

Pcp-tga / -as

where Рср - the average specific force acting on the deformable metal is normal to the surface of the strip blank; a-wedge angle;

 - the coefficient of friction between the working surface of the punch and the deformable workpiece;

 yield stress of the workpiece material at given temperature and speed conditions of deformation.

Taking into account the well-known Pcp K-OS dependence, this condition can be represented as Ktg, where K is the proportionality coefficient.

ACCEPTABLE to simplify K 1, get tga /. By taking into account the recommended values, and 0.18-0.27, using an aqueous suspension of graphite, taken in an amount of 5-35%, as a lubricant, is obtained. Taking into account that in actual stamping processes K 1, a value of 12 ° can be considered as the minimum value of the angle a, at which tensile stresses occur. Upon plastic shaping of the blade part, the wedge punch, after contact with the surface of the strip preform, provides free flow of metal from under the punch along the strip as it penetrates almost the entire thickness of the preform. Properly selected lubricant

in most cases, provides complete separation of the blade from the strip, but at the same time the stamped blades of the two products are not always separated

from each other. Therefore, after punching, an additional step of dividing adjacent blades along their intersection line is carried out, for example by shifting in a plane perpendicular to the plane of the common blade.

0 base products.

Example. A billet of a KVU 40.403 reverse bit is obtained with a length of 405 mm, a width of 120 mm, a thickness of 18 mm, a wedge sharpening angle and a 17 ° and a 3 ° 30 °. Product material - 65G steel. The original strip billet with a thickness of 18 mm, a width of 120 mm and a length of 2352 mm is heated in an inductor to 1050-1150 ° C with a width of the heating zone equal to the length of the section

0 plastic deformation, and then placed in a stamp and forming the blade part on the first workpiece, and then on the next. The length of each end portion exposed

5 plastic deformation, equal to 20 mm. In the process of plastic deformation, the workpiece elongates by 26 mm, which makes it possible to use a strip with a length of 2352 to obtain six products.

0 mm instead of 2430 mm in the manufacture of blades by milling.

After shaping the blades, bit cuttings are drilled, punched or drilled to fasten them.

Claims (2)

1. A method of manufacturing a blade working bodies of agricultural machines, including heating the original strip billet, forming 0 blades by plastic deformation at the same time on two blanks with metal outflow on both sides of the punch, as well as the separation of the molded products, about 1 T that is, so that 5 of increasing the utilization of the material of the workpiece and the durability of the deforming tool, on each workpiece form blades in the form of vertices facing one another 0 wedges, the tangent of the angle of inclination of each of which to the base plane is not less than the coefficient of friction between the working surface of the punch and the deformable workpiece, plastic deformation 5, billets with free flow of metal throughout the working stroke of the punch, and the separation of billets with molded blades are carried out in a plane passing through the junction line of the wedge tops of adjacent billets and perpendicular to the plane of their common base. 2. A method according to claim 1, characterized in that, in order to improve the quality of the items in the manufacture of double-sided blades, 5 blades. the length of the knife waste on each extreme section of the original strip blank is chosen not less than the full length of the horizontal projection of the wedge surface -n- FIG. i ag.2.