RU2591990C1 - Method of strengthening of earth-cutting knives - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to agricultural machine building, particularly to the tillage machines, and can be used in production and recovery of knives working members cultivators-shears subjected to abrasive wear. Method of strengthening of soil-cutting knives includes build-up on the working surface of the base of double blade solid wear-resistant material rollers in the form of pairwise contacting circles with diameter equal to 3/4 blade width whose centres lie on a common line passing through the middle of blade width.

EFFECT: method of strengthening of higher durability of soil-cutting knives and their operation effect self-sharpening blades with their toothed shape with optimum parameters for reduction of resistance in soil treatment.

1 cl, 2 dwg

Description

The invention relates to agricultural machinery, in particular to tillage machines, and can be used in the manufacture and restoration of knives of the working bodies of cultivators, plane-cutters, subjected to abrasive wear.

A known method of hardening plowshares and other similar parts by continuous deposition on their working surface of an alloy (sormeth) of greater hardness than the base metal of the parts. This allows you to significantly increase their wear resistance (S. Sidorov. Increasing the resource of soil-cutting organs by surfacing alloys / S. Sidorov, A. Sidorov // Mechanization and electrification of agriculture. - 2003. - No. 9. - P.20- 22).

The known method has the following disadvantages: the effect of self-sharpening of the blades is manifested only on some types of soils of medium moisture, and on hard, stony soils and soils of high humidity, the blades become dull, and the deposited layer is painted, which leads to accelerated wear of soil-cutting parts, increased traction resistance of tools and unproductive hard alloy consumption. The process of continuous surfacing is laborious and is associated with a large consumption of surfacing material. In addition, continuous surfacing does not allow to obtain the serrated shape of the blades of the working bodies in the process of their operation.

Also known is the "Method of increasing the durability of parts of the working bodies of tillage machines" (RU 2443524, IPC B23K 9/04 (2006.01) - Declared May 25, 2010; publ. February 2, 2012), carried out by surfacing the rollers in the worn area of the part perpendicular to the geometric shape wear and tear. Rollers are fused in the form of stiffeners at a certain distance from each other. This method is effective in the restoration of structural elements of the working bodies of tillage machines with lucid wear of the working surface.

A disadvantage of the known method is that it does not provide the effect of self-sharpening of the blades during operation and does not allow to obtain their wavy shape.

Closest to the technical nature of the claimed invention and selected for the prototype is the "Method of obtaining wear-resistant blades of the working bodies of tillage tools" (A.S. 461721 USSR, class A01B 15/04. Decl. 25.02.64; publ. 28.02.75, Bull. No. 8), providing for the location of harder metal on the smooth surface of the blades intermittently and parallel to the cutting edge. The known method allows to increase the wear resistance of parts, to improve self-sharpening and to obtain a wavy shape of the blades when they wear.

The disadvantages of this method: a smoothly deposited layer of solid metal is not firmly held on the surface of the part. In addition, the absence in the known method of clear instructions on the parameters of the restriction and the shape of the weld zone does not ensure the receipt during operation of serrated blades with optimal parameters of its protrusions and depressions to reduce resistance when processing the soil.

The basis of the invention is the technical task of creating a new method of hardening of soil-cutting knives with the achievement of a technical result - increasing the durability of soil-cutting knives and ensuring the effect of self-sharpening of the blades during their operation with the formation of their serrated shape with optimal parameters, which helps to reduce resistance during soil cultivation.

The problem is solved due to the fact that the proposed method of hardening of soil-cutting knives provides for surfacing on the working surface of the base of a bilateral knife of a hard wear-resistant material with rollers in the form of pairwise contacting circles with a diameter equal to 3/4 of the width of the knife, the centers of which are located on a common line through the middle the width of the knife.

New significant features:

1. Solid wear-resistant material is deposited on the working surface of the base of a double-sided knife with rollers in the form of pairwise contacting circles with a diameter equal to 3/4 of the width of the knife.

2. The centers of the circles of the weld beads are placed on a common line passing through the middle of the width of the knife.

These new significant features in conjunction with the known allow to obtain a technical result achieved by using the invention.

The invention is illustrated by drawings (Fig. 1, Fig. 2).

In FIG. 1 shows a hardening scheme of a bilateral soil-cutting knife according to the proposed method, FIG. 2 is a section A-A of FIG. 1, where 1 is the base of the bilateral soil-cutting knife, 2 are the original knife blades, 3 are the deposited hard wear-resistant material rollers, 4 is the line passing through the middle of the knife width, 5 are the lines of the knife blades formed as a result of its wear during operation, b - the width of the soil-cutting knife, d is the diameter of the circles of the rollers of the deposited solid material.

The proposed method of hardening soil-cutting knives is carried out in this sequence. Pre-calculate the circumference of the circumference of the rollers of the deposited wear-resistant material according to the formula:

,

,

where d is the diameter of the circumferences of the rollers of the deposited solid material;

b is the width of the soil-cutting knife.

Based on the calculations performed, mark in accordance with FIG. 1 on the working surface 1 of the soil-cutting knife, the line 4 of its middle and on it are the centers and contours of pairwise contacting circles with a diameter d of the rollers 3 of the deposited hard wear-resistant material, possibly combining the centers of these circles with the centers of the holes for the bolts of the soil-cutting knife. According to the marking, surfacing is performed (for example, by an electric arc method) on the working surface 1 of the soil-cutting knife of the first roller of a hard wear-resistant material in the form of a circle with a diameter d (see Fig. 1, 2). Then, the second roller is surfaced in the form of a circle with a diameter d in contact with the first roller. Surfacing of the remaining rollers is performed similarly.

Surfacing a hard wear-resistant alloy according to the method of the invention can be carried out both manually and mechanically.

During operation of a double-sided soil-cutting knife, hardened by the proposed method, due to abrasive wear in the soil, one of its working blades 2, cutting the soil layer, acquires a wavy shape with protrusions and depressions, shown by dashed line 5 in FIG. 1, and on the protrusions the blade is more durable due to the deposited rollers of a hard wear-resistant material in the form of circular arcs 3. When such a wavy blade interacts with the soil, the contact pressure concentrates on the hardened protrusions, contributing to effective cleavage of the soil, while it glides in the depressions between the protrusions, deepening them with minimal resistance. As a result of the redistribution of contact pressure and soil sliding along the blade, its cutting edge is self-sharpening. Shearing of the soil by the protrusions of the blade with its sliding and the effect of self-sharpening the cutting edge together lead to a significant decrease in resistance when processing the soil, and this reduces wear and increases the durability of the soil-cutting knife.

Upon reaching the wear of the working blade of the soil-cutting knife of the maximum size, it is reinstalled with a rotation of 180 ° and the second blade of the knife comes into operation, functioning similarly to the first blade. Thus, the technical result of the claimed invention is achieved.

Claims (1)

A method of hardening soil-cutting knives, comprising applying a wear-resistant material to the surface of the knife base, characterized in that the hard wear-resistant material is deposited on the working surface of the double-sided knife with rollers in the form of pairwise contacting circles with a diameter equal to 3/4 of the knife width, the centers of which are located on a common line passing through the middle of the width of the knife.

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