RU2443523C2 - Method of reconditioning center hoes of tillage row-crop cultivators - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention may be used in reconditioning tillage equipment working tool surfaces. Metal stock is formed in point area and along blade length by electric arc deposition by electrode to produce buffer stock of built-up metal that allows recovery of rated sizes of hoes. Building-up may be carried out both manually and mechanically by electric arc deposition. Hoe is drawn out by hot deformation using forming mandrel that follows hoe point and blade shape. Further hardening is performed by quenching. In buffer metal building-up and drawing-out, thermal processes occur to bring about structural components that increase hardness of reconditioned zone and facilitate increasing resistance to abrasive wear.

EFFECT: longer life due to reconditioning and hardening.

3 dwg

Description

The invention relates to the field of machine repair, in particular to the restoration and hardening of the lancet paws of row cultivators under abrasive wear.

A known method of restoring cultivator paws [1], [2], in which the worn part of the blade is cut with a gas flame cutter or a grinding cutting wheel. In place of the removed part of the blade, the steel profile plate is welded with a continuous seam by automatic electric arc welding under a flux layer or fixed with screws. Next, the legs with welded plates are subjected to flame spraying with wear-resistant metal powders or electrolytic boronation.

The disadvantages of this method is the need:

the manufacture of repair inserts, requiring a sufficiently high accuracy and standardization; removal of worn parts for specific repair dimensions; welding inserts and welding plate attachment.

All these operations are associated with a sufficiently high technological complexity and low economic efficiency.

The closest technical solution, selected as a prototype, is a method of restoring paws by pulling the main material of the paw without preliminary surfacing [3]. The disadvantages of this method should be considered the impossibility of its reuse due to lack of metal stock, as well as a decrease in the cross-sectional area of the paw, leading to a decrease in the rigidity of the structure, leading to a violation of its dimensional stability, and as a result, a low resource.

The technical result of the invention is to increase the durability of the paw, by repeatedly resuming its service characteristics by restoring geometrical parameters that satisfy agrotechnical requirements, forming a new volume of metal by surfacing, followed by drawing and hardening.

Electrode material deposited on the back side will make it possible to compensate for the lost during the previous restoration, or to form a new metal reserve and carry out restoration measures. After restoration, hardening operations are necessary to increase wear resistance (heat treatment).

The specified technical result of the invention is achieved when surfacing the lost area or creating a new metal reserve both in the toe zone and on the surface of the blade. Surfacing is performed by electrode materials for welding and surfacing of carbon steels by electric arc method manually or by a semi-automatic welding machine.

The welded material must have a volume of metal capable of compensating for material loss from wear. After surfacing, the paws are drawn to the appropriate sizes on the forming mandrel (conductor) and subsequent hardening by heat treatment.

The claimed method is carried out due to a number of factors. Is welding on the back side of the paws of the stock of metal in the area of the sock and along the length of the blade (Figure 2). Subsequent hot deformation, carried out to restore the normalized size of the paws, should be carried out using a conductor. The conductor copies the shape of the toe and blade of the paw. The use of the conductor is caused by increased ductility of the deformed zone due to annealing that occurs during surfacing. Therefore, when forging, difficulties arise in giving the paw the desired geometric configuration.

This method, in addition to restoring the working body, provides an increase in the strength and service characteristics of the base material and the wear resistance of the surface as a result of heat treatment.

A comparative analysis of the claimed solution with the prototype shows that the claimed method differs from the known one in that the presence of additional metal on the lower part of the toe of the paw will increase the maintainability of this section of the product, and the cooling of the sock in the water immediately after drawing it will increase the hardness of the deposited material, and therefore , and abrasion resistance.

Thus, the claimed method meets the criteria of the invention of "novelty."

Known technical solutions include: delaying the toe of the paw until the repair stock of metal is exhausted, if such a supply of metal is provided by the manufacturer, or welding additional elements to the paw after removing worn parts above the limit state, which is absent in the proposed method. In addition, the lack of significant machining with abrasive materials due to the use of a jig allows us to conclude that it meets the criterion of "significant differences".

Figure 1-3 presents a paw with broken geometry due to wear and a welded stock of metal from the back.

The implementation of the specified method is illustrated by the example of the universal lancet paw UK 1013. The metal stock is welded with a low-carbon electrode of the UONI brand with a diameter of 3 mm, welding current strength I = 130 ... 140 A, arc voltage U = 20 V.

Surfacing is done in such a way as to copy the installed profile. Paw extraction is performed on a forging hammer at a forging start temperature of about 1300 ° С and ends at 850-870 ° С. Cooling should be carried out from a temperature of 830-850 ° C in water, providing hardening.

Information sources

1. Equipment in agriculture, 1986, No. 8, S. 51-52.

2. Patent of the Russian Federation RU (11) 2325256.

3. Mochalov I.I. et al. Agricultural machinery repair / I.I. Mochalov, S.I. Kostenko, V.A. Vasiliev. - M .: Kolos, 1984. p. 69-71.

Claims (1)

A method of restoring lancet paws of a cultivator with simultaneous hardening, including drawing off until restoration of normalized paw sizes, characterized in that on the back of the paws of the cultivator a metal reserve is formed in the toe region and along the length of the blade by welding with an electrode to obtain a volume of deposited metal that ensures restoration of normalized sizes paws, while the paws are drawn off by hot deformation using a forming mandrel that copies the shape of the toe and blade paws, followed by hardening by hardening.

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