RU2019332C1 - Part straightening method - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: method involves providing initial action of indenters on part by applying admissible force for straightening the part; moving indenters and providing further action by these indenters on part while retaining the extent of flexure of part after initial straightening. Displacement of indenters during straightening allows load to be repeatedly applied without formation of riveting in the zones of contact between part and indenters and additional plastic deformation of shaft beyond riveting zones to be provided. Additional plastic deformations allow bending left after initial straightening operation to be eliminated. Such set of features allows parts to be straightened with greater bending extent, with straightening forces being limited by part material ultimate strength. EFFECT: high quality of parts and enhanced reliability in operation. 2 cl, 2 dwg

Description

 The invention relates to the processing of metals by pressure, in particular to the editing of parts from brittle materials, for example, to the editing of cast-iron crankshafts.

 There is a method of editing parts by installing it on a support and acting on its concave part with two indenters, leaving traces.

 The known method is applicable for dressing steel crankshafts, since fillets are the weakest point of the neck of the shaft. When editing crankshafts from cast iron, this method does not ensure the quality of editing, causing cracks and breakages.

 The objective of the invention is the ability to edit the part with a large deflection when the dressing forces are within acceptable limits, limited by the tensile strength of the material of the part.

 The technical result is achieved due to the fact that in the method of dressing a part by installing it on a support and acting on its concave part with two indenters, leaving traces while maintaining the curvature of the part after the initial application of the maximum allowable load, the indenters displace and act on the part outside the track on it from the initial exposure of the indenters. In this case, when editing the crankshaft, the indenters are displaced towards each other and they act on the part at the same distance from the original traces of their impact.

 The displacement of the indenters when dressing the part with a significant deflection allows you to repeatedly apply the load without forming hardening on the part in the zones of its contact with the indenters.

 When editing the shaft with the indenters displaced beyond their original tracks along the dressing plane, additional plastic deformation of the shaft outside the hardening zones occurs, which eliminates the curvature remaining after the initial editing of the shaft (before the indenters were shifted).

 In FIG. 1 shows the initial position of the indenters and the change in the bending of the shaft under the action of the permissible load in the deflection plane; in FIG. 2 - the indenters are displaced inward beyond the initial traces from them and the change in the bending of the shaft under the action of a load in the deflection plane does not exceed the tensile strength of the shaft material.

 You can offset several times and apply a load below the limit value until the part is fully straightened.

 For editing, use the support 1 and the pressure unit 2 with indenters 3. On the support 1, a straightened part, for example, the curved neck of the crankshaft 4, is laid on the convex side and the indenters 3 of the pressure unit 2 are acted upon from the concave side by bending to the opposite side deflection.

 Having established that the part has a large deflection, which cannot be completely eliminated by a single application of the maximum allowable force withstood by the shaft without breaking, the following actions are performed.

 On the support 1 lay the convex side of the part, the bend of which must be eliminated. From the part opposite from the support, through indenters 3 located at a distance of "A" and the pressure unit 2, apply the maximum static force P, permissible under the conditions of the strength of the part.

 As a result of applying this force, the part is partially straightened, i.e. its deflection becomes smaller. Then the part is freed from the load, the indenters are displaced (in this case, the distance is brought together and made equal to “B”) in the pressure unit beyond the initial traces of them and in the deflection plane the application of static force is repeated, which may be equal to or less than the initial one.

 Under the action of the force P, the indenters act on the parts of the part outside the original traces from them, on which there is no hardening, and as a result of plastic deformations under the indenters in these areas, the subsequent straightening of the part occurs.

 These steps are repeated until the deflection is completely eliminated.

Claims (2)

 1. METHOD OF EDITING DETAILS by installing it on a support and exposing it to its concave part by two indenters with leaving traces, characterized in that while maintaining the curvature of the part after the initial application of the maximum allowable load, the indenters displace and affect them on the part beyond the tracks on it from the original impact of indenters.  2. The method according to p. 1, characterized in that the indenters are displaced towards each other and act on the part at the same distance from the original traces of their impact.

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