SU1669691A1 - A method of strengthening crankshaft fillets - Google Patents

Abstract

The invention relates to mechanical processing, in particular to the hardening of crankshafts by surface plastic deformation (PPD). The goal is to improve the quality of the surface during the formation and undercut of the small fillets of the SPD. To do this, on the necks of the crankshafts after quenching with high frequency currents and polishing, the rectangular grooves adjacent to the cheeks, which are undercut in the neck, are cut through. The width of the grooves is 0.05 - 0.06 neck diameter, and a depth of 0.07 - 0.08 neck diameter. Thereafter, a small-radius PPD fillet is formed R = (0.01 - 0.025) D _ш with simultaneous rolling of the entire neck with a cylindrical roller for rolling in the fillet in the fillet. The grooved undercut creates conditions for the application of multi-circular grinding of the necks. 2 ill., 1 tab.

Description

The invention relates to the machining, in particular, to methods of hardening by surface plastic deformation (PPM of crankshafts), for example, autotractor engines

The purpose of the invention is to improve the processing conditions and improve the quality of the surface during the formation and undercut of small fillets by surface plastic deformation.

FIG. 1 shows a small fillet, formed by a roller with an influx of extruded metal on the shaft neck, FIG. 2 - a groove cut on the shaft neck, under the subsequent formation of a small fillet.

The method is carried out as follows.

On the necks of full-length crankshafts 1, after quenching with HDTV and semi-abrasive grinding, the rectangular grooves 2 adjacent to the cheeks are cut into the neck, adjacent to the cheeks.

The parameters of the groove width - (0.05- 0.06) Osh, where Dm is the diameter of the neck, depth - 0.01 RSH.

After that, a fillet of small radius g (0.01–0.025pls with simultaneous rolling of the whole neck with a cylindrical roller to roll the fillet into the fillet) is formed by surface plastic deformation, and the neck is finally polished

At the same time, for comparison, another batch of crankshafts was machined.

1. According to the technology adopted at the factory, fine grinding of the necks, cheeks and (altels with a radius R 0.06 Osh, processing of fillets by surface plastic deformation, superfinishing of the necks

2. According to a known method of grinding necks and fillets with a radius of 0.1-0.5 mm plastic deformation of fillets with a radius of mustache (0.01-0.025 pts.

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Crankshaft compartments, treated in three ways, were fatigue resistant.

The results are shown in the table.

Crankshafts, processed by known technology, had the same fatigue strength, as shafts, processed by the proposed option. However, on the necks of these shafts during the plastic deformation of a small fillet a high metal flow was formed. During subsequent grinding, he cuts the grinding wheel, causing it to wear intensively, which is unacceptable for the masses to produce pas.

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Claims (1)

The invention of the method of hardening fillets crankshafts, with which carry out grinding necks with a radius of fillets of 0.01-0.05 mm and the formation of surface plastic deformation along a radius of 0.01-0.025 diameters of the neck and the final machining, which differs from , in order to improve the quality of non-rigid crankshafts, before surface plastic deformation at the junction of the neck and cheek, cut a rectangular groove with a depth of h 0.07–0.08 of the neck diameter and width, 05–0.06 of the neck diameter, and Plastic deformation is carried out with simultaneous rolling. Crankshaft characteristic Processing by technology Processing the proposed option Processing by known technology Fatigue strength, kgf / mm2 17 24 23 b-, ML A PPI galteli cR 10.0 2 / pi - (-OM5W PPB fillets with R (0.05) Serial non-strength, 151) ten (Rig. G (0.01-0.025) 1)