RU2475348C1 - Method of burnishing - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, namely, to mandrelling. Part hole and mandrel surfaces are lubed. Mandrel is pushed through part deformable hole. Mandrel is used with taper lead and inverse cone and gaging working surface with regular micro relief to allow continuous lubing of plastic deformation. Lubrication material represents machine oil with addition of 20%-copper-bearing additive that features antiwear, antioxidant and oil-soluble properties to form servovite metal-plating films in plastic strain zone.

EFFECT: higher wear resistance and decreased mandrelling force.

3 dwg, 1 ex

Description

The invention relates to the processing of metals by pressure, and in particular to processes of burnishing holes.

There is a known method of burnishing according to the Copyright Certificate of the USSR No. 1782709 (IPC V24V 39/02, publ. 23.12.1992). The essence of the method consists in pushing a deforming tool (mandrel) through the deformable hole with the intake and return housings and with a calibrating (working) surface made with a predetermined regular microrelief to ensure continuous supply of lubricant to the zone of the deformation zone, which improves the quality of the processed hole surface due to decrease in roughness and increase in microhardness.

The disadvantage of this method is the low wear resistance of the mandrel and significant force burnishing.

The technical result of the present invention is a significant increase in the wear resistance of the mandrel and a decrease in the force of burning.

The technical result is achieved by the fact that the deformable hole and the surface of the mandrel with the intake and return cones and with a calibrating (working) surface, made with a given regular microrelief to ensure a continuous supply of lubricant to the zone of the deformation zone, is lubricated with lubricant, which is used as machine oil with the addition of up to 20% copper-containing additive with metal-cladding anti-wear antioxidant and oil-soluble properties, forming in the focus lasticheskoy deformation of the thin copper film servovitnye impeding mandrel intensive wear and reduces the force dornovanija.

Such an additive may be a copper-containing additive having metal-cladding anti-wear antioxidant and oil-soluble properties of the Valena brand according to RF patent No. 2277579 (IPC S10M 141/06, S10M 133/12, S10M 133/16, S10M 133/38, S10M 129/04, С10М 129/26, С10М 125/00, C10N 30/06, publ. 06/10/2006).

Figure 1 shows the interaction of the regular microrelief of the mandrel 1 with the surface of the machined hole 3 of the part 4;

figure 2 - graphs of the specific forces of burning from the actual interference during deformation and the concentration of the copper-containing additive "Valena", with metal cladding anti-wear antioxidant and oil-soluble properties, in oil;

figure 3 - graphs of the linear wear of the mandrel from the specific force of the mandrel q _d ; the actual tightness during burnishing and the concentration of the copper-containing additive "Valena", which has metal-cladding anti-wear antioxidant and oil-soluble properties, in oil.

The mandrel consists of a fence cone 5, a gauge section 6 and a reverse cone 7. The microrelief 1 on the gauge section of the mandrel 6 can be calculated or selected according to GOST 24773-81, as well as according to USSR copyright certificates No. 1459131, 1782709.

The method of burnishing is as follows. The surface of the hole 3 of part 4 and the surface of the mandrel 5, 6, 7 are lubricated with a lubricant, which is used as machine oil with the addition of up to 20% copper-containing additive, which has metal-cladable anti-wear antioxidant and oil-soluble properties, forming thin servovitic films in the center of plastic deformation of the hole copper, which prevents intensive wear of the deforming tool and reduces the force of burning.

An example of the method

In laboratory conditions, the proposed method of burnishing was tested. As samples, brass bushings LS-59 were selected with dimensions: height 40 mm; the outer diameter is 39 mm; the inner diameter, which has been burned, is 20 mm. The mandrel material with a microrelief on its working part is U8A with hardening to a hardness of HRC 58-60 units. The magnitude of the interference during the burning of holes with a diameter of 20 mm bushings 0 ... 0.4 mm

As a lubricant, a 14MB brand engine oil is used with the addition of the Valena copper-containing additive, which has metal-cladable anti-wear antioxidant and oil-soluble properties. The concentration of the additive in the oil was 0, 10 and 20%.

Burning tests for brass bushings were carried out on a hydraulic press with a force of 100 ton-force in the pressure processing laboratory of MSTU im. N.E.Bauman.

Each test option was carried out three times. Burning speed was equal to 50 mm / min. The axial load was 20 ... 40 tf. When tested for wear resistance of the mandrel, the number of samples increased to 1000 pcs.

Based on the results of the tests, graphs of the dependence of the specific force of the mandrel on the actual interference during deformation and the concentration of the copper-containing additive "Valena", which has metal-cladding anti-wear antioxidant and oil-soluble properties in oil (Fig. 2), and graphs of the dependence of the linear wear of the mandrel on the specific force of mandrel q _e , the actual tightness during burnishing and the concentration of the copper-containing additive "Valena", which has metal-cladable anti-wear anti-oxidants analytical and oil-soluble properties in oil (figure 3).

понимают отношение усилия дорнования Р к длине окружности дорнируемого отверстия ПД; i_ф - натяг при дорновании; U_л - величина линейного износа при дорновании 1000 латунных образцов марки ЛС-59; К - концентрация медьсодержащей присадки «Валена», обладающей металлоплакирующими противоизносными антиокислительными и маслорастворимыми свойствами, в базовом масле 14МВ.Under specific force

understand the ratio of the force of the mandrel P to the circumference of the mandrel hole PD; i _f - interference during burnishing; U _l - the value of linear wear during the burning of 1000 brass specimens of the brand LS-59; K is the concentration of the copper-containing additive "Valena", which has metal-cladding anti-wear antioxidant and oil-soluble properties, in 14MB base oil.

From the graphs constructed according to experimental data, it follows:

, а при концентрации присадки 20% - на

.1. Specific force of burning. At a concentration of a copper-containing additive with metal-cladding anti-wear antioxidant and oil-soluble properties, 10% in 14MV engine oil at a maximum interference fit of 0.4 mm, the specific forces of burning are reduced by

and at an additive concentration of 20% - by

.

, при концентрации присадки 20% - на

.2. Linear wear U _l when testing the burnishing of holes in brass samples per 1000 pcs. samples decreased at a concentration of copper-containing additives with metal-cladding anti-wear antioxidant and oil-soluble properties, 10% - by

, at an additive concentration of 20% - by

.

Burning test results by the proposed method show a decrease in the linear wear of the mandrel by 53 ... 73%, a decrease in the burning force by 7.0 ... 27.5%, depending on the concentration of the copper-containing additive "Valena", which has metal-cladable anti-wear antioxidant and oil-soluble properties.

Information sources

1. GOST 24.773-81. Surfaces with regular microrelief. Classification, parameters and characteristics.

2. USSR Copyright Certificate No. 1459131. The method of formation of microrelief.

3. USSR copyright certificate No. 1782709. Burning method (prototype).

4. RF patent No. 2277579. Metal-containing oil-soluble composition for lubricants.

Claims (1)

A method of burning parts, including pushing a mandrel of a mandrel with an intake and reverse cones and a calibrating working surface made with a predetermined regular microrelief to ensure continuous supply of lubricant to the zone of the plastic deformation zone, characterized in that the part hole surface and the mandrel surface are lubricated with lubricant material, as the latter use machine oil with the addition of up to 20% of a copper-containing additive with antiwear, antioxidant and oil-soluble properties and metal-clad servovitic films of copper forming in the zone of the center of plastic deformation.

Images