RU2534327C2 - Cylinder-piston assembly - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: this assembly comprises piston and cylinder sleeve (8). Piston with compression and scraper rings contacts with cylinder sleeve working that has grooves (9) and (10) filled with nonferrous metal. Hardening surface is applied on piston bottom and grooves of said compression and scraper rings by micro arc oxidation and composed by solid oxidised ply. Grooves (9) are made at points of cylinder sleeve (8) maximum wear that correspond to piston TDC and BDC. Grooves (9) feature the shape of counter sinusoids. Two grooves (10) shaped to two opposed closed separate rings are made at cylinder sleeve (8) mid part, some 0.10-0.12 of sleeve height of top and bottom sinusoid extreme points. Distance from the start of first sinusoidal groove (9) to sleeve top end makes 8-10% of the sleeve working surface height. Cross-section of grooves (9), (10) features depth and width of 0.25 of the sleeve minimum depth. Maximum spacing between adjacent grooves corresponds to that between top compression rings and bottom scraper rings.

EFFECT: higher wear resistance, regular wear of cylinder sleeve.

5 dwg

Description

The invention relates to mechanical engineering, mainly for an internal combustion engine (ICE).

Closest to the technical nature of the claimed invention is a cylinder-piston group [Cylinder-piston group of an internal combustion engine. - Patent RU No. 2451810. Publ. May 27, 2012], including a sleeve, a piston with compression and oil scraper rings in contact with the working surface of the cylinder liner, and grooves filled with non-ferrous metal. Three arrays of annular grooves are made on the working surface of the cylinder liner. The middle array is rotated 90 ° relative to the upper and lower arrays. The distance from the beginning of the first grooves to the upper end of the sleeve is 10 ± 0.5 mm. The grooves are in the form of counterclosed closed rings separate from each other with an angle of elevation of 17 degrees to the diametrical plane of the liner and a pitch of 13 mm. In the cross section, the grooves are toroidal with a depth and width of 1.5 mm. The maximum distance between adjacent grooves corresponds to the distance between the upper compression and lower oil scraper piston rings.

The disadvantages of this device are the reduced wear resistance of the working surface of the cylinder liner in places of increased wear at the top dead center and bottom dead center and increased wear of the grooves for the compression and oil scraper rings, as a result of which the quality of the cylinder-piston group decreases due to the insufficient distribution of non-ferrous metal and the uneven arrangement of the annular grooves on the working surface of the cylinder liner.

The claimed invention is aimed at eliminating these drawbacks and the following technical result was obtained from its use: increasing the wear resistance of the liner and piston, reducing the unevenness of the wear of the cylinder liners in height and grooves for compression and oil scraper rings, improving the quality of the cylinder-piston group.

The specified technical result is achieved by the fact that on the piston bottom and on the grooves of the compression and oil scraper rings, a hardening coating is applied by microarc oxidation in the form of a continuous oxidized layer, while in the places of the greatest wear of the cylinder liner corresponding to the positions of the piston in the upper and lower dead points, grooves are made, having the shape of oncoming sinusoids, and in the middle part of the cylinder liner at a distance of 0.10 ... 0.12 from the height of the cylinder liner of the extreme points of the upper and lower sinusoids, two grooves in the e counter closed rings separate from each other, the distance from the beginning of the first sinusoidal grooves to the upper end of the sleeve is 8-10% of the height of the working surface of the sleeve, in the cross section of the grooves have a depth and width equal to 0.25 of the minimum thickness of the sleeve, the maximum distance between adjacent grooves corresponds to the distance between the upper compression and lower oil scraper piston rings.

In FIG. 1 shows a cylinder liner with altered physical and mechanical characteristics and sinusoidal and annular grooves made on its working surface; FIG. 2 - an internal combustion engine piston having a reinforcing coating made in the form of a continuous oxidized layer on the bottom and grooves for compression and oil scraper rings, in FIG. 3 - a cylinder liner with altered physical and mechanical characteristics in conjunction with an internal combustion engine piston, having a reinforcing coating on the bottom and grooves for compression and oil scraper rings, in FIG. 4 is a diagram of the contact of the piston rings with grooves for compression and oil scraper rings of type A and with the working surface of the cylinder liner, FIG. 5 is a cross-sectional view of a groove in section BB.

The piston-piston group includes a piston 1 with a hardening coating 2 on the bottom 3 and grooves for compression 4, oil scraper 5 rings, compression 6 and oil scraper 7 rings in contact with the working surface of the cylinder liner 8 and grooves 9,10 filled with non-ferrous metal 11. On the working surface of the liner grooves 9 having the shape of oncoming sinusoids are made in the places of greatest wear in the cylinder 8 of the internal combustion engine, and in the middle part of the cylinder liner at a distance of 0.10 ... 0.12 from the cylinder liner height of the extreme points of the upper and lower nusoid 9 two grooves 10 are made in the form of closed rings counter, separate from each other. The distance from the beginning of the first sinusoidal grooves 9 to the upper end of the sleeve is 8 ... 10% of the height of the working surface of the sleeve. In cross section, grooves 9 and 10 have a depth and width of 0.25 of the minimum thickness.

The cylinder piston group works as follows. In the process of ICE operation, the piston 1 with a reinforcing coating 2 on the bottom 3 and grooves for compression 4, oil scraper 5 rings, in contact with rings 6 and 7, make a reciprocating movement up and down. In this case, the rings 6 and 7, moving along the working surface of the sleeve 8, due to plastic deformation, remove part of the non-ferrous metal 11 from the grooves 9 and 10 and “smear” it along the working surface of the sleeve 8 from the top dead center to the bottom dead center. This process occurs during all ICE cycles and continues until a non-ferrous metal layer 11 of a certain thickness is formed on the working surface of the sleeve 8. As a result of this process, the coefficient of friction of the working surfaces of the piston rings 6 and 7 and the working surface of the sleeve 8 decreases, and the rings 6 and 7 cease to remove the non-ferrous metal from the grooves 9 and 10. As the thickness of the “smeared” non-ferrous metal 11 decreases from the surface of the sleeve 8, the coefficient of friction between the working surfaces of the piston rings 6 and 7 and the working surface of the sleeve 8 is slightly increased. At the same time, the intensity of removing the non-ferrous metal 11 from the grooves 9 and 10 by the piston rings 6 and 7 begins to increase, and the process of “smearing” the non-ferrous metal 11 along the working surface of the sleeve 8 is repeated. The process of applying a layer of non-ferrous metal 11 on the working surface of the sleeve 8 accompanies the entire period of operation of the cylinder-piston engine group.

The implementation of annular grooves in the middle part and sinusoidal grooves in places of increased wear will increase the wear resistance and reduce the unevenness of wear along the height of the cylinder liners, and the implementation of the hardening coating on the piston bottom and on the grooves of the compression and oil scraper rings increases the wear resistance of the piston.

Such a design of the cylinder-piston group will improve the quality of the engine.

Claims (1)

A piston-piston group including a piston with compression and oil scraper rings in contact with the working surface of a cylinder liner having grooves filled with non-ferrous metal, characterized in that a reinforcing coating is applied on the piston bottom and on the grooves of the compression and oil scraper rings in the form of a continuous layer of microarc oxidation at the same time, in the places of the greatest wear of the cylinder liner corresponding to the piston positions of the upper and lower dead points, grooves are made, the grooves are in the form of an entire trek sinusoids, in the middle part of the cylinder liner at a distance of 0.10 ... 0.12 from the height of the cylinder liner of the extreme points of the upper and lower sinusoids, two grooves are made in the form of counterclosed closed rings, separate from each other, the distance from the beginning of the first sinusoidal grooves to the upper end the liner is 8 ... 10% of the height of the working surface of the liner, in the cross section of the grooves have a depth and width equal to 0.25 of the minimum thickness of the liner, the maximum distance between adjacent grooves corresponds to the distance between the upper compression m and lower oil scraper piston rings.

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