RU2535514C1 - Oil wiper piston device for internal-combustion engine - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: in piston groove a top trapezoidal oil wiper ring, trapezoidal spacer and bottom trapezoidal oil wiper ring are installed, ay top ends face of the bottom trapezoidal oil wiper ring the radial slots are made to drain oil removed from the cylinder wall by top ring to the near-bottom cavity of the piston groove and further via the cone holes to the internal piston cavity. Work surfaces of the oil wiper rings are profiled such that surplus oil is removed from the cylinder wall during the piston movement to the bottom position only, and on the cylinder wall a minimum necessary thickness of the hydrodynamic lubricating layer is created ensuring minimum mechanical losses for friction of the piston rings and minimum engine oil consumption for burn-off losses.

EFFECT: improved reliability of the oil wiper piston device.

2 cl, 1 dwg

Description

The invention relates to mechanical engineering, and specifically to the design, manufacture and operation of internal combustion engines.

Known oil scraper piston devices of internal combustion engines containing oil scraper rings and expanders of various designs (Application No. 53-22204, Japan, 1978; Application No. 59-20859, Japan, 1984; GOST R 53843-2010; RU patent No. 2447307, IPC F02K F5 / 00, F16J 9/20, published April 10, 2012).

It is known oil scraper ring of an internal combustion engine (patent RU No. 2447307, IPC F02K F5 / 00, F16J 9/20, publ. 04/10/2012) containing scraper elements made in the form of a one-sided trapezoid, and an expansion ring located between them, closest to declare and taken as a prototype. However, in the known device, the location of the radial grooves on the expansion ring limits its minimum size, since during the operation of the engine high-frequency vibration loads act on the expansion ring, causing fatigue stresses to appear at the location of the grooves, leading to destruction of the ring itself. Therefore, such designs are advisable to use in powerful engines with relatively large cylinder diameters.

The technical result, the achievement of which the present invention is directed, consists in the universality of the oil scraper piston device, increasing its efficiency, reliability, increasing the resource, reducing the consumption of motor oil, improving the environmental characteristics of the engine.

The technical result is achieved in that in the oil scraper piston device of an internal combustion engine containing the upper and lower trapezoidal oil scraper rings installed in one piston groove and an expansion ring located between them, radial grooves are made on the upper end of the lower oil scraper ring.

The angle of inclination of the lower end of the expansion ring and the upper end of the lower oil scraper ring is greater than the self-braking angle 12 °.

The drawing shows a partial section of an internal combustion engine.

The internal combustion engine contains a cylinder 1, a piston 2, a piston groove 7, in which an upper oil scraper ring 3, an expansion ring 4 and a lower oil scraper ring 5 are installed, at the upper end of which there are radial grooves (6) for draining oil removed from the cylinder wall ( 1) the upper ring (3), into the bottom cavity of the piston groove (7) and then through the conical holes (8) into the internal cavity of the piston (2). The working surfaces of the oil scraper rings (3) and (5) are profiled so that excess oil is removed from the cylinder wall (1) only when the piston (2) moves to the lower position, and the minimum required thickness of the hydrodynamic lubricating layer is formed on the cylinder wall (1), providing minimal mechanical friction losses of the piston rings and minimum consumption of engine oil for waste.

Oil scraper piston device operates as follows.

When the piston 2 moves to the lower position, the lower oil scraper ring 5 removes the bulk of the oil from the cylinder wall 1, the upper oil scraper ring 3 finally forms the minimum required oil film thickness on the cylinder wall 1, removing excess oil remaining on the wall through the radial grooves 6 into the bottom piston cavity grooves 7 and further through conical openings 8 into the internal cavity of the piston 2. Conical drain openings 8 improve the removal of oil from the piston groove 7 and counteract the suction of oil from the internal s cavity at the working piston 2 inlet cycle when above the piston 2 and the piston groove in the gaps 7 formed underpressure. When the engine warms up, the piston 2 first heats up, respectively, the width of the piston groove 7 increases, under the action of its own elastic forces, the expansion ring 4 is expanded and displaced in the direction of the cylinder wall 1, acts on the lower ring 5, pressing it to the lower shelf of the piston groove 7 In turn, the friction forces of the working surface of the lower ring 5 against the wall of the cylinder 1 and the hydrodynamic force of the oil acting on the ring 5 contribute to the formation of a gap between the lower shelf of the piston groove 7 and the lower Tzom lower ring 5. In order to eliminate the occurrence of this gap, which opens the way oil entering the piston groove 7, the elastic force of the expansion of the ring should be more opposing forces. In the process of heating the cylinder 1, its diameter increases, the oil scraper ring 5 unclenches, the effect on the expansion ring 4 is weakened, which also unclenches, moves in the direction of the cylinder wall 1, preventing a gap between the lower flange of the piston groove 7 and the lower end of the ring 5. Guaranteed wedging of the system “upper ring 3 - expansion ring 4 - lower ring 5” at all engine operating modes is provided by the calculated gap between the expansion ring 4 and cylinder wall 1. This condition performed if the angle of inclination of the lower end of the expansion ring 4 and, accordingly, the upper end of the lower oil scraper ring 5 is greater than the self-braking angle of 12 °. When the piston 2 moves to the upper position, the profiled working surfaces of the oil scraper rings 3 and 5 run into the oil film, leaving it unchanged. Thus, the minimum necessary oil layer on the wall of the cylinder 1 is ensured, the oil scraper piston device is stable at all engine operating modes.

When turning off and cooling the engine, first of all, cylinder 1 is cooled, its diameter is reduced, the upper 3 and lower 5 oil scraper rings are compressed, which, acting on the expansion ring 4, displace it in the direction of the axis of cylinder 1, the whole system takes up its original position. To implement this recovery process to a greater extent than at the beginning, it is necessary to have an inclination angle of the ends of the expansion ring and the lower oil scraper ring of more than 12 °.

The design of the oil scraper piston device provides the minimum required thickness of the lubricating film on the cylinder wall, significantly increases the life of the engine oil with a minimum consumption of fumes, reducing harmful and polluting impurities in the exhaust gases.

Claims (2)

1. Oil scraper piston device of an internal combustion engine, comprising upper and lower trapezoidal scraper rings installed in one piston groove and an expansion ring located between them, characterized in that radial grooves are made on the upper end of the lower scraper ring. 2. Oil scraper piston device of an internal combustion engine according to claim 1, characterized in that the angle of inclination of the lower end of the expansion ring and the upper end of the lower oil scraper ring is greater than the self-braking angle 12 °.