RU2425999C1 - Ice sleeve assembly - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed sleeve assembly comprises cylinder 1, piston 2 and split compression ring 3 fitted in piston groove 4 with clearance between piston groove bottom and ring inner vertical surface equals that between piston 2 and cylinder wall 1. Besides, ring split width does not exceed clearance between piston 2 and cylinder wall. Thus, thermodynamic clearances are optimised to preserve elastic properties of compression ring and its operating properties.

EFFECT: engine higher output and longer life, reduced fuel and oil consumption.

2 cl, 1 dwg

Description

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

Known cylinder-piston groups of engines with the lowest gas-dynamic losses through guaranteed thermodynamic clearances (Application No. 20022874, Great Britain, 1979; Application No. 60-30457, Japan, 1985; RU 2372506 C1, RU 2372507 C1).

Known cylinder-piston group of an internal combustion engine, adopted for the prototype of the claimed invention, containing a cylinder, piston and split compression ring placed in the piston groove with a gap between the inner vertical surface of the ring and the bottom of the piston groove and the gap in the ring lock (Internal Combustion Engines. Ed. A S.S.Orlina, M.G. Kruglova, M. Mechanical Engineering, 1984, p. 157). The prototype has a significant drawback, namely, that the recommended gap between the bottom of the piston groove and the inner vertical surface of the ring creates an unreasonably large cavity, which, through the guaranteed gap between the lower shelf of the piston groove and the lower end of the ring, is filled with oil, which is removed by the lower end of the ring when moving the piston to the lower position. High-temperature (over 3000 ° C) working gases bursting through gaps into the bottom cavity of the piston groove burn oil that has fallen into these gaps and the cavity. Soot gradually accumulates on the free surfaces of the ring and the piston groove, which cokes under the influence of high temperatures and pressures, the compression ring loses its mobility and, as a result, its working capacity. As a result, this leads to jamming of the piston and engine failure. Moreover, the larger the space between the bottom of the piston groove and the ring, the greater the amount of oxidized oil turns into soot, soot and coke, the more actively the engine resource is reduced. To the greatest extent, this process is typical for diesels of any power. In addition, in known designs, the gaps in the locks of compression rings are subjective in nature, assigned at large intervals, for example, for a KamAZ engine with a cylinder diameter of 120 mm, the gap in the lock is 0.45 + 0.25 mm, while the gap of the compression lock VAZ engine rings with a cylinder diameter of 76 mm are regulated within 0.25 + 0.2 mm (GOST 621-87. Table 6). That is, the minimum allowable clearance in the lock of the KamAZ engine compression ring (0.45 mm) is equal to the maximum, but also allowable clearance in the lock of the compression ring of the VAZ engine (0.45 mm). Moreover, it is known that through a gap in the lock of the compression ring, up to 70% of working gas leaks occur, which significantly affect the technical, economic and environmental characteristics of the engine.

The larger the gap in the ring lock, the more compressed air and then the working gas breaks into the piston groove and further into the crankcase. These are not only large leaks of the working gas, which affect compression, combustion processes of the air-fuel mixture, engine power, but also increased carbon formation in the piston group, and aging of engine oil.

At the same time, different but allowable gaps in the locks of the compression rings installed in the pistons located in two-row engines on opposite sides lead to different triggering of the working pressure in the cylinders and, as a result, to gas-dynamic imbalance of the engine, its vibration and reduction of engine life.

The technical result, the achievement of which the present invention is directed, is to increase the power and resource of the engine, reduce fuel and oil consumption, improve the environmental performance of the engine.

The technical result is achieved by the fact that in the cylinder-piston group of an internal combustion engine containing a cylinder, a piston and a split compression ring located in the piston groove with a gap between the bottom of the piston groove and the inner vertical surface of the split compression ring, it is new that the gap between the bottom of the piston groove and the inner vertical surface of the split compression ring is equal to the gap between the piston and the cylinder wall.

The width of the cut of the compression ring is not greater than the gap between the piston and the cylinder wall.

According to existing recommendations (ICE. Orlin AS M.Mashinostroenie, 1980, p. 87), the clearance between the piston and the cylinder is taken to be 0.04 ... 0.06% of the diameter of the engine cylinder. For example, for a KamAZ engine with a cylinder diameter of 120 mm, the allowable clearance between the piston and the cylinder can be from 0.048 mm to 0.072 mm, i.e. it is more than an order of magnitude smaller than the gap between the bottom surface of the piston groove and the inner vertical surface of the ring, also recommended by the original source. The calculated value of the gap between the piston and cylinder, taking into account the thermodynamic changes in the shape and dimensions of the cylinder and piston, is guaranteed to be necessary and sufficient to maintain the elastic properties of the compression ring and its operability for any thermodynamic changes in the shape and size of parts of the cylinder-compression ring-piston system.

Moreover, the gap between the bottom surface of the piston groove and the inner vertical surface of the ring increases during assembly due to technological deviations, since the diameter of the surface of the bottom of the groove is minus (deviations for the "shaft"), and the surface of the inner diameter of the compression ring is made in positive (deviations for " holes ").

All this indicates the priority of the gap between the piston and the cylinder wall, the value of which, taken also for the gap between the bottom of the piston groove and the inner vertical surface of the compression ring and for the gap in the ring lock, will guarantee the preservation of the elastic properties of the compression ring and its performance with the minimum possible gaps in the cylinder-piston group.

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

The internal combustion engine comprises a cylinder 1, a piston 2, a split compression ring 3 installed in the piston groove 4 so that a guaranteed clearance is provided between the bottom of the piston groove 4 and the inner vertical surface of the ring 3, equal to the gap between the piston 2 and the cylinder wall 1. Section width ring 3 is not greater than the gap between the piston 2 and the wall of the cylinder 1.

The cylinder piston group works as follows.

When moving the piston 2 to the lower position on the “intake” stroke, under the action of inertia and friction forces on the cylinder wall 1, the ring 3 is shifted to the upper flange of the piston groove 4 within the guaranteed thermodynamic clearance between the upper flange of the piston groove 4 and the upper end of the ring 3. At the same time, the ring 3 with the lower end removes oil from the cylinder wall 1, which fills this gap and the gap between the bottom of the piston groove 4 through the gap formed on this step between the lower end of the ring 3 and the lower shelf of the piston groove 4 Cored oil vertical face of the ring 3. In this case, the minimum possible width of the ring section 3 which is smaller than the gap between the piston 2 and the cylinder wall 1, leaves little on the cylinder wall 1 traces of oil.

When moving the piston 2 to the upper position on the working stroke, the “compression” compression ring 3, under the action of the pressure of compressible air and friction forces against the cylinder wall 1, is pressed to the lower shelf of the piston groove 4, displacing the part of the oil located in the gap between the lower end of the compression ring 3 and the lower flange of the piston groove 4, into the bottom cavity of the piston groove 4, into the opened gap between the upper end of the compression ring 3 and the upper flange of the piston groove 4 and then through the gap between the piston 2 and the cylinder wall 1 in combustion moderation. This is the effect of the “pumping” effect of motor oil, which usually accompanies the operation of normal compression rings. And the more these gaps, the greater the oil consumption for waste.

At the same time, an insignificant amount of compressible air breaks through the minimum possible section width of the ring 3, which does not significantly affect the working pressure and the calculated value of the coefficient of excess air.

When the piston 2 is moved to the lower position on the “stroke” stroke under excessive pressure, the ring 3 continues to be pressed against the lower shelf of the piston groove 4. Through the gap between the upper end of the ring 3 and the lower shelf of the piston groove 4, the high-temperature working gas breaks into the bottom cavity of the piston grooves 4, limited by the bottom of the piston groove 4 and the inner vertical surface of the ring 3, oxidizes the oil particles therein. The process of accumulation of soot and coke on the free surfaces of the compression ring 3 and the piston groove 4 takes a longer time, which accordingly affects the increase in engine life and lower oil consumption for burning, improving the environmental performance of the engine.

In this case, the minimum possible cut width of the compression ring 3 (the gap in the lock of the compression ring 3) limits the breakthrough into the piston groove 4 and further into the crankcase of the engine of high-temperature working gases. A small amount of bursting working gases practically does not affect changes in the quality of oil and its aging.

When moving the piston 2 to the upper position on the working cycle "release" the minimum required clearance between the ring 3 and the piston 2 and the width of the cut of the ring 3 provide a more complete discharge of exhaust working gases.

Minimization of thermodynamic clearances to the necessary and sufficient values, providing conditions for maintaining the elastic properties of the compression ring and its performance under any thermodynamic changes in the shape and size of parts of the cylinder-compression ring-piston system, will significantly increase engine power and life, and reduce fuel and oil consumption will improve the environmental performance of the engine.

Claims (2)

1. The cylinder-piston group of an internal combustion engine comprising a cylinder, a piston and a split compression ring located in the piston groove with a gap between the bottom of the piston groove and the inner vertical surface of the split compression ring, characterized in that the gap between the bottom of the piston groove and the inner vertical surface of the split compression rings is equal to the gap between the piston and the cylinder wall. 2. The cylinder-piston group of an internal combustion engine according to claim 1, characterized in that the sectional width of the compression ring is not greater than the gap between the piston and the cylinder wall.