RU2412367C1 - Piston seal for internal combustion engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: piston groove (5) includes stepped working rings (3) and (4), facing each other with stepped surfaces, besides, area of working surface of upper ring (3) is more than area of its internal vertical surface, and area of working surface of lower ring-expander (4) is less than area of its inner vertical surface, at the same time gaps in locks are arranged in direction of axis of piston finger. Both rings contact each other with their inner surfaces, at the same time area of surface of upper end of upper working ring (3) is arranged as equal to total area of internal vertical surfaces of both rings (3) and (4). Invention provides for higher efficiency of seal between piston and cylinder, reduced mechanical, gas-dynamic and thermal losses, increased efficiency and resource of engine, reduced consumption of fuel and oil, improvement of ecological characteristics of engine.

EFFECT: improved efficiency and resource of internal combustion engine, reduced consumption of fuel and oil, improved ecological characteristics of engine.

4 cl, 3 dwg

Description

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

Known piston seals, consisting of two working rings installed in one piston groove (US 1396620, F16J 9/00, 1921; JT 534645 A, 10/20/1955; US 2228495 A, 01/14/1941).

A piston seal for an internal combustion engine is known, comprising upper and lower working rings of the same L-shaped design placed in one piston groove, so that their locks are 180 ° offset from each other and the ends are mutually delayed from going out, with a gap in the lock of one ring it is blocked in the radial and axial direction by another ring closest in technical essence and taken as a prototype (K. English. Piston rings. T.1. Translation from German. M.: State scientific and technical e publishing house of engineering literature. 1962. P. 466. Fig. 370).

The prototype has a significant drawback, which is that the task of closing the gap in the lock of one ring with another ring in the axial and radial directions, if it can be solved, as the author recommends, for "large engines, primarily marine, steam engines, compressors and hydraulic mechanisms ”in a single type of production, such designs cannot be used for medium and small engines in large-scale and mass production due to their low technology. In addition, the smaller working surface of the upper ring is subject to greater thermal and mechanical stresses than the working surface of the lower ring. It wears out faster, and given that the wear of the working surface of the lower ring is less, and the piston has the ability to swing on the piston pin and wear out the working surface of the upper ring even more, a gap forms between the cylinder and the cylinder wall, since the step of the lower ring limits radial displacement of the upper ring to the wall, impairing its sealing properties.

In addition, for "large" engines in the presence of excess pressure above the piston at the working strokes, the "compression" and "working stroke" similar designs are inoperative, since the surface areas of the upper ends of the upper rings are usually larger than the areas of vertical internal surfaces, which is affected by the working gas. Such compression rings lose their elasticity and mobility relative to the piston. “The compression ring loses its functions, becomes inoperative, becoming similar to the piston structural element on the most critical engine cycle cycles” (patent RU 2341671 C2, 12/20/2008, Bull. No. 35). In addition, during operation, as the working rings wear, they lose their elastic qualities, especially at the “release” working cycle, when there is no additional pressure in the piston groove, thereby impairing the cleaning of the cylinder from the combustion products of the air-fuel mixture, soot and soot, reducing the amount of clean air drawn in at the “intake” stroke.

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

The technical result is achieved in that in a piston seal for an internal combustion engine containing upper and lower stepped working rings facing each other with stepped surfaces placed in one piston groove, the new is that the area of the working surface of the upper ring is larger than the area of the working surface of the lower ring-expander, while the area of the upper end of the upper ring is equal to the sum of the areas of the inner vertical surfaces of the rings.

In the piston seal for the internal combustion engine, the working rings are arranged so that the cuts of the locks lie in the direction of the axis of the piston pin and are rotated 180 ° with respect to each other.

In a piston seal for an internal combustion engine, the middle surfaces of the steps are made at 90 ° or at an angle α to the upper end of the upper ring and the lower end of the lower ring.

In the piston seal for the internal combustion engine in the piston groove above the upper compression ring there is a stepped elastic split ring with a gap relative to the engine cylinder and a stop in the inner vertical surface of the annular collar made on the upper shelf of the piston groove.

Thus, the upper working ring and the lower working ring-expander constitute one complete piston ring.

Figure 1 shows a partial section of an internal combustion engine with stepped working rings facing each other stepped surfaces, while the middle surfaces of the steps are made at an angle of 90 °.

Figure 2 shows a partial cross section of an internal combustion engine with stepped working rings, over which an additional stepped ring is located.

Figure 3 presents a partial section of an internal combustion engine with stepped working rings facing each other stepped surfaces, while the middle surfaces of the steps are made at an angle α.

The internal combustion engine comprises a cylinder 1, a piston 2, an upper working ring 3 and a lower working ring-expander 4 installed in the piston groove 5, and the area of the working surface of the upper ring 3 is larger than the area of the working surface of the lower ring-expander 4, while the area of the upper end the upper ring 3 is equal to the sum of the areas of the inner vertical surfaces of the rings 3 and 4. The working rings 3 and 4 are located so that the cuts of the locks lie in the direction of the axis of the piston pin and are rotated 180 ° with respect to each other.

In the piston groove above the upper working ring 3, a stepped elastic split ring 6 is installed with a gap relative to the cylinder 1 and with a stop as a step in the inner vertical surface of the annular collar made on the upper shelf of the piston groove 5.

The middle surfaces of the steps of the upper working ring 3 and the steps of the lower expander ring 4 can be made at 90 ° or at an angle α with respect to the upper end of the upper working ring 3 and the lower end of the lower expander ring 4.

The piston seal operates as follows.

When the piston is moved to the upper position on the working stroke, “compression” through the guaranteed thermodynamic gap between the upper flange of the piston groove 5 and the upper end of the working ring 3, the compressed air breaks into the bottom cavity of the piston groove 5. The generated pressure in the piston groove 5 acts on the surrounding surfaces with forces directly proportional to the areas of these surfaces. The elastic qualities of the working ring 3 and the lower expander ring 4 are maintained due to the balance of gas-dynamic forces acting on the surface of the rings in the axial F _o and radial direction F _rad . To fulfill this condition, the surface area of the upper end face of the upper working ring 3 is equal to the total surface area of the inner vertical surfaces of the rings 3 and 4. Such dynamics is maintained at any excess pressure above the piston both at the “stroke” stroke and partially at the “release” stroke ".

When moving the piston to the lower position on the working stroke, the “inlet” in the cylinder can only be atmospheric pressure, which does not have any effect on the work of the rings, which is carried out only due to its elastic qualities. During operation, due to wear, the upper working ring 3 loses its elastic qualities, which are compensated by the lower working ring-expander 4, which retains its elastic qualities to a greater extent. Thus, the working life of both rings 3 and 4 is prolonged, the required intake of the calculated amount of fresh air is provided during the entire life of the piston seal.

The smaller area of the working surface of the lower expander ring allows it to be used more quickly along the cylinder liner, choosing possible technological gaps between the middle surfaces of the steps and increasing the sealing properties of the assembly ring. After running in, ring 4, while remaining working, performs the functions of an expander uniformly, regardless of the wear of rings 3 and 4, pressing the upper working ring 3 against the wall of cylinder 1.

After the contact of these surfaces, the upper working ring 3 restrains the wear of the lower expander ring 4, the working surface of which wears out together with the working surface of the upper working ring 3. In addition, through the gap in the lock of the lower part of the lower working ring-expander 4, a limited part that burst into the bottom the cavity of the piston groove 5 of the compressible air pressure is throttled into the gap between the piston 2 and the cylinder 1 and further into the crankcase. The lower the height of the working part of the lower expander ring 4, the smaller the passage section, and, therefore, a smaller part of the pressure will break through this reduced gap. Reducing the area of the bore of the gap in the lock of the lower ring likewise affects the reduction of oil that is removed by the lower end of the lower expander ring 4 from the cylinder wall 1 when the piston 2 is moved to the lower position on the “intake” and “working stroke” strokes in the piston groove 5 , thereby reducing oil consumption for waste.

The location of the cuts of the locks of the working rings in the direction of the axis of the piston pin and at 180 ° relative to each other allows you to block the direct breakthrough of working gases from above at the “compression” and “working stroke” and engine oil, removed from the cylinder wall with the lower end of the lower ring 4 moving the piston to the lower position on the “stroke” and “inlet” strokes.

The stepped ring 6 overlaps the guaranteed gap between the upper end face of the upper working ring 3 and the upper shelf of the piston groove 5, significantly limiting the breakthrough of compressible air at the “compression” stroke, working gases at the “stroke” cycle, as well as soot and soot at the “discharge” cycle .

In those engines in which it is impossible to use a stepped ring 6 (low-power engines with a small cylinder diameter), it is advisable to use a design with inclined middle surfaces of the steps. The own elastic force of the lower working ring-expander 4, acting on the extrusion and increasing the pressing force of the upper ring 3 to the wall of the cylinder 1, is displayed on the inclined contact surfaces of the steps on the horizontal (radial) component F _rad and the axial component F _o . The radial component F _rad elastic force of the lower working ring 4 compresses the upper working ring 3 against the cylinder wall 1, and the axial component F _o the elastic force of the lower ring 4 compresses the upper ring 3 to the upper flange of the piston groove 5, eliminating the guaranteed thermodynamic clearance between the upper end face of the upper working ring rings 3 and the upper flange of the piston groove 5. In this case, the gas-dynamic forces arising from the pressure of the gases breaking into the piston groove 5 greatly enhance this effect of the lower working ring 4 on the upper working ring 3, performing the functions of an expander and increasing the sealing qualities of the structure.

Since the working surfaces 3 and 4 mainly wear out on the surface located in the area of the ring lock, it is advisable to place them so that the cuts of the locks are located in the direction of the axis of the piston pin and are rotated 180 ° with respect to each other when installing the rings on the piston 2 . This will reduce the wear of the working rings 3 and 4 and cylinder 1, will exclude a direct breakthrough of working gases from the cylinder 1 through the gaps in the locks of the working rings 3 and 4.

The piston seal, simple in design, technologically advanced in manufacture and operation, will significantly increase the efficiency of the seal between the piston and the cylinder, reduce mechanical, gas-dynamic and thermophysical losses, increase engine power and life, reduce fuel and oil consumption, and improve the environmental performance of the engine.

Claims (4)

1. A piston seal for an internal combustion engine, comprising upper and lower stepped working rings facing each other with stepped surfaces located in one piston groove, characterized in that the working surface area of the upper ring is larger than the working surface area of the lower expander ring, the area of the upper end of the upper ring is equal to the sum of the areas of the inner vertical surfaces of the rings. 2. A piston seal for an internal combustion engine according to claim 1, characterized in that the cuts of the locks of the working rings lie in the direction of the axis of the piston pin and are rotated 180 ° with respect to each other. 3. A piston seal for an internal combustion engine according to claim 1, characterized in that the middle surfaces of the steps are made at 90 ° or at an angle α to the upper end of the upper ring and the lower end of the lower ring. 4. A piston seal for an internal combustion engine according to claim 1, characterized in that a stepped elastic split ring is installed in the piston groove above the upper compression ring with a clearance relative to the engine cylinder and a stop in the inner vertical surface of the annular collar made on the upper shelf of the piston groove .

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