RU2177569C2 - Multipiece piston ring - Google Patents

Abstract

FIELD: mechanical engineering; internal combustion engines, compressors and other piston machines. SUBSTANCE: multipiece piston ring has all-curved tangential expander and plate coiled rings made from rectangular section metal bands with rounded off edges whose width B and b corresponds to relationships b/B=0,45±0,15 thickness corresponds to relationship h/H = 0,85±0,15 and end stops of all-curved tangential expander are arranged at angle α of 95-120 deg relative to radial support flanges. EFFECT: improved control efficiency of piston ring, provision of reliability and long service life of cylinder-piston group of engine, reduced consumption of fuel and oil and pollution of ambient atmosphere. 2 cl, 8 dwg

Description

 The invention relates to mechanical engineering, namely to engine building, and can be used as a piston ring in internal combustion engines, compressors and other reciprocating machines.

 High demands are placed on piston rings for durability, ensuring a minimum oil consumption for burning, which determines the harmful emissions of solid particles into the atmosphere, gas breakthroughs and friction losses, which reduce fuel consumption. The number of piston rings on the piston should be minimal.

To meet these requirements, piston ring designs must have the following properties:
- high elasticity, flexibility, adaptability, ensuring the fit of the ring to the wall of the cylinder liner with distortions of its geometric shape;
- soft (gentle) characteristic of the spring of the tangential expander, providing a slight drop in the elastic force during wear of the friction elements of the ring;
- high resistance to the relaxation process in a non-stressed state at temperatures up to 300 ^o C;
- good collectability on the piston and together with the piston in the cylinder liner;
- reliable sealing of the working space between the piston, cylinder and block head.

 Known designs of composite piston rings (see inventions according to copyright certificate N 303448, IPC F 02 F 5/00, publ. 1971, according to the patent of the Russian Federation N 2028485 C1, F 02 F 5/00, publ. 1995), which contain plate twisted rings and an integral curved tangential expander made of metal tapes of rectangular cross section with rounded edges.

 These designs of composite piston rings do not fully meet the requirements imposed on them, since the metal tapes of which the plate rings and the tangential expander are made, wound around the rib in their width and thickness, do not always agree in terms of rigidity (elasticity) with the force transmitted through the end stops from tangential expander to plate rings.

 In addition, due to the excessive rigidity of the metal strip from which the tangential expander is made, the force on the plate rings is not transmitted through all the end stops, which reduces the wear resistance of the end stops and at the same time does not ensure the fit of the plate rings to the cylinder wall with the reciprocating piston in internal combustion engine.

 Known composite piston oil scraper ring (see the invention according to the application of France N 2525282, CL F 02 F 5/00, publ. 1983), which is the closest to the invention in terms of technical nature and the achieved effect and therefore taken as a prototype.

 It also consists of twisted plate rings and an integral curved tangential expander made of metal tapes of rectangular cross section with rounded edges.

Such a constructive implementation of a composite piston ring most fully meets the requirements for its use in the operation of an internal combustion engine, but the necessary ratios of metal tapes in width and thickness of which plate spiral rings are made and a whole-curved tangential expander are not always consistent in optimal stiffness with the force transmitted from the tangential expander to the plate rings through the end stops, which does not guarantee the fit of the plate rings to the cylinder wall. In addition, the end stops of the tangential expander are made at an angle of 90 ^o with respect to the radial support flanges, which reduces the efficiency of pressing the plate rings to the ends of the piston groove in the axial direction and, as a result, sealing the piston from the combustion chamber.

 The aim of the invention is to increase the efficiency of a composite piston ring by ensuring a guaranteed fit of the plate rings both individually and in the bag in the radial direction to the cylinder wall and in the axial direction to the ends of the piston groove during its reciprocating movement relative to the cylinder during engine operation.

 This goal is achieved by the fact that in a composite piston ring for internal combustion engines, twisted plate rings and an integral curved tangential expander are made of metal tapes of rectangular cross section with rounded edges, while the width b and thickness h of the metal tape from which the whole curved tangential expander is made; the width B and the thickness H of the metal strip from which the plate twisted rings are made must correspond to the ratios b / B = 0.45 ± 0.15 and h / H = 0.85 ± 0.15.

In this case, as shown by experimental work and practical experience in production and operation, optimal stiffness of the plate twisted rings and the integral curved tangential expander is ensured, which guarantees the adhesion of the plate twisted rings to the cylinder wall with the minimum necessary effort to press them through the end stops of the tangential expander. At the same time, the end stops of the integral curved tangential expander, transmitting the force to the twisted plate rings, are made with respect to the radial support flanges at an angle α from 95 to 120 ^o with the aim that part of the force transmitted from the whole curved tangential expander is used to compress the plate twisted rings in the axial direction to the ends of the piston groove.

 Such structural designs in a composite piston ring make it possible to securely press both individual and packet twisted plate rings with the minimum necessary force to the ends of the piston groove and cylinder wall, ensuring that the plate rings fit during the reciprocating movement of the piston.

 In the known technical solutions, no signs are found that are similar to the distinguishing features of the claimed invention.

 In FIG. 1 shows a cross-section of a composite piston ring assembly in a piston groove in working condition with an integral curved V-shaped tangential expander.

 FIG. 2 is a part of the composite piston ring of FIG. 1, depicted in perspective.

 In FIG. 3 shows a cross-section of a composite piston ring assembly, in a piston groove in working condition, with an integral curved W-shaped tangential expander.

 FIG. 4 is a part of the composite piston ring of FIG. 3, depicted in perspective.

 In FIG. 5 shows a cross-section of a composite piston ring assembly, in the piston groove in operating condition, with a T-shaped tangential expander with a curved radial support flanges relative to each other in a free state.

 In FIG. 6 is a part of the composite piston ring of FIG. 5, depicted in perspective.

 In FIG. 7 shows a cross-section of a composite piston ring assembly in the piston groove in working condition with a V-shaped tangential expander with a gap between the radial shelves of not more than the thickness of the metal strip.

 In FIG. 8 is a part of the composite piston ring of FIG. 7, depicted in perspective.

The composite piston ring for an internal combustion engine contains twisted plate rings 1 and 2 and a one-piece curved tangential expander 3 made of metal tapes of rectangular cross section with rounded edges in the ratio b / B = 0.45 ± 0.15 and h / H = 0.85 ± 0.15. In this case, end stops 4 and 5, pressing plate twisted rings, are made at an angle α within 95. ..120 ^o to the radial support shelves 6 and 7. Depending on the height of the piston groove, the combustion process (diesel, carburetor, etc.) and the number of revolutions of the crankshaft of the engine, various combinations of the package (number) of plate rings in a composite piston ring are possible, but the ratio of the width and thickness of the tape from which they are made to the width and thickness of the tape from which the whole-curved tangential expander is made correspond to b / B = 0.45 ± 0.15 and h / H = -0.85 ± 0.15.

 The piston composite ring operates as follows. In an internal combustion engine with a reciprocating motion of the piston, the twisted plate rings 1 and 2 are pressed by the end stops 4 and 5 and the radial support flanges 6 and 7 of the integral curved tangential expander 3 in the radial direction to the cylinder wall 8, and in the axial direction to the end surfaces 9 and 10 piston grooves.

 As a result of using the invention, the economic effect is expected from a decrease in the number of rings on the piston, reduction in fuel consumption, engine oil for waste and harmful emissions into the environment, as well as an increase in the durability of the cylinder-piston group of the internal combustion engine.

Claims (2)

 1. A composite piston ring for an internal combustion engine containing plate rings and a spring tangential expander made integrally curved from metal tapes of rectangular cross section with rounded edges, characterized in that the plate rings and the tangential expander are made of metal tapes, the widths of which B and b correspond to the ratio b / B = 0.45 ± 0.15, and the thickness H and h to the ratio h / H = 0.85 ± 0.15. 2. The ring according to claim 1, characterized in that the end stops of the tangential expander are made with respect to the radial support flanges at an angle α in the range of 95 - 120 ^o .

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