Gasoline engine piston ring group for racing car

Abstract

The utility model discloses a gasoline engine piston ring set for racing cars, the piston ring set is composed of three rings which are respectively a top ring, a second ring and a combined oil ring from top to bottom, the combined oil ring is a steel belt combined oil ring, the steel belt combined oil ring comprises a wave-shaped bushing ring and two scrapers, and the wave-shaped bushing ring and the scrapers are arranged on the top ring and the second ring respectively. A wear-resistant protective layer is applied to the outer circular surface of the top ring, 12-18 grooves which are uniformly distributed, face the circle center and penetrate through the whole radial thickness are formed in the upper end face of the top ring in the circumferential direction, the radius of each groove is 0.75-1.25 mm, and the depth of each groove is 1 / 4 + / -0.05 mm of the ring height; the top ring and the combined oil ring are made of steel materials, and the second ring is made of nodular cast iron materials. High-pressure fuel gas can quickly enter the inner circle face of the top ring through the groove in the upper end face of the top ring, the attaching capacity of the top ring and an air cylinder is improved, the whole top ring has the stable ring set performance and the stable engine oil consumption level, and the gas sealing capacity and the power output of a gasoline engine for a racing car are met.

Description

Technical Field

[0001] The utility model relates to a gasoline engine piston ring set, in particular to a gasoline engine piston ring set for racing cars, and belongs to the technical field of automobile accessories. Background Art

[0002] The piston ring plays the role of sealing high-pressure gas, controlling oil consumption and conducting heat in the internal combustion engine. The piston ring assembly is generally composed of three rings, from top to bottom, namely the top ring, the second ring and the oil ring. The top ring mainly plays the role of sealing high-pressure gas, the oil ring mainly plays the role of controlling oil consumption, and the second ring plays the role of assisting the top ring to seal the gas and assisting the oil ring to control oil consumption.

[0003] As the seal of the engine combustion chamber, the piston ring must fully seal the high-pressure gas in the combustion chamber. Otherwise, the downward leakage of high-pressure fuel gas will not only cause a large power loss in the engine, but also cause the lubricating oil in the crankcase to be contaminated and deteriorate due to the high temperature of the blowby gas, greatly reducing the performance of the entire machine.

[0004] For the top ring, on the one hand, its own elastic force makes its outer circle surface fit closely with the cylinder wall to produce a sealing effect. On the other hand, the air pressure entering the inner circle surface of the ring through the gap between the ring and the end face of the ring groove further increases the thrust of the ring on the cylinder wall, thereby improving the fit and sealing effect of the ring and the cylinder wall. When the outer circle seals well, the sealing effect of the end face of the ring and the ring groove will also be guaranteed, thereby achieving a good air sealing function.

[0005] The maximum speed of a household car engine is generally between 6000 and 7000 r / min, but for a racing engine that pursues high speed and high power output, the speed exceeds 10,000 r / min, and the maximum speed of an F1 racing car is even close to 20,000 r / min.

[0006] It has been found that the blowby volume of high-speed engines used in racing cars has increased significantly. This is because the high-pressure gas does not have time to pass through the gap between the ring and the end face of the ring groove to enter the inner circle of the ring. The ring is directly pushed open in the inner circle direction by the gas pressure on its outer circle surface, and there is a situation where it is instantly separated from the cylinder wall. There is also a technical solution that adds a groove to the upper end face of the ring groove to form a pressure channel to increase the gas pressure entering the inner circle of the ring and improve the sealing effect, but there will be carbon deposits in the groove and thus form a hot spot to damage the piston. There is also a technical solution that drills a through hole on the piston to allow the gas to directly pass to the bottom of the top ring groove to increase the thrust of the top ring on the cylinder wall and thus improve the sealing effect, but this technical solution may reduce the reliability of the piston, and the through hole may also be blocked by carbon deposits and lose its function. Utility Model Content

[0007] Purpose of the utility model: The purpose of the utility model is to provide a racing gasoline engine piston ring set with stable ring set performance and engine oil consumption level in order to meet the sealing capacity and power output of racing gasoline engines.

[0008] Technical solution: The utility model discloses a piston ring set for a gasoline engine for racing cars, wherein the piston ring assembly is composed of three rings, which are respectively a top ring, a second ring and a combined oil ring from top to bottom. The combined oil ring adopts a steel belt combined oil ring, and the steel belt combined oil ring comprises a corrugated liner ring and two scrapers. A wear-resistant protective layer is applied to the outer cylindrical surface of the top ring, and 12 to 18 grooves are evenly distributed on the circumference of the upper end surface of the top ring and are oriented toward the center of the circle and penetrate the entire radial thickness. The radius of the groove is 0.75 to 1.25 mm, and the depth of the groove is 1 / 4 ± 0.05 mm of the ring height. The top ring and the combined oil ring are made of steel, and the second ring is made of ductile iron.

[0009] Furthermore, the top ring is made of chromium-silicon alloy steel, and the wear-resistant protective layer on the outer circumferential surface of the top ring is a DLC or PVD coating.

[0010] Furthermore, the outer circumferential surface of the top ring is in a symmetrical barrel surface shape or an asymmetrical barrel surface shape.

[0011] Furthermore, the top ring is provided with a chamfer at the upper edge of the inner circle.

[0012] Furthermore, the outer circles of the two rings are conical surfaces with nose-shaped steps.

[0013] Furthermore, the lower edges of the inner circles of the two rings are provided with chamfers or steps.

[0014] Furthermore, the thickness of the DLC coating is greater than 0.01 mm, preferably 0.015 to 0.025 mm, and the hardness of the DLC coating is HV1800. 0.025 Above, preferably HV2000 0.025 ~HV3500 0.025 The thickness of the PVD coating is 0.02 mm or more, preferably 0.025 to 0.040 mm, and the hardness of the PVD coating is HV1200. 0.05 ~HV1800 0.05 .

[0015] Furthermore, the nominal contact pressure of the combined oil ring on the cylinder wall is 0.9-1.3 MPa.

[0016] Furthermore, the liner ring is made of austenitic stainless steel, the scraper blade is made of carbon steel, and the liner ring is nitrided to have a surface hardness of 900-1500 HV. 0.1The depth of the nitriding layer is 0.003 to 0.02 mm, preferably 0.005 to 0.015 mm. A PVD coating is applied to the outer cylindrical surface of the scraper. The thickness of the PVD coating is 0.02 to 0.035 mm. The hardness of the PVD coating is 1200 to 1800 HV. 0.05 The circular wave of the scraper has an ear angle of about 20°.

[0017] Furthermore, the ring heights of the top ring and the second ring are 1.0-1.2 mm, and the ring height of the combined oil ring is 2.0-2.5 mm.

[0018] Beneficial effects: Compared with the prior art, the utility model has the following advantages: 1. The upper end surface of the top ring is provided with a groove, so that the high-pressure gas can quickly enter the inner surface of the ring, which improves the fit between the ring and the cylinder wall and thus improves the gas sealing ability, ensures good power output, and reduces the risk of rapid deterioration of the engine oil due to blowby;

[0019] 2. The DLC or PVD coating applied on the outer surface of the top ring has the characteristics of low friction coefficient. The friction power consumption between the ring and the cylinder wall is low, which is beneficial to power output. In addition, the good self-lubricating performance of the DLC or PVD coating can also effectively prevent the occurrence of cylinder pulling.

[0020] 3. The special design of the outer surface of the second ring makes the second ring have a strong oil scraping ability. The oil scraping ability of the second ring and the oil ring reduces the risk of oil rising and carbon deposition, so that the groove on the upper end surface of the top ring can be kept from being filled with carbon deposition and failure for a long time;

[0021] 4. The top ring and the oil ring are both made of steel, and the second ring is made of ductile iron. Therefore, the ring group has high strength. The piston ring will not break when the racing engine runs at extremely high speeds, and it has good reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the piston ring assembly of the utility model in the piston / cylinder.

[0023] Figure 2 It is a front view of the upper end surface of the top ring of the utility model when it is closed in the cylinder.

[0024] Figure 3 It is a side view of the groove portion of the upper end surface of the top ring of the utility model.

[0025] Figure 4 Schematic diagram of airflow through the top ring (A is a conventional product, B is the utility model).

[0026] Figure 51 are cross sections of the top ring of the utility model in different embodiments (among which, a: a cross section of the top ring with a symmetrical barrel surface shape on the outer circle and no chamfer on the upper edge of the inner circle; b: a cross section of the top ring with a symmetrical barrel surface shape on the outer circle and a chamfer on the upper edge of the inner circle; c: a cross section of the top ring with an asymmetrical barrel surface shape on the outer circle and no chamfer on the upper edge of the inner circle; d: a cross section of the top ring with an asymmetrical barrel surface shape on the outer circle and a chamfer on the upper edge of the inner circle).

[0027] Figure 6 2 are cross sections of the two rings of the utility model in different embodiments (among which, a: a cross section of the two rings without chamfers or steps at the lower edge of the inner circle; b: a cross section of the two rings with chamfers at the lower edge of the inner circle; c: a cross section of the two rings with steps at the lower edge of the inner circle).

[0028] Figure 7 It is an enlarged view of the combined oil ring of the utility model. DETAILED DESCRIPTION

[0029] The technical solution of the utility model is further described below in conjunction with the accompanying drawings.

[0030] The piston ring assembly of the utility model is applicable to a cylinder diameter of 50 to 110 mm, and the positional relationship between the piston 100 and the cylinder wall 200 is as follows: Figure 1 As shown, the piston ring set of the gasoline engine for racing car of the utility model is composed of three rings, which are respectively a top ring 1, a second ring 2 and a combined oil ring 3 from top to bottom. The combined oil ring 3 adopts a steel belt combined oil ring 3, including a corrugated liner ring 32 and two scrapers 31; wherein, the top ring 1 and the combined oil ring 3 are made of steel material, and the second ring 2 is made of ductile iron material.

[0031] like Figure 2-3 As shown, in this embodiment, the top ring 1 is made of chromium-silicon alloy steel material, in accordance with the MC64 grade of ISO6621-3 standard "Internal Combustion Engine Piston Ring Material Specification". The top ring 1 is provided with a closed gap 12, and 12 to 18 evenly distributed grooves 11 are arranged on the circumference of the upper end surface of the top ring 1, which are oriented toward the center of the circle and penetrate the entire radial thickness. The radius of the groove 11 is R0.75 to 1.25 mm, the ring height is h1, and the depth of the groove 11 is 1 / 4 h1 ± 0.05 mm. The nominal ring height h1 of the top ring 1 is 1.0 to 1.2 mm.

[0032] like Figure 4As shown, the arrow is a schematic diagram of the airflow when the high-pressure gas passes through the top ring 1. A is a conventional product, and B is the airflow after the groove 11 is set on the upper end surface of the utility model. It can be seen that the groove 11 on the upper end surface of the top ring 1 allows the high-pressure gas to quickly enter the inner circular surface of the ring, which improves the fit between the ring and the cylinder wall and thus improves the gas sealing ability, ensures good power output, and reduces the risk of rapid deterioration of the engine oil due to blowby.

[0033] like Figure 5 As shown, the outer circle of the top ring 1 is as follows Figure 5 a, 5b symmetrical barrel shape or Figure 5 c. The asymmetric barrel shape of 5d, the upper edge of the inner circle can be set as follows Figure 5 b, 5d, the chamfer 13 is applied with a wear-resistant protective layer 14 on the outer surface. In a specific embodiment, the wear-resistant protective layer 14 is a DLC (Diamond-Like Carbon) or PVD (CrN) coating, preferably a DLC coating. The thickness of the DLC layer is 0.01 mm or more, preferably 0.015 to 0.025 mm, and the hardness of the coating is HV1800. 0.025 Above, preferably HV2000 0.025 ~HV3500 0.025 As another coating solution, the PVD coating thickness is 0.02 mm or more, preferably 0.025 to 0.040 mm, and the coating hardness is HV1200. 0.05 ~HV1800 0.05 .

[0034] like Figure 6 As shown, in this embodiment, the second ring 2 is made of ductile iron material, according to the MC52 grade or MC56 grade of ISO6621-3 standard "Internal Combustion Engine Piston Ring Material Specification", preferably MC52. The surface is phosphating treated, the outer circle has a nose-shaped step cone 21, and there is a contact platform between the cone 21 and the cylinder wall 200, and the nominal ring height h2 is 1.0-1.2 mm. In a specific embodiment, the second ring 2 is provided with a chamfer 22 or a step 23 at the lower edge of the inner circle.

[0035] like Figure 7 As shown, in this embodiment, the combined oil ring 3 is a steel belt combined oil ring 3, according to the ES2 type described in ISO6627 "Internal Combustion Engine Piston Ring Steel Belt Combined Oil Ring", and the circular wave of the support scraper 31 has an ear angle θ of about 20°. The liner ring 32 is made of austenitic stainless steel, according to the MC67 level of ISO6621-3 standard "Internal Combustion Engine Piston Ring Material Specification", and the liner ring 32 is nitrided with a surface hardness of 900-1500HV 0.1The nitriding layer depth is 0.003-0.02 mm, preferably 0.005-0.015 mm. The scraper blade 31 is made of carbon steel, according to the MC68 grade of ISO6621-3 standard "Internal Combustion Engine Piston Ring Material Specification", and the outer cylindrical surface of the scraper blade 31 is coated with a PVD (CrN) coating, the PVD layer thickness is more than 0.01 mm, preferably 0.02-0.035 mm, and the coating hardness is 1200-1800 HV 0.05 The height h3 of the combined oil ring 3 is 2.0-2.5 mm, preferably 2.0 mm.

[0036] In particular, the nominal contact pressure of the combined oil ring 3 on the cylinder wall 200 is between 0.9 and 1.3 MPa, preferably between 0.95 and 1.25 MPa, which is a significant improvement over the conventional value of 0.70 to 1.0 MPa, thereby reducing the oil consumption. The nominal contact pressure is calculated as P = Ft / (d1·h1), which is well known in the industry, wherein:

[0037] P——Nominal contact pressure (MPa)

[0038] Ft——Combined tangential elastic force (N)

[0039] d1——cylinder inner diameter (mm)

[0040] h1——Axial height of scraper (mm).

Claims

1. A racing gasoline engine piston ring assembly, the piston ring assembly is composed of three rings, from top to bottom, respectively, a top ring, a second ring and a combined oil ring, the combined oil ring is a steel belt combined oil ring, the steel belt combined oil ring includes a corrugated liner ring and two scrapers, characterized in that: A wear-resistant protective layer is applied to the outer circumferential surface of the top ring, and 12 to 18 evenly distributed grooves are arranged on the circumference of the upper end surface of the top ring, which are oriented toward the center of the circle and penetrate the entire radial thickness. The radius of the groove is 0.75 to 1.25 mm, and the depth of the groove is 1 / 4 ± 0.05 mm of the ring height. The top ring and the combined oil ring are made of steel, and the second ring is made of ductile iron.

2. The racing gasoline engine piston ring set according to claim 1, characterized in that: The top ring is made of chromium-silicon alloy steel, and the wear-resistant protective layer on the outer cylindrical surface of the top ring is a DLC or PVD coating.

3. The racing gasoline engine piston ring set according to claim 1, characterized in that: The outer circumferential surface of the top ring is in a symmetrical barrel surface shape or an asymmetrical barrel surface shape.

4. The racing gasoline engine piston ring set according to claim 3, characterized in that: The top ring is provided with a chamfer at the upper edge of the inner circle.

5. The racing gasoline engine piston ring set according to claim 1, characterized in that: The outer circles of the two rings are conical surfaces with nose-shaped steps.

6. The racing gasoline engine piston ring set according to claim 5, characterized in that: The lower edges of the inner circles of the two rings are provided with chamfers or steps.

7. The racing gasoline engine piston ring set according to claim 2, characterized in that: The thickness of the DLC coating is above 0.01 mm, and the hardness of the DLC coating is HV1800. 0.025 The thickness of the PVD coating is above 0.02 mm, and the hardness of the PVD coating is HV1200. 0.05 ~HV1800 0.05 .

8. The racing gasoline engine piston ring set according to claim 7, characterized in that: The thickness of the DLC coating is 0.015-0.025 mm, and the hardness of the DLC coating is HV2000. 0.025 ~HV3500 0.025 The thickness of the PVD coating is 0.025 to 0.040 mm.

9. The racing gasoline engine piston ring set according to claim 1, characterized in that: The nominal contact pressure of the combined oil ring on the cylinder wall is 0.9-1.3 MPa.

10. The racing gasoline engine piston ring set according to claim 1, characterized in that: The liner ring is made of austenitic stainless steel, the scraper is made of carbon steel, and the liner ring is nitrided, with a surface hardness of 900~1500HV 0.1 The depth of the nitride layer is 0.003 to 0.02 mm. The outer surface of the scraper is coated with a PVD coating. The thickness of the PVD coating is 0.02 to 0.035 mm. The hardness of the PVD coating is 1200 to 1800 HV. 0.05 The circular wave of the scraper has an ear angle of about 20°.

11. The racing gasoline engine piston ring set according to claim 10, characterized in that: The depth of the nitrided layer is 0.005 to 0.015 mm.

12. The racing gasoline engine piston ring set according to claim 1, characterized in that: The ring heights of the top ring and the second ring are 1.0-1.2 mm, and the ring height of the combined oil ring is 2.0-2.5 mm.

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