Piston second gas ring groove sealing structure

Abstract

This utility model discloses a second piston ring groove sealing structure, including a second piston ring groove and a second piston ring located at the piston head. The second piston ring groove has two metered air inlets or two air outlets, and the second piston ring has an elastic opening and is fitted onto the second piston ring groove. When the second piston ring is open in the cylinder, it remains a fully sealed ring. The piston ring is either a single-layer double-step overlap with a lower outer tangent structure, or a single-layer single-step overlap with a lower outer tangent structure. This utility model achieves good sealing of the piston for the combustion gas, and the sealing degree of the second piston ring does not decrease with wear on the outer surface of the ring. At the same time, the flow channel formed by the second piston ring groove and the piston ring groove achieves flow restriction and guidance control of the combustion gas reaching the ring land and entering the recessed ring land, and achieves uniform oil distribution and oil circulation renewal.

Description

Technical Field

[0001] This utility model relates to the field of engine piston technology, specifically a piston second ring groove sealing structure. Background Technology

[0002] The piston is one of the most important components of an engine, located inside the cylinder. During operation, it needs to reciprocate rapidly with the cylinder. A piston typically has two compression ring grooves and one oil ring groove. Compression rings are fitted into each of the two compression ring grooves, and an oil ring is fitted into the oil ring groove. The main function of the compression ring grooves, compression rings, oil ring grooves, and oil rings is to seal and block gas flow while simultaneously distributing oil to the cylinder wall working surface through the piston's reciprocating motion and scraping off excess oil from the cylinder wall. Current piston compression rings are all flat-cut open designs, installed in the two compression ring grooves. The compression rings rely on their own elasticity and the pressure of the combustion gases to achieve radial and axial sealing of the piston, thus blocking the combustion gases.

[0003] Its working principle is as follows Figure 11 As shown, when the piston and piston rings are installed in the cylinder (cylinder), three gaps are formed between the piston, piston rings and cylinder wall (cylinder wall): end gap, side gap and back gap. That is, the piston ring is not perfectly circular in its free state, and its outer dimension is slightly larger than the cylinder diameter. When the piston ring is installed in the cylinder, under its own elastic force, the outer surface of the ring body is pressed tightly against the cylinder wall to form the first sealing surface. Meanwhile, the high-pressure gas in the combustion chamber passes through the gap between the piston top (firepower) bank and the cylinder wall, and enters the back gap from the upper side gap and end gap of the ring body. This pressure makes the lower bottom surface of the ring body press tightly against the lower side surface of the ring groove, and the outer surface of the ring body press tightly against the cylinder wall to form the second sealing surface.

[0004] The minimum opening clearance of the flat-mouth piston ring, designed to accommodate thermal expansion, results in excessive combustion gas leakage and excessive oil rise during initial installation. During use, as the outer surface of the ring wears and springs outward, the end clearance gradually widens, causing a simultaneous drop in cylinder pressure. More oil rises into the combustion chamber, while more combustion gas leaks into the crankcase. Excessive scavenging of the piston head by the combustion gas causes oil vaporization and excessive shearing, with insufficient buffering, leading to poor lubrication between the outer surface of the ring and the cylinder wall. Under low cylinder pressure, oil participates in combustion, and the carbon deposits and gum generated from incomplete combustion leak down and adhere to the ring grooves, the ring body, and various engine components, forming carbon deposits. As the end clearance of the ring body further widens, the severity of these problems is exacerbated.

[0005] The existing flat-mouth rings have a relatively low sealing degree for the first compression ring, approximately 80% or higher, with a limit of only 90%. The sealing degree for the second compression ring is about 10-20%, and the sealing degree for the oil ring is about 5%. That is, there is still a large airflow between the ring land 2 and the recessed ring land 3, and between the combustion chamber and the crankcase.

[0006] Therefore, the second compression ring groove and compression ring are key air-blocking layers. Some combustion gases (including air and air-fuel mixture) are blocked by this structure. The existing second compression ring is also a flat-cut opening. The open structure during operation has insufficient sealing, which affects the overall piston efficiency, wastes fuel and engine oil, and increases environmental pollution. The formation and adhesion of carbon deposits will eventually lead to piston and piston ring seizure, cylinder scoring, seal failure, and blockage of crankshaft and eccentric shaft oil passages, resulting in crankshaft seizure and shortening engine life.

[0007] Some designs use a joint design, such as patent number 00248108.1, which is used in conjunction with the piston ring groove and cylinder wall. Although this improves airtightness, it only considers complete sealing and does not have a flow guiding structure like this utility model. As a result, the oil is trapped in the piston head and cannot flow back to renew itself, which reduces the lubrication effect, shortens the oil life, and increases the wear of the piston, piston ring and cylinder wall.

[0008] Therefore, innovative improvements were made to the piston's second ring groove and ring structure to further enhance the gas sealing effect, while also providing a piston second ring groove sealing structure that combines oil flow restriction, guidance, and distribution. Utility Model Content

[0009] This invention proposes a second piston ring groove sealing structure to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A piston second ring groove sealing structure includes a second ring groove and a second ring located at the piston head. The second ring has an elastic opening and is fitted onto the second ring groove. The second ring groove has a metering inlet hole or inlet port on its upper side and a metering outlet hole on its lower side. The metering inlet hole or inlet port and the metering outlet hole are connected to the bottom of the second ring groove.

[0012] When the second air ring is opened in the cylinder, it is still a fully sealed ring. It is a single-layer double-step overlap with a lower outer tangent structure, or a single-layer single-step overlap with a lower outer tangent structure. The second air ring is provided with a lower outer tangent structure, which forms an oil distribution cavity.

[0013] The second quantitative air inlet and the second quantitative air outlet are further configured to correspond to the openings of the second air ring:

[0014] When the second air ring is a single-layer double-step joint with a lower outer tangent structure fully sealed ring, since there are no air holes on the upper and lower sides of the joint axis when the ring body is opened in the cylinder, the upper and lower sides of the second air ring groove must be provided with a quantitative air inlet hole 2 and a quantitative air outlet hole 2 respectively.

[0015] When the second air ring is a single-layer single-step overlap with a lower external tangent structure fully sealed ring, since the overlap forms an air inlet two on the upper side when the ring body opens in the cylinder, the upper side of the second air ring groove does not need to be provided with a quantitative air inlet two, while the lower side must be provided with a certain amount of air outlet two.

[0016] It also includes a ring bank above the second gas ring groove, which is equipped with an oil storage structure. Specifically, according to the axial thickness of the ring bank, several rows of oil storage holes are arranged around the ring bank. Taking two rows of oil storage holes as an example, a row of oil storage holes one is arranged at the same radial spacing in the middle of the outer circumference of the ring bank, and a row of oil storage holes two is arranged at the same radial spacing at the lower part of the ring bank near the second gas ring groove. The first and second oil storage holes are arranged in an alternating manner.

[0017] Preferably, the first oil reservoir in the middle of the ring is circular, while the second oil reservoir near the second gas ring groove is arc-shaped. The depth of the first oil reservoir does not exceed the depth of the first gas ring groove, while the depth of the second oil reservoir is 30% to 50% of the depth of the second gas ring groove, and the second oil reservoir is axially connected to the second gas ring groove. The spacing between the openings in the oil reservoir structure is adjusted according to different engine parameters. The first oil reservoir is circular and the second oil reservoir is arc-shaped to facilitate milling, but other shapes can also be used, and no single limitation is made here.

[0018] The increased space created by the outer tangent structure of the ring body, combined with the torsional effect of the ring body and the oil storage structure of the ring land, increases the oil buffer capacity of the ring land and the recessed ring land. This effectively ensures the thickness and uniformity of the oil film on the working surface of the piston ring and cylinder wall, reduces friction between the piston and piston ring and the cylinder wall, and prevents the oil from vaporizing at high temperature and being excessively sheared and failing. This, in turn, ensures the lubrication effect of the oil and extends its service life.

[0019] Preferably, when the second gas ring is a single-layer double-step joint with a lower outer tangent structure and a fully sealed ring, the two open ends of the second gas ring are double-step joint one and double-step joint two, respectively. Double-step joint one and double-step joint two are complementary structures, with their maximum openings meeting at the joint ends. A concave arc hole is provided at the right-angle turn of the upper step of double-step joint one. Through the cooperation of double-step joint one and double-step joint two, when the second gas ring is tightly fitted against the cylinder wall and the lower side of the second gas ring groove under the pressure of the combustion gas, a completely sealed structure is formed, thereby preventing the combustion gas from leaking downwards.

[0020] Preferably, when the second gas ring is a single-layer, single-step overlap with a lower external tangential structure fully sealed ring, both ends of the elastic opening are flat ends near the top surface. The notched interface end and the convex tongue overlap end are both located on the bottom surface of the elastic opening at both ends. The gap between the two flat ends forms the second air inlet. A short tongue end is provided inside the notched interface end near the back side. The notched interface end, the convex tongue overlap end, and the short tongue end cooperate to form a semi-enclosed plug-in sealing structure. An inwardly concave arc hole is provided at the right-angle turn where the notched interface end connects with the short tongue end. Through the cooperation of the notched interface end, the convex tongue overlap end, and the short tongue end, when the second gas ring is tightly attached to the cylinder wall and the lower side of the second gas ring groove under the pressure of the combustion gas, a completely sealed structure is formed, thereby preventing the combustion gas from leaking downward.

[0021] The second gas ring groove has a first gas ring groove above it and an oil ring groove below it. The first gas ring groove is fitted with a fully sealed first gas ring, and the oil ring groove is fitted with an oil ring. The first gas ring groove has a top bank above it, the space between the first gas ring groove and the second gas ring groove is a ring bank, and the space between the second gas ring groove and the oil ring groove is a recessed ring bank.

[0022] Preferably, the right-angle bend of the double-step joint is provided with a concave arc hole, and the right-angle bend where the concave interface end connects to the short tongue end is also provided with a concave arc hole. The concave arc hole facilitates the milling cutter to process the inner right-angle portion of the interface end. At the same time, when the piston enters the power stroke, the arc-shaped concave arc hole can act to buffer and distribute the engine oil, and to steer and turbulent the combustion gas, as well as to buffer and reduce pressure.

[0023] Preferably, the combustion chamber has a valve intake surface and a valve exhaust surface at the top. The position of the piston top circular surface perpendicular to the center of the valve intake surface is designated as 6 o'clock, and the position of the piston top circular surface perpendicular to the center of the valve exhaust surface is designated as 0 o'clock.

[0024] Preferably, a metering air inlet is provided at the 9 o'clock, 0 o'clock, or 3 o'clock position on the upper side of the air ring groove, and a metering air outlet is provided at the 0 o'clock or 6 o'clock position on the lower side of the air ring groove. The metering air inlet and the metering air outlet are positioned in corresponding positions to form a new U-shaped path for the gas and oil to pass vertically. Alternatively, the metering air inlet and the metering air outlet are positioned in staggered positions to form a new arc-shaped extended path for the gas and oil to pass vertically.

[0025] Preferably, the second quantitative air inlet or air outlet and the second quantitative air outlet must be correspondingly set at the 0 o'clock or 6 o'clock position on the upper and lower sides of the second air ring groove. The second quantitative air inlet or air outlet, the second air ring, and the second quantitative air outlet form a U-shaped path for the gas to drive the oil downward and the air and oil to be attracted upward to circulate and renew.

[0026] As the piston moves upward, the second gas ring simultaneously and evenly coats the oil that has been guided to the recessed ring land and the ring land onto the working surface of the cylinder wall.

[0027] Preferably, the size of the second quantitative air inlet and the second quantitative air outlet can be customized according to the requirements of different vehicle engines, so as to achieve customizable control of the amount of gas entering from the piston ring into the recessed piston ring. The amount of gas leakage is not affected by the wear of the piston ring, and a fixed amount of gas flow can be maintained stably for a long time.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention provides a fully sealed structure by setting a double-step interlocking joint in both the longitudinal and transverse directions at the elastic opening of the second piston ring, or by setting a notched interface end and a protruding tongue interlocking joint at the elastic opening of the second piston ring to form a complementary and semi-enclosed fully sealed structure. This ensures that the second piston ring retains sufficient expansion elastic space when blocking gas, and at the same time keeps the expansion and contraction of the openings in an uninterrupted state, so as to completely block the gas. This achieves the goal of blocking most of the gas flowing down to the ring bank at the upper part of the second piston ring, and the sealing degree of the second piston ring does not decrease with the wear of the outer circular surface of the ring.

[0030] Simultaneously, by combining the second quantitative air intake port or the second quantitative air outlet port, a U-shaped path is formed in the second ring groove, which realizes the flow restriction and guidance control of the downward combustion gas and oil, and the upward air and oil. When the piston enters the intake stroke, the oil rises in time and in sufficient quantity and is buffered. When the piston enters the power and exhaust strokes, after the downward combustion gas is purged, the ring land and the recessed ring land still buffer some oil. This effectively avoids too much oil entering the ring land and too much combustion gas leaking into the recessed ring land. It also facilitates the up and down circulation and buffering of oil in the piston head, ensuring the oil supply between the second ring and the cylinder wall working surface.

[0031] The fully sealed structure of the piston ring reduces the pressure, flow rate, and temperature of the combustion gas and engine oil inside and at the bottom of the piston ring groove, improving the efficiency and effect of oil distribution. It completely avoids the problem of excessive leakage during initial installation of existing flat-mouth piston rings, which leads to a continuous expansion of the port as the outer circumference of the ring wears, resulting in a synchronous decline in the sealing effect of the piston ring.

[0032] The lower outer tangent structure on the bottom surface of the piston rings expands the space of the recessed ring land, which is beneficial for the expansion and cooling of the downward-moving combustion gases, further reducing the gas flow rate. It also helps to buffer more engine oil, increasing the adhesion area and speed of the engine oil to the piston rings. The thinning of the outer circular surface of the rings reduces friction with the cylinder wall. Combined with the torsional effect of the thinned rings, this facilitates timely and even distribution of engine oil to the cylinder wall working surface during piston ascent, and more effectively scrapes away excess engine oil from the cylinder wall during piston descent. Attached Figure Description

[0033] Figure 1 This is a schematic reference diagram showing the flow direction of air, mixture or combustion gas (downward) in the piston head when the piston of this invention is in the compression, power, or exhaust stroke.

[0034] Figure 2 A schematic diagram of the piston structure of this utility model;

[0035] Figure 3 Another front view of the piston structure having this utility model;

[0036] Figure 4 This utility model's second air ring is a schematic diagram of a single-layer double-step overlap with a lower outer tangential structure and a fully sealed ring structure;

[0037] Figure 5 This utility model's second air ring is a front view of the joint of a single-layer double-step overlap with an externally cut structure and a fully sealed ring.

[0038] Figure 6 This is a schematic diagram of the bottom surface of the gas ring of the present invention, which is a single-layer double-step overlap with an externally cut structure and a fully sealed ring overlap.

[0039] Figure 7 This utility model's second air ring is a schematic diagram of a single-layer, single-step overlap with an externally tangential structure and a fully sealed ring structure.

[0040] Figure 8 This utility model's second air ring is a front view of the joint portion of a single-layer, single-step overlap with an externally tangential structure and a fully sealed ring.

[0041] Figure 9 This utility model's second air ring is a schematic diagram of the bottom of a single-layer, single-step overlap with an externally tangential structure, forming a fully sealed ring overlap.

[0042] Figure 10 A schematic diagram of an existing oil ring structure;

[0043] Figure 11 A schematic diagram illustrating the existing piston-piston ring clearance;

[0044] Figure 12 This is a schematic diagram of the piston at six points according to this utility model.

[0045] 1. Piston; 2. Ring land; 21. Compression ring one; 22. Compression ring two; 23. Oil ring; 24. Compression ring groove one; 25. Compression ring groove two; 26. Oil ring groove; 3. Recessed ring land; 31. Metering inlet port one; 32. Metering outlet port one; 33. Metering inlet port two; 34. Metering outlet port two; 36. Inlet port two; 41. Upper scraper of oil ring; 42. Lower scraper of oil ring; 43. Oil ring cavity; 44. Oil return hole; 51. Oil reservoir one; 52. Oil reservoir two; 61. Double-step joint one; 62. Double-step joint two; 63. Concave arc hole; 7. Top land; 71. Notched interface end; 72. Protruding tongue joint end; 73. Flat end; 81. Valve inlet surface; 82. Valve exhaust surface; 92. Lower outer tangent structure. Detailed Implementation

[0046] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0047] Reference Figures 1-12 Example 1: A piston second ring groove sealing structure includes a second ring groove 25 and a second ring 22 disposed at the head of piston 1. The second ring 22 has an elastic opening and is sleeved on the second ring groove 25. The second ring groove 25 has a metering air inlet 23 or an air inlet 26 on its upper side and a metering air outlet 24 on its lower side. The metering air inlet 23 or the air inlet 26 and the metering air outlet 24 communicate with the bottom of the second ring groove 25.

[0048] When the second air ring 22 is opened in the cylinder, it is still a fully sealed ring. It is a single-layer double-step overlap with a lower outer tangent structure and a fully sealed ring, or a single-layer single-step overlap with a lower outer tangent structure and a fully sealed ring. The second air ring 22 is provided with a lower outer tangent structure 92, which forms an oil distribution chamber.

[0049] The second metering air inlet 33 and the second metering air outlet 34 are further configured to correspond to the openings of the second air ring groove 25 and the second air ring 22.

[0050] When the second air ring 22 is a single-layer double-step overlap with a lower outer tangent structure full-sealing ring, since there are no air holes on the upper and lower sides of the overlap when the ring body is opened in the cylinder, the upper and lower sides of the second air ring groove 25 must be respectively provided with a metered air inlet hole 233 and a metered air outlet hole 24.

[0051] When the second air ring 22 is a single-layer single-step overlap with a lower external tangent structure fully sealed ring, since the air inlet 26 is formed on the upper side of the overlap when the ring body is opened in the cylinder, the upper side of the second air ring groove 25 does not need to be provided with a quantitative air inlet hole 233, while the lower side must be provided with a certain amount of air outlet hole 24.

[0052] It also includes a ring bank 2 above the second gas ring groove 25. The ring bank 2 is provided with an oil storage structure, that is, according to the axial thickness of the ring bank 2, several rows of oil storage holes are arranged around the ring bank 2. Taking the arrangement of two rows of oil storage holes as an example, a row of oil storage holes 51 is arranged at the same radial spacing in the middle of the outer circumference of the ring bank 2, and a row of oil storage holes 52 is arranged at the same radial spacing in the lower part of the ring bank 2 near the second gas ring groove 25. The first oil storage holes 51 and the second oil storage holes 52 are arranged in an alternating position.

[0053] The oil storage hole 51 in the middle of the ring 2 is circular, while the oil storage hole 52 near the ring groove 25 is arc-shaped. The depth of the oil storage hole 51 does not exceed the depth of the ring groove 24, while the depth of the oil storage hole 52 is 30% to 50% of the depth of the ring groove 25, and the oil storage hole 52 is axially connected to the ring groove 25. The opening spacing of the oil storage structure is adjusted according to different engine parameters. The circular shape of the oil storage hole 51 and the arc shape of the oil storage hole 52 facilitate milling, but other shapes, such as oil grooves, can also be used.

[0054] When the second gas ring 22 is a single-layer double-step joint with a lower outer tangent structure and a fully sealed ring, the two open ends of the second gas ring 22 are double-step joint 61 and double-step joint 62, respectively. The double-step joint 61 and double-step joint 62 are complementary structures, with their maximum openings meeting at the ends of the joints. A concave arc hole 63 is provided at the right-angle turn of the upper step of the double-step joint 61. Through the cooperation of the double-step joint 61 and the double-step joint 62, when the second gas ring 22 is tightly fitted to the cylinder wall and the lower side of the second gas ring groove 25 under the pressure of the combustion gas, a completely sealed structure is formed, thereby preventing the combustion gas from leaking downwards.

[0055] When the second gas ring 22 is a single-layer, single-step overlap with a lower external tangent structure, both ends of the elastic opening are flat ends 73 near the front side. The notched interface end 71 and the convex tongue overlap end 72 are both located on the bottom surface of the elastic opening at both ends. The gap between the two flat ends 73 forms the second air inlet 36. A short tongue end is provided inside the notched interface end 71 near the back side. The notched interface end 71, the convex tongue overlap end 72, and the short tongue end cooperate to form a semi-enclosed plug-in sealing structure. A concave arc hole 63 is provided at the right-angle turn where the notched interface end 71 connects with the short tongue end. Through the cooperation of the notched interface end 71, the convex tongue overlap end 72, and the short tongue end, when the second gas ring 22 is tightly attached to the cylinder wall and the lower side of the second gas ring groove 25 under the pressure of the combustion gas, a completely sealed structure is formed, thereby preventing the combustion gas from leaking downward.

[0056] The double-step joint 61 has a concave arc hole 63 at the right-angle turn, and the concave interface end 71 has a concave arc hole 63 at the right-angle turn where it connects with the short tongue end. The concave arc hole 63 is used to facilitate the milling cutter to process the inner right-angle part of the interface end. At the same time, when the piston 1 enters the power stroke, the arc-shaped concave arc hole 63 can act to buffer and distribute the engine oil and to steer and turbulent the combustion gas, as well as to buffer and reduce pressure.

[0057] The upper part of the piston 1 is the head of the piston 1, and the lower part of the piston 1 is the skirt of the piston 1. The piston 1 is installed in the cylinder. The combustion chamber is above the head of the piston 1, and the crankcase is below the skirt of the piston 1. The first ring groove 24 is provided above the second ring groove 25, and the oil ring groove 26 is provided below it. The first ring groove 24 is fitted with a fully sealed first ring 21, and the oil ring groove 26 is fitted with an oil ring 23. The top of the first ring groove 24 is a top lander 7, the space between the first ring groove 24 and the second ring groove 25 is a ring lander 2, and the space between the second ring groove 25 and the oil ring groove 26 is a recessed ring lander 3.

[0058] The oil ring groove 26 and the oil ring 23 are existing structures, and the oil ring 23 is a combined oil ring or an integral oil ring.

[0059] If the oil ring 23 of the oil ring groove 26 is selected to use a combined oil ring or an integrated oil ring, both of which are existing mature technologies, and no single limitation is made here.

[0060] If the oil ring 23 uses an existing combined oil ring, it includes an upper scraper 41, an inner liner, and a lower scraper 42. The upper and lower scrapers clamp the inner liner in the middle to form an oil ring cavity 43.

[0061] If the oil ring 23 is an integral oil ring, it consists of an outer frame of the oil ring and a support spring. The internal space of the outer frame of the oil ring and the support spring together form the oil ring cavity 43.

[0062] The combustion chamber is topped with a valve intake surface 81 and a valve exhaust surface 82. The position of the piston 1's top circular surface perpendicular to the center of the valve intake surface 81 is designated as 6 o'clock, and the position of the piston 1's top circular surface perpendicular to the center of the valve exhaust surface 82 is designated as 0 o'clock.

[0063] A metering air inlet 31 is provided at the 9 o'clock, 0 o'clock, or 3 o'clock position on the upper side of the air ring groove 24, and a metering air outlet 32 ​​is provided at the 0 o'clock or 6 o'clock position on the lower side of the air ring groove 24. The metering air inlet 31 and the metering air outlet 32 ​​are positioned correspondingly to form a U-shaped path in which the fuel gas drives the oil downward and the air and oil are drawn upward to circulate and renew. The metering air inlet 31 and the metering air outlet 32 ​​are positioned offset to form an extended arc-shaped path in which the fuel gas drives the oil downward and the air and oil are drawn upward to circulate and renew.

[0064] The second quantitative air inlet 33 or the second air inlet 36 and the second quantitative air outlet 34 must be set at the 0 o'clock or 6 o'clock position on the upper and lower sides of the second air ring groove 25 respectively. The second quantitative air inlet 33 or the second air inlet 36, the second air ring 22 and the second quantitative air outlet 34 form a new U-shaped path for the gas to drive the oil downward and the air and oil to be attracted upward to circulate and renew.

[0065] The piston second ring groove sealing structure and its fuel gas and oil circulation method include the following:

[0066] S1. When piston 1 enters the power and exhaust strokes, a large amount of combustion gas is blocked by the first gas ring, and a small amount of combustion gas descends to the ring land 2. The combustion gas reaching the ring land 2 causes the front of the second gas ring 22 to be pressurized. Part of the combustion gas enters the back of the ring from the upper side gap, and together with another part of the combustion gas, it is introduced into the back of the second gas ring 22 from the metered air inlet 23 or air inlet 26 at the 6 o'clock or 0 o'clock position to jointly establish side pressure, and is discharged from the metered air outlet 24 at the corresponding 6 o'clock or 0 o'clock position into the recessed ring land 3.

[0067] Even if a portion of the gas entering the ring bank 2 is guided to the recessed ring bank 3 from the new U-shaped path 2 formed by the metered air inlet 23 or air inlet 26 of the gas ring groove 25, the back of the gas ring 22 and the metered air outlet 24.

[0068] The combustion gas reaching the recessed ring land 3 then descends along the existing path, entering the oil ring cavity 43 from the scraper port 41 on the oil ring 23 or the integrated oil ring port, and then flowing back to the crankcase through the oil return hole 44. At the same time, the second combustion ring 22 coats the cylinder wall working surface with the oil buffered by the ring land 2 and the recessed ring land 3.

[0069] The process of the gas flowing downwards into the crankcase is simultaneously a process of purging and driving the engine oil downwards back into the crankcase.

[0070] S2. When piston 1 enters the intake stroke and moves downward, the oil in the crankcase is guided in the opposite direction of the downward path in step S1 to realize the renewal and circulation of oil in the head of piston 1.

[0071] When piston 1 enters the intake stroke and moves downward, the oil splashed and sprayed from the bottom of the crankcase is first drawn into the oil ring cavity 43 through the existing path from the oil return hole 44, and then guided into the recessed ring land 3 from the scraper 41 port or the integrated oil ring port on the combined oil ring. Then, it is guided to the ring land 2 through a new U-shaped path formed by the metered outlet hole 2 34, the back of the gas ring 22, and the metered inlet hole 2 33 or the inlet port 2 36.

[0072] The bottom surface is provided with a gas ring 22 with a lower outer tangent structure 92. When the piston 1 moves upward, the oil that is guided to the recessed ring land 3 and the ring land 2 is evenly coated on the working surface of the cylinder wall.

[0073] The size of the second quantitative air inlet 33 and the second quantitative air outlet 34 can be customized according to the requirements of different vehicle engines, so as to realize the customizable control of the amount of gas entering from the ring 2 into the recessed ring 3. The amount of gas leakage is not affected by the wear of the second air ring 22, and a fixed gas flow can be maintained stably for a long time.

[0074] Example 2 is a further implementation based on the structure of Example 1.

[0075] The method and requirements for inserting the second gas ring 22 into the second gas ring groove 25 are as follows:

[0076] (1) When the gas ring 22 is a single-layer double-step overlap with a lower outward tangential structure fully sealed ring, the overlap is as follows: Figure 5 , Figure 6 As shown, a metered air inlet 23 needs to be provided on the upper side of the 0 or 6 o'clock position of the air ring groove 25; and a metered air outlet 24 needs to be provided on the lower side of the corresponding 0 or 6 o'clock position.

[0077] ① When the metered air outlet 32 ​​of the air ring groove 24 is set at the 0 o'clock position, the metered air inlet 33 and the metered air outlet 34 must be set at the 6 o'clock position on the upper and lower sides of the air ring groove 25, and the opening of the air ring 22 can be aligned with the 3 o'clock or 9 o'clock position.

[0078] ②When the quantitative air outlet 32 ​​of the air ring groove 24 is set at the 6 o'clock position, the quantitative air inlet 33 and the quantitative air outlet 34 must be set at the 0 o'clock positions on the upper and lower sides of the air ring groove 25, and the opening of the air ring 22 can be aligned with the 3 o'clock or 9 o'clock position.

[0079] (2) When the gas ring 22 is a single-layer, single-step overlap with a lower external tangential structure fully sealed ring, the overlap is as follows: Figure 8 , Figure 9As shown, the second air inlet 36 must be located at the 0 or 6 o'clock position on the upper side of the second air ring groove 25, while the second metering air outlet 34 must be located at the 0 or 6 o'clock position on the lower side.

[0080] ①When the metering outlet 32 ​​of the air ring groove 24 is set at the 0 o'clock position, the air inlet 36 and the metering outlet 34 must be set at the 6 o'clock position on the upper and lower sides of the air ring groove 25, and the opening of the air ring 22 must be aligned with the 6 o'clock position.

[0081] ② When the metering outlet 32 ​​of the air ring groove 24 is set at the 6 o'clock position, the air inlet 36 and the metering outlet 34 must be set at the 0 o'clock position on the upper and lower sides of the air ring groove 25, and the opening of the air ring 22 must be aligned with the 0 o'clock position.

[0082] When selecting an existing combined oil ring or an integral oil ring for oil ring 23, the method and requirements for inserting it into the oil ring groove 26 are as follows:

[0083] The combined oil ring or the integrated oil ring mentioned above are both existing mature technologies, and their installation methods are the same as existing methods.

[0084] If the oil ring 23 uses the existing combined oil ring, the port of the upper scraper 41 should be aligned with the left and right sides of the 0 o'clock or 6 o'clock position opposite to the direction of the second quantitative air outlet 34; the port of the lower scraper 42 should be aligned with the left and right sides of the 6 o'clock or 0 o'clock position opposite to the direction of the port of the upper scraper 41.

[0085] If the oil ring 23 uses the existing integrated oil ring, the port of the oil ring 23 should be aligned with the left and right sides of the 0 point or 6 o'clock position opposite to the quantitative air outlet 24.

[0086] Detailed working principle of piston 1, compression ring 22, and compression ring groove 25 in combination:

[0087] The structure of the second gas ring 22 further ensures that the ring retains sufficient expansion elastic space when blocking gas, while keeping the expansion and contraction ports in a continuous sealing state. This achieves a high degree of sealing of the gas reaching the ring land 2 by the piston 1. In conjunction with the U-path 2 formed by the second gas ring groove 25, it achieves flow restriction and guidance control of the air and oil flowing upward from the recessed ring land 3 to the ring land 2, and the gas and oil flowing downward from the ring land 2 to the recessed ring land 3.

[0088] When piston 1 enters the intake stroke, the oil splashed or sprayed from the crankcase is drawn upward by the negative pressure of the combustion chamber. The oil quickly and sufficiently rises to the oil ring cavity 43, the recessed ring land 3, the second compression ring groove 25, the ring land 2, and the first compression ring groove 24, promptly satisfying the lubrication supply to the oil ring 23, the second compression ring 22, and the first compression ring 21. The flow restriction and guidance of the sealing structure of the second compression ring groove 25 and the second compression ring 22 prevent excessive oil reaching the recessed ring land 3 from rising to the ring land 2; the flow restriction and guidance of the sealing structure of the first compression ring groove 24 and the first compression ring 21 prevent excessive oil reaching the gap between the back of the first compression ring 21 and the bottom of the first compression ring groove 24, and prevent excessive oil from rising into the combustion chamber.

[0089] The structure of the second compression ring groove 25 and the second compression ring 22 connects to the sealing structure of the first compression ring groove 24 and the first compression ring 21 above, and to the oil ring groove 26 and the oil ring 23 below. The sealing structure of the first compression ring groove 24 and the first compression ring 21 has the functions of limiting and guiding flow, while strengthening the buffering and buffering effect of the oil ring cavity 43, the recessed ring land 3, the second compression ring groove 25, the ring land 2, and the first compression ring groove 24 on the oil. The structure of the second compression ring groove 25 and the second compression ring 22 continues and supports the functions of limiting, guiding flow, buffering, and buffering of the sealing structure of the first compression ring groove 24 and the first compression ring 21, ensuring the amount of oil buffered in the piston head of piston 1. After each combustion gas purging, some oil is still retained in the bottom gap of the first compression ring groove 24, the ring land 2, the bottom gap of the second compression ring groove 25, the recessed ring land 3, and the oil ring cavity 43, which meets the lubrication needs of the piston head of piston 1.

[0090] When piston 1 enters the power and exhaust strokes, the gas flows down through the sealing structure of the gas ring groove 24 and gas ring 21. About 8%-10% of the gas passes through the gas ring groove 24 and enters the ring land 2. Then, the gas ring 22 continues to bear the pressure of the gas and seals again, blocking the gas from flowing down and keeping less than 10% of the gas above the gas ring groove 25.

[0091] When the second ring 22 is a single-layer double-step overlap with a lower outer tangent structure fully sealed ring, part of the combustion gas entering the ring land 2 leaks downward from the gap between the outer surface of the ring body and the cylinder wall and the ring body overlap gap through the radial wave-like bouncing during the up-and-down movement of the body. The other part enters the bottom of the second ring groove 25 through the upper side gap and the metered air inlet 233 at the 6 o'clock or 0 o'clock position, and is introduced into the recessed ring land 3 from the metered air outlet 24 at the corresponding 6 o'clock or 0 o'clock position.

[0092] When the second ring 22 is a single-layer, single-step overlap with a lower outer tangent structure and a fully sealed ring, part of the combustion gas entering the ring land 2 leaks downward from the gap between the outer surface of the ring body and the cylinder wall and the overlap gap of the ring body through the radial wave-like bouncing when the ring body moves up and down. The other part enters the bottom of the second ring groove 25 through the upper side gap and the air inlet 26 at the 6 o'clock or 0 o'clock position, and is introduced into the recessed ring land 3 from the corresponding metered air outlet 24 at the 6 o'clock or 0 o'clock position.

[0093] The gas arriving at the concave ring bank 3 follows the existing path, traveling along the concave ring bank 3 to the two sides along the arc-shaped gas passage, where it meets at the corresponding 0 or 6 o'clock position on the circular surface. It is then guided to the oil ring cavity 43 through the port of the combined oil ring scraper 41 or the upper side of the integrated oil ring port, and finally discharged into the crankcase through the return oil hole 44.

[0094] The dimensions of the second quantitative air inlet 33 and the second quantitative air outlet 34 can be customized according to the needs of different models of pistons 1, thereby achieving flow restriction and guidance control of the gas that passes through the second gas ring 22 and enters the recessed ring land 3.

[0095] By setting the corresponding positions of the quantitative air inlet hole 2 33 or the air inlet 2 36 and the quantitative air outlet hole 2 34, a new U-shaped path 2 is formed between the quantitative air inlet hole 2 33 or the air inlet 2 36 and the quantitative air outlet hole 2 34, so that the gas passes through the gas ring 2 22 and the gas ring groove 25, thereby achieving the effects of limiting, guiding, cooling and reducing the pressure of the gas that reaches the ring bank 2 and enters the recessed ring bank 3.

[0096] The gas enters the ring bank 2 through a new U-shaped path or arc-shaped extended path composed of a metered inlet port 31, a ring back, and a metered outlet port 32. This path restricts, guides, reduces pressure, and lowers the temperature of the gas. The gas has become more gentle, avoiding the fierce sweeping of gas when the gas ring 21 is a traditional flat-mouth gas ring.

[0097] The oil storage structure of the ring bank 2 increases the space of the ring bank 2, increases the oil buffer capacity, improves the collection speed of upward oil, and slows down the upward movement of oil from the ring bank 2 to the cylinder wall groove 24. At the same time, it buffers, turbulents, depressurizes, and cools the downward combustion gas, slows down the downward speed of the combustion gas, and ensures that after the downward purging of the combustion gas, the oil retained in the ring bank 2 meets the stable supply to the contact surface between the outer circular surface 16 of the cylinder wall and the cylinder wall, thereby improving the oil distribution quantity, oil distribution speed and uniformity of the cylinder wall and the cylinder wall groove 22.

[0098] The combustion gas, after being blocked by the fully sealed structure of the second piston ring 22, descends to the recessed ring land 3, where its flow becomes smoother. The lower outer tangent structure 92 on the bottom surface of the second piston ring 22 expands the space of the recessed ring land 3, which is beneficial for the expansion and cooling of the descending combustion gas, further reducing the gas flow rate. At the same time, it helps to buffer more engine oil, increasing the adhesion area and adhesion speed of the engine oil to the second piston ring 22. The thinning of its outer circular surface reduces friction with the cylinder wall. In addition, the torsional effect of the thinned ring helps to distribute the engine oil evenly and promptly to the working surface of the cylinder wall when the piston 1 moves upward, and can more effectively scrape off excess engine oil from the cylinder wall when the piston 1 moves downward, thus ensuring and optimizing the oil distribution effect of the second piston ring 22.

[0099] The fully sealed structure of the second gas ring 22 reduces the pressure, flow rate, and temperature of the combustion gas and engine oil inside and at the bottom of the second gas ring groove 25, thereby improving the efficiency and effect of oil distribution. It completely avoids the problem of excessive leakage during initial installation of existing flat-mouth gas rings, which leads to a continuous expansion of the port as the outer circumference of the ring wears down, resulting in a synchronous decline in sealing effect.

[0100] The gas flow gently blows the recessed ring land 3, which on the one hand blows the buffered oil into the oil ring cavity 43 and then returns it to the crankcase through the oil return hole 44; on the other hand, the gas ring 22 and the oil ring 23 evenly spread the oil buffered in the recessed ring land 3 and the oil ring cavity 43 onto the cylinder wall working surface to ensure the smooth operation of the piston 1.

[0101] The combustion gas entering the concave ring lander 3 is then blocked by the oil ring 23. Finally, only a trace amount of combustion gas, about 0.01%, can reach the crankcase through the oil ring groove 26.

[0102] The combustion gases in the combustion chamber travel downwards, first passing through the sealing structures of the first ring groove 24 and the first ring 21 to reach the ring land 2. Then, they pass through the sealing structures of the second ring groove 25 and the second ring 22 to enter the recessed ring land 3, and finally reach the oil ring cavity 43. Through the oil return hole 44, they are discharged into the crankcase, completing a process of driving the engine oil from the gap between the back of the first ring 21 and the bottom of the first ring groove 24 → ring land 2 → recessed ring land 3 → oil ring cavity 43 → oil return hole 44 → crankcase backflow.

[0103] The oil is drawn upwards and buffered, while the combustion gas is restricted and guided, driving the oil downwards for a return circulation and renewal.

[0104] During the intake stroke, the engine oil is drawn upwards once, and then blown downwards three times by air, air-fuel mixture, or exhaust during the compression stroke, power stroke, and exhaust stroke. The engine oil continuously rises and falls with the up-and-down movement of piston 1, realizing the process of oil circulation and buffering renewal at the head of piston 1.

[0105] The oil that reaches the head of piston 1 during the upward stroke of the intake stroke, and the oil that remains at the head of piston 1 after the downward stroke is purged by the combustion gases, are spread onto the working surface of the cylinder wall by the oil ring 23, the second compression ring 22, and the first compression ring 21 as piston 1 moves up and down. This ensures good lubrication between the outer surface of the oil ring 23, the second compression ring 22, and the first compression ring 21 and the working surface of the cylinder wall.

[0106] The combination of the structure of the first gas ring 21 and the first gas ring groove 24 with the structure of the second gas ring 22 and the second gas ring groove 25, as well as the structure of the oil ring groove 26 and the oil ring 23, allows the piston 1 to be used as a whole, achieving a high degree of sealing of the combustion gas. The amount of combustion gas leaking downward into the crankcase is not affected by the wear and outward elasticity of the first gas ring 21, the second gas ring 22, and the oil ring 23, and can maintain a fixed flow of combustion gas and engine oil for a long time, so as to maintain a constant high cylinder pressure in the combustion chamber for a long time.

[0107] Under high cylinder pressure, a very small amount of oil is introduced into the combustion chamber and participates in combustion with the fuel in a manner closest to complete combustion. This completely avoids the formation of carbon black and gum, thus completely preventing the adhesion of carbon deposits to the piston head and crankcase. This eliminates the risk of cylinder scoring and crankshaft seizure caused by carbon deposits. The controlled and reduced leakage of combustion gases prevents the oil buffered in the labyrinthine channel of the piston head from being excessively sheared due to high-temperature vaporization, significantly extending the oil life, ensuring the lubrication performance of the oil, and significantly increasing the service life of the piston, compression ring 21, compression ring 22, and oil ring 23.

[0108] This invention is used in piston engines with two compression ring grooves and one oil ring groove, and can also be used in piston engines with three compression ring grooves and one oil ring groove. When used in an engine with three compression ring grooves, an existing ordinary flat-mouth ring is placed in the first compression ring groove, a fully sealed compression ring 21 of this invention is placed in the second compression ring groove, a compression ring 22 of this invention is placed in the third compression ring groove, and an oil ring 23 is placed in the fourth oil ring groove.

[0109] This invention utilizes a fully sealed structure in the second gas ring 22, along with an externally tangent structure 92 on the bottom surface of the second gas ring 22. Combined with an oil storage structure in the ring lander 2 and flow-limiting and guiding features such as a metering leakage hole, it effectively controls the leakage of combustion gases and optimizes the oil distribution effect. This design improves lubrication performance, prevents carbon buildup and abnormal wear, and enhances engine efficiency, lifespan, and performance.

[0110] The aforementioned sealing structure of the air ring is applicable to piston air compressors, piston refrigeration machines, piston-type lifting equipment, i.e., a piston air compressor or air compressor piston or piston refrigeration machine or refrigeration machine piston or piston-type lifting equipment or other equipment piston.

[0111] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0112] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A piston second ring groove sealing structure, comprising a second ring groove (25) and a second ring (22) disposed at the head of the piston (1), characterized in that, The second air ring (22) is provided with an elastic opening and is fitted onto the second air ring groove (25). The upper side of the second air ring groove (25) is provided with a metering air inlet hole (33) or an air inlet (36), and the lower side of the second air ring groove (25) is provided with a metering air outlet hole (34). The metering air inlet hole (33) or the air inlet (36) and the metering air outlet hole (34) are connected to the bottom of the second air ring groove (25). When the second gas ring (22) is opened in the cylinder, it is still a fully sealed ring. It is a single-layer double-step overlap with a lower outer tangent structure fully sealed ring, or a single-layer single-step overlap with a lower outer tangent structure fully sealed ring; the second gas ring (22) is provided with a lower outer tangent structure (92).

2. The piston second ring groove sealing structure according to claim 1, characterized in that, It also includes a ring bank (2) above the second gas ring groove (25). A row of oil storage holes (51) is arranged at the same radial spacing in the middle of the outer circumference of the ring bank (2). A row of oil storage holes (52) is arranged at the same radial spacing at the lower part of the ring bank (2) near the second gas ring groove (25). Each of the first oil storage holes (51) and each of the second oil storage holes (52) are arranged in an alternating position.

3. The piston second ring groove sealing structure according to claim 2, characterized in that, The oil storage hole 1 (51) in the middle of the ring bank (2) is circular, and the oil storage hole 2 (52) near the gas ring groove 2 (25) is arc-shaped. The depth of the oil storage hole 1 (51) does not exceed the depth of the gas ring groove 1 (24), while the depth of the oil storage hole 2 (52) is 30% to 50% of the depth of the gas ring groove 2 (25), and the oil storage hole 2 (52) is axially connected to the gas ring groove 2 (25).

4. The piston second ring groove sealing structure according to claim 1, characterized in that, When the second air ring (22) is a single-layer double-step joint with a lower external tangent structure full sealing ring, the two open ends of the second air ring (22) are double-step joint one (61) and double-step joint two (62), respectively. The double-step joint one (61) and double-step joint two (62) are complementary structures. The maximum openings of the double-step joint one (61) and double-step joint two (62) are joined at the end of the joint. A concave arc hole (63) is provided at the right angle turn of the upper step of the double-step joint one (61).

5. The piston second ring groove sealing structure according to claim 1, characterized in that, When the second air ring (22) is a single-layer single-step overlap with a lower external tangent structure full sealing ring, the two ends of the elastic opening are flat ends (73) near the front side. The concave interface end (71) and the convex tongue overlap end (72) are located on the bottom surface of the two ends of the elastic opening. The gap between the two flat ends (73) forms the second air inlet (36). The concave interface end (71) is provided with a short tongue end near the back side. The concave interface end (71), the convex tongue overlap end (72) and the short tongue end cooperate to form a semi-enclosed plug-in sealing structure. The concave interface end (71) is provided with an inner concave arc hole (63) at the right angle turn where it connects with the short tongue end.

6. The piston second ring groove sealing structure according to any one of claims 1 to 5, characterized in that, The second gas ring groove (25) is provided with a first gas ring groove (24) above it and an oil ring groove (26) below it. The first gas ring groove (24) is fitted with a fully sealed first gas ring (21), and the oil ring groove (26) is fitted with an oil ring (23). The top of the first gas ring groove (24) is a top bank (7), the space between the first gas ring groove (24) and the second gas ring groove (25) is a ring bank (2), and the space between the second gas ring groove (25) and the oil ring groove (26) is a recessed ring bank (3).

7. The piston second ring groove sealing structure according to claim 6, characterized in that, The combustion chamber is provided with a valve intake surface (81) and a valve exhaust surface (82) at the top. The position of the top circular surface of the piston (1) perpendicular to the middle of the valve intake surface (81) is set at 6 o'clock, and the position of the top circular surface of the piston (1) perpendicular to the middle of the valve exhaust surface (82) is set at 0 o'clock.

8. The piston second ring groove sealing structure according to claim 7, characterized in that, A metered air inlet hole (31) is provided at the 9 o'clock, 0 o'clock, or 3 o'clock position on the upper side of the air ring groove (24), and a metered air outlet hole (32) is provided at the 0 o'clock or 6 o'clock position on the lower side of the air ring groove (24). The metered air inlet hole (31) and the metered air outlet hole (32) are set in corresponding positions to form a U-shaped path for the gas and oil to pass through vertically. The metered air inlet hole (31) and the metered air outlet hole (32) are set in staggered positions to form an arc-shaped extended path for the gas and oil to pass through vertically.

9. The piston second ring groove sealing structure according to claim 8, characterized in that, The quantitative air inlet hole 2 (33) or air inlet 2 (36) and the quantitative air outlet hole 2 (34) must be set at the 0 o'clock or 6 o'clock position on the upper and lower sides of the air ring groove 2 (25). The quantitative air inlet hole 2 (33) or air inlet 2 (36), the air ring 2 (22) and the quantitative air outlet hole 2 (34) form a U-shaped path 2 where the gas drives the oil downward and the air and oil are attracted upward to circulate and renew.

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