Piston ring for large-cylinder-diameter ship internal combustion engine

Abstract

The invention relates to the technical field of piston rings, in particular to a piston ring for a large-cylinder-diameter ship internal combustion engine. In an internal combustion engine, a first ring is generally provided with an overlapping lapping opening, but for a large-cylinder-diameter internal combustion engine, high-temperature fuel gas has a longer circumferential flowing distance of a gap between a piston and a cylinder wall, so that the position far away from the overlapping lapping opening is easily blocked in flowing, and local high temperature and non-uniform temperature distribution of a firepower bank in the circumferential direction are caused. Therefore, the vertical gap is additionally arranged on the opposite side of the circumference of the first ring overlapping lapping opening, circumferential blocking of high-temperature flue gas is reduced, and it is ensured that the temperature distribution of a firepower bank in the circumferential direction is more uniform. The leakage rate of the first ring increased by additionally arranging the vertical gap is controlled by adjusting the lap gap of the second ring and the third ring, and it is ensured that the overall gas leakage rate of the piston ring set is within the preset range. The vertical gap is increased, the problem that the local pressure and temperature are increased due to the fact that gas circumferential flow is blocked is solved, meanwhile, the second ring and the third ring are combined to control the overall gas leakage amount, and the overall performance of the piston ring set is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of piston rings, and particularly to a piston ring for a large-bore marine internal combustion engine. Background Art

[0002] With the continuous improvement of new emission requirements, marine low-speed internal combustion engines are developing in diversified directions such as large bore, intelligent control, and clean energy. Adopting a high-pressure ratio, high-efficiency supercharging system and high-pressure fuel injection system is an effective way to achieve this goal, and these technical means put forward new and higher requirements for friction pair components, especially for piston ring design, arrangement and durability.

[0003] As one of the key friction pair components of the engine, the piston ring plays an important role in the economy and reliability of the engine. The piston ring has a complex structure and high technical requirements. According to the different functions of the piston ring, the piston ring is divided into a compression ring and an oil scraping ring. One function of the compression ring is to seal between the piston and the cylinder during high-speed reciprocating motion to prevent the high-temperature gas in the cylinder from leaking into the crankcase; another function of the compression ring is heat transfer. When the internal combustion engine burns and explodes, the high-temperature gas enters the piston ring group, causing the working temperature at the opening of the piston ring to rise. Persistent operation is likely to cause wear, resulting in cylinder gas leakage and oil leakage. Especially the first piston ring is directly affected by the high-temperature and high-pressure gas. Due to the leakage of gas through the lap joint, cylinder wall and ring groove gap, the other rings will also be affected by the entering gas to a certain extent. At the same time, for large-bore internal combustion engines, due to the increase in the circumferential length, the oil film and gap are unevenly distributed, and the flow of high-temperature flue gas in the gap between the piston and the cylinder wall is blocked, forming a local accumulation area of gas, resulting in local high-temperature deformation, which is likely to cause cylinder scoring and damage the engine. Summary of the Invention

[0004] In view of the above-mentioned technical problems, a piston ring for a large-bore marine internal combustion engine is provided. The present invention designs a piston ring for a large-bore marine internal combustion engine. Compared with a small-bore internal combustion engine, in a large-bore internal combustion engine, the high-temperature gas has a longer circumferential flow distance in the gap between the piston and the cylinder wall. Due to the uneven distribution of the oil film, the flow of high-temperature flue gas in this gap is easily blocked, resulting in local accumulation of high-temperature gas, forming problems such as local high temperature and uneven circumferential temperature distribution along the fire shore, causing uneven deformation and cylinder scoring of the internal combustion engine, and damaging the engine. The present invention proposes to increase a vertical gap at the circumferentially corresponding position of the overlapping lap joint of the first ring in the large bore to relieve the problems of local pressure and temperature increase caused by the blocked circumferential flow of gas. The newly added vertical gap in the first ring will cause an increase in the gas leakage amount of the first ring, transfer part of the load to the second ring, and at the same time, control the overall gas leakage amount by combining the size of the first lap joint gap on the second ring to ensure the overall performance of the piston ring group.

[0005] The technical means adopted by the present invention are as follows:

[0006] A piston ring for a large-bore marine internal combustion engine, which is applied in a large-bore internal combustion engine. The piston ring is composed of multiple rings and at least includes: a first ring and a second ring, where:

[0007] A vertical gap is provided on the first ring to ensure uniform circumferential temperature distribution along the fire shore. The second ring is arranged below the first ring; the second ring is used to control the gas leakage amount. A first lap joint is provided on the second ring, and by controlling the gap size of the first lap joint, the overall gas leakage amount of the piston ring is ensured to be within a preset range.

[0008] Furthermore, an overlapping lap joint is also provided at one end of the first ring away from the vertical gap.

[0009] Furthermore, the gap size of the vertical gap is determined according to the gas leakage amount and the local pressure.

[0010] Furthermore, the gap size of the first lap joint is determined according to the gas leakage amount and the local pressure.

[0011] Furthermore, the piston ring is made of a wear-resistant and high-temperature-resistant material.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] The piston ring for a large-bore marine internal combustion engine provided by the present invention reduces the requirements for materials and process difficulty in the manufacturing of the entire ring of the large-bore piston ring by adding a vertical gap at the farthest distance from the overlapping lap joint on the first ring.

[0014] The piston ring for a large-bore marine internal combustion engine provided by the present invention solves the problem that the high-temperature flue gas flow is blocked inside the fire shore, resulting in local high temperature and excessive local thermal deformation, causing cylinder scoring and engine damage. At the same time, the uniformity of the circumferential load is increased.

[0015] The piston ring for a large-bore marine internal combustion engine provided by the present invention ensures that the overall air leakage amount does not increase by increasing the leakage amount of the first ring and reducing the leakage amount by reducing the lap joint gap of the second ring. At the same time, part of the load of the first ring is shared by the second ring, reducing the wear and failure risks.

[0016] Based on the above reasons, the present invention can be widely promoted in the fields of piston rings and the like. Description of the Drawings

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of a piston ring for a large-bore marine internal combustion engine in the present invention.

[0019] Figure 2 It is a schematic structural diagram of the first ring in the present invention.

[0020] Figure 3 It is a comparison of the fire shore wall surface temperatures with different lap designs in the embodiments of the present invention.

[0021] Figure 4 It is a comparison of the circumferential temperature distributions with different lap designs in the embodiments of the present invention.

[0022] Figure 5 It is a comparison of the leakage amounts of each piston ring with different lap designs in the embodiments of the present invention.

[0023] In the figure: 1. The first ring; 2. The second ring; 3. The third ring; 4. The vertical gap; 5. The overlapping lap; 6. The first lap; 7. The second lap. Detailed implementation manners

[0024] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The following will describe the present invention in detail with reference to the drawings and in combination with the embodiments.

[0025] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0027] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the specification. In all the examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not require further discussion in subsequent drawings.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus cannot be construed as limiting the protection scope of the present invention: the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0029] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation described in the figure for the device. For example, if the device in the attached drawing is inverted, the device described as "above or over other devices or structures" will then be positioned as "below or under other devices or structures". Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations are made for the spatial relative descriptions used here.

[0030] In addition, it should be noted that the use of terms such as "first", "second" etc. to limit components is only for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus cannot be construed as limiting the protection scope of the present invention.

[0031] As Figure 1 shown, the present invention provides a piston ring for use in a large-bore marine internal combustion engine, which is applied in a large-bore internal combustion engine. The piston ring consists of multiple rings and at least includes: a first ring 1 and a second ring 2, where:

[0032] As Figure 2 shown, a vertical gap 4 is provided on the first ring 1 to ensure uniform circumferential temperature distribution along the fire deck. The second ring 2 is used to control the gas leakage amount, and the second ring 2 is arranged below the first ring 1; a first butt joint 6 is provided on the second ring 2, and by controlling the size of the gap of the first butt joint 6, the overall gas leakage amount of the piston ring is ensured to be within a preset range.

[0033] During implementation, for the high-temperature flue gas in a large-bore marine internal combustion engine, the flow distance in the gap between the piston and the cylinder wall increases, and the flow is blocked, which easily forms a local gas accumulation area. By increasing the vertical gap 4, the problem of gas retention and accumulation increasing the local pressure and temperature is alleviated, thereby reducing the possibility of cylinder pulling and engine damage caused by local high-temperature deformation.

[0034] In addition, by increasing the vertical gap 4 on the first ring 1, that is, manufacturing the piston ring in two parts, the manufacturing process difficulty and material requirements are reduced on the premise of ensuring uniform material properties.

[0035] During specific implementation, as a preferred implementation manner of the present invention, an overlapping butt joint 5 is further provided at one end of the first ring 1 away from the vertical gap 4.

[0036] In implementation, for large-bore marine internal combustion engines having a greater circumferential length relative to small-bore internal combustion engines, and when there is only a single joint in the first ring 1, high-temperature gas has a longer circumferential flow distance in the gap between the piston and the cylinder wall. It is proposed to add a small vertical gap 4 at the circumferentially farthest distance of 5 from the overlapping joint of the first ring 1, so that the first ring 1 bears a more uniform load circumferentially.

[0037] In specific implementation, as a preferred implementation manner of the present invention, the size of the gap of the vertical gap 4 is determined according to the amount of gas leakage and the magnitude of the local pressure.

[0038] In specific implementation, as a preferred implementation manner of the present invention, the size of the gap of the first joint 6 is determined according to the amount of gas leakage and the magnitude of the local pressure.

[0039] In implementation, after adding the vertical gap 4 to the first ring 1, the leakage amount of the first ring 1 will increase. By reducing the size of the first joint 6 on the second ring 2, the overall leakage amount is not increased.

[0040] In specific implementation, as a preferred implementation manner of the present invention, the piston ring is made of a wear-resistant and high-temperature-resistant material. In implementation, the piston ring is selected to be made of a material with good elasticity, a small friction coefficient, wear resistance, and high temperature resistance.

[0041] Embodiment 1

[0042] As Figure 1 shown, the present invention provides a piston ring for use in large-bore marine internal combustion engines. When the first ring 1 and the second ring 2 cannot ensure that the overall gas leakage amount is within a safe range, it can be considered to add a third ring 3. A second joint 7 is provided on the third ring 3, and the position of the second joint is far from the first joint 6. The size of the second joint 7 can also be determined according to the amount of gas leakage and the magnitude of the local pressure.

[0043] Embodiment 2

[0044] As Figure 3 shown, the present invention conducted experiments on the fire shore cloud diagrams in three cases of not adding an overlapping joint, adding a smaller overlapping joint, and adding a larger overlapping joint. It can be clearly seen from the fire shore cloud diagrams of the piston rings in different cases that the local thermal deformation of the piston ring without adding an overlapping joint is more serious than that of the piston ring with an overlapping joint added, and the effect of the piston ring with a larger overlapping joint added is better than that of the piston ring with a smaller overlapping joint added.

[0045] As Figure 4As shown, the present invention conducts experiments on the circumferential temperature uniformity of the piston ring's firing land under three conditions: without adding a vertical gap, adding a small vertical gap, and adding a large vertical gap. It can be clearly seen from the circumferential temperature uniformity of the piston ring under different conditions that for the piston ring without a vertical gap, the local temperature is relatively high; for the piston ring with a small vertical gap, the local temperature is still relatively high, and the effect is not ideal. However, for the piston ring with a large vertical gap, the circumferential temperature tends to be uniform, which can achieve the effect of alleviating the accumulation of gas retention and increasing the local pressure and temperature, thereby reducing the possibility of cylinder scoring and engine damage caused by local high-temperature deformation.

[0046] As Figure 5 shown, the piston ring outlet flow rates set for the three rings in Embodiment 1 are tested. It can be seen from the test results in the figure that by setting multiple rings, the outlet flow rate of the piston ring can be stabilized within a safe range, reducing the risks of wear and failure.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A piston ring for use in a large-bore marine internal combustion engine, which is applied in a large-bore internal combustion engine, is characterized in that The piston ring is composed of multiple rings, and the piston ring at least includes: a first ring (1) and a second ring (2), wherein: A vertical gap (6) is provided on the first ring (1) to ensure uniform circumferential temperature distribution along the fire deck. The second ring (2) is arranged below the first ring (1); the second ring (2) is used to control the gas leakage amount, and a first lap joint (6) is provided on the second ring (2). By controlling the gap size of the first lap joint (6), the overall gas leakage amount of the piston ring is ensured to be within a preset range.

2. The piston ring for a large-bore marine internal combustion engine according to claim 1, characterized in that, An overlapping lap joint (5) is further provided at one end of the first ring (1) away from the vertical gap (6).

3. The piston ring for use in a large-bore marine internal combustion engine according to claim 1, characterized in that, The gap size of the vertical gap (6) is determined according to the gas leakage amount and the magnitude of the local pressure.

4. The piston ring for use in a large-bore marine internal combustion engine according to claim 1, characterized in that, The gap size of the first lap joint (6) is determined according to the gas leakage amount and the magnitude of the local pressure.

5. The piston ring for use in a large-bore marine internal combustion engine according to claim 1, characterized in that, The piston ring is made of a wear-resistant and high-temperature-resistant material.

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