Piston ring for an engine with circumferential positioning function and engine system

Abstract

This invention provides a piston ring for an engine with circumferential positioning function and an engine system. The piston ring includes: a first ring body, installed between the piston and the inner wall of the cylinder, the first ring body having a first notch in the circumferential direction, and two first protrusions extending in the axial direction formed on the upper and lower sides of the first ring body respectively; and two second ring bodies, respectively installed on the upper and lower sides of the first ring body, each second ring body having a second notch in the circumferential direction, the two first protrusions extending into the second notches of the two second ring bodies respectively to restrict the rotation of each second ring body relative to the first ring body and prevent the two second notches from aligning with the first notch in the axial direction, and lubricating oil flowing to the outside of the piston ring through the first notch and the two second notches.

Description

Technical Field

[0001] At least one embodiment of the present invention relates to the field of internal combustion engine component technology, and particularly to a piston ring for an engine and an engine system having a circumferential positioning function. Background Technology

[0002] Piston rings are a key component of internal combustion engines, consisting of elastic metal rings located within grooves in the piston. Firstly, they seal the combustion chamber to prevent gases from entering the crankcase through gaps in the piston walls. Secondly, since some energy generated during combustion can be transferred to the piston boundaries, they also transfer heat from the piston to the engine cooling system. Thirdly, piston rings control oil flow between the piston and cylinder wall, scraping away excess oil to limit its intrusion into the combustion chamber and reduce harmful gas emissions. Furthermore, piston rings also provide structural support.

[0003] Existing piston rings typically employ a monolithic design, which is widely used in engines due to its simple manufacturing process and convenient installation. However, monolithic piston rings are prone to uneven heating and thermal expansion on both the upper and lower surfaces, leading to ring deformation and ultimately seal failure.

[0004] To address the aforementioned issues, the prior art provides a composite piston ring with a two-ring stacked design. By stacking the two rings, the flexibility of the piston ring is enhanced, allowing it to fit more tightly against the inner wall of the cylinder.

[0005] However, when the cylinder is operating at high temperature and high pressure, relative movement will occur between the two rings, causing the notches formed on the two rings to coincide in the axial direction. This allows the lubricating oil in the piston rings to flow to the outside of the piston rings through the coinciding notches. Summary of the Invention

[0006] In view of this, the present invention provides a piston ring for an engine with circumferential positioning function to prevent lubricating oil inside the piston ring from flowing to the outside of the piston ring through the first notch, the second notch and the third notch.

[0007] According to an embodiment of the present invention, a piston ring for an engine with circumferential positioning function is provided, comprising: a first ring body, installed between a piston and the inner wall of a cylinder, the first ring body having a first notch in the circumferential direction, and two first protrusions extending in the axial direction formed on the upper and lower sides of the first ring body respectively; and two second ring bodies, respectively installed on the upper and lower sides of the first ring body, each second ring body having a second notch in the circumferential direction, the two first protrusions extending into the second notches of the two second ring bodies respectively, so as to restrict the rotation of each second ring body relative to the first ring body.

[0008] According to an embodiment of the present invention, the two first protrusions are symmetrically arranged about the radial extension line of the first ring body where the first notch is located.

[0009] According to an embodiment of the present invention, each of the second ring bodies has a second protrusion extending in the axial direction on the side facing the first ring body, and the two second protrusions extend into the first notch from the upper and lower sides of the first ring body respectively.

[0010] According to an embodiment of the present invention, the first ring body has arc-shaped protrusions extending in the circumferential direction on its upper and lower sides respectively. The cross-sectional area of ​​the arc-shaped protrusions is configured as a trapezoid that gradually decreases toward the first ring body. The two arc-shaped protrusions are symmetrically arranged about the radial extension line of the first ring body where the first notch is located. Each second ring body has a matching arc-shaped protrusion adapted to the arc-shaped protrusion on the semicircle opposite to the second notch, so as to restrict the two second ring bodies from moving in the axial direction relative to the first ring body.

[0011] According to an embodiment of the present invention, the two arc-shaped protrusions extend 180° from the position of the first notch in opposite circumferential directions, and the mating arc-shaped protrusion extends 180° from the position of the second protrusion in the circumferential direction and is opposite to the second notch. The mating arc-shaped protrusions of the two second rings respectively combine with the two arc-shaped protrusions located on both sides of the first ring, so that the first ring and the two second rings respectively form a complete circumferential surface in the circumferential direction.

[0012] According to an embodiment of the present invention, the annular outer wall surface of the first ring body is configured to bulge radially outward at the middle portion, and the annular outer wall surface of each second ring body is configured to be radially inward toward the first ring body, and the maximum outer diameter of the first ring body and the second ring body is the same, such that the stacked first ring body, the two second ring bodies and the inner wall of the cylinder form a cavity for storing lubricating oil.

[0013] According to an embodiment of the present invention, the width of the end of each of the arcuate protrusions that engages with the first ring body in the radial direction is 1 / 2 of the maximum width of the first ring body in the radial direction; the width of the end of the mating arcuate protrusion that engages with the first ring body in the axial direction in the radial direction is 1 / 2 of the maximum width of the second ring body in the radial direction.

[0014] According to an embodiment of the present invention, a groove extending in the circumferential direction is formed on the outer side of the second ring body located on the upper side away from the upper surface of the first ring body, so that when the second ring body located on the upper side moves inside the cylinder, under the action of the piston, the second ring body located on the upper side generates torque to adhere to the inner wall of the cylinder body, thereby increasing the contact force between the second ring body located on the upper side and the inner wall of the cylinder body.

[0015] According to an embodiment of the present invention, the coefficient of thermal expansion of the second ring located on the upper side, a2, is greater than the coefficient of thermal expansion of the first ring, a1, and the coefficient of thermal expansion of the second ring located on the lower side, a3.

[0016] According to an embodiment of the present invention, an engine system is provided, comprising: a cylinder block; a piston mounted inside the cylinder block; and a piston ring for an engine having a circumferential positioning function as described in the above embodiment, mounted between the piston and the cylinder block.

[0017] According to the above embodiments of the present invention, a piston ring for an engine with circumferential positioning function has two first protrusions extending in the axial direction formed on the upper and lower sides of the first ring body, and each second ring body has a second notch in the circumferential direction. The two first protrusions extend into the second notches of the two second ring bodies respectively, so as to restrict the rotation of each second ring body relative to the first ring body and prevent the two second notches from aligning with the first notches in the axial direction. Lubricating oil flows to the outside of the piston ring through the first notch and the two second notches. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of a piston ring with circumferential positioning function for engine, used in an embodiment of the present invention, for the engagement of piston ring, piston, and cylinder.

[0019] Figure 2 yes Figure 1 A magnified view of part M in the middle;

[0020] Figure 3 yes Figure 1 A magnified view of part N in the middle;

[0021] Figure 4 This is a three-dimensional schematic diagram of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention;

[0022] Figure 5 This is a three-dimensional schematic diagram of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention, showing that two first protrusions of the first ring body of the piston ring for an engine respectively extend into the second notches of two second ring bodies.

[0023] Figure 6This is a three-dimensional schematic diagram of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention, showing that the second protrusions of the two second ring bodies of the piston ring with circumferential positioning function respectively extend into the first notch of the first ring body;

[0024] Figure 7 This is a three-dimensional schematic diagram of the first ring body of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention;

[0025] Figure 8 This is a front view of the first notch of the first ring body of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention.

[0026] Figure 9 yes Figure 7 A partial view of section B in the middle;

[0027] Figure 10 This is a three-dimensional schematic diagram of the upper second ring body of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention.

[0028] Figure 11 This is a front view of the second notch of the upper second ring body of the piston ring for an engine with circumferential positioning function according to an embodiment of the present invention.

[0029] Figure 12 yes Figure 10 A magnified view of part A in the middle;

[0030] Figure 13 This is a three-dimensional schematic diagram of the second ring body located on the lower side of the piston ring for an engine with circumferential positioning function according to an embodiment of the present invention.

[0031] Figure 14 This is a front view of the second notch of the second ring body located on the lower side of the piston ring for an engine with circumferential positioning function according to an embodiment of the present invention; and

[0032] Figure 15 yes Figure 13 A magnified view of part C in the middle.

[0033] In the picture:

[0034] 1-First ring body; 11-First notch; 12-First protrusion; 13-Arch-shaped protrusion;

[0035] 2-Second ring body; 21-Second notch; 22-Second protrusion; 23-Matching arc-shaped protrusion; 24-Groove;

[0036] 3-Piston; 31-First annular groove; 32-Second annular groove; 33-Third annular groove; 34-Fourth annular groove;

[0037] 4-Cylinder block;

[0038] 5-Cavity. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0040] According to one aspect of the invention, a piston ring for an engine with circumferential positioning function is provided, comprising: a first ring body, installed between a piston and the inner wall of a cylinder, the first ring body having a first notch in the circumferential direction, and two first protrusions extending in the axial direction formed on the upper and lower sides of the first ring body respectively; and two second ring bodies, respectively installed on the upper and lower sides of the first ring body, each second ring body having a second notch in the circumferential direction, the two first protrusions extending into the second notches of the two second ring bodies respectively, to restrict the rotation of each second ring body relative to the first ring body.

[0041] Figure 1 This is a cross-sectional view of a piston ring with circumferential positioning function for engine, used in an embodiment of the present invention, for the engagement of piston ring, piston, and cylinder. Figure 2 yes Figure 1 A magnified view of part M in the middle; Figure 3 yes Figure 1 A magnified view of part N in the middle; Figure 4 This is a three-dimensional schematic diagram of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention; Figure 5 This is a three-dimensional schematic diagram of a piston ring for an engine with circumferential positioning function, wherein two first protrusions of the first ring body extend into the second notches of two second ring bodies, respectively, according to an embodiment of the present invention.

[0042] According to an exemplary embodiment of the present invention, please refer to Figures 1-5 A piston ring for an engine with circumferential positioning function is provided, comprising a first ring body 1 and two second ring bodies 2. The first ring body 1 is installed between the piston 3 and the inner wall of the cylinder 4. The first ring body 1 has a first notch 11 in the circumferential direction, and two first protrusions 12 extending in the axial direction are formed on the upper and lower sides of the first ring body 1, respectively. The two second ring bodies 2 are respectively installed on the upper and lower sides of the first ring body 1. Each second ring body 2 has a second notch 21 in the circumferential direction. The two first protrusions 12 extend into the second notches 21 of the two second ring bodies 2, respectively, to restrict the rotation of each second ring body 2 relative to the first ring body 1 and prevent the two second notches 21 from aligning with the first notch 11 in the axial direction. Lubricating oil flows to the outside of the piston ring through the first notch 11 and the two second notches 21.

[0043] In this embodiment, two first protrusions 12 extending in the axial direction are formed on the upper and lower sides of the first ring body 1, and each second ring body 2 has a second notch 21 in the circumferential direction. The two first protrusions 12 extend into the second notches 21 of the two second ring bodies 2 respectively, so as to restrict the rotation of each second ring body 2 relative to the first ring body 1 and prevent the two second notches 21 from being aligned with the first notch 11 in the axial direction. The lubricating oil flows to the outside of the piston ring through the first notch 11 and the two second notches 21.

[0044] It should be noted that in this embodiment, the first notch 11 and the two second notches 21 are distributed circumferentially. Furthermore, due to the three-layer design, the piston ring has increased thickness, making it easier to meet the requirements of efficient engine operation under high load conditions, and improving high sealing, high oil control, and low friction capabilities. In addition, the piston ring of this embodiment overcomes the ring deformation problem caused by uneven heating and unbalanced thermal expansion on the upper and lower surfaces of a single-piece piston ring, better dispersing heat and improving the sealing effect. It also features a simple structure and convenient installation.

[0045] Figure 7 This is a three-dimensional schematic diagram of the first ring body of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention; Figure 8 This is a front view of the first notch of the first ring body of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention. Figure 9 yes Figure 7 A partial view of part B in the diagram.

[0046] In some exemplary embodiments, reference is made to Figures 7-9 The two first protrusions 12 are symmetrically arranged about the radial extension line of the first ring body 1 where the first notch 11 is located.

[0047] With the above configuration, when the two first protrusions 12 of the first ring body 1 are respectively inserted into the second notches 21 of the two second ring bodies 2, the torque formed by the limiting resistance provided by the two first protrusions 12 to the two second ring bodies 2 in the circumferential direction is balanced.

[0048] Figure 6 This is a three-dimensional schematic diagram of a piston ring for an engine with circumferential positioning function, in an embodiment of the present invention, showing that the second protrusions of the two second ring bodies extend into the first notch of the first ring body.

[0049] In some exemplary embodiments, reference is made to Figure 4 as well as Figure 6 Each second ring body 2 has a second protrusion 22 extending in the axial direction on the side facing the first ring body 1. The two second protrusions 22 extend into the first notch 11 from the upper and lower sides of the first ring body 1, respectively, to restrict the rotation of each second ring body 2 relative to the first ring body 1.

[0050] In this embodiment, each second ring body 2 has a second protrusion 22 extending in the axial direction on the side facing the first ring body 1. The two second protrusions 22 extend into the first notch 11 from the upper and lower sides of the first ring body 1, respectively, to further restrict the rotation of each second ring body 2 relative to the first ring body 1.

[0051] Figure 10 This is a three-dimensional schematic diagram of the upper second ring body of a piston ring for an engine with circumferential positioning function according to an embodiment of the present invention. Figure 11 This is a front view of the second notch of the upper second ring body of the piston ring for an engine with circumferential positioning function according to an embodiment of the present invention. Figure 12 yes Figure 10 A magnified view of part A in the middle; Figure 13 This is a three-dimensional schematic diagram of the second ring body located on the lower side of the piston ring for an engine with circumferential positioning function according to an embodiment of the present invention. Figure 14 This is a front view of the second notch of the second ring body located on the lower side of the piston ring for an engine with circumferential positioning function according to an embodiment of the present invention. Figure 15 yes Figure 13 A magnified view of part C in the middle.

[0052] In some exemplary embodiments, reference is made to Figures 7-15 The first ring body 1 has arc-shaped protrusions 13 extending circumferentially on its upper and lower sides. The cross-sectional area of ​​the arc-shaped protrusions 13 is constructed as a trapezoid that gradually decreases towards the first ring body 1. The two arc-shaped protrusions 13 are symmetrically arranged about the radial extension line of the first ring body 1 where the first notch 11 is located. Each second ring body 2 has a matching arc-shaped protrusion 23 on its semicircle opposite to the second notch 21. The matching arc-shaped protrusions 23 of the two second ring bodies 2 are respectively engaged with the two arc-shaped protrusions 13 of the first ring body 1 to restrict the two second ring bodies 2 from moving in the axial direction relative to the first ring body 1.

[0053] In this embodiment, the cross-sectional area of ​​the two arc-shaped protrusions 13 located on the upper and lower sides of the first ring body 1 is constructed as a trapezoid that gradually decreases toward the first ring body 1. The matching arc-shaped protrusions 23 of the two second ring bodies 2 are respectively combined with the two arc-shaped protrusions 13 of the first ring body 1 to restrict the two second ring bodies 2 from moving in the axial direction relative to the first ring body 1.

[0054] Furthermore, through the above-mentioned arrangement, the positive torsional force and elastic force formed between the two second rings 2 and the first ring 1 enhance the axial connection between the two second rings 2 and the first ring 1, resulting in better sealing and stability.

[0055] In some exemplary embodiments, reference is made to Figure 7 , Figure 10 as well as Figure 13 Two arc-shaped protrusions 13 extend 180° from the position of the first notch 11 in opposite circumferential directions, respectively. They cooperate with arc-shaped protrusions 23 extending 180° from the position of the second protrusion 22 in the circumferential direction and opposite to the second notch 21. The two arc-shaped protrusions 23 of the two second ring bodies 2 are respectively combined with the two arc-shaped protrusions 13 located on both sides of the first ring body 1, so that the first ring body 1 and the two second ring bodies 2 respectively form a complete circumferential surface in the circumferential direction.

[0056] With the above configuration, the matching arc-shaped protrusions 23 of the two second ring bodies 2 are respectively combined with the arc-shaped protrusions 13 of the first ring body 1, so that the outer wall surface of the piston ring after the two second ring bodies 2 are combined with the first ring body 1 has the same axial dimension at every point along the circumferential direction, and forms a complete circumferential surface, preventing lubricating oil from flowing to the outside of the piston ring and improving the sealing effect of the piston ring on the internal lubricating oil.

[0057] In some exemplary embodiments, reference is made to Figures 2-3 The annular outer wall of the first ring body 1 is configured to bulge radially outward in the middle part, and the annular outer wall of each second ring body 2 is configured to tilt radially inward toward the first ring body 1. The first ring body 1 and the second ring body 2 have the same maximum outer diameter, so that the stacked first ring body 1, the two second ring bodies 2 and the inner wall of the cylinder body 4 form a cavity 5 for storing lubricating oil.

[0058] With the above arrangement, the first ring 1 and two second rings 2 are stacked and installed between the piston 3 and the cylinder 4, forming cavities 5 for storing lubricating oil between the first ring 1 and the inner wall of the cylinder 4. The oil storage cavities 5 formed between the first ring 1 and the two second rings 2 and the inner wall of the cylinder 4 effectively improve the lubrication of the piston rings at top dead center, while preventing the upward flow of lubricating oil. This improves the problem of carbon deposits entering the crankcase, increasing the life of the lubricating oil and preventing wear of the cylinder 4 that may be caused by carbon deposits.

[0059] It should be noted that, in this embodiment, the conical angle of the outer annular wall of the second ring 2 is 20°-70°. Preferably, it is 45°.

[0060] In some exemplary embodiments, reference is made to Figures 2-3 as well as Figure 7 , Figure 10 , Figure 13 The width of the end of each arc-shaped protrusion 13 that engages with the first ring body 1 in the radial direction is half the maximum width of the first ring body 1 in the radial direction. The width of the end of the arc-shaped protrusion 23 that engages with the first ring body 1 in the axial direction in the radial direction is half the maximum width of the second ring body 2 in the radial direction.

[0061] By adopting the above configuration, the contact area between the two arc-shaped protrusions 23 of the two second ring bodies 2 and the two arc-shaped protrusions 13 of the first ring body 1 is increased, so as to improve the contact strength between the two second ring bodies 2 and the first ring body 1 in the axial direction, and further prevent the two second ring bodies 2 from moving relative to the first ring body 1 in the axial direction.

[0062] In some exemplary embodiments, reference is made to Figures 2-3 The outer side of the upper surface of the second ring body 2 located away from the first ring body 1 has a groove 24 extending in the circumferential direction. This causes the second ring body 2 located on the upper side to generate torque under the action of the piston 3 during the movement inside the cylinder body 4, so as to stick tightly to the inner wall of the cylinder body 4 and increase the contact force between the second ring body 2 located on the upper side and the inner wall of the cylinder body 4.

[0063] In this embodiment, a groove 24 extending in the circumferential direction is formed on the outer side of the upper surface of the second ring 2 located on the upper side of the first ring 1 away from the first ring 1. As the second ring 2 moves inside the cylinder 4, the torque generated between the two sides of the second ring 2 facing each other under the action of the piston 3 is not equal. As a result, the second ring 2 generates torque, which makes the second ring 2 stick tightly to the inner wall of the cylinder 4, increasing the contact force between the second ring 2 and the inner wall of the cylinder 4.

[0064] In some exemplary embodiments, the coefficient of thermal expansion of the second ring 2 located on the upper side, a2, is greater than the coefficient of thermal expansion of the first ring 1, a1, and the coefficient of thermal expansion of the second ring 2 located on the lower side, a3.

[0065] In this embodiment, the upper second ring 2 is located near the combustion chamber, has a large surface heat, and is typically in a high-temperature environment. The first ring 1 further seals the gas and controls oil, and acts as a buffer between the two second rings 2 located on the upper and lower sides. The lower second ring 2 mainly functions to control oil and further seal the gas. Based on the installation positions and functions of the first ring 1 and the two second rings 2, the thermal expansion coefficient a2 of the upper second ring 2 is greater than that of the first ring 1 (a1), which is greater than that of the lower second ring 2 (a3), to meet the operating requirements of the first ring 1 and the two second rings 2.

[0066] According to an exemplary embodiment of the present invention, referring to Figures 1-3 An engine system is provided, including a cylinder block 4, a piston 3, and piston rings with circumferential positioning function as described in the above embodiments. The piston 3 is installed inside the cylinder block 4. The piston rings with circumferential positioning function as described in the above embodiments are installed between the piston 3 and the cylinder block 4.

[0067] In this embodiment, the piston ring with circumferential positioning function for the engine described in the above embodiment is installed between the piston 3 and the cylinder 4 to prevent the lubricating oil inside the piston ring from flowing to the outside of the piston ring.

[0068] It should be noted that, in this embodiment, the piston 3 has a first annular groove 31, a second annular groove 32, a third annular groove 33, and a fourth annular groove 34 formed on it, suitable for mounting the piston ring. For example, in this embodiment of the invention, the piston ring is mounted inside the first annular groove 31.

[0069] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A piston ring for an engine with circumferential positioning function, comprising: The first ring body (1) is installed between the piston (3) and the inner wall of the cylinder (4). The first ring body (1) has a first notch (11) in the circumferential direction. The first ring body (1) has two first protrusions (12) extending in the axial direction on its upper and lower sides respectively. as well as Two second ring bodies (2) are respectively installed on the upper and lower sides of the first ring body (1). Each second ring body (2) has a second notch (21) in the circumferential direction. Two first protrusions (12) extend into the second notches (21) of the two second ring bodies (2) respectively to restrict each second ring body (2) from rotating relative to the first ring body (1). Each second ring body (2) has a second protrusion (22) extending in the axial direction on the side facing the first ring body (1). The first ring body (1) has arc-shaped protrusions (13) extending in the circumferential direction on its upper and lower sides respectively. The two arc-shaped protrusions (13) are symmetrically arranged about the radial extension line of the first ring body (1) where the first notch (11) is located. Each second ring body (2) has a matching arc-shaped protrusion (23) adapted to the arc-shaped protrusions (13) on its semicircle opposite to the second notch (21). The two arc-shaped protrusions (13) extend 180° from the position of the first notch (11) in opposite circumferential directions respectively. The matching arc-shaped protrusions (23) extend 180° from the position of the second protrusion (22) in the circumferential direction and are opposite to the second notch (21). The matching arc-shaped protrusions (23) of the two second ring bodies (2) are respectively combined with the two arc-shaped protrusions (13) located on both sides of the first ring body (1), so that the first ring body (1) and the two second ring bodies (2) respectively form a complete circumferential surface in the circumferential direction.

2. The piston ring for an engine with circumferential positioning function according to claim 1, wherein, The two first protrusions (12) are symmetrically arranged about the radial extension of the first ring body (1) where the first notch (11) is located.

3. The piston ring for an engine having a circumferential positioning function according to claim 1, wherein, The two second protrusions (22) extend into the first notch (11) from the upper and lower sides of the first ring body (1), respectively.

4. The piston ring for an engine having a circumferential positioning function according to claim 3, wherein The cross-sectional area of ​​the arcuate protrusion (13) is configured as a trapezoid that gradually decreases toward the first annular body (1).

5. The piston ring for an engine having a circumferential positioning function according to claim 4, wherein, The annular outer wall of the first ring body (1) is configured to bulge radially outward in the middle part, and the annular outer wall of each second ring body (2) is configured to be radially inward toward the first ring body (1), and the maximum outer diameter of the first ring body (1) and the second ring body (2) is the same, so that the first ring body (1) and the two second ring bodies (2) stacked together form a cavity (5) for storing lubricating oil with the inner wall of the cylinder body (4).

6. The piston ring for an engine having a circumferential positioning function according to claim 5, wherein The width of the end of each of the arcuate protrusions (13) that is joined to the first ring body (1) in the radial direction is 1 / 2 of the maximum width of the first ring body (1) in the radial direction; The width of the end of the mating arc-shaped protrusion (23) that engages with the first ring body (1) in the axial direction is 1 / 2 of the maximum width of the second ring body (2) in the radial direction.

7. The piston ring for an engine having a circumferential positioning function according to any one of claims 1 to 6, wherein The outer side of the upper surface of the second ring (2) located on the upper side away from the first ring (1) is formed with a groove (24) extending in the circumferential direction, so that when the second ring (2) located on the upper side moves inside the cylinder (4), under the action of the piston (3), the second ring (2) located on the upper side generates torque to stick to the inner wall of the cylinder (4) and increase the contact force between the second ring (2) located on the upper side and the inner wall of the cylinder (4).

8. The piston ring for an engine with circumferential positioning function according to claim 1, wherein the coefficient of thermal expansion a2 of the second ring body (2) located on the upper side is greater than the coefficient of thermal expansion a1 of the first ring body (1) and the coefficient of thermal expansion a3 of the second ring body (2) located on the lower side.

9. An engine system comprising: Cylinder block (4); Piston (3) is installed inside the cylinder (4); as well as The piston ring for an engine with circumferential positioning function as described in any one of claims 1-8 is installed between the piston (3) and the cylinder (4).

Images