Piston rings

Abstract

To remove deposits accumulated on a groove bottom of a ring groove.SOLUTION: A piston ring 1 that is fitted into a ring groove of a piston, comprises a first projection part 4A and a second projection part 4B projecting inward in a radial direction D1 of the piston ring 1. In the piston ring 1, the first projection part 4A and the second projection part 4B project inside the piston ring 1 in the radial direction D1, so that when the piston ring 1 rotates along the ring groove due to the reciprocating motion of the piston relative to a cylinder, deposits accumulated on the groove bottom of the ring groove can be scraped off by the first projection part 4A and the second projection part 4B. Consequently, deposits accumulated on the groove bottom of the ring groove can be removed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a piston ring that is fitted into a ring groove of a piston. [Background technology]

[0002] Patent Document 1 describes a piston ring that is fitted into a ring groove of a piston. In this piston ring, in order to remove deposits that have accumulated between the ring groove and the piston ring, a first recessed portion that extends radially from the outer peripheral surface to just before the inner peripheral surface and a second recessed portion that extends radially from the inner peripheral surface to just before the outer peripheral surface are provided on the upper end surface of the piston ring. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-241879 Summary of the Invention [Problem to be solved by the invention]

[0004] The piston ring described in Patent Document 1 can only remove deposits that are on the upper end surface side of the piston ring among deposits that have accumulated in the ring groove. In other words, it cannot remove deposits that have accumulated on the groove bottom of the ring groove. As a result, the deposits that have accumulated on the groove bottom of the ring groove solidify, which prevents the function of the piston ring from being maintained over the long term, and it is not possible to sufficiently suppress deterioration of engine performance over time.

[0005] Therefore, an object of the present invention is to provide a piston ring that can remove deposits that accumulate on the groove bottom of the ring groove. [Means for solving the problem]

[0006] The piston ring according to the present invention is a piston ring to be fitted into a ring groove of a piston, and includes a protruding portion that protrudes radially inward of the piston ring.

[0007] In this piston ring, the protruding portion protrudes radially inward, so that when the piston ring rotates circumferentially along the ring groove due to the reciprocating motion of the piston relative to the cylinder, the protruding portion can scrape off deposits that accumulate on the groove bottom of the ring groove, thereby making it possible to remove deposits that accumulate on the groove bottom of the ring groove.

[0008] The protruding portions may be provided at both ends of the piston ring that form the gap, and the amount of radial inward protrusion of the protruding portions may increase toward the gap. In this piston ring, the protruding portions are provided at both ends of the piston ring that form the gap, and the amount of radial inward protrusion of the protruding portions increases toward the gap. As a result, deposits accumulated on the groove bottom of the ring groove are scraped off by the end faces of the protruding portions on the gap side. The deposits scraped off by the protruding portions are then discharged from the gap to the outside of the ring groove. This allows deposits accumulated on the groove bottom of the ring groove to be more appropriately removed.

[0009] The protruding portion may have a notch extending in the circumferential direction of the piston ring. In this piston ring, the notch formed in the protruding portion forms a space that communicates between an area on the abutment side of the protruding portion and an area on the opposite side of the abutment of the protruding portion. This allows deposits present on the opposite side of the abutment of the protruding portion to move to the abutment through the notch. This allows deposits that accumulate on the groove bottom of the ring groove to be easily discharged from the abutment to the outside of the ring groove. [Effects of the Invention]

[0010] According to the present invention, deposits that accumulate on the groove bottom of the ring groove can be removed. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a plan view of the piston ring according to the embodiment. [Figure 2] 2 is a cross-sectional view showing a state in which the piston ring shown in FIG. 1 is fitted into a ring groove of a piston. FIG. [Figure 3] 3(a) is a perspective view showing one end of the piston ring shown in FIG. 1, and FIG. 3(b) is a perspective view showing the other end of the piston ring shown in FIG. [Figure 4] FIG. 4(a) is a perspective view showing one end of a modified piston ring, and FIG. 4(b) is a perspective view showing the other end of the modified piston ring. [Figure 5] FIG. 5(a) is a perspective view showing one end of the modified piston ring, and FIG. 4(b) is a perspective view showing the other end of the modified piston ring. [Figure 6] FIG. 10 is a plan view of a modified piston ring. [Figure 7] FIG. 10 is a plan view of a modified piston ring. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements will be designated by the same reference numerals, and redundant description will be omitted.

[0013] FIG. 1 is a plan view of a piston ring according to an embodiment. FIG. 2 is a cross-sectional view showing a state in which the piston ring shown in FIG. 1 is fitted into a ring groove of a piston. FIG. 3(a) is a perspective view showing one end of the piston ring shown in FIG. 1, and FIG. 3(b) is a perspective view showing the other end of the piston ring shown in FIG. 1. As shown in FIGS. 1 to 3, a piston ring 1 according to this embodiment is a component that is fitted into a ring groove 11 of a piston 10 that reciprocates relative to a cylinder (not shown). The piston ring 1 is formed in a substantially annular shape with a portion of the annular ring cut out at a joint 2. The shape of such a piston ring 1 is also called a notched annular shape, an arc-shaped shape, a C-shape, etc. The cut-out portion of the piston ring 1 becomes the joint 2.

[0014] The piston ring 1 has an inner peripheral surface 1a facing inward in the radial direction D1 of the piston ring 1, an outer peripheral surface 1b facing outward in the radial direction D1 of the piston ring 1, a first surface 1c facing one side in the thickness direction D2 of the piston ring 1, and a second surface 1d facing the other side in the thickness direction D2 of the piston ring 1. First surface 1c The piston ring 1 has a second surface 1d facing the radial direction D3 (the side opposite to the center), and a first end surface 1e and a second end surface 1f forming a butt joint 2. The inner side of the piston ring 1 in the radial direction D1 is the direction toward the center of the piston ring 1 in the radial direction D1, and the outer side of the piston ring 1 in the radial direction D1 is the direction toward the opposite side from the center of the piston ring 1 in the radial direction D1. The thickness direction D2 of the piston ring 1 is the direction in which the first surface 1c and the second surface 1d face each other, and is also the direction in which the piston 10 reciprocates relative to the cylinder. The butt joint 2 is formed between the first end surface 1e and the second end surface 1f. Of both end portions of the piston ring 1 in the circumferential direction D3, a portion including the first end surface 1e is referred to as a first end portion 1g, and a portion including the second end surface 1f is referred to as a second end portion 1h.

[0015] When fitted in the ring groove 11, the inner peripheral surface 1a of the piston ring 1 faces the groove bottom 12 of the ring groove 11. The groove bottom 12 of the ring groove 11 is the bottom in the depth direction of the ring groove 11. The depth direction of the ring groove 11 is also the radial direction D1 of the piston ring 1 fitted in the ring groove 11. When the piston ring 1 is fitted in the ring groove 11, the outer peripheral surface 1b of the piston ring 1 abuts against the inner peripheral surface of the cylinder.

[0016] The piston ring 1 includes a piston ring body 3, a first protruding portion 4A, and a second protruding portion 4B.

[0017] The piston ring body 3 is a portion that forms the main body of the piston ring 1. The piston ring body 3 is formed to have the same cross section over the entire area in the circumferential direction D3 of the piston ring 1. In other words, the width of the piston ring body 3 in the radial direction D1 is the same over the entire area in the circumferential direction D3 of the piston ring 1. The piston ring body 3 is formed in a substantially annular shape with a portion of the annular ring cut out at the joint 2, similar to the piston ring 1.

[0018] The first protruding portion 4A and the second protruding portion 4B are portions that protrude inward in the radial direction D1 of the piston ring 1. In other words, the first protruding portion 4A and the second protruding portion 4B protrude inward in the radial direction D1 from the piston ring main body 3. The first protruding portion 4A is provided at a first end portion 1g of the piston ring 1, and a first end face 1e is formed by the piston ring main body 3 and the first protruding portion 4A. In addition, the second protruding portion 4B is provided at a second end portion 1h of the piston ring 1, and a second end face 1f is formed by the piston ring main body 3 and the second protruding portion 4B.

[0019] The first overhanging portion 4A and the second overhanging portion 4B have increasing inward overhang amounts in the radial direction D1 toward the butt joint 2. That is, at the first end 1g and the second end 1h of the piston ring 1, the first overhanging portion 4A and the second overhanging portion 4B increase the width of the piston ring 1 in the radial direction D1 and decrease the inner diameter of the piston ring 1 toward the butt joint 2. At the first end face 1e and the second end face 1f that form the butt joint 2, the width of the piston ring 1 in the radial direction D1 is greatest and the inner diameter of the piston ring 1 is smallest.

[0020] A first notch 4Aa extending in the circumferential direction D3 of the piston ring 1 is formed in the first overhanging portion 4A, and a second notch 4Ba extending in the circumferential direction D3 of the piston ring 1 is formed in the second overhanging portion 4B. When the piston ring 1 is fitted in the ring groove 11, the first notch 4Aa forms a space that communicates between an area on the butt joint 2 side of the first overhanging portion 4A and an area on the opposite side of the butt joint 2 of the first overhanging portion 4A. When the piston ring 1 is fitted in the ring groove 11, the second notch 4Ba forms a space that communicates between an area on the butt joint 2 side of the second overhanging portion 4B and an area on the opposite side of the butt joint 2 of the second overhanging portion 4B. For this reason, the first notch 4Aa extends to a first end face 1e of the piston ring 1, and the first end face 1e is cut out by the first notch 4Aa. The second notch 4Ba extends to the second end face 1f of the piston ring 1, and the second end face 1f is cut out by the second notch 4Ba.

[0021] The first notch 4Aa is formed in an inner peripheral end portion 4Ab of the first overhanging portion 4A on the inside in the radial direction D1, and cuts out the inner peripheral surface 1a of the piston ring 1. The second notch 4Ba is formed in an inner peripheral end portion 4Bb of the second overhanging portion 4B on the inside in the radial direction D1, and cuts out the inner peripheral surface 1a of the piston ring 1. When the piston ring 1 is fitted in the ring groove 11, the first notch 4Aa forms a space between the groove bottom 12 of the ring groove 11 and the piston ring 1, which connects an area on the butt 2 side of the first overhanging portion 4A to an area on the opposite side of the butt 2 of the first overhanging portion 4A. When the piston ring 1 is fitted in the ring groove 11, the second notch 4Ba forms a space between the groove bottom 12 of the ring groove 11 and the piston ring 1, which connects an area on the butt 2 side of the second overhanging portion 4B to an area on the opposite side of the butt 2 of the second overhanging portion 4B.

[0022] The shapes of the first notch 4Aa and the second notch 4Ba are not particularly limited, but it is preferable that the first notch 4Aa and the second notch 4Ba are different from each other. In this embodiment, the first notch 4Aa has a shape obtained by cutting out the center of the first protruding portion 4A in the thickness direction D2 of the piston ring 1. 、The second notch 4Ba is formed by cutting out both ends of the second protruding portion 4B in the thickness direction D2. As a result, the first end face 1e is formed in a concave shape with a central portion of the inner circumferential surface 1a in the thickness direction D2 being concave, and the second end face 1f is formed in a convex shape with both ends of the inner circumferential surface 1a in the thickness direction D2 being concave. to It is formed.

[0023] Furthermore, it is more preferable that the length of the inner circumferential surface 1a at the first end face 1e of the first protrusion portion 4A and the length of the inner circumferential surface 1a at the second end face 1f of the second protrusion portion 4B are approximately the same so that the rotational resistance of the piston ring 1 relative to the ring groove 11 to one side in the circumferential direction D3 does not diverge from the rotational resistance to the other side.

[0024] As described above, in the piston ring 1 according to the present embodiment, the first overhanging portion 4A and the second overhanging portion 4B overhang inward in the radial direction D1 of the piston ring 1, and therefore, when the piston ring 1 rotates in the circumferential direction D3 along the ring groove 11 due to the reciprocating motion of the piston 10 relative to the cylinder, the first overhanging portion 4A and the second overhanging portion 4B can scrape off deposits accumulated on the groove bottom 12 of the ring groove 11. This makes it possible to remove deposits accumulated on the groove bottom 12 of the ring groove 11.

[0025] Furthermore, in this piston ring 1, the first overhanging portion 4A and the second overhanging portion 4B are provided at the first end 1g and the second end 1h of the piston ring 1 that form the butt joint 2, and the amount of inward overhang of the first overhanging portion 4A and the second overhanging portion 4B in the radial direction D1 increases toward the butt joint 2. Therefore, deposits accumulated on the groove bottom 12 of the ring groove 11 are scraped off by the first end face 1e and the second end face 1f, which are the end faces of the first overhanging portion 4A and the second overhanging portion 4B on the butt joint 2 side. The deposits scraped off by the first overhanging portion 4A and the second overhanging portion 4B are discharged from the butt joint 2 to the outside of the ring groove 11. This makes it possible to more appropriately remove deposits accumulated on the groove bottom 12 of the ring groove 11.

[0026] Furthermore, in this piston ring 1, the first notch 4Aa and the second notch 4Ba formed in the first overhanging portion 4A and the second overhanging portion 4B form a space that communicates between the area on the butt 2 side of the first overhanging portion 4A and the second overhanging portion 4B and the area on the opposite side of the butt 2 of the first overhanging portion 4A and the second overhanging portion 4B. This allows deposits present on the opposite side of the butt 2 of the first overhanging portion 4A and the second overhanging portion 4B to move to the butt 2 through the first notch 4Aa and the second notch 4Ba. This allows deposits that accumulate on the groove bottom 12 of the ring groove 11 to be easily discharged from the butt 2 to the outside of the ring groove 11.

[0027] Furthermore, in this piston ring 1, since the first notch 4Aa and the second notch 4Ba are formed in the inner circumferential end portion 4Ab and the inner circumferential end portion 4Bb, when the piston ring 1 is fitted into the ring groove 11, a space communicating between the region on the abutment 2 side of the first overhanging portion 4A and the region on the opposite side of the abutment 2 of the first overhanging portion 4A can be formed between the groove bottom 12 of the ring groove 11 and the piston ring 1. This allows deposits present on the opposite side of the abutment 2 of the first overhanging portion 4A and the second overhanging portion 4B to be easily moved to the abutment 2.

[0028] If the shapes of the first notch 4Aa and the second notch 4Ba were different, when the piston ring 1 rotated only in one direction in the circumferential direction D3, a region would be generated in which deposits accumulated on the groove bottom 12 of the ring groove 11 could not be scraped off. Therefore, in this piston ring 1, the length of the inner circumferential surface 1a at the first end face 1e of the first overhanging portion 4A and the length of the inner circumferential surface 1a at the second end face 1f of the second overhanging portion 4B are made substantially the same. This makes the rotational resistance of the piston ring 1 fitted in the ring groove 11 toward one side in the circumferential direction D3 and the rotational resistance toward the other side in the circumferential direction D3 substantially the same, allowing the piston ring 1 to rotate in either direction in the circumferential direction D3. As a result, deposits accumulated on the groove bottom 12 of the ring groove 11 can be more appropriately scraped off.

[0029] The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment, and may be modified or applied to other things within the scope that does not change the gist described in each claim.

[0030] For example, in the above embodiment, the protruding portions are described as being cut out, but the first protruding portion 24A and the second protruding portion 24B may not be cut out, as in the piston ring 21 shown in Fig. 4. In this case, the first end face 21e and the second end face 21f, which are both end faces of the piston ring 21, are also not cut out.

[0031] Furthermore, in the above embodiment, the specific shapes of the notches formed in the protruding portions have been described, but the shapes of the notches are not particularly limited. For example, as in the piston ring 31 shown in FIG. 5, the first notch 34Aa formed in the first protruding portion 34A may be shaped by cutting out one end of the first protruding portion 34A in the thickness direction D2, and the second notch 34Ba may be shaped by cutting out the other end of the second protruding portion 34B in the thickness direction D2. In this case, the first end face 31e is formed in an L-shape with one end of the inner circumferential surface 31a in the thickness direction D2 extending inward in the radial direction D1, and the second end face 31f is formed in an L-shape with the other end of the inner circumferential surface 31a in the thickness direction D2 extending inward in the radial direction D1. Formed into It has been done.

[0032] In addition, although the above embodiment has been described as including two protruding portions, the number of protruding portions is not particularly limited. For example, as in the piston ring 41 shown in Fig. 6, of the first end portion 41g and the second end portion 41h, which are both end portions of the piston ring 41, a protruding portion 44 may be formed only at the first end portion 41g, and no protruding portion may be formed at the second end portion 41h. In this case, the first end surface 41e of the piston ring 41 is formed by the piston ring body portion 3 and the protruding portion 44, while the second end surface 41f of the piston ring 41 is formed only by the piston ring body portion 3.

[0033] In the above embodiment, the protruding portion is described as being formed at the end of the piston ring, but the protruding portion may be formed at any position on the piston ring as long as it protrudes radially inward. For example, as in the piston ring 51 shown in FIG. 7 , the protruding portion 54 may be formed at a position other than the first end 51g and the second end 51h, which are both end portions of the piston ring 51. In this case, the first end face 51e and the second end face 51f, which are both end faces of the piston ring 51, are formed only by the piston ring body 3.

[0034] In the above embodiment, the amount of radial inward projection of the projection portion increases toward the abutment, but the shape of the projection portion is not particularly limited. For example, as in the piston ring 51 shown in Fig. 7, the projection portion 54 may be rectangular and project radially inward. [Explanation of symbols]

[0035] 1...piston ring, 1a...inner peripheral surface, 1b...outer peripheral surface, 1c...first surface, 1d...second surface, 1e...first end face, 1f...second end face, 1g...first end, 1h...second end, 2...butt, 3...piston ring main body, 4A...first protruding portion, 4Aa...first notch, 4Ab...inner peripheral end, 4B...second protruding portion, 4Ba...second notch, 4Bb...inner peripheral end, 10...piston, 11...ring groove, 12...groove bottom, 21...piston ring, 21e...first end face, 21f...second end face, 24A...first protruding portion, 24B...second Protrusion portion, 31...piston ring, 31a...inner circumferential surface, 31e...first end face, 31f...second end face, 34A...first protrusion portion, 34Aa...first notch, 34B...second protrusion portion, 34Ba...second notch, 41...piston ring, 41e...first end face, 41f...second end face, 41g...first end portion, 41h...second end portion, 44...protrusion portion, 51...piston ring, 51e...first end face, 51f...second end face, 51g...first end portion, 51h...second end portion, 54...protrusion portion, D1...radial direction, D2...thickness direction, D3...circumferential direction.

Claims

1. A piston ring fitted into a ring groove of a piston, a first protruding portion and a second protruding portion protruding radially inwardly of the piston ring; a first end surface and a second end surface that form a gap; the first protruding portion has a first notch provided at a first end portion including the first end face and extending in a circumferential direction of the piston ring, the second protruding portion has a second notch provided at a second end portion including the second end face and extending in a circumferential direction of the piston ring, The first end surface and the second end surface have different shapes. Piston ring.

2. The amount of protrusion of the first protruding portion and the second protruding portion toward the radially inward direction increases toward the abutment.

2. The piston ring according to claim 1.

3. The first notch and the second notch have different shapes. The piston ring according to claim 1 or 2.

4. The first notch and the second notch are located at different positions in the thickness direction of the piston ring. The piston ring according to any one of claims 1 to 3.

5. a length of an inner circumferential surface of the piston ring at the first end surface of the first protruding portion and a length of the inner circumferential surface of the second protruding portion at the second end surface are substantially the same; The piston ring according to any one of claims 1 to 4.

6. The first end surface is formed in a concave shape such that a central portion of an inner peripheral surface of the piston ring in a thickness direction of the piston ring is concave, The second end surface is formed in a convex shape with both end portions of the inner circumferential surface in the thickness direction concave. The piston ring according to any one of claims 1 to 5.

7. the first notch has a shape obtained by cutting out a central portion of the first protruding portion in a thickness direction of the piston ring, The second cutout has a shape obtained by cutting out both end portions of the second protruding portion in the thickness direction. The piston ring according to any one of claims 1 to 6.

8. the first end surface is formed in an L-shape such that one end of an inner peripheral surface of the piston ring in a thickness direction of the piston ring extends radially inward of the piston ring, The second end surface is formed in an L-shape such that an end portion on the other side in the thickness direction of the inner circumferential surface extends radially inward. The piston ring according to any one of claims 1 to 5.

9. the first notch has a shape formed by cutting out one end of the first protruding portion in the thickness direction of the piston ring, The second cutout has a shape obtained by cutting out an end portion on the other side of the second protruding portion in the thickness direction. The piston ring according to any one of claims 1 to 5 and 8.

10. the first protruding portion and the second protruding portion are not provided in an intermediate portion between the first end and the second end of the piston ring. The piston ring according to any one of claims 1 to 9.

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