JP2582095Y2 - piston ring - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston ring, and more particularly to a piston ring mounted on a piston of an internal combustion engine or a compressor and having a high breaking resistance.

[0002]

2. Description of the Related Art Airtightness against leakage of high-temperature and high-pressure combustion gas generated in a combustion chamber of an internal combustion engine is mainly secured by a piston ring slidingly contacting a cylinder. The piston ring and cylinder expand by being heated by the combustion gas,
It does not reach extremely high temperatures because it is cooled by cooling water or engine oil. However, the piston ring disposed between the high-temperature piston and the cylinder has a small amount of heat conduction to the outside and a small amount of heat radiation, and is exposed to a severe high temperature. In order to absorb the deformation caused by the difference in the coefficient of thermal expansion with respect to the cylinder, it is necessary to provide an appropriate clearance between the piston rings in the piston ring. On the other hand, it is necessary to reduce the amount of blow-by gas generated when the combustion gas in the combustion chamber leaks from the opening gap.

For example, in a known piston ring provided with a right-angle (straight) opening, the combustion chamber side and the crank chamber side communicate with each other through a gap between the right-angle openings, so that gas blows from the combustion chamber to the crank chamber (blow-by). Also, it is difficult to reliably prevent oil from entering the combustion chamber. By improving the piston ring with a right-angled opening, the stepped-up opening where the stepped end of the opening is overlapped up and down, the effect on preventing the blow-through of the piston ring is more effective than the right-angled opening, but it is expected Not as effective.

For example, a piston ring having a double-angled opening structure disclosed in Japanese Utility Model Application Laid-Open No. 60-108748 and Japanese Patent Application Laid-Open No. 60-88850 reduces the amount of blow-by gas generated and the amount of oil consumed. The goal is to improve efficiency. In a double-angled mating opening, a convex portion having a triangular cross section that is tapered in the radial direction extends circumferentially at one end of the mating end, and a concave portion that contacts the convex portion of one mating end has the other mating portion. It is provided at the end.

[0005]

However, in a piston ring having a double-angled mating structure, depending on the shape and finishing accuracy of the contact surface between the convex portion at one mating end and the concave portion at the other mating end. In some cases, the entire surfaces of the convex portions and the concave portions do not contact uniformly. In particular, when the tip of the projection and the root of the recess come into contact during use of the piston ring, a large bending moment is generated at the root of the projection, and therefore, the root of the projection is broken by bending stress. there is a possibility.

Therefore, an object of the present invention is to provide a piston ring which can improve the breakage strength at the end of the abutment during operation of the piston.

[0007]

In the piston ring according to the present invention, a convex portion (2a) projecting in the circumferential direction from one end (2) of the mating opening of the ring main body (1) is provided, and the mating of the ring main body (1) is performed. The other end (3) facing the one end (2) of the mouth is provided with a concave portion (3a) in contact with the convex portion (2a), and the branch portion (2c) of the convex portion (2a) adjacent to the one end (2) of the abutment is provided. ) Is brought into partial contact with the surface of the tip (3b) of the recess (3a). In this piston ring, the protruding portion (2) having a constant width (L) and a contact surface (4) in contact with the opposing concave portion (3a) or convex portion (2a) and parallel to the protruding direction of the convex portion (2a).
b, 3d) are formed with a step (5) at the branch (2c) of the projection (2a) or at the tip (3b) of the recess (3a). Assuming that the protrusion length of the protrusions (2b, 3d) is b and the distance between the protrusion (2a) without the protrusions (2b, 3d) and the recess (3a) is B, B-b = 0.01 to 0.02 mm.

[0008]

When the convex portion (2a) and the concave portion (3a) come into contact with each other, the tip (2d) of the convex portion (2a) is connected to the concave portion (3a).
The projection (2a) and the recess (3a) surely come into contact with each other on the contact surface (4) of the projection (2b, 3d) having a certain width (L) before coming into contact with (a). Projection (2b, 3
d) is a branch (2c) or a concave (3a) of the convex (2a).
Since the contact portion between the convex portion (2a) and the concave portion (3a) is short in distance from the branch portion (2c), the branch portion (2c) of the convex portion (2a) is formed at the front end portion (3b). The bending moment applied to the convex part (2a) is such that the tip part (2d) of the convex part (2a)
a) The bending moment applied to the branch (2c) of the convex portion (2a) when contacting the convex portion (2a) can be made smaller to prevent breakage of the branch portion (2c) of the convex portion (2a) due to surface pressure. Can be. Also, the concave portion (3a) or the convex portion (2a)
By forming the protrusions (2b, 3d) having a constant width (L), the protrusion (2a) and the recess (3a) can be prevented from contacting with a small cross-sectional area.

[0009]

1 and 2 show an embodiment of a piston ring according to the present invention.

As shown in FIG. 1, in the piston ring according to the present invention, a convex portion 2a is formed which protrudes in a circumferential direction from one end 2 of an abutment of a ring main body 1, and is opposed to one end 2 of an abutment of a ring main body 1. The other end 3 is provided with a concave portion 3a that contacts the convex portion 2a. In the embodiment shown in FIG. 1, a projection 2 b that projects in the thickness direction of the ring main body 1 is formed at a branch 2 c of the projection 2 a. The protruding portion 2b is a branch portion 2 of the protruding portion 2a.
c, a contact surface 4 having a constant width L, which is formed with a step 5 and is in contact with the opposing concave portion 3a and is parallel to the projecting direction of the convex portion 2a.
Having. The projecting length of the projecting portion 2b is represented by b, and the projecting portion 2b
Assuming that the distance between the convex portion 2a and the concave portion 3a having no gap is B, B
-B = 0.01 to 0.02 mm. In this embodiment, when the convex portion 2a and the concave portion 3a come into contact with each other, the convex portion 2a
Constant width L before the tip 2d of the
The convex portion 2a and the concave portion 3a surely come into contact with each other on the contact surface 4 of the projecting portion 2b. Since the protrusion 2b is formed at the branch 2c of the protrusion 2a or at the tip 3b of the recess 3a, the contact between the protrusion 2a and the recess 3a has a short distance from the branch 2c. The bending moment applied to the portion 2c can be smaller than the bending moment applied to the branch portion 2c of the convex portion 2a when the tip 2d of the convex portion 2a contacts the concave portion 3a. Breakage due to surface pressure can be prevented. Further, by forming the protrusion 2b having a constant width L to be in contact with the concave portion 3a or the convex portion 2a, it is possible to prevent the convex portion 2a from contacting the concave portion 3a with a small cross-sectional area. In this manner, the protrusion 2b formed at the branch 2c of the protrusion 2a adjacent to the end 2 of the abutment can be brought into partial contact with the surface of the tip 3b of the recess 3a, and the protrusion 2a Tip 2d and recess 3a
Can be prevented from contacting with the root portion 3c. Therefore, a large bending moment of the convex portion 2a caused by the contact between the tip portion 2d and the root portion 3c can be prevented by the projecting portion 2b having the predetermined width L.

Since the projecting length b of the projecting portion 2b is a small amount, the tip portion 2d and the root portion 3c may substantially come into contact with each other. It can be in partial contact with the surface. In the embodiment shown in FIG. 1, the formation of the protruding portion 2b increases the cross-sectional area of the branch portion 2c, so that the strength against bending moment increases and the contact surface 4 having a constant width L.
There is also a point that the surface pressure can be reduced.

FIG. 2 shows another embodiment of the present invention in which a protrusion 3d is formed at the tip 3b of the recess 3a instead of forming the protrusion 2b at the protrusion 2a. The protrusion 3d is formed with a step 5 at the tip 3b of the recess 3a,
a and has a contact surface 4 having a constant width L that is parallel to the direction in which the projection 2a protrudes. Also in this embodiment, B−b = 0.
A relationship of 01 to 0.02 mm is obtained. Further, in this embodiment, when the convex portion 2a and the concave portion 3a come into contact with each other,
Before the tip 2d of the projection 2a comes into contact with the recess 3a, the projection 2 is formed on the contact surface 4 of the projection 3d having a certain width L.
a and the concave portion 3a are surely in contact with each other. The protrusion 3d is the protrusion 2
Since the contact portion between the convex portion 2a and the concave portion 3a is formed at the branch portion 2c of the convex portion 2a or the tip portion 3b of the concave portion 3a, the distance between the convex portion 2a and the concave portion 3a is short from the branch portion 2c. Can be made smaller than the bending moment applied to the branch 2c of the projection 2a when the tip 2d of the projection 2a contacts the recess 3a, and the branch 2c of the projection 2a can be reduced.
Can be prevented from being damaged by surface pressure. Further, by forming the projection 3d having a constant width L to be in contact with the concave portion 3a or the convex portion 2a, it is possible to prevent the convex portion 2a and the concave portion 3a from contacting each other with a small cross-sectional area. As described above, when the convex portion 2a and the concave portion 3a come into contact with each other, the surface of the branch portion 2c of the convex portion 2a and the surface of the distal end portion 3b of the concave portion 3a mainly partially contact with each other, so that a large bending moment is applied to the convex portion 2a. Does not occur. Further, the contact pressure of the contact surface 4 having the constant width L can be reduced.

When a damage test was performed on a large number of piston rings to which the present invention was applied and the convex portion of the conventional multiple piston ring, the breakage load of the piston ring to which the present invention was applied was 25% as compared with the conventional piston ring. It was found that the number increased.

The embodiment of the present invention is not limited to the above-described embodiment, but can be modified. It is apparent that the present invention can be applied to a piston ring mounted on a piston or a shaft of a compressor or the like in addition to a piston ring mounted on a piston of an internal combustion engine.

[0015]

As described above, in the piston ring according to the present invention, the protrusion formed at the abutment of the ring main body is prevented from being damaged, thereby improving the durability and reliability of the piston ring and extending the service life. It is possible to do.

[Brief description of the drawings]

FIG. 1 is a perspective view of a mating end of a piston ring according to an embodiment of the present invention.

FIG. 2 is a perspective view showing another embodiment of the present invention.

[Explanation of symbols]

1. . Ring body, 2. . One end, 2a. . Convex part,
2b. . Protrusion, 2c. . Branch, 2d. . 2. tip, . The other end, 3a. . Recess, 3b. . Tip, 3c. . Root, 3d. . Protrusions, 4. . 4. contact surface; . Step,

Claims (2)

(57) [Scope of request for utility model registration] 1. A convex portion protruding in a circumferential direction from one end of an abutment of a ring main body is provided, a concave portion is provided at the other end of the ring main body opposite to one end of the abutment, and a concave portion is provided at one end of the abutment. In a piston ring in which a branch portion of an adjacent convex portion is in partial contact with the surface of the tip portion of the concave portion, the piston ring has a contact surface of a constant width that is in contact with the opposing concave portion or convex portion and is parallel to the projecting direction of the convex portion. A piston ring in which a protruding part is formed with a step at a branch part of a convex part or a tip part of a concave part. 2. Assuming that the projecting length of the projecting portion is b and the distance between the projecting portion having no projecting portion and the concave portion is B, B−b = 0.0
The piston ring according to claim 1, wherein the diameter is 1 to 0.02 mm.