JPH10103518A - Piston ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a piston ring as capable of minimizing the leakage of high pressure fluid when a piston ring sits on either one of upper surface of lower surface of a piston groove. SOLUTION: In a piston ring 10 by which a piston is installed in such a manner as both mating end parts 11a, 11b engage with each other so as to seal pressurized fluid acting on the one side of the piston, one pair or plural engaging recesses 10i and engaging projection 10b making engagement on both upper and lower surfaces are formed on the outer peripheral side of ring mating end parts 11a, 11b so as to be constituted as capable of fitting to each other and also regulation surfaces for making regulation in the ring radial direction by making mutual contact with its inside surface are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston ring applied to an internal combustion engine, a Stirling engine, a reciprocating compressor, a hydraulic cylinder, and the like. More specifically, a Stirling engine in which the magnitude of the pressure of fluid on both sides of a piston is reversed. The present invention relates to a piston ring suitable for a hydraulic cylinder or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, in order to seal a pressurized fluid acting on one side of a piston 1, a piston ring 2 having both ends engaged at a mouth end 2g as shown in FIG. It is used by being attached to the groove of the piston 1.

As shown in FIG. 1, a piston 1 reciprocates in a cylinder 4 and, in the case of an internal combustion engine, a piston upper chamber 5
By moving the piston 1 by the high-pressure gas generated in the (combustion chamber), a crankshaft (not shown) is rotated via the piston shaft 3 to obtain power.

In the reciprocating compressor, the piston 1 is reciprocated by driving the crankshaft 3 to generate a high-pressure fluid in the piston upper chamber 5. Since there is a clearance t between the piston 1 and the cylinder 4, a plurality of piston rings 2 are mounted on the piston 1 so as to reduce leakage of high-pressure fluid from this clearance.

The abutment ends of the seal ring are formed in L-shape at both ends of the seal ring, and the L-shape portions at both ends are engaged from the thickness direction or the width direction of the seal ring. The technology is disclosed in JP-A-6-213322. However, in this technique, since the portions contributing to the locking of the L-shaped portions at both ends protrude in a direction intersecting the circumferential direction of the seal ring, it is difficult to process the shape of both ends, and the ends are engaged from the circumferential direction. It is difficult to assemble them, and there is a problem in that if they are pressed together, they may be damaged or difficult to assemble.

From such a viewpoint, the configuration shown in FIG. 4 having a straight abutment and the configuration shown in FIG. 5 having a stepped abutment are used.

[0007]

However, in the embodiment of FIG. 4, the piston 1 is provided with a piston ring 2A as a sealing member so that high-pressure fluid does not leak from the clearance t between the piston 1 and the cylinder 4. However, the piston ring 2A has an abutment clearance d0, and when the upper surface 2Ab side of the piston ring 2A is at a high pressure, the high-pressure fluid leaks from the area of d0 × t indicated by the lower oblique line. When the lower surface 2Aa is at a high pressure, d0 × t generated on the upper side
The high-pressure fluid leaks from the area of, causing loss.

In the case of the stepped abutment piston ring 2B shown in FIG. 5, the convex portion 2a and the end portion 2b formed with the concave portion to be fitted with the convex portion 2a are combined to form the lower surface 2a of the convex portion 2a. (FIG. 6) is seated in the piston groove of the piston, the degree of close contact of the space U1 between the upper surface 2c of the convex portion 2a and the upper surface 2d of the concave portion, and the side surface 2f of the convex portion 2a and the wall surface 2e of the concave portion. The amount of leakage is affected by the degree of close contact of the space U2 with the distance.

When the lower surface 2a 'is seated in the piston groove of the piston, the oil film from above the piston ring 2B leaks from the area of d2.times.t through the spaces U1 and U2. The joint of the part is accurately processed to reduce the amount of leakage by d0 × in the case of the straight joint.
It is smaller than the amount of leakage from the area of t and can be kept to a very small amount.

However, when the pressure in the upper piston chamber 5 and the lower piston chamber 6 alternately becomes high, as in a Stirling engine or a hydraulic cylinder, the upper surface 2b 'of the end 2b.
May be seated in the piston groove of the piston. In this case, even if the amount of leakage when the lower surface 2a 'is seated in the piston groove of the piston is minimized as described above, the same applies. However, it is not always possible to minimize the amount of leakage.

That is, for example, even when the thickness of the end portion 2b and the step between the upper surface 2c and the upper surface 2Bb of the mating convex portion 2a are large, there is no problem when the upper part is at high pressure. And the step between the upper surface 2c and the upper surface 2Bb of the convex portion 2a of the other party is large, and the lower portion is high pressure and 2b '
When the surface and the 2Bb surface are seated in the piston groove,
The degree of close contact between the upper surface 2c of the convex portion 2a and the upper surface 2d of the concave portion U1 becomes worse, the distance U1 increases, and the amount of leakage from the d1 × t area formed on the upper portion increases rather. Become. To prevent this, it is necessary to fit both ends without error, and a high level of technology is required.

In view of the above circumstances, the present invention provides a piston ring capable of minimizing leakage of high-pressure fluid when the piston ring is seated on either the upper surface or the lower surface of the piston groove. With the goal.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a piston ring which is mounted on a piston with both ends of the mouth engaged with each other and seals a pressurized fluid acting on one side of the piston.
One or a plurality of engaging concave portions and engaging convex portions are formed on the outer peripheral side of the end of the ring abutment to be engaged with the upper and lower surfaces, respectively, so that they can be fitted to each other. It is characterized in that a regulating surface for regulating in the radial direction is formed.

One of the ends of the abutment is cut in the thickness direction in a part from the outer peripheral surface side, and in the width direction, a part in the width direction is cut out from the upper and lower surfaces in the circumferential direction. Along with forming the engagement convex portion while leaving the portion, the other of the abutment ends is cut in the thickness direction from the inner peripheral surface side, and in the width direction, the entire width is cut off in the circumferential direction, and the remaining portion is cut off. It is also an effective means of the present invention that the engaging concave portion is formed by cutting off a central portion in the width direction, and the engaging convex portion and the engaging concave portion are formed to fit with each other.

FIG. 1 discloses a piston ring 10 in which both ends of a piston ring 10 are engaged at an abutment end 11 and mounted in a piston groove of the piston to seal a pressurized fluid acting on one side of the piston. Have been.

A protrusion 1 is provided on the outer peripheral side of the ring
a is formed between the upper surface of a and the lower surface of the protruding portion 10c, and is formed with an engaging convex portion 10b to be fitted into the engaging concave portion so that both can be fitted to each other. And a restricting surface for restricting the ring in the radial direction by contacting the inner surfaces with each other, that is, the engaging recess 1.
0i, the inner surfaces of the protrusions 10c and 10a (10
e, 10f), and wall surfaces (10g, 10h) extending vertically in the thickness direction from the engaging projections 10b.

Incidentally, as long as the engaging projection and the engaging recess are formed so as to abut against each other on the inner surfaces thereof to regulate the ring in the radial direction, the engaging projection 10b and the engaging The plurality of concave portions can be formed so as to be fittable with each other.

Since the present invention is constructed as described above, the engagement convex portion and the engagement concave portion are integrally connected, so that the piston ring is formed on the upper surface and the lower surface of the piston groove 1a (FIG. 3). Even when seated in any of the above, the contact state of the contact surface between the engagement convex portion and the plurality of protrusions of the engagement concave portion does not change, and the leakage of the high-pressure fluid increases the pressure. The degree of influence by the direction of application is extremely small, and it is possible to prevent a decrease in the efficiency of the device, and to ensure high efficiency.

Further, since the engaging projections and the engaging recesses have regulating surfaces for regulating the radial direction of the ring by contacting the inner surfaces thereof with each other, the displacement of the piston ring 10 in the width direction can be prevented at the abutment end. In the part, the ridge line between the end face of the engaging convex part or the engaging concave part and the outer surface protrudes outward from the outer peripheral surface and slides on the sliding surface of the cylinder to cause damage to each other. I can't.

Further, one end 11a of the abutment end face is cut in the thickness direction, a part from the outer peripheral face side is cut, and in the width direction, a part from the upper side face and the lower side face are cut off in the circumferential direction. The convex portion 10b is formed while leaving the portion, and the other 1
1b, a part from the inner peripheral surface side in the thickness direction, a front width in the width direction is cut off in the circumferential direction, and a remaining portion is cut out in the center in the width direction to form a concave portion 10i. The protrusion 10
By configuring so that b and the concave portion 10i are fitted to each other, leakage of the high-pressure fluid can be prevented with a minimum processing.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified.
It is only an illustrative example.

FIG. 1 is a configuration diagram showing an abutment configuration of a piston ring according to an embodiment of the present invention, and FIG.
It is II-II sectional drawing. The same members as those in the conventional example are denoted by the same reference numerals. The piston ring 10 in these figures is:
The two ends are engaged at the abutment end 11 and are mounted in the piston groove of the piston as shown in FIG. 3 to seal the pressurized fluid acting on one side of the piston.

In FIG. 1 and FIG.
Is a part from the outer peripheral surface side in the thickness direction,
In the width direction, a part from the upper side surface 10d 'and the lower side surface 10a' is cut off in the circumferential direction, and the convex portion 1 is left except for the central portion in the width direction.
0b is formed.

The other end 11b of the abutment end 11 is partially cut from the inner peripheral surface side in the thickness direction, the entire width is cut in the width direction in the circumferential direction, and the remaining portion is cut in the center in the width direction. By cutting off, a concave portion 10i is formed, and the convex portion 10b and the concave portion 10i are configured to be fitted to each other.

The engagement projection 10b at the abutment end 11a
Are two projections 10 forming the engagement recess 10i.
a and 10c, the upper surface of the protrusion 10a and the engagement protrusion 10b and the lower surface of the protrusion 10c and the engagement protrusion 10b are in close contact with each other.
b and intervals S1 and S2 between the protrusions 10c and 10a
Is almost zero, and the circumferential progress of the liquid film along the interval S1 or S2 is almost prevented.

In the operating state of the piston, the piston ring 10 is pressed in the cylinder inner wall pressing direction 12 in FIG. 3 by receiving the fluid pressure flowing from the gap between the piston groove 1a and the piston ring. Joint convex part 10b
10d forming wall surfaces 10g and 10h extending from
The distances S3 and S4 between the wall surface and the protruding portions 10c and 10a are also almost zero, and the liquid film is almost prevented from traveling in the circumferential direction along the distance S3 or S4.

In FIG. 1, the shape and dimensions of A and B are too small to reduce the strength and may cause breakage. / 3 or more is desirable. Also,
Regarding the shapes and dimensions of C, D and E, if any of them is too small, the strength is reduced and there is a possibility of breakage.
/ 3 (C + D + E) is desirable. In the case of the shape and size of F, if it is too long, it is difficult to fit when fitting, and the width of the piston ring (A + B) is preferable.

Next, the piston 1 of the piston ring 10
A method for assembling the components will be described. As shown in FIG. 1, the piston ring 10 is fitted with the engagement convex portion and the engagement concave portion at both ends of the joint, and
The piston groove 1a (FIG. 3) is inserted from above the piston 1. In this state, if the engaging convex portion 10b is slightly pushed in the circumferential direction, or if the engaging concave portion 11b is shifted as shown by a dashed line in FIG. 2, the 11b portion is moved from the outer peripheral side. The engagement convex portion 10b and the engagement concave portion 10i can be fitted by pressing toward the inner periphery.

When the piston 1 is mounted on the piston 1 and driven, as shown in FIG. 3, when the pressure in the J chamber is high, the piston ring 10 is seated on the wall surface 1c of the piston groove 1a. When the pressure in the K chamber is high, the piston ring 10 is seated on the wall surface 1d of the piston groove 1a. At this time, since the engagement convex portion and the engagement concave portion of the piston ring 10 are integrally fitted, the engagement of the two engagement portions is possible even if the piston ring 10 is seated on either wall surface of the piston groove 1a. The state does not change, so that the state of the distances D1 to D4 between the engagement surfaces does not change, and a good sealing state is maintained.

In the above-described embodiment, the fitting of the engaging protrusion and the engaging recess is described by clamping one engaging protrusion by one engaging recess. The present invention is not limited to this, and the engagement projections and the engagement recesses are not limited thereto, as long as the engagement projections and the engagement recesses are formed so as to abut each other on the inner surfaces thereof to regulate the ring in the radial direction. It goes without saying that the engagement recesses can be formed in a plurality and can be fitted to each other.

As described in detail above, the present embodiment is directed to a piston ring which is mounted with a piston in a state where both ends of the abutment are engaged and seals a pressurized fluid acting on one side of the piston. On the outer peripheral side, one or a plurality of engaging concave portions and engaging convex portions are formed so as to be engaged with each other on the upper and lower surfaces, so that they can be fitted to each other. It is configured so as to form a regulating surface.

With this configuration, the engagement convex portion and the engagement concave portion are integrally connected, so that the piston ring is connected to either the upper surface or the lower surface of the piston groove 1a (FIG. 3). Even when seated, the contact state of the contact surface between the engagement protrusion and the plurality of protrusions of the engagement recess does not change, and the leakage of the high-pressure fluid is in the direction in which high pressure is applied. The degree of influence is extremely small, and a reduction in the efficiency of the device can be prevented, and high efficiency can be ensured.

Further, since the engaging projections and the engaging recesses have regulating surfaces for regulating the radial direction of the ring by abutting on the inner surfaces thereof, the displacement of the piston ring 10 in the width direction is reduced to the abutment end. In the part, the ridge line between the end face of the engaging convex part or the engaging concave part and the outer surface protrudes outward from the outer peripheral surface and slides on the sliding surface of the cylinder to cause damage to each other. I can't.

Further, one of the end faces 11a, a part from the outer peripheral side in the thickness direction, and a part from the upper side and the lower side in the width direction are cut in the circumferential direction, and the center in the width direction is cut off. The convex portion 10b is formed while leaving the portion, and the other 1
1b, a part from the inner peripheral surface side in the thickness direction, a front width in the width direction is cut off in the circumferential direction, and a remaining portion is cut out in the center in the width direction to form a concave portion 10i. The protrusion 10
By configuring so that b and the concave portion 10i are fitted to each other, leakage of the high-pressure fluid can be prevented with a minimum processing.

[0035]

EXAMPLES Various types of piston rings were experimentally manufactured as follows, and comparative experiments were conducted. (1) Shape of piston ring No step: mode shown in FIG. 4, 2 step: mode shown in FIG. 5, 3
Steps: As shown in FIG. 1, Four steps: Two engaging projections and two engaging recesses of FIG. 1 were formed, and two projections were sandwiched by two recesses. (2) The distance d between both end faces of the piston ring is the same.

Experimental Results (A) When there is no step, the leakage amount of the fluid does not change even if the direction of the high-pressure fluid is reversed, but the leakage amount of the fluid is large. (B) In the case of two stages, the amount of fluid leakage is lower than in the case of no stage, but when the direction of the high-pressure fluid is reversed, the amount of fluid leakage is large as in the case of no stage. (C) In the case of three stages and four stages, the leakage amount of the fluid is lower than in the case of no stage, regardless of the direction of the high-pressure fluid. In the case of three stages and four stages, the leakage amount of the fluid does not change.

From these data, it can be seen that three or more stages provide good results with little fluid leakage. Therefore, regardless of the number of steps, it is determined that the abutting state of the both end faces of the piston ring has a sealing property and that the sealing property does not change regardless of the seating state of the piston ring on the piston groove wall surface. Is done.

[0038]

As described above, according to the present invention, even when either the upper chamber or the lower chamber of the piston has a high pressure and the piston ring is seated on either the upper surface or the lower surface of the piston groove, It is possible to provide a piston ring capable of minimizing the leakage of the high-pressure fluid from the joint, reducing the loss, and securing a highly efficient device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a piston ring according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an explanatory diagram of an operation of a piston ring.

FIG. 4 is a configuration diagram of a straight engagement piston ring according to a conventional example.

FIG. 5 is a configuration diagram of a stepped piston ring according to a conventional example.

FIG. 6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a mounting state diagram of a piston ring.

[Explanation of symbols]

 Reference Signs List 1 piston 4 cylinder 5 piston upper chamber 6 piston lower chamber 10 piston ring 11 engaging part (11a, 11b)

Claims (2)

[Claims] Claims: 1. A piston ring which is mounted with a piston in a state in which both ends of an abutment are engaged and seals a pressurized fluid acting on one side of the piston, wherein the piston ring engages an outer peripheral side of a ring abutment end on both upper and lower surfaces. Alternatively, a plurality of engaging concave portions and engaging convex portions are formed so as to be fittable with each other, and a regulating surface is formed on an inner surface of the engaging concave portion and the engaging convex portion to regulate the ring in the radial direction. piston ring. 2. One end of the abutment is cut off in the thickness direction in a part from the outer peripheral surface side, in the width direction partly in the upper side and the lower side in the circumferential direction, and cut in the center in the width direction. While forming the engagement convex portion leaving the portion, the other of the abutting end portion, in the thickness direction, a part from the inner peripheral surface side,
In the width direction, the entire width is cut in the circumferential direction, and the remaining portion is cut in the center in the width direction to form an engagement recess. The engagement protrusion and the engagement recess are fitted and formed with each other. The piston ring according to claim 1, wherein: