JPH09159023A - Piston ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a sealing property toward the upper face or the lower face of a ring groove by arranging an elastic ring, which is provided with a vertical width larger than that of the ring groove and is inserted into the ring groove, between a ring type spring member and a piston ring. SOLUTION: While a piston ring 1 is inserted into a ring groove 3, a ring type coil expander 5 pressing the piston ring 1 outward is arranged, and an elastic ring 6 formed of an elastic body such as rubber is arranged between the piston ring 1 and the coil expander 5. As the elastic ring 6 is provided with a vertical width larger than that of the ring groove 3, the elastic ring 6 is brought into tight contact with the upper face 3a and the lower face 3b of the ring groove 3 when the elastic ring 6 is inserted in the ring grove 3, so that a sealing property within the elastic groove 6 can be secured in the ring groove 3. In this way, a sealing property between the piston ring and a cylinder bore can be secured.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a piston ring.

[0002]

2. Description of the Related Art It is known to use a resin piston ring having no abutment for the purpose of improving the sealing property. In Japanese Patent Laid-Open No. 57-148036, such a resin piston ring having a small self-tension is used, and a ring-shaped spring for pressing the resin piston ring radially outward is arranged in the ring groove. It is disclosed.

[0003]

In the above-mentioned prior art, the sealability between the piston ring and the cylinder bore, that is, the sealability along the cylinder bore is certainly improved. However, this resin piston ring has a problem that the sealing performance with respect to the upper surface or the lower surface of the ring groove is not guaranteed, and gas in the combustion chamber leaks to the crankcase along the ring groove.

Therefore, it is an object of the present invention to ensure a high sealability along the cylinder bore and the ring groove in a resin piston ring that is pressed outward by a ring-shaped spring member.

[0005]

A piston ring according to the present invention according to claim 1 is a resin-made piston ring inserted into a ring groove and pressed outward by a ring-shaped spring member. An elastic ring having a vertical width larger than the vertical width of the ring groove and inserted into the ring groove is interposed between the elastic ring and the piston ring. Are abutted against each other, and an uneven fitting portion is formed between the abutting surfaces.

In this piston ring, since the elastic ring has a vertical width larger than the vertical width of the ring groove, when the elastic ring is inserted into the ring groove, the piston ring is in close contact with the upper surface and the lower surface of the ring groove, and the ring-shaped spring member is made of this elastic material. The resin piston ring is pressed outward through the ring, the elastic ring and the resin piston ring abut against each other by their respective contact surfaces, and there is a concave-convex fitting portion between these contact surfaces. Since the elastic ring is formed, the elastic ring is unlikely to be deformed even when a force in the piston axial direction is applied, and the elastic ring is kept in close contact with the ring groove and kept in contact with the piston ring.

The piston ring according to a second aspect of the present invention is a resin-made piston ring inserted in a ring groove and pressed outward by a ring-shaped spring member. An elastic ring that has a vertical width larger than the vertical width of the ring groove and is inserted into the ring groove, and the elastic ring and the piston ring contact each other by their contact surfaces, At least one of the upper part and the lower part of the elastic ring extends to the inside from the center of the cross section of the ring-shaped spring member.

In this piston ring, since the elastic ring has a vertical width larger than the vertical width of the ring groove, the piston ring comes into close contact with the upper surface and the lower surface of the ring groove when the ring is inserted into the ring groove, and the ring-shaped spring member has the elasticity. The resin piston ring is pressed outward through the ring, the elastic ring and the back surface of the resin piston ring contact each other by their respective contact surfaces, and at least one of the upper and lower portions of the elastic ring is ring-shaped. Since the spring member extends to the inside from the center of the cross section, even if a force is applied to the elastic ring in the direction of the piston axis, the elastic ring is unlikely to be deformed to rotate about the ring-shaped spring member. The contact with the piston ring and the contact with the piston ring are maintained.

A piston ring according to a third aspect of the present invention is a resin-made piston ring inserted into a ring groove and pressed outward by a ring-shaped spring member. An elastic ring having a vertical width larger than the vertical width of the ring groove and inserted into the ring groove is interposed between the elastic ring and the piston ring. An uneven fitting portion is provided between at least one of the upper portion and the lower portion of the ring and the ring groove.

In this piston ring, since the elastic ring has a vertical width larger than the vertical width of the ring groove, the piston ring comes into close contact with the upper and lower surfaces of the ring groove when the ring is inserted into the ring groove, and the ring-shaped spring member has the elasticity. The resin piston ring is pressed outward through the ring, and the elastic ring and the back surface of the resin piston ring contact each other by their respective contact surfaces, and at least one of the upper and lower parts of the elastic ring and the ring groove. Since a concave-convex fitting portion is provided between the elastic ring and the elastic ring, deformation is unlikely to occur even when a force is applied to the elastic ring in the piston axial direction, and the elastic ring is kept in close contact with the ring groove and is kept in contact with the piston ring. To be done.

A piston ring according to a fourth aspect of the present invention is a resin-made piston ring inserted into a ring groove and pressed outward by a ring-shaped spring member, wherein the ring-shaped spring member and the piston ring. An elastic ring that has a vertical width larger than the vertical width of the ring groove and is inserted into the ring groove, and the elastic ring and the piston ring contact each other by their contact surfaces, The ring-shaped spring member has a non-circular cross section, and the elastic ring is formed with a contact surface that comes into surface contact with the ring-shaped spring member.

In this piston ring, since the elastic ring has a vertical width larger than the vertical width of the ring groove, when the piston ring is inserted into the ring groove, the ring closely contacts the upper surface and the lower surface of the ring groove, and the ring-shaped spring member makes the elastic ring. The resin-made piston ring is pressed outward through the ring, the elastic ring and the back surface of the resin-made piston ring contact each other by their contact surfaces, and the ring-shaped spring member has a non-circular cross section. Since the elastic ring has a contact surface that comes into surface contact with the ring-shaped spring member, even if a force is applied to the elastic ring in the direction of the piston axis, the elastic ring is unlikely to be deformed such that it rotates about the ring-shaped spring member. The close contact of the elastic ring with the ring groove and the contact with the piston ring are maintained.

According to a fifth aspect of the present invention, there is provided a piston ring made of resin, which is inserted into a ring groove and is pressed outward by a ring-shaped spring member. An elastic ring that has a vertical width larger than the vertical width of the ring groove and is inserted into the ring groove, and the elastic ring and the piston ring contact each other by their contact surfaces, A plurality of the ring-shaped spring members are provided, an inserted elastic ring is interposed, the elastic ring and the piston ring contact each other by respective contact surfaces, and a plurality of the ring-shaped spring members are provided,
At least one of the ring-shaped spring members is positioned below the center plane of the vertical width of the ring groove.

In this piston ring, since the elastic ring has a vertical width larger than the vertical width of the ring groove, the piston ring comes into close contact with the upper and lower surfaces of the ring groove when the ring is inserted into the ring groove, and the ring-shaped spring member has the elasticity. The resin-made piston ring is pressed outward through the ring, the elastic ring and the back surface of the resin-made piston ring are brought into contact with each other by their respective contact surfaces, and a plurality of ring-shaped spring members are provided. Since the ring-shaped spring member is located below the center plane of the vertical width of the ring groove, even if a force in the piston axial direction acts on the elastic ring, the ring-shaped spring member will rotate about any ring-shaped spring member. Deformation is unlikely to occur, and the elastic ring is kept in close contact with the ring groove and kept in contact with the piston ring.

[0015]

1 is a sectional view showing a first embodiment of a piston ring according to the present invention. In the figure, 1 is a polymer polymer of PTFE (PTFE).
It is a piston ring molded from resin such as. Reference numeral 2 is a piston, 3 is a ring groove formed in the piston 2, and 4 is a cylinder bore.

In the ring groove 3, the piston ring 1 is inserted, and a ring-shaped coil expander 5 for pressing the piston ring 1 outward is arranged. Further, an elastic ring 6 formed of an elastic body such as rubber is interposed between the piston ring 1 and the coil expander 5. The elastic ring 6 has a vertical width larger than the vertical width of the ring groove 3. Thereby, when the elastic ring 6 is inserted into the ring groove 3, the upper surface 3a and the lower surface 3b of the ring groove 3 come into close contact with each other, so that the sealability of the ring groove 3 inside the elastic ring 6 is ensured. The elastic ring 6 is preferably provided with a taper as shown in order to facilitate insertion into the ring groove 3.

The coil expander 5 pushes the piston ring 1 outward through the elastic ring 6. As a result, the piston ring 1 is in close contact with the cylinder bore 4, and the sealing property between the piston ring 1 and the cylinder bore 4 is ensured. Since the piston ring 1 is made of resin and has a certain degree of elasticity, it can be inserted into the ring groove 3 without providing an abutment, and the sealing property along the cylinder bore 4 is considerably high. Can be

By the above-mentioned pressing by the coil expander 5, the elastic ring 6 and the piston ring 1 abut against each other by their abutting surfaces, and the sealing property between the elastic ring 6 and the piston ring 1 is secured. . Thereby, high sealing performance along the cylinder bore 4 and high sealing performance along the ring groove 3 are provided, and gas leakage from the combustion chamber to the crankcase is prevented, and
The engine oil adhering to the cylinder bore 4 can be scraped off well, and the consumption of the engine oil can be minimized.

In the present embodiment, the coil expander 5 balances the pressing force between the upper and lower portions of the elastic ring 6 and the upper and lower portions of the piston ring 1 to prevent contact or the like and to achieve the above-mentioned sealing performance. For the sake of goodness, the ring groove 3 is substantially located on the center plane F of the vertical width. The coil expander 5 has a substantially circular cross section. The elastic ring 6 is the coil expander 5
It has a contact surface 5a having a substantially semicircular cross-sectional shape that comes into surface contact with, and thereby the position of the coil expander 5 can be stabilized.

In actual use, the gas pressure in the combustion chamber acts to push down the elastic ring 6, and the sliding of the piston ring 1 and the cylinder bore 4 generates a frictional force pushing down the elastic ring 6. To do. As in this embodiment, the coil expander 5 has a substantially circular cross-sectional shape and is located on the center plane F of the vertical width of the ring groove 3,
When the contact surface 5a of the elastic ring 6 has a substantially semicircular cross-sectional shape, when a force that pushes down the elastic ring 6 acts, the elastic ring 6 causes the elastic ring 6 to have a cross-sectional center C of the coil expander 5.
There is a possibility of causing deformation such as rotating around. When such deformation occurs, the sealability between the elastic ring 6 and the piston ring 1 and the ring groove 3 is impaired.

In this embodiment, since the concavo-convex fitting portions 7 are formed on the contact surfaces of the elastic ring 6 and the piston ring 1, the above-mentioned elastic ring 6 is actually used. Deformation is securely prevented and the elastic ring 6
It is possible to maintain high sealability between the piston ring 1 and the ring groove 3. The concave-convex fitting portion 7 described above is
Contrary to the illustration, a concave portion may be formed on the contact surface on the piston ring 1 side and a convex portion may be formed on the contact surface on the elastic ring 6 side. Of course, it is also possible to provide a plurality of recesses and protrusions that fit with each other instead of a pair of recessed and projected fitting portions.

FIG. 2 is a sectional view showing a second embodiment of the piston ring according to the present invention. Only the differences from the first embodiment will be described below. In the present embodiment, no concavo-convex fitting portion is provided on the contact surfaces of the piston ring 100 and the elastic ring 106. But,
Contact surface 1 of elastic ring 106 with coil expander 5
06a has a substantially U-shaped cross-sectional shape, and the upper and lower portions of the elastic ring 106 extend at least inside the center C of the cross section of the coil expander 5.

Further, a convex portion that fits into the concave portion formed in the ring groove 3 is formed on the upper portion of the elastic ring 106, that is, an uneven fitting is provided between the elastic ring 106 and the ring groove 3. A joint 8 is formed. By configuring the elastic ring 106 in this way, even when a force that pushes down the elastic ring 106 is applied during use, the above-described extension of the upper and lower portions of the elastic ring 106 and the concave-convex fitting portion 8 are caused. In any case, the elastic ring 106 is surely prevented from being deformed so as to rotate around the center of the cross section of the coil expander 5, and like the first embodiment, the elastic ring 106, the piston ring 100, and the ring groove 3 are formed. It is possible to maintain a high sealability between and.

In the present embodiment, by extending at least one of the upper portion and the lower portion of the elastic ring 106 inward from the center C of the cross section of the coil expander 5, the above-described deformation of the elastic ring 106 is prevented. It can be sufficiently prevented. In addition, the concave and convex fitting portion 8 between the elastic ring 106 and the ring groove 3 is sufficient for the elastic ring 1.
It is possible to prevent the above-mentioned deformation of 06.

FIG. 3 is a sectional view showing a third embodiment of the piston ring according to the present invention. Only the differences from the second embodiment will be described below. In this embodiment, the coil expander 105 has a substantially elliptical sectional shape. Further, the contact surface 206a of the elastic ring 206 is formed so as to come into sufficient contact with the coil expander 105. In the piston ring configured as described above, even when a force that pushes down the elastic ring 206 is applied during use, the elastic ring 206 is not circular because the cross-sectional shape of the coil expander 105 is non-circular.
It is difficult to deform so as to rotate around the center C of the cross section of 05, and it is possible to maintain high sealing performance between the elastic ring 106 and the piston ring 100 and the ring groove 3.

FIG. 4 is a sectional view showing a fourth embodiment of the piston ring according to the present invention. Only the differences from the third embodiment will be described below. In the present embodiment, the ring-shaped spring member that presses the piston ring 100 outward is not the coil expander but the ring-shaped leaf spring 205 having a vertically long rectangular cross-sectional shape. Elastic ring 3
The contact surface 306a of 06 is formed so as to sufficiently contact the ring-shaped leaf spring 205. The piston ring configured as described above is used when the elastic ring 3 is used.
Even if the force to push down 06 is applied, the ring-shaped leaf spring 20
Since the cross-sectional shape of 5 is non-circular, the elastic ring 306
Does not easily deform so as to rotate around the center C of the cross section of the ring-shaped leaf spring 205, and the elastic ring 306
It is possible to maintain a high sealability between the piston ring 100 and the ring groove 3.

FIG. 5 is a sectional view showing a fifth embodiment of the piston ring according to the present invention. Only the differences from the third embodiment will be described below. In the present embodiment, the ring-shaped spring member that presses the piston ring 100 outward is not the single coil expander but the ring groove 3
The two ring-shaped wire springs 305 are vertically arranged so as to be substantially symmetrical with respect to the center plane F of the upper and lower widths. The ring-shaped wire spring 305 has a substantially circular cross-sectional shape, and the contact surface 406a of the elastic ring 406 is formed so as to sufficiently contact these ring-shaped wire springs 305. In the piston ring configured as described above, the pressing force is balanced between the upper and lower portions of the elastic ring 406 and the upper and lower portions of the piston ring 100 by the two ring-shaped wire springs 305, as in the above-described embodiment. It is supposed to do. In addition, even when a force that pushes down the elastic ring 406 is applied during use, the elastic ring 406 is positioned because the one ring-shaped wire spring 305 is located below the center plane F of the vertical width of the ring groove 3. Is difficult to be deformed so as to rotate about both the center of the cross section of the ring-shaped wire spring 305 and the center of the cross section of the other ring-shaped spring 305.
A high sealability between the piston ring 100 and the ring groove 3 can be maintained.

In this embodiment, the ring-shaped wire rod spring 3
The number of 05 is not limited to two, and if a plurality of 05 are positioned below the center plane of the vertical width of the ring groove, the same effect can be obtained. Of course, a plurality of coil expanders may be provided instead of the ring-shaped wire spring.

[0029]

As described above, according to the piston ring of the present invention as set forth in claim 1, since the elastic ring has the vertical width larger than the vertical width of the ring groove, the ring is inserted into the ring groove. The ring-shaped spring member presses the resin-made piston ring outward through the elastic ring by closely contacting the upper surface and the lower surface of the groove and ensuring the sealing property inside the elastic ring in the ring groove. The sealability between the cylinder ring and the cylinder bore is ensured, and the elastic ring and the resin piston ring are in contact with each other by their contact surfaces to ensure the sealability therebetween. Further, since the concave-convex fitting portion is formed between the contact surface of the elastic ring and the contact surface of the resin piston ring, the elastic ring is not deformed even when a force in the piston axial direction is applied. It is difficult to occur, and the above three sealing properties can be maintained.

Further, according to the piston ring of the present invention as defined in claim 2, as in the above, three sealing properties are ensured, and at least one of the upper part and the lower part of the elastic ring is the center of the cross section of the ring-shaped spring member. Since it extends to the inner side, even if a force in the axial direction of the piston acts on the elastic ring, deformation such as rotation around the ring-shaped spring member does not occur easily, and maintain the above-mentioned three sealing properties. You can

Further, according to the piston ring of the present invention as defined in claim 3, as in the above, three sealing properties are ensured, and further, between at least one of the upper and lower portions of the elastic ring and the ring groove. Since the concavo-convex fitting portion is provided, the elastic ring is less likely to be deformed even when a force in the piston axial direction is applied, and the above three sealing properties can be maintained.

Further, according to the piston ring of the present invention as defined in claim 4, as in the above, three sealing properties are ensured, and further, the ring-shaped spring member has a non-circular cross section,
Since the elastic ring has a contact surface that comes into surface contact with the ring-shaped spring member, even if a force is applied to the elastic ring in the direction of the piston axis, the elastic ring is unlikely to be deformed such that it rotates about the ring-shaped spring member. The three sealing properties described above can be maintained.

Further, according to the piston ring of the present invention as defined in claim 5, as described above, three sealing properties are secured, and further, a plurality of ring-shaped spring members are provided, and at least one ring-shaped spring member is provided. Since it is located below the center plane of the vertical width of the ring groove, even if a force in the piston axial direction acts on the elastic ring, deformation such as rotation around any ring-shaped spring member does not easily occur, The above three sealing properties can be maintained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a piston ring according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the piston ring according to the present invention.

FIG. 3 is a sectional view showing a third embodiment of the piston ring according to the present invention.

FIG. 4 is a sectional view showing a fourth embodiment of the piston ring according to the present invention.

FIG. 5 is a sectional view showing a fifth embodiment of the piston ring according to the present invention.

[Explanation of symbols]

 1, 100 ... Piston ring 2 ... Piston 3 ... Ring groove 4 ... Cylinder bore 5, 105 ... Coil expander 6, 106, 206, 306, 406 ... Elastic ring 7 ... Uneven fitting part 8 ... Uneven fitting part

Claims (5)

[Claims] 1. A resin-made piston ring inserted into a ring groove and pressed outward by a ring-shaped spring member, wherein the resin-made piston ring is larger than the vertical width of the ring groove between the ring-shaped spring member and the piston ring. An elastic ring having a vertical width and inserted into the ring groove is interposed, and the elastic ring and the piston ring abut on each other by respective abutting surfaces, and a concave-convex fitting portion is provided between the abutting surfaces. A piston ring characterized by being formed. 2. A resin piston ring, which is inserted into a ring groove and is pressed outward by a ring-shaped spring member, having a width larger than a vertical width of the ring groove between the ring-shaped spring member and the piston ring. An elastic ring having a vertical width and inserted into the ring groove is interposed, the elastic ring and the piston ring are in contact with each other by respective contact surfaces, and at least one of an upper portion and a lower portion of the elastic ring is the ring. A piston ring, wherein the piston ring extends inward from the center of the cross section of the spring member. 3. A resin piston ring inserted into a ring groove and pressed outward by a ring-shaped spring member, wherein a vertical width larger than the vertical width of the ring groove is provided between the spring member and the piston ring. An elastic ring to be inserted into the ring groove is interposed, the elastic ring and the piston ring abut against each other by respective abutting surfaces, and at least one of an upper portion and a lower portion of the elastic ring and the ring groove A piston ring characterized in that an uneven fitting portion is provided between them. 4. A resin piston ring which is inserted into a ring groove and is pressed outward by a ring-shaped spring member, wherein the resin-made piston ring is larger than the vertical width of the ring groove between the ring-shaped spring member and the piston ring. An elastic ring having a vertical width and inserted into the ring groove is interposed, the elastic ring and the piston ring contact each other by respective contact surfaces, and the ring-shaped spring member has a non-circular cross section, A piston ring, wherein the elastic ring is formed with a contact surface that comes into surface contact with the ring-shaped spring member. 5. A resin piston ring inserted into a ring groove and pressed outward by a ring-shaped spring member, wherein the resin-made piston ring is larger than the vertical width of the ring groove between the ring-shaped spring member and the piston ring. An elastic ring having a vertical width and inserted into the ring groove is interposed, the elastic ring and the piston ring are in contact with each other by respective contact surfaces, and a plurality of the ring-shaped spring members are provided, and at least one The piston ring, wherein the ring-shaped spring member is located below the center plane of the vertical width of the ring groove.