JP4859686B2 - Combination of oil ring with coil expander and piston - Google Patents

Description

The present invention relates to a combination of an oil ring with a coil expander and a piston used in an internal combustion engine.

  A compression ring that mainly performs gas sealing and an oil control ring that controls lubricating oil in the cylinder bore are mounted on the piston of the internal combustion engine. In addition to the gas seal, the compression ring has a sliding surface tapered ring with oil control function, and is used as a second ring. The oil control ring has independent upper and lower rails, and a three-piece type with a spacer expander that projects the outer circumference of the rail to the cylinder bore surface and the rail side surfaces to the upper and lower surfaces of the ring groove. A two-piece type that has a structure and projects a rail to the outer periphery with a coil expander is mainly used.

  However, the second ring may have poor sealing performance on the upper surface of the ring groove. On the other hand, in the oil control ring, when the upper and lower rails are independent types, the sealing properties of the upper and lower surfaces of the ring groove are good, but the stick resistance may be poor. In addition, when the upper and lower rails are of an integrated type, the sealing performance of the upper and lower surfaces of the ring groove may be poor.

As a means for improving the sealing performance of the upper surface of the ring groove when the upper and lower rails are of the integrated type, Patent Document 1 proposes a structure in which the back surface of the oil ring body is inclined and the inclined surface is pressed by a pressure element. Yes. Patent Documents 2 and 3 propose a structure in which the back surface of the oil ring body is inclined and the inclined surface is pressed by a coil expander.
Japanese Patent Publication No. 48-12006 JP 2002-30001 A JP 2002-30002 A

  However, in the technique of Patent Document 1, the inclined back surface of the oil ring main body and the inclined surface of the pressure element are displaced vertically from each other, or the contact position between the inclined back surface of the oil ring main body and the inclined surface of the pressure element is not constant. For this reason, the tension may change, and adverse effects such as a decrease in oil control performance and an increase in frictional force may occur. Moreover, since the coil expander can move the back surface of the oil ring body in the vertical direction by the inertial force and the behavior of the piston, the deflection amount of the coil expander changes and the tension changes. Therefore, the same adverse effect as in Patent Document 1 may occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a combination of an oil ring with a coil expander and a piston that can appropriately maintain the force of projecting the oil ring to the outer peripheral side, and that can improve the sealing performance on the upper surface side of the ring groove of the piston. There is.

In order to solve the above problems, the present invention employs the following means. That is,
The present invention has a biasing means for pressing the back surface of a coil expander of an oil ring with a coil expander in which a coil expander is arranged on the inner peripheral side of the oil ring from an obliquely lower side, and the biasing means is a ring of a piston. A combination of an oil ring with a coil expander and a piston, which is inserted into a recess provided in the groove bottom.

  As the biasing means, a leaf spring having a plurality of humps spaced apart in the circumferential direction is in contact with the bottom surface of the recess provided in the ring groove bottom, an axial wave type expander, a radial wave A type expander or coil expander is used.

According to the present invention, the oil ring with the coil expander is pushed obliquely upward by the biasing means disposed on the back surface of the oil ring with the coil expander , so that the oil ring is brought into contact with the upper surface of the ring groove of the piston. Thus, the sealing performance on the upper surface side of the ring groove of the piston can be improved. In addition, since the vertical movement of the urging means can be restricted by a recess provided at the bottom of the ring groove of the piston, the vertical movement in the ring groove of the urging means can be reduced, and the force to project the oil ring to the outer peripheral side The sealability on the upper surface side of the ring groove can be improved while keeping it appropriate.

  In particular, when the biasing means is the above-described leaf spring, the piston slap can be suppressed in addition to the improvement of the sealing performance on the ring groove upper surface side.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  The combination oil ring 10 includes a steel oil ring 11 and a coil expander 12 and is mounted in the ring groove 3 of the piston 2. The oil ring 11 is a ring having a substantially I-shaped cross section, and includes a pair of upper and lower rails 13 and 14 extending in the circumferential direction and a web 15 extending in the circumferential direction and connecting the pair of rails 13 and 14. The oil scraped off from the inner peripheral surface of the cylinder 7 by the lower rail 14 is dropped into the oil pan as it is, and the oil scraped off by the upper rail 13 is formed on the web 15 at intervals in the circumferential direction. It moves to the inner peripheral side of the oil ring 11 through the window holes 16 and is dropped into the oil pan through an oil passage (not shown) formed in the piston 2.

  An expander mounting groove 17 having a circular arc cross section is formed on the inner peripheral side of the oil ring 11, and the coil expander 12 is mounted in the groove 17. The coil expander 12 is a ring formed by winding a wire in a coil shape, and presses and urges the oil ring 11 outward in the radial direction.

  A leaf spring 5 is disposed on the back surface of the combination oil ring 10. The leaf spring 5 is a leaf spring obtained by forming a plate material into a polygonal shape, and is inserted into a recess 6 formed in the lower portion of the bottom surface 3 a of the ring groove 3. The recess 6 is formed at a predetermined height from the position of the lower surface 3b of the ring groove 3 and at a predetermined depth from the position of the bottom surface 3a.

  Accordingly, the leaf spring 5 is disposed on the ring groove lower surface 3b with the inner periphery contacting the bottom surface 6a of the recess 6 and the outer periphery protruding from the recess 6, and the upper end of the outer periphery at the vertex position of the polygon is combined. The combined oil ring 10 is pressed obliquely upward on the outer peripheral side by contacting the lower part of the oil ring 10 on the back side of the coil expander 12 and pressing the coil expander 12 outward. As a result, the combination oil ring 10 has the outer peripheral sliding surface of the oil ring 11 pressed against the inner peripheral surface of the cylinder 7, and the upper surface of the upper rail 13 of the oil ring 11 is in contact with the ring groove upper surface 3c. 2 can improve the sealing performance on the side of the ring groove upper surface 3c. Further, since the vertical movement of the leaf spring 5 can be restricted by the recess 6 provided in the bottom surface 3a of the ring groove 3, the vertical movement of the leaf spring 5 in the ring groove 3 can be reduced, and the oil ring 11 is moved to the outer peripheral side. The sealing property on the ring groove upper surface 3c side can be improved while keeping the overhanging force properly.

3 to 4 show another embodiment of the present invention, in which the biasing means is an axial wave expander.

  The combination oil ring 10 is the same as that described in the above embodiment.

  An axial wave expander 18 is disposed on the back surface of the combination oil ring 10. The axial corrugated expander 18 is composed of horizontal upper pieces 19 and lower pieces 20 that are spaced apart in the axial direction and arranged alternately in the circumferential direction, and a connecting piece 21 that connects these adjacent ends. Is formed. The expander 18 is formed by forming a plate material into a wave shape in the plate thickness direction and further forming it into an annular shape. The axial wave type expander 18 is inserted into a recess 6 formed in the lower part of the bottom surface 3 a of the ring groove 3. The recess 6 is formed at a predetermined height from the position of the lower surface 3b of the ring groove 3 and at a predetermined depth from the position of the bottom surface 3a.

  Therefore, the axial wave type expander 18 is disposed on the ring groove lower surface 3 b with the outer periphery protruding from the recess 6, and the upper end of the outer periphery is an oblique lower portion on the back side of the coil expander 12 in the combined oil ring 10. The combined oil ring 10 is pressed obliquely upward on the outer peripheral side by pressing the coil expander 12 outwardly in contact with the. As a result, the combination oil ring 10 has the outer peripheral sliding surface of the oil ring 11 pressed against the inner peripheral surface of the cylinder 7, and the upper surface of the upper rail 13 of the oil ring 11 is in contact with the ring groove upper surface 3c. 2 can improve the sealing performance on the side of the ring groove upper surface 3c. Further, since the vertical wave movement of the axial wave type expander 18 can be restricted by the recess 6 provided in the bottom surface 3a of the ring groove 3, the vertical movement of the axial wave type expander 18 in the ring groove 3 can be reduced. Further, it is possible to improve the sealing performance on the ring groove upper surface 3c side while appropriately maintaining the force of projecting the oil ring 11 to the outer peripheral side.

FIG. 5 shows still another embodiment of the present invention, which is an example in which the structure of the axial wave type expander shown in FIG. 4 is slightly changed.

  The axial wave type expander 18 in the present embodiment is formed in a tapered shape in which an outer peripheral surface 22 is inclined downward toward the outer peripheral side, and this tapered outer peripheral surface 22 is a combined oil ring. 10, the combined oil ring 10 is pressed obliquely upward on the outer peripheral side by contacting the coil lower portion 12 on the back side of the coil expander 12 and pressing the coil expander 12 outward.

6 to 7 show still another embodiment of the present invention, in which the biasing means is a radial wave type expander.

  The combination oil ring 10 is the same as that described in the above embodiment.

  A radial wave type expander 23 is arranged on the back surface of the combination oil ring 10. The radial corrugated expander 23 is composed of vertical outer pieces 24 and inner pieces 25 that are spaced apart in the radial direction and alternately arranged in the circumferential direction, and a connecting piece 26 that connects these adjacent ends. Is formed. The expander 23 is formed by forming a plate material into a wave shape in the plate thickness direction and further forming it into an annular shape. The radial wave type expander 23 is inserted into a recess 6 formed in the lower part of the bottom surface 3 a of the ring groove 3. The recess 6 is formed at a predetermined height from the position of the lower surface 3b of the ring groove 3 and at a predetermined depth from the position of the bottom surface 3a.

  Accordingly, the radial corrugated expander 23 is arranged on the ring groove lower surface 3 b with the outer periphery protruding from the recess 6, and the upper end of the outer periphery is an oblique lower portion on the back side of the coil expander 12 in the combined oil ring 10. The combined oil ring 10 is pressed obliquely upward on the outer peripheral side by pressing the coil expander 12 outwardly in contact with the. As a result, the combination oil ring 10 has the outer peripheral sliding surface of the oil ring 11 pressed against the inner peripheral surface of the cylinder 7, and the upper surface of the upper rail 13 of the oil ring 11 is in contact with the ring groove upper surface 3c. 2 can improve the sealing performance on the side of the ring groove upper surface 3c. Further, since the vertical wave movement of the radial wave type expander 23 can be restricted by the recess 6 provided in the bottom surface 3a of the ring groove 3, the vertical movement of the radial wave type expander 23 in the ring groove 3 can be reduced. Further, it is possible to improve the sealing performance on the ring groove upper surface 3c side while appropriately maintaining the force of projecting the oil ring 11 to the outer peripheral side.

8 to 9 show still another embodiment of the present invention, in which the biasing means is a coil expander.

  The combination oil ring 10 is the same as that described in the above embodiment.

  A coil expander 27 is disposed on the back surface of the combination oil ring 10. The coil expander 27 is formed by winding a wire in a coil shape into a ring shape. The coil expander 27 is inserted into a recess 6 formed in the lower part of the bottom surface 3 a of the ring groove 3. The recess 6 is formed at a predetermined height from the position of the lower surface 3b of the ring groove 3 and at a predetermined depth from the position of the bottom surface 3a.

  Therefore, the coil expander 27 is arranged on the ring groove lower surface 3 b with the outer periphery protruding from the recess 6, and the outer periphery oblique upper part contacts the oblique lower part on the back side of the coil expander 12 in the combined oil ring 10. By pressing the coil expander 12 outward, the combined oil ring 10 is pressed obliquely upward on the outer peripheral side. As a result, the combination oil ring 10 has the outer peripheral sliding surface of the oil ring 11 pressed against the inner peripheral surface of the cylinder 7, and the upper surface of the upper rail 13 of the oil ring 11 is in contact with the ring groove upper surface 3c. 2 can improve the sealing performance on the side of the ring groove upper surface 3c. In addition, since the vertical movement of the coil expander 27 can be restricted by the recess 6 provided in the bottom surface 3a of the ring groove 3, the vertical movement of the coil expander 27 in the ring groove 3 can be reduced, and the oil ring 11 can be The sealing performance on the ring groove upper surface 3c side can be improved while keeping the force protruding to the side appropriately.

FIG. 10 shows still another embodiment of the present invention, which differs from that shown in FIGS. 8 to 9 only in the shape of the ring groove of the piston. That is, in the present embodiment, the ring groove bottom surface 3a and the recess bottom surface 6a of the piston 2 are formed along the arc surfaces of the coil expanders 12 and 27, respectively.

It is a longitudinal cross-sectional view which shows one Embodiment of this invention. Is a cross-sectional plan view showing the roots if plate. It is a longitudinal cross-sectional view which shows another embodiment of this invention. It is a perspective view which shows a part of axial wave type | mold expander. It is a longitudinal cross-sectional view which shows another embodiment of this invention. It is a longitudinal cross-sectional view which shows another embodiment of this invention. It is a top view which shows a radial direction wave type | mold expander. It is a longitudinal cross-sectional view which shows another embodiment of this invention. It is a top view which shows a coil expander. It is a longitudinal cross-sectional view which shows another embodiment of this invention.

  2. Piston, 3. Ring ring groove, 3a, Ring groove bottom surface, 3b, Ring groove lower surface, 3c, Ring groove upper surface, 5, Plate spring, 6, Recess, 6a, Recess bottom surface, 7 · · Cylinder, 10 · · Combination oil ring, 11 · · Oil ring, 12 · · Coil expander, 13 · · Upper rail, 14 · · Lower rail, 15 · · Web, 16 · · Window hole, 17 · · Expander mounting groove, 18 ..Axial wave type expander, 19 ..Upper piece, 20 ..Lower piece, 21 ..Connecting piece, 22 ..Outer peripheral surface, 23 ..Radial wave type expander, 24 ..Outer piece, 25..Inner piece, 26..Connecting piece, 27..Coil expander.

Claims (5)

There is a biasing means that presses the back surface of the coil expander of the oil ring with a coil expander in which the coil expander is disposed on the inner peripheral side of the oil ring, and the biasing means is provided at the bottom of the ring groove of the piston. A combination of an oil ring with a coil expander and a piston, wherein the oil ring is inserted into a recessed portion. A leaf spring having a plurality of hump said biasing means is circumferentially spaced, coil extract according to claim 1, characterized in that in contact with the bottom surface of the recess provided in the ring groove bottom Combination of oil ring with panda and piston. Coil expander with oil ring and a piston combination of claim 1 wherein said biasing means is a expander axial wave. Coil expander with oil ring and a piston combination of claim 1 wherein said biasing means is a expander radial wave. Coil expander with oil ring and a piston combination of claim 1 wherein said biasing means is a coil expander.

Images