JP6659892B2 - side rail - Google Patents

Description

  The present invention relates to a side rail which is combined with an annular spacer expander to form a combined oil ring for an internal combustion engine together with the spacer expander.

  The piston of a reciprocating engine (reciprocating internal combustion engine) is provided with an oil ring for controlling oil on the inner surface of the cylinder, in addition to a compression ring for sealing combustion gas. As such an oil ring, a combination oil ring formed by combining one or a pair of side rails with an annular spacer expander is often used.

  The side rail used for the combined oil ring is formed in a split ring shape with an abutment, and is urged by a spacer expander to increase the diameter, and a predetermined contact pressure (surface pressure) is applied to the inner surface of the cylinder on the outer peripheral surface. Touch with. Then, when the engine operates and the piston reciprocates, the side rail slides on the inner surface of the cylinder on its outer peripheral surface to form an oil film of an appropriate thickness on the inner surface of the cylinder and to remove excess oil adhering to the inner surface of the cylinder. Scratches toward the crankcase to prevent oil from rising.

  In recent years, as the performance of internal combustion engines has improved due to market demands such as low fuel consumption and low oil consumption, combined oil rings have also been required to control the oil scraping action during the piston up stroke (compression stroke and exhaust stroke) and to lower the piston. Amplification of the oil scraping action during the stroke (suction stroke and combustion stroke) has been demanded to have a performance capable of reducing oil consumption while reducing friction on the cylinder inner surface. In order to respond to such demands, side rails having various shapes on the outer peripheral surface facing outward in the radial direction have been proposed.

  For example, Patent Literature 1 discloses a side rail in which an outer peripheral surface facing outward in a radial direction is formed into a curved surface shape having a vertex at a center position in an axial direction and projecting outward in a radial direction.

JP 2003-194222 A

  In general, it is known that the friction between the side rail and the cylinder inner surface is reduced by reducing the contact width of the outer peripheral surface against the cylinder inner surface. The upper and lower (front and back) asymmetric shapes having various shape changes have been used.

  However, if the outer peripheral surface is formed in a vertically asymmetrical shape with a slight change in shape as described above, it is difficult to determine the direction of the upper and lower sides (front and back) of the side rail. However, there is a problem that the side rails may be assembled in an incorrect posture at the time of assembling into the ring groove or the like.

  An object of the present invention is to solve such a problem, and an object of the present invention is to provide a side rail in which it is easy to determine the vertical direction.

  The side rail of the present invention is formed in a split ring shape having an abutment, and is a side rail which is combined with an annular spacer expander to form a combined oil ring for an internal combustion engine together with the spacer expander, , An inner peripheral surface facing radially inward, a first axial side surface facing one side in the axial direction, and a second axial side facing the other side in the axial direction and parallel to the first axial side surface. And the outer peripheral surface has a chamfered portion with the second axial side surface, and the chamfered portion extends from the first axial side surface to the second axis. The taper surface is formed by a taper surface that gradually decreases in diameter toward the second axial side surface from a position on the outer peripheral surface separated by 0.05 mm or more in the axial direction toward the direction side surface. Formed on a convex curved surface Are, together with the grooves formed in concave curved surface on the tapered surface is provided, characterized in that said tapered surface and said groove are connected by the curved surface to each other.

  In addition, in the said structure, "the split ring shape provided with the abutting part" means that the oil ring main body is cut in a part of its circumferential direction and formed into a C-shape in which the cut part becomes the abutting part. Means that. The “axial direction” means a direction along the axis of the split ring-shaped side rail.

  According to the present invention, in the above configuration, the tapered surface is provided between the tapered surface main portion and the tapered surface main portion and the outer peripheral surface, and the inclination angle with respect to the axial direction is smaller than the tapered surface main portion. 1 taper surface sub-portion, and a second taper surface sub-portion provided between the taper surface main portion and the second axial side surface and having a larger inclination angle with respect to the axial direction than the taper surface main portion. It is preferred to have

  According to the present invention, in the above configuration, it is preferable that the chamfered portion is formed by a tapered surface whose diameter is linearly reduced.

  According to the present invention, in the above configuration, it is preferable that the chamfered portion is formed by a tapered surface curved in a concave shape.

  According to the present invention, in the above configuration, it is preferable that the chamfered portion is formed by a tapered surface curved in a convex shape.

  According to the present invention, in the above configuration, it is preferable that a step cut portion is formed on the tapered surface.

  According to the present invention, since the chamfered portion with visibility is provided between the outer peripheral surface and the second axial side surface, even if the side rail has the up-down (front and back) directionality, By visually observing the chamfered portion at the time of assembling the piston or the piston into the ring groove, it is possible to easily determine whether the side rail is up or down.

  As described above, according to the present invention, it is possible to provide a side rail in which it is easy to determine the vertical direction.

It is a top view of the combination oil ring provided with the side rail which is one embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing a use state of the combined oil ring shown in FIG. 1. It is a top view of the side rail shown in FIG. FIG. 4 is a sectional view taken along line AA in FIG. 3. It is a modification of the side rail shown in FIG. 4, and is a sectional view when the chamfered portion is formed by a tapered surface having a tapered surface main portion and two tapered surface sub-portions. FIG. 13 is a cross-sectional view of a modified example of the side rail shown in FIG. 4, in which a chamfered portion is formed by a tapered surface that curves in a concave shape. FIG. 11 is a cross-sectional view of a modified example of the side rail shown in FIG. 4, in which a chamfered portion is formed by a tapered surface that curves in a convex shape. FIG. 10 is a cross-sectional view of a modified example of the side rail shown in FIG. 4 when a step cut portion is formed on a tapered surface. FIG. 10 is a cross-sectional view of a modified example of the side rail shown in FIG. 4 when a concave groove is formed on a tapered surface.

  Hereinafter, the present invention will be described more specifically with reference to the drawings.

  As shown in FIG. 1, a side rail 1 according to an embodiment of the present invention forms a combined oil ring (oil control ring) 3 together with a spacer expander 2. In the illustrated case, the combination oil ring 3 is of a three-piece type in which a pair of side rails 1 are combined on both axial sides of a spacer expander 2, and as shown in FIG. It is used by being mounted on a ring groove 4a formed on the outer peripheral surface of the piston 4 of the engine.

  The combination oil ring 3 may be a two-piece type in which only one side rail 1 is combined with the spacer expander 2.

  The spacer expander 2 is formed of a steel material into an annular shape that is elastically deformable in the radially inward and outward directions. It is urged to expand the diameter outward and axially outward.

  A pair of side rails 1 according to an embodiment of the present invention have the same configuration with each other, and as shown in FIG. 3, a long flat plate-like steel material (steel material) is bent to form a joint 10. It is formed in a split ring shape provided. That is, the side rail 1 is formed in a C-shape in which a part of the side rail in the circumferential direction is cut and the cut part becomes the abutment 10. The side rails 1 can be elastically deformed so as to increase the space between the abutments 10 in the circumferential direction, and can be expanded radially outward.

  As shown in FIG. 4, the side rail 1 has a first axial side surface 11 facing one side (lower side in the figure) in the axial direction, and a second axis facing the other side (upper side in the figure) in the axial direction. A directional side surface 12, an inner peripheral surface 13 facing radially inward, and an outer peripheral surface 14 facing radially outward are provided, and a cross-sectional shape perpendicular to the circumferential direction is substantially uniform over the entire circumference. The “axial direction” is a direction along the axis of the split ring-shaped side rail 1.

  The first axial side surface 11 is formed as a flat surface perpendicular to the axial direction. As shown in FIG. 2, the first axial side surface 11 is directed toward the crankcase side of the engine when the combined oil ring 3 using the side rail 1 is mounted on the piston 4.

  As shown in FIG. 4, the second axial side surface 12 is formed as a flat surface perpendicular to the axial direction, that is, parallel to the first axial side surface 11. As shown in FIG. 2, the second axial side surface 12 is directed toward the combustion chamber of the engine when the combined oil ring 3 using the side rail 1 is mounted on the piston 4.

  In the illustrated case, the axial distance between the pair of axial side surfaces 11 and 12 of the side rail 1, that is, the axial thickness (rail width) W of the side rail 1 is 0.35 mm, and the inner peripheral surface 13 and the outer peripheral surface 14 , That is, the radial length L is 1.52 mm.

  As shown in FIG. 4, the inner peripheral surface 13 of the side rail 1 is formed in a curved surface shape (barrel face) having an apex at a central position in the axial direction. As shown in FIG. 2, the inner peripheral surface 13 of the side rail 1 comes into contact with the seating surface 2 a of the spacer expander 2 in a state where the combined oil ring 3 using the side rail 1 is mounted on the piston 4.

  Note that the inner peripheral surface 13 is not limited to the above shape, and various shapes such as a cylindrical surface shape parallel to the axial direction can be adopted.

  As shown in FIG. 4, the outer peripheral surface 14 of the side rail 1 is formed in a cylindrical shape parallel to the axial direction. As shown in FIG. 2, the side rail 1 is in contact with the cylinder inner surface 20 at the outer peripheral surface 14.

  In this side rail 1, a chamfered portion 30 is provided at one end of both ends in the axial direction of the outer peripheral surface 14. That is, the chamfered portion 30 is provided between the outer peripheral surface 14 and the second axial side surface 12. The portion between the outer peripheral surface 14 and the first axial side surface 11 may be formed in a shape without a chamfered portion, but may be formed in a rounded R shape. The radial width and the axial width are formed smaller than the chamfered portion 30.

  The chamfered portion 30 is located on the outer peripheral surface 14 where the axial distance B from the first axial side surface 11 to the second axial side 12 surface is 0.05 mm or more, that is, the first axial side surface 11. The starting point is a position on the outer peripheral surface 14 which is separated by 0.05 mm or more in the axial direction from the starting point to the second axial side 12 surface, and the diameter is gradually reduced from the starting point toward the second axial side surface 12. It is formed by a tapered surface 30 a extending to the second axial side surface 12.

  In addition, the axial distance B serving as the starting point of the chamfered portion 30 is more preferably set to 0.10 mm or more.

  In the case shown in FIG. 4, the tapered surface 30a is formed in a shape (conical surface shape) in which the diameter is reduced linearly, that is, a linear tapered surface. In this case, the angle θ formed by the tapered surface 30a with respect to the axial direction is preferably set to be larger than 10 °, and more preferably 30 ° or more.

  Further, the radial length T of the tapered surface 30a is preferably set to 0.05 mm or more.

  As described above, in the side rail 1 of the present invention, the chamfered portion 30 having visibility is provided at one end of the both ends in the axial direction of the outer peripheral surface 14. Even if the side rails have a vertical (front and back) directionality, the chamfered portion 30 can be visually checked at the time of manufacturing the side rails 1 and at the time of assembling the pistons into the ring grooves, etc. Upper and lower sides can be easily distinguished. Therefore, it is possible to prevent the side rails 1 from being erroneously assembled into an incorrect posture during the work.

  The chamfered portion 30 may be formed in a shape obtained by combining a plurality of tapered surfaces. For example, as shown in FIG. 5, a tapered surface constituting the chamfered portion 30 is provided between the tapered surface main portion 30a1 inclined at an angle θ1 with respect to the axial direction and the tapered surface main portion 30a1 and the outer peripheral surface 14. A first tapered surface sub-portion 30a2 inclined with respect to the axial direction at an angle θ2 smaller than the tapered surface main portion 30a1, and provided between the tapered surface main portion 30a1 and the second axial side surface 12. A second tapered surface sub-portion 30a3 inclined with respect to the axial direction at an angle θ3 larger than the tapered surface main portion 30a1 can be provided.

  As described above, by configuring the chamfered portion 30 to have a shape in which a plurality of tapered surfaces are combined, it is possible to secure the radial length T of the chamfered portion 30 and improve the visibility thereof, and to improve the visibility of each of the tapered surface sub-portions 30a2, The angle of incidence on the outer peripheral surface 14 and the second axial side surface 12 can be reduced by 30a3. As a result, the chamfered portion 30 prevents the oil from being scooped up by the edge of the outer peripheral surface 14 with respect to the inner surface 20 of the cylinder, thereby reducing oil consumption, and further allowing oil to flow between the second axial side surface 12 and the inner surface of the ring groove 4a. By positively introducing the side rail 1, the friction of the side rail 1 with respect to the inner surface of the ring groove 4a can be reduced.

  As shown in FIG. 6, the tapered surface 30a of the chamfered portion 30 can be formed in a concavely curved shape. In this case, the tapered surface 30a preferably has a curved shape having a constant radius of curvature, but may have a curved shape in which the radius of curvature changes gradually.

  In addition, as shown in FIG. 7, the tapered surface 30a of the chamfered portion 30 may be formed in a shape that is convexly curved. Also in this case, it is preferable that the tapered surface 30a has a curved shape having a constant radius of curvature. However, the tapered surface 30a may have a curved shape in which the radius of curvature changes gradually.

  In this manner, by forming the chamfered portion 30 by the tapered surface 30a that is curved in a concave or convex shape, the chamfered portion 30 can be more easily visually recognized, and the vertical determination of the side rail 1 can be further facilitated. .

  Further, as shown in FIG. 8, the chamfered portion 30 may have a configuration in which a step cut portion 31 is formed on the tapered surface 30a. The step cut portion 31 has a vertical surface 31a perpendicular to the axial direction and a parallel surface 31b parallel to the axial direction, and is provided substantially at the center of the tapered surface 30a.

  By providing such a step cut portion 31 on the tapered surface 30a, the chamfered portion 30 can be more easily visually recognized, and the vertical determination of the side rail 1 can be further facilitated.

  As shown in FIG. 9, the chamfered portion 30 may have a configuration in which a concave groove 32 is formed in the tapered surface 30a instead of the step cut portion 31.

  In this case, the tapered surface 30a is formed in a convexly curved surface that smoothly curves, and the concave groove 32 is formed in a concavely curved surface that smoothly curves, and is provided substantially in the center of the tapered surface 30a. I have. The tapered surface 30a and the groove 32 are connected to each other by a smooth curved surface, and the tapered surface 30a is also connected to the outer peripheral surface 14 and the second axial side surface 12 smoothly.

  By providing such a concave groove 32 on the tapered surface 30a, the chamfered portion 30 can be more easily visually recognized, and the vertical determination of the side rail 1 can be further facilitated. In addition, the tapered surface 30a constituting the chamfered portion 30 is formed into a convex curved surface that smoothly curves, so that the radial length T of the chamfered portion 30 is ensured and the visibility thereof is improved, while the tapered surface 30a is improved. Thereby, the incident angle with respect to the outer peripheral surface 14 and the second axial side surface 12 can be reduced. Thereby, in the piston ascent stroke, the chamfered portion 30 prevents the oil from being scooped up by the edge of the outer peripheral surface 14 with respect to the inner surface 20 of the cylinder to reduce oil consumption, and furthermore, the second axial side surface 12 and the inner surface of the ring groove 4a. The oil can be positively introduced into the gap between the side rails 1 to reduce the friction on the inner surface of the ring groove 4a of the side rail 1.

  Although not shown in detail, a configuration in which a hard coating (hard layer) is provided on at least the surface of the outer peripheral surface 14 and the chamfered portion 30, that is, the tapered surface 30a, may be employed. As the hard coating, for example, a configuration including at least one of a nitriding layer, a PVD processing layer, a hard chromium plating layer, and a DLC layer can be adopted.

  The “PVD treatment layer” means “a layer formed by physical vapor deposition (Physical Vapor Deposition)”, and the “DLC (Diamond Like Carbon) layer” is a non-hydrogen layer mainly composed of an allotrope of hydrocarbon or carbon. It means a crystalline hard carbon film.

  By providing such a hard coating, there is no change in shape due to wear of the outer peripheral surface 14, the outer peripheral surface shape is maintained, the decrease in surface pressure is small, the oil control function is maintained, and the oil consumption over a long period is reduced. The effect of reducing the fuel consumption of the engine can be obtained while reducing the color, and the hue of the chamfered portion 30 visually recognized can be more clearly changed with respect to the second axial side surface 12 and the outer peripheral surface 14. . In particular, when the outer peripheral surface 14 is subjected to a lapping process, the hue difference becomes larger. Therefore, by providing the hard coating, the chamfered portion 30 can be more easily visually recognized, and the vertical determination of the side rail 1 can be further facilitated.

  4 has an axial thickness (W) of 0.35 mm, an axial distance (B) indicating the chamfered position of the chamfered portion is 0.15 mm, and an angle (θ) of the tapered surface of the chamfered portion with respect to the axial direction. ) Was set to 30 °, and 100 side rails were prepared, and the vertical direction of these side rails was visually discriminated by 10 workers. As a result, the operator was able to correctly determine the vertical direction of all the side rails.

  The present invention is not limited to the above embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the outer peripheral surface 14 has a cylindrical shape parallel to the axial direction. However, the outer peripheral surface 14 may be formed in another shape such as a vertically (front and back) asymmetric shape having a small change in shape. it can.

DESCRIPTION OF SYMBOLS 1 Side rail 2 Spacer expander 2a Bearing surface 3 Combined oil ring 4 Piston 4a Ring groove 10 Joint 11 First axial side surface 12 Second axial side surface 13 Inner peripheral surface 14 Outer peripheral surface 20 Cylinder inner surface 30 Chamfered portion 30a Tapered surface 30a1 Tapered surface main portion 30a2 First tapered surface subportion 30a3 Second tapered surface subportion 31 Step cut portion 31a Vertical surface 31b Parallel surface 32 Concave groove W Axial thickness L Radial length B Axial distance θ Angle T Radial length θ1 Angle θ2 Angle θ3 Angle

Claims (6)

A side rail which is formed in a split ring shape with an abutment and is combined with an annular spacer expander to form a combined oil ring for an internal combustion engine together with the spacer expander,
An outer peripheral surface facing radially outward,
An inner peripheral surface facing inward in the radial direction,
A first axial side surface facing one side in the axial direction;
A second axial side surface that faces the other side in the axial direction and is parallel to the first axial side surface;
The outer peripheral surface has a chamfer between the second axial side surface,
The side of the second axial side surface starting from a position on the outer peripheral surface separated from the first axial side surface by 0.05 mm or more in the axial direction from the first axial side surface toward the second axial side surface. Formed by a tapered surface that gradually decreases in diameter toward
The tapered surface is formed in a convex curved surface, a concave groove formed in a concave curved surface is provided in the tapered surface, and the tapered surface and the concave groove are connected to each other by a curved surface. Side rails characterized by that. The tapered surface,
A tapered surface main portion;
A first tapered surface sub-portion that is provided between the tapered surface main portion and the outer peripheral surface and has a smaller inclination angle with respect to the axial direction than the tapered surface main portion;
A second tapered surface sub-portion provided between the tapered surface main portion and the second axial side surface and having a larger inclination angle with respect to the axial direction than the tapered surface main portion. Item 2. The side rail according to item 1.   3. The side rail according to claim 1, wherein the chamfered portion is formed by a tapered surface having a linearly reduced diameter. 4.   The side rail according to claim 1, wherein the chamfered portion is formed by a tapered surface curved in a concave shape.   The side rail according to claim 1, wherein the chamfered portion is formed by a tapered surface curved in a convex shape.   The side rail according to claim 1, wherein a step cut portion is formed on the tapered surface.

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