JP3739479B2 - Combination oil control ring - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil control ring mounted on a piston of an internal combustion engine, and more particularly to a two-piece type combined oil control ring suitable for suppressing oil flowing into a combustion chamber of a high-speed internal combustion engine such as a gasoline engine.
[0002]
[Prior art]
A conventional oil control ring mounted on a piston of an internal combustion engine is, for example, a steel ring body disposed in a ring groove of an internal combustion engine and formed in an annular shape as disclosed in JP-A-5-231540 A coil expander that is disposed inside the ring body and elastically expands the ring body radially outward, and a pair of sides that are disposed on the upper and lower sides of the ring body and abuts against the inner wall of the cylinder of the internal combustion engine Rail. Recently, in order to reduce the weight and speed of the engine, a lightweight oil control ring has been desired, and a three-piece oil control ring has been developed that gives elasticity to the ring body and omits the coil expander. The three-piece oil control ring includes a spacer expander and a pair of side rails disposed above and below the spacer expander.
[0003]
However, an oil control ring having a thin structure in the vertical direction is further required. For example, as disclosed in JP-A-61-233265, JP-B-3-61860, JP-A-1-163446, etc. A so-called two-piece combined oil control ring comprising a spacer expander and one side rail has been developed. Such a two-piece combined oil control ring has various problems.
[0004]
[Problems to be solved by the invention]
That is, in the two-piece type combined oil control ring, since the slit is formed in the ring body in the radial direction and the peak portion that supports the outer peripheral portion of the side rail is formed integrally with the ring body, the peak portion has high rigidity. For this reason, when an external force in the radial direction is applied to the spacer expander, there is a drawback that the elastic deformation range of the peak portion is narrow and the bending allowance is small. For this reason, the followability to the outer peripheral direction of a side rail becomes inadequate with respect to a deformation | transformation of a cylinder. Further, the section modulus is increased, and the oil ring tension is excessively increased. Furthermore, in the oil control ring disclosed in Japanese Patent Publication No. 3-61860 and Japanese Patent Application Laid-Open No. 1-163446, the outer peripheral ridge portion supporting the outer peripheral end portion of the side rail has a solid structure, and the bending allowance in the vertical direction is small. Almost no gap is formed to let the oil scooped up during the ascending stroke escape downward. For this reason, there is a problem that a sufficient amount of oil cannot be released to the crank chamber during the upward stroke of the piston, resulting in an increase in oil consumption.
[0005]
It is an object of the present invention to provide a combined oil control ring that returns a sufficient amount of lubricating oil that is scraped during the upward stroke of the piston to the crank chamber.
[0006]
[Means for Solving the Problems]
The combined oil control ring according to the first embodiment of the present invention is arranged in the ring groove (5) of the piston (10), and is an annular spacer expander (slidably contacting the lower surface (5a) of the ring groove (5)). 2) and an annular side rail (3) disposed between the spacer expander (2) and the upper surface (5b) of the ring groove (5). The spacer expander (2) is spaced apart from each other and includes a pair of arm portions (6, 7) and a pair of arm portions (6, 7) extending perpendicularly to the axial direction of the piston in the radial direction. The spacer unit (4) formed by the base part (8) connected on the inner peripheral side and the ear part (9) formed axially upward from the base part (8), and the adjacent spacer unit (4) A connector (11) for connecting the arm portions (6, 7) on the outer peripheral side, and a tongue piece (12) extending obliquely upward from the outer peripheral side of the base portion (8) toward the radially outer side.
[0007]
The ear portion having an appropriate elasticity in the radial direction gives sufficient followability to the side rail against the deformation of the cylinder, and provides a good sealing property between the wall surface of the cylinder and the side rail. The elastic tongue is sufficiently bent by the frictional force with the cylinder wall surface when the piston is in the upward stroke, and a sufficiently large gap is formed between the side rail and the upper surface of the ring groove. The lubricating oil that has been scraped upward is returned to the crank chamber. For this reason, the amount of lubricating oil scooped up into the combustion chamber by the side rail is reduced, and the oil consumption can be reduced.
[0008]
In the second embodiment of the present invention, the spacer expander (2) is disposed so as to be spaced apart from each other, and extends in an upwardly inclined manner toward the radially outer side, and a pair of arms. Adjacent to the spacer unit (4) composed of the base part (8) for connecting the parts (6, 7) on the inner peripheral side and the ear part (9) formed axially upward from the base part (8). Connector (11) for connecting the arm portions (6, 7) of the spacer unit (4) to be connected on the outer peripheral side, and extending perpendicularly to the axial direction of the piston in the radial direction from the outer peripheral side of the base portion (8) A tongue piece (12). The second embodiment is an example in which the actions of the tongue piece (12) and the arm portions (6, 7) of the first embodiment are exchanged.
[0009]
In the third embodiment of the present invention, the spacer expander (2) is arranged apart from each other and extends in a radial direction perpendicular to the axial direction of the piston (6, 7), A spacer unit (4) comprising a base part (8) for connecting the pair of arm parts (6, 7) on the inner peripheral side and an ear part (9) formed upward from the base part (8) in the axial direction; A connector (11) for connecting the arm portions (6, 7) of the adjacent spacer unit (4) on the inner peripheral side, and a tongue piece extending obliquely upward from the outer peripheral side of the connector (11) toward the radially outer side ( And 12).
[0010]
In the third embodiment, it extends radially outward between the arm portions (6, 7) of adjacent spacer expanders (2), and is inclined away from the lower surface (5a) of the ring groove (5). The tongue piece (12) having elasticity is connected to the connector (11). The tongue piece (12) supports the lower surface (3c) near the outer peripheral end of the side rail (3). In the first embodiment, the tongue piece (12) is formed on the connector (11) between the pair of arm portions (6, 7).
[0011]
DETAILED DESCRIPTION OF THE INVENTION
First to fourth embodiments of a combined oil control ring according to the present invention will be described with reference to FIGS.
[0012]
1 and 2 show a combined oil control ring 1 according to a first embodiment of the present invention. The combination oil control ring 1 includes an annular spacer expander 2 that is disposed in the ring groove 5 of the piston 10 and has elasticity that slides on the lower surface 5 a of the ring groove 5, and upper surfaces of the spacer expander 2 and the ring groove 5. And an annular side rail 3 disposed between 5b and 5b. The spacer expander 2 includes a pair of arm portions 6 and 7 that are spaced apart from each other and arranged in the radial direction, and a base portion 8 that connects the pair of arm portions 6 and 7 and has an ear portion 9 formed thereon. And a spacer unit 4 formed in a U-shape. Although not shown, the spacer expander 2 and the side rail 3 are formed in an annular shape as a whole, and have an abutment portion separated at one place in the same manner as a normal piston ring. The spacer unit 4 is formed in a thin flat plate shape that is bent continuously, and the arm portions 6 and 7 of each adjacent spacer unit 4 are connected by a circumferential connector 11. The spacer expander 2 is formed on the base portion 8 and extends radially outward between the pair of arm portions 6, 7, and is inclined away from the lower side surface 5 a of the ring groove 5 and has an elastic tongue 12. And.
[0013]
The flat arm portions 6 and 7 form the base of the tongue piece 12 that is stably held on the lower side surface 5 a of the ring groove 5, and stabilize the posture of the space expander 2. The ear portion 9 rises vertically upward from the inner peripheral side of the base portion 8, and the upper end bends toward the inner peripheral side at an angle θ = 10 ° to 25 ° as shown in FIG. 9 a is formed at the same position as the height of the tip 12 a of the tongue piece 12. The ear 9 presses the outer peripheral end 3 a of the side rail 3 against the inner wall 13 a of the cylinder 13 with elasticity, and the inner peripheral end 3 b of the side rail 3 with elasticity against the upper side surface 5 b of the ring groove 5. Press. The tongue piece 12 rises from the outer peripheral side of the base portion 8 in a radially outward direction, and the tip 12a is bent to form a horizontal surface 12b. The tongue piece 12 supports the lower side surface 3 c near the outer peripheral end of the side rail 3. When the tongue 12 is horizontal, it does not protrude outward from the connector 11.
[0014]
By the thickness of the spacer expander 2 and the plate thickness of one side rail 3, the ring thickness can be reduced as compared with a conventional three-piece combination oil control ring. The side rail 3 is supported by the ear portion 9 and the tongue piece 12 of the spacer expander 2, and the ear portion 9 formed so as to protrude toward the upper side surface 5 b of the ring groove 5 is sufficiently elastic to the side rail 3 in the radial direction. give. Further, since the spacer unit 4 is formed in a shape that is continuously bent in the radial direction, the spacer unit 4 has sufficient elasticity in the circumferential direction, and the thickness or width dimension of the ear portion 9 is selected and the tension of the side rail 3 is selected. Can be adjusted. Further, since the oil control ring 1 as a whole can be deformed with respect to the external force applied via the side rail 3, it is possible to sufficiently follow the radial deformation of the cylinder 13. Since the tongue 12 protrudes from the spacer unit 4 in an inclined manner toward the upper surface 5b of the ring groove 5, the plate thickness, width and protruding dimensions can be selected and adjusted with optimum rigidity and flexibility. That is, assuming that the longitudinal elastic modulus of the tongue piece 12 is E, the secondary moment is I, the protrusion length is 1, and the deflection δ of the tongue piece 12 when a load W is applied to the tip 12a of the tongue piece 12 is δ = (Wl3) / 3EI. The rigidity is represented by EI.
[0015]
Therefore, the ear portion 9 having a small cross-sectional area and appropriate elasticity in the radial direction gives sufficient followability to the side rail 3 against the deformation of the cylinder 13, and the space between the wall surface of the cylinder 13 and the side rail 3. Good sealing performance is produced. In the ascending stroke of the piston 10, the side rail 3 is pushed toward the lower side surface 5 a of the ring groove 5 by the frictional force between the cylinder 13 and the side rail 3. Therefore, the elastic tongue 12 is greatly bent. A sufficiently large gap is formed between the side rail 3 and the upper side surface 5 a of the ring groove 5. For this reason, the lubricating oil scooped up in the ascending stroke passes through a gap formed between the side rail 3 and the upper side surface 5 a by the bending of the tongue piece 12, and the oil return hole 5 c formed in the back of the ring groove 5. It is returned to the oil pan. For this reason, the amount of lubricating oil supplied into the combustion chamber by the side rail 3 is reduced, and the oil consumption can be reduced.
[0016]
3 and 4 show a second embodiment of the present invention in which the actions of the tongue piece 12 and the arm portions 6 and 7 of the first embodiment are exchanged. As shown in FIGS. 3 and 4, the arm portions 6 and 7 of the adjacent spacer units 4 have elasticity and are inclined away from the lower surface 5 a of the ring groove 5. The arm portions 6 and 7 are connected by a circumferential connector 11, and a horizontal surface 11 b that supports the lower side surface 3 c in the vicinity of the outer peripheral end portion 3 a of the side rail 3 is formed at the tip 11 a of the connector 11. The tongue piece 12 formed on the base portion 8 forms the base of the tongue piece 12 stably held on the lower side surface 5a of the ring groove 5 and stabilizes the posture of the space expander 2.
[0017]
FIG. 5 shows a third embodiment of the present invention in which a tongue piece 12 provided between a pair of arm portions 6 and 7 is formed on a connector 11. As shown in FIG. 5, the connector 11 is connected between the arm portions 6 and 7 of the adjacent spacers 3, and the elastic tongue piece 12 connected to the connector 11 extends radially outward, and the ring groove 5 It inclines away from the lower surface 5a. The tongue piece 12 supports the lower side surface 3 c near the outer peripheral end 3 a portion of the side rail 3.
[0018]
FIG. 6 shows an example in which the connector 11 having the tongue piece 12 is connected to the outer end portions of the arm portions 6 and 7. As shown in FIG. 6, the tongue 12 having elasticity that supports the lower side surface 3 c near the outer peripheral end 3 a of the side rail 3 is connected to the connector 11, and is inclined away from the lower side surface 5 a of the ring groove 5. Extending radially outward.
[0019]
【The invention's effect】
Lubricant consumption by providing sufficient deflection allowance in the radial and vertical directions, increasing the vertical flexibility of the spacer expander, and reducing the amount of lubricant sent to the combustion chamber during the piston lift stroke Can be reduced. In addition, the frictional force of the combined oil control ring can be reduced, the amount of wear can be reduced, and the life of the internal combustion engine can be extended.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of a combined oil control ring according to the present invention. FIG. 2 is a cross-sectional view showing a state in which the combined oil control ring of FIG. FIG. 4 is a perspective view showing a second embodiment of a combined oil control ring according to the invention. FIG. 4 is a cross-sectional view showing a state where the combined oil control ring of FIG. 3 is mounted in a ring groove of a piston. FIG. 6 is a perspective view showing a third embodiment of the ring. FIG. 6 is a perspective view showing an example of a combined oil control ring.
1 ・ ・ Combination oil control ring, 2 ・ ・ Spacer expander, 3 ・ ・ Side rail, 4 ・ ・ ・ Spacer unit, 5 ・ ・ Ring groove, 6, 7 ・ ・ Arm part, 8 ・ ・ Base part, 9 ・・ Ear part, 10 ・ ・ Piston, 11 ・ ・ Connector, 12 ・ ・ Long piece, 13 ・ ・ Cylinder, 13a ・ ・ Inner wall,

Claims (3)

An annular spacer expander disposed in the ring groove of the piston and in sliding contact with the lower surface of the ring groove, and an annular side rail disposed between the spacer expander and the upper surface of the ring groove. In combination oil control ring,
The spacer expander is
A pair of arm portions that are spaced apart from each other and extend perpendicularly to the axial direction of the piston in the radial direction, a base portion that connects the pair of arm portions on the inner peripheral side, and an axially upward direction from the base portion A spacer unit composed of ears formed oppositely; and
A connector for connecting the arm portions of adjacent spacer units on the outer peripheral side;
A combined oil control ring comprising: a tongue piece extending obliquely upward from the outer peripheral side of the base portion toward the radially outer side. An annular spacer expander disposed in the ring groove of the piston and in sliding contact with the lower surface of the ring groove, and an annular side rail disposed between the spacer expander and the upper surface of the ring groove. In combination oil control ring,
The spacer expander is
A pair of arm portions that are spaced apart from each other and extend obliquely upward toward the outside in the radial direction, a base portion that connects the pair of arm portions on the inner peripheral side, and an axially upward direction from the base portion. A spacer unit constituted by the ears;
A connector for connecting the arm portions of adjacent spacer units on the outer peripheral side;
A combined oil control ring comprising a tongue piece extending perpendicularly to the axial direction of the piston from the outer peripheral side of the base portion toward the radial direction. An annular spacer expander disposed in the ring groove of the piston and in sliding contact with the lower surface of the ring groove, and an annular side rail disposed between the spacer expander and the upper surface of the ring groove. In combination oil control ring,
The spacer expander is
A pair of arm portions that are spaced apart from each other and extend perpendicularly to the axial direction of the piston in the radial direction, a base portion that connects the pair of arm portions on the inner peripheral side, and an axially upward direction from the base portion A spacer unit composed of ears formed oppositely; and
A connector for connecting the arm portions of the adjacent spacer units on the inner peripheral side;
A combined oil control ring comprising a tongue piece extending obliquely upward from the outer peripheral side of the connector toward the radially outer side.

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