JPH0544527Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an oil ring used for lubricating oil control among piston rings used in internal combustion engines. More specifically, it relates to an improvement in a combination oil ring consisting of a spacer expander and side rails that are disposed above and below the spacer expander and are pressed in the outer circumferential direction by the spacer expander to press against the inner wall surface of the cylinder. It is.

<Prior art> In a reciprocating internal combustion engine, as the piston reciprocates, lubricating oil is efficiently scraped from the inner wall of the cylinder, and the lubricating oil is skillfully circulated back into the cylinder to prevent it from entering the combustion chamber. An oil ring is installed in the ring groove. This kind of oil ring is
Various shapes have been devised to improve not only the material quality but also the functionality. Conventionally, there is an oil ring disclosed in Japanese Utility Model Application Laid-open No. 56-99154 as an effective oil ring for improving the lubricating oil consumption of a reciprocating internal combustion engine. This type of oil ring is composed of a spacer expander 2 and a pair of side rails 3, 3 disposed above and below the spacer expander. and,
When installed in the oil ring groove 61 of the piston 6 and inserted into the cylinder 4, the inner peripheral surface of the side rail 3 protrudes upward and downward on the inner peripheral side of the spacer expander 2 while being inclined radially inward. It is in contact with the pad part 21, and is pressed not only in the outer circumferential direction but also in the vertical direction by the expansion force of the spacer expander through the pad part 21, so that the outer circumferential surface 5 slides into pressure contact with the inner wall of the cylinder 4, and has an oil scraping effect. This also provides a sealing effect on the side wall surface of the oil ring groove 61. The conventional combination oil ring exhibits a good effect of reducing lubricating oil consumption due to the above-mentioned action. However, due to usage conditions that have become increasingly severe in recent years, in the case of conventional combination oil rings, the side rail vibrates in the circumferential direction as the piston reciprocates up and down, as shown in Figure 2, and the side rail protrudes into the center of its thickness. There was a defect in that a portion of the pad portion 21 was concentrated at one point, and the contact portion was worn out.

<Problems to be solved by the invention> In view of the above, the purpose of the invention is to improve the contact condition between the inner circumferential surface of the side rail of the combination oil ring and the pad part of the spacer expander, and to It is an object of the present invention to provide a combination oil ring that reduces wear at the part that comes into contact with a pad part and maintains good functionality over a long period of time.

<Means for Solving the Problems> In order to achieve the above object, the features of the present invention include a combination of a spacer expander and a pair of side rails disposed above and below the spacer expander. In the oil ring,
The pad portion of the spacer expander that contacts the inner circumferential surface of the side rail is inclined in the inner circumferential direction, and isosceles extending from both ends symmetrically in the vertical direction of the cross section of the inner circumferential surface of the side rail to make surface contact with the surface of the pad portion. The reason is that the central part is shaped like an arc.

The combination oil ring of the present invention solves the problem of conventional combination oil rings in which the inner peripheral surface of the side rail and the pads of the spacer expanders that contact the inner peripheral surface deteriorate due to accelerated wear. The cross-sectional shape of the circumferential surface has been newly improved.

<Function> In this way, in the combined oil ring of the present invention, the cross section of the inner surface of the side rail is formed of isosceles extending from both ends symmetrically in the vertical direction, and the central portion is arc-shaped so that it can come into surface contact with the surface of the pad portion of the spacer expander. This reduces wear on the inner surface of the side rail and the pad portion of the spacer expander, and allows the ring to maintain its function for a long period of time.

<Example> An example embodying the present invention will be described below based on the drawings.

In FIG. 3, the spacer expander 2 is shaped into a radial wave shape and has a spring structure compressible in the circumferential direction as shown in FIG. 1, but it can also be formed into an axial wave shape or a U-shape. A pad portion 21 that is inclined radially inward is provided on the inner peripheral side thereof.

Side rails 3, 3 are disposed above and below the spacer expander 2, and the inner circumferential surface of the side rails is in contact with the pad portion 21 of the spacer expander 2, and the expansion force of the spacer expander is applied to the outer circumferential direction. and is pressed in the vertical direction, and its outer peripheral surface is pressed against the inner wall of the cylinder.

Here, in the present invention, as shown in FIGS. 3 and 4, the cross-sectional shape 31 of the inner circumferential surface of the side rail is arranged at both ends symmetrically with respect to the center of the width B of the side rail so as to be in surface contact with the surface of the pad portion. It consists of isosceles extending from the center, and the central part is shaped like an arc. Since the inner peripheral surface of the side rail is configured as described above, even if the side rail swings in the circumferential direction due to the up and down reciprocation of the piston, stress will not be concentrated on the pad and rapid wear will be avoided. Does not occur.
The side rails above are made from steel ribbon,
Its inner peripheral surface can be easily formed by drawing or the like from a deformed wire.

<Effects of the Invention> Since the combination oil ring of the present invention is configured as conventionally, the pad portion of the spacer expander and the inner circumferential surface of the side rail face each other in surface contact from the time of installation. Therefore, wear at the contact points is reduced compared to the conventional case, and even if the side rail swings in the circumferential direction, rapid wear can be prevented, and good characteristics can be maintained over a long period of time. Furthermore, since the cross-sectional shape of the inner circumferential surface of the side rail is vertically symmetrical, compatibility between the upper and lower side rails is obtained, and the work of installing the combined oil ring into the oil ring groove is facilitated. The practical benefits of being able to do this and putting it into practice are enormous.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a state in which a conventional combination oil ring is installed. FIG. 2 is a partial sectional view of a conventional combination oil ring. FIG. 3 is a partial sectional view showing an embodiment of the present invention. The symbols in the diagram are 1...Combination oil ring, 2...Spacer expander, 3, 3'...
...side rail, 4... cylinder, 5... outer peripheral surface of side rail, 6... piston, respectively.

Claims (1)

[Claim for Utility Model Registration] In a combination oil ring consisting of a spacer expander and a pair of side rails disposed above and below the spacer expander, the pads of the spacer expander that come into contact with the inner peripheral surface of the side rails The cross section of the inner circumferential surface of the side rail is inclined in the inner circumferential direction, and the cross section of the inner circumferential surface of the side rail is symmetrical in the vertical direction and has an arcuate central portion formed by isosceles extending from both ends. Features a combination oil ring.