JPH0143490Y2 - - 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 reciprocating internal combustion engines. More specifically, a spacer expander, and sides that are disposed above and below the spacer expander and are pressed in the outer circumferential direction by the spacer expander to come into pressure contact with the inner wall surface of the cylinder and also with the upper and lower surfaces of the ring groove of the piston. This invention relates to an improvement of a combination oil ring consisting of a rail.

<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 skillfully circulated back 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. As shown in Japanese Patent Publication No. 33-10104, the oil ring that has been most commonly used in the past is made up of a corrugated flat plate as a whole, and the corrugation has a series of outer convex portions and inner convex portions. A spacer expander is formed into an annular shape in which outer protrusions and inner protrusions are arranged alternately and protrusions are provided on the upper and lower end surfaces of each inner protrusion, and both upper and lower ends of the annular spacer expander are provided. The inner annular surface of each side rail is supported by the protrusion, the outer peripheral surface of the side rail is in contact with the inner wall of the cylinder, and the upper and lower surfaces of the side rail are placed on the ring groove of the piston. There is a combination oil ring configured to press against the lower surface. Although its performance has been demonstrated satisfactorily, in recent years usage conditions have become increasingly severe, requiring improvements in initial conformability to the cylinder inner wall surface and ability to follow deformation of the cylinder surface, as well as always ensuring a sufficient seal. It has become difficult to maintain the uniform pressing force necessary to maintain the properties of the product.

<Problems to be solved by the invention> In view of the above, the purpose of the invention is to improve the spacer expander of the combination oil ring and improve its followability to the cylinder and the top and bottom surfaces of the piston ring groove. The object of the present invention is to provide a combination oil ring in which the surface pressures of the oil rings are sufficiently uniform.

<Means for Solving the Problems> In order to achieve the above object, the features of the present invention consist of a corrugated flat plate having an annular shape as a whole, and the corrugation has a series of outer convex portions and a series of inner convex portions. The convex portions are connected by a connecting member extending in the radial direction, and the upper and lower edges of the inner convex portion in the axial direction are provided with spacer expanders integrally provided with protrusions. In a combination oil ring consisting of a pair of side rails arranged above and below a spacer expander, slits extending in the axial direction and having a cut at either the upper or lower ends are arranged at regular intervals over the entire circumference of the spacer expander. The reason is that it is set up as follows.

The combination oil ring of the present invention uses a spacer expander to solve the problem of conventional combination oil rings in that the ability to follow the upper and lower surfaces of the cylinder and piston ring grooves and the surface pressure that influences the followability are not sufficiently uniform. It has a new structure.

<Function> As described above, in the combination oil ring of the present invention, the slits are alternately provided at regular intervals by press punching or the like over the entire circumference of the spacer expander, so flexibility is increased in the vertical and circumferential directions. Therefore, the followability of the side rail to the upper and lower surfaces of the cylinder and ring groove is improved, uniform surface pressure distribution is obtained, and lubricating oil consumption can be reduced. The size and number of the slits are determined depending on the elastic modulus of the spacer expander and other necessary conditions.

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

FIG. 1 shows a state in which the combination oil ring of the present invention is mounted on a piston of a reciprocating internal combustion engine. 6 in the figure is the piston, and its oil ring groove 6
A combination oil ring 1 is attached to 1. The combination oil ring consists of a pair of side rails 3, 3
and a spacer expander 2 interposed therebetween to hold the side rail 3 and press it against the cylinder inner wall 4. The spacer expander 2 is formed into a radially corrugated shape, and the inner convex portion 21 thereof has protrusions 211 that contact the inner peripheral side surface of the side rail 3 and are spaced apart from each other on the circumferential side surface of the spacer expander 2. has.
The protrusion 211 has an angle with respect to the axial direction. This is to press the side rail 3 not only in the radial direction but also in the vertical direction to obtain a sealing effect on the cylinder inner wall 4 and the side wall surface of the oil ring groove 61.

Reference numeral 62 is a hole for returning the oil in the oil ring groove 61 to the inside of the piston. The side rail 3 is made of a steel ribbon, and the outer peripheral surface 5 of the side rail 3 may be subjected to surface treatment such as hard chrome plating, if necessary.

FIG. 2 is a perspective view showing a part of the spacer expander according to the present invention, and the spacer expander 2 is composed of an annular corrugated flat plate as a whole.
A series of inner convex portions 21 and a series of outer convex portions 22 are arranged alternately, and these convex portions are connected by a connecting member 23 to form a wave shape in the circumferential direction. As described above, projections 211 extending in the axial direction are provided at both upper and lower ends of each of the inner convex portions 21, and a pair of side rails are provided to engage with the projections 211. In the present invention, the spacer expander 2
Slits 212 having cuts on either side of the upper and lower projections 211 and extending in the axial direction are provided alternately at regular intervals in the inner convex portion 21 extending over the entire circumference. This slit can be easily formed by press punching or the like. By configuring it in this way, the flexibility of the spacer expander in the vertical and circumferential directions is increased, which improves the ability to follow the top and bottom surfaces of the cylinder and piston ring grooves of the side rails, and provides uniform surface pressure. It is something. Furthermore, the weight of the spacer expander can be reduced, leading to improved check valve action. In the figure, one slit is provided in each inner convex portion, but the number and position of the slits can be determined depending on the elastic modulus of the spacer expander and other necessary conditions.

3 and 4 are perspective views showing a part of a spacer expander according to another embodiment of the present invention, in which the slit 212 is a feature of the present invention.
are alternately provided on the outer convex portion 22 or the connecting member 23 over the entire circumference of the spacer expander 2, respectively. The effect is similar to that of the first embodiment of the present invention shown in FIG.

Incidentally, reference numeral 24 in FIGS. 2, 3, and 4 indicates a perforated hole for oil circulation, but since the aforementioned slit, which is a feature of the present invention, also serves this purpose, it may not be necessary to provide it in some cases.

<Effects of the invention> As mentioned above, in the present invention, since the spacer expander is properly provided with slits, the flexibility of the spacer expander in the vertical and circumferential directions is increased, and therefore the cylinder and piston of the side rail are The ability to follow the upper and lower surfaces of the ring groove is improved, uniform surface pressure can be obtained, and the weight can be further reduced. Therefore, the combination oil ring of the present invention can improve the sealing effect and reduce the consumption of lubricating oil, and the practical benefits of its implementation are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a combination oil ring of the present invention installed in an oil ring groove of a piston, and FIG. 2 is a partially cutaway perspective view showing an embodiment of the combination oil ring of the present invention. Yes, 3rd
FIG. 4 is a partially cutaway perspective view showing another embodiment of the combination oil ring of the present invention. Symbols in the drawings are: 1...Combination oil ring, 2...Spacer expander, 21...Inner convex portion, 22...Outer convex portion, 23...Connection member,
211...Protrusion, 212...Slit, 3...Side rail, 4...Cylinder inner wall, 5...Side rail outer peripheral surface, 6...Piston.

Claims (1)

[Claims for Utility Model Registration] (1) Consisting of an annular corrugated flat plate as a whole, the corrugations include a series of outer convex portions and a series of inner convex portions alternately, and both of these convex portions extend in the radial direction. The spacer expander is connected by a connecting member, and has projections integrally formed on the upper and lower axial edges of the inner convex portion, and a pair of side rails arranged above and below the spacer expander. 1. A combination oil ring characterized in that slits extending in the axial direction and having cuts on either of the upper and lower ends of the spacer expander are alternately provided at regular intervals over the entire circumference of the spacer expander. (2) The combination oil ring according to claim 1, wherein the slit is provided in the inner convex portion extending over the entire circumference of the spacer expander in the combination oil ring. (3) The combination oil ring according to claim 1, wherein the slit is provided in the outer convex portion extending over the entire circumference of the spacer expander in the combination oil ring. (4) The combination oil ring according to claim 1, wherein the slit is provided in the connecting member extending around the entire circumference of the spacer expander.