JPH065104B2 - Combination oil ring - Google Patents

Description

TECHNICAL FIELD The present invention relates to an oil ring used for lubricating oil control, among piston rings used in a reciprocating internal combustion engine. More specifically, a spacer expander, and a side that is disposed above and below the spacer expander and is pressed in the outer peripheral direction by the spacer expander to be pressed against the inner wall surface of the cylinder and also to the upper and lower surfaces of the ring groove of the piston. The present invention relates to an improved combination oil ring including a rail.

<Prior art> In a reciprocating internal combustion engine, in order to efficiently scrape the lubricating oil on the inner wall surface of the cylinder along with the reciprocating motion of the piston and to make it circulate and return it so that it does not go to the combustion chamber, The oil ring is installed in the ring groove. Such an oil ring is variously devised in order to improve its function as well as its material. As the oil ring most often used conventionally, for example, there is an oil ring disclosed in Japanese Patent Publication No. 33-10104. This oil ring is an oil ring as shown in FIGS. 4 and 5, and the spacer expander used in this oil ring is composed of a corrugated template as a whole as shown in FIG. Outer protrusions and inner protrusions are alternately arranged with protrusions 22 and inner protrusions 21, and protrusions 211 are provided on the upper and lower end surfaces of the inner protrusions, respectively. The spacer expander 2 has a pressure-receiving surface 221 that integrally supports side rails provided at its end and is annularly formed. As shown in FIG. 5, this annular spacer expander is composed of a pair of annular side rails 3 and 3 arranged on both upper and lower end surfaces, and each side rail inner annular surface is supported by the projection 211, and the side rail outer periphery is supported. The combined oil ring is configured so that its surface abuts on the cylinder inner wall 4 and the upper and lower surfaces of the side rail are brought into pressure contact with the upper and lower surfaces of the ring groove 61 of the piston. Although its function has been fully demonstrated, it has become difficult to maintain a uniform surface pressure distribution on the upper and lower surfaces of the ring groove of the piston due to the side rail due to the increasingly severe operating conditions in recent years, and a sufficient seal has been achieved. This brings about a problem that the effect is not obtained and therefore the consumption of lubricating hot water is increased.

<Problems to be solved by the invention> In view of the above, an object of the present invention is to improve the spacer expander of the combined oil ring, and to improve the followability to the piston ring groove upper and lower surfaces and the cylinder followability,
An object of the present invention is to provide a combined oil ring in which the surface pressures of the two are sufficiently equal.

<Means for Solving Problems> In order to achieve the above-mentioned object, the characteristic means of the present invention is:
It consists of an annular corrugated flat plate as a whole, and the corrugation is provided with a series of outer convex portions and a series of inner convex portions alternately, and these both convex portions are connected by a connecting member extending in the radial direction. In a combined oil ring including a spacer expander having projections integrally provided on the upper and lower ends of the spacer in the axial direction, and a pair of side rails arranged above and below the spacer expander, an outer protrusion of the spacer expander is provided. Forming a side rail pressure receiving portion having at least one of upper and lower ends in the axial direction and a projecting portion which is integrally connected in the circumferential direction of at least one of the upper and lower ends and is separated from at least the connecting member. I have done so.

The combination oil ring of the present invention has a spacer expander in order to solve the problem that the conventional combination oil ring does not have a sufficiently uniform surface pressure that influences the upper and lower surfaces of the piston ring groove and the cylinder and the following characteristics. It has a new structure.

<Operation> As described above, in the combined oil ring of the present invention, at least one of the axially upper and lower ends of the outer convex portion of the spacer expander and at least one of the upper and lower ends thereof are integrally connected in the circumferential direction. However, since the side rail pressure-receiving portion having at least a protruding portion separated from the connecting member by press punching or the like is formed, by increasing the pressure-receiving area with the side rail, the side rail can be pressed against the ring groove upper and lower surfaces of the piston. The surface pressure distribution can be maintained evenly, a sufficient sealing effect can be obtained, the followability of the oil ring to the cylinder can be improved, and the consumption of lubricating oil can be reduced. The length, axial width, etc. of the projecting portion of the Sairail pressure-receiving portion are determined according to the strength of the spacer expander and other necessary conditions.

<Example> An example in which the present invention is embodied will be described below with reference to the drawings. In the conventional combined oil ring, the same parts as those described in FIGS. 4 and 5 are designated by the same reference numerals.

FIG. 1 shows a state in which the combined oil ring of the present invention is mounted on a piston of a reciprocating internal combustion engine. Reference numeral 6 in the drawing denotes a piston, and the combined oil ring 1 is mounted in the oil ring groove 61 thereof. The combined oil ring is composed of a pair of side rails 3, 3 and a spacer expander 2 interposed between them to hold the side rail 3 and press it against the cylinder inner wall 4. The spacer expander 2 is formed in a wave shape in the radial direction, and the inner convex portion 21 thereof is in contact with the inner peripheral side surface of the side rail 3 and is provided on the peripheral side surface of the spacer expander 2 so as to be spaced apart therefrom. Have. The protrusion 211 has an angle with respect to the axial direction. This is to press the side rails 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 surfaces 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 rails 3 are made of steel ribbon, of which the outer peripheral surface 5 may be subjected to surface treatment such as hard chrome plating or nitriding treatment if necessary.

FIG. 2 shows the outline of the spacer expander 2 of the present invention, and FIG. 3 shows a perspective view which is a part thereof. As shown in the figure, the spacer expander 2 is composed of an annular corrugated flat plate as a whole, and a series of inner convex portions 21 and a series of outer convex portions 22 are alternately arranged. It is connected and formed in a wavy shape in the circumferential direction. Protrusions 21 extending in the axial direction are provided at the upper and lower ends of each inner convex portion 21.
1 is provided, and the pair of side rails is arranged so as to be engaged with this, as described above.

In the present invention, as shown in FIG. 3, the upper and lower axial ends 25a, 25a of the outer convex portion 22 of the spacer expander 2,
Side rail pressure-receiving portions 25, 25 that are integrally connected to the upper and lower ends in the circumferential direction and are separated from at least the connecting member 24 by press punching or the like, and have projecting portions 25b, 25b that equally project on both sides of the outer convex portion. Has been formed. With this configuration, the pressure receiving area with the side rail can be increased, the surface pressure distribution on the upper and lower surfaces of the ring groove 61 of the piston by the side rail can be uniformly maintained, and a sufficient upper and lower surface sealing effect can be obtained. Further, the followability of the oil ring to the cylinder is improved, and the consumption of lubricating oil can be reduced. More preferably, the side rail pressure receiving surface 25 including the upper and lower ends 25a of the outer convex portion and the protruding portion 25b is formed so as to be located on the same circumference over the entire circumference of the spacer expander as shown in FIG. As a result, a more even upper and lower surface pressure distribution can be obtained, and the sealing effect is further improved.

In the conventional spacer expander shown in FIG. 4,
The pressure receiving surface 2 around the entire circumference of the spacer expander
The sum of the circumferential lengths of 21 is set to about 15 to 20% of the total circumferential length on the pressure receiving surface of the combined oil ring,
At least 30% in the side rail pressure receiving portion of the present invention
As described above, it is possible to make the pressure receiving area larger than in the conventional case by setting as described above, prevent the undulation in the axial direction of the side rail during use, and obtain a uniform surface pressure distribution.
The length can be freely set without being restricted by the shape as in the conventional case. In addition, in the said protrusion part, it is necessary to provide a clearance so that adjacent protrusion parts may not interfere during use.

Further, as shown in FIG. 1, in the structure of the combined oil ring of the present invention, the space 241 which is formed by separating from the connecting member of the spacer expander and providing the projecting portion 25b in the circumferential direction serves as an oil circulation hole. As shown in FIG. 2 of the related art, the oil circulation hole 23
Although the step of punching with a punch can be omitted, an oil passage hole may be separately provided depending on the model depending on the case.

The length of the protruding portion of the side rail pressure-receiving portion 25, the axial width, and the like are determined according to the strength of the spacer expander and other necessary conditions. Further, in the spacer expander of the present invention, as the above-mentioned embodiment, in FIG. 3, the case where the protruding portion is projected to both sides in the circumferential direction from the upper and lower ends of the outer protruding portion has been described. Although it is possible to obtain a better effect than before by projecting either one of the ends or only one side in the circumferential direction from the outer convex portion, the one in the embodiment shown in FIG. 3 exhibits the most desirable and excellent effect. Is.

<Effects of the Invention> As described above, according to the present invention, the spacer expander is formed with the side rail pressure-receiving portion capable of increasing the pressure-receiving area by several steps as compared with the conventional one. It is possible to prevent waviness in the rail axial direction, obtain an even pressure distribution on the upper and lower surfaces, and exert a sufficient sealing effect on the upper and lower surfaces. Further, the followability of the oil ring to the cylinder is improved, the consumption of lubricating oil can be reduced, and the actual profit of the implementation is extremely large.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which the combined oil ring of the present invention is installed in an oil ring groove of a piston, FIG. 2 is a plan view of a spacer expander of the combined oil ring of FIG. 1, and FIG. FIG. 4 is a partially cutaway perspective view showing an embodiment of the invention, FIG. 4 is a partially cutaway perspective view of a spacer expander of a conventional combined oil ring, and FIG. 5 is a conventional combined oil ring mounted in an oil ring groove of a piston. It is sectional drawing which shows the state. Reference numerals in the drawing are: 1 ... Combination oil ring, 2 ... Spacer expander, 21 ... Inner convex part, 22 ... Outer convex part, 24 ... Connecting member, 211 ... Projection, 25 ... Side rail pressure receiving part, 25a ... Outer convex part The upper and lower ends in the axial direction, 25b ... Protrusions, 3 ... Side rails, 4 ... Cylinder inner wall, 5 ... Inside of side rails, outer peripheral surface, 6 ... Piston, respectively.

Claims (4)

[Claims] 1. A corrugated flat plate as a whole, the corrugations alternately comprising a series of outer convex portions and a series of inner convex portions, both convex portions being connected by a radially extending connecting member. A combination oil ring consisting of a spacer expander provided with projections on the upper and lower ends in the axial direction of the inner convex portion and a pair of side rails arranged above and below the spacer expander, At least one of the upper and lower ends in the axial direction of the outer convex portion of the spacer expander, and a protruding portion integrally connected to at least one of the upper and lower ends in the circumferential direction and separated from at least the connecting member. A combined oil ring characterized by forming a side rail pressure receiving portion. 2. In the combined oil ring, an axial upper and lower end of an outer convex portion of the spacer expander and a projecting portion which is integrally connected to the upper and lower end in the circumferential direction and is separated from at least the connecting member. The combined oil ring according to claim 1, characterized in that the side rail pressure receiving portion is formed. 3. The combined oil ring according to claim 1, wherein in the combined oil ring, the protrusions protrude on both sides of the outer protrusion in the circumferential direction. 4. The combined oil ring according to claim 1, wherein in the combined oil ring, the side rail pressure receiving portions are located on the same circumference over the entire circumference of the spacer expander.