JPS6326463A - Combined oil ring - Google Patents

Abstract

PURPOSE:To improve a sealing property, by providing a ring-shaped spacer expander comprising a bottom base portion, an outer circumferential mountain portion and an outer circumferential mountain portion, defining a multiplicity of slits thereon and supporting a side rail by the outer and inner mountain portions. CONSTITUTION:An expander 11 comprises an outer circumferential mountain portion 13 and an inner circumferential mountain portion 14 integrally connected to a bottom base portion 12 and a multiplicity of slits 15. The inner circumferential mountain portion 14 is higher than the outer circumferential mountain portion 13 in an axial direction by a width approximately identical with a thickness of a side rail 10. The outer circumferential mountain portion 13 holds the side rail 10 in a proper posture so that the inner circumferential mountain portion 14 applies an effective force to a cylinder. With the arrangement, a sealing property on an groove of a piston ring can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a combination oil ring used by being attached to an outer circumferential groove of a piston of an internal combustion engine.

[Prior Art] The combination oil ring of the present invention is a so-called two-piece type combination oil ring consisting of one spacer expander (hereinafter abbreviated as expander) and one side rail. As a conventional technology for this two-piece type combination piston ring, JP-A No. 52'-1227
There are No. 13 and Utility Model No. 55-41502. However, in JP-A No. 52-122713, the support force of the expander against the inner circumference of the side rail is weak, and therefore the stability of the side rail is poor.
In No. 1, the stability of the side rails was similarly poor, and worse problems were the stability of the expander and the sealing performance of the lower surface of the ring groove.

[Problems to be Solved by the Invention] The present invention attempts to solve the problems of the prior art described above, that is, to obtain good sealing performance with only one side rail and one expander. , provides stable support for the expander's side rail, and maintains good sealing performance by keeping the outer surface pressure of the side rail constant over the entire circumference, and maintains stable posture of the side rail and expander. It aims to solve problems such as:

[Means for Solving the Problems] In order to solve the above problems, the features of the present invention provide a two-piece combination oil ring each consisting of one side rail and one spacer expander. The spacer expander is an annular body consisting of a base part in contact with the lower surface of the piston ring groove, an outer ridge part integrally connected at the outer periphery of the base part, and an inner periphery crest part integrally connected at the inner periphery of the base part. The outer and inner ridges of such a spacer expander have a larger axial width in the inner ridge than the outer ridge, and have a large number of slits extending radially alternately from the outer and inner peripheries. The purpose is to support the flat surface and inner circumferential surface of the flat plate-shaped side rail.

[Example] The combination oil ring of the present invention will be described based on an example shown in the drawings.

FIG. 1 shows a partial perspective view of a combination oil ring that is one of the embodiments of the present invention. Flat side rail (10)
Both the expander (11) and the expander (11) are formed in an annular shape as a whole, and have an abutment separated at one place, similar to a normal piston ring.

The components of the expander (11) include an outer ridge (13) and an inner ridge (14) that are integrally connected to the base (12).
) and a large number of slits (15).

The base portion (12) forms the base of the Okayama portions (13) and (14) and stabilizes the posture of the expander (11) itself within the piston ring groove.

The outer ridge (13) and the inner ridge (14) each have a base (
12) are integrally connected from the outer and inner circumferences of the side rails (12), and the inner circumferential peaks (14) are higher in the axial direction than the outer circumferential peaks (13) by approximately the same thickness as the side rail (10). has been done.

The slit (15), whose widths on both the inner and outer circumferences account for approximately 10% of the total circumference of the expander (11), is essential for bending the entire expander in an annular shape, and also increases the elasticity of the expander. The presence of these slits (15) improves the flexibility and ability to follow the waviness of the piston ring groove or the deformation of the inner circumferential surface of the cylinder. These also have a 1 ohm section as an oil passage.

FIG. 2 is a longitudinal cross-sectional view showing the side rail (10) placed on the expander (11) with the oil ring combined with the present invention installed in the piston sill groove (21). The side rail (10) is placed on the expander (11), and the inner peripheral edge of the side rail (10) is in contact with the outer slope (141) of the inner peripheral peak (14) of the expander (11). The bottom surface of the side rail (10) is the outer ridge (1
It is supported by contacting the flat surface (131) of 3). As described above, the flat surface (131) of the outer peripheral peak (13) allows the side rail to be held more stably.

As mentioned above, the width of the slit (15) is about 10% of the entire circumference of the expander on both the inner and outer circumferences, and the width of the slit (15) is about 10% of the entire circumference of the expander.
0) and the surface pressure on the upper surface of the piston ring groove (21) are made uniform over the entire circumference, and the wear of the expander (11) is also reduced.

The inner peripheral peak (14) of the expander acts to press against the upper surface of the piston ring groove and the inner wall of the cylinder (30). Inner peripheral peak (14) where the inner peripheral edge of the side rail (10) touches
) has an inclined surface (141) facing radially outward;
This results in an even better effect. The outer ridges (13) of the expander hold the side rail (10) in the correct position and the inner ridges (14) of the expander enable a pushing force towards the cylinder (30) - these allow the piston to The sealing property of the upper surface of the ring groove (21) is improved, and the lubricating oil between the inner wall of the cylinder (30) and the piston ring (20) is scraped off by the side rail (10). The scraped lubricating oil directly descends and returns to the oil pan, but a portion passes through the slit (15) and the oil return hole (22), and is also returned to the oil pan.

An outer ridge (13) integrally connected to the base (12)
The expander (11) consisting of the inner peripheral mountain part (14) is
It can be manufactured from a steel material that is integrally formed by drawing bale processing, rolling processing, etc., and is preferable in terms of manufacturing.

[Effects of the Invention] As described above, the combination oil ring of the present invention has the following effects. In other words, (1) By increasing the portion of the expander that supports the side rail, the surface pressure on the outer circumferential surface of the side rail and the surface pressure on the upper surface of the piston ring groove can be made uniform over the entire circumference, and wear on the expander itself can be reduced. .

(2) The base of the expander allows the expander itself and the side rail to maintain their posture stably.

(3) By reducing the number of side rails to one, the sliding frictional force with the cylinder is reduced.

(4) The radial slit improves the elasticity of the expander and the ability to follow the undulations of the ring groove, and also ensures an oil passage.

(5) The side rail is pressed against the upper surface of the ring groove and the inner wall of the cylinder by the outer circumferential peak and inner circumferential peak of the expander, resulting in good sealing performance.

(6) A lightweight piston can be manufactured by making the entire combined oil ring thinner in the axial direction.

(7) The expander can be manufactured from integrally molded steel material, which is advantageous in terms of production.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a combination oil ring according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing a state in which the combination oil ring of the present invention is mounted on a piston. Explanation of symbols 10...Side rail 11...Spacer expander 12...Base portion 13...Outer circumference peak 14...Inner circumference peak 15...Slit 20...Piston 21... Piston ring groove 30...Cylinder liner

Claims (4)

[Claims] (1) In a two-piece combination oil ring each consisting of one side rail and a spacer expander, the spacer expander is integrally connected to the base portion in contact with the lower surface of the piston ring groove and the outer periphery of the base portion. An annular body consisting of an outer circumferential peak and an inner circumferential peak integrally connected at the inner periphery of the base, and the inner circumferential peak has a larger axial width than the outer circumferential peak, and the outer and inner circumferential A combination oil characterized in that the spacer expander has a large number of slits extending in the radial direction alternately, and the flat surface and inner peripheral surface of a flat side rail are supported by the outer and inner peripheral peaks of the spacer expander. ring. (2) Claim 1, wherein the spacer expander is made of integrally molded steel material.
Combination oil ring as described in section. (3) The combination oil ring according to claim 1, wherein the outer circumferential peak portion of the spacer expander that supports the flat surface of the side rail has a flat surface. (4) The combination oil ring according to claim 1, wherein the inner circumferential crest of the spacer expander that contacts the inner circumferential surface of the side rail has a radially outwardly inclined surface. .