JPS6114604Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotation prevention device for a combination oil ring provided on a piston of an engine.

The combination oil ring includes a ring-shaped upper side rail and a lower side rail, and an expander that applies force to the upper side rail and the lower side rail, and is inserted into an annular groove formed on the outer circumferential surface of the piston. has been done. Although the oil consumption of the engine has been significantly improved by adopting such a combination oil ring, in some cases, especially when the engine is decelerating, the oil consumption still remains high.

The aim of the invention is to provide a combination oil ring that can further improve oil consumption.

The upper side rail and the lower side rail have an abutment (notch) in a part of the annular shape to allow insertion of the piston into the annular groove. The upper side rail and the lower side rail do not remain stationary during the up and down movement of the piston, but rotate in the circumferential direction. Particularly during deceleration, the pressure in the combustion chamber decreases, so this rotational speed tends to be high. Therefore, when the upper and lower side rails cause relative sliding and the positions of their abutments in the circumferential direction substantially coincide, oil leaks through the coincident abutments.

According to the present invention, the relative rotational movement between the upper side rail and the lower side rail is restricted so that the abutments of the upper and lower side rails do not coincide.

Next, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is a cylinder and 2 is a piston. An annular groove 3 is formed on the outer peripheral surface of the piston 2. A combination oil ring comprising an upper side rail 4, a lower side rail 5, and an expander 6 is inserted into the annular groove 3. The rail pressing parts 7 and 8 of the expander 6 have the role of pressing both the upper side rail 4 and the lower side rail 5 toward the inner wall of the cylinder 1, and also press the upper side rail 4 against the upper wall of the annular groove 3. and the lower side rail 5 toward the lower wall of the annular groove 3. Expander 6
has protrusions 9 and 10 on the upper and lower sides of the outer periphery. Second
As shown in the figure, recesses 11 and protrusions 12 are alternately formed on the inner peripheral edges of the side rails 4 and 5. The rail holding parts 7 and 8 mentioned above are in contact with the recesses 11 of the side rails 4 and 5. With respect to the circumferential length b of the rail holding parts 7 and 8, the recess 11
The circumferential length a of is specified to be a slightly larger value. FIG. 3 is a perspective view of the oil ring taken out from the annular groove 3. In FIG. 3, direction A is radially outward, and direction B is radially inward. In assembling the combination oil ring, the circumferential position of the abutment between the upper side rail 4 and the lower side rail 5 is offset by an appropriate value (for example, 90 degrees).

During the vertical movement of the piston 2, the upper side rail 4, lower side rail 5, and expander 6
attempts to rotate each separately. However, the protrusions 12 of the side rails 4 and 5 come into contact with the side edges of the rail pressers 7 and 8 as stoppers that limit the relative rotation of the rail pressers 7 and 8 as protrusions.
Mutually independent rotation of the side rails 4, 5 is prevented. That is, the side rails 4, 5 and the expander 6 rotate integrally while the relative angular positions of the upper side rail 4 and the lower side rail 5 are always held constant. Therefore, the positions of the abutments between the upper side rails 4 and the lower side rails 5 are prevented from coinciding in the circumferential direction.

Figures 4 and 5 show other embodiments of the invention. Portions corresponding to those in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted. In this embodiment, the inner peripheral edges of the side rails 4, 5 are formed in a circular shape. Grooves 15 are formed in the upper and lower surfaces of the side rails 4 and 5 in correspondence with the protrusions 9 and 10. Considering the convenience of assembling the side rails 4 and 5, grooves 15 are provided on both the upper and lower sides of the side rails 4 and 5 so that all the side rails can be used for both the upper and lower side rails. Although it is formed in
The groove 5 only needs to be formed on the lower surface of the upper side rail 4 and the upper surface of the lower side rail 5.
The groove 15 extends from the inner circumferential edge of the side rails 4, 5 toward the outer circumferential edge by a predetermined distance. As shown in FIG. 5, the circumferential width c of the groove 15 is set to be slightly larger than the circumferential length d of the protrusions 9 and 10. The protrusions 9, 10 extend into the groove 15 and abut against the bottom surface of the groove 5;
It functions as a stopper to limit the relative rotation of.
In assembling the combined oil ring, the circumferential position of the abutment between the side rails 4 and 5 is offset by an appropriate amount.

Grooves 15 and protrusions 9, 10 of side rails 4, 5
Due to the contact between the side rails 4 and 5, independent rotation of the side rails 4 and 5 is prevented, and the relative difference in the circumferential position of the abutment of the side rails 4 and 5 is maintained constant. The expander 6 rotates integrally.

As described above, according to the present invention, the protrusion provided on the expander and protruding toward the upper side rail and the lower side rail, and the protrusion provided on the upper side rail and the lower side rail protruding in the circumferential direction of the annular groove. Since the relative rotation between the expander and the upper side rail and the lower side rail is restricted by the stopper that comes into contact with the upper side rail, the abutments of the upper side rail and the lower side rail are at the same position in the circumferential direction. As a result, oil consumption can be suppressed.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and a second embodiment of the invention is shown in FIG.
2 is a plan view of the combined oil ring shown in FIG. 1, FIG. 3 is a perspective view of the combined oil ring shown in FIG. 1, and FIG. 4 is another embodiment of the present invention. 5, and FIG. 5 is a plan view of the combination oil ring of FIG. 4. 2... Piston, 3... Annular groove, 4... Upper side rail, 5... Lower side rail, 6...
Expander, 7, 8...Rail holding part, 9, 1
0...Protrusion, 12...Protrusion, 15...Groove.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A combination oil ring structure that is inserted into an annular groove provided on the outer circumferential surface of a piston for an internal combustion engine and that sandwiches an expander between an upper side rail and a lower side rail. The expander is provided with a protrusion that protrudes toward the pass side rail and the lower side rail, and the top side rail and the lower side rail are provided with a stopper that contacts the protrusion in the circumferential direction of the annular groove. A rotation prevention device for a combination oil ring. 2. The protrusion is a rail holding part that presses down the inner peripheral edge of the upper side rail and the lower side rail, and the stopper is a convex part that protrudes radially inward and comes into contact with the side edge of the rail holding part. A detent device according to claim 1, which is a utility model. 3. The protrusion is a protrusion that protrudes toward the upper side rail and the lower side rail on the outer peripheral side of the expander, and the stopper is a groove into which the protrusion is inserted. A detent device according to claim 1 of the utility model registration claim.