JPH09317885A - Combination oil ring detente structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the mountability of an oil ring to a piston and the sealing between its upper and lower faces and the side walls of a ring groove, and keep its detent function even if a detent member is dislocated. SOLUTION: A combination oil ring 10 comprises a sectionally substantial I-shaped oil ring 11 constituted by a pair of rails 13 and 14 coupled together by a column 15, and a coil expander 12. The oil ring 11 is formed at its lower face 11a with a recessed part 30 which is open to its outer periphery and to which a detent member 31 is fixed to be inserted into a recessed part 32 formed in a lower plane 4a of an oil ring groove 4. The detent member receiving recessed part 32 is formed in an outer periphery 3 of a piston 1, and radially extends to the substantial same position as the radially inner end of the detent member fixing recessed part 30. The detent member fixing recessed part 30 may be of a hole shape or may be formed in the inner or outer periphery of the oil ring 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detent structure for a combined oil ring of an internal combustion engine.

[0002]

2. Description of the Related Art A port hole is opened on the inner peripheral surface of a cylinder of a two-cycle engine. When the ring rotates in the circumferential direction and the abutment is aligned with the port hole position, the ring abutment projects outward by self-tension. When the ring moves up and down in this state, the abutment end may be caught in the port hole.

Further, in an engine having a cylinder axis inclined horizontally or nearly horizontally, when the ring rotates and the abutment is located below, lubricating oil penetrates into the combustion chamber through the abutment while the engine is stopped. When the engine is started in this state, white smoke is generated and the consumption of lubricating oil is increased.

By rotating the ring in the circumferential direction,
Due to the above-mentioned problems, the ring rotation preventing means may be adopted.

The situation in which a ring detent is adopted in various engines is as follows.・ Ring detents are not generally adopted for construction machinery and ship diesel engines that are rarely started and stopped. -Of the gasoline engines for automobiles that often start and stop,
In an engine where the cylinder axis is tilted horizontally or nearly horizontally,
Ring detents are commonly used.・ Diesel engines with horizontal or near-horizontal cylinders were rarely used for automobiles in the past, so ring detents were not adopted, but recently this type of engine was used for automobiles. It has come to be used.

The following technique is known as a detent for a combined oil ring. (1) Japanese Utility Model Laid-Open No. 4-50759 According to this technology, a part of the engaging piece is bent in the axial direction so that the outer peripheral contact surface is secured at the abutment end of the side rail of the three-piece combination oil ring. A recess is formed on the side surface of the oil ring groove of the piston. (2) Japanese Utility Model Publication No. 56-9879 This technology is a three-piece combination oil ring consisting of a spacer expander bent in a wavy shape in the axial direction and two upper and lower side rails with a rotation stop structure added. . That is, at the abutment end of the side rail, a part is bent in the axial direction so as to secure the outer peripheral abutment surface to form a locking piece, which is inserted into the space of the valley portion of the spacer expander, and further, the knock pin. Is projected radially outward from the bottom surface of the oil ring groove of the piston into the oil ring groove, and is inserted and arranged in the space of the valley portion of the spacer expander.

[0007]

However, since the above-mentioned rotation preventing structure bends the thin side rail,
There is a problem that the strength of the part is low and the part is easily broken.

An object of the present invention is to provide a combination oil ring detent structure which is easily mounted on a piston. Another object of the present invention is to provide a detent structure for a combined oil ring which has good oil sealability between the upper and lower surfaces of the oil ring and the side surfaces of the ring groove. Still another object of the present invention is to provide a combination oil ring detent structure having a structure capable of maintaining a detent function even when the detent member comes off.

[0009]

SUMMARY OF THE INVENTION According to the present invention, an oil ring having a substantially I-shaped cross section in which a pair of upper and lower rails extending in the circumferential direction are connected by a pillar portion, and an oil ring arranged on the inner peripheral side of the oil ring are provided. A structure for preventing a combination oil ring, which comprises a coil expander that is biased outward in the radial direction, from rotating in the oil ring groove of the piston, wherein the rotation preventing member faces the side surface of the oil ring groove. And a recess into which the anti-rotation member is inserted is formed on the side surface of the oil ring groove so as to open to the outer peripheral surface of the piston.

It is preferable that a recess is formed on the fixing surface of the rotation preventing member of the oil ring, and the rotation preventing member is fixed to the recess. With this configuration, the rotation preventing member can be easily positioned with respect to the oil ring.

The recess for fixing the anti-rotation member of the oil ring is opened to the outer circumference of the oil ring, to the inner and outer circumferences of the oil ring, or is formed in a hole shape of which the periphery is closed. With the hole shape, even if the detent member comes off from the oil ring during operation, the detent member is retained in the recessed portion, so that the detent function can be maintained.

Further, in the case where the rotation preventing member fixing concave portion is closed on the inner peripheral side, the radial inner end of the rotation preventing member inserting concave portion of the oil ring groove is inside the radial direction of the opposed surface of the oil ring. So that it is on the outside of the edge,
It is desirable to secure a contact portion between the oil ring and the side surface of the oil ring groove in order to secure the oil sealability between the oil ring and the side surface of the oil ring groove.

In the above detent structure, the detent member is provided on the oil ring surface facing one side surface of the oil ring groove, that is, on the upper surface side or the lower surface side of the oil ring, or on each side surface of the oil ring groove. It is provided on both sides of the opposing oil ring surfaces, that is, the upper and lower surfaces of the oil ring.

Further, the detent member may be provided at any position in the circumferential direction on the oil ring. For example,
The anti-rotation member is provided near the joint of the oil ring.

Since the detent member provided on the oil ring is inserted into the recess formed on the side surface of the oil ring groove as described above, the movement of the oil ring in the circumferential direction is restricted and the oil ring is It is maintained at a predetermined position in the oil ring groove in the circumferential direction.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to FIG. 1, a rotation preventing structure of a two-piece type combined oil ring according to an embodiment of the present invention will be described.

The piston 1 shown in the figure is for a horizontal engine in which a cylinder 2 is horizontally arranged, and an oil ring groove 4 formed in an outer peripheral surface 3 of the piston 1 in the cylinder 2 is combined with oil. The ring 10 is attached.
The combination oil ring 10 is a two-piece steel combination oil ring, and includes an oil ring 11 and a coil expander 12.

The oil ring 11 is a steel ring having a substantially I-shaped cross section, and has a pair of upper and lower rails 13 extending in the circumferential direction.
14 and a thin straight column portion 15 extending in the circumferential direction and connecting the pair of rails 13 and 14.
The outer peripheral surfaces 16 and 17 of the upper and lower rails 13 and 14 are in contact with the inner peripheral surface 5 of the cylinder 2 to form sliding surfaces for scraping off the oil on the inner peripheral surface 5 of the cylinder 2. Pillar 15 and upper and lower rails 1
The outer peripheral groove 18 formed by the outer peripheral side projections of the rails 3, 14 is an oil receiving groove, and the outer peripheral surface 1 of the upper and lower rails 13, 14 is
The oil scraped off from the inner peripheral surface 5 of the cylinder 2 at 6, 17 passes from the outer peripheral groove 18 through the plurality of oil holes 19 formed in the pillar portion 15 at equal intervals in the circumferential direction. It moves to the inner peripheral side of the ring 11 and is dropped into the oil pan through a plurality of oil escape holes (not shown) formed in the bottom surface 6 of the oil ring groove 4 of the piston 1.

A coil expander 12 is mounted in an inner peripheral groove 20 formed by the protrusions on the inner peripheral side of the upper and lower rails 13 and 14 and the column portion 15, and the oil ring 11 is radially outwardly moved. It is designed to be pressed and urged. The coil expander 12 is formed by winding a wire rod having a circular cross section into a coil shape and grinding the outer peripheral surface of the coil into a ring shape. Therefore, in the drawing, the cross section of the wire is formed in a shape in which the outer peripheral side of the circle is cut out. This ground surface is in contact with the inclined surface of the inner peripheral side protruding portion forming the inner peripheral groove 20 of the oil ring 11. The cross-sectional shape of the wire material forming the coil expander 12 is not limited to that shown above, and may be circular or rectangular, for example.

The oil ring 11 is a coil expander 1.
The outer peripheral surfaces 16 and 17 of the upper and lower rails 13 and 14 are pressed against the inner peripheral surface 5 of the cylinder 2 by being pressed and urged radially outward by 2.

Next, the detent structure will be described. A rotation preventing member fixing recess 30 is formed in the lower surface of the oil ring 11 near one of the abutment ends. The recess 30 has a rectangular shape when viewed from below, is open to the outer circumference of the oil ring 11, and extends in the radial direction from the outer circumference to a position near the inner circumference. That is, the concave portion 30 is formed of a bottom surface and three side wall surfaces, and the lower surface 11a of the oil ring 11 is partially left on the rear surface of the concave portion 30, that is, the inner peripheral side.

The upper surface of the rotation preventing member 31 is fixed to the bottom surface of the recess 30 by means such as welding or adhesion, and is projected below the lower surface 11a of the oil ring 11. The rotation stopping member 31 is a semicircular plate member having a flat upper surface and a lower surface forming an arc surface when viewed in the radial direction.

On the other hand, on the lower side surface 4a of the oil ring groove 4, there is formed a concave portion 32 into which the anti-rotation member 31 is inserted. The recess 32 is a recess having an arcuate cross-section when viewed from the radial direction, and is slightly spaced from the whirl-stop member 31 when the lower surface 11a of the oil ring 11 is in contact with the lower side surface 4a of the oil ring groove 4. The size is such that there is a gap.

The recess 32 opens in the outer peripheral surface 3 of the piston 1 and extends in the radial direction to a position substantially the same as the radial inner end of the recess 30 formed in the lower surface 11a of the oil ring 11. . That is, the concave portion 32 is formed of an arcuate bottom surface and one side wall surface, and the rear surface of the concave portion 32, that is, the inner peripheral side, is the lower side surface 11 a of the oil ring groove 11.
Are mostly left.

Therefore, the lower surface 11a portion of the oil ring 11 on the rear surface side, that is, the inner peripheral side of the rotation preventing member 31, and the lower surface 4a portion of the oil ring groove 4 on the rear surface side of the rotation preventing member insertion recess 32, that is, the inner peripheral side. Therefore, the sealing property between the oil ring 11 and the lower side surface 4a of the oil ring groove 4 is ensured even in the portion of the oil ring 11 where the detent member 31 is provided.

Then, as described above, the oil ring 11
Since the anti-rotation member 31 provided on the lower surface 11a of the oil ring is inserted into the recess 32 formed on the lower side surface 4a of the oil ring groove 4, the anti-rotation member 31 is recessed on the lower side surface 4a of the oil ring groove 4. By engaging the side wall surface of 32, the oil ring 11 is prevented from rotating in the circumferential direction.

FIG. 2 shows another embodiment of the present invention, which is a two-piece type combined oil ring detent structure. The difference from the above embodiment is the oil ring 1.
1 is a concave portion for fixing the anti-rotation member formed on the lower surface 11a. In this embodiment, the anti-rotation member fixing recess 30 is formed in the shape of a hole without being opened in the outer circumference and the inner circumference of the oil ring 11. That is, the anti-rotation member fixing recess 30 has an elongated hole shape in the circumferential direction when viewed from below, and is formed by the bottom surface and the peripheral side wall surface.

According to the present embodiment, even if the whirl-stop member 31 comes off from the oil ring 11 while the engine is running, the whirl-stop member 31 is retained in the recess 30 for fixing the whirl-stop member. Therefore, the whirl-stop function can be maintained.

FIG. 3 shows a rotation preventing structure for a two-piece combination oil ring which is still another embodiment of the present invention. The difference from the above two embodiments is that the lower surface of the oil ring 11 is different. 11a, a recess for fixing the anti-rotation member, and a recess for inserting the anti-rotation member, which is formed on the lower side surface 4a of the oil ring groove 4. In the present embodiment, the anti-rotation member fixing recess 30 has a rectangular shape when viewed from below and is open to the outer circumference and the inner circumference of the oil ring 11. That is, the concave portion 30 is formed by the bottom surface and the two side wall surfaces, and the lower surface 11a of the oil ring 11 is not left on the rear surface of the concave portion 30, that is, the inner peripheral side. Further, the anti-rotation member insertion recess 32 formed on the lower side surface 4a of the oil ring groove 4 extends from the outer peripheral surface 3 of the piston 1 in the radial direction to the position 6 of the bottom surface of the oil ring groove 4. The bottom surface 6 of the piston 4 is partially open and is connected to an oil escape hole 7 formed in the piston 1 so as to communicate therewith.

In this embodiment, the rotation stopping member 31
Although a rectangular flat plate material is used, of course, a plate member having a semicircular cross section as shown in the above embodiment may be used.

Further, in this embodiment, as compared with the above-described two embodiments, the sealing property between the lower surface 11a of the oil ring 11 and the lower side surface 4a of the oil ring groove 4 is provided and the anti-rotation member 31 is provided. It is inferior in that part.

Therefore, the first and second embodiments are configurations in which the side seal between the oil ring and the oil ring groove is considered important, and are used, for example, in a horizontally opposed diesel engine. The third embodiment is a case where the side seal between the oil ring and the oil ring groove may be somewhat inferior, and is used, for example, in a horizontally opposed gasoline engine.

In the first and third embodiments described above, the rotation preventing member fixing recess 30 is formed in the oil ring 11.
The oil ring 1 is formed without forming the recess 30.
It is also possible to directly fix the rotation stopping member 31 to the lower surface 11a of No. 1.

Further, in the above-mentioned three embodiments, the rotation prevention is performed on the lower surface 11a side of the oil ring 11, but the invention is not limited to this. A rotation stopping member is provided on the upper surface 11b side of the oil ring 11, and the upper side surface 4b of the oil ring groove 4 is provided.
Alternatively, the rotation stopper may be formed on the upper surface side of the oil ring 11 by forming a recess for inserting the rotation stopper. Alternatively, detents can be provided on both the lower surface 11a and the upper surface 11b of the oil ring 11.

[0035]

As described above, according to the present invention, it is possible to provide a rotation preventing structure for a combined oil ring which is easily mounted on a piston. Further, it is possible to provide a combination oil ring rotation preventing structure in which the upper and lower surfaces of the oil ring and the side surfaces of the ring groove have good oil sealability. Further, it is possible to provide a combination oil ring rotation preventing structure capable of maintaining the rotation preventing function even when the rotation preventing member comes off.

[Brief description of drawings]

FIG. 1 shows a rotation preventing structure of a two-piece type combined oil ring which is an embodiment of the present invention, and (a) is a vertical cross-sectional view showing a state in which a piston equipped with the combined oil ring is inserted into a cylinder. FIG. 6B is a front view of the combined oil ring portion of the piston (around the abutment portion), and FIG. 7C is a bottom view of the oil ring near the abutment portion.

FIG. 2 is a rotation preventing structure of a two-piece type combined oil ring according to another embodiment of the present invention, in which (a) is a vertical section in a state where a piston having the combined oil ring is inserted into a cylinder. The front view, (b) is a partial cross-sectional front view of the combined oil ring portion (near the joint) of the piston,
(C) is a bottom view of the vicinity of the abutment portion of the oil ring.

FIG. 3 shows a rotation preventing structure of a two-piece type combined oil ring which is still another embodiment of the present invention, in which (a) shows a state in which a piston having the combined oil ring is inserted into a cylinder. A vertical cross-sectional view, (b) is a front view of the combined oil ring portion of the piston (near the joint),
(C) is a bottom view of the vicinity of the abutment portion of the oil ring.

[Explanation of symbols]

 1 Piston 2 Cylinder 3 Piston Outer Surface 4 Oil Ring Groove 4a Oil Ring Groove Lower Side 4b Oil Ring Groove Upper Side 5 Cylinder Inner Surface 6 Oil Ring Groove Bottom 7 Oil Relief Hole 10 Combination Oil Ring 11 Oil Ring 11a Oil Ring Lower surface 11b Oil ring upper surface 12 Coil expander 13, 14 Rail 15 Column portion 16, 17 Outer peripheral surface 18 Outer peripheral groove 19 Oil hole 20 Inner peripheral groove 30 Recessing member fixing recess 31 Rotation preventing member 32 Recessing member inserting recess

Front Page Continuation (72) Inventor Takashi Inoue 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (8)

[Claims] 1. An oil ring having a substantially I-shaped cross section in which a pair of upper and lower rails extending in the circumferential direction are connected by a column portion, and an oil ring arranged on the inner peripheral side of the oil ring and biased outward in the radial direction. A structure that locks the combined oil ring consisting of a coil expander inside the oil ring groove of the piston, and the rotation stop member is fixed to the oil ring surface facing the side surface of the oil ring groove. A detent structure for a combined oil ring, wherein a recess into which a stop member is inserted is formed on a side surface of the oil ring groove so as to open to a piston outer peripheral surface. 2. The combination oil ring according to claim 1, wherein a concave portion is formed on a fixing surface of the rotation preventing member of the oil ring, and the rotation preventing member is fixed to the concave portion. Stop structure. 3. The detent structure for a combined oil ring according to claim 2, wherein the detent for fixing the detent member of the oil ring is open to the outer circumference of the oil ring. 4. The anti-rotation structure for a combined oil ring according to claim 2, wherein the anti-rotation member fixing recess of the oil ring is open to the inner and outer circumferences of the oil ring. 5. The anti-rotation structure for a combined oil ring according to claim 2, wherein the recess for fixing the anti-rotation member of the oil ring has a hole shape whose periphery is closed. 6. The radial inner end of the anti-rotation member insertion recess of the oil ring groove is located outward of the radial inner end of the facing surface of the oil ring. 5. A combination oil ring detent structure according to item 5. 7. The detent for a combined oil ring according to claim 1, wherein the detent member is provided on an oil ring surface facing one side surface of the oil ring groove. Construction. 8. The detent for a combined oil ring according to claim 1, wherein the detent member is provided on an oil ring surface facing each side surface of the oil ring groove. Construction.