JP2737107B2 - Compression ring for internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a compression ring for an internal combustion engine.

BACKGROUND ART With respect to a compression ring used as one type of piston ring for an internal combustion machine, in order to prevent gas leakage or blow-by gas when the piston receives the pressure of the combustion gas, various measures have been taken to improve the sealing performance. Improvements have been made.

One of the improved compression rings is a compression ring having a special abutment. FIG. 3 shows an example of the configuration. In this example, a protruding portion 2 having a right-angled triangular cross section that protrudes in the circumferential direction is formed at an upper outer peripheral end of one abutting end of the compression ring 1, and the above-described outer peripheral end of the other abutting end is formed at the upper outer peripheral end of the other abutting end. A recess 3 having a right-angled triangular cross section capable of receiving the protrusion 2 is formed. When the compression ring 1 is attached to the ring groove 4 of the piston 5 and attached to the cylinder 6, the abutment parts 2 and 3 overlap each other (see US Pat. No. 5,253,878).

In order to cope with recent high-speed and high-load gasoline engines, the toughness of the piston ring has been improved, while the selection of materials satisfying the workability of the piston ring has been attempted. In other words, the selection of the piston ring material is made based on a balance between a material having high strength and a material having low workability. On the other hand, since the material of the piston itself that contains the piston ring is lower in quality than the material of the piston ring, the wear on the side of the ring groove of the piston increases, causing unstable movement in the ring groove of the piston ring. . As a result, breakage of the protruding portion 2 of the double-angle type piston ring 1 shown in FIGS. 3 and 4 is caused, and the engine performance is extremely reduced. This breakage is more likely to occur when an inner cut 7 extending in the circumferential direction is provided at the upper inner corner of the piston ring and the projection 2 having a small cross-sectional area is used.

DISCLOSURE OF THE INVENTION Another means for achieving the same function as an inner cut (see GB2164418A) for improving the side seal of the compression ring (by contact between the ring side wall surface and the ring groove wall surface) has been developed. It is another object of the present invention to solve the problem of the related art by increasing the sectional area of the protruding portion 2 while maintaining the side sealing performance.

In order to solve the above-mentioned problem, the compression ring of the present invention is provided with an annular groove extending in a circumferential direction on an inner peripheral surface thereof.
The center of the groove is located above the center of the ring width.

More specifically, the present invention is configured such that a projecting portion projecting in the circumferential direction is formed at an upper outer corner of one of the abutting ends, and the projecting portion is received at an upper outer corner of the other abutting end. In a compression ring for an internal combustion engine having an abutment in which a possible recess is formed, a center line of the groove becomes straight when a groove located above the center of its width is developed on the inner peripheral surface of the compression ring. A compression ring for an internal combustion engine, wherein the groove extends in the circumferential direction so as not to make the upper surface of the compression ring a constituent element. I will provide a.

Preferably, a plurality of grooves are provided and the cross section is semicircular.

Since the upper inner peripheral corner of the press-fit portion at the end of the compression ring is brought to the inner peripheral side of the ring, the cross-sectional area of the protrusion is increased,
The breakage can be prevented. Side sealing due to ring torsion is maintained with the compression ring of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing the configuration of the vicinity of an abutment portion and a groove of a compression ring according to an example of the present invention.

FIG. 2 is a cross-sectional view showing a configuration near an abutment portion of a compression ring according to another example of the present invention.

FIG. 3 is a perspective view of a configuration near a portion of a conventional compression ring.

FIG. 4 is a sectional view showing a part of an engine provided with a conventional piston ring.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration near an abutment portion of a compression ring as a first embodiment of the present invention. The configuration of the joint is a special joint of a double angle shape, and a projection 12 having a right-angled triangular cross section extending in the circumferential direction is provided at the upper outer corner of one end of the joint of the compression ring 11, and the other joint is provided. The end portion is provided with a concave portion 13 having a shape capable of receiving the protruding portion 12 at the upper outer corner, and is mounted in the ring groove of the piston and fitted in the cylinder as shown in FIG. , Protrusion 12
Is in a state of overlapping with the recess 13.

An inner peripheral surface 16 of the piston ring 11 is provided with a groove 14 having a substantially semicircular cross section and extending in the circumferential direction. The center of the groove 14 is located slightly above the center of the piston ring 11 in the width direction,
Thus, the piston ring 11 is twisted to secure the side seal in the same manner as in the case of the inner cut. That is, when the compression ring 11 is expanded, the center line of the groove 14 becomes a straight line parallel to the width center of the compression ring 11.

Since the inner cut is not provided, the inner edge of the concave surface 13 is brought near the inner corner of the upper ring, and the inner edge of the protrusion 12 is extended to near the inner corner of the ring. Twelve cross-sectional areas can be large.

This fact will be explained with an example. The compression ring having a diameter of 76φ cylinder has a thickness of 3.3 mm and a width of 1.5 mm. When a groove with a depth of 0.5 mm and a height of 0.5 mm is provided on the inner peripheral surface of this compression ring, the cross-sectional area of the protrusion is 1.65 mm ² (thickness or height 3.0 mm × width
1.1 mm x 1/2). When a 0.5 x 0.5 mm triangular inner cut is provided at the upper inner corner of a compression ring of the same dimensions, the cross-sectional area of the protrusion is 1.43 mm ² (thickness or height)
2.6mm x 1.1mm x 1/2), smaller than in this case. That is, in the present case, the cross-sectional area can be increased by 15% as compared with the conventional case.

In the example shown in FIG. 2, two grooves 14, 15 extend in the circumferential direction in parallel with the inner peripheral surface 16 of the piston ring 11. The center of the lower groove 14 is located slightly above the center of the width of the piston ring 11, but the other configuration is the same as that of FIG. That is,
When the compression ring 11 is deployed, the center line of the groove 14 is a straight line parallel to the width center of the compression ring 11.

When the grooves 14 and 15 on the inner peripheral surface of the piston ring 11 are drawn out of the material of the piston ring 11 as a wire, a groove equivalent portion is formed in a mold in advance, and the grooves 14 and 15 are formed simultaneously with the material drawing operation. Good.

The above-mentioned example in which a groove is provided on the inner peripheral surface of the above-described compression ring having a 76φ cylinder diameter (each dimension is as described above) and the conventional example in which an undercut is provided in the inner peripheral corner above the ring are 100%.
As a result of this test (4/4 load 2400 rpm, continuous operation for 200 hours), the side seal effect of both rings without breakage of the protrusion 2 was almost the same, and there was no difference in oil consumption. While there was no breakage of the protruding part 12, several breakages were observed in the conventional example, and the engine performance was significantly deteriorated.

INDUSTRIAL APPLICABILITY According to the present invention, the cross-sectional area of the protruding portion of the piston ring abutment can be made sufficiently large, and the side seal characteristics can be maintained in the same manner as in the case of the inner cut.

Claims (3)

(57) [Claims] A projection is formed at an upper outer corner of one of the abutment ends so as to protrude in the circumferential direction, and a concave portion capable of receiving the projection is formed at an upper outer corner of the other apex end. In a compression ring for an internal combustion engine having a formed abutment, the center line of the groove is straightened when a groove positioned above the center of its width is developed on the inner peripheral surface of the compression ring, and the groove is compressed. A compression ring for an internal combustion engine, wherein an upper surface of the ring is extended in a circumferential direction so as not to be a component. 2. The compression ring according to claim 1, wherein a plurality of grooves are formed in parallel. 3. The compression ring according to claim 2, wherein the cross section of the groove is semicircular.