JP2001527197A - Improved piston ring - Google Patents

Abstract

(57) Abstract: Provided is a structure of a piston ring (1, 1a) formed with a gap (6, 6a) to be disposed in each of annular ring receiving grooves (4) formed in an internal combustion engine piston. I do. Each end (2, 3; 2a, 3a) of the piston ring (1, 1a) is formed with a width smaller than the width dimension (b) of the piston ring (1, 1a), and these ends (2, 3a) are formed. 3; 2a, 3a) are arranged in an overlapping relationship with each other, in which case the first end (2, 2a) is in contact with the inner surface of the second end (3, 3a) and the piston ring groove (4). ), The second end (3, 3a) extends outside the first end (2, 2a), and the end surface (5, 5a) of the second end. A gap (6, 6a) of the ring is formed between the first end portion (2, 2a) and the transition region where the first end portion (2, 2a) is sufficiently widened.

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD [0001] The present invention relates to a piston ring having a gap formed therein, and more particularly to a piston ring disposed in an individual annular ring receiving groove formed in an internal combustion engine piston.

BACKGROUND ART [0002] Each piston ring has the form of an open ring, with some kind of slit connection provided between both ends of the ring to make the ring elastic. I have. If the slit is open and a gap is formed, a small amount of combustion gas will pass through the gap during operation of the engine piston. The passage of small amounts of combustion gases through this gap can be tolerated, especially in the uppermost piston ring. This is because the pressure on this piston ring is consequently reduced, greatly reducing the fatigue on said piston ring.

[0003] However, a major disadvantage associated with this is that the hot combustion gases spread into the annular groove of the piston, pass along the inner surface of the piston ring and flow out through this gap in the ring. . This flow of hot gas causes the piston ring to be heated to an unfavorable degree, and furthermore, the annular groove gradually carburizes, requiring frequent engine repairs and replacement of the piston ring. And let

[0004] In order to reduce the gas passage through such a piston ring, and to eliminate it as completely as possible, piston rings with an airtight connection have been proposed. A piston ring of this kind is disclosed in EP 742875. According to this patent publication, both ends of the piston ring are designed to overlap, with one end extending over the other and bridging between the ends of the piston ring. I have to. The disadvantage of this construction is that, if the piston ring of this shape is located closest to the combustion chamber on the piston on which the piston rings are mounted, as described above, this piston ring will That is, it must absorb the pressure drop, and therefore must absorb the entire load in each explosion stroke. As a result, fatigue increases on the ring and the inner wall of the engine cylinder.

In order to somewhat reduce the pressure on the most exposed of the piston ring, it is proposed in this European patent that the piston ring has several passages for the passage of combustion gases. I have. These passages are arranged around the ring at equal distances to the fatigue surface. This solution is operationally advantageous because it somewhat reduces the load on the most exposed piston ring. However, at the same time, this solution causes other disadvantages. That is, these passages will act as a means to induce significant cracking throughout the ring. Further, in the case of a piston ring provided with a surface coating layer having a hard and brittle plasma-sprayed wear layer, damage from the oxide layer (scaling) of the wear layer may be caused by damage to the passage. It is likely to occur during formation and during subsequent operations. The risk of this failure occurring is most likely when these passages are straight. That is, in the case of a passage extending perpendicularly from the top surface to the bottom surface of the piston ring, the possibility of this breakage is high. If the passage extends diagonally, the greatest danger of this oxide layer will be at the top and bottom of the passage, as in the European patent. This is a serious drawback in the piston ring and this oxide layer also causes serious damage to the inner wall of the cylinder.

An object of the present invention is to provide an apparatus that can solve the above-described problems. Further, such features of the present invention can be clearly inferred from the claims and the like.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail with reference to the accompanying drawings. The piston ring 1 according to the present invention has a shape with two ends 2, 3,
The width of the ends 2 and 3 is smaller than the width b of the piston ring 1. These ends 2 and 3 overlap and overlap with the first end 2 being sandwiched between the inner surface of the second end 3 and the bottom surface of the piston ring groove 4 for receiving the piston ring 1. I'm wrapping. Accordingly, the second end 3 extends outwardly or in front of the first end 2. The gap 6 is formed between the end face 5 of the second end 3 and the transition region where the first end 2 is fully extended.

[0008] This configuration of the piston ring 1 has several advantages over the prior art. That is, only a small amount of the high-temperature combustion gas can enter the annular groove 4 on the upper surface and the rear surface of the piston ring 1 and stay there. Gas flow along the inner surface of the piston ring 1, which may cause harmful heating of the piston ring 1 or cause carburization of the annular groove 4, can be prevented. At the same time, in contrast to conventional overlapping joints, this ring gap 6 allows the passage of small amounts of combustion gases, thereby reducing said pressure on the piston ring 1. Yet another advantage is that
A surface coating 7 can be applied to the piston ring 1, which can be done without interfering with the above technology.

FIG. 4 shows a modification of the embodiment shown in FIG. 3. In this case, each end 2 a, 3
Each of the end surfaces 5a and 8a of FIG. a is obliquely inclined when viewed from the circumferential direction of the piston ring 1a. Therefore, as shown in FIG. 4, an oblique gap 6a is formed in the piston ring.

[0010] The present invention is not limited to the illustrated embodiment, but can be variously modified and improved within the scope of the claims.

[Brief description of the drawings]

FIG. 1 is a plan view of a piston ring according to the present invention.

FIG. 2 is a partial longitudinal sectional view of a piston on which a pair of piston rings is mounted.

FIG. 3 is an enlarged perspective view showing a coupling portion of a piston ring according to the present invention.

FIG. 4 is an enlarged perspective view showing a connecting portion of a piston ring different from that of FIG. 3;

Claims (2)

[Claims] A gap (6, 6) extending across the ring from the upper surface to the lower surface.
a) forming a piston ring (1, 1a), each of which is disposed in an annular ring receiving groove (4) formed in an internal combustion engine piston; Each end (2, 3; 2a, 3a) of 1a) is formed with a width smaller than the width (b) of the piston ring (1, 1a), and each end (2, 3; 2a) is formed. , 3a) are arranged in an overlapping relationship with each other, in which case the first end (2, 2a) has the inner surface of the second end (3, 3a) and the bottom surface of the piston ring groove (4). And the second end (3, 3a) is connected to the first end.
, The tip end surface (5, 5a) of the second end portion and the first end portion (2, 2a) are extended with a sufficient width. A piston ring, wherein a gap (6, 6a) of the ring is formed between the piston ring and a region. 2. The end surface (5a, 8a) of each end (2a, 3a) is inclined obliquely when viewed from the circumferential direction of the piston ring (1a). The piston ring according to 1.