JPS6347638Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the structure of an oil ring attached to the piston of a reciprocating engine, and in particular, it is capable of supplying sufficient lubricating oil to the contact surface between the compression ring and the cylinder during initial wear. The present invention relates to an oil ring structure.

Conventionally, in a reciprocating internal combustion engine, a piston b reciprocates within a cylinder a, as shown in FIG.
In order to prevent oil for cooling and lubrication from entering the combustion chamber e, a high-pressure oil ring c is provided in an oil ring mounting groove h on the outer periphery of the piston b, and the lubricating oil passing through the oil ring c is is supplied to the compression ring d.

However, in such conventional means, since the sliding surface f of the oil ring c with respect to the cylinder a is formed to have the same diameter in the sliding direction of the piston b, the oil ring c is provided closer to the combustion chamber e than the oil ring c. There is a problem in that the compression ring d is not sufficiently supplied with lubricating oil for the engine.

In particular, when the engine is new (i.e., the engine has not been sufficiently rubbed), which requires lubricating oil, the lubricating oil is not sufficiently supplied, and the contact surface g between compression ring d and cylinder a
At the time of initial wear, the contact surface g lacks lubricating oil, which tends to cause metal-to-metal contact, resulting in abnormal wear.

Furthermore, if the contact surface g of the ring d and the liner of the cylinder a becomes rough due to this abnormal wear, it becomes difficult to form a normal sliding surface, resulting in the problem of worsening consumption of lubricating oil over a long period of time.

To solve this problem, it is possible to lower the pressure at which the oil ring c rubs together in order to increase the amount of lubricating oil supplied to the oil ring c, but such a low-pressure oil ring has a high pressure The disadvantage is that it consumes more lubricating oil than the conventional oil ring.

The present invention aims to solve these problems by efficiently supplying lubricating oil to the compression ring, preventing abnormal wear of the compression ring, and reducing lubricating oil consumption. It is an object of the present invention to provide an oil ring structure capable of reducing the amount of oil.

For this reason, the oil ring structure of the present invention has two rail-shaped protrusions on the outer circumferential surface of the main body that fit into the oil ring mounting groove formed on the outer circumference of the piston that reciprocates within the cylinder of the engine. In addition, in the oil ring that adjusts the amount of oil supplied to the compression ring that is mounted on the outer periphery of the piston closer to the combustion chamber than the oil ring mounting groove, a groove is attached to the inner wall of the cylinder on the peripheral end surface of each of the protrusions. A sliding surface that can come into contact is formed, and the sliding surface has a tapered shape whose diameter gradually decreases in a direction away from the combustion chamber, and the tapered shape is maintained during the initial period of break-in of the engine. It is characterized in that it contacts the inner wall of the cylinder, and the contact portion is worn during the break-in operation, so that the tapered shape of the sliding surface disappears.

The structure of an oil ring as an embodiment of the present invention will be explained below with reference to the drawings. Figures 2 and 3 are cross-sectional views showing the state before and after initial wear when installed in the cylinder, and Figure 4 is a cross-sectional view of the oil ring installed in the cylinder. FIG. 5 is an enlarged cross-sectional view of the portion shown in FIG. 3;

As shown in FIG. 2, an oil ring 3 is provided that can fit into an oil ring mounting groove 2b formed on the outer periphery 2a of a piston 2 that can reciprocate within a cylinder 1 of the engine. A compression ring 4 is attached to the outer periphery 2a closer to the combustion chamber 5 than the ring 3.

Further, the outer circumferential surface of the oil ring 3 is provided with two rail-shaped protrusions, and sliding surfaces 3a, 3a that can come into contact with the cylinder 1 are formed on the respective peripheral end surfaces of the protrusions.

Sliding surface 3 of oil ring 3 against cylinder 1
When the engine is new, as shown in FIG.
The inclination angle θ is about 1 degree with respect to the inner surface of the plate, and the gap D is 3 to 5 μm.

Therefore, when the contact surface 4a between the compression ring 4 and the cylinder 1 is not sufficiently rubbed together, lubricating oil passes through the oil ring 3 and is sufficiently supplied to the contact surface 4a. .

As shown in Fig. 3, when the break-in operation of this engine is completed and the contact surface 4a between the compression ring 4 and the cylinder 1 wears out normally, a sliding surface 4b is formed and the supply of lubricating oil is interrupted. At the very least, the ring 4 and the cylinder 1 can slide without any trouble.

During the initial wear of the contact surface 4a, the wear of the sliding surface 3a of the ring 3 accelerates, and as shown in FIGS. 3 and 5, the surface becomes parallel to the surface 3b, and the taper disappears. However, only a small amount of lubricating oil is supplied to the compression ring 4.

As detailed above, the oil ring structure of the present invention has a simple structure in which the sliding surface of the oil ring relative to the cylinder is formed in a tapered shape whose diameter gradually decreases in the direction away from the combustion chamber.
During the initial wear of the contact surface between the compression ring and the cylinder, there is an advantage that oil can be actively pumped up to this contact surface, and by the time the compression ring has been rubbed together at the end of the initial wear, the lubricating oil is compressed. In addition to preventing excessive supply of oil to the tension ring, it also enables the smooth operation of the high-pressure oil ring, which has the advantage of contributing to improved engine performance and reducing oil consumption. There is.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional oil ring structure, Figs. 2 to 5 show an oil ring structure as an embodiment of the present invention, and Figs. 4 is an enlarged sectional view of the portion shown in FIG. 2, and FIG. 5 is an enlarged sectional view of the portion shown in FIG. 3. 1... Cylinder, 2... Piston, 2a... Outer periphery, 2b... Oil ring mounting groove, 3... Oil ring, 3a... Sliding surface, 3b... Parallel surface, 4
...compression ring, 4a...contact surface,
4b...Slip surface, 5...Combustion chamber.

Claims (1)

[Scope of utility model registration request] It has two rail-shaped protrusions on the outer circumferential surface of the main body that fit into the oil ring mounting groove formed on the outer periphery of the piston that reciprocates within the cylinder of the engine, and the combustion chamber In an oil ring that adjusts the amount of oil supplied to a compression ring mounted on the outer periphery of a nearby piston, a sliding surface that can come into contact with the inner wall of the cylinder is formed on the peripheral end surface of each of the protrusions, and the same The sliding surface has a tapered shape that gradually reduces in diameter in the direction away from the combustion chamber, and during the initial period of break-in of the engine, the tapered shape is maintained and comes into contact with the inner wall of the cylinder, and during the break-in operation. 1. An oil ring structure characterized in that the tapered shape of the sliding surface disappears due to abrasion of the contact portion therein.