JPS599069Y2 - Piston ring device for irregularly shaped cylinders - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a ring device for ensuring airtightness between the cylinder and the piston in a cylinder having an irregular cross-sectional shape such as a substantially oval shape.

More specifically, the piston ring that is fitted onto the outer circumferential surface of the piston is formed into a plurality of divided pieces, and a sealing member is slidably incorporated into the piston by positioning it at the end mating part of each divided piece, so that the divided pieces are mutually connected. The present invention relates to a ring device for a piston for an irregularly shaped cylinder, in which the sealing performance of the mating portion is ensured by the sealing member, and the airtightness between the cylinder and the piston is ensured.

In internal combustion engines, compressors, etc., the cross-sectional shape of the cylinder is not circular, but has an irregular shape, such as a substantially oval shape, for example, to improve the filling efficiency of air-fuel mixture with respect to the effective cross-sectional area of the cylinder. It is being done.

Of course, the piston that is slidably fitted into the cylinder is also shaped to have the same irregular cross-sectional shape as the cylinder, but it is extremely difficult to manufacture cylinders and pistons exactly according to the predetermined shape due to their shape. When fitting the cylinder into the cylinder, there will be a slight gap.

For this reason, a piston ring is fitted to the outer circumferential surface of the piston to ensure airtightness with the cylinder.
Shaped with a plurality of divided pieces corresponding to the external shape of the piston,
The divided pieces are arranged in an annular manner on the outer circumferential surface of the piston, and each piece is pressed against the inner circumferential wall of the cylinder using a leaf spring or the like.

However, if such a structure is adopted, it is unavoidable that a gap will be formed between each piston ring segment and the end of the other segment adjacent to this segment, and the number of such gaps will increase. can be made in the same number as the number of piston ring segments,
The total area of the gaps increases.

For example, in an internal combustion engine, if this gap exists in the piston ring, the air-fuel mixture compressed during the compression process will leak through the gap, causing a decrease in the output of the internal combustion engine.

The present invention has been developed in view of the above-mentioned problems in the prior art in order to effectively solve them.

The object of the present invention is to provide an apparatus in which a piston is reciprocally fitted into a cylinder having an irregular cross-sectional shape such as a substantially ellipse, and a piston ring fitted on the outer peripheral surface of the piston is formed of a plurality of divided pieces. A sealing member is positioned at the end matching portion of each piston ring segment, and is slidably assembled into the piston, and an elastic force such as a spring is applied to the sealing member to press it against the inner circumferential wall of the cylinder, thereby sealing the space between the segmented segments. To provide a non-ringing device for a piston for an irregularly shaped cylinder, which secures airtightness between the cylinder and the piston by press-fitting a sealing member to the cylinder even if there is a gap between them, and improves sealing performance.

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a longitudinal sectional view of an internal combustion engine to which the present invention is applied,
The internal combustion engine is formed by an assembly of an upper cylinder head 1 and a lower cylinder block 2.

A cylinder 3 is formed on the lower surface of the cylinder head 1 and inside the cylinder block 2, and a piston 4 is fitted into the cylinder 3 so as to be able to reciprocate up and down.

The crankshaft 5 is located in the crank chamber at the bottom of the cylinder 3.
is rotatably installed, and the piston 4 and crankshaft 5 are connected by a double connecting rod 6.

The cylinder head 1 is provided with four inlet valves 7 facing the combustion chamber in the upper part of the cylinder 3.
As shown in the figure, four exhaust valves 8 are also provided.

9 is a spark plug.

As is clear from FIG. 2, the cylinder 3 does not have a circular cross section, but has an oval shape due to the combination of a rectangular portion 3a in the center and semicircular portions 3b and 3C on the left and right sides of the central rectangular portion 3a, and is approximately oval in shape. There is.

Further, the cross-sectional shape of the piston 4 that fits into the cylinder 3 is also oval and approximately oval so as to fit the cylinder 3.

By making the cylinder 3 irregular in shape in this way, it is possible to improve the filling efficiency of the air-fuel mixture with respect to the effective cross-sectional area of the cylinder.

There are two piston rings 10.1 on the outer peripheral surface of the piston 4.
0 are fitted in parallel, and these piston rings 10, 10 are fitted into a ring groove 11 which is annularly shaped and has a constant depth in the piston 4, as shown in FIG.

Each piston ring 10.10 consists of two linear divided pieces 10a, 10b in the center and two semicircular divided pieces 10C, 10d curved in opposite directions on both left and right sides, and has a cross section. The divided pieces 10a to 10 are annularly formed to follow the outer peripheral shape of the piston 4, which has an oval, substantially oval shape.
By arranging d, the piston ring 10 is shaped.

A spring 12 made of a wave-shaped leaf spring is accommodated at the bottom of the ring groove 11, and this spring 12 also has the same number of individual springs 1 as the piston ring segments 10a to 10d.
By applying the elastic force of each unit 12a to 12d to the back surface of the divided pieces 108 to 10d, the piston ring 10 is pressed against the inner circumferential wall of the cylinder 3, and the cylinder 3 and the piston Keep the space between 4 and 4 airtight.

Sealing member accommodation holes 14 are located at the end matching portions 13 of each of the piston ring segment pieces 10a to 10d.
. is provided in the piston 4, and this hole 14 is shaped like a bow, drilled to an appropriate depth from the piston's outer circumferential surface, and opens at the piston's outer circumferential surface.

Further, this hole 14 is shaped so as to span two piston rings 10, 10 which are parallel to each other as shown in FIG.

A cylindrical seal member 15 shown in FIG. 4 is slidably incorporated into each hole 14.

The outer surface of the sealing member 15 is formed with two grooves 16 that are approximately the same thickness as the piston ring 10 or deeper than the piston ring 10, passing through the grooves 16 in the left-right direction. Fit piston ring 10.10 into 16.

The outer surface 15a of the sealing member 15 is shaped into a curved surface to match the curved shape of the piston 4 and cylinder 3.

A spring 17 made of a spiral leaf spring is housed at the bottom of the hole 14 in which the seal member 15 is installed, and the elastic force of the spring 17 is applied to the back surface of the seal member 15, so that the seal member 15 is inserted into the cylinder 3. Pressure is applied to the inner peripheral wall side.

The ends of the piston ring segment pieces 10a to 10d fitted in the groove 16 of the seal member 15 face each other with a small gap S in the center of the groove 16, and the edges of the segment pieces 10a to 10d, which are fitted into the groove 16 of the seal member 15, face each other with a small gap S between them. The mating portions 13 are connected by a sealing member 15.

The outer surface 15a of the sealing member 15 to which elastic force is applied by the spring 17 is pressed against the inner peripheral wall of the cylinder 3, and this outer surface 15a has a curved shape that matches the cylinder 3 whose cross-sectional shape is an irregular shape such as an ellipse. Because of its shape, it comes into close pressure contact with the inner circumferential wall of the cylinder, and when the piston 4 reciprocates within the cylinder 3, even if there is a gap S in the end fitting portion 13 of the divided pieces 10a to 10d of the piston ring 10. By pressing the sealing member 15 against the cylinder 3, leakage of the air-fuel mixture from this gap S can be effectively prevented.
The joint portions 13 of 0 1 to 10d are sealed to prevent the mixture from leaking even at the top dead center of the piston 4 where the mixture is in the maximum compression state.

In this case, even if the finish accuracy of the outer surface 15a of the seal member 15 is not maintained at a very high level, the surface area of the outer surface 15a relative to the cylinder 3 is small, so that an airtight state between the cylinder 3 and the piston 4 can be ensured.

Although the above embodiments were applied to internal combustion engines, the present invention can also be applied to cylinder pistons of compressors and the like.

Further, the number of grooves 16 formed in the seal member 15 is determined by the number of piston rings 10 fitted to the piston 4, and may be, for example, l, and is not limited to two as in the embodiment. Moreover, the number of piston ring division pieces is also arbitrary.

Further, in the above embodiment, the cross-sectional shape of the irregularly shaped cylinder 3 is oval and approximately oval, but the present invention can be applied to any irregularly shaped cylinder.

As is clear from the above description, according to the present invention, when a piston ring is formed of a plurality of divided pieces, a sealing member is assembled into the piston by positioning the seal member at the joint of the ends of the divided pieces, and the end of the divided pieces is fitted into the groove of this seal member to press the outer surface of the seal member against the inner circumferential wall of the cylinder, so even if there is a gap between the mating parts of the piston ring segments, gas such as air-fuel mixture or fluid will not leak through this gap. It prevents leakage, ensures airtightness between the irregularly shaped cylinder and piston, and improves sealing performance.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a sectional view of an internal combustion engine, FIG. 2 is a sectional view taken along line 2-2 in FIG. 1, and FIG.
The figure is a sectional view taken along the line 3-3 in FIG. 1, and FIG. 4 is a perspective view showing the shape of the sealing member. In the drawings, 3 is a cylinder, 4 is a piston, 10 is a piston ring, 10 1 to 10 b are divided pieces, 13 is a mating portion of the divided pieces, 15 is a sealing member, 16 is a groove, and 17 is a spring.

Claims (1)

[Scope of utility model registration request] In a device in which a piston is reciprocally fitted into a cylinder having an irregular cross-sectional shape such as a substantially oval shape, and a piston ring fitted on the outer peripheral surface of the piston is formed of a plurality of divided pieces, each piston ring divided piece A sealing member is slidably assembled into the piston by being positioned at the end mating part of the piston, and a groove is provided in the sealing member to fit the split end, and the sealing member is pressed by an elastic means such as a spring and is inserted into the cylinder. A ring device for a piston for an irregularly shaped cylinder, characterized in that the mating portion of the piston ring segment is sealed by pressing against the peripheral wall.