JP2011157885A - Reciprocating engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating engine in which adherence and deposition of carbon are not produced in a gas chamber, even when the engine is operated for a long period, and introduction, holding, and discharge of high-pressure combustion gas to the gas chamber are repeated. <P>SOLUTION: The reciprocating engine 1 has a gas chamber 4 formed, surrounded by a top ring 5, second ring 6, and second land 7 of a piston 2, and an inner surface 8 of a cylinder. At the beginning of an expansion stroke, a high-pressure combustion gas 12 from above the piston 2 is introduced into the gas chamber from a gas passage hole 23 provided at the top 22 of a thrust side 10 of the inner surface 8 of the cylinder. The piston 2 is supported from the thrust side 10 by this introduced high-pressure combustion gas 12. A half-ring 13 is inserted into the gas chamber 4 so as to cover the second land 7 from the thrust side 10 and so as to move vertically with a gap 20 in a vertical direction, and vertically moves by the gap distance 20 with reciprocation of the piston 2, so that the inside of the gas chamber 4 is continually cleaned. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an improvement in a reciprocating engine in which the piston is supported by high-pressure combustion gas (gas pressure float) against the side pressure acting on the piston in an explosion / expansion stroke, and the frictional resistance between the piston and the cylinder is reduced. .

  In the techniques described in these (Patent Documents 1 to 4), a gas chamber is formed in the second land portion of the piston, and at the initial stage of the explosion / expansion stroke, a gas passage hole provided in the cylinder inner surface is provided in the gas chamber to This technique introduces and holds high-pressure combustion gas, supports the piston from the thrust side by the high-pressure combustion gas introduced and held, and reduces the frictional resistance between the piston and the inner surface of the cylinder.

International Publication No. 92/02722 International Publication No. 2004/079177 European Patent Application Publication No. 1878901 International Publication No. 2008/047453

  However, during operation of the engine, introduction, retention, and discharge of high-pressure combustion gas above the piston are repeated in the gas chamber. Then, carbon deposits gradually accumulate on the surface of the gas chamber.

  Therefore, the present invention provides a reciprocating engine in which carbon adhesion and accumulation do not occur in the gas chamber even when the operation of the engine is performed for a long period of time and the introduction, maintenance, and discharge of the high-pressure combustion gas are repeated in the gas chamber. Is.

  High pressure above the piston from the gas passage hole provided in the upper part on the thrust side of the cylinder inner surface in the gas chamber formed by the piston top ring, the second ring, the second land, and the cylinder inner surface. In the reciprocating engine in which the combustion gas is introduced and the piston is supported from the thrust side by the introduced high-pressure combustion gas, the half ring is placed on the second land from the thrust side in the gas chamber, and the vertical direction Is a reciprocating engine that is inserted in a vertically movable manner with a gap, and is moved up and down by the gap by the reciprocating motion of a piston so that the gas chamber is always cleaned.

  In the reciprocating engine of the present invention, the “up and down direction” and the “up and down movement” are directions along the reciprocating direction of the piston and are movements.

  Even if the gas chamber is exposed to repeated introduction, maintenance, and discharge of high-pressure combustion gas, the halved ring continues to move up and down constantly in the gas chamber, and cleaning is performed. No accumulation occurs.

FIG. 1 is a longitudinal sectional view of a reciprocating engine according to an embodiment of the present invention. FIG. 2 is an explanatory view of the same longitudinal cross section showing the half ring in FIG. 1 in cross section. FIG. 3 is a perspective view of the half ring shown in FIGS.

  Embodiments of the present invention will be described below based on examples shown in the drawings.

  1 and 2 show an initial state of the lowering process of the piston 2 in the explosion / expansion stroke.

  1 and 2 show the reciprocating engine 1 of the present embodiment in the early stage of the explosion / expansion stroke.

  2 is a piston, 3 is a cylinder. Reference numeral 4 denotes a gas chamber.

  The gas chamber 4 is formed by being surrounded by a top ring 5, a second ring 6, a second land 7, and a cylinder inner surface 8 of the piston 2. The gas chamber 4 has a vertical width 9 wide on the thrust side 10 and narrow on the anti-thrust side 11.

  This is because the piston 2 is supported from the thrust side 10 by the high-pressure combustion gas 12 introduced and held (in opposition to the piston side pressure) by increasing the area receiving the gas pressure on the thrust side 10 and reducing it on the anti-thrust side 11. This is to reduce the pushing back from the anti-thrust side 11.

  An arc-shaped half ring 13 is inserted into the gas chamber 4 from the thrust side 10 so as to cover the second land 7.

  The half ring 13 is inserted in the gas chamber 4 so as to be movable up and down with a gap 17 in the vertical direction (reciprocating direction of the piston 2).

  Hereinafter, as shown in FIG. 3, the half ring 13 is formed in an arc shape matching the circumferential surface of the second land 7.

  The half ring 13 has a front surface and a side surface that match the shape of the gas chamber 4, and the vertical width 14 is wide at the front central portion 15 and narrow at both side ends 16 and 16.

  Further, the half ring 13 has the vertical width 14 shorter than the vertical width 9 of the gas chamber 4 as a whole. This is because the gap 17 is formed in the vertical direction in a state where the half ring 13 is inserted into the gas chamber 4. The half ring 13 moves up and down in the gas chamber 4 by the distance of the gap 17.

  As shown in FIGS. 1 and 2, the half ring 13 is inserted into the gas chamber 4 with the front center portion 15 aligned with the thrust side 10.

  In particular, the half ring 13 moves up and down to sweep up and down the surface of the second land 7 forming the gas chamber 4 by reciprocating movement of the piston 2 during engine operation.

  Of course, the thickness t of the half ring 13 can freely move up and down (along the reciprocating direction of the piston 2) during engine operation within the gap 20 between the cylinder inner surface 8 and the surface 19 of the second land 7. Is the thickness.

  The half ring 13 is formed of a heat-resistant metal plate such as stainless steel or spring steel.

  In addition, with respect to the piston 2 of the reciprocating engine 1 of the present embodiment, the top ring 5 that forms the gas chamber 4 is provided in parallel with the piston top surface 18, while the second ring 6 is directed toward the thrust side 10. It is provided with a downward slope. That is, the second ring 6 is provided farther away from the top ring 5 on the thrust side 10 and closer to the anti-thrust side.

  Therefore, the distance (distance) between the top ring 5 and the second ring 6, that is, the vertical width 9 of the gas chamber 4 is wide on the thrust side 10 and gradually becomes narrower as it approaches the anti-thrust side 11.

  A plurality of gas passage holes 23 are provided in the upper portion 22 of the thrust side 10 of the cylinder inner surface 8. In the downward stroke of the piston 2, when the top ring 5 of the piston 2 passes over the gas passage hole 23, the combustion chamber 25 above the piston 2 and the gas in the piston 2 pass through the recess 24 of the gas passage hole 23. The high-pressure combustion gas 12 in the combustion chamber 25 is introduced into the gas chamber 4 and held therein.

  That is, at the initial stage of the explosion / expansion stroke, when the top ring 5 of the piston 2 passes through the gas passage hole 23 in the upper part of the cylinder inner surface 8, the combustion chamber 25 above the piston 2 and the gas chamber 4 of the piston 2 communicate with each other. The high-pressure combustion gas 12 is introduced and held in the gas chamber 4.

  At this time, the piston 2 tends to be pressed against the cylinder inner surface 8 against the thrust side 10 under the action of side pressure, but is supported from the thrust side 10 by the high-pressure combustion gas 12 introduced and held in the gas chamber 4 (piston 2 The descent process is lowered in a state of being opposed to the side pressure acting on the air.

  According to the reciprocating engine 1 of the present embodiment as described above, the combustion gas 12 is introduced (inflowed), held, and discharged into the gas chamber 4 of the piston 2 while the engine is operating, that is, while the piston 2 is reciprocating. While being repeatedly performed, the half ring 13 continues to move up and down in the gas chamber 4 and always cleans the gas chamber 4. For this reason, the gas chamber 4 repeatedly receives and holds the high-pressure combustion gas 12, but due to the cleaning action of the half ring 13, carbon adheres to the inside of the gas chamber 4, particularly the surface 19 of the second land 7, etc. Occurrence of deposition is prevented.

DESCRIPTION OF SYMBOLS 1 Reciprocating engine 2 Piston 3 Cylinder 4 Gas chamber 5 Top ring 6 Second ring 7 Second land 8 Cylinder inner surface 9 Gas chamber vertical width 10 Thrust side 11 Anti-thrust side 12 High pressure combustion gas 13 Half ring 14 Half ring vertical Width 15 Front center portion 16 Both side ends 17 Vertical gap 18 Piston top surface 19 Second land surface 20 Gap 22 Upper portion 23 Gas passage hole 24 Recess 25 Combustion chamber

Claims (1)

  In the gas chamber formed by the piston's top ring, second ring, second land, and cylinder inner surface, in the initial stage of the expansion stroke, the gas passage hole provided in the upper part on the thrust side of the cylinder inner surface is located above the piston. In a reciprocating engine in which high-pressure combustion gas is introduced and the piston is supported from the thrust side by the introduced high-pressure combustion gas, the half ring is placed on the second land from the thrust side in the gas chamber and A reciprocating engine that is inserted so as to freely move up and down with a gap in the direction, and moves up and down by the gap by the reciprocating movement of the piston so that the gas chamber is always cleaned.

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