Abstract: A cylinder structure of a diesel engine in which diesel fuel is ignited by a self-ignition manner includes a cylinder including a cylinder body in which a combustion chamber is formed and a cylinder head covering an upper portion of the cylinder body, at least one intake valve included in an intake port formed in the cylinder head, at least one exhaust valve included in an exhaust port formed in the cylinder head, and a diesel injector mounted at the center of the cylinder head and injecting diesel fuel. A lower surface of the cylinder head may be formed in a pent roof shape.

Abstract: A variable compression ratio apparatus for a vehicle engine that is mounted at the engine receiving combustion force of an air-fuel mixture from a piston and rotating a crankshaft mounted between upper and lower cylinder blocks, and that changes compression ratio of the air-fuel mixture by changing a mounting height of the crankshaft according to a driving condition of the engine, may include a bearing having a hollow space eccentric to a center thereof and rotatably mounted between the upper and lower cylinder blocks, the crankshaft being rotatably inserted in the hollow space; and an operating unit provided at the lower cylinder block and controlling a rotational displacement of the bearing.

Abstract: A variable compression ratio apparatus, and an engine using the same, is configured to change the compression ratio of an air-fuel mixture in a combustion chamber according to a driving condition of an engine. The variable compression ratio apparatus may be mounted at an engine receiving a combustion force of an air-fuel mixture from a piston so as to rotate a crankshaft disposed between cylinder blocks, wherein the variable compression ratio apparatus changes the compression ratio of the air-fuel mixture by changing the mounting height of the crankshaft according to a driving condition of the engine.

Abstract: A variable compression ratio apparatus for a vehicle engine that is mounted at the engine receiving combustion force of an air-fuel mixture from a piston and rotating a crankshaft mounted between upper and lower cylinder blocks, and that changes compression ratio of the air-fuel mixture by changing a mounting height of the crankshaft according to a driving condition of the engine, may include a bearing having a hollow space eccentric to a center thereof and rotatably mounted between the upper and lower cylinder blocks, the crankshaft being rotatably inserted in the hollow space; and an operating unit provided at the lower cylinder block and controlling a rotational displacement of the bearing.

Abstract: A variable compression ratio apparatus for a vehicle engine that is mounted at the engine and rotating a crankshaft mounted between upper and lower cylinder blocks, and that changes compression ratio of the air-fuel mixture by changing a mounting height of the crankshaft according to a driving condition of the engine, may include a supporter having a lower surface formed of a slanted surface and mounted between the upper and lower cylinder blocks, the crankshaft being rotatably inserted in the supporter through a bearing, an elastic member mounted at an upper portion of the supporter, a slider slidingly contacted to the slanted surface of the supporter and supported by the lower cylinder block, an operation unit applying operating force to the slider, and a power delivery unit connecting the slider with the operation unit and transmitting the operating force of the operation unit to the slider.

Abstract: A variable compression ratio apparatus, and an engine using the same, is configured to change the compression ratio of an air-fuel mixture in a combustion chamber according to a driving condition of an engine. The variable compression ratio apparatus may be mounted at an engine receiving a combustion force of an air-fuel mixture from a piston so as to rotate a crankshaft disposed between cylinder blocks, wherein the variable compression ratio apparatus changes the compression ratio of the air-fuel mixture by changing the mounting height of the crankshaft according to a driving condition of the engine.