Patent ID: 8495977

Claim:
An intake and exhaust device of a 4-stroke internal combustion engine, comprising: a cylinder block for generating a rotational driving force in cooperation with the rotation of a crank shaft as an up and down reciprocating movement of a piston is transferred thereto with the aid of a connecting rod; a cylinder head which is engaged to an upper side of the cylinder block, with a first intake manifold opened and closed by means of a first intake and exhaust valve being connected to one side of the cylinder head, with a second intake and exhaust manifold opened and closed by means of a second intake and exhaust valve being connected to the other side of the cylinder head; a first cam shaft which is installed at an upper side of the cylinder head and rotates in cooperation with the rotation of the crank shaft with a first intake and exhaust cam, which drives the first intake and exhaust valve, being engaged to the first cam shaft; a second camp shaft which is installed at an upper side of the cylinder and rotates in cooperation with the rotation of the crank shaft with a second intake and exhaust cam, which drives a second intake and exhaust valve, being engaged to the second cam shaft; a third cam shaft which is installed at an upper side of the cylinder head and rotates in cooperation with the rotation of the second cam shaft; a first intake and exhaust adjusting means which is installed at the first intake and exhaust manifold for thereby selectively adjusting either an intake of a mixed fuel or air or an exhaust of combustion gas; a second intake and exhaust adjusting means which is installed at the second intake and exhaust manifold for thereby selectively adjusting either an intake of a mixed fuel or air or an exhaust of a combustion gas; and an exhaust connection pipe which communicates with the first intake and exhaust manifold and the second intake and exhaust manifold, respectively, and forms an exhaust passage of a combustion gas.