Toyota Jidosha Kabushiki Kaisha

Yuichi Sakaguchi

Hiromasa Suzuki

Hiroyuki Kawase

Koichi Shimizu

Yuuji Yoshihara

Yuji Yoshihara

Kouichi Shimizu

A valve performance control apparatus has a low speed cam, a high speed cam, and an intermediate speed cam. A rocker arm is arranged between the cams and a valve. The rocker arm contacts the low speed cam. A pair of cam followers are reciprocally supported in the rocker arm to contact the high speed and intermediate speed cams. Lock members are slidably received in bores (or grooves) of the rocker arm. The lock members, when positioned in an unlocked position, permit the free reciprocation of the associated cam followers with respect to the rocker arm, which causes the valve to be driven by the low speed cam. When locked, the lock members abut against the associated cam followers and lock the cam followers to the rocker arm, which causes the valve to be driven by the cam with the largest profile. The lock member has an abutment surface, which contacts and is pressed by the cam follower. The bore has a supporting wall for supporting the lock member opposite to the abutment surface when the abutment surface of the lock member is positioned in the lock position and is pressed by the cam follower. The lock member is not subjected to bending or shear, which improves the reliability of the apparatus.

Valve performance control apparatus for internal combustion engines

An engine has a crankshaft, a combustion chamber and a valve that selectively opens and closes the combustion chamber. The valve has a timing relationship to the crankshaft and lift characteristic. A control device hydraulically alters at least one of the timing relationship and the lift characteristic. A lubricant passage is connected with the control device to supply oil to a mechanism that is formed by engine parts slidably contacting one another within the engine. An auxiliary passage is provided for supplying the oil to the mechanism. Oil supplied from an oil pump to said auxiliary passage is restricted by an electromagnetic valve that is actuated based on the instruction from an electric controller when engine speed is lower than a predetermined value.

Apparatus for supplying oil in engine

An engine has a crankshaft, a combustion chamber and a valve. The valve opens and closes the combustion chamber. The valve has a lift characteristic that is altered by a control device according to a change of hydraulic pressure therein. The engine has a lubricant passage that is connected with an oil pump and supplies oil to a mechanism formed by parts slidably connecting one another within the engine. A hydraulic pressure passage extends into an interior of the control device to exchange the hydraulic pressure with the control device, thereby the control device is actuated to alter the lift characteristic. The oil pump supplies the oil to the pressure passage when connected with the pressure passage. The oil pan supplies the oil to the pressure passage when connected with the pressure passage. A switching valve selects one of the oil pump and the oil pan to connect the selected one with the control device based on the engine speed.

There is disclosed a valve performance controller for an internal combustion engine. A camshaft is provided with a plurality of cams having different cam profiles. Changeover of the cams is performed through operation of a valve lift control mechanism. Also, a valve timing control mechanism is provided on the camshaft. The valve timing mechanism has a pulley, which is connected to a crankshaft of the engine via a timing belt. The pulley is connected to the camshaft via a ring gear. Through movement of the ring gear along the axis of the camshaft, the relative rotational phase between the pulley and the camshaft is changed. At least during cam changeover operation, oil is charged and retained within the hydraulic chamber located on both sides of the ring gear in the moving direction thereof. This structure reduces an impact which acts on the timing belt upon changeover of the cams.

Growing community of inventors

Nagoya, Japan

Yuichi Sakaguchi