Toyota Jidosha Kabushiki Kaisha

Toru Sakuma

Toshiyuki Yano

Atsuhisa Tamano

Yuta Nishimura

Yu Yokoyama

Yuu Yokoyama

A variable valve mechanism includes a first cam unit including cams configured to drive an intake valve on a first side in a first cylinder; a first sliding mechanism configured to slide the first cam unit such that the first cam unit is switched between two positions to select any one of the cams; a second cam unit including cams configured to drive an intake valve on a second side in the first cylinder, cams configured to drive an intake valve on the first side in a second cylinder, and cams configured to drive an intake valve on the second side in the second cylinder; and a second sliding mechanism configured to slide the second cam unit such that the second cam unit is switched among three positions to select any one of the cams for each of the intake valves.

Variable valve mechanism

A first swing arm of each cylinder is swung by a fixed cam of an intake camshaft, so as to operate a first intake valve according to a profile thereof. A second swing arm is swung by a second cam and its swing range is changed by a variable mechanism. Hereby, a lift amount of a second intake valve changes continuously. The second cam is selected from a plurality of cams on a cam piece provided around the intake camshaft.

Valve device for internal combustion engine

A variable valve mechanism includes a cam shaft, a cam unit, a guide portion and a shift pin. The guide portion includes a guide plate provided on an outer periphery of a cam unit, a first stopper and a second stopper. The guide plate is pivotally supported at a first part such that a second part of the guide plate is inclined toward a first side or a second side. The first and second stoppers abut with the second part from the first side and the second side, respectively, so as to hold the second part at a first position and a second position, respectively. The first part includes two arms projecting toward the first side and the second side. The two arms are configured to swing the guide plate.

In a variable valve mechanism, a guide groove includes guide portions provided on respective side surfaces of the guide groove in a width direction, the guide portions projecting so as to face each other; a cam unit is slid toward a first side by relatively moving a shift pin toward a second side with use of the guide portion on the first side, and the cam unit is slid toward the second side by relatively moving the shift pin toward the first side with use of the guide portion on the second side; the guide portion on the first side is provided in an immovable piece, and the guide portion on the second side is provided in a movable piece; the movable piece is displaceable between a first position and a second position: and a first urging member configured to urge the movable piece toward the first position is provided.

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Nisshin, Japan

Toru Sakuma