Yamaha Hatsudoki Kabushiki Kaisha

Tomoegawa Paper Co., Inc.

Yamaha Motor Company Ltd

Yamaha Hatsudoki Kaisha

Hatamura, Koichi

Hideo Fujita

Koichi Hatamura

Hidetoshi Ishigami

Nobuyuki Aoki

Atsushi Suzuki

Shigenobu Uchiyama

Kenji Komatsu

Hidetoshi Kageyama

Noboru Nowatari

Jiro Aoshima

A valve gear for an engine includes cam shafts, first and second support walls, and rocker arms supported on the first and second support walls by supports. The supports switch among a plurality of support modes. The supports include first and second shaft holes, rocker shafts, tracks in the support walls, and return springs. The rocker shafts, move to positions where the support walls and the rocker arms are connected via the rocker shafts in a first support mode. In a second support mode, the rocker shafts move to positions where the connection between the support walls and the rocker arms is canceled. This makes it possible to provide a valve gear for an engine capable of smoothly switching a normal operation state support mode and cylinder resting state support mode, thus increasing the reliability of the operation.

Valve gear for engine

An engine can include a first catalyst disposed in a first exhaust passage, a second catalyst disposed in a second exhaust passage to be located upstream of the first catalyst, a variable valve operating mechanism configured to make lifting amounts of a first and second exhaust valves variable between approximate zero and maximum, and a lifting amount control unit for controlling the lifting amounts of the first and second exhaust valves with the variable valve operating mechanism such that an exhaust gas amount passing through the second exhaust passage is larger than that passing through the first exhaust passage.

Engine

A valve drive device for an engine include a valve for opening or closing an opening of a port to a combustion chamber, a valve drive member for opening or closing the valve and a drive shaft for driving the valve drive member. The device also includes a variable valve timing mechanism for continuously changing a working angle of the valve corresponding to an operation state of the engine by changing a state of drive force transmission from the drive shaft to the valve drive member. A variable valve clearance mechanism is configured such that a valve clearance that is defined as a gap between the valve and the valve drive member can be set at a first value during a first condition in which the working angle of the valve is large to a second different value during a second condition in which the working angle of the valve is small.

Variable valve drive system for engine

A motorcycle includes an air inlet pipe, an airflow box, an air cleaner box, and a throttle body as an air passage arranged to allow outside air to be taken into the engine. The air inlet pipe is provided in a front portion of a main frame. The air inlet pipe is provided with an airflow sensor and a throttle valve. An air cleaner element is provided between the airflow sensor and the engine.

Intake system and motorcycle including the same

A valve train device for an engine for driving a valve which opens and closes a valve opening of a combustion chamber comprises: a valve drive device comprising a drive member and driving force transmission mechanism. The drive force transmission mechanism is configured to transmit a driving force from the drive member to the valve. The drive force transmission mechanism comprises a transmission portion configured to transmit the driving force from the drive member to the valve and a variable portion configured to continuously change a state of the transmission portion to thereby continuously change an opening duration of the valve or the amount of valve lift. At least part of the variable portion is positioned within in the transmission portion.

Valve train device for engine

A multiple cylinder engine includes a plurality of cylinders. Each cylinder includes a valve configured to open and close a port associated with each of the respective cylinders. The cylinders comprises at least a first cylinder group and a second cylinder group. A drive shaft is configured to rotate about an axis. A plurality of valve actuators are configured to transmit rotational movement of the drive shaft to the valve. A change mechanism comprises a control member that is configured to change a transmission state of the rotational movement transmitted from the drive shaft to the valve actuators. The change mechanism is configured to sequentially change an open period and a lift amount of each valve by changing a control amount of the control member. The control member is common to the first and second cylinder groups and the transmission states for the first cylinder group differs from the transmission states of the second cylinder group in accordance with the control amount of the control member. The valve open period and the lift amount of the valves in the first cylinder group is capable of being set to zero in a predetermined operational range to suspend operation of the first cylinder group.

Multiple cylinder engine

A valve drive mechanism for an engine can include a drive shaft that is configured for rotation about an axis. A valve member is configured to be driven by the rotation of the drive shaft to open and close a valve. A variable valve timing mechanism is positioned at least partially between the valve member and the drive shaft. The variable valve timing mechanism is configured to vary a valve open period of the valve. The valve drive mechanism is configured such that, during a specific operation range, the valve open period includes a main valve open period during which the valve is open in a suction or exhaust stroke, and a sub valve open period during which the valve is open in an expansion or compression stroke.

Valve drive mechanism for engine

A rotational cam can be disposed on a camshaft rotationally driven by a crankshaft of an internal combustion engine. A swing cam can be swingable through the rotational cam. The swing cam has a rotational cam abutment portion which contacts the rotational cam and transmits driving force from the rotational cam to the swing cam. An abutment portion displacing mechanism can be provided for displacing the rotational cam abutment portion to change a relative distance between the rotational cam abutment portion and a center axis of the swing shaft. Changing the relative distance allows changing a lift and the like of a valve.

Variable valve train mechanism of internal combustion engine

A valve drive mechanism is provided for opening and closing a valve of an engine. The device comprises a valve drive device and a swing member pivotally supported on a swing member support shaft. The swing member is driven to pivot about the swing member support shaft by the valve drive device. A cam surface is formed on the swing member. The cam surface is configured to transfer motion of the swing member to a second member of the valve drive device. The cam surface comprises a first portion that is configured to contact the second member while the valve is moving from a closed or substantially closed position to an open position and a second portion configured to contact the second member when the valve is closed or substantially closed. A width of the second portion of the cam surface is smaller than a width of the first portion of the cam surface.

Valve mechanism for internal combustion engine

A valve drive mechanism for actuating a valve of an internal combustion engine includes a cam member with a cam surface having a first portion and a second portion. A roller is configured to rotate and contact the first portion of the cam surface when the valve is in a closed position and the second portion of the cam surface with the valve is in an open position. The cam member and the roller are configured to reciprocally move relative to each other to open and close the valve. When the roller contacts the first portion, a gap within the valve drive mechanism exists between components of the valve drive mechanism on a downstream side of a force transmission path to the valve with respect to a contact point between the roller and the cam surface. A spring member urges the roller and the cam surface into contact with each other during motion between the cam member and the roller.

Valve mechanism for an internal combustion engine

A valve train device for an engine is configured to pivot a rocker arm supported on a rocker arm support shaft to drive a valve which opens and closes a valve opening formed in a combustion chamber. The device comprises a valve drive device and a swing member pivotally supported on a swing member support shaft and driven to pivot about the swing member support shaft by the valve drive device. A control arm is disposed between a swing cam surface formed on the swing member and a rocker-side surface formed on the rocker arm. The control arm is configured for transferring motion of the swing cam surface to the rocker-side surface. A displacement mechanism is provided for displacing a contact point between the control arm and the swing cam surface and a contact point between the control arm and the rocker-side surface. The rocker-side surface has an arcuate shape which arcs about a center of pivoting motion of the swing member and wherein the rocker-side surface or an extension of the rocker-side surface about said center of pivoting motion of the swing member passes in substantially near a center of swing of the rocker arm.

A valve train device is provided for swinging a rocker arm, which is pivotally disposed on a rocker arm support shaft. The device comprises a drive device for driving the rocker arm, an intermediate member disposed between the drive device and the rocker arm and configured to transfer movement of the drive device to the rocker arm, and a displacement device. The displacement device is configured to displace a contact point between the rocker arm and the intermediate member to continuously adjust at least one of the valve opening duration and valve lift.

Valve train device for an engine

A valve train device for an engine is adapted to pivot a rocker arm supported on a rocker arm support shaft to drive a valve which opens and closes a valve opening formed in a combustion chamber. The device comprises a valve drive device and a swing member pivotally supported on a swing member support shaft and driven to pivot about the swing member support shaft by the valve drive device. An intermediate rocker member is pivotally supported on the rocker arm support shaft. The intermediate rocker member is provided between a swing cam surface formed on the swing member and a rocker face formed on the rocker arm, for transmitting the movement of the swing cam surface generated by the valve drive device to the rocker face. An intermediate rocker moving mechanism is configured to rotate the rocker arm support shaft and thereby move a first contact point between the intermediate rocker member and the swing cam surface and a second contact point between the intermediate rocker member and the rocker face to continuously vary at least one of the valve opening duration and the amount of valve lift.

Several embodiments of anti-rotation devices for precluding rotation of the valve actuating lifters or tappet bodies caused by the action of the cam lobe on the engaged surface of the lifter. In each embodiment, the anti-rotation function is achieved without adding to the reciprocating masses of the engine.

Growing community of inventors

Shizuoka-ken, Japan

Hideo Fujita