Valve operation stopping means for multi-cylinder engine

Claim 2

In a valve operating mechanism for multi-cylinder internal combustion engine including a cam shaft with a plurality of cams formed integrally with said cam shaft at positions corresponding to suction valves and exhaust valves for each cylinder, a valve operation stopping device comprising a drive rocker arm engaging one of said cams, a driven rocker arm engaging one of either the suction valves or the exhaust valves, said drive rocker arm and said driven rocker arm being pivotably supported on the same axis to permit relative angular displacement, a synchro pin slidably mounted in said driven rocker arm to engage with said drive rocker arm to prevent said relative axial displacement, means biasing said synchro pin toward engagement with said drive rocker arm, and a timing piston provided in said drive rocker arm at a position corresponding to said synchro pin and acting to urge said synchro pin toward said driven rocker arm by hydraulic pressure to release connection between said drive rocker arm and said driven rocker arm.

Claim 3

The valve operation stopping device for the multi-cylinder internal combustion engine as defined in claim 1, wherein said drive rocker arm is provided with a trigger plate for restricting movement of said timing piston according to an angular position of said drive rocker arm.

Claim 4

The valve operation stopping device for the multi-cylinder internal combustion engine as defined in claim 1, wherein the diameters of said timing piston and said synchro pin are such as to retain abutment engagement of said timing piston and said synchro pin irrespective of said relative angular displacement of said drive rocker arm and said driven rocker arm.

Claim 5

The valve operation stopping device of claim 1 wherein another rocker arm is pivotally supported on the same axis as the drive and driven rocker arms and engages another of said cams, means adjustably connecting said another rocker arm and said drive rocker arm to pivot together with one cam and arm causing valve opening and the other cam and arm causing valve closing.

Claim 6

The valve operation stopping device of claim 1 wherein said synchro pin is mounted to slide on an axis parallel with and spaced from the pivotal axis of said rocker arms.

Claim 7

The valve operation stopping device of claim 5 wherein said timing piston is mounted to slide on the same axis as said synchro pin when said rocker arms are angularly positioned for interengagement by said synchro pin.

Claim 8

The valve operation stopping device of claim 1 wherein said timing piston is comprised of two axially slidable members, a spring means biasing said two members apart and said hydraulic pressure acting only on one said member with the other said member comprising the portion of said timing piston that engages said synchro pin.

Claim 9

The valve operation stoppping device of claim 7 wherein said two members form a groove between portions thereof in their axially extended relationship which groove is closed in their axially collapsed relationship, and a trigger plate mounted on said drive rocker arm and movable to a position to engage said groove between said two members to prevent the said release between said arms.

Claim 10

The valve operation stopping device of claim 8 wherein means are provided for engaging said trigger plate during pivoting of said drive rocker arm for moving said trigger plate out of engagement with said groove.

Claim 11

The valve operation stopping device of claim 7 wherein said one member is provided with circumferential groove means, and a trigger plate is movably mounted on said drive rocker arm for engaging said circumferential groove means for selectively preventing movement of said timing piston one member.

Claim 12

The valve operating mechanism of claim 1 wherein first and second valve operation stopping device are provided for separately operating the suction and exhaust valves, respectively, of selected cylinder, and means are provided for controlling the order of supply and release of hydraulic pressure to the timing pistons of said respective devices for always causing valve operations stopping of the suction valve before the exhaust valve.

Claim 13

The valve operating mechanism of claim 11 wherein said controlling means includes means for causing valve operation restarting of said exhaust and suction valves to occur substantially simultaneously.

Claim 14

The valve operating mechanism of claim 11 wherein passages connect the said timing pistons of said first and second valve operation stopping devices, check valves provided in said passages, and said passages arrange to allow pressurized hydraulic fluid to flow to said second timing piston only after full movement of said first timing piston to the suction valve operation stopping position.

Claim 15

The valve operation stopping device for the multi-cylinder internal combustion engine as defined in claim 1, wherein said drive rocker arm is provided with a trigger plate for restricting movement of said timing piston according to an angular position of said drive rocker arm.

Claim 16

The valve operation stopping device for the multi-cylinder internal combustion engine as defined in claim 1, wherein the diameters of said timing piston and said synchro pin are related in such a manner as to retain abutment of said timing piston and said synchro pin irrespective of relative angular displacement of said drive rocker arm and said driven rocker arm.

Claim 17

In a multi-cylinder internal combustion engine including a cam shaft adapted to be rotated synchronously with rotation of the engine crankshaft, a plurality of cams formed integrally with said cam shaft at positions corresponding to suction valves and exhaust valves for each cylinder, a rocker shaft arranged in parallel relation with said cam shaft, and a plurality of rocker arms pivotably supported to said rocker shaft and adapted to be rocked in contact with said cams for each cylinder and operate said suction and exhaust valves, a valve operation stopping device comprising a separate drive rocker arm engaging the suction and exhaust cams associated with a specific cylinder, a separate driven rocker arm engaging said suction valve and said exhaust valve of that cylinder, each said drive rocker arm and said driven rocker arm being pivotably supported on said rocker shaft to allow relative angular displacement, a synchro pin provided in each said driven rocker arm to slidably engage with the associated said driven rocker arm, each said synchro pin being axially slidable and biased by a spring in a direction to engage said drive rocker arm, and a timing piston provided in said drive rocker arm at a position corresponding to said synchro pin and acting to urge said synchro pin toward said driven rocker arm by hydraulic pressure to release connection between said drive rocker arm and said driven rocker arm.

Claim 18

In a multi-cylinder internal combustion engine including a cam shaft adapted to be rotated synchronously with rotation of the engine crankshaft, a plurality of cams formed integrally with said cam shaft at positions corresponding to suction valves and exhaust valves for each cylinder, a rocker shaft arranged in parallel relation with said cam shaft, and a plurality of rocker arms pivotably supported to said rocker shaft and adapted to be rocked in contact with said cams for each cylinder and operate said suction and exhaust valves, a valve operation stopping device comprising a separate drive rocker arm engaging the suction and exhaust cams associated with a specific cylinder, a separate driven rocker arm engaging said suction valve and said exhaust valve of that cylinder, each said drive rocker arm and said driven rocker arm being pivotably supported on said rocker shaft to allow relative angular displacement, a synchro pin provided in each said driven rocker arm to slidably engage with the associated said driven rocker arm, each said synchro pin being axially slidable and biased by a spring in a direction to engage said drive rocker arm, and a timing piston provided in said drive rocker arm at a position corresponding to said synchro pin and acting to urge said synchro pin toward said driven rocker arm by hydraulic pressure to release connection between said drive rocker arm and said driven rocker arm.

Claim 19

In a valve operating mechanism for a multi-cylinder internal combustion engine having a cam shaft with cams for actuating each of the exhaust and suction valves, at least one cylinder having exhaust and suction valve operation stopping devices, comprising for each valve, a drive rocker arm and a driven rocker arm mounted for pivotal rocking on the same axis together for valve operation and separately for valve operation stopping, said drive rocker arm engaging a said cam and said driven rocker arm engaging a said valve, and means for selective connecting and disconnecting said drive rocker arm and driven rocker arm including a timing piston slidably mounted on one rocker arm and a synchro pin slidably mounted on the other rocker arm in juxtaposed positions for interengagement and sliding on an axis parallel to said axis of pivotal rocking of said rocker arms, said synchro pin selectively engageable with both arms for causing simultaneous pivoting of said arms, and means for selectively causing sliding movement of said timing piston relation to the angular positions of said rocker arms for inturn causing engagement and disengagement of said synchro pin between the two rocker arms.

Claim 20

In a valve operating mechanism for a multi-cylinder internal combustion engine having a cam shaft with cams for actuating each of the exhaust and suction valves, at least one cylinder having exhaust and suction valve operation stopping devices, comprising for each valve, a drive rocker arm and a driven rocker arm mounted for pivotal rocking on the same axis together for valve operation and separately for valve operation stopping, said drive rocker arm engaging a said cam and said driven rocker arm engaging a said valve, and means for selective connecting and disconnecting said drive rocker arm and driven rocker arm including a timing piston slidably mounted on one rocker arm and a synchro pin slidably mounted on the other rocker arm in juxtaposed positions for interengagement and sliding on an axis parallel to said axis of pivotal rocking of said rocker arms, said synchro pin selectively engageable with both arms for causing simultaneous pivoting of said arms, and means for selectively causing sliding movement of said timing piston relation to the angular positions of said rocker arms for inturn causing engagement and disengagement of said synchro pin between the two rocker arms.

Claim 21

The valve operating mechanism of claim 17 wherein said means for causing timing piston movement includes a hydraulic fluid supply means operable in response to engine load conditions.

Claim 22

The valve operation mechanism of claim 17 wherein said means for selectively causing movement of said timing piston includes trigger plate means for mechanically restraining said timing piston in selected positions during non-movement of said drive rocker arm corresponding to the closed position of the valve.