Phase adjusting apparatus and a cam shaft phase adjusting apparatus for an internal combustion engine

A cam shaft phase adjusting apparatus for an internal combustion engine, comprising:

• phase shift device, which performs phase shift between a crankshaft and a cam shaft and includes advanced angle hydraulic chambers, which are increased in volume when a phase angle of the cam shaft relative to the crankshaft changes in a direction of advanced angle, and retarded angle hydraulic chambers, which are increased in volume when a phase angle of the cam shaft relative to the crankshaft changes in a direction of retarded angle;
• first and second oil path systems, which are independent from each other and are communicated to the advanced angle hydraulic chambers, according to change in rotating angle of the cam shaft, in respective predetermined rotating angle ranges of the cam shaft,
• third and fourth oil path systems, which are independent from each other and are communicated to the retarded angle hydraulic chambers, according to a change in rotating angle of the cam shaft, in respective predetermined rotating angle ranges of the cam shaft;
• a first switchover unit, which performs switching between communication and cut-off according to a rotating angle of the cam shaft such that one of the first and second oil path systems is cut off from the advanced angle hydraulic chambers while the other of the first and second oil path systems is communicated to the advanced angle hydraulic chambers, and
• a second switchover unit, which performs switching between communication and cut-off according to a rotating angle of the cam shaft such that one of the third and fourth oil path systems is cut off from the retarded angle hydraulic chambers while the other of the third and fourth oil path systems is communicated to the retarded angle hydraulic chambers.

A cam shaft phase adjusting apparatus for an internal combustion engine, comprising:

• phase shift device, which performs phase shift between a crankshaft and a cam shaft and includes advanced angle hydraulic chambers, which are increased in volume when a phase angle of the cam shaft relative to the crankshaft changes in a direction of advanced angle, and retarded angle hydraulic chambers, which are increased in volume when a phase angle of the cam shaft relative to the crankshaft changes in a direction of retarded angle;
• first and second oil path systems, which are communicated to the advanced angle hydraulic chambers in respective predetermined angle ranges when a phase angle of the cam shaft relative to the crankshaft changes;
• and
• third and fourth oil path systems, which are communicated to the retarded angle hydraulic chambers in respective predetermined angle ranges when a phase angle of the cam shaft relative to the crankshaft changes;
• a fifth oil path system communicated to the advanced angle hydraulic chambers at all times;
• and
• a sixth oil path system communicated to the retarded angle hydraulic chambers at all times, and
• wherein the first and second oil path systems are provided as mutually independent oil path systems and provided to have a phase angle range so that one of them is cut off from the advanced angle hydraulic chambers when the other is communicated to the advanced angle hydraulic chambers, and
• the third and fourth oil path systems are provided as mutually independent oil path systems and provided to have a phase angle range so that one of them is cut off from the retarded angle hydraulic chambers when the other is communicated to the retarded angle hydraulic chambers.

A cam shaft phase adjusting apparatus for an internal combustion engine, comprising:

• phase shift device, which performs phase shift between a crankshaft and a cam shaft and includes advanced angle hydraulic chambers, which are increased in volume when a phase angle of the cam shaft relative to the crankshaft changes in a direction of advanced angle, and retarded angle hydraulic chambers, which are increased in volume when a phase angle of the cam shaft relative to the crankshaft changes in a direction of retarded angle;
• a plurality of advanced angle chamber oil path systems which are communicated to the advanced angle hydraulic chambers according to a rotating angle of the cam shaft;
• a plurality of retarded angle chamber oil path systems which are communicated to the retarded angle hydraulic chambers according to a rotating angle of the cam shaft;
• an intermittent switchover unit for switching between communication and cut-off according to a rotating angle of the cam shaft such that one of the plurality of advanced angle chamber oil path systems is cut off from the advanced angle hydraulic chambers while the other of the plurality of advanced angle chamber oil path systems is communicated to the advanced angle hydraulic chambers, and one of the plurality of retarded angle chamber oil path systems is cut off from the retarded angle hydraulic chambers while the other of the plurality of retarded angle chamber oil path systems is communicated to the retarded angle hydraulic chambers;
• and
• a communication switchover unit, which provides communication or cut-off between the plurality of advanced angle chamber oil path systems and provides communication or cut-off between the plurality of retarded angle chamber oil path systems according to a rotating angle of the cam shaft.

A cam shaft phase adjusting apparatus for an internal combustion engine, comprising:

• phase shift device, which performs phase shift between a crankshaft and a cam shaft and includes advanced angle hydraulic chambers, which are increased in volume when a phase angle of the cam shaft relative to the crankshaft changes in a direction of advanced angle, and retarded angle hydraulic chambers, which are increased in volume when a phase angle of the cam shaft relative to the crankshaft changes in a direction of retarded angle;
• first and second oil path systems, which are independent from each other and are communicated to the advanced angle hydraulic chambers in respective predetermined rotating angle ranges according to a change in rotating angle of the cam shaft;
• third and fourth oil path systems, which are independent from each other and are communicated to the retarded angle hydraulic chambers in respective predetermined rotating angle ranges according to a change in rotating angle of the cam shaft;
• a first switchover unit, which performs switching between communication and cut-off according to a rotating angle of the cam shaft such that one of the first and second oil path systems is cut off from the advanced angle hydraulic chambers while the other of the first and second oil path systems is communicated to the advanced angle hydraulic chambers;
• a second switchover unit, which performs switching between communication and cut-off according to a rotating angle of the cam shaft such that one of the third and fourth oil path systems is cut off from the retarded angle hydraulic chambers while the other of the third and fourth oil path systems is communicated to the retarded angle hydraulic chambers;
• and
• switchover means, which performs switching among designations, to which the first, second, third and fourth oil path systems are connected, and
• wherein one of the first and second oil path systems is an inlet side oil path system and the other is an outlet side oil path system, and one of the third and fourth oil path systems is an inlet side oil path system and the other is an outlet side oil path system,
• wherein the switchover means performs switching between an advanced angle mode, in which the inlet side oil path system out of the first and second oil path systems is connected to a hydraulic power source and the outlet side oil path system out of the third and fourth oil path systems is connected to a drain, and a retarded angle mode, in which the inlet side oil path system out of the third and fourth oil path systems is connected to the outlet side oil path system out of the first and second oil path systems,
• whereby when a phase angle of the cam shaft acts in the direction of advanced angle in the advanced angle mode, phase shift of the cam shaft is performed through the advanced angle hydraulic chambers by the hydraulic power source and the drain and by the acting torque in the direction of advanced angle, and when a phase angle of the cam shaft acts in the direction of retarded angle in the retarded angle mode, phase shift of the cam shaft is performed through the advanced angle hydraulic chambers by the acting torque in the direction of retarded angle.