Valve characteristics control apparatus

Abstract

A control valve part switches a flowing direction of working fluid between a first advance chamber and a first retard chamber in a timing adjustment mode, and restricts working fluid from flowing between the first advance chamber and the first retard chamber in a working angle adjustment mode. A check valve part allows working fluid to flow from a second retard chamber through a check passage to a second advance chamber, and restricts working fluid from flowing from the second advance chamber through the check passage to the second retard chamber. A switch valve part allows a communication between the second advance chamber and the second retard chamber through a switch passage in the working angle adjustment mode, and prohibits the communication between the second advance chamber and the second retard chamber through the switch passage in the timing adjustment mode.

1 . A valve characteristics control apparatus that controls valve characteristics of a valve opened and closed by a rotation of a camshaft in accordance with a rotation of a crankshaft in an internal combustion engine, the apparatus comprising:
 a housing rotating with the crankshaft;   a first vane rotor having a first vane rotatably received in the housing, a first advance chamber and a first retard chamber being defined by partitioning a space between the housing and the first vane in a rotation direction, the first vane rotor having a relative rotation with respect to the housing in an advance direction when working fluid is introduced into the first advance chamber and when working fluid is discharged from the first retard chamber, the first vane rotor having a relative rotation with respect to the housing in a retard direction when working fluid is discharged from the first advance chamber and when working fluid is introduced into the first retard chamber;   a control valve part that switches a flowing direction of working fluid between the first advance chamber and the first retard chamber in a timing adjustment mode adjusting valve timing as the valve characteristics, the control valve part restricting working fluid from flowing between the first advance chamber and the first retard chamber in a working angle adjustment mode adjusting a valve working angle as the valve characteristics;   a second vane rotor having a second vane rotating with the camshaft in a state that the second vane is projected into the first vane in the housing, a second advance chamber and a second retard chamber being defined by partitioning a space between the first vane and the second vane in the rotation direction, the second vane rotor having a relative rotation with respect to the first vane rotor in the advance direction when working fluid is introduced into the second advance chamber and when working fluid is discharged from the second retard chamber, the second vane rotor having a relative rotation with respect to the first vane rotor in the retard direction when working fluid is discharged from the second advance chamber and when working fluid is introduced into the second retard chamber;   a first check valve part having a check passage connecting the second advance chamber and the second retard chamber with each other, the check valve part allowing working fluid to flow from the second retard chamber through the check passage to the second advance chamber, the check valve part restricting working fluid from flowing from the second advance chamber through the check passage to the second retard chamber; and   a switch valve part having a switch passage connecting the second advance chamber and the second retard chamber with each other, the switch valve part allowing a communication between the second advance chamber and the second retard chamber through the switch passage in the working angle adjustment mode, the switch valve part prohibiting the communication between the second advance chamber and the second retard chamber through the switch passage in the timing adjustment mode.   
     
     
         2 . The valve characteristics control apparatus according to  claim 1 , wherein
 the control valve part restricts working fluid from flowing between the first advance chamber and the first retard chamber continuously from a start of the working angle adjustment mode to an end of the working angle adjustment mode.   
     
     
         3 . The valve characteristics control apparatus according to  claim 2 , wherein
 the valve is a plurality of exhaust valves having different valve opening timings.   
     
     
         4 . The valve characteristics control apparatus according to  claim 1 , wherein
 the control valve part restricts working fluid from flowing between the first advance chamber and the first retard chamber continuously to an end of the working angle adjustment mode, after working fluid is introduced into the first advance chamber and is discharged from the first retard chamber in response to a start of the working angle adjustment mode.   
     
     
         5 . The valve characteristics control apparatus according to  claim 4 , wherein
 the valve is an intake valve of the engine.   
     
     
         6 . The valve characteristics control apparatus according to  claim 1 , wherein
 the switch passage has a supply point to which working fluid is supplied, and   the switch valve part is located at a position adjacent to the second retard chamber rather than the supply point of the switch passage.   
     
     
         7 . The valve characteristics control apparatus according to  claim 6 , further comprising:
 a second check valve part having a supply passage that communicates with the supply point of the switch passage and a supply source of working fluid, wherein   the second check valve part allows working fluid to flow from the supply source to the supply point, and   the second check valve part prohibits working fluid from flowing from the supply point to the supply source.   
     
     
         8 . A valve characteristics control apparatus that controls valve characteristics of a valve opened and closed by a rotation of a camshaft in accordance with a rotation of a crankshaft in an internal combustion engine, the apparatus comprising:
 a housing rotating with the crankshaft;   a first vane rotor having a first vane rotatably received in the housing, a first advance chamber and a first retard chamber being defined by partitioning a space between the housing and the first vane in a rotation direction, the first vane rotor having a relative rotation with respect to the housing in an advance direction when working fluid is introduced into the first advance chamber and when working fluid is discharged from the first retard chamber, the first vane rotor having a relative rotation with respect to the housing in a retard direction when working fluid is discharged from the first advance chamber and when working fluid is introduced into the first retard chamber;   a control valve part that switches a flowing direction of working fluid between the first advance chamber and the first retard chamber in a timing adjustment mode adjusting valve timing as the valve characteristics, the control valve part restricting working fluid from flowing between the first advance chamber and the first retard chamber in a working angle adjustment mode adjusting a valve working angle as the valve characteristics;   a second vane rotor having a second vane rotating with the camshaft in a state that the second vane is projected into the first vane in the housing, a second advance chamber and a second retard chamber being defined by partitioning a space between the first vane and the second vane in the rotation direction, the second vane rotor having a relative rotation with respect to the first vane rotor in the advance direction when working fluid is introduced into the second advance chamber and when working fluid is discharged from the second retard chamber, the second vane rotor having a relative rotation with respect to the first vane rotor in the retard direction when working fluid is discharged from the second advance chamber and when working fluid is introduced into the second retard chamber;   a first check valve part having a check passage connecting the second advance chamber and the second retard chamber with each other, the check valve part allowing working fluid to flow from the second advance chamber through the check passage to the second retard chamber, the check valve part restricting working fluid from flowing from the second retard chamber through the check passage to the second advance chamber; and   a switch valve part having a switch passage connecting the second advance chamber and the second retard chamber with each other, the switch valve part allowing a communication between the second advance chamber and the second retard chamber through the switch passage in the working angle adjustment mode, the switch valve part prohibiting the communication between the second advance chamber and the second retard chamber through the switch passage in the timing adjustment mode.   
     
     
         9 . The valve characteristics control apparatus according to  claim 8 , wherein
 the control valve part restricts working fluid from flowing between the first advance chamber and the first retard chamber continuously from a start of the working angle adjustment mode to an end of the working angle adjustment mode.   
     
     
         10 . The valve characteristics control apparatus according to  claim 9 , wherein
 the valve is an intake valve of the engine.   
     
     
         11 . The valve characteristics control apparatus according to  claim 8 , wherein
 the control valve part restricts working fluid from flowing between the first advance chamber and the first retard chamber continuously to an end of the working angle adjustment mode, after working fluid is discharged from the first advance chamber and is introduced into the first retard chamber in response to a start of the working angle adjustment mode.   
     
     
         12 . The valve characteristics control apparatus according to  claim 11 , wherein
 the valve is a plurality of exhaust valves having different valve opening timings.   
     
     
         13 . The valve characteristics control apparatus according to  claim 8 , wherein
 the switch passage has a supply point to which working fluid is supplied, and   the switch valve part is located at a position adjacent to the second advance chamber rather than the supply point of the switch passage.   
     
     
         14 . The valve characteristics control apparatus according to  claim 13 , further comprising:
 a second check valve part having a supply passage that communicates with the supply point of the switch passage and a supply source of working fluid, wherein   the second check valve part allows working fluid to flow from the supply source to the supply point, and   the second check valve part prohibits working fluid from flowing from the supply point to the supply source.   
     
     
         15 . The valve characteristics control apparatus according to  claim 1 , wherein
 the first check valve part is located inside the second vane.