Variable valve apparatus

Abstract

An arm coupling mechanism for selectively switching a double valve variable control and single valve variable control. The single valve variable control is achieved in a condition in which a large lift arm and a second rocking cam arm are coupled together with a pin. The second rocking cam arm for moving a second valve includes a pin hole, in which the pin is inserted, formed therein. The position of the pin hole is set so that a pin switching operation can be executed when control is provided to achieve an operating angle, at which the single valve variable control is to be started for reduced NOx. A second driving cam is adapted to have a cam height greater than a cam height of a first driving cam.

1 - 8 . (canceled) 
   
   
       9 . A variable valve apparatus in which control on valve-opening characteristics of at least one valve to be switched of a plurality of valves is changed from that under a variable control mode to that under a fixed control mode or vice versa, the variable valve apparatus comprising:
 a rocking member interposed between a main cam and the valve, the rocking member transmitting a pressing force of the main cam to the valve;   valve-opening characteristics variable means for controlling a posture of the rocking member within a predetermined range to variably control valve-opening characteristics of the valve to be switched;   valve-opening characteristics fixing means for fixedly controlling the valve-opening characteristics of the valve to be switched; and   changing means for switching control on the valve-opening characteristics of the valve to be switched from that under the variable control mode to that under the fixed control mode or vice versa;   wherein the changing means allows the valve-opening characteristics of the valve to be switched to be changed in a posture of the rocking member associated with an operating range requiring a switch of the valve-opening characteristics of the valve to be switched.   
   
   
       10 . The variable valve apparatus according to  claim 9 ,
 wherein an operating range requiring a switch of the valve-opening characteristics of the valve to be switched includes a low engine speed range or a light load range for reduced NOx or improved fuel economy.   
   
   
       11 . The variable valve apparatus according to  claim 9 ,
 wherein the valve-opening characteristics variable means includes an intermediate member disposed between the main cam and the valve to be switched and control means for changing a position of the intermediate member;   wherein the intermediate member is shared among the plurality of valves including the valve to be switched;   including a second cam that is separate from the main cam;   wherein the valve-opening characteristics fixing means includes an input arm that rocks in phase with rotation of the second cam;   wherein the changing means engages or disengages coupling between the rocking member for moving the valve to be switched and the input arm; and   wherein the second cam is configured to have a greater cam height than the main cam.   
   
   
       12 . The variable valve apparatus according to  claim 11 ,
 wherein the changing means is configured such that, when the operating range requiring a switch of the valve-opening characteristics of the valve to be switched exists over a predetermined range, the valve-opening characteristics of the valve to be switched can be switched with the rocking member in a posture that achieves the minimum operating angle and/or lift of the valve to be switched within the predetermined range.   
   
   
       13 . The variable valve apparatus according to  claim 11 ,
 wherein the changing means is configured such that, when the operating range requiring a switch of the valve-opening characteristics of the valve to be switched exists over a predetermined range, the valve-opening characteristics of the valve to be switched can be switched with the rocking member in a posture that achieves the maximum operating angle and/or lift of the valve to be switched within the predetermined range.   
   
   
       14 . The variable valve apparatus according to  claim 9 ,
 wherein the valve-opening characteristics variable means includes an intermediate member disposed between the main cam and the valve to be switched and control means for changing a position of the intermediate member;   wherein the intermediate member is shared among the plurality of valves including the valve to be switched;   including a second cam that is separate from the main cam;   wherein the valve-opening characteristics fixing means includes an input arm that rocks in phase with rotation of the second cam;   wherein the changing means includes a pin, the changing means engaging or disengaging coupling of the pin between the rocking member for moving the valve to be switched and the input arm;   wherein either the rocking member for moving the valve to be switched or the input arm includes a pin hole, in which the pin is inserted; and   wherein an entrance portion of the pin hole includes a guide surface formed for guiding the pin being inserted into, or moved out of, the pin hole.   
   
   
       15 . The variable valve apparatus according to  claim 14 ,
 wherein the guide surface has an inclined angle relative to an axis of the pin hole, the angle becoming smaller toward an entrance portion of the pin hole.   
   
   
       16 . The variable valve apparatus according to  claim 11 ,
 wherein a profile of the second cam is configured such that the second cam achieves a phase of the valve to be switched different from a valve phase achieved by the main cam.   
   
   
       17 . A variable valve apparatus in which control on valve-opening characteristics of at least one valve to be switched of a plurality of valves is changed from that under a variable control mode to that under a fixed control mode or vice versa, the variable valve apparatus comprising:
 a rocking member interposed between a main cam and the valve, the rocking member transmitting a pressing force of the main cam to the valve;   valve-opening characteristics variable means for controlling a posture of the rocking member within a predetermined range to variably control valve-opening characteristics of the valve to be switched;   valve-opening characteristics fixing means for fixedly controlling the valve-opening characteristics of the valve to be switched; and   changing means for switching control on the valve-opening characteristics of the valve to be switched from that under the variable control mode to that under the fixed control mode or vice versa;   wherein the changing means allows the valve-opening characteristics of the valve to be switched to be changed in a posture of the rocking member associated with an operating range requiring a switch of the valve-opening characteristics of the valve to be switched;   wherein the operating range requiring a switch of the valve-opening characteristics of the valve to be switched is an operating range, in which an operating angle of the valve to be switched is substantially 100 to 200° C.A.   
   
   
       18 . A variable valve apparatus in which control on valve-opening characteristics of at least one valve to be switched of a plurality of valves is changed from that under a variable control mode to that under a fixed control mode or vice versa, the variable valve apparatus comprising:
 a rocking member interposed between a main cam and the valve, the rocking member transmitting a pressing force of the main cam to the valve;   valve-opening characteristics variable means for controlling a posture of the rocking member within a predetermined range to variably control valve-opening characteristics of the valve to be switched;   valve-opening characteristics fixing means for fixedly controlling the valve-opening characteristics of the valve to be switched; and   changing means for switching control on the valve-opening characteristics of the valve to be switched from that under the variable control mode to that under the fixed control mode or vice versa;   wherein the changing means allows the valve-opening characteristics of the valve to be switched to be changed in a posture of the rocking member associated with an operating range requiring a switch of the valve-opening characteristics of the valve to be switched;   wherein the valve-opening characteristics variable means includes an intermediate member disposed between the main cam and the valve to be switched and control means for changing a position of the intermediate member;   wherein the intermediate member being shared among the plurality of valves includes the valve to be switched;   including a second cam that is separate from the main cam;   wherein the valve-opening characteristics fixing means includes an input arm that rocks in phase with rotation of the second cam;   wherein the changing means includes a pin, the changing means engaging or disengaging coupling of the pin between the rocking member for moving the valve to be switched and the input arm;   wherein either the rocking member for moving the valve to be switched or the input arm includes a pin hole, in which the pin is inserted; and   wherein an entrance portion of the pin hole includes a guide surface formed for guiding the pin being inserted into, or moved out of, the pin hole.   
   
   
       19 . The variable valve apparatus according to  claim 18 ,
 wherein an operating range requiring a switch of the valve-opening characteristics of the valve to be switched includes a low engine speed range or a light load range for reduced NOx or improved fuel economy.   
   
   
       20 . The variable valve apparatus according to  claim 18 ,
 wherein the guide surface has an inclined angle relative to an axis of the pin hole, the angle becoming smaller toward an entrance portion of the pin hole.   
   
   
       21 . The variable valve apparatus according to  claim 18 ,
 wherein a profile of the second cam is configured such that the second cam achieves a phase of the valve to be switched different from a valve phase achieved by the main cam.   
   
   
       22 . A variable valve apparatus in which control on valve-opening characteristics of at least one valve to be switched of a plurality of valves is changed from that under a variable control mode to that under a fixed control mode or vice versa, the variable valve apparatus comprising:
 a rocking member interposed between a main cam and the valve, the rocking member transmitting a pressing force of the main cam to the valve;   valve-opening characteristics variable means for controlling a posture of the rocking member within a predetermined range to variably control valve-opening characteristics of the valve to be switched;   valve-opening characteristics fixing means for fixedly controlling the valve-opening characteristics of the valve to be switched;   changing means for switching control on the valve-opening characteristics of the valve to be switched from that under the variable control mode to that under the fixed control mode or vice versa; and   a second cam that is separate from the main cam;   wherein the changing means allows the valve-opening characteristics of the valve to be switched to be changed in a posture of the rocking member associated with an operating range requiring a switch of the valve-opening characteristics of the valve to be switched;   wherein a profile of the second cam is configured such that the second cam achieves a phase of the valve to be switched different from a valve phase achieved by the main cam.   
   
   
       23 . A variable valve apparatus in which control on valve-opening characteristics of at least one valve to be switched of a plurality of valves is changed from that under a variable control mode to that under a fixed control mode or vice versa, the variable valve apparatus comprising:
 a rocking member interposed between a main cam and the valve, the rocking member transmitting a pressing force of the main cam to the valve;   a valve-opening characteristics variable unit for controlling a posture of the rocking member within a predetermined range to variably control valve-opening characteristics of the valve to be switched;   a valve-opening characteristics fixing unit for fixedly controlling the valve-opening characteristics of the valve to be switched; and   a changing unit for switching control on the valve-opening characteristics of the valve to be switched from that under the variable control mode to that under the fixed control mode or vice versa;   wherein the changing unit allows the valve-opening characteristics of the valve to be switched to be changed, in a condition, in which the rocking member is controlled by the valve-opening characteristics variable unit so that the rocking member is in a posture that is associated with an operating range requiring a switch of the valve-opening characteristics of the valve to be switched and excepts a posture for achieving a maximum or minimum value in the variable range of operating angle and/or lift of the valve to be switched.   
   
   
       24 . A variable valve apparatus in which control on valve-opening characteristics of at least one valve to be switched of a plurality of valves is changed from that under a variable control mode to that under a fixed control mode or vice versa, the variable valve apparatus comprising:
 a rocking member interposed between a main cam and the valve, the rocking member transmitting a pressing force of the main cam to the valve;   a valve-opening characteristics variable unit for controlling a posture of the rocking member within a predetermined range to variably control valve-opening characteristics of the valve to be switched;   a valve-opening characteristics fixing unit for fixedly controlling the valve-opening characteristics of the valve to be switched; and   a changing unit for switching control on the valve-opening characteristics of the valve to be switched from that under the variable control mode to that under the fixed control mode or vice versa;   wherein the changing unit allows the valve-opening characteristics of the valve to be switched to be changed in a posture of the rocking member associated with an operating range requiring a switch of the valve-opening characteristics of the valve to be switched;   wherein the operating range requiring a switch of the valve-opening characteristics of the valve to be switched is an operating range, in which an operating angle of the valve to be switched is substantially 100 to 200° C.A.   
   
   
       25 . A variable valve apparatus in which control on valve-opening characteristics of at least one valve to be switched of a plurality of valves is changed from that under a variable control mode to that under a fixed control mode or vice versa, the variable valve apparatus comprising:
 a rocking member interposed between a main cam and the valve, the rocking member transmitting a pressing force of the main cam to the valve;   a valve-opening characteristics variable unit for controlling a posture of the rocking member within a predetermined range to variably control valve-opening characteristics of the valve to be switched;   a valve-opening characteristics fixing unit for fixedly controlling the valve-opening characteristics of the valve to be switched; and   a changing unit for switching control on the valve-opening characteristics of the valve to be switched from that under the variable control mode to that under the fixed control mode or vice versa;   wherein the changing unit allows the valve-opening characteristics of the valve to be switched to be changed in a posture of the rocking member associated with an operating range requiring a switch of the valve-opening characteristics of the valve to be switched;   wherein the valve-opening characteristics variable unit includes an intermediate member disposed between the main cam and the valve to be switched and a control unit for changing a position of the intermediate member;   wherein the intermediate member is shared among the plurality of valves including the valve to be switched;   including a second cam that is separate from the main cam;   wherein the valve-opening characteristics fixing unit includes an input arm that rocks in phase with rotation of the second cam;   wherein the changing unit includes a pin, the changing unit engaging or disengaging coupling of the pin between the rocking member for moving the valve to be switched and the input arm;   wherein either the rocking member for moving the valve to be switched or the input arm includes a pin hole, in which the pin is inserted; and   wherein an entrance portion of the pin hole includes a guide surface formed for guiding the pin being inserted into, or moved out of, the pin hole.   
   
   
       26 . A variable valve apparatus in which control on valve-opening characteristics of at least one valve to be switched of a plurality of valves is changed from that under a variable control mode to that under a fixed control mode or vice versa, the variable valve apparatus comprising:
 a rocking member interposed between a main cam and the valve, the rocking member transmitting a pressing force of the main cam to the valve;   a valve-opening characteristics variable unit for controlling a posture of the rocking member within a predetermined range to variably control valve-opening characteristics of the valve to be switched;   a valve-opening characteristics fixing unit for fixedly controlling the valve-opening characteristics of the valve to be switched;   a changing unit for switching control on the valve-opening characteristics of the valve to be switched from that under the variable control mode to that under the fixed control mode or vice versa; and   a second cam that is separate from the main cam;   wherein the changing unit allows the valve-opening characteristics of the valve to be switched to be changed in a posture of the rocking member associated with an operating range requiring a switch of the valve-opening characteristics of the valve to be switched;   wherein a profile of the second cam is configured such that the second cam achieves a phase of the valve to be switched different from a valve phase achieved by the main cam.