Valve timing control apparatus and internal combustion engine

Abstract

A valve timing control apparatus includes a driving rotary member driven by an engine, and a driven rotary member to drive a camshaft of the engine. The driven member is rotatable relative to the driving rotary member. A first movable member is provided in one of the rotary members, and arranged to move forwards and backwards. A second movable member is provided in the other of the rotary members, and arranged to move forwards and backwards. The first and second movable members are arranged to limit a relative rotation between the driving rotary member and the driven rotary member when both the first movable member and the second movable member are moved forwards, and to allow the relative rotation when at least one of the first and second movable members is moved backwards.

1 . A valve timing control apparatus for an internal combustion engine, comprising: 
 a driving rotary member adapted to be driven by the engine;    a driven rotary member arranged to rotate relative to the driving rotary member and adapted to rotate a camshaft of the engine;    a first movable member provided in a first rotary member, and arranged to move forwards and backwards, the first rotary member being one of the driving rotary member and the driven rotary member; and    a second movable member provided in a second rotary member and arranged to move forwards and backwards, the second rotary member being the other of the driving rotary member and the driven rotary member,    the first and second movable members being arranged to limit a relative rotation between the driving rotary member and the driven rotary member when both the first movable member and the second movable member are moved forwards, and to allow the relative rotation between the driving rotary member and the driven rotary member when at least one of the first and second movable members is moved backwards.    
   
   
       2 . The valve timing control apparatus as claimed in  claim 1 , wherein the driving rotary member is adapted to be driven by a crankshaft of the engine; the driven rotary member is adapted to rotate as a unit with the camshaft; and the valve timing control apparatus further comprises: 
 a first bias member arranged to bias the first movable member forwards toward the second rotary member;    a second bias member arranged to bias the second movable member forwards toward the first rotary member; and    a control section to alter a relative rotational position of the driven rotary member relative to the driving rotary member.    
   
   
       3 . The valve timing control apparatus as claimed in  claim 1 , wherein the valve timing control apparatus further comprises a first bias member arranged to bias the first movable member to move the first movable member forwards toward the second movable member, and a second bias member arranged to bias the second movable member to move the second movable member forwards toward the first movable member; and wherein the first movable member and second movable member are arranged to abut against each other to limit the relative rotation between the driving rotary member and the driven rotary member when the first and second movable members are projected forwards.  
   
   
       4 . The valve timing control apparatus as claimed in  claim 3 , wherein the valve timing control apparatus further comprises an actuating device to force at least one of the first and second movable members backwards to allow the relative rotation between the driving rotary member and the driven rotary member.  
   
   
       5 . The valve timing control apparatus as claimed in  claim 3 , wherein the first and second movable members are so arranged that the first and second movable members are moved forwards to limit the relative rotation between the driving rotary member and the driven rotary member at the time of start of the engine, and that at least one of the first and second movable members is moved backwards to allow the relative rotation between the driving rotary member and the driven rotary member after the start of the engine.  
   
   
       6 . The valve timing control apparatus as claimed in  claim 3:   wherein the driving rotary member and the driven rotary member are arranged to define an advance fluid pressure chamber to rotate the driven rotary member in an advance direction relative to the driving rotary member when an advance fluid pressure is supplied to the advance fluid pressure chamber, and a retard fluid pressure chamber to rotate the driven rotary member in a retard direction relative to the driving member when a retard fluid pressure is supplied to the retard fluid pressure chamber; and    wherein at least one of the first and second movable members is arranged to move backwards in accordance with one of the advance fluid pressure and the retard fluid pressure.    
   
   
       7 . The valve timing control apparatus as claimed in  claim 6 , wherein the driven rotary member includes a vane projecting radially outwards and separating the advance fluid pressure chamber and the retard fluid pressure chamber; and the driving rotary member enclosing the driven rotary member and defining the advance and retard fluid pressure chambers between the driving rotary member and the driven rotary member.  
   
   
       8 . The valve timing control apparatus as claimed in  claim 6 , wherein at least one of the first and second movable members is bared in one of the advance fluid pressure chamber and the retard fluid pressure chamber to move backwards in accordance with one of the advance fluid pressure and the retard fluid pressure.  
   
   
       9 . The valve timing control apparatus as claimed in  claim 6 , wherein at least one of the driving rotary member and the driven rotary member is formed with a communication passage to convey one of the advance fluid pressure and the retard fluid pressure to move one of the first and second movable members backwards.  
   
   
       10 . The valve timing control apparatus as claimed in  claim 6 , wherein the first movable member is arranged to move backwards in accordance with the advance fluid pressure against a biasing force of the first bias member; and the second movable member is arranged to move backwards in accordance with the retard fluid pressure against a biasing force of the second bias member.  
   
   
       11 . The valve timing control apparatus as claimed in  claim 6 , wherein the first movable member is arranged to move backwards in accordance with one of the advance fluid pressure and the retard fluid pressure against a biasing force of the first bias member; and the second movable member is arranged to move backwards in a radial outward direction by a centrifugal force.  
   
   
       12 . The valve timing control apparatus as claimed in  claim 6 , wherein the first and second movable members are both exposed to a hydraulic pressure in one of the advance fluid pressure chamber and the retard fluid pressure chamber; and the first movable member is arranged to be forced backwards by the hydraulic pressure whereas the second movable member is not forced by the hydraulic pressure.  
   
   
       13 . The valve timing control apparatus as claimed in  claim 12 , wherein the first movable member includes a forward end portion arranged to receive the hydraulic pressure only on a forward side to be pushed backwards by the hydraulic pressure; and the second movable member includes a forward end portionformed with a through hole so that the second movable member receives the hydraulic pressure on both of a forward side and a back side of the second movable member.  
   
   
       14 . The valve timing control apparatus as claimed in  claim 6 , wherein one of the first and second movable members includes an outside circumferential surface and a pressure receiving outward flange surface which projects outwards from the outside circumferential surface and which is arranged to receive one of the advance fluid pressure and the retard fluid pressure.  
   
   
       15 . The valve timing control apparatus as claimed in  claim 14 , wherein the second movable member includes the pressure receiving outward flange surface which is annular; and the second rotary member includes a portion defining an annular pressure chamber which is formed around the second movable member, and which is connected with one of the advance fluid pressure chamber and the retard fluid pressure chamber.  
   
   
       16 . The valve timing control apparatus as claimed in  claim 3 , wherein one of the first and second movable members includes a projection and the other of the first and second movable members includes a recess to receive the projection to limit the relative rotation between the driving and driven rotary members when the first and second movable members are moved forwards toward each other.  
   
   
       17 . The valve timing control apparatus as claimed in  claim 3 , wherein the first rotary member includes a support portion supporting the first movable member and allowing the first movable member to move radially around an axis of the camshaft; and the second rotary member includes a support portion supporting the second movable member and allowing the second movable member to move radially around the axis of the camshaft.  
   
   
       18 . The valve timing control apparatus as claimed in  claim 3 , wherein the first rotary member includes a support portion supporting the first movable member and allowing the first movable member to move axially along an axis of the camshaft; and the second rotary member includes a support portion supporting the second movable member and allowing the second movable member to move axially along the axis of the camshaft.  
   
   
       19 . The valve timing control apparatus as claimed in  claim 1 , wherein the first and second movable member are arranged to move into a lock state to prevent the relative rotation between the driving and driven rotary members when the driven member is at a predetermined first rotational position relative to the driving member, and at least one of the first and second movable members is arranged to be moved backwards by a relative rotation of the driven member relative to the driving member from a second rotational position away from the predetermined first rotational position, to the predetermined first rotational position.  
   
   
       20 . The valve timing control apparatus as claimed in  claim 19 , wherein the valve timing control apparatus further comprises a guide portion to guide the first and second movable members into the lock state when the driven rotary member rotates from a rotational position away from the first rotational position, to the first rotational position relative to the driving member with at least one of the first and second movable members being projected forwards.  
   
   
       21 . The valve timing control apparatus as claimed in  claim 20 , wherein the guide portion is arranged to guide the first and second movable members into the lock state by receiving an operating force produced when the crankshaft of the engine is rotating.  
   
   
       22 . The valve timing control apparatus as claimed in  claim 19 , wherein one of the first and second movable members is formed with a guide portion to guide the first and second movable members into the lock state when the driven rotary member rotates from a rotational position away from the first rotational position, to the first rotational position relative to the driving member.  
   
   
       23 . The valve timing control apparatus as claimed in  claim 19 , wherein the first and second movable members includes, respectively, first and second abutting portions which are arranged to abut against each other when the driven rotary member rotates from a rotational position away from the first rotational position toward the first rotational position relative to the driving member with the first and second movable members are projected forwards; and at least one of the first and second abutting portions includes an inclined surface to guide the first and second movable members into the lock position.  
   
   
       24 . The valve timing control apparatus as claimed in  claim 23 , wherein one of the first and second abutting portions includes the inclined surface which is a tapered surface, and the other of the first and second abutting portions includes a non-tapered surface abutting on the tapered surface.  
   
   
       25 . The valve timing control apparatus as claimed in  claim 2 , wherein the valve timing control apparatus further comprises a control section to alter a rotational position of the driven rotary member relative to the driving rotary member.  
   
   
       26 . The valve timing control apparatus as claimed in  claim 25 , wherein the control section includes a hydraulic section to rotate the driven rotary member in an advance direction relative to the driving rotary member by supplying an advance fluid pressure to an advance chamber, and to rotate the driven rotary member in a retard direction relative to the driving rotary member by supplying a retard fluid pressure to a retard chamber; the first movable member is arranged to move backwards in accordance with the advance fluid pressure against a biasing force of the first bias member; and the second movable member is arranged to move backwards in accordance with the retard fluid pressure against a biasing force of the first bias member.  
   
   
       27 . The valve timing control apparatus as claimed in  claim 26 , wherein one of the first and second bias members is a spring so set as to allow the movable member biased by the spring, to move backwards when a hydraulic pressure is applied the movable member biased by the spring, and as to prevent a backward movement of the movable member biased by the spring when a pressure of air is applied; and wherein the movable member biased, by the spring is acted upon by a hydraulic pressure which is one of the advance fluid pressure and the retard fluid pressure and which is supplied to a corresponding one of the advance fluid chamber and the retard fluid chamber first after the engine is started.  
   
   
       28 . The valve timing control apparatus as claimed in  claim 26 , wherein one of the first and second bias members is a greater bias member having a biasing force greater than a biasing force of the other of the first and second bias members; and wherein the movable member biased by the greater bias member is acted upon by a hydraulic pressure which is one of the advance fluid pressure and the retard fluid pressure and which is supplied to a corresponding one of the advance fluid chamber and the retard fluid chamber first after the engine is started.  
   
   
       29 . The valve timing control apparatus as claimed in  claim 25 , wherein the control section includes a controller to cause the first and second movable members to move forwards to limit the relative rotation between the driving rotary member and the driven rotary member at the time of start of the engine, and to cause at least one of the first and second movable members to be moved backwards to allow the relative rotation between the driving rotary member and the driven rotary member after the start of the engine.  
   
   
       30 . The valve timing control apparatus as claimed in  claim 3 , wherein the first movable member is arranged to move backwards against a biasing force of the first bias member in accordance with a fluid pressure produced by a fluid pump driven by the engine; and the second movable member is arranged to move backwards against a biasing force of the first bias member in accordance with a fluid pressure produced by the fluid pump.  
   
   
       31 . An internal combustion engine comprising: 
 a crankshaft;    a camshaft;    a valve timing control rotary mechanism including, 
 a driving rotary member driven by the crankshaft of the engine, and  
 a driven rotary member) which is arranged to be driven by the driving rotary member and to drive the camshaft, and which is arranged to rotate relative to the driving rotary member to alter a rotational position of the driven rotary member relative to the driving rotary member; and  
   a lock mechanism including, 
 a first movable member mounted in the driven rotary member and arranged to move forwards toward the driving rotary member and backwards away from the driving rotary member, and  
 a second movable member mounted in the driving rotary member and arranged to move forwards toward the driven rotary member and backwards away from the driven rotary member, the second movable member being arranged to abut against the first movable member and thereby to limit a relative rotation between the driving rotary member and the driven rotary member when both the first movable member and the second movable member are moved forwards.