Device for Controlling Phase of Cam Shaft in Internal Combustion Engine and Phase Controlling device

Abstract

A device for controlling a phase of a cam shaft in an internal combustion engine has a structure which can return a phase of a cam shaft to an intermediate position on the basis of its own power by utilizing a variable torque applied to a cam shaft at a time of starting an engine so as to lock, and has a high practicability and mass production performance. This device is provided with a first rotating body rotating together with a cam shaft, a second rotating body provided coaxially in the first rotating body so as to control a phase angle and rotating together with a sprocket, and a fixing mechanism fixing the phase angle, in which the fixing mechanism has a wedge member wherein a wedge-shaped portion is formed, the first rotating body and the second rotating body have contact surfaces brought into contact with the wedge member, and at least any one of the contact surfaces of the first rotating body and the second rotating body is formed such that a distance from a center of rotation to an application line of a load applied to the contact surface is smaller than a distance from the center of rotation to an application point of the load on the contact surface.

1 . A device for controlling a phase of a cam shaft in an internal combustion engine comprising:
 a first rotating body rotating together with a sprocket;   a second rotating body provided coaxially in the first rotating body so as to control a phase angle and rotating together with the cam shaft; and   a fixing mechanism fixing phase angles of the first rotating body and the second rotating body,   wherein the fixing mechanism has a wedge member in which a wedge-shaped portion is formed,   wherein the first rotating body and the second rotating body have contact surfaces brought into contact with the wedge member, and   wherein at least any one of the contact surfaces of the first rotating body and the second rotating body is inclined with respect to a direction of a rotating axis of the first rotating body and the second rotating body, and is formed such that a distance from a center of rotation to an application line of a load applied to the contact surface is smaller than a distance from the center of rotation to an application point of the load on the contact surface.   
   
   
       2 . A device for controlling a phase of a cam shaft in an internal combustion engine as claimed in  claim 1 , wherein the contact surface is provided so as to be inclined with respect to a radial direction from the center of rotation of the first rotating body and the second rotating body, whereby the distance from the center of rotation to the application line is smaller than the distance from the center of rotation to the application point. 
   
   
       3 . A device for controlling a phase of a cam shaft in an internal combustion engine comprising:
 a first rotating body rotating together with a sprocket;   a second rotating body provided coaxially in the first rotating body so as to control a phase angle and rotating together with the cam shaft; and   a fixing mechanism fixing phase angles of the first rotating body and the second rotating body,   wherein the fixing mechanism has a wedge member n which a wedge-shaped portion is formed,   wherein the first rotating body and the second rotating body have receiving portions brought into contact with the wedge member,   wherein the receiving portions of the first rotating body and the second rotating body are respectively provided with contact surfaces which are narrowed with each other in an inserting direction of the wedge member, and   wherein at least any one contact surface of the contact surfaces is inclined with respect to a direction of a rotating axis of the first rotating body and the second rotating body, and is inclined with respect to a radial direction from a center of rotation of the first rotating body and the second rotating body.   
   
   
       4 . A device for controlling a phase of a cam shaft in an internal combustion engine as claimed in  claim 3 , wherein the fixing mechanism has an elastic member energizing the wedge member in the inserting direction to the contact surfaces, and a hydraulic mechanism generating a hydraulic force in a direction of pulling out the wedge member from the contact surfaces. 
   
   
       5 . A device for controlling a phase of a cam shaft in an internal combustion engine as claimed in  claim 3 , wherein the first rotating body has an inner peripheral surface having a predetermined radius, the second rotating body has an outer peripheral surface having a predetermined radius, the first rotating body and the second rotating body are arranged such that the inner peripheral surface and the outer peripheral surface oppose to each other, the receiving portion of the first rotating body is provided in a side in which a diameter becomes larger than the inner peripheral surface, and the receiving portion of the second rotating body is provided in a side in which a diameter becomes smaller than the outer peripheral surface. 
   
   
       6 . A device for controlling a phase of a cam shaft in an internal combustion engine as claimed in  claim 1 , wherein the first rotating body and the second rotating body have a second pair of contact surfaces which limit the phase angle in an inverse direction to a direction in which the phase angle is limited by a pair of contact surfaces provided in the first rotating body and the second rotating body and the wedge-shaped body, the second pair of contact surfaces limit the phase angle by being brought into contact via the intermediate member, and one of the second pair of contact surfaces is provided with a step portion enlarging a regulating range of the phase angle limited by the second pair of contact surfaces. 
   
   
       7 . A device for controlling a phase of a cam shaft in an internal combustion engine as claimed in  claim 1 , wherein the contact surfaces are formed with an angle equal to or less than 11 degree with respect to an inserting direction of the wedge member. 
   
   
       8 . A phase controlling device having a first rotating member and a second rotating member rotationally driven via the first rotating member, and controlling a phase angle corresponding to a relative rotational position between the first rotating member and the second rotating member,
 wherein a drive member spark advance surface heading for a rotating direction of a whole of the device is formed in a drive side member in a power transmitting path from the first rotating member to the second rotating member,   wherein a driven member phase lag surface heading for an inverse direction to the rotating direction of the whole of the device is formed in a driven side member in the power transmitting path,   wherein one of the drive member spark advance surface and the driven member phase lag surface is inclined so as to head for an inner peripheral side within an axial vertical cross section with respect to a radial direction, and the other is inclined so as to head for an outer peripheral side within the axial vertical cross section,   wherein the device is provided with a wedge member sandwiched between the drive member spark advance surface and the driven member phase lag surface by the second rotating member changing the phase angle in the phase angle direction with respect to the first rotating member, an energizing means for energizing the wedge member to one of the directions of the rotating axes of the first rotating member and the second rotating member and a driving means for moving to the other of the directions of the rotating axes, and   wherein a distance between the drive member spark advance surface and the driven member phase lag surface in each of the axial vertical cross sections is made smaller to a cross section in an energizing direction by the energizing means.   
   
   
       9 . A phase controlling device as claimed in  claim 8 , wherein the drive member spark advance surface is arranged in one of inner and outer sides of a cylinder surface having a predetermined radius, and the driven member phase lag surface is arranged in the other side.