Variable phaser for automobile engine

Abstract

In a variable phaser for an engine including a drive rotating member having a cylindrical section and driven by a crank shaft, a cam shaft coaxially supporting the drive rotating member in a coaxial and relatively rotating fashion, a relative phase angle changing mechanism, and a self-locking mechanism preventing the misalignment of the relative phase angle due to the cam torque by pressing the lock plate held on a holding section integral with the cam shaft to an inner circumferential surface of the cylindrical section, plate-pressing surfaces disposed at positions almost equally separated along an outer circumferential direction of an outer circumference of the holding section, and a plurality of lock plates equally separated in correspondence to the plate-pressing surfaces are formed, and the respective plate-pressing surfaces are formed by first and second pressing surfaces for delivering the cam torques along advance and lag directions to the respective lock plates.

1 . A variable phaser for an automobile engine comprising:
 a drive rotating member having a cylindrical section and driven by a crank shaft;
 a cam shaft supporting the drive rotating member in a coaxial and relatively rotating fashion; 
 a relative phase angle changing mechanism for changing an opening-closing timing of a valve by means of changing a relative phase angle of the cam shaft with respect to the drive rotating member; and 
 a self-locking mechanism including a holding section integrally formed in a shape of a flange on an outer periphery of the cam shaft, and a lock plate held to the cam shaft in a relative rotation disabling fashion by the holding section and contacted internally to an inner circumference surface of the cylindrical section, in which the holding section prevents misalignment of the relative phase angle by means of pressing the lock plate onto the inner circumference surface of the cylindrical section upon receipt of a cam torque generating along an advance direction or a lag direction, characterized in that: 
 plate-pressing surfaces pressing the lock plates are disposed at a plurality of positions almost equally separated along an outer circumferential direction of the holding section; 
 the lock plates are mounted the same number as the plate-pressing surfaces at a plurality of positions almost equally separated along an outer circumferential direction, and include pressure receiving sections at positions opposing to the plate-pressing surfaces; and 
 the plurality of the plate-pressing surfaces are configured by a first pressing surface pressing the lock plate upon receipt of the cam torque generating along the advance direction and a second pressing surface pressing the lock plate upon receipt of the cam torque generating along the lag direction. 
   
     
     
         2 . The variable phaser for the automobile engine as claimed in  claim 1 ,
 wherein each of the plate-pressing surfaces and the lock plates are disposed at three or more positions almost equally separated along the outer circumferential direction.   
     
     
         3 . The variable phaser for the automobile engine as claimed in  claim 1   wherein each of the first pressing surface and the second pressing surface are formed on the plate-pressing surface as two surfaces separated by a virtual surface passing a central shaft line of the cam shaft and perpendicular to the plate-pressing surface;   the pressure receiving sections include a first acting section to which a pressing force by the first pressing surface is exerted and a second acting section to which a pressing force by the second pressing surface is exerted; and   the first acting section and the second acting section are formed on the pressure receiving section such that a first distance from the virtual surface to the first acting section is different from a second distance from the virtual surface to the second acting section.   
     
     
         4 . The variable phaser for the automobile engine as claimed in  claim 3 ,
 wherein the first acting section and the second acting section are formed on the pressure receiving section such that the second distance is shorter than the first distance.   
     
     
         5 . The variable phaser for the automobile engine as claimed in  claim 3   wherein the pressure receiving section is mounted on the lock plate in a freely attaching and detaching fashion.