Hydraulic valve timing controller

Abstract

An inner rotor has a support portion which directly supports a most inner winding portion of a coil spring from a radially inner direction at a specified angle position in the circumferential direction. The coil spring is formed by winding a wire in such a manner that adjacent windings are contact with each other at a specified angle position. The adjacent windings are separated by a distance at a position which is apart from the specified angle position in a circumferential direction.

1 . A hydraulic valve timing controller which adjusts valve timing of a valve that is opened/closed by a camshaft driven by a torque transmitted from a crankshaft of an internal combustion engine, comprising:
 an outer rotor rotating synchronously with the crankshaft;   an inner rotor rotating synchronously with the camshaft and defining an interior of the outer rotor into a plurality of working chambers into or from which a working fluid is introduced or discharged, whereby the inner rotor relatively rotates with respect to the outer rotor in one or the other circumferential direction thereof; and   a coil spring having a most outer winding portion and a most inner winding portion which are respectively engaged with the outer rotor and the inner rotor, the coil spring being spirally deformable in a deforming direction that is one of the circumferential directions in order to bias the inner rotor in a biasing direction that is the other circumferential direction, wherein:   the inner rotor has a support portion which directly supports the most inner winding portion from a radially inner direction at a specified angle position in the circumferential direction;   the coil spring has one end engaged with an engaging point of the outer rotor, the other end engaged with a supporting point of the support portion, and multiple windings of a wire in spiral form;   all adjacent windings of the wire are directly in contact with each other at the specified angle position; and   all adjacent windings of the wire are separated by a distance at a position which is apart from the specified angle position in the circumferential direction.   
     
     
         2 . A hydraulic valve timing controller according to  claim 1 , wherein
 the inner rotor has an axial portion which protrudes axially outwardly from an interior of the outer rotor;   the most inner winding portion is wound around the axial portion; and   the support portion is formed by a part of the axial portion which protrudes axially outwardly at the specified angle position.   
     
     
         3 . A hydraulic valve timing controller according to  claim 2 , wherein
 the most inner winding portion is wound around the axial portion from the support portion in the deforming direction so as to be engaged with the inner rotor; and   the most inner winding portion is apart from the support portion in the biasing direction.   
     
     
         4 . A hydraulic valve timing controller according to  claim 1 , wherein
 the inner rotor has a first support portion at the specified angle position and a second support portion which is located between adjacent windings of the wire at a position apart from the specified angle position in the circumferential direction in such a manner as to support the coil spring directly.   
     
     
         5 . A hydraulic valve timing controller according to  claim 4 , wherein
 the second support portion is located on a specified radial line which radially passes through the first support portion.   
     
     
         6 . A hydraulic valve timing controller according to  claim 5 , wherein
 the second support portion is located at one of clearances between adjacent windings on the specified radial line except at least one clearance on the specified radial line.   
     
     
         7 . A hydraulic valve timing controller according to  claim 1 , wherein
 the coil spring is configured in such a manner as to satisfy a following formula:
   Rno>T×N+Rsi
 
   wherein “T” represents a thickness of the wire in the radial direction,   “N” represents a number of windings of the wire at the specified angle position,   “Rsi” represents a radial distance between the supporting point of the support portion and a center of the coil spring that is in a set condition where the most outer winding portion and the most inner winding portion are respectively engaged with the outer rotor and the inner rotor, and   “Rno” represents a radial distance between a point corresponding to the specified angle position and the center of the coil spring that is in the free condition where the most outer winding portion and the most inner winding portion are respectively disengaged from the outer rotor and the inner rotor.   
     
     
         8 . A hydraulic valve timing controller according to  claim 7 , wherein
 when the coil spring is in the set condition, the engaging point of the outer rotor is located in an angle range which is defined between the specified angle position and an angle position which is advanced from the specified angle position by 90°.   
     
     
         9 . A hydraulic valve timing controller according to  claim 1 , wherein
 it is prohibited that the coil spring biases the inner rotor when a condition where the most winding portion is engaged with the outer rotor is changed to another condition where the most winding portion is engaged with the inner rotor;   all adjacent windings of the wire are directly in contact with each other at the specified angle position; and   all adjacent windings of the wire are separated by a distance at a position which is apart from the specified angle position in the circumferential direction.