| 摘要 |
PROBLEM TO BE SOLVED: To provide a valve timing adjustment device capable of suppressing degradation of accuracy in controlling a rotational phase of a vane rotor.SOLUTION: A valve body 44 has the bottomed cylindrical shape, and has a supply port 47 communicatable with an external supply oil passage 94 of a cam shaft 92, an advancing port 45 communicated with an advance chamber 33, and a retarding port 46 communicated with a retard chamber 34. The retarding port 46 is positioned at a bottom portion 72 side of the valve body 44 with respect to the advancing port 45. A spool 48 defines a drain space 52 with the valve body 44, and opens a retarding port 46 in discharging a hydraulic oil of the retard chamber 34 to the drain space 52. The supply port 47 includes a supply recess 78 as a part recessed radially outward from an inner wall surface 73 of the cylindrical portion 71 of the valve body 44. The retarding port 46 includes a retarding recess 76 as a part recessed radially outward from the inner wall surface 73. A radial depth H1 of the retarding recess 76 is shallower than a radial depth H2 of the supply recess 78.SELECTED DRAWING: Figure 8 |
