| 摘要 |
PROBLEM TO BE SOLVED: To improve control responsiveness by providing a restraining means for restraining discharge of lubricating oil from a first hydraulic chamber 26 during supply of lubricating oil to a second hydraulic chamber 27, in a device for changing actuation timing by supplying and discharging lubricating oil to the first and second hydraulic chambers. SOLUTION: When duty ratio of exciting voltage impressed on a solenoid 53 of an oil control valve 44, an exchange and restraining means, a spool 52 moves left against a spring 62, and a first delivery port 55 is moved to communicate with a supply port 54. Therefore, lubricating oil is supplied to a first hydraulic chamber 26 through oil passages 8, 28, and a ring gear 25 is pressed onto the axial direction. Because lapping widthsδ2,δ3 between a sleeve 51 and valve elements 63, 64 are in the relationδ2>δ3, a second delivery port 56 is not yet opened and movement of the ring gear 25 is restrained. As the duty ratio is furthermore increased, the second delivery port 56 is set to communicate with a drain port 58, and angle of a valve timing proceeds through the movement of the ring gear 25.
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