| 摘要 |
<p>PURPOSE:To show high responsiveness in response to control without being generating back flash noise by providing a recessed part for receiving control oil pressure so as to change abrasion force of a sliding surface according to the magnitude of control oil pressure and deform a seal ring in radial direction, in the seal ring. CONSTITUTION:In a seal ring 17, oil which is pressurized in oil pressure chambers 11, 14 is received in recessed parts 17d, 17e, so that oil pressure which is shown by the arrow is received, the rim 17a of the outside is push-pressed in radial direction outer side, and it is pushed down on the inner surface of a hydraulic cylinder 4a. Simultaneously, the rim 17b of an inner side is push- pressed in radial direction inner side, and it is pushed on the outer circumference of an annular groove 12d. As a result, braking force of axial direction according to the magnitude of control oil pressure acts from the side of the hydraulic cylinder 4a in relation to the piston 12. Vibration of the piston 12 is thus suppressed, and back lash noise is prevented. Also, responsiveness of a variable valve timing is not reduced.</p> |
