Patent ID: 8522734
Filing Date: 2013-09-03
Classification: F01L

Abstract:
1. A valve timing control device comprising: a driving side rotational member synchronously rotatable with a crankshaft of an internal combustion engine; a driven side rotational member arranged coaxially with the driving side rotational member and synchronously rotatable with a camshaft that controls an opening and closing operation of valves of the internal combustion engine; a fluid pressure chamber formed by the driving side rotational member and the driven side rotational member; a partition portion installed on at least one of the driving side rotational member and the driven side rotational member to partition the fluid pressure chamber into an advanced angle chamber and a retarded angle chamber; a lock member mounted in an accommodation portion formed in either the driving side rotational member or the driven side rotational member and protruding and withdrawing with respect to the rotational member opposite to the accommodation portion; a lock groove formed in the opposite rotational member so that the lock member protrudes and is locked to the lock groove, the lock groove confining a relative rotational phase of the driven side rotational member with respect to the driving side rotational member at a most advanced angle phase, a most retarded angle, or a predetermined phase between the most advanced angle phase and the most retarded angle when the lock member is locked; a lock release passage applying an operating fluid to the lock member to withdraw the lock member from the lock groove, wherein the lock release passage is in communication with the lock groove, the rotational member formed with the accommodation portion is provided with an atmosphere open passage which is in communication with the lock groove when the relative rotational phase is at a specific phase, wherein the atmosphere open passage is at an angular position different from the accommodation portion and does not include the lock member inside of the atmosphere open passage, the atmosphere open passage having a cross-section smaller than that of the lock release passage; and the hydraulic fluid discharged from the atmosphere open passage to outside the rotational member formed with the accommodation portion when the relative rotational phase is at the specific phase is greater than the hydraulic fluid discharged from the atmosphere open passage to outside the rotational member formed with the accommodation portion when the lock member is positioned in the lock groove.