Patent ID: 8286601
Filing Date: 2012-10-16
Classification: F01L

Abstract:
1. A variable valve timing apparatus installed in a drive train for transmitting driving force from a drive shaft to a driven shaft which actuates at least one of an intake valve and an exhaust valve to adjust valve timing, the apparatus comprising: a housing having a peripheral wall, and side walls placed on both axial ends of the peripheral wall to define an accommodation chamber, the housing being rotatable with one of the drive shaft and the driven shaft; a vane rotor disposed in the accommodation chamber, the vane rotor being rotatable with the other one of the drive shaft and the driven shaft within a predetermined angular range in response to a pressure of fluid supplied to a pressure chamber defined within the accommodation chamber; and a restricting member for restricting relative rotation of the vane rotor with respect to the housing, a first chamber being defined between the restricting member and an inner wall of a holding hole, wherein one of the vane rotor and the housing define the holding hole which holds the restricting member in a manner that the restricting member is movable, wherein the other one of the vane rotor and the housing define an engaging hole which is able to be engaged with an end of the restricting member, wherein, when the engaging hole is located on an axis direction of the restricting member, the restricting member is moved into the engaging hole when the pressure of the fluid in the first chamber is lowered, and the restricting member is moved out of the engaging hole when a pressure of the fluid in the first chamber is raised, wherein the restricting member is formed in a hollow cylindrical shape which defines an equalizing passage capable of communicating the engaging hole and the holding hole to flow the fluid when the restricting member enters into the engaging hole, and wherein, when the engaging hole is located on the axis direction of the restricting member, the equalizing passage of the restricting member enables fluid to always flow between the engaging hole and the holding hole, irrespective of a position of the restricting member in the axis direction of the restricting member.