Title:
VARIABLE VALVE TIMING DEVICE
Document Type and Number:
Japanese Patent JPH04269309
Kind Code:
A
Abstract:
PURPOSE:To precisely hold a ring gear on a prescribed middle position and simplify an oil pressure channel, without complicate hydraulic control through control of opening/closing valves, and without detecting the relative position and the like of a pulley and a cam. CONSTITUTION:By moving a ring gear 9 by oil pressure to a pressure chamber and the energizating force due to a coil spring 13, valve timing is adjusted. A leak passage 27 capable of communicating an oil pan 15 to the pressure chamber is provided in a camshaft 2, a cylinder head 1, and the like, and a seal part is provided between the ring gear 9 and a timing pulley 5. The end part on the pressure chamber side of the leak passage 27 is opened facing to the seal part corresponding to the middle position in the moving range of the ring gear 9. On the way of the leak passage 27, a second hydraulic control valve 28 is provided, which closes the leak passage 27 at the maximum displacement of the ring gear 9 by oil pressure and opens the passage 27 at positioning on the middle part.
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Inventors:
MURAKAMI NOBUYUKI
MORITA SHUJI
MORITA SHUJI
Application Number:
JP2893591A
Publication Date:
September 25, 1992
Filing Date:
February 22, 1991
Export Citation:
Assignee:
TOYOTA MOTOR CORP
International Classes:
F01L1/34; (IPC1-7): F01L1/34
Attorney, Agent or Firm:
Hironobu Onda