Title:
VALVE TIMING CONTROL DEVICE FOR ENGINE
Document Type and Number:
Japanese Patent JPH02245408
Kind Code:
A
Abstract:
PURPOSE:To enable the change of valve timing in a low revolution range to be carried out, in an engine in which the intake and exhaust timing is changed by a hydraulic actuator, by providing a means by which the oil pressure to be supplied to the hydraulic actuator is maintained when the engine speed is in a low revolution range. CONSTITUTION:In a valve-timing changing mechanism 30, when a changeover solenoid 31 is turned on to change over a changeover valve 52 to the supply position, a piston 38 is shifted toward the right by the pressure oil supplied to a pressure chamber 49 through an oil passage 45 against a spring 44. Thereby a spacer 32 and a pulley 7 which are fitted to the splines 40, 41 formed on the inner and outer circumferences of the piston 38 in the reverse directions to each other are relatively turned, and the relative position of a camshaft 5 being integral with the spacer 32 and the pulley 7 is changed. In this case, a check valve 58 (an oil pressure maintaining means) which consists of a steel ball 56 and a spring 57, and which allows only the pressure oil flow from the upstream side, is provided in the oil passage 54 on the upstream side of the changeover valve 52, so that the oil pressure to be supplied to a pressure chamber 49 can be maintained in the low revolution range of the engine.
Inventors:
SASAKI JUNZO
NISHIKAWA TOSHIO
FUJIMOTO HIDEFUMI
NISHIKAWA TOSHIO
FUJIMOTO HIDEFUMI
Application Number:
JP6697189A
Publication Date:
October 01, 1990
Filing Date:
March 17, 1989
Export Citation:
Assignee:
MAZDA MOTOR
International Classes:
F01L1/34; F01L13/00; (IPC1-7): F01L1/34; F01L13/00
Attorney, Agent or Firm:
Toshio Okamura