US 2009/0151671 A1 · CONTROLLER FOR VANE-TYPE VARIABLE TIMING ADJUSTING MECHANISM

Abstract

One-way valves (30, 31) are provided in a hydraulic supply passage (28) in an advance chamber (18) and a hydraulic supply passage (29) in a retard chamber (19) respectively for preventing reverse flow of oil from each chamber (18, 19) and drain oil passages (32, 33) bypassing the one-way valves respectively disposed in the hydraulic supply passages (28, 29) of the respective hydraulic chambers (18, 19) are provided to be in parallel therewith. Drain switching valves (34, 35) are disposed in the respective drain oil passages (32, 33). A hydraulic control valve (21) for controlling a hydraulic pressure supplied to the advance chamber (18) and the retard chamber (19) includes integrally a drain switching control function (38) for controlling a hydraulic pressure supplied to the respective drain switching valves (34, 35). A point where a VCT response speed rapidly changes by switching opening/closing of the drain switching valves (34, 35) is learned to improve a control characteristic in the vicinity of the rapidly changing point of the VCT response speed.

Claims30

Dependent claims

1-29. (canceled)

A controller for a vane-type variable valve timing adjusting mechanism in which each of a plurality of vane accommodating chambers formed in a housing is divided into an advance hydraulic chamber and a retard hydraulic chamber by a vane, a one-way valve is disposed in each of a hydraulic supply passage of the advance hydraulic chamber and a hydraulic supply passage of the retard hydraulic chamber in at least one of the vane accommodating chambers for preventing reverse flow of operating oil from the each hydraulic chamber, a drain oil passage is disposed in parallel to the hydraulic supply passage of the each hydraulic chamber for bypassing the one-way valve and a hydraulic control valve for controlling a hydraulic pressure supplied to the each hydraulic chamber includes integrally a drain switching control function for opening/closing the drain oil passage of the each hydraulic chamber, wherein:

response characteristic learning means is provided for learning a response characteristic of the variable valve timing adjusting mechanism to a control current value of the hydraulic control valve.

a first one-way valve disposed in a hydraulic supply passage of the advance hydraulic chamber in at least one of the vane accommodating chambers for preventing reverse flow of operating oil from the advance hydraulic chamber;
a first drain oil passage bypassing the first one-way valve;
a second one-way valve disposed in a hydraulic supply passage of the retard hydraulic chamber in at least one of the vane accommodating chambers for preventing reverse flow of operating oil from the retard hydraulic chamber;
a second drain oil passage bypassing the second one-way valve;
and
a hydraulic control valve for controlling the hydraulic pressure supplied to the variable valve timing adjusting mechanism, wherein:
the hydraulic control valve includes integrally a drain switching control function for opening/closing the first and second drain oil passages, further comprising:
response characteristic learning means for learning a response characteristic of the variable valve timing adjusting mechanism to a control current value of the hydraulic control valve.

5 more elements

a first one-way valve disposed in a hydraulic supply passage of the advance hydraulic chamber in at least one of the vane accommodating chambers for preventing reverse flow of operating oil from the advance hydraulic chamber;
a first drain control valve disposed in a first drain oil passage bypassing the first one-way valve and driven by a hydraulic pressure;
a second one-way valve disposed in a hydraulic supply passage of the retard hydraulic chamber in at least one of the vane accommodating chambers for preventing reverse flow of operating oil from the retard hydraulic chamber
a second drain control valve disposed in a second drain oil passage bypassing the second one-way valve and driven by the hydraulic pressure;
a first hydraulic control valve for controlling the hydraulic pressure supplied to the variable valve timing adjusting mechanism;
and
a second hydraulic control valve for controlling the hydraulic pressure driving the first and second drain control valves, wherein:
a shaft of the first hydraulic control valve is integral with a shaft of the second hydraulic control valve, further comprising:
response characteristic learning means for learning a response characteristic of the variable valve timing adjusting mechanism to a control current value for controlling the hydraulic control valve and the drain control valve.

6 more elements

Dependencies are inferred from the claim text.

Controller for vane-type variable timing adjusting mechanism

Life of this patent

Controller for vane-type variable timing adjusting mechanism

Life of this patent

Abstract

Claims30