Control device and control method for variable valve mechanism

Abstract

The present invention relates to a control device and a control method for a variable valve mechanism operated by the oil pressure of a variable-capacity pump capable of having the capacity thereof changed. A control device and a control method for a variable valve mechanism are provided which are capable of inhibiting deterioration in fuel consumption and drivability. When a variable valve mechanism operated by the oil pressure of a variable-capacity pump is controlled, the control gain of the variable valve mechanism is changed in accordance with switching conditions or a switching operation for the capacity of the variable-capacity pump. As a result of changing the control characteristics of the variable valve mechanism in accordance with the switching of the variable-capacity pump, the hydraulic variable valve mechanism can be driven in accordance with the actual oil-pressure state, and thus overshooting and response delay can be inhibited, and deterioration in fuel consumption and drivability can be inhibited.

Description

Technical field [0001] The present invention relates to a control device and a control method of a variable valve mechanism that is operated by the hydraulic pressure of a variable displacement pump capable of changing the capacity. Background technique [0002] Conventionally, in an engine equipped with a variable valve mechanism that operates by hydraulic pressure (abbreviated as a hydraulic VTC mechanism), the hydraulic pressure is estimated based on the number of engine revolutions, cooling water temperature, and the like, and a control gain for driving the hydraulic VTC mechanism is set. However, in the case of using a variable displacement pump such as an electronically controlled second-speed hydraulic control pump (also called an electronically controlled VDVP or two-stage hydraulic pump) to supply hydraulic oil, in order to suppress the oscillation of the solenoid, the supply characteristic is always Switching has hysteresis characteristics. Therefore, even in the case ...

AI Technical Summary

Problems solved by technology

However, in the case of supplying hydraulic oil using a variable displacement pump such as an electronically controlled second-stage hydraulically controlled pump (also called an electronically controlled VDVP or a two-stage hydraulic pump), in order to suppress oscillation of the solenoid, the supply characteristic has been made Switching has a hysteresis characteristic

Therefore, even when the engine speed is the same and the cooling water temperature is the same, the hydraulic pressure may be different from the estimate, and the expected responsiveness and controllability of the hydraulic VTC mechanism may not be obtained.

Images