Control device for variable valve timing mechanism and control method therefor
AssigneeHitachi Astemo, Ltd.
InventorsMakoto Jitsuishi, Nobuhiko Matsuo
Life of this patent
Estimating the term…
Abstract
A control device for an electric variable valve timing mechanism is provided that can reduce the influence of rotation variations of an engine on a VTC detection angle computation. The control device for a variable valve timing mechanism uses a crank sensor signal and a cam sensor signal of the engine to calculate a rotation phase of the VTC mechanism. A pulse interval of the crank sensor signal is used for a calculation of the rotation phase of the VTC mechanism, and a calculation method of the rotation phase of VTC mechanism is changed depending on the pulse interval of the crank sensor signal determined before the cam sensor signal is input.
Claims10
A control device for a variable valve timing mechanism using a crank sensor signal and a cam sensor signal of an engine to calculate a rotation phase of the variable valve timing mechanism and to control the variable valve timing mechanism, the control device comprising:
- a microcomputer that uses a pulse interval of the crank sensor signal for a calculation of the rotation phase of the variable valve timing mechanism, and changes a calculation method of the rotation phase of the variable valve timing mechanism depending on the pulse interval of the crank sensor signal determined before the cam sensor signal is input, wherein
- the microcomputer is configured to perform feedback control of the rotation phase, which computes and outputs an operation amount of electric motor so that an actual relative rotation phase angle approaches the target phase angle, and is configured to perform feedback control in which the microcomputer is further configured to compute an operation amount of electric motor via proportional integral control, based on a deviation between the target phase angle and the actual relative rotation phase angle.
A control method for a variable valve timing mechanism using a crank sensor signal and a cam sensor signal of an engine to calculate a rotation phase of the variable valve timing mechanism and to control the variable valve timing mechanism, the control method comprising the steps of:
- calculating the rotation phase of the variable valve timing mechanism by using a pulse interval of the crank sensor signal;
- changing a calculation method of the rotation phase of the variable valve timing mechanism depending on the pulse interval of the crank sensor signal determined before the cam sensor signal is input;
- performing feedback control of the rotation phase, which computes and outputs an operation amount of electric motor so that an actual relative rotation phase angle approaches the target phase angle;
- and
- performing feedback control in which the microcomputer is further configured to compute an operation amount of electric motor via proportional integral control, based on a deviation between the target phase angle and the actual relative rotation phase angle.
Dependencies are inferred from the claim text.