| 摘要 |
PROBLEM TO BE SOLVED: To suppress charging voltage of a capacitor increasing when an open failure occurs in a switch for discharge from the capacitor to a coil, in a solenoid valve drive device.SOLUTION: In a solenoid valve drive device, during an electric conduction period in which an injection command signal S#n becomes high, a transistor T10 provided on a downstream side of a coil of an injector is turned on, and at start time of the electric conduction period, a transistor for discharge provided between a capacitor and an upstream side of the coil is turned on, and a peak current is flowed from the capacitor to the coil, and after that, till the end time of the electric conduction period, the transistor T11 provided between a battery voltage and the upstream side of the coil is controlled by being turned on/off to flow a constant current to the coil. When an open failure of the transistor for discharge is detected, off-timing of the transistor T10 is delayed by delay time Td from the end time of the electric conduction period, and flyback energy (regenerative current) recovered to the capacitor from the downstream side of the coil is reduced. |
