Drive unit of fuel injection device

摘要

In a drive unit of a fuel injection device, an electric current is supplied to the fuel injection device by applying a high voltage to the fuel injection device from a high voltage source whose voltage is boosted to a voltage higher than a battery voltage at the time of opening a valve of the fuel injection device. Thereafter, the electric current supplied to the fuel injection device is lowered to a current value at which a valve element cannot be held in a valve open state by stopping the applying of the high voltage from the high voltage source. Thereafter, in a stage where a supply current is switched to a hold current, another high voltage is applied to the fuel injection device from the high voltage source.

主权项

1. A drive unit of a fuel injection device which has an anchor, a fixed core attracting the anchor by a magnetic attraction force, and a valve element formed separately from the anchor and driven by the anchor, comprising:
a drive circuit configured to apply a voltage larger than a battery voltage to the fuel injection device, thereby causing the valve element to open by the anchor which is attracted to the fixed core, then apply a voltage below 0V to the fuel injection device and reduce a drive current to a first current value at which the valve element cannot be held in a valve open state by the voltage below 0V before the anchor impinges on the fixed core and the valve element reaches a target lift amount, and then apply a voltage to the fuel injection device so that the drive current is increased to a second current value at which the valve element can be held in the valve open state.