Injection control device
AssigneeDenso Corporation
InventorsHIROAKI SHIRAKAWA, MASASHI INABA
Life of this patent
Estimating the term…
Abstract
An injection control device includes a boost controller performing boost control of a boosted voltage until a boosted voltage, which is generated in a boost capacitor, rises to a full-charge threshold when the boosted voltage falls below a charge start threshold. A drive unit supplies electric current to a fuel injection valve from a start timing t1 of an injection instruction period. A power interruption controller interrupts electric current supplied to the fuel injection valve by the drive unit. A regeneration unit regenerates electric current generated in the fuel injection valve which is caused by interruption control by the power interruption controller to the boost capacitor of the booster circuit.
Claims16
An injection control device for controlling injection by supplying electric current to a fuel injection valve, the boost control device comprising:
- a booster circuit boosting a battery voltage to generate a boosted voltage in a boost capacitor;
- a boost controller performing boost control by the booster circuit, including starting boost control when the boosted voltage falls below a charge-start threshold, and ending boost control when the boosted voltage rises to a full-charge threshold;
- a drive circuit supplying an energization current to a fuel injection valve with the boosted voltage or with the battery voltage after a start timing of an injection instruction period;
- a power interruption controller interrupting the energization current supplied by the drive circuit to the fuel injection valve;
- and
- a regeneration unit passing a regenerative current from the fuel injection valve to the boost capacitor of the booster circuit, wherein the regenerative current is caused by an interruption control of the power interruption controller,
- wherein the boost controller stops the boost control by the booster circuit during a boost prohibition period,
- wherein the boost prohibition period at least partly includes passing the regenerative current caused by the interruption control,
- wherein the boost prohibition period begins a fixed period of time after a start time of an injection period, and
- wherein the interruption control begins after the boost prohibition period begins.
An injection control device comprising:
- a control circuit;
- a booster circuit configured to generate a boost voltage, and including:
- a boost inductor, a boost switch, a boost resister, a boost diode, and a boost capacitor;
- a regenerative circuit configured to pass a regenerative current towards the booster circuit;
- a discharge switch located electrically between the booster circuit and a fuel injection valve;
- a constant current switch located electrically between a battery voltage and the fuel injection valve;
- a high side terminal configured for connection to a fuel injection valve;
- a low side terminal configured for connection to a low side of the fuel injection valve, and associated with a low-side voltage;
- a low-side drive switch;
- and
- a current detection resistor configured to receive current from the low-side drive switch,
- wherein the control circuit is configured to:
- (i) start charging the boost capacitor by controlling the boost switch when the boost voltage is equal to or smaller than a charge-start threshold;
- and
- (ii) stop charging the boost capacitor by controlling the boost switch when the boost voltage is equal to or greater than a full-charge threshold;
- (iii) prohibit the booster circuit from charging the boost capacitor using the boost switch during a boost prohibition period;
- and
- (iv) charge the boost capacitor using the regenerative current at least during at least part of the boost prohibition period;
- and
- (v) prohibition period is started before a power interruption controller interrupting electric current supplied by the drive circuit to the fuel injection valve.
Dependencies are inferred from the claim text.