Fuel Injector and Control Method for Internal Combustion Engine

• US 20130104856A1
• Filed: 05/26/2011
• Published: 05/02/2013
• Est. Priority Date: 05/27/2010
• Status: Active Grant

• Current Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Sakamoto, Hideyuki, Fukuda, Takao
• Granted Patent: US 9,777,667 B2
• Time in Patent Office: Days
• US Class Current: 123/490
• CPC Class Codes: F02D 2041/2006 by using a boost capacitor
• CPC Class Codes: F02D 2041/201 by using a boost inductance
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils
• CPC Class Codes: F02D 41/32 of the low pressure type F02D41/3082 takes precedence
• CPC Class Codes: F02D 41/38 of the high pressure type

Abstract

A fuel injection control system for an internal combustion engine includes a plurality of first energy storage elements each for supplying a high voltage to a fuel injection solenoid valve, boosting circuits each for boosting a battery voltage and electrically charging one of the first energy storage elements, a second energy storage element for accumulating electrical energy of the battery voltage, and a switching circuit for transferring the electrical energy between the plurality of first energy storage elements via the second energy storage element. This configuration enables the fuel injection control system for an internal combustion engine to implement stabilized supply of a fuel by obtaining within a short time the high voltage needed to operate the fuel injector both accurately and reliably, and to contribute to cost reduction by, for example, alleviating capability requirements and part performance requirements of the individual boosting circuits.

Claims

1. A control system used for a fuel injection device equipped with a fuel injection solenoid valve for supplying a fuel directly to a combustion chamber interior of an internal combustion engine, the system comprising:

a plurality of first energy storage elements, each for supplying a high voltage to the fuel injection solenoid valve;

a boosting circuit for boosting a battery voltage and electrically charging each of the first energy storage elements;

a second energy storage element for accumulating electrical energy of the battery voltage; and

a switching circuit for transferring the electrical energy between the plurality of first energy storage elements via the second energy storage element.

2. The fuel injection control system according to claim 1, wherein

the system transfers the electrical energy between the plurality of first energy storage elements by operating the switching circuit and changing a connection potential across the second energy storage element as appropriate.

3. The fuel injection control system according to claim 1, further comprising

means for monitoring a voltage of the plurality of first energy storage elements;

wherein the system controls the transfer of the electrical energy so that the voltage of one of the first energy storage elements that is to be used for next fuel injection is an appropriate voltage.

4. The fuel injection control system according to claim 3, further comprising

a resistive element connected in series to the second energy storage element;

wherein the system controls an amount of the electrical energy transfer between the plurality of first energy storage elements by controlling an operation time of the switching circuit.

5. The fuel injection control system according to claim 4, wherein:

prior to boosting, the monitoring means monitors the voltage of that energy storage element of the first energy storage elements that is involved with the boosting process; and

upon a target voltage level being reached, the system changes an operational state of the switching circuit.

6. The fuel injection control system according to claim 4, wherein:

the resistive element is connected in series to the second energy storage element, only when a charge is released from the second energy storage element.

7. The fuel injection control system according to claim 1, wherein

the boosting circuit is present in plurality.

8. The fuel injection control system according to claim 2, wherein

one end of the second energy storage element is connected, via the switching circuit, to a downstream side of the switching circuit for supplying the high voltage from one of the first energy storage elements to the fuel injection solenoid valve.