JP2002266684A - Fuel injection control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection control device for performing a high-speed charging by use of two kinds of high-voltage and low-voltage power sources. SOLUTION: A constant current circuit 10 is a circuit for interrupting the current carried to an injector to control the current carried to the injector to a fixed quantity or less. A booster circuit 20 is a circuit comprising a DC/DC converter and the like to raising and applying the voltage of the high-voltage power source 40 to the injector. A control circuit 30 is a circuit for controlling the constant current circuit 10 and the booster circuit 20. The high-voltage power source 40 is, for example, a 42-V power source, and the low-voltage power source 50 is, for example, a 14-V power source. The high voltage of the power source 40 is applied to the booster circuit 20 and the control circuit 30. The low voltage of the power source 50 is applied to the constant current circuit 10. The capacitor of the booster circuit 20 for accumulating energy can be charged in a short time by applying the high voltage to the booster circuit 20 to quickly apply the high voltage to the injector.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for an internal combustion engine used in a vehicle (hereinafter referred to as an "internal combustion engine").
The present invention relates to a fuel injection control device that controls an injection amount of a “fuel injection device”.

[0002]

2. Description of the Related Art An injector for an engine used in a vehicle such as an automobile is driven and controlled by a booster circuit, a constant current circuit, a control circuit and the like. The booster circuit is a circuit that generates a high voltage to be applied to the electric drive unit of the injector, and includes, for example, a DC / DC converter. The constant current circuit is a circuit that controls the current flowing through the injector to a certain amount or less. The control circuit is a circuit that controls the booster circuit and the constant current circuit.

[0003]

The booster circuit has a capacitor for storing energy for applying a high voltage to the injector. Therefore, when the voltage applied to the booster circuit is higher, the capacitor can be charged at a higher speed, and the amount of control current for performing charge control can be reduced, so that the amount of heat generated by the power element can be reduced. In the constant current circuit, it is desirable that the applied voltage is not a high voltage in order to reduce heat generation and protect the elements. However,
Since the power supply mounted on the conventional vehicle is a single power supply of 14 V, a high voltage cannot be applied to the booster circuit. Therefore, there is a problem that the charging time becomes longer, the amount of control current for performing the charging control increases, and the amount of heat generated by the power element increases.

It is an object of the present invention to provide a high voltage and a low voltage.
An object of the present invention is to provide a fuel injection control device that performs high-speed charging using various types of power supplies. Another object of the present invention is to provide a fuel injection control device that performs high-speed charging and reduces heat generation by using two types of power supplies, a high voltage and a low voltage.

[0005]

According to the fuel injection control device of the first aspect of the present invention, by applying a high voltage of the first power supply to the boosting circuit, high-speed charging is enabled by the boosting circuit and charging is performed. Heat generation of the power element that performs control can be reduced.

According to the fuel injection control device of the second aspect of the present invention, since the high voltage of the first power supply is applied to the booster circuit,
The boosting circuit enables high-speed charging, and reduces heat generation of the power element that performs charge control. Also, since the low voltage of the second power supply is applied to the constant current circuit and the control circuit,
While reducing the heat generation of the constant current circuit and the control circuit,
The amount of circuits for protecting the elements of the constant current circuit and the control circuit can be reduced.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIG. 1 shows a fuel injection control device according to a first embodiment of the present invention. The fuel injection control device controls an injection amount of an engine injector used for a vehicle. The fuel injection control device has a constant current circuit 10, a boost circuit 20, a control circuit 30, a high voltage power supply 40 and a low voltage power supply 50.

[0008] The constant current circuit 10 is a circuit for interrupting the current flowing through an injector (not shown) and controlling the current flowing through the injector to a predetermined amount or less. The booster circuit 20 is DC
The DC / DC converter is a circuit that boosts the voltage of the high-voltage power supply 40 and applies it to an injector (not shown).
The output of either the constant current circuit 10 or the boost circuit 20 is output to the injector. The control circuit 30 is a circuit that controls the constant current circuit 10 and the booster circuit 20. The high-voltage power supply 40 as the first power supply is, for example, a 42V power supply, and the low-voltage power supply 50 as the second power supply is, for example, a 14V power supply. The high voltage of the high voltage power supply 40 is applied to the booster circuit 20 and the control circuit 30. The low voltage of the low voltage power supply 50 is applied to the constant current circuit 10.

The booster circuit 20 has a capacitor for storing energy to apply a high voltage to the injector. Therefore, by applying a high voltage to the booster circuit 20, a capacitor that stores energy can be charged in a short time, and a high voltage can be quickly applied to the injector. Further, the control current for controlling the charging of the energy storage capacitor can be reduced. Further, since a low voltage is applied to the constant current circuit 10, the heat generation of the constant current circuit 10 is reduced, and a Zener diode or a power resistor for preventing the element from being damaged by applying an overvoltage to the constant current circuit 10 is provided. The amount used can be minimized.

(Second Embodiment) FIG. 2 shows a fuel injection control device according to a second embodiment of the present invention. The same reference numerals are given to the same components as those in the first embodiment, and the description will be omitted. The high voltage of the high voltage power supply 40 is applied to the booster circuit 20. The low voltage of the low voltage power supply 50 is applied to the constant current circuit 10 and the control circuit 30. The heat generation of the constant current circuit 10 and the control circuit 30 is reduced, and the use of a zener diode, a power resistor, and the like for preventing the elements from being damaged by applying an overvoltage to the constant current circuit 10 and the control circuit 30 is minimized. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a fuel injection control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a fuel injection control device according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 constant current circuit 20 booster circuit 30 control circuit 40 high voltage power supply (first power supply) 50 low voltage power supply (second power supply)

Claims (2)

[Claims] 1. A fuel injection control device for controlling an injection amount of a fuel injection device for an internal combustion engine used in a vehicle, comprising: a booster circuit for generating a high voltage applied to the fuel injection device; A booster circuit, a control circuit that controls the booster circuit and the constant current circuit, a first power supply, and a second power supply having a lower voltage than the first power supply. A fuel injection control device comprising: applying a voltage of the first power supply to a circuit and the control circuit; and applying a voltage of the second power supply to the constant current circuit. 2. A fuel injection control device for controlling an injection amount of a fuel injection device for an internal combustion engine used for a vehicle, comprising: a booster circuit for generating a high voltage applied to the fuel injection device; A constant current circuit for reducing a current to a certain amount or less; a control circuit for controlling the booster circuit and the constant current circuit; a first power supply; and a second voltage power supply having a lower voltage than the first power supply, A fuel injection control device comprising: applying a voltage of the first power supply to a boost circuit; and applying a voltage of the second power supply to the constant current circuit and the control circuit.