Fuel injection control device

Patent metadata

Field	Value
Publication number	US-9790905-B2
Application number	US-201514678181-A
Country	US
Kind code	B2
Filing date	Apr 3, 2015
Priority date	Apr 7, 2014
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A fuel injection control device which is provided with an input terminal to which a first pulse signal for driving a liquid fuel injection valve is input and an output terminal from which the first pulse signal is output, and converts the first pulse signal which is input from the input terminal to a second pulse signal for driving a gaseous fuel injection valve, includes: a P-channel field-effect transistor interposed in a wiring which connects the input terminal and the output terminal; a switching control section which performs switching control between an ON state and an OFF state of the field-effect transistor; and a gate drive circuit which maintains the field-effect transistor in the ON state in a case where power supply to the switching control section is not performed.

First claim

What is claimed is:

1. A fuel injection control device which is provided with an input terminal to which a first pulse signal for driving a liquid fuel injection valve is input and an output terminal from which the first pulse signal is output, and converts the first pulse signal which is input from the input terminal to a second pulse signal for driving a gaseous fuel injection valve, the device comprising:
a P-channel field-effect transistor interposed in a wiring which connects the input terminal and the output terminal;
an electronic controller configured to switch between an operation of outputting the first pulse signal from the output terminal and an operation of converting the first pulse signal to the second pulse signal by performing switching control between an ON state and an OFF state of the field-effect transistor;
a gate drive circuit which maintains the field-effect transistor in the ON state in a case where an operation of the electronic controller is stopped, and
a protection circuit which is connected between a source and a drain of the field-effect transistor and protects the field-effect transistor when a state of the field-effect transistor is switched,
where the protection circuit is a Zener diode having an anode which is connected to the drain of the field-effect transistor, and a cathode which is connected to the source of the field-effect transistor.

2. The fuel injection control device according to claim 1 , wherein the gate drive circuit includes a capacitor which is interposed between a gate and a source of the field-effect transistor and maintains a voltage between the gate and the source of the field-effect transistor at a voltage at which the field-effect transistor enters the ON state, and
a diode connected to the gate of the field-effect transistor so as to be reverse-biased by the voltage which is maintained by the capacitor, in a case where an operation of the electronic controller is stopped.

3. The fuel injection control device according to claim 2 , further comprising: a driver circuit which short-circuits the gate and the source of the field-effect transistor in a case where the electronic controller controls the field-effect transistor such that it enters the OFF state.

4. The fuel injection control device according to claim 2 , further comprising: a protection circuit which is connected between a source and a drain of the field-effect transistor and protects the field-effect transistor when a state of the field-effect transistor is switched.

5. The fuel injection control device according to claim 3 , further comprising: a protection circuit which is connected between a source and a drain of the field-effect transistor and protects the field-effect transistor when a state of the field-effect transistor is switched.

Assignees

• Keihin Corp

Inventors

• Katagata Masahiro
• Sugimoto Yusuke

Classifications

• F02M21/0254

  Electric actuators, e.g. solenoid or piezoelectric · CPC title

• F02D19/024

  by controlling fuel injectors · CPC title

• F02D2041/2013

  by using a boost voltage source · CPC title

• F02D2041/2075

  Type of transistors or particular use thereof · CPC title

• F02M51/005 Primary

  Arrangement of electrical wires and connections, e.g. wire harness, sockets, plugs; Arrangement of electronic control circuits in or on fuel injection apparatus · CPC title