Internal combustion engine ignition device

Patent metadata

Field	Value
Publication number	US-9587616-B2
Application number	US-201213712623-A
Country	US
Kind code	B2
Filing date	Dec 12, 2012
Priority date	Dec 15, 2011
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

An internal combustion engine ignition device can determine ignition timing with high precision to perform ignition with high precision even where noise superimposed at the time of rise of current flowing through an ignition coil is generated. In an internal combustion engine ignition device including an output terminal for detecting an internal state such as a coil current, it is possible to prevent generation of pulse noise in the form of chattering at falling and rising edges of a voltage of the output terminal by using a hysteresis comparator, even if noise is superimposed at the time of rise of the coil current. Therefore, a voltage pulse with pulse width of high precision is transmitted to an electronic control unit without the influence of noise, and the ignition timing can be determined properly with high precision.

First claim

What is claimed is:

1. An internal combustion engine ignition device, in which an on-off control of current for energizing an ignition coil is performed by a switching element upon receiving a control signal, and an output terminal for externally outputting an ignition state of the ignition coil is provided, the internal combustion engine ignition device comprising:
voltage converting means for converting the current to a voltage, the converted voltage being referred to as a sense voltage;
first comparing means for comparing the sense voltage with each of two reference voltages, the two reference voltages being a first detection reference voltage for detecting the sense voltage at a time of rise and a first release reference voltage which is a voltage lower than the first detection reference voltage, to output a first output signal, the first comparing means having a hysteresis characteristic;
second comparing means for comparing the sense voltage with each of two other reference voltages, the two other reference voltages being a second detection reference voltage for detecting the sense voltage at a time of rise and a second release reference voltage which is a voltage lower than the second detection reference voltage and higher than the first detection reference voltage, to output a second output signal, the second comparing means having a hysteresis characteristic;
output means for receiving the first output signal output from the first comparing means and the second output signal output from the second comparing means and for outputting a third output signal; and
switch means for controlling the output terminal to be on or off using the third output signal output from the output means;
wherein the first comparing means is formed of an inverting input switching-type comparator.

2. The internal combustion engine ignition device according to claim 1 , wherein the second comparing means is formed of a second hysteresis comparator,
the second hysteresis comparator including a second comparator, a third inverter to which an output of the second comparator is input, a fourth inverter to which an output of the third inverter is input, a third analog switch which connects the second detection reference voltage to a minus terminal of the second comparator, and a fourth analog switch which connects the second release reference voltage to the minus terminal of the second comparator, and the second hysteresis comparator being configured such that the sense voltage is input to a plus terminal of the second comparator, an on-off operation of the third analog switch is caused by an output signal of the third inverter, an on-off operation of the fourth analog switch is caused by an output signal of the fourth inverter, the on-off operation of the third analog switch and the on-off operation of the fourth analog switch are in a reversed phase relationship, and the third analog switch is in an on state when the sense voltage is lower than the second release reference voltage.

3. The internal combustion engine ignition device according to claim 2 , wherein
the first comparing means includes two minus inputs that are switched and used for comparison, and an inverting input switching control circuit which transmits a switching signal to the inverting input switching-type comparator, receives an output signal of the second hysteresis comparator and an output signal of the inverting input switching-type comparator, and receives a signal that is in synchronization with a control signal for turning on or off the switching element for controlling the current of the ignition coil,
a detection reference voltage of the inverting input switching-type comparator is the first detection reference voltage, and
a release reference voltage of the inverting input switching-type comparator is at ground potential.

4. The internal combustion engine ignition device according to claim 3 , wherein the inverting input switching-type comparator includes a third comparator, a fifth inverter to which an output signal of the third comparator is input, a sixth inverter to which an output signal of the fifth inverter is input, a fifth analog switch which connects the first detection reference voltage to a minus terminal of the third comparator, and a sixth analog switch which connects the first release reference voltage to the minus terminal of the third comparator,
the sense voltage is input to a plus terminal of the third comparator, an on-off operation of the fifth analog switch is caused by an output signal of the inverting input switching control circuit, an on-off operation of the sixth analog switch is caused by a signal which is obtained by inverting an output signal of the inverting input switching control circuit by a seventh inverter, the on-off operation of the fifth analog switch and the on-off operation of the sixth analog switch are in a reversed phase relationship, and
the fifth analog switch is in an on state when the sense voltage is at the ground potential.

5. The internal combustion engine ignition device according to claim 4 , wherein the inverting input switching control circuit is a logic circuit formed of an inverter circuit, an AND circuit, and an OR circuit.

6. The internal combustion engine ignition device according to claim 3 , wherein the inverting input switching control circuit is a logic circuit formed of an inverter circuit, an AND circuit, and an OR circuit.

7. The internal combustion engine ignition device according to claim 2 , wherein the first comparing means includes two minus inputs that are switched and used for comparison, and an inverting input switching control circuit which transmits a switching signal to the inverting input switching-type comparator, receives an output signal of the second hysteresis comparator and an output signal of the inverting input switching-type comparator, and receives a signal that is in synchronization with a control signal for turning on or off the switching element for controlling the current of the ignition coil,
a detection reference voltage of the inverting input switching-type comparator forming the first comparing means and the second release reference voltage of the second hysteresis comparator are the same, and
the release reference voltage of the inverting input switching-type comparator is at ground potential.

8. The internal combustion engine ignition device according to claim 2 , wherein the voltage converting means is a resistor, the output means is an exclusive OR circuit which outputs a result of exclusive OR of the first output signal output from the first comparing means and the second output signal output from the second comparing means, and the switch means is a MOSFET.

9. The internal combustion engine ignition device according to claim 1 , wherein the voltage converting means is a resistor, the output means is an exclusive OR circuit which outputs a result of exclusive OR of the first output signal output from the first comparing means and the second output signal output from the second comparing means, and the switch means is a MOSFET.

10. The internal combustion engine ignition device according to claim 7 , wherein the inverting input switching-type comparator includes a third comparator, a fifth inverter to which an output signal of the third comparator is input, a sixth inverter to which an output signal of the fifth inverter is input, a fifth analog switch which connects the first detection reference voltage to a minus terminal of the third comparator, and a sixth analog switch which connects the first release reference voltage to the minus terminal of the third comparator,
the sense voltage is input to a plus terminal of the third comparator, an on-off operation

Assignees

• Fuji Electric Co Ltd

Inventors

• Minoya Yoshiaki
• Kohama Takanori

Classifications

• F02P17/12

  Testing characteristics of the spark, ignition voltage or current (testing of sparking plugs H01T13/60) · CPC title

• F02P5/15 Primary

  Digital data processing · CPC title

• F02P3/0414

  using digital techniques (F02P3/0428, F02P3/0442 take precedence) · CPC title

• G05F3/02 Primary

  Regulating voltage or current · CPC title