JP2002257021A - Ignition device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition device for an internal combustion engine for reducing the circuit scale by reducing the number of part items with a simple structure and preventing the occurrence of erroneous operation. SOLUTION: The energy accumulated in a capacitor 12 at the time of ignition and the energy accumulated in an energy accumulation coil 11 are supplied to the primary coil 14, and after high voltage for ignition is applied to the secondary coil 15, transistors Q1 and Q11 are alternately connected/disconnected to be multiply discharged. At the time, the period for the transistors Q1 and Q11 to be alternately connected/disconnected by a drive circuit 22 is set to determine the multiple discharge period and a discharge section signal IGw with engine cylinder discrimination data is generated. Therefore, there is no need of mounting a flip-flop circuit for storing the cylinder discrimination data, so that the circuit structure of the ignition device is simplified and the circuit scale can be reduced by reducing the number of part items. Moreover, by disusing the flip-flop circuit, the occurrence of malfunction caused by noise, etc., can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine (hereinafter, an "internal combustion engine" is referred to as an engine).

[0002]

2. Description of the Related Art Hitherto, there has been known a multiple discharge type engine ignition device in which a capacity discharge type ignition device and an induction discharge type ignition device are combined to perform a multiple discharge at an ignition discharge timing. An example of this type of ignition device is disclosed in
In the ignition device disclosed in JP-A-15659, at the ignition timing, the energy stored in the energy storage coil and the energy charged in the capacitor for capacitive discharge are supplied to the ignition coil, and the spark plug generates a spark. .
Further, energy is periodically supplied to the ignition plug by the energy storage coil in a predetermined discharge section from the timing at which ignition is started, so that multiple discharges are performed and the spark is maintained. In such a multiple discharge type engine ignition device,
Discharge interruption is less likely to occur than a single discharge type ignition device.

[0003]

In the above-mentioned prior art, the energy stored in the capacitive discharging capacitor and the energy stored in the energy storage coil at the ignition timing are supplied to the primary coil of the ignition coil. After the high voltage for ignition is applied to the secondary coil, the first and second switching elements are alternately turned on and off during a predetermined discharge period.
The continuous multiple discharge is realized by changing the current on the next coil side to plus / minus.

At this time, a predetermined angle of ignition timing (for example, 3
0 ° CA), rises to a high level before, determines the energization period of the energy storage coil during the high level period of the ignition signal that falls at the ignition timing, rises at the ignition timing, and then at a predetermined angle (for example, 30 ° CA). The period of the multiple discharge is determined by the high level period of the falling discharge section signal.

However, in this method, it is necessary to control each cylinder of the engine, and by inputting a plurality of ignition signals for each cylinder, the energization period information of the energy storage coil and the cylinder discrimination information are obtained. For this reason, the ignition signal is at low level during the energization control (multiplex control) of the ignition coil, and it is necessary to provide a flip-flop circuit to store the cylinder discrimination information. Therefore, there is a problem that the circuit configuration of the ignition device becomes complicated and the circuit scale becomes large. In addition, there is a risk that the flip-flop circuit is reset due to noise or the like, causing a malfunction or the like.

The present invention has been made to solve such a problem, and has a simple structure with a reduced number of parts.
An object of the present invention is to provide an ignition device for an engine that reduces the circuit scale. Another object of the present invention is to provide an ignition device for an engine that prevents occurrence of a malfunction.

[0007]

According to the ignition device for an engine of the present invention, the first switching element is turned on / off and the capacitor for discharging the capacitance is charged by the energy stored in the energy storage coil. At the same time, the second switching element is turned on / off at the ignition timing.
The energy that has been cut off and charged in the capacitor for capacitive discharge is supplied to the primary coil of the ignition coil. For this reason, the energy stored in the capacitor for capacitive discharge after the end of the previous ignition and the energy stored in the energy storage coil are supplied to the primary coil of the ignition coil,
A high voltage for ignition is applied to the secondary coil, and the spark plug generates a spark.

Further, the first and second switching elements are alternately intermittently turned on and off in a predetermined discharge period to perform multiple discharges, so that ignition energy is supplied periodically during the discharge period and the spark of the spark plug is maintained. I do. Further, the discharge section setting means is provided with a first switching element control means.
In addition to setting the period in which the second switching element is alternately turned on and off, the cylinder discrimination information of the engine is sent to the switching element control means. Can be provided with cylinder discrimination information, or a cylinder discrimination signal can be generated separately from an ignition signal and a discharge section signal. For this reason, switching element control can be directly performed using the discharge section signal including the cylinder discrimination information, and there is no need to separately provide a flip-flop circuit for storing the cylinder discrimination information. The configuration becomes simple,
The circuit scale can be reduced by reducing the number of parts.
Further, by eliminating the flip-flop circuit, occurrence of malfunction due to noise or the like can be prevented.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an electrical configuration of an engine ignition device according to a first embodiment of the present invention.
The ignition device of the first embodiment is mounted on a vehicle and is a DLI (Distributor Less Ignition) type ignition device.

In FIG. 1, an energy storage coil 11 and a transistor Q1 are connected in series between a plus terminal of a battery 10 and a ground. Battery 10 is 1
It is a 2-volt specification. Energy is stored in the energy storage coil 11 by energization when the transistor Q1 is turned on. At this time, the current flowing through the energy storage coil 11 and i _0. The point a between the energy storage coil 11 and the transistor Q1 is connected via a diode D1 to a capacitor 12 as a capacitor for discharging capacity.
The capacitor 12 is charged by the energy stored in the energy storage coil 11.

A first cylinder ignition coil 1 is connected between the point b between the diode D1 and the capacitor 12 and the ground.
3, a primary coil 14, a transistor Q11, and a current detection resistor 16 are connected in series. Then, the energy charged in the capacitor 12 by turning on / off the transistor Q11 can be supplied to the primary coil 14 of the ignition coil 13. At this time, the current (primary current) flowing through the primary coil 14 is defined as i ₁ . Ignition coil 13-2
A first cylinder ignition plug (not shown) is connected to the next coil 15. A current (secondary current) i ₂ flows through the secondary coil 15 with the energization of the primary coil 14.

Similarly, the primary coil 18, the transistor Q12, and the current detecting resistor 20 of the ignition coil 17 for the second cylinder are connected in series between the point b and the ground. A secondary cylinder spark plug (not shown) is connected to the secondary coil 19 of the ignition coil 17.

In FIG. 1, the ignition coil 17 for the second cylinder, the transistor Q12, and the current detecting resistor 20 are used.
However, ignition coils, transistors, and resistors for the number of engine cylinders are provided. Further, a reflux diode Dfh is connected in parallel to the above-mentioned capacitor 12, and the current flowing through the primary coil 14 (18) when the transistor Q11 (Q12) is off is returned via the diode Dfh.

On the other hand, an electronic control unit (ECU;
The onic control unit 21 can receive signals from various sensors and detect the state of the engine (intake air amount, rotation speed, cooling water temperature, etc.). And ECU
21 determines an optimal ignition timing according to the engine state at that time. A drive circuit 22 is connected to the ECU 21, and the ECU 21 serving as a discharge section setting unit outputs an ignition signal IGt and a discharge section signal IGw to the drive circuit 22. This discharge section signal IGw is a signal for each cylinder,
The discharge section signals IGw # 1 to IGw # n for each cylinder have cylinder discrimination information. The drive circuit 22 as a switching element control means includes the transistors Q1 and Q11 described above.
And Q12 are connected to output a drive signal A to the transistor Q1, output a first cylinder drive signal B # 1 to the transistor Q11, and output a second cylinder drive signal B # 2 to the transistor Q12.

The ECU 21 also includes a resistor 16 for detecting the current.
And the applied voltage between both terminals (voltage at the α1 point) is monitored. Similarly, the ECU 21 monitors the applied voltage (the voltage at the point α2) between the two terminals of the current detection resistor 20 corresponding to the cylinders other than the first cylinder. The voltage applied between both terminals of the current detection resistors 16 and 20 is the primary current i
_{According to 1} .

As described above, the battery 1 as a DC power supply
0, an energy storage coil 11, and a transistor Q1 as a first switching element, a first series circuit is formed, and a capacitor 1 is connected to the energy storage coil 11 via a diode D1 as backflow prevention means.
2 is further connected, and a second series circuit including the capacitor 12, the primary coil 14 (18) of the ignition coil 13 (17), and the transistor Q11 (Q12) as a second switching element is formed. ing. ECU2
As described later, 1 sets a period in which the transistors Q1 and Q11 (Q12) are turned on / off by the drive circuit 22, determines a period of the multiple discharge, and gives the engine cylinder discrimination information to the discharge section signal IGw. Ignition signal IGt
At the same time, a discharge section signal IGw is sent to the drive circuit 22.

Next, the operation of the ignition device configured as described above will be described with reference to FIGS. Discharge section signal IGw # 1, ignition signal IGt, transistor Q
1 and the driving signal B # of the transistor Q11.
FIG. 2 shows signal waveforms and current waveforms of a current i ₀ , a current i ₀ flowing through the energy storage coil 11, a primary current i ₁ of the ignition coil 13, and a secondary current i ₂ . FIG. 3 shows signal waveforms and current waveforms for each cylinder of the engine.

An ignition signal IGt is output from the ECU 21 to the drive circuit 22. The ignition signal IGt corresponds to t1 to t2 in FIG.
During the period of H. The drive circuit 22 outputs a drive signal A having a waveform synchronized with the signal IGt to the transistor Q
Output to 1. The signal A turns on the transistor Q1 to gradually increase the current i ₀ , and the high voltage energy generated in the energy storage coil 11 when the transistor Q1 is turned off is supplied to the ignition coil 1 via the diode D1.
3 is supplied to the primary coil 14.

On the other hand, the discharge section signal IGw # 1 is at t
It is at the H level during the period of 2 to t3, and discharge is performed during this period. Specifically, the drive circuit 22 outputs a signal (a signal inverted at the timing of t11, t12,...) Inverted every predetermined time as the drive signal A to the transistor Q1, and outputs the high-voltage energy generated in the energy storage coil 11 when the transistor is turned off. Is stored in the capacitor 12 via the diode D1 (so-called multiple charging). During this repetitive operation, the drive circuit 22 outputs a signal (t2, t11, t12,...) Complementary to the drive signal A as the drive signal B # 1.
Is output to the transistor Q11). By the signal B # 1, the energy of the capacitor 12 is supplied to the primary coil 14 of the ignition coil 13,
During disconnection of the primary current i ₁ (t11 in FIG. 2, t13, t1
5, a large secondary current i ₂ (high voltage) is generated at time t17, and multiple ignition is performed.

Then, for the next ignition, the transistor Q1 is turned on at the timing of t17,
The state is turned off at the timing of 18, and t17 to t1
The energy generated in the energy storage coil 11 during the period 8 is stored in the capacitor 12. That is, when the transistor Q11 is turned on during the period from t2 to t11 in the operation for the current ignition, the energy accumulated in the capacitor 12 during the period from t17 to t18 (the operation for the previous ignition) and the period between t1 and t2 And the energy generated in the energy storage coil 11 is supplied to the primary coil 14 of the ignition coil 13. That is, in the primary current i ₁ in the period t2~t11 in Figure 2, the projecting current portion e1 of charge is energy stored in the capacitor 12, then the energy gentle current portion e2 during the t1~t2 storage coil 11 Energy generated by

As shown in FIG. 3, the same operation is performed in other cylinders than the first cylinder. That is, in the drive circuit 22, the cylinder is determined by the discharge section signal IGw # 2 having the cylinder determination information, and the drive signal B # 2 and the like are output to the transistor Q12 and the like instead of the transistor Q11, and the multiple charge Multiple ignitions are performed.

As described above, the drive circuit 22 as the first switching element control means sets the transistor Q1 to the on / off (conducting / cutoff) state so that the energy storage coil 1
The capacitor 12 is charged by the energy stored in the transistor 1 (Q11) at the ignition timing.
, Etc.) to an on / off state, and the energy charged in the capacitor 12 is transferred to the primary coil (14) of the ignition coil (13).
Etc.), whereby the ignition operation is performed. Specifically, the drive circuit 22 receives the ignition signal IGt and the discharge interval signals IGw # 1 to IGw # n, and continuously turns on / off the transistor Q1 in a predetermined discharge interval for the target cylinder to set the capacitor 12 And the transistor (Q11 etc.) is operated complementarily to the transistor Q1 to perform multiple ignition.

Next, by inputting a plurality of ignition signals IGt for each cylinder, a signal waveform and a signal waveform for each cylinder of the engine of the ignition device according to the comparative example in which the energization period information of the energy storage coil 11 and the cylinder discrimination information are obtained. Figure 7 shows the current waveform
Shown in In the comparative example, as shown in FIG. 7, the ignition signals IGt # 1 to IGt # n attain the L level during the multiple control of the ignition coil, so that a flip-flop circuit is provided, and the current ignition signal IGt attains the H level. From the timing to the timing when the next ignition signal IGt becomes H level.
It is necessary to store the cylinder discrimination information (the signal F / F in FIG. 7) holding the level. For this reason, there is a problem that the circuit configuration of the ignition device becomes complicated and the circuit scale becomes large. Further, the flip-flop circuit is reset by noise or the like, which may cause a malfunction or the like.

On the other hand, in the first embodiment, as shown in FIG. 3, the discharge interval signals IGw # 1 to IGw # n for each cylinder are provided.
Has the cylinder discrimination information, the flip-flop circuit for storing the cylinder discrimination information can be eliminated. In the first embodiment described above, the energy stored in the capacitor 12 and the energy stored in the energy storage coil 11 at the previous ignition timing are applied to the primary coil (14 and the like) of the ignition coil (13 and the like). While being supplied, a high voltage for ignition is applied to the secondary coil (15 or the like), and the spark plug generates a spark.

Further, the transistors (Q1 and Q11, etc.) are alternately intermittently turned on and off in a predetermined discharge period to perform multiple discharges, so that ignition energy is supplied periodically during the discharge period and the spark of the spark plug is maintained. . Further, the discharge section setting means includes a transistor Q
1 and Q11 (Q12) are alternately intermittently set to determine the period of the multiple discharges, and the discharge interval signals IGw # 1 to IGw # n having the cylinder identification information of the engine are generated. There is no need to provide a flip-flop circuit for storing the determination information. Therefore,
The circuit configuration of the ignition device is simplified, the number of components can be reduced, and the circuit scale can be reduced. Further, by eliminating the flip-flop circuit, occurrence of malfunction due to noise or the like can be prevented.

In the first embodiment, the discharge interval signal I for each cylinder
Although the cylinder discrimination information is given to Gw # 1 to IGw # n, in the present invention, the discharge section signal IGw is set to one system, and the cylinder discrimination signal is generated separately from the ignition signal IGt and the discharge section signal IGw. Is possible. That is, the ECU
Channels for the number of engine cylinders, and the ignition signal IG
It is possible to send a cylinder discrimination signal for each cylinder to the drive circuit separately from t and the discharge section signal IGw. This allows
The flip-flop circuit for storing the cylinder discrimination information can be omitted.

As the transistors Q1, Q11 and Q12 in the first embodiment of the present invention described above, bipolar transistors and FETs (preferably P-channel MOSFs) are used.
ET) or IGBT may be used, and any switching element may be used.

[Brief description of the drawings]

FIG. 1 is an electrical configuration diagram showing an engine ignition device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a signal waveform and a current waveform of the engine ignition device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a signal waveform and a current waveform for each engine cylinder of the engine ignition device according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a signal waveform and a current waveform for each engine cylinder of an engine ignition device according to a comparative example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Battery (DC power supply) 11 Energy storage coil 12 Capacitor (capacitor for capacity discharge) 13, 17 Ignition coil 14, 18 Primary coil 16, 20, 33, 37 Current detection resistor 21 ECU (discharge section setting means) 22 Drive Circuit (switching element control means) Q1 transistor (first switching element) Q11, Q12 transistor (second switching element) D1 diode (first backflow prevention means) IGt ignition signal IGW discharge interrogation signal

Claims (1)

[Claims] A first series circuit including a DC power supply, an energy storage coil, and a first switching element; a capacitor for capacitive discharge connected to the energy storage coil via a backflow prevention means; coil,
And a second series circuit including a second switching element, and conducting / cutting off the first switching element to charge the capacitor for discharging capacity with the energy stored in the energy storage coil, Second
Switching element control means for conducting / blocking the switching element to supply the energy charged in the capacitor for discharge to the primary coil to the primary coil; and the first and second switching elements by the switching element control means An ignition section for an internal combustion engine, comprising: a discharge section setting section for setting a period of intermittently intermittently and transmitting cylinder discrimination information of the internal combustion engine to the switching element control section.