JP3880952B2 - Ignition device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ignition device.
[0002]
[Prior art]
For example, in JP-A-9-210359, charge is accumulated by rectifying an oscillation signal of a blocking oscillation circuit and applying it to an ignition capacitor, and when the charging voltage of the ignition capacitor exceeds a predetermined value, An ignition device is disclosed in which a high voltage based on the charging voltage is applied to an ignition plug to cause discharge. Such an igniter is used for igniting a gas turbine engine provided in an aircraft, a rocket, or the like, and is therefore mounted and functioning in an aircraft, a rocket, or the like.
[0003]
[Patent Document 1]
JP-A-9-210359 gazette
[Problems to be solved by the invention]
By the way, the ignition capacitor is charged by the rectified signal of the oscillation signal of the blocking oscillation circuit, and the discharge at the spark plug is a phenomenon of discharging the charge of the ignition capacitor. Therefore, since the ignition capacitor instantaneously changes from the charged state to the discharged state when the spark plug is discharged, the current of the power supply line supplying power to the blocking oscillation circuit is temporarily changed when the spark plug is discharged. Decrease.
[0005]
That is, the power line is loaded with wedge-shaped current noise (wedge-shaped noise) that instantaneously decreases every time the spark plug is discharged (when the ignition capacitor is changed to the discharge state). When the amplitude of the wedge noise increases, other devices receiving power from the power supply line are adversely affected such as malfunction.
[0006]
For example, the MIL standard is known as a US military equipment procurement standard. This MIL standard prescribes in detail the performance that should be satisfied for each field of equipment and equipment used by the US military. Like JIS (Japanese Industrial Standards), the MIL standard attaches a standard number to each field. Is published. Among such MIL standards, the MIL standard of the standard number: MIL-STD-461E defines the amplitude of noise output from the device to the power supply line. Therefore, in order to use the ignition device in the U.S. military, the ignition device is designed so that the amplitude of the wedge-shaped noise output from the ignition device to the power supply line is within the specified value range of MIL-STD-461E. There is a need.
[0007]
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to suppress current fluctuations in a power supply line caused by discharge.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, as a first means, a blocking oscillator, an ignition signal generator for generating a high voltage ignition signal based on an oscillation signal of the blocking oscillator, and the ignition signal generator An ignition device that includes a spark plug that generates a discharge for igniting the engine by applying an ignition signal from the power source, and includes a level fluctuation suppressing unit that suppresses a decrease in current in the power supply line caused by the discharge. Adopt the configuration.
[0009]
Further, as a second means, the level fluctuation suppressing unit adopts a configuration in which when the power supply current in the power supply line decreases beyond a predetermined value due to discharge, a bypass current for correcting the decrease is supplied.
[0010]
Further, as a third means, the level fluctuation suppressing unit outputs a voltage divider that divides the power supply voltage in the power supply line by a resistor, a differentiator that differentiates the divided voltage of the voltage divider, and the differentiator. A configuration is adopted that includes a switching element that opens and closes based on the differential signal, and a resistor that has one end connected to the switching element and the other end connected to a power supply line, and the energization of which is controlled by the switching element.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration of the ignition device according to the present embodiment. This ignition device is connected to a power supply line R and a GND line G as shown in the figure, and operates using DC power supplied via the power supply line R as a power supply. The DC power supply voltage (DC voltage) is, for example, +28 volts.
[0012]
The ignition device includes a power switch S, a blocking oscillator B, an ignition signal generator T, and an ignition plug P. The power switch S is for turning on / off the power supply to the blocking oscillator B. The blocking oscillator B is a characteristic component of the ignition device, and oscillates a pulse signal having a predetermined cycle as an oscillation signal and supplies it to the ignition signal generator T. The details of the blocking oscillator B will be described later.
[0013]
The ignition signal generator T includes an ignition capacitor, rectifies the pulse signal supplied from the blocking oscillator B to generate a rectified signal, and accumulates electric charge by applying the rectified signal to the ignition capacitor. When the terminal voltage of the ignition capacitor exceeds a predetermined value, the charge of the ignition capacitor is supplied to the spark plug P as a high voltage ignition signal. The spark plug P generates a discharge for igniting the engine when receiving an ignition signal from the ignition signal generator T.
[0014]
FIG. 2 is a circuit diagram showing a detailed configuration of the blocking oscillator B. As shown in FIG. As shown in this figure, the blocking oscillator B is configured by cascading a filter unit F, a level fluctuation suppressing unit Y, and a main body unit H. Among these components, the filter unit F and the level fluctuation suppressing unit Y are characteristic components of the blocking oscillator B.
[0015]
The filter unit F is a balanced low-pass filter including capacitors 1 and 4 and coils 2 and 3. The capacitor 1 is provided in a bridge shape between the power supply line R and the GND line G. One end of the coil 2 is connected to the power supply line R, and one end of the coil 3 is connected in series to the GND line G. The capacitor 4 is provided in a bridge shape between the other end of the coil 2 and the other end of the coil 3.
[0016]
The level fluctuation suppressing unit Y is composed of resistors 5, 6, 9 and 12, capacitors 7 and 8, and an NPN transistor 10 (switching element). The resistors 5 and 6 are connected to each other at one end, the other end of the resistor 5 is connected to the other end of the coil 2, and the other end of the resistor 6 is connected to the other end of the coil 3. That is, the resistors 5 and 6 constitute a resistor voltage divider that resistance-divides the power supply voltage, and the voltage at the connection point a is the divided voltage Vs. The capacitor 7 has one end connected to the connection point a and the other end connected to the base terminal of the NPN transistor 10.
[0017]
Each of the capacitor 8 and the resistor 9 has one end connected to the other end of the capacitor 7 and the other end connected to the other end of the coil 3. The resistor 9 and the capacitor 7 constitute a differentiator that differentiates the divided voltage Vs. The NPN transistor 10 has a base terminal connected to the other end of the capacitor 7, one end of the capacitor 7 and the resistor 9, an emitter terminal connected to the other end of the coil 3, and a collector terminal connected to one end of the resistor 12, respectively. Yes. The other end of the resistor 12 is connected to the other end of the coil 2.
[0018]
The main body H includes diodes 13, 16, 17 and 19, resistors 14 and 15, an NPN transistor 18 and a transformer 20. The diode 13 has an anode terminal connected to the other end of the coil 2 and a cathode terminal connected to one end of one primary winding 20 a of the transformer 20. The resistor 14 has one end connected to the cathode terminal of the diode 13 and the other end connected to one end of the other primary winding 20 b and one end of the resistor 15. The other end of the resistor 15 is connected to the anode terminal of the diode 16 and the cathode terminal of the diode 17.
[0019]
The cathode terminal of the diode 16 and the anode terminal of the diode 17 are connected to the other end of the coil 3, respectively. The NPN transistor 18 has a base terminal connected to the other end of the other primary winding 20b, an emitter terminal connected to the other end of the coil 3, and a collector terminal connected to the other end of the one primary winding 20a. . The diode 19 has an anode terminal connected to the other end of the coil 3 and a cathode terminal connected to the base terminal of the NPN transistor 18. The transformer 20 includes the two primary windings 20a and 20b and the secondary winding 20c. One end and the other end of the secondary winding 20c are balanced output terminals of the blocking oscillator B. It has become.
[0020]
Next, the operation of the main part (blocking oscillator B) of the ignition device configured as described above will be described with reference to FIGS. 1, 2, and 3.
[0021]
When the power switch S is turned “ON” and a power supply voltage is applied to the blocking oscillator B, the blocking oscillator B starts an oscillation operation and continuously outputs a pulse signal having a predetermined cycle to the ignition signal generator T. . The ignition signal generator T generates a high voltage ignition signal based on the pulse signal and outputs the ignition signal to the ignition plug P, whereby the ignition plug P generates periodic discharge to ignite the engine.
[0022]
Here, the discharge current in the spark plug P is obtained by discharging the charge accumulated in the ignition capacitor in the ignition signal generator T. Since the ignition capacitor temporarily stops charging of the rectified signal of the pulse signal input from the blocking oscillator B in the charged state, the ignition plug is discharged to the power supply line that supplies power to the blocking oscillator B. That is, every time the ignition capacitor shifts to the discharge state, a wedge-shaped current noise (wedge-shaped noise) whose current value decreases instantaneously is applied.
[0023]
FIG. 3A is a waveform diagram showing the current fluctuation Wa of the power supply line when the level fluctuation suppressing unit Y, which is a characteristic component of the blocking oscillator B, is deleted. The current of the power supply line R (power supply current) has a waveform in which wedge noise that instantaneously decreases in a low voltage direction in synchronization with the discharge cycle is added to the steady current value D. The amplitude of the wedge noise becomes the current fluctuation Wa of the power supply line R. When there is no level fluctuation suppressing part Y, the current fluctuation Wa has a relatively large amplitude.
[0024]
Since this current fluctuation Wa may adversely affect other devices connected to the power supply line R, a standard (for example, MIL-STD-461E) applied to this ignition device has a predetermined value for the current fluctuation Wa. The standard value is set. That is, in order to satisfy the above standard, it is necessary to design the ignition device so that the current fluctuation Wa is within the range of the standard value.
[0025]
The level fluctuation suppression unit Y newly added to the blocking oscillator B operates to cause a bypass current to flow through the power supply line R in synchronization with the generation of the wedge noise, thereby reducing the current value decrease width, that is, the current fluctuation in the wedge noise. Reduce Wa.
[0026]
That is, since the divided voltage Vs is a voltage (power supply voltage) of the power supply line R divided by the resistors 5 and 6, the power supply voltage varies in accordance with the change of the power supply current, and thus similar to the power supply voltage. Change. That is, the divided voltage Vs fluctuates in the wedge noise portion of the power supply current, but takes a constant value in portions other than the wedge noise.
[0027]
Therefore, at the wedge noise part, a signal (differential signal) obtained by differentiating the variation of the divided voltage Vs with a differentiator is input to the base terminal of the NPN transistor 10, and the NPN transistor 10 is turned on by the differential signal As a result, the bypass current flows through the resistor 12. It should be noted that in a portion other than the wedge noise, the differential signal is not input from the differentiator to the base terminal of the NPN transistor 10, so that the NPN transistor 10 is turned off and the bypass current does not flow.
[0028]
As described above, the NPN transistor 10 is turned on in synchronization with the differential signal input to the base terminal (that is, in synchronization with wedge noise), and as a result, a bypass current synchronized with the wedge noise flows through the resistor 12. It will be.
[0029]
Further, the blocking oscillator B in the present embodiment includes a filter unit F in addition to such a level fluctuation suppressing unit Y. As described above, the filter unit F functions as a low-pass filter. Therefore, high-frequency noise, that is, noise having a frequency far higher than the frequency component constituting the wedge noise is output from the blocking oscillator B to the power supply line R. It suppresses that.
[0030]
In addition, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) In the above embodiment, the filter unit F is inserted between the power line R and the level fluctuation suppressing unit Y, but the present invention is not limited to this. It is good also as a structure which replaces the position of the filter part F and the level fluctuation suppression part Y. FIG. (2) Moreover, in the said embodiment, although the differentiator is comprised with the capacitor | condenser 7 and the resistor 9, and the NPN transistor 10 is used as a switching element, this invention is not limited to this.
[0031]
【The invention's effect】
As described above, according to the present invention, since the current fluctuation of the power supply line due to the discharge of the spark plug is suppressed, it is possible to prevent adverse effects on other devices receiving power supply through the power supply line. can do.
Further, for example, it is possible to realize an ignition device that can be used in the US military by suppressing the current fluctuation of the power supply line so as to satisfy the standard value of MIL-STD-461E.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a functional configuration of an ignition device according to an embodiment of the present invention.
FIG. 2 is a circuit diagram showing a detailed configuration of a blocking oscillator B according to an embodiment of the present invention.
FIGS. 3A and 3B are waveform diagrams showing the operation of an embodiment of the present invention, in which FIG. 3A shows an example of current reduction in a power supply line when the level fluctuation suppression unit Y is not provided, and FIG. 3B is a level fluctuation suppression unit; The example of the electric current reduction of the power supply line in the case of having Y is shown.
[Explanation of symbols]
R …… Power supply line S …… Power switch B …… Blocking oscillator T …… Ignition signal generator P …… Ignition plug F …… Filter part Y …… Level fluctuation suppression part H …… Main body parts 1, 4, 7, 8... Capacitors 2 and 3... Coils 5, 6, 9, 12, 14 and 15... Resistors 13, 16, 17 and 19.

Claims (1)

A blocking oscillator, an ignition signal generator that generates a high-voltage ignition signal based on an oscillation signal of the blocking oscillator, and an ignition that generates a discharge for igniting the engine by application of the ignition signal from the ignition signal generator An ignition device including a plug,
A voltage divider that divides the power supply voltage in the power supply line by a resistor, a differentiator that differentiates the divided voltage of the voltage divider, a switching element that opens and closes based on a differential signal output from the differentiator, and one end switching An ignition device comprising: a level fluctuation suppressing unit including a resistor connected to an element and having the other end connected to a power supply line and energization is controlled by a switching element .

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