CN1188850A - Capacitor charging/discharging ignition - Google Patents

Abstract

A condenser charge/discharge ignition system comprises a drive source, a DC-DC converter, an IGN key switch, an ignition capacitor, a thyristor, an ignition coil and a pulser coil. The IGN key switch involves a second switch adapted to be switched off or on in synchronism with the switched-on or off of a first switch. The key-switch operation detector circuit comprising a first and a second voltage detector circuit and a smoothing circuit.

Description

Capacitor charging/discharging ignition

The present invention relates to a capacitor charging/discharging type ignition device in which an engine is started only after an ignition key switch for starting a car, an electric bicycle, etc. is activated by a key.

As a conventional capacitor charging/discharging type ignition device, there are, for example, a device disclosed in JP-A-59-165864 and a device disclosed in JP-U-3-27881. Conventional devices will now be described with reference to FIG. 1 showing the basic circuit configuration of those devices.

In Fig. 1, reference numeral 1 denotes a DC power source (battery); 2 denotes an ignition key switch, which has a switch X that turns on/off a circuit between terminals A and B; 3 denotes a DC-DC converter, the The converter consists of a rectifying diode D1, a smoothing capacitor C1, a transformer T1, a switching transistor Q1, and a switching circuit 4 including a high-frequency switching oscillator. Label 5 represents an ignition coil; 6 represents a pulse generator coil for detecting the ignition moment; D2 and D3 represent rectifier diodes; S1 represents a thyristor for ignition; C2 represents a capacitor for ignition; When the capacitor C2 is overcharged, it is used to detect the overcharged overvoltage detection circuit; and 8 indicates that the trigger operation of the thyristor is controlled by the signal through the pulse generator coil, and is controlled according to the output signal of the overvoltage detection circuit 7 A control circuit for the operation of the switching circuit 4 .

The circuit works in such a way that when the ignition key switch 2 is turned on to close the contact X, the DC power supply 1 is connected to the DC-DC converter 3 through terminals A and B, and the switching circuit 4 is activated through the control circuit 8, allowing The switching transistor Q1 performs a switching operation, and the ignition capacitor C2 is charged through the transformer T1. When the capacitor C2 for ignition reaches a specific voltage by charging, the overvoltage detection circuit 7 operates, whereby the operation of the switching transistor Q1 is stopped by the control circuit 8 . Then when the engine starts to rotate, an ignition signal is input from the pulse generator coil 6 to the control circuit 8, triggering the thyristor for ignition, and releasing the energy in the capacitor C2 for ignition to the ignition coil 5, thereby igniting the engine .

However, according to the conventional ignition device of the capacitor charging/discharging type, the engine can be started by closing the contact X (ON state) by ON operation of the ignition key switch 2 . Therefore, especially in motorcycles among motor vehicles, the amount of wiring around the engine is small, and the wiring is easy to replace, so by using another wire, directly connect the circuit straddling the terminals A and B of the ignition key switch 2 , the same state as the ON state of the contact X of the ignition key switch 2 can be obtained.

The present invention is made to solve the above-mentioned disadvantages, and attempts to provide a capacitor charging/discharging type ignition device in which even if the circuit between the terminals A and B of the ignition key switch is connected by another connecting wire, the engine does not start. In more detail, the present invention provides a capacitor charging/discharging type ignition device which can certainly perform its function even when an AC generator other than a DC power source is used for a starting power source of an engine.

According to the present invention, there is provided an ignition device comprising: a power source including a DC power source and/or a generator; a DC voltage generating circuit for generating a DC voltage according to a control signal when electric power is supplied from the power source; A capacitor for charging or discharging the output voltage of the DC voltage generating circuit; an ignition coil for performing an ignition operation through a discharge current of the capacitor; including a first switch (for turning on/off between the power supply and the DC voltage generating circuit connection) and the ignition key switch of the second switch (for performing on/off operation in an interlocking relationship with the on/off operation of the first switch); the impedance element having the The first and second terminals of the two terminals of the two switches, and the second terminal of the impedance element is connected to the connection point between the first switch and the DC voltage generating circuit; the voltage detection device is used to detect the first of the impedance element. the voltage at the first and second terminals and for generating an output signal based on the measured voltage; and control means for controlling the operation of the DC voltage generating circuit and/or the discharge of the capacitor based on the output signal of the voltage detecting means.

According to the above configuration, the voltage across the terminals of the impedance element (detected by the operation of the ignition key switch at the time of the ON operation of the first switch and the OFF operation of the second switch) is detected, so when the ignition key switch It is not possible to start the engine when it is only a short circuit.

FIG. 1 is a circuit diagram showing an example of a conventional ignition device;

Fig. 2 is a circuit diagram of an ignition device according to an embodiment of the present invention;

3A is a circuit diagram showing a stop state of an ignition key switch included in the ignition device of FIG. 2;

3B is a circuit diagram showing an operating state of an ignition key switch included in the ignition device of FIG. 2;

4 is a diagram showing signal waveforms in each part of the key switch operation detection circuit if an AC generator is used as a power source in the ignition device of the present invention;

5 is a graph showing the operation if the ignition key switch is forcibly short-circuited or released in the ignition device of the present invention;

6A and 6B are circuit diagrams showing other examples of non-linear elements that can be used in the ignition key switch in the ignition device of the present invention.

FIG. 2 shows a circuit diagram according to an embodiment of the present invention, and the same components as those in the circuit diagram of the conventional device shown in FIG. 1 are indicated by the same reference numerals, and their descriptions are omitted. In FIG. 2, reference numeral 11 designates an AC generator having generator coils L1 and L2. The AC generator has a function of supplying electric power to the ignition as a starting power source instead of the DC power source 1 , or charging the DC power source 1 and also lighting the lamp 12 . Reference numeral 13 designates a control device for supplying electric power to each of the above-mentioned applications. Reference numeral 14 designates an ignition key switch. In addition to the switch X between the terminals A and B, a switch Y for performing on/off operation with the switch X is provided between the terminals C and D. A Zener diode Z1 is provided between terminals C and D as an impedance element, preferably a non-linear element. Connect the cathode side of the Zener diode to terminal B on the output side of the ignition key switch 14 . As shown in FIGS. 3A and 3B, the operations of switches X and Y of the ignition key switch 14 are switched by the ignition key (not shown) in an interlocking relationship, so when the ignition key switch 14 is turned off (FIG. 3A), the switch X is off and switch Y is on. When the ignition key switch 14 is on (FIG. 3B), switch X is on and switch Y is off.

Therefore, when the ignition key switch 14 is turned off, the Zener diode Z1 provided between the terminals C and D is short-circuited. When the ignition key switch 14 is turned on, the short circuit is released and the Zener diode Z1 is connected to the circuit between the terminal B and the Z terminal.

Reference numeral 15 designates a key switch operation detection circuit for detecting whether the ignition key switch 14 is normally operated as shown in FIG. 3B. The detection circuit is composed of a first voltage detection circuit 16 , a second voltage detection circuit 17 , and a smoothing circuit 18 . By turning on the ignition key switch 14, switch X is turned on, closing the circuit across terminals A and B. When the switch Y is turned off so that the circuit across the terminals C and D is disconnected, the key switch operation detection circuit 15 is operated, thereby allowing the control circuit 8 to operate by the output of the key switch operation detection circuit 15 .

The zener diode Z2 of the second voltage detection circuit 17 is a protection circuit for operating the key switch when an AC half-wave voltage is input in a so-called battery-off state (when an AC generator is connected as a power supply voltage) Each element of the detection circuit 15 is protected from high voltage.

First, the operation in the ON state of the ignition key switch 14 shown in FIG. 3B will be described. Through the ON operation of the key switch 14, the voltage V _B is applied to the BAT terminal (power supply terminal) of the second voltage detection circuit 17 of the key switch operation detection circuit 15 through the DC power supply 1 or the AC generator 11, and is passed through the power supply terminal of the switch X. Terminal A→terminal B→zener diode Z1→terminal D of switch Y applies the voltage V _Z to the Z terminal (detection terminal) of the first voltage detection circuit 16 .

As for the voltage on the BAT terminal, the voltage V _B is applied to the emitter terminal of the transistor Q2 through the resistor R1. The voltage at the Z terminal turns on transistor Q3 through resistor R5 and applies it to resistor R3. Thus, the collector voltage of transistor Q3 is nearly equal to the voltage V _Z at terminal Z. Thus, transistor Q2 is turned on and charges capacitor C5 through resistor R6 as long as the condition (V _B >V _Z ) due to the voltage drop of Zener diode Z1 is met. When the capacitor C5 has a voltage equal to a predetermined value, the transistor Q4 is turned on, and the ignition operation permission is given to the control circuit 8 . This state corresponds to the result of judging that the ignition key switch 14 is operating normally.

Next, it will be described with reference to the operation waveform diagram of FIG. Terminal (detection terminal) in the case of key switch operation detection circuit 15 work.

The AC half-wave voltage of Fig. 4(a) is applied to the BAT terminal and the Z terminal. The AC half-wave voltage is smoothed by capacitor C1 as shown in Fig. 4(b), and provided as the power supply for the ignition device. In the AC half-wave voltage waveform at the Z terminal, its voltage is ΔV _Z1 lower than the AC half-wave voltage waveform at the BAT terminal, this value corresponds to the voltage drop caused by the Zener diode Z1, as shown in Fig. 4(a) Show. The voltage applied to the BAT terminal is clamped by the Zener diode Z2 for avoiding input overvoltage of the second voltage detection circuit 17 in the battery disconnected state when the voltage is equal to or higher than a predetermined voltage value, eg, 30V. Thereafter, the capacitors C3 and C4 of the second and first voltage detection circuits 17 and 16 hold each input voltage for a predetermined time. They are shown in Fig. 4(c). In a state where the AC half-wave voltage of the AC generator 11 is higher than the above-mentioned predetermined voltage and is clamped by the Zener diode, that is, during a time interval in which a current flows in the Zener diode Z2, the transistor Q2 is reversed. bias, so transistor Q2 does not work. Other operations are similar to this when the DC power source 1 is present.

As shown in Figure 4(d), for those moments during which the AC half-wave voltage rises, transistor Q2 operates for a period of time (i.e., the period for which the potential difference between capacitors C3 and C4 corresponds to the voltage drop of Zener diode Z1 ) is equal to a very short time t1. However, when the AC half-wave voltage becomes weak, since each input voltage waveform of capacitors C3 and C4 (preferably the capacitance value of C4 ≥ the capacitance value of C3) is maintained for a predetermined time, the period of operation of transistor Q2 is equal to A longer time t2, and the charging and smoothing operation of the capacitor C5 are performed at the timing shown in FIG. 4(e). Therefore, even when an AC half-wave voltage is input, the transistor Q4 does not perform an unstable operation. That is, at this moment (the smoothed voltage V _C5 remains at a voltage equal to or higher than the threshold at which transistor Q4 can operate. Subsequent operation is similar to that in the presence of DC power supply 1. As a result, even at In the battery disconnected state, stable operation can also be performed in a similar manner to the case of using the DC power supply 1 .

A phenomenon will now be described with reference to FIG. 5, even if someone tries to forcibly short-circuit the ignition key switch 14 by using a wire or the like from an external terminal, or in a state where the ignition key switch 14 is not operated (the state of FIG. 3A) I lowered it to release to start the ignition, the ignition still wouldn't work.

The state of No. 1 in FIG. 5 shows a situation in which the ignition key switch 14 normally operates as described above. The emitter voltage of transistor Q2 is equal to V _B , and the collector voltage of transistor Q3 is equal to (V _B -V _Z ). Therefore, the voltage of the capacitor C5 is equal to a predetermined value V _ON or more, the transistor Q4 is turned on, an activation signal is output to the control circuit 8, and the ignition can be operated.

The state No. 2 in FIG. 5 relates to a case where a circuit spanning between terminals A and D is short-circuited with a wire or the like. In this case, since the Zener diode is shorted by the switch X, the voltage at the BAT terminal and the voltage at the Z terminal are both _VB , so the emitter voltage of transistor Q2 and the collector voltage of transistor Q3 are also the same potential, while transistor Q2 is not turned on. Like this, no voltage is applied on the capacitor C5, and there is no start signal transmission from the key switch operation detection circuit 15 to the control circuit 8, so the ignition device does not start.

The state of No. 3 in FIG. 5 relates to a case where a circuit spanning between terminals A and B is short-circuited. In this case, in a similar manner as in the case of No. 2 above, the voltages at the BAT terminal and the Z terminal are the same potential V _B , and the ignition is not activated.

The state of No. 4 in FIG. 5 relates to a case where a circuit spanning between terminals B and D is short-circuited with a wire or the like. In this case, since no voltage is applied from the DC power source 1 or the AC generator 11, the voltages at the BAT terminal and the Z terminal are equal to zero potential, and the ignition is not activated.

The state of No. 5 in FIG. 5 relates to a case where a circuit across the circuit between the terminals A and D and a circuit between the terminals A and B is short-circuited with a wire or the like. In this case, in a similar manner to the cases of No. 2 and No. 3 above, the voltages at the BAT terminal and at the Z terminal are set to the same potential V _B , and the ignition is not activated.

The case of No. 6 in FIG. 5 relates to a case where a circuit spanning between terminals A and D and a circuit between terminals B and D are short-circuited with an electric wire or the like. In this case, the voltages at the BAT terminal and at the Z terminal are set to the same potential V _B in a similar manner to the case of No. 2 above, and the ignition is not activated.

The state of No. 7 in FIG. 5 relates to a case where the circuit across the terminals A and D is short-circuited and the BAT terminal is disconnected. In this case, the voltages at the BAT terminal and the Z terminal are set to the same potential V _B in a similar manner to the case of No. 2 above, and the ignition is not activated.

The state of No. 8 in FIG. 5 relates to a case where the circuit across between the terminal A and the terminal B is short-circuited, and the Z terminal is disconnected. In this case, in a similar manner to the case of No. 2 described above, the voltages at the BAT terminal and at the Z terminal are set to the same potential V _B , and the ignition is not activated.

In each of the states of No. 9 to 12 in Fig. 5, in a manner similar to the case of No. 4, since no voltage is applied from the DC power source 1 or the AC generator 11, at the BAT terminal and at the Z terminal The voltage is equal to zero potential, and the ignition does not start.

In the above-described embodiment shown in FIG. 2, although the Zener diode Z1 is used as the non-linear element provided in the ignition key switch 14, even if as shown in FIGS. 6A and 6B, the Zener diode Z1 is not used. The similar function and effect can still be obtained by using the transistor Q5 or the diode Za.

As described above, according to the present invention, even when the driving power source of the ignition device is any one of the DC power source 1 and/or the AC generator 11, as long as the ignition key switch 14 works normally and the switch X is turned on and the switch Y is turned off The potential difference across the terminals of the non-linear element provided in the ignition key switch 14 is detected by the key switch operation detection circuit 15 (the detection circuit is composed of a first voltage detection circuit 16, a second voltage detection circuit 17, and Smoothing circuit 18 constitutes), just can start ignition device by this. It is extremely difficult to start the ignition by shorting the circuit across the terminals of the ignition key switch 14, by grounding each terminal, and the like. In other words, without knowing the operating characteristics of the non-linear element built into the ignition key switch 14, the ignition circuit cannot be activated. When a parameter such as the voltage to be applied is changed, the operating characteristics of the nonlinear element vary greatly, so it is quite difficult to know its operating characteristics.

According to the present invention described in detail above, even when the starting power source of the ignition device is a DC power source or an AC generator, the engine can be started with the ignition key switch 14 normally operating. However, it is quite difficult to start the engine by shorting or opening the circuit across the external terminals of the ignition key switch.

Claims (5)

1. ignition mechanism is characterized in that comprising:

The power supply that comprises DC power supply and/or generator;

Be used for producing the dc voltage generation circuit of dc voltage according to control signal when when described power supply provides electric power;

Be used for capacitor to the output voltage charge or discharge of described dc voltage generation circuit;

Be used for carrying out the spark coil of ignition operation by the discharge current of described capacitor;

Comprise the ignition key switch that is used for first switch that on/off connects and is used for carrying out the second switch of disconnection/making operation chainly between described power supply and described dc voltage generation circuit with the on/off operation of described first switch;

Impedor with first and second terminals of two terminals that are connected to described second switch respectively, described second terminal are connected to the tie point between described first switch and the described dc voltage generation circuit;

Be used to detect voltage,, produce the voltage check device of an output signal according to the voltage that records at the described impedor first and second terminal places; And

Be used for controlling the control gear of operation of the discharge of described dc voltage generation circuit and/or described capacitor according to the output signal of described voltage check device.

2. device as claimed in claim 1 is characterized in that described control gear comprises and is used for the thyristor that the output signal according to pulser coil allows the electric charge of described capacitor discharge.

3. device as claimed in claim 1 or 2 is characterized in that described impedor comprises a nonlinear element.

4. as any described device of claim 1 to 3, it is characterized in that described voltage check device comprises:

First voltage detecting circuit, described circuit has first and keeps capacitor and the first transistor, described first keeps capacitor to be used for remaining on the voltage at described impedor the first terminal place when described voltage has AC half-wave waveform, works when the voltage of described the first transistor at described the first terminal place is equal to or greater than a predetermined voltage;

Second voltage detecting circuit, described circuit has Zener diode, second and keeps capacitor and transistor seconds, described Zener diode is used for when described voltage has AC half-wave waveform voltage clamp with the described impedor described second terminal place to a predetermined voltage, described second keeps capacitor to be used to keep described by the voltage of clamp, and the pressure drop that described transistor seconds causes owing to described impedor when the voltage at described the first terminal place is worked when being lower than the described second terminal place voltage; And

Smoothing circuit, described smoothing circuit has smmothing capacitor and the 3rd transistor, described smmothing capacitor is used for the output voltage of level and smooth described second voltage detecting circuit when described output voltage has pulsating waveform, and described the 3rd transistor voltage power supply level and smooth according to described process.

5. device as claimed in claim 4, the described transistor seconds that it is characterized in that described second voltage detecting circuit carries out work in response to the trailing edge of described AC half-wave waveform, with to described smmothing capacitor charging.

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