JPS6228707Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an internal combustion engine emergency stop device that stops the engine when an abnormality in the internal combustion engine is detected.

If an abnormal situation occurs, such as when the oil level in an internal combustion engine drops below a predetermined value or when the engine overheats, it may be necessary to immediately detect this and bring the engine to an emergency stop. . The present applicant has previously developed an emergency stop device (Utility Model No. 57) that stops the engine by temporarily tripping the circuit breaker and stopping the ignition operation of the internal combustion engine ignition device when an abnormal situation occurs in the engine. -51169) was proposed. However, in this device, a detection switch that closes when an abnormal situation is detected is connected in series with the circuit breaker, and when an abnormal situation occurs, a current of a predetermined level or higher is passed through the detection switch to the circuit breaker. Because the circuit breaker was opened by the switch, the large current needed to operate the circuit breaker had to be passed through the detection switch.
A drawback is that a detection switch with a large current capacity must be used.

An object of the present invention is to provide an internal combustion engine emergency stop device that can operate a circuit breaker using a small-capacity detection switch.

The present invention includes a circuit breaker inserted into a control circuit of an ignition device for an internal combustion engine that performs ignition operation by the output of one half cycle of an ignition power supply coil that outputs an alternating current voltage in synchronization with the rotation of the internal combustion engine;
A detector that performs a detection operation when an abnormal situation occurs and becomes conductive or disconnected, and a circuit breaker that causes a current of a predetermined level or higher to flow through the circuit breaker when the detector performs a detection operation. In an internal combustion engine emergency stop device that stops the internal combustion engine by stopping the ignition operation of the internal combustion engine ignition device when the circuit breaker breaks, a large current is applied to the detector. The detector is designed to prevent the flow of water, so that a small and inexpensive detector can be used.

Therefore, in the present invention, the breaker drive circuit is provided with a thyristor for detecting an abnormal situation, a thyristor for driving the breaker, and a thyristor firing circuit for driving the breaker that fires the thyristor for driving the breaker.

The abnormal situation detection thyristor is configured such that the ignition power supply coil is oriented so that a forward voltage is applied between the anode and the cathode at the output voltage of the other half cycle that does not contribute to the ignition operation. are connected in parallel.

The breaker driving thyristor is connected in series with the circuit breaker and in parallel with the ignition power coil oriented so that a forward voltage is applied between the anode and cathode by the output voltage of the other half cycle of the ignition power coil. It is connected to the.

The thyristor ignition circuit for driving the breaker turns on the thyristor for breaker driving when the output voltage of the other half cycle that appears at both ends of the ignition power supply coil reaches a set value when the thyristor for abnormal situation detection maintains the OFF state. Gives an arc signal.

In addition, when the detector is not performing a detection operation, it gives an ignition signal to the abnormal situation detection thyristor using the output voltage of the other half cycle of the ignition power supply coil, and when it performs a detection operation, it fires the abnormal situation detection thyristor. It is connected to the gate circuit of the abnormal situation detection thyristor so as to prevent the signal from being applied.

The circuit breaker is set so that a current of a predetermined level or higher flows through the circuit breaker when the breaker driving thyristor is conductive, and the circuit breaker is cut off when the breaker driving thyristor is conductive.

In the above configuration, when no abnormal situation occurs and the detector is not performing detection operation, the abnormal situation detection signal is used every time the ignition power supply coil generates the output voltage of the other half cycle that does not contribute to the ignition operation. The thyristor conducts and shorts the output of the other half cycle. Therefore, in this case, the breaker driving thyristor is not fired and the breaker driving thyristor remains in the OFF state, so that only a current lower than the predetermined level flows through the circuit breaker, and the circuit breaker is turned off. The breaker does not trip. At this point, the ignition operation is performed normally and the engine is operated normally.

On the other hand, if an abnormal situation occurs and the detector operates, the abnormal situation detection thyristor will remain in the off state, so the output voltage of the other half cycle of the ignition power supply coil will reach the set value. When a firing signal is given to the breaker driving thyristor,
The thyristor becomes conductive. This causes a predetermined level of current to flow through the circuit breaker, causing the breaker to break. Therefore, the ignition operation stops and the engine misfires and stops.

With the above configuration, the detector that detects an abnormal situation only needs to have a capacity to turn on and off the firing signal of the abnormal situation detection thyristor, so a detector with a small capacity can be used as the detector. , it is possible to reduce costs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below along with embodiments thereof with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 indicates a primary coil 1a and a secondary coil 1.
2 is an ignition coil wound around an iron core, and 2 is a spark plug attached to a cylinder of an engine (not shown) and connected to a secondary coil 1b. One end of the primary coil 1a is grounded together with one end of the secondary coil 1b,
A collector of an NPN transistor 3 is connected to one end of the primary coil 1a. transistor 3
One end of a resistor 4 is connected to the base of the resistor 4, and a signal coil 5 is connected between the other end of the resistor 4 and ground.
The anode of a thyristor 6 is connected to the connection point between the signal coil 5 and the resistor 4, and the cathode of the thyristor 6 is connected to the emitter of the transistor 3. A resistor 7 is connected between the gate and cathode of the thyristor 6.
However, a series circuit of a diode 8 and a resistor 9 is connected between the anode and cathode.
The collector of the transistor 3 is also connected to the cathode of a breaker driving thyristor 10, and the anode of the thyristor 10 is connected to the emitter of the transistor 3. The gate of thyristor 10 is connected to the cathode of diode 12 through resistor 11, and the anode of diode 12 connects the cathode to 1.
It is connected to the anode of a Zener diode 13 connected to the non-grounded terminal of the secondary coil 1a. One end of a circuit breaker 14 is connected to the connection point between the emitter of the transistor 3, the cathode of the thyristor 6, and the anode of the thyristor 10, and the other end of the circuit breaker 14 is connected to the non-grounded terminal of the primary coil 1a. There is.

The ignition coil 1 is placed in a magnet generator driven by the engine, and the primary coil 1a receives one half-cycle voltage ν _a (hereinafter this voltage will be referred to as a positive voltage) in synchronization with the rotation of the engine. and the voltage ν _b of the other half cycle (hereinafter this voltage will be referred to as a negative direction voltage) are alternately induced. That is, in this example, the primary coil 1a also serves as the ignition power supply coil, and the ignition operation is performed using one half-cycle voltage induced in the primary coil 1a. The primary _coil Thyristor 15 for abnormal situation detection with the cathode on both ends of 1a on the ground side
are connected in parallel, and one end of a resistor 16 is connected to the gate of the thyristor 15. The cathode of a diode 17 is connected to the other end of the resistor 16, and a detector 18 consisting of a reed switch that opens when an abnormal situation is detected between the anode of the diode 17 and the non-grounded terminal of the primary coil 1a is connected. has been done.

The circuit breaker 14 is provided with an operator 14a that is located at different positions when it is set in the closed state and when it is in the breaker operation.
The closed state can be set by operating 4a. As this circuit breaker, for example, a kind of bimetal is used, and the bimetal is made to self-heat by supplying electricity.
It is possible to use a device in which, when the applied current reaches a predetermined value, the bimetal reverses to open the contact and displace the operator to indicate that the opening operation has been performed. When such a circuit breaker is used, there is a certain delay (thermal response) in its operation, and the circuit breaker is cut off after a certain period of time has passed after a predetermined current flows.

The detector 18 detects when an abnormal condition that requires stopping the engine occurs and becomes conductive or disconnected. This is a condition where the oil level has fallen below the specified level or the engine temperature has become excessive (overheat condition).
In this embodiment, a state in which the oil level of the engine falls below a specified level is assumed to be an abnormal state. The detection device for detecting the oil level is, for example, a detector 18 consisting of a float with a magnet that moves up and down to follow the oil level, and a reed switch that is driven by the magnet of the float when the float falls to a predetermined level. It is composed of

In the embodiment described above, when no abnormal condition occurs, the detector 18 is in a conductive state and the circuit breaker 14 is closed. Therefore, when a negative direction voltage υ _b is induced in the primary coil 1a, the primary coil 1a → detector 18 → diode 17 → resistor 1
A current flows through the path 6 -> the gate cathode of the thyristor 15 -> the primary coil 1a, and an ignition signal is given to the thyristor 15. As a result, thyristor 15
maintains a conductive state for almost the entire half cycle in which the negative direction voltage υ _b is generated (a half cycle that does not contribute to the ignition operation), shorts the primary coil 1a, and applies a reverse voltage between the collector and emitter of the transistor 3. It also prevents the thyristor 10 from becoming conductive, thereby preventing the circuit breaker 14 from operating. Primary coil 1a has positive direction voltage υ
When _a is generated, primary coil 1a → signal coil 5 →
A base current flows through the transistor 3 through the path of the resistor 4 -> the base emitter of the transistor 3 -> the circuit breaker 14 -> the primary coil 1a, and the transistor 3 becomes conductive. As a result, the primary coil 1a
from transistor 3 and circuit breaker 14
A primary current flows through it. The circuit breaker 14 is designed not to break easily due to this primary current.

The signal coil 5 is disposed within the magnet generator or a suitable signal generator, and induces a signal υ _c at an engine ignition position set at a position where the primary current becomes sufficiently large. When the signal υ _c is generated, a firing signal is applied to the thyristor 6, so that the thyristor 6 becomes conductive, and the base current flowing through the transistor 3 is bypassed from the transistor. As a result, the transistor 3 is turned off, and the primary current is cut off. Since this primary current is rapidly interrupted, a large magnetic flux change occurs in the iron core of the ignition coil 1, and a high voltage is induced in the secondary coil 1b. This high voltage generates a spark in the spark plug 2, and the engine is ignited. If the oil level of the engine falls below a specified level, the detector 18 is turned off and the supply of the ignition signal to the thyristor 15 is blocked. At this time, even if a negative voltage υ _b is induced in the primary coil 1a, the thyristor 15 does not conduct, so the negative voltage υ _b is applied to the circuit breaker 1.
4 in the forward direction between the anode and cathode of the thyristor 10. The negative direction voltage υ _b is also caused by the Zener diode 13, diode 12, and resistor 1.
1 and the gate-cathode circuit of the thyristor 10, so when the negative direction voltage υ _b reaches the Zener level of the Zener diode 13, an ignition signal is given to the thyristor 10. Therefore, when the detector 18 detects an abnormal situation and opens, when a negative direction voltage υ _b is induced in the primary coil 1a, the thyristor 10 becomes conductive and the primary coil 1a
→Circuit breaker 14→Thyristor 10→1
A current larger than the primary current flows in the path of the secondary coil 1a. As a result, circuit breaker 1
4 operates to cut off the emitter of the transistor 3 from the primary coil 1a. At this time, the operator 14a of the breaker 14 is moved to the closed position, so that it is possible to know that an abnormality has occurred by visually checking the position of the operator. Further, since the emitter of the transistor 3 is disconnected from the primary coil 1a, ignition operation is no longer performed and the engine is stopped.

In the above embodiment, the transistor 3, the resistor 4, the signal coil 5, the thyristor 6, the resistors 7 and 9
The primary current control circuit for the ignition coil is composed of the diode 8 and the ignition coil 1, and the ignition coil 1 and the spark plug 2 constitute an ignition device for an internal combustion engine. Further, the resistor 11, the diode 12, and the Zener diode 13 keep the abnormal situation detection thyristor 15 in the off state (the detector 18 performs a detection operation to detect an abnormal situation), and the ignition power supply coil (in the above embodiment) In this case, a thyristor firing circuit is constructed which gives a firing signal to the breaker driving thyristor when the negative voltage appearing across the primary coil 1a) reaches a set value, and this firing circuit and the breaker driving thyristor 10 are connected to each other. , a thyristor 15 for detecting an abnormal situation, a resistor 16, a diode 17, and a detector 18 constitute a breaker drive circuit.

As mentioned above, in the present invention, the detector 18
is provided in the gate circuit of the thyristor 15 for detecting an abnormal situation in the breaker drive circuit, and the detector turns on and off the firing signal of the thyristor.
Only a small amount of current flows through the detector, and a detector with a small current capacity can be used as the detector.

In the above embodiment, the detector 18 is turned off when an abnormal situation occurs, but the detector 18 may be turned on when an abnormality occurs, and in this case, as shown in FIG. Detector 18 as shown in
is connected between the gate and cathode of the thyristor 15. In the embodiment shown in FIG. 2, the detector 1
During the half cycle in which negative direction voltage υ _b is generated in the primary coil 1a because the voltage 8 is in a disconnected state, the primary coil 1
A firing signal is given to the thyristor 15 through the resistor 16 and the diode 17, and the thyristor 1
5 is conductive. When the detector 18 becomes conductive during an abnormality, the supply of the ignition signal to the thyristor 15 is blocked, so the thyristor 15 becomes unable to conduct.
A large current flows through the circuit breaker 14 and the thyristor 10 when the negative direction voltage υ _b is generated. This causes the circuit breaker 14 to shut off and stop the ignition operation. Other points are similar to the embodiment shown in FIG.

Figure 3 shows an embodiment in which the configuration of the engine stop circuit is modified; in this example, transistor 3
The emitter is connected to the non-ground terminal of the primary coil 1a. The circuit breaker 14 is connected between the cathode of the thyristor 6 and the non-ground terminal of the primary coil 1a, and the resistor 7 is connected between the gate of the thyristor 6 and the non-ground terminal of the primary coil. . Further, the cathode of the diode 20 is connected to the anode of the thyristor 10, and the diode 2
The anode of 0 is connected to the primary coil 1a through the resistor 21.
connected to the non-grounded terminal of the Other points are similar to the embodiment shown in FIG.

In the embodiment shown in FIG. 3 as well, when the detector 18 detects an abnormality and becomes OFF, and the thyristor 15 becomes unable to conduct, the thyristor 10 becomes conductive and causes a large current to flow through the circuit breaker 14. ,
The circuit breaker 14 is turned off. At this time, the thyristor 6 is disconnected from the emitter of the transistor 3, so the ignition operation is no longer performed.
Ignition operation stops. Since the anode current is supplied to the thyristor 10 through the resistor 21 and the diode 20 even after the circuit breaker 14 opens, the thyristor 10 becomes conductive during the half cycle when the negative direction voltage υ _b is induced in the primary coil 1a, and the transistor 3 This prevents a reverse voltage from being applied between the collector and emitter of the device. That is, in this embodiment, under normal conditions, when the negative direction voltage υ _b is generated, the thyristor 1
The thyristor 5 becomes conductive to protect the transistor 3 from reverse voltage, and in the event of an abnormality, the thyristor 10 becomes conductive and protects the transistor 3 when a negative voltage is generated.

In the above embodiment, if a thermally responsive circuit breaker such as a bimetallic circuit breaker is used, if the contacts of the detector 18 cause chattering, or if the oil level is above the specified value, vibration may occur. If the contacts of the detector 18 are closed due to
4 can be prevented from opening.

In the above embodiment, a reed switch is used as the detector 18, but a detector using a temperature-sensitive resistance element such as a thermistor may also be used. For example, when it is in contact with oil, it is cooled by the oil and exhibits high resistance (substantially a dead state), and when it is no longer in contact with oil, its temperature rises and shows low resistance (substantially conductive state). The oil level detector can be configured with a heat-generating thermistor.

In the above embodiment, the primary coil 1a also serves as the ignition power supply coil, but the ignition coil may be provided outside the magnet generator and the ignition power supply coil may be provided separately within the magnet generator. The ignition power supply coil may be connected in parallel to the primary coil 1a.

As described above, according to the present invention, the detector only needs to have a current container that can turn on and off the gate current of the thyristor, so a small and inexpensive detector can be used, reducing costs and making the device compact. It is possible to achieve

[Brief explanation of the drawing]

1 to 3 are connection diagrams showing different embodiments of the present invention, respectively. 1...Ignition coil, 2...Spark plug, 3...
Transistor, 4, 7, 9, 11, 16, 21...
...Resistor, 6,10,15...Thyristor, 14...
...circuit breaker, 18...detector.

Claims (1)

[Claims for Utility Model Registration] A service inserted into the control circuit of an ignition device for an internal combustion engine that performs an ignition operation based on the output of one half cycle of an ignition power supply coil that outputs an alternating current voltage in synchronization with the rotation of the internal combustion engine. A circuit breaker, a detector that performs a detection operation and becomes conductive or disconnected when an abnormal situation occurs, and a current of a predetermined level or higher flowing through the circuit breaker when the detector performs the detection operation. and a breaker drive circuit that causes the circuit breaker to break, the internal combustion engine emergency stop device stopping the ignition operation of the internal combustion engine ignition device and stopping the internal combustion engine when the circuit breaker breaks. , the breaker drive circuit is configured to direct the ignition power supply in such a way that a forward voltage is applied between the anode and the cathode at the output voltage of the other half cycle that does not contribute to the ignition operation of the output voltage of the ignition power supply coil in both half cycles. an abnormal situation detection thyristor connected in parallel to the coil and rendered conductive when an ignition signal is given by the output voltage of the other half cycle; and a thyristor connected in series to the circuit breaker and connected to the other ignition power supply coil A breaker driving thyristor connected in parallel to the ignition power supply coil in a direction in which a forward voltage is applied between the anode and cathode by a half-cycle output voltage, and the abnormal situation detection thyristor are in a state of failure. a thyristor ignition circuit that provides an ignition signal to the breaker driving thyristor when the output voltage of the other half cycle that appears at both ends of the ignition power supply coil when the ignition power supply coil is held reaches a set value; Allows an ignition signal to be given to the abnormal situation detection thyristor by the output voltage of the other half cycle of the ignition power supply coil when the detection operation is not performed, and when the detection operation is performed, the ignition signal is applied to the abnormal situation detection thyristor. connected to the gate circuit of the abnormal situation detection thyristor so as to prevent an ignition signal from being applied to the thyristor, and so that a current of a predetermined level or higher flows through the circuit breaker when the breaker driving thyristor is conductive. An internal combustion engine emergency stop device.