JPS6225874B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

TECHNICAL FIELD The present invention relates to an engine stop control device for an engine, particularly an engine mounted on a vehicle, a general-purpose engine, and the like.

[Conventional technology and problems]

In general, the above-mentioned types of engines are operated in addition to the main switch for normal starting and stopping, as well as when there is an abnormality in the engine, such as when the lubricating oil and fuel level falls below a predetermined level, or when the cooling water temperature rises above the set temperature. An emergency stop device is installed to stop the engine. By the way, if such a stop device operates automatically and frequently, especially in general-purpose engines,
There are problems such as damaging the water suction pumps driven by this, or loading devices such as construction and work machines, or interfering with the operation of the loading devices, and furthermore, creating a danger. In addition, in-vehicle engines are configured to issue an alarm without automatically stopping the engine in the event of an abnormality, such as when the amount of lubricating oil drops below a predetermined amount. Afterwards, the engine can be restarted even if the above-mentioned abnormality remains unresolved, which increases the risk of restarting the engine and may even damage the engine. In addition, as a prior art technology, a switch is installed that turns on when the engine oil level in the engine oil pan drops below a specified oil level, and the engine is automatically stopped at the same time as a warning is issued, making it impossible to start the engine unless this condition is restored. There is Utility Model Publication No. 51-19139. If the system automatically stops at the same time as the warning is issued, there is a problem in that an unexpected accident may occur in an external device that operates using the power source from the engine. The present invention has been made in view of the above points, and provides a warning that an abnormal condition occurs during engine operation, but does not automatically stop the engine, but activates a manual engine stop device as necessary. ,
In addition, after the engine has stopped, it will not be possible to restart it without using a manual engine stop device unless the abnormality has been resolved.
It is an object of the present invention to provide a highly safe engine stop control device that solves the above problems.

[Means to solve the problem]

In order to achieve the above object, in the present invention,
A stop means has a switch element with a gate pole connected to the ignition circuit of the engine via a rectifier, and makes the ignition circuit in a state incapable of ignition by conduction of the switch element, and a switch with a gate pole in the stop means when the engine is running. A manual switch that applies an operating current to the gate electrode of the element and activates a stop means to stop the engine, an alarm device, a sensor contact that detects engine abnormality, and a capacitor that stores the voltage generated when the engine is running. An engine stop control circuit consisting of a control circuit in which a transistor circuit biased by the voltage of the capacitor is connected in series with the sensor contact and the alarm device, and a diode circuit that connects the output of the transistor circuit to the gate pole of the gate pole switch element. Configure the control device.

[Effect]

According to this, the stopping means has a switch element with a gate pole connected to the ignition circuit of the engine via a rectifier, and makes the ignition circuit in a state incapable of ignition by conduction of the switch element, and the stopping means when the engine is running. The engine stop circuit consists of a manual switch that applies an operating current to the gate pole of a switch element with a gate pole and activates a stop means to stop the engine. The alarm device circuit that detects an abnormality and generates an alarm consists of a transistor circuit and a diode circuit.
During engine operation, each function operates independently. In addition, when the abnormality does not recover when the engine is restarted after stopping, that is, when the sensor contact that detects the engine abnormality is activated, the output of the control circuit turns off the diode circuit without using a manual switch. The output of the control circuit is applied to the gate pole of the switch element with a gate pole through the gate pole, and the switch element with a gate pole is operated to disable ignition, and a restart is prevented unless the abnormal condition is recovered. It is designed to prevent it.

【Example】

Hereinafter, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a block diagram of an engine stop device to which the present invention is applied. In the figure, A is an engine ignition device having an ignition coil and a generator coil, etc., and B is a block diagram of an engine stop device having an ignition coil and a generator coil. Stopping means for reducing the ignition voltage below the ignition limit value to stop the operation of the ignition device A, C is an automatically reset type normally open switch, and the contact closes only while operating (pressing) force is applied. It performs the operation and sends a stop command signal a to the stop means B. D is a detection means that detects various abnormal conditions related to engine operation and operates an alarm or display, and also issues a stop command to the stop means B in conjunction with the action of a power supply (power supply) circuit P, which will be described later. Send signal a. E is a holding means that receives any one of the above-mentioned stop command signals and holds the operation of the stop means B for a predetermined time; P is a power supply means (circuit) that generates voltage when the engine is running and supplies power to the detection means D;
When the detection means D is activated while the ignition device A is in normal operation, an alarm or the like is immediately generated, but a stop command signal a' is not sent to the stop means B. Then, the user etc. confirms the content of the alarm and operates the switch C as necessary, so that the stop means B receives the stop command signal a from the switch C and lowers the ignition voltage of the ignition device A below the ignition limit value. This can be stopped by reducing the Furthermore, once the stop command signal a or a' arrives, the holding means E holds the operation of the stop means B for the required time regardless of the operation of the normally open switch C or the detection means D.
operation will definitely be stopped. On the other hand, when the operation of the ignition system A is stopped, if the detection means D is in an inoperative state, that is, the abnormality has been recovered, a normal restart can be made, but if the detection means D is not recovered, a stop command signal a' is sent from the detection means D. is sent out and operates the stop means B in the same manner as the operation of the switch C, so restarting is not possible. Hereinafter, the present invention will be explained in detail using the circuit diagram shown in FIG. In the figure, IGC is the ignition coil,
SP is a discharge gap, CP is a contact breaker, and these form the ignition device A. A rotating magnet G rotated by the engine IN is magnetically coupled to the ignition coil IGC, and when the engine IN rotates, an alternating current voltage is generated. Similarly, the power generation coil
AC voltage is also generated in EX-W and the generator coil L-W of the power supply circuit P, forming a so-called generator engine. Rec is a full-wave rectifier that rectifies the AC output of the generator coil EX-W or ignition coil IGC, Th is a thyristor with a gate and pole (hereinafter referred to as thyristor), and impedance elements such as resistors R ₁ and R ₂ are connected in series. connected between the DC output terminals of the rectifier Rec to form the stop means B;
By conducting the thyristor Th, the AC output voltage of the coil EX-W or the ignition coil IGC is short-circuited, the voltage of the ignition coil IGC is reduced below the ignition limit value, and the engine is stopped. A series connected diode D ₁ and a capacitor C ₁ are connected across the resistor R ₂ and also connect the diode
The connection point of D ₁ and capacitor C ₁ is connected to the gate of thyristor Th through resistor R ₃ to stop means B
A holding means E is formed. The switch SW forming the switch C is an automatic return type normally open switch,
It is connected between both ends (anode, cathode) of thyristor Th or between the anode and gate, and the switch
By closing SW, a gate signal (stop command) is applied to thyristor Th. In this embodiment, the power supply circuit P of the detection means D utilizes the AC output of the power generation coil L-W. _D3 is a rectifying diode, Bz and S are an alarm device such as a buzzer, and a semiconductor switching element, which are connected in series and drive the alarm Bz when the switching element S is conductive. Rs, SW ₁ , etc. are contacts of various sensors that detect engine abnormalities (for example, lack of oil), and are designed to close when an abnormality occurs and open when normality or abnormality recovery occurs. _R4 ,
R ₅ , R ₆ , R ₇ , Q, and C ₂ are resistors, transistors, and capacitors that together with the sensor form a control circuit for the semiconductor switching device S;
R ₆ and capacitor C ₂ form an integrating circuit that uses the DC output of rectifier diode D ₃ as an input source, and its value is set sufficiently large, and the connection point of resistor R ₆ and capacitor C ₂ is connected to transistor Q. It is connected to the base, and supplies base current to the transistor Q when the charging voltage of the capacitor _C2 exceeds a predetermined value (voltage between the base and emitter of the transistor Q). The sensor contact has one end connected to the DC output side of the rectifier diode _D3 , and the other end connected to the resistor.
It is connected to the collector of transistor Q via R ₅ and R ₄ . If at least one of the sensors is closed and a base current is supplied to the transistor Q during this time, the transistor Q conducts and causes the switching element S to conduct. The above configuration forms the detection means D. next
D ₂ is one end of the sensing means D, that is, the transistor Q
A diode connected between the collector of the transistor Q and the connection point of the resistor _R4 and the gate of the thyristor Th, when the sensor (such as Rs) is in the operating state and the base current is not supplied to the transistor Q and it is in a non-conducting state, A gate signal (stop command) is applied to the thyristor Th via the diode _D2 . Next, the operation of this circuit will be explained. During normal engine operation During normal operation, ignition system A operates normally.
A predetermined alternating current voltage is generated in the generator coils EX-W and L-W. And in the detection means D,
The integration circuit of resistor R ₆ and capacitor C ₂ is powered through diode D ₃ , and after a predetermined time, the integrated value, that is, the charging voltage of capacitor C ₂ , becomes the base-emitter voltage (V _BE ) of transistor Q. and supplies the base current to the transistor Q. However, since the sensor is inactive, the transistor Q is in an off state because the emitter and collector are not supplied with power, and the detection means D passes through the diode _D2 .
No signal is sent. On the other hand, the stop means B does not operate because the thyristor Th is in a non-conductive state.
Therefore, ignition device A continues normal operation. Operation of detection means D during engine operation Here, as an example of a sensor, an engine oil level detection device will be described with reference to FIG. 4. A float FL having a magnet Mg is slidably engaged with a cylindrical body _G1 fixed to the oil tank, and when the oil level OL of the engine oil falls below a predetermined value, the float FL switches the reed switch Rs. Go down to the position and turn it on (when the oil level is sufficient, the float FL is at the top,
Reed switch Rs is OFF). Therefore, the detection means D
Transistor Q has already been supplied with base current, so when sensor switch Rs is turned on, power supply circuit P → diode D ₃ → sensor Rs → resistors R ₅ , R ₄ →
The collector current Ic of the transistor Q flows through the path of the transistor Q, and the collector and emitter thereof are immediately brought into a conductive state. For this reason, the voltage generated across the resistor _R4 is reduced to the voltage across the semiconductor switching element S.
is applied between the gate and cathode of the switching element S, and the switching element S becomes conductive. As a result, power supply circuit P→
A current flows through the path of diode _D3 → buzzer Bz → semiconductor switching element S, and the alarm operation of buzzer Bz is performed. However, since the transistor Q of the detection means D is in a conductive state and the potential between its emitter and collector is close to zero, the stop command signal is not sent through the diode _D2 .
The thyristor Th of the stop means B remains inactive, and the engine continues to operate. Operation of stopping means and holding means When the user confirms the alarm etc. and applies operating force (pressing force) to the switch SW as necessary to close it,
Meanwhile, generator coil EX-W or ignition coil IGC
According to the generated voltage, _{the capacitor} C ₁
is charged. From the moment the voltage across the resistor R ₂ (impedance element) becomes lower than the charging voltage of the capacitor C ₁ , the charge in the capacitor C ₁ is transferred from the resistor R ₃ to the gate and cathode of the thyristor Th to the resistor R ₂ to the capacitor C _1. This causes a gate current to be supplied to the thyristor Th, thereby turning the thyristor Th into a conductive state.
Once the thyristor Th becomes conductive, it becomes a rectifier.
The generated voltage of the power generation coil EX-W is short-circuited via Rec→resistance _R1 →thyristor Th→resistance _R2 , and the voltage of the ignition coil IGC is reduced to below the ignition limit value. Then, release the operating power of the switch SW,
Even if this returns automatically, the capacitor _C1 is charged via the diode _D1 by the voltage generated across the resistor _R2 when the thyristor Th is conductive, and is discharged at a predetermined time constant via the resistor _R3 . Supplies gate current to As a result, thyristor Th
is maintained in a conductive state for a required period of time, during which time the engine is reliably stopped. After the engine is stopped, no voltage is generated in the generator coil EX-W, so the thyristor Th shifts to the OFF state, and the residual charge in the capacitor _C1 is discharged via the resistors _R3 and _R2 . Engine restart operation when the detection means is activated After the engine is stopped, if the sensor of the detection means, for example in Fig. 4, is filled with oil, the float FL rises, and the reed switch Rs returns to the OFF state, the engine restarts as described above. can operate normally. However, if this does not return and the engine is started with reed switch Rs in the ON state, the generator coil EX
A slight voltage is generated between -W and L-W. Therefore, in the detection means D, the power supply circuit P→diode D ₃
→ reed switch Rs → resistors R ₅ , R ₄ → a circuit around the emitter and collector of transistor Q, and a circuit around diode D ₃ → resistor R ₆ → capacitor C ₂ are formed. However, since the integral value of the resistor R ₆ and the capacitor C ₂ is set sufficiently large, it takes time for the charging voltage of the capacitor C ₂ to reach the base-emitter voltage (V _BE ) of the transistor Q. Therefore, during this time, transistor Q
remains non-conducting. Therefore, during this time, the current in the circuit that goes around the reed switch Rs is the resistance R ₅ ,
R ₇ → is bypassed through the gate and cathode of the semiconductor switching element S, makes the switching element S conductive, and activates the alarm Bz.
Resistor R ₄ → Diode D ₂ → Resistor R ₃ → Thyristor Th
The gate and cathode of the thyristor Th are supplied with power through the resistor _R2 , and the thyristor Th becomes conductive. As a result of which the stopping means and the holding means are activated again,
Engine restart is prevented. As is clear from the above description, according to the present invention,
When the engine is running, the operation of the stopping means and the detecting means are made independent, and after the engine is stopped, the stopping means and the detecting means are operated in conjunction with each other, so that restarting is possible only when the operation of the detecting means is restored. It is highly safe, and has the effects of increasing the protection function of the engine and various devices related thereto, and further enabling load operation suited to the situation. In the above example circuit, an example was explained in which a magnetic generator was coupled to the ignition device, but the generator does not necessarily need to be provided, and in this case,
The power supply circuit P of the detection means D needs to be formed so as to generate voltage when the engine rotates. For example, if a battery or the like is used, power is constantly supplied to the sensor circuit and alarm circuit, and the control circuit of the semiconductor switching element (R ₆ ,
_C2 integrating circuit, etc.) may be supplied with power via a switch means that turns on and off based on the detection output of an engine rotation speed detection circuit, etc. Further, the automatic return type normally open switch SW can be similarly implemented by providing it at both ends of the thyristor Th as shown in FIG. Furthermore, the detection means D may perform an alarm display operation using an indicator lamp such as a light emitting diode with a small power supply capacity instead of a buzzer or the like. In this case, as shown in Fig. 3, the semiconductor switching elements are omitted and the indicator lamps L1 _{to L1} are used.
L ₃ and sensor Rs, SW ₁ , Q ₁ and transistor Q
may be connected in series.

Effects of the Invention As is clear from the above description, according to the present invention, the safety is high, the engine and related devices are protected, and the engine stop control device is adapted to the operating status of the load. This has great practical effects.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an engine stop device to which the present invention is applied, Fig. 2 is an electric circuit diagram showing one embodiment of the invention, Fig. 3 is a circuit diagram showing another embodiment, and Fig. 4 is an oil FIG. 3 is a diagram showing the structure of a sensor. A... Ignition device, B... Stopping means, C... Normally open switch, D... Detecting means, E... Holding means, P... Power supply circuit, IN... Engine, G... Generator, EX-W, L-
W...Generating coil, Th...Thyristor with gate pole,
Bz...Alarm, S...Semiconductor switching element, Q
…Transistor, Rs…Reed switch.

Claims (1)

[Claims] 1. Stopping means having a switch element with a gate pole connected to the ignition circuit of the engine via a rectifier, and rendering the ignition circuit in a state incapable of ignition by conduction of the switch element, and a gate pole attached to the stop means when the engine is running. A manual switch that applies an operating current to the gate pole of the switch element and operates a stop means to stop the engine, an alarm device, a sensor contact that detects engine abnormality, and a capacitor that stores the voltage generated when the engine is operating. An engine comprising a control circuit in which a transistor circuit biased by the voltage of the capacitor is connected in series with the sensor contact and the alarm device, and a diode circuit that connects the output of the transistor circuit to the gate pole of the gate pole switch element. Stop control device.