JP2696641B2 - Engine speed control and stop device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine speed control device for controlling an engine speed by rotating an engine governor lever by a controller, a driver and a throttle motor, and outputs a signal to a driver for driving the throttle motor. The present invention relates to a device that enables an engine speed to be controlled by an external switch and an engine to be stopped by turning off a key switch, even when a controller that fails is out of order.

[0002]

2. Description of the Related Art Conventionally, in an engine speed control device using a throttle motor, a driver for driving the throttle motor controls the engine speed and stops the engine only by a signal from a controller. Therefore, when the controller fails and cannot operate normally, there is a disadvantage that the engine cannot be stopped by controlling the engine speed and turning off the key switch.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object that a controller for outputting a signal to a driver for driving a throttle motor breaks down and that it is impossible to adjust the engine speed. It is an object of the present invention to provide a device that does not become impossible to control and stop the engine speed.

[0004]

In order to achieve the above object, according to the present invention, a key switch ON / OFF signal input circuit is connected to a controller and a driver. The driver is connected to the power supply via a battery relay that operates by turning on and off the key switch, while the controller has a function of rotating to the stop side. 0N, 0FF Connected to the power supply via a redundant relay operated by 0FF, and a circuit for issuing a command of the direction of rotation of the throttle motor to the driver by an external switch is provided in addition to a circuit for issuing a command of the direction of rotation of the throttle motor from the controller to the driver. It is a thing.

[0005]

When the controller is operating normally, the controller receives a throttle setting device (not shown) and an ON / OFF signal of a key switch. This is performed by outputting a cw signal (a signal for rotating the throttle motor clockwise) or a ccw signal (a signal for rotating the throttle motor counterclockwise) from the controller to the driver. If it is not possible, the above signals are applied directly to the driver without the intervention of a controller to control and stop the engine speed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.
Reference numeral 1 denotes a throttle motor, which is driven by a signal sent from a control circuit 2c of a driver 2 including an input determination device 2a, an interface 2b, a control circuit 2c, and a power supply circuit 2d. Reference numeral 3 denotes a controller including an input determination device 3a, an interface 3b, a CPU (Central Processing Unit) 3c, an A / D converter 3d, and a power supply circuit 3e. The interface 3b of the controller 3 is cw
A circuit 4 for transmitting a signal (a signal for rotating the throttle motor 1 clockwise) and a circuit 5 for transmitting a ccw signal (a signal for rotating the throttle motor 1 counterclockwise) are connected in parallel to the interface 2b of the driver 2. I have. The branch circuit 6 of the circuit 4 for transmitting the cw signal is grounded via an external switch 7, and the branch circuit 8 of the circuit 5 for transmitting a ccw signal is grounded via an external switch 9. Further, an ON / OFF signal input circuit 11, 1, 1 via a key switch 10 is provided to an input determination device 2 a of the driver 2 and an input determination device 3 a of the controller 3.
The input determination device 2a of the driver 2 is connected to the control circuit 2c via an interface 2b built in the driver 2, and the input determination device 3a of the controller 3 is connected to the interface 3b built in the controller 3. Connected to each other. An A / D converter 3d for converting the voltage of the interface 3b and the throttle setting device 21 into a digital value is connected to the CPU 3c of the controller 3, and the A / D converter 3d is connected to the throttle setting device 21. . Further, the power supply circuit 2d of the driver 2 is connected to the main power supply by a circuit 14 via a battery relay 13 which is operated by turning on and off the key switch 10, and the power supply circuit 3e of the controller 3 is connected to the battery relay 13 and the redundant switch 15 It is connected to the main power supply by a circuit 17 via a redundant relay 16 which is activated by ON and OFF. The battery relay 13 can be operated by the alternator 18 even when the key switch 10 is turned off. Also, the downstream side of the key switch 10 of the circuit 22 connecting the exciting coil 13a of the battery relay 13 and the main power source and the exciting coil 1 of the battery relay 13
Diodes 24 and 25 that allow current to flow in only one direction are provided in a circuit 23 that connects the alternator 18 to the switch 3a. Further, the throttle motor 1 is connected to an engine governor lever 20 via a rod 19.

Next, the operation of the present invention will be described. 1) When the redundant switch 15 is turned off and the controller 3 operates normally. When the key switch 10 is turned on while the redundant switch 15 is in the off state, the exciting coil 13a of the battery relay 13 is excited and the battery relay 13 is turned on, and the power supply circuit 2d of the driver 2 and the power supply circuit 3e of the controller 3 are turned on. Power is supplied and key switch 10 is turned on.
The signal is input determination device 2 of driver 2 and controller 3
a and 3a. An increase / decrease signal of the engine speed is input to the A / D converter 3d of the controller 3 by the throttle setting device 21, and the signal is converted from a voltage (analog value) to a digital value by the A / D converter 3d. Thereafter, the signals are transmitted as a cw signal and a ccw signal from the interface 3b to the interface 2b of the driver 2 via the CPU 3c, and the throttle motor 1 is driven via the control circuit 2c of the driver 2. When the key switch 10 is turned OFF in this state, the key switch 10 is turned ON and O.
The signals of the FF signal input circuits 11 and 12 are cut off, and the engine is stopped by turning the engine governor lever 20 to the engine stop position by the throttle motor 1.

2) When the controller 3 does not operate normally because the redundant switch 15 is turned off. In this case, by turning on the key switch 10, the exciting coil 13a of the battery relay 13 is excited and the battery relay 13 is turned on.
and the power supply circuit 3e of the controller 3 is supplied with power, and the ON signal of the key switch 10 is supplied to the input determination device 2a of the driver 2 and the input determination device 3a of the controller 3.
However, since the controller 3 does not operate normally, the cw signal, ccw
The signal is not transmitted, and the engine speed control and the engine stop of the above 1) cannot be performed. Accordingly, in this case, a cw signal is transmitted from the external switch 7 and a ccw signal is transmitted from the external switch 9 to the driver 2.
To control the engine speed. Further, even when the controller 3 does not operate normally, when the key switch 10 is turned off, an OFF signal of the key switch 10 is input to the driver 2, and the driver 2 can stop the engine by receiving this signal.

3) When the redundant switch 15 is ON. When the redundant switch 15 is turned on, the exciting coil 16a of the redundant relay 16 is excited and the redundant relay 16 is turned off, and the power supply to the power supply circuit 3e of the controller 3 is cut off. In the case of the above 2), c is set by the external switch
A w signal and a ccw signal are transmitted to the driver 2 by the external switch 9 to control the engine speed and turn off the key switch 10 to thereby control the driver 2.
, An OFF signal of the key switch 10 is input, and the driver 2 can stop the engine in response to this signal.

[0010]

According to the present invention, even if the controller 3 fails and becomes inoperable, the signal is transmitted to the driver 2 to control the engine speed by the configuration described in detail in the above embodiment. In addition, a remarkable effect is achieved such that the engine can be stopped by turning off the key switch.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Throttle motor 2 Driver 3 Controller 7 External switch 9 External switch 10 Key switch 13 Battery relay 15 Redundant switch 16 Redundant relay 20 Engine governor lever

Claims (1)

(57) [Claims] An engine speed control device for controlling an engine speed by rotating an engine governor lever (20) by a controller (3), a driver (2) and a throttle motor (1). ) Of the key switch 10 to a controller (3) that outputs a signal to a driver (2) that drives
ON / OFF of a circuit (17) for supplying power via a battery relay (13) and a redundant relay (16) operated by an alternator 18 and a key switch (10)
A signal input circuit (12) is connected , and a driver (2)
To the ON signal of the key switch 10 to the alternator 18
ON / OFF of a circuit (14) for supplying power through a battery relay (13) operated by a key switch (10) and a key switch (10)
FF signal input circuit (11) is connected, and key switch 10
The throttle motor 1 is rotated by the OFF signal of
The circuit (4, 5) for issuing a command for the rotation direction of the throttle motor (1) from the controller (3) to the driver (2) and the external switch (7, 9) and the driver (2) can be stopped. An engine speed control and stop device for a construction machine or the like, comprising a circuit (6, 8) for issuing a command for a rotation direction of a throttle motor (1).