JPH0428161Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention consists of a generator driven by an engine, a battery charged by the generator, and an emergency stop operated by the power supply from the battery. The present invention relates to an emergency stop device for a work vehicle equipped with actuators for use in a work vehicle.

[Conventional technology]

In this type of work vehicle, various types of sensors are installed in order to automate various tasks or make the tasks easier, and the actuator is automatically operated by a control device based on the detected information. There is. If an abnormality occurs in the work vehicle, such as an abnormal increase in the load on the engine or an abnormal drop in the hydraulic pressure used to operate the work equipment, the emergency stop actuator is automatically activated to bring the vehicle body into emergency. This is done to increase safety.

[Problem that the invention attempts to solve]

By the way, the above control device, sensor, and actuator are configured to operate by being supplied with electric power from a battery charged by a generator driven by an engine. In general, actuators require relatively large power consumption to operate, so they are supplied with power directly from a battery.

On the other hand, in order to prevent control devices and sensors from malfunctioning due to fluctuations in power supply voltage, they are supplied with stabilized power via constant voltage regulators, etc., and are also supplied with stable power through constant voltage regulators, etc. A power filter or the like is also installed to prevent the supply voltage from dropping.

Incidentally, the output voltage of the battery fluctuates in accordance with fluctuations in generator output due to changes in engine load, fluctuations in power consumption due to actuator activation/stopping, and the like.

Therefore, even if an abnormality occurs in the generator and charging to the battery is stopped, the control devices and sensors will continue to operate normally for a long time, and various actuators including the emergency stop actuator will continue to operate normally. However, since the actuator operates as long as the battery can supply power to operate the actuator, there is a risk that the operator may not notice that an abnormality has occurred in the generator. If the work vehicle is used without charging the battery from the generator, the output of the battery will decrease due to power consumption, and the emergency stop actuator will suddenly stop operating at a certain point. There is a risk that the vehicle will not be able to automatically come to an emergency stop when an abnormality occurs.

The present invention was developed in view of the above-mentioned circumstances, and its purpose is to automatically bring the vehicle into an emergency stop when the emergency stop actuator stops working due to the generator not charging the battery. The goal is to prevent things from becoming impossible.

[Means for solving problems]

The characteristic configuration of the emergency stop device for a working vehicle according to the present invention includes: an output voltage monitoring means for monitoring whether the output voltage of the generator is higher than a set voltage; The vehicle is equipped with an automatic stop control means that operates the emergency stop actuator to automatically stop the vehicle body when the output voltage of the generator falls below the set voltage, and its functions and effects are as follows. be.

[Effect]

In other words, by monitoring whether the output voltage of the generator is higher than or equal to the set voltage, it is possible to monitor whether or not the battery is being charged normally, and to detect whether the output voltage of the generator has fallen below the set voltage. Then, the emergency stop actuator is automatically activated to bring the vehicle to an emergency stop. Note that the above set voltage is set based on the rated operating voltage of the emergency stop actuator, etc.

[Effect of idea]

Therefore, the vehicle body can be brought to an emergency stop before the output voltage of the battery drops to a voltage that makes the emergency stop actuator inoperable, so the emergency stop actuator cannot be activated because the generator fails and the battery is not charged. This made it possible to avoid the unexpected situation where an emergency stop could not be performed due to running out of power, thereby increasing safety.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

As shown in Fig. 3, an engine
A working vehicle is constructed by suspending a lawn mower 1 driven by the output of the lawn mower 1 and used for cutting grass, weeds, etc.

To explain the vehicle body V, as shown in FIGS. 2 and 3, a pair of left and right front wheels 2 and a pair of left and right rear wheels 3 are provided, and a steering wheel is provided to operate the pair of front and rear wheels 2 and 3 separately. Hydraulic cylinders 4, 5 and control valves 6, 7 therefor are provided. A hydraulic continuously variable transmission device 8 capable of freely switching between forward and backward speeds and capable of forward and reverse speed change is interlocked with the engine E, and is provided with a speed change pedal 9 for on-board operation and a speed change motor 10 for remote control. . In addition, a steering handle H for boarding and maneuvering is provided.

In order to steer the pair of front and rear wheels 2, 3 by changing their direction, there is a parallel steering type that changes the direction of the front and rear wheels 2, 3 in the same direction.
A four-wheel steering type that changes the direction of the front wheels 2 in the opposite direction to make a sharp turn, and a two-wheel steering type that changes the direction of only the front wheels 2 can be used. The parallel steering type and the four-wheel steering type can be selected during remote control, and any of the three types of steering types can be selected during boarding operation. .

To explain the configuration of remote control, the control valves 6, 7 of the steering hydraulic cylinders 4, 5,
and a receiver 1 that receives instruction information from a control device 11 and a transmitter 12 that give operating commands to each of the variable speed motors 10 and transmits it to the control device 11.
3 is provided.

To explain the configuration of the transmitter 12, there is a gear shift lever 14 that instructs the target shift position of the transmission device 8 by moving back and forth, and a shift lever 14 that instructs the steering type by moving back and forth, and a shift lever 14 that instructs the steering type by moving back and forth. A steering lever 15 is provided for instructing target steering positions of the front and rear wheels 2 and 3. Detection means such as sensors for detecting the operating state and operating position of each of the levers 14 and 15 are provided, and a transmitting device for transmitting the detected information to the receiver 13 is also provided. For safety reasons, the shift lever 14 is biased so that when its operation is stopped, the shift lever 14 automatically returns to a neutral state, that is, the shift position returns to the neutral position N, which is the travel stop position.

Further, a front wheel steering position detection potentiometer R ₁ detects the steering position of the pair of front wheels 2, and a rear wheel steering position detection potentiometer R1 detects the steering position of the pair of rear wheels 3. ₂ , and the transmission device 8
Shift position detection potentiometers R ₃ are provided to detect the position of the shift arm 16, that is, the shift position, and the detection signals from the potentiometers R ₁ , R ₂ , R ₃ are input to the control device 11. be.

In other words, the target shift position instructed by the transmitter 12 and the shift position detection potentiometer
The operation of the speed change motor 10 is controlled so that the speed change position detected by R3 coincides with the speed change position detected by _R3 ,
Further, based on the steering type instruction information, target, and steering position instructed by the transmitter 12, and the detection information of the steering position detection potentiometers R ₁ and R ₂ of the front and rear wheels 2 and 3, respectively,
The control valves 6 and 7 of the steering hydraulic cylinders 4 and 5 are configured to control the operation of the control valves 6 and 7, so that the vehicle body V automatically travels at the designated speed and the front and rear wheels 2 and 3 are controlled. The travel of the vehicle body V can be remotely controlled so that the steering position of the vehicle body V is in the support steering type and becomes the target steering position.

To explain the configuration of the boarding maneuver, information on the steering type selection switch 17 and detection information of the target steering position detection potentiometer _R0 that detects the operating position of the steering handle H, that is, the target steering position during the boarding maneuver. is input into the control device 11, and based on the information, the operation of the control valves 6, 7 of the steering hydraulic cylinders 4, 5 is controlled, so that the front and rear wheels 2, 3 are steered according to the specified steering type. In addition, the steering wheel H is configured to be able to be operated to a target steering position using the steering handle H. However, the shift position of the transmission device 8, that is, the vehicle speed, during boarding and maneuvering is adjusted by directly operating the shift arm 16 using the shift pedal 9.

In the figure, reference numeral 18 denotes a control mode switching switch for selectively selecting between the boarding control mode and the remote control mode using the transmitter 12.

Next, the configuration of the automatic stop control means A that automatically stops running of the vehicle body V when an abnormality occurs will be explained.

As shown in FIG. 1, a generator 19 driven by the output of the engine E, a regulator 20 that adjusts the generated output, a battery B charged by the electric power outputted via the regulator 20, A keystop solenoid 21a serving as an emergency stop actuator 21 that forcibly stops the engine E and brings the vehicle body V to an emergency stop by cutting off fuel supply to the engine E, a keystop relay 22 that operates the keystop solenoid 21a, and , this keystone relay 22
Relays 23 are provided to drive the . or,
Actuators such as the keystop solenoid 21, the keystop relay 22, and the control valves 6 and 7 are directly supplied with power from the battery B via the key switch 24 as a main switch, so that the control device 11 and the automatic stop A constant voltage regulator 25 is installed in each circuit of the control means A.
The device is configured to supply stabilized power via the power source.

When the key switch 24 is operated to the AC contact side and the work vehicle is in operation, the pressure of the hydraulic oil for operating the steering hydraulic cylinders 4, 5, etc. is normal, and the power generation If there is an abnormality in the output voltage Ve of machine 19,
The key stop solenoid 21 is operated to cut off the fuel supply to the engine E and perform an emergency stop.

The configuration of each part will be explained in detail below.

First, the configuration of the output voltage monitoring means W that monitors whether the output voltage Ve of the generator 19 is equal to or higher than the set voltage Verf will be explained.

That is, a charge lamp _L1 is connected via a fuse F between the L terminal of the regulator 20 and the AC contact of the key switch 24.
This charge lamp L ₁ is configured to turn off when the generator 19 is generating power normally, and turn on when the output of the generator 19 decreases, so that a decrease in the output of the generator can be visually confirmed. At the same time, the voltage at the connection point between the L terminal of the regulator 20 and the charge lamp _L1 , that is, the voltage at the connection point of the generator 1
The output voltage Ve of the generator 19 is compared with the set voltage Vref set based on the operating rated voltage of the key stop solenoid 21, and when the output voltage Ve of the generator 19 falls below the set voltage Vref, the output voltage becomes "L". Voltage abnormality signal changing from level to “H” level
A first comparator A ₁ is provided which outputs P ₁ .

Further, an oil pressure switch 26 for the engine E is provided, and one end of the oil pressure switch 26 is grounded, and the other end is connected to an oil pressure warning light.
said charge lamp _L1 and fuse F via _L2
It is connected to the connection point. A second comparator A ₂ determines whether the engine E is activated or stopped by determining whether the voltage at the connection point between the oil pressure switch 26 and the oil pressure warning light L ₂ is higher than the set voltage. It is provided. In other words,
If the oil pressure does not rise even after starting the engine E, the oil pressure switch 26 remains in the ON state, the oil pressure warning light L ₂ lights up, and the output of the second comparator A ₂ changes from the "L" level. It is configured to change to "H" level and output a hydraulic abnormality signal _P2 .

Also, the key switch 24 is in the starter position ST.
An inverter G ₁ is provided which outputs an emergency stop prohibition signal P ₃ that becomes “L” level when the voltage abnormality signal P ₁ and the oil pressure abnormality signal are operated.
P ₂ and the emergency stop prohibition signal P ₃ are provided with an AND gate G ₂ that calculates the AND of each of the signals P ₁ , P ₂ ,
When all _P3 are at "H" level, the output of this AND gate _G2 outputs the keystroke relay 2.
It is configured to operate a relay driver _G3 that drives a relay 23 for operating a relay 23.

[Another example]

Next, the configuration of another embodiment of the present invention will be described based on the circuit diagram shown in FIG.

In this embodiment, the output voltage monitoring means W
, instead of monitoring the output of the regulator 20, the constant voltage regulator 2
The emergency stop actuator 21 includes an engine stop motor that operates a fuel valve that cuts off the fuel supply to the engine E in place of the key stop solenoid 21a. 21b. However, in the drawings, the same numbers and symbols as shown in the circuit diagram of FIG. 1 have the same functions, and their explanations will be omitted.

That is, a motor starting relay 22a for operating the engine stop motor 21b having the same function as the keystroke relay 22 is provided, and a relay 23 for operating the keystroke relay 22 operates the motor driving relay 2.
2a, and maintains the relay 23 in the ON state for a predetermined time (set to about 5 seconds in this embodiment) required to completely stop the engine E. 27,
A one-shot multivibrator 28 is provided to start this timer 27, and the relay 23, timer 27, one-shot multivibrator 28, and emergency stop control means are provided even after the power supply from the constant voltage regulator 25 is stopped. A backup power source 2 that supplies power to maintain each part constituting A in an operating state for the predetermined period of time;
9 are connected in parallel to the constant voltage regulator 25.

Further, in configuring the output voltage monitoring means W, the output voltage of the battery B is controlled by the constant voltage regulator 25.
By utilizing the fact that when the output voltage of the constant voltage regulator 25 decreases below the voltage at which the output voltage maintenance function of the battery B stops, the output voltage Vr of the constant voltage regulator 25 decreases in conjunction with the decrease in the output voltage of the battery B.
A transistor _Q1 is provided which turns off when the voltage across the Zener diode Dz drops below the Zener voltage Vz. Then, when the output voltage Vr of the constant voltage regulator 25 drops below the Zener voltage Vz as the set voltage Vref, the collector voltage of the transistor _Q1 changes from the "L" level to the "H" level, causing a voltage abnormality signal P. ₁
The one-shot multivibrator 28 is triggered via the NOR gate _G4 . Note that the oil pressure abnormality signal P ₂ and the emergency stop prohibition signal P ₃ are input to the NOR gate G ₄ , and as in the embodiment shown in FIG.
Engine E is in operation and the power supply voltage is
Only if Ve drops below the set voltage Vref,
The engine stop motor 21b is configured to operate.

The motor drive relay 22a and the engine stop motor 21b are directly supplied with power from the battery B, and when the motor drive relay 22a stops operating after a predetermined period of time, that is, the engine stops. When E comes to an emergency stop, the power supply to the engine stop motor 21b is switched to the fuel supply in conjunction with the operation of the engine stop motor 21b so that the engine stop motor 21b automatically returns to the fuel supply side. A return relay 30 is provided for switching to the side.

In the figure, D is a diode for backflow prevention, and C is a diode for preventing backflow.
is a large capacity capacitor for configuring the backup power supply 29.

By the way, in the above embodiment, the engine E is forcibly stopped to perform an emergency stop. You can. Further, an alarm notification means such as an alarm lamp or a buzzer may be provided to perform an emergency stop and issue an alarm based on the detection of an abnormality.

Further, although the output voltage monitoring means W is configured to indirectly monitor the output voltage of the generator 19, the output voltage of the generator 19 itself may be directly monitored.

Further, as an abnormality detecting means other than the output voltage monitoring means W, in each of the above embodiments, only the case where a hydraulic abnormality detecting means is provided is illustrated, but for example, abnormality in the shift position of the transmission device 8, overheating of the engine E, etc. It is possible to provide means for detecting various types of abnormality information such as brake abnormality, vehicle body overturning, abnormality of installed working equipment, and emergency stop command during remote control.

In short, the present invention provides that when the output of the generator decreases, before the output voltage of the battery drops below the voltage at which the emergency stop actuator no longer operates.
This emergency stop actuator is actuated to stop the vehicle running, and the configurations of the generator output voltage monitoring means W and automatic stop control means A can be modified in various ways.

[Brief explanation of the drawing]

The drawings show an embodiment of the emergency stop device for a working vehicle according to the present invention, FIG. 1 is a circuit diagram showing the structure of the automatic stop control means, and FIG. 2 shows the schematic structure of the control system and the schematic structure of the transmission system. The block diagram, FIG. 3, is an overall side view of the working vehicle. FIG. 4 is a circuit diagram showing the configuration of another embodiment of the automatic stop control means. 19... Generator, 21... Emergency stop actuator, E... Engine, B... Battery, Ve
...Output voltage, Vref...Setting voltage, W...Output voltage monitoring means, A...Automatic stop control means.

Claims (1)

[Scope of utility model registration request] Emergency stop of a work vehicle equipped with a generator 19 driven by an engine E, a battery B charged by the generator 19, and an emergency stop actuator 21 operated by power supply from the battery B. The device includes an output voltage monitoring means W that monitors whether the output voltage Ve of the generator 19 is higher than the set voltage Vref, and an output voltage monitoring means W that monitors whether the output voltage Ve of the generator 19 is higher than the set voltage Vref, and a An emergency stop device for a working vehicle, which is provided with an automatic stop control means A that operates the emergency stop actuator 21 to automatically stop the vehicle body V when the output voltage Ve falls below the set voltage Vref.