JPH05112977A - Automatic controller of construction vehicle - Google Patents

Abstract

PURPOSE:To prevent a construction vehicle from transferring to the dead angle direction to increase safety, when a person enters a danger area in the dead angle against an operator of the construction vehicle. CONSTITUTION:When a laborer 4 enters danger zones A2, B2 within the working range of a power shovel 1, if an operator drives to his dead angle direction by mistake, a solenoid valve preventing from transferring is actuated to stop feeding pressure oil to both right and left driving motors rotating both right and left crawlers of the power shovel 1 in order to stop the transferring motion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic control device for controlling traveling of a construction work vehicle.

[0002]

2. Description of the Related Art At a construction site or the like, a construction machine such as a power shovel and a worker often work simultaneously in the same work area.

In such a case, if the operator of the construction machine and a worker working near the construction machine inadvertently enter the working range of the construction machine in operation, the person may come into contact with the construction machine. There is a possibility of causing a physical disaster.
Conventionally, as a means for preventing such a human disaster, an ultrasonic transceiver is attached to the front or rear of a construction work vehicle,
An ultrasonic wave is emitted from this ultrasonic wave transmitter / receiver in a predetermined direction, and the ultrasonic wave reflected from an operator or the like is received by the transmitter / receiver, so that an alarm is issued and the operator is in a dangerous state. I was trying to evoke.

However, in the conventional detection method as described above, since the ultrasonic wave reflected from the object in the alarm detection area is received by the transceiver to detect the presence of the object, the ultrasonic wave is reflected. If it is possible, it will detect all whether it is a worker or a stationary object, and it is difficult to determine whether the detected object is a worker or a stationary object. Therefore, there is a problem that it reacts with an object other than the worker, and if the operator stops the work vehicle due to this, the operating rate is reduced. Also, because the ultrasonic transceiver is provided only at one location on the front or rear of the work vehicle, it can be detected even if a worker enters the work area other than the detection area of the ultrasonic transceiver. There was a problem that I could not do it.

Therefore, the same questioner as the present invention can first simultaneously monitor all the warning detection areas of the construction work vehicle, and
We have applied for a work area monitoring device for construction vehicles that can reliably detect workers who have entered the detection area (Japanese Patent Application No. 2-1.
41166). The outline of the invention of this prior application is that a plurality of horn-type ultrasonic transmitters / receivers having a predetermined opening angle can be covered by a support member erected on a construction work vehicle with an alarm detection area having a predetermined radius centered on the construction work vehicle. As arranged diagonally downward in a ring shape, while generating ultrasonic waves of a predetermined frequency by applying a transmission signal to each of these horn-type ultrasonic transceivers, within the alarm detection area of the construction work vehicle The ultrasonic transmitter / receiver unit for an intruding object is carried by an intruding object which may possibly enter.

The ultrasonic transceiver unit for an intruding object has an ultrasonic receiver for receiving ultrasonic waves from a horn type ultrasonic transceiver, and has an alarm means and a horn type ultrasonic transceiver for operating at the time of ultrasonic wave reception. It has an ultrasonic wave transceiver that emits ultrasonic waves of a different frequency from the ultrasonic wave that it emits, and each horn-type ultrasonic wave transceiver when the ultrasonic signal from the ultrasonic wave transceiver on the intruding object side is received. The feature is that an intruding object is detected and monitored based on the signal. When each horn-type ultrasonic transceiver oscillates, ultrasonic waves from the opening surface of these horns are radiated in all directions of 360 degrees centering on the construction work vehicle, and the alarm detection area can be simultaneously monitored. Be in a position. As a result, even if an intruding object enters the alarm detection area from any direction, it can be detected reliably. Further, since ultrasonic waves having different frequencies are used for communication between the construction work vehicle and the intruding object, both detection and recognition are ensured.

[0007]

However, in the work area monitoring device for the construction work vehicle of the above-mentioned prior application, the warning detection area can be simultaneously monitored in all directions of 360 degrees centering on the construction work vehicle. Although it is possible to detect that an intruding object has entered the detection area and issue an alarm,
If the operator mistakenly runs the construction work vehicle in the blind spot direction of the operator during this alarm, the construction work vehicle detects the intruding object in the alarm detection area, but the construction work vehicle makes a blind spot. If the intruding object is a worker or the like traveling in the direction, there is a risk of human injury.

The present invention has been made in view of the above points, and when an intruding object enters a predetermined alarm detection area centering on a construction work vehicle, the operator mistakenly causes the operator to run in the blind spot direction of the operator. Even if an operation is performed, the construction work vehicle can be prevented from running, and the construction work vehicle can be prevented from coming into contact with an intruding object or the like to prevent a human disaster from occurring. An object is to provide an automatic control device.

[0009]

In order to solve the above problems, the present invention provides an automatic control device for controlling the running operation of a construction work vehicle which is equipped with a running motor operated by pressure oil and which runs by the operation of an operator. Which transmits at least an ultrasonic wave of a first frequency so as to cover an area around the construction work vehicle that is a blind spot of the operator and can cover an alarm detection area of a predetermined radius centered on the construction work vehicle. One ultrasonic transmitter / receiver and an ultrasonic wave of the first frequency transmitted from the first ultrasonic transmitter / receiver, which is carried by an intruding object that enters the alarm detection area. When operating the second ultrasonic transmitter / receiver that emits an ultrasonic wave of a second frequency different from the ultrasonic wave of the first frequency when receiving and the traveling operation lever for traveling the construction work vehicle, the pressure oil is traveled. Pressure oil supply means for supplying to the travel motor, travel pressure oil stopping means provided in the supply path of the pressure oil to the travel motor to stop the supply of the pressure oil to the travel motor, and the alarm detection area. The intruding object enters the inside, and the first ultrasonic transceiver receives the ultrasonic wave of the second frequency transmitted from the second ultrasonic transceiver carried by the intruding object, and When the operator operates the traveling operation lever so as to drive the construction work vehicle in the rear direction of the operator, the traveling pressure oil stopping means is arranged to stop the supply of the pressure oil to the traveling motor. A control circuit for controlling driving is provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view showing the overall configuration when an automatic control device for a construction work vehicle according to the present invention is applied to a power shovel. In FIG. 1, 1 is a crawler-type power shovel as a construction work vehicle, 2 is a driver's cab of the power shovel 1, and 3 is an ultrasonic wave of a first frequency for monitoring a work area of the power shovel 1. This is a first ultrasonic transmitter / receiver, and the first ultrasonic transmitter / receiver 3 is installed, for example, on the roof of the cab 2.

The first ultrasonic transmitter / receiver 3 is formed by arranging pyramid horn type ultrasonic transmitter / receivers having an opening angle of 30 degrees in a ring shape around the power shovel 1 in a circumferential direction. It is composed of. The opening surface of each horn-type ultrasonic transceiver is directed obliquely downward at a predetermined angle (for example, 13.5 degrees) with respect to the horizontal plane. A control unit is installed in the cab 2 of the power shovel 1. This control unit oscillates each ultrasonic transmitter / receiver, processes a signal received by each ultrasonic transmitter / receiver, and performs an alarm and stop control of the power shovel 1.

Numeral 4 is an alarm zone A1 of the power shovel 1.
An object to be detected that enters the inside of B1, for example, an operator (hereinafter,
This worker 4 receives the ultrasonic wave of the first frequency and the alarm means 5a as an alarm means such as an alarm buzzer, and the second frequency when the ultrasonic wave of the first frequency is received. Second ultrasonic transmitter / receiver 5b that oscillates the ultrasonic waves of
The user carries an ultrasonic transmitting / receiving unit 6 for an intruding object, which has a built-in. As a result, the worker 4 makes the power shovel 1
Of the power shovel 1 and the second ultrasonic transmitter / receiver 5b of the worker 4 are communicated with each other by ultrasonic waves 7 when they enter the alarm zones A1 and B1 of Be able to confirm the existence and give an alarm.

The control unit of the first ultrasonic transmitter-receiver 3 for the power shovel 1 drives each horn-type ultrasonic transmitter-receiver at the same time by the output of the oscillation circuit at a predetermined frequency (for example, 28 kHz). The ultrasonic wave signal of the second frequency from the worker 4 side received by the ultrasonic wave transmitter / receiver is detected by the detection circuit, the detection signal output from this detection circuit is processed by the processing circuit, and the inside of the power shovel 1 not shown. The drive control of the alarm device and the stop control circuit of the power shovel 1 are controlled. Further, in the ultrasonic wave transmitting / receiving unit 6 for intruding object, the ultrasonic wave of the first frequency emitted from the first ultrasonic wave transmitter / receiver 3 of the power shovel 1 is received by the second ultrasonic wave transmitter / receiver 5b and is detected by the detection circuit. The ultrasonic signal is detected, the detection signal output from the detection circuit is processed by the signal processing circuit to control the alarm means 5a to ring, and the second ultrasonic wave transmitter / receiver 5b outputs the second signal by the signal processing circuit. A command to oscillate an ultrasonic wave of a frequency, a signal of a predetermined frequency (for example, 21 kHz) is oscillated by a oscillating circuit for a predetermined time based on the oscillating command, and the second ultrasonic wave transceiver 5b is driven and controlled by the oscillating output. It is supposed to do. It should be noted that in the case of the present embodiment, the transmittable / receivable range of the first ultrasonic transceiver 3 on the power shovel 1 side and the ultrasonic transceiver unit 6 for an intruding object on the worker 4 side is a radius centered on the power shovel 1. The distance is around 10 meters.

On the other hand, the region where the power shovel 1 side detects an intruder is set relatively to the pointing direction of the arm 1a and the bucket 1b of the power shovel 1.
As shown in FIG. 3, a fan-shaped region of 130 degrees on the right side with respect to the directing direction of the arm 1a and the bucket 1b has a radius of 5 to 5.
The range of 10M is the alarm zone A1, the range of 0-5M is the danger zone A2, and the arm 1a and the bucket 1b are also included.
In the area of 270 degrees excluding the area of 30 degrees to the right front and 60 degrees to the left front with respect to the pointing direction of, the range of radius 3 to 5M is the warning zone B1, and the range of 0 to 3M is the danger zone B2. These zones A1, A2, B1 and B2 are set so as to cover the blind spot of the operator (not shown) of the power shovel 1, and move with the swing of the arm 1a and the bucket 1b of the power shovel 1 to move to the arm 1a. And the relative position of the bucket 1b with respect to the pointing direction is always constant, which allows the arm 1 to move even at the same point.
The location of the warning and danger zone changes depending on the turning of a and the bucket 1b.

When the worker 4 carrying the ultrasonic wave transmitting / receiving unit 6 enters the alarm zones A1 and B1, the alarm means 5a of the ultrasonic wave transmitting / receiving unit 6 sounds due to an operation described later, which is dangerous. When the worker 4 is notified and the worker 4 enters the danger zones A2 and B2, the operation of the power shovel 1 and the movement of the power shovel 1 and the arm 1a and the bucket 1b are performed by the operation described below.
When the turning of the power shovel 1 is automatically stopped and is stopped, the running and turning of the power shovel 1 will not be performed even if the operator performs the running operation or the turning operation of the power shovel 1. However, in the automatic control device of the present embodiment, the worker 4 operates in the danger zone A
2, even if the vehicle has entered the area B2, the operator can travel in the direction within the field of view. Therefore, the power shovel 1 is provided with a structure for detecting the turning positions of the arm 1a and the bucket 1b as described below.

FIG. 2 is an explanatory view for detecting the turning position of the power shovel 1. In FIG. 2, reference numeral 1 c is a turning mechanism frame of the power shovel 1. On the traveling mechanism 1d,
A fixed portion 1e is arranged, and 90-degree arc-shaped proximity switch detection fittings 1f and 1g are attached to the fixed portion 1e. As shown in FIG. 3, the proximity switch detection fittings 1f and 1g are arranged in an arc shape (the angle with respect to the center is approximately 90 degrees) by changing the position and the height by 180 degrees with respect to the center of the fixed portion 1. I am setting it up. Further, as shown in FIG. 2, a contact mounting portion 1h is hung from the lower surface of the revolving unit 1c so as to face the outer peripheral surface of the fixed portion 1e, and a pair of proximity switches 1i, 1j are attached to the contact mounting portion 1h. Is attached. Contact mounting portion 1h and proximity switches 1i, 1j
Turns in unison with the revolving unit 1c, and the proximity switches 1i and 1j face the proximity switch detection fittings 1f and 1g or move away from the proximity switch detection fittings 1f and 1g depending on the turning position. There is.

In the power shovel 1 of this embodiment, when any one of the proximity switch detection fittings 1f and 1g faces the proximity switches 1i and 1j, 0 in FIG.
Crawlers CL and CR oriented in 180 ° and 180 ° directions
Of the power shovel 1, that is, the proximity switch 1i faces the proximity switch detection fitting 1f by the turning of the revolving structure 1c.
When the turning operation of the arm 1a and the bucket 1b is in a direction within the range of the area C1 in FIG. 3, if the operator performs a traveling operation, the operator's field of view is 0 degree in FIG. It is possible to travel in the direction of 180 degrees in FIG. 3, which is a blind spot for the operator. Similarly, when the proximity switch 1j faces the proximity switch detection fitting 1g and the turning positions of the arm 1a and the bucket 1b are in the direction of the area C2 in FIG. 3, the operator performs the traveling operation. In such a case, the operator can travel in the direction of 180 degrees in FIG. 3 which is within the field of view of the operator, and cannot travel in the direction of 0 degree in FIG. 3 which is the blind spot of the operator.

FIG. 4 is a circuit diagram of a control circuit for performing forward / backward prohibition control of the power shovel 1 in accordance with the operation of the proximity switches 1i, 1j, that is, a sequence control circuit for controlling the traveling of the power shovel 1. is there. 4, the same parts as those in FIG. 2 are designated by the same reference numerals. In FIG. 4, a positive potential is applied to L1,
2 is a power supply line to which a negative potential is applied, and for example, a voltage 24V of a battery mounted on the power shovel 1 is applied between the power supply lines L1 and L2. A proximity contact 1i is provided between the power supply lines L1 and L2.
1, a safety contact S1, a reverse contact Ra, and a series circuit of a relay R1 are connected. The proximity contact 1i1 is a normally-open contact that operates when the proximity switch 1i faces the proximity switch detection fitting 1f, and the reverse contact Ra and the reverse contact Rb described later are turned on when the travel operation lever is operated to the reverse side. Is the contact point. Further, the safety contacts S1 to S3 are the ultrasonic waves 7 at the second frequency transmitted by the first ultrasonic transmitter / receiver 3 from the second ultrasonic transmitter / receiver 5b when the worker 4 enters the danger zones A2 and B2. Is a contact which is turned on at the same time as a contact R10 of FIG. 5 which will be described later due to the urging of a relay (not shown).

On the other hand, between the power lines L1 and L2, the proximity contact 1j1, the safety contact S2, the forward contact Fa, and the relay R2.
Connected in series circuit. The contact point 1j1 is a contact point that is turned on when the proximity switch 1j faces the proximity switch detection fitting 1g, and the forward contact point Fa and a forward contact point Fb described later are contact points that are turned on when the traveling lever is operated to the forward side. Is. Further, between the power supply lines L1 and L2, the proximity contact 1i2, the proximity contact 1j2, and the safety contact S
3 and a parallel circuit of forward contact Fb and reverse contact Rb,
A series circuit with the relay R3 is connected. Proximity contact 1
i2, 1j2 are normally closed contacts that operate when the proximity switches 1i, 1j do not face the proximity switch detection fitting 1f, and the relays R1 to R3 have normally open contacts R1a, R2a, R3a, respectively. And these contact points R
1a to R3a form a parallel circuit, and the parallel circuit and the stop valve V are connected in series between the power supply lines L1 and L2.

Next, the turning control mechanism will be described. FIG. 5 is a hydraulic circuit diagram of the turning control mechanism. The contact point R10 in FIG. 5 is such that the first ultrasonic transmitter / receiver 3 receives the ultrasonic wave of the second frequency and the first ultrasonic transmitter / receiver 3 This is a contact that closes when the relay is activated by the alarm output output by the control unit. Further, reference numeral 10 in FIG. 5 denotes a turning operation lever, which is operated by the operator when turning left and right in the cab of the power shovel 1. By turning the turning operation lever 10 to the left, the turning direction switching valve 12 is urged via the left turning braking electromagnetic valve 8L to form a circuit of the left turning operation valve 12L. The left turning operation valve 12L is opened at a valve opening degree according to the amount, and the turning hydraulic pump 14 turns the turning motor 13
Power oil is supplied to the oil tank 14a through a path for rotating the turning motor 13 in the left turning direction, and further circulates to the oil tank 14a.

Similarly, when the turning operation lever 10 is turned to the right, the turning direction switching valve 12 is energized via the electromagnetic valve 8R for braking the right turn, and the circuit of the right turning operation valve 12R is opened. The right turning operation valve 12R is formed, and the right turning operation valve 12R is opened at a valve opening degree according to the operation amount of the turning operation lever 10 to rotate the turning motor 13 from the turning hydraulic pump 14 to the turning motor 13 in the right turning direction. Power oil is supplied through a route that
Furthermore, it circulates to the oil tank 14a. The left turning braking solenoid valve 8L and the right turning braking operation solenoid valve 8R are urged from the state shown in FIG. 5 when the contact R10 is closed to allow the pilot oil to flow to the tank port 15. ing. In this case, the turning direction switching valve 12 is deenergized to form the center position circuit 12c, which cuts off the supply of the power oil from the turning hydraulic pump 14 to the turning motor 13 and causes the power shovel 1 to move. It has become impossible to turn. At this time, the power oil returns to the tank port 14a.

Next, the structure of the traveling control mechanism will be described. FIG. 6 is a hydraulic circuit diagram of the traveling braking mechanism. Of the circuits in FIG. 6, only the hydraulic pump and the valve for switching the hydraulic pressure supply direction are shown for the left crawler CL shown in FIG. Illustration of those relating to CR is omitted. The hydraulic pump for the right crawler CR and the valve for switching the hydraulic pressure supply direction are shown in FIG.
A circuit similar to the circuit for the left crawler CL shown therein is separately provided. By the way, 9L in FIG. 6 is a traveling braking electromagnetic valve for the left crawler CL which is energized from the state of FIG. 6 by energizing the stop valve V of FIG. 4, and 16L is a traveling direction switching for the left crawler CL. The valves, 18L, 18R are traveling motors for rotating the left and right crawlers CL, CR shown in FIG. 3, respectively. Then, in accordance with the operation of the traveling operation lever (not shown) by the operator, the traveling direction switching valve 16L moves from the state in which the neutral circuit 16N is formed to either the forward operation valve 16F or the reverse operation valve 16R. When energized, this causes the power oil from the traveling pump 16a to pass through the traveling braking electromagnetic valve 9L, the center swivel joint 17, the left traveling motor 18L,
The left traveling motor 18L circulates in the path of the center swivel joint 17 and the tank port 19 and rotates in either the forward or backward direction.

When any of the contacts R1a to R3a shown in FIG. 4 is closed and the stop valve V is energized, the traveling braking electromagnetic valve 9L is energized from the state shown in FIG.
The power oil from the traveling pump 16a is used as the traveling direction switching valve 16
The power is supplied to the tank port 19 without being supplied to L, and the supply of power oil to the left travel motor 18L is cut off, so that the power shovel 1 cannot travel. still,
As described above, the power shovel 1 of the present embodiment is provided with the hydraulic pump for the right crawler CR and the valve for switching the hydraulic pressure supply direction separately as in the circuit for the left crawler CL shown in FIG. With respect to these right side circuits, the same operation as that of the above left side circuit is performed in response to the operation of the traveling operation lever (not shown) by the operator.

Next, the operation of the present embodiment configured as described above will be described. When the power of the shovel 1 is stopped, the first ultrasonic transceiver 3 is activated, and when each horn-type ultrasonic transceiver is activated, a predetermined frequency (28 KHz, first frequency (Corresponding) ultrasonic waves are radiated obliquely downward over the entire 360 degrees from the opening surface of each horn. In such a state, when the worker 4 carrying the ultrasonic transmission / reception unit 6 enters the alarm zones A1 and B1, the first ultrasonic transmission / reception unit 3 receives a signal from one of the horn-type ultrasonic transmission / reception units. Since the ultrasonic wave of one frequency is received, the ultrasonic wave is converted into an electric signal. Then, receiving the converted signal, only the ultrasonic signal of the first frequency oscillated from the first ultrasonic transmitter / receiver 3 is extracted and output to the signal processing circuit.

The signal processing circuit knows that the worker 4 himself has entered the work area of the power shovel 1 by sounding an alarm buzzer based on the detection signal from the detection circuit.
By this, the worker 4 knows the danger by himself, and the warning zone A
1, Evacuate outside B1. On the other hand, when the worker 4 does not notice the alarm buzzer and enters the danger zones A2 and B2 from the alarm zones A1 and B1, the worker 4 itself receives the warning by the alarm buzzer and at the same time, the ultrasonic transmission / reception unit 6
The internal signal processing circuit gives a start command to the oscillation circuit, and the ultrasonic transmitter / receiver is driven by the oscillation output, and the ultrasonic wave (frequency 21 KHz) 7 at the second frequency is transmitted to the first ultrasonic transmitter / receiver 3 of the power shovel 1. Is radiated toward.

When this ultrasonic wave 7 is received by any of the horn type ultrasonic wave transceivers on the side of the power shovel 1, this ultrasonic wave is converted into an electric signal, and only the ultrasonic wave signal received by the detection circuit is received. The signal is extracted and a drive signal is output from the signal processing circuit to the alarm device to drive the alarm device and at the same time notify the operator of the power shovel 1 that the worker 4 or the like has entered the danger zones A2, B2. At the same time, the first
A signal is output from the ultrasonic wave transmitting / receiving unit to activate the relay, the contact R10 in FIG. 5 is closed, and the left and right swing braking solenoid valves 8L and 8R are simultaneously energized to rotate the swing direction switching valve 12 Is released, the supply of power oil from the swing hydraulic pump 14 to the swing motor 13 is cut off, and the power shovel 1 cannot swing. Therefore,
When starting the turning operation from the turning stopped state, the worker 4
It is possible to prevent the occurrence of troubles caused by contact with the like.

After the turning operation is started in a state where the worker 4 or the like has not entered the danger zones A2 and B2,
Even when the worker 4 or the like enters the danger zones A2 and B2 during the turning operation, the hydraulic circuit of FIG. 5 forms a path similar to the above and the rotation of the turning motor 13 is stopped at that time. The turning operation will be stopped midway. Therefore, even during the turning motion, it is possible to prevent the occurrence of obstacles due to contact with the worker 4 or the like.

Next, automatic stop of the traveling operation of the power shovel 1 will be described. In the power shovel 1 shown in FIG. 1, the direction opposite to the directing direction of the arm 1a and the bucket 1b is a blind spot of the operator, and the operator cannot directly visually recognize the approach of the worker 4 or the like. for that reason,
When the power shovel 1 travels toward the back of the operator, the travel of the power shovel 1 is automatically controlled based on the presence or absence of the worker 4 or the like in the danger zones A2 and B2. On the other hand, when the worker 4 or the like enters the direction in which the arm 1a and the bucket 1b are oriented, that is, the operator's field of view, if the operator determines that there is a risk, the power shovel is used. The operation rate is higher when the operation of 1 is stopped manually. Therefore, when the traveling operation of the power shovel 1 in the front direction of the operator is performed, the power shovel 1 travels according to the operation of the operator.

For example, when the arm 1a and the bucket 1b of the power shovel 1 are directed in a direction within the range of the area C2 in FIG. 3 as the revolving structure 1c revolves, the proximity switch 1j causes the proximity switch detection fitting 1g. , The proximity contact 1j1 is closed and the proximity contact 1j2 is released.
In this state, the worker 4 sets the danger zone A2, which is set in a direction other than the directing direction of the arm 1a and the bucket 1b.
When it enters into B2, the alarm device in the first ultrasonic transmitter / receiver 3 is activated and the safety contacts S1 to S3 are closed. Here, the operator is mistakenly in front of the operator, 1 in FIG.
With the intention of running the power shovel 1 in the direction of 80 degrees,
When the forward operation lever is operated, at the same time, the forward contact Fa is closed. Therefore, the power lines L1 and L2
In the meantime, the proximity contact 1j1 to the safety contact S2 to the forward contact Fa
A closed circuit of the relay R2 is formed, the relay R2 is energized, its normally open contact R2a is closed, and the stop valve V2 is closed.
Is activated.

As a result, the traveling braking solenoid valve 9L shown in FIG.
The driving oil from the traveling oil pump 16a flows into the tank port 19 and is not supplied to the left and right traveling motors 18L and 18R. Therefore, the left and right crawlers CL,
The rotating operation of the CR becomes impossible and the traveling of the power shovel 1 becomes impossible. The power shovel 1 does not move forward (travel in the 0 degree direction in FIG. 3) and the workers 4 in the danger zones A2 and B2. The safety of can be secured. It should be noted that this operation is not limited to when the running of the power shovel 1 being stopped is started, and during the running of the power shovel 1, the worker 4 enters the danger zones A2 and B2 whose positions change due to the running. If it does, the same is done.

Further, the arm 1a and the bucket 1b of the power shovel 1 are oriented in a direction within the area C1 in FIG. 3, and the worker 4 is in the danger zone A2, which is set in the rear direction of the operator. When the operator mistakenly moves the power shovel 1 in the 0 degree direction in FIG. 3, which is in front of the operator when he / she enters the inside of B2, and operates the reverse operation lever, the proximity switch 1i detects the proximity switch. It faces the metal fitting 1f, the proximity contact 1i1 is closed, and the safety contacts S1 to S3 are closed,
Since the reverse contact Ra is closed, the power supply lines L1 and L2 are closed.
In the meantime, the proximity contact 1i1 to the safety contact S1 to the reverse contact Ra
The closed circuit of the relay R1 is formed, the relay R1 is energized, and the normally open contact R1a of the relay R1 is closed to stop the stop valve V1.
Is activated. Therefore, as in the above, the left and right crawlers C
Power shovel 1
Of the danger zone A2, because the power shovel 1 does not move backward (runs in the direction of 180 degrees in FIG. 3).
It is possible to ensure the safety of the worker 4 in B2.

Next, the case where the arm 1a and the bucket 1b of the power shovel 1 are oriented in the directions of the areas C3 and C4 in FIG. 3 will be described. In this case, the proximity switches 1i and 1j are both the proximity switch detection fittings 1.
Do not face f and 1g. Therefore, the proximity contacts 1i1,
Both 1j1 are off, and the proximity contacts 1i2, 1j2 are both on. Here, when the worker 4 enters the danger zones A2 and B2 set in the rear direction of the operator and the safety contacts S1 to S3 are turned on, and the operator operates the forward operation lever or the reverse operation lever in this state. The forward contact Fb or the reverse contact Rb is closed, and the relay R3 is energized. Therefore, the relay R3 is closed, the normally open contact R3a is closed, and the stop valve V3 is closed.
Is activated. Therefore, as in the above, the left and right crawlers C
Power shovel 1
3 becomes impossible and the power shovel 1 cannot perform forward and backward movements, that is, the arm 1a and the bucket 1b of the power shovel 1 are directed in the directions of areas C3 and C4 in FIG. In this case, it is impossible for the power shovel 1 to travel in the directions of 0 degree and 180 degrees in FIG.

As described above, in this embodiment, the first ultrasonic transmitter / receiver 3 is installed in the power shovel 1 to monitor all the blind spots of the operator of the power shovel 1, and the worker 4 Etc. intrude into the working range of the power shovel 1, it is surely detected, and when the worker 4 etc. intrudes into a particularly dangerous area, the operator turns and runs the power shovel 1. Even if an operation is performed, the turning and traveling operations can be automatically stopped. Further, between the power shovel 1 and the worker 4, the ultrasonic waves having different frequencies are used to recognize each other's existence and issue an alarm, so that the worker etc. who inadvertently intrudes can be surely secured. In addition to being able to detect and identify, it is possible to solve the problem that the power shovel 1 stops due to a stationary object such as a utility pole or a fence as in the conventional case.

In the above embodiment, the case where the work area of the power shovel is monitored has been described, but it goes without saying that it can also be used for construction work vehicles such as bulltozers, roller cars and backhoes, and the alarm zones A1, B1
Area setting between the dangerous zones A2 and B2 is arbitrary. Further, in the above embodiment, the case where the presence of each other is recognized by the alarm buzzer has been described, but a rotating lamp or other means may be used.

Further, when the worker 4 is invading the alarm zones A1 and B1 due to the difference in the zone in which the worker 4 is invading, the buzzer between the power shovel 1 side and the worker 4 side is set at a predetermined interval. When the worker 4 enters the danger zones A2 and B2 by making an intermittent sound,
The buzzer on the side of the power shovel 1 and the side of the operator 4 may be made to sound with an intermittent sound at an interval shorter than the predetermined interval. By doing so, the operating rate of the power shovel 1 and the stability of the worker 4 can be further improved. Further, in the present embodiment, when the worker 4 enters the danger zones A2 and B2, the driving of the swing motor is stopped by cutting off the supply of the pilot pressure oil. However, similar to the case of the traveling motor, The supply of the pressure oil necessary for driving the swing motor instead of the pilot pressure oil may be directly stopped.

It should be apparent from the description of the above embodiment that the turning and traveling operation stop according to the present invention can be applied to both cases where the power shovel 1 is in operation stop or in operation.

[0037]

As is apparent from the above description, according to the present invention, the construction work vehicle is provided with the ultrasonic transmission / reception unit so that the alarm detection area having a predetermined radius in the direction of 360 degrees around the center can be covered. In addition, when an intruding object enters the blind spot of the operator in the alarm detection predetermined danger area, even if the operator performs the operation of retracting the construction work vehicle toward the back of the operator, the operation is surely performed automatically. The progress of the work vehicle can be stopped, and the intruding object will not be dangerous.

[Brief description of drawings]

FIG. 1 is a plan view showing an overall configuration showing an embodiment of the present invention.

FIG. 2 is a structural explanatory view of a revolving structure of the power shovel and a traveling mechanism frame in the present invention.

FIG. 3 is an explanatory diagram of a traveling prohibited state of the power shovel according to the present invention.

FIG. 4 is a sequence control circuit diagram of traveling braking of the power shovel in the present invention.

FIG. 5 is a hydraulic circuit diagram of the swing braking mechanism in the present invention.

FIG. 6 is a hydraulic circuit diagram of the traveling braking mechanism according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 power shovel 1c revolving structure 3 first ultrasonic transmitter / receiver 4 worker 5a alarm means 5b second ultrasonic transmitter / receiver 6 ultrasonic transmitter / receiver unit 7 ultrasonic wave 9L traveling braking solenoid valve 10 direction control lever 12 turning direction switching valve 13 Swing motor 16L Travel direction switching valve 18L Left travel motor 18R Right travel motor

Claims (1)

[Claims] 1. An automatic control device for controlling the traveling operation of a construction work vehicle equipped with a traveling motor operated by pressure oil and operated by an operator, the construction work vehicle being a blind spot of at least the operator. The first ultrasonic transmitter / receiver that transmits the ultrasonic wave of the first frequency so as to cover the alarm detection area of a predetermined radius centering on the construction work vehicle including the peripheral area of A second frequency different from the first frequency ultrasonic wave when receiving the first frequency ultrasonic wave transmitted from the first ultrasonic transmitter / receiver and carried by the intruding object. A second ultrasonic transmitter / receiver that emits ultrasonic waves, a traveling pressure oil supply unit that supplies the pressure oil to a traveling motor when the traveling operation lever for traveling the construction work vehicle is operated, and the traveling motor. Is provided in the pressure oil supply passage to stop the supply of the pressure oil to the traveling motor, and the intruding object enters the alarm detection area. The first ultrasonic transmitter / receiver receives ultrasonic waves of a second frequency transmitted from the second ultrasonic transmitter / receiver to be carried, and the operator runs the construction work vehicle toward the back of the operator. And a control circuit for driving and controlling the traveling pressure oil stopping means so as to stop the supply of the pressure oil to the traveling motor when the traveling operation lever is operated. Automatic control device for construction vehicles.