JPH0224758B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an overturn prevention mechanism for an aerial work vehicle, and in particular, the present invention relates to an overturn prevention mechanism for an aerial work vehicle, and in particular, an overturn prevention mechanism that predicts the danger angle of a boom overturn and automatically corrects balance correction. Regarding the overturn prevention mechanism for work vehicles.

[Conventional technology]

This type of aerial work vehicle has a boom that is pivotally supported vertically on a swivel platform that is installed on the vehicle body so that it can be rotated left and right, and a bucket is pivoted to the tip of this boom. There are some types of bucket lifts (so-called boom-type lifts) that allow workers to swivel, rise and fall, or expand and contract toward telephone poles or walls while carrying a worker on them, allowing work to be carried out at high places without scaffolding. By the way, the length of the entire boom of such an aerial work vehicle is, for example, 8 to 15 meters. For this reason, if the boom is extended for a long time, its center of gravity may shift and cause it to tip over.In order to prevent accidents from tipping over, conventional methods use mechanical means to detect the length and angle of the boom, and when the boom reaches a dangerous range, it The boom was controlled so that it could not be extended further or tilted downward.

[Problem that the invention seeks to solve]

According to such conventional aerial work vehicles, the safe working range is small, so there is a problem that the working range is limited.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an overturn prevention mechanism for a high-altitude work vehicle that reduces the danger angle of the boom overturning and enlarges the working range.

[Means to solve problems]

The present invention, which solves the above-mentioned problems, provides an aerial work vehicle in which a boom is pivotably supported on a swivel base that is rotatably provided on the vehicle body, and a bucket is pivotally attached to the tip of the boom. Overhanging bodies that can expand and contract horizontally are provided on both sides of the vehicle body, and outriggers that lift the vehicle body are provided at the ends of these overhanging bodies, and the raised vehicle body can be moved in the length direction of the overhanging bodies. A hydraulic actuation mechanism is provided, and the boom is equipped with a length sensor that can measure its extension and contraction length, and an angle sensor that can detect the angle of the boom from the horizontal, and a position on the overhang body that detects the distance from the outrigger to the vehicle body. A sensor is provided, the detection signals from the length measurement sensor and the angle sensor are taken in, and this is compared with preset fall danger range data,
When it is determined that the vehicle is in the overturning danger range, the position sensor determines the position of the vehicle body and drives and controls the above-mentioned hydraulic actuating mechanism to move the vehicle body in the opposite direction to the overturning danger direction along the length of the overhanging body. It is equipped with a hydraulic control device that allows it to be moved.

[Effect]

First, the lifting mechanism is set in a predetermined position and the vehicle body is fixed. Next, the boom is extended or the like, and at this time detection signals from the length measurement sensor and the angle sensor are taken into the hydraulic control device. The hydraulic control device matches the detection signal with the data of the danger range, and when the danger range is reached, controls the overhanging body to horizontally move the car body in the direction opposite to the dangerous direction. This allows the center of gravity to be moved to the opposite side of the boom to maintain balance and prevent overturning.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a perspective view showing a vehicle for aerial work equipped with an overturn prevention mechanism according to the present invention, and FIG. 2 is a side view of the vehicle for aerial work in FIG. 1.

In these figures, a swivel base 3 is rotatably provided on the body 2 of an aerial work vehicle 1, a boom 4 is pivotably mounted on the upper end of the swivel base 3, and a bucket 5 is attached to the tip of the boom 4. The boom 4 is configured to be telescopic in multiple stages, and its length is made variable by a telescopic cylinder (not shown), and the bucket 5 is always kept in a horizontal state by a balancing cylinder (not shown). It's under control. A depression angle cylinder 6 for controlling the depression angle is disposed between the boom 4 and the swivel base 3. The vehicle body 2 is provided with a lifting mechanism 9 on both the left and right sides of the front and rear thereof, which is composed of a projecting body 7 arranged vertically and an outrigger 8 provided at the tip of the projecting body 7 .

Furthermore, a length measuring sensor 10 is attached to the boom 4 to measure the length of expansion and contraction and output it as an electrical signal. The length measuring sensor 10 is of a tape measure type, and its main body 11 is installed at the base of the boom 4.
One end of the length measuring band 12 that goes in and out of the boom 4 is fixed to the tip fixing point 13 of the boom 4, and the length measuring band 12 converts the length pulled out from the main body 11 into an electrical signal. It is configured to output. The swivel base 3 is provided with an angle sensor 14 that measures the angle of the boom 4 and outputs it as an electrical signal.

Although not shown, there is a length measurement sensor 17 on the front or rear overhang body 7 for measuring the length of the expansion and contraction.
R, 17L are provided.

FIG. 3 shows a hydraulic control system including a fall prevention mechanism, and the hydraulic control device 15 receives signals for operation commands from the operation panel 16, and also receives signals for the length measurement sensor 10, angle sensor 14, and overhang body 7. The signals from the length measurement sensors 17R and 17L are taken in, and the pressure oil from the hydraulic pump 19 driven by the drive device 18 is controlled based on commands from the operation panel 16 or these command signals etc. 2
0,21,22R,22L,23R,23L,2
4 and the hydraulic motor 25 that drives the swivel table 3, respectively. The hydraulic control device 15 houses a ROM 26 that stores a safety area (the area indicated by the chain lines of x, y, and z) as shown in FIG.
The calculation results are stored in ROM based on the signals from 0 and 14.
26, and when it is determined that the safety range (x, y, z) is exceeded, the cylinders 22 and 23 for the overhang body 7 are driven and controlled to move the vehicle body 2 in the opposite direction to the direction in which the center of gravity has moved. It is designed to let you do so.

FIG. 5 shows the overturn prevention mechanism of the hydraulic control system.

The hydraulic control device 15 includes a hydraulic circuit 29 and a control device 30 that controls the hydraulic circuit 29.

The control device 30 includes a processing device (CPU) 31 that executes various calculations and processes, a read-only memory (ROM) 32 that stores programs that cause the CPU 31 to execute processes, etc. by predetermined means, and a read-only memory (ROM) 32 that stores various data. A memory (RAM) 33 for storing information such as
A digital input/output circuit (DIO) 34 that receives various commands from the operation panel 16 and provides necessary display signals to the operation panel 16, and various sensors 10, 14,
An input circuit (I) 35 that takes in detection signals from 17R and 17L, and a digital output circuit (DO) 36 that outputs a signal that controls the hydraulic circuit 29.
It is composed of a bus 37 that connects these. Note that the ROM 26 is connected to a bus 37.

The hydraulic circuit 29 supplies pressure oil pressurized by the hydraulic pump 19 to electromagnetic switching valves 41, 42, 43, and 4.
A pipe 40 is connected so that it can be supplied to
A pipe 46 is provided to guide oil from the electromagnetic switching valves 41, 42, 43, and 44 to an oil tank 45. The output side of the switching valve 42 and the depression angle cylinder 6 are connected by piping 49, 50, and the output side of the electromagnetic switching valve 43 is connected to the series-connected cylinders 22R, 23R for the right side overhang body 7 via piping 51, 52. and connect the solenoid switching valve 44.
The output side of the cylinder 22L for the left side extension body 7,
23L connected in series and connected via pipes 53 and 54. Each of the electromagnetic switching valves 41 to 44 is configured to be switched by a switching command from the CPU 31 outputted via the DO 36 of the control device 30, and the hydraulic fluid according to the command is transferred to each of the electromagnetic switching valves 41 to 44. It is designed so that it can be output to the output side of 44.

Next, the operation of the above embodiment will be explained.

First, the overhanging body 7 is extended to a predetermined length. This is done by operating the operation panel 16 to generate an operation command (step S100), and receiving this command, the hydraulic control device 15 controls the cylinder 22 for the overhang body 7.
Hydraulic oil is supplied to R, 22L, 23R, and 23L to extend each extending body 7 (step S101). When the hydraulic control device 15 detects that each overhanging body 7 has been extended to a predetermined length based on the detection signals from the respective length measurement sensors 17R and 17L (step S10)
2), cylinders 22R, 22L, 23R, 23L
Stop the supply of hydraulic oil to (step S10
3) It is realized by

Next, the outriggers 8 are extended to raise the vehicle body 2 above the ground. This is achieved by operating the operation panel 16 to generate an operation command (step S104), and having the hydraulic control device 15 that receives this command supply a predetermined amount of hydraulic oil to the outrigger cylinder 24 (step S105). .

FIG. 7 shows a state in which the overhanging body 7 is extended by a predetermined length and the outriggers 8 are extended to float the vehicle body 2 in this manner.

This allows rotation of the swivel base 3, extension and contraction of the boom 4,
It becomes possible to control the depression angle of the boom 4.

In step S107, a command to extend and retract the boom 4, in step S108, a command to control the depression angle of the boom 4, and in step S109, a command to control the rotation of the swivel base 3 can be individually generated.

When an extension/retraction command for the boom 4 is issued in step S107, this is taken into the CPU 31 via the DIO 34, the command is judged, and the electromagnetic switching valve 41 is actuated and controlled via the DO 36, and the extension/retraction cylinder 2 is
The boom 4 is extended or retracted by supplying hydraulic oil to the boom 4 (step S110).
Next, the detection signal (l) from the length measurement sensor 10
and the detection signal (θ) from the angle sensor 14 are read through the input circuit 35, and this signal is sent to the RAM.
33 (step S111). Next, using the data l and θ stored in the RAM 33, the CPU 31 calculates the following equations (1) and (2) (step S112).

H=lsinθ...(1) V=lcosθ...(2) However, H: Horizontal length of boom 4, V: Vertical length of boom 4, l: Length of boom 4, θ: Boom 4 and the angle of the horizontal plane.Furthermore, in step S113, the safe area (x, y, z) of FIG. 4 stored in the ROM 26
Then, the CPU 31 compares the above calculation results and determines whether or not it is in the safe area (step S114).
If it is determined in step S114 that the loop is in the safe area (YES), the process moves to step S119, where the F register is checked to determine whether it was an abnormal processing loop last time, and if there is no abnormality, the process proceeds to step S115. Move.

In step S115, it is determined whether the boom 4 is to be controlled for length or angle, and if it is to be controlled for the length of the boom 4, the process moves to step S116, where it is determined whether the desired length has been reached. When it is determined in step S116 that the desired length has been reached, the process proceeds to step S11.
7, operate the operation panel 16 to issue a stop command for boom length control. Then, the CPU 31 obtained through the DIO 34 moves the electromagnetic switching valve 41 to the stop position through the DO 36 and stops it (step S11).
8). Note that if the desired length is not found in step S116, the process returns to step S107.

When the boom 4 angle control command is issued in step S108, this command is sent to the CPU 3 via the DIO 34.
1, determines the command, controls the electromagnetic switching valve 42 via the DO 36, supplies hydraulic oil to the depression cylinder 6, and lifts the boom 4 (step S120). Next, steps S111~
When the process passes through S114 and is in the safe area (x, y, z) shown in FIG.
Move on to 15. Since it is determined in step S115 that angle control is required, it is determined in step S121 whether the desired angle has been achieved. When it is determined in step S121 that the desired angle is reached, step S1
At step 22, the operation panel 16 is operated to issue a stop command to control the angle of the boom 4. Then, the CPU 31, which obtained this information via the DIO 34, switches the electromagnetic switching valve 42 to the DO 36.
The angle control of the boom 4 is stopped (step S123). In addition, step S
If the angle is not the desired angle in step S121, step S1
Return to 08.

On the other hand, in step S114, the safe area (x, y,
z), the process moves to step S124, where it is determined whether the F register is set to "left" or "right"; if it is not set, the process moves to step S125, where the movement of the boom 4 is In order to stop the CPU 31, the solenoid switching valve 4 is
1 and 42 to the stop position. Next, in step S126, the CPU 31 determines the data regarding the direction of the boom 4 stored in the RAM 33, and if it is "right", the process moves to step S127, and if it is "left", the process moves to step S128. Step S12
7, the CPU 31 is the cylinder 2 for the overhang body 7.
The electromagnetic switching valves 43 and 44 are driven and controlled so that the cylinders 2L and 23L are retracted and the cylinders 22R and 23R for the extension body 7 are expanded. Further, in step S128, the CPU 31 drives and controls the electromagnetic switching valves 43 and 44 so as to extend the cylinders 22L and 23L for the overhang body 7 and retract the cylinders 22R and 23R for the overhang body 7. After completing steps S127 and 128, step S
The process moves to step S129, where it is determined whether the overhanging body 7 has moved a predetermined length, and if it has not moved, the process proceeds to step S1.
Returning to step S130, if the object has moved, the process moves to step S130. For example, steps S126, S128, S1
When each step of 29 is completed, the state will move from the state shown in FIG. 7 to the state shown in FIG. 8 if attention is paid only to the relationship between the vehicle body 2 and the overhanging body 7.

In step S130, movement of the boom 4 which was stopped in step S125 is permitted, and then in step S137, whether the boom 4 has been moved to the left or right is set in the F register. Then, the detection signals (l, θ) from the sensors 10 and 14 are stored in the RAM 33 via the input circuit 35 (step S
131), then data from RAM33 (l,
Calculate equations (1) and (2) above based on θ). (Step S132).

In addition, the ROM 26 has a safety area (x, y,
z) is stored, and the above calculation result is compared with this safe area (step S133), and it is determined in step S134 whether or not it is safe. If it is safe, the process moves to step S115, but if it is outside the area, it is determined to be dangerous. If so, an alarm is issued from the operation panel 16 in step S135, and at the same time, the operation of the boom 4 is stopped (step S136). In other words, CPU31 is
An alarm is generated by applying an alarm signal to the operation panel 16 via the DIO 34, and the electromagnetic switching valves 41 and 42 are driven and controlled to the stop position via the DO 36. Furthermore, if it is determined in step S119 that it is a rightward movement, the overhang body 7 is returned to its original position in step S138, the F register is reset, and the process proceeds to step S138.
If it is determined in step 119 that "move left", step S1
At step 39, the overhang body 7 is returned to its original position (FIG. 7), the F register is reset, and each step S1
Move on to 15.

In step S109, when the operation panel 16 is operated to give a rotation command for the swivel base 3, this command is taken into the hydraulic control device 15, and the hydraulic motor 25 is immediately driven to rotate (step S140). Step S
In step 141, it is determined whether the desired rotation angle has been reached, and if the desired rotation angle has not been achieved, the process returns to step S109, and if the desired rotation angle has been achieved, the process moves to step S142.
Controls the operation panel 16 to stop. As a result, the hydraulic control device 15 stops the hydraulic motor 25 for the swivel table 3 (step S143), and stores the rotation angle direction in a predetermined storage means (RAM 33) (step S144). This direction of rotation can be updated each time the boom 4 is moved, and the RAM 33 is reset when the boom 4 returns to its basic position.

Now, an example of the operation will be explained using the above flowchart.

Boom 4 at the same time in steps S107 and S108
Assuming that the elongation and depression angle of S are controlled, step S
110, S120 → S110 to S116, S12
1 and the boom 4 extends from the state shown in FIG. 7 to the state shown in FIGS. 1 and 2. Then, when the boom 4 is in the desired state, steps S117 to S118 and S122 to S123 are performed, respectively.
and stop.

Next, the process moves to step S109, and the process proceeds to step S109.
Processes 140 to S141 are performed, and the swivel base 3 is rotated. If steps S142 to S144 are performed when the swivel base 3 reaches the desired rotational position, the eighth
It will look like the figure.

Furthermore, when the operation panel 16 is operated in step S108 and a command to reduce the depression angle of the boom 4 is issued, steps S120, S111 to S115, and
The processes of S119 and S121 are repeated. Furthermore, in this loop, if it is determined in step S114 that the situation is dangerous, the processes from step S124 onwards are performed (steps S124-134). As a result, as shown in FIG. 9, the vehicle body 2 moves in the opposite direction to the overturning direction and becomes safe, so the boom 4 can be controlled to further reduce its depression angle, as shown in FIG. This allows the boom 4 to be placed in a horizontal position. Further, when the operator leaves the dangerous angle, the process always moves from step S114 to step S119, so that the overhanging body 7 is set to its original position (FIG. 7).

Since the present embodiment operates in this way, when the vehicle body 2 enters the dangerous area (outside the area indicated by the diagonal lines x, y, and z in FIG. 4), it can automatically move the vehicle body 2 to the opposite side of the overturning direction, and the center of gravity can be moved. It maintains balance and prevents falls. After leaving the dangerous angle, the vehicle body 2 can return to its original position (FIG. 7).

〔Effect of the invention〕

According to the present invention, as described above, it is possible to significantly reduce the danger range of the boom overturning and expand the working range. For this reason, the conventional workable area shown with diagonal lines in Fig. 4 (X, Y, Z
The safe working range (x, y, z range) in this embodiment is wider than that in the range of
This allows you to expand the range of work you can do.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment according to the present invention, FIG. 2 is a side view showing the same embodiment, FIG. 3 is a system diagram showing a hydraulic control system, and FIG. 4 is an explanatory diagram showing a safety area. Fig. 5 is a system diagram showing the fall prevention mechanism of the same embodiment, Fig. 6 is a flowchart shown to explain the operation of the embodiment, and Figs. 7 to 9 explain the operation of the embodiment. FIG. 2...Vehicle body, 3...Swivel base, 4...Boom, 7...Overhanging body, 9...Lifting mechanism, 10...Length measurement sensor, 1
4... Angle sensor, 15... Hydraulic control device, 26...
ROM, 29...hydraulic circuit, 30...control device.

Claims (1)

[Scope of Claims] 1. An aerial work vehicle in which a boom is pivotally supported on a swivel platform that is rotatably provided on the vehicle body so as to be extendable and retractable, and a bucket is pivotally attached to the tip of the boom. An overhang body that can be expanded and contracted in the horizontal direction is provided on both sides, an outrigger is provided at the tip of each of these overhang bodies to lift up the vehicle body, and the overhang body has a hydraulic actuation mechanism that can move the lifted vehicle body in its length direction. The boom is equipped with a length sensor that can measure its extension and contraction length, and an angle sensor that can detect the angle of the boom from the horizontal, and the overhang body is equipped with a position sensor that detects the distance from the outrigger to the vehicle body. , takes in the detection signals from the length measurement sensor and the angle sensor, compares them with preset fall risk range data, and when it is determined that the vehicle is in the fall risk range, determines the position of the vehicle body using the position sensor. A vehicle for working in high places, characterized in that it is equipped with a hydraulic control device that can drive and control the hydraulic actuating mechanism to move the vehicle body along the length of the overhanging body in a direction opposite to the direction in which there is a danger of falling. Fall prevention mechanism.