JPH0224759B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fall prevention mechanism for a vehicle for working at height, and in particular for work at height, which reduces the danger angle of a boom overturning and automatically corrects the balance. Regarding a vehicle fall prevention mechanism.

[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 bucket lifts that allow workers to swivel, rise and fall, or expand and contract toward telephone poles or walls while carrying workers on them, allowing them to work at high places without scaffolding (so-called boom-type lifts).

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]

Such conventional high-place work has a problem in that the safe work range is narrow, resulting in a limited work range.

The present invention has been made in order to solve the above-mentioned problems, and by performing a balance correction operation, the risk angle of the boom toppling is reduced and the working range is widened, and the tip of the boom is adjusted to the above-mentioned balance correction operation. An object of the present invention is to provide an overturn prevention mechanism for an aerial work vehicle that can always maintain the same position.

[Means to solve problems]

The present invention, which solves the above-mentioned problems, has a swivel base that is rotatably provided on a vehicle body, a boom that is pivotably supported on the swivel base and is movable telescopically by a depression angle cylinder and a telescoping cylinder, and the boom. An aerial work vehicle consisting of a bucket that is pivotally attached to the tip of the vehicle body is provided with overhanging bodies that can expand and contract horizontally on both the left and right sides of the vehicle body, and outriggers that lift the vehicle body are provided at the tips of these overhanging bodies. is equipped with a hydraulic mechanism that can move the lifted vehicle body horizontally to the side, and the boom is equipped with a length measurement sensor that can measure the length of extension and contraction, and an angle sensor that can detect the angle of the boom from the horizontal. In addition to providing a sensor, a position sensor for detecting the distance from the outrigger to the vehicle body is provided on the overhanging body, and the detection signals from the length measurement sensor and angle sensor are taken in, and this is used as preset fall risk range data. When it is determined that the vehicle is in the overturn danger range, the position sensor determines the position of the vehicle body and drives and controls the above-mentioned hydraulic actuation mechanism, and the vehicle body is moved in the opposite direction of the overturn danger direction according to the length direction of the overhanging body. In addition to being able to control movement in the direction,
Hydraulic control that controls the tip of the boom to remain in the same position even if the vehicle moves by driving the depression angle cylinder and telescoping cylinder to correct the angle and length of the boom in response to vehicle body movement. It is equipped with a device.

[Effect]

First, the lifting mechanism is set in a predetermined position to secure the vehicle body. 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. Further, the control device drives and controls the boom angle and length according to the movement of the vehicle body. As a result, by moving the center of gravity to the opposite side of the boom and maintaining balance, it is possible to prevent the boom from tipping over, and the tip of the boom can remain on the same line even though the vehicle body is moving.

〔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 telescoping cylinder (not shown), and the bucket 5 is controlled to always be in a horizontal state by a balance cylinder (not shown). I'm letting you do it. Boom 4 and swivel base 3
A depression angle cylinder 6 for controlling the elevation angle is provided between the
are arranged. The vehicle body 2 has projecting bodies 7 disposed vertically on both the left and right sides of the front and back thereof,
A lifting mechanism 9 consisting of outriggers 8 provided on these is provided.

Furthermore, a length measurement 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 measurement sensor 10 is of a tape measure type, and its main body 11 is provided 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.

In addition, the front or rear overhanging bodies 7R, 7L are equipped with length measurement sensors 17R, 17R, which can measure the extension/contraction length thereof.
17L is provided. This length measurement sensor 17R,
The length measuring sensor 17L may have the same structure as the length measuring sensor 10, and its main body is attached to the base of the projecting bodies 7R and 7L of the vehicle body 2, and the tip of the band body is fixed to the outrigger 8.

FIG. 3 shows a hydraulic control system including a fall prevention mechanism. The hydraulic control device 15 takes in signals for operation commands from the operation panel 16, and also controls the length measurement sensor 10, the angle sensor 14, the overhang body 7R,
It receives signals from the length measurement sensors 17R and 17L for 7L, and controls pressure oil discharged from a hydraulic pump 19 driven by a drive device 18 based on commands from the operation panel 16 or these command signals. and each cylinder 6, 20, 21, 22R, 2
2L, 23R, 23L, 24 and a hydraulic motor 25 for driving the swivel base 3 can be controlled. The hydraulic control device 15 has a built-in ROM 26 that stores safety areas (shaded areas X, X, Z) as shown in FIG.
The calculation result is stored in ROM26 based on the signal from 7L.
When it is determined that the above-mentioned safety ranges X, 2 is moved. As a result, the safety areas X, X, and Z in FIG. 4 are expanded to areas x, y, and z shown by broken lines, and the areas are widened.

FIG. 5 shows the equipment configuration of the overturn prevention mechanism in 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, and the output side of the electromagnetic switching valve 41 and the telescopic cylinder 20 are connected by pipes 47, 48. Solenoid switching valve 4
Piping 49,5 connects the output side of 2 and the depression angle cylinder 6.
0, and the output side of the electromagnetic switching valve 43 is connected to the series-connected cylinders 22R and 23R for the right side overhang body via piping 51, 52, and the output side of the electromagnetic changeover valve 44 is connected to the cylinder for the left side overhang body. 22
Pipes 53 and 54 are connected in series with L and 23L.
It is configured by connecting through. Each of the electromagnetic switching valves 41 to 44 is connected to the DO 36 of the control device 30.
It is designed to be switched by a switching command from the CPU 31 outputted via the
Each electromagnetic switching valve 41 to 4 receives hydraulic oil according to the command.
It is possible to output to the output side of 4.

FIG. 6 is a block diagram showing the fall prevention mechanism of FIG. 5.

In this figure as well, the same components as those described above are given the same reference numerals and their explanations will be omitted.

In FIG. 6, 55 is a manual drive control unit; 56 is a manual drive control unit;
is the main calculation processing unit, 57 is the collation/control unit, and 58 is F.
59 is a G register, 60 is an overhang body drive control section, 61 is a correction drive control section, 62 is an alarm section, and 63 is an auxiliary calculation section.

The manual drive control unit 55 switches and controls the electromagnetic switching valves 41 and 42 based on the operation command from the operation panel 16 when the signal 65 is "1", and controls the switching of the electromagnetic switching valves 41 and 42 based on the operation command from the operation panel 16 when the signal 65 is "0". A signal based on the operation command is not output to the electromagnetic switching valves 41 and 42.

The main calculation processing unit 56 takes in signals from the sensors 10, 14, the auxiliary calculation unit 63, and other necessary signals, performs calculation processing on equations (1) to (4), which will be described later, and collates the calculation results. - It is designed to be supplied to the control section 57.

The collation/control unit 57, based on the calculation result,
The first safety area (X, Y, Z) or the second safety area (x, y,
z), and also checks the F register 58 and G register 59 according to the order of control, and when it is determined that it is in the first safe area, the S signal 65 is set to "1", and the second safe area is set. When the S signal 65 is temporarily set to "0", the movement control signal 66 is output to the overhang body drive control section 60, the correction control signal 67 is output to the correction drive control section 61, and the overhang body drive control section 60 When it is confirmed by the signal from the auxiliary calculation unit 63 that the movement of the overhanging bodies 7R and 7L has been completed, the signal 65 is set to "1", and the signals 66 and 67 are
When it is determined that the second safety area has been exceeded, the S signal 65 is set to “0” and the A
A signal 70 is output to the alarm section 62 of the operation panel 16.
When it is determined that what was in the second safety area has become the first safety area, a return control signal 68 is output to the overhang body drive control section 60, and a modified return control signal 69 is output to the modification drive control section 61. It is set as.

The F register 58 is set/reset by the collation/control section 57. The G register 59 is configured so that the direction of the swivel base 3 is set by the manual drive control section 55.

The electromagnetic switching valves 41 and 42 are controlled by a manual drive control section 55.
Alternatively, switching control is performed by the correction drive control section 61.

The electromagnetic switching valves 43 and 44 are switched and controlled by the overhang body drive control section 60 while being automatically controlled.

Note that the manual drive control section 55, the main calculation processing section 56,
The collation/control unit 57, the correction drive control unit 61, the overhang body drive control unit 60, and the auxiliary calculation unit 63 are connected to the CPU 3.
1, and an F register 58 and a G register 59 are provided within the RAM 33.

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

FIG. 7 is a flowchart shown to prove the operation of this embodiment, FIG. 8 is a flowchart shown to explain correction control and correction return control operations, and FIGS. 9 to 11 are flowcharts shown to demonstrate the operation of this embodiment. It is an explanatory diagram shown in order to explain an effect.

First, the overhanging body 7 is extended to a predetermined length. This operation is performed by operating the operation panel 16 to issue an operation command (step S100), and receiving this command, the hydraulic control device 15 controls the overhang body cylinder 22.
Hydraulic oil is supplied to R, 22L, 23R, and 23L to extend each overhang body 7 (step S101), and a detection signal from each length measurement sensor 17R and 17L indicates that each overhang body 7 has been extended to a predetermined length. When the hydraulic control device 15 detects (step S102),
The supply of the hydraulic oil is stopped (step S10).
3) It is realized by

Next, the outriggers 8 are extended to raise the vehicle body 2 above the ground. This is accomplished by operating the operation panel 16 to issue an operation command (step S104), and having received this command, the hydraulic control device 15 supplies a predetermined amount of hydraulic fluid 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. These signals are input to the manual drive control section 55.

When an extension/retraction command for the boom 4 is issued via the operation panel 16 in step S107, the manual drive control section 5
5 drives and controls the electromagnetic switching valve 41 (this is DIO3
The instructions obtained through 4 are taken into the CPU 31,
By determining the command and controlling the electromagnetic switching valve 41 via the DO 36), hydraulic oil is supplied to the telescopic cylinder 20 to extend or retract the boom 4 (step S
110). 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 stored in the RAM.
33 (step S111). Next, using the data l and θ stored in the RAM 33, the main calculation processing section 56 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 calculation result from the main calculation processing section 56 is taken into the collation/control section 57, and the collation/control section 57 calculates the first one shown in FIG. Safety area (X, Y,
Z) is compared with the above calculation results, and the verification/control unit 57 determines whether or not it is in the safe area (step S114). In step S114, if the collation/control unit 57 determines that it is in the safe area (YES),
Proceeding to step S115, the F register 5 is
8 is checked to determine whether it was the previous abnormality processing loop, and if there is no abnormality, the S signal 65 is set to "1" and the process moves to step S116.

In step S116, the current control is
If it is length control, the process moves to step S117, and if it is determined that the desired length has been reached, the operation panel 16 is operated in step S117 to give a stop command for boom length control to the manual drive control section 55. .
Then, CPU31 obtained this through DIO34
then moves the electromagnetic switching valve 41 to the stop position via the DO 36 and stops it (step S118). Note that if the desired length is not found in step S116, the process returns to step S107.

In step S108, when the operation panel 16 is operated and a command to control the angle of the boom 4 is issued, the manual drive control device 55 controls the electromagnetic switching valve 42 (this command is taken into the CPU 31 via the DIO 34). (by controlling the electromagnetic switching valve 42 via the DO 36), hydraulic oil is supplied to the depression angle cylinder 6 and the boom 4 is lifted (step S120).

Next, the main calculation processing unit 56 calculates each sensor 10,
14 (step S111),
Based on this, the main calculation processing section 56 performs calculations (step S112), and provides the results to the collation/control section 57. The verification/control unit 57 verifies the first safe area (X, Y, Z) shown in FIG.
Then, the F register 58 is checked, and on the condition that the abnormality processing loop has not been passed, the process moves to step S116. Since it is determined in step S116 that angle control is required, when it is determined in step S121 that the desired angle has been reached, the operation panel 16 is operated in step S122 to issue a command to stop the angle control of the boom 4. Then, the manual drive control unit 55 sets the electromagnetic switching valve 42 to the stop position (this means that the CPU 31, which received the command via the DIO 34, switches the electromagnetic switching valve 42 to the DO position.
36 to the stop position) to stop the angle control of the boom 4 (step S123). Note that if it is determined in step S121 that the angle is not the desired angle, the process returns to step S108.

On the other hand, the collation/control unit 57 collates the calculation result from the main calculation processing unit 56 with the ROM 26 (steps S111 to S114), and when it is determined that the second safety area has been exceeded, the collation/control unit 57
Check the register 58 (step S124),
When nothing is set in this F register 58, the process moves to step S125, and the verification/control unit 57 sets the signal 65 to "0" in order to stop the movement of the boom 4.
(This means that the CPU 31 stops the operation of the electromagnetic switching valve 4 via the DO 36.
1, 42 to the stop position).

Next, the collation/control unit 57 collates the G register to determine data regarding the direction of the boom 4 (step S126), and if it is "right", the data is determined in step S126.
In step S127, if it is "left", the process moves to step S128. The control in step S127 is performed by the verification/control unit 5.
7 outputs a movement control signal 66 to the overhang body control unit 60 to drive the electromagnetic switching valves 43 and 44 (this
CPU31 is an overhang body cylinder 22L, 23L
and the overhang body cylinders 22R, 2
3R).

At the same time, a correction control signal is supplied from the verification/control section 57 to the correction drive control section 61, and a signal for correction control is given to the electromagnetic switching valves 41 and 42 (this is done by the CPU 31 via the DO 36). Step S129)). Note that the correction control operation will be described later, but as a result of this, the packet 5 remains at a fixed position regardless of the movement of the vehicle body 2.

The control in step S128 is performed by the verification/control unit 5.
7 sends a movement control signal 66 to the overhang body drive control section 60.
and drives the electromagnetic switching valves 43 and 44 (this is because the CPU 31 operates the overhang body cylinders 22L and 2
3L is extended and the overhang body cylinder 22
Solenoid switching valve 41, so as to retract R, 23R.
42). At the same time, a correction control signal is given from the verification/control unit 57 to the electromagnetic switching valves 41 and 42 (this is
This is performed by the CPU 31 via the DO 36 (step S130). This correction operation will also be described later. After completing steps S129 and 130, step S
The process moves to step S131, where it is determined whether the overhanging body 7 has moved to a predetermined length, and if it has not moved, the process proceeds to step S1.
The process returns to step S132, and if it has moved, the process moves to step S132. For example, step S126→128→130
→ When each step 131 is completed, the state will move from the state shown in FIG. 9 or 10 to the state shown in FIG. 11 if attention is paid only to the relationship between the vehicle body 2 and the overhang body 7.

In step S132, the collation/control unit 57
The signal 65 is set to "1" to permit movement of the boom 4 that was stopped in step S125, and verification/
The control unit 57 sets the F register 58 in step S133.
Set whether the vehicle body 2 is moved to the "right" or "left". The detection signals (l, θ) from the sensors 10 and 14 are stored in the RAM 33 via the input circuit 35 (step S134). Next, the main calculation processing unit 56 calculates equations (1) and (2). In other words, based on the data (l, θ) from RAM33
The CPU 31 calculates the above equations (1) and (2) (step S135).

The verification/control unit 57 operates in a second safety area (x,
y, z) with the calculation result from the main calculation processing unit 56 (step S136), and if it is determined to be safe, the process moves to step S166, and if it is determined to be dangerous, the process moves to step S138. Verification/
The control section 57 issues an alarm by giving the A signal 70 to the alarm section 62 as a process in step S138, and then controls the stop by setting the S signal 65 to "0" (this is done by the CPU 31 via the DO 36 to control the electromagnetic switching valve). 41 and 42 to the stop position (step S139)).

By the way, once you get out of the first safety area,
The process always moves to step S124, but in the case of the second or subsequent flow, the process moves to step S134 in step S124.
Therefore, only a determination is made as to whether or not it is within the first and second safe areas.

When the first safe area is entered again in step S114, the process moves to step S115, where the F register 58 is checked by the collation/control unit 57. Here, since the process from step S124 to step S137 has been carried out because it has entered the danger range more than once, "right" is written in the F register 58.
Since “left” is set, step S14
It will move to 0.

First, the collation/control unit 57 sets the signal 65 to "0" to temporarily stop the movement of the boom (step S1).
40). Next, the collation/control unit 57 collates the G register 59 and determines the direction of the boom 4 (step S141). When the boom 4 is facing to the right, the process moves to step S142, and the verification/control unit 5
A signal is given from 7 to the overhang body drive control section 60 to control the vehicle body 2 to move to the right and return to its original position. Next, the collation/control unit 57 gives a correction return control signal to the correction drive control unit 61 so that the tip of the boom 4 remains at the same position even if the overhang body cylinders 22R, 22L, 23R, and 23L return. control (step S143). Next, the verification/control unit 57 determines whether the vehicle body 2 has returned to its original position based on the signal from the auxiliary calculation unit 63, and if it has not returned to its original position, the process moves to step S141.
When it returns to the original state, the process moves to step S148. In step S148, the verification/control unit 57 receives the S signal 65.
is set to "1" to cancel the temporary stop and proceed to step S1.
In step S49, the collation/control unit 57 resets the F register 58, and then proceeds to step S116. Note that steps S146 and S147 are different from steps S142 and S147.
This is the same control as S143, only the direction is different.

FIG. 8 is a flowchart showing correction control and correction return control, and the operation thereof will be explained based on this, but before that, the principle employed in this flowchart will be explained.

FIG. 12 is an explanatory diagram shown to explain the principle of correction control and correction return control.

In FIG. 12, P is the tip of the boom 4, O is the pivot point of the boom 4, V is the height to the tip P, and H is the horizontal distance between the pivot point O and the tip P. At the time when it is determined to be in the dangerous range, let the height be V(a), the horizontal distance H(a), the length l(a) of the boom 4, and the angle θ(a).

Here, in order to keep the tip P in the same position when the vehicle body 2 moves by Δθ in the direction of arrow M, θ(b)=tan ^-1 {V(a)/(H(a)+ΔH)} , l(b)=V(a)/sinθ(b). Furthermore, if we move by ΔH,
In order to keep the tip P at the same position, θ(c)=tan ^-1 {V(a)/H(a)+2ΔH)}, l(c)=V(a)/sinθ(c). Bye. Therefore, depending on the movement of the vehicle body, θ(b)=tan ^-1 {V(a)/(H(a)+ΔH)}, θ(c)=tan ^-1 {V(a)/( H(a)+2ΔH)}, ... θ(x)=tan ^-1 {V(a)/(H ₀ +xΔH)} = tan ^-1 {V(a)/H(a)+H(x))} , ... θ(n)=tan ^-1 {V(a)/H(a)+nΔH)}, =tan ^-1 {V(a)/H(a)+H(n))} l(b)= V(a)/sinθ(b) l(c)=V(a)/sinθ(c)...l(x)=V(a)/sinθ(x)...l(n)=V(a) /sinθ(n). Therefore, each time the vehicle body 2 moves in this way, the angle θ is calculated based on the horizontal movement distance H(x).
(x) and boom length l(x), and this angle θ
(x) and the length l(x) to match the actual length, the tip P will remain at that position.

Conversely, if the vehicle body 2 moves in the direction of arrow N when the pivot point is on, the following procedure may be used.

θ(n) = tan ^-1 {V(a)/(H(a)+H(n))}, θ(n-1) = tan ^-1 {V(a)/(H(a)+H(n )−ΔH)} ... θ(x)=tan ^-1 {V(a)/(H(a)+H(n)−H
(x))}, ... θ(b)= tan ^-1 {V(a)/(H(a)+H(n)-H(n-1))
}, θ(a)=tan ^-1 (V(a)/H(a)) l(n)=V(a)/sinθ(n) l(n-1)=V(a)/sinθ(n -1) ... l(x) = V(a)/sinθ(x) ... l(b) = V(a)/sinθ(b) l(a) = V(a)/sinθ(a) This If the actual angle and boom length are matched to θ(x) and l(x) obtained in this way, the N of the vehicle body 2 is
Regardless of the direction of movement, the tip P remains at the same position.

Now, correction control and correction return control that operate based on the above principle will be explained with reference to the flowchart of FIG. 8. The flowchart of FIG. 8 includes steps S120 and S130 or step S14 of the flowchart shown in FIG.
3 and S147 are explained in detail.

In step S200, the collation/control unit 57 determines whether the control is correction control or correction return control.

Here, the operation when it is determined that corrective control is required will be explained. When it is determined that the corrective control is required, the process moves to step S201, and the process moves to step S202 or S203 depending on whether the direction of the boom 4 is "right" or "left" in step S201. This is to make it easier to use the input data from the angle sensor 14.
Next, in step S204, the boom 4 is designated as extension control, the angle is designated as descending control, and the formula to be used is designated to use equation (3-1).

Next, the main calculation processing section 56 executes the auxiliary calculation section 63.
The boom angle θ(x) is calculated using equation (3-1) specified in step S204 based on the data from
is calculated and the result is given to the verification/control section 57.

θ(x)=tan ^-1 {V(a)/(H(a)+H(x))}
...(3-1) However, H(a) is the horizontal distance between the bucket and the lower end pivot point (boom 4) when moving from the first safety area to the danger area for the first time.

V(a) is the vertical distance between the tip of the boom 4 and the lower end pivot point of the boom 4 when moving from the first safety area to the danger area for the first time.

H(x) is the horizontal movement distance of the vehicle body 2.

In step S206, the main calculation processing unit 56
Based on θ(x) obtained in step S205 above,
The boom length l(x) is calculated using equation (4) and the result is provided to the collation/control unit 57.

l(x)=V(a)/sinθ(x)...(4) In step S207, first, the verification/control unit 57
Since the correction control signal 67 is given to the correction drive control section 61, the correction drive control section 61 drives and controls the electromagnetic switching valve 41 to extend the telescopic cylinder 20. Next, the collation/control unit 57 collates θ(x) obtained in step S205 with the actual measurement value from the angle sensor 14, and if they do not match, the collation/control unit 57 sends the correction control signal 67 to the correction drive. The control unit 61 is controlled to lower the depression angle cylinder 6 (step S209). Then,
In step S210, θ obtained in the previous step is
(x), the actual measurement value from the angle sensor 14, and l(x) obtained in the previous step and the length measurement sensor 1.
It is determined whether both of the actual measured values from 0 match, and if they do not match, step S2
Moving on to step 11, it is determined whether l(x) matches the actually measured value. If they do not match in step S211, the process moves to step S207, and if they match in step S211, the process moves to step S213, where the correction drive control section 61 is controlled to stop the movement of the telescopic cylinder 20, and then Afterwards, the process moves to step S209.

If θ(x) and the actual measured value match in step S208, the process moves to step S212, and the driving of the depression angle cylinder 6 is stopped.

When both match in step S210, the process moves to step S214, and in this step, the correction drive control unit 61 is controlled by the verification/control unit 57 to stop the telescopic cylinder 20 and the depression angle cylinder 6. Ru. With the above control flow, regardless of the movement of the vehicle body 2, the bucket 5
The position and height of remain at the position immediately before the vehicle body 2 started moving.

On the other hand, the operation when it is determined in step S200 that the correction return control is to be performed will be explained.

In step S215, the direction of the boom 4 is determined. This determination method is the same as described above. Further, steps S216 and S217 are similar to step S202.
and S203 are the same. Next, step S2
In step 18, control is specified to retract the telescoping cylinder 20, control to raise the depression angle cylinder 6 is specified, and equation (3-2) is specified as the equation to be used. After passing through step S218, the process moves to step S205, and the subsequent operations follow the same flow as described above, but are opposite to those described above. That is, even if the vehicle body 2 moves back to its original position, the bucket 5 remains at the position and height immediately before the corrective return control was started.

Here, equation (3-2) is shown.

θ(x)=tan ^-1 {V(a)/(H(a)+H(n)-H(x))
(3-2) 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 swivel (step S150). Step S
In step 151, the operator determines whether the desired rotation angle has been reached. If the desired rotation angle has not been achieved, the process returns to step S109; if the desired rotation angle has been achieved, the process returns to step S152.
Then, the operation panel 16 is controlled to stop. As a result, the hydraulic control device 15 stops the hydraulic motor 25 for the swivel base 3 (step S153), and stores the rotation angle direction in a predetermined G register (provided in the RAM 33) 59 (step S15).
4). This direction of rotation can be updated each time the boom 4 is moved, and the G register 59 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 S117, S12
1 and the boom 4 extends from the state shown in FIG. 9 to the state shown in FIGS. 1 and 2. Then, when the boom 4 is in the desired state, steps S117 to S119 and S121 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 S152 to S154 are performed when the swivel base 3 reaches the desired rotational position, the first
It will look like Figure 0.

At this time, if it is determined in step S114 that it is dangerous, the processing from step S124 onwards is performed (steps S124-137). This allows the first
As shown in FIG. 1, the vehicle body 2 moves in the opposite direction to the overturning direction, making it safer. At this time, the process shown in FIG. 8 is performed, and the bucket bag 5 is kept at a constant position. As shown in FIG. 11, the vehicle body 2 moves from the broken line state to the solid line state, but the bucket bag 5 can remain in its original position. Furthermore, when the operator leaves the dangerous angle, the process always moves from step S114 to step S115, so that the projecting body 7 is set to its original position (FIG. 10). At this time, even if the process shown in FIG. 8 is performed and the vehicle body 2 moves from the solid line to the broken line as shown in FIG.
can remain in its original position.

Since this embodiment operates in this way, when the first danger area (outside the area indicated by the diagonal lines X, Y, and Z in FIG. 4) is reached, the vehicle body 2 is automatically moved to the opposite side of the overturning direction and the bucket truck is moved. 5 can be kept at the original position, the center of gravity is balanced, and since the bucket 5 does not move, it is possible to prevent it from falling over, and there is no danger due to the bucket shifting. When the vehicle body 2 leaves the dangerous area, it can return to its original position (FIG. 10).

〔Effect of the invention〕

According to the present invention, as described above, the work area can be enlarged by significantly reducing the danger range of the boom overturning, and there is also the advantage of safety because there is no movement of the tip of the boom.

[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 block diagram showing the fall prevention mechanism, Fig. 7 is a flow chart shown to explain the operation of the same embodiment, and Fig. 8 is a system diagram showing the fall prevention mechanism of the same embodiment. A flowchart showing correction control and correction return control, FIGS. 9 to 11 are explanatory diagrams for explaining the same embodiment, and FIG. 12 is an explanatory diagram shown for explaining the principle of correction control and correction return control. It is. 2...Vehicle body, 3...Swivel base, 4...Boom, 7...Extended body, 9...Lifting mechanism, 10...Length measurement sensor,
14... Angle sensor, 15... Hydraulic control device, 26
...ROM, 29...hydraulic circuit, 30...control device, 5
5... Manual drive control section, 56... Main calculation processing section, 57
... Collation/control section, 58... F register, 59... G register, 60... Overhang body drive control section, 61... Correction drive control section.

Claims (1)

[Scope of Claims] 1. A swivel base that is rotatably provided on the vehicle body, and a boom that is pivotally supported by the swivel base and that can be telescopically operated using a depression angle cylinder and a telescopic cylinder.
The above-mentioned aerial work vehicle consists of a bucket that is pivotally attached to the tip of the boom, and overhangs that can be extended and contracted in the horizontal direction are provided on both the left and right sides of the vehicle body, and outriggers that lift the vehicle body are provided at the tips of these overhangs, and the overhang The body is equipped with a hydraulic mechanism that can move the lifted vehicle horizontally to the side, and the boom is equipped with a length sensor that can measure the length of the boom.
An angle sensor that can detect the angle of the boom from the horizontal is provided, and a position sensor that detects the distance from the outrigger to the vehicle body is provided on the overhanging body, and the detection signals from the length measurement sensor and angle sensor are captured and When it is determined that the vehicle is in the fall danger range by comparing it with the set fall risk range data, the position sensor determines the position of the vehicle body and drives and controls the above-mentioned hydraulic actuating mechanism to extend the vehicle body to the length of the body. The vehicle body can be controlled to move in the direction opposite to the direction in which the vehicle is at risk of overturning, and the angle and length of the boom can be corrected by driving the depression angle cylinder and telescoping cylinder in response to the vehicle body movement. A fall prevention mechanism for an aerial work vehicle, characterized in that it is equipped with a hydraulic control device that controls the tip of the boom so that it remains in the same position even when the boom is in the same position.