JPH01242399A - Safety device for high place working vehicle - Google Patents

Abstract

PURPOSE:To ensure safety in high-place works and enhance the working efficiency by selecting the safe revolution circle of a boom on the basis of signal from a left/right region selector switch to be changed over according to the overhang amount of an outrigger and the left/right position of the boom. CONSTITUTION:Signal about the left/right outrigger overhang positions by sensing means 13R, 13L and a judging means 16 are changed over by the signal from a boom left/right position sensing means 14. The signal is fed into a safe region judgement drive command means 20 via a left/right region selector switch 17, and a revolution circle selecting part 21 selects a safe revolution circle in the left or right region. On the basis of this safe revolution circle, a safe region judging part 23 actuates a boom elongation/fall restricting device 44 when the safe revolution circle is exceeded by the revolution circle or gondola, which is calculated from the amount of elongation and angle of rising/falling of the boom given by sensing means 11, 12. When a revolving direction sensing means 26 senses transition from the fore-and-aft region to the left/right region, a boom revolution regular direction restricting means 36 is actuated. Thus high-place works can be carried out safely and effectively.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a safety device for an aerial work vehicle. - This relates to a safety control device that can prevent the vehicle body from overturning by restricting the operation of the actuators for extending/contracting, raising and lowering, and turning when the tip of the rotating boom deviates from the safety area.

(Prior Art) The aerial work vehicle 1 is equipped with a boom 2 having a gondola 7 attached to its tip as shown in FIG.
Or by lever operation by the operator on the vehicle body side B.
The boom 2 is adapted to extend and contract, raise and lower, and turn in both left and right directions as appropriate.

Due to this operation, the gondola 7 is displaced to a desired position,
The operator of the gondola 7 can perform necessary high-altitude work. Such operation of the boom 2 is performed by appropriately switching a hydraulic switching valve provided in a hydraulic circuit. The boom 2 can be extended and contracted, raised and lowered, and rotated by hydraulic oil introduced from the hydraulic pump into actuators such as the telescopic cylinder 3, the luffing cylinder 4, and the swing motor 5. Outriggers 6 are installed at four locations on the front, rear, left, and right sides of the vehicle body and are extendable horizontally and vertically.
The outriggers 6 are extended, and while the workers inside the gondola 7 continue working, the outriggers 6 support the vehicle body.

In the schematic plan view of FIG. 11, when the outrigger 6 is extended as shown by the solid line, the inside of the great turning circle area, and overturning of the vehicle body is avoided. When the outrigger 6 has a medium extension, it can operate safely within the turning circle Y shown by the broken line, and when the outrigger 6 has a small extension, it can only operate within the small turning circle Z shown by the two-dot chain line. can continue. Therefore, if the turning circle corresponding to the amount of extension is deviated from, the boom extension, lowering, and in some cases, the turning operation will be automatically restricted, and the boom will be retracted or raised to allow the gondola to temporarily return to the turning circle. To ensure safety, they must be brought back inside. In addition,
The safety area is circular because the gondola safety area detection device can have an extremely simple structure such as a copying mechanism.

[Problem to be solved by the invention]

By the way, the rectangle formed in plan by the four legs of the outrigger extending to the side of the vehicle body is not necessarily a square. In other words, it is generally a rectangular shape that is long from front to back, except when the amount of overhang is maximum.

As a result, the displacement region of the gondola in which the vehicle body does not overturn becomes a long region in the longitudinal direction corresponding to the amount of extension of the outriggers. However, since a perfect circle is adopted as the safe area for the reasons mentioned above, even though it is actually safe in the front and back areas,
Gondolas are not allowed to enter the area.

This will be explained with reference to FIG. If the turning circle is divided by an angle of, for example, 15 degrees to the left and right with respect to 1 m of the vertical line of the aerial work vehicle 1, the turning circle Y when the overhang amount is not the maximum
Alternatively, even in the case of a small turning circle Z, the vehicle body will not fall over even if it advances to a large turning circle X within 30 degrees of the front and back. However, as described above, the gondola cannot advance beyond the turning circle to the shaded area because it is restricted by the turning circle according to the amount of each projection. If you want to displace the gondola beyond the safe area, you must either increase the amount of outrigger extension, or if the road is narrow and it is not possible to change the amount of extension, you must move the vehicle body. First, there is the problem that the efficiency of working at heights is significantly reduced.

In addition, when working at high places while parking on a narrow road, the right side outrigger 6 in Fig. 11 should have a medium extension as shown by the broken line, and the left side should have a medium extension. It is often shown as small, as shown by the dotted chain line. When boom 2 is on the right side, gondola 7 should be able to advance to turning mid-circle Y, but considering that gondola 7 will move to the left side, the safety range of the entire area is restricted to turning small circle Z. . Therefore, on the right side, there is a problem in that the gondola 7 can only be displaced within a narrow range that leaves a safe area in which it can advance.

The present invention was made to solve the above-mentioned problems.
The purpose of this is to ensure that when the right and left outriggers are extended differently, a safety range is ensured based on the amount of extension of each outrigger on the right and left sides of the vehicle;
It is an object of the present invention to provide a safety device for an aerial work vehicle that can expand the safety area within a certain angular area in the front and rear regions of the vehicle body, and can improve the efficiency of work.

[Means for Solving the Problems] The safety device for an aerial work vehicle of the present invention is such that the boom 2 (see Fig. 2) mounted on the vehicle body can freely extend and contract, raise and lower, and turn. This is applied to an aerial work vehicle that is equipped with outriggers 6 on both front and rear ends of the vehicle body that are extendable toward the sides and toward the ground and support the vehicle body posture. Its features are shown in the block diagram in Figure 1 and in Figure 2.
Referring to the figure, the boom extension amount detection means 11 detects the extension amount of the boom 2, the boom elevation angle detection means 12 detects the heave angle of the boom 2, and the boom extension amount detection means 12 detects the extension amount of the right outrigger 6. right outrigger extension amount detection means 13R, left outrigger extension amount detection means 13L that detects the extension amount of the left outrigger 6, right outrigger extension amount detection means 13R and left outrigger extension amount detection means 13L. an outrigger extension position determining means 16 for determining each extended position of the left and right outriggers 6 in response to signals from the left and right outriggers; A left/right region switching means 17 that receives a signal from the exit position determining means 16 and is switched by the operation of the boom left/right position detecting means 14, a boom extension amount detecting means 11, and a boom elevation angle detecting means 1.
After receiving the two signals, it is determined whether or not the boom 2 is located in the safe area based on the signal output by the operation of the left and right area changeover switch means 17, and when the boom 2 is in the safe area, the boom 2 is extended/contracted, raised and lowered, A safe area determination drive command means 20 that outputs a command signal that enables turning, a turning direction detection means 26 that detects the turning direction of the boom 2, and a signal from the safe area determination drive command means 20 and the turning direction detection means 26.
This is because a boom rotation forward direction regulating means 36 is provided which restricts the forward rotation direction of the boom 2 by the operation of , and allows the boom 2 to rotate in the opposite direction.

The features of the second invention will be described with reference to the block diagram in FIG.
2. Right outrigger extension amount detection means 13R1 Left outrigger extension amount detection means 13L, Outrigger extension position determination means 1
6. In addition to the boom left and right position detection means 14 and the left and right area changeover switch means 17, there is also a boom front and rear and lateral position detection means 18 that detects the turning position of the boom 2 separately in front and back and sides; The front/rear/lateral area changeover switch means 19 which is switched by the operation of the position detection means 18, the signals from the boom extension amount detection means 11 and the boom elevation angle detection means 12, and the operation of the front/back/side area changeover switch means 19 and In response to the signal output by the operation of the left/right area changeover switch means 17, it is determined whether or not the boom 2 is located in the safe area, and when the boom 2 is in the safe area, it is possible to extend/contract, raise/lower, and rotate the boom 2. A safe area determination drive command means 20 that outputs a command signal, a turning direction detection means 26 that detects the turning direction of the boom 2 by the operation of the front/rear/side area changeover switch means 19, and a safe area determination drive command means 20.
A boom turning forward direction regulating means 36 is provided which regulates the forward turning direction of the boom 2 and allows turning in the opposite direction based on a signal from the boom 2 and the operation of the turning direction detecting means 26.

[For production]

When the left and right outriggers 6 are extended, the outrigger extension amount is detected by the right outrigger extension amount detection means 13R and the left outrigger extension amount detection means 13L, and a detection signal is input to the outrigger extension position determination means 16. Outrigger 6
Each overhang position is determined. The boom left/right position output means 14 detects whether the boom 2 is located on the left or right side of the vehicle body, and the signal output by the switching operation of the left/right area changeover switch means 17 and the outrigger extension position are determined accordingly. In response to the signal from the means 16, the safe area determination drive command means 20 selects a safe turning circle when the boom 2 is in the right side area or a safe turning circle when the boom 2 is in the left side area. When the extension amount and luffing angle of the boom 2 are detected by the boom extension amount detecting means 11 and the boom luffing angle detecting means 12, it is determined whether the gondola 7 is in the safe area, and if it is in the safe area, the safe area determination drive is performed. The command means 20 outputs a command signal so that the boom 2 can be displaced, and the command means 20 outputs a command signal so that the boom 2 can be displaced.
It allows for expansion, contraction, undulation, and turning. Note that when the gondola 7 deviates outward from the turning circle in the circumferential direction, the extension and inclination of the boom 2 are restricted, and the desired displacement cannot be achieved unless the gondola 7 is returned to the turning circle.

On the other hand, when the boom 2 is rotating and moves from the right side to the left side or from the left side to the right side area, the displacement of the gondola 7 is regulated depending on whether or not it enters the turning circle of the transition destination. For example, if it does not fall within the allowable turning circle of the transition destination, the safe area determination drive command means 20 determines this, the turning direction detecting means 26 detects the turning direction at that time, and the boom turning is restricted in the forward direction. Activate circuit 36. As a result, it is possible to turn only in the direction opposite to the turning direction, and displacement in the original turning direction is prevented. In this way, the gondola 7 can be operated even if the outriggers 6 have different protruding amounts on the left and right sides.
The boom 2 can extend and contract, rise and fall, and turn within the allowable turning circle according to the amount of each extension.

In the second invention, the following operations are added to the above operations. When the gondola 7 is in the front-rear area, it is detected by the boom front-back/side position detection means 18, and the allowable turning circle in the safety area determination drive command means 20 is determined via the front-rear/side-area changeover switch means 19. The turning circle is expanded to the allowable turning circle when the outriggers are fully extended. therefore,
It can be displaced outside the permissible turning circle when in the lateral region. Incidentally, when the gondola 7 deviates from each allowable turning circle in the circumferential direction, it can be returned to the safe area in the same manner as in the case of the above-described invention, and thereafter the gondola 7 can be displaced to a desired position.

〔Effect of the invention〕

The safety device for the aerial work vehicle of the present invention is not limited to the turning circle determined by the position of the outrigger with the smaller amount of extension, even if the right and left outriggers have to be extended by different amounts. On the side where a larger outrigger exists, the gondola can be safely displaced within a turning circle according to the amount of outrigger overhang, and work efficiency in high-place work is significantly improved. When the gondola moves from the right side to the left side, for example, if the allowed turning circle at the destination is small and it would deviate from the safe area if it were to continue turning, further turning of the gondola will be restricted and the gondola will be forced to move in the opposite direction. By turning, the safety of the vehicle body is ensured.

In the second invention, in addition to the above effects, regardless of the amount of outrigger protrusion in the front and rear regions of the vehicle body,
When the amount of overhang is large, it is possible to advance and displace the area within the great turning circle.

Moreover, when the gondola transitions from the front and rear areas to the side areas, the allowed turning circle at the transition destination is small and if it continues to turn, it would deviate from the safe area, then the gondola's further turning is restricted and vice versa. By turning in this direction, the safety of the vehicle body is ensured.

〔Example〕

Hereinafter, the present invention will be explained in detail based on examples thereof.

Figure 2 shows an aerial work vehicle 1 to which the safety device of the present invention can be applied, in which a boom 2 mounted on the vehicle body can freely extend and contract, raise and lower, and rotate using a telescoping cylinder 3, a hoisting cylinder 4, and a swing motor 5. At the same time, outriggers 6 are installed on both sides of the front and rear ends of the vehicle body to support the vehicle body posture and are extendable and retractable toward the sides and the ground. The telescopic cylinder '3, the undulating cylinder 4, and the swing motor 5 are provided with respective hydraulic switching valves 8S shown in the hydraulic circuit of FIG. 3 provided on the side A of the gondola 7 and the side B of the vehicle body.

It is activated by switching levers 8T, 8U, 9S', 9T, and 90. Although not shown, the hydraulic jack that extends the outriggers 6 and lands them on the ground is operated by hydraulic oil from the hydraulic pump 10 in the same way as the telescopic cylinder 3 and the like.

As shown in the configuration diagram of FIG. 1, the safety device has a boom extension amount detection means 11 for detecting the extension amount of the boom 2, and a boom elevation angle detection means 12 for detecting the elevation angle of the boom 2. This is a known sensor provided near the cylinder 3 and the undulation cylinder 4. Right outrigger extension amount detection means 13R and left outrigger extension amount detection means 13L
For example, when there are three types of outriggers 6, large, medium, and small, as shown in the two examples in Fig. 4 (a) and (b), the left and right side extensions are respectively It detects the amount. Therefore, although not shown in detail, three limit switches 13a, 13b, and 13c are provided as shown in FIG. 5 to detect the amount of lateral movement of the outrigger 6.

The boom left and right position detection means 14 detects the turning position of the boom 2 separately on the left side and the right side. It consists of a cam plate 14A and a limit switch 14B shown in FIG.

The cam it 4A is disc-shaped and has a vertical line of 1 m (first
A semi-large circular cam surface 14a is formed on the right side, and a semi-small circular cam surface 14b is formed on the left side of the straight line 14m that coincides with the straight line 14m. The limit switch 14B attached to the vehicle body operates only while in contact with the semicircular cam surface 14a. Therefore, limit switch 1 determines whether boom 2 is in the left or right area.
It can be easily determined by the operation of 4B.

The outrigger extension position determination means 16 is an outrigger logic (see FIG. 5) that receives a signal from the above-mentioned left and right independent outrigger extension amount detection means 13R113L, and when the extension amount of the left and right outriggers 6 is large. - While determining whether it is medium or small, the signal of the determination result is output to the safety and area determination drive command means 20 via the left and right area changeover switch means 17, which will be described next. The output form is the transmission circuit 17A/! when the amount of extension of the left outrigger 6 is small. When the amount of overhang is medium, current is applied to the transmission circuits 11A1 and 1781, and when the amount of overhang is large, the current is applied to the transmission circuits 17A/118N.

A current is applied to 17C1. Furthermore, when the amount of extension of the right outrigger 6 is small, current is applied only to the transmission circuit 17Ar,
When the overhang amount is medium, current flows through the transmission circuits 17Ar and 178r, and when the overhang amount is large, the current flows through the transmission circuits 17Ar and 17Br.
, 17Cr. In addition, each transmission circuit 17Ar], 7A l, 17Br and 17B
J, 17Cr and 17Cr are respectively connected after the left and right area changeover switch means 17 to form transmission circuits 17A and 17B.
, 17C.

The left and right region switching means 17 receives a signal from the outrigger extended position determining means 16 and is switched by the operation of the boom left and right position detecting means 14.
AA, 17B7! , 17 (1 and 17Ar, 17Br
, 17Cr are interposed between the left switch 17L and the Ishikawa switch 17R. Then, by the operation of the boom left and right position detection means 14, the transmission circuits 11A1.17Bff, 17
Cj2 each switch or transmission circuit 17Ar, 17B
The r and 17Cr switches are configured to operate simultaneously.

The safe area determination drive command means 20 receives the signals from the boom extension amount detecting means 11 and the boom elevation angle detecting means 12, and determines whether the boom 2 is in the safe area by the signal output by the operation of the left/right area changeover switch means 17. It determines whether or not the boom 2 is located, and outputs a command signal that enables the boom 2 to extend/contract, raise/lower, and turn when the boom 2 is in the safe area. This includes a turning circle selection section 21, a safe area determination section 23, and a drive power supply section 24.

The turning circle selection section 21 includes the three transmission circuits 17 described above.
This moment limiter has the function of selecting a turning circle depending on the presence or absence of current from A, 17B, and 17C.

The safe area determination unit 23 determines the position of the gondola 7 based on the turning circle signal selected by the turning circle selection unit 21, the extension amount of the boom 2, and the heave angle signals from the boom extension amount detection means 11 and the boom heave angle detection means I2. is within the selected turning circle, that is, within the safe area. The drive power supply section 24 receives the signal from the safety area determination section 23 and outputs a signal for maintaining the extension/contraction, elevation, and rotation of the boom 2 if it is safe.

Note that when the safety area determining unit 23 determines that it is unsafe, it immediately restricts the extension and lowering operation of the boom 2, and also outputs a signal that restricts turning in the previous direction. Incidentally, the safe area determination unit 23 and the like are microcomputers, which are composed of a central processing unit, a fixed memory, a write memory, etc. (not shown), and can be made into a compact device. However, it goes without saying that a structure that achieves the same function using a mechanical structure may also be used.

The turning direction detection means 26 detects the turning direction of the boom 2 during turning. This is due to the movement of the piston 28 in the double-acting cylinder 27 shown in FIG. This is a changeover switch device designed to switch between OFF and OFF. The first oil chamber 27a is connected to the swing motor 5 via an oil passage 33a.
In the supply/discharge circuit 34 (see FIG. 3), the second oil chamber 27b is connected to a supply/discharge circuit 35 via an oil passage 33b. Therefore, if the swing motor 5 is rotating clockwise, the supply/discharge circuit 34
becomes high pressure, the first oil chamber 27a of the double-acting cylinder 27 also becomes high pressure, and the piston rod 29 moves rightward, opening the self-returning contact 32B while keeping the other contact 32A closed. When the rotating direction of the swing motor 5 is reversed, the contact 32A is opened while the contact 32B is kept closed. Due to this operation, the operation of the boom rotation forward direction regulating circuit 37, which will be described below, is differentiated depending on the rotation direction of the rotation motor 5.

In this example, the double-acting cylinder 27 is used to detect the turning direction, but a gear-shaped concentric disk (not shown) is integrated on the bottom surface of the cam plate 14A, etc. The contact 32 is connected by a lever that collapses when the teeth move.
A and 32B may be configured to operate as a disconnection. In that case, the lever will only hit one side of the tooth surface during a right turn and when it stops, so the lever will remain tilted to one side, and during a left turn and when it stops, the lever will be Only the other side of the south face will be hit, and the lever will remain in the state of falling to the other side.

The boom rotation forward direction regulating means 36 receives the signal from the above-mentioned safe area determination drive command means 20 and the rotation direction detection means 2.
The operation 6 restricts the boom 2 from turning in the forward direction, that is, the direction in which it has been turning so far, while allowing it to turn in the opposite direction. This consists of a boom rotation forward direction restriction circuit 37 and a rotation forward direction restriction device 38. The boom rotation forward direction regulation circuit 37 includes a keep switch 39A for regulating right rotation and a keep switch 39B for regulating left rotation.
It becomes more. The keep switch 39A includes a set relay coil ST1 provided in a set circuit 31A having a contact 32A, a switch rlL interposed in a circuit 40A directly connected to a power supply, and a center circuit 31 having a contact 32B.
It is composed of a switch rlR interposed in B, and a reset relay coil R5Tl provided in the reset circuit 41A. A solenoid drive circuit 52A, which will be described later, is connected to the circuit 40A with the switch rlL interposed therebetween, and a solenoid 5OLI of the first electromagnetic valve 38A, which is the rotation forward direction regulating device 38, is connected to the circuit 40A. In addition, the keep switch 39B includes a set relay coil ST2 connected in series to the switch rIR of the cent circuit 31B, a switch r2L connected in series to the set relay coil STI,
It is composed of a switch r 2 R% interposed in a circuit 40B directly connected to a power source, and a reset relay coil R3T2 provided in a reset circuit 41B. A solenoid drive circuit 52B is connected to the circuit 40B via the switch r2R, and the forward rotation direction regulating device 38 is connected to the solenoid drive circuit 52B.
The solenoid 5OL2 of the second solenoid valve 38B is connected. Note that the switches rlL, rlR, r2L,
r2R is a keep switch contact, and when the setting relay coil STI or Sr1 is driven, the switch r
lL, rlR or r2L, r2R are both opened, but the open state is maintained even if their driving is stopped.

Then, reset relay coil R5Tl or RS
When T2 is activated, switch rlL is in the open state.

When rlR or r2L or r2R returns, the circuit becomes energized, and the closed state is maintained even if the drive is stopped.

The first solenoid valve 38A and the second solenoid valve 38B are the third solenoid valve 38A and the second solenoid valve 38B.
The supply and discharge circuits 34 and 35 shown in the figure are interposed, and when the respective solenoids 5OLI and 5OL2 are demagnetized, the supply and discharge circuits 34 and 35 are closed. Since check valves 42 and 43 are arranged in parallel to each of these solenoid valves, for example, when only the first solenoid valve 38A is closed, the swing motor 5 is prevented from turning to the right, and only rotation to the left is allowed. It has become so.

In addition to the above configuration, there is also a boom extension/contraction/lowering permitting device' which allows the boom 2 to extend/contract and raise/lower based on a signal from the drive power supply unit 24, and a boom extension/lowering permitting device' that allows the boom 2 to extend/concline and raise/lower using a signal from the safety area determination unit 23. A boom extension legal regulation device is provided. In this example, these devices are one third solenoid valve 44 interposed in the hydraulic circuit. The third solenoid valve 44 includes a solenoid 5OL3 that is excited by power from a solenoid drive circuit 45 that receives a signal from the safe area determination drive command means 20 shown in FIG. 5 and supplies power.

When the solenoid 5OL3 is demagnetized, the third solenoid valve 44 opens the drain circuit 46 shown in FIG. Hydraulic oil is discharged into a tank 51 from oil passages 49 and 50 with check valves 47 and 48 interposed therebetween. therefore,
In this case, even if hydraulic oil is supplied by operating the switching valves 8S, 9S or 8T, 9T, it will be drained immediately.
The boom 2 cannot be extended or laid down. - On the other hand, when the solenoid 5OL3 is energized, the oil passages 49 and 50 do not communicate with the tank 51, and high-pressure hydraulic oil is supplied to the respective oil chambers 3a and 4a, allowing the boom 2 to extend, contract, and rise. be.

By the way, a solenoid drive circuit 52 is connected to the above-mentioned solenoid drive circuit 45, which can directly excite the solenoids 5OL1.5QL2 of the first solenoid valve 38A and the second solenoid valve 38B, which are the swing forward direction regulating device 38. . This is because, even though the safety area determining section 23 of the safe area determining drive commanding means 20 has determined that it is safe, the turning direction detecting means 26 is activated so that the forward turning direction regulating device 38 is always activated. This is to avoid restricting one direction of rotation of the rotation motor 5 by one of the solenoid valves 38A or 38B. Therefore, the first solenoid valve 38A and the second solenoid valve 38B also function as a boom rotation permitting device, as shown in FIG. Note that the diodes 52a and 52b interposed in the solenoid drive circuit 52 are connected to the solenoid drive circuit 52 when there is a potential difference between the circuit 40A and the solenoid drive circuit 52A, or between the circuit 40B and the solenoid drive circuit 52B. This is to prevent current from flowing to.

The safety device for an aerial work vehicle with such a configuration is configured as follows to ensure that the boom can extend, contract, raise, and swivel within safe areas on the left and right sides, even if the left and right outriggers 6 have different extension amounts. By selecting and operating within the safe range, the work efficiency of the aerial work vehicle can be improved. In addition,
This will be explained with reference to the flowcharts in FIGS. 6(a) to 6(d).

When the aerial work vehicle 1 stops at a predetermined position, the outriggers 6 are extended by a hydraulic jack. The limit switches 13a to 130 of the left outrigger extension amount detection means 13L and the right outrigger extension amount detection means 13R (see FIG. 5) operate to detect the left and right outrigger extension positions [steps in the flowchart]. 1 and 2, hereafter 81
etc.] When the overhang amount is the smallest among large, medium, and small, only the limit switch 13a operates.

When the amount of protrusion is medium, the limit/throat switch 13b is operated, and when the amount of protrusion is large, the limit/throat switch 13c is operated.
The signal is input to the outrigger extension position determination means 16. Although there are various combinations of left and right extension amounts, in the following explanation, as shown in Fig. 4(a), the left outrigger 6 has a small extension amount, and the right outrigger 6 has a medium extension amount. The case of the overhang amount will be described as an example.

The outrigger extension position determining means 16 determines that the amount of extension of the left outrigger 6 is the minimum (S3: l, and determines that the amount of extension of the right outrigger 6 is not the minimum and is in [S4]). [S5]

At this time, if the gondola 7 is located at point a shown in FIG. 7, the cam plate 14A has also been rotated by that amount. At this time, the limit switch 14B faces the semi-small circular cam surface 14b and does not operate. Therefore, since the boom 2 is in the left side area (S6), the right side switch 17R of the left and right area changeover switch means 17 is turned off based on the operation of the boom left and right position detection means I4 [S6].
7], the charge switch 17L is turned on. Therefore, current flows only through the transmission circuit 17A among the transmission circuits 17A to 17C. The signal is the safe area judgment drive command means 2
0 is input to the moment limiter which is the turning circle selection unit 21, and the circle in which the turning circle can be turned is selected as the turning small circle Z (see FIG. 4(a)) and stored [S8]. Subsequently, the extension amount and the luffing angle of the boom 2 are detected by the boom extension amount detection means 11.
and detected by the boom heave angle detection means 12 [S
9], the signal is input to the safe area determination section 23. Therefore, it is determined whether the gondola 7 is located within the small turning circle Z (SIO). Since the gondola 7 is located at point a shown in FIG. 4(a) and within the small turning circle Z, the drive power supply unit 24 uses the command signal from the safety area determination unit 23 to control the solenoid drive circuit 45.52. Supply power (Sli). The solenoid 5OL3 of the third solenoid valve 44 is energized [S12
], the third solenoid valve 44 closes the drain circuit 46 (see FIG. 3) (S13). At the same time, the first solenoid valve 38A
The solenoid 5OLI of the second solenoid valve 38B and the solenoid 5OL2 of the second solenoid valve 38B are also energized (S14), and the first solenoid valve 38A
And the second solenoid valve 38B opens the supply/discharge circuit 34.35 [
S15]. As a result, the telescopic cylinder 3 and the undulating cylinder 4
C316) can be extended and raised by operating the levers of the hydraulic switching valves 8S, 8T or 9S, 9T, and can be turned left and right by operating the levers of the hydraulic switching valves 8U or 9U. There, a worker went to gondola 7.
In order to displace the boom 2 to a desired position, the boom 2 is extended and contracted, raised and lowered, and rotated as shown by the arrow (S17).

Each time the boom 2 moves, the boom extension amount detection means 11 and the boom heave angle detection means 12 continue to detect the extension amount and the heave angle. If you wish to continue working at heights [818], step 6
will be returned to.

When the boom 2 located within the small turning circle Z is extended and laid down and is displaced to point C, in step 10, the safe area determination unit 23 determines that it is outside the small turning circle Z, and the safe area determination drive is performed. Power supply from the drive power supply unit 24 of the command means 20 to the solenoid drive circuits 45 and 52 is stopped.

As a result, the solenoid 5QL3 of the third solenoid valve 44 is closed (S19), and the third solenoid valve 44 opens the drain circuit 46 (520).

In this case, even if the operator operates the hydraulic switching valves 8S, 8T or 9S, 9T, the oil is not supplied to the extension side oil chamber 3a of the telescopic cylinder 3 or the tilting side oil chamber 4a of the luffing cylinder 4. The hydraulic oil is returned to the tank 51, and the extension and lowering operations of the boom 2 that would cause the gondola 7 to further move out of the small turning circle Z are regulated [S21]. Since the hydraulic oil supplied to the contraction side oil chamber 3b of the telescopic cylinder 3 and the upright side oil chamber 4b of the undulation cylinder 4 is not returned to the tank 51, the gondola 7 is rotated in a small circle as shown by the arrow d. In order to return to Z,
The boom 2 is retracted or raised (S22).

When the gondola 7 is returned to the small turning circle Z, the process is returned to step 6, and the telescopic and undulating operations are again possible in the same manner as shown by the arrow C317).

When finishing the high-place work in step 18, the boom 2 is contracted, laid down, and rotated in order to return the gondola 7 to the home position [the position of the gondola 7 shown in FIG. 4(a)] (S23). [S24] When the gondola 7 is returned to the home position, the operation is stopped.

On the other hand, when the gondola 7 is located at point e [S6], the boom 2 is located in the right side area, so the limit switch 14B of the left/right area changeover switch means 14 comes into contact with the semi-large circular cam surface 14a and operates, and the charge switch is activated. 17L is turned off (S
25), the right switch 17R is turned on. therefore,
Transfer circuit 17A.

A current flows through 17B, and the turning circle selection section 2 selects the turning center Y as the circle that can be turned [S26]. When the extension amount and the heave angle of the boom 2 are detected [S27] and it is determined that the boom 2 is located within the turning center Y [528], steps 29 to 34 are performed from the above-mentioned stay knobs 11 to 1.
6, and move the gondola 7 to the desired position (the boom 2 can be extended and contracted, raised and lowered, and rotated [S35, see arrow r]). If you wish to continue working at heights, move the gondola 7 to the desired position.
336), and if the boom 2 is in the right-hand region like point g (337), the process can be returned to step 27 and displaced in the same manner as indicated by the arrow f in step 35.On the other hand,
To end the work at height (S36), step 3
8.39 and is operated in the same manner as in step 23.24.

In step 37 above, if the gondola 7 moves to the left side area and is at the light point, the limit switch 14B
is not operating facing the semi-small circular cam surface 14b, and the right switch 17R is turned off (340). Therefore, the small turning circle 2 is selected in the turning circle selection section 21 (S4
1). The extension amount and heave angle of the boom 2 at that time are detected (S42), and the signals thereof are input to the safety area determination section 23. Since gondola 7 is within the small turning circle Z, [S
43], return to step 11, and can be displaced in the same manner as indicated by the arrow I'517).

By the way, if the gondola 7 is outside the small turning circle Z in step 43, for example, if it has been displaced to point i, it is no longer located in the safe area, so the safe area determination drive command means 2
Solenoid drive times from 0! No power is supplied to i45.52, the third solenoid valve 44 opens the drain circuit 46, and the first solenoid valve 38A and the second solenoid valve 38B also close the supply/discharge circuit 34.35. However, since the boom 2 has turned to the right as indicated by the arrow j and reached the point i, the hydraulic oil flows from the high-pressure supply/discharge circuit 34 through the oil passage 33a to the second cylinder of the double-acting cylinder 27. 1 oil chamber 27a.

Therefore, the piston 28 is moving to the right as shown in FIG. 5, and it is detected that the swing motor 5 is turning right (S44).The piston rod 29 opens the contact 32B and closes the contact 32A state, set circuit 3
1A is applied. The center relay coil STI is excited (S45), and the switch rlL of the circuit 40A and the switch rlR of the set circuit 31B are opened (S46).

As a result, the solenoid 5OLI of the first electromagnetic valve 38A is demagnetized without being supplied with power from the circuit 40A (S47), and the first solenoid valve 38A is demagnetized (S47).
The solenoid valve 38A closes the supply/discharge circuit 34 [S48]. On the other hand, since the setting relay coil ST2 is not excited by the open switch rlR, the circuit 40B
The switch r2R is closed, through which the solenoid 5QL2 is directly energized by the power supply. therefore,
Since the second solenoid valve 38B keeps the supply/discharge circuit 35 open, the boom 2 can only turn to the left (S4
9).

In this state, the operator operates the hydraulic switching valve 8U.

Even if I tried to continue turning boom 2 to the right by operating 9U,
The hydraulic oil is blocked by the check valve 42, and the rightward rotation operation of the rotation motor 5 is restricted. Therefore, the operator operates the lever in the opposite direction, causes the hydraulic oil to flow through the second solenoid valve 38B of the supply/discharge circuit 35, the u-turn motor 5, and the check valve 42, and turns the boom 2 to the left as shown by the arrow. (350), the gondola 7 is returned to the area to the right of point β [S51], and by following steps 25 to 34, the boom 2 can be extended, contracted, raised and turned in the same manner as the arrow f (S35).

On the other hand, if the gondola 7 has been displaced to the point m, it is determined in step 43 that it is outside the small turning circle Z in the same way as above, and furthermore, the movement up to that point is a left turn as indicated by the arrow n. Since the piston rod 29 is connected to the contact point 32,
B is closed and the contact 32A is open, and the cent circuit 31B is energized. Set relay coil ST2
is excited [S52], and thereafter the steps 46 to 48 described above are performed.
Following steps 53 to 55 similar to the above, the boom 2 becomes in a state where only the right turn is possible (S56). Therefore, the operator operates the lever in the opposite direction to allow the hydraulic oil to flow through the first electromagnetic valve 38A of the supply/discharge circuit 35, the swing motor 5, and the check valve 43, thereby turning the swing motor 5 to the right (S57). When the gondola 7 is returned to point p, for example, as indicated by arrow 0, the boom 2 will be located in the right side area [S51], so the process returns to step 25 and becomes movable as indicated by arrow f (S35).
).

Note that when the boom 2 located within the turning center circle Y is extended and laid down and displaced to point q, it is determined in step 28 that it is outside the turning center Y, and the step 1 described above is performed.
9 to 20, the extension and overturning operation of the boom 2 that would cause the gondola 7 to further move out of the turning center Y is regulated (S
21). As shown by the arrow r, the boom 2 is contracted or raised (322) in order to return to the circle Y during the turn, and the gondola 7
When it is returned to the turning circle Y, it can be displaced in the same manner as the arrow f by following steps 6 and 25 to 34 (S35).

As can be seen from the above explanation of the operation, when the outrigger 6 extends a small amount on the left side and medium on the right side, when the boom 2 is located in the left side area, it is located within the small turning circle Z and in the right side area. When the gondola 7 is freely displaced within the turning circle Y,
Able to work efficiently at heights. It goes without saying that there is no problem in entering the small turning circle Z in the right side area. Furthermore, on either the left or right side, when the outrigger 6 is extended in large and medium amounts, or large and small, the gondola 7 is displaced in the same manner as in the above-mentioned small and medium cases.

Next, the outrigger 6 should be extended to the same amount on the left and right sides [Fig. 4 (
b)] will be explained below. For example, when the outriggers 6 are extended to the maximum amount on the left and right sides, the limit switches 13a-130, which are the left outrigger extension amount detection means 13L and the right outrigger extension amount detection means 13R [see FIG. 5] 13c operates, and the left outrigger extended position is detected [S1] and the right outrigger extended position is detected [S2]. Then, the detection signal is input to the outrigger extension position determining means 16.

In the outrigger extension position determining means 16, the left outrigger extension amount is not the minimum [S3], and furthermore, it is in the middle [S3].
S58], and is determined to be large [S59]. On the other hand, it is determined that the right outrigger extension amount is also large (S60).

When the gondola 7 is located at the point S shown in FIG. 4(b), the extension amount and the heave angle of the boom 2 are detected by the boom extension amount detection means 11 and the boom heave angle detection means 12 [S61]. The signal is input to the safe area determination section 23.

Therefore, it is determined whether the gondola 7 is located within the great turning circle X (S62). In this case, when the gondola 7 is on either the left or right side, the left and right area changeover switch means 17
Regardless of the operation, the turning circle selection section 21 always selects a turning great circle. Since the point S is within the turning great circle X, the drive power supply section 24 supplies power to the solenoid drive circuits 45 and 52 in response to the command signal from the safety area determination section 23 (S63). From then on, follow steps 64 to 68 in the same manner as steps 12 to 16 above, and set the boom 2.
can extend, contract, undulate, and rotate (S 6B)
. Therefore, if the operator displaces the gondola 7 to a desired position [S69], it can be moved as indicated by the arrow t.

When continuing work at height [S70], step 61
Return to

Note that when the boom 2 is extended and laid down and displaced to point U, it is determined in step 62 that it is outside the turning great circle X, and the power supply from the drive power supply unit 24 to the solenoid drive circuit 45. will be stopped. As a result, steps 71 to 73 are followed in the same way as steps 19 to 21, and the boom 2 is reduced or raised in order to return the gondola 7 to the great turning circle X as shown by the arrow V (S74
). Incidentally, when the boom 2 is displaced to the point U, either the switch rlL or r2R is not energized, and furthermore, the safe area determination drive command means 20 no longer supplies power to the solenoid drive circuit 52. However, transfer circuit 1
Since power is supplied from 7C through the circuit 53, the solenoid 5OLI and the solenoid 5OL2 are excited at the same time, so that it is possible to turn even outside the great turning circle X. Finally, to end the high-place work [S70], the boom 2 may be retracted, laid down, and rotated (376) in order to return the gondola 7 to its home position (S75).

Next, the second invention will be explained with reference to FIG.

As shown in the configuration diagram, the safety devices are similar to the above invention: boom extension amount detection means 11, boom luffing angle detection means 12, right outrigger extension amount detection means 13R1, left outrigger extension amount detection means 13L, boom Left and right position detection means 14
, an outrigger extension position determining means 16, a left/right region switching means 17, a turning direction detecting means 26, a boom turning forward direction regulating means 36, and a safety area determining drive command means 20 having a slightly different configuration from the above, and a boom front and rear control means 20.・
It has a lateral position detection means 18 and a front/rear/lateral region switching means 19. Note that the same parts as the first invention are denoted by the same reference numerals in the drawings and the explanation thereof will be omitted.

The boom longitudinal/lateral position detection means 18 detects the rotational position of the boom 2 in two parts: longitudinal and lateral.
Cam plate 1 shown in Fig. 8 attached to the bottom surface of [see figure]
8A and a limit switch 18B. Cam plate 18
A is disc-shaped, but the vertical line of the car body is 1 m (see Figure 11).
On the other hand, cams 18a and 18b in the form of fan-shaped protrusions are formed in the front and rear regions separated by an angle of, for example, 15 degrees to the left and right, and the lateral regions of 150 degrees are each shaped like an arc. Since the limit switch 18B is attached to the vehicle body, it operates only while the cam plate 18A rotates and contacts the cams 18a and 18b, and does not operate unless the cam plate 18A is in contact with the cams 18a and 18b. Therefore, it is easily determined whether or not the boom 2 is in the front and rear regions.

The front/rear/lateral area changeover switch means 19 is the limit switch 18B of the boom front/rear/lateral position detection means 18 described above.
This is a switch device that switches depending on the operation of the switch. This consists of a rotatable switch lever 19a (see FIG. 8) and two contacts PR and S.

Then, when the boom 2 is in the front and back region, the switch lever 19a enters the contact FR, the contact S is released, and the reset circuit 4 (described later) is powered from the power via the main switch 30.
1 is supplied with power, and when the boom 2 is in the side area and enters the contact S, power is supplied to the cent circuit 31.

The safe area determination drive command means 20 receives signals from the boom extension amount detection means 11 and the boom heave angle detection means 12,
Based on the signals output by the operation of the front/rear/lateral area changeover switch means 19 and the operation of the left/right area changeover switch means 17, it is determined whether or not the boom 2 is located in the safe area, and when the boom 2 is located in the safe area. It outputs a command signal that enables the boom 2 to extend and contract, raise and lower, and rotate. This includes a turning circle selection section 21, a turning circle expansion section 22, a safety area determination section 23, and a drive power supply section 24.

The turning circle selection section 21 is configured to receive a signal from the turning circle expansion section 22.
2, the turning circle selected by the turning circle selection section 21 is the turning circle Z
Alternatively, if the boom 2 is in the front and rear regions in the case of mid-turn Y, the turning circle selected in the turning circle selection section 21 is replaced with the turning great circle X. In this example, the transmission circuit 17
Current is caused to flow through B and 17C. Note that even if the selected turning circle is a large turning circle, the boom 2
is in the front and rear regions, the transmission circuit 17 is sent to the turning circle selection section 21.
Although current is passed through B and 17C, the signal is only duplicated with the signal from the outrigger extended position determination means 16 and does not cause any change in the selected turning great circle. Incidentally, when the contact S is connected, no current flows through the turning circle expansion signal transmission circuit 25, and the small turning circle or mid-turning circle selected by the turning circle selection section 21 is maintained.

The turning direction detecting means 26 has the same structure as described above, but differs in that it detects the turning direction of the boom 2 after the front/rear/side area changeover switch means 19 is operated.

That is, it functions only when the switch lever 19a in the front/rear/lateral area changeover switch means 19 enters the contact S and the contact FR is opened.

A safety device with such a configuration operates as follows. The description will be made with reference to the flowcharts in FIGS. 9(a) to 9(g).

As shown in FIG. 10, for example, it is assumed that the outrigger 6 has a minimum amount of protrusion on the left side and a medium amount of protrusion on the right side. The respective extension amounts are detected by the left outrigger extension amount detection means 13L and the right outrigger extension amount detection means 13R (SIOl, 102). The detection signal is input to the outrigger extension position determining means 16, and it is determined that the left outrigger extension amount is the minimum (S103), and the right outrigger extension amount is determined to be medium (S104.1).
05).

At this time, if the gondola 7 is located at point A shown in FIG. 10, the boom lateral position detection means 14 consisting of the cam plate 14A (see FIG. 8) and the limit switch 14B determines that the boom 2 is in the left area. It is determined (S106
). The right side switch 17R of the left and right area changeover switch of the left and right area changeover switch means 14 is turned off (S107),
A small turning circle Z is selected in the turning circle selection section 21 (S10
8). Subsequently, whether the boom 2 located at point A is in the front-back area or the side area is determined by the boom front-back/side position detection means 1.
8. Since the boom 2 is located in the side area, the limit switch 18B is connected to the cam 18 of the cam plate 18A.
It is determined that the boom 2 is not in the front and rear regions by contacting the arc that deviates from a and 18b (S109). At this time, the switch lever 19a of the front/rear/lateral area changeover switch means 19 enters the contact S [5llO], and the set circuit 31
Power is supplied to the

Subsequently, the extension amount and luffing angle of the boom 2 are detected by the boom extension amount detecting means 11 and the boom luffing angle detecting means 12 [5111], and the signals thereof are inputted to the safety area determining section 23. Therefore, it is determined whether the gondola 7 is located within the small turning circle Z [S112]. Since the gondola 7 is located at point A and within the small turning circle Z, the drive power supply section 24 supplies power to the solenoid drive circuits 45 and 52 in response to the command signal from the safety area determination section 23 (S113).

The subsequent operations follow steps 114 to 118 and are similar to steps 11 to 16 described above (see FIG. 6(b)), in which the operator moves the boom 2 with the arrow in order to displace the gondola 7 to the desired position. It can be expanded and contracted, undulated, and rotated like a mouth (S119).

When the gondola 7 is displaced, the boom extension amount detection means 11 and the boom heave angle detection means 12 continue to detect the extension amount and the heave angle every time the boom 2 moves, but at the same time, the boom longitudinal and lateral position detection means 18 The limit switch 18B, which is operated by the rotation of the cam plate 18A, detects whether the boom 2 is located in the front or rear or the side (S12
0). Then, when the boom 2 located on the side is extended and laid down and displaced to a point, in step 112, the safe area determination unit 23 determines that it is outside the small turning circle Z, and the boom 2 is Since the boom 2 is not located in the front and rear regions, the turning circle selection unit 21 maintains the small turning circle Z and determines that the boom 2 is unsafe. The power supply from the drive power supply unit 24 of the safe area determination drive command means 20 to the solenoid drive circuit 45.52 is stopped, and steps 121 to 12
3 and follow steps 19 to 21 described above [Fig. 6 (b)
)], the gondola 7 further turns around in a small circle Z.
Extending the boom 2 to the outside and lowering the boom 2 are restricted. The boom 2 may be reduced or raised in order to return to the small turning circle Z as shown by arrow 2 (S124). When the gondola 7 is returned to the small turning circle Z, the telescopic and undulating operations are again possible. (S11B).If the boom 2 is located in the front and back area (S120) and work at high places is not to be continued (S11B).
125), to return gondola 7 to its home position (
S126), the boom 2 is retracted, laid down, and rotated (
S127).

When continuing high-place work (S125), when the gondola 7 turns as shown by the arrow H and enters the front and back area, the limit switch 18B hits the cam 18a or 18b and operates, and the front/back/side area changeover switch means 19 The switch lever 19a enters the contact FR (3128). As a result, current flows through the turning circle expansion signal transmission circuit 25 via the contact FR [:5129], and the transmission circuits 17B and 17C
By energizing, the turning circle selection unit 21 replaces the selected left turning small circle Z with the turning large circle X (S13
2). Furthermore, by connecting the contact FR in step 128, the reset relay coils R5Tl and RST2 are excited [5130], and the switches rlR and rl are energized [5130].
L, r2R, and r2L are connected (S131). This is because in step 120 described above, the switch lever 19a of the front/rear/side area changeover switch means 19 is moved to the contact point S.
If it is, one of the switches rlR, rlL, r2R, r2L is far apart, as described later, so
This is to return it to the energized state and maintain it in an initial state in which it will perform its normal operation when the switch lever 19a enters the contact point S. In the current operation, there is nothing directly related to that operation.

The extension amount and undulation angle of the boom 2 when the gondola 7 is located at the point are detected (S133), and the safe area determination unit 2
3, it is determined that it is within the turning great circle X (S1
34), the drive power supply section 24 is connected to the solenoid drive circuit 4
5.52 (S135). From then on,
Follow steps 136-140 and step 1 as described above.
13 to 118, the gondola 7 can be displaced as shown by the arrow T [5141]. If the gondola 7 is located at the point due to such a displacement, it is in the front and back area (3142), so if you want to continue working at a higher altitude [5143], return to step 133 and displace it in the same way as indicated by arrow T. (S141). on the other hand,
If the high-place work is not to be continued (S143), steps 143-145 are followed, and the boom 2 is contracted, laid down, and rotated (S145) in the same manner as in steps 126-127.

By the way, when the gondola 7 is at the point in step 134, steps 146 to 14B are followed, and the boom 2 is retracted or raised so that the gondola 7 returns to the turning great circle X in the same manner as in steps 121 to 123. (S149). If the gondola 7 is displaced as indicated by arrow N and returned to the turning great circle X [S134], it can be displaced in the same manner as indicated by arrow G (S141). By the way, when gondola 7 is in the side area, switch rl
Either L or r2R is not energized, and furthermore, the safe area determination drive command means 20 no longer supplies power to the solenoid drive circuit 52. However, the transmission circuit 17C
Since power is supplied from the motor through the circuit 53, the solenoid 5OLI and the solenoid 5QL2 are excited at the same time, making it possible to turn even outside the great turning circle X.

Now, in step 142, when the gondola 7 turns to the left as shown by the arrow wo and enters the lateral region, the limit switch 18B is disengaged from the cam 18a, etc., and the switch lever 19a of the front/rear/lateral region switching means 19 is moved. enters the contact point S (S150).As a result, the power supply to the turning circle expansion signal transmission circuit 25 is stopped (S151), and it is further determined whether the boom 2 is in the left side area (S15).
2). Since the dot light is located in the left side area, the useful switch 17R of the left/right area changeover switch means 17 is turned off and the left side switch 17L is turned on (S153). Current flows only through the transmission circuit 17A, and the turning circle changes. The large turning circle Determined [5156].Safe area determination drive command means 20
The solenoid drive circuit 45.52 is not supplied with power, the third solenoid valve 44 opens the drain circuit 46, and the first solenoid valve 38
A and the second solenoid valve 38B also close the supply/discharge circuit 34.35. Since the boom 2 was turning to the left, hydraulic oil was introduced into the second oil chamber 27b of the double-acting cylinder 27 from the high-pressure supply/discharge circuit 35 through the oil passage 33b. Therefore, it is detected that the piston 28 has moved to the left in FIG. 8 (opposite to the illustration), and that the swing motor 5 has turned to the left (S 157 ). Thereafter, steps 158 to 163 are performed in the same way as steps 52 to 57 (see FIG. 6(C)) described above, and the operator operates the lever in the reverse direction to return to the front and rear regions as indicated by arrow W. If it is in the right direction (S164), the process returns to step 12B, the contact PR is turned on by the front/back/side area changeover switch means 19, and as long as it is within the front/back area, the boom 2 is extended/contracted/raised/swiveled in the same manner as the arrow T at step 141. The following actions can be performed. At this time, in step 130, the reset relay coil R3T1. RST2 is excited [51
30], switches rlR, rlL, r2R.

r2L is connected (S 131 ). Therefore, the switches rlR and rlL, which were open when the switch lever 19a entered the contact S, are closed. Thereafter, preparations are made so that when the switch lever 19a enters the contact S, the operation will not be hindered. Note that, in step 156, if the point is within the small turning circle Z as indicated by point A, the process returns to step 113 and can be displaced in the same manner as the arrowhead (S119).

On the other hand, when the gondola 7 turns to the right as indicated by the arrow and moves to the opposite direction, it is determined in step 142 that the gondola 7 is not in the front and rear regions, and thereafter steps 150 to 152 are performed.
Furthermore, steps 165 to 168, steps 157, and steps 169 to 174 are followed to return to the front and rear regions as indicated by the arrow. Note that, in step 166, the rotation is returned to mid-day Y, which is different from the above case. Steps 169-174 are steps 45-50 (sixth
(See Figure (C))].

On the other hand, when the gondola 7 is located at the point, the boom 2 is in the right side area (3106), so the left side switch 17L of the left/right area changeover switch means 17 is turned off and the useful switch 17R is turned on [5175], Transfer circuit 17
Current flows to A and 17B, and the circle that can be turned is selected by the turning circle selection unit 21 as the turning middle day Y (S176), the gondola 7 is in the front and rear regions (S177), and the limit switch 14B is set as a semi-great circle. It operates through contact with the cam surface 14a,
Following steps 128 to 140, the boom 2 can be extended and contracted, raised and turned, and rotated in the same manner as in the above-mentioned arrows (S141). If the boom 2 is in the dotted position, it is determined that the boom 2 is in the side area [5177], steps 178 to 185 are followed in the same way as steps 113 to 118, and the gondola 7 is moved as indicated by the arrow. (3186). Now, if you deviate from the turning point Y (S179), step 188~
190, the gondola 7 is returned to the outside of the turning great circle

Note that when the gondola 7 enters the front and rear regions (3187) and stops high-altitude work (S192), it returns to the home position following steps 193-194. If the work at height is to be continued (S192), the process returns to step 128, and thereafter the gondola 7 can be displaced in the same manner as in the arrow (3141). Further, in step 168, if the gondola 7 is located at the point, it is determined that the gondola 7 is within the turning midday Y, and thereafter steps 180 to 185
can be displaced in the same way as the arrow (S
186).

As can be seen from the above explanation of the operation, even if the outrigger 6 has a small extension on the left side and a medium extension on the right side, if the boom 2 is in the front-rear area, it can be safely within the extended turning circle X. By freely displacing the gondola 7, high-place work can be carried out efficiently. Furthermore, when in the side area, the gondola 7 can be freely displaced within the small turning circle Z on the left side and within the turning mid-circle Y on the right side. Also, regardless of whether the left or right outrigger 6 has a small or medium protrusion, when the gondola 7 is in the side area, the turning small circle Z or the turning middle day Y
When it is in the front and rear regions, it can be displaced within the great turning circle X. Furthermore, whether the outrigger 6 is extended in a large or medium amount, or large or small, on either the left side or the right side, the gondola 7 can be moved smoothly in the same manner as in the case where the outrigger 6 is small or medium.

Next, a case will be described in which the outriggers have the same maximum extension amount on the left and right sides. In the outrigger extension position determination means 16, the left outrigger extension amount is not the minimum (S103),
Furthermore, it is determined that it is not medium (S195) but large (S196). On the other hand, it is determined that the right outrigger extension amount is large (S197).

Thereafter, steps 198 to 213 are followed in the same way as steps 61 to 76 shown in FIG. 6(d), so that high-place work can be performed.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the safety device of the high-altitude work vehicle of the present invention, Fig. 2
The figure is an external front view of the aerial work vehicle, Figure 3 is an overall schematic diagram of the hydraulic circuit in the aerial work vehicle, Figures 4 (a) and (b) are explanatory diagrams of the displacement of the gondola, and Figure 5 is each electromagnetic An operation signal transmission circuit diagram for operating the valve, FIGS. 6(a) to (d) are flowcharts explaining the operation, FIG. 7 is a configuration diagram of the safety device of the high-altitude work vehicle of the second invention, FIG. 8 is an operating signal transmission circuit diagram for operating each solenoid valve in the second invention,
9(a) to (g) are flowcharts explaining the operation in the second invention, FIG. 10 is an explanatory diagram of the displacement of the boom in the second invention, and FIG. 11 is an explanation of the possible displacement range of the boom in the prior art. It is a diagram. 2.-boom, 6-outrigger, 11.-boom extension amount detection means, 12-boom elevation angle detection means, 13R-right outrigger extension amount detection means, 13L-left outrigger extension amount detection means, 14-boom left and right Position detection means, 16-Outrigger extension position determination means, 17-Left and right area changeover switch means, 18-Boom longitudinal/lateral position detection means, 19.-
Front/back/side area changeover switch means, 20--Safety area determination drive command means, 26-Turning direction detection means, 36-Boom turning forward direction regulating means. Figure 4 (b) 6th opening (C) 6th opening (d) Figure 10 Figure 11

Claims (2)

[Claims] (1) The boom mounted on the vehicle body can freely extend and contract, raise and lower, and turn, and the front and rear ends of the vehicle are equipped with outriggers on both sides that support the vehicle's posture and can extend and contract laterally and towards the ground. A boom extension detection means for detecting the extension amount of the boom, a boom elevation angle detection means for detecting the elevation angle of the boom, and a boom extension detection means for detecting the extension amount of the right outrigger. A right outrigger extension amount detection means, a left outrigger extension amount detection means for detecting the extension amount of the left outrigger, and a signal receiving means from the right outrigger extension amount detection means and the left outrigger extension amount detection means. outrigger extended position determining means for determining each extended position of the left and right outriggers, boom left and right position detecting means for separately detecting the turning position of the boom on the left and right sides, and the outrigger extended position determining means for determining the respective extended positions of the left and right outriggers. In addition to receiving the signal from the left and right area changeover switch means which is switched by the operation of the boom left and right position detection means, and the signals from the boom extension amount detection means and the boom luffing angle detection means, the right and left area changeover switch means is operated. Safety area determination drive command means that determines whether or not the boom is located in the safe area based on the output signal, and outputs a command signal that enables the boom to extend/contract, raise and lower, and rotate when the boom is in the safe area. and a turning direction detecting means for detecting the turning direction of the boom; and a signal from the safe area determination drive command means and the operation of the turning direction detecting means to restrict the forward turning direction of the boom and to control the turning direction of the boom in the opposite direction. A safety device for an aerial work vehicle, characterized in that a boom rotation forward direction regulating means is provided to allow the forward direction of boom rotation. (2) The boom mounted on the vehicle body can freely extend and contract, raise and lower, and turn, and the front and rear ends of the vehicle are equipped with outriggers on both sides that support the vehicle's posture and can extend and contract laterally and towards the ground. A boom extension detection means for detecting the extension amount of the boom, a boom elevation angle detection means for detecting the elevation angle of the boom, and a boom extension detection means for detecting the extension amount of the right outrigger. A right outrigger extension amount detection means, a left outrigger extension amount detection means for detecting the extension amount of the left outrigger, and a signal receiving means from the right outrigger extension amount detection means and the left outrigger extension amount detection means. outrigger extended position determining means for determining each extended position of the left and right outriggers, boom left and right position detecting means for separately detecting the turning position of the boom on the left and right sides, and the outrigger extended position determining means for determining the respective extended positions of the left and right outriggers. a left/right region changeover switch means that receives a signal from the boom and is switched by the operation of the boom left and right position detection means, and a boom longitudinal/lateral position detection means that detects the rotational position of the boom separately in front and back and sideways; The front and back positions are switched by the operation of the boom front and rear and lateral position detection means.
Signals from the side area changeover switch means, the boom extension amount detection means and the boom elevation angle detection means, and the signals output by the operation of the front/rear/side area changeover switch means and the operation of the left/right area changeover switch means. a safe area determination drive command means for determining whether or not the boom is located in the safe area, and outputting a command signal that enables the boom to extend/contract, raise and lower, and rotate when the boom is in the safe area; The forward direction of rotation of the boom is controlled by the operation of the rotation direction detection means for detecting the rotation direction of the boom by the operation of the direction area changeover switch means, the signal from the safety area judgment drive command means, and the operation of the rotation direction detection means. 1. A safety device for an aerial work vehicle, characterized in that a boom rotation forward direction regulating means is provided to permit rotation in the opposite direction.