JPH0694357B2 - Safety equipment for work vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a safety device for an aerial work vehicle, and more particularly, to expansion / contraction and undulation under the amount of outrigger overhang selected according to the work environment. The present invention relates to a safety control device capable of preventing a vehicle body from tipping over by restricting the operation of an actuator for expansion, contraction, undulation, and turning when the tip of a turning boom deviates from a safety area.

[Conventional technology]

As shown in FIG. 2, the aerial work vehicle 1 is equipped with a boom 2 having a gondola 7 attached to the tip thereof.
Or by the lever operation of the operator on the vehicle body side B,
The boom 2 is adapted to expand and contract, rise and fall, and turn in both left and right directions. Due to the operation, the gondola 7 is displaced to a desired position, and the operator of the gondola 7 can perform a required work at a high place. Such operation of the boom 2 is performed by appropriately switching the hydraulic switching valve interposed in the hydraulic circuit. Then, the boom 2 can be expanded, contracted, swung, and swung by the hydraulic oil introduced from the hydraulic pump to the actuators such as the telescopic cylinder 3, the hoisting cylinder 4, and the turning motor 5. Then, laterally and vertically expandable and contractible outriggers 6 are provided at four positions on the front, rear, left and right of the vehicle body, and the vehicle body is supported by the outriggers 6 while the operator in the gondola 7 continues to work. It is like this.

In the schematic plan view of FIG. 11, when the outrigger 6 is greatly extended as shown by the solid line, the gondola 7 is displaced within the turning great circle X in which the boom 2 can be expanded, contracted, raised and lowered, and turned. This is an area, and falls of the vehicle body are avoided. When the outrigger 6 has a medium overhang, it can safely operate in the middle circle Y indicated by the broken line, and when the overhang is small, it operates only within the small circle Z indicated by the two-dot chain line. Can continue. Therefore, in the case of deviating from the turning circle corresponding to the amount of overhang, the boom extension, fall, and in some cases, the turning motion is also automatically regulated, and the boom is contracted or erected to move the gondola once. I am trying to be safe by having to put it back inside. The reason why the safety area is circular is that the gondola safety area detecting device can have a very simple structure such as a copying mechanism.

[Problems to be Solved by the Invention]

By the way, the rectangle formed by the four legs of the outrigger extending laterally of the vehicle body in a plane is not necessarily a square. That is, it is generally a rectangle that is long in the front and back except when the amount of overhang is maximum. As a result, the displacement region of the gondola where the vehicle body does not fall is a region that is long in the front-rear direction according to the overhang amount of the outriggers. However, since the true circle is adopted as the safety area for the above-mentioned reason, the gondola is not allowed to advance even though it is actually safe in the front and rear areas.

This will be described with reference to FIG. By dividing the turning circle at an angle of, for example, 15 degrees to the left and right with respect to the vertical line 1 m of the aerial work vehicle 1, even when the turning middle circle Y or the turning small circle Z is used when the overhang is not the maximum, Rotate great circle X within 30 degrees
The car body does not fall even if it reaches to. However, as described above, since it is regulated by turning circles corresponding to the respective overhanging amounts, it is not possible to advance the gondola to the shaded area beyond the turning circle. If you want to displace the gondola outside the safe area, you have to increase the outrigger overhang or move the vehicle body if the road width is too narrow to change the overhang. However, there is a problem that the efficiency of work at high places is significantly reduced.

In addition, when parking on a narrow road or the like and performing high-altitude work, the overhang amount of the outrigger 6 on the right side in FIG. It is often made small like a dashed line. When the boom 2 is on the right side, the gondola 7 should be able to advance to the circle Y during turning, but considering that the gondola 7 moves to the left side, the safety range of the entire region is restricted to the turning small circle Z. .
Therefore, on the right side, there is a problem that the gondola 7 can be displaced only within a narrow range that leaves a safe area in which it can advance.

By the way, a work safety device capable of enlarging the safe operation area in the front and rear areas of the vehicle body is described in, for example, Japanese Patent Application Laid-Open No. 57-48600. With this device, it is possible to distinguish between the case where the area is expanded and the case where it is not expanded.However, there are several methods for detecting the conventional turning direction of the boom when the boundary is approached. It uses a limit switch and a sensing strip that operates it.

However, since the limit switch is used, it does not directly detect the direction of the flow of hydraulic oil supplied to and discharged from the swing motor, so the movement of the actuator driving the work safety device is directly detected. However, if the limit switch malfunctions or the like occurs, there is a drawback in that ensuring safety is likely to be impaired.

The present invention has been made to solve the above problems,
The purpose is to secure a safe range according to the overhang amount of each outrigger on the right side and the left side of the vehicle body when the right side and left side outriggers are projected differently, and further,
In the front and rear areas of the vehicle body, the safety area can be expanded within a certain angle area, and there are few malfunctions in its control, providing a safety device for aerial work vehicles that can improve work efficiency. It is to be.

[Means for Solving the Problems]

According to the safety device for an aerial work vehicle of the present invention, the boom 2 [see FIG. 2] mounted on the vehicle body can freely extend / contract, undulate, and turn, and laterally on both sides of the front and rear ends of the vehicle body. Also, the present invention is applied to an aerial work vehicle equipped with an outrigger 6 that supports the vehicle body posture and is capable of expanding and contracting toward the ground. The features thereof are shown in the block diagram of FIG. 1 and the second diagram.
Referring to the drawings, boom extension amount detection means 11 for detecting the extension amount of the boom 2, boom hoisting angle detection means 12 for detecting the hoisting angle of the boom 2, and overhang amount of the right outrigger 6 are detected. The right outrigger extension amount detecting means 13R, the left outrigger extension amount detecting means 13L for detecting the extension amount of the left outrigger 6, the right outrigger extension amount detecting means 13R and the left outrigger extension amount detecting means 13L. An outrigger extension position determining means 16 for determining each extension position of the left and right outriggers 6 in response to a signal from the boom, and a boom left and right position detecting means 14 for separately detecting the turning position of the boom 2 on the left side and the right side.
Receives signals from the outrigger bulge position determination means 16 and the left / right area changeover switch means 17 that is switched by the operation of the boom left / right position detection means 14, the signals from the boom extension amount detection means 11 and the boom hoisting angle detection means 12. A command for determining whether or not the boom 2 is located in the safety area based on the signal output by the operation of the left / right area changeover switch means 17 and for enabling the boom 2 to be expanded / contracted / wound / turned when in the safety area. The safety region determination drive command means 20 that outputs a signal and the first oil chamber 27a (see FIG. 5) or the other of the first oil chamber 27a (see FIG. 5) connected to the supply / discharge circuit 34 (see FIG. 3) of one of the swing motors 5 that swings the boom 2 are used. The piston 28 is displaced by the high-pressure oil of the turning motor 5 introduced into the second oil chamber 27b connected to the supply / discharge circuit 35 at that time, and the movement of the piston rod 29 switches the connection / disconnection of the contacts 32A, 32B. The turning direction detection means 26 for detecting the turning direction of the boom 2, the signal from the safety area determination drive command means 20, and the operation of the turning direction detection means 26 restrict the forward direction of the boom 2 and turn in the opposite direction. The boom turning forward direction restricting means 36 for permitting the above is provided.

The features of the second invention will be described with reference to the block diagram of FIG. 7. The boom extension amount detecting means 11, the boom hoisting angle detecting means 12, which constitutes a part of the configuration of the above invention,
In addition to the right outrigger extension amount detection means 13R, the left outrigger extension amount detection means 13L, the outrigger extension position determination means 16, the boom left / right position detection means 14, and the left / right area changeover switch means 17, the turning position of the boom 2 is set back and forth.・ Boom front / rear / side position detecting means 18 which is separately detected to the side, front / rear / side area switching switch means 19 which is switched by the operation of the boom front / rear / side position detecting means 18, and boom extension amount detecting means 11 And whether the boom 2 is located in the safe area in response to the signal from the boom hoisting angle detection means 12 and the signal output by the operation of the front / rear / side area changeover switch means 19 and the operation of the left / right area changeover switch means 17. The safety area determination drive command means 20 for determining whether or not the boom 2 is expanded / contracted / raised / revolved / turned when in the safety area and the turning position of the boom 2 are in the side area. Therefore, when the front / rear / side area changeover switch means 19 is switched, the first oil chamber 27a (see FIG. 3) connected to the one supply / discharge circuit 34 (see FIG. 3) of the swing motor 5 for swinging the boom 2 (see FIG. 3). (See FIG. 8) or the high pressure oil of the turning motor 5 introduced into the second oil chamber 27b connected to the other supply / discharge circuit 35 causes the piston 28 to move.
The contact points 32A, 32 by moving the piston rod 29.
The turning forward direction of the boom 2 is regulated by the turning direction detecting means 26 for switching the turning direction of the boom 2 to detect the turning direction of the boom 2, the signal from the safety area determination drive command means 20 and the operation of the turning direction detecting means 26. In addition, the boom turning forward direction restricting means 36 for allowing the turning in the opposite direction is provided.

[Action]

When the left and right outriggers 6 are projected, the right outriggers are extended amount detecting means 13R and the left outrigger extension amount detecting means 1
The amount of outrigger overhang is detected at 3L, and the detection signal is input to the outrigger overhang position determining means 16 to determine each overhang position of the outrigger 6. The boom left / right position detecting means 14 detects whether the boom 2 is on the left or right side of the vehicle body, and thereby the left / right area changeover switch means 17 is detected.
Of the safety region determination drive command means 20 based on the signal output by the switching operation of 1 and the signal from the outrigger extension position determination means 16.
Selects a safe swing circle when the boom 2 is in the right area or a safe circle when it is in the left area. When the extension amount and the hoisting angle of the boom 2 are detected by the boom extension amount detecting means 11 and the boom hoisting angle detecting means 12, the gondola 7 is detected.
Is in the safe area, and if it is in the safe area, the safe area determination drive command means 20 outputs a command signal so that the boom 2 can be displaced, and enables the boom 2 to be extended, retracted, swung, and turned. . When the gondola 7 deviates from the turning circle to the outer side in the circumferential direction, extension and fall 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 turning and moving from the right side to the left side or from the left side to the right side region, the displacement of the gondola 7 is restricted depending on whether or not it enters the turning circle of the transfer destination. For example, if it does not fall within the allowable turning circle of the transition destination, it is determined by the safety area determination drive command means 20, and the turning direction detecting means 26 detects the turning direction at that time, and the boom turning forward direction regulation is performed. 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 realizes expansion / contraction, undulation, and turning of the boom 2 within a turning circle that is allowed depending on the overhanging amount of the outriggers 6, even if the outrigger 6 overhanging amounts are different.

In the second invention, the following operation is added to the above operation. When the gondola 7 is in the front / rear area, it is detected by the boom front / rear / side position detecting means 18, and the permissible turning circle in the safety area determination drive command means 20 is detected via the front / rear / side area changeover switch means 19. Extends to the permissible turning circle at the maximum outrigger overhang. Therefore, it is possible to displace it while deviating from the permissible turning circle when it is in the lateral region. When deviating from the permissible turning circles in the circumferential direction, the gondola 7 can be displaced to a desired position after returning to the safe area in the same manner as in the above-described invention.

〔The invention's effect〕

The safety device for an aerial work vehicle of the present invention is not limited to the turning circle determined by the position of the outrigger having the smaller overhang amount, even if the outriggers are forced to have different overhang amounts for the left and right sides. On the side where there is a larger amount of outriggers, the gondola can be safely displaced within the turning circle corresponding to the amount of overhang, and work efficiency in aerial work is significantly improved. Then, when the gondola shifts from the right side to the left side, for example, when the turning allowable circle of the shift destination is small, and if the gondola deviates from the safety area by turning as it is, further turning of the gondola is restricted, and in the opposite direction. By turning, the safety of the vehicle body is achieved.

In such an operation, the swinging direction of the boom is reliably detected by using the pressure of the hydraulic oil supplied to and discharged from the swinging motor, and incorrect detection of the swinging direction may occur when a limit switch is used. This is avoided, and the function and operation reliability as a safety device for an aerial work vehicle are improved.

In the second invention, in addition to the effects described above, in the front-rear region of the vehicle body, regardless of the amount of protrusion of the outrigger,
When the amount of overhang is large, it is possible to advance and displace to the area within the turning great circle. Moreover, when the gondola moves from the front-rear region to the lateral region, the turning allowable circle at the transition destination is small. By turning in the direction, the safety of the vehicle body is achieved.

〔Example〕

Hereinafter, the present invention will be described in detail based on examples thereof.
FIG. 2 shows an aerial work vehicle 1 to which the safety device of the present invention is applied.
The boom 2 mounted on the vehicle body can be freely extended, retracted, and swung by the telescopic cylinder 3, the hoisting cylinder 4, and the turning motor 5. Outriggers 6 that support the vehicle body posture are provided on the left and right sides so that the outriggers 6 can extend and contract freely. In addition,
The telescopic cylinder 3, the hoisting cylinder 4, and the swing motor 5 are respectively provided with hydraulic switching valves 8S, 8T, 8U and 9S, 9 shown in the hydraulic circuit of FIG.
It is designed to be operated by lever switching operation of T and 9U.
Although not shown, the hydraulic jack that overhangs the outriggers 6 and lands them is operated by hydraulic oil from the hydraulic pump 10 in the same manner 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 levitation angle detection means 12 for detecting the levitation angle of the boom 2, each of which extends and contracts. This is a known sensor provided near the cylinder 3 and the undulating cylinder 4. The right outrigger bulge amount detecting means 13R and the left outrigger bulge amount detecting means 13L are, for example, three types of outriggers 6 of large, medium and small as shown in two examples of FIGS. 4 (a) and 4 (b). When there is an overhang amount, the overhang amount on the left side and the overhang amount on the right side are detected. Therefore, although not shown in detail, three limit switches 13a, 13b, 13c for detecting the amount of the outrigger 6 moving to the side.
Are provided as shown in FIG.

The boom left / right position detecting means 14 detects the turning position of the boom 2 as
The cam plate 14A and the limit switch 14B shown in FIG. 5 attached to the lower surface of the revolving table 15 (see FIG. 2) that rotates the boom base are separately detected on the left side and the right side.
Consists of. The cam plate 14A has a disk shape, and the vertical line of the vehicle body is 1 m.
A semi-great circle cam surface 14a is formed on the right side and a semi-small circle cam surface 14b is formed on the left side with a straight line 14m coinciding with [see FIG. 11] as a boundary. The limit switch 14B attached to the vehicle body operates only while it is in contact with the semi-great circle cam surface 14a. Therefore, whether the boom 2 is in the left or right area can be easily determined by the operation of the limit switch 14B.

The outrigger bulge position determination means 16 is an outrigger logic (see FIG. 5) that receives signals from the left and right independent outrigger bulge amount detection means 13R and 13L, and the outrigger amount of the left and right outriggers 6 is determined. Is determined to be large / medium / small, and a signal of the determination result is output to the safe area determination drive command means 20 via the left / right area changeover switch means 17 described below. The output form is such that when the amount of overhang of the left outrigger 6 is small, current is passed only to the transmission circuit 17Al, and when the amount of overhang is medium, current is passed to the transmission circuits 17Al and 17B1, and the amount of overhang is large. At this time, a current is passed through the transmission circuits 17Al, 17Bl, 17Cl. Further, when the overhang amount of the right outrigger 6 is small, the current is passed only to the transmission circuit 17Ar, when the overhang amount is medium, the current is passed to the transmission circuits 17Ar and 17Br, and when the overhang amount is large, the transmission circuit 17Ar is transmitted. An electric current is made to flow through 17Ar, 17Br, 17Cr. In addition, each transfer circuit 17Ar and 17Al, 17Br and 17Bl, 17Cr
The 17Cl is connected after the left / right area changeover switch means 17 to form transmission circuits 17A, 17B, 17C.

The left / right area changeover switch means 17 receives the signal from the outrigger extension position determination means 16 and is switched by the operation of the boom left / right position detection means 14, and the transmission circuits 17Al, 17Bl,
Left switch 17 interposed between 17Cl and 17Ar, 17Br, 17Cr
These are L and right switch 17R. Then, the operation of the boom left / right position detecting means 14 is configured such that each switch of the transmission circuits 17Al, 17Bl, 17Cl or each switch of the transmission circuits 17Ar, 17br, 17Cr simultaneously operates.

The safety area determination drive command means 20 is a boom extension amount detection means.
11 and the signal from the boom hoisting angle detection means 12 and the signal output by the operation of the left / right area changeover switch means 17 determine whether or not the boom 2 is in the safety area, and the boom 2 is in the safety area. When the boom 2 expands and contracts, rises and falls,
It outputs a command signal that enables turning. This is composed of a turning circle selection unit 21, a safety area determination unit 23, and a drive power supply unit 24.

The turning circle selection unit 21 includes the above-mentioned three transmission circuits 17A and 17A.
This is a moment limiter that has the function of selecting a turning circle depending on the presence or absence of current from B and 17C. Safety area determination unit
The position 23 of the gondola 7 is selected based on the turning circle signal selected by the turning circle selection unit 21, the boom extension amount detection means 11 and the boom extension / reduction angle signal from the boom hoisting angle detection means 12. It is to determine whether it is within the turning circle, that is, within the safety area. Drive power supply unit 24
In response to the signal from the safety area determination unit 23, the safety signal is output for maintaining the boom 2 to be expanded, contracted, raised, and swung. When the safety area determination unit 23 determines that the safety is not safe, it immediately outputs a signal that restricts the extension and fall-down operation of the boom 2 and also restricts the turning in the previous direction. By the way, the safety area determination unit 23 and the like are microcomputers, which are not shown in the figure, but include a central processing unit, a fixed memory, a write memory, and the like, and can be a compact device. However, it goes without saying that a structure that realizes the same function with a mechanical structure may be used.

The turning direction detecting means 26 detects the turning direction of the boom 2 during turning. This is because the piston 28 in the double-acting cylinder 27 shown in FIG. 5 moves in the left-right direction, and the set circuit 31 is installed opposite to the left-right ends of the piston rod 29.
This is a changeover switch device adapted to change over the connection and disconnection of the contacts 32A, 32B interposed in. The first oil chamber 27a is
The supply / discharge circuit 34 of the turning motor 5 [see FIG. 3] is connected via the oil passage 33a, and the second oil chamber 27b is connected to the supply / discharge circuit 35 via the oil passage 33b. Therefore, when the swing motor 5 is rotating to the right, the supply / discharge circuit 34 has a high pressure, and the first and
The oil chamber 27a also has a high pressure, and the piston rod 29 moves to the right, opening the self-resetting contact 32B, while the other contact 32A.
Keep closed. When the rotation direction of the swing motor 5 is opposite, the contact 32A is opened while the contact 32B is kept closed. With such an operation, the operation of the boom turning forward direction restricting circuit 37 described below can be distinguished by the rotation direction of the turning motor 5.

The boom turning forward direction regulating means 36 uses the signal from the safety region determination drive command means 20 and the operation of the turning direction detecting means 26 to turn the boom 2 in the turning forward direction, that is, in the direction in which the boom 2 has been turned up to now. In addition to restricting, turning in the opposite direction is allowed. This is the boom turning forward regulation circuit 37
And a turning forward direction restricting device 38. The boom turn forward direction regulation circuit 37 includes a keep switch 39A for regulating right turn.
And a keep switch 39B for restricting left turn. The keep switch 39A includes a set relay coil ST1 provided in a set circuit 31A having a contact 32A, a switch r1L interposed in a circuit 40A directly connected to a power source, and a switch r1R interposed in a set circuit 31B having a contact 32B. , And a reset relay coil RST1 provided in the reset circuit 41A. Then, a solenoid drive circuit 52A, which will be described later, is connected to the circuit 40A that interposes the switch r1L, and the solenoid SOL of the first solenoid valve 38A, which is the turning forward direction restricting device 38, is connected thereto.
1 is connected. Further, the keep switch 39B is interposed in the set relay coil ST2 connected in series to the switch r1R of the set circuit 31B, the switch r2L connected in series to the set relay coil ST1, and the circuit 40B directly connected to the power supply. Switch r2R and a reset relay coil RST2 provided in the reset circuit 41B. The solenoid drive circuit 52 is connected to the circuit 40B with the switch r2R interposed.
Second, which is connected to B and is a turning forward regulation device 38
Solenoid SOL2 of solenoid valve 38B is connected. Note that the switches r1L, r1R, r2L, r2R are keep switch contacts, and when the set relay coil ST1 or ST2 is driven, both the switches r1L, r1R or r2L, r2R are opened, but the drive stops. Even so, the open state is maintained. And the reset relay coil RST1 or RS
When T2 is driven, the open switch r1L, r1R or r2L, r2R is restored and the circuit can be energized.
Even if the driving is stopped, the closed state is maintained.

The above-mentioned first solenoid valve 38A and second solenoid valve 38B are interposed in the supply / discharge circuits 34, 35 shown in FIG.
When the OL1 and SOL2 are demagnetized, the supply / discharge circuits 34 and 35 are closed. Since the check valves 42 and 43 are juxtaposed to these solenoid valves, for example, when only the first solenoid valve 38A is closed, the turning motor 5 is prevented from turning right and only turning left is permitted. It has become so.

In addition to the above configuration, a signal from the driving power supply unit 24,
A boom expansion and contraction allowing device that allows the boom 2 to expand and contract, and an elevating and lowering, and a boom expansion and fall restricting device that restricts the expansion and falling by a signal from the safety area determination unit 23 are provided. In this example, these devices are one third solenoid valve 44 interposed in the hydraulic circuit. This third solenoid valve 44
A solenoid SOL3 is provided which is excited by electric power from a solenoid drive circuit 45 which receives a signal from the safety region determination drive command means 20 shown in FIG. This third solenoid valve 44
When the solenoid SOL3 is demagnetized, the drain circuit 46 shown in FIG. 3 is opened, and the hydraulic oil between the extension side oil chamber 3a of the telescopic cylinder 3 and the fall side oil chamber 4a of the undulating cylinder 4 is non-returned. Valve 4
The oil is discharged to the tank 51 from the oil passages 49, 50 with the 7, 48 interposed.
Therefore, in this case, even if the switching valves 8S, 9S or 8T, 9T are operated to supply the hydraulic oil, the hydraulic oil is immediately drained and the boom 2 is neither extended nor fallen down. On the other hand, when the solenoid SOL3 is excited, the oil passages 49, 50 do not communicate with the tank 51, high-pressure hydraulic oil is supplied to the respective oil chambers 3a, 4a, and the boom 2 can be expanded and contracted and raised and lowered. .

By the way, the solenoid drive circuit 45 is connected to a solenoid drive circuit 52 capable of directly exciting the solenoids SOL1 and SOL2 of the first solenoid valve 38A and the second solenoid valve 38B which are the turning forward direction restricting device 38. . This is because the turning direction detecting means 26 is provided even though the safety area determining section 23 of the safety area determining drive command means 20 determines that the vehicle is safe.
This is to prevent the solenoid valve 38A or 38B of one of the turning forward direction restricting devices 38 from always restricting one of the turning directions of the turning motor 5 by the operation of. Therefore, the first solenoid valve 38A and the second solenoid valve 38B also function as a boom turning permission device as shown in FIG. In addition,
Diodes 52a and 52b interposed in the solenoid drive circuit 52
Between the circuit 40A and the solenoid drive circuit 52A,
This is to prevent current from flowing to the solenoid drive circuit 52 when there is a potential difference between the circuit 40B and the solenoid drive circuit 52B.

The safety device for an aerial work vehicle having such a configuration allows the boom to be extended / retracted / revolved / turned on the left side and the right side even if the left and right outriggers 6 have different protrusion amounts as follows. By selecting and operating within the safety area, it is possible to improve the work efficiency of the aerial work vehicle. In addition,
This will be described with reference to the flowcharts of 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. Limit switches 13a to 13c (see FIG. 5) of the left outrigger extension amount detecting means 13L and the right outrigger extension amount detecting means 13R operate to detect the left and right outrigger extension positions [steps in the flowchart. 1 and 2, hereinafter referred to as S1 and the like]. When the amount of protrusion is the smallest of large, medium, and small, only the limit switch 13a operates. When the amount of overhang is medium, the limit switch 13b operates, and when the amount of overhang is large, the limit switch 13c operates, and the signal is input to the outrigger extended position determination means 16. There are various combinations of the left and right overhang amounts, but in the following description, the fourth amount will be described.
As shown in Figure (a), the left outrigger 6 has a small overhang,
The case where the right outrigger 6 has a medium overhang will be described as an example.

The outrigger overhanging position determination means 16 determines that the left outrigger 6 has the smallest overhang [S3], and the right outrigger 6 is not the least overhang and is [S4]. [S5].

At this time, if the gondola 7 is located at the point a shown in FIG. 7, the cam plate 14A is also rotated by that amount. At this time, the limit switch 14B faces the semi-small circle cam surface 14b, and it does not operate. Therefore, boom 2
Is in the left side area [S6], the right switch 17R is turned off among the left and right area changeover switch means 17 based on the operation of the boom left and right position detecting means 14 [S7], and the left switch 17L is turned on. . Therefore, the transmission circuits 17A to 17C
Of these, current flows only in the transmission circuit 17A. The signal is input to the moment limiter, which is the turning circle selection unit 21 of the safety area determination drive commanding means 20, and a turnable circle is selected and stored in the turning small circle Z [see FIG. 4 (a)]. [S8]. Subsequently, the extension amount and the undulation angle of the boom 2 are detected by the boom extension amount detection means 11 and the boom levitation angle detection means 12 [S9], and the signal is input to the safety area determination unit 23. Therefore, it is determined whether the gondola 7 is located within the turning small circle Z [S10]. Gondola 7 is shown in Figure 4 (a).
Since it is located within the turning small circle Z and is located at the point a, the drive power supply unit 24 supplies power to the solenoid drive circuits 45 and 52 by the command signal from the safety area determination unit 23 [S11]. The solenoid SOL3 of the third solenoid valve 44 is excited [S12], and the third solenoid valve 44 closes the drain circuit 46 [see FIG. 3] [S13]. At the same time, the solenoid SOL1 of the first solenoid valve 38A and the solenoid SOL2 of the second solenoid valve 38B are also excited [S14],
The first solenoid valve 38A and the second solenoid valve 38B open the supply / discharge circuits 34, 35 [S15]. As a result, the telescopic cylinder 3 and the hoisting cylinder 4 can be extended and raised by operating the hydraulic switching valves 8S, 8T or 9S, 9T, and the hydraulic switching valve 8U
Or you can turn to the left or right by operating the 9U lever [S16]. Therefore, in order for the operator to displace the gondola 7 to a desired position, the boom 2 is extended, retracted, swung, and swung,
It is displaced as indicated by arrow b [S17]. Each time the boom 2 moves, the boom extension amount detecting means 11 and the boom hoisting angle detecting means 12 continue to detect the extension amount and the hoisting angle. If work at a high place is to be continued [S18], the process returns to step 6.

When the boom 2 located in the turning small circle Z is extended and laid down and displaced to the point c, in step 10, the safety area determining unit 23 determines that it is outside the turning small circle Z, and the safety area determining drive is performed. Power supply from the drive power supply unit 24 of the command means 20 to the solenoid drive circuits 45, 52 is stopped. As a result, the solenoid SOL3 of the third solenoid valve 44 is demagnetized [S19], and the third solenoid SOL3 is demagnetized.
The solenoid valve 44 opens the drain circuit 46 [S20]. In this case, even if the operator operates the hydraulic switching valves 8S, 8T or 9S, 9T, the oil is supplied to the extension side oil chamber 3a of the telescopic cylinder 3 and the fall side oil chamber 4a of the undulating cylinder 4. The hydraulic oil is returned to the tank 51, and the extension and the fall operation of the boom 2 such that the gondola 7 further goes out of the turning small circle Z are restricted [S21]. Since the hydraulic oil supplied to the contraction side oil chamber 3b of the telescopic cylinder 3 or the standing side oil chamber 4b of the undulating cylinder 4 is not returned to the tank 51, the gondola 7 is swung by the small circle Z as shown by the arrow d. Boom 2 is contracted or raised to return it to the inside [S2
2]. When the gondola 7 is returned into the turning small circle Z, it is returned to step 6 and the expansion / contraction / elevation operation can be performed again in the same manner as the arrow b [S17].

When the work at high places is completed in step 18, the boom 2 is contracted to return the gondola 7 to the home position [the position of the gondola 7 shown in FIG. 4 (a)] [S23].
Perform prone / turning operation [S24]. The operation is stopped when the gondola 7 is returned to the home position.

On the other hand, if the gondola 7 is located at the point e [S6], the boom 2
Is located in the right side area, the left and right area changeover switch means 14
The limit switch 14B operates in contact with the semi-great circle cam surface 14a, the left switch 17L is turned off [S25], and the right switch 17R is turned on. Therefore, a current flows through the transmission circuits 17A and 17B, and the turning circle selection unit 21 selects the turning middle circle Y as a turnable circle [S26]. When the extension amount and the undulation angle of the boom 2 are detected [S27] and it is determined that the boom 2 is located within the turning circle Y [S28], steps 29 to 34 are performed thereafter.
In the same manner as steps 11 to 16 described above, the boom 2 can be extended / retracted / raised / rotated so as to displace the gondola 7 to a desired position [S35, see arrow f]. When continuing high-altitude work [S36], boom 2 is at point g.
If it is in the right area [S37] as described above, the process can return to step 27 and be displaced in the same manner as the arrow f in step 35. On the other hand, when finishing work at high places, [S3
6], following steps 38 and 39, the same operation as in steps 23 and 24 is performed.

In step 37 above, if the gondola 7 moves to the left side area and is at point h, the limit switch 14B is not operating facing the semi-small circle cam surface 14b, and the right switch 17R is turned off. [S40]. Therefore, the turning circle selection unit 21
In step S41, the turning small circle Z is selected. The extension amount and the undulation angle of the boom 2 at that time are detected [S42], and the signal is input to the safety area determination unit 23. Since the gondola 7 is within the small turning circle Z [S43], the process returns to step 11 and can be displaced in the same manner as the arrow b [S17].

By the way, in step 43, if the gondola 7 is outside the turning small circle Z, for example, if it is displaced to the point i, it is no longer in the safety area, so the safety area determination drive command means 20 to 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 38A and the second solenoid valve 38A
The solenoid valve 38B also closes the supply / discharge circuits 34, 35. However, since the boom 2 has turned rightward as shown by the arrow j to reach the point i, the hydraulic oil is supplied from the high pressure supply / discharge circuit 34 through the oil passage 33a to the double acting cylinder 27. 1 oil chamber 27a
Has been introduced to. Therefore, the piston 28 is moving rightward as shown in FIG. 5, and it is detected that the turning motor 5 is turning right [S44]. The piston rod 29 opens the contact 32B and closes the contact 32A, and the set circuit 31A is energized. The set relay coil ST1 is excited [S45], and the switch r1L of the circuit 40A and the switch r1R of the set circuit 31B are opened [S46]. As a result, the solenoid SOL1 of the first solenoid valve 38A is demagnetized without being supplied with power from the circuit 40A [S47], and the first solenoid valve 38A closes the supply / discharge circuit 34 [S48]. On the other hand, the set relay coil ST2 is not excited by the open switch r1R, so the circuit 4
The 0B switch r2R is closed through which the solenoid SOL2 is directly energized with the source power. Therefore, the second
Since the solenoid valve 38B keeps the supply / discharge circuit 35 open,
The boom 2 is in a state where it can only turn left [S49].

In such a state, even if the operator operates the hydraulic pressure switching valves 8U and 9U to continue turning the boom 2 to the right, hydraulic oil is blocked by the check valve 42, and the turning motor 5 turns to the right. Is regulated. Therefore, the operator reversely operates the lever to flow the hydraulic oil through the second electromagnetic valve 38B of the supply / discharge circuit 35, the swing motor 5, and the check valve 42, and turn the boom 2 to the left as shown by an arrow k. S5
[0], the gondola 7 is returned to the area on the right side of the point 1 [S51], and the boom 2 can be expanded / contracted / raised / turned similarly to the arrow f by following steps 25 to 34 [S35].

On the other hand, when the gondola 7 is displaced to the point m, it is determined in step 43 that it is outside the turning small circle Z, as described above.
Moreover, since the operation up to that point was a left turn as indicated by the arrow n, the piston rod 29 closes the contact 32B and opens the contact 32A, and the set circuit 31B is energized. The set relay coil ST2 is excited [S5
2), then steps 53 to 5 similar to steps 46 to 48 described above.
Follow 5 and only the right turn of boom 2 will be possible [S
56]. Therefore, the operator reversely operates the lever to cause 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 to rotate the swing motor 5 to the right [S57]. When the gondola 7 is returned to the point p, for example, as indicated by the arrow o, the boom 2 is located in the right side region [S51], and then the process returns to step 25 and can be displaced similarly to the arrow f [S35]. .

When the boom 2 located within the circle Y during turning is extended and laid down and displaced to the point q, in step 28,
It is determined that it is outside the circle Y during turning, and the above-described steps 19 to
The boom 2 is restricted from extending and falling so that the gondola 7 further moves out of the circle Y while turning 20 (S21).
As indicated by the arrow r, the boom 2 is contracted or erected to return to the inside of the turning circle Y [S22], and when the gondola 7 is returned to the inside of the turning circle Y, step 6 and step 25-
You can follow 34 and displace it in the same way as arrow f [S35].

As can be understood from the above description of the operation, when the outrigger 6 has a small protrusion amount on the left side and a middle amount on the right side, when the boom 2 is positioned in the left side region, it is positioned in the right side region within the turning small circle Z. Then freely displace the gondola 7 within the circle Y
Can perform high-altitude work efficiently. Needless to say, it may be possible to enter the turning small circle Z in the right region. Furthermore, the gondola 7 is displaced in the same manner as in the case of the small or medium case described above, regardless of whether the outrigger 6 has a large or medium amount of protrusion or a large or small amount of protrusion on either side.

Next, a case will be described in which the outriggers 6 have the same overhang amount on the left and right sides [see FIG. 4 (b)]. For example, when the outriggers 6 have the maximum overhang amounts on the left and right sides, the limit switches 13a to 13c that are the left outrigger overhang amount detecting means 13L and the right outrigger overhang amount detecting means 13R.
13c of [See FIG. 5] operates to detect the left outrigger extension position [S1] and the right outrigger extension position [S2]. Then, the detection signal is input to the outrigger extension position determination means 16.

In the outrigger bulge position determination means 16, the left outrigger bulge amount is not the minimum [S3], and is not in the middle [S5].
8], it is determined to be large [S59]. On the other hand, it is determined that the right outrigger protrusion amount is also large [S60]. Then, when the gondola 7 is located at the point s shown in FIG. 4 (b), the extension amount and the hoisting angle of the boom 2 are detected by the boom extension amount detecting means 11 and the boom hoisting angle detecting means 12 [S61],
The signal is input to the safety area determination unit 23. Therefore, it is determined whether the gondola 7 is located within the turning great circle X [S62]. In this case, the turning circle selection unit 21 always selects the turning great circle regardless of the operation of the left / right area changeover switch means 17 with the gondola 7 on either side. Since the point s is inside the turning great circle X, the drive power supply unit 24 supplies power to the solenoid drive circuits 45 and 52 by the command signal from the safety area determination unit 23 [S63]. From then on, steps 64 to 68 can be followed in the same manner as steps 12 to 16 described above to extend, retract, raise and lower the boom 2 [S68]. Therefore, if the operator displaces the gondola 7 to a desired position [S69], it can be moved as shown by an arrow t. When continuing work at high places [S70], the process returns to step 61.

When the boom 2 is extended and laid down and displaced to the point u, it is determined in step 62 that it is outside the turning great circle X, and the drive power supply unit 24 causes the solenoid drive circuits 45, 5 to move.
Power supply to 2 is stopped. As a result, steps 71 to 73 are followed in the same manner as steps 19 to 21, and the boom 2 may be contracted or raised so as to return the gondola 7 to the inside of the great turning circle X as indicated by arrow v [S74]. . By the way, when the boom 2 is displaced to the point u, either the switch r1L or r2R is not energized, and the safety region determination drive command means 20 does not supply power to the solenoid drive circuit 52. However, since electric power is supplied from the transmission circuit 17C through the circuit 53, the solenoids SOL1 and SOL2 are excited at the same time, and the turning can be performed even outside the turning great circle X. Finally, if you want to finish the work in high places, click [S7
0], to return the gondola 7 to the home position [S7
5], the boom 2 can be reduced, tilted down, and turned [S7
6].

Next, the second invention will be described with reference to FIG.
As shown in the configuration diagram, the safety device has a boom extension amount detecting means 11 and a boom hoisting angle detecting means 1 as in the above invention.
2, right outrigger extension amount detection means 13R, left outrigger extension amount detection means 13L, boom left and right position detection means 14, outrigger extension position determination means 16, left and right area changeover switch means 17,
In addition to the turning direction detecting means 26 and the boom turning forward direction restricting means 36, the safety area determination drive command means 20, the boom front / rear / side position detecting means 18, and the front / rear / side area changeover switch means having slightly different configurations from those described above are provided. Has 19. Note that the same points as those of the first invention are denoted by the same reference numerals in the drawings, and the description thereof will be omitted.

The boom front / rear / side position detecting means 18 detects the turning position of the boom 2 by dividing it into front / rear and side positions, and detects the turning position of the boom base on the turning table 15 (see FIG. 2). It is composed of a cam plate 18A and a limit switch 18B shown in FIG. Although the cam plate 18A has a disc shape, fan-shaped cams 18a and 18b are formed in the front and rear regions which are separated from each other by an angle of, for example, 15 degrees to the left and right with respect to the vertical line 1 m of the vehicle body (see FIG. 11). It is formed, and each of the lateral 150 degree regions has an arc shape. Since the limit switch 18B is attached to the vehicle body, the limit switch 18B operates only while the cam plate 18A rotates and is in contact with the cams 18a and 18b, and does not operate unless the contact occurs. Therefore, boom 2
It is easily determined whether or not is in the front-back area.

The front / rear / side area changeover switch means 19 is a switch device that is switched by the operation of the limit switch 18B of the boom front / rear / side position detecting means 18 described above. This is composed of a rotatable switch lever 19a (see FIG. 8) and two contacts FR, S. Then, when the boom 2 is in the front and rear area, the switch lever 19a enters the contact FR and the contact S is released,
Electric power is supplied from a power source via the main switch 30 to a reset circuit 41, which will be described later, and when the boom 2 is in a lateral area and enters a contact S, electric power is supplied to the set circuit 31.

The safety area determination drive command means 20 is a boom extension amount detection means.
11 and the signal from the boom hoisting angle detection means 12,
Receiving a signal output by the operation of the side area changeover switch means 19 and the operation of the left and right area changeover switch means 17,
It is determined whether or not the boom 2 is located in the safety area, and when it is in the safety area, a command signal is output that enables the boom 2 to be expanded, contracted, raised, and swung. This is composed of a turning circle selection unit 21, a turning circle expansion unit 22, a safety area determination unit 23, and a drive power supply unit 24.

A signal from the turning circle expanding unit 22 is input to the turning circle selecting unit 21, and the turning circle expanding unit 22 turns the turning circle selected by the turning circle selecting unit 21 into a turning small circle Z. Alternatively, when the boom 2 is in the front-rear area in the case of the middle circle Y, the circle circle selected in the circle selector 21 is replaced with the circle great circle X. In this example, a current is supplied to the transmission circuits 17B and 17C via the turning circle extension signal transmission circuit 25 connected to the contact point FR of the front / rear / side area changeover switch means 19. Even when the selected turning circle is the turning great circle, if the boom 2 is in the front-rear region, a current is sent to the turning circle selection unit 21 via the transmission circuits 17B and 17C, but the signal is outriggered. Only the signal from the exit position determination means 16 is duplicated, and the selected turning great circle is not changed. By the way, when the contact S is connected, no current flows through the turning circle extension signal transmission circuit 25, and the turning small circle or the turning middle circle selected by the turning circle selection unit 21 is maintained.

The turning direction detecting means 26 has the same structure as that described above, but differs in that the turning direction of the boom 2 is detected after the operation of the front / rear / side area changeover switch means 19. That is, the switch lever 19a of the front / rear / side area changeover switch means 19 functions only when the contact S enters and the contact FR is opened.

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

As shown in FIG. 10, it is assumed that the outrigger 6 has a minimum overhang on the left side and a middle overhang on the right side. The left outrigger extension amount detecting means 13L and the right outrigger extension amount detecting means 13R detect the respective extension amounts [S101, 102]. The detection signal is input to the outrigger extension position determination means 16, and it is determined that the left outrigger extension amount is the minimum [S103] and the right outrigger extension amount is medium [S104, 105].

At this time, assuming that the gondola 7 is located at the point a shown in FIG. 10, the cam plate 14A (see FIG. 8) and the limit switch 1
The boom left / right position detecting means 14 composed of 4B determines that the boom 2 is in the left side region [S106]. The right switch 17R of the left / right area changeover switch of the left / right area changeover switch means 14 is turned off [S107], and the turning circle selection unit 21 selects the turning small circle Z [S108]. Next, whether the boom 2 located at point a is the front-rear region or the side region
It is detected by the lateral position detecting means 18. Since the boom 2 is located in the lateral area, the limit switch 18B moves to the cam plate 18A.
It is determined that the boom 2 is not in the front-rear region by contacting the circular arc that has deviated from the cams 18a and 18b of [S109]. At this time, the switch lever 19a of the front / rear / side area changeover switch means 19 enters the contact S [S110], and power is supplied to the set circuit 31.

Subsequently, the extension amount and the hoisting angle of the boom 2 are detected by the boom hoisting amount detecting means 11 and the boom hoisting angle detecting means 12 [S111], and the signal thereof is input to the safety area determination part 23.
Therefore, it is determined whether the gondola 7 is located within the turning small circle Z [S112]. Since the gondola 7 is located at the point a and is within the turning small circle Z, the drive power supply unit 24 supplies power to the solenoid drive circuits 45 and 52 by the command signal from the safety region determination unit 23 [S113]. Subsequent operations follow steps 114 to 118, and the above steps 11 to 16 [see FIG. 6 (b)].
Similar to the above, in order for the operator to displace the gondola 7 to a desired position, the boom 2 is expanded / contracted / raised / reduced as indicated by arrow B.
It can be turned [S119].

When the gondola 7 is displaced, the boom extension amount detection means 11 and the boom hoisting angle detection means 12 continue to detect the extension amount and the hoisting angle each time the boom 2 moves. The limit switch 18B, which is operated by the rotation of the cam plate 18A, detects whether the boom 2 is positioned in the front-rear direction or the side direction [S120]. And
When the boom 2 located on the side is extended and laid down and displaced to the point C, the safety area determination unit 23 determines in step 112 that the boom 2 is outside the turning small circle Z, and the boom 2 is in the front-rear area. Turning circle selection unit 21
Then, the turning small circle Z is maintained, and it is determined that the boom 2 is not safe. The power supply from the drive power supply unit 24 of the safety region determination drive command means 20 to the solenoid drive circuits 45, 52 is stopped, the steps 121 to 123 are followed, and the above step 19 to
In the same manner as 21 [see FIG. 6 (b)], extension and fall operation of the boom 2 such that the gondola 7 is further out of the turning small circle Z are restricted. The boom 2 may be contracted or erected in order to return it to the turning small circle Z as shown by the arrow D [S12
Four〕. When the gondola 7 is returned to the turning circle Z, it expands and contracts.
The undulating operation is possible again [S118]. The boom 2 is located in the front-rear area [S120], and when the work at high places is not continued [S125], the boom 2 is contracted / tilted / turned to return the gondola 7 to the home position [S126]. [S1
27].

When continuing work at high altitudes [S125], if the gondola 7 turns into the front-rear area as shown by arrow E, the limit switch
18B operates by hitting the cam 18a or 18b, and the switch lever 19a of the front / rear / side area changeover switch means 19 contacts the contact F.
Enter R [S128]. As a result, the turning circle extension signal transmission circuit 2
Current flows to 5 through contact FR [S129], and transmission circuit 17
By energizing B and 17C, the turning circle selection unit 21 replaces the selected left turning small circle Z with the turning large circle X [S1.
32]. The relay relays RST1 and RST2 for resetting are excited by connecting the contact FR in step 128 [S13
0], and the switches r1R, r1L, r2R, r2L are connected [S131]. This is because the switch lever 19a of the front / rear / side area changeover switch means 19 is used in step 120 described above.
If any of the switches r1R, r1L, r2R, r2L are separated from each other as described later when the switch lever 19a enters the contact S, the switch r1R, r1L, r2R, r2L is separated. This is because it is in the initial state in which the operation of is activated. In the present operation, the operation is not directly related.

The extension amount and the undulation angle of the boom 2 when the gondola 7 is located at the point are detected [S133], and the safety area determination unit 23 determines that the circle is within the turning great circle X [S134]. The power supply unit 24 supplies power to the solenoid drive circuits 45 and 52 [S135]. After that, follow steps 136-140,
Same as steps 113-118 above, except for gondola 7
Can be displaced like the arrow [S141]. Assuming that the gondola 7 is located at the point C due to such displacement, it is in the front and rear area [S142], and if work at a high place is to be continued [S143], return to step 133 and displace in the same manner as arrow G. Can be done [S141]. On the other hand, when the work at a high place is not continued [S143], the boom 2 is contracted, laid down, and turned [S145] in the same manner as in Steps 126 to 127 by following Steps 143-145.

By the way, in step 134, if the gondola 7 is on the spot, steps 146 to 148 are followed and steps 121 to 123 are performed.
The boom 2 is reduced or erected so that the gondola 7 returns to the great turning circle X in the same manner as in [S149]. If the gondola 7 is displaced as indicated by the arrow N and returned to the turning great circle X [S134], it can be displaced like the arrow [S141]. By the way, when the gondola 7 is in the lateral area, either the switch r1L or r2R is not energized, and the safety area determination drive command means 20 does not supply power to the solenoid drive circuit 52. However, since power is supplied from the transmission circuit 17C through the circuit 53, the solenoids SOL1 and SOL2 are excited at the same time,
It is possible to turn outside the turning great circle X.

Now, at step 142, when the gondola 7 turns to the side area like a dot as shown by the arrow W, the limit switch 18B is disengaged from the cam 18a and the like, and the switch lever 19a of the front / rear / side area changeover switch means 19 is moved. Enters contact point S [S150]. As a result, power supply to the turning circle extension signal transmission circuit 25 is stopped [S151], and it is further determined whether the boom 2 is in the left side area [S152]. Since the dot is located in the left area, the right switch 17R of the left / right area changeover switch means 17 is turned off and the left switch 17L is turned on [S153]. A current flows only in the transmission circuit 17A, and the swing great circle X selected by the swing circle selecting unit 21 is returned to the swing small circle Z [S154]. The extension amount and the undulation angle of the boom 2 are detected [S155], and it is determined that the gondola 7 is outside the turning small circle Z [S156]. Safety area judgment drive command means 20
No power is supplied to the solenoid drive circuits 45, 52 from the third solenoid valve 44, the drain circuit 46 is opened by the third solenoid valve 44, and the first solenoid valve 38A and the second solenoid valve 38B are also closed by the supply / discharge circuits 34, 35. Since the boom 2 is turning to the left, the hydraulic oil is introduced from the high pressure supply / discharge circuit 35 into the second oil chamber 27b of the double-acting cylinder 27 through the oil passage 33b. Therefore, piston 2
8 is moving leftward in FIG. 8 [opposite to the figure], and it is detected that the turning motor 5 is turning left [S15
7]. After that, perform steps 158 to 163 in step 52 described above.
.. 57 (see FIG. 6 (c)), the operator reversely operates the lever to return the lever to the front and rear regions as indicated by the arrow. When the point is reached [S164], the flow returns to step 128, and the contact FR is turned on by the front / rear / side area changeover switch means 19, and as long as it is in the front / rear area, the boom 2 is expanded / contracted / raised / removed in the same manner as the arrow G in step 141. Each movement of turning can be performed. At this time, in step 130, the reset relay coils RST1, RST2 are excited [S130], and the switches r1R, r
1L, r2R, r2L are connected [S131]. Therefore, the switches r1R and r1L that were opened when the switch lever 19a entered the contact S are closed. After that, switch lever 19a
Is prepared so as not to hinder the operation when the contact enters the contact S. In step 156, if it is within the turning small circle Z as shown by point a, the process returns to step 113 and the displacement can be performed in the same manner as arrow B [S119].

On the other hand, when the gondola 7 turns right as shown by the arrow T and is displaced to the point yo, it is determined in step 142 that the gondola 7 is not in the front-rear region, and thereafter, steps 150 to 152, and further steps 165 to 168, step 157, Steps 169 to 174 are traced back to the front and rear regions as indicated by the arrow mark. Note that the step 166 differs from the above case in that the circle Y is being returned. Steps 169 to 174 are the same as the above-mentioned steps 45 to 50 [see FIG. 6 (c)].

On the other hand, when the gondola 7 is located at the point So, the boom 2 is in the right area [S106].
The left switch 17L of 17 is turned off and the right switch 17R is turned on [S175], and current flows to the transmission circuits 17A and 17B.
A circle that can be turned by the turning circle selection unit 21 is selected as the turning circle Y [S176]. The gondola 7 is in the front and rear area [S177],
The limit switch 14B is operating in contact with the semi-great circle cam surface 14a, and the following steps 128 to 140 can be followed to extend / contract / ravel / swivel the boom 2 in the same manner as the arrow G mentioned above [S141]. If the boom 2 is in the position like the dot, it is determined that the boom 2 is in the lateral area [S177], and the step 17
8 to 185 can be traced in the same manner as in steps 113 to 118, and the gondola 7 can be displaced as shown by the arrow [S18
6]. Now, if you deviate from the circle Y during turning like the point [S
179], following steps 188 to 190, it is returned to the inside of the turning circle Y as indicated by the arrow La, and thereafter, the gondola 7 can be displaced similarly to the arrow Ne [S186]. When the gondola 7 enters the front / rear area [S187] and stops high-altitude work [S192], it follows steps 193 to 194 and is returned to the home position. When continuing work at high places [S192],
After returning to step 128, the gondola 7 can be displaced in the same manner as arrow G [S141]. Also, step 168
In, if the gondola 7 is located at the point m, it is determined that the gondola 7 is within the turning circle Y, and the steps 180 to 185 can be followed and the displacement can be made in the same manner as the arrow [S186].

As can be seen from the above description of the operation, even if the outrigger 6 has a small protrusion on the left side and a medium amount on the right side, if the boom 2 is in the front-rear region, the safely extended large circle X is inside. The gondola 7 can be freely displaced with to perform high-altitude work efficiently. Furthermore, when in the lateral region, the gondola 7 can be freely displaced within the turning small circle Z on the left side and within the turning circle Y on the right side. Further, regardless of whether the outriggers 6 on the left and right sides are small or medium, the turning small circle Z and the turning middle circle Y when the gondola 7 is in the lateral area.
Inside, it can be displaced in the turning great circle X when it is in the front-back area. Further, on either the left side or the right side, the gondola 7 can be smoothly moved when the outrigger 6 has a large or medium amount or a large or small amount, similarly to the case of the small or medium state.

Next, a case where the outriggers have the same maximum overhang on the left and right sides will be described. The outrigger extension position determining means 16 determines that the left outrigger extension amount is not the minimum [S103], and is not in the middle [S195], and is large [S19].
6]. On the other hand, it is determined that the right outrigger protrusion amount is large [S197]. After that, steps 198 to 213 can be followed in the same manner as steps 61 to 76 shown in FIG.

[Brief description of drawings]

FIG. 1 is a block diagram of a safety device for an aerial work vehicle according to the present invention, and FIG.
The figure is an external front view of an aerial work vehicle, Fig. 3 is an overall schematic view of a hydraulic circuit in an aerial work vehicle, Figs. 4 (a) and 4 (b) are explanatory views of displacement of a gondola, and Fig. 5 is each electromagnetic. FIG. 6 (a) to FIG. 6 (d) are flowcharts for explaining the operation, FIG. 7 is a configuration diagram of a safety device for an aerial work vehicle of the second invention, FIG. FIG. 8 is an operation signal transmission circuit diagram for operating each solenoid valve in the second invention, FIGS. 9 (a) to (g) are flowcharts for explaining the operation in the second invention, and FIG. FIG. 11 is an explanatory view of the displacement of the boom in the invention of FIG. 11, and FIG. 11 is an explanatory view of the movable range of the boom in the prior art. 2 ... boom, 5 ... swing motor, 6 ... outrigger,
11 …… Boom extension amount detecting means, 12 …… Boom hoisting angle detecting means, 13R …… Right outrigger extension amount detecting means, 13L …… Left outrigger extension amount detecting means, 14 …… Boom left / right position detecting means, 16 ...... Outrigger overhang position determination means, 17 …… Left and right area changeover switch means, 18 …… Boom front / rear / side position detection means, 19 …… Front / rear / side area changeover switch means, 20 ...
... Safety area determination drive command means, 26 ... turning direction detection means, 27a ... first oil chamber, 27b ... second oil chamber, 28 ... piston, 29 ... piston rod, 32A, 32B ... contact, 34,35 ...
… Supply / discharge circuit, 36 …… Boom turning forward direction regulation means.

Claims (2)

[Claims] 1. An outrigger for supporting a body posture, in which a boom mounted on a vehicle body can freely extend, retract, rise and fall, and can extend and contract laterally and toward the ground on both front and rear ends of the vehicle body. In an aerial work vehicle equipped with, the boom extension amount detecting means for detecting the extension amount of the boom, the boom elevating angle detecting means for detecting the hoisting angle of the boom, and the overhang amount of the outrigger on the right side. Signals from the right outrigger extension amount detecting means for detecting, the left outrigger extension amount detecting means for detecting the extension amount of the left outrigger, and the signals from the right outrigger extension amount detecting means and the left outrigger extension amount detecting means. In response, the outrigger extension position determination means for determining each extension position of the left and right outriggers, and the boom left and right position for separately detecting the turning position of the boom described above on the left side and the right side. The output means, a left / right area changeover switch means that receives a signal from the outrigger extension position determination means, and is switched by the operation of the boom left / right position detection means, and the boom extension amount detection means and the boom hoisting angle detection means. The signal is received and the signal output by the operation of the left and right area changeover switch means determines whether or not the boom is in the safety area, and when the boom is in the safety area, the boom can be extended, retracted, raised and lowered, and turned. And a safety region determination drive command means for outputting a command signal to the first oil chamber connected to one supply / discharge circuit of the swing motor for rotating the boom, or a second oil chamber connected to the other supply / discharge circuit of the swing motor. The high-pressure oil of the swing motor at that point displaces the piston, and the movement of the piston rod switches the contact opening / closing to detect the swing direction of the boom. A turning direction detecting means, a signal from the safety area determination drive commanding means, and an operation of the turning direction detecting means to restrict the forward direction of the boom and to allow the reverse direction of the boom to rotate in the forward direction. Safety equipment for aerial work vehicles, characterized by being provided with. 2. An outrigger for supporting a vehicle body posture, wherein a boom mounted on the vehicle body can freely extend / contract, elevate / retract, and turn, and is extendable / contractible laterally and to the ground on both front and rear ends of the vehicle body. In an aerial work vehicle equipped with, the boom extension amount detecting means for detecting the extension amount of the boom, the boom elevating angle detecting means for detecting the hoisting angle of the boom, and the overhang amount of the outrigger on the right side. Signals from the right outrigger extension amount detecting means for detecting, the left outrigger extension amount detecting means for detecting the extension amount of the left outrigger, and the signals from the right outrigger extension amount detecting means and the left outrigger extension amount detecting means. In response, the outrigger extension position determination means for determining each extension position of the left and right outriggers, and the boom left and right position for separately detecting the turning position of the boom described above on the left side and the right side. The output means, the left / right area changeover switch means that receives a signal from the outrigger extension position determination means, and is switched by the operation of the boom left / right position detection means, and the swing position of the boom are divided into front and rear and side directions. The boom front / rear / side position detecting means for detecting, the front / rear / side area changeover switch means for switching by the operation of the boom front / rear / side position detecting means, the boom extension amount detecting means and the boom hoisting angle detecting means. In response to the signal and the signal output by the operation of the front / rear / side area changeover switch means and the operation of the left / right area changeover switch means, it is determined whether or not the boom is in the safe area, and the boom is in the safe area. At this time, the safety area determination drive command means that outputs a command signal that enables the boom to expand / contract / raise / reverse, and the boom's turning position in the lateral area. In response to this, if the front / rear / side area changeover switch means is switched, the first oil chamber connected to one supply / discharge circuit of the swing motor for rotating the boom or the second oil connected to the other supply / discharge circuit of the swing motor. A turning direction detecting means for detecting the turning direction of the boom by displacing the piston by the high-pressure oil of the turning motor introduced into the chamber at that time, and switching the contact through the movement of the piston rod; A boom turning forward direction restricting means that restricts the forward turning direction of the boom by the signal from the commanding means and the operation of the turning direction detecting means and allows the turning in the reverse direction is provided. Work vehicle safety device.