JPH11342221A - Truck for working at height elevation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expand and contract a telescopic boom with easy operation and minimize an overturning moment which acts to a car body. SOLUTION: The telescopic boom 3, which is composed of unit booms 3a, 3b, 3c, 3d that are three or more and relative movable to lengthwise direction, is supported with a car body to be rockable for its front end vertically. When the single operation body for telescopic boom is set on the expanding position, after outputting the expanding signal to the first telescopic motion mechanism 9, the expanding signal is output to the second telescopic motion mechanism. And when the operation body is set on the contracting position, after outputting the contracting signal to the second telescopic motion mechanism, the contracting signal is output to the first telescopic motion mechanism. Only the top unit boom 3d is driven to expand and contract to the boom lengthwise direction against the unit boom, except for the top unit boom, 3a, 3b, 3c, by the first telescopic motion mechanism. Only the unit booms 3a, 3b, 3c, except for the top unit boom, are driven to expand and contract to the boom lengthwise direction against one another by the second telescopic motion mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aerial work vehicle such as a fire-fighting ladder vehicle having a ladder-type boom.

[0002]

2. Description of the Related Art A telescopic boom constructed by connecting three or more unit booms vertically stacked so as to be relatively movable in a longitudinal direction of the boom, and a front end of the telescopic boom is connected via a lowermost unit boom. A vehicle body that supports the rear end side so that it can swing up and down, and only the uppermost unit boom of all unit booms can be driven to extend and contract along the boom longitudinal direction with respect to unit booms other than the uppermost unit. Conventionally, an aerial work vehicle including a first telescopic mechanism and a second telescopic mechanism capable of driving only a unit boom other than the topmost one of all the unit booms with respect to each other along the boom longitudinal direction has been used. ing.

[0003] A conventional aerial work vehicle has an operation lever for extending and retracting the uppermost unit boom by a first telescopic mechanism,
An operation lever is provided for extending and retracting the unit booms other than the topmost one by the second extension mechanism. Therefore, in order to extend and retract the telescopic boom, an operation of extending and retracting the uppermost unit boom by the first telescopic mechanism and an operation of expanding and contracting the unit booms other than the uppermost stage by the second telescopic mechanism are required.

[0004]

However, independent operation of such a plurality of operation levers is complicated and requires skill. For this reason, extending the unit boom other than the heaviest top unit boom before the lightest top unit boom, or reducing it later, increases the overturning moment acting on the car body, A sudden change in the moving speed of the basket due to expansion and contraction causes a problem that a shock acts on a person riding on the basket. In addition, when a water gun or camera is attached to the uppermost unit boom, problems such as the inability to discharge water to a target and a disturbed image taken by the camera arise.

In the conventional configuration, the drive system of the first telescopic mechanism such as a hydraulic cylinder that expands and contracts the uppermost unit boom is provided on the second unit boom from the top. This is because, when only the unit booms other than the uppermost stage are driven to extend and contract with respect to each other along the boom longitudinal direction by the second telescopic mechanism, the boom longitudinal direction between the uppermost unit boom and the second unit boom from the top This is to prevent the relative position from changing. However, when the drive system is provided on the second unit boom from the top, there is a problem that the overturning moment acting on the vehicle body increases.

An object of the present invention is to provide an aerial work vehicle capable of solving the above problems.

[0007]

SUMMARY OF THE INVENTION The present invention provides a telescopic boom constituted by connecting three or more unit booms vertically stacked so as to be relatively movable in the longitudinal direction of the boom, and a telescopic boom at a lowermost position. The body that supports the rear end side so that the front end can move up and down through the unit boom and the top unit boom of all the unit booms, and A first telescopic mechanism that can be driven to expand and contract along the direction, and a second telescopic mechanism that can drive only the unit booms other than the topmost one of all the unit booms relative to each other along the boom longitudinal direction. Applies to work vehicles.

In the aerial work vehicle according to the present invention, a single boom extending / contracting operation body whose position can be changed between an extension position, a contraction position, and a neutral position, and the operation body are arranged at the extension position. At the time, the extension signal is outputted to the first extension mechanism, and then the extension signal is outputted to the second extension mechanism. When the operating body is placed at the boom reduction position, the contraction signal is outputted to the second extension mechanism, and then the first extension mechanism is outputted. A control device for outputting a contraction signal to the extension mechanism is provided, and the extension boom is driven by each extension mechanism when the extension signal is output, and is contracted when the contraction signal is output. . According to this configuration, the lightweight uppermost unit boom is reliably extended by operating only a single operation body before the unit booms other than the uppermost unit, and
It can be reduced later. Therefore, when it is not necessary to completely extend the telescopic boom, the overturning moment acting on the vehicle body can be reliably reduced as much as possible.

In the aerial work vehicle of the present invention, when the extension speed of the topmost unit boom is gradually reduced from the full speed state before the extension speed of the topmost unit boom becomes zero, the extension speed of the unit booms other than the topmost stage gradually increases from zero. Each of the telescopic mechanisms is controlled so as to be accelerated,
When gradually reducing the speed from the full speed state before the reduction speed of the unit booms other than the uppermost stage becomes zero, each of the expansion and contraction mechanisms is controlled such that the reduction speed of the uppermost unit boom is gradually increased from zero. Preferably. Thus, when the telescopic boom is extended, the sudden change in the extension speed of the telescopic boom can be reduced or eliminated by starting the extension of the unit booms other than the top one before the extension of the topmost unit boom ends. Can be. In addition, when the telescopic boom is reduced, it is possible to reduce or eliminate a sudden change in the contraction boom's reduction speed by starting the reduction of the uppermost unit boom before the reduction of the unit booms other than the top one ends. it can. Therefore, it is possible to prevent a sudden change in the moving speed of the basket due to expansion and contraction of the telescopic boom without requiring skill.

[0010] The number of the unit booms is an even number of 4 or more, and the first telescopic mechanism has a wire for extension, a wire for contraction, and a winding drum provided at the rear end side of the lowermost unit boom. The extension wire has one end connected to the rear end of the uppermost unit boom, the other end connected to the winding drum, and the lowermost unit boom serving as the first unit boom, with an odd number of steps between both ends. It is wound around the front end of the unit boom of the eye and the rear end of the even-numbered unit boom other than the unit boom at the top, and its reduction wire is connected at one end to the rear end of the top unit boom. The other end is connected to the winding drum, and between both ends is a rear end side of an odd-numbered unit boom other than the lowermost unit boom and a front end side of an even-numbered unit boom other than the uppermost unit boom. And the winding drum rotates forward. The top unit boom is extended by winding the extension wire and feeding the reduction wire, and the top unit boom is reduced by feeding the extension wire and winding the reduction wire by reversing the winding drum. Preferably. According to this configuration, only the uppermost unit boom can be driven to expand and contract along the boom longitudinal direction with respect to the unit booms other than the uppermost unit by rotation of the winding drum of the first telescopic mechanism. Further, when only the unit booms other than the uppermost stage are driven to expand and contract with respect to each other along the longitudinal direction of the boom by the second telescopic mechanism, the relative positions of the extending portions of the extension wires and the reduction wires in the unit booms other than the uppermost stage. Since the arrangement changes, the top unit boom,
It is possible to prevent the length of the extension wire and the reduction wire from changing between the unit boom of the second stage from the top. That is, the drive system of the first telescopic mechanism for expanding and contracting the uppermost unit boom is not provided on the second unit boom from the top.
When only the unit booms other than the top stage are extended and contracted with respect to each other in the longitudinal direction of the boom by the second telescopic mechanism, the boom of the top unit boom in the extended state and the unit boom at the second stage from the top A change in the relative position in the longitudinal direction can be prevented. Thus, the winding drum of the first telescopic mechanism is provided on the lowermost boom, and the overturning moment acting on the vehicle body can be reduced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a fire ladder car 1 as an example of an aerial work vehicle. The ladder vehicle 1 includes a vehicle body 2 and a ladder-type telescopic boom 3 supported by the vehicle body 2. The vehicle body 2 is supported by front and rear wheels 4 and 5, a cabin 6 that covers a cab is attached to a front part, and a turntable 7 that can be turned around a vertical axis is provided at a rear part. A conventionally known drive control mechanism for the drive motor 29 of the turntable 7 can be used. Outriggers 28 are provided before and after the left and right side walls of the vehicle body 2. Each of the outriggers 28 is a support leg 28 'that is driven to expand and contract vertically.
And supports the vehicle body 2 by grounding the support legs 28 '. A conventionally known drive control mechanism for each outrigger 28 can be used. When the grounding surface of the ladder car 1 is inclined, a mechanism for correcting the inclination may be provided. As the inclination correction mechanism, the expansion and contraction dimensions of the support legs of each outrigger are set according to the inclination. A conventionally known mechanism for changing or tilting the turntable 7 according to the tilt can be used.

As shown in FIG. 2, the boom 3 has four unit booms 3a, 3b, 3c, 3d which are vertically stacked.
Are connected so as to be relatively movable in the longitudinal direction of the boom, and the longitudinal direction is the front-back direction. The unit booms 3d at the top are the unit booms 3a, 3b other than the top.
3c is lighter than each. Each unit boom 3
a, 3b, 3c and 3d are rectangular frame-shaped bottom portions 3A
And a rectangular frame-shaped side portion 3B extending upward from both sides of the bottom portion 3A, and are relatively slidable via a roller 3C and a guide 3D.

As shown in FIG. 1, the boom 3 is supported by the vehicle body 2 via a lowermost unit boom 3a so that the rear end can swing up and down so that the front end moves up and down. That is, the lowermost unit boom 3 a has the receiving member 27 that is swingably mounted on the support member 21 fixed on the turntable 7 about the horizontal axis 22. A tube of a double-acting hydraulic cylinder 23 is swingably connected to the support member 21 around the horizontal axis 24.
Is connected to the receiving member 27 so as to be swingable about the horizontal axis 25. Thereby, the hydraulic cylinder 23
The boom 3 is swung up and down by the expansion and contraction drive of. The horizontal axis 22 serving as the swing center of the boom 3 extends in the left-right direction when the longitudinal direction of the boom 3 extends in the front-rear direction of the vehicle body. The vertical swing range is set such that the front end of the boom 3 can be arranged above or below the rear end. In a standby state described later with reference to FIG. 1, the front end side of the boom 3 is supported by the vehicle body 2 via the support pillar 41. A conventionally known drive control mechanism for the hydraulic cylinder 23 can be used.

As shown in FIG. 3, all unit booms 3a, 3b
b, 3c, 3d, only the uppermost unit boom 3d,
A first telescopic mechanism 9 that can be driven to expand and contract along the longitudinal direction of the boom is provided for the unit booms 3a, 3b, and 3c other than the topmost one.

That is, the first telescopic mechanism 9 has a pair of left and right extension wires 61 indicated by two-dot chain lines and reduction wires 71 indicated by one-dot chain lines in FIG. A winding drum 60 provided on the rear end side of the boom 3a, and as shown in FIG.
And a reciprocally rotatable hydraulic motor 91 for driving the motor, and an electromagnetic proportional valve 92 connected to the hydraulic motor 91. As the electromagnetic proportional valve 92, a known one can be used, and a control device 90 constituted by a computer is used.
To supply hydraulic oil discharged from a pump 93 to a hydraulic motor 91 in response to a signal from the control device 90 and to return oil discharged from the hydraulic motor 91 to a tank 94, whereby the hydraulic motor 91 is driven at a speed and direction according to a signal from the control device 90.

One end of the extension wire 61 is connected to the rear end of the uppermost unit boom 3d, and the other end is connected to the winding drum 60. The front end of the lowermost unit boom 3a, which is the odd-numbered unit boom, and the lowermost unit first boom 3a and the third unit boom 3c are located between both ends of the extension wire 61 with the lowest unit boom 3a as the first unit boom. Are wound around the rear end side of the second-stage unit boom 3b, which is an even-numbered unit boom other than the uppermost unit boom 3d, via a pulley 64.

The reduction wire 71 has one end connected to the rear end of the uppermost unit boom 3d and the other end connected to the winding drum 60. Also, this reduction wire 71
Is wound around the rear end side of the third unit boom 3c, which is an odd-numbered unit boom other than the lowermost unit boom 3a, via the pulley 72, and the other end of the unit boom 3d other than the uppermost unit boom 3d. It is wound around the front end side of the second-stage unit boom 3b, which is the even-numbered unit boom, via the pulley 73.

The winding drum 60 can be driven to rotate forward and backward about a horizontal axis by a hydraulic motor 91, and its rotation axis extends in the left-right direction when the boom 3 moves in the front-rear direction of the vehicle body 2. The winding drum 60 rotates forward in the direction indicated by the arrow A in FIG. 3 to wind the elongating wire 61 and feed out the reducing wire 71, so that all the booms 3a, 3b, 3c, and 3d At the top of the unit boom 3
Only d is extended along the longitudinal direction of the boom with respect to the unit booms 3a, 3b, 3c other than the top row, and the extension of the extension wire 61 and the winding of the reduction wire 71 by reversing in the direction shown by the arrow B direction. By taking, all unit boom 3
Only the uppermost unit boom 3d among the units b, 3b, 3c and 3d is reduced along the boom longitudinal direction with respect to the unit booms 3a, 3b and 3c other than the uppermost unit boom.

As shown in FIG. 4 and FIG.
a, 3b, 3c, 3d, other than the topmost unit boom 3
A second telescopic mechanism 10 capable of driving only a, 3b, and 3c to expand and contract with respect to each other along the boom longitudinal direction is provided.

The second telescopic mechanism 10 has a first
The extension wire 11, the second extension wire 12 indicated by a two-dot chain line, the first reduction wire 13 indicated by a broken line, the second reduction wire 14 indicated by a one-dot chain line, and a double-acting hydraulic cylinder 15.
And an electromagnetic proportional valve 95 connected to the hydraulic cylinder 15 as shown in FIG. As the electromagnetic proportional valve 95, a known one can be used. In response to a signal from the control device 90, a hydraulic oil discharged from the pump 93 is supplied to the hydraulic cylinder 15 and oil discharged from the hydraulic cylinder 15 is discharged. Tank 9
4, the hydraulic cylinder 15 is driven at a speed and direction according to a signal from the control device 90.

The first extension wire 11 has one end connected to the rear end of the third unit boom 3c, the other end connected to the front end of the lowermost unit boom 3a, and two ends between the two ends. It is wound around the front end side of the eye unit boom 3b via the pulley 16. One end of the second extension wire 12 is connected to the rear end of the second unit boom 3b, the other end is connected between the front and rear ends of the lowermost unit boom 3a, and the lower end of the lower unit boom 3a. The front end side of the boom 3a and the lowermost unit boom 3a
Is wound around the rear end of the hydraulic cylinder 15 and the telescopic rod of the hydraulic cylinder 15 via pulleys 17, 18, 19 sequentially from one end. One end of the first reduction wire 13 is connected to the rear end of the third unit boom 3c, the other end is connected to the front end of the lowermost unit boom 3a, and the second unit boom is connected between both ends. It is wound around the rear end side of the boom 3b via the pulley 20. One end of the second reduction wire 14 is connected to the front end side of the second-stage unit boom 3c, and the other end is connected to the hydraulic cylinder 1
5 telescopic rod.

The cylinder tube of the hydraulic cylinder 15 is fixed to the lowermost unit boom 3a, and the extensible rod is extendable in the longitudinal direction of the boom. By the expansion and contraction of the hydraulic cylinder 15, all the booms 3a, 3b, 3c,
Only the unit booms 3a, 3b and 3c other than the top one in 3d are extended and contracted with respect to each other in the longitudinal direction of the boom, and the second and third unit booms 3b and 3c with respect to the bottom unit boom 3a. Can be stretched.

The control device 90 is provided with a telescopic input device 8 having a single lever-shaped boom telescopic operating body 86a.
6 are connected. The operating body 86a for extending and retracting the boom
Is operated by swinging, so that the extended position, the contracted position,
The position can be changed between the neutral position and, for example, the operator is seated on a seat 87 provided on the vehicle body 2 or placed in a position operable by an operator who rides on a basket 30 described later.

When the boom expansion / contraction operating body 86 a is operated to be located at the extension position, the input device 86 outputs an extension operation signal to the control device 90. When the extension operation signal is input, the control device 90 outputs an extension signal to the electromagnetic proportional valve 92 of the first telescopic mechanism 9 and then outputs an extension signal to the electromagnetic proportional valve 95 of the second telescopic mechanism 10. . When the extension signal is output, the boom 3 is extended and driven by each of the extension mechanisms 9 and 10. That is, FIG.
When the boom extending / contracting operating body 86a is displaced to the extended position in a state where the boom 3 is most contracted as shown in (1), first, as shown in (2) in FIG. Of the unit boom 3d starts extending, and then the unit boom 3
a, 3b, and 3c start extending, and thereafter, the boom 3 becomes the most extended state as shown in (3) of FIG. When the boom extension / retraction operating body 86a is returned to the neutral position during the extension of the boom 3, the extension of the boom 3 is stopped.

Each telescopic mechanism 9, 1 by the control device 90
When the boom 3 is extended by the control of 0, first, FIG.
As indicated by the alternate long and short dash line in (1) of FIG. 4, the extension speed of the uppermost unit boom 3d is initially set to the full speed state, and then gradually reduced to zero in the maximum extension state. When gradually decelerating from the full speed state before the extension speed of the uppermost unit boom 3d becomes zero (between t1 and t2 in the figure), as indicated by a two-dot chain line in (1) of FIG. The extension speeds of the unit booms 3a, 3b, 3c other than the top row are gradually increased from zero. Thereafter, the unit booms 3a, 3b, and 3c other than the uppermost stage gradually decelerate after reaching the full speed state, and reach the maximum elongation state at time t3 at zero speed. In the present embodiment, the extension speed of the uppermost unit boom 3d at the time of deceleration and the unit booms 3 other than the uppermost unit at the time of acceleration are increased.
The sum of the extension speeds a, 3b, 3c is equal to the full-speed V of the unit boom 3d at the uppermost stage and the unit booms 3a, 3b, 3c other than the uppermost stage.

When the boom extending / contracting operating body 86a is operated so as to be located at the reduced position, the input device 8 is operated.
6 outputs a reduction operation signal to the control device 90. When the reduction operation signal is input, the control device 90 controls the second
After outputting a contraction signal to the electromagnetic proportional valve 95 of the telescopic mechanism 10, it outputs a contraction signal to the electromagnetic proportional valve 92 of the first telescopic mechanism 9. When the reduction signal is output, the boom 3 is reduced and driven by each of the extension mechanisms 9 and 10. That is,
As shown in (3) of FIG. 13, when the boom extending / contracting operating body 86a is displaced to the reduced position in a state where the boom 3 is most extended, first, the unit booms 3a, 3b, 3c starts reducing, and then the rotation of the hydraulic motor 91 causes the uppermost unit boom 3d to start reducing as shown in FIG. 13 (2), and thereafter, as shown in FIG. 13 (1). The boom 3 is in the state of being reduced most. When the boom extension / retraction operating body 86a is returned to the neutral position while the boom 3 is being extended, the boom 3 stops reducing.

Each telescopic mechanism 9, 1 by the control device 90
In the case of reducing the boom 3 by the control of 0, first, FIG.
As indicated by the two-dot chain line in (2) of (4), the reduction speeds of the unit booms 3a, 3b, and 3c other than the uppermost stage are initially set to the full speed state, and then gradually reduced to zero in the minimum reduction state. When gradually decreasing from the full speed state before the reduction speed of the unit booms 3a, 3b, 3c other than the uppermost stage becomes zero (between t4 and t5 in the figure), one point in (2) of FIG. As indicated by the chain line, the reduction speed of the uppermost unit boom 3d is gradually increased from zero. Thereafter, the unit boom 3d at the uppermost stage is gradually reduced after reaching the full speed state, and reaches zero speed at time t6 to be in the minimum contraction state. In the present embodiment, the sum of the reduction speeds of the unit booms 3a, 3b, and 3c other than the topmost unit boom at the time of deceleration and the reduction speed of the topmost unit boom 3d at the time of acceleration is the topmost unit boom 3d.
It is set equal to the speed V at full speed of the unit booms 3a, 3b, 3c other than d and the top row.

The controller 90 includes a sensor 155 for detecting the amount of expansion and contraction of the uppermost unit boom 3d and a sensor 1 for detecting the amount of expansion and contraction of the unit booms 3a, 3b and 3c other than the uppermost unit.
56 are connected. When the amount of expansion and contraction detected by each of the sensors 155 and 156 reaches a predetermined amount (the time t
(1, t2, t4, t5), the expansion and contraction speed of the boom 3 changes as described above, and the expansion and contraction of the boom 3 stops when the boom 3 expands and contracts the most (time t3, t6).
Each telescopic mechanism 9, 10 is controlled. Each sensor 155, 1
Reference numeral 56 denotes a potentiometer that detects the amount of rotation of the hydraulic motor 91 and the amount of expansion and contraction of the hydraulic cylinder 15, for example.

As shown in FIGS. 6 and 7, the uppermost unit boom 3d can be bent around the center of the refraction axis 80, and the refraction axis 80 is set so that the longitudinal direction of the uppermost unit boom 3d is the front and rear of the vehicle body 2. Along the left and right direction when along the direction. That is, the uppermost unit boom 3d is divided into two front and rear portions at a position closer to the front end than at the center between the front and rear portions.
The dA and the rear portion 3 dB are connected by a connecting shaft so as to be relatively swingable, and the center of the connecting shaft is a refraction axis 80.

Further, there is provided a refraction mechanism 81 which can refractively drive the uppermost unit boom 3d around the refraction axis 80. The bending mechanism 81 has a double-acting hydraulic cylinder 81a, and as shown in FIG.
a having an electromagnetic proportional valve 102 connected thereto. The valve 102 may be a known one and is connected to the control device 90. The input device 141 connected to the control device 90 includes, for example, a lever-shaped refraction operating body 141a.
Is provided so as to be capable of reciprocating swing operation between a straight position and a bent position. The operating body 141a is arranged at a position operable by, for example, an operator sitting on a seat 87 provided on the vehicle body 2 or an operator riding a basket 30 described later. The input device 1 according to the operation position of the operation body 141a
In response to the signal output from 41 to the control device 90, a signal is output from the control device 90 to the valve 102. Thus, the valve 102 supplies the hydraulic oil discharged from the pump 93 to the hydraulic cylinder 81a and returns the oil discharged from the hydraulic cylinder 81a to the tank 94, thereby driving the hydraulic cylinder 81a to expand and contract. The hydraulic cylinder 81a includes a cylinder tube that is swingably connected to a rear portion 3dB of the uppermost unit boom 3d around an axis 81a 'parallel to the refraction axis 80, and a front portion 3dA of the uppermost unit boom 3d. Axis 81a ″ parallel to refraction axis 80
And a telescopic rod pivotally connected to the center. As a result, the uppermost unit boom 3d is driven to bend so that the front end thereof is directed downward as the bending operation body 141a is swung toward the bending position and the hydraulic cylinder 81a is extended, and the bending operation body is bent. 141a is swung toward the straight position and the hydraulic cylinder 81a is contracted, and the front end is driven to bend upward to return to a straight state as the hydraulic cylinder 81a is reduced.
The drive is stopped at a bending angle corresponding to the operation stop position of the operation body 141a for refraction.

At the front end of the uppermost unit boom 3d,
The basket 30 is swingably mounted around the swing shaft 31 via the connecting member 51. The swing shaft 31 extends in the left-right direction when the longitudinal direction of the boom 3 extends in the front-rear direction of the vehicle body 2.

That is, as shown in FIGS. 8 and 9, the basket 30 has a bottom plate 30a and a fence 30b surrounding the bottom plate 30a, and the upper surface of the bottom plate 30a is a floor surface. . A part of the front of the fence 30b can be opened and closed via a hinge as shown by a two-dot chain line in FIG.

The front end of the uppermost unit boom 3d is a frame-shaped basket support 3d '. The connecting member 51 is connected to the basket support 3d '.
Receiving portion 51a connected to the left and right front ends via a support shaft 52 so as to be relatively rotatable, and a protruding portion 51b whose left and right width gradually decreases as it protrudes forward from the receiving portion 51a.
And The axis of the support shaft 52 is the swing shaft 31.

At the rear of the fence 30b of the basket 30,
Upper and lower brackets 53a, 53b arranged above and below the projecting portion 51b of the connecting member 51 are fixed. The protruding portion 51b and the upper and lower brackets 53a, 53b are connected via a connecting shaft 54 so as to be relatively rotatable.
The axis of the connection shaft 54 is a swing shaft 55. Thereby, the basket 30 is attached to the front end side of the uppermost unit boom 3d via the connection member 51 so as to be swingable around the swing shaft 31 and swingable around the swing shaft 55. The swing shaft 55 is arranged in the vertical direction when the floor surface of the basket 30 is horizontal, and is disposed in front of the swing shaft 31.

A swing mechanism 65 capable of swinging the basket 30 around the swing shaft 31 and a swing mechanism 66 capable of swinging the basket 30 around the swing shaft 55 are provided.

The swing mechanism 65 has a basket swing double-acting hydraulic cylinder 65a, a first connecting rod 65b, and a second connecting rod 65c.
As shown in FIG. 2, there is an electromagnetic proportional valve 97 connected to the hydraulic cylinder 65a. Its electromagnetic proportional valve 97
A known oil pump can be used to supply hydraulic oil discharged from the pump 93 to the hydraulic cylinder 65a in response to a signal from the control device 90 and to return oil discharged from the hydraulic cylinder 65a to the tank 94. Then, the hydraulic cylinder 65a is driven at a speed and direction according to a signal from the control device 90.

The hydraulic cylinder 65a of the swing mechanism 65
Are connected to the basket support portion 3d 'by a cylinder tube which is swingably connected to a center of a shaft 65a' parallel to the swing shaft 31, and one end of a first connection rod 65b and one end of a second connection rod 65c. It has a telescopic rod that is swingably connected to a center of a shaft 65a ″ parallel to the swing shaft 31.
The other end of the connecting rod 65b is swingably connected to the basket support 3d 'about a shaft 65b' parallel to the swing shaft 31. The other end of the second connection rod 65c is swingably connected to the connection member 51 about a center of a shaft 65c 'parallel to the swing shaft 31. As a result, the moment around the swing shaft 31 is reduced by the expansion and contraction of the hydraulic cylinder 65a.
Acts on zero.

The basket 30 swings around the swing shaft 31 so that the basket 30 has a use position arranged in front of the boom 3 as shown in FIG. 8 and a portion overlapping the boom 3 in the front-rear direction as shown in FIG. It can be arranged at the storage position where it is put on from above so as to have it. The projecting dimension of the basket 30 forward from the front end of the uppermost unit boom 3d is smaller at the storage position than at the use position,
Thereby, the total length of the ladder car 1 is shorter in the standby state where the basket 30 is in the storage position than when the basket 30 is displaced from the standby state to the use position. The rear portion of the fence 30b of the basket 30 has a roller 30c protruding rearward, and when the basket 30 is displaced to the storage position, the hinge is pushed by the basket support portion 3d 'via the roller 30c. The basket 30 is displaced to the use position, and returns to the original position by the elastic force of a spring (not shown) when the basket 30 is displaced to the use position.

A horizontal holding mechanism for the floor surface of the basket 30 at the use position is provided. That is, the sensor 17 for detecting the inclination of the floor of the basket 30 from the horizontal.
1 is connected to the control device 90, and the control device 90 sends a signal to the electromagnetic proportional valve 97 of the swing mechanism 65 in accordance with the inclination thereof, so that the hydraulic cylinder of the swing mechanism 65 is horizontal so that the floor surface is horizontal. 65a is expanded and contracted.

As shown in FIGS. 9 and 11 (2), the swing mechanism 66 has a double-acting hydraulic cylinder 66a. As shown in FIG. 12, the swing mechanism 66 is connected to the hydraulic cylinder 66a. It has a position electromagnetic switching valve 98. A known valve can be used for the switching valve 98.
Connected to control device 90. An input device 131 connected to the control device 90 is provided with, for example, a lever-shaped swinging operation body 131a that can swing between a neutral position, a right swing position, and a left swing position. The operating body 131a is
For example, it is arranged at a position operable by an operator sitting on a seat 87 provided on the vehicle body 2 or an operator riding a basket 30 described later. A signal is output from the control device 90 to the valve 98 in accordance with a signal output from the input device 131 to the control device 90 in accordance with the operation position of the operation body 131a. Thus, the valve 98 supplies the hydraulic oil discharged from the pump 93 to the hydraulic cylinder 66a and recirculates the oil discharged from the hydraulic cylinder 66a to the tank 94, thereby controlling the hydraulic cylinder 66a to the control device 9
In accordance with the signal from 0, the position is changed to the position for the extension drive, the position for the contraction drive, and the position for stopping the expansion and contraction. The hydraulic cylinder 66a is connected to the protrusion 5 of the connecting member 51.
A cylinder tube 1b is swingably connected to a center of a shaft 66a 'parallel to the swing shaft 55 via a bracket 67, and a shaft 66a parallel to the swing shaft 55 via a bracket 68 to the rail 30b of the basket 30. The basket 30 is swingably driven around the swing shaft 55 by the expansion and contraction of the hydraulic cylinder 66a.

The basket 30 has its swing shaft 55
Due to the swinging around, the front position shown by the solid line in FIG. 9, the right swing position shown by the two-dot chain line R in FIG.
It can be arranged at the left swing position shown by the chain line L. The swing angle from the front position to the right swing position and the swing angle from the left swing position are equal to each other.

As shown in FIGS. 11A and 11B, a sensor 75 capable of detecting whether the basket 30 is located at the front position and the swing direction of the basket 30 is provided. . The sensor 75 includes first to third proximity switches 75 a, 75 b, and 75 c attached to the protrusion 51 b of the connection member 51 so as to be arranged in parallel along the circumference of the connection shaft 54, and is connected to the control device 90. Is done. Also, the fence 30b of the basket 30
The detection plate 76 is attached to the bracket 53b fixed to
Is fixed. When the basket 30 is in the front position, all of the first to third proximity switches 75a, 75b, 75c output the detection signal of the detection plate 76 to the control device 90, and the basket 30 is not in the front position but in the right direction. The first proximity switch 75a does not output the detection signal of the detection plate 76 when the head is swinging, and the third proximity switch 75 when the basket 30 is not in the front position and is swinging to the left. It is assumed that the detection signal 75c does not output the detection signal of the detection plate 76. further,
When the basket 30 is in the right swing position, the first detection switch 75a and the second detection switch 75b do not output the detection signal of the detection plate 76, and when the basket 30 is in the left swing position, the second detection switch 75b. , The third detection switch 75c does not output a detection signal of the detection plate 76. Thereby, the control device 90 can determine whether or not the basket 30 is located at the front position and the swing direction of the basket 30 based on the signal from the sensor 75. Further, the control device 90 can determine whether or not it is located at the left and right swing position which is the limit of the left and right swing range, and does not drive the hydraulic cylinder 66a such that the amount of expansion and contraction becomes excessive. I have.

An input device 96 having a basket storing operation body 96 a is connected to the control device 90. The basket storage operation body 96a is constituted by, for example, a push button switch, and is disposed at a position operable by an operator sitting on a seat 87 provided on the vehicle body 2, for example. When the basket storage operation body 96 a is operated, the input device 96 outputs a storage operation signal to the control device 90.

When a storage operation signal is input from the input device 96, the control device 90 controls the swing mechanism when the position of the basket 30 determined based on the signal from the sensor 75 is the front position. 65 electromagnetic proportional valves 97
When the position of the basket 30 determined based on the signal from the sensor 75 is not the front position, the storage mechanism 3 of the swing mechanism 66 is determined based on the swing direction of the basket 30 detected by the sensor 75. After outputting the return signal to the position electromagnetic switching valve 98, the storage signal is output to the electromagnetic proportional valve 97 of the swing mechanism 65.

The output of the return signal causes the basket 30
Is driven by the swing mechanism 66 so as to return to the upper surface position. That is, the control device 90 controls the basket 3
When the swing direction of 0 is to the right of the front position, a return signal for extending the hydraulic cylinder 66a is output, and when the basket 30 is disposed to the left of the front position, the hydraulic cylinder 66a is contracted. A return signal is output and the sensor 75
When it is detected that the hydraulic cylinder 66a has returned to the front position, the output of the return signal is released and the expansion and contraction of the hydraulic cylinder 66a is stopped. The output of the storage signal also causes the hydraulic cylinder 65
The basket 30 is driven by the rocking mechanism 65 so that the basket 30 is located at the storage position as a is extended. A sensor 151 that operates when the basket 30 is placed at the storage position is provided in the control device 90, and the operation of the sensor 151 stops the extension of the hydraulic cylinder 65a for placing the basket 30 at the storage position. .

As shown in FIG. 1, the basket 30 is located at the storage position, the boom 3 is most reduced, the longitudinal direction of the boom 3 extends along the front-rear direction of the vehicle body 2, and the front end side of the boom 3 is controlled by the vehicle body 2. When supported via the support 41,
The ladder car 1 is in a standby state.

The operation body 101 for preparation for getting on and off the basket
The input device 101 having “a” is connected to the control device 90. The basket getting on / off preparation operating body 101a is constituted by, for example, a push button switch, and is arranged at a position operable by an operator sitting on a seat 87 provided on the vehicle body 2, for example. This basket operating element 1
When 01a is operated in the standby state, the input device 101 outputs a getting-on / off preparation signal to the control device 90.

The controller 90 outputs an extension signal to the electromagnetic proportional valve 92 of the first telescopic mechanism 9 when the getting-on / off preparation signal is inputted from the input device 101 in the standby state, and the electromagnetic proportional The refraction signal is output to the valve 102, and a swing signal is output to the electromagnetic proportional valve 97 of the swing mechanism 65. At this time, the control device 90 determines whether or not the basket 30 is located at the storage position based on a signal from the sensor 151 in order to determine whether or not the ladder vehicle 1 is in a standby state, and determines whether the unit booms 3a, 3b, 3c, 3d
It is determined whether or not the boom 3 is most reduced by the signals from the detection sensors 155 and 156 for the amount of expansion and contraction of the boom 3. The detection sensor 191 for the turning position of the turntable 7 and the detection sensor 192 for the vertical swing angle of the boom 3 It is determined whether or not the longitudinal direction of the boom 3 extends in the front-rear direction of the vehicle body 2 and whether or not the front end side of the boom 3 is supported by the vehicle body 2 via the support pillar 41 based on the signal (1).

As shown in FIG. 6, the uppermost unit boom 3d is driven by the take-up drum 60
Is driven to rotate by the hydraulic motor 91, so that the front end is extended and driven to a position where it can be bent so that the front end is directed downward,
When the hydraulic cylinder 81a is extended by the output of the refraction signal, the front end is refracted downward, and the basket 30 is in the use position by the hydraulic cylinder 65a contracting by the output of the swing signal. The ladder vehicle 1 is disposed at a position where the operator can get on and off the ground surface G of the ladder vehicle 1. At this time, the control device 90 determines whether or not the uppermost unit boom 3d has been extended and driven to a position at which the front end can be bent so that the front end is downward, based on a signal from the sensor 155, and It is determined from the signal from the refraction angle detection sensor 193 whether or not the refraction angle is an angle at which the basket 30 can be arranged at a position where the operator can get on and off the ground surface G of the ladder vehicle 1. The refraction angle detection sensor 193 can be constituted by a potentiometer that detects the amount of expansion and contraction of the hydraulic cylinder 81a. In addition, before the operation of the basket getting on / off operation body 101a, it is preferable that the support leg 28 'of the outrigger 28 is grounded and the inclination is corrected when the inclination correcting mechanism is provided.

According to the above configuration, the lightweight uppermost unit boom 3d can be reliably extended before the unitary booms 3a, 3b, 3c other than the uppermost unit only by operating the single boom extending / contracting operating body 86a. And can be reduced later. Therefore, when it is not necessary to extend the telescopic boom 3 completely, the overturning moment acting on the vehicle body 2 can be reliably reduced as much as possible.

When the telescopic boom 3 is extended, the extension of the telescopic boom 3 is started by starting the extension of the unit booms 3a, 3b, 3c other than the uppermost stage before the extension of the uppermost unit boom 3d is completed. A sudden change in the moving speed of the basket 30 can be reduced or eliminated. When the telescopic boom 3 is reduced, the unit booms 3a, 3a,
Before the reduction of b and 3c is completed, the uppermost unit boom 3d
, The sudden change in the moving speed of the basket 30 due to the contraction of the telescopic boom 3 can be reduced or eliminated. Therefore, it is possible to prevent a sudden change in the moving speed of the basket 30 due to the expansion and contraction of the telescopic boom 3 without requiring skill, and prevent a shock from acting on a person riding on the basket 30.

Also, according to the above configuration, the first telescopic mechanism 9
Of the uppermost unit boom 3 by rotating the take-up drum 60
Only d can be driven to expand and contract with respect to the unit booms 3a, 3b, and 3c other than the top row along the boom longitudinal direction. Further, the unit boom 3 other than the top boom 3 is moved by the second telescopic mechanism 10.
a, 3b, and 3c are extended and contracted along the boom longitudinal direction with respect to each other, and the unit booms 3 other than the topmost one are driven.
In a, 3b, and 3c, the relative positions of the winding portions of the extension wire 61 and the reduction wire 71 change. That is, without changing the lengths of the extension wire 61 and the reduction wire 71 between the uppermost unit boom 3d and the second uppermost unit boom 3c, the unit booms other than the uppermost unit boom 3a, 3b, 3c can be extended and contracted along the boom longitudinal direction with respect to each other, and the lengths of the extension wire and the reduction wire between the uppermost unit boom 3d and the second unit boom from the top change. Can be prevented. Thus, the winding unit 60, which is the drive system of the first telescopic mechanism 9 for expanding and contracting the uppermost unit boom 3d, is not provided on the second uppermost unit boom 3c, and the second telescopic mechanism 10 allows the unit to be moved to a position other than the uppermost unit. Unit booms 3a, 3b, 3
When only “c” is driven to expand and contract with respect to each other along the boom longitudinal direction, it is possible to prevent a change in the relative position in the boom longitudinal direction between the uppermost unit boom 3d and the second uppermost unit boom 3c. Therefore, the winding drum 60 is provided on the lowermost unit boom 3a, and the overturning moment acting on the vehicle body 2 can be reduced.

According to the above structure, the uppermost unit boom 3
The basket 30 attached to d so as to be swingable about the swing shaft 55 can be disposed at a storage position where the basket 30 is placed from above so as to have a portion overlapping the telescopic boom 3 in the front-rear direction. As a result, the uppermost unit boom 3
The amount of forward projection of the basket 30 from d can be reduced, and the overall length of the vehicle during traveling can be shortened to prevent interference with obstacles. Further, by simply operating the basket storage operation body 96, the basket 30 not arranged at the front position can be returned to the front position and then placed at the storage position. This can prevent the problem that the basket 30 not located at the front position swings around the swing shaft 31 and interferes with the telescopic boom 3 or the like.

Further, according to the above configuration, in the standby state, only by operating the basket getting on / off preparation operating body 101a, the front end of the uppermost unit boom 3d is moved relative to the unit booms 3a, 3b, 3c other than the uppermost stage. It extends to the position where it can be bent downward, and then the uppermost unit boom 3d is bent so that the front end is directed downward, and the basket 30 in the storage position is the use position and the ground plane G of the ladder car 1 is used.
It can be placed in a position where you can get on and off from. Thereby, the vehicle body 2
Even when there is no space on the side, the worker can get on the basket 30 from the ground in front of the vehicle body 2 and can perform safe and quick work.

The present invention is not limited to the above embodiment. For example, the number of unit booms is not limited to four as long as the functions and effects of the present invention can be achieved. Further, the present invention can be applied to an aerial work vehicle other than the ladder vehicle 1. Further, as the extension / contraction mechanism of the uppermost unit boom, a mechanism provided on the second unit boom from the top may be used. In the above embodiment, the basket is attached to the uppermost unit boom. However, something other than the basket, such as a water gun or a camera, may be attached. In this case, a sudden change in the expansion / contraction speed of the uppermost unit boom is prevented. This can prevent problems such as being unable to discharge water to the target and disturbing images captured by the camera.

[0056]

According to the present invention, the telescopic boom can be extended and contracted by a simple operation, and the overturning moment acting on the vehicle body can be reduced as much as possible. An aerial work vehicle capable of preventing a large shock from acting on humans can be provided.

[Brief description of the drawings]

FIG. 1 is a side view of a ladder vehicle according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a right half of a boom according to the embodiment of the present invention.

FIG. 3 is an explanatory view of the expansion and contraction action of the uppermost unit boom in the embodiment of the present invention.

FIG. 4 is a side view for explaining expansion and contraction of unit booms other than the top row in the embodiment of the present invention.

FIG. 5 is a plan view for explaining an expansion / contraction action of a unit boom other than the top row in the embodiment of the present invention.

FIG. 6 is a partial side view for explaining the operation of the ladder vehicle in the embodiment of the present invention.

FIG. 7 is a side view for explaining the operation of the ladder vehicle in the embodiment of the present invention.

FIG. 8 is a side view of the basket in the use position according to the embodiment of the present invention.

FIG. 9 is a plan view of a basket in a use position according to the embodiment of the present invention.

FIG. 10 is a side view of the basket in the storage position according to the embodiment of the present invention.

11 (1) is a sectional view taken along the line XI-XI of FIG. 8, and FIG. 11 (2) is a sectional view of the basket according to the embodiment of the present invention.
View from arrow I

FIG. 12 is an explanatory diagram of a control configuration of a ladder vehicle according to the embodiment of the present invention.

FIGS. 13 (1), (2), and (3) are explanatory views of a boom extension and contraction mechanism according to the embodiment of the present invention.

14A and 14B are diagrams illustrating a relationship between time and extension speed, and FIG. 14B is a diagram illustrating a relationship between time and reduction speed in the embodiment of the present invention.

[Explanation of symbols]

 2 Body 3 Telescopic boom 3a, 3b, 3c, 3d Unit boom 9 First telescopic mechanism 10 Second telescopic mechanism 30 Basket 31 Swing shaft 51 Connecting member 55 Swing shaft 60 Winding drum 61 Wire for extension 65 Swing mechanism 66 Swing mechanism 71 Wire for reduction 75 Sensor 80 Refraction axis 81 Refraction mechanism 86a Operating body for boom extension / retraction 90 Control device 96a Operating body for storing basket 101a Operating body for preparing for getting on and off basket

[Procedure amendment]

[Submission date] September 24, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Claims (3)

[Claims] 1. A telescopic boom configured by connecting three or more unit booms vertically stacked so as to be relatively movable in a longitudinal direction of the boom, and a front end of the telescopic boom via a lowermost unit boom. A vehicle body that supports the rear end side so that it can swing up and down, and only the top unit boom of all unit booms can be extended and retracted along the boom longitudinal direction with respect to unit booms other than the top unit A first telescopic mechanism, and a second telescopic drive that allows only the unit booms other than the topmost one of all the unit booms to expand and contract with respect to each other along the boom longitudinal direction
A workbench with a telescopic mechanism, a single boom telescopic operating body whose position can be changed between an extended position, a contracted position, and a neutral position; and Outputs an extension signal to the first extension mechanism and then outputs an extension signal to the second extension mechanism. When the operating body is placed at the boom reduction position, the second extension signal is output.
A controller that outputs a contraction signal to the first telescopic mechanism after outputting the contraction signal to the telescopic mechanism, wherein the telescopic boom is driven to extend by each telescopic mechanism when the telescopic signal is output, and the output of the contraction signal is output. An aerial work vehicle characterized in that it is driven down in time. 2. When the extension speed of the uppermost unit boom is gradually reduced from the full speed state before the extension speed of the unit boom becomes zero, the extension speeds of the unit booms other than the uppermost unit are gradually increased from zero. When the expansion / contraction mechanism is controlled and the reduction speed of the unit boom other than the top stage is gradually reduced from the full speed state before the reduction speed of the unit boom becomes zero, the reduction speed of the top unit boom is gradually increased from zero. The aerial work vehicle according to claim 1, wherein each telescopic mechanism is controlled. 3. The number of the unit booms is an even number of 4 or more, and the first telescopic mechanism includes a wire for extension, a wire for reduction, and a winding drum provided on the rear end side of the lowermost unit boom. The extension wire has one end connected to the rear end side of the uppermost unit boom, the other end connected to the winding drum, and the lowermost unit boom serving as the first unit boom, with the end between both ends. The winding wire is wound around the front end of the odd-numbered unit boom and the rear end of the even-numbered unit boom other than the uppermost unit boom, and the reduction wire has one end at the rear end of the uppermost unit boom. The other end is connected to the winding drum, and the both ends of the rear end side of the odd-numbered unit boom other than the lowermost unit boom and the even-numbered unit boom other than the uppermost unit boom are connected. It is wound around the front end side, and the winding drum rotates forward. The uppermost unit boom is extended by winding up the extension wire and feeding out the reduction wire, and the uppermost unit boom is reduced by feeding out the extension wire and winding the reduction wire by reversing the winding drum. The aerial work vehicle according to claim 1 or 2, wherein the aerial work vehicle is used.