JP2021138480A - Safety apparatus of vehicle for high lift work - Google Patents

Abstract

To provide a safety apparatus of a vehicle for high lift works capable of accurately detecting barriers in the travelling direction of a steering wheel.SOLUTION: A vehicle 1 for high lift works comprises a travelling body 10 with a steering wheel 12, a lifting apparatus installed on the travelling body 10, a working platform 40 capable of moving by the lifting apparatus, a steering lever 72 operated by an operator on the working platform 40, and a steering cylinder 66 performing steering operation of the steering wheel 12. The vehicle comprises steering brackets 61L, 61R rotatably supporting the steering wheel 12 and steered with the steering wheel 12 according to the operation of the steering cylinder 66, and barrier detection sensors 91L, 91R provided on the steering brackets 61L, 61R, having a detection area extending forward in the travelling direction of the steering wheel 12, and detecting a road surface state in this detection area.SELECTED DRAWING: Figure 1

Description

The present invention relates to a safety device for an aerial work platform configured so that a running operation can be performed from a work table provided at the tip of a boom.

As an example of an aerial work platform, a traveling body capable of traveling with wheels or a crawler device, a rotating body provided on the traveling body so as to be horizontally swiveled, and the swivel body provided so as to be undulating and expandable. A self-propelled aerial work platform is known, which is equipped with a boom and a work platform that is rotatably supported at the tip of the boom. In such aerial work platforms, an operating device is provided on the workbench, and by operating the operating device, the swivel body can be swiveled, the boom can be raised and lowered, and the workbench can be swiveled (swinged). It is configured so that the traveling body can be driven as well as being operated.

In this type of aerial work platform, like the aerial work platform described in Patent Document 1, infrared sensors are provided in front of and behind the vehicle body that can be traveled by the crawler device to irradiate the ground with infrared rays. , There is one that detects the size of the step in the traveling direction of the vehicle body based on the reflected wave. Then, the traveling speed (safety speed) capable of traveling on the detected step is calculated according to the size of the detected step and the current position of the work table with respect to the vehicle body, and the current traveling speed is the safe speed. If the speed exceeds the above, deceleration control is performed so that the speed is lower than the safe speed.

Japanese Unexamined Patent Publication No. 2001-151497

By the way, in an aerial work platform traveling by wheels, when the traveling direction of the vehicle body is changed to the right or left, the steering angle of the steering wheel is displaced, but at that time, the direction of the steering wheel and the direction of the vehicle body are different. There may be a divergence. In such a case, as in the aerial work platform described in Patent Document 1, the sensor fixed to the vehicle body can be used to check the unevenness of the ground or the presence or absence of obstacles in the direction in which the aerial work platform is going. There was a risk that it would be difficult to detect the road surface condition.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a safety device for an aerial work platform that can accurately detect the road surface condition in the traveling direction of the aerial work platform. ..

In order to solve the above problems, the safety device for a high-altitude work vehicle according to the present invention includes a traveling body provided with steering wheels and capable of traveling forward and backward, and an elevating device provided on the traveling body so as to be able to move up and down (for example,). , The swivel body 20 and the boom 30) in the embodiment, a work table that can be moved by the elevating device and on which an operator can board, and a work table provided on the work table and operated by the worker who has boarded the work table. Steering operation device (for example, steering lever 72 in the embodiment) and steering actuator (for example, steering cylinder 66 and controller 50 in the embodiment) that steer the steering wheels in response to the operation of the steering operation device. A steering bracket (for example, steering in the embodiment) which is a safety device for a high-altitude work vehicle provided with Brackets 61R, 61L) and a detection region provided on the steering bracket and extending forward in the traveling direction of the steering wheels (for example, a detectable region DT in the embodiment), and a road surface state within the detection region. (For example, the right barrier detection sensor 91R and the left barrier detection sensor 91L in the embodiment) are provided.

In the aerial work platform safety device having the above configuration, it is preferable that the detection region of the road surface condition detection device extends both forward and backward in the traveling direction of the steering wheel.

Further, the safety device for the aerial work platform having the above configuration includes an alarm device (for example, the alarm device 76 in the embodiment) that issues an alarm to the operator based on the road surface condition detected by the road surface condition detection device. preferable.

According to the safety device for a high-altitude work vehicle according to the present invention, when the steering operation device provided on the work table is operated by an operator, the steering actuator is activated to steer the steering bracket together with the steering wheels. Therefore, the direction of the detection area of the road surface condition detection device extending forward in the traveling direction of the steering wheel is also displaced. Therefore, even if the steering angle of the steering wheel is displaced, it is possible to accurately detect the road surface condition in front of the steering wheel in the traveling direction.

Further, in the safety device for the aerial work platform having the above configuration, preferably, the detection area of the road surface condition detection device extends both forward and backward in the traveling direction of the steering wheels. Thereby, when the traveling body travels, it is possible to detect the road surface state in the front-rear direction in the traveling direction of the steering wheels.

Further, the safety device for the aerial work platform having any of the above configurations preferably includes an alarm device that issues an alarm to the operator based on the road surface condition detected by the road surface condition detecting device. As a result, when there is a barrier such as a step on the ground or an obstacle in the traveling direction of the steering wheel, the operator can be alerted.

It is a figure which shows the appearance of the aerial work platform which concerns on this invention, (a) is a side view of the aerial work platform, (b) is a plan view of the aerial work platform. It is a block diagram which shows the operation control composition of the said aerial work platform. It is a side view which shows the detection area of the barrier detection sensor provided in the aerial work platform. It is a top view which shows the detection area of the barrier detection sensor provided in the aerial work platform. It is a figure which shows the detection area of the barrier detection sensor provided in the aerial work platform, (a) is a front view, (b) is a rear view. It is a top view explaining that the detection area of the barrier detection sensor follows the displacement of the steering angle of a steering wheel. It is a figure which shows the other embodiment about the mounting position of the front barrier detection sensor of the aerial work platform, (a) is a plan view of a traveling body, (b) is a rear view of the aerial work platform.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As an example of the aerial work platform according to the present invention, FIG. 1 shows a self-propelled aerial work platform 1. The aerial work platform 1 is provided on a traveling body 10 configured to be able to travel, a swivel body 20 provided on the upper part of the traveling body 10 and capable of turning in the horizontal direction, and a swivel body 20 provided on the upper part of the swivel body 20 so as to be undulating. It is configured to include a boom 30 and a workbench 40 provided at the tip of the boom 30.

The traveling body 10 includes a pair of left and right steering wheels 12 (left steering wheel 12L and right steering wheel 12R) rotatably provided on the traveling body frame 11 and a pair of left and right driving wheels 13 (left driving wheel 13L and right driving wheel). It has 13R). In the present embodiment, as shown in FIG. 1A, the traveling body 10 has a movement to the left in the figure as a forward movement and a movement to the right in the figure as a backward movement. Further, the direction in which the traveling body 10 moves forward is referred to as forward, and the direction in which the traveling body 10 moves backward is referred to as backward. The steering operation (displacement operation of the steering angle) of the left steering wheel 12L and the right steering wheel 12R is configured to be performed by the steering device 60. The steering device 60 is pivotally connected to the traveling body frame 11 by a kingpin 62, and a steering bracket 61 that rotatably supports the corresponding steering wheel 12 and a force for steering the steering bracket 61 around the kingpin 62 (and by extension, It has a knuckle arm 63 for transmitting a force for steering and operating the steering wheel 12.

Here, the steering bracket 61, the kingpin 62, and the knuckle arm 63 are provided corresponding to the left steering wheel 12L and the right steering wheel 12R, respectively, and the steering bracket 61, the kingpin 62, and the knuckle arm 63 for the left steering wheel 12L are provided. With the letter "left" at the beginning of each name and "L" at the end of each code, the steering bracket 61, kingpin 62 and knuckle arm 63 for the right steering wheel 12R have each name. The letter "right" is added at the beginning and "R" is added at the end of each code. In FIG. 1B, the left knuckle arm 63L is hidden by the steering cylinder 66 and the steering arm 67, which will be described later.

The left knuckle arm 63L and the right knuckle arm 63R are connected by a tie rod 64. Specifically, one end of the tie rod 64 is rotatably fixed to the left knuckle arm 63L by the left connecting pin 65L, and the other end of the tie rod 64 is rotatably fixed to the right knuckle arm 63R by the right connecting pin 65R. ing. In this way, by connecting the left and right knuckle arms with the tie rod 64, each steering bracket is interlocked and steered (and the steering angle of the steering wheel 12 is interlocked and displaced). It has become.

Further, the left steering bracket 61L is provided with a steering arm 67 for connecting to a steering cylinder 66 which is a drive source for shifting the steering angles of the left and right steering wheels 12, and the steering cylinder 66 and the steering arm 67 are connected to each other. It is connected by a cylinder connecting pin 68. As a result, the left steering bracket 61L rotates around the left kingpin 62L according to the expansion and contraction of the rod of the steering cylinder 66. Further, the movement of the left steering bracket 61L is transmitted to the right knuckle arm 63R via the tie rod 64, and the right steering bracket 61R rotates about the right kingpin 62R in conjunction with the movement of the left steering bracket 61L. In the steering device 60 shown in FIG. 1 (b), when the cylinder rod of the steering cylinder 66 extends from the neutral position, the steering angle of the steering wheel 12 is the center line (FIG. 1) when the direction of the swivel body 20 is viewed from the work table 40. If the vehicle is displaced to the left with respect to the one-dot chain line in (b) and moves forward in this state, the traveling direction of the traveling body 10 turns to the right. Further, when the cylinder rod of the steering cylinder 66 contracts from the neutral position, the steering angle of the steering wheel 12 is displaced to the right with respect to the center line when the direction of the swivel body 20 is viewed from the work table 40, and the vehicle advances in this state. Then, the traveling direction of the traveling body 10 turns to the left.

In addition, the left steering bracket 61L is equipped with a left barrier detection sensor 91L that detects the road surface condition of the left steering wheel 12L in the traveling direction. Further, the right steering bracket 61R is provided with a right barrier detection sensor 91R for detecting the road surface condition of the right steering wheel 12R in the traveling direction. The right barrier detection sensor 91R and the left barrier detection sensor 91L will be described in detail later.

A swivel mechanism 15 is provided in the center of the upper part of the traveling body frame 11, and the swivel mechanism 15 provides the swivel mechanism 15.
The swivel body 20 is configured to swivel in the direction indicated by the arrow a in FIG. 1 (b). Further, in FIGS. 1A and 1B, a counterweight CW is attached to the front end of the swivel body 20, and the counterweight CW is provided with a barrier existing in front of the aerial work platform 1. A front barrier detection sensor 91F for detection is attached (details will be described later). Here, the "barrier" in the present embodiment includes not only unevenness of the ground but also three-dimensional structures and moving objects. In the following, when the right barrier detection sensor 91R, the left barrier detection sensor 91L, and the front barrier detection sensor 91F are collectively referred to, they are simply referred to as the barrier detection sensor 91. The barrier detection sensor 91 in the present embodiment employs LiDAR (abbreviation for Light Detection and Ranging or Laser Imaging Detection and Ranging).

The swivel mechanism 15 applies hydraulic oil to an outer ring fixed to the traveling body frame 11, an inner ring engaged with the outer ring and fixed to the swivel body 20, and various actuators (described later) provided on the swivel body 20. It has a rotary center joint (not shown) for supplying. A boom 30 is provided on the upper portion of the swivel body 20, and is rotatable (undulating) in the direction indicated by the arrow a in FIG. 1A about the pivot pin 34 as an axis. The boom 30 has a base end boom 31 pivotally connected to the swivel body 20, an intermediate boom 32 nested in the base end boom 31, and a tip boom 33, and these booms can be expanded and contracted. ing. A vertical post 37 is provided at the tip of the tip boom 33 so as to be swingable in the vertical direction by a pivot pin 33a.

A work table 40 is provided on the upper portion of the vertical post 37 so as to be swivelable (swing freely) in the direction indicated by the arrow c in FIG. 1 (b) with the pivot pin 37a as the center. The work table 40 has a substantially rectangular work floor 41 on which the worker M can board, and a handrail 42 erected around the work floor 41. The workbench 40 is provided with an operating device 70 for controlling the traveling of the traveling body 10 and the operation of the boom 30.

Next, a control device that controls the traveling of the traveling body 10 and the operation of the swivel body 20, the boom 30, and the workbench 40 based on the operation of the operating device 70 will be described with reference to FIG. This control device controls various actuators for operating the traveling body 10, the swivel body 20, the boom 30, and the workbench 40, and the operating device 70 provided on the workbench 40 described above and the various actuators described above. The hydraulic unit 80 that supplies hydraulic oil to various actuators as a drive source for the above, and the hydraulic oil that is supplied from the hydraulic unit 80 to various actuators in response to operations on various operating levers provided on the swivel body 20 and provided on the operating device 70. It is composed of a controller 50 that controls the above.

The actuators included in the aerial work platform 1 include a traveling drive actuator for driving the traveling body 10 and an upper driving actuator for driving the movements of the swivel body 20, the boom 30, and the workbench 40. There is. In the present embodiment, as the traveling drive actuators, a traveling actuator that moves the traveling body 10 forward or backward within a predetermined speed range, a steering actuator that steers the steering wheel 12, and braking that brakes the traveling body 10 during traveling. It is equipped with an actuator. The traveling motor 16 shown in FIG. 2 corresponds to the traveling actuator, the steering cylinder 66 corresponds to the steering actuator, and the brake cylinder 18 corresponds to the braking actuator. Further, as the upper drive actuator, a swivel motor 26, a boom undulating cylinder 35, a boom telescopic cylinder 36, and a swing motor 46 are provided.

The traveling motor 16 transmits the rotation of the motor shaft driven by the hydraulic pressure of the supplied hydraulic oil to the drive wheels 13 (see FIG. 1), and rotates the motor shafts in the forward or reverse direction to rotate the drive wheels 13 in the forward direction. Alternatively, it is reversed so that the traveling body 10 (see FIG. 1) is moved forward or backward. Further, the rotation speed of the motor shaft is controlled to change the traveling speed of the traveling body 10. The brake cylinder 18 is a negative brake that brakes and locks the rotation of the motor shaft of the traveling motor 16 by the force of a built-in spring to brake the rotation of the drive wheels 13 when the hydraulic oil is not supplied. In the steering cylinder 66, the tip of the cylinder rod is connected to the steering arm 67 (see FIG. 1B), and the steering wheel 12 is steered by the expansion and contraction of the cylinder rod.

The swivel motor 26 is provided on the swivel body 20, and the rotation of the motor shaft is transmitted to the inner ring engaged with the outer ring fixed to the traveling body frame 11, and the swivel motor 26 is rotated forward or reverse to rotate the swivel body 26. The 20 is turned in the clockwise or counterclockwise direction (see arrow a in FIG. 1B) with respect to the traveling body 10. The boom undulating cylinder 35 is straddled between the swivel body 20 and the boom 30, and by expanding and contracting the cylinder rod, the boom 30 is undulated in the direction of arrow a in FIG. 1A about the pivot pin 34. The boom telescopic cylinder 36 is provided in the boom 30, and by expanding and contracting the cylinder rod, the intermediate boom 32 and the tip boom 33 nestedly combined with the proximal boom 31 are expanded and contracted with respect to the proximal boom 31.

The swing motor 46 is provided on the work table 40, and the work table 40 is moved with respect to the vertical post 37 in the direction of the arrow c in FIG. 1 (b) by the rotation of the motor shaft driven by the hydraulic pressure of the supplied hydraulic oil. Allows turning operation (swing operation). An upper leveling cylinder (not shown) is straddled between the tip of the tip boom 33 and the vertical post 37. In this upper leveling cylinder, a closed circuit is formed by a hydraulic hose between the lower leveling cylinder (not shown) straddling between the base end boom 31 and the swivel body 20, and the lower leveling cylinder of the lower leveling cylinder. By expanding and contracting the upper leveling cylinder in response to the expansion and contraction operation, the vertical post 37 swings up and down with respect to the tip boom 33, and the floor surface of the work table 40 is always horizontal regardless of the undulation angle of the boom 30. It is configured to hold in.

The hydraulic unit 80 that supplies the hydraulic oil that is the drive source for operating the various actuators described above includes the engine E provided in the swivel body 20, the hydraulic pump P driven by the engine E, the hydraulic oil tank T, and the flood control. It has a control valve unit 85 that controls a supply direction and a supply amount of hydraulic oil supplied from the pump P to each hydraulic actuator. The control valve unit 85 has a plurality of control valves provided corresponding to each hydraulic actuator. These plurality of control valves include a travel control valve V1 for driving and controlling the travel motor 16, a brake control valve V2 for controlling the brake cylinder 18, a steering direction switching valve V3 for controlling the steering cylinder 66, and turning control. There are a valve V4, an undulation control valve V5, a telescopic control valve V6, and a swing control valve V7.

The operation device 70 constituting the control device shown in FIG. 2 includes a travel operation lever 71 for starting / stopping the traveling body 10, moving forward / backward, switching the traveling speed, and the like, and steering operation of the traveling body 10 (steering operation of the steering wheel 12). ), The swivel operation lever 73 that swivels the swivel body 20, the boom control lever 74 that performs the undulating and expanding / contracting operation of the boom 30, and the swing operation (swivel operation) of the workbench 40. It has a swing operation lever 75. Each of these operating levers is located in a neutral position where the lever is in a vertical position when not in operation, and can be tilted in a direction determined according to each operating lever based on this neutral position. Has been done. Further, the operation device 70 is provided with an alarm device 76, and when an alarm signal is output from the controller 50, an alarm is issued to the worker M who is on the work table 40.

The controller 50 controls each control valve in the control valve unit 85 according to the tilting operation performed by the operator with respect to each of the above-mentioned operation levers. Hereinafter, the control of each control valve according to the tilting operation of each operating lever will be described. First, the traveling operation lever 71 can be tilted in the front-rear direction from the neutral position, and when the traveling operation lever 71 is tilted forward, the controller 50 determines the speed at which the traveling body 10 corresponds to the tilt angle of the lever. The spool movement direction and valve opening degree of the travel control valve V1 are controlled so as to move forward, and the supply direction of the hydraulic oil supplied to the travel motor 16 and its flow rate are controlled. On the other hand, when the traveling operation lever 71 is tilted backward, the supply direction of the hydraulic oil supplied to the traveling motor 16 is opposite to that when the traveling operation lever 71 is tilted forward. The spool movement direction and valve opening degree of the travel control valve V1 are controlled to control the hydraulic oil supply direction and its flow rate so that the traveling body 10 retracts at a speed corresponding to the tilt angle of the lever.

Further, when the traveling operation lever 71 is tilted from the neutral state to any direction in the front-rear direction, the controller 50 opens the brake control valve V2 and supplies hydraulic oil to the brake cylinder 18. As a result, the braking lock state of the motor shaft of the traveling motor 16 is released, and the motor shaft becomes rotatable. On the other hand, when the traveling operation lever 71 is in the neutral position, or when the tilting operation is returned to the neutral position, the controller 50 closes the brake control valve V2 and operates the brake cylinder 18. Stop the oil supply. As a result, the motor shaft of the traveling motor 16 is in the braking lock state, and the rotation of the drive wheels 13 is braked.

The steering lever 72 can be tilted to the left and right from the neutral position, and the controller 50 bends to the left when the traveling body 10 advances while the lever is tilted to the left, and the lever tilts to the right. When the traveling body 10 moves forward in the operated state, the steering angle of the steering wheel 12 is displaced so as to turn to the right. The steering angle operation of the steering wheel 12 is performed by controlling the spool moving direction and the valve opening degree of the steering direction switching valve V3 by the controller 50. The swivel operation lever 73 is configured to be tilted from the neutral position to the left and right, and when the lever is tilted to the right, the swivel body 20 rotates clockwise in FIG. 1B. When the lever is tilted to the left, the swivel motor 26 controls the spool movement direction and valve opening degree of the swivel control valve V4 so that the swivel body 20 rotates counterclockwise in FIG. 1 (b). To drive.

The boom operating lever 74 is configured to be tilted in the front-rear and left-right directions from the neutral position, and when the boom operating lever 74 is tilted in the front-rear direction, the controller 50 shifts the spool movement direction of the undulation control valve V5. It switches according to the tilting direction of the lever, and controls the valve opening degree to drive the boom undulating cylinder 35 to undulate the boom 30. On the other hand, when the boom operating lever 74 is tilted in the left-right direction, the controller 50 switches the spool movement direction of the expansion / contraction control valve V6 according to the tilting direction of the operating lever, and adjusts to a predetermined valve opening degree. Under control, the boom telescopic cylinder 36 is driven to telescopically operate the boom 30. The swing operation lever 75 is configured to be tilted from the neutral position to the left and right, and when the lever is tilted to the right, the workbench 40 is tilted in the direction of the arrow C in FIG. 1 (b). The spool movement direction and the valve opening degree of the swing control valve V7 are controlled in the counterclockwise direction until the lever faces an angle corresponding to the tilt angle of the lever. Further, when the swing operation lever 75 is tilted to the left, the controller 50 causes the workbench 40 to rotate clockwise in the direction of the arrow C in FIG. 1B and according to the tilt angle of the operation lever. The spool movement direction and valve opening degree of the swing control valve V7 are controlled until the angle is turned.

Further, the controller 50 outputs an alarm signal to the alarm device 76 based on the barrier detection result by the barrier detection sensor 91. A known determination process can be adopted as the process of determining whether or not the controller 50 outputs an alarm signal. For example, work when the size (height or depth, width, etc.) of a three-dimensional object or depression detected by the barrier detection sensor 91 exceeds a predetermined value, or when an obstacle is detected by the barrier detection sensor 91. An alarm signal may be output to the alarm device 76 according to the position of the table 40 or the like.

When the traveling operation lever 71 is tilted forward, the controller 50 controls the output of an alarm signal based on the detection results of the right barrier detection sensor 91R, the left barrier detection sensor 91L, and the front barrier detection sensor 91F. When the traveling operation lever 71 is tilted backward, the controller 50 does not consider the detection result of the front barrier detection sensor 91F, and the alarm signal is based on the detection results of the right barrier detection sensor 91R and the left barrier detection sensor 91L. Output control may be performed.

Next, the mounting position of the barrier detection sensor 91 and the shape and range of the detection area will be described with reference to FIGS. 3 to 6. Here, in FIGS. 3 to 6, the same components as those shown in FIGS. 1 (a) and 1 (b) are designated by the same reference numerals, and detailed description thereof will be omitted. Further, since the shapes of the detection areas of the right barrier detection sensor 91R and the left barrier detection sensor 91L are the same, both the left barrier detection sensor 91L and the right barrier detection sensor 91R are collectively described below, respectively. It will be described as 91L. First, as shown in FIG. 3, the shape of the detection region of each of the barrier detection sensors 91R and 91L is a semicircle with a radius of r1 [m] (that is, the viewing angle is 180 °), and the center point of the detection region is high. It coincides with the position of the rotation axis of the steering wheel 12 in the front-rear direction of the aerial work platform 1. Therefore, the detectable region DT (the region shown by thin hatching in FIG. 3) in which the barrier can be detected by the barrier detection sensors 91R and 91L extends to both the front and the rear of the steering wheel 12. However, a part of the detectable region DT becomes a blind spot blocked by the steering wheels 12 and the driving wheels 13, and becomes an undetectable region ND (the region shown by dark hatching in FIG. 3) in which the barrier cannot be detected.

As shown in FIG. 4, the detection areas (areas indicated by thin hatching) of the barrier detection sensors 91R and 91L are the center line TC in the tire width direction of the steering wheel 12 (hereinafter, simply referred to as “center line TC”). Located on top. As shown in FIG. 5A, the barrier detection sensors 91R and 91L are fixed to the left and right steering brackets 61R and 61L (see FIG. 1B) by the rod-shaped left and right fixing members 69R and 69L, respectively. ing. Further, the height of the mounting position of each of the barrier detection sensors 91R and 91L is set to the highest position within the range of not hitting the bottom surface of the swivel body 20 and the protrusions from the bottom surface. In addition, in order to detect a barrier on the course of the steering wheel 12, the main body of each barrier detection sensor 91R, 91L has a corresponding steering so that the detectable region DT is within the range including the tire width of the steering wheel 12. It is fixed to the fixing members 69R and 69L by tilting in the direction of the steering wheel 12 from directly above the bracket 61. By attaching the barrier detection sensors 91R and 91L to the corresponding steering bracket 61 in this way, when the steering angle of the steering wheel 12 is displaced due to the operator performing the steering operation with the steering lever 72, it is detected accordingly. The direction of the possible region DT will also be displaced.

Next, with reference to FIG. 6, the positional relationship between the locus of the steering wheel 12 and the direction of the detectable region DT will be described. FIG. 6A shows a plan view of the traveling body 10 when the aerial work platform 1 retreats straight, and FIG. 6B shows a plan view of the traveling body 10 when the aerial work platform 1 retreats while turning to the right. Shown. Further, the reference numeral RM indicates a position where the turning mechanism 15 is provided on the traveling body frame 11.

When the operator tilts the traveling operation lever 71 backward while keeping the steering lever 72 in the neutral position, the aerial work platform 1 retracts straight as shown in FIG. 6A, and the left steering wheel 12L The locus TL and the locus TR of the right steering wheel 12R (the portion indicated by the broken line) draw a straight line. At this time, since the left barrier detection sensor 91L and the right barrier detection sensor 91R include the locus TL and the locus TR in the detectable region DT, respectively, each barrier detection sensor detects the barrier on the course of the steering wheel. can do.

Further, as shown in FIG. 6B, when the operator tilts the steering lever 72 to the right and tilts the traveling operation lever 71 to the rear, the left steering wheel 12L and the right steering wheel 12R are tilted. The rudder angle is displaced to the left, and the trajectories TL and TR of each steering wheel draw a curve that turns to the right. At this time, since the angles of the left and right steering brackets 61L and 61R are displaced along with the steering angles of the steering wheels, the course of the steering wheels 12 is included in the detectable region DT of the left barrier detection sensor 91L and the right barrier detection sensor 91R. Will be. Therefore, the left barrier detection sensor 91L and the right barrier detection sensor 91R can accurately detect the barrier in the traveling direction of the aerial work platform 1.

Next, as shown in FIG. 3, the front barrier detection sensor 91F is attached downward at the upper and rear ends of the counterweight CW of the swivel body 20 so that the detectable region DT faces the ground GND. At this time, the front barrier detection sensor 91F is attached so that the angle formed by the detectable region DT and the ground GND is not vertical but tilts forward from the front end of the aerial work platform 1. Further, as shown in FIG. 5B, the shape of the detection region of the front barrier detection sensor 91F is a semicircle with a radius of r2 [m] (that is, the viewing angle is 180 °), and the center point of the detection region is high. It is located on the center line C in the vehicle width direction of the aerial work platform 1. By attaching the front barrier detection sensor 91F to a high position of the counterweight CW in this way, the barrier in front of the aerial work platform 1 can be detected in a wide range. Further, when the worker M on the work platform 40 runs the aerial work platform 1 while the work table 40 is in a high place, the swivel body 20 detects a barrier within a blind spot. An alarm can be issued to the worker M.

The front barrier detection sensor 91F is not limited to the counterweight CW, and may be attached to the front of the traveling body frame 11 as shown in FIG. Here, FIG. 7A shows a plan view of the traveling body frame 11, and FIG. 7B shows a rear view of the aerial work platform 1. As shown in these figures, the front barrier detection sensor 91F is attached to the front end of the traveling body frame 11, and is attached slightly downward so that the detectable area extends to the ground. When the front barrier detection sensor 91F is attached to the traveling body frame 11, the area where the barrier can be detected is narrower than when it is attached to the counterweight CW, but it is not affected by the turning of the turning body 20. , The barrier in the traveling direction of the traveling body frame 11 can always be detected.

The present invention is not limited to the above embodiment, and can be appropriately improved as long as it does not deviate from the gist of the present invention. For example, in the present embodiment, LiDAR is adopted as the barrier detection sensor 91, but the type of sensor is not limited to this, and other types of sensors such as an infrared sensor and an ultrasonic sensor may be used. Further, the shape of the detection region of the barrier detection sensor 91 is not limited to the semicircular shape as in the present embodiment, and may be a shape corresponding to various sensors. Further, for example, when the viewing angle of the detection area is a fan shape of less than 180 ° and the detection range cannot cover the front-rear direction of the steering wheel 12 as shown in FIG. 3, the vehicle in front (aerial work platform). The barrier may be detected only in either the rear (direction in which 1 moves backward) or the rear (direction in which the aerial work platform 1 moves forward) (preferably in front). Further, when the controller 50 outputs an alarm signal to the alarm device 76, the traveling control valve V1 and the brake control valve V2 are also controlled so that the traveling speed of the aerial work platform 1 becomes a specific speed (for example,). The vehicle may be decelerated or stopped running until the "safe speed" described in Patent Document 1 is reached.

Further, in the present embodiment, as the traveling drive actuator for controlling the traveling of the traveling body 10, an actuator having a hydraulic drive source such as the traveling motor 16, the steering cylinder 66, and the brake cylinder 18 is used. However, various actuators such as an electric motor and an internal combustion engine may be used. Further, in the present embodiment, the steering operation is performed by the steering lever 72, but the steering operation may be performed by the steering dial. Further, in the above-described embodiment, the aerial work platform provided with the telescopic boom capable of undulation, expansion and contraction, and swivel movement has been described as an example. Alternatively, it may be an aerial work platform equipped with a bending / stretching boom or the like.

1 Aerial work platform 10 Traveling body 12 Steering wheel 20 Swing body 30 Boom 40 Worktable 50 Controller (steering actuator control device)
60 Steering device (detection area tracking device)
61L Left Steering Bracket 61R Right Steering Bracket 66 Steering Cylinder (Steering Actuator)
69 Mounting member 70 Operation device 72 Steering lever (steering operation device)
76 Alarm device 91L Left barrier detection sensor 91R Right barrier detection sensor 91F Front barrier detection sensor

Claims (3)

A traveling body equipped with steering wheels and capable of traveling forward and backward,
An elevating device provided on the traveling body so as to be able to elevate,
A workbench that can be moved by the lifting device and that can be boarded by workers,
A steering operation device provided on the work table and operated by an operator on the work table.
A safety device for aerial work platforms, comprising a steering actuator that steers the steering wheels in response to an operation of the steering operation device.
A steering bracket that rotatably supports the steering wheel and is steered together with the steering wheel in response to the operation of the steering actuator.
A road surface condition detection device provided on the steering bracket, having a detection region extending forward in the traveling direction of the steering wheel, and detecting a road surface condition in the detection region.
A safety device for aerial work platforms, which is characterized by being equipped with. The safety device for aerial work platforms according to claim 1, wherein the detection area of the road surface condition detecting device extends both forward and backward in the traveling direction of the steering wheel. The safety device for aerial work platforms according to claim 1 or 2, further comprising an alarm device that issues an alarm to an operator based on the road surface condition detected by the road surface condition detecting device.

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