JP2013052949A - Safety device for vehicle for high lift work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety device for a vehicle for high lift work, which secures safety by preventing such an accident that a worker is caught between a work platform and a structure.SOLUTION: The safety device includes a regulation determination portion 73 that, when it is detected that a worker rides on a work platform, compares a separation distance detected by a ranging sensor 60 with a preset distance threshold value, causes a warning device 56 to perform warning operation when the separation distance is equal to or less than a first distance threshold value, and regulates the operation of a lifting device in a direction for approaching the work platform to an object when the separation distance is equal to or less than a second distance threshold value smaller than the first distance threshold value.

Description

The present invention relates to a safety device for an aerial work vehicle provided with a lifting device that lifts and lowers a work board for worker boarding to a desired height.

The aerial work platform includes a lifting device (e.g., a boom device) disposed on a movable vehicle body so as to be movable up and down, and a work board for worker boarding provided at a tip portion of the lifting device, It is a vehicle that is configured to move the work platform to an arbitrary high position by operating a lifting device by operating an operation device provided on the work table by an operator boarded on the work table. It is used for work at various heights such as building and ship construction, highway construction, etc. (see, for example, Patent Document 1).

JP 2009-208913 A

By the way, when working at a high place in a work site such as indoors or in a road tunnel,
There is a limit to the work height at which work can be performed safely in relation to structures such as ceilings and beams installed above. Under such circumstances, when an operation is performed to move the workbench upward, if the operator does not notice the presence of the upper structure or accidentally brings the workbench too close to the upper structure, There is a risk that an operator may be caught between the work table and the upper structure. On the other hand, in order to avoid such a situation, it is necessary for the worker to pay careful attention to the operation of moving the work table upward and to make safety the highest priority, but always be aware of the upper structure. There is a problem that attention is distracted with respect to the original work and work efficiency is lowered.

The present invention has been made in view of such a problem, and prevents an accident in which an operator is caught between a workbench and a structure without incurring a reduction in work efficiency, thereby improving safety. An object of the present invention is to provide a safety device for an aerial work vehicle that can be secured.

In order to solve the above problems, a safety device for an aerial work vehicle according to the present invention includes a travelable vehicle body, a lifting device (for example, a boom 30 in the embodiment) attached to the vehicle body so as to be lifted and lowered, and a lifting device. A work table that is attached to the operator and on which an operator can board, operating means for operating the lifting device (for example, the operating device 50 in the embodiment), and operation of the lifting device based on an operation signal from the operating means Operation control means (for example, the valve control unit 71 of the controller 70 in the embodiment), worker boarding detection means for detecting whether or not the worker is on the worktable, and an object above the worktable Distance detecting means for detecting a separation distance up to (for example,
In the embodiment, the distance measuring sensor 60), alarm means for performing a predetermined alarm operation (for example, the alarm device 56 in the embodiment), and worker boarding detection means detect that the worker is on the work table. When the distance detection unit compares the separation distance detected by the distance detection means with a preset distance threshold, the separation distance is a first distance threshold (for example, the warning distance T in the embodiment).
D ₁ ) If the alarm means is activated when it is equal to or less than D ₁ ), and the separation distance is equal to or less than a second distance threshold (for example, the dangerous distance TD _{2 in the} embodiment) that is smaller than the first distance threshold And a restriction judging means (eg, a restriction judging unit 73 of the controller 70 in the embodiment) for restricting the operation of the elevating device in the direction in which the work table approaches the object.

In the safety device for an aerial work vehicle having the above-described configuration, the worker boarding detection means includes a safety belt attached to the worker himself / herself on the work table, and a safety belt lock provided on the work table. means(
For example, it is preferable to include safety band locking detection means (for example, a safety band locking detector 19 in the embodiment) that detects whether or not the hook locking bracket 17 is locked in the embodiment. .

In the safety device for an aerial work vehicle having the above-described configuration, distance detection means (for example, the distance measuring sensor 160 in the embodiment) is provided in a helmet worn by an operator, and the distance detection means is used for work on a work table. It is preferable to detect the separation distance to the object above the person.

In addition, in the safety device for an aerial work vehicle having the above-described configuration, when an operator gets on the work table,
Work is performed by distance detection means (for example, the distance measurement sensor 60 in the embodiment) provided on the work table and distance detection means (for example, the distance measurement sensor 160 in the embodiment) provided in the helmet worn by the worker. You may comprise so that the separation distance to the target object above a stand may be detected, respectively.

A safety device for an aerial work vehicle according to the present invention, when it is detected that an operator is on the workbench, a separation distance to an object above the workbench detected by the distance detection means, Two distance thresholds set in advance are compared with each other, and when the separation distance reaches the first distance threshold, the alarm device is activated to alert the operator, and the separation distance is When the distance threshold value of 2 is reached, the operation of the lifting device is restricted. Therefore, when an operator is on the work table, it is possible to prevent the work table and the worker who is on it from getting too close to the object in an unintended state. It is possible to prevent the worker from being caught between the structures and ensure the safety of the worker, and the worker needs to consider the distance to the object excessively as before. Therefore, it is possible to concentrate on the original work and reduce the burden on the operator and improve the work efficiency.

Further, the worker boarding detection means detects whether a safety belt attached to the worker himself / herself on the worktable and whether the safety belt is locked by the safety belt locking means provided on the worktable. By comprising safety band locking detection means, it is possible to detect not only the operator's boarding on the workbench but also the mooring state of the worker's safety belt. Both accidents can be prevented and work safety can be further enhanced.

Also, by providing distance detection means on the helmet worn by the worker, the worker's working posture (for example, standing state, middle waist state, bent state) and the separation distance according to the worker's height are detected. Therefore, the safety of the worker can be further improved.

Further, when an operator gets on the workbench, both the distance detection means provided on the workbench and the distance detection means provided on the helmet worn by the worker up to the object above the workbench. By adopting a configuration that detects the separation distances, the work table and the position of the operator, the state of the object, the condition of the object, etc. Can be detected in accordance with the situation, and the work can be performed safely without hesitation of an unknown object existing in the moving direction.

It is a block diagram which shows the structure of the safety device which concerns on 1st Embodiment of this invention. It is a side view which shows the aerial work vehicle carrying the said safety device. It is a fragmentary sectional view which shows the work bench | platform of the said aerial work vehicle. It is a front view which shows the hook latching metal fitting with which the said work bench | platform is equipped. It is a perspective view which shows the operating device with which the said workbench is equipped. It is a top view which shows arrangement | positioning of the ranging sensor with which the said workbench is equipped. It is a schematic diagram showing the relationship between the separation distance and the distance threshold, where (a) is warning distance <separation distance, (b) is danger distance <separation distance ≦ warning distance, and (c) is separation distance ≦ danger distance. Indicates. It is a flowchart which shows the control content of the said safety device. It is a block diagram which shows the structure of the safety device which concerns on 2nd Embodiment of this invention. It is a side view which shows arrangement | positioning of the ranging sensor with which a helmet is provided in 2nd Embodiment. It is a schematic diagram which shows the relationship between a separation distance and a distance threshold value in 2nd Embodiment, (a) is warning distance <separation distance, (b) is danger distance <separation distance <warning distance, (c) is separation distance <=. Indicates the danger distance.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows an aerial work vehicle (boom type work vehicle) to which the safety device according to the present embodiment is applied. First, an overview of the overall configuration of the aerial work vehicle 1 will be described with reference to FIG.

The aerial work vehicle 1 includes a vehicle body 10 of a truck-type vehicle that includes traveling tire wheels 11, 11,... That can be operated by a driving cab 12, and a swivel base 20 provided on the vehicle body 10.
A telescopic boom (hereinafter simply referred to as a “boom”) 30 having a base end portion supported via a foot pin 22 on an upper portion of a support column 21 extending upward from the swivel base 20; And a work board 40 for boarding an operator attached to the tip.

The swivel base 20 is attached to the rear part of the vehicle body 10 so as to be rotatable 360 degrees around the vertical axis. A turning motor 23 is provided inside the vehicle body 10. By turning the turning motor 23, the turntable 20 can be horizontally turned through a gear (not shown). The boom 30 has a configuration in which a proximal boom 30a, an intermediate boom 30b, and a distal boom 30c are assembled in a telescopic manner, and the boom 30a is retracted from the proximal boom 30a by an expansion / contraction operation of an expansion / contraction cylinder 31 provided therein. The intermediate boom 30b and the tip boom 30c can be moved relative to each other so that the entire boom 30 can be expanded and contracted in the axial direction. Also, the proximal boom 30
A hoisting cylinder 24 is straddled between a and the support column 21 of the swivel base 20. By operating the hoisting cylinder 24 to expand and contract, the entire boom 30 can be raised and lowered within the upper and lower surfaces. Here, the boom 30 has a three-stage expansion / contraction configuration, but may have a two-stage or four-stage or more multi-stage expansion / contraction configuration.

A boom head 32 is attached to the distal end portion of the distal end boom 30c, and the lower end portion of the vertical post 33 is pivotally supported by the boom head 32. The vertical post 33 is controlled to swing by a leveling device (not shown) disposed between the tip of the tip boom 30c or between the boom head 32 and the vertical post 33, and the vertical post 33 is controlled regardless of whether the boom 30 is raised or lowered. The post 33 is always held in a vertical posture.

The work table 40 has a substantially box shape with an upper end opened, and is rotatably attached to the upper end portion of the vertical post 33 via a work table holding bracket 41 that protrudes to the outside. A swing motor 42 is provided inside the worktable holding bracket 41, and the entire worktable 40 is swung around the vertical post 33 (horizontal swivel motion) by rotating the swing motor 42. be able to. Here, since the vertical post 33 is always maintained in the vertical posture as described above, as a result, the floor surface of the work table 40 is always held horizontally regardless of the undulation angle of the boom 30.

An operator (indicated by reference symbol “OP” in FIG. 3) on the work table 40 wears a body holder called a so-called safety belt. As shown in FIG. 3, the safety belt 90 includes a belt 91 worn by an operator, a rope 92 having one end attached to the belt 91, and a hook attached to the other end of the rope 92. 93. Meanwhile, work table 40
A hook locking bracket 17 is fixed to the worktable holding bracket 41, and a hook locking hole 17a capable of locking the hook 93 of the safety belt 90 is opened at the center thereof. When the operator gets on the work table 40, the worker always keeps the hook 93 of the safety belt 90 locked in the hook locking hole 17 a of the hook locking bracket 17. As a result, the operator's body is moored on the work table 40 and is prevented from accidentally falling from the work table 40. Further, the rope 92 of the safety belt 90 is formed of an insulating material, which insulates electrical continuity from the work table 40 side, thereby preventing an operator's electric shock.

Further, as shown in FIG. 4, the hook locking bracket 17 has a non-detection position that covers a part of the hook locking hole 17a and a detection position that is completely opened without covering the hook locking hole 17a. There is provided a hook detecting operation piece 18 swingable around a hinge 18a between the spring 1 and the spring 1a.
8b is always urged in the non-detection position direction (the direction opposite to the arrow R direction shown in FIG. 4). The hook detecting operation piece 18 is locked to the hook locking bracket 17 of the work table 40 at the end of the safety band 90 by a later-described safety band locking detector 19 provided on the side of the hook locking hole 17a. It is used when detecting whether or not

Further, the work table 40 is provided with an operation device 50 that is operated by an operator who has boarded the work table 40. Here, a movement operation of the work table 40, that is, a boom for performing the raising / lowering, extending / contracting and turning operations of the boom 30 is performed. An operation lever 51 and a work table operation lever 52 for swinging the work table 40 are provided (see FIG. 5). An operator who has boarded the work table 40 operates the boom operation lever 51 and the work table operation lever 52 to extend and retract the hoisting cylinder 24, extend and retract the expansion cylinder 31, rotate the turning motor 23, and Swing motor 4
Each of the two rotation operations can be performed. Here, the boom operation lever 51 can be twisted in both the left and right directions around the axis in addition to the tilting operation in the front and rear direction and the left and right direction. Operation (undulation cylinder 24
The boom operation lever 51 is tilted in the left-right direction.
Of the boom operation lever 51 is equivalent to a turning operation of the boom 30 (the turntable 20) (a rotation operation operation of the turning motor 23). The work table operation lever 52 can be tilted in the left-right direction, and the tilt operation in the left-right direction of the work table operation lever 52 can be performed by swinging the work table 40 (swing motor 42).
Rotation operation). The pivoting operation of the boom operation lever 51 around the axis is not only a mode in which the entire lever is twisted in the direction around the axis, but also a mode in which only the grip (knob) provided at the tip of the lever is twisted in the direction around the axis. included.

As shown in FIG. 1, the hoisting cylinder 24 is connected to the telescopic cylinder 3 via the first control valve V1.
1 is discharged from a hydraulic pump P provided on the traveling body 10 via a second control valve V2, to the swing motor 23 via a third control valve V3, and to the swing motor 42 via a fourth control valve V4. The hydraulic oil (pressure oil) is supplied, and the undulating cylinder 24, the telescopic cylinder 31, the swing motor 23, and the swing motor 42 (hereinafter collectively referred to as “hydraulic actuator”). Are operated at directions and speeds corresponding to the drive states of the spools of the corresponding control valves V1, V2, V3, and V4. In addition, the hydraulic pump P is the traveling body 1
Operation of a predetermined hydraulic pressure and flow rate is rotationally driven using the driving force of a traveling engine E (see FIG. 1) taken out by a power take-off mechanism PTO (see FIG. 1) provided at the front of 0 Discharge the oil. Here, the drive direction of each spool of the control valves V1 to V4 is related to the drive direction (extension / contraction direction or rotation direction) of the corresponding hydraulic actuator, and the drive amount of each spool is the hydraulic oil supplied to the corresponding hydraulic actuator. It relates to the flow rate (flow rate per unit time), that is, the operating speed of each hydraulic actuator. Therefore, each control valve V1-V4
When the spool driving direction is reversed, the operating speed of the corresponding hydraulic actuator is reversed, and the operating speed of the corresponding hydraulic actuator increases as the spool driving amount in each of the control valves V1 to V4 increases.

A controller 70 (see FIG. 1) is installed in the traveling body 10, and the controller 7
The zero valve control unit 71 drives the spools of the control valves V1 to V3 based on operation signals output by operating the boom operation lever 51 in the respective directions (front-rear direction, left-right direction, and axial direction). Each spool of the control valve V4 is driven based on the operation signal output by operating the worktable operation lever 52. Here, the operation state (operation direction and operation amount) of the boom operation lever 51 and the work table operation lever 52 is determined by lever operation state detectors 51a and 52a (for example, configured by a potentiometer) provided in the operation device 50. The detected signal is input to the valve control unit 71 of the controller 70 as an operation signal corresponding to the operation direction and the operation amount of the operation levers 51 and 52.

With such a configuration, an operator who has boarded the work table 40 operates the boom operation lever 51 to cause the boom 30 to move up and down, extend and retract, or operate the work table operation lever 52 to hang the work table 40 on the neck. By swinging, it is possible to move the work table 40 on which it is boarded to a desired position. Outrigger jacks 13 are provided at four places on the front, rear, left and right of the traveling body 10.
The traveling body 10 can be supported in a lifted state by projecting the outrigger jack 13 downward and grounding it. In addition, each outrigger jack 13 can be extended to the side (vehicle width direction) of the traveling body 10, thereby obtaining a stable posture of the traveling body 10. The operation of the outrigger jack 13 is performed by operating a jack operating lever 14 provided behind the traveling body 10. In addition,
A PTO operation lever 15 for turning on / off the power take-off mechanism PTO (driving or stopping the hydraulic pump P) is provided at a driver seat in the driving cab 12 (see FIG. 1).

Further, the floor surface of the work table 40 is provided with a pedal-type foot switch 53 (see FIG. 1) that is operated by an operator who has stepped on the work table 40 with his / her foot.
3 is also a part of the operating device 50). The foot switch 53 is a switch that enables each hydraulic actuator to be operated by operating the boom operation lever 51 or the work table operation lever 52 only when it is being operated. Operation state)
Then, a signal (referred to as a “switch operation signal”) is output, and no switch operation signal is output in the off state (non-operation state) in which the depression is released. As shown in FIG. 1, the switch operation signal output from the foot switch 53 is input to the controller 70, and the valve control unit 71 of the controller 70 only outputs the switch operation signal from the foot switch 53. The operation signal output by operating the boom operation lever 51 and the operation signal output by operating the worktable operation lever 52 are treated as valid. Therefore,
Even if the operator on the work table 40 operates the boom operation lever 51 or the work table operation lever 52, this must be performed in a state where the foot switch 53 is depressed (the foot switch 53 is turned on). Since the operation is not effective, the operator must first depress the foot switch 53 and then operate the boom operation lever 51 or the worktable operation lever 52. Therefore, in the following, for convenience of explanation, when the boom operation lever 51 or the workbench operation lever 52 is operated, it is assumed that the foot switch 53 is always depressed and the description thereof is omitted.

The aerial work vehicle 1 having such a configuration is provided with a safety device for preventing an accident in which an operator is caught between the work table 40 and the upper structure during the aerial work. Now, the configuration of the safety device will be described in detail by exemplifying two embodiments below.

First, the configuration of the safety device according to the first embodiment will be described with additional reference to FIGS. 1 and 6 to 7. As shown in FIG. 1, the safety device of the first embodiment includes a safety band locking detector 19, a distance measuring sensor 60, a controller 70, an alarm device 56, and a release switch 54 in addition to the operation device 50 described above. Configured. Since the operation levers 51 and 52 of the operation device 50 and the valve control unit 71 of the controller 70 have been described above, description thereof will be omitted below.

The safety band locking detector 19 is for detecting whether or not the hook 93 of the safety band 90 is locked to the hook locking bracket 17, and is constituted by a so-called limit switch (
However, the present invention is not limited to this. For example, a photoelectric sensor or a proximity switch may be used. When the hook 93 of the safety band 90 is locked in the hook locking hole 17a, the safety band locking detector 19 swings in the direction of arrow R shown in FIG. As a result, the switch operation piece 19a is pushed upward to output an ON signal. On the other hand, as described above, the hook detecting operation piece 18 is always urged in the non-detection position direction (the direction opposite to the arrow R direction) by the spring 18b.
Is not locked in the hook locking hole 17a, an off signal is output. The safety band locking detector 19 and the controller 70 are electrically connected, and such an on / off signal of the safety band locking detector 19 is input to the controller 70. In the present embodiment, the operator boarding detection means includes a safety band 90, a hook locking bracket 17 and a safety band locking detector 19. In the safety band locking detector 19, the hook 93 of the safety band 90 is hooked. By detecting whether or not it is locked to the locking bracket 17, it is indirectly detected whether or not an operator is on the work table 40.

The distance measuring sensor 60 uses a laser beam, an infrared ray, an ultrasonic wave, or the like to detect the distance between the object to be detected (for example, a structure installed above the work site) K in a non-contact manner. In this embodiment, a reflective distance measuring sensor that has a light projecting unit (light projecting element) and a light receiving unit (light receiving element) in the sensor head and performs distance measurement by a triangulation system is illustrated. . The distance measurement is not limited to the triangulation method. For example, the distance is measured based on the elapsed time from when the light emitted from the light projecting unit is reflected by the object K and returns to the light receiving unit. It may be a method. In addition, the distance measuring sensor 60 is preferably one that enables long-distance measurement and is excellent in environmental resistance (such as dust proof, drip proof, vibration resistance, and shock resistance).

As shown in FIG. 6, the distance measuring sensor 60 is attached to the four corners of the outer edge of the upper opening of the work table 40 (that is, four places are installed in this embodiment), and is detected by the distance measuring sensor 60. The distance between the sensor head and the target object K can be regarded as a separation distance D between the work table 40 and the target object K substantially. Each distance measuring sensor 60 has an external load /
In order to make it difficult to receive an impact, it is attached to the work table 40 while being accommodated and held in a square tube-shaped mounting bracket 61 whose opening is directed in the detection direction (vertically upward). The distance measuring sensor 60 and the controller 70 are electrically connected, and the detection value (detection information of the separation distance D) detected by each distance measuring sensor 60 is input to the controller 70.

The controller 70 includes a valve control unit 71, a storage unit 72, a regulation determination unit 73, and a regulation release unit 74.

The storage unit 72 has a separation distance for determining whether or not the position of the work table 40 (and the worker on the work table) is too close to the object K (a risky relationship). Two distance thresholds for D, that is, warning distance TD ₁ as the first distance threshold and danger distance TD ₂ as the second distance threshold are preset and stored (provided that “danger distance TD ₂ <warning distance TD”).
₁ ”). The distance threshold (warning distance TD ₁ , danger distance TD ₂ ) may be set arbitrarily. For example, the operator may directly input a distance threshold value using a numerical key or the like, or may select from a plurality of preset values stored in advance. The distance threshold may be automatically calculated. Thereby, since the distance threshold value can be arbitrarily set according to the state of the site where the work is performed and the height of the worker, it is possible to improve workability and safety.

The restriction determination unit 73 detects that the hook 93 of the safety band 90 is locked to the hook locking bracket 17 (that the operator is on the work table 40) in the safety band locking detector 19. In other words, when an ON signal is input from the safety band locking detector 19, the storage unit 7
2 is compared with the detected distance (distance D between the work table 40 and the object K at the present time) input from each distance measuring sensor 60 and the warning distance TD ₁ and the dangerous distance TD ₂ stored in FIG. do it(
7), it is determined whether or not there is a possibility that the work table 40 (and the worker who has boarded it) is too close to the object K. In the restriction determination unit 73, the comparison calculation is performed in parallel for each detection value of the four distance measuring sensors 60, and the detection value (four positions) of any one of the distance measuring sensors 60 is detected. When it is determined that the separation distance D) indicating the minimum value among the certain distance measurement sensors 60 is equal to or less than the warning distance TD ₁ and the danger distance TD ₂ , the boom 3 exemplified below is used.
The operation restriction of 0 and the alarm operation by the alarm device 56 are executed.

First, as a first stage, as shown in FIG. 7B, the restriction determination unit 73 determines that the separation distance D is equal to or less than the warning distance TD ₁ (TD ₂ <D ≦ TD ₁ ). When the object K is closer than the distance TD ₁ , an alarm activation signal is output to the alarm device 56 provided in the operation device 50 to give an alarm to the worker. For example, as shown in FIG. 5, the alarm device 56 is configured by an alarm buzzer 57, an alarm lamp 58, an alarm display 59, etc. Say anything you want. The restriction determination unit 73 self-holds the alarm activation signal while the separation distance D is equal to or less than the warning distance TD ₁ , that is, until the work table 40 is further away from the object K than the warning distance TD _1. Then, the alarm operation by the alarm device 56 is continued.

Subsequently, as a second stage, as shown in FIG. 7C, the restriction determination unit 73 determines that the separation distance D is equal to or less than the dangerous distance TD ₂ (D ≦ TD ₂ ), that is, the work table 40 is at the dangerous distance. When the object is closer to the object K than TD _2, a restriction signal for restricting the raising / lowering, extending / contracting and turning operation of the boom 30 is output to the valve control unit 71 to restrict the operation of the boom 30 (ie, the boom 30). 30
Forcibly stop). At this time, the valve control unit 71 that has received the restriction signal from the restriction determination unit 73 ignores the operation signal even if the boom 30 is operated (or the boom 3
By shutting off the pressure oil supply to each hydraulic actuator so that the zero operation is not performed)
The operation of the boom 30 is restricted. In addition, the regulation determining unit 73 (the separation distance D is the warning distance TD ₁
The alarm operation signal is continuously held and the alarm operation by the alarm device 56 is continued as it is (because the following state continues).

The restriction release unit 74 is electrically connected to a release switch 54 (consisting of a “momentary switch”) provided in the operation device 50, and the release switch 54 is turned on by an operator who has boarded the work table 40. An ON signal (regulation release command signal) is input only during operation (when the release switch 54 is released, it automatically returns to the neutral position and is turned off). In a state where the operation of the boom 30 is restricted (a state in which a restriction signal is output from the restriction determination unit 73), the restriction release unit 74 receives a restriction release command signal output by turning on the release switch 54. Only when the operation of the boom 30 is performed so as to move the work table 40 away from the object K (that is, in the downward direction), a restriction release signal is output to the restriction determination unit 71 (that is, The operation restriction of the boom 30 is released), and the operation of the boom 30 according to the operation state is permitted. On the other hand, when the operation of operating the boom 30 to move the work table 40 in the direction in which the work table 40 approaches the object K (that is, the ascending direction) is performed as the other operation of operating the boom 30, for example, Since it is not preferable from the viewpoint of safety, the restriction release signal is not output to the restriction determination unit 73 and the operation restriction of the boom 30 is continued.

At this time, the restriction release unit 74 is a lever operation state detector (potentiometer) 51a.
Based on the operation state (operation direction) of the boom operation lever 51 detected in step 4.
It is determined whether or not the operation of operating the boom 30 to move 0 in the direction of moving away from the object K (downward direction) has been performed. The operation of operating the boom 30 in the direction in which the work table 40 is moved away from the object K is, for example, the operation of inclining the boom 30 (the operation of retracting the hoisting cylinder 24) or the operation of retracting the boom 30 (the operation of the telescopic cylinder 31). (Shrinking operation)), or an operation of moving the work table 40 linearly in the downward direction by combining the above-described inclining operation and contracting operation of the boom 30. In the present embodiment, the operation restriction of the boom 30 is released when the operation of the boom 30 is performed such that the work table 40 is moved in the direction of moving away from the object K (downward direction). Even when an operation operation of the boom 30 that moves the base 40 in the direction in which the object 40 approaches the object K (upward direction) is performed, the operation restriction of the boom 30 may be released. In this case, alerting that the boom 30 is approaching the object K by changing the operation speed of the boom 30 to a low speed operation slower than normal, changing the alarm sound of the alarm operation by the alarm device 56, or both are performed. You can do it. Thereby, since it can approach to the target object K by a worker's judgment, workability | operativity improves without impairing safety.

In the aerial work vehicle 1 equipped with the safety device having such a configuration, a desired aerial work (for example,
To perform maintenance work in the road tunnel, an operator who has driven the aerial work vehicle 1 and arrived at the intended work site turns on the PTO operation lever 15 provided in the driver's seat in the driving cab 12. After operating and driving the hydraulic pump P by the driving force of the engine E taken out by the power take-off mechanism PTO, the jack operating lever 14 at the rear of the vehicle body 10 is operated to project each outrigger jack 13 to the grounded state. The vehicle body 10 is brought into a stable posture, and the vehicle body 1
Enter the work table 40 in the retracted state from 0. And the safety belt 9 wrapped around the worker's body
After the zero hook 93 is locked in the hook locking hole 17 a of the hook locking bracket 17 of the work table 40, the boom operating lever 51 in the operating device 50 is operated, and the boom 30 is raised, retracted, extended and turned. Alternatively, the work table operation lever 52 is operated to swing the work table 40. Thereby, the worker who has boarded the work table 40 can move the work table 40 to an arbitrary high position by operating his own lever and can perform a desired work at a high place.

Next, the control contents of the safety device when moving the work table 40 as described above will be described with reference to FIG.
This will be described below with additional reference to the flowchart shown in FIG.

First, in the restriction determination unit 73 of the controller 70, based on the on / off signal input from the safety band locking detector 19, whether or not the worker's safety band 90 is moored on the work table 40, that is, It is determined whether or not the worker is on the work table 40 (step S10).
1). When an off signal is input from the safety band locking detector 19 (when the safety band 90 is not moored), a negative determination is made in this step S101, and the safety band locking detector 1
When the ON signal is input from the safety band locking detector 19, the process proceeds to the next step.

When the boom operation lever 51 is operated by the operator, the boom 30 is operated at an operation direction and an operation speed corresponding to the operation state (operation direction and operation amount) of the boom operation lever 51 (step S102). When the boom 30 is actuated to move the work table 40, the separation distance D between the work table 40 and the object K is based on detection values input from the distance measuring sensors 60 provided on the work table 40. Is detected (step S103).

Next, the restriction determination unit 73 of the controller 70 reads the distance threshold values (TD ₁ , TD ₂ ) set in the storage unit 72, the warning distance TD ₁ as the first distance threshold value, and the distance measuring sensor 6.
The separation distance D detected at 0 is compared, and the work table 40 is more than the warning distance TD ₁ by the object K.
It is determined whether or not the vehicle is approaching (step S104). Here, when the work table 40 is farther from the object K than the warning distance TD ₁ , a negative determination is made here, and when the alarm operation by the alarm device 56 has already been executed, the alarm operation is performed. After the release (step S105), the process returns to step S102, and the boom 30 continues to be operated at the operation direction and operation speed corresponding to the operation state of the boom operation lever 51. On the other hand, when the work table 40 is closer to the object K than the warning distance TD ₁ in step S104, an affirmative determination is made and an alarm operation by the alarm device 56 is executed to alert the worker. (Step S
106).

Next, the restriction determination unit 73 of the controller 70 compares the dangerous distance TD ₂ as the second distance threshold with the separation distance D detected by the distance measuring sensor 60, so that the work table 40 has the dangerous distance T
It is determined whether or not the object K is closer than D ₂ (step S107). In this step S107, when the work table 40 is farther from the object K than the danger distance TD ₂ (that is, when the work table 40 is closer than the warning distance TD ₁ and far from the danger distance TD ₂ ). Is determined negative, and the alarm operation by the alarm device 56 continues and the process returns to step S101. Incidentally, the warning operation, the work platform 40 at step S104 it is determined that remote from the object K than warning distance TD _1, thereby warning operation in step S105 is canceled, until the continued Done. On the other hand, in step S107, and in an affirmative determination is made when it is determined that the work bench 40 is approaching the subject K than risk distance TD _2, toward the restriction determination unit 73 to the valve control unit 71 regulating A signal is output, thereby restricting the operation of the boom 30 (step S108).

Next, in the restriction release unit 74 of the controller 70, the release switch 5 in the operation device 50.
It is determined whether or not 4 is turned on (step S109). Here, when the release switch 54 is not operated, the restriction release unit 74 waits for an input from the release switch 54, and until a restriction release command signal (ON signal) is input from the release switch 54, Even if the boom operation lever 51 is operated, the operation of the boom 30 is continuously restricted by the restriction determination unit 73.

When the release switch 54 is turned on by the operator, when the boom operation lever 51 is operated in the restriction release unit 74, the boom operation lever 51 is operated based on the detection information from the lever operation state detector 51a. It is determined whether or not the stage 40 has been operated in a direction to move away from the object K (step S110). Here, when the boom operation lever 51 is operated in a direction in which the work table 40 approaches the object K, this step S11.
A negative determination is made at 0, and the operation of the boom 30 continues to be regulated. On the other hand, when the boom operating lever 51 is operated in a direction to move the work table 40 away from the object K, the restriction release unit 74 releases the operation restriction of the boom 30 and moves the work table 40 in the direction. The operation of the boom 30 is allowed (step S111). As described above, when the work table 40 is closer to the object K than the danger distance TD _2, only the operation of operating the boom 30 in the direction of separating the work table 40 from the object K is permitted. By operating the boom operation lever 51 while turning on the release switch 54, the person can move the work table 40 on which he / she gets away from the object K to a safe position.

As described above, according to the safety device according to the first embodiment, the worker's safety belt 90 is moored on the work table 40 in the safety belt locking detector 19 (the worker is on the work table 40). when it) has been detected, the distance D between the worktable 40 and the object K which is detected by the distance measuring sensor 60, a warning distance as a predetermined distance threshold TD ₁ and dangerous distance TD ₂ Are compared with each other, when the separation distance D reaches the warning distance TD ₁ , the alarm device 56 is activated to alert the operator, and the separation distance D has reached the danger distance TD ₂ . In case of boom 30
Is configured to be regulated. Accordingly, when the operator is on the work table 40, the work table 40 and the worker who is on the work table 40 are prevented from coming too close to the object K in an unintended state. The operator can be prevented from being sandwiched between the work table 40 and the structure (object K), and the safety of the operator can be ensured. Therefore, it is possible to concentrate on the original work without excessive consideration of the distance to the operator, thereby reducing the burden on the operator and improving the work efficiency. In addition, in the safety device of the present embodiment, not only the operator boarded the work table 40 but also the mooring state of the worker's safety belt 90 can be detected. Both can be prevented and the safety of work can be further increased.

In the above-described embodiment, the detection value input from the distance measuring sensor 60 (the separation distance D between the work table 40 and the object K at the present time) and the distance threshold are compared and calculated.
However, the present invention is not limited to this, and a undulation angle detector, an expansion / contraction amount detector, and a turning angle detector are provided as detection means for detecting the tip position of the boom 30 (the position of the work table 40). The predicted movement trajectory of the workbench 40 is calculated based on the detected value from the device (position of the workbench 40) and the operation signal from the boom operation lever 51, and the predicted movement trajectory and the detected value from the distance measuring sensor 60 ( The working table 40 based on the separation distance between the working table 40 and the object K at the present time)
The predicted distance between the work table 40 and the object K when the robot moves is calculated, and the operation of the boom 30 is regulated based on the result of comparison between the predicted distance and the distance threshold. May be.

Next, the configuration of the safety device according to the second embodiment will be described with additional reference to FIGS. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Here, the description will focus on the parts different from the first embodiment.

As shown in FIG. 9, the safety device of the second embodiment includes an operation device 50, a work bench load detector 119, a distance measuring sensor 160, a controller 170, an alarm device 56, and a release switch 54. Yes.

The work table load detector 119 is composed of a load cell attached to the work table 40, and the load applied to the work table 40 (the weight of a tool mounted on the work table 40 in addition to the weight of the worker who is on the work table 40). ). The work table load detector 119 and the controller 170 are electrically connected, and a detection value (load load detection information) detected by the work table load detector 119 is input to the controller 170.

The distance measuring sensor 160 is connected to an object to be detected (for example, a structure installed above the work site) K using laser light, infrared light, ultrasonic waves, or the like, similar to the distance measuring sensor 60 described above. It is for detecting the distance between them in a non-contact manner, and in this embodiment, it is attached to a safety helmet 190 worn by the worker at the work site. As shown in FIG. 10, the distance measuring sensor 160 has an outer surface (an outer surface of the helmet 190) so that the detection direction faces upward when the worker wears the helmet 190 and turns the top of the head upward. The sensor head and the target detected by the distance measuring sensor 160 are attached to the front, rear, and right and left sides via brackets (not shown) (that is, four places are installed in this embodiment). The distance between the object K and the object K can be substantially regarded as a separation distance D between the operator and the object K. Note that the communication between the distance measuring sensor 160 and the controller 170 can be wired or wireless, and a detection value (separation) detected by the distance measuring sensor 160 can be used. The detection information of the distance D) is transmitted to the controller 170 by wired communication or wireless communication. Here, the wired type is advantageous in terms of responsiveness and reliability, and the wireless type is advantageous in terms of workability.

The controller 170 includes an operator boarding determination unit 75 in addition to the valve control unit 71, the storage unit 72, the restriction determination unit 73, and the restriction release unit 74. In this embodiment,
The worker boarding detection means includes a worktable load detector 119 and a worker boarding determination unit 75 of the controller 170.

The worker boarding determination unit 75 receives detection information on the load on the work table 40 detected by the work table load detector 119, and determines whether or not the load on the work table 40 exceeds a predetermined value. Based on this, it is determined whether or not an operator is on board 40. When it is determined that the loading load of the work table 40 exceeds the predetermined value, the worker boarding detection signal is output to the restriction determination unit 73 assuming that the worker is on the work table 40. Note that the predetermined value is a load value that the work table load detector 119 is supposed to indicate at least in a state where the worker is on the work table 40, and is arbitrarily set in consideration of the weight of the worker. Is done.

The storage unit 72 includes two distances D for determining whether the position of the worker on the work table 40 is too close to the object K (a risky relationship). The distance threshold, that is, the warning distance TD ₁₁ as the first distance threshold and the dangerous distance TD ₁₂ as the second distance threshold are preset and stored (provided that “danger distance TD ₁₂ <warning distance TD ₁₁ ”). Is).

When the worker boarding detection signal is input from the worker boarding judgment unit 75, the restriction judgment unit 73 receives the warning distance TD ₁₁ and the dangerous distance TD ₁₂ stored in the storage unit 72, and each distance measuring sensor 160.
Are compared with each other (refer to FIG. 11), and a worker who has boarded the work table 40 (in FIG. 11). Code “O”
It is determined whether or not there is a possibility that the object K is too close to the object K. In the restriction determination unit 73, the comparison calculation is performed in parallel for each detection value of the four distance measuring sensors 160, and the detection value (four positions) of any one of the distance measuring sensors 160 is detected. when in separation distance D indicating the minimum value among the distance measuring sensor 160) is determined to warning distance TD ₁₁ or at risk distance TD ₁₂ below, according to operating regulations and warning device 56 of the boom 30 to be illustrated below An alarm is activated.

First, as a first stage, as shown in FIG. 11B, the restriction determination unit 73 determines that the separation distance D is equal to or less than the warning distance TD ₁₁ (TD ₁₂ <D ≦ TD ₁₁ ). TD ₁₁
If the object is closer to the object K, an alarm activation signal is output to an alarm device 56 provided in the operation device 50 to give an alarm to the worker. The restriction determination unit 73 self-holds the alarm activation signal while the separation distance D is equal to or less than the warning distance TD ₁₁ , that is, until the worker is further away from the object K than the warning distance TD _11. Then, the alarm operation by the alarm device 56 is continued.

Subsequently, as a second stage, as shown in FIG. 11C, the restriction determination unit 73 determines that the separation distance D is equal to or less than the dangerous distance TD ₁₂ (D ≦ TD ₁₂ ). _{When the} object is closer to the object K than _12, a restriction signal for restricting the undulation, expansion / contraction, and turning operation of the boom 30 is output to the valve controller 71 to restrict the operation of the boom 30 (that is, the boom 30).
Forcibly stop). At this time, the valve control unit 71 that has received the restriction signal from the restriction determination unit 73 ignores the operation signal even if the boom 30 is operated (or the boom 3
By shutting off the pressure oil supply to each hydraulic actuator so that the zero operation is not performed)
The operation of the boom 30 is restricted. Further, the regulation determination unit 73 (the separation distance D is the warning distance TD ₁₁
The alarm operation signal is continuously held and the alarm operation by the alarm device 56 is continued as it is (because the following state continues).

As described above, according to the safety device according to the second embodiment, the worker detected by the ranging sensor 160 when the worker boarding determination unit 75 determines that the worker is on the work table 40. And a distance D between the object K and the warning distance TD as a preset distance threshold
And ₁₁ and dangerous distance TD ₁₂ as compared with each other, to perform a warning operation to the alarm device 56 when the distance D has reached the warning distance TD ₁₁ alert the worker, danger distance D Distance TD ₁₂
When it reaches, the operation of the boom 30 is regulated. Accordingly, when the operator is on the work table 40, the work table 40 and the worker who is on the work table 40 are prevented from coming too close to the object K in an unintended state. The operator can be prevented from being sandwiched between the work table 40 and the structure (object K), and the safety of the operator can be ensured. Therefore, it is possible to concentrate on the original work without excessive consideration of the distance to the operator, thereby reducing the burden on the operator and improving the work efficiency. Further, in the safety device of this embodiment, by attaching the distance measuring sensor 160 to the safety helmet worn by the worker, the worker's working posture (for example, standing state, middle waist state, bent state) Since the separation distance D according to the height of the worker can be detected, the safety of the worker can be further improved.

The preferred embodiments of the present invention have been described so far, but the scope of the present invention is not limited to those shown in the above-described embodiments. For example, using the distance measuring sensor 60 provided on the work table 40 and the distance measuring sensor 160 provided on the worker's helmet 190, the separation distance between the work table 40 and the object K, the operator and Both the separation distance from the object K is detected at the same time, and the operation of the boom 30 is regulated or the alarm device 56 is controlled according to the result of comparing the separation distance and the distance threshold value with each other. The structure which makes an alarm act | operate may be sufficient. According to such a configuration, the work table 40 and the distance between the worker boarding the work table 40 and the object K under different conditions such as the position of the work table 40, the posture of the worker, the state of the object K, and the like. Can be detected in accordance with the situation, and the work can be safely performed without hesitation on the unknown object K existing in the moving direction of the work table 40. it can. In addition, as described above, when the distance measuring sensor 160 is attached to the helmet 190 worn by the worker, there is an advantage that an accurate separation distance D according to the worker's working posture and height can be detected. On the other hand, depending on the worker's working posture (for example, a state in which the head is directed downward), the distance measuring sensor 160 provided on the helmet 190 may not be able to measure,
By providing the distance measuring sensors 60 and 160 on both the work table 40 and the helmet 190,
Such an unexpected situation can be avoided.

In the first embodiment described above, the distance measuring sensor 60 is provided at the four corners of the outer edge of the upper opening of the work table 40.
Is installed (that is, the four distance measuring sensors 60 are installed), but is not limited to this. For example, the distance measuring sensors 60 are installed at the four corners of the inner edge of the upper opening of the work table 40,
The distance measuring sensors 60 may be installed at a plurality of four or more locations along the outer edge of the upper opening. Here, it is preferable to remove the attachment position of the distance measuring sensor 60 from the boarding / alighting area of the work table 40 so that the operator does not get in the way when getting on and off the work table 40. Similarly, the second
In the embodiment, the outer surface of the worker's helmet 190 (top, front, rear, and left and right sides)
However, the present invention is not limited to this. For example, the distance measuring sensor 160 is installed on the top of the helmet, or the distance measuring sensor 160 is installed on the buttocks of the helmet 190. Or ranging sensors 160 may be installed at a plurality of four or more locations along the circumferential direction of the outer surface of the helmet 190. Further, the detection directions of the distance measuring sensors 60 and 160 installed at a plurality of locations are not necessarily limited to the vertically upward direction. For example, they may be directed in a plurality of directions (obliquely upward directions) with respect to the vertical axis. The distance measuring sensors 60 and 16
0 does not necessarily need to be installed at a plurality of locations, and may be installed at only one location.

Further, as a safety measure in case of malfunction of the distance measuring sensors 60, 160, a metal guard member is provided on the upper edge of the work table 40, and this guard is provided even when the work table 40 is too close to the structure. You may make it prevent an operator from contacting a structure with a member. The height of the guard member (the amount of protrusion from the upper edge of the workbench) is, for example, about 40 centimeters, but can be adjusted (extendable) according to the height of the worker. It doesn't matter.

In the above-described embodiment, the safety band locking detector 19 and the work table load detector 119 are exemplified and described as the worker boarding detection means. However, the present invention is not limited to this example. A sheet-like or mat-like pressure-sensitive switch for detecting that the vehicle is on the work table 40,
An infrared detector that detects a human (worker) in the work table 40 can also be used. A non-contact IC tag is built in a safety helmet worn by the worker, and this I
By attaching an IC tag reader (reader) that can read stored information of the C tag, it is not only possible to detect whether or not the operator is on the work table 40, but this worker wears a helmet. It may be configured so that whether or not it can be detected together.

Further, when the separation distance D between the work table 40 and the object K is equal to or less than the warning distances TD ₁ and TD ₁₁ , the above embodiment is exemplified on the condition that the foot switch 53 is depressed. You may comprise so that the alarm action | operation by the alarm device 56 may be performed. When the separation distance D is equal to or less than the warning distances TD ₁ , TD ₁₁ , as described above, if the alarm operation by the alarm device 56 is always continued, the significance of the danger notification to the operator is lessened, and the neighborhood buzzer sounds due to the alarm buzzer sound. Therefore, when the foot switch 53 is not depressed (in the state where the foot switch 53 is turned off), the alarm operation is stopped to ensure the operator's attention and Noise prevention can be aimed at. At this time, when the foot switch 53 is depressed, an alarm is activated even if the boom operation lever 51 is not operated. Therefore, the safety awareness of the worker who will perform the operation of the boom 30 is increased. , Can ensure thorough safety operation.

In the above-described embodiment, the boom 30 is operated by operating the boom operation lever 51.
Is operated to freely move up and down, extend and retract, but the operation device 50 has a mode selection switch for selecting and operating either the normal mode or the horizontal / vertical operation control mode (referred to as “HV mode”). It may be provided to operate the boom 30 according to one of two operation control modes. The normal mode is a mode in which the hydraulic actuators can be operated individually or simultaneously by operating the boom operation lever 51. The HV mode is a mode in which the hydraulic actuators are operated in conjunction with each other by operating the boom operation lever 51. Boom 30
This is a mode in which the front end portion (including the work table 40) can be moved linearly in the horizontal direction or the vertical direction. Here, when the mode selection switch is selected to the HV mode side, the operator operates the operation lever 51 to linearly move the work table 40 (the tip of the boom 30) vertically upward, The work table 40 can be made to approach the target object K (upper structure) more efficiently than in the normal mode, but on the other hand, the work table 40 approaches the object K in a short time. There is a risk of overdoing it. Even in such a case, according to the safety device of the above-described embodiment, even when the boom 30 is operated according to the HV mode, the work table 40 is prevented from being too close to the object K in an unintended state. Therefore, it is effective because it is possible to prevent the operator from being caught between the work table 40 and the upper structure (object K) during work at high places, and to ensure the safety of the operator. .

In the above-described embodiment, the object to which the present invention is applied is a work vehicle whose body is a tire wheel type, but the vehicle body is not necessarily limited to a tire wheel type, and travels by a crawler device or the like. It may be a thing. Alternatively, it may be an orbital working vehicle that includes an orbital traveling wheel and travels on an orbital track, and further, an orbital working vehicle that includes both a tire wheel and an orbital traveling wheel.

In the above-described embodiment, the lifting device attached to the vehicle body of an aerial work vehicle has been described as an example of an extendable boom that can be raised, lowered, extended, and turned. Further, the lifting device is not limited to the one that can move the work table three-dimensionally, such as the boom, but can be a device that can only lift and lower the work table vertically, such as a scissor-link lifting device. There may be.

DESCRIPTION OF SYMBOLS 1 High-altitude work vehicle 10 Vehicle body 17 Hook locking bracket (safety belt locking means, worker boarding detection means)
19 Safety belt locking detector (safety belt locking detection means, worker boarding detection means)
30 Boom (lifting device)
40 work table 50 operation device (operation means)
51 Boom operation lever (operation means)
56 Alarm device (alarm means)
60 Ranging sensor (distance detection means)
71 Valve control unit (operation control means)
72 Storage Unit 73 Restriction Judgment Unit (Regulation Judgment Unit)
74 Restriction release unit 75 Worker boarding determination unit (worker boarding detection means)
90 Safety belt 119 Platform load detector (worker boarding detection means)
160 Distance sensor (distance detection means)
190 Helmet K Object D Separation distance OP Worker TD Distance threshold (TD ₁ , TD ₁₁ : First distance threshold, TD ₂ , TD ₁₂ : Second distance threshold)

Claims (4)

A vehicle body that can travel,
A lifting device attached to the vehicle body so as to be movable up and down;
A worktable attached to the lifting device and on which an operator can board;
Operating means for operating the lifting device;
An operation control means for controlling the operation of the lifting device based on an operation signal from the operation means;
Worker boarding detection means for detecting whether a worker is on board the work table;
Distance detecting means for detecting a separation distance to the object above the workbench;
Alarm means for performing a predetermined alarm operation;
When it is detected by the worker boarding detection means that an operator is on the work table, the separation distance detected by the distance detection means is compared with a preset distance threshold, and the separation When the distance is less than or equal to the first distance threshold, the alarm means is activated, and when the separation distance is less than or equal to the second distance threshold that is smaller than the first distance threshold, the work table A safety device for an aerial work vehicle, comprising: a restriction determination means for restricting the operation of the lifting device in a direction in which the vehicle is moved closer to the object. The worker boarding detection means includes a safety belt attached to the worker himself boarded on the worktable,
The safety belt locking detection means for detecting whether or not the safety belt is locked by a safety belt locking means provided on the work table. Safety equipment for work vehicles. The distance detecting means is provided in a helmet worn by an operator,
The safety device for an aerial work vehicle according to claim 1 or 2, wherein the distance detection means detects a separation distance to an object above the worker who is on the work table. When an operator gets on the work table, the distance detection means provided on the work table;
3. The aerial work vehicle according to claim 1, wherein a separation distance to an object above the workbench is respectively detected by the distance detection unit provided in a helmet worn by an operator. Safety device.

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