JP6656976B2 - Aerial work vehicle - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an aerial work vehicle provided with a work table that is moved up and down by an elevating device provided on a vehicle body.

  2. Description of the Related Art As an example of an aerial work vehicle, an aerial work vehicle that is configured based on a truck vehicle that can travel and has a working device mounted on its body is known. The work device includes a swivel table horizontally rotatable on a vehicle body, an extendable and retractable boom pivotally connected to the swivel table, and a vertically pivotable pivot at a tip end of the boom. Some are configured to include a vertical post that is tied and held vertically irrespective of the boom undulation angle, and a work table that is mounted on the vertical post in a horizontal state. There is also a configuration in which a vertical mast or scissors link mechanism that can expand and contract in the vertical direction is provided instead of the swivel table and the boom, and the work table attached to the upper part thereof is vertically moved up and down.

  Such aerial work vehicles are used in various work sites such as electric wire work, maintenance and inspection work in road tunnels, and maintenance and inspection work for bridges. For example, when performing an operation on an upper structure such as a ceiling in a road tunnel or a lower surface of a bridge, the work table is moved up and down to approach the upper structure. At this time, if the workbench is too close to the upper structure, there is a risk that the operator will be caught between the worktable and the upper structure. Therefore, a distance sensor is provided to detect the distance between the workbench and the upper structure by irradiating light upward from the workbench and detecting the light reflected by the upper structure. There is known an aerial work vehicle configured to restrict the movement of the workbench in a direction approaching an upper structure when the operation is detected and warn with a buzzer or the like (for example, Patent Document 1). See).

JP 2013-52948 A

  By the way, as described above, in the configuration in which the distance between the work table and the upper structure is detected by irradiating light upward from the work table and detecting light reflected by the upper structure, for example, the lower surface of a bridge or the like is used. When there are many irregularities as in the above, the distance between the platform and the upper structure cannot be detected properly, so that the platform may be too close to the upper structure, and in some cases, the platform and the upper structure There was a problem that contact with.

  The present invention has been made in view of such a problem, and even when the upper structure has many irregularities, the distance between the work table and the upper structure can be appropriately detected, and the work table It is an object of the present invention to provide an aerial work vehicle capable of preventing a vehicle from approaching an upper structure too much.

In order to solve the above-mentioned problem, an aerial work vehicle according to the present invention includes a movable vehicle body and an elevating device (for example, a swivel base 4, a boom 5, a bending post 6 and a post 10 in the embodiment) provided on the vehicle body. ), A work table attached to the lifting device and moved up and down, operation means provided on the work table for performing an operation operation of the lifting device, and the operation means based on an operation signal from the operation means. Operation control means for controlling the operation of the lifting device; and work platform approach detection means for detecting that the work platform has approached the lower end of a structure located above the work platform (for example, Work platform approach detection device 30), alarm means (for example, controller 70 and alarm device 80 in the embodiment) for performing an alarm operation based on the detection of the work platform approach detection means, Provided. The workbench approach detection means is provided at one end of the workbench, in a direction substantially parallel to the floor surface at a predetermined height position above the workbench height from the workbench floor surface. And a light receiving means provided at the other end of the worktable and capable of receiving the light emitted from the light projecting means . Then, when the light is emitted from the light projecting unit, when the amount of the light received by the light receiving unit is equal to or less than a predetermined level, the work table approaches the lower end of the structure. Detect that .

  In the aerial work vehicle having the above configuration, the worktable is configured to be capable of expanding and reducing the floor surface in a predetermined direction, and the light projecting unit is provided at one end of the worktable in the enlargement / reduction direction. Preferably, the light receiving means is provided on the other end side in the enlargement / reduction direction.

  In the aerial work vehicle having the above-described configuration, the light projecting unit is configured to be able to adjust a height position of the light to be irradiated from the floor surface, and the light receiving unit is configured to receive the light at the floor surface. It is preferable to be able to adjust the height position from above.

  In the aerial work vehicle having the above structure, the operation means has an operation lever operated by a worker's hand and a foot switch operated by a foot, and is operated only when the foot switch is turned on. It is configured to transmit an operation signal from the operation lever to the operation control unit, and the light emitting unit is controlled to emit the light only when the foot switch is turned on. preferable.

  In the aerial work vehicle configured as described above, it is preferable that the light projecting means is controlled so as to emit the light when a traveling work state of the vehicle is detected.

  According to the aerial work vehicle according to the present invention, light in a direction substantially parallel to the floor surface at a predetermined height from the floor surface of the work table is emitted from the light projecting means provided at one end of the work table. And the light receiving means provided at the other end of the worktable is configured to receive the light, and when the light is irradiated from the light projecting means, the light receiving means receives the light. An alarm is activated when the amount falls below a predetermined level. Therefore, even when the upper structure has many irregularities, the convex portion (the lowermost end) of the upper structure enters between the light projecting means and the light receiving means to block light from the light projecting means. Since the amount of light received by the light receiving means is reduced, it is possible to detect that the upper structure has approached the height position of the light emitted from the light emitting means. By performing the alarm operation at this time, it is possible to prevent the work table from approaching too close to the upper structure. In the present specification, the alarm operation includes an operation that regulates an operation of the elevating device (an operation that moves the workbench in a direction to approach the upper structure) and an operation that includes an operation of issuing an alarm using a buzzer, a lamp, or the like. Means

  In addition, the worktable is configured to be able to expand and contract the area of the floor in a predetermined direction, the light projecting means is provided at one end of the worktable in the enlargement / reduction direction, and the light receiving means is located at the other end in the enlargement / reduction direction. In this configuration, the light projecting means and the light receiving means can detect that the upper structure has approached, regardless of whether the work table is enlarged or reduced.

  Further, if the height of the work table irradiated from the light projecting means from the floor surface can be adjusted, the work table and the upper structure can be adjusted by adjusting the light irradiation position (height position). Can change the accessible distance.

Further, if the light emitting means is controlled so as to emit light only when the foot switch of the operating device is turned on, the light emitting means is only emitted when the workbench is moved up and down by the elevating device. It is possible to detect the approach of the upper structure by the means and the light receiving means. In addition, since the light is not emitted from the light emitting means when the workbench is not moved up and down, it is possible to prevent a situation in which a worker during the inspection work is erroneously detected and an alarm is activated (alarm by a buzzer or a lamp). Can be.

  Further, if the light emitting means is configured to emit light when the traveling work state of the vehicle is detected, the foot switch is turned on when performing the inspection work while the vehicle is traveling. Even when it is not, the approach of the work table and the upper structure can be detected by the light emitting means and the light receiving means. Then, by performing an alarm operation (alarm by a buzzer, a lamp, or the like), it is possible to notify a worker who is performing an inspection work or a driver of the vehicle of the approach of the work table and the upper structure. In the present specification, the running state of the vehicle refers to a state in which the side brake of the vehicle is turned off to release the braking of the wheels, or a power for extracting the power of the engine mounted on the vehicle for driving the lifting device. This includes a state in which the work can be performed while the vehicle is running, including a state in which the take-off mechanism is turned off and the driving of the elevating device is stopped.

It is a side view of the bridge inspection vehicle which is an example of the aerial work vehicle according to the present invention. It is a block diagram which shows the control system of the said bridge inspection vehicle. It is a rear view (partial sectional drawing) which shows the inspection work state of the said bridge inspection vehicle. It is a top view which shows the structure of the work bench of the said bridge inspection vehicle. It is a rear view (partial sectional view) showing the state where the above-mentioned workbench and the upper structure approached. It is a rear view (partial sectional view) which shows the said work bench and another state which approached the upper structure.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a bridge inspection vehicle which is an example of the aerial work vehicle according to the present invention will be described. As shown in FIG. 1, the bridge inspection vehicle 1 is configured based on a truck vehicle, and can run by arranging wheels 3 a and 3 b at both front and rear left and right ends of a vehicle body 2. An operation cab 2a is provided.

  Roller jacks 17 are provided on the front, rear, left and right sides of the vehicle body 2. The roller jack 17 has an outrigger 17a (see FIG. 3) that can be widened in the left-right direction of the vehicle body, a jack 17b that can be expanded and contracted in the vertical direction, and a roller 17c that is rotatably attached to the lower end of the jack 17b. It is composed. In the bridge inspection vehicle 1, the outrigger 17 a is extended and the roller 17 c is brought into contact with the road surface, so that the vehicle can travel while the work table 20 described below is moved to a desired position to perform work. I have. The operation of operating the roller jack 17 is performed by operating a jack operation lever (not shown) provided on the vehicle body 2.

  A swivel 4 is attached to a rear part of the vehicle body 2 so as to be freely rotatable horizontally. The swivel 4 is configured to be able to swing by a swing motor 51 built in the body 2. A boom 5 whose base is pivotably connected to the upper part of the revolving base 4 so as to be able to swing up and down is attached. The boom 5 is configured to be able to move up and down by a boom raising and lowering cylinder 52 laid between the swivel 4 and the boom 5. Further, the boom 5 is telescopically combined with a base boom 5a and a distal end boom 5b in a nested manner from the base end side, and is configured to be able to expand and contract by a built-in boom telescopic cylinder 53.

A bending post 6 is pivotally connected to the distal end of the tip boom 5b so as to be vertically swingable. A link arm 7 is pivotally connected to the pivot axis of the bending post 6 coaxially. The rod-side end of the post-leveling cylinder 54 is pivotally connected to the upper end of the link arm 7, and the bottom-side end of this cylinder 54 is pivotally connected to the tip boom 5b. The lower end of the link arm 7 is pivotally connected to a rod-side end of a post up / down cylinder 55, and the bottom end of the cylinder 55 is pivotally connected to a lower portion of the bending / extending post 6. A post 10 is attached to the tip of the bending / extending post 6.

  The bending / extending post 6 is configured to be able to swing up and down with respect to the tip boom 5b by a post hoist cylinder 55, so that the post 10 can be set at a desired bending / extension angle position. The bottom-side oil chamber of the post-leveling cylinder 54 and the rod-side oil chamber of the boom raising / lowering cylinder 52 are connected by an oil path to form a so-called hydraulic circuit-type leveling mechanism, and the boom 5 is raised and lowered. In this case, the bending / stretching post 6 is moved up and down by the same angle as the up / down angle of the boom 5 via the link arm 7 and the post up / down cylinder 55, so that the post 10 is always constant regardless of the up / down angle of the boom 5. It is configured to be held at an angle (the post 10 is always kept vertical during normal operation).

  The post 10 includes a holder 10h fixed to the bending / stretching post 6, and a first post 10a, a second post 10b, a third post 10c, and a fourth post 10d nested in the holder 10h. Be composed. The post 10 is first to first-positioned with respect to the holder 10h by a post elevating cylinder 56 provided between the holder 10h and the first post 10a and a post telescopic cylinder (not shown) provided inside the post. The four posts 10a to 10d are configured to be able to expand and contract. An arm 11 is pivotally connected to a tip end of the fourth post 10d about an axis extending in the front-rear direction in the state shown in FIG. 1, and the arm 11 can be pivoted by an arm pivot cylinder (not shown). Is configured. The turning operation of the arm 11 is allowed only when the post 10 is in a horizontal state, and is specifically used when working at a high place or when the work table 20 is stored on the vehicle body 2.

  A turning base 12 is pivotally connected to the tip of the arm 11 so as to be vertically swingable. A worktable leveling cylinder 57 is provided between the arm 11 and the turning base 12. The work base bracket 13 is attached to the swivel base 12 so as to be swivelable about an axis extending vertically in the state shown in FIG. 1, and the work table bracket 13 is moved with respect to the swivel base 12 by a built-in work table swivel motor 59. It is configured to be able to pivot (swing). A work table 20 is attached to a lower end of the work table bracket 13. The worktable leveling cylinder 57 is controlled to expand and contract based on a detection signal of an inclination detector provided on the worktable 20, and regardless of the up-and-down angle of the boom 5 and the bending and extension angle of the post 10, The leveling control is performed so that the floor surface is always kept horizontal (the work table bracket 13 is always vertically extended).

  The worktable 20 is configured such that a base deck 21a, an intermediate deck 21b, and a distal deck 21c are assembled in a nesting manner from the workbench bracket 13 side, and can expand and contract in a direction orthogonal to the rotation axis of the workbench bracket 13. The deck deck expansion / contraction cylinder 58 moves the intermediate deck 21b and the distal deck 21c relative to the base deck 21a so that the floor area of the work table 20 can be enlarged and reduced.

  As shown in FIGS. 3 and 4, the base deck 21a, the intermediate deck 21b, and the distal deck 21c are rectangular work floors 22a, 22b, and 22c on which a worker can ride, and upper surfaces of these work floors. It has handrails 23a, 23b, and 23c standing upright so as to surround the periphery. In the present embodiment, the three-stage work table 20 including the base deck 21a, the intermediate deck 21b, and the front deck 21c is exemplified. However, for example, the work floor area is constant (a configuration in which the work floor area is not enlarged or reduced). A configuration having a workbench or a workbench of two-stage type or four-stage type or more may be employed.

  The work table 20 is provided with an operation device 40 operated by a worker on board. As shown in FIG. 2, the operation device 40 includes a boom operation lever 41 for performing up / down, extension / retraction, and turning operations of the boom 5, and a post operation lever 42 for performing up / down (flexion / extension) and extension / contraction operations of the post 10. , A worktable operation lever 43 for performing the turning (swinging) and the enlargement / reduction operation of the worktable 20. The operator operates these operating levers 41 to 43 by hand, and thereby, the boom hoist cylinder 52, the boom telescopic cylinder 53, the turning motor 51, the post hoist cylinder 55, the post elevating cylinder 56, the workbench turning motor 59, and the work table turning motor 59 Each operation of the table expansion / contraction cylinder 58 can be performed.

  The vehicle body 2 is provided with a traveling engine E, a hydraulic pump P, and a power take-off mechanism PTO that extracts the driving force of the engine E and drives the hydraulic pump P. A PTO operation lever 15 for turning on / off the power take-off mechanism PTO (driving or stopping the hydraulic pump P) is provided in the driving cab 2a. Hydraulic oil discharged from the hydraulic pump P is supplied to the swing motor 51, the up-and-down cylinder 52, the boom telescopic cylinder 53, the post up-and-down cylinder 55, the post elevating cylinder 56, the workbench expanding / contracting cylinder 58, and the workbench swing motor 59. It is supplied via control valves V1 to V7 corresponding to the hydraulic actuator. Each of these hydraulic actuators operates in a direction and at a speed according to the driving state of the spool of the corresponding control valve.

Further, a controller 70 is provided in the vehicle body 2, and the valve control unit 71 of the controller 70 controls the control valve based on an operation signal output according to the operation state (operation direction and operation amount) of the boom operation lever 41. The respective spools V1 to V3 are driven, and the respective spools of the control valves V4 and V5 are driven based on an operation signal output in accordance with the operation state of the post operation lever 42, and the operation of the worktable operation lever 43 is performed. The respective spools of the control valves V6 and V7 are driven based on the operation signals output from the control valves V6 and V7 . The operation states (operation directions and operation amounts) of the boom operation lever 41, the post operation lever 42, and the worktable operation lever 43 are detected by lever operation state detectors 41a, 42a, 43a (for example, constituted by potentiometers). The detection signal is input to the valve control unit 71 as an operation signal corresponding to the operation direction and the operation amount of the operation levers 41 to 43.

  The operation device 40 is provided on the floor surface of the work table 20 and includes a pedal-type foot switch 45 that is operated by an operator who steps on the work table 20 with his or her foot. The foot switch 45 is a switch that permits the operation of each hydraulic actuator by the operation of the boom operation lever 41, the post operation lever 42, and the workbench operation lever 43 only when the operator is stepping on the foot to turn on the foot. The switch operation signal is output in the on-operation state where the driver is depressed, and is not output in the off-operation state (non-operation state) where the depression is released. The switch operation signal output from the foot switch 45 is input to the valve control unit 71 of the controller 70, and the valve control unit 71 transmits the switch operation signal from the foot switch 45 only when the switch operation signal is input from the foot switch 45. Each of the operation signals output by operating the operation lever 42 and the platform operation lever 43 is treated as valid, and the spool of each control valve is driven based on each operation signal to operate each hydraulic actuator. It is configured.

  The bridge inspection vehicle 1 configured as described above includes a safety device for preventing an accident in which an operator is pinched between the work table 20 and the upper structure during the inspection work. This safety device will be described below. The safety device includes a workbench approach detection device 30 that detects that the workbench 20 has approached an upper structure, a controller 70, and an alarm device 80 provided in each of the workbench 20 and the driving cab 2a. It is composed. The alarm device 80 has an alarm buzzer 81, an alarm lamp 82, and an alarm display 83, and is configured to notify a worker of danger visually or audibly.

  As shown in FIGS. 3 and 4, the workbench approach detection device 30 includes a light emitter 31 provided at a distal end of a front deck 21 c of the worktable 20 and a light receiver provided at a base end of the base deck 21 a. 32. The floodlight 31 is fixed to the distal end of a rod-shaped holding member 33 that is configured to be extendable and contracted, is disposed at a predetermined height from the work floor 22c of the front deck 21c, and is disposed in a direction substantially parallel to the work floor 22c (working direction). The light L is emitted toward the base deck 21a side in the direction of expansion and contraction of the table 20). The light projector 31 can adjust the height position of the light projector 31, that is, the height position of the light L to be irradiated, by expanding and contracting the holding member 33. The light receiver 32 is fixed to a distal end portion of a rod-shaped holding member 34 which is configured to be extendable and contractible similarly to the holding member 33, and has a height position (and a front, rear, left, right, and right) at which light L emitted from the light projector 31 can be received. Position). The height position of the light receiver 32 can also be adjusted by expanding and contracting the holding member 34. The holding members 33 and 34 are provided with springs therein, and when the force is released from the contracted state, the springs restore the original length.

  As shown in FIG. 4, the projector 31 is disposed at an end of the front deck 21c (the work floor 22c) in a direction orthogonal to the enlargement / reduction direction of the worktable 20 in a plan view. The light receiver 32 is disposed at an end of the base deck 21a (the work floor 22a) in the orthogonal direction. Therefore, the light L emitted from the light projector 31 reaches the light receiver 32 through above the handrails 23c, 23b, 23a, and the worker moving on the work floors 22a to 22c receives the light L. The light projector 31 and the light receiver 32 are arranged so as not to block L. The light projector 31 and the light receiver 32 are arranged at both ends of the work table 20 in the orthogonal direction, respectively. The work table approach detection device 30 includes two sets of the light projector 31 and the light receiver 32. I have.

  As shown in FIG. 2, the light projector 31 and the light receiver 32 are electrically connected to a controller 70. When the light L emitted from the light projector 31 is detected in the light receiver 32, a detection signal (light amount information value) ) Is input to the controller 70. Further, the controller 70 is electrically connected to the PTO operation lever 15 and the side brake lever 16 (parking brake lever) in the driving cab 2a, and the foot switch 45 of the operation device 40. The controller 70 is configured to perform control to irradiate the light L from the light projector 31 only when the foot switch 45 is depressed and turned on and a switch operation signal is input from the foot switch 45. Further, even when the foot switch 45 is not turned on, the controller 70 turns off the PTO operation lever 15 to stop the hydraulic pump P, and also turns off the side brake lever 16 to operate the parking brake. As a result, when the braking of the wheels 3a and 3b of the vehicle body 2 is released and a signal indicating a state in which the work can be performed while the vehicle is running is input, the light L is controlled to be emitted from the projector 31. It is configured.

  The controller 70 includes an alarm determining unit 72 and an alarm canceling unit 73 in addition to the valve control unit 71 described above. Based on the detection signal (light amount information value) input from the light receiver 32, the alarm determination unit 72 determines that the workbench 20 has approached the upper structure K within a predetermined alarm distance or less, as described later. It is determined whether it is in the state. Then, when it is determined that the work table 20 is in the state of approaching the upper structure K, the alarm determination unit 72 controls the operation of the boom 5, the bending / extending post 6, and the post 10, and the alarm operation by the alarm device 80. Configured to run.

As shown in FIG. 3, when the work table 20 is separated from the upper structure K by more than a predetermined warning distance D, the light L emitted from the projector 31 may be blocked by the upper structure K. Therefore, the light L is received by the light receiver 32. Therefore, when the light L is emitted from the light emitter 31, the alarm determination unit 72 detects that the light receiver 32 receives the light L of the light amount of a predetermined level or more based on the detection signal input from the light receiver 32. When the presence state is detected, the workbench 20 is configured to be determined to be farther than the warning distance D from the upper structure K. At this time, the alarm determination unit 72 does not execute the operation restriction of the boom 5 or the like and the alarm operation by the alarm device 80. The warning distance D is a distance corresponding to a height position of the light L emitted from the light projector 31 from the work floors 22c and 22a, and the worker is sandwiched between the work table 20 and the upper structure K. It is set to secure a safe space to the extent that it is not. The alarm distance D can be adjusted by expanding and contracting the holding members 33 and 34 and adjusting the height positions of the light projector 31 and the light receiver 32 as described above.

  As shown in FIG. 5, when the work table 20 approaches the upper structure K below the alarm distance D or less, the light L emitted from the floodlight 31 emits a convex portion such as a steel frame on the lower surface of the upper structure K. Therefore, the light L does not reach the light receiver 32 or the amount of the light L reaching the light receiver 32 decreases to a predetermined level or less. In addition, as shown in FIG. 6, when the work table 20 approaches the upper structure K below the alarm distance D and the convex portion on the lower surface of the upper structure K contacts the upper surface of the projector 31. Since the holding member 33 holding the light projector 31 is reduced and the height of the light projector 31 is lowered, the light L emitted from the light projector 31 does not reach the light receiver 32.

  Therefore, when the light L is emitted from the light projector 31, the alarm determination unit 72 reduces the light amount of the light L received by the light receiver 32 to a predetermined level or more based on the detection signal input from the light receiver 32. When such a state is detected, it is determined that the work table 20 is closer to the upper structure K than a predetermined alarm distance D or less. The alarm determination unit 72 regulates the operation in the direction in which the workbench 20 is brought closer to the upper structure K, out of the operation of the boom 5 falling and expanding and contracting, the operation of the bending and stretching post 6 being raised and lowered (bending and stretching), and the operation of the post 10 expanding and contracting. The control signal is output to the valve control unit 71 to restrict the operation (forced stop). At this time, by operating the boom operation lever 41 and the post operation lever 42, the valve control unit 71 operates the boom 5, the bending / extending post 6, and the post 10 in the direction in which the work table 20 approaches the upper structure K. Also, the operation signal is ignored (or the supply of hydraulic oil to each hydraulic actuator is stopped so that the operation of the boom 5, the bending post 6 and the post 10 is not performed), and the boom 5, the bending and extending post It is configured to regulate the operation of the post 6 and the post 10.

  When determining that the work platform 20 is close to the upper structure K within the warning distance D or less as described above, the warning determination unit 72 is provided in the work platform 20 and the driving cab 2a, respectively. An alarm activation signal is output to the alarm device 80, and the alarm buzzer 81, the alarm lamp 82, and the alarm display 83 of the alarm device 80 notify the worker that the work platform 20 is approaching the upper structure K. . Note that the alarm determination unit 72 determines that the workbench 20 is closer to the upper structure K than the warning distance D, that is, the worktable 20 is separated from the upper structure K by more than the warning distance D. The alarm operation signal is held by itself, and the alarm operation by the alarm device 80 is continued.

The alarm canceling unit 73 is electrically connected to the alarm canceling switch 46 provided in the operation device 40, and receives an alarm canceling signal only when the alarm canceling switch 46 is turned on. I have. The alarm release switch 46 is configured by a momentary switch, and is configured to automatically return to the neutral position and be turned off when the operation is released. The alarm canceling unit 73 controls the operation of the boom 5, the bending / stretching post 6, and the post 10 in the direction in which the workbench 20 approaches the upper structure K by the alarm determining unit 72, and the alarm operation by the alarm device 80. When the alarm release signal is received from the alarm release switch 46, a release signal for releasing the operation restriction of the boom 5, the bending / extending post 6, and the post 10 is output to the valve control unit 71, and the work table 20 is brought closer to the upper structure K. The directional boom 5, the bending post 6 and the post 10 are configured to allow operation. At this time, the valve control unit 71 operates the boom 5, the bending / extending post 6, and the post 10 at a lower speed than usual. In addition, the alarm determination unit 72 changes the alarm sound or the alarm display of the alarm operation by the alarm device 80 to warn that the upper structure K is approaching.

  According to the safety device for the worktable 20 configured as described above, the floor 31 is provided at a predetermined height from the floor surface (work floor) of the worktable from the projector 31 provided at one end of the worktable 20. Light L is emitted in a direction substantially parallel to the surface, and the light L is received by a light receiver 32 provided at the other end of the worktable. When the light L is received from the light projector 31 and the light amount of the light L received by the light receiver 32 falls below a predetermined level, the boom 5 and the bending / extending post 6 in the direction in which the work table 20 approaches the upper structure K. In addition, the operation of the post 10 and the alarm operation by the alarm device 80 are performed. Therefore, even if the lower surface of the upper structure K has many irregularities, the convex portion (the lowermost end) of the upper structure K enters between the light projector 31 and the light receiver 32 and emits the light L from the light projector 31. By blocking, the amount of light received by the light receiver 32 is reduced, so that it is possible to detect that the upper structure K has approached the height position of the light L emitted from the light projector 31. Then, at this time, by restricting the operation of the boom 5, the bending / extending post 6, and the post 10, and performing an alarm operation by the alarm device 80, it is possible to prevent the work table 20 from being too close to the upper structure K.

  Further, the worktable 20 is configured to be able to expand and contract the area of the floor surface in a predetermined direction, a projector 31 is provided on one end of the worktable 20 in the enlargement / reduction direction, and the light receiver 32 is located in the other direction in the enlargement / reduction direction. It is provided on the end side. Therefore, the projector 31 and the light receiver 32 can detect that the upper structure K has approached, regardless of whether the work table 20 is enlarged or reduced.

  The light projector 31 is configured so that the height position of the irradiation light L from the floor surface of the worktable 20 can be adjusted by expanding and contracting the holding member 33. Therefore, by adjusting the height position of the light projector 31 and the light receiver 32, that is, the height position of the light L emitted from the light projector 31, by expanding and contracting the holding members 33 and 34, the work table 20 and the upper structure K can be connected to each other. The approachable distance (warning distance D) can be changed. When the upper structure K comes into contact with the upper surface of the light projector 31 or the light receiver 32, the holding members 33 and 34 are reduced and the height position of the light projector 31 or the light receiver 32 is changed. The received light L cannot be received by the light receiver 32, so that it can be detected that the upper structure K has approached. In addition, since the holding members 33 and 34 are reduced when the upper structure K comes into contact, it is possible to prevent the light projector 31 or the light receiver 32 from being crushed and damaged. When the contact with the upper structure K is released, the holding members 33 and 34 are restored to their original lengths by the springs provided inside the holding members 33 and 34. 32 can be restored to the original height position.

  Further, the light projector 31 is configured to perform control to irradiate the light L from the light projector 31 only when the foot switch 45 of the operation device 40 is turned on. Therefore, only when the work table 20 is moved up and down by the operation of the operation device 40, it is possible to detect the approach of the upper structure K by the light emitter 31 and the light receiver 32. Further, since the light L is not emitted from the light emitter 31 when the work table 20 is not moved up and down, it is possible to prevent a situation in which a worker during the inspection work is erroneously detected and an alarm operation (alarm by a buzzer or a lamp) is performed. be able to.

In addition, the PTO operation lever 15 is turned off to stop the hydraulic pump P, and the side brake lever 16 is turned off to release the braking of the wheels 3a and 3b of the vehicle body 2 by the parking brake. When a state in which work can be performed is detected, control to irradiate the light L from the light projector 31 is performed. Therefore, when performing the inspection work while running the vehicle, even when the foot switch 45 is not turned on, it is necessary to detect the approach between the work table 20 and the upper structure K by the light emitter 31 and the light receiver 32. Can be. Then, by performing an alarm operation (alarm by a buzzer, a lamp, or the like) by the alarm device 80, it is possible to notify a worker under inspection or a driver of the vehicle of the approach of the work table 20 and the upper structure K. .

  Although the embodiment according to the present invention has been described, the scope of the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the light emitter 31 and the light receiver 32 are fixed to the distal ends of the holding members 33 and 34, and the holding members 33 and 34 are expanded and contracted, so that the height position of the light L emitted from the light emitter 31 is increased. Can be adjusted, for example, by arranging a plurality of light emitters 31 and light receivers 32 in the height direction and switching among the plurality of light emitters 31 for irradiating the light L, the light L can be adjusted. Height position (warning distance D) may be adjusted.

  In the above-described embodiment, two sets of the light emitters 31 and the light receivers 32 are provided on both sides of the work table 20. However, one or three or more sets of the light emitters 31 and the light receivers 32 are provided. May be. In the above-described embodiment, an example in which the present invention is applied to a bridge inspection vehicle has been described. However, the present invention is directed to a high-rise system in which a workbench is vertically moved by a vertical mast provided on a vehicle body and capable of vertically expanding and contracting. The present invention can be applied to a variety of aerial work vehicles such as an aerial work vehicle and an aerial work vehicle in which a work table is moved up and down by a scissors link mechanism provided on a vehicle body.

1 Bridge inspection vehicle (aerial work vehicle)
2 Body 4 Turning table (elevating device)
5 Boom (elevating device)
6 Bending and stretching post (elevating device)
10 post (elevator)
20 work table 31 floodlight (lighting means)
32 light receiver (light receiving means)
40 Operating device 45 Foot switch 70 Controller 71 Valve control unit (alarm means)
72 alarm judgment part (alarm means)
80 Alarm device (alarm means)

Claims (5)

A car body that can run,
An elevating device provided on the vehicle body,
A work table that is attached to the lifting device and moved up and down,
Operating means provided on the work table, for operating the lifting device,
An aerial work vehicle comprising: an operation control unit that controls an operation of the elevating device based on an operation signal from the operation unit.
Work platform approach detection means for detecting that the work platform has approached the lower end of the structure located above the work platform,
Alarm means for performing an alarm operation based on the detection of the work platform approach detection means,
The workbench approach detection means is provided at one end of the workbench, in a direction substantially parallel to the floor surface at a predetermined height position above the workbench height from the workbench floor surface. Light emitting means for irradiating light of
Light receiving means provided at the other end of the worktable and capable of receiving the light emitted from the light projecting means ,
When the light is emitted from the light projecting means, when the amount of the light received by the light receiving means is equal to or less than a predetermined level, the work table approaches the lower end of the structure. An aerial work vehicle characterized by detecting . The work table is configured to be able to expand and contract the area of the floor surface in a predetermined direction,
2. The work at height according to claim 1, wherein the light projecting means is provided at one end of the worktable in the enlargement / reduction direction, and the light receiving means is provided at the other end of the work table in the enlargement / reduction direction. car. The light projecting means is configured to be able to adjust a height position of the light to be irradiated from the floor surface,
The aerial work vehicle according to claim 1, wherein the light receiving unit is configured to adjust a height position of a portion that receives the light from the floor surface. The operation means has an operation lever operated by a worker's hand and a foot switch operated by a foot, and outputs an operation signal from the operation lever only when the foot switch is turned on. Configured to transmit to the operation control means,
The aerial work vehicle according to any one of claims 1 to 3, wherein the light emitting unit is controlled to emit the light only when the foot switch is turned on. .   The aerial work vehicle according to any one of claims 1 to 4, wherein the light projecting unit is controlled to emit the light when a traveling work state of the vehicle is detected.

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