Pinch prevention device

Abstract

To provide a nip preventing device that can improve the safety and workability of high lift work.SOLUTION: A nip preventing device (a controller 60, a foot switch 44) mounted on a work floor 40 of a high lift work vehicle 1 comprises: a detection unit (an ultrasonic sensor 62) for non-contact detection of an object A above the work floor 40; a control unit 67 capable of stopping the lifting of the work floor 40 (step S13:YES, step S14) when the detection unit (the ultrasonic sensor 62) detects the object A; and a release device (an enable switch 64, a foot switch 44) capable of releasing (step S16:YES, step S17:YES, step S18:YES, step S19) the stop of the lifting of the work floor 40 by the control unit 67 when a prescribed release operation is performed while the control unit 67 has stopped the lifting of the work floor 40.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technology for a pinch prevention device for aerial work vehicles. [Background technology]

[0002] Conventionally, technology for an aerial work platform vehicle equipped with a work platform has been publicly known, as described in Patent Document 1, for example.

[0003] Patent Document 1 describes a vehicle for working at height that is provided with a deck (working platform) that can be raised and lowered on a chassis that is equipped with a traveling device.

[0004] When performing high-altitude work using such an aerial work vehicle, there is a possibility that a worker on the deck may be caught between the deck and an object above when the deck is raised.

[0005] From a safety standpoint, it is conceivable to provide a device on the deck that will stop the deck from rising if the distance between the deck and the object falls below a predetermined distance. One such device is a rod-shaped member attached to the deck that stops the deck from rising if the tip of the rod comes into contact with the object.

[0006] However, when using such a device, it is possible that workability may be impaired if the worker wishes to get closer to the object. Also, from the viewpoint of workability, it is possible that safety may be impaired if the worker removes the device. For these reasons, there is a need for a pinch prevention device that can improve safety and workability when working at heights. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-31293 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and the problem it aims to solve is to provide a pinch prevention device that can improve the safety and workability of working at heights. [Means for solving the problem]

[0009] The problem to be solved by the present invention is as described above, and the means for solving this problem will now be described.

[0010] That is, in claim 1, there is provided a pinch prevention device mounted on the working platform of a vehicle for working at height, comprising: a detection unit that detects an object above the working platform without contact; a control unit that can stop the lifting of the working platform when the detection unit detects the object; and a release device that can release the stop of the lifting of the working platform by the control unit when a predetermined release operation is performed with the control unit stopping the lifting of the working platform. The release device includes a foot switch that can be operated by depressing the foot switch, and the release operation includes an operation of releasing the foot switch from being depressed. It is something.

[0011] In claim 2, the device is provided with an enabling switch that is displaced between a first position that is located when the switch is not pressed, a second position that is located when the switch is pressed with a first operating force, and a third position that is located when the switch is pressed with a second operating force that is greater than the first operating force, and the control unit stops the raising of the work platform when the enabling switch is in the first position or the third position.

[0012] In claim 3, A pinch prevention device mounted on the working platform of a vehicle for working at height, the device comprising: a detection unit that detects an object above the working platform without contact; a control unit that can stop the raising of the working platform when the detection unit detects the object; a release device that can release the stop of the raising of the working platform by the control unit when a predetermined release operation is performed with the control unit stopping the raising of the working platform; and an enable switch that is displaced to a first position when the switch is not pressed, a second position when the switch is pressed with a first operating force, and a third position when the switch is pressed with a second operating force that is greater than the first operating force, the control unit stops the raising of the working platform when the enable switch is in the first position or the third position, and the control unit further comprises a gripping unit that can be held by a worker to operate the switch of the enable switch, the gripping unit being installed at a position lower than the upper end of the handrail of the working platform. It is something.

[0013] In claim 4, The release device includes the enable switch, and the release operation includes an operation of moving the enable switch from the second position to the first position or the third position. It is something.

[0014] In claim 5, The release device includes a foot switch that can be operated by depressing the foot switch, and the release operation includes an operation of releasing the foot switch from being depressed. It is something. [Effects of the Invention]

[0015] The present invention has the following effects.

[0016] According to claim 1, the safety and workability of working at heights can be improved.

[0017] In claim 2, safety can be further improved.

[0018] In claim 3, This can improve safety and workability when working at heights, and can also prevent the hands of a worker holding the gripping part from being pinched by an object while the work platform is rising.

[0019] According to claim 4, safety can be further improved.

[0020] In claim 5, This can further improve safety. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a side view schematically showing an aerial work platform equipped with a pinch prevention device according to an embodiment of the present invention; [Figure 2] (a) Plan view showing the work floor and the controller. (b) Enlarged plan view showing the handrail and the controller. [Figure 3] FIG. [Figure 4] FIG. 1 is a block diagram showing a high-altitude work platform. [Figure 5] (a) Schematic diagram showing the enable switch in the first position, (b) Schematic diagram showing the enable switch in the second position, and (c) Schematic diagram showing the enable switch in the third position. [Figure 6] 4 is a timing chart showing an example of a process executed by the pinch prevention device. [Figure 7] 4 is a flowchart showing a process executed by the pinch prevention device. [Figure 8] 8 is a flowchart showing a continuation of FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0022] The following describes an aerial work vehicle 1 equipped with a pinch prevention device according to one embodiment of the present invention, using Figures 1 to 8. In the following description, the front-rear direction, left-right direction, and up-down direction are defined based on the arrows in the figures.

[0023] The vehicle for high-altitude work 1 shown in Figures 1 to 4 is a vehicle equipped with a mechanism for working at heights. As shown in Figure 1, the vehicle for high-altitude work 1 can raise and lower the part of the vehicle on which the worker sits (work platform 40) towards an object A (such as a beam or ceiling of a building) located above. The vehicle for high-altitude work 1 can also travel with the worker on board. The vehicle for high-altitude work 1 comprises a vehicle body 10, a controller 60, and a conversion harness 70.

[0024] 1 is the main structure of the aerial work vehicle 1. The vehicle body 10 is equipped with a traveling device 20, a lifting device 30, a work platform 40, and a control device 50.

[0025] The traveling device 20 is capable of traveling by wheels, etc. The traveling device 20 travels using power from a drive source, such as a motor.

[0026] The lifting device 30 raises and lowers the work platform 40, which will be described later. The lifting device 30 is provided on the upper part of the traveling device 20. The lifting device 30 is formed so as to be extendable and contractible in the vertical direction. The lifting device 30 is formed, for example, by a link mechanism.

[0027] 1 to 4 is raised and lowered by a lifting device 30. By raising the work platform 40 to a desired height with the lifting device 30, a worker standing on the work platform 40 can work at a height. The work platform 40 is equipped with a floor section 41, a handrail 42, an operating section 43, and a foot switch 44.

[0028] The floor section 41 shown in Figures 1 and 2(a) is the portion on which a worker stands. The floor section 41 is arranged so that the floor surface faces upward. The floor section 41 is provided above the lifting device 30. As shown in Figure 2(a), the floor section 41 is formed in a substantially rectangular shape (approximately oblong) in a plan view. The width dimension (left-right dimension) of the short side of the floor section 41 in a plan view is formed to be, for example, about 700 mm.

[0029] The handrail 42 prevents a worker from falling. The handrail 42 is formed to rise upward from the floor portion 41. The handrail 42 is formed around the entire periphery of the floor portion 41. The handrail 42 is formed in a fence shape.

[0030] The operating unit 43 shown in Fig. 2(a) is capable of operating the travel and lifting of the vehicle body 10. The operating unit 43 is located in the front portion of the work platform 40. Specifically, the operating unit 43 is provided in the front portion of the right handrail 42. The operating unit 43 has a lever that can operate travel (forward, backward, and right / left turns) by the traveling device 20, a switch that can operate lifting and lowering by the lifting device 30, an emergency stop switch that can stop lifting and lowering by the lifting device 30, and the like. The operating unit 43 is operated by the worker's fingers (for example, the fingers of the right hand).

[0031] 1, 2, and 4 can be operated by an operator by stepping on it with their foot. The foot switch 44 is formed, for example, in the shape of a pedal. The foot switch 44 is provided on the floor 41, for example, below the operation unit 43. The foot switch 44 is turned ON when the operator steps on it, and is turned OFF when the operator does not step on it (when the stepping operation is released).

[0032] 1 and 4 is a device related to control of the operation of the vehicle body 10. The control device 50 is provided, for example, in the traveling device 20. The control device 50 includes a power supply unit 51, a lower end position detection unit 52, and a control unit 53.

[0033] The power supply unit 51 supplies power used for operations such as running and lifting of the vehicle body 10. As the power supply unit 51, a predetermined storage battery can be used.

[0034] The bottom end position detection unit 52 is capable of detecting that the work platform 40 is at the bottom end position, which is the lowest position. When the work platform 40 is at the bottom end position, the lifting device 30 does not raise the work platform 40 at all. As the bottom end position detection unit 52, various sensors, switches, etc. that can detect the position of the work platform 40 can be used.

[0035] The control unit 53 is capable of executing processes related to control of the operation (travel and lifting) of the vehicle body 10. The control unit 53 has a predetermined arithmetic processing device. The control unit 53 is communicably connected to the traveling device 20, the lifting device 30, the operation unit 43, the foot switch 44, and the bottom end position detection unit 52 via predetermined wiring (signal lines).

[0036] The control unit 53 can control the operation of the vehicle body 10 (the traveling device 20 and the lifting device 30) based on the operation of the operation unit 43. The control unit 53 can also control the operation of the vehicle body 10 in response to a signal (operation permission output) from a controller 60, which will be described later.

[0037] Furthermore, the vehicle body 10 as described above can be operated not only by the operation unit 43 of the work platform 40, but also by an operation unit (not shown) provided on the lower side (traveling device 20). The control unit 53 can switch between a "lower operation mode" in which operation on the operation unit 43 of the work platform 40 is not permitted and operation of the vehicle body 10 is performed by the operation unit on the lower side, and a "normal mode" in which operation on the operation unit 43 of the work platform 40 is permitted.

[0038] The controller 60 shown in Figs. 1 to 5 restricts (stops) or releases the restriction on the movement of the vehicle body 10 (aerial work vehicle 1) based on the state of the worker on the work platform 40, the detection results of an object A above, etc. The controller 60 operates using power from the power supply unit 51. As shown in Fig. 2, the controller 60 is disposed in the front portion of the work platform 40. Specifically, the controller 60 is provided on the front handrail 42 at a position lower than the upper end of the handrail 42. The controller 60 includes a housing 61, an ultrasonic sensor 62, a grip unit 63, an enable switch 64, a display unit 65, a converter 66, and a control unit 67.

[0039] 2 and 3 forms the outer shell of the controller 60. The housing 61 is formed in a substantially rectangular box shape. The housing 61 is fixed to the front handrail 42 via a predetermined plate or the like.

[0040] The ultrasonic sensor 62 uses ultrasonic waves to detect whether an object A is located within a predetermined distance in the vertical direction. As shown in FIG. 2(b), the ultrasonic sensor 62 is provided on the right side (right end) of the top surface of the housing 61. In FIGS. 1, 2(a), and 3, the detection range of the ultrasonic sensor is indicated by a two-dot chain line. The ultrasonic sensor 62 has a maximum detection distance (maximum value of the detection range in the vertical direction) of approximately 2000 mm (see FIG. 1). The detection range of the ultrasonic sensor widens upward at a predetermined angle (e.g., approximately 11 degrees) in a side view (see FIG. 3). The detection range of the ultrasonic sensor 62 in a plan view has a maximum radius of approximately 400 mm (see FIG. 2(a)). Note that the above-mentioned detection range values ​​are merely examples, and various values ​​can be adopted for the detection range of the ultrasonic sensor 62. The ultrasonic sensor 62 is positioned in a position that makes it difficult to detect a worker on the work platform 40. Specifically, the ultrasonic sensor 62 is disposed so that its detection range is located in front of an operator who operates the operation unit 43 and the controller 60 in a normal posture (for example, standing posture) (see FIG. 1).

[0041] The grip portion 63 shown in FIGS. 2 and 3 is to be held (used as a handle) by the fingers (for example, the fingers of the left hand) of an operator. The grip portion 63 is formed in a shape in which a rod-shaped material with its longitudinal direction facing the front-rear direction is bent into a substantially inverted U shape. The grip portion 63 is made of a metal material. The grip portion 63 is positioned so that the hand, arm, etc. of an operator holding the grip portion 63 is unlikely to be positioned within the detection range of the ultrasonic sensor 62. Specifically, the grip portion 63 is provided on the left part (left end) of the top surface of the housing 61.

[0042] 3, the upper end of gripping portion 63 is located at a position lower than the upper end of handrail 42. The position (height) of the upper end of gripping portion 63 can be set at a height such that the hand of the worker holding gripping portion 63 is located at a position lower than the upper end of handrail 42 (for example, a position 100 mm or more lower than the upper end of handrail 42). By having the worker hold such gripping portion 63, unlike when holding handrail 42, for example, it is possible to prevent the worker's hand from being pinched between handrail 42 and object A.

[0043] The enable switch 64 shown in Figures 2 to 5 can be displaced to three positions depending on whether it is operated or not, or the magnitude of the operating force. The enable switch 64 is formed so that it can be pressed from above. The enable switch 64 can be switched between ON and OFF depending on the position. The enable switch 64 is provided on the top surface of the housing 61 to the right of the grip portion 63. The enable switch 64 is provided near the grip portion 63.

[0044] The enable switch 64 is formed so as to be pressable by a finger (for example, a thumb) of an operator while the operator is holding the grip portion 63. The operation of the enable switch 64 will be described in detail below with reference to FIG.

[0045] 5(a) is the position when the enable switch 64 is not being pressed. Specifically, the enable switch 64 is in the first position when the operating force applied to the enable switch 64 is less than 3 kN. In the first position, the enable switch 64 is OFF.

[0046] The second position shown in Figure 5(b) is the position when the enable switch 64 is pushed one step further from the first position. Specifically, the enable switch 64 is in the second position when the operating force applied to the enable switch 64 is equal to or greater than 3 kN and less than 13 kN. In the second position, the enable switch 64 is turned ON.

[0047] 5(c) is the position when the enable switch 64 is further pressed from the second position. Specifically, the enable switch 64 is in the third position when an operating force of 13 kN or more is applied to the enable switch 64. In the third position, the enable switch 64 is turned OFF.

[0048] An operator can operate the enable switch 64 to the second position or the third position by pressing the enable switch 64 with a finger while holding the grip portion 63. The positional relationship (placement, height, etc.) between the enable switch 64 and the grip portion 63 described above can be adopted so that when an operator holding the grip portion 63 presses the enable switch 64 naturally (with normal force), the enable switch 64 is in the second position. If an operator who presses the enable switch 64 to the second position presses it with even greater operating force (operating force of 13 kN or more) while holding the grip portion 63, the enable switch 64 can be in the third position. Furthermore, if the operator releases his or her hand from the grip portion 63, the enable switch 64 can be in the first position.

[0049] 3 and 4 displays the status of the aerial work platform 1. As shown in Fig. 3, the display 65 is provided on the rear surface of the housing 61. A predetermined lamp or the like can be used as the display 65.

[0050] The display unit 65 can display three messages: "Power," "Restricted," and "Operation Permitted." "Power" is displayed when power is being supplied to the aerial work platform 1 from the power supply unit 51 and "Normal Mode" is set. "Restricted" is displayed when the controller 60 is restricting the operation of the aerial work platform 1. "Operation Permitted" is displayed when the restriction by the controller 60 has been lifted.

[0051] 4 changes the voltage of the power supplied from the power supply unit 51. As the converter 66, a predetermined DC / DC converter can be used.

[0052] The control unit 67 is capable of executing processing based on the detection results of the ultrasonic sensor 62 and the state of the enable switch 64. The control unit 67 is built into the housing 61. The control unit 67 has a predetermined arithmetic processing device. A predetermined PLC controller (programmable logic controller) can be used as the control unit 67. The control unit 67 is communicably connected to the ultrasonic sensor 62, the enable switch 64, the display unit 65, and the converter 66 via predetermined wiring (signal lines).

[0053] The conversion harness 70 shown in Fig. 4 connects the vehicle body 10 and the controller 60 so that they can communicate with each other. The conversion harness 70 is connected to the vehicle body 10 and the controller 60 via a predetermined connector. As shown in Fig. 4, the power supply unit 51 and the converter 66 are connected via the conversion harness 70. The foot switch 44 and the control unit 53 are also connected to the control unit 67 via the conversion harness 70. The block diagram shown in Fig. 4 is a schematic diagram showing the connection relationships between the various parts of the aerial work platform 1.

[0054] The conversion harness 70 branches a wiring connected to an existing circuit used to control the vehicle body 10 (for example, a wiring connected to the foot switch 44), and connects the controller 60 to the branched wiring. By using the conversion harness 70, the controller 60 can be easily retrofitted without changing the existing circuit of the vehicle body 10.

[0055] The anti-trapping device includes, among the components constituting the vehicle for aerial work 1 as described above, the controller 60 and the foot switch 44. The anti-trapping device can execute processing to restrict (stop) or release the restriction on the operation of the vehicle body 10 (vehicle for aerial work 1) based on the state of the foot switch 44, the detection results of the ultrasonic sensor 62, and the state (position) of the enable switch 64.

[0056] Specifically, in the process, the control unit 67 of the controller 60 switches between a state in which operation permission is output to the control unit 53 of the vehicle body 10 (the operation permission output is turned ON) and a state in which operation permission is not output (the operation permission output is turned OFF), thereby restricting or canceling the restriction on the operation of the vehicle body 10. The operation permission is output in response to the operation of the operation permission unit (the foot switch 44 and the enable switch 64) (see FIG. 6).

[0057] When the operation permission is output, the operation of the traveling device 20 and the lifting device 30 based on the operation by the operation unit 43 is permitted. On the other hand, when the operation permission is not output, the operation of the traveling device 20 and the lifting device 30 based on the operation by the operation unit 43 is not permitted. In other words, the traveling and lifting operations are restricted.

[0058] Furthermore, during processing, the controller 60 can switch the state of the aerial work vehicle 1 to one of the "normal travel mode," "normal ascent mode," and "danger area mode" based on the detection results of the bottom end position detection unit 52 and the ultrasonic sensor 62 (see Figures 6 to 8). Each mode will be described in detail below using the timing chart in Figure 6.

[0059] The "normal travel mode" is a mode that is executed when the bottom end position detection unit 52 detects that the work platform 40 is at the bottom end position, but the ultrasonic sensor 62 does not detect that the distance to the object A is less than a predetermined distance. When the "normal travel mode" is being executed, the control unit 67 turns on the operation permission output when the foot switch 44 is on. This enables travel and lifting / lowering operations based on operation by the operation unit 43.

[0060] The "normal lifting mode" is a mode that is executed when the bottom end position detection unit 52 has not detected that the work platform 40 is at the bottom end position, and the ultrasonic sensor 62 has not detected that the distance to the object A is less than a predetermined distance. When the "normal lifting mode" is being executed, the control unit 67 turns on the operation permission output when both the foot switch 44 and the enable switch 64 are on. This enables lifting and lowering operations based on operation by the operation unit 43.

[0061] The "danger area mode" is a mode that is executed when the ultrasonic sensor 62 detects that the distance to the object A is less than a predetermined distance. When the "danger area mode" is executed, the control unit 67 turns off the operation permission output unless a predetermined release operation is performed. This restricts (stops) the lifting and lowering operation based on the operation by the operation unit 43.

[0062] Here, the release operation refers to the operation of pressing (re-depressing) the foot switch 44 and the enable switch 64 again. That is, after the "danger area mode" is executed, the control unit 67 turns on the operation permission output when the foot switch 44 and the enable switch 64 are each turned off at least once, and then both the foot switch 44 and the enable switch 64 are turned on simultaneously (when both the foot switch 44 and the enable switch 64 are in the on state). This releases the restriction on the lifting operation. Accordingly, when the worker desires to approach or move away from the object A above from the viewpoint of workability or the like while the lifting of the working platform 40 is stopped, the lifting of the working platform 40 can be permitted.

[0063] The following describes the processing executed by the controller 60 (control unit 67) using the flowcharts of FIGS.

[0064] The following process is executed, for example, when a worker on the work platform 40 performs a predetermined operation (for example, operation of the operation unit 43, the foot switch 44, the controller 60, etc.). In the following explanation, the vehicle body 10 is in "normal mode."

[0065] In step S10, the control unit 67 causes the display unit 65 to display "power supply." If the vehicle body 10 is in "lower operation mode" or if power is not being supplied to the aerial work platform vehicle 1 (the power supply is OFF), "power supply" will not be displayed. After executing the processing of step S10, the control unit 67 proceeds to the processing of step S11.

[0066] In step S11, the control unit 67 determines whether the operation permission output has been ON continuously for a predetermined time. If the control unit 67 determines that the operation permission output has not been ON continuously for the predetermined time, the control unit 67 proceeds to the processing of step S12. On the other hand, if the control unit 67 determines that the operation permission output has been ON continuously for the predetermined time, the control unit 67 proceeds to the processing of step S21.

[0067] In step S12, the control unit 67 determines whether or not the bottom end position detection unit 52 has detected that the work floor 40 is located at the bottom end position. If the control unit 67 determines that the bottom end position detection unit 52 has not detected that the work floor 40 is located at the bottom end position (non-detection), the control unit 67 proceeds to processing in step S13. On the other hand, if the control unit 67 determines that the bottom end position detection unit 52 has detected that the work floor 40 is located at the bottom end position, the control unit 67 proceeds to processing in step S22.

[0068] In step S13, the control unit 67 determines whether the ultrasonic sensor 62 has detected that the distance to the object A is equal to or shorter than a predetermined distance. The predetermined distance may be, for example, 1200 mm. Note that various values ​​may be used for the predetermined distance, taking into consideration the safety of the operator.

[0069] If the control unit 67 determines that the ultrasonic sensor 62 has detected that the distance to the object A is less than or equal to a predetermined distance, the control unit 67 proceeds to processing in step S14. In this case, the vehicle for aerial work 1 executes the "danger area mode." On the other hand, if the control unit 67 determines that the ultrasonic sensor 62 has not detected that the distance to the object A is less than or equal to a predetermined distance (non-detection), the control unit 67 proceeds to processing in step S17. In this case, the vehicle for aerial work 1 executes the "normal ascent / descent mode."

[0070] In step S14, the control unit 67 switches the operation permission output to OFF (a state in which operation permission is not output). In this case, the control unit 67 does not operate the traveling device 20 and the lifting device 30 even if the operation unit 43 is operated. After executing the process of step S14, the control unit 67 proceeds to the process of step S15.

[0071] In step S15, the control unit 67 displays "Restricted" on the display unit 65. After executing the process of step S15, the control unit 67 proceeds to the process of step S16.

[0072] In step S16, the control unit 67 determines whether the foot switch 44 and the enable switch 64 have each been turned OFF at least once. If the control unit 67 determines that the foot switch 44 and the enable switch 64 have each been turned OFF at least once, the control unit 67 proceeds to the processing of step S17. On the other hand, if the control unit 67 determines that at least one of the foot switch 44 and the enable switch 64 has not been turned OFF, the control unit 67 repeats the processing of step S16.

[0073] In step S17, the control unit 67 determines whether the enable switch 64 is ON. If the control unit 67 determines that the enable switch 64 is ON, the control unit 67 proceeds to the processing of step S18. On the other hand, if the control unit 67 determines that the enable switch 64 is not ON, the control unit 67 repeats the processing of step S17.

[0074] In step S18, the control unit 67 determines whether the foot switch 44 is ON. When the process moves from step S17 to step S18, the control unit 67 determines whether the foot switch 44 is ON when the enable switch 64 is ON (whether the foot switch 44 and the enable switch 64 are ON simultaneously). If the control unit 67 determines that the foot switch 44 is ON, the control unit 67 proceeds to processing in step S19. On the other hand, if the control unit 67 determines that the foot switch 44 is not ON, the control unit 67 repeats the processing in step S18.

[0075] In step S19, the control unit 67 switches the operation permission output ON (a state in which operation permission is output). That is, when the release operation by pressing (re-depressing) the foot switch 44 and the enable switch 64 described above (step S16: YES, steps S17 and S18) is performed, the control unit 67 turns the operation permission output ON. In this case, the control unit 67 operates the traveling device 20 and the lifting device 30 in accordance with the operation of the operating unit 43. After executing the process of step S19, the control unit 67 proceeds to the process of step S20.

[0076] In step S20, the control unit 67 displays "Operation Permitted" on the display unit 65. After executing the process of step S20, the control unit 67 ends the process.

[0077] In step S22, which is performed if it is determined in step S12 that "the bottom end position detection unit 52 has detected that the work platform 40 is located at the bottom end position," the control unit 67 determines whether the ultrasonic sensor 62 has detected that the distance to the object A is less than or equal to a predetermined distance. If the control unit 67 determines that the ultrasonic sensor 62 has detected that the distance to the object A is less than or equal to the predetermined distance, it proceeds to processing in step S14. On the other hand, if the control unit 67 determines that the ultrasonic sensor 62 has not detected that the distance to the object A is less than or equal to the predetermined distance (non-detection), it proceeds to processing in step S18. In this case, the vehicle for aerial work 1 is put into "normal travel mode."

[0078] In step S21, which is performed if it is determined in step S11 that the operation permission output has been continuously ON for a predetermined time, the control unit 67 determines whether the foot switch 44 and the enable switch 64 have been simultaneously turned OFF. If the control unit 67 determines that the foot switch 44 and the enable switch 64 have been simultaneously turned OFF, the control unit 67 proceeds to processing in step S12. On the other hand, if the control unit 67 determines that the foot switch 44 and the enable switch 64 have not been simultaneously turned OFF, the control unit 67 proceeds to processing in step S14.

[0079] Here, if the operation permission output remains ON for a predetermined time (step S11: YES), it is assumed that an abnormality has occurred, such as an object being placed on each switch causing the operation permission to continue to be output. According to the above process, in such a case, if there is no operation in step S21, the operation permission output is turned OFF (step S14), and the operation of the work platform 40 can be stopped. Note that various values ​​can be used for the predetermined time, taking into consideration the safety of the worker.

[0080] According to the processing of the controller 60 as described above, when the "danger area mode" based on the detection result of the ultrasonic sensor 62 is executed, the operation of the work floor 40 is stopped (step S13: YES, step S22: YES, step S14), thereby preventing the worker from being pinched between the work floor 40 and the object A, thereby improving safety.

[0081] Furthermore, in the above process, when the "normal lifting mode" is being executed, the operation permission output is turned ON if the foot switch 44 is ON and the enable switch 64 is ON (second position) (steps S17 to S19). That is, the configuration is such that the operation of the work platform 40 is stopped if the enable switch 64 is OFF (first position or third position). As a result, even if the ultrasonic sensor 62 does not detect the object A, if the worker comes into contact with the object A, or if the worker senses an abnormality and releases his / her hand from the enable switch 64 or presses it hard (when it is in the first position or the third position), the operation of the work platform 40 can be stopped. In this way, the operation of the work platform 40 can be stopped by two means.

[0082] As described above, if an operator senses an abnormality while holding the enable switch 64 in his / her hand (operating it to the second position), the operator is expected to either press the enable switch 64 harder (operating it to the third position) or release the enable switch 64 (operating it to the first position). If the operator is pinched from above by the object A while the work platform 40 is being raised, the operator will generally press (depress) the switch, and it is expected that the operator will find it difficult to perform the opposite action of releasing the switch. According to this embodiment, in addition to releasing the operator's hand (operating it to the first position), the operation of the work platform 40 can also be stopped by the operator pressing the enable switch 64 harder (operating it to the third position), thereby further improving safety.

[0083] Furthermore, if the worker senses something is wrong, the operation of the work platform 40 can also be stopped by turning off the foot switch 44 (by removing the foot). However, if the worker is pinched from above by the object A, as described above, it is expected that the worker will find it difficult to remove his or her foot, which is the opposite action to stepping in. According to this embodiment, as described above, the operation of the work platform 40 can also be stopped by firmly pressing the enable switch 64 (by operating it to the third position), thereby further improving safety.

[0084] Furthermore, in the above process, when the "danger area mode" is being executed, if the worker desires to approach the object A above with the operation of the work platform stopped from the viewpoint of workability or the like, by executing a cancellation operation (step S16: YES, step S17: YES, step S18: YES), the operation of the work platform 40 can be permitted even when the "danger area mode" is being executed, thereby improving workability.

[0085] The above-mentioned release operation includes an operation in which the worker intentionally presses the enable switch 64 again. In other words, the above-mentioned release operation includes an operation in which the enable switch 64 is once turned OFF (first position or third position) and then turned ON again (second position). This makes it possible to prevent the stop of the operation of the work platform 40 from being released due to an erroneous operation.

[0086] Furthermore, if the worker comes into contact with the object A when the operation of the work platform 40 is released from the stopped state, the worker who senses something abnormal can stop the operation of the work platform 40 by removing his / her hand from the enable switch 64 or by pressing it hard.

[0087] Furthermore, the controller 60 according to this embodiment positions the ultrasonic sensor 62 in a position where it is difficult to detect a worker on the work platform 40. This makes it possible to prevent the ultrasonic sensor 62 from detecting a worker who is mistakenly located within the detection range and stopping the operation of the work platform 40. Furthermore, if a worker is located within the detection range, it is assumed that the worker has fallen toward the ultrasonic sensor 62. According to this embodiment, the operation of the work platform 40 can be stopped even in such a case.

[0088] As described above, the pinch prevention device according to this embodiment has the following features: A pinch prevention device (controller 60, foot switch 44) mounted on a work platform 40 of an aerial work platform 1, A detection unit (ultrasonic sensor 62) that detects an object A above the work floor 40 in a non-contact manner; A control unit 67 that can stop the lifting of the work platform 40 when the detection unit (ultrasonic sensor 62) detects the object A (step S13: YES, step S14); a release device (enable switch 64, foot switch 44) that can release the stop of the raising of the work platform 40 by the control unit 67 when a predetermined release operation is performed with the control unit 67 stopping the raising of the work platform 40 (step S16: YES, step S17: YES, step S18: YES, step S19); It is equipped with the following.

[0089] This configuration can improve the safety and workability of working at heights. That is, by stopping the ascent of the work platform 40 when the detection unit detects an object A above, it is possible to prevent the worker from being pinched between the work platform 40 and the object A, thereby improving safety. Furthermore, if the worker wishes to approach or move away from the object A above while the ascent of the work platform 40 is stopped, the worker can allow the work platform 40 to rise by releasing the stop on the ascent of the work platform 40 using the release device (enable switch 64). This can improve workability.

[0090] In addition, the anti-pinch device an enable switch 64 that is displaced between a first position that is located when the switch is not pressed, a second position that is located when the switch is pressed with a first operating force (an operating force of 3 kN or more and less than 13 kN), and a third position that is located when the switch is pressed with a second operating force (an operating force of 13 kN or more) that is greater than the first operating force; The control unit 67 When the enable switch 64 is in the first position or the third position, the lifting of the work platform 40 is stopped.

[0091] This configuration can further improve safety. In other words, by using the enable switch 64 to stop the lifting of the work platform 40, even if the detection unit does not detect the object A, if the worker comes into contact with the object A, the worker who senses something is wrong can stop the lifting of the work platform 40 by either removing his / her hand from the enable switch 64 or by pressing it hard. In this way, the lifting of the work platform 40 can be stopped by two means.

[0092] Further, the release device The enable switch 64 is included. The release operation is This includes an operation of changing the enable switch 64 from the second position to the first position or the third position (step S16: YES).

[0093] This configuration can further improve safety. That is, the configuration is such that the stop on the ascent of the work platform 40 is released on the condition that the worker intentionally operates the enable switch 64. This makes it possible to prevent the stop on the ascent of the work platform 40 from being released due to an erroneous operation. Furthermore, if the worker comes into contact with the object A when the stop on the ascent of the work platform 40 is released, the worker, sensing an abnormality, can stop the ascent of the work platform 40 by removing his / her hand from the enable switch 64 or by pressing it hard.

[0094] Further, the release device A foot switch 44 that can be operated by stepping on it is included, The release operation is This includes the operation of releasing the foot switch 44 (step S16: YES).

[0095] This configuration can further improve safety. That is, the stop on the lifting of the work platform 40 is released only when the worker intentionally operates the enable switch 64 and the foot switch 44 in conjunction with each other. This makes it possible to prevent the stop on the lifting of the work platform 40 from being released due to an erroneous operation.

[0096] In addition, the anti-pinch device The device includes a grip portion 63 that can be held by an operator to operate the enable switch 64, The gripping portion 63 is It is installed at a position lower than the upper end of the handrail 42 of the work floor 40.

[0097] With this configuration, it is possible to prevent the hand of the worker holding the gripping portion 63 from being pinched by the object A while the work platform 40 is being raised.

[0098] The ultrasonic sensor 62 according to this embodiment is one embodiment of a detection unit according to the present invention. The enable switch 64 according to this embodiment is one embodiment of a release device according to the present invention.

[0099] Although the embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0100] For example, the operation performed in the release operation is not limited to that shown in this embodiment, and various operations can be adopted. Also, in this embodiment, an example is shown in which the release operation is performed using both the foot switch 44 and the enable switch 64, but the present invention is not limited to this configuration. For example, the release operation may be performed using only the enable switch 64.

[0101] In addition, in this embodiment, an example has been shown in which the enable switch 64 is provided in the controller 60, but the present invention is not limited to this configuration. For example, instead of the enable switch 64, a switch that switches between ON and OFF in two stages may be used.

[0102] In addition, in this embodiment, an example has been shown in which the detection unit is the ultrasonic sensor 62, but the configuration is not limited to this. As the detection unit, various detection units capable of detecting that the target A is located within a predetermined distance, such as an infrared sensor or a laser rangefinder, can be used.

[0103] In addition, in the present embodiment, an example has been shown in which the vehicle main body 10 and the controller 60 are connected using the conversion harness 70, but the present invention is not limited to such a configuration. For example, the vehicle main body 10 and the controller 60 may be directly connected without using the conversion harness 70. [Explanation of symbols]

[0104] 1. Aerial work platform 10 Vehicle body 44 Footswitch 60 Controller 62 Ultrasonic Sensor 64 Enable switch

Claims

1. A pinch prevention device mounted on the work platform of a high-altitude work vehicle, a detection unit that detects an object above the work floor in a non-contact manner; a control unit that can stop the lifting of the work platform when the detection unit detects the object; A release device that can release the stop of the raising of the work platform by the control unit when a predetermined release operation is performed in a state in which the control unit has stopped the raising of the work platform; Equipped with The release device is Includes a foot switch that can be operated by stepping on it, The release operation is and releasing the foot switch. Anti-pinch device.

2. The device includes an enable switch that is displaced between a first position that is located when the switch is not pressed, a second position that is located when the switch is pressed with a first operating force, and a third position that is located when the switch is pressed with a second operating force that is greater than the first operating force, The control unit When the enable switch is in the first position and the third position, the lifting of the work platform is stopped. The anti-trap device according to claim 1.

3. A pinch prevention device mounted on the work platform of a high-altitude work vehicle, a detection unit that detects an object above the work floor in a non-contact manner; a control unit that can stop the lifting of the work platform when the detection unit detects the object; A release device that can release the stop of the raising of the work platform by the control unit when a predetermined release operation is performed in a state in which the control unit has stopped the raising of the work platform; an enable switch that is displaced between a first position that is located when the switch is not pressed, a second position that is located when the switch is pressed with a first operating force, and a third position that is located when the switch is pressed with a second operating force that is greater than the first operating force; Equipped with The control unit When the enable switch is in the first position and the third position, the lifting of the work platform is stopped; The device further includes a grip portion that can be held by an operator to operate the switch of the enable switch, The gripping portion is It is installed at a position lower than the upper end of the handrail of the work floor. Anti-pinch device.

4. The release device is The enable switch is included. The release operation is an operation of changing the enable switch from the second position to the first position or the third position, The pinch prevention device according to claim 2 or 3.

5. The release device is Includes a foot switch that can be operated by stepping on it, The release operation is and releasing the foot switch. The anti-trap device according to claim 3.

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