JP2020007128A - Safety device for high lift work vehicle - Google Patents

Abstract

To provide a safety device for a high lift work vehicle, which is able to speedily restrict travel of a vehicle body when an overturn prevention plate comes into contact with the ground.SOLUTION: While kept in a spread-out position, an overturn prevention plate 110 is mounted on a plate mounting part 2b of a vehicle body 2 so as to be movable upward by a predetermined amount. The plate mounting part 2b is installed with a limit switch 150A that detects an upward movement of the overturn prevention plate 110. In addition, a travel restricting device is provided for restricting travel of a vehicle body 2 when upward movement of the overturn prevention plate 110 is detected by the limit switch 150A.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a safety device for an aerial work vehicle provided with a fall prevention plate.

  An aerial work platform capable of vertically raising and lowering a worktable is configured to be able to run while the workbench is moved to a high position by extending a lifting device, for example, for maintenance of lighting mounted on a ceiling of a gymnasium. It is used for work and for putting materials in and out of shelves provided in warehouses. In such a high-altitude work vehicle, when the wheel enters a portion (hereinafter referred to as a “recess”) that is lower than the surroundings, such as a dent or a step, with the elevating device raised, the vehicle body is greatly inclined and stable. May deteriorate. Therefore, when the elevating device is extended, a plate-shaped fall prevention plate is arranged between the front and rear wheels at the lower part of the vehicle body, and even if the wheel enters the recess, the fall prevention plate is in contact with the ground (floor surface). 2. Description of the Related Art There is known an aerial work vehicle provided with an overturn prevention device (also referred to as a “pothole protector”) that abuts and supports a vehicle body to prevent the vehicle body from leaning significantly. Such a fall prevention device is configured, for example, to expand and retract a fall prevention plate in accordance with a lifting operation of a lifting device (see, for example, Patent Document 1).

  In order to prevent the vehicle from continuing to travel while the vehicle body is tilted greatly with the elevating device extended, aerial work vehicles equipped with safety devices that perform travel restrictions such as stopping the vehicle when the vehicle body tilts more than a certain amount are also available. Are known. Such a safety device is configured, for example, to detect a tilt angle of the vehicle body by a tilt angle detector attached to the vehicle body, and to perform travel restriction when the tilt angle exceeds a predetermined reference angle. (See, for example, Patent Document 2).

US Patent Application Publication No. 2005/0224290 JP-A-2000-281295

  There is also known an aerial work vehicle equipped with both the above-mentioned overturn prevention device and safety device. By equipping both devices, for example, when the wheels enter the recess and the vehicle body tilts, the overturn prevention plate contacts the ground to prevent the vehicle body from overturning, and the safety device regulates the running of the vehicle body By doing so, an effect of preventing the vehicle body from continuing running with the fall prevention plate in contact with the ground is expected. However, even when the wheels enter the recess and the vehicle body tilts and the overturn prevention plate comes into contact with the ground, the vehicle body tilt angle at that time is small and exceeds the reference angle at which the travel is restricted by the safety device. Because there is not, running regulation may not be enforced promptly. In this case, the vehicle body travels while the overturn prevention plate is in contact with the ground, and the wheels further enter the recessed portion, and the inclination of the vehicle body becomes large, which may cause the vehicle to fall.

  The present invention has been made in view of such a problem, and provides a safety device for an aerial work vehicle capable of promptly regulating the running of a vehicle body when a fall prevention plate comes into contact with the ground. The purpose is to:

A safety device for an aerial work vehicle according to the present invention includes a vehicle body having front and rear wheels that can travel, a lifting device provided on the vehicle body, and a working device that is lifted and lowered by the lifting device (for example, an embodiment) A work platform 5) having an aerial work platform, the lower part of the vehicle body between the front and rear wheels,
It is swingably connected around an axis extending in the front-rear direction, swings inward and swings to a storage position located along the lower surface of the vehicle body and to a deployment position in which the lower end approaches the ground by swinging downward. A safety device for an aerial work vehicle having a movable overturn prevention plate, wherein the overturn prevention plate is configured to be movable upward by a predetermined amount with respect to the vehicle body in a state where the overturn prevention plate is located at the deployed position. Movement detection means (for example, limit switch 150A in the embodiment) for detecting that the fall prevention plate has moved upward in the deployed position, and when the movement detection means detects upward movement of the fall prevention plate. In addition, a travel regulation means (for example, the travel regulation control device 210 in the embodiment) for regulating the travel of the vehicle body is provided.

  In the safety device for an aerial work vehicle according to the present invention, the overturn prevention plate is provided on one of the vehicle body and the overturn prevention plate, and extends vertically up and down in a state where the overturn prevention plate is located at the deployed position. An elongated hole (for example, a pivot hole 2e in the embodiment) that penetrates, and a shaft that is provided on the other of the vehicle body and the overturn prevention plate and that is inserted into the elongated hole so as to be vertically movable relative to the elongated hole. It is preferable to be connected to the vehicle body by a member (for example, the pivot pin 116 in the embodiment) so as to be movable upward by a predetermined amount.

  In the safety device for an aerial work vehicle according to the present invention, the traveling restricting unit may be configured to move the vehicle body when the upward movement of the fall prevention plate is continuously detected by the movement detecting unit for a predetermined time or more. Is preferable.

  According to the safety device for an aerial work vehicle according to the present invention, the overturn prevention plate is configured to be able to move upward with respect to the vehicle body in a state where the overturn prevention plate is located at the deployment position. When the fall-prevention plate comes into contact with the ground, for example, when the wheel enters the concave portion in this state, the fall-prevention plate moves upward, and a movement detection means for detecting this movement is provided. It can be determined that the fall prevention plate has come into contact with the ground by detecting that the vehicle has fallen. Further, since the travel detecting means is provided with travel restricting means for restricting the traveling of the vehicle body when the upward movement of the fall prevention plate is detected by the movement detection means, the fall prevention plate comes into contact with the ground due to the wheel entering the recess. In this case, it becomes possible to quickly regulate the traveling of the vehicle body regardless of the inclination angle of the vehicle body.

  In the safety device for an aerial work vehicle according to the present invention, the overturn prevention plate is formed by a long hole provided on one of the vehicle body and the overturn prevention plate, and a shaft member provided on the other of the vehicle body and the overturn prevention plate. Is configured to be movably connected upward by a predetermined amount, a mechanism for enabling the overturn prevention plate to move upward can be easily configured. Further, the manufacturing cost can be suppressed by simplifying the configuration.

  In the safety device for an aerial work vehicle according to the present invention, the travel restricting means restricts the travel of the vehicle body when the upward movement of the fall prevention plate is continuously detected by the movement detection means for a predetermined time or more. By such a configuration, when the fall prevention plate instantaneously moves upward and immediately returns to the original position, for example, when the wheel enters the recess, but immediately escapes from the recess. Can prevent the vehicle body from being restricted.

1 is a side view of an aerial work vehicle provided with a safety device for an aerial work vehicle according to the present invention, showing a state where a workbench is stored. FIG. 2 is a side view of the aerial work vehicle, showing a state where a work table is moved upward. It is a perspective view showing the body of the above-mentioned aerial work vehicle. It is a perspective view showing the composition of the fall prevention device with which the above-mentioned work platform equipment is equipped when it sees from the vehicles front side. It is a perspective view showing composition of the above-mentioned fall prevention device in the state where it saw from the vehicles back side. It is a side view showing the composition of the above-mentioned fall prevention device. FIG. 7 is a cross-sectional view of the overturn prevention device taken along a line AA in FIG. 6, showing a state in which the overturn prevention plate is swung to a storage position. It is sectional drawing which cut | disconnects and shows the said fall prevention device in the position of the AA of FIG. 6, and is a figure which shows the state which rock | fluctuated and moved the fall prevention plate to the deployment position. FIG. 2 is a perspective view showing a configuration of a lower portion of the vehicle body. FIG. 10 is an enlarged perspective view of a main part of FIG. 9, showing a state in which a fall prevention plate is removed from a vehicle body. It is a block diagram which shows the relationship between the driving | running | working control apparatus with which the said aerial work vehicle is equipped, and related equipment. It is a flow chart which shows the flow of the run regulation processing performed by the above-mentioned run regulation device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 3 show an aerial work vehicle 1 equipped with a safety device for an aerial work vehicle according to the present invention (configured to include a fall prevention device 100 and a travel restriction device 210 to be described later). First, the overall configuration of the aerial work vehicle 1 will be briefly described with reference to these drawings. In the following description, the direction of arrow F in FIG. The aerial work vehicle 1 has front and rear wheels 3a and 3b on both front and rear left and right sides of a vehicle body 2, steers a front wheel 3a in a left and right direction, and drives a rear wheel 3b by a driving motor (not shown) to run. It is configured to be possible. A telescoping mast-type elevating device 4 is mounted on the vehicle body 2, and a workbench 5 for mounting a worker is mounted on the elevating device 4.

The lifting device 4 is configured to include a telescopic mast 6 configured by telescopically nesting a plurality of mast members 6a to 6e, and a telescopic mechanism (not shown) arranged in the telescopic mast 6. You. In the telescopic mast 6, the lower end of the first-stage mast member 6 a is fixed to the vehicle body 2, and the worktable 5 is fixed to the fifth-stage mast member 6 e. Further, a handrail 7 having a substantially U-shape in plan view is attached to the mast member 6e and the floor surface of the worktable 5 so as to surround the worker boarding the worktable 5.

  An operation device 8 is provided on the work table 5, and when the operator on the work table 5 operates the operation device 8, the expansion and contraction mechanism of the lifting device 4 is operated to expand and contract the expansion mast 6. Thus, the work table 5 can be vertically moved up and down to an arbitrary height to perform work at a high place. Further, by operating the operating device 8, the rear wheels 3b can be driven and the front wheels 3a can be steered, so that the work platform 1 can be run even when the work platform 5 is moved to a high place. it can. A control box 9 (see FIG. 1) containing a control board and the like is installed inside the vehicle body 2.

  On both left and right sides of the vehicle body 2, between the front and rear wheels 3a and 3b, between the vehicle body 2 and the ground, a rollover prevention plate 110 which constitutes a part of the rollover prevention device 100 is arranged to be deployable and retractable. ing. Hereinafter, the overturn prevention device 100 will be described with reference to FIGS. 4 to 10 additionally. As shown in FIG. 4, the overturn prevention device 100 includes a pair of left and right overturn prevention plates 110, a pair of left and right drive arms 120, a connection link member 130, a storage operation section 140, and limit switches 150A and 150B. It is composed.

The overturn prevention plate 110 is formed of an elongated plate-shaped member extending in the vehicle front-rear direction. The overturn prevention plate 110 has a pivotal connection portion 111 formed of a single plate-like member at the front end thereof, and a pair of front and rear plate-like members 112a and 112b at the rear end thereof (see FIG. 9). Is provided. The pivot portion 111 is swingably attached to a plate attachment portion 2a (see FIG. 7) formed at a front portion of the vehicle body 2. Specifically, the pivot portion 111 has a pivot hole 113 (see FIG. 5) penetrating in the vehicle front-rear direction, and the plate mounting portion 2a has a pivot hole facing the pivot hole 113. A hole (not shown) is formed. The pivotal connection portion 111 is swingably attached to the plate mounting portion 2a via a columnar pivoting pin 115 (see FIG. 4) inserted into the pivotal connection hole 113 and the pivotal connection hole of the plate mounting portion 2a. It is attached.

  The pivot portion 112 is swingably attached to a plate attachment portion 2b formed at a lower portion on both right and left sides of the vehicle body 2. Specifically, the pivotal connection portion 112 (the plate-like members 112a and 112b) has a pivotal connection hole 114 (see FIG. 5) that penetrates forward and backward. A pivot hole 2e (see FIG. 10) facing 114 is formed. The pivot portion 112 is arranged such that a pair of plate members 112a and 112b sandwich the plate mounting portion 2b, and has a columnar pivot pin 116 (FIG. 9) inserted through the pivot holes 114 and 2e. ) Is swingably attached to the plate attaching portion 2b. The pivot hole 114 of the pivot portion 112 is formed as a round hole having an inner diameter substantially the same as the outer diameter of the pivot pin 116, while the pivot hole 2e of the plate mounting portion 2b is formed as shown in FIG. As shown in FIG. 3, the hole is formed as a long hole extending vertically. Therefore, the pivot pin 116 is located within a distance (hereinafter, referred to as a “predetermined amount”) corresponding to the difference between the vertical length of the pivot hole 2 e and the outer diameter of the pivot pin 116. 2e and the plate mounting portion 2b (vehicle body 2) are relatively movable in the vertical direction.

  As shown in FIG. 3, the fall prevention plate 110 is arranged so as to be located between the front and rear wheels 3a, 3b, and a swing axis extending in the vehicle front-rear direction with the center lines of the pivot pins 115, 116. As shown in FIG. 7, the swinging direction is swung between a deployment position in which the short direction extends substantially vertically downward to the ground (see FIG. 8) and a storage position (see FIG. 7) in which the short direction extends substantially horizontally substantially in parallel with the ground. . The fall prevention plate 110 is arranged such that, when it is in the deployed position, the distance between the lowermost end surface of the fall prevention plate 110 and the ground is within a predetermined range. In addition, in the state where the overturn prevention plate 110 is located at the deployed position, the portion provided with the pivotal connection portion 112 can be moved upward by the above-described predetermined amount.

  The pair of left and right drive arms 120 are arranged in a C shape when viewed from the front. The drive arm 120 is formed in a bent plate shape, and a pivot pin 121 is provided at a position inside a substantially central portion in the longitudinal direction. The drive arm 120 is formed by inserting a pivot pin 121 into a pivot hole (not shown) formed in a drive arm attachment portion 2c fixed to the vehicle body 2 (plate attachment portion 2a). 2c so as to be swingable. Accordingly, the pair of left and right drive arms 120 has an open leg position (see FIG. 7) in which the respective inner lower ends are separated from each other in the left-right direction, and a closed leg position (FIG. 8) in which the respective inner lower ends are closer in the left and right direction. ). A torsion coil spring 123 (see FIG. 6) for urging the drive arm 120 to swing to the open position is attached to a pivotal connection between the drive arm 120 and the drive arm attachment portion 2c. I have.

  The connection link member 130 is formed in an elongated plate shape, and has pivot connection holes 131 and 132 (see FIGS. 4 and 5) at both ends thereof. The connecting link member 130 is swingably attached to the lower inside portion of the drive arm 120 via a pivot pin 133 (see FIG. 5) inserted into the pivot hole 131, and is connected to the pivot hole 132. It is swingably attached to the pivotal connection portion 111 of the overturn prevention plate 110 via a pivotal connection pin 134 (see FIG. 4) inserted therethrough.

As shown in FIG. 7, the storage operation section 140 includes a cylindrical holding pipe 141 fixed to the pipe mounting section 2 d of the vehicle body 2, and is inserted into the upper end side of the holding pipe 141 to vertically move inside the holding pipe 141. A movable cylindrical upper moving member 142, a cylindrical lower moving member 143 inserted into the lower end of the holding tube 141 and movable vertically within the holding tube 141, and a lower end of the lower moving member 143 And a coil spring (not shown) disposed between the upper moving member 142 and the lower moving member 143 or between the upper moving member 142 and the pressing plate 144. Is done.

  As shown in FIG. 10, the limit switch 150 </ b> A includes a sealing case 151, a roller-mounted head 152 movably attached to the sealing case 151, and a movement of the roller-mounted head 152 stored in the sealing case 151. And a microswitch (not shown) that opens and closes the contacts accordingly. The limit switch 150A is attached to the plate attaching portion 2b as a plate movement detector for detecting the upward movement of the overturn prevention plate 110 located at the deployed position. That is, when the pivot pin 116 of the pivot portion 112 of the fall prevention plate 110 moves to the upper end side of the pivot hole 2e of the plate mounting portion 2b, the limit switch 150A causes the head 152 with roller to pivot the pivot portion 112 ( When the pivot pin 116 moves to the lower end side of the pivot hole 114 in contact with the plate-like member 112b), the head 152 with a roller separates from the pivot portion 112. When the roller-mounted head 152 is in contact with the pivot 112, a detection signal is output from the microswitch. When the roller-head 152 is away from the pivot 112, the detection signal is output from the microswitch. It is not output.

  The limit switch 150B has the same configuration as the limit switch 150A, and is attached to the drive arm 120 as a plate deployment storage detector that detects whether or not the overturn prevention plate 110 is located at the deployment position ( 7 and 8). That is, when the tip-over prevention plate 110 moves to the deployed position, the limit switch 150B causes the head 152 with roller to abut on the side surface of the pivot pin 121 of the drive arm 120 (see FIG. 8), and the tip-off prevention plate 110 When moved to the storage position, the head with roller 152 is separated from the side surface of the pivot pin 121 of the drive arm 120 (see FIG. 7). When the head with roller 152 is in contact with the side surface of the pivot pin 121, a detection signal is output from the micro switch. When the head with roller 152 is away from the side surface of the pivot pin 121, the micro switch is output. Does not output a detection signal.

  Next, the operation of storing and deploying the fall prevention plate 110 in the fall prevention device 100 will be described. First, in the retracted state where the expandable mast 6 is retracted and the worktable 5 is closest to the vehicle body 2 (see FIG. 1), the lower surface of the worktable 5 comes into contact with the upper end of the upper moving member 142 of the storage operation unit 140. Then, the upper moving member 142 is pushed down (see FIG. 7). When the upper moving member 142 is pushed down, the lower moving member 143 and the pressing plate 144 are pushed down via a coil spring (not shown). The depressed pressing plate 144 contacts the inner upper end 124 of the drive arm 120 from above, and presses the inner upper end 124 downward.

  The drive arm 120 whose inner upper end 124 is pressed downward by the pressing plate 144 swings around the center line of the pivot pin 121 against the urging force of the torsion coil spring 123 and moves to the open leg position. In conjunction with the swing movement of the drive arm 120 to the open position, the pivotal connection portion 111 connected to the drive arm 120 by the connection link member 130 moves together with the fall prevention plate 110 around the center line of the pivotal pin 115. Rocks. As a result, the fall prevention plate 110 swings and moves to a storage position in which the short side direction extends substantially horizontally with respect to the ground. In this storage position, the fall prevention plate 110 is stored along the lower surface of the vehicle body 2, so that a clearance between the lower surface of the vehicle body 2 and the ground can be secured, and the normal traveling of the aerial work vehicle 1 Not hinder.

Next, when the operating device 8 provided on the worktable 5 is operated and the extension mechanism of the elevating device 4 starts extension operation, the extension mast 6 is extended and the worktable 5 moves upward (see FIG. 2). ). The upward movement of the worktable 5 eliminates the state in which the upper moving member 142 of the storage operation unit 140 is pressed downward by the worktable 5. As a result, the downward pressing force acting on the inner upper end 124 of the drive arm 120 via the upper moving member 142, the coil spring (not shown), the lower moving member 143, and the pressing plate 144 is eliminated. The drive arm 120 swings around the center line of the pivot pin 121 by the urging force of the torsion coil spring 123 and moves to the closed position.

  In conjunction with the swing movement of the drive arm 120 to the closed position, the pivotal connection portion 111 connected to the drive arm 120 by the connection link member 130 swings around the center line of the pivotal pin 115 together with the fall prevention plate 110. Move. As a result, the fall prevention plate 110 swings to a deployed position in which the short side direction extends substantially vertically downward with respect to the ground. As described above, when the telescopic mast 6 is extended by extending the telescopic mechanism of the elevating device 4, the overturn prevention plate 110 is automatically deployed to the deployed position. Therefore, when the aerial work vehicle 1 travels in a state where the overturn prevention plate 110 is located at the deployed position, and one of the wheels 3a, 3b enters the recess and the vehicle body 2 starts to tilt, the overturn prevention plate 110 is moved to the ground. And supports the vehicle body 2 in contact with the vehicle body, so that the vehicle body 2 can be prevented from tilting more than that.

  When the fall prevention plate 110 located at the deployed position comes into contact with the ground, the fall prevention plate 110 (the portion provided with the pivotal connection portion 112) moves upward by a predetermined amount. When the overturn prevention plate 110 moves upward, the fact is detected by the limit switch 150A, and on the basis of this, a travel restriction that prohibits the travel of the vehicle body 2 is executed. This travel regulation is performed by the travel regulation device 210 shown in FIG. Hereinafter, the travel restriction device 210 will be described with reference to FIG.

  The travel restriction device 210 shown in FIG. 11 is configured by a CPU (central processing unit), a control circuit, and the like mounted on a control board installed in the control box 9 (see FIG. 1). The travel restricting device 210 determines whether or not the overturn prevention plate 110 is moving upward based on the detection signal from the limit switch 150A, and determines whether or not the overturn prevention plate 110 is based on the detection signal from the limit switch 150B. It is configured to determine whether or not it is at the storage position. Further, it is configured to determine a tilt state of the vehicle body 2 based on a detection signal from the tilt angle sensor 220. Note that the tilt angle sensor 220 is configured to output a detection signal corresponding to the tilt angle of the vehicle body 2, and is disposed on a control board in the control box 9, for example.

  In addition, the travel restriction device 210 determines that the vehicle body 2 is tilted by a certain degree or more when the aerial work vehicle 1 is running with the extendable mast 6 extended and the worktable 5 moved to a higher position. In such a case, when it is determined that the overturn prevention plate 110 located at the deployed position has moved upward, travel restriction is executed to prohibit the travel of the vehicle body 2 and stop the vehicle body 2. This travel regulation is performed by, for example, stopping power supply to the travel motor or stopping a command signal to the travel motor. Further, when the travel regulation is performed, the travel regulation device 210 causes the display 230 to display characters or symbols indicating that the travel regulation is being performed and the cause thereof, or generates a warning sound by a warning sound generator. 240. The display 230 and the warning sound generator 240 are provided in, for example, the operation device 8 (see FIGS. 1 and 2).

  FIG. 12 shows an example of a travel restriction process performed by the travel restriction device 210. Hereinafter, the details of the travel restriction processing will be described with reference to FIG. In this traveling restriction process, in a state where traveling of the vehicle body 2 is allowed while the work table 5 is moved to a high place (step S1), it is determined whether the overturn prevention plate 110 located at the deployed position has moved upward. It is determined whether or not it is (step S2). This determination is made based on whether a detection signal is output from the limit switch 150A. Here, when it is determined that the fall prevention plate 110 has not moved upward, the state in which traveling is permitted is maintained.

  On the other hand, when it is determined that the fall prevention plate 110 has moved upward, it is determined whether or not the time detected by the limit switch 150A is equal to or longer than a predetermined time (for example, 0.3 seconds) (step S3). This determination is made based on whether the detection signal from the limit switch 150A has been continuously output for a predetermined time or more. Here, when it is determined that the detection time is not equal to or longer than the predetermined time, the state in which traveling is permitted is maintained, and when it is determined that the detection time is equal to or longer than the predetermined time, the inclination angle of the vehicle body 2 is equal to or more than the predetermined angle θ1. It is determined whether or not there is (step S4). This determination is made based on a detection signal from the inclination angle sensor 220. Here, if it is determined that the inclination angle of the vehicle body 2 has not reached the predetermined angle θ1, the state in which traveling is permitted is maintained, and if it is determined that the inclination angle of the vehicle body 2 is equal to or larger than the predetermined angle θ1, The regulation is executed (step S5). When the inclination angle of the vehicle body 2 does not reach the predetermined angle θ1, the predetermined angle θ1 is an angle that does not hinder the traveling even when the vehicle body 2 runs while the work table 5 is moved to a high place. (For example, an arbitrary angle within a range of 0 to 1.5 degrees).

  After the start of the running regulation, it is determined whether or not the overturn prevention plate 110 has been stored (step S6). This determination is made based on whether a detection signal is output from the limit switch 150B. Here, when it is determined that the fall prevention plate 110 is not stored, the travel restriction is continuously executed, and when it is determined that the fall prevention plate 110 is stored, the travel restriction is released (step S7). Since the fall prevention plate 110 is stored when the telescopic mast 6 is retracted and stored and the work table 5 is moved to a low place, the work table 5 is stored when the fall prevention plate 110 is stored. You are moving to a lower place.

  In this traveling restriction process, when the fall prevention plate 110 has moved upward and, at the same time, the inclination angle of the vehicle body 2 has reached the predetermined angle θ1, the traveling restriction is executed and the vehicle body 2 stops. Is done. For this reason, when one of the wheels 3a and 3b enters the concave portion and the vehicle body 2 starts to lean, and the fall prevention plate 110 comes into contact with the ground, the vehicle body 2 is stopped. Therefore, it can be prevented that the vehicle body 2 travels while the overturn prevention plate 110 is in contact with the ground and the wheels further enter the concave portion, and the inclination of the vehicle body 2 becomes large. However, even when the overturn prevention plate 110 is moved upward, if the inclination angle of the vehicle body 2 does not reach the predetermined angle θ1, the travel restriction is not performed. Therefore, for example, the fall prevention plate 110 has moved upward due to an object being sandwiched between the ground and the fall prevention plate 110 during traveling of the vehicle body 2, but the inclination angle of the vehicle body 2 is small, which hinders traveling. In such a case, it is possible to prevent the travel regulation from being executed.

  Also, in this traveling restriction process, if the state in which the fall prevention plate 110 has moved upward does not continue for a predetermined time or more, the traveling restriction is not performed. Therefore, when the fall prevention plate 110 moves upward for a moment due to unevenness of the ground on which the vehicle is traveling, etc., the traveling restriction is executed, and the vehicle body 2 is frequently stopped, which hinders the work. Can be prevented. The travel restriction may be performed only when the overturn prevention plate 110 is moved upward and the state in which the inclination angle of the vehicle body 2 is equal to or more than the predetermined angle θ1 continues for a predetermined time or more. Thus, when the fall prevention plate 110 moves upward for a moment or the vehicle body 2 tilts slightly for a moment, it is possible to prevent the travel regulation from being executed.

  Further, in the travel regulation process, after the travel regulation is performed, the travel regulation is not released until the fall prevention plate 110 is stored (the work table 5 moves to a lower place). For example, even if the power is turned on / off or the inclination angle of the vehicle body 2 becomes smaller than θ1 after the execution of the travel regulation, the travel regulation is not released. In this way, by making the conditions for canceling the travel regulation strict, it is possible to ensure safety after the travel regulation is canceled.

Note that, when the inclination angle of the vehicle body 2 is equal to or larger than another predetermined angle θ2, the travel restriction device 210 performs the travel restriction regardless of whether the fall prevention plate 110 has moved upward. .
When the inclination angle of the vehicle body 2 reaches the predetermined angle θ2, the predetermined angle θ2 is an angle (for example, 2.0 degrees) at which it is considered that running while the work table 5 is moved to a high place is likely to be hindered. Degrees).

  As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above embodiments, and can be appropriately changed. For example, in the above-described embodiment, a long hole (a pivot hole 2e) is provided on the vehicle body 2 side so that the fall prevention plate 110 located at the deployed position can be moved upward, and a shaft member is provided on the fall prevention plate 110 side. Although the (pivot pin 116) is provided, the present invention is not limited to this. For example, a shaft member may be provided on the vehicle body 2 side, and an elongated hole may be provided on the overturn prevention plate 110 side.

  Further, in the above-described embodiment, the overturn prevention plate 110 is configured to be able to move upward in a portion where the pivot portion 112 is provided. However, the present invention is not limited to this. It may be configured to be able to move upward in the portion provided, or in both the portion provided with the pivot portion 111 and the portion provided with the pivot portion 112. The configuration for enabling the overturn prevention plate to move upward is not limited to the combination of the elongated hole and the shaft member. For example, the overturn prevention plate is connected to the vehicle body via a plurality of link members. Thereby, the fall prevention plate located at the deployed position may be configured to be able to move upward.

  In the travel restriction process in the above-described embodiment, if the inclination angle of the vehicle body 2 has not reached the predetermined angle θ1, the travel restriction is not performed even if the overturn prevention plate 110 is moved upward. The present invention is not limited to this, and when it is determined that the fall prevention plate 110 has moved upward, the travel restriction may be performed regardless of whether the inclination angle of the vehicle body 2 has reached the predetermined angle θ1. Good. Even in such a case, the travel restriction is performed when the state in which the fall prevention plate 110 has moved upward continues for a predetermined time or more, but the travel restriction may not be performed when the state does not continue. In addition to the driving regulation, the steering operation may be regulated.

  In the above-described embodiment, the telescopic mast type aerial work vehicle has been described as an aerial work vehicle according to the present invention. However, the aerial work vehicle is not limited thereto. Alternatively, a scissors-link type self-propelled aerial work vehicle or a boom type self-propelled aerial work vehicle may be used.

1 aerial work platform 2 body 2e pivot hole (long hole)
4 Telescopic device 5 Workbench 6 Telescopic mast 8 Operating device 9 Control box 100 Overturn prevention device 110 Overturn prevention plates 111 and 112 Pivoting part 116 Pivoting pin (shaft member)
120 Drive arm 140 Retraction operating parts 150A, 150B Limit switch 210 Travel restriction device

Claims (3)

A vehicle body that can run with front and rear wheels,
An elevating device provided on the vehicle body,
A working device that is raised and lowered by the lifting device,
A lower part of the vehicle body between the front and rear wheels is swingably connected around an axis extending in the front-rear direction, is swung inward and is swung toward a storage position located along a lower surface of the vehicle body and outward and downward. A safety device for an aerial work vehicle having a fall prevention plate that can swing and move to a deployed position where the lower end approaches the ground,
The overturn prevention plate is configured to be movable upward by a predetermined amount with respect to the vehicle body in a state where the overturn prevention plate is located at the deployment position,
Movement detecting means for detecting that the fall prevention plate has moved upward in the deployed position,
A safety device for an aerial work vehicle, comprising: a travel restricting means for restricting the travel of the vehicle body when the upward movement of the fall prevention plate is detected by the movement detection means. The fall prevention plate,
An elongated hole that is provided on one of the vehicle body and the tipping prevention plate, and extends vertically upward and penetrates while the tipping prevention plate is located at the deployed position;
A shaft member that is provided on the other of the vehicle body and the fall prevention plate and that is inserted into the long hole so as to be movable up and down relative to the long hole; The safety device for an aerial work vehicle according to claim 1, wherein the safety device is connected. 3. The vehicle according to claim 1, wherein the traveling restricting unit restricts traveling of the vehicle body when the upward movement of the overturn prevention plate is detected by the movement detecting unit for a predetermined time or more. 4. A safety device for an aerial work vehicle according to item 1.

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