JP7832044B2 - Wheel chock placement indicator device - Google Patents

Description

This invention relates to a wheel chock placement indicator device that indicates the placement of wheel chocks to prevent vehicles such as work vehicles from running away.

In vehicles such as work vehicles, when the vehicle is parked for work, in addition to braking the wheels with the parking brake, a wedge-shaped wheel chock is placed between the wheels and the road surface to prevent the vehicle from running away. Furthermore, for example, Patent Document 1 discloses a work vehicle equipped with wheel chock detection units (e.g., ultrasonic sensors or laser sensors) positioned to look down on the area where the wheels are in contact with the ground (hereinafter also referred to as the "ground contact area") from the bottom of the vehicle body, both in front of and behind the wheels. In this work vehicle, if the wheel chock detection unit does not detect a wheel chock placed on the wheel, the jack-up lamp, which illuminates when the jacking device is in contact with the ground, flashes to inform the worker that no wheel chocks are placed on the wheel.

Japanese Patent Publication No. 2016-141567

Generally, the correct placement of wheel chocks on a work vehicle is considered to be placing chocks both in front of and behind the rear wheels when the vehicle is parked on a flat surface, and placing chocks on the wheels on the downhill side when the vehicle is parked on a ramp. However, determining whether a surface is a ramp can be difficult depending on the angle of the slope and the surrounding landscape. Therefore, there is a risk that workers may unknowingly place wheel chocks on the rear wheels of a work vehicle on a ramp, using the same placement as on a flat surface (i.e., placing them both in front of and behind the rear wheels), resulting in improper wheel chock placement on a ramp.

This invention has been made in view of the above problems, and aims to provide a wheel chock placement indicator that can display the appropriate placement of wheel chocks according to the slope of the road surface where a work vehicle is parked, even in environments where it is difficult to determine whether the road is flat or sloped.

To solve the above problems, the wheel chock placement instruction device according to the present invention is a wheel chock placement instruction device that instructs the placement of wheel chocks on the wheels of a vehicle, and is characterized by comprising: a tilt angle detection device (for example, a tilt angle detector 101 in the embodiment) that detects the tilt angle of the vehicle in the longitudinal direction; a tilt direction determination device (for example, a controller 60 in the embodiment) that determines whether the vehicle is tilted downwards or upwards based on the tilt angle detected by the tilt angle detection device; a storage device (for example, a controller 60 in the embodiment) that stores appropriate placement information indicating whether the wheel chocks should be placed on the front or rear side of the wheels; and a placement display device (for example, a controller 60 and a display device 104 in the embodiment) that reads the appropriate placement information corresponding to the tilt direction of the vehicle determined by the tilt direction determination device from the storage device and displays the placement of the wheel chocks indicated by the read appropriate placement information.

In the wheel chock placement indicator device with the above configuration, the appropriate placement information includes first appropriate placement information indicating that the wheel chock should be placed in front of the wheel, and second appropriate placement information indicating that the wheel chock should be placed behind the wheel. Preferably, the placement display device is configured to display a first display mode indicating that the wheel chock should be placed in front of the wheel by referring to the first appropriate placement information stored in the storage device if the tilt angle of the vehicle detected by the tilt angle detection device is greater than or equal to a predetermined angle and the tilt direction determined by the tilt direction determination device is downward towards the front, and to display a second display mode indicating that the wheel chock should be placed behind the wheel by referring to the second appropriate placement information stored in the storage device if the tilt angle of the vehicle detected by the tilt angle detection device is greater than or equal to a predetermined angle and the tilt direction determined by the tilt direction determination device is upward towards the front.

Furthermore, in the wheel chock placement indicator device with the above configuration, it is preferable that the appropriate placement information includes a third appropriate placement information indicating that the wheel chocks should be placed on both the front and rear sides of the wheels, and that the placement display device is configured such that, when the tilt angle of the vehicle is less than a predetermined angle, the appropriate placement information read from the storage device is the third appropriate placement information, and the device displays a third display mode indicating that the wheel chocks should be placed on both the front and rear sides of the wheels.

Furthermore, it is preferable that the wheel chock placement indicator device with the above configuration includes a detection device for detecting the wheel chocks positioned in front of and behind the front and rear wheels of the vehicle, and an alarm device that activates an alarm if the detection device does not detect the wheel chocks in the arrangement corresponding to the display pattern shown on the placement display device.

The wheel chock placement indicator according to the present invention comprises: a tilt angle detection device that detects the tilt angle of the vehicle in the longitudinal direction; a tilt direction determination device that determines whether the vehicle is tilted downwards or upwards based on the tilt angle detected by the tilt angle detection device; a storage device that stores appropriate placement information indicating whether the wheel chock should be placed in front of or behind the wheels; and a placement display device that reads the appropriate placement information corresponding to the vehicle's tilt direction determined by the tilt direction determination device from the storage device and displays the placement of the wheel chock indicated by the read appropriate placement information. With this configuration, the placement display device displays whether the wheel chock should be placed in front of or behind the wheels according to the vehicle's tilt direction. Therefore, even on gently sloping surfaces where it is difficult for an operator to determine whether the road surface is flat or sloped just by looking at it, the operator can reliably prevent the vehicle from running away by placing the wheel chock according to the displayed placement.

Furthermore, in the wheel chock placement indicator device with the above configuration, the appropriate placement information includes a first appropriate placement information indicating that the wheel chock should be placed in front of the wheels, and a second appropriate placement information indicating that the wheel chock should be placed behind the wheels. The placement display device preferably displays a first display mode indicating that the wheel chock should be placed in front of the wheels by referring to the first appropriate placement information stored in the storage device if the vehicle's tilt angle detected by the tilt angle detection device is greater than or equal to a predetermined angle, and the tilt direction determined by the tilt direction determination device is downward towards the front. If the vehicle's tilt angle detected by the tilt angle detection device is greater than or equal to a predetermined angle, and the tilt direction determined by the tilt direction determination device is upward towards the front, it preferably displays a second display mode indicating that the wheel chock should be placed behind the wheels by referring to the second appropriate placement information stored in the storage device. With this configuration, even on a slight incline where it is difficult for the operator to determine the vehicle's tilt direction simply by looking at the road surface, the vehicle can be reliably prevented from running away by placing the wheel chock according to the displayed arrangement.

Furthermore, in the wheel chock placement indicator device with the above configuration, the appropriate placement information includes a third appropriate placement information indicating that wheel chocks should be placed both in front of and behind the wheels. Preferably, the placement display device, when the tilt angle detection device detects that the vehicle's tilt angle is less than a predetermined angle, displays a third display mode indicating that wheel chocks should be placed both in front of and behind the wheels if the appropriate placement information read from the storage device is the third appropriate placement information. With this configuration, even when the vehicle is parked on a flat road, it is displayed that wheel chocks should be placed both in front of and behind the wheels. This prompts the operator to place wheel chocks even on a flat road, thereby more reliably preventing the vehicle from running away.

Furthermore, it is preferable that the wheel chock placement indicator device with the above configuration includes a detection device that detects wheel chocks placed in front of and behind the front and rear wheels of the vehicle, and an alarm device that activates an alarm if the detection device does not detect wheel chocks in the arrangement corresponding to the display pattern shown on the placement display device. With this configuration, if an operator misses the display regarding the placement of the wheel chocks, they will be notified that the wheel chocks are not properly placed. This helps to raise awareness among operators that the wheel chocks should be properly placed, thereby reducing the risk of the vehicle running away.

This is a side view of an aerial work platform equipped with a wheel chock placement indicator according to this embodiment. This is a functional block diagram including a wheel chock placement indicator device according to this embodiment. This is a perspective view showing the wheel chocks, which are the target of the wheel chock placement instruction device of this embodiment, installed in front of and behind the tire wheels. This is a side view of the above wheel chock device. This is a perspective view of the above-mentioned wheel chock device with the handle in the first reference position. This is a perspective view of the above-mentioned wheel chock device with the handle in the second reference position. This is a plan view of the wheel chock device with the handle in the first reference position. This is a perspective view of the wheel chock member of the wheel chock device described above. This is a cross-sectional view of the locking mechanism (index plunger) of the above-mentioned wheel chock device. This is a rear view illustrating the oscillation of the handle described above. This is an explanatory diagram illustrating the relationship between the detection by the wheel chock device and the extension operation of the jack device. This is an explanatory diagram illustrating the method for calculating the distance from the detection device to the wheel chock and the detection direction when the jack device extends in the width direction of the vehicle body by the outrigger device in the detection of the wheel chock described above. This is an explanatory diagram illustrating the method for detecting the wheel chock when the jacking device extends in the width direction of the vehicle body due to the outrigger device. This is an explanatory diagram illustrating the method for detecting the wheel chock when the jacking device extends in the width direction of the vehicle body due to the outrigger device. This is an explanatory diagram illustrating the display format used to indicate the arrangement of wheel chocks according to the vehicle body's tilt angle in the wheel chock placement indicator device according to this embodiment. This is an explanatory diagram for describing the display format used to indicate the placement of wheel chocks according to the vehicle body's tilt angle in the wheel chock placement indicator device described above.

The following describes preferred embodiments of the present invention with reference to the drawings. Figure 1 shows an aerial work platform 1 equipped with a wheel chock placement indicator device according to this embodiment, and the overall configuration of the aerial work platform 1 will be described with reference to this figure. In the description with reference to Figure 1, when referring to the front-rear direction, the direction of the arrows shown in Figure 1 will be followed.

As shown in Figure 1, the aerial work platform 1 is based on a truck vehicle that has a driver's cabin 7 at the front of the vehicle body 2 and is propelled by a pair of left and right tires 5 arranged at the front and rear of the vehicle body 2. The vehicle body 2 is composed of a vehicle frame consisting of a chassis frame on which four tires 5 (left front wheel, left rear wheel, right front wheel, and right rear wheel) are arranged, and a subframe mounted on this chassis frame. The tires 5 shown in Figure 1 are the left front wheel 5Lf and the left rear wheel 5Lr, and although not shown in Figure 1, the right front wheel 5Rf and the right rear wheel 5Rr are provided on the right side of the vehicle body 2. In addition, mudguards 8f for the front wheels are provided behind the left front wheel 5Lf and the right front wheel 5Rf, and mudguards 8r for the rear wheels are provided behind the left rear wheel 5Lr and the right rear wheel 5Rr.

The vehicle body 2 is equipped with jacking devices 10 on its front, rear, left, and right sides to lift and support the vehicle body 2 during work at height. The jacking device 10 consists of a left front jack 10Lf located behind the left front wheel 5Lf, a left rear jack 10Lr located behind the left rear wheel 5Lr, a right front jack 10Rf (not shown) located behind the right front wheel 5Rf, and a right rear jack 10Rr located behind the right rear wheel 5Rr (see Figure 12). Each jacking device 10 extends downwards by driving a jack cylinder 11 located inside it, thereby grounding the jack base 10B located at the tip of the jacking device 10. Further extension of the jack cylinder 11 from this position lifts and supports the vehicle body 2, stabilizing the entire vehicle.

Each jacking device 10 is equipped with an outrigger device 12 (see Figure 12) corresponding to that device. Here, the outrigger device 12 corresponding to the left front jack 10Lf is called the left front outrigger 12Lf, and the outrigger device 12 corresponding to the left rear jack 10Lr is called the left rear outrigger 12Lr. Similarly, the outrigger device 12 corresponding to the right front jack 10Rf is called the right front outrigger 12Rf, and the outrigger device 12 corresponding to the right rear jack 10Lr is called the right rear outrigger 12Rr.

Each outrigger device 12 is equipped with an outrigger cylinder 13 (see Figure 2). By extending or retracting the outrigger cylinder 13, the corresponding jack device 10 is moved horizontally in the width direction of the vehicle body 2 (from front to back/back to front in Figure 1). Specifically, extending the outrigger cylinder 13 moves the jack device 10 outwards from the side of the vehicle body 2. Conversely, retracting the extended outrigger cylinder 13 moves the jack device 10, which has been protruding from the side of the vehicle body 2, back into the vehicle body 2. The rear end of the vehicle body 2 is equipped with a lower operating device 27 for operating each jack device 10, the outrigger devices 12, and the boom 30, which will be described later.

A slewing platform 20, driven by a slewing motor 24 and configured to rotate horizontally around its vertical axis, is provided on the frame located behind the driver's cabin 7 on the vehicle body 2. The base end of a boom 30 is attached to a support column 21 extending upward from the slewing platform 20 via a foot pin 22, allowing it to swing (raise and lower) vertically. Furthermore, toolboxes 26 for storing work tools and equipment are provided on the left and right sides of the frame on the vehicle body 2.

The boom 30 has a structure in which the base boom 30a, intermediate boom 30b, and tip boom 30c are nested together in order from the turntable 20 side. The boom 30 can be extended and retracted axially (longitudinal direction) by the extension and retraction drive of the telescopic cylinder 31 located inside. Furthermore, a luffing cylinder 23 is mounted between the base boom 30a and the support column 21, and by extending and retracting this luffing cylinder 23, the entire boom 30 can be raised and lowered within the vertical plane.

A vertical post 32 is pivotally supported at the tip of the tip boom 30c so as to be able to swing up and down. This vertical post 32 is controlled to swing (level) so as to be kept in a vertical position at all times, regardless of the elevation angle of the boom 30, by an upper leveling cylinder (not shown) straddling the tip of the tip boom 30c and a lower leveling cylinder 25 straddling the base boom 30a and the support column 21. A work platform 40 for worker use is attached to this vertical post 32 via a work platform bracket (not shown). A swivel motor 34 is provided inside this work platform bracket, and by driving this swivel motor 34, the entire work platform 40 can be moved swivel (horizontally rotated) around the vertical post 32 as an axis. Here, as described above, the vertical post 32 is kept in a vertical position at all times, and as a result, the floor surface of the work platform 40 is kept horizontal at all times, regardless of the elevation angle of the boom 30.

The work platform 40 is equipped with an upper control device 45 that includes various operating means such as operating levers, switches, and dials for operation by the worker on the platform. Therefore, the worker on the work platform 40 can operate the upper control device 45 to perform various operations, including the rotation of the turntable 20 (rotation of the turntable motor 24), the luffing of the boom 30 (extension and retraction of the luffing cylinder 23), the extension and retraction of the boom 30 (extension and retraction of the extension cylinder 31), and the swivel operation of the work platform 40 (rotation of the swivel motor 34).

Generally, when an aerial work platform is operating at a work site, before operating the jacks 10Lf, 10Rf, 10Lr, and 10Rr after parking, the parking brake is first applied to brake the left and right rear wheels 5Lr and 5Rr. Then, wheel chocks are installed between the road surface and the tread surface of the tire wheels 5 to prevent the vehicle from running away. Therefore, the aerial work platform 1 shown in Figure 1 is equipped with a wheel chock detector 100 (see Figure 2) to determine whether the wheel chocks are correctly positioned relative to the tire wheels 5.

While the wheel chock detector 100 can utilize sensors capable of non-contact detection of the presence or absence of an object (e.g., photoelectric sensors, ultrasonic sensors, laser sensors, etc.), this embodiment uses a camera as the wheel chock detector 100. Based on the image signal output from the wheel chock detector 100, the controller 60 (see Figure 2), described later, performs known image processing to determine the presence or absence of the wheel chock device. Therefore, in this embodiment, the image acquired by the wheel chock detector 100 and the image processing performed by the controller 60 constitute a so-called image discrimination sensor.

The wheel chock detector 100 installed on the vehicle body 2 includes, as shown in Figure 1, a left front wheel chock detector 110L fixed to the bottom of the driver's cabin 7 for detecting the wheel chock device located in front of the left front wheel 5Lf; a left rear wheel chock detector 111L fixed to the jack base 10B of the left front jack 10Lf with its detection direction (hereinafter also referred to as "detection direction") facing the rear of the left front wheel 5Lf; a left front wheel chock detector 112L fixed to the jack base 10B of the left front jack 10Lf with its detection direction facing the front of the left rear wheel 5Lr; and a left rear wheel chock detector 113L fixed to the jack base 10B of the left rear jack 10Lr with its detection direction facing the rear of the left rear wheel 5Lr.

Furthermore, although not shown in Figure 1, on the right side of the vehicle body 2, there are similarly: a right front wheel chock detector 110R fixed to the bottom of the driver's cabin 7 and positioned in front of the right front wheel chock 70; a right rear wheel chock detector 111R fixed to the jack base 10B of the right front jack 10Rf with its detection direction facing the rear of the right front wheel 5Rf; a right front wheel chock detector 112R fixed to the jack base 10B of the right front jack 10Rf with its detection direction facing the front of the right rear wheel 5Rr; and a right rear wheel chock detector 113R fixed to the jack base 10B of the right rear jack 10Rr with its detection direction facing the rear of the right rear wheel 5Rr (see Figure 2).

Next, referring to Figure 2, we will describe the configuration for controlling the operation of each hydraulic actuator, including the jack cylinder 11, outrigger cylinder 13, slewing motor 24, luffing cylinder 23, telescopic cylinder 31, and swivel motor 34, and for detecting the wheel chocks, based on the operation signals output by the operation of the upper operating device 45 or lower operating device 27 described above.

As shown in Figure 2, the aerial work platform 1 includes a hydraulic unit 50 that supplies hydraulic fluid to operate the aforementioned hydraulic actuators, and a controller 60 that receives operation signals from the upper operating device 45 and the lower operating device 27 and controls the operation of each hydraulic actuator. The hydraulic unit 50 comprises a hydraulic pump 51 that discharges hydraulic fluid, a pump drive motor 52 that drives the hydraulic pump 51, and a control valve 53 that controls the supply direction and amount of hydraulic fluid supplied from the hydraulic pump 51 to each hydraulic actuator.

The pump drive motor 52 is rotationally driven by power supplied from the mounting unit battery 59 via the inverter 54, thereby operating the hydraulic pump 51 and discharging hydraulic fluid to the control valve 53. The control valve 53 includes an electromagnetic proportional control valve V1 corresponding to the jack cylinder 11, an electromagnetic proportional control valve V2 corresponding to the outrigger cylinder 13, an electromagnetic proportional control valve V3 corresponding to the slewing motor 24, an electromagnetic proportional control valve V4 corresponding to the luffing cylinder 23, an electromagnetic proportional control valve V5 corresponding to the telescopic cylinder 31, and an electromagnetic proportional control valve V6 corresponding to the swivel motor 34.

When an operation signal output by the upper operating device 45 or the lower operating device 27 is input to the controller 60, the operation control unit 61 of the controller 60 outputs a command signal corresponding to that operation signal to the control valve 53. Based on the command signal from the operation control unit 61 of the controller 60, the control valve 53 electromagnetically drives the spools of each electromagnetic proportional control valve V1 to V6 to control the supply direction and amount of hydraulic fluid supplied from the hydraulic pump 51 to each hydraulic actuator, thereby controlling the operating direction and operating speed of each hydraulic actuator. As a result, the upper operating device 45 or the lower operating device 27 can perform operations such as the extension and retraction of the jack device 10 and outrigger device 12, the rotation of the turntable 20, the luffing and raising of the boom 30, the extension and retraction of the boom 30, and the swiveling of the work platform 40.

The aerial work platform 1 is configured to determine whether or not wheel chocks are in place, and in addition to the aforementioned wheel chock detectors 100 (left front wheel chock detector 110L, left front wheel rear wheel chock detector 111L, left rear wheel front wheel chock detector 112L, left rear wheel rear wheel chock detector 113L, right front wheel chock detector 110R, right front wheel rear wheel chock detector 111R, right rear wheel front wheel chock detector 112R, and right rear wheel rear wheel chock detector 113R), it is also equipped with a tilt angle detector 101, an extension amount detector 102, an alarm device 103, and a display device 104.

The tilt angle detector 101 detects the tilt angle of the vehicle body 2 relative to the horizontal plane (the tilt angle of the vehicle body 2 in the longitudinal direction). Here, for example, when the vehicle body 2 is tilted forward (nozzle raised), the tilt angle is detected as a positive angle, and when the vehicle body 2 is tilted backward (nozzle lowered), the tilt angle is detected as a negative angle. The detection signal is then output to the controller 60.

The extension amount detector 102 detects the extension amount of each jack device 10 (left front jack 10Lf, left rear jack 10Lr, right front jack 10Rf, and right rear jack 10Rr) and each outrigger device 12 provided in conjunction with each jack device 10. More specifically, it detects whether each jack device 10 has reached a predetermined extension amount, and detects the extended length of each outrigger device 12, outputting these detection signals to the controller 60.

Here, as a method for detecting whether the extension amount of the jack device 10 has reached a predetermined extension amount, for example, a limit switch that turns on when the jack base 10B touches the ground may be used, or the extension amount of the jack device 10 may be measured, and a signal indicating that the predetermined extension amount has been reached may be output when the measured value indicates that the jack base 10B has descended to a position at least lower than the position of the front wheel mudguard 8f or the rear wheel mudguard 8r. In this case, the measured value of the extension amount of the jack device 10 may be output from the extension amount detector 102 to the controller 60, and the controller 60 may determine whether the predetermined extension amount has been reached based on this measured value. Furthermore, if the aerial work platform 1 is equipped with a safety device (interlock) that disables the operation of the slewing platform 20 and boom 30 while the jack device 10 is not touching the ground, the signal indicating that the jack device 10 has touched the ground used in this safety device may be utilized.

The alarm device 103 generates visual and audible warnings to the worker, such as alarm lamps and alarm buzzers. The display device 104 indicates whether the wheel chocks should be placed in front of or behind the tires 5, depending on the direction of the vehicle body 2's tilt (whether the vehicle body 2 is tilted upwards or downwards). The display content of the display device 104 will be explained in detail later.

As shown in Figure 2, the controller 60 is configured to determine whether a wheel chock is appropriately positioned relative to the tire wheel 5, and includes a predetermined position identification unit 62, a position determination unit 63, and an alarm control unit 64. The predetermined position identification unit 62 calculates the direction and distance at which the wheel chock should be detected by the wheel chock detector 100, which is fixed to the jack base 10B of the jack device 10 that extends from the vehicle body 2, based on the extension amount of the outrigger device 12 output from the extension amount detector 102 when the jack device 10 moves in the direction extending from the vehicle body by the outrigger device 12.

When the extension amount detector 102 detects that the jack device 10 has extended to a predetermined extension amount, the placement determination unit 63 detects the presence or absence of the wheel chock in the appropriate area (described later) identified by the predetermined position identification unit 62 based on the image signal from the wheel chock detector 100, and determines whether the wheel chock is positioned correctly based on this detection result. If the placement determination unit 63 determines that the wheel chock is not properly positioned, the alarm control unit 64 activates an alarm on the alarm device 103. This alarm activation also includes actions that restrict the operation of work equipment (e.g., the jack device 10, outrigger device 12, boom 30, work platform 40, etc.).

Next, the structure of the wheel chock device, which is the target of the placement instructions in this embodiment, will be described with reference to Figures 3 to 10. For the sake of explanation, in the following, the length direction (insertion direction) of the wheel chock device 70 shown in Figures 3 to 10 will be defined as the "front-to-back direction," the width direction as the "left-to-right direction," and the height direction as the "up-and-down direction." However, this does not specify the placement direction of the wheel chock device 70.

The wheel chock device 70 mainly consists of a wheel chock member 71 inserted between the tread surface 5t of the tire wheel 5 and the parking surface G (see Figure 4), and a movable handle 90 provided on this wheel chock member 71.

The wheel chock member 71 is formed in a wedge shape using, for example, a synthetic resin material (plastic material). This wheel chock member 71 has a ground contact portion 72 that forms the bottom that contacts the parking surface, a wheel contact portion 73 that contacts the tire wheel 5, a top portion 74 that forms the uppermost part, a back portion 75 that connects the ground contact portion 72 and the top portion 74, and a pair of side portions 76. Hereinafter, as shown in Figure 4, the side of the wheel chock device 70 (wheel chock member 71) that is inserted between the tread surface 5t of the tire wheel 5 and the parking surface G (left side in the figure) will be referred to as the "tip side," and the opposite side (right side in the figure) will be referred to as the "base end side."

The contact area 72 has a non-slip surface 72a formed by a continuous arrangement of peaks and valleys along the front-rear direction, providing anti-slip properties against the ground. The wheel contact area 73 is formed as a curved surface that rises from the front end towards the base end and concaves diagonally upward, allowing it to contact the tread surface 5t of the tire wheel 5. This wheel contact area 73 may be partially or entirely formed as an inclined surface. A T-shaped handle 77, for gripping when carrying the wheel chock device 70, protrudes from the lower part of the rear section 75. Furthermore, a vertical plate-shaped bracket 80 for supporting the handle 90 protrudes from the upper part of the rear section 75.

As shown in Figure 8, the bracket portion 80 is provided with a hollow cylindrical boss portion 81, a pair of stopper portions (first stopper portion 82, second stopper portion 83) formed diagonally below and to the left and right of the boss portion 81, and a pair of positioning holes (first positioning hole 84, second positioning hole 85) formed on the left and right sides of the boss portion 81.

The boss portion 81 is formed in a cylindrical shape extending in the front-rear direction, with a through-hole 81a formed through its center. The bolt shaft portion 86a of the bolt 86, which serves as the pivot axis of the handle 90, is inserted through this through-hole 81a. A nut (locking nut) 87 is screwed onto the tip of the bolt shaft portion 86a to prevent it from coming loose from the through-hole 81a. The stopper portions 82 and 83 are formed in a rectangular prism shape extending in the front-rear direction, with a seating surface formed on their upper side for contact with the handle 90. The positioning holes 84 and 85 are through-holes extending through the front and back of the bracket portion 80, and are configured to allow engagement (insertion) of the lock pin 93b described later.

The handle 90 comprises an L-shaped handle arm 91 pivotally connected to the bracket portion 80 via a bolt shaft portion 86a, and a grip 98 fixed to the handle arm 91. The handle arm 91 is integrally formed using a synthetic resin material. This handle arm 91 has an arm base portion 92 extending in the left-right direction, and a guide portion 95 that bends almost vertically from the end of the arm base portion 92 and extends in the front-rear direction, and is formed in an L-shape overall. A connecting hole 92a (see Figure 9) is formed in the arm base portion 92 that penetrates in the front-rear direction, and the bolt shaft portion 86a is inserted through this connecting hole 92a. The entire handle 90 is pivotally connected to the bracket portion 80 so as to swing freely, with the bolt shaft portion 86a inserted through the connecting hole 92a of the arm base portion 92 as the pivot axis. Furthermore, a screw hole 92b (see Figure 9) is formed approximately in the center of the arm base portion 92, extending in the front-to-back direction. An index plunger 93 for fixing the position of the handle 90 is screwed into this screw hole 92b.

The index plunger 93 is a known mechanical element and comprises a body 93a screwed onto the arm base 92, a lock pin 93b slidably mounted on the body 93a and capable of engaging with the positioning holes 84 and 85, and a knob 93c provided at the base end of the lock pin 93b for operating the lock pin 93b. The lock pin 93b is constantly biased by a spring (not shown) built into the body 93a in a direction that protrudes from the body 93a (in the direction that engages with the positioning holes 84 and 85). The lock pin 93b is configured to move back and forth between a retracted position in which the tip of the lock pin 93b is pulled into the body 93a by pulling the knob 93c against the biasing force of the spring, and a locked position in which the tip of the lock pin 93b is pushed out from the body 93a by the biasing force of the spring by releasing the knob 93c. As a result, the lock pin 93b is positioned in the bracket 8
The stopper portions 82, 83 and positioning holes 84, 85 provided at 0 work together to position the handle 90 and restrict the range in which the handle 90 can swing.

The guide portion 95 is formed in a flat plate shape extending in a direction parallel to the insertion direction of the wheel chock member 71 (the front-rear direction). The inner surface 95a of this guide portion 95 is formed to abut against the outer surface 5a of the tire wheel 5 (the outer side of the left and right sides), and functions as a positioning part in the width direction when installing the wheel chock device 70 on the tire wheel 5 (details described later). The grip 98 is the part that the worker grasps when the handle 90 is swung, or when transporting, installing, and removing the wheel chock device 70. One end of the grip 98 is fixed to the arm base portion 92, and the other end of the grip 98 is fixed to the guide portion 95. A gap 99 (see Figure 7) is formed between the grip 98 and the handle arm 91, allowing fingers to be inserted when gripping the grip 98.

The handle 90, in this configuration, is configured to swing freely between a first reference position (see Figure 5) where the arm base portion 92 abuts against the upper surface of the first stopper portion 82 and the guide portion 95 is positioned on one side in the width direction of the wheel chock member 71, and a second reference position (see Figure 6) where the arm base portion 92 abuts against the upper surface of the second stopper portion 83 and the guide portion 95 is positioned on the other side in the width direction of the wheel chock member 71, using the bolt shaft portion 86a provided on the bracket portion 80 as the pivot axis. When the handle 90 swings to the first reference position, the lock pin 93b of the index plunger 93 and the first positioning hole 84 are aligned, and the handle 90 is fixed to the first reference position by operating the knob 93c to engage the lock pin 93b with the first positioning hole 84. When the handle 90 swings to the second reference position, the lock pin 93b of the index plunger 93 aligns with the second positioning hole 85. By operating the knob 93c to engage the lock pin 93b with the second positioning hole 85, the handle 90 is fixed to the second reference position. In this way, by swinging the handle 90 to either the first or second reference position and fixing it with the index plunger 93, the handle 90 can be selectively positioned between the first and second reference positions.

Here, when the handle 90 is in the first or second reference position, the inner surface 95a of the guide portion 95 is held parallel to the side portion 76 of the wheel chock member 71 (opposing each other in the left-right direction), and the distance from the center position in the width direction of the wheel chock member 71 to the inner surface 95a of the guide portion 95 in a plan view is configured to be approximately equal to half the width of the tire wheel 5 (see Figure 7). Therefore, when the handle 90 is swung to the first or second reference position, and the inner surface 95a of the guide portion 95 comes into contact with the outer surface 5a of the tire wheel 5 (when the position of the inner surface 95a of the guide portion 95 and the position of the outer surface 5a of the tire wheel 5 coincide), the center in the width direction of the wheel chock member 71 coincides with the center in the width direction of the tire wheel 5, resulting in an appropriate positional relationship (the wheel chock member 71 is positioned at the center in the width direction of the tire wheel 5). Note that at this time, the handle 90 extends outward beyond the side of the vehicle body 2.

Next, the procedure for positioning the wheel chock device 70 will be described. First, the handle 90 of the wheel chock device 70 is swung to fix the handle 90 to a swing position (first reference position or second reference position) corresponding to the arrangement position (orientation of the outer surface 5a) of the target tire wheel 5. Specifically, the handle 90 is selectively swung to the first reference position or the second reference position so that the guide portion 95 of the handle 90 is on the outer surface 5a side of the tire wheel 5 (the left side for left tire wheels 5Lf, 5Lr, and the right side for right tire wheels 5Rf, 5Rr). After swinging the handle 90 to the first reference position or the second reference position, the handle 90 is fixed to that swing position by operating the knob 93c of the index plunger 93 to engage the lock pin 93b with the corresponding positioning holes 84, 85. By selectively switching the swing position of the handle 90 (first reference position, second reference position) according to the orientation of the outer surface 5a of the target tire wheel 5, the installation of the wheel chock device 70 can be easily performed from the outside of the tire wheel 5 (on the left and right sides of the vehicle body 2) without having to crawl under the vehicle body 2.

Next, the wheel chock device 70 is positioned near the target tire wheel 5 (on the parking surface), and the tip of the wheel chock member 71 is directed toward the tread surface 5t of the tire wheel 5. Then, the grip 98 of the wheel chock device 70 is grasped, and the inner surface 95a of the guide portion 95 is brought into contact with the outer surface 5a of the tire wheel 5. Then, while keeping the guide portion 95 in contact (sliding) with the outer surface 5a of the tire wheel 5, the wheel chock member 71 is inserted between the tread surface 5t of the tire wheel 5 and the parking surface. As a result, the entire wheel chock device 70 is guided along the outer surface 5a of the tire wheel 5 (the contact surface between the guide portion 95 and the tire wheel 5), and with the widthwise center position of the wheel chock member 71 and the widthwise center position of the tire wheel 5 coinciding, the wheel chock member 71 moves parallel to the outer surface 5a of the tire wheel 5 without tilting from side to side, and the wheel contact portion 73 comes into contact with the tread surface 5t of the tire wheel 5. In this manner, with the guide portion 95 of the handle 90 in contact with the outer surface 5a of the tire wheel 5, the wheel contact portion 73 of the wheel chock member 71 contacts the tread surface 5t of the tire wheel 5, thereby positioning the wheel chock device 70 at the correct position relative to the tire wheel 5 (the center of the tire wheel 5 in the width direction). At this time, the handle 90 extends outward beyond the side of the vehicle body 2.

Furthermore, when using a photoelectric sensor or laser sensor as the wheel chock detector 100 shown in Figures 1 and 2, a light reflective member may be attached to the object to be detected 96 formed on the tip side of the guide portion 95, for example, as shown in Figures 3 to 7. This allows the presence or absence of the wheel chock device 70 to be detected by reflecting the light emitted from the light-emitting element of the photoelectric sensor or laser sensor with the reflective member attached to the object to be detected 96, and receiving the reflected light with the light-receiving element of the photoelectric sensor or laser sensor.

Next, we will describe some of the most distinctive configurations among those mentioned above.
<Detection and control of wheel chocks>
(Detection of the wheel chock device according to the extension amount of the jack device)
In the above-described configuration, the detection of the wheel chocks occurs when the extension of the jacking device 10 reaches a predetermined amount while the aerial work platform 1 is parked. This allows the system to detect the wheel chocks 70 and determine whether the wheel chocks 70 are properly positioned relative to the tire wheels 5. The detection of the wheel chocks 70 according to the extension of the jacking device 10 will be explained below with reference to Figure 11. In the following explanation, the operation of the tire wheels 5 (left front wheel 5Lf and left rear wheel 5Lr) located on the left side of the vehicle body 2 and the jacking device 10 (left front jack 10Lf and left rear jack 10Lr) will be described, but the operation will be similar for the tire wheels 5 (right front wheel 5Rf and right rear wheel 5Rr) located on the right side of the vehicle body 2 and the jacking device 10 (right front jack 10Rf and right rear jack 10Rr). Furthermore, in Figure 11, the aerial work platform 1 omits the illustration of the support columns 21, toolbox 26, boom 30, work platform 40, and other components installed on the frame.

First, Figure 11(A) shows the aerial work platform 1 parked, with wheel chocks 70 positioned on both the front and rear sides of the left front wheel 5Lf, and also on both the front and rear sides of the left rear wheel 5Lr. Here, both the left front jack 10Lf and the left rear jack 10Lr are retracted, and since the jack bases 10B of each jack device 10 are not touching the ground, the wheel chock detectors 100 (left front wheel chock detector 110L, left front wheel chock detector 111L, left rear wheel chock detector 112L, and left rear wheel chock detector 113L) are not detecting anything.

Next, the operator operates the lower operating device 27 shown in Figure 1 to extend each jack device 10, and when the jack base 10B of each jack device 10 touches the ground, as shown in Figure 11(B), this is detected by the extension amount detector 102 shown in Figure 2. This causes the controller 60 to activate each wheel chock detector 100 and acquire an image of the corresponding tire wheel 5. The placement determination unit 63 then performs appropriate image processing on the image signals output from each wheel chock detector 100 to determine whether or not the wheel chock devices 70 are in place.

Furthermore, even after the jack base 10B has touched the ground, as shown in Figure 11(C), when each jack device is further extended to lift and support the vehicle body 2, images of the corresponding tires 5 are continuously acquired from each wheel chock detector 100 as long as the jack base 10B is in contact with the ground. This configuration allows for detection of the wheel chocks not only when the vehicle body 2 is lifted and supported, but also when the vehicle body 2 is lowered to the ground from a lifted and supported state.

Thus, since the wheel chock detector 100 detects the wheel chock device 70 based on the image signal from the wheel chock detector 100 when its position has lowered to a position at least lower than the positions of the front wheel fender 8f and rear wheel fender 8r, the detection of the wheel chock device 70 by the wheel chock detector 100 is not obstructed by structures such as the front wheel fender 8f and rear wheel fender 8r shown in Figure 1. Furthermore, since the wheel chock detector 100 does not detect the wheel chock device 70 unless its position has lowered to a position at least lower than the positions of the front wheel fender 8f and rear wheel fender 8r, the risk of misidentifying the front wheel fender 8f and rear wheel fender 8r as the wheel chock device 70 is reduced.

In the embodiment described above, the wheel chock detector 100 was fixed to the jack base 10B. However, this is not the only option. For example, a separate lifting device may be provided to lower the wheel chock detector 100 to a position lower than at least the front wheel mudguard 8f and rear wheel mudguard 8r as the jack device 10 descends.

(Adjustment of detection direction according to the extension amount of the outrigger device)
As mentioned above, since the wheel chock detector 100 is fixed to the jack base 10B located at the tip of the jacking device 10, when the outrigger device 12 is extended and the jacking device 10 extends in the width direction of the vehicle body 2, the positional relationship between the wheel chock detector 100 and the tire wheel 5 changes. For this reason, the controller 60 adjusts the direction in which it detects the wheel chock device 70 positioned relative to the tire wheel 5 (hereinafter referred to as the "detection direction") according to the amount of extension of the outrigger device 12.

The following explanation describes the adjustment of the detection direction according to the extension amount of the outrigger device 12, with reference to Figures 12 to 14. In Figures 12 to 14, parts identical to those shown in Figures 1 and 2 are denoted by the same reference numerals, and detailed explanations are omitted. Furthermore, the following explanation describes the adjustment of the detection direction when the right rear outrigger 12Rr is extended; however, the same adjustments should be made when the left front outrigger 12Lf, left rear outrigger 12Lr, and right front outrigger 12Rf are extended.

Figure 12 is a schematic plan view showing the rear portion of the vehicle body 2. In this figure, an appropriate region pr (indicated by hatched lines in Figure 12) is predetermined for each of the left rear wheel 5Lr and the right rear wheel 5Rr. This appropriate region pr is the region in which the wheel chock device 70 can be considered to be positioned in the appropriate location relative to the tire wheel 5. Furthermore, when the left rear outrigger 12Lr is most retracted, the center point of the detection surface (for example, the lens surface of a camera) of the left rear wheel chock detector 113L is defined as lp. The detection point dp is a point appropriately determined within the appropriate region pr on a line extending from the center point lp in a direction parallel to the longitudinal direction of the vehicle body 2. In this case, the distance between the center point lp and the detection point dp is do. Furthermore, the positional relationship between the center point lp of the right rear wheel stop detector 113R when the right rear outrigger 12Rr is most contracted and the detection point dp, which is appropriately determined in the appropriate region pr on the right rear wheel 5Rr side, is the same.

Under the above premise, suppose, for example, that the right rear outrigger 12Rr is extended and the amount of extension becomes dot. In this case, the distance d _d between the detection point dp and the center point lp (hereinafter referred to as "detection distance d _d ") can be calculated by the following equation (1).
d _d =√(do ² + dot ² )...(1)

Furthermore, the angle θ formed by the line connecting the detection point dp and the center point lp with respect to a line extending parallel to the longitudinal direction of the vehicle body 2 starting from the center point lp (hereinafter referred to as "detection angle θ") can be calculated by the following equation (2).
θ=tan ^-1 (dot/do)...(2)

Therefore, the predetermined position identification unit 62 calculates the detection distance d _d and detection angle θ using equations (1) and (2) above, based on the detection signal indicating the extension amount dot of the outrigger device 12 output from the extension amount detection unit 102. The controller 60 also adjusts the detection direction and detection distance of the wheel chock device 70 by the wheel chock detector 100 based on the detection distance d _d and detection angle θ calculated by the predetermined position identification unit 62.

For example, if a detector with a narrow detection range (e.g., a camera with a narrow field of view) is used as the wheel chock detector 100, as shown in Figure 13, multiple detectors with different detection directions are attached to the jack base 10B, and the detector used is switched according to the extension amount of the outrigger device 12. That is, as shown in Figure 13(A), a wheel chock detector 113Ra for when the right rear outrigger 12Rr is most retracted is provided on the jack base 10B, with its detection direction facing the appropriate area pr of the right rear wheel 5Rr. As shown in Figure 13(B), a wheel chock detector 113Rb for when the right rear outrigger 12Rr is most extended is provided on the jack base 10B, with its detection direction facing the appropriate area pr of the right rear wheel 5Rr. Then, the wheel chock detector 113Ra for when the right rear outrigger 12Rr is extended is switched between using the wheel chock detector 113Ra and the wheel chock detector 113Rb for when the right rear outrigger 12Rr is extended.

Furthermore, when a detector with a wide detection range (for example, LiDAR) is used as the wheel chock detector 100, as shown in Figure 14, an appropriate region pr within the detection range DR is identified based on the detection distance d _d and detection angle θ described above, and it is determined whether or not the wheel chock device 70 is located within the identified appropriate region pr. That is, when the right rear outrigger 12Rr is most retracted, as shown in Figure 14(A), it is determined whether or not the wheel chock device 70 is located at a position where the detection distance d _d = do and the detection angle θ = 0 (i.e., parallel to the longitudinal direction of the vehicle body 2). Also, when the right rear outrigger 12Rr is most extended, as shown in Figure 14(B), it is determined whether or not the wheel chock device 70 is located at a position where the detection distance d _d and detection angle θ are calculated by equations (1) and (2) described above, according to the extension amount dot of the right rear outrigger 12Rr.

In this way, by adjusting the detection direction and detection distance according to the extension amount of the outrigger device 12, even if the positional relationship between the wheel chock device 70 positioned relative to the tire wheel 5 and the wheel chock detector 100 changes due to the extension operation of the outrigger device 12, the wheel chock device 70 can be accurately detected. If the position determination unit 63 determines that the wheel chock device 70 is not properly positioned, the alarm control unit 64 can activate the alarm device 103.

<Wheel chock placement warning control>
In detecting the wheel chocks described above, the arrangement determination unit 63 shown in Figure 2 makes the following three-stage determinations regarding the arrangement of the wheel chocks 70 based on the detection results of the wheel chock detectors 100 (left front wheel chock detector 110L, left front wheel chock detector 111L, left rear wheel chock detector 112L, left rear wheel chock detector 113L, right front wheel chock detector 110R, right front wheel chock detector 111R, right rear wheel chock detector 112R, and right rear wheel chock detector 113R) and the tilt angle detector 101.

(Phase 1)
First, the placement determination unit 63 determines, based on the inclination angle of the vehicle body 2 detected by the inclination angle detector 101, whether the wheel chocks 70 are appropriately positioned for each tire wheel 5 if it determines that the road surface on which the aerial work platform 1 is parked is not flat. Here, the range of inclination angles for determining that the road surface is not flat is, for example, when the detected inclination angle exceeds a range of ±1 degree. If the placement determination unit 63 determines that the road surface is not flat, it determines, based on the detection results of each wheel chock detector 100, whether wheel chocks 70 are positioned on the front and rear sides of the left front wheel 5Lf, left rear wheel 5Lr, right front wheel 5Rf, and right rear wheel 5Rr. If the placement determination unit 63 determines that wheel chocks 70 are not positioned on the front and rear sides of at least one of the two or more tire wheels 5, the alarm control unit 64 activates the alarm device 103 to sound an alarm.

In the past, when an aerial work platform was parked on a flat surface, it was common practice to place wheel chocks on both the front and rear sides of the rear wheels. On the other hand, when an aerial work platform was parked on a ramp, it was preferable to place wheel chocks on the wheels on the downhill side. Therefore, on a gentle ramp where the vehicle's inclination angle slightly exceeds 1 degree, there is a risk that the operator might mistakenly place wheel chocks on both the front and rear sides of the rear wheels, thinking it is a flat surface, but failing to place wheel chocks on the front wheels. To address this, in the wheel chock placement warning control described above, when the aerial work platform 1 is parked on a gentle ramp, if it is determined that at least one tire wheel 5 does not have a wheel chock 70 placed on either its front or rear side, the alarm device 103 is activated. In other words, if an aerial work platform is parked on a slight incline, the worker might assume it's a flat surface and believe they can prevent it from rolling away by placing wheel chocks in front of and behind the rear wheels. However, the aforementioned alarm system alerts the worker to the fact that the aerial work platform is parked on an incline and that wheel chocks should also be placed on the downhill side of the front wheels.

(Phase 2)
Next, the placement determination unit 63 determines whether the wheel chocks 70 are positioned in front of or behind each of the tires 5, including the left front wheel 5Lf, left rear wheel 5Lr, right front wheel 5Rf, and right rear wheel 5Rr, if the inclination angle of the vehicle body 2 exceeds a predetermined angle range (for example, ±1 degree). If the orientation of the wheel chocks 70 for at least one tire 5 is different from the orientation of the wheel chocks 70 for the other tires 5, the alarm device 103 is activated to sound an alarm.

Here, for example, even if the alarm device 103 is activated in the first stage of the judgment described above, and the worker places wheel chocks 70 on all the tires 5, if the tilt angle of the vehicle body 2 is slight, it becomes difficult to determine whether the vehicle body 2 is tilted downwards or upwards, and the worker may place the wheel chocks in different orientations relative to the left and right wheels. Therefore, by activating the alarm device 103 based on the judgment result of the second stage described above, the worker can be informed that it is necessary to align the orientation of all the wheel chocks 70.

(Phase 3)
Furthermore, if the tilt angle of the vehicle body 2 exceeds a predetermined angle range (for example, ±1 degree), the placement determination unit 63 determines whether the wheel chocks 70 are properly positioned for each tire wheel 5, including the left front wheel 5Lf, left rear wheel 5Lr, right front wheel 5Rf, and right rear wheel 5Rr, according to the tilt direction of the vehicle body 2. Here, the placement determination unit 63 has in advance stored the following as the proper positioning of the wheel chocks 70 (hereinafter referred to as "proper positioning"): if the vehicle body 2 is tilted downwards from the front, the wheel chocks 70 should be positioned in front of the tire wheel 5, and if the vehicle body 2 is tilted upwards from the front, the wheel chocks 70 should be positioned behind the tire wheel 5. Based on the stored proper positioning, the unit then determines whether the positioning of the wheel chocks 70 for each tire wheel 5, including the left front wheel 5Lf, left rear wheel 5Lr, right front wheel 5Rf, and right rear wheel 5Rr, is proper. If the unit determines that the positioning of the wheel chocks 70 for all tire wheels 5 is not proper, the unit activates the alarm device 103.

In this way, by performing a third-stage judgment, for example, if the alarm device 103 activated in the second-stage judgment described above, and the worker aligned the orientation of the wheel chocks 70 for all the tires 5, but the orientation was not correct, the worker can be notified of this. This allows the worker to reverse the orientation of the wheel chocks for all the wheels (if they were positioned on the front of the tires 5, move them to the rear, and vice versa), thereby correcting the arrangement of the wheel chocks for all the wheels.

Furthermore, it is acceptable to perform only one of the three stages of judgment described above, or to perform at least two judgments in combination. When performing multiple judgments in combination, the manner of alarm operation of the alarm device 103 based on each judgment result (e.g., the flashing interval of the alarm lamp, the type and interval of the alarm sound) may be different. Also, when performing the three stages of judgment described above, if there is a position on the underside of the vehicle body 2 where the detection of the wheel chock device 70 by the wheel chock detector 100 is not obstructed by the front wheel mudguard 8f or rear wheel mudguard 8r shown in Figure 1, the wheel chock detector 100 can be installed at that position, and it is not necessarily required to fix the wheel chock detector 100 to the jack base 10B.

<Display indicating the appropriate placement according to the vehicle's tilt direction>
In the third stage of the judgment described above, the placement determination unit 63 determined whether the placement of the wheel chocks 70 was appropriate according to the inclination direction of the vehicle body 2. In the wheel chock placement indicator device of this embodiment, this appropriate placement is displayed to the operator. The display method of the appropriate placement will be described below with reference to Figures 15 and 16.

Figure 15 shows the base display configuration for indicating the correct placement to the operator. In this display configuration, the correct placement is indicated on a schematic representation of the vehicle body 2's plan view. Specifically, within the cabin display area CB, which schematically represents the driver's cabin 7 of the vehicle body 2, the following areas are defined: FLf, indicating that the wheel chock 70 is properly positioned in front of the left front wheel 5Lf; FLr, indicating that the wheel chock 70 is properly positioned behind the left front wheel 5Lf; FRf, indicating that the wheel chock 70 is properly positioned in front of the right front wheel 5Rf; and FRr, indicating that the wheel chock 70 is properly positioned behind the right front wheel 5Rf.

Furthermore, within the mounting area AC, which schematically represents the mounting area of the vehicle body 2, there is a proper placement display area RLf indicating that the front of the left rear wheel 5Lr is properly positioned for the wheel chock 70, a proper placement display area RLr indicating that the rear of the left rear wheel 5Lr is properly positioned for the wheel chock 70, a proper placement display area RRf indicating that the front of the right rear wheel 5Rf is properly positioned for the wheel chock 70, and a proper placement display area RRr indicating that the rear of the right rear wheel 5Rf is properly positioned for the wheel chock 70.
And that is stipulated.

Furthermore, the display of the correct placement may be indicated by displaying images representing each of the aforementioned display areas on an image display device such as a liquid crystal display. Alternatively, for example, the display panel may be adorned with outlines indicating the cabin display area CB and the mounting area AC, and lamps may be placed at the positions of each correct placement display area and illuminated to indicate the correct placement. In this embodiment, the display device 104 shown in Figure 2 is a liquid crystal display, and images representing each of the aforementioned display areas are displayed on this liquid crystal display.

The controller 60 stores optimal placement information in a memory (not shown) that indicates the correct placement according to the inclination direction of the vehicle body 2. This optimal placement information consists of three types: first optimal placement information, second optimal placement information, and third optimal placement information. The first optimal placement information indicates that the optimal placement is to position the wheel chocks 70 in front of each tire wheel 5. The second optimal placement information indicates that the optimal placement is to position the wheel chocks 70 in rear of each tire wheel 5. The third optimal placement information indicates that the optimal placement is to position the wheel chocks 70 both in front of and behind each tire wheel 5.

As a result, if the tilt angle of the vehicle body 2 detected by the tilt angle detector 101 exceeds a predetermined angle range, and the sign of the value indicating the tilt angle is negative (vehicle body 2 is tilted downwards at the front), the controller 60 refers to the first appropriate placement information among the appropriate placement information stored in memory. Here, the predetermined angle range mentioned above is the angle range that can be considered as a flat road, and if the angle exceeds this range, it is considered as a slope. In this embodiment, the predetermined angle range is set to ±1 degree. Since the first appropriate placement information indicates that the appropriate placement is to place the wheel chocks 70 in front of each tire wheel 5, the appropriate placement display areas FLf, FRf, RLf, and RRf are displayed in red, as shown in Figure 16(A). Note that in Figures 16(A) to (C'), the red display of the appropriate placement display areas is shown in gray.

Furthermore, if the tilt angle of the vehicle body 2 detected by the tilt angle detector 101 exceeds a predetermined angle range, and the sign of the value indicating the tilt angle is positive (vehicle body 2 is tilted forward), the controller 60 refers to the second optimal placement information stored in memory. Since the second optimal placement information indicates that the optimal placement is to position the wheel chocks 70 behind each tire wheel 5, the optimal placement display areas FLr, FRr, RLr, and RRr are displayed in red, as shown in Figure 16(B).

Furthermore, if the tilt angle of the vehicle body 2 detected by the tilt angle detector 101 is within a predetermined angle range, the controller 60 refers to the third optimal placement information among the optimal placement information stored in memory, regardless of the sign of the value indicating the tilt angle. Since the third optimal placement information indicates that the optimal placement is to position the wheel chocks 70 on both the front and rear sides of the tire wheels 5, the optimal placement display areas RLf, RLr, RRf, and RRr are each displayed in red, as shown in Figure 16(C).

Furthermore, when the controller 60 displays the optimal placement based on the third optimal placement information, the optimal placement display areas FLf, FLr, FRf, and FRr may each be displayed in red, as shown in Figure 16(C').

This allows for the reliable prevention of the aerial work platform 1 from running away, even on gently sloping surfaces where workers cannot determine whether the surface is flat or sloped simply by looking at it. By positioning the wheel chocks 70 at the location (front or rear) of the tire wheel 5 corresponding to the red-displayed appropriate placement area shown on the display device 104, the aerial work platform 1 can be reliably prevented from running away.

Furthermore, if the tilt angle of the vehicle body 2 detected by the tilt angle detector 101 exceeds a predetermined angle range, and the sign of the value indicating the tilt angle is positive (vehicle body 2 is tilted forward), the controller 60 may determine whether or not wheel chocks 70 are positioned behind the left front wheel 5Lf and right front wheel 5Rf based on the detection signals output from the left front wheel rear wheel chock detector 111L and the right front wheel rear wheel chock detector 111R. If it is determined that wheel chocks are not positioned, the controller 60 may activate the alarm device 103.

Here, if the aerial work platform 1 is parked on a ramp where the vehicle body 2 is tilted upwards from the front, and the vehicle body 2 is lifted and supported by the jacking device 10, there is a risk that the aerial work platform 1 may run away if, for example, when lowering the vehicle body 2 back onto the ramp, the unbraked front wheels touch the ground before the rear wheels, which are braked by the parking brake. Therefore, when the vehicle body 2 is parked with the front tilted upwards, it is crucial to detect whether or not wheel chocks 70 are positioned behind the left front wheel 5Lf and the right front wheel 5Rf, as described above.

In the above embodiment, the example described was a case where the system is mounted on a truck-mounted aerial work platform. However, the system is not limited to this, and may be applied to other work vehicles such as cranes, or transport vehicles such as dump trucks. Furthermore, in the above embodiment, an electric-driven (battery-driven) aerial work platform was used as an example, but the system is not limited to this. A PTO-driven aerial work platform that uses engine power via a PTO mechanism (power take-off mechanism) to drive a hydraulic pump, or a hybrid aerial work platform equipped with both and selectively switching power sources, may also be used.

1. Aerial work platform 2. Body 5. Tires/wheels 10. Jacking device 12. Outrigger device 27. Lower operating device 45. Upper operating device 60. Controller 62. Designated position identification unit 63. Placement determination unit 64. Alarm control unit 70. Wheel chocks 71. Wheel chock members 90. Handle 95. Guide unit (indicator unit)
96 Detector 98 Grip 100 Wheel chock detector 101 Tilt angle detector 102 Extension amount detector 103 Alarm device 104 Display device

Claims (4)

A wheel chock placement indicator device that indicates the placement of wheel chocks on the wheels of a vehicle,
An inclination angle detection device for detecting the inclination angle of the vehicle in the longitudinal direction,
A tilt direction determination device that determines whether the vehicle is tilted downwards or upwards based on the tilt angle detected by the tilt angle detection device,
A storage device that stores appropriate placement information indicating whether the wheel chock device should be placed in front of or behind the wheel,
A wheel chock placement indicator device comprising: reading appropriate placement information corresponding to the inclination direction of the vehicle determined by the inclination direction determination device from the storage device; and displaying the placement of the wheel chocks indicated by the read appropriate placement information. The aforementioned appropriate placement information includes a first appropriate placement information indicating that the wheel chock should be placed in front of the wheel, and a second appropriate placement information indicating that the wheel chock should be placed behind the wheel.
The wheel chock placement indicator device according to claim 1, characterized in that, if the tilt angle of the vehicle detected by the tilt angle detection device is greater than or equal to a predetermined angle and the tilt direction determined by the tilt direction determination device is downward towards the front, the display device shows a first display mode indicating that the wheel chocks should be placed in front of the wheels by referring to the first appropriate placement information stored in the storage device, and if the tilt angle of the vehicle detected by the tilt angle detection device is greater than or equal to a predetermined angle and the tilt direction determined by the tilt direction determination device is upward towards the front, the display device shows a second display mode indicating that the wheel chocks should be placed behind the wheels by referring to the second appropriate placement information stored in the storage device. The aforementioned appropriate placement information includes a third appropriate placement information indicating that the wheel chocks should be placed on both the front and rear sides of the wheels.
The wheel chock placement indicator device according to claim 2, wherein the placement indicator device, when the tilt angle of the vehicle is less than a predetermined angle as determined by the tilt angle detection device, displays a third display mode indicating that the wheel chocks should be placed on both the front and rear sides of the wheels if the appropriate placement information read from the storage device is a third appropriate placement information. A detection device for detecting the wheel chocks positioned in front of and behind the front and rear wheels of the vehicle,
The wheel chock placement indicator device according to claim 2 or 3, further comprising: an alarm device that activates an alarm if the wheel chock is not detected by the detection device in an arrangement corresponding to the display pattern shown on the arrangement display device;