Wheel chocks and safety devices for work vehicles

Abstract

To provide a wheel stopping device that can contribute to installation of a wheel stopping member in a proper position with respect to a wheel, and a safety gear of a work vehicle.SOLUTION: A portable-type wheel stopping device 101, which regulates a high-place work vehicle being parked from moving, is configured to comprise: a wheel stopping member that is installed near a tire wheel on a road surface on which the high-place work vehicle is parked; a non-contact-type distance sensor 130 that detects a distance between the tire wheel and the sensor; a control part 160 that determines whether or not the distance detected by the distance sensor 130 is within a predetermined first determination distance or less; and a display part 150 that notifies the determined result of whether the distance detected by the distance sensor 130 is within the first determination distance or not, on the basis of the determined result by the control part 160.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a wheel stopper device for restricting the movement of a work vehicle during parking and a safety device for a work vehicle.

Background Art

[0002] In work vehicles such as aerial work platforms, when the work vehicle is parked and the required work is performed, in addition to braking the wheels by a parking brake (side brake), a wedge-shaped wheel stopper is installed between the wheels and the parking road surface to prevent the vehicle from running away (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, if the wheel stopper is not properly installed on the wheel, the effect of the wheel stopper is not fully exerted, and there remains a risk that the work vehicle will run away, and there is a problem that the safety of the work cannot be sufficiently ensured.

[0005] The present invention has been made in view of such problems, and an object thereof is to provide a wheel stopper device and a safety device for a work vehicle that can contribute to the proper installation of a wheel stopper member at a proper position with respect to a wheel.

Means for Solving the Problems

[0006] To solve the above problems, a wheel stopper device according to the present invention is a portable wheel stopper device for restricting the movement of a work vehicle during parking, and includes a wheel stopper member installed in the vicinity of a wheel provided on the work vehicle on a parking road surface of the work vehicle, Provided on the wheel stopper member,A non-contact distance detection unit for detecting the distance to the wheel, Provided on the wheel stopper member, A determination unit that determines whether the distance detected by the distance detection unit is within a predetermined determination distance, Provided on the wheel stopper member, The system is characterized by comprising a notification unit that notifies whether the distance detected by the distance detection unit is within the determination distance based on the determination result of the determination unit.

[0007] In the wheel chock device according to the present invention, the device comprises two distance detection units provided on both sides in the width direction of the wheel chock member, and an alarm unit provided on the wheel chock member that emits a predetermined alarm, wherein the determination unit preferably activates the alarm unit when the distance detected by one of the distance detection units and the distance detected by the other distance detection unit differ by a predetermined value or more.

[0008] Furthermore, in the wheel chock device according to the present invention, it is preferable that the wheel chock member is provided with an inclination angle detection unit that detects the inclination angle of the wheel chock member with respect to the horizontal plane, the determination unit determines whether or not the tip of the wheel chock member is facing upward on the inclination side based on the inclination angle of the wheel chock member with respect to the horizontal plane detected by the inclination angle detection unit, and the notification unit notifies whether or not the tip of the wheel chock member is facing upward on the inclination side based on the determination result of the determination unit.

[0009] The first safety device for a work vehicle according to the present invention is provided so as to be extendable and retractable at the front and rear of the vehicle body. A safety device for a work vehicle comprising a work vehicle having jacks for supporting the vehicle body and a portable wheel chock device for restricting the movement of the work vehicle while parked, wherein the wheel chock device comprises a wheel chock member installed near the wheels of the work vehicle on the parking surface of the work vehicle, a non-contact distance detection unit for detecting the distance to the wheels, a determination unit for determining whether the distance detected by the distance detection unit is within a preset determination distance, and a transmission unit for transmitting the determination result of the determination unit, and the work vehicle comprises a receiving unit for receiving the determination result transmitted by the transmission unit.

[0010] A second safety device for a work vehicle according to the present invention comprises a work vehicle having jacks that are extendable and retractable at the front and rear of the vehicle body and support the vehicle body, and a portable wheel chock device for restricting the movement of the parked work vehicle, wherein the wheel chock device includes a wheel chock member installed on the parking surface of the work vehicle near the wheels provided on the work vehicle, Provided on the wheel stopper member, A non-contact distance detection unit for detecting the distance to the wheel, Provided on the wheel stopper member, The work vehicle comprises a transmitting unit that transmits the detection result of the distance detection unit, and is characterized by comprising a receiving unit that receives the detection result transmitted by the transmitting unit, and a distance determination unit that determines whether the distance detected by the distance detection unit is within a predetermined determination distance based on the detection result received by the receiving unit.

[0011] In the second safety device for a work vehicle according to the present invention, it is preferable that the work vehicle comprises a boom provided on the vehicle body so as to be able to move up and down at least, a ground contact detector for detecting when the jack touches the ground, and a ground contact determination unit that compares a first detection distance, which is a distance previously detected by the distance detection unit before the ground contact of the jack is detected by the ground contact detector, with a second detection distance, which is a distance detected by the distance detection unit after the ground contact of the jack is detected by the ground contact detector, and determines that the wheels have been lifted off the ground when the second detection distance is greater than or equal to a predetermined value than the first detection distance.

[0012] Furthermore, in the second safety device for a work vehicle according to the present invention, the work vehicle comprises a wheel chock storage unit for storing the wheel chock device, a wheel chock storage determination unit for determining whether or not the wheel chock device is stored in the wheel chock storage unit, a driving preparation operation detection unit for detecting whether or not a driving preparation operation for the work vehicle has been performed, and an alarm activation unit for executing a predetermined alarm operation when the driving preparation operation detection unit detects a driving preparation operation for the work vehicle while the wheel chock storage determination unit has not detected that the wheel chock device is stored in the wheel chock storage unit, wherein the wheel chock storage determination unit preferably determines that the wheel chock device is stored in the wheel chock storage unit when it determines, based on the detection result received by the receiving unit, that the distance detected by the distance detection unit is within a predetermined specific distance. [Effects of the Invention]

[0013] According to the present invention, the distance measuring unit measures the distance to the parked wheels and notifies whether the wheel chocks are installed at the appropriate distance from the wheels on the parking surface. This helps to suppress human errors such as workers mistakenly installing the wheel chocks in an inappropriate position (a position where they do not function as wheel chocks) or forgetting to install the wheel chocks, thereby preventing vehicles from running away. [Brief explanation of the drawing]

[0014] [Figure 1] A side view of an aerial work platform. [Figure 2] This is a block diagram showing the control system for an aerial work platform. [Figure 3] This is a perspective view of the wheel chock device according to the first embodiment. [Figure 4] This is a side view of the wheel chock device according to the first embodiment. [Figure 5] This is a block diagram of the wheel chock device according to the first embodiment. [Figure 6] This is a block diagram of the wheel chock device according to the second embodiment. [Figure 7] This is a perspective view of the wheel chock device according to the third embodiment. [Figure 8] It is a block diagram of the wheel stopper device of the third embodiment. [Figure 9] It is a schematic diagram for explaining the inclination angle of the wheel stopper device of the third embodiment. [Figure 10] It is a block diagram of the wheel stopper device of the fourth embodiment. [Figure 11] It is a block diagram of a safety device provided with the wheel stopper device of the fifth embodiment. [Figure 12] It is a block diagram of a safety device provided with the wheel stopper device of the sixth embodiment. [Figure 13] It is a block diagram of a safety device provided with the wheel stopper device of the seventh embodiment. [Figure 14] It is a block diagram of the wheel stopper device of the eighth embodiment. [Figure 15] It is a block diagram of the wheel stopper device of the ninth embodiment. [Figure 16] (A) is a side view showing a state where the wheel stopper device of the ninth embodiment is installed on the ground, and (B) is a side view showing a state where the wheel stopper device of the ninth embodiment is stored in the wheel stopper storage section. [Figure 17] It is a circuit diagram showing the power switch section of the wheel stopper device of the ninth embodiment. [Figure 18] It is a block diagram of a safety device provided with the wheel stopper device of the tenth embodiment. [Figure 19] It is a block diagram of a safety device provided with the wheel stopper device of the eleventh embodiment. [Figure 20] It is a block diagram of a safety device provided with the wheel stopper device of the twelfth embodiment. [Figure 21] It is a side view of the wheel stopper storage section for storing the wheel stopper device of the twelfth embodiment.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The aerial work platform 1 according to this embodiment is shown in FIG. 1. First, the overall configuration of the aerial work platform 1 will be described with reference to this figure.

[0016] 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 (front tires 5f and rear tires 5r) 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 the tires 5 (front tires 5f and rear tires 5r) are arranged, and a subframe mounted on this chassis frame.

[0017] The vehicle body 2 is equipped with jacking devices 10 on the front, rear, left, and right sides to lift and support the vehicle body 2 during work at height. The jacking devices 10 consist of a pair of front jacks 10f positioned behind the front wheels 5f and a pair of rear jacks 10r positioned behind the rear wheels 5r. Each jack 10f, 10r extends downward by driving a jack cylinder 11 located inside it, thereby lifting and supporting the vehicle body 2 and stabilizing the entire vehicle. The rear end of the vehicle body 2 is equipped with a lower operating device 27 for operating each jack 10f, 10r and the boom 30, which will be described later.

[0018] On both the left and right sides of the lower part of the vehicle body 2, between the rear wheels 5r and the rear jack 10r, there are wheel chock storage compartments 15 for storing the wheel chock devices 101, which will be described later. Note that in Figure 1, only the wheel chock storage compartment 15 attached to the lower left rear of the vehicle body 2 is shown. Here, since the two wheel chock storage compartments 15 provided on the vehicle body 2 have the same configuration, the following description will refer to the wheel chock storage compartment 15 attached to the lower left rear of the vehicle body 2 as a representative example. This wheel chock storage compartment 15 has an opening that is open in the vertical direction, and is configured so that two wheel chock devices 101 can be inserted from above as a pair. As mentioned above, since there are two wheel chock storage compartments 15 on the vehicle body 2 (on both the left and right sides), a total of four wheel chock devices 101 corresponding to the number of tires 5 (four wheels) can be stored.

[0019] In the vehicle body 2, the mounting area behind the driver's cabin 7 is driven by a swing motor 24. A slewing platform 20 is provided, which is configured to rotate horizontally around a vertical axis. The base end of the boom 30 is attached to a support column 21 extending upward from this slewing platform 20 via a foot pin 22, so that it can swing (raise and lower) in the vertical direction. In addition, toolboxes 26 for storing work tools and equipment are provided on the left and right sides of the mounting area of ​​the vehicle body 2.

[0020] The boom 30 has a configuration in which a base boom 30a, an intermediate boom 30b, and a tip boom 30c are nested together in order from the turntable 20 side. The boom 30 can be extended and retracted in the axial direction (longitudinal direction) by the extension and retraction drive of the telescopic cylinder 31 provided inside. In addition, 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 in the vertical plane.

[0021] A vertical post (not shown) is pivotally supported at the tip of the tip boom 30c so as to be able to swing up and down. This vertical post is controlled to maintain 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 via a work platform bracket (not shown). A swivel motor 34 (see Figure 2) 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. Here, as described above, the vertical post is always kept in a vertical position, and as a result, the floor surface of the work platform 40 is always kept horizontal regardless of the elevation angle of the boom 30.

[0022] The work platform 40 is equipped with an upper operating device 45 that includes various operating means such as operating levers, operating switches, and operating dials for operation by the worker riding on it. Therefore, the worker riding on the work platform 40 can perform various operations such as 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) by operating the upper operating device 45.

[0023] As shown in Figure 2, the operating mechanism of the jacking device 10 (jacks 10f, 10r) and the high-altitude work equipment (swivel platform 20, boom 30, work platform 40, etc.) installed on the vehicle body 2 is configured to include a controller 60 that receives operation signals from the upper operating device 45 and the lower operating device 27 and controls the jack cylinder 11, swivel motor 24, luffing cylinder 23, telescopic cylinder 31, and swivel motor 34, etc. (hereinafter collectively referred to as "hydraulic actuators"), and a hydraulic unit 50 that supplies hydraulic fluid to operate these hydraulic actuators.

[0024] The operation signals output by the operation of the upper operating device 45 or the lower operating device 27 are input to the controller 60. The operation control unit 61 of the controller 60 outputs a command signal corresponding to the operation signal to the hydraulic unit 50 (control valve 53).

[0025] The hydraulic unit 50 comprises a hydraulic tank 51 for storing hydraulic fluid, a hydraulic pump 52 that discharges hydraulic fluid when driven by the power of the engine E mounted on the vehicle body 2, and a control valve 53 that controls the direction and amount of hydraulic fluid supplied from the hydraulic pump 52 to each hydraulic actuator. Furthermore, a power take-off mechanism (PTO) is incorporated into the transmission that transmits the power of the engine E to the tire wheels 5. When the PTO operating lever 55 located in the driver's cabin 7 is operated from the OFF position to the ON position, the power take-off mechanism (PTO) switches the target of the engine E's drive from the tire wheels 5 to the hydraulic pump 52, and the hydraulic pump 52 is driven by the power of the engine E. On the other hand, when the PTO operating lever 55 is operated from the ON position to the OFF position, the power take-off mechanism PTO switches the target of the engine E's drive from the hydraulic pump 52 to the tire wheel 5, and the tire wheel 5 is rotated by the power of the engine E. The control valve 53 has an electromagnetic proportional control valve V1 corresponding to the jack cylinder 11, an electromagnetic proportional control valve V2 corresponding to the slewing motor 24, an electromagnetic proportional control valve V3 corresponding to the luffing cylinder 23, an electromagnetic proportional control valve V4 corresponding to the telescopic cylinder 31, and an electromagnetic proportional control valve V5 corresponding to the swivel motor 34. Based on command signals 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 V5 to control the supply direction and amount of hydraulic fluid supplied from the hydraulic pump 52 to each hydraulic actuator, and controls the operating direction and operating speed of each hydraulic actuator (controlling the operating direction and operating speed of the jack device 10 and the high-altitude work device).

[0026] In a high-altitude work vehicle 1 with this configuration, when parking at the target work site to perform the required work, the parking brake is activated to brake the left and right rear wheels 5r before starting the work (before operating each jack 10f, 10r), and then wheel chocks 101 (see Figure 1) are installed between the parking surface and each tire wheel 5 to prevent the vehicle from running away.

[0027] [First Embodiment] First, a wheel chock device 101 according to the first embodiment of the present invention will be described. In the following, for the sake of convenience of explanation, the length direction (insertion direction) of the wheel chock device 101 will be defined as the "front-to-back direction," the width direction of the wheel chock device 101 as the "left-to-right direction," and the height direction of the wheel chock device 101 as the "up-down direction," but this does not specify the direction in which the wheel chock 101 is placed (the same applies to other embodiments).

[0028] As shown in Figures 3 to 5, the wheel chock device 101 comprises a wheel chock member 120, a holding unit 126, a distance sensor 130, a power supply unit 140, a display unit 150, and a control unit 160. Although only one wheel chock device 101 is shown in Figures 3 to 5, in reality, four wheel chock devices 101 corresponding to the four tire wheels 5 are used. In the following description, when it is necessary to distinguish between the four wheel chock devices 101, they will be referred to as "wheel chock device 101A," "wheel chock device 101B," "wheel chock device 101C," and "wheel chock device 101D" for convenience (see Figure 5).

[0029] The wheel chock member 120 is formed in a wedge shape using, for example, a synthetic resin material (plastic material). This wheel chock member 120 has a ground contact portion 121 that forms the bottom and contacts the parking surface, a stopper portion 122 that receives the outer circumferential surface 5t of the tire wheel 5, a top portion 123 that forms the uppermost part, a rear portion 124 that connects the ground contact portion 121 and the top portion 123, and a pair of side portions 125. Hereinafter, as shown in Figure 4, the side of the wheel chock device 101 (wheel chock member 120) that is inserted between the outer circumferential surface 5t of the tire wheel 5 and the parking surface (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 same applies to other embodiments).

[0030] The contact surface 121 has a non-slip surface 121a formed by a continuous arrangement of peaks and valleys along the front-rear direction, which prevents slipping on the ground. The stopper surface 122 is formed as a curved surface that rises from the tip to the base and becomes concave diagonally upward, and is configured to contact or come close to the tread surface 5t of the tire wheel 5. This stopper surface 122 may be partially or entirely formed of an inclined surface. The rear surface 124 has a protruding T-shaped handle 124a for the worker to grip when carrying the wheel chock 70.

[0031] The holding portion 126 is formed in a hollow box shape using, for example, a synthetic resin material (plastic material). It is fixed to the top portion 123 of the wheel stopper member 120. On the surface side of this holding portion 126 (the side facing the outer circumferential surface 5t of the tire wheel 5), a window portion 127 is provided, which is formed in the shape of a flat plate using a translucent synthetic resin material or glass material. Inside this holding portion 126, a distance sensor 130, a power supply unit 140, and a control unit 160 are installed. In addition, a display unit 150 is attached to the upper end side of this holding portion 126.

[0032] The distance sensor 130 detects the distance to the outer surface 5t of the tire wheel 5 in a non-contact manner. This distance sensor 130 is composed of, for example, a laser sensor, and detects the distance to the object to be detected (the outer surface 5t of the tire wheel 5) by irradiating the object to be detected (the outer surface 5t of the tire wheel 5) with laser light and measuring the time it takes from the time of emission to the time of reception of the reflected laser light (the time difference between emission and reception). This distance sensor 130 irradiates the outside of the holding part 126 through a window part 127 provided in the holding part 126 and receives the reflected laser light. Here, as shown in Figure 4 as an example of the direction of laser light irradiation (arrow X direction), this distance sensor irradiates the laser light at an elevation angle (diagonally upward). Then, this distance sensor 130 detects the distance to the outer surface 5t of the tire wheel 5 and outputs a voltage signal (detection signal) corresponding to the detected distance to the control unit 160. In this embodiment, the distance sensor is configured using a laser sensor, but the system is not limited to this configuration; for example, an ultrasonic sensor may also be used.

[0033] The power supply unit 140 is composed of a rechargeable secondary battery (storage battery), such as a lithium-ion battery. The power supply unit 140 supplies the power necessary for operation to the distance sensor 130, the display unit 150, the control unit 160, etc. A power switch 141 is connected to this power supply unit 140.

[0034] The power switch 141 is an operating switch for turning the power to the wheel chock device 101 on and off. The power switch 141 is mounted on the back side of the holding part 126 (the side opposite to the window part 127). This power switch 141 is configured as, for example, a toggle switch that can be switched to either the ON position or the OFF position (it is configured to retain the switched operating position even when the operator releases their hand). When the power switch 141 is operated to the ON position, power from the power supply unit 140 is supplied to each part of the wheel chock device 101. On the other hand, when the power switch 141 is operated to the OFF position, the supply of power from the power supply unit 140 to each part of the wheel chock device 101 is cut off. This power switch 141 constitutes part of the power switching circuit of the wheel chock device 101. The power switch 141 may be, for example, a button type or a slide type power switch.

[0035] The display unit 150 includes a distance determination lamp 151 provided on one end of the upper end surface of the holding unit 126 in the left-right direction, and a power lamp 154 ​​provided on the other end of the upper end surface of the holding unit 126 in the left-right direction. The distance determination lamp 151 is an indicator lamp that lights up when the wheel chock device 101 is installed at an appropriate distance from the outer circumference 5t of the tire wheel 5. The power lamp 154 ​​is an indicator lamp that lights up when the power to the wheel chock device 101 is ON (when the power switch 141 is in the ON position). Each indicator lamp 151, 154 is composed of, for example, an LED lamp and lights up with a different luminous color. For example, the distance determination lamp 151 lights up with a green luminous color, and the power lamp 154 ​​lights up with a red luminous color. However, each indicator lamp 151, 154 may light up with the same luminous color (for example, white).

[0036] The control unit 160 is configured with a microprocessor having a CPU, ROM, RAM, etc., and controls the operation of the distance sensor 130, power supply unit 140, display unit 150, etc., to realize the function of the wheel chock device 101.

[0037] The control unit 160 controls the distance detected by the distance sensor 130 (hereinafter referred to as "detected distance"). The control unit 160 determines whether the distance detected by the distance sensor 130 is less than or equal to a preset first determination distance. That is, based on the distance detected by the distance sensor 130, the control unit 160 determines whether the wheel chock 101 is installed at an appropriate distance (near the tire wheel 5) from the outer surface 5t of the tire wheel 5. In this embodiment, for example, "10 cm" is set as the first determination distance. The control unit 160 compares the distance detected by the distance sensor 130 with the first determination distance, and if the distance detected by the distance sensor 130 is less than or equal to the first determination distance, it determines that the wheel chock 101 is installed at an appropriate distance from the outer surface 5t of the tire wheel 5, that is, the determination result (distance determination result) is OK, and lights up the distance determination lamp 151. On the other hand, if the distance detected by the distance sensor 130 exceeds the first determination distance, the control unit 160 determines that the wheel chock 101 is not installed at an appropriate distance from the outer surface 5t of the tire wheel 5, that is, the determination result (distance determination result) is NG, and turns off the distance determination lamp 151. In this embodiment, since all wheel chocks 101 (101A to 101D) perform the distance determination described above, it is possible to confirm whether the wheel chocks 101 (101A to 101D) are installed at an appropriate distance from the outer circumferential surface 5t of all tire wheels 5.

[0038] As described above, according to the first embodiment, the distance to the parked tire wheel 5 can be detected, and it is possible to notify whether the wheel chock device 101 is installed at an appropriate distance from the tire wheel 5 on the parking surface. This suppresses human errors such as the worker mistakenly installing the wheel chock device 101 in an inappropriate position (a position where it does not function as a wheel chock) or forgetting to install the wheel chock device 101, thereby preventing the vehicle from running away.

[0039] [Second Embodiment] Next, a wheel chock device 102 according to a second embodiment of the present invention will be described with reference to Figure 6. This wheel chock device 102 of the second embodiment basically has the same configuration as the wheel chock device 101 of the first embodiment. The same numbers will be used for components that are the same as those in the above embodiment (or components that have the same function), and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiment.

[0040] The wheel chock device 102 comprises a wheel chock member 120, a holding part 126, a first distance sensor 131, a second distance sensor 132, a power supply unit 140, a display unit 150, a control unit 160, and an alarm unit 190. Although only one wheel chock device 102 is shown in Figure 6, in reality, four wheel chock devices 102 corresponding to the four tire wheels 5 are used. In the following description, when it is necessary to distinguish between the four wheel chock devices 102, they will be referred to as "wheel chock device 102A," "wheel chock device 102B," "wheel chock device 102C," and "wheel chock device 102D" for convenience (see Figure 6).

[0041] Each distance sensor 131 and 132 has the same function as the distance sensor 130 of the first embodiment described above, and detects the distance to the outer circumferential surface 5t of the tire wheel 5 without contact. The first distance sensor 131 is installed inside the holding part 126 at one end (for example, the left end) in the width direction of the wheel chock device 102, and detects the distance to one end (for example, the left end) in the width direction of the outer circumferential surface 5t of the tire wheel 5. The second distance sensor 132 is installed inside the holding part 126 at the other end (for example, the right end) in the width direction of the wheel chock device 102, and detects the distance to the other end (for example, the right end) in the width direction of the outer circumferential surface 5t of the tire wheel 5. Each distance sensor 131 and 132 outputs a voltage signal (detection signal) corresponding to the detected distance to the control unit 160. Each distance sensor 131 and 132 is mounted parallel to each other at a position equidistant from the window part 127 in the front-rear direction.

[0042] The control unit 160 determines whether the detected distance of each distance sensor 131, 132 is less than or equal to a preset first determination distance. If the control unit determines that the distance is less than or equal to the first determination distance (i.e., if it determines that the wheel chock 102 is installed at an appropriate distance from the outer surface 5t of the tire wheel 5), the distance determination lamp 151 is not lit at this point. Instead, the difference (absolute value) between the distance detected by the first distance sensor 131 and the distance detected by the second distance sensor 132 is calculated, and it is determined whether or not that difference is less than or equal to a predetermined threshold. That is, the control unit 160 determines whether or not the wheel chock 102 is installed parallel to the tire wheel 5 (i.e., whether or not the distance between the tire wheel 5 and the wheel chock 102 is equidistant at both ends in the width direction) based on the difference in the detected distances of the left and right distance sensors 131 and 132. Here, if the control unit 160 determines that the wheel chock 102 is installed parallel to the tire wheel 5, that is, that the determination result (distance determination result) is OK, it lights up the distance determination lamp 151. On the other hand, if the difference between the distance detected by the first distance sensor 131 and the distance detected by the second distance sensor 132 exceeds a specified value, the control unit 160 determines that the wheel chock 102 is not installed parallel to the tire wheel 5, that is, the determination result (distance determination result) is NG, and turns off the distance determination lamp 151 and activates the alarm unit 190 provided in the holding unit 26. The alarm unit 190 can be, for example, an alarm device such as a buzzer or speaker that emits an alarm sound. This alarm unit 190 notifies that the wheel chock 102 is not installed parallel to the outer surface 5t of the tire wheel 5 by outputting an alarm sound such as a predetermined electronic sound or voice message. In this embodiment, since all wheel chocks 102 (102A to 102D) each perform the above distance determination, it is possible to confirm whether the wheel chocks 102 (102A to 102D) are installed at the appropriate distance and parallel to the outer surface 5t of all tire wheels 5.

[0043] As described above, the wheel chock device 102 according to the second embodiment can detect the distance to the parked tire wheel 5 and notify whether the wheel chock device 101 is installed at an appropriate distance from the tire wheel 5 on the parking surface. This helps to suppress human errors such as workers mistakenly installing the wheel chock device 101 in an inappropriate position (a position where it does not function as a wheel chock) or forgetting to install the wheel chock device 101, thereby preventing the vehicle from running away.

[0044] Furthermore, according to the second embodiment, it is possible to detect whether the wheel chock 102 is installed parallel to the outer surface 5t of the tire wheel 5, thereby preventing the wheel chock 102 from being installed at an angle to the left or right.

[0045] [Third Embodiment] Next, the wheel chock device 103 according to the third embodiment of the present invention will be described with reference to Figures 7 to 9. This wheel chock device 103 of the third embodiment basically has the same configuration as the wheel chock device 101 of the first embodiment. The same numbers will be used for the same configuration (or configuration with the same function) as in the above embodiment, and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiment.

[0046] The wheel chock device 103 comprises a wheel chock member 120, a holding part 126, a distance sensor 130, a tilt angle sensor 133, a power supply unit 140, a display unit 150, and a control unit 160. Although only one wheel chock device 103 is shown in Figures 7 to 9, in reality, four wheel chock devices 103 corresponding to the four tire wheels 5 are used. In the following description, when it is necessary to distinguish between the four wheel chock devices 103, they will be referred to as "wheel chock device 103A," "wheel chock device 103B," "wheel chock device 103C," and "wheel chock device 103D" for convenience (see Figure 8).

[0047] The tilt angle sensor 133 detects the tilt angle of the wheel chock device 103. The inclination angle 03 is the inclination angle of the ground contact portion 121 in the front-rear direction relative to the horizontal plane. The inclination angle sensor 133 detects the inclination angle of the wheel chock device 103 and outputs a voltage signal (detection signal) corresponding to the detected inclination angle to the control unit 160. Here, as shown in Figure 9(A), when the ground contact portion 121 is horizontal, that is, when the tip and base of the ground contact portion 121 are at the same height, the inclination angle detected by the inclination angle sensor 133 is 0 degrees. Also, as shown in Figure 9(B), when the tip of the ground contact portion 121 is higher than the base, the inclination angle detected by the inclination angle sensor 133 is a positive angle. Also, as shown in Figure 9(C), when the tip of the ground contact portion 121 is lower than the base, the inclination angle detected by the inclination angle sensor 133 is a negative angle. Therefore, the tilt angle sensor 133 can detect the orientation of the tip of the wheel chock device 103, that is, whether the tip of the wheel chock device 103 is facing downhill (downward slope) or uphill (upward slope).

[0048] As shown in Figures 7 and 8, the display unit 150 includes a distance determination lamp 151 provided on one end of the upper end surface of the holding unit 126 in the left-right direction, a tilt determination lamp 152 provided in the center of the upper end surface of the holding unit 126 in the left-right direction, and a power lamp 154 ​​provided on the other end of the upper end surface of the holding unit 126 in the left-right direction. The tilt determination lamp 152 is an indicator lamp that lights up when the wheel chock device 103 is installed in the correct orientation (tilted position). Note that the distance determination lamp 151 and the power lamp 154 ​​have already been described in the first embodiment, so a redundant explanation will be omitted here. Each indicator lamp 151, 152, and 154 is composed of, for example, an LED lamp and lights up with a different light color. For example, the distance determination lamp 151 lights up with a green light color, the tilt determination lamp 152 lights up with a yellow light color, and the power lamp 154 ​​lights up with a red light color.

[0049] Similar to the first embodiment, the control unit 160 determines whether the distance detected by the distance sensor 130 is less than or equal to the first determination distance, that is, whether the wheel chock device 103 is installed at an appropriate distance (near the tire wheel 5) from the outer surface 5t of the tire wheel 5, and turns on or off the distance determination lamp 151.

[0050] Furthermore, the control unit 160 determines whether the inclination angle detected by the inclination angle sensor 133 (hereinafter sometimes referred to as the "detected angle") is equal to or greater than a preset determination angle. In this embodiment, for example, "0 degrees" is set as the determination angle. If the detection angle of the inclination angle sensor 133 is equal to or greater than the determination angle, the control unit 160 determines that the tip of the wheel chock device 103 is facing horizontally or towards the uphill side (upward slope). On the other hand, if the detection angle of the inclination angle sensor 133 is less than the determination angle, the control unit 160 determines that the tip of the wheel chock device 103 is facing towards the downhill side (downward slope). Note that "uphill side" means the higher side of the slope, and "downhill side" means the lower side of the slope. Here, when parking a vehicle on a slope, the correct orientation when installing the wheel chock device 103 on the tire wheel 5 is when the wheel chock device 103 is positioned on the downhill side of the tire wheel 5 and the tip of the wheel chock device 103 is facing towards the uphill side. Therefore, in this embodiment, as shown in Figure 9(B), the orientation when the tip of the wheel chock 103 is facing uphill is considered the "correct orientation," and as shown in Figure 9(C), the orientation when the tip of the wheel chock 103 is facing downhill is considered the "incorrect orientation." The control unit 160 determines that the wheel chock 103 is installed in the correct orientation, i.e., the judgment result (inclination judgment result) is OK, and lights up the inclination judgment lamp 152 if the detection angle of the inclination angle sensor 133 is greater than or equal to the judgment angle. On the other hand, if the control unit 160 determines that the wheel chock 103 is installed in the inappropriate orientation, i.e., the judgment result (inclination judgment result) is NG, and turns off the inclination judgment lamp 152. In this embodiment, all wheel chocks 103 (103A~103D) perform the above distance judgment and inclination judgment, respectively, so the wheel chocks are applied to the outer circumference 5t of all tire wheels 5. It is possible to confirm whether the device 103 (103A~103D) is installed at the appropriate distance and in the appropriate orientation.

[0051] As described above, according to the third embodiment, similar to the first embodiment, the distance to the parked tire wheel 5 can be detected, and it is possible to notify whether the wheel chock device 103 is installed at an appropriate distance from the tire wheel 5 on the parking surface. This suppresses human errors such as the worker mistakenly installing the wheel chock device 103 in an inappropriate position (a position where it does not function as a wheel chock) or forgetting to install the wheel chock device 103, thereby preventing the vehicle from running away.

[0052] Furthermore, according to the third embodiment, in addition to detecting the distance to the tire wheel 5, the inclination angle of the wheel chock device 103 with respect to the horizontal plane can be detected, and it is possible to notify whether or not the tip of the wheel chock device 103 is installed facing the uphill side. This makes it possible to install the wheel chock device 103 at the appropriate distance and in the appropriate orientation relative to the tire wheel 5.

[0053] The wheel chock device 103 of the third embodiment may also be equipped with two distance sensors 131 and 132, similar to the wheel chock device 102 of the second embodiment. In that case, the control unit 160 preferably determines that the wheel chock device 103 is installed parallel to the outer surface 5t of the tire wheel 5 and lights up the distance determination lamp 151, similar to the second embodiment, when the difference between the detection distance of the first distance sensor 131 and the detection distance of the second distance sensor 132 is less than or equal to a preset value. Conversely, when the difference between the detection distance of the first distance sensor 131 and the detection distance of the second distance sensor 132 is not less than or equal to a preset value, the control unit 160 preferably determines that the wheel chock device 103 is not installed parallel to the outer surface 5t of the tire wheel 5 and turns off the distance determination lamp 151 and activates the alarm unit 190.

[0054] [Fourth Embodiment] Next, a wheel chock device 104 according to the fourth embodiment of the present invention will be described with reference to Figure 10. This wheel chock device 104 of the fourth embodiment basically has the same configuration as the wheel chock device 103 of the third embodiment. The same numbers will be used for the same configuration (or configuration with the same function) as in the third embodiment, and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the third embodiment.

[0055] The wheel chock device 104 comprises a wheel chock member 120, a holding part 126, a distance sensor 130, a tilt angle sensor 133, a power supply unit 140, a display unit 150, and a control unit 160. Although only one wheel chock device 104 is shown in Figure 10, in reality, four wheel chock devices 104 are used, corresponding to the four tire wheels 5. In the following description, when it is necessary to distinguish between the four wheel chock devices 104, they will be referred to as "wheel chock device 104A," "wheel chock device 104B," "wheel chock device 104C," and "wheel chock device 104D" for convenience (see Figure 10).

[0056] The display unit 150 includes a comprehensive judgment lamp 153 provided on one end of the upper end surface of the holding unit 126 in the left-right direction, and a power lamp 154 ​​provided on the other end of the upper end surface of the holding unit 126 in the left-right direction. The comprehensive judgment lamp 153 is an indicator lamp that lights up when the wheel chock device 104 is installed at the appropriate distance and orientation from the outer circumference 5t of the tire wheel 5. The power lamp 154 ​​has already been described in the first embodiment above, so a redundant explanation will be omitted here. Each indicator lamp 153, 154 is composed of, for example, an LED lamp and lights up with a different light color. For example, the comprehensive judgment lamp 153 lights up with a blue light color, and the power lamp 154 ​​lights up with a red light color.

[0057] The control unit 160 determines if the distance detected by the distance sensor 130 is less than or equal to the first determination distance, and the incline If the angle detected by the angle sensor 133 is greater than or equal to the judgment angle, the control unit 160 determines that the wheel chock 104 is installed at the appropriate distance and in the appropriate orientation relative to the tire wheel 5, that is, the judgment result (overall judgment result) is OK, and lights up the overall judgment lamp 153. On the other hand, if the distance detected by the distance sensor 130 exceeds the first judgment distance, or if the angle detected by the tilt angle sensor 133 is less than the judgment angle, the control unit 160 determines that the wheel chock 104 is not installed at the appropriate distance and in the appropriate orientation relative to the tire wheel 5, that is, the judgment result (overall judgment result) is NG, and turns off the overall judgment lamp 153. In this embodiment, since all wheel chocks 104 (104A to 104D) perform the above overall judgment (distance judgment and tilt judgment), it is possible to confirm whether the wheel chocks 104 (104A to 104D) are installed at the appropriate distance and in the appropriate orientation relative to the outer circumference 5t of all tire wheels 5.

[0058] As described above, according to the fourth embodiment, similar to the first embodiment, the distance to the parked tire wheel 5 can be detected, and it is possible to notify whether the wheel chock device 104 is installed at an appropriate distance from the tire wheel 5 on the parking surface. This suppresses human errors such as the worker mistakenly installing the wheel chock device 104 in an inappropriate position (a position where it does not function as a wheel chock) or forgetting to install the wheel chock device 104, thereby preventing the vehicle from running away.

[0059] Furthermore, according to the fourth embodiment, the distance to the tire wheel 5 and the inclination angle of the wheel chock device 104 are detected, and a single indicator lamp (overall judgment lamp 153) can notify that the wheel chock device 104 is installed at an appropriate distance from the tire wheel 5 and on the downhill side of the slope. This makes it easy to confirm whether or not the wheel chock device 104 is correctly installed relative to the tire wheel 5.

[0060] [Fifth Embodiment] Next, a safety device 205 equipped with a wheel chock device 105 according to the fifth embodiment of the present invention will be described with reference to Figure 11. This wheel chock device 105 of the fifth embodiment basically has the same configuration as the wheel chock device 101 of the first embodiment. The same numbers will be used for the same configuration (or configuration with the same function) as in the above embodiment, and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiment.

[0061] The wheel chock device 105 comprises a wheel chock member 120, a holding unit 126, a distance sensor 130, a power supply unit 140, a display unit 150, a control unit 160, and a transmission unit 170. Although only one wheel chock device 105 is shown in Figure 11, in reality, four wheel chock devices 105 corresponding to the four tire wheels 5 are used. In the following description, when it is necessary to distinguish between the four wheel chock devices 105, they will be referred to as "wheel chock device 105A," "wheel chock device 105B," "wheel chock device 105C," and "wheel chock device 105D" for convenience (see Figure 11).

[0062] The transmitter 170 is electrically connected to the control unit 160 and converts the electrical signal indicating the determination result information (distance determination result) generated by the control unit 160 into a radio signal (wireless signal). The transmitter 170 then wirelessly transmits this radio signal (determination result information) at predetermined time intervals, for example, in accordance with a short-range wireless communication standard such as Bluetooth® or ZigBee®. In addition to the determination result information (distance determination result), this radio signal includes unique identification information (ID information) for identifying its own wheel chock device 105 (in this embodiment, four wheel chock devices 105A to 105D). The transmitter 170 is not limited to radio signals; for example, it may transmit optical signals using infrared rays or transmit electrical signals via wired connections such as electrical cables.

[0063] As shown in Figure 11, the safety device 205 mainly consists of a wheel chock 105, a vehicle-side receiver 70, and a controller 60.

[0064] The vehicle-side receiving unit 70 is located on the vehicle body 2 near the controller 60. This vehicle-side receiving unit 70 is configured as a wireless receiver capable of wireless communication with the transmitters 170 of all wheel chocks 105 (four wheel chocks 105A to 105D in this embodiment). This vehicle-side receiving unit 70 receives radio signals (judgment result information) wirelessly transmitted from the transmitters 170 of each wheel chock 105 (105A to 105D), converts them into electrical signals, and transmits these electrical signals (judgment result information) to the controller 60.

[0065] The controller 60 includes an operation control unit 61 and an interlock control unit 65.

[0066] As described above, the operation control unit 61 controls the operation of the boom 30, jacks 10f, 10r, etc., by electromagnetically driving the control valve 53 to operate each hydraulic actuator based on operation signals from the upper operating device 45 or the lower operating device 27.

[0067] The interlock control unit 65, based on the judgment result information (distance judgment results for the four wheel chocks 105A to 105D) transmitted from the vehicle-side receiver 70, allows the extension and retraction of the jacks 10f and 10r in response to the operation of the lower operating device 27 if all distance judgment results are OK, that is, if all wheel chocks 105 are installed at the appropriate distance from the tire wheel 5. On the other hand, if all distance judgment results are not OK (if any one of the distance judgment results is NG), the interlock control unit 65 restricts the extension and retraction of the jacks 10f and 10r regardless of the operation of the lower operating device 27. The interlock control unit 65 identifies which wheel chock 105 (105A to 105D) the judgment result information (distance judgment result) belongs to by detecting the ID information of each wheel chock 105 (105A to 105D) from the electrical signals received from the vehicle-side receiver 70 (the same applies to other embodiments).

[0068] Furthermore, the operation restriction of jacks 10f and 10r by the interlock control unit 65 is carried out by imposing an operation restriction on the operation control unit 61, such as preventing the operation control unit 61 from receiving the operation signal even when jack operation is performed, or preventing the electromagnetic proportional control valve V1 corresponding to the jack cylinder 11 from being electromagnetically driven even if the operation control unit 61 receives an operation signal based on jack operation. In addition to this operation restriction of jacks 10f and 10r, an alarm may also be activated, for example, by sounding an alarm, using an alarm lamp or displaying an alarm, to alert the worker.

[0069] As described above, according to the fifth embodiment, it is possible to prevent the jacks 10f and 10r from extending or retracting when the wheel chock device 105 is not installed at an appropriate distance from the outer circumference 5t of the tire wheel 5. This suppresses human errors such as the worker mistakenly installing the wheel chock device 101 in an inappropriate position (a position where it does not function as a wheel chock) or forgetting to install the wheel chock device 101, thereby preventing the vehicle from running away.

[0070] [Sixth Embodiment] Next, a safety device 206 equipped with a wheel chock device 106 according to the sixth embodiment of the present invention will be described with reference to Figure 12. This safety device 206 of the sixth embodiment basically has the same configuration as the safety device 205 of the fifth embodiment. The same numbers will be used for the same configuration (or configuration with the same function) as in the above embodiments, and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiments.

[0071] The wheel chock device 106 includes a wheel chock member 120, a holding part 126, a distance sensor 130, and an electric The system comprises a power source 140, a display unit 150, a control unit 161, and a transmission unit 170. Although Figure 12 shows only one wheel chock 106, in reality, four wheel chocks 106 corresponding to the four tire wheels 5 are used. In the following description, when it is necessary to distinguish between the four wheel chocks 106, they will be referred to as "wheel chock 106A," "wheel chock 106B," "wheel chock 106C," and "wheel chock 106D" for convenience (see Figure 12).

[0072] The control unit 161 controls the operation of the distance sensor 130, power supply unit 140, transmission unit 170, etc., to realize the function of the wheel chock device 106. Unlike the control unit 160 in the above embodiment, this control unit 161 does not have a determination device that determines whether the distance detected by the distance sensor 130 is within the first determination distance. Therefore, the display unit 150 does not have a distance determination lamp 151, and only a power lamp 154 ​​is provided.

[0073] The transmitting unit 170 is electrically connected to the distance sensor 130 via the control unit 161. The transmitting unit 170 converts the electrical signal (detection information) output from the distance sensor 130 into a radio signal and wirelessly transmits this radio signal (detection information) at predetermined time intervals in accordance with short-range wireless communication standards such as Bluetooth® or ZigBee®.

[0074] The safety device 206 mainly consists of a wheel chock 106, a vehicle-side receiver 70, and a controller 60.

[0075] The vehicle-side receiving unit 70 is located on the vehicle body 2 near the controller 60. This vehicle-side receiving unit 70 is configured as a wireless receiver capable of wireless communication with the transmitting units 170 of all wheel chock devices 106 (four wheel chock devices 106A to 106D in this embodiment). This vehicle-side receiving unit 70 receives radio signals (detection result information) wirelessly transmitted from the transmitting unit 170 of each wheel chock device 106, converts them into electrical signals, and transmits these electrical signals (detection result information) to the controller 60.

[0076] The controller 60 comprises an operation control unit 61, a distance determination unit 62, and an interlock control unit 65.

[0077] The distance determination unit 62 has the same function as the control unit 160 of the wheel chock device 101 in the first embodiment, and performs the same determination process as the distance determination performed by the control unit 160. Specifically, the distance determination unit 62 determines whether the distance detected by the distance sensor 130 is less than or equal to a preset first determination distance based on the detection result information transmitted from the vehicle-side receiving unit 70. That is, the distance determination unit 62 determines whether the wheel chock device 106 is installed at an appropriate distance (near the tire wheel 5) from the outer circumferential surface 5t of the tire wheel 5, based on the distance detected by the distance sensor 130. As this first determination distance, for example, "10 cm" is set, as in the first embodiment. Here, if the distance detection distance of each distance sensor 130 is less than or equal to the first determination distance, the distance determination unit 62 determines that the wheel chock device 106 is installed at an appropriate distance from the outer circumferential surface 5t of the tire wheel 5. On the other hand, if the distance detected by each distance sensor 130 exceeds the first determination distance, the distance determination unit 62 determines that the wheel chocks 106 are not installed at an appropriate distance from the outer surface 5t of the tire wheel 5. This distance determination is performed for each of the wheel chocks 106 (106A to 106D).

[0078] The interlock control unit 65, if the distance determination unit 62 determines that all wheel chocks 106 (106A to 106D) are installed at an appropriate distance from the outer surface 5t of each tire wheel 5, allows the jacks 10f and 10r to extend and retract in response to the operation of the lower operating device 27. On the other hand, the interlock control unit 65, if the distance determination unit 62 determines that all wheel chocks 106 (106A to 106D) are installed at an appropriate distance from each tire wheel 5, allows the jacks 10f and 10r to extend and retract in response to the operation of the lower operating device 27. If it is determined that the wheels are not properly positioned (at least one of the wheel chocks 106 is not installed at the appropriate distance from the tire wheel 5), the extension and retraction of the jacks 10f and 10r will be restricted regardless of the operation of the lower operating device 27.

[0079] As described above, according to the sixth embodiment, similar to the fifth embodiment, it is possible to prevent the jacks 10f and 10r from extending or retracting when the wheel chock device 106 is not installed at an appropriate distance from the outer circumference 5t of the tire wheel 5. This suppresses human errors such as the worker mistakenly installing the wheel chock device 106 in an improper position (a position where it does not function as a wheel chock) or forgetting to install the wheel chock device 106, thereby preventing the vehicle from running away.

[0080] [Seventh Embodiment] Next, a safety device 207 equipped with a wheel chock device 107 according to the seventh embodiment of the present invention will be described with reference to Figure 13. This safety device 207 of the seventh embodiment basically has the same configuration as the safety device 206 of the sixth embodiment. The same numbers will be used for the same configuration (or configuration with the same function) as in the above embodiments, and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiments.

[0081] The wheel chock device 107 comprises a wheel chock member 120, a holding unit 126, a distance sensor 130, a power supply unit 140, a display unit 150, a control unit 161, and a transmission unit 170. Although only one wheel chock device 107 is shown in Figure 13, in reality, four wheel chock devices 107 are used, corresponding to the four tire wheels 5. In the following description, when it is necessary to distinguish between the four wheel chock devices 107, they will be referred to as "wheel chock device 107A," "wheel chock device 107B," "wheel chock device 107C," and "wheel chock device 107D" for convenience (see Figure 13).

[0082] The safety device 207 mainly consists of a wheel chock device 107, a vehicle-side receiving unit 70, a jack ground contact detector 80, and a controller 60.

[0083] Each jacking device 10 is equipped with a jack grounding detector 80 that detects whether or not the jacks 10f and 10r are in contact with the ground (parking surface). The jack grounding detector 80 is composed of, for example, limit switches, and outputs an ON signal when the jacks 10f and 10r are in contact with the ground, and an OFF signal in any other state. Each jack grounding detector 80 is electrically connected to a controller 60, and the detection signals (ON signal, OFF signal) output from the jack grounding detector 80 are input to the controller 60. Note that, for space reasons, only one jack grounding detector 80 is shown in Figure 13, but in reality, four jack grounding detectors 80 are provided to correspond to the four jacking devices 10.

[0084] The controller 60 includes an operation control unit 61, a distance determination unit 62, a distance storage unit 63, a ground clearance determination unit 64, an interlock control unit 65, and an alarm activation unit 69.

[0085] The distance determination unit 62, similar to the sixth embodiment described above, determines whether the detection distance of each distance sensor 130 is less than or equal to a preset first determination distance based on the detection result information transmitted from the vehicle-side receiving unit 70. If the detection distance of each distance sensor 130 is less than or equal to the first determination distance, it determines that the wheel chock device 107 is installed at an appropriate distance from the outer circumferential surface 5t of the tire wheel 5. If the detection distance of each distance sensor 130 exceeds the first determination distance, it determines that the wheel chock device 107 is not installed at an appropriate distance from the outer circumferential surface 5t of the tire wheel 5.

[0086] Furthermore, when the jack ground contact detector 80 detects that all jacks 10f and 10r are not in a grounded state, the distance determination unit 62 determines that the detected distance of each distance sensor 130 is less than or equal to the first determination distance, and stores this detected distance in the distance storage unit 63 as the detected distance when all jacks 10f and 10r are not in a grounded state (hereinafter referred to as the "reference distance").

[0087] When the extension operation of the jacks 10f and 10r is performed and the jack contact detector 80 detects that all jacks 10f and 10r are in contact with the ground, the ground-off determination unit 64 compares the distance detected by the distance sensor 130 sent from the vehicle-side receiving unit 70 with the reference distance stored in the distance storage unit 63 to determine whether each tire wheel 5 has lifted off the ground (performs ground-off determination for the tire wheel 5). Here, the ground-off determination unit 64 determines that the tire wheel 5 has lifted off the ground (the tire wheel 5 has left the ground) when the distance detected by the distance sensor 130 becomes greater than the reference distance stored in the distance storage unit 63 by a predetermined value (for example, 3 cm). This ground-off determination is performed for each of the distance sensor 130 detection results of all wheel chocks 107A to 107D. In other words, it is basically assumed that a wheel chock device 107 is installed on each of the four tires 4, and based on the detection results of the distance sensors 130 of the four wheel chock devices 107A to 107D, it is determined whether or not all four tires 5 are off the ground.

[0088] Similar to the sixth embodiment described above, the interlock control unit 65 allows the extension and retraction of the jacks 10f and 10r in response to the operation of the lower operating device 27 if the distance determination unit 62 determines that all wheel chocks 107 (107A to 107D) are installed at an appropriate distance from the outer surface 5t of each tire wheel 5. On the other hand, if the distance determination unit 62 determines that all wheel chocks 107 (107A to 107D) are not installed at an appropriate distance from each tire wheel 5 (at least one of the wheel chocks 107 is not installed at an appropriate distance from the tire wheel 5), the interlock control unit 65 restricts the extension and retraction of the jacks 10f and 10r regardless of the operation of the lower operating device 27.

[0089] Furthermore, if the ground clearance determination unit 64 determines that all tire wheels 5 are off the ground (meaning the detected distances of all distance sensors 130 are greater than a predetermined value or more than the reference distance stored in the distance memory unit 63), the interlock control unit 65 allows the boom 30 to operate in response to the operation of the upper operating device 45. On the other hand, if the ground clearance determination unit 64 does not determine that all tire wheels 5 are off the ground (meaning that at least one tire wheel 5 is not off the ground), the interlock control unit 65 restricts the operation of the boom 30 regardless of the operation of the upper operating device 45.

[0090] When the lower operating device 27 is performing the retraction operation of the jacks 10f and 10r (when the lower operating device 27 outputs a retraction operation signal for the jacks 10f and 10r), the alarm activation unit 69 determines, based on the detection result information of the distance sensor 130 sent from the vehicle-side receiving unit 70, whether the detected distance of the distance sensor 130 is less than or equal to a preset second determination distance. That is, during the retraction operation of the jacks 10f and 10r (during the retraction operation), the alarm activation unit 69 determines, based on the detected distance of the distance sensor 130, whether the wheel chocks 107 are installed near the bottom of the tire wheels 5, i.e., whether the wheel chocks 107 have not been put away. In this embodiment, for example, "30 cm" is set as the second determination distance. Here, if the detected distance of the distance sensor 130 is less than or equal to the second determination distance, the alarm activation unit 69 determines that the wheel chocks 107 are installed near the bottom of the tire wheels 5. On the other hand, if the detection distance of the distance sensor 130 is not less than or equal to the second determination distance, the alarm activation unit 69 determines that a wheel chock 107 is not installed near the lower part of the tire wheel 5 and activates the alarm device 90 installed in the vehicle body 2 or the driver's cabin 7. For the device 90, for example, an alarm device such as a buzzer or speaker that emits an alarm sound can be applied. This alarm device 90 notifies that the wheel chock device 107 is not installed near the bottom of the tire wheel 5 while the jacks 10f and 10r are being retracted by outputting an alarm sound such as a predetermined electronic sound or voice message. Here, the case in which the distance between the wheel chock device 107 and the tire wheel 5 is not within the second determination distance while the jacks 10f and 10r are being retracted is, for example, when the wheel chock device 107 has been removed from the parking surface after the vehicle has been jacked up, or when the position or orientation of the wheel chock device 107 has shifted during the work. The reason for setting the second judgment distance (e.g., 30 cm) to a larger value than the first judgment distance (e.g., 10 cm) is that the detection distance of the distance sensor 130 (distance from the tire wheel 5) fluctuates depending on the extension amount of the jacks 10f and 10r, and when the vehicle is jacked up and jacked down, the parking position before jacking up and the parking position after jacking down may shift forward or backward (the contact position of the tire wheel 5 may shift forward or backward from its original contact position), so this amount is added as a margin.

[0091] As described above, according to the seventh embodiment, similar to the fifth embodiment, it is possible to prevent the jacks 10f and 10r from extending or retracting when the wheel chock device 107 is not installed at an appropriate distance from the outer circumference 5t of the tire wheel 5. This suppresses human errors such as the worker mistakenly installing the wheel chock device 107 in an improper position (a position where it does not function as a wheel chock) or forgetting to install the wheel chock device 107, thereby preventing the vehicle from running away.

[0092] Furthermore, according to the seventh embodiment, by comparing the distance to the parked tire wheel 5 before and after the jacks 10f and 10r touch the ground, it is possible to determine whether the tire wheel 5 has lifted off the ground (whether the jacks 10f and 10r are in a state of lifting and supporting the vehicle body 2) based on the amount of change. This makes it possible to reliably detect when the tire wheel 5 has lifted off the ground without relying on the operator's visual judgment.

[0093] In addition, according to the seventh embodiment, the distance to the tire wheel 5 can be detected while the jacks 10f and 10r are being retracted, and it can be determined whether or not a wheel chock device 107 is installed near the bottom of the tire wheel 5. This further reduces the risk of the vehicle running away when jacking up and jacking down.

[0094] [Eighth Embodiment] Next, a wheel chock device 108 according to the eighth embodiment of the present invention will be described with reference to Figure 14. This eighth embodiment of the wheel chock device 108 basically has the same configuration as the wheel chock device 101 of the first embodiment. The same numbers will be used for components that are the same as those in the above embodiments (or components that have the same function), and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiments.

[0095] The wheel chock device 108 comprises a wheel chock member 120, a holding part 126, a distance sensor 130, a power supply unit 140, a display unit 150, a control unit 160, and a tilt switch 180. Although only one wheel chock device 108 is shown in Figure 14, in reality, four wheel chock devices 108 are used, corresponding to the four tire wheels 5. In the following description, when it is necessary to distinguish between the four wheel chock devices 108, they will be referred to as "wheel chock device 108A," "wheel chock device 108B," "wheel chock device 108C," and "wheel chock device 108D" for convenience (see Figure 14).

[0096] The tilt switch 180 is electrically connected to the power supply unit 140 and supplies and cuts off power from the power supply unit 140 to each part of the wheel chock device 108 in accordance with the change in the tilt angle of the wheel chock device 108. Here, the tilt angle of the wheel chock device 108 is the same as in the first embodiment described above, etc. When the ground contact portion 121 of the stopper member 120 is horizontal (when the tip and base of the ground contact portion 121 are at the same height), it is defined as "0 degrees". A positive angle occurs when the tip of the ground contact portion 121 is higher than the base, and a negative angle occurs when the tip of the ground contact portion 121 is lower than the base.

[0097] The tilt switch 180 is a mechanical tilt switch that switches the ON / OFF state of the contacts (between terminals) by the physical movement of a metal ball enclosed inside, for example. The ON / OFF state of the contacts of this tilt switch 180 differs depending on whether the tilt angle of the wheel chock device 108 is within a predetermined angle range or not. In this embodiment, the predetermined angle range is designed to be, for example, "-10 degrees to +10 degrees". This predetermined angle range is set to correspond to the allowable tilt angle of the parking surface (-7 degrees to 3 degrees: negative values ​​indicate a downward angle) on which the aerial work platform 1 can operate (can stably support the vehicle body 2). In other words, the fact that the tilt angle of the wheel chock device 108 is within the predetermined angle range means that the wheel chock device 108 is in a position installed on the parking surface of the aerial work platform 1 (i.e., the wheel chock device 108 is installed on the tire wheel 5). Therefore, the tilt switch 180 supplies power to each part of the wheel chock 108 by turning its contacts ON (energized) when the tilt angle of the wheel chock 108 is within a predetermined angle range, that is, when the wheel chock 108 is in the position installed on the parking surface. On the other hand, the tilt switch 180 cuts off the power supply to each part of the wheel chock 108 by turning its contacts OFF (de-energized) when the tilt angle of the wheel chock 108 is outside the predetermined angle range, that is, when the wheel chock 108 is not in the position installed on the parking surface.

[0098] As described above, according to the eighth embodiment, the power is turned ON when the wheel chock 108 is installed on the parking surface and turned OFF when the wheel chock 108 is not installed on the parking surface. This suppresses unnecessary power consumption of the power supply unit 140, prevents the power from being cut off while the wheel chock 108 is in use, and eliminates the need to turn the power ON / OFF when starting or ending work, thereby improving the usability and workability of the wheel chock 108. Furthermore, in the eighth embodiment, as in the first embodiment, it is possible to contribute to the proper positioning of the wheel chock 108 relative to the tire wheel 5.

[0099] [Ninth Embodiment] Next, the wheel chock device 109 according to the ninth embodiment of the present invention will be described with reference to Figures 15 to 17. This wheel chock device 109 of the ninth embodiment basically has the same configuration as the wheel chock device 101 of the first embodiment. The same numbers will be used for the same configuration (or configuration with the same function) as in the above embodiment, and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiment.

[0100] The wheel chock device 109 comprises a wheel chock member 120, a distance sensor 130, a power supply unit 140, a display unit 150, a control unit 160, and a power switch unit 181. In the following description, the electronic devices (electronic equipment) such as the distance sensor 130, the display unit 150, and the control unit 160 may be collectively referred to as "electronic device D". Also, although only one wheel chock device 109 is shown in Figures 15 and 16, in reality, four wheel chock devices 109 corresponding to the four tire wheels 5 are used. In the following description, when it is necessary to distinguish between the four wheel chock devices 109, they will be referred to as "wheel chock device 109A", "wheel chock device 109B", "wheel chock device 109C", and "wheel chock device 109D" for convenience (see Figure 15).

[0101] As shown in Figure 17, the power switch unit 181 includes a first tilt switch 182, a second tilt switch 183, and a latch circuit 184.

[0102] Each tilt switch 182, 183 is mounted inside the holding part 126. The tilt switches 182 and 183 are non-contact tilt switches that incorporate detection elements such as photointerrupters inside the switches, and are normally closed tilt switches that turn ON within a certain angular range (±10 degrees in this embodiment) relative to the horizontal state. As shown in Figure 16(A), the first tilt switch 182 is mounted so that it is in a horizontal state when the tilt angle of the wheel chock device 109 is 0 degrees. Therefore, the first tilt switch 182 turns ON when the tilt angle of the wheel chock device 109 is within a first angular range (0 degrees ± 10 degrees) and outputs an ON signal as a detection signal. As shown in Figure 16(B), the second tilt switch 183 is mounted at an angle of 70 degrees relative to the first tilt switch 182 so that it is in a horizontal state when the tilt angle of the wheel chock device 109 is at a predetermined angle (-70 degrees). Therefore, the second tilt switch 183 turns ON when the tilt angle of the wheel chock device 109 is within the second angle range (-70 degrees ± 10 degrees), and outputs an ON signal as a detection signal.

[0103] The first angle range is set to the range of inclination angles that the wheel chock device 109 can take when installed on the parking surface, that is, the angle range corresponding to the allowable inclination angle of the parking surface on which the wheel chock device 109 is placed. Specifically, this first angle range is set to an angle range (0 degrees ± 10 degrees) obtained by adding a predetermined margin to the allowable inclination angle of the parking surface of the aerial work platform 1 (for example, -7 degrees to 3 degrees: negative values ​​indicate a downward angle).

[0104] The second angle range is set to the range of inclination angles that the wheel chock 109 can take when stored in the wheel chock storage section 15, that is, the angle range corresponding to the storage posture of the wheel chock 109. This storage posture of the wheel chock 109 is a posture in which the wheel chock 109 is tilted by a predetermined angle (-70 degrees in this embodiment) with respect to the horizontal plane, that is, a posture in which the inclination angle of the wheel chock 109 is a predetermined angle (-70 degrees). As a result, when the wheel chock 109 is stored in the wheel chock storage section 15, the inclination angle of the wheel chock 109 becomes a predetermined angle (-70 degrees). Therefore, this second angle range is set to an angle range (-70 degrees ± 10 degrees) which is obtained by adding a predetermined margin to the inclination angle (-70 degrees) when the wheel chock 109 is stored in the wheel chock storage section 15.

[0105] As shown in Figure 17, the latch circuit 184 includes a first relay 185, a second relay 186, and a third relay 187. The contacts 185a of the first relay 185 and 186a of the second relay 186 are normally open contacts, while the contact 187a of the third relay 187 is normally closed contact. The first relay 185 is connected to the first tilt switch 182, and the third relay 187 is connected to the second tilt switch 183. The contact 187a of the third relay 187 is connected to the power supply unit 140, and is also connected to the contacts 185a of the first relay 185 and 186a of the second relay 186, respectively. The contacts 185a of the first relay 185 and 186a of the second relay 186 are connected in parallel to each other and are also connected to the electronic device D.

[0106] Now, let's explain the operation of the power switch 181. First, when the wheel chock 109 is installed on the ground (parking surface) and the tilt angle of the wheel chock 109 is within the first angle range, the first tilt switch 182 turns ON, which switches the first relay 185 from OFF to ON, and the contact 185a of this first relay 185 closes. As a result, power from the power supply unit 140 is supplied to the electronic device D (each part of the wheel chock 109) via contacts 187a and 185a. Also, when the contact 185a of the first relay 185 closes, the second relay 186 switches from OFF to ON, and the contact 186a of this second relay 186 closes. Therefore, even if the wheel chock device 109 is tilted (the tilt angle of the wheel chock device 109 is outside the first angle range) and the first tilt switch 182 is turned OFF (the contact 185a of the first relay 185 opens), as long as the second tilt switch 183 is not turned ON, the second relay 186 will remain ON, and the power from the power supply unit 140 will be supplied to the electronic device D (wheel chock device) via contacts 187a and 186a. It is supplied to each part of the 109.

[0107] On the other hand, when the wheel chock 109 is stored in the wheel chock storage unit 15 and the tilt angle of the wheel chock 109 falls within the second angle range, the second tilt switch 183 turns ON, which switches the third relay 187 from ON to OFF, opening the contact 187a of the third relay 187. When the contact 187a of the third relay 187 opens, the second relay 186 switches from ON to OFF, opening the contact 186a of this second relay 186. As a result, the contacts 185a to 187a of all relays 185 to 187 are open, and the power supply to the electronic device D (each part of the wheel chock 109) is cut off. In other words, when the wheel chock 109 is stored in the wheel chock storage unit 15, the power to the wheel chock 109 is cut off (power is shut off).

[0108] As described above, according to the ninth embodiment, the power is turned ON when the wheel chock device 109 is installed on the parking surface and turned OFF when the wheel chock device 109 is stored in the wheel chock storage unit 15. This suppresses unnecessary power consumption of the power supply unit 140, prevents the power from being cut off while the wheel chock device 109 is in use, and eliminates the need to turn the power ON / OFF when starting or ending work, thereby improving the usability and workability of the wheel chock device 109. Furthermore, in the ninth embodiment, as in the first embodiment, it is possible to contribute to the proper positioning of the wheel chock device 109 relative to the tire wheel 5.

[0109] [Tenth Embodiment] Next, a safety device 210 equipped with a wheel chock device 110 according to the 10th embodiment of the present invention will be described with reference to Figure 18. The wheel chock device 110 of this 10th embodiment basically has the same configuration as the wheel chock device 109 of the 9th embodiment described above. The same numbers will be used for the same configuration (or configuration with the same function) as in the above embodiment, and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiment.

[0110] The wheel chock device 110 comprises a wheel chock member 120, a distance sensor 130, a power supply unit 140, a display unit 150, a control unit 161, a transmission unit 170, and a power switch unit 181. In the following description, as with the ninth embodiment described above, the electronic devices (electronic equipment) such as the distance sensor 130, the display unit 150, the control unit 161, and the transmission unit 170 may be collectively referred to as "electronic device D". Although only one wheel chock device 110 is shown in Figure 18, in reality, four wheel chock devices 110 corresponding to the four tire wheels 5 are used. In the following description, when it is necessary to distinguish between the four wheel chock devices 110, they will be referred to as "wheel chock device 110A", "wheel chock device 110B", "wheel chock device 110C", and "wheel chock device 110D" for convenience (see Figure 18).

[0111] In addition to the aforementioned first tilt switch 182 (see Figure 17), second tilt switch 183 (see Figure 17), and latch circuit 184 (see Figure 17), the power switch unit 181 is also provided with a delay circuit 188 that delays the power cutoff of the wheel chock device 110 by a predetermined time. This delay circuit 188 keeps the power ON until a predetermined time (for example, 5 minutes) has elapsed, even when the tilt angle of the wheel chock device 110 falls within the second angle range (when the wheel chock device 110 is in the retracted state), and then turns the power OFF when that predetermined time has elapsed.

[0112] The transmitting unit 170 wirelessly transmits detection information to the vehicle-side receiving unit 70, as detection information from the second tilt switch 183, indicating whether or not the tilt angle of the wheel chock device 110 is within the second angle range. Even if the tilt angle of the wheel chock device 110 is within the second angle range (even if the second tilt switch 183 is turned OFF), the timing of the wheel chock device 110's power being turned OFF is delayed by a predetermined time by the delay circuit 188. Therefore, until that predetermined time has elapsed, the transmitting unit 170 continues to transmit the detection information from the second tilt switch 183 to the vehicle-side receiving unit 70. It can be transmitted wirelessly.

[0113] The safety device 210 mainly consists of a wheel chock device 110, a driving preparation detector 81, a vehicle-side receiving unit 70, and a controller 60.

[0114] The driving preparation detector 81 detects whether or not a driving preparation operation has been performed on the vehicle (aerial work platform 1). Driving preparation operations are preparatory operations performed before the vehicle starts moving, and include, for example, switching the PTO operation lever 55 from the ON position to the OFF position, releasing the parking brake (handbrake), and opening and closing the door of the driver's cabin 7 in order to get into the driver's seat. This driving preparation detector 81 consists of, for example, a PTO detector that detects the operating state of the PTO operation lever 55 (ON / OFF state of the power take-off mechanism PTO), a parking brake sensor that detects whether or not the parking brake is engaged, and a door opening / closing sensor that detects the opening and closing of the door of the driver's cabin 7.

[0115] The controller 60 includes an operation control unit 61, a distance determination unit 62, an interlock control unit 65, a wheel chock retraction determination unit 67, a driving preparation determination unit 68, and an alarm activation unit 69. Note that the operation control unit 61, the distance determination unit 62, and the interlock control unit 65 are the same as those described in the sixth embodiment above, so a redundant explanation is omitted here.

[0116] The wheel chock storage determination unit 67 determines, based on the detection information from the second tilt switch 183, whether the wheel chock device 110 is stored in the wheel chock storage unit 15 (stored state). Here, the wheel chock storage determination unit 67 determines that the wheel chock device 110 is in the stored state when the second tilt switch 183 is ON (when the tilt angle of the wheel chock device 110 is within the second angle range). On the other hand, the wheel chock storage determination unit 67 determines that the wheel chock device 110 is not in the stored state (not in the stored state) when the second tilt switch 183 is OFF.

[0117] The driving preparation determination unit 68 determines, based on the detection information from the driving preparation detector 81, whether or not the vehicle has undergone a driving preparation operation (i.e., whether or not the vehicle has reached the stage before it is in a driving state (driving preparation state)).

[0118] The alarm activation unit 69 activates an alarm device 90 located inside the driver's cabin 7 to warn the driver about forgetting to retract the wheel chocks 110 after completing the work, when the wheel chock storage determination unit 67 has determined that the wheel chocks 110 are not in the retracted state, and the driving preparation determination unit 68 has determined that the vehicle has been prepared to drive.

[0119] As described above, according to the 10th embodiment, if the wheel chock device 110 is not stored in the wheel chock storage unit 15 when the vehicle is prepared to drive, the alarm device in the driver's cabin 7 is activated to alert the operator, thereby effectively preventing the operator from forgetting to store the wheel chock device 110. In addition, the 10th embodiment, as in the above embodiment, can contribute to the proper placement of the wheel chock device 110 on the tire wheel 5, and can also suppress the generation of unnecessary power consumption of the power supply unit 140.

[0120] [Embodiment No. 11] Next, a safety device 211 equipped with a wheel chock device 111 according to the 11th embodiment of the present invention will be described with reference to Figure 19. The wheel chock device 111 of this 11th embodiment basically has the same configuration as the wheel chock device 109 of the 9th embodiment. The same numbers will be used for components that are the same as those in the above embodiments (or components that have the same function), and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiments.

[0121] The wheel chock device 111 comprises a wheel chock member 120, a distance sensor 130, a power supply unit 140, a display unit 150, a control unit 161, a transmission unit 170, and a power switch unit 181. Unlike the tenth embodiment, the power switch unit 181 does not include a delay circuit 188. Although only one wheel chock device 111 is shown in Figure 19, in reality, four wheel chock devices 111 corresponding to the four tire wheels 5 are used. In the following description, when it is necessary to distinguish between the four wheel chock devices 111, they will be referred to as "wheel chock device 111A," "wheel chock device 111B," "wheel chock device 111C," and "wheel chock device 111D" for convenience (see Figure 19).

[0122] The safety device 211 mainly consists of a wheel chock device 111, a driving preparation detector 81, a wireless power supply device 91, a current sensor 82, a vehicle-side receiver 70, and a controller 60.

[0123] The wireless power supply device 91 is a power supply device that transmits and receives power wirelessly, for example, by using electromagnetic induction, and mainly consists of a power transmission unit 92 provided on the vehicle body 2 and a power receiving unit 142 provided on the wheel chock device 111. This wireless power supply device 91 is configured to charge the power supply unit 140 of the wheel chock device 111 when the wheel chock device 111 is stored in the wheel chock storage unit 15.

[0124] The power transmission unit 92 is located in the lower part of the vehicle body 2, near the wheel chock storage unit 15. This power transmission unit 92 is configured with a power transmission coil 93 and is electrically connected to a power supply unit (not shown) provided in the vehicle (e.g., a vehicle battery).

[0125] The power receiving unit 142 is provided on the holding part 126 of the wheel chock device 111. This power receiving unit 142 is configured to have a power receiving coil 143 and is electrically connected to the power supply unit 140. When the wheel chock device 111 is stored in the wheel chock storage unit 15, the power transmitting unit 92 (power transmitting coil 93) and the power receiving unit 142 (power receiving coil 143) are arranged facing each other.

[0126] In the wireless power supply device 91 with the above configuration, the transmitting coil 93 generates a magnetic field corresponding to the power (AC power) input from a power supply unit (not shown). The receiving coil 143 is magnetically coupled to the transmitting coil 93 and receives power wirelessly from the transmitting coil 93 by generating an induced electromotive force through electromagnetic induction (converting the magnetic energy transmitted from the transmitting coil 93 into electrical energy and outputting it). The power (AC power) output from the receiving coil 143 is adjusted by a rectifier circuit (not shown) (converted into DC power with a voltage value appropriate for charging the power supply unit 140) and then applied to the power supply unit 140. As a result, the power supply unit 140 is charged by this wireless power supply device 91.

[0127] The current sensor 82 detects the current (charging current) supplied from the wireless power supply device 91 to the power supply unit 140. Alternatively, this current sensor 82 may detect the current flowing through the power transmission coil 93 or the power receiving coil 143.

[0128] The controller 60 includes an operation control unit 61, a distance determination unit 62, an interlock control unit 65, a charging determination unit 66, a wheel chock retraction determination unit 67, a driving preparation determination unit 68, and an alarm activation unit 69. Note that the operation control unit 61, the distance determination unit 62, and the interlock control unit 65 are the same as those described in the sixth embodiment above, so a redundant explanation is omitted here.

[0129] The charging determination unit 66 determines whether the power supply unit 140 is in a charging state based on the detection information from the current sensor 82. Here, the charging determination unit 66 determines that the power supply unit 140 is charging if it determines that a current of a certain threshold or higher is flowing based on the detection information from the current sensor 82.

[0130] The wheel chock storage determination unit 67 determines that the wheel chock device 111 is stored in the wheel chock storage unit 15 if the charging determination unit 66 has determined that the power supply unit 140 is in a charging state. In other words, in this embodiment, in order to charge the power supply unit 140 of the wheel chock device 111 with the wireless power supply device 91, it is necessary to store the wheel chock device 111 in the wheel chock storage unit 15. Therefore, it is possible to determine whether the wheel chock device 111 is stored in the wheel chock storage unit 15 based on whether or not the power supply unit 140 of the wheel chock device 111 is in a charging state.

[0131] The driving preparation determination unit 68 determines, based on the detection information from the driving preparation detector 81, whether or not the vehicle has performed a driving preparation operation (whether or not the vehicle has reached the stage before it is in a driving state (driving preparation state)).

[0132] The alarm activation unit 69 activates an alarm device 90 located inside the driver's cabin 7 to warn the driver about forgetting to retract the wheel chocks 111 after completing the work, when the wheel chock storage determination unit 67 has determined that the wheel chocks 111 are not retracted, and the driving preparation determination unit 68 has determined that the vehicle has been prepared to drive.

[0133] As described above, according to the 11th embodiment, similar to the 10th embodiment, if the vehicle is prepared for driving while the wheel chocks 111 are not stored in the wheel chock storage unit 15, the alarm device 90 in the driver's cabin 7 is activated to alert the operator, thereby effectively preventing the operator from forgetting to store the wheel chocks 111. In addition, similar to the above embodiments, the 11th embodiment can contribute to the proper placement of the wheel chocks 111 on the tire wheels 5, and can also suppress the generation of unnecessary power consumption in the power supply unit 140.

[0134] [Twelfth Embodiment] Next, a safety device 212 equipped with a wheel chock device 112 according to the 12th embodiment of the present invention will be described with reference to Figures 20 to 21. The wheel chock device 112 of this 12th embodiment basically has the same configuration as the wheel chock device 106 of the 6th embodiment described above. The same numbers will be used for the same configuration (or configuration with the same function) as in the above embodiment, and redundant explanations will be omitted. The description will mainly focus on the parts that differ from the above embodiment.

[0135] The wheel chock device 112 comprises a wheel chock member 120, a holding part 126, a distance sensor 130, a power supply unit 140, a control unit 161, and a transmission unit 170. Although only one wheel chock device 112 is shown in Figures 20 and 21, in reality, four wheel chock devices 112 are used, corresponding to the four tire wheels 5. In the following description, when it is necessary to distinguish between the four wheel chock devices 112, they will be referred to as "wheel chock device 112A," "wheel chock device 112B," "wheel chock device 112C," and "wheel chock device 112D" for convenience (see Figure 20).

[0136] Here, Figure 21 is a side view of the wheel chock storage section 15 of the twelfth embodiment. The wheel chock storage section 15 comprises a support section 16 provided at the lower part of the vehicle body 2, a storage section body 17 provided in the middle of the support section 16, and a bracket section 18 provided at the end of the storage section body 17. The storage section body 17 is formed in a frame shape with an opening in the vertical direction and is configured to be able to lock the outer shape of the wheel chock device 112 (ground contact section 121, stopper section 122, side section 125) (preventing the wheel chock device 112 from falling out downwards). The bracket section 18 is formed in a shape that covers the window section 127 side of the holding section 126 of the wheel chock member 112 from below when the wheel chock member 112 is in the stored state.

[0137] In the wheel chock storage unit 15 with this configuration, the wheel chock device 112 is inserted into the storage unit body 17 from above and stored. When the wheel chock device 112 is stored in the wheel chock storage unit 15, the window portion 127 side of the holding portion 26 of the wheel chock device 112 is positioned close to or in contact with the bracket portion 18, and the distance sensor 130 built into the holding portion 126 and the bracket portion 18 are in a positional relationship where they face each other at very close range via the window portion 127. Therefore, when the wheel chock device 112 is stored in the wheel chock storage unit 15, the distance detected by the distance sensor 130 is the distance between the distance sensor 130 and the bracket portion 18 (very close distance).

[0138] The safety device 212 mainly consists of a wheel chock device 112, a driving preparation detector 81, a vehicle-side receiving unit 70, and a controller 60.

[0139] The controller 60 includes an operation control unit 61, a distance determination unit 62, an interlock control unit 65, a wheel chock retraction determination unit 67, a driving preparation determination unit 68, and an alarm activation unit 69. Note that the operation control unit 61, the distance determination unit 62, and the interlock control unit 65 are the same as those described in the sixth embodiment above, so a redundant explanation is omitted here.

[0140] The wheel chock storage determination unit 67 determines, based on the detection information from the distance sensor 130, whether the detected distance of the distance sensor 130 is less than or equal to a preset third determination value. In this embodiment, for example, "2 cm" is set as the third determination value. Here, the wheel chock storage determination unit 67 determines that if the detected distance of the distance sensor 130 is less than or equal to the third determination value, that is, if the distance between the distance sensor 130 and the object is less than or equal to the third determination value, the object is the bracket portion 18 of the wheel chock storage unit 15, that is, the wheel chock device 112 is stored in the wheel chock storage unit 15. In this embodiment, even when the stopper portion 122 of the wheel chock device 112 is installed in close contact with the outer surface of the tire wheel 5, the distance detected by the distance sensor 130 is designed to be sufficiently longer than the third determination value (2 cm) (for example, there is a gap of about 5 cm between the window portion 127 and the object). Therefore, by using this third determination value (2 cm) as a threshold, it is possible to clearly determine whether the wheel chock device 112 is stored in the wheel chock storage unit 15 or installed on the tire wheel 5.

[0141] The driving preparation determination unit 68 determines, based on the detection information from the driving preparation detector 81, whether or not the vehicle has performed a driving preparation operation (whether or not the vehicle has reached the stage before it is in a driving state (driving preparation state)).

[0142] The alarm activation unit 69 activates an alarm device 90 located inside the driver's cabin 7 to warn the driver about forgetting to retract the wheel chocks 112 after completing the work, when the wheel chock storage determination unit 67 has determined that the wheel chocks 112 are not retracted and the driving preparation determination unit 68 has determined that the vehicle has been prepared to drive.

[0143] As described above, according to the 12th embodiment, similar to the 10th embodiment, if the vehicle is prepared to drive while the wheel chock 112 is not stored in the wheel chock storage unit 15, the alarm device 90 in the driver's cabin 7 is activated to alert the operator, thereby effectively preventing the operator from forgetting to store the wheel chock 112. Furthermore, if the vehicle is prepared to drive while the wheel chock 112 is still installed on the parking surface, the alarm device in the driver's cabin 7 is activated to alert the operator, thereby preventing situations where the operator starts driving the vehicle without noticing the wheel chock 112, that is, situations where the vehicle hits the wheel chock 112 and comes to a sudden stop, or where the vehicle drives over the wheel chock 112 and becomes unstable, thereby ensuring driving safety. Also, in the 12th embodiment, similar to the above embodiments, it is possible to contribute to the proper placement of the wheel chock 112 relative to the tire wheel 5. .

[0144] It should be noted that the present invention is not limited to the embodiments described above, and modifications can be made as appropriate without departing from the spirit of the invention. Furthermore, combinations of the components described in the embodiments described above, or modifications in which some of the components described in the embodiments are deleted or replaced with well-known or conventional technologies, are also included within the scope of the present invention.

[0145] For example, the wheel chocks 105 to 112 of the 5th to 12th embodiments are not equipped with a tilt angle sensor 133, but the configuration is not limited to this, and a tilt angle sensor 133 may be provided, similar to the wheel chocks 103 and 104 of the 3rd and 4th embodiments. In that case, it is preferable that the control unit 160 or controller 60 determines whether the tilt angle of the wheel chocks 105 to 112 is greater than or equal to a preset determination angle, that is, whether the wheel chocks 105 to 112 are installed in the correct orientation (the front ends of the wheel chocks 105 to 112 are installed facing the uphill side).

[0146] Furthermore, in the sixth to seventh embodiments and the tenth to twelfth embodiments, the wheel chocks 106, 107, 110, 111, and 112 do not have a control unit 161 that performs distance determination, and therefore the display unit 150 does not have a distance determination lamp 151. However, the configuration is not limited to this, and the display unit 150 may be equipped with a distance determination lamp 151. In that case, the determination result (distance determination result) of the distance determination unit 62 of the controller 60 may be transmitted to the wheel chocks 106, 107, 110, 111, and 112, and the control unit 161 may perform control to turn the distance determination lamp 151 on or off according to this distance determination result.

[0147] Furthermore, in the above embodiment, the wheel chock device may be equipped with a distance sensor 130 and a tilt angle sensor 133, and the system may be configured to determine whether the vehicle body 2 has become horizontal based on the extension operation of the jacks 10f and 10r, using the distance detected by the distance sensor 130 of the wheel chock device installed on the front wheel 5f side, the distance detected by the distance sensor 130 of the wheel chock device installed on the rear wheel 5r side, and the angle detected by the tilt angle sensor 133 of the wheel chock device installed on the front wheel 10f side or the rear wheel 10r side. In other words, the system may be configured to determine whether the vehicle body 2 is extended horizontally or not by calculating the inclination angle of the parking surface based on the angle detected by the inclination angle sensor 133, and then calculating the inclination angle of the vehicle body 2 with respect to the horizontal plane by the control unit 160 or controller 60 of the wheel chock device based on the distance detected by the distance sensor 130 of the wheel chock device installed on the front wheel 5f side (distance to the front wheel 5f), the distance detected by the distance sensor 130 of the wheel chock device installed on the rear wheel 5r side (distance to the rear wheel 5r), and the distance between the front and rear tires 5f and 5r which is determined for each wheelbase of the vehicle body 2 (a known value). In this case, if it is determined that the vehicle body 2 is not in a horizontal state, it is preferable to restrict the operation of the boom 30, etc.

[0148] Furthermore, in the above embodiment, the distance determination lamp 151 was lit when the distance determination result of the control unit 160 was OK, but the configuration is not limited to this. When the distance determination result of the control unit 160 is OK, the distance determination lamp 151 may be blinked, and the blinking speed may be increased or decreased as the detection angle of the distance sensor 130 becomes shorter (as it approaches the outer surface 5t of the tire wheel 5).

[0149] Furthermore, although a wireless power supply device 91 was used as an example in the 11th embodiment, the configuration is not limited to this, and a wired charging device using a charging cable may also be used.

[0150] Furthermore, in the above embodiment, a truck-mounted aerial work platform is exemplified as a work vehicle. Although described above, the invention is not limited to this, and other work vehicles such as rail-road work vehicles, bridge inspection vehicles, and crane vehicles may also be used. Furthermore, although the above embodiment described an example of a PTO-driven aerial work platform in which engine power is taken out by a PTO mechanism (power take-off mechanism) to drive a hydraulic pump, the invention is not limited to this, and an electric-driven (battery-driven) aerial work platform or a hybrid aerial work platform equipped with both and selectively switching the power source may also be used. [Explanation of Symbols]

[0151] 1. Aerial work platform (work vehicle) 2 car bodies 5 Tire Wheels 10 Jacking device 15 Wheel chock storage section 30 Boom 40 workbenches 60 Controllers 61 Operation Control Unit 62 Distance determination unit 64 Ground Clearance Determination Unit 65 Interlock control unit 66 Charge determination section 67 Wheel chock storage determination unit 68 Driving preparation determination unit 69 Alarm activation unit 70 Vehicle-side receiving unit (receiving unit) 81. Driving preparation detector (driving preparation operation detection unit) 82 Current Sensor 90 Alarm device 91 Wireless power supply device (charging device) 101 Wheel chock device (first embodiment) 102 Wheel chock device (second embodiment) 103 Wheel chock device (third embodiment) 104 Wheel chock device (fourth embodiment) 105 Wheel chock device (5th embodiment) 106 Wheel chock device (6th embodiment) 107 Wheel chock device (7th embodiment) 108 Wheel chock device (8th embodiment) 109 Wheel chock device (9th embodiment) 110 Wheel chock device (10th embodiment) 111 Wheel chock device (11th embodiment) 112 Wheel chock device (12th embodiment) 120 Wheel stopper member 130 Distance sensor (distance detection unit) 131 First distance sensor (one distance detection unit) 132 Second distance sensor (other distance detection unit) 133 Tilt Angle Sensor (Tilt Angle Detection Unit) 140 Power supply section 141 Power switch 150 Display Unit (Notification Unit) 154 Power indicator light 160 Control Unit (Determination Unit) 170 Transmitter 180 tilt switch 181 Power switch 182 First Incline Switch 183 Second tilt switch 184 Latch Circuit 190 Alarm section 205 Safety device (Fifth embodiment) 206 Safety device (6th embodiment) 207 Safety device (7th embodiment) 210 Safety device (10th embodiment) 211 Safety device (11th embodiment) 212 Safety device (12th embodiment) D Electronic equipment

Claims

1. A portable wheel chock device for restricting the movement of parked work vehicles, A wheel stopper member installed near the wheels of the work vehicle on the parking surface of the work vehicle, The wheel stopper member is provided with a non-contact distance detection unit that detects the distance to the wheel, A determination unit is provided on the wheel stopper member and determines whether the distance detected by the distance detection unit is within a predetermined determination distance, A wheel chock device characterized by comprising a notification unit provided on the wheel chock member, which notifies whether or not the distance detected by the distance detection unit is within the determination distance based on the determination result of the determination unit.

2. The wheel stopper member comprises two distance detection units provided on both sides in the width direction, and an alarm unit provided on the wheel stopper member that emits a predetermined alarm. The wheel chock device according to claim 1, characterized in that the determination unit activates the alarm unit when the distance detected by one of the distance detection units differs from the distance detected by the other distance detection unit by a specified value or more.

3. The wheel stopper member is provided with an inclination angle detection unit that detects the inclination angle of the wheel stopper member with respect to the horizontal plane, The determination unit determines whether the tip of the wheel stopper member is facing upwards on the inclination, based on the inclination angle of the wheel stopper member with respect to the horizontal plane detected by the inclination angle detection unit. The wheel chock device according to claim 1 or 2, characterized in that the notification unit notifies whether or not the tip of the wheel chock member is facing upward on an inclined side, based on the determination result of the determination unit.

4. A safety device for a work vehicle comprising a work vehicle having jacks that are extendable and retractable at the front and rear of the vehicle body and support the vehicle body, and a portable wheel chock device that restricts the movement of the work vehicle while it is parked, The wheel chock device is A wheel stopper member installed near the wheels of the work vehicle on the parking surface of the work vehicle, A non-contact distance detection unit for detecting the distance to the wheel, A determination unit that determines whether the distance detected by the distance detection unit is within a predetermined determination distance, The system comprises a transmission unit that transmits the determination result of the determination unit, The aforementioned work vehicle is, A safety device for a work vehicle, characterized by comprising a receiving unit that receives the determination result transmitted by the transmitting unit.

5. A safety device for a work vehicle comprising a work vehicle having jacks that are extendable and retractable at the front and rear of the vehicle body and support the vehicle body, and a portable wheel chock device that restricts the movement of the work vehicle while it is parked, The wheel chock device is A wheel stopper member installed near the wheels of the work vehicle on the parking surface of the work vehicle, The wheel stopper member is provided with a non-contact distance detection unit that detects the distance to the wheel, The wheel stopper member is provided with a transmitting unit that transmits the detection result of the distance detection unit, The aforementioned work vehicle is, A receiving unit that receives the detection result transmitted by the transmitting unit, A safety device for a work vehicle, comprising: a distance determination unit that determines whether the distance detected by the distance detection unit is within a predetermined determination distance based on the detection result received by the receiving unit.

6. The aforementioned work vehicle is, A boom is provided on the vehicle body so as to be able to be raised and lowered, A grounding detector for detecting the grounding of the jack, The safety device for a work vehicle according to claim 5, further comprising a ground clearance determination unit that compares a first detection distance, which is a distance previously detected by the distance detection unit before the ground contact of the jack is detected by the ground contact detector, with a second detection distance, which is a distance detected by the distance detection unit after the ground contact of the jack is detected by the ground contact detector, and determines that the wheel has been lifted off the ground when the second detection distance is greater than or equal to a predetermined value than the first detection distance.

7. The aforementioned work vehicle is, A wheel chock storage section for storing the wheel chock device, A wheel chock storage determination unit that determines whether or not the wheel chock device is stored in the wheel chock storage unit, A driving preparation operation detection unit detects whether or not the driving preparation operation for the aforementioned work vehicle has been performed, The vehicle is equipped with a wheel chock storage determination unit that, when the wheel chock storage determination unit has not detected that the wheel chock device has been stored in the wheel chock storage unit, the vehicle preparation operation detection unit detects that the vehicle is preparing to travel, and the vehicle is equipped with a warning activation unit that performs a predetermined warning operation. The safety device for a work vehicle according to claim 5 or 6, characterized in that the wheel chock storage determination unit determines, based on the detection result received by the receiving unit, that the distance detected by the distance detection unit is within a predetermined specific distance, and that the wheel chock device is stored in the wheel chock storage unit.

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