Retractable loading platform lifting device and vehicle

Abstract

To move a loading platform to a predetermined position automatically under regulatory conditions to increase efficiency of operator's behavior.SOLUTION: A retractable loading platform lifting device draws a loading platform retracted below a frame of a vehicle to move up or down the loading platform and includes: guide rails provided at a lower part of the frame and extending in a front-back direction; sliders configured to move along the guide rails; slider cylinders configured to move the sliders; arms which connect the loading platform to the sliders in a manner that enables the loading platform to move up or down; lift cylinders which move up or down the loading platform; and a control device which controls the slide cylinders. The control device can perform automatic control in which the slide cylinders are automatically driven to move the loading platform to a predetermined position when a preparation signal which is a predetermined input signal is input.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a retractable load-receiving platform lifting and lowering device in which a load-receiving platform is stored under a vehicle frame, and to a vehicle equipped with the same. [Background technology]

[0002] The loading platform lifting device lifts and lowers the loading platform between the height of the loading platform floor of the vehicle and the height of the ground, and supports the loading and unloading of luggage and the like from the loading platform of the vehicle. Among the loading platform lifting devices, there is an underfloor storage type that retracts the loading platform under the vehicle frame and stores it there (see Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6357450 Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle equipped with a storage-type load-receiving platform lifting device, after using the load-receiving platform for loading and unloading work, the load-receiving platform is pulled under the vehicle frame to a storage position where it hits a stopper, and then the vehicle travels and moves. In this case, even if the load-receiving platform appears to be in a storage state, strictly speaking, the load-receiving platform may not be in the storage position. Depending on the distance (amount of pulling out) of the load-receiving platform from the storage position, it may be difficult to visually determine that the load-receiving platform is not in the storage position. For example, as described in Patent Document 1, in the case of a storage-type load-receiving platform lifting device, it is known that the load-receiving platform is pulled out slightly from the storage position and used as a step when climbing up and down a cargo box. The load-receiving platform after being used as a step is also an example in which it is difficult to visually determine that it is not in the storage position. In this way, the state in which the load-receiving platform is pulled out slightly is difficult to visually determine, and there is a possibility that the worker will drive the vehicle without noticing that the load-receiving platform is not securely stored in the storage position. In particular, when the worker is in a hurry to move to the next site, such a situation may not be noticed.

[0005] Even if the platform can be used as a step as in Patent Document 1, for example, in a situation where time is tight, it is expected that a worker in a hurry to work may find the operation of pulling out the platform as a step troublesome, or may forget to pull out the platform to use it as a step, and may climb up to the platform directly from the ground without using the step. In particular, workers who are confident in their physical abilities or tall workers who can climb up to the platform directly from the ground without using the step may neglect to use the platform as a step because they dislike the trouble of pulling out the platform.

[0006] An object of the present invention is to provide a retractable loading platform lifting device and a vehicle that can automatically move the loading platform to a predetermined position under specified conditions, thereby making it possible to efficiently operate workers. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a retractable loading platform lifting device that pulls out and raises and lowers a loading platform stored under the frame of a vehicle, the device comprising a guide rail extending forward and backward provided on the bottom of the frame, a slider that moves along the guide rail, a slide cylinder that moves the slider, an arm that connects the loading platform to the slider so that it can be raised and lowered, a lift cylinder that raises and lowers the loading platform, and a control device that controls the slide cylinder, wherein the control device is capable of performing automatic control to automatically drive the slide cylinder to move the loading platform to a predetermined position when a preparatory signal, which is a predetermined input signal, is input. Effect of the Invention

[0008] According to the present invention, the loading platform can be automatically moved to a predetermined position under specified conditions, thereby making the actions of the worker more efficient. Therefore, it is not necessary to stop the vehicle while the vehicle is moving and to operate the loading platform lifting device, which is not stored in the storage position, to the storage position. In addition, it is not necessary to pull out the loading platform when moving to the loading platform. In particular, since the loading platform lifting device can be accurately moved to a predetermined position while the vehicle is moving, a stable storage state can be ensured. In addition, since the step can be easily and reliably used by the worker moving between the loading platform and the ground, it also helps to ensure the safety of the worker. [Brief description of the drawings]

[0009] [Figure 1] 1 is a side view showing the configuration and operation of a retractable loading platform lifting device according to an embodiment of the present invention; [Diagram 2] 2 is a circuit diagram of a hydraulic drive device provided in the platform lifting device shown in FIG. 1. [Diagram 3] 2 is a functional block diagram of a control device provided in the platform lifting and lowering device shown in FIG. 1. [Figure 4] 4 is a timing chart illustrating the control of the pull-out operation and pull-in operation of the loading platform by a first control unit of a control device provided in the loading platform lifting device shown in FIG. [Diagram 5] 4 is a diagram illustrating an operation procedure when using steps for the load-receiving platform in the load-receiving platform lifting and lowering device shown in FIG. 1. [Figure 6] 4 is a flowchart showing a control procedure for the step-using operation of the loading platform by a second control unit of the control device provided in the loading platform lifting and lowering device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] -Retractable loading platform lifting device- Fig. 1 is a side view showing the configuration and operation of a retractable load-receiving platform lifting / lowering device according to one embodiment of the present invention. In this specification, the left and right of Fig. 1 are defined as the front and rear of the retractable load-receiving platform lifting / lowering device. In this embodiment, the front-rear direction of the load-receiving platform lifting / lowering device 100 coincides with the front-rear direction of a vehicle V equipped with the load-receiving platform lifting / lowering device 100.

[0012] The load-receiving platform lifting device 100 shown in Fig. 1 is of an underfloor storage type, and is mounted on the rear underside of the frame C of a vehicle V so as to be located below a cargo box (loading platform) B, and the load-receiving platform 1 stored under the frame C is pulled out to the rear of the vehicle V to raise and lower it. The load-receiving platform lifting device 100 is configured so that different operational controls are performed depending on whether the load-receiving platform 1 is used for loading and unloading luggage (load-handling work) or whether a worker uses the load-receiving platform 1 as a step on which he or she places his or her feet.

[0013] 1(a) to 1(e) show the stages in which the receiving platform 1 of the receiving platform lifting device 100 changes from a state stored under the floor to a state in which loading and unloading of luggage is possible, and also show a first operating device R1 used by an operator when operating the changing state. In Fig. 1(a) to 1(e), the buttons of the first operating device R1 to be pressed are shown in black. In addition, a second operating device R2 is provided below the cargo box B and used when the receiving platform 1 is used as a step.

[0014] In this embodiment, a first operating device R1 and a second operating device R2 are provided separately. The first operating device R1 is an operating device (e.g., a remote control) for cargo handling work that draws out the cargo receiving platform 1 and raises and lowers it, and is used to take the cargo receiving platform 1 in and out or pull it out backwards to raise and lower it when loading and unloading cargo. The series of operations shown in Fig. 1(a) to Fig. 1(e) are performed by operating the first operating device R1. The second operating device R2 is, for example, a stationary type operating device dedicated to taking in and out the cargo receiving platform 1, which cannot be operated to raise and lower the cargo receiving platform 1, but only operates to pull it out and in, and is used when using the cargo receiving platform 1 as a step as shown in Fig. 5 later.

[0015] 1(a) shows the load receiving platform lifting device 100 in the storage position. The storage position refers to a state in which the load receiving platform 1 is stored so that the vehicle V can travel. As shown in the figure, the rear face of the load receiving platform 1 folded and positioned in the storage position is pulled in slightly forward of the rear end of the cargo box B. The load receiving platform 1 in the storage position also serves as the rear bumper of the vehicle V.

[0016] The load receiving platform lifting device 100 is provided at the rear of a vehicle frame C whose longitudinal direction is the fore-aft direction of the vehicle V, below a cargo box B mounted on the vehicle frame C, and is equipped with a foldable load receiving platform 1, a slide drive unit 2 which moves the load receiving platform 1 in the fore-aft direction of the vehicle V, a lift drive unit 3 which raises and lowers the load receiving platform 1, and a control device 6 (FIG. 3) which controls these drives 2, 3. The load receiving platform 1, slide drive unit 2, and lift drive unit 3 have known configurations (for example, JP 2013-208942 A), and the load receiving platform 1 moves in the fore-aft direction by the slide drive unit 2, and moves in the up-down direction by the lift drive unit 3.

[0017] The slide drive unit 2 includes left and right guide rails 21, left and right sliders 22, a connecting member 23, and left and right slide cylinders 24. The guide rails 21 are attached to the underside of the vehicle frame C with the longitudinal direction being the front-rear direction. The guide rails 21 are provided with front and rear stoppers (not shown) that regulate the range of movement of the slider 22 in the front-rear direction. The front stopper is a stopper that receives the slider 22 at the storage position of the load receiving platform 1. The rear stopper is a stopper that receives the slider 22 at the second pull-out position (described later) of the load receiving platform 1. The slider 22 is supported by the guide rails 21 and slides along the guide rails 21. The connecting member 23 connects the left and right sliders 22. The slide cylinders 24 have their ends fixed to the guide rails 21 and the slider 22, respectively. The slider 22 slides back and forth in accordance with the extension and contraction of the slide cylinder 24, and the load-receiving platform 1 moves back and forth together with the slider 22.

[0018] The lifting drive unit 3 includes a pair of left and right tilt arms 31, lift arms 32, compression arms 33, and lift cylinders 34. The tilt arm 31 has an upper end rotatably connected to a bracket (not shown) fixed to the connecting member 23. The lift arm 32 has a front end rotatably connected to the tilt arm 31 and a rear end rotatably connected to the load receiving platform 1. The compression arm 33 has a front end rotatably connected to the bracket and a rear end rotatably connected to the load receiving platform 1. The lift cylinder 34 has one end (rod side) rotatably connected to the lower end of the tilt arm 31 and the other end (bottom side) rotatably connected to the lift arm 32. The lift arm 32 and the compression arm 33 form a parallel link that connects the loading platform 1 to the slider 22 so that it can be raised and lowered. This parallel link rotates up and down in conjunction with the extension and contraction of the lift cylinder 34, thereby causing the loading platform 1 to rise and fall while maintaining a horizontal position.

[0019] As shown in Fig. 1(b), when the "down" button of the first operating device R1 is pressed while the loading platform 1 is in the storage position, the slider 22 slides rearward along the arrow A1. This action moves the loading platform 1 to the first pull-out position, protruding rearward a distance L1 (approximately 100 mm) from the rear end of the box B.

[0020] When the "Down" button is pressed while the loading platform 1 has moved backward to the first pull-out position, the loading platform 1 descends along the arrow A2 as shown in Fig. 1(c). This action moves the loading platform 1 to the first lowered position, where it is slightly lowered so as to move away from the cargo box B.

[0021] When the "Down" button is pressed again with the loading platform 1 lowered to the first lowered position, the loading platform 1 slides rearward along the arrow A3 as shown in Fig. 1(d). This action moves the loading platform 1 to the second drawn-out position (where the slider 22 hits the rear stopper) protruding rearward by a distance L2 from the rear end of the box B, allowing the loading platform 1 to be raised or lowered.

[0022] If the "Down" button is further pressed when the loading platform 1 has moved backward to the second pull-out position, the loading platform 1 will descend along the arrow A4, as shown in Figure 1(e). It will then descend to the second lowered position where it touches the ground. When the loading platform 1 reaches the second lowered position, the worker stops operating the "Down" button and manually unfolds the V-shaped loading platform 1 to a horizontal position (not shown).

[0023] The series of pull-out operations shown in Fig. 1 can be performed simply by pressing the "down" button on the first operating device R1, and are simple operations for the worker. When the "up" button on the first operating device R1 is pressed, the unfolded load-receiving platform 1 rises while remaining in a horizontal position. When returning the load-receiving platform 1 to the storage position after using the load-receiving platform lifting device 100, the load-receiving platform 1 is manually folded into a "L" shape as shown in Fig. 1(e), and then the "up" button on the first operating device R1 is pressed, which continuously performs the reverse movement (pulling-in movement) of the series of movements shown in Fig. 1.

[0024] -Hydraulic drive unit- FIG. 2 is a circuit diagram of the hydraulic drive unit 4 provided in the platform lifting and lowering device 100 according to this embodiment.

[0025] The hydraulic drive unit 4 shown in FIG. 2 includes an electric motor 41, a hydraulic pump 42 driven by the electric motor 41, an oil tank 43 provided on the suction side of the hydraulic pump 42, a first pressure oil supply passage 4b ​​that supplies pressure oil from a discharge pipe 4a of the hydraulic pump 42 to the lift cylinder 34, a lifting operation control valve 44 that connects or blocks the flow of the first pressure oil supply passage 4b, a pressure oil return passage 4c that branches off from between the lifting operation control valve 44 and the hydraulic pump 42 in the first pressure oil supply passage 4b ​​and connects to the oil tank 43, a lowering operation control valve 45 that connects or blocks the flow of the pressure oil return passage 4c, a flow control valve Fv provided downstream of the lowering operation control valve 45, a main relief valve Rm that determines the maximum value of the discharge pressure of the hydraulic pump 42, and a contactor relay CR (FIG. 3) interposed between the electric motor 41 and a battery (not shown). In this embodiment, the lifting operation control valve 44 and the lowering operation control valve 45 constitute a lift cylinder control valve that controls the flow of pressure oil from the hydraulic pump 42 to the lift cylinder 34.

[0026] In response to an operation signal from the first operating device R1, power supply from the battery to the electric motor 41 is controlled via the contactor relay CR, and the hydraulic pump 42 is driven. At the same time, a drive command signal is appropriately input to each solenoid unit 44s, 45s of the control valves 44, 45, so that the supply and discharge of pressure oil from the hydraulic pump 42 is controlled, and the lift cylinder 34 extends and retracts. As the lift cylinder 34 extends and retracts, the load receiving platform 1 is raised and lowered.

[0027] The hydraulic drive unit 4 also includes a second pressure oil supply passage 4d branching off from the discharge pipe 4a of the hydraulic pump 42 and connected to the rod side of the slide cylinder 24, a throttle valve V1 and a check valve Rv provided in the second pressure oil supply passage 4d, a third pressure oil supply passage 4e branching off from the second pressure oil supply passage 4d and connected to the bottom side of the slide cylinder 24, a draw-out operation control valve 46 that opens or closes the flow in the third pressure oil supply passage 4e, a pressure oil return passage 4f branching off from the third pressure oil supply passage 4e downstream of the draw-out operation control valve 46 and connected to the oil tank 43, and a draw-in operation control valve 47 that opens or closes the flow in the pressure oil return passage 4f.

[0028] In response to an operation signal from the first operating device R1, the electric motor 41 and the hydraulic pump 42 are driven via the contactor relay CR, and a drive command signal is input to the solenoid portion 46s of the pull-out operation control valve 46. At this time, since the pull-in operation control valve 47 is in the shutoff position, pressure oil from the hydraulic pump 42 is supplied to the bottom side of the slide cylinder 24 via the third pressure oil supply passage 4e, and the load receiving platform 1 slides backward. On the other hand, in response to an operation signal from the first operating device R1, the electric motor 41 and the hydraulic pump 42 are driven via the contactor relay CR, and a drive command signal is input to the solenoid portion 47s of the pull-in operation control valve 47. At this time, since the pull-out operation control valve 46 is in the shutoff position, pressure oil from the hydraulic pump 42 is supplied to the rod side of the slide cylinder 24 via the second pressure oil supply passage 4d, and pressure oil from the bottom side of the slide cylinder 24 flows out to the oil tank 43 via the pressure oil return passage 4f. As a result, the slide cylinder 24 contracts and the load-receiving platform 1 slides forward.

[0029] In this embodiment, a bypass passage 4g branched off from the discharge pipe 4a and connected to the pressure oil return passage 4f is provided at a position downstream of the main relief valve Rm and upstream of the draw-out operation control valve 46 and the draw-in operation control valve 47. A sub-relief valve Rs and a changeover valve 48 are provided in the bypass passage 4g. The changeover valve 48 opens and closes by a drive signal to a solenoid unit 48s. The relief pressure of the sub-relief valve Rs (e.g., about 6 MPa) is set lower than the relief pressure of the main relief valve Rm (e.g., about 20 MPa). When the changeover valve 48 is switched to the communicating position to connect to the discharge pipe 4a, the maximum value of the pressure oil in the discharge pipe 4a is set to a value lower than the relief pressure of the main relief valve Rm.

[0030] In addition, the discharge pipe 4a is provided with a pressure sensor 54 that detects when the load receiving platform 1 is pressed against the guide rail 21. When the lift cylinder 34 extends and the load receiving platform 1 comes into contact with the guide rail 21, the pressure in the discharge pipe 4a increases. When the pressure sensor 54 detects that this pressure exceeds a predetermined value, it can be determined that the load receiving platform 1 has come into contact with the guide rail 21.

[0031] Although not shown in FIG. 2, as shown in FIG. 3, the platform lifting device 100 is provided with a plurality of sensors in addition to the pressure sensor 54.

[0032] For example, the guide rail 21 is provided with a front end sensor 72, a first drawer position sensor 52, a step position sensor 71, and a rear end sensor 53 as position sensors for detecting the position of the load receiving platform 1 in the front-rear direction.

[0033] The front end sensor 72 is a sensor that detects the slider 22 at the front end position where it abuts against the front stopper, and detects that the load receiving platform 1 is in the storage position. The rear end sensor 53 is a sensor that detects the slider 22 at the rear end position where it abuts against the rear stopper, and detects that the load receiving platform 1 is in the above-mentioned second drawer position (regardless of height). The first drawer position sensor 52 is a sensor that detects that the slider 22 has moved backward beyond an intermediate position set between the front end position and the rear end position, and detects that the load receiving platform 1 is in the first drawer position. The step position sensor 71 is a sensor that detects the slider 22 at a set position (for example, a position set between the intermediate position and the rear end position), and detects that the load receiving platform 1 is in the step use position. These sensors may be proximity sensors, limit switches, etc.

[0034] The "step utilization position" is a position where the loading platform 1 is pulled out backward by a preset amount in order to use the loading platform 1 as a step. In this embodiment, the step utilization position is set to a position forward of the second pull-out position and rearward of the first pull-out position, but the setting of the positional relationship in the front-to-rear direction with the first pull-out position can be changed.

[0035] In addition, a folding sensor 51 (FIG. 3) is provided at the folding hinge of the loading platform 1 to detect the posture (folded state) of the loading platform 1, and the folding sensor 51 detects that the loading platform 1 is in the first lowered position. The folding sensor 51 may be a proximity sensor, a limit switch, an angle sensor, or the like.

[0036] In addition, the vehicle V is equipped with a shift lever 73 (FIG. 3), a handbrake 74 (FIG. 3), a key switch 75 (FIG. 3), a lock sensor 76 (FIG. 3) for detecting the locked or unlocked state of the locking device of the rear door of the cargo box B of the vehicle V, a door sensor 77 (FIG. 3) for detecting the open / closed state of the rear door of the cargo box B, and an obstacle sensor 78 (FIG. 3) for detecting obstacles around the cargo receiving platform 1 (particularly the area where the cargo receiving platform 1 is pulled out at the rear of the vehicle V). At least one of the lock sensor 76, the door sensor 77, and the obstacle sensor 78 may be provided in the cargo receiving platform lifting device 100. The lock sensor 76 and the door sensor 77 may be a proximity sensor, a limit switch, an angle sensor, or the like. The obstacle sensor 78 may be a camera, an infrared sensor, a radar such as LiDAR, or a contact switch, or the like. When a contact switch is used as an obstacle sensor, for example, a thin plate can be attached to the bumper surface of the loading platform 1, and an obstacle can be detected by pressing the contact switch through this plate.

[0037] The signals of the folding sensor 51, the first pull-out position sensor 52, the rear end sensor 53, and the pressure sensor 54 are used when the first operation device R1 is operated to use the cargo receiving platform 1 for loading and unloading cargo. The signals of the step position sensor 71, the front end sensor 72, the shift lever 73, the handbrake 74, the key switch 75, the lock sensor 76, the door sensor 77, and the obstacle sensor 78 are used when the second operation device R2 is operated to use the cargo receiving platform 1 as a step, etc.

[0038] -Control device- FIG. 3 is a functional block diagram of the control device 6 provided in the platform lifting and lowering device 100 shown in FIG.

[0039] The control device 6 is a computer having an operation control function provided in the loading platform lifting device 100, and in this embodiment, includes a first control unit 6A that controls the lift cylinder 34 and the slide cylinder 24 in response to an operation signal from the first operating device R1 to drive the loading platform 1, and a second control unit 6B that controls the slide cylinder 24 in response to an operation signal from the second operating device R2 to drive the loading platform 1. The first control unit 6A and the second control unit 6B are separate boards, and are configured to be turned on and off by individual power switches 6a, 6b.

[0040] The first control unit 6A is connected to the folding sensor 51, the first drawing-out position sensor 52, the rear end sensor 53, and the pressure sensor 54. The first control unit 6A includes an input unit 61A to which signals from these sensors 51 to 54 are input, a receiving unit 62A to which an operation signal from the first operation device R1 to the loading platform lifting device 100 is received, a storage unit (memory) 63A to store a control program (for example, a program in which sequence control, timer control, etc. are described) and a control threshold value, a calculation unit (CPU) 64A to execute calculation processing according to the control program stored in the storage unit 63A and to instruct the operation of each cylinder 24, 34, and an output unit 65A to appropriately output command signals generated by the calculation unit 64A to the solenoid units 44s to 48s of the control valves 44 to 48 and the above-mentioned contactor relay CR.

[0041] The second control unit 6B is connected to a step position sensor 71, a front end sensor 72, a shift lever 73, a side brake 74, a key switch 75, a lock sensor 76, a door sensor 77, and an obstacle sensor 78. The shift lever 73, the side brake 74, the key switch 75, the lock sensor 76, the door sensor 77, and the obstacle sensor 78 are components of the vehicle V. Signals from the shift lever 73, the side brake 74, the key switch 75, the lock sensor 76, the door sensor 77, and the obstacle sensor 78 can be input to the second control unit 6B via a CAN (Controller Area Network) mounted on the vehicle V, or via a signal output terminal if the vehicle V has a signal output terminal.

[0042] A signal corresponding to the lever position output by the potentiometer of the shift lever 73 is input from the shift lever 73 to the second control unit 6B. A signal corresponding to the lever position output by the potentiometer of the side brake 74 is input from the side brake 74 to the second control unit 6B. A signal corresponding to the switching position of the key switch 75 is input from the key switch 75 to the second control unit 6B. A signal corresponding to the locking or unlocking state of the locking device of the door of the cargo box B of the vehicle V is input from the lock sensor 76 to the second control unit 6B. A signal corresponding to the open / closed state of the door of the cargo box B is input from the door sensor 77 to the second control unit 6B. A detection signal of an obstacle around the cargo receiving platform 1 is input from the obstacle sensor 78 to the second control unit 6B. If the second control unit 6B has an obstacle detection function (e.g., an image processing function), the input signal from the obstacle sensor 78 to the second control unit 6B may be, for example, an image or point cloud data output by a camera or a radar.

[0043] The second control unit 6B includes an input unit 61B to which signals from sensors such as the step position sensor 71 and the second operating device R2 are input, a storage unit (memory) 63B that stores a control program (for example, a program describing sequence control, timer control, etc.) and control thresholds, a calculation unit (CPU) 64B that executes calculation processing according to the control program stored in the storage unit 63B and instructs the operation of the slide cylinder 24, and an output unit 65B that appropriately outputs command signals generated by this calculation unit 64B to the solenoid units 46s, 47s of the control valves 46, 47 and the contactor relay CR.

[0044] -Pull-out operation- FIG. 4 is a timing chart for explaining the control of the pull-out operation and pull-in operation of the loading platform 1 by the first control section 6A of the control device 6. In FIG.

[0045] First, the operation of pulling out the loading platform 1 will be described with reference to Fig. 4(a). After the power switch 6a provided in the driver's cab of the vehicle V is turned on, when the operator presses the "down" button of the first operating device R1 (time T1), the first control unit 6A energizes the contactor relay CR to drive the electric motor 41, and excites the solenoid unit 46s to extend the slide cylinder 24. At the same time, the first control unit 6A excites the solenoid unit 47s to open the pull-in operation control valve 47 for a short period of time, thereby suppressing noise generated when the slide cylinder 24 is extended. In the stored position, the loading platform 1 is pressed against the guide rail 21, so that the backward movement (first pull-out operation) of the loading platform 1 is not hindered by friction or the like, a slight pressure release is performed by exciting the solenoid unit 45s. During this first pull-out operation of the receiving platform 1, the first control unit 6A determines whether the receiving platform 1 has reached the first pull-out position based on the signal of the first pull-out position sensor 52. Until the signal of the first pull-out position sensor 52 is off and the receiving platform 1 has reached the first pull-out position, the first control unit 6A moves the receiving platform 1 backward only while the "Down" button is pressed, and stops the backward movement when the "Down" button operation is released.

[0046] Regarding the first lowering operation control, when the first drawer position sensor 52 switches off and the load receiving platform 1 reaches the first drawer position (time T2), the first control unit 6A closes the drawer operation control valve 46 to stop the drawer operation of the load receiving platform 1. Then, the first control unit 6A stops the electric motor 41 and the hydraulic pump 42 and opens the lowering operation control valve 45 to lower the load receiving platform 1. During the first lowering operation, the first control unit 6A determines whether the load receiving platform 1 has been lowered to a predetermined height based on the signal of the folding sensor 51. When the signal of the folding sensor 51 switches off, the first control unit 6A stops the first lowering operation (time T3).

[0047] If the "down" button is pressed when the first lowering operation is stopped, the first control unit 6A transitions to the second pull-out operation, driving the electric motor 41 again and opening the pull-out operation control valve 46 to pull out the loading platform 1. During this second pull-out operation of the loading platform 1, the first control unit 6A determines whether the loading platform 1 has reached the second pull-out position based on the signal of the rear end sensor 53. The first control unit 6A stops the second pull-out operation when the signal of the rear end sensor 53 switches to ON (time T4).

[0048] Then, if the "Down" button is pressed when the second pull-out operation is stopped, the first control unit 6A transitions to the second lowering operation. The first control unit 6A stops the electric motor 41 and the hydraulic pump 42, and opens the lowering operation control valve 45 to lower the loading platform 1 again. The first control unit 6A continues this second lowering operation while an operation signal is being input from the "Down" button, and stops it when the loading platform 1 touches the ground and the worker stops the lowering operation (time T5).

[0049] -Pull-in operation- Next, the retracting operation of the load receiving platform 1 will be described with reference to FIG. 4(b). When performing this retracting operation, the worker manually folds the load receiving platform 1 in a "L" shape in advance at the grounded position. After that, the worker presses the "up" button of the first operating device R1. When the "up" button is pressed and an operation signal for the first lift is input (time T11), the first control unit 6A energizes the contactor relay CR to drive the electric motor 41 and opens the lifting operation control valve 44 to lift the load receiving platform 1 (first lift). At this time, the lifting operation control valve 44 and the pull-out operation control valve 46 are opened, and the load receiving platform 1 is lifted from the grounded position while remaining in the second pull-out position. During the first lifting operation of the load receiving platform 1, the first control unit 6A determines whether the load receiving platform 1 has reached a predetermined height, specifically, whether the angle of the load receiving platform 1 (for example, the hinge portion of the load receiving platform 1) has reached a set angle, based on the signal of the folding sensor 51. The first control unit 6A raises the loading platform 1 only while the "up" button is pressed until the loading platform 1 reaches the above-mentioned predetermined height, and stops the lifting when the operation is released (time T12).

[0050] When the load receiving platform 1 reaches a predetermined height and the folding sensor 51 is switched on, the first control unit 6A closes the lifting operation control valve 44 to stop the first lifting operation of the load receiving platform 1. When the load receiving platform 1 is at a predetermined height and the "up" button is pressed, the first control unit 6A opens the pull-in operation control valve 47 to pull in the load receiving platform 1 while maintaining the load receiving platform 1 at the above-mentioned predetermined height. Preferably, the first control unit 6A opens the pull-in operation control valve 47 and simultaneously opens the pull-out operation control valve 46 for a short time to depressurize the slide cylinder 24 and the lift cylinder 34. During this first pull-in operation, the first control unit 6A determines whether the load receiving platform 1 has reached the first pull-out position based on the signal of the first pull-out position sensor 52. When the signal of the first pull-out position sensor 52 is switched on, the first control unit 6A stops the first pull-in operation (time T13).

[0051] When the "up" button is pressed while the loading platform 1 is in the first drawn-out position, the first control unit 6A transitions to the second lifting operation. When the loading platform 1 reaches the first drawn-out position, the first control unit 6A closes the pull-in operation control valve 47 to stop the loading operation (first pull-in operation) of the loading platform 1, and switches the switching valve 48 to the communication position to switch the relief pressure to the low relief pressure by the sub-relief valve Rs. The first control unit 6A then opens the lifting operation control valve 44 to lift the loading platform 1 again while the loading platform 1 is in the first drawn-out position. When starting this second lifting of the loading platform 1, it is not important that the relief pressure is strictly lowered to the relief pressure by the sub-relief valve Rs at the time of resuming the lifting, as long as the sub-relief valve Rs can operate in the circuit. During the second lifting operation of the loading platform 1, the first control unit 6A determines whether the loading platform 1 has reached an appropriate height based on the signal from the pressure sensor 54. When the signal of the pressure sensor 54 is switched to ON, the first control unit 6A stops the second lifting operation (time T14). During this second lifting operation, the relief pressure of the hydraulic circuit is lowered to a low relief pressure by the sub-relief valve Rs, thereby preventing the pressing force acting between the loading platform 1 and the guide rail 21 from becoming excessive.

[0052] Then, when the loading platform 1 reaches the storage height and the signal of the pressure sensor 54 switches to ON, the first control unit 6A proceeds to the second pulling-in operation. A detection signal is input from the pressure sensor 54 by the second lifting operation, and the first control unit 6A recognizes that the loading platform 1 has reached the height of the storage position by recognizing that this detection signal is a contact pressure equal to or greater than a predetermined pressure (e.g., 40 MPa). Upon proceeding to the second pulling-in operation, the first control unit 6A closes the lifting operation control valve 44 to stop the lifting operation of the loading platform 1, and, triggered by the loading platform 1 contacting the guide rail 21, causes the loading platform 1 to be pulled in while being held at the storage height.

[0053] This second pull-in operation is an operation automatically commanded by the first control unit 6A when the second lifting operation is completed (when it is recognized that the loading platform 1 has come into contact with the guide rail 21). When the signal of the pressure sensor 54 is switched on (time T14), the first control unit 6A opens the pull-in operation control valve 47 to pull in the loading platform 1 regardless of whether the first operating device R1 is operated or not. At this time, the first control unit 6A closes the switching valve 48 with a slight delay (for example, 500 ms) from the time when the pull-in operation control valve 47 is opened, and returns the relief pressure of the hydraulic circuit to the relief pressure by the main relief valve Rm. This is to weaken the contact pressure of the loading platform 1 against the guide rail 21 at the start of the second pull-in operation. After the loading platform 1 is thus pulled in to the storage position, the first control unit 6A stops the electric motor 41 and the hydraulic pump 42 (time T15), determines whether the power switch 6a has been turned off, confirms that the power is off, and ends the loading operation.

[0054] -Step use- In this embodiment, in addition to the above-mentioned pull-out and pull-in operations for placing cargo on the cargo receiving platform 1 for loading and unloading, the cargo receiving platform 1 is stopped at a step utilization position set midway between the storage position and the second pull-out position in the forward / rearward direction, and the slightly pulled-out cargo receiving platform 1 can be used as a step by which an operator can place his / her feet and move between the cargo box and the ground.

[0055] The operation of the receiving platform lifting device 100 when it is used as a step will be described with reference to Fig. 5. In Fig. 5, the second operating device R2 used when the receiving platform lifting device 100 is used as a step is also shown, and the buttons of the second operating device R2 pressed for each operation are shown in black.

[0056] The load-receiving platform 1 in the storage position shown in FIG. 5(a) is below the load box B and does not protrude beyond the rear end of the load box B, similarly to FIG. 1(a).

[0057] When the worker presses the "Out" button (the button on the right side in the figure) of the second operating device R2 as shown in Fig. 5(b) in order to use the loading platform 1 as a step, the second control unit 6B of the control device 6 moves the loading platform 1 backward along the arrow A11 to the step usage position, which is a distance L11 (approximately 150 mm) rearward from the rear end of the box B. At this time, the loading platform 1 slides from the stored position to the step usage position without changing its posture or height (slight changes due to hydraulic oil leaks, manufacturing errors, etc. are allowed). In other words, the loading platform 1 translates backward from the stored position to the step usage position while remaining in a folded state.

[0058] When the loading platform 1 is pulled out to the step utilization position, the second control unit 6B will not move the loading platform 1 backward beyond the step utilization position even if the "Exit" button is pressed, as shown in Figure 5(c), but will hold the loading platform 1 in the step utilization position.

[0059] 5(d), when the "ON" button (the button on the left side in the figure) is pressed, the second control unit 6B slides the load receiving platform 1 from the step using position to the storage position without changing its posture and height (slight changes due to leaks of pressure oil, manufacturing errors, etc. are allowed). In other words, the load receiving platform 1 translates forward from the step using position to the storage position while remaining in the folded state.

[0060] Regarding the operation of the loading platform lifting device 100 when using the above-mentioned loading platform 1 as a step, it is not necessary to drive the lift cylinder 34 and it is sufficient to drive only the slide cylinder 24; however, it is also possible to drive the lift cylinder 34 to return the height of the loading platform 1 to its original state when, for example, the loading platform 1 drops due to a decrease in the holding pressure of the lift cylinder 34 when the loading platform 1 is pulled out or when an operator places his / her foot on it.

[0061] -Control procedure- FIG. 6 is a flow chart showing a control procedure of the loading platform lifting and lowering device by the second control section 6B of the control device 6. In FIG.

[0062] When using the loading platform 1 as a step, the worker turns on the power switch 6b of the second control unit 6B and operates the second operating device R2 to pull out the loading platform 1 backward by a predetermined distance (distance L11). An operating signal of the second operating device R2 is input to the second control unit 6B via the input unit 61B.

[0063] When the power switch 6b is turned on, the second control unit 6B starts the flow of FIG. 6 and judges whether the "out" button or the "in" button of the second operating device R2 is pressed (steps S1 and S2). If the "out" button is pressed, the second control unit 6B outputs a command signal for one control cycle, extends the slide cylinder 24 by a small stroke, and pulls out the loading platform 1 (step S3). If the "in" button is pressed, the second control unit 6B outputs a command signal for one control cycle, contracts the slide cylinder 24 by a small stroke, and pulls in the loading platform 1, and returns the procedure to step S1 (step S4). After moving the loading platform 1 backward, the second control unit 6B judges whether the step position sensor 71 is on (step S5). If the step position sensor 71 is off, the second control unit 6B returns the procedure to step S1. Furthermore, if neither the "Exit" button nor the "In" button has been pressed, the second control unit 6B determines whether a first preparation signal (hereinafter referred to as the "travel preparation signal"), which is a predetermined input signal regarding preparation for traveling of the vehicle V, has been input (steps S8 to S12), and if the travel preparation signal has not been input, the procedure returns to step S1.

[0064] By repeatedly executing the above steps S1 to S12, the second control unit 6B moves the receiving platform 1 back and forth in response to the operation of the "out" button and the "in" button when the receiving platform 1 has not yet reached the step utilization position and is located forward of the step utilization position.

[0065] When the receiving platform 1 reaches the step use position by the pull-out operation in step S3 and the step position sensor 71 turns on, the second control unit 6B restricts the pull-out operation of the receiving platform 1 (step S6) to prevent the receiving platform 1 from moving backward beyond the step use position. Even if the "out" button is operated while the receiving platform 1 is in the step use position, the second control unit 6B does not output a command signal to extend the slide cylinder 24 and holds the receiving platform 1 at the step use position (step S7). Furthermore, when the "out" button is not pressed in steps S1 and S7, the second control unit 6B determines whether the "in" button has been operated (step S2), and if the "in" button has been pressed, the second control unit 6B contracts the slide cylinder 24 by a small stroke and returns the procedure to step S1 (step S4).

[0066] In this embodiment, the second control unit 6B has an automatic control function (first automatic control and second automatic control) that automatically drives the slide cylinder 24 to move the loading platform 1 to a predetermined position when a preparation signal, which is a predetermined input signal, is input. The first automatic control is a control that automatically stores the loading platform 1 in a storage position in response to a travel preparation signal when the loading platform 1 is not completely retracted to the storage position when the vehicle V is driven after a loading operation using the loading platform 1. The second automatic control is a control that automatically draws the loading platform 1 to a predetermined position (in this embodiment, a step use position) in response to a second preparation signal (hereinafter, referred to as a loading / unloading preparation signal), which is a predetermined input signal related to preparation for loading / unloading of luggage from the loading box B of the vehicle V, before starting a loading operation using the loading platform 1.

[0067] The determinations in steps S8 to S12 above are processes for determining whether or not to execute the first automatic control. The order of the determinations in steps S8 to S12 can be changed.

[0068] In step S8, the second control unit 6B determines whether the signal of the front end sensor 72 is on. If the loading platform 1 is in the storage position and the signal of the front end sensor 72 is on, there is no need to execute the first automatic control. If the loading platform 1 is in the storage position and the signal of the front end sensor 72 is on, the second control unit 6B moves the procedure to step S15 to determine whether or not to execute the second automatic control. If the loading platform 1 is not in the storage position and the signal of the front end sensor 72 is off, the second control unit 6B moves the procedure to step S9 to continue the determination of whether or not to execute the first automatic control.

[0069] In step S9, the second control unit 6B inputs a signal corresponding to the lever position output by the shift lever 73 as a travel preparation signal, and determines whether the shift lever 73 is in a lever position other than the parking position and the neutral position (such as a drive position) based on this signal. In order to travel the vehicle V, it is necessary to switch the shift lever 73 to a position other than the parking position and the neutral position. If the shift lever 73 is in a lever position other than the parking position and the neutral position, the second control unit 6B proceeds to step S13 and executes the first automatic control (automatic storage). If the shift lever 73 is in the parking position or the neutral position, the second control unit 6B proceeds to step S10 and continues to determine whether to execute the first automatic control.

[0070] In step S10, the second control unit 6B inputs a signal corresponding to the lever position output by the side brake 74 as a travel preparation signal, and determines whether the side brake 74 is released (whether the signal from the side brake 74 is a release signal) based on this signal. In order to drive the vehicle V, it is necessary to release the side brake 74. If the side brake 74 is released, the second control unit 6B moves the procedure to step S13 and executes the first automatic control (automatic storage). If the side brake 74 is not released, the second control unit 6B moves the procedure to step S11 and continues to determine whether or not to execute the first automatic control.

[0071] In step S11, the second control unit 6B inputs a signal according to the position output by the key switch 75 as a travel preparation signal, and determines whether the key switch 75 is on (whether the signal from the key switch 75 is a key-on signal) based on this signal. In order to travel the vehicle V, the key switch 75 must be turned on. If the key switch 75 is on, the second control unit 6B proceeds to step S13 and executes the first automatic control (automatic storage). If the key switch 75 is off, the second control unit 6B proceeds to step S12 and continues to determine whether or not to execute the first automatic control.

[0072] In step S12, the second control unit 6B inputs a power-off signal of the power switch 6a of the first control unit 6A as a travel preparation signal, and judges whether the first control unit 6A is in a power-off state based on the presence or absence of the power-off signal. The power-off signal may be a signal input from the first control unit 6A to the second control unit 6B in association with power-off, or may be a signal interruption from the first control unit 6A (that is, the second control unit 6B may be configured to detect the interruption of the electrical connection with the first control unit 6A). The power switch 6a of the first control unit 6A may be operated, for example, when completing a loading operation using the loading platform 1 and running the vehicle V. If the power switch 6a of the first control unit 6A is off, the second control unit 6B moves the procedure to step S13 and executes the first automatic control (automatic storage). If the power switch 6a of the first control unit 6A is on, the second control unit 6B finishes the judgment of whether to execute the first automatic control and returns the procedure to step S1.

[0073] If, through the judgments of steps S8 to S12, the second operating device R2 is not operated, the processing of step S8 judges that the loading platform 1 is not in the storage position, and the input of a travel preparation signal is recognized in any of the processing of steps S9 to S12, the second control unit 6B executes the first automatic control (automatic storage). The first automatic control is executed until the front end sensor 72 is turned on, regardless of the operation signal of the second operating device R2 (regardless of the presence or absence of an operation signal). In other words, during the execution of the first automatic control, the second control unit 6B does not respond to the operation of the "out" button and "in" button of the second operating device R2 (and of course, the operation of the first operating device R1), but judges only whether the front end sensor 72 is turned on (step S14), and when the loading platform 1 reaches the storage position and the front end sensor 72 is turned on, the first automatic control is stopped and the flow of FIG. 6 is ended.

[0074] Furthermore, if the front end sensor 72 is on in the process of the previous step S8, the second control unit 6B judges whether or not a loading / unloading preparation signal has been input (steps S15 to S17), and if the loading / unloading preparation signal has not been input, returns the procedure to step S1. The judgments in steps S15 to S17 are processes for judging whether or not to execute the second automatic control. The order of judgments in steps S15 to S17 can be changed.

[0075] In step S15, the second control unit 6B inputs the signal of the lock sensor 76 as a loading / unloading preparation signal, and judges whether the signal of the lock sensor 76 has changed from on to off. When stopping the vehicle V and starting the loading / unloading operation of the luggage, it is necessary to release the locking device of the door of the cargo box B and open the door. When the signal of the lock sensor 76 has changed from on to off as the locking device of the door of the cargo box B has changed from a locked state to an unlocked state, the second control unit 6B moves the procedure to step S18. When the signal of the lock sensor 76 is on, or when the signal of the lock sensor 76 has continued to be off from the previous control cycle, the second control unit 6B moves the procedure to step S16 and continues judging whether or not to execute the second automatic control.

[0076] In step S16, the second control unit 6B inputs the signal of the door sensor 77 as a loading / unloading preparation signal, and judges whether the signal of the door sensor 77 has changed from off to on. The loading / unloading preparation signal judged to be input in step S16 is a signal that detects that the door of the cargo box B has changed from a closed state to an open state, or a signal that detects that the door of the cargo box B has reached a predetermined opening degree. When the vehicle V is stopped and the loading / unloading operation of the luggage is started, it is necessary to open the door of the cargo box B. In step S16, based on the signal of the door sensor 77, it is judged whether the door has changed from a closed state to an open state, or has reached a predetermined opening degree. Examples of the predetermined opening degree include 90° or 270° (a state in which the door extends backward or forward). When the signal of the door sensor 77 has changed from off to on in association with the opening operation of the door of the cargo box B, the second control unit 6B moves the procedure to step S18. If the signal of the door sensor 77 is off, or if the signal of the door sensor 77 continues to be on from the previous control cycle, the second control unit 6B proceeds to step S17 and continues to determine whether or not to execute the second automatic control.

[0077] In step S17, the second control unit 6B inputs a power-on signal of the power switch 6a of the first control unit 6A as a loading / unloading preparation signal, and judges whether the power of the first control unit 6A has changed from off to on. The power-on signal judged to be input in step S17 is a signal input from the first control unit 6A to the second control unit 6B with the start of the first control unit 6A. When the vehicle V is stopped and the loading / unloading work of the luggage is started, it is necessary to turn on the power of the first control unit 6A. In step S17, based on the signal of the power switch 6a of the first control unit 6A, it is judged whether the first control unit 6A has shifted from a power-off state to a power-on state. When the first control unit 6A has shifted from a power-off state to a power-on state, the second control unit 6B moves the procedure to step S18. When the first control unit 6A is power-off, or when the first control unit 6A is continuously on from the previous control cycle, the second control unit 6B finishes the judgment of whether to execute the second automatic control and returns the procedure to step S1.

[0078] When the procedure proceeds to step S18 after any of steps S15 to S17, the second control unit 6B judges whether there is an obstacle around the loading platform 1 based on the signal of the obstacle sensor 78. If an obstacle is detected around the loading platform 1, the second control unit 6B prohibits the second automatic control and returns the procedure to step S1 without executing the automatic drawing of the loading platform 1. If, after the judgment of steps S15 to S18, the second operation device R2 is not operated, the input of the loading / unloading preparation signal is recognized in any of the processes of steps S15 to S17, and no obstacle is detected around the loading platform 1, the second control unit 6B executes the second automatic control (automatic drawing) (step S19). The second automatic control is executed until it is detected that the loading platform 1 is at a set position a predetermined distance behind the storage position, regardless of the operation signal of the second operation device R2 (regardless of the presence or absence of the operation signal). In this embodiment, the set position is the step use position. In other words, while the second automatic control is being executed, the second control unit 6B does not respond to the operation of the "out" and "in" buttons of the second operating device R2 (and of course the operation of the first operating device R1), but only determines whether the step position sensor 71 has been turned on (step S20), and when the loading platform 1 reaches the step utilization position and the step position sensor 71 has been turned on, the second automatic control is stopped and the flow of FIG. 6 is ended.

[0079] Although not mentioned in the flowchart of FIG. 6, the above-mentioned control for depressurization and suppression of abnormal noise can be applied to the control by the second control unit 6B as well as the control by the first control unit 6A (FIG. 4).

[0080] -effect- (1) In this embodiment, when a predetermined preparation signal is input, the cargo receiving platform 1 automatically moves to a predetermined position in response to the preparation signal. For example, when the vehicle V is driven after the loading / unloading operation, even if the cargo receiving platform 1 is pulled out from the storage position, if a travel preparation signal is input to the control device 6 in preparation for traveling, the cargo receiving platform 1 is automatically stored. In addition, when the vehicle V arrives at the destination and starts the loading / unloading operation, if a loading / unloading preparation signal is input to the control device 6 in preparation for unloading the cargo, the cargo receiving platform 1 is automatically pulled out to a predetermined position (for example, a step use position). Therefore, the worker can store the cargo receiving platform 1 or use it as a step by following a predetermined procedure without having to operate the second operation R2 each time. In this way, according to this embodiment, the cargo receiving platform 1 can be automatically moved to a predetermined position under specified conditions to make the worker's actions more efficient. In addition, when moving to the step use position, a step can be used to support movement to the loading platform floor surface, which is a high position, which also ensures the safety of the worker.

[0081] (2) Furthermore, according to the first automatic control, if the worker attempts to drive the vehicle V by mistake without realizing that the loading platform 1 has not been returned to the storage position after pulling out the loading platform 1 and using it as a step, the loading platform 1 is automatically stored in response to a travel preparation signal input to the control device 6 during the process of driving the vehicle V. This makes it possible to prevent the vehicle V from driving in a state in which the loading platform 1 is not stored in the storage position. In particular, in this embodiment in which the loading platform 1 is automatically pulled out to the step utilization position, a situation may arise in which the worker does not realize that the loading platform 1 has not been returned to the storage position because the worker does not directly operate the loading platform 1 to the step utilization position, but the first automatic control can prevent such a situation from occurring, thereby providing a synergistic effect.

[0082] (3) Furthermore, according to the first automatic control, the loading platform 1 can be stored in the storage position while the vehicle is traveling, and the slider 22 can be brought into contact with the front stopper. Therefore, even when the loading platform 1 is used as a rear bumper, the loading platform 1 can perform as designed as a bumper.

[0083] (4) In an underfloor storage type loading platform lifting device, the loading platform is generally configured so that when the loading platform is stored in the storage position, the loading platform engages with and is supported by a fall prevention member, so that the loading platform 1 will not descend even if a hydraulic leak occurs in the cylinder. When the loading platform is not in the storage position, the loading platform may not be properly engaged and supported by the fall prevention member. In contrast, the first automatic control can prevent the vehicle V from traveling when the loading platform 1 is not in the storage position, so that a state in which the fall prevention member does not function properly can be avoided.

[0084] (5) When realizing automatic storage of the loading platform 1, a form (time control) in which the forward movement is performed for a set time based on the time required for the loading platform 1 to move from a predetermined position (the step use position in this embodiment) to the storage position and then terminated may be considered. However, the contraction speed of the slide cylinder 24 may change due to changes in viscosity caused by the temperature of the hydraulic oil, etc., and if the set time is set to the very last moment of the required time, the loading platform 1 may not reach the storage position under some conditions, and also, if the set time is longer than necessary for the required time, it may lead to a waste of power.

[0085] In contrast, the first automatic control of this embodiment is executed without the operation signal corresponding to the operation of the first operating device R1 or the second operating device R2 until it is detected that the loading platform 1 is in the storage position based on the signal of the front end sensor 72. Therefore, the control will not end before the loading platform 1 reaches the storage position, and more power than necessary will not be consumed.

[0086] However, the frequency with which the automatic storage operation is performed and the power required are not great, and it is not necessary to use the front end sensor 72 for control; it is also possible to adopt a configuration in which the time required for the loading platform 1 to move from a specified position to the storage position is set sufficiently taking into account changes in viscosity of the hydraulic oil, and the loading platform 1 is stored using time control.

[0087] (6) According to the second automatic control, the loading platform 1 is automatically pulled out to the step use position in response to a loading / unloading preparation signal input to the control device 6 in the process of starting the loading / unloading work after the vehicle V is stopped. Therefore, the worker can use the loading platform 1 as a step by following a predetermined procedure when starting the loading / unloading work without having to operate the second operation device R2 every time. In particular, with regard to the loading / unloading work of the luggage after the vehicle V is stopped, the worker needs to perform various tasks (operations) before actually starting the loading / unloading work of the luggage, such as operating the door of the cargo box B and moving to pick up and operate the operation devices R1, R2 of the loading platform lifting / lowering device 100. Therefore, the second automatic control according to the present embodiment, which can automatically use the loading platform 1 as a step while omitting the operation of the second operation device R2, is preferable in terms of reducing the burden on the worker (improving the efficiency of actions) and ensuring the safety of the worker.

[0088] In a vehicle V equipped with an underfloor storage type loading platform lifting device 100, it is generally difficult to provide a fixed step because it would interfere with the movement trajectory of the loading platform 1. Therefore, it is useful for the loading platform 1 to be automatically pulled out to the step utilization position when starting loading / unloading work. After the loading platform 1 has been pulled out to the step utilization position, the first operating device R1 can be operated to pull out the loading platform 1 to the rear end position as described in FIG. 4, and the loading platform 1 can be used for loading / unloading work.

[0089] Furthermore, when the cargo receiving platform 1 is used as a step, the fixed step can be omitted. Since a fixed step protrudes rearward from the cargo box and forms the rear end of the vehicle, providing a fixed step increases the overall length of the vehicle. As a result, in order to make the overall length of the vehicle comply with the standards, the overall length of the cargo box must be shortened by the amount that the fixed step protrudes rearward, reducing the volume of the cargo box. In contrast, in a configuration in which the cargo receiving platform 1 can be used as a step as in this embodiment, it is not necessary to provide a fixed step, and therefore the reduction in the volume of the cargo box B can be suppressed.

[0090] (7) In addition, in this embodiment, the second automatic control is prohibited when an obstacle is detected around the loading platform 1. This prevents the loading platform 1 from automatically being pulled out and interfering with the obstacle or coming into strong contact with the obstacle.

[0091] (8) Furthermore, when the loading platform 1 is used as a step, the amount by which the loading platform 1 can be pulled out is restricted and the operation of pulling out the loading platform 1 automatically stops when the loading platform 1 is in the step use position, so the loading platform 1 is not pulled out more than necessary. Of course, the loading platform 1 can also be pulled out to the step use position by operating the "pull out" button. Furthermore, even if the second operating device R2 located forward of the rear end of the cargo box B is used, the loading platform 1 can be pulled out to the step use position without forcing the worker to adjust the amount by which the loading platform 1 protrudes from the rear end of the cargo box B, and there are fewer constraints on the workplace, such as having to stand in a position where the loading platform 1 can be easily seen while in operation.

[0092] -Variations- The present invention is not limited to the above-described embodiment, and may include various modified examples. For example, the above-described embodiment has been described in detail to easily explain the present invention, and is not necessarily limited to an embodiment having all of the configurations described. For example, it is possible to replace a part of the configuration with another configuration. It is also possible to delete a part of the configuration of the embodiment, or to add another configuration.

[0093] For example, in the above embodiment, in the pull-in operation after using the cargo receiving platform 1 for cargo handling work, the second retraction operation after the second lifting operation is an automatic operation, so an example was described in which the first automatic control is applied to a scene after using the cargo receiving platform 1 as a step. However, unlike the above embodiment, the pull-in operation is not performed in the order of the first lifting operation, the first retraction operation, the second lifting operation, and the second retraction operation, but in general, the pull-in operation may be completed with only one lifting operation and one retraction operation. In this case, the retraction operation has a long stroke, so it is not suitable for automation of the retraction operation, and a configuration in which the worker manually advances the cargo receiving platform to the storage position is often adopted. Therefore, there is a possibility that the worker stops the manual operation and runs the vehicle when the retraction operation to the storage position has not been completed. The first automatic control of the above embodiment assumes such a case and can be applied not only to the scene of the step use operation, but also to the pull-in operation of the cargo receiving platform 1 after cargo handling work. For example, when a sequence is applied to the above embodiment in which the storage operation is completed by one lifting operation and one retracting operation, if a sensor capable of detecting a predetermined intermediate position of the load receiving platform 1, such as the first drawer position sensor 52, is installed, it is possible to determine a state in which the load receiving platform 1 is located ahead of the intermediate position but has not yet reached the storage position based on the signals of this sensor and the front end sensor 72. Then, when a travel preparation signal is input in this situation, an automatic storage operation can be executed.

[0094] As for the second automatic control, the loading / unloading preparation signal is used as a trigger to automatically pull out the loading platform 1 to the step use position. However, the predetermined position where the loading platform 1 is pulled out is not limited to the step use position (distance L11 in FIG. 5) defined in this embodiment, but can be a set position a predetermined distance behind the storage position. The setting of this predetermined distance can be changed arbitrarily, and for example, the first pull-out position or the rear end position described above can be set as the set position (that is, the first pull-out position or the rear end position can be set as the step use position). In this case, the signals of the first pull-out position sensor 52 and the rear end sensor 53 are also input to the second control unit 6B, and the second automatic control detects the predetermined position where the loading platform 1 is pulled out based on the signals of the first pull-out position sensor 52 and the rear end sensor 53. Even if the loading platform 1 is pulled out to a large extent, there is no problem in using the loading platform 1 as a step. In addition, since the loading platform 1 is already pulled out to a large extent, the transition to the subsequent loading / unloading operation can be smoother.

[0095] Also, although an example has been described in which the first operating device and the second operating device R2 are used differently depending on the work content, the same operating device may be used for both the operations in Fig. 1 and Fig. 5. In this case, buttons for "out", "in", "up" and "down" may be provided on one operating device, or a button may be shared for the operations of in / out and up / down, and the operation may be switched with a switch button. The layout of the second operating device R2 may also be changed, and the second operating device R2 may also be a remote control type.

[0096] In addition, although the control is assigned to the first control unit 6A and the second control unit 6B for each work content, and the power switches 6a, 6b of the first control unit 6A and the second control unit 6B are configured separately, all the controls can be executed by the same control unit and the power switches can be integrated. In this case, it is sufficient to determine whether the operation is related to the step use of the loading platform 1 or the loading use, and to switch the control content according to the determination result. Regarding the process of determining that the power off of the control device is a travel preparation signal as in step S12 of FIG. 6, it is sufficient to execute delay control when the control device processes its own power off, and to turn off the power after executing the first automatic control.

[0097] In addition, as the travel preparation signal, the example of determining the signal related to the shift lever 73, the signal related to the handbrake 74, the signal related to the key switch 75, and the signal of the power switch 6b of the first control unit 6A has been described, but it is not necessary to determine all of these, and a configuration may be adopted in which at least one of them that is particularly necessary is determined. In addition, other signals that can be inevitably acquired in the process until the vehicle V travels (for example, a signal that detects that the steering wheel is gripped by a pressure sensor installed on the steering wheel) can be adopted as the travel preparation signal, not limited to the signal related to the shift lever 73, the signal related to the handbrake 74, the signal related to the key switch 75, and the signal of the power switch 6b of the first control unit 6A. The same is true for the loading / unloading preparation signal, and any one of the signals of the lock sensor 76, the signal of the door sensor 77, and the signal of the power switch 6b of the first control unit 6A can be adopted as the loading / unloading preparation signal, or other signals that can be inevitably acquired in the process of starting the loading / unloading work of the luggage after the vehicle V is stopped can be adopted as the loading / unloading preparation signal.

[0098] In addition, the present invention has been described as being applied to a retractable loading platform lifting device in which the loading platform 1 is pulled out to the rear of the vehicle V for loading and unloading operations, but the same effects can be obtained by applying the present invention to a retractable loading platform lifting device in which the loading platform is pulled out to the left or right side of the vehicle V for loading and unloading operations. [Explanation of symbols]

[0099] 1...load receiving platform, 6...control device, 6a, 6b...power switch, 6A...first control unit, 6B...second control unit, 21...guide rail, 22...slider, 24...slide cylinder, 32...lift arm (arm), 33...compression arm (arm), 34...lift cylinder, 52...first pull-out position sensor (position sensor), 53...rear end sensor (position sensor), 71...step position sensor (position sensor), 72...front end sensor, 73...shift lever, 74...side brake, 75...key switch, 76...lock sensor, 77...door sensor, 78...obstacle sensor, 100...retractable load receiving platform lifting device, B...packing box (loading platform), C...vehicle frame, R1...first operating device, R2...second operating device (operating device), vehicle V

Claims

1. In a retractable loading platform lifting device, a loading platform stored under a vehicle frame is pulled out and raised / lowered, A guide rail extending forward and backward is provided on a lower portion of the vehicle frame; A slider that moves along the guide rail; a slide cylinder for moving the slider; an arm that connects the loading platform to the slider so that the loading platform can be raised and lowered; A lift cylinder for raising and lowering the loading platform; A control device for controlling the slide cylinder, The control device includes: When a preparation signal, which is a predetermined input signal, is input, an automatic control can be executed to automatically drive the slide cylinder and move the loading platform to a predetermined position. A retractable loading platform lifting device.

2. 2. The retractable loading platform lifting device according to claim 1, The preparation signal is a predetermined input signal related to preparation for traveling of the vehicle, The predetermined position is the storage position of the loading platform. A retractable loading platform lifting device.

3. 3. The retractable loading platform lifting device according to claim 2, a front end sensor for detecting when the loading platform is in the stowed position; An operation device that outputs an operation signal to operate the slide cylinder, The control device executes the automatic control without relying on the operation signal until it is detected that the loading platform is in the storage position based on a signal from the front end sensor. A retractable loading platform lifting device.

4. The retractable loading platform lifting device according to claim 2 or 3, A retractable load-receiving platform lifting device, characterized in that the preparation signal is a signal corresponding to the lever position of the vehicle's shift lever, and is a signal that detects that the shift lever is in a lever position other than the parking position or the neutral position.

5. The retractable loading platform lifting device according to claim 2 or 3, A retractable loading platform lifting device, wherein the preparation signal is a signal for releasing a parking brake of the vehicle.

6. The retractable loading platform lifting device according to claim 2 or 3, The retractable loading platform lifting device according to claim 1, wherein the preparation signal is a power-off signal for a power switch of the control device.

7. 7. The retractable loading platform lifting device of claim 6, A first operating device for cargo handling work that raises and lowers the cargo receiving platform; A second operating device for operating only the pull-out and pull-in of the loading platform, The control device includes a first control unit that drives the load receiving platform in response to an operation signal from the first operating device, and a second control unit that drives the load receiving platform in response to an operation signal from the second operating device, The first control unit and the second control unit are configured to be turned on and off by individual power switches, The automatic control is executed by the second control unit while the power supply to the first control unit is turned off. A retractable loading platform lifting device.

8. 3. The retractable loading platform lifting device according to claim 2, 13. A retractable loading platform lifting device, wherein the preparation signal is a key-on signal of a key switch of the vehicle.

9. 2. The retractable loading platform lifting device according to claim 1, the preparation signal is a predetermined input signal related to preparation for loading / unloading luggage onto / from the loading platform of the vehicle; The predetermined position is a set position a predetermined distance behind the storage position of the loading platform. A retractable loading platform lifting device.

10. 10. The retractable platform lifting device of claim 9, a position sensor for detecting that the loading platform is in the set position; An operation device that outputs an operation signal to operate the slide cylinder, The control device executes the automatic control without relying on the operation signal until it is detected that the loading platform is in the set position based on a signal from the position sensor. A retractable loading platform lifting device.

11. The retractable loading platform lifting device according to claim 9 or 10, A retractable loading platform lifting device characterized in that the preparation signal is a signal corresponding to the locked or unlocked state of the locking device of the loading platform door of the vehicle, and is a signal that detects that the locking device has transitioned from a locked state to an unlocked state.

12. The retractable loading platform lifting device according to claim 9 or 10, The preparation signal is a signal corresponding to the open / closed state of the loading platform door of the vehicle, and is a signal detecting that the loading platform door has transitioned from a closed state to an open state, or a signal detecting that the loading platform door has reached a predetermined opening degree.

13. The retractable loading platform lifting device according to claim 9 or 10, 13. A retractable loading platform lifting device, wherein the preparation signal is a power-on signal for a power switch of the control device.

14. 14. The retractable platform lifting device of claim 13, A first operating device for cargo handling work that raises and lowers the cargo receiving platform; A second operating device for operating only the pull-out and pull-in of the loading platform, The control device includes: A first control unit that drives the loading platform in response to an operation signal from the first operating device; a second control unit that drives the loading platform in response to an operation signal from the second operating device, The first control unit and the second control unit are configured to be turned on and off by individual power switches, The power-on signal is input from the first control unit to the second control unit in response to activation of the first control unit, The automatic control is executed by the second control unit. A retractable loading platform lifting device.

15. The retractable loading platform lifting device according to claim 9 or 10, The retractable loading platform lifting device is characterized in that the control device prohibits the automatic control when an obstacle is detected around the loading platform.

16. A vehicle equipped with the retractable loading platform lifting device according to claim 1.

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