Loading platform lifting device

Abstract

To provide a cargo platform lifting device that can inhibit decline of the workability in performing work of moving cargo between a cargo platform and a floor of a cargo box.SOLUTION: A cargo platform lifting device 10 comprises: a cargo platform 11 on which cargo is placed to cause the cargo to be loaded into and unloaded from a cargo box 3 mounted on a vehicle body 2; a lifting mechanism 12 for raising and lowering the cargo platform 11 between a raised position T1 at the same height as a floor 3a of the cargo box 3 and a lowered position T2 in contact with the ground; a first detection unit 41 for detecting that the lift position of the cargo platform 11 is the raised position T1; a reporting unit 51 for reporting to an operator that the cargo platform 11 is at the raised position T1; and a control unit 52 that causes the reporting unit 51 to report while a detection signal is input from the first detection unit 41.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a loading platform lifting device.

Background Art

[0002] As a loading platform lifting device mounted on a truck or the like and used for loading and unloading goods, there is, for example, one described in Patent Document 1. The loading platform lifting device of Patent Document 1 includes a loading platform disposed behind the loading box of the truck, and a lifting mechanism that raises and lowers the loading platform between a lowered position and a raised position. The loading platform is grounded on the ground at the lowered position and is at the same height as the floor surface of the loading box at the raised position.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] After an operator raises the loading platform to the raised position by the lifting mechanism, the operator may perform a moving operation of moving a cart loaded with goods between the loading platform and the floor surface of the loading box. However, if this moving operation is performed when the loading platform is at a position slightly lower than the raised position, the cart cannot be smoothly moved between the loading platform and the floor surface of the loading box, and the workability deteriorates.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a loading platform lifting device capable of suppressing deterioration of workability when moving goods between the loading platform and the floor surface of the loading box.

Means for Solving the Problems

[0006] (1) The present invention is for loading and unloading goods with respect to a loading box mounted on a vehicle body, and the goods are placed onHaving a mounting surface Loading platform and While the aforementioned mounting surface maintains a horizontal position, A lifting mechanism that raises the loading platform between a raised position at the same height as the floor of the loading box and a lowered position where it touches the ground, and a first detection unit that detects when the loading platform is in the raised position. A second detection unit detects that the mounting surface is in a horizontal position, A notification unit that informs the worker that the loading platform is in the raised position, and a detection signal from the first detection unit and the detection signal of the second detection unit but both A loading platform lifting device comprising a control unit that causes the notification unit to notify while input is being received.

[0008] (2) The loading platform lifting device of (1) above teeth A lifting machine that raises and rotates the load-receiving platform between an upright position and a lowered position when the load-receiving platform is in the raised position. Structure Furthermore, The second detection unit detects that the tilted position of the loading platform is the fallen position and that the aforementioned surface is in a horizontal position. It is preferable to do so. In this case, the control unit will notify the system via the notification unit when the loading platform is in the raised position and in a reclined position. Therefore, if the loading platform is in the raised position but in an upright position, the notification unit will not notify the system. This reduces power consumption when the loading platform is in an upright position.

[0009] (3) In the loading platform lifting device of (1) or (2) above, The lifting mechanism comprises an upper arm and a lower arm positioned below the upper arm, and the first detection unit detects the upper arm or the lower arm when the load receiving platform rises to the raised position. It is preferable to do so. (4) Any of (1) to (3) above In the loading platform lifting device, it is preferable that the notification unit is provided inside the loading box. In this case, even if the worker is working inside the cargo box, they can easily see that the loading platform is in the raised position. [Effects of the Invention]

[0010] According to the present invention, it is possible to suppress a decrease in work efficiency when moving cargo between the loading platform and the floor of the cargo box. [Brief explanation of the drawing]

[0011] [Figure 1] This is a side view of a freight vehicle equipped with a loading platform lifting device according to an embodiment of the present invention. [Figure 2] It is an enlarged side view of the load receiving platform lifting device. [Figure 3] It is a plan view of the load receiving platform lifting device. [Figure 4] It is a side view showing the lifting mechanism disassembled. [Figure 5] It is an enlarged side view showing the vicinity of the base of the load receiving platform. [Figure 6] It is a perspective view seen from the rear inside the load box when the load receiving platform is in the raised position. [Figure 7] It is a block diagram showing the control configuration of the load receiving platform lifting device. [Figure 8] It is a flowchart showing a control example of the notification unit executed by the control unit.

Embodiments for Carrying out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a cargo vehicle 1 provided with a load receiving platform lifting device 10 according to an embodiment of the present invention. The cargo vehicle 1 includes a vehicle body 2, a load box 3 mounted on the vehicle body 2, and an opening / closing door 4 that can open and close the rear opening of the load box 3. An operator can load and unload goods from the rear opening of the load box 3 by opening the opening / closing door 4. A so-called upright storage type load receiving platform lifting device 10 is provided at the rear of the vehicle body 2.

[0013] [Load Receiving Platform Lifting Device] FIG. 2 is an enlarged side view of the load receiving platform lifting device 10. FIG. 3 is a plan view of the load receiving platform lifting device 10. In FIGS. 2 and 3, the load receiving platform lifting device 10 includes a load receiving platform 11, a lifting mechanism 12 for lifting and lowering the load receiving platform 11, a tilting mechanism 13 for tilting and rotating the load receiving platform 11, and a support portion 14.

[0014] The support section 14 has a pair of left and right fixed frames 15 and a cross member 16. The left and right fixed frames 15 are each fixed to the vehicle body 2 via brackets 17. The cross member 16 is made of a square pipe material that extends in the vehicle width direction (left and right direction) below the vehicle body 2. The cross member 16 is fixed to the left and right fixed frames 15.

[0015] The front ends of the bumper arms 6 that extend in the front-rear direction are fixed to the left and right fixed frames 15, respectively. The middle portions in the front-rear direction of these pair of bumper arms 6 are fixed to the vehicle body 2 via brackets 7. A rear bumper 8 that extends in the vehicle width direction is fixed to the rear ends of the pair of bumper arms 6.

[0016] FIG. 4 is a side view showing the lifting mechanism 12 disassembled. In FIGS. 2 to 4, the lifting mechanism 12 has an auxiliary link 21, an upper arm 22, a lower arm 23, a connecting link 24, and a lift cylinder 25. A pair of these constituent members 21 to 25 are provided on the outer side in the vehicle width direction of the vehicle body 2, respectively.

[0017] The upper end of the auxiliary link 21 is connected to a bracket 26 fixed to the fixed frame 15 so as to be rotatable about a horizontal axis P1. During the lifting and lowering of the load receiving platform 11, the weight of the load receiving platform 11 and the like constantly acts on the auxiliary link 21, so that the auxiliary link 21 is held in a state of abutting against the fixed frame 15 (the state shown in FIG. 2). Thereby, the parallel link (described later) formed by the upper arm 22 and the lower arm 23 is maintained.

[0018] One end of the upper arm 22 is connected to the upper portion of the auxiliary link 21 so as to be rotatable about a horizontal axis P2 located below the horizontal axis P1. The other end of the upper arm 22 is connected to the upper portion of the connecting link 24 so as to be rotatable about a horizontal axis P3. The other ends of the left and right upper arms 22 are connected by a connecting member 27 that extends in the vehicle width direction. The connecting member 27 is made of, for example, a round pipe material.

[0019] The lower arm 23 is positioned below the upper arm 22 in a side view and further outward in the vehicle width direction than the upper arm 22 in a top view. One end of the lower arm 23 is rotatably connected to a bracket 28 fixed to the fixed frame 15 around a horizontal axis P4. The other end of the lower arm 23 is rotatably connected to the lower part of the connecting link 24 around a horizontal axis P5. The upper arm 22 and the lower arm 23 form a parallel link where the rectangle connecting the four horizontal axes P2 to P5 is a parallelogram.

[0020] The lift cylinder 25 consists of, for example, a single-acting hydraulic cylinder. The tip of the lift cylinder 25 is rotatably connected to the lower part of the auxiliary link 21 around the horizontal axis P6. The base end of the lift cylinder 25 is rotatably connected to the other end of the upper arm 22 around the horizontal axis P7. The lift cylinder 25 applies torque to the upper arm 22 by extending and retracting.

[0021] The base 11b of the loading platform 11 is connected to the upper part of the connecting link 24 so as to be rotatable around the horizontal axis P3. The loading platform 11 has a loading surface 11a on which cargo to be loaded and unloaded from the cargo box 3, or a trolley or the like used to transport the cargo, is placed.

[0022] A luffing mechanism 13 is provided on the underside of the loading surface 11a of the loading platform 11. The luffing mechanism 13 includes a luffing cylinder 31, which is, for example, a single-acting hydraulic cylinder. The base end of the luffing cylinder 31 is connected to the underside of the loading platform 11, and the tip of the luffing cylinder 31 is connected to a connecting link 24. The luffing cylinder 31 applies torque to the loading platform 11 by extending and retracting.

[0023] With the above configuration, when the lift cylinder 25 is extended or retracted, the upper arm 22 and lower arm 23 rotate up and down while maintaining their parallel links. Specifically, when the lift cylinder 25 is extended, the upper arm 22 and lower arm 23 rotate upward around the horizontal axes P2 and P4, respectively. When the lift cylinder 25 is retracted, the upper arm 22 and lower arm 23 rotate downward around the horizontal axes P2 and P4, respectively. As a result, as shown in Figure 1, the loading platform 11 moves up and down between the raised position T1 and the lowered position T2 while maintaining a horizontal posture with the loading surface 11a horizontal.

[0024] When the loading platform 11 lowers to the lowered position T2 while remaining in a horizontal position, the base 11b of the loading platform 11 touches the ground. From this grounded state, when the lift cylinder 25 further contracts, the auxiliary link 21 rotates slightly counterclockwise around the horizontal axis P1 as shown in Figure 2. As a result, the parallel links of the upper arm 22 and the lower arm 23 are disrupted, and the loading platform 11 assumes an inclined position T3, tilted downwards towards the rear, as shown in Figure 1. This allows the worker to smoothly move a trolley or the like between the ground and the loading surface 11a of the loading platform 11.

[0025] When the loading platform 11 is raised to the raised position T1 while remaining in a horizontal position, the mounting surface 11a of the loading platform 11 becomes the same height as the floor surface 3a of the cargo box 3. This allows the worker to smoothly move a trolley or the like between the floor surface 3a of the cargo box 3 and the mounting surface 11a of the loading platform 11.

[0026] In Figures 1 and 2, when the loading platform 11 is in the raised position T1, the loading platform 11 rotates up and down when the luffing cylinder 31 is extended or retracted. Specifically, when the luffing cylinder 31 is extended, the loading platform 11 rotates upright around the horizontal axis P3. When the luffing cylinder 31 is retracted, the loading platform 11 rotates down around the horizontal axis P3.

[0027] The loading platform 11 rotates between a reclined position T4, which is the raised position T1, and an upright position T5, where the loading surface 11a is approximately vertical. Therefore, after the loading and unloading of cargo is completed, the operator can close the opening / closing door 4 and return the loading platform 11 to the upright position T5, allowing the cargo truck 1 to drive.

[0028] [First detection unit] In Figures 2 and 3, the loading platform lifting device 10 further includes a first detection unit 41 that detects when the loading platform 11 is in the raised position T1 (see Figure 1). The first detection unit 41 is attached to the reinforcing beam 3b of the loading box 3 via horizontal stays 42 and vertical stays 45. The reinforcing beam 3b is positioned below the rear of the floor surface 3a, extending in the vehicle width direction. The reinforcing beam 3b is made of, for example, a U-shaped channel material.

[0029] The horizontal stay 42 is made of an L-shaped angle material extending in the front-rear direction. The horizontal stay 42 is attached to the reinforcing girder 3b above the lower arm 23 which is located on one side in the left-right direction (left side in Figure 3). The horizontal stay 42 has a first horizontal plate portion 43 to which the horizontal stay 42 is attached to the reinforcing girder 3b, and a second horizontal plate portion 44 to which the vertical stay 45 is attached.

[0030] The first horizontal plate portion 43 has multiple through holes 43a formed at intervals in the front-rear direction, through which bolts (not shown) for fastening the first horizontal plate portion 43 to the reinforcing girder 3b are inserted. This allows the mounting position of the first horizontal plate portion 43 to the reinforcing girder 3b to be adjusted in the front-rear direction. Furthermore, since each through hole 43a is an elongated hole formed in the left-right direction in the first horizontal plate portion 43, the mounting position of the first horizontal plate portion 43 to the reinforcing girder 3b can also be adjusted in the left-right direction.

[0031] The second horizontal plate portion 44 has multiple through holes 44a formed at intervals in the front-rear direction, through which bolts (not shown) for fastening the vertical stays 45 to the second horizontal plate portion 44 are inserted. This allows the mounting position of the vertical stays 45 to the second horizontal plate portion 44 to be adjusted in the front-rear direction. Furthermore, since each through hole 44a is an elongated hole formed in the second horizontal plate portion 44 in the vertical direction, the mounting position of the vertical stays 45 to the second horizontal plate portion 44 can also be adjusted in the vertical direction.

[0032] The vertical stay 45 is made of an L-shaped angle material that extends in the vertical direction. The vertical stay 45 is positioned to the left (outward in the vehicle width direction) of the left lower arm 23. The vertical stay 45 has a first vertical plate portion 46 to which the vertical stay 45 is attached to the second horizontal plate portion 44, and a second vertical plate portion 47 to which the first detection unit 41 is attached.

[0033] The first vertical plate portion 46 has multiple through holes 46a formed at intervals in the vertical direction, through which bolts (not shown) that fasten the first vertical plate portion 46 to the second horizontal plate portion 44 are inserted. Each through hole 46a is an elongated hole formed in the first vertical plate portion 46 in the vertical direction. This allows the mounting position of the first vertical plate portion 46 relative to the second horizontal plate portion 44 to be adjusted in the vertical direction. The first detection unit 41 is fixed to the lower part of the second vertical plate portion 47.

[0034] As described above, the first detection unit 41 is attached to the reinforcing beam 3b of the cargo box 3 via a horizontal stay 42 that is attached to the reinforcing beam 3b so as to be adjustable in the front-rear direction, and a vertical stay 45 that is attached to the horizontal stay 42 so as to be adjustable in the front-rear direction and the up-down direction, respectively. Therefore, the mounting position of the first detection unit 41 on the reinforcing beam 3b can be adjusted in the front-rear direction and the up-down direction by the horizontal stay 42 and the vertical stay 45.

[0035] The first detection unit 41 consists of, for example, a proximity sensor. The detection surface 41a of the first detection unit 41 is positioned so that the left lower arm 23 approaches it when the loading platform 11 is raised to the raised position T1. In this embodiment, the first detection unit 41 detects that the loading platform 11 is at the raised position T1 when the left lower arm 23 approaches the detection surface 41a when the loading platform 11 is raised to the raised position T1. The detection signal from the first detection unit 41 is output to the control unit 52, which will be described later.

[0036] [Second detection unit] Figure 5 is an enlarged side view showing the area near the base 11b of the loading platform 11. In Figures 1 and 5, the loading platform lifting device 10 further includes a second detection unit 48 that detects when the loading platform 11 is in a collapsed position T4. The second detection unit 48 consists of, for example, a proximity sensor and is attached to the base 11b of the loading platform 11.

[0037] The detection surface 48a of the second detection unit 48 is positioned to be close to the connecting link 24 when the loading platform 11 is tilted and rotated to the tilted position T4. As a result, the second detection unit 48 in this embodiment detects that the tilted position of the loading platform 11 is the tilted position T4 when the detection surface 48a is close to the connecting link 24. The detection signal from the second detection unit 48 is output to the control unit 52, which will be described later.

[0038] [Newspaper Department] Figure 6 is a perspective view looking from inside the cargo box 3 towards the rear when the loading platform 11 is in the raised position T1. In Figure 6, the loading platform lifting device 10 further includes a notification unit 51 that notifies the worker that the loading platform 11 is in the raised position T1 and in the lowered position T4. The notification unit 51 is, for example, a lamp such as an LED light. In this embodiment, the notification unit 51 is installed inside the cargo box 3 so as not to be mistaken for a light device such as a brake lamp (not shown) installed on the outside of the cargo box 3 at the rear of the cargo vehicle 1. Specifically, the notification unit 51 in this embodiment is attached to a support column 3d located at the rear end of the left side wall 3c of the cargo box 3.

[0039] Furthermore, the notification unit 51 is mounted on the front surface 3e of the support column 3d, near the installation position of the in-cabin remote control 18, which is at eye level, so that it can be easily seen by workers working inside the cargo box 3. The in-cabin remote control 18 is a wired remote controller provided on the cargo receiving platform lifting device 10 for workers to operate the raising and lowering and tilting of the receiving platform 11 inside the cargo box 3. The illumination and extinguishing of the notification unit 51 are controlled by the control unit 52, which will be described later.

[0040] [Control Unit] Figure 7 is a block diagram showing the control configuration of the loading platform lifting device 10. In Figure 7, the loading platform lifting device 10 further includes a control unit 52 that controls the notification unit 51. The control unit 52 is located in the power unit (not shown) of the loading platform lifting device 10. The control unit 52 is configured with a computer having a CPU or the like. Each function of the control unit 52 is performed by the CPU executing a control program stored in the computer's storage device.

[0041] The control unit 52 is connected to the first detection unit 41, the second detection unit 48, and the notification unit 51 via signal lines (not shown). The detection signals from the first detection unit 41 and the second detection unit 48 are input to the control unit 52. The control unit 52 controls the lighting and extinguishing of the notification unit 51 based on these detection signals.

[0042] Specifically, the control unit 52 lights up the notification unit 51 (causes the notification unit 51 to notify) while both the detection signal from the first detection unit 41 and the detection signal from the second detection unit 48 are being input. If, from this state, either the detection signal from the first detection unit 41 or the detection signal from the second detection unit 48 is no longer input to the control unit 52, the control unit 52 turns off the notification unit 51 (stops the notification unit 51 from notifying).

[0043] Figure 8 is a flowchart showing an example of control of the notification unit 51 performed by the control unit 52. The following describes an example of control performed by the control unit 52 from a state where the notification unit 51 is off, with reference to Figure 8. First, the control unit 52 determines whether or not a detection signal has been input to the first detection unit 41 (step ST1). If no detection signal has been input to the first detection unit 41 (if "No" is found in step ST1), the control unit 52 returns to step ST1 and, after a predetermined time has elapsed, performs the determination in step ST1 again.

[0044] On the other hand, if a detection signal is input from the first detection unit 41 (if "Yes" is answered in step ST1), the control unit 52 then determines whether or not a detection signal from the second detection unit 48 has been input (step ST2). Note that the determination in step ST2 may be performed before the determination in step ST1.

[0045] If no detection signal is input from the second detection unit 48 (if "No" is the result in step ST2), the control unit 52 returns to step ST1 and, after a predetermined time has elapsed, performs the determination in step ST1 again. On the other hand, if a detection signal is input from the second detection unit 48 (if "Yes" is the result in step ST2), the control unit 52 lights up the notification unit 51 (step ST3).

[0046] Next, the control unit 52 determines whether or not the detection signal from the first detection unit 41 has been stopped (step ST4). If the detection signal from the first detection unit 41 has been stopped (if the answer is "Yes" in step ST4), the control unit 52 turns off the notification unit 51 (step ST5) and returns to step ST1.

[0047] On the other hand, if the detection signal from the first detection unit 41 is still being input (if the result is "No" in step ST4), the control unit 52 then determines whether or not the detection signal from the second detection unit 48 has been stopped being input (step ST6). Note that the determination in step ST6 may be made before the determination in step ST4. If the detection signal from the first detection unit 41 has been stopped being input (if the result is "Yes" in step ST6), the control unit 52 turns off the notification unit 51 (step ST5) and returns to step ST1.

[0048] On the other hand, if the detection signal from the second detection unit 48 is still being input (i.e., "No" in step ST6), the control unit 52 returns to step ST4 and, after a predetermined time has elapsed, performs the determination in step ST4 again.

[0049] Through the above control, the notification unit 51 remains lit (notifies) as long as both detection signals from the first detection unit 41 and the second detection unit 48 are input to the control unit 52, that is, as long as the loading platform 11 is in the raised position T1 and the lowered position T4. From this state, if either the detection signal from the first detection unit 41 or the second detection unit 48 is no longer input to the control unit 52, the notification unit 51 turns off (stops notifying). For example, if the loading platform 11, which is in the raised position T1, is lowered or rotated to an upright position, the notification unit 51 turns off. Also, if the mounting surface 11a of the loading platform 11, which is in the raised position T1, is tilted downwards to bridge the loading platform 11 to the platform (see Figure 10 of Japanese Patent Application Publication No. 2003-165378), the notification unit 51 turns off.

[0050] [Effects of this embodiment] According to the loading platform lifting device 10 of this embodiment, while the first detection unit 41 detects that the loading platform 11 is at a raised position T1 at the same height as the floor surface 3a of the loading box 3, the control unit 52 lights up the notification unit 51. This allows the worker to move the cargo between the floor surface 3a of the loading box 3 and the mounting surface 11a of the loading platform 11 when the notification unit 51 is notifying, that is, when the loading platform 11 is at the same height as the floor surface 3a of the loading box 3. As a result, it is possible to suppress the movement of cargo when the loading platform 11 is at a lower position than the floor surface 3a of the loading box 3, thereby suppressing a decrease in the work efficiency of the movement work. In particular, the loading platform lifting device 10 of this embodiment is more effective when moving a cart used to transport cargo between the floor surface 3a and the mounting surface 11a.

[0051] Furthermore, the control unit 52 illuminates the notification unit 51 when the loading platform 11 is in the raised position T1 and in the reclined position T4. Therefore, if the loading platform 11 is in the raised position T1 but in the upright position T5, the notification unit 51 will not illuminate. This reduces power consumption when the loading platform 11 is in the upright position T5 and the cargo truck 1 is driven.

[0052] Furthermore, since the notification unit 51 is located inside the cargo box 3, workers can easily ascertain that the loading platform 11 is in the raised position T1, even while working inside the cargo box 3. In addition, it is possible to prevent the notification unit 51 from being mistaken for a light such as a brake light located at the rear of the cargo truck 1.

[0053] Furthermore, the mounting position of the first detection unit 41 on the reinforcing beam 3b can be adjusted in the front-rear and up-down directions by the horizontal stays 42 and vertical stays 45, so that the first detection unit 41 can reliably detect that the load receiving platform 11 is in the raised position T1.

[0054] [others] The loading platform lifting device 10 in the above embodiment is of the upright retractable type, but other types of loading platform lifting devices such as the underfloor retractable type or the vertical lifting type may also be used.

[0055] In the above embodiment, the first detection unit 41 detects the left lower arm 23, but is not limited to this. For example, the first detection unit 41 may detect the right lower arm 23, either the left or right upper arm 22, either the left or right connecting link 24, or the loading platform 11 in the raised position T1. The first detection unit 41 may also be provided on the lifting mechanism 12. In that case, the first detection unit 41 should detect the vehicle body 2, the support part 14, or the bracket 17 when the loading platform 11 is in the raised position T1. The first detection unit 41 may also be provided on the loading platform 11. In that case, the first detection unit 41 should detect the loading box 3 or the lifting mechanism 12 when the loading platform 11 is in the raised position T1. Furthermore, the first detection unit 41 is not limited to a proximity sensor, but may be, for example, a limit switch. The mounting structure of the first detection unit 41 is not limited to the horizontal stay 42 and the vertical stay 45, but may be other mounting structures.

[0056] In the above embodiment, the second detection unit 48 is provided on the loading platform 11 and detects the connecting link 24, but it may also be provided on the connecting link 24 and detect the loading platform 11. Furthermore, the second detection unit 48 is not limited to a proximity sensor, but may be, for example, a limit switch or an angle sensor that detects the elevation angle of the loading platform 11.

[0057] In the above embodiment, the control unit 52 is dedicated to controlling the notification unit 51, but it may also be used to control the drive of the loading platform lifting device 10. In addition, in the above embodiment, the control unit 52 makes the notification unit 51 make a notification when both detection signals from the first detection unit 41 and the second detection unit 48 are input, but the notification unit 51 may also make a notification when only the detection signal from the first detection unit 41 is input.

[0058] The mounting position of the notification unit 51 is not limited to this embodiment. For example, the notification unit 51 may be installed on the right side of the cargo box 3, on the floor 3a, or on the ceiling, or on the loading platform 11. In the latter case, it is preferable to illuminate the notification unit 51 towards the inside of the cargo box 3 when the loading platform 11 is in the raised position T1, so that it can be easily seen by workers working inside the cargo box 3.

[0059] The notification unit 51 currently indicates that the loading platform 11 is in the raised position T1 by the difference between being lit and being off. However, it may also indicate that the loading platform 11 is in the raised position T1 by the difference between being lit and flashing, or by changing the color of the light. For example, if the color of the light is changed, the notification unit 51 may light up red if the loading platform 11 is not in the raised position T1, and light up blue when the loading platform 11 is in the raised position T1. In addition to lamps, the notification unit 51 may also notify by displaying text on an LCD screen, or by providing audio notification via an alarm buzzer or speaker.

[0060] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not in the sense described above, and is intended to include all modifications in the sense and scope equivalent to the claims. [Explanation of Symbols]

[0061] 2 car bodies 3 packing boxes 3a Floor surface 10 Loading platform lifting device 11 Loading platform 12 Lifting mechanism 13 Luffing mechanism 41 First detection unit 48 Second detection unit 51 Hochi Department 52 Control Unit T1 Ascent Position T2 lowering position T4 Lodging position T5 standing posture

Claims

1. A loading platform having a loading surface on which cargo is placed in order to load and unload cargo from a cargo box mounted on the vehicle body, A lifting mechanism that raises and lowers the loading platform between a raised position at the same height as the floor of the loading box and a lowered position where it touches the ground, while the mounting surface maintains a horizontal position. A first detection unit that detects that the lifting position of the loading platform is the raised position, A second detection unit detects that the mounting surface is in a horizontal position, A notification unit that informs the worker that the loading platform is in the raised position, A loading platform lifting device comprising: a control unit that causes the notification unit to provide notification while both the detection signal from the first detection unit and the detection signal from the second detection unit are input, and stops the notification unit from providing notification when either the detection signal from the first detection unit or the detection signal from the second detection unit is no longer input.

2. The load-receiving platform is further provided with a luffing mechanism that causes the load-receiving platform to luff and rotate between an upright position and a reclined position when the load-receiving platform is in the raised position. The loading platform lifting device according to claim 1, wherein the second detection unit detects that the loading platform is in the tilted position and the aforementioned surface is in a horizontal position.

3. The lifting mechanism comprises an upper arm and a lower arm positioned below the upper arm. The loading platform lifting device according to claim 1 or claim 2, wherein the first detection unit detects the upper arm or the lower arm when the loading platform is raised to the raised position.

4. The notification unit is provided inside the cargo box, as described in any one of claims 1 to 3.

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