Loading platform lifting device

Abstract

The objective is to provide a loading platform lifting device in which, when the lifting mechanism is in the retracted position while positioned on the loading platform, at least the lower part of the lifting mechanism is located inside the loading platform. [Solution] The present invention provides a loading platform lifting device that can be placed on the loading platform of a vehicle, comprising a loading platform on which a load can be placed and a vertically extending lifting support column, a lifting section for raising and lowering the loading platform along the lifting support column, and a reciprocating section that, when positioned on the loading platform, allows the lifting section to move back and forth between a retracted position on the loading platform and an extended position outside the edge of the loading platform in a plan view, wherein the lower end of the lifting section when it is in the retracted position is located above the loading platform and inside the edge of the loading platform in a plan view.

Description

Technical Field

[0004]

[0001] The present invention relates to a load receiving platform lifting device disposed on a loading platform of a vehicle or the like.

Background Art

[0002] Conventionally, a load receiving platform lifting device that raises and lowers a load placed on a load receiving platform for loading and unloading operations of a load onto a loading platform of a vehicle or the like has been known (see Patent Document 1).

[0003] Specifically, as shown in FIG. 17, in a cargo truck C where a load receiving platform lifting device 500 is disposed, a second floor 503 is disposed on a U-shaped guide rail 502 disposed along the side edge of a loading platform floor 501, and a guide member 504 is slidably disposed in the guide rail 502 so as to be movable along the guide rail 502.

[0004] At both ends of the guide member 504, a pair of supports 510 project from an opening of the guide rail 502, and a lifting part 520 is attached to the tip of each support 510.

[0005] The lifting part 520 is a device that moves the load receiving platform 521 up and down from the ground to the loading platform height, and the support 510 is composed of a fixed bracket 511, a first link 512, and a second link 513.

[0006] Specifically, a base end portion of the fixed bracket 511 is fixed to the guide member 504, and a tip end portion of the fixed bracket 511 projects from the guide member 504. The first link 512 and the second link 513 form a parallel link, and the base end portions are pivotally supported 512a, 513a at the tip end portion of the fixed bracket 511, and the tip end portions are pivotally supported 512b, 513b on an outer cylinder 522 of the lifting part 520, respectively. By the pivotal supports 512a, 513a, the first link 512 and the second link 513 swing up and down, so that the lifting part 520 swings between a retracted position P51 where the first link 512 and the second link 513 are in a standing state and an advanced position P52 where they are in a horizontal state.

[0007] Specifically, when the first link 512 and the second link 513 are in an upright position, the lifting unit 520 moves to the inward retracted position P51 while maintaining a vertical position, along with the swinging of the first link 512 and the second link 513. Conversely, when the first link 512 and the second link 513 are in a horizontal position, the lifting unit 520 moves to the outward extended position P52 while maintaining a vertical position, along with the swinging of the first link 512 and the second link 513. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 4185291 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, with the above-described loading platform lifting device 500, even at the retracted position P51, the lifting section 520 is located outside the loading platforms 501 and 502, and the vehicle width and length at the loading platforms 501 and 502 are increased by the amount of the lifting section 520. In addition, if the lifting section 520 is located outside the loading platforms 501 and 502 at the height of the loading platforms 501 and 502, it becomes difficult to install tailgates around the location of the loading platform lifting device 500 on the loading platforms 501 and 502.

[0010] Therefore, the object of the present invention is to provide a loading platform lifting device in which, when the lifting unit is in the retracted position while positioned on the loading platform, at least the lower part is located inside the loading platform. [Means for solving the problem]

[0011] The load receiving platform lifting device of the present invention is A loading platform lifting device that can be installed on the loading platform of a vehicle, It has a loading platform on which cargo can be placed and a vertically extending lifting support column, and a lifting section that raises and lowers the loading platform along the lifting support column, The lifting mechanism, when positioned on the aforementioned loading platform, is provided with a retractable mechanism that allows it to move back and forth between a retracted position on the loading platform and an extended position outside the edge of the loading platform in a plan view, When the lifting mechanism is in the retracted position, its lower end is located above the cargo bed and, in a plan view, inside the edge of the cargo bed.

[0012] With this configuration, when the retractable section is positioned on the loading platform, the lifting section is retracted by the retractable section (i.e., the loading platform lifting device is in a stored position), so that at least the lower part of the loading platform lifting device (lifting section) is located inside the edge of the loading platform in a plan view.

[0013] In the aforementioned loading platform lifting device, The aforementioned reciprocating section includes a cylinder that extends and retracts in accordance with the reciprocating movement of the lifting section. The cylinder may be retracted when the lifting mechanism is in the extended position.

[0014] By configuring the cylinder to retract when the lifting section is in the extended position (i.e., the rod is retracted into the cylinder tube), buckling of the cylinder is prevented when the lifting section is in the extended position and loading or unloading cargo onto the platform.

[0015] Furthermore, in the aforementioned loading platform lifting device, The aforementioned lifting mechanism is When in the aforementioned extended position, a cross member is located between the loading platform and the loading platform in a plan view, and its upper end extends along the edge of the loading platform with a gap between it and the loading platform, The cross member is attached to the cross member so as to be rotatable about an axis extending in the same direction as the upper end of the cross member, The connecting member rotates with the movement of the lifting section, so that when the lifting section is in the extended position, it is in a first position where it is stretched from the upper end of the cross member to the loading platform, while when the lifting section is in the retracted position, it may be in a second position along the lifting support column.

[0016] According to such a configuration, since the transfer member is bridged from the upper end of the cross member to the loading platform when the lifting part is in the extended position, when moving a load between the load receiving platform and the loading platform, it is possible to prevent the load from getting stuck between the cross member and the loading platform. Moreover, when the lifting part is in the retracted position, the transfer member is in a posture along the lifting column and does not interfere.

[0017] Also, in the load receiving platform lifting device, The lifting part may have a step arranged on the lifting column so that the posture can be changed between a storage posture along the lifting column and a protruding posture protruding from the lifting column.

[0018] According to such a configuration, by putting the step in the protruding posture and using it as a foothold, it becomes easier for an operator or the like to get on and off the loading platform. Moreover, when the step is not used, it is put in the storage posture so as not to interfere.

Effect of the Invention

[0019] As described above, according to the present invention, it is possible to provide a load receiving platform lifting device in which at least the lower part is located inside the loading platform when the lifting part is in the retracted position while being arranged on the loading platform.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a perspective view of the rear part of a cargo vehicle on which the load receiving platform lifting device of the present embodiment is installed, and is a perspective view of a state where the lifting unit is in the extended position and the load receiving platform is in the raised position. [Figure 2] FIG. 2 is a perspective view of the rear part of the cargo vehicle, and is a perspective view of a state where the lifting unit is in the extended position and the load receiving platform is in the lowered position. [Figure 3] FIG. 3 is a side view showing the movement of the load receiving platform when the lifting unit is in the extended position. [Figure 4] FIG. 4 is a side view of the load receiving platform lifting device when the lifting unit is in the retracted position. [Figure 5]Figure 5 is a view of the loading platform lifting device from the rear of the vehicle when the lifting unit is in the retracted position. [Figure 6] Figure 6 is an enlarged perspective view illustrating the steps located at the lower end of the lifting column. [Figure 7] Figure 7 is an enlarged perspective view illustrating the configuration of the retractable unit, and is an enlarged perspective view of the lifting unit in its retracted position. [Figure 8] Figure 8 is an enlarged perspective view illustrating the configuration of the retractable unit, and is an enlarged perspective view of the lifting unit in its extended position. [Figure 9] Figure 9 is a view of the lifting support column and its surroundings from the rear of the vehicle when the lifting unit is in the retracted position. [Figure 10] Figure 10 is a cross-sectional view at position XX in Figure 5, showing the lifting unit in its retracted position. [Figure 11] Figure 11 is a cross-sectional view at position XX in Figure 5, showing the lift arm and compression arm constituting the link mechanism in an upward-slanting orientation. [Figure 12] Figure 12 is a cross-sectional view at position XX in Figure 5, showing the lift arm and compression arm constituting the link mechanism in a horizontal position. [Figure 13] Figure 13 is a cross-sectional view at position XX in Figure 5, showing the lift arm and compression arm constituting the link mechanism in a downward-slanting orientation. [Figure 14] Figure 14 is a cross-sectional view at position XX in Figure 5, showing the lifting unit in its extended position. [Figure 15] Figure 15 is a side view of the loading platform lifting device when the loading platform is in the raised position. [Figure 16] Figure 16 is a side view of the loading platform lifting device when the loading platform is positioned at an intermediate position between the raised and lowered positions. [Figure 17] Figure 17 is a diagram illustrating the configuration of a conventional loading platform lifting device. [Modes for carrying out the invention]

[0021] The following describes one embodiment of the present invention with reference to Figures 1 to 16.

[0022] As shown in Figures 1 to 5, the loading platform lifting device 1 according to this embodiment is positioned (installed) on the loading platform 101 of a cargo vehicle (vehicle) 100, and raises or lowers the cargo placed on the loading platform 24 when loading or unloading cargo onto the loading platform 101. This cargo vehicle 100 comprises a loading platform 101, a pair of side walls 102 positioned at both ends of the loading platform 101 in the vehicle width direction, and a tailgate 103 positioned at the rear end of the loading platform 101. In the example shown in Figure 1, the loading platform lifting device 1 is positioned at the rear end of the loading platform 101, offset to one side in the vehicle width direction. That is, the dimensions of the loading platform lifting device 1 in the vehicle width direction are smaller than the dimensions of the loading platform 101 in the vehicle width direction. The loading platform lifting device 1 may also be positioned at the side end (end in the vehicle width direction) of the loading platform 101. Furthermore, in the following explanation, the direction corresponding to the front and rear of the cargo vehicle 100 is referred to as the longitudinal direction, the direction corresponding to the width of the cargo vehicle 100 is referred to as the left-right direction, and the direction perpendicular to both the longitudinal direction and the left-right direction is referred to as the vertical direction.

[0023] The loading platform lifting device 1 includes a loading platform 24 on which loads can be placed and a vertically extending lifting support column 20, and comprises a lifting unit (lifting section) 2 that raises and lowers the loading platform 24 along the lifting support column 20, and a reciprocating unit (reciprocating section) 3 that, when positioned on the loading platform 101, can move the lifting unit 2 between a retracted position P1 (position shown in Figure 4) and an extended position P2 (position shown in Figure 1). The loading platform lifting device 1 also includes an operation panel 5 for operating the lifting unit 2 and the reciprocating unit 3 (see Figure 3).

[0024] The lifting unit 2 includes a pair of lifting support columns 20, a pair of sliders 23, a loading platform 24, a cross member 25, and a lifting mechanism 26 (see Figure 5). The lifting unit 2 in this embodiment also includes a transfer plate (transfer member) 27 and a step 28 (see Figure 6).

[0025] The pair of lifting columns 20 each extend vertically and are spaced apart horizontally so as to be parallel to each other (see Figure 5). Each lifting column 20 has a cylindrical outer column 21 that extends vertically and an inner column 22 that extends vertically and is movable up and down relative to the outer column 21. The lower end 22k of the inner column 22 can be grounded when lowered.

[0026] The outer column 21 is a hollow rectangular tube and has vertically extending slits 21a on its rear wall (see Figure 2).

[0027] The inner column 22 is positioned within the outer column 21 so as to be able to move up and down relative to the outer column 21. Each inner column 22 is a hollow rectangular tube extending in the vertical direction and has a vertically extending slit 22a in its rear wall (see Figure 2).

[0028] Each pair of sliders 23 has a slider body positioned within the inner column 22, and a slider rear portion 232 that protrudes outward (rearward) from the slider body through the slits 22a and 21a of the inner column 22 and outer column 21, respectively. Each pair of sliders 23 also has a bracket 233 that protrudes rearward from the slider rear portion 232 (the lower end of the slider rear portion 232 in this embodiment).

[0029] The slider body has rollers that roll against the inner surface of the inner column 22, and the rolling of these rollers allows it to move smoothly up and down inside the inner column 22.

[0030] The brackets 233 of each slider 23 rotatably support the loading platform 24.

[0031] The loading platform 24 has a main plate 241 and a sub-plate 242. In this loading platform 24, the main plate 241 has a pin 241a extending in the left-right direction at its base end (the end on the lifting support column 20 side), and the pin 241a is supported by a bracket 233. As a result, the main plate 241 is rotatable around the pin 241a as the center of rotation (see arrow α1 in Figure 4). The sub-plate 242 is connected at its base end to the tip of the main plate 241 via a hinge 243, and is rotatable relative to the main plate 241 (see arrow α2 in Figures 15 and 16).

[0032] As described above, the loading platform 24, which is composed of the main plate 241 and the subplate 242, is rotatable between a deployed position where it is horizontally unfolded relative to each outer column 21 (the position shown by the dashed line in Figure 3) and an upright storage position where it is erected along the rear wall of each outer column 21 (the position shown by the double dashed line in Figure 3).

[0033] When the loading platform 24 is in its deployed position, the main plate 241 and the sub-plate 242 extend horizontally toward the rear of each outer column 21, and the surfaces (top surfaces) of the main plate 241 and the sub-plate 242 constitute the loading surface 24a on which the load is placed. This loading surface 24a is a flat surface such that, when the loading platform 24 is in its deployed position, it does not cause snagging when, for example, a drum is rolled (i.e., it does not hinder the movement of the load).

[0034] On the other hand, when the loading platform 24 is in the upright storage position, the main plate 241 rotates to stand upright along the rear wall of each outer column 21, and the sub-plate 242 rotates to the surface (upper surface) of the upright main plate 241 to lie along that surface (i.e., the loading platform 24 is folded). As a result, the loading platform 24 becomes compact in the vertical direction when in the upright storage position. In this upright storage position, the sub-plate 242 is located between the pair of outer columns 21.

[0035] The cross member 25 is positioned between a pair of outer columns 21 and connects them. In this embodiment, the cross member 25 connects approximately the entire lower half of both outer columns 21. This cross member 25 is formed in the shape of a hollow rectangular box, and the internal space of the cross member 25 is in communication with the internal space of each outer column 21.

[0036] The upper surface 25a of the cross member 25 is at the same or approximately the same height as the floor surface (upper surface) 101a of the cargo bed 101 when the lifting unit 2 is in the extended position P2 (see Figures 1 and 2). That is, the upper end of the cross member 25 extends along the edge (rear edge) of the cargo bed 101 at the same or approximately the same height as the cargo bed 101 (floor surface 101a) when the lifting unit 2 is in the extended position P2. In this embodiment, the upper surface 25a of the cross member 25 is slightly higher than the floor surface 101a of the cargo bed 101 when the lifting unit 2 is in the extended position P2 (see Figure 14). In this embodiment, the edge of the cargo bed 101 refers to the position of the innermost surface of the closed side wall 102 (the edge at that position) and the position of the innermost surface of the closed tailgate 103 (the edge at that position) in a plan view. Furthermore, in the case where the cargo bed 101 does not have side walls 102 or tailgate doors 103, the edge of the cargo bed 101 is the outermost part of the cargo bed (including the floorboard and frame, but excluding the side walls 102, tailgate doors 103, hinges of the side walls 102, and hinges of the tailgate doors 103) 101 in a plan view (the rearmost part in the case of the rear edge, and the rightmost or leftmost part in the case of the side edge).

[0037] The lifting mechanism 26 raises and lowers the unfolded loading platform 24 relative to the pair of outer columns 21 between the position of the floor surface (upper surface) 101a of the loading platform 101 (upper position P11) and the ground (lower position P12) in the vertical direction (see Figure 3).

[0038] Specifically, the lifting mechanism 26 consists of a hydraulic cylinder 261, a fixed sheave 262, a movable sheave 263, and wires, etc., arranged within the cross member 25 (see Figure 5).

[0039] In this lifting mechanism 26, when the hydraulic cylinder 261 extends, the slider 23 and the inner column 22 rise via wires wrapped around the fixed sheave 262 and the movable sheave 263. Specifically, the slider 23 rises relative to the inner column 22, and then the inner column 22 rises relative to the outer column 21 together with the slider 23. As a result, the loading platform 24 rises to the raised position P11. When the loading platform 24 rises to the raised position P11, the loading surface 24a of the loading platform 24 is at the same or approximately the same height as the upper surface 25a of the cross member 25 (i.e., the floor surface 101a of the loading platform 101) (see Figure 1).

[0040] Meanwhile, in the lifting mechanism 26, when the hydraulic cylinder 261 retracts, the slider 23 and inner column 22 descend via wires wrapped around the fixed sheave 262 and the movable sheave 263. Specifically, the inner column 22 descends with the slider 23 relative to the outer column 21, and then the slider 23 descends further relative to the inner column 22. As a result, the loading platform 24 descends to the lowered position P12. When the loading platform 24 descends to the lowered position P12, the loading platform 24 is in contact with the ground (see Figure 3).

[0041] The bridging plate 27 is a plate-shaped member that spans between the lifting unit 2 in the extended position P2 and the loading platform 101, and is attached to the cross member 25 so as to be rotatable around an axis that extends in the same direction as the direction in which the upper end of the cross member 25 extends (in this embodiment, the left-right direction). The bridging plate 27 rotates as the lifting unit 2 moves forward and backward, so that when the lifting unit 2 is in the extended position P2, it is in a first position (shown in Figure 14) where it spans between the cross member 25 and the loading platform 101 in a plan view, while when the lifting unit 2 is in the retracted position P1, it is in a second position (shown in Figure 10) along the outer column 21.

[0042] Specifically, the bridging plate 27 is a rectangular plate-shaped member that is elongated in the left-right direction, and its rear end (the end on the cross member 25 side) is rotatably attached to the front wall of the upper end of the cross member 25 by a hinge 271 (see Figure 14). The front end of the bridging plate 27 (the end on the cargo bed 101 side) is connected to the reciprocating unit 3 (for details, see the base 31 described later: see Figures 1 and 2) by an elastic member (a spring in this embodiment) B.

[0043] In this embodiment, the bridging plate 27 can only be rotated from the second position to a position where its front end is lower than horizontal due to the tensile force of the elastic member B (see Figure 13). However, when the lifting unit 2 moves toward the extended position P2, it is pushed by the loading platform 101 (floor surface 101a) and can be rotated to a nearly horizontal position (first position) (see Figure 14).

[0044] Step 28 is the part where workers or others place their feet when climbing onto the loading platform 101. As shown in Figure 6, Step 28 is positioned on the outer column 21 so as to be able to change its posture between a retracted position along the outer column 21 (indicated by a dashed line in Figure 6) and a protruding position where it protrudes from the outer column 21 (indicated by a solid line in Figure 6). In this embodiment, Step 28 changes its posture by rotation.

[0045] Specifically, step 28 includes a base 281 connected to the outer column 21 and a footrest 282 rotatably connected to the base 281, the footrest 282 having a rectangular annular footrest body 283 and an extension 284 extending from the footrest body 283 to the base 281.

[0046] This footrest portion 282 is positioned on the side wall of the lower part of the outer column 21 and is rotatable between a retracted position along the side wall of the outer column 21 with the footrest portion body 283 positioned above the extension portion 284, and a protruding position in which it extends horizontally (protrudes) from the side wall of the outer column 21.

[0047] As shown in Figures 7 to 9, the retractable unit 3 includes a pair of bases 31, a pair of lift arms 32, a pair of compression arms 33, and a pair of cylinders 34.

[0048] Each of the pair of bases 31 extends vertically and is positioned with a gap between them in the left-right direction (in this embodiment, they are fixed to the floor surface 101a of the cargo bed 101). Each base 31 has an L-shaped base body 311 when viewed from the left-right direction, and a pair of support parts 315 connected to the base body 311 with a gap between them in the left-right direction.

[0049] The base body 311 has a plate-shaped fixing portion 312 that extends along the floor surface 101a of the cargo bed 101 and is fixed to the floor surface 101a, and a plate-shaped upright portion 313 that extends upward from the front end of the fixing portion 312. The fixing portion 312 is a rectangular plate in plan view and is fixed to the cargo bed 101 such that its rear end is located slightly in front of the rear end of the cargo bed 101 (see Figure 4). The upright portion 313 is a plate that extends along a plane direction perpendicular to the front-rear direction.

[0050] The pair of support portions 315 are plate-shaped parts that extend in the vertical and horizontal directions, respectively, with the horizontal dimension of the lower end being greater than the horizontal dimension of the upper end. In the support portion 315 of this embodiment, the front edge 315a extends in the vertical direction, and the rear edge 315b is L-shaped when viewed from the left and right directions.

[0051] Each front end 32a of the pair of lift arms 32 is positioned between a pair of support parts 315 and is attached to the pair of support parts 315 so as to be rotatable around a support shaft 321 that extends in the left-right direction. Each rear end 32b of the pair of lift arms 32 is attached to the outer column 21 so as to be rotatable around a support shaft 322 that extends in the left-right direction.

[0052] Each front end 33a of the pair of compression arms 33 is positioned below the front end 32a of the lift arm 32 between the pair of support parts 315 and is attached to the pair of support parts 315 so as to be rotatable around a pivot shaft 331 that extends in the left-right direction. Each rear end 33b of the pair of compression arms 33 is attached to the outer column 21 so as to be rotatable around a pivot shaft 332 that extends in the left-right direction, at a position below the rear end 32b of the lift arm 32.

[0053] Each compression arm 33 has a cylinder insertion hole 335 through which a cylinder 34 is inserted. The cylinder insertion hole 335 is shaped so that the cylinder 34 does not come into contact with the compression arm 33 when the lifting unit 2 moves forward and backward. In addition, since a power unit 35, which will be described later, is installed in the cylinder 34 of this embodiment, the cylinder insertion hole 335 is shaped so that the power unit 35 also does not come into contact with the compression arm 33 when the lifting unit 2 moves forward and backward.

[0054] The compression arm 33 is positioned below the lift arm 32 and, together with the lift arm 32, base 31, and outer column 21, forms a link mechanism R. Because this link mechanism R is configured at both ends of the lifting unit 2 in the left-right direction, the lifting unit 2 can swing between the retracted position P1 and the extended position P2 while maintaining the posture of the outer column 21.

[0055] According to this link mechanism R, when the lifting unit 2 is in the retracted position P1, the lower ends of the lifting support columns 20 (the lower ends 21k and 22k of the outer column 21 and the inner column 22, respectively) are located between the pair of support parts 315 and above the fixing part 312 when viewed from the front-rear direction (see Figures 7 and 9). Also, when viewed from the left-right direction, the lower ends of the lifting support columns 20 (the lower ends 21k and 22k of the outer column 21 and the inner column 22, respectively) are located on the fixing part 312 (see Figure 4).

[0056] The pair of cylinders 34 extend and retract in accordance with the swinging (movement) of the lifting unit 2. In this embodiment, the cylinders 34 are connected to the base 31 and the lift arm 32, and are extended when the lifting unit 2 is in the retracted position P1 (see Figure 7), and retracted when the lifting unit 2 is in the extended position P2 (see Figure 8).

[0057] Specifically, the cylinder 34 includes a cylinder tube 341 and a rod 342 that moves back and forth relative to the cylinder tube 341. The base 341a of the cylinder tube 341 (the base of the cylinder 34) is positioned below the front end 33a of the compression arm 33 between a pair of support parts 315, and is attached to the pair of support parts 315 so as to be rotatable around a pivot shaft 341b that extends in the left-right direction. The tip 342a of the rod 342 (the tip of the cylinder 34) is attached to the middle part of the lift arm 32 so as to be rotatable around a pivot shaft 342b that extends in the left-right direction.

[0058] In this embodiment, a power unit 35 is installed in the cylinder 34. That is, the reciprocating unit 3 of this embodiment has a pair of power units 35 installed in each cylinder 34. This power unit 35 is the hydraulic source for moving the rod 342 forward and backward relative to the cylinder tube 341, and is mounted behind the cylinder tube 341. By having the power unit 35 in the cylinder 34 in this way, loading and unloading of heavy objects (cargo) can be performed smoothly even on slopes. In the reciprocating unit 3 of this embodiment, each cylinder 34 has its own power unit 35. This allows the lifting unit 2 to be swung by the other cylinder 34 in the event of a failure in one cylinder 34.

[0059] In this cylinder 34, when the rod 342 extends out of the cylinder tube 341 (i.e., the cylinder 34 extends), the link mechanism R swings and the lifting unit 2 moves from the extended position P2 towards the retracted position P1. When the lifting unit 2 has moved to the retracted position P1, the lower end of each lifting support column 20 is located above the floor surface 101a of the loading platform 101 and, in a plan view, inside (forward) of the edge (rear edge) of the loading platform 101.

[0060] Meanwhile, in cylinder 34, when rod 342 retracts into cylinder tube 341 (i.e., cylinder 34 contracts), the link mechanism R swings, causing the lifting unit 2 to move from retracted position P1 to extended position P2. When the lifting unit 2 has moved to the extended position P2, the lower end of each lifting support column 20 is located below the floor surface 101a of the loading platform 101 and, in a plan view, outside (rearward) of the edge (rear end edge) of the loading platform 101.

[0061] The control panel 5 controls the raising and lowering of the load receiving platform 24 of the lifting unit 2, and the swinging motion of the lifting unit 2 between the retracted position P1 and the extended position P2 by the retraction unit 3, when switches and other controls located on the control panel 5 are operated. In this embodiment, the control panel 5 is attached to the support portion 315 of one of the pair of bases 31, and has a retraction switch 51 and a lifting switch 52 (see Figure 5).

[0062] The forward / backward switch 51 operates the extension and retraction of the cylinder 34 of the forward / backward unit 3, thereby moving (swinging) the position of the lifting unit 2 between the retracted position P1 and the extended position P2. The lifting switch 52 operates the extension and retraction of the hydraulic cylinder 261 of the lifting mechanism 26, thereby moving (raising and lowering) the loading platform 24 between the raised position P11 and the lowered position P12. When these switches 51 and 52 are operated, the loading platform lifting device 1 is activated to load and unload cargo onto the loading platform 101. Specifically, it is as follows.

[0063] First, the tailgate 103 is opened. At this time, the lifting unit 2, which is in an upright storage position with the loading platform 24 folded, is in the retracted position P1 (see Figure 10). In this stored state of the loading platform lifting device 1, the lower ends of the lifting support columns 20 (the lower ends 21k and 22k of the outer column 21 and inner column 22, respectively) are higher than the loading platform 101 and are in front of the rear edge of the loading platform 101 (inside the loading platform 101). As a result, the loading platform lifting device 1 does not get in the way when opening and closing the tailgate 103.

[0064] Next, when the forward / backward switch 51 is operated, each cylinder 34 of the forward / backward unit 3 retracts from the extended state. The forward / backward switch 51 in this embodiment is a lever switch, and as long as the lever is held down, the forward / backward unit 3 continues to operate (i.e., the lifting unit 2 moves forward and backward only while the lever is down). This switch operation causes each arm (lift arm 32, compression arm 33) constituting the link mechanism R to rotate around the pivot shafts 321 and 331, thereby causing the lifting unit 2 to swing (move) from the retracted position P1 to the extended position P2. During this oscillation, the lower ends of the lifting support columns 20 (the lower ends 21k and 22k of the outer column 21 and the inner column 22, respectively) pass through a position with a small gap between them and the rear end of the cargo vehicle 100 (the rear end of the cargo bed 101, the tailgate 103, the hinges of the tailgate 103, etc.) (for example, a position with a minimum gap that prevents contact even if looseness occurs due to manufacturing errors or use over time) (see Figures 10 and 11).

[0065] At this time, the bridge plate 27 is pulled by the spring B from the second position, causing it to rotate around the hinge 271 as the lifting unit 2 moves (see Figures 10 to 13).

[0066] As the forward / backward switch 51 (lever) remains in the down position, each arm 32, 33 constituting the link mechanism R continues to rotate. When each arm 32, 33 constituting the link mechanism R is in a horizontal position, the lower end of the lifting unit 2 (the lower end of the lifting support column 20) is located below the floor surface 101a of the cargo bed 101 (see Figure 12). At this time, a gap is formed between the lifting support column 20 and the rear end of the cargo vehicle 100 in the front-rear direction. Note that the horizontal position of the lift arm 32 is the state in which the line connecting the centers of the support shafts 321 and 322 is horizontal, and the horizontal position of the compression arm 33 is the state in which the line connecting the centers of the support shafts 331 and 332 is horizontal.

[0067] Next, after the arms 32 and 33 constituting the link mechanism R are in a horizontal position, as they continue to rotate, the lifting unit 2 (lifting support column 20) descends and approaches the rear end of the freight vehicle 100 (see Figures 12 and 13. In this embodiment, the lifting unit 2 (lifting support column 20) descends and approaches the tailgate 103), reaching the extended position P2 (see Figure 14).

[0068] When the lifting unit 2 is in the extended position P2, the reinforcing member 251 extending in the left-right direction on the front side (vehicle front side) of the cross member 25 is slightly separated from the tailgate 103 in the front-rear direction. This reinforcing member 251 extends from one outer column 21 to the other outer column 21.

[0069] When the lifting unit 2 reaches the extended position P2, the forward / backward switch 51 (lever) is returned to the neutral position, and the movement of the lifting unit 2 to the extended position by the forward / backward unit 3 is completed.

[0070] When the lifting unit 2 reaches the extended position P2, the loading platform 24, which is in the upright and retracted position, is unfolded by an operator or other person and assumes the unfolded position (see Figure 15).

[0071] In this state, the lifting mechanism 26 of the lifting unit 2 is driven when the lifting switch 52 is operated. The lifting switch 52 in this embodiment is a lever switch, and the lifting unit 2 continues to operate as long as the lever is kept in the downed position (i.e., the loading platform 24 moves up and down only while the lever is down). This switch operation drives the hydraulic cylinder 261 of the lifting mechanism 26, causing the loading platform 24 to move down or up between the raised position P11 and the lowered position P12 (see Figure 16, etc.). This allows the load placed on the loading platform 24 to be raised or lowered and loaded onto the loading platform 101.

[0072] On the other hand, when the loading platform lifting device 1 is returned to its retracted state, the loading platform 24 is moved to the raised position P11 by operating the lifting switch 52 (see Figure 15), and the loading platform 24 is folded up to the upright storage position by an operator or the like (see Figure 14). Subsequently, the forward / backward switch 51 is operated, causing the link mechanism R to swing, and the lifting unit 2 moves from the extended position P2 to the retracted position P1 (see Figures 14 to 10). As a result, the loading platform lifting device 1 is returned to its retracted state, and the lower ends of the lifting support columns 20 (the lower ends 21k and 22k of the outer column 21 and inner column 22, respectively) are positioned higher than the loading platform 101 and in front of the rear edge of the loading platform 101 (inside the loading platform 101).

[0073] In this way, when the loading platform lifting device 1 is retracted, the side door 103 can be closed, and the freight vehicle 100 can travel.

[0074] The above-described loading platform lifting device 1 is a loading platform lifting device 1 that can be positioned on the loading platform 101 of a cargo vehicle (vehicle) 100, and comprises a loading platform 24 on which cargo can be placed and a lifting support column 20 extending in the vertical direction, and a lifting unit (lifting section) 2 that raises and lowers the loading platform 24 along the lifting support column 20, and a reciprocating unit (reciprocating section) 3 that, when positioned on the loading platform 101, can move the lifting unit 2 back and forth between a retracted position P1 on the loading platform 101 and an extended position P2 that is outside the edge of the loading platform 101 in a plan view. When the lifting unit 2 is in the retracted position P1, the lower end of the lifting unit 2 is located above the loading platform 101 and in front of (inside) the rear edge (edge) of the loading platform 101 in a plan view.

[0075] With this configuration, when the retraction unit 3 is positioned on the cargo bed 101, the lifting unit 2 is retracted to position P1 by the retraction unit 3 (i.e., the cargo bed lifting device 1 is in its stored state), so that at least the lower part of the cargo bed lifting device 1 (lifting unit 2) is located inside the cargo bed 101 in a plan view (more specifically, inside the edge of the cargo bed 101). As a result, when the cargo bed lifting device 1 is in its stored state (i.e., when the lifting unit 2 is in position P1), the tailgate 103 on the cargo bed 101 of the freight vehicle 100 can be closed (see the state shown by the dashed line of reference numeral 103 in Figure 4).

[0076] Furthermore, in the loading platform lifting device 1 of this embodiment, the reciprocating unit (reciprocating section) 3 is equipped with a cylinder 34 that expands and contracts in accordance with the reciprocating movement of the lifting unit (lifting section), and when the lifting unit 2 is in the extended position P2, the cylinder 34 is contracted. By configuring the cylinder 34 to contract when the lifting unit 2 is in the extended position P2 (i.e., the rod 342 is retracted into the cylinder tube 341), buckling of the cylinder 34 (more specifically, buckling of the rod 342) is prevented when the lifting unit 2 is in the extended position P2 and loading and unloading cargo onto the loading platform 101 is being performed.

[0077] Furthermore, in the loading platform lifting device 1 of this embodiment, the lifting unit (lifting section) 2 has a cross member 25 that, when in the extended position P2, is located between the loading platform 101 and the loading platform 24 in a plan view, with its upper end spaced apart from the loading platform 101 and extending along the edge of the loading platform 101, and a bridging plate (bridging member) 27 that is attached to the cross member 25 so as to be rotatable around an axis extending in the same direction as the upper end of the cross member 25 extends. The bridging plate 27 rotates as the lifting unit 2 moves forward and backward, so that when the lifting unit 2 is in the extended position P2, it is in a first position where it is stretched from the upper end of the cross member 25 to the loading platform 101, while when the lifting unit 2 is in the retracted position P1, it is in a second position along the lifting support column 20.

[0078] With this configuration, when the lifting unit 2 is in the extended position P2, the transfer plate 27 is stretched from the upper end of the cross member 25 to the loading platform 101 (see Figure 15), which prevents the cargo from getting stuck between the cross member 25 and the loading platform 101 when moving the cargo between the receiving platform 24 and the loading platform 101. For example, when a drum filled with liquid is loaded or unloaded onto the loading platform 101 by rolling it on its side, the transfer plate 27 allows the drum to move smoothly between the receiving platform 24 and the loading platform 101 without getting caught.

[0079] Furthermore, when the lifting unit 2 is in the retracted position P1, the connecting plate 27 is positioned along the lifting support column 20, so it does not get in the way (see Figure 11).

[0080] Furthermore, since the connecting plate 27 is a flat plate without holes or other openings, it prevents objects from falling through the gap between the cross member 25 and the cargo bed 101 when loading or unloading cargo onto the cargo bed 101.

[0081] Furthermore, in the loading platform lifting device 1 of this embodiment, the lifting unit (lifting section) 2 has a step 28 positioned on the lifting support column 20 (more specifically, the outer column 21) so that its posture can be changed between a hoisted position along the lifting support column 20 (a position shown by the solid line of reference numeral 28 in Figure 7) and a protruding position where it protrudes from the lifting support column 20 (a position shown by the dashed line of reference numeral 28 in Figure 7).

[0082] With this configuration, workers can easily get on and off the loading platform 101 by placing their feet on the step 28 in a protruding position. Moreover, when the step 28 is not in use, it can be retracted so that it does not get in the way.

[0083] It should be noted that the load-receiving platform lifting device of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. For example, the configuration of one embodiment can be added to the configuration of another embodiment, and a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Furthermore, a part of the configuration of one embodiment can be deleted.

[0084] In the loading platform lifting device 1 of the above embodiment, the reciprocating section (reciprocating unit) 3 moves the lifting section (lifting unit) 2 between the retracted position P1 and the extended position P2 by the swinging motion of the link mechanism R, but the configuration is not limited to this. The reciprocating section 3 may also be configured to move (slide, etc.) the lifting section 2 between the retracted position P1 and the extended position P2 in a linear direction, such as horizontally.

[0085] Furthermore, the forward / backward section 3 may be configured to combine multiple movements, such as moving the lifting section 2 linearly, like by sliding, and then moving it by oscillating when moving it from the retracted position P1 to the advanced position P2.

[0086] Furthermore, in the above embodiment of the loading platform lifting device 1, the lifting support column 20 is configured to extend and retract by two members (the inner column 22 moves back and forth relative to the outer column 21), but it is not limited to this configuration. The lifting support column 20 may be configured to extend and retract by three or more members. Alternatively, the lifting support column 20 may be configured not to extend or retract.

[0087] Furthermore, although the loading platform 24 in the above embodiment is composed of two plate-shaped members (main plate 241 and sub-plate 242), it may be composed of one plate-shaped member, or of three or more plate-shaped members.

[0088] Furthermore, in the above embodiment, the loading platform 24 can be manually changed between the deployed position and the upright storage position, but this may be done automatically.

[0089] Furthermore, although the connecting member (connecting plate) 27 in the above embodiment is a plate-shaped member with a flat surface without holes on its upper surface, holes or irregularities (such as protrusions) may be formed on the upper surface, as long as the shape prevents the load from getting stuck when it is rolled between the receiving platform and the loading platform.

[0090] Furthermore, although the transfer member 27 in the above embodiment changes its orientation between the first and second orientations by rotation, it may also be configured to change its orientation by other means of movement. That is, the transfer member 27 may change its orientation in conjunction with the movement (advancing and retreating) of the lifting unit 2.

[0091] Furthermore, although the left-right dimension of the loading platform lifting device 1 in the above embodiment is smaller than the left-right dimension of the loading platform, it may be the same or approximately the same.

[0092] Furthermore, although the loading platform lifting device 1 in the above embodiment is located above the tailgate 103 and inside the tailgate 103 (towards the front of the vehicle), the configuration is not limited to this. The loading platform lifting device 1 may have a portion that protrudes above the tailgate 103 and outside the tailgate 103 (towards the rear of the vehicle, etc.).

[0093] Furthermore, in the above embodiment of the loading platform lifting device 1, the loading platform 24 moves up and down in the height direction between the position of the floor surface 101a of the loading platform 101 (up position P11) and the position of the ground (down position P12), but the device is not limited to this configuration. The loading platform 24 may be configured to rise to a position above the floor surface 101a of the loading platform 101. In this case, the loading platform 24 may be configured to rise to a position above the floor surface 101a of the loading platform 101 by raising the slider 23 on the lifting support column 20, or the loading platform 24 may be configured to rise to a position above the floor surface 101a of the loading platform 101 by raising the lifting support column 20 from the loading platform 101 position due to the operation of the link mechanism R of the reciprocating section 3. [Explanation of symbols]

[0094] 1...Loading platform lifting device, 2...Lifting unit (lifting section), 20...Lifting support column, 21...Outer column, 21a...Slit, 21k...Lower end, 22...Inner column, 22a...Slit, 22k...Lower end, 23...Slider, 232...Rear of slider, 233...Bracket, 24...Loading platform, 24a...Loading surface, 241...Main plate, 241a...Pin, 242...Subplate, 243...Hinge, 25...Cross member, 25a...Top surface, 251...Reinforcement member, 2 6...Lifting mechanism, 261...Hydraulic cylinder, 262...Fixed sheave, 263...Movable sheave, 27...Transfer plate (blocking member), 271...Hinge, 28...Step, 281...Base, 282...Footrest, 283...Footrest body, 284...Extended part, 3...Advancing / retracting unit (advancing / retracting part), 31...Base, 311...Base body, 312...Fixing part, 313...Upright part, 315...Support part, 315a...Front edge, 315b...Rear edge, 32...Lift arm, 32a...Front end, 3 2b...rear end, 321, 322...support shaft, 33...compression arm, 33a...front end, 33b...rear end, 331, 332...support shaft, 335...cylinder insertion hole, 34...cylinder, 341...cylinder tube, 341b...support shaft, 342...rod, 342b...support shaft, 35...power unit, 5...control panel, 51...forward / backward switch, 52...lift / lower switch, 100...cargo vehicle, 101...cargo bed, 101a...floor surface, 102...side wall, 103...side door, 50 0...Loading platform lifting device, 501...Loading platform floor, 502...Guide rail, 503...Second floor, 504...Guide member, 510...Support, 511...Fixing bracket, 512...Link, 512a, 512b...Axle support, 513...Link, 520...Lifting section, 521...Loading platform, 522...Outer cylinder, B...Elastic member, C...Cargo vehicle, P1...Retracted position, P2...Extended position, P11...Raised position, P12...Lowered position, P51...Retracted position, P52...Extended position, R...Link mechanism

Claims

1. A loading platform lifting device that can be installed on the loading platform of a vehicle, It has a loading platform on which cargo can be placed and a vertically extending lifting support column, and a lifting section that raises and lowers the loading platform along the lifting support column, The lifting mechanism, when positioned on the aforementioned loading platform, is provided with a retractable mechanism that allows it to move back and forth between a retracted position on the loading platform and an extended position outside the edge of the loading platform in a plan view, A loading platform lifting device, wherein when the lifting part is in the retracted position, the lower end of the lifting part is located above the loading platform and inward from the edge of the loading platform in a plan view.

2. The aforementioned reciprocating section includes a cylinder that extends and retracts in accordance with the reciprocating movement of the lifting section. The loading platform lifting device according to claim 1, wherein the cylinder is retracted when the lifting section is in the extended position.

3. The aforementioned lifting mechanism is When in the aforementioned extended position, a cross member is located between the loading platform and the loading platform in a plan view, and its upper end extends along the edge of the loading platform with a gap between it and the loading platform, The cross member is attached to the cross member so as to be rotatable about an axis extending in the same direction as the upper end of the cross member, The loading platform lifting device according to claim 1 or 2, wherein the connecting member rotates with the advancement and retraction of the lifting section, so that when the lifting section is in the advanced position, it is in a first position where it is stretched from the upper end of the cross member to the loading platform, and when the lifting section is in the retracted position, it is in a second position along the lifting support column.

4. The lifting mechanism has a step positioned on the lifting support column so as to be able to change its orientation between a housing position along the lifting support column and a protruding position protruding from the lifting support column, according to claim 1 or 2.

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