JP7309267B2 - Loading table lifting device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load-receiving platform lifting device that lifts and lowers a load-receiving platform to support loading and unloading work on the loading platform of a vehicle.

A loading platform lifting device is a device that lifts and lowers a loading platform between the height of the floor surface of the loading platform of a vehicle and the height of the ground, thereby assisting loading and unloading of cargo onto and from the loading platform of the vehicle. This type of loading platform lifting device is generally driven by power supplied from a battery via a fuse (see Patent Document 1, etc.).

Japanese Patent No. 5271642

A fuse box containing fuses of a loading platform lifting device may be installed on a vehicle frame (chassis frame) as described in Japanese Patent Application Laid-Open No. 2002-200012. In general, this type of fuse box is provided with bolts for fixing terminals. The bolt is fixed to the fuse box with its head surrounded by molding resin. The electric wiring is connected to the fuse by overlapping the electric wiring and the terminal of the fuse on the bolt and tightening the nut.

However, if the nut is strongly tightened when connecting the terminals, the mold resin surrounding the bolt head and the fuse box may crack. If the fuse box is cracked and the frame is wet, water can enter the cracks and cause a short circuit.

SUMMARY OF THE INVENTION An object of the present invention is to provide a loading platform lifting device capable of suppressing the occurrence of a short circuit when a crack occurs in a fuse box.

In order to achieve the above object, the present invention provides a loading platform lifting device for lifting and lowering a loading platform between the height of the floor of a loading platform of a vehicle and the height of the ground, in which bolts for fixing electrical wiring terminals are provided inside. wherein the fuse box has a leg projecting downward, the fuse box is fixed to the vehicle frame via the leg, and the head of the bolt extends into the fuse box is fixed to the floor surface of the load receiving platform, and a gap is interposed between the upper surface of the vehicle frame and the head of the bolt, in which there is no substance other than the atmosphere secured by the leg portion do.

ADVANTAGE OF THE INVENTION According to this invention, generation|occurrence|production of a short circuit when the fuse box of a load-receiving board raising/lowering apparatus cracks can be suppressed.

1 is a side view showing the overall structure of a vehicle equipped with a load receiving platform lifting device according to an embodiment of the present invention; The side view which expands and expresses the load-receiving stand raising/lowering apparatus of FIG. Hydraulic circuit diagram showing one configuration example of a power unit provided in the loading platform lifting device of FIG. Electric circuit diagram mainly showing the power supply circuit of the power unit provided in the loading platform lifting device of FIG. External view of the fuse box provided in the loading platform lifting device of Fig. 1 A plan view of the state where the cover of the fuse box of FIG. 5 is opened Cross-sectional view taken along line VII-VII in Fig. 6 6 is a perspective view showing the internal structure of the base of the fuse box of FIG. 5; FIG. 6 is a perspective view showing the bottom structure of the base of the fuse box of FIG. 5; FIG.

Embodiments of the present invention will be described below with reference to the drawings.

－Loading tray lifting device－
FIG. 1 is a side view showing the overall structure of a vehicle equipped with a load receiving platform lifting device according to an embodiment of the present invention, and FIG. 2 is an enlarged side view showing the load receiving platform lifting device of FIG. In the specification of the present application, the left and right sides in FIGS. This embodiment exemplifies the case where the load-receiving table lifting device is loaded on the rear part of the vehicle and the load-receiving table lifting device is pulled out to the rear side of the vehicle. However, there are cases in which the load-receiving table lifting device is loaded on the side of the vehicle so that the load-receiving table is pulled out. In that case, the front-rear direction of the load-receiving table lifting device is perpendicular to the front-rear direction of the vehicle.

The vehicle shown in FIG. A loading platform L is mounted on the upper part of the frame F. A cargo box is also a type of carrier. In this embodiment, the loading platform lifting device 1 is mounted on the rear lower side of the vehicle frame F. As shown in FIG. For example, when the vehicle is running, the load receiving platform (platform) 20 of the load receiving platform lifting device 1 is folded and retracted to the lower side of the vehicle frame F for storage. On the other hand, during loading/unloading work (loading/unloading work on/from the loading platform), the loading platform 20 is pulled out to the outside (rear in this embodiment) of the vehicle frame F, and is raised and lowered between the floor level of the loading platform and the ground level. (Fig. 1).

As shown in FIG. 2, the load receiving platform lifting device 1 includes a load receiving platform 20, a slider unit (not shown), a lifter unit 40 and a power unit 50 (FIG. 3). The slider unit is a unit including an actuator for moving the load receiving table 20 and the like in the front-rear direction. The lifter unit 40 is a unit including an actuator for raising and lowering the load receiving table 20 . A power unit 50 is a system that drives the slider unit and lifter unit 40 . The slider unit, lifter unit 40, load receiving table 20 and power unit 50 will be described in order.

－Slider unit－
The slider unit includes left and right guide rails 31, a slider (not shown), and a slide cylinder 33 (FIG. 3). The left and right guide rails 31 are attached to the rear lower side of the vehicle frame F and extend forward and backward in parallel with each other. The slider is slidably attached to the left and right guide rails 31 and can move back and forth along the guide rails 31 . The slide cylinder 33 is a double-acting hydraulic cylinder, and both ends thereof are fixed to the guide rail 31 and the slider via appropriate supporting members. The extension and contraction of the slide cylinder 33 moves the slider back and forth along the guide rail 31, and the load receiving table 20 supported by the slider via the lifter unit 40 moves back and forth.

－Lifter unit－
The lifter unit 40 includes a set of left and right tilt arms (not shown), lift arms 42, compression arms 43, and lift cylinders 44, respectively. The upper part of the tilt arm is connected to the slider via a pin, and the lower part of the tilt arm rotates back and forth. The lift arm 42 is rotatably connected at its front end to the tilt arm and at its rear end to the load receiving platform 20 via a laterally extending shaft. move. The compression arm 43 is rotatably connected at its front end to the slider and at its rear end to the load receiving platform 20 via shafts extending laterally. The lift cylinder 44 is a single-acting hydraulic cylinder (or a double-acting type), and in this embodiment, the rod side is rotatably connected to the lower portion of the tilt arm, and the bottom side is rotatably connected to the lift arm 42 . The lift arm 42 and compression arm 43 form parallel links that hoistably connect the load cradle 20 to the slider. When the parallel link is driven to rotate up and down in accordance with the expansion and contraction of the lift cylinder 44, the load receiving table 20 moves up and down while maintaining a horizontal posture (FIG. 1).

－Receiving table－
The load-receiving table 20 is a table that moves up and down for receiving loads, etc. A base-side load-receiving table 21 is connected to the ends of a lift arm 42 and a compression arm 43, and a hinge (not shown) is attached to the rear part of the base-end-side load receiving table 21. It is provided with a tip side load receiving base 22 rotatably connected via. The tip side load receiving tray 22 rotates about the hinge, and is reversed counterclockwise (rotated 180 degrees) in a left side view from the unfolded posture (two-dot chain line in FIG. 1) to open the base end side load receiving tray 21. It is folded upwards (Fig. 2). A rear end face of the load receiving platform 20 in a folded state constitutes a bumper. The left and right widths of the load receiving platform 20 are approximately the same as the width of the loading platform L, for example, and are wider than the outer dimensions of the left and right vehicle frames F. The tip side load receiving tray 22 of this embodiment is non-foldable. That is, the load-receiving table 20 has a two-fold structure including only one front end-side load-receiving table 22 . A pair of left and right stiffeners 24 are provided at the lower portion of the load receiving table 20 . The stiffeners 24 are provided on the base end side load receiving base 21 and the tip end side load receiving base 22, and when the load receiving base 20 is unfolded, the stiffeners 24 provided on the base end side load receiving base 21 and the ones provided on the tip end side load receiving base 22 are connected, When viewed from the left and right, it has a triangular shape that tapers from the base to the tip (rear).

－Power unit－
FIG. 3 is a hydraulic circuit diagram showing one configuration example of the power unit 50. As shown in FIG. A power unit 50 shown in the figure includes an electric motor M, a hydraulic pump P1, an oil tank T, switching valves V1 to V4, and a control computer 60 (FIG. 4). The hydraulic pump P1 is driven by an electric motor M, and discharges hydraulic oil sucked from an oil tank T into a pump line PL as pressure oil. The pressure oil discharged from the hydraulic pump P1 is supplied to the lift cylinder 44 through the hydraulic piping L1. The hydraulic pipe L1 is provided with a switching valve V1 for upward movement, and the switching valve V1 is opened or closed by a signal input to the solenoid S1 to open or shut off the hydraulic pipe L1. A hydraulic pipe L2 branches off from the hydraulic pipe L1 between the pump line PL and the switching valve V1, and is connected to the oil tank T via the tank line TL. The hydraulic pipe L2 is provided with a switching valve V2 for lowering operation, and the switching valve V2 is opened and closed by a signal input to the solenoid S2 to open or shut off the hydraulic pipe L2. A flow control valve V9 is provided downstream of the switching valve V2 in the hydraulic pipe L2. A main relief valve V6 is provided in the pump line PL, and the maximum value of the pressure of the pump line PL is regulated by the main relief valve V6. A contactor relay CT1 is provided between the electric motor M and the battery BT (FIG. 4).

The pump line PL also connects to the rod port of the slide cylinder 33 via the hydraulic line L3. A throttle valve V8 is provided in the hydraulic pipe L3. A hydraulic pipe L4 branches off from the hydraulic pipe L3 and is connected to the bottom port of the slide cylinder 33 . The hydraulic pipe L4 is provided with a switching valve V3 for pull-out operation, and the switching valve V3 is opened or closed by a signal input to the solenoid S3 to open or shut off the hydraulic pipe L4. A hydraulic pipe L5 branches off from the hydraulic pipe L4 on the downstream side of the switching valve V3 and is connected to the oil tank T via the tank line TL. The hydraulic pipe L5 is provided with a switching valve V4 for retraction operation, and the switching valve V4 is opened or closed by a signal input to the solenoid S4 to open or shut off the hydraulic pipe L5.

In this embodiment, a bypass line BL branches from the pump line PL between the main relief valve V6 and the switching valves V3 and V4 and connects to the tank line TL. This bypass line BL is provided with a sub-relief valve V7 and a switching valve V5. The switching valve V5 switches its switching position to an open position (upper position in the figure) or a shutoff position (lower position in the figure) according to a command signal to the solenoid S5. The switching position of the switching valve V5 opens or blocks the flow of pressure oil to the sub-relief valve V7. Although the switching valve V5 is provided on the upstream side of the sub-relief valve V7, it may be provided on the downstream side. The relief pressure (for example, about 6 MPa) of the sub-relief valve V7 is set lower than the relief pressure (for example, about 20 MPa) of the main relief valve V6. When the switching valve V5 is switched to the open position and the sub-relief valve V7 is connected to the pump line PL, the maximum value of pressure oil in the pump line PL is switched to a value lower than the relief pressure of the main relief valve V6.

FIG. 4 is an electric circuit diagram mainly showing the power supply circuit of the power unit 50. As shown in FIG. The control computer 60 is a device that controls the power unit 50 and is driven by power supplied from the battery BT. For example, when a command signal is output from the control computer 60 to the contactor relay CT1, the electric motor M is connected to the battery BT via the contactor relay CT1 and driven. Signal output lines for solenoids S1-S5 of switching valves V1-V5 are omitted from the drawing. As shown in FIG. 4, electric motor M and control computer 60 are connected to battery BT through fuses F1 and F2. The fuses F1 and F2 are housed in a fuse box 70 and installed, for example, on the upper surface of the frame F of the vehicle. In this embodiment, the fuse box 70 accommodates the contactor relay CT2 together with the fuses F1 and F2. The contactor relay CT2 is interposed between the fuse F1 and the contactor relay CT1, and opens and closes its contacts according to command signals from the control computer 60, like the contactor relay CT1.

-Fuse box-
5 is an external view of the fuse box 70, FIG. 6 is a plan view of the fuse box 70 with the cover opened, and FIG. 7 is a cross-sectional view taken along line VII--VII in FIG. 8 is a perspective view showing the internal structure of the base of the fuse box 70, and FIG. 9 is a perspective view showing the bottom structure of the base. In FIGS. 5 to 9, elements that have already been described in the drawings already described are given the same reference numerals as in the drawings already described, and the description thereof will be omitted as appropriate.

The fuse box 70 comprises a base 71 and a cover 72, and accommodates fuses F1, F2, contactor relay CT2, bolts 73, 74 and brackets 75, 76 inside.

The base 71 is a container-like member made of resin and has a rectangular shape when viewed from above. A pedestal 79 (FIG. 8) for the contactor relay CT2 is formed in the central portion of the floor surface of the base 71. As shown in FIG. A lower portion of the contactor relay CT2 is fitted in the base 79 (FIG. 7). A total of two bolts 73 and 74 are fixed to the base 71 , one on each side in the longitudinal direction with the pedestal 79 interposed therebetween. Notches 77 and 78 are provided on both side walls of the base 71 in the longitudinal direction.

The bolts 73 and 74 are parts for fixing and connecting the terminals, and are general metal bolts. The heads of these bolts 73 and 74 are fixed to the floor surface of the base 71 with their tips directed upward in this embodiment. The heads of the bolts 73 and 74 are covered with a mold resin 81, and fixed to the floor surface of the base 71 via the mold resin 81 (FIG. 8). The brackets 75 and 76 are U-shaped metal fittings having through holes 82 at both ends. One bolt 73 is overlapped with a terminal of the electrical wiring E1 connected to the battery BT (FIG. 4) and one through hole 82 (not shown) of the bracket 75, and a nut 83 is tightened. The electric wiring E1 is connected from the battery BT to the interior of the fuse box 70 through the notch 77 described above. The other bolt 74 is overlapped with the terminal of the electrical wiring E2 connected to the contactor relay CT1 (FIG. 4) and one through hole 82 of the bracket 76, and a nut 84 is tightened. The electric wiring E2 is connected to the interior of the fuse box 70 from the contactor relay CT1 through the notch 78 described above.

One side (lower side) of the brackets 75 and 76 is fixed to the bolts 73 and 74 by the nuts 83 and 84 as described above, and the other side (upper side) of the bracket 75 and 76 has a through hole 82 which is approximately the same as the upper portion of the contactor relay CT2. located at height. One terminal of the fuse F1 is overlaid on the other side of the bracket 75 and connected with a bolt B1 and a nut N1. The other terminal of the fuse F1 overlaps the one terminal of the electric wiring E3 and covers the primary terminal T1 of the contactor relay CT1, and is fixed with a nut N3. The other terminal of the electrical wiring E3 is connected to the power port of the control computer 60 via the fuse F2 and the electrical wiring E4. A terminal T2 on the secondary side of the contactor relay CT1 is fixed to the other (upper side) of the bracket 76 with a nut N4.

Then, as shown in FIG. 7, the cover 72 is attached to the base 71 in which the contactor relay CT2, the fuses F1 and F2, and necessary electric wiring E1-E5 are installed. As a result, the contactor relay CT2, the fuses F1 and F2, and the terminal portions of the electric wires E1 to E5 are housed in the fuse box 70. FIG. Even if the cover 72 is attached to the base 71, the entirety of the cover 72 is located above the lower end of the base 71. The fuse box 70 is grounded to the vehicle frame F only at the base 71, and the cover 72 has a grounding portion to the vehicle frame F. do not have.

4, the battery BT is first connected to the electric motor M via the electrical wiring E1, the bracket 75, the fuse F1, the contactor relay CT2, the bracket 76, the electrical wiring E2 and the contactor relay CT1. Battery BT is also connected to control computer 60 via bracket 75, fuse F1, electrical wire E3, fuse F2 and electrical wire E4. The contactor relay CT2 is connected to the control computer 60 and ground through electrical wires E5 and E6, and the contactor relay CT1 is connected to the control computer 60 and ground through electrical wires E7 and E8. As a result, when the contactor relays CT1 and CT2 are excited by the electric signal from the control computer 60, the electric motor M is driven by power supply from the battery BT.

As a significant feature of this embodiment, the fuse box 70 is provided with at least one leg 85 (two in this embodiment). Two leg portions 85 are provided, one on each side in the longitudinal direction of the base 71 of the fuse box 70 , and protrude downward from the bottom surface (lower surface) of the base 71 . In this embodiment, the legs 85 formed in the shape of sleepers are exemplified, but the shape can be changed in design. The leg portion 85 may be a separate member attached to the base 71 , but is assumed to be a part of the base 71 in this embodiment. That is, the base 71 including the leg portion 85 is integrally molded of resin. The leg portion 85 is provided with a through hole 86 through which a bolt (not shown) for fixing to the vehicle frame F is passed through. It is fixed to the upper surface of the frame F of the vehicle. Since the base 71 has a raised-floor structure in this manner, a gap G is provided between the fuse box 70 and the vehicle frame F by the legs 85 . The bolts 73 and 74 are provided above the gap G (between the two legs 85) on the base 71, and the gap G is between the upper surface of the frame F and the heads of the bolts 73 and 74. Intervene. In other words, the base 71 is configured so that the bolts 73, 74 and the leg 85 do not overlap in the horizontal direction (so that the bolts 74, 75 and the leg 85 do not overlap when viewed from above). The interposition of the gap G does not comprehensively mean a state in which the main body of the fuse box 70 and the vehicle frame F are physically separated, but rather that there is an atmosphere between the main body of the fuse box 70 and the vehicle frame F. It means that there is a space in which no other substances exist. That is, the fuse box 70 is grounded to the vehicle frame F only by the leg portion 85, and the portion of the fuse box 70 other than the leg portion 85 is in a non-contact relationship with the vehicle frame F, either directly or indirectly through some structure. It is the structure which does not contact the vehicle frame F also.

In this embodiment, since the molded resin 81 that restrains the heads of the bolts 73 and 74 exists inside the fuse box 70 , the gap G naturally exists between the upper surface of the vehicle frame F and the molded resin 81 . However, for example, the base 71 may be formed into a shape having holes through which the bolts 73 and 74 pass, and the bolts 73 and 74 may be inserted into the base 71 from below and fixed. In this case as well, the heads of the bolts 73 and 74 need to be surrounded by the molding resin 81 for insulation, but the heads of the bolts 73 and 74 and the molding resin 81 are positioned below the base 71 . Even if the head portions of the bolts 73 and 74 and the molded resin 81 are positioned below the base 71 in this manner, the gap G is interposed between the upper surface of the vehicle frame F and the molded resin 81 by the leg portion 85 . configured to

-motion-
In FIG. 3, switching valves V1-V5 are all normally closed type switching valves, and are closed in the demagnetized state. Based on this state, when the contactor relay CT1 is excited by an electric signal from the control computer 60, the electric motor M and the hydraulic pump P1 are driven by power supply from the battery BT. When the solenoid S3 is energized by an electric signal from the control computer 60 when the hydraulic pump P1 is driven, the switching valve V3 opens and pressure oil is supplied to the rod port and bottom port of the slide cylinder 33 from the hydraulic pump P1. As a result, the slide cylinder 33 is extended due to the pressure receiving area difference, and the load receiving base 20 is moved backward (for example, pulled out from the lower portion of the vehicle frame F).

When the solenoid S4 is energized by an electric signal from the control computer 60 when the hydraulic pump P1 is driven, the switching valve V4 opens and pressure oil is supplied to the rod port of the slide cylinder 33 from the hydraulic pump P1. As a result, the slide cylinder 33 is contracted, and the load receiving table 20 is moved forward (for example, pulled into the lower part of the vehicle frame F).

When the solenoid S2 is energized by an electric signal from the control computer 60 when the hydraulic pump P1 is stopped, the switching valve V2 is opened and the bottom port of the lift cylinder 44 is connected to the oil tank T. As a result, the lift cylinder 44 contracts due to the weight of the load receiving table 20 and the like, and the load receiving table 20 descends.

When the solenoid S1 is energized by an electric signal from the control computer 60 when the hydraulic pump P1 is driven, the switching valve V1 opens and pressure oil is supplied to the bottom port of the lift cylinder 44 from the hydraulic pump P1. As a result, the lift cylinder 44 is extended and the load receiving table 20 is lifted.

-effect-
In this embodiment, as described above, the fuse box 70 is provided with the leg portion 85 so that the gap G is interposed between the bolts 73 and 74 and the mold resin 81 and the vehicle frame F. As shown in FIG. Since the mold resin 81 is separated from the vehicle frame F, the mold resin 81 does not come into contact with water even if water runs down the surface of the vehicle frame F due to rainfall or the like. For example, even if the nuts 83 and 84 are tightened too tightly when fixing the terminals to the bolts 73 and 74 and the mold resin 81 and the base 71 are cracked, water on the frame F can be prevented from entering the cracks. Therefore, it is possible to suppress the occurrence of a short when the fuse box 70 is cracked.

-Modification-
In the above embodiment, the head portions of the bolts 73 and 74 are covered with the mold resin 81, but the bolts 73 and 74 do not necessarily need to be covered with the mold resin. For example, even in a structure in which the bolts 73 and 74 are directly fixed to the base 71 by screwing or fitting and the heads of the bolts 73 and 74 are exposed, the legs 85 are provided between the heads of the bolts 73 and 74 and the vehicle frame F. It suffices if the gap G is ensured by With such a configuration, it is possible to suppress the occurrence of a short due to the bolts 73 and 74 coming into contact with the water on the surface of the vehicle frame F. In addition, the bolts 73 and 74 are set in the mold of the base 71 of the fuse box 70 and the resin is poured into the mold. 74 may be configured integrally. In this case also, it is not necessary to cover the heads of the bolts 73 and 74 with molding resin after the base 71 is molded.

Further, in the above-described embodiment, the front end side load receiving stand 22 is one piece and the load receiving stand 20 is bent at one point. A structure in which 20 is broken at two or more points may be employed. The fuse box 70 configured as described above can also be applied to a load receiving table lifting device employing such a load receiving table. Further, if the load receiving table can be stored in the lower portion of the vehicle frame F simply by pulling it in with the slide cylinder 33 without folding, the folding mechanism itself for the load receiving table 20 can be omitted. The fuse box 70 can also be applied to a load-receiving table lifting device employing such a load-receiving table.

In addition, the present invention can also be applied to other types of load receiving platform elevating devices that support cargo handling work by elevating the load receiving platform between the ground and the loading platform, for example. For example, the present invention can also be applied to a load-receiving stand lifting device (for example, JP-A-2010-155600, JP-A-2005-289150) that accommodates a load-receiving stand inside a packing box. The present invention can also be applied to a rotating retractable load receiving platform lifting device (see Japanese Patent Application Laid-Open No. 2010-52569) that rotates the load receiving platform upward without sliding it and stores it in the lower portion of the vehicle frame. In addition, it can also be applied to various load-receiving platform lifting devices (for example, Japanese Patent Application Laid-Open Nos. 2008-189189, 2007-331631, and 2004-224082) that store the load-receiving platform upright at the rear of the loading platform. is.

DESCRIPTION OF SYMBOLS 1... Loading platform lifting device, 20... Loading platform, 70... Fuse box, 73, 74... Bolt, 81... Mold resin, 85... Leg part, F... Vehicle frame, G... Gap, L... Loading platform

Claims (3)

In a loading platform lifting device that lifts and lowers the loading platform between the height of the floor of the loading platform of a vehicle and the height of the ground,
Equipped with a fuse box having bolts for fixing terminals of electrical wiring inside,
The fuse box is provided with a leg projecting downward, and the fuse box is fixed to a frame of the vehicle via the leg,
the head of the bolt is fixed to the floor of the fuse box,
A load-receiving table lifting device, wherein a gap is provided between the upper surface of the vehicle frame and the head of the bolt, in which there is no substance other than the atmosphere secured by the leg. 2. The load receiving platform lifting device according to claim 1, wherein the head of said bolt is covered with molded resin, and said gap is interposed between the upper surface of said car frame and said molded resin. 2. The load-receiving table lifting device according to claim 1, wherein the head of said bolt is embedded in said fuse box so that said fuse box and said bolt are integrated.

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