JP2020157814A - Load receiving platform lifting apparatus - Google Patents

Abstract

To inhibit the occurrence of a short circuit when a crack appears in a fuse box.SOLUTION: A load receiving platform lifting apparatus, which lifts/lowers a load receiving platform between a floor surface level of a loading platform of a vehicle and a ground level, comprises a fuse box internally having a bolt for fixing a terminal. The fuse box is provided with a leg protruding downward. The fuse box is fixed to a frame of the vehicle via the leg. A clearance secured by the leg is interposed between a top surface of the frame and a head of the bolt.SELECTED DRAWING: Figure 7

Description

The present invention relates to a loading platform lifting device that raises and lowers the loading platform to support cargo handling work on the loading platform of a vehicle.

The loading platform lifting device is a device that raises and lowers the loading platform between the height of the floor surface of the loading platform of the vehicle and the height of the ground to support the loading and unloading work of luggage and the like on the loading platform of the vehicle. This type of loading platform elevating device is generally driven by electric power supplied from a battery via a fuse (see Patent Document 1 and the like).

Japanese Patent No. 5271642

The fuse box containing the fuse of the load receiving platform elevating device may be installed on the chassis frame of the vehicle as described in Patent Document 1. Generally, a bolt for fixing a terminal is provided inside this type of fuse box. The bolt is fixed to the fuse box with its head surrounded by mold resin. The electrical wiring and the fuse terminal are overlapped on this bolt, and the nut is tightened to connect the electrical wiring to the fuse.

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

An object of the present invention is to provide a loading platform elevating device capable of suppressing the occurrence of a short circuit when a fuse box is cracked.

In order to achieve the above object, the present invention has a bolt internally for fixing a fuse terminal in a loading platform lifting device that raises and lowers the loading platform between the height of the floor surface of the loading platform of the vehicle and the height of the ground. A fuse box is provided, and the fuse box is provided with a leg portion protruding downward, and the fuse box is fixed to the vehicle frame of the vehicle via the leg portion, and the upper surface of the vehicle frame and the head of the bolt Provided is a load receiving platform elevating device in which a gap secured by the legs is interposed between the two.

According to the present invention, it is possible to suppress the occurrence of a short circuit when the fuse box of the load receiving platform elevating device is cracked.

A side view showing the overall structure of a vehicle equipped with a load receiving platform elevating device according to an embodiment of the present invention. Side view of the loading platform lifting device of FIG. 1 in an enlarged manner. A hydraulic circuit diagram showing a configuration example of a power unit provided in the load receiving platform elevating device of FIG. An electric circuit diagram showing mainly a power supply circuit of a 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. Top view of the fuse box shown in FIG. 5 with the cover open. Cross-sectional view taken along the line VII-VII in FIG. A perspective view showing the internal structure of the base of the fuse box of FIG. A perspective view showing the bottom structure of the base of the fuse box of FIG.

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

-Load receiving platform 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 loading platform lifting device of FIG. In the specification of the present application, the left and right sides in FIGS. 1 and 2 are the front and back of the load receiving platform elevating device. In this embodiment, a case where the load receiving platform lifting device is loaded on the rear part of the vehicle and the loading platform is pulled out to the rear side of the vehicle is illustrated, and the front-rear direction of the loading platform lifting device coincides with the front-rear direction of the vehicle. However, in some cases, the loading platform lifting device is loaded on the side of the vehicle so as to pull out the loading platform. In that case, the front-rear direction of the load receiving platform elevating device is orthogonal to the front-rear direction of the vehicle.

The vehicle shown in FIG. 1 includes a vehicle frame F and a driver's cab C provided in front of the vehicle frame F. A loading platform L is mounted on the upper part of the vehicle frame F. A packing box is also a kind of loading platform. In the present embodiment, the load receiving platform elevating device 1 is loaded on the lower rear side of the vehicle frame F. For example, when the vehicle is traveling, the load receiving platform lifting device 1 folds the loading platform (platform) 20 and pulls it under the vehicle frame F to store it. On the other hand, during cargo handling work (loading and unloading of luggage with respect to the loading platform), the loading platform 20 is pulled out to the outside of the vehicle frame F (rearward in the present embodiment) and deployed, and is raised and lowered between the floor height and the ground height of the loading platform. (Fig. 1).

As shown in FIG. 2, the load receiving platform elevating device 1 includes a loading 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 that moves the load receiving base 20 and the like in the front-rear direction. The lifter unit 40 is a unit including an actuator that raises and lowers the load receiving base 20. The power unit 50 is a system that drives the slider unit and the lifter unit 40. The slider unit, the lifter unit 40, the load receiving base 20, and the 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 lower rear side of the vehicle frame F, and extend back and forth in parallel with each other. The slider is slidably attached to the left and right guide rails 31 and can be moved back and forth along the guide rails 31. The slide cylinder 33 is a double-acting hydraulic cylinder, and both ends are fixed to the guide rail 31 and the slider via appropriate support members. The expansion and contraction operation of the slide cylinder 33 causes the slider to move back and forth along the guide rail 31, and the load receiving base 20 supported by the slider moves back and forth via the lifter unit 40.

-Lifter unit-
The lifter unit 40 includes a tilt arm (not shown), a lift arm 42, a compression arm 43, and a lift cylinder 44, one on each side. The upper part of the tilt arm is connected to the slider via a pin, and the lower part rotates back and forth. The lift arm 42 is rotatably connected to the tilt arm at the front end and to the loading platform 20 at the rear end via a shaft extending to the left and right, and rotates up and down with respect to the slider and the loading platform L of the vehicle. Move. The compression arm 43 is rotatably connected to the slider at the front end and to the load receiving platform 20 at the rear end via a shaft extending to the left and right. The lift cylinder 44 is a single-acting hydraulic cylinder (may be a double-acting type), and in the present embodiment, the rod side is rotatably connected to the lower part of the tilt arm and the bottom side is rotatably connected to the lift arm 42. The lift arm 42 and the compression arm 43 form a parallel link that connects the loading platform 20 to the slider so as to be able to move up and down. The parallel link is driven to rotate up and down as the lift cylinder 44 expands and contracts, so that the load receiving table 20 moves up and down while maintaining a horizontal posture (FIG. 1).

− Cargo stand −
The load receiving table 20 is a table that raises and lowers by receiving luggage and the like, and has hinges (not shown) at the rear portions of the base end side load receiving table 21 and the base end side loading platform 21 connected to the tips of the lift arm 42 and the compression arm 43. It is provided with a front end side load receiving table 22 that is rotatably connected via. The tip side cradle 22 rotates around the hinge as a fulcrum and reverses counterclockwise (turns 180 degrees) from the unfolded posture (two-dot chain line in FIG. 1) when viewed from the left side. It is folded upward (Fig. 2). The rear end surface of the cradle 20 in the folded state constitutes a bumper. The left and right widths of the loading platform 20 are, for example, about the same as the width of the loading platform L, which is wider than the outer dimensions of the left and right vehicle frames F. The front end side loading platform 22 of this embodiment is a non-foldable type. That is, the load receiving table 20 has a two-sheet folding structure including only one tip side load receiving table 22. Further, a pair of left and right stiffeners 24 are provided at the lower part of the load receiving table 20. The stiffener 24 is provided on the base end side cradle 21 and the tip end side cradle 22, and when the cradle 20 is deployed, the one provided on the base end side cradle 21 and the one provided on the tip end side cradle 22 are connected. When viewed from the left and right, it becomes a triangular shape that becomes thinner from the base end to the tip (rear).

-Power unit-
FIG. 3 is a hydraulic circuit diagram showing a configuration example of the power unit 50. The power unit 50 shown in the figure includes an electric motor M, a hydraulic pump P1, an oil tank T, a switching valve V1-V4, and a control computer 60 (FIG. 4). The hydraulic pump P1 is driven by the electric motor M, and the hydraulic oil sucked from the oil tank T is discharged to the pump line PL as pressure oil. The pressure oil discharged from the hydraulic pump P1 is supplied to the lift cylinder 44 via the hydraulic pipe L1. The hydraulic pipe L1 is provided with a switching valve V1 for ascending operation, and the switching valve V1 is opened and closed by a signal input to the solenoid S1 to open or shut off the hydraulic pipe L1. The hydraulic pipe L2 branches 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. The hydraulic pipe L2 is provided with a flow rate control valve V9 on the downstream side of the switching valve V2. Further, the pump line PL is provided with a main relief valve V6, and the maximum value of the pressure of the pump line PL is defined 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 is also connected to the rod port of the slide cylinder 33 via the hydraulic pipe L3. A throttle valve V8 is provided in the hydraulic pipe L3. The hydraulic pipe L4 is branched from the hydraulic pipe L3, and the hydraulic pipe L4 is connected to the bottom port of the slide cylinder 33. The hydraulic pipe L4 is provided with a switching valve V3 for a pull-out operation, and the switching valve V3 is opened and closed by a signal input to the solenoid S3 to open or shut off the hydraulic pipe L4. The hydraulic pipe L5 branches 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 pull-in operation, and the switching valve V4 is opened and closed by a signal input to the solenoid S4 to open or shut off the hydraulic pipe L5.

In the present embodiment, the bypass line BL branches from the pump line PL between the main relief valve V6 and the switching valves V3 and V4 and is connected to the tank line TL. The bypass line BL is provided with a sub-relief valve V7 and a switching valve V5. The switching position of the switching valve V5 is switched to the opening position (upper position in the figure) or the shutoff position (lower position in the figure) by the command signal to the solenoid S5. The flow of pressure oil to the sub-relief valve V7 is opened or cut off depending on the switching position of the switching valve V5. 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 of the sub-relief valve V7 (for example, about 6 MPa) is set lower than the relief pressure of the main relief valve V6 (for example, about 20 MPa). 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 the pressure oil of 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 showing mainly a power supply circuit of the power unit 50. The control computer 60 is a device that controls the power unit 50, and is driven by the electric 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. The signal output line for the solenoid S1-S5 of the switching valve V1-V5 is not shown. As shown in FIG. 4, the electric motor M and the control computer 60 are connected to the battery BT via fuses F1 and F2. The fuses F1 and F2 are housed in the fuse box 70 and are installed on, for example, the upper surface of the vehicle frame F of the vehicle. In the present embodiment, the contactor relay CT2 is housed in the fuse box 70 together with the fuses F1 and F2. The contactor relay CT2 is interposed between the fuse F1 and the contactor relay CT1, and like the contactor relay CT1, the contact is opened and closed by a command signal from the control computer 60.

-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 open, and FIG. 7 is a cross-sectional view taken along the 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. The elements described in the existing drawings are designated by the same reference numerals as those in the existing drawings in FIGS. 5 to 9, and the description thereof will be omitted as appropriate.

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

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

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

One of the brackets 75 and 76 (lower side) is fixed to the bolts 73 and 74 by nuts 83 and 84 as described above, and the through hole 82 on the other side (upper side) rises from the nuts 83 and 84 and is about the same as the upper part of the contactor relay CT2. Located at height. One terminal of the fuse F1 is superposed on the other side of the bracket 75, and is connected by a bolt B1 and a nut N1. The other terminal of the fuse F1 is placed on the terminal T1 on the primary side of the contactor relay CT1 so as to overlap with the terminal on one side of the electric wiring E3, and is fixed by the 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. Further, a terminal T2 on the secondary side of the contactor relay CT1 is fixed to the other side (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 the necessary electrical wirings E1-E5 are incorporated. As a result, the contact relay CT2, the fuses F1 and F2, and the terminal portions of the electrical wirings E1-E5 are housed in the fuse box 70. Even if the cover 72 is attached to the base 71, the entire 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 with the vehicle frame F. Absent.

In light of FIG. 4, the battery BT is first connected to the electric motor M via the electric wiring E1, the bracket 75, the fuse F1, the contactor relay CT2, the bracket 76, the electric wiring E2, and the contactor relay CT1. The battery BT is also connected to the control computer 60 via the bracket 75, the fuse F1, the electrical wiring E3, the fuse F2 and the electrical wiring E4. The contactor relay CT2 is connected to the control computer 60 and the ground via the electric wires E5 and E6, and the contactor relay CT1 is connected to the control computer 60 and the ground via the electric 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 the power supply from the battery BT.

A major feature of this embodiment is that the fuse box 70 is provided with at least one (two in this embodiment) legs 85. A total of two legs 85 are provided on both sides of the base 71 of the fuse box 70 in the longitudinal direction, and are provided so as to project downward from the bottom surface (lower surface) of the base 71. In this embodiment, the leg portion 85 formed in the shape of a sleeper is illustrated, but the shape can be changed in design. The leg portion 85 may have a separate member attached to the base 71, but in the present embodiment, it is assumed to be a part of the base 71. That is, the base 71 including the legs 85 is integrally molded with resin. The leg 85 is provided with through holes 86 through which bolts for fixing to the vehicle frame F (not shown) are passed vertically, and the fuse box 70 is provided through the legs 85 by the bolts passed through the through holes 86. It is fixed to the upper surface of the vehicle frame F of the vehicle. By forming the base 71 into a raised floor structure in this way, a gap G secured by the legs 85 is interposed between the fuse box 70 and the vehicle frame F. The bolts 73 and 74 are provided in the upper region of the gap G (between the two legs 85) on the base 71, and the gap G is between the upper surface of the vehicle frame F and the heads of the bolts 73 and 74. Intervene. In other words, the base 71 is configured so that the horizontal positions of the bolts 73 and 74 and the legs 85 do not overlap (so that the bolts 74 and 75 and the legs 85 do not overlap when viewed from above and below). The presence of the gap G does not comprehensively mean that the main body of the fuse box 70 and the vehicle frame F are physically separated from each other, but the atmosphere between the main body of the fuse box 70 and the vehicle frame F. It means that a space in which no other substance exists intervenes. That is, the fuse box 70 is grounded to the vehicle frame F only by the legs 85, and the parts other than the legs 85 of the fuse box 70 are in a non-contact relationship with the vehicle frame F and are directly or indirectly through some structure. It is also configured so that it does not come into contact with the vehicle frame F.

In the present embodiment, since the mold resin 81 that restrains the heads of the bolts 73 and 74 exists inside the fuse box 70, the gap G is naturally interposed between the upper surface of the vehicle frame F and the mold resin 81. However, for example, the base 71 may be formed into a shape having holes for passing the bolts 73 and 74, and the bolts 73 and 74 may be inserted and fixed to the base 71 from below. In this case as well, it is necessary to surround the heads of the bolts 73 and 74 with the mold resin 81 for insulation, but the heads of the bolts 73 and 74 and the mold resin 81 are located on the lower side of the base 71. Even if the heads of the bolts 73 and 74 and the mold resin 81 are located below the base 71 in this way, the gap G is interposed between the upper surface of the vehicle frame F and the mold resin 81 by the legs 85. Configure to do.

-Operation-
In FIG. 3, the switching valves V1-V5 are all normally closed type switching valves, and are closed in the degaussed state. With this state as a reference, 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 the power supply from the battery BT. When the solenoid S3 is excited by an electric signal from the control computer 60 when the hydraulic pump P1 is driven, the switching valve V3 is opened and pressure oil is supplied from the hydraulic pump P1 to the rod port and the bottom port of the slide cylinder 33. As a result, the slide cylinder 33 extends due to the difference in the pressure receiving area, and the load receiving table 20 moves backward (for example, is pulled out from the lower part of the vehicle frame F).

When the solenoid S4 is excited 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 from the hydraulic pump P1 to the rod port of the slide cylinder 33. As a result, the slide cylinder 33 contracts, and the load receiving table 20 advances (for example, it is pulled into the lower part of the vehicle frame F).

When the solenoid S2 is excited 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 lowers.

When the solenoid S1 is excited 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 from the hydraulic pump P1 to the bottom port of the lift cylinder 44. As a result, the lift cylinder 44 extends and the load receiving table 20 rises.

-Effect-
In the present embodiment, as described above, the fuse box 70 is provided with the legs 85 so that the gap G is interposed between the bolts 73 and 74 and the mold resin 81 and the vehicle frame F. 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 travels on 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 strongly when the terminals are fixed to the bolts 73 and 74 and the mold resin 81 and the base 71 are cracked, it is possible to prevent water on the vehicle frame F from entering the cracks. Therefore, it is possible to suppress the occurrence of a short circuit when the fuse box 70 is cracked.

-Modification example-
In the above embodiment, the configuration in which the heads of the bolts 73 and 74 are covered with the mold resin 81 has been described as an example, but it is not always necessary to cover the bolts 73 and 74 with the mold resin. For example, even if 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 between the heads of the bolts 73 and 74 and the vehicle frame F. It suffices if the gap G is secured by the above. With such a configuration, it is possible to suppress the occurrence of a short circuit due to the bolts 73 and 74 coming into contact with the water on the surface of the vehicle frame F. Further, resin is poured with the bolts 73 and 74 set in the mold of the base 71 of the fuse box 70, and the heads of the bolts 73 and 74 are embedded in the base 71 at the time of molding the base 71, and the base 71 and the bolt 73, The 74 may be integrally configured. In this case as well, it is not necessary to cover the heads of the bolts 73 and 74 with the molding resin after the molding of the base 71.

Further, in the above embodiment, the structure in which the front end side consignment stand 22 is used as one piece and the consignment table 20 is folded at one place is illustrated. However, by configuring the front end side consignment table 22 with a plurality of front and rear consignment tables, the consignment table The structure may be such that 20 can be broken at two or more places. The fuse box 70 having the above configuration can also be applied to a loading platform elevating device that employs such a loading platform. Further, if the load receiving table can be stored in the lower part of the vehicle frame F simply by pulling it in by the slide cylinder 33 without folding the load receiving table 20, the folding mechanism itself of the load receiving table 20 can be omitted. The fuse box 70 can also be applied to a loading platform elevating device that employs such a loading platform.

In addition, the present invention can be applied to other types of loading platform lifting devices, for example, as long as the loading platform lifting device supports the cargo handling work by raising and lowering the loading platform between the ground and the loading platform. For example, the present invention can also be applied to a loading platform elevating device (for example, JP-A-2010-155600, JP-A-2005-289150) in which a loading platform is stored inside a packing box. The present invention is also applicable to a rotary retractable cradle elevating device (see Japanese Patent Application Laid-Open No. 2010-52569) that rotates the cradle upward without sliding it and stores it in the lower part of the vehicle frame. Further, it can be applied to various loading platform elevating devices (for example, JP-A-2008-189189, JP-A-2007-331631, JP-A-2004-224802) in which the loading platform is raised and stored at the rear of the loading platform. Is.

1 ... Loading platform lifting device, 20 ... Loading platform, 70 ... Fuse box, 73, 74 ... Bolt, 81 ... Mold resin, 85 ... Legs, F ... Car frame, G ... Gap, L ... Loading platform

Claims (3)

In the loading platform lifting device that raises and lowers the loading platform between the height of the floor of the loading platform of the vehicle and the height of the ground.
Equipped with a fuse box that has a bolt inside to fix the terminal
The fuse box is provided with a leg protruding downward, and the fuse box is fixed to the vehicle frame of the vehicle via the leg.
A load receiving platform elevating device in which a gap secured by the legs is interposed between the upper surface of the vehicle frame and the head of the bolt. The load receiving platform lifting device according to claim 1, wherein the head of the bolt is covered with a mold resin, and the gap is interposed between the upper surface of the vehicle frame and the mold resin. The load receiving platform lifting device according to claim 1, wherein the head of the bolt is embedded in the fuse box, and the fuse box and the bolt are integrally configured.

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