JPH08183457A - Heavy load transporting hand truck - Google Patents

Abstract

PURPOSE: To provide a heavy load transporting hand truck that can change a direction and shift sideways, simply, easily and safely in a narrow passage. CONSTITUTION: Rear wheels 2 formed of swivel wheels provided at the rear part of a pan 1, a front wheel 3 supported rotatably around a front lateral axis, and a front swivel wheel 4 are respectively supported so as to be elevated. Jacks 5-7 are provided to separately elevate the rear wheels 2, the front wheel 3 and the front swivel wheel 4, and the respective jacks 5-7 are switched by a direction switching valve 9 into a first levitation state of levitating the pan 1 from the floor face by lowering the rear wheels 2 and the front wheel 3, a second levitation state of levitating the pan 1 from the floor face by lowering the rear wheels 2 and the front swivel wheel 4, and a grounding state of grounding the pan 1 onto the floor face by lifting all the wheels.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for easily and easily loading and turning a heavy object in a narrow passage such as a metaclaas gas circuit breaker (hereinafter referred to as "GCB") of a power plant.
Moreover, the present invention relates to a hand truck for carrying heavy objects that can be safely performed.

[0002]

2. Description of the Related Art As shown in FIG.
A meta-clad disk 102 for accommodating a GCB 101 for opening and closing a high voltage circuit is arranged on one side or both sides of a passage 103. GCB101 has a weight of, for example, about 250 kg,
It is taken out of the meta-clad panel 102 for periodical inspection once a year and for inspection or repair when a failure occurs.
Transported to the work area through the
2

Conventionally, a special cart 200 as shown in FIG. 14, for example, has been used to put the GCB 101 into and out of the metal tray 102. The cart 200 is a GCB.
A tray 201 on which the tray 101 is placed, and the tray 201 are supported so as to be able to move up and down.
A frame 204 for supporting a free wheel 203 on both left and right sides of a rear portion of the motor 201 and an electric winch 205 for driving the pan 201 up and down are provided.

As shown in FIG. 15, wheels 104 are provided at the lower four corners of the front, back, left and right of the GCB 101 so as to be rotatable around the left and right axes, and when the GCB 101 is taken out from the metaclad disc 102, the door of the metaclad disc 102 is opened. After opening, the above trolley
200 in front of the metal platen 102, and then the pan 20
After grounding 1, the GCB 101 is pulled out from the metal tray 102 and placed on the tray 201. And after this,
The bogie 200 is turned by 90 ° in the passage 103 and then moved to a work place for inspection and repair.

[0005] In addition, the GCB
To insert 101, push the trolley 200 with GCB 101 through the passage 103 to the front of the meta-clad disc 102 with the door open, turn the trolley 200 90 ° there, and then open the opening of the meta-clad disc 102. The positions in the width direction of the carriage 200 are moved forward and backward to be aligned, and then the saucer 201 is grounded, and then the GCB 101 is pushed into the meta-clad board 102, whereby the terminal block in the meta-clad board 102 receives the GCB10.
Terminal 1 is inserted.

[0006]

SUMMARY OF THE INVENTION The above conventional hand cart
The 200 uses a system in which the saucer 201 is lifted by an electric winch 205, so it becomes considerably large when including the auxiliary equipment. For example, the hand cart 200 that has been put into practical use has a width of 900 mm, a depth of 1500 mm, and a height of 2000 mm, and weighs approximately
There is 180 kg.

[0007] For this reason, turning the hand cart 200 in the 90 ° direction requires a passage width of about 2000 mm or more.
In the case of a narrow passage 103 of about 00 mm,
Is unusable, and the plywood is
Spread it on 103 and slide it on the plywood with 4 people.
1 is turned 90 °. Therefore, four workers 10
If the 5 do not pay attention to each other, the GCB 101 moves in an unexpected direction, and the worker is forced to move the GCB 101, the passage wall, and the meta-clad board.
Put fingers and toes between the door of 102 and the opening edge,
There is a possibility that the CB 101 collides with the surrounding metal cladding board 102, the doors of the metal cladding board 102, the opening edge, and the like to break or deform them.

In addition, when correcting the traveling direction or sliding the plywood, the floor surface is often damaged or excessive force is applied to the wheels. Further, since the direction of the rotation axis of the GCB wheel 104 is fixed around the left and right axes, in order to move the GCB 101 opposed to the meta-cutter 102 in the left and right direction,
It is necessary to adjust the traveling direction of the GCB 101 while reciprocating the GCB 101 back and forth.

For this reason, the GCB 101 is opposed to the meta-clad disc 102, after rough positioning and stopping, the GCB 101 is moved to the position of the guide rail 108 provided inside the meta-clad disc 102 by moving the GCB 101 on the plywood plate. The wheels 104 of the above are aligned, but this width adjustment takes time. In addition, as shown in FIG. 15, the height of the bottom plate 106 of the metal cladding board receiving the wheels 104 of the GCB 101 in the metal cladding board 102 is different from the height of the floor 107, so that the GCB 10
When putting 1 into the meta club 102
It is necessary to press B101, stuff your limbs,
There is a possibility that the GCB 101 or the metal cladding board 102 may be damaged when the B101 hits the board, or the wheels 104 of the GCB 101 may be damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a weight that allows one worker to easily, easily, and safely change the direction of a heavy object in a narrow passage. It is an object of the present invention to provide a cart for carrying goods.

[0011]

In order to achieve the above-mentioned object, a hand truck for carrying heavy objects according to the present invention is provided with a tray on which heavy objects are loaded and unloaded, and an individual tray supported at the rear of the tray so as to be able to move up and down. One or a plurality of pairs of rear wheels composed of existing wheels, one pair or a plurality of pairs of front wheels rotatably supported on the front part of the saucer, and rotatably around the left and right axis, on the front part of the saucer One or a plurality of pairs of front and rear wheels each of which is supported so as to be able to move up and down, jacks for individually raising and lowering the rear wheel, the front wheel and the front and rear wheels, and the rear wheel and the front wheel for lowering the saucer. A first levitation state in which the pedestal is levitated from the floor surface, a second levitation state in which the rear wheel and the front free wheel are lowered to levitate the saucer from the floor surface, and a grounding state in which all the wheels are raised to ground the saucer on the floor surface. And a control device for controlling each jack. Is shall.

[0012]

When the control device is operated to switch the respective jacks to the first floating state, the front wheel having a fixed rotation axis direction and the rear wheel capable of freely changing the rotation axis direction are placed on the floor surface. Since it is transferred to the car, it becomes possible to turn on the spot centering on the front part of the saucer, and it is easy for one worker to steer the trolley in the narrow passage and correct the direction when moving. It can be done easily and safely.

When the jacks are switched to the second floating state by operating the control device, the front free wheel and the rear wheel, which can freely change the direction of the rotation axis, are rolled on the floor. In addition to being able to turn on the spot around the center of the saucer, when applying a force to move the hand cart in the width direction, the front free wheel and the rear wheel follow the force and change the direction, It rotates around the longitudinal axis.

Further, in the ground contact state, since the tray is grounded, there is no danger of the carriage moving, and since the height of the tray and the floor surface are substantially the same, heavy goods can be safely unloaded. . Rubber (2 mm) is attached to the lower part of the tray to prevent slippage from the floor.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a push cart for carrying heavy objects according to one embodiment of the present invention. An outline of a hand truck for carrying heavy objects according to an embodiment of the present invention will be described. The hand cart includes a tray 1 having bottom plate 1a and side walls 1b, 1c, and 1d rising from three left, right, and rear side edges thereof, and left and right side walls 1c and 1d of the tray 1.
At the rear part, two pairs of rear wheels 2 each of which is a free wheel are supported so as to be able to move up and down at appropriate intervals in the front and rear.

A pair of front wheels 3 is supported on the front portions of the left and right side walls 1c and 1d so as to be able to move up and down and to be rotatable around the left and right axes. A pair of front free wheels 4 is supported by 1c and 1d so as to be able to move up and down. The rear wheel 2, the front wheel 3 and the front free wheel 4 are respectively jacked by 5-7 so that the lower peripheral portion of the wheel advances below the lower surface of the saucer 1 and the lower peripheral portion of the wheel is the lower surface of the saucer 1. It moves up and down over the upper limit position where it retreats upward.

As each of the jacks 5 to 7, it is preferable to use a small-sized jack which uses a pressure oil as a drive source and can obtain a large output. As a jack using pressure oil as a drive source, there is a jack that drives a screw shaft with a hydraulic motor. Here, a hydraulic jack composed of a hydraulic cylinder that is small and that can obtain high output is used. When the jacks 5 to 7 composed of hydraulic jacks are used, a hydraulic pump for supplying pressure oil to each of the jacks 5 to 7 and a hydraulic oil tank for storing hydraulic oil discharged from each of the jacks 5 to 7 are provided. A directional switching valve for controlling the supply and discharge of the pressure oil to and from the jacks 5 to 7 is required.

It is not essential for the present invention to mount these on a hand truck, but in this embodiment, a left side wall 1b has a manual hydraulic pump 8 having a built-in hydraulic oil tank,
A direction switching valve 9 for controlling the supply of pressure oil discharged from the manual hydraulic pump 8 to each of the jacks 5 to 7 and the discharge of hydraulic oil from each of the jacks 5 to 7 to the hydraulic oil tank is supported. .

As shown in FIG. 11, the direction switching valve 9
The position is selectively switched to a first floating position, a second floating position, and a ground contact position. In the first floating position, the discharge port 8a of the manual hydraulic pump 8 is connected to the jack 5- (1) of the rear wheel 2- (1). And the jack 6 of the front wheel 3. In the second floating position, the discharge port 8a of the manual hydraulic pump 8 is connected to the jack 5- (2) of the rear wheel 2- (2) and the jack 7 of the front free wheel 4.

Further, in the grounding position, all jacks 5
To 7 are connected to the discharge port 8a of the manual hydraulic pump 8, and the hydraulic oil tank 8b is operated by the hydraulic relief valve 8c of the manual hydraulic pump 8.
Be communicated to. When the direction switching valve 9 is switched to the first floating position and the discharge pressure of the manual hydraulic pump 8 is increased to a certain value or more by operating the manual hydraulic pump 8, the pressure oil discharged from the manual hydraulic pump 8 is changed to the rear wheel 2- (1). Is supplied to the jack 5- (1) and the jack 6 of the front wheel 3, so that the rear wheel 2 and the front wheel 3 are pushed down to the lower limit position below the lower surface of the tray 1, and the tray 1 rises from the floor surface. The hand cart can move.

When the direction switching valve 9 is switched to the second floating position and the discharge pressure of the manual hydraulic pump 8 is increased to a certain level or more by operating the manual hydraulic pump 8, the pressure oil discharged from the manual hydraulic pump 8 causes the rear wheel 2 The rear wheel 2 and the front free wheel 4 are pushed down to the lower limit position below the lower surface of the receiving pan 1 because the jack 5 is supplied to the jack 5- (2) and the jack 7 of the front free wheel 4.
The pan 1 rises from the floor surface, and the cart can move.

After switching the direction switching valve 9 to the grounding position at an arbitrary time, the hydraulic relief valve 8 attached to the manual hydraulic pump 8
When c is opened, all jacks 5 to 7 are communicated with the hydraulic oil tank 8b in the manual hydraulic pump 8, the front free wheel 4 and the rear wheel 2 are springs shown in FIG. 8, and the front wheels 3 are springs shown in FIG. The hydraulic oil in all the jacks 5 to 7 is returned to the hydraulic oil tank 8b in the manual pump 8, and the pan 1 touches the floor surface so that the cart cannot move.

The relatively important structure of the hand cart will be described below in more detail with reference to FIGS. 3 to 12. Here, the structure for supporting the front wheel 3 on the tray 1 will be described first. The front wheel 3 can move up and down on the pan 1, and
The bracket 10 is fixed to the left side wall 1c (or the right side wall 1d) of the pan 1 as shown in FIGS. The block 12 is connected to the bracket 10 via an angle-type connecting member 11.

That is, a pair of upper and lower round holes are formed in the block side portion 11a of the connecting member 11, and the bolt 12 inserted into these round holes is screwed into the block 12 and tightened to block the block 12. Are fixed to the connecting member 11. In addition, a plurality (here, 4
), And a plurality (two in this case) of bolts 14 inserted into these vertical holes 11c are screwed into the bracket 10 and the left side wall 1c (or the right side wall 1d). Thereby, the block 12 and the connecting member 11 are fixed to the bracket 10 and the left side wall 1b (or the right side wall 1c).

A vertical adjusting bolt 15 is screwed onto the upper portion of the bracket 10, and the height of the block 12 can be adjusted by the adjusting bolt 15 in a state where the bolt 14 is loosened. By fixing the block 15 to the bracket 10 by the lock nut 16 and tightening the bolt 14 while pressing the block 12 against the adjustment bolt 15, the block 12 can be fixed at the precisely adjusted height.

A vertical axis 17 is inserted into one side of the block 12 so as to be able to move up and down. A pair of upper and lower oilless bearings 18 for guiding the vertical axis 17 up and down are provided in the block 12. .
A bearing frame 19 is fixed to the lower end of the vertical axis 17, and the front wheel 2 is rotatably fitted on a wheel shaft 20 fixed to the lower part of the bearing frame 19. The jack 6 is incorporated in the other side portion of the block 12, the bearing frame 19 is connected to the piston rod 21 of the jack 6 by the screw 22, and when the pressure oil is supplied to the jack 6, the bearing frame 19, the wheel shaft 20 and the front wheel 2 is pushed down to the lower limit position shown by the chain double-dashed line.

A spring seat 23 is fixed to the upper end of the vertical axis 17. A spring 24 inserted between the spring seat 23 and the block 12 causes the vertical axis 17, the bearing frame 19, the wheel axle 20 and the front wheel 2. Is biased to the upper limit position shown by the solid line. Next, a structure for supporting the front free wheel 4 on the tray 1 will be described with reference to FIGS.

It suffices that the front free wheel 4 is supported on the pan 1 so as to be able to move up and down. Here, the bracket 25 is fixed to the left side wall 1c (or the right side wall 1d) of the pan 1, and the bracket 25 has an angle. Block through mold connecting member 26
27 are connected. That is, a pair of upper and lower round holes are formed in the block-side portion 26a of the connecting member 26, and a bolt 28 inserted into these round holes is screwed into the block 27 and tightened to connect the block 27 to the connecting member. Fixed to 26. A plurality (four in this case) of vertically long holes 26c are formed in the bracket side portion 26b of the connecting member 26, and these vertically long holes 26c are formed.
Are screwed into the bracket 25 and the left side wall 1c (or the right side wall 1d) to thereby connect the block 27 and the connecting member 26 to the bracket 25 and the left side wall 1c. (Or right side wall 1d)
Fixed to.

On the upper part of the bracket 25, an adjustment bolt on the vertical axis
30 is screwed and bolt 29 is loosened.
The height of the block 27 can be adjusted by 30. After the adjustment, the adjustment bolt 30 is fixed to the bracket 25 by a lock nut 31, and the block 27 is
By tightening the bolt 29 while pressing the block 27, the block 27 can be fixed at a precisely adjusted height.

A vertical axis 32 is vertically movably inserted through one side of the block 27, and a pair of upper and lower oilless bearings 33 for guiding the vertical axis 32 is provided in the block 27. ,
On the other side of the block 27, a jack 7 is incorporated. One end of an elevating plate 34 is fixed to the lower end of the longitudinal axis 32, and the other end of the elevating plate 34 is fixed to a cylinder rod 35 of the jack 7 by screws 36.
The front free wheel 4 is fixed to the lower surface of the other end of the.

As a result, when pressure oil is supplied to the jack 7, the vertical axis 32, the lifting frame 34, and the wheel 4g of the front adjustable wheel 4 are pushed down to the lower limit position indicated by the two-dot chain line. A spring seat 37 is fixed to the upper end of the vertical axis 32, and is inserted between the spring seat 37 and the block 27 when the jack 7 is connected to the hydraulic oil tank of the manual hydraulic pump 8. The spring 38 urges the vertical axis 32, the lifting frame 34, and the front adjustable wheel 4 to the upper limit position shown by the solid line.

The front free wheel 4 has a board 4a fixed to the lifting plate 34, a turning center shaft 4b vertically suspended from the board 4a, and a lower end of the turning center shaft 4b. A bearing frame 4c freely fitted to the outside, a nut 4d screwed from below the bearing frame 4c to a lower end of the turning center shaft 4b to prevent the bearing frame 4c from falling off, a base 4a and the bearing frame 4c.
And a thrust ball type bearing 4e coaxially interposed with the turning center shaft 4b, and a horizontal wheel shaft 4 inserted at a position eccentric from the turning center shaft 4b below the bearing frame 4c.
f and a wheel 4g rotatably fitted on the wheel axle 4f, the wheel can be freely horizontally swiveled around the turning center axis 4b regardless of its height, and the wheel axle is horizontal regardless of the turning direction. It can rotate freely around 4f.

The structure for supporting the rear wheel 2 composed of a universal wheel on the saucer 1 is exactly the same as the structure for supporting the front universal wheel 4 on the saucer. I will omit it. As shown in FIGS. 1 to 4, a positioning plate 39 is provided at the front of the tray 1 so as to protrude forward from the front edge of the left side wall. And a guide rail provided therein, and by moving the push cart toward the opening edge side, the position of the push cart with respect to the meta-kura board can be accurately determined.

According to this hand cart, since it is not necessary to provide a high mast on the frame for hoisting the tray 1, the height can be lowered to, for example, about 600 mm, and the space occupied by the auxiliary equipment can be reduced, and the width and depth can be reduced. For example, the size could be reduced to about 800 mm x 1000 mm, and the weight could be reduced to about 800 kg with the miniaturization.

Next, the operation of taking out the GCB from the meta-clad board using this hand cart will be described. After switching the direction switching valve 9 of the empty push cart to the first floating position and operating the manual hydraulic pump 8 to obtain a predetermined discharge pressure, push the push cart to enter the passage in front of the meta-cradle. . The first floating state, which has higher operation stability than the second floating state, is preferable up to the vicinity of the meta-crawler in order to prevent the hand cart from swinging.

When we arrive in front of the meta-clad board, open the door of the meta-clad board, and then turn the hand cart by 90 ° in front of the meta-clad board, when the passage width is about 1700 mm, the hand cart is downsized. Even in the first floating state, the hand cart can be turned 90 ° in front of the meta-clad board. When the width of the passage is less than 1700 mm, the direction switching valve 9 is switched to the second floating position, and in the second floating state, the turning direction can be changed freely. When the rear wheel 2 is made to contact the floor surface, for example, 13
If there is a passage width of 00 mm or more, it is possible to turn 90 ° on the spot around the center of the tray 1.

Further, the front portion of the hand truck is a front free wheel 4
In the second floating position supported by, the front free wheel and the rear wheel whose direction of the rotation axis can be freely changed are brought into rolling contact with the floor surface, so that the center of the saucer is centered on the spot. In addition to being able to turn, when a force is applied to move the handcart in the width direction, the front and rear wheels change directions following the force and rotate around the front-rear axis. In addition, the hand truck can be moved in the width direction easily and safely, and it is easy, easy, and safe for one worker without giving excessive force to the wheels or damaging the floor. The front part of the hand cart can be slightly moved in the left and right directions.

At this time, the positioning plate 39 is inserted between the opening edge of the meta-clad board and a guide rail provided inside the meta-clad board, and the hand-pushed carriage is moved to the opening edge side to accurately position the hand-pushed carriage with respect to the meta-clad board. Indexed to
Further, as shown by a chain double-dashed line in FIG. 12, the hand cart is pushed into the opening of the meta-clad disc until just before the bottom plate 1a comes into contact with the front edge of the meta-clad disc bottom plate 40, and the direction switching valve 9 is switched to the grounding position to switch the manual hydraulic pressure. Hydraulic relief valve 8c attached to pump 8
, All jacks 5 to 7 are manually operated by hydraulic pump 8
Hydraulic oil tanks, and springs 24 and 38, respectively.
The rear wheel 2, front wheel 3 and front free wheel 4 are all raised to the upper limit position by the urging force, and the tray 1 is grounded. This time,
The saucer 1 on the pillow plate 41 that supports the meta-clad disc bottom plate 40 on the floor 42
Is received, and the height of the upper surface of the bottom plate 40 of the metal cladding board and the height of the upper surface of the bottom plate 1a of the tray 1 become the same.

After that, the GCB 101 is pulled out from the meta-clad disc 102 and placed on the bottom plate 1a of the hand truck. During this period, the saucer 1 of the hand truck is grounded, so the GCB 101 is grounded.
There is no danger that the GCB 101 will be pushed out of the way to the side of the aisle, and the GCB 101 can be safely replaced from the meta-kura board 102 to the hand cart. Further, after this, after attaching the stopper 43 for preventing falling off to the tray 1, the hand cart is pulled out into the passage in the first floating state, switched to the second floating state, turned 90 °, and then returned to the first floating state. Switch and move to the workplace.

When the GCB 101 is carried from the work place to the meta-cutter 102, the direction switching valve 9 of the hand truck carrying the GCB 101 is switched to the first floating position, and the manual hydraulic pump 8 is operated to obtain a predetermined discharge pressure. After that, push the hand cart and enter the passage 103 in front of the meta club. The first floating state, which has a higher steering stability than the second floating state, is preferable to the vicinity of the meta-crawler 102 in order to prevent the hand cart from swinging.

Arriving in front of the meta-kura board 102,
After the door 2 is opened, the directional control valve 9 of the hand cart is switched to the second floating position in front of the meta-kura board 102, the second floating state is set, and the front universal wheel 4 which can freely change the rolling direction and the rolling direction are changed. Since the rear wheel 2 which can be freely changed is rolled on the floor surface, if there is a passage width of 1300 mm or more, a 90 ° turn can be made on the spot around the center of the tray 1.

Further, the front part of the hand cart is a front free wheel 4
It is supported by, so that one worker can easily, comfortably and safely finely move the hand cart in the left and right direction without giving excessive force to the wheels or damaging the floor, The position in the width direction of the hand cart can be adjusted with high accuracy. At this time, the positioning plate 39 is inserted between the opening edge of the meta-clad board and the guide rail provided inside the meta-clad board, and the hand-pushed carriage is moved to the opening edge side to accurately determine the position of the hand-pushed carriage with respect to the meta-clad board 102. As shown in FIG. 12, until the bottom plate 1a comes into contact with the front edge of the meta-clad bottom plate 40, the meta-clad disc 10
Push the hand cart into the opening of 2, switch the direction switching valve 9 to the grounding position, and open the hydraulic relief valve 8c attached to the manual hydraulic pump 8.

Thus, all the jacks 5 to 7 are communicated with the hydraulic oil tank 8b of the manual hydraulic pump 8, and the rear wheels 2, the front wheels 3 and the front free wheels 4 are all moved to the upper limit position by the urging forces of the springs 24 and 38, respectively. And the saucer 1 is grounded. The front edge of the tray 1 is received by the pillow plate 41 that supports the bottom plate 40 of the metal tray, and the upper surface of the bottom plate 40 of the metal tray and the upper surface of the bottom plate 1a of the tray 1 are at the same height.

After that, when the GCB 101 is pushed from the push cart into the meta-cutter 102, the position of the push cart in the width direction is finely adjusted in advance. The GCB 101 can be pushed from the cart to the meta-cutter 102 in a timely and safe manner. While the GCB 101 is pushed from the push cart into the metal tray 102, there is no danger that the push cart will recoil and jump out to the passage side because the tray 1 is grounded.
CB101 can be replaced.

Also, in this embodiment, since the front edge of the bottom plate 1a of the cart is grounded at the same height as the front edge of the bottom plate 40, the GCB 101 is attached to the metal plate 102 from the cart. It is not necessary to give momentum to the GCB 101 when it is pushed in, so that the work becomes easier and the work safety can be improved. In the above embodiment, the manual hydraulic pump 8 is mounted on the tray 1, but the jacks 5-5
A hydraulic oil tank 8b for storing the hydraulic oil discharged from 7,
It is not essential to the present invention to mount the manual hydraulic pump 8 that pressurizes the hydraulic oil stored in the hydraulic oil tank 8b to discharge the pressure oil and the direction switching valve 9 on a hand truck.

However, the direction switching valve 9 is preferably carried out by an operator pushing the hand cart to improve the operability thereof. Therefore, the direction switching valve 9 is preferably provided on the hand cart as described above. In the present invention, when the manual hydraulic pump 8 and the hydraulic oil tank 8b are not mounted on the hand cart, each jack or direction switching valve 9 mounted on the bogie is connected to the manual hydraulic pump 8 and the hydraulic oil tank 8b. More than one hydraulic hose is required, and a hose reel for winding up the excess length of these hydraulic hoses is provided as necessary.

Therefore, it is preferable to mount the manual hydraulic pump 8 and the hydraulic oil tank 8b on a hand cart in order to simplify the configuration, reduce the size, reduce the weight, liberate the moving range, and improve the workability. It is particularly preferable to use a manual hydraulic pump 8 having a built-in oil tank 8b. Further, in the present invention, when the hydraulic pump is not mounted on the hand truck, an electric hydraulic pump or a prime mover hydraulic pump can be used as the hydraulic pump, but the simplification of the configuration, the miniaturization, and the weight saving are improved. In order to achieve the above, it is preferable to use the manual hydraulic pump 8.

In the present invention, it is not essential to provide two pairs of rear wheels 2, but one pair of rear wheels 2 may be provided. It is also possible to provide one rear wheel 2 at the center of the back of the tray 1 in the left-right direction so as to be able to move up and down.
It is preferable to provide a pair of right and left for improving the stability of the hand cart, and particularly preferable for increasing the stability at the time of turning.

[0049]

As described above, the hand truck for transporting heavy objects according to the present invention comprises a tray for loading and unloading heavy objects, and each free wheel supported at the rear of the tray so as to be able to move up and down.
A pair or a plurality of pairs of rear wheels, one or a plurality of pairs of front wheels supported so as to be able to ascend and descend at a front portion of the pan, and rotatably around the left and right axes, and are supported to be able to ascend and descend at a front portion of the pan. One or more pairs of front free wheels, each jack for individually raising and lowering the rear wheel, the front wheel, and the front free wheel, and lowering the rear wheel and the front wheel to lift the tray from the floor. Each jack is set in a first floating state, a second floating state in which the rear wheel and the front free wheel are lowered to lift the pan from the floor, and a ground state in which all wheels are raised to ground the pan on the floor. A control device for controlling is provided.

Therefore, in the first floating state, the front wheel whose rotation axis is fixed to the left and right and the rear wheel whose rotation axis is freely changed are rolled on the floor surface. This makes it possible to turn around the part on the spot, and a single worker can easily, easily and safely turn the bogie in a narrow passage. Further, in the second floating state,
The front and rear wheels, which can freely change the direction of the axis of rotation, are rolled on the floor, so that they can turn on the spot around the center of the pan, allowing one worker to further rotate. It is easy and easy to change the direction of the bogie in a narrow passage,
It can be done safely, and if a force in the width direction is applied to the front part of the cart, the rotation axis of the front freewheel will follow the force and move in the front-rear direction. In this way, it is possible to easily, comfortably and safely perform the alignment in the width direction by one worker without damaging the floor.

In addition, in the state of contact with the ground, since the tray is grounded, there is no danger that the truck will move, and it is possible to load and unload heavy objects safely. In the present invention, in particular, each of the jacks is constituted by a hydraulic jack, a hydraulic oil tank, a hydraulic pump that pressurizes hydraulic oil stored in the hydraulic oil tank to discharge pressure oil, a rear wheel jack and a front wheel jack. Are connected to the discharge port of the hydraulic pump, a second floating state is in which the jack of the rear wheel and the jack of the front free wheel are connected to the discharge port of the hydraulic pump, and all jacks are in the hydraulic oil tank. In the case where the trolley is provided with a direction switching valve that can be switched to a ground state that is communicated with the trolley, the hand cart can be made smaller as a whole, and the three states of the first floating state, the second floating state, and the ground state can be controlled by one direction. Switching by a valve simplifies wheel lifting control operations.

Further, in this case, a hydraulic oil tank having a built-in hydraulic oil tank, which is manually operated, is provided with the hydraulic pump mounted on the pan and the directional switching valve mounted on the pan. , The movement range of the hand cart can be unlimited. In addition, by using the manual pump in this manner, the hand truck can be further reduced in size, and a special drive power source is not required, and energy can be saved.

[Brief description of drawings]

FIG. 1 is a side view showing the configuration of an embodiment of the present invention.

FIG. 2 is a plan view showing the configuration of an embodiment of the present invention.

FIG. 3 is a side view of one embodiment of the present invention.

FIG. 4 is a plan view of an embodiment of the present invention.

FIG. 5 is a side view of a front wheel support structure according to an embodiment of the present invention.

FIG. 6 is a front view of a front wheel support structure according to one embodiment of the present invention.

FIG. 7 is a plan view of a front wheel support structure according to one embodiment of the present invention.

FIG. 8 is a front view of a front adjustable wheel support structure according to an embodiment of the present invention.

FIG. 9 is a side view of a front adjustable wheel support structure according to an embodiment of the present invention.

FIG. 10 is a plan view of a front adjustable wheel support structure according to an embodiment of the present invention.

FIG. 11 is a hydraulic circuit diagram of one embodiment of the present invention.

FIG. 12 is a side view of a main part in a grounded state of one embodiment of the present invention.

FIG. 13 is an explanatory diagram of a conventional work of taking GCB in and out of a meta-cracking machine.

FIG. 14 is a schematic side view of a conventional example.

FIG. 15 is an explanatory diagram of a work of loading / unloading a GCB to / from a conventional meta-clad disk.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Receiving tray 2 ... Rear wheel 3 ... Front wheel 4 ... Front free wheel 5-7 ... Jack 8 ... Manual hydraulic pump 9 ... Direction switching valve

Claims (3)

[Claims] 1. A receiving tray on which a heavy object is unloaded, one or more pairs of rear wheels, each of which is supported by a rear part of the receiving tray so as to be able to move up and down, a vertically movable part at a front part of the receiving tray, and One or more pairs of front wheels rotatably supported around the left and right axes, one or more pairs of front free wheels each of which is supported on a front portion of the tray so as to be able to move up and down, and the rear wheels A jack for individually raising and lowering the front wheel and the front free wheel, a first floating state in which the rear wheel and the front wheel are lowered and the pan is raised from the floor, and the pan is lowered by lowering the rear wheel and the front free wheel. A hand truck for transporting heavy goods, comprising: a control device for controlling each jack in a second floating state in which the floor rises from the floor and in a grounding state in which all wheels are lifted and the pan is grounded on the floor. 2. Each of the jacks comprises a hydraulic jack, a hydraulic oil tank, a hydraulic pump for discharging hydraulic oil by pressurizing hydraulic oil stored in the hydraulic oil tank, a rear wheel jack and a front wheel jack. A first floating state in which the jacks of the rear wheels and the front free wheels are connected to the discharge ports of the hydraulic pump, and a second floating state in which all jacks are connected to the hydraulic oil tank. The hand truck for transporting heavy goods according to claim 1, further comprising a direction switching valve that is switched to a ground state that is communicated with the vehicle. 3. A hydraulic pump having a built-in hydraulic oil tank and manually operated, the hydraulic pump mounted on a pan, and the direction switching valve mounted on the pan. Item 3. A hand truck for carrying heavy goods according to item 2.