JPH1159906A - Truck tiering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stack an empty truck in tiers automatically and efficiently without positional deviation. SOLUTION: The truck tiering device which stacks predetermined number of trucks B in tiers comprises a portal lifting frame 3 provided to be elevatable to a machine frame 1, a lift drive source 2 which vertically drives the lifting frame 3, at least two pairs of front and rear truck holding pawls 4, 4 which are provided on the opposite side at lower ends of both leg parts 3a of the lifting frame 3 to be movable in the advance/retreat direction and which are capable of lifting and holding of the truck B, and a truck guiding rail 5 which is provided on a bottom of the machine frame 1 and extends from an entrance opening part of the machine frame 1 to a depth part. Accordingly, the lift drive source 2 is driven and following trucks are carried below the lifted truck by the lifting frame 3 and the truck holding pawls 4, 4, 4, 4 to perform a stacking of the trucks in tiers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bogie stacking device for stacking empty bogies for mounting works on a plurality of stages.

[0002]

2. Description of the Related Art For example, in order to further process or assemble a large-sized work such as an automobile engine processed in a factory in another factory, it is often performed to mount these works on a trolley and transport them by truck. ing. In the case of such a transfer of the work, the empty trolley after unloading the work at the transfer destination factory is stacked by a plurality of units by a worker's hand, and then loaded on a truck again to be transferred to the transfer source factory. It is returned to the address and is used repeatedly for work transfer.

[0003]

However, when the workpiece is an automobile engine, usually, the empty bogie is one.
The stand weighs more than 30 kg, occupies a large area, requires two or more personnel for stacking work, requires a large amount of labor, and requires careful work in terms of safety. Needed.

SUMMARY OF THE INVENTION In view of the above problems, the present invention enables automatic and efficient stacking of empty trolleys for mounting workpieces without any positional displacement between the upper and lower parts, and furthermore, a highly safe bogie stacking apparatus. Accordingly, it is an object of the present invention to provide a bogie stacking device that can be suitably used for a bogie on which a large work such as an automobile engine is mounted.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a bogie stacking device for stacking a predetermined number of bogies. An elevating frame, an elevating drive source for driving the elevating frame up and down, and at least two front and rear ends provided at the lower ends of both legs of the elevating frame so as to be able to move back and forth and to lift and hold the cart.
A pair of trolley holding claws, and a bogie guide rail extending from the entrance opening of the machine frame to the back at the bottom of the machine frame, driving the lifting drive source to drive the lifting frame and the carriage holding claw. A bogie stacking device that loads a succeeding bogie below the lifted bogie and stacks the bogies, and the hoisting drive source is for a hoisting frame that is erected downward on the upper surface of a central portion of the machine frame. An air cylinder, comprising: a bogie stacking device in which the lift frame is connected to a piston rod of the lift frame air cylinder.

[0006] Further, the carriage holding claw is always kept horizontal, and cannot be turned downward, and can be turned upward by 90 ° around an installation base by an external force from below. The bogie guide rail is configured such that the bogie guide rail is configured such that an end on the entrance opening side is a wide and a bogie introducing part that is inclined downward and forward, and a rear end is formed. A bogie stacking device that is inclined upward to form a bogie stop, and a rail positioning member is widened outward to provide a bogie positioning space, and a front wheel of the bogie is provided in the bogie positioning space. Is a bogie stacking device so as to stop, and the lifting frame air cylinder is a single-acting air cylinder that rises by the supply of pressure air and descends by its own weight, The air frame for the lifting frame A bogie stacking device provided with an air pressure circuit for performing a lifting / lowering operation of the hoisting frame by a combination of a carry-in bogie detecting means, a predetermined number of bogie bogie stacking means, and a hoisting frame descent limit position detecting means; Occasionally, a bogie stacking device provided with an emergency stop control valve that shuts off the pressurized air and stops all operations in the air pressure circuit, and further at the entrance opening of the machine frame, A trolley stacking device provided with a safety fence which is linked and ascending and descending, and a trolley for stacking trolleys having a plurality of erected stacking engaging portions which are positioned in contact with the lower end of the upper trolley during stacking A stacking device is provided.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A bogie stacking apparatus A according to the present invention is shown in FIG.
As shown in FIG. 1, a machine frame 1 formed in a box shape by a frame material, an air cylinder 2 for an elevating frame erected at the upper center of the machine frame 1, and an air cylinder 2 for the elevating frame, A gate-shaped lifting frame 3 having a bogie holding claw 4 attached to the lower end thereof and capable of moving forward and backward in the opposite direction, and a bogie guide rail 5 laid on the bottom of the machine frame 1 for loading and unloading the bogie.
This is a device for carrying the cart B into the machine frame 1 and stacking it.

The truck B in FIG. 2 that is stacked in the truck stacking device A is a truck on which an engine for an automobile is mounted as a work, and the engine is stably mounted on the upper surface of a substantially planar rectangular frame 41. The axle 43 is formed on a platform 42 in which bar members and the like are combined in accordance with the shape of the engine so as to be mounted. Wheels 44 are rotatably attached to both ends to facilitate movement.

A puller 45 is attached to the rear side (front side in the figure) of the frame 41 for a moving operation by an operator, and a pair of right and left rod-shaped handles 46 are provided upright. Further, when a plurality of carts B are stacked one above the other, the unevenness of the table surface 42 can be used for stable engagement between the carts, and a predetermined length of Dolly B to which an engaging member is attached and stacked
A pair of step stacking engaging portions 47 for receiving the frame 41 without displacement is formed, and the frame 4 of the upper bogie B is formed on the front side.
A step stacking engaging portion 48 for properly holding 1 is provided to prevent a positional shift between the upper and lower bogies. In addition, the base end of the left handle 46 is fixed to the outside of the frame 41 with the tip slightly inclined to the side of the tow 45, and the base end of the right handle 46 is set slightly above the top surface of the frame 41 to the side of the tow 45 slightly. It is fixed to tilt backward. In FIG. 2, reference numeral 49 denotes a built-up portion for facilitating the positioning of the tip of the right handle 46. FIG. 3 is a perspective view of the carts stacked in four stages.

More specifically, referring to FIGS. 4 and 5, the machine frame 1 which forms a box-shaped frame and on which the bogies B are stacked is used for carrying the bogies B in and out. Is formed at the entrance opening 6, and a bogie guide rail 5 is laid at the bottom in the machine frame 1. The truck guide rail 5 has rail members 5A and 5B having an L-shaped cross section arranged opposite to each other, so that the wheels 44 of the truck B are guided between the rail walls, and front and rear of the rail members 5A and 5B. The rail width can be adjusted by adjusting screws 7, 7 provided in a pair.

The bogie guide rail 5 is provided with rail members 5A, 5A at the stop position of the front wheel (front wheel) 44 of the carry-in bogie B.
A portion of 5B is widened outward to provide an alignment space 8, so that the engagement between the upper and lower carriages can be performed correctly.
That is, at the time of stacking the carts B, the positioning between the upper and lower carts is performed at the stacking engaging portion 47 for receiving the cart frame at the rear as described above. The position of the carry-in truck B can be corrected using the front positioning space 8.

Further, the rail members 5A and 5B are used as a bogie stop portion 5a for stopping the carry-in truck by inclining the rear ends upward, and the front portions of the rail materials 5A and 5B are widened forward and the front ends. Is formed in the bogie introduction portion 5b by being inclined downward so as to contact the floor surface. In addition, on the tops of the rail members 5A and 5B, that is, on the rail walls at the positions corresponding to the positions of the wheels 44 of the bogie B on the front side and the rear side, a bogie bouncing confirmation plate 9 is provided by the inclined pieces. The upper and lower bends of the frame 41 of the truck B guided and carried in can be confirmed.

In the center of the upper surface of the machine frame 1, a lifting frame air cylinder 2 for moving the piston rod 12 downward is provided.
(See FIG. 5), and a gate-shaped lifting frame 3 that moves up and down in the machine frame 1 is connected to the lower end of the piston rod 12 of the lifting frame air cylinder 2. The lift frame air cylinder 2 is a single-rod single-acting type, in which pressure air is supplied only at the time of ascending, at the time of descending, the supply air is removed, and the lift frame 3 connected to the piston rod 12 descends by its own weight. It is like that. The reason why the lifting / lowering frame air cylinder 2 is of a single-acting type and is of a self-weight lowering type is that, when a reversing air cylinder is used, the lifting / lowering frame 3 does not stop immediately when the air supply is stopped during an emergency stop. This is to take into account the occurrence.

As shown in FIG. 1, lower members 3b, 3b made of horizontal members in the front-rear direction are attached to lower ends of left and right legs 3a, 3a of the lifting frame 3, respectively.
3b, the front and rear ends thereof are guided by opposing grooves of a lifting frame guide portion 13 erected along both side surfaces of the machine frame 1, and are moved up and down by shortening and extending the piston rod 12 of the air cylinder 2 for lifting. It works.

The lower members 3b are rotatably mounted on the lower members 3b, 3b with two pairs of front and rear claws 4, 4 via pins 4a, 4a, respectively, as shown by arrows in FIG. It moves forward and backward in the opposite direction by vertical rotation about the base. That is, two pairs of the carriage holding claws 4,
The so-called "4" always takes a horizontal position on the opposite side due to its own weight and cannot rotate downward, but can rotate upward within an angle range of 90 ° around the mounting base by an external force from below, while being so-called. It is formed on a knock-back type bogie holder (see FIG. 6). Therefore, when the lifting frame 3 is lowered, the carriage holding claws 4 and 4 come into contact with the frame 41 of the carry-in carriage B placed on the rail members 5A and 5B and rotate upward. Can be received in the lift frame 3, and the received cart B can be raised and lowered by the lift frame 3 in a lifted state.

In this embodiment, the bogie holding claws 4, 4 are rotatably mounted directly on the lower members 3b, 3b. However, they are mounted on the lower members 3b, 3b via small cylinders to face each other. It may be possible to engage or disengage with the frame 41 of the bogie B by linearly moving back and forth in the direction.

At the back of the machine frame 1, that is, at the rear, there is provided a carry-in truck detecting means 14 by a sensor such as a limit switch which detects the frame 41 of the truck B and emits a signal to confirm the carry-in of the truck B to an appropriate position. In the upper part of the lift frame 3, a predetermined number of trucks (here, four trucks) are stacked and detected by a sensor such as a limit switch that detects a frame 41 of an uppermost bogie B of the bogie B and emits a signal. Means 15 are provided to detect the four-stage stacking of the bogies B. In the lower portion of the machine frame 1, the lowering frame 3 is lowered by a sensor such as a limit switch which detects a lower member 3b of the lifting frame 3 and emits a signal. The limit position detecting means 16 is provided to detect the lower limit position of the lift frame 3. These detection means are not limited to limit switches, and non-contact detection means such as a general optical sensor may be used.

Further, as shown in FIG. 5, a safety fence 17 made of wire mesh is provided at the entrance opening 6 of the machine casing 1 so as to be able to move up and down, and this safety fence 17 is attached to the upper frame of the entrance opening 6. Piston rod 1 of air cylinder 18 for fence
When the lifting frame is operated, it is held in a closed state that does not hinder the carrying in of the carry-in truck B, so that the intrusion of an operator or the like into the machine frame 1 is prevented. A safety cover 20 made of wire mesh is provided on the side of the machine frame 1 except for the entrance opening 6.
In order to prevent intrusion of fingers and the like into the operating portion in the machine frame 1.

The linking operation of the bogie stacking device A configured as described above will be described. The first cart B to be stacked is carried into the machine frame 1 according to the cart guide rail 5,
After confirming that the carry-in vehicle detection means 14 has carried in the proper position, the supply air of the lift frame air cylinder 2 is removed, and the lift frame 3 is lowered until the lift frame lowering limit position detecting means 16 detects it. The first truck B can be taken into the lift frame 3 by the knockback type carriage holding claws 4, 4, 4, 4. Next, as shown in FIG. 7A, the first bogie B is held by the bogie holding claws 4, 4, 4, 4 by raising the elevating frame 3.
Can be lifted and held.

In the state where the first carriage B is lifted and held, the second carriage B is carried into the machine frame 1 in accordance with the carriage guide rails 5, and it is confirmed that the second carriage B has been carried into the proper position as in the case of the first carriage B. After that, by lowering the lifting frame 3,
As shown in FIG. 7B, a first truck B and a second truck B
Are stacked. Further, by lowering the lifting frame 3 to its lower limit position, the second bogie B is taken into the lifting frame 3 by the above-described reciprocating operation of the bogie holding claws 4, 4.
By raising the elevating frame 3 again, the first bogie B and the second bogie B can be lifted and held in a stacked state. When the first truck B comes into contact with the second truck B and is stacked, the worker's stacking engagement portions 47 of the truck B,
At 48 and the like, the engagement of the upper and lower carriages is confirmed, and the displacement is corrected using the positioning space 8 of the carriage guide rail 5.

As shown in FIGS. 7 (c) and 7 (d), the same operation is performed for the subsequent bogies B, so that a predetermined number, here four bogies B, can be stacked. it can. After the first bogie B is detected by the bogie predetermined number of bogies detecting means 15, the four bogies are mounted on the bogie guide rails 5 by lowering of the lifting frame 3. The trolley | bogie which completed this stacking is carried out outside from the machine frame 1 by an operator, for example, is lifted by a forklift and loaded on a truck.

The operation of the bogie stacking device A has been described for the case where an operator carries the bogie B into and out of the machine frame 1 for convenience of explanation. Of course, this can be done.

In the bogie stacking device A, after the pressure air from the air pressure source is reduced to a predetermined pressure by the air pressure control valve, the emergency stop button in the operation unit 21 shown in FIGS. The operation of the carry-in trolley detecting means 14, the predetermined number of trolleys, the stacking detecting means 15, and the lifting frame lowering limit position detecting means 16 are performed by the operation of the button 22, the operation button 23, the forced lowering button 24, and the stacking completion button 25. Further, under the control of various control valves and switching valves, the air cylinder 2 for the lifting frame and the air cylinder 18 for the safety fence are driven or stopped.

That is, in the bogie stacking apparatus A, the above-described automatic operation can be performed by utilizing an air pressure circuit, and therefore, will be described with reference to the air pressure circuit diagram of FIG.

The bogie stacking device A includes a main valve 28 which is a manually input type three-way control valve connected to an air pressure passage from an air pressure source 27.
, And an emergency stop control valve 29 for stopping all air pressure operations in the event of an abnormality, a lifting and lowering operation control valve 30 for raising and lowering the lifting frame 3 for lifting the bogie, and a forcible lowering for lowering the lifting frame 3 The vehicle includes a control valve 31 and a stacking completion control valve 32 that lowers the lift frame 3 and raises the safety fence 17 when stacking of the bogie B is completed. The control valve 29 for emergency stop, the control valve 30 for raising / lowering operation, the control valve 31 for forced lowering, and the control valve 32 for completion of stacking are respectively provided with the emergency stop button 22, the operation button 23 and the forced lowering button of the operation panel 21. The input operation is performed by the button 24 and the stacking completion button 25.

Further, a switching valve 33 for emergency stop, a switching valve 34 for lifting and lowering, and a driving air switching valve 35 are provided between the main valve 28 and the air cylinder 2 for lifting frame by a five-way control valve. The switching valve 33 for emergency stop is turned on and off by the control valve 30 for raising and lowering operation and the control valve 29 for emergency stop, and the switching valve 34 for raising and lowering is controlled by the control valve 30 for raising and lowering operation.
The emergency air control valve 29 and the forced lowering control valve 31 are operated to raise and lower, and the drive air switching valve 35 is turned on and off by the raising and lowering operation control valve 30 and the stacking completion control valve 32. It has become.

Further, reference numeral 36 denotes a falling end detection control valve,
Reference numeral 7 denotes a bogie detection control valve, and reference numeral 38 denotes a bogie detection control valve. The lifting frame lowering limit position detecting means 16, the bogie predetermined number of stacking detecting means 15, and the loading bogie detecting means 14, respectively.
And the input operation is performed. 39 is a check valve, and 40 is a pressure gauge.

Therefore, the link operation is as follows. (1) Operate the main valve 28 with the lever to open. (2) By pressing the operation button 23 to open the lift control valve 30 in the closed state, the emergency stop switching valve 33 is opened.
Is operated to the cut side, the lift switching valve 34 is operated to the ascending side, and the drive air switching valve 35 is operated to the inlet side, and the pressure air from the air pressure source 27 passes through these switching valves 35, 34, 33. The air is supplied to the lift frame air cylinder 2, the lift frame 3 is raised, and the safety fence is lowered.

(3) When the lifting frame 3 is raised, the worker moves the bogie B along the bogie guide rail 5 to the machine frame 1.
Carry in. (4) When the carried-in first bogie B is detected by the carried-in bogie detecting means 14, the closed bogie detection control valve 38 is opened, and the lift switching valve 34 is operated to the lower side.
The supply of pressurized air from the air pressure source 27 is stopped, and the pressurized air of the lift frame air cylinder 2 is removed, whereby the lift frame 3 is lowered by its own weight, and the bogie B is automatically moved by the bogie holding claw 4. Is taken into the lifting frame 3.

(5) When the lifting frame 3 reaches the lower limit position and is detected by the lower frame lower limit detecting means 16, the lower end detection control valve 36 is opened, and the switching valve 34 for raising and lowering is moved upward. Since the operation is performed, the pressurized air is supplied to the lift frame air cylinder 2 to raise the lift frame 3 and the first carriage B
Hoist.

(6) Next, the second carriage B is described above.
A carriage similar to (3) is carried in. (7) For the second bogie B, the lowering of the lifting / lowering frame air cylinder and the loading of the hoisting frame by the carry-in bogie detecting means 14 in (4), and the lifting of the hoisting frame in (5) above. An operation of linking (lifting the cart) is performed. (8) By repeating the above operation, a predetermined number (for example, 4
) Are taken into the machine frame 1 in a stacked state. The lifting frame 3 can be lowered from the upper holding position by pressing the forcible lowering button 24 to open the forcibly lowering control valve 31.

(9) The first bogie B at the uppermost stage is detected by the predetermined number of bogies stacking detecting means 15, and after the stacked bogies are held in an up state, the predetermined number of bogies stacking detection control valve. 37 is input to open the drive air switching valve 3
5 is operated to the cut side, the elevating switching valve 34 is operated to the descending side, the elevating frame 3 is lowered, and a predetermined number of bogies B are stacked on the bogie guide rails 5 in the machine frame 1 and in a standby state. Becomes Further, when the drive air switching valve 35 is operated to the cut side, pressure air is supplied to the air cylinder 18 for the safety fence,
The safety fence 17 is in a raised state. (10) When the stacking completion push button 25 is pressed, the stacking completion control valve 32 is opened, the driving air switching valve 35 is operated to the cut side by the pressure air from the air pressure source 27, and the lifting frame 3 is moved. It descends to the descending limit and forcibly ends the stacking.

(11) In the event of an emergency, the emergency stop button 22 is pressed to release the emergency stop control valve 2.
9 is opened, the emergency stop switching valve 33 is switched to the entrance side by the pressure air from the air pressure source 27, and the operation of the lifting frame air cylinder 2 is stopped.

In the above embodiment, the air cylinder is used as the lifting drive source. However, it is needless to say that another lifting drive source such as a hydraulic cylinder or an electric cylinder may be used. In the above-described embodiment, the carts are stacked in four stages. However, the present invention is not limited to this, and it is needless to say that other plural stages such as three-stage stacking and five-stage stacking may be used.

[0035]

According to the stacking device of the present invention, stacking of empty trolleys can be performed automatically and efficiently, positioning between the trolleys is easy, and displacement of the stacking is relatively small. This has the effect of increasing the degree of safety, greatly reducing the fatigue of workers, and reducing the number of workers. Further, in the case of using a lifting frame air cylinder as the lifting drive source, there is an effect that automation of work by air pressure driving is facilitated with equipment having a relatively simple configuration. When the carriage is taken in and held by the rotating claw of the lifting frame,
This has the effect of facilitating the stacking of trolleys with simple equipment that does not require power.

When the stop portion and the introduction portion are provided on the truck guide rail, there is an effect that the loading and positioning of the truck are facilitated. When the positioning space is provided on the bogie guide rail, there is an effect that the positioning of the stacking bogie is further facilitated. When the lifting frame air cylinder is of the self-weight lowering type, there is an effect that the problem that the lifting frame does not stop during an emergency stop is eliminated.

If the lifting and lowering operation of the lifting frame can be performed in cooperation with the detection means such as the loading carriage detection means, there is an effect that automation of the work by the air pressure circuit becomes easy.
When all operations are stopped by the emergency stop control valve in an emergency, the air cylinder operation can be instantaneously stopped just by pressing the emergency stop button in an emergency, and there is an effect that work safety is high. When using a trolley provided with a stacking engaging portion, positioning operation during stacking can be performed safely and quickly,
There is an effect that the restacking operation due to the displacement is eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a bogie stacking device according to the present invention.

FIG. 2 is a perspective view of a cart.

FIG. 3 is a perspective view of carts stacked in four stages.

FIG. 4 is a plan view of a bogie stacking device according to the present invention.

FIG. 5 is a front view of the bogie stacking device according to the present invention.

FIG. 6 is a perspective view showing a lifting frame and a carriage holding claw portion.

FIG. 7 is an operation explanatory view of the bogie stacking device according to the present invention;
(A) is a figure which shows the state which lifted the 1st cart, (b)
Is a diagram showing a state where the first cart and the second cart are stacked,
(C) is a view showing a state in which a two-tiered lifting frame is lifted, and a third bogie is carried below the elevating frame.
It is a figure showing the state where it was piled up.

FIG. 8 is an air pressure circuit diagram of the bogie stacking device according to the present invention.

[Description of Signs] A bogie stacking device 1 machine frame 2 elevating frame air cylinder 3 elevating frame 3a legs 3b lower member 4 bogie holding claws 5 bogie guide rails 5A, 5B rail material 5a bogie stop portion 5b bogie introduction portion Reference Signs List 6 Inlet opening 8 Positioning space 9 Bending confirmation plate 12 Piston rod 13 Lifting frame guide unit 14 Carrying vehicle detecting means 15 Predetermined number of trucks Stacking detecting means 16 Lifting frame lower limit detecting means 17 Safety rail 18 Air cylinder for safety rail Reference Signs List 20 Safety cover 21 Operation unit 22 Emergency stop button 23 Operation button 24 Forced lowering button 25 Stacking completion button 27 Air pressure source 28 Main valve 29 Emergency stop control valve 30 Elevating operation control valve 31 Forced lowering control valve 32 Stacking Completion control valve 33 Emergency stop switching valve 34 Lifting / lowering switching valve 35 Drive air switching valve B Bogie 41 Free Arms 43,44 Axles 46 Handles 47,48

Claims (10)

[Claims] 1. A bogie stacking device for stacking a predetermined number of bogies, comprising a gate-shaped hoisting frame provided in a machine frame so as to be able to move up and down, a hoisting drive source for driving the hoisting frame up and down, At least two pairs of front and rear bogie holding claws provided at the lower end portions of both legs of the elevating frame and capable of moving forward and backward on opposite sides and capable of lifting and holding the bogie, and an entrance of the main body frame at the bottom of the main body frame A bogie guide rail extending from the opening to the back, driving the elevating drive source, loading a subsequent bogie below the bogie lifted by the hoisting frame and the bogie holding claw, and stacking the bogies. A bogie stacking device. 2. The lifting drive source is an air cylinder for a lifting frame that is vertically provided on an upper surface of a central portion of the machine frame, wherein the lifting frame is connected to a piston rod of the air cylinder for the lifting frame. The bogie stacking device according to claim 1, characterized in that: 3. The carriage holding claw is always horizontal, and cannot be rotated downward, and can be rotated upward by 90 ° around an installation base by an external force from below. The bogie stacking device according to claim 1 or 2, wherein the bogie is capable of moving back and forth to the opposite side by being provided. 4. The bogie guide rail is characterized in that an end on the entrance opening side is a wide and descending bogie introduction portion, and a rear end is inclined upward to form a bogie stop portion. The bogie stacking device according to claim 1, 2 or 3. 5. A truck positioning space is provided by widening a rail material of the truck stopping portion outwardly, and a front wheel of the truck stops in the truck positioning space. 4. The bogie stacking device according to 4. 6. The bogie according to claim 2, wherein the lifting frame air cylinder is a single-acting air cylinder that moves up and down by its own weight by supplying pressurized air. Stacking equipment. 7. An air pressure circuit for performing a lifting / lowering operation of the lifting frame by the lifting / lowering frame air cylinder in cooperation with a carry-in vehicle detection unit, a predetermined number of vehicles, a stacking detection unit, and a lifting frame lowering limit position detection unit. The bogie stacking device according to any one of claims 2 to 6, wherein: 8. The bogie stacking device according to claim 7, further comprising an emergency stop control valve that shuts off the pressurized air and stops all operations in the air pressure circuit in an emergency. 9. The safety fence according to claim 1, wherein a safety fence is provided at an entrance opening of the machine frame so as to move up and down in conjunction with elevating the elevating frame. Dolly stacking device. 10. The truck according to claim 1, wherein said truck having a plurality of standing stack engaging portions which are positioned to abut against the lower end portion of the upper truck when stacking is stacked. The bogie stacking device according to any one of the above.