JPH06179146A - Pallet conveying truck - Google Patents

Abstract

PURPOSE:To simplify the mechanism for carrying-in/out a pallet without installing an elevator device for a fork pin, by carrying out the transport-in/out of the pallet at the position corresponding to the height of each machine tool, as for a conveying truck which conveys workpieces placed on the pallet between a plurality of machine tools. CONSTITUTION:A pallet conveying truck is equipped with a lift driving device for raising and lowering a lift table 20 arranged on the conveying truck, fork table 37 which is arranged on the lift table 20 and places a pallet, and a fork driving device which shifts the pallet P to the pallet receiving/delivering board of a machine tool by hooking a fork pin 31 installed on the fork table 37 with the pallet and shifting the fork table 37. The pallet P is conveyed to/from the machine tool, etc., according to the combination of the driving operations of the lift table 20 and the fork table 37.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier truck for carrying a workpiece placed on a pallet to a plurality of machine tools such as machining centers.

[0002]

2. Description of the Related Art In an FMS in which a plurality of machine tools such as a machining center are connected to perform unmanned operation machining, a workpiece is placed on a pallet, and the pallet is carried in and out of a machine tool or the like by a carriage. Transport between machines is in progress. As the carrier truck, a carrier truck with a constant height of pallet loading was mainly used.

[0003]

In the case of a carrier truck in which the height of pallet loading is constant, there is a problem that the pallet transfer position of the machine tool must be set to the same height in the entire line. To solve this problem,
As disclosed in Japanese Patent Publication No. 4-50226,
A carrier truck having a lift mechanism for adjusting the height of pallet loading has been devised. In the carrier truck having the lift mechanism described above, the fork pins (engaging portions) provided on the fork table for loading and unloading the pallet are hooked on the pallet, the fork table is slid in and out, and the fork pin is pulled out. Has been adopted,
A fork pin lifting device was provided on the lift table for attaching and detaching the fork pin to the pallet. However, since the ascending / descending direction of the fork pin is the same as the ascending / descending direction of the lift table, providing the fork pin driving device separately is a waste of the driving device and causes a problem that the mechanism becomes complicated. Therefore, an object of the present invention is to simplify the mechanism by eliminating the pallet loading / unloading and the fork pin elevating / lowering device to the position corresponding to the height of each machine tool.

[0004]

In order to solve the above-mentioned conventional problems, the present invention provides a lift table disposed on a carrier, a lift drive device for moving the lift table up and down, and a lift table on the lift table. A fork table on which a pallet is placed, an engagement portion fixed on the fork table for positioning the pallet on the fork table, and the fork table down to the pallet support portion of the pallet delivery table. And a fork drive device that moves the pallet, and carries in and out the pallet by a combination of the driving operations of the lift table and the fork table.

[0005]

The operation of carrying a pallet to a machine tool such as a machining center will be described separately for the carrying-in and carrying-out steps. In the case of pallet loading, the carrier carrying the pallet receiving the call command moves the lift table so that the height of the pallet support part provided on the pallet delivery table of the machine tool and the fork table are equal. While traveling, it travels to a predetermined machine tool position. The fork table is driven into the pallet delivery table by driving the fork drive device. Along with this, the pallet engaged with the engaging portion provided on the upper surface of the fork table is pulled by the fork table and moved to the pallet delivery table. Next, the lift drive device is driven to lower the lift table. Then, the fork table that has entered the pallet delivery table is lowered, and the engaging portion is disengaged from the pallet. At this time, the pallet is placed only on the pallet support portion of the pallet delivery table and delivered from the fork table. The fork drive device is driven to return the fork table to the dolly side, and the pallet loading process is completed.

Next, in the case of pallet unloading, the carrier table on which the pallet that received the call command is not placed has the lift table so that the fork table of the carrier vehicle is lower than the pallet support portion of the machine tool. While moving, it travels to a predetermined machine tool position. The fork drive device is driven to cause the fork table to enter the pallet delivery table so that the engaging portion is located directly below the pallet. Next, the lift table is raised to a position where the heights of the pallet support of the machine tool and the fork table of the carrier are equal. Then, the pallet is engaged by the engaging portion. When the fork drive device is driven to move the fork table to the dolly side, the pallet hooked by the engaging portion is pulled by the fork table and moved to the transport dolly. The fork table is returned to the trolley to complete the pallet unloading process.

[0007]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a certain process line of an FMS production line using the carrier of the present embodiment. 100
Is a carrier truck of the present embodiment, 101 is a processing machine, and 102
Is a loading device for supplying the workpieces loaded on the pallet P, and 103 is a conveyor for transporting the workpieces to the line of another process. Reference numeral 61 is a rail for traveling of the carrier truck 100, which is laid on the floor in parallel with each other and is a track on which the carrier truck 100 travels. A rack 60 is used to detect the position of the carriage 100, and is laid on the floor in parallel with the carriage rail 60. In the production line configured as described above, the carrier 100 transports the workpieces to the pallet P.
The sheets are stacked in the state of being placed on the sheet, and are conveyed between the processing machine 101, the loading device 102, and the conveyor 103.

2 and 3 are structural views showing the structure of a pallet carrier according to an embodiment of the present invention. FIG. 2 is a side view,
FIG. 3 is a top view. The carriage body 10 of the carriage 100 has a travel drive device 1 for running the carriage 100 itself.
1. Lift drive device 2 for raising and lowering the lift table 20
1. A frame 15 for fixing a lift guide rail (not shown) for guiding the lifting operation of the lift table 20, a travel encoder 14 for detecting the current position of the transport carriage 100 are fixed, and further, the transport truck 100 travels. Wheels 13a and 13b are attached. Carrier 100
Drive the traveling drive wheels 13a by driving the traveling drive device 11, and the traveling drive wheels 13a and the driven wheels 13b can travel on the rail 61 in the X-axis direction. . Further, a pinion 14a is attached to the rotating portion of the traveling encoder 14, and the pinion 14a rotates by meshing with a rack 60 laid parallel to the rail 61 and the transport carriage 100 traveling, thereby rotating the pinion 14a. The position of the carriage 100 is detected.

A lift table 20 for raising and lowering the pallet P is mounted on the upper surface of the carriage main body 10 so as to be movable in the Z-axis direction on the frame 15 via a lift guide rail (not shown). Further, the frame 15 has a lift encoder 1 for detecting the position of the lift table 20.
6, a rack (not shown) fixed to the lift table 20 meshes with a pinion (not shown) attached to the lift encoder 16, and the pinion is rotated to rotate the pinion. The position is being detected. Here, the lift mechanism of the lift table 20 will be described with reference to FIG. 4, which is a cross-sectional view taken along the line AA ′ of FIG. 1. This lift mechanism is composed of a rod-shaped link having the same length of the link 24 and the link 25,
The links 24 and 25 intersect each other at their centers to form an X shape, and are supported by a pin 29 so as to be swingable with respect to each other. Then, the lift table 20 is moved up and down by increasing or decreasing the angle of intersection of the links 24 and 25.

One end of the link 24 is a pin 2 on the carriage body 10.
4a is swingably supported, and the other end is provided with a pin 24 in an elongated hole 20a provided on the side surface of the lift table 20.
supported by b. On the other hand, one end of the link 25 is swingably supported by the lift table 20 by a pin 25b, and the other end is swingably supported by a link support member 26 by a pin 25a. The link support member 26 is attached to the carriage body 10 so as to be movable in the X-axis direction. The link support members 26 are connected to each other by a connecting rod 27, and the connecting rod 27 has a ball screw 28.
Are screwed together. Then, as the ball screw 28 rotates, the link support member 26 is moved. Further, the ball screw 28 is connected to a lift drive device 21 fixed to the upper surface of the carriage body 10.

With the above structure, when the lift driving device 21 is driven, the ball screw 28 is rotated to move the link support member 26 via the connecting rod 27. Along with this, one end of the link 24 pinned moves in the elongated hole 20a. Then, the crossing angle of the links 24 and 25 is increased or decreased, and as a result, the lift table 20 is moved up and down.

A pallet guide rail 40, a fork base 30, a fork drive device 33 and a pusher device 50 are fixed to the upper surface of the lift table 20. The pallet guide rail 40 is in contact with the lower surface of the pallet P to support the weight of the pallet P, and the pallet P slides and guides on the pallet guide rail 40 when carrying in and out the fork.

As shown in FIG. 5, a fork guide table 32 is attached to the fork base 30 so as to be movable in the Y-axis direction. Further, a fork table 37 is attached to the upper surface of the fork guide table 32 so as to be movable in the Y-axis direction, and a fork pin 31 (engaging portion) is fixed to the center of the upper surface of the fork table 37. On the other hand, the lower surface of the pallet P has a fork pin hole 80.
Is formed, and by fitting with the fork pin 31, the pallet P is hooked on the fork table 37 to be carried in and out.

Next, the fork mechanism will be described. An unillustrated sprocket is attached to the tip of the shaft 34 connected to the fork drive device 33.
5 is connected via a chain 38 to a sprocket (not shown) attached at one end thereof, and the power of the fork drive device 33 is transmitted to the shaft 35. On the other hand, a pinion 35 a is attached to the other end of the shaft 35, and the rack 3 attached to the lower surface of the fork guide table 32.
The fork guide table 32 is driven by meshing with 2a. Also, fork guide table 3
When 2 moves, the displacement amount which is twice the displacement amount is moved by the scale mechanism in which the fork table 37 moves in the same direction. This scale mechanism will be described with reference to FIG.

A fork guide table 32 is movably attached to a fork base 30 fixed to the lift table 20, and a fork table 37 is movably attached to the fork guide table 32. The rack 32a is attached to the lower surface of the fork guide table 32 as described above, and the pinion 35a is meshed with the rack 32a. And
The fork guide table 32 is moved by the rotation of the pinion 35a driven by the fork drive device 33. Chain 3 on the fork table 37
One end of 2c is fixed, and the other end of the chain 32c is fixed to the fork base 30 via a sprocket 32b rotatably attached to the lift guide table 32. Now, the fork drive device 33 is driven to move the fork guide table 32 by a distance d in the Y-axis direction as shown in FIG. 5B. Then, the sprocket 32b is also moved by the distance d. Since one end of the chain 32c is fixed to the fork base, the fork table 37 is pulled by the chain 32c and the fork guide table 3
Move on top of 2 a distance of d. As a result, the fork table 37 is displaced with respect to the fork base 30 by 2d in the Y-axis direction. A double-scale mechanism is formed based on the above principle. The fork drive device 33 is composed of a servo motor and an encoder, and is provided with a fork table 32.
The position is detected by detecting the rotational displacement of the servo motor with the encoder.

As shown in FIG. 3, two pusher devices 50 are mounted on the lift table 20 in directions opposite to each other. Further, inside the pusher device 50, a pusher 51 is attached to a cylinder (not shown) so as to expand and contract in the Y-axis direction, and by extending the pusher 51, a pallet retaining device provided in a processing machine or the like described later is installed. It is designed to press a switch.

Now, the mechanism of the pallet retainer will be described with reference to FIG. Reference numeral 200 is a pallet delivery table provided on the processing machine 101 and the like, and 240 is a pallet guide rail (pallet support portion) laid on the pallet delivery table 200. This pallet guide rail 240
4 (the direction perpendicular to the paper surface of FIG. 4) is set to such a height that the fork table 37 can enter and move up and down as described later. The pallet delivery table 200 has
A Z-shaped stopper 201 is swingably supported with 201a as a central axis. One end of the stopper 201 serves as a hook 201b for fixing the pallet P, and the other end 20
One end of the transmission rod 202 is in contact with 1c. Transmission rod 2
02 is attached to the pallet delivery table so as to be displaceable in the Y-axis direction. In addition, the stopper 20 of the transmission rod 202
A switch plate 204 is attached to one end on the side opposite to 1, forming a switch of the pallet retaining device. Further, a spring 201 having one end fixed to a pallet delivery table is attached to the stopper 201, and normally (when the pusher 51 is not pressing the switch plate 204), the stopper 200 is kept at a position where the hook 201b fixes the pallet P. It is leaning (Fig. 6 [A]). Now, when the pusher 51 extends and pushes the switch plate 204, one end 201c of the stopper 201 is pushed through the transmission rod 202, swings the stopper 201, and the hook 201b is removed from the pallet P. The fixation is released (Fig. 6 [B]). Also, the pusher 51 contracts and the switch plate 20
When separated from 4, the stopper 201 is returned to the state shown in FIG. 6A by the spring 203. The pallet retaining device is configured as described above.

Next, the operation of this embodiment will be described with reference to FIGS. 7 and 8. FIG. 7 is a cycle diagram in which the process of loading and unloading the pallet P is superimposed on the trajectory of the fork pin 31. In the figure, the solid line means the movement of the lift table 20, the broken line means the movement of the fork table 37, and the alternate long and short dash line means the traveling of the carrier vehicle 100.
FIG. 8 shows a lift table 2 for loading and unloading the pallet P.
It is a model diagram showing the action of 0 and the fork table 37.

First, the loading of the pallet P will be described. In FIG. 7 [A], the carrier 100 on which the pallet P is placed receives a call command at a position i1 which is an arbitrary position on the track. Then, the carrier 100 drives the lift drive device 21 to move the lift table 20 so that the pallet guide rail 40 on the carrier 100 side and the pallet guide rail 240 on the pallet transfer table 200 of the processing machine 101 are at the same height. Rise (process a
2). The trolley-driving drive device 11 is driven to drive the transport trolley 100 to a predetermined position (step a3). At this time, since the steps a2 and a3 are actually performed at the same time, the fork pin 31 moves along the locus of the double line a23, as shown in FIG.
Reach position [1]. Next, pusher 5 at position i4
1. Stopper 201 of pallet delivery table 200
Is canceled (see FIG. 6B). Fork drive device 33
When the fork table 37 is moved forward by the above-described scale mechanism to the position shown in FIG. 8 [2], the pallet P hooked on the fork pin 31 slides on each pallet guide rail, Delivery table 20
It is carried into 0 (step a5). Pusher 5 at position i6
1 is contracted and the pallet P is fixed to the pallet delivery table 200 by the stopper 201 (see FIG. 6A). The lift drive device 21 is driven to lower the lift table 20 by h (a displacement amount larger than the protrusion amount of the fork pin 31),
The fork table 37 is lowered to the position shown in FIG. 8 [3] (step a7). Then, the fork pin 31 comes off from the pallet P, and the pallet P is delivered. When the fork drive device 33 is driven to retract the fork table 37 of the double-scale mechanism to the transport carriage 100 as shown in FIG. 8 [4], the carry-in cycle ends (step a8). Process a
Reference numeral 9 is a step of transporting to the next machine tool 101 or the like.

Next, unloading of the pallet P will be described. In FIG. 7B, the carriage 100 on which the pallet P is not placed receives a call command at a position j1 which is an arbitrary position on the track. Then, the carriage 100 drives the lift drive device 21 to move to the position shown in FIG.
That is, the pallet guide rail 40 on the carrier 100 side
However, the lift table 20 is moved up and down to a position lower than the pallet guide rail 240 on the pallet delivery table 200 of the processing machine 101 by h (step b2). The carriage driving device 11 is driven to move the carriage 10 to a predetermined position.
The vehicle travels 0 (step b3). At this time, actually b2
Since the step b3 is performed at the same time, the fork pin 31 moves along the locus of the double line b23. Next, the fork drive device 33 is driven to advance the fork table 37 to the position shown in FIG. 8 [3], and the fork pin 31 is positioned so as to be located directly below the fork pin hole 80 (step b4). The lift drive device 21 is driven, and FIG.
The lift table 20 is raised to the position shown in [2], that is, the position where the pallet guide rail 40 on the side of the carrier 100 and the pallet guide rail 240 on the pallet transfer table 200 of the processing machine 101 have the same height (step b).
5). Then, the fork pin 31 is fitted to the pallet P. The pusher 51 is extended at the position j6 to release the stopper 201 of the pallet transfer table 200 (FIG. 6 [B]).
reference). When the fork drive device 33 is driven and the fork table 37 is retracted to the position shown in FIG. 8 [1], the pallet P hooked on the fork pin 31 slides on the pallet guide rails 40, 240. , And is delivered from the pallet delivery table 200 (step b7). At the position j8, the pusher 51 is contracted to end the carry-out cycle. Step b9 is a step of carrying to the next machine tool 101 or the like.

The pallet P is conveyed by performing the above cycle by each processing machine 101, the loading device 102 and the like. Finally, the effect of this embodiment will be described. The carrier vehicle 100 in this embodiment has a lift table 20 for moving the pallets P up and down, and has a structure that can be applied to the processing machine 101 having the pallet delivery tables 200 having different heights. Moreover, since the fork pin 31 is attached to and detached from the pallet P by the lifting operation of the lift table 20, there is an advantage that a separate fork pin lifting device is not required. Further, since the pusher device 50 is provided on the carrier, it is not necessary to provide a driving device for the pallet retaining device on each processing machine. There is also an advantage that the width of the carriage main body 10 can be narrowed by using the double-scale mechanism.

[0022]

As described above, according to the present invention, by providing a lift table for raising and lowering a pallet on a carrier, it is possible to deal with pallet delivery tables having different heights, and the engaging portion can be attached to and detached from the pallet. Since the lifting table is also used for lifting and lowering operations, a device for lifting and lowering the engaging portion can be omitted and the mechanism can be simplified.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a production line using a carrier truck according to the present embodiment.

FIG. 2 is a side view of an overall configuration diagram of a carrier truck according to the present embodiment.

FIG. 3 is a top view of an overall configuration diagram of a carrier truck according to the present embodiment.

FIG. 4 is a detailed view of a lift table mechanism of this embodiment.

FIG. 5 is a detailed view of the double-sized fork mechanism of this embodiment.

FIG. 6 is a detailed view of a pallet retainer mechanism of this embodiment.

FIG. 7 is a cycle diagram showing a process of loading and unloading a pallet of the present embodiment, which is overlapped with a locus of a fork pin.

FIG. 8 is a model diagram showing the operation of a lift table and a fork table during loading and unloading of pallets according to the present embodiment.

[Explanation of symbols]

 20 Lift Table 31 Fork Pin 32 Fork Guide Table 37 Fork Table 51 Pusher 200 Pallet Delivery Platform 240 Pallet Guide Rail P Pallet

Claims (1)

[Claims] 1. A pallet transfer table provided for each of a plurality of machine tools is provided with a pallet support member for supporting a pallet on which a workpiece is placed, and the pallet support member travels between the plurality of machine tools. In a carrier truck that carries in and out the pallet to and from a pallet delivery table, a lift table disposed on the carrier truck, a lift drive device that raises and lowers the lift table, and a pallet disposed on the lift table. A fork table to place
The lift includes: an engaging portion fixed on the fork table, for positioning the pallet on the fork table, and a fork drive device for moving the fork table below the pallet supporting portion of the pallet delivery table. A pallet carrier for carrying in and out the pallet by a combination of driving operations of a table and the fork table.