JP3268071B2 - Pallet transport cart - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport trolley for transporting a work 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 machining centers are connected to perform unattended operation machining, a workpiece is placed on a pallet, and the pallet is transported into and out of a machine tool or the like by a carrier cart. The transfer between machines is being performed. As the transport trolley, a transport trolley in which the pallet loading height is constant has been predominant.

[0003]

However, in the case of a carrier having a constant pallet loading height, there has been a problem that the pallet transfer position of the machine tool must be the same throughout the entire line. To solve this problem,
As disclosed in Japanese Patent Publication No. 4-50226,
Transport vehicles having a lift mechanism for adjusting the height of pallet loading have been devised. In the carriage having the above-described lift mechanism, a claw-like fork pin (engaging portion) provided on a fork table for carrying in / out the pallet is hooked on the pallet, the fork table is slid in, carried in / out, and the fork pin is pulled out. That means is adopted,
Fork pins were attached to and detached from the pallet, and a fork pin lifting device was provided on the lift table. However, since the ascending / descending direction of the fork pin is the same as the ascending / descending direction of the lift table, providing a separate fork pin driving device wastes the driving device and causes a problem that the mechanism becomes complicated.

[0004] Further, in a transport trolley in which the type of the pallet is determined on the transport trolley by a dog provided on the pallet, the fork table may not move due to a structural problem of a mechanism for moving the fork table (particularly, a double-size mechanism). There is a problem in that the pallet cannot be accurately positioned on the transporting trolley, and the discriminating device for discriminating the dog and the dog are displaced from each other to cause a malfunction such that a correct pallet type cannot be discriminated. Was.

[0005]

[Means for Solving the Problems]

The present invention solves the above-mentioned conventional problems.
For this purpose, a support bracket fixed on a transport trolley and positioning and fixing the pallet to the transport trolley, a lift table disposed on the transport trolley and movable up and down with respect to the support bracket, and the lift table A lift drive device for raising and lowering, a fork table disposed on the lift table and mounting the pallet, an engaging portion fixed on the fork table and positioning the pallet on the fork table, A fork driving device for moving the fork table to a position below the pallet support portion of the pallet transfer table, and a discriminating device provided on the lift table for discriminating a dog indicating information necessary for processing provided on the pallet the door <br/> Bei example, by lowering the front SL lifting tables, the supporting bracket The pallet is positioned on the conveyance carriage Ri, der ones and performing discrimination of the dog provided on the pallet by the discriminating device in this state
You.

[0007]

The operation of transferring a pallet to a machine tool, such as a machining center, will be described separately for loading and unloading. Now, the transport trolley on which the pallet is placed lowers the lift table to the lowest point and engages the support bracket with the pallet, thereby positioning and supporting the pallet on the transport trolley.

In the case of loading a pallet, the transport trolley on which the pallet received the call instruction is placed travels to a predetermined position on the called machine tool with the pallet positioned on the transport trolley as described above. Then, the lift table is raised so that the height of the pallet support provided on the pallet delivery table of the machine tool is equal to the height of the fork table. Then, the pallet is no longer engaged with the support bracket, and the pallet can be moved in the loading / unloading direction by moving the fork table. The fork drive is driven to cause the fork table to enter the pallet delivery table. Accordingly, 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 is delivered from the fork table. The fork driving device is driven to return the fork table to the carriage side, the lift table is lowered to the lowest point, and the pallet loading process is completed.

Next, in the case of unloading the pallet, the transporting trolley on which the pallet received the call command is not loaded travels to the predetermined position of the called machine tool with the lift table lowered to the lowest point. The lift drive device is driven to raise the lift table to a predetermined position where the fork table is lower than the pallet support of the machine tool. The fork driving 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 height of the pallet support of the machine tool and the height of the fork table of the carrier are equal. Then, the pallet is engaged by the engaging portion. When the fork table is moved to the carriage by driving the fork driving device, the pallet caught by the engaging portion is pulled by the fork table and moved to the carriage. When the pallet returns to the predetermined position on the carrier, the lift table is lowered to the lowest point, the support bracket is engaged with the pallet, the pallet is positioned and supported on the carrier, and the pallet unloading process is completed. Pallet
Engage with the support bracket and position it on the carrier
Indicates the information required for processing provided on the pallet
The dog is determined by the determination device.

[0010]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a line of a certain process of an FMS production line using the transport vehicle of the present embodiment. 100
Reference numeral denotes a transport carriage of the present embodiment, 101 denotes a processing machine, 102
Is a loading device for supplying the workpieces loaded on the pallet P, and 103 is a conveyor for transporting the workpieces to another process line. Reference numeral 61 denotes a traveling rail of the transport vehicle 100, which is laid on the floor in parallel with each other and serves as a traveling track of the transport vehicle 100. Reference numeral 60 denotes a rack used to detect the position of the transport trolley 100, and is laid on the floor in parallel with the trolley traveling rail 60. In the production line configured as described above, the transport trolley 100
And is transported between the processing machine 101, the loading device 102, and the conveyor 103.

FIGS. 2 and 3 are configuration diagrams showing the configuration of a pallet carrier according to an embodiment of the present invention. FIG.
FIG. 3 is a top view. A traveling drive device 1 for traveling the transport vehicle 100 itself is provided on the vehicle body 10 of the transport vehicle 100.
1. Lift drive device 2 for lifting and lowering lift table 20
1. A frame 15 for fixing a lift guide rail (not shown) for guiding the lifting and lowering operation of the lift table 20, a traveling encoder 14 for detecting the current position of the carrier 100, and a support for positioning a pallet on the carrier 100. The bracket 90 is fixed, and the traveling wheels 13a and 13b of the carrier 100 are attached. By driving the traveling driving device 11, the traveling vehicle 13 is rotated so that the traveling vehicle 100 can travel on the rail 61 in the X-axis direction by the traveling driving wheel 13a and the traveling driven wheel 13b. Has become. A pinion 14 a is attached to a rotating portion of the traveling encoder 14, and meshes with a rack 60 laid in parallel with the rail 61, so that the carrier 100 travels, so that the pinion 14 a
a rotates to detect the position of the transport vehicle 100 in the production line.

A lift table 20 for raising and lowering the pallet P is mounted on the upper surface of the carriage body 10 to the frame 15 via a lift guide rail (not shown) so as to be movable in the Z-axis direction. A lift encoder 1 for detecting the position of the lift table 20 is provided on the frame 15.
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 has been detected. The lift table 20 has notches 2
The support bracket 90 is fixed to the bogie main body 10 through the notch hole 20b. Thus, the support bracket 90 does not hinder the lifting and lowering of the table 20 during the lifting and lowering operation of the lift table 20. 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. This lift mechanism is a link 2
4 and a link 25 having the same length. The links 24 and 25 intersect at the center of each other to form an X shape, and are supported by pins 29 so as to be swingable with each other. The lift table 20 is raised and lowered by increasing or decreasing the angle of intersection of the links 24 and 25.

One end of the link 24 is connected to the bogie body 10 with a pin 2
4a, the other end of which is supported by a pin 24 in an elongated hole 20a provided on the side surface of the lift table 20.
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 connecting rods 27.
Is screwed. The link support member 26 is moved by rotating the ball screw 28. The ball screw 28 is connected to a lift drive device 21 fixed to the upper surface of the carriage body 10.

When the lift drive device 21 is driven, the ball screw 28 rotates, and the link support member 26 is moved via the connecting rod 27. Accordingly, one end of the pinned link 24 moves in the elongated hole 20a. Then, the intersection angle between 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 pin 91 is provided at the tip of the support bracket 90 described above. The height of the support bracket 90 is set so that the pallet guide pin fits into the knock hole 81 provided on the back surface of the pallet P when the lift table 20 is lowered to the lowest point. . Then, as shown in FIG. 5, when the lift table 20 is lowered to the lowest point (solid line portion in the drawing), the pallet guide pins 91 are fitted into the knock holes 81, and the pallet P is inserted into the bogie main body 20. It is designed to support positioning. When the lift table 20 is raised above the height of the pallet guide pin 91 (height n in the drawing), the pallet guide pin 91 is disengaged from the knock hole 81 to fix the pallet P. It is designed to be released.

As shown in FIGS. 2 and 3, a pallet guide rail 40,
The fork base 30, the fork driving device 33, and the pusher device 50 are fixed. Pallet guide rail 40
The pallet P contacts the lower surface of the pallet P to support the weight of the pallet P, and the pallet P slides on the pallet guide rails 40 to guide when the fork is carried in / out.

As shown in FIG. 6, 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 mounted on 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 at the center of the upper surface of the fork table 37. On the other hand, fork pin holes 80
The pallet P is hooked on the fork table 37 to be carried in and out by being fitted to the fork pin 31.

Next, the fork mechanism will be described. A sprocket (not shown) is attached to the tip of a shaft 34 connected to the fork driving device 33, and the shaft 3
5 is connected via a chain 38 to a sprocket (not shown) attached to one end of the shaft 5 to transmit the power of the fork driving device 33 to the shaft 35. On the other hand, a pinion 35 a is attached to the other end of the shaft 35, and meshes with a rack 32 a attached to the lower surface of the fork guide table 32 to drive the fork guide table 32. When the fork guide table 32 moves, the fork table 37 moves by a double mechanism that moves the fork table 37 in the same direction by an amount twice the amount of the movement. This magnification mechanism will be described with reference to FIG.

A fork guide table 32 is movably mounted on a fork table 30 fixed to the lift table 20, and a fork table 37 is movably mounted on 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 rack 32a is engaged with the pinion 35a. And
The fork guide table 32 is moved by the rotation of the pinion 35a driven by the fork driving device 33. Chain 3 on fork table 37
One end of each of the chains 32c and 32c is fixed.
c and 32c are opposite ends of the fork guide table 32 , respectively.
Sprockets 32b , 3 rotatably mounted at the ends
2b , it is fixed to the fork base 30. Now
The fork driving device 33 is driven to move the fork guide table 32 by a distance d in the Y-axis direction as shown in FIG. 6B. Then, the sprocket 32b is also moved by the distance d. One end of the chains 32c , 32c is a fork stand
It is fixed to 30, the fork table 37 right
It is pulled by the side chain 32c and moves on the fork guide table 32 by a distance of d. Then, as a result, the fork table 37 becomes Y
That is, the displacement is 2d in the axial direction. Based on the above principle, a double-size mechanism is formed. Incidentally, the fork drive device 33 is constituted by a servo motor and an encoder, fork Guy
Detection of the position of the de-table 32 is made by detecting the rotational displacement of the servo motor by the encoder.

As shown in FIG. 3, two pusher devices 50 are placed on the lift table 20 in opposite directions. 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 provided. Press the switch.

Here, the mechanism of the pallet retaining device will be described with reference to FIG. Reference numeral 200 denotes a pallet delivery table provided in the processing machine 101 or the like, and reference numeral 240 denotes a pallet guide rail (pallet support portion) laid on the pallet delivery table 200. This pallet guide rail 240
(The direction perpendicular to the plane of FIG. 4) is set to a height that allows the fork table 37 to enter and move up and down as described later. The pallet delivery table 200
Stopper 20 1 Z type is swingably supported 201a as the center axis. One end of the stopper 201 is turned off click 201b to affix the pallet P, the other end 201
One end of the transmission rod 202 is in contact with c. Transmission rod 20
Reference numeral 2 is attached to the pallet transfer table so as to be displaceable in the Y-axis direction. Also, the stopper 201 of the transmission rod 202
A switch plate 204 is attached to one end on the opposite side to form a switch of the pallet retaining device. Further, a spring 201 having one end fixed to the 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. (FIG. 7A). Now, when the pusher 51 is extended and pushes the switch plate 204, 201c which is one end of the stopper 201 is pushed via the transmission rod 202, swings the stopper 201, the hook 201b is removed from the pallet P, and the pallet P Release the fixation (FIG. 7B). Further, the pusher 51 is contracted and the switch board 20 is
4A, the stopper 201 is returned to the state shown in FIG. The pallet removal prevention device is configured as described above.

On one side of the pusher device 50, a pallet P and a pallet discriminating device 85 and a workpiece discriminating device 8 for discriminating the type of a work placed on the pallet P
6 is attached. FIG. 10A is a side view of the pallet P. On the side of the pallet P, a pallet discriminating dog 95 for discriminating the type of the pallet P and the type of the work placed on the pallet P are shown. A work identification dog 96 for identification is fixed. The pallet discriminating dog 95 and the workpiece discriminating dog 96 are provided with holes 95a at predetermined positions on an iron plate. The combination of the presence or absence of the holes 95a and the holes 96 indicates the types of the pallet P and the workpiece, respectively. ing. The pallet discriminating device 85 and the workpiece discriminating device described above each include a plurality of unillustrated photoelectric tubes.
As shown in [B], the presence / absence of holes 95a and 96a in the pallet discrimination dog 95 and the workpiece discrimination dog 96 is detected, and the pallet P and the type of the workpiece are detected.

Next, the operation of the present embodiment will be described with reference to FIGS. FIG. 8 is a cycle diagram showing the process of loading and unloading the pallet P superimposed on the path of the fork pin 31. In the figure, the solid line indicates the movement of the lift table 20, the broken line indicates the movement of the fork table 37, and the dashed line indicates the traveling of the carrier 100.
FIG. 9 shows the lift table 2 in loading / unloading of the pallet P.
FIG. 6 is a model diagram showing the operation of a fork table 37 with 0.

First, the loading of the pallet P will be described. Now, the lift table 20 of the carrier 100 on which the pallet P is placed is lowered to the lowest point, and the support bracket 9
The pallet guide pin 91 at the leading end is fitted in the knock hole 81 of the pallet P, and the pallet P is positioned on the bogie main body 10. In FIG. 8A, the pallet P
Is received at a position i1 which is an arbitrary position on the track. Then, the transport vehicle 100 drives the vehicle drive device 11 to travel the transport vehicle 100 to a predetermined position i2 (step a1).
The type of the pallet P and the workpiece to be carried in from here during this traveling is determined by the pallet determining device 85 and the workpiece determining device 86, respectively. Lift drive 2
1 to raise the lift table 20 so that the pallet guide rails 40 on the side of the carrier 100 and the pallet guide rails 240 on the pallet delivery table 200 of the processing machine 101 are at the same height (step a2). At this time,
When the pallet P rises to the height n, the pallet guide pin 91 is disengaged from the knock hole 81, and the positioning of the pallet P from the bogie main body 10 is released. Next, the pusher 51 is extended at the position i3 to release the stopper 201 of the pallet transfer table 200 (see FIG. 7B). When the fork driving device 33 is driven to move the fork table 37 forward to the position shown in FIG. 9 [2] by the above-described double-size mechanism, the pallets P caught on the fork pins 31 slide on the pallet guide rails. While being carried into the pallet delivery table 200 (step a3). At the position i4, the pusher 51 is contracted, and the pallet P is fixed to the pallet delivery table 200 by the stopper 201 (see FIG. 7A). By driving the lift driving device 21, the lift table 20 is lowered by h (a displacement amount larger than the protrusion amount of the fork pin 31), and FIG.
The fork table 37 is lowered to the position shown in [3] (step a4). Then, fork pin 3 from pallet P
1 comes off and the pallet P is delivered. The fork driving device 33 is driven to retreat the fork table 37 of the double-size mechanism to the transport trolley 100 as shown in FIG. Then, lift table 20 is moved to the lowest point (position i7).
And the loading cycle ends (step a6). Step a7 is a step of transporting to the next machine tool 101 or the like.

Next, the unloading of the pallet P will be described. In FIG. 8B, the transport vehicle 100 on which the pallet P is not placed receives a call instruction at a position j1 which is an arbitrary position on the track. Then, the transport vehicle 100
Drives the carriage traveling drive unit 11 to travel the carriage 100 to a predetermined position j2 (step b1). The pallet guide rail 40 at the position shown in FIG.
The lift table 20 is raised to a position j3 lower by h than the pallet guide rail 240 on the pallet transfer table 200 of No. 01 (step b2). Next, the fork driving device 33 is driven to advance the fork table 37 to the position shown in FIG. 9 [3], and the fork pin 31 is positioned so as to be located directly below the fork pin hole 80 (step b3). By driving the lift drive device 21, the position shown in FIG. 9B, that is, the pallet guide rail 40 on the side of the transport vehicle 100 and the pallet delivery table 200 of the processing machine 101.
The lift table 20 is raised to a position where the upper pallet guide rails 240 are at the same height (step b4). Then, the fork pin 31 is fitted to the pallet P. At the position j5, the pusher 51 is extended and the pallet delivery table 20 is extended.
The 0 stopper 201 is released (see FIG. 7B). The fork driving device 33 is driven to a position shown in FIG.
When the fork table 37 is retracted, the fork pins 3
The pallet P hooked on the pallet 1 slides on the pallet guide rails 40 and 240 and is carried out of the pallet delivery table 200 (step b5). The pusher 51 is contracted at the position j6, and the lift table 20 is lowered to the lowest point (position j7). Then, knock hole 81 of pallet P
Is fitted to a pallet guide pin 91 at the tip of the support bracket 90, and the pallet P is positioned on the bogie main body 10. Then, in this state, the types of the pallet P and the workpiece that have just been carried out are determined by the pallet determining device 85 and the workpiece determining device 86, respectively. Thus, the unloading cycle is completed. Step b7 is a step of transporting to the next machine tool 101 or the like. The above cycle is performed by each processing machine 10
The pallet P is conveyed by performing the pallet P using the loading device 102 and the loading device 102 or the like.

As described above, the transport vehicle 100 of this embodiment is
It has a lift table 20 for raising and lowering the pallet P, and has a structure capable of coping with a processing machine 101 having a pallet transfer table 200 having different heights. Also, the attachment and detachment of the fork pin 31 to and from the pallet P is
This has the advantage that it is not necessary to separately provide a fork pin lifting device in order to perform the lifting operation. Further, a support bracket 90 is provided on the bogie body 10, and the lift table 2 is provided.
By lowering 0 to the lowest point, the pallet P
Since it can be positioned at 0, the following effects are obtained. That is, since the pallet P is positioned on the carriage main body 10 by the lifting and lowering operation of the lift table 20, the pallet P can be positioned and supported without providing a special driving source.
Since the types of the pallet P and the workpiece W can be determined in this state, it is possible to avoid an erroneous type determination caused by a positional shift of the pallet determining dog 95 and the workpiece determining dog 96 due to a positional shift of the pallet P. Also,
Since the pallet P can be fixed to the trolley body 10 when the transport trolley 100 travels, rattling of the pallet P generated during traveling can be prevented, and the friction of the fork double mechanism can be reduced.

[0027]

As described above, according to the present invention, by providing a lift table for raising and lowering a pallet on a transport trolley, it is possible to cope with a pallet transfer table having a different height. By also using the lifting and lowering operation of the lift table, a device for raising and lowering the engaging portion can be omitted, and there is an advantage that the mechanism can be simplified.

Further, a pallet can be positioned on the carrier by providing a support bracket on the carrier and lowering the lift table, which has the following effects. That is, since the positioning operation of the pallet on the carriage body 10 is performed by the elevating operation of the lift table, the pallet can be positioned and supported without providing a special driving source. And
Since the dog provided on the pallet can be determined while the pallet is positioned and supported, the dog can always be determined at an accurate fixed position, and the erroneous determination of the determination device caused by the displacement of the pallet can be avoided. In addition, since the pallet can be fixed to the bogie main body when the pallet transport cart travels, there is an effect that pallet rattling occurring during traveling can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a production line using a transport vehicle according to an embodiment.

FIG. 2 is a side view of the overall configuration diagram of the transport vehicle according to the present embodiment.

FIG. 3 is a top view of the overall configuration diagram of the transport vehicle according to the present embodiment.

FIG. 4 is a detailed view of a lift table mechanism according to the present embodiment.

FIG. 5 is a detailed view showing a pallet positioning mechanism of the present embodiment.

FIG. 6 is a detailed view of a double-size fork mechanism of the present embodiment.

FIG. 7 is a detailed view of a pallet retaining mechanism according to the present embodiment.

FIG. 8 is a cycle diagram showing the steps of loading and unloading the pallets according to the present embodiment superimposed on the trajectory of the fork pin.

FIG. 9 is a model diagram showing the operation of a lift table and a fork table in loading and unloading pallets according to the present embodiment.

FIG. 10 is a detailed view of the pallet discriminating apparatus of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 Lift table 20b Notch hole 21 Lift drive device 31 Fork pin 32 Fork guide table 33 Fork drive device 37 Fork table 51 Pusher 80 Fork pin hole 81 Dowel hole 85 Pallet discriminator 86 Workpiece discriminator 90 Support bracket 91 Pallet guide pin 95 Pallet identification dog 96 Workpiece identification dog 200 Pallet delivery table 240 Pallet guide rail P Pallet

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-194861 (JP, A) JP-A-1-115542 (JP, A) JP-A-57-201156 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B23Q 7/00

Claims (1)

(57) [Claims] To 1. A pallet delivery table provided in each of the plurality of machine tools, the pallet supporting member for supporting the pallet mounted with the workpiece is provided, travels between the plurality of machine tools, the In a carrier for carrying the pallet into and out of the pallet delivery table, a support bracket fixed on the carrier and positioning and supporting the pallet on the carrier, disposed on the carrier,
A lift table that can move up and down with respect to the support bracket, a lift drive device that moves the lift table up and down, a fork table that is disposed on the lift table and that mounts the pallet, and that is fixed on the fork table An engagement portion for positioning the pallet on the fork table, a fork driving device for moving the fork table to a position below the pallet support portion of the pallet delivery table, and the pallet provided on the lift table. A discriminating device for discriminating dogs indicating information necessary for processing provided in the pallet. The pallet is positioned by the discriminating device in this state by lowering the lift table to position the pallet on the support bracket. Pallet transport characterized by determining the dog provided in Truck.