JP2023102878A - Workpiece stocker and work-piece discriminating method - Google Patents

Abstract

To provide a work-piece stocker which can discriminate pallets on which work-pieces before processing and work-pieces after processing are mounted respectively.SOLUTION: A work-piece stocker includes: a pallet transfer device configured to transfer a plurality of pallets mounted with work-pieces and arranged circumferentially; a pallet lifting device configured to lift one having stopped at a delivering position, of the pallets, where the automatic loader delivers the workpiece; a work-piece discriminating device which includes detection means for detecting the workpiece mounted on the pallet at the delivering position; a dummy work-piece configured to be directly mounted on one of the pallets and stacked with the work-pieces thereon and formed in a shape that avoids detection of the detection means; and a control device which drive-controls the pallet transfer device and the pallet lifting device.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to a workpiece stocker and a workpiece discrimination method capable of distinguishing whether a pallet carries an unmachined workpiece or a machined workpiece returned after machining.

In a processing machine line that sequentially transports and processes workpieces, a workpiece stocker is used to load workpieces before machining, collect workpieces after machining, or both. An autoloader is installed in such a processing machine line, and the work is automatically delivered to a machine tool, a work stocker, or the like by the autoloader. At that time, when the workpiece stocker is to take out unprocessed workpieces and receive processed workpieces, it is necessary to determine which workpiece is loaded on the pallet.

Patent Document 1 listed below discloses a work stocker having a work discriminating device as follows. The workpiece discriminating device has a proximity switch provided inside a loop-shaped rail, and a gauge that moves up and down by a cylinder is provided on the upper part of the rail. The workpieces stacked in the workpiece stocker are grasped by the workpiece hand, and the type of the workpiece is discriminated by the proximity switch of the workpiece discriminating device and the gauge of the cylinder. As a result, confirmation with the processing information in the machine tool is performed, and erroneous processing can be prevented.

JP-A-60-076941

In the above conventional example, even the type of workpiece is discriminated. However, the problem this time is to make it possible to determine whether the pallet contains pre-machined workpieces or machined workpieces. Although it is possible to use the conventional work discriminating device for such problems, it is difficult to assemble a work discriminating device equipped with a proximity switch or a cylinder equipped with a gauge on a stocker with limited space. Therefore, significant improvements to current work stockers are required. On the other hand, in the configuration for discriminating the type of workpiece, it becomes necessary to change the settings for each different workpiece.

Therefore, in order to solve the above problems, an object of the present invention is to provide a workpiece stocker and a workpiece determination method that can determine whether the pallet is loaded with unprocessed workpieces or processed workpieces.

A workpiece stocker according to the present invention includes a pallet moving device for moving a plurality of pallets on which workpieces are mounted in a circumferential arrangement, a pallet lifting device for lifting and lowering the pallet stopped at a delivery position where an autoloader delivers the workpiece, a workpiece discrimination device equipped with a detection means for detecting the workpiece mounted on the pallet at the delivery position, a dummy workpiece that is directly placed on one of the pallets and the workpieces are stacked thereon, and has a shape that avoids detection by the detection means, the pallet moving device, and the pallet lifting device. and a control device for driving and controlling the device.

Further, the method for discriminating workpieces for a workpiece stocker according to the present invention includes a pallet moving device for a workpiece stocker that moves a plurality of pallets side by side on a circular track, in which a dummy workpiece having a shape that avoids detection by a detection means for detecting workpieces is placed on one of the pallets, and unprocessed workpieces are loaded on all of the other pallets; It has a work transfer process in which finished works are loaded, an empty pallet arranged at the transfer position, and a work determination process of determining that a processed work is mounted on the subsequent pallet when the subsequent pallet on which the dummy work following the pallet is mounted is continuously detected by the detection means.

According to the above configuration, by setting only one empty pallet among a plurality of pallets and mounting the dummy work, at the stage when all the pre-machining works are processed, the pallet on which the dummy work is mounted is kept in a continuous state with the empty pallet, so that it can be confirmed that the pre-machining work and the processed work have been replaced in the work stocker.

1 is a front view showing a processing machine line including one embodiment of a work stocker; FIG. FIG. 4 is a simplified plan view of the work stocker showing the pallet moving device; It is a simplified side view of the work stocker showing the pallet moving device. It is a side view which shows a workpiece|work discrimination|determination apparatus. It is a figure which shows the workpiece|work discrimination|determination method using the workpiece|work discrimination|determination apparatus of one Embodiment for a workpiece|work stocker. FIG. 10 is a reference diagram of a workpiece discrimination method for a workpiece stocker; FIG. 10 is a reference diagram of a workpiece discrimination method for a workpiece stocker;

An embodiment of a workpiece stocker and a workpiece discrimination method according to the present invention will be described below with reference to the drawings. The work stocker of this embodiment is configured as a part of the processing machine line 10 shown in FIG. FIG. 1 is a front view showing a processing machine line 10, which consists of a workpiece stocker 1 and two machine tools 2 and 3. As shown in FIG. A workpiece stocker 1 and two machine tools 2 and 3 are arranged side by side, and an autoloader 4 is provided inside for transferring workpieces W between them. The autoloader 4 has a robot hand capable of gripping the workpiece W at the tip of the multi-joint robot, and is movable within the transfer space formed in front of the machine tools 2 and 3 .

A workpiece stocker 1 is loaded with unprocessed workpieces and processed workpieces processed by machine tools 2 and 3 . That is, pre-machined works are loaded into the work stocker 1, carried out one by one, machined by the machine tools 2 and 3, and then returned as machined works, where the pre-machined works are replaced with the machined works. The work stocker 1 stacks a plurality of works W on a pallet in the machine, and is provided with a pallet moving device 7 for sending the works W to a delivery position P for the autoloader 4 .

FIG. 2 is a simplified plan view of the work stocker 1 showing the pallet moving device 7, and FIG. 3 is a side view of the work stocker 1 as well. The pallet moving device 7 moves a plurality of pallets 13 along an oval track in the circumferential direction, and is provided on a base 9 that constitutes the work stocker 1 . In the pallet moving device 7, three long positioning pins 12 are pushed upward from a traveling table 11, and the pallet 13 is mounted on the traveling table 11 so as to be constrained by the positioning pins 12.例文帳に追加

The disc-shaped pallet 13 has three radially formed slits 131 , and is mounted on the traveling table 11 while being pierced by three positioning pins 12 . Such a pallet 13 can be moved in the vertical direction while maintaining a horizontal posture without lateral displacement due to the positioning pins 12, and a plurality of works W are stacked thereon.

In the pallet moving device 7, a plurality of carriages 11 are connected to an endless roller chain 15 indicated by a dashed line in FIG. A pair of sprockets 16 are pivotally supported at both ends of the oval track in the longitudinal direction, and a roller chain 15 is stretched thereon. A sprocket 16 on the rear side of the fuselage serves as a driving side, and a moving motor 17 is connected to the rotating shaft thereof. When a moving motor 17 is driven and its output is transmitted to a roller chain 15 through a sprocket 16, a plurality of traveling bases 11 are simultaneously moved in the circumferential direction along an oval track so as to be pulled by the rotating roller chain 15. - 特許庁

A transfer position P is provided on the track of the traveling table 11 for transferring the work W to and from the autoloader 4 . The delivery position P is located in the front part of the body, and as shown in FIG. 1, the robot hand of the autoloader 4 can enter from the side of the body cover. The transfer of the work W by the autoloader 4 shown in FIG. 1 is always performed at the transfer position P at a constant height. Therefore, the work stocker 1 is provided with a pallet lifting device 8 at the transfer position P. As shown in FIG.

Although not shown in detail, the pallet lifting device 8 is configured such that, for example, a lifting chain hung on a sprocket in a base 9 is driven by a lifting motor, and a lifting plate connected to the lifting chain moves up and down. Therefore, a plurality of shafts erected on the lifting plate move up and down, and the pallet 13 placed on the tip of the shaft moves up and down while maintaining its posture by the positioning pin 12. - 特許庁The pallet lifting device 8 is provided with a workpiece discrimination device 6 for adjusting the height of the lifting pallet 13 .

FIG. 4 is a side view showing the work discriminating device 6. As shown in FIG. Photoelectric sensors 21 and 22 are provided in the workpiece discrimination device 6 . The light sensor 21 detects the height when the autoloader 4 picks up the unprocessed work from the pallet 13, and the photoelectric sensor 22 detects the height when the autoloader 4 transfers the processed work onto the pallet 13. In the workpiece discriminating device 6, two support rods 25 and 26 are erected on a base 9 so as to sandwich the pallet 13 at the delivery position P, and an arm 27 and an arm 28 are horizontally attached to each of them at a predetermined height.

The photoelectric sensor 21 has a light projector 21a mounted on one arm 27 and a light receiver 21b mounted on the other arm 27 at the same height, and the photoelectric sensor 22 has a light projector 22a mounted on one arm 28 and a light receiver 22b mounted on the other arm 28 at the same height. In the work stocker 1 of this embodiment, a new function is added to the work discriminating device 6 described above. That is, while the works W mounted on a plurality of pallets 13 arranged in the circumferential direction change from the unprocessed works W1 to the processed works W2, it is configured to be able to determine which pallet 13 is mounted.

For this purpose, a photoelectric sensor 23 attached to the lower part of the support bar 25 is used, like the photoelectric sensors 21 and 22 . This photoelectric sensor 23 is adjusted to the height of the first work W directly mounted on the pallet 13 at the lowered position, and a light projector 23a is attached to one arm 29 and a light receiver 23b is attached to the other arm 29 at the same height. A dummy work DW is directly placed on one of the plurality of pallets 13 . The dummy work DW has a shape that avoids detection by the photoelectric sensor 23, and is formed so that the detection light passes through the small diameter portion below the two-stage shape having different diameters as shown in the figure.

The dummy work DW is designed to allow detection light, which would be blocked if it were a work W, to reach the light receiver 23b from the light projector 23a. The work W has various shapes. Therefore, it is necessary to prepare a dummy work DW corresponding to this, but the shape is not limited as long as the work W can be stacked in a correct posture and the detection light of the photoelectric sensor 23 is not blocked. It should be noted that the passage position of the detection light can be adjusted by adjusting the attachment state of the light projector 23a and the light receiver 23b with respect to the dummy work DW. That is, the position of the arm 27 can be adjusted by up and down or turning with respect to the support rod 25, and the light projector 23a and the light receiver 23b can be attached to the arm 27 whose orientation is adjusted.

The work stocker 1 is provided with a control device for controlling the driving of the pallet moving device 7, the pallet lifting device 8, and the like. A driving program is stored in the storage part to move a plurality of pallets 13 to a transfer position P at a predetermined timing, and at the transfer position P, it is possible to adjust the elevation position with respect to the pallet 13 based on the detection signal of the workpiece discriminating device 6.例文帳に追加In this embodiment, it is possible to determine that the workpiece W on the pallet 13 has changed from the unprocessed workpiece W1 to the processed workpiece W2, particularly based on the detection signal of the photoelectric sensor 23 (the detection signal when the light is shielded and when the light is not shielded).

Here, FIGS. 6 and 7 are reference diagrams of the work discriminating method for the work stocker similar to this embodiment. First, the reference workpiece determination method shown in FIG. 6 will be described. Here, one empty pad 13A on which no work W is placed is prepared, and all the other pallets 13 are loaded with pre-machining works W1. Processing is then started, and the unprocessed work W1 is taken out from the pallet 13B at the delivery position P by the autoloader 4 (S11). Next, the empty pallet 13A is moved to the transfer position P by the reverse rotation (counterclockwise movement) of the roller chain 15 (S12), and the machined work W2 machined by the machine tools 2 and 3 is returned there (S13).

Then, the unprocessed work W1 is taken out from the pallet 13B moved to the transfer position P by the forward rotation (clockwise movement) of the roller chain 15 (S14), and the processed work W2 is received by the pallet 13A by the reverse rotation of the roller chain 15 (S13, S14). As a result, a predetermined number of processed works W2 are stacked on the pallet 13A, and when it is confirmed that there is no unprocessed work W1 on the pallet 13B (S15), the roller chain 15 rotates forward (S16), and the operations from steps S11 to S15 are repeated between the empty pallet 13B and the pallet 13C on which the unprocessed works W1 are stacked (S17).

By repeating the above operations, a predetermined number of processed works W2 are stacked on the pallets 13A to 13K, the final pallet 13L becomes empty (S18), and all the unprocessed works W1 on the work stocker are replaced with the processed works W2. However, if a means for discriminating the situation is not provided, the machined work W2 mounted on the pallet 13A is erroneously judged as the unmachined work W1, and is taken out by the autoloader 4 and sent to the machine tools 2 and 3 again. Therefore, it is necessary to use a work discriminating device like the conventional example, but it is difficult to install it on the narrow base 9 .

Next, a workpiece discrimination method shown in FIG. 7 for solving such problems will be described. Here, two empty pads 13A and 13B are prepared, and all the other pallets 13 are loaded with pre-machining works W1. Therefore, as in the case shown in FIG. 6, first, the unmachined work W1 is transferred as the machined work W2 machined by the machine tools 2 and 3 between the empty pallet 13B and the adjacent pallet 13C (S21-S25). Thereafter, a predetermined number of machined works W2 are similarly stacked on the pallets 13C to 13K, and the empty pallet 13L and the empty pallet 13A prepared as a mark are continued (S26-S28).

When it is confirmed that there is no unprocessed work W1 on the pallet 13L (S28), the roller chain 15 rotates forward, and the empty pallet 13A moves to the delivery position P. Therefore, it is continuously confirmed that there is no pre-machining work W1, and it is determined that all the pre-machining works W1 mounted first have been processed (S29). Therefore, the interlocking autoloader 4 and machine tools 2 and 3 are stopped, and the operator is notified using a signal tower or a monitor. With such a workpiece discrimination method, it is possible to prevent the machined workpiece W2 from being reworked without adding a new structure. However, one pallet 13 is wasted, and the processing efficiency is lowered.

Next, a workpiece discrimination method according to the present embodiment, which solves the problems described above, will be described. First, in the work stocker 1 , the feeding amount of the roller chain 15 is set by controlling the rotation of the moving motor 17 by controlling the driving of the pallet moving device 7 . A plurality of pallets 13 are moved in the machine by the simultaneous movement of the traveling table 11, and a predetermined pallet 13 is positioned at the delivery position P according to the delivery of the work W. Presence or absence of a workpiece W is confirmed on the pallet 13 by a detection signal from the photoelectric sensor 23 . When the work W can be confirmed, the pallet 13 is lifted by the pallet lifting device 8 and positioned at the height at which the top work W is detected by the detection signal of the photoelectric sensor 21 .

After the unprocessed work W1 is taken out by the autoloader 4, the receiving pallet 13 is moved to the transfer position P, and the pallet lifting device 8 lifts the pallet 13. As shown in FIG. The uppermost work W is positioned at the height detected by the detection signal of the photoelectric sensor 22, and the machined work W machined by the machine tools 2 and 3 is returned there. By sending out and receiving the workpieces W in this way, the unmachined workpieces W1 stacked in the workpiece stocker 1 are replaced with the machined workpieces W2 as the machining progresses. FIG. 5 is a diagram showing a workpiece discrimination method using the workpiece discrimination device 6 in the workpiece stocker 1. As shown in FIG.

In this embodiment, one empty pad 13A is prepared, on which a dummy work DW is placed, and on all other pallets 13, pre-machining works W1 are placed. Processing is started in a state in which the pallet 13A is positioned one step ahead of the delivery position P in the traveling direction (clockwise). A work W1 to be machined is taken out from the pallet 13B by the autoloader 4 and machined by the machine tools 2 and 3 (S1). Next, the pallet 13A is moved to the delivery position P by the reverse rotation of the roller chain 15 (S2), and the machined workpiece W2 is returned there and superimposed on the dummy workpiece DW (S3).

Thereafter, the unprocessed works W1 are taken out from the pallet 13B and the processed works W2 are loaded onto the pallet 13A, and the pallet 13B from which all the unprocessed works W1 have been taken out becomes empty (S1-S5). Similarly, unprocessed works W1 and processed works W2 are loaded on pallets 13C to 13L, and the last pallet 13L is emptied (S6-S8). Then, the pallet 13A stacked with the processed works W2 is moved to the transfer position P by the forward rotation of the roller chain 15. As shown in FIG.

At this time, if the machined work W2 is directly mounted on the pallet 13A, the work is confirmed by the detection signal of the photoelectric sensor 23, and as in the case shown in FIG. However, the dummy work DW is mounted on the pallet 13A, and the detection light from the light projector 23a slips past the dummy work DW and reaches the light receiver 23b, so that it is erroneously determined that the work W1 before machining is not mounted and is empty (S9). The controller determines that the work W mounted on the pallet 13A arranged at the delivery position P is the machined work W2 because the pallet 13A continues to be empty following the empty pallet 13L. That is, the control device determines that all the pre-machining works W1 loaded on the work stocker 1 have been processed.

Therefore, in this embodiment, as in the case shown in FIG. 6, only one empty pallet 13 is provided, and as in the case shown in FIG. 7, the empty pallets 13 are made to appear to be continuous, so that the pallet 13 on which the unprocessed work W1 and the processed work W2 are respectively mounted can be discriminated. That is, it can be confirmed that the pre-machined work W1 loaded in the work stocker 1 has been replaced with the machined work W2. Moreover, the effect can be achieved without making any significant improvements to the conventional work stocker.

Although one embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the scope of the invention.
For example, the dummy work DW in the above-described embodiment has the two-tiered lower small-diameter portion facing downward, but it may be upside down depending on the height of the light detected by the photoelectric sensor 23. Further, if a configuration that enables phase determination is added on the pallet 13, an optical path passing through the center portion may be formed.
Moreover, although the photoelectric sensor 23 was shown and demonstrated as a detection means in the said embodiment, you may use another sensor.

REFERENCE SIGNS LIST 1 Work stocker 2, 3 Machine tool 4 Autoloader 6 Work discriminating device 7 Pallet moving device 8 Pallet lifting device 10 Processing machine line 13 Pallet 15 Roller chain 21, 22, 23 Optical sensor 21a, 22a, 23a Projector 21b, 22b, 23b Receiver P Delivery position W Work W1 Work to be processed W2 Work completed DW…Dummy work

Claims (4)

a pallet moving device that arranges and moves a plurality of pallets on which workpieces are mounted;
a pallet lifting device for lifting and lowering the pallet stopped at the delivery position where the autoloader delivers the work;
a work discriminating device comprising detection means for detecting a work mounted on the pallet at the delivery position;
a dummy work which is directly placed on one of the pallets and has a shape to avoid detection by the detection means;
a control device that drives and controls the pallet moving device and the pallet lifting device;
work stocker. The workpiece discriminating device has two support rods that sandwich the pallet placed at the delivery position, and a light projector and a light receiver are attached to horizontally extending arms of the same height to detect workpieces of a predetermined height.
2. A workpiece stocker according to claim 1, wherein said dummy workpiece has a shape through which detection light from a light projector to a light receiver, which is blocked if it is a workpiece, passes through. 3. The workpiece stocker according to claim 2, wherein said dummy workpiece is formed so that detection light passes through a lower small-diameter portion of a two-tiered shape having different diameters. In a pallet moving device for a work stocker that moves a plurality of pallets side by side on a circular track, a dummy work having a shape that avoids detection by a detection means for detecting the work is mounted on one of the pallets, and pre-machining works are mounted on all of the other pallets;
a work transfer step in which the pallet stopped at the transfer position on the track for transferring the work to the autoloader is lifted and lowered by a pallet lifting device, and the autoloader picks up the work before machining and loads the machined work;
a workpiece determination step of determining that a machined workpiece is mounted on the subsequent pallet when an empty pallet placed at the delivery position and a subsequent pallet on which the dummy workpiece is mounted following the pallet are continuously detected by the detection means;
A workpiece discrimination method for a workpiece stocker having

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