JPH06277992A - Automatic production line - Google Patents

Abstract

PURPOSE:To prevent the deterioration of an operation rate of a line by arranging a processing means to start carrying-in of an unprocessed work held by a machine tool in the process as well as to send a processed work to a succeeding process out of relation to the timing in which the processed work is sent from a preceding process when a machine tool in the preceding process is stopped. CONSTITUTION:When a detecting means 18 detects that a machine tool 12 in a preceding process is operated normally, the first processing means starts processing of an unprocessed work held by a work holding means while interlocking with the timing in which a processed work is sent from the machine tool 12 in the preceding process, and sends the processed work to a machine tool 14 in a succeeding process. When the detecting means 18 detects that the machine tool 12 in the preceding process stops a function due to a trouble or the like, the second processing means starts carryingin of the unprocessed work out of relation to the timing in which the processed work is sent from the machine tool 12 in the preceding process, and sends the processed work to the machine tool 14 in the succeeding process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the conveyance of workpieces on an automatic production line provided with machine tools having different cycle times.

[0002]

2. Description of the Related Art Conventionally, in an automatic production line in which a plurality of machine tools having different cycle times are arranged and the machine tools are connected to each other by a transfer device, the machine tools produced by the difference in cycle time between the machine tools. In order to eliminate the stock of the workpiece, the control for starting the machining and the transportation of the machine tool in the process is performed in association with the transportation of the workpiece that has completed the machining in the previous process. At that time, each machine tool completes the machining of the unmachined workpiece and its machine tool that have not been machined in order to facilitate the machining and transportation of the workpiece and increase the line operation rate of the entire line. It is possible to hold several machined workpieces.
That is, each machine tool sends the machined work held in the machine tool to the post process for the first time when the machine tool of the previous process sends the machined work to the machine tool of the process. At the same time, control was performed to start machining of the unmachined workpiece held in the machine tool of the process (hereinafter, control for performing machining of the process in conjunction with the conveyance of the workpiece from the preceding process. Is called push priority control).

[0003]

When the workpiece is machined and conveyed by the push priority control, the workpiece can be sent without generating a fluid inventory of the machine tool, but on the other hand, for example, in a line. If one machine tool is stopped due to a cutting tool replacement or failure, the entire line will stop functioning. That is, the machine tool in the preceding step from the stopped machine tool processes the workpieces up to the number that can be stored on the transfer device or in the machine tool, but when this is reached, it becomes impossible to carry out the workpiece and the function is stopped. . In addition, since the machine tool in the post-process of the stopped machine tool is not loaded from the previous process, the machine tool is in a waiting state for the unprocessed machine, and as a result, all machine tools in the post-process are stopped from the machine tool stopped. Stop functioning. This allows the 1
When two machine tools stopped functioning, the entire line stopped functioning, resulting in a problem that the line operating rate was significantly reduced.

Therefore, in order to solve the above-mentioned problems, according to the present invention, even if the machine tool in the line is stopped due to a failure or the like, the machine tool in the post process is supplied with the workpiece from the stopped machine tool, The purpose is to provide an automatic production line that prevents the decline of operating rate as much as possible.

[0005]

The automatic production line of the present invention is, as means for achieving the above-mentioned object, an unprocessed work piece that has not been processed in the process and a processed work piece that has been processed in the process. Holding means for holding at least one of the above, a detecting means for detecting whether the machine tool in the previous step is operating normally, and the machine tool in the previous step being operating normally by the detecting means. When it detects that the unprocessed work held by the work holding means is started in synchronization with the timing at which the processed work is sent from the machine tool in the previous process, The first processing means for sending the processed workpiece held by the object holding means to the machine tool in the subsequent step, and the detection means for stopping the machine tool in the previous step, Regardless of the timing at which the processed workpiece is sent from the machine tool in the previous step, loading of the unprocessed workpiece held by the workpiece holding means is started, and processing held by the workpiece holding means is started. At least one machine tool provided with the second processing means for sending the finished workpiece to the machine tool in the subsequent process is arranged in the line.

[0006]

When the detection means detects that the machine tool in the previous step is operating normally, the first processing means sends the processed workpiece from the machine tool in the previous step to the processed workpiece. The processing of the unprocessed workpiece held by the workpiece holding means is started in synchronism with the above, and the processed workpiece held by the workpiece holding means is sent to the machine tool in the subsequent process. On the other hand, when the detection means detects that the machine tool of the previous process is stopped due to a failure or the like, the second processing means causes the processed workpiece from the machine tool of the previous process to be sent. Regardless, the processing of the unprocessed workpiece held by the workpiece holding means is started, and the processed workpiece held by the holding means is sent to the machine tool in the subsequent process. Since at least one machine tool that operates as described above is installed in the production line, when the machine tool in the process prior to that process is operating normally, the work piece is removed without generating a fluid inventory. Send to the process, and when the process before that process is stopped, send the workpiece to the process after that process,
Prevents the entire line from stopping.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing an overall configuration of an automatic production line showing an embodiment of the present invention. 10 is a material supply device for supplying the material of the work to the following machine tool 11,
Reference numerals 11, 12, 13, and 14 are machine tools including a processing machine, a cleaning machine, a heat treatment machine, and the like. Denoted at 15 and 17 are conveying devices including conveyors and robot manipulators for conveying the workpieces that have been processed in the process between the machine tools. The machine tools 11, 12, 13, 14 are controlled by the sequence controllers PC1, PC2, PC3, PC4 for machining and carrying of the respective workpieces.

The sequence controllers PC1, PC2, PC4 of the machine tools 11, 12, 14 store a push-priority control program for starting machining when a workpiece is loaded from the previous process described in the prior art. , When the processed product of the previous process machine tool is introduced, the machined work piece of the machine tool in that process is sent to the machine tool of the next process, and the unprocessed work piece in the machine tool is machined. There is.

Sequence controller P of machine tool 13
C3 stores a control program, which is a feature of the present embodiment, in which a push priority control program and a pull priority control described later are combined. When the machine tool in the line is functioning normally, the push priority control is performed. The machine tool 13 is controlled by the machine tool in the previous process in the production line (the machine tool 11 or the machine tool 12 in this embodiment).
When the function stops, the machine tool 13 is controlled by the pull priority control. This pull priority control is the processing of the unprocessed workpiece held in the machine tool of the process even if the workpiece is not loaded from the previous process when the machine tool of the previous process stops. This control is to carry out the processed workpiece, and the details will be described later.

Further, a reserved workpiece sensor 18 (detection means) provided on the transfer device 17 by a connection 16 is attached to the sequence controller PC3.
The reserved workpiece sensor 18 detects whether or not the workpiece W from the machine tool 12 has been sent to the transport device 17,
It is designed to determine whether the machine tool in the previous process is operating normally.

FIG. 2 is a diagram showing the details of the machine tool 13 as an example of the machine tools 11, 12, 13, and 14. The machine tool 13 is a grinder, and a bed 21 has a grindstone 22.
And a table 24 is provided. The grindstone base 22 is attached so as to be movable in the vertical direction in the drawing, and is driven by a drive device (not shown). The grindstone 23 is attached to the grindstone base 22 and is rotated by a drive device (not shown). Has become. The table 24 is attached so as to be movable in the left-right direction in the drawing, and is moved by a drive device (not shown).

A headstock 25 and a tailstock 26 are disposed on the table 24, and a workpiece W is attached via a jig 27.
The work piece is rotated by a drive device (not shown) provided on the headstock 25. Then, the workpiece is ground by the above-described configuration. On the front surface of the machine tool 13 (downward in the drawing), the carrying device 1
7 (15) is provided with an internal transport device 30 for transporting the workpiece W in the machine tool 13 so that the workpiece W is transported in the arrow T direction. Further, the first, second, and third workpiece confirmation sensors 31, 32, and 33 are attached to the internal transfer device 30.
The first workpiece confirmation sensor 31 detects whether or not the workpiece sent from the previous step (in this case, the machine tool 12) has been loaded into the position A of the internal transfer device 30, and the second workpiece is detected. The object confirmation sensor 32 detects the presence / absence of a non-machined workpiece at the position C, and the third workpiece confirmation sensor 33 detects the presence / absence of a machined workpiece at the position G of the transfer device to machine the sequence controller PC3. It sends an object recognition signal. However, only the first workpiece confirmation sensor 31 is attached to the machine tools 11, 12, and 14.

Further, on the bed 21, there is provided a loader 28 for loading and unloading the workpiece W to and from the jig 27.
The loader 28 grips the workpiece W at the position C of the internal transport device 30 and loads the workpiece W inside the jig 27 to carry in the jig 27 and the internal transport device 30.
It is composed of a carry-out arm 28b which carries out to a position C. The loader 28 and the internal transfer device 30 constitute a workpiece holding device 40, which constitutes the workpiece holding means in the claims.

Next, push priority control and pull priority control will be described. The first processing means in the claims indicates push priority control, and the second processing means indicates pull priority control. FIG. 3 is a flowchart showing the operation of the push-priority control machine tool, and FIG. 5 is a model diagram showing the operation of the machine tool 11.

Focusing now on the operation of the machine tool 11, the machine tool 11 is initially in the state shown in FIG. 5 [A0]. That is, the unprocessed workpiece W is placed on the internal transfer device 30.
5, W6 and processed workpieces W1, W2 are placed. The unprocessed workpiece W is attached to the loading arm 28a of the loader 28.
4 is gripped, and the processed workpiece W3 is gripped by the carry-out arm 28b. Then, the jig 27 is in a state without a workpiece.

In step 101, the internal transfer device 30
It is determined whether or not the workpiece W7 has been loaded into the (position A in FIG. 2) from the previous process. This determination is based on the first workpiece confirmation sensor 31.
When the workpiece W7 is loaded, the workpiece confirmation signal is sent to the sequence controller PC1. Conversely, if the workpiece W is not input, the workpiece W
Waiting for 7. Then, when the workpiece W7 sent from the previous process is loaded into the internal transfer device 31, the process proceeds to step 102 (state of FIG. 5 [A1]).

At step 102, the unprocessed workpiece W4 gripped by the carry-in arm 28a of the loader 28 is inserted into the jig 27 (state of FIG. 5 [A2]). Step 1
At 03, the machining of the workpiece W4 inserted in the jig 27 is started, and step 104 is executed in parallel with the machining.
In step 104, the loading arm 28 of the loader 28
a grips the unprocessed workpiece W5 on the internal transfer device 30 and stands by (state of FIG. 5 [A3]), and in step 105,
The processed workpiece W3 held by the carry-out arm 28b is carried out to the internal transfer device 30 (position C in FIG. 2) (see FIG. 5 [A
4] state). In step 106, the internal transfer device 30 is fed to the right side of the drawing by the amount of one work piece W (1 pitch), and the processed work piece W1 is sent to the machine tool in the subsequent step (state of FIG. 5 [A5]).

When it is confirmed that the machining is completed in step 107, the machined workpiece W4 is grasped by the carry-out arm 28b in step 108, and one process is completed (FIG. 5 [A6]). State). The workpiece W is processed and conveyed by repeating the above steps. In addition,
This push-priority control is performed by the machine tools 11, 12, and 14, and only the processing content of step 103 is different, and particularly the operations of the loader 28 and the internal transfer device 30 are the same. Thus, the push-priority control is control in which the machined workpiece is fed from the machine tool in the previous process, and the process is carried out and carried out.

Next, the pull priority control will be described by focusing on the machine tool 13. FIG. 4 is a flow chart showing the operation of the pull priority control machine tool, and FIG. 6 is the machine tool 13
It is a model diagram showing the operation of. At the beginning, the machine tool 13 is in the state of FIG. 5 [A0] as in the push priority control.
First, in step 201, it is determined whether or not there is a reservation for loading the workpiece W from the previous process. The determination of the reservation of loading of the workpiece W is detected by the reserved workpiece sensor 18 provided in the transport device 17, and a workpiece reservation signal is issued at the moment when the workpiece is loaded into the transport device 17, and then the workpiece is reserved. Thing W
It is determined whether or not 7 is ready to be input.

When the reservation signal is given, the routine proceeds to step 202, where the workpiece W is on standby until it is loaded into the internal transfer device 30. Then, the workpiece W7 is transferred to the internal transfer device 30.
If the second workpiece confirmation sensor is used, the presence or absence of the workpiece at the position C of the internal transfer device 30 is determined (see FIG. 2). If the work W is at the C position, the process proceeds to step 204, and if the work W is not at the C position, the process proceeds to step 213, and the conveyor of the internal transport device corresponds to one work (1 pitch) in the drawing right. Move in the direction.

When the process moves to step 204, the following operation of the machine tool 13 is performed in the same manner as the push priority control described above. That is, in step 204, the unprocessed workpiece W4 gripped by the carry-in arm 28a of the loader 28 is inserted into the jig 27 (state of FIG. 5 [A2]), and in step 205, inside the jig 27. Processing of the inserted workpiece W4 is started. In parallel with the processing of the workpiece W4, the loading arm 28a of the loader 28 grips the workpiece W5 and waits in step 206 (state of FIG. 5 [A3]), and in step 207, the unloading arm 28b grips. The processed workpiece W3 that has been processed is carried out to the internal transfer device 30 (see FIG. 5 [A
4] state). In step 208, the internal conveying device 30 is fed rightward in the drawing by one workpiece (1 pitch), and the machined workpiece W1 is sent to the machine tool in the subsequent process (state of FIG. 5 [A5]). When it is confirmed in step 209 that the machining of the workpiece W4 is completed, in step 210, the workpiece W4 that has been machined is gripped and the process returns to step 201 (see FIG.
6] state).

On the other hand, if the reservation signal is not detected in step 201, the following pull priority control is performed. Step 21
At 1, the presence or absence of the workpiece W at the positions B and C of the internal transfer device 30 is checked. The confirmation of the workpiece at the position C is performed by the second workpiece confirmation sensor 32, and the workpiece at the position B stores the presence of the workpiece at the position A in the previous machining process. Has been done. Then, if even one workpiece W is confirmed at the position B or the position C, step 2
When the work W is moved to 03 and the work W is present at the position C at 203, the work W grasped by the carry-in arm 28a is carried out in the same manner as the push priority control in steps 204 and below (see FIG. 2).
When the position D) is processed, while the workpiece W is not present at the position C (state of FIG. 6 [B1]), the process is not performed and the process proceeds to step 213 where the conveyor of the internal transfer device 30 is moved to the right in the drawing. Move one work piece (one pitch) (state of FIG. 6 [B2]).

Further, if the work W is not confirmed at the positions B and C in step 210, the process proceeds to step 210, and it is determined whether or not the processed work W at the positions F and G of the internal transfer device 30 exists. To do. The confirmation of the workpiece at the position G is performed by the third workpiece confirmation sensor 33, and the confirmation of the workpiece at the position F is to store whether the workpiece was present at the position C in the previous machining process. It is done in. Then, when the processed workpiece W is not present in both the positions F and G (state of FIG. 6 [C1]), the process proceeds to step 201 to enter the signal waiting state of the reserved workpiece, and conversely the position F. Alternatively, when the processed workpiece W exists at the position G (see FIG. 6).
In the [D1] state, the process proceeds to step 213, where the conveyor of the internal transfer device 30 is moved to the right in the drawing by one work (one pitch) and the processed work is sent to the transfer device 15 in the W post-process. (The state of FIG. 6 [D2]). The workpiece W is processed and conveyed by repeating the above steps. In this way, pull priority control means that when the machine tool of the previous process is stopped, the machined workpiece of that process is transferred to the machine tool of the subsequent process even if the machined workpiece of the previous process is not input. It is a control for feeding and processing a raw workpiece in the workpiece of the process.

Next, the flow operation of the work in the automatic production line in which the machine tool having the above-mentioned structure is arranged is shown in FIG.
It will be explained based on. FIG. 7 is a production process table showing the flow of the workpiece. In FIG. 7, MC1, MC2, MC3, and MC4 correspond to the machine tools 11, 12, 13, and 14 in FIG. 1, respectively, and are driven by push priority control.
C3 is driven by pull priority control when the loading of the workpiece from the machine tool MC2 is stopped. For simplification of description, it is assumed that the transfer devices 15 and 17 in FIG. 1 are omitted, and all the machine tools MC1, MC2, MC3 and MC4 complete the machining in one step. Further, circles, hexagons, triangles and quadrangles in FIG. 7 indicate workpieces, and changes in the shapes mean machining by the machine tools MC1, MC2, MC3, MC4.

First, the first step is to make all machine tools MC1, MC
2, MC3 and MC4 are all operated by push priority control. That is, when the workpiece 25 is loaded into the machine tool MC1, the machine tool MC1 sends the workpiece 19 to the machine tool MC2 and starts machining the workpiece 23. Workpiece 1
The machine tool MC2 into which 9 has been fed sends the work piece 13 to the machine tool MC3 to machine the work piece 11. The machine tool MC3 into which the work piece 13 is loaded is transferred to the machine tool MC4 and the work piece 7
Are sequentially sent to process the workpiece 5. The workpiece 1 of the finished machine tool MC4 into which the workpiece 7 is loaded is discharged, and the workpiece 5 is processed.

In the second step, when the workpiece 26 is loaded as in the first step, the workpieces 20, 14 and 8 are sequentially sent and the finished workpiece 2 is discharged. Next, it is assumed that the machine tool MC1 fails at the beginning of the third step. Then,
Since the machine tool MC2 is driven by the push control, since the work piece 21 is not loaded, the work piece 15 is not sent to the machine tool MC3 and the machine tool waits for loading the work piece and stops. Then, the machine tool MC3 is driven by the pull priority control because the machine tool MC2 is no longer loaded with the workpiece, the machine tool 9 is sent to the machine tool MC4, and the machine tool 13 in the machine tool MC3 is machined. . Machine tool M
C4 is driven by push priority control
Is driven normally, and the finished workpiece 3 is discharged.

In the fourth step, the machine tool MC3 does not receive the workpiece W15 from the machine tool MC2, but the workpiece 10 is sent to the machine tool MC4. At this time, machine tool MC
There is no unprocessed workpiece held in 3 so no machining is performed. However, the workpiece 14 is an unmachined workpiece, but as described above, the loader 28 of the machine tool 13 (MC3) always holds one machined workpiece and one unmachined workpiece. The workpiece 14 is not processed.

In the fifth step and the sixth step, similarly to the fourth step, the machine tool MC3 is transferred to the machine tool MC4 and the workpiece (the work piece 11 in the fifth step, the work piece 12 in the sixth step) is transferred to the machine tool MC4. send. When the machine tool MC1 is restored from the seventh step, the work flows by the normal push control. That is, the workpiece 21 is loaded into the machine tool MC2, the workpiece 15 is sent to the machine tool MC3, and the workpiece 18 is processed. The machine tool MC3 sends the workpiece 13 to the machine tool MC4, and processes the workpiece 14. . The machine tool MC4 ejects the finished product 7 and processes the work 11. Then, from the eighth step onward, the same operation as the seventh step is repeated to process and convey the workpiece.

As described above, in the machine tool of the present embodiment, when the machine tool in the line is operating normally, the machined workpiece from the previous process is input to the machine tool. Since it is driven by push priority control that processes and carries out the process, it is possible to send the workpiece without increasing the fluid inventory, and the machine tool stops due to a failure etc. If the machined workpiece of the above is not input, even if the machined workpiece is not input, the machined workpiece held in the machine tool is sent to the machine tool in the subsequent process, and the machine tool Since it is driven by the pull priority control for machining the unmachined work inside, it is possible to prevent the entire line from stopping and prevent the line operating rate from decreasing as much as possible.

Further, by providing the machine tool driven by the above-mentioned push and pull priority control to the machine tool having a long machining cycle time among the machine tools in the post-process of the machine tool which is frequently stopped due to the exchange of the cutting tool or the like, It is easy to recover unmachined and machined workpieces in the machine tool that decrease during pull priority control, and more than one machine tool driven by push and pull priority control is provided for the entire line to prevent the line operation rate from decreasing. Can be done effectively.

[0031]

As described above, at least one machine tool in the automatic production line of the present invention performs the first process when the detecting means detects that the machine tool in the line is normally driven. By means of the means, in synchronism with the timing at which the processed workpiece is sent from the machine tool in the previous process, the loading of the unprocessed workpiece held in the machine tool of the process is started, and the processed workpiece is post-processed. Since the workpieces are sent to the machine, the workpieces can be sent without generating a fluid inventory caused by the difference in the cycle time of each machine tool, and the detecting means can replace the cutting tool of the machine tool or cause a failure in the previous process. When it is detected that the machine tool has stopped, the second processing means irrespective of the timing at which the processed workpiece is sent from the previous step, the unprocessed workpiece held in the machine tool of the step is processed. Starts the loading of the workpiece,
Since the processed workpiece is sent to the machine tool in the subsequent process, it is possible to prevent the entire production line from being stopped, and it is possible to prevent the line operating rate from decreasing as much as possible.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an automatic production line showing an embodiment of the present invention.

FIG. 2 is a detailed view of the machine tool 13.

FIG. 3 is a flowchart showing an operation of push priority control.

FIG. 4 is a flowchart showing an operation of pull priority control.

FIG. 5 is a diagram modeling the operation of push priority control.

FIG. 6 is a diagram modeling the operation of pull priority control.

FIG. 7 is a diagram showing a production process.

[Explanation of symbols]

 11, 12, 13, 14 Machine tool 15, 17 Transfer device 27 Jig 28 Loader 30 Internal transfer device 40 Workpiece holding device

Claims (1)

[Claims] 1. An automatic production line in which a plurality of machine tools such as a processing machine for processing a work are arranged and a transfer device for transferring the work is arranged between the machine tools. Of at least one of the machine tools described above, a workpiece holding unit that holds at least one unprocessed workpiece that has not been subjected to the process and a treated workpiece that has completed the process, and Detecting means for detecting whether the machine tool is operating normally, and when the detecting means detects that the machine tool in the previous step is operating normally, processing from the machine tool in the previous step In synchronization with the timing at which the finished workpiece is sent, the loading of the unprocessed workpiece held by the workpiece holding means is started,
A first processing means for sending the processed workpiece held by the workpiece holding means to a machine tool in a subsequent step, and the detection means detecting that the machine tool in the preceding step is stopped. , Starting to carry in the unprocessed workpiece held by the workpiece holding means regardless of the timing at which the processed workpiece is sent from the machine tool in the previous step, and is held by the workpiece holding means. An automatic production line comprising a second processing means for sending the processed workpiece to a machine tool in a subsequent step.