JPH0671693B2 - Processing scheduling device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a machining scheduling device for machining scheduling of a plurality of machining machines. In particular, the present invention relates to a machining scheduling device for machining the same number of workpieces of a plurality of types with an FMS that operates a plurality of machine tools of the same specifications.

[Prior Art] Various methods are known for operating a so-called FMS, which is a system for efficiently operating a plurality of machine tools such as a lathe and a machining center without taking a break. Since the work pallets for transporting works to these machine tools have a constant size, a plurality of works are attached to the same pallet in the case of small works. Further, in the case of a large work, one piece is attached, or in the case of a deformed work, a small work and a large work are combined and attached.

There is a method of managing the number of processed pieces by a human, but it is complicated and many mistakes cannot be managed. On the other hand, a method is also known in which a central computer always instructs each machine tool to input a workpiece and manages the schedule.

[Problems to be Solved by the Invention] However, the method of managing by the command of the central computer is
Since it is necessary to constantly grasp and control the machining time and the number of machining of each workpiece, it is necessary to perform complicated time management, and a huge program for production scheduling is required for that purpose.

An object of the present invention is to provide an optimum machining schedule device with a relatively simple technical idea.

It is still another object of the present invention to provide a machining schedule device that equalizes the number of finished workpieces even if the number of pallets attached differs.

Still another object of the present invention is to obtain a least common multiple of the number of works to be mounted on a pallet, and control machining scheduling so that the number of works to be mounted / per pallet × the number of machining pallets = the number of machining is constant for each work in a machining cycle. To provide a device.

[Means for Solving Problems] The present invention adopts the following means in order to solve the problems.

A plurality of numerically controlled machine tools having the same machining function, a shelf or a workpiece setup device installed near the numerically controlled machine tool for storing a pallet on which a workpiece is placed, and the shelf or the workpiece setup device In a production facility having a transfer device that moves to and from the numerically controlled machine tool to transfer the pallets, and a central control device having software for controlling these pallets installed, the pallets attached to one pallet A pallet mounting storage device that stores the number A _M-1 (where M is an integer of 1 or more) for each type of work, and the type W of the work in the pallet mounting storage device.
L / A _M for the least common multiple calculating circuit for calculating the least common multiple L of the number of attachments A _M-1 for each _M-1 (where M is an integer of 1 or more) and L / A _M for each of the workpiece types W _M-1 A pallet delivery order storage device for delivering the pallet at a frequency of ₋₁ , and a machining schedule device for delivering the pallet for each type of the work according to the allocation frequency of the pallet delivery order storage device.

EXAMPLES Examples of the present invention will be described below with reference to the drawings. The diagram shown in FIG. 1 is a plan view of a flexible production system embodying the present invention. Four machining centers # 1 to # 4 are installed as machining devices. However, the number is not limited to this, and any number may be used as necessary. Each of the machining centers # 1 to # 4 is a common machining center having the same function. Therefore, the same machining can be performed by any of the machining centers # 1 to # 4.

A work W, which is an article to be processed, is stored in the shelf 1. One or more works W are stacked and fixed on the pallet. Although only the work W is stored in the shelf 1 of this embodiment, tools for a machining center or the like may be stored. The number of items loaded on the pallet depends on the type and size of the work. A track 2 is arranged along the shelf 1. On the track 2, the transfer robot 3 for pallet transfer runs on the track 2 by itself. The transfer robot 3
It is controlled by the transportation controller 4 for transportation.

A pallet changer 5 is arranged in each of the machining centers # 1 to # 4. The pallet changer 5
It receives a pallet from the transfer robot 3 or carries it out from the machining centers # 1 to # 4. Each NC control device 7 performs a movement operation under the same control as a normal NC control device, such as a tool movement locus of the machining centers # 1 to # 4 and a table movement.

Each NC control device 7 is placed under the control of the central control device 10. The central control unit 10 controls the transfer robot 3 via the transfer controller 4, and performs schedule management of the entire system and inventory management of works on the shelf 1 which will be described later.

FIG. 2 is a functional block diagram of the central controller 10. The CPU 9 is a central processing unit and controls the central control unit 10. Various memories, input / output devices, etc. are connected to the CPU 9 via the bus 11. In the upper left column of FIG. 2, the input / output device 12 having a keyboard, a display, etc. is the I / O device 1
It is connected to bus 11 via 3. The input / output device 12 is
It displays various memory contents, which will be described later, and a display for inputting / outputting calculation results and the like.

The pallet mounting storage device 14 stores the types W ₀ , W ₁ , W ₂ ...
Information such as the number of stocks and the number of processed pieces for each W _M-1 , and the number of each work W ₀ , W ₁ , W ₂ , ... W _M-1 that can be mounted on one pallet, A ₀ , A ₁ , It remembers A ₂ , ... A _M-1 . 1
It is desirable that the number of workpieces W to be mounted on the pallet be the same time for all the workpieces W, because the processing time per pallet is frustrating.

The shipping order memory 15 stores data for determining the order for taking out the pallets from the shelf 1 as described later. Work W type W ₀ , W ₁ , W ₂ , W ₃ ... W _M-1 M type and corresponding memory instruction number 1 to issue a pallet to each address from K to K + L-1 Or 0 is stored. 1 means that the corresponding pallet leaves the shelf 1. 0 means that there is no pallet issue. However, L is the least common multiple of the number of attachments A ₀ , A ₁ ... A _M-1 for attaching each work to the pallet.

For example, the work W ₀ of the shipping order memory 15 shown in FIG.
When the processing is started from 1, since 1 is stored in the W ₀ column of the Kth memory, the transfer robot 3 is instructed to transfer the pallet on which the work W ₀ is placed, and the pallet is taken out.
Next, the works W ₁ , W ₂ and W ₃ and the Kth memory are unloaded in the order of the work numbers. When the Kth row is completed, the K + 1th row is entered. The K + 1st row is the next K + 2nd row because there is no warehousing in each work W ₀ ... WM _-1 .

In the K + 2 row, ₁ is set in W ₁ , so the pallet of W ₁ is issued. In this way, the rows of the memories K, K + 1 ... Cart drive device 20 at the top of the right column
Are controlled by the controller 4. The controller 4
The traveling and positioning of the transfer robot 3 are controlled. The least common multiple calculating circuit 21 is the least common multiple L of the number of workpieces W ₁ , W ₂ , W _M-1 mounted per pallet A ₀ , A ₁ , A ₂ , A _M-1 .
Is a circuit for calculating.

Operation of Central Controller The flowchart of FIG. 3 (a) shows the write operation of the central controller 10 to the shipping order memory 15. However, there are M types of processed work W, W ₁ , W ₂ , W ₃ ... W _M-1, and the number of each processed work W attached to one pallet is A ₀ , A, respectively.
₁ , A ₂ , ... A _M-1 . In step, the least common multiple L of A ₀ , A ₁ , A ₂ , ... A _M-1 is calculated by the least common multiple calculating circuit 21. All the lines from address K to K + L-1 of the shipping order memory 15 are set to "0" (step). That is, the initial state is set.

The memory N is set to 0 in step. This meaning is work W ₀
Means N = 1 means work W ₁ and N = 2 means W ₂ . Next, in step S, the memory X is defined as K. In the step, 1 is written in the Nth bit of the address X. That is, since N is 0, 1 is written in the position of the Kth work W ₀ in the shipping order memory 15 which is the intersection of W ₀ and K. Set X = X + AN in step. However, AN is a variable and means A ₀ , A ₁ , A _N , ... A _M-1 .

Therefore, the first in the K-th row of the column W ₀ of the shipping order memory 15,
Sequentially write like 1 in the K + 3th row, and write 1 in every number of ANs in the column. For example, if A ₀ is 3, every 3 units are added to X. After all, the least common multiple / AN evenly in columns
This means that 1 of the number has been allocated. Work in steps
Determine X> K + L-1 which means the bottom column of the W ₀ column.

That is, it is determined whether or not the least common multiple has been reached. When the column W ₀ of W ₀ is completed, and N = N + 1 in step. Work W ₀ is called work W ₁ . N> M in steps
-1 is judged, and if Yes, it goes to the next step, and if NO, it returns to the step, that is, the above-mentioned operation is repeated for writing in the next column of W ₁ . Write all columns of work W _M-1 .

FIG. 3B is a program for compressing the data input in the above flowchart. Y = K + in steps
Define L-2. In the step, it is judged whether or not the address Y is all 0 bits. This is a judgment as to whether or not all the rows of the shipping order memory 15 are 0 bits. If all are 0, the contents from address Y + 1 to address K + L-1 are shifted one by one to the previous address (step). All 0 means that there is no issue, so all 0
To save memory.

The memory is set to Y = Y-1 in step. In step, Y <K is determined, and if all addresses are not completed, the process returns to step and the above operation is repeated to complete all addresses. It should be noted that this program saves memory and is not always necessary.

Flow of work machining order FIG. 4 shows a flow for executing the shipping order memory 15 created by the program. In step, it is determined whether the carrier vehicle is moving. At step, it is judged whether the machining center # 1 requests the pallet. If Yes, go to Step, Machining Center # 1
One of the works W ₀ , W ₁ ... W _M-1 of the work W in the memory A is serviced. The memory A is given as an initial value. If NO, go to step. In step, the same judgment as in step is performed. This judgment is performed up to the required number n of installed machining centers.

If none of the machining centers # 1 to # 4 has requested the pallet, the process returns to step and the same operation as described above is performed. In the step, the memory N is incremented by 1, and N = N +
Set to 1. However, N represents the type of work W,
For example, N = 0 means W ₀ , N = 1 means W ₁ , and N means WN. In step, it is judged whether the N bit of the address Z is 0 or not. That is, it is determined whether or not a bit N in a row of the delivery order memory 15 is 0. If Yes, the process proceeds to step N = N + 1, and in the shipping order memory 15, the horizontal line is read. Proceed to the next work W in the same row. For example
If the work is W ₀ , proceed to W ₁ . If NO, A = N in step.

Write the value of N to A memory. In step N> M-
1 is determined, and it is determined whether one row of the delivery order memory 15 is completed. If yes, go to step. NO
If so, go to step. Address Z in steps
It is determined whether all the bits of 0 are 0. In other words, it is whether or not the number of rows in the shipping order memory 15 has reached K + L-1. As described with reference to the flowchart in FIG. 3B, this is compressed when all the rows are 0, so that all 0s means the last row of the shipping order memory 15. If Yes, it is judged that the general schedule has been completed, and the process returns to Z = K and advances to the step.
If NO, go to step N = 0. Then go back to the step. That is, the stock order memory 15 is restarted from the beginning.

[Other Embodiments] The production system of the above-mentioned embodiment takes out the pallets stored in advance from the shelf 1. However, the pallet may not be stored on the shelf 1 but may be displayed on the display from the central control unit 10 so that the operator fixes the work W required for the pallet each time. Alternatively, the automatic setup device may automatically mount the necessary workpieces on the pallet. Although the above numerically controlled machine tool is a machining center, it is obvious that it can be applied to other machine tools such as a lathe.

[Effects of the Invention] As described above in detail, the processing scheduling apparatus of the present invention can easily determine the processing schedule by calculating and assigning the least common multiple of the number of pallets attached.

[Brief description of drawings]

1 is a plan view of the present system, FIG. 2 is the control device, FIGS. 3 (a) and 3 (b) are flow charts of the control device of FIG. 2, and FIG. 4 is a flow chart of the present system. 1 ... Shelf, # 1 to # 4 ... Machining center, 3 ... Transfer robot, 4 ... Transfer controller, 5 ... Changer, 10
...... Central control unit, 14 ...... Pallet mounting storage unit, 15 ……
Departure rank memory

Claims (1)

[Claims] 1. A plurality of numerically controlled machine tools having the same machining function, a shelf or a workpiece setup device installed in the vicinity of the numerically controlled machine tools for accommodating a pallet on which a workpiece is placed, and the shelf or said In a production facility having a transfer device that moves between a workpiece setup device and the numerically controlled machine tool to transfer the pallets, and a central control device having software for controlling these, one of the above The number of each of the above-mentioned workpieces that can be mounted on the pallet
A _M-1 (however, M is an integer of 1 or more) per a pallet mounting storage device for storing the type of said workpiece of said pallet attachment storage in the device W _M-1 (however, M is an integer of 1 or more) L / L for the least common multiple calculation circuit for calculating the least common multiple L of the number of attachments A _M-1 and L / L for each of the workpiece types W _M-1
A pallet delivery order storage device for delivering the pallets at a frequency of A _M-1 , and a processing schedule device for delivering the pallets for each type of the workpiece according to the allocation frequency of the pallet delivery order storage device.