JP4998189B2 - Hierarchy correction system for high-mix low-volume production lines - Google Patents

Description

  The present invention relates to an order correction system for a high-mix low-volume production line that can determine an optimal rank of workpieces to be transported to a downstream process in a high-mix low-volume production line.

  As a conventional technology, a painted body that is designed to level the workload in the next process by correcting the permutation in consideration of the interval of the work to be carried out to the next process as a candidate for the first work in the storage lane A storage permutation correction system is known (see, for example, Patent Document 1).

JP-A-6-144319

  However, in the conventional painted body storage permutation correction system, the work candidate to be carried out to the next process is only the first work in the storage lane, so the number of candidate work pieces is small and the optimum work candidate for carrying out cannot be determined. There is. In addition, if there is no work to be carried out at the specified interval in the candidate, the work cannot be carried out, which may lead to a line stop in the next process.

  The present invention has been made to solve the above-described problem. The work to be carried out is not limited to the top of the lane, and all works in the storage are set as candidates, and the carry-out priority of these works is set in advance. This system provides an order correction system for high-mix, low-volume production lines that rearranges workpieces in priority order and prevents line stoppage in the next process by unloading empty workpieces even if there is no candidate workpiece. is there.

In the order correction system of the high-mix low-volume production line according to the present invention, at the entrance before the work conveyed from the previous process is carried into the storage, reading means for reading the specification information such as the type and options of the work, It has a control programmable logic controller that stores the reading information of the reading means, stores the work conveyed from the previous process in the storage until it is decided to carry it out, decides the optimum order and carries it to the next process The control programmable logic controller sorts the work that can be carried out in the storage based on the reading information of the reading means in the order of preset priority, determines whether the next work can be carried out from the head work, and if possible was selected as the next carry-out work, in the case of carry-out not is if the relevant work can be carried out from the top of the priority judgment Ri then select the best work should be carried out by returning, when the next available carry-out work there is no one in the storage, and out of the sky work, the sky work is actually carried out the work Theoretically, one empty space is created in the rank by unloading the workpiece .

  According to the present invention, when there is no work to be carried out to the next process, the empty work is taken out, so that the stop of all the production lines in the next process can be prevented. Since the work flows continuously in the normal production line, if one stop is performed, the entire production line is stopped. Therefore, when there is no work to be carried out, the entire production line in the next process is stopped, but by this invention, when the target work does not exist, the empty work is carried out to prevent the production line from being stopped. The operating rate can be improved.

Embodiment 1.
FIG. 1 is a system configuration diagram showing the configuration of an order correction system for a high-mix low-volume production line according to Embodiment 1 of the present invention, and FIG. 2 shows the operation of the system for correcting a high-mix low-volume production line order according to Embodiment 1 of the present invention. It is a flowchart for demonstrating.

In the multi-product and small-quantity production line according to the present invention, the workpieces transferred from the previous process are rearranged in an optimal order and are transferred to the next process. In FIG. 1, first, a workpiece 1 a conveyed from the previous process is read by the reading device 3 with basic specification information such as the type and options of the workpiece before being carried into the storage 6. The read basic specification information is stored in a control programmable logic controller (hereinafter referred to as PLC) 4 and displayed on the inquiry terminal 5. Further, the conveyed work 1 a is sequentially stored in the storage 6. The work 1b stored in the storage 6 is stored in the storage 6 until it is decided to carry out. Then, the control PLC 4 selects a candidate work to be carried out from the work 1b in the storage 6 based on the information set in the inquiry terminal 5 so that the work in the next process is leveled. The work to be carried out can be selected from any work 1b in the storage 6. The selected unloading candidate workpiece is unloaded from the storage 6 and transferred to the next process. 1c has shown the workpiece | work carried out to the following process. Note that the workpieces to be carried out are all the workpieces 1b in the storage 6, and the carry-out priority of these workpieces 1b is set in advance by the inquiry terminal 5, and the workpieces 1b are rearranged in the priority order. Then, it is determined whether or not the next work can be carried out from the leading work, and if possible, it is determined as the next transport work. If unloading is not possible, selection is made by repeating the determination of whether the workpiece can be unloaded in order of priority. As described above, by determining whether or not the work can be carried out from the top of the priority order, even if the number of work pieces to be selected increases enormously, an optimum work to be carried out next can be selected.
If there is no work to be carried out next in the storage 6, the empty work 2 is carried out. Although the workpiece is not actually unloaded with the empty workpiece, the workpiece can be unloaded continuously by logically unloading the workpiece, and the stop of the production line due to the absence of the workpiece can be prevented in the next process. If there is no work in the storage 6 that can be carried out next, an empty work is taken out. This empty work does not actually carry out the work, but logically, one work is created in the rank by causing the work to be carried out. As a result, even when there is no work that can be carried out next time, the production can be continued without stopping the next process line.

Next, the flow of the unloading work determination process according to the first embodiment will be described with reference to FIG.
First, in step 10a, it is confirmed whether there is a setting instruction for forcibly unloading an empty workpiece. If there is a setting instruction for empty work unloading, the empty work is determined as the next unloading work in step 10f, and the process is terminated. Next, when there is no setting instruction for empty work carry-out in step S10a, the process proceeds to step 10b, and works that can be carried out in the storage 6 are rearranged in the preset priority order. By rearranging in priority order, even if the number of workpieces to be selected increases, other processes are not affected. Next, in step 10c, a work to be carried out next is determined in consideration of various settings from the work 1b in the storage 6. At this time, the workpiece specifications are confirmed in the order in which they are arranged in step 10b, and it is determined whether or not the workpiece can be subsequently removed. Next, it is determined in step 10d whether or not there is a selected work to be carried out. If there is, a carried-out work is determined in step 10e, and the process ends. If there is no selected work to be carried out in step S10d, the empty work 2 is determined as the next carry-out work in step 10f, and the process ends.

Embodiment 2.
FIG. 3 is a flowchart for explaining the operation of the order correction system for the high-mix low-volume production line according to Embodiment 2 of the present invention.
The flow of the unloading work determination process according to the second embodiment will be described with reference to FIG.
First, in step 10g, it is confirmed whether or not there is a setting for forced carry-out with time designation. If forced unloading is set in step S10g and the current time has reached the set time, the process proceeds to step S10e, where the set work is selected as a work to be unloaded next, and the process ends. If there is no setting for forced unloading in step S10g, the process proceeds to step 10a to check whether there is a setting instruction for forcibly unloading the empty workpiece. If there is a setting instruction for empty work unloading in step S10a, the empty work is determined as the next unloading work in step 10f, and the process ends. Next, when there is no setting instruction for empty work carry-out in step S10a, the process proceeds to step 10b, and works that can be carried out in the storage 6 are rearranged in the preset priority order. By rearranging in priority order, even if the number of workpieces to be selected increases, other processes are not affected. Next, in step 10c, a work to be carried out next is determined in consideration of various settings from the work 1b in the storage 6. At this time, the workpiece specifications are confirmed in the order in which they are arranged in step 10b, and it is determined whether or not the workpiece can be subsequently unloaded. Next, it is determined in step 10d whether or not there is a selected work to be carried out. If there is, a carried-out work is determined in step 10e, and the process ends. If there is no selected work to be carried out in step S10d, the empty work 2 is determined as the next carry-out work in step 10f, and the process ends. When a work is selected in step 10c, the work that is set to be forcibly carried out at time designation is not selected and is selected.

Embodiment 3.
FIG. 4 is a flowchart for explaining the operation of the order correction system for a high-mix low-volume production line according to Embodiment 3 of the present invention.
The flow of the unloading work determination process according to the third embodiment will be described with reference to FIG.
In the third embodiment, the constraint conditions for performing the workpiece selection process are divided into absolute constraints and normal constraints. The absolute restriction is a restriction that must be observed because it is a facility restriction in the next process. In addition, it is preferable that the normal constraints be kept according to various conditions. However, it is not always absolute, and rather than an empty workpiece, it is assumed that the workpiece can be released even if it is impossible.

In FIG. 4, first, in step 10a, it is confirmed whether or not there is a setting instruction for forcibly carrying out an empty workpiece. If there is a setting instruction for empty work unloading, the empty work is determined as the next unloading work in step 10f, and the process is terminated. Next, when there is no setting instruction for empty work carry-out in step S10a, the process proceeds to step 10b, and works that can be carried out in the storage 6 are rearranged in the preset priority order. By rearranging in priority order, even if the number of workpieces to be selected increases, other processes are not affected. Next, in step 10h, a determination based on normal constraints is performed. In step 10h, a determination based on the normal restriction is made, and it is determined in step 10d whether or not there is a selected work to be carried out. If there is, a carried-out work is determined in step 10e, and the process ends. Further, if there is no target workpiece in the normal constraints in steps S10h and S10d, a determination is made based on the absolute constraint in step S10i. In step 10h, a determination is made based on the absolute restriction, and it is determined in step 10j whether there is a selected work to be carried out. If there is, a carried-out work is determined in step 10e, and the process is terminated. If there is no corresponding work, the process proceeds to step 10f, the empty work 2 is determined as the next carry-out work, and the process ends.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram showing a configuration of an order correction system for a high-mix low-volume production line in Embodiment 1 of the present invention. It is a flowchart for demonstrating operation | movement of the order correction system of the high-mix low-volume production line in Embodiment 1 of this invention. It is a flowchart for demonstrating operation | movement of the order correction system of the high-mix low-volume production line in Embodiment 2 of this invention. It is a flowchart for demonstrating operation | movement of the order correction system of the high-mix low-volume production line in Embodiment 3 of this invention.

Explanation of symbols

1a Work 1b transported from previous process Work 1c in storage Work 2c transported to next process 2 Empty work 3 Reading device 4 Control PLC (Programmable Logic Control)
5 Inquiry terminal 6 Storage

Claims (3)

In a high-mix low-volume production line,
At the entrance before the work conveyed from the previous process is carried into the storage, the reading means for reading the specification information such as the type and option of the work, and the reading information of the reading means are stored, and the work is conveyed from the previous process. The work is stored in the storage until it is decided to carry out, and it is equipped with a controllable logic controller that decides the optimum order and carries it out to the next process,
The control programmable logic controller sorts the work that can be carried out in the storage based on the reading information of the reading means in a preset priority order, determines whether it can be carried out next from the head work, and if possible is selected as the next unloading work, when unloading impossible selects the next best work to be carried out by repeating the determination whether the corresponding work from the beginning of the priority can unloaded, next available unloading work when there is no one in the storage, and out of the sky work, the sky work, but does not actually carried out the work, by theory, to carry-out the work, to make room for one in the ranking A system for correcting the order of high-mix low-volume production lines.   When determining the optimal order, check whether there is a forced carry-out setting for the specified time.If there is a forced carry-out setting and the current time has reached the set time, the set work is 2. The system for correcting the rank of a high-mix low-volume production line according to claim 1, wherein a workpiece selected as a workpiece to be unloaded is selected and a workpiece forcibly unloaded at a specified time is excluded.   2. The order correcting system for a high-mix low-volume production line according to claim 1, wherein the system has a function of setting various kinds of restrictions by dividing into absolute restrictions and normal restrictions when determining the optimum order.

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