JPS6130366A - Control of physical distribution - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a logistics control method, particularly to production progress management, in a logistics route that has many branches or joins between the initial stage and the final stage. The present invention relates to a merging control method that allows easy processing in subsequent steps. - [Prior art].

In various processing or drawing processes in the factory,
It is necessary to accurately manage in-process work in each process, and it is known that such logistics management has a large impact on production efficiency.

For example, in recent years in the automobile industry, a logistics control method known as the Campan method is useful for optimizing in-process inventory within a factory and simplifying its management.

- As is well known, the above-mentioned Kanpan method aims to reduce the in-process inventory in the factory by requesting the delivery of the necessary m products or parts from the post-production process to the pre-production process sequentially. It is extremely useful in Yamato production and in production processes where a large number of process routes are gradually integrated.

However, although this type of Kanpan method is useful for managing required parts in subsequent processes, it does not have more detailed logistics information, so it is difficult to manage products or parts that are still in progress (hereinafter referred to as "in-process work"). There was a problem in that no consideration was given to the order of supply.

In particular, in recent years, in multi-product mass production, work in progress has complex branching and merging of process paths.
Appropriate management control was not possible.

In particular, in the merging section where multiple processes are combined and sent to the subsequent process, the order of merging becomes a big issue in order to facilitate the equipment or work in the subsequent process, and the processing at this merging section allows for the flow of work in the subsequent process. Leveling is achieved, and the effect of such leveling can significantly improve the overall production efficiency even in high-mix mass production or high-mix low-volume production.

In general, in a multi-product mass production process, production progress management must be performed by combining different parts on a single processing or assembly line, and the combination of such different parts has changed in recent years due to consumer preferences. Due to diversification, there may be hundreds of types, and the process or degree of difficulty in each process varies depending on the type of processing or assembly, and as a result, a certain process in which combinations of the same type flow continuously If the flow stops at , or if the process proceeds with a different combination of ingredients each time,
Frequent procedure changes in specific processes result in similar flow stops or efficiency declines.
It has been desired to appropriately control the supply of work in progress to such a line at the junction.

For example, if we take an automobile assembly line as an example, there are cars that are easy to assemble and cars that are difficult to assemble in a particular assembly process, and by sending these at an appropriate frequency, leveling of the process is promoted and the overall production progresses. The balance is significantly improved, and specifically, the waiting time in each process is reduced, which often contributes to improved efficiency. These problems are noticeable on car body dovetail assembly lines, etc., and there is a big difference in assembly time between cars with many accessories and cars with few accessories. If they are fed continuously, this assembly process becomes saturated, and if these defects occur in each process, they will eventually cause problems that will stop the entire line.
Therefore, in the pre-merging section of this type of assembly process, it is necessary to supply τ while mixing it into automatic containers with different assembly difficulty marks at an appropriate frequency.

On the other hand, there are cases where performing the same type of work consecutively in other processes can significantly improve the efficiency of the process, and in such cases, it is necessary to continuously perform the same type of work in a lot, that is, in-process work that has the same type of post-process. In some cases, it may be necessary to do this, and it is also necessary to consider such lot formation at the confluence section.

For example, when painting heavy objects in the car assembly process, painting the same color can be done quickly by continuous work, but if the color of the car body changes, the paint must be replaced in the painting process each time. It is understood that the setup requires a great deal of effort and time, and paint is wasted during such setup, which significantly reduces the efficiency of the painting process.

Therefore, for such a painting process, it is preferable to continuously flow unfinished works of the same color.

Another example of the effective use of Rotsu R-i is that the process of drilling holes in engines, etc. is well known, and attaching and detaching the drill to a drilling machine requires a large amount of setup effort in such a process, and it is difficult to work with drills of the same diameter. Continuous flow of work in progress is preferred for improving efficiency.

Therefore, in a production line that handles a large number of parts, merging control that takes into consideration the leveling described above is required at each merging point. On-site work often relied on the intuition and skill of workers.

The above-mentioned processing at the merging section involves not only the merging of predetermined work-in-progress work along the normal route, but also the repair of defective products in each process. The quality of work in progress is partially checked, defective products are removed from the -0 line, and then returned to the original line through a special correction line. Disturbances occur in the flow of in-process workpieces that were previously targeted, but if the above-mentioned leveling is taken into consideration at the return junction to the line, it is possible to minimize the disturbances and perform optimal machining. The above-mentioned leveling is extremely useful even in such correction lines.

[Object of the Invention] The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to take into account leveling in the subsequent process at the confluence section, thereby significantly improving the overall production progress efficiency. The object of the present invention is to provide an improved logistics control method.

[Configuration of the Invention] In order to achieve the above object, the present invention comprises a plurality of Off
Logistics control force and method for serially transporting in-process workpieces supplied from a process to a single post-process at a merging point, and the processing conditions in the post-process for each in-process workpiece supplied to the merging point. is read from each work in progress, and the machining conditions of a predetermined number of work in progress serially transported immediately before the merging point and the machining conditions of the work in progress to be merged are evaluated in a predetermined manner to facilitate post-process processing. It is characterized by calculating whether or not to merge based on a fixed number calculation formula, and in the case of a merge section, the work in progress is sent to the subsequent process, and in the case of the merge section, the work in progress is made to wait in the front process. do.

"Example" Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the merging work of work in progress at the merging point using the physical distribution control force V according to the present invention.
The work in progress W carried by the conveyor 10 from the previous process is merged with other works at the merging point X and transferred to the subsequent process by the same conveyor 10.

On the other hand, from the in-process works W carried by the conveyor 12 from the second pre-process, only those necessary for the post-process of the conveyor 10 are selected, and the selected parts are transferred to the confluence section X.

The work-in-progress W can be handled as any product, but for example, in the embodiment, a car can be assumed as the work-in-progress W, and after passing through different pre-processes depending on the type of car, the work-in-progress W can be handled as any product, such as a painting process, a car body, etc. It is preferable to consider a junction for entering and exiting the assembly process.

A roller conveyor 14 is provided to send the work in progress W from the conveyor 12 to the merging point Wait while facing X.

Another button 20 is provided at this opposing position,
Desired workpieces W are pushed out from the standby position toward the merging point X and conveyed to the subsequent process by the conveyor 10.

Each in-process workpiece W sent from the two preceding processes toward the merging point Label reader 2 immediately before point
2 and 24 are installed, for example, a bar code reader or a detection camera, and these individual processing regulations are input into the merging control computer 26.

The merging control computer 26 calculates various types of merging control according to the present invention, which will be described later, and supplies a merging signal to the pusher 1-20, thereby controlling the workpiece W supplied to the merging point X through the second pre-process. to the downstream process of the conveyor 10, and also gives a wait signal to the gate 28 located just before the merging point , thereby controlling the desired merging effect at the merging point X.

A retention sensor 30 consisting of a limit switch or the like is installed in the conveyor conveyor 14, which notifies the merge control computer 26 that the number of workpieces W retained at the merge point X exceeds a predetermined value. I can do it.

The physical distribution control method according to the present invention will be explained below based on FIG.

In the present invention, it is also possible to determine whether or not the finished workpieces W of both conveyors 10 and 12 shown in FIG. It is also possible to determine whether or not to merge only one work in progress.

In the following description, from the second pre-process to the conveyor 12
An example of a control method will be described in which calculation is performed to determine whether or not workpieces in progress that are being fed to the merging point X only after being discarded from the roller conveyor 14 can be merged.

FIG. 2 shows a flowchart of the first embodiment of the physical distribution control method according to the present invention. When the merging control computer 26 starts, it first determines whether there is any work in progress to be merged at the merging point X; This can be known from data from the label reader 24, or from a workpiece sensor provided on the stopper 18.

If there is no work in progress to be merged at the merging point X, normal operation of the main line, that is, the line formed by the conveyor 10, is instructed and the process returns to the next control cycle.

On the other hand, if there is an in-process work at the merging point The machining conditions of a predetermined number of workpieces W, for example, five workpieces that have been serially transported to the next process immediately before the workpiece that is currently being judged, are also read.

The above-mentioned processing conditions are used in the example after Tf? When is a car body assembly process, it is expressed by the assembly difficulty level,
The processing conditions, that is, the work difficulty level, of the in-process rewarrior currently waiting at the confluence point X position l is X. Then, the difficulty levels of the previous five work-in-progress works that have already been sent out from the confluence point X toward the subsequent process are respectively Xl and X2. X3. X4
．． x5, these six processing conditions, or work difficulty levels, are detected, and in practice, such detection is performed by the label reader 2.
2.24, the label attached to each work W in progress is read and supplied as electrical information to the merging control combi coater 26.

When the machining conditions of the in-process workpieces to be merged and the machining tea f1 of a predetermined number of in-process workpieces that have already been serially conveyed to the subsequent process are read in the manner described above, the merging control computer 2□6 calculates these additions. It is determined whether merging is possible or not based on the conditions, and in the embodiment, this determination of whether merging is possible is performed by calculating an evaluation function based on the work difficulty level, or by calculating the work difficulty level and weighting using a coefficient. This evaluation function y is obtained from the processed tea 1'1Xo-.times.5 and weighting thereof based on the transport order.

Next, the merging control computer 26 compares the evaluation function y with reference values A and B, and determines whether or not merging is possible so that leveling can be performed in the subsequent process.

Roughly speaking, the determination of whether or not this merging is possible is performed if the evaluation function is smaller than A, that is, the lower reference value, then even if the work in progress is merged, sufficient work can be done in the subsequent process, so the merging is not performed. On the other hand, if the evaluation function is larger than this lower reference value A, processing in the subsequent process will be troublesome even if this work in progress is merged, and it will be kept on standby to wait for the next chance to merge. . However, if a judgment is made based only on the lower reference value A in this way, the number of workpieces in the standby state tends to increase too much, so in this embodiment, the upper reference value B is set separately from the reference value A If the evaluation function y is larger than this upper reference value B, then
This kind of merging is prevented because it makes the work in the process extremely difficult, but on the other hand, if there is an evaluation function between the two bases W and the values A and B, the amount of n seedlings at the merging point Depending on the situation, a decision is made whether to merge or wait. Therefore, when the evaluation function y is between the two reference values A and B, the presence or absence of retention is determined by the signal from the retention sensor 30, and when the number of retention exceeds a predetermined value, for example 5, the Merging is allowed even with evaluation functions that would make processing work a little more troublesome, and excessive stagnation is eliminated.

On the other hand, if the evaluation function y is between the two reference values A and B and there is no stagnation, or if the evaluation function y is larger than the upper reference value B, the control to prevent merging and flow only the normal main line is possible. It will be done.

Therefore, according to the present invention, merging control is performed in which the processing conditions of each work in progress are calculated together with the processing conditions of a plurality of work in progress serially conveyed before it, so that processing in the subsequent process is performed optimally. As a result, it is possible to obtain a well-balanced process progress effect that does not cause local work delays even in production progress cases that include branching and merging with complicated branches.

In principle, the above-mentioned calculation of the evaluation function is performed based on both the processing conditions in the subsequent process, especially the difficulty of the work, and the weight and coefficient depending on the sending order. Generally, if the machining interval in the subsequent process is sufficiently long, it is preferable to determine the evaluation function only based on the machining conditions, that is, the work difficulty level, without weighting. When the machining interval in the subsequent process is short, that is, when the workpieces in progress W are continuously supplied with little margin, it is preferable to weight them based on the supply order,
The weight of the work sent out first is set to be smaller.

An example of calculating the evaluation function will be explained briefly.

The basic evaluation function calculation in this embodiment is performed based on the following formula.

y-ax41)×1-IC×2” (1x3-1ex4”
[x5・X here. indicates the degree of difficulty in the subsequent process of rework, and Xl-・×5 indicates the processing of each of the five work-in-progress works serially conveyed to the subsequent process immediately before that. It shows 111 difficulty level,
Each difficulty level information is determined by the following items. Further, a-f are weighted coefficients, and when weighting is necessary, different values are given according to the transport order, or when weighting is not necessary, they are all set to "1".

Case 1 (Table 1) Processing conditions, that is, work difficulty: 10. 5. -5°-10 are applied to each x, and the weight is set to a one-digit coefficient, that is, a=1. b=1. c=0.5. d=0.33゜e
= 0.25, f = 0.25, the evaluation function y for various combinations is obtained as follows, and if the reference values for merging are allowed are lower reference value A = 9 and upper reference value B-15. , the confluence i1J or not is determined for each of the following 20 combinations.

Table 1 In case 1, the mark ○ indicates whether or not the merge is possible.

The Δ mark indicates the judgment based on the retention amount, and the X mark indicates the prevention of merging.

Case 2 (Table 2) This is a case where weighting is removed under the same conditions as Case 1, and the coefficient a = b = c = d = = e = f = 1, and the lower reference value A = 0 and the upper reference value B =20.

Case 3 (Table 3) The weighted coefficient is the same as in case 1, but the processing conditions, that is, the work difficulty level is 10. 8. 6. 4, and a lower reference value Δ=25 and an upper reference value B-28 are set.

Table 3 Case 4 (Table 4) This is a case where weighting is removed under the same difficulty level as Case 3, and lower reference value Δ-40 and upper reference value B=-48 are set.

Table 4 As described above, the desired cases are selected according to the vehicle type or article handled in each process, and Table 5 shows a list of processing conditions and weighting coefficients for each case, and Table 6 shows The evaluation results are summarized in a list.

Table 5 Force 6 As is clear from the above items, a desired evaluation difficulty is selected depending on the article to which the present invention is applied, and in reality, the workpiece is transported relatively slowly and each workpiece is If there is free time in each step, the weighting based on the transport order as in Case 2 or Case 4 removes the coefficient. On the other hand, when there is little time margin in the subsequent process, the weighting based on the transport order removes the coefficient. Merging control using this method is achieved.

FIG. 3 shows 43 other embodiments of an automobile pulling line to which the physical distribution control method according to the present invention is applied.
The same members as in FIG. 1 are given the same reference numerals, and their explanations will be omitted.

The characteristic feature of the second embodiment is that a worker M is placed at each merging point be.

Therefore, based on this display, operator M
2 to perform predetermined merging control using the aforementioned pusher 172Q5.

Product ffi Ko 2nd MA Ha+, 411JI 2h "t
#-Sat yy -tf+ The visiting display is turned to the right, and each display color indicates merging, judgment based on staying, and waiting.

FIG. 4 shows a control flowchart of the second embodiment,
It is almost the same as the chart in FIG. 2, but after the evaluation function determines whether or not to merge, the computer 26 simply displays the lamps on the display 40, and the operator M can change these display colors. The difference is that a predetermined operation is performed depending on the juncture, and it is possible to perform control that takes into account the operator's judgment for each confluence point X.

``Effects of the Invention'' As a twin, according to the present invention, ``the convergence of 11 m at the confluence point, which has not been done in the past, can be performed based on various processing conditions.
This makes it possible to easily perform or level out the processing at step I, and enables well-balanced process control without causing local delays at the back of the line. C-ha with processing including branching and merging
L+Copper I'/ Bow No ゝNol! To the transcription T jealousy 7 h7 Hori Rin φ course ``I can provide Xiang☆ho.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram showing a preferred first embodiment to which the physical distribution control method according to the present invention is applied, and Fig. 2 is a 70-button diagram showing the force control action of main parts in the first embodiment. 3 is a schematic configuration diagram of the second embodiment of the present invention, and FIG. 4 is a flow diagram of the main part of the second embodiment. 10... 1st conveyor 12... 2nd conveyor 26... Merging control-inverter X... Merging point W... Work in process x o-... Merging Addition of in-process work to [condition x 1~
×5... Machining condition y of f1 multiplication rework carried out serially just before merging judgment... Evaluation function. Figure 1 Figure 2 Figure 3

Claims (4)

[Claims] (1) In a logistics control method in which in-process workpieces supplied from multiple pre-processes are combined into a single post-process at a confluence point and transported serially, in the post-process for each in-process workpiece supplied to the confluence point. The machining conditions for each work in progress are read from each work in progress, and the machining conditions for a predetermined number of work in progress transported immediately before the merging point and the machining conditions for the work in progress to be merged are set to a predetermined value that facilitates post-process processing. It is characterized by calculating based on the evaluation function calculation formula to determine whether or not merging is possible, and if merging is possible, the in-process work is sent to the subsequent process, and if merging is not possible, the in-process work is made to wait in the previous process. Logistics control method. (2) A physical distribution control method according to claim (1), characterized in that the supply of work in progress at the merging point is automatically performed by an automatic supply device. (3) In the method described in claim (1), the determination of whether or not to merge at the merge point is made based on the display on the display,
A distribution control method characterized in that a worker operates a supply device based on this display. (4) In the method according to any one of claims (1) to (3), when the number of workpieces in progress exceeds a predetermined value in any preceding process, priority is given to the evaluation function result. A logistics control method characterized by supplying work in progress.