JP3159062B2 - How to change the production ratio of a production line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of changing a manufacturing ratio when a plurality of types of works are manufactured according to a predetermined manufacturing ratio, and more particularly to a method of changing a manufacturing ratio of a composite manufacturing line in which manufacturing lines are connected in the middle. About the method.

[0002]

2. Description of the Related Art Conventionally, assembling and manufacturing lines of automobiles and the like (for example, engine assembly lines and vehicle assembly lines, etc.)
A desired part (work) used in the assembly / manufacturing line is supplied at a predetermined position on the assembly / manufacturing line at an optimum timing. For this reason, a complex production line is formed throughout the assembly production line, where a component production line for producing and supplying the component is connected.
In addition, in the automobile production line, automobiles of different models and different equipment are generally assembled on the same assembly production line. Therefore, in each part manufacturing line, the work corresponding to the vehicle flowing through the assembly manufacturing line is manufactured in a mixed form. In other words, even workpieces having the same function (for example, engine blocks and cams) have different shapes, sizes, mounting hole positions, and the like for each vehicle type and equipment. A work is manufactured.

In general, a part manufacturing line mainly for machining a rough material by cutting or grinding a plurality of processing devices (M / C) 100a, 100b, 1 as shown in FIG.
And buffers 102a, 102b,... 102 for temporarily storing work before and after each type.
n. For example, in a parts manufacturing line for processing and manufacturing an engine block, two types of cast coarse material workpieces a0 are used.
, B0 are supplied to the coarse material buffer 102a. From the coarse material buffer 102a, casting coarse materials a0 and b are sequentially and selectively selected.
0 is selected and put into the M / C 100a, where the primary work pieces a1, a2, b1, etc. are processed. Thereafter, it is put into a predetermined storage position of the intermediate buffer 102b. Similarly, predetermined workpieces are sequentially taken out of the buffer in a similar manner, and processing of the secondary processing workpieces a11, a12, a21, a22, b12, etc., and processing of the tertiary processing workpiece are performed. Finally, the finished part works A, B, C,... G are manufactured and stored in the finished product buffer 102n.

At this time, the order and timing of loading the workpieces to be loaded into the respective M / Cs 100a... Are performed by a ratio setting panel 104 which collectively manages buffers before and after the M / Cs. That is, one ratio setting panel 104
The process of making the buffer before and after / C one block is performed independently. By performing management on a block-by-block basis, it is possible to mitigate the effect of fluctuations in the production amount due to processing defects and the like on subsequent steps, thereby achieving efficient production. Such a ratio setting panel 104 has a work-in-progress sequence table of about 200 cyclic workpieces prepared in advance based on a manufacturing plan, and manages various types of workpiece processing at a constant ratio. .

[0005] As described above, since each ratio setting panel 104 is independently managed, the remaining amount stored in the upstream buffer may be excessive or insufficient depending on the state of component consumption in the downstream process. Therefore, the ratio setting panel 104 constantly monitors the remaining storage amount of the downstream buffer, and corrects the contents of the in-process sequence table so that there is no excess or deficiency of processed parts with respect to the manufacturing plan in the downstream processing process. We go regularly.
Then, there is no excess or deficiency in the parts required in the assembly and production line into which the finally processed work is put.

When the production ratio is changed in the assembly production line, it is necessary to change the production ratio of the related parts production line. In other words, if the production ratio of the assembly production line does not match the production ratio of the parts production line,
Because there is excess or deficiency of work on the assembly production line,
The parts manufacturing line must manufacture the work in the parts manufacturing line so that the first work manufactured at the new manufacturing ratio just joins the first work of the assembly manufacturing line manufactured at the new manufacturing ratio. Specifically, the contents of the work-in-progress sequence table of each ratio setting panel 104 of the part production line are changed according to the new production ratio.

In general, the production lead time of a part production line is often much longer than the production lead time of an assembly production line, and in most cases, a part assembly line is connected in the middle of the assembly production line. . Therefore, it is necessary to change the production ratio of the parts production line retroactively with respect to the production ratio of the assembly production line. Also, on the parts manufacturing line, a ratio setting panel, which is independently managed on the parts manufacturing line, is also located at the downstream position so that the work manufactured at the new manufacturing ratio and the work manufactured at the old manufacturing ratio are not mixed. It was necessary to change the ratio setting panel located at the upstream position earlier than the one to be changed. In this case, the reference for the change timing of the production ratio of the component production line is the work start timing of the work managed by the ratio setting panel located at the beginning of the component production line. This work start timing is
The management operator of the ratio setting panel was arbitrarily determined based on experience and the like.

[0008]

However, as mentioned above, the joining timing of the head work of the parts manufacturing line manufactured at the new manufacturing ratio and the head work of the assembly manufacturing line manufactured at the new manufacturing ratio is determined. Since the in-process start timing of the component manufacturing line to be determined is determined by experience, there is a problem that it is difficult to safely match the merging timing and reliability is low. In other words, despite the fact that work is flowing at a new production ratio on the assembly production line,
In some cases, a workpiece manufactured at an old manufacturing ratio is supplied from a component manufacturing line, or vice versa. As a result, excessive stocks or missing parts of parts or assembly production lines have occurred.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is intended to reduce the production ratio of a composite production line in which production lines are connected halfway. It is an object of the present invention to provide a method of changing a production ratio of a production line, which can determine a start-of-process timing at which merging of works to be performed can be performed accurately.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a first production line for producing a plurality of types of first workpieces at a predetermined ratio, and a first production line for producing a plurality of types of first workpieces. The placed first work is put into a predetermined position,
And a second production line for producing a second work at a predetermined ratio using the first work, and a production ratio of the first work on the first production line according to a production ratio of the second work on the second production line. And a receiving time required for the second work to be conveyed from the in-process position of the second work to a predetermined position where the first work is loaded, and a second time in the first manufacturing line. The production ratio of the first work is changed retrospectively from the timing of the change in the production for changing the production ratio of the second work, based on the difference between the in-process time required from the in-process of one work to the introduction into the predetermined position. Starting the change of the work in process.

Here, the input time is, for example, the number of first works existing from the head of the first manufacturing line to the predetermined position where the first work is input to the second manufacturing line and the first work number.
The receiving time is calculated based on the manufacturing tact time of the work, and the number of the second works existing in the line from the head of the second manufacturing line to a predetermined position where the first work is input, and the manufacturing time of the second work, for example. It is calculated by the tact time. At this time, the input time is a correction in consideration of the number of works to be thinned out due to a defect of the work on the first manufacturing line obtained from past data or an incidental time generated until the first work is input to the second manufacturing line. It is preferable that the correction is performed in consideration of the time required for the operation.

[0012] According to this configuration, it is possible to determine the in-process start timing for changing the production ratio of the first work on the basis of the timing at which the first work and the second work merge. Can be managed. As a result, excess and deficiency of the first work with respect to the second production line can be completely prevented.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing a composite production line in which a plurality of first production lines are connected to a second production line. The first production line is, for example, a component production line 10a having a plurality of buffers as shown in FIG. , 10
At b, the engine block, cam, etc., which are the first work, are processed. Further, the second manufacturing line receives the first work manufactured at, for example, the component manufacturing lines 10a and 10b at an optimal position on the line, and assembles the first work with the second work 14 flowing on the line. The manufacturing line 12 performs In general, the production lead time of the parts production lines 10a and 10b using a plurality of machining centers is about 10 to 20 hours, and the production lead time of the assembly production line 12 is as long as about 4 to 5 hours, depending on the processing object. It is.

Hereinafter, the relationship between the component manufacturing line 10a and the assembly manufacturing line 12 will be described. In the above-described combined production line configuration, when the production ratio of the assembly production line 12 is changed due to a change in the production plan or the like, the relationship between the first work and the second work is determined by the first second work manufactured at the new production ratio. When the work 14 reaches the link position P with the component manufacturing line 10a, the first first work manufactured at the new manufacturing ratio corresponding to the new manufacturing ratio of the assembly manufacturing line 12 is connected to the link in the component manufacturing line 10a. It is desirable to reach the position P.

For this reason, in response to the change in the production ratio of the assembly production line 12, as shown in FIG.
/ C) Buffers 18a located before and after 16a to 16f
-18d is sequentially rewritten with the production ratio data (work-in-progress sequence table) of the ratio setting boards 20a-20c. By the way, for example, the two buffers 18a and 18b
In between, there are always a first work being processed by the M / C 16a, a first work just carried out of the buffer 18a, a first work just before being put into the buffer 18b, and the like. Similarly, between the buffer 18b and the buffer 18c,
The first work also exists between the buffer 18c and the buffer 18d. At this time, if the production ratio of each of the ratio setting boards 20a to 20c is changed collectively, the changed new production ratio and the first work actually processed by each M / C 16a. A contradiction occurs and the parts manufacturing line 10a
Among them, the first works manufactured at the new and old manufacturing ratios are mixed and the first work is excessive or insufficient. Therefore, the change to the new production ratio is performed sequentially after the elapse of a predetermined time from the top of the component production line 10a.

The time after the elapse of the predetermined time is a time from completion of processing of all the first workpieces existing between the two buffers to completion of charging of the first work to the downstream buffer. For example, if the manufacturing tact time of the component manufacturing line 10a is 15 minutes and there are 20 first workpieces between the buffers 18a and 18b, 15 × 20 = 300 minutes from the change of the new manufacturing ratio for the ratio setting board 20a ( After 5 hours) ratio setting panel 20
b is changed. Hereinafter, similarly, the buffers 18b and 18c
Between the number of the first works existing between the buffers 18b and 18c and the manufacturing tact time of the component manufacturing line 10a, based on the ratio setting panel disposed on the upstream side (right side in FIG. 2).
Change the ratio setting panel located on the downstream side. By performing the change with the time difference as described above, the production ratio of the first work can be smoothly switched even when the M / Cs 16a to 16f which are independently controlled are included. Each of these ratio setting panels 20a-20c is provided with a corresponding one of the ratio setting panels 20a-20.
The information is collectively managed by the ratio support computer 22 connected to the terminal c.

On the other hand, the production ratio of the second work flowing through the assembly production line 12 is managed by the assembled raw tube computer 24. In the assembled raw tube computer 24, data indicating the production order of the second work at least three to four days ahead as a daily production plan, that is, a work-in-progress sequence table is input.

Next, a procedure for changing the production ratio of the component production line 10a when the production ratio of the assembly production line 12 is changed will be described.

Now, with respect to the assembled live tube computer 24,
It is assumed that three days later, information that manufacturing is performed based on a manufacturing plan different from the current manufacturing plan is input. That is,
After three days, the work-in-progress sequence table is updated, and the production at the new production ratio is performed on the assembly production line 12. Information on the new production ratio of the assembly production line 12 is sequentially supplied from the assembled raw tube computer 24 to the ratio assist computer 22. The ratio assisting computer 22 allows the first second work manufactured at the new manufacturing ratio on the component manufacturing line 10a to be input to the first second work manufactured at the new manufacturing ratio on the assembly manufacturing line 12. The in-process timing of the first work is calculated based on the new production ratio. In the present embodiment, in order to easily grasp the in-process timing of the first work, the number of the first works based on the new production ratio before the introduction of the second work based on the new production ratio in the assembly production line is set. Calculate whether to start the process.

Assuming that the in-process start timing X (before) is based on the production ratio of the component production line 10a, it can be calculated by the following equation.

X = ｛(Ai + ai) × Bi + Ci + D
i) / E｝ -bi Here, in the above equation, Ai is, as shown in FIG. 1, the number of the first workpieces accumulated in the component manufacturing line 10 a and the material and processing failure in the component manufacturing line 10 a. This is the sum of the expected number of pieces that will be thinned out during processing. ai is the number of the first works accumulated in the section from the part manufacturing line 10 a to the assembly manufacturing line 12. Bi is
This is the manufacturing tact time of the component manufacturing line 10a. Ci
Is the average time spent in addition to the actual work required from the time when one first work is put into the component manufacturing line 10a to the time when the processing is completed and the product is unloaded from the component manufacturing line 10a. It is a work time, a tool replacement work time of the processing apparatus, an estimated time at which the line is stopped due to equipment failure, and the like. Di is the corresponding part production line 10a
Is the transfer time of information to the leading ratio setting panel 20a (see FIG. 2). E is the production tact time of the assembly production line 12. Further, bi is the number of the second works 14 in the assembly and production line 12 accumulated from the start of the assembly and production line 12 to the first work receiving position (link position P) from the component production line 10a.

Here, the first term on the right side of the above equation is the first work receiving position (link) of the assembly / manufacturing line 12 after the first work manufactured on the part manufacturing line 10a is put into the part manufacturing line 10a. It shows the number of second works that can be manufactured on the assembly manufacturing line 12 before reaching the position P).

Therefore, according to the above equation, the assembly production line 1
2 indicates how many units before the start of the production at the new production ratio should start the production of the first work on the component production line 10a at the new production ratio. Note that the information transferred by Di may require leveling processing for changing the processing order and the like for processing the first workpiece in order to improve processing efficiency. However, since this processing is separately performed by preliminary processing,
The time required for this processing is not added to the above equation.

Next, the ratio assisting computer 22 transfers the calculation result of the above equation to the assembled live tube computer 24. The in-process sequence table of the assembly production line 12 included in the assembling raw tube computer 24 has pointer information indicating a break when the production ratio is changed, that is, a break between days. Based on the result of the above equation, the assembling raw pipe computer 24 sets the number of vehicles before the break, if the parts manufacturing line 10a starts to work on the first work,
It is possible to grasp whether the first second work manufactured at the new production ratio and the first first work produced at the new production ratio exactly match.

When the production start (start of work) timing of the first work according to the new production ratio is reached, the assembling raw tube computer 24 moves to the ratio assist computer 22 and to the leading ratio setting panel 20a. Instruct the user to change the old production ratio to the new production ratio. As described above, the ratio assisting computer 22 controls each of the buffers 18a to 18a.
Since the number of the first works existing during the period 18d is controlled, the buffer 1 is changed after the ratio setting panel 20a is changed.
After confirming that all the first workpieces manufactured at the old manufacturing ratio between 8a and 18b have been put into the buffer 18b, the data of the ratio setting panel 20b is corrected to the new manufacturing ratio. Similarly, it is confirmed that all the first works manufactured at the old manufacturing ratio between the buffers 18b and 18c have been put into the buffer 18c, and the data of the ratio setting panel 20c is changed.

As described above, the receiving time required for the second work to be transported from the in-process position of the second work to the predetermined position at which the first work is loaded is determined based on the receiving time of the first work in the first manufacturing line. A process for changing the production ratio of the first work retroactively from the timing of the change of the production process for changing the production ratio of the second work, based on a difference from the introduction time required from the start of the process to the introduction into the predetermined position. By starting the hook change, it is possible to automatically determine the in-process start timing for changing the production ratio of the first work based on the timing at which the first work and the second work merge. Therefore, the merging of both can be managed accurately. As a result, excess and deficiency of the first work with respect to the second production line can be completely prevented.

FIG. 2 shows an example in which two M / Cs are arranged between four buffers, and the four buffers are managed by three ratio setting panels. However, the number of each device can be appropriately selected. When a plurality of component production lines are connected to the assembly production line, a ratio assist computer corresponding to each component production line is connected to the assembling raw tube computer 24, or each ratio of the plurality of component production lines is A single ratio support computer for collectively managing the setting panel is connected, and the same processing is performed on the component manufacturing line 10a.

In this embodiment, an example is shown in which the calculation of the in-process change timing of the first manufacturing line is represented by converting the number of workpieces, but may be directly represented by time.

Further, in this embodiment, a composite production line composed of a component production line and an assembly production line has been described. However, the type of work to be produced is not limited, and a composite production line of component production lines and an assembly production line of The same effect can be obtained even if the present invention is applied to the composite production line.

[0030]

According to the present invention, even when the production ratio is changed, the receiving time required for the second work to be transported from the in-process position of the second work to the predetermined position where the first work is loaded is reduced. Based on a difference between an in-process time required for the first work in the first production line and a time required for the first work to be fed to a predetermined position, retroactively from the timing of the in-process change for changing the production ratio of the second work. Since the in-process change for changing the production ratio of one work is started, the in-process start timing for changing the production ratio of the first work is automatically set based on the timing at which the first work and the second work merge. Since it can be determined, the merging of both can be managed accurately. As a result, excess and deficiency of the first work with respect to the second production line can be completely prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an arrangement state of a component manufacturing line and an assembly manufacturing line according to an embodiment of the present invention and the number of works in each manufacturing line.

FIG. 2 is an explanatory diagram illustrating a system that manages details of a component manufacturing line and a manufacturing ratio according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a configuration of a component manufacturing line that performs a plurality of types of component processing using a buffer.

[Explanation of symbols]

10a, 10b parts production line, 12 assembly production line, 14 second work, 16a to 16f, 100a to 1
00c Processing device (M / C), 18a to 18d, 100
a to 100n buffer, 20a to 20c, 104 ratio setting board, 22 ratio assisting computer, 24 assembling live tube computer.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) B23Q 37/00-41/08 G05B 19/418 B65D 65/00-65/18 G06F 17/60 B23P 21 / 00

Claims (1)

(57) [Claims] 1. A first manufacturing line for manufacturing a plurality of types of first works at a predetermined ratio, and a first work manufactured on the first manufacturing line are put into a predetermined position.
And a second production line for producing the second work at a predetermined ratio using the work, wherein the production ratio of the first work in the first production line is changed according to the production ratio of the second work in the second production line. In the manufacturing ratio changing method, an acceptance time required for the second work to be transported from a work-in-progress position of the second work to a predetermined position where the first work is input, and a time required for transferring the first work in the first manufacturing line. A process for changing the production ratio of the first work retroactively from the timing of the change of the production process for changing the production ratio of the second work, based on a difference from the introduction time required from the start of the process to the introduction into the predetermined position. A method for changing a production ratio, characterized by initiating a change.