JP3042272B2 - Work input instruction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work input instruction method, and more particularly to a work input instruction method for improving the production efficiency while maintaining the leveling of the work.

[0002]

2. Description of the Related Art In a production in a factory, for example, in a vehicle production line, vehicles having a plurality of specifications are produced on the same line. In recent years, with the diversification of consumer preferences, the types of vehicles (vehicle types, vehicle types) produced on the same production line have been further increased, and suitable production management has been implemented in order to realize so-called multi-product small-lot production. Cars of various specifications must be manufactured.

[0003] In order to improve the production efficiency by improving the equipment for realizing the high-mix low-volume production and improving the production control, it is necessary to supply each line of the work such as a vehicle in an optimal combination in the transfer order. For this reason, it is essential to equalize the time required for each operation and the component consumption interval.

For example, an automobile factory has a plurality of storages for temporarily storing vehicles transported between a painting line and an assembly line in an automobile manufacturing line. By these storages, the vehicles to be put into the assembly line are rearranged in accordance with predetermined work input restriction conditions, so that efficient assembly work can be performed in the assembly line. In Japanese Patent Publication No. 4-40233, two control items are listed: continuous / interval control for preventing the concentration of a specific vehicle type and ratio control for bringing the input ratio of each vehicle type as close as possible to the target ratio in order to achieve the production target number. Work input constraints. Then, priority is calculated from the ratio of each specific specification (for example, ABS, 4WD, etc.) in 100 out of the works that have been OK under the work input restriction condition and the work to be input (input work). ) Is disclosed.

[0005]

In the prior art, however, as shown in FIG. 7, the ratio of ABS work in Cases A and B in both cases of 100 is equal to 2 out of 100 as shown in FIG. From the viewpoint of conversion, Case A is not preferable because it is continuous. That is, in the extreme case as shown in Case A, there is no variation in the work, so that the procurement of parts to be mounted and the mounting work may be hindered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a purpose thereof is to provide a work input instruction method for instructing a work input so as to level the work to be input to an assembly line. Is to provide.

[0007]

In order to achieve the above object, a work input instruction method according to the present invention is provided between a predetermined production line and an assembly line, and is conveyed from the production line. A work is temporarily stored in one of a plurality of storages, and an optimum work is selected from input candidate works among the plurality of stored works based on predetermined work input restriction conditions, and a work to an assembly line is selected. In a work input instruction method for inputting a work, a step of obtaining an ideal number of work input intervals from the production ratio for each specification of the input candidate work, and for each input candidate work, a specification for each specification when the input candidate work is input. A step of obtaining the variation, a step of weighting the obtained variation of each specification, and a step of calculating the total sum of the weighted variation for each specification. And-up, the steps of the sum obtained is determined as the workpiece to be turned in the turned candidate works that minimizes the assembly line, characterized in that it has a to.

[0008]

In the work input instruction method according to the present invention having the above-described configuration, the ideal interval number of input workpieces is obtained from the production ratio for each specification of the input candidate work stored in the storage. From the ideal interval number, a variation for each specification when each input candidate work is input is obtained for each input candidate work, and further weighted to obtain a total sum. As a result, the input candidate work having the smallest sum is determined as the work to be input to the assembly line.

Therefore, the work to be input next is determined in consideration of the variation and the instruction to input the work is given, so that the work to be input can be leveled.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

First, an example of a line configuration for carrying out the work input method of the present invention will be described. In the present embodiment, a description will be given by taking as an example the rearrangement of the transport order between the painting line and the assembly line.

[0012] The conveyor 10
In order to rearrange the transfer order of the vehicle work 12 transferred by the conveyor 10 and the transfer order of the vehicle work 12 supplied to the assembly line which is a subsequent process by the conveyor 14, as shown in FIG. , 14 are provided with a plurality of storages 16 for temporarily storing the vehicle work 12 for each group. In the storage 16, four first-in first-out type line-type storages 16a, 16a, 1
6b, 16c and 16d are arranged in parallel. And, in order to store the vehicle work 12 conveyed by the conveyor 10 from the painting line in the corresponding storage 16, between the conveyor 10 and the storage 16,
Sorting conveyors 18 are arranged orthogonally. The vehicle work 12 conveyed by the conveyor 10 is once transferred onto a sorting conveyor 18 and conveyed to a corresponding entrance of the storage 16. And the vehicle work 12
Reaches the entrance of the corresponding storage 16, the sorting conveyor 18 stops and the vehicle work 12 is stored in the storage 16. In this manner, the vehicle work 12 stored in the storage 16 is transported forward and arranged in tandem with the vehicle work 12 already stored.

In order to load the vehicle work 12 stored in the storage 16 toward the conveyor 14 of the assembly line, a supply conveyor 20 is provided between the outlet side of each storage 16 and the conveyor 14 at right angles. Are located.
The vehicle work 12 satisfying a predetermined condition among the vehicle works 12 stored in each storage 16 is temporarily transferred from the outlet of the storage 16 to the supply conveyor 20 and transported to the front position of the conveyor 14. In this state, the supply conveyor 20 temporarily stops, and the vehicle work 12 is transferred onto the conveyor 14.

In this manner, by sequentially selecting the vehicle works 12 stored in the storage 16 and putting them into the conveyor 14, the vehicle works 12 can be serially conveyed to the assembly line in a desired order.

Which of the vehicle works 12 among the vehicle works 12 stored in the storage 16 is to be put into the assembly line is determined by selection based on work input restriction conditions. The work input constraint conditions are mainly work conditions (conditions that require the work itself such as vehicle type and specifications (with or without sunroof, air conditioner etc.)) and input conditions (interval specification of vehicle work with the same work condition) And transport conditions such as the number of possible continuous operations).

FIG. 2 is a flow chart of a process for extracting a candidate vehicle work to be inserted into the assembly line from the vehicle work 12 in the storage 16 and determining a suspended vehicle work from the extracted candidate vehicle work. First, the vehicle work 12 in the storage 16 is searched for a reserved vehicle condition such as a situation such as a missing part of an assembled part. (Step 101). Next, a search for the lifting standby condition is performed, and the number of colored machines, that is, the number of machines up to the step of actually assembling in the assembly line is equal to or larger than the set number, and the vehicle work 12 is arranged to the second head machine in the storage 16. If not, wait for lifting (step 10
2). Next, in the vehicle work 12 in the storage 16, the vehicle work 1 satisfying the work input constraint
2 is extracted. If there is no vehicle work 12 that satisfies the work input restriction condition, the input candidate vehicle work is extracted by deleting or relaxing the condition (step 103). That is, the work of the input candidate vehicle is extracted up to this step 103. Then, when a plurality of input candidate vehicle works are extracted, processing according to the distribution variation priority rule is performed (step 104).

A feature of the present embodiment is that by performing the distribution variation priority processing, it is possible to prevent the vehicle work 12 of a specific specification from being unbalancedly supplied to the assembly line.

The distribution variation priority processing will be described below.

FIG. 3 shows a main part of FIG. 1. In FIG.
It is shown that there are four units 2a, 12b, 12c, and 12d.
The vehicle works 12a, 12b, 12c, and 12d are ABS specifications, left-hand drive, and ABS specifications. In addition, the vehicle work 12e without specification, the vehicle work 12f of ABS specification,
A left-hand drive vehicle work 12g has already been loaded. The vehicle work 12 is transferred from the storage 16 via the supply conveyor 20 to the conveyor 14 of the assembly line.
In the following, a description will be given assuming that the storage 16 is simply input to the conveyor 14 from the storage 16.

As shown in FIG. 4, in the distribution variation priority process, first, the ideal interval number is determined from the production ratio for each specification (step 201). The production ratio is a ratio of vehicles of a specific specification included in the number to be produced.
As shown in FIG. 5, since the production ratio of the ABS specification is 33%, it is sufficient to produce one ABS specification vehicle for every three vehicles. In other words, 2
It is ideal to put a vehicle work that does not have the ABS specification into the assembly line by putting it into the assembly line. Therefore, the ideal interval number of the ABS specification is two. Similarly, the production ratio of the left-hand drive specification is 2
Since it is 5%, the ideal interval number is three. Although the ideal interval number may be obtained for all specifications, it is sufficient to obtain the ideal interval number only for specifications corresponding to the input candidate vehicle works 12a, 12b, 12c, and 12d.

Next, the input candidate vehicle works 12a, 12a
A variation is calculated for each specification of b, 12c, and 12d (step 202). The variation x _ji in the distribution of the i-th specification of the j-th input candidate vehicle work can be obtained by the following equation.

X _ji = ｛(0−b _j ) ² * c _j0 +... +
(K−b _j ) ² * c _jk + ・ ・ ・｝ / ｛(c _j0 + ・ ・ ・ +
c _jk +... -1) where k is the number of intervals, b _j is the number of ideal intervals, and c _jk is the number of vehicle works inserted at each interval.

The candidate vehicle work 12a shown in FIG.
The variation of each of the specifications 12b, 12c, and 12d is calculated as follows.

FIG. 6 is a graph showing the distribution of the vehicle work already put into the assembly line with respect to the number of intervals for each specification. FIG. 6A shows the ABS specification as the i = 1st specification. FIG. 6B shows the distribution regarding the left handle specification as the i = second specification.

[0025] When introducing j = otherwise specified specifications as the first vehicle work 12a, the variation x ₁₁ distributed on ABS specifications, so the ideal interval number _{b 1 = 2, x 11 =} {(1-2) 2 × 2 + (2-2) ² × 8 + (3-
2) ² × 6 + (4-2) ² × 3 + (5-2) ² × 4} /
{(2 + 8 + 6 + 3 + 4) -1} = 2.55. Further, the variation x ₁₂ distributed about the left-hand specifications, so the ideal interval number _{b 2 = 3, x 12 =} {(1-3) 2 × 1 + (2-3) 2 × 3 + (3-
3) ² × 4 + (4-3) ² × 2 + (6-3) ² × 1 +
(7-3) ² × 2｝ / ｛(1 + 3 + 4 + 2 + 1 + 2)-
1｝ = 4.17.

Next, the distribution variation of each specification is weighted by how much importance is placed on the disturbance of each specification (step 203), and the total sum of the distribution variation is calculated (step 204). When there are M specifications to be leveled and N input candidate vehicle works in the storage 16 exist, the variation in distribution when the j-th input candidate vehicle work in the storage 16 is input to the assembly line. The sum E _j is evaluated by the following equation.

E _j = w ₁ x _j1 + w ₂ x _j2 +... + W _{i
x ji + ··· + w M x} jM However, w _i is one of the weighting factor to emphasize how much disturbance for the i-th specification, x _ji is a value representing the variation of the distribution. In this embodiment, M = 2 and N =
4.

Therefore, in this embodiment, w ₁ = w ₂ = 1
When the sum E ₁ of the variation in the case of introducing the vehicle work 12a is _{E 1 = x 11 + x 12} = 2.55 + 4.17 = 6.72.

[0029] Next, when turning on the vehicle workpiece 12b of the left handle specifications as j = 2 th, variation x ₂₁ distributed on ABS specification is 2.55 similar to x _11. Here, paying attention to FIG. 3, when the vehicle work 12b is inserted, the number of intervals is 2 because the vehicle work 12g of the left-hand drive specification already exists on the assembly line. Accordingly, FIG. 6B shows the number of vehicle works 12 to be input.
Are added to obtain c ₂₂ = 4. Thus, the variation x ₂₂ distributed about the left-hand _{specifications, x 22 = {(1-3)} 2 × 1 + (2-3) 2 × 4 + (3-
3) ² × 4 + (4-3) ² × 2 + (6-3) ² × 1 +
(7-3) ² × 2｝ / ｛(1 + 4 + 4 + 2 + 1 + 2)-
1｝ = 3.92.

Therefore, assuming that w ₁ = w ₂ = 1, the total sum E ₂ of the variations when the vehicle work 12b is inserted is E ₂ = x ₂₁ + x ₂₂ = 2.55 + 3.92 = 6.47.

Further, when turning on the vehicle workpiece 12c of ABS specifications as j = 3 th, variation x ₃₁ distributed on ABS specification in the same manner as described above, FIG. 6 as the number of vehicles workpiece 12 to be turned on (a) X ₃₁ = 2.47 when considering that the hatched portion 61 is added. Also, x ₃₂ = x ₁₂ = 4.17.

Therefore, assuming that w ₁ = w ₂ = 1, the total sum E ₃ of variations when the vehicle work 12c is loaded is E ₃ = x ₃₁ + x ₃₂ = 2.47 + 4.17 = 6.64.

When the vehicle work 12d of the left-hand drive and ABS specifications is inserted with j = fourth, the variation x ₄₁ , x ₄₂ of the distribution related to each specification is represented by the hatched portion 61 as the number of vehicle works 12 to be input. 62 are added, and x ₄₁ = x ₃₁ = 2.47 and x ₄₂ = x ₂₂ = 3.92.

Therefore, assuming that w ₁ = w ₂ = 1, the total sum E ₄ of the variations when the vehicle work 12d is inserted is E ₄ = x ₄₁ + x ₄₂ = 2.47 + 3.92 = 6.39.

Here, since there is no other work candidate vehicle to be inserted (step 205), the sum of the work candidates to be inserted is compared (step 206). As described above, it can be seen that the value of E ₄ (= 6.39) is the smallest of the sum of the variations. Accordingly, the vehicle work 12d is selected as the next vehicle work to be input according to the distribution variation priority rule (step 207).

As described above, by considering the variation in the frequency distribution of the number of intervals for each specification, it is possible to prevent the vehicle work of a specific specification from being unbalancedly input.
In the case where there is only one input candidate vehicle work, the input candidate vehicle work is the input vehicle work.

As described above, the input vehicle work selected in the distribution variation priority processing is determined in step 105 in FIG.
It will proceed afterwards. Here, in step 105, a full lane priority process is performed. That is, the storage 16
Line type storages 16a, 16b, 16
c and 16d are classified as much as possible by vehicle type and specification, and stored in each line type storage by vehicle type and specification.
Here, for example, a full lane is provided in case a storage for a certain vehicle type is full. Therefore, in the processing up to step 104 in FIG. 2, when a plurality of vehicle works 12 arranged in the full lane and the non-full lane are selected as the input vehicle work, it is considered that the full lane becomes full. In order to prevent this, priority is given to the lane lane.

Step 106 is performed in the same manner as described above.
When a plurality of vehicle works 12 in the first and second columns are selected as input vehicle works, the first vehicle work is preferentially input. This is because, in order to insert the vehicle work 12 in the second row, it is troublesome to temporarily retreat the first vehicle work 12 to the evacuation lane. Step 107 is a process for storing a plurality of vehicle works 12
Is selected as the input vehicle work, a vehicle work having a long residence time is preferentially selected.

In the above embodiment, a vehicle work has been described as an example of a work, but the present invention is not limited to this and may be an arbitrary work.

[0040]

As described above, according to the work input instruction method of the present invention, a specific work can be prevented from being input unevenly by taking into account the variation in the frequency distribution of the number of intervals for each specification. Therefore, it is possible to improve the level of leveling of the work to be input.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration based on an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a work input instruction method based on an embodiment of the present invention.

FIG. 3 is a main part of FIG. 1 and is a diagram illustrating a distribution variation priority process in the present embodiment.

FIG. 4 is a flowchart illustrating a distribution variation priority process according to the embodiment.

FIG. 5 is a diagram illustrating a method for obtaining an ideal interval number for each specification.

FIG. 6 is a diagram showing a distribution of the number of input vehicle works with respect to the number of intervals in each specification.

FIG. 7 is a diagram showing an arrangement order of works put into an assembly line.

[Explanation of symbols]

 10 Conveyor 12 Vehicle Work 14 Conveyor 16 Storage 18 Conveyor for Sorting 20 Conveyor for Supply

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G05B 19/418 B23P 21/00 307 B23Q 41/08 B62D 65/00

Claims (1)

(57) [Claims] 1. A work, which is provided between a predetermined production line and an assembly line, and temporarily stores a work conveyed from the production line in one of a plurality of storages. In the work input instruction method of selecting the optimal work from the input candidate work based on the predetermined work input restriction conditions and instructing the work input to the assembly line, the ideal work input is determined from the production ratio for each specification of the input candidate work. A step of obtaining the number of intervals, a step of obtaining, for each input candidate work, a variation for each specification when the input candidate work is input, and a step of weighting the obtained variation for each specification, The step of calculating the sum of the variations for each specification, and the work to be put into the assembly line with the input candidate work that minimizes the obtained sum Work on instruction method characterized by comprising the steps of determining, the.