Component transfer plan creation method

Abstract

The present invention provides a component transfer plan creation method capable of creating a transfer plan in a short time. The component transfer plan creation method has a transfer plan creation process. In this process, at least a part of multiple workplaces (2a to 2c), for workplaces where the number is set to be less than the maximum number of component boxes that can be stored and is 2 or more, the target storage number of the component boxes (5) is set as the target storage number. The time range from when the storage number of the component boxes (5) in the workplace becomes lower than the target storage number to before the components in the workplace cannot be assembled is set as the supplyable range (7). In such a way that the transfer cart (4) traveling along the transfer path (3) supplies the component boxes (5) to the workplace within the supplyable range (7) and the number of the component boxes (5) stored in the workplace becomes below the target storage number, the departure interval of the transfer cart and the component boxes (5) loaded on the transfer cart are set.

Description

Technical Field

[0001] The present invention relates to a component transfer plan creation method for creating a transfer plan for components to be transferred to a production line. Background Art

[0002] Conventionally, in many cases, components are collectively transferred to a storage space near the work area of the production line in advance to improve the distribution efficiency. However, operators on the production line (hereinafter referred to as production line operators) perform many operations other than manufacturing operations such as searching for required components from a large number of transferred component containers, replacing used containers with containers containing required components, etc., and the operation efficiency deteriorates. Therefore, if precise transfer is performed little by little so that the actions of the production line operators are minimized to the necessary component storage amount, the transfer frequency increases, and the operation efficiency of the operators performing the distribution (hereinafter referred to as distribution operators) deteriorates, and an increase in the number of distribution operators is required.

[0003] Regarding the above-mentioned contradictory problems, a component transfer plan creation method for automatically creating an optimal component supply state of a production line based on, for example, a genetic algorithm is known (for example, see Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2009-163511 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, to optimize the efficiency of production line operators and distribution operators, a huge amount of calculation is required. In cases where production, etc., in which the content produced on the production line changes in a short period, and transfer plans need to be created frequently, it is desired to be able to create transfer plans quickly.

[0009] In view of the above problems, an object of the present invention is to provide a component transfer plan creation method that can improve the operation efficiency of production line operators and transfer operators and can create a transfer plan in a short time.

[0010] Means for Solving the Problems

[0011] [1] In order to achieve the above-mentioned object, a component transport plan creation method of the present invention creates a transport plan for supplying component boxes (e.g., component boxes 5 of the embodiment, hereinafter the same) to a production line (e.g., production line 1 of the embodiment, hereinafter the same) having a plurality of work places (e.g., work places 2a to 2c of the embodiment, hereinafter the same) by means of a transport vehicle (e.g., transport vehicle 4 of the embodiment, hereinafter the same) traveling along a transport path (e.g., transport path 3 of the embodiment, hereinafter the same). The component transport plan creation method is characterized in that:

[0012] A transport plan creation process (e.g., the transport plan creation process of the embodiment. The same below) is provided, in which, in at least a part of the plurality ...

[0013] The departure interval of the transport trolley and the component boxes loaded on the transport trolley are set in such a manner that the component boxes are supplied to the work site within the supplyable range using the transport trolley traveling along the transport path and the number of component boxes stored at the work site becomes less than the target storage number.

[0014] According to the present invention, since the number of component boxes stored in the workplace can be reduced, the man-hours of the production line operators are reduced and the work efficiency of the production line operators is improved. In addition, by setting the supply range of components for each workplace, the delivery time can have a range, so the number of transport carts traveling along the transport path can be reduced, the work efficiency of the delivery operators is improved, and the component transport plan of the production line can be created in a short time.

[0015] [2] In addition, in the present invention, the transport plan creation process preferably includes the following processes: a temporary planning process (for example, the temporary planning process of the implementation mode. The same below). In this process, a temporary transport plan is set in which the departure interval of the transport trolley is set to a constant interval and the unloading number of the component boxes at the work site is kept constant; and an adjustment process (for example, the adjustment process of the implementation mode. The same below). In this process, based on the temporary transport plan created in the temporary planning process, the component box expected to be supplied outside the supply range is moved to a transport trolley within a specified time before or after the transport trolley scheduled to transport the component box, and the arrival time of the transport trolley is adjusted.

[0016] According to the present invention, since a temporary conveyance plan is created under the conditions that the departure time intervals of the conveyance carts are constant and the number of component boxes unloaded at each work site is also constant, a temporary conveyance plan can be created in a short time. Further, in the adjustment process, it is only necessary to calculate the part that exceeds the supply range based on the temporary conveyance plan obtained in the temporary plan process, and thus a component conveyance plan for the production line can be created in a short time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. is an explanatory view of a production line schematically showing a method for creating a component conveyance plan according to an embodiment of the applied invention.

[0018] Figure 2 FIG. is an explanatory view schematically showing a work site according to the present embodiment.

[0019] Figure 3 FIG. is an explanatory view schematically showing a conveyance plan for a first component box according to the present embodiment.

[0020] Figure 4 FIG. is an explanatory view schematically showing a conveyance plan for a second component box according to the present embodiment.

[0021] Figure 5 FIG. is an explanatory view schematically showing a conveyance plan for a second component box according to a reference example.

[0022] Figure 6 FIG. is a flowchart schematically showing a processing procedure of a control device according to the present embodiment.

[0023] Figure 7 FIG. is an explanatory view schematically showing a temporary conveyance plan obtained in the temporary plan process according to the present embodiment.

[0024] Figure 8 FIG. is an explanatory view schematically showing a conveyance plan obtained in the adjustment process according to the present embodiment.

[0025] DESCRIPTION OF REFERENCE NUMERALS

[0026] 1 Production line

[0027] 2a First work site

[0028] 2b Second work site

[0029] 2c Third work site

[0030] 3 Conveyance path

[0031] 4 Conveyance cart

[0032] 5 Component box

[0033] 5a First component box

[0034] 5b Second component box

[0035] 6 Production line operator

[0036] 7 Supply range

[0037] V Automobile Detailed implementation manner

[0038] The method for creating a component transfer plan in the implementation manner of the invention will be described with reference to the accompanying drawings.

[0039] Figure 1 FIG. is a schematic diagram showing the production line 1 of the automobile V to which the method for creating a component transfer plan of the present embodiment is applied. On the left and right sides of the production line 1, a plurality of workplaces 2a, 2b, and 2c from the first to the third are provided. In an actual production line, more workplaces are set, but for the sake of convenience of explanation, the number of workplaces is reduced to 3 for description.

[0040] Around the production line 1, a transfer path 3 is provided in a manner surrounding the production line 1. The transfer path 3 allows a plurality of transfer carts 4 to pass through. In order to suppress the amount of computation when creating a transfer plan, one-way traffic is set and overtaking is prohibited when creating the transfer plan. The transfer cart 4 supplies the assembly component boxes 5 of the automobile V to each workplace 2a, 2b, and 2c.

[0041] In the present embodiment, the component box 5 is described in the case of including two types, namely, the first component box 5a and the second component box 5b. Actually, there are more than three types of component boxes, but for the sake of convenience of explanation, two types of component boxes 5 are described. The first component box 5a contains 25 components in one box, and the second component box 5b contains 10 components in one box.

[0042] Figure 2 FIG. is an enlarged and schematic diagram showing the workplaces 2a to 2c. As Figure 2 shown, the first component box 5a can be placed at most 3 in one workplace 2a to 2c. In addition, the second component box 5b can be placed at most 5 in one workplace 2a to 2c. However, in the actual workplace, there are various component boxes, and the production line operator 6 needs to find the component box containing the components to be used from various component boxes. Therefore, considering the work efficiency of the production line operator 6, the fewer the number of component boxes stored in the workplaces 2a to 2c, the better.

[0043] Therefore, a conveyance plan is created such that there are at most two first component boxes 5a in the first workplaces 2a and the second workplaces 2b to which the first component boxes 5a are to be conveyed, and a conveyance plan is created such that there are at most three second component boxes 5b in the third workplace 2c to which the second component boxes 5b are to be conveyed. In the present embodiment, in the first workplaces 2a and the second workplaces 2b, the target storage number of the first component boxes 5a is at most two, and in the third workplace 2c, the target storage number of the second component boxes 5b is at most three.

[0044] Figure 3 It is a diagram that simplifies and shows the conveyance plan of the first component boxes 5a in the first workplaces 2a and the second workplaces 2b. Figure 3 The broken line of Figure 3 shows the conveyance plan of the conveyance cart 4 with the horizontal axis being time and the vertical axis being the moving distance of the conveyance cart 4. The part extending in the left-right direction in the center of the broken line is the time when the component box 5 is unloaded at the first workplace 2a or the second workplace 2b, showing the case where the conveyance cart 4 does not move.

[0045] In the first workplaces 2a and the second workplaces 2b, the period from when the first component box 5a becomes one to when the first component box 5a is used up is set as the supplyable range 7 in which one first component box 5a can be conveyed to the first workplaces 2a and the second workplaces 2b, and a conveyance plan is created such that the conveyance cart 4 can convey the first component box 5a to the first workplaces 2a and the second workplaces 2b within this supplyable range 7.

[0046] In this way, by creating a conveyance plan such that the maximum number is two, which is less than three, the maximum number of the first component boxes 5a stored in the first workplaces 2a and the second workplaces 2b, it is possible to reduce the trouble of the production line workers 6 in the first workplaces 2a and the second workplaces 2b to search for components and perform operations efficiently.

[0047] In addition, by setting the maximum storage number of the first component boxes 5a in the first workplaces 2a and the second workplaces 2b to two instead of the minimum number of one, it is not necessary to frequently transport the conveyance cart 4 to the first workplaces 2a and the second workplaces 2b, and it is sufficient to convey one to two first component boxes 5a to the first workplaces 2a and the second workplaces 2b before the two first component boxes 5a are used up, and it is also possible to avoid a reduction in conveyance efficiency due to the suppression of the storage number.

[0048] Figure 4 It is a diagram that simplifies and shows the conveyance plan of the second component boxes 5b to the third workplace 2c. Figure 4The broken line shows the conveyance plan of the conveyance cart 4 with the horizontal axis representing time and the vertical axis representing the moving distance of the conveyance cart 4. The part extending in the left - right direction in the center of the broken line represents the time for unloading the parts box 5 at the third work place 2c, indicating the situation where the conveyance cart 4 does not move.

[0049] At the third work place 2c, the period from when the number of the second parts boxes 5b becomes 2 to when the second parts box 5b is used up is set as the supply - able range 7 in which 2 second parts boxes 5b can be conveyed to the third work place 2c, and a conveyance plan is created in such a way that the conveyance cart 4 can be used to convey the second parts box 5b to the third work place 2c within this supply - able range 7.

[0050] By creating the conveyance plan in such a way that the maximum number is 3, which is less than the maximum number of 5 of the second parts boxes 5b stored at the third work place 2c, the trouble for the production line operator 6 at the third work place 2c to search for parts can be reduced and the operation can be carried out efficiently. In addition, from Figure 4 It can also be seen that, as a characteristic of the case of the second parts box 5b, the adjacent supply - able ranges 7 have overlapping parts with each other.

[0051] As a reference example, Figure 5 A conveyance plan is shown in the case where, at the third work place 2c in the same way as at the first work place 2a and the second work place 2b, the number of the second parts boxes 5b is set to a maximum of 2 and the second parts boxes 5b are to be supplied one by one.

[0052] Since one second parts box 5b contains 10 parts, the consumption time of one box is short. From Figure 5 the reference example, it can be seen that the conveyance cart 4 must frequently be driven to the third work place 2c, and the conveyance efficiency is significantly reduced.

[0053] In the present embodiment, taking the parts box like the first parts box 5a that contains 25 parts per box as a threshold, for parts boxes containing more than 25 parts, as Figure 3 shown, a conveyance plan is created with the maximum storage number being 2 boxes. In the case of a parts box containing less than 25 parts per box, as Figure 4 shown, a conveyance plan is created with the maximum storage number being 3 boxes. This threshold is set based on the average value of the time until the parts in one parts box are used up and the desired departure time interval of the conveyance cart 4.

[0054] Figure 6A flowchart showing the creation of a transfer plan according to this embodiment. The transfer plan is created using a control device. The control device is an electronic unit composed of a CPU, a memory, etc., and by the CPU executing a program for creating a component transfer plan held in the memory, it functions to search for an approximate solution that generally satisfies the set conditions.

[0055] As Figure 6 shown, first, in STEP1, various information such as the number of components loaded in one component box 5, the size of the component box 5, the locations of the first to third workplaces 2a to 2c, assembled components, etc. are input, as well as specified information such as the distances between the first to third workplaces 2a to 2c, the total amount of the component delivery plan based on the daily production plan, the upper limit of the delivery load of the transfer cart for one-time transportation, the average number of component boxes unloaded at each workplace each time, and the average departure time calculated based on the target number of delivery workers.

[0056] Next, enter STEP2, and use an approximation algorithm to generate a temporary transfer plan that keeps the departure time interval of the transfer cart 4 constant and the unloading amount of the component boxes at each workplace 2a to 2c constant (that is, at the first workplace 2a and the second workplace 2b, the first component box 5a is 1, and at the third workplace 2c, the second component box 5b is 2). Figure 7 is a diagram arbitrarily showing the generated temporary transfer plan. It can be seen that there is a problem that the unloading of the component box 5a of the transfer cart 4 shown by the broken line in the center to the second workplace 2b cannot be completed within the supply range 7.

[0057] Next, enter STEP3, and the control device uses an approximation algorithm to optimize the part where the arrival time exceeds the supply range 7, so that all component boxes 5 fall within the supply range 7 by reloading onto other transfer carts 4 within the specified time range. Figure 8 shows the optimized state in STEP3. The optimization is achieved by having the previous transfer cart 4 carry out the work of transporting the first component box 5a by the central transfer cart 4 to the first workplace 2a, and advancing the arrival time at the second workplace 2b corresponding to the time of unloading the first component box 5a at the first workplace 2a. In this case, the optimization is achieved without changing the departure time of the central transfer cart, but it can also be optimized by advancing the departure time of the central transfer cart to advance the arrival time at the workplace 2b.

[0058] In addition, when all component boxes 5 do not fall within the supply range 7 or the calculation time in STEP3 is too long when using the above approximation algorithm, the number of transfer carts 4 is increased near the exceeding part and returned to STEP2, and the approximation algorithm in STEP3 is used to recalculate and optimize so that all component boxes 5 fall within the supply range 7.

[0059] In this way, by generating a temporary transfer plan in STEP2 that makes the departure times at constant intervals and the unloading amounts of the parts bins at each work site 2a to 2c constant, it is possible to significantly shorten the complex calculation processing time compared to the case of obtaining the optimal solution like in STEP3 at the beginning. In the present embodiment, STEP2 corresponds to the temporary plan process, STEP3 corresponds to the adjustment process, and STEP2 and 3 correspond to the transfer plan creation process.

[0060] Then, proceed to STEP4 to output charts, loading instruction lists for each transfer cart 4, etc., so that the transfer of the transfer cart 4 can be carried out according to the plan.

[0061] It should be noted that in the present embodiment, the case of creating a transfer plan in such a way that the number of parts bins 5 stored in all of the first to third work sites 2a to 2c is less than the maximum number of parts bins that can be physically placed at that work site has been described. However, it is also possible to create a transfer plan in such a way that the number of parts bins 5 stored is less than the maximum number of parts bins that can be physically placed at that work site only in a part of the multiple work sites. Thereby, the effect of obtaining the optimal solution of the calculation process of the transfer plan in a short time by reducing the number of parts bins stored in the present invention can be obtained.

[0062] In addition, in at least a part of the multiple work sites, the target storage number of the parts bins in the work sites where the number is set to be less than the maximum number of parts bins that can be stored and is two or more can be set as the target storage number.

[0063] In addition, the supply range of the invention can be set to the time range from when the number of parts bins stored at the work site becomes lower than the target storage number to before the parts at the work site cannot be assembled.

[0064] In addition, in the present embodiment, optimization is performed in STEP3 so that all the parts bins 5 fall within the supply range 7. However, when the excess part is small enough after the adjustment process in STEP3, it is also possible to cope with it by separately transferring the excess part without recalculation, thereby enabling the creation of a parts transfer plan for the production line in a short time.

Claims

1. A method for creating a component transport plan, the method creating a transport plan for supplying component boxes to a production line having a plurality of work sites by means of a transport vehicle traveling along a transport path, the method being characterized in that: The method comprises a transport plan creation step in which, in at least a part of the plurality of work sites, a target number of parts boxes to be stored in the work sites is set to a number less than the maximum number of parts boxes that can be stored and equal to or more than two as a target number of parts boxes to be stored, The supply range is defined as a time range from when the number of component boxes stored in at least one of the work sites becomes lower than the target storage number to when the components in at least one of the work sites cannot be assembled. The departure interval of the transport trolley and the component boxes loaded on the transport trolley are set in such a manner that the component boxes are supplied to the work site within the supplyable range by the transport trolley traveling along the transport path and the number of component boxes stored in at least a part of the work site becomes less than the target storage number.

2. The method for creating a component transport plan according to claim 1, wherein: The transport plan creation process includes the following steps: a temporary planning step of setting a temporary transport plan in which the departure interval of the transport vehicle is set to a constant interval and the number of component boxes unloaded at the work site is constant; as well as An adjustment process, in which, based on the temporary transport plan created in the temporary planning process, the component box expected to be supplied outside the supply range is moved to a transport trolley within a specified time before or after the transport trolley scheduled to transport the component box, and the arrival time of the transport trolley is adjusted.

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