JP3724198B2 - How to determine the car body for PBS - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a painted body storage (PBS) positioned between the painting process and the assembling process of a vehicle assembly line, which one of a plurality of painted car bodies is present. The present invention relates to a method for determining whether to carry out the assembly process first.
[0002]
[Prior art]
In the assembly line of vehicles such as automobiles, PBS is generally provided between the painting process of painting the car body and the assembly process of assembling the vehicle by assembling parts (engine, transmission, etc.) to the painted car body. The adjustment of the order of loading the vehicle types in consideration of the organization of the parts assembly work (leveling of the work) and the inventory management of the parts to be assembled to the painted car body in the assembly process are performed.
[0003]
By the way, the PBS usually has a plurality of storage lanes in parallel, and the painted bodies that have entered from the PBS inlet are sequentially distributed to the storage lanes, and usually a plurality of painted bodies are present. Which of these pre-painted car bodies is to be transported to the assembly process first in the assembly process is an absolute condition that the assembly work cannot be performed unless it has been established. In addition to the following three sufficient conditions, (a) the ratio condition that the ratio of the number of assembled vehicles among multiple types of vehicles satisfies the set ratio (contains within a predetermined tolerance with respect to the set ratio), and (b) unloading Number of vehicles on the front side of the storage lane from the PBS outlet to return to the PBS inlet through the forwarding lane in order to pay out the vehicle body not at the head of the storage lane to the PBS outlet ) Is less than the specified number (and therefore can be carried out in a short time), and the offline due date condition that the offline (shipment from the factory) date is near, and these three sufficient Set each weight value matter, it was determined on the basis of the weighting among the absolute satisfy a plurality of vehicle ahead.
[0004]
[Problems to be solved by the invention]
However, in the above-mentioned conventional method, since the setting of the weight value of each of the above three sufficient conditions is fixed, the difference between the set number ratios of the number of assembled vehicles between the vehicle types is larger than a predetermined tolerance so that it is corrected. Even if you try to decide which car body you want to carry out first, you can't do it because it is hindered by other sufficient conditions. In addition, even if the number of vehicle bodies stored in the trim buffer between the PBS and the assembly (trim) process decreases and an attempt is made to carry out a vehicle body with a small number of forwarded vehicles, it cannot be prevented because of other sufficient conditions. There was inconvenience.
[0005]
[Means for solving the problems and their functions and effects]
An object of the present invention is to provide a method for determining a carry-out vehicle body that advantageously solves the above-described problem by appropriately changing the weight setting of each of the three sufficient conditions according to the situation. PBS for unloading vehicle determination method of the invention includes a PBS having a forwarding lane from PBS outlet to PBS inlet, and trim the buffer, in a vehicle assembly line sequentially comprises the assembly process, the plurality of in presence of PBS When deciding which of the painted car bodies to be transported to the assembly process first, each time one car body is transported from the PBS, a weight value for the ratio of the number of assembled cars among multiple types of car models is set against the set ratio. Based on the difference in the ratio of the actual number of units to be assembled, the weight value for the number of units to be transferred is determined based on the filling condition of the trim buffer between the PBS and the subsequent assembly process. From among the unloading candidate vehicle bodies that have stock parts assigned among the plurality of vehicle bodies and satisfy other predetermined absolute conditions, at least based on the weight value related to the assembly number ratio and the weight value related to the number of forwarded vehicles, The vehicle body to be carried out to the assembly process is determined first.
[0006]
According to such a method, each time one vehicle body is carried out from the PBS, a weight value related to the assembly number ratio and a weight value related to the number of transported vehicles are obtained, and based on at least those weight values, a plurality of vehicle bodies present in the PBS are present. Of these, the body to be transported to the assembly process is determined from among the unsuccessful car bodies that have been assigned inventory parts and satisfy other predetermined absolute conditions. It is possible to change the value settings according to the assembly performance status in the assembly process and the filling condition of the trim buffer, and to change the values to the assembly process in a more appropriate permutation. Can be carried out.
[0007]
In the method of the present invention, when carrying out with priority the vehicle body determined based on at least the weight value related to the assembly number ratio and the weight value related to the number of transported vehicles from among the carry-out candidate vehicle bodies, If there is a vehicle, a weight value related to the offline date is obtained for each vehicle body based on the degree of delay in starting the assembly work, and an assembly process is first performed among the plurality of vehicle bodies based on the weight value related to the offline date. It is also possible to determine the vehicle body to be carried out.
[0008]
In this way, when there are a plurality of vehicle bodies determined to be carried out, the vehicle body to be prioritized for compliance with the offline date can be carried out from the PBS first.
[0009]
Furthermore, in the method of the present invention, when selecting the carry-out candidate vehicle body by allocating the inventory parts, the inventory parts are only supplied from the head of each storage lane of the PBS based on the number of trim buffers filled. May be assigned.
[0010]
Allocation of stock parts to a conventional PBS seated car body is performed when the painted car body that has gone through the painting process enters the PBS, or the painted car body that comes out of each storage lane is a branch point between the trim buffer and the forwarding lane. In the former case, stock parts may not be allocated to the car body to be carried out due to the limit of the number of stocks. Filling the trim buffer as described above, even if the car body was moved to the PBS outlet in the order of loading the car model in consideration of the organization of the attaching work, there was a case where the stock parts were not allocated and moved to the forwarding lane. Based on the situation, if inventory parts are allocated only from the beginning of each storage lane to the number of trim buffer storage units that are forwarded to the forwarding lane, inventory parts can only be found in the vehicle that can be carried out. Since parts will be allocated, the inconvenience of not being able to allocate stock parts to the body to be carried out can be effectively prevented even with a limited number of stocks. The vehicle body can be carried out in accordance with the order in which the vehicle types are taken into account in consideration of the attachment work.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a flowchart showing a processing procedure of one embodiment in which the PBS carrying body determination method of the present invention is applied to a PBS of an automobile assembly line as a vehicle, and FIG. 2 is a carrying out method according to the embodiment. FIG. 3 is a layout diagram showing a PBS for determining a vehicle body. The PBS shown in FIG. 2 has a plurality of storage lanes 1 each constituted by a conveyor line, and these storage lanes 1 are located at the end of the PBS inlet 2. Each of them branches and merges before the PBS outlet 3, and in these storage lanes 1, a painted vehicle body 5 that is sent from a painting process (not shown) by a lifter 4 and entered from the PBS inlet 2 by a conveyor line. However, a plurality of units are stored by being sorted in order from the storage lane 1 with a small number of seats and arranged in advance in each storage lane 1.
[0012]
The PBS outlet 3 of the PBS is connected to another lifter 7 that leads to an assembly process (not shown) via a trim buffer 6 that can store four vehicle bodies 5 in this example. The outlet 3 is provided with a transfer lane 8 that is a conveyor line that branches from the conveyor line toward the trim buffer 6 and goes to the PBS inlet 2.
[0013]
Therefore, here, an assembly line management computer (not shown) executes the processing shown in FIG. 1. In step 11, initial processing such as variable initial setting processing is performed for each shift or each day. Then, it is determined whether or not there is a request for carrying out the painted vehicle body 5 from the assembly process.
[0014]
If there is a request for unloading, the process proceeds to step 13, and if it is not established, assembly work cannot be performed. Therefore, it is absolutely necessary that the condition is satisfied for unloading, for example, assembly of assembly work in the assembly process. (For example, every two sunroof specification bodies) or continuous numbers (for example, up to four automatic transmission specification bodies), important inventory parts (engines and transmissions, etc.) Etc.) and that pre-trim work (preliminary assembly of sunroof parts, etc.) has been completed, etc. Select multiple vehicle bodies as carry-out candidates.
[0015]
In addition, when allocating the inventory parts, in this embodiment, the inventory parts are allocated only from the head of each storage lane 1 of PBS to the number of units based on the filling state of the trim buffer 6. That is, since the trim buffer 6 can store four vehicle bodies 5, for example, as shown in FIG. 2, there are two vehicle bodies 5 stored therein, and until the two vehicles enter the assembly process. Assuming that only two vehicle bodies 5 can be sent through the forwarding lane 8 at most from the PBS storage lane 1 in the meantime, each of the storage lanes 1 surrounded by a two-dot chain line in FIG. From the beginning of the vehicle to the third vehicle body 5 is the vehicle body that can be carried out at the present time, and here, only the vehicle body 5 near the head is assigned the stock parts. Therefore, the above-mentioned carry-out candidate vehicle body is any one of the vehicle bodies 5 near the head.
[0016]
In the next step 14, in order to determine the body to be transported first from among the above candidates to be optimal for leveling of assembly work and shipping time management, the following three sufficient conditions are set as before: In other words, (a) a ratio condition that the ratio of the number of assembled vehicles among a plurality of types of vehicles satisfies the set ratio (contains within a predetermined tolerance with respect to the set ratio), and (b) the number of forwarded vehicles for unloading (of the storage lane In order to pay out the vehicle body that is not at the top to the PBS outlet, the number of the vehicle bodies on the front side of the storage lane from the PBS outlet is returned to the PBS inlet through the forwarding lane is less than the predetermined number (accordingly) setting a forwarding number provided that unloading can be) in a short time, the date is checked and offline date its proximity, each to their three sufficient conditions weight value (c) off-line (delivery from the factory) , Based on weighting by their weight values to determine the vehicle body for unloading above.
[0017]
However, in the method of this embodiment, the weight values of the respective conditions are not fixed, and the weight values of the respective conditions are reset to 1.0 in the initial process of the step 11, respectively, as shown in the flowchart of FIG. It is obtained as needed based on the state of the assembly line at the time of execution of step 14 (current time).
[0018]
In step 21 in FIG. 3, ranking is performed under the ratio condition (a) above, and ranking under the ratio condition is performed by a conventionally known Thali calculation. “Tully calculation” is a calculation method that repeats the process of sequentially adding appearance probabilities, selecting an item when 1 is exceeded, and subtracting 1 from the cumulative value of the item, for example, producing If there are three types of cars, A, B, and C, and the ratio of the number of vehicles produced is 2 for the A car, 3 for the B car, and 5 for the C car, the appearance probability is 2 / (2 + 3 + 5) for the A car. = 0.2, Car B is 3 / (2 + 3 + 5) = 0.3, Car C is 5 / (2 + 3 + 5) = 0.5. Cumulative values are 0 for Car A, 0 for Car B, 0 for Car C, and add once. After that, Car A is 0.2, Car B is 0.3, Car C is 0.5, and after adding twice, Car A is 0.4, Car B is 0.6, Car C is 1.0. Therefore, at this time, the C car is first selected and 1 is subtracted from the accumulated value of the C car to 0.
[0019]
After adding three times, Car A is 0.6, Car B is 0.9, Car C is 0.5, and after adding four times, Car A is 0.8, Car B is 1.2, Car C is 1.0. Therefore, at this time point, the B car and the C car are selected, and 1 is subtracted from the accumulated values of the B car and the C car to obtain 0.2 and 0, respectively. After adding 5 times, Car A will be 1.0, Car B will be 0.5, Car C will be 0.5. Therefore, at this time, the A car is selected and 1 is subtracted from the accumulated value of the A car to 0. After adding six times, the A car is 0.2, the B car is 0.8, and the C car is 1.0. Therefore, at this time, the C car is selected and 1 is subtracted from the accumulated value of the C car to be 0. In addition, after adding seven times, the A car is 0.4, the B car is 1.1, and the C car is 0.5. Therefore, at this time, the B car is selected and 1 is subtracted from the accumulated value of the B car to 0.1.
[0020]
After adding 8 times, the A car is 0.6, the B car is 0.4, and the C car is 1.0. Therefore, at this time, the C car is selected and 1 is subtracted from the accumulated value of the C car to be 0. After nine additions, the A car is 0.8, the B car is 0.7, the C car is 0.5, and after ten additions, the A car is 1.0, the B car is 1.0, and the C car is 1.0. Therefore, at this time point, the A car, the B car, and the C car are selected, and 1 is subtracted from the accumulated values of the A car, the B car, and the C car to be 0 respectively. Thus, the carry-out order is C car, B car, C car, A car, C car, B car, C car, A car, B car, C car, and the ratio of A car to B car to C car. Is 2 to 3 to 5 set as described above.
[0021]
In this way, in step 21 described above, the carry-out rank is assigned to each of the plurality of vehicle bodies 5 as carry-out candidates for each vehicle type, and in the following step 22, the weighting of the ratio condition itself is calculated. Alternatively, on the basis of the production planned number of the day, first, the ratio of the production planned number of each vehicle type to the entire production planned number is obtained. For example, if the total number of production units is 200, of which 100 are A, 50 are B, 30 are C, and 20 are D, A is 0.5, B is 0.25, and C is 0.15, and for D cars 0.1. When these values are plotted on the axes of the two-dimensional graph and connected with straight lines as shown in FIG. Next, here, the ratio of the number of each vehicle type in the 200 vehicle bodies 5 of the certain number of vehicles carried out in the assembly process before the present time, for example, the total number of the production planned above is obtained. For example, assuming that there are 80 cars A, 60 cars B, 40 cars C, and 20 cars D, car A is 0.4, car B is 0.3, car C is 0.2, car D is 0.1. When these values are connected with straight lines as plots on the axes of the two-dimensional graph, a result area Q is obtained. In this example, the area of the portion R in FIG. 4 where the plan area P and the actual area Q overlap is divided by the area of the plan area P to obtain the area ratio B (B <1.0). Further, the original ratio weight value 1.0 is divided by the area ratio B to obtain the current ratio weight value. Therefore, the area ratio B becomes smaller as the actual ratio deviates from the planned ratio, and the ratio weight value becomes larger than 1.0.
[0022]
In the next step 23, ranking is performed under the condition of the number of forwarded vehicles described in (b) above, and this ranking is based on the storage lane more than the vehicle body 5 among the vehicle bodies 5 to which the stock parts are assigned. It is assumed that the lower the number of vehicle bodies 5 located on the top side of 1, the higher the order. Accordingly, the vehicle bodies 5 having the same number of vehicle bodies 5 positioned on the front side of the storage lane 1 are given the same rank.
[0023]
In the subsequent step 24, the weighting of the forward vehicle number condition itself is calculated. In this calculation, the number of the vehicle bodies 5 currently seated in the trim buffer 6 is stored in the trim buffer 6 as a facility. To determine the current filling rate A of the trim buffer 6 (A <1.0), and further divide the original forwarding unit weight value 1.0 by the filling rate A to obtain the current forwarding unit weight value. Ask for. Therefore, as the number of seats in the trim buffer 6 decreases, the filling rate A decreases, and the weight value of the number of forwarded vehicles becomes a value greater than 1.0. For example, as shown in FIG. 2, when the trim buffer 6 can store four vehicle bodies 5 and, for example, two vehicle bodies 5 are present there, the filling rate A = 2/4 = 0.5. Thus, the weight value of the number of transported units = 1.0 / 0.5 = 2.0.
[0024]
In the next step 25, ranking is performed based on the offline date condition of (c) above. As shown in FIG. For each of the vehicle bodies 5 that are delayed to the assembly process, the delay time (minutes) of each of the vehicle bodies 5 that are unloaded is divided by the sum of the delay times to obtain the delay time of each vehicle body 5. The weight value is obtained, and the higher the weight value, the higher the ranking. For example, in FIG. 5, the weight value of the delay time of the vehicle body (3) = the delay time of the vehicle body (3) / the total delay time of the vehicle bodies (1) to (4). = Delay time of vehicle body (4) / Total delay time of vehicle bodies (1) to (4). Therefore, here, it is possible to grasp not only the order of delay but also the degree of delay numerically by the weight value of the delay time.
[0025]
In the subsequent step 26, the weighting of the offline due date condition itself is calculated, and in this calculation, the average value of the weight value of the ratio condition previously obtained in step 22 and the weight value of the number-of-feeds condition obtained in step 24 is calculated. Find it and use it as the weight value for the offline due date condition. Thus, in this embodiment, unless the weight value of the ratio condition and the weight value of the forwarding number condition are the same, the weight value of the offline date condition is always the second largest value, and the weight value of the ratio condition and the forwarding number condition Is the largest weight value.
[0026]
In the final step 27, a comprehensive determination is made. Here, out of a plurality of vehicle bodies 5 to be carried out, the vehicle is first carried out to the assembly process in accordance with the one having the larger weight value between the ratio condition and the number-of-forwarding-vehicle condition. The vehicle body 5 to be temporarily determined. When the provisionally determined vehicle body 5 is one, it is determined as the vehicle body 5 to be carried out to the assembly process first, and when the provisionally determined vehicle bodies 5 are plural, the offline date condition is satisfied. In accordance with the ranking, the vehicle body 5 that has the highest ranking in the offline due date condition among the plurality of units is determined as the vehicle body 5 to be carried out to the assembly process first.
[0027]
After determining the vehicle body 5 to be carried out first in the assembly process in this way, in step 15 of FIG. 1, the equipment control PLC (programmable logic controller) is arranged so that the decided vehicle body is carried out to the assembly process. Processing such as transmission of an unloading vehicle body instruction signal is performed.
[0028]
Thus, according to the method of the above embodiment, each time one vehicle body 5 is unloaded from the PBS, (a) the weight value related to the assembly number ratio and (b) the weight value related to the number of transported vehicles are obtained and at least those weight values are obtained. On the basis of the above, the vehicle body 5 that is assigned to inventory parts among the plurality of vehicle bodies 5 that are present in the PBS and that is to be carried out to the assembly process first is selected from among other vehicle bodies 5 that satisfy the above-mentioned absolute conditions. Since it is determined, fluidize the weight value setting for the assembly ratio and the weight value setting for the number of transported units, and change those values appropriately according to the assembly performance status in the assembly process and the trim buffer filling status. Therefore, the vehicle body 5 can be carried out to the assembly process with a more appropriate permutation.
[0029]
Moreover, according to the method of the above-described embodiment, when the vehicle body 5 determined based on the weight value related to the assembly number ratio and the weight value related to the number of transported vehicles among the carry-out candidate vehicle bodies 5 is preferentially carried out, a plurality of vehicle bodies 5 are provided. When there is a vehicle, a weight value related to the offline date is obtained for each vehicle body based on the degree of delay in starting assembly work, and the vehicle body 5 to be carried out to the assembly process is determined based on the weight value related to the offline date. Therefore, when there are a plurality of vehicle bodies 5 determined to be carried out, the vehicle body that should be prioritized for observing the offline date among the plurality of vehicles 5 can be first carried out from the PBS.
[0030]
According to the method of the above-described embodiment, when the stock parts are allocated and the car body 5 to be carried out is selected, the vehicle 5 is forwarded from the top of each PBS storage lane 1 to the forwarding lane based on the filling state of the trim buffer 6. However, since the inventory parts are allocated only to the number of trim buffers that do not run short, the inventory parts can be allocated only to the vehicle body 5 that can be carried out. Inventories can be effectively prevented even with a limited number of stocks, and in addition, stock parts are allocated to the car body 5 that can be carried out. It can be carried out to the assembly process.
[0031]
Although the present invention has been described based on the illustrated examples, the present invention is not limited to the above-described examples. For example, other conditions may be added as the absolute conditions or sufficient conditions. In the condition check, the vehicle body 5 to be carried out to the assembly process is determined based on the one with the larger weight value of the ratio condition and the number-of-forwarding-vehicles condition. Depending on the weight value, the vehicle body 5 to be carried out to the assembly process may be determined in the same manner as in the case of the conventional fixed weight value.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a processing procedure of an embodiment in which the PBS carry-out vehicle body determination method of the present invention is applied to a PBS of an automobile assembly line as a vehicle.
FIG. 2 is a layout diagram showing a PBS for determining a carry-out vehicle body by the method of the embodiment.
FIG. 3 is a flowchart showing a procedure for a sufficient condition check in the method of the embodiment shown in FIG. 1;
FIG. 4 is an explanatory diagram showing a weighting calculation method for ratio conditions in the sufficient condition check shown in FIG. 3;
FIG. 5 is an explanatory diagram illustrating a ranking calculation method based on an offline due date condition in the sufficient condition check illustrated in FIG. 3;
[Explanation of symbols]
1 Storage lane 2 PBS inlet 3 PBS outlet 4 Lifter 5 Painted car body 6 Trim buffer 7 Lifter 8 Forward lane

Claims (3)

And PBS with forwarding lane to PBS inlet from PBS outlet, and trim the buffer, in a vehicle assembly line sequentially comprises the assembly process, previously which body of the plurality of painted car body in presence of PBS When deciding whether to carry out to the assembly process,
Each time a vehicle body is unloaded from the PBS, a weight value related to the assembly number ratio among a plurality of types of vehicles is obtained based on the deviation of the ratio of the actual assembly number to the set ratio,
A weight value relating to the number of forwarded units is obtained based on the filling state of the trim buffer between the PBS and the subsequent assembly process,
Based on at least a weight value related to the assembly number ratio and a weight value related to the number of forwarded vehicles, out of the candidate vehicle bodies for which inventory parts are allocated among the plurality of vehicle bodies and satisfy other predetermined absolute conditions, A method for determining an unloading vehicle body for PBS, comprising: determining a vehicle body to be unloaded to an assembly process. When the vehicle body determined based on at least the weight value related to the assembly number ratio and the weight value related to the number of transported vehicles is preferentially carried out from among the carry-out candidate vehicle bodies, when there are a plurality of vehicle bodies,
A weight value for the offline date is determined for each vehicle body based on the degree of delay in starting assembly work.
2. The method of determining a carry-out vehicle body for PBS according to claim 1, wherein a vehicle body to be carried out first in an assembly process is determined from among the plurality of vehicle bodies based on a weight value relating to the offline date. When assigning inventory parts and selecting the candidate car body to be carried out,
3. The method for determining the unloading vehicle body for PBS according to claim 1 or 2, wherein the inventory parts are allocated only from the head of each storage lane of the PBS to the number of units based on the filling state of the trim buffer.

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