JPH0588711A - Method and device for back-up of assembly line plan - Google Patents

Abstract

PURPOSE:To enable even a designer having no storage of the know-how and the knowledge to easily and systematically plan an assembly line with no in all fields. CONSTITUTION:A request production system input part 2 is provided together with a CAD information reading part 3, an assembling operation describing part 4, a process desiring part 6, a data base 5, a simulator 8, and a simulator data conversion part 7. Meanwhile an input step of a request production system is prepared together with a CAD information reading step, a step where the work time is calculated with the input of an assembling property evaluation symbol and an assembling order, a step where a process designer is carried out based on the request production system, a step where the process design result is converted into a simulation model, a simulation executing step, and a step where the simulation executing conditions are continuously changed until the simulation result is coincident with the deciding conditions and then the simulation is carried out. In such a constitution, a proper assembly line is easily designed regardless of the know-how and the knowledge of a designer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for supporting an assembly line plan based on a required production system.

[0002]

2. Description of the Related Art In planning or assembling a factory assembly line, it is important to reduce the time required for planning and homogenize the plan. Conventionally, as represented by Japanese Patent Laid-Open No. 61-249235, an expert system is used to realize a plan of an assembly system. This is to input only the required production method for the entire system such as production quantity, investment amount, lead time required production method and the aim of the conveyance means and the component supply means, and output the proper system configuration.

[0003]

In the conventional factory assembly line planning, an assembly line plan was created by a trial and error method, evaluated, and repeatedly corrected. With this method, various knowledge is required to create a draft of an assembly line in a factory, and therefore, only a planner who has accumulated know-how and knowledge can draft a proper draft of an assembly line. Even for a designer who has accumulated know-how and knowledge, not all plans are appropriate because there are fields with a lot of know-how and knowledge depending on the designer and fields with a few.

Further, in the conventional method of planning the assembly system,
The main purpose is to design an assembly station centered on robots, and it is not intended to plan an assembly line that takes physical distribution into consideration, so a systematic assembly line could not be planned. Furthermore, since it was necessary to successively input the necessary information by hand, the operability was poor and it did not function as a simple planning support method.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for solving the above problems of the prior art, which is systematic in consideration of assembling work of individual parts and can easily plan an assembly line. ..

[0006]

In order to achieve the above object, CAD information is read by inputting a required production method, and an assembling evaluation symbol and an assembling order of parts to be assembled based on the read CAD information. Calculate the work time by inputting, and execute the process design so that the work time is completed within the standard time and the required production method is satisfied,
The executed process design result is converted into a simulation model, the simulation is executed, the simulation execution condition is changed and the simulation is executed until the simulation result matches the determination condition, and the assembly line plan is optimized. I decided to do it.

[0007]

Function: The designer who plans the assembly line inputs the required production method. Next, information about the part name, quantity, and weight is extracted from the drawing information and CAD information of the corresponding product. When the designer describes the assembling operation of the relevant component by the assembling performance evaluation symbol, the present invention calculates the working time of the assembling operation and standardizes the process. Next, the standardized process is converted into a simulation model and evaluated. The designer optimizes the design by changing the conditions and evaluating until the evaluation result is as intended.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing the flow of work performed in the present invention.
The required production system shown in this figure will be described later with reference to FIG.
FIG. 2 is an example of a device configuration for realizing the present invention. First,
In step 1 of FIG. 1, the required production method is input. This is done by the designer 1 shown in FIG. 2 inputting information to the required production method input unit 2 such as the names of parts to be assembled and the conveyor speed. The input required production method is sent from the required production method input unit 2 to the database 5 and saved as a file. Next, the corresponding C in step 2 of FIG.
Read AD information. This is performed by the CAD information reading unit 3 of FIG. 2 acquiring CAD information such as information on the part name, quantity, and weight from the corresponding drawing information and parts table information from the database 5 and passing it to the assembly operation description unit 4. Be seen. In step 3 of FIG. 1, the assembling performance evaluation symbol and the assembling order are input and the working time is calculated. This is because the assembling operation description unit 4 of FIG. 2 presents the CAD information on the screen,
The designer 1 inputs the assemblability evaluation symbol and the assembling order. The process design means designing a group of work including at least one of the assembling operations input to calculate the work time output in step 3.

Next, in step 4, a process design is executed based on the required production system. This is performed by referring to the file relating to the required production method input from the database 5 by the process designing unit 6 in FIG. Step 5 of FIG.
In the above, steps 2 to 4 are performed without exception for a subassembly line for assembling a subassembly, which is an assembly of a plurality of parts.

Steps 6 and 8 of FIG. 1 are executed by the simulation data conversion unit 7 of FIG.
Is executed by the simulator 8 of FIG. Change the condition with step 9 that determines whether or not the condition of FIG. 1 (contents of the condition will be described later with reference to FIG. 17) is satisfied, and step 11 that outputs specifications. In Step 10, all the steps are performed by the process designing unit 6 of FIG. 2, and the result is presented to the designer 1.

Each step will be described in detail below.

FIG. 3 shows the items of the required production method input in step 1. The foreman in the figure usually means an operator who monitors the operating state of the machine on the assembly line and supplies parts. The component buffer size is the amount of components to be prepared for assembly, and the component transport size is the amount when components for assembly are transported. The “name” is the name of the assembly line, and the CAD information reading unit 3 in FIG. 2 has a function of instructing the CAD information to be accessed. The conditions of "conveyor speed", "failure rate", "failure recovery time", "setup change time", "production variation rate", and "simulation time" are condition values that cannot be changed during the planned execution of the assembly line according to the present invention. "Production model" is CA
Since the D information reading unit 3 can automatically obtain the CAD information when reading it, the designer does not have to input the CAD information. The optimum values of the "Foreman number", "parts buffer size", and "parts transfer size" differ for each station of the assembly line as the assembly line plan is advanced.
Here, the station is composed of an assembling apparatus installed along the conveyor of the assembling line, and one apparatus is called one station. Therefore, the value input in the stage shown in FIG. 3 is a default value (a value automatically given in advance), and a unique value is determined for each station as the optimization of the plan proceeds. It will be the final specification.
By inputting the value of “the number of production models”, the “number of production by type” is automatically provided with a field for inputting the required number. All the information shown in FIG. 3 is stored in the database 5 of FIG. 2 after the designer's input is completed.

FIG. 4 shows the details of step 2 in FIG. In step 21, the information of the assembly drawing is read and displayed as a drawing image on the screen, and in step 22, the information of the parts table is read and displayed on the screen. This is done in order to let the designer confirm on the screen whether the read information is what the designer has instructed. The CAD information is stored in the database 5 of FIG. 2, and the information regarding the parts table means the information of the contents shown in FIG. 5, such as the drawing number, the quantity of parts, and the department. When the quantity data is shown in FIG. 5 as a combination of numbers and alphabetical symbols, this part is an assembly of a plurality of parts (hereinafter referred to as a subassembly, and an assembly line for assembling the subassembly is a subassembly). The line 11 is referred to, and the assembly line for finally assembling the parts or subassemblies is referred to as the total assembly line 10. The relationship between the total assembly line and the assembly line is shown in Fig. 20. By analogy, the mainstream is the total assembly line 10 as opposed to the tributary subassembly line 11.)

FIG. 6 shows a state in which the information of the parts table is read in the total assembly line specification information. In the present invention, among the information shown in FIG. 5, as shown in FIG.
Information on "quantity" and "weight" is used. In the present invention, the data relating to the parts table is read, and when the quantity data is represented by numbers and alphabetical symbols, it is determined that this part is a subassembly, and the assembly for completing the assembly of the subassembly is completed. Suppose a line exists. In other words, a subassembly,
It is a unit that performs one function of a product to be assembled. Therefore, in the present invention, as shown in FIG. 7, the assembly line specification information is created, and the C regarding the assembly drawing and the parts drawing of the assembly is shown.
AD information is acquired according to steps 21 and 22 of FIG. The assembly line specification information shown in FIG. 7 is generated by the number of assembly products.

FIG. 8 shows step 3 of FIG. 1 in detail. In step 31, the drawing image of the assembly drawing and the total assembly line specification information are displayed on the screen. FIG. 18 shows an example of a display format of information on the screen in step 31. Calculator 9
Display has 2 windows for displaying information
One is provided. One is for showing the drawing image of the assembly drawing, and the other is for showing the total assembly or subassembly line specification information. In the example of FIG. 18, a window is provided on one screen to display the information, but two screens are prepared to show the means for showing the drawing image and the total or division line specification information. There is no change in functionality even if it is made independent as a means for doing so.

In step 32 of FIG. 8, the designer inputs the assembling operation and representative dimensions of each part using the assembling property evaluation symbol. In this case, the designer works on the screen as shown in FIG. The representative dimension is the dimension when handling the corresponding part, and is the maximum value of the outer diameter dimension. The designer looks at the assembly drawing, reads the dimensions that match the representative dimensions, and inputs appropriate values. By observing the assembly drawing, the designer can understand which part is attached to which part and how. Therefore, the method for assembling is expressed using the assemblability evaluation symbol, and entered in the total assembly line specification information. FIG. 21 shows an example of the assemblability evaluation symbol. FIG. 9 shows the total assembly line specification information in which the representative dimensions and the assembling property evaluation symbols are input.

In step 33 of FIG. 8, the working time is calculated from the inputted assemblability evaluation symbol, weight and representative dimension. Here, for each assemblability evaluation symbol, the time required for performing the work corresponding to the part having the reference weight and the representative dimension is set in advance as the standard work time. Generally, it is said that the time for performing an assembling operation of a component having an arbitrary weight and a representative dimension is proportional to the reference weight and the representative dimension. For example, it is assumed that the time required for performing a certain assembly work is T _S , the reference weight is M _S , and the reference representative dimension is L _S. The weight and representative dimension of any part
_In the case of _C and L _C, the working time T _C for assembling this component is given by the formula T _C = T _S × C _W × (M _C / M _S ) × C _L × (L _C / L _S ). In this equation, C _W and C _L are called correction factors, and are given by the weight of the part and the absolute value of the representative dimension. FIG. 10 shows the total assembly line specification information indicating the work time after the calculation. The calculation result is written in the work time column.

In step 34 of FIG. 8, the designer inputs the assembly order of parts or subassemblies. The information shown in FIG. 10 and the like read from the database 5 of FIG. 2 is not necessarily arranged in the order of assembling. Therefore, it is necessary for the operator to input the order of assembling arbitrary parts (simply called the order). At this time, since the drawing image of the assembly drawing and the total assembly line information are simultaneously displayed on the screen as shown in FIG. 18, the designer can easily analogize and input the assembly order of the parts. FIG. 11 shows the total assembly line specification information in which the order is input. Next, in step 35 of FIG. 8, the data are arranged in order. FIG. 12 shows an example in which the result of arrangement is written in the total assembly line specification information.

FIG. 13 shows the details of step 4 in detail. In step 41, 1 is given as an initial value to the variable j of the assembly order. The variable k of the assembly order in step 44 represents the starting number when the assembling work of the total assembly line specification information shown in FIG. 12 is summarized, and the variable j represents the ending number. When there is no work to put together (to put together, it is synonymous to realize a plurality of assembling operations in one station, that is, to take charge at one opportunity)
That is, when one station is configured by one assembling operation, the values of the variable k and the variable j are the same. In the condition judgment in step 42, the completion of the work is checked.
This condition is true when the process design has been completed for all the parts shown in FIG. 12, that is, when the variable j matches the number of parts to be assembled. In step 43, the variable c
Give 1 to the ounter. In step 44, the variable k is changed to the variable j
Set to the value of. In step 45, the sum is true while the sum of the work times is smaller than the target cycle time. Therefore, the process proceeds to step 46, and the work time of the assembling operation to make the same station is added. Variable j in step 47
And the value of the variable k are compared, and if they are equal, the work time of one assembling operation is longer than the target cycle time in FIG. In this case, in order to carry out production at the target cycle time, it is necessary to perform the corresponding work at a plurality of stations. Therefore, while the determination condition of step 410 is true, the process proceeds to step 49 to increment the value of the variable counter. If step 410 becomes false, it means that the number of stations for performing the corresponding assembly work in the target cycle time is found, and therefore step 411 is executed.
Therefore, counter stations will be provided for the relevant work.

FIG. 14 shows the total assembly line specification information at the time when step 4 is completed. In this example, the works of the sequences 1 and 2 are independent stations because the work time of each work is smaller than the target cycle time. It is shown that the next M4 screw assembling work requires a longer working time than the target cycle time, and that two M4 screw assembling stations should be provided. It can be seen that the target cycle time is approached if the next rod and plate A are assembled in two stations and one station. Here, the station number is St. 1 in the leftmost column in FIG. Is shown in. This result is the result of numerical optimization, but the designer sees this result and organizes or divides the stations (division is a work of a single assembling operation) depending on the designer's will. If the time is longer than the target cycle time, the number of stations performing the same work can be increased so that the corresponding work can be performed in a time smaller than the target cycle time.).

FIG. 15 shows the details of step 6 in FIG. In step 61, it is set that a buffer exists between the stations indicated by the total assembly line specification information shown in FIG. Next, at step 62, the existence of a buffer for parts to be assembled is set for each station. In step 63, the presence of a buffer for waiting for unloading to the component buffer of the total assembly line and an unloading waiting buffer is set at the end of the subassembly line. In the present invention, since the assembly work time at each station is calculated, it is possible to easily set the above-mentioned buffer by using these.

In steps 64 and 65, the distance between the part buffer and the place where the part is waiting to be carried out is set. Next, in step 66, the total assembly line specification information is translated according to the grammar of the simulation language to create a simulation model.

After completing steps 7 and 8 in FIG.
The obtained simulation result is shown in FIG. FIG. 17
Shows the final form of total assembly line specification information. The designer displays the simulation result of FIG. 16 and FIG.
By simultaneously looking at the final form of the total assembly line specification information of 7, it is determined in step 9 of FIG. 1 whether the planned result by simulation is as intended. If it does not match the intention, the value of the final form (that is, the inter-station buffer size, the component buffer size, the component transport size, the Foreman number) of the total assembly line specification information in FIG.
Modify until the conditions are met. The condition here, that is, the condition of step 9 in FIG. 1 is that the Foreman operation rate shown in FIG. 16 does not exceed 100%.

FIG. 19 is an example in which the final form of total assembly line specification information is represented by a graphical image. As a result, the designer can confirm the overall layout of the total assembly line and the subassembly line, and also the combined state of both. Also, when the designer designates an arbitrary assembly station, the specifications of that station pop up. Moreover, the computer 9 shows the state by animation while executing step 7 of FIG. FIG. 22 shows an example of a device configuration for realizing the present invention. The display 12 is used by a designer to confirm CAD information, confirm information when inputting an assembling operation, and the like. The computer main body 13 is an arithmetic unit that executes a series of processes of the present invention, and includes a required production method input unit 2, a CAD information reading unit 3, an assembly operation description unit 4, a process design unit 6, and a simulation data conversion unit 7 in FIG. , Realizes the function of the simulator 8.

The external storage device 16 realizes the portion of the database 5 in FIG. 2, and the keyboard 14 and the mouse 15 are used for inputting numerical information. The printer 17 is used to print the result of the present invention, for example, the total assembly line specification shown in FIG.

[0026]

As described above, according to the present invention,
Read all the parts information etc. to be assembled from CAD information, understand the parts assembly operation etc. from this information, calculate each work time from each assembly operation, design a standardized process, so accurate work The task of planning the assembly line specifications taking into account time is carried out automatically.
Therefore, the assembly line can be easily designed regardless of the know-how and knowledge of the designer. Further, since the accurate working time of each of the assembled parts is calculated and the process is designed on the basis of the calculated working time, it is possible to deal with a large number of required production method items.

[Brief description of drawings]

FIG. 1 is a diagram showing a flow of work performed in the present invention.

FIG. 2 is a diagram showing an example of a device configuration for realizing the present invention.

FIG. 3 is a diagram showing items of a required production system.

FIG. 4 is a diagram showing in detail the contents of step 2 of FIG.

FIG. 5 is a diagram showing information regarding a parts table.

FIG. 6 is a diagram showing a state in which information of a parts table is read in total assembly line specification information.

FIG. 7 is a diagram showing a state in which information of a parts table is read in the assembly line specification information.

FIG. 8 is a diagram showing step 3 of FIG. 1 in detail.

FIG. 9 is a diagram showing total assembly line specification information in which representative dimensions and assemblability evaluation symbols are input.

FIG. 10 is a diagram showing work time after completion of calculation in total assembly line specification information.

FIG. 11 is a diagram showing total assembly line specification information in which an order has been input.

FIG. 12 is a diagram showing an example in which the result of having been arranged is written in total assembly line specification information.

FIG. 13 is a diagram showing details of step 4 in FIG. 1.

FIG. 14 is a diagram showing total assembly line specification information at the time when step 4 in FIG. 1 is completed.

FIG. 15 is a diagram showing details of step 6 of FIG. 1;

FIG. 16 is a diagram showing a simulation result.

FIG. 17 is a diagram showing a final form of total assembly line specification information.

FIG. 18 is a diagram showing an example of a display format of information on the screen in step 31.

FIG. 19 is a diagram showing an example of a final form of total assembly line specification information.

FIG. 20 is a diagram showing a relationship between a total assembly line and a subassembly line.

FIG. 21 is a diagram showing an example of an assemblability evaluation symbol.

FIG. 22 is a diagram showing an example of a device configuration for realizing the present invention.

[Explanation of symbols]

1 ... Designer, 2 ... Required production method input section, 3 ...
CAD information reading unit, 4 ... Assembly operation description unit, 5 ... Database, 6 ... Process designing unit, 7 ... Simulation data converting unit, 8 ... Simulator, 9 ... Computer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshijiro Ohashi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd. Within the Institute of Industrial Science, Hitachi, Ltd. (72) Inventor Shoji Arimoto Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa 292 Stock Company Hitachi, Ltd.

Claims (7)

[Claims] 1. The CAD information is read by inputting a required production method, and a work time is calculated by inputting an assemblability evaluation symbol and an assembly sequence of parts to be assembled based on the read CAD information. The process design is executed so that the working time is completed within the standard time and the required production method is satisfied, the result of the executed process design is converted into a simulation model, the simulation is executed, and the simulation result matches the judgment condition. Until you change the simulation execution condition, run the simulation,
A method for supporting a plan of an assembly line, characterized by optimizing a plan of the assembly line. 2. When the CAD information is read, the drawing data of the CAD information assembly drawing and the data of the parts table are read and displayed on the screen, and the read data of the parts table is the quantity data and the alphabet symbols. 2. The assembly line according to claim 1, wherein it is determined that the corresponding part is a subassembly including a plurality of parts, and a subassembly line for assembling the subassembly is set. Line planning support method. 3. When inputting an assemblability evaluation symbol and an assembling order of the parts to be assembled, the designer describes an assembling operation using the assemblability evaluation symbol, and inputs the assemblability evaluation symbol.
The working time is calculated from the entered representative dimensions and the weight of the parts list, and the data of the part name, quantity, assembling operation, weight, representative dimensions, and working time are rearranged and displayed according to the assembly order entered by the designer. The method for supporting a plan of an assembly line according to claim 1, wherein: 4. When designing the process, the target cycle time in the required production method is compared with the working time, and the assembly operations are aggregated or the assembly operations are disassembled within a range not exceeding the target cycle time. By doing so, the process of the simulation assembly line is designed, the simulation result is presented to the designer, the simulation condition is changed until the judgment condition is met, and the change result is sent to the simulation data conversion unit. An assembly line planning support method according to claim 1. 5. When converting the simulation data,
3. The process design result is converted into a simulation model in accordance with the grammar of a simulation language, the simulation model is passed to a simulator to execute the simulation, and the simulation result is sent to the process design unit of claim 2. Planning support method for the described assembly line. 6. When designing the process, the parts name in the parts table is used as a subject, and the assemblability evaluation symbol is used as a verb meaning an assembling operation, and the specifications of each process based on the process design result are expressed in sentences. The method for supporting a planning of an assembly line according to claim 4, wherein 7. A demand production method input section to which a demand production method is input, a CAD information reading section for reading CAD information based on the input demand production method, and a part to be assembled based on the read CAD information. A work time is calculated based on the assembling action description part in which the assemblability evaluation symbol and the assembling order are described, and the assembling performance evaluation symbol and the assembling order of the parts to be assembled described above, and the working time is completed within the standard time. A process design unit that executes a process design based on the required production method, a simulation data conversion unit that converts a process design result designed by the process design unit into a simulation model, and a simulation data conversion unit that converts the simulation model from the converted simulation model. The simulation execution conditions are changed until the results match the judgment conditions. Planning support apparatus assembly line, characterized by being configured by the simulator to run.