JPH07334226A - Production process correction process support system - Google Patents

Abstract

(57) [Summary] [Purpose] We have constructed a system that supports the process of correcting production equipment such as press dies and welding jigs until products that meet quality standards are produced, and the time required for correction is established. And reduce costs, etc. [Structure] In order to guarantee the quality of parts and products, it is necessary to have information (quality plan) such as which point and how to measure, and which measured value is in what range. This system centrally manages the data required to formulate a quality plan, and also accumulates and stores past quality plans to support the formulation of quality plans. Based on the planned quality plan,
A measurement operation program of the three-dimensional measuring machine is created, and measurement is performed based on the program. The measurement value is analyzed by the accuracy analysis subsystem, and the correction data of the production equipment is obtained based on the result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production facility used for producing parts such as a fender panel and a door panel and assembling those parts to produce a product such as an automobile body, for example, a press die for producing parts. And technology for correcting production equipment such as jigs and welding equipment used in the assembly process. For example, in the case of a press die, a press product as designed is rarely obtained from the beginning, and various corrections are often required until a press product satisfying quality standards is produced. The present invention realizes a system for supporting the correction process of production equipment, thereby shortening the time required until a product that meets quality standards is produced and reducing the cost required for the correction process. is there.

[0002]

2. Description of the Related Art Conventionally, at the production preparation stage of an automobile body, production equipment is modified by the following work (FIG. 2). (1) Quality planning work Positioning standards, accuracy assurance parts, and tolerances of panels and bodies are organized as quality standard documents (= QR below) and measurement part instruction diagrams (= EM below) by incorporating production technology know-how. This is the step of making a quality evaluation plan. This step requires an engineer who has a wide range of experience and knowledge related to quality, and at the same time, it is extremely inefficient because it is done by hand and it responds to frequent design changes. (Figure 3). In addition, cooperation with subsequent operations is all done through paper such as forms, which hinders the smooth promotion of operations.

(2) Measurement preparation work This is a work for producing a tool for measurement, that is, a checking fixture (hereinafter referred to as C / F) based on a quality standard document and a measurement site instruction diagram (FIG. 4). This C / F is a dedicated facility manufactured for each vehicle type and model, and a huge capital investment was required for each model change of the vehicle. There are various types of C / F for measuring the pressed product as a single product and the assembly state, and in terms of operation, there was difficulty in responding to design changes as well as quality planning. On the other hand, in terms of accuracy, individual C / F
It is inevitable that the manufacturing error and the measurement error due to the instrumental difference between the related C / Fs cannot be avoided, which is also a factor to confuse the accuracy analysis work described later.

(3) Measurement work An operator looks at the above-mentioned measurement site instruction diagram (EM) and C
This is the step of measuring the panel or body positioned at / F with a caliper (Fig. 5). In this conventional method, a measurement error such as a variation in measurement result due to manual work has been a potential problem. On the other hand, it is practically impossible to perform a large number of measurements for statistically accurate analysis of pressed products and bodies that have large dimensional variations compared to machined products, or C /
There is a problem that the measurable part is limited by the specification of F, and the accuracy analysis step is made more trial and error.

(4) Accuracy analysis work This is a step in which an engineer plots the measured results, multilaterally analyzes and examines the accuracy, and links the correction results to the press die and welding jig (Fig. 6). ). This work is the most important work in the latter half of the body's production preparation,
In order to shorten the lead time, it must be efficiently implemented within a limited time. However, in addition to the inefficiency of data analysis such as charting, it is necessary to promote the work by trial and error while compensating for the above-mentioned inadequacy of measurement preparation and measurement with the experience of craftsmanship of experienced engineers. It was a tough job for me.

[0006]

SUMMARY OF THE INVENTION The object of the system according to the present invention is to solve the above-mentioned problems of each work and innovate the old-fashioned quality-related work in the production preparation of products. Specifically, the following issues will be realized. (1) Centralized database of quality-related information Engineers share quality information including various charts generated in each step from planning to analysis through computers and networks, and business confusion (redoing) due to information complexity In addition to preventing the above, we will promote Simultaneous Engineering of global product production preparations that transcend distance and time differences.

(2) Numerical standardization of accuracy analysis work CMM for panel / body accuracy measurement (hereinafter CMM)
The high-precision measurement results shown in Fig. 1) can be easily compared and evaluated with CAD standard dimensions, and the numerical standardization that had been limited to the field of design and manufacturing is expanded to the field of process maintenance.
The accuracy analysis work that relied on veteran engineers will be simplified and generalized to improve work efficiency.

(3) Simulation of precision analysis work It is possible to organize various data of measurement results to support and optimize precision analysis of engineers. In addition, simulations such as replacing the accuracy analysis by the panel assembly check with the matching of the data of the measurement results will be realized.
This will shorten the lead time of accuracy analysis work, which is the critical path for body production preparation. In this way, this system not only mechanizes (automates) the measurement work by introducing the CMM, but also softwareizes the measurement method peculiar to parts and products and the accuracy analysis method peculiar to production preparation. It is positioned as an engineering support system that comprehensively supports from business planning to analysis and reforms the business.

[0009]

SUMMARY OF THE INVENTION The present invention is a system for supporting a process of correcting a production facility for producing parts and assembling the parts into a product until a product satisfying quality standards is produced. The shape data storage means for storing the shape data relating to the parts and the assembly state of the parts, the parts, the quality assurance part of the parts, and the quality standard data of the quality assurance part are stored in association with each other. Quality information storage means, quality data storage means, and a quality plan planning subsystem for specifying quality assurance parts and quality standard data of specific parts by referring to data stored in the shape data storage means and the quality information storage means, the quality plan A measurement operation program creation subsystem for creating a measurement operation program of a measuring instrument based on the quality assurance part planned by the planning subsystem, the measurement operation A measurement subsystem that measures the shape of a part produced by the production facility based on a measurement operation program created by the program creation subsystem, and stores the measurement values measured by the measurement subsystem in the shape data storage means. An accuracy analysis subsystem that refers to and analyzes the stored data; and a correction data creation subsystem that creates correction data for production equipment based on the analysis results of the accuracy analysis subsystem.

[0010]

[Operation] According to this system, the engineer involved in production preparation makes a quality plan while referring to the highly reliable information that has been corrected and accumulated in consideration of past experience, production technology and measurement technology. It is possible.
In addition, the information is centralized to the latest one, and it is possible to minimize re-work. With these, a reliable quality plan can be efficiently drafted.

Further, in this system, a measuring operation program is created based on the quality plan, and the measuring machine can be operated efficiently. In addition, many C / that were required in the past
It is possible to eliminate the need to create F and greatly simplify the measurement preparation process. Further, according to this system, most of the measurement process is automated, a large number of measurements can be performed accurately in a short time, and the measurement process is greatly simplified. The measured result is analyzed with reference to the design shape data, and when the quality standard is not satisfied, the factor can be easily grasped. With these, it is possible to create correction data for production equipment, and it is possible to know exactly where and how to make corrections in a short time. Through these, the process of modifying the production equipment until the production of products that meet the quality standards becomes much easier.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment embodying the present invention will be described. The system of this embodiment is mainly composed of a large CMM, and is composed of a computer for processing various data and a network connecting them (FIG. 7).
In the quality planning step, an engineer uses a computer installed in an office to create a quality plan based on the body-shaped CAD data by using a quality planning subsystem (sometimes abbreviated as a product standard system). (FIG. 7 (a), FIG. 23). In the measurement preparation step, the worker uses the reference point subsystem and the measurement operation program creation subsystem to measure the measurement reference point and the measurement operation program based on the body shape CAD data to which the quality plan information transmitted by the worker is added. Are created (FIG. 7 (b), FIG. 23). In the measurement step, the measurement operation program is available at each measurement site through the network,
Measurements are performed using the intelligent measurement function with the same measurement operation program regardless of the CMMs at domestic and overseas machine tool factories and body factories (Fig. 7 (c), Fig. 23). In the accuracy analysis step, all the measurement results are stored in one database machine through the network, so the engineer can use the accuracy analysis subsystem to efficiently perform accuracy analysis regardless of location or time difference. It is possible (FIG. 7 (d), FIG. 23).

Next, each subsystem will be described. (1) Quality planning subsystem (product standard system, Fig. 8) This subsystem is designed to efficiently create a quality plan with little variation due to differences in engineers' abilities and experiences, and a quality standard document and measurement site instruction diagram (Fig. It supports the creation of 3) and creates a database of the results. In particular,
By registering the measurement and analysis know-how for each quality assurance part in the master database in advance, extracting only the necessary information, and combining it, we were able to create a quality standard document for each vehicle type. The quality plan information is integrated into a single database and shared by engineers to prevent information confusion and inconsistency and to ensure reliable and easy response to design changes (Fig. 8). In addition, in order to accurately analyze the accuracy of the welding body, it is necessary to evaluate the same part between the related single unit panel and the sub-assembly. For this reason,
By incorporating the measurement site transfer function and unnecessary point deletion function between related parts, it is possible to reliably and easily determine the measurement site without excess or deficiency.

(2) Reference point system (Fig. 9) This subsystem uses CAD data in the shape of a body with quality planning information added to create measurement operation programs and evaluate the measurement results. A reference value is created for each evaluation. This subsystem does not have to create each reference dimension one by one, but incorporates the quality standard data created in the quality plan and the part name / measurement method in the measurement part data, making it easy to set the reference size according to the measurement part. It is possible to create them all at once with various operations (Fig. 9). At the beginning of the development of this system, this work was performed using a commercially available CAD system, and the work man-hour was one of the bottlenecks in the use of CMM. By developing this reference point system, We are now able to fully demonstrate the advantages of high-speed multipoint measurement.

(3) Measurement operation program creation subsystem (FIG. 10) This subsystem is composed of two systems.
One is a commercially available simulation system (IGPI
This is an offline teaching system in which P) is customized and Toyota's ingenuity is elaborated. The devising points are the mutual conversion function of the measurement operation program between CMMs (cantilever type ← → gate type) with different structures, and the function to automatically create the measurement operation program based on the measurement reference dimensions received from the reference point system. In addition, Toyota has realized the functions unique to Toyota, such as the data operation function for each panel or body evaluation group. Needless to say, the greatest merit of this system is that it contributes to the need for an ever-increasing measurement load by increasing the operating rate of the CMM by eliminating teaching using the CMM (Fig. 10).

On the other hand, as a subsystem similar to the above-mentioned simulation system, only rough movement using the CMM is performed on a computer after performing a rough teaching only on the operation of moving from a measurement point to the next measurement point while avoiding an interfering object. A measurement operation program is created in combination with CAD data. This subsystem is used for flexibly responding to design changes at the measurement site of each factory that does not have an expensive simulation system. The measurement operation program creation subsystem is effective under all conditions by using the two subsystems properly.

(4) Intelligent Measuring Subsystem In order to automatically measure a sheet metal object such as a panel or body with high accuracy, it is necessary to use a measuring method in consideration of the characteristic that the dimensional variation is large. For this purpose, the function of guiding the probe to the target position while searching for the deviation of the object to be measured (= search guidance) and the function of immediately calculating the measured value and checking the contact state (= contact state determination) ) Is essential (Fig. 11). For example, in the lid parting part of the body, it is necessary to evaluate the accuracy of the parting line at the end of the section R. That is, in the conventional general measurement aiming at a fixed point, there is a high possibility of picking up an error such as measuring the section R part due to the deviation of the panel itself or the deviation of the whole body, but using this original function of Toyota The error is 1 /
6 (FIG. 12). In addition, a function was developed to prevent the processing defects (section R sag, etc.) from being picked up as a measurement error by calculating the flatness around the hole when measuring the hole. These functions must be built into the CMM controller,
User customizable control system (D
This is achieved by selecting EA MASTER). As a result, not only the measurement accuracy is improved, but also the continuous unmanned operation for a long time is possible without being hindered by the abnormal stop of the CMM due to the poor accuracy of the measured object, which is likely to occur in the initial stage of production preparation.

(5) Precision Analysis Support Subsystem This system outputs various diagrams in order to utilize the measurement results and support precision analysis. Here is an example of this output: The first example corresponds to a dimensional accuracy table that has been familiar to the past, and an example of this is the accuracy table for pressed products. Analyze the results of multi-sample measurement in addition to the conventional information such as CMM measurement result error display along the surface, tolerance judgment for judging good or bad from the measurement result, and illustrations that associate the measurement result with the measurement position And a precision comparison bar graph before and after repair of the press type are displayed (FIG. 13). In this way, by automatically outputting the accuracy table with increased added value, we have tried to break away from the conventional simple display of measurement results to an accuracy table that is easy to use as a means of analysis.

The following example is a docking output diagram in which a graph of a result obtained by accurately measuring a welded joint portion at a small pitch and a body shape are combined in order to perform plate alignment analysis of a spot welded joint (FIG. 14). ). By using this output, it became possible to perform accuracy analysis based on data without performing plate-matching analysis in which single panels were combined.

In addition, as an example of a new output form, there is a function of assembling and displaying the measurement results of the adjacent objects to be measured by utilizing the high speed of the computer. By rotating and moving the measurement results individually, it is possible to simulate the optimum assembly condition. This made it easy to study the optimum repair method for individual parts. In addition, by using this output and simulating the measurement results of the press die and panel on top of each other, it can also be used for analysis of the dimensional change of the pressed product caused by the effect of elasto-plastic deformation during press working. (Fig. 15). In this way, this subsystem enables precision analysis, which was difficult with the conventional method.

(6) Others Various information such as the measurement operation program and the measurement result described above are centrally managed by one database machine via the network (FIG. 7). In addition, the operation of each subsystem is unified with a graphical user interface, so that even experienced engineers and workers who are not familiar with computers can easily operate it. Most of the subsystems are bilingual (Japanese & English), which enables users to utilize the measurement information by themselves between offices and factories dispersed in Japan and overseas. It should be noted that the information in the database is protected so that only the information within the range permitted for each user can be registered and referenced.

Next, utilization of this system will be described.
Based on the development and commercialization of the panel body precision CAT system, Toyota is promoting a revolutionary business reform in all quality work from planning to precision analysis. In quality planning, measurement preparation, and measurement operations, unification of quality information, mechanization of operations, elimination and simplification of dedicated jigs, etc., have contributed significantly to improving work efficiency and reducing capital investment. Also, in accuracy analysis work, we have improved reliability by realizing numerical standardization and simulation of the work, and we are proceeding with work reform including revamping and abolishing the work steps. The outline will be described below.

(1) Improvement of reliability of accuracy analysis As described above, conventionally, the measurement error and the limit of man-hours caused by the C / F itself and manual work hindered improvement in efficiency of analysis and correction. By reducing the measurement error in half and increasing the number of samples, we were able to greatly improve the reliability of analysis work (Fig. 16). Furthermore, with the progress of practical use of this system, statistical methods have become established in accuracy analysis work.
By utilizing the above-mentioned pressed product accuracy table and comparing and examining the average value and variation of the data for each tri-step, it has become possible to perform more accurate correction instructions with less man-hours than ever before. Moreover, the measurement range has been limited by the use of C / F in the past, but the range was expanded by the measurement by CMM. For example, in main body, the attachment parts (interior / exterior parts / foot parts) are newly measured, and the accuracy guarantee range is greatly expanded (FIGS. 16 and 17).

(2) Business innovation of body accuracy analysis Generally, a panel of an automobile body is a thin plate and has poor shape fixability and large dimensional variation. Then, it is very complicated to assemble the panels with the variations and analyze the accuracy of the body. In order to analyze this body accuracy in a short period of time, each body maker uses its own method. As a realistic and efficient method, Toyota basically proceeded with the accuracy analysis of the body by dividing it into two steps with different aims (Fig. 18). In one step, the actual panel is assembled in the C / F and the C / F
By measuring the body by F, the plate matching analysis between the panels is performed, and the press die is corrected.

The other step is to assemble the body in a mass-production welding facility and measure the body by C / F to analyze the process capability of the welding facility and adjust the welding facility. These steps are the critical path for body production preparation, and there is an urgent need to improve them.
We have used this system to tackle the dynamic operational reform of this process.

First, regarding the reform of the steps of the pressed product / body accuracy analysis, first, the measurement by C / F was replaced by CMM. As a result, a very expensive main body C / F
Can be abolished and a large reduction in capital investment has been realized. In addition, single C / F, main body C / F, each C / F
Since it is not necessary to cross-check the manufacturing accuracy difference between F and the welding equipment, work efficiency can be improved. Next, we also abolished the C / F for press / body accuracy analysis, assembly in welding equipment, and measurement of the assembled body with CMM, and this is called "data assembly". It was replaced with the plate matching analysis by butt matching. That is, the measurement results of a single panel were processed by the docking output function, and the board alignment analysis was possible without assembling the body. This was realized by combining the know-how accumulated in the conventional board matching analysis, the high-speed multipoint precision measurement capability of the CMM, and the system for processing the results (Fig. 18).

On the other hand, in the step of process capability analysis, the CMM is based on a clear target value obtained early in data assembly.
Taking advantage of the high-speed automatic measurement capability of, we are measuring much more bodies than before to confirm reproducibility. As a result, we were able to clarify the phenomena and causes of dimensional variation early on, and improve the efficiency of work from grasping the process capability of welding equipment to equipment adjustment. As a result, it is possible to reduce the lead time of body accuracy analysis work, which has been a critical path for body production preparation, by reducing the number of analysis steps and by performing parallel processing of accuracy analysis for press die correction and welding process capability analysis. did it.

(3) Preparation for parallel production at remote locations With the expansion of overseas production, the local procurement of equipment and panels overseas is also increasing. By applying the above-mentioned "data assembly analysis" in preparing the production of these parts, it is possible to prepare for production over a distance without being restricted by the transportation of goods. In other words, there are panels that are procured in Japan (daily preparations) and those that are procured locally overseas (current preparations). In the past, if accuracy analysis was performed in Japan, If it was done overseas, it would be done by sending daily products to the other party and assembling the panel.
Since this system has been deployed overseas, it is possible to analyze the panels at the same time by measuring the panels in Japan and overseas and sharing the measurement results. This enabled simultaneous production preparations on a global scale, and enabled engineers with highly specialized skills to support precision analysis of panel bodies worldwide.

[0029]

【The invention's effect】

(Qualitative effect) As described in the explanation of measurement preparation and measurement work, the conventional method makes the accuracy analysis work unreliable due to the lack of measurement error and the number of measurement samples, which is a severe work for engineers. It was However, by utilizing this system, it was possible to reduce the measurement error by half and increase the number of samples, and when this effect was compared statistically, the reliability of accuracy analysis work could be improved to four times that of the conventional method (Fig. 19). As a result, the accuracy analysis work has been simplified and generalized, contributing to the early securing and stability of quality in production preparation.

(Quantitative effect) In terms of evaluation without leakage, conventionally, the use of C / F limits the measurement range of the object to be measured, which is not always sufficient for accuracy analysis. Since this system enables high-speed measurement by CMM, the measurement amount has been increased to 8 times that of conventional panel measurement and 18 times that of body measurement (Fig. 20).

(Cost effect) The expensive main body C / F, which is the dedicated equipment manufactured for each model change of the vehicle, can be abolished and replaced with the general-purpose equipment CMM. This return on investment is 50 when the CMM investment amount is 100, and the investment reduction amount due to the abolition of one main body C / F is 50. Therefore, the investment amount for the CMM introduction is amortized by two model changes. (FIG. 21). In addition, other C / Fs other than the main body C / F are being reduced and simplified.

(Timing) Accuracy analysis The panel matching analysis, which is the core of the work, cannot be started until the measurement of all the panels to be assembled has been completed because of the panel assembly. Was needed. However, the use of this system made it possible to compare data as soon as the relevant panel was measured. In addition, by improving the reliability of accuracy analysis work,
Rework of welding equipment has been reduced. This made it possible to significantly reduce the lead time (Fig. 22).

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a coordinate measuring machine.

FIG. 2 is a diagram showing tasks executed in a production preparation stage.

FIG. 3 is a diagram showing an example of a quality standard document and a measurement site instruction diagram.

FIG. 4 is a diagram illustrating a checking fixture.

FIG. 5 is a diagram showing work contents of conventional measurement work.

FIG. 6 is a diagram showing an example of correction data of production equipment.

FIG. 7 is a system configuration diagram of an embodiment.

FIG. 8 is a diagram showing a quality planning subsystem.

FIG. 9 is a diagram showing a reference point subsystem.

FIG. 10 is a diagram showing a measurement operation program creation subsystem.

FIG. 11 shows an intelligent measurement subsystem.

FIG. 12 is a diagram showing a measuring method of a parting portion.

FIG. 13 is a diagram showing an example of a precision table of a pressed product.

FIG. 14: Docking output diagram combining measurement data and shape data at welded joint

FIG. 15 An example of an analysis diagram of elasto-plastic deformation of a pressed product

FIG. 16 is a diagram showing the reliability of analysis work in comparison with the conventional one.

FIG. 17 is a diagram showing a precision guarantee range.

FIG. 18 is a diagram showing the contents of reform of accuracy analysis work.

FIG. 19 is a diagram showing the reliability improvement result of accuracy analysis work.

FIG. 20 is a diagram showing the number of measurement points.

FIG. 21 is a diagram showing required costs

FIG. 22 is a diagram showing a required period.

FIG. 23 is a diagram showing a list of functions of the embodiment.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Kito New Year, Toyota City, Toyota City, Aichi Prefecture, 1st Toyota Motor Co., Ltd. (72) Inventor, Kenji Inai, Toyota City, Aichi Prefecture, Toyota City, Toyota 1 (72) Inventor Shoji Shinma 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. A system that supports a process of correcting a production facility that produces parts and assembles the parts into products until a product that meets quality standards is produced. Shape data storage means for storing shape data relating to a state, quality information storage means for storing a part, a quality assurance part of the part, and quality standard data of the quality assurance part in association with each other, the shape data storage Means and a data stored in the quality information storage means to identify a quality assurance part and quality standard data of a specific part, and a quality assurance part designed by the quality planning part subsystem. A measurement operation program creation subsystem for creating a measurement operation program for a measuring instrument based on A measurement subsystem that measures the shape of a part produced in the production facility based on the measured operation program, and the measurement values measured by the measurement subsystem are referred to the data stored in the shape data storage means. And a precision analysis subsystem for performing analysis, and a correction process creation system for production equipment, which includes a correction data creation subsystem for creating correction data for production equipment based on an analysis result of the accuracy analysis subsystem.