JP2006264521A - Vehicle assembling accuracy managing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle assembling accuracy managing method capable of accomplishing a stable assembling accuracy management of a completed vehicle by introducing a centralized management of the product accuracy of vehicle components and the assembling accuracy of the components while the components and/or constituent members (sub-assembly) likely to influence the assembling accuracy of the completed vehicle are specified. <P>SOLUTION: In a manufacturing line for vehicles where a plurality of vehicle components and/or constituent members are assembled to each other and the completed vehicle is manufactured, proper assembling positions are measured for each piece of the vehicle components and/or constituent members to prepare the assembling position data, in which each piece of assembling position data is made an explanatory variable while the reference assembling position data to exhibit the assembling accuracies of the final or intermediate completed vehicle is made an object variable, and by making regression analysis based on the explanatory variable and the object variable, the vehicle components and/or constituent members having a high rate of contribution relatively are specified, while the object variable is adjusted to the proper assembling accuracy. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides an assembly of the plurality of parts and the vehicle constituent member in a production line for a vehicle body manufactured by assembling a plurality of parts and a plurality of vehicle constituent members constituted by assembling the parts. The present invention relates to a vehicle assembly accuracy management method for managing accuracy, and in particular, specifies the parts and vehicle components (sub-assy) that affect the assembly accuracy of a completed vehicle, while reducing the assembly accuracy of the vehicle components. The present invention relates to a vehicle assembly accuracy management method capable of realizing stable assembly accuracy management of a completed vehicle by centralized management.

  The conventional assembly accuracy management method for vehicle bodies is to extract any completed vehicle body from the completed vehicle body that is finally assembled with a large number of parts, and measure and manage numerous assembly accuracy checkpoints offline. Was. Such accuracy check points are about 4000 places, and it takes about 1.5 days to measure the assembly accuracy of one vehicle body. On the other hand, all the vehicles (for example, one day) have several vehicle bodies extracted arbitrarily. The number of vehicle bodies produced in Japan is about 1000), so there is a lot of room for improvement in the assembly accuracy management method. In addition, the accuracy of parts in each part of the vehicle body and the assembly accuracy of the sub-assembly are largely affected by the accuracy of multiple parts around it and the assembly accuracy of the sub-assembly. However, it is extremely difficult to specify which part product accuracy or sub-assembly assembly accuracy actually affects the assembly accuracy of the finished vehicle. Based on the subjectivity of the skilled engineer, the original brute was identified.

  Incidentally, Patent Document 1 discloses an invention relating to a vehicle body assembling method. In this assembly method, the accuracy of the dimensions, position, and shape is measured in advance in a single component state for a plurality of welded joint portions at the joint surfaces of a plurality of vehicle body components, and the butt joint surface is matched. And predicting whether or not defects such as interference and gaps will occur, and performing welding joints first from the part where the accuracy of both joint surfaces is perfectly matched and determined that there is no defect It is.

JP 2003-237651 A

  According to the vehicle body assembling method disclosed in Patent Document 1, the variation in accuracy of individual vehicle body components is less likely to affect the variation in accuracy of the entire vehicle body, and the dimensional accuracy of the entire vehicle body can be improved. . However, in the vehicle production line, the assembly order of the vehicle body components is set. Therefore, the method of joining in order from the one that does not have a defect at the time of joining has a different joining order for each vehicle body. There is no denying the decline in yield. Furthermore, in this invention, it is specified which assembly component (or assembly process) has a greater influence on the assembly accuracy checkpoints at multiple locations in the completed vehicle body. I can't. If it is possible to identify which assembly process has a greater effect on the assembly accuracy of the final finished vehicle body when assembling multiple vehicle body components, the assembly process The attachment accuracy can be centrally managed. Moreover, it will also lead to the guarantee of the assembly accuracy of all the units without using the sampling inspection of a small number of units as described above.

  The present invention has been made in view of the above-described problems. When a completed vehicle is manufactured by assembling a plurality of vehicle body components, the assembly accuracy of any component or the assembly accuracy of the completed vehicle is determined. Providing a vehicle assembly accuracy management method that can realize stable assembly accuracy management of a finished vehicle by specifying which vehicle component (sub assembly) assembly accuracy has a greater influence The purpose is to do.

  In order to achieve the above object, a vehicle assembly accuracy management method according to the present invention is a production line for a vehicle body manufactured by assembling a plurality of parts and a plurality of vehicle components formed by assembling the parts. A vehicle assembly accuracy management method for managing assembly accuracy of the plurality of parts and the vehicle component member, wherein each assembly position is measured in the assembly step of the component and the vehicle component member Then, the measurement data is stored as assembly position data, and the assembly position data is used as an explanatory variable, and the vehicle body is a complete or intermediate product formed by assembling the parts and the vehicle components. By using the reference assembly position data representing the assembly accuracy of the objective variable and performing a regression analysis based on the explanatory variable and the objective variable, Characterized in that it comprises a step of identifying a relatively high component or vehicle component contribution ratio with respect to the total finished product or intermediate product of the assembling accuracy.

  The vehicle components such as floor, body side, rear panel, and roof are assembled by welding to produce an intermediate finished product of the vehicle body, and the intermediate finished product is connected to an engine, a drive system member, etc. A fully finished body is produced. Here, each vehicle component is assembled into a so-called small sub-assembly by attaching a large number of parts in the sub-assembly line (sub-assembly process) in the previous stage, and a plurality of small sub-assemblies are assembled to each other. Thus, the vehicle components are sequentially assembled into a large sub-assembly, and the final vehicle body is manufactured.

  The product accuracy (hole position, hole diameter, etc.) of each part of the parts of the first vehicle constituent member (each part) and each vehicle constituent member (small sub-assembly to large sub-assembly) Assembling accuracy and assembling accuracy (allowable tolerance) of the vehicle constituent members are set, and the component parts and the assembling situation at each measurement point are measured, and the measurement data is accumulated. That is, from the measurement data (the product accuracy of the parts themselves and the assembly accuracy of the parts), the measurement data related to the assembly accuracy for each of the plurality of small sub-assemblies, and the plurality of small sub-assemblies Measurement data relating to the assembly accuracy for each medium sub-assembly configured, and further measurement data relating to the assembly accuracy for each large sub-assembly composed of a plurality of medium sub-assemblies are accumulated for each production line.

  Furthermore, even in a completed vehicle composed of a plurality of large subassies (for example, an intermediate finished product of a vehicle body), measurement points for measuring a plurality of assembly accuracy inherent to the vehicle body are set, Each measurement point has a unique assembly tolerance.

  Here, each part of the vehicle body is configured by connecting a plurality of parts and vehicle constituent members to each other. Therefore, the assembly accuracy at each assembly position of the vehicle body is determined by the plurality of parts and the configuration. The assembling accuracy of the members (parts constituting the small sub-assembly, vehicle constituent members from the small sub-assembly to the large sub-assembly) is determined by being related to each other. Therefore, in the present invention, for each assembly step of a plurality of parts and vehicle components, each preset assembly position is measured as assembly position data, and the assembly position data is stored ( Accumulate). Further, the assembly accuracy of a plurality of assembly positions of the completed vehicle is measured and used as reference assembly position data. This reference assembly position data is used as an objective variable, and the assembly position data of a plurality of parts and vehicle components are used as explanatory variables. Data (parts and subassemblies) is to be identified based on regression analysis.

  Here, regression analysis specifies one or a plurality of factors (explanatory variables) that affect the objective variable (there is a correlation) for an arbitrarily set objective variable, and the objective variable is an explanatory variable. This is an evaluation method for obtaining a desired predicted value by expressing with. When multiple explanatory variables are assumed, it is possible to determine the contribution rate to the objective variable for each explanatory variable. By setting a regression equation based on the explanatory variable with a relatively high contribution rate, the actual measurement value Thus, it is possible to obtain an approximate regression equation. It should be noted that the interphase coefficient (multiphase coefficient) that serves as an index for determining whether or not the set regression equation accurately reflects the actual measurement value may be set to an appropriate value (for example, 0.8). Depending on the value of the contribution rate, a single regression equation or multiple regression equation is set for each assembly accuracy checkpoint.

  According to the vehicle assembly accuracy management method of the present invention, a vehicle component (part manufacturing process or assembly process) that can most affect the assembly accuracy at the assembly accuracy measurement point of a completed vehicle, and a set of vehicle components The assembly process can be easily identified, and the product manufacturing accuracy in the component manufacturing process and the assembly accuracy in the assembly process of the vehicle components are centrally managed, so that the assembly accuracy of the completed vehicle can be efficiently and highly accurate. Management can be realized. In addition, when the assembly tolerance exceeds the allowable value at the assembly accuracy measurement point of the finished vehicle, by setting a tighter tolerance for setting in the parts manufacturing process and the assembly process of the vehicle components with a high contribution rate, As a result, the assembly tolerance of the completed vehicle can be easily kept within the allowable value. Furthermore, compared to the conventional method in which the identification method of the original component is different for each engineer, by applying the management method based on the accumulated measurement data and regression analysis, uniform and stable production line assembly management Can be realized.

  In addition, it does not check the assembly accuracy by arbitrarily extracting a small number from the completed vehicle as in the past, but it is not necessary to check all parts or all sub-assemblies in the part manufacturing process and each vehicle component assembly process. By the method of performing the measurement check, it is possible to remove parts and vehicle components that have deviated from the set allowable tolerance from the in-line at that time, and thus it is possible to realize a vehicle production line with extremely high assembly management accuracy. .

  Further, in another embodiment of the vehicle assembly accuracy management method according to the present invention, the measurement of the assembly position is performed by obtaining an image or video of the assembly position, and a tolerance with a pre-stored normal assembly position. The assembly position data is a value based on the tolerance.

  For example, a unique CCD camera is installed in each product manufacturing process and each vehicle component assembly process, and a normal reference position of the measurement site is set for each measurement point in the camera. ing. When an arbitrary measurement point is measured with the camera, the reference position and the actual imaging position (actual position of the measurement site) can be visually recognized from the measurer side. Further, for example, an embodiment in which a two-dimensional tolerance (such as +2 mm in the X direction and −1 mm in the Y direction) is automatically displayed may be used. With this measurement method, the assembly position data at the measurement points set in each component and each sub assembly is measured based on the tolerance, and the assembly position data is accumulated for each assembly process.

  Furthermore, another embodiment of the vehicle assembly accuracy management method according to the present invention relates to the assembly accuracy of the component and / or the assembly accuracy of the vehicle component having a relatively high contribution rate to the objective variable. Multiple manufacturing factors or assembly factors including manufacturing jigs, assembly jigs, manufacturing devices, and assembly devices are used as second explanatory variables, and the assembly accuracy of parts and the assembly accuracy of vehicle components are As a target variable, by centrally managing manufacturing factors or assembly factors that have a relatively high contribution ratio to the second objective variable, the contribution ratio can be reduced with respect to the assembly accuracy of a complete finished product or an intermediate finished product. It is characterized by adjusting high assembly accuracy of parts and / or assembly accuracy of vehicle components to an appropriate assembly accuracy.

  The present invention provides a vehicle component (part manufacturing process and assembly process) and a vehicle component (assembly process) that have a relatively large influence on the assembly accuracy of a completed vehicle. Or various manufacturing factors and assembly factors when assembling the vehicle component, for example, in the manufacturing equipment and assembly equipment such as assembly jigs and welding robots, The manufacturing factor or the assembling factor that has a relatively large influence on the assembling accuracy of the vehicle constituent member is specified. By centrally managing the specified manufacturing factors and assembly factors, adjusting the product accuracy of vehicle components and the assembly accuracy of vehicle components that have a significant impact on the finished vehicle results in the assembly of the finished vehicle. The attachment accuracy can be managed.

  Here, the contribution rate of the vehicle component to the assembly accuracy is evaluated, for example, in three stages (3, 2, and 1 in descending order of contribution rate), and the assembly factor can be easily improved even in the assembly process. Similarly, the degree of the length can be evaluated in three stages (3, 2, and 1 in order of easy improvement), and an assembling factor having a relatively high value obtained by multiplying both can be used as an explanatory variable. When there is one explanatory variable, single regression analysis is used. When there are multiple explanatory variables (when there are explanatory variables with similar contribution ratios), the objective variable (assembly accuracy of vehicle components) is determined by multiple regression analysis. Adjustment can be made within a desired value.

  As can be understood from the above description, according to the vehicle assembly accuracy management method of the present invention, a vehicle component (manufacturing process) that can most affect the assembly accuracy at a plurality of assembly positions set in a completed vehicle. Assembly process) and vehicle component (assembly process) can be easily specified, and product accuracy and assembly accuracy in the parts manufacturing / assembly process and vehicle component assembly process are centrally managed. This makes it possible to realize efficient and highly accurate assembly accuracy management of the completed vehicle. Further, according to the vehicle assembly accuracy management method of the present invention, the vehicle component and vehicle that do not satisfy the desired product accuracy and assembly accuracy from the manufacturing process and assembly process of each component and the assembly process of each vehicle component. By removing the components at any time, the assembly accuracy of almost all completed vehicles can be guaranteed.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a flow in which vehicle components are assembled in order, and FIG. 2 shows that the accuracy of assembling the fender bracket greatly contributes to the accuracy of the clearance between the front hood and the headlamp. The schematic diagrams are respectively shown. FIG. 3 is a schematic diagram showing a situation where measurement points of vehicle constituent members are being measured, and FIG. 4 is an enlarged view of the IV part of FIG. 3 as viewed from the camera. FIG. 5 is a diagram showing the relationship between the assembly tolerance of the fender bracket and the clearance tolerance between the front hood and the headlamp, and FIG. 6 is an explanation determined from the assembly factors of the fender bracket and the assembly factors. Each figure shows a variable. In addition, since the specific calculation formula at the time of regression analysis is well-known, the description is abbreviate | omitted below.

  FIG. 1 shows a sub-assembly process N2 in which an engine compartment 2 is assembled from a small sub-assembly process N1 for manufacturing an apron 1 that is a small sub-assembly, and a large sub-assembly process N3 in which a main body 3 is manufactured from the engine compartment 2. The flow until the completed vehicle body 4 is manufactured is schematically shown. In each sub-assembly process, appropriate measurement points are provided, for example, the assembly accuracy is measured by a CCD camera, and the measurement data is accumulated in the PC placed in each sub-assembly process. The PC in each sub-assembly process is connected to a PC on the central manager side via a network, and centralized management of measurement data is performed. For example, the measurement point in the apron 1 manufactured in the small sub-assembly process N1 is x1, the measurement points in the engine compartment 2 are y1 to y4, the measurement points in the main body 3 are z1 to z5, and in the completed vehicle body 4. Measurement points are w1 to w7. The measurement points set in each sub-assembly process are set as appropriate parts that are considered to affect the measurement points of the completed vehicle body 4, and are not limited to the parts shown in the drawing. In addition to the sub-assembly process, each part (hole position, hole diameter, etc.) of the part is measured not only in the manufacturing booth of the component parts constituting the small sub-assembly.

  In order to show an example, the clearance accuracy between the front hood 51 and the headlamp 52 in the completed vehicle 5 will be taken up based on FIG.

  There are various subassembly assembly factors that are thought to affect the clearance accuracy, such as the cowl subassembly and radiator support reference holes, fender side bracket reference holes, and spring support reference holes. .

  Therefore, a multiple regression analysis is performed for each sub-assembly (small sub-assembly to large sub-assembly), which is considered to affect the clearance accuracy between the front hood 51 and the headlamp 52, with each sub-assembly as an explanatory variable. Here, the objective variable in the multiple regression analysis is the clearance accuracy between the front hood 51 and the headlamp 52, and the explanatory variable is the assembly accuracy at each subassembly (appropriate portion thereof) described above. As a result of the multiple regression analysis, for example, in the embodiment shown in FIG. 2, the contribution rate of the fender bracket portion (x1 location in the figure) to the objective variable has the largest value.

  Therefore, a single regression equation giving the maximum phase: f (x) = a1x1 + a0 (a1 and a0 have been calculated) is calculated. It is confirmed that the obtained multiple correlation coefficient of the single regression equation satisfies an appropriately set value, and the validity of the single regression equation is confirmed.

  FIG. 3 shows a measurement situation of an appropriate part of the subassembly in an arbitrary subassembly process. In the illustrated embodiment, the drilling position of the hole a1 drilled in the sub assembly a is measured. The hole position is measured by the CCD camera 6 in a posture in which the sub assembly a is fixed on the mounting jig 7.

  FIG. 4 shows the state of the screen viewed by the measurer from the CCD camera 6. X1 in the figure is a reference point where the hole a1 should be originally located, and in the illustrated embodiment, it means that the actual hole a1 is at a tolerance position of t2 in the horizontal direction and t1 in the vertical direction. Here, for example, if the circular contour shown in the figure is set as a two-dimensional tolerance, the sub-assembly a can be removed from the inline when the hole a1 is measured at a position deviating from the circular shape.

  FIG. 5 shows a situation where actual measurement data p, p,... Are scattered around the single regression equation. Here, the range from a1 to a2 in the figure: L2 is an allowable tolerance of the fender bracket that was initially set. On the other hand, the range of L1 in the figure is an allowable tolerance range of the gap between the front hood 51 and the headlamp 52. As is apparent from the figure, the tolerance of the gap between the front hood 51 and the headlamp 52 cannot be satisfied with the tolerance of the fender bracket that was initially set. Therefore, based on the calculated single regression equation f (x) and the allowable tolerance range L1, by setting the allowable tolerance of the fender bracket to a range L3 from b1 to b2, the allowable tolerance at an appropriate part of the completed vehicle is set. The subassembly assembly accuracy range that can be satisfied can be determined.

  FIG. 6 is a diagram in which assembling factors that can affect the fender bracket accuracy s1 are extracted for the fender bracket accuracy s1 that is identified as having the greatest influence on the clearance accuracy between the front hood 51 and the headlamp 52. Assembling factors that may affect the fender bracket accuracy s1 include, for example, a welding robot s11 and jig accuracy s12 as illustrated, pallet accuracy and panel accuracy (not illustrated), and variations in transporting the fender bracket. And so on.

  Looking at the welding robot s11 in more detail, the dot order s111, the gun angle s112, the current value / energization time s113, the applied pressure not shown, the tip diameter at the tip, and the like are factors.

  On the other hand, when the jig accuracy s12 is examined in detail, factors such as the clamp play s121, the clamp order s122, the slide equipment play s123, the escape amount of a reference pin diameter (not shown), and the presence or absence of spatter adhesion are factors.

  Therefore, the contribution ratio that each element gives to the fender bracket accuracy s1 is obtained by regression analysis and digitized (in the figure, it is set as 3, 2, 1 in descending order of contribution ratio), and the ease of improvement of each element is further improved. The degree (difficulty level) is quantified in the same way from the rule of thumb (in the figure, it is 3, 2, and 1 in order of easy improvement). The fender bracket accuracy can be managed by performing multiple regression analysis using an element having a relatively large total value obtained by multiplying the contribution value and the difficulty value as an explanatory variable. Since the required fender bracket accuracy tolerance has already been determined in L3 of FIG. 3, the elements of the explanatory variables may be centrally managed so as to be the accuracy tolerance.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

The schematic diagram which showed the flow in which a vehicle structural member is assembled | attached in order. A schematic diagram showing that the assembly accuracy of the fender bracket greatly contributes to the clearance accuracy between the front hood and the headlamp. The schematic diagram which showed the condition which is measuring the measurement point of a vehicle structural member. The enlarged view of the IV section of FIG. 3 seen from the camera. The figure which showed the assembly tolerance of a fender bracket, and the relationship between the clearance tolerance of a front hood and a headlamp. The figure which showed the explanatory variable determined from the assembly factor of a fender bracket, and an assembly factor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Apron, 2 ... Engine compartment, 3 ... Main body, 4 ... Completed vehicle body, 5 ... Completed vehicle, 51 ... Front hood, 52 ... Headlamp, x1, y1-y4, z1-z5, w1-w7 ... Measurement Point, N1 ... Small sub-assembly process, N2 ... Medium sub-assembly process, N3 ... Large sub-assembly process, N4 ... Final assembly process

Claims (3)

In a production line for a vehicle body manufactured by assembling a plurality of parts and a plurality of vehicle constituent members constituted by assembling the parts, the assembly accuracy of the plurality of parts and the vehicle constituent members is managed. A vehicle assembly accuracy management method for
In the step of assembling the part and the vehicle component, the respective assembling positions are measured, the measurement data is stored as assembling position data, the assembling position data is used as an explanatory variable, and the parts and the Regression analysis is performed based on the explanatory variables and the objective variables, with reference assembling position data representing the accuracy of assembling the complete or intermediate finished vehicle body constructed by assembling the vehicle components. Thus, a vehicle assembly accuracy management method comprising a step of identifying a part or a vehicle constituent member having a relatively high contribution rate to the assembly accuracy of a complete product or an intermediate product.   The measurement of the assembly position is to obtain an image or video of the assembly position and calculate a tolerance with a normal assembly position stored in advance, and the assembly position data is a value based on the tolerance. The vehicle assembly accuracy management method according to claim 1, wherein: In the vehicle assembly accuracy management method according to claim 1 or 2,
A plurality of components including a manufacturing jig, an assembling jig, a manufacturing apparatus, and an assembling apparatus with respect to the assembling accuracy of the component and / or the assembling accuracy of the vehicle component having a relatively high contribution rate to the objective variable. The manufacturing factor or assembly factor is the second explanatory variable, the assembly accuracy of the parts and the assembly accuracy of the vehicle components are the second objective variable, and the contribution ratio is relative to the second objective variable. By centrally managing high manufacturing factors or assembly factors, the assembly accuracy of parts and / or vehicle components that have a high contribution rate to the accuracy of assembly of complete or intermediate products is appropriately adjusted. The vehicle assembly accuracy management method is characterized by adjusting the assembly accuracy of the vehicle.

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