JP2007122456A - Product design system, method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a product design system for easily and effectively selecting a design parameter realizing all of a plurality of performance capabilities with consideration given to interaction between the different performance capabilities. <P>SOLUTION: In this product design system for designing a predetermined product while involving computation based on the Taguchi method, a plurality of design parameters relating to a plurality of performance capabilities of the product are set, and a plurality of level values are set to the respective design parameters set by a parameter setting means. The design parameters and the level values are allocated to a predetermined orthogonal table, and according to the orthogonal table, performance capabilities values to the respective level values are calculated for the respective design parameters on the respective performance capabilities. The degrees of the interaction between a plurality of performance capabilities about the respective design parameters are calculated, and display specifications on a factor effect chart, in which the vertical axis shows performance values to the respective level values for each design parameter, are changed so that the calculated degrees of the interaction are reflected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a product design system, method, and program for designing a product in consideration of its predetermined performance.

  As is well known, in an engine, the rotational force applied to the engine crankshaft that varies periodically and the reaction force thereof, and the inertial force of a reciprocating member such as a piston or a connecting rod may remain unbalanced. The engine mount is provided as a component that supports the engine while preventing the vibration of the engine body due to these forces from being transmitted to the vehicle body, and mitigating and attenuating the rolling during acceleration and deceleration and the rolling during turning. . The engine mount is generally an elastic body such as rubber interposed between and fixed to support members attached to the engine and the vehicle body, and absorbs and attenuates vibration due to deformation of the elastic body and internal friction.

  In the design and development of such engine mounts, there are multiple design parameters that need to be matched, and the matching itself becomes complicated when taking into account the case where each design parameter affects each other. Time is needed. In order to perform such tests and evaluations accurately and efficiently, in recent years, it has been known as a technique that can stabilize the quality by suppressing variations from the design stage against fluctuations in product usage conditions, internal deterioration, manufacturing errors, etc. Taguchi method has been widely applied. For example, Japanese Patent Laid-Open No. 2002-322938 (Patent Document 1) discloses performing a test on combustion characteristics of an internal combustion engine using a Taguchi method.

JP 2002-322938 A

  By the way, when Taguchi method is applied to engine mount design and development, first, in order to improve vibration noise performance related to idle vibration, acceleration shock, acceleration running sound, etc. A plurality of design parameters related to the above are set, and a plurality of level values are set for each design parameter. Thereafter, according to the conventional method, after these design parameters and level values are assigned to a predetermined orthogonal table, the performance values for each level value are calculated in an iterative manner for each design parameter, and the calculated performance values are calculated. A factor-effect diagram with the vertical axis as the vertical axis is created, and based on the factor-effect diagram, an optimum level value is selected as each design parameter.

  However, in practice, in each design parameter, for example, if the idle vibration is reduced, the acceleration noise is increased, and if one performance is improved, the other performance is reduced. There is a tendency to have an effect. Therefore, even when a factorial effect diagram that compares performance values for each level value is created, it is difficult to select the level values of design parameters that achieve multiple performances due to variations in the interaction between different performances. There was a problem that it took time.

  The present invention has been made in view of the above technical problem, and a product design system and method capable of easily and efficiently selecting design parameters that achieve a plurality of performances while considering the interaction between the performances. The purpose is to provide a program.

  Therefore, the invention according to claim 1 of the present application is a product design system for designing a predetermined product with an operation based on Taguchi method, parameter setting means for setting a plurality of design parameters related to a plurality of performances of the product, For each design parameter set by the parameter setting means, a level value setting means for setting a plurality of level values, and design parameters and level values respectively set by the parameter setting means and the level value setting means Assigning means for assigning to an orthogonal table, and a performance value calculating means for calculating a performance value for each level value for each design parameter according to the orthogonal table to which design parameters and level values are assigned by the assigning means. And an interaction for calculating the degree of interaction between a plurality of performances related to each design parameter. The degree of interaction calculated by the interaction degree calculation means is reflected in the action specification calculating means and the display specifications on the factor effect diagram for displaying the performance value for each level as the vertical axis for each design parameter. Display specification changing means for changing in this way.

  Further, the invention according to claim 2 of the present application is the invention according to claim 1, wherein the display specification changing means corresponds to the design parameter in which the degree of the interaction between performances exceeds a predetermined threshold. It is characterized in that a setting is made so that the performance value for each level value is not displayed on the effect diagram.

  Furthermore, the invention according to claim 3 of the present application is the invention according to claim 1, wherein the display specification changing means corresponds to the design parameter in which the degree of interaction between the performances exceeds a predetermined threshold. The performance value for each level value on the effect diagram is set to be displayed with a display specification different from the display specification of the performance value corresponding to the other design parameters.

  Furthermore, the invention according to claim 4 of the present application is characterized in that, in the invention according to claim 2 or 3, a threshold value relating to the degree of interaction between performances is set for each combination of the plurality of performances. It is what.

  Furthermore, the invention according to claim 5 of the present application is the invention according to claim 1, wherein the display specification changing means calculates a performance value for each level value for each design parameter, and the performance of the design parameter. It is characterized by weighting with a coefficient that decreases as the degree of inter-action increases.

  Furthermore, the invention according to claim 6 of the present application is the invention according to claim 1, wherein the display specification changing means determines the performance value for each level value for each design parameter, It is characterized by weighting with a coefficient according to the degree.

  Further, the invention according to claim 7 of the present application is the invention according to claim 1, wherein the display specification changing means calculates a performance value for each level value for each design parameter, and the performance of the design parameter. It is characterized by weighting with a product of a coefficient that decreases as the degree of interactivity increases and a coefficient corresponding to the importance of each performance.

  Furthermore, the invention according to claim 8 of the present application is the engine mount according to any one of the inventions according to claims 1 to 7, wherein the product is an engine mount for mounting and supporting the engine with respect to the vehicle. The performance is a performance related to each of idle vibration, acceleration shock, and acceleration running sound.

  The invention according to claim 9 of the present application is the invention according to claim 8, wherein the design parameters are a spring constant, a damping coefficient, and a mounting position of the engine mount. .

  Furthermore, the invention according to claim 10 of the present application is a product design method used in a product design system for designing a predetermined product accompanied by an operation based on Taguchi method, and a design related to a plurality of performances of the product. A parameter setting step for setting a plurality of parameters, a level value setting step for setting a plurality of level values for each set design parameter, and allocation for assigning the set design parameters and level values to a predetermined orthogonal table. A performance value calculating step for calculating a performance value for each of the design parameters for each of the design parameters according to an orthogonal table to which the design parameters and the level values are assigned, and a plurality of performance values for each of the design parameters An interaction degree calculating step for calculating the degree of interaction between the performances of A display specification change step for changing the display specification on the factor effect diagram that displays the performance value for each level as a vertical axis for each meter so as to reflect the degree of interaction calculated in the above interaction degree calculation step. It is characterized by having.

  Further, the invention according to claim 11 of the present application is a parameter setting procedure for setting a plurality of design parameters related to a plurality of performances of the product in a product design system for designing a predetermined product with an operation based on Taguchi method. A level value setting procedure for setting a plurality of level values for each set design parameter, an allocation procedure for assigning the set design parameters and level values to a predetermined orthogonal table, and the design parameters and levels. In accordance with the orthogonal table to which the values are assigned, for each of the above performances, for each design parameter, a performance value calculation procedure for calculating the performance value for each of the above level values, and the degree of interaction between the plurality of performances related to each of the above design parameters The interaction level calculation procedure for calculating the value and the performance value for each level value for each of the above design parameters is displayed as a vertical axis. The display specifications of a factor effect diagram that is a product design program for executing a display specification change procedure for changing to reflect the degree of interaction calculated in the interaction degree calculation procedure.

  According to the invention according to claim 1 of the present application, since the display specifications on the factor effect diagram are changed to reflect the degree of interaction between performances, the quality of each design parameter can be easily distinguished. Thus, a system operator such as a designer can quickly and efficiently select design parameters that achieve a plurality of performances.

  Further, according to the invention according to claim 2 of the present application, the performance value for each level value is not displayed on the factor effect diagram corresponding to the design parameter in which the degree of the interaction between the performances exceeds a predetermined threshold value. The quality of each design parameter can be easily distinguished, and a system operator such as a designer can quickly and efficiently select design parameters that achieve a plurality of performances.

  Furthermore, according to the invention according to claim 3 of the present application, the performance value for each level value on the factor-effect diagram corresponds to a design parameter in which the degree of interaction between the performances exceeds a predetermined threshold. Design values that are different from the display specifications for performance values corresponding to other design parameters can be easily distinguished from each other so that the quality of each design parameter can be easily distinguished. Parameters can be selected quickly and efficiently.

  Furthermore, according to the invention according to claim 4 of the present application, since the threshold value regarding the degree of the interaction between the performances is set for each combination of the plurality of performances, the importance of each performance is taken into consideration, A system operator such as a designer can quickly and efficiently select design parameters that achieve a plurality of performances.

  Furthermore, according to the invention of claim 5 of the present application, the performance value for each level value is weighted with a coefficient that decreases as the degree of interaction between the performances of the design parameter increases. Therefore, the system operator such as a designer can quickly and efficiently select design parameters that achieve a plurality of performances.

  Furthermore, according to the invention according to claim 6 of the present application, the performance value for each level value is weighted by a coefficient according to the importance of each performance, so that the quality of each design parameter can be easily distinguished. This enables a system operator such as a designer to quickly and efficiently select design parameters that achieve a plurality of performances.

  Further, according to the invention according to claim 7 of the present application, the performance value for each level value depends on a coefficient that decreases as the degree of interaction between the performances of the design parameter increases and the importance of each performance. Since weighting is performed by the product with the coefficient, the quality of each design parameter can be easily distinguished, and a system operator such as a designer can quickly and efficiently select design parameters that achieve a plurality of performances. .

  Furthermore, according to the invention according to claim 8 of the present application, design parameters that achieve both performance related to idle vibration, acceleration shock, and acceleration traveling sound can be selected quickly and efficiently.

  Furthermore, according to the invention of claim 9 of the present application, the spring constant, damping coefficient, and mounting position of the engine mount can be quickly and efficiently used as design parameters related to idle vibration, acceleration shock, and acceleration running sound. Can be selected.

  Furthermore, according to the invention according to claim 10 of the present application, since the display specifications on the factor effect diagram are changed to reflect the degree of interaction between performances, the quality of each design parameter is determined. The system operator such as a designer can quickly and efficiently select design parameters that achieve a plurality of performances.

  Further, according to the invention according to claim 11 of the present application, the display specifications on the factor effect diagram are changed so as to reflect the degree of interaction between performances. The system operator such as a designer can quickly and efficiently select design parameters that achieve a plurality of performances.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram showing a configuration of a product design system according to an embodiment of the present invention. In the present embodiment, the product design system 10 is composed of a personal computer that operates based on a predetermined program, and basically the system 10 is configured by executing various instructions based on the predetermined program. CPU 2 for controlling each configuration, ROM 3 for recording a boot program executed when system 10 is started, RAM 4 used as a work buffer area necessary for program execution, OS, application programs, and various data A hard disk ("HD" in the figure) 5 to be stored, an input part 6 such as a keyboard, a display part 7 comprising a liquid crystal display for GUI, and an interface ("I / F ") 8. These components are connected to each other via an internal bus 9.

  The hard disk 5 stores a product design program for designing a product while performing product testing and evaluation as one of application programs. The CPU 2 follows a setting input performed by the user via the input unit 6. In order to appropriately set design parameters related to the performance of the product to be designed, various calculations using a conventionally known Taguchi method are executed based on the product design program.

  In this embodiment, the product design system is configured by a notebook type or all-in-one desktop type personal computer. However, the present invention is not limited to this, and for example, hardware devices corresponding to the respective configurations shown in FIG. They may be provided and connected to each other.

FIGS. 2A to 2C are a side view, a plan view, and a rear view schematically showing an engine support structure on which an engine is supported via an engine mount that is a design target of the product design system 10, respectively. FIG. In this embodiment, a pendulum system is adopted as an engine support system in the engine support structure, and the engine 20 is supported at three points together with the transmission 30 via three engine mounts # 1, # 3, and # 4. .
The “# + number” given to distinguish each engine mount is applicable to all engine support systems including the pendulum system. It represents the engine mount that is set in front of the engine by the support type torque roll shaft system.

  More specifically, in this pendulum system, the engine 20 and the transmission 30 are set to be fixed to a frame body that surrounds the engine 20 and the transmission 30 on or in the vicinity of the extension of the left and right ends of the crankshaft of the engine 20. It is suspended by the mounts # 3 and # 4, and further, the movement in the front-rear direction is suppressed by the engine mount # 1 set to be fixed to the frame body as a stopper on the lower rear side of the engine 20.

  As shown in FIGS. 2A and 2C, the frame body includes a main frame 40, a subframe 50 disposed below the main frame 40, and supporting a front wheel suspension (not shown). It is composed of The main frame 40 is positioned on the left and right sides of the front part of the vehicle body and extends in the longitudinal direction of the vehicle body, and a pair of left and right main side members 40a, 40a, and extends in the vehicle width direction. And a main cross member (not shown) provided so as to connect each other. On the other hand, the sub-frame 50 is positioned below the side members 40a of the left and right main frames 40 at the left and right sides of the front of the vehicle body, and extends in the vehicle width direction with a pair of left and right sub-side members 50a extending in the vehicle body longitudinal direction. And the sub-cross members 50b provided so as to connect the front end portions and the rear end portions of the left and right sub-side members 50a. The main frame 40 and the sub frame 50 are connected by a support 45 interposed between the frames 40 and 50 so as to pass through four intersections of the sub side member 50a and the sub cross member 50b. The support body 45 has a structure that reduces road noise and improves ride comfort and provides a buffering action.

  In the following, an example in which product design processing is performed on the engine mounts # 1, # 3, and # 4 that support the engine 20 and the transmission 30 by the above-described pendulum method by the product design system 10 illustrated in FIG. 1 will be described. . In the present embodiment, Taguchi method is applied when the product design process is performed.

FIG. 3 is a flowchart showing a schematic flow up to the factor effect diagram display step in the product design process executed by the product design system 10. In this process, first, analysis models (engine mounts # 1, # 3, and # 4) are set according to the setting input of the system operator (S11). Next, design parameters related to the vibration and noise performance of engine mounts # 1, # 3 and # 4 are set (S12), and a plurality of (three in this embodiment) level values are set for each design parameter. Is set (S13).
In the present embodiment, three performances are considered as vibration noise performance, that is, performance related to idle vibration, performance related to acceleration shock, and performance related to acceleration running sound. The design parameters and level values set in S12 and S13 will be described later with reference to FIG.

  After step S13, an orthogonal table based on the Taguchi method is selected (S14). In this embodiment, the L54 orthogonal table is selected. Subsequently, the design parameters and level values set in steps S12 and S13 are allocated to the orthogonal table (S15). Thereafter, an analysis of L54 (control factor: design parameter) × L54 (error factor) having an error in all design parameters is executed, and the factor effect is calculated (S16). Specifically, in step S16, based on the vibration noise simulation function incorporated as one function in the product design program, three level values of each design parameter are classified according to the performance related to each of idle vibration, acceleration shock and acceleration traveling sound. A performance value Dji for is calculated. i (= 1, 2, 3) corresponds to three performances, while j (= 1, 2, 3) corresponds to three level values of each design parameter. The performance value Dji is an S / N ratio obtained in an iterative manner with the optimum level value for each time as a new standard value, and is the value on the vertical axis of the factor effect diagram. In the present embodiment, for example, the SN ratio obtained in 10 iterations is used as the performance value.

  Thereafter, analysis of variance is performed to analyze the degree of dispersion between performances having different performance values Dji with respect to the level values of the design parameters (S17). Specifically, in step S17, an inter-performance interaction value P representing a degree of dispersion (a magnitude of the inter-performance interaction) between a plurality of performances of the performance value Dji for each level value is calculated for each design parameter. . This inter-performance interaction value P can be calculated for each performance factor of the Taguchi method, and in this embodiment, an interaction value with respect to the SN ratio, which is one of the performance factors, is represented. Further, a variance analysis table (see FIG. 6) is created based on the analysis result of step S17. After step S17, the factor effect diagram is displayed after correcting the data related to the display specifications of the factor effect diagram as required (S18). Thus, the steps up to the factor effect diagram display step in the product design process are completed.

  FIG. 4 is a table showing a plurality of design parameters related to the vibration noise performance and the level values assigned to each design parameter. In this embodiment, the spring constants in the X and Z directions of the engine mounts # 1, # 3, and # 4 (total of six spring constants according to the number of engine mounts 3 × number of directions 2), engine mounts # 1, # 3, and # 4 Attenuation coefficients in the X and Z directions (a total of six attenuation coefficients by the number of engine mounts 3 × number of directions 2) and mounting positions of engine mounts # 3 and # 4 in the X, Y, and Z directions (number of engine mounts 2 × A total of 18 factors consisting of a total of six attachment positions with three directions) are set as design parameters related to noise and vibration performance, and three level values are set for each design parameter. Yes. The X, Y, and Z directions correspond to the directions added to (a) to (c) of FIG.

  More specifically, the level values 1 to 3 are set so that the level value 2 is a reference value and the level values 1 and 3 are values before and after the reference value. For example, regarding the spring constants in the X and Z directions of the engine mounts # 1, # 3, and # 4, “× 1” is set as the level value 2, whereas the level value 1 and the level value 3 are respectively set. “× 0.7” and “1.3” are set. Further, regarding the attenuation coefficient in the X and Z directions of the engine mounts # 1, # 3, and # 4, “× 1” is set as the level value 2 whereas, as the level value 1 and the level value 3, respectively, “× 0.5” and “1.5” are set. Further, regarding the mounting positions of the engine mounts # 3 and # 4 in the X, Y, and Z directions, “+0 mm” is set as the level value 2, whereas “−0 mm” is set as the level value 1 and the level value 3, respectively. “30 mm” and “+30 mm” are set.

  As shown in FIG. 4, after design parameters and level values associated with each other are assigned to the orthogonal table, the factor effect is calculated as described in S16 of FIG. FIG. 5 is a factor effect diagram created based on the calculation result of the factor effect. Here, the factor effect diagram is related to each of idle vibration, acceleration shock, and acceleration traveling sound with respect to design parameters H to M corresponding to any of the 18 design parameters included in the table shown in FIG. The change of the performance value Dji with respect to the level values 1 to 3 is shown by a line graph in each figure.

  Further, as described in S17 of FIG. 3, based on the calculation result of the factor effect, an analysis of variance for analyzing the magnitude of the interaction between performances is performed, and based on the result of the analysis of variance, the performance interval for each design parameter is analyzed. An analysis of variance table (see FIG. 6) showing the magnitude of the interaction is created. In FIG. 6, the performance interaction value P related to the design parameters H to M is represented as a bar graph corresponding to the factor effect diagram of FIG. 5. The bar graph is displayed so as to increase in proportion as the performance interaction value P increases.

  According to the analysis of variance table shown in FIG. 6, although design parameters having a large interaction between performances can be determined, as long as only the factor-effect diagram shown in FIG. Although it is difficult to select a standard value, in the present embodiment, in step S18 of the flowchart of FIG. 3, the factor effect diagram display data is corrected as necessary, so that the design parameter having a large interaction can be obtained. The display specifications of the factor effect diagram are changed so that the design parameters can be easily distinguished from other design parameters.

  FIG. 7 is a first example of a factor effect diagram based on the corrected factor effect diagram display data in step S18 in FIG. In order to bring about such a factor effect diagram, in step S18 in FIG. 3, a threshold value (shown by a broken line in FIG. 6) is set for the performance interaction value for each design parameter. Data for displaying the factor effect diagram related to the design parameters H to K exceeding the threshold is not displayed.

  FIG. 8 is a second example of the factor effect diagram based on the corrected factor effect diagram display data in step S18 of the flowchart of FIG. In order to bring about such a factor effect diagram, in step S18 in FIG. 3, a threshold value (indicated by a broken line in FIG. 6) is set for the interaction value between performances for each design parameter. For the design parameters H to K whose inter-interaction value exceeds the threshold value, a display using a line graph drawn with a thicker line than the line graph corresponding to the design parameters L and M whose inter-performance interaction value is less than or equal to the threshold value is performed. Is called.

  In addition, although the line graph corresponding to the design parameters H to K whose performance interaction value exceeds the threshold is displayed here as a bold line, the line graph is not limited to this, and the color of the line graph is changed. Other display specifications, such as surrounding the with other lines, are also applicable. A line graph corresponding to design parameters H to K whose performance interaction values exceed the threshold is displayed as usual, while line graphs corresponding to design parameters L and M whose performance interaction values are equal to or less than the threshold. However, it may be displayed after the display specification is changed.

  FIG. 9 is a flowchart of the factor effect diagram display process corresponding to step S18 of FIG. 3 for creating the first or second example of the factor effect diagram shown in FIG. In this process, first, a threshold relating to the interaction between performances is set (S21). Next, any one of the design parameters H to M is selected (S22).

  Subsequently, it is determined whether or not the inter-performance interaction value P related to the selected design parameter is equal to or less than a threshold value (S23). The display parameters such as the design parameters L and M are set (S24). On the other hand, when it is determined that the threshold value is exceeded, they are not displayed as the design parameters H to K in FIGS. Settings for displaying with different display specifications such as using thick lines are made (S25).

  After steps S24 and S25, it is determined whether or not the display determination for all the design parameters H to M has been completed (S26). As a result, if it is determined that the display determination has not been completed, step S22 is performed. Returning to step S4, the subsequent steps are executed for the unprocessed design parameter. On the other hand, if it is determined that the display determination is completed, the process returns to the main flow shown in FIG.

  As described above, the design parameter whose performance interaction value P exceeds the threshold value is not displayed as in the design parameters H to K in FIGS. 7 and 8 or is displayed with different display specifications such as using a thick line. The system operator can easily and efficiently select design parameters that achieve a plurality of performances.

  In the above-described embodiment, the case where the three performances related to the idle vibration, the acceleration shock, and the acceleration traveling sound are taken into consideration has been taken up. However, the present invention is not limited to this, and the present invention is not limited to this. In addition, the present invention is also applicable when only two performances related to the acceleration vibration and the acceleration shock are considered, or only two performances related to the idle vibration and the acceleration traveling sound are considered. In this case, as the threshold for the performance interaction value P, a different value is set for each performance combination.

  For example, when three performances related to idle vibration, acceleration shock, and acceleration running sound are considered, 10 is set as a threshold, and two performances related to idle vibration and acceleration shock are When considered, 8 is set as the threshold, and when two performances related to idle vibration and acceleration traveling sound are considered, 5 is set as the threshold. Such setting is performed, for example, by reflecting the degree of interaction between the performances.

FIG. 10 is a third example of the factor effect diagram based on the corrected factor effect diagram display data in step S18 in FIG. In order to bring about such a factor effect diagram, in step S18 in FIG. 3, basically, the larger the interaction value P between performances, the performance for each level value corresponding to the vertical axis of the factor effect diagram for each performance. Correction is performed so that the value Dji becomes smaller. Specifically, correction is performed by integrating the reciprocal of the inter-performance interaction value P with respect to the performance value Dji. In the factor / effect diagram shown in FIG. 10, the variation in the performance value Dji is smaller with respect to the design parameter (for example, the design parameter I or K) having a large interaction value P than the factor / effect diagram before correction shown in FIG. It can be easily visually recognized.
As a correction that the performance value Dji for each level value corresponding to the vertical axis of the factor-effect diagram relating to each performance becomes smaller as the performance interaction value P becomes larger, a fixed value K for the performance value Dji is used. And a correction for integrating the deviation (K−P) between the performance interaction value P and the performance may be performed.

  FIG. 11 is a flowchart of the factor effect diagram display process corresponding to step S18 of FIG. 3 for creating the third example of the factor effect diagram shown in FIG. In this process, first, any one of the design parameters H to M is selected (S31). Next, the performance value Dji already calculated for each level value of the selected design parameter is read (S32). Further, the performance interaction value P already calculated for the selected design parameter is read (S33).

  Subsequently, the performance value Dji is corrected by integrating the reciprocal 1 / P of the performance interaction value P (S34). Then, the corrected performance value Dji is set as factor effect diagram display data (S35). Thereafter, it is determined whether or not the display determination for all the design parameters H to M has been completed (S36). As a result, if it is determined that the display determination has not been completed, the process returns to step S31 and thereafter. The above steps are executed for the unprocessed design parameters, and when it is determined that the display determination is completed, the process returns to the main flow shown in FIG.

  As described above, since the correction for accumulating the reciprocal of the inter-performance interaction value P is performed on the performance value Dji, in the factor effect diagram after correction (see FIG. 10), the factor effect diagram before correction (FIG. 5), it is easy to visually recognize that the variation of the performance value Dji is small with respect to the design parameter having a large interaction value P, and the system operator can select a design parameter that achieves a plurality of performances. You can select easily and efficiently.

  FIG. 12 is a fourth example of the factor effect diagram based on the corrected factor effect diagram display data in step S18 in FIG. In order to bring about such a factor effect diagram, in step S18 in FIG. 3, as in the case of creating the third example of the factor effect diagram, as the inter-performance interaction value P is larger, the factor effect diagram relating to each performance. In addition to correction so that the performance value Dji corresponding to each level value corresponding to the vertical axis of FIG. 4 becomes small, the performance value Dji is weighted in consideration of the importance of each performance.

  Specifically, a weighting coefficient γ is set in advance for each performance. For example, a weighting coefficient γ1 = 2.0 is set for performance related to idle vibration, and weighting is performed for performance related to acceleration shock. The coefficient γ2 = 1.5 is set, and the weighting coefficient γ3 = 1.0 is set for the performance related to the acceleration traveling sound. In the factor / effect diagram shown in FIG. 12, the variation in the performance value Dji is smaller with respect to the design parameter (for example, the design parameter I or K) having a larger interaction value P than the factor / effect diagram before correction shown in FIG. In addition, it can be easily recognized that the performance value Dji is large with respect to the importance having high importance.

  FIG. 13 is a flowchart of the factor effect diagram display process corresponding to step S18 of FIG. 3 for creating the fourth example of the factor effect diagram shown in FIG. In this process, first, any one of the design parameters H to M is selected (S41). Next, the performance value Dji already calculated for each level value of the selected design parameter is read (S42). Further, the performance interaction value P already calculated for the selected design parameter is read (S43). Subsequently, the performance value Dji is corrected by integrating the reciprocal 1 / P of the inter-performance interaction value P (S44).

  Thereafter, the weighting coefficient γj (j = 1 to 3) for each performance is read (S45). Then, Dji after the correction in step S44 is further corrected by adding γj (S46). That is, according to steps S44 and S45, the performance value Dji is weighted by the product of the inverse 1 / P of the performance interaction value P and the weighting coefficient γj for each performance. Then, the performance value Dji after correction in steps S44 and S46 is set as the factor effect diagram display data (S47).

  Subsequently, it is determined whether or not the display determination for all the design parameters H to M has been completed (S48). As a result, if it is determined that the display determination has not been completed, the process returns to step S41. Subsequent steps are executed for the unprocessed design parameters, and when it is determined that the display determination is finished, the process returns to the main flow shown in FIG.

  As described above, since the correction is performed by integrating the reciprocal 1 / P of the inter-performance interaction value P and the weighting coefficient γj for each performance with respect to the performance value Dji, the factor effect diagram after correction (see FIG. 12). In FIG. 5, compared to the factor effect diagram before correction (see FIG. 5), regarding the design parameter having a large interaction value P, the variation in the performance value Dji is small, and the importance level is high. It is easily visible that the performance value Dji is large, and the system operator can easily and efficiently select design parameters that achieve a plurality of performances.

  In this embodiment, the performance value Dji is weighted by the product of the reciprocal 1 / P of the performance interaction value P and the weighting coefficient γj for each performance. However, the performance value Dji is not limited to this. On the other hand, the performance value Dji may be weighted simply by integrating the weighting coefficient γj for each performance.

  The product design process and the factor effect diagram display process shown in FIGS. 3, 9, 11 and 13 are executed by reading a program stored in the ROM 3 or the hard disk 5 included in the system 10. 10 may be incorporated in advance as part of a program that is the basis of control by the CPU 2, or as a product design program, an optical disk such as a CD-ROM or DVD-ROM or an external disk such as a floppy (registered trademark) disk. It may be installed in the system 10 by using a recording medium or downloaded via a network and additionally stored in the hard disk 5.

  It should be noted that the present invention is not limited to the illustrated embodiments, and it goes without saying that various improvements and design changes can be made without departing from the scope of the present invention.

  The present invention is applicable to any product design system that can execute a process including a step of displaying a factor-effect diagram based on the Taguchi method.

It is a figure showing the structure of the product design system which concerns on embodiment of this invention. (A) It is a side view of an engine mount. (B) It is a top view of an engine mount. (C) It is a rear view of an engine mount. It is a flowchart about the product design process performed by the said product design system. It is a table showing a plurality of design parameters related to the vibration and noise performance of the product and three level values assigned to each design parameter. It is a factor effect figure created based on the calculation result of the factor effect in Step S16 in FIG. It is an analysis of variance table showing the degree of interaction between performances regarding each design parameter. FIG. 6 is a first example of a factor effect diagram based on the corrected factor effect diagram display data in step S18 in FIG. 3; FIG. 10 is a second example of the factor effect diagram based on the corrected factor effect diagram display data in step S18 of the flowchart of FIG. 3; FIG. 9 is a flowchart of a factor effect diagram display process corresponding to step S18 of FIG. 3 for creating the first or second example of the factor effect diagram shown in FIG. It is a 3rd example of the factor effect figure based on the data for the corrected factor effect figure display in step S18 in FIG. It is a flowchart about the factor effect figure display process corresponding to step S18 of FIG. 3 for producing the 3rd example of the factor effect figure shown in FIG. It is a 4th example of the factor effect figure based on the data for the corrected factor effect figure display in step S18 in FIG. 13 is a flowchart of a factor effect diagram display process corresponding to step S18 of FIG. 3 for creating a fourth example of the factor effect diagram shown in FIG.

Explanation of symbols

2 ... CPU, 3 ... ROM, 4 ... RAM, 5 ... HD, 6 ... input unit, 7 ... display unit, 8 ... I / F, 10 ... product design system, # 1, # 3, # 4 ... engine mount, 20 ... Engine, 30 ... Transmission.

Claims (11)

In a product design system that designs a given product with operations based on Taguchi method,
Parameter setting means for setting a plurality of design parameters related to a plurality of performances of the product;
Level value setting means for setting a plurality of level values for each design parameter set by the parameter setting means,
Allocating means for allocating design parameters and level values respectively set by the parameter setting means and the level value setting means to a predetermined orthogonal table;
According to the orthogonal table in which the design parameters and the level values are allocated by the allocation unit, for each performance, a performance value calculation unit that calculates a performance value for each level value for each design parameter;
An interaction degree calculating means for calculating the degree of interaction between a plurality of performances related to each of the design parameters;
Display specifications for changing the display specifications on the factor-effect diagram that displays the performance value for each level as the vertical axis for each design parameter so as to reflect the degree of interaction calculated by the interaction degree calculation means And a product design system. The display specification changing means is configured to perform a setting so that the performance value for each level value is not displayed on the factor effect diagram corresponding to a design parameter in which the degree of interaction between the performances exceeds a predetermined threshold value. The product design system according to claim 1. The display specification changing means corresponds to a design parameter in which the degree of interaction between performances exceeds a predetermined threshold, and the performance value for each level value on the factor effect diagram corresponds to other design parameters. The product design system according to claim 1, wherein the display is performed with a display specification different from the display specification of the performance value. 4. The product design system according to claim 2, wherein a threshold related to the degree of interaction between performances is set for each combination of the plurality of performances. 5. 2. The product design system according to claim 1, wherein the display specification changing means weights the performance value for each level value with a coefficient that decreases as the degree of interaction between the performances of the design parameters increases. 2. The product design system according to claim 1, wherein the display specification changing unit weights the performance value for each level value with a coefficient corresponding to the importance of each performance for each of the design parameters. For each design parameter, the display specification changing means includes a coefficient that decreases as the degree of interaction between the performances of the design parameter increases and a coefficient corresponding to the importance of each performance. The product design system according to claim 1, wherein the product design system is weighted by a product. The product is an engine mount for attaching and supporting an engine to a vehicle, and the performance is related to idle vibration, acceleration shock, and acceleration running sound. The product design system according to any one of 1 to 7. 9. The engine mount design system according to claim 8, wherein the design parameters are a spring constant, a damping coefficient, and a mounting position of the engine mount. In a product design method used in a product design system that designs a predetermined product with operations based on Taguchi method,
A parameter setting step for setting a plurality of design parameters related to a plurality of performances of the product;
A standard value setting step for setting a plurality of standard values for each set design parameter;
An assigning step for assigning each set design parameter and level value to a predetermined orthogonal table;
According to the orthogonal table to which the design parameter and the level value are assigned, a performance value calculation step for calculating a performance value for each of the level values for each of the design parameters,
An interaction degree calculating step for calculating the degree of interaction between a plurality of performances related to each design parameter;
A display specification that changes the display specifications on the factor-effect diagram that displays the performance value for each level as the vertical axis for each design parameter so as to reflect the degree of interaction calculated in the interaction degree calculation step. A product design method comprising: a changing step. A product design system that designs predetermined products with operations based on Taguchi method.
A parameter setting procedure for setting a plurality of design parameters related to a plurality of performances of the above products;
A standard value setting procedure for setting a plurality of standard values for each set design parameter,
An allocation procedure for assigning the set design parameters and level values to a predetermined orthogonal table;
According to the orthogonal table to which the design parameters and the level values are assigned, for each performance, a performance value calculation procedure for calculating a performance value for each level value for each design parameter;
An interaction degree calculation procedure for calculating the degree of interaction between a plurality of performances related to each of the design parameters;
Display specifications for changing the display specifications on the factor effect diagram that displays the performance value for each level as the vertical axis for each design parameter so as to reflect the degree of interaction calculated in the above interaction degree calculation procedure A product design program that executes the change procedure.

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