JP4809740B2 - Method for simulating air trajectory in workpiece to be immersed and computer-executable program for executing this simulation method - Google Patents

Description

  The present invention relates to a method for simulating an air trajectory in an object to be immersed for simulating a trajectory through which air in an air pool generated in the object to be immersed escapes, and a computer-executable program for executing the simulation method.

  The surface of the object to be immersed such as a semiconductor as an electronic component or the body of a vehicle is immersed in a treatment tank filled with a metal solution, an electrodeposition solution, etc., so that the surface is subjected to plating treatment or coating treatment. Yes. According to such a surface treatment method, the plating layer thickness and the coating film thickness formed on the surface of the object to be immersed are made substantially uniform, or the same surface treatment is applied to the welded portion of the object to be immersed. There are advantages such as being able to do. On the other hand, for example, in the case of a body body, a plurality of recesses are formed on the inner surface of the hood, the inner surface of the roof, the lower surface of the floor, etc. in the object to be immersed in a complicated shape, so that these recesses become an air pocket called an air pocket. In the state where the air in the air pool remains, there is a disadvantage that the surface treatment cannot be performed on the portion.

Therefore, a discharge path for exhausting air into the atmosphere is formed in advance in the object to be immersed so that air accumulation does not occur in the object to be immersed, and the air is discharged into the atmosphere through this discharge path. In other words, surface treatment can be performed on the entire surface of the object to be dipped (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 10-045037

  By the way, the trajectory through which air in the air pool generated in the object to be immersed escapes can be simulated by a well-known analysis method using a free surface. However, conventionally, in performing such an analysis, the object to be immersed is analyzed by dividing it into three-dimensional elements, so that the shape of the object to be immersed is complex, for example, as in a vehicle body. In the case of a complicated shape, the analysis process has to be complicated, and there is a problem that it takes time to simulate the trajectory through which the air in the air pocket escapes.

  SUMMARY OF THE INVENTION An object of the present invention is to simplify an analysis process, thereby efficiently simulating a trajectory through which air in an air pool generated in the object to be immersed escapes, and a simulation method of the air trajectory in the object to be immersed and this simulation An object of the present invention is to provide a program executable by a computer executing a method.

The simulation method of the air trajectory in the object to be submerged according to the present invention is a simulation method of the air trajectory in the object to be submerged that simulates the trajectory through which air in the air pool generated in the object to be submerged escapes using a fluid analysis device. A minimum element setting step of setting the element at the lowest position in the direction of gravity as the lowest element based on the numerical calculation model of the object to be immersed divided into a plurality of elements by the control unit of the fluid analyzing apparatus ; A reference node setting step for setting a node at the highest position in the lowest element as a reference node; an adjacent element setting step for setting a plurality of elements including the reference node and adjacent to the lowest element as adjacent elements; and the reference A gradient derivation step for deriving the gradient of the line segment connecting the node and each node at the highest position in each adjacent element. And the node storage step for storing the nodes of the line segment having the steepest slope, and the adjacent element including the node stored in the node storage step as a new lowest element in the next step And after repeating the above steps until the number of adjacent elements including the new reference node of the lowest element is equal to or less than a predetermined number, or the gradient between the node of the adjacent element and the new reference node is negative, the node the line segment connecting the nodes stored in the storage step, characterized that you run the air trajectory display step of displaying to the outside as the air track.

The simulation method of the air trajectory in the object to be submerged according to the present invention is a simulation method of the air trajectory in the object to be submerged that simulates the trajectory through which air in the air pool generated in the object to be submerged escapes using a fluid analysis device. A minimum element setting step of setting the element at the lowest position in the direction of gravity as the lowest element based on the numerical calculation model of the object to be immersed divided into a plurality of elements by the control unit of the fluid analyzing apparatus ; A reference barycentric point setting step for setting a barycentric point of the lowest element as a reference barycentric point; an adjacent element setting step for setting a plurality of adjacent elements including a node at the highest position in the lowest element as an adjacent element; A gradient derivation step for deriving a gradient of a line segment connecting a reference centroid point and each centroid point of each adjacent element; and In comparison, the center-of-gravity point storing step for storing the center-of-gravity point of the line segment having the steepest slope, and the adjacent element including the center-of-gravity point stored in the center-of-gravity point storing step is set as a new minimum element in the next step, After repeating the above steps until the number of adjacent elements including the new reference centroid point of the lowest element is equal to or less than a predetermined number, or the gradient between the centroid point of the adjacent element and the new reference centroid point is negative, a line segment connecting the center of gravity that is stored in the center-of-gravity point storing step, characterized that you run the air trajectory display step of displaying to the outside as the air track.

  The method for simulating the air trajectory in the object to be immersed according to the present invention is characterized in that the object to be immersed is a vehicle body.

  The computer-executable program for executing the method for simulating the air trajectory in the object to be immersed of the present invention simulates the trajectory through which the air in the air pool generated in the object to be immersed escapes. A computer-executable program for executing the method, and a minimum element setting for setting the element at the lowest position in the direction of gravity as the lowest element based on the numerical calculation model of the object to be immersed divided into a plurality of elements A reference node setting step for setting a node at the highest position in the lowest element as a reference node; an adjacent element setting step for setting a plurality of elements including the reference node and adjacent to the lowest element as adjacent elements; The slope of the line segment connecting the reference node and each node at the highest position in each adjacent element The gradient deriving step for deriving each of the above, the node storing step for comparing the respective gradients and storing the node of the line segment having the steepest slope, and the adjacent element including the node stored in the node storing step are A new minimum element in each step is used, and each step is performed until the number of adjacent elements including the new reference node of the minimum element is equal to or less than a predetermined number, or the gradient between the node of the adjacent element and the new reference node becomes negative. And an air trajectory display step of displaying the line segment connecting the nodes stored in the node storing step to the outside as an air trajectory after being repeatedly performed.

  The computer-executable program for executing the method for simulating the air trajectory in the object to be immersed of the present invention simulates the trajectory through which the air in the air pool generated in the object to be immersed escapes. A computer-executable program for executing the method, and a minimum element setting for setting the element at the lowest position in the direction of gravity as the lowest element based on the numerical calculation model of the object to be immersed divided into a plurality of elements A reference centroid point setting step for setting a centroid point of the lowest element as a reference centroid point; an adjacent element setting step for setting adjacent elements including a node at the highest position in the lowest element as an adjacent element; , Respectively, to derive gradients of line segments connecting the reference centroid points and the centroid points of the adjacent elements. The gradient derivation step, the respective gradients are compared, the centroid point storage step of storing the centroid point of the line segment having the steepest gradient, and the adjacent element including the centroid point stored in the centroid point storage step As a new minimum element in each step, the number of adjacent elements including the new reference centroid point of the minimum element is equal to or less than a predetermined number, or until the gradient between the centroid point of the adjacent element and the new reference centroid point becomes negative An air trajectory display step of displaying a line segment connecting the barycentric points stored in the barycentric point storing step to the outside as an air trajectory after each step is repeatedly performed.

  The computer-executable program for executing the simulation method of the air trajectory in the object to be immersed according to the present invention is characterized in that the object to be immersed is a vehicle body.

According to the simulation method of the air trajectory in the object to be submerged according to the present invention, the control unit of the fluid analysis apparatus divides the numerical calculation model of the object to be submerged into the lowest element and the two-dimensional element of the adjacent element. Compares the slopes of the line segments connecting the reference node at the highest position in the gravity direction of the element and the nodes at the highest position in the gravity direction of multiple adjacent elements, and determines the node that forms the steepest line segment. to simulate one after another that the trajectory of the air is formed toward can Rukoto display the air track as a result to the outside.

  Therefore, compared with the case where analysis processing is performed by dividing into three-dimensional elements, the calculation time from the initial state to the convergence state for the analysis processing can be shortened, and thus the development time of the treatment object to be immersed can be reduced. The manufacturing cost can be reduced by shortening.

According to the air trajectory simulation method of the object to be immersed according to the present invention, the control unit of the fluid analysis device compares the slopes of the line segments connecting the reference node of the lowest element and the nodes of a plurality of adjacent elements. Instead of simulating, the steepest line segment is formed by comparing and simulating the gradients of the line segments connecting the reference centroid point of the lowest element and the centroid points of a plurality of adjacent elements. by simulating that one after another trajectory of the air towards the center of gravity is formed, it is Rukoto display the air track as a result to the outside.

  According to the method for simulating the air trajectory in the object to be immersed according to the present invention, the object to be immersed can be the vehicle body, and in this case, the air trajectory in the body body having a complicated shape can be simulated. For example, it is possible to determine the end point of the predicted air trajectory as an air reservoir, and to form an escape hole in the part to allow air to escape to the outside, and to secure rigidity by optimizing the number of escape holes. In addition, it is possible to efficiently design a vehicle body that can be reduced in weight.

  According to the computer-executable program for executing each simulation method of the present invention, the computer divides the numerical calculation model of the object to be immersed into the two-dimensional elements of the lowest element and the adjacent element, and Each gradient of the line segment connecting the reference node at the highest position in the gravity direction and each node at the highest position in the gravity direction of multiple adjacent elements, or the reference centroid point of the lowest element and the centroid points of multiple adjacent elements Compare the slopes of the line segments that connect to each other, and simulate the formation of air trajectories one after another toward the nodes or centroids that form the steepest line segments, and the resulting air trajectories Can be displayed externally.

  Therefore, compared with the case where analysis processing is performed by dividing into three-dimensional elements, the calculation time from the initial state of the analysis processing to the convergence state can be shortened, and consequently the development time of the object to be immersed is reduced. The manufacturing cost can be reduced by shortening.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a fluid analyzing apparatus for executing a simulation method of an air trajectory in an object to be immersed according to the present invention, FIG. 2 is an explanatory view for explaining a painting line of a vehicle body, and FIG. FIG. 4 is a perspective view showing a numerical calculation model of the floor panel, FIG. 4 is a flowchart for explaining the operation of the simulation method of the air trajectory in the object to be immersed according to the first embodiment, and FIGS. (C) is a schematic diagram showing a part of the divided two-dimensional elements.

  As shown in FIG. 1, a fluid analysis apparatus 10 that executes a simulation method of an air trajectory in an object to be immersed according to the present invention includes a keyboard 11 for inputting analysis conditions of the object to be immersed (not shown), Display 12 for displaying analysis processing results, HDD (hard disk drive) 13 for storing various data of the object to be immersed, and FDD (flexible disk drive) for storing analysis processing results in FD (flexible disk) 14).

  The fluid analysis apparatus 10 further includes a control unit 18 including a CPU 15, ROM 16 and RAM 17, a keyboard controller 19 of the keyboard 11, a display controller 20 of the display 12, a disk controller 21 of the HDD 13 and the FDD 14, and a fluid analysis apparatus. A network interface controller 23 for connecting 10 to the network 22 is provided, and these can communicate with each other via a system bus 24.

  The CPU 15 constituting the control unit 18 executes the software stored in the ROM 16 and the HDD 13 or the software supplied from the FDD 14 so as to comprehensively control various components connected to the system bus 24. It has become. That is, the CPU 15 reads out software from the ROM 16, HDD 13, or FDD 14 according to a predetermined processing sequence, and executes the program to perform control for realizing the operation shown in FIG. 4.

  CPU15 reads the various data of the to-be-immersed processing object used as analysis object from HDD13, and constructs the two-dimensional numerical calculation model divided | segmented into several elements from this read-out various data. Further, the CPU 15 performs the setting of the minimum elements, adjacent elements and nodes necessary for realizing the operation shown in FIG. 4 based on the constructed numerical calculation model, and the calculation of the gradient for finally determining the air trajectory. To do.

  The RAM 17 constituting the control unit 18 functions as a main memory or work area for the CPU 15. The keyboard controller 19 controls input signals from input means such as the keyboard 11 and a pointing device (not shown), and the display controller 20 controls display on the display 12. The disk controller 21 controls access to the HDD 13 and the FDD 14 that store or read a boot program, various applications, editing files, user files, network management programs, and the like. The network interface controller 23 transmits and receives data to and from other devices (not shown) on the network 22.

  The method for simulating an air trajectory in the object to be immersed according to the first embodiment simulates a trajectory through which air in an air reservoir generated in the vehicle body escapes during electrodeposition coating of the vehicle body such as a passenger car. First, a painting line for a vehicle body will be described with reference to FIG.

  As shown in FIG. 2, the vehicle body 30 as the object to be immersed is formed by joining a plurality of vehicle body panels (not shown) made up of floor panels, side panels, roof panels, and the like by spot welding or the like. Yes. The vehicle body 30 is transported in a substantially horizontal direction on the coating line 33 while being hung on a hanger 32 of a transport device 31.

  A pre-processing line (not shown) is provided in the front stage of the coating line 33 of the conveying device 31. In this pre-processing line, the body 30 is subjected to hot water washing and degreasing as a pre-treatment for electrodeposition coating. , Water washing, surface conditioning, film formation, water washing, and drying are successively performed in this order. After finishing the treatment in the pretreatment line, the vehicle body 30 moves to the coating line 33 and descends toward the electrodeposition tank (treatment tank) 34 and is substantially immersed in the electrodeposition solution 35. It is designed to move horizontally. Under this state, a predetermined thickness of voltage is applied to the body 30 and electrodes (not shown) in the electrodeposition tank 34 to deposit a coating film having a predetermined thickness on the surface of the body 30. Can be made. Thereafter, the vehicle body 30 is pulled up from the electrodeposition tank 34 by the transfer device 31 and the excess electrodeposition solution 35 adhering to the vehicle body 30 without being electrodeposited is removed by washing or the like.

  Next, the air trajectory simulation method for the object to be immersed according to the first embodiment will be described in detail. In the first embodiment, the finite element method is used as an analysis method, and the analysis is performed on the floor panel constituting the vehicle body 30 as an analysis target.

  3 shows a numerical calculation model of the floor panel 40 in the vehicle body 30, and the control unit 18 of the fluid analysis apparatus 10 applies the plurality of elements 41 (see FIG. 3) to the surface of the floor panel 40 of FIG. 3. A two-dimensional numerical calculation model for constructing various numerical calculations is constructed by dividing it into a part (shown in a broken line circle). However, in constructing a two-dimensional numerical calculation model, for example, a two-dimensional numerical calculation model used in a collision deformation simulation of the vehicle body 30 can be used.

  The control unit 18 constructs a two-dimensional numerical calculation model for a plurality of vehicle body panels such as a side panel and a roof panel in addition to the floor panel 40, and all elements based on the constructed numerical calculation model. The attribute of is set to air (AIR). Thus, by setting the attribute of all the elements to air, a state in which the periphery of various panels before the vehicle body 30 is put into the electrodeposition tank 34 is filled with air is simulated.

  As shown in the flowchart of FIG. 4, when power is supplied to the fluid analysis device 10 and power is supplied to the control unit 18, initial setting of the control unit 18 is performed and analysis processing is performed from the HDD 13 or the like to the RAM 17. The program for executing the simulation method of the air trajectory in the object to be immersed according to the present invention is executed (step S1). Next, the operator inputs a part number to be analyzed, for example, a part number (No_i) corresponding to the floor panel 40 to be analyzed via the keyboard 11 (step S2).

  In step S3, in order to accurately simulate the flow of air in consideration of the charging angle of the floor panel 40 to the electrodeposition tank 34, the gravity direction G (for example, 45 ° diagonally downward to the right of the charging angle) is set. Input from the keyboard 11. Then, the gravity direction G is added to the two-dimensional numerical calculation model of the floor panel 40 and read from the HDD 13 or the like into the RAM 17 (step S4).

  In step S5, the lowest element (Elem_j) at the lowest position in the gravity direction G is set from among all the elements 41 of the floor panel 40. Here, the plurality of elements 41 are formed by a rectangular plane as shown in FIG. 5A, and four nodes are provided at the corners of each element 41. Each of these nodes is provided with coordinate data in the XYZ axis directions, and based on this coordinate data, the position of each node is determined from a predetermined reference position.

  After setting the lowest element (Elem_j), that is, setting the lowest element of No. (14) (Elem14 of the cross-hatching part) as shown in Fig. 5 (a), the lowest element (Elem14) is set to the start of the air trajectory. Stored in the RAM 17 as a point. Thus, the process of step S5 for setting the lowest element (Elem14) constitutes the lowest element setting step in the present invention.

  In step S6, the Z coordinate data is selected from the nodes of the lowest element (Elem14) stored in the RAM 17 in step S5, that is, the four nodes No. (42), (7), (41) and (38). Is set to the highest node (Node_j_h) at the highest position in the gravity direction G. Here, the highest node (Node_j_h) is the node (Node38) of No. (38) as shown in FIG. 5A, and this highest node (Node38) is determined as the reference node in the direction of air. Stored in the RAM 17. Thus, the process of step S6 which sets the highest node (Node38) of the lowest element (Elem14) set immediately after the execution of the program as the reference node constitutes the reference node setting step in the present invention.

  In step S7, a plurality of adjacent elements (Elem_k) adjacent to the lowest element (Elem14) set in step S5 are set, and the number of the adjacent elements (Elem_k) is extracted. Here, the plurality of adjacent elements (Elem_k) includes the reference node (Node 38). In this case, as shown in the hatched portion of FIG. 5A, No. (10), (12) and (15 ) Are set as adjacent elements (Elem_k), and the number “3” is extracted. As described above, the process of step S7 for setting the adjacent elements (Elem12), (Elem10) and (Elem15) including the reference node (Node38) and extracting the number “3” is the adjacent element setting step in the present invention. It is composed.

  In step S8, the adjacent elements (Elem12), (Elem10) and (Elem15) extracted in step S7 are counted as “K = 1” in order to perform analysis processing in this order, and the analysis target is set as the adjacent element (Elem12). Set. After that, the set adjacent element (Elem_1), that is, the highest node (Node_1_h) in the gravity direction G of the adjacent element (Elem12) is set based on the Z coordinate data (step S9). Here, the node of No. (39) shown in FIG. 5A is set as the highest node (Node_1_h).

  In step S10, the slope (Tan_1_j) of the line segment connecting the reference node (Node38) that becomes the highest node (Node_j_h) set in step S6 and the highest node (Node39) that becomes the highest node (Node_1_h) set in step S9. Is derived by a predetermined arithmetic expression. Here, the gradient of the line connecting the reference node (Node38) and the highest node (Node39), that is, the gradient (Tan12) of the adjacent element (Elem12) is the coordinate between the reference node (Node38) and the highest node (Node39) It is derived according to the following formula (1) based on the data. Thus, the process of step S10 for deriving the gradient (Tan_1_j) constitutes the gradient deriving step in the present invention.

  The gradient (Tan12) derived from equation (1) is 0.2052, and the numerical data of this gradient (Tan12) is the steepest numerical data (Tan_max) at the present time, and the highest node forming the gradient (Tan12) (Node39) is temporarily stored in the RAM 17 as the highest node (Node_max) (step S11).

  Next, the process proceeds to step S12. In this step S12, among the adjacent elements (Elem12), (Elem10), and (Elem15) extracted in step S7, in order to perform the analysis processing of the next adjacent element (Elem10), Count as “K = k + 1” and set to the adjacent element (Elem10). After that, the set adjacent element (Elem_2), that is, the highest node (Node_2_h) with respect to the gravity direction G of the adjacent element (Elem10) is set (step S13). Here, the node No. (58) is set as the highest node (Node_2_h).

  In step S14, the gradient (Tan_2_j) of the line segment connecting the reference node (Node38) set in step S6 and the highest node (Node58) which is the highest node (Node_2_h) set in step S13 is expressed by the above equation (1). Similarly, it derives by Thus, the gradient derivation step of the present invention is also configured in the process of step S14 for deriving the gradient (Tan_2_j).

  The gradient (Tan10) as the gradient (Tan_2_j) is 0.1194. In the subsequent step S15, the numerical data of the gradient (Tan10) is compared with the numerical data of the gradient (Tan12) stored in the RAM 17 in step S11. If the comparison result of the numerical data in step S15 is (Tan_2_j) equal to or greater than (Tan_max), the process proceeds to step S16 as yes, and if (Tan_2_j) is equal to or less than (Tan_max), the process proceeds to step S17 as no. In step S16, assuming that the gradient (Tan_2_j) is the steepest gradient, the numerical data (Tan_max) of the gradient (Tan_1_j) stored in the RAM 17 is rewritten with the numerical data of the gradient (Tan_2_j), and the gradient (Tan_2_j) is formed. The highest node (Node_2_h) to be used is the highest node (Node_max). In this embodiment, since (Tan_2_j) ≦ (Tan_max), the process proceeds to step S17.

  In step S17, whether or not all of the adjacent elements (Elem12), (Elem10), and (Elem15) extracted in step S7 have been analyzed, that is, the number of the extracted adjacent elements (Elem_k) is “3”. It is determined whether (Kmax) has been reached. Then, if analysis processing of all adjacent elements has not been performed yet, it is determined to be no, and the process returns to step S12 to count “1” and, for example, another adjacent element (Elem_3) that has not been analyzed, that is, An analysis process similar to the above is performed for the adjacent element (Elem15). On the other hand, if the determination in step S17 is yes, that is, if the analysis processing for all of the adjacent elements (Elem12), (Elem10), and (Elem15) extracted in step S7 is completed, the process proceeds to step S18.

  In step S18, of the adjacent elements (Elem12), (Elem10) and (Elem15), the highest node (Node_max) temporarily stored in the RAM 17, that is, the highest of the adjacent elements (Elem12) shown in FIG. The node (Node39) is stored in the RAM 17 as the highest node (Node_max) in this routine, and the line segment connecting the reference node (Node38) and the highest node (Node39) (see the arrow A in FIG. 5A) is the most. Assuming a steep slope, this line segment is set to a part of the air trajectory. In this way, the highest node (Node_max) that forms the steepest line segment from each of the adjacent elements (Elem12), (Elem10), and (Elem15) is memorized, and that line segment is used as part of the air trajectory. The processing of setting step S18 constitutes a node storing step in the present invention.

  As described above, the processing up to step S18 represents a series of processing in the current routine, and in subsequent step S19, preparation for performing processing in the next routine is performed. That is, in step S19, the adjacent element (Elem12) having the highest node (Node39) stored in step S18 is set as (j), and the lowest as the new lowest element (Elem_j) in each next step (next routine). The element (Elem12) is set, and the reference node (Node39) is set with the highest node (Node_j_h) of the set lowest element (Elem12) as a new reference node.

  In step S19, whether or not the number of adjacent elements including the set new reference node (Node39) is equal to or less than a predetermined number (three or less), or the node of the adjacent element and the reference node (Node39) are connected. It is determined whether or not the slope of the line segment is negative, that is, whether or not the reference node (Node 39) is higher in the gravity direction G than the node of the adjacent element.

  When it is determined that the number of adjacent elements is equal to or less than the predetermined number, there is originally no adjacent element in the place where the adjacent element should exist, and there is a “hole” or “edge” in the portion, and this “hole” or “ If air is exhausted to the outside through the edge, and if the slope of the line segment connecting the node of the adjacent element and the reference node (Node39) is negative, the reference node (Node39) Air is accumulated in the part, and it is determined that the new minimum element (Elem12) has reached (Jmax), that is, the air trajectory simulation has converged (the air trajectory has reached the end point). Then, the process proceeds to step S20.

  In step S20, whether or not analysis processing of other vehicle body panels (side panels, roof panels, etc.) constituting the vehicle body 30 has been completed, that is, the part number (i) is a predetermined number of parts (I) to be analyzed. If it is determined whether or not the part number (i) has reached the number of parts (I) (determined as yes), the process proceeds to step S21 to output an external display.

  In step S21, the line segment formed by the nodes temporarily stored in the RAM 17 in step S18, that is, the air trajectory (see the arrow in FIG. 3) as a simulation result is visually displayed to the operator. For easy understanding, the display controller 20 shown in FIG. However, the contents displayed on the display 12 include, in addition to the display of the air trajectory, information such as the node number forming the air trajectory, characters “normal air escape” (when the number of adjacent elements is a predetermined number or less), “ It may be possible to display characters such as “occurrence of air accumulation” (when the gradient is negative).

  Thus, step S21 for displaying the air trajectory as a simulation result to the outside via the display 12 constitutes an air trajectory display step in the present invention. In step S21, an air trajectory or the like is displayed on the display 12, and then the process proceeds to step S22 to complete the air trajectory simulation.

  In step S19, it is determined as no, that is, the number of adjacent elements including the reference node (Node39) of the lowest element (Elem12) which is a new lowest element (Elem_j), or the nodes of the adjacent elements and the reference node (Node39) If it is determined that the slope of the line connecting the two is positive, the process returns to step S7 and the above-described analysis process (each step) is repeated. In the present embodiment, as shown in FIG. 5B, there are three adjacent elements including the reference node (Node 39) as in No. (7), (8) and (13). The analysis processing described above is continuously performed for (Elem7), (Elem8), and (Elem13).

  If NO is determined in step S20, that is, if it is determined that the part to be analyzed (another vehicle body panel) still exists, the process proceeds to step S23 to analyze another vehicle body panel, and “I = It counts as “i + 1”, and then returns to step S4 to repeatedly perform the above-described analysis processing with another body panel as an analysis target.

As described above in detail, according to the simulation method of the air trajectory in the object to be immersed according to the first embodiment, the numerical calculation model of the floor panel 40 is set to the lowest element and adjacent by the control unit 18 of the fluid analysis device 10. Divide the elements into two-dimensional elements and compare the slopes of the line segments connecting the reference node at the highest position in the gravity direction G of the lowest element and the nodes at the highest position in the gravity direction G of multiple adjacent elements Then, as shown by the arrows in FIG. 5 (c), the simulation is performed such that the air (AIR) trajectory is formed one after another toward the nodes forming the steep line segment, and the resulting air trajectory is It can be output to the display 12.

  Therefore, compared with the case where analysis processing is performed by dividing into three-dimensional elements as before, the calculation time from the initial state to the convergence state for analysis processing can be shortened, and thus the development of the body panel Time can be shortened and the manufacturing cost can be suppressed.

  Further, according to the simulation method of the air trajectory in the object to be immersed according to the first embodiment, since the object to be immersed is the vehicle body 30, the air trajectory in the vehicle body panel constituting the vehicle body 30 having a complicated shape. Can be simulated. For example, it is possible to determine the end point of the predicted air trajectory as an air reservoir, and to form a relief hole or the like for escaping air to the outside of the part, and to secure rigidity by optimizing the number of escape holes etc. In addition, the vehicle body 30 that can be reduced in weight can be efficiently designed.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 6 is a flowchart for explaining the operation of the air trajectory simulation method for the object to be immersed according to the second embodiment, and FIGS. 7A, 7B, and 7C show one of the divided two-dimensional elements. The schematic diagram which extracted and shows the part is each represented.

  In the first embodiment described above, analysis processing is performed based on the coordinate data at the “node” of each element. In the second embodiment, analysis processing is performed based on the coordinate data at the “centroid point” of each element. Like to do. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The HDD 13 and the RAM 17 of the fluid analyzing apparatus 10 shown in FIG. 1 store centroid data (see black dots in FIG. 7) of a plurality of elements (the lowest element and adjacent elements). It consists of direction coordinate data.

  As shown in the flowchart of FIG. 6, in step S6A, the center of gravity (Cent_j_h) at the lowest element (Elem_j) is set as the reference center of gravity, and in this embodiment, it is shown in FIG. 7 (a). Thus, the center of gravity (Cent14) of the lowest element (Elem14) becomes the reference center of gravity. Here, the process of step S6A for setting the reference barycentric point (Elem14) constitutes the reference barycentric point setting step in the present invention.

  In step S9A, the barycentric point (Cent_1_h) of the adjacent element (Elem_1) is set. In this embodiment, the barycentric point (Cent12) of the adjacent element (Elem12) is set.

  In step S10A, the gradient (Tan_1_j) of the line segment connecting the barycentric point (Cent14) of the lowest element (Elem14) set in step S6A and the barycentric point (Cent12) of the adjacent element (Elem12) set in step S9A. That is, the gradient (Tan12) is derived from the following equation (2) based on the coordinate data of each barycentric point.

  In step S11A, the numerical data of the gradient (Tan12) derived from the equation (2) is used as the most steep numerical data (Tan_max) at the present time, and the center of gravity (Cent12) forming the gradient (Tan12) is The center of gravity (Cent_max) at the highest position in the direction G is temporarily stored in the RAM 17.

  In step S13A, the centroid point (Cent_2_h) of the adjacent element (Elem_2) to be set next, that is, the adjacent element (Elem10) is set. In the present embodiment, the centroid point (Cent_2_h) is It becomes the center of gravity (Cent10).

  In step S14A, the gradient (Tan_2_j) of the line segment connecting the reference centroid point (Cent14) set in step S6A and the centroid point (Cent10) set in step S13A, that is, the gradient (Tan10) is expressed by the above equation (2). Similarly, it derives by

  In step S16A, assuming that the gradient (Tan_2_j) is the steepest gradient, the numerical data (Tan_max) of the gradient (Tan_1_j) stored in the RAM 17 is rewritten with the numerical data of the gradient (Tan_2_j), and the gradient (Tan_2_j) is formed. The center of gravity (Cent_2_h) is the center of gravity (Cent_max) at the highest position.

  In step S18A, among the adjacent elements (Elem12), (Elem10), and (Elem15), the center of gravity (Cent_max) temporarily stored in the RAM 17, that is, the center of gravity of the adjacent element (Elem12) shown in FIG. The point (Cent12) is stored in the RAM 17 as the center of gravity (Cent_max) in this routine, and a line segment (see arrow B in FIG. 7A) connecting the reference center of gravity (Cent14) and the center of gravity (Cent12) is obtained. Assuming the steepest slope, this line segment is set to a part of the air trajectory. In this way, the center of gravity (Cent_max) that forms the steepest line segment from each of the adjacent elements (Elem12), (Elem10), and (Elem15) is stored, and that line segment is used as part of the air trajectory. The process of setting step S18A constitutes the center-of-gravity point storing step in the present invention.

  Thereafter, similar to the first embodiment, the analysis process is repeatedly performed as shown in FIG. 7B to simulate the air trajectory as shown in FIG. Can be displayed.

  Also in the method for simulating the air trajectory in the object to be immersed according to the second embodiment configured as described above, the same effects as those of the first embodiment described above can be achieved.

  According to the computer-executable program for executing the simulation method according to the first embodiment (analysis processing using “nodes”) and the second embodiment (analysis processing using “center of gravity”), The fluid analysis device 10 divides the numerical calculation model of the vehicle body 30 into the two-dimensional element of the lowest element and the adjacent element, and the reference node at the highest position in the gravity direction G of the lowest element and the gravity direction of the plurality of adjacent elements The slopes of the line segments connecting the nodes at the highest position in G, or the slopes of the line segments connecting the reference centroid point of the lowest element and the centroid points of a plurality of adjacent elements are compared. Then, as shown in FIG. 5C and FIG. 7C, the air (AIR) trajectory is successively applied to the fluid analyzing apparatus 10 toward the node or the center of gravity that forms the steepest line segment. The formation can be simulated and the resulting air trajectory can be displayed on the display 12.

  Therefore, compared with the case where analysis processing is performed by dividing into three-dimensional elements as before, the calculation time from the initial state to the convergence state for analysis processing can be shortened, and thus the development of the body panel Time can be shortened and the manufacturing cost can be suppressed.

  In addition, this invention is not limited to each embodiment mentioned above, A various change is possible in the range which does not deviate from the summary. For example, in each of the above embodiments, the simulation of only the air trajectory has been shown. However, the present invention is not limited to this, for example, the viscous resistance of air or the electrodeposition solution 35, and other conditions such as ambient temperature and humidity. It is also possible to perform a predetermined calculation in consideration of the analysis conditions, thereby deriving the time until air escapes through the air trajectory and displaying it outside. In this case, it is also possible to display “predicted air discharge time” or the like on the display 12 together with the display of the air trajectory described above.

  In each of the above embodiments, the case where the Z coordinate data of a plurality of adjacent elements have different values has been described as an example. However, when the Z coordinate data of the plurality of adjacent elements has the same value, the air trajectory It is conceivable that the branches will flow so as to flow through both sides. In this case, the same analysis process (each step) may be performed in parallel for each of a plurality of adjacent elements branched.

  Further, in each of the above-described embodiments, the simulation of air trajectories in a plurality of vehicle body panels constituting the vehicle body 30 of the vehicle is shown as the object to be immersed. However, the present invention is not limited to this, and the shape is complicated. Therefore, it can be applied to, for example, a semiconductor as an electronic component.

  Further, in each of the above-described embodiments, the object to be immersed is immersed in the electrodeposition solution 35 and a coating film is deposited on the surface of the object to be immersed (thing to be electrodeposited). However, the present invention is not limited to this, and the present invention can also be applied to a technique of immersing the object to be immersed in a treatment tank filled with a metal solution and performing plating or the like on the surface of the object to be immersed.

It is a block diagram which shows the fluid analysis apparatus which performs the simulation method of the air trajectory in the to-be-immersed process object which concerns on this invention. It is explanatory drawing explaining the coating line of a vehicle body. It is a perspective view which shows the numerical calculation model of the floor panel of a vehicle body. It is a flowchart explaining operation | movement of the simulation method of the air trajectory in the to-be-immersed process object which concerns on 1st Embodiment. (A), (b), (c) is the schematic diagram which extracts and shows a part of the divided | segmented two-dimensional element. It is a flowchart explaining operation | movement of the simulation method of the air trajectory in the to-be-immersed process object which concerns on 2nd Embodiment. (A), (b), (c) is the schematic diagram which extracts and shows a part of the divided | segmented two-dimensional element.

Explanation of symbols

10 Fluid Analysis Device 11 Keyboard 12 Display 13 HDD
14 FDD
15 CPU
16 ROM
17 RAM
18 Control Unit 19 Keyboard Controller 20 Display Controller 21 Disk Controller 22 Network 23 Network Interface Controller 24 System Bus 30 Body Body (Substance to be Dipped)
31 Conveying device 32 Hanger 33 Coating line 34 Electrodeposition tank 35 Electrodeposition solution 40 Floor panel (substance to be immersed)
41 elements

Claims (6)

A method for simulating an air trajectory in an object to be immersed for simulating a trajectory through which air in an air pool generated in the object to be immersed escapes , using a fluid analysis device ,
By the control unit of the fluid analysis device,
Based on a numerical calculation model of the object to be immersed divided into a plurality of elements, a minimum element setting step for setting the element at the lowest position in the direction of gravity as the lowest element;
A reference node setting step of setting a node at the highest position in the lowest element as a reference node;
An adjacent element setting step of setting a plurality of elements including the reference node and adjacent to the lowest element as adjacent elements;
A gradient derivation step for deriving a gradient of a line segment connecting the reference node and each node at the highest position in each adjacent element;
A node storing step of comparing the gradients and storing the node of the line segment having the steepest slope;
The adjacent element including the node stored in the node storage step is set as a new minimum element in each next step, and the adjacent element including the new reference node of the minimum element is equal to or less than a predetermined number, or the node of the adjacent element And an air trajectory display step for displaying a line segment connecting the nodes stored in the node storing step as an air trajectory to the outside . A method for simulating an air trajectory in an object to be immersed. A method for simulating an air trajectory in an object to be immersed for simulating a trajectory through which air in an air pool generated in the object to be immersed escapes , using a fluid analysis device ,
By the control unit of the fluid analysis device,
Based on a numerical calculation model of the object to be immersed divided into a plurality of elements, a minimum element setting step for setting the element at the lowest position in the direction of gravity as the lowest element;
A reference barycentric point setting step of setting the barycentric point of the lowest element as a reference barycentric point;
An adjacent element setting step of setting adjacent elements including a node at the highest position in the lowest element as adjacent elements;
A gradient derivation step for deriving gradients of line segments connecting the reference centroid point and each centroid point of each adjacent element;
A center-of-gravity point storing step of comparing the respective slopes and storing the center-of-gravity point of the line segment having the steepest slope;
The adjacent element including the centroid point stored in the centroid point storage step is set as a new minimum element in each next step, and the adjacent element including the new reference centroid point of the minimum element is equal to or less than a predetermined number, or the adjacent element After repeating the above steps until the gradient between the element center of gravity and the new reference center of gravity is negative, the line segment connecting the centers of gravity stored in the center of gravity center storage step is displayed outside as an air trajectory. simulation method of an air trajectory in the dipping treatment product is characterized that you run a trajectory display step.   3. The method for simulating an air trajectory in an object to be immersed according to claim 1 or 2, wherein the object to be immersed is a vehicle body. A computer-executable program for executing a simulation method of an air trajectory in an object to be immersed for simulating a trajectory through which air in an air pool generated in the object to be immersed escapes,
Based on a numerical calculation model of the object to be immersed divided into a plurality of elements, a minimum element setting step for setting the element at the lowest position in the direction of gravity as the lowest element;
A reference node setting step of setting a node at the highest position in the lowest element as a reference node;
An adjacent element setting step of setting a plurality of elements including the reference node and adjacent to the lowest element as adjacent elements;
A gradient derivation step for deriving a gradient of a line segment connecting the reference node and each node at the highest position in each adjacent element;
A node storing step of comparing the gradients and storing the node of the line segment having the steepest slope;
The adjacent element including the node stored in the node storage step is set as a new minimum element in each next step, and the adjacent element including the new reference node of the minimum element is equal to or less than a predetermined number, or the node of the adjacent element And an air trajectory display step of displaying the line segment connecting the nodes stored in the node storage step as an air trajectory to the outside after repeating each step until the gradient of the new reference node becomes negative. A computer-executable program for executing a method for simulating an air trajectory in an object to be immersed. A computer-executable program for executing a simulation method of an air trajectory in an object to be immersed for simulating a trajectory through which air in an air pool generated in the object to be immersed escapes,
Based on a numerical calculation model of the object to be immersed divided into a plurality of elements, a minimum element setting step for setting the element at the lowest position in the direction of gravity as the lowest element;
A reference barycentric point setting step of setting the barycentric point of the lowest element as a reference barycentric point;
An adjacent element setting step of setting adjacent elements including a node at the highest position in the lowest element as adjacent elements;
A gradient derivation step for deriving gradients of line segments connecting the reference centroid point and each centroid point of each adjacent element;
A center-of-gravity point storing step of comparing the respective slopes and storing the center-of-gravity point of the line segment having the steepest slope;
The adjacent element including the centroid point stored in the centroid point storage step is set as a new minimum element in each next step, and the adjacent element including the new reference centroid point of the minimum element is equal to or less than a predetermined number, or the adjacent element After repeating the above steps until the gradient between the element center of gravity and the new reference center of gravity is negative, the line segment connecting the centers of gravity stored in the center of gravity center storage step is displayed outside as an air trajectory. A computer-executable program for executing a simulation method of an air trajectory in an object to be immersed, comprising a trajectory display step. 6. A computer-executable program for executing a method for simulating an air trajectory in an object to be immersed according to claim 4 or 5, wherein the object to be immersed is a vehicle body. A computer-executable program for executing the simulation method.

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