JP6222302B1 - Method and apparatus for optimization analysis of joint positions of vehicle bodies - Google Patents

Abstract

A vehicle body joint position optimization analysis method and apparatus for obtaining an optimum position of an additional joint point to be added to a vehicle body in consideration of an inertial force acting on a fitting or a lid when the vehicle is running. A vehicle body joint position optimization analysis method according to the present invention uses a vehicle body skeleton model 21 having a joint point 25 for joining parts and a fixed connection part 23 for fixing or connecting a fitting or a lid. The additional joint point 33 to be added to the joint part between the parts is obtained, and a joint candidate 31 is generated between the joint points 25 set in the vehicle body skeleton model 21 in advance, and the joint article or the lid is formed. The optimization analysis model generation step S1 for setting the corresponding mass, the optimization analysis condition setting step S3 for setting the optimization analysis conditions, and the inertial force acting on the fitting or lid An optimization analysis step S5 for selecting an additional joint point 33 satisfying the condition from the joint candidates 31 is provided. [Selection] Figure 1

Description

  The present invention relates to an optimization analysis method and apparatus for a joint position of a vehicle body of an automobile. The present invention relates to an optimization analysis method and apparatus.

2. Description of the Related Art In recent years, in the automobile industry, weight reduction of vehicle bodies due to environmental problems has been promoted, and computer-aided engineering (hereinafter referred to as “CAE”) analysis has become an indispensable technology for vehicle body design. In this CAE analysis, rigidity analysis, collision analysis, vibration analysis, and the like are performed, which greatly contributes to improvement of vehicle body performance. CAE analysis not only evaluates vehicle performance, but also uses optimization analysis methods such as mathematical optimization, plate thickness optimization, shape optimization, topology optimization, etc. It is possible to support the design of a vehicle body that has improved collision resistance and the like.
For example, Patent Document 1 discloses a technique for optimizing components of a complicated structure by topology optimization.

JP 2010-250818 A

  In addition, a structure such as a vehicle body is formed by joining a plurality of parts by welding or the like, and if the amount of joining at the part to be joined is increased (for example, addition of spot welding points), the rigidity of the whole structure Is known to improve. However, it is desired to reduce the amount of bonding as much as possible from the viewpoint of cost.

Therefore, as a method for obtaining a position at which the joining of parts is added in order to improve the rigidity of the vehicle body, there are a method of setting by experience and intuition, and a method of adding to a portion where stress is large by stress analysis.
However, in the method of setting the position to add the welding position based on experience and intuition, the welding position is not set by searching for the position necessary to improve the rigidity. Therefore, it must be said that the efficiency is low in terms of cost.
In addition, in the method of adding to the part where the stress is large by stress analysis, although the change is seen compared with before the addition, the characteristic only in the vicinity of the part added as the welding position is improved, but the characteristic of another part is relative. Therefore, when the entire vehicle body is evaluated, the welding position to be added is not necessarily optimal.

  In addition, if adjacent welding positions are too close due to the addition of a welding position, when welding, current flows to the previously welded part (diverted flow), and sufficient current does not flow to the part to be additionally welded. , Welding may be incomplete.

  Thus, in order to improve the performance such as the rigidity of the vehicle body, it is conceivable to apply the optimization technique disclosed in Patent Document 1, but this technique is suitable for the optimum welding position for forming a structure such as the vehicle body. It is not disclosed how to apply optimization techniques for optimization.

Furthermore, when the state in which the automobile vehicle is actually traveling is considered, for example, when the behavior of the vehicle body changes due to a lane change or the like, the inertia acting on the fitting or lid disposed away from the center position of the vehicle. The force greatly affects the deformation of the body frame. This is because the mass of a component (assembly; assembly) that is a combination of multiple parts, even if it is a fitting or lid, may be 10 kg or more. This is because it cannot be ignored. Therefore, when evaluating and improving the performance of the vehicle body skeleton, it is desirable to consider the inertial force that acts on the fitting or the lid during actual travel.
In the present invention, the fittings collectively refer to engines, transmissions, seats, and the like, and the lids collectively refer to doors, trunks, hoods, and the like.

  However, in general, the appearance and design of the vehicle are not decided at the initial stage of the body frame design, and lids and fittings that are greatly influenced by the appearance and design of the vehicle are finally decided at the latter stage of design. Many.

  For this reason, it is difficult to evaluate the performance of the vehicle body skeleton in consideration of the inertial force acting on the fittings and the lid in the actual traveling state before the shape of the fittings and the lid is determined. Furthermore, even if the shape of the fittings and lids is determined in the late stage of the design, the CAE analysis is performed on the vehicle (full body) in which the fittings and lids are arranged, and the performance of the vehicle skeleton is evaluated. There is no time for new car development to go back and modify the body frame design and joint position to add. Therefore, in the past, the performance evaluation and design of the vehicle body skeleton has been forced by CAE analysis only for the vehicle body skeleton.

  The present invention has been made in order to solve the above-described problems, and in a vehicle body skeleton model in which a plurality of parts are joined as a part set, even before a fitting or lid is determined. In consideration of the inertial force acting on the fitting or the lid when the vehicle is running, the joint position of the vehicle body that can determine the additional joint point or the optimum joint position to be added to the part to be joined as the component set It is an object of the present invention to provide an optimization analysis method and apparatus.

(1) The method for optimizing the joining position of the vehicle body according to the present invention includes a plurality of parts composed of planar elements and / or three-dimensional elements, and joining points or joints joining the plurality of parts as a part set. Using a vehicle body skeleton model of an automobile having a fixed connecting portion for fixing or connecting a fitting or a lid, and a computer performs an optimization analysis of point bonding or continuous bonding used for bonding the component set as follows. A step, wherein the computer sets an additional joint point or additional joint candidate to be joined to the part set and a mass corresponding to a fitting or a lid in the vehicle skeleton model, An optimization analysis model generation step for generating an optimization analysis model to be analyzed by the optimization analysis, and a computer causes the optimization analysis condition for the optimization analysis model by an instruction from an operator. An optimization analysis condition setting step to be set, and the computer performs an optimization analysis in consideration of an inertial force acting on the optimization analysis model when the vehicle is running, and an additional junction or an additional condition that satisfies the optimization analysis condition An optimization analysis step of selecting a joint from the joint candidates, and in the optimization analysis model generation step, the mass is set at a predetermined position in a region where the fitting or lid is fixed or connected In addition, the joining candidates are set at a predetermined interval between joining points or joints that are set in advance in each part set of the vehicle body skeleton model.

(2) In the device described in (1) above, the predetermined position in the optimization analysis model generation step is set on a straight line or a curve connecting the fixed connecting portions.

(3) In the above (2), in the case where the fitting or the lid is a rotationally movable part that is rotatable, the predetermined position is on a rotationally movable central axis when the fitting or the lid is rotationally movable. It is characterized by being set to a position excluding.

(4) In the device described in (1) above, the predetermined position in the optimization analysis model generation step is set on a plane or a curved surface surrounded by a straight line or a curve connecting the fixed connecting portions (on the straight line or the curved line) Is excluded).

(5) In the device according to any one of (1) to (4), the optimization analysis model generation step includes a mass element, a mass element, and a mass element corresponding to a mass of the fitting or the lid. It sets using the rigid body element which connects the said fixed connection part, It is characterized by the above-mentioned.

(6) In the device according to any one of (1) to (4), the optimization analysis model generation step is set using a mass element and a beam element, and the mass element and the mass element has a mass The sum corresponds to the mass of the fitting or lid fixed or connected to the fixed connecting portion.

(7) In the device according to any one of (1) to (4), the optimization analysis model generation step is set using a beam element having a mass corresponding to a mass of the fitting or the lid. It is characterized by.

(8) The vehicle body joining position optimization analyzing apparatus according to the present invention includes a plurality of parts including planar elements and / or three-dimensional elements, and joining points or joints joining the plurality of parts as a part set. Using a vehicle body skeleton model having a fixed connecting portion for fixing or connecting a fitting or a lid, and performing optimization of point bonding or continuous bonding used for bonding the component set, An optimization analysis model to be set as an analysis target of an optimization analysis by setting an additional joint point or a joint candidate of an additional joint to be joined to a part set and a mass corresponding to a fitting or a lid in the body frame model An optimization analysis model generation unit that generates the optimization analysis condition setting unit that sets optimization analysis conditions for the optimization analysis model, and inertia that acts on the optimization analysis model when the vehicle is running The performed optimization analysis in consideration, the optimization analysis satisfy additional junction or additional junction and an optimization analysis unit for selecting from among the joint candidates,
The optimization analysis model generation unit sets the mass to a predetermined position in a region where the fitting or lid is fixed or connected, and the joining candidate is preliminarily set in each part set of the vehicle body skeleton model. It is characterized in that it is set at a predetermined interval between set joint points or joints.

(9) In the device described in (8) above, the predetermined position of the mass set by the optimization analysis model generation unit is on a straight line or a curve connecting the fixed connection unit It is.

(10) In the above-described (9), in the case where the fitting or the lid is a rotationally movable part that is rotatable, the predetermined position is on a rotationally movable central axis when the fitting or the lid is rotationally movable. It is characterized by being set to a position excluding.

(11) In the device described in (8) above, the predetermined position of the mass set by the optimization analysis model generation unit is set on a plane or a curved surface surrounded by a straight line or a curve connecting the fixed connection units ( Except on the straight line or curved line).

(12) In the device according to any one of (8) to (11), the optimization analysis model generation unit calculates a mass corresponding to a mass of the fitting or the lid, a mass element, and the mass element. It sets using the rigid body element which connects the said fixed connection part, It is characterized by the above-mentioned.

(13) In the device according to any one of (8) to (11), the optimization analysis model generation unit is set using a mass element and a beam element, and the mass element and the mass element have a mass The sum corresponds to the mass of the fitting or lid fixed or connected to the fixed connecting portion.

(14) In the device according to any one of (8) to (11), the optimization analysis model generation unit is set using a beam element having a mass corresponding to a mass of the fitting or the lid. It is characterized by.

  In the present invention, it is composed of a plurality of parts composed of planar elements and / or three-dimensional elements, and an additional joint point or joint part for joining the plurality of parts as a part set and a fixed connection for fixing or connecting a fitting or a lid. The computer performs the following steps for the optimization analysis of the point joint or continuous joint used for joining the parts set, using the vehicle body skeleton model of the automobile having the part, and the computer Optimization analysis for generating an optimization analysis model to be set as an analysis target of the optimization analysis by setting an additional joint point in the assembly or a joint candidate of the additional joint and a mass corresponding to the fitting or the lid in the body frame model A model generation step and an optimization analysis condition setting step in which the computer sets optimization analysis conditions for the optimization analysis model in accordance with an instruction from the operator The computer performs an optimization analysis for the optimization analysis model in consideration of an inertial force acting when the vehicle is running, and an additional joint point or an additional joint satisfying the optimization analysis condition is selected from the joint candidates. Selecting an optimization analysis step, wherein, in the optimization analysis model generation step, the mass is set to a predetermined position in a region where the fitting or lid is fixed or connected to a fixed connection portion of the vehicle body skeleton model. And the joint candidate is set at a predetermined interval between joint points or joints set in advance in each part set of the vehicle body skeleton model, before the fitting or the lid is determined. However, additional joint points added to the component assembly to improve the rigidity of the automobile by performing an optimization analysis in consideration of the inertial force acting on the fitting or lid when traveling It can be obtained efficiently optimal position of the additional joints.

It is a block diagram of the optimization analysis apparatus of the joint position of the vehicle body which concerns on embodiment of this invention. It is explanatory drawing explaining the joint point preset to the vehicle body frame | skeleton model used by this Embodiment and this vehicle body frame | skeleton model ((a): perspective view, (b): side view). It is explanatory drawing explaining the vehicle body skeleton model used by this Embodiment, and the fixed connection part set to this vehicle body skeleton model. It is a figure which shows an example of the optimization analysis model by which the joint candidate was produced | generated by the vehicle body frame | skeleton model in the optimization analysis model production | generation step which concerns on this Embodiment. It is a figure which shows an example of the optimization analysis model by which the mass element was set to the vehicle body frame | skeleton model in the optimization analysis model production | generation step which concerns on this Embodiment. It is a figure which shows an example of the optimization analysis model produced | generated in the optimization analysis model production | generation step which concerns on this Embodiment. It is a flowchart figure which shows the flow of a process of the optimization analysis method of the joining position of the vehicle body which concerns on embodiment of this invention. It is explanatory drawing explaining the production | generation of the joint candidate in the optimization analysis model production | generation step which concerns on this Embodiment, and selection of the joint candidate in an optimization analysis step ((a): Joint point, (b): Joint candidate of FIG. Generation, (c): selection of additional junction points). It is explanatory drawing explaining the predetermined position where a mass element is set in the optimization analysis model generation step which concerns on this Embodiment. It is a figure which shows the other example of the optimization analysis model by which the mass element was set to the vehicle body frame | skeleton model in the optimization analysis model production | generation step which concerns on this Embodiment. It is explanatory drawing explaining the setting method of a mass element in the optimization analysis model production | generation step which concerns on this Embodiment. In an Example, it is explanatory drawing explaining the optimization analysis model made into the comparative example ((a): There is no mass setting (comparative example 1), (b) There exists a rotary door component (comparative example 2)). It is explanatory drawing explaining the load restraint conditions in the static torsion of a vehicle body in an Example ((a): Front side load provision + rear side restraint, (b): Front side restraint + rear side load provision). In an Example, it is a figure which shows the analysis result of the additional joining point selected by the optimization analysis in a static torsional load condition. In an Example, it is a graph which shows the relationship between the number of additional joining points selected by the optimization analysis in a static torsion load condition, and the rigidity improvement rate of a vehicle body. In an Example, it is explanatory drawing explaining the load conditions supposing the driving | running | working state of the motor vehicle. In an Example, it is a figure which shows the analysis result of the additional junction selected by the optimization analysis in the load conditions supposing the lane change (the 1). In an Example, it is a figure which shows the analysis result of the additional junction selected by the optimization analysis in the load conditions supposing the lane change (the 2). In an Example, it is a graph which shows the relationship between the number of additional joining points selected by the optimization analysis on the load conditions supposing lane change, and the rigidity improvement rate of a vehicle body. In an Example, it is a figure which shows the analysis result of the distortion energy distribution of the vehicle body obtained by the optimization analysis on the load conditions supposing lane change (the 1). In an Example, it is a figure which shows the analysis result of the strain energy distribution of the vehicle body obtained by the optimization analysis on the load conditions supposing lane change (the 2). In an Example, it is explanatory drawing explaining the load conditions in which a load acts on the front side of a vehicle body in the driving | running | working state of a motor vehicle. In an Example, it is a figure which shows the analysis result of the additional junction selected by the optimization analysis in the load conditions in which a load acts on the front side of a vehicle body in the driving | running | working state of a motor vehicle (the 1). In an Example, it is a figure which shows the analysis result of the additional junction selected by the optimization analysis in the load conditions in which a load acts on the front side of a vehicle body in the driving | running | working state of a motor vehicle (the 2).

  A vehicle body joint position optimization analysis method and apparatus according to an embodiment of the present invention will be described below with reference to FIGS. Prior to the description of the optimization analysis method and apparatus for the joint position of the vehicle body, the vehicle body skeleton model that is the subject of the present invention will be described.

<Body frame model>
As shown in FIGS. 2 and 3, the vehicle body skeleton model 21 used in the present invention is composed of a plurality of parts such as chassis parts. Each part of the vehicle body skeleton model 21 is modeled using planar elements and / or three-dimensional elements.

  In the vehicle body skeleton model 21, each part is provided with a joint point or a joint provided at a part to be joined as a part assembly. For example, in the vehicle body skeleton model 21 in which the parts are joined by spot welding, FIG. As shown, a joining point 25 is set in advance at a part to be joined for each component assembly.

  Furthermore, as shown in FIG. 3, the vehicle body skeleton model 21 has a fixed connecting portion 23 for fixing or connecting a fitting or a lid. As an example of the fixed connection portion 23, there are a hinge 23a, a hinge 23b, and a striker 23c for fixing or connecting the revolving door as shown in FIG. 3, but the fixed connection portion 23 is not limited to these, for example, Included are those for fixing fittings such as engine mounts for fixing the engine, and those for fixing or connecting lids such as slide doors and bonnets other than revolving doors.

  Element information of each part constituting the vehicle body skeleton model 21, information on the joint point 25 (FIG. 2) in each part set, and the fixed connection part 23 (FIG. 3) for fixing or connecting the fitting or the lid are as follows. It is stored in the model file 20 (see FIG. 1).

<Optimization analyzer>
The configuration of the vehicle body joint position optimization analysis apparatus 1 (hereinafter simply referred to as “optimization analysis apparatus 1”) according to the present embodiment will be described below mainly based on the block diagram shown in FIG.

  The optimization analysis apparatus 1 according to the present embodiment optimizes additional joint points or additional joints that are added to a part to be joined as a part set of a plurality of parts constituting the vehicle body skeleton model 21 (see FIGS. 2 and 3). The display device 3, the input device 5, the storage device 7, the work data memory 9, and the arithmetic processing unit 10 are configured by a PC (personal computer) or the like.

  The display device 3, the input device 5, the storage device 7, and the work data memory 9 are connected to the arithmetic processing unit 10, and each function is executed by a command from the arithmetic processing unit 10.

≪Display device≫
The display device 3 is used for displaying analysis results and the like, and includes a liquid crystal monitor or the like.

≪Input device≫
The input device 5 is used for a display instruction of the body skeleton model file 20, an operator's condition input, and the like, and includes a keyboard, a mouse, and the like.

≪Storage device≫
The storage device 7 is used for storing various files such as the vehicle body skeleton model file 20 and is configured by a hard disk or the like.

≪Work data memory≫
The work data memory 9 is used for temporary storage and calculation of data used in the arithmetic processing unit 10, and is configured by a RAM (Random Access Memory) or the like.

≪Operation processing part≫
As shown in FIG. 1, the arithmetic processing unit 10 includes an optimization analysis model generation unit 11, an optimization analysis condition setting unit 13, and an optimization analysis unit 15, and is configured by a CPU (central processing unit) such as a PC. Is done. Each of these units functions when the CPU executes a predetermined program.
Hereinafter, the function of each unit in the arithmetic processing unit 10 will be described.

≪Optimization analysis model generation part≫
The optimization analysis model generation unit 11 generates an additional joint point to be added to a part to be joined as a part set of the parts of the vehicle body skeleton model 21 or a joint candidate of the additional joint, and calculates the mass corresponding to the fitting or the lid as the body skeleton. The model 21 is set and an optimization analysis model to be analyzed is generated.

  FIG. 4 shows an example in which the joint candidate 31 is generated in the vehicle body skeleton model 21. The joint candidates 31 are densely generated at predetermined intervals (10 mm intervals) between the joint points 25 (FIG. 1) set in advance in each part set of the vehicle body skeleton model 21. In FIG. 4, the joint point 25 (see FIG. 2) set in advance in the vehicle body skeleton model 21 is not displayed.

FIG. 5 shows an example in which a mass corresponding to a fitting or a lid is set in the vehicle body skeleton model 21.
In FIG. 5, a mass element 41 having a mass corresponding to a revolving door that is a lid is set, and the mass element 41 is set at a predetermined position in a region where the revolving door is fixed or connected. The mass element 41 is positioned on a straight line connecting the hinge 23a and the striker 23c, and the mass element 41, the hinge 23a, and the mass element 41 and the striker 23c are connected by a rigid element 45.

  FIG. 6 shows an example of the optimization analysis model 51 in which the joining candidate 31 is generated in the vehicle body skeleton model 21 (see FIG. 4) and the mass element 41 is set in the vehicle body skeleton model 21 (see FIG. 5).

≪Optimization analysis condition setting part≫
The optimization analysis condition setting unit 13 sets optimization analysis conditions for the joint candidate 31 and sets two types of optimization analysis conditions, that is, a target condition and a constraint condition.

  The objective condition is a condition set according to the purpose of the optimization analysis by the optimization analysis model 51. For example, there are minimizing the strain energy, maximizing the absorbed energy, and minimizing the generated stress. Only one objective condition is set.

  The constraint condition is a constraint imposed when performing the optimization analysis. For example, the optimization analysis model 51 generated from the vehicle body skeleton model 21 after joining the respective parts has a predetermined rigidity. A plurality of constraint conditions can be set.

≪Optimization analysis part≫
The optimization analysis unit 15 targets the joint candidate 31 in the optimization analysis model 51 and performs an optimization analysis in consideration of the inertial force acting when the vehicle is running. Significant junction candidates 31 that satisfy the optimization analysis conditions (objective conditions and constraint conditions) set by the condition setting unit 13 are selected.

Topology optimization can be applied to the optimization analysis by the optimization analysis unit 15.
When the density method is used in topology optimization, if there is a large intermediate density, discretization is preferable, which is expressed by Expression (1).

K (ρ) = ρ ^p K (1)
However,
K : Stiffness matrix that penalizes the stiffness matrix of the element
K: element stiffness matrix ρ: normalized density
p: Penalty coefficient

  Although the penalty coefficient often used for discretization is 2 or more, it has been clarified that a value of 4 or more is preferable as the penalty coefficient in the optimization of the joint position according to the present invention.

  The optimization analysis unit 15 may perform a topology optimization process or may be an optimization process based on another calculation method. Therefore, as the optimization analysis unit 15, for example, commercially available analysis software using a finite element can be used.

<Optimization analysis method for joint position>
An optimization analysis method (hereinafter simply referred to as “optimization method”) of the joining position of the vehicle body according to the present embodiment will be described below.

The method for optimizing the joining position according to the present embodiment is composed of a plurality of parts composed of planar elements and / or three-dimensional elements, and fixes the joint point 25 and the fitting or lid that join the plurality of parts as a part set. Alternatively, using a vehicle body skeleton model 21 (see FIGS. 2 and 3) having a fixed connecting portion 23 to be connected, optimization of point bonding or continuous bonding used for bonding the component set is performed. As shown in FIG. 7, an optimization analysis model generation step S1, an optimization analysis condition setting step S3, and an optimization analysis step S5 are provided.
Hereinafter, each step will be described. Note that each step is executed by the optimization analysis apparatus 1 configured by a computer.

<< Optimization analysis model generation step S1 >>
The optimization analysis model generation step S1 generates a joint candidate 31 to be added to a part to be joined as a part set for a plurality of parts constituting the vehicle body skeleton model 21 (see FIG. 4), and a mass corresponding to a fitting or a lid. 1 is set in the vehicle body skeleton model 21 (see FIG. 5), and an optimization analysis model 51 is generated (see FIG. 6). The optimization analysis apparatus 1 shown in FIG. Performed by the model generation unit 11.

The generation of the junction candidate 31 in the optimization analysis model generation step S1 can be performed by the following procedure.
In the vehicle body skeleton model 21, as shown in FIG. 8 (a), joint points 25 are set in advance at predetermined intervals D at portions where parts 27 constituting the vehicle body skeleton model 21 are joined as a part set. To do.

  In this case, in the optimization analysis model generation step S1, as shown in FIG. 8B, the junction candidates 31 are set densely at a predetermined interval d (<D) between the junction points 25.

  Further, the setting of the mass corresponding to the fitting or lid in the optimization analysis model generation step S1 is performed by placing the mass element 41 at a predetermined position in the region where the fitting or lid is fixed or coupled as shown in FIG. This is done by setting.

  As shown in FIG. 9, the predetermined position for setting the mass element 41 connects the plurality of fixed connecting portions 23 (23a, 23b, 23c) (23a and 23c, 23b and 23c, 23a and 23b) on a straight line L ( FIG. 9A) or on a curve connecting the fixed connecting portions 23 along the shape of the vehicle body to which a lid or the like is attached.

  In a rotationally movable part in which a fitting or a lid is rotationally movable like a rotational door, there is a rotationally movable central axis when the rotational door is rotationally movable on a line connecting the hinges 23a and 23b of the rotational door. The rotationally movable central axis is substantially at the same position as the boundary of the region where the revolving door is fixed or connected to the vehicle body skeleton model 21.

  On the other hand, the line connecting the hinge 23a and the striker 23c of the revolving door and the line connecting the hinge 23b and the striker 23c are located inside the region where the revolving door is fixed or connected to the vehicle body skeleton model 21.

  In setting the mass corresponding to the fitting or the lid in the vehicle body skeleton model 21, it is more preferable that the inside of the vehicle body skeleton model 21 is set inside than the boundary of the region where the fitting or the lid is fixed or connected. This is preferable in considering the inertial force acting on the fitting or the lid in the optimization analysis step S5 described later.

  Therefore, the predetermined position for setting the mass corresponding to the fitting or lid is set on a straight line L connecting a plurality of fixed connecting portions 23 or, among the curves, the rotationally movable central axis when the fitting or lid is rotationally movable. It is desirable to set the position excluding.

  Further, the predetermined position for setting the mass corresponding to the fitting or the lid is not limited to the straight line L or the curved line, but is on the plane P surrounded by the straight line L (FIG. 9B). Or it is good also on the curved surface along the shape of the vehicle body enclosed with the said curve and to which the lid | cover etc. were mounted | worn.

  Here, since the straight line L or the curved line is a boundary of the plane P or the curved surface, it is desirable to set a mass corresponding to the fitting or the lid inside the boundary. Therefore, it is more preferable to set the predetermined position for setting the mass corresponding to the fitting or the lid on the plane P excluding the straight line L or the curved line or on the curved surface.

  Further, for example, when the fitting is fixed or connected by four fixed connecting portions, the fixed connecting portions are connected by a straight line so that two straight lines intersect each other, and the mass corresponding to the fitting on the straight line It is preferable to set an element. Also in this case, the fixed connecting portions may be connected by a curve in accordance with the curvature of the vehicle body, and the mass element may be set on the curve.

  Specific mass setting methods for setting the mass at the predetermined position include, for example, the following (1) to (3).

(1) The mass element 41 having a mass corresponding to the mass of the fitting or the lid is set at the predetermined position, and the mass element 41 and the fixed connecting portion 23 (hinge 23a or striker 23c) are connected using the rigid element 45. (See FIGS. 5 and 10).

  FIG. 5 is an example in which one mass element 41 is set on the center of the straight line L connecting the fixed connecting portions 23. However, as shown in FIG. 41 may be set. When a plurality of mass elements 41 are set, the mass of each mass element 41 may be determined so that the total mass of each mass element 41 corresponds to the mass of the fitting or the lid.

(2) A mass element 41 having a mass corresponding to the mass of the fitting or lid is set at the predetermined position, and the mass element 41 and the fixed connecting portion 23 are connected using the beam element 47 (see FIG. 11A). ). The sum of the mass of each of the mass element 41 and the beam element 47 is set so as to correspond to the mass of the fitting or lid fixed or coupled to the fixed coupling portion 23.

  The mass of the beam element 47 is determined by the cross-sectional area given as the cross-sectional characteristic of the beam element 47 and the material density given as the material characteristic. The cross-sectional area of the beam element 47 is determined by giving the radius of the beam element 47, for example.

  Further, in the optimization analysis step S5 described later, it is necessary to appropriately set the cross-sectional characteristics and material characteristics necessary for transmitting the load due to the inertial force acting on the mass element 41 and the beam element 47 to the vehicle body skeleton. is there.

  The beam element 47 is a linear element and may be a rod element (bar element) as long as it can transmit a tensile and compressive load acting in the axial direction of the element, and the mass of the rod element is , Similarly to the beam element 47, the cross-sectional area (or radius) given as a cross-sectional characteristic and the material density given as a material characteristic are set.

(3) It sets using only the beam element 47 which has the mass corresponded to the mass of a fitting or a cover (refer FIG.11 (b)).
The mass of the beam element 47 is determined by the cross-sectional area given as the cross-sectional characteristic of the beam element 47 and the material density given as the material characteristic. For example, the cross-sectional area is determined by giving the radius of the beam element 47.

≪Optimization analysis condition setting step≫
In the optimization analysis condition setting step S3, optimization analysis conditions are set for the bonding candidate. In the optimization analysis apparatus 1, the optimization analysis condition setting unit 13 performs the instruction according to the operator's instruction.

  There are two types of optimization analysis conditions set in the optimization analysis condition setting step S3: objective conditions and constraint conditions.

≪Optimization analysis step≫
In the optimization analysis step S5, the analysis model generated in the optimization analysis model step S1 is subjected to an optimization analysis in consideration of the inertial force acting when the vehicle is running, and is set in the optimization analysis condition setting step S3. An additional joint point or an additional joint that satisfies the optimization analysis condition is selected from the joint candidates 31, and the optimization analysis unit 15 performs the optimization analysis device 1.

  For example, in the component 27 shown in FIG. 8, in the optimization analysis step S5, optimization analysis is performed on the joint candidate 31 set in the component 27, and the optimization analysis condition is set as shown in FIG. The joining candidate 31 that is satisfied is selected as the additional joining point 33, and the joining candidate 31 that is not selected is erased as the erasing joining point 35.

  Topology optimization can be applied to the optimization analysis in the optimization analysis step S5. Furthermore, when applying the density method in topology optimization, it is preferable to set the penalty coefficient of the element to 4 or more to perform discretization.

  In the optimization analysis, the inertial force acting on the fitting or the lid when the vehicle is running is considered using the inertia relief method. The inertia relief method is an analysis method for obtaining stress and strain from the force acting on an object in constant acceleration motion in a state where the object is supported (free support state) at the support point that becomes the reference of the coordinate of inertia force, It is used for static analysis of moving airplanes and ships.

  As described above, according to the optimization analysis method and apparatus for the joining position of the vehicle bodies according to the present embodiment, the joining point that joins a plurality of parts as a part set, and the fixed connection that fixes or connects the fitting or the lid A vehicle body skeleton model having a part, an additional joint point to be added to the component set or a joint candidate of the additional joint part, and a mass corresponding to a fitting or a lid, and the vehicle body from among the joint candidates An optimization analysis for selecting an additional joint that maximizes the rigidity of the skeletal model is performed by taking into account the inertial force acting on the fitting or lid when the vehicle is running, before the fitting or lid is determined. Even if it exists, the optimal position of the additional joining point added in order to improve the rigidity of the motor vehicle at the time of driving | running | working or an additional junction part can be calculated | required.

  Further, in the optimization analysis method and apparatus for the joint position of the vehicle body according to the present invention, the parts are joined as a part set by not including the joint points set in advance in the vehicle body skeleton model in the object of the optimization analysis. It can be prevented that the joint point is erased in the process of the optimization analysis and the parts are separated from each other and the optimization analysis is stopped at that time.

  In the above description, the joint point to be joined as a part set by spot welding is the object of analysis, but the optimization analysis method and apparatus for the joining position of the vehicle body according to the present invention is not limited to spot welding. It can be applied to the case where an optimum joining position is obtained when joining a set of parts by continuous joining such as laser welding or arc welding.

Hereinafter, an experiment for confirming the effect of the present invention was performed, which will be described.
The experiment targets the vehicle body skeleton model 21 shown in FIGS. 2 and 3, sets candidate joints to be subjected to optimization analysis to the vehicle body skeleton model 21, and fixes the rotating door component as a lid to the fixed connection portion 23. Alternatively, the optimization analysis of the joining position was performed using an optimization analysis model in which a mass corresponding to the rotating door component was set at a predetermined position in the connected region.

  In this embodiment, the mass of the vehicle body skeleton model 21 is about 300 kg, and the mass of the rotating door components set in the vehicle body skeleton model 21 is 10 kg per piece.

  Therefore, the 10 mass elements 41 are evenly arranged on the straight line connecting the upper hinge 23a and the striker 23c of the vehicle body skeleton model 21, and the mass element 41, the hinge 23a and the striker 23c are connected by the rigid element 45. The analysis model 21 was set as the analysis target (see FIG. 10). At this time, the mass (= 1 kg) of each mass element 41 was set so that the total mass of the mass elements 41 would be the mass of the rotating door component.

  Further, joint candidates 31 are set densely as shown in FIG. 8B between joint points 25 (FIG. 2) set in advance in the vehicle body skeleton model 21, and the mass element 41 shown in FIG. The divided optimization analysis model 51 was generated. At this time, the interval between the bonding candidates 31 was set to d = 10 mm.

  Here, in the vehicle body skeleton model 21, there are 3906 joint points 25, so there are 10932 joint candidates 31 to be subjected to optimization analysis.

  In this way, the mass element 41 is set in the vehicle body skeleton model 21 (see FIG. 10), and the optimization analysis model 51 (see FIG. 6) in which the joining candidate 31 is generated is taken as an example of the invention in this embodiment.

  On the other hand, as a comparative example, an optimization analysis model 61 (see comparative example 1, FIG. 12A) in which only joint candidates are set in the vehicle body skeleton model 21 without setting the mass corresponding to the rotating door components. The optimization analysis was also performed on the optimization analysis model 71 (see Comparative Example 2, FIG. 12B) in which the joint candidate and the rotating door component model 73 were combined with the vehicle body skeleton model 21.

  In this embodiment, the optimization analysis condition is set to maximize the vehicle body rigidity as the objective condition, and the additional joint point 33 (FIG. 8) to be added is selected within the range of 0 to 600 points as the constraint condition. The volume ratio was set.

In this embodiment, first, optimization analysis is performed for static torsion, and the mass element 41 corresponding to the rotating door component set in the optimization analysis models 51, 61 and 71 is selected by the optimization analysis. The influence on the additional junction 33 was examined.
FIG. 13 shows a static torsion load constraint condition for the optimization analysis model 51. FIG. 13 (a) shows a vertical subordinate load (100N) applied to one of the front suspension mounting positions (A in the figure) of the vehicle body and a vertical downward load (100N) applied to the other. The mounting position (B in the figure) is constrained.

  On the other hand, FIG. 13B constrains the front suspension mounting position (A in the figure) of the vehicle body, and applies a vertically upward load (100 N) to one of the subframe mounting positions (B in the figure) on the rear side of the vehicle body. A vertical downward load (100 N) is given to

The rigidity in static torsion was evaluated by the average torsional rigidity obtained as follows.
For example, in the case of FIG. 13A, first, a load is applied to the load point (A in FIG. 13) with reference to a straight line connecting the sub-frame mounting position (B in FIG. 13) at the rear of the vehicle body (angle 0 °). The average inclination angle is obtained by averaging the inclination angle of the vehicle body viewed from the front side of the vehicle body from the front side to the rear side of the vehicle body. Then, the average torsional rigidity was obtained by dividing the load applied to the load point by the average inclination angle. Similarly, in the case of FIG. 13B, the average was obtained from the vehicle body rear side to the front side.

  FIG. 14 shows additional joint points 33 selected by the optimization analysis for static torsion (the number of additional joint points = 600 points). 14A shows the results of the invention, FIG. 14B shows the results of analysis in Comparative Example 1, and FIG. 14C shows the results of analysis in Comparative Example 2. Here, the analysis result shown in FIG. 14 is obtained by combining the front load and the rear load, and is obtained by performing the composite optimization with the weight set to the front load: rear load = 1: 1.

  In FIG. 14, when the results of Invention Example, Comparative Example 1 and Comparative Example 2 were compared, no significant difference was found in the position of the additional joint point 33 selected by the optimization analysis.

FIG. 15 shows the result of the rigidity improvement rate per point of the additional joint 33 added by the optimization analysis and the rigidity improvement rate in Invention Example 1, Comparative Example 1 and Comparative Example 2.
In addition, the rigidity improvement rate of FIG. 15 was calculated | required from the average value of the rigidity by a front load and a rear load.
Here, the rigidity improvement rate is a relative change in the average torsional rigidity obtained on the basis of the average torsional rigidity before adding the additional joint 33 by the optimization analysis.

As shown in FIG. 15A, in any of Invention Example 1, Comparative Example 1 and Comparative Example 2, the rigidity improved as the number of additional joints 33 added by the optimization analysis increased.
Further, as shown in FIG. 15B, the smaller the additional joint points 33, the higher the rigidity improvement rate per point (= dot efficiency), and the additional joint points 33 obtained by the optimization analysis method according to the present invention. This means that the election is being conducted properly.

  However, when the results of Invention Example 1, Comparative Example 1 and Comparative Example 2 shown in FIG. 15 are compared, the rigidity improvement rate and the change in the rigidity improvement rate per additional joint point 33 added by the optimization analysis (dots) No difference was found between Invention Example, Comparative Example 1 and Comparative Example 2 in both cases.

  Next, an optimization analysis is performed in consideration of the inertial force acting on the rotating door component in the running state of the automobile, and the position of the additional joint point where the mass setting corresponding to the rotating door component is selected by the optimization analysis The effect on the rigidity of the car body was examined.

  First, assuming that the vehicle in a running state changes lanes, as shown in FIG. 16A, four load points are set at the subframe mounting position on the front side of the vehicle body, and each load point is set. An optimization analysis of additional joints was performed when a load of 1000 N was applied. Here, the rigidity of the vehicle body calculated in the optimization analysis was evaluated by a value obtained by dividing the load applied to the load point by the displacement at each load point.

  Similar to the above-described static torsion, an optimization analysis model 51 (invention example) in which a mass element 41 corresponding to the mass of a rotating door component is set in the vehicle body skeleton model 21, and an optimization analysis model 61 (invention example) in which no mass is set. Comparison example 1) and optimization analysis model 71 (comparative example 2) in which the car body skeleton model 21 is combined with the revolving door component model 73 were set as the analysis targets.

  17 and 18 show the result of the additional joint point 33 selected by the optimization analysis (additional joint point = 600 points). 17 (a) and 18 (a) are invention examples, FIG. 17 (b) and FIG. 18 (b) are comparative examples 1, and FIG. 17 (c) and FIG. 18 (c) are analytical results in comparative example 2. FIG. 17D and FIG. 18D show load constraint conditions in the optimization analysis.

17 and 18, when the invention example and comparative example 2 in which the mass is set are compared with the comparative example 1 in which the mass is not set, in the upper part of the center pillar and the side sill of the vehicle body, There was a difference.
On the other hand, when the inventive example and the comparative example 2 were compared, almost no difference was found in the positions of the selected joining points. Therefore, it has been shown that by setting the mass element 41 having a mass corresponding to the rotating door component, the inertial force acting on the rotating door component during traveling can be evaluated with high accuracy.

  FIG. 19 shows the results of the rigidity improvement rate of the invention example, comparative example 1 and comparative example 2, and the rigidity improvement rate per point of the additional joint 33 selected by the optimization analysis. Similar to the static torsion described above, the rigidity improvement rate is a relative change in the average torsional rigidity obtained on the basis of the average torsional rigidity of the vehicle body skeleton model 21 before performing the optimization analysis.

As shown in FIG. 19A, in any of the invention example, comparative example 1 and comparative example 2, the rigidity improved as the additional joint point 33 increased.
Furthermore, as shown in FIG. 19 (b), the smaller the additional joint points 33, the higher the rigidity improvement rate (dot efficiency) per point, and the selection of the additional joint points 33 by the optimization analysis method according to the present invention. Indicates that this is being done properly.

  Further, comparing the invention example in which the mass of the rotating door component is set and the comparative example 2 and the comparative example 1 in which the mass is not set, the invention example and the comparative example 2 are improved in rigidity by adding an additional joint point by optimization analysis. The result was high. Moreover, the rigidity improvement rate of the invention example which set mass and the comparative example 2 was substantially equivalent.

20 and 21 show the vehicle body strain energy distribution obtained in the optimization analysis and the analysis result of the additional joint 33 selected by the optimization analysis.
Here, FIGS. 20 and 21 show strain energy distributions with different viewpoints for the region where the rotating door component on the front side of the vehicle body is fixed and connected, and FIGS. 20 (a) and 21 (a). FIG. 20B and FIG. 21B show the analysis results in Comparative Example 1 in which no mass was set.

  20 and 21, compared with Comparative Example 1, in the invention example, the portion (the broken line in the figure) in the vicinity of the fixed coupling portion 23 (hinge 23 a and striker 23 c) to which the mass element 41 is connected via the rigid element 45. In the region, the strain energy is high, and it can be seen that more additional joints 33 are selected by the optimization analysis in the region.

  Furthermore, as another aspect of the load acting when the automobile is running, as shown in FIG. 16 (b), a vertical upward load (1000N) is applied to one of the front suspension mounting positions (A in the figure) of the vehicle body, and the other The position of the additional joint added for the purpose of improving the rigidity of the car body was obtained by optimization analysis.

22 and 23 show the result of the additional joint point 33 selected by the optimization analysis (additional joint point = 600 points).
22 (a) and 23 (a) are the invention examples, FIG. 22 (b) and FIG. 23 (b) are the comparative examples 1, and FIG. 22 (c) and FIG. FIG. 22D and FIG. 23D show load constraint conditions in the optimization analysis.

  22 and 23, when the invention example and comparative example 2 in which the mass is set are compared with the comparative example 1 in which the mass is not set, the positions of the selected additional joint points 33 at the center pillar center portion and the rear pillar of the vehicle body There was a difference.

  On the other hand, when the invention example and the comparative example 2 were compared, almost no difference was found in the position of the selected additional joint point 33. Therefore, it has been shown that by setting the mass element 41 having a mass corresponding to the rotating door component, the inertial force acting on the rotating door component during traveling can be evaluated with high accuracy.

  In FIG. 24, the rigidity improvement rate in the example of invention, the comparative example 1 and the comparative example 2 and the rigidity improvement rate per point of the additional joining point 33 selected by the optimization analysis are shown. Similar to the static torsion described above, the rigidity improvement rate is a relative change in the average torsional rigidity obtained on the basis of the average torsional rigidity of the vehicle body skeleton model 21 before performing the optimization analysis.

As shown in FIG. 24A, in any of the invention example, comparative example 1 and comparative example 2, the rigidity improved as the number of additional joint points 33 selected by the optimization analysis increased.
Furthermore, as shown in FIG. 24 (b), the smaller the number of additional joints 33, the higher the rigidity improvement rate (spot efficiency) per point, and the additional joints 33 obtained by the optimization analysis method according to the present invention. This means that the selection of is properly performed.

  Furthermore, when comparing the invention example in which the mass is set and the comparative example 2 and the comparative example 1 in which the mass is not set, the invention example and the comparative example 2 have a high improvement in rigidity due to the additional joint 33 selected by the optimization analysis. It became. Moreover, the rigidity improvement rate of the invention example in which the mass is set and the comparative example 2 are substantially the same, and in the optimization analysis method according to the present invention, the mass corresponding to the rotary door component is set to set the rotary door configuration. It was shown that the inertial force acting on the parts can be considered with high accuracy.

  As described above, a vehicle body skeleton model having a joint point for joining a plurality of parts as a part set and a fixed connecting part for fixing or connecting a fitting or a lid by the method for optimizing the joining position of the car body according to the present invention. , The joint candidate to be added to the part to be joined as the part set and the mass corresponding to the fitting or the lid are set, and an additional joint point that maximizes the rigidity of the vehicle body skeleton model is selected from the joint candidates. By performing the optimization analysis in consideration of the inertial force acting on the fitting or lid when the automobile is running, the rigidity of the automobile during running can be improved even before the fitting or lid is determined. It has been proved that the optimum additional junction point can be obtained efficiently.

DESCRIPTION OF SYMBOLS 1 Optimization analyzer 3 Display apparatus 5 Input device 7 Storage device 9 Work data memory 10 Arithmetic processing part 11 Optimization analysis model production | generation part 13 Optimization analysis condition setting part 15 Optimization analysis part 20 Body frame model file 21 Body frame Model 23 Fixed connection part 23a Hinge (upper side)
23b Hinge (lower side)
23c Striker 25 Joint point 27 Parts 31 Joint candidate 33 Additional joint point (after optimization analysis)
35 Elimination junction (after optimization analysis)
41 Mass Element 45 Rigid Body Element 47 Beam Element 51 Optimization Analysis Model 61 Optimization Analysis Model (Comparative Example 1)
71 Optimization Analysis Model (Comparative Example 2)
73 Revolving door component model

Claims (14)

An automobile having a plurality of parts composed of a planar element and / or a three-dimensional element, and having a joint point or joint part for joining the plurality of parts as a part set and a fixed connection part for fixing or connecting a fitting or a lid. Using the vehicle body skeleton model, the optimization analysis of the point joint or continuous joint used for joining the component set is a method for optimizing the joint position of the vehicle body in which the computer performs the following steps,
The computer sets an additional joint point to be joined to the part set or a joint candidate for the additional joint, and a mass corresponding to a fitting or a lid in the vehicle body skeleton model, and is set as an analysis target for optimization analysis. An optimization analysis model generation step for generating an optimization analysis model;
An optimization analysis condition setting step in which the computer sets an optimization analysis condition for the optimization analysis model in accordance with an operator's instruction;
The computer performs an optimization analysis on the optimization analysis model in consideration of an inertial force acting when the vehicle is running, and selects an additional joint point or an additional joint that satisfies the optimization analysis condition from the joint candidates. And an optimization analysis step to
In the optimization analysis model generation step, the mass is set at a predetermined position in a region where the fitting or lid is fixed or connected, and the joining candidate is preliminarily set in each part set of the vehicle body skeleton model. A method for optimizing a joint position of a vehicle body, wherein the joint point is set at a predetermined interval between set joint points or joints.   2. The method for optimizing a joint position of vehicle bodies according to claim 1, wherein the predetermined position in the optimization analysis model generation step is set on a straight line or a curve connecting the fixed connecting portions.   In the case where the fitting or the lid is a rotationally movable part that is rotatable, the predetermined position is set to a position excluding a rotationally movable central axis when the fitting or the lid is rotationally movable. Item 3. The method for optimizing the joining position of vehicle bodies according to Item 2.   2. The predetermined position in the optimization analysis model generation step is set on a plane or a curved surface (excluding the straight line or curved line) surrounded by a straight line or a curve connecting the fixed coupling portions. The optimization analysis method of the joining position of the vehicle body described.   In the optimization analysis model generation step, a mass corresponding to a mass of the fitting or the lid is set using a mass element and a rigid element that connects the mass element and the fixed coupling portion. The optimization analysis method of the joining position of the vehicle body as described in any one of Claims 1 thru | or 4.   The optimization analysis model generation step is set using a mass element and a beam element, and the sum of the mass of the mass element and the beam element corresponds to the mass of a fitting or lid fixed or connected to the fixed connection portion. The optimization analysis method of the joining position of the vehicle body as described in any one of Claims 1 thru | or 4 characterized by the above-mentioned.   5. The vehicle body joining according to claim 1, wherein the optimization analysis model generation step is set by using a beam element having a mass corresponding to a mass of the fitting or the lid. Location optimization analysis method. An automobile having a plurality of parts composed of planar elements and / or three-dimensional elements, and having a joint point or joint part for joining the plurality of parts as a part set, and a fixed connection part for fixing or connecting a fitting or a lid. Using a vehicle body skeleton model, an optimization analysis device of a joint position of a vehicle body that optimizes point joining or continuous joining used for joining the component set,
Optimization analysis that sets additional joint points or additional joint candidates to be joined in addition to the parts set and mass corresponding to fittings or lids to the body frame model, and is an analysis target of optimization analysis An optimization analysis model generation unit for generating a model;
An optimization analysis condition setting unit for setting optimization analysis conditions for the optimization analysis model;
An optimization analysis is performed for the optimization analysis model in consideration of an inertial force acting when the vehicle is running, and an optimization is performed in which additional joint points or additional joints satisfying the optimization analysis condition are selected from the joint candidates. With an analysis unit,
The optimization analysis model generation unit sets the mass to a predetermined position in a region where the fitting or lid is fixed or connected, and the joining candidate is preliminarily set in each part set of the vehicle body skeleton model. An apparatus for optimizing a joint position of a vehicle body, wherein the joint position is set at a predetermined interval between set joint points or joint parts.   9. The apparatus for optimizing a joint position of vehicle bodies according to claim 8, wherein the predetermined position of the mass set by the optimization analysis model generation unit is on a straight line or a curve connecting the fixed connecting portions. .   In the case where the fitting or the lid is a rotationally movable part that is rotatable, the predetermined position is set to a position excluding a rotationally movable central axis when the fitting or the lid is rotationally movable. Item 10. An apparatus for optimizing the joining position of vehicle bodies according to Item 9.   The predetermined position of the mass set by the optimization analysis model generation unit is set on a plane or a curved surface (except on the straight line or curved line) surrounded by a straight line or a curve connecting the fixed connection portions The apparatus for optimizing the joining position of vehicle bodies according to claim 8.   The optimization analysis model generation unit sets a mass corresponding to a mass of the fitting or the cover using a mass element and a rigid element that connects the mass element and the fixed coupling unit. The optimization analysis apparatus of the joining position of the vehicle body as described in any one of Claims 8 thru | or 11.   The optimization analysis model generation unit is set using a mass element and a beam element, and the sum of the mass of the mass element and the beam element corresponds to the mass of the fitting or lid fixed or connected to the fixed connection unit. The apparatus for optimizing the joining position of the vehicle body according to any one of claims 8 to 11, characterized in that:   The vehicle body joining according to any one of claims 8 to 11, wherein the optimization analysis model generation unit is set using a beam element having a mass corresponding to a mass of the fitting or the lid. Position optimization analyzer.