JP4662255B2 - Optimal design system - Google Patents

Description

  The present invention relates to an optimum design system.

  In order to suppress the vibration of the vehicle body due to the vibration of the vehicle engine, an anti-vibration mount is disposed between the vehicle engine and the vehicle body. The position of the vibration-proof mount is, for example, placing importance on the center of gravity of the vehicle engine or on the inertia main axis of the vehicle engine. Then, after determining the arrangement position, the spring constant of the anti-vibration mount is determined (for example, see Patent Documents 1 and 2).

By the way, an optimization design using a computer is used to determine an arrangement position of the vibration-proof mount and the like. For example, Patent Document 3 describes performing optimization calculation of design variables so that the vibration level is minimized with the arrangement position of the vibration-proof mount and the spring constant as design variables (parameters).
Japanese Utility Model Publication No. 5-29825 Japanese Utility Model Publication No. 6-28380 JP-A-6-89322

  Here, in the optimization design described in Patent Document 3, it is considered that the number of anti-vibration mounts is determined in advance, and the optimum positions of the anti-vibration mounts and the spring constants are calculated. That is, the number of anti-vibration mounts is not changed.

  However, the optimal number of anti-vibration mounts that minimize the vibration level is not always constant due to the shape of the vehicle engine and the vehicle body and other various factors. Furthermore, even in a vehicle equipped with the same type of vehicle engine, the number of vibration-proof mounts may change depending on the target vibration level.

  The present invention has been made in view of such circumstances, and it is possible to determine the optimum arrangement position and optimum spring constant of the vibration-proof mount while allowing the number of vibration-proof mounts to be changed. The purpose is to provide a design system.

  Therefore, the present inventor has intensively studied to solve this problem, and as a result of repeated trial and error, the present inventor has conceived that an objective value relating to the number of anti-vibration mounts is included in the objective function, and has completed the present invention.

  In other words, the optimum design system of the present invention is optimally designed to design the optimum arrangement position of the anti-vibration mount that is interposed between the structure and the support member and suppresses the support member from vibrating due to the vibration of the structure. The design system includes an initial value setting unit that sets an initial value of a spring constant of a plurality of vibration isolation mounts that are virtually arranged, and a first related to vibration of a support member caused by vibration of a structure using the spring constant as a parameter. A first target value calculation unit that calculates a target value of the second, a second target value calculation unit that calculates a second target value related to the number of anti-vibration mounts using the spring constant as a parameter, a first target value, and a first target value An objective function calculation unit that calculates an objective function based on the objective value of 2, a sensitivity calculation unit that calculates the sensitivity of each spring constant in the objective function, and an optimal solution for each spring constant so that the objective function is minimized based on the sensitivity. To calculate A solution calculating unit, characterized in that it comprises a determining unit for determining an optimal spring constant of the optimal position and vibration damping mount of the vibration damping mount based on the optimal solution.

  Here, the objective function is, for example, a function obtained by adding objective values such as the first objective value and the second objective value. The optimum solution calculated by the optimum solution calculation unit is composed of spring constants that minimize the objective function. That is, the optimal solution calculation unit performs optimization calculation for calculating each spring constant such that the objective function is minimized. Here, the case where the objective function is minimized is a case where each objective value such as the first objective value and the second objective value becomes small. That is, the optimal solution results in each spring constant such that the first target value, the second target value, and the like also decrease each target value. If the objective function multiplies each objective value such as the first objective value and the second objective value by a different weighting factor, the weighting of each objective value can be made different.

  The second target value is a target value related to the number of anti-vibration mounts. That is, the number of anti-vibration mounts is reduced by performing the optimization calculation by the optimal solution calculation unit. Accordingly, when focusing on the number of anti-vibration mounts, the optimum design system of the present invention performs optimization calculation with a state in which a plurality of (many) anti-vibration mounts are virtually arranged as an initial state. This is a system that performs processing to reduce the number. That is, the position and spring constant of the vibration-proof mount that are finally left after the optimization calculation are the optimum position and spring constant of the vibration-proof mount.

  Thus, according to the optimum design system of the present invention, the number of vibration-proof mounts, the arrangement position, and the spring constant can be changed. That is, according to the optimum design system of the present invention, it is possible to calculate the optimal position and spring constant of the anti-vibration mount in consideration of the vibration of the support member, and the optimal number of anti-vibration mounts.

  Here, the initial value setting unit in the optimum design system of the present invention may set initial values of spring constants of a plurality of vibration-proof mounts virtually arranged around the entire structure. Thereby, the optimal arrangement position of the vibration proof mount can be examined without omission with respect to the entire periphery of the structure.

  Further, the initial value setting unit divides the formation surface of the virtual region surrounding the structure into a lattice shape, and sets the initial value of the spring constant of the plurality of vibration isolation mounts virtually disposed at each lattice point. Also good. In other words, the anti-vibration mount is arranged at each lattice point on the formation surface of the virtual region. Thereby, the calculation regarding the arrangement position of the anti-vibration mount can be performed very easily.

  The anti-vibration mount spring constant may be the spring constant in the three orthogonal axes of the anti-vibration mount, and the optimal spring constant may be the optimal spring constant in the three-axis orthogonal direction of the anti-vibration mount. Thereby, it can apply to the anti-vibration mount which has a spring constant of an orthogonal three-axis direction. For example, when the structure is a vehicle engine, the three orthogonal directions of the anti-vibration mount are the vehicle up-down direction, the vehicle left-right direction, and the vehicle front-rear direction.

  In addition, the second target value calculated by the second target value calculation unit may be the number in which the spring constant of the vibration-proof mount larger than the second threshold value exists. For example, when the spring constant of the vibration isolating mount is only the spring constant in one direction of the vibration isolating mount, the second target value substantially corresponds to the number of vibration isolating mounts. Further, when the spring constant of the vibration proof mount is set to be the spring constant in each of the three orthogonal directions of the vibration proof mount, there are three spring constants for one vibration proof mount. In this case, the second target value corresponds to the number of spring constants larger than the second threshold value. Thus, the second target value is calculated by comparing the spring constant and the second threshold value. That is, it is possible to easily perform optimization calculation for the number of anti-vibration mounts.

  Further, the second target value calculated by the second target value calculation unit may be calculated according to Equation 1 in addition to the above case.

  Here, according to Equation 1, the second target value OBJN represents a number related to the number of anti-vibration mounts. For example, when the spring constant of the anti-vibration mount is only one direction spring constant of the anti-vibration mount, the second target value OBJN substantially corresponds to the number of anti-vibration mounts. Further, when the spring constant of the vibration proof mount is set to be the spring constant in each of the three orthogonal directions of the vibration proof mount, there are three spring constants for one vibration proof mount. That is, in this case, the second target value OBJN corresponds to the number of spring constants.

Specifically, according to _Equation 1, when k _n is much larger than k _{limit, the} anti-vibration mount spring constant k _n is counted as one, and when k _n is much smaller than k _limit. not counting the spring constant k _n of the vibration damping mount. When k _n is in the vicinity of k _limit , the count number of the spring constant of the anti-vibration mount is continuously changed according to the magnitude. As a result, the optimization calculation for the number of anti-vibration mounts can be reliably performed, and the optimization calculation can be stably processed.

  The determination unit in the optimal design system of the present invention may use the vibration isolating mount placement position and the spring constant whose optimum solution is larger than the third threshold as the vibration damping mount optimum placement position and the optimal spring constant. That is, the spring constant of the vibration isolating mount whose optimum solution for the spring constant is the third threshold value or less is recognized as zero. Then, only the spring constant of the vibration isolating mount whose optimum solution of the spring constant is larger than the third threshold value is extracted as necessary. As a result, the necessary anti-vibration mount can be extracted reliably and easily.

  The optimum design system of the present invention further includes a third objective value calculation unit that calculates a third objective value related to the distance of each vibration isolation mount using the spring constant as a parameter, and the objective function calculation unit includes: An objective function may be calculated based on the third objective value. That is, the objective function calculation unit calculates the objective function based on at least the first objective value, the second objective value, and the third objective value.

  Here, for example, when focusing on two anti-vibration mounts, if the distance between these anti-vibration mounts is large, it is determined that both of these anti-vibration mounts should exist independently of each other. On the other hand, when the distance between these anti-vibration mounts is small, the roles of both of them may be common. In this case, two anti-vibration mounts with a small distance may be combined into one. Therefore, by including the third objective value relating to the distance between the anti-vibration mounts in the term of the objective function, it is possible to calculate the optimum solution while taking into account the distance between the anti-vibration mounts. Thereby, it can contribute to reducing the number of anti-vibration mounts.

  Note that the third target value may be a large value when the distance between the two selected vibration-proof mounts is smaller than the predetermined distance. Thereby, it is possible to surely combine two adjacent vibration-proof mounts into one.

  The third target value may be set to a larger value as the distance between the two selected vibration-proof mounts is smaller than the predetermined distance and closer to the predetermined distance. As a result, the third target value when the distance between the two anti-vibration mounts is in the vicinity of the predetermined distance is increased. Therefore, the distance between the two anti-vibration mounts is smaller than the predetermined distance and closer to the predetermined distance. The two anti-vibration mounts can be combined into one.

  In addition, the third target value may be a large value according to the number of times the optimal solution calculation unit calculates the optimal solution. Here, the number of anti-vibration mounts is not necessarily reduced by one calculation of the optimal solution by the optimal solution calculation unit. For example, even when the optimal solution is temporarily calculated (when the objective function is minimized), there may be a plurality of anti-vibration mounts, for example, at close positions. In such a case, it is necessary to calculate an optimal solution that further reduces the number of anti-vibration mounts. Therefore, by setting the third target value to a large value according to the number of times of calculating the optimum solution, the calculation of the optimum solution can be resumed so that a plurality of adjacent anti-vibration mounts are combined into one. Thereby, the number of anti-vibration mounts can be further reduced.

  In addition, the sensitivity calculation unit in the optimum design system of the present invention may calculate the sensitivity of each spring constant in the objective function when each spring constant is changed by a predetermined amount. As a result, the optimum solution for the spring constant can be easily calculated by the optimum solution calculator.

  The optimum design system of the present invention further includes a fourth objective value calculation unit that calculates a fourth objective value related to the spring ratio of each vibration isolation mount using the spring constant as a parameter, and the objective function calculation unit includes: The objective function may be calculated based on the fourth objective value. That is, the objective function calculation unit calculates the objective function based on at least the first objective value, the second objective value, and the fourth objective value.

  Here, for example, when the anti-vibration mount has a spring constant in three orthogonal directions (X direction, Y direction, Z direction), the spring ratio is the ratio of the spring constant in the X direction to the spring constant in the Z direction, or , The ratio of the spring constant in the Y direction to the spring constant in the Z direction. Then, by making the spring ratio of the vibration-proof mount within a predetermined range, it is possible to facilitate the manufacture of the vibration-proof mount. That is, the manufacturing cost of the vibration isolating mount can be reduced by taking the fourth target value into consideration.

  The structure in the optimum design system of the present invention may be a vehicle engine, and the support member may be an engine frame or a vehicle body. That is, the optimum design system of the present invention can be applied to the optimum design of the vibration isolating mount for the vehicle engine.

  In this case, the first target value may be a target value related to any one selected from idle vibration, engine shake, and engine movement amount of the vehicle engine. Here, the idle vibration is vibration transmitted from the vehicle engine to the engine frame or the vehicle body when the vehicle engine is driven. The engine shake is, for example, when the vibration frequency transmitted from the outside of the vehicle to the engine frame or the vehicle body via wheels or the like is near the resonance frequency of the vehicle engine and the vibration isolation mount. This is the vibration that occurs. The engine movement amount is a swing angle when the vehicle engine swings around a predetermined axis when the vehicle engine is driven. That is, by setting the first target value as described above, it is possible to determine the optimal placement position of the vibration-proof mount so as to reduce the influence of the selected cause of vibration.

  According to the optimum design system of the present invention, the number of vibration-proof mounts, the arrangement position, and the spring constant can be changed. That is, according to the optimum design system of the present invention, it is possible to calculate the optimal position and spring constant of the anti-vibration mount in consideration of the vibration of the support member, and the optimal number of anti-vibration mounts.

  Next, the present invention will be described in more detail with reference to embodiments. In the present embodiment, the case where the optimum design system of the present invention is used for the optimum design of the vibration isolating mount 3 disposed between the vehicle engine 2 and the vehicle body 1 will be described as an example. That is, the optimum arrangement position and the optimum spring constant of the vibration-proof mount 3 are determined by the optimum design system in the present embodiment.

(1) Model Overview First, an overview of the model of the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing an outline of a model of the present embodiment. Here, in FIG. 1, the left side is called the vehicle front side, the right side is called the vehicle rear side, the front side is called the vehicle left side, the back side is called the vehicle right side, the upper side is called the vehicle upper side, and the lower side is the vehicle lower side. Called the side.

  As shown in FIG. 1, a vehicle engine (a structure in the present invention) 2 is supported on a vehicle body (a support member in the present invention) 1 via a vibration-proof mount 3. That is, the anti-vibration mount 3 is a member for suppressing the vehicle body 1 from vibrating due to the vibration of the vehicle engine 2. Further, the vehicle body 1 is supported with respect to the ground by wheels and a suspension 4.

(2) Configuration of Optimal Design System Next, the configuration of the optimal design system will be described with reference to FIG. 2 and FIG. FIG. 2 is a block diagram showing the optimum design system. FIG. 3 is a diagram for explaining a virtual arrangement position of the image stabilizing mount 3.

  As shown in FIG. 2, the optimum design system includes a specification input unit 11, an initial value setting unit 12, an objective value calculation unit 13, an objective function calculation unit 14, a sensitivity calculation unit 15, and an optimal solution calculation unit. 16 and an output unit 17.

  The specification input unit 11 inputs each specification of the vehicle. The specifications of the vehicle are, specifically, specifications related to the vehicle engine 2, specifications related to the vehicle body 1, inertia specifications of the suspension 4, spring specifications of the suspension 4, and the like.

  The initial value setting unit 12 sets an initial value of the spring constant of the anti-vibration mount 3. The anti-vibration mounts 3 that are targets of initial value setting are the anti-vibration mounts 3 that are virtually arranged around the vehicle engine 2. Further, the anti-vibration mount 3 has spring constants in three orthogonal directions, that is, a vehicle longitudinal direction (X direction), a vehicle left-right direction (Y direction), and a vehicle vertical direction (Z direction).

  Here, the anti-vibration mount 3 that is the target of the initial value setting will be specifically described with reference to FIG. Here, FIG. 3A is a plan view of the vehicle engine 2 shown in FIG. 1 as viewed from above, and FIG. 3B is a rear view of the vehicle engine 2 shown in FIG. FIG. As shown in FIGS. 3A and 3B, first, a virtual region surrounding the entire periphery of the vehicle engine 2 is set. This virtual area is, for example, a rectangular parallelepiped. For example, the virtual area may have a shape corresponding to an engine frame (not shown) fixed to the vehicle body 1. Then, the formation surface (here, 6 surfaces) of the virtual region is divided into a lattice shape, and the anti-vibration mount 3 is virtually disposed at each lattice point. Then, as shown in Formula 2, spring constants k in the vehicle front-rear direction, the vehicle left-right direction, and the vehicle vertical direction of the plurality of vibration isolation mounts 3 that are virtually arranged are set. Here, the maximum number of virtual anti-vibration mounts 3 is NMT. That is, the number of lattice points is NMT. In Equation 2, the first subscript indicates the number of each grid point, that is, the number of the image stabilization mount 3 virtually arranged at each grid point, and the second subscript is the X direction, Y Direction and Z direction. Hereinafter, for ease of explanation, the second subscript is 1 in the X direction, 2 in the Y direction, and 3 in the Z direction.

  The target value calculation unit 13 receives each specification input to the specification input unit 11 and the spring constant k set by the initial value setting unit 12 or the spring constant k updated by the optimum solution calculation unit 16 described later. Use to calculate six target values. Specifically, the target value calculation unit 13 includes a spring constant matrix calculation unit 21, a first target value calculation unit 22, a second target value calculation unit 23, a third target value calculation unit 24, and a fourth purpose. The value calculation unit 25, the fifth target value calculation unit 26, and the sixth target value calculation unit 27 are configured. Here, each objective value represents each term of an objective function described later. That is, each objective value is used for calculating an objective function.

Spring constant matrix calculating unit 21 calculates according to Equation 3 the stiffness matrix K _e of the spring constant of the vibration damping mount 3. The stiffness matrix K _e of the spring constant of the vibration damping mount 3 correspond to those obtained by replacing a plurality of vibration damping mount 3 in a single vibration damping mount 3 relative to the center of gravity of the vehicle engine 2.

The first target value calculation unit (first target value calculation unit in the present invention) 22 is for each specification, the initial value or the updated value of the spring constant k of the vibration isolation mount 3, and the spring constant of the vibration isolation mount 3. Using the stiffness matrix K _e , the target value OBJI related to idle vibration is calculated according to Equation 4. That is, the target value OBJI relating to idle vibration uses the spring constant k of the vibration isolating mount 3 as a parameter. The idle vibration is vibration transmitted from the vehicle engine 2 to the vehicle body 1 through the vibration isolation mount 3 when the vehicle engine 2 is driven. Then, the target value OBJI relating to idle vibration becomes smaller as the vibration transmitted to the vehicle body 1 when the vehicle engine 2 is driven becomes smaller.

(First target value calculating unit in the present invention) 23 second target value calculation unit, by using the stiffness matrix K _e of each parameter and the spring constant of the vibration damping mount 3, target value relating to engine shake according to Equation 5 OBJS Is calculated. That is, the target value OBJS relating to the engine shake uses the spring constant k of the vibration-proof mount 3 as a parameter. The engine shake is, for example, when the vibration frequency transmitted from the outside of the vehicle to the vehicle body 1 via the wheels, the suspension 4 and the like is near the resonance frequency of the vehicle engine 2 and the vibration isolation mount 3. This is a vibration that occurs in The target value OBJS relating to the engine shake becomes smaller as the vibration generated in the vehicle body 1 due to the engine shake is smaller. Note that in Equation 5, the all # K, contains a stiffness matrix K _e of the spring constant of the vibration damping mount 3.

The third target value calculating section (first target value calculating unit in the present invention) 24, using the stiffness matrix K _e of each parameter and the spring constant, and calculates the target value OBJR an engine movement amount according to Equation 6. That is, the target value OBJR relating to the engine movement amount uses the spring constant k of the vibration isolating mount 3 as a parameter. The engine movement amount is a swing angle when the vehicle engine swings around a predetermined axis when the vehicle engine is driven. The target value OBJR related to the engine movement amount becomes smaller as the engine movement amount is smaller. The case where the engine movement amount is small means that the vibration of the vehicle body 1 due to the swing of the vehicle engine is small.

  The fourth target value calculation unit (fourth target value calculation unit in the present invention) 25 uses each specification and the initial value or the updated value of the spring constant k to calculate the target value OBJH related to the spring ratio according to Equation 7. calculate. That is, the target value OBJH relating to the spring ratio uses the spring constant k of the vibration isolating mount 3 as a parameter. Here, the spring ratio is the ratio of the spring constant in the X direction to the spring constant in the Z direction of the vibration isolation mount 3 or the ratio of the spring constant in the Y direction to the spring constant in the Z direction of the vibration isolation mount 3. According to Equation 7, the target value OBJH relating to the spring ratio is a target value for setting each spring ratio between a and b. The target value OBJH related to the spring ratio becomes smaller as the respective spring ratio is between a and b. In addition, by making the spring ratio within a predetermined range, it is possible to facilitate manufacture and generalization of the vibration-proof mount 3.

The fifth target value calculation unit (second target value calculation unit in the present invention) 26 calculates the target value OBJN related to the number of anti-vibration mounts 3 according to Equation 8 using the initial value or the updated value of the spring constant k. . That is, the target value OBJN relating to the number of the anti-vibration mounts 3 uses the spring constant k of the anti-vibration mounts 3 as a parameter. According to Equation 8, the target value OBJN about the number of vibration damping mount 3, the spring constant k _ni 1 bract counted when the spring constant k _ni is much greater than the prestored threshold k _limit, the spring constant k _{If ni} is much smaller than the threshold k _limit , the spring constant k _ni is not counted. Furthermore, when the spring constant k _ni is in the vicinity of the threshold k _limit , the spring constant is continuously changed as the count number in which the spring constant exists. That is, the target value OBJN relating to the number of anti-vibration mounts 3 corresponds to the number of spring constants k _ni that are substantially larger than the threshold value k _limit . That is, the target value OBJN related to the number of anti-vibration mounts 3 becomes smaller as the spring constant k _ni larger than the threshold value k _limit decreases.

The sixth target value calculation unit (third target value calculation unit in the present invention) 27 calculates the target value OBJL related to the distance of the vibration isolating mount 3 according to Equation 9 using the initial value or the updated value of the spring constant k. . That is, the target value OBJL related to the distance of the vibration proof mount 3 uses the spring constant k of the vibration proof mount 3 as a parameter. According to Equation 9, the target value OBJL related to the distance of the anti-vibration mount 3 is predetermined when the distance R _mn between the selected anti-vibration mount m and the anti-vibration mount n is smaller than the preset stored distance R _d. It is trying to become the value of. On the other hand, when the distance R _mn between the selected anti-vibration mount m and the anti-vibration mount n is equal to or greater than the set distance R _d , the value is zero. And the thing added about all the anti-vibration mounts 3 is made into the said target value OBJL.

Here, when the distance R _mn between the selected anti-vibration mount m and the anti-vibration mount n is smaller than the set distance R _d , the roles of both are almost the same. Therefore, when the distance R _mn is smaller than the set distance R _d , it is considered that both can be combined into one. On the other hand, when the distance R _mn between the selected anti-vibration mount m and the anti-vibration mount n is equal to or _larger than the set distance R _d , it is considered that they should exist independently of each other. Accordingly, the target value OBJL is set to a predetermined value only when the distance R _mn between the selected vibration-proof mount m and the vibration-proof mount n is smaller than the set distance R _d . That is, as there is nothing two vibration damping mount 3 selected smaller than the set distance R _d, the target value OBJL becomes a small value.

Further, in a case the distance R _mn of the vibration damping mount m and vibration damping mount n selected is less than the set distance R _d, as the distance R _mn is close to the set distance R _d, the target value OBJL large Value. This is because even if the distance R _mn of the two anti-vibration mounts 3 selected is less than the set distance R _d, as the distance R _mn is far from the set distance R _d, the target value OBJL is a small value Become. In other words, in order to reduce the target value OBJL when the distance between the two selected anti-vibration mounts 3 is smaller than the set distance R _d , the distance R _mn between the two anti-vibration mounts 3 is reduced as much as possible. That is, it is necessary to combine the two anti-vibration mounts 3 into one. That is, the target value OBJL is a target value for causing the number of anti-vibration mounts 3 to further decrease.

  Further, the target value OBJL relating to the distance of the vibration isolating mount 3 is made to differ according to the number of times num of optimum solution calculations in the optimum solution calculation unit 16. Specifically, the target value OBJL increases exponentially as the optimal solution calculation count num increases. That is, the contribution of the target value OBJL increases as the number of times num for calculating the optimum solution increases. The optimal solution calculation count num increases when the optimal solution is calculated by the optimal solution calculation unit 16 and in a predetermined case described later.

  The objective function calculator 14 calculates the objective function OBJ according to Equation 10 using each objective value. That is, the objective function OBJ is obtained by adding a value obtained by multiplying each objective function by the weighting coefficient α.

The sensitivity calculation unit 15 calculates the sensitivity S according to Equation 11. Here, the sensitivity S means the sensitivity of each spring constant k in the objective function OBJ when the spring constant k is changed by a minute amount. Specifically, a value obtained by dividing the difference between the objective function OBJ calculated by the objective function calculation unit 14 and the objective function OBJ ₁₁ when the spring constant k is changed by a minute amount by the fluctuation amount of the spring constant k. It is. Note that the sensitivity calculation unit 15 calculates the sensitivity S when each spring constant k is varied.

  The optimal solution calculation unit 16 performs optimization calculation using the Armijo method as a one-dimensional search. As a constraint, the gradient projection method is used so that the total value of all the spring constants k is zero or more. Specifically, the optimal solution calculation unit 16 updates the spring constant k according to Equation 12 based on the sensitivity S calculated by the sensitivity calculation unit 15. Then, optimization calculation is performed so that the objective function OBJ is minimal, that is, the amount of change in the objective function OBJ is zero. That is, the target value calculation unit 13 calculates each target value using the updated spring constant k, and the calculation of the target function OBJ and the sensitivity S is repeated again. Furthermore, even when the amount of change in the objective function OBJ becomes zero, the optimal solution calculation unit 16 performs recalculation when the number N of the image stabilizing mounts 3 is equal to or greater than the predetermined value Nth. . In this way, the optimal solution calculation unit 16 calculates the optimal solution for the spring constant k. In the optimum solution of the spring constant k calculated in this way, most of the anti-vibration mounts 3 have a spring constant k near zero, and some of the anti-vibration mounts 3 have large spring constants k.

  The output unit (determining unit in the present invention) 17 determines and outputs the optimum arrangement position and the optimum spring constant of the vibration isolating mount 3 based on the optimum solution of the spring constant k calculated by the optimum solution calculating unit 16. Specifically, the optimal solution calculation unit 16 calculates a spring constant k that is larger than a predetermined threshold value, and determines the position of the vibration isolation mount 3 having the extracted spring constant k as the optimal position of the vibration isolation mount 3. Determine with position. Then, the spring constant k of the vibration proof mount 3 is determined as the optimum spring constant of the vibration proof mount 3. Then, the determined optimum arrangement position and optimum spring constant of the vibration isolating mount 3 are output.

(3) Processing Operation of Optimal Design System Next, the processing operation of the optimal design system configured as described above will be described with reference to FIG. FIG. 4 is a flowchart showing the processing operation of the optimum design system.

  As shown in FIG. 4, each specification is first input in the specification input part 11 (step S1). Subsequently, the initial value setting unit 12 sets an initial value of the spring constant k (step S2). Subsequently, each target value is calculated by the target value calculation unit 13 (step S3). Subsequently, the objective function calculation unit 14 calculates the objective function OBJ (step S4). Subsequently, the sensitivity calculation unit 15 calculates the sensitivity S (step S5).

  Subsequently, an optimization calculation is performed by the optimal solution calculation unit 15, and it is determined whether or not the amount of change in the objective function OBJ has become zero (step S6). If the change amount of the objective function OBJ is not zero (step S6: No), the process returns to step S3 again and the process is repeated. On the other hand, when the amount of change in the objective function OBJ becomes zero, that is, when the optimal solution is calculated (step S6: Yes), the optimal solution calculation unit 15 calculates the number N of the vibration isolation mounts 3 ( Step S7). Subsequently, it is determined whether or not the calculated number N of anti-vibration mounts 3 is smaller than a predetermined value Nth (step S8). When the number N of the anti-vibration mounts 3 is equal to or greater than the predetermined value Nth (step S8: No), the sixth objective value calculation unit 27 adds 1 to the number of times of calculating the optimum solution (step S10), and step S3. Return to and repeat the process. On the other hand, when the number N of the anti-vibration mounts 3 is smaller than the predetermined value Nth (step S8: Yes), the output unit 17 determines and outputs the optimal arrangement position and the optimal spring constant of the anti-vibration mounts 3 (step). S17).

  From the above, the optimization calculation can be performed by appropriately changing the number, the arrangement position, and the spring constant of the anti-vibration mount 3 by the optimum design system. That is, it is possible to calculate the optimal position and spring constant of the anti-vibration mount 2 in consideration of the vibration of the vehicle body 1 and the optimal number of anti-vibration mounts 3.

It is a figure which shows the outline | summary of the model of this embodiment. It is a block diagram which shows an optimal design system. It is a figure explaining the virtual arrangement position of anti-vibration mount. It is a flowchart which shows the processing operation of an optimal design system.

Explanation of symbols

1: Vehicle body, 2: Engine for vehicle, 3: Anti-vibration mount, 4: Wheel and suspension

Claims (14)

An optimum design system for designing an optimum arrangement position of a vibration isolating mount that is interposed between a structure and a support member and suppresses vibration of the support member due to vibration of the structure,
An initial value setting unit for setting an initial value of a spring constant of the plurality of vibration isolation mounts virtually arranged;
A first target value calculation unit that calculates a first target value related to the vibration of the support member caused by the vibration of the structure, using the spring constant as a parameter;
A second target value calculation unit that calculates a second target value related to the number of the vibration-proof mounts using the spring constant as a parameter;
An objective function calculator for calculating an objective function based on the first objective value and the second objective value;
A sensitivity calculator for calculating the sensitivity of each spring constant in the objective function;
Based on the sensitivity, an optimal solution calculation unit that calculates an optimal solution of each of the spring constants so that the objective function is minimized,
Based on the optimal solution, a determination unit that determines an optimal arrangement position of the vibration isolation mount and an optimal spring constant of the vibration isolation mount;
An optimal design system characterized by comprising:   The optimal design system according to claim 1, wherein the initial value setting unit sets initial values of spring constants of the plurality of vibration-proof mounts virtually arranged around the entire structure.   The initial value setting unit divides a formation surface of a virtual region surrounding the structure into a lattice shape, and sets an initial value of a spring constant of the plurality of vibration isolation mounts virtually arranged at each lattice point. The optimum design system according to 1. The spring constant is a spring constant in the three orthogonal directions of the vibration-proof mount,
The optimum design system according to claim 1, wherein the optimum spring constant is an optimum spring constant in three orthogonal directions of the vibration-proof mount.   2. The optimum design system according to claim 1, wherein the second target value is a number in which a spring constant of the anti-vibration mount larger than a second threshold exists.   The optimal design system according to claim 1, wherein the determination unit sets the position and the spring constant of the vibration isolation mount whose optimal solution is greater than a third threshold as the optimal position and the spring constant of the vibration isolation mount. . Furthermore, a third target value calculation unit that calculates a third target value related to the distance of each of the anti-vibration mounts using the spring constant as a parameter,
The optimal design system according to claim 1, wherein the objective function calculation unit calculates the objective function based on the third objective value.   The optimal design system according to claim 7, wherein the third target value is a large value when a distance between the two selected vibration-proof mounts is smaller than a predetermined distance.   9. The optimum design system according to claim 8, wherein the third target value becomes a larger value as the distance between the two selected vibration-proof mounts is smaller than the predetermined distance and closer to the predetermined distance.   The optimal design system according to claim 7, wherein the third target value is a large value according to the number of times the optimal solution is calculated by the optimal solution calculation unit.   The optimal design system according to claim 1, wherein the sensitivity calculation unit calculates the sensitivity of each spring constant in the objective function when each spring constant is changed by a predetermined amount. And a fourth target value calculation unit for calculating a fourth target value related to a spring ratio of each of the vibration-proof mounts using the spring constant as a parameter.
The optimal design system according to claim 1, wherein the objective function calculation unit calculates the objective function based on the fourth objective value. The structure is a vehicle engine,
The optimal design system according to claim 1, wherein the support member is an engine frame or a vehicle body.   The optimal design system according to claim 13, wherein the first target value is a target value related to any one selected from idle vibration, engine shake, and engine movement amount of the vehicle engine.

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