JP2006098355A - Frame mechanism vibration analyzing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To analyze vibration of a frame mechanism formed of a top plate having a driving machine requiring positioning and a flexible leg section for supporting the top plate at a less calculation amount and at an analysis accuracy equivalent to a finite element method of producing the strict solution as much as possible by input of the necessary minimum parameters, in which everyone does not rely on the experience or intuition. <P>SOLUTION: The natural frequency of the frame mechanism 13 is calculated using, as input parameters, the width of the leg section 10 constituting the frame mechanism 13, the depth of the leg section 10, the height of the leg section 10, the material characteristic of the leg 10a constituting the leg section 10, the cross-section shape characteristic of the leg 10a, the mass of the top plate 12 supported by the leg 10a, and the mass of the machine 11 on the top plate 12. In other words, because the rigidity of the leg 10a significantly contributes to reduce the error between the model and the actual machine even when the top plate 12 is considered as a rigid body, the natural frequency of the frame mechanism 13 is calculated with small number of input parameters by using a model of sufficiently increasing the rigidity of the top plate 12 compared with the leg 10a and neglecting the influence of the top plate 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gantry mechanism vibration analysis apparatus that simulates vibrations of a gantry mechanism in which a drive machine that requires positioning is installed.

  Conventionally, in designing a mechanical system such as a gantry mechanism, a gantry mechanism in which a driving machine (also referred to as a driving body) is installed is considered as a rigid body and is designed with an emphasis on analysis of the behavior of the driving mechanism. For this reason, the design of the gantry mechanism has been a technique of designing the rigidity as high as possible. However, when the space of the gantry mechanism where the drive body is installed is limited or when it is possible to move, the gantry mechanism is not sufficiently rigid due to the need to reduce the weight of the gantry, and may not be considered a rigid body. It is coming. Furthermore, depending on the magnitude of the reaction force from the drive body, the drive pattern, and the installation state of the mount, vibration of the mount mechanism itself that cannot be ignored may affect the behavior of the drive.

Recently, there is a strong demand for high-speed and high-accuracy positioning, and minute vibrations that have been ignored until now must be taken into consideration. Therefore, not only the analysis of the drive mechanism but also the analysis of the gantry mechanism in which the drive mechanism is installed is necessary to meet these requirements.
Conventionally, when analyzing vibrations of a mechanical system, only a main factor is extracted from complicated factors, and a model with a low degree of freedom as simple as possible is constructed, and if possible, a linear model is constructed. Specifically, as shown in FIG. 15, for example, as an actual mechanism, a vibration model of a mechanism in which the leg 1 with two legs supports the top plate 3 on which the machine 2 is installed is as shown in FIG. A vibration phenomenon is modeled as a vibration model composed of a rigid mass element 4 having an equivalent mass equivalent to that of the machine 2 and the top plate 3, a spring element 5 representing the vibration characteristics, and a damping element 6. The vibration phenomenon was analyzed by calculating.

However, in the analysis method, when the structure to be analyzed is simple, the determination of the spring element 5 is easy and the vibration phenomenon can be reproduced well. However, when the structure is complicated, the characteristics of the model spring element 5 (spring constant) ) And the characteristics (attenuation constant) of the attenuation element 6 are difficult to determine. In order to make up for this, it was necessary to modify the model through experiments and observations, so a great deal of time was wasted.
For this reason, recently, an analysis method called a finite element method has been established as a powerful analysis method. This is because the shape of the analysis target is simply input as data, no special training is required, and anyone can easily calculate the vibration phenomenon and perform highly accurate analysis. It is possible. In addition, many mechanical system simulation programs using this analysis method are commercially available, and the environment is more versatile, easier to use, and can easily analyze vibration phenomena.

In the finite element method, with respect to the actual mechanism shown in FIG. 15, the shape is divided into each element 7 as shown in FIG. The displacement and stress are calculated every nine.
Examples of this type of conventional analysis apparatus include those described in Patent Document 1 and Non-Patent Document 1.
JP-A-9-280943 Hiroshima Prefectural Industrial Technology Center research report No. 13 (2000) "Research on dynamic evaluation and reliability technology of machines"

  In the method for analyzing the vibration of the conventional gantry mechanism described above, it is easy to model any mechanism shape by the modeling method using the finite element method. However, in order to deal with the various analysis objects, many calculation functions are added to the commercially available program, and since many emphasis is placed on ease of use, it has many GUI (Grgp11ical User Interface) functions. As a result, the program becomes large and the analysis target can be easily input, so that the model becomes complicated (of course, the number of data increases), resulting in a waste of resources and time for repeated calculation. It will be.

In order to prevent this waste of resources and time, the model is often simplified and analyzed by the finite element method as much as possible. However, as described above, when the mechanism becomes complex, how to simplify the actual mechanism often depends on experience and the intuition of the analyst, so anyone can easily use the finite element method. However, there is a problem that analysis cannot be performed.
The present invention has been made in view of such problems, and everyone has experienced vibration of a gantry mechanism comprising a top plate on which a driving machine that requires positioning and a flexible leg that supports the top plate are installed. To provide a platform mechanism vibration analysis device that can analyze with the same amount of calculation accuracy as the finite element method, which is a strict solution as much as possible, by inputting the minimum necessary parameters without relying on intuition It is an object.

  To achieve the above object, a gantry mechanism vibration analysis device according to claim 1 of the present invention is supported by a leg portion in which legs of at least one of a rod-like member and a plate-like member are combined in a gantry shape, and supported by the leg portion. In the gantry mechanism vibration analysis device for calculating the natural frequency of the gantry mechanism having a plate-like top plate on which the machine is installed, the width of the leg portion, the depth of the leg portion, The natural frequency is calculated by using the height of the leg, the material characteristics of the leg, the cross-sectional shape characteristics of the leg, the mass of the top plate, and the mass of the machine as input set values. .

  According to this configuration, the leg width, leg depth, leg height, leg material characteristics, leg cross-sectional characteristics, weight of the top plate, the top plate mass, The natural frequency of the gantry mechanism is calculated using the mass of the machine on the plate as an input parameter. This eliminates the need for modeling and calculation of a complicated portion that has conventionally required a lot of time, so that the calculation load of the natural frequency can be greatly reduced as compared with the conventional case.

In other words, in the method of modeling all of the gantry mechanism and analyzing it using the finite element method, modeling of complex parts, especially the shape of the top plate and machine parts are often complicated. It takes a lot of time to calculate. However, in the present invention, even if the top plate is regarded as a rigid body, the rigidity of the legs contributes a lot.Therefore, the error between the model and the actual machine is small. Modeling that ignores the effects of. By adopting such modeling, it is possible to calculate the natural frequency representing the vibration characteristics of the gantry mechanism by securing the analysis accuracy with the above input parameters alone and without particularly modeling the complicated machine part. .
In addition, the input values required for the gantry mechanism vibration analysis can be narrowed down to items that do not require experience as described above, regardless of the skill of the analyst using the gantry mechanism vibration analysis device, which is a simulation tool. In addition, anyone can easily analyze with a simple model.

The gantry mechanism vibration analysis apparatus according to claim 2 of the present invention is the gantry mechanism vibration analysis device according to claim 1, in which the leg is fixed on the ground surface in a horizontal direction parallel to the ground surface, a direction perpendicular to the horizontal direction, the leg. A value that is defined as having no degree of freedom is constrained in all the rotational directions in which the longitudinal axis rotates, and is added to the input set value.
According to this configuration, the natural frequency can be calculated more accurately when the legs of the gantry mechanism are completely fixed to the ground contact surface.

According to a third aspect of the present invention, the gantry mechanism vibration analyzing apparatus according to the first aspect is configured such that the fixed state of the leg on the ground contact surface is a horizontal direction parallel to the ground contact surface and a direction perpendicular to the horizontal direction. Has a degree of freedom, and a value determined to have a degree of freedom only in the rotational direction in which the longitudinal axis of the leg rotates is added to the input set value.
According to this configuration, the leg of the gantry mechanism is fixed to the grounding surface, but the natural frequency is calculated more accurately in the condition that the axis of the leg is in a rotating state rather than being completely fixed. can do.

According to claim 4 of the present invention, in any one of claims 1 to 3, the leg mechanism vibration analysis device has a plurality of legs and a bracing member that connects the legs. Further, the material characteristics, the cross-sectional shape characteristics, the length, and the installation position of the leg portion are added to the input set value.
According to this configuration, even when the plurality of legs of the gantry mechanism are connected and fixed by the brace members, the natural frequency can be calculated more accurately.

The gantry mechanism vibration analysis apparatus according to claim 5 of the present invention is characterized in that, in claim 1, the cross-sectional secondary moment of the leg is used as the cross-sectional shape characteristic of the leg, and the cross-sectional secondary moment is directly input. To do.
Even in this configuration, anyone can easily perform an analysis with a simple model regardless of the skill of an analyst who uses the gantry mechanism vibration analysis device as a simulation tool.

According to claim 6 of the present invention, the gantry mechanism vibration analyzing apparatus according to claim 1 uses the second moment of section of the leg as the sectional shape characteristic of the leg. The second moment of section is obtained from the above.
According to this configuration, since the cross-sectional secondary moment required for the gantry mechanism vibration analysis can be input by specifying the cross-sectional shape and cross-sectional shape dimensions of the leg of the corresponding gantry mechanism, Parameter input for gantry mechanism vibration analysis becomes easy.

Further, according to claim 7 of the present invention, the gantry mechanism vibration analysis device according to claim 1 uses cross-sectional moments of the legs as cross-sectional shape characteristics of the legs, and uses cross-sectional shapes of various legs and cross-sections 2 of the cross-sectional shapes. The second moment is stored in association with each other, and the second moment of the cross-section associated with the designated cross-sectional shape is selected.
According to this configuration, the secondary moment of the cross section required for the gantry mechanism vibration analysis can be input by designating the cross sectional shape of the leg of the corresponding gantry mechanism. Therefore, it is easier to input parameters.

The gantry mechanism vibration analysis apparatus according to claim 8 of the present invention is characterized in that, in claim 1, Young's modulus of the material of the leg is used as the gantry mechanism material characteristic, and the Young's modulus is directly inputted.
According to this configuration, since the Young's modulus necessary for the gantry mechanism vibration analysis is directly input, it is easy to input parameters for the gantry mechanism vibration analysis.

The gantry mechanism vibration analysis apparatus according to claim 9 of the present invention uses the Young's modulus of the material of the leg as the gantry mechanism material characteristic in claim 1, and uses the material name of each leg and the Young's modulus of the material. It stores in association with each other, and selects a Young's modulus associated with a designated material name.
According to this configuration, since the Young's modulus required for the gantry mechanism vibration analysis can be selected by inputting the material name of the leg of the gantry mechanism, it is easier to input parameters for the gantry mechanism vibration analysis. Become.

As described above, according to the gantry mechanism vibration analysis apparatus of the present invention, everyone has experienced vibration of the gantry mechanism comprising the top plate on which the driving machine that requires positioning and the flexible legs that support the top plate are installed. By inputting the minimum necessary parameters without relying on intuition, there is an effect that the analysis can be performed with a smaller amount of calculation and with the same analysis accuracy as the finite element method, which is an exact solution.
This has the effect of preventing waste of resources and time during analysis.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a gantry mechanism vibration analyzer according to an embodiment of the present invention.
The gantry mechanism vibration analysis apparatus 50 shown in FIG. 1 includes a parameter input unit 51, a natural frequency calculation unit 52, a parameter selection unit 53, a parameter DB (database) 54, and a display unit 55. This is a simulation tool configured with bus connections.
FIG. 2 conceptually shows the configuration of the gantry mechanism to be analyzed whose vibration is analyzed by the gantry mechanism vibration analyzing apparatus 50.

  The gantry mechanism 13 shown in FIG. 2 includes a leg portion 10 made of a rod-like or plate-like steel material, and a top plate 12 supported by the leg portion 10 and on which a machine 11 is installed. ing. However, the leg portion 10 includes two gantry legs 10a fixed perpendicularly to the floor surface and separated from each other by a predetermined distance, and a lower portion of the two legs 10a for fixing the gantry legs 10a. It consists of a brace 20a. In addition, the machine 11 is assumed to be an armed driver 14 that can hold and carry an object (not shown) in this example. Further, the arm-equipped drive body 14 is fixed on the top plate 12 via a moving means such as a stage 15 so as to be movable in the work space.

  As shown in FIG. 3, when the arm of the armed drive body 14 is moved in the direction of the arrow 16 by the stage 15, the gantry mechanism 13 is connected to the gantry leg 10a. A minute vibration 19 is generated with reference to a fixed point 18 with the floor surface, and the vibration remains even if the armed driver 14 stops. For this reason, it becomes inconvenient when the tact time is shortened and the arm of the drive body 14 with high accuracy is positioned. Therefore, vibration analysis of the gantry mechanism 13 is necessary.

The analysis of the natural frequency of the gantry mechanism 13, which is an important parameter representing the vibration characteristics of the gantry mechanism 13, will be described.
Normally, in the case of a model as shown in FIG. 15, the natural frequency f of the gantry mechanism 13 can be calculated by the following equation (1).
Natural frequency f = (1 / 2π) √ {(1 / M) × (12 nEI / L ³ )} (1)
here,
E: Young's modulus of the pedestal leg I: Second moment of section of the pedestal leg (a numerical expression of the degree of ease of deformation such as bending and deflection depending on the shape of the pedestal leg cross section)
n: Number of pedestal legs m: Total mass of the top plate and the machine on the top plate.

  By the way, the actual gantry mechanism 13 is not a simple mechanism like the gantry mechanism 13 shown in FIG. 2, but has a diagonal bracing 20b in the leg portion 10 like the gantry mechanism 13-1 shown in FIG. Since some of them have complicated shapes, the above formula (1) is often not applicable as it is. In this case, there is a method of paying attention to the constituent member having the lowest rigidity in the constituting leg 10 and substituting the parameter into the equation (1), but it is difficult to obtain an exact solution.

Further, although the natural frequency f changes in the fixed state in the fixed state, the simple calculation formula (1) cannot reflect the fixed condition, and the error is large.
Therefore, in order to obtain good analysis accuracy, there is a method of modeling all the mechanisms and analyzing them using the finite element method. As shown in FIG. 5, the shape of the model shown in FIG. Dividing into each element 21 to be configured, boundary condition 23 is set and eigenvalue analysis is performed. However, in the modeling as shown in FIG. 5, much time is required for modeling and calculating a complicated portion. In particular, the shapes of the top plate 12 and the machine 11 are often complicated.

  Therefore, in the present embodiment, as shown in FIG. 6, each leg 10 a of the gantry leg 10 is regarded as a spring 24 and connected to each other, and the total mass of the top plate 12 and the machine 11 is determined by The model is constructed so as to be given as an equivalent concentrated mass to a point in contact with the top plate 12 among the connection points of the springs 24, that is, a point 26 in contact with the spring 25 regarded as the top plate 12. A stiffness equation is derived for each of the springs 24 and 25 of this model, and the natural frequency f is calculated by combining them.

Here, even if the top plate 12 is regarded as a rigid body, since the rigidity of the leg 10a contributes much, there is little error with the actual machine, so that the rigidity of the top plate 12 portion is sufficiently increased compared to the leg 10a. Modeling ignores the influence of the plate 12 portion.
By setting it as such modeling, the width of the leg part 10, the depth of the leg part 10, the height of the leg part 10, the material of the leg 10a, the cross-sectional shape of the leg 10a, the top plate 12, and the top plate 12 If the mass of each of the machines 11 above and the installation state of the legs 10a on the ground contact surface are input as input parameters, analysis accuracy can be ensured without particularly modeling the complicated machine 11 portion. The natural frequency f representing the vibration characteristics of the gantry mechanism 13 can be calculated. Moreover, the convenience as an analysis tool can be improved.

  By the way, in the calculation of the natural frequency f, since the calculation result differs depending on the setting of the fixed condition of the calculation model, it is necessary to set a constraint condition consistent with the actual machine in the calculation model. However, it is impossible to accurately set the fixed conditions of the actual machine in the calculation model in which the calculation load described in this embodiment is reduced as much as possible. Also, setting the fixed conditions in detail can be confusing at the time of input because it is difficult for the user to understand. Therefore, in the present embodiment, the fixed conditions are limited to two conditions of completely fixed and free to rotate, and by selecting from these, input is simple and sufficient calculation accuracy is guaranteed.

First, an example of the complete fixing will be described with reference to FIGS. FIG. 7 shows an example in which the gantry leg 10a is embedded and fixed in the ground 28 which is, for example, a concrete ground. FIG. 8 shows an example in which a ground plate 29 attached horizontally to the lower end of the gantry leg 10a is fixed to an anchor nut 30 driven into the ground 28 with a bolt 31.
When the gantry leg 10a is embedded in the ground 28 as shown in FIG. 7, the bottom surface of the leg 10a is almost fixed and has a low degree of freedom, and the conditions for solving the calculation model are horizontal, vertical, and all directions of rotation. This is in good agreement with the case where the above is constrained (first fixed condition). The calculation model in this case is shown in FIG.

FIG. 9 shows the degree of freedom of the fixed point 32 that is a contact point between the gantry leg 10a and the ground 28. The arrow Y1 indicates the horizontal direction, the arrow Y2 indicates the vertical direction, the arrow Y3 indicates the rotation direction, and the arrows Y1 to Y1. The X mark superimposed on Y3 indicates that there is no degree of freedom in that direction (restraint). In this case, there are no degrees of freedom in all horizontal, vertical and rotational directions.
On the other hand, when the ground plate 29 attached below the gantry leg 10a is fixed to the anchor nut 30 driven into the ground 28 with bolts 31 as shown in FIG. 8, the ground plate 29 is shown in FIG. This fixing point 32 is considered to be in close contact with the ground 28.

However, as shown in FIG. 10, in the vicinity 33 of the axis in the longitudinal direction (vertical direction) of the leg 10a, there is no restriction as shown by the arrow 34, and there is a degree of freedom. In this case, the fixed condition can be calculated with higher accuracy when the case where the horizontal and vertical directions are constrained and the rotation is free (second fixed condition) is used as compared with the case where the omnidirectional direction is constrained. A calculation model in this case is shown in FIG. FIG. 11 is a view similar to FIG. 9, and in this case, there is no degree of freedom in the horizontal and vertical directions indicated by arrows Y1 and Y2, and only the rotational direction indicated by arrow Y3 is a free condition.
Thus, by using two fixed conditions depending on the fixed state of the leg 10a, input setting is easy and analysis can be performed with high calculation accuracy.

  Further, for the gantry mechanism 13-1 having a complicated shape having the brace 20a, 20b shown in FIG. 4, as shown in FIG. 12, the gantry mechanism 13-1 is made up of the brace 20a, 20b and the leg 10a. Modeling is performed using a plurality of springs 35 and 25 divided at the joint point 36, and calculation is performed in the same manner as in the case of the gantry mechanism 13. Therefore, when the mechanism 11 is an analysis target, in addition to the above input parameters, the material of the braces 20a and 20b, the cross-sectional shape, the length, and the installation position are designated as input parameters.

  Further, among the above input parameter items, as a specific input method of the cross-sectional shape characteristic (secondary moment of cross section), a method (method 1) in which the analyst inputs directly to the parameter input unit 51, as will be described later The method of inputting the cross-sectional shape and cross-sectional shape dimension of the leg 10a necessary for calculating the cross-sectional secondary moment I of the leg 10a with the parameter input unit 51 (method 2), and selecting the prescribed leg shape of the leg 10a from the parameter DB 54 Then, there is a method of inputting (method 3).

  However, when the method 2 is realized, as shown in FIG. 13, the gantry mechanism vibration analysis device 50 further includes a cross-sectional secondary moment calculation unit 56. Further, when the method 3 is realized, a prescribed leg shape is selected from the parameter DB 54, a secondary moment of section corresponding to the leg shape is extracted, and the calculation is performed by assigning it to the calculation parameter. The parameter DB 54 stores very frequently used materials such as general structural lightweight steel, general structural square steel, hot rolled steel, and general aluminum drawn steel described in JIS.

Method 2 will be described. The parameter DB 54 stores various cross-sectional shapes such as a circle, a rectangle, and a hexagon of the leg 10a.
First, the analyst operates the parameter input unit 51 to designate the cross-sectional shape of the corresponding leg 10 a while displaying various cross-sectional shapes stored in the parameter DB 54 on the display unit 55. Next, the analyst operates the parameter input unit 51 to input dimensions of the cross-sectional shape displayed on the display unit 55.

The cross-sectional secondary moment calculation unit 56 calculates the cross-sectional secondary moment I of the cross-sectional shape based on the specified cross-sectional shape and the input dimension of the cross-sectional shape, and the calculated cross-sectional secondary moment I Is output to the natural frequency calculator 52.
Method 3 will be described. The parameter DB 54 stores the cross-sectional shapes of various columnar structures and the cross-sectional secondary moments I of the cross-sectional shapes in association with each other.

By operating the parameter input unit 51 by the analyst, the cross-sectional shape of the corresponding leg 10 a is specified while displaying the prescribed leg shape stored in the parameter DB 54 on the display unit 55. The cross-sectional secondary moment I associated with the designated cross-sectional shape is selected from the parameter DB 54 by the parameter selection unit 53 and output to the natural frequency calculation unit 52.
As for the Young's modulus E, there are a method in which the analyst directly inputs the numerical value of the Young's modulus E into the parameter input unit 51 and a method in which the Young's modulus E of the leg 10a is selected from the parameter DB 54 and input.

The latter method will be described. The parameter DB 54 stores a name of a material such as iron, copper, or aluminum that is a constituent material of the leg 10a and a Young's modulus E of the material in association with each other.
When the analyst inputs the material name of the leg 10 a from the parameter input unit 51, the Young's modulus E associated with the material name is selected from the parameter DB 54 by the parameter selection unit 53 and output to the natural frequency calculation unit 52. .

Here, FIG. 14 shows the relationship between each analysis condition (calculation load) of the gantry mechanism and an analysis error with the actual machine under the condition, and the explanation will be given.
In the figure, points 37 and 38 show the case of the simple solution, and the calculation load is the smallest, but the analysis error is 40% or more. On the other hand, points 39 and 40 show the case of an exact solution, and the analysis error is as small as about 3%, but the calculation load increases. Points 41 and 42 are obtained when the calculation model of the present embodiment is used, and the exact solution and the analysis accuracy are substantially the same, that is, within 10% of the analysis error that can be practically used as a tool as indicated by the broken line 43. However, the input parameters are limited so that the calculation load can be reduced.

The circles 37, 39, and 41 are when the gantry leg 10 a shown in FIG. 7 is embedded in the ground 28. The Δ marks at the points 38, 40, 42 are when the ground plate 29 attached under the leg 10 a shown in FIG. 8 is fixed to the ground 28 with bolts 31.
In the simple solution, since there is no input of the fixed condition, it cannot cope with the change of the natural frequency f due to the fixed condition, and the error varies, and the error is 70% at the maximum. On the other hand, in the exact solution, good analysis accuracy is obtained for two fixed states. Also in this embodiment, since the fixing condition corresponding to the fixed state is input, the same good accuracy can be obtained.

Even if the input parameters are narrowed down as compared with the case of the exact solution as described above, the analysis error is about 10% as shown by points 41 and 42, and the calculation load (calculation time) and the analysis error satisfy the practical level. .
Therefore, according to the gantry mechanism vibration analysis apparatus 50 of the present embodiment, it is possible to satisfy an analysis error within 10% that can be practically used as a tool. In addition, the input values required for the gantry mechanism vibration analysis can be narrowed down and input to items that do not require experience, so regardless of the skill of the analyst who uses the gantry mechanism vibration analysis device 50, which is a simulation tool, However, it is possible to easily analyze with a simple model.

It is a block diagram which shows the structure of the gantry mechanism vibration-analysis apparatus which concerns on embodiment of this invention. It is a block diagram of the gantry mechanism in which a vibration is analyzed by the gantry mechanism vibration analyzer which concerns on the said embodiment. It is a figure which shows the mode of the inconvenient micro vibration which arises when the rigidity of the leg part of the said gantry mechanism is not enough. It is a figure which shows the model of the gantry mechanism of a complicated shape which has a diagonal bracing further in said leg part. It is explanatory drawing at the time of calculating the vibration of the vibration model of said mount mechanism by a finite element method. It is a model figure at the time of considering each gantry leg and top plate in the above-mentioned gantry mechanism as a spring, and connecting them. It is a figure which shows the example by which said mount leg is embedded and fixed to the ground which is a concrete-like ground. It is a figure which shows the example in which the grounding plate attached horizontally to the lower end of said pedestal leg is being fixed with the bolt to the anchor nut driven into the ground. It is a model figure which shows the freedom degree of the fixed point which is a contact point of said gantry leg and the ground. It is a figure which shows that said pedestal leg has a freedom degree without restraint in the vicinity of the axis | shaft of the longitudinal direction. It is a model figure which shows the freedom degree of the fixed point which is a contact point of a mount leg in the case shown in FIG. It is a figure at the time of modeling a gantry mechanism in case the above-mentioned leg part has further diagonal braces with a spring. It is a block diagram which shows the structure which added the cross-sectional secondary moment calculating part to the gantry mechanism vibration-analysis apparatus based on the said embodiment. It is a figure which shows the relationship between each analysis condition (calculation load) of the said mount mechanism, and the analysis error with the real machine on the condition. It is a figure which shows the vibration model when attaching a weight to the front-end | tip of the conventional cantilever. It is a figure which shows the vibration model comprised by the conventional rigid body mass element, a spring element, and a damping element. It is explanatory drawing at the time of calculating the vibration of the vibration model shown in FIG. 15 by the finite element method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Leg part 10a Leg 11 Machine 12 Top plate 13 Mounting mechanism 15 Stage 20a, 20b Bracing 21 Element 22 Node 23 Boundary condition 24 Spring corresponding to leg 25 Spring corresponding to top plate 26 Contact between spring and spring 28 Floor 29 Grounding plate 30 Anchor nut 31 Bolt 32 Fixing point 33 Near the longitudinal axis of the leg 50 Mounting mechanism vibration analysis device 51 Parameter input unit 52 Natural frequency calculation unit 53 Parameter selection unit 54 Parameter DB (database)
55 Display 56 Cross section secondary moment calculator

Claims (9)

A platform mechanism comprising: a leg portion in which legs of at least one of a rod-shaped member and a plate-like member are combined in a gantry-like shape; and a plate-shaped top plate supported by the leg portion and having a machine installed on the upper surface thereof. In the platform mechanism vibration analyzer that calculates the natural frequency,
Input the width of the leg, the depth of the leg, the height of the leg, the material characteristics of the leg, the cross-sectional shape characteristics of the leg, the mass of the top plate, and the mass of the machine The gantry mechanism vibration analysis device, wherein the natural frequency is calculated as a set value. The fixed state of the leg on the ground contact surface is restricted in the horizontal direction parallel to the ground contact surface, the direction perpendicular to the horizontal direction, and the rotational direction in which the longitudinal axis of the leg rotates. The gantry mechanism vibration analysis device according to claim 1, wherein a value determined to be absent is added to the input set value. There is no degree of freedom in the fixed state of the leg on the ground contact surface in the horizontal direction parallel to the ground contact surface and the direction perpendicular to the horizontal direction, and only in the rotational direction in which the longitudinal axis of the leg rotates. The gantry mechanism vibration analysis device according to claim 1, wherein a value determined to be added is added to the input set value. When the leg portion has a plurality of legs and has a bracing member that connects the legs, the material properties of the bracing member, the cross-sectional shape characteristics, the length, and the installation position in the leg portion, The gantry mechanism vibration analysis apparatus according to any one of claims 1 to 3, wherein the gantry mechanism vibration analysis apparatus is added to an input set value. The transport mechanism motion analysis apparatus according to claim 1, wherein a cross-sectional secondary moment of the leg is used as a cross-sectional shape characteristic of the leg, and a cross-sectional secondary moment is directly input. 2. The gantry mechanism vibration according to claim 1, wherein a cross-sectional secondary moment of the leg is obtained from the cross-sectional shape and dimensions of the input leg using the cross-sectional secondary moment of the leg as the cross-sectional shape characteristic of the leg. Analysis device. The leg cross-sectional moments of the legs are used as the cross-sectional shape characteristics of the legs, and the cross-sectional shapes of the various legs and the cross-sectional secondary moments of the cross-sectional shapes are stored in association with each other and are associated with the designated cross-sectional shapes. 2. The gantry mechanism vibration analysis apparatus according to claim 1, wherein a second moment of inertia is selected. The gantry mechanism vibration analysis apparatus according to claim 1, wherein the Young's modulus of the leg material is used as the gantry mechanism material characteristic, and the Young's modulus is directly input. Using the Young's modulus of the leg material as the gantry mechanism material characteristic, the material name of each leg and the Young's modulus of the material are stored in association with each other, and the Young's modulus associated with the designated material name is stored. The gantry mechanism vibration analysis device according to claim 1, wherein the gantry mechanism vibration analysis device is selected.

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