JP5203100B2 - Structure analysis apparatus and structure analysis method - Google Patents

Description

  The present invention relates to a structural analysis apparatus and a structural analysis method for virtually dividing an observation object into a plurality of elements and obtaining a displacement of a node defined on the elements by numerical calculation.

  In conventional structural analysis, a model of an object to be analyzed is first created and virtually divided into finite elements. Structural analysis is performed by applying expected external force and constraint conditions. The verification of the analysis result is performed based on the experience of the analyst or a comparison with the experimental result. If it is determined that the analysis result is inadequate, the finite element division, the expected external force, and the constraint conditions are reviewed, and the structural analysis is performed again. The amount of this review work becomes enormous, and this review work often depends on the experience of the analyst.

  By correcting the parameters of the coupling part of the structural part so that the analysis result of the approximate model matches the result of the mechanical experiment, an appropriate parameter of the coupling part can be provided (Patent Document 1). By measuring the strain between specific nodes of the structure with a strain gauge and performing the structural analysis using the measurement result as a constraint, the accuracy of the analysis result can be increased (Patent Document 2).

JP-A-10-68669 Japanese Patent Laid-Open No. 11-258073

  An object of the present invention is to provide a structural analysis apparatus and a structural analysis method capable of easily enhancing consistency with experimental results.

According to another aspect of the invention,
An observation device for observing the position of the observation target mark fixed to the observation object;
A processing device to which the observation result of the observation device is input,
The processor is
Virtually dividing the observation object into a plurality of elements and setting a plurality of nodes on the elements;
Selecting a node that coincides with the position of the observation target mark, or one node on an element including the position of the observation target mark, as a specific node;
Defining a forced displacement point corresponding to each of the specific nodes;
Defining an interaction depending on the displacement of the forced displacement point and the displacement of the specific node between the forced displacement point and the specific node;
Measuring the displacement of the observation mark based on the observation result obtained from the observation device;
Determining a displacement of the forced displacement point associated with the specific node corresponding to the observation target mark based on the measured displacement of the observation target mark;
There is provided a structural analysis apparatus that executes a step of performing a structural analysis of the observation object using the determined displacement of the forced displacement point as a constraint condition.

According to another aspect of the invention,
Fixing the observation target mark to the observation target;
Virtually dividing the observation object into a plurality of elements and setting a plurality of nodes on the elements;
Selecting a node that coincides with the position of the observation target mark, or one node on an element including the position of the observation target mark, as a specific node;
Defining a forced displacement point corresponding to each of the specific nodes;
Defining an interaction depending on the displacement of the forced displacement point and the displacement of the specific node between the forced displacement point and the specific node;
Measuring the displacement of the observation mark based on the observation result obtained from the observation device;
Determining a displacement of the forced displacement point associated with the specific node corresponding to the observation target mark based on the measured displacement of the observation target mark;
There is provided a structural analysis method including a step of performing a structural analysis of the observation object using the determined displacement of the forced displacement point as a constraint condition.

  According to another aspect of the present invention, there is provided a structure analysis method executed by the structure analysis apparatus.

By reflecting the observation result of the displacement of the observation target mark corresponding to the specific node in the structural analysis, the consistency between the experimental result and the analysis result can be easily increased.

  Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 4, the second embodiment will be described with reference to FIGS. 5 to 10-2, the third embodiment will be described with reference to FIG. The fourth embodiment to which the first to third embodiments are applied will be described with reference to FIG.

  FIG. 1 shows a schematic diagram of a structural analysis apparatus according to the first embodiment. The observation object 10 is arranged in a space in which the XYZ global coordinate system is defined. A plurality of observation object marks 11 are fixed on the surface of the observation object 10. The observation target mark 11 may be formed by drawing directly on the surface of the observation target object 10, or a member with a mark attached thereto may be attached to the observation target object 10.

  The observation object 10 is deformed when an external force is applied. When the observation object 10 is deformed, the observation object mark 11 is displaced.

  The first observation device 31 observes a plurality of observation target marks 11, and the second observation device 32 observes a plurality of other observation target marks 11. For example, a digital camera is used for the first observation device 31 and the second observation device 32. A part of the observation target marks 11 may be observed by both the first observation device 31 and the second observation device 32.

  Each of the first observation device 31 and the second observation device 32 includes a lens and an image receiving surface. A first local coordinate system fixed to the first observation device 31 is defined, and a second local coordinate system fixed to the second observation device 32 is defined. The first local coordinate system is defined by a W axis that is coincident with the optical axis of the lens of the first observation device 31, a U axis that is perpendicular to the W axis, and orthogonal to each other, and the origin is the lens. Matches the principal point of The image receiving surface is parallel to the UV surface. The second local coordinate system is defined by a T-axis that coincides with the optical axis of the lens of the second observation device 32, an R-axis and an S-axis that are perpendicular to the T-axis and orthogonal to each other, and the origin is the lens. Matches the principal point of The image receiving surface is parallel to the RS surface.

  Image data captured by the first observation device 31 and the second observation device 32 is input to the processing device 40. The processing device 40 processes the input image data and obtains a time calendar of the shape change of the observation object 10. The time calendar of the shape change is displayed on the image display device 41 as an image.

  FIG. 2 shows a flowchart of the structure analysis method according to the first embodiment. First, in step SA1, the observation object mark 11 is fixed to the observation object 10. In step SA2, the shape (analysis model) of the observation object 10 is defined using CAD. The shape of the observation object 10 is defined in the CAD coordinate system. In step SA3, a global coordinate system associated with the CAD coordinate system is defined. Usually, the CAD coordinate system may be adopted as the global coordinate system.

  In step SA4, the observation object (analysis model) defined by CAD is virtually divided into a plurality of finite elements. Further, the rigidity is defined for each finite element based on the rigidity of the material constituting the measurement object. A node coincident with the position of the observation target mark 11 or one node on the finite element including the position of the observation target mark 11 is selected as a “special node”. The nodes other than the specific node are referred to as “general nodes”. FIG. 1 shows an example in which the observation object 10 is divided into a number of cubic elements. Nodes 13 are defined at the vertices of each element. Each element may have an arbitrary three-dimensional shape having a polygonal surface. In this case, the vertex of the polygonal surface is the node 13. The processing device 40 stores the position of each node 13B in the global coordinate system.

  In step SA5, the first observation device 31 and the second observation device 32 are arranged and fixed in the space in which the global coordinate system is defined. The processing device 40 stores the positions and orientations of the first observation device 31 and the second observation device 32 in the global coordinate system. The position of the first observation device 31 is specified by the global coordinates of the principal point of the lens. The posture of the first observation device 31 is specified by the optical axis of the lens, that is, the direction of the W axis and the direction of the U axis. Similarly, the position of the second observation device 32 is specified by the global coordinates of the principal point of the lens, and the posture is specified by the directions of the T axis and the R axis.

  In the first embodiment, the W axis of the first local coordinate system fixed to the first observation device 31 is parallel to the Z axis of the global coordinate system, and the second axis fixed to the second observation device 32 is used. The first and second observation devices 20 and 30 are arranged so that the T axis of the local coordinate system is parallel to the X axis of the global coordinate system. In the case of this arrangement, the first observation device 31 observes displacement in the direction orthogonal to the W axis, that is, the XY in-plane direction, and the second observation device 32 is in the direction orthogonal to the T axis, that is, in the YZ plane. Directional displacement can be observed.

  It is preferable to arrange the first and second observation devices 31 and 32 according to the expected deformation of the observation object 10. For example, if the direction of the external force is parallel to the XY plane and the magnitude thereof is substantially constant with respect to the Z direction, the deformation of the observation object 10 is predicted to occur in a direction substantially parallel to the XY plane. This deformation can be observed mainly by the first observation device 31.

  In the following description, a case will be described in which the observation object 10 is predicted to deform mainly in a direction parallel to the XY plane.

  In step SA6, the observation object mark 11 is imaged by the first observation apparatus 31 and the second observation apparatus 32 while applying an external force to the observation object 10. The captured image data is input to the processing device 40. The processing device 40 measures the position of the image of the observation target mark 11 in the image receiving plane by performing image analysis. In the following steps, processing of image data acquired by the first observation apparatus 31 will be described. Processing of the image data acquired by the second observation device 32 is performed in the same manner.

The image receiving surface of the first observation apparatus 31 is parallel to the UV plane of the first local coordinate system. For this reason, the position in the image receiving surface is specified by the U coordinate and the V coordinate. By analyzing the image data at the observation times t ₀ , t ₁ , t ₂ ..., The positions of the observation target marks 11 at the observation times, that is, (U, V) coordinates are detected. Hereinafter, an example of a method for detecting the position of the observation target mark 11 will be described.

  First, a rectangular region including the observation target mark 11 is cut out from the image data. The (U, V) coordinates of the clipped area, for example, the (U, V) coordinates of one vertex of the rectangle are stored. The cut image data is subjected to processing such as a low-pass filter or contraction / expansion operation for the purpose of noise removal. Using the image data from which the noise has been removed, the position of the observation target mark 11 within the clipped region is detected.

  For the detection of the mark position, it is preferable to use the center of gravity calculation or the peak value detection method. Since the mark image may be blurred, position detection by the edge detection method or pattern matching method is not suitable. By setting a threshold value for the light intensity and performing the centroid calculation only for pixels that are equal to or greater than the threshold value, it is possible to make it less susceptible to the influence of the light intensity of the background.

  The (U, V) coordinates of the observation target mark 11 in the image receiving plane can be calculated from the position of the cut out region and the position of the observation target mark 11 in the cut out region. The (U, V) coordinates of the other observation target marks 11 are obtained by the same method.

  In step SA7, the displacement amount (ΔU, ΔV) in the image receiving plane from one observation time to the next observation time is calculated from the (U, V) coordinates for each observation time of the observation target mark 11. Since the relative positional relationship between the global coordinate system and the first local coordinate system and the (X, Y) coordinates of the observation target mark 11 are known, the displacement amount (ΔX, ΔY) of the observation target mark 11 in the global coordinate system is known. Can be requested. The displacement amount (ΔX, ΔY) of the observation target mark 11 is set as the displacement amount of the specific node corresponding to the observation target mark 11.

  FIG. 3 shows an example of the displacement amount (ΔX, ΔY) of the observation target mark 11. A displacement vector 15 parallel to the XY plane is associated with each observation target mark 11 observed by the first observation device 31. Similarly, the displacement amount (ΔY, ΔZ) of the observation target mark 11 observed by the second observation device 32 is calculated, and a displacement vector 16 parallel to the YZ plane is associated with each observation target mark 11.

  In step SA8, the structural static analysis is performed at each observation time with the displacement amount of the specific node associated with the observation target mark 11 as a constraint condition and other external forces and constraint conditions. At this time, the displacement amount ΔZ in the Z direction of the specific node to be observed by the first observation device 31 and the displacement amount ΔX in the X direction of the specific node to be sighed by the second observation device 32 are restricted. do not do. For structural static analysis, a general finite element method or the like can be used. Thereby, the displacement amount of the general node is calculated.

  In step SA9, the state of change in the shape of the observation object 10 is displayed on the image display device 41 as a moving image based on the displacement amounts of the specific node and the general node.

  FIG. 4 shows a schematic diagram of the image display device 41. An object display area 42 is secured in the display screen, and an operation unit 43, an elapsed time display bar 44, and a display command unit 45 are displayed on the outside thereof. In the object display area 42, the object is displayed three-dimensionally. Through the operation unit 43, operations such as display start, display stop, and display pause are performed. In the elapsed time display bar 44, the elapsed time up to the currently displayed time is displayed in a bar shape. In addition, the elapsed time from the start of observation can be specified via the elapsed time display bar, and the change in shape from the specified time can be displayed.

  An instruction to enlarge, reduce, rotate, etc. the image displayed in the object display area 42 is given through the display command unit 45. For this reason, the deformation of the observation object 10 can be confirmed from various viewpoints. The displacement amount of each node can be enlarged and displayed. When the change in the shape of the observation object is slight, it is easy to visually recognize the change in the shape by displaying the displacement amount in an enlarged manner.

  By continuously displaying the shape of the observation target object over time, the change in the shape of the observation target object 10 can be easily grasped visually. In order to make it easy to grasp the deformation amount of each part, an equal displacement amount line may be displayed, or a contour display in which the display color is changed according to the displacement amount may be performed.

  In the first embodiment, the displacement amount of some specific nodes among the nodes is set as a constraint condition based on the actual observation result, so that the accuracy of the structural analysis can be improved.

  FIG. 5 shows a schematic diagram of a structural analysis apparatus according to the second embodiment. The configurations of the observation object 10, the first observation device 31, the second observation device 32, and the image display device 41 are the same as those of the first embodiment, and the processing performed by the processing device 40 is the same as that of the first embodiment. It is different from processing.

  FIG. 6 shows a flowchart of the structure analysis method according to the second embodiment. Steps SB1 to SB5 are the same as steps SA1 to SA5 of the first embodiment.

  In step SB6, at least one forced displacement point is defined corresponding to each specific node.

  FIG. 7 shows an example of the forced displacement point. Two forced displacement points 17 and 18 are defined for the specific node 13s corresponding to the observation target mark observed by the first observation device 31. Since the displacement direction observable by the first observation device 31 is parallel to the UV plane, the forced displacement points 17 and 18 are defined at positions where the specific nodes 13s are moved in a direction parallel to the UV plane. . In FIG. 7, one forced displacement point 17 is defined at a position where the specific node 13s is moved in a direction parallel to the U axis, and another forced displacement point 18 is defined at a position moved in a direction parallel to the V axis. doing.

  The specific node 13 s and the forced displacement point 17 are connected by a virtual spring 19, and the specific node 13 s and the other forced displacement point 18 are connected by a virtual spring 20. The specific node 13 s and the forced displacement point 17, and the specific node 13 s and the forced displacement point 18 interact with each other through a spring 19 and a spring 20, respectively. In the initial state, the springs 19 and 20 are in a neutral state. That is, the specific node 13 s does not receive a force from the forced displacement points 17 and 18 via the springs 19 and 20.

  When the distance between the specific node 13s and the forced displacement point 17 deviates from the neutral position, a force due to the restoring force of the spring 19 acts on the specific node 13s. Similarly, when the interval between the specific node 13s and the other forced displacement point 18 is deviated from the neutral position, a force due to the restoring force of the spring 20 acts on the specific node 13s. The distance between the specific node 13s and the forced displacement point 17 is such that the direction of the restoring force of the spring 19 in the U-axis direction does not reverse before and after the displacement even if the maximum expected displacement occurs at the specific node 13s. Set. The interval between the specific node 13s and the forced displacement point 18 is set so that the direction of the restoring force of the spring 20 in the V-axis direction is not reversed before and after the displacement even if the assumed maximum displacement occurs at the specific node 13s. Set. A suitable spring constant setting method will be described later.

  Steps SB7 and SB8 are the same as steps SA6 and SA7 of the first embodiment.

  In step SB9, the displacement amount of the forced displacement point corresponding to the specific node is calculated based on the displacement amount of the specific node.

As shown in FIG. 8A, the specific node 13s is displaced from the observation time t = t _i to t = t _{i + 1 by} the displacement destination 13Sa. The displacement from the specific node 13S to the displacement destination 13Sa is represented by a displacement vector 50. As shown in FIG. 8B, displacements represented by the same displacement vectors 25 and 26 as the displacement vector 50 are forcibly set at the forced displacement points 17 and 18 corresponding to the specific node 13s, until the displacement destinations 17a and 18a. Displace. At this time, since the springs 19 and 20 expand and contract, a force acts on the specific node 13s by the restoring force.

  In step SB10, the structural analysis of the observation object 10 is performed using the displacement amount forcibly set at the forced displacement point as a constraint condition, and the displacement of the specific node and the general node is calculated.

  As shown in FIG. 8C, for example, the specific node 13s is displaced to the displacement destination 13Sb by the restoring force of the springs 19 and 20 and the force received from other nodes by the forced displacement given to the forced displacement points 17 and 18. To do. The displacement destination 13Sb does not necessarily coincide with the observed displacement destination 13Sa of the specific node 13s shown in FIG. 8A.

  Step SB11 is the same as step SA9 of the first embodiment.

  With reference to FIG. 9, the effect of Example 2 is demonstrated. In order to simplify the description, a one-dimensional model will be described.

  As shown in FIG. 9A, a plurality of nodes are defined on a straight line. A general node 70 is arranged between the specific nodes 60A to 60F. In Example 1, as shown in FIG. 9B, forced displacements 61A to 61F are set at the specific nodes 60A to 60F, respectively. For this reason, variation in the measurement of the position of the observation target mark 11 directly affects the displacement of the specific node. If a relatively large measurement error occurs in the measurement of the position of one observation target mark 11 as compared to the nearby observation target mark 11, a structural analysis may cause a deformation that cannot occur in reality. is there.

  For example, in FIG. 9B, when the specific node 60B includes a relatively large measurement error as compared with other specific nodes, a normal node between the specific node 60B and the specific nodes 60A and 60C on both sides thereof is usually set. In such a case, a large distortion that does not occur may occur.

  FIG. 9C shows an example in which the forced displacement points 65A to 65F according to the second embodiment are introduced. The specific node 60A and the forced displacement point 65A are connected by a spring 66A. Similarly, the other specific nodes 60B to 60F and the forced displacement points 65B to 65F are also connected by springs 66B to 66F, respectively.

  As shown in FIG. 9D, forced displacements 61A to 61F are set at the forced displacement points 65A to 65F, respectively. Thereby, the force by the restoring force of spring 66A-66F acts on specific node 60A-60F. Structural analysis is performed using the displacements of the forced displacement points 65A to 65F as constraint conditions.

  As shown in FIG. 9E, the specific nodes 60A to 60F are displaced. The displacement amounts of the forced displacement points 65A to 65F act on the specific nodes 60A to 60F via the springs 66A to 66F. The positions of the specific nodes 60A to 60F are analyzed so that this action is balanced. For this reason, the error included in the measurement result of the position of the observation target mark 11 is smoothed. For example, even if a relatively large measurement error is included in the position of the observation target mark 11 corresponding to one specific node 60B, the measurement result of the position of the observation target mark 11 corresponding to the nearby specific nodes 60A, 60C, etc. If the included error is small, the influence of the measurement error at the position of one observation target mark 11 on the analysis result is small.

  When the measurement by the first and second observation devices 31 and 32 is highly accurate and almost no measurement error occurs, the spring constants of the virtual springs 66A to 66F may be increased. As a result, the degree of influence of the measured displacement amount of the observation mark 11 on the displacement amount of the specific node increases. As an example, when the structure analysis is performed with the spring constant set to infinity, the same result as that obtained when the structure analysis is performed by the method according to the first embodiment can be obtained.

  On the contrary, when an error is likely to occur in the measurement by the first and second observation devices 31 and 32, the spring constants of the virtual springs 66A to 66F are smaller than the rigidity of the material constituting the measurement object. do it. Thereby, the displacement amount of the specific node is more influenced by the structure of the measurement object than by the forced displacement point. As a result, measurement variations can be leveled.

  In the second embodiment, the case where one observation target mark 11 is observed by one observation apparatus has been described. Next, processing when one observation target mark 11 is observed by both the first and second observation apparatuses 31 and 32 will be described.

  As shown in FIG. 10A, the observation target mark corresponding to the specific node 70 is observed by both the first observation device 31 and the second observation device 32. The posture of the first observation device 31 and the posture of the second observation device 32 are arbitrary. However, the W axis of the first observation device 31 and the T axis of the second observation device 32 are not parallel.

  A forced displacement point 71 is defined at a position where the specific node 70 is moved in a direction parallel to the U axis, and a forced displacement point 72 is defined at a position where the specific node 70 is moved in a direction parallel to the R axis. Actually, the forced displacement point is also defined at a position where the specific node 70 is moved in the direction parallel to the V-axis and the direction parallel to the S-axis, but here, for simplicity of explanation, Assume that only two forced displacement points 71, 72 are defined.

  The specific node 70 and the forced displacement point 71 are connected by a virtual spring 73, and the specific node 70 and the forced displacement point 72 are connected by a virtual spring 74. The displacement destination 70 a of the specific node 70 is calculated based on the observation result by the first observation device 31, and the displacement destination 70 b of the specific node 70 is calculated based on the observation result by the second observation device 32. The displacement vector from the specific node 70 to the displacement destination 70a is parallel to the UV plane, and the displacement vector from the specific node 70 to the displacement destination 70b is parallel to the RS plane. One forced displacement point 71 bears a displacement in a direction parallel to the UV plane, and the other forced displacement point 72 bears a displacement in a direction parallel to the RS plane.

  As shown in FIG. 10B, one forced displacement point 71 is forcibly displaced to a displacement destination 71a, and the other forced displacement point 72 is forcibly displaced to a displacement destination 72a. The displacement vector from the forced displacement point 71 to the displacement destination 71a is equal to the displacement vector from the specific node 70 to the displacement destination 70a. The displacement vector from the forced displacement point 72 to the displacement destination 72a is equal to the displacement vector from the specific node 70 to the displacement destination 70b. Structural analysis is performed under this constraint condition. A force is applied to the specific node 70 by the restoring force of the virtual springs 73 and 74.

  As shown in FIG. 10C, the specific node 70 is displaced to the displacement destination 70c under the influence of the restoring force of the springs 73 and 74 and other nodes.

  As described above, the forced displacement point 71 for reflecting the observation result by the first observation device 31 and the forcing to reflect the observation result by the second observation device 32 corresponding to one specific node 70. A displacement point 72 is defined. Thereby, the observation results of both the first observation device 31 and the second observation device 32 can be reflected in the displacement of the specific node 70.

  In the second embodiment, the specific node and the forced displacement point are connected by a virtual spring. However, another model that exerts a mechanical interaction between the specific node and the forced displacement point may be adopted. For example, a potential field that minimizes the potential at the neutral position may be defined in the space around the forced displacement point.

  FIG. 11A shows a model of the structural analysis method of the third embodiment. A model representing the observation object 10 is divided into a plurality of finite elements 80. An angle sensor 81 is attached to a position corresponding to some finite element of the observation object 10. For example, a biaxial acceleration sensor can be used as the angle sensor. By measuring the gravitational acceleration with a biaxial acceleration sensor, the tilt angle of the sensor itself from the horizontal direction can be calculated.

  FIG. 11B shows the inclination angle from the horizontal direction obtained by the angle sensor 81. The tilt angle obtained by the angle sensor is reflected in the attitude of the finite element corresponding to the angle sensor 81. Static structural analysis is performed using the reflected posture as a constraint.

  As shown in FIG. 11D, a change in the shape of the model representing the observation target is calculated.

  Also in Example 3, since the experimental result is reflected as a constraint condition of the structural static analysis, the consistency between the experimental result and the analytical result can be easily increased.

  FIG. 12 shows a front view of an injection molding machine on which the structural analysis apparatus according to the above embodiment can be mounted. The injection molding machine 340 includes an injection device 350 and a mold clamping device 370.

  The injection device 350 includes a heating cylinder 351, and a hopper 352 that supplies resin is disposed in the heating cylinder 351. Further, a screw 353 is disposed in the heating cylinder 351 so as to be able to advance and retreat and to be rotatable. The rear end of the screw 353 is rotatably supported by the support member 354. A measuring motor 355 such as a servo motor is attached to the support member 354 as a drive unit. The rotation of the weighing motor 355 is transmitted to the screw 353 of the driven portion via a timing belt 356 attached to the output shaft 361 of the weighing motor 355. A detector 362 is directly connected to the rear end of the output shaft 361 of the weighing motor 355. The detector 362 detects the rotation speed or rotation amount of the metering motor 355. Based on the number of rotations or amount of rotation detected by the detector 362, the rotational speed of the screw 353 is obtained.

  The injection device 350 further includes a screw shaft 357 parallel to the screw 353 so as to be rotatable. The rear end of the screw shaft 357 is connected to the injection motor 359 via a timing belt 358 attached to the output shaft 363 of the injection motor 359 such as a servo motor. Therefore, the screw shaft 357 can be rotated by the injection motor 359. The front end of the screw shaft 357 is screwed with a nut 360 fixed to the support member 354. When the injection motor 359 that is a drive unit is driven and the screw shaft 357 that is a drive transmission unit is rotated via the timing belt 358, the support member 354 moves forward and backward.

  A load cell 365 as a load detector is attached to the support member 354. The forward / backward movement of the support member 354 is transmitted to the screw 353 via the load cell 365, whereby the screw 353 moves forward / backward. Data corresponding to the force detected by the load cell 365 is sent to the processing device 310. A detector 364 is directly connected to the rear end of the output shaft 363 of the injection motor 359. The detector 364 detects the rotation speed or rotation amount of the injection motor 359. Based on the number of rotations and the amount of rotation detected by the detector 364, the moving speed of the screw 353 in the forward / backward direction or the position in the forward / backward direction is obtained.

  The mold clamping device 370 includes a movable platen 372 to which a movable mold 371 is attached, and a fixed platen 374 to which a fixed mold 373 is attached. The movable platen 372 and the fixed platen 374 are connected by a tie bar 375. The movable platen 372 is slidable along the tie bar 375. The mold clamping device 370 includes a toggle mechanism 377. The toggle mechanism 377 has one end connected to the movable platen 372 and the other end connected to the toggle support 376. A ball screw shaft 379 is rotatably supported at the center of the toggle support 376. A nut 381 fixed to a cross head 380 provided in the toggle mechanism 377 is screwed onto the ball screw shaft 379. A pulley 382 is disposed at the rear end of the ball screw shaft 379, and a timing belt 384 is bridged between the output shaft 383 of the mold clamping motor 378 such as a servo motor and the pulley 382.

  In the mold clamping device 370, when the mold clamping motor 378 that is a drive unit is driven, the rotation of the mold clamping motor 378 is transmitted to the ball screw shaft 379 that is the drive transmission unit via the timing belt 384. Then, the ball screw shaft 379 and the nut 381 change the direction of motion from rotational motion to linear motion, and the toggle mechanism 377 is operated. By the operation of the toggle mechanism 377, the movable platen 372 slides along the tie bar 375, and mold closing, mold clamping, and mold opening are performed.

  A detector 385 is directly connected to the rear end of the output shaft 383 of the mold clamping motor 378. The detector 385 detects the rotation speed or rotation amount of the mold clamping motor 378. Based on the number of rotations or the amount of rotation detected by the detector 385, the position of the crosshead 380 that moves forward and backward with the rotation of the ball screw shaft 379, or the driven part connected to the crosshead 380 by the toggle mechanism 377 The position of a certain movable platen 372 is determined. The processing device 310 controls the weighing motor 355, the injection motor 359, and the mold clamping motor 378.

  A cavity cav is formed between the movable mold 371 and the fixed mold 373. The cavity cav and the inside of the heating cylinder 351 communicate with each other.

  When the mold clamping is performed, stress is applied to the movable mold 371 and the fixed mold 373, and these molds are slightly deformed. In order to increase the precision of the shape of the injection molded product, it is desired to observe a slight deformation of the mold.

  A plurality of observation target marks are fixed to the side surfaces of the movable mold 371 and the fixed mold 373. By observing these observation target marks using the structural analysis apparatus according to the above embodiment, the state of deformation of the mold can be confirmed by an image.

  In the above embodiment, the digital camera is used for the observation devices 20 and 30 for detecting the displacement amount of the observation target mark 11, but the displacement amount may be detected by other methods. For example, it is also possible to detect the displacement amount of the observation target mark using a laser displacement meter.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

1 is a schematic diagram of a structural analysis apparatus according to Embodiment 1. FIG. 3 is a flowchart of a structural analysis method according to the first embodiment. FIG. 5 is a diagram showing an example of displacement given to a specific node by the structure analysis method according to the first embodiment. 1 is a schematic diagram of an image display device for a structural analysis layer according to Example 1. FIG. It is the schematic of the structure analysis apparatus by Example 2. FIG. 6 is a flowchart of a structure analysis method according to a second embodiment. It is a diagram which shows the relationship between a specific node and a forced displacement point. (8A) is a diagram showing the displacement obtained from the observation result of the observation target mark corresponding to the specific node, and (8B) is a diagram showing the forced displacement set at the forced displacement point. (8C) is a diagram showing the displacement of a specific node by structural analysis. (9A) is a diagram showing the structural analysis model, (9B) is a diagram showing an example of the result of the structural analysis performed by the method of Example 1, and (9C) shows the structural analysis model. FIG. 9D is a diagram in a state where a forced displacement point is defined, FIG. 9D is a diagram of a structural analysis model after setting the forced displacement at the forced displacement point, and FIG. 9E is a structural analysis model after the structural analysis. FIG. (10A) is a diagram showing specific nodes and forced displacement points corresponding to observation target marks observed by two observation devices, and (10B) is a diagram in a state where forced displacement is set at the forced displacement points. It is. (10C) is a diagram showing the position of a specific node after structural analysis. 6 is a diagram showing a structural analysis model of Example 3. FIG. It is a front view of the injection molding machine to which the structural analysis apparatus by an Example is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Observation object 11 Observation target mark 13 Node 13S Specific node 15, 16 Displacement 17, 18 Forced displacement point 19, 20 Virtual spring 25, 26 Displacement vector 31 1st observation apparatus 32 2nd observation apparatus 40 Processing apparatus 41 Image Display Device 42 Object Display Area 43 Operation Unit 44 Elapsed Time Display Bar 45 Display Command Unit 50 Displacement Vectors 60A-60F Specific Nodes 61A-61F Displacement Vectors 65A-65F Forced Displacement Points 66A-66F Virtual Spring 70 Specific Nodes 71, 72 Forced displacement points 73, 74 Virtual spring 80 Finite element 81 Angle sensor

Claims (6)

An observation device for observing the position of the observation target mark fixed to the observation object;
  A processing device to which an observation result of the observation device is input;
Have
  The processor is
  Virtually dividing the observation object into a plurality of elements and setting a plurality of nodes on the elements;
  Selecting a node that coincides with the position of the observation target mark, or one node on an element including the position of the observation target mark, as a specific node;
  Defining a forced displacement point corresponding to each of the specific nodes;
  Defining an interaction depending on the displacement of the forced displacement point and the displacement of the specific node between the forced displacement point and the specific node;
  Measuring the displacement of the observation mark based on the observation result obtained from the observation device;
  Determining a displacement of the forced displacement point associated with the specific node corresponding to the observation target mark based on the measured displacement of the observation target mark;
  And a step of performing a structural analysis of the observation object using the determined displacement of the forced displacement point as a constraint. The structural analysis apparatus according to claim 1, wherein the interaction that the forced displacement point exerts on the specific node is a restoring force that returns an interval between the forced displacement point and the specific node to an initial state. Fixing the observation target mark to the observation target;
  Virtually dividing the observation object into a plurality of elements and setting a plurality of nodes on the elements;
  Selecting a node that coincides with the position of the observation target mark, or one node on an element including the position of the observation target mark, as a specific node;
  Defining a forced displacement point corresponding to each of the specific nodes;
  Defining an interaction depending on the displacement of the forced displacement point and the displacement of the specific node between the forced displacement point and the specific node;
  Measuring the displacement of the observation mark based on the observation result obtained from the observation device;
  Determining a displacement of the forced displacement point associated with the specific node corresponding to the observation target mark based on the measured displacement of the observation target mark;
  A structural analysis method including a step of performing structural analysis of the observation object using the determined displacement of the forced displacement point as a constraint condition. The structural analysis method according to claim 3, wherein the interaction that the forced displacement point exerts on the specific node is a restoring force that returns an interval between the forced displacement point and the specific node to an initial state. An angle measuring device that is discretely fixed to the surface of the observation object and measures the tilt angle from the reference plane;
  A processing device to which the measurement result of the angle measuring device is input; and
Have
  The processor is
  Virtually dividing the observation object into a plurality of elements;
  Measuring an inclination angle from a reference plane of the surface of the observation object at a position where the angle measuring device is attached with the angle measuring device;
  A step of forcibly setting a posture change based on a measured inclination angle in an element corresponding to a position where the angle measuring device is attached among the plurality of elements;
  And a step of performing a structural analysis of the observation object using the determined forced posture change as a constraint condition. A step of discretely fixing a plurality of angle measuring devices for measuring an inclination angle from the reference plane on the surface of the observation object;
  Virtually dividing the observation object into a plurality of elements;
  Causing a change in shape of the observation object, and measuring an inclination angle from a reference plane of the surface of the observation object at a position where the angle measurement apparatus is attached, with the angle measurement device;
  A step of forcibly setting a posture change based on a measured inclination angle in an element corresponding to a position where the angle measuring device is attached among the plurality of elements;
  Performing the structural analysis of the observation object with the forced posture change determined as a constraint condition;
Structural analysis method having

Images