JP4853145B2 - Molding process simulation apparatus, molding process simulation program, and deformation analysis method for molded product - Google Patents

Description

  The present invention relates to a molding process simulation apparatus, a molding process simulation program, and a deformation analysis method of a molded product. More specifically, the present invention relates to a molding process simulation device, a molding process simulation program, and a molding for evaluating an injection molding process of an insert molded product. The present invention relates to a deformation analysis method for products.

  Conventionally, an injection molding process for manufacturing a resin part having a desired shape by filling a liquefied resin in a cavity of a metal mold, cooling it, and transferring the shape of the mold has been widely used. . In the injection molding process, it is desirable to reduce the number of trials required for optimizing the mold shape and the number of experiments for finding the optimal molding conditions in order to shorten the period required for actual product production. Therefore, CAE analysis based on the finite element method or the like is used to evaluate the molding process by simulation (see Patent Document 1).

  In such CAE analysis, first, the shape of a molded product or a mold is acquired from CAD or the like, mesh division is performed, and a node as a point of interest at the time of analysis is set. Then, flow analysis and structural analysis are performed to evaluate deformation when the resin filled in the cavity cools and solidifies. Here, in order to accurately perform the structural analysis, a constraint condition that restricts movement is set for each node that is set at a location where the deformation direction is restricted, such as each node on the boundary with the mold. Is called. In particular, in insert molding, in which metal parts are installed in the mold cavity in advance and the resin is filled into the mold, molding is performed on the interface between the mold and the insert in order to correctly evaluate the deformation of the insert. It is important to give appropriate constraints to existing nodes.

Conventionally, the setting of constraint conditions has been performed manually. However, even with only the nodes existing on the surface of the mold, there are a very large number of 1000 or more in some cases. Therefore, the setting of the constraint condition is a very time-consuming and complicated operation. Moreover, if the constraint conditions are set incorrectly, the analysis cannot be performed correctly, and the optimum mold shape and molding conditions cannot be obtained.
Furthermore, during the molding process, the resin or insert that has been in contact with the mold may be separated from the mold. In order to accurately simulate such a situation, it is necessary to update the constraint conditions during the analysis. However, it is practically impossible to manually update the constraint conditions because of the enormous amount of work.

JP 2003-11199 A

  In view of the above problems, an object of the present invention is to provide a molding process simulation apparatus, a molding process simulation program, and a deformation analysis method for a molded product, which can execute CAE analysis with a small number of work steps.

  Another object of the present invention is to provide a molding process simulation apparatus, a molding process simulation program, and a deformation analysis method for a molded product that can accurately evaluate the deformation of the insert in insert molding.

  According to the first aspect of the present invention, the molding process simulation apparatus (1) according to the present invention generates an analysis model of a molded product including an insert that is fixed to a mold and disposed in a cavity. An analysis model generation unit (10) for setting a plurality of nodes in the analysis model, a constraint condition setting unit (20) for setting predetermined constraint conditions on the boundary nodes existing on the boundary surface between the mold and the insert, and analysis A flow analysis unit (30) that performs flow analysis based on the model and calculates pressure distribution and temperature distribution in the cavity, and inserts based on the pressure distribution and temperature distribution, and the constraint conditions set at the nodes on the boundary. And an insert deformation amount calculation unit (52) for determining the amount of deformation.

According to the third aspect of the present invention, the deformation analysis method for a molded product according to the present invention generates an analytical model of a molded product including an insert that is fixed to a mold and placed in a cavity. An analysis model generation step (S101, S102) for setting a plurality of nodes in the analysis model, and a constraint condition setting step (S104, S102) for setting predetermined constraint conditions on the boundary nodes existing on the boundary surface between the mold and the insert S105, S106), and a flow analysis step (S108) for calculating a pressure distribution and a temperature distribution in the cavity by performing a flow analysis based on the analysis model, the pressure distribution and the temperature distribution, and the nodes on the boundary are set. And an insert deformation amount calculating step (S111) for determining the deformation amount of the insert based on the constraint condition.

Furthermore, according to the form of Claim 5 of this invention, the molding process simulation method which concerns on this invention makes a computer perform each step which the deformation | transformation analysis method of said molded article has, It is characterized by the above-mentioned.

  By having a constraint condition setting section or a constraint condition setting step, it is possible to automatically extract the nodes existing on the boundary surface between the mold and the insert and set the constraint conditions, and execute CAE analysis with less work man-hours. It becomes possible.

Also, Jo Tokoro constraints, to the border on nodes, and restricted from moving into the mold along the normal of the boundary surface at the position of the boundary on the node, the reverse direction of the mold direction It is preferable that the tangential movement of the boundary surface at the position of the node on the boundary is free.

According to the second aspect of the present invention, the constraint condition setting unit (20) includes the node extraction unit (21) for extracting the node on the boundary, and the normal of the boundary surface at the position of the node on the boundary. It is preferable to have a normal direction determining unit (22) for determining a direction and a mold direction movement restricting unit (23) for setting the predetermined constraint condition with respect to the boundary node.

Further, according to the fourth or sixth aspect of the present invention, the constraint condition setting step (S104, S105, S106) includes a node extraction step (S104) for extracting a node on the boundary, and a position of the node on the boundary. A normal direction determining step (S105) for determining the normal direction of the boundary surface at, and a mold direction movement restricting step (S106) for setting the above-mentioned predetermined constraint condition for the node on the boundary. preferable.

Furthermore, according to another aspect of the present invention, a recording medium having any one of the above molding process simulation programs is provided.

According to the seventh aspect of the present invention, the input data for generating a predetermined constraint condition to be input to the molding process simulation apparatus for the molded article including the insert fixed to the mold and disposed in the cavity. A generating device is provided. The input data generation apparatus includes a node extraction unit (21) that extracts nodes existing on the boundary surface between the mold and the insert, and a normal direction that determines a normal direction of the boundary surface at the node extracted by the node extraction unit. Restriction condition that restricts movement in the mold direction along the normal direction with the determining unit (22), and allows the movement in the tangential direction of the boundary surface in the reverse direction of the mold direction and the node position. It has a mold direction movement restriction part (23) to set up, It is characterized by the above-mentioned.

  In addition, the code | symbol in the parenthesis attached | subjected to each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

Hereinafter, a molding process simulation apparatus to which the present invention is applied will be described in detail with reference to the drawings.
In the present embodiment, the molding process simulation apparatus performs flow-structure analysis based on weakly coupled analysis to evaluate the deformation of the insert during molding and the shape of the molded product. In the analysis, by automatically setting the constraint condition of the node set on the boundary between the mold and the insert or the cavity surface of the mold, the work man-hour at the time of simulation is greatly reduced and the constraint condition is set. The above-described evaluation can be performed with high accuracy by preventing the human error and updating the constraint conditions appropriately according to the progress of the analysis.

  FIG. 1 shows a functional block diagram of the molding process simulation apparatus 1. The molding process simulation apparatus 1 includes an analysis model generation unit 10, an insert constraint condition setting unit 20, a flow analysis unit 30, a cavity constraint condition setting unit 40, a structure analysis unit 50, a convergence determination unit 60, a storage unit 70, a communication unit 80, and An operation display unit 90 is provided. Then, the analysis model generation unit 10 generates an analysis model such as a molded product in order to perform the flow analysis, and the flow analysis unit 30 calculates the pressure distribution and the temperature distribution at the time of resin filling by the flow analysis. Thereafter, the structural analysis unit 50 calculates the deformation amount of the insert using the constraint conditions set by the insert constraint condition setting unit 20, the calculated pressure distribution, the temperature distribution, and the like. Using the calculation result and the constraint condition set by the cavity constraint condition setting unit 40, the deformation amount of each node in the cavity is calculated, and the analysis model is updated. Such a coupled analysis is repeatedly executed for a period corresponding to the resin filling period, and the convergence determination unit 60 determines whether the coupled analysis is completed.

  The molding process simulation apparatus 1 includes a PC or a workstation, a display, and its peripheral devices. The analysis model generation unit 10, the insert constraint condition setting unit 20, the flow analysis unit 30, the cavity constraint condition setting unit 40, the structure analysis unit 50, and the convergence determination unit 60 are executed on, for example, a central processing unit (CPU) of a PC. Implemented as a program module. Alternatively, the analytical model generation unit 10, the insert constraint condition setting unit 20, the flow analysis unit 30, the cavity constraint condition setting unit 40, the structure analysis unit 50, and the convergence determination unit 60 are provided as numerical arithmetic processors provided separately from the CPU. You may implement as firmware provided. The storage unit 70 includes a semiconductor memory such as RAM and ROM, a magnetic recording medium such as a hard disk, or an optical recording medium such as a CD and DVD. Furthermore, the communication unit 80 includes a communication port, an electronic circuit, driver software, and the like that comply with standards such as Ethernet (registered trademark), USB, SCSI, and RS-232C. Further, the operation display unit 90 includes a display device such as a liquid crystal display and a pointing device such as a mouse.

Hereinafter, each part will be described in detail.
The analysis model generation unit 10 generates an analysis model of a molded product including a die and an insert to be analyzed, and generates input data necessary for executing a flow analysis. For this purpose, the analysis model generation unit 10 includes a shape / condition definition unit 11 and a node definition unit 12.

  The shape / condition definition unit 11 reads the shape data of the mold and the insert stored in advance in the storage unit 70 and generates an analysis model of a molded product including the mold and the insert. Alternatively, the shape data may be acquired from the CAD system through the communication unit 80, and the analysis model may be generated based on the shape data. In the generated analysis model, the outer shape and boundary of the insert, the cavity, and the like are represented as a combination of coordinate values of their end points, a surface or line equation, or a voxel model.

  In addition, the shape / condition definition unit 11 includes physical property data (viscosity, specific volume, thermal conductivity, specific heat, etc.) of the resin, insert and mold filled in the mold, molding conditions (resin injection speed, initial resin Temperature, pressure holding value, pressure holding time, etc.) are read from the storage unit 70. Furthermore, an analysis condition is acquired from the operation display unit 90.

  The node definition unit 12 performs mesh division to perform analysis by the finite element method on the generated analysis model, and sets a large number of nodes. In the present embodiment, mesh division is performed using a tetra mesh. However, a technique such as a hexamesh or a prism mesh may be used instead of the tetramesh. Each set node is associated with identification information for identifying the node (for example, a number uniquely given to each node) and a coordinate value, and temporarily stored in the storage unit 70. Further, the node definition unit 12 may associate attribute information indicating whether each node is set to an insert or a cavity.

  FIG. 2 is a schematic perspective view of the analysis model 200 showing the state of the nodes set in the analysis model. In FIG. 2, a thin plate-like insert 201 exists at a substantially central portion of the analysis model 200, and a cavity 202 that is a region filled with resin exists above and below the insert 201. Further, the insert 201 and the cavity 202 are surrounded by a mold 203. As shown in FIG. 2, one end of the insert 201 is directly inserted into the mold 203 from above and below. The intersection of meshes on the insert 201 and the cavity 202 is a node.

  The insert constraint condition setting unit 20 defines a constraint condition for the nodes existing on the boundary surface between the mold and the insert. Here, the constraint conditions set for the nodes in the insert 201 will be described.

  FIG. 3A is a schematic cross-sectional view of the analysis model 200 taken along the arrow A-A ′ in FIG. 2. The upper part of the right side portion of the insert 201 is in direct contact with the mold 203. On the other hand, the left portion of the insert 201 is disposed without being fixed in the cavity 202. Here, considering the deformation of the insert 201 due to resin filling at the time of molding, the inside of the insert 201 and the boundary portion with the cavity 202 may be deformed in any direction. Therefore, it is not necessary to give a constraint condition to the node 204 existing inside the insert 201 or on the boundary between the insert 201 and the cavity 202. However, the deformation of the mold due to resin filling during molding is negligible. Therefore, the insert 201 may be regarded as not deforming in the direction in which the mold is pressed. Therefore, with respect to the node (node on the boundary) 205 existing on the boundary surface between the insert 201 and the mold, it is fixed in a direction normal to the tangential plane of the boundary surface and in the direction of pressing the mold, In the direction away from the mold along the normal line and the tangential direction of the tangent plane, a constraint condition is set to allow free movement.

  Further, FIG. 3B is a schematic side view of a corner portion of the insert 201 corresponding to the region C of FIG. As shown in FIG. 3B, with respect to the node 206 existing at the corner portion of the insert 201, the direction toward the mold 203 with respect to any normal direction of the two boundary surfaces forming the corner. Is fixed, and a constraint condition is set so that the direction away from the mold 203 can move freely. In the example of FIG. 3B, the movement of the node 206 in the upward direction and the right direction is restricted.

  FIG. 4 shows a functional block diagram of the insert constraint condition setting unit 20. The insert constraint condition setting unit 20 includes an insert / die boundary upper node extracting unit 21, a normal direction determining unit 22, and a mold direction movement limiting unit 23.

  The insert / die boundary node extraction unit 21 extracts the node 205 on the insert / die boundary surface. Therefore, it is determined whether or not each node exists on the boundary surface between the insert and the mold. For this purpose, the node on the insert / die boundary extraction unit 21 acquires the coordinate value of the node of interest from the storage unit 70. Further, in the analysis model, information representing the boundary surface between the insert and the die, for example, a coordinate set of end points of the boundary surface, an equation representing the boundary surface, or voxel data corresponding to the boundary surface is stored from the storage unit 70. get. When the information representing the boundary surface is an equation representing the boundary surface, if the coordinate of the node of interest satisfies the equation, it is determined that the node of interest exists on the insert / die boundary surface. Similarly, when the information representing the boundary surface is a set of coordinates of the end points of the boundary surface, the insert / die boundary upper node extracting unit 21 obtains an equation representing the boundary surface based on the set. Similarly to the above, when the coordinate of the node of interest satisfies the equation, it is determined that the node of interest exists on the insert / die interface.

In addition, when the information representing the boundary surface is voxel data, if the node of interest matches any of those included in the voxel data, it is determined that the node of interest exists on the insert / die boundary. Furthermore, other known methods may be used to determine whether a node is present on the interface between the insert and the mold.
When it is determined that the node of interest is on a plurality of different boundary surfaces, it is determined that the node of interest exists at a corner.
When the target node exists on the boundary surface between the insert and the mold, the insert / die boundary node extraction unit 21 determines the coordinates of the target node and the boundary surface where the target node exists (a plurality of boundary surfaces correspond). In this case, information representing all the corresponding boundary surfaces) is passed to the normal direction determination unit 22.

The normal direction determination unit 22 determines the tangent plane of the boundary surface at the node of interest existing on the insert / die boundary and the normal direction thereof. Since the calculation method of the tangent plane and its normal is well known, it will be briefly described here. The normal direction determination unit 22 acquires the coordinate value of the node of interest in order to determine the tangent plane of the boundary surface at the node of interest. Then, when the insert / die boundary surface is given by an equation, the normal direction determining unit 22 calculates the differential value at the coordinate of the node of interest and determines the inclination in each direction, thereby inserting the insert at the node of interest. -Find an equation that represents the tangent plane of the mold boundary. In addition, when the insert / mold interface is given as voxel data, the position coordinate difference value between the voxel corresponding to the node of interest and the surrounding insert / mold interface voxel is calculated to each direction. The equation representing the tangent plane is obtained by determining the slope of.
When the tangent plane is determined, the normal direction determination unit 22 determines a normal to the tangent plane. Then, the normal direction determining unit 22 uses information representing the tangent plane and the normal (for example, each coefficient of the surface equation representing the tangent plane and each coefficient of the straight line equation representing the normal) as a series of information regarding the node of interest. At the same time, it is passed to the mold direction movement restriction unit 23. When there are a plurality of boundary surfaces with which the node of interest contacts, the tangent plane of each boundary surface and its normal are obtained.

When the mold direction movement restriction unit 23 receives from the normal direction determination unit 22 information indicating a tangent plane and a normal to the node of interest and a series of information about the node of interest, the mold direction movement restriction unit 23 molds along the normal from the node of interest. The restriction condition is defined in which the movement in the direction toward the direction is prohibited and the movement in the opposite direction and the tangential direction is free. Then, the mold direction movement restriction unit 23 associates information indicating the direction of the tangent plane between the insert and the mold and the normal direction thereof with information on the constraint condition stored in the information on the node of interest stored in the storage unit 70. And save.
The insert constraint condition setting unit 20 performs the above process for all nodes. However, when the analysis model is generated, if each node has an attribute indicating whether it exists in the insert or in the cavity, the above processing is performed only for the node in the insert. It may be.

The flow analysis unit 30 calculates the pressure distribution and the temperature distribution in the mold, the insert, and the cavity at the time of molding based on the input data including the analysis model generated by the analysis model generation unit 10. In addition, the flow analysis part 30 performs using a finite element method, for example. As an example, a method realized by 3D-TIMON (registered trademark) manufactured by Toray Engineering Co., Ltd. can be used.
The flow analysis unit 30 passes the obtained pressure distribution and temperature distribution to the structure analysis unit 50.

  The structural analysis unit 50 includes a structural analysis data acquisition unit 51, an insert deformation amount calculation unit 52, and a cavity analysis unit 53. Based on the pressure distribution and the temperature distribution obtained by the flow analysis unit 30, the deformation of the insert Calculate the amount. Furthermore, the amount of resin deformation in the cavity is calculated, and the position of each node is corrected, and the analysis model is updated.

  The structural analysis data acquisition unit 51 creates input data for structural analysis based on the pressure distribution and temperature distribution obtained by the flow analysis unit 30, the constraint conditions for the nodes on the interface between the insert and the mold. Then, the structural analysis input data is passed to the insert deformation amount calculation unit 52.

  The insert deformation amount calculation unit 52 performs structural analysis based on the finite element method using the structural analysis input data, and calculates the deformation amount of the insert. Specifically, based on the pressure distribution obtained by the flow analysis unit 30, the load at an arbitrary location in the mold, the insert, and the cavity is obtained, and the tensile elastic modulus and SS curve are obtained as insert physical properties from these values. Perform structural analysis considering For example, US MSC. MSC. manufactured by software. A method implemented in NASTRAN can be used.

  When the insert deformation amount calculation unit 52 obtains the deformation amount of the insert, the cavity analysis unit 53 uses the deformation amount and the constraint conditions for the nodes on the cavity surface of the mold given by the cavity constraint condition setting unit 40. Then, structural analysis is performed based on the finite element method, and the amount of nodal displacement in the cavity is calculated. Then, each node is moved according to the displacement amount, and the analysis model is updated.

Note that the cavity analysis unit 53 also uses the US MSC. MSC. manufactured by software. A method implemented in NASTRAN can be used. The setting of the constraint conditions for the nodes on the cavity surface of the mold will be described later.
The updated analysis model is stored in the storage unit 70 so that it can be subsequently used for coupled analysis or as a simulation result.

  The cavity constraint condition setting unit 40 defines a constraint condition at a node on the cavity surface of the mold (that is, the boundary surface between the mold and the cavity). Here, the constraint conditions set at the nodes on the cavity surface of the mold will be described.

  FIG. 5 is a schematic cross-sectional view taken along the line B-B ′ in FIG. 2. The left and right ends of the insert 201 and the cavity 202 are in contact with the mold 203. Here, it is assumed that the insert 201 is deformed and moved upward due to resin filling during molding. In this case, when a constraint condition is applied to the node 207 existing on the cavity surface of the mold so as not to move in any direction, the insert 201 is moved by the movement of the insert 201 as shown in FIG. Above, the interval between the nodes becomes very narrow, or in some cases, the vertical positional relationship between the node 204 set in the insert 201 and the node 207 on the cavity surface of the mold is reversed. For this reason, the structural analysis in the cavity may not be performed normally.

  Therefore, the cavity constraint condition setting unit 40 can freely move in the tangential direction of the tangent plane of the cavity surface at the node 207 with respect to the node 207 on the cavity surface of the mold, and the tangent plane thereof. The restraint condition to fix is given to the normal direction. By setting such a constraint condition, the node 207 can be moved corresponding to the movement of the insert 201. Therefore, the above problems do not occur.

  FIG. 6 shows a functional block diagram of the cavity constraint condition setting unit 40. The cavity constraint condition setting unit 40 includes a mold cavity surface upper node extraction unit 41, a normal direction determination unit 42, and a normal direction movement restriction unit 43.

  The node extraction part 41 on the mold cavity surface extracts the node 207 on the cavity surface of the mold. The extraction of the node 207 can be executed by applying the same process as that of the insert / die boundary upper node extracting unit 21 to the cavity surface of the mold.

  The normal direction determination unit 42 determines the tangent plane of the boundary surface at the node 207 existing on the cavity surface of the mold and the normal direction thereof. The determination of the normal direction of the node plane and the tangent plane can be performed by the same method as that of the normal direction determination unit 22 described above, and thus detailed description thereof is omitted here. The normal direction determination unit 42 passes information representing the tangent plane and the normal along with a series of information regarding the nodes 207 to the normal direction movement restriction unit 43.

When the normal direction movement restricting unit 43 receives from the normal direction determining unit 42 information indicating the tangent plane and normal to the node 207 and a series of information regarding the node 207, the normal direction movement restricting unit 43 moves in the direction along the normal direction. And restricting the movement of the tangential plane in the tangential direction is defined. Then, the normal direction movement restriction unit 43 includes information indicating the direction of the tangent plane of the cavity surface of the mold and the normal direction thereof, and information indicating the constraint condition in the information of the node 207 stored in the storage unit 70. Associate and save.
The cavity constraint condition setting unit 40 performs the above process for all nodes. However, when generating an analysis model, if each node is given an attribute indicating whether it exists in the insert or in the cavity, refer to that attribute and You may make it perform said process only about a node.

  The convergence determination unit 60 determines whether or not the flow-structure analysis executed by each of the above units has converged. Therefore, the convergence determination unit 60 repeatedly executes the above-described flow-structure analysis process a predetermined number of times obtained by dividing a period corresponding to the time from the start of filling of the resin into the cavity to the completion of filling at predetermined time intervals. To do. Then, when reaching a time point at which it can be evaluated that the filling is completed, the flow-structure analysis process is terminated. For example, when the time required from the start of filling of the resin to the completion of filling is 1 second and a change per 1/100 second is simulated by one flow-structure analysis, the convergence determination unit 60 may The structural analysis process is repeated 100 times. Note that a more detailed analysis can be performed by shortening the elapsed time corresponding to one flow-structure analysis process and increasing the number of repetitions.

  If the convergence determination unit 60 determines that the flow-structure analysis has converged, the convergence analysis unit 60 causes the operation display unit 90 to display the latest analysis model stored in the storage unit 70 as an analysis result. Alternatively, information regarding the analysis model may be transmitted to an external storage server or the like through the communication unit 80.

  7 and 8 are flowcharts of a simulation process executed by the molding process simulation apparatus 1. The simulation process is controlled by a program read into a PC or a workstation constituting the molding process simulation apparatus 1, and each step described below is executed.

  As shown in FIG. 7, first, when the analysis is started, the analysis model generation unit 10 reads the shape data of the molded product to be analyzed from the storage unit 70 or is externally connected through the communication unit 80. Obtain from CAD system. Then, an analysis model is generated (step S101). Also, physical property data, molding conditions, analysis conditions, etc. of the mold, insert and resin are acquired, and input data for flow analysis is created.

Next, the analysis model generation unit 10 meshes the analysis model and sets a large number of nodes in the analysis model (step S102).
Next, the insert constraint condition setting unit 20 selects an arbitrary node from the set nodes and sets it as a focused node (step S103). When generating an analysis model, if an attribute for identifying whether each node is set as an insert or a cavity is given, in step 103, only the nodes set in the insert are used. , Select the node of interest. Then, in the insert / die boundary node extracting unit 21, it is determined whether or not the node of interest exists on the boundary surface between the insert and the die (step S104). When the focused node does not exist on the boundary surface, the insert constraint condition setting unit 20 does not set a constraint condition for the focused node (that is, the focused node can freely move in any direction). Then, the control is returned to before step S103, and a new node of interest is selected from the nodes that have not been the node of interest until then.

  On the other hand, if it is determined in step S104 that the node of interest exists on the boundary surface, the normal direction determination unit 22 determines the tangent plane of the boundary surface and the normal direction of the node of interest (step S105). . Further, the mold direction movement restriction unit 23 prohibits movement in the direction toward the mold along the normal line direction with respect to the node of interest and allows it to move freely in other directions. Conditions are set (step S106).

  Thereafter, the insert constraint condition setting unit 20 determines whether or not all the nodes have been examined on the boundary surface between the insert and the mold (step S107). Then, if there is a node that is not yet the node of interest, control is returned to step S103.

  On the other hand, if it is determined in step S107 that all the nodes have been examined, the input data is passed to the flow analysis unit 20. Then, the flow analysis unit 30 performs flow analysis and calculates a pressure distribution and a temperature distribution for the analysis model included in the input data (step S108). Then, the calculated pressure distribution and temperature distribution are passed to the structure analysis unit 50.

  After that, when the structure analysis unit 50 acquires the pressure distribution and the temperature distribution, the structure analysis data acquisition unit 51 calculates the surface load of the insert (step S109). Then, input data for structural analysis is created based on the surface load, temperature distribution, physical property data of the insert, and constraint conditions set for the nodes (step S110).

  As shown in FIG. 8, when the structural analysis input data is created, the insert deformation amount calculation unit 52 of the structural analysis unit 50 performs structural analysis, and each of the deformation amount of the insert and each of the inserts included in the deformed insert is included. The position of the node is obtained (step S111).

  Next, the cavity constraint condition setting unit 40 selects an arbitrary node from the set nodes and sets it as a focused node (step S112). Then, in the mold cavity surface node extraction unit 41, it is determined whether or not the node of interest exists on the cavity surface of the mold (step S113). When the focused node does not exist on the cavity surface of the mold, the cavity constraint condition setting unit 40 does not set a constraint condition for the focused node (that is, the focused node can freely move in any direction). . Then, the control is returned to before step S112, and a new node of interest is selected from the nodes that have not been the node of interest until then. In addition, when generating an analysis model, if an attribute for identifying whether each node is set as an insert or a cavity is given, in step 112, only the nodes set in the cavity are used. , Select the node of interest.

  On the other hand, if it is determined in step S113 that the target node exists on the cavity surface of the mold, the normal direction determination unit 42 determines the tangent plane of the cavity surface at the target node and the normal direction ( Step S114). Further, the normal direction movement restriction unit 43 sets a constraint condition for prohibiting movement in the normal direction for the node of interest and allowing it to move freely in other directions (step S115).

  Thereafter, the cavity restraint condition setting unit 40 determines whether or not all the nodes are present on the cavity surface of the mold (step S116). Then, if there is a node that has not yet become the node of interest, control is returned to before step S112.

  On the other hand, when it is determined in step S116 that all the nodes have been examined, the structural analysis unit 40 performs a structural analysis with reference to the constraint conditions set for the nodes in the cavity, and the deformation amount of the resin in the cavity Is calculated. Depending on the amount of deformation, the position of the node in the cavity is moved to update the analysis model (step S117). The updated analysis model is stored in the storage unit 70.

  Finally, the convergence determination unit 60 determines whether or not the coupled analysis performed in steps S103 to S117 is repeated a predetermined number of times (for example, 100 times) (step S118). When the number of coupled analyzes has not reached the predetermined number, the convergence determination unit 60 returns control to before step S103. If the deformation amount is expected to be small, the control may be returned to before step S108.

  On the other hand, when the number of coupled analyzes reaches a predetermined number, the simulation process is terminated. If necessary, the analysis model stored in the storage unit 70 is displayed on the operation display unit 90 or output to an external device through the communication unit 80.

  As described above, the molding process simulation apparatus to which the present invention is applied automatically sets the constraint conditions for the nodes existing on the boundary surface between the mold and the insert, greatly increasing the work man-hours at the time of analysis. Can be reduced. In addition, since the constraint conditions can be reset each time the flow-structure coupled analysis is repeated, for example, the part where the mold and the insert were in contact at the beginning of the analysis became non-contact due to the deformation of the insert. Even when it is necessary to correct the constraint condition of the node corresponding to the contact portion, the simulation can be performed accurately.

  In addition, by setting a constraint condition that fixes only the normal direction of the cavity surface with respect to the nodes on the cavity surface of the mold, it is possible to prevent inconsistencies in the positional relationship between the nodes due to the deformation of the insert. Can be simulated accurately.

  The embodiments described above are for explaining the present invention, and the present invention is not limited to these embodiments. For example, the present invention can be applied not only to injection molding but also to compression molding. Furthermore, the present invention can also be applied to aluminum die casting.

  Moreover, in said embodiment, the flow-structure coupling analysis was performed using the finite element method using the node group set by dividing into meshes. However, the present invention does not perform mesh division, but arbitrarily sets a node group, and sets the analysis region using a technique such as voxel division or Delaunay division for the node group. It can also be applied to those performing synthesis analysis.

In the above-described embodiment, the flow-structure analysis of the present invention is performed based on the weakly coupled analysis. However, the analysis may be performed based on the strongly coupled analysis.
Furthermore, the setting of the constraint condition for the node on the cavity surface of the mold may be performed simultaneously with the setting of the constraint condition for the node on the boundary surface between the mold and the insert.

In addition, a program for causing a PC or the like to execute the above-described simulation of the molding process can be stored and carried on a recording medium such as a CD. Is possible.
In addition, a function to set the above-mentioned constraint conditions at the nodes on the mold / insert boundary or on the cavity surface of the mold is provided for existing simulation devices or simulation programs that perform flow-structure analysis. Therefore, it is possible to create an input data generation device or an input data generation program having only the functions of the insert constraint condition setting unit and the cavity constraint condition setting unit.

  As described above, the molding process simulation apparatus to which the present invention is applied is appropriately optimized within the scope of the present invention.

It is a functional block diagram of a molding process simulation apparatus to which the present invention is applied. It is a schematic perspective view of the analysis model of the molded product to be simulated. (A) is a schematic sectional drawing in arrow A-A 'of the analytical model of FIG. 2, (b) is an enlarged view of an insert edge part. It is a functional block diagram of an insert constraint condition setting unit. (A) is a schematic sectional drawing in the arrow BB 'of the analysis model of FIG. 2, (b) is a state of the node accompanying insert deformation when the node on the cavity surface of the mold is fixed FIG. It is a functional block diagram of a cavity constraint condition setting unit. It is a flowchart which shows the operation | movement procedure of the shaping | molding process simulation apparatus to which this invention is applied. It is a flowchart which shows the operation | movement procedure of the shaping | molding process simulation apparatus to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molding process simulation apparatus 10 Analysis model production | generation part 11 Shape / condition definition part 12 Node definition part 20 Insert constraint condition setting part 21 Insert / mold boundary upper node extraction part 22 Normal direction determination part 23 Mold direction movement restriction part 30 Flow analysis part 40 Cavity constraint condition setting part 41 Mold cavity surface nodal point extraction part 42 Normal direction determination part 43 Normal direction movement restriction part 50 Structural analysis part 51 Structural analysis data acquisition part 52 Insert deformation amount calculation part 53 Cavity analysis Unit 60 Convergence determining unit 70 Storage unit 80 Communication unit 90 Operation display unit 200 Analysis model 201 Insert 202 Cavity 203 Mold 204 to 207 Node

Claims (7)

An analysis model generation unit (10) that generates an analysis model of a molded article including an insert that is fixed to a mold and disposed in a cavity, and sets a plurality of nodes in the analysis model;
A constraint condition setting unit (20) for setting a predetermined constraint condition on a boundary node existing on a boundary surface between the mold and the insert;
A flow analysis unit (30) for performing a flow analysis based on the analysis model and calculating a pressure distribution and a temperature distribution in the cavity;
An insert deformation amount calculation unit (52) for determining the deformation amount of the insert based on the pressure distribution and the temperature distribution calculated by the flow analysis and the constraint condition set at the node on the boundary;
I have a,
The predetermined constraint condition restricts movement to the mold direction along a normal line of the boundary surface at a position of the boundary node with respect to the boundary node, and is opposite to the mold direction. And tangential movement of the boundary surface at the position of the node on the boundary is free.
A molding process simulation apparatus characterized by that. The constraint condition setting unit (20)
A node extraction unit (21) for extracting the nodes on the boundary;
A normal direction determining unit (22) for determining a normal direction of the boundary surface at the position of the node on the boundary;
Limiting movement in the mold direction along the normal direction of the boundary surface with respect to the boundary node, and tangent to the boundary surface in the reverse direction of the mold direction and the position of the boundary node A mold direction movement restriction unit (23) for setting a constraint condition to freely move the direction;
The molding process simulation apparatus according to claim 1 , comprising: An analysis model generation step (S101, S102) for generating an analysis model of a molded article including an insert fixed in a mold and disposed in a cavity, and setting a plurality of nodes in the analysis model;
A constraint condition setting step (S104, S105, S106) for setting a predetermined constraint condition on a boundary node existing on the boundary surface between the mold and the insert;
A flow analysis step (S108) for performing a flow analysis based on the analysis model and calculating a pressure distribution and a temperature distribution in the cavity;
Insert deformation amount calculating step (S111) for determining the deformation amount of the insert based on the pressure distribution and temperature distribution calculated by the flow analysis step and the constraint condition set at the boundary node.
I have a,
The predetermined constraint condition restricts movement to the mold direction along a normal line of the boundary surface at a position of the boundary node with respect to the boundary node, and is opposite to the mold direction. And tangential movement of the boundary surface at the position of the node on the boundary is free.
A method for analyzing deformation of a molded product characterized by the above. The constraint condition setting step (S104, S105, S106)
A node extracting step (S104) for extracting the nodes on the boundary;
A normal direction determination step (S105) for determining a normal direction of the boundary surface at the position of the boundary node;
Limiting movement in the mold direction along the normal direction of the boundary surface with respect to the boundary node, and tangent to the boundary surface in the reverse direction of the mold direction and the position of the boundary node A mold direction movement restriction step (S106) for setting a constraint condition to freely move the direction;
The deformation | transformation analysis method of the molded article of Claim 3 which has these. An analysis model generation step (S101, S102) for generating an analysis model of a molded article including an insert fixed in a mold and disposed in a cavity, and setting a plurality of nodes in the analysis model;
A constraint condition setting step (S104, S105, S106) for setting a predetermined constraint condition on a boundary node existing on the boundary surface between the mold and the insert;
A flow analysis step (S108) for performing a flow analysis based on the analysis model and calculating a pressure distribution and a temperature distribution in the cavity;
Insert deformation amount calculating step (S111) for determining the deformation amount of the insert based on the pressure distribution and temperature distribution calculated by the flow analysis step and the constraint condition set at the boundary node.
To the computer ,
The predetermined constraint condition restricts movement to the mold direction along a normal line of the boundary surface at a position of the boundary node with respect to the boundary node, and is opposite to the mold direction. And tangential movement of the boundary surface at the position of the node on the boundary is free.
Molding process simulation program. The constraint condition setting step (S104, S105, S106)
A node extracting step (S104) for extracting the nodes on the boundary;
A normal direction determination step (S105) for determining a normal direction of the boundary surface at the position of the boundary node;
Limiting movement in the mold direction along the normal direction of the boundary surface with respect to the boundary node, and tangent to the boundary surface in the reverse direction of the mold direction and the position of the boundary node A mold direction movement restriction step (S106) for setting a constraint condition to freely move the direction;
The molding process simulation program according to claim 5 . Pressure distribution calculated by generating an analytical model of a molded product including an insert fixed in a mold and arranged in a cavity, setting a plurality of nodes in the analytical model, and performing flow analysis based on the analytical model And an input data generation device for generating the predetermined constraint condition to be input to a molding process simulation device for obtaining the deformation amount of the insert based on the temperature distribution and the predetermined constraint condition set at the plurality of nodes,
A node extraction unit (21) for extracting a node existing on a boundary surface between the mold and the insert;
A normal direction determination unit (22) for determining a normal direction of the boundary surface at the position of the node extracted by the node extraction unit;
The node extracted by the node extraction unit is restricted from moving in the mold direction along the normal direction, and the opposite direction of the mold direction and the boundary surface at the position of the node are restricted. A mold direction movement restriction unit (23) for setting a constraint condition to freely move in the tangential direction;
An input data generation device comprising:

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