CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority to Japanese Patent Application No. 2006-293961 filed on Oct. 30, 2006, which is incorporated herein by reference in its entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a machining simulation system including a numerical control apparatus configured to control a machining motion of a machine tool and a machining simulation apparatus configured to perform a simulation prior to an actual machining operation.  
         [0004]     2. Description of the Related Art  
         [0005]     A numerical control apparatus can control a machine tool according to numerical control information input by an operator of a production engineering division who can use a machining simulation apparatus. The machining simulation apparatus has a machining simulation function (including an interference check function) for checking an motion of a machine tool to be realized according to a machining command involved in the numerical control information. The machining simulation apparatus is, for example, constituted by a personal computer that can realize highly advanced performances according to software programs.  
         [0006]     On the other hand, a numerical control apparatus of a worksite enables an operator to use a machining simulation function. For example, the machining simulation function provided by a numerical control apparatus includes checking beforehand an motion of a machine tool (including an interference check) to be used in a machining operation. Furthermore, the machining simulation function provided by the numerical control apparatus may include graphically displaying the progress of an actual machining operation if an operator cannot visually check the operation inside a machine tool after a door of the machine tool is closed.  
         [0007]     After numerical control information has been determined by an operator of a production engineering division using the machining simulation apparatus, an operator of a worksite may modify the numerical control information according to machining processing environments. As a result, setup positions of a tool and a material according to the corrected numerical control information may differ from those determined by the operator of the production engineering division.  
         [0008]     For example, a worksite environment may prevent preparation of a tool designated by an operator of the production engineering division, or may make it impossible to install the tool at a designated position. Accordingly, before performing actual machining work, an operator of the worksite uses the machining simulation function of the numerical control apparatus that can check an motion of the machine tool to be performed according to the numerical control information corrected according to the machining processing environment of the worksite.  
         [0009]      FIG. 6  illustrates a conventional machining simulation apparatus  100  that can be used in a production engineering division.  FIG. 7  illustrates a conventional numerical control apparatus provided on a worksite that can control a machine tool.  
         [0010]     A numerical control information input unit  1  enables an operator to input numerical control information (e.g., machining simulation data and interference check data) via a keyboard  19 . A numerical control information storage memory  2  stores the input numerical control information. A mechanical structure storage memory  3  stores various shape models including a tool rest, a main spindle, and a table of a machine tool, which are used for a machining simulation or an interference check.  
         [0011]     A material shape setting/display unit  4  enables an operator to input a material shape model used in a machining simulation via the keyboard  19 . A material shape storage memory  5  stores the input material shape model. The material shape setting/display unit  4  causes the display device  18  to display an operation screen that instructs an operator to input a material shape model and enables the user to confirm the input material shape model.  FIG. 8  illustrates an exemplary operation screen displayed by the display device  18  according to the processing performed by the material shape setting/display unit  4 .  
         [0012]     A material setup position setting/display unit  6  enables an operator to input a material setup position via the keyboard  19 . The material setup position indicates a position where the input material shape model is placed on a machine tool to be subjected to the machining simulation. A material setup position storage memory  7  stores the input material setup position. The material setup position setting/display unit  6  causes the display device  18  to display an operation screen that instructs an operator to input a material setup position and enables the user to confirm the input material setup position.  FIG. 9  illustrates an exemplary operation screen displayed by the display device  18  according to the processing performed by the material setup position setting/display unit  6 .  
         [0013]     If a lathe grips and holds a material with a chuck attached to a main spindle, a relative distance between a reference point on a right-edge surface of the main spindle and a reference point of a material model can define the material setup position. If a machining center fixes and holds a material with a jig on a table, a relative distance between a predetermined reference point of the table and a reference point of a material model can define the material setup position.  
         [0014]     A tool shape setting/display unit  8  enables an operator to input a tool shape model used in a machining simulation via the keyboard  19 . A shape storage memory  9  stores the input tool shape model. The tool shape setting/display unit  8  causes the display device  18  to display an operation screen that instructs an operator to input a tool shape model and enables the user to confirm the input tool shape model.  FIG. 10  illustrates an exemplary operation screen displayed by the display device  18  according to the processing performed by the tool shape setting/display unit  8 .  
         [0015]     Furthermore, a tool setup position setting/display unit  10  enables an operator to input a tool setup position via the keyboard  19 . The tool setup position indicates a position at which the input tool shape model is placed on a machine tool to be subjected to the machining simulation. A tool setup position storage memory  11  stores the input tool setup position. The tool setup position setting/display unit  10  causes the display device  18  to display an operation screen that instructs an operator to input a tool setup position and enables the user to confirm the input tool setup position.  FIG. 11  illustrates an exemplary operation screen displayed by the display device  18  according to the processing performed by the tool setup position setting/display unit  10 .  
         [0016]     If a lathe allows the attachment of a plurality of tools on a tool rest, the tool setup position may indicate the position of each tool on the tool rest or indicate a dimension relating to the installation, such as a relative distance between a reference point of the tool rest and a cutting edge point of a tool shape model. If a machining center has a main spindle to which a tool can be attached, the tool setup position may indicate a relative distance between a reference point on an edge surface of the main spindle and a cutting edge point of a tool shape model.  
         [0017]     Similarly, a jig shape setting/display unit  12  enables an operator to input a jig shape model used in a machining simulation via the keyboard  19 . A jig shape storage memory  13  stores the input jig shape model. The jig shape setting/display unit  12  causes the display device  18  to display an operation screen that instructs an operator to input a jig shape model and enables the user to confirm the input jig shape model.  FIG. 12  illustrates an exemplary operation screen displayed by the display device  18  according to the processing performed by the jig shape setting/display unit  12 .  
         [0018]     If this system is applied to a lathe capable of gripping and holding a material with a chuck attached to a main spindle, the setup position of a chuck (i.e., jig) can be accurately determined. In such a case, the system may not include a unit configured to perform setting/display processing for a jig and a storage memory that can store setting data.  
         [0019]     As described above, machining simulation data and interference check data (i.e., material shape model, tool shape model, setup position, and jig shape model) are stored in respective storage memories.  
         [0020]     An motion simulation unit  14  reads the numerical control information from the numerical control information storage memory  2  and performs an motion simulation. The motion simulation includes reading a command relating to a machining operation involved in the numerical control information and generating a pseudo operation signal corresponding to a axis moving signal of a tool rest, a main spindle, or a table.  
         [0021]     A graphic simulation unit  15  reads the material shape model from the material shape storage memory  5  and locates the retrieved material shape model on a desired position of the machine tool subjected to a graphic simulation according to the material setup position read from the material setup position storage memory  7 . Then, the graphic simulation unit  15  reads the tool shape model from the tool shape storage memory  9  and locates the retrieved tool shape model on a desired position of the machine tool subjected to a graphic simulation according to the tool setup position read from the tool setup position storage memory  11 .  
         [0022]     Furthermore, the graphic simulation unit  15  reads the jig shape model from the jig storage memory  13  and locates the readout jig shape model on a predetermined position of the machine tool subjected to graphic simulation. Furthermore, the graphic simulation unit  15  performs a pseudo sequential motion of a tool rest, a main spindle, and a table that hold the tool shape model and the material shape model according to a pseudo operation signal received from the motion simulation unit  14 . The display device  18  displays a state of this graphic simulation on its screen according to the processing of the graphic display unit  17 .  
         [0023]     An interference check unit  16  performs an interference check for determining whether the shift movement of a tool rest, a main spindle, or a table (i.e., simulation result by the graphic simulation unit  15 ) might interfere with a material, a tool, or a jig. Then, if the interference check unit  16  determines that any interference is possible, the display device  18  presents a graphic display (e.g., warning message) indicating the interference to an operator.  
         [0024]      FIG. 7  illustrates an exemplary configuration of a numerical control apparatus  200 . A numerical control information input unit  51  enables an operator to input numerical control information via a keyboard  72 . A numerical control information storage memory  52  stores the input numerical control information.  
         [0025]     The numerical control apparatus  200  comprises various units similar to the above-described units of the machining simulation apparatus  100 . More specifically, a mechanical structure storage memory  57  is functionally similar to the mechanical structure storage memory  3 . A material shape setting/display unit  58  is functionally similar to the material shape setting/display unit  4 . A material shape storage memory  59  is functionally similar to the material shape storage memory  5 . A material setup position setting/display unit  60  is functionally similar to the material setup position setting/display unit  6 . A material setup position storage memory  61  is functionally similar to the material setup position storage memory  7 . A tool shape setting/display unit  62  is functionally similar to the tool shape setting/display unit  8 . A tool shape storage memory  63  is functionally similar to the tool shape storage memory  9 . A tool setup position setting/display unit  64  is functionally similar to the tool setup position setting/display unit  10 . A tool setup position storage memory  65  is functionally similar to the tool setup position storage memory  11 . A jig shape setting/display unit  66  is functionally similar to the jig shape setting/display unit  12 . A jig shape storage memory  67  is functionally similar to the jig shape storage memory  13 .  
         [0026]     In the example described, the system employs similar arrangements for setting/displaying/storing the material/tool shape models, the material/tool setup positions, and the jig shape model in order to simplify the description. In this respect, a numerical control apparatus and a machining simulation apparatus of a machining simulation system according to the present invention are not limited to similar existing units.  
         [0027]     As described above, machining simulation data and interference check data (i.e., material shape model, tool shape model, setup position, and jig shape model) are stored in respective storage memories.  
         [0028]     A numerical control information interpretation unit  53  reads the numerical control information from the numerical control information storage memory  52  and interprets the retrieved information. The numerical control information interpretation unit  53  transmits a axis movement command involved in the interpreted numerical control information to a axis movement command execution unit  54 . Furthermore, the numerical control information interpretation unit  53  transmits other commands (e.g., a main spindle rotation command and a cutting fluid discharge command) to related execution units (not illustrated).  
         [0029]     The axis movement command execution unit  54  generates a axis moving signal according to the axis movement command. In an actual work control, the axis movement command execution unit  54  transmits the generated axis moving signal to a servo control unit  55 . The servo control unit  55  controls a servo motor  56  according to the axis moving signal. The servo motor  56  performs a axis moving operation for a tool rest, a main spindle, or a table of the machine tool.  
         [0030]     If the numerical control apparatus  200  performs a machining simulation or an interference check concurrently with an actual work control, the axis movement command execution unit  54  transmits a axis moving signal to a graphic simulation unit  68 . The graphic simulation unit  68  executes processing similar to that of the above-described graphic simulation unit  15  of the machining simulation apparatus  100 . An interference check unit  69 , a graphic display unit  70 , and a display device  71  are functionally similar to those of the interference check unit  16 , the graphic display unit  17 , and the display device  18  of the machining simulation apparatus  100 .  
         [0031]     The interference check unit  69 , if any interference is detected, transmits a stop signal to the servo control unit  55 . The servo control unit  55  stops the axis movement of the tool rest, the main spindle, or the table.  
         [0032]     If the numerical control apparatus  200  performs only a machining simulation or an interference check without performing an actual work control, the axis movement command execution unit  54  transmits a axis moving signal only to the graphic simulation unit  68  (i.e., does not transmit a axis moving signal to the servo control unit  55 ). Therefore, the servo motor  56  does not perform a axis moving operation for an actual work.  
         [0033]     As described above, according to a conventional system, the machining simulation apparatus  100  provided in a production engineering division performs a machining simulation including an interference check prior to an actual machining operation. On the other hand, the numerical control apparatus  200  provided on a worksite performs a machining simulation including an interference check based on numerical control information reflecting actual machining conditions and corrections made by an operator of a worksite.  
         [0034]     In other words, the production engineering division and the worksite independently perform the machining simulations based on different conditions. Therefore, the machining simulation apparatus provided in the production engineering division and the numerical control apparatus provided on the worksite are unable to mutually readjust the differences in the machining simulation conditions.  
         [0035]     If the numerical control apparatus provided on the worksite repeatedly performs a machining simulation reflecting the specificity of the worksite (e.g., corrections according to machining conditions), simulation contents of the machining simulation apparatus provided in the production engineering division gradually separate from simulation contents of the numerical control apparatus provided on the worksite. The above-described conventional system cannot readjust the separated simulation contents and simulation conditions.  
         [0036]     According to the description of the system disclosed in Japanese Patent Laid-open Application No. 5-42446, an apparatus performing an interference check can cooperate with a numerical control apparatus. More specifically, the numerical control apparatus actually moves a movable member and detects a position where the movable member interferes with a workpiece. The numerical control apparatus transfers the obtained positional information to a CAD/CAM apparatus having an interference check function.  
         [0037]     However, in the above-described conventional system, the numerical control apparatus performs only a machining processing control and is simply combined with the CAD/CAM apparatus having a simulation function. In other words, the above-described conventional system cannot perform an adjustment between the machining simulation apparatus performing a simulation prior to an actual machining operation and the numerical control apparatus performing a simulation reflecting worksite information.  
         [0038]     As described above, each of the machining simulation apparatus and the numerical control apparatus performs a machining simulation or an interference check. In this case, as apparent from the foregoing description, an operator of the machining simulation apparatus and an operator of the numerical control apparatus are required to independently set a material shape model, a material setup position, a tool shape model, and a tool setup position.  
         [0039]     Accordingly, the following problems arise:  
         [0000]     *1: Even after a material shape model, a material setup position, a tool shape model, and a tool setup position have been set for the machining simulation apparatus, similar data setting is required for the numerical control apparatus.  
         [0000]     *2: An operator of the worksite is required to input all of the data required for the numerical control apparatus, thereby increasing the likelihood of data entry or setting errors.  
         [0040]     *3: An operator of the machining simulation apparatus side is required to generate a paper document or other medium that describes or indicates preparatory planning information including setting data contents, such as a material shape model, set by a machining simulation apparatus and send it to the operator of the numerical control apparatus side.  
         [0041]     *4: Any data corrected by the numerical control apparatus side according to a machining processing environment cannot be easily transmitted to the machining simulation apparatus side. Such corrected data cannot be transmitted unless a paper document or other medium is used.  
         [0042]     *5: The machining simulation apparatus side cannot collect the data actually used in a machining operation and cannot establish a reusable database including such correction data. As a result, an environment of the machining simulation apparatus cannot be improved so as to fit to the environment of the worksite.  
       SUMMARY OF THE INVENTION  
       [0043]     To solve the above-described problems, the present invention provides a machining simulation system including a numerical control apparatus capable of performing a machining simulation with a tool shape model and a material shape model and a machining simulation apparatus capable of performing a machining simulation with the tool shape model and the material shape model. The machining simulation apparatus can communicate with the numerical control apparatus via a communication unit or a storage medium so as to mutually transmit and receive data. The machining simulation apparatus includes a shape model output unit configured to output the tool shape model and the material shape model that can be used in the numerical control apparatus, and a setup position output unit configured to output a tool setup position and a material setup position on a machine tool. The numerical control apparatus includes a shape model reading unit configured to read the shape model output from the shape model output unit, and a setup position reading unit configured to read the setup position output from the setup position output unit.  
         [0044]     Furthermore, the numerical control apparatus may include a shape model output unit configured to output a tool shape model and material shape model that can be used in the machining simulation apparatus, and a setup position output unit configured to output a tool setup position and a material setup position on a machine tool. The machining simulation apparatus includes a shape model reading unit configured to read the shape model output from the shape model output unit, and a setup position reading unit configured to read the setup position output from the setup position output unit.  
         [0045]     Furthermore, the machining simulation apparatus may further include a relating unit configured to relate numerical control information stored in the machining simulation apparatus, the shape model retrieved by the shape model reading unit, and the setup position retrieved by the setup-position reading unit, and store the related data so as to be reused.  
         [0046]     Moreover, a machining simulation system includes a machining simulation apparatus and a numerical control apparatus each having a machining simulation function using a tool shape model and a material shape model, which can communicate with each other via a communication unit or a storage medium so as to mutually transmit and receive data. The machining simulation apparatus includes a unit configured to output preparatory planning information including the tool or material shape model and a setup position on a machine tool which are used in a machining simulation operation or in an interference check operation. The numerical control apparatus includes a unit configured to read and display the preparatory planning information.  
         [0047]     According to the present invention, the machining simulation apparatus and the numerical control apparatus can mutually transmit and receive tool/material shape models and tool/material setup positions on a machine tool via a communication unit or a storage medium. Furthermore, the machining simulation apparatus can relate the numerical control information with the tool/material shape models and tool/material setup positions corrected by the numerical control apparatus and can store the related data so as to be reused.  
         [0048]     Furthermore, the numerical control apparatus side can display preparatory planning information including a tool or material shape model and a setup position on a machine tool which are used in the machining simulation apparatus.  
         [0049]     In this manner, the present invention enables the numerical control apparatus of a worksite to use shape model information and setup positional data set by the machining simulation apparatus of a production engineering division. Thus, an operator of the production engineering division is not required to generate a paper document or other medium that describes or indicates the preparatory planning information.  
         [0050]     With the present invention, an operator of the worksite is not required to set all of the data for the numerical control apparatus. Because the setting work for the numerical control apparatus is substantially limited to setting a small amount of correction data reflecting a machining processing environment, the setting work is reduced and simplified, which in turn reduces the number and frequency of setting errors.  
         [0051]     Moreover, the correction data reflecting a machining processing environment generated by the numerical control apparatus side can be easily fed back to the machining simulation apparatus side. Thus, the production engineering division can store the feedback data as a database usable for the machining simulation apparatus. As a result, an environment of the machining simulation apparatus can be improved so as to fit to the environment of the worksite. Thus, the present invention can simplify a work for adjusting the environment of the machining simulation apparatus according to the processing environment of the worksite. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0052]     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention and, together with the description, serve to explain the principles of the invention, in which:  
         [0053]      FIG. 1  is a block diagram illustrating a numerical control apparatus of a machining simulation system according to an embodiment of the present invention;  
         [0054]      FIG. 2  is a block diagram illustrating a machining simulation apparatus of a machining simulation system according to an embodiment of the present invention;  
         [0055]      FIG. 3  is a block diagram illustrating a numerical control apparatus of a machining simulation system according to an embodiment of the present invention;  
         [0056]      FIG. 4  is a block diagram illustrating a machining simulation apparatus of a machining simulation system according to an embodiment of the present invention;  
         [0057]      FIG. 5  illustrates an exemplary preparatory planning information display screen;  
         [0058]      FIG. 6  is a block diagram illustrating a conventional machining simulation apparatus;  
         [0059]      FIG. 7  is a block diagram illustrating a conventional numerical control apparatus;  
         [0060]      FIG. 8  illustrates a material shape setting/display screen according to an embodiment of the present invention;  
         [0061]      FIG. 9  illustrates a material setup position setting/display screen according to an embodiment of the present invention;  
         [0062]      FIG. 10  illustrates a tool shape setting/display screen according to an embodiment of the present invention;  
         [0063]      FIG. 11  illustrates a tool setup position setting/display screen according to an embodiment of the present invention; and  
         [0064]      FIG. 12  illustrates a jig shape setting/display screen according to an embodiment of the present invention. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENT  
       [0065]      FIGS. 1 and 2  are block diagrams of an exemplary embodiment of the present invention. In  FIGS. 1 and 2 , functional components similar to those described in  FIGS. 6 and 7  are denoted by the same reference numerals.  
         [0066]     In a machining simulation apparatus  101 , a material shape output unit  20  generates a material shape model and outputs the generated model to a network transmission/reception control unit  30  that can transmit the received model to a numerical control apparatus  201  via a network. Furthermore, the material shape output unit  20  can output the generated material shape model to an external memory  32  via an external memory reading/writing unit  31 .  
         [0067]     Similarly, a material setup position output unit  22  generates a material setup position and outputs the generated positional information to the network transmission/reception control unit  30  that can transmit the received information to the numerical control apparatus  201  via the network. Furthermore, the material setup position output unit  22  can output the generated material setup position to the external memory  32  via the external memory reading/writing unit  31 .  
         [0068]     Similarly, a tool shape output unit  24  generates a tool shape model and outputs the generated model to the network transmission/reception control unit  30  that can transmit the received model to the numerical control apparatus  201  via the network. Furthermore, the tool shape output unit  24  can output the generated tool shape model to the external memory  32  via the external memory reading/writing unit  31 .  
         [0069]     Similarly, a tool setup position output unit  26  generates a tool setup position and outputs the generated positional information to the network transmission/reception control unit  30  that can transmit the received information to the numerical control apparatus  201  via the network. Furthermore, the tool setup position output unit  26  can output the generated tool setup position to the external memory  32  via the external memory reading/writing unit  31 .  
         [0070]     Similarly, a jig shape output unit  28  generates a jig shape model and outputs the generated model to the network transmission/reception control unit  30  that can transmit the received model to the numerical control apparatus  201  via the network. Furthermore, the jig shape output unit  28  can output the generated jig shape model to the external memory  32  via the external memory reading/writing unit  31 .  
         [0071]     In the numerical control apparatus  201 , a material shape reading unit  74  reads the material shape model via a network transmission/reception control unit  83  that is connected to the network or via an external memory reading/writing unit  84  that can read the data stored in the external memory  32 . The material shape storage memory  59  stores the retrieved material shape model.  
         [0072]     Similarly, a material setup position reading unit  76  reads the material setup position via the network transmission/reception control unit  83 , or via the external memory reading/writing unit  84  that can read the data stored in the external memory  32 . The material setup position storage memory  61  stores the retrieved material setup position.  
         [0073]     Similarly, a tool shape reading unit  78  reads the tool shape model via the network transmission/reception control unit  83 , or via the external memory reading/writing unit  84  that can read the data stored in the external memory  32 . The tool shape storage memory  63  stores the retrieved tool shape model.  
         [0074]     Similarly, a tool setup position reading unit  80  reads the tool setup position via the network transmission/reception control unit  83 , or via the external memory reading/writing unit  84  that can read the data stored in the external memory  32 . The tool setup position storage memory  65  stores the retrieved tool setup position.  
         [0075]     Similarly, a jig shape reading unit  82  reads the jig shape model via the network transmission/reception control unit  83 , or via the external memory reading/writing unit  84  that can read the data stored in the external memory  32 . The jig shape storage memory  67  stores the retrieved jig shape model.  
         [0076]     In the numerical control apparatus  201 , a material shape output unit  73  generates a material shape model and outputs the generated model to the network transmission/reception control unit  83  that can transmit the received model to the machining simulation apparatus  101  via the network. Furthermore, the material shape output unit  73  can output the generated material shape model to the external memory  32  via the external memory reading/writing unit  84 .  
         [0077]     Similarly, a material setup position output unit  75  generates a material setup position and outputs the generated positional information to the network transmission/reception control unit  83  that can transmit the received information to the machining simulation apparatus  101  via the network. Furthermore, the material setup position output unit  75  can output the generated material setup position to the external memory  32  via the external memory reading/writing unit  84 .  
         [0078]     Similarly, a tool shape output unit  77  generates a tool shape model and outputs the generated model to the network transmission/reception control unit  83  that can transmit the received model to the machining simulation apparatus  101  via the network. Furthermore, the tool shape output unit  77  can output the generated tool shape model to the external memory  32  via the external memory reading/writing unit  84 .  
         [0079]     Similarly, a tool setup position output unit  79  generates a tool setup position and outputs the generated positional information to the network transmission/reception control unit  83  that can transmit the received information to the machining simulation apparatus  101  via the network. Furthermore, the tool setup position output unit  79  can output the generated tool setup position to the external memory  32  via the external memory reading/writing unit  84 .  
         [0080]     Similarly, a jig shape output unit  81  generates a jig shape model and outputs the generated model to the network transmission/reception control unit  83  that can transmit the received model to the machining simulation apparatus  101  via the network. Furthermore, the jig shape output unit  81  can output the generated jig shape model to the external memory  32  via the external memory reading/writing unit  84 .  
         [0081]     In the machining simulation apparatus  101 , a material shape reading unit  21  reads the material shape model via the network transmission/reception control unit  30 , or via the external memory reading/writing unit  31  that can read the data stored in the external memory  32 . The material shape storage memory  5  stores the retrieved material shape model.  
         [0082]     Similarly, a material setup position reading unit  23  reads the material setup position via the network transmission/reception control unit  30 , or via the external memory reading/writing unit  31  that can read the data stored in the external memory  32 . The material setup position storage memory  7  stores the retrieved material setup position.  
         [0083]     Similarly, a tool shape reading unit  25  reads the tool shape model via the network transmission/reception control unit  30 , or via the external memory reading/writing unit  31  that can read the data stored in the external memory  32 . The tool shape storage memory  9  stores the retrieved tool shape model.  
         [0084]     Similarly, a tool setup position reading unit  27  reads the tool setup position via the network transmission/reception control unit  30 , or via the external memory reading/writing unit  31  that can read the data stored in the external memory  32 . The tool setup position storage memory  11  stores the retrieved tool setup position.  
         [0085]     Similarly, a jig shape reading unit  29  reads the jig shape model via the network transmission/reception control unit  30 , or via the external memory reading/writing unit  31  that can read the data stored in the external memory  32 . The jig shape storage memory  13  stores the retrieved jig shape model.  
         [0086]     With the above-described functional units according to the machining simulation system of the present invention, the machining simulation apparatus and the numerical control apparatus can mutually transmit and receive tool/material shape models and tool/material setup positions on a machine tool via a communication unit or a storage medium.  
         [0087]     Furthermore, in the machining simulation apparatus  101 , a simulation database collection/utilization unit  33  correlates numerical control information stored in the numerical control information storage memory  2  with machining simulation data or interference check data used in the numerical control apparatus  201  (i.e., material/tool shape models, tool/material setup positions, and jig shape model) stored in the storage memories. The simulation database collection/utilization unit  33  causes a simulation database storage memory  34  to store the related data so that it may be reused.  
         [0088]     As an exemplary storage of related and reusable data, the simulation database collection/utilization unit  33  can store a “machining simulation environment set” that includes a name of numerical control information stored in the numerical control information storage memory  2 , a name of the material shape model (i.e., a material to be processed according to the numerical control information) stored in the material shape storage memory  5 , a name of material setup position stored in the material setup position storage memory  7 , a name of the tool shape model (i.e., a tool to be used in the machining processing according to the numerical control information) stored in the tool shape storage memory  9 , a name of the tool setup position stored in the tool shape setup position storage memory  11 , and a name of the jig shape model (i.e., a jig to be used in the machining processing according to the numerical control information) stored in the jig storage memory  13 .  
         [0089]     Thus, the machining simulation apparatus  101  can reuse the numerical control information together with the material shape model, the material setup position, the tool shape model, the tool setup position, and the jig shape by referring to the machining simulation environment set.  
         [0090]     When an operator of the numerical control apparatus  201  corrects the numerical control information stored in the simulation database storage memory  34 , the corrected numerical control information is stored in the numerical control information storage memory  52  of the numerical control apparatus  201 . Although not illustrated in  FIGS. 1 and 2 , the numerical control apparatus  201  can transmit the corrected numerical control information to the numerical control information storage memory  2  of the machining simulation apparatus  101  via the external memory  32  or a network. Thus, the corrected numerical control information can be stored in the simulation database storage memory  34 .  
         [0091]     Next, exemplary processing for outputting and displaying preparatory planning information will be described with reference to  FIGS. 3 and 4 . A machining simulation apparatus  102  includes a preparatory planning information output unit  35  configured to generate preparatory planning information including a material shape model, a material setup position, a tool shape model, a tool setup position, and a jig shape model which are set for a machining simulation or an interference check.  
         [0092]     The preparatory planning information output unit  35  transmits the preparatory planning information to the network transmission/reception control unit  30  that can transmit the preparatory planning information to a numerical control apparatus  202  via a network. Furthermore, the preparatory planning information output unit  35  can output the preparatory planning information to the external memory  32  via the external memory reading/writing unit  31 . The numerical control apparatus  202  includes a preparatory planning information display unit  85  that causes the display device  71  to display the received preparatory planning information.  
         [0093]      FIG. 5  illustrates an exemplary display screen that the display device  71  can display according to the processing of the preparatory planning information display unit  85 .  
         [0094]     With the above-described functional units, the machining simulation system according to the present embodiment enables the numerical control apparatus to use the preparatory planning information (i.e., data relating to a tool, a material, or a jig) set by the machining simulation apparatus.  
         [0095]     The machining simulation system according to the present embodiment has the following effects:  
         [0096]     *1: The numerical control apparatus can use simulation data (e.g., material shape model, material setup position, tool shape model, and tool setup position) set by the machining simulation apparatus. Therefore, a setting work for the numerical control apparatus is substantially limited to correction data reflecting a machining processing environment.  
         [0000]     *2: As the setting process is simplified, the likelihood and number of setting errors can be reduced.  
         [0097]     *3: An operator of the production engineering division is not required to generate a paper document or other medium that describes or indicates preparatory planning information set by the machining simulation apparatus side, to send the setting data to an operator of the numerical control apparatus side.  
         [0098]     *4: The data corrected by the numerical control apparatus side according to a machining processing environment can be easily fed back to the machining simulation apparatus side. Because a paper document or other medium is not used, a feedback operation can be reliably performed.  
         [0099]     *5: The machining simulation apparatus side can easily collect machining data actually used in a machining operation and can establish a reusable database including the collected data. As a result, the environment of the machining simulation apparatus can be improved so as to fit within the environment of the worksite.
A numerical control apparatus can perform a machining simulation or an interference check that reflects worksite information. However, a machining simulation apparatus cannot use worksite information in a machining simulation or an interference check. Thus, simulation conditions of the machining simulation apparatus are different from those of the numerical control apparatus. To solve this problem, a machining simulation apparatus and a numerical control apparatus according to the present invention can communicate with each other via a communication unit or a storage medium so as to mutually transmit and receive data. The machining simulation apparatus includes a network transmission/reception control unit or an external memory reading/writing unit. Similarly, the numerical control apparatus includes a network transmission/reception control unit or an external memory reading/writing unit.