Abstract:
A workpiece-attachment-information reporting device ( 10 ) is equipped with: a range-setting unit ( 13 ) for setting a movable range in a prescribed feed-shaft direction of a work machine; a position-orientation-setting unit ( 14 ) for setting the attachment position or orientation of a workpiece; a route-setting unit ( 12 ) for setting a tool route on the basis of the attachment position or orientation of a workpiece; a range calculation unit ( 15 ) for calculating the operational range in the prescribed feed-shaft direction of a work machine, given that the tool has moved relative to the workpiece along the tool route; a target-position-orientation calculation unit ( 16 ) for obtaining the target attachment position or orientation of the workpiece with the calculated operational range being within the movable range; and a reporting unit ( 6 ) for reporting the target attachment position or orientation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. National Phase patent application of International Patent Application No. PCT/JP2012/078056, filed on Oct. 30, 2012, which is hereby incorporated by reference in the present disclosure in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a workpiece-attachment-information reporting device which reports attachment information of a workpiece to deal with stroke-over of a machine tool. 
       BACKGROUND OF THE INVENTION 
       [0003]    When controlling a machine tool by an NC device based on a processing program so as to process a workpiece which is fastened to a table, sometimes a situation ends up arising where the position instructed to the linear feed axis or rotational feed axis of the machine tool ends up outside of the actual movable range of the feed axis (called “stroke-over”). To deal with such stroke-over, in the past, there has been known a system which, when a table rotation command which would result in stroke-over at the linear feed axis is output during path control of the front end point of the tool, maintains the distance between the front end point of the tool and the center of the table rotation constant from the start of table rotation to the end of table rotation while making the tool retract to thereby try to avoid the stroke-over (for example, see PLT 1). 
         [0004]    However, with a system such as described in PLT 1 where the tool is made to retract to try to avoid stroke-over, it is difficult to smoothly process the entire area of the workpiece based on a processing program. 
         [0005]    PLT 1: International Publication No. 2011/111088A 
       SUMMARY OF THE INVENTION 
       [0006]    A workpiece-attachment-information reporting device according to one aspect of the present invention comprises a range setting unit which sets a movable range of a machine tool in a predetermined feed axis direction, a position/posture setting unit which sets a mounting position or posture of the workpiece mounted on a workpiece mounting surface of the machine tool, a path setting unit which sets a tool path based on the mounting position or posture of the workpiece set at the position/posture setting unit, a range calculating unit which calculates an operating range of the machine tool in the predetermined feed axis direction when assuming that the tool moves relative to the workpiece along the tool path set at the path setting unit, a target position/posture computing unit which finds the target mounting position or posture of the workpiece by which the operating range calculated by the range calculating unit becomes within the movable range set at the movable range setting unit, and a reporting part which reports the target mounting position or posture found by the target position/posture computing unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a view which shows one example of a machine tool to which a workpiece-attachment-information reporting device according to an embodiment of the present invention is applied. 
           [0008]      FIG. 2  is a view which shows another example of a machine tool to which a workpiece-attachment-information reporting device according to an embodiment of the present invention is applied. 
           [0009]      FIG. 3A  is a view which explains problem points due to stroke-over in the A-axial direction. 
           [0010]      FIG. 3B  is a view which explains problem points due to stroke-over in the A-axial direction. 
           [0011]      FIG. 4  is a view which shows the relationship between a movable range of a machine tool in the A-axial direction and an operating range in the A-axial direction which is instructed by the processing program. 
           [0012]      FIG. 5  is a view which shows an example where a workpiece is mounted to a workpiece mounting surface rotated relative to it by exactly a predetermined angle α in the A-axial direction. 
           [0013]      FIG. 6  is a block diagram which shows the schematic configuration of a workpiece-attachment-information reporting device according to an embodiment of the present invention. 
           [0014]      FIG. 7  is a view which explains parameters which define a workpiece mounting posture. 
           [0015]      FIG. 8  is a view which shows one example of a display image which is displayed at a display unit of  FIG. 6 . 
           [0016]      FIG. 9  is a flow chart which shows one example of processing which is performed by a control unit of  FIG. 6 . 
           [0017]      FIG. 10A  is a view which shows a modification of  FIG. 8 . 
           [0018]      FIG. 10B  is a view which shows a modification of  FIG. 8 . 
           [0019]      FIG. 10C  is a view which shows a modification of  FIG. 8 . 
           [0020]      FIG. 11  is a view which shows a modification of  FIG. 9 . 
           [0021]      FIG. 12  is a view which shows a modification of  FIG. 6 . 
           [0022]      FIG. 13  is a view which shows one example of a display image which shows a stroke-over occurrence position. 
           [0023]      FIG. 14  is a view which shows a modification of  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    Below, referring to  FIG. 1  to  FIG. 14 , an embodiment of a workpiece-attachment-information reporting device according to the present invention will be explained.  FIG. 1  is a view which shows one example of a machine tool MC to which a workpiece-attachment-information reporting device according to an embodiment of the present invention is applied. 
         [0025]    The machine tool  100  which is shown in  FIG. 1  is a five-axis horizontal machining center in which a tool T extends along a horizontal direction axial line L 0 . In  FIG. 1 , a horizontal direction parallel to the axial line L 0  is defined as the “Z-axial direction” (front-back direction), a horizontal direction vertical to the Z-axial direction is defined as the “X-axial direction” (left-right direction), and a vertical direction is defined as the “Y-axial direction” (up-down direction). 
         [0026]    As shown in  FIG. 1 , the machine tool  100  has a bed  101  which is fastened to the floor, a column  102  which is provided standing on the top surface of the bed  101  to be able to move in the horizontal direction (Z-axial direction), a table  103  which is provided in front of the column  102  to be able to move on the top surface of the bed  101  in the horizontal direction (X-axial direction), and a spindle table  104  which is provided on the front surface of the column  102  to be able to move in the up-down direction (Y-axial direction). On the top surface of the table  103 , a right angle plate  105  is attached. At the back surface of the right angle plate  105 , that is, a workpiece mounting surface W 0 , a workpiece W is fastened. 
         [0027]    At the spindle table  104 , a swivel base  106  which can rotate about a rotational feed axis (C-axis) direction centered about the Z-axis is attached. The swivel base  106  has a pair of arm parts which are arranged separated from each other in the left-right direction. Between the left-right pair of arm parts, a spindle head  107  is supported to be able to rotate about a rotational feed axis (A-axis) vertical to the C-axis. The spindle head  107  supports the spindle  108  to be able to rotate. At the front end part of the spindle  108 , the tool T is attached. The tool T is for example a ball end mill with a semispherical front end part. 
         [0028]    The table  103 , spindle table  104 , and column  102  move by respective linear feed mechanisms in the X-axial direction, Y-axial direction, and Z-axial direction. The linear feed mechanisms are, for example, comprised of ball screws, servo motors which drive rotation of the ball screws (X-axis use servo motor, Y-axis use servo motor, and Z-axis use servo motor), etc. The spindle head  107  and swivel base  106  respectively rotate about the A-axial direction and C-axial direction by drive operation of the servo motors (A-axis use servo motor and C-axis use servo motor). Due to this, the workpiece W moves relative to the tool T and processes the workpiece W with the tool T in a desired processing posture. 
         [0029]    The drive operations of the X-axis servo motor, Y-axis servo motor, Z-axis servo motor, A-axis servo motor, and C-axis servo motor and the drive operation of the spindle drive spindle motor are controlled by an NC (numerical control) device  2 . That is, NC device  2  outputs control signals to these servo motors and spindle motor in accordance with a processing program which is output from the CAM (computer aided manufacturing) device so as to control the operation of the machine tool  100 . 
         [0030]      FIG. 2  is a view which shows one example of another machine tool MC to which a workpiece-attachment-information reporting device according to an embodiment of the present invention is applied. The machine tool  200  which is shown in  FIG. 2  is a five-axis vertical machining center where the tool T extends along the vertical direction axial line L 0 . In  FIG. 2 , the vertical direction parallel to the axial line L 0  is defined as the “Z-axial direction” (up-down direction), the horizontal direction vertical to the Z-axial direction is defined as the “X-axial direction” (left-right direction), and the horizontal direction vertical to the X-axial direction is defined as the “Y-axial direction” (front-back direction). 
         [0031]    As shown in  FIG. 2 , the machine tool  200  is provided with a bed  201 , a column  202  which is provided standing on the bed  201 , a spindle table  204  which can move in the X-axial direction along a guide rail  203  which is provided on the column  202 , a spindle head  206  which can move in the Z-axial direction along a guide rail  205  which is provided on the spindle table  204 , and a spindle  207  which is supported at the spindle head  206  to be able to rotate and has a tool T attached to it. The bed  201  is provided with a saddle  209  which can move along the guide rail  208  in the Y-axial direction. On the saddle  209 , a trunnion  210  which has a pair of side walls which are separated from each other in the X-axial direction is fastened. Between the pair of side walls, a table swivel base  211  is provided to be able to rotate about a rotational feed axis (A-axis) centered on the X-axis. On the table swivel base  211 , a table  212  is attached which can rotate about a rotational feed axis (C-axis) centered on the Z-axis. The workpiece W is fastened on the workpiece mounting surface W 0  of the table  212 . 
         [0032]    The spindle table  204 , saddle  209 , and spindle head  206  move in the X-axial direction, Y-axial direction, and Z-axial direction by respective linear feed mechanisms which have ball screws and servo motors which drive rotation of the ball screws. The table swivel base  211  and table  212  are driven by respective servo motors to rotate in the A-axial direction and C-axial direction. The drive operations of these servo motors and the drive operation of the spindle motor for driving the spindle are controlled by the NC device  2  in accordance with the processing program which is output from the CAM device  1 . 
         [0033]    The above machine tools MC have movable ranges distinctive to the machine in the X-axial direction, Y-axial direction, Z-axial direction, and A-axial direction feed axis directions. If a movement command value of the machine tool MC by the processing program exceeds such a movable range (this being called “stroke-over”), the following such problem occurs. Note that, the C-axis can rotate 360°, so stroke-over does not occur.  FIG. 3A  and  FIG. 3B  are views which explain the problem points due to stroke-over in the A-axial direction. 
         [0034]    The solid line of  FIG. 3A  shows the state where the workpiece W (workpiece mounting surface W 0 ) is made to rotate to the maximum relative to the tool T in the A-axial direction which is shown by the arrow mark A 1 . At this time, the angle θa which is formed by the reference line L 1  vertical to the axial line L 0  of the tool T and the workpiece mounting surface W 0  is θ 1  (for example, 30°), while angle θa is assumed to be able to be changed to θ 2  (for example, −120°) to the opposite side of the A 1  direction (arrow A 2  direction). In this case, the movable range of the machine tool in the A-axial direction is θ 1  to θ 2 . 
         [0035]    Here, assume processing giving an angle θa which is formed between the reference line L 1  and the workpiece mounting surface W 0  of θa 1  (for example, 45°), that is, the processing posture of the tool T which is shown by the broken line in  FIG. 3A , is instructed. At this time, θa 1  exceeds the movable range θ 1  to θ 2  of the machine tool in the A-axial direction (stroke-over), so the workpiece mounting surface W 0  cannot be made to rotate relatively in the arrow mark A 1  direction to make the angle θa which is formed with the reference line L 1  θa 1 . Therefore, the NC device  2 , for example, as shown in  FIG. 3B , outputs a processing command so as to make the workpiece mounting surface W 0  rotate relatively by exactly 180° in the C-axial direction centered about the axial line L 0  and so that the angle θa which is formed between the reference line L 1  and the workpiece mounting surface W 0  becomes −θa 1 . 
         [0036]    In this case, the workpiece W rotates relatively in the C-axial direction and A-axial direction with the tool T remaining in contact with the workpiece surface Wa, so the tool T is liable to cut into the workpiece surface Wa. As a result, processing marks are formed at the workpiece surface Wa and formation of a good processed surface becomes difficult. Such stroke-over in the A-axial direction can sometimes be eliminated by changing the mounting posture of the workpiece W as shown below. 
         [0037]      FIG. 4  is a view which shows the relationship between a movable range of the machine tool MC in the A-axial direction and an operating range in the A-axial direction which is instructed by the processing program. In the figure, L 1  (θ 2 ≦θa≦θ 1 ) is the movable range of the machine tool MC, while L 2  (θmin≦θa≦θmax) is the operating range which is instructed by the processing program. As shown in  FIG. 4 , L 2  exceeds L 1  in the range of θ 1 &lt;θa≦θmax. In this range, stroke-over occurs. If making the workpiece W rotate relatively from this state from the workpiece mounting surface W 0  in the A-axial direction ( FIG. 3A , arrow mark A 1  direction) by exactly a predetermined angle Δθ 1  (=θmax−θ 1 ), the operating range L 2  becomes L 21 . If making it rotate relatively by exactly a predetermined angle Δθ 2  (=θmin−θ 2 ), the operating range L 2  becomes L 22 . Therefore, by making the workpiece W rotate relatively in the A-axial direction in the range of Δθ 1  to Δθ 2 , it is possible to make the operating range L 2  of the processing program shift to the inside in the movable range L 1 . 
         [0038]    It is possible to change the mounting posture of the workpiece W in the A-axial direction using a fixture.  FIG. 5  is a view which shows an example of the workpiece W being made to rotate relative to the workpiece mounting surface W 0  in the A-axial direction ( FIG. 3 , arrow mark A 1  direction) by exactly a predetermined angle α and mounted. Between the workpiece mounting surface W 0  and the workpiece W, a fixture  4  which has a slanted surface of a predetermined angle α is interposed. The angle α, for example, corresponds to Δθ 1  of  FIG. 4 . Due to this, the operating range L 2  of the processing program shifts to L 21  of  FIG. 4  and stroke-over in the A-axial direction can be eliminated. 
         [0039]    When using a fixture  4  in this way to eliminate stroke-over in the A-axial direction, it is preferable to report to the user how to change the mounting posture of the workpiece W, that is, the attachment information of the workpiece W. Therefore, in this embodiment, the mounting posture of the workpiece W which eliminates stroke-over (called “target mounting posture”) is reported to the user, so the workpiece-attachment-information reporting device is configured in the following way. 
         [0040]      FIG. 6  is a block diagram which shows the schematic configuration of a workpiece-attachment-information reporting device  10  according to the present embodiment and shows an example where the workpiece-attachment-information reporting device  10  is configured by the CAM device  1 . As shown in  FIG. 6 , the workpiece-attachment-information reporting device  10  has an input unit  5  and a display unit  6  centered about the control unit  11 . From the input unit  5 , shape data of the workpiece W, shaft configuration data configuring the feed axes of the machine tool MC, the movable range data of the different feed axes and other various types of information required for processing at the control unit  11  are input. 
         [0041]    The control unit  11  is configured by a processing device which has a CPU, ROM, RAM, and other peripheral circuits etc. and functionally has a path setting unit  12 , movable range setting unit  13 , posture setting unit  14 , range calculating unit  15 , target posture computing unit  16 , and display control unit  17 . 
         [0042]    The path setting unit  12  uses the shape data of the workpiece W which is input through the input unit  5  (for example, CAD data) as the basis to generate a tool path for processing the workpiece W. The tool path can be obtained by successively connecting the processing points on the workpiece surface. The tool path data includes position data of processing points expressed by the position vector (x, y, z) of the front end part of the tool and the posture vector (i, j, k) of the tool T. The path setting unit  12 , if changing the mounting posture (slant) of the workpiece W to the workpiece mounting surface W 0 , changes the posture vector of the tool T accordingly and generates a new tool path. Note that, the tool path before changing the workpiece mounting posture will be referred to here as a “reference tool path”. 
         [0043]    The movable range setting unit  13  sets the movable range of the machine tool MC in the A-axial direction ( FIG. 4 , L 1 ). 
         [0044]    The posture setting unit  14  sets the mounting posture of the workpiece W using the workpiece mounting surface W 0  as a reference. In the present embodiment, as shown in  FIG. 7 , using the workpiece mounting surface W 0  as a reference, three orthogonal axes (L, M, and N) are defined. The rotational directions centered about the axes L, M, and N are respectively defined as the α (roll angle), β (pitch angle), and γ (yaw angle). The workpiece mounting posture is expressed by these α, β, and γ. The roll angle α of the workpiece W can be changed in the range from the minimum value α 1  (for example, −180°) to the maximum value α 2  (for example, 180°), the pitch angle β can be changed in the range from the minimum value β 1  (for example, −90°) to the maximum value β 2  (for example, 90°), and the yaw angle γ can be changed in the range from the minimum value γ 1  (for example, −180°) to the maximum value γ 2  (for example, 180°). 
         [0045]    The workpiece mounting posture where the roll angle α, pitch angle β, and yaw angle γ are respectively 0° will be referred to here as the “reference posture”. The reference tool path corresponds to the tool path which is set for the workpiece W in the reference posture. The posture setting unit  14  sets not only the mounting posture of the workpiece W, but also the mounting position of the workpiece W on the workpiece mounting surface W 0 . For example, on the workpiece mounting surface W 0 , a workpiece origin coordinate serving as the reference for the reference posture, that is, the mounting position of the workpiece W, is set. 
         [0046]    The range calculating unit  15  calculates the operating range of the machine tool MC in the A-axial direction ( FIG. 4 , L 2 ) when assuming that the tool T has moved relatively along the tool path set at the path setting unit  12 . If changing the workpiece mounting posture, the operating range L 2  also changes. That is, as shown in  FIG. 4 , the operating range L 2  shifts. This operating range L 2  is calculated regardless of the actual movable range L 1  of the machine tool MC. 
         [0047]    The target posture computing unit  16  finds the target mounting posture of the workpiece W so that the operating range L 2  which has been calculated by the range calculating unit  15  becomes within the movable range L 1  which has been set at the movable range setting unit  15 . Specifically, the posture setting unit  14  makes the roll angle α, pitch angle β, and yaw angle γ respectively change from the minimum values α 1 , β 1 , and γ 1  to the maximum values α 2 , β 2 , and γ 2  by a respective predetermined angle increment Δα, Δβ, or Δγ so as to change the workpiece mounting posture, and the range calculating unit  15  calculates the operating ranges L 2  corresponding to these workpiece mounting postures. Further, the target posture computing unit  16  judges if the operating ranges L 2  are within the movable ranges L 1  and converts the roll angle α, pitch angle β, and yaw angle γ which are within the movable ranges to the A-axis and C-axis of the machine tool MC. Due to this, the range of the A-axis for making the operating range L 2  within the movable range L 1 , that is, the target mounting posture of the workpiece W, is found. 
         [0048]    The display control unit  17  displays the target mounting posture of the workpiece W which has been found at the target posture computing unit  16  on the display unit  6 .  FIG. 8  is a view which shows one example of a display screen  61  which is displayed at the display unit  6 . The display screen  61  has a display part  62  which displays the target mounting posture of the workpiece W by numerical values and a display part  63  which displays the target mounting posture of the workpiece W by graphics. In  FIG. 8 , the range of angle of the A-axis which is displayed at the display part  62  is −80° to −15°. The display part  63  shows a workpiece image  631  which shows the workpiece W at the reference posture by a solid line and shows a workpiece image  632  which shows the workpiece W at the target mounting posture which is closest to the reference posture (in this example, −15°) by a broken line. Note that, to clearly differentiate the workpiece image  631  and the workpiece image  632 , the solid line and broken line may also be displayed by different colors. 
         [0049]    Due to this, the user can easily obtain a grasp of the mounting posture of the workpiece W in the A-axial direction for avoiding stroke-over. In this case, the mounting posture of the workpiece W which is closest to the reference posture is displayed by the broken line, so the slant of the workpiece W on the workpiece mounting surface through the fixture  4  can be made the minimum. 
         [0050]    The processing which is performed by the control unit  11  will be explained more specifically.  FIG. 9  is a flow chart which shows one example of the processing which is performed by the control unit  11 . The processing which is shown in this flow chart is, for example, started when the start of calculation of the target mounting posture of the workpiece W is instructed by operation of the input unit  5 . 
         [0051]    At step S 1 , the tool path data which has been set at the path setting unit  12  is read and the axis configuration data, movable range data, etc. of the machine tool which were set in advance through the input unit  5  are read. At step S 2 , for the pitch angle α, roll angle β, and yaw angle γ, the minimum values α 1 , β 1 , and γ 1  are entered as initial values. At step S 3 , the posture vector (i, j, k) in the tool path data are converted using α, β, and γ by the following formula (I) to the posture vector (i′, j′, k′). That is, along with a change in the mounting posture of the workpiece W, the posture vector of the tool T is converted and new tool path data is generated. 
         [0000]    
       
         
           
             
               
                 
                   
                     [ 
                     
                       
                         
                           
                             i 
                             ′ 
                           
                         
                       
                       
                         
                           
                             j 
                             ′ 
                           
                         
                       
                       
                         
                           
                             k 
                             ′ 
                           
                         
                       
                     
                     ] 
                   
                   = 
                   
                     
                       
                         
                           [ 
                           
                             
                               
                                 
                                   cos 
                                    
                                   
                                       
                                   
                                    
                                   γ 
                                 
                               
                               
                                 0 
                               
                               
                                 
                                   sin 
                                    
                                   
                                       
                                   
                                    
                                   γ 
                                 
                               
                             
                             
                               
                                 0 
                               
                               
                                 1 
                               
                               
                                 0 
                               
                             
                             
                               
                                 
                                   
                                     - 
                                     sin 
                                   
                                    
                                   
                                       
                                   
                                    
                                   γ 
                                 
                               
                               
                                 0 
                               
                               
                                 
                                   cos 
                                    
                                   
                                       
                                   
                                    
                                   γ 
                                 
                               
                             
                           
                           ] 
                         
                          
                         
                           [ 
                           
                             
                               
                                 1 
                               
                               
                                 0 
                               
                               
                                 0 
                               
                             
                             
                               
                                 0 
                               
                               
                                 
                                   cos 
                                    
                                   
                                       
                                   
                                    
                                   β 
                                 
                               
                               
                                 
                                   
                                     - 
                                     sin 
                                   
                                    
                                   
                                       
                                   
                                    
                                   β 
                                 
                               
                             
                             
                               
                                 0 
                               
                               
                                 
                                   sin 
                                    
                                   
                                       
                                   
                                    
                                   β 
                                 
                               
                               
                                 
                                   cos 
                                    
                                   
                                       
                                   
                                    
                                   β 
                                 
                               
                             
                           
                           ] 
                         
                       
                        
                       
                         [ 
                         
                           
                             
                               
                                 cos 
                                  
                                 
                                     
                                 
                                  
                                 α 
                               
                             
                             
                               
                                 
                                   - 
                                   sin 
                                 
                                  
                                 
                                     
                                 
                                  
                                 α 
                               
                             
                             
                               0 
                             
                           
                           
                             
                               
                                 sin 
                                  
                                 
                                     
                                 
                                  
                                 α 
                               
                             
                             
                               
                                 cos 
                                  
                                 
                                     
                                 
                                  
                                 α 
                               
                             
                             
                               0 
                             
                           
                           
                             
                               0 
                             
                             
                               0 
                             
                             
                               1 
                             
                           
                         
                         ] 
                       
                     
                      
                     
                       [ 
                       
                         
                           
                             i 
                           
                         
                         
                           
                             j 
                           
                         
                         
                           
                             k 
                           
                         
                       
                       ] 
                     
                   
                 
               
               
                 
                   [ 
                   I 
                   ] 
                 
               
             
           
         
       
     
         [0052]    At step S 4 , the converted tool path data is read for one further row. In each row of the tool path data, the position data of a different processing point (x, y, z, i′, j′, k′) is written. By reading one further row of the tool path data, the position data of the next processing point is read. At step S 5 , the posture vector (i′, j′, k′) of the read tool path data is converted to the rotation axis command θa, θc of the A-axis and C-axis of the machine tool MC. 
         [0053]    At step S 6 , the operating range L 2  of the A-axis (minimum value θmin and maximum value θmax of  FIG. 4 ) are calculated. At step S 7 , it is judged if the tool path data has been read up to the end. If yes at step S 7 , the routine proceeds to step S 8 , while if no, the routine returns to step S 4  where similar processing is repeated. 
         [0054]    If the processing of step S 6  is first performed, the value θa of the A-axis which has been found in the immediately preceding step S 5  becomes the minimum value θmin and the maximum value θmax. After that, each time the tool path data is read at step S 4 , the value θa of the A-axis is calculated at step S 5 . At step S 6 , the relative size of this θa and the already set minimum value θmin and maximum value θmax is judged. Further, when, at step S 6 , θa is smaller than θmin, θa is made the minimum value θmin to update the minimum value θmin, while when θa is larger than θmax, θa is made the maximum value θmax to update the maximum value θmax. This processing is repeated over the entire tool path data to finally calculate the operating range L 2  of the A-axis. 
         [0055]    At step S 8 , it is judged if the operating range L 2  of the A-axis which has been calculated at step S 7  is within the movable range L 1  of the A-axis of the machine tool MC, that is, if stroke-over has occurred. If yes at step S 8 , the routine proceeds to step S 9 , while if no, the routine bypasses step S 9  and proceeds to step S 10 . At step S 9 , the value θa of the A-axis which corresponds to the workpiece posture for calculating the operating range L 2 , that is, the value θa corresponding to the roll angle α, pitch angle β, and yaw angle γ, is calculated. This θa is stored as the target mounting posture in the memory. Note that, at this time, the angle θc of the C-axis corresponding to α, β, and γ is simultaneously calculated, but there is no need to store θc for preventing stroke-over for the C-axis. 
         [0056]    At step S 10 , it is judged if the roll angle α, pitch angle β, and yaw angle γ are the maximum values α 2 , β 2 , and γ 2 . If no at step S 10 , the routine proceeds to step S 11 , the predetermined angle increment Δα, Δβ, or Δγ is added to the roll angle α, pitch angle β, or yaw angle γ, and the workpiece mounting posture is changed. Next, the routine returns to step S 3  where similar processing is repeated. The workpiece mounting posture is gradually changed each time the processing of step S 11  is repeated. At step S 11 , for example, first, the angle increment Δα is added to the roll angle α, when the roll angle α becomes the maximum value α 2 , next, the angle increment Δβ is added to the pitch angle β to return the roll angle α to the minimum value α 1  and processing for adding the angle increment Δα to the roll angle α is returned to. Further, when the pitch angle β becomes the maximum value β 2 , next, the angle increment Δγ is added to the yaw angle γ to return the pitch angle β to the minimum value β 1  and the roll angle α to the minimum value α 1  and processing to add the angle increment Δα to the roll angle α is returned to. By repeating this, the workpiece mounting posture is gradually changed until the roll angle α, pitch angle β, and yaw angle γ respectively become the maximum values α 2 , β 2 , and γ 2 . By the processing of step S 3  to step S 11  being repeated, at step S 9 , a plurality of values θa of the A-axis which show the target mounting posture are stored. 
         [0057]    If yes at step S 10 , the routine proceeds to step S 12  where the display unit  6  is made to display a target mounting posture of the workpiece W. That is, as shown in the display part  62  of  FIG. 8 , the plurality of values θa of the A-axis which have been stored at step S 9  is displayed as a range of angles. Furthermore, as shown by the display part  63  of  FIG. 8 , the workpiece image  631  which shows the reference posture of the workpiece W is displayed by a solid line, while the workpiece image  632  which shows the target mounting posture by which the change in posture becomes the minimum is displayed by a broken line. Note that, when there is no value θa of the A-axis which shows the target mounting posture, a message to the effect that there is no workpiece mounting posture which can eliminate stroke-over etc. is displayed at the display unit  6 . Due to the above, processing at the control unit  11  is ended. 
         [0058]    According to the present embodiment, the following such operations and effects can be exhibited. 
         [0059]    (1) The workpiece-attachment-information reporting device  10  according to the present embodiment (control unit  11 ) is provided with a movable range setting unit  13  which sets a movable range L 1  of a machine tool MC in the A-axial direction, a posture setting unit  14  which sets a mounting position (workpiece origin coordinate position) and posture of a workpiece W which is mounted on a workpiece mounting surface W 0  of the machine tool MC, a path setting unit  12  which sets a tool path based on the set workpiece mounting posture, a range calculating unit  15  which calculates an operating range L 2  of the machine tool MC in an A-axial direction when assuming a tool T moves relatively to the workpiece W along the set tool path, a target posture computing unit  16  which finds a target mounting posture of the workpiece W whereby the calculated operating range L 2  becomes within the movable range L 1 , and a display control unit  17  which displays the found target mounting posture at the display unit  6 . Due to this, the user can obtain a grasp of the workpiece mounting posture which avoids stroke-over and can smoothly process the entire area of a workpiece while avoiding stroke-over when processing the workpiece. 
         [0060]    (2) The target mounting posture of the workpiece W is displayed at the display unit  6 , so the user can easily grasp how to change the workpiece mounting posture. 
         [0061]    (3) The posture setting unit  14  changes the roll angle α, pitch angle β, and yaw angle γ by the respective predetermined angle increments Δα, Δβ, and Δγ to set a plurality of mounting postures of the workpiece W (step S 11 ), the path setting unit  12  sets tool paths corresponding to the thus set plurality of mounting postures (step S 3 ), the range calculating unit  15  calculates the operating ranges L 2  in the A-axial direction corresponding to the thus set tool paths (step S 6 ), and the target posture computing unit  16  judges if the thus calculated operating ranges L 2  are within the movable range L 1  which has been set at the movable range setting unit  13  to thereby find the target mounting posture of the workpiece W (step S 8 , step S 9 ). Due to this, it is possible to obtain a plurality of target mounting postures and possible to give a range of the angle θa of the A-axis corresponding to the target mounting posture for display on the display unit  6 . Therefore, the user need only determine the workpiece mounting posture within the displayed range. The extent of selection of the workpiece mounting posture is broad, so the user friendliness is good. 
         [0062]    (4) The workpiece-attachment-information reporting device  10  of the present embodiment is comprised of the CAM device  1  which generates a tool path (reference tool path), so it is possible to generate a tool path, then immediately find the target mounting posture of the workpiece W which avoids stroke-over. 
         [0063]    In the above embodiment, the range of angle of the A-axis corresponding to the target mounting posture of the workpiece W was displayed, but considering the case of avoiding stroke-over by adjusting the angles of the two rotational axes of the A-axis and C-axis, it is also possible to also display the range of angle of the C-axis. In this case, for example, it may be assumed that the A-axis is set to a value in the range of angle displayed on the display part  62  ( FIG. 8 ) and similar processing may be performed as explained above for the C-axis so as to calculate the range of angle of the C-axis and display it at the display unit  6 .  FIG. 10A  to  FIG. 10C  are views which shown one example of the display screen  61  in this case. 
         [0064]      FIG. 10A  shows an example of setting the A-axis to −15°. In the figure, the display part  64  displays the ranges of angles of the A-axis and C-axis by a scale. Here, the range of angle of the A-axis which avoids stroke-over is −80° to −15°, while the range of angle of the C-axis when setting the A-axis to −15° becomes −120° to 120°. The display part  64  is provided with setting bars  641 ,  642  which can be operated by the user. By operation of the setting bars  641 ,  642 , the set angles of the A-axis and C-axis can be changed. 
         [0065]    The display part  65  displays the angles of the A-axis and C-axis (A-axis −15°, C-axis 0°) giving the smallest change in posture from the reference posture of the workpiece W. The display part  63  displays the workpiece images  631 ,  632  corresponding to the angles of the A-axis and C-axis by the solid line and broken line. The instructed values of the setting bars  641 ,  642  also change in accordance with the angles of the A-axis and C-axis which are displayed at the display part  65 . 
         [0066]      FIG. 10B  shows an example where the setting bar  641  is operated from the state of  FIG. 10A  to change the set angle θa of the A-axis to −65°. At this time, the range of angle of the C-axis which is displayed at the display part  64  is changed to −80° to 80°. From among this, the angle (0°) of the C-axis which makes the change in posture of the workpiece W minimum is selected and is displayed together with the set angle (−65°) of the A-axis at the display part  65 . The posture of the workpiece image  632  which is shown at the display part  63  also changes in accordance with this. 
         [0067]      FIG. 10C  shows an example of operating the setting bar  642  from the state of  FIG. 10B  to change the set angle θc of the C-axis to 30°. At this time, the angle θc of the C-axis which is displayed at the display part  65  changes. The display of the workpiece image  632  of the display part  63  also changes in accordance with the change of angle of the C-axis. 
         [0068]    In the above embodiment, the parameters which make the workpiece mounting posture change, that is, the pitch angle α, roll angle β, and yaw angle γ, are made to change from the respective minimum values α 1 , β 1 , and γ 1  to the maximum values α 2 , β 2 , and γ 2  to find the range of angle of the A-axis corresponding to the target mounting posture of the workpiece W, but the processing at the control unit  11  is not limited to this. For example, it is also possible to end the processing when the angle θa of the A-axis corresponding to the target mounting posture of the workpiece W is found and to display that angle θa.  FIG. 11  is a flow chart which shows on example of the processing which is performed by the control unit  11  in this case. Note that, parts which perform processing the same as in  FIG. 9  are assigned the same reference notations. 
         [0069]    As shown in  FIG. 11 , at step S 1 , data is read, then, at step S 21 , initial values are entered for the roll angle α, pitch angle β, and yaw angle γ. The initial values are, for example, 0. Note that, the minimum values α 1 , β 1 , and γ 1  or the maximum values α 2 , β 2 , and γ 2  of α, β, and γ may also be made the initial values. After that, in the same way as  FIG. 9 , the processing of step S 3  to step S 8  is performed. At step S 8 , if it is judged that the operating range L 2  is within the movable range L 1 , the routine proceeds to step S 22  where the angle θa of the A-axis corresponding to α, β, and γ is calculated. This is output as the target mounting posture to the display unit  6 , then the processing is ended. On the other hand, if step S 8  is no, at step S 10 , it is judged if α, β, and γ are the maximum values α 2 , β 2 , and γ 2 . If yes, the routine proceeds to step S 23 , while if no, the routine proceeds to step S 11 . At step S 23 , it is judged if α, β, and γ are the minimum values α 1 , β 1 , and γ 1 . If no, the routine proceeds to step S 11 , while if yes, the processing is ended. In this case, for example, a message etc. to the effect of there not being a workpiece mounting posture which enables elimination of stroke-over is displayed at the display unit  6  and the processing is ended. 
         [0070]    By ending the processing at the control unit at the state where the angle θa of the A-axis corresponding to the target mounting posture of the workpiece W is found in this way, it is possible to shorten the calculation time and possible to immediately report the target mounting posture to the user. 
         [0071]    It is also possible to assume that the workpiece has been mounted at the reference posture and detect the position of occurrence of stroke-over.  FIG. 12  is a block diagram which shows the schematic configuration of the workpiece-attachment-information reporting device  10  in this case. As shown in  FIG. 12 , the control unit  11  has a stroke-over detecting unit  18  in addition to what is shown in functional configuration in  FIG. 6 . The stroke-over detecting unit  18  converts the tool path data (i, j, k) to the rotation axis command θa, θc of the A-axis and C-axis of the machine tool MC and calculates the position of the processing point where the rotation axis command θa exceed the movable range L 1  of the A-axis. The thus calculated position of the processing point is the position of occurrence of stroke-over. This stroke-over occurrence position can be displayed at the display unit  6 . 
         [0072]      FIG. 13  is a view which shows one example of a display screen which displays a stroke-over occurrence position. The display part  66  displays a workpiece image  661  which shows the processed surface of the workpiece W and a tool path image  662  which shows a tool path along the processed surface. On the tool path image  662 , marks  663  which show stroke-over occurrence positions (in the figure, white circles) are displayed. Due to this, the user can confirm the position at which stroke-over occurs. Note that, the processing by the stroke-over detecting unit  18  is performed before starting the processing of  FIG. 9 . The processing of  FIG. 9  need only be applied when stroke-over is detected. 
         [0073]    In the above embodiment, the CAM device  1  is used to form the workpiece-attachment-information reporting device  1 , but something other than the CAM device  1  may also be used to form the workpiece-attachment-information reporting device  1 .  FIG. 14  shows an example where an NC device  2  is used to form the workpiece-attachment-information reporting device  1 . The path setting unit  12  of  FIG. 14  reads a tool path (reference tool path) which is contained in the processing program from the CAM device  1  and converts this reference tool path to a tool path which corresponds to the mounting posture along with a change of the workpiece mounting posture. 
         [0074]    Note that, in the above embodiment, the workpiece-attachment-information reporting device is applied to a five-axis machining center with rotational feed axes of the A-axis and C-axis, but may also be applied to another machine tool MC including a rotational feed axis of the B-axis. For example, when the rotational feed axes are the A-axis and B-axis, a target mounting posture of the workpiece W which simultaneously avoids stroke-overs of the A-axis and B-axis may be found and displayed at the display unit  6 . A target mounting position of the workpiece W which avoids stroke-over of not only the rotational feed axes, but also linear feed axes may be found and displayed at the display unit  6 . The range setting unit  13  may set the movable range L 1  of any feed axis of the X-axis, Y-axis, Z-axis, A-axis, B-axis, and C-axis. Further, the present invention can be similarly applied even to a machine tool MC which does not have a rotational feed axis (for example, three-axis machining center). 
         [0075]    When applying the present invention to a linear feed axis, the mounting position of the workpiece which is mounted to the workpiece mounting surface W 0  of the machine tool MC is set, this mounting position is used as the basis for the path setting unit  12  to set the tool path, and the operating range L 2  of the machine tool MC in the linear feed axis direction when assuming that the tool T moves relative to the workpiece W along this tool path is calculated. Furthermore, the target mounting position of the workpiece enabling the calculated operating range L 2  to become within the movable range L 1  may be found and this target mounting position displayed at the display unit  6 . In this case, a position/posture setting unit (for example, posture setting unit  14 ) may set a mounting position of the workpiece W, a target position/posture computing unit (for example, target posture computing unit  16 ) may find the target mounting position of the workpiece W, and the display unit  6  may display the target mounting position of the workpiece W. Rather than display the target mounting position or posture of the workpiece W at the display unit  6 , another method may be used to report these to the user. The configuration of the reporting part is not limited to the one explained above. 
         [0076]    The above explanation is only one example. The above embodiment and modifications do not limit the present invention so far as the features of the present invention are not impaired. The component elements of the embodiment and modifications include elements which can be replaced with them and are self evidently replaced with them while maintaining unity of invention. That is, other conceivable aspects in the scope of the technical concept of the present invention are also included in the scope of the present invention. Further, it is possible to combine the above embodiment and one or more of the modifications in any way. 
         [0077]    According to the present invention, a workpiece target mounting position or posture which enables an operating range of a machine tool in a predetermined feed axis direction to become within a movable range is found and reported to a user, so the user can easily grasp a workpiece mounting position or workpiece mounting posture which avoids stroke-over and the entire region of a workpiece can be smoothly processed based on a processing program.
     1 . CAM device     2 . NC device     5 . input unit     6 . display unit     10 . workpiece-attachment-information reporting device     11 . control unit     12 . path setting unit     13 . movable range setting unit     14 . posture setting unit     15 . range calculating unit     16 . target posture computing unit     17 . display control unit   MC. machine tool