Abstract:
The end portion processing apparatus includes an X-direction driving unit which allows a back-and-forth movement along an X-direction; a cutter supporting member which is supported by the X-direction driving unit, is able to run in a Y-direction, and supports a cutter member extending in a Z-direction which is perpendicular to the XY-plane; a guide member which has a shape matching to a processing planned shape when seeing from the Z-direction, and guides the cutter supporting member such that the cutter member moves to follow the processing planned shape; and a Y-direction position changing mechanism which changes the position in the Y-direction of the cutter supporting member to the work material. The Y-direction position changing mechanism changes the position of the cutter supporting member such that the cutter supporting member runs on further inner side in case of going back than in case of going forth.

Description:
TECHNOLOGY FIELD 
     The present invention relates to an end portion processing apparatus. 
     BACKGROUND ART 
     A technique of processing an end portion of a work material to a desired shape is known. For example, as shown in  FIG. 1 , in the process of the manufacture of a main wing panel of an aircraft, a plurality of conveyance hang tabs  101  are prepared for the end portion of the main wing panel  100 . When the main wing panel  100  is conveyed, the main wing panel  100  is suspended by use of the plurality of hang tabs  101 . The hang tabs  101  are finally unnecessary, and are cut and detached from the main wing panel  100 . In the cutting, it is required to process the end portion of the main wing panel  100  to be smooth. 
     In order to process the end portion of the work material to be smooth, a technique of cutting an unnecessary portion and using a sandpaper to polish the end portion is thought of. However, the polishing process takes time and the processing cost increases. 
     In relation to the above description, a method of processing the end portion of a carbon fiber reinforced plastic laminate board and so on is disclosed in Patent Literature 1 (Japanese Patent Publication (JP 2010-94800A)). In the method of processing the end portion, a principal axis of a processing machine is divided to have many axes and the machine becomes a multi-axis machine. Then, a rough processing tool and a finish processing tool are provided for the multiple axes. The end portion of the carbon fiber reinforced plastic laminate board is processed previously by the rough processing tool, and then the finish processing is carried out by the finish processing tool. Also, a technique that the carbon fiber reinforced plastic laminate board is controlled three-dimensionally in the position by an NC control machine is described in Patent Literature 1. 
     Citation List 
     [Patent Literature 1] JP 2010-94800A 
     SUMMARY OF THE INVENTION 
     According to Patent Literature 1, the position control of the work material is performed by using the NC control machine. However, when the work material is a large-scaled product such as the main wing panel of the aircraft, it is not practical to change the position of the work material in the processing. 
     Therefore, the present invention may provide an end portion processing apparatus which can process an end portion of a work material without moving the work material, to have a smooth shape. 
     The end portion processing apparatus according to the present invention is an end portion processing apparatus which processes an end portion of a work material arranged on the XY-plane. This end portion processing apparatus includes an X-direction driving unit which allows a back-and-forth movement along an X-direction; a cutter supporting member which is driven by said X-direction driving unit, is able to move in a Y-direction, and supports a cutter member extending in a Z-direction which is perpendicular to the XY-plane; a guide member which has a shape matching to a processing planned shape when seeing from the Z-direction, and guides said cutter supporting member such that said cutter member moves to follow the processing planned shape; and a Y-direction position changing mechanism which changes the position in the Y-direction of said cutter supporting member to the work material. The Y-direction position changing mechanism changes the position of said cutter supporting member such that said cutter supporting member runs on further inner side in case of going back than in case of going forth. 
     According to the present invention, when the X-direction driving unit operates, a cutter supporting member is guided to follow a guide member. As a result, the cutter member moves to match to a processing planned shape. Thus, it is possible to process the end portion of the work material without moving the work material, to have a desired shape. 
     In addition, a position of the cutter supporting member in a Y-direction is changed so that the cutter member moves in a further inside of the work material in case of going back than in case of going forth, by the Y-direction position changing mechanism. Thus, it is possible to roughly process the end portion of the work material is in case of going forth and perform the finish processing in case of going back. The cutter supporting member is subjected to back-and-forth movement by the X-direction driving unit, and as a result, the end portion of the work material can be processed to have a smooth shape. 
     According to the present invention, the end portion processing apparatus is provided which can processes the end portion of the work material without moving the work material, to have a smooth shape. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing a conventional example of a main wing panel; 
         FIG. 2  is a perspective view schematically showing an end portion processing apparatus according to a first embodiment; 
         FIG. 3  is a schematic diagram when seeing the end portion processing apparatus from the Z-direction; 
         FIG. 4  is a schematic diagram when seeing the end portion processing apparatus from the X-direction; 
         FIG. 5  is an expanded view showing a roller member; 
         FIG. 6A  is a schematic diagram showing a position of the cutter supporting member in case of going forth; 
         FIG. 6B  is a schematic diagram showing the position of the cutter supporting member in case of going back; 
         FIG. 7  is a schematic diagram showing the end portion processing apparatus according to a second embodiment; 
         FIG. 8  is a diagram showing the end portion processing apparatus according to a third embodiment; 
         FIG. 9  is a schematic diagram showing a structure of a pin supporting section; 
         FIG. 10A  is a schematic diagram showing the pin supporting section in a fourth embodiment; 
         FIG. 10B  is a schematic diagram showing the pin supporting section in the fourth embodiment; 
         FIG. 11A  is a schematic diagram showing a pin member according to a fifth embodiment; and 
         FIG. 11B  is a schematic diagram showing the pin member according to the fifth embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. 
     First Embodiment 
       FIG. 2  is a perspective view schematically showing an end portion processing apparatus  2  according to a first embodiment of the present invention. The end portion processing apparatus  2  is used to process an end portion of a work material  1 . 
     In the present embodiment, it is supposed that the work material  1  is a main wing panel of an aircraft. Also, it is supposed that the work material  1  is CFRP (carbon fiber reinforced plastic laminate board). The work material  1  has an almost flat plate-like shape and is arranged on an XY-plane. The end portion of the work material  1  extends along an X-direction. A hang tab  34  is provided for the end portion of the work material  1  to protrude into a Y-direction. 
     In the present embodiment, the end portion processing apparatus  2  is used to cut the hang tab  34 . The end portion processing apparatus  2  has a flat plate member  3  and a running unit  8 . The plate member  3  is provided to support the running unit  8  and is fixed to the work material  1 . The running unit  8  is fixed on the main surface of the plate member  3  by fixation pins  10 . The running unit  8  supports an end mill cutter  9  extending to a Z-direction and has a function to move the end mill cutter  9 . By moving the end mill cutter  9 , the hang tab  34  is cut and the end portion of the work material  1  is processed. 
       FIG. 3  is a schematic diagram when seeing the end portion processing apparatus  2  from the Z-direction. Also,  FIG. 4  is a schematic diagram when seeing the end portion processing apparatus  2  from the X-direction. Referring to  FIG. 2  to  FIG. 4 , the structure of the end portion processing apparatus  2  will be described in detail. 
     First, the structure of the plate member  3  will be described. 
     A part of the plate member  3  is located under the work material  1  to overlap with the work material  1 . The plate member  3  is fixed to the work material  1  by using clamps (not shown) and so on. A guide member  4 , a ditch  18 , a pair of Y-direction positioning pin members  5  and a X-direction positioning hole  7  are provided on the main surface of the plate member  1 . It should be noted that the Y-direction positioning pin member  5  and the X-direction positioning hole  7  are illustrated only in  FIG. 2 , and in  FIG. 3 , illustration of them is omitted. 
     The pair of the Y-direction positioning pin members  5  and the X-direction positioning hole  7  are provided to position the plate member  3 . 
     The X-direction positioning hole  7  is a long hole extending along the Y-direction. A reference hole to position the plate member  3  in the Y-direction is provided for the work material  1 . In the positioning, the reference hole is overlapped with the X-direction positioning hole  7  and the X-direction positioning pin member  6  is inserted. Thus, the plate member  3  is positioned in the X-direction with respect to the work material. 
     On the other hand, the pair of the Y-direction positioning pin members  5  are provided for end portions of the plate member  3  in the X-direction and rises upwardly from the main surface of the plate member  3 . By pushing the Y-direction positioning pin member  5  against the end portion of the work material  1 , the plate member  3  is positioned in the Y-direction. 
     If the plate member  3  is fixed to the work material  1  by using the clamps and so on after the plate member  3  is positioned in the X-direction and the Y-direction, it is possible to attach the plate member  3  to a desired position. 
     The guide member  4  is provided to guide the end mill cutter  9  to follow a processing planned shape. The guide member  4  has a guide ditch which has a shape corresponding to the processing planned shape. 
     A ditch  18  is provided to prevent the end mill cutter  9  from interfering with the plate member  3 . As shown in  FIG. 4 , the tip portion of the end mill cutter  9  is inserted into the ditch  18  and does not interfere with the plate member  3 . 
     Next, the structure of the running unit  8  will be described in detail. As shown in  FIG. 3 , the running unit  8  has an X-direction driving unit  14 , a cutter supporting member  15  and an air cylinder  17  (the pushing mechanism). 
     The X-direction driving unit  14  is composed of a motor  11 , a running axis member  12  and an X-direction moving member  13 . The running axis member  12  extends along the X-direction. The running axis member  12  is connected to the motor  11  and the motor  11  rotates it. The X-direction moving member  13  is attached to the running axis member  12  and moves along the X-direction as the running axis member  12  turns. That is, by rotating the running axis member  12  by the motor  11 , it is possible to move the X-direction moving member  13  along the X-direction. As the motor  11 , a servo motor is used. The motor  11  drives the X-direction moving member  13  to go back and forth. Also, the motor  11  is connected with a controller (not shown). A program for the running speed control is installed in the controller. The running speed of the X-direction moving member  13  is controlled by the program for the running speed control and is controlled according to the running position of the X-direction moving member  13 . 
     Also, as shown in  FIG. 4 , a rail member  35  extending along the Y-direction is attached to the X-direction moving member  13 . 
     The cutter supporting member  15  is provided to support the end mill cutter  9 . As shown in  FIG. 4 , the cutter supporting member  15  is arranged on a rail member  35  and is supported by the X-direction moving member  13  through the rail member  35 . The cutter supporting member  15  is movable into the Y-direction along the rail member  35 . 
     Also, the cutter supporting member  15  has a roller member  16 . The roller member  16  is inserted in the guide ditch provided for the guide member  4 . The roller member  16  is installed to be able to roll in the guide ditch. When the X-direction moving member  13  moves along the X-direction, the roller member  16  rolls in the guide ditch. As a result, the cutter supporting member  15  is guided by the guide ditch and the end mill cutter  9  moves to match to the processing planned shape. Thus, the end portion of the work material  1  is processed. 
     Here, in the present embodiment, the structure of the roller member  16  is devised.  FIG. 5  is a diagram showing by magnifying the roller member  16 . The diameter of the roller member  16  in the Y-direction is smaller than the width of the guide ditch as shown in  FIG. 5 , and a clearance c is generated between the roller member  16  and the side wall of the guide ditch. 
     An air cylinder  17  is provided to change the position of the cutter supporting member  15  to the work material  1  in the Y-direction. As shown in  FIG. 4 , the air cylinder  17  is connected to the X-direction moving member  13  at one end and is connected to the cutter supporting member  15  at the other end. The air cylinder  17  applies a force in the Y-direction to the cutter supporting member  15 . 
     Next, a method of operating the end portion processing apparatus  2  according to the present embodiment will be described. 
     First, the plate member  3  is positioned by using the Y-direction positioning pin member  5  and the X-direction positioning hole  7 . After the positioning, the plate member  3  is fixed on the work material  1  by using clamps and so on. Next, the running unit  8  is fixes on the plate member  3 . 
     Next, the X-direction driving unit  14  drives the X-direction moving member  13  to move in the X-direction so as to allow back-and-forth movement along the X-direction. 
     At this time, the air cylinder  17  applies tensile force to the cutter supporting member  15  in case of going forth.  FIG. 6A  is a schematic diagram showing the position of the cutter supporting member  15  in case of going forth. When the cutter supporting member  15  is pulled to the side of the air cylinder  17  as shown in  FIG. 6A , the roller member  16  abuts to one of the side walls of the guide ditch (a first surface  19 ). As a result, the roller member  16  follows one of the side walls and moves along it. Because the guide ditch has a shape corresponding to the processing planned shape, the end mill cutter  9  supported by the cutter supporting member  15  moves according to the processing planned shape. As a result, the hang tab  34  is cut out from the work material  1 . 
     On the other hand, the air cylinder  17  applies pushing force to the cutter supporting member  15  to in case of going back.  FIG. 6B  is a schematic diagram showing the position of the cutter supporting member  15  in in case of going back. When the cutter supporting member  15  is pushed by the air cylinder  17  as shown in  FIG. 6B , the roller member  16  abuts to the other side wall (a second surface  20 ) of the guide ditch. As a result, the roller member  16  follows the other side wall and moves. Therefore, in case of going back, the end mill cutter  9  moves along the inside of the plate member  3  by a clearance c (see  FIG. 5 ) than in case of going forth. Therefore, if the clearance c is set to a suitable value, the end portion of the work material  1  cut in case of going forth can be processed to perform finish processing in case of going back. 
     As described above, according to the present embodiment, because the guide member  4  is provided, the cutter supporting member  15  can be guided along the processing planned shape. Thus, the end portion of the work material  1  can be processed without moving the work material. Also, it is not necessary to use a large-sized apparatus like an NC processing machine, and the end portion of the work material  1  can be easily processed. 
     In addition, in the present embodiment, the diameter of the roller member  16  is set smaller than the width of the guide ditch. Thus, the roller member  16  is pushed to one of the side walls in case of going forth by the air cylinder  17  and the roller member  16  is pushed to the other side wall in case of going back. That is, the line which the end mill cutter  9  moves can be easily changed by the air cylinder  17  in case of going back and forth. As a result, both of rough processing and finish processing can be performed only by the X-direction driving unit  14  operating in case of going back-and-forth. 
     Also, in the present embodiment, the running unit  8  is attached to the plate member  3  detachably. That is, it is possible to separate the guide member  4  and the running unit  8 . Many hang tabs  34  are generally provided for the main wing panel of the aircraft. The processing shape sometimes depends on the positions of the hang tabs  34 . Even in such a case, if the guide member  4  (the plate member  3 ) is prepared previously every processing shape, a different portion can be processed by using the identical running unit  8 . Also, the cutter supporting member  15  can be easily separated into parts  15   a  and  15   b , so that detachablity of the running unit  8  is improved, and although the board thickness is different from every hang tab  34 , movement speed in the X-direction can be set flexibly by a controller (see  FIG. 4 ). 
     Also, it is desirable that in case of going back, the X-direction driving unit drives the X-direction moving member  13  to move in the X-direction at higher speed than in case of going forth. The end mill cutter  9  cuts the hang tab  34  in case of going forth. Therefore, the resistance which is applied to the end mill cutter  9  in processing becomes large. When the X-direction moving member  13  is moved at high speed in case of going forth, it is easy for the shape of the end portion of the work material  1  to become rough. Therefore, in case of going forth, the X-direction moving member  13  is moved at a lower speed. On the other hand, the resistance which is applied to the end mill cutter  9  in case of going back is smaller than in case of going forth. Therefore, even if the X-direction moving member  13  is moved at high speed, it is possible to obtain a sufficiently smooth shape after the processing. Also, by moving the X-direction moving member  13  at high speed in case of going back, it is possible to reduce processing time of the work material  1 . 
     It should be noted that in the present embodiment, a case that the work material  1  is the main wing panel made from CFRP has been described. However, the work material  1  is not limited to the main wing panel made from CFRP, and the end portion processing apparatus  2  of the present embodiment can be applied to another work material  1 . Also, the main wing panel made from CFRP is large-sized and it is required that it has a smooth shape after the processing. From these viewpoints, the end portion processing apparatus  2  according to the present embodiment can be used to suitably process the main wing panel made from CFRP. It should be noted that it is desirable that the clearance c is set to about 0.5 mm when the work material  1  is the main wing panel made from CFRP. 
     Second Embodiment 
     Next, a second embodiment will be described.  FIG. 7  is a schematic diagram showing the end portion processing apparatus  2  according to the present embodiment. In the present embodiment, the structures of the guide member  4  and the cutter supporting member  15  are changed from those of the first embodiment. Because the other structures in the first embodiment can be adopted as they are, a detailed description is omitted. 
     As shown in  FIG. 7 , in the present embodiment, the first surface  19  and the second surface  20  are prepared for the guide member  4 . The first surface  19  and the second surface  20  turn the directions opposing to each other in the Y-direction. On the other hand, a pair of abutment members  21  ( 21 - 1 ,  21 - 2 ) are provided for the cutter supporting member  15 . The pair of abutment members  21  are arranged in a position so as to put the guide member  4  between them in the Y-direction. Each of the abutment members  21  is a roller member. Here, a distance between the abutment members  21  ( 21 - 1 ,  21 - 2 ) is larger by the clearance c than the distance between the first surface  19  and the second surface  20 . 
     In the present embodiment, like the first embodiment, the air cylinder  17  (not illustrated in  FIG. 7 ) pulls the cutter supporting member  15  in case of going forth. By this, one  21 - 2  of the abutment members abuts to the first surface  19  of the guide member  4 . On the other hand, in case of going back, the air cylinder  17  pushes the cutter supporting member  15 . By this, the other abutment member  21 - 1  abuts to the second surface  20 . That is, the position of the end mill cutter  9  can be changed in the Y-direction by the air cylinder  17 . Thus, like the first embodiment, it possible to perform rough processing in case of going forth and finish processing in case of going back. 
     Third Embodiment 
     Next, a third embodiment will be described. In the above embodiments, relative position relation between the cutter supporting member  15  and the guide member  4  is changed in the Y-direction, and the position of the end mill cutter  9  to the work material  1  is changed in the Y-direction. On the other hand, in the present embodiment, the position of the plate member  3  to the work material  1  is changed in the Y-direction and the position of the end mill cutter  9  is changed in the Y-direction. 
       FIG. 8  is a diagram schematically showing the end portion processing apparatus  2  according to the present embodiment. It should be noted that for convenience of explanation, only a part is illustrated in  FIG. 8  to explain the present embodiment, and the illustration of the running unit  8  and so on is omitted. In the following description, a part where there is not any explanation is the same as that of the above embodiments. 
     As shown in  FIG. 8 , in the present embodiment, a pin supporting section  24  is provided for the main surface of the plate member  3  in place of the Y-direction pin positioning member  5  (see  FIG. 2 ). The pin supporting section  24  is composed of a pair of first pin supporting sections  22  and a pair of second pin supporting sections  23 . The pair of first pin supporting sections  22  and the pair of second pin supporting sections  23  are formed as a concave section and are configured as a support of pin members  25 . Here, the pair of the first pin supporting sections  22  and the pair of the second pin supporting sections  23  are provided on different positions in the Y-direction. Specifically, the pair of the second pin supporting sections  23  is provided for the position nearer to the guide member  4  than the pair of the first pin supporting sections  22 . 
     Next, a method of operating the end portion processing apparatus  2  according to the present embodiment will be described. 
     (a) of  FIG. 9  is a schematic diagram showing the structure of the pin supporting section  24  in case of going forth. In the present embodiment, when the plate member  3  is positioned, the pin members  25  are installed in the pair of the first pin supporting sections  22 . The pin members  25  stand upwardly from the plate member  3 . After that, the pin members  25  abut to the end of the work material  1  so that the plate member  3  is positioned in the Y-direction. After the positioning, like the previous embodiments, the plate member  3  is fixed to the work material  1  by using the clamps and so on. Moreover, an operation in case of going forth is executed by the X-direction driving unit  14 , to cut the hang tab  34 . 
     (b) of  FIG. 9  is a schematic diagram showing the structure of the pin supporting section  24  in case of going back. When the operation in case of going forth ends, the clamps and so on are removed. Then, the pin members  25  are moved to the pair of the second pin supporting sections  23  from the pair of the first pin supporting sections  22 . Again, the plate member  3  is positioned so that the pin members  25  abut to the end portion of the work material  1 . Moreover, the plate member  3  is fixed by the clamps and so on. As shown by (b) of  FIG. 9 , the plate member  3  goes under the work material  1  more deeply than in case of gong forth. As a result, the position of the plate member  3  is shifted in an inside direction as a whole in the Y-direction, and the position of the end mill cutter  9  (not illustrated in  FIG. 9 ) is changed into the inside direction. After that, an operation in case of going back is executed by the X-direction driving unit  14 . Thus, the finish processing is performed. 
     In the present embodiment, the pin supporting section  24  functions in case of going forth and in case of going back as a Y-direction position changing mechanism in which the position of the end mill cutter  9  is changed in the Y-direction. As a result, like the previous embodiments, the hang tab  34  is cut in case of going forth and the finish processing is performed in case of going back. 
     It should be noted that in the present embodiment, the position of the end portion processing apparatus  2  is shifted as a whole in the Y-direction. Therefore, like the previous embodiments, the clearance c does not have to be provided between the cutter supporting member  15  and the guide member  4 . Also, it does not always need the air cylinder  17 . 
     Fourth Embodiment 
     Next, a fourth embodiment will be described. In the present embodiment, the structures of the pin supporting section  24  and the pin member  25  are changed from those of the third embodiment. Because the other components are the same as those of the third embodiment, a detailed description is omitted. 
       FIG. 10A  is a schematic diagram showing the pin supporting section  24  of the present embodiment. In the present embodiment, a pair of pin insertion holes  28  are provided for the pin supporting section  24 . It should be noted that only one of the pair of pin insertion holes is drawn in  FIG. 10A . The pin member  25  is inserted into the pin insertion hole  28 . Here, the pin member  25  has an abutment section  27  which penetrates or passes through the pin insertion hole  28  and protrudes on the main surface of the plate member  3 . A pipe-shape color (pipe member  29 ) is attached to this abutment section  27  detachably. 
     Next, a method of operating the end portion processing apparatus  2  according to the present embodiment will be described. 
     In the present embodiment, first, when the plate member  3  is positioned in the Y-direction, the pin member  25  with the pipe member  29  attached is inserted in the pin insertion hole  28  (see  FIG. 10A ). Then, the pin member  25  is pushed to the end of the work material  1  and a position of the plate member  3  in the Y-direction is determined. In this case, the pin member  25  abuts to the work material  1  by the pipe member  29 . After that, like the third embodiment, the operation in case of going forth is executed. 
     On the other hand, when the operation in case of going forth ends, the pin member  25  is removed and the pipe member  29  is removed from the pin member  25 . Then, the pin member  25  with pipe member  29  removed as shown in  FIG. 10B  is again inserted in the pin insertion hole  28 . After that, the pin member  25  abuts to the end of the work material  1  again and the plate member  3  is positioned in the Y-direction. In this case, because the pipe member  29  is removed from the pin member  25 , the plate member  3  is shifted into the inside direction for the thickness of pipe member  29  in case of going back. That is, the plate member  3  is shifted inside in the Y-direction. As a result, the position of the end mill cutter  9  becomes able to be changed in the Y-direction in case of going forth and in case of going back, like the third embodiment. Like the previous embodiments, the work material  1  is cut in case of going forth, and the finish processing is performed in case of going back. 
     Fifth Embodiment 
     Next, a fifth embodiment will be described. In the present embodiment, the structure of the pin member  25  is changed from that of the fourth embodiment. Because the other structures are the same as those of the fourth embodiment, a detailed description is omitted. 
       FIG. 11A  is a schematic diagram showing the pin member  25  according to the present embodiment. As shown in  FIG. 11A , the pin member  25  has a base section  32 , a large diameter section  31  and a small diameter section  33 . The outer diameter of the base section  32  is larger than the pin insertion hole  28 . The large diameter section  31  extends upwardly to protrude from the base section  32  and is formed to have the size possible to be inserted in the pin insertion hole  28 . The small diameter section  33  extends upwardly to protrude from the large diameter section  31  and the outer diameter thereof is smaller than the large diameter section  31 . Also, the height of the large diameter section  31  is larger than the board thickness of the plate member  3 . 
     Next, a method of operating the end portion processing apparatus  2  according to the present embodiment will be described. 
     In the present embodiment, first, when the plate member  3  is positioned in the Y-direction, the pin member  25  is inserted in the pin insertion hole  28  (see  FIG. 11A ). At this time, the pin member  25  inserted so that the base section  32  is brought contact with the back surface of the plate member  3 . A part of the large diameter section  31  protrudes from the main surface of the plate member  3 . In this condition, the pin member  25  is abutted to the end of the work material  1  to position the plate member  3 . At this time, the pin member  25  abuts with the work material  1  at the large diameter section  31 . After that, like the fourth embodiment, the operation in case of going forth is executed. 
     When the operation in case of going forth ends, the insertion depth of the pin member  25  is changed. Specifically, as shown in  FIG. 11B , the insertion depth is changed so that the small diameter section  33  protrudes from the main surface of the plate member  3 . After that, the pin member  25  is abutted to the end of the work material  1  again to position the plate member  3 . In this case, the pin member  25  is brought contact with the work material  1  in the small diameter section  33 . Due to a difference between the large diameter section  31  and the small diameter section  33  in the outer diameter, the plate member  3  goes into a portion under the work material  1  deeply. As a result, the position of the end mill cutter  9  can be changed in the Y-direction in case of going forth and in case of going back, like the fourth embodiment. Like the previous embodiments, the work material  1  is cut in case of going forth, and the finish processing is carried out in case of going back. 
     As described above, the first to fifth embodiments of the present invention have been described. It should be noted that these embodiments are not independent each other and can be combined in a range where there is no contradiction. 
     This application claims a priority on convention based on Japanese patent application No. JP 2011-000792 filed on Jan. 5, 2011. The disclosure thereof is incorporated herein by reference.