Patent Publication Number: US-2002002419-A1

Title: Method of controlling lifetime of complex tool

Description:
BACKGROUND OF THE INVENTION  
       [0001] This invention relates to method of controlling lifetime of complex tool, having a plurality of inserts on a single holder portion, capable of performing turning machining and rotational tool machining such as drilling/milling machining (So-called “milling machining” in the present specification usually includes fraise machining to be used as the same meaning as milling machining.) with one tool.  
       [0002] The proposal in recent years is that the complex tool installing a plurality of inserts on a single tool is used and turning machining and rotational tool machining such as drilling/milling machining are performed selectively using these inserts for machining on a workpiece such that the trouble of exchange of tool is omitted and the machining efficiency is improved. But, the problem as to how to control lifetime of the complex tool installing a plurality of inserts thereon has not yet been resolved. So, a desire for development of some effective method of controlling lifetime is increasing.  
       [0003] The object of the present invention is to provide method of controlling lifetime of complex tool, capable of properly executing control of lifetime of the complex tool installing a plurality of inserts thereon, taking the above-mentioned circumstances into consideration.  
       SUMMARY OF THE INVENTION  
       [0004] The invention of claim  1  is method of controlling lifetime of a complex tool, said complex tool having a main body on which a plurality of inserts are installed, capable of performing turning machining and rotational tool machining by using a single or simultaneously using some of a plurality of said inserts; said method comprising:  
       [0005] judging lifetime of said complex tool by integrating machining time element every insert installed on said complex tool; and  
       [0006] judging such that when expiration of lifetime of at least one of said these inserts is judged, said complex tool installing said insert which expiration of lifetime is judged reaches expiration of lifetime.  
       [0007] According to the invention of claim  1 , when only one insert of the inserts comprising the complex tool reaches expiration of lifetime, the machining with the complex tool can be immediately stopped. Then, such situation that a lowering of machining accuracy by continuing to use the insert which reaches expiration of lifetime can be avoided. Since the machining time element is integrated every insert, the inserts which reaches expiration of lifetime and others of the same complex tool can be clearly differentiated from one another. Therefore, by exchanging only insert which reaches expiration of lifetime, the complex tool can be immediately reused for machining. Then, idle time is shortened and tool maintenance is made easier.  
       [0008] The invention of claim  2  is the method of controlling lifetime of the complex tool wherein said machining time element is an used time for using the insert when a workpiece is machined.  
       [0009] According to the invention of claim  2 , the expiration of lifetime of each insert can be correctly controlled since the machining time element to be integrated is the used time of the insert.  
       [0010] The invention of claim  3  is the method of controlling lifetime of the complex tool wherein said machining time element is a machining number of workpieces by the insert.  
       [0011] According to the invention of claim  3 , the machining time element to be integrated is the machining number of workpieces by the insert. When many of the same workpieces are machined, the expiration of lifetime of the complex tool can be controlled by the number of workpieces machined. So, it is not necessary to separately measure machining time, and its control is easy.  
       [0012] The invention of claim  4  is the method of controlling lifetime of the complex tool wherein when said machining time element is integrated, the machining time element is integrated concerning single insert of said inserts installed on said complex tool in case of the machining using single insert, and the machining time element is respectively integrated concerning a plurality of the inserts of the inserts installed on the complex tool in case of the machining simultaneously using a plurality of said inserts.  
       [0013] According to the invention of claim  4 , the expiration of lifetime of each insert comprising the complex tool is integrated and judged, reflecting the actual using situation of each insert. So, correct control of expiration of lifetime according to machining contents is possible. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0014]FIG. 1 is a control block diagram showing an example of a complex machining machine tool to which the present invention is applied;  
     [0015]FIG. 2 is a view obliquely showing an example of a workpiece to be machined;  
     [0016]FIG. 3 is a typical view for explaining an example of tool data stored in tool file and its contents;  
     [0017]FIG. 4 is a view obliquely showing an example of a complex tool;  
     [0018]FIGS. 5, 6,  7 , and  8  are views showing details when the workpiece as shown in FIG. 2 is machined with the complex tool;  
     [0019]FIG. 9 is a typical view for showing an example of lifetime control file; and  
     [0020]FIG. 10 is an example of machining with the complex tool, (a) is a view for showing an example of turning and (b) is a view for showing an example of milling. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0021] A complex machining machine tool  1  has a main control portion  2 , as shown in FIG. 1. With the main control portion  2 , an input portion, such as a keyboard  5 , a system program memory  6 , a tool file  7 , a tool data controlling portion  8 , a machining program memory  9 , a spindle control portion  10 , a tool rest control portion  11  and a display  12  are connected through a bus line  3 . A spindle motor  13  is connected with the spindle control portion  10 . With the spindle motor  13 , a spindle  15 , being free to rotate, drive and position with axial center CT provided parallel to Z-axis as its center is connected. With the spindle  15 , a chuck  16  is provided. Claws  16   a  are provided with the chuck  16 , being free to hold and release a workpiece  17  to be machined, being free to move and drive in the direction as shown by arrows C and D.  
     [0022] Tool rest driving motors  19  (the plural number) are connected with the tool rest control portion  11 . A tool rest  20  is connected with the tool rest driving motor  19 , being free to move and drive in the Z-axis direction and in the direction as shown by arrows E and F rectangular to the Z-axis, that is, in the X-axis direction by the tool rest driving motor  19 . Furthermore, the tool rest  20  is provided, being free to move and drive in Y-axis direction rectangular to the X-axis and Z-axis, and rectangular to the paper , and in the direction as shown by arrows G and H which is B-axis direction with the Y-axis as its center by the tool rest driving motor  19 .  
     [0023] A tool holding portion  20   a  is formed on the tool rest  20 . A turning tool, a milling/drilling tool, and a complex tool  21  capable of turning and milling/drilling machining are provided with the tool holding portion  20   a,  being free to attach, detach and exchange. The tool holding portion  20   a  is provided, being free to fix and hold the complex tool and other tools in a predetermined holding state, and being free to rotate, drive and position around axial center CT 2 .  
     [0024] The complex tool  21  has a main body  21   a  formed in round bar shape, as shown in FIG. 4. On the top of the main body  21   a,  an insert installation portion  21   b  is formed. Four inserts  22 ,  23 ,  25  and  26  are respectively installed on the insert installation portion  21   b  at the pitch of 90° with axial center CT 3  of the main body  21   a  as its center so as to attach and detach. As shown in FIG. 3( a ), indexing number KD is set for each insert. The indexing number KD is set as 1 for the insert  22 , and clockwise, the indexing number KD is 2 for the insert  23 , the indexing number KD is 3 for the insert  25  and the indexing number KD is 4 for the insert  26 .  
     [0025] Tool name is allotted to the respective inserts  22 ,  23 ,  25  and  26  as a virtual tool according to the machining contents to be performed with the complex tool  21 . For the insert  22  which indexing number KD is 1, three kinds of tool name, {circle over (1)} turning drill for performing drilling machining wherein tool itself does not rotate, {circle over (6)} milling drill for performing drilling machining wherein tool itself rotates and {circle over (7)} end mill for performing milling machining is allotted as a virtual tool, as shown in FIG. 3( c ). For the insert  23  which indexing number KD is 2, tool name NA, {circle over (4)} inside diameter rough machining for performing turning rough machining on inside diameter is allotted, for the insert  25  which indexing number KD is 3, tool name NA, {circle over (2)} outside diameter rough machining for performing turning rough machining on outside diameter is allotted, and for the insert  26  which indexing number KD is 4, tool name NA, {circle over (3)} outside diameter finishing for performing turning finishing machining on outside diameter and {circle over (5)} inside diameter finishing for performing turning finishing machining on inside diameter is allotted as a virtual tool.  
     [0026] The complex machining machine tool  1  has the before-mentioned structure. Then, in order to machine the cylindrical workpiece  17  which diameter is D1, for instance, as shown in FIG. 2, an operator inputs various kinds of machining data by a known automatic programming method, operating the keyboard  5  so as to compose machining program. On this occasion, the main control portion  2  composes the machining program PRO on the basis of the various kinds of data input by an operator according to a known automatic program composing program stored in the system program memory  6 , then the composed machining program PRO is stored in the machining program memory  9 .  
     [0027] After the machining program PRO concerning the workpiece  17  is composed, an operator instructs the main control portion  2  to machine the workpiece  17  through the keyboard  5 . Receiving this instruction, the main control portion  2  reads out the machining program PRO concerning the workpiece  17  from the machining program memory  9  so as to execute machining, appropriately driving the spindle control portion  10  and the tool rest control portion  11 .  
     [0028] As shown in (M 1 ) of FIG. 5, at the machining on the workpiece  17 , the machining for forming a hole  17   a  on the central portion of the workpiece  17  by a drill is firstly performed. The tool to be used at this time is designated by the machining program PRO. The main control portion  2  refers to the tool file  7  when the tool to be used is designated by the machining program PRO, and reads out tool data TL of the corresponding tool.  
     [0029] In the tool file  7 , tool number TN, tool setting direction DR, tool name NA, nominal diameter/tool angle CA, suffix DC, rotational direction/tool character RT, tool diameter/ tool edge R DM, finishing machining/rough machining division RF of the tool data DAT are set for each tool as chart data DAT 1 , as shown in FIG. 3( b ) . Furthermore, detailed data concerning each tool is stored as detailed data DAT 2 .  
     [0030] The complex tool  21  is set as an independent tool in this tool file  7 , dividing into a plurality of virtual tools according to the machining contents capable of machining with the complex tool  21 . For instance, seven virtual tools, on which the tool name NA and the suffix DC from {circle over (1)} to {circle over (7)} mentioned before are affixed, are stored as the tool number TN  1  (the example of FIG. 3( b ) is one example, and if the machining form with the complex tool  21  extends over many kinds, the virtual tools having many of tool name NA and suffix DC according to the machining kind are registered). That is, every machining contents allotted to the respective inserts  22  of the complex tool  21 , the tool data of the inserts  22 ,  23 ,  25 ,  26  for performing the machining contents is stored in the tool file  7 , regarding the respective inserts as an independent tool. For instance, the virtual tools {circle over (1)} through {circle over (7)} corresponding to each virtual tool name NA as shown in FIG. 3( c ) are stored, corresponding to {circle over (1)} through {circle over (7)} in FIG. 3( b ).  
     [0031] That is, the virtual tool of O(turning drill of FIG. 3( c ) is registered in such a manner that tool number Tno is 1, tool setting direction is←, tool name NA is DRL EDG, nominal diameter/tool angle CA is 180, suffix DC is A, rotational direction/tool character RT is right rotation, and tool diameter/tool edge R DM is 50, as shown in {circle over (1)} of  
     [0032]FIG. 3( b ). On this occasion, tool setting direction DR shows the tool direction as default value by the direction of an arrow, “←” shows the direction wherein the direction of the tool is parallel to the Z-axis, that is, the B-axis angle is 0° and “⇓” shows the direction wherein the direction of the tool is parallel to the X-axis, that is, the B-axis angle is 90°.  
     [0033] The virtual tool of {circle over (2)} outside diameter rough machining of FIG. 3( c ) is registered in such a manner that tool number TNo is 1, tool setting direction DR is⇓, tool name NA is GNL OUT, nominal diameter/tool angle CA is 75, suffix DC is B, rotational direction/tool character RT is left hand/right rotation, tool diameter/tool edge R DM is 0.4, finishing machining/rough machining division RF is R (rough machining), as shown in {circle over (2)} of FIG. 3( b ). The virtual tool of {circle over (3)} outside diameter finishing machining of FIG. 3( c ) is registered in such a manner that tool number TNo is 1, tool setting direction DR is⇓, tool name NA is GNL OUT, nominal diameter/tool angle CA is 40, suffix DC is C, rotational direction/tool character RT is right hand/left rotation, tool diameter/tool edge R DM is 0.2, finishing machining/rough machining division RF is F (finishing machining), as shown in {circle over (3)} of FIG. 3( b ).  
     [0034] Furthermore, the virtual tool of {circle over (4)} inside diameter rough machining of FIG. 3( c ) is registered in such a manner that tool number TNo is 1, tool setting direction DR is←, tool name NA is GNL IN, nominal diameter/tool angle CA is 75, suffix DC is D, rotational direction/tool character RT is right hand/left rotation, tool diameter/tool edge R DM is 0.4, finishing machining/rough machining division RF is R (roughmachining), as shown in {circle over (4)} of FIG. 3( b ) The virtual tool of {circle over (5)} inside diameter finishing machining of FIG. 3( c ) is registered in such a manner that tool number TNo is 1, tool setting direction DR is←, tool name NA is GNL IN, nominal diameter/tool angle CA is 40, suffix DC is E, rotational direction/tool character RT is right hand/left rotation, tool diameter/tool edge R DM is 0.2, finishing machining/rough machining division RF is F (rough machining), as shown in {circle over (5)} of FIG. 3( b ).  
     [0035] The virtual tool of {circle over (6)} mill drill of FIG. 3( c ) is registered in such a manner that tool number TNo is 1, tool setting direction DR is⇓, tool name NA is drill, nominal diameter/tool angle CA is 50, suffix DC is H. rotational direction/tool character RT is left direction, as shown in {circle over (6)} of FIG. 3( b ). The virtual tool of (Mend mill of FIG. 3( c ) is registered in such a manner that tool number TNo is 1, tool setting direction DR is⇓, tool name NA is end mill, nominal diameter/tool angle CA is 50, suffix DC is J, rotational direction/tool character RT is right direction and tool diameter/tool edge R DM is 50, as shown in {circle over (7)} of FIG. 3( b ).  
     [0036] Then, in the machining program PRO, as the tool to be used in the machining program PRO, the tool name NA and the suffix DC of the corresponding virtual tool are designated, regardless of use of the complex tool  21  in the machining, similar to the case of designating a normal tool even if the complex  21  is used. In case of the machining (M 1 ) for forming the hole  17   a  on the central portion of the workpiece  17  as shown in FIG. 5 as mentioned before, the virtual tool of {circle over (1)} turning drill of the complex tool  21  is used as a tool. So, in this designation, the tool name NA “DRL EDG” and the suffix DC “A” are input in the machining program PRO, similar to a normal tool designation. By doing so, the tool designation finishes only by acknowledging and designating each virtual tool in the tool file  7  by an operator without understanding the whole complex tool  21  at the time of composing the machining program PRO. Then, the composing of the machining program PRO is possible with no specific knowledge concerning the complex tool  21 . Then, the main control portion  2  searches the tool data DAT of the tool file  7  so as to select the corresponding tool, that is, the virtual tool wherein the tool number TNo as shown in {circle over (1)} of FIG. 3( b ) is 1 and tool name NA is “DRL EDG” and suffix DC is “A” as shown on the most upper hand of the figure, and instructs the tool rest control portion  11  to index the tool at the machining position. In the tool file  7 , the respective tools (including {circle over (1)} through {circle over (7)} as “virtual tool” regarded seven independent tools of the complex tool  21 ) are differentiated by tool name NA and suffix DC concerning turning machining related tool (in case of the same tool name NA, it is differentiated by changing suffix DC into “A”, “B”, “C”, “D” and “E”), and are differentiated by tool name NA and nominal diameter/tool angle CA concerning the milling machining related tool, regardless of being the complex tool  21  or not. Then, when tool name NA and suffix DC or tool name NA and nominal diameter/tool angle CA are designated in the machining program PRO, the corresponding tool is immediately determined.  
     [0037] The tool rest control portion  11  drives the tool exchanger which is not shown, and selects the complex tool  21  which tool number TNo is 1 from the tool magazine which is not shown so as to install on the tool rest  20 . When the complex tool  21  is installed on the tool rest  20 , the tool rest control portion  11  refers to the detailed data DAT 2  corresponding to {circle over (1)} turning drill from tool name NA and suffix DC designated in the machining program PRO, and reads out the indexing number KD concerning {circle over (1)} turning drill and the B-axis angle of the complex tool  21  shown in the detailed data DAT 2 .  
     [0038] The tool rest control portion  11  drives and controls a tool driving motor (not shown) built in the tool rest on the basis of the read indexing number KD concerning {circle over (1)} turning drill and the B-axis angle so as to rotate the complex tool  21  around the axial center CT 3 . Then, the complex tool  21  is positioned so as to be in the state that indexing number KD is 1. As shown in FIG. 3( a ), the state that the indexing number is 1 is one that the insert  22  is positioned, facing the upper hand in the figure (the Y-axis direction). Furthermore, the B-axis driving motor which is not shown is driven, and the tool rest  20  is moved and driven in the direction as shown by the arrows G and H. and the complex tool  21  is positioned so as to be such a state that the B-axis angular position is 0°, and it is parallel to the Z-axis, as shown in FIG. 3( c ). In this state, the spindle  15  is rotated and driven at a predetermined rotational number by the spindle driving motor  13 , and the complex tool  21  is moved and driven in the arrow A direction of the Z-axis direction so as to form the hole  17   a  having a predetermined depth on the rotating workpiece  17  by the insert  22 , as shown in FIG. 5(M 1 ).  
     [0039] Subsequently, an end face  17   b  of FIG. 5(M 2 ) is machined by the insert  22  of the complex tool  21 . In this case, the tool rest control portion  11  drives the B-axis driving motor with such a state that the tool of {circle over (1)} turning drill is selected so as to rotate and drive the tool rest  20  a predetermined angle in the direction as shown by the arrow H of the B-axis. As shown in FIG. 5(M 2 ), the complex tool  21  is held in slightly inclined state with respect to the Z-axis, and the end face  17   b  of the workpiece is machined by the same insert  22 .  
     [0040] Next, rough machining is performed on an outside diameter  17   c  of the workpiece  17  of FIG. 5(M 3 ) by the complex tool  21 . In this case, in the machining program PRO, the virtual tool is designated, inputting “GNL OUT” as tool name NA and “B” as suffix DC. Then, the main control portion  2  searches the tool data DAT of the tool file  7 , and selects the corresponding tool, that is, the virtual tool which tool name NA is “GNL OUT” and suffix DC is “B”, which tool number is 1 shown on the second from the upper of the figure as shown in {circle over (2)} of FIG. 3( b ), and instructs the tool rest control portion  11  to index the tool to the machining position.  
     [0041] The tool rest control portion  11  refers to the detailed data DAT 2  corresponding to {circle over (2)} outside diameter rough machining from tool name NA and suffix DC designated in the machining program PRO and reads out the indexing number “ 3 ” and the B-axis angle “ 112 °” concerning {circle over (2)} outside diameter rough machining of the complex tool  21  as shown in the detailed data DAT 2 .  
     [0042] The tool rest control portion  11  drives and controls the tool driving motor (not shown) built in the tool rest on the basis of the read indexing number “ 3 ” and the B-axis angle “ 112 °” concerning {circle over (2)} outside diameter rough machining so as to rotate the complex tool  21  around the axial center CT 3 . Then, the complex tool  21  is positioned so as to become to be such a state that indexing number KD is  3  as shown in FIG. 3( a ). Furthermore, the B-axis driving motor which is not shown is driven so as to move and drive the tool rest  20  in the direction as shown by the arrows G and H of the B-axis direction. Then, the complex tool  21  is positioned so as to become to be such a state that the B-axis angular position is 112° anticlockwise with respect to the Z-axis as shown in FIG. 5(M 3 ). In this state, as shown in FIG. 5 (M 3 ) , the complex tool  21  is moved and driven in the direction as shown by the arrow A of the Z-axis direction so as to machine the outside diameter  17   c  of the rotating workpiece  17  the predetermined length L 1  by the insert  25 .  
     [0043] Next, finishing machining is performed on an inside diameter  17   d  of the workpiece  17  of FIG. 6(M 4 ) by the complex tool  21 . In this case, in the machining program PRO, the virtual tool is designated, inputting “GNL IN” as tool name NA and “E” as suffix DC. Then, the main control portion  2  searches the tool data DAT of the tool file  7 , and selects the corresponding tool, that is, the virtual tool which tool name NA is “GNL IN” and suffix DC is “E”, which tool number TN is 1 as shown on the fifth from the upper of the figure as shown in {circle over (5)} of FIG. 3( b ), and instructs the tool rest control portion  11  to index the tool to the machining position.  
     [0044] The tool rest control portion  11  refers to the detailed data DAT 2  corresponding to {circle over (5)} inside diameter finishing machining from tool name NA and suffix DC designated in the machining program PRO and reads out the indexing number “ 4 ” and the B-axis angle “ 0 ” concerning {circle over (5)} inside diameter finishing machining of the complex tool  21  as shown in the detailed data DAT 2 .  
     [0045] The tool rest control portion  11  drives and controls the tool driving motor (not shown) built in the tool rest on the basis of the read indexing number “ 4 ” and the B-axis angle “0°” concerning {circle over (5)} inside diameter finishing machining so as to rotate the complex tool  21  around the axial center CT 3 . Then, the complex tool  21  is positioned so as to become to be such a state that the indexing number KD is 4 as shown in FIG. 3( a ). Furthermore, the B-axis driving motor which is not shown is driven so as to move and drive the tool rest  20  in the direction as shown by the arrows G and H of the B-axis direction. Then, the complex tool  21  is positioned such that the B-axis angular position is 0° with respect to the Z-axis, that is, so as to be parallel, as shown in FIG. 6(M 4 ). In this state, as shown in FIG. 6(M 4 ), the complex tool  21  is moved and driven in the direction as shown by the arrow A of the Z-axis direction so as to machine the inside diameter  17   d  of the rotating workpiece  17  the predetermined length by the insert  26 .  
     [0046] In this way, as shown in (M 5 ), (M 6 ) of FIG. 6 and (M 7 ), (M 8 ) of FIG. 7, the respective inserts  22 ,  23 ,  25 ,  26  of the same complex tool  21  are rotated around the tool axial center CT 3  on the basis of the tool data DAT stored in the tool file  7  so as to selectively index and position the insert to be used for machining. And, the tool rest is properly rotated and positioned in the B-axis angular direction so as to perform various kinds of machining, such as the outside diameter finishing machining as shown in (M 5 ) of FIG. 6, the outside diameter slot machining as shown in (M 6 ) of FIG. 6, the inside diameter screw machining as shown (M 7 ) of FIG. 7, and the outside diameter screw machining as shown in (M 8 ) of FIG. 7, on the workpiece  17  by the respective inserts  22 ,  23 ,  25  and  26 . On this occasion, the virtual tools {circle over (1)} through {circle over (7)} as shown in FIG. 3( c ) are not used in a part of the machining concerning FIGS. 6 and 7. But, in this case also, the machining is performed using the virtual tools concerning the complex tool  21  of FIG. 4 set and stored in another part of the tool file  7 . For instance, the virtual tool to be used for outside diameter finishing machining of FIG. 6 (M 5 ) is one which tool number TN is 1 (showing the complex tool  21 ), tool name NA is “GNL OUT”, suffix DC is “K”, indexing number KD is “ 2 ” and B-axis angle is “5°” in the tool file  7 , and this is the machining with the insert  26 .  
     [0047] When the turning machining on the workpiece  17  finishes in this way, the milling machining as shown in FIG. 8 (M 9 ), (M 10 ) and (M 11 ) is performed at this time. In this case also, (M 9 ) face machining, (M 10 ) drilling machining and (M 11 ) spot facing machining is performed on the workpiece  17  using {circle over (6)} milling drill and {circle over (7)} end mill of the virtual tools concerning the complex tool  21  set in the tool file  7  of the complex tool  21 . {circle over (6)} Milling drill and {circle over (7)} end mill of the virtual tools are the machining by the insert  22  both which indexing number is 1, as shown in FIG. 3( c ). Then, the milling machining is performed in such a manner that the workpiece  17  held by the spindle is fixedly held around the Z-axis or is rotated with C-axis control, changing the B-axis angle, rotating the complex tool  21  at a high speed with the axial center CT 2  as its center.  
     [0048] By machining as mentioned before, the cutting machining can be performed on the workpiece as shown in FIG. 2, for instance, from a round bar with one complex tool  21 .  
     [0049] On this occasion, various kinds of inserts can be installed on the complex tool  21  according to the contents of machining since a plurality of numbers of inserts can be installed on the complex tool  21 . With each insert, turning machining or milling machining is performed. At this time, milling machining can be of course performed simultaneously using the plural numbers of inserts in addition to the machining referring to FIG. 6 or so, selectively using one insert of the plurality of inserts of the complex tool  21 .  
     [0050] When machining is performed on the outer periphery of the workpiece  17 , the machining to be considered are the turning machining on the outer periphery of the workpiece  17  with the insert  30  for instance, of the four inserts as shown in FIG. 10( a ) for instance, (The number of the inserts capable of installing on the complex tool  21  is not limited to four, but the complex tool  21  having four inserts provided at 90° pitch , similar to FIG. 4, will now be explained for simple explanation. Only two inserts  29 ,  30  located having phase difference of 180°, are shown in FIG. 10.), and milling machining on the workpiece simultaneously using the inserts  29 ,  30  as shown in FIG. 10( b ). As mentioned before, various machining is always performed using one or more inserts in the complex tool  21 . So, the tool data control portion  8  controls lifetime of each complex tool  21  as mentioned hereinafter.  
     [0051] That is, the tool data control portion  8  stores lifetime control file LCF concerning each complex tool  21  in the tool file  7  for every each insert, together with the tool data TL as shown in FIG. 7 or as a part thereof, as shown in FIG. 9.  
     [0052] In the lifetime control file LCF, indexing number KD in the complex tool  21  is adopted as the identification number corresponding to the insert installed on the complex tool  21  every tool number TN of each complex tool  21 . In the example of FIG. 9, the four inserts  22 ,  23 ,  25 ,  26  are installed on the complex tool  21  of FIG. 4 for instance at the pitch of 90°, and in order to show these installation positions, four indexing numbers are clockwise allotted with the axial center CT 3  of the tool as its center, as shown in FIG. 3( a ). Therefore, the respective inserts  22 ,  23 ,  25 ,  26  and the indexing numbers KD can be corresponded with one to one. In place of the indexing number KD, some marks for identifying the respective inserts can be also of course used.  
     [0053] In the lifetime control file LCF, normal lifetime LF of each insert is set in advance as lifetime, corresponding to the indexing number KD which is the identification mark of each insert. This normal lifetime LF may be input in advance through the keyboard  5  by an operator at the time of machining start, or may be online written in the lifetime control file LCF from a tool preset room separately provided from the complex machining machine tool  1 . When the machining to be performed by the complex tool  21  from now on is the machining for producing many of the same workpieces, the number of the workpieces capable of machining with the insert can be set in the shape of available number LN as the lifetime of the complex tool  21  in place of the normal lifetime LF. In this case, the machining time element to be integrated for judgement of lifetime is not used time UT of the insert, but the number of the workpieces machined. The value of this available number LN is obtained by dividing the time T 1  into the normal lifetime LF of the insert and cutting off its remainder if the machining time of one workpiece is T 1 . Then, the lifetime of the insert is within the normal lifetime LF although the predetermined number of workpieces are machined, and the number of the workpieces machined by the insert, that is, used number UN reaches the available number LN, so the workpiece is not machined by the insert exhausted. When the tool data control portion  8  simulates the machining program to be executed from now on and judges that the machining using only one insert of the complex tool  21  will be performed predetermined time T 1  as shown in FIG. 10( a ), for instance, the predetermined time T 1  is added to the used time UT of the insert, which is stored in the address of the indexing number KD where the insert to be used for machining is installed in the lifetime control file LCF, corresponding to the tool number TN of the complex tool  21  although the machining is turning machining, milling machining or drilling machining. For instance, in case of the machining of FIG. 10( a ), the predetermined time T 1  is added to the used time UT corresponding to the address which indexing number KD is 1, corresponding to the insert  30 . When the used time UT of the insert exceeds the normal lifetime LF set on the insert in advance, the tool data control portion  8  notifies an operator that the insert of the complex tool  21  reaches expiration of lifetime during the machining by giving alarm, and instructs to use spare tool or exchange the insert. Then, an operator knows before machining on the workpiece that at least one of the inserts of the complex tool  21  reaches expiration of lifetime in fact before reaching expiration of lifetime during the machining on the workpiece. Therefore, it is not necessary to interrupt the machining after the complex tool  21  reaches expiration of lifetime during the machining on the workpiece and to perform complex and inefficient operation, such as exchange of tool. In case where the lifetime of the insert is controlled by machining number, the tool data control portion  8  integrates one of the used number UN of the address of the indexing number ED corresponding to the insert of the lifetime control file LCF every time one workpiece is machined by the insert corresponding to the complex tool  21 . When the used number UN reaches the available number LN, the tool data control portion  8  notifies an operator of the expiration of the lifetime of the insert of the complex tool  21 , similar to the above-mentioned, and instructs to use a spare tool or to exchange the insert. In this case, the lifetime of the insert is controlled by the machining number. So, even if the used number UN becomes to be equal to the available number LN, the lifetime of the insert is maintained within the lifetime, as mentioned above.  
     [0054] When the tool data control portion  8  simulates the machining program to be executed from now on and judges that the machining simultaneously using two or more inserts  29 ,  30  of the complex tool  21  will be performed predetermined time T 1  as shown in FIG. 10( b ), for instance, the predetermined time T 1  is respectively added to the used times UT of these inserts, which are stored in the addresses of the indexing numbers KD where the inserts to be used for machining are installed (for instance, the indexing numbers KD are 1 and 3) in the lifetime control file LCF, corresponding to the tool number TN of the complex tool  21  although the machining is milling/fraise machining or drilling machining. For instance, in case of the machining of FIG. 10( b ), the predetermined time T 1  is respectively added to the used times UT corresponding to the addresses which indexing numbers KD are 1 and 3, corresponding to the inserts  29 ,  30  to be used at the same time.  
     [0055] When the used time UT of any insert of these inserts exceeds the normal lifetime LF set on the insert in advance, the tool data control portion  8  judges that the complex tool  21  reaches the expiration of the lifetime and notifies an operator that one or more inserts of the complex tool  21  reach expiration of lifetime during the machining by giving alarm, and instructs to use spare tool in place of the complex tool  21  or exchange the insert expected to be expiration of lifetime. Then, an operator knows before machining on the workpiece that at least one of the inserts of the complex tool  21  reaches expiration of lifetime in fact before reaching expiration of lifetime during the machining on the workpiece. Therefore, it is not necessary to interrupt the machining after the complex tool  21  reaches expiration of lifetime during the machining on the workpiece and to perform complex and inefficient operation, such as exchange of tool.  
     [0056] In case where machining is executed simultaneously using a plurality of inserts, the lifetime of each insert is integrated, respectively adding machining time to the used times UT of the inserts to be used for the machining. Therefore, the lifetime of every insert, comprising the complex tool  21 , can be correctly controlled, regardless of the machining contents to be executed by the complex tool  21 .  
     [0057] When lifetime is controlled by machining number in case where the machining using a plurality of inserts is executed, the used numbers UN of the indexing numbers KD corresponding to the inserts to be used with the complex tool  21  are respectively added by its machining number, and expiration of the lifetime of the complex tool  21  is judged when the added used number UN of one of the inserts of the complex tool  21  firstly reaches the available number LN, similar to the above-mentioned.  
     [0058] When the tool data control portion  8  judges that at least one of the inserts installed on a complex tool  21  reaches expiration of the lifetime, the complex tool  21  which lifetime reaches its expiration is exchanged into a spare complex tool  21 , and the machining is continued.  
     [0059] Besides, the complex tool  21  which lifetime reaches its expiration is transferred to a tool preset room or the like, and the insert which reaches expiration of the lifetime is exchanged into a new one and is used again for machining. Therefore, a plurality of inserts installed on the complex tool  21  is effectively used for machining till each insert reaches expiration of the lifetime. Then, such situation that the expiration of the lifetime of the complex tool is judged and all of the inserts installed on the complex tool  21  is thrown away although some inserts does not already reach the expiration of the lifetime is avoided.  
     [0060] The present invention is explained on the basis of the embodiment heretofore. The embodiments which are described in the present specification are illustrative and not limiting. The scope of the invention is designated by the accompanying claims and is not restricted by the descriptions of the specific embodiments. Accordingly, all the transformations and changes belonging to the claims are included in the scope of the present invention.