JP4153681B2 - Cutting tools - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cutting tool such as a throw-away tip used for cutting, and more particularly to a cutting tool with a wear sensor provided with a sensor line for detecting wear of a cutting edge.
[0002]
[Prior art]
Conventionally, methods for detecting the life of a cutting tool by utilizing thermal, mechanical, and electrical changes of the cutting tool have been studied. For example, in Japanese Patent Laid-Open No. 9-38846, a cutting tool in which a comb-shaped conductive band (thin film circuit) is formed on the surface of a base material is manufactured, and the electric resistance of the conductive band (thin film circuit) is cut while cutting the cutting tool. A method for determining tool life by measuring values is disclosed.
[0003]
Further, for example, in Japanese Patent Application Laid-Open No. 2001-121308, the applicant of the present application has principal surfaces 50 and 51 as shown in FIG. 5 ((a) a diagram viewed from the upper front side and (b) a diagram viewed from the lower front side). Has a polygonal shape, a plurality of flank surfaces 52 are formed, and a plurality of corner portions 53 intersecting the flank surfaces 52a and 52b adjacent to the main surfaces 50 and 51 are formed. A throw-away tip 56 in which sensor lines 55 and 55 'are formed in parallel along the cutting edges 54 and 54' in the vicinity of the corners 53 and 53 'so that 53 and 53' can be used as the cutting edges 54 and 54 '. Proposed. With this cutting tool, it is possible to accurately detect the wear width of the cutting blades 54 and 54 'with a simpler circuit pattern.
[0004]
Further, according to the same publication, both ends of the sensor line 55 of the corner portion 53 are connected to a pair of connection regions 57, 58 formed on the seating surface (the other main surface) 51, and the first, The sensor circuit 64 is formed by connecting to the connection line (side surface line) 63 drawn around the second and third connection lines 59, 60, 61 and the return line 62 arranged in parallel to the sensor line 55. Yes. Further, the corner portion 52 ′ where the two flank surfaces 52 a and 52 b adjacent to the corner portion 53 intersect the main surface 51 opposite to the main surface 50 includes a sensor line 54 ′, which is substantially the same as the sensor circuit 64. A sensor circuit 64 ′ having the same pattern is formed so as to be symmetric with respect to an intermediate point between the corner portions 53 and 53 ′, and the folding lines 62 and 62 ′ are parallel to the cutting edges 54 and 54 ′, respectively. The pattern was formed in parallel.
[0005]
[Problems to be solved by the invention]
However, in the throw away tip 56 of JP 2001-121308 A, when a large amount of chips collide with the flank 52 in a cutting process in which a large amount of chips are generated, such as steel turning, the impact is generated. As a result, the connection line (side surface line) 63 such as the folding line 62 formed on the flank 52 may be damaged, possibly resulting in disconnection, and accurate tool life may not be detected.
[0006]
The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a cutting tool capable of preventing the sensor circuit from being damaged by chips during cutting and accurately detecting the tool life. .
[0007]
[Means for Solving the Problems]
As a result of examining the routing of a sensor circuit of a cutting tool having a plurality of cutting blades and sensor circuits for the above problems, the present inventors have shared some of the connection lines of the plurality of sensor circuits. As a result of increasing the line width of connection lines such as side lines located in areas that are particularly susceptible to chips, and increasing the degree of freedom in line design, it is simple and can be damaged by the effects of chips. It was found that a cutting tool having a sensor circuit that is hardly received can be manufactured, and the tool life can be accurately detected.
[0008]
In other words, the cutting tool of the present invention removes the influence of chips and reliably increases the tool life in cutting operations in which an accurate tool life cannot be detected because the sensor circuit is disconnected due to the influence of the chips. The purpose is to detect.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
1 is a schematic perspective view of an example of a throw-away tip that is a preferred example of the cutting tool of the present invention, based on FIG. 1 ((a) a perspective view seen from the front upper side, (b) a perspective view seen from the lower front side). explain.
[0010]
According to FIG. 1, the throw-away tip 1 has a rake face 3 on one principal surface of a base material 2 having a substantially flat plate shape (substantially rectangular parallelepiped shape in FIG. 1), a seating surface 4 on the other principal surface, and a side surface. The flank 5 (5a, 5b) is formed, and the intersecting ridge portion between the rake face 3 and the flank 5, particularly the main surfaces (3, 4) as shown in FIG. In the case where it consists of, the cutting edge 7 is formed in the corner part 6 where the rake face 3 and two adjacent flank faces 5 (5a, 5b) intersect.
[0011]
Further, according to FIG. 1, a sensor line 8 (8 </ b> A) having a predetermined width made of a conductive band is provided in parallel with the cutting edge 7 in the vicinity of the cutting edge 7 of the flank 5. The allowable wear width of the tool life (wear amount) can be defined by the position and width.
[0012]
Further, the sensor line 8 is connected to the first and second pair of connection regions 11 and 12 formed on the seating surface 4 via the connection line 9 (19 (19a, 19b, 19c)). The sensor circuit 10 is formed by the connection line 9 and the connection regions 11 and 12.
[0013]
For example, the position of the inner end portion 8a of the flank 5 of the sensor line 8 is matched with the life reference amount of the cutting blade 7 (wear limit width of the cutting blade 7), for example, 0.05 to 0.7 mm. When cutting is performed with the cutting blade 7, at least a part of the sensor line 8 formed in the vicinity of the cutting blade 7 is disconnected due to damage such as wear, that is, between the sensor lines 8, that is, the sensor circuit 10. Is disconnected, and the lifetime of the cutting edge 7 can be detected by measuring the resistance value between the first and second connection regions 11 and 12 formed at both ends of the sensor circuit 10.
[0014]
Moreover, according to FIG. 1, since the 1st and 2nd connection area | regions 11 and 12 are formed in the seating surface 4, a pair of formed in the chip seat 23 of the below-mentioned chip holder 21 which the seating surface 4 touches. The first and second connection regions 11 and 12 of the sensor circuit 10 can be easily connected to the external circuits 27a and 27b.
[0015]
On the other hand, according to FIG. 1, the connecting line 9 has a first connecting line 13 connecting the first connecting region 11 and the sensor line 8, and the thickness direction of the flank 5 with a predetermined distance from the sensor line 8. , A second connection line 15 that connects the sensor line 8 and the return line 14, and a second connection line 15 that connects the return line 14 and the second connection region 12. 3, i.e., the sensor circuit 10 includes a first connection region 11-a first connection line 13-a sensor line 8-a second connection line 15-a folded line. 14 through the third connection line 16 and the second connection region 12.
[0016]
The sensor circuit 10 is provided in an insulated state with respect to the base material 2, and the sensor circuit 10 is formed of a conductor having a predetermined electric resistance value.
[0017]
Further, according to FIG. 1, the corner portions 6B where the flank surfaces 5a and 5b adjacent to the corner portion 6A and the main surface (sitting surface) 4 opposite to the main surface (rake surface) 3 intersect, that is, each other A first sensor circuit 10 and a second sensor circuit 17 having substantially the same configuration in which sensor lines 8A and 8B are disposed at two corner portions 6A and 6B facing each other with the folding line 14 interposed therebetween are formed. . Note that, according to FIG. 1, the first sensor circuit 10 and the second sensor circuit 17 are formed so as to be symmetric with respect to an intermediate point between the corner portions 6A and 6B.
[0018]
According to the present invention, a part of the connection line 9 connected to the sensor line 8A of the first sensor circuit 10 and a connection line 19 (19a, 19b, connected to the sensor line 8B of the second sensor circuit 17 are provided. 19c) is partly shared, which makes it possible to increase the line width of connection lines located in areas that are particularly susceptible to chips and to increase the degree of freedom in line design. As a result, a cutting tool that is simple and hardly damaged by the influence of chips can be produced, and the tool life can be detected accurately.
[0019]
According to FIG. 1, the second connection line 15 of the first sensor circuit 10, the third connection line 16 ′ of the second sensor circuit 17 (the first shared line 19a in FIG. 1), the first 1 and the second sensor circuit 17 and the second sensor circuit 17 are folded lines 14 '(the common line 19b in FIG. 1), and the third connection line 16 and the second sensor circuit of the first sensor circuit 10. 17 second connection lines 15 '(shared line 19c in FIG. 1) are shared.
[0020]
Further, according to FIG. 1, at least one of the connecting lines 9 and 19 (19a, 19b, and 19c) is formed on the flank 5 that has a narrow line width and is easily broken due to the influence of chips generated during cutting. Part, in particular, the folding line 14 is shared, so that the line width of the connection lines 9 and 18 located on the flank 5 can be widened and the line can be easily removed. Disconnection of the sensor circuits 10 and 17 can be prevented.
[0021]
Further, according to FIG. 1, the first and second connection regions 11 and 12 are formed adjacent to each other, which facilitates positioning of the external terminals connected to the pair of connection regions 11 and 12. And the wiring inside the holder can be easily handled.
[0022]
Further, according to the present invention, particularly in a cutting tool that can be attached and detached, such as a throw-away tip, the cutting edge 7 is formed in each corner portion 6 (6A, 6B) of both main surfaces, and the sensor line 8 (8A, 8B) is arranged in the vicinity of each cutting edge 7 one by one.
[0023]
That is, as shown in FIG. 1, the main surface of the base material 2 has a polygonal shape (quadrangle in FIG. 1), and a plurality of flank surfaces 5 (four in FIG. 1) are formed and adjacent to the main surface 2. When the corner portions 6 (6A) intersecting the two flank surfaces 5a and 5b are provided, it is desirable to form the sensor lines 8 in the respective corner portions 6 (eight in FIG. 1). Depending on the method of use, cutting can be performed using the eight corner portions 6.
[0024]
In addition, according to FIG. 1, the 1st connection line 13 and the 2nd connection line 15 which were formed in the flank 5 are the arrangement position of the 1st and 2nd connection area | regions 11 and 12 of the sensor circuit 10, and The positions of the first and second connection regions 11 ′ and 12 ′ of the other sensor circuit 17 on the opposite surface of the first and second connection regions 11 and 12 of the sensor circuit 10 are the same positions on the main surface. 2 so as to be connected to the same external terminal 27 (27a, 27b) of the chip holder 21 of FIG. It is arrange | positioned so that it may have a predetermined inclination angle instead of an orthogonal direction.
[0025]
Further, according to the present invention, the shape of the throw-away tip 1 is not limited to a square main surface (rake face 3 and seating face 4) as shown in FIG. Other regular polygons such as triangles, parallelograms, rhombuses and the like are applicable, and the cross-sectional shape of the throw-away tip 1 is not limited to a rectangle, but may be a trapezoidal shape.
[0026]
(Installation example)
Further, according to FIG. 1, a clamp hole 20 penetrating the base material 2 is formed in the center of the base material 2, which is an example in which the throw-away tip 1 of FIG. 1 is attached to the tip holder 21. As shown, the throw-away tip 1 is attached to the tip holder 21 or the like by a clamp screw 25 being screwed into the clamp hole 20 or being pressed from the rake face 3 side by a metal fitting (not shown). Is done.
[0027]
Further, according to FIG. 2, a tip mounting pocket 22 is formed at the tip of the tip holder 21. The bottom surface of the pocket 22 is a chip seat 23. Further, the side surface of the pocket 22 is in contact with the side surface of the chip and serves as a restraining surface 24 for restraining the chip. The throw-away tip 1 is stored in the pocket 22, the seating surface 4 is brought into contact with the tip seat 23, and the side surface of the throw-away tip 1 is brought into contact with the restraint surface 24. The clamp screw 25 is inserted into the clamp hole 20 of the throw-away tip 1 from above, and the tip thereof is screwed into the screw hole 26 formed in the center of the tip seat 23, whereby the throw-away tip 1 is inserted into the tip holder 21. It is attached to.
[0028]
Further, the tip seat 23 is located at a position facing the first and second connection regions 11 and 12 connected to the sensor line 8 provided at the corner portion used for cutting the attached throw-away tip 1. For example, a pair of external terminals 27 a and 27 b that are elastically biased upward and protrude from the chip seat 23 by several mm are provided. When the throw-away tip 1 is mounted in the pocket 22, the external terminals 27 a and 27 b are pushed down by the seating surface 4 of the throw-away tip 1, and the upper ends of the external terminals 27 a and 27 b are flush with the tip seat 23. At this time, the upper ends of the external terminals 27a and 27b are in electrical contact with the first and second connection regions 11 and 12 provided on the seating surface 4 of the throw-away tip 1, respectively.
[0029]
Further, according to FIG. 2, the lead wires 28 laid in the chip holder 21 are connected to the external terminals 27a and 27b, and the lead wires 28 are connected to a resistance value detection circuit 29 such as an ohmmeter. Thus, the resistance value of the sensor line 8 provided on the cutting edge 7 (corner portion 6 used for cutting) of the throw-away tip 1 mounted in the pocket 22 can be measured.
[0030]
In the mounted state of FIG. 2, for example, the cutting edge 7 of the corner portion 6A of the throw-away tip 1 is used for cutting. When the cutting edge 7 of the corner portion 6A is worn, the clamp screw 25 and the holding fitting are loosened, the throwaway tip 1 is rotated by 90 ° around the center of the rake face 3, and the corner portion 6A Another adjacent corner portion 6 can be used as a cutting edge 7 for cutting. In this way, the throw-away tip 1 can be rotated by 90 °, and the four corners on one main surface side of the throw-away tip 1 can be sequentially used for cutting. Furthermore, if the throw-away tip 1 is turned upside down and mounted on a holder or the like, the four corner portions of the other main surface can be used for cutting sequentially, and a total of eight corner portions 6 can be used. . In addition, when using the corner part of the other main surface, a rake surface and a seating surface function in reverse.
[0031]
(Second Embodiment)
Further, in the throw-away tip 1 of FIG. 1, the folding line 14 is sandwiched between corner portions 6A and 6B where both main surfaces (rake surface 3 and seating surface 4) and two adjacent flank surfaces 5a and 5b intersect. The connection lines 9 and 19 (19a, 19b and 19c) between the two sensor circuits 10 and 17 provided with the sensor lines 8A and 8B so as to face each other are shared with each other. However, the present invention is not limited to this, as shown in the schematic diagrams of the second embodiment of the present invention shown in FIG. 3 ((a) perspective view seen from the front upper side, (b) view seen from the lower front side). The sensor lines 8A and 8C of the first sensor circuit 30 and the second sensor circuit 31 are connected to two of the flank faces adjacent to the rake face 3 (5a and 5b, 5b and 5c in FIG. 3). In the intersecting corners 6A, 6C The first connection lines 33A of the first sensor circuit 30 and the first connection lines 33C of the second sensor circuit 31 are shared with each other so as to be positioned on the diagonal lines of the flank 5 (in FIG. 3). , Described as a shared line 34).
[0032]
This also makes it possible to increase the line width of the connection lines (first connection lines) 33A and 33C located on the flank 5 and to facilitate the line removal. As a result, the sensor circuit 30 due to the influence of chips, The disconnection of 31 can be prevented.
[0033]
(Third embodiment)
Furthermore, according to the present invention, in addition to the wiring pattern described above, a part of the connection line may be formed on a surface other than the flank (rake surface or seating surface). Therefore, an outline of the third embodiment of the present invention is shown in FIG. 4 ((a) a perspective view seen from the front upper side, (b) a view seen from the lower front side). According to FIG. 4, the sensor lines 8 </ b> A and 8 </ b> C of the first sensor circuit 40 and the second sensor circuit 41 are arranged at two corner portions 6 </ b> A and 6 </ b> C that are located on the diagonal line of the flank 5. In addition, the fold line 42 is not formed on the flank 5 as in the fold line 14 of the first and second embodiments described above, but is formed on the rake face 3, and the first sensor circuit 40 of the first sensor circuit 40. The third connection line 16 </ b> A and the third connection line 16 </ b> C of the second sensor circuit 41 may be shared (indicated as a shared line 43 in FIG. 4).
[0034]
This also makes it possible to increase the line width of the connection lines 16A and 16C located on the flank 5 and to facilitate line cutting, thereby preventing disconnection of the sensor circuits 40 and 41 due to the influence of chips. Can do.
[0035]
Further, according to the embodiment of FIG. 4, the connection line 42 (corresponding to the connection line 9 of FIG. 1) is not formed in the vicinity of the region where the adjacent flank surfaces 5 a and 5 b that are easily affected by the chips intersect. Less susceptible to chips.
[0036]
Furthermore, according to FIG. 4, the folding line 42 constituting the first sensor circuit 40 also serves as the second connection region 12 </ b> C of the second sensor circuit 41, whereby the sensor circuit on the rake face 3. There is an advantage that the shape can be further simplified and damage to the folding line 42 can be prevented.
[0037]
(Material)
As a base material of the throw-away tip 1 shown in FIG. 1, an alumina sintered body, a silicon nitride sintered body, a cermet, a cemented carbide, a cubic boron nitride sintered body (CBN / cubic Boron Nitride), diamond A sintered body (PCD / Polycrystalline Diamond) or the like can be suitably used.
[0038]
On the other hand, the sensor circuits 10 and 17 such as the sensor line 8 and the connection lines (first and second connection regions 11 and 12, first, second and third connection lines 13, 15, 16 and turn-back line 14) are provided. The conductive band to be formed has a strong bonding force to the base material 2 of the throw-away tip 1, does not react with the work material, the electric resistance value of the sensor line 8 always shows a predetermined value, and the degree of wear of the throw-away tip 1 The presence or absence of defects can be accurately detected, reaction products are less likely to be generated on the work surface of the work material, the oxidation resistance is excellent, and the electrical resistance value of the sensor line 8 changes due to oxide formation. 4a, 5a, such as Ti, Zr, V, Nb, Ta, Cr, Mo, W, etc. for the reason that it is possible to accurately detect the degree of wear of the throw-away tip 1 and the presence or absence of occurrence of defects. a group metal, Co, Ni, iron group metals such as Fe or a metal material and TiC, such Al,, VC, NbC, TaC , Cr 3 C 2, Mo 2 C, WC, W 2 C, TiN, VN, NbN , TaN, CrN, TiCN, VCN, NbCN, TaCN, CrCN, etc., 4a, 5a, 6a group metal carbide, nitride, carbonitride, at least one selected from the group of (Ti, Al) N, especially TiN , (Ti, Al) N, (Ti, Al) CN, and at least one selected from the group of (Ti, Al) CN, and TiN are preferred.
[0039]
(Production method)
In order to form the sensor circuits 10 and 17, for example, a CVD method, ion plating, sputtering, vapor deposition or the like is performed on almost the entire surface of the base material 2 produced by molding and firing predetermined ceramic powder. After depositing and forming a conductive film of 0.05 to 20 μm by a known thin film forming method such as PVD method, plating method, etc. in terms of controlling to a predetermined thickness, particularly adhesion to the base material 2 and a predetermined resistance value Then, the sensor circuits 10 and 17 having a predetermined pattern are processed by laser processing, blast processing using a mask, cutting processing using a drill, or the like.
[0040]
As a method for forming the sensor circuits 10 and 17 by processing, the conductive thin film deposited on the surface of the base material 2 is finely performed by laser processing such as YAG laser or CO ₂ laser irradiation scanning. This is desirable because it is easy to process. For example, when a YAG laser having a wavelength of 1.06 μm is used, irradiation scanning is performed at an output of 5 to 35 kHz, 8.0 to 20.0 A, a width of 40 to 60 μm, and a drawing speed of 10 to 300 mm / s.
[0041]
Furthermore, when the base material 2 is an insulator such as an alumina sintered body, a silicon nitride based sintered body, or cBN, the sensor circuits 10 and 17 can be directly formed on the surface of the sensor circuit 10 or 17. Is a conductor such as cemented carbide or cermet, it is desirable to form an intermediate layer made of an insulator such as alumina on the surface of the base material 2. The intermediate layer is desirably formed with a thickness of 1 to 10 μm using a known thin film forming method such as a PVD method or a CVD method in order to ensure insulation and prevent peeling of the intermediate layer.
[0042]
【The invention's effect】
Or as detailed, according to the cutting tool of the present invention, or thickening the line width of the connection line located in the particular cutting susceptible areas the influence of the debris, the results can be to increase the degree of freedom of the line design, simple In addition, it is possible to produce a cutting tool that is hardly damaged by the influence of chips, and to accurately detect the tool life.
[Brief description of the drawings]
FIG. 1A is a perspective view of a first embodiment of a cutting tool according to the present invention as viewed from the front upper side of a throw-away tip as a preferred example thereof, and FIG.
FIG. 2 is an exploded perspective view for explaining an example of a method for attaching the throw-away tip of FIG. 1 to a tip holder.
FIGS. 3A and 3B are a perspective view of the second embodiment of the cutting tool according to the present invention as viewed from the front upper side of the throw-away tip as a preferred example, and FIG.
4A is a perspective view of a second embodiment of the cutting tool according to the present invention as viewed from the front upper side of the throw-away tip as a preferred example thereof, and FIG. 4B is a perspective view viewed from the lower front side.
5A is a perspective view of a conventional throw-away tip as viewed from the upper front side, and FIG. 5B is a perspective view of the conventional throw-away tip as viewed from the lower front side.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Throw away tip 2 Base material 3 Rake face 4 Seating surface 5 (5a, 5b) Flank 6 Corner part 7 Cutting edge 8 Sensor line 8a Inner edge part 9, 18 Connection line 10, 17 Sensor circuit 11 1st connection area 12 Second connection region 13 First connection line 14 Folded line 15 Second connection line 16 Third connection line 19 Shared line 20 Clamp hole 21 Chip holder 22 Pocket 23 Chip seat 24 Restraint surface 25 Clamp screw 26 Screw hole 27 External terminal 28 Lead wire 29 Detection circuit

Claims (4)

A rake face on one of the main surfaces of the base material having a substantially flat plate shape, a seating surface on the other main surface, a flank surface on the side surface, and a cross ridge portion between the rake surface and the flank surface as a cutting edge And a sensor line made of a conductive band disposed near the cutting edge of the flank, a first and second pair of connection regions disposed on the seating surface, the first connection region and the A plurality of sensor circuits each including a sensor line and a connection line connecting the sensor line and the second connection region; and at least a first sensor circuit of the plurality of sensor circuits. A common line that shares a part of the connection line of the second sensor circuit and a part of the connection line of the second sensor circuit is formed on the flank, the main surface of the base material has a polygonal shape, and a plurality of the flank Two formed and adjacent to the main surface A plurality of corner portions intersecting with the flank, and the connection line is parallel to the first connection line connecting the first connection region and the sensor line with the sensor line at a predetermined interval. A folding line formed on the center side in the thickness direction of the flank, a second connection line connecting the sensor line and the folding line, and the folding line and the second connection region. The first sensor circuit and the second sensor circuit are formed with substantially the same configuration so as to include a third connection line that connects between the first sensor circuit and the second sensor circuit. Each of the sensor lines of the sensor circuit is provided at each of the two corner portions facing each other across the folded line,
The shared line includes a second connection line of the first sensor circuit, a third connection line of the second sensor circuit, a folded line of the first sensor circuit, and a second sensor circuit. A cutting tool characterized by sharing a folding line and the third connection line of the first sensor circuit and the second connection line of the second sensor circuit . A rake face on one of the main surfaces of the base material having a substantially flat plate shape, a seating surface on the other main surface, a flank surface on the side surface, and a cross ridge portion between the rake surface and the flank surface as a cutting edge And a sensor line made of a conductive band disposed near the cutting edge of the flank, a first and second pair of connection regions disposed on the seating surface, the first connection region and the A plurality of sensor circuits each including a sensor line and a connection line connecting the sensor line and the second connection region; and at least a first sensor circuit of the plurality of sensor circuits. A common line that shares a part of the connection line of the second sensor circuit and a part of the connection line of the second sensor circuit is formed on the flank, the main surface of the base material has a polygonal shape, and a plurality of the flank Two formed and adjacent to the main surface A plurality of corner portions intersecting the flank face, and the connection line is parallel to the first connection line connecting the one connection region and the sensor line with the sensor line at a predetermined interval. A folding line formed on the center side in the thickness direction of the flank, a second connection line connecting between the sensor line and the folding line, and between the folding line and the other connection region. The first sensor circuit and the second sensor circuit are formed with substantially the same configuration so as to include a third connection line to be connected, and the first sensor circuit and the second sensor The sensor lines of the circuit are respectively provided at the two corner portions positioned on the diagonal line of the flank,
The shared tool shares the first connection line of the first sensor circuit and the first connection line of the second sensor circuit. A rake face on one of the main surfaces of the base material having a substantially flat plate shape, a seating surface on the other main surface, a flank surface on the side surface, and a cross ridge portion between the rake surface and the flank surface as a cutting edge And a sensor line made of a conductive band disposed near the cutting edge of the flank, a first and second pair of connection regions disposed on the seating surface, the first connection region and the A plurality of sensor circuits each including a sensor line and a connection line connecting the sensor line and the second connection region; and at least a first sensor circuit of the plurality of sensor circuits. A common line that shares a part of the connection line of the second sensor circuit and a part of the connection line of the second sensor circuit is formed on the flank, the main surface of the base material has a polygonal shape, and a plurality of the flank Two formed and adjacent to the main surface A plurality of corner portions intersecting with the flank face, and the connection line is a first connection line connecting between the one connection region and the sensor line, and a folding line formed on the rake face And a second connection line connecting between the sensor line and the return line, and a third connection line connecting between the return line and the other connection region. The first sensor circuit and the second sensor circuit are formed with substantially the same configuration, and the sensor lines of the first sensor circuit and the second sensor circuit are positioned on a diagonal line of the flank. Provided in each of the two corner portions, and the shared line shares the third connection line of the first sensor circuit and the third connection line of the second sensor circuit. A cutting tool to be. 4. The cutting tool according to claim 3 , wherein the folding line constituting the first sensor circuit also serves as one of the connection regions of the second sensor circuit. 5.

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