JP2003191105A - Cutting tool with wear sensor circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool having a stable wear sensor circuit preventing separation from a matrix and a severance of wire of the sensor circuit (a conductive line) even by cutting in harsh conditions such as appliance of large impact, generation of high cutting heat, and production of a great deal of chips. <P>SOLUTION: In the cutting tool 1 with the wear sensor circuit, the sensor circuit 13 is disposed, formed with a recessed part 10 in a matrix 2 surface with a conductor 12 embedded in the recessed part 10, a continuity state of the sensor circuit 13 is monitored, and a worn state of a cutting edge 9 is detected. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool used for cutting, and more particularly to a cutting tool provided with a sensor line for detecting wear of a cutting edge.

[0002]

2. Description of the Related Art Conventionally, a method of detecting the life of a cutting tool by utilizing thermal, mechanical and electrical changes of the cutting tool has been studied. For example, in Japanese Unexamined Patent Publication No. 2000-94272, a throw-away tip in which a sensor line (thin film circuit) having a constant width is formed along a cutting edge portion of a flank on a surface of a base material is manufactured, and a work material is cut with the tip. A method of determining the tool life by measuring the electrical resistance of a sensor line while cutting is disclosed. According to the publication, as a method of forming a sensor circuit including a sensor line, a method of forming a conductive film on the surface of a base material by a thin film forming method and then processing the sensor circuit pattern by laser processing is described. .

Further, in Japanese Patent Laid-Open No. S62-88552, a surface of a chip base material is covered with an insulating layer and a conductive film by a thin film forming method such as a PVD method or a CVD method, and a conductor path (sensor circuit) is formed by etching. After that, a method of burying the sensor circuit (conductive path) in the chip by further providing a second insulating layer on the surface of the sensor circuit by the same thin film forming method is described.

[0004]

However, as disclosed in the above-mentioned Japanese Patent Laid-Open No. 2000-94272, a sensor circuit (conductive path) is formed by coating a conductive film by a thin film forming method and etching it.
In the method of forming, inevitably the height of the sensor circuit forming portion becomes higher than other portions, chips collide with the sensor circuit first, or the cutting heat generated during cutting is repeatedly applied, There is a problem that the sensor circuit is peeled off or worn, or cracks are generated in the sensor circuit to break the circuit.

Also, according to the method of embedding the sensor circuit disclosed in JP-A-62-88552, as shown in FIG. 4, by forming the sensor circuit 50, the surface roughness of the chip surface 51 is deteriorated and the chip surface is deteriorated. There was a risk that chattering would occur during cutting because the seating and fixing were poor. Further, in such a method, there is a possibility that an operator cannot visually check the sensor circuit pattern visually, so that there is a possibility that a wrong chip or a wrong mounting position may occur.

The present invention has been made in order to solve the above-mentioned problems, and its purpose is to meet the harsh conditions that a large impact is applied, a high cutting heat is generated, and a large amount of chips are generated. An object of the present invention is to provide a cutting tool that has a stable wear sensor circuit in which the sensor circuit (conductive path) does not peel off from the base material or is not broken even by the cutting described in (1) and can perform stable cutting.

[0007]

As a result of studying the structure of a sensor circuit for the above problems, the present inventor has found that the sensor circuit has a structure in which a conductor is embedded in a concave portion formed on the surface of a base material, so that a shock is generated. It has been found that the cutting tool is provided with a stable sensor circuit that does not cause peeling or disconnection of the sensor circuit even with repeated heat cycles or chips and maintains the smoothness of the chip surface.

That is, in the cutting tool of the present invention, a concave portion is formed on the surface of a base material, and a sensor circuit having a conductor embedded in the concave portion is arranged, and the cutting edge is monitored by monitoring the conduction state of the sensor circuit. It is characterized by detecting the wear state of the.

Here, a group of at least one carbide, nitride, carbonitride, Al ₂ O ₃ , diamond and DLC of at least one metal of Groups 4a, 5a and 6a of the periodic table is formed on the surface of the base material and the sensor circuit. At least one coating layer selected from the above may be formed to a thickness of 50 μm or less, and it is preferable that the unevenness of the surface of the cutting tool is 100 μm or less.

Further, it is preferable that the base material is made of a conductive material, and an insulating film is interposed between the base material and the conductor.

Furthermore, it is desirable that the corners of the recess be R-shaped.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An example of a throw-away tip which is a preferred example of the cutting tool of the present invention will be described with reference to FIG. 1 which is a schematic perspective view thereof.

According to FIG. 1, the throw-away tip 1 is shown.
Is a base material 2 having a substantially flat plate shape (a substantially rectangular parallelepiped shape in FIG. 1)
The rake face 5 on one main surface and the seating surface 6 on the other main surface,
The flank 7 is formed on the side surface, and when the ridge portion where the rake face 5 and the flank 7 intersect, especially when the main surface as shown in FIG. 1 has a polygonal shape, the flank 7 is composed of a plurality of flat surfaces. A cutting edge 9 is provided at a corner portion 8 where 5 and two flanks 7 adjacent to each other intersect.
Are formed.

According to the present invention, the throw-away tip 1
On the other hand, as shown in FIG.
Is characterized in that the sensor circuit 13 having the conductor 12 embedded in the recess 10 is formed, and the wear state of the cutting edge can be detected by monitoring the conduction state of the sensor circuit 13. You can

According to the present invention, in order to improve the fracture resistance of the base material 2, the width w of the recess 10 is 0.1 to 5 m.
m, particularly 0.2 to 1 mm, thickness t is 5 to 1000 μm,
In particular, it is preferable that the shape is a substantially rectangular parallelepiped shape of 20 to 200 μm, and the corner portions A on the surface and the bottom surface are R-shaped.

Here, according to the present invention, when the base material 2 has conductivity, the insulating layer 1 is provided between the base material 2 and the conductor 12.
It is necessary to interpose 4. The insulating layer is preferably formed to have a thickness of 1 to 10 μm in order to ensure insulation and prevent peeling.

Further, according to the present invention, a hard coating layer may be provided on the surface of the sensor circuit 13 for the purpose of protecting the sensor circuit 13, but according to the present invention, the sensor circuit 13 is provided.
Since it is embedded in the base material 2 and the possibility of disconnection is low, it can be used sufficiently without forming the hard coating layer on the surface of the sensor circuit 13. When disposing the hard coating layer, the material of the hard coating layer is
From the group of carbides, nitrides, carbonitrides, Al ₂ O ₃ , diamond and DLC of at least one metal of Groups 4a, 5a and 6a of the Periodic Table in order to improve the protection and wear resistance of the sensor circuit. At least one selected, especially Ti
C, TiCN, TiN, TiAlN, Al ₂ O ₃ is desirable, but the total thickness of the hard coating layer is 50 μm or less, especially 2 because the sensor circuit pattern can be visually confirmed.
It is preferably 0 μm or less, more preferably 10 μm or less.

According to the present invention, the unevenness of the surface of the throw-away tip 1 is particularly 100 μm or less, as compared with the conventional throw-away tip with a sensor circuit in which the sensor circuit is formed on the surface of the flat base material. Since it is as smooth as 50 μm or less, the seating surface 6 of the chip 1 can be comfortably seated, the chip 1 can be restrained in a good condition, and chattering during cutting can be suppressed. Even when the hard coating layer is provided, unevenness formed by forming the sensor circuit does not cause coating unevenness, and a hard coating layer having a uniform thickness variation of 20% or less of the thickness (average) of the hard coating layer can be formed. it can.

Further, according to the present invention, ease of manufacture,
Depending on the accuracy of the sensor circuit 13, it is not necessary for all of the sensor circuit 13 to have a structure in which a conductor is embedded in the recess, and only a part thereof, particularly only the rake face 5 and the seating face 6, or only the flank face 7. Alternatively, the conductor may be embedded in the recess, and the sensor circuit may be adhered to the surface of the base material which is otherwise flat. For example, if two recesses are formed at the upper and lower ends of the flank 7 and that surround the outer circumference, and conductors described below are embedded in the recesses, the sensor line can be easily formed without arranging the chip 1. .

On the other hand, as the pattern of the sensor circuit 13, for example, as shown in FIG. 1, the sensor line 1 formed of a conductive band in the vicinity of the cutting edge 9 of the flank 7 and parallel to the cutting edge 9 is parallel.
5 is provided, and the allowable wear width of the tool life (amount of wear) can be defined by the formation position and width of the sensor line 15.

Further, the sensor line 15 is connected to the connecting portion 27 of the connecting line 17 formed on the surface of the throw-away tip 1, and the sensor line 15 and the connecting line 17 form the sensor circuit 13.

Then, for example, the position of the sensor line 15 is made to coincide with the life reference amount of the cutting edge 9 (wear limit width of the cutting edge 9), for example, 0.05 to 0.7 mm, and the cutting edge 9 is used. By performing the cutting process, when at least a part of the sensor line 15 formed in the vicinity of the cutting edge 9 is disconnected due to damage such as wear, the sensor lines 15 are disconnected, that is, the sensor circuit 13 is disconnected, and the sensor A pair of connection terminals 20, 20 (20 ', 20') formed at both ends of the circuit 13.
The life of the cutting edge 9 can be detected by measuring the resistance value between them.

On the other hand, according to FIG. 1, a pair of connection terminals 2
0, 20 (20 ′, 20 ′) are formed on the seating surface 6, whereby a pair of external circuits 3 formed on a chip holder 30 (described later) that contacts the sensor circuit 13 with the seating surface 6 is formed.
6 and 36 can be easily connected.

Further, according to FIG. 1, one connection terminal 20
Between the sensor line 15 and the side surface of the base material 2 (flank surface 7)
Connected via a first side line 24 formed in
The other end of the sensor line 15 is connected to the folding line 26 formed on the flank 7 via the connecting portion 27 (12b), and the folding line 26 and the other connecting terminal 2 are connected.
It is connected to 0 through a second side surface line 28 formed on the flank 7 (side surface). That is, according to FIG. 1, the sensor circuit 13 includes the first connection terminal 20-the first side surface line 24-the connection portion 27a-the sensor line 15-the connection portion 27b-the folded line 26-the second side surface line 28.
Via the second connection terminal 20. The sensor circuit 13 is provided in a state of being insulated from the base material 2, and the sensor circuit 13 itself is made of a conductor having a predetermined electric resistance value.

Further, according to FIG. 1, a pair of connection terminals 2
0 and 20 are formed adjacent to each other, which facilitates the positioning of the external terminals connected to the pair of connection regions.

Further, according to FIG. 1, particularly in a cutting tool in which a throw-away tip or the like can be attached and detached, a cutting edge 9 is formed in each corner portion 8 of both main surfaces, and a sensor line 15 is provided in each cutting edge 9. They are arranged one by one in the vicinity.

That is, as shown in FIG. 1, the main surface of the base material 2 has a polygonal shape (quadrangle in FIG. 1), a plurality of flanks 7 (four in FIG. 1) are formed, and the main surface 2 and When there are corners 8 where two adjacent flanks 7 intersect, it is desirable to form the sensor lines 15 at each corner 8 (eight in FIG. 1), whereby the method of use described later will be described. Thus, the cutting process can be performed by using the eight corner portions 8 in order.

According to FIG. 1, the first side surface line 24 and the second side surface line 28 formed on the flank 7 are shown.
Is mainly the arrangement position of the connection terminals 20 and 20 of the sensor circuit 13 and the arrangement position of the connection terminals 20 ′ and 20 ′ of the other sensor circuit 13 ′ on the surface opposite to the connection terminals 20 and 20 of the sensor circuit 13. With respect to the sensor line 15 (in other words, with respect to the cutting edge 9), so that they can be connected to the same external terminal 36 of the chip holder 30 of FIG. It is arranged so as to have a predetermined inclination angle instead of the orthogonal direction.

Further, according to the present invention, the shape of the throw-away tip 1 is not limited to a square main surface (the rake surface 5 and the seating surface 6) as shown in FIG. Shapes, other regular polygons such as regular triangles, parallelograms, diamonds, etc. are applicable, and the cross-sectional shape of the throw-away tip 1 is not limited to a rectangle, and may be a trapezoidal shape. . In addition to the shapes described above,
The present invention can also be applied to grooving chips and the like.

Further, according to FIG. 1, a clamp hole 29 penetrating the base material 2 is formed in the center of the base material 2, and the throw-away tip 1 of FIG.
As shown in the example of FIG. 3 attached to the insert, the throw-away tip 1 has the clamp screw 34 screwed into the clamp hole 29, or a rake face 5 with a metal fitting (not shown).
By being pressed from the side, the chip holder 30 or the like is mounted.

Further, according to FIG. 3, a tip mounting pocket 31 is formed at the tip of the tip holder 30. The bottom surface of the pocket 31 is a chip seat 32.
The side surface of the pocket 31 is in contact with the side surface of the chip and serves as a restraining surface 33 for restraining the chip. The throw-away tip 1 is stored in this pocket 31, the seating surface 6 is the tip seat 32, and the side surface of the tip 21 is the restraining surface 3.
3 is abutted. Then, the clamp screw 34 is inserted into the clamp hole 29 of the throw-away tip 1 from above, and the tip of the clamp screw 34 is screwed into the screw hole 35 formed in the center of the tip seat 32. Be attached to.

Further, on the tip seat 32, for example, at a position facing one of the connection terminals 20, 20 connected to the sensor line 15 provided in the corner portion used for cutting the attached throw-away tip 1, for example, A pair of external terminals 36, 36 that are elastically urged upward and project a few mm from the tip seat 32 are provided. Then, when the throw-away tip 1 is mounted in the pocket 31, the external terminals 36, 36 are pushed down by the seating surface 6 of the throw-away tip 1, and the upper ends of the external terminals 36, 36 have the tip seat 32.
And become the same. At this time, the upper ends of the external terminals 36, 36 are in electrical contact with the pair of connection terminals 20, 20 provided on the seating surface 6 of the throw-away tip 1, respectively.

Further, according to FIG. 3, the external terminals 36, 36
As shown by the alternate long and short dash line, a lead wire 38 arranged in the chip holder 30 is connected, and the lead wire 38 is connected to a resistance value detection circuit 39 such as an ohmmeter. Cutting edge 9 of the throw-away tip 1 mounted in the pocket 31 (corner portion 8 used for cutting)
It is possible to measure the resistance value of the sensor line 15 provided in the.

In the mounted state of FIG. 3, for example, the cutting edge 9 of the corner portion 8A of the throw-away tip 1 is used for cutting. Then, when the cutting edge 9 of the corner portion 8A is worn, the clamp screw 34 and the pressing metal fitting are loosened, and the throw-away tip 1 is rotated by 90 ° around the center of the rake face 5, so that the corner portion 8A Another adjacent corner portion 8 can be used as a cutting edge 9 for cutting. In this way, the throw-away tip 1 can be rotated by 90 °, and the four corner portions on the one main surface side of the tip 1 can be sequentially used for cutting. In addition, throw away tip 1
By reversing the top and bottom and mounting it on a holder etc., the four corners of the other main surface can be used in order for cutting.
A total of eight corners 8 can be used. Note that when the corner portion of the other main surface is used, the rake surface and the seating surface reversely function.

On the other hand, the base material of the throw-away tip 1 is an alumina sintered body, a silicon nitride sintered body, a cermet, a cemented carbide, a cubic boron nitride sintered body (CBN / Cu).
bicBoron Nitride), diamond sintered body (PCD / Po
Although lycrystalline diamond) and the like can be preferably used, it is desirable to interpose an insulating layer between the base material and the sensor circuit (conductor) particularly when the material is conductive, such as cermet or cemented carbide. .

On the other hand, the conductive band forming the sensor circuit 13, such as the sensor line 15 and the connection line (a pair of connection terminals 20 and 20, the first and second connection lines 15 and 18, the folding line 26, and the connection portion 27). Indicates that the throw-away tip 1 has a strong bonding force to the base material 2, does not react with the work material, and the electric resistance value of the sensor line 15 always shows a predetermined value. Presence or absence can be accurately detected, reaction products are less likely to be generated on the machined surface of the work material, excellent oxidation resistance, and there is no change in the electrical resistance value of the sensor line 15 due to oxide formation Because of the fact that the wear degree of the away tip 1 and the presence or absence of a defect can be accurately detected, Ti, Zr, V, Nb, Ta, Cr, Mo,
4a, 5a, 6a group metals such as W, iron group metals such as Co, Ni, Fe, or metal materials such as Al, TiC, V
C, NbC, TaC, Cr ₃ C ₂ , Mo ₂ C, WC, W
₂ C, TiN, VN, NbN, TaN, CrN, TiC
4a such as N, VCN, NbCN, TaCN, CrCN,
Carbides, nitrides, carbonitrides of group 5a and 6a metals (T
i, Al) N, at least one selected from the group, especially T
At least one selected from the group consisting of iN, (Ti, Al) N, and (Ti, Al) CN, and more preferably TiN.

In order to form the sensor circuit 13 in the present invention, the surface of the base material 2 produced by, for example, molding and firing a predetermined ceramic powder is formed into a predetermined size by laser processing or grinding processing. A recess is formed in the sensor circuit pattern. Then, if desired, C
After forming an insulating layer by any method such as VD method, PVD method such as ion plating, sputtering, vapor deposition, known thin film forming method such as plating method, or heat treatment after dipping or printing treatment, any of the above With this method, the sensor circuit can be formed by filling the conductor with a predetermined thickness thicker than the thickness of the recess. The conductor attached to the portion other than the recess can be easily removed later by blasting or the like. It is also possible to perform this removing step also as a honing processing step.

After that, if desired, a hard coating layer may be formed on the surface of the base material on which the sensor circuit is formed by the above-mentioned thin film forming method or the like.

[0039]

As described above in detail, according to the cutting tool of the present invention, the sensor circuit is formed with the concave portion on the surface of the base material, and the conductor is embedded in the concave portion, so that the impact or the repetition can be prevented. With a stable sensor circuit that does not cause peeling or disconnection of the sensor circuit even with thermal cycles and chips, it suppresses chattering and allows the operator to visually check the sensor circuit pattern to prevent work mistakes. A cutting tool that can be used can be manufactured.

[Brief description of drawings]

1A is a perspective view of an example of a throw-away tip that is a preferred example of a cutting tool of the present invention as seen from the front upper side, and FIG. 1B is a perspective view seen from the front lower side.

FIG. 2 is an enlarged view of a main part of the throw-away tip shown in FIG.

FIG. 3 is an exploded perspective view for explaining an example of mounting the throw-away tip of FIG. 1 on a tip holder.

FIG. 4 is a schematic perspective view for explaining a conventional throw-away tip.

[Explanation of symbols]

1 Throw-away tip 2 base material 5 rake face 6 Seating surface 7 flank 8 corners 9 cutting edges 10 recess w width t thickness A corner 12 conductors 13 Sensor circuit 14 Insulation layer 15 sensor lines 17 reading line 14 connection terminals 24 First side line 26 Folding line 27 Connection 28 Second side line 29 Clamp hole 30 chip holder 31 pockets 32 chip seat 33 Restraint surface 34 Clamp screw 35 screw holes 36 External circuit 38 Lead wire 39 Detection circuit

Claims (4)

[Claims] 1. A recess is formed on the surface of a base material, and a sensor circuit having a conductor embedded in the recess is provided, and a conductive state of the sensor circuit is monitored to detect a wear state of a cutting edge. Cutting tool with wear sensor circuit characterized by. 2. The group of at least one carbide, nitride, carbonitride, Al ₂ O ₃ , diamond and DLC of a metal of Groups 4a, 5a and 6a of the Periodic Table on the surface of the base material and the sensor circuit. The cutting tool with a wear sensor circuit according to claim 1, wherein at least one selected coating layer is formed with a thickness of 50 μm or less, and the unevenness of the surface of the cutting tool is 100 μm or less. 3. The cutting with wear sensor circuit according to claim 1, wherein the base material is made of a conductive material, and an insulating film is interposed between the base material and the conductor. tool. 4. The cutting tool with a wear sensor circuit according to claim 1, wherein a corner portion of the recess has an R shape.