JP3453537B2 - Indexable insert with wear sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a throw-away tip used for cutting.

[0002]

2. Description of the Related Art A throw-away tip mounted on a holder or the like and functioning as a cutting blade is known. The throw-away tip is a disposable tip that is replaced without regrinding when the cutting edge becomes worn. In the throw-away tip, a cutting edge is usually formed at each corner portion of a substantially flat plate-shaped base material which is basically a square or a triangle. When the cutting edge of any corner portion is worn, the cutting edge of another corner portion is used. Then, when the cutting edges of all corners are worn, they are replaced.

By the way, it is not easy to check how much the cutting edge of the throw-away tip has worn. In particular, it is very difficult in working environment to detect the wear amount of the cutting edge during cutting, without interrupting the cutting. The conventional methods for detecting the amount of wear of the cutting edge are (1)
A method of interrupting the cutting process, removing the throw-away tip from the holder, etc., and observing the cutting edge with a tool microscope, etc. (2) Phenomena that accompany wear of the cutting edge, such as a reduction in cutting force or vibration There is a method in which a sensor installed in the vicinity of the processing portion on the machine tool detects the increase of the noise, the generation of abnormal noise, and the like, and estimates the wear amount of the cutting edge based on the detection signal.

However, the method (1) has a problem that the cutting process must be interrupted and the wear amount of the cutting edge cannot be quantitatively detected, resulting in poor accuracy. Further, the method (2) requires a complicated detection device, and has a problem that the detection sensitivity of the wear amount is poor and the reliability is poor. A proposal for solving these problems is described in Japanese Utility Model Publication No. 3-120323. This publication discloses that a sensor line is provided on the flank of the throw-away tip with a conductive film along the cutting edge. It is also disclosed that the width of the sensor line corresponds to the allowable wear width. Therefore, according to the throw-away tip disclosed in this publication, the sensor line is worn along with the wear of the cutting edge, and when the sensor line is interrupted, it can be determined that the cutting edge has reached the end of its life.

Further, Japanese Patent Laid-Open No. 9-38846 discloses that
In a normal cutting tool that is not a throw-away tip, a thin-film circuit is provided on the flank surface, and it is detected that the electrical resistance changes as the thin-film circuit wears as the flank surface wears, and the life of the cutting tool A method for automatically determining is proposed.

[0006]

The method of forming the sensor line of the conductive film along the cutting edge on the flank and detecting the change in the resistance value of the line detects the wear of the cutting edge. It is preferable as a method. However, when trying to adopt this method for the throw-away tip, even if the sensor line is provided along the cutting edge, it is actually difficult to connect the sensor line to an external detection circuit or the like. Encounter.

More specifically, the throw-away tip is a disposable tip as described above, and its size is smaller than 1 cm ³ . The chip is subjected to cutting while being exposed to cutting fluid (water or oil) and chips. Under such an environment, a technique of connecting a sensor line formed on a small throw-away chip to an external detection circuit without trouble has not been realized. The present application provides a throw-away chip with a wear sensor that can solve such problems and can be mounted practically.

The main object of the present invention is that when mounted on a holder or the like, the sensor line formed on the throw-away tip and the external circuit can be reliably electrically connected, and the connection can be achieved without any hindrance to the cutting process. It is an object of the present invention to provide a throw-away tip with a wear sensor that can be used.
Another object of this application is to provide a throw-away chip capable of protecting a connection portion between a sensor line provided in the throw-away chip and an external circuit.

[0009]

According to a first aspect of the present invention, there is provided a base material having a substantially flat plate shape, and one surface of the base material is a rake surface, and the other surface of the rake surface and the back surface is a seating surface. , And flanks are formed on a plurality of side surfaces that intersect the rake face and the seating face, respectively, and a cutting edge is formed by the crossing ridge between the rake face and each flank, and the rake face and two adjacent flank faces are formed. In the throw-away insert where the corner that can be used for cutting is formed by the intersection,
The number of the corner portions is N (N is a natural number of 2 or more), and each of the N corner portions has a sensor line of a conductive film extending along the cutting edge so as to surround the corner portion. The seating surface is provided with two contact regions that are electrically insulated from the base material and that form a pair that can be electrically connected to a predetermined circuit. N
Paired , the throw-away tip is
When the surface functions as a rake surface, the other surface is the seating surface
And when the surface functions as a rake surface,
It is a chip that can be used on both sides and has a seating surface.
The corners are on the one surface side and the other surface side, respectively.
N contact holes are formed on the one surface.
And N pairs are provided on the other surface, and N pairs of connection lines for connecting the N pairs of contact areas and both ends of the sensor lines of the N corners are formed on the surface of the base material. , Which is provided in an electrically insulated state with respect to the base material and has one of the two connecting lines forming a pair,
Extends parallel to the sensor line with a predetermined distance from the saline
Characterized that you have include folding line that is a throw-away tipped wear sensor.

[0010]

According to a second aspect of the present invention, each one of the N pairs of contact regions is provided independently electrically, and N of each of the N pairs of contact regions are electrically connected. The throw-away tip with a wear sensor according to claim 1, wherein the throw-away tip is provided in a state where it is provided. According to a third aspect of the present invention, the N pairs of contact areas provided on one surface of the throw-away tip and the N pairs of contact areas provided on the other surface have exactly the same arrangement shape. The throw-away tip with wear sensor according to claim 1 or 2 , characterized in that.

According to a fourth aspect of the present invention, the connecting line extends to the flank and the seating surface, and the connecting line of the flank is connected to the sensor line at a predetermined inclination angle. The throw-away tip with wear sensor according to any one of claims 1 to 3 . The invention according to claim 5 is the throw-away tip with wear sensor according to claim 4 , characterized in that the connection line is formed in a rotationally symmetrical positional relationship with respect to the center of the flank.

The throw-away tip according to claim 1 is
There are N corners that can be used for cutting on at least one side. Each of the N corner portions is provided with a sensor line for detecting wear of the cutting edge. Further, N pairs of contact areas are provided on the seating surface corresponding to the sensor lines. Thus, when any of the corners is used for cutting, the pair of contact regions corresponding to the sensor lines of the corners can be electrically connected to the probe or the like provided in the holder or the like.

Therefore, no matter which corner portion is used, it is possible to accurately detect the wear of the cutting edge of the corner portion. In addition , the throw-away tip is a tip that can be used on both sides, increasing the number of corners that can be used for cutting, and when using either corner ,
The wear of the cutting edge ridge can be satisfactorily detected.

According to a second aspect of the present invention, each one of the N pairs of contact regions is electrically connected in common. One of the two contact regions forming a pair is a region to which a predetermined voltage is applied from a detection circuit or the like, while the other is a region connected to the ground potential. Therefore, one contact area of the pair of contact areas can be a common ground area that is electrically connected. The formation of such a contact area leads to simplification of the arrangement pattern of the contact area and has an advantage that the processing is easy.

As described in claim 3 , since the N pairs of contact areas on one surface and the N pairs of contact areas on the other surface have exactly the same arrangement shape, either surface is used as a rake face. Even in such a case, the contact area of the surface functioning as the seating surface can satisfactorily contact the probe such as the detection circuit. When the throw-away tip is a tip that can be used on both sides, N pairs of contact areas are provided on both sides. A connection line connecting the sensor line and the contact area must be provided on the flank. Since the area of the flank is limited, if you try to arrange a connection line connected to the contact area on the one surface side and a connection line connected to the contact area on the other surface side on the flank, the connection line Is preferably provided in the direction of inclination with respect to the sensor line in view of the arrangement configuration of the connection line. Therefore, according to the structure of claim 4 , the sensor line and the connection line can be compactly arranged on the flank.

According to the fifth aspect of the invention, since the connection line has a rotationally symmetric positional relationship with respect to the center of the flank, a more compact line arrangement can be achieved. According to the present invention, in the throw-away tip having a plurality of corner portions that can be used for cutting, even when any of the corner portions is used for cutting, wear of the cutting edge of the corner portion can be favorably detected. It can be a throw-away tip.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. Figure 1A
[Fig. 1] is a perspective view of a throw-away tip 1 according to an embodiment of the present invention seen from the front upper side, and Fig. 1B is a perspective view of the throw-away tip 1 seen from the front lower side. The throw-away tip 1 has a base material 2 having a substantially flat plate shape (a substantially rectangular parallelepiped shape). Although the upper and lower sides of the base material 2 are originally not distinguished from each other, for convenience of explanation, one side is described as an upper surface and the other side is described as a lower surface.

A rake face 5 is formed on the upper surface of the base material 2,
The lower surface of the base material 2 is a seating surface 6. A flank 8 is formed on each of the four side surfaces of the base material 2.
A cutting edge 9 is formed by a ridge intersecting the rake face 5 and each flank 8. Furthermore, the intersection of the rake face 5 and the two adjacent flank faces 8 forms a corner 10 which can be used for cutting. A clamp hole 11 is formed at the center of the base material 2 so as to penetrate from the upper surface to the lower surface. The throw-away tip 1 is positioned in a tip pocket of a predetermined holder or the like, and a clamp screw is screwed into the clamp hole 11 to be attached to the holder or the like. In the mounted state, for example, the front upper corner portion 10 of FIG. 1A is used for cutting. Further, by loosening the clamp screw and rotating the throw-away tip 1 by 90 ° around the clamp hole 11, another corner portion 10 can be used for cutting. In this way, by rotating the throw-away tip 1 by 90 °, the four corner portions 10 on the upper surface side can be sequentially used for cutting.

Further, by flipping the throw-away tip 1 upside down and mounting it on a holder or the like, as shown in FIG.
In B, the four corner portions on the lower surface side can be sequentially used for cutting. If the lower corner is used,
The upper surface serves as a seating surface and the lower surface functions as a rake surface.
As described above, in the throw-away tip 1, each of the eight corner portions 10 of the rectangular parallelepiped base material 2 can be used for cutting. Therefore, each of the eight corners 10 has
A sensor line 12 of a conductive film extending along the cutting edge 9 is provided.

The sensor line 12 is provided on the flank 8. Specifically, it extends along the cutting edge 9 so as to surround the corner portion 10 on two adjacent flanks 8 forming the corner portion 10. The sensor line 12 is a line of a conductive film having an upper side in contact with the cutting edge 9 and extending along the cutting edge 9 and having a width W. The sensor line 12 is
It is provided in an electrically insulated state with respect to the base material 2. The width W of the sensor line 12 matches the life reference amount of the corner portion 10 (wear limit of the flank 8). Normally, the life reference amount of the corner portion 10 of the throw-away tip 1 of this type is in the range of 0.05 to 0.7 mm, so the width W of the sensor line 12 is also set to a value equal to the life reference amount. ing.

For example, when the wear of the flank 8 of the throw-away tip 1 is 0.2 mm and the life is reached, the width W of the sensor line 12 is also set to 0.2 mm. When cutting is performed by the corner portion 10, the wear of the cutting edge 9 and the flank 8 progresses as the working time increases.
As the wear of the flank 8 progresses, the sensor line 12 also wears accordingly. When the wear width of the flank 8 reaches the life reference amount or more, the sensor line 12 having the width W matched with the life reference amount is broken due to wear. Since the resistance values at both ends of the sensor line 12 are measured by an external circuit as described later, when the resistance value of the sensor line 12 becomes infinite, the cutting edge ridge 9 of the corner portion 10 reaches the end of its life. It can be determined that it did.

As shown in FIG. 1B, the seating surface 6 is provided with two paired contact areas 13 and 14. The two contact regions 13 and 14 are formed of a conductive film and are provided in an insulating state with respect to the base material 2. The contact regions 13 and 14 are regions that can be electrically connected to, for example, a resistance value detection circuit provided outside the holder. As will be described later, when the throw-away tip 1 is attached to the holder, the probe of the detection circuit provided on the tip seat of the holder is electrically connected to the contact areas 13 and 14. The contact areas 13 and 14 are preferably as large as possible so that the probe of the detection circuit or the like can easily contact.

Connection lines 15 and 16 are provided from the flank surface 8 to the seating surface 6 of the base material 2 in an insulated state from the base material 2 by a conductive film. The connection line 15 electrically connects one end 121 of the sensor line 12 and one contact region 13, and the connection line 16 electrically connects the other end 122 of the sensor line 12 and the other contact region 14. To connect to. The connection lines 15 and 16 are made thicker than the width W of the sensor line 12, and the electric resistance value of the connection lines 15 and 16 is made sufficiently larger than the electric resistance value of the sensor line 12. Therefore, the connection lines 15 and 16 do not affect the detection of the change in the electric resistance value of the sensor line.

The connection line 16 connected to the other end 122 of the sensor line 12 has a folded line 17 in a part thereof. The folding line 17 is connected to the other end 122 of the sensor line 12 at the folding portion 18. The folding line 17 extends in parallel with the sensor line 12 at a predetermined distance D from the sensor line 12. By forming a part of the connection line 16 into the folded line 17, the connection line 15 and the connection line 16 can be provided on the flank 8 in parallel at a predetermined interval.
There is an advantage that 6 can be arranged in area efficiency.

The distance D between the sensor line 12 and the folding line 17 is set to a width of 0.05 mm or more. Preferably, the width D should be as wide as possible. The reason is that, when cutting is performed at the corner portion 10, the work piece is cut by the cutting edge 9 included therein. The shavings are generated from the rake face 5 toward the flank face 8 while curling, for example. The generated chips may adhere between the sensor line 12 and the folding line 17 and may electrically short the both lines.

Therefore, by widening the distance D between the sensor line 12 and the turn-back line 17, it is possible to prevent an electrical short circuit between the lines 15 and 16 due to adhesion of chips or the like. The two connection lines 15 and 16 formed on the flank 8 are not orthogonal to the sensor line 12 (in other words, to the cutting edge 9) but in a direction intersecting at a predetermined inclination angle. It is an inclined line that extends. The reason for this is that the arrangement positions of the contact regions 13 and 14 provided on the seating surface 6, which is the lower surface, and the arrangement positions of the contact regions 13 and 14 provided on the upper surface are exactly the same.

More specifically, the four corner portions 10 located on the upper surface side of FIG. 1A can be sequentially used for cutting by rotating the throw-away tip 1 by 90 °. Throw-away tip 1 90 °
Each of which rotates four pairs of contact areas 13 shown in FIG. 1B.
14 also rotates 90 ° in sequence. The contact regions 13 and 14 connected to the sensor line 12 of the corner portion 10 used for cutting are connected to the probe of the external circuit.
Therefore, the four pairs of contact areas 13 provided on the seating surface 6,
14 is in a positional relationship of being rotated by 90 ° with respect to the center of the seating surface 6.

Further, since the throw-away tip 1 can be used upside down, the four pairs of contact regions 13 and 14 provided on the upper surface shown in FIG. 1A also rotate 90 ° with respect to the center of the upper surface. It is in the target positional relationship. Thus, in order to make the contact areas 13 and 14 provided on the upper surface and the contact areas 13 and 14 provided on the lower surface exactly the same, it is necessary to obliquely provide the connection lines 15 and 16 on the flank 8. is there. Incidentally, in the case of a throw-away tip in which only one side (for example, an upper surface) corner portion called a so-called positive type is used for cutting, the connecting lines 15 and 16 may not be provided obliquely on the flank 8.

FIG. 2 is a plan view showing a modified example of the four pairs of contact regions 13 and 14 provided on the seating surface 6 of the throw-away tip 1. The seating surface 6 has four pairs of contact areas 13, 1
4 are provided, each of which contacts a probe of an external circuit when the corresponding corner portion is used for cutting.
By the way, when the contact regions 13 and 14 are connected to an external circuit and the electric resistance value of the sensor line 12 is measured, a predetermined voltage is applied to the one contact region 13 from the external circuit and the other contact region 13 is applied. 14 is connected to the ground potential of an external circuit. In other words, whichever contact area 13, 14 is used, one contact area is connected to ground potential. Thus, for example, contact area 1
4 may be used as the ground potential, and one contact area 14 of each of the four pairs of contact areas may be electrically connected in common. An example of such a configuration is shown in FIG.

Such a shape of the connecting region is such that a conductive film is formed on the entire seating surface 6 and the film is processed by laser to form the contact regions 13 and 14 and the connecting lines 15 and 16. Moreover, there is an advantage that the laser processing time can be shortened. This is because the area of the conductive film to be removed by laser processing can be small. FIG. 3 is a perspective view showing another embodiment of the sensor line. The sensor line 12 described in FIG. 1 had its upper side in contact with the cutting edge 9 and extended in parallel with the cutting edge 9 with a width W so as to surround the corner 10. On the other hand, the sensor line 123 in FIG. 3 has a width of X (W> X) and is a line narrower than the sensor line 12. Like the sensor line 12, the sensor line 123 is also a conductive film and is formed in the base material 2 in an insulated state. The sensor line 123 extends parallel to the cutting edge 9 such that the lower side thereof, that is, the side 124 on the side farther from the cutting edge 9, has a distance W from the cutting edge 9.

This distance W, like the width W of the sensor line 12 described in FIG. 1, is matched with the life reference amount of the flank 8. Therefore, as the use time of the cutting edge 9 increases, the wear of the flank 8 progresses from the cutting edge 9 side, and eventually the wear reaches the sensor line 123 and its lower side 124.
Then, the sensor line 123 is disconnected. As described above, the sensor line 123 may have a configuration in which the side (lower side) 124 on the side far from the cutting edge 9 is separated from the cutting edge 9 by a predetermined distance W.

FIG. 4 is a perspective view showing still another embodiment of the sensor line. The sensor line 125 shown in FIG.
Is a plurality of, for example, three lines 12 extending in parallel.
6, 127, 128. The distance from the cutting edge 9 to the lower side of the line 128 that is farthest away is W. This W is a value equal to the width W of the sensor line 12 described in FIG. In this way, the plurality of lines 126, 12 extending in parallel with the sensor line 125
With the configuration of 7, 128, disconnection due to wear occurs sequentially from the sensor line near the cutting edge 9 depending on the progress of wear of the flank 8. Therefore, it is possible to detect stepwise how much the cutting edge 9 of the corner portion 10 used for cutting is worn.

In FIGS. 1, 3 and 4, the distance W from the cutting edge 9 to the lower side of the sensor line is matched with the life reference amount of the corner 10 (wear limit of the flank 8). I explained the case. However, this dimension W may be a dimension related to the wear of the flank 8 instead of the wear limit of the flank 8. For example, in the case of preliminary cutting (rough cutting) or standard cutting, the wear limit of the flank 8 is relatively large,
In finish cutting, when the flank 8 is worn to some extent,
The throw-away tip needs to be replaced. In accordance with such a situation, the above dimension W may be a dimension that can be used as a throw-away tip but that can detect wear that cannot be used for finish cutting.

FIG. 5 is a schematic perspective view showing how the throw-away tip 1 shown in FIGS. 1A and 1B is attached to a holder. A pocket 21 for mounting a chip is formed at the tip of the holder 20. The bottom surface of the pocket 21 is a chip seat 22. The side surface of the pocket 21 abuts the side surface of the chip, and the constraining surface 23 for constraining the chip.
Has become. The throw-away tip 1 is stored in this pocket 21, and the seating surface 6 is brought into contact with the tip seat 22. Further, the side surface thereof is brought into contact with the restraining surface 23. Then, the clamp screw 24 is inserted into the clamp hole 11 of the throw-away tip 1 from above, and the tip of the clamp screw 24 is inserted into the tip seat 22.
Is screwed into a screw hole 25 formed in the center of the. As a result, the throw-away tip 1 is attached to the holder 20.

In the tip seat 22, a pair of probes 26 are provided at positions facing the contact areas 13 and 14 connected to the sensor line 12 provided in the corner portion 10 used for cutting the attached throw-away tip 1. , 27 are projected. The probes 26 and 27 are elastically biased upward and protrude from the tip seat 22 by, for example, several mm. When the throw-away tip 1 is mounted in the pocket 21,
The probe 2 is attached by the seating surface 6 of the throw-away tip 1.
6, 27 are pushed down, and their upper ends are flush with the tip seat 22. At this time, the upper ends of the probes 26 and 27 are contact areas 1 provided on the seating surface 6 of the throw-away tip 1.
3 and 14 are in electrical contact with each other.

As shown by the alternate long and short dash line, the probes 26 and 27 are connected with a lead wire 28 laid inside the holder 20, and the lead wire 28 is connected to a resistance value detecting circuit 29 such as an ohmmeter. ing. Therefore, the detection circuit 29
Thereby, the resistance value of the sensor line 12 provided in the corner portion 10 used for cutting the throw-away tip 1 mounted in the pocket 21 can be measured.

When the throw-away tip 1 is mounted in the pocket 21, almost the entire seating surface 6 of the throw-away tip 1 is in close contact with the tip seat 22. Therefore, even if cutting fluid (water or oil) is applied to the tip of the holder 20 during cutting, or chips scraped by the throw-away tip 1 scatter around the throw-away tip 1, Chip seat 22 where cutting fluid and chips are in close contact
And the seating surface 6 do not enter. That is, the seating surface 6 and the tip seat 22 of the throw-away tip 1 are protected from cutting fluid and chips. Therefore, the probes 26 and 27 provided on the tip seat 22 and the contact regions 13 and 14 provided on the seating surface 6 are in a state where good electrical connection is maintained during cutting.

Furthermore, the probes 26, 26 and the lead wires 28 connected to them can be provided in the holder 20. The holder 20 shown in FIG. 5 is only an example, and as a holder to which the throw-away tip 1 according to this embodiment can be attached, for example, the prior application of the applicant of the present application (Japanese Patent Application No. 11-277548) is used. You may use. Figure 6
Examples of various shapes of the throw-away tip to which the present invention can be applied are shown in A, B, C, D, and E by a plan view and a front view (side view on the front side), respectively.

FIG. 6A shows a throw-away tip having the shape described in FIG. 1 in which the base material has a substantially square planar shape. FIG. 6B is a throw-away tip in which the base material has an equilateral triangular planar shape, and the tip has three upper and lower surfaces.
Two corners can be used for cutting. In other words, there are a total of 6 corners, each with a sensor line,
A contact area corresponding to each sensor line is provided on the seating surface.

FIG. 6C shows a chip in which the planar shape of the base material is a rhombus. In the throw-away tip shown in FIG. 6C, four corner portions having diagonal corners and having acute angles are used for cutting.
Similar to FIG. 6B, FIG. 6D is a throw-away tip formed of a base material having an equilateral triangle in plan view. In the throw-away tip of FIG. 6D, the sensor line has a plurality of sensor lines, as described in FIG. Figure 6
Unlike FIG. 6A to FIG. 6E, E is a throw-away tip, which is so-called positive type and whose one side is used for cutting. This chip has a rake surface on the top and a seating surface on the bottom, and it cannot be used upside down. Three corners on the top surface are used for cutting. Therefore, sensor lines are provided in the three corners, respectively. In addition, a contact area is provided on the lower seating surface,
A connection line is provided on the flank of the side surface.

In addition to the shapes described above, the present invention can be applied to, for example, a throw-away tip having a round or elliptical planar shape. Next, the base material of the throw-away tip according to the present invention, the material of the sensor line, the contact region, the connection line, and the like, and the manufacturing method will be described. (1) Type of base material As the material of the throw away tip base material, alumina sintered body, silicon nitride sintered body, cermet, cemented carbide, cubic boron nitride sintered body (cBN / cubic Boron Nitride) ),
A diamond sintered body (PCD / Polycrystalline Diamond) or the like can be used.

(2) Base Material Composition and Manufacturing Method The base material composition that can be preferably used in the present invention and the manufacturing method thereof will be described below. Alumina Sintered Body As the alumina sintered body, 2 to 30% by weight of ZrO ₂ , 0.01 to 5% by weight of at least one of Fe, Ni and Co oxides, and the balance of Al ₂ O ₃ Also, an alumina-based sintered body composed of unavoidable impurities can be used. A
Fe, Ni, C as the third component in the l ₂ O ₃ -ZrO ₂ system.
The fracture toughness can be remarkably improved by containing at least one kind of the oxide of o in a specific range and densifying it by hot isostatic firing.

The method for producing this alumina-based sintered body is based on Zr.
After forming a mixed powder containing 10 to 20% by weight of O ₂ , 0.2 to 2% by weight of at least one of Fe, Ni and Co oxides, and the balance of Al ₂ O ₃ and unavoidable impurities, The molded body is fired at 1400 to 1500 ° C. and further hot isostatically fired at a temperature of 1300 to 1500 ° C. to obtain a sintered body having a strength of 110 kg / mm ² or more. At least one oxide of Co, Ni, Fe as a third component is contained in a proportion of 0.2 to 2% by weight. If the content is less than 0.2% by weight, the fracture toughness cannot be improved and 2
If it exceeds 5% by weight, the flexural strength decreases.

The amount of ZrO _{2 in} the sintered body is preferably 10 to 20% by weight, more preferably 15 to 20% by weight. If the amount of ZrO ₂ is below 10 wt% ZrO ₂ less energy absorption of the crack tip by the addition, little improvement in toughness. On the other hand, if it exceeds 20% by weight, monoclinic Zr in the ZrO ₂ crystal phase in the sintered body is used.
The amount of O ₂ (m-ZrO ₂ ) increases, and the amount of ZrO ₂ involved in energy absorption at the crack tip is substantially reduced,
Fracture toughness decreases.

Furthermore, the ZrO ₂ crystal phase in the sintered body is a monoclinic ZrO ₂ (m-ZrO _{2) based on the} total amount of ZrO _2.
2 ) is preferably 50% or less, particularly preferably 30% or less. If it exceeds 50%, the fracture toughness is significantly reduced. The other crystal phase is tetragonal ZrO ₂ (t-ZrO ₂ ) or cubic ZrO ₂ (c-ZrO ₂ ), and by containing 50% or more of these, t-ZrO ₂ → m-
ZrO ₂ or c-ZrO ₂ → t-ZrO ₂ → m-Z
The phase transition of rO ₂ effectively absorbs the energy at the crack tip.

Particle size of each crystal in the alumina sintered body
Is Al₂O₃Crystals less than 1 μm, ZrO₂1 μm crystal
Below, especially 0.5 μm or less is good and larger than these values
In all cases, the bending strength decreases. This alumina
As a method for producing a sintered body, A having an average particle size of 1 μm or less is used.
l₂O ₃Against ZrO₂10 to 20% by weight,
Oxide of Co, Ni, Fe or oxide by firing
0.2 to 2% by weight in terms of oxides of variable compounds
Weigh and mix them in proportions, and add these to a medium such as a dispersant and distilled water.
Mix and grind with quality. After crushing, use known molding means
After shaping, bake.

As a firing method, first, atmospheric pressure firing is performed in the atmosphere, hot firing is performed at 1400 to 1500 ° C., and further hot isostatic firing is performed at 1300 to 1500 ° C. Silicon Nitride Sintered Body As the silicon nitride based sintered body, 85 to 96 mol% of silicon nitride, 1 to 5 mol% of Group 3a element of the periodic table in terms of oxide, and impurity oxygen in terms of SiO _{2 are} calculated. The content of the aluminum compound is 3 to 10 mol%, and the content of the aluminum compound is an oxide (A
1% by weight or less in terms of (l ₂ O ₃ ). here,
Impurity oxygen is residual oxygen obtained by subtracting oxygen mixed as an oxide of a Group 3a element of the periodic table from the total amount of oxygen in the sintered body, most of which is impurity oxygen in the silicon nitride raw material powder or added oxygen. It is oxygen in the formed silicon oxide.

If the content of silicon nitride is less than 85 mol% or the amount of oxide of the Group 3a element of the periodic table is more than 5 mol%, the hardness of the sintered body is lowered. 96 mol% silicon nitride
More and the oxide equivalent of Group 3a element of the periodic table is 1
If it is less than mol%, a dense body cannot be obtained and the strength of the sintered body is lowered. On the other hand, silicon oxide (SiO ₂ ) of impurity oxygen
If the converted amount is more than 10 mol%, the toughness is lowered and the fracture resistance is lowered. Further, if the amount of impurity oxygen is less than 3 mol%, a dense body cannot be obtained and the strength of the sintered body decreases. And when the amount of the aluminum compound is more than 1% by weight,
The resistance to cast iron deteriorates and the wear resistance during high-speed and immediate cutting deteriorates.

The desirable composition of the sintered body is 88 to 95 mol% of silicon nitride, 2 to 5 mol% of an element of Group 3a of the periodic table in terms of oxide, and 2% of impurity oxygen in terms of silicon oxide.
It is preferable that the content is ˜8 mol%. Further, it is desirable that the amount of the aluminum compound is 0.5% by weight or less, particularly 0.3% by weight or less in terms of oxide. The elements of Group 3a of the periodic table are Y, Sc, Yb, Er, D.
y, Ho, Lu and the like, and among these, Er, Y
b and Lu are good.

The silicon nitride sintered body is composed of a silicon nitride crystal phase and a grain boundary phase containing a Group 3a element of the periodic table, silicon, nitrogen and oxygen in terms of structure. At this time, it is important that the lattice constant of the silicon nitride crystal phase is 7.606 angstroms or less on the a-axis, particularly 7.602 angstroms or less, and 2.910 angstroms or less on the c-axis, and particularly 2.908 angstroms or less. this is,
7.606 angstrom on a-axis and 2.910 on c-axis
If it is larger than angstrom, the ionic bondability of silicon nitride increases and the bonding force of silicon nitride decreases, and it easily reacts with the work material during cutting, so-called diffusion wear increases and wear resistance deteriorates. Is. The silicon nitride crystal phase exists as a β-type needle crystal and has a minor axis of 0.
1 to 3 μm, average aspect ratio (major axis / minor axis) is 2 to
10 particles.

Although the grain boundary phase may be amorphous in some cases, it is preferably crystallized. The crystal phase is preferably apatite, YAM, wollastonite, disilicate or monosilicate. Further, to the silicon nitride sintered body, an appropriate amount of metal elements such as W, Mo, Ti, Ta, Nb, and V of the periodic table group 4a, 5a, and 6a and their carbides, nitrides, and silicides are added. Or, or SiC,
It is also possible to improve the characteristics as a composite material by adding an appropriate amount as dispersed particles or whiskers to the sintered body.

In the method of manufacturing the silicon nitride sintered material, first, silicon nitride powder is used as a main component as a raw material powder. The silicon nitride powder itself is α-Si ₃ N ₄ , β-Si.
Any of ₃ N ₄ can be used. The particle size thereof is preferably 0.4 to 1.2 μm. Next, as an additive component, an oxide of a group 3a element of the periodic table and a silicon oxide powder are used, and these are weighed in appropriate amounts and mixed and pulverized by a ball mill or the like. These are 1 to 5 mol% of the Group 3a element oxide of the periodic table and 3 to 10 of silicon oxide in the green body before sintering.
The mixture is mixed at a mol% ratio, the aluminum compound is not substantially added, and even if mixed in the molded body as an impurity, the amount is controlled to be 1% by weight or less in terms of oxide.
The silicon oxide includes the amount of impurity oxygen in the silicon nitride powder converted into silicon oxide. Therefore, the starting composition is determined in consideration of the mixing of the aluminum component from the ball mill during mixing and pulverization and the oxygen content due to oxidation.

The molded body can be obtained by molding the mixed powder into a throw-away chip base material by, for example, press molding, casting molding, extrusion molding, injection molding, cold isostatic molding or the like. The obtained molded body is fired by, for example, a hot pressing method, a normal pressure firing, a nitrogen gas pressure firing method, and further, a hot isostatic firing method (HIP) in which the firing is performed under a high pressure of 2000 atm. ) Is performed, the molded body is immersed in a glass bath, or a glass seal is formed on the surface, and the above HIP treatment is performed to achieve densification. If the firing temperature at this time is too high, solid solution of aluminum in the silicon nitride crystal which is the main phase is promoted, grain growth is caused and the strength is lowered, and the manufacturing apparatus becomes expensive.
Firing is preferably performed in a non-oxidizing atmosphere containing nitrogen gas at 50 to 2000 ° C., particularly 1700 to 1950 ° C.

The cermet cermet contains Ti in an amount of 50 to 80% by weight in terms of carbide, nitride or carbonitride, and an element of Group 6a in the periodic table in an amount of 10 to 40% in terms of carbide (nitrogen). 70% to 90% by weight of a hard phase component having an atomic ratio represented by (/ carbon + nitrogen) in the range of 0.4 to 0.6 and 10% to 30% by weight of a binder phase component made of an iron group metal. After the compact is placed in a vacuum furnace, the temperature is raised to 1 to 30 at a temperature above the liquid phase appearance temperature of the iron group metal.
By introducing nitrogen gas at a pressure of torr and reaching the maximum sintering temperature, the pressure of the nitrogen gas is reduced and firing is performed, whereby the maximum surface roughness of the burnt surface is 3.5 μm or less and the porosity is A-1. It is possible to obtain a TiCN-based cermet in which a modified portion having a toughness and hardness higher than that of the inside is present in the surface layer portion from the surface to 1000 μm.

The TiCN-based cermet has a hard phase component of Ti of 50 in terms of carbide, nitride or carbonitride.
To 80% by weight, especially 55 to 65% by weight, W,
A Group 6a element of the periodic table such as Mo is contained in an amount of 10 to 40% by weight, particularly 15 to 30% by weight in terms of carbide. At this time, in the hard phase component, if the amount of Ti is less than 50% by weight, the wear resistance decreases, and if it exceeds 80% by weight, the sinterability decreases, which is not preferable. Further, the Group 6a element is
Although it has the effect of suppressing grain growth and improving the wettability with the binder phase, if it is less than 10% by weight, the above effect cannot be obtained, the hard phase becomes coarse, and the hardness and strength decrease. Further, if it exceeds 40% by weight, an unhealthy phase such as η phase is generated and sintering becomes difficult.

In addition to the above, Ta and Nb are used as hard phase components for the purpose of improving crater wear resistance, and Zr, V, Hf, etc. are used as nitrides, carbides and carbonitrides for the purpose of improving plastic deformation resistance. It is also possible to include 5 to 40% by weight as a product. However, if it exceeds 40% by weight, deterioration of wear resistance and generation of pores and voids tend to remarkably increase, which is not preferable. On the other hand, the binder phase is Fe, C
Mainly composed of iron group metals such as O and Ni.
A hard phase forming component may also be included. The hard phase component as a whole of the sintered body is 70 to 90% by weight, and the binder phase component is 10 to 30% by weight.

The major feature of the cermet used as the base material of the present invention is that the atomic ratio represented by (nitrogen / carbon + nitrogen) in the hard phase component is 0.4 to 0.6, particularly 0.4 to 0.5. The point is set to the range of. If this atomic ratio is less than 0.4, improvement in toughness and wear resistance cannot be expected. On the other hand, if it exceeds 0.6, pores and voids are generated in the sintered body, and the reliability as the throw-away tip is lowered. In addition, the characteristics of this cermet are that, despite the large amount of nitrogen as described above, there are virtually no pores and voids inside, and the sintered surface of the sintered body is extremely smooth and its maximum Surface roughness is 3.5 μm or less, toughness,
The effect of improving wear resistance and heat resistance can be maintained for a long period of time, and it becomes possible to achieve a long life and high reliability as a throw-away tip. In addition, it becomes possible to commercialize the sintered body after sintering without performing a polishing step or the like.

The TiCN-based cermet is produced by the following composition: Ti of 50 to 80% by weight in terms of carbide, nitride or carbonitride, and 10 to 40% by weight of element of Group 6a of the periodic table in terms of carbide. And a hard phase component having an atomic ratio represented by (nitrogen / carbon + nitrogen) in the range of 0.4 to 0.6 and having a binder phase of 10 to 30% by weight. Create a compact. Specifically, as the raw material powder, Ti
C, TiN, TiCN, etc., and W as a Group 6a system
C, Mo2C, MoC, etc., or a compound carbide or compound carbonitride of these is mixed to have the above composition, and then known molding means such as press molding, extrusion molding, cast molding, injection molding, Mold by cold isostatic pressing or the like.

At this time, as described above, TA, Nb, Z
It is of course possible to use a combination of carbides such as r, V, Hf, nitrides, carbonitrides and the like. Note that if TiC is used as the Ti-based material, the sinterability decreases, and partial grain growth may occur. Therefore, Ti (CN) or Ti (C
A combination of N) and TiN is more preferred. The obtained molded body is set in a vacuum furnace and transferred to firing. In particular,
It is heated in a vacuum furnace at 0.5 Torr or less, and nitrogen gas having a pressure of 1 to 30 Torr is introduced at a predetermined time. By introducing this nitrogen gas, thermal decomposition of nitride such as TiN contained in the molded body is suppressed, and generation of pores and voids due to thermal decomposition is prevented. This timing of introducing nitrogen gas is particularly important in the firing. The reason for this is that densification usually starts near the liquid phase appearance temperature of the iron group metal during the temperature rising process, but the densification is more than this liquid phase appearance temperature, especially 5% or more than the theoretical density ratio to the initial molded body. Introduce in stages. At the stage of densification of 5% or more, a film is formed on the surface of the molded body in the liquid phase. This is to prevent the nitrogen gas from remaining in the voids existing in the molded body by introducing the nitrogen gas after forming the coating film, resulting in the formation of pores and voids.

However, when the nitrogen gas introduction timing exceeds 90% of the theoretical density ratio, the effect of suppressing the decomposition of nitride is not substantially obtained, and the surface of the sintered body tends to be roughened. It is desirable to introduce at a density of less than or equal to%. After the temperature in the furnace reaches the maximum sintering temperature, the nitrogen gas is reduced in pressure to a pressure lower than the pressure set in advance and then returned to vacuum, or is fired while gradually lowering the pressure. This is because if the pressure is further increased after the maximum sintering temperature is reached, a brittle nitride layer that is coarse and contains almost no metal is generated on the surface of the sintered body, causing roughening of the burnt surface and increasing the toughness of the surface. This is because it will significantly decrease.

The nitrogen gas pressure is 1 to 30 Tor.
The reason for limiting to r is that if it is less than 1 Torr, the effect of suppressing decomposition of nitrides is not obtained, and if it exceeds 30 Torr, the sinterability is reduced and free carbon may be precipitated, which reduces the toughness of the sintered body. Is. By such a manufacturing method, it is possible to substantially eliminate pores and voids in the sintered body and to make the surface state smooth. Furthermore, according to this manufacturing method, as described above, it has a peculiar property that a modified portion having high hardness and high toughness is formed in the surface layer of the sintered body.

Further, the throw away tip base material of various shapes can be formed by cermet, but it is desirable to control the shrinkage rate during sintering as the shape becomes complicated. The reason for this is that there is a difference in the shrinkage curves of the compacts, so that as the shape of the compact becomes complicated, fine pores and cracks may occur on the surface of the final sintered body.
In order to prevent such a phenomenon, it is necessary to make the shrinkage rate during sintering slow. Therefore, when introducing the nitrogen gas, by introducing an inert gas such as He or Ar in advance, it is possible to suppress the decomposition of the nitride and smoothly promote the shrinkage without impairing the sinterability. it can. This inert gas is introduced at a temperature about 50 to 200 ° C. lower than the nitrogen gas introduction temperature. That pressure is
It is desirable that the pressure is 1 atm or less.

Cemented Carbide Cemented Carbide is composed of a hard phase and a binding phase. The hard phase is tungsten carbide or 5 to 5 of tungsten carbide.
15% by weight is replaced with carbides, nitrides and carbonitrides of metals of Groups 4a, 5a and 6a of the Periodic Table. When components other than tungsten carbide are mixed, the hard phase is W
It is composed of a C phase and a composite carbide solid solution phase or a composite carbonitride solid solution phase. The binder phase has an iron group metal such as Co as a main component, and Co is contained in a total amount of 5 to 15% by weight.

The cemented carbide preferably used is the above-mentioned hard alloy.
Consists of cobalt tungsten carbide in addition to phase and binder phase
It is good to have a phase. This cobalt tungsten charcoal
As the compound, Co₃W₃C, Co₆W₆C, Co₂W
_FourC, Co₃W₉C_FourThe compound of is known. these
In the X-ray diffraction curve of cobalt tungsten carbide of
The maximum peak is Co₃W₃In C, (333) and (51
1) Synthetic peak, Co ₆W₆In C, (333) and (5
11) synthetic peak, Co₂W_FourIn C, (333)
Synthetic peak of (511), Co₃W₉C_FourThen (30
1) but of these cobalt tungsten carbides
Of the peaks, the highest peak height is I1, carbonization
The maximum peak of tungsten is the (001) peak of WC.
Peak expressed by I1 / I2, where the peak height is I2
The intensity ratio is greater than 0 and 0.15 or less, preferably 0.
It is important that it is 01-0.10. Peak intensity ratio
Was set to the above range because the intensity ratio was 0.
No precipitation of cobalt tungsten carbide in the alloy
This is because the wear resistance of the material decreases and exceeds 0.15
And due to the precipitation of excess cobalt tungsten carbide,
This is because the gold strength is reduced.

It is desirable that the cobalt tungsten carbide phase exists in the alloy as a phase having an average particle size of 5 μm or less, particularly 3 μm or less. This is because when the average particle size exceeds 5 μm, the strength of the entire alloy is reduced because the cobalt tungsten carbide is inherently brittle. Optimally, the average particle size is 2 μm or less. In addition, with the formation of the cobalt tungsten carbide phase, the binder phase C
The lattice constant of Co varies due to the solid solution of W in o. However, the lattice constant of Co of the cemented carbide is preferably in the range of 3.55 to 3.58.

In producing a cemented carbide, one or two selected from WC powder as a raw material powder, carbides, nitrides and carbonitrides of metals of Groups 4a, 5a and 6a of the Periodic Table.
The above-mentioned powders and Co powders are weighed in the amounts described above, mixed and pulverized, molded by a known molding method such as press molding, and then baked. The degree of vacuum is 10 ^-1 to 10 ^-3 T
1 in the temperature range of 1623 to 1773K in a vacuum of orr
Perform from 0 minutes to 2 hours. It should be noted that the precipitation of cobalt tungsten carbide is the total carbon amount in the carbon amount of the primary raw material and the addition amount of the carbon powder, and the carbides of the metals of Groups 4a, 5a, and 6a of the periodic table which partially replace the tungsten carbide. , Nitride,
It can be controlled by the amount of carbonitride added. For example, when the carbon content of the raw material used is lower than the stoichiometric composition, it is likely to precipitate.

By depositing cobalt tungsten carbide as a cemented carbide in a very small amount, excellent cutting performance can be obtained particularly when stainless steel is cut. This is because the cobalt-tungsten carbide itself has high hardness, so that it has excellent wear resistance, and further, the amount of carbon solid-dissolved in the binder phase decreases and the amount of W solid-solution increases and the binder phase increases as the cobalt-tungsten carbide is formed. Is solid solution strengthened.
Further, the thermal expansion coefficient of the cobalt tungsten carbide formed is different from that of the WC phase, which occupies most of the alloy, so that residual compressive stress occurs and the fracture resistance is also improved.

(3) Conductive film of sensor line, etc. The sensor line formed on the flank of the base material of the throw-away chip has a predetermined electric resistance value. By measuring the change in the electric resistance value with an ohmmeter, it is possible to detect the degree of wear of the throw-away tip and the presence or absence of a defect. The sensor lines are Ti, Zr, V,
Nb, Ta, Cr, Mo, W and other 4a, 5a and 6a group metals, Co, Ni, Fe and other iron group metals, Al and other metal materials, TiC, VC, NbC, TaC, Cr ₃ C
₂ , Mo ₂ C, WC, W ₂ C, TiN, VN, NbN,
TaN, CrN, TiCN, VCN, NbCN, TaC
It is formed of a carbide, nitride, carbonitride, (Ti, Al) N, or the like of a 4a, 5a, or 6a group metal such as N or CrCN.

Among these, TiN has a strong bonding force to the base material of the throw-away tip, does not react with the work material, and the electric resistance value of the sensor line always shows a predetermined value, and the wear degree of the throw-away tip, It is possible to accurately detect the presence or absence of defects, effectively prevent the formation of scratches due to reaction products on the machined surface of the work material, have excellent oxidation resistance, and use the sensor line due to oxide formation. It can be suitably used for the reasons that there is no change in the electric resistance value, the degree of wear of the throw-away tip, the presence or absence of a defect can be accurately detected, and the like.

The sensor line is created as follows. First, by adopting a CVD method, a PVD method such as ion plating, sputtering, or vapor deposition, a plating method, or the like, a conductive film is deposited to a predetermined thickness on the flank of the base material of the throw-away chip. After that, the conductive film is processed into a predetermined pattern by laser processing or etching. The specific method of forming the sensor line is as follows. For example, when the sensor line is made of TiN and is formed by adopting a CVD method, the base material of the throw-away chip is heat-resistant with the temperature set to 900 ° C. to 1050 ° C. and the pressure set to 10 to 100 kPa. Place in an alloy reaction vessel. Next, in the reaction vessel, TiCl ₄ is added in an amount of 1 to 5 ml / min, H ₂ is added in an amount of ₂₀ to 301 / min, N 2
₂ at 10 to 201 / min for 20 minutes to flow TiN
A reaction product of HCl with HCl is formed and the TiN is deposited on the surface of the base material of the throw-away tip.

Further, ion plating, which is one of the PVD methods, is used for (Ti, Al) N or (Ti, A).
l) When forming a sensor line made of CN, for example, a base material of a throw-away tip and a Ti—Al alloy as a cathode electrode (evaporation source) are installed in an arc ion plating apparatus. Next, 1 × 10 ^-5
After heating to 500 ° C while maintaining a vacuum of torr,
Ar gas of 1 × 10 ⁻³ torr was introduced into the apparatus.
It becomes an atmosphere. Then, in this state, the base material is -800V.
Is applied to clean the surface of the base material by Ar gas bombarding. And finally, nitrogen gas or nitrogen gas and methane gas are introduced as a reaction gas into the apparatus, and 5 ×
While making the reaction atmosphere 10 ⁻³ torr and lowering the bias voltage applied to the base material to −200 V, arc discharge is generated between the cathode electrode and the anode electrode,
By reacting the Ti-Al alloy discharged from the cathode electrode in a reaction atmosphere, (Ti, Al) N or (Ti, Al)
It is made CN and adhered to the surface of the base material.

The conductive film such as TiN, (Ti, Al) N, (Ti, Al) CN, etc., deposited on the surface of the base material of the throw-away tip, is processed by laser processing, etching, etc. It is processed into a predetermined pattern such as a connection line. For example, in the case of processing into a predetermined pattern by laser processing, a YAG laser having a wavelength of 1.06 μm is used at 35 kHz for TiN or the like deposited on the surface of the base material
Output of 10A, width 50μm, drawing speed 100 ~ 30
By irradiation scanning at 0 mm / s, or CO
_The irradiation is performed by irradiating and scanning _two lasers with an output of 20 W at an irradiation area diameter of 0.3 mm and a drawing speed of 0.3 m / min.

When the thickness of the conductive film is less than 0.05 μm, the bonding to the surface of the base material becomes weak and the electric resistance value of the sensor line becomes high, so that the wear degree and the defect of the throw-away tip can be accurately measured. There is a risk that it will be difficult to detect. Further, if an attempt is made to form a conductive film having a thickness of more than 20 μm, a large stress is internally generated inside the conductive film during formation, and the internal stress weakens the bonding of the conductive film to the surface of the base material. There is a risk. Therefore, the conductive film has a thickness of 0.05 to 2
The range is preferably 0 μm, and optimally 0.1 to
It is preferable to set it in the range of 5 μm.

In the sensor line, etc., the base material of the throw-away tip is an alumina sintered body, a silicon nitride sintered body, cBN.
When it is formed of an insulating material such as, it is directly formed on the surface. When the base material is made of a conductive material such as cemented carbide or cermet, it is formed with an intermediate layer made of an insulating material such as alumina interposed therebetween. The intermediate layer made of an insulating material such as alumina serves to electrically separate the sensor lines and the like. The intermediate layer is formed with a predetermined thickness between the surface of the base material and the sensor line or the like (conductive film) by adopting a method such as the CVD method.

A specific method of forming the intermediate layer is as follows. When the intermediate layer is made of alumina, the base material of the throw-away tip is
It is placed in a heat-resistant alloy reaction container in which the temperature is set to about 1050 ° C. and the pressure is set to 6.5 kPa. Next, 40 to 501 / min of H ₂ and 1/31/3 of CO ₂ are placed in the reaction vessel.
min, and the AlCl ₃ 0.5~21 / min was flowed for 2 hours, to generate a Al ₂ O _3, it is performed by depositing on the surface of the base material.

If the thickness of the intermediate layer is less than 1 μm, an electrical short circuit occurs between the base material and the sensor line, etc., and the sensor line can accurately detect the degree of wear and breakage of the throw-away tip. There is a risk of not being able to do it. When an intermediate layer having a thickness of more than 10 μm is formed, stress is internally generated inside the intermediate layer during formation,
Due to the inherent stress, the bonding strength of the intermediate layer to the base material becomes weak, and there is a risk that the intermediate layer is easily separated from the surface of the base material even when a small external force is applied. Therefore, the intermediate layer preferably has a thickness in the range of 1 μm to 10 μm.

Next, an embodiment of wear detection using the throw-away tip with a wear sensor of the present invention will be described. Example 1 An alumina sintered body was used as the base material of the throw-away tip, and the arrangement shape of the sensor lines as shown in FIG. 1 was formed of a conductive film made of TiN. At this time,
Sensor line film thickness 0.3μm, width 0.186μm
And This throw away tip with wear sensor is mounted on the holder shown in Fig. 5, and a round bar-shaped work material made of SCM435 (chromium molybdenum steel) is continuously cut under the following processing conditions with an NC lathe to measure the resistance of the sensor line. The value was measured. The result is shown in the graph of FIG.

Processing conditions: Cutting speed V = 200 m / min Depth of cut d = 2 mm Feed f = 0.2 mm / rev Wet work material SCM435 (chromium molybdenum steel): round bar In the graph of FIG. The change in the measured resistance value is shown, the vertical axis shows the magnitude of the resistance value, and the horizontal axis shows the passage of time. In this graph, it can be seen that the resistance value greatly jumped 16.6 minutes after the start of processing. For reference, the damage condition (wear width) of the cutting edge 11 minutes and 18 minutes after the start of processing was measured and shown as a linear broken line. This broken line shows the change over time in the wear width of the cutting boundary portion.

From this measurement, 16.6 minutes after the resistance value jumped greatly from the start of processing, the sensor film width (0.186
wear progressed up to μm), and at this point it could be clearly detected that the wear reached the limit wear width. Example 2 The same throw-away tip used in Example 1 was mounted on the holder shown in FIG. 5, and a four-grooved round bar-shaped work material made of SCM435 (chromium molybdenum steel) was NC.
Intermittent cutting was performed on a lathe under the following processing conditions, and the resistance value of the sensor line was measured. The result is shown in the graph of FIG.

Machining conditions: Cutting speed V = 200 m / min Depth of cut d = 2 mm Feed f = 0.2 mm / rev Wet work material SCM435 (Chromium molybdenum steel): Round bar with 4 grooves Results at 40 or more seconds The resistance jumped to infinity. When the cutting was stopped and the cutting edge of the throw-away tip was confirmed, a cutting edge ridge defect was found. From this experiment, when it became unusable due to cutting edge deficiency,
The sensor line was also broken, and as a result, the cutting edge ridge defect of the throw-away tip could be clearly detected from the abnormal resistance value measured.

Example 3 A silicon nitride sintered material was used as the base material of the throw-away tip, and the arrangement shape of three parallel lines shown in FIG. 4 was changed to Ti.
It was formed of a conductive film made of N. At this time, the film thickness of the sensor line is 0.3 μm, and the width of each sensor line is 0.1 μm.
It was 46 mm. The distance between the pair of adjacent sensor lines is 0.01 mm. This throw away tip with wear sensor is attached to the holder shown in FIG.
A round bar-shaped workpiece made of 50 (gray cast iron) was continuously cut on an NC lathe under the following processing conditions, and the resistance value of the sensor line was measured . Processing conditions: Cutting speed V = 200 m / min Cutting depth d = 2 mm Feed f = 0.2 mm / rev Wet processing work material FC250 (gray cast iron): Round bar

The measured resistance value changed stepwise as the machining time passed, and finally increased to infinity. From this, as the wear of the chip progresses, each sensor line is broken, and the resistance value increases stepwise. Then, when the third sensor line was broken (about 10 minutes), the resistance value jumped to infinity, the entire sensor line was worn, and it was detected that the cutting edge of the throw-away tip had reached the wear limit wear width. . Although the embodiments of the present invention have been described specifically and in detail above, the present invention is not limited to the embodiments and various modifications can be made within the scope of the claims.

[Brief description of drawings]

FIG. 1 is a perspective view of a throw-away tip according to an embodiment of the present invention seen from the front upper side, and B is a perspective view of the throw-away tip seen from the front lower side.

[Fig. 2] 4 provided on the seating surface of the throw-away tip
It is a top view which shows the modification of a pair contact area.

FIG. 3 is a perspective view showing another embodiment of the sensor line.

FIG. 4 is a perspective view showing still another embodiment of a sensor line.

FIG. 5 is a schematic perspective view showing how the throw-away tip according to the embodiment of the present invention is attached to a holder.

6A to 6E are a plan view and a front view, respectively, showing examples of various shapes of a throw-away tip to which the present invention can be applied.

FIG. 7 is a graph showing the test results of Example 1.

FIG. 8 is a graph showing the test results of Example 2.

[Explanation of symbols]

1 Throw-away tip 2 base material 5 rake face 6 Seating surface 8 flank 9 cutting edge 10 corners 12,123,125 sensor lines 13,14 contact area 15,16 connection line 17 Folded line 18 Folding part

Claims (5)

(57) [Claims] 1. A base material having a substantially flat plate shape, a rake surface on one surface of the base material, a seating surface on the other surface of the rake surface and the back to back,
And flanks are respectively formed on a plurality of side surfaces that intersect the rake surface and the seating surface, and a cutting edge is formed by a cross edge of the rake surface and each flank, and the rake surface and the adjacent 2
In a throw-away tip in which a corner portion that can be used for cutting is formed by an intersection of two flanks, the number of the corner portions is N (N is a natural number of 2 or more), and the N corner portions are formed. , Respectively, the sensor line of the conductive film extending along the cutting edge so as to surround the corner,
The seating surface is provided with two contact regions that are electrically insulated from the base material and that form a pair that can be electrically connected to a predetermined circuit. N pairs are formed, and the throw-away tip has a rake face on one side.
Functioning as a seat, the other surface becomes the seating surface and the other surface
One surface becomes the seating surface when it functions as a rake face
It is a chip that can be used on both sides, and the corner portion has one surface side and the other surface side.
Each of the N contact areas is formed on the one surface and the other surface.
It is, be provided N to a contact region of the N pairs of connecting lines N pairs for connecting the ends of the N corner portions of the sensor line, respectively, on the surface of the base material, to the base material Are electrically isolated from each other, and one of the two connecting lines forming a pair is
The sensor line is separated from the sensor line by a predetermined distance and is parallel to the sensor line.
Characterized that you have include folding line extending in the throw-away tip with wear sensors. 2. One of the N pairs of contact regions is electrically independent of each other, and the other of the N pairs of contact regions is provided with N electrically connected. wherein the is, claim 1
Serial mounting of the wear sensor with a throw-away tip. 3. The N pairs of contact regions provided on one surface of the throw-away tip and the N pairs of contact regions provided on the other surface have exactly the same arrangement shape. The throw-away tip with a wear sensor according to claim 1 or 2 . 4. The connection line extends to the flank and the seating surface, and the connection line of the flank is connected to the sensor line at a predetermined inclination angle. The throw-away tip with a wear sensor according to any one of 3 above. 5. The throw-away tip with wear sensor according to claim 4 , wherein the connection line is formed in a rotationally symmetrical positional relationship with respect to the center of the flank.