JP2002292505A - Cutting tool with sensor and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] (With correction) [PROBLEMS] To provide a cutting tool with a sensor capable of detecting a wear amount of the cutting tool with high accuracy and a method of manufacturing the cutting tool. SOLUTION: An insulating layer 7 is provided on a surface of a conductive base material 8,
A cutting tool for forming a sensor circuit made of a conductive film 6 on the surface thereof and determining the life of the tool from a change in electric resistance due to wear of the circuit, and irradiating a laser beam to partially cut the insulating layer in the thickness direction. In a manufacturing method in which a sensor portion is formed by partially removing a conductive film while leaving it, a thickness A of an insulating layer and a thickness B of an insulating layer in a portion where no conductive film is provided have a relationship of A ≧ B ≧ 0.1 μm. To do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool and a method of manufacturing the same, and more particularly to a cutting tool with a sensor provided with a sensor circuit for detecting the life of the cutting tool and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a cutting tool having a cutting edge formed by an intersection between a rake face and a flank, the magnitude of wear of the flank is a criterion for determining the tool life. Therefore, it is very important to quickly observe the amount of wear of the flank in the in-process during the cutting process in order to maintain high-precision processing.

However, it is very difficult in the working environment to directly observe the wear of the tool during machining. Therefore, if you want to stop the cutting process once, remove the tool and observe it with a tool microscope, etc., or if you want to know the amount of wear in process during machining,
Other phenomena accompanying the tool wear (such as changes in cutting force and vibration) are detected by a sensor installed near the processing point of the machine tool, and the wear amount is estimated.

However, it has been difficult to obtain a quantitative amount of abrasion in the in-process, and sufficient sensitivity and reliability for abrasion detection have not been obtained.

Conventionally, there has been proposed a method of automatically judging the tool life by detecting the wear amount of the cutting edge portion of the cutting tool. When applied to conductive cutting tools, it has been proposed to use a conductor path buried in an insulating layer, and to detect critical wear and breakage by using a signal for interrupting during a cutting process as a trigger. (See JP-A-62-88552).

In these tools, as a method of manufacturing a sensor circuit, a method of forming a sensor circuit by a printing method, a photoetching method, a lift-off method, or the like is described. However, all of these tools are not practical because of low productivity.

[0007] Further, there has been proposed a laser processing method which has a high productivity, a high processing accuracy, and a high degree of freedom in circuit change. However, it has been difficult to produce a circuit capable of stably exhibiting the sensor function even by the laser processing method.

This is because, in principle, when the energy is large, the laser processed portion is vaporized, and when the energy is small, the laser processed portion is melted. For this reason, as shown in FIG. 3, when the conductive base material 3 is applied to a tool in which the conductive base material 3 is covered with the insulating layer 2, if the entire thickness of the insulating layer 2 is removed by laser processing, the conductive base material 3 and the conductive base material 3 are electrically connected to each other. A phenomenon in which a molten portion remains or does not remain between the film 1 and the film 1 may occur.
And the conductive film 1 were found to be short-circuited. In FIG. 3, reference numeral 4 denotes a portion removed by laser processing, and reference numeral 5 denotes a molten portion. The conductive film 1 and the conductive base material 3 are short-circuited via the molten portion 5. As a result, the sensor circuit cannot function properly, and the reliability of the sensor tool is low.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in a cutting tool with a sensor according to the present invention, an insulating layer is provided on a surface of a conductive base material, and a conductive material is provided on the surface. In a cutting tool with a sensor in which a sensor circuit made of a film is formed, the thickness A of the insulating layer in a portion where the conductive film is formed and the thickness B of the insulating layer in a portion where the conductive film is not formed are A ≧ B ≧ 0. .1 .mu.m.

According to a second aspect of the present invention, an insulating layer and a conductive film are formed on a surface of a conductive base material, and the conductive film is partially removed to form a sensor circuit. In the method for manufacturing a cutting tool with a sensor, the conductive film is irradiated with a laser beam to partially remove the conductive film while partially leaving the insulating film in a thickness direction.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described by taking a throwaway tool as an example, but application to a drill or the like is also possible.

FIG. 1 is a cross-sectional view showing one embodiment of a cutting tool with a sensor according to claim 1, 6 is a conductive film, 7 is an insulating layer of a conductive film portion, 8 is a conductive base material, and 9 is a laser. The portion 11 removed by the processing is the insulating layer of the portion where the conductive film is removed.

The conductive base material 8 includes aluminum oxide sintered body, silicon nitride sintered body, cermet, cemented carbide,
Cubic boron nitride sintered body (CBN / cubic Bo)
ron nitride), diamond sintered body (PC
D / Polycrystalline Diamond
d) and a PVD method and / or CVD
Coating tools coated with one or more hard films of one or more of carbides, nitrides, carbonitrides, and oxides of Group 4a, 5a and 6a elements of the periodic table can be used.

As the aluminum oxide sintered body, Ti
2 to 40% by weight of C, 0.01 to 5% by weight of at least one of oxides of Fe, Ni and Co, and the balance being Al ₂ O ₃
Also, an aluminum oxide-based sintered body composed of unavoidable impurities can be used.

As the silicon nitride sintered body, Al is Al ₂
1.5 to 10 mol% in terms of O _{3, 30 to} 80 mol% of carbides, nitrides, and carbonitrides of Ti, the balance being silicon nitride and rare earth oxides of 10% by weight or less based on silicon nitride, And a silicon nitride-based sintered body having a ratio of 10 mol% or less in terms of SiO ₂ can be used.

The cermet contains Ti in an amount of 50 to 80% by weight in terms of carbide, nitride or carbonitride, and a Group 6a element of the periodic table in an amount of 10 to 40% by weight in terms of carbide. Hard phase components 70 to 9 having an atomic ratio represented by (carbon + nitrogen) of 0.4 to 0.6.
And TiCN-based cermets comprising 0% by weight and 10 to 30% by weight of a binder phase component comprising an iron group metal.

Cemented carbides include those composed of a hard phase and a binder phase, and the hard phase includes tungsten carbide,
Alternatively, tungsten carbide is formed by substituting 5 to 15% by weight of a carbide, nitride, or carbonitride of a metal of Groups 4a, 5a, and 6a of the periodic table, and the binder phase mainly includes an iron group metal such as Co. As a component, it is contained in a proportion of, for example, 5 to 15% by weight based on the total amount.

A hard coating film (not shown) may be formed on the surface of the conductive base material 8. As such a coating film, a carbide, nitride, or carbonitride of Ti is 0.1 to 10 μm in thickness, and an oxide of Al is 0.1 to 1 μm in thickness.
0 μm and a thickness of TiAl nitride of 0.1 to 10 μm. One or more of these hard films may be coated on the conductive base material 8 such as a cemented carbide, cermet, or ceramic.

The insulating layer 7 is formed by a CVD method,
PV for ion plating, sputtering, vapor deposition, etc.
D method, plating method, and the like. For example, an aluminum oxide film having a thickness of 0.6 to 10 μm is formed on the surface of the base material 8 by a sputtering method. The reason why the thickness of the insulating layer 7 is set to 0.6 μm or more is that, when the insulating layer 7 is removed by laser processing described later, a variation of about 0.5 μm occurs in the thickness direction, and the conductive base material 8 and the conductive base material 8 serve as the insulating layer 7. This is because at least 0.1 μm or more is required to prevent a short circuit with the film 6. On the other hand, if the thickness exceeds 10 μm, the cutting performance (particularly, fracture resistance) is adversely affected.

This insulating layer 7 is formed by a sputtering method in an Ar atmosphere. When the insulating film 7 is formed of aluminum oxide, the film forming conditions include pre-sputtering for 1 minute or more, etching of the base material for 1 minute or more, and pre-sputtering of the target for 1 minute or more in order to remove dirt on the target.
After performing the process for at least 200 minutes, the process is performed for 200 minutes or less depending on the film thickness.

For example, an aluminum oxide film having a thickness of 0.6 to 10 μm may be formed on the surface of the base material 8 by using the CVD method. The reason why the thickness is set to 0.6 to 10 μm is the same as the reason described above. For example, H ₂ is used as a carrier gas, and CO ₂ , HCl, or AlCl ₃ is used as a reaction gas, for example. The film forming temperature is, for example, 850 to 1100 ° C., and the furnace pressure is, for example, 40 to 300 mbar. The material of these insulating layers 7 is aluminum nitride, silicon nitride,
An insulating material such as zirconium oxide or titanium oxide may be used.

The conductive film 6 is made of Ti, Zr, V, Nb, T
a, Cr, Mo, W, etc. periodic table 4a, 5a, 6a group metal, iron group metal such as Co, Ni, Fe or metal material such as Al, 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 carbides, nitrides, carbonitrides, (Ti, Al) N, and the like of metals of Groups 4a, 5a, and 6a of the periodic table such as N and CrCN. Among them, TiN has a strong bonding strength to the base material of the throw-away tip, does not react with the work material, the electric resistance value of the sensor always shows a predetermined value, and indicates the degree of wear of the throw-away tip and the occurrence of chipping. Can be accurately detected, the formation of scratches due to reaction products on the work surface of the work material can be effectively prevented, the oxidation resistance is excellent, and the change in the electrical resistance value of the sensor due to the formation of oxides In addition, it can be suitably used for the reason that the wear degree of the throw-away tip and the presence / absence of occurrence of chipping can be accurately detected.

The conductive film 6 is coated to a predetermined thickness on almost the entire surface of the conductive base material 8 on which the insulating layer 6 is formed by employing a PVD method such as CVD, ion plating, sputtering, vapor deposition, or plating. Be worn. After that, the conductive film 6 is processed into a predetermined pattern by laser processing.

When the thickness of the conductive film 6 is less than 0.05 μm, the bonding to the surface of the conductive base material 8 becomes weaker and the electric resistance of the sensor becomes higher. It becomes difficult to detect the defect accurately. When the conductive film 6 having a thickness of more than 20 μm is formed, a large stress is generated inside the conductive film 6 during the formation, and the remaining stress causes the bonding of the conductive film 6 to the surface of the base material 8 to be weak.

Thereafter, a sensor circuit is manufactured. To manufacture the sensor circuit, a sensor pattern is formed on the rake face and flank face of the cutting edge by a method such as YAG laser processing so as to be parallel to the cutting edge ridge line. The sensor width is generally 0.01 to
It may be 0.5 mm, but can have any width depending on the life setting. A part of the conductive film 6 is removed by laser processing, and the thickness (B) of the insulating layer 11 at the portion where the conductive film 6 is removed is set to be equal to or less than the thickness (A) of the insulating layer 7 at the portion where the conductive film 6 is formed. A ≧ B, and the thickness (B) of the insulating layer 11 at the portion where the conductive film 6 is removed is 0.1 μm or more, preferably 1 μm.
By leaving m or more, a short circuit between the conductive base material 8 and the conductive film 6 can be prevented.

This allows the sensor tool to function normally. Regarding the laser processing conditions, the optimum value changes depending on the film quality of the conductive film 6 and the insulating layer 7 and the film thickness to be removed. The thickness of the insulating layer 7 can be controlled to an optimum value by changing the frequency of the laser pulse, the drawing speed, and the laser output in various ways. This makes it possible to manufacture a stable sensor tool having good electrical insulation.

[0027]

EXAMPLES-Example 1-The following samples were prepared. Al ₂ as conductive base material 8
O ₃ were used -TiC-based ceramic base material. Conductive base material 8
As a first layer, a 5 μm-thick aluminum oxide film was formed as an insulating layer 7 insulating the conductive film 6 from the conductive film 6.
The sputtering apparatus uses a high-frequency sputtering apparatus to perform pre-sputtering in an Ar atmosphere for 3 minutes, etching of a base material for 12 minutes, and pre-sputtering of a target for 1 minute.
Film formation was performed for 5 minutes and for 100 minutes. Then, the atmosphere in the furnace was set to 4 Pa for nitrogen and the base material temperature was set to 50 by the AIP method as the conductive film 6.
The TiN film was formed to a thickness of 1 μm at 0 ° C. for a film forming time of 15 minutes. Next, as shown in FIG. 1, laser processing was performed halfway through the insulating layer 7 using a YAG laser device. The frequency of the laser pulse is 35 kHz and the drawing speed is 100
mm / sec. Table 1 shows other laser processing conditions and the thickness and electric resistance of the insulating layer 7 at the portion removed by the laser processing. FIG. 2 shows a method of measuring the electric resistance value. In FIG. 2, 12 is a conductive film, 13 is an insulating layer, 1
4 is a conductive base material and 15 is a tester.

The thickness of the insulating layer 7 in the portion where the conductive film 6 is left is 5 μm, and the thickness of the insulating layer 7 in the portion where the conductive film 6 is removed is 5 μm for Sample 1, 3 μm for Sample 2, and 0 μm for Sample 3. Table 1 shows the electrical resistance values when the sample 4 was 0.1 μm and the sample 4 from which the insulating layer 7 was completely removed was 0 μm.

[0029]

[Table 1]

As a result, when the thickness of the insulating layer 7 in the portion of the conventional sample 4 from which the conductive film 6 was removed was 0 μm, the electrical resistance was short-circuited to 0.3Ω, and the sample 1 of the present invention was used. 2 and 3 have higher electric resistance than the prior art,
A stable sensor tool with good electrical insulation between the conductive base material 8 and the conductive film 6 could be manufactured.

[0031]

As described above, according to the cutting tool with the sensor according to the first aspect, the thickness A of the insulating layer in the portion where the conductive film is formed and the thickness B of the insulating layer in the portion where no conductive film is formed. A ≧
Since the relationship of B ≧ 0.1 μm is satisfied, a short circuit between the conductive film portion and the conductive base material portion can be prevented, and the sensor tool can function stably and normally.

Further, according to the method for manufacturing a cutting tool with a sensor according to claim 2, the conductive film is irradiated with a laser beam,
Since the conductive film is partially removed while partially leaving the insulating film in the thickness direction, a cutting tool with a sensor having high productivity, high processing accuracy, and high flexibility in circuit change can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cutting tool with a sensor according to the present invention.

FIG. 2 is a diagram showing a method for examining electrical insulation.

FIG. 3 is a cross-sectional view of a conventional tool with a pad.

[Explanation of symbols]

8: conductive base material, 9: part removed by laser processing, 1
0: Fused portion, 11: Insulating layer portion of conductive sensor film removed portion

Claims (2)

[Claims] 1. A cutting tool with a sensor, in which an insulating layer is provided on a surface of a conductive base material and a sensor circuit made of a conductive film is formed on the surface, a thickness A of the insulating layer in a portion where the conductive film is formed. And a thickness B of the insulating layer in a portion where the conductive film does not exist has a relationship of A ≧ B ≧ 0.1 μm. 2. A method for manufacturing a cutting tool with a sensor, wherein an insulating layer and a conductive film are formed on a surface of a conductive base material, and the conductive film is partially removed to form a sensor circuit. A method for manufacturing a cutting tool with a sensor, comprising irradiating a laser beam to partially remove the conductive film while partially leaving the insulating film in a thickness direction.