JP6504524B2 - Metal cutting method - Google Patents

Description

  The present invention relates to a method of cutting a metal that is difficult to cut such as titanium alloy and aluminum alloy.

  The main components of aircraft structural materials (structural materials) are metallic materials, and most of them are made of aluminum alloys. In addition, heat-resistant alloys such as titanium alloy and stainless steel are used at places where temperature may become higher in the airframe structure, for example, jet exhaust points and afterburners. Furthermore, as the speed of the aircraft increases in the future, aerodynamic heating lowers the strength of conventional aluminum alloys. Therefore, in the future, it is expected that harder titanium alloys and stainless steels will be used as structural materials as the main body of the airframe structure. These structural materials that make up the aircraft fuselage are drills for fastening metal materials or metal materials and structural materials of other materials such as CFRP (Carbon fiber reinforced plastic) with bolts. It is necessary to do the drilling process by

  Several techniques have already been proposed for the above-described drilling of the metal material. For example, since titanium alloy is a hard-to-cut material, the drilling life is very short. In order to solve such problems, methods of spraying cutting fluid and processing, and methods of reducing load on the drill bit by changing the shape of the drill bit and avoiding reduction in drilling life have been exemplified (for example, Patent Document 1 and Patent Document 2).

  In addition, a method of using an entry sheet for cutting work made of a metal foil and / or a resin sheet is also proposed in the drilling of a metal material (see, for example, Patent Document 3).

  On the other hand, in the field of printed wiring boards different from metal processing, a method of drilling using an entry sheet has been proposed (see, for example, Patent Document 4). However, the material used for the printed wiring board consists of organic matter, glass cloth and thin copper foil, the load on the drill bit is small, and its processability is compared with difficult-to-cut metals such as titanium alloy and CFRP. Very easy.

Unexamined-Japanese-Patent No. 2006-150557 Japanese Patent Application Publication No. 2002-210608 International Publication No. 4157570 pamphlet JP 2003-175412 A

  Drilling of metal material is done using a drill, but when drilling a metal using a drill, frictional heat is generated between the rotating drill bit and the metal, and the temperature around the processing hole rises locally Do. Therefore, when the number of machining holes is large, as the number of machining holes increases, heat is accumulated in the drill bit and the metal which is the material to be cut. In the case of a metal having a low thermal conductivity, the temperature around the processing hole increases because the heat release is insufficient. At this time, when the temperature of the metal rises, the metal is softened, so that burrs are generated at the outlet portion through which the drill bit of the processing hole passes. In addition, metal processing scraps may be welded to the drill bit by the processing heat, and an excessive load may be applied to the drill bit to stop the processing apparatus. As described above, in the conventional cutting method, there is a possibility that a quality problem may occur in the processed hole due to the heat accumulation during the drilling.

  Furthermore, in the case of wet processing using conventional cutting oil or the like, a cleaning process is required at the end of cutting in order to prevent heat buildup of such processing points and drill bits. Furthermore, if oil remains around or inside the processing hole, there is a possibility that deterioration of the screw which is a fastener when fastening with the through hole or loosening may occur in the fastening portion, and these problems are fatal May lead to

  Under such circumstances, in the production of a structure using a titanium alloy material for aircraft, etc., particularly, high quality drilling is required, and the above-mentioned drilling life and the different material from metal materials are different. It will be extremely important to solve the problems such as floating that occur between them and the problems related to burrs mentioned above.

  On the other hand, in the cutting method of Patent Document 3, in order to suppress burrs (back burrs) generated on the drill bit outlet side of the metal material, an entry sheet for cutting processing using metal foil and / or resin sheet is used Furthermore, although a method of cooling a cutting portion and / or a cutting tool with cold air is disclosed, this method blows away processing wastes generated during cutting, so that safety and working environment can be achieved. There is a problem with

  As mentioned above, although the workability improvement of the metal in which drilling is difficult is examined from the aspect of a cutting tool or the cutting method, the effect is still inadequate.

  Therefore, the object of the present invention is that, in metal cutting with difficult-to-machinability, the temperature of the drill bit can be lowered during cutting compared to conventional metal drilling, and the outlet through which the drill bit penetrates It is an object of the present invention to provide a cutting method which can suppress the generation of burrs in a part and can provide a high quality machined hole.

  The present inventors conducted various studies in order to solve the above problems, and as a result, when cutting a metal (for example, a titanium alloy) that is difficult to cut easily, it lubricates the approach surface of the drill bit that is the cutting tool. By arranging the entry sheet including the resin sheet having flexibility and controlling the rotation speed and feed rate of the drill bit within a specific range, the heat storage of the drill bit at the time of cutting is suppressed, as a result, the drill It has been found that the height of the burr around the cutting point on the outlet side of the bit is greatly suppressed, and a high-quality drilled hole can be obtained, and the present invention has been completed.

That is, the present invention is as follows.
(1) A method for cutting a metal having a Vickers hardness of 100 or more using an entry sheet for cutting, wherein the metal for entry is a cutting entry sheet containing at least a resin sheet as the entry sheet for cutting, and the metal The cutting entry sheet is placed on the surface where the drill bit, which is a cutting tool, enters, and the rotation speed of the drill bit is 100 rpm or more and 720 rpm or less, and the feed rate of the drill bit is 5 mm / min. A metal cutting method, wherein the cutting is performed by controlling the surface temperature of the drill bit at cutting to 200 ° C. or less at 50 mm / min or less and at a cutting temperature.
(2) The metal cutting method according to (1), wherein the rotational speed of the drill bit is 100 rpm or more and 380 rpm or less.
(3) The metal cutting method according to (1) or (2), wherein the metal is a titanium alloy.
(4) The metal cutting method according to (3), wherein the material of the titanium alloy is Ti-6Al-4V.
(5) The metal cutting method according to any one of (1) to (4), wherein the cutting is a process for forming a through hole.
(6) The metal cutting method according to any one of (1) to (5), wherein the material of the drill bit is a cemented carbide.
(7) The metal cutting method according to any one of (1) to (6), wherein the diameter of the drill bit is 2 mmφ or more and 7 mmφ or less.
(8) The metal cutting method according to any one of (1) to (7), wherein the resin sheet contains a water-soluble resin.
(9) The metal cutting method according to any one of (1) to (8), wherein the resin sheet contains a non-water-soluble resin.
(10) The metal cutting method according to any one of (1) to (9), wherein the resin sheet contains a solid lubricant.
(11) The metal cutting method according to any one of (1) to (10), wherein the thickness of the resin sheet is 0.1 mm or more and 20 mm or less.
(12) The metal cutting method according to any one of (1) to (11), wherein the cutting entry sheet further has a metal foil on at least one side of a resin sheet.
(13) The metal cutting method according to any one of (1) to (12), wherein the cutting entry sheet further has an adhesive layer on a surface in contact with the metal to be cut.

  According to the metal cutting method of the present invention, the temperature of the drill bit at the time of cutting can be lowered in cutting of a metal (for example, titanium alloy) which is difficult to cut, compared to the conventional processing method. And, it is possible to suppress the occurrence of burrs at the outlet part through which the drill bit passes. As a result, it is possible to provide a cutting hole of higher quality than the conventional method.

It is a figure showing the relationship between the rotation speed of a drill bit, and the height of the burr | flash around a cutting hole in Examples 1-3 and Comparative Examples 1-15. It is a figure showing the relationship between the feed rate of a drill bit, and the height of the burr | flash around a cutting hole in Examples 1-3 and Comparative Examples 1-15. It is a figure showing the relationship between the rotation speed of a drill bit and drill bit surface temperature in Examples 1-3 and Comparative Examples 1-15. It is a figure showing the relationship between the feed rate of a drill bit and drill bit surface temperature in Examples 1-3 and Comparative Examples 1-15. It is a figure showing the relationship between the height of the burr | flash around a cutting hole, and the surface temperature of a drill bit in Examples 1-3 and Comparative Examples 1-15.

  Hereinafter, embodiments of the present invention (hereinafter also referred to as “the present embodiment”) will be described. In addition, the following embodiment is an illustration for demonstrating this invention, and this invention is not limited only to the embodiment.

  The present invention is a method of cutting a metal having a Vickers hardness of 100 or more using an entry sheet for cutting (hereinafter sometimes referred to simply as an entry sheet in the present specification). That is, the present embodiment uses the cutting entry sheet having at least a resin sheet as the cutting entry sheet, and performs the cutting on the surface where the drill bit, which is the cutting tool, enters the metal to be cut. The entry sheet is placed, and the rotation speed of the drill bit is 100 rpm or more and 720 rpm or less, and the feed rate of the drill bit is 5 mm / min or more and 50 mm / min or less, and the surface of the drill bit at the time of cutting It is a metal cutting method characterized in that the cutting is performed by controlling the temperature to 200 ° C. or less.

<Cutting object>
In the present embodiment, the metal to be cut is not particularly limited as long as the Vickers hardness is 100 or more. The Vickers hardness is a scale that represents the hardness of a substance, and is a hardness defined from the ratio of load to the surface area of a depression when a square pyramidal diamond indenter is pressed into a sample. It is widely applied to metal materials in general, and is defined by the method of JIS Z 2244: 2009. The measuring apparatus is not particularly limited as long as it is a general apparatus. A metal having a Vickers hardness of 100 or more is generally used as a structural material, and the type thereof is not particularly limited, and examples thereof include metal materials used for materials for construction of aircraft fuselages. Among them, metals with high strength, such as aluminum alloy, magnesium alloy, titanium alloy, low alloy steel, stainless steel, heat-resistant alloy, are preferable as metals to be cut by which the cutting method of the present embodiment can be applied. . This is because the higher the strength of the metal, the greater the degree of temperature rise due to frictional heat at the time of cutting, so the amount of burr generation tends to be large, and the cutting method of the present embodiment is effective. The metal to be cut may be used alone or in combination of two or more.

  Further, among the above-mentioned metals, a titanium alloy is more preferable as a metal to be subjected to the cutting process to which the cutting method of the present embodiment can be applied. Furthermore, among the titanium alloys, Ti-6Al-4V, which is made of titanium, aluminum and vanadium and has higher strength, is particularly preferable. Titanium alloy is a material that is twice as strong as aluminum alloy in tensile strength and is excellent in corrosion resistance and heat resistance, but it has high hardness and low thermal conductivity, so burrs due to temperature rise due to frictional heat There is a feature that the amount of generation is likely to be extremely large. Specifically, the tensile strength of Ti-6Al-4V is 980 MPa, and the Vickers hardness is 320. In addition, Ti-6Al-4V is an international standard which shows the composition of a titanium alloy, and is one of the titanium alloys. Therefore, in the prior art, when drilling a titanium alloy, a large load is applied to the cutting tool, so it is necessary to improve the processing conditions, the shape of the cutting tool, etc. However, the cutting method of this embodiment Then, cutting can be performed without devising the processing conditions and the shape of the cutting tool.

  The object of cutting to which the cutting method of the present embodiment can be applied is not limited to only metal, but may be a material in which metal and a fiber reinforced composite are combined, so that metal and fiber reinforced composite are in contact with each other. It may be a stacked material. The cutting method of the present embodiment can also be applied to, for example, co-drilling of materials stacked so that a metal and a carbon fiber composite material such as CFRP contact each other. The manner of superposition is not particularly limited. Specifically, a method of overlapping and fixing a metal and a fiber reinforced composite using a jig, a method of overlapping and fixing a metal and a fiber reinforced composite through an adhesive layer, and the like are listed. Be In general, for example, it is known that optimum drilling conditions for titanium alloy and CFRP are largely different. For example, when performing drilling, in titanium alloy drilling, a high-speed feed amount with low-speed rotation is suitable in order to suppress the temperature rise of the drill bit and to suppress the wear of the drill bit blade. In particular, such a drilling condition is required in a heat-resistant diamond-coated drill. On the other hand, for drilling of CFRP, low speed feed amount is suitable at high speed rotation. With respect to such contradictory drilling conditions, in an actual machining site, the drilling conditions are changed at the boundary between the titanium alloy and the CFRP, or drilling is performed under the same conditions in which the center is taken. Moreover, in order to prevent the temperature rise of a drill, the method of processing, while applying cutting oil, is also taken at the time of the drilling process of the titanium alloy for aircraft use. Among them, in particular, carbon fiber composite materials such as CFRP manufactured by laminating one or two or more prepregs in which carbon fibers are impregnated with a matrix resin, and heat molding or heat and pressure molding are worn out. When processing with an advanced drill bit, carbon fiber is cut off in a state of cutting through, so delamination between laminated prepregs tends to occur, resulting in fluffing of carbon fiber at the exit part through which the drill bit penetrates There is a drawback that is likely to occur. However, by using the cutting method of the present embodiment, the temperature rise of the processing location and / or the cutting tool at the time of metal cutting is reduced, so the amount of burrs derived from the metal is reduced, and to the drill bit. By reducing the load and suppressing the wear of the drill bit, there is an effect that the restriction of cutting of the carbon fiber composite material, which is likely to affect the quality of the machined hole by the wear of the drill bit, can be greatly alleviated. In the cutting method according to the present embodiment, the object to be cut is a material overlapped so that the metal and the fiber reinforced composite are in contact with each other, and the fiber reinforced composite is closer to the cutting tool than the metal. It is preferable to arrange and cut so as to be In such a case, the effect of the cutting method according to the present embodiment is more pronounced.

<Cutting method>
The cutting method of the present embodiment uses a drill bit, but the type of cutting is not particularly limited. For example, drilling for forming a through hole, drilling for forming a non-through hole , Cutting, cutting and the like. Above all, a drilling process for forming a through hole is preferable.

  The drill bit that can be used for the cutting method of the present embodiment is not particularly limited as to the diameter, material, shape, and presence or absence of a surface coating, as long as it is generally used. For example, the diameter of the drill bit is preferably 1 mmφ or more and 20 mmφ or less, and more preferably 2 mmφ or more and 7 mmφ or less, which is often used for cutting of aircraft substrates. The material of the drill bit is preferably a cemented carbide produced by sintering hard metal carbide powder. Such cemented carbides are not particularly limited, and examples thereof include metals obtained by mixing and sintering tungsten carbide and cobalt which is a binder. In such a cemented carbide, titanium carbide, tantalum carbide or the like may be added in order to further improve the material properties depending on the purpose of use. On the other hand, the shape of the drill bit can be appropriately selected depending on the conditions of the drilling process, the type and shape of the material to be processed, and the like. The shape of the drill bit is not particularly limited, and examples thereof include the tip angle of the drill bit, the twist angle of the groove, the number of cutting edges, and the like. The surface film of the drill bit can be appropriately selected depending on the conditions of the drilling process, the type and shape of the material to be processed, and the like. The type of preferable surface film is not particularly limited, and examples thereof include diamond coat, diamond like coat, ceramic coat and the like.

  In the cutting method of the present embodiment, an apparatus used for cutting is not particularly limited. Specifically, the number of rotations of drill bit, feed rate of drill bit, drill, such as machining center, frustum, hand drill, etc. A device capable of controlling the bit feed rate is preferable, and a device capable of controlling the drill bit rotation speed, drill bit feed rate, and drill bit feed rate within a range of ± 10% is particularly preferable.

  In the cutting method of the present embodiment, the rotational speed of the drill bit is preferably 100 rpm or more and 720 rpm or less, more preferably 100 rpm or more and 500 rpm or less, and particularly preferably 100 rpm or more and 380 rpm or less. When the rotation speed of the drill bit exceeds 720 rpm, the temperature of the drill bit during cutting increases, the temperature of the metal to be cut increases, and the amount of burrs around the cutting point on the exit side of the drill bit Tends to be excessive. On the other hand, if the rotation speed is less than 100 rpm, the load on the drill bit increases, and wear and breakage of the drill bit tend to be excessive.

  In the cutting method of the present embodiment, the feed rate of the drill bit is preferably 5 mm / min or more and 50 mm / min or less, and more preferably 5 mm / min or more and 25 mm / min or less. When the feed rate of the drill bit exceeds 25 mm / min, the load on the drill bit is increased, and the wear and breakage of the drill bit may be excessive. On the other hand, if it is less than 5 mm / min, the temperature of the drill bit during cutting increases, the temperature of the metal that is the material to be cut increases, and the amount of burrs around the cutting point on the drill bit outlet side is excessive There is a risk of becoming

  In the cutting method of the present embodiment, the surface temperature of the drill bit needs to be controlled to 200 ° C. or less. This is because if the surface temperature of the drill bit at the time of cutting exceeds 200 ° C., the temperature of the metal which is the material to be cut rises, and the amount of burrs around the cutting point on the outlet side of the drill bit becomes excessive Because they tend to Among them, 20 ° C. or more and 200 ° C. or less are preferable, 20 ° C. or more and 180 ° C. or less are more preferable, and 20 ° C. or more and 160 ° C. or less are more preferable. If the surface temperature of the drill bit is less than 20 ° C., the resin sheet contained in the entry sheet does not melt and tends to exhibit a sufficient lubricating action.

  The method of measuring the surface temperature of the drill bit at the time of cutting is not particularly limited. Specifically, the tip of the drill bit penetrating metal which is the material to be cut is photographed using an infrared radiation thermometer (InfReC Themo GEAR G120EX, made by NEC Avio Infrared Technologies Co., Ltd.), and cutting processing from a thermal image There is a method of measuring the surface temperature of the drill bit at the time.

  The cutting method of the present embodiment is performed using a cutting entry sheet including at least a resin sheet described later. Although a cutting entry sheet containing a resin sheet, which can be suitably used in the present embodiment, will be described in detail later, an entry sheet containing a metal foil and a resin sheet is particularly preferable. The reason is that the metal foil has an effect of improving the biting property of the tool tip, and the resin sheet has an effect of improving the lubricity of the resin composition which is a component. That is, an entry sheet including a layered structure in which a metal foil and a resin sheet are laminated is more preferable from the viewpoints of the improvement of the biting property of the tip of the tool and the improvement of the lubricity.

  In the cutting method of the present embodiment, the cutting is performed by arranging a cutting entry sheet on a surface (ingress surface) where a drill bit as a cutting tool enters the metal to be cut. At that time, when using an entry sheet in which both sides of the entry sheet are resin sheet surfaces (for example, an entry sheet made of only resin sheets), the resin sheet surface of the entry sheet is the cutting tool entry surface on the outermost surface to be cut It is preferable to arrange so that it may become and to cut from the resin sheet surface of an entry sheet | seat. In addition, when using an entry sheet in which at least one surface of the entry sheet is a metal foil surface (for example, an entry sheet in which a metal foil and a resin sheet are laminated), the metal foil surface of the entry sheet on the outermost surface to be cut It is preferable to arrange so that it may become a cutting tool approach surface, and to cut from the metal foil surface of an entry sheet | seat.

  Furthermore, when co-piercing a metal and a fiber-reinforced composite material, when using an entry sheet in which both sides of the entry sheet are resin sheet surfaces (for example, an entry sheet consisting only of a resin sheet), the metal and fiber reinforcement are used. It is preferable that the resin sheet surface of the entry sheet be disposed on the outermost surface in a state of being superimposed with the composite material so as to be a cutting tool entry surface, and cutting is performed from the resin sheet surface of the entry sheet. On the other hand, when using an entry sheet provided with metal foil on at least one side of the resin sheet, place the metal foil of the entry sheet in contact with the surface to be cut, and cut from the outermost surface of the entry sheet It is preferable to

  In the cutting method of the present embodiment, the method for bringing the entry sheet into close contact with the metal to be cut is not particularly limited. For example, the entry sheet and the metal to be cut may be a clip or a jig And a method of using an entry sheet in which a layer (adhesive layer) of a compound having adhesiveness is formed on the surface of a resin sheet in contact with a metal as a material to be cut or a metal foil surface. In addition, in this specification, the layer of the compound which has the adhesiveness used in order to fix the metal which is a to-be-cut material, and an entry sheet is defined as an adhesion layer. Among them, it is preferable to use an entry sheet in which an adhesive layer is formed on the surface of a resin sheet in contact with metal which is a material to be cut or on the surface of a metal foil, since fixing with a jig or the like is not necessary. That is, in the cutting method of the present embodiment, the entry sheet preferably further includes an adhesive layer on the surface in contact with the metal that is the material to be cut. The components of the adhesive layer are not particularly limited, and, for example, a thermoplastic resin or a thermosetting resin can be used. Moreover, you may use these together. Preferred thermoplastic resins include urethane resins, acrylic resins, vinyl acetate resins, vinyl chloride resins, polyester resins, and copolymers thereof. Preferred thermosetting resins include phenol resins, epoxy resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, polyurethanes, thermosetting polyimides, and cyanate resins. Among them, acrylic pressure-sensitive adhesives are more preferable because they have the property of being free from adhesion residue to metal which is a material to be cut and being capable of easily adhering at normal temperature. Furthermore, among acrylic pressure-sensitive adhesives, solvent-type acrylic pressure-sensitive adhesives and acrylic emulsion-type pressure-sensitive adhesives (water-based) are particularly preferable. Here, the acrylic adhesive in this specification refers to the composition which has a poly (meth) acrylic acid ester and a tackifier as a main component, unless there is particular notice. Furthermore, if necessary, an anti-deterioration agent such as an antioxidant, or an inorganic filler such as calcium carbonate, talc, or silica may be added to the components of the adhesive layer.

  It will not specifically limit, if it is the well-known method used industrially as a method of forming an adhesion layer on the entry sheet surface. For example, a method of forming by a roll method, a curtain coating method, a spray injection method or the like, a method of forming using a roll, a T-die extruder or the like, and the like can be mentioned. The thickness of the pressure-sensitive adhesive layer is not particularly limited, and the optimum thickness can be appropriately selected depending on the curvature of the metal as the material to be cut and the configuration of the resin sheet and the entry sheet.

  In the cutting method of the present embodiment, a gas of a predetermined temperature may be stably supplied to a cutting portion and / or a cutting tool (drill bit) at a predetermined gas amount. In the cutting method of the present embodiment, it is preferable to perform cutting while cooling a cutting portion and / or a cutting tool using a gas. This is because the amount of burrs around the cutting portion by gas cooling can be reduced.

  The maximum value of the height of the burr around the cutting position on the outlet side of the drill bit obtained by the cutting method of the present embodiment is 0.8 mm or 0.6 mm or less, and the average value is 0.30 mm or less or 0. 0 or less. It can be 20 mm or less.

<Entry sheet for cutting including resin sheet>
As a component of the resin composition used for the resin sheet contained in the entry sheet which can be used for the cutting method of this Embodiment, water-soluble resin and / or water-insoluble resin can be used. These resins have a role of improving the lubricity at the time of cutting as a lubricity improving component and a role of improving the processability as a resin sheet forming component. Among them, the water-soluble resin has an effect of improving the dischargeability of cutting chips at the time of cutting due to the lubricity of the resin. Moreover, since the surface hardness of the resin sheet which made water-soluble resin the component of a resin composition is moderate softness, it also has the effect of reducing the processing load of a tool. Furthermore, it is also possible to easily remove the resin component adhering to the processing hole after processing. On the other hand, a resin sheet using a non-water-soluble resin as a component of the resin composition has a harder surface hardness of the resin sheet than a resin sheet using a water-soluble resin. It has a good biting property and can be drilled in the designed position. In addition, since the rigidity of the resin sheet is high, the handling property is also excellent. That is, it is preferable that the resin sheet which can be used for the cutting method of this Embodiment contains water-soluble resin and / or water-insoluble resin.

  In the entry sheet containing the resin sheet used in the present embodiment, one category of the water-soluble resin preferable as a component of the resin composition of the resin sheet dissolves 1 g or more in 100 g of water at 25 ° C. and 1 atm. It is a polymer compound. Such water-soluble resin is not particularly limited, but, for example, polyethylene oxide, polyethylene glycol, polypropylene oxide, water-soluble urethane, polyether water-soluble resin, water-soluble polyester, sodium polyacrylate, polyacrylamide, polyvinyl pyrrolidone And polyvinyl alcohols, polyalkylene glycols, esters of polyalkylene glycols, ethers of polyalkylene glycols, polyglycerin monostearates, polyoxyethylene propylene copolymers and derivatives thereof, and at least of these One type can be selected and used. Among them, polyethylene oxide, polyethylene glycol, and polyether-based water-soluble resins are more preferable as components of the resin composition.

In the entry sheet containing the resin sheet used in the present embodiment, another category of the water-soluble resin preferable as a component of the resin composition of the resin sheet is a cellulose derivative. In the present embodiment, “cellulose” is a polymer compound in which a large number of β-glucoses are bonded via glycosidic bonds, and is bonded to carbon atoms at positions 2, 3 and 6 in the glucose ring of cellulose. It means that the hydroxyl group is unsubstituted. In addition, “hydroxyl group contained in cellulose” refers to a hydroxyl group bonded to carbon atoms at positions 2, 3 and 6 in the glucose ring of cellulose. The above-mentioned cellulose derivative is not particularly limited, and examples thereof include hydroxyethyl cellulose and carboxymethyl cellulose. Generally, in hydroxyethyl cellulose, at least a part of the hydrogen atoms of hydroxyl groups contained in cellulose {H- (C ₆ H ₁₀ O ₅ ) _n -OH} is [-(CH ₂ -CH ₂ -O) _m- H] substituted compounds (wherein n and m are integers of 1 or more), and the solubility in water is at least 0.05 g / L at 25 ° C. and 1 atm. Such hydroxyethyl cellulose is synthesized, for example, by adding ethylene oxide to cellulose.

On the other hand, carboxymethylcellulose is a compound in which at least a part of hydrogen atoms of hydroxyl groups contained in cellulose {H- (C ₆ H ₁₀ O ₅ ) _n -OH} is substituted by carboxymethyl group [-CH ₂ -COOH]. (Where n is an integer of 1 or more), and its solubility in water is at least 0.05 g / L at 25 ° C. and 1 atm. Moreover, a part of carboxy group in the said carboxymethyl group may be a sodium salt. Carboxymethylcellulose can be obtained, for example, by adding chloroacetic acid to cellulose.

  In the entry sheet containing the resin sheet used in the present embodiment, the non-water-soluble resin that can be used as a component of the resin composition of the resin sheet is not particularly limited. In the present embodiment, the water-insoluble resin is used as a resin sheet forming component, a lubricity improving component, and the like. The preferable non-water-soluble resin to be used as the resin sheet-forming component is not particularly limited, and examples thereof include urethane resins, acrylic resins, vinyl acetate resins, vinyl chloride resins, polyester resins and their copolymers and phenols. Resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, thermosetting polyimide, cyanate resin, epoxy resin, polyester resin can be mentioned. Moreover, at least one of these can be selected and used as a resin component. On the other hand, preferred non-water-soluble resins to be used as components for improving lubricity are amide-based compounds exemplified by modified polyamide, ethylene bis-stearamide, oleic acid amide, stearic acid amide, methylene bis-stearamide, etc .; lauric acid Fatty acid compounds such as stearic acid, palmitic acid and oleic acid; fatty acid ester compounds such as butyl stearate, butyl oleate, glycol laurate and the like; fats such as liquid paraffin and polyethylene wax Hydrocarbon compounds; higher aliphatic alcohols such as oleic alcohol; styrene homopolymer (GPPS), styrene-butadiene copolymer (HIPS), styrene- (meth) acrylic acid copolymer (eg MS resin) ) And the like It can be exemplified styrene resin. Among these, at least one can be selected and used as a lubricity improving component. Furthermore, in the entry sheet used in the present embodiment, the sheet forming component and the lubricity improving component can be used in combination.

  The thickness of the resin sheet in the entry sheet including the resin sheet used in the present embodiment is the type and thickness of the metal to be processed, the type and cutting method of the cutting tool used for cutting, and is used when drilling It is appropriately selected in consideration of the drill diameter and the like. The thickness of the resin sheet is preferably in the range of 0.1 mm to 20 mm, more preferably in the range of 0.2 mm to 10 mm, and still more preferably in the range of 0.5 mm to 5 mm. When the thickness of the resin sheet is 0.1 mm or more, sufficient cutting stress reduction can be obtained. For example, when drilling processing is performed, the load on the drill becomes small and it is difficult for drill breakage to occur. On the other hand, when the thickness of the resin sheet is 20 mm or less, for example, in the case of drilling, the winding of the resin composition to the drill is reduced, and the resin sheet is less likely to be cracked or the like. In particular, in the target cutting, when the thickness of the resin sheet is within the above range, the resin composition can be inhibited from acting as a binder of cutting powder, and the cutting powder is prevented from staying at the cutting portion Therefore, it is possible to suppress an increase in temperature around the cutting portion, and to suppress welding of a metal to be cut. That is, by optimizing the composition of the resin sheet, the components of the resin composition, and the thickness of the resin sheet according to the object to be cut and the cutting method, the lubricity and the discharge of cutting powder through the processing groove can be optimized. . As described above, in the present embodiment, it is preferable to appropriately control the total thickness of the resin sheet, and a plurality of thin resin sheets can be stacked and used.

  The manufacturing method of the entry sheet containing the resin sheet that can be suitably used in the present embodiment is not particularly limited. For example, after the resin composition is appropriately melted and made liquid, it is applied to a support and cooled The method includes solidifying to form a resin composition layer, and thereafter removing or peeling the support to produce an entry sheet including a resin sheet. In addition, the resin composition is dissolved or dispersed in a solvent to be in a liquid state, then applied to a support, dried, cooled and solidified to form a resin composition layer, and then the support is removed or peeled off, There is also a method of producing an entry sheet containing a resin sheet. At that time, the support is not particularly limited, and a metal foil, a film, a metal roll or the like can be appropriately used. The method for forming the liquid resin composition layer on the support is not particularly limited as long as it is a known method used industrially. For example, a method of forming a resin composition layer on a support by a coating method in which a resin composition is dissolved or dispersed in a solvent and applied using a bar coater, a gravure roll, a die, etc. A method of heating, melting and mixing appropriately using a kneader or other kneading means, and forming a resin composition layer on a support by a roll method, curtain coating method or the like can be mentioned. In addition to the method of forming the resin composition layer on the above-described support, the resin composition is appropriately heated and melted and mixed using a roll, a kneader, or other kneading means, and the resin composition is rolled. A method of forming a resin composition layer having a desired thickness to form a resin sheet can be used without using a support by using a T-die extruder or the like.

  The resin sheet of the entry sheet including the resin sheet used in the present embodiment may have a structure of a single layer resin composition layer or a structure of a plurality of resin composition layers, It is preferable to include the layered structure which laminated | stacked two or more types of resin composition layers from the reason of a characteristic and workability improvement. The combination of the resin composition layer in the entry sheet used in the present embodiment is not particularly limited, but a resin made of a water-soluble resin having a role of improving lubricity at the time of processing and a water-insoluble resin as a lubricity improving component High processing accuracy, long processing life, good handling by appropriately combining the composition layer and the resin composition layer composed of a water-insoluble resin as a resin sheet component having a role of improving positional accuracy and improving rigidity. In terms of sex, it is preferable.

  In the entry sheet including the resin sheet used in the present embodiment, the method for producing a resin sheet containing a layered structure in which a plurality of resin composition layers are laminated is not particularly limited. The method of forming a resin composition layer directly further on at least one side of the resin sheet which consists of a resin composition layer of a layer is mentioned. The method for forming the resin composition layer on one side of the resin sheet is not particularly limited. For example, the resin composition is appropriately melted to be liquid, and then the resin made liquid on the resin sheet as a support The method of apply | coating a composition, cooling, solidifying, and forming a resin composition layer is mentioned. In addition, the resin composition is dissolved or dispersed in a solvent to make it liquid, and then the resin composition made liquid is applied on a resin sheet as a support, dried, cooled and solidified to form a resin composition layer. Methods are also included. It will not specifically limit, if it is the well-known method used industrially as a method of forming the liquid resin composition layer on the resin sheet as a support body. For example, a method of forming a resin composition layer by a coating method in which a resin composition is dissolved or dispersed in a solvent and applied using a bar coater, a gravure roll, a die or the like, a resin composition is used as a roll, a kneader, or the like A method of heating, melting and mixing appropriately using the kneading means of the above, and forming a resin composition layer by a roll method, a curtain coating method or the like can be mentioned.

  As another method for producing a resin sheet containing a layered structure in which a plurality of resin composition layers are laminated, a plurality of resin sheets consisting of a single layer or a plurality of resin composition layers are stacked and pasted using a resin The method of combining, the method of bonding together by the laminating method by heat, etc. are mentioned. The method of bonding using a resin and the method of laminating by heat are not particularly limited as long as they are publicly known methods used industrially.

  In the entry sheet containing the resin sheet used in the present embodiment, an additive can be blended to the resin composition of the resin sheet, if necessary. The type of the additive is not particularly limited, but, for example, surface conditioners, leveling agents, antistatic agents, emulsifiers, antifoam agents, wax additives, coupling agents, rheology control agents, preservatives, mildewproofing agents, oxidation Inhibitors, light stabilizers, nucleating agents, organic fillers, inorganic fillers, solid lubricants, plasticizers, softeners, heat stabilizers, colorants can be used.

  Among them, the solid lubricant has the effect of improving the lubricity of the entry sheet and extending the processing life of the cutting tool. Therefore, in the entry sheet used in the present embodiment, the resin composition forming the resin sheet is solid. It is preferable that it is a resin composition containing a lubricant. That is, it is preferable that the resin sheet which can be used for the cutting method of this Embodiment contains the solid lubricant. The type of solid lubricant is not particularly limited as long as it is a solid having lubricity. For example, graphite, molybdenum disulfide, tungsten disulfide, a molybdenum compound, polytetrafluoroethylene, polyimide and the like are preferable. Among them, graphite is preferable because it has an appropriate hardness, and natural graphite, artificial graphite, activated carbon, acetylene black, carbon black, colloidal graphite, pyrolytic graphite, expanded graphite, and scaly graphite can be suitably used. . Among them, scale-like graphite is particularly preferable because the reduction in wear can be effectively improved by the shape and the particle size thereof. One of these graphites may be used alone, or two or more thereof may be mixed and used.

  The effect of using the solid lubricant in combination with the resin composition in the entry sheet including the resin sheet used in the present embodiment can be described as follows. For example, in drilling processing, the resin composition and the solid lubricant exhibit lubricity by adhering to the surface and grooves of the drill and the side surface of the processing hole of the material to be cut. At that time, solid lubricants have smaller changes in volume and hardness with temperature changes compared to resin compositions, so for example, when drilling is carried out, even if the temperature of the drill or processing point rises , Constant volume and hardness can be maintained. That is, for example, when a solid lubricant is drilled, it can be present between a drill and a workpiece to enhance lubricity and exhibit an effect like a bearing, so that the drill wears out. Has the effect of suppressing

  Among solid lubricants, the reason why graphite is preferred will be described. If the hardness of the solid lubricant described above is low, the bearing effect may be poor and the lubricity may be reduced. On the other hand, if the hardness of the solid lubricant is high, for example, when performing drilling, problems such as wear promotion of the drill tip and chipping of the drill tip may occur. For this reason, as a solid lubricant, graphite having an appropriate hardness is preferable.

  The total amount of solid lubricant used is preferably 5 to 200 parts by mass, more preferably 10 to 100 parts by mass, and more preferably 20 to 100 parts by mass with respect to 100 parts by mass of the resin composition. It is particularly preferred to use parts by weight. When the amount of the solid lubricant used is 5 parts by mass or more, the amount of the solid lubricant relative to the resin composition is sufficient, and the lubricating effect of the solid lubricant is sufficiently developed. On the other hand, when the amount of the solid lubricant used is 200 parts by mass or less, it is economically rational and advantageous for production.

  In the cutting method of the present embodiment, the metal which is the material to be cut is not limited to a flat surface, but may be a curved surface. Therefore, in the entry sheet used in the present embodiment, it is preferable to blend a plasticizer and a softener in the resin composition of the resin sheet as necessary for the purpose of imparting curved surface followability. As the plasticizer and the softener, phthalic acid ester, adipic acid ester, trimetic acid ester, polyester, phosphoric acid ester, citric acid ester, epoxidized vegetable oil, sebacic acid ester and the like are preferable. By blending these plasticizers and softeners, when the entry sheet is disposed on the curved surface of the material to be cut (for example, metal), the stress and distortion on the resin sheet are reduced, and the cracking of the resin sheet is suppressed. Can.

  In the cutting method of the present embodiment, an entry sheet including the above-described resin sheet can be suitably used, but an entry sheet including a metal foil on at least one side of the resin sheet described below is more preferable. This is because, when using an entry sheet provided with metal foil on at least one side of the resin sheet, the rigidity of the metal foil improves the centripetality of the drill when drilling, for example, and holes in the designed position Because it is possible to Further, by arranging the metal foil between the metal to be cut and the resin sheet, there is also an effect of preventing the resin composition of the heat-melted resin sheet from adhering to the upper part and the inside of the processing hole. Among them, an entry sheet including a three-layer structure in which metal foils are provided on both sides of a resin sheet is particularly preferable because the lubricity of the resin sheet can be sufficiently exhibited. For example, when a metal foil is disposed on the outermost layer of the approach surface of the drill when drilling a metal, when cutting a metal to be cut, metal chips to be cut are drilled It is possible to prevent the resin sheet from being rolled up by chips that are wound around and rotate. As a result, the lubricity can be sufficiently exhibited, and the wear reduction effect of the drill is improved.

  Although the thickness of the said metal foil is not specifically limited, 0.05-0.5 mm is preferable and 0.05-0.3 mm is more preferable. When the thickness of the metal foil is 0.05 mm or more, the handling property at the time of production of the entry sheet or at the time of drilling is improved. On the other hand, if the thickness of the metal foil is 0.5 mm or less, discharge of cutting chips generated at the time of cutting becomes easy.

  Although the kind of said metal foil is not specifically limited, Aluminum foil is preferable. This is because, when aluminum foil is used as the metal foil, the aluminum foil has appropriate softness compared to the material to be cut, so, for example, when drilling is performed, it rotates and the drill penetrates When it comes, it has the effect of suppressing the center blurring of the drill, and as a result, it is possible to make an accurate hole for the set coordinates. In addition, by suppressing the center shake of the rotated drill, the movement distance of the drill and the contact area with the material to be cut are reduced, so that the wear of the drill can be reduced.

  Although the aluminum purity in the case of using aluminum foil as metal foil is not specifically limited, It is preferable that it is 95% or more of purity. This is by using high purity aluminum foil as the metal foil, for example, when drilling is performed, reducing the chipping and local wear of the drill due to impurities contained in the aluminum foil, and cutting to the drill This is because the load can be reduced. Such an aluminum foil is not particularly limited, and examples thereof include 5052, 3004, 3003, 1N30, 1N99, 1050, 1070, 1085, 1100, 8021, etc. defined in JIS-H4160.

  The resin sheet which can be used in the entry sheet | seat which equips at least single side | surface of a resin sheet | seat with metal foil can use the resin sheet mentioned above. Moreover, the same thing can also be used for the component which can be added to a resin sheet.

  The method for producing the entry sheet having the metal foil on at least one surface of the resin sheet is not particularly limited. For example, a method for directly forming a single layer or a plurality of resin composition layers on at least one surface of the metal foil And a method of laminating the resin sheet and the metal foil by heat laminating method or the like. The method of directly forming a single layer or a plurality of resin composition layers on at least one surface of the metal foil is not particularly limited. For example, after appropriately melting the resin composition to make it liquid, it can be used as a support The method of apply | coating, cooling, and solidifying the resin composition made liquid form one time or several times on metal foil, and forming the resin composition layer of a single layer or multiple layers is mentioned. In addition, the resin composition is dissolved or dispersed in a solvent to make it into a liquid, and then the resin composition made into a liquid is applied, dried, cooled and solidified one or more times on a metal foil as a support, There may also be mentioned a method of forming a single layer or a plurality of resin composition layers. It will not specifically limit, if it is the well-known method used industrially as a method of forming a liquid resin composition layer on the metal foil as a support body. For example, a method of forming a resin composition layer by a coating method in which a resin composition is dissolved or dispersed in a solvent and applied using a bar coater, a gravure roll, a die or the like, a resin composition is used as a roll, a kneader, or the like A method of heating, melting and mixing appropriately using the kneading means of the above, and forming a resin composition layer by a roll method, a curtain coating method or the like can be mentioned. On the other hand, the method of laminating the resin sheet and the metal foil by heat laminating method is not particularly limited as long as it is a known method used industrially.

  When producing an entry sheet provided with metal foil on at least one side of the resin sheet, an adhesive layer may be formed between the metal foil and the resin sheet. That is, in the entry sheet provided with the metal foil on at least one side of the resin sheet, it is preferable to form an adhesive layer between the metal foil and the resin sheet because the adhesion between the metal foil and the resin sheet can be improved. In the present specification, a layer of a compound used to improve the adhesion between the metal foil and the resin sheet is defined as an adhesive layer. The resin that can be used for the adhesive layer is not particularly limited, and, for example, a thermoplastic resin or a thermosetting resin can be used. Moreover, you may use these together. Preferred thermoplastic resins include urethane resins, acrylic resins, vinyl acetate resins, vinyl chloride resins, polyester resins, and copolymers thereof. Further, preferable thermosetting resins include phenol resins, epoxy resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, polyurethanes, thermosetting polyimides, and cyanate resins. Among them, epoxy resins and unsaturated polyester resins are more preferable. The thickness of the adhesive layer is preferably 0.001 to 0.5 mm. This is because a sufficient adhesion effect can be obtained in this range to improve the adhesion between the metal foil and the resin sheet. Further, the method for forming the adhesive layer is not particularly limited as long as it is a known method used industrially. For example, a method of dissolving or dispersing the above-described resin in a solvent and forming an adhesive layer by a coating method using a bar coater, a gravure roll, a die or the like, a roll, a kneader, or other kneading of the above resin The method of heat-melting suitably mixing using a means, and the method of forming an adhesive layer by the roll method or the curtain coat method etc. is mentioned. In addition, as the metal foil used in the present embodiment, a commercially available product in which a metal foil is coated with an adhesive layer may be used.

  The thickness of each layer of the resin sheet, the metal foil, the adhesive layer, the adhesive layer and the like constituting the above-mentioned entry sheet can be measured as follows. First, the entry sheet is cut in the direction perpendicular to the entry sheet using a cross-section polisher (Cross-SECTION POLISHER SM-09010 manufactured by Nippon Denshi Datum Co., Ltd.) or an ultramicrotome (EM UC7 manufactured by Leica). Next, using a SEM (Scanning Electron Microscope, Scanning Electron Microscope, VE-7800 manufactured by KEYENCE), observe the cut surface in the direction perpendicular to the cut surface, and measure the thickness of each layer constituting the entry sheet. . In that case, thickness of five places is measured with respect to one visual field, and let the average value be thickness of each layer.

  Hereinafter, the present invention will be specifically described using examples and comparative examples. In addition, the following Example showed only an example of embodiment of this invention, and this invention is not limited to these.

  The material to be cut (the drilled material) used in Examples 1 to 3 and Comparative Examples 1 to 17 in Table 1, the resin component used in the manufacture of the entry sheet, solid lubricant, metal foil, for drilling The specifications of the drilling equipment used, the drill bit, and the equipment used for evaluation are shown.

<Example of preparation of entry sheet>
(Preparation of entry sheet A)
10 parts by mass of polyethylene glycol / dimethyl terephthalate polycondensate (Pogen PP-15, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 10 parts by mass of polyethylene oxide (Altop MG150, manufactured by Meisei Kogyo Co., Ltd.), polyoxyethylene monostearate ( Using a single-screw extruder, 30 parts by mass of Nonion S-40 (manufactured by Nippon Oil and Fats Co., Ltd.) and 50 parts by mass of graphite (X-100, Ito Graphite Industry Co., Ltd.) in an extruder at a temperature of 140 ° C. By molding, a resin sheet (resin sheet A) having a thickness of 1.0 mm was produced.
In addition, a 0.01 mm thick polyester-based resin layer (Vyronal MD-1200, manufactured by Toyobo Co., Ltd.) is formed as an adhesive layer on one side of a 0.15 mm thick aluminum foil (1N30-H18, manufactured by Mitsubishi Aluminum Corporation) An adhesive layer-formed aluminum foil was prepared.
One resin sheet A is disposed on the adhesive layer surface of the adhesive layer-forming aluminum foil, and the adhesive layer-forming aluminum foil is further disposed on the resin sheet A so that the adhesive layer and the resin sheet A are in contact with each other. Heat-laminate at 150 ° C. using OHL-2400 (A / N Co., Ltd.) to form an integrated sheet, forming an adhesive layer-forming aluminum foil / resin sheet A / an adhesive layer-forming aluminum foil Was produced.

<Examples 1 to 3>
The entry sheet A produced as described above was fixed to the cutting tool (cemented carbide drill) approach surface of the material to be machined using a jig. Cutting with a cemented carbide drill (drilling) was performed under the conditions shown in Table 2. Table 2 shows the evaluation results of the height of the burr around the cutting hole on the exit side of the drill bit and the surface temperature of the drill bit during cutting.

Comparative Examples 1 to 15
In Comparative Examples 1 to 13, the cutting was performed without arranging the entry sheet A on the cutting tool entry surface of the material to be cut. Moreover, in Comparative Examples 14 and 15, as in Examples 1 to 3, the entry sheet A is fixed to the cutting tool (carbide carbide drill) approach surface of the material to be machined using a jig, and Table 3 Cutting was performed under the conditions shown in FIG. As in Examples 1 to 3, the height of the burr around the cutting hole on the exit side of the drill bit and the surface temperature of the drill bit during cutting were evaluated. The evaluation results are shown in Table 3.

<Evaluation>
In Examples 1 to 3 and Comparative Examples 1 to 15, the height of the burr around the cutting hole on the drill bit outlet side and the surface temperature of the drill bit during cutting were evaluated as follows.
(1) The height of the burr around the cutting hole on the drill bit outlet side The drill bit exit face of the through hole after cutting was photographed using a V-LASER microscope (VK-9710, manufactured by Keyence Corporation) . The height of the burr around the cutting hole on the exit side of the drill bit was measured using analysis software (VK Analyzer version 1.2.0.2, manufactured by Keyence Corporation) for the photographed data. At this time, the heights of the burrs were measured at eight randomly selected locations, and the average value was obtained.
(2) Surface temperature of drill bit during cutting The tip of the drill bit penetrating the material to be cut is photographed using an infrared radiation thermometer (InfReC Themo GEAR G120EX, made by NEC Avio Infrared Technologies Co., Ltd.) and a thermal image The surface temperature of the drill bit during cutting was measured.

  Regarding the results of Examples 1 to 3 of Table 2 and Comparative Examples 1 to 15 of Table 3, the relationship between the height of the burr around the cutting hole on the drill bit outlet side and the rotational speed of the drill bit is summarized in FIG. It can be seen that the height of the burr is greatly reduced when the rotational speed of the drill bit is 720 rpm or less. Further, it is understood from Example 1 and Comparative Example 7 that the height of the burr can be suppressed to 217 μm to 73 μm by using the entry sheet. That is, it can be seen that the rotation speed of the drill bit is 720 rpm or less and the height of the burr can be remarkably suppressed by using the entry sheet.

  For the results of Examples 1 to 3 of Table 2 and Comparative Examples 1 to 15 of Table 3, the relationship between the surface temperature of the drill bit during cutting and the rotational speed of the drill bit is summarized in FIG. It can be seen that the surface temperature of the drill bit is lowered when the rotation speed of the drill bit is 720 rpm or less. Further, it is understood that the surface temperature of the drill bit can be suppressed to 198 ° C. to 144 ° C. by using the entry sheet. That is, it can be seen that the increase in the surface temperature of the drill bit can be significantly suppressed by using the rotation speed of the drill bit of 720 rpm or less and using the entry sheet.

  Regarding the results of Examples 1 to 3 of Table 2 and Comparative Examples 1 to 15 of Table 3, the relationship between the height of the burr around the cutting hole on the drill bit outlet side and the surface temperature of the drill bit during cutting is shown in FIG. Summarized. There is a correlation between the height of the burr around the cutting hole on the drill bit exit side and the surface temperature of the drill bit during cutting, and the lower the surface temperature of the drill bit during cutting, the smaller the height of the burr I understand the trend.

  From the above, in order to form high-quality cutting holes, it is necessary to lower the surface temperature of the drill bit at the time of cutting, and the rotation speed of the drill bit which is a cutting tool is 720 rpm or less. And it turns out that it is extremely important to use an entry sheet. It is presumed that this is due to the change in mechanical properties due to the heat peculiar to the metal to be cut. For example, a titanium alloy (Ti-6Al-4V) is an α-β alloy, which is considered to have a mechanical property changing at around 200 ° C.

  The method of cutting (for example, drilling) a difficult-to-grindable metal (for example, titanium alloy) of the present invention can lower the temperature of the drill bit at the time of cutting compared to the conventional processing method. And, it is possible to suppress the occurrence of burrs at the outlet part through which the drill bit passes. As a result, since the high-quality cutting hole can be provided compared with the conventional method, industrial applicability is very high.

Claims (13)

  A method for cutting a metal having a Vickers hardness of 100 or more using an entry sheet for cutting, wherein the entry sheet for cutting including at least a resin sheet is used as the entry sheet for cutting, and the metal is used for the metal The cutting entry sheet is placed on the surface where the drill bit, which is a cutting tool, enters, and the rotation speed of the drill bit is 100 rpm or more and 720 rpm or less, and the feed speed of the drill bit is 5 mm / min or more 50 mm / A metal cutting method in which cutting is performed by controlling the surface temperature of the drill bit at a cutting process to 200 ° C. or less, and setting it to min or less.   The metal cutting method according to claim 1, wherein the rotational speed of the drill bit is 100 rpm or more and 380 rpm or less.   The metal cutting method according to claim 1, wherein the metal is a titanium alloy.   The metal cutting method according to claim 3, wherein the material of the titanium alloy is Ti-6Al-4V.   The metal cutting method according to any one of claims 1 to 4, wherein the cutting is a process for forming a through hole.   The metal cutting method according to any one of claims 1 to 5, wherein a material of the drill bit is a cemented carbide.   The metal cutting method according to any one of claims 1 to 6, wherein the diameter of the drill bit is 2 mm or more and 7 mm or less.   The metal cutting method according to any one of claims 1 to 7, wherein the resin sheet contains a water-soluble resin.   The metal cutting method according to any one of claims 1 to 7, wherein the resin sheet contains a water-insoluble resin.   The metal cutting method according to any one of claims 1 to 9, wherein the resin sheet contains a solid lubricant.   The thickness of the said resin sheet is 0.1 mm or more and 20 mm or less, The metal cutting method in any one of Claims 1-10.   The metal cutting method according to any one of claims 1 to 11, wherein the cutting entry sheet further comprises a metal foil on at least one side of the resin sheet. The metal cutting method according to any one of claims 1 to 12, wherein the cutting entry sheet further has an adhesive layer on a surface in contact with the metal to be cut.

Images