JP5869864B2 - Machining tool and machining method - Google Patents

Description

Embodiments described herein relate generally to a machining tool and a machining method.

  Conventionally, various tools have been proposed for processing hard and brittle materials such as ceramic sintered bodies and cemented carbides. For example, a processing tool has been proposed in which diamond or cubic boron nitride (CBN) abrasive grains are bonded to the surface of columnar tool steel (see, for example, Patent Document 1 and Patent Document 2).

  Further, a polishing rotary tool in which inorganic long fibers are arranged in a resin matrix and hardened by containing abrasive grains such as diamond has been proposed (for example, see Patent Document 3).

  Furthermore, as a tool for drilling brittle materials such as plate glass and ceramics, a diamond core drill for drilling in which a grindstone portion composed of cylindrical diamond abrasive grains is provided at the tip of a steel shank has been proposed ( For example, see Patent Document 4).

JP 2008-296321 A JP 2002-66927 A JP 2000-280179 A JP-A-11-156618

It is an object of the present invention to provide a machining tool and a machining method capable of processing a hard-working material such as cemented carbide, ceramics, cermet, and a mixture thereof, which is difficult to process. .

The machining tool which concerns on embodiment of this invention has a process part and a shank part. The processing part is formed by solidifying hard abrasive grains in a columnar shape. The shank portion is connected to the processing portion. The machining tool is configured to contact the workpiece while rotating the machining portion together with the shank portion, and to process the workpiece while rubbing the hard abrasive grains. Further, the processing portion is a metal reinforcing member that reinforces the hard abrasive grains and wears out together with the hard abrasive grains when the workpiece is processed, and a cylindrical metal that covers the hard abrasive grains, and The reinforcing member constituted by at least one of the plate-like metals provided in the hard abrasive grains with the longitudinal direction directed in the axial direction of the processed portion is provided, and a plurality of reinforcing members are provided in the thickness direction of the metal constituting the reinforcing member. Holes were provided.
Moreover, the machining method which concerns on embodiment of this invention processes a workpiece by using the said machining tool .

According to the machining tool and the machining method according to the embodiment of the present invention, materials that are difficult to process, such as cemented carbide, ceramics, cermet, and a mixture obtained by mixing them, can be further satisfactorily processed.

The longitudinal cross-sectional view of the machining tool which concerns on embodiment of this invention. The left view of the machining tool shown in FIG. The figure explaining the role of the reinforcement member shown in FIG. The figure which shows the example which provided the some hole in the thickness direction of the metal which comprises the reinforcement member shown in FIG. The figure which shows the structural example of the reinforcement member shown in FIG. The figure which shows the example which comprised the front-end | tip of the process part shown in FIG. 1 as a cone shape, and comprised the machining tool as a drilling tool.

A machining tool and a machining method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

(Configuration and function)
FIG. 1 is a longitudinal sectional view showing a configuration of a machining tool according to an embodiment of the present invention. FIG. 2 is a left side view of the machining tool 1 shown in FIG.

The machining tool 1 has a machining part 2 and a shank part 3. The processed part 2 is configured by hardening the hard abrasive grains 4 into a hollow column. FIG.1 and FIG.2 shows the example which comprised the process part 2 in the shape of a solid cylinder. Hard abrasive grains 4 include diamond abrasive grains, CBN abrasive grains, alumina-based A abrasive grains mainly composed of aluminum oxide (Al ₂ O ₃ ), C abrasive grains mainly composed of silicon carbide SiC, and tungsten carbide abrasive grains. Examples thereof include abrasive grains of inorganic material having high hardness, such as grains and garnet (also called garnet or red meteorite) abrasive grains.

  As a method of hardening the hard abrasive grains 4, a method of hardening the hard abrasive grains 4 by mixing and heating the hard abrasive grains 4 in a binder material containing a thermosetting resin, or adding abrasive grains to a molten metal such as nickel. Thus, there is a method of electrodepositing the hard abrasive grains 4 on the molten metal by passing an electric current. Examples of the thermosetting resin include resins such as epoxy resins and glass resins. However, the hard abrasive grains 4 may be hardened by other known methods.

  Further, the shank portion 3 is connected to the processing portion 2. That is, the machining tool 1 can be manufactured by connecting a shank to the hardened hard abrasive grains 4. As the material of the shank portion 3, any material can be used as long as it can be held by the tool holder. Typically, the shank part 3 is comprised with metals, such as steel. Further, the shape of the shank portion 3 is usually a columnar shape as shown in FIG.

  Furthermore, the processing part 2 can be provided with a metal reinforcing member 5 for reinforcing the hard abrasive grains 4. FIG. 1 shows an example in which a cylindrical metal having both ends opened to cover the hard abrasive grains 4 is provided as a reinforcing member 5 in the processed portion 2. As the material of the reinforcing member 5, a metal such as steel can be used.

  The machining tool 1 is configured to contact the product to be processed while rotating the processing unit 2 together with the shank unit 3 and process the product to be processed while reducing the hard abrasive grains 4.

(Function)
Next, the operation of the machining tool 1 will be described.

  The machining tool 1 shown in FIGS. 1 and 2 can be used in a machine tool such as a drilling machine, a boring machine, a milling machine, or a mining center. That is, the machining tool 1 can be attached to a holder of a machine tool.

  Specifically, it is possible to contact the workpiece to be processed while rotating the hard abrasive grains 4 of the processing section 2 and scrape and remove the workpiece to be processed while rubbing the hard abrasive grains 4. In particular, even materials that are difficult to process, such as cemented carbide, ceramics, cermet, and mixtures thereof, can be processed satisfactorily. In addition, carbon fiber reinforced carbon composites (C / C composite: Carbon / Carbon Composites), ceramic matrix composites (CMC: Ceramic Matrix Composite), and new carbon / metal composite materials (C / CMC: Carbon Carbon) Even difficult-to-cut materials such as Metal Composite can be processed.

  By the way, the polishing can be understood as a process of improving the surface roughness by polishing the surface to be processed using free abrasive grains. On the other hand, grinding can be understood as processing for obtaining a shape with a predetermined dimension by physically dropping the surface to be processed using fixed abrasive grains constituting a multi-blade and changing the shape. Moreover, cutting can be understood as a process of cutting a material with a single blade.

  Therefore, the machining tool 1 can be classified as a grinding tool from the viewpoint of scraping off a workpiece to be processed using abrasive grains. However, the machining tool 1 is different from the conventional grinding tool in that the hard abrasive grain 4 is released and the workpiece is scraped off. Further, the conventional grinding process is a process whose main purpose is finishing of the target surface. On the other hand, according to the machining tool 1, various processes such as drilling, deburring, chamfering, roughing of milling, and finishing of milling can be performed by adjusting the rotation speed and feed.

  Therefore, the machining by the machining tool 1 can be considered as a machining by a novel machining method. For this reason, the machining with the machining tool 1 is simply referred to as machining or machining here. The same applies hereinafter.

  FIG. 3 is a diagram for explaining the role of the reinforcing member 5 shown in FIG. 1.

  As described above, by rotating the machining tool 1 in the rotation direction D, it is possible to perform processing such as drilling or milling on the workpiece 10. Therefore, the machining tool 1 is loaded in the thrust direction T during rotation. For this reason, stresses and forces such as compression, twisting and bending act on the processed portion 2. Therefore, breakage and collapse of the hard abrasive grains 4 can be prevented by the reinforcing member 5 made of a metal having good toughness.

  The reinforcing member 5 shown in FIG. 1 is a cylindrical metal that covers the outer surface of the hard abrasive grains 4. Therefore, as shown in FIG. 3, the reinforcing member 5 can suppress the deformation or collapse of the hard abrasive grains 4 in the direction perpendicular to the tool axis.

  The reinforcing member 5 having a hardness smaller than that of the hard abrasive grains 4 is worn together with the hard abrasive grains 4 by contact with the workpiece 10 when the workpiece 10 is processed. However, the main body that scrapes off the workpiece 10 is the hard abrasive 4 of the processed portion 2. Therefore, it is desirable that the reinforcing member 5 be easily worn away by friction with the workpiece 10 and the hard abrasive grains 4 while suppressing breakage and collapse of the hard abrasive grains 4.

  Therefore, it is preferable that the thickness of the metal used as the reinforcing member 5 is about 0.1 mm to 1 mm so that the reinforcing member 5 is easily worn away by friction with the workpiece 10. That is, wear of the reinforcing member 5 can be promoted by reducing the contact area between the workpiece 10 and the reinforcing member 5.

  The machining tool 1 as described above changes the conventional idea of reducing the wear of the tool, and uses the hard abrasive grains 4 as a multi-blade, while reducing the hard abrasive grains 4 that are the main subject of machining, and the workpiece 10 to be processed. It is designed to be machined.

(effect)
For this reason, according to the machining tool 1, it is possible to satisfactorily machine materials that are difficult to machine, such as cemented carbide and ceramics. For example, the machining tool 1 can be used as a tool such as a drilling tool for an extremely difficult-to-cut material, an end mill, a deburring tool, and a chamfering tool.

(Modification)
(First modification)
FIG. 4 is a view showing an example in which a plurality of holes are provided in the thickness direction of the metal constituting the reinforcing member 5 shown in FIG.

  FIG. 4 shows a developed view of the reinforcing member 5 made of a cylindrical metal. As shown in FIG. 4, the reinforcing member 5 can be provided with a large number of holes 20 in the thickness direction. FIG. 4 shows an example in which a large number of holes 20 are arranged two-dimensionally. In particular, in the example shown in FIG. 4, the holes 20 are regularly arranged. That is, a row of holes 20 that are equally spaced in the thrust direction T is formed in a straight line. Further, the center position of each hole 20 is shifted in the thrust direction T from the center position of the hole 20 adjacent to the rotation direction D of the machining tool 1.

  As a result, the tip of the reinforcing member 5 has an uneven shape as shown in the lower part of FIG. Therefore, the reinforcing member 5 is in intermittent contact with the workpiece 10. That is, the area of the portion of the metal constituting the reinforcing member 5 that contacts the workpiece 10 is reduced. Thereby, the intensity | strength in the circumferential direction of the reinforcement member 5 is reduced. Therefore, when the machining tool 1 is rotated in the rotation direction D, the reinforcing member 5 can be actively worn.

  On the other hand, the metal constituting the reinforcing member 5 forms a curved surface closed in a cylindrical shape. That is, the reinforcing member 5 does not have an end portion except for a portion that is in contact with the workpiece 10 and a portion that is connected to the shank portion 3. Therefore, the strength of the reinforcing member 5 in the diameter direction is maintained. As a result, it is possible to easily reduce the portion of the reinforcing member 5 that contacts the workpiece 10 while maintaining the toughness of the processed portion 2 in the tool radial direction by the reinforcing member 5.

  In particular, as shown in FIG. 4, by regularly providing the holes 20 in the reinforcing member 5, the reinforcing member 5 can be uniformly rubbed down. Further, the reinforcing member 5 can be worn more effectively by increasing the number of holes 20.

  In addition to the example shown in FIG. 4, punching in an arbitrary shape such as a triangular shape or a rectangular shape may be provided in the reinforcing member 5 as the plurality of holes 20.

(Second modification)
FIG. 5 is a view showing a structural example of the reinforcing member 5 shown in FIG.

  The reinforcing member 5 is not limited to the structure illustrated in FIG. 1 and can have various structures. FIG. 5 shows variations in the cross-sectional shape of the reinforcing member 5 as viewed from the thrust direction T.

  For example, as shown in (A), in addition to the reinforcing member 5 that protects the outer surface of the columnar hard abrasive grains 4, a cylindrical reinforcing member 5 can also be provided inside the hard abrasive grains 4. If the reinforcing member 5 shown in (A) is provided, the reinforcing effect of the hard abrasive grains 4 can be improved. For this reason, as shown in FIG. 4, even if the strength per unit area of the reinforcing member 5 is reduced by providing the holes 20 in the reinforcing member 5, the reinforcing effect of the hard abrasive grains 4 can be maintained well.

  Further, the reinforcing member 5 is easily worn as the angle formed by the thickness direction and the rotation direction D approaches 0 degrees. Therefore, as shown in (B), a plate-like metal whose width direction is the diameter direction of the processed portion 2 can be provided in the processed portion 2 as the reinforcing member 5 inside the hard abrasive grain 4. (B) shows an example in which a plurality of flat metal plates are arranged radially. If the reinforcing member 5 shown in (B) is provided, the reinforcing effect of the hard abrasive grains 4 can be improved while improving the wear effect.

  Similarly, as shown in (C), a metal having a lattice-like cross section can be provided in the processed portion 2 as the reinforcing member 5 inside the hard abrasive grain 4. In addition, a honeycomb-shaped metal may be provided in the processed portion 2 as the reinforcing member 5.

  On the other hand, as shown in (D), (E) and (F), the reinforcing member 5 can be provided only inside the hard abrasive grain 4 without providing the reinforcing member 5 on the outer surface of the hard abrasive grain 4. . If the reinforcing member 5 is provided only inside the hard abrasive 4 as shown in (D), (E) and (F), the side surface of the hard abrasive 4 can be improved while improving the strength and toughness of the processed portion 2. The used workpiece 10 can be machined. The same effect can be obtained by fixing the hard abrasive grains 4 to the outer surface of the reinforcing member 5 that covers the outer surface of the hard abrasive grains 4 as shown in FIG.

  In addition to the above examples, as shown in (G), (H) and (I), the reinforcing member has a cross section of a single or a plurality of polygons, lines, circles, etc., or a combination thereof. The structure of 5 can be appropriately determined according to the application of the machining tool 1.

  As described above, the reinforcing member 5 is configured by at least one of a cylindrical metal that covers the hard abrasive grain 4 and a plate-like metal provided inside the hard abrasive grain 4 with the longitudinal direction directed in the axial direction of the processed portion 2. be able to. Further, by providing the reinforcing members 5 inside and outside the hard abrasive grains 4 with holes 20 as shown in FIG. 4 in the thickness direction, the wear of the reinforcing members 5 can be promoted.

(Third Modification)
Moreover, it can be set as the suitable shape according to the use of the machining tool 1, without making the shape of the process part 2 into perfect pillar shape. For example, the shape of the part of the processing part 2 brought into contact with the workpiece 10 can be made an appropriate shape according to the application of the machining tool 1 without making it a plane.

  FIG. 6 is a view showing an example in which the tip of the processing unit 2 shown in FIG. 1 is formed into a cone shape and the machining tool 1 is configured as a drilling tool.

  As shown in FIG. 6A, the shape at the tip of the processed portion 2 can be conical. Thereby, the centering function can be provided in the processing part 2. Therefore, when the machining tool 1 is used as a drilling tool, it is possible to reduce the runout of the processing unit 2. And a hole can be processed with a favorable precision.

  On the other hand, as shown in FIG. 6 (B), the shape at the tip of the processed portion 2 may be a conical shape. Even in this case, since the tip of the processing unit 2 does not come into surface contact with the workpiece 10, the deflection of the processing unit 2 can be reduced. In addition, even if the hard abrasive 4 is worn away, a hole having a predetermined diameter is obtained. Therefore, drilling with an emphasis on dimensional accuracy is possible.

  In addition, the shape of the entire processing unit 2 is not limited to the tip of the processing unit 2, and an appropriate shape according to the application of the machining tool 1 can be used. For example, when the machining tool 1 is used as a drilling tool, the machining portion 2 can be provided with a back taper. Thereby, it can avoid that the side surface of the process part 2 contacts the workpiece 10 in a wide range.

  In particular, since the hard abrasive grains 4 are gradually worn away, it is desirable to provide a back taper in consideration of the change in the diameter of the processed portion 2. Therefore, it is preferable to provide a back taper in the processing portion 2 having a larger inclination angle than a back taper provided in a normal drilling tool.

  In addition, the shape of the processed portion 2 can be changed to various shapes as a tool for deburring, chamfering, or reverse chamfering.

  Furthermore, an oil hole (oil hole) for supplying cutting oil to the columnar hard abrasive grains 4 may be provided. Thereby, by supplying cutting oil, while exhaust heat is accelerated | stimulated, the fallen hard abrasive 4 and the workpiece 10 can be smoothly excluded from a process part. Note that the diameter of the oil hole for supplying the cutting oil is sufficiently smaller than the diameter of the processed portion 2. Therefore, the influence on the workability due to the presence of the oil holes can be ignored, and the hard abrasive grains 4 provided with the oil holes can be regarded as columnar shapes that are not substantially hollow. In other words, the portion of the hard abrasive grains 4 that contributes to the processing can be regarded as a columnar shape that is not hollow.

  However, the processed part 2 can also be configured by hardening the hard abrasive grains 4 into a hollow column shape according to the processing purpose such as deburring or expanding the diameter of the hole.

(Other embodiments)
Although specific embodiments have been described above, the described embodiments are merely examples, and do not limit the scope of the invention. The novel methods and apparatus described herein can be implemented in a variety of other ways. Various omissions, substitutions, and changes can be made in the method and apparatus described herein without departing from the spirit of the invention. The appended claims and their equivalents include such various forms and modifications as are encompassed by the scope and spirit of the invention.

DESCRIPTION OF SYMBOLS 1 Machining tool 2 Processing part 3 Shank part 4 Hard abrasive grain 5 Reinforcement member 10 Processed object 20 Hole T Thrust direction D Rotation direction

Claims (3)

A processing portion formed by solidifying hard abrasive grains in a columnar shape and a shank portion connected to the processing portion;
A machining tool configured to contact the object to be processed while rotating the processing part together with the shank part, and to process the object to be processed while reducing the hard abrasive grains ,
A metal reinforcing member that reinforces the hard abrasive grains in the processed portion and wears away with the hard abrasive grains when the workpiece is processed, and a cylindrical metal that covers the hard abrasive grains and a longitudinal direction Providing the reinforcing member composed of at least one of the plate-like metals provided inside the hard abrasive grains in the axial direction of the processed portion,
A machining tool provided with a plurality of holes in a thickness direction of a metal constituting the reinforcing member . The tip of the working portion and conical shape, the machining tool according to claim 1, wherein configured as drilling tool. A machining method for machining an object to be machined using the machining tool according to claim 1.

Images