Abstract: A main body (3) of a replaceable-tip cutting tool (1) includes a cylinder-shaped cylindrical portion (32) made from a first metal material and extending in an axial direction, and with a female thread portion (33) provided on an inner circumference (40) of the cylindrical portion (32) and capable of being screwed together with a male threaded portion (24) of a cutting head (2). The female thread portion (33) includes a first female thread portion (34) and a second female thread portion (35). The first female thread portion (34) is a portion between a top of a female thread crest (37) of the female thread portion (33) and a portion of the female thread portion (35) that is on the female thread crest (37) side of a female thread root (36) and on the female thread root side of a portion corresponding to an effective diameter of the female thread portion (33). The first female thread portion (34) is made from a second metal material that is different from the first metal material.

Abstract: A main body (3) of a replaceable-tip cutting tool (1) includes a cylinder-shaped cylindrical portion (32) made from a first metal material and extending in an axial direction, and with a female thread portion (33) provided on an inner circumference (40) of the cylindrical portion (32) and capable of being screwed together with a male threaded portion (24) of a cutting head (2). The female thread portion (33) includes a first female thread portion (34) and a second female thread portion (35). The first female thread portion (34) is a portion between a top of a female thread crest (37) of the female thread portion (33) and a portion of the female thread portion (35) that is on the female thread crest (37) side of a female thread root (36) and on the female thread root side of a portion corresponding to an effective diameter of the female thread portion (33). The first female thread portion (34) is made from a second metal material that is different from the first metal material.

Abstract: To provide a cutting tool in which the amount of waste of a main body unit and a cutting head can be suppressed and oscillation at the time of a cutting process can be suppressed. In a cutting tool 100, a helisert 20 made of steel that is lower in rigidity than cemented carbide is provided between an external screw unit 32 and an internal screw unit 11. Accordingly, the external screw unit 32 and the internal screw unit 11 are prevented from being brought into contact with each other, so that a thread 33 of the external screw unit 32 and a thread 12 of the internal screw unit 11 can be prevented from being damaged. Further, oscillation of a cutting head 30 against the main body unit 10 can be absorbed by providing the helisert 20 between the external screw unit 32 and the internal screw unit 11 because steel is lower in rigidity than cemented carbide.

Abstract: A neck portion grinding apparatus and method is designed to reduce working man-hours and to improve processing accuracy with respect to a processing of a workpiece. The neck portion grinding apparatus includes a grinding device having a disc-like grinding wheel and a wheel rotating device for rotating the grinding wheel, and a machine tool having a main shaft for rotatably supporting a rotating tool and a table mounting the grinding device thereon, and relatively moving the main shaft and the table by numeral control. A shape of a neck portion of the rotating tool can be changed by relatively moving the main shaft and the table while mutually rotating the rotating tool and the grinding wheel, and grinding the rotating tool by the grinding wheel.

Abstract: A neck portion grinding apparatus and method is designed to reduce working man-hours and to improve processing accuracy with respect to a processing of a workpiece. The neck portion grinding apparatus includes a grinding device having a disc-like grinding wheel and a wheel rotating device for rotating the grinding wheel, and a machine tool having a main shaft for rotatably supporting a rotating tool and a table mounting the grinding device thereon, and relatively moving the main shaft and the table by numeral control. A shape of a neck portion of the rotating tool can be changed by relatively moving the main shaft and the table while mutually rotating the rotating tool and the grinding wheel, and grinding the rotating tool by the grinding wheel.

Abstract: A cutting tool including a cutter head and a holder. One of the cutter head and the holder has a recess formed in its axial end portion and defined by its circumferential wall. The other of the cutter head and the holder has a protrusion formed in its axial end portion, such that the cutter head and the holder are detachably attached to each other, with the protrusion being introduced in the recess by an axial distance. The above-described one has coaxial holes formed in the circumferential wall. The above-described other has an engaging surface which is recessed from an outer circumferential surface of the protrusion and which is held in engagement with a pin that is received in the coaxial holes. Each of the coaxial holes has an axis which is inclined, with respect to a plane perpendicular to an axis of the above-described one, in a direction causing the above-described axial distance to be increased by a cutting resistance generated in a cutting operation.

Abstract: A non-rotary cutting tool which is to be moved relative to a workpiece in a predetermined direction for cutting the workpiece, with its rake face being held substantially perpendicular to the predetermined direction. The cutting tool includes (a) a generally cylindrical shank portion, and (b) a generally semi-cylindrical body portion which has an outer circumferential surface constituted by the rake face and a semi-cylindrical surface. The semi-cylindrical body portion has a cutting edge which is defined by an edge of the rake face and which is covered with a diamond coating. Also disclosed is a process of machining a scroll member of a scroll compressor by using this non-rotary cutting tool.

Abstract: A ball endmill includes a cylindrical tool body that is to be rotated about its axis, ball-nosed end cutting edges located in an axially distal end portion of the tool body and describing a semi-spherical-shaped locus during rotation of the tool body, and spiral gashes located in the axially distal end portion of the tool body and defining rake faces of the respective ball-nosed end cutting edges. The tool body is made, at least at its part providing each ball-nosed end cutting edge, of a hard sintered body. Each ball-nosed end cutting edge is inclined with respect to the axis by a helix angle in a range from about 10° to about 30°. The tool body has, in its distal end, a non-gashed central area in which the spiral gashes do not exist. A ratio of a size of the non-gashed central area to a ball nose radius is in a range from about 0.03 to about 0.1.

Abstract: A process of machining a scroll member of a scroll compressor by using a non-rotary cutting tool. The non-rotary cutting tool is moved relative to a workpiece in a predetermined direction for cutting the workpiece, with its rake face being held substantially perpendicular to the predetermined direction. The cutting tool includes (a) a generally cylindrical shank portion, and (b) a generally semi-cylindrical body portion which has an outer circumferential surface constituted by the rake face and a semi-cylindrical surface. The semi-cylindrical body portion has a cutting edge which is defined by an edge of the rake face and which is covered with a diamond coating. The rake face has a planar surface and a constant width throughout the cutting edge.

Abstract: A cutting tool including a cutter head and a holder. One of the cutter head and the holder has a recess formed in its axial end portion and defined by its circumferential wall. The other of the cutter head and the holder has a protrusion formed in its axial end portion, such that the cutter head and the holder are detachably attached to each other, with the protrusion being introduced in the recess by an axial distance. The above-described one has coaxial holes formed in the circumferential wall. The above-described other has an engaging surface which is recessed from an outer circumferential surface of the protrusion and which is held in engagement with a pin that is received in the coaxial holes. Each of the coaxial holes has an axis which is inclined, with respect to a plane perpendicular to an axis of the above-described one, in a direction causing the above-described axial distance to be increased by a cutting resistance generated in a cutting operation.

Abstract: A non-rotary cutting tool which is to be moved relative to a workpiece in a predetermined direction for cutting the workpiece, with its rake face being held substantially perpendicular to the predetermined direction. The cutting tool includes (a) a generally cylindrical shank portion, and (b) a generally semi-cylindrical body portion which has an outer circumferential surface constituted by the rake face and a semi-cylindrical surface. The semi-cylindrical body portion has a cutting edge which is defined by an edge of the rake face and which is covered with a diamond coating. Also disclosed is a process of machining a scroll member of a scroll compressor by using this non-rotary cutting tool.

Abstract: A process of machining a scroll member of a scroll compressor by using a non-rotary cutting tool. The non-rotary cutting tool is to be moved relative to a workpiece in a predetermined direction for cutting the workpiece, with its rake face being held substantially perpendicular to the predetermined direction. The cutting tool includes (a) a generally cylindrical shank portion, and (b) a generally semi-cylindrical body portion which has an outer circumferential surface constituted by the rake face and a semi-cylindrical surface. The semi-cylindrical body portion has a cutting edge which is defined by an edge of the rake face and which is covered with a diamond coating.

Abstract: A non-rotary cutting tool which is to be moved relative to a workpiece in a predetermined direction for cutting the workpiece, with its rake face being held substantially perpendicular to the predetermined direction. The cutting tool includes (a) a generally cylindrical shank portion, and (b) a generally semi-cylindrical body portion which has an outer circumferential surface constituted by the rake face and a semi-cylindrical surface. The semi-cylindrical body portion has a cutting edge which is defined by an edge of the rake face and which is covered with a diamond coating. Also disclosed is a process of machining a scroll member of a scroll compressor by using this non-rotary cutting tool.

Abstract: A method of operating a blast furnace comprising the steps of selecting sight factors mathematically and statistically as effective in determining the operating condition of a blast furnace, sensing the eight factors as sample data, converting the sample data into variable factors, comparing the sample data and the variable factors with predetermined limiting factors, generating numerical non-dimension values corresponding to the level of satisfaction between the sample date or variable factors and the corresponding limiting values, multiplying the numerical non-dimensional values by predetermined corresponding weight allocation indices, summing separately the results of the multiplication for the sample data and the variable factors to form a numerical factor grand addition output and a variable factors grand addition output, summing the numerical factors grand addition output and the variable factors grand addition output to form an overall grand addition output and taking appropriate action to control the