A combination tool including a tool holder that extends along a tool rotational axis that defines an axial extension, an inner cutting tool for machining a first, central hole region and an outer, sleeve-shaped cutting tool for machining a second hole region radially outwards relative to the first hole region.

A cutting tool assembly includes a first tool part and a second tool part. The first tool part has a forward end portion including a cutting edge and a rearward end portion having a conical section and an engagement section. The second tool part includes a conical recess and a clamping device rearwards the conical recess. The clamping device is provided in a transversal cavity of the second tool part and has a first clamp block, a second clamp block and a differential screw engaging the first and second clamp blocks. The first and second clamp blocks engage the engagement section of the first tool part to pull the first tool part into the conical recess when the first and second clamp blocks are moved towards each other by the differential screw protruding rearwards from the first and second clamp blocks.

A cutting tool includes a body, a blade, and a position adjustment screw. The body surrounds an axial line. The blade includes a cutting edge portion and a shank portion. The position adjustment screw is in contact with the shank portion. The position adjustment screw includes a head portion in contact with the shank portion and a joint portion continuous to the head portion and joined to the body. The head portion includes a tip end surface in contact with the shank portion, a connection surface continuous to the joint portion, and an outer circumferential surface continuous to each of the tip end surface and the connection surface. When viewed in a direction perpendicular to the axial line, a part of the outer circumferential surface is exposed through the second hole and a remainder of the outer circumferential surface is covered with the body.

Milling tools and methods are disclosed. The method may include moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. Contact between the milling tool and a wall of the bore may be initiated in a region of the wall having a least amount of material at the axial position. The milling tool may include a tool shaft having a longitudinal axis, a first set of radially spaced cutting inserts coupled to the tool shaft, and a directly adjacent second set of radially spaced cutting inserts coupled to the tool shaft and spaced from the first set of cutting inserts along the longitudinal axis. The first and second sets of cutting inserts may be staggered from each other by at least 10 degrees.

Milling tools and methods are disclosed. The method may include moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. Contact between the milling tool and a wall of the bore may be initiated in a region of the wall having a least amount of material at the axial position. The milling tool may include a tool shaft having a longitudinal axis, a first set of radially spaced cutting inserts coupled to the tool shaft, and a directly adjacent second set of radially spaced cutting inserts coupled to the tool shaft and spaced from the first set of cutting inserts along the longitudinal axis. The first and second sets of cutting inserts may be staggered from each other by at least 10 degrees.

A machining tool forms a first relief surface, a valve seat surface, and a second relief surface by cutting the inner periphery of a valve seat blank having an opening. The machining tool is provided with: a tool body rotationally driven about an axis; a plurality of cutting tools rotating with the tool body; a cartridge mounted to the tool body so as to be capable of moving forward and backward along the axis; and a cam in contact with the base end surface of the cartridge and moving the cartridge forward and backward. At least one of the plurality of cutting tools is mounted to the cartridge.

A mobile device for machining a workpiece, the mobile device including a shaft rotatable about a rotation axis; a carriage rotatable with the shaft about the rotation axis and axially, or radially displaceable relative to the rotation axis; a tool support for a cutting tool, the tool support connected to the carriage and displaceable along a carriage axis and in a direction perpendicular to the carriage axis; and a transmission that couples the shaft to the tool support and the carriage so that the tool support is displaceable along a path that includes an axial and a radial movement component relative to the shaft.

A machining tool forms a first relief surface, a valve seat surface, and a second relief surface by cutting the inner periphery of a valve seat blank having an opening. The machining tool is provided with: a tool body rotationally driven about an axis; a plurality of cutting tools rotating with the tool body; a cartridge mounted to the tool body so as to be capable of moving forward and backward along the axis; and a cam in contact with the base end surface of the cartridge and moving the cartridge forward and backward. At least one of the plurality of cutting tools is mounted to the cartridge.

A combination tool including a tool holder that extends along a tool rotational axis that defines an axial extension, an inner cutting tool for machining a first, central hole region and an outer, sleeve-shaped cutting tool for machining a second hole region radially outwards relative to the first hole region.

A method for manufacturing a cylinder head includes: preparing a cylinder head casting having an intake passage, an exhaust passage, and a combustion chamber by casting using a mold and a plurality of cores; machining an intake port, an intake valve seat, an intake valve guide bore, an exhaust port, an exhaust valve seat, and an exhaust valve guide bore in the cylinder head casting by a first cylindrical tool; and forming a tapered surface on a portion of edge of the intake port by a second cylindrical tool. In particular, the second cylindrical tool moves along a predetermined trajectory at the edge portion of the intake port and rotates around an axis simultaneously to machine the tapered surface.