Provided is a hole drilling machine and the method for drilling an oval hole and an inner-diameter-changing hole by means of the hole drilling machine, the machine and the method being configured so that the oval hole can be shaped with high accuracy and drilling of a complicated hole such as the inner-diameter-changing hole can be performed with high accuracy. A hole drilling machine 100 includes a spindle 101 and an auxiliary spindle 120 holding both end portions of a processing tool 102 having a cutting blade 103. The spindle 101 includes a spindle drive motor 106 configured to rotatably displace the processing tool 102 on a circular path, and a tool turnable-drive motor 105 configured to spin the processing tool 102. The auxiliary spindle 120 includes an auxiliary spindle drive motor 120b. In the auxiliary spindle drive motor 120b, a tool fitting portion 120a in which a tip end portion of the processing tool 102 is slidably fitted is synchronously rotatably driven on the same circular path as that for the spindle 101. A table reciprocatably-displacing mechanism 111 is provided between the spindle 101 and the auxiliary spindle 120. The table reciprocatably-displacing mechanism 111 reciprocatably displaces a work piece WK in an X-axis direction perpendicular to an axial direction of the spindle 101.

Provided is a hole drilling machine and the method for drilling an oval hole and an inner-diameter-changing hole by means of the hole drilling machine, the machine and the method being configured so that the oval hole can be shaped with high accuracy and drilling of a complicated hole such as the inner-diameter-changing hole can be performed with high accuracy. A hole drilling machine 100 includes a spindle 101 and an auxiliary spindle 120 holding both end portions of a processing tool 102 having a cutting blade 103. The spindle 101 includes a spindle drive motor 106 configured to rotatably displace the processing tool 102 on a circular path, and a tool turnable-drive motor 105 configured to spin the processing tool 102. The auxiliary spindle 120 includes an auxiliary spindle drive motor 120b. In the auxiliary spindle drive motor 120b, a tool fitting portion 120a in which a tip end portion of the processing tool 102 is slidably fitted is synchronously rotatably driven on the same circular path as that for the spindle 101. A table reciprocatably-displacing mechanism 111 is provided between the spindle 101 and the auxiliary spindle 120. The table reciprocatably-displacing mechanism 111 reciprocatably displaces a work piece WK in an X-axis direction perpendicular to an axial direction of the spindle 101.

Provided are a machining method and a machining device that can reduce the displacement from a target round shape due to elastic deformation after machining, and can shorten the time required to machine a target round shape in the work. A machining method machines a round hole in a work, and includes: a hole-shape acquisition step of acquiring a shape of a hole of the work; an inverted-shape acquisition step of inverting the shape of the hole acquired at the hole-shape acquisition step relative to a target round shape to acquire an inverted shape; and an inverted-shape machining step of machining the hole in accordance with the inverted shape acquired at the inverted-shape acquisition step.

Provided is a machining apparatus capable of improving the positioning accuracy of a machining tool as compared to conventional machines. A machining apparatus 1 includes a rotating tool, a machining tool provided on an outer periphery of the rotating tool, and a spindle head adapted to rotatably support the rotating tool. The machining apparatus includes a driving portion configured to move the spindle head in a direction perpendicular to an axis of rotation R of the rotating tool, a position sensor configured to measure a position of the spindle head on a plane perpendicular to the axis of rotation R, and a control unit configured to control the driving portion so as to move the machining tool in a direction perpendicular to the axis of rotation R of the rotating tool on the basis of the position of the spindle head.

Provided is a machining apparatus capable of improving the positioning accuracy of a machining tool as compared to conventional machines. A machining apparatus 1 includes a rotating tool, a machining tool provided on an outer periphery of the rotating tool, and a spindle head adapted to rotatably support the rotating tool. The machining apparatus includes a driving portion configured to move the spindle head in a direction perpendicular to an axis of rotation R of the rotating tool, a position sensor configured to measure a position of the spindle head on a plane perpendicular to the axis of rotation R, and a control unit configured to control the driving portion so as to move the machining tool in a direction perpendicular to the axis of rotation R of the rotating tool on the basis of the position of the spindle head.

A drilling and milling tool (100) for a metallic workpiece, with a drilling and milling shank (120) having a plurality of circumferentially-cutting cutter tips (151, 152, 153, 154) and a plurality of front-end-cutting cutter tips (131, 132). At least one of the front-end-cutting cutter tips (132) is, at the same time, a circumferentially-cutting cutter tip whose radially outermost cutting point or cutting edge section projects, in the radial direction (R), beyond the circumferentially-cutting cutter tips (151 152, 153, 154). The circumferentially-cutting cutter tips (151, 152, 153, 154) are made with straight cutting edges and together these cutting edges produce a cylindrical cut contour. Two methods that can be carried out with the drilling and milling tool (100) for producing a through-going bore in a metallic workpiece.

A drilling and milling tool (100) for a metallic workpiece, with a drilling and milling shank (120) having a plurality of circumferentially-cutting cutter tips (151, 152, 153, 154) and a plurality of front-end-cutting cutter tips (131, 132). At least one of the front-end-cutting cutter tips (132) is, at the same time, a circumferentially-cutting cutter tip whose radially outermost cutting point or cutting edge section projects, in the radial direction (R), beyond the circumferentially-cutting cutter tips (151 152, 153, 154). The circumferentially-cutting cutter tips (151, 152, 153, 154) are made with straight cutting edges and together these cutting edges produce a cylindrical cut contour. Two methods that can be carried out with the drilling and milling tool (100) for producing a through-going bore in a metallic workpiece.

A tool that cuts a hole for a single or double electric gang switch box. By having four blades, all cutting at the same time and in the shape of the switch box, a more accurate and appropriately placed hole may be provided. The hole saw may be configured with two centering drills so the tool is guided into the cut. An eccentric drive mechanism converts a rotary drive into reciprocating movement of perpendicularly opposed pairs of blades to cut a rectangular opening.

A tool spindle for a drilling tool may include a drive shaft for driving the drilling tool, a chuck connected rigidly to the drive shaft along a rotation axis directed longitudinally with respect to the drive shaft for receiving a clamping shank of the drilling tool, and at least one radial bearing radially enclosing at least a portion of the drive shaft for radially mounting the drive shaft, configured such that the radial bearing may mount the drive shaft to be rotatable about the rotation axis. The radial bearing may be an active magnetic bearing and may be configured such that it mounts the drive shaft to be pivotable about at least one pivot axis extending perpendicularly to the rotation axis through a fixed point, wherein the fixed point may be located in a centering countersink of the drilling tool when the drilling tool is clamped in the tool spindle.

A tool spindle for a drilling tool may include a drive shaft for driving the drilling tool, a chuck connected rigidly to the drive shaft along a rotation axis directed longitudinally with respect to the drive shaft for receiving a clamping shank of the drilling tool, and at least one radial bearing radially enclosing at least a portion of the drive shaft for radially mounting the drive shaft, configured such that the radial bearing may mount the drive shaft to be rotatable about the rotation axis. The radial bearing may be an active magnetic bearing and may be configured such that it mounts the drive shaft to be pivotable about at least one pivot axis extending perpendicularly to the rotation axis through a fixed point, wherein the fixed point may be located in a centering countersink of the drilling tool when the drilling tool is clamped in the tool spindle.