Abstract:
A drilling apparatus includes: a drill rotatable about a center axis and capable of advancing and retracting along the axis; and a pressing unit for pressing a work in an advancing direction of the drill. The drilling apparatus advances the drill while rotating the drill about the center axis to form a hole in the work, in a state in which the work is pressed by the pressing unit. A pressing force applied on the work by the pressing unit is set to a predetermined pressing force based on machining reaction applied to the drill from the work during drilling and the pressing force causing deformation of the work in the advancing direction of the drill. The predetermined pressing force can suppress deformation of the work and displacement of the drill due to the machining reaction. The machining reaction and the pressing force are calculated beforehand in a drilling test.
Abstract:
A drill includes a cutting edge. The cutting edge has a point angle which is continuously decreased from a center-position point angle A (herein, 0°
Abstract:
According to one implementation, a drill has at least one cutting edge. A projected shape of a passing area of a ridgeline of the at least one cutting edge when the at least one cutting edge is rotated around a tool axis becomes a line-symmetric and discontinuous line along a parabola, two parabolas, an ellipse or two ellipses. The projected shape is drawn on a projection plane parallel to the tool axis.
Abstract:
A tool feeding mechanism for a tool driving device includes a cylinder mechanism, a positioning mechanism, and a holding mechanism. The cylinder mechanism moves a tool rotation driving device to hold and rotate a tool, in a tool axis direction on an exterior of a cylinder tube using power of a piston. The positioning mechanism is connected to the cylinder tube side of the cylinder mechanism either directly or indirectly in order to position the cylinder mechanism relative to a workpiece. The holding mechanism holds the tool rotation driving device such that the power of the piston in the cylinder mechanism is transmitted to the tool rotation driving device.