Method for chamfering

Claim 1

A method of chamfering an edge of a plate-like workpiece, especially a workpiece made of a silicon steel plate, comprising the steps of: providing a rotating circular cutter having a ring-shaped cutting edge portion formed along a periphery of a holder therefor, the cutting edge portion having an edge tip defining a circle, said edge tip having a rake angle within the range of 0 to -1.0 degrees and a relief angle whch has a zero or positive value; orienting the cutter to the workpiece so that the edge of the workpiece to be chamfered engages the edge tip at only one portion of the circle as the workpiece moves with respect to the cutter to engage various portions of the edge to be chamfered, this step of orienting including establishing positional relationships such that: (a) the angle formed between an upper surface of the workpiece and a working plane of the cutter, which plane includes a circle defined by the edge top of the cutting edge portion of the cutter, falls within the range of 0° to 45°, (b) the plane including the upper surface of the workpiece crosses at two points with said circle defined by the edge top of the cutting edge portion of the cutter, (c) the working plane of the cutter is inclined relative to the edge of the workpiece to be chamfered such that the working plane crosses with the edge of the workpiece at only the front portion of the cutter working plane in a moving direction of the workpiece so as to allow the edge of the workpiece to be chamfered only at the single cross point thereby formed, and (d) rotation of the circular cutter is permitted such that, for a projection of the cutter onto the upper surface of the workpiece, the edge tip of the cutting edge portion of the cutter is moved at the cross point from an overlapping region between the projection of the cutting and the workpiece to a non-overlapping region thereof; rotating the cutter; and moving the workpiece in a direction of a sense opposite to that of movement of the cutting edge portion of the cutter at the cross point so that successive portions of the edge to be chamfered engage the cross point thereby chamfering the edge at the cross point.

Claim 2

A method of chamfering an edge of a plate-like workpiece, especially a workpiece made of a silicon steel plate, comprising the steps of: providing a rotating circular cutter having a ring-shaped cutting edge portion formed along a periphery of a holder therefor, the cutting edge portion having an edge tip defining a circle, said edge tip having a rake angle within the range of 0 to -1.0 degrees and a relief angle whch has a zero or positive value; orienting the cutter to the workpiece so that the edge of the workpiece to be chamfered engages the edge tip at only one portion of the circle as the workpiece moves with respect to the cutter to engage various portions of the edge to be chamfered, this step of orienting including establishing positional relationships such that: (a) the angle formed between an upper surface of the workpiece and a working plane of the cutter, which plane includes a circle defined by the edge top of the cutting edge portion of the cutter, falls within the range of 0° to 45°, (b) the plane including the upper surface of the workpiece crosses at two points with said circle defined by the edge top of the cutting edge portion of the cutter, (c) the working plane of the cutter is inclined relative to the edge of the workpiece to be chamfered such that the working plane crosses with the edge of the workpiece at only the front portion of the cutter working plane in a moving direction of the workpiece so as to allow the edge of the workpiece to be chamfered only at the single cross point thereby formed, and (d) rotation of the circular cutter is permitted such that, for a projection of the cutter onto the upper surface of the workpiece, the edge tip of the cutting edge portion of the cutter is moved at the cross point from an overlapping region between the projection of the cutting and the workpiece to a non-overlapping region thereof; rotating the cutter; and moving the workpiece in a direction of a sense opposite to that of movement of the cutting edge portion of the cutter at the cross point so that successive portions of the edge to be chamfered engage the cross point thereby chamfering the edge at the cross point.

Claim 3

A method of chamfering an edge of a plate-like workpiece, especially a workpiece made of a silicon steel plate, comprising the steps of: providing a rotating circular cutter having a ring-shaped cutting edge portion formed along a periphery of a holder thereof, the cutting edge portion having an edge tip defining a circle, said edge tip having a rake angle within the range of 0 to -1.0 degrees and a relief angle which has a zero or positive angle; orienting the cutter to the workpiece so that the edge of the workpiece to be chamfered engages the edge tip at only one portion of the circle as the workpiece moves with respect to the cutter to engage various portions of the edge to be chamfered, this step of orienting including establishing positional relationships such that: (a) the angel formed between a lower surface of the workpiece and the working plane of the cutter, which plane includes a circle defined by the edge tip of the cutting edge portion of the cutter, falls within the range of 0° to 45°, (b) the plane including the upper surface of the workpiece crosses at two points with said circle defined by the edge tip of the cutting edge portion of the cutter, (c) the working plane of the cutter is inclined relative to the edge of the workpiece to be chamfered such that the working plane crosses with the edge of the workpiece at only the front portion of the cutter working plane in a moving direction of the workpiece so as to allow the edge of the workpiece to be chamfered only at the single cross point thereby formed, and (d) rotation of the circular cutter is permitted such that, for a projection of the cutter onto the lower surface of the workpiece, the edge of the cutting edge portion of the cutter is moved at the cross point from an overlapping region between the projection of the cutter and the workpiece to a non-overlapping region thereof; rotating the cutter; and moving the workpiece in a direction of a sense opposite to that of movement of the cutting edge portion of the cutter at the cross point so that successive portions of the edge of the workpiece to be chamfered engage the cross point thereby chamfering the edge at the cross point.

Claim 4

A method of chamfering an edge of a plate-like workpiece, especially a workpiece made of a silicon steel plate, comprising the steps of: providing a rotating circular cutter having a ring-shaped cutting edge portion formed along a periphery of a holder thereof, the cutting edge portion having an edge tip defining a circle, said edge tip having a rake angle within the range of 0 to -1.0 degrees and a relief angle which has a zero or positive angle; orienting the cutter to the workpiece so that the edge of the workpiece to be chamfered engages the edge tip at only one portion of the circle as the workpiece moves with respect to the cutter to engage various portions of the edge to be chamfered, this step of orienting including establishing positional relationships such that: (a) the angel formed between a lower surface of the workpiece and the working plane of the cutter, which plane includes a circle defined by the edge tip of the cutting edge portion of the cutter, falls within the range of 0° to 45°, (b) the plane including the upper surface of the workpiece crosses at two points with said circle defined by the edge tip of the cutting edge portion of the cutter, (c) the working plane of the cutter is inclined relative to the edge of the workpiece to be chamfered such that the working plane crosses with the edge of the workpiece at only the front portion of the cutter working plane in a moving direction of the workpiece so as to allow the edge of the workpiece to be chamfered only at the single cross point thereby formed, and (d) rotation of the circular cutter is permitted such that, for a projection of the cutter onto the lower surface of the workpiece, the edge of the cutting edge portion of the cutter is moved at the cross point from an overlapping region between the projection of the cutter and the workpiece to a non-overlapping region thereof; rotating the cutter; and moving the workpiece in a direction of a sense opposite to that of movement of the cutting edge portion of the cutter at the cross point so that successive portions of the edge of the workpiece to be chamfered engage the cross point thereby chamfering the edge at the cross point.