Wire electrical discharge machining apparatus

A wire electrical discharge machining apparatus that applies a pulse voltage between a wire electrode and a workpiece while relatively moving the wire electrode and the workpiece by a drive device based on an NC program, the wire electrical discharge machining apparatus comprising:

• a representative speed calculation device that calculates a representative speed of a straight part when the straight part is being machined;
• a pre-corner section length calculation device that calculates the length of a pre-corner section in which a machining volume changes transitionally before an entrance of a corner part when the corner part is detected by the NC program;
• a post-corner section length calculation device that calculates the length of a post-corner section in which a machining volume changes transitionally before an exit of the corner part;
• a corner speed coefficient calculation device that calculates a machining speed ratio between a middle corner section and the straight part from a machining volume ratio between the straight part and the middle corner section in which the machining volume of the corner part becomes a constant value;
• a corner speed coefficient interpolation device that interpolates a corner speed coefficient calculated by the corner speed coefficient calculation device in the pre-corner section and the post-corner section;
• a speed reference calculation device that calculates a machining speed reference of the corner part based on the representative speed and the corner speed coefficient interpolated by the corner speed coefficient interpolation device;
• and
• a drive control device that controls the drive device by the machining speed reference calculated by the speed reference calculation device,
• wherein when an inside corner is continuous to an outside corner, the speed reference calculation device sets the machining speed reference in a section having overlapping continuous corners to be equal to or larger than a machining speed reference of a post-section of a single inside corner and equal to or smaller than a machining speed reference of a pre-section of a single outside corner.

A wire electrical discharge machining apparatus that applies a pulse voltage between a wire electrode and a workpiece while relatively moving the wire electrode and the workpiece by a drive device based on an NC program, the wire electrical discharge machining apparatus comprising:

• a representative speed calculation device that calculates a representative speed of a straight part when the straight part is being machined;
• a pre-corner section length calculation device that calculates the length of a pre-corner section in which a machining volume changes transitionally before an entrance of a corner part when the corner part is detected by the NC program;
• a post-corner section length calculation device that calculates the length of a post-corner section in which a machining volume changes transitionally before an exit of the corner part;
• a corner speed coefficient calculation device that calculates a machining speed ratio between a middle corner section and the straight part from a machining volume ratio between the straight part and the middle corner section in which the machining volume of the corner part becomes a constant value;
• a corner speed coefficient interpolation device that interpolates a corner speed coefficient calculated by the corner speed coefficient calculation device in the pre-corner section and the post-corner section;
• a speed reference calculation device that calculates a machining speed reference of the corner part based on the representative speed and the corner speed coefficient interpolated by the corner speed coefficient interpolation device;
• and
• a drive control device that controls the drive device by the machining speed reference calculated by the speed reference calculation device,
• wherein when an outside corner is continuous to an inside corner, the speed reference calculation device sets the machining speed reference in a section having overlapping continuous corners to be equal to or smaller than a machining speed reference of a post-section of a single outside corner and equal to or larger than a machining speed reference of a pre-section of a single inside corner.