Electrical discharge machining method for generating variable spray-hole geometry

A method for operating an apparatus for forming a hole in a workpiece, comprising:

• commanding a guide assembly of the apparatus to position a first end of an electrode in direction of an alignment point of the workpiece, the alignment point being located along a central longitudinal axis of the workpiece;
• commanding a logic circuit of the apparatus to apply a first voltage to the electrode wherein the applied voltage generates a spark;
• commanding the guide assembly of the apparatus to rotate the electrode in a first direction at an angle relative to the central longitudinal axis;
• commanding the guide assembly of the apparatus to advance the electrode toward the alignment point by a first distance wherein advancing the electrode and applying the first voltage create a first orifice section;
• commanding the logic circuitthe apparatus to apply a second voltage to the electrode by at least:
• adjusting a voltage applied to the electrode;
• commanding the logic circuit of the apparatus to modify one or more operational parameters of the electrode such that the guide assembly advances the electrode toward the alignment point by a second distance after the guide assembly advances the electrode toward the alignment point by the first distance, the one or more operational parameters including a parameter controlling an amount by which the electrode is angled relative to the central longitudinal axis;
• and
• commanding the guide assembly of the apparatus to advance the electrode toward the aligiment point by the second distance wherein advancing the electrode and applying the second voltage create a second orifice section, wherein the first, orifice section and the second orifice section form at least a first portion of an orifice comprising a first flow area associated with the first orifice section and a second flow area associated with the second orifice section, wherein the first flow area is greater than the second flow area.

An apparatus for forming a hole in a workpiece, comprising:

• a controller including one or more processors and a memory;
• a guide assembly coupled to the controller;
• and
• an electrode coupled to the guide assembly;
• the memory including instructions that, when executed by the one or more processors, cause:
• the guide assembly to rotate the electrode in a first direction at an angle relative to a central longitudinal axis of the workpiece;
• the electrode to produce one or more sparks having different voltage characteristics when the one or more sparks are directed toward an alignment point of the workpiece, the alignment point being located along the central longitudinal axis;
• the controller to command a first voltage to be applied to the electrode and adjust one or more operational parameters of the electrode and the guide assembly to advance the electrode toward the alignment point by a first distance to create a first orifice section, the one or more operational parameters including a parameter controlling an amount by which the electrode is angled relative to the central longitudinal axis;
• the controller to command a second voltage to be applied to the electrode by at least adjusting a voltage applied to the electrode;
• the controller to adjust the one or more operational parameters of the electrode and the guide assembly to advance the electrode toward the alignment point by a second distance to create a second orifice section after the guide assembly advances the electrode toward the alignment point by the first distance. wherein the first orifice section and the second orifice section form at least a first portion of an orifice comprising a first flow area associated with the first orifice section and a. second,flow area associated with the second orifice section, wherein the first flow area is greater than the second flow area.