Method of determining electric discharge machining conditions and electric discharge machining controller

An electric discharge machining controller for controlling electric discharge machining conditions in a machining gap formed between an electrode and a workpiece during electric discharge machining of the workpiece, based on a set of predefined machining parameters including machining area, electrode undersize, machining depth, electrode material and workpiece material, said controller comprising:

• means for inputting desired predefined machining parameters;
• means for storing data files for different electrode materials, workpiece materials and machining areas, each data file including multiple sets of basic machining data indicative of relationships among electric discharge machining current, machining depth and minimum electrode side surface undersize during electric discharge machining;
• means responsive to the predefined machining parameters for selecting vicinal data closely related to the given predefined machining parameters from among the multiple sets of basic machining data in the means for storing;
• means for inferring and generating machining condition data representing a series of pairs of machining depth values and corresponding electric discharge machining current values required for machining the workpiece to a prescribed configuration and dimensions, the electric discharge machining current values in the series of pairs of values progressively changing with increasing machining depth value from a maximum permissible value consistent with the set electrode side surface undersize to a smaller value consistent with the set machining depth;
• means for detecting actual machining depth value;
• and
• means responsive to the detecting means and machining condition data obtained in the inferring and generating step for changing the electric discharge machining current value in accordance with an increase in the actual machining depth.

An electric discharge machining controller for controlling electric discharge machining conditions in a machining gap formed between an electrode and a workpiece during electric discharge machining of the workpiece based on a set of predefined machining parameters including machining area, electrode undersize, machining depth, electrode material and workpiece material, said controller comprising:

• means for inputting desired predefined machining parameters;
• means for storing data files for different electrode materials, workpiece materials and machining areas, each data file including multiple sets of basic machining indicative of relationships among electric discharge machining current, machining depth and minimum electrode side surface undersize during electric discharge machining;
• a first selecting means responsive to the predefined machining parameters for selecting first vicinal data closely related to the given predefined machining parameters from among the multiple sets of basic machining data stored in the storing means;
• means for forming a first neural network, on the basis of the first vicinal data, for inferring an electric discharge current value from the given predefined machining parameters;
• means for inferring and generating an electric discharge machining current value for use in a final machining step in accordance with the first neural network by use of the predefined machining parameters;
• a second selecting means, responsive to the means for inferring and generating an electric discharge machining current value, for selecting second vicinal data closely related to the electric discharge machining current value for the final machining step from among the multiple sets of basic machining data stored in the means for storing;
• means for forming a second neural network for inferring a minimum side surface undersize on the basis of the second vicinal data;
• means for inferring and generating a minimum side surface undersize value corresponding to the electric discharge machining current value to be used for the final machining step and given predefined machining parameters including machining area and machining depth;
• means responsive to the minimum side surface undersize value for generating a series of pairs of machining depth values and corresponding electric discharge machining current values required for machining the workpiece to a prescribed configuration and dimensions, the electric discharge machining current values in the series progressively changing with increasing machining depth value from a maximum permissible value consistent with the set electrode side surface undersize to a smaller value consistent with the set machining depth;
• means for detecting actual machining depth;
• and
• means responsive to the detecting means, minimum side surface undersize value and corresponding machining current values for changing the electric discharge machining current in accordance with the actual machining depth.

A method of determining optimum electric discharge machining conditions in a machining gap formed between an electrode and a workpiece corresponding to a set of predefined machining parameters including machining area, electrode undersize, machining depth, electrode material and workpiece material using data stored in advance in a memory, said data comprising multiple sets of predefined machining parameters, said method comprising the steps of:

• establishing multiple sets of basic machining data, each corresponding to a set of predefined machining parameters, each of the sets of basic machining data being indicative of relationships among electric discharge machining current, machining depth and minimum electrode side surface undersize present during electric discharge machining;
• selecting at least two sets of basic machining data from among the multiple sets thereof in accordance with a given set of predefined machining parameters, and
• inferring and generating machining condition data representing a series of pairs of machining depth values and corresponding electric discharge machining current values required for machining the workpiece to a prescribed configuration and dimensions, the electric discharge machining current values in the series progressively changing with increasing machining depth value from a maximum permissible value consistent with the set electrode side surface undersize to a smaller value consistent with the actual machining depth.

A method of determining electric discharge machining conditions in a machining gap formed between an electrode and a workpiece on the basis of a set of predefined machining parameters including machining depth and electrode undersize, the method comprising the steps of:

• setting a set of predefined machining parameters including machining depth and electrode undersize;
• establishing a data file including multiple sets of basic machining dam indicative of relationships among electric discharge machining current, a machining depth and minimum electrode undersize;
• selecting at least two sets of basic machining data from among the multiple sets thereof, said at least two sets of basic machining data including data corresponding to or adjacent to the set values of machining depth and electrode undersize;
• and
• inferring an electric discharge machining current value on the basis of said at least two sets of basic machining data, the inferred electric discharge machining current value being the maximum permissible to be supplied to the machining gap when machining with electrode having the set electrode undersize at the set machining depth.

A method of determining electric discharge machining conditions in a machining gap formed between an electrode and a workpiece on the basis of a set of predefined machining parameters including machining depth, electrode undersize and machining area, the method comprising the steps of:

• setting a set of predefined machining parameters including machining depth, electrode undersize and machining area;
• establishing multiple data files for different machining areas, each of said data files including multiple sets of basic machining data being indicative of relationships among electric discharge machining current, machining depth and minimum electrode undersize;
• selecting at least one data file from among multiple data files in accordance with the set machining area;
• selecting at least two sets of basic machining data from among the multiple sets thereof in the selected data file, said at least two sets of basic machining data including data corresponding to or adjacent to the set values of machining depth and electrode undersize;
• and
• inferring electric discharge machining current on the basis of said at least two sets of basic machining data.

A method of determining electric discharge machining conditions in a machining gap formed between an electrode and a workpiece on the basis of a set of predefined machining parameters including machining depth and electrode undersize, the method comprising the steps of:

• establishing a data file including multiple sets of basic machining data indicative of relationships among electric discharge machining current, machining depth and minimum electrode undersize;
• determining a first value of electric discharge machining current, a first value of machining depth and electrode undersize;
• selecting at least two sets of basic machining data from among the multiple sets thereof, said at least two sets of basic machining data including data corresponding to or adjacent to the electrode undersize and a second value of electric discharge machining current which is larger than said first value thereof;
• and
• inferring a second value of machining depth on the basis of said at least two sets of basic machining data, said electric discharge machining current being changed from said second value to said first value thereof when machining depth reaches said second value thereof which is smaller than said first value thereof during machining.

An electric discharge machining controller for controlling electric discharge machining conditions in a machining gap formed between an electrode and a workpiece based on a set of predefined machining parameters including machining depth and electrode undersize, said controller comprising:

• means for setting a set of predefined machining parameters including machining depth and electrode undersize;
• a memory for storing data files including multiple sets of basic machining data indicative of relationships among electric discharge machining current machining depth and minimum electrode undersize;
• selecting means for selecting at least two sets of basic machining data from among the multiple sets thereof, said at least two sets of basic machining data including data corresponding to or adjacent to the set values of machining depth and electrode undersize;
• and
• means for inferring electric discharge machining current value on the basis of said at least two sets of basic machining data.