Method of evaluating a machined surface of a workpiece, a controlling apparatus and a machine tool

The method according to any one the previous claims, comprising the steps of:

• simulating the machined surface of a workpiece by calculation;
• calculating the maximum minimum luminance of reflecting light on the machined surface;
• calculating contrast based on the maximum minimum luminance;
• calculating spatial frequency of the machined surface;
• and
• determining whether or not the contrast of the machined surface can be visibly detected by the human visual perception, by using a contrast sensitivity function, based on the contrast and the spatial frequency.

A control device for a feed axis of a machine tool, comprising:

• a machined surface shape simulating section for simulating the machined surface of a workpiece by a calculation;
• a contrast calculating section for calculating the maximum minimum luminance of reflecting light on the machined surface whereby the contrast is calculated based on the maximum minimum luminance;
• spatial frequency calculating section for calculating spatial frequency of the machined surface;
• judging section for determining whether or not the contrast of the machined surface can be visibly detected by the human visual perception, by using a contrast sensitivity function, based on the contrast and the spatial frequency;
• and
• a machining process modifying section for modifying a machining process, when the contrast of the processed surface is detectable by human visual perception, so that the contrast of the processed surface cannot be detected by human visual perception.

A control apparatus for a feed axis of a machine tool, comprising:

• a machined surface shape simulating section for simulating a machined surface of a workpiece by a calculation;
• a vibration stimulus frequency calculating section for calculating vibration stimulus frequency transmitted to a finger of an observer when the observer fingers the machined surface simulated by the machined surface simulating section;
• a judging section for determining whether or not the amplitude of the vibratory stimulation, transmitted to the finger of the observer, can be detected by human tactile sense, relative to the frequency of the vibratory stimulation calculated by the vibration stimulus frequency calculating section, the amplitude of the vibratory stimulation being obtained based on the distance between peaks of cusps formed on the machined surface simulated by the machined surface simulating section, and the speed of the finger of the observer;
• and
• a process modifying section for modifying a machining process, when the amplitude of vibratory stimulation can be detected by human tactile sense so that the amplitude of vibratory stimulation cannot be detected by human tactile sense.

A machine tool having at least three orthogonal feed axes of X-, Y- and Z-axes for relatively moving a tool to a workpiece, comprising:

• a drive mechanism for driving the three feed axes;
• an NC device for controlling the drive mechanism;
• and
• an evaluating apparatus for simulating a machined surface formed on the workpiece;
• characterized in that the evaluating apparatus comprising:
• a machined surface shape simulating section for simulating the machined surface of a workpiece by a calculation;
• a contrast calculating section for calculating the maximum minimum luminance of reflecting light on the machined surface whereby the contrast is calculated based on the maximum minimum luminance;
• spatial frequency calculating section for calculating spatial frequency of the machined surface;
• judging section for determining whether or not the contrast of the machined surface can be visibly detected by the human visual perception, by using a contrast sensitivity function, based on the contrast and the spatial frequency;
• and
• a machining process modifying section for modifying a machining process, when the contrast of the processed surface is detectable by human visual perception, so that the contrast of the processed surface cannot be detected by human visual perception, whereby a tool path and a machining condition are sent to the NC device, based on the modified machining process.

A machine tool having at least three orthogonal feed axes of X-, Y- and Z-axes for relatively moving a tool to a workpiece, comprising:

• a drive mechanism for driving the three feed axes;
• an NC device for controlling the drive mechanism;
• and
• an evaluating apparatus for simulating a machined surface formed on the workpiece;
• characterized in that the evaluating apparatus comprising:
• a machined surface shape simulating section for simulating a machined surface of a workpiece by a calculation;
• a vibration stimulus frequency calculating section for calculating vibration stimulus frequency transmitted to a finger of an observer when the observer fingers the machined surface simulated by the machined surface simulating section;
• a judging section for determining whether or not the amplitude of the vibratory stimulation, transmitted to the finger of the observer, can be detected by human tactile sense, relative to the frequency of the vibratory stimulation calculated by the vibration stimulus frequency calculating section, the amplitude of the vibratory stimulation being obtained based on the distance between peaks of cusps formed on the machined surface simulated by the machined surface simulating section, and the speed of the finger of the observer;
• and
• a process modifying section for modifying a machining process, when the amplitude of vibratory stimulation can be detected by human tactile sense, so that the amplitude of vibratory stimulation cannot be detected by human tactile sense, whereby a tool path and a machining condition are sent to the NC device, based on the modified machining process.