Vibration determination method and vibration determination device
First Claim
1. A vibration determination method for determining a type of chatter vibration occurring in a rotary shaft in a machine tool that has the rotary shaft rotating a tool or a workpiece comprising:
- a first step for detecting time-domain vibration of the rotary shaft and rotation speed of the rotary shaft during rotation;
a second step for calculating frequency-domain vibration based on the time-domain vibration, and obtaining a plurality of peak values and peak frequencies corresponding to each of the plurality of peak values in the calculated frequency-domain vibration;
a third step for obtaining a synchronizing type vibration range for determining the type of the chatter vibration using the peak frequencies correspond to each of the plurality of peak values; and
a fourth step for determining whether the type of the chatter vibration is a forced chatter vibration of a synchronizing type vibration based on a relation between the peak frequencies and corresponding peak values and the synchronizing type vibration range obtained using the peak frequencies.
1 Assignment
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Accused Products
Abstract
Determination of chatter vibration is done for a plurality of peak values that appears when frequency-domain vibrational acceleration is obtained through fast Fourier analysis on time-domain vibrational acceleration. In machining at a low rotation speed and machining using a tool with small flute number in particular, a type of chatter vibration that has occurred can be accurately determined, and “natural type vibration” occurring due to friction between a tool and a workpiece and an impact force caused by machining can also be determined.
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Citations
10 Claims
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1. A vibration determination method for determining a type of chatter vibration occurring in a rotary shaft in a machine tool that has the rotary shaft rotating a tool or a workpiece comprising:
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a first step for detecting time-domain vibration of the rotary shaft and rotation speed of the rotary shaft during rotation; a second step for calculating frequency-domain vibration based on the time-domain vibration, and obtaining a plurality of peak values and peak frequencies corresponding to each of the plurality of peak values in the calculated frequency-domain vibration; a third step for obtaining a synchronizing type vibration range for determining the type of the chatter vibration using the peak frequencies correspond to each of the plurality of peak values; and a fourth step for determining whether the type of the chatter vibration is a forced chatter vibration of a synchronizing type vibration based on a relation between the peak frequencies and corresponding peak values and the synchronizing type vibration range obtained using the peak frequencies. - View Dependent Claims (2, 3)
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4. A vibration determination method for determining a type of chatter vibration occurring in a rotary shaft in a machine tool that has the rotary shaft rotating a tool or a workpiece comprising:
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a first step for detecting time-domain vibration of the rotary shaft and rotation speed of the rotary shaft during rotation; a second step for calculating frequency-domain vibration based on the time-domain vibration, and obtaining a plurality of peak values and peak frequencies corresponding to each of the plurality of peak values in the calculated frequency-domain vibration; a third step for obtaining a natural type vibration range for determining the type of the chatter vibration based on the plurality of peak frequencies; and a fourth step for determining whether the type of the chatter vibration is a forced chatter vibration of a natural type vibration or a regenerative chatter vibration based on a number of the peak values having corresponding peak frequencies that are included in the natural type vibration range. - View Dependent Claims (5, 6, 7, 8)
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9. A vibration determination device that determines, in a machine tool that has a rotary shaft rotating a tool or a workpiece, a type of chatter vibration occurring in rotating the rotary shaft comprising:
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a detection unit that detects time-domain vibration of the rotary shaft and rotation speed of the rotary shaft during rotation; an FFT calculation unit that calculates frequency-domain vibration based on the time-domain vibration detected by the detection unit, and obtains a plurality of peak values and peak frequencies corresponding to each of the plurality of peak values in the calculated frequency-domain vibration; a determination unit that obtains a synchronizing type vibration range for determining the type of the chatter vibration using the peak frequencies corresponding to each of the plurality of peak values, and determines whether the type of the chatter vibration is a forced chatter vibration of a synchronizing type vibration based on a relation between the peak frequencies and corresponding peak values and the synchronizing type vibration range obtained using the peak frequencies; and a display unit that displays the type of the chatter vibration determined.
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10. A vibration determination device that determines, in a machine tool that has a rotary shaft rotating a tool or a workpiece, a type of chatter vibration occurring in rotating the rotary shaft comprising:
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a detection unit that detects time-domain vibration of the rotary shaft and rotation speed of the rotary shaft during rotation; an FFT calculation unit that calculates frequency-domain vibration based on the time-domain vibration detected by the detection unit, and obtains a plurality of peak values and peak frequencies corresponding to each of the plurality of peak values in the calculated frequency-domain vibration; a determination unit that obtains a natural type vibration range for determining the type of the chatter vibration based on the plurality of peak frequencies, and determines whether the type of the chatter vibration is a forced chatter vibration of a natural type vibration or a regenerative chatter vibration based on the number of the peak values where having corresponding peak frequencies that are included in the natural type vibration range; and a display unit that displays the type of the chatter vibration determined.
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Specification