Chung Yuan Christian University

Chien-Da Ho

Shih-Ming Wang

Yan-Ting Chen

I-Feng Lo

Shi-Hsi Liu

A build up edge monitoring method is provided for performing online real-time detection and suppression of abnormal build up edges of cutters occurred in a CNC manufacturing process. Signal variation analysis and fast Fourier transform are used for analyzing signals and establishing an algorithm of diagnosing build up edges to improve the efficiency and reliability of the cutting abnormality diagnostics. A vibration acceleration signal is captured and filtered to a frequency exceeding 1.1 times of a blade passing frequency, and an occurrence of accumulated chips is determined according to a sudden increase of the vibration acceleration and whether the main vibration frequency of the current vibration signal determined by a fast Fourier transform analysis matches with the frequency of the build up edge characteristic, and a shutdown instruction is issued to a CNC controller to shut down a cutting machine.

Build up edge monitoring method

A cutter chatter monitoring method comprises the steps of capturing a cutting vibration acceleration signal; dividing the cutting vibration acceleration signal in each predetermined time period into a plurality of segments; determining whether the vibration acceleration signal of each segment is increased by a multiple greater than a threshold value; performing a Fast Fourier Transform of the cutting vibration acceleration signal in each predetermined time period; calculating a vibration frequency; determining whether the vibration frequency of the cutting vibration acceleration signal is a multiple of a cutter passing frequency; and increasing a main shaft rotating speed of a cutter to avoid cutter chatters if both aforementioned conditions are satisfied.

Cutter chatter monitoring method

An online real-time cutter breakage monitoring method uses a plurality of signals generated in three consecutive time periods by a vibration acceleration during a cutting process conducted by a CNC machine tool, and compares a difference between a maximum value of signals in each time period and an average value of the signals and a difference between the average value of signals thereafter and an idling critical value to output a first cutter breakage signal and a second cutter breakage signal simultaneously and determine the occurrence of a cutter breakage and shut down the CNC machine tool immediately to improve the determination speed and accuracy, so as to avoid unnecessary shutdowns or hindering the manufacturing flow.

Online real-time cutter breakage monitoring method

A powder allotting device comprises a supporting device, a coupling device, and a separating device. The supporting device is a base of the powder allotting device, and the supporting device is coupled to the separating device by the coupling device. The a separating device further comprises a rotary plate with a curved grooved structure, a plurality of movable valves, a scraper, and a cylinder with a plurality of T-shape grooves, and a plurality of slices. The plurality of slices are inserted into the T-shape grooves and enter the curved grooved structure, moving up and down the T-shape grooves.

Growing community of inventors

Taoyuan County, Taiwan

Chien-Da Ho