CN2225929Y

CN2225929Y - Sound emission contact monitor

Info

Publication number: CN2225929Y
Application number: CN 95215310
Authority: CN
Inventors: 罗振璧; 郑力; 汪劲松; 杨世明; 齐卫东; 楼和姣
Original assignee: Wuxi Machine Tool Ltd By Share Ltd Grinding Machine Research Institute; Tsinghua University
Current assignee: Wuxi Machine Tool Ltd By Share Ltd Grinding Machine Research Institute; Tsinghua University
Priority date: 1995-07-07
Filing date: 1995-07-07
Publication date: 1996-05-01
Anticipated expiration: 2005-07-07

Abstract

The utility model relates to a sound emission contact monitor, which belongs to the field of measuring apparatus of the machine tool. The monitor comprises two parts of the acoustic emission sensor and the signal processing and alarm system. The signal processing and alarm system comprises a pre-amplifier circuit, a bandwidth limited circuit, a main amplifier circuit, a primary envelope-forming circuit, a hardware recognizing and processing circuit and a sound and optical alarm circuit. Because the 0-1 M H z signal is adopted as the judging signal frequency range by the monitor, the burst of the ambient noise is charged off, the signal-to-noise ratio is enhanced, the rate of false alarm is decreased and the alarm is correct and fast.

Description

A kind of acoustic emission contact supervising device

The utility model relates to the contact detecting apparatus of cutter and workpiece in the mechanical processing process, belongs to the measurement mechanism field on the lathe.

In the machining, accurately detect cutter and contact, judge that contact position provides the feed starting point to guarantee machining accuracy with workpiece.Simultaneously, The real time measure feed starting point can realize process automation, shortens the idle running time, improves machining accuracy and production efficiency, reduces production costs.Especially in grinding, along with development efficient, the flexible automation Grinding Technology, the real time information of obtaining the contact of emery wheel one workpiece has become the important key technology of high efficient grinding and numerically control grinder grinding process supervision (control).

Detecting cutter at present has a variety of to the detection method that workpiece contacts, but its response time is longer, (as the current power method), shorter when adopting its response of acoustic emission detection method, but existing acoustic emission detection system is responsive to ambient noise, wrong report easily, and poor anti jamming capability, the influence of very noisies such as mechanical, electrical at the scene, liquid are down, and signal to noise ratio is low, usually be difficult to discern contact process, the warning success rate is low.

The purpose of this utility model provides a kind of warning accurately and reliably, precision height, sensitivity, the acoustic emission contact supervising device that antijamming capability is strong.

The utility model acoustic emission contact supervising device is handled by calibrate AE sensor and signal and warning system two parts are formed.Calibrate AE sensor can be conventional broadband acoustic emission probe, signal handle and warning system by preamplifier, bandwidth-limited circuit, main amplifying circuit, acoustic emission signal first enveloped formation circuit, the hardware identification processes circuit, sound light alarming circuit is formed.When contacting with workpiece, emery wheel produces acoustic emission, sensor picks up acoustic emission signal, the input pre-amplification circuit, carry out preposition amplification and high-pass filtering, the elimination low frequency signal, signal enters bandwidth-limited circuit then, the signal of other frequency ranges of elimination, the signal that keeps 0-1MHZ, enter main amplifying circuit then acoustic emission signal is amplified, obtain the acoustic emission waveform as Fig. 1, the signal after the amplification enters first enveloped and forms circuit, acoustic emission signal after amplifying is carried out envelope detection, obtain waveform as shown in Figure 2.The first enveloped signal enters the hardware identification processes circuit, compares with preset threshold value, when the first enveloped signal value surpasses preset threshold value, then sends and drives that signal enabling sound, optical alarm circuit carry out sound, light is reported to the police.

Illustrate that accompanying drawing is as follows:

Fig. 1 is acoustic emission signal waveform figure.

Fig. 2 is an acoustic emission signal first enveloped oscillogram.

Fig. 3 is the utility model circuit theory diagrams.

Fig. 4 is 5 volts of DC levels and switch warning circuit.

Fig. 5 is the instrument working control circuit.

Accompanying drawings embodiment is as follows:

The utility model acoustic emission contact supervising device is handled by calibrate AE sensor and signal and warning system two parts are formed, and the acoustic emission sonic transducer can adopt broadband water proof type calibrate AE sensor.Signal processing and warning system form circuit (IV), hardware identification processes circuit (V), sound light alarming circuit (VI) and power supply (VII) by preamplifier (I), bandwidth-limited circuit (II), main amplifying circuit (III), acoustic emission signal first enveloped and form; (see figure 3) pre-amplification circuit (I) has resistance R 1-R16, capacitor C 1-C7, and diode D1-D2 inductance L, triode T0-T4 forms.Noise signal is eliminated in wherein capacitor C 3-C4 and the high-pass filtering of inductance L structure horse, triode T1-T4, and diode D1-D2, resistance R 7-R16, capacitor C 5-C7 forms amplifying circuit; Bandwidth-limited circuit (II) is by resistance R 17-R24, capacitor C 8-C13, integrated transporting discharging A1-A5 forms, the output signal of amplifier A1 coupling preamplifier, capacitor C 8-C11, resistance R 17-R18, integrated transporting discharging A2-A4 constitutes high-pass filter, capacitor C 12-C13, resistance R 19-R24 integrated transporting discharging A4-A5 constitutes low-pass filter circuit, and main amplifying circuit (III) is by potentiometer W1, and resistance R 25-R30 transport and placing device A6-A7 forms, resistance R 25-R30 and amplifier A6-A7 constitute amplifying circuit, and potentiometer W1 is used for regulating multiplication factor; First enveloped forms circuit (IV) by resistance R 31-R44, capacitor C 14-C18, triode T5-T6, integrated transporting discharging A8, diode D3-D4 potentiometer W2 forms capacitor C 14-C16, resistance R 31-R35, triode T5-T6 forms the impedance conversion, diode D3-D4, and capacitor C 17-C18 constitutes the rectification circuit; Resistance R 36-R44, potentiometer W2 and integrated transporting discharging A8 constitute differential amplifier circuit; Hardware identification processes circuit (V) is by potentiometer W3, resistance R 45-R61, and integrated transporting discharging A10-A14 NAND gate IC3, integrated holding circuit A14 forms, and potentiometer W3 wherein, resistance R 4-R50, integrated transporting discharging A12-A13 constitute and set threshold circuit; Resistance R 58-R61, capacitor C 19 NAND gate IC4 integrated transporting discharging A14, integrated holding circuit A15 forms the static noise rejection circuit; Integrated transporting discharging A10-A11, trigger IC1-IC2, NAND gate IC3 constituent ratio is than circuits for triggering; Sound light alarming circuit (VI) is by loudspeaker B1, luminous tube B2, and resistance R 52-R55, triode T7-T8 forms.

When NAND gate IC3 output and 5 volts of DC levels and switch warning circuit (Fig. 4) when linking to each other, send alarm signal after, this circuit can start lathe and move.When instrument working control circuit (Fig. 5) links to each other with K switch 1, can control the work of this supervising device by lathe.

Illustrate that 5 volts of DC levels and switch warning circuit and instrument working control circuit are as follows:

Fig. 4 is 5 volts of DC levels and switch warning circuit, this circuit is made up of resistance R 63-R68, optocoupler IC6, triode T9-T10, diode D1, relay J, voltage-stabiliser tube DZ etc., wherein resistance R 63, diode D5, relay J, triode T10 form the alarm relay circuit, go to control the lathe action; Resistance R 64-R68, optocoupler IC6, triode T9, voltage-stabiliser tube DZ form 5 volts of DC level warning circuits.

Fig. 5 is the instrument working control circuit, is made up of K switch 2, resistance R 62, optocoupler IC5.The output of instrument working control circuit links to each other with the common port of KI and R51.

The processing of the utility model signal and the warning system course of work are as follows:

The acoustic emission signal that calibrate AE sensor is picked up enters pre-amplification circuit (I) via socket TJ (Fig. 3), elimination noise and amplification (as Fig. 1 waveform), acoustic emission signal after the amplification enters bandwidth-limited circuit (II), elimination low frequency and high-frequency signal, the signal that keeps 0-1MHZ, entering main amplifying circuit (III) then amplifies, signal after the amplification enters first enveloped and forms circuit (IV), carry out shaping and detection, get first enveloped signal (as the waveform of Fig. 2), the first enveloped signal enters hardware and knows treatment circuit (V), in the hardware identification processes circuit, the first enveloped signal with compare by setting the preset value that threshold circuit sets, when the first enveloped signal amplitude surpasses the threshold value of setting, i.e. start signal output sound, optical alarm circuit (VI) is reported to the police.

The utility model acoustic emission contact monitoring device has improved signal to noise ratio because the signal that has adopted 0-1MHZ as judging the signal frequency range, and takes interference protection measure to reject influences such as ambient noise, has reduced rate of false alarm, and it is rapidly correct to report to the police.

Claims

1, a kind of by calibrate AE sensor, the acoustic emission contact supervising device that signal is handled and warning system is formed, it is characterized in that signal processing and warning system are by preamplifier, bandwidth-limited circuit, main amplifying circuit, the acoustic emission signal first enveloped forms circuit, the hardware identification processes circuit, sound, optical alarm circuit and power supply are formed, said pre-amplification circuit has resistance R 1-R16, capacitor C 1-C7, inductance L, diode D1-D2, triode T0-T4 forms, and wherein capacitor C 3-C4 and inductance L constitute high-pass filtering, triode T1-T4, diode D1-D2, resistance R 7-R16, capacitor C 5-C7 constitutes amplifying circuit; Said bandwidth-limited circuit is by resistance R 17-R24, capacitor C 8-C13, integrated transporting discharging A1-A5 forms, amplifier A1 wherein, the output signal of coupling preamplifier, capacitor C 8-C13, resistance R 17-R18, integrated transporting discharging A2-A3 constitute high-pass filtering circuit, and capacitor C 12-C13, resistance R 19-R24, integrated transporting discharging A4-A5 constitute low-pass filter circuit; Said main amplifying circuit is by potentiometer W1, and resistance R 25-R30 integrated transporting discharging A6-A7 forms, and wherein, resistance R 25-R30, integrated transporting discharging A6-A7 constitute amplifying circuit, and potentiometer W1 is used for regulating multiplication factor; Said first enveloped forms circuit and is made up of resistance R 31-R44, capacitor C 14-C16, triode T5-T6, integrated transporting discharging A8, diode D3-D4, potentiometer W2, wherein capacitor C 14-C16, resistance R 31-R35, triode T5-T6 constitutes the impedance conversion, diode D3-D4, capacitor C 17-C18 constitute the shaping detecting circuit, and resistance R 36-R44, potentiometer W2 and integrated transporting discharging A8 constitute differential amplifier circuit; Said hardware identification processes circuit is made up of potentiometer W3, resistance R 45-R61, integrated transporting discharging A10-A14 NAND gate IC3, the integrated holding circuit A15 of trigger IC1-IC2, wherein potentiometer W3, resistance R 45-R50, integrated transporting discharging A12-A13 constitute the setting threshold circuit, resistance R 58-R61, capacitor C 19, NAND gate IC4, integrated transporting discharging A14, integrated holding circuit A15 constitute the static noise rejection circuit, and integrated transporting discharging A10-A11, trigger IC1-IC2, NAND gate IC3 constituent ratio are than circuits for triggering; Said sound, optical alarm circuit are made up of loudspeaker B1, luminous tube B2, resistance R 52-R55, triode T7-T8.