CN2248118Y

CN2248118Y - Phase-locked frequency tracking ultrasonic polishing machine

Info

Publication number: CN2248118Y
Application number: CN 95246523
Authority: CN
Inventors: 宣浩
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-11-28
Filing date: 1995-11-28
Publication date: 1997-02-26
Anticipated expiration: 2005-11-28

Abstract

The utility model relates to a phase-locked frequency tracking ultrasonic polishing machine, comprising a transducer (1), an amplitude changing rod (2), a tool head (3) and a main machine. An ultrasonic vibration electric signal generating circuit of the transducer (1) comprises a press control vibration circuit (1), two frequency division circuits (2), a power amplified circuit (3), a matching circuit (4). A current sample circuit (6) gets current signals of the transducer via a first coil L2 of a current transformer B2 connected in series to the piezoelectric transducer (5), and then the current signals are shaped into square waves which is as input signals of a phase difference detection circuit (7); after compared with the output signals of the frequency division circuits (2), the square waves are exported to control the press control input of the press control vibration circuit (1). The circuit structure of the utility model is simple, and the work is reliable.

Description

Phase-locking type frequency-tracking ultrasonic polishing machine

The utility model relates to a kind of grinding machinery that utilizes ultrasonic wave to carry out surperficial machining, a kind of phase-locking type frequency-tracking ultrasonic polishing machine.

The ultrasonic polishing machine is mainly used in the Mould Machining industry at present, to through car, mill, processed workpiece surfaces such as electric spark and line cutting polish, its operation principle is to utilize transducer to convert mechanical oscillation to by the signal of telecommunication that the sonic oscillation electrical signal generating circuit produces, after amplifying, front end luffing bar reaches the tool heads that is contained on the luffing bar, drive the abrasive suspension between tool heads and the workpiece, high speed impact, rubbing down reduce workpiece surface roughness and polish.Existing ultrasonic polishing machine does not have the automatic frequency tracking function mostly, make tool heads produce resonance, circuit Maximum Power Output, the output frequency of necessary manual adjustments supersonic oscillations electrical signal generating circuit, this exists two major defects at least: the one, because when workpiece polished, the frequency variation scope that the material of tool heads (copper, bamboo matter or wooden etc.) change causes is big, is not easy to find frequency optimum traffic; The 2nd, sound wave transmits through tool heads, can make tool heads, luffing bar, the transducer heating of polishing machine, add man-hour carrying out the pulse spark discharge, tool heads can shorten because of loss, these all can make the resonance of transducer change, the oscillating part of circuit also can Yin Wendu etc. influence make frequency produce drift, must frequent regulating circuit output frequency could operate as normal, operation is trouble quite.Though utilization phase-locking type automatic frequency tracking technology is also arranged in the prior art, but generally all take from the transducer two ends as voltage, the current phase signal of phase bit comparison, its shortcoming is to avoiding the interference of the pulse power in the ultrasonic polishing machine control circuit, must adopt isolated component isolation such as optocoupler pipe, cause distorted signals easily, make shaping circuit hand over complicatedly.

It is a kind of with transducer current signal and the pumping signal phase-locking type frequency-tracking ultrasonic polishing machine as comparison of signal phase that the purpose of this utility model is to provide in order to overcome above-mentioned defective of the prior art.

Principle of the present utility model is: PZT (piezoelectric transducer) is when series resonance, characteristic when similar LC series circuit resonance is arranged, equivalent resistance is very little, and be pure resistive, flow through the electric current maximum of transducer this moment, the difference of the phase place of electric current and the phase place of pumping signal is very responsive to the variation of driving frequency, utilize this characteristic that both phase difference detection are come out, and, make both phase differences be tending towards constant by control circuit adjustment driving frequency, just can reach the purpose of automatic frequency tracking;

Specific design scheme of the present utility model is: phase-locking type frequency-tracking ultrasonic polishing machine includes transducer on frame for movement, luffing bar and tool heads and main frame, transducer will convert ultrasonic wave to by the supersonic oscillations signal of telecommunication that the host computer control circuit provides, described supersonic oscillations electrical signal generating circuit comprises Voltage-Controlled oscillation circuit, frequency-halving circuit, power amplification circuit, match circuit and PZT (piezoelectric transducer), produce the square wave oscillation signal by Voltage-Controlled oscillation circuit, behind the frequency-halving circuit frequency division, divide two the tunnel to amplify through power amplification circuit respectively, and through the match circuit rear drive PZT (piezoelectric transducer) that unites two into one, it is characterized in that also including current sampling circuit and phase difference detecting circuit, current sampling circuit is obtained the current signal of transducer and is shaped to square wave by the primary coil that is serially connected in the current transformer on the described PZT (piezoelectric transducer), an input signal as phase difference detecting circuit, phase difference detecting circuit is mainly a NOR gate circuit, its another input directly connects one of them output of described frequency dividing circuit, its output is the voltage-controlled input of the described VCO generator of tieback then, thereby constitutes a phase-locking type frequency tracking circuit.

Compared with prior art, the utility model not only has the automatic frequency tracking function, and circuit structure is simple, reliable operation.

Description of drawings:

Fig. 1 is frame for movement of the present utility model (part) schematic diagram.

Fig. 2 is the functional-block diagram of transducer control circuit of the present utility model.

Fig. 3 is the schematic diagram of transducer control circuit of the present utility model.

Fig. 4 is phase difference detecting circuit input, an output waveform figure 7. in the transducer control circuit of the present utility model.

Embodiment describes in further detail the utility model below in conjunction with accompanying drawing.

As shown in Figure 1, phase-locking type frequency-tracking ultrasonic polishing machine includes transducer (1), luffing bar (2) and tool heads (3) and main frame (not showing in the accompanying drawing) on frame for movement, transducer (1) will convert ultrasonic wave to by the supersonic oscillations signal of telecommunication that the host computer control circuit provides;

As shown in Figure 2, described supersonic oscillations electrical signal generating circuit comprise Voltage-Controlled oscillation circuit 1., frequency-halving circuit 2., power amplification circuit 3., match circuit 4., PZT (piezoelectric transducer) 5., current sampling circuit 6. with phase difference detecting circuit 7.;

As shown in Figure 3, Voltage-Controlled oscillation circuit core parts IC1 1. is 555 timing integration blocks, be connected into voltage-controlled multivibrator form, frequency is by its peripheral resistance R 1, R2, capacitor C 2 and the decision of 5 pin current potentials, when hand switch K disconnects, 5 pin voltages are directly controlled by W1, and when hand switch K was closed, 5 pin voltages were controlled jointly by W1 and Uout; When 5 pin were 5V, frequency of oscillation was about 60KHz, and 2. the 3 pin outputs of IC1 output signal to frequency-halving circuit; Certainly Voltage-Controlled oscillation circuit also can be other form;

2. frequency-halving circuit adopts frequency division ic chip 2, can select 4013 for use, and output frequency is the positive and negative symmetrical square wave signal of 1/2 incoming frequency;

3. power amplification circuit comprises and amplifies the positive and negative half cycle two-way symmetry of the square wave amplifying circuit that 2. frequency-halving circuit export respectively, one routing resistance R5, driver triode T1, T2, resistance R 8, Zener diode D2 and FET T5 constitute, the resistance R 6 of another route symmetry, driver triode T3, T4, resistance R 7, Zener diode D3 and FET T6 constitute, the primary coil two ends of exporting tapping transformer B1 at last;

Match circuit 4. main element is transformer B1, be used for mating 5. HNQ and the power amplification circuit impedance between 3. of PZT (piezoelectric transducer), for 6. the current sampling circuit that cooperates the back better works, 5. and be connected to the series loop that constitutes by inductance L 1, capacitor C 4 between the secondary coil of transformer B1 be preferably in PZT (piezoelectric transducer), this loop resonance is in about 40KHz in the present embodiment, filter boost square-wave signal that coupling comes of transformer B1 sinusoidal wave, have boosting concurrently.

6. current sampling circuit is made of transformer B2, capacitor C 5 and triode T7, B2 is the current sample transformer, its primary coil L2 connects with PZT (piezoelectric transducer) HNQ, secondary coil L3 and capacitor C 5 constitute the shunt circuit, preferably adopt and to regulate magnetic-core type, to change the phase place of feedback signal, L3, C5 shunt circuit also have the effect of eliminating higher hamonic wave simultaneously, and the effect of triode T7 is a square wave that feedback signal is shaped to positive and negative symmetry as a phase difference detecting circuit input signal 7.;

7. phase difference detecting circuit is mainly an XOR gate IC3, can select 4070,4030 or 4046 for use, its another road comparison signal is directly provided by described frequency-halving circuit output (the Q end of IC2 or Q end) 2., its output is the described VCO generator of tieback voltage-controlled input 1. then---5 pin of IC1, and the output waveform of IC3 and input waveform relationship are as shown in Figure 4; When the phasic difference mutually of Uin2 and Uin1 during four/one-period, Uout is output as wide square wave, shown in Fig. 4 A;

Power supply EA is the 12V DC voltage among the figure.EB is 10～40V DC voltage, and A is tuning dial gauge.

The circuit working process is as follows: 1. produce the square wave oscillation signal by Voltage-Controlled oscillation circuit, 2. divide two the tunnel 3. to amplify through power amplification circuit respectively behind the frequency division through frequency-halving circuit, and 4. unite two into one and convert sine wave signal rear drive PZT (piezoelectric transducer) to 5. through match circuit, 6. current sampling circuit is obtained the current signal of transducer and is shaped to square wave by the primary coil L2 that is serially connected in the current transformer B 2 that 5. described PZT (piezoelectric transducer) go up, as a phase difference detecting circuit input signal 7., 7. by relatively itself and the 2. phase difference of output signal of frequency dividing circuit, described VCO generator voltage-controlled input signal is 1. controlled in output to phase difference detecting circuit; When voltage controlled oscillator driving frequency 1. is higher with respect to the resonant frequency of transducer, the transducer loop is perception, after the current hysteresis that 6. current sampling circuit is obtained, be that phase difference detecting circuit input signal Uin2 7. lags behind input signal Uin1, output high level width becomes big, shown in Fig. 4 B, voltage controlled oscillator voltage-controlled terminal voltage 1. raises, output frequency reduces thereby make, and forms complete automatic frequency tracking locked loop.

Claims

1. phase-locking type frequency-tracking ultrasonic polishing machine, frame for movement includes transducer (1), luffing bar (2) and tool heads (3) and main frame, transducer (1) will convert ultrasonic wave to by the supersonic oscillations signal of telecommunication that the host computer control circuit provides, described supersonic oscillations electrical signal generating circuit comprises that Voltage-Controlled oscillation circuit 1., frequency-halving circuit 2., power amplification circuit 3., match circuit 4., 1. produce the square wave oscillation signal by Voltage-Controlled oscillation circuit, 2. divide two the tunnel 3. to amplify through power amplification circuit respectively behind the frequency division through frequency-halving circuit, and 4. unite two into one through match circuit and to drive PZT (piezoelectric transducer) and 5. work, it is characterized in that also including current sampling circuit 6. with phase difference detecting circuit 7., 6. current sampling circuit is obtained the current signal of transducer and is shaped to square wave by the primary coil L2 that is serially connected in the current transformer B 2 that 5. described PZT (piezoelectric transducer) go up, as a phase difference detecting circuit input signal 7., 7. phase difference detecting circuit is mainly a NOR gate circuit, its another input directly connects described frequency dividing circuit one of them output 2., and its output is the described VCO generator of tieback voltage-controlled input 1. then.

2. phase-locking type frequency-tracking ultrasonic polishing machine as claimed in claim 1, it is characterized in that 6. described current sampling circuit is made of current sample transformer B2, capacitor C 5 and triode T7,5. the primary coil L2 of transformer B2 connects with PZT (piezoelectric transducer), and secondary coil L3 and capacitor C 5 constitute the shunt circuit.

3. phase-locking type frequency-tracking ultrasonic polishing machine as claimed in claim 2 is characterized in that described transformer B2 is for can regulate the magnetic-core type transformer.

4. phase-locking type frequency-tracking ultrasonic polishing machine as claimed in claim 1 is characterized in that being connected to the series loop that is made of inductance L 1, capacitor C 4 at the transformer B1 secondary coil and the PZT (piezoelectric transducer) of described match circuit in 4. between 5..

5. phase-locking type frequency-tracking ultrasonic polishing machine as claimed in claim 1 is characterized in that 1. described Voltage-Controlled oscillation circuit is connected into voltage-controlled resonant oscillator form by 555 timing integration block IC1 and peripheral resistance R 1 thereof, R2, capacitor C 2.