Ultrasonic power supply

Abstract

The present application discloses an ultrasonic power supply, comprising: a high-frequency inversion circuit for performing high-frequency inversion conversion on a received target current to obtain a high-frequency square wave signal serving as a power source for an ultrasonic transducer; a resonance determination circuit disposed between the high-frequency inversion circuit and the ultrasonic transducer, the resonance determination circuit being configured to determine whether the frequency of the high-frequency square wave signal provided to the ultrasonic transducer causes resonance deviation of the ultrasonic transducer; and a frequency control circuit disposed between the resonance determination circuit and the high-frequency inversion circuit, the frequency control circuit being configured to, when resonance deviation of the ultrasonic transducer occurs, control the high-frequency inversion module to adjust the frequency of the target current to a target frequency corresponding to a resonance state and then perform the high-frequency inversion conversion.

Description

Technical Field

[0001] This application relates to the field of ultrasonic technology, and in particular to an ultrasonic power supply. Background Art

[0002] Ultrasonic machining is a machining method that uses ultrasonic vibration to drive the workpiece and the abrasive suspension between the workpieces to impact and polish the machined part of the workpiece, so that the local material is eroded into powder for perforation, cutting, grinding, etc., and uses ultrasonic vibration to bond the workpieces together. The ultrasonic power supply is the power source for ultrasonic machining.

[0003] Currently, in order to reduce the energy loss of the ultrasonic machining system using the ultrasonic power supply, the ultrasonic power supply is manually tuned when it is idle to obtain the resonant state of the ultrasonic machining system under the no-load state. However, during the machining process, since the tip contacts the workpiece, the surface load will change, resulting in a change in the resonant frequency of the entire ultrasonic machining system, causing the tuning work performed when it is originally idle to fail, and the resonant shift will cause problems in machining and damage the tool. Summary of the Invention

[0004] The purpose of the embodiments of this application is to provide an ultrasonic power supply to solve the problem of resonant shift existing in the ultrasonic machining system during the machining process.

[0005] To solve the above technical problems, this specification is implemented as follows:

[0006] In a first aspect, an ultrasonic power supply is provided, including:

[0007] A high-frequency inverter circuit for performing high-frequency inverter conversion on the received target current to obtain a high-frequency square wave signal used as the power source for the ultrasonic transducer;

[0008] A resonance determination circuit is arranged between the high-frequency inverter circuit and the ultrasonic transducer. The resonance determination circuit is used to determine whether the frequency of the high-frequency square wave signal provided to the ultrasonic transducer causes resonance shift of the ultrasonic transducer;

[0009] A frequency control circuit is arranged between the resonance determination circuit and the high-frequency inverter circuit. The frequency control circuit is used to control the high-frequency inverter module to adjust the frequency of the target current to the target frequency corresponding to the resonance state and then perform the high-frequency inverter conversion when the ultrasonic transducer has resonance shift.

[0010] Optionally, the resonance determination circuit includes:

[0011] A sampling module is connected to the high-frequency inverter circuit and is used to collect voltage and current from the high-frequency square wave signal output by the high-frequency inverter circuit at a target moment;

[0012] A phase detection module, connected to the sampling module, for determining the phase difference between the voltage and current at the target moment;

[0013] A resonance determination module, connected to the phase detection module, for determining that the ultrasonic transducer has a resonance shift at the target moment when the phase difference is greater than a preset threshold.

[0014] Optionally, the frequency control circuit includes:

[0015] A signal generation module, connected to the resonance determination module, for generating a high-frequency pulse width modulation (PWM) signal of the target frequency according to the phase difference when the ultrasonic transducer has a resonance shift;

[0016] A signal output module, arranged between the signal generation module and the high-frequency inverter circuit, for outputting the PWM signal to the high-frequency inverter circuit;

[0017] Wherein, the high-frequency inverter module adjusts the frequency of the target current to the frequency of the PWM signal and then performs the high-frequency inverter conversion.

[0018] Optionally, the signal generation module generates a high-frequency pulse width modulation (PWM) signal of the target frequency according to the phase difference, specifically including:

[0019] The signal generation module determines a first frequency of the resonance state corresponding to the phase difference according to the range where the phase difference is located; and determines the first frequency as the target frequency.

[0020] Optionally, the target current is alternating current,

[0021] The ultrasonic power supply further includes: a waveform control circuit,

[0022] The waveform control circuit is arranged between the high-frequency inverter circuit and an external power supply, and is used for converting the target direct current output by the external power supply into the target current with variable frequency and amplitude according to the preset requirements of the ultrasonic processing surface.

[0023] Optionally, the waveform control circuit includes:

[0024] A waveform setting module, for setting a modulation wave with corresponding frequency, amplitude ratio and waveform shape according to the preset requirements;

[0025] A PWM signal module, for generating a PWM signal that changes with the period according to the modulation wave;

[0026] A waveform generation module, for generating the target current of the target waveform according to the PWM signal.

[0027] Optionally, the PWM signal module includes:

[0028] A first PWM signal unit, configured to generate a high-frequency modulation wave HPWM signal for controlling the amplitude of the target waveform according to the modulation wave;

[0029] A second PWM signal unit, configured to generate a low-frequency logic pulse width modulation LPWM signal for controlling the positive and negative cycle conversion of the target waveform according to the modulation wave;

[0030] Wherein, the waveform generation module generates a target current of the target waveform according to the high-frequency modulation wave HPWM signal and the low-frequency LPWM signal.

[0031] In a second aspect, an ultrasonic power supply is provided, including:

[0032] A waveform control circuit, connected to an external power supply, configured to convert the target direct current output by the external power supply into an alternating current with variable frequency and amplitude according to preset requirements of the ultrasonic processing surface;

[0033] A high-frequency inverter circuit, connected to the waveform control circuit, configured to perform high-frequency inverter conversion on the alternating current to obtain a high-frequency square wave signal used as the ultrasonic power supply and provide it to the ultrasonic transducer.

[0034] Optionally, the waveform control circuit includes:

[0035] A waveform setting module, configured to set a modulation wave with corresponding frequency, amplitude ratio, and waveform shape according to the preset requirements;

[0036] A PWM signal module, configured to generate a PWM signal that changes with the cycle according to the modulation wave;

[0037] A waveform generation module, configured to generate the alternating current of the target waveform according to the PWM signal.

[0038] Optionally, it further includes:

[0039] A resonance determination circuit, disposed between the high-frequency inverter circuit and the ultrasonic transducer, where the resonance determination circuit is configured to determine whether the frequency of the high-frequency square wave signal provided to the ultrasonic transducer causes resonance offset of the ultrasonic transducer;

[0040] A frequency control circuit, disposed between the resonance determination circuit and the high-frequency inverter circuit, where the frequency control circuit is configured to, in the case of resonance offset of the ultrasonic transducer, control the high-frequency inverter module to adjust the frequency of the target current to the target frequency corresponding to the resonance state and then perform the high-frequency inverter conversion.

[0041] In the embodiment of the present application, the high-frequency inverter circuit included in the ultrasonic power supply is used to perform high-frequency inverter conversion on the received target current to obtain a high-frequency square wave signal used as a power source for the ultrasonic transducer; a resonance determination circuit is arranged between the high-frequency inverter circuit and the ultrasonic transducer, and the resonance determination circuit is used to determine whether the frequency of the high-frequency square wave signal provided to the ultrasonic transducer causes the ultrasonic transducer to have a resonance shift; a frequency control circuit is arranged between the resonance determination circuit and the high-frequency inverter circuit, and the frequency control circuit is used to control the high-frequency inverter module to adjust the frequency of the target current to the target frequency corresponding to the resonance state and then perform the high-frequency inverter conversion when the ultrasonic transducer has a resonance shift, thereby controlling the waveform frequency flowing into the ultrasonic transducer in real time, forming a closed-loop control, realizing automatic tracking and adjustment of the frequency, and in the process of machining variable loads, the resonance state can be automatically adjusted to reduce system energy loss, obtain maximum energy utilization, reduce heat generation, extend tool life, and improve machining effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0043] Figure 1 It is a structural block diagram of the ultrasonic power supply of the first embodiment of the present application.

[0044] Figure 2 It is a block diagram of the specific structure of each circuit of the ultrasonic power supply of an embodiment of the present application.

[0045] Figure 3 It is a schematic diagram of the frequency adjustment process of an embodiment of the present application.

[0046] Figure 4 It is a specific structural block diagram of the waveform control circuit of an embodiment of the present application.

[0047] Figure 5 It is a structural block diagram of the ultrasonic power supply of the second embodiment of the present application. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application. The numbering of the drawings in this application is only used to distinguish the various steps in the scheme, and is not used to limit the execution order of the various steps. The specific execution order is subject to the description in the specification.

[0049] In order to solve the problems existing in the prior art, in one embodiment, the embodiment of the present application provides an ultrasonic power supply, including: a high-frequency inverter circuit, configured to perform high-frequency inverter conversion on the received target current to obtain a high-frequency square wave signal used as a power source for an ultrasonic transducer; a resonance determination circuit, disposed between the high-frequency inverter circuit and the ultrasonic transducer, the resonance determination circuit being configured to determine whether the frequency of the high-frequency square wave signal provided to the ultrasonic transducer causes a resonance shift of the ultrasonic transducer; a frequency control circuit, disposed between the resonance determination circuit and the high-frequency inverter circuit, the frequency control circuit being configured to, when the ultrasonic transducer has a resonance shift, control the high-frequency inverter module to adjust the frequency of the target current to the target frequency corresponding to the resonance state and then perform the high-frequency inverter conversion.

[0050] Figure 1 is a structural block diagram of the ultrasonic power supply according to the first embodiment of the present application. As Figure 1 shown, the ultrasonic power supply 100 includes a high-frequency inverter circuit 120, a resonance determination circuit 140, and a frequency control circuit 160.

[0051] The high-frequency inverter circuit 120 can receive a current input of direct current (DC) or alternating current (AC). The DC input can be provided by an external power supply, such as a mains input or any DC power supply input after rectification and filtering; the AC input can be an input obtained by subjecting the DC input to target processing, which will be described later. That is to say, the ultrasonic power supply of the present application can be compatible with AC input and DC input.

[0052] The target current input is a low-frequency current signal or a DC signal. The high-frequency inverter circuit 120 is configured to perform high-frequency inverter conversion on the received low-frequency current signal to obtain a high-frequency square wave signal applicable to an ultrasonic processing system. The resonance determination circuit 140 is disposed between the high-frequency inverter circuit 120 and an ultrasonic transducer (not shown in the figure). The ultrasonic transducer is a part of the ultrasonic processing system. The high-frequency square wave signal output by the high-frequency inverter circuit 120 is finally input to the ultrasonic transducer to realize the conversion from electrical energy to mechanical energy, so as to realize that the ultrasonic power supply provides a power source for the ultrasonic processing system.

[0053] The resonance determination circuit 140 is disposed before the ultrasonic transducer to track the frequency of the high-frequency square wave signal input from the high-frequency inverter circuit 120 to the ultrasonic transducer, so as to determine whether this frequency will cause a resonance shift of the ultrasonic transducer or the ultrasonic processing system.

[0054] The frequency control circuit 160 is arranged between the resonance determination circuit 140 and the high-frequency inverter circuit 120. The frequency control circuit 160 receives the judgment result output by the resonance determination circuit 140, that is, whether the ultrasonic transducer has a resonance shift. In the case where the ultrasonic transducer has a resonance shift, the frequency control circuit 160 outputs a control signal to the high-frequency inverter circuit 120 to control the high-frequency inverter module 120 to adjust the frequency of the currently received target current to the frequency corresponding to the resonance state, that is, the frequency for correcting the resonance shift, and then performs high-frequency inverter conversion on the current after frequency adjustment to obtain a corresponding high-frequency square wave signal, which is then input into the ultrasonic transducer to provide a power source.

[0055] Of course, at this time, the resonance determination circuit and the frequency control circuit also continue to work, and in the process of ultrasonic processing, they continuously track and monitor the frequency of the high-frequency square wave signal input from the high-frequency inverter circuit 120 to the ultrasonic transducer, so as to perform frequency adjustment and control when the ultrasonic transducer has a resonance shift, thereby achieving automatic adjustment of the resonance state when the ultrasonic processing system is no-load or working.

[0056] Based on the solution provided in the above embodiment, optionally, the resonance determination circuit 140 includes: a sampling module, connected to the high-frequency inverter circuit, for collecting voltage and current from the high-frequency square wave signal output by the high-frequency inverter circuit at a target moment; a phase detection module, connected to the sampling module, for determining the phase difference between the voltage and current at the target moment; a resonance determination module, connected to the phase detection module, for determining that the ultrasonic transducer has a resonance shift at the target moment when the phase difference is greater than a preset threshold.

[0057] In this embodiment, the resonance determination circuit 140 determines whether the ultrasonic transducer has a resonance shift at a corresponding moment through the voltage and current phases corresponding to the high-frequency square wave signals at each moment.

[0058] Next, in combination with Figure 2 the following embodiment, the working principle of the resonance determination circuit 140 will be described in detail.

[0059] As Figure 2 shown, the high-frequency inverter circuit 120 may include a high-frequency inverter module and an isolation drive module. Through the high-frequency inverter module, a high-frequency square wave signal with a peak value at least twice the amplitude of the target current is generated, and through the isolation drive module, such as a high-frequency transformer, isolation of the high-frequency square wave signal and the power ground is achieved, avoiding direct grounding of one end of the ultrasonic transducer, resulting in heating and burning.

[0060] The sampling module can correspond to Figure 2The sampling and matching module, connected to the high-frequency inverter circuit, can integrate the sampling function and the impedance matching function together. The sampling and matching module is used to collect voltage and current from the high-frequency square wave signal output by the high-frequency inverter circuit and perform impedance matching before the high-frequency square wave signal is input to the ultrasonic transducer to improve the energy utilization rate.

[0061] In the sampling and matching module, the sampling module samples the high-frequency square wave signal to obtain a corresponding pair of voltage square wave signal and current sine signal. Before the phase detection module detects the 0 phase difference between the pair of voltage and current, it can first pass through the signal amplification module to amplify the sampled signal by an appropriate multiple, and then use an active filter to filter out the harmonics carried by the two signals to obtain a pure waveform signal, which is beneficial to subsequent signal processing. The voltage and current signals continue to pass through the zero-crossing comparison module to obtain two square wave signals with a predetermined amplitude. The phase detection circuit detects the two square wave signals to obtain the phase difference pulse width signal of the voltage leading the current, or the phase difference pulse width signal of the current leading the voltage. That is, the phase difference between the voltage and current of the high-frequency square wave signal output by the high-frequency inverter circuit 120 at the current moment is determined.

[0062] After obtaining the phase difference, if the phase difference is greater than the preset threshold, it is determined that the ultrasonic transducer will have a resonance offset after the high-frequency square wave signal is input to the ultrasonic transducer at the target moment. Further, the frequency of the high-frequency square wave signal output by the high-frequency inverter circuit 120 needs to be controlled according to the phase difference.

[0063] Based on the solution provided in the above embodiment, optionally, the frequency control circuit 160 includes: a signal generation module, connected to the resonance determination module, for generating a high-frequency pulse width modulation (PWM) signal with the target frequency according to the phase difference in the case of resonance offset of the ultrasonic transducer; a signal output module, arranged between the signal generation module and the high-frequency inverter circuit, for outputting the PWM signal to the high-frequency inverter circuit; wherein, the high-frequency inverter module adjusts the frequency of the target current to the frequency of the PWM signal and then performs the high-frequency inverter conversion.

[0064] The signal generation module can correspond to a programmable logic array (Field Programmable Gate Array, FPGA). By entering the FPGA for calculation, a high-frequency pulse width modulation (PWM) signal with the target frequency is obtained. The determination method of the frequency of the high-frequency PWM signal can be as shown in the flowchart of

[0065] 5 The signal generation module can correspond Figure 2 to the programmable logic array (Field Programmable Gate Array, FPGA). By entering the FPGA for calculation, a high-frequency pulse width modulation (PWM) signal with the target frequency is obtained. The determination method of the frequency of the high-frequency PWM signal can be as shown in the flowchart of Figure 3 as shown in the flowchart.

[0066] Step 1002, the FPGA initially sets the initial frequency word of the PWM signal to fre_data. For example, the system resonance frequency is 30KHz.

[0067] If the resonance determination circuit determines that the ultrasonic transducer system is not in the resonance state, there will be a situation where the voltage or current phase is ahead.

[0068] Step 1004, determine whether the voltage is ahead of the current by pulse width counting, that is, determine whether the count of voltage ahead of current VoverI_cnt_reg is greater than 0 and the count of current ahead of voltage IoverV_cnt_reg is equal to 0. If both are satisfied, it means the phase of the voltage ahead of the current, then enter Step 1008; otherwise, enter Step 1006.

[0069] Step 1006, determine whether the current is ahead of the voltage by pulse width counting, that is, determine whether the count of current ahead of voltage IoverV_cnt_reg is greater than 0 and the count of current ahead of current VoverI_cnt_reg is equal to 0. If both are satisfied, it means the phase of the current ahead of the voltage, then enter Step 1008; otherwise, enter Step 1020.

[0070] The existence of a phase lead in the current or voltage indicates that there is a resonance offset in the current ultrasonic transducer. Then, the FPGA needs to adjust the initial frequency word to generate a PWM signal with an adjusted frequency, which is used to control the frequency value of the target current input received by the high-frequency inverter circuit, thereby changing the frequency of the high-frequency square wave signal input from the high-frequency inverter circuit to the ultrasonic transducer.

[0071] Optionally, the signal generation module generates a high-frequency pulse width modulation (PWM) signal with a target frequency according to the phase difference, specifically including: the signal generation module determines a first frequency of the resonance state corresponding to the phase difference according to the range where the phase difference is located; and determines the first frequency as the target frequency.

[0072] Step 1008, determine whether the count of voltage ahead of current VoverI_cnt_reg or the count of current ahead of voltage IoverV_cnt_reg is less than a preset threshold α. If so, enter Step 1012; otherwise, enter Step 1010;

[0073] Step 1010, determine whether the count of voltage ahead of current VoverI_cnt_reg or the count of current ahead of voltage IoverV_cnt_reg is less than a preset threshold β. If so, enter Step 1016.

[0074] The threshold α is less than the threshold β. If the corresponding count value is less than the threshold α, it indicates that the phase difference is small; if the count value is not less than the threshold α and less than the threshold β, it indicates that the phase difference is large. According to the pulse width of the voltage or current leading, the count is compared with different thresholds, and the initial frequency word is adjusted with a variable step size. The larger the phase difference, the larger the adjustment step size.

[0075] Step 1012, for the voltage leading the current, the step size tracking of the corresponding adjusted frequency is the initial frequency word fre_data plus a preset value, such as 1 / 16 of the count VoverI_cnt_reg of the voltage leading the current, that is, fre_data + VoverI_cnt_reg / 16.

[0076] Step 1014, for the voltage lagging behind the current, that is, the current leading the voltage, the step size tracking of the corresponding adjusted frequency is the initial frequency word fre_data minus a preset value, such as 1 / 16 of the count IoverV_cnt_reg of the current leading the voltage, that is, fre_data - IoverV_cnt_reg_reg / 16.

[0077] Step 1016, for the voltage leading the current, the step size tracking of the corresponding adjusted frequency is the frequency word fre_data plus a preset value, such as 1 / 8 of the count VoverI_cnt_reg of the voltage leading the current.

[0078] Step 1018, for the voltage lagging behind the current, that is, the current leading the voltage, the step size tracking of the corresponding adjusted frequency is the initial frequency word fre_data minus a preset value, such as 1 / 8 of the count IoverV_cnt_reg of the current leading the voltage.

[0079] Through the above steps 1012, 1014, 1016 or 1018, when the phase difference between the voltage and the current is large, the feedback degree is adjusted greatly, and when the phase difference between the voltage and the current is small, the feedback degree is adjusted with a corresponding gradient decrease. The adjusted frequency value obtained by the above steps is used to update the initial frequency word fre_data and save it for generating the PWM signal. When there is a subsequent frequency adjustment, the saved frequency word fre_data is updated.

[0080] Step 1020, it is judged whether the ultrasonic transducer is in the resonant state by judging whether the phases of the current and the voltage are the same through pulse width counting, that is, judging whether the count IoverV_cnt_reg of the current leading the voltage is equal to 0 and whether the count VoverI_cnt_reg of the current leading the current is equal to 0. If both are satisfied, it means it is in the resonant state, and then step 1022 is entered.

[0081] Step 1022: Obtain the value of the current frequency word fre_data as the frequency of the generated PWM signal.

[0082] Step 1024: Output the PWM signal.

[0083] The signal generation module provides the generated PWM signal to the IO port of the FPGA for output, and provides it to the subsequent signal output module hardware circuit to control the resonant state of the system.

[0084] In one embodiment, the signal output module corresponds to, for example, Figure 2 the waveform inversion module, dead-time formation module, and gate drive module. Closed-loop control is achieved through waveform inversion, dead-time formation, and gate drive to drive the switching tubes in the high-frequency inverter module. The high-frequency inverter module adjusts the frequency of the currently received target current to the frequency of the PWM signal and then performs high-frequency inverter conversion.

[0085] Thus, automatic tracking and adjustment of the frequency can be achieved when there is a resonant shift under load changes, enabling the ultrasonic machining system to operate in a resonant state. This can reduce the energy loss of the system, obtain the maximum energy utilization rate, and can reduce heat generation and extend the tool life.

[0086] In addition, traditional ultrasonic power supplies can only adjust the amplitude before processing to meet constant amplitude control. During processing, they can only maintain a fixed amplitude for processing and cannot meet the requirements of some specific processing surfaces.

[0087] Optionally, in one embodiment, the target current is an alternating current, and the ultrasonic power supply further includes: a waveform control circuit. The waveform control circuit is arranged between the high-frequency inverter circuit and the external power supply and is used to convert the target direct current output by the external power supply into the target current with variable frequency and amplitude according to the preset requirements of the ultrasonic processing surface.

[0088] In this embodiment, an AC current with variable frequency and amplitude can be provided by the waveform control circuit during processing according to the requirements of the specific processing surface.

[0089] As Figure 2 shown, when the AC input received by the high-frequency inverter circuit 120 is an AC input, this AC input can be the input after converting the target direct current output by the external power supply according to the preset requirements of the ultrasonic processing surface. Here, the AC input is the target current with variable frequency and amplitude.

[0090] Optionally, the waveform control circuit includes: a waveform setting module for setting a modulation wave with corresponding frequency, amplitude ratio, and waveform shape according to the preset requirements; a PWM signal module for generating a PWM signal that changes with the period according to the modulation wave; and a waveform generating module for generating the target current of the target waveform according to the PWM signal.

[0091] Optionally, the PWM signal module includes: a first PWM signal unit for generating a high-frequency modulation wave HPWM signal for controlling the amplitude of the target waveform according to the modulation wave; and a second PWM signal unit for generating a low-frequency logic pulse

[0092] width modulation LPWM signal according to the modulation wave; wherein, the waveform generating module generates the target current of the target waveform according to the high-frequency modulation wave HPWM5 signal and the low-frequency LPWM signal.

[0093] Reference Figure 4 , Figure 4 is to generate an alternating current with controllable frequency and amplitude for sine envelope processing according to specific requirements, and then provide it to the high-frequency inverter circuit 120.

[0094] Specifically, as Figure 4 shown, set various waveform parameters corresponding to the sine envelope processing requirements in MATLAB, including frequency, amplitude, and waveform shape, etc. as the modulation wave, and then use a triangular carrier wave that is several hundred or several thousand times higher than the 0 frequency of the modulation wave, set an appropriate modulation ratio, and differentiate the modulation wave.

[0095] And obtain the coordinates of several sampling points within a single period of the two groups of waveforms, and store them as the modulation wave COE file and the carrier COE file respectively. Use a comparator to compare the data of each point in the two files to obtain a PWM pulse width data table that changes with the period, including a high-frequency sine wave pulse width modulation (SPWM) data table and a low-frequency logic wave pulse width modulation (LPWM) data table.

[0096] 5 Call the above SPWM data table and LPWM data table through the FPGA, respectively output a high-frequency SPWM signal for controlling the amplitude and a low-frequency LPWM signal for controlling the positive and negative period conversion, and use a waveform inversion circuit composed of a dead zone forming circuit and an inverting buffer to obtain two high-frequency SPWM waves and low-frequency LPWM waves with the same frequency, opposite phases, and dead zones. The two signals are respectively input into the corresponding gate drives

[0097] The circuit, namely the high-frequency arm drive circuit and the low-frequency arm drive circuit, isolates and drives the switch 0 tube in the sine generation module, thereby generating a corresponding sine wave, that is, an alternating current with controllable frequency and amplitude, and inputting it into the high-frequency inverter circuit 120 to obtain a high-frequency alternating current, and then obtaining the required waveform through rectification and filtering to meet the requirements of specific machining surfaces.

[0098] Thus, during ultrasonic machining, it is possible to differentiate the waveform of the DC input voltage and use an algorithm to output a PWM wave with a variable duty cycle, thereby realizing the output of voltages with various waveforms and meeting the requirements of special machining surfaces.

[0099] For different transducers, the ultrasonic power supply according to the embodiments of the present application can achieve automatic adjustment of the resonant state and control of the variable amplitudes of various waveforms.

[0100] In the embodiments of the present application, the high-frequency inverter circuit included in the ultrasonic power supply is used to perform high-frequency inverter conversion on the received target current to obtain a high-frequency square wave signal used as the ultrasonic power supply; the resonance determination circuit is arranged between the high-frequency inverter circuit and the ultrasonic transducer, and the resonance determination circuit is used to determine whether the frequency of the high-frequency square wave signal provided to the ultrasonic transducer causes resonance deviation of the ultrasonic transducer; the frequency control circuit is arranged between the resonance determination circuit and the high-frequency inverter circuit, and the frequency control circuit is used to control the high-frequency inverter module to adjust the frequency of the target current to the target frequency corresponding to the resonant state and then perform the high-frequency inverter conversion in the case of resonance deviation of the ultrasonic transducer, thereby real-time controlling the waveform frequency flowing into the ultrasonic transducer, forming a closed-loop control, realizing automatic tracking and adjustment of the frequency, and being able to automatically adjust the resonant state during the machining variable load process, reducing the system energy loss, obtaining the maximum energy utilization rate, and being able to reduce heating and extend the tool life, improving the machining effect.

[0101] In another embodiment, the present application also proposes an ultrasonic power supply. Figure 5 It is the structural block diagram of the ultrasonic power supply according to the second embodiment of the present application.

[0102] As Figure 5 shown, the ultrasonic power supply 200 includes:

[0103] The waveform control circuit 230 is connected to an external power supply and is used to convert the target direct current output by the external power supply into an alternating current with variable frequency and amplitude according to the preset requirements of the ultrasonic machining surface.

[0104] The high-frequency inverter circuit 220 is connected to the waveform control circuit and is used to perform high-frequency inverter conversion on the alternating current to obtain a high-frequency square wave signal used as the ultrasonic power supply and provide it to the ultrasonic transducer.

[0105] Optionally, the waveform control circuit includes:

[0106] A waveform setting module for setting a modulation wave with a corresponding frequency, amplitude ratio, and waveform shape according to the preset requirements;

[0107] A PWM signal module for generating a PWM signal that changes with the period according to the modulation wave;

[0108] A waveform generation module for generating the alternating current of the target waveform according to the PWM signal.

[0109] The waveform control circuit 230 provided by the embodiments of the present application can implement Figure 3 each process implemented by the waveform control circuit 130 of the embodiment. To avoid repetition, it will not be elaborated here.

[0110] Optionally, the ultrasonic power supply 200 further includes:

[0111] A resonance determination circuit provided between the high-frequency inverter circuit and the ultrasonic transducer, and the resonance determination circuit is used to determine whether the frequency of the high-frequency square wave signal provided to the ultrasonic transducer causes resonance deviation of the ultrasonic transducer;

[0112] A frequency control circuit provided between the resonance determination circuit and the high-frequency inverter circuit, and the frequency control circuit is used to control the high-frequency inverter module to adjust the frequency of the target current to the target frequency corresponding to the resonance state and then perform the high-frequency inverter conversion in the case of resonance deviation of the ultrasonic transducer.

[0113] The resonance determination circuit provided by the embodiments of the present application can implement Figures 1 to 3 each process implemented by the resonance determination circuit 140 of the embodiment. The frequency control circuit provided by the embodiments of the present application can implement Figures 1 to 3 each process implemented by the frequency control circuit 160 of the embodiment. To avoid repetition, it will not be elaborated here.

[0114] In the embodiments of the present application, through the waveform control circuit included in the ultrasonic power supply, which is connected to an external power supply and is used to convert the target direct current output by the external power supply into an alternating current with variable frequency and amplitude according to the preset requirements of the ultrasonic processing surface; a high-frequency inverter circuit, connected to the waveform control circuit, for performing high-frequency inverter conversion on the alternating current to obtain a high-frequency square wave signal used as the ultrasonic power supply and providing it to the ultrasonic transducer, thereby being able to control the waveform input to the ultrasonic transducer to have a variable amplitude, realizing voltage output of multiple waveforms, and meeting the requirements of special processing surfaces.

[0115] It should be noted that in this text, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the presence of additional identical elements in the process, method, article or device including that element.

[0116] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present application.

[0117] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them fall within the protection scope of the present application.

Claims

1. An ultrasonic power supply, characterized in that, it includes: A high-frequency inverter circuit for performing high-frequency inverter conversion on the received target current to obtain a high-frequency square wave signal used as the power source of the ultrasonic transducer; A resonance determination circuit arranged between the high-frequency inverter circuit and the ultrasonic transducer, and the resonance determination circuit is used to determine whether the frequency of the high-frequency square wave signal provided to the ultrasonic transducer causes resonance deviation of the ultrasonic transducer; A frequency control circuit arranged between the resonance determination circuit and the high-frequency inverter circuit, and the frequency control circuit is used to control the high-frequency inverter module to adjust the frequency of the target current to the target frequency corresponding to the resonance state and then perform the high-frequency inverter conversion when the ultrasonic transducer has resonance deviation; Wherein the resonance determination circuit includes: a sampling module connected to the high-frequency inverter circuit for collecting voltage and current from the high-frequency square wave signal output by the high-frequency inverter circuit at a target moment, a phase detection module connected to the sampling module for determining the phase difference between the voltage and current at the target moment; a resonance determination module connected to the phase detection module for determining that the ultrasonic transducer has resonance deviation at the target moment when the phase difference is greater than a preset threshold; The frequency control circuit includes: a signal generation module connected to the resonance determination module for generating a high-frequency pulse width modulation PWM signal of the target frequency according to the phase difference when the ultrasonic transducer has resonance deviation; a signal output module arranged between the signal generation module and the high-frequency inverter circuit for outputting the PWM signal to the high-frequency inverter circuit; wherein, the high-frequency inverter module adjusts the frequency of the target current to the frequency of the PWM signal and then performs the high-frequency inverter conversion; The signal generation module generates a high-frequency pulse width modulation PWM signal of the target frequency according to the phase difference, specifically including: the signal generation module determines the first frequency of the resonance state corresponding to the phase difference according to the range where the phase difference is located; and determines the first frequency as the target frequency.

2. The ultrasonic power supply according to claim 1, characterized in that, the target current is alternating current, the ultrasonic power supply further includes: a waveform control circuit, The waveform control circuit is arranged between the high-frequency inverter circuit and an external power supply, and is used to convert the target direct current output by the external power supply into the target current with variable frequency and amplitude according to the preset requirements of the ultrasonic processing surface.

3. The ultrasonic power supply according to claim 2, characterized in that, the waveform control circuit includes: A waveform setting module for setting a modulation wave with corresponding frequency, amplitude ratio and waveform shape according to the preset requirements; A PWM signal module for generating a PWM signal that changes with the period according to the modulation wave; A waveform generation module for generating the target current of the target waveform according to the PWM signal.

4. The ultrasonic power supply according to claim 3, characterized in that, The PWM signal module includes: The first PWM signal unit is configured to generate a high-frequency modulation wave HPWM signal for controlling the amplitude of the target waveform according to the modulation wave; The second PWM signal unit is configured to generate a low-frequency logic pulse width modulation LPWM signal for controlling the positive and negative cycle conversion of the target waveform according to the modulation wave; Wherein, the waveform generation module generates a target current of the target waveform according to the high-frequency modulation wave HPWM signal and the low-frequency LPWM signal.

5. An ultrasonic power supply, characterized in that, it includes: A waveform control circuit, connected to an external power supply, is configured to convert the target direct current output by the external power supply into an alternating current with variable frequency and amplitude according to the preset requirements of the ultrasonic processing surface; A high-frequency inverter circuit, connected to the waveform control circuit, is configured to perform high-frequency inverter conversion on the alternating current to obtain a high-frequency square wave signal used as the ultrasonic power supply and provide it to the ultrasonic transducer; A resonance determination circuit, arranged between the high-frequency inverter circuit and the ultrasonic transducer, is configured to determine whether the frequency of the high-frequency square wave signal provided to the ultrasonic transducer causes resonance offset of the ultrasonic transducer; A frequency control circuit, arranged between the resonance determination circuit and the high-frequency inverter circuit, is configured to control the high-frequency inverter module to adjust the frequency of the alternating current to the target frequency corresponding to the resonance state and then perform the high-frequency inverter conversion when the ultrasonic transducer has resonance offset; Wherein the resonance determination circuit includes: a sampling module, connected to the high-frequency inverter circuit, is configured to collect voltage and current from the high-frequency square wave signal output by the high-frequency inverter circuit at a target moment; a phase detection module, connected to the sampling module, is configured to determine the phase difference between the voltage and current at the target moment; a resonance determination module, connected to the phase detection module, is configured to determine that the ultrasonic transducer has resonance offset at the target moment when the phase difference is greater than a preset threshold; The frequency control circuit includes: a signal generation module, connected to the resonance determination module, is configured to generate a high-frequency pulse width modulation PWM signal of the target frequency according to the phase difference when the ultrasonic transducer has resonance offset; a signal output module, arranged between the signal generation module and the high-frequency inverter circuit, is configured to output the PWM signal to the high-frequency inverter circuit; wherein, the high-frequency inverter module adjusts the frequency of the alternating current to the frequency of the PWM signal and then performs the high-frequency inverter conversion; The signal generation module generates a high-frequency pulse width modulation PWM signal of the target frequency according to the phase difference, specifically including: the signal generation module determines a first frequency of the resonance state corresponding to the phase difference according to the range where the phase difference is located; and determines the first frequency as the target frequency.

6. The ultrasonic power supply according to claim 5, characterized in that, the waveform control circuit includes: A waveform setting module, configured to set a modulation wave with corresponding frequency, amplitude ratio and waveform shape according to the preset requirements; A PWM signal module for generating a PWM signal that varies with a period according to the modulation wave; A waveform generation module for generating the alternating current of the target waveform according to the PWM signal.

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