CN112720790A - High-precision press system for ceramic preparation based on piezoelectric structure - Google Patents
High-precision press system for ceramic preparation based on piezoelectric structure Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28B3/00—Producing shaped articles from the material by using presses; Presses specially adapted therefor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28B17/00—Details of, or accessories for, apparatus for shaping the material; Auxiliary measures taken in connection with such shaping
- B28B17/0063—Control arrangements
- B28B17/0081—Process control
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
- H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
- H02N2/02—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing linear motion, e.g. actuators; Linear positioners ; Linear motors
- H02N2/06—Drive circuits; Control arrangements or methods
- H02N2/062—Small signal circuits; Means for controlling position or derived quantities, e.g. for removing hysteresis
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Abstract
The invention discloses a high-precision press system for ceramic preparation based on a piezoelectric structure, which comprises a press mechanism and a drive control circuit, wherein the press mechanism comprises a press mechanism body and a piezoelectric stack, the piezoelectric stack is arranged on the press mechanism body and used for providing a pressure source for the press system, and the press mechanism body acts the pressure generated by the deformation of the piezoelectric stack on an applied mechanism through an auxiliary mechanism; the driving control circuit utilizes the SPWM duty cycle to adjust the voltage applied to the piezoelectric stack, further controls the displacement of the piezoelectric stack, realizes the conversion of the voltage into the deformation displacement of the piezoelectric stack, and simultaneously, the pressure generated by the deformation of the piezoelectric stack is applied to the ceramic. The piezoelectric stack is driven by the unipolar single-side stepped SPWM circuit, the equivalent voltage amplitude applied to the piezoelectric stack is changed by adjusting the SPWM wave duty ratio, the hysteresis problem of the piezoelectric stack can be effectively solved, and the piezoelectric stack has high reliability and precision and high efficiency.
Description
Technical Field
The invention relates to a high-precision pressing device of ceramic preparation processing equipment, in particular to a high-precision pressing system for ceramic preparation based on a piezoelectric structure.
Background
Modern technical ceramics are high-performance materials manufactured by strict composition and production process control according to required product performance, and are one of the most active fields of new material technology development. Modern technical ceramics comprise three main areas: structural ceramics, ceramic matrix composites and functional ceramics. Compared with common metal materials, the structural ceramic has excellent high-temperature mechanical properties, chemical corrosion resistance, high-temperature oxidation resistance and small abrasion-resistant specific gravity, and has gradually replaced ultrahigh alloy steel to be applied to occasions where the metal materials cannot be used; the ceramic-based composite material improves the toughness of the ceramic and is widely applied to ceramic cutting tools; the functional ceramic has physical properties of light, heat, electricity and the like, and has wide application prospects in high and new fields of laser technology, ultrasonic technology, semiconductor industry and the like.
The modern ceramic has high processing precision requirement and long manufacturing process, and the basic preparation process mainly comprises a plurality of steps of dry pressing, sintering, CNC, debugging, installing and the like. The dry pressing molding is to put the granulated powder into a mold and a machine, apply pressure through a pressure head, the pressure head moves in a mold cavity, transmit the pressure, and enable the powder particles in the mold cavity to be rearranged and deformed and to be compacted, so as to form a ceramic biscuit with certain strength and shape. The influencing factors mainly comprise powder properties, selection of a binder and a lubricant, mold design, pressing force in the pressing process, a pressing mode, acceleration, pressure maintaining time and the like. The compactness of the ceramic biscuit influences the performance of the ceramic, so the selection of the parameters of pressure and dwell time of dry pressing is critical.
The traditional press structure mostly adopts mechanical structures such as hydraulic pressure and the like, and provides pressing acting force through the coordination of various machines. Because the technical bottleneck of the traditional machine exists, the self precision of the mechanical press structure is difficult to be greatly improved, and the pressing acting force error can be gradually accumulated to influence the service life of the mechanism along with the problems of structural abrasion and the like caused by long-time use. In addition, the traditional mechanical press cannot be directly molded after one-time pressing due to low pressure control precision, and also needs post-treatment processes such as grinding and the like, so that the processing cost is high, and the processing period is long. The piezoelectric stack structure is adopted to replace the traditional mechanical structure, so that the problems can be effectively solved.
The piezoelectric stack is usually formed by laminating a plurality of piezoelectric ceramic wafers and electrodes and performing a certain processing process. Generally, a displacement difference exists between a voltage-increasing curve and a voltage-reducing curve of the piezoelectric ceramic, and under the action of the same voltage value, the displacement amplitudes of the voltage-increasing curve and the voltage-reducing curve are obviously different, which is called as a hysteresis effect. The piezoelectric stack further aggravates the hysteresis between the output displacement of the piezoelectric ceramic wafer and the driving voltage, thereby affecting the dynamic output performance of the press.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide a ceramic high-precision press system based on a piezoelectric structure, which utilizes the advantages of high precision and high reliability of piezoelectric materials, applies voltage to a piezoelectric ceramic stack to enable a mechanism to generate deformation output acting force, and utilizes a press device of the piezoelectric stack to realize micron-scale deformation control so as to meet the requirement of a pressing process.
The technical scheme is as follows: the high-precision press system for ceramic preparation based on the piezoelectric structure comprises a press mechanism and a driving control circuit, wherein the press mechanism comprises a press mechanism body and a piezoelectric stack, the piezoelectric stack is arranged on the press mechanism body and used for providing a pressure source for the press system, and the press mechanism body acts the pressure generated by the deformation of the piezoelectric stack on an applied mechanism through an auxiliary mechanism; the driving control circuit utilizes the SPWM duty cycle to adjust the voltage applied to the piezoelectric stack, further controls the displacement of the piezoelectric stack, realizes the conversion of the voltage into the deformation displacement of the piezoelectric stack, and simultaneously, the pressure generated by the deformation of the piezoelectric stack is applied to the ceramic.
Preferably, the pressing machine mechanism body is of a cylindrical ceramic structure, a concentric circular groove is formed in the center of the bottom of the pressing machine mechanism body, the thickness of the bottom of the concentric circular groove is 0.5mm to 2mm, the position acts on the position of the applied mechanism through an auxiliary mechanism, a central through hole is formed in the center of the concentric circular groove, a plurality of piezoelectric stacking grooves are uniformly formed in the periphery of the concentric circular groove, the piezoelectric stacking grooves are respectively used for installing a plurality of corresponding piezoelectric stacks, wire grooves are formed between the side walls of the adjacent piezoelectric stacking grooves, a gathering wire groove is formed in the outer side wall of one of the piezoelectric stacking grooves, the gathering wire groove penetrates through the pressing machine mechanism body, and power supply wires of all the piezoelectric stacks are uniformly connected to a driving.
Preferably, the bottom of the concentric circular groove is also provided with an inner ring arc groove and an outer ring arc groove, and the top of the pressing machine mechanism body is also provided with a top arc groove corresponding to the inner ring arc groove and the outer ring arc groove respectively, so as to reduce stress concentration in the pressing machine mechanism.
Preferably, the press mechanism body is provided with a mounting hole between every two adjacent piezoelectric stacking grooves on the periphery of the piezoelectric stacking grooves.
Preferably, the shape and the number of the piezoelectric stacks are matched with those of the piezoelectric stack grooves on the pressing mechanism body, and the height of the piezoelectric stacks is slightly larger than the depth of the piezoelectric stack grooves.
Preferably, the piezoelectric stacks are made of PZT-8, the shapes of the piezoelectric stacks are cylindrical, and the polarization direction and the installation direction are the same; silver plating is applied to both ends of each piezoelectric stack for applying a voltage to the stack.
Preferably, the drive control circuit includes: the piezoelectric actuator comprises a central processing unit module, a pulse modulation module, a plurality of voltage output modules and a plurality of displacement signal conditioning modules, wherein the number of the voltage output modules and the number of the displacement signal conditioning modules correspond to the number of the piezoelectric stacks, the central processing unit module is integrated with the pulse modulation module, a computing core of the central processing unit module can be used for controlling waveform output and duty ratio of the pulse modulation module, high-frequency SPWM waves generated by the pulse modulation module are respectively output to the plurality of voltage output modules, and the voltage modules generate driving signals to be respectively applied to the plurality of piezoelectric stacks; deformation displacement of the piezoelectric stacks is monitored through a plurality of strain gauges arranged at the bottom of a concentric circular groove in the center of the bottom of the pressing machine mechanism body respectively and is output to each displacement signal conditioning module respectively, displacement signals measured by the strain gauges are fed back to the central processor module by the displacement signal conditioning modules respectively, the central processor module realizes nanoscale displacement resolving through a data fusion algorithm on the displacement signals, the displacement amplitude of the pressing machine mechanism is corrected through adjusting related parameters, and meanwhile automatic temperature compensation and single sensor fault correction according to ambient temperature are achieved.
Preferably, the voltage output module comprises a power amplification module and a switch module, wherein the power amplification module amplifies the current and voltage amplitude of the SPWM wave output by the pulse modulation module by using a power amplifier chip IR2110S, and is used for driving an MOS transistor of the switch module; the MOS tube of the switch module is connected with a high-voltage power supply, and the SPWM wave with the same frequency duty ratio as that of the SPWM wave generated by the pulse modulation module and amplified amplitude is generated through repeated switching on and switching off.
Has the advantages that: compared with the prior art, the high-precision press based on the piezoelectric material disclosed by the invention has the advantages that the high-precision and high-reliability advantages of the piezoelectric material are utilized, the mechanism generates deformation output acting force by applying voltage to the piezoelectric ceramic stack, micron-scale deformation control can be realized by utilizing the press device of the piezoelectric stack, the requirement of a pressing process is met, and the mechanism is simple in structure, high in reliability and long in service life. The drive control circuit of the high-precision press mainly adjusts the amplitude of the action voltage applied to the piezoelectric stack in real time through a central processing unit so as to correct the displacement offset caused by piezoelectric hysteresis. Meanwhile, the matching circuit of the invention adjusts the voltage of the piezoelectric stack by adopting a mode of adjusting the high-frequency unipolar single-side stepped SPWM duty ratio to change the equivalent voltage, and the stepped SPWM wave has the advantages of small harmonic distortion, high efficiency, large frequency bandwidth, good linearity and simple circuit structure. Compared with the traditional voltage-regulating power supply, the voltage-regulating mode can effectively reduce the energy loss in the circuit and improve the power supply efficiency.
Drawings
FIG. 1 is an overall structural view of a press mechanism of the present invention;
FIG. 2 is a schematic structural view of a press mechanism body according to the present invention;
FIG. 3 is a sectional view of the press mechanism body of the present invention cut along the section shown in FIG. 2, wherein (a) is a sectional view with a general section, and (b) is a sectional view with an arc-shaped groove;
FIG. 4 is a top view of the press mechanism of the present invention;
FIG. 5 is a bottom view of the press mechanism of the present invention;
FIG. 6 is a block diagram of the driving control circuit according to the present invention;
FIG. 7 is a schematic diagram of a power amplification circuit of the present invention;
FIG. 8 is a schematic diagram of a switching circuit of the present invention;
FIG. 9 is a graph of the SPWM sinusoidal modulated output voltage waveform of the present invention;
FIG. 10 is a schematic diagram of a signal amplifying and conditioning circuit of the strain gauge of the present invention;
FIG. 11 is a graph showing the relationship between the deformation of the piezo-electric stack and the output pressure;
FIG. 12 is a graph showing the relationship between the strain measured by a strain gauge attached to a press and the deformation of a piezoelectric stack according to the present invention;
in the figure, 1-the press mechanism body, 10-the first piezoelectric stack groove, 11-the second piezoelectric stack groove, 12-the third piezoelectric stack groove, 13-the fourth piezoelectric stack groove, 14-the fifth piezoelectric stack groove, 15-the concentric circular ring groove, 16-the central through hole, 17-the mounting hole, 18(a) -the inner circle arc groove, 18(b) -the outer circle arc groove, 19(a) -the inner circle top groove, 19(b) -the outer circle top groove, 2-the first piezoelectric stack, 3-the second piezoelectric stack, 4-the third piezoelectric stack, 5-the fourth piezoelectric stack, 6-the fifth piezoelectric stack, 7-the first wire guide groove, 8-the second wire guide groove, 9-the third wire guide groove, 10-the fourth wire guide groove, 11-the fifth wire guide groove, 12-a sixth lead slot, 13-a first strain gauge, 14-a second strain gauge, 15-a third strain gauge, 16-a fourth strain gauge, 17-a fifth strain gauge.
Detailed Description
The invention is described in further detail below with reference to the following figures and specific examples:
the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
In order to improve and meet the high preparation requirement of the modern ceramic technology, a ceramic press with high precision index needs to be designed so as to improve the uniformity and structural compactness of the ceramic and reduce the processing cost as much as possible. In order to break through the technical bottleneck that the traditional press is low in precision, the invention designs a high-precision press system using a piezoelectric stack, and micron-scale deformation control is realized by controlling the voltage amplitude applied to piezoelectric ceramics. The novel press manufactured by the piezoelectric stack can realize high-precision control of the output force amplitude of the press, realize one-step press forming, reduce or eliminate the workload of a grinding process, and reduce the processing cost and the processing period.
The pressing mechanism is controlled by the deformation of the piezoelectric ceramics, and the pressing mechanism comprises the pressing mechanism based on the piezoelectric ceramics and a driving control circuit. The pressing mechanism comprises a cylindrical pressurizing structure (pressing mechanism body) made of high-strength spring steel 65Mn and a piezoelectric stack for providing a pressure source for the pressing mechanism, the core of the driving control circuit is an equivalent voltage adjusting circuit which is applied to the piezoelectric stack by utilizing SPWM duty ratio adjustment, and the SPWM duty ratio adjustment is controlled by a central processing unit module. Cascaded SPWM ripples drive piezoelectric stack harmonic distortion is littleer than ordinary SPWM ripples, and efficiency is higher, and the piezoelectric stack drive circuit structure that adopts cascaded SPWM ripples is simpler, more does benefit to and integrates.
As shown in fig. 1-5, the pressing mechanism includes a pressing mechanism body 1 and a piezoelectric stack, where the piezoelectric stack includes a first piezoelectric stack 2, a second piezoelectric stack 3, a third piezoelectric stack 4, a fourth piezoelectric stack 5, and a fifth piezoelectric stack 6, the pressing mechanism body is cylindrical, in order to provide a certain amplitude of deformation for the structure, a concentric circular groove 15 is processed inside the pressing mechanism body, and the thinnest point of the top of the pressing mechanism body structure (i.e., the bottom position of the concentric circular groove) has a thickness dimension of 2 mm; the part acts on the applied mechanism through the auxiliary mechanism, and pressure with a certain magnitude is generated under the influence of the deformation of the piezoelectric stack and is applied to the ceramic to be pressed.
Cylindrical grooves which are uniformly distributed at 72 degrees, namely a first piezoelectric stack groove 10, a second piezoelectric stack groove 11, a third piezoelectric stack groove 12, a fourth piezoelectric stack groove 13 and a fifth piezoelectric stack groove 14 are processed on the top surface of the pressing machine mechanism body and are respectively used for mounting the first piezoelectric stack, the second piezoelectric stack, the third piezoelectric stack, the fourth piezoelectric stack and the fifth piezoelectric stack, each piezoelectric stack provides a pressure source for the pressing machine mechanism, and the stack deformation is adjusted by adjusting the voltages at the two ends of each piezoelectric stack, so that the output pressure of the pressing machine is changed. Because the press mechanism deforms after being pressed, in order to prevent the press from losing efficacy caused by overlarge deformation, the press mechanism is provided with the arc-shaped grooves comprising the arc-shaped grooves at the bottom of the concentric circular ring grooves and the arc-shaped grooves at the top of the press mechanism body, so that stress concentration in the press is reduced, and the service life is prolonged.
As shown in fig. 3, in order to cope with the two cross-sectional designs of the press deformation, the press mechanism is deformed after being pressed, so as to prevent the press from failing due to too large deformation. The invention is designed with two schemes, and fig. 3(a) shows that the section is a common section when the pressure is lower. When the pressure is higher, the invention is designed with an arc groove, comprising: an inner ring arc groove 18(a), an outer ring arc groove 18(b), an inner ring top groove 19(a), and an outer ring top groove 19(b), as shown in fig. 3(b), to reduce stress concentration in the press mechanism and improve service life.
The strain of a piezoelectric material resulting from an applied electric field is expressed in terms of the piezoelectric equation:
wherein SiIs the strain tensor of the piezoelectric material, dijIs the piezoelectric constant of the material, EiFor the applied electric field vector, TiIs the stress tensor of the piezoelectric material, along x for the polarization axis3The piezoelectric ceramic of (1) has a piezoelectric constant matrix of only d31,d33,d 153 independent components, so the piezoelectric strain constant matrix is:
the formula shows that the deformation of the piezoelectric stack is influenced by the magnitude of an external electric field, the deformation magnitude and the applied voltage amplitude basically keep a linear relation, the pressure output of the piezoelectric stack is directly influenced by the deformation of the piezoelectric stack, and the nano-scale control is performed on the deformation of the piezoelectric stack by using the voltage magnitude, so that the precision range of the output pressure of the press can be effectively improved.
Fig. 4 is a top view of the pressing mechanism, and it can be seen that a wire groove structure is processed on the side surface of a cylindrical groove (piezoelectric stack groove) for installing the piezoelectric stack in the pressing mechanism body, and the wire groove is used for communicating with the adjacent piezoelectric stack groove; a first wire groove 7, a second wire groove 8, a third wire groove 9, a fourth wire groove 10 and a fifth wire groove 11. A summary wire groove, namely a sixth wire groove 12 is processed on the outer side of one of the piezoelectric stack grooves, and the sixth wire groove penetrates through the pressing machine mechanism body; five stacked power supply wires are uniformly connected to the drive control circuit through the sixth wire groove.
Five mounting holes 17 are uniformly formed in the radial direction of the pressing machine mechanism body, and each mounting hole is located between every two adjacent piezoelectric stack grooves.
The shape of the piezoelectric stacks is matched with that of the piezoelectric stack grooves on the pressing mechanism body, the number of the piezoelectric stacks corresponds to that of the piezoelectric stack grooves on the pressing mechanism body, and the height of each piezoelectric stack is larger than the depth of each piezoelectric stack groove.
The piezoelectric stack is made of PZT-8, and the ceramic has low dielectric loss and high mechanical strength; the piezoelectric stacks are cylindrical, and the polarization direction and the installation direction are the same; silver plating is applied to both ends of each piezoelectric stack for applying a voltage to the stack.
The press system needs to test the displacement response condition of the press mechanism, and the displacement test is carried out by obtaining a strain-displacement output curve (shown in fig. 12) of the press mechanism through simulation and adopting a mode of indirect measurement of a strain gauge. As shown in fig. 5, five strain gauges, namely a first strain gauge 13, a second strain gauge 14, a third strain gauge 15, a fourth strain gauge 16 and a fifth strain gauge 17, are used as strain gauge combinations for testing the displacement of the press, and each strain gauge is adhered to the bottom of the concentric circular groove in the same distribution manner as the piezoelectric stacks, i.e., in 72-degree symmetrical arrangement, and corresponds to five groups of piezoelectric stacks one by one. The strain gauge is distributed symmetrically, and the nanoscale detection of displacement is realized through a data fusion algorithm, so that the closed-loop control is facilitated.
In order to reduce the performance loss of the press caused by the hysteresis effect and carry out high-precision control on the deformation of the press, the invention designs a closed-loop driving circuit for the piezoelectric stack, carries out real-time tracking and control on the deformation displacement of the piezoelectric stack, compensates the stack displacement error caused by the hysteresis effect and realizes the high-precision performance output of the press.
The drive control circuit shown in fig. 6 includes: the central processing unit module mainly comprises a DSP chip, an FPGA chip or other MCU chips with similar functions and peripheral circuits thereof, and is used for receiving displacement signals obtained by a feedback loop, realizing nanoscale displacement calculation by adopting a data fusion algorithm and simultaneously carrying out intelligent temperature compensation and single sensor fault correction; and on the other hand, the pulse modulation module is used for controlling parameters such as SPWM waveform output, duty ratio and the like of the pulse modulation module. The high-frequency SPWM waves generated by the pulse modulation module are respectively output to a first voltage output module, a second voltage output module, a third voltage output module, a fourth voltage output module and a fifth voltage output module and are used as voltage outputs to be respectively acted on a first piezoelectric stack, a second piezoelectric stack, a third piezoelectric stack, a fourth piezoelectric stack and a fifth piezoelectric stack; the first to fifth voltage output modules include first to fifth power amplification modules and first to fifth switching modules. The first to fifth power amplification modules amplify the current and voltage amplitude of the SPWM wave by using a power amplifier chip (IR2110S) and are respectively used for driving MOS (metal oxide semiconductor) tubes of the first to fifth switch modules; the MOS tubes of the first to fifth switch modules are connected with a high-voltage power supply, and the frequency duty ratio of the SPWM wave generated by the pulse modulation module is the same as that of the SPWM wave generated by the pulse modulation module through repeated switching on and switching off, but the amplitude of the SPWM wave is amplified. Each strain gauge transmits the displacement of the corresponding piezoelectric stack to the corresponding displacement signal conditioning module, each displacement signal conditioning module feeds back a displacement signal to the central processor module, and the central processor module is used for responding to the displacement generated by the piezoelectric stack and correcting the displacement amplitude of the whole machine by adjusting related parameters so as to eliminate the hysteresis effect brought by the piezoelectric stack. Because the output force of the piezoelectric stack and the voltage acting on the piezoelectric stack meet a linear relation, the amplitude of the output acting force of the press can be directly adjusted by adjusting the SPWM wave duty ratio of the pulse modulation module.
In order to reduce the influence of an equivalent voltage application mode on the piezoelectric performance, the SPWM wave frequency of the drive control circuit designed by the invention exceeds 100kHz, and voltage amplitudes with different sizes can be equivalent by adjusting the duty ratio of the SPWM wave. The amplitude of the SPWM wave is the equivalent voltage amplitude with the duty ratio of 100%, the amplitude of the SPWM wave reduced to the first dead zone range can be regarded as 0V, and the duty ratio in the middle range is linearly related to the voltage amplitude. The pulse modulation module is a key component of a drive control circuit and generates a group of high-frequency unipolar stepped SPWM signals with the frequency exceeding 100kHz, and the group of signals comprises So1、So2、So3、So4By adjusting the duty cycle of the SPWM and So1、So2、So3、So4High and low levels simulate different magnitudes of voltage.
So1、So2、So3、So4The signal passes through the power amplification module shown in FIG. 7 to generate the switching signal S1、S2、S3、S4The SPWM signal has the same polarity as the switching signal. The power amplification module comprises a first processor U1A second processor U2A first resistor R1A second resistor R2A third resistor R3A fourth resistor R4A first capacitor C1A second capacitor C2，So1Through a first resistor R1Input to a first processor U1Pin 2, So2Through a second resistor R2Input to a first processor U1Pin 3, first processor U1Pins 4 and 7 of (2) are grounded, and the first processor U1Pins 1 and 5 of (2) are connected to Vcc, Vcc passing through capacitor C1Grounded, first processor U1Pin 6 and 8 respectively output signal S1And S2；So3Through a third resistor R3Input to a second processor U2Pin 2, So4Through a fourth resistor R4Input to a second processor U2Pin 3, second processor U2Pins 4 and 7 of the second processor U are grounded2 Pins 1 and 5 of (2) are connected to Vcc, Vcc passing through capacitor C2Grounded, second processor U2Pin 6 and 8 respectively output signal S3And S4。
S1、S2、S3、S4The signal is inputted into a switching circuit shown in FIG. 8, the switching circuit includes a power supply UDCA fifth resistor R5A sixth resistor R6A seventh resistor R7An eighth resistor R8A first switch tube M1A second switch tube M2And a third switch tube M3And a fourth switch tube M4。S1、S2、S3、S4When all are high, M1、M2、M3、M4The output amplitude of the SPWM wave is 400V at most; s1Is at a low level, S2、S3、S4When the voltage is at a high level, the voltage is low,M1disconnection, M2、M3、M4Closing, wherein the output amplitude of the SPWM wave is 300V at most; wherein S is1、S2Is at a low level, S3、S4At high level, M1、M2Disconnection, M3、M4Closing, wherein the maximum output amplitude of the SPWM wave is 200V; s1、S2、S3Is at a low level, S4At high level, M1、M2、M3Disconnection, M4Closing, wherein the output amplitude of the SPWM wave is 100V at most; wherein S is1、S2、S3、S4When all are low, M1、M2、M3、M4The output amplitude of the SPWM wave is 0V; within each step, S1、S2、S3、S4The magnitude of the duty cycle is substantially linearly related to the magnitude of the voltage amplitude. The harmonic distortion of the stepped SPWM wave driving piezoelectric stack is smaller than that of a common SPWM wave, the efficiency is higher, and higher integration level can be realized. The switching circuit generates a presser drive SPWM waveform as shown in fig. 9.
As can be seen from the relationship between the deformation of the piezoelectric stack and the output pressure of the press shown in fig. 11, the output force of the press and the deformation amplitude of the piezoelectric stack are in a linear relationship, and the output force of the press increases with the increase of the deformation of the piezoelectric stack. Therefore, the output torque of the press can be controlled by controlling the deformation of the piezoelectric stack. The invention designs a sensing system for measuring the deformation displacement of a piezoelectric stack. Because the structure is complicated due to the directly measured displacement sensor, the invention adopts an indirect displacement measurement mode, and measures the displacement caused by stack deformation by sticking a strain gauge to measure the strain at the flexible structure of the press, and the relationship between the press deformation and the piezoelectric stack displacement is shown in figure 12.
The test system comprises a displacement signal sensing module and a displacement signal amplifying module. The displacement signal sensing module is a strain gauge and comprises a first strain gauge, a second strain gauge, a third strain gauge, a fourth strain gauge and a fifth strain gauge, and the signal amplification module comprises a first signal amplification module, a second signal amplification module, a third bit signal amplification module, a fourth bit signal amplification module and a fifth bit signal amplification module. Voltages at two ends of the first strain gauge, the second strain gauge, the third strain gauge, the fourth strain gauge and the fifth strain gauge are respectively used as a first piezoelectric stack displacement signal, a second piezoelectric stack displacement signal, a third piezoelectric stack displacement signal, a fourth piezoelectric stack displacement signal and a fifth piezoelectric stack displacement signal, the first piezoelectric stack displacement signal, the second piezoelectric stack displacement signal, the third piezoelectric stack displacement signal, the fourth piezoelectric stack displacement signal and the fifth piezoelectric stack displacement signal are amplified by the sampling and signal amplifying module and then input into the central processing unit module, and the central processing unit module adopts a data fusion algorithm to measure data measured by the five strain gauges to realize nanoscale displacement measurement, so that automatic temperature compensation and single sensor fault correction according to ambient temperature are realized.
Because the amplitude of the output signal of the strain gauge is small, which is not beneficial to the data processing of the central processing unit, the signal amplification circuit shown in fig. 10 is adopted to amplify the amplitude of the signal. The core of the signal amplifying circuit is an operational amplifying chip U3Model number AD620, strain gauge and reference resistor RrefAfter being connected in series and supplied with power by a power supply Vs, the voltage difference between the two ends of the resistor are respectively passed through a resistor R9And R10Is used as a displacement signal of the piezoelectric stack and is subjected to an operational amplification chip U3After being input by a pin 2 and a pin 3, the signals are processed by an operational amplifier chip U36 pin output, capacitor C5，C6And C7Is an input signal filter capacitor. The operational amplifier chip U3The 7 pins and the 4 pins are respectively connected with the positive electrode + Vs and the negative electrode-Vs of the bipolar power supply, and the capacitor C3，C4，C8And C9Is a filter capacitor for the power supply signal. Operational amplification chip U3A programmable resistor R is connected between the pin 1 and the pin 8GBy varying the programmable resistance RGSize change operational amplification chip U3The amplification amplitude of (a). Operational amplification chip U3And 5 feet as reference ground.
For the press mechanism designed by the invention, the deformation amplitude of the press mechanism is influenced by the deformation of the piezoelectric stack, in order to control the deformation of the piezoelectric stack, the single-polarity single-side stepped SPWM circuit is adopted to drive the piezoelectric stack, and the equivalent voltage amplitude applied to the piezoelectric stack is changed by adjusting the duty ratio of SPWM waves.
The press device designed by the invention has the advantages of simple integral structure, convenience in installation, higher reliability and precision and higher efficiency, and the deformation amplitude of the press device is directly controlled by voltage.
Claims (8)
1. A high-precision press system for ceramic preparation based on a piezoelectric structure is characterized by comprising a press mechanism and a drive control circuit, wherein the press mechanism comprises a press mechanism body and a piezoelectric stack, the piezoelectric stack is arranged on the press mechanism body and used for providing a pressure source for the press system, and the press mechanism body acts the pressure generated by the deformation of the piezoelectric stack on an applied mechanism through an auxiliary mechanism; the driving control circuit utilizes the SPWM duty cycle to adjust the voltage applied to the piezoelectric stack, further controls the displacement of the piezoelectric stack, realizes the conversion of the voltage into the deformation displacement of the piezoelectric stack, and simultaneously, the pressure generated by the deformation of the piezoelectric stack is applied to the ceramic to be pressed.
2. The high-precision press system for ceramic preparation based on piezoelectric structures as claimed in claim 1, wherein the press mechanism body is a cylindrical ceramic structure, a concentric circular groove is formed in the center of the bottom of the press mechanism body, the thickness of the bottom of the concentric circular groove is 0.5mm to 2mm, the portion is acted on the applied mechanism through an auxiliary mechanism, a central through hole is formed in the center of the concentric circular groove, a plurality of piezoelectric stack grooves are uniformly formed around the concentric circular groove, the piezoelectric stack grooves are used for installing a plurality of corresponding piezoelectric stacks respectively, wire grooves are formed between the side walls of adjacent piezoelectric stack grooves, and a summary wire groove is formed in the outer side wall of one of the piezoelectric stack grooves, penetrates through the press mechanism body, and is used for uniformly connecting all power supply wires of the piezoelectric stacks to a driving control circuit.
3. The piezoelectric structure-based ceramic-made high-precision press system according to claim 2, wherein the concentric circular ring bottom grooves are further provided with inner circular ring arc grooves and outer circular ring arc grooves at the bottom, and top arc grooves corresponding to the inner circular ring arc grooves and the outer circular ring arc grooves respectively are also provided at the top of the press mechanism body, so as to reduce stress concentration in the press mechanism.
4. The high-precision press system for ceramic preparation based on piezoelectric structures as claimed in claim 2, wherein the press mechanism body is further provided with mounting holes at the periphery of the piezoelectric stack grooves and between every two adjacent piezoelectric stack grooves.
5. The piezoelectric structure-based ceramic-making high-precision press system according to claim 1, wherein the shape and number of the piezoelectric stacks are matched with those of the piezoelectric stack grooves on the press mechanism body, and the height of the piezoelectric stacks is greater than the depth of the piezoelectric stack grooves.
6. The piezoelectric structure-based ceramic preparation high-precision press system is characterized in that the piezoelectric stacks are made of PZT-8, cylindrical in shape and same in polarization direction and installation direction; silver plating is applied to both ends of each piezoelectric stack for applying a voltage to the stack.
7. The piezoelectric structure-based ceramic fabrication high precision press system of claim 1, wherein the drive control circuit comprises: the piezoelectric actuator comprises a central processing unit module, a plurality of voltage output modules and a plurality of displacement signal conditioning modules, wherein the number of the voltage output modules and the number of the displacement signal conditioning modules correspond to the number of the piezoelectric stacks, the central processing unit module is integrated with a pulse modulation module, a calculation core of the central processing unit module can be used for controlling waveform output and duty ratio of the pulse modulation module, high-frequency SPWM waves generated by the pulse modulation module are respectively output to the plurality of voltage output modules, and the voltage modules generate driving signals to be respectively acted on the plurality of piezoelectric stacks; deformation displacement of the piezoelectric stacks is monitored through a plurality of strain gauges arranged at the bottom of a concentric circular groove in the center of the bottom of the pressing machine mechanism body respectively and is output to each displacement signal conditioning module respectively, displacement signals measured by the strain gauges are fed back to the central processor module by the displacement signal conditioning modules respectively, the central processor module realizes nanoscale displacement resolving through a data fusion algorithm on the displacement signals, the displacement amplitude of the pressing machine mechanism is corrected through adjusting related parameters, and meanwhile automatic temperature compensation and single sensor fault correction according to ambient temperature are achieved.
8. The ceramic-preparation high-precision press system based on the piezoelectric structure as claimed in claim 7, wherein the voltage output module comprises a power amplification module and a switch module, wherein the power amplification module utilizes a power amplifier chip IR2110S to amplify the current and voltage amplitude of the SPWM wave output by the pulse modulation module and is used for driving an MOS (metal oxide semiconductor) transistor of the switch module; the MOS tube of the switch module is connected with a high-voltage power supply, and the SPWM wave with the same frequency duty ratio as that of the SPWM wave generated by the pulse modulation module and amplified amplitude is generated through repeated switching on and switching off.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008245339A (en) * | 2007-03-23 | 2008-10-09 | Honda Motor Co Ltd | Control method of piezoelectric actuator |
| CN102723432A (en) * | 2012-07-04 | 2012-10-10 | 陈�峰 | Piezoelectric driving device integrating resistor strain sheet-type sensor and manufacture method thereof |
| CN106059385A (en) * | 2016-07-20 | 2016-10-26 | 南京理工大学 | Piezoelectric ceramic driving power supply with hysteresis compensation function |
| CN108448928A (en) * | 2018-05-07 | 2018-08-24 | 合肥工业大学 | A kind of more stacked piezoelectric actuator independence time-sharing driving devices and method |
| CN110768569A (en) * | 2019-11-11 | 2020-02-07 | 华侨大学 | Cut rate-based piezoelectric ceramic anti-hysteresis driving method |
-
2020
- 2020-12-25 CN CN202011562544.9A patent/CN112720790B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008245339A (en) * | 2007-03-23 | 2008-10-09 | Honda Motor Co Ltd | Control method of piezoelectric actuator |
| CN102723432A (en) * | 2012-07-04 | 2012-10-10 | 陈�峰 | Piezoelectric driving device integrating resistor strain sheet-type sensor and manufacture method thereof |
| CN106059385A (en) * | 2016-07-20 | 2016-10-26 | 南京理工大学 | Piezoelectric ceramic driving power supply with hysteresis compensation function |
| CN108448928A (en) * | 2018-05-07 | 2018-08-24 | 合肥工业大学 | A kind of more stacked piezoelectric actuator independence time-sharing driving devices and method |
| CN110768569A (en) * | 2019-11-11 | 2020-02-07 | 华侨大学 | Cut rate-based piezoelectric ceramic anti-hysteresis driving method |
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