High-frequency vibration table

Abstract

The invention discloses a high-frequency vibration table which comprises a vibration table body which comprises a magnet exciting coil, a moving coil and an induction ring, and the moving coil generates vibration through interaction of a constant magnetic field generated by the induction ring and the magnet exciting coil. And the power amplification system adopts a sine pulse width modulation technology, and controls a power switch to output an amplified sine signal to drive a moving coil through a logic driving module. And the cooling system is used for cooling the vibration table induction ring and the power amplifier. And the central zero system is used for monitoring the position of the moving coil and enabling the moving coil to be always in a vibration balance position. A combined structure of the magnet exciting coil, the moving coil and the induction ring is adopted, more stable vibration output can be achieved through interaction of the induction ring and a magnetic field, the vibration frequency can be flexibly adjusted through interaction of a constant magnetic field generated by the magnet exciting coil and the moving coil, the vibration table can adapt to vibration testing requirements of different frequencies, and the application range of the vibration table is widened.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration tables, and particularly to a high-frequency vibration table. Background Art

[0002] Electromagnetic vibration tables are key test equipment necessary for the development of aerospace (military) products such as rockets, missiles, and satellites. They are widely used in tests such as product strength verification, transportation environment detection, and reliability. They are involved in the development of products in various industries such as aerospace, aviation, shipbuilding, automobiles, and trains and the verification of products under simulated working conditions. The vibration test equipment generates exciting force by the interaction of the alternating current of the driving coil and the constant magnetic field to drive the moving parts. The electromagnetic vibration table utilizes the principle of electromagnetic induction. In an electromagnetic vibration table, generally there are two coils, one fixed on the base and the other fixed on the movable vibration table. When current passes through the fixed coil, the generated magnetic field causes the metal mass block on the vibration table to vibrate. The vibration frequency can be controlled by changing the frequency of the power supply. Since the frequency provided by the power supply is very stable, the electromagnetic vibration table has high precision, high stability, and reliability. For products for high-frequency reliability tests, such as the turbine fan blades of aeroengines, etc. When an ordinary electromagnetic vibration table vibrates at high frequencies, due to factors such as signal interference, unstable mechanical structure, and insufficient heat dissipation, the highest vibration frequency is 2500 Hz, making it difficult to meet the high-precision test requirements. Summary of the Invention

[0003] To overcome the above disadvantages, the purpose of the present invention is to provide a high-frequency vibration table to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is a high-frequency vibration table, which is characterized by comprising: A vibration table body, including an exciting coil, a moving coil, and an induction ring. The moving coil interacts with the constant magnetic field generated by the exciting coil through the induction ring to generate vibration.

[0005] A power amplifier system, adopting sine pulse width modulation technology, and controlling the power switch through a logic drive module to output an amplified sine signal to drive the moving coil.

[0006] A cooling system, used for dissipating heat from the induction ring of the vibration table and the power amplifier.

[0007] A central zero position system, used for monitoring the position of the moving coil and making the moving coil always in the balanced position of vibration.

[0008] Preferably, the vibration table body adopts an inductive structure. The moving coil and the induction ring are fixedly connected by high-temperature glue. The driving coil is fixed inside the magnetic cylinder ring, and the alternating current is induced to the surface of the induction ring through the principle of a tubular transformer.

[0009] Preferably, the power amplifier system includes: A buffer module for anti-interference processing of the input signal.

[0010] A carrier generator module for generating a triangular wave signal with stable frequency.

[0011] A pulse width modulation module for comparing the buffered output signal and the feedback signal with the triangular wave to generate a rectangular wave with adjustable duty cycle.

[0012] A logic drive module for shunting and delaying the PWM signal and adding a synchronization pulse protection.

[0013] An isolation buffer module for level isolation of the signal sent by the logic drive part and for voltage drive or current drive; A power switch module using high-speed power semiconductor devices with a full-bridge topology, and the output end is connected to an inductive load.

[0014] A filter module configured as a low-pass filter with a cut-off frequency lower than the carrier frequency.

[0015] A voltage negative feedback loop for achieving deep voltage negative feedback.

[0016] Preferably, the logic drive module includes: A signal shunting unit for splitting the PWM signal into four drive signals.

[0017] A delay control unit for setting an adjustable delay of 0.1 - 2 μs to prevent the bridge arm from being directly connected.

[0018] A synchronization pulse injection unit for receiving a pulse width limit signal to force the switch cycle to reset.

[0019] Preferably, the frequency stability of the triangular wave generated by the carrier generator module is better than ±0.1%, and the linearity error is less than 1%. The power switch module includes a three-phase full-bridge rectifier unit, a DC bus capacitor bank, and four half-bridge power units. The input voltage of the three-phase full-bridge rectifier unit is 380VAC ± 10%. The DC bus capacitor bank is configured with voltage equalizing resistors and discharge circuits. Each half-bridge of the four half-bridge power units is configured with an independent drive isolation circuit.

[0020] Preferably, the cooling system includes a deionized water filtration system and nozzles, which automatically trigger spraying when the drive current exceeds the set current value, and spray deionized water onto the surface of the induction ring to enhance heat dissipation.

[0021] Preferably, the central zero - position system includes a central zero - position controller, an optoelectronic sensor, an air - spring assembly, and a moving - coil guiding assembly. The optoelectronic sensor is correspondingly arranged with the moving coil. The air - spring assembly includes an upper air spring and a lower air spring respectively arranged on the upper and lower sides of the moving coil. The moving - coil guiding system includes a guiding shaft and a guiding bearing, and dynamically adjusts the height of the moving coil through the air spring, and realizes the displacement and overload protection of the moving coil in combination with the central zero - position controller.

[0022] Preferably, the vibration table body further includes a horizontal slide - table switching mechanism, which is locked by trunnions and air springs and fixed by wall - plate screws, and is used for quickly switching between vertical and horizontal vibration modes.

[0023] Preferably, the high - frequency vibration table further includes a single - point grounding system, which eliminates ground - loop interference through an independent grounding wire, and is used to enable the power - amplifier system and the vibration controller with the output waveform to realize signal transmission by using an isolation transformer.

[0024] Preferably, the vibration table body and the power amplifier are connected by a standardized cable. The standardized cable includes a moving - coil wire (O +, O -), an exciting wire (F +, F -), and an interlock protection wire. Description of the Drawings

[0025] Figure 1 It is a principle block diagram of the power - amplifier system of an embodiment of a high - frequency vibration table of the present invention; Figure 2 It is a front - view schematic diagram of an embodiment of a high - frequency vibration table of the present invention; Figure 3 It is a side - view schematic diagram of an embodiment of a high - frequency vibration table of the present invention, where the vibration table is in a vertical vibration mode; Figure 4 It is a partial - structure schematic diagram of an embodiment of a high - frequency vibration table of the present invention, where the vibration table is in a horizontal vibration mode; In the figure: 1. Vibration table body; 2. Upper air spring; 3. Lower air spring; 4. Air - floating; 5. Cable and water - pipe connection terminal; 6. Wall panel; 7. Locking screw; 8. Horizontal slide - table switching mechanism; 9. Connector; 10. Horizontal limit switch; 11. Central indicating scale; 12. Horizontal slide table; 13. Buffer module; 14. Carrier - generator module; 15. Pulse - width modulation module; 16. Logic - drive module; 17. Power - switch module; 18. Filter module; 19. Voltage negative - feedback loop; 20. Isolation buffer module; 21. Load. Detailed Embodiments

[0026] The following describes in detail the preferred embodiments of the present invention with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined.

[0027] Reference Figures 1 to 4 , Figure 1 shows a schematic block diagram of a power amplifier system of a high-frequency vibration table provided by an embodiment of the present invention; Figure 2 shows a front view of a high-frequency vibration table provided by an embodiment of the present invention; Figure 3 shows a side view of a high-frequency vibration table provided by an embodiment of the present invention, where the vibration table is in a vertical vibration mode; Figure 4 shows a partial structural view of a high-frequency vibration table provided by an embodiment of the present invention, where the vibration table is in a horizontal vibration mode.

[0028] As Figures 1 to 4 shown, the technical solution provided by the present application is a high-frequency vibration table, including: A vibration table body 1, including an excitation coil, a moving coil and an induction ring. The moving coil interacts with the constant magnetic field generated by the excitation coil through the induction ring to generate vibration.

[0029] A power amplifier system, adopting sine pulse width modulation technology, controls the power switch to output an amplified sine signal to drive the moving coil through a logic drive module 16.

[0030] A cooling system, used for dissipating heat from the induction ring of the vibration table and the power amplifier.

[0031] A center zero position system, used for monitoring the position of the moving coil and keeping the moving coil always in the balanced position of vibration.

[0032] The high-frequency vibration table provided by the present application adopts a combined structure of an excitation coil, a moving coil and an induction ring. Wall panels 6 are provided on both sides of the vibration table body 1 as supports. This structure can more precisely control the generation and transmission of vibration. Through the interaction between the induction ring and the magnetic field, more stable vibration output can be achieved. The interaction between the constant magnetic field generated by the excitation coil and the moving coil can flexibly adjust the vibration frequency, enabling it to adapt to the vibration test requirements of different frequencies and broadening the application range of the vibration table. Sine pulse width modulation (SPWM) technology can generate high-quality sine signals with small waveform distortion and low harmonic content, thereby providing a purer and more stable drive signal for the moving coil, making the vibration of the vibration table more stable and uniform and improving the accuracy of the test results. The center zero position system monitors and adjusts the position of the moving coil to ensure that it is always in the balanced position, which can effectively reduce the offset and error during vibration and improve the accuracy and stability of vibration.

[0033] In some embodiments, reference Figures 1 to 4, the vibration table body 1 adopts an inductive structure. The moving coil and the induction ring are fixedly connected by high-temperature glue. The driving coil is fixed inside the magnetic cylinder ring, and the alternating current is induced to the surface of the induction ring through the principle of a cylindrical transformer.

[0034] Exemplarily, the driving between the moving coil and the induction ring is achieved through electromagnetic induction without direct contact. At the same time, the high-temperature glue can maintain good bonding performance in a high-temperature environment. The high-temperature glue curing connection can distribute stress more evenly, avoid structural damage caused by stress concentration at the connection points, and enhance the anti-fatigue performance of the vibration table.

[0035] Ensure that the moving coil and the induction ring will not loosen or fall off during vibration, improving the stability of the structure, especially under high-frequency vibration and high-temperature working conditions.

[0036] In some embodiments, referring to Figures 1 to 4 , the power amplifier system includes: A buffer module 13 for anti-interference processing of the input signal; A carrier generator module 14 that generates a triangular wave signal with stable frequency; A pulse width modulation module 15 that compares the buffered output signal and the feedback signal with the triangular wave to generate a rectangular wave with adjustable duty cycle; A logic drive module 16 that performs shunt delay processing on the PWM signal and adds a synchronous pulse protection; An isolation buffer module 20 for level isolation of the signal sent by the logic drive part and performing voltage drive or current drive; A power switch module 17 that uses high-speed power semiconductor devices with a full-bridge topology, and the output end is connected to an inductive load 21; A filter module 18 configured as a low-pass filter with a cut-off frequency lower than the carrier frequency; A voltage negative feedback loop 19 to achieve deep voltage negative feedback.

[0037] Exemplarily, the logic drive module 16 mainly undertakes the task of receiving the pulse wave transmitted by the pulse width modulation module 15. Inside this module, the pulse wave will be distributed to twelve different channels. In practical applications, power devices are not ideal switches, and there is a certain delay in their switching actions, namely the rise time and the fall time. To avoid the occurrence of the bad situation where the power switches on the same bridge arm conduct simultaneously, dead times are set for the pulse waves distributed to the twelve channels. The length of the dead time is determined according to the switching time of the power switch. On the premise of ensuring that the power switches will not conduct simultaneously, the shorter the dead time, the more beneficial it is to ensure the accuracy of the signal, otherwise the sine wave obtained after demodulation will be significantly distorted.

[0038] Meanwhile, to prevent the signal in the input buffer from being too large, which may cause the carrier signal to lose the intersection point with the input signal and then lead to the problem of the power switch being continuously turned on for a long time, the logic drive part also receives the synchronization pulse from the pulse width limitation part. This design can ensure that the power switch can still be turned on and off according to the established switching frequency when a fault occurs in the pulse width modulation part, thus effectively protecting the power device and preventing it from being damaged due to abnormal conditions.

[0039] The power switch adopts a full-bridge switch structure, and each switch requires an independent and relatively independent drive signal. The isolation buffer part is responsible for performing level isolation processing on the signal output by the logic drive part. In this process, it will be determined whether to use voltage drive or current drive according to the specific characteristics of the power switch. The isolation buffer part needs to have a high common-mode interference resistance ability to ensure the stability of signal transmission; at the same time, the signal transmission delay should be as small as possible to improve the response speed of the system; in addition, it should have a low dynamic internal resistance to reduce energy loss. More importantly, this part needs to be able to provide reliable protection against instantaneous overcurrent and short-circuit faults of the power device. The performance of the isolation buffer part is directly related to the conversion efficiency of the switched-mode power amplifier, and its performance is one of the key factors affecting the efficiency of the entire system.

[0040] The function of the power switch part is to amplify the sine width modulation pulse sent by the isolation buffer part. This part works in a switching state. Under high-frequency, high-speed, and large-current conditions, it is required that the semiconductor power switch has a wide safe operating area and a large short-circuit capacity. The power device generally selects a power field effect transistor or a power field effect module, depending on the power size. Since the load 21 of the electric stage has an inductive characteristic, when the power switch is turned off, an overvoltage will be generated. When this voltage is too high, it will damage the power switch, so it must be suppressed. Usually, there are two methods: one is to add an absorption (buffer) circuit to the power switch; the other is that in the actual layout, the connection of the power switch part should be as short as possible.

[0041] The function of the filtering part is to restore the high-power discrete pulse sent by the power switch into a continuous (current) voltage output. The requirements for this part are: it can effectively suppress the carrier signal without attenuating the modulation signal. At the same time, it has a high quality factor. Generally, the driving method of the electric vibration table is constant voltage driving, which requires that the power amplifier should have a low output impedance. To achieve this goal, the power amplifier introduces deep voltage negative feedback to ensure that when the grid voltage fluctuates and the vibration frequency changes, causing the impedance of the vibration table to change, the output voltage of the power amplifier remains constant.

[0042] In some embodiments, referring to Figures 1 to 4 , the logic drive module 16 includes: A signal splitting unit that splits the PWM signal into four drive signals.

[0043] A delay control unit is configured to set an adjustable delay of 0.1 - 2 μs to prevent shoot-through of the bridge arms.

[0044] A synchronous pulse injection unit receives a pulse width limit signal to force a reset of the switching period.

[0045] Exemplarily, in a full-bridge topology, shoot-through of the bridge arms (i.e., simultaneous conduction of the upper and lower bridge arms) will cause a short circuit in the power supply and damage the power devices. By setting an adjustable delay, it is ensured that there is sufficient time interval between the switching actions of the upper and lower bridge arms to avoid the occurrence of shoot-through. The adjustable delay range of 0.1 - 2 μs can meet the requirements under different operating frequencies and load conditions, providing high-precision control capabilities and ensuring reliability in high-frequency switching applications. By receiving the pulse width limit signal and forcing a reset of the switching period, it is possible to effectively avoid switching errors caused by abnormal pulses or signal interference, ensuring that the power switching devices operate in a safe state.

[0046] The logic module adopts unipolar frequency doubling modulation to increase the output PWM switching frequency, thereby reducing the burden on the main inverter circuit. Different from the bipolar PWM modulation method, the unipolar PWM frequency doubling modulation uses two reference sine waves with opposite polarities to intersect with a bidirectional triangular wave to generate the power switch drive signal. In this way, the frequency of the output voltage between the midpoints of the main circuit bridge arms can be doubled without changing the IGBT switching frequency, thereby reducing the switching loss and the volume of the output filter and improving the waveform quality.

[0047] Another function of the logic module is that the monitoring system not only provides protection for the switching power amplifier itself but also provides protection for the displacement over-travel of the moving system of the vibration table and the overheating of the heating components of the vibration table. A group of fault indicator lights indicate the nature of the fault. When any one of the fault indicator lights is on, the input excitation signal is automatically blocked by the interlock protection system. In addition, in order to take away most of the heat stored inside the table body during shutdown, a cooling delay shutdown circuit is set, generally with a delay of 5 minutes. The excitation power supply is obtained by stepping down and rectifying the main power supply through an excitation transformer to supply the DC excitation current for the excitation coil of the vibration table. Due to the energy storage effect of the excitation coil, to prevent overvoltage when the coil is powered off, this power supply provides an excitation discharge protection function, and at the same time, an excitation power supply overheat protection function is set.

[0048] The power module adopts a single-axis pulse width modulation amplifier (PCI) and operates in voltage mode. Its rated current is 100 A rms and the peak value is 400 A. It is powered by a 300 V DC power supply. In the case of an input sine signal, each half-bridge can perform sine modulation, so that the working cycle changes at a sine wave frequency, and different phases appear at each output end, thereby an amplified sine signal appears at the output end.

[0049] In some embodiments, referring to Figures 1 to 4 , the triangular wave generated by the carrier generator module 14 has a frequency stability better than ±0.1% and a linearity error less than 1%. The power switch module 17 includes a three-phase full-bridge rectification unit, a DC bus capacitor bank, and four groups of half-bridge power units. The input voltage of the three-phase full-bridge rectification unit is 380VAC ± 10%. The DC bus capacitor bank is configured with voltage equalizing resistors and discharge circuits. Each half-bridge of the four groups of half-bridge power units is configured with an independent drive isolation circuit.

[0050] Exemplarily, a triangular wave carrier signal with a frequency stability better than ±0.1% provides an extremely stable reference for pulse width modulation (PWM). Such a high-precision carrier signal can ensure more accurate duty cycle control of the PWM signal, thereby improving the output signal quality of the power amplifier system and reducing the instability of the output voltage or current caused by carrier frequency fluctuations.

[0051] In some embodiments, referring to Figures 1 to 4 , the cooling system includes a deionized water filtration system and nozzles. When the drive current exceeds the set current value, spraying is automatically triggered to spray deionized water onto the surface of the induction ring to enhance heat dissipation.

[0052] Exemplarily, deionized water has a high thermal conductivity and specific heat capacity, and can quickly absorb and conduct heat. Compared with traditional air cooling or other cooling media, it can more effectively reduce the temperature of the induction ring surface. The nozzles can evenly spray deionized water onto the surface of the induction ring, forming a large-area cooling contact to quickly take away the heat generated by the induction ring, significantly improving the heat dissipation efficiency. The cooling system is also provided with corresponding cable and water pipe connection terminals 5 for connecting to the deionized water filtration system and nozzles respectively.

[0053] During the operation of the induction vibration table, due to the presence of induced current in the induction ring, a large amount of heat is generated. To solve the heat dissipation problem, by optimizing the air duct of the vibration table body, a high-efficiency exhaust fan is used to quickly take out its heat, so that the temperature inside the table body reaches equilibrium. During high-magnitude, large-acceleration, and long-time operation, to reduce the temperature of the induction ring surface and improve the heat dissipation capacity, when the drive current exceeds 375A, the spray switch is triggered. The spray water source is tap water, which undergoes a series of deionization treatments such as primary and secondary water quality filtration and mixed bed filtration through a filter, so that the resistivity of the water outlet reaches 1 - 18MΩ·CM, and the water is sprayed to the magnetic gap through the nozzles to quickly cool the temperature of the induction ring surface.

[0054] In some embodiments, referring to Figures 1 to 4, The central zero position system includes a central zero position controller, a photoelectric sensor, an air spring assembly, and a moving coil guiding assembly. The photoelectric sensor is arranged corresponding to the moving coil. The air spring assembly includes an upper air spring 2 and a lower air spring 3 respectively arranged on the upper and lower sides of the moving coil. The moving coil guiding system includes a guiding shaft and a guiding bearing, and dynamically adjusts the height of the moving coil through the air spring, and combines with the central zero position controller to achieve displacement and overload protection of the moving coil.

[0055] Exemplarily, the photoelectric sensor can monitor the position change of the moving coil in real time and accurately, and provide a high-precision displacement feedback signal. The central zero position controller can adjust the position of the moving coil in real time according to these signals to ensure that it is always in the balanced position of vibration, thereby improving the accuracy and stability of the vibration table. An air bearing 4 is provided at the bottom of the vibration table body 1, and is connected to the upper air spring 2 and the lower air spring 3 through pipelines for air supply.

[0056] During the operation of the electrodynamic vibration, the central zero position system can keep the moving coil always in the balanced position of vibration, that is, the zero position of vibration. The central zero position system instantaneously detects the position of the moving coil by a group of two photoelectric sensors, and feeds back the detection result to the central zero position system, so as to supplement or release air from the air spring under the moving coil. The function of the central zero position is to automatically adjust the air pressure of the air spring under the moving coil according to the load. The position control system consists of a double proximity sensor and a reflector. The photoelectric sensor provides a feedback loop for the position of the moving coil. The double proximity sensor is installed on the table body, and the reflector is installed on the moving coil. When the moving coil moves up and down, the shape of the reflection mark enables the two sensors to reflect different positions. The sensors used in the vibration table will determine the central position. During normal operation, the central zero position system will adjust the pressure of the air spring under the moving coil in real time according to the feedback information.

[0057] In some embodiments, referring to Figures 1 to 4 , the vibration table body 1 further includes a horizontal slide table switching mechanism 8, which is fixed by trunnions, air spring locking, and wall plate 6 screws, and is used for quickly switching between vertical and horizontal vibration modes.

[0058] Exemplarily, traditional vibration tables usually require complex mechanical adjustments or reassembly to switch between vertical and horizontal vibration modes, which is time-consuming and laborious. Trunnion air spring locking can provide high-precision positioning ability to ensure that the horizontal slide 12 can be accurately fixed at the required position during the switching process, reducing vibration deviation caused by inaccurate positioning. This greatly improves the usage efficiency of the equipment. The slide switching mechanism includes a center indicating scale 11, a horizontal limit switch 10, and a connector 9. The center indicating scale 11 is located on the side of the horizontal slide 12 of the vibration table and is used to detect the vibration position of the tabletop and determine whether the horizontal slide 12 is in the middle position. The horizontal limit switch 10 works through a mechanical triggering mechanism. When the detected object reaches the preset position, the mechanical structure in the switch is affected by an external force, and the contact is triggered, thereby generating a switch signal. The connector 9 is used for line connection with the vibration table body 1.

[0059] The vibration table body 1 can be connected to a hydrostatic bearing type horizontal slide 12 or a V-shaped track type horizontal slide 12 to meet the user's requirements for horizontal vibration tests. The horizontal slide 12 can be of an integral type or a split type. The split type horizontal table is also called an independent horizontal table. There is non-deformable granite as a hydrostatic support at the lower part of the horizontal slide plate. The vibration table body 1 is equipped with guiding trunnions and air springs. The air springs are arranged inside the trunnions, and the supply air pressure is 0.69 MPa. When the table body vibrates horizontally, the mechanical position of the table body can be adjusted by using four trunnion air springs. Locking screws 7 are configured on the trunnions. During the transportation of the equipment, the locking screws 7 can limit the free movement of the vibration table body. The four trunnion air springs have a vibration damping effect on the table body during the operation of the vibration equipment, allowing the table body to vibrate along the direction of the trunnion guiding shaft. The stiffness of the air springs is adjusted by the air pressure in the airbag, and the control valve is at the center zero position on the edge of the table body.

[0060] In some embodiments, referring to Figures 1 to 4 , the high-frequency vibration table further includes a single-point grounding system that eliminates ground loop interference through an independent grounding wire and is used to enable signal transmission between the power amplifier system and the vibration controller with an output waveform by using an isolation transformer.

[0061] Exemplarily, by eliminating ground loop interference, the single-point grounding system can significantly improve the purity and stability of the signal, reduce the influence of noise and interference on the vibration control signal, thereby improving the control accuracy and reliability of the vibration table. The isolation transformer can achieve electrical isolation between the power amplifier system and the vibration controller, preventing high-voltage or large-current signals from interfering with the control signal through the grounding path, thereby protecting the control equipment from damage. For the single-point grounding scheme, even if there is current flowing through the ground wire, the single-point grounding does not generate impedance for the circuits connected to this point. On the contrary, for a multi-point grounding system, potential differences may occur between different grounding points. The potential differences generated by multi-point grounding may be mixed in different instrument devices and control circuits and are difficult to distinguish.

[0062] In some embodiments, with reference to Figures 1 to 4 , the vibration table body 1 and the power amplifier are connected by a standardized cable, and the standardized cable includes a moving coil wire (O+, O-), an exciting wire (F+, F-), and an interlock protection wire.

[0063] Exemplarily, by separating the moving coil wire and the exciting wire, the mutual interference between signals can be reduced. The moving coil wire (O+, O-) is specifically used to transmit the drive signal, while the exciting wire (F+, F-) is used to provide the exciting current. This clear functional division can improve the quality and stability of signal transmission, reduce noise and interference. When a fault occurs in the system, the clear functional division makes it easier to troubleshoot. The operator can quickly locate the problem according to the function of the cable, whether it is a drive signal problem or an exciting current problem, thereby improving the fault handling efficiency.

[0064] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A high frequency vibration table, characterized in that: include: The vibration table body includes an excitation coil, a moving coil and an induction ring, wherein the moving coil vibrates through the interaction between the induction ring and the constant magnetic field generated by the excitation coil; The power amplifier system uses sinusoidal pulse width modulation technology to control the power switch to output amplified sinusoidal signals to drive the dynamic coil through the logic drive module; A cooling system is used to dissipate heat from the vibration table induction ring and power amplifier; The center zero position system is used to monitor the position of the moving coil and ensure that the moving coil is always in a vibration equilibrium position.

2. The high frequency vibration table according to claim 1, characterized in that: The vibration table body adopts an induction structure, the dynamic coil and the induction ring are connected by curing with high-temperature glue, the driving coil is fixed in the magnetic cylinder ring, and the alternating current is induced to the surface of the induction ring through the principle of a cylindrical transformer.

3. The high frequency vibration table according to claim 2, characterized in that: The power amplifier system comprises: Buffer module, used for anti-interference processing of input signals; Carrier generator module, generating a triangular wave signal with stable frequency; The pulse width modulation module combines the buffer output signal with the feedback signal and compares it with the triangular wave to generate a rectangular wave with adjustable duty cycle; The logic drive module performs branch delay processing on the PWM signal and adds synchronous pulse protection; The isolation buffer module is used to isolate the level of the signal sent by the logic drive part and perform voltage drive or current drive; The power switch module adopts a high-speed power semiconductor device with a full-bridge topology, and the output end is connected to an inductive load; A filtering module configured as a low-pass filter having a cut-off frequency lower than a carrier frequency; Voltage negative feedback loop to achieve deep voltage negative feedback.

4. The high frequency vibration table according to claim 3, characterized in that: The logic driver module comprises: The signal splitting unit divides the PWM signal into four driving signals; Delay control unit, set 0.1-2μs adjustable delay to prevent bridge arm from passing through; The synchronous pulse injection unit receives the pulse width limit signal to force the switching cycle to reset.

5. The high frequency vibration table according to claim 3, characterized in that: The frequency stability of the triangle wave generated by the carrier generator module is better than ±0.1%, and the linearity error is less than 1%; the power switch module includes a three-phase full-bridge rectifier unit, a DC bus capacitor group and four half-bridge power units, the input voltage of the three-phase full-bridge rectifier unit is 380VAC±10%, the DC bus capacitor groups are all equipped with equalizing resistors and discharge circuits, and each half bridge of the four half-bridge power units is equipped with an independent drive isolation circuit.

6. The high frequency vibration table according to claim 1, characterized in that: The cooling system includes a deionized water filtration system and a nozzle, which automatically triggers the spray when the driving current exceeds the set current value, and sprays the deionized water onto the surface of the induction ring to enhance heat dissipation.

7. The high frequency vibration table according to claim 1, characterized in that: The center zero position system includes a center zero position controller, a photoelectric sensor, an air spring assembly and a moving coil guide assembly. The photoelectric sensor is arranged corresponding to the moving coil. The air spring assembly includes an upper air spring and a lower air spring respectively arranged on the upper and lower sides of the moving coil; the moving coil guide system includes a guide shaft and a guide bearing, and dynamically adjusts the height of the moving coil through an air spring, and combines with the center zero position controller to realize displacement and overload protection of the moving coil.

8. The high frequency vibration table according to claim 1, characterized in that: The vibration table body also includes a horizontal slide switching mechanism, which is locked by a trunnion and an air spring and fixed by wall plate screws, and is used for rapid conversion between vertical and horizontal vibration modes.

9. The high frequency vibration table according to claim 1, characterized in that: It also includes a single-point grounding system, which eliminates ground loop interference through an independent grounding line and is used to enable the power amplifier system and the vibration controller of the output waveform to achieve signal transmission using an isolation transformer.

10. The high frequency vibration table according to claim 1, characterized in that: The vibration table body and the power amplifier are connected via a standardized cable, and the standardized cable includes a dynamic coil wire (O+, O-), an excitation wire (F+, F-) and an interlocking protection wire.

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