Adaptive ultrasonic cleaning machine

Volume 39, No. 5 Metal Products Adaptive Ultrasonic Cleaning Machine Wu Qiang, Kong Yu (Jiangsu Faershengyi Group Co., Ltd., Jiangyin, Jiangsu 214400, China) has adopted an adaptive ultrasonic cleaning machine specially used for wire and wire rope cleaning. The cleaning machine performs dynamic parameter tracking on the ultrasonic transducer, performs arithmetic processing according to the collected feedback voltage and current phase, and adjusts the output frequency of the ultrasonic power source to achieve a new dynamic matching resonance of the resonant inductor and the transducer. Practice shows that the output power of the adaptive ultrasonic cleaning machine reaches 96.8% of the rated power, and the cleaning effect is better.

Ultrasonic cleaning began in the early 1950s and has been widely used in modern industry with the advancement of technology.

In the production process of steel wire and steel wire rope, dust, grease, rust, etc. are often adhered to the surface, and these impurities are unfavorable for the subsequent processing of steel wire and steel wire rope. For wire ropes, ordinary cleaning is difficult to handle, but ultrasonic cleaning can easily solve this problem. When the ultrasonic cleaning equipment is used to clean the steel wire and the steel wire rope, as the working temperature of the ultrasonic transducer increases and the use time is prolonged, the parameters of the ultrasonic transducer will drift, causing the ultrasonic generator and the transducer parameters to be mismatched ( The output voltage and current signals are out of phase), the ultrasonic output power is attenuated, and the cleaning effect is affected. To this end, Jiangsu Faer Shengyu Group Co., Ltd. Engineering Equipment Center designed and manufactured an adaptive ultrasonic cleaning machine that can automatically track the parameters of the ultrasonic transducer, automatically adjust the ultrasonic resonance frequency, and regain the optimal output power.

1 Ultrasonic cleaning machine principle and advantages Ultrasonic frequency is higher than 20kHz, "sound waves that are not heard by human ears, mainly in the form of lateral oscillation and longitudinal oscillation. The transverse vibration can only be formed in solids, and the longitudinal vibration can be produced in solids, liquids and gases.

1.1 The main principle of ultrasonic cleaning is cavitation. The cavitation effect is that the ultrasonic wave transmits to the liquid at a high frequency conversion manner of a compression force of 20,000 times or more per second and a pressure reduction interaction. When the pressure is reduced, a vacuum nuclear bubble phenomenon occurs in the liquid; when the compression force acts, the vacuum core group bubble generates a strong impact force when crushed by the pressure, thereby peeling off the dirt on the surface of the object to be cleaned, thereby achieving cleaning. purpose. Ultrasonic cleaning cavitation is shown.

Straight inflow. The phenomenon in which ultrasonic waves flow in the direction of sound propagation in a liquid is called a straight forward flow. The intensity of the sound waves is at. At 5W/cm2, the naked eye can see that the straight flow flows perpendicularly to the vibrating surface, and the flow rate is about 10 cm/s. This straight flow causes the oil on the surface of the object to be cleaned to be stirred, and the cleaning liquid on the surface of the dirt also convects and dissolves. The dissolved solution of the dirt is mixed with the new liquid to accelerate the dissolution rate.

Acceleration. Acceleration is generated by the pushing of liquid particles.

Ft can l>SI stretch circuit W can clamp the center ultrasonic cleaning cavitation diagram for the higher frequency ultrasonic cleaning machine, its cavitation is not significant, then the cleaning mainly relies on the liquid particles under the action of ultrasound The particles are impinged to clean the dirt. This acceleration is 103 times the gravity acceleration at 28 kHz and 105 times the gravity acceleration at 950 kHz, but the 950 kHz ultrasonic wave does not produce cavitation, and is not suitable for ultrasonic cleaning of steel wire and wire rope.

1.2 Ultrasonic cleaning advantages Ultrasonic cleaning effect is good, cleanliness is high, cleaning speed is fast, no need to touch the cleaning agent by hand, safe and reliable, can also clean the gap, concave and convex surface, deep hole, no damage to the surface of the workpiece, save heat, Cleaning agents, sites and labor. Especially for mechanical parts with complicated surface, uneven surface, blind holes, wire rope, special-shaped steel wire, etc., ultrasonic cleaning can achieve better results. Ultrasonic cleaning has shown tremendous advantages and will gradually replace traditional cleaning methods.

2 Principle and composition of adaptive ultrasonic cleaning machine 2.1 Principle of adaptive ultrasonic cleaning machine The ordinary ultrasonic cleaning machine is composed of ultrasonic generator, ultrasonic transducer and ultrasonic cleaning tank. The ultrasonic generator converts the power frequency alternating current into high frequency (20~25 kHz) alternating current and transmits it to the ultrasonic transducer through the impedance matching inductor; the ultrasonic transducer converts the ultrasonic energy into high frequency mechanical vibration and is transmitted into the cleaning liquid. The cavitation is generated in the cleaning liquid to achieve the purpose of ultrasonic cleaning.

The key of the adaptive ultrasonic cleaning machine is to track the parameters of the ultrasonic transducer. The change of the parameters of the ultrasonic transducer is reflected in the dynamic capacitive reactance of the ultrasonic transducer, so that the impedance matching inductance and the dynamic capacitive reactance of the ultrasonic transducer do not occur. Complete resonance, which is reflected in the electrical performance as a phase shift between voltage and current. As long as the phase relationship between the voltage and the current signal can be captured in real time, the adaptive tracking of the ultrasonic cleaning machine can be achieved.

2.2 Ultrasonic Generator Structure Ultrasonic generator, also known as ultrasonic power supply, is a device that generates and supplies ultrasonic energy to the transducer. In the cleaning of steel wire and wire rope, the power of the ultrasonic generator is required to be large, generally more than 1.5 kW. Therefore, the half-bridge inverter type power supply ultrasonic generator is used, and its structural block diagram is as shown, and the appearance is as shown.

The wave-generating frame intelligent control center uses Texas Instruments' TMS320LF2407A processor. The processor is a feature-enhanced low-power and high-performance chip specifically designed for industrial control, controlled by a single-chip DSP provided by a digital motor. The chip has high data computing power and powerful PWM control performance, and is fully qualified for intelligent control.

The voltage sampling can directly acquire the PWM signal of the digital PWM circuit as the voltage phase; the current sampling uses the AllegroMicrosystems Hall circuit sensor, which has fast response, good linearity and high stability. It can be considered that the phase of the output voltage signal of the current sensor is actual. Current phase.

The intelligent control center collects the voltage and current phases for arithmetic processing, and obtains a PWM signal of a suitable frequency to the digital PWM circuit, and processes it to provide a driving circuit for the IGBT in the half-bridge inverter circuit to drive the IGBT. The isolation transformer in the IGBT and the inverter circuit converts the rectified DC power into an AC frequency of 20 ~ 25 kHz, so that the resonant inductor and the ultrasonic transducer resonate, thereby generating ultrasonic energy.

There are two types of transducers for ultrasonic cleaning. One is a magnetostrictive transducer for metal products, and the other is a piezoelectric ceramic transducer. Magnetostrictive transducers are rarely used because of their high cost and complicated manufacturing process. There is also a magnetostrictive transducer made of a ferrite material which has low mechanical strength and can withstand a small electric power capacity, and thus is rarely used in China. China mainly uses piezoelectric ceramic transducers, which have high electro-acoustic conversion efficiency, low raw material prices, and easy to manufacture different structures to meet different cleaning requirements. There are many types of piezoelectric ceramic transducers, such as cylindrical, horn, and the like. After comparison, it was finally determined that the horn-shaped sandwich piezoelectric ceramic transducer was selected as the adaptive ultrasonic cleaning machine transducer.

The electric power of the radiant panel with the transducer is generally less than 1~2W/cm2, and the piezoelectric ceramic transducer is generally 0.5~1W/cm2. The excessive strength will accelerate the cavitation corrosion on the surface of the radiant panel. Damage to the radiant panel. In order to improve the service life of the transducer, the radiant panel is made of 316L stainless steel and the surface is chrome-plated. To use cavitation corrosion on the surface of the ultrasonic transducer for 2 and a half years.

The actual use of the ultrasonic transducer for 2 years and a half is the actual use of the ultrasonic cleaning machine in the ultrasonic cleaning process of the wire rope. The stains and oil stains in the wire rope are sprayed by the cavitation effect of the ultrasonic wave, and the cleaning is carried out. The effect is better.

The actual cleaning effect of the wire rope 4 Conclusion The adaptive ultrasonic cleaning machine designed and manufactured by the Engineering Equipment Center of Jiangsu Faershengyi Group Co., Ltd. has been successfully applied to the S-type steel wire ultrasonic cleaning production line for the main cable of the suspension bridge. The cleaning machine and the ordinary ultrasonic cleaning machine are compared after two and a half years respectively. The output power of the ordinary ultrasonic cleaning machine is only about 70% of the rated power, and the output power of the adaptive ultrasonic cleaning machine is about 96.8% of the rated power. better.

Basic Roller Blinds Fabric

Flame retardant waterproof fiberglass and PVC Curtain Fabric
The Outstanding features for Curtain Fabric :
100% Opaque
Waterproof & Dampproof
Fire Retardant
Anti- UV
No Formaldehyde
Anti-mildew
Environmental
Winkle free
Self-clean
Durable

Antimicrobia