<title>Novel horn designs for ultrasonic/sonic cleaning, welding, soldering, cutting, and drilling</title>

Abstract

A variety of Industrial applications exist where power ultrasonic elements such as the ultrasonic horn are used. These included the Automotive, Instruments, Foods, Medical, Textiles and Material Joining and Fabrication Industries. In many of these devices the ultrasonic horn is the key component. The standard transducer used in these devices consists of three main parts, the backing, the piezoelectric elements and the horn. Standard horn designs have changed very little since their inception. There are four common types of standard horns. They are; constant, linear, exponential and stepped, which refer to the degree to which the area changes from the base to the tip. A magnification in the strain occurs in the horn that in general is a function of the ratio of diameters. In addition the device is generally driven at resonance to further amplify the strain. The resonance amplification is in general determined by the mechanical Q (attenuation) of the horn material and radiation damping. The horn length primarily determines the resonance frequency. For a 22 kHz resonance frequency a stepped horn of titanium has a length of approximately 8 cm. Although these standard horns are found in many current industrial designs they suffer from some key limitations. In many applications it would be useful to reduce the resonance frequency however this would require device lengths of the order of fractions of meters which may be impractical. In addition, manufacturing a horn requires the turning down of the stock material (eg. Titanium) from the larger outer diameter to the horn tip diameter, which is both time consuming and wasteful. In this paper we will present a variety of novel horn designs, which overcome some of the limitations discussed above. One particular design that has been found to overcome these limitations is the folded horn. In this design the horn elements are folded which reduce the overall length of the resonator (physical length) but maintain or increase the acoustic length. In addition initial experiments indicate that the tip displacement can be further adjusted by phasing the bending displacements and the extensional displacements. The experimental results for a variety of these and other novel horn designs will be presented and compared to the results predicted by theory.

A Parametric Study for the Design of an Optimized Ultrasonic Percussive Planetary Drill Tool

“…For this purpose, the supplied AC voltage in experiments was measured by a GE 8115 differential probe at the piezoceramic rings to determine a relationship with horn displacement. As stated in [16], for the horn ratio of base diameter to tip diameter, the amplitude gain can be calculated from the parameters in TABLE I to be 7.42. As a verification, the gain of the tapered horn in the experiment can be calculated from Fig.…”

Design and analysis of ultrasonic actuator in consideration of length reduction for a USDC (ultrasonic/sonic driller/corer)

“…The planar folded horn evolved from the folded horn [Sherrit et al, 2002]. Figure 8 shows a Solidworks drawing of the horn.…”

“…A commercially available code ANSYS was used to perform the finite element modal and harmonic analysis. Two novel designs of ultrasonic actuator [Sherrit et al, 2002] , shown in Figure 3 and 4, respectively. In order to study the performance of the new horn designs we first performed modal analysis on the two actuators to derive the resonance frequencies of the designed operating mode.…”

“…It is desirable to have designs that reduce the length of the device. Quite a few novel designs of the ultrasonic horn for USDC have been proposed [Sherrit et al, 2002], aiming at reducing the length of the ultrasonic horn. In this paper, a series of analysis of these novel ultrasonic horn designs have been carried out to provide the basis for an optimal design and better understanding of these ultrasonic horns.…”

Novel horn designs for power ultrasonics

“…Upon closer inspection of this folded horn design it was determined that the screw threads connecting the base plate of the horn to the outer walls of the horn were the likely source of the increased dissipation of energy and reduction of resonance. Another design without screw threads that can be manufactured quite easily, which we intend to investigate was reported earlier [7].…”