DE1622880A1 - Sound transmission line - Google Patents

Description

Please state in the answer -Our reference

O / p 6074

THE OHIO STATE UNIVERSITY, North High Street, Columbus ;, Ohio, USA

Sound transmission line

The invention relates to electromechanical converters a high Q-value and an improved structural training V. which can achieve extremely high output. Present Registration represents a further development of the subject of patent application 0 12'619 lXa / 42B (uneere file 5075). Theoretical data are different from actual data Load conditions in the transmission of TJItrasonic energy related via "long transmission lines of different wavelengths.;

An electrotnechaniacher 'vfendler, e.g. a piezoelectric · * means may include electrical pulses of high frequency mechanical sch · pulses of high frequency or convert vice versa. If the piezoelectric elements are supplied with an input voltage with alternating

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- ■; ι ■ ■

Polarity abandoned, created. The transducer transmits and amplifies a series of mechanical pressure waves in the piezoelectric Material and in the metallic carrier assembly. Looking at the converter alone, a sequence of identical compression and attenuation waves transmitted in a transducer of suitable length, a standing wave.

In the case of a straight rod, 'the maxima' and minima 'correspond represent the standing wave positions of maximum and minimum speed, minimum and maximum stress and maximum and minimum

ler / displacement on the transducer body. These places lay optimal Make "gradations" or changes for support points fixed in diameter, tools or mechanical couplings, etc. The nodal points on the transducer correspond to points of minimal axial displacement and speed, the abdominal areas correspond to points of maximum axial displacement and speed or movement. The one on the transducer between neighboring The distance measured in antinodes is equal to half a distance Wavelength at the fundamental resonance frequency, where the length of depends on the shape and can be changed with it »

In the patent application O 12 622 IXa / 42s (our file 5072) is a Schail converter described and shown, which the drive element (piezoelectric element) with the mechanical displacement amplifier (Horn) combined in a new way. This is essentially a resonance arrangement that is excited in its interior near the vibration node. the Arousal is in contrast to the external excitement which is usual ' is when horns are used in a transducer system.

- .--: ■ -.:_ ;: ./'_■'■ =. ■ "■■ ■■" · ■ - ■ BAD

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The converter has a high Q value, which is high performance exceptionally robust, compact and can withstand continuous work loads. .

In the case of patent application 0 12 619 IXa / 42s (our file .5075) a motor generator is described and illustrated that is not based on the utilization of the force generated is directed as workpiece loading is. This generator is based on the transmission of high performance energy directed from one place to another with a high power factor. In this application, the engine genes rator two transducers that are coupled to the tips of their horns' are. In a relatively short overall length, the two transducers and the transmission line connecting them must be a multiple half a wavelength for maximum energy transfer be. In the simplest embodiment, a resonance transmission line is used half wavelength inserted between two transducers. This creates a node with a longitudinal displacement generated by the ITuIl value in the middle between the converters.

With "another application 0 12 943 IX / 42s of the applicant (our file 6073) is a device for transducers aur effective coupling of the aforementioned electro-mechanical converter high Q-value and high power to effectively drive a tool, i.e. to drive the tool in a workpiece environment. The transducer horn transmission line is coupled directly to the workpiece surface *

The main aim of the present invention is to provide an electromechanical Converter and a transmission line for delivering high power to a workshop speed with only minimal

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To create frequency change in the converter system.

Another object of the invention is to provide a transmission line more predetermined Length to create the power output to a workpiece boundary surface a converter with a high Q value with a constant frequency power feed brings it to the maximum.

The aim of the invention is also to provide a transmission line with To create a given length and also a method and a Device for coupling the transmission line to a workpiece interface to indicate high power acoustic energy with only a minimum of resonance frequency change in the transducer system.

The present invention relates to a device for delivering high power acoustic energy to a workpiece surface. There are rigid transmission lines of standing wave with them changing lengths used. In particular, it is a high performance, high Q converter with a prolonged transmission coupled directly to the workpiece surface at an angle. the Resonances from longer transmission lines are reduced (Δ F) by increasing changes in the line length (Δ L) than shorter ones Transmission lines affected. The resonance frequency of the transducer (plus transmission line) sets the desired frequency the energy supply for maximum power transfer The Q value of the transducer (plus transmission line) increases but on when the line becomes longer. A higher Q value results increased sensitivity to changes in the resonant frequency for maximum power transmission. the

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Relationship between Δ Ρ / Δ L decrease in sensitivity and Q value « Increase in sensitivity for longer lines indicates that the A slot reinforcement for transmission lines that are not loaded reduced frequency sensitivity up to 3 or 5 1/2 waves « lengths result.

The present invention proposes a device that has a extended transmission line for an electromechanical Has converter that is coupled at an angle to the load connection. pelt is. A high-performance converter can be used with a workpiece « surface with only a minimum of. Resonance frequency change (as compared to a half wavelength transmission line). The maximum acoustic power can also be emitted are used by using a constant frequency feed using a high Q transducer as a sound driving device used when a long transmission line is provided.

data are also given to indicate improvements in the transmission line to achieve independently of the connection device with the workpiece surface. That is, improvements achieved in the frequency sensitivity to load changes have been, e.g. against changes in the load coupling the Laet Grenzflache and in the changes of the load characteristics; this will improve the ability of the sound transducer for delivering high energy to a workpiece boundary surface with only achieved a minimal change in converter frequency. Interpretations in the transmission line in itself increase the percentage of theoretical performance of a converter with a high Q value, on a unit area with a constant frequency power

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feed, dji. should be transmitted with increased effectiveness, to a maximum.

The invention is described below in conjunction with the drawing explained on the basis of exemplary embodiments. They show figures:

Pig. 1 is a simple schematic representation of the sound transducer together with a transmission line,

Pig. 2 a thematic representation of the sound transmission line with a given up strength,

Pig. 3 is another schematic representation of the transmission line vibrating with the lowest vibration,

Pig. 4 is a graph showing the resonance frequencies as a function of the absolute length of the transmission line,

Pig. 5 is a schematic representation of a transmission line with an applied pressure,

Pig. 6 in the form of a table is a schematic representation of FIG Boundary conditions according to the various simple Charges,

Pig. 7 is a graphical representation of the roots of the equation Heat A> ali / α,

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8 another graphical representation of the roots of Tan JI + (id Sl ) / M + 0,

9 is another graphical representation of various values of

Fig.10 is a schematic representation of a practical embodiment as it is used to obtain the data; became. - ■ - "- ■■ ν -.; .--

The configuration of the arrangement _f made up of a converter and a transmission line is shown in FIG. The combined vibrations of the arrangement shown are achieved * that the vibrations of the transducer and the line tend to decouple so that the transducer acts as an energy source attached to one end of the line. In practice this is realized when the system operates at or near the resonance frequency of the free transmission line.

The transmission lines are massive steel rods changing Length. Since these lines have a very high ratio of L / d are characterized acoustically as thin rods. Investigation of the influence of increasing length of the transmission line as far as it is the vibration »resonance frequency of the System concerns is not related to the power transfer properties related to these frequencies. She's only on that Related to resonance frequencies that are to be expected from a free and unclamped thin rod * changes in the Resonance frequency that occur in the transmission lines with changing lengths, which are due to the same incremental components

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the change in length are a measure of the sensitivity to resonance. The resonance resistance is related to the power transmission properties of a sound energy system due to the "special qualities of the above-mentioned high Q value converter. The long transmission line is less influenced by increases in changes in length" than shorter lines.

The analysis of the longitudinal vibration properties of a simple rod, like in Pig. 2 is the following »Bs is the basic transmission line with a length of 1 and an " put force ρ (t). shown at the point X = O.

The equation corresponding to the simple longitudinal vibrations of the Is based on the following:

2 u 1 2 -α . / ίλ

2 2 ο .2 \ ^x )

χ "coordinate of the rod cross-section u m displacement of the rod portion, t = time

c »■ Vi; / p - speed of the longitudinal acoustic waves, E = YoungJ modulus of elasticity,

p β the mass final density / volume *

In Pig. 3 shows a rod vibrating with the lowest visual waveform. The arrow represents the direction of movement, the amplitude is given by u , 1 is the rod length.

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The resonance frequencies of a free-swinging transmission line is determined by solving equation (1), which is subject to corresponding boundary conditions. In the present Trap are the conditions

* ο, χ «o, 1 (2.)

One takes a solution of the form

u β χ sin wt. (3)

and if you put it in (1), the result is the usual one Differential equation

X «+ - ^ X = ο (4)

which is the solution. "· .'- ..

X «A sin - χ + B cos - χ (5)

C C · 'V-.

Has. If one introduces the boundary conditions, the equation results

(2) B »ο and gives the basic equation for the resonance frequencies of the transmission line

where f is the resonance frequency in periods per second «

As can be seen from equation (6), a rod has a given physical properties (fixed values of E and ρ as well as Lengths 1) an unlimited number of resonance frequencies that lowest is given by η ■ 1, and they increase with integral multiples of this value. The shift of a

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any point in the member is indicated by

u = A sin (w _n x / c) sin w _n t) (7)

determined, where w »2 3Tf -. - '

η η

For the Pail η = 1, the rod oscillates in the one shown in FIG. 3 Shape. This shape is the "half-wave length" representation. For η = * 2, 3, 4. · .. additional half wavelengths are added.

For steel, Ε / ρ β 51.8 χ 10, ■ · * cm / sec, so that f _{n is} «10.2χ 1O ₃ ⁴ -γ Hz.

For example, if 1 = 12.5 cm, the lowest vibration _{frequency of this length is f 1} · 20.4 kHz and in this case f ₂ = 40.8 kHz. Fällst = 50 cm, Γ _χ = 5 _t 1 kHz and f _g * 10.2 kHz etc. From this a table can easily be given (Table I of the Appendix) which shows a number of resonance frequencies for lines of different lengths In Table I, Jt refers to the length of the line, ^, refers to a wavelength at 20.4 kHz (e.g. 25 cm) and serves as a reference length for the other lengths, e.g. 50 cm, 87.5 cm etc. *

In order to bring the theoretical deductions into agreement with experimental results , a series of tests was carried out in which the transmission lines were 12.5 cm (1 / 2X at 20.4 kHz), 25 ob, 37.5 cm, 50 cn, 75 cm, 87.5 cm and 100 om by a transducer, such as those described in the patent application -vorerwähnten were vibrated. In each case the frequency range from 9 kHz to 40 kHz was swept over- .. and the resonance frequencies of the system became duroh

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Measurement of the converter power level determined · In Jig. 4 are the ResxLÜate summarized in a graphic lOrm. The '-theoretical Values that are tabulated in Table 1 are also in comparison with the results from the test series in Pig. 4 shown. The agreement between the experimental and the theoretical, values were relatively good. However, a range of values in the range of 20-25 kHz was by theory not to explain. '

An additional experiment was carried out on the converter alone to determine its separate resonance frequencies. The piping was at 23, 24, 25, 24, 8 and 25.8 kHz. These results showed that the series of inexplicable resonance frequencies actually through the converter and not caused by the line.

In connection with Table II of the appendix it is shown that the value Q of the transducer plus transmission line increases as the line becomes longer. Since the resonance frequency of the transducer represents the desired frequency of the power supply for the energy transmission, a higher Q value results in an increased sensitivity of the resonance frequency. The assumption of the ZVf / £ ± ! Sensitivity and the increase in the ^ sensitivity shows that the long, unloaded transmission lines result in a usable gain of up to 3 or 3 1/2 times the wavelength.

In connection with! Table III of the appendix the point is shown, in which a comparison with a half-wavelength line shows the greatest improvement. The table gives approximate data (averaged from understanding) showing the total frequency sensitivity

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transmission lines of half a wavelength Refer to cables with multiple wavelengths ".

A series of experiments with transmission lines were carried out by «· at which the change in resonance frequency caused by small changes in the line length was measured became. The results of these experiments with various different Transmission lines are shown in FIG.

If a transmission line originally had a length of 101.875 cm, by increments of 0.5 cm to one Length of 98.4375 cm is shortened, it can be seen that the Resonance frequency 'increases somewhat. The shorter line that originally Was 13.4375 cm and was shortened to 10.9375 cm shows a more pronounced increase in frequency. The change in the Frequency caused by these identical changes in length is a measure of the line's sensitivity to resonance.

The area covered by the experimental data is roughly the area enclosed by the narrow strips of FIG. It therefore follows that the experimental tests essentially agree with the theoretical statements.

The equation for the expected frequency shift for a given change in the line length can be derived. From equation (6) we get

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f _n -l = - | j—. yE / p ~ where> £ S = ^ ₁

^f n ² "'· \ / ^E / P' ■ where / Cw

(n / 2) ΥΪ6 (9)

■■ - ■■ .- 12

A corresponding expression for equation (9) results, if 1. * - 1_ »Δ.1 is made and if it is taken into account,

¹ <2

that for small Δ1 1-, "1" becomes, so that I ₁ . I ₂ * 1. then

From the equation / it follows that

(1) the change in frequency Δί for large values of ^
0-longer lines) becomes smaller at any frequency,

(2) the frequency change Δ f for higher waveforms (higher harmonics) (i.e. capital n) for any Lei " length increases.

Both observations can be made from the experimental results 5, although the second influence is slight remain. The agreement between theoretical and experimental results is relatively good for the longer ones Lines, as shown in the calculations in Table II (Appendix) en.

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Table II (Appendix) shows that the Q value of the transducer is plus Transmission line increases as the line becomes longer.

Ba the resonance frequency of the transducer the desired frequency of the Represents energy feed for energy transmission, there a higher Q value an increased sensitivity of the resonance frequency at. The A f / Δ L sensitivity decrease and the Q sensitivity increase indicates that the long, unloaded transmission lines have a useful gain up to 3 or 3 1/2 times the wavelength.

In Table III the point is given at which a comparison has the greatest improvement with a half-wavelength line. The table gives approximate data (determined from experiments) which relate to the overall frequency sensitivity ability of half-wavelength transmission lines up to practicing Obtain transmission lines with multiple wavelengths.

Furthermore, in continuation of the above experiments, the sensitivity of unloaded transmission lines to changes in length was investigated examined. The resonance sensitivity of ultrasonic transmission lines there is an essential factor influencing their effectiveness against various types of stress.

One of the main considerations in effectively transferring Ultra-echo energy from a transducer over a transmission line and In a load is the degree to which the transmission line is "out of tune" by the load. This . ' Effect occurs when there is a shift in the resonance frequency the transmission line occurs due to the nature of the

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Load and / or due to the device * through which the line and the load are coupled. The following are different types of loads consisting of combinations of Spring, mass and viscous damping system considered.

In Pig. 5 is a transmission line of length L to which a pressure ρ (t) is exerted at χ = O and with a load when x = L is coupled, it is shown »The regularities for this problem are already given in equation (1). Takes to find a solution in jorm of \

U = X (X | I; (t) '(11)

on, it can be shown that -

iwt u = (C sin wx / c. + D cos wx / c) e (12)

the basic differential equation is sufficient. . ν *.

To introduce the constants into the above solution, the required boundary conditions are listed. For the end, on that “the pressure ρ (t) is exerted is the condition

χ = o, E du // d x = poe ^iWt (15)

the case of a 'simple harmonic burden' has been considered. Then \; iri 'rXotohimg; (2) changed to

P _Q c it

u * (—- sin wx / c + D cos wx / c) e ^W (14)

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The type of load is determined by the limit condition he χ * 1. The various final states, which are created by simple combinations of a spring, a mass and a buffer, are in Pig. 6 of the drawing, as well as the corresponding mathematical expression of the state. -

Example. 7 in Pig. 6, which is a combined peder mass buffer system can be used to achieve Examples 1-6 by taking k, m, η corresponding limit values, e.g. JIuIl or infinite. To realize example 1, will msxn = k = o in Pail 7, while example 2 is achieved by that in example 7 m = n = o and k - * »is made.

To obtain a general solution, the limit condition which corresponds to Example 7 is inserted into the equation (14) and the constant D "is determined. The resulting expression is

us - (sin wx / c + E ₁ A ₂ cos wx / c) e ^τ (15)

where A is the cross-sectional area and D and DqD ₂ are defined in the following way:

D ₁ - - == cos wL / e - (raw - & Α - in) sin wL / c

D ₀ * -— sin wl / ^e + ( ^mw - Vw "· ⁱⁿ ) cos w (17)

This solution establishes the response of the transmission line an applied pressure when the line with different is coupled to simple loads.

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The case of a transmission line operating in resonance mode is obtained when the expression D ₂ * 0 in equation (15) ) to be determined. It can be shown in a simple way that D _p »0 is the frequency equation which is the natural vibration frequencies: ddr different loaded transmission lines.

Although it is possible to trace the roots of the frequency derivation (17) for different values of the parameters k, m, η would be determined It can be difficult to interpret the results due to the variety of parameters causing the result. It'll be a better one Get insight into the basic principle by having different special cases are considered, namely:

(1) Free end j it is chosen ms «k» n »o in equation (17)» whereby results>

sin w L / c st ο, wn "« η '* (o / L), (η = 1, 2, 31 .....) (18)

(2) End of hitched tea? we put m ^ neo, k- * ⁰ ^ in equation (17), which gives see

cms WL / ö «o, W _n * (n1f / 2) o / li _f (n * 1, 3, 5 .......) (19)

These two solutions represent the known solutions for dit Eigen / frequencies of rods with two free ends and rods with a free and a solid Eride. The first case in which the stress influences are taken into account, is that of a simple one Feather. *

, BATH

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(3) pederia load; it is set m = n == o in the equation (17),. where results

Tan w L / c - kc / EA (20)

Defining Q and a as

G = wL / c, K = aAE (21)

so equation (20) can be expressed as follows:

Tanß = al / tf (22)

The general behavior of the roots in relation to this equation for different values of a1 is shown in FIG. From this Figure results in the following interpretations:

(1) If al is small (e.g. 1/2, 1), then the roots of the equation are for example η if (n «1, 2, e, ......). This corresponds to the case

a rail with a free end, which is roughly the case for a weak pen *

The case of the lowest root, which results from the intersection with the first branch tan Q. , corresponds to the natural frequency of the rod and the spring as a "FedeaHUasse" system.

(ii) If one enlarges al (eg 5 »6, 7)» then the roots tend towards the values nif / 2 (n «1, 3» 5, .... ·) » ^w & ^s corresponds to the stick with rigid elite . Thus, an increase in the stiffness of the spring causes the load to act more and more like a rigid beam.

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(iii) However, the tendency of the roots mentioned in (ii) is very slow because of the asymptotic approach of. aL / ß against ITuIl for large values of ■ & ■ * S omit for large & according to the intersections that occur with the branches tan £ 2 in some distance from the origin, the roots tend to see stretching from (i) (ie a / lien) instead of (ii) approach. This is of essential importance in the present invention, since a ultrasonic transmission line operating in a frequency range of 10-25 MIz. with higher vibration "would be operated.

As a result, it can be concluded that even for stiff load loads, the transmission line's resonance only to a small extent would be "influenced by the Fed until eleven.

(4) Mass load one sets k = u = o in equation (17) * from which see results:

Tan MfJj / c = -mwc / EA (23)

If you define £ as before and set M = pAl, which corresponds to the total mass of the transmission line, this equation becomes

Tan δ + (τη / Μ} Ω = ο (24)

The "behavior of the roots of this equation for different values of the parameter td / M is in Flg. 8 shown. See what happens from this the following remarks:

(i) Eür an assigned dimension relief, which is large in comparison to the line earth .. (z »B- m / M / = ■ 3 or 4) are the roots

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So

of equation (24.) about nf / 2 (n,. «= 1, 3, ....-) ,. according to the Pail of a rod that is restrained at χ = L. Thus effected. a large mass load that the system behaves like a restrained end system.

(ii) Pure. very small mass loads (e.g. m / M = 1/8) are the

Roots about η if (n = 1, 2,). corresponding to the staff with free

End. However, if one takes into account the linear increase in m ^ / M, it follows that the intersection of these straight lines with the higher branches of the Tan ^ c curve is approximately at n ^ / 2 (n = 1, 3 ». ·.] - as indicated in (i) above. This means that the resonance of a transmission line is quite heavily dependent on the mass load, especially at higher waveforms and the fifteenth mode vibrates and a small mass load is added, the resonance frequency may drop quite sharply.

(iii) An additional note on the results of the equation (24) seems appropriate, since a brief consideration is obvious In contrast to the information in the Appendix, Table I with regard to the frequency properties of the transmission lines. For example, it appears from FIG. 8 that an increase in the line length (thus an increase of M of the ratio m / M) intends to increase the frequency, a result which is opposite to the result presumed in the Appendix, Table I. However, it can be explained in more detail show that this is not the case:

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(a) For fixed line lengths - Ii is the value M of the equation (24) constant. The results of the Jig. 8 show for decreasing Mass loading τη that the frequency w that is in the frequency parameter

Q is included trying to enlarge.

(b) Now m is regarded as a fixed value and the line length is increased. Thus the ratio m / M decreases, whereby the value of the root i? is enlarged. However, this has not increased the frequency w of the system since, expressed according to 52, w = 52 c / L. Thus, the increased value of Q is counteracted by the increased value of L, thereby obtaining a useful reduction in the frequency of the system. In reality this was it. apparent contradiction the result of the choice of frequency and mass ratio parameters, both of which contain the common parameter L.

(5) viscous load; this case occurs when k = m = o in

of the equation (15) where the following then applies:

- (25)

Pc

ο,. / .. ": (EA / c) cos wL / c + insin wL / c, _Λ iwt u = ^ - (sm wx / c + ■ -., Ι, - cos wx / oje

w (EA / c) sinwl / c - i cos wL / c

The presence of a viscous damping as iat contained in the above expressions, prevents the unlimited response, dae to the characterization of a resonance state in the preceding cases, was used. However, with a slight manipulation, equation (25) can be converted into the following form

u ~ —ρ (sin wx / c + De ^ COS wx / c) e (26)

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where: '■

t - ,, 2 ^ 2, .2 2.2 2 '/ -. 2 * ', "" _Λ 2 2 2, 211/2 _ L (AE / c -n) cos wL / c sm wL / c. + A η E./c J ^x

2 2 2 * 2 2 2 (A E / c) sin wL / c + ■ η cos wL / c

m - AnE / c ".." '"/ r, rt \

Tan o-fe ■ - 2> (28)

(A E / c -n.) Cos wl / c ■

In determining the maximum system response corresponding to the resonance of the damped system, it is sufficient to determine the change in the coefficient D as given by equation (27). Define, Q as before and place

ή = e _n / AE (29)

so equation (27) becomes

f -2 2 2 2 -2 "\ 1/2

L (I-HL) cos Q sin 5? - -t- η J ' - , ._.

sin S2 + η. cos

The general shape of this curve for various values of η is in Pig. 9 shown. Although a complete consideration of the system response under viscous loading should also result in the phase shift given by equation (24), the general conclusion can be drawn from equation (28) that the influence of viscous loading on the reduction of the value Q of the system, as indicated by the decreased values of D for different values of n ^ o. This effect should of course be expected ahead of time, but it is interesting to note how the high Q transmission line tends to it is affected by the addition of an isolated, viscous damping device. . ^ _ ^ ''. "'"'"■■'' ■. ■ - BATHROOM

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In conjunction with FIG. 10, there is shown the motor generator which is shown in FIG the patent application 0 12 619 lXa / 42s (our file 5075) and is shown. In Fig. 10a there is the transducer transmission line coupled with the workpiece environment, as described, for example, in patent application 0 12 943 IXa / 42s- {our file 6073) " and is shown, together with the "long" Transmission line of Fig. "XOb present goal blow.

In the earlier patent application 0 12 622 IXa / 4-2 s (our file

5072) was expressed that "at reasonably short Total length of the two transducers plus the transmission line connecting them multiples of half a wavelength for maximum Be energy transfer. In the simplest embodiment, a resonance transmission line is used with half the wavelength

used between two converters. This results in a junction— place or a place of longitudinal displacement, of the value 0 in the middle between the transducers. In transmission lines that longer than two to three wavelengths, energy will be lesser Frequency sensitivity to changes in the load characteristics than transmitted in shorter lines.

From the above analysis and * »the above data it can be seen that present improvements are a continuation of the original results of this application. It should also be noted that in the above application only one motor-generator set as shown in Fig. 10 is used. This sentence represents an acoustic adapted device 11 and 13, which is attached to a transmission line 16 at one of the two ends. Furthermore the motor-generator set represents a special housing in

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which is a resonance system consisting of two identical transducers and the transmission line is loaded with an electrical load (on the generator) without disturbing the acoustic system can be.

This is in contrast to unloaded lines and lines with various unmatched loads that are described above

stands
and / and also in contrast to the usual method of expedient loading, in which the acoustic properties of the loading are completely different from the driving transducer. For example, in the preferred embodiment, the load 15 applied to one end of the transmission line 12 to Pig. 10a is connected, represents a shell or plate,

ResistanceB-

which slides or shifts in or on an M or viscous workpiece surface or a corresponding medium. In this case, effective changes are present in the coupling with the workpiece surface, and there are effective And e conclusions in the acoustic separation, Trägheita- and suspension characteristics of the load as seen from the transducer. These changes occur randomly, continuously, and over a wide range in the normal course of events.

Furthermore, the influence of inertia and Spring resistance changes in the load on the transmission line and on the frequency and type of services driving converter can have. An increase in the mass in the load significantly reduces the frequency requirements; unite Increasing the spring resistance greatly affects the frequency strong. Neither the mass nor the suspension resistance put in itself represents a sound separation load (resistance load),

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may th ie a burden that work LELs. The change in the

Jumping

actual workload (• 5 * e «» load) is in IOrm der Change of value Q shown.

In a complete analysis of the transmission lines of the preferred embodiment according to the present invention, in the case of use in a - work environment (e.g. in the -in patent application 0 12 943 IXa / 4-23- (our file 6073} _r ie an angular contact with a shell or plate) created a theoretical basis that is corroborated by experimental knowledge.

The increased line length reduces the need for ^ f (or the change in the resonant frequency of the drive device) within the changes in the load and / or load coupling. This effect is intensified and deepened when there are acoustic separating loads (resistance loads), ie those where useful work is achieved. Under these conditions, the transmission lines having a length of ^v three to four wavelengths optimum.

With regard to the changes in the spring properties (spring resistance) of the load (or of the tool) that occur with the end of the Transmission line is connected, the spring resistance is at the change in the resonance frequency requirement in systems with nietigem Spring resistance less effective than in systems with high Moisture resistance. This characteristic supports the practical application, as shown in Fig. 10a, that a resilient thin plate or shell at a steep angle with less Change in the resonance frequency compared to a right angle taking place drive can be driven. The bigger change is considered as a change in suspension resistance, i.e. lower suspension resistance; · In connection with a steep angle.

009 8ί2 / 0635 _BAD original

23.U968 W / He θ / ρ 6074

The change in the effective length Δ L of the pipe as they can be caused by load changes has been related to the frequency requirements ^ f, and that the ratio Δί / A L has been improved by increasing the line length is, with longer lines improving the ratio indefinitely, it was found. The exploitable result of the combined lines and angular contact load connection should be the delivery high acoustic energy at a workpiece interface with a minimum of that required for power injection Easily make the resonance frequency change. This allows maximum power to be output at a constant frequency when a high Q transducer is used as the sound drive device.

The transmission line itself can be independent of the type of Connection with the workpiece surface be designed so that the frequency sensitivity to load changes (acoustic Changes) is improved, and that the ability of a converter Eur delivery of larger amounts of energy to a workpiece surface with a minimum requirement for frequency change is achieved. This can be the power output of a high Q converter with energy supply with constant frequency to a maximum bring.

003852/0635

O 1

33 f-

Table I.

Some of the resonance frequencies are typical of steel transmission lines

Transmission line
length waves
length at
20 kHz f _x 20.4 t ₂ Rear anemia frequencies (n H f 51.0 f 6 '^{; :} m 1, 7th 2, 8th i _g .). in kHz • ■ 'j; · O absolute
length (in
cm) ■. ■:. ·. 1/2 10.2 40.8 61.2 81.6 34.0 f f ffff
10 '11 12 - ' , # ■: O
co
OO ■; \. ■ 12 i 5: ■■■■■■■. 1 . 6.8 20.4 30.6 40.8 25.5 61 ♦ 2 he"
to 25th 1-1 / 2. 5.1 13.6 20.4 27.2 20.4 40 ,8th O 37.5 ■ '2 4.08 10.2 15.3 20.4 17.0 .30 .6 50 2-1 / 2 3.4 8.16 12.24 16.32 14.5 24 .5 .56 .64 36i72: cn 62.5 2.91 6 * 8 10.2 13.6 12 :, 75 ' 20th .4 28 .8th 52 .2 30.6 ■ 75 3-1 / 2 2.55 5.82 8.73 11.6 17th H ■ 23 .4 ■ 27 .28 26.19 33.2 ■ 87.5 4th 5.1 7.65 10., 2 15th , 30. 20th .85 23 a 22 * 95 29a .; ■ ·; D.
> 100 17th 20th 25.50 28.1 30 * 66

62288G

Table II

Change in resonance sensitivity (Relationship between theory and test results)

= 40, _e I ₂ «39, ^Δ f ■» 65.4n (n = 1, 2,

η ·. Δί (theory) Af (experiment)

300 Hz 300 400 425 400

600

4th 262 Hz 5 327 6th 392 7th 458 8th 523 9 589 10 654

009852/0635

Table III

L compared to Hz / 2.5 cm 1/2 λ line

ί? with

ΔΙ> = 2.5 cm compared with
1/2 λ line

Compare product

1/2 > -Line 2250 - ~. 450 3 V-line 400 560 # reinforcement 450 4th λ line 500 4 5 Ö% gain 1200 6th Λ line 300 75O # reinforcement 1680

No change
450/1200 loss
450/1680 loss

560% reinforcement $ 200 reinforcement Reinforcement

Claims (9)

01/23/1968 W / He O / p 6074 so claims; . 1., device for transmitting electromechanical energy to a Workpiece characterized by a source of electromechanical energy (11, 13) and a rigid standing wave transmission line (16) which is coupled to the mechanical energy output of the electromechanical energy source and driven at resonance by it and which has an overall length equal to Multiples of half the wavelength at the frequency of the transmitted energy. 2. Apparatus according to claim 1, characterized in that the Source (11, 13) of electromechanical energy is a multiple of half a wavelength at the transmitted frequency, and that the resonance of the transmission line is less due to changes in increments are influenced in length than in the transmission line half the wavelength. 3. Device according to claim 2, characterized in that the electromechanical _u rce (11, 13) and the coupled (loaded) transmission line (16) having a Q value, which increases with increasing length of the transmission line. 4. Apparatus according to claim 31, characterized in that a Frequency change with the change in length decreases and the Q-sensitivity increase of the transmission lines (16) for a long, unloaded transmission line a usable one Gain up to 3-3 1/2 times the wavelength at the frequency of the transmitted energy results. bath 09-8 52/06 3 5 January 23, 1968 W / He O / p 6074 5 «device according to claim 1, characterized in that the Transmission line (16) terminated with a damping load sen is. 6. Apparatus according to claim 5 »characterized in that the damping load reduces the Q factor of the line, so a usable frequency gain with the decrease in length Change with which the Q-sensitivity is achieved up to the range of four wavelengths. 7. Apparatus according to claim 5 »characterized in that the Transmission line is a resilient load (or tool * attached to the end of the transmission line) den is, and that the flexibility of the transmission line for the change in the resonance frequency requirement with little suspension ^ resistance less effective 8. Apparatus according to claim 5, characterized in that the Transmission line (12) is coupled to the load (15) at an angle which is substantially greater than 90, creating a Delivery of high-performance energy to a workpiece surface with a minimal need for frequency change is possible. 9. Apparatus according to claim 5, characterized in that the transmission line (16) is on the order of three to four Wavelengths at the frequency of the energy being transmitted. EAD ORIGINAL 009852/0635 ^^ ι ^Jl · * Lee rside