RU2068741C1 - Ultrasonic converter oscillation velocity symmetrical transformer - Google Patents

Abstract

FIELD: ultrasonic oscillatory system. SUBSTANCE: oscillatory system transformer has equal-size section envelope made in the form of hollow axially-symmetric waveguide with curvilinear or conical generatrix of mass center surfaces whose cross sizes at output end exceed the seat input end. Calculations of coordinates of generatrix of envelope mass center surfaces are given in description of the invention. EFFECT: enlarged operating capabilities. 2 cl, 4 dwg

Description

 The invention can find application in the engineering, shipbuilding industries and other sectors of the economy, as part of an oscillatory system of ultrasonic frequency, for example, in metal cutting and metal forming processes.

 Known vibrational transformers designed to transfer vibrational energy from areas with small transverse dimensions to areas whose dimensions exceed the half-wavelength, for example, oscillatory systems or their elements according to copyright certificates N 227736, 231244. However, they do not provide a uniform or "piston" distribution of displacements on the output surface (see II Teumin "Ultrasonic oscillatory systems"). A transformer with an outer surface in the form of a cylinder and an inner surface in the form of a paraboloid (according to ed. St. N 227736, class B 06 b 1/08, 1967) is designed to transmit longitudinal vibrations at the resonant frequency of the system, however, it cannot be used to match elements with different sizes of outer diameters, for example, annular mating surfaces, as it has different cross-sectional areas normal to the axis of symmetry, and does not provide "piston" oscillations on the output surface in a wide frequency range, uniformity of distribution dividing the oscillation amplitude when the frequency and the load resistance of the system to specify waveforms. The transformer, made in the form of a gently sloping truncated circular cone (according to ed. St. N 231244, class B 06 b 1/08, 1966) has an angle between the outer surface and the axis of symmetry of more than 40 degrees and is intended for radiation into the technological environment by excitations on the output surface of bending vibrations.

 Closest to the method of technical implementation of this invention is an oscillatory system according to ed. St. N 278272 (class B 06 b 1/00), in which the transition elements are made in the form of hollow truncated cones.

 At the same time, this system does not provide efficient transmission of “piston” vibrations to technological objects and media, the input dimensions of which significantly exceed the wavelength of longitudinal vibrations.

 The subject of this invention is the creation of a symmetric transformer of vibrational velocity, providing the transfer of "piston" vibrations from a surface whose dimensions are much smaller than the wavelength, on a surface with dimensions substantially greater than the wavelength at the resonant frequency of the system.

 The claimed effect is achieved due to the formation of a vibrational velocity transformer with specified dimensions of the input and output surfaces in the form of an axisymmetric conical shell, the cross-sectional areas of which are perpendicular to its axis of symmetry are equal and oriented relative to the surface of the centers of mass with a rectilinear generatrix, as shown in FIG. 1, or an outer conical surface with a straight generatrix, as shown in FIG. 2.

 It was experimentally established that the stability of "piston" modes of vibration in a shell transformer of vibrational velocity is ensured up to an opening angle of not more than 40 degrees, as shown in FIG. 3 and FIG. 4. Determination of the height of the transformer of the vibrational velocity at the dimensions of the input and output diameters of the “piston” shell specified for structural reasons is carried out by the number of half-waves of longitudinal vibrations in the transformer of the vibrational velocity at the resonant frequency of the oscillating system. The calculation of the resonant length (height) of the piston transformer of vibrational velocity according to this invention should be carried out along the length of the generatrix of the conical surface of the centers of mass in 1 case (Fig. 1) and along the curved surface of the centers of mass in 2 cases (Fig. 2).

(1)
где α угол раскрытия между осью симметрии и образующей конической поверхности центров масс α∈[0,40^°]

диаметр образующей конической поверхности центров масс на выходном торце трансформатора.The calculation of the geometric shape of the piston transformer of vibrational velocity in 1 case is carried out according to the formulas:

(one)
where α is the opening angle between the axis of symmetry and the generatrix of the conical surface of the centers of mass α∈ [0.40 ^° ]

the diameter of the generatrix of the conical surface of the centers of mass at the output end of the transformer.

диаметр образующей конической поверхности центров масс на входном торце трансформатора.

the diameter of the generatrix of the conical surface of the centers of mass at the input end of the transformer.

 f oscillation frequency.

 n is an integer of half-waves.

 C is the speed of propagation of vibrations in the material.

(2)
где Н высота трансформатора.

(2)
where H is the height of the transformer.

(3)
где D_x наружный диаметр оболочки трансформатора в рассматриваемом сечении Х.

(3)
where D _{x the} outer diameter of the transformer shell in the cross section X.

h _{x the} distance from the input end of the transformer to the cross section X. h _x ∈ [0, H].

D _{o the} outer diameter of the shell of the transformer at the output end.

D _{in the} outer diameter of the transformer shell at the input end.

(4)
где d_x внутренний диаметр оболочки трансформатора в рассматриваемом сечении Х.

(4)
where d _{x the} inner diameter of the transformer shell in the cross section X.

 d inner diameter of the transformer shell at the input end.

(5),
где

Система (5) решается относительно неизвестных параметров Н и α
где Н высота трансформатора.The calculation of the geometric shape of the piston transformer of vibrational velocity in the 2 case is carried out according to the formulas:

(5),
Where

System (5) is solved with respect to unknown parameters H and α
where H is the height of the transformer.

 C is the speed of propagation of vibrations in the material.

 f oscillation frequency.

 n is an integer of half-waves.

D _{in the} outer diameter of the transformer shell at the input end.

D _{o the} outer diameter of the shell of the transformer at the output end.

 d inner diameter of the transformer shell at the input end.

a opening angle between the axis of symmetry and the outer conical surface. α∈ [0.40 ^° ]
d _x = D _in + 2 • h _x • tgα (6)
where D _{x the} outer diameter of the transformer shell in the cross section X.

(7)
где d_x внутренний диаметр оболочки трансформатора в рассматриваемом сечении Х.h _{x the} distance from the input end of the transformer to the cross section X. h _x ∈ [0, H]

(7)
where d _{x the} inner diameter of the transformer shell in the cross section X.

 It was experimentally established that for any other law of changing the cross-sectional shape of the transformer of vibrational velocity, an increase in its output size relative to the dimensions of the input end due to the opening angle even by 5 degrees (for exponential, catenoidal and the case of equal wall thickness in the cross section) causes a “piston” violation forms of vibrations in the shell and the appearance at the output end of a complex wave topography in the form of bending, shear and other types of diagrams of the distribution of vibrational velocities and.

 The physical nature of the described effect is explained by favorable conditions for the “interaction” between adjacent equal-sized surfaces of “equal phases” through which the energy of elastic vibrations is distributed. A model for optimizing this interaction can be a position known from theoretical mechanics on the coefficient of energy transfer equal to unity by masses of equal magnitude. With certain geometric ratios of the surfaces forming the body of the transformer of vibrational velocity (waveguide), this mechanism works as long as the areas (and hence the masses) of the interacting volumes bounded by the surfaces of "equal phases" remain equal to each other, which is equivalent to the propagation of normal forms of vibration without reflection from the walls of the waveguide.

 As shown above, waveguides of equal cross sections are characterized by the highest resistance to “piston” modes of vibration. YYY1 YYY2 YYY3

Claims (3)

 1. Symmetric transformer of vibrational velocity of a variable cross section of an ultrasonic transducer containing a shell of equal cross-sections, characterized in that, in order to increase the efficiency of transmission of vibrations to technological objects and media, the shell is made in the form of a hollow axisymmetric waveguide with a curved or conical generatrix of the surfaces of the centers of mass, transverse the dimensions of which at the output end are larger than the sizes at the input end. 2. The transformer according to claim 1, characterized in that for a shell with a conical generatrix of the surface of the centers of mass, its coordinates are calculated by the formulas

where α is the opening angle between the axis of symmetry and the generatrix of the conical surface of the centers of mass,
α ∈ [0 ^° ; 40 ^° ],

the diameter of the generatrix of the conical surface of the centers of mass at the output end of the transformer;

the diameter of the generatrix of the conical surface of the centers of mass at the input end of the transformer;
f oscillation frequency;
n is an integer of half-waves;
c is the velocity of propagation of vibrations in the material;

where H is the height of the transformer;

where D _{x the} outer diameter of the transformer shell in the cross section X;
h _x is the distance from the input end of the transformer to the cross section X under consideration, h _x ∈ [O, H];
D _{o the} outer diameter of the transformer shell at the output end;
D _{in the} outer diameter of the transformer shell at the input end;

where d _{x the} inner diameter of the shell of the transformer in the cross section X;
d inner diameter of the transformer shell at the input end. 3. The transformer according to claim 1, characterized in that for a shell with a curved generatrix of the surface of the centers of mass, its coordinates are calculated by the formulas

the system is solved with respect to unknown parameters H and α
where H is the height of the transformer;
with the speed of propagation of vibrations in the material;
f oscillation frequency;
n is an integer of half-waves;
D _{in the} outer diameter of the transformer shell at the input end;
D _{o the} outer diameter of the transformer shell at the output end;
d inner diameter of the transformer shell at the input end;
a opening angle between the axis of symmetry and the outer conical surface, α ∈ [0 ^° ; 40 ^° ]
D _x D _in + 2 • h _x • tgα
where D _{x the} outer diameter of the transformer shell in the cross section X;
h _{x the} distance from the input end of the transformer to the cross section X under consideration, h _x ∈ [O; H];

where d _{x is the} inner diameter of the transformer shell in the cross section X.

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