CS219587B1 - Ultrasound radiator of the longitudinal vibrations mainly for the gaseous medium - Google Patents

Description

This purpose is achieved by the ultrasonic radiator according to the invention, which is characterized in that the waveguide face of the ultrasonic transducer is provided with exciting offsets at the point of the nodal planes of the oscillations or the nodal oscillation points. The height of the excitation lugs is greater than the maximum desired amplitude of the diaphragm oscillations.

FIG. 2

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2,938 387 (54) Ultrasonic longitudinal oscillator, especially for gaseous environments

The invention relates to an embodiment of an ultrasonic emitter of post-oscillation, in particular for a gaseous environment.

The known ultrasonic radiators, consisting of a transducer and a waveguide, are firmly coupled to the membrane by the waveguide. Glued, soldered, screw or combined joints are known. Mechanical oscillations of the system with glued or soldered joints result in forced oscillations of the system, during which the part of the diaphragm located below the waveguide performs longitudinal oscillations and bending oscillations occur on the free part. At the edges of the joint, maximum stresses arise which, by operation and aging of the fastener, break the integrity of the joint and ultimately cause the whole surface of the waveguide to tear away from the membrane. Establishing the longitudinal and bending oscillations results in the oscillating system being far away from the resonance region of the diaphragm-to-transducer system, which makes it difficult to create an autofibrous system. As a result, there are large mechanical, acoustic losses that increase with the load on the system as well as the number of mounted transducers on the membrane. In addition, these inverters have a short link life. The waveguides mounted on the membrane by means of the center bolt of the may have the same negative properties even though the service life of the joint is substantially higher.

The above-mentioned drawbacks are eliminated by the ultrasonic longitudinal oscillator, especially for the gaseous medium according to the invention, which is based on the fact that the face of the waveguide of the ultrasonic transducer is provided with excitation projections at the nodal plane of the oscillations or nodal points. It is also an object of the invention that the excitation lugs are in the form of excitation ribs at the point of the nodal plane of oscillations. It is also within the scope of the invention that the excitation lugs are formed in the form of an excitation foot at the point of the nodal oscillations. It is also an object of the invention that the height of the excitation lugs is greater than the maximum desired amplitude of the diaphragm oscillations.

The ultrasonic radiator of the present invention achieves that the mechanical losses in the transducer-diaphragm oscillation system are minimal, which is particularly pronounced at higher densities of the environment in which the diaphragm oscillates. Another advantage is that the diaphragm is excited by a small amplitude of oscillations, which reduces the stress strain of the piezoceramics and thus increases its service life. The stress of the binding agent decreases at the point of contact of the excitation projection with the membrane due to the low value of the oscillation amplitude in the node passage

Oscillations. Ultraviolet emitters achieve high radiation power at low excitation amplitudes and low power inputs. By providing recesses between the excitation pads, it is allowed to oscillate freely in order to release the membrane.

The accompanying drawings show exemplary embodiments of ultrasonic radiators, wherein FIG. 1 is an axial sectional view of a portion of a waveguide coupled to the membrane through excitation ribs, to FIG. 2 is a cross-sectional view of the waveguide; FIG. 3 is a front elevational view of a waveguide; FIG. 4 is a perspective view of a waveguide face provided with excitation feet; FIG. 5 shows an enlarged detail of the connection of the excitation rib to the membrane, and FIG. 6 is an axial sectional view of a portion of a waveguide coupled to the membrane by means of a central screw and glued excitation ribs.

The ultrasonic longitudinal oscillator exemplifies consists of an ultrasonic transducer 1 (FIG. 1) provided with a waveguide 3 of circular cross-section. The whole of the waveguide 3 is provided with yard-like driving lugs 4 of height h and a width k, formed by drive ribs in the form of an annular ring. The excitation projections 4 are formed in nodal planes of oscillations.

The excitation lugs 4 are glued to the membrane 2 by an adhesive 7.

Another solution of the ultrasonic radiator for the creation of the edge membrane 2 (Fig. 3) has a cross-section of the waveguide 3 square. The excitation projections 4 are formed in the nodal planes of the oscillations in a straight line.

For three-dimensional oscillating diaphragms, the front of the waveguide 3 (Fig. 4) is provided at the nodal points with four flap-like driving lugs 4.

another embodiment of the ultrasonic radiator has a waveguide face 3 provided with three excitation projections 4 (Fig. 6) formed by excitation ribs in the form of an annular ring. The excitation lugs 4 are soldered to the membrane 2 and, moreover, the waveguide 3 is attached to the membrane 2 by a central screw 5.

The membrane 2 is excited by the excitation projections 4 of the waveguide 3 in the nodal planes of the oscillations, the membrane 2 oscillating free from the recesses between the excitation projections 4. The bending moment Ho is generated by the edge 3 of the excitation projection 4 on the diaphragm 2 on the half-width arm of the excitation projection 4 from the left or right side of the oscillation symmetry axis, depending on the current state of the diaphragm 2. phase and amplitude. The height h of the excitation lugs 4 is the greater the alcohol maximum required amplitude of the oscillation of the membrane 2.

Claims (4)

An ultrasonic longitudinal vibration emitter, in particular for a gaseous environment, comprising an ultrasonic transducer and a waveguide attached to the diaphragm face, characterized in that the face of the waveguide (3) of the ultrasonic transducer (1) is provided with excitation projections (4). 2. The ultrasonic radiator according to claim 1, characterized in that the excitation projections (4) are in the form of excitation ribs at the location of the nodal plane of oscillations. 3. The ultrasonic radiator according to claim 1, characterized in that the excitation lugs (4) are formed in the shape of the excitation shoe at the point of the nodal oscillation points. 4. The ultrasonic radiator according to claim 1, 2 and 3, characterized in that the height (h) of the excitation projections (4j) is greater than the maximum required amplitude of the diaphragm oscillations (2).