Ultrasonic transducer and method for manufacturing an ultrasonic transducer

Abstract

The invention relates to an ultrasonic transducer comprising an acoustic transformer, wherein the acoustic transformer has a transformer body having a hollow space, and there lies between the hollow space and the medium a membrane, whose center oscillates freely. Furthermore, the invention relates to methods for manufacturing such an acoustic transformer.

Claims

1. An ultrasonic transducer for use in ultrasonic, flow measuring devices for measuring flow velocity or volume flow of media in a pipeline, comprising: a piezotransducer embodied to produce and/or to detect ultrasonic signals; and an acoustic transformer acoustically coupled with the piezotransducer, the acoustic transformer having: a transformer body having at least one hollow space within the transformer body and formed by the transformer body; and a membrane between the at least one hollow space and an exterior of the acoustic transformer, wherein the membrane is embodied such that the center portion oscillates freely, and wherein the acoustic transformer is embodied to transmit ultrasonic signals bidirectionally via the membrane.

2. The ultrasonic transducer as claimed in claim 1, wherein the ultrasonic transducer, not considering the at least one hollow space opening, is rotationally or axisymmetric relative to the symmetry axis.

3. The ultrasonic transducer as claimed in claim 1, wherein the acoustic transformer is constructed of a ceramic, glass-like, or metal material.

4. The ultrasonic transducer as claimed in claim 1, wherein a working frequency of the ultrasonic transducer is at least 10 kHz and at most 10 MHz.

5. The ultrasonic transducer as claimed in claim 1, wherein a working frequency of the ultrasonic transducer is at least 50 kHz and at most 500 kHz.

6. The ultrasonic transducer as claimed in claim 1, wherein a membrane thickness is at least 0.01 mm and at most 10 mm.

7. The ultrasonic transducer as claimed in claim 1, wherein a membrane thickness is at least 0.1 mm and at most 1 mm.

8. A method for manufacturing an acoustic transformer of an ultrasonic transducer for use in ultrasonic, flow measuring devices for measuring flow velocity or volume flow of media in a pipeline, comprising: manufacturing using a generative method including a 3D printing method or a selective laser sintering method, wherein the acoustic transformer includes a transformer body having at least one hollow space within the transformer body and formed by the transformer body and having a membrane between the at least one hollow space and an exterior of the acoustic transformer, and wherein the membrane is embodied such that the center portion oscillates freely.

9. A method for manufacturing an acoustic transformer of an ultrasonic transducer for use in ultrasonic, flow measuring devices for measuring flow velocity or volume flow of media in a pipeline, comprising: manufacturing a number of individual parts; and combining the individual parts by a combining process including bonding with an adhesive or welding, wherein the acoustic transformer includes a transformer body having at least one hollow space within the transformer body and formed by the transformer body and having a membrane between the at least one hollow space and an exterior of the acoustic transformer, and wherein the membrane is embodied such that the center portion oscillates freely.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be explained in greater detail based on examples of forms of embodiment illustrated in the appended drawing, the figures of which show as follows:

(2) FIG. 1 shows a perspective, external view of an ultrasonic transducer housing of an ultrasonic transducer of the invention;

(3) FIG. 2 shows a cross section through a form of embodiment of the ultrasonic transducer;

(4) FIG. 3 to FIG. 5.1 show cross sections through forms of embodiment of the acoustic transformer, which is a component of the ultrasonic transducer housing;

(5) FIG. 5.2 shows a perspective, external view of the form of embodiment of FIG. 5.1;

(6) FIG. 6 shows another form of embodiment of the ultrasonic transducer;

(7) FIG. 7.1 shows a perspective, external view of a form of embodiment of the ultrasonic transducer housing;

(8) FIG. 7.2 shows a cross section through the form of embodiment of FIG. 7.1;

(9) FIGS. 8 to 12 show cross sections through forms of embodiment of the ultrasonic transducer; and

(10) FIG. 13 shows a schematic view of an ultrasonic, flow measuring device mounted on a pipeline.

DETAILED DESCRIPTION

(11) The perspective, external view of a first example of an embodiment of an ultrasonic transducer housing 1 shown in FIG. 1 shows a housing with an external thread 1.1 and a terminal membrane forming a sound entrance/exit surface 3, wherein the housing except for the external thread is rotationally symmetric relative to a symmetry axis 2.

(12) The cross section through the ultrasonic transducer housing 1, as shown in FIG. 2, shows a piezotransducer 4 mounted to the housing in the interior of the housing, an acoustic transformer 1.2, which is a component of the ultrasonic transducer housing, as well as a hollow space 5.1 located in the acoustic transformer and having rounded inner surfaces, wherein the inner surface bounding the membrane exhibits a flattening.

(13) The cross section through the acoustic transformer 1.2 shown in FIG. 3 shows an example of an embodiment 5.2 of the hollow space located in the acoustic transformer, wherein the cross sectional area of the hollow space is bounded by straight lines.

(14) The cross section through the acoustic transformer 1.2 shown in FIG. 4 shows an example of an embodiment of the hollow space of FIG. 3, wherein the hollow space has a terminal, axial opening.

(15) The cross section through the acoustic transformer 1.2 shown in FIG. 5.1 shows an example of an embodiment of the hollow space of FIG. 3, wherein the hollow space has openings in its lateral surface.

(16) FIG. 5.2 shows a perspective, external view of the ultrasonic transducer housing comprising the example of an embodiment of FIG. 5.1 and having two visible, hollow space openings located in the lateral surface.

(17) The cross section through the acoustic transformer 1.2 shown in FIG. 6 shows a example of an embodiment of the hollow space of FIG. 3 with openings in its lateral surface, wherein the diameter of the openings forms a significant portion of the hollow space dimensions.

(18) The perspective, external view of an example of an embodiment of the ultrasonic transducer housing shown in FIG. 7.1 shows a housing 1 having an external thread 1.1 and a membrane forming a sound entrance/exit surface 3; wherein the housing except for the external thread is rotationally symmetric relative to the symmetry axis 2; wherein the housing has, furthermore, in the region of the membrane 3 a recess 8.1 and a collar 1.3.

(19) The cross section shown in FIG. 7.2 through the acoustic transformer 1.2 of the ultrasonic transducer housing illustrated in FIG. 7.1 includes a piezotransducer 4 mounted to the housing in the interior of the housing and a hollow space 5.6 located in the acoustic transformer 1.2, wherein the membrane is partially associated with the collar 1.3.

(20) The cross section through the acoustic transformer 1.2 shown in FIG. 8 shows another form of embodiment 5.7 of the hollow space located in the acoustic transformer and having rounded inner surfaces, wherein the inner surface away from the membrane 3 exhibits a flattening.

(21) The cross section through the acoustic transformer 1.2 shown in FIG. 9 shows another form of embodiment of the acoustic transformer, wherein in cross section the outer surface contour is symmetric with the adjoining inner surface relative to contour symmetry axes 9.

(22) The cross section through the acoustic transformer 1.2 shown in FIG. 10 shows a form of embodiment similar to FIG. 9 with another hollow space geometry with an outer surface contour illustrated enlarged in FIG. 12.

(23) The cross section through the acoustic transformer 1.2 shown in FIG. 11 shows a form of embodiment similar to FIG. 9 or FIG. 10 with another hollow space geometry and a terminal, axial opening of the membrane.

(24) The ultrasonic, flow measuring device shown schematically in FIG. 13 includes two ultrasonic transducers 22, 23 in contact with a pipeline 24, through which a medium is flowing.