Coupling Element, Ultrasonic Transducer and Ultrasonic Flow Meter

Patent metadata

Field	Value
Publication number	US-2016116318-A1
Application number	US-201414787543-A
Country	US
Kind code	A1
Filing date	Apr 11, 2014
Priority date	May 3, 2013
Publication date	Apr 28, 2016
Grant date	—

Abstract

A coupling element for an ultrasonic transducer, which comprises a first recess provided for the arrangement of a piezoelectric element and comprising a terminal base surface in which an ultrasound signal generated by the piezoelectric element can be fed into the coupling element. The coupling element comprising inside the first recess one or a plurality of stops, each of which comprises at least one stop surface which extends along a plane, the plane extending parallel to the base surface of the first recess, and there being defined between this plane and the base surface a space for accommodating material for an acoustic adaptation layer. The invention further concerns an ultrasonic transducer and an ultrasonic flow meter.

First claim

1 - 14 . (canceled)

15 . A coupling element for an ultrasonic transducer, comprising:
a piezoelectric element; and a first recess provided for arranging said piezoelectric element, said first recess comprises a terminal base surface, on which an ultrasound signal that is generated by said piezoelectric element can be introduced into the coupling element, wherein: within said first recess, the coupling element comprises one or a plurality of stops, each having at least one stop surface, which extends along a plane; and said plane runs parallel to said base surface of said first recess and a space is defined between said plane and said base surface for accommodating material for an acoustic adaptation layer.

16 . An ultrasonic transducer, comprising:
a coupling element; and a piezo-electric element, said coupling element comprises a first recess with said piezoelectric element arranged in said first recess, said first recess comprises a terminal base surface, on which an ultrasound signal that is generated by said piezoelectric element can be introduced into said coupling element, wherein: in said first recess, a support disk is arranged, on whose upper side that is directed away from said coupling element, said piezoelectric element is arranged; said support disk and said base surface delimit a space in which an adaptation layer is arranged; and said support disk is provided for reducing thermal stresses on said piezoelectric element.

17 . The ultrasonic transducer or coupling element according to claim 16 , wherein:
said adaptation layer is a λ/4 adaptation layer (±25% of this value).

18 . The ultrasonic transducer or coupling element according to claim 16 , wherein:
said coupling element comprises a second recess which is connected with said first recess via an overflow channel.

19 . The coupling element according to claim 15 , wherein:
said plurality of stops is formed as a single stop as at least one bar, which peripherally protrudes into said first recess.

20 . The coupling element according to claim 15 , wherein:
said plurality of stops are formed as a plurality of bars, which peripherally protrude into said first recess and whose stop surfaces are in the plane.

21 . The coupling element according to claim 15 , wherein:
said plurality of stops has a stop formed as one or more spacer(s), which protrude from said base surface of said first recess.

22 . The coupling element according to claim 15 , wherein:
said stop(s) is/are an integral part of said coupling element.

23 . The coupling element according to claim 19 , wherein:
said bar(s) have an undercut.

24 . The ultrasonic transducer according to claim 16 , wherein:
the ultrasonic transducer has the following impedance ratios in the direction of propagation of the ultrasound signal:
Z Piezoelectric element >Z Support disk >Z Adaptation layer >Z Coupling element
wherein Z stands for the impedance (in Rayl) of said piezoelectric element, said support disk, said adaptation layer and said coupling element.

25 . The ultrasonic transducer according to claim 16 , wherein:
the ultrasonic transducer has a gradient of the thermal coefficient of expansion (ppm/K) in the direction of propagation of the ultrasound signal:
Coefficient of expansion Piezoelectric element <Coefficient of expansion Support disk <Coefficient of expansion Adaptation layer <Coefficient of expansion Coupling element

26 . The ultrasonic transducer according to claim 16 , wherein:
said adaptation layer consists of a polymerized synthetic material, which is polymerized under the influence of heat and shows a higher shrinkage during the polymerization than the temperature-related shrinkage of said coupling element and shows less shrinkage after polymerization than the temperature-related shrinkage of said coupling element.

27 . The ultrasonic transducer according to claim 16 , wherein:
said adaptation layer consists of a permanently elastic material with a Shore hardness of 30-60°±5° at 25° C. according to DIN 53505.

28 . The ultrasonic flow meter for determining the flow velocity or the volumetric flow rate of a measurement medium with a measuring tube and at least two ultrasonic transducers according to claim 16 , arranged along the measuring tube, wherein each one of said ultrasonic transducers comprises a coupling body with a contact surface, at which a generated ultrasound signal can be transmitted or received in the measuring tube or in the measurement medium.

Assignees

• Flowtec Ag

Inventors

• Wiest Achim
• Berger Andreas
• Grunwald Sascha

Classifications

• G01F1/662 Primary

  Constructional details · CPC title

• G01F15/006

  characterised by the use of a particular material, e.g. anti-corrosive material (G01F15/14 takes precedence) · CPC title