Robert Boschgmbh

Roberst Bosch Gmbh

Sami Radwan

Tobias Lang

Roland Mueller

Gerhard Hueftle

Bernd Kuenzl

Michael Horstbrink

Roland Wanja

Uwe Konzelmann

Hans Hecht

Christoph Gmelin

An ultrasonic transducer for use in a fluid medium is proposed. The ultrasonic transducer includes at least one transducer core which has at least one acoustic/electric transducer element, in particular a piezoelectric transducer element. The ultrasonic transducer furthermore includes at least one housing, at least one housing opening being at least partially sealed against the fluid medium with the aid of a sealing film which is connected to the transducer core. The sealing film has at least one expansion deformation which is configured to permit a relative movement between the transducer core and the housing.

Ultrasonic transducer for use in a fluid medium

An ultrasonic transducer for use in a fluid medium includes at least one housing, e.g., a sleeve, which has at least one interior space, and at least one transducer core having at least one electroacoustic transducer element is accommodated in the interior space. The housing has a housing wall at least partially enclosing the transducer core using at least one hollow space.

An ultrasonic transducer for use in a fluid medium includes at least one transducer core having at least one electroacoustic transducer element, and further includes at least one housing having at least two housing parts. At least one first housing part at least partially encloses the transducer core such that a rear side of the electroacoustic transducer element which faces away from the fluid medium is accessible. Furthermore, at least one second housing part is connected to the first housing part. The ultrasonic transducer is essentially terminated by the second housing part on its side, which faces away from the fluid medium.

An ultrasonic transducer for use in a fluid medium includes at least one housing having at least one inner space, at least one transducer core accommodated in the inner space, having at least one electroacoustic transducer element. The housing has at least one opening facing the fluid medium. The opening is covered at least partially by at least one sealing foil. An edge of the sealing foil is sealed by at least one sealing material.

A device for producing a current pulse includes supply terminals for providing a power supply voltage, and a switch which is situated in a control current branch between the supply terminals, which switch is configured to switch a control current through the control current branch as a function of an actuation signal. The device also has a current mirror having a control transistor and a signal transistor, the control transistor being situated in series to the first switch in the control current branch, and the signal transistor being configured to provide the current pulse as a function of the control current through the control transistor.

Device and method for generating a current pulse

An ultrasonic flow sensor for detecting a flow of a fluid medium in a flow tube includes at least one first ultrasonic transducer, at least one second ultrasonic transducer, and at least one waveguide configured to conduct ultrasonic waves between the at least one first ultrasonic transducer and the at least one second ultrasonic transducer by reflection on walls of the waveguide, and to enable the fluid medium to flow through. The ultrasonic waves are able to propagate between the first ultrasonic transducer and the second ultrasonic transducer on at least two ultrasonic paths. Sound energies of the ultrasonic waves transmitted on the at least two different ultrasonic paths differ from one another by no more than a factor of 100.

Ultrasonic flow sensor for detecting a flow of a fluid medium

An ultrasonic transducer for use in a fluid medium includes at least one piezoelectric transducer element, at least one matching body for the promotion of a vibrational coupling between the piezoelectric transducer element and the fluid medium, and at least one compensating body situated between the piezoelectric transducer element and the matching body for the reduction of thermal stresses, the compensating body having a coefficient of thermal expansion that is between a coefficient of thermal expansion of the piezoelectric transducer element and a coefficient of thermal expansion of the matching body.

A method for manufacturing an ultrasonic transducer for use in a fluid medium. At least one piezoelectric transducer element is joined directly or indirectly to at least one matching member for promoting vibration coupling between the piezoelectric transducer element and the fluid medium. A matching member is used which has at least one porous molding of a polymer.

Method for manufacturing an ultrasonic transducer

An ultrasonic transducer is described for use in a fluid medium. The ultrasonic transducer includes at least one piezoelectric transducer element and at least one matching element for promoting an oscillation injection between the piezoelectric transducer element and the fluid medium. The ultrasonic transducer also includes a housing (), the piezoelectric transducer element being inserted in the housing. The housing has at least one opening facing the fluid medium, the matching element being inserted at least partially into the opening. The ultrasonic transducer also has at least one sealing element, which seals at least one intervening space between the matching element and the housing in such a way that an inner space of the housing is at least largely sealed from the fluid medium.

A method for manufacturing an ultrasonic transducer for use in a fluid medium is described. The ultrasonic transducer includes at least one transducer core having at least one acoustic-electric transducer element. The ultrasonic transducer furthermore includes at least one housing which at least partially surrounds the transducer core and which has at least one opening facing the fluid medium. In the method, at least one sealing film is stretched and connected to the housing in the stretched state in such a way that the sealing film at least partially seals the opening.

Method for manufacturing an ultrasonic transducer for use in a fluid medium

An ultrasonic transducer for use in a fluid medium includes at least one transducer core having at least one acoustic/electric transducer element. The ultrasonic transducer furthermore includes at least one decoupling element which is configured to reduce a structure-borne noise coupling between the transducer core and a housing. The decoupling element includes at least one porous plastic material, in particular a foamed plastic material. The porous plastic material includes at least one thermosetting polymer and/or at least one thermoplastic.

For determining the transit time of an ultrasonic signal from an ultrasonic sensor that was launched into a measurement path by an ultrasonic converter, the phase shift of the ultrasonic signal is determined relative to a reference timing signal, and a remainder is determined as a measure of the transit time of the ultrasonic signal so that the phase shift is determined using a quadrature demodulation scheme, with which the received ultrasonic signal is inverted, in a segmented manner, using a timing signal and a phase-shifted timing signal, and the remainder is determined based on a characteristic quantity of the ultrasonic signal.

Ultrasound flow sensor with a modulo-2Pi for a remaining part tracing

An ultrasonic flow rate meter and a method for measuring the flow rate with the aid of ultrasound are described, having at least two ultrasonic transducers situated offset in a flow channel in the flow direction for transmitting and receiving ultrasound wave packets, so that ultrasound propagation times from one of the ultrasonic transducers to the other, and vice-versa, can be determined in an electronic part, and having a pressure sensor associated with the flow channel for determining the pressure in the flow channel. Measured values for an engine control that is as accurate as possible are determinable by accurately detecting the incoming air in the intake of a motor vehicle internal combustion engine.

Ultrasonic flow rate meter having a pressure sensor

The measurement of volume flows or mass flows in the intake system of motor vehicle internal combustion engines plays a significant role in reducing pollutant emissions. Therefore, an ultrasonic flow meter for measuring a flow rate of a fluid flowing in a primary flow direction is described. The ultrasonic flow meter has at least two ultrasonic transducers, the ultrasonic transducers being capable of emitting and/or receiving ultrasonic waves at an angle &#x3b1; to the primary flow direction which is different from 90&#xb0;. Furthermore, the ultrasonic flow meter has at least one guide element which is entirely or partially situated in the fluid. This guide element diverts at least one part of the flowing fluid in such a way that in the diversion, a velocity component is transferred to at least one part of the flowing fluid perpendicular to the primary flow direction. Guide vanes or displacers in particular are described as guide elements. In addition, turbulators may be provided on the guide elements, the turbulators generating a longitudinal fluid bed along the guide elements and thus causing the flow of the fluid to have a better contact with the guide elements when flowing around them. This reduces turbulences within the ultrasonic flow meter. Compared to the devices known from the related art, the ultrasonic flow meters described are distinguished by an improved signal-to-noise ratio and accordingly by a higher measuring precision.

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Stuttgart, Germany

Sami Radwan