EP2800950A2

EP2800950A2 - Sensor device for non-contact detection of a rotational property of a rotatable object

Info

Publication number: EP2800950A2
Application number: EP12801480.0A
Authority: EP
Inventors: Marc Rosenland
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2012-01-04
Filing date: 2012-11-22
Publication date: 2014-11-12
Also published as: CN104136889A; WO2013102511A3; DE102012200091A1; WO2013102511A2; US20140366632A1

Abstract

The invention relates to a sensor device (10) for non-contact detection of at least one rotational property of a rotatable object (12), particularly for detecting a rotational speed of a compressor wheel (14) for a turbocharger (18). The sensor device (10) comprises at least one sensor housing (22). The sensor device (10) further comprises at least one magnetic field generator (26) for generating a magnetic field at the location of the rotatable object (12) and at least one magnetic field sensor (28) for detecting a magnetic field generated by eddy currents of the rotatable object (12). The sensor device (10) further comprises at least one temperature sensor (30). The magnetic field generator (26) and the magnetic field sensor (28) are arranged at least in part together in a sensor section (24) of the sensor housing (22). The temperature sensor (30) is arranged at least in part in the sensor section (24).

Description

description

title

Sensor device for non-contact detection of a rotational property of a rotatable object

State of the art

Numerous sensors are known from the prior art which detect at least one rotational property of rotatable, in particular rotating, objects. Under rotation properties are generally understood to be properties that describe the rotation of the rotatable article at least partially. These may be, for example, angular velocities, rotational speeds, angular accelerations, angles of rotation, angular positions or other properties which are a

continuous or discontinuous, uniform or non-uniform rotation or rotation of the rotatable article can characterize.

Examples of such sensors are from Konrad Reif (ed.): Sensors in the motor vehicle, 1. Edition 2010, pages 63-73 known. A particular focus of the present invention, to which the invention is, however, not limited in principle, lies in a speed detection, in particular the speed detection of charging devices, in particular in exhaust gas turbochargers. This speed detection can be set up in particular to detect a rotational speed of an impeller of the exhaust gas turbocharger. This impeller is usually equipped with a plurality of compressor blades and can therefore also be referred to as a compressor wheel. From DE 196 23 236 A1 a method for measuring the movement of a part in an interior of a housing is known. In this case, a permanent magnetic field acting essentially perpendicular to a direction of movement of the part is generated, and induction signals are generated and measured as the part passes by.

For example, the magnetic field can be generated with a permanent magnet and the induction signals generated by eddy currents in moving compressor blades can be generated, can be detected with a coil arranged outside the compressor housing.

From US 2007/0139044 A1 a speed sensor is known in which the electrical components are surrounded by a temperature-resistant material.

US 2007/01 19249 A1 discloses a sensor device in which a first and a second cavity are formed in a housing section. In the first cavity, for example, a speed sensor for measuring a

Vehicle speed can be introduced and in the second cavity can

Temperature sensor for measuring an ambient temperature of the vehicle are introduced.

Despite the numerous advantages of the known from the prior art

Sensor devices for detecting a rotational property of a rotatable

This item still has room for improvement. So will the

Sensor device for detecting a rotational property of a rotating

Article, in particular a compressor wheel of an exhaust gas turbocharger, usually attached to the compressor housing, since the thermal ambient conditions are easier to control at lower temperatures compared to the exhaust gas side. Other physical quantities, such as pressure or temperature, are detected separately from the speed sensors in the vicinity of the exhaust gas turbocharger. This requires additional components and sensors for monitoring and controlling the internal combustion engine.

Disclosure of the invention

It is therefore proposed a sensor device for detecting a rotational property of a rotatable object, which knows the disadvantages

Sensor devices at least largely avoids and allows a simple structure, in addition to the rotation property and one or more other physical parameters or quantities qualitatively and / or quantitatively with the

Sensor device can be detected. The sensor device for non-contact detection of at least one rotational property of a rotatable object, in particular for detecting a rotational speed of a compressor wheel of a turbocharger, comprises a sensor housing, wherein the sensor device further comprises at least one magnetic field generator for generating a magnetic field at the location of the rotatable object and at least one

Magnetic field sensor for detecting a magnetic field generated by eddy currents of the rotatable article. The sensor device further comprises at least one temperature sensor. The magnetic field generator and the magnetic field sensor are at least partially arranged together in a sensor section of the sensor housing. The temperature sensor is at least partially disposed in the sensor section.

The sensor housing can be attached to a device comprising the rotatable object. The magnetic field generator may be aligned along an axis and a longitudinal axis of the sensor section may extend substantially parallel to the axis of the magnetic field generator, wherein the sensor section is formed so that in a mounted on the rotatable article device state of the sensor housing between the sensor section and the rotatable object in a direction substantially parallel to the longitudinal axis of the

Sensor section is a part of the device. The sensor device can have an evaluation circuit and a signal of the temperature sensor can be transmitted separately from or together with a signal of the magnetic field sensor from an output of the evaluation circuit, for example to a control device. The signal of the temperature sensor can be transmitted together with the signal of the magnetic field sensor from an output of the evaluation circuit and by means of a

Modulation method be modulated on the signal of the magnetic field sensor. The signal of the temperature sensor can be modulated by means of pulse width modulation or by means of a multiplex method to the signal of the magnetic field sensor. The signal of the temperature sensor can be transmitted separately from the signal of the magnetic field sensor from the output of the evaluation circuit and the evaluation circuit can have a terminal which is used to transmit the signal of the temperature sensor

is set up. The signal of the temperature sensor can be transmitted separately from the signal of the magnetic field sensor from the output of the evaluation circuit and the evaluation circuit can have an intelligent interface, which is adapted to transmit the signal of the magnetic field sensor. The magnetic field sensor may be an inductive magnetic field sensor. The temperature sensor can be used to detect a temperature of Wall of the device comprising the rotatable object may be formed. The sensor portion may be formed as a non-magnetic sleeve. The sensor section can be introduced into a receptacle in a wall of the device and in

introduced state may be in the direction of the longitudinal axis of the sensor portion between the sensor portion and the part of the device are a gap. The dimension of the part of the device may be in the direction of the longitudinal axis from 0.1 mm to 2 mm, preferably from 0.2 mm to 1, 8 mm and more preferably from 0.5 mm to 1 mm. The sensor section may be insertable into a receptacle in a wall of the device, and in the inserted state, a coaxial gap may at least in sections be located between the wall of the device and the sensor section. The sensor device may be a speed sensor and the rotatable object may be a compressor wheel of a supercharger, in particular of an exhaust gas turbocharger. Of the

The object can be rotatable about a rotation axis, wherein the longitudinal axis of the

Sensor section in a mounted on the device state of the

Sensor housing at an angle of 25 ° to 65 ° and more preferably from 30 ° to 60 ° and more preferably of 45 °, is arranged to the rotation axis. For example, a compressor wheel may be rotatable about an axis of rotation, wherein the longitudinal axis of the sensor section in a mounted on the device state of

Sensor housing at an angle of 25 ° to 65 ° and more preferably from 30 ° to 60 ° and more preferably of 45 °, is arranged to the rotation axis. The

Sensor housing may have webs and / or circular projections which contact the device in a state of the sensor housing attached to the device comprising the rotatable article. The sensor device may include an amplifier configured to amplify a signal provided by the magnetic field sensor.

The magnetic field sensor may in particular comprise at least one coil. This offers the advantage that large sensor surfaces can be realized by means of coils. At the same time can be through the use of coils temperature sensitivities, which

For example, occur in semiconductor magnetic field sensors or magnetic-resistant sensors avoid. The coil may for example be a flat coil and may preferably have a coil cross section with a winding surface, which may be flat or curved, which may exceed a coil height of the coil, for example along an axis of the coil. The magnetic field generator may in particular comprise one, for example exactly one, two, three or more permanent magnets. The magnetic field generator can in particular be at least partially enclosed by the magnetic field sensor. This can

for example, take place in that the coil completely or partially surrounds the permanent magnet. The permanent magnet, for example, a

Rectangular shape and / or have an oval shape, with a longer side or longer semi-axis in a plane which includes the axis of the rotatable article. In the context of the present invention, rotational properties are generally to be understood as properties which at least partially describe the rotation of the rotatable object. This may, for example, to

Angular velocities, speeds, angular accelerations, angles of rotation;

Angular positions or other properties that may characterize a continuous or discontinuous, uniform or non-uniform rotation or rotation of the rotatable article act.

For the purposes of the present invention, a temperature sensor means any type of known temperature sensor, in particular so-called NTCs, ie. H. temperature-dependent electrical resistors with a negative

Temperature coefficients whose electrical resistance varies with temperature, in particular decreases with increasing temperature. Conceivable, however, are PTCs, d. H. electrical resistors with positive temperature coefficients whose resistance increases with increasing temperature.

In the context of the present invention, by the term "substantially parallel" with reference to one direction, a deviation of preferably not more than 15 °, in particular not more than 10 °, in particular not more than 5 ° and particularly preferably 0 ° from the direction to which reference is made , to understand.

In the context of the present invention, the indication of angles between two directions or axes is to be understood as meaning an angle between the directions or axes, the axes intersecting in an imaginary way, with the exception of one

perpendicular arrangement to each other span between two pairs of angles of different sizes, in the context of the present invention, an angle of the smaller angle pair is always meant. In the context of the present invention, a housing interior in particular means that space in a housing of a sensor device for non-contact

Understanding a rotation property of a rotatable object to understand, in which the electronics, such as the evaluation circuit and their electrical connections, is located, so that this can also be referred to as electronics compartment.

Under a pulse width modulation is in the context of the present invention a

Understand a method in which a technical size, such as a

Voltage signal or an electric current, between two values changes. At constant frequency, the duty cycle of the signal is modulated, ie the width of a pulse. The modulation describes a process in which a useful signal to be transmitted, such as a temperature signal changes a so-called carrier, such as a speed signal, i. modulated. The information or message contained in the useful signal is recovered on the receiving side by a demodulator again. The duty cycle, which is also referred to as Aussteuergrad, gives the ratio of the pulse duration for a periodic sequence of pulses

Pulse period duration. The duty cycle is given as a dimensionless ratio with a value of 0 to 1 or 0 to 100%.

In the context of the present invention, a multiplex method is to be understood as meaning methods for signal and message transmission in which a plurality of signals are combined or bundled and transmitted simultaneously via a medium, such as a line, a cable or a radio link. Often

Multiplexing also combined to achieve even higher usage. The bundling takes place after the user data has been modulated onto a carrier signal.

Accordingly, they are demodulated at the receiver after unbundling, the so-called demultiplexing. The sensor device may be a speed sensor, for example. The speed sensor consists for example of a passive sensor head or sensor section, an active signal amplifier / pulse shaper, a housing with mounting socket and a plug connection. The sensor head may comprise, for example, a magnetic circuit with inductance, such as a thin wire winding, on a bobbin. A holder may lie within a sleeve of the sensor head and all Include individual parts of the sensor head together with connection technology and an optional temperature sensor element. The holder may for example be completely or partially injection molded from plastic. Of the

Temperature sensor that detects the temperature in the sensor head is positioned as close to the inner wall of the sleeve and can be, for example, a hot or cold conductor or semiconductor. For example, the temperature sensor is a so-called NTC, ie an electrical resistor with a negative temperature coefficient, in which the electrical resistance decreases with increasing temperature. The housing, including connector and lid, such as plastic, accommodates the sleeve, the holder, the electronics and serves to mechanically fix the components and to protect against media. An outer contour of the housing, especially in the region of a bearing surface, is designed accordingly for thermal decoupling. Of the

Signal amplifiers in the housing, for example, on a board with analog and / or digital Bestanteilen, which may be integrated, for example, in an application-specific integrated circuit (ASIC) processes the speed signal and forwards this via the connector to, for example, an engine control unit. A

Fixing bushing, which may be integrated into the housing and may be formed by this as a projection, is provided for mechanical fixation on, for example, a compressor housing.

By the sensor according to the invention, a sensor housing with a

Sensor section can be used for a further signal transmission without the structural size of the sensor is increased. As a result, an already existing speed sensor is extended, for example, to a compressor housing of an exhaust gas turbocharger by the function of temperature detection. The sensor head is positioned as close as possible to the passing compressor blades of the compressor wheel. The bore for receiving the sensor head is designed such that the interior of the

Compressor channel is not broken and the scanning of the wings of the

Compressor wheel through the remaining wall of the externally mounted blind hole in the compressor housing. The smallest possible wall thickness in the compressor housing between the sensor head and the blade of the compressor wheel has an advantageous effect on the signal-to-noise ratio of the speed signal and is desirable since a higher one

Signal amplitude is delivered. The sensor head or sensor section of the speed sensor, which is mounted deep in the compressor housing, is supplemented by an integrated temperature sensor, thereby directly detecting the temperature of the compressor housing. Depending on the operating speed between the compressor inlet, ie the front side of the compressor wheel, and compressor output, ie radially largest circumference of the compressor, reached

Pressure ratio results in a very strong increase in temperature of the compressed intake air. The inwardly sealed bottom hole in the compressor housing, the thermal load of the sensor head is reduced because it is not directly in contact with the hot compressed intake air in the compressor in the internally dense bottom hole. It sets a mean temperature at the sensor head, the middle

Temperature of the compressor housing corresponds. The temperature sensor can

for example, mounted in the existing space between the sensor head and signal amplifier to the existing, above-mentioned holder, installed in the non-magnetic sleeve and electrically connected to the signal amplifier board. The temperature-dependent resistance of the temperature sensor can be detected in the signal amplifier and further processed. Preferably, the temperature value is transmitted via the existing signal line to the control unit. For this purpose, for example, a pulse width modulation of the speed signal can be used. This temperature can, for example, as a diagnostic value for component protection and the like of a

Control unit be further processed. The temperature signal output to a speed sensor according to the invention can be done by means of an additional pin. The signal of the integrated temperature sensor is fed via an additional pin to the control unit; the mass of the speed sensor serves as a common

Ground connection. Alternatively, a modulation of the detected temperature value to the speed signal is possible. The speed information is for example as

Rectangular signal passed to the control unit with a corresponding consideration of the period or the frequency evaluation. There is also the option of temperature information via the electronics integrated in the speed sensor

For example, to transmit pulse width modulated. A corresponding correlation

Temperature / pulse width can be done via software functions. Furthermore, alternatively, an intelligent interface can be used. Depending on the design and complexity of integrated in the speed sensor electronics can therefore also have a smart

Interface, such as single-edge nibble transmission (SENT), controller Area Network (CAN) or the like, the information is transmitted.

Preferably, a modulation of the detected temperature value to the

To apply speed signal, since the sensor provides a real-time signal of the speed and thus runtime losses of the signal processing can be avoided. Accordingly, no additional components other than the actual temperature sensor in the exhaust gas turbocharger are required. Also, there is no additional wiring in the vehicle or on the engine required. As a result, for example, an intake temperature after the compressor can be determined indirectly. This can be helpful as an additional control variable for the air density correction in the control unit.

Brief description of the drawings

Further optional details and features of preferred embodiments of the invention will become apparent from the following description of exemplary embodiments, which are shown schematically in the drawings.

Show it:

FIG. 1 shows a first exemplary embodiment of a sensor device according to the invention,

FIG. 2 shows a side view of a compressor housing,

FIG. 3 shows a side view of the rotor of an exhaust gas turbocharger,

Figure 4 is a perspective sectional view of the sensor device in a on a

Compressor housing attached state, and

Figure 5 shows an enlarged section of the compressor housing and the

Compressor wheel.

Embodiments of the invention

FIG. 1 shows a first exemplary embodiment of a sensor device 10 according to the invention for contactless detection of at least one rotational property of a rotatable object 12 (see FIG. 2). As shown in Figure 2 and Figure 3, the rotatable article 12 is in this embodiment, for example, a compressor 14 of a compressor 16 of the rotor of an exhaust gas turbocharger 18, which rotates about an axis of rotation 20, in particular rotates. For example, the

Sensor device 10 designed as a tachometer, the speed of the Compressor 14 detected. However, other applications and applications are generally possible.

The sensor device 10 comprises a sensor housing 22, which may be at least partially made of plastic and has a sensor portion 24 which may be at least partially made of stainless steel. In particular, the sensor portion 24 is formed as a non-magnetic sleeve 25. At least one magnetic field generator 26, which may be configured in the form of a permanent magnet, and a magnetic field sensor 28, which may be mounted together on a holder, are jointly arranged in the sensor section 24. The magnetic field generator 26 is designed to provide a magnetic field, preferably a static one, at the location of the rotatable object 12

Magnetic field, which induces eddy currents in the rotatable compressor wheel 14. The magnetic field sensor 28 may be configured as a coil. The magnetic field sensor 28 is provided for detecting a magnetic field generated by eddy currents of the rotatable compressor wheel 14. In the sensor section 24 may further include

Temperature sensor 30 may be arranged. An electrical connection, in particular electrical leads 32, and / or connecting elements, in particular plug contacts, can, as well as, the temperature sensor 30, the magnetic field sensor 28 and the

Magnetic field generator 26 may be arranged in the sensor section 24. The leads 32 are connected to a circuit carrier 34, such as a printed circuit board, which is located in a housing interior 36. The circuit carrier 34 may

For example, carry a drive and / or evaluation circuit. Furthermore, an amplifier for amplifying the signals supplied by the temperature sensor 30 and / or magnetic field sensor 28 may be arranged on the circuit carrier 34. An output of the control and / or evaluation circuit is connected to a control unit, not shown, such as an engine control unit. The magnetic field generator 26 may be aligned along an axis 38 which coincides with a longitudinal axis 40 of the sensor portion 24. The sensor section 24 may be formed, for example, rotationally symmetrical about the longitudinal axis 40.

In particular, the sensor section 24 protrudes from an underside 42 of the sensor housing 22 substantially perpendicularly. The bottom 42 may, for example, as

Support surface 44 may be formed with the in a state in which the

Sensor device 10 on a rotatable object 12 receiving device 46 is mounted, the sensor housing 22 on the device 46 at least partially rests. The sensor section 24 may, in particular, protrude from a projection 48 on the underside 42 of the sensor housing 22, which surrounds the sensor section 24 in sections, ie not over the entire length of the sensor section 24, coaxially. The projection 48 may be part of or formed as a mounting bush, which may be integrated into the sensor housing 22. The projection 48 is designed for centering the sensor housing 22 in the device 46. The projection 48 may surround the sensor portion 24 coaxially and thus supported in the radial direction. The projection 41 may also be part of or formed as a mounting bush, which may be integrated into the sensor housing 22. For example, the projection 41 may be a sleeve made of metal, which is encapsulated in plastic and provided with an external thread, which is designed for screwing the sensor housing 22 into the device 40.

As shown in FIG. 2, the rotatable article 12 is disposed or received within a device 46 that includes a compressor housing 50. The

Compressor housing 50 may be at least partially made of a cast aluminum alloy. Furthermore, in FIG. 2, an arrow 52 indicates a possible mounting position of the sensor device 10 on the compressor housing 50. As shown in FIG. 3, an exhaust-gas turbocharger 18 generally comprises a turbine wheel 54 which is drivable by flowing exhaust gas and is connected to the axis of rotation 20, with the turbine wheel 54 simultaneously rotating the compressor wheel 14, which likewise rotates with the axis of rotation 20 connected is. Also in Figure 3 is the possible

Mounting position of the sensor device 10 to the compressor housing 50 indicated by the arrow 52.

As shown in Figure 4, the compressor housing 50 has a receptacle 56 which is formed in the shape of a blind hole. To mount the sensor device 10 on the compressor housing 50, the sensor section 24 is inserted into the receptacle 56, wherein between a remote from the sensor housing 22 end 58 of the sensor portion 24, which is a front end 60 of the sensor portion 24, and a portion 62 of the wall of the Compressor housing 50 a gap 64 in the direction of the longitudinal axis 40 of the sensor portion 24 is located. For example, the gap 64 may have a dimension in the direction of the longitudinal axis 40 of the sensor portion 24 of 0.2 mm to 0.3 mm. The air in the gap 64 between the part 62 of the wall of the compressor housing 50 and the front end 60 of the sensor portion 24 can cause thermal insulation, since air has a lower thermal conductivity than the aforementioned materials of the compressor housing 50 and the sensor section 24. Further, between the sensor portion 24 and the receptacle 56 defining wall portions of the compressor housing 50 may be formed a coaxial gap, which also serves the thermal decoupling and can extend over the entire or part of the length of the sensor portion 24 in the direction of the longitudinal axis 40. For final assembly, the sensor housing 22 is fastened to the compressor housing 42 by means of a fastening means 66. This fastener 66 may

be formed for example in the form of a screw 68 which is inserted through a flange 70 on the sensor housing 22 therethrough. In the flange 70, for example, a sleeve made of metal or brass may be introduced, such as by

Overmolding with plastic, wherein the sleeve is arranged to prevent the screw 68 presses when screwing directly on the plastic of the sensor housing 22 and the flange 70.

As shown in FIG. 5, the compressor housing 50 is embodied such that a surface 72 of the sensor housing 22 facing the compressor wheel 14 has a curved course, preferably a curved course adapted to a curvature of the compressor wheel 14. A curved course is to be understood as a non-planar course. An adapted course is to be understood as a course in which a distance between the surface 72 and the rotating compressor wheel 14 is designed to be substantially constant in at least one direction on the surface 72 over at least a certain distance or area, for example by passing this distance over a distance of at least 1 cm,

preferably at least 2 cm, does not vary by more than 20%, preferably by not more than 10%. The distance between the surface 72 and the rotating compressor wheel 14 may be, for example, 0.05 mm to 0.3 mm, and preferably 0.1 mm.

FIG. 5 also shows that the part 62 of the wall of the compressor housing 50 is located between the receptacle 56 and the compressor wheel 14. The portion 62 may have a dimension d in the direction of the longitudinal axis 40 of the sensor portion 24 of 0.1 mm to 2 mm, preferably 0.2 mm to 1, 8 mm, and more preferably 0.5 mm to 1 mm,

for example, of 0.5 mm and is chosen to be as small as possible in order to minimize disturbing influences on the magnetic field detected by the magnetic field sensor 28. In other words, it is desired that a through eddy currents of the rotatable

Subject 12 generated magnetic field as possible with little or no attenuation can be detected by the magnetic field sensor 28. The receptacle 56 may in particular be designed so that the front end 60 of the sensor section 24 is positioned as close as possible to the passing compressor blades of the compressor wheel 14. Furthermore, FIG. 5 shows that the sensor section 24 can be attached to the compressor housing 50 such that the longitudinal axis 40 is at an angle α of 25 ° to 65 °, preferably 30 ° to 60 ° and more preferably 45 °, for example exactly 45 ° °, is arranged to the rotation axis 20. Due to the portion 62 of the wall of the compressor housing 50, the influence of the magnetic field generated by eddy currents of the rotatable article 12 decreases with increasing dimension d in the direction of the longitudinal axis 40, which may also be referred to as thickness. Therefore, the sensor device 10 may include a signal amplifier mounted or contained on the circuit carrier 34. As a result, the detected magnetic field and, for example, the voltage signal associated with this magnetic field is amplified. Without amplifiers, it would be possible, for example, that only voltages in a range of a few mV can be tapped off at the magnetic field sensor 28. Due to the amplifier, however, voltages of several volts, for example 5 V to 12 V, can be tapped for an accurate evaluation.

In the sensor device 10, the detection of the rotational property of the rotatable object 12 may be based on the fact that the magnetic field generator 26 generates a magnetic field, in particular a static magnetic field, at the location of the rotatable object 12. Upon rotation, in particular rotation of the rotatable article 12, here a

Compressor 14 is rotated about the rotation axis 20, in particular rotates, eddy currents are generated, which influence the magnetic field and in particular the magnetic flux, in particular change. The voltage which can be tapped on the magnetic field sensor 28 is the time change of a magnetic flux at the

Magnetic field sensor 28 proportional.

In the sensor device 10 according to the invention, a signal of the temperature sensor 30 can be transmitted separately from a signal of the magnetic field sensor 28 from an output of an evaluation circuit on the circuit carrier 34, which can be configured as a printed circuit board, to, for example, an engine control unit. This can be made possible by an additional pin that passes the signal to the engine control unit. The mass, i. Voltage potential of the speed sensor as common

Ground connection, i. as an electrical connection for transmitting the voltage.

Alternatively, a modulation of the signal of the detected by the temperature sensor 30 Temperature value on the supplied from the magnetic field sensor 28 signal the speed of the compressor wheel 14 possible. This can be done by a pulse width modulation method or a multiplexing method. For example, a speed information provided by the magnetic field sensor 28 can be sent as a rectangular signal to a not shown

Motor control unit are passed, the period or frequency evaluation can be set as needed. As mentioned, there is additionally the possibility of transmitting the temperature information, for example via pulse width modulation, via the signals supplied by the magnetic field sensor 28 and integrated electronics. A corresponding correlation of the temperature / pulse width can be done via software functions. Alternatively, depending on the design and complexity of the in the

Sensor device 10 integrated electronics also an intelligent interface, such as single-edge nibble transmission (SENT) or controller area network (CAN), providable, by means of which the information can be transmitted. A

Transmission of the temperature signal by means of the pulse width modulation offers the advantage that the sensor device delivers a real-time signal of the rotational speed and thus

Runtime losses of the signal processing can be avoided.

The temperature sensor 30 thereby detects directly the temperature of the compressor housing 50. Accordingly, no additional components except the actual

Temperature sensor 30 in the exhaust gas turbocharger 18 is required. Also, no additional wiring in the vehicle or on the engine for a temperature measurement is required.

As a result, for example, an intake temperature of the intake air after the compressor 16 can be determined indirectly. This can be used as an additional control quantity for

Air density correction in an engine control unit will be helpful.

It is explicitly emphasized that all features disclosed in the description and / or claims are considered separate and independent of each other for the purpose of original disclosure as well as for the purpose of limiting the invention

claimed invention independent of the feature combinations in the

Embodiments and / or the claims should be considered. It is explicitly stated that all range indications or indications of groups of units disclose every possible intermediate value or subgroup of units for the purpose of the original disclosure as well as for the purpose of restricting the claimed invention, in particular also as the limit of a range indication.

Claims

Claims 1. Sensor device (10) for non-contact detection of at least one

Rotational property of a rotatable object (12), in particular for detecting a rotational speed of a compressor wheel (14) of a turbocharger (18), wherein the

Sensor device (10) at least one sensor housing (22), wherein the sensor device (10) further comprises at least one magnetic field generator (26) for generating a magnetic field at the location of the rotatable article (12) and at least one magnetic field sensor (28) for detecting a by eddy currents the magnetic field generated by the rotatable object (12), wherein the

Sensor device (10) further comprises at least one temperature sensor (30), wherein the magnetic field generator (26) and the magnetic field sensor (28) at least partially together in a sensor portion (24) of the sensor housing (22) are arranged

characterized in that

the temperature sensor (30) is at least partially disposed in the sensor section (24).

2. Sensor device (10) according to the preceding claim, wherein the

Sensor device (10) comprises an evaluation circuit and a signal of the

Temperature sensor (30) separated from or together with a signal of

Magnetic field sensor (28) from an output of the evaluation circuit is transferable.

3. Sensor device (10) according to the preceding claim, wherein the signal of the temperature sensor (30) together with the signal of the magnetic field sensor (28) from the output of the evaluation circuit is transferable and by means of a

Modulation method to the signal of the magnetic field sensor (28) is modulated.

4. Sensor device (10) according to the preceding claim, wherein the signal of the temperature sensor (30) by means of pulse width modulation or by means of a

Multiplexverfahren on the signal of the magnetic field sensor (28) is modulated.

5. Sensor device (10) according to claim 2, wherein the signal of the temperature sensor (30) separated from the signal of the magnetic field sensor (28) from the output of Evaluation circuit is transferable and the evaluation circuit has an additional terminal which is adapted to transmit the signal of the temperature sensor (30).

6. Sensor device (10) according to claim 2, wherein the signal of the temperature sensor (30) separated from the signal of the magnetic field sensor (28) from the output of the evaluation circuit is transferable and the evaluation circuit has an intelligent interface, which is used to transmit the signal of the magnetic field sensor ( 28) is set up.

7. Sensor device (10) according to one of the preceding claims, wherein the

Temperature sensor (30) for detecting a temperature of a wall of a device comprising the rotary object (46) is formed.

8. Sensor device (10) according to one of the preceding claims, wherein the

Sensor section (24) is formed so that in a mounted on a rotatable object (12) comprising device (46) state of the

Sensor housing (22) between the sensor portion (24) and the rotatable object (12) in a direction substantially parallel to a longitudinal axis (40) of the sensor portion (24) is a part (62) of the device (46).

9. sensor device (10) according to the preceding claim, wherein the object (12) about an axis of rotation (20) is rotatable, wherein the longitudinal axis (40) of the

Sensor section (24) in a mounted on the device (46) state of the sensor housing (22) at an angle (a) of 25 ° to 65 ° and more preferably from 30 ° to 60 ° and more preferably from 45 ° to the axis of rotation (20) is arranged.

10. Sensor device (10) according to one of the preceding claims, wherein the

Sensor device (10) comprises an amplifier which is arranged, one of the

Magnetic field sensor (28) amplify signal supplied.