CN103925956B

CN103925956B - Sensor device for determining at least one flow property of a fluid medium flowing in a main flow direction

Info

Publication number: CN103925956B
Application number: CN201410012320.9A
Authority: CN
Inventors: A·布里泽
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2013-01-11
Filing date: 2014-01-10
Publication date: 2019-12-17
Anticipated expiration: 2034-01-10
Also published as: ES2534704A2; FR3001033B1; CN103925956A; ES2534704R1; FR3001033A1; DE102013200344A1; ES2534704B1

Abstract

Sensor device for determining at least one flow property of a fluid medium flowing in a main flow direction, in particular the intake air quality of an internal combustion engine, wherein the sensor device has a plug-in sensor arranged in a flow guide tube, which plug-in sensor has a sensor for determining the flow property of the fluid medium and at least one inlet opening facing the main flow direction, and at least one vane grating arranged upstream of the plug-in sensor in the main flow direction, wherein the vane grating has a plurality of vanes and webs for deflecting the fluid medium into the main flow direction at the plug-in sensor, wherein the vanes are arranged at least in sections in a circular, elliptical or variable radius, wherein the vanes are arranged such that they have an angle of 0 ° to 90 ° for reducing the air flow fluctuations and for generating a uniform high flow velocity at the plug-in sensor, preferably 0 ° to 20 ° and particularly preferably 0 ° to 10 °.

Description

Sensor device for determining at least one flow property of a fluid medium flowing in a main flow direction

Technical Field

A large number of methods and devices for determining the flow behavior of a fluid medium, i.e. a liquid and/or a gas, are known from the prior art. The flow characteristic can be essentially any physical and/or chemical, measurable characteristic that characterizes and quantifies the flow of the fluid medium. They can relate here in particular to flow velocities and/or mass flows and/or volume flows.

the invention is described below with particular reference to a so-called hot-film air-quality meter, which is described, for example, in Konrad Reif: sensors in motor vehicles, first edition 2010, 146-. Such hot-film air quality meters are usually based on a sensor chip, in particular a silicon sensor chip, having a measuring surface over which a flowing fluid medium flows. The sensor chip usually comprises at least one heating element and at least two temperature sensors, which are arranged, for example, on a measuring surface of the sensor chip. The asymmetry of the temperature distribution detected by the temperature sensors, which is influenced by the flow of the fluid medium, can be used to infer the mass and/or volume flow of the fluid medium. Hot-film air quality meters are usually designed as plug-in sensors which are installed in a flow duct in a fixed or exchangeable manner. Such a flow duct may be, for example, an intake manifold of an internal combustion engine.

In order to be able to output an air quality signal with as little disturbance as possible for a hot-film air quality measuring device, it is important to supply the plug-in sensor with as uniform an inlet flow as possible through the bypass channel therein and in particular on the measuring surface of the sensor chip. The bypass channel is here a measurement channel in which a sensor holder with a sensor chip is mounted. The sensor chip is provided with a diaphragm and a temperature sensor.

In internal combustion engines, the flow duct is usually located at the outlet of the air filter. The outlet of the air filter thus corresponds to the inlet of the flow guide. Strong deflections are frequently present during the flow through the air filter from the unfiltered air side to the flow duct provided with the hot-film air mass meter. In particular, in the region of the entry of the flow guide, there is a region with a lower flow velocity in the vicinity of the wall of the flow guide. Accordingly, the gas flow lines are strongly deflected and distributed in the vicinity of the guide pipe wall so as not to be parallel to the axis thereof. In this case, regions with low flow velocities can occur in the region near the wall or even lead to a detachment of the gas flow with the backflow region. Such a change in the velocity field will always affect the core region of the air flow and can occur in particular in full jumps at different air mass flows. Poor signal repeatability and increased signal noise are obtained due to changes in the fluid field near the inlet and outlet of the hot film air quality gauge. In addition, the pressure drop is increased by this gas flow disengagement.

Fig. 1 shows a conventional sensor device 10 for determining at least one flow characteristic of a fluid medium flowing in a main flow direction 18. In this exemplary embodiment, the sensor device 10 is designed as a hot-film air mass meter and comprises a plug-in sensor 12 which can be inserted, for example, into a flow duct, in particular into an intake manifold of an internal combustion engine. In the plug-in sensor 12, a channel structure 14 is received, which can be used to flow a representative quantity of the fluid medium via an inlet 16, which in the inserted state faces the main flow direction of the fluid medium. The channel structure 14 has a main channel 20 which opens into a main flow outlet 22 on the lower side in the view of the plug-in sensor 12 in fig. 1, and a bypass or measuring channel 24 which branches off from the main channel 20 and opens into a bypass or measuring channel outlet 26 which is also arranged on the lower side in the view of the plug-in sensor 12 in fig. 1. A sensor holder 28 with a generally rectangular cross section and a rounded front edge projects into the measuring channel 24, which front edge is generally directed, i.e. in addition to the backflow situation, against the fluid medium flowing into the measuring channel 24. A sensor chip 30 is inserted into the sensor holder 28 in such a way that a sensor diaphragm 32, which forms the sensor region of the sensor chip 30, is flowed over by the fluid medium. The sensor membrane 32 forms the actual sensor, i.e. it is a component which detects or determines the parameter to be measured. The sensor holder 28 with the sensor chip 30 is part of an electronic assembly 34. The electronic module 34 has a bent base plate 36 and a printed circuit board 38 which is mounted thereon, for example glued thereto, and which has a control and evaluation circuit 40. The sensor holder 28 can be injection molded onto the base plate 36 as a plastic component, for example. The sensor chip 30 is electrically connected to the control and evaluation circuit 40 via electrical connections 42, which can be formed as a conductor bundle. The electronic component 34 thus formed is fitted, for example glued, in an electronic chamber 44 in a housing 46 of the plug-in sensor 12, the channel structure 14 being formed in association with a feature of a cover 48 formed therewith. The assembly is carried out in that the sensor holder 28 projects into the measuring channel 24. The electronics chamber 44 and the channel structure 14 are then closed with a lid 48.

Fig. 2 shows the arrangement of the plug-in sensor 12 in a flow duct 50 and its installation position next to an air filter 52 in the intake manifold of an internal combustion engine. The flow region of the intake air and its deflection between the air filter element 54 and the inlet region 56 to the flow duct 50 or the sensor device 10 are indicated by arrows in particular. From this figure it can be seen that: there is a flow area 58 of the intake air which experiences a sharp deflection of up to almost 180. As can be seen from the diagram of fig. 3A, which represents the results of the air flow simulation calculations in the outlet region on the cleaned air side of the cleaned air duct or air filter on the right in fig. 3A and in the inlet region of the draft tube 50 on the left in fig. 3A, there is a region 62 with low flow velocity in the region of entry into the draft tube 50 near the inner side of the wall 60 of the draft tube 50 and the air flow lines extend, in particular near the wall 60, non-parallel to the axis of the draft tube 50. The flow velocity in the region of the outlet of the cleaned air duct is relatively low by about 2m/s to 4m/s and increases in the direction of the flow guide tube 50. In the center of the flow guide, for example, a flow velocity of 18m/s to 20m/s is present. The corresponding flow speed values are not to be understood here as generally universal values for all sensor devices, but merely as relative differences in flow speed. Correspondingly, the meaning and absolute value of the high and low flow velocities relative to one another for the effect may vary from sensor device to sensor device.

Fig. 3B shows the velocity profile of the sensor device according to fig. 1 at the outlet of the air filter 52 or at the inlet of the flow guide tube 50. The velocity profile has a significant asymmetry. The flow lines in the vicinity of the wall leave the immediate vicinity of the wall 60 and form a velocity which is negative, i.e. directed against the main flow. The velocity profile is formed for a pressure rise in the flow direction. The velocity gradient at the wall 60 is initially also positive at the inlet 56. However, further downstream the velocity gradient will reach zero and the boundary layer flow is detached in this region 64. A recirculation zone is formed downstream of disengagement zone 64. There is a negative velocity gradient at the wall 60 and a negative velocity directed against the main gas flow. In principle, the velocity increases from the wall 60 toward the center of the draft tube 50.

Such a fluid distribution is unstable in time. The extension in the radial direction and in the main flow direction varies over time. This change affects the core region 65 of the fluid. Due to the change in the fluid region or the external fluid around the sensor forming the plug-in connection, which also occurs in the vicinity of the inlet and outlet of the branched channel structure 14, the throughflow of the channel structure with the main channel 20 and the bypass or measuring channel 24 changes. This results in poor reproducibility of the characteristic curve and increased signal noise. Furthermore, the pressure drop is increased by this fluid separation.

In order to achieve this reduction in unstable flow conditions and to homogenize the air flow at the air filter outlet or in the region of the intake of the flow duct, i.e. to achieve a strategy in which a combination of measures can be combined in order to increase the aerodynamic quality of the air flow in the region of the sensor device 10. In this case, different size factors for the fluid guidance or fluid deflection and for homogenizing the velocity distribution and reducing signal noise can be sought. But intervention by one or a combination of these measures should be accompanied by an acceptable pressure drop over the respective section. A fluid grid will cause momentum transfer perpendicular to the main flow direction 18 and also direct fast, far away from the wall fluid to the fluid region near the wall. In addition, small-scale turbulence is generated near the wall as a result of the grid-follow-up flow, as a result of which the tendency to detach is reduced both at the wall of the flow guide tube and at the plug-in sensor. This results in a stabilization of the overall velocity profile, which also stabilizes the volume of the fluid flowing through the bypass channel and finally over the sensor diaphragm. Such a gate is described, for example, in DE 102007060046 a 1.

DE 102007055193 a1 describes a grate in a flow duct, which has an annular grate region on the inner wall of the flow duct, wherein grate struts are arranged uniformly distributed in the circumferential direction at an angle of attack of 5 ° to 60 ° relative to the main flow direction and a radial orientation.

Although the methods known from the prior art for homogenizing a fluid contain many advantages, these methods still have the potential for improvement. Strategies using, for example, a grid involve the challenge that, while a deflection of the gas flow is induced across the individual cells of the grid, this is accompanied by an undesirable pressure drop. This pressure drop is particularly critical if the fluid on the individual grid webs is detached due to a locally large angle of attack. In which case mixing occurs in the velocity-switching layer downstream of the grid. This, although leading to a reduction in the size of the flow straightening and of the swirl and thus to a certain homogenization of the gas flow, is associated with a large pressure drop. The length scale of the turbulence, i.e. the eddy current scale, is still in this case on the order of the external characteristic dimension of the plug-in sensor.

A smaller-scale mixing, i.e. a further reduction in the size of the vortex and thus a greater homogenization of the gas flow, can be achieved by the downstream wire screen, but this is associated with a greater pressure drop.

The design or configuration of the clean air side of the air filter, in particular the installation of one or more guide vanes, can contribute significantly to a reduction in the tendency of the fluid to deflect and disengage in the vicinity of the cylindrical housing wall of the hot-film air quality meter. This preparation also allows the local angle of attack on the individual grate webs of the air guide grate upstream of the hot-film air mass meter to be significantly reduced, which leads to a reduction in the pressure drop. And the fluid must be deflected in the transition region of the air filter from the curved pipe section to the flow guide pipe. As shown in fig. 4, however, eddy currents 66 are formed in this deflected free-wheeling flow and in the free-wheeling flow of the relatively coarse guide vane geometry, which eddy currents float in the flow region of the plug-in sensor that is important for measurement technology and can lead to strong fluctuations in the measurement signal due to the unstable secondary flow component. Cost considerations and tolerance issues during manufacture partially limit the convertibility of design measures on the clean air side of the air filter. Even in the case of a straight inlet flow without an air filter, strong fluctuations in the speed and angle of attack on the hot-film air mass meter, i.e. in the local direction of the speed relative to an imaginary plug-in sensor axis, can be formed.

Disclosure of Invention

An improved sensor device for determining at least one flow characteristic of a fluid medium flowing in a main flow direction is to be provided, which at least largely avoids the disadvantages of known methods and strategies or can be actively developed to complement the hydrodynamic measures and in which an aerodynamically effective deflection of the air flow and a low-disturbance of the inlet flow to the sensor device and at the same time a pressure loss as low as possible can be achieved.

in particular, a sensor device for determining at least one flow characteristic of a fluid medium flowing in a main flow direction, in particular of an intake air mass of an internal combustion engine, is thus provided. The sensor device has a sensor arranged in a flow-conducting tube and having a sensor for determining the flow behavior of the fluid medium and a plug-in sensor having at least one rib arranged upstream of the plug-in sensor in the main flow direction. In this case, the winged grating can have different distances from the plug-in sensor, as viewed in the main flow direction. The rib grating has a plurality of ribs and webs for deflecting the fluid medium in the main flow direction at the plug-in sensor. The wings are at least in sections arranged in a circular, elliptical or variable radius. The wings are arranged in such a way that they have an angle of attack of 0 ° to 90 °, preferably 0 ° to 20 ° and particularly preferably 0 ° to 10 °, in order to reduce the flow fluctuations and to generate a uniform high flow velocity at the plug-in sensor.

The wings can be arranged, for example, in a circle such that they can define at least one center point of a circle or a circular arrangement. The circular arrangement facilitates an installation in which the hydrodynamic parameters are only rarely correlated with the installation angle of the flow duct with the plug-in sensor relative to the air filter. The wing may have an elevation angle decreasing from the outside towards the center point.

The louvres can be at least partially placed against the inner side of the wall of the flow duct or can be integrated into the flow duct by injection moulding. The wings may be interconnected by tabs.

The wings can be curved at least in sections, as seen in the main flow direction. For example, the wings are shaped as supporting surfaces. In particular, the wings and/or the webs have a wing cross section and a web cross section which form the wing contour.

The wing profile may have a non-uniform thickness and curvature or curvature as seen in the main flow direction. The thickness distribution and the camber distribution can in particular correspond to the wing profile known from the aeronautical field.

The wings may be arranged such that they form between themselves converging channels, converging-diverging or diverging channels.

The length of the wings in the main flow direction may vary. For example, each wing may have a different length in the main flow direction. The wings can also be offset from one another in the main flow direction for the same length. In this case, the webs can have the length of the wings or a smaller or larger length in the main flow direction than the wings. This configuration is particularly preferred in the case of gas flows with strong spirals.

The wings have at least partially recesses, for example recesses of a modulated sinusoidal wave shape or rectangular or rounded, which extend in the circumferential direction or radial direction, in the front end region and in the rear end region, as viewed in the main flow direction.

The winged grate with its wings and webs can be produced together with the flow duct, in particular, by a single injection molding process, so that only one component is formed and the joining process of the winged grate to the flow duct is eliminated. The rib grid, which is produced as a single piece, can alternatively be connected to the inner side of the flow duct wall by caulking, bayonet connection, adhesive bonding or laser welding. The webs can have a thickness distribution, in particular, as viewed in the main flow direction. Bending is also contemplated for the butt-tabs. The winged grating can, for example, and with regard to its outer contour corresponding to the flow duct, form a ring or an ellipse. Other contours are also conceivable, such as angular shapes, in particular polygonal shapes, circular rings approximated by a plurality of angles or ellipses approximated by a plurality of angles. The rib grating may be located in the inlet region of the flow duct or at a distance from the inlet region of the flow duct upstream of the plug-in sensor. The wings and/or tabs of the winged fence may have a thickness of 0.2mm to 10mm, and preferably 0.4mm to 4 mm. The wings and tabs of the winged fence can have a thickness distribution, i.e. a thickened portion in the front and/or rear area or in the middle area or over the entire length or depth of the wing, as seen in the main flow direction, which can vary from 3 to 50mm, preferably from 5 to 20mm, for example as a continuously extending thickness variation. The profile of the wings and tabs of the winged fence may be curved and preferably have a radius of curvature of 0.1mm to 5000mm, a plurality of interconnected different radii of curvature or continuously varying radii or may be curved unevenly or have at least one point of inflection.

An additional, locally very limited shaping can be achieved in the form of a thickened portion in the region upstream in the main flow direction, i.e. in the region of the strongly curved suction side of the wings and/or webs. Different cross-sections and extensions perpendicular to the main flow direction are also conceivable, and discontinuous solutions are also conceivable.

The required mold separation for the die-casting process can preferably be realized in the region of the webs. In this case, steps and transitions can occur both in the main flow direction and in the radial and circumferential directions.

The invention is based on the idea of introducing or combining a cascade to a region of a component surrounding a sensor, such as a plug-in sensor of a sensor device for determining at least one flow characteristic of a fluid medium flowing in a main flow direction, in which the fluid is strongly deflected, the fluid parameter is subject to large instabilities or fluctuations, the time-averaged fluid parameter is subject to large inhomogeneities and the tendency for fluid to escape is large, to cause an aerodynamically effective fluid deflection, a reduction in the fluctuations of the fluid over time and a uniform distribution of the fluid parameter, a reduction in the sensitivity to inflow and a high flow velocity at the sensor, and at the same time a pressure drop as low as possible. The winged grating is composed of, in particular, wing-shaped and web-shaped interconnected profile parts. The invention therefore proposes a compromise between deflection, flow straightening, stabilization of the pipe flow near the wall, flow fluctuations and inflow sensitivity and a reduction in the pressure drop and has an embodiment on the sensor device side, for example a hot-film air quality meter, which is contrary to the possible embodiment on the air filter side.

This allows the fluid, in particular the fluid volume around a plug-in sensor of the type mentioned above, which is important for measurement purposes, to be pre-conditioned. And the generally temporally or spatially unstable fluid detachment at the inlet wall can be prevented or reduced by injecting a fluid having a high momentum from the core flow and a small-scale swirl component. In particular, longitudinal turbulence drifting away from the intake of the flow duct and from the air filter box, which has secondary velocity components that are detrimental to the sensor of the sensor device, should be prevented or reduced. In the event of contamination of the air filter and the associated change in the inlet flow of the plug-in sensor, a uniform, full and as little as possible fluctuating (large-scale) velocity distribution in the sensor device, in particular around the plug-in sensor, and particularly stable air flow conditions at the inlet and outlet of the channel structure are to be ensured. In general, by deflection, rectification, stabilization of the pipe flow near the wall, reduction of the air flow fluctuations, inflow sensitivity and pressure drop will prevent or reduce the time-varying velocity profile in the sensor device and thus lead to improved characteristic curve repeatability, low inflow sensitivity and low signal noise. The measure according to the invention furthermore makes it possible to reduce the influence of manufacturing-related geometric deviations in the area of the air filter and at the inlet of the flow duct and to facilitate the use of the same sensor characteristic curve in different air filter systems without updating the same. The sensor arrangement according to the invention and in particular the air foil grid according to the invention can be used without further additional components directly on the sensor inlet in a cost-effective and production-technically switchable manner and fills the gap in the possible, in particular hydrodynamic, intervention possibilities, for example air filter/guide vane systems, guide tubes/plastic grids and guide tubes/wire screens according to the prior art. The device according to the invention can therefore, for certain applications, replace or deliberately supplement the intervention possibilities of the prior art which are too strong or are associated with adverse side effects.

Certain essential functions should be satisfied by the present invention. The first function relates, for example, to a targeted deflection of the gas flow. The sensor device according to the invention can therefore be arranged, for example, downstream of an air filter in the intake manifold of an internal combustion engine. In this case, the deflection of the air flow from the clean air side of the air filter, i.e. downstream of the air filter, to the plug-in sensor in the form of a model-device combination tends to be on the plug-in sensor side, in contrast to the measures on the air filter side. This first function is effected, for example, by a plurality of wings or blades of sufficient length, curved or bent, for example, for distributing the aerodynamic loads on the low-pressure side of the wing. This is crucial especially in the case of strong air mass flows or momentum. The other influencing parameter is the thickness distribution along the shape of the supporting surface of each airfoil for a deflection with the lowest hydrodynamic pressure loss possible. In addition, the different thickness distribution on each wing and the different angle of attack for the inflow of each wing contribute to the first function. This results in an optimized flow guidance and a low pressure loss. Finally, the ring-shaped or segmented approximately ring-shaped wing grid configuration contributes to the mounting-rotation invariance and compensates for certain influences over the entire operating life. Furthermore, the spiral flow in the region between the air filter outlet and the plug-in sensor can be preconditioned by the tabs formed according to the above-described model device. In this case, asymmetrical and symmetrical webs can be considered.

The second function relates, for example, to the reduction of air flow fluctuations on the plug-in sensor. This function is assisted by converging-diverging channels, for example converging or having a modest increase in cross-section between the opposed wings in the form of a thickness distribution. This can result, for example, in acceleration, vortex development and reduced fluctuations. Furthermore, the decreasing angle of attack from the outside to the inside and the adapted thickness distribution contribute to this function. Thereby reducing the flow drop off at the leading edge of the airfoil. Recesses which can be rectangular or sinusoidal, for example, on the front and/or rear edge of the individual vanes and which have different depths, as seen in the main flow direction of the individual vanes, can lead to improved mixing and a reduction of the common vibration mode. This second function is also assisted by the positioning of the winged grating or at least the internal circular arrangement or the arrangement of the critical inlets and outlets of the plug-in sensors. Finally, an additional, locally very limited shaping can be achieved in the form of a thickened portion for the region upstream of the main flow direction, i.e. in the region of the front edge of the wing and in particular on the strongly curved suction side of the wing and/or of the web. Different cross sections and extensions perpendicular to the main flow direction, and discontinuous versions are conceivable for this. A transition (transition) of the air flow from laminar to turbulent flow conditions can thereby be achieved, which leads to a reduction of the flow separation on the strongly curved suction side of the wings and/or webs. This reduction in flow decoupling in turn leads to a reduction in the fluctuations in the air flow in the free-wheeling sections of the wings and tabs of the wing grid and in critical areas of the plug-in sensor.

The third function relates to a uniform high flow velocity at the plug-in sensor. This function is assisted, for example, by the orientation of the winged grating or the at least internal circular arrangement or the arrangement of the critical inlets and outlets of the plug-in sensors. A freewheeling tab shear layer in these critical regions will thereby be avoided. Furthermore, for example, the converging channel between the opposing wings in the form of a thickness distribution and the angle of attack that decreases from the outside to the inside contribute to this function. For example, the convergence can be set such that it increases from the outside to the inside. Notches on the trailing edge of each wing will result in improved mixing and a reduction in common vibration modes.

For the qualitative and/or quantitative detection of the properties of the fluid to be detected, reference is made, for example, to the above description of the prior art. These fluid properties may relate in particular to the fluid velocity and/or the mass flow and/or the volume flow of the fluid medium. The fluid medium may be a gas, in particular air. The sensor device can be used in particular in automotive engineering, for example in the intake manifold of an internal combustion engine. In principle, however, other fields of application are also possible.

The sensor device comprises at least one plug-in sensor. In the context of the present invention, a plug-in sensor is understood to mean a one-piece or multi-piece device which comprises a sensor chip with a real sensor, for example a sensor diaphragm, and which is at least largely closed to the outside and at least largely protected against mechanical effects and in particular also against other types of effects, for example chemical effects, contamination and/or moisture. The plug-in sensor can be inserted into a flowing fluid medium, wherein either an exchangeable insertion or a permanent insertion can be considered. The plug-in sensor projects, for example, into a flow duct of the flowing fluid medium, wherein the flow duct itself can be a component of the sensor device or can also be provided as a separate component, which has, for example, a bore into which the plug-in sensor can be inserted. The plug-in sensor can be produced, in particular, at least partially from a plastic material, for example by means of an injection molding method.

At least one electronic assembly having at least one fluid sensor for detecting a fluid property is received in the plug-in sensor. The term "receiving in a plug-in sensor" is understood here to mean: the electronics module is at least partially, preferably completely, surrounded by the plug-in sensor. The electronic assembly is at least partially arranged in at least one electronics compartment of the plug-in sensor. In the context of the present invention, an electronics chamber is understood to mean a partially or completely closed chamber within the plug-in sensor, which is closed in at least one direction by the plug-in sensor. The electronics compartment preferably comprises a recess in the plug-in sensor which is accessible at least from one surface of the plug-in sensor, for example a cuboid recess. As will be described in more detail below, the electronics compartment is accessible, for example, by a fitting, for example, from a surface, and can be permanently or reversibly closed by a closure member, for example, at least one electronics compartment cover.

A fluid sensor is understood here to mean, in principle, any sensor element which is provided to detect at least one flow characteristic. The fluid sensor may be, in particular, a micromechanical sensor membrane which is integrated into a sensor chip, for example, a sensor chip of the type described above. The sensor chip may comprise, in particular, a measuring surface which forms a micromechanical sensor membrane and over which a flowing fluid medium can flow. At least one heating element and at least two temperature sensors can be provided on the sensor surface, for example, wherein at least one flow characteristic can be inferred from the asymmetry of the temperature distribution detected by means of the temperature sensors, as described above. The at least one fluid sensor can be arranged, for example, on a sensor carrier of the electronics assembly, which sensor carrier projects into the flowing fluid medium. The electronic module can in particular be embodied as a single piece and can in particular carry a control and/or evaluation circuit which is provided for controlling the fluid sensor and/or for receiving signals from the fluid sensor.

Accordingly, the electronic component has, for example, at least one circuit carrier. In addition, the electronic assembly can have, in particular, at least one sensor carrier, which is preferably mechanically connected to the circuit carrier. The circuit carrier can be arranged, for example, in an electronics chamber of the plug-in sensor, and the sensor holder can project from the electronics chamber into the fluid medium. It is particularly preferred that the plug-in sensor has at least one channel through which a fluid medium can flow, wherein the sensor holder of the electronics assembly carrying the fluid sensor projects from the electronics chamber into the at least one channel through which the fluid medium can flow in the plug-in sensor. The at least one channel may in particular form a single part, but may also have at least one main channel and at least one bypass channel branching off from the main channel, wherein the sensor carrier preferably projects into the bypass channel, as is known per se from the prior art. The circuit carrier of the electronic module may comprise, for example, a printed circuit board, which may be used separately or may be mounted, for example, on a mechanical support, for example a stamped and bent part made of a metallic material. The sensor carrier can be connected directly to the circuit carrier or can also be connected to a carrier part, for example a stamped and bent part, for example by injection-molding the sensor carrier onto the stamped and bent part. Other configurations are possible. For example, it is conceivable for the electronic assembly to be produced from one printed circuit board material, wherein both the circuit carrier and the sensor carrier are produced from the printed circuit board material, preferably from one circuit board material. Alternatively or additionally, it is also possible to use injection-molded printed circuit boards known from the prior art for the electronic components, for example one or more so-called injection-molded printed circuit boards in MID technology (MID: molded interconnect device). Different configurations are also contemplated. The electronic module may in particular comprise a control and/or evaluation circuit for the at least one fluid sensor. The electronic assembly can comprise, in particular, a sensor holder, wherein the sensor holder supports the fluid sensor and projects from the electronic chamber into at least one channel of the plug-in sensors through which a fluid medium can flow. In principle, however, other configurations are also possible. For example, a perforation in a wall of the electronics compartment can be provided, which perforation connects the electronics compartment to the at least one channel, wherein the sensor holder projects through the perforation into the at least one channel. The electronics and sensor chambers can be accessed from the same side of the plug-in sensor or also from mutually opposite sides of the plug-in sensor, for example for accessories. The plug-in sensor has, for example, a substantially rectangular cross section in a plane perpendicular to the plug-in direction, with a front side facing the fluid and a rear side facing away from the fluid, wherein the sides can be arranged substantially parallel to the flow direction. These surfaces can in particular be rectangular longitudinal surfaces. The electronics compartment and the sensor compartment can be closed, in particular independently of one another, by a closure element, in particular at least one electronics compartment cover and/or at least one sensor cover. These covers can be latched or locked in some other manner, for example, to the plug-in sensor. Other types of closure elements are also conceivable alternatively or additionally to the cover structure.

in particular, the inlet opening can be provided such that the fluid medium can enter the sensor chamber unimpeded through the inlet opening. Alternatively, however, the at least one inlet opening may be completely or partially closed, for example by at least one membrane, in particular at least one moisture-permeable membrane, in particular a semi-permeable membrane. In principle, the at least one inlet opening can have any cross section, for example a rectangular and/or circular and/or polygonal cross section. And may be of other configurations. The at least one inlet opening can be arranged in particular in a sensor chamber cover of the plug-in sensor, wherein the sensor chamber can be at least partially closed by means of the sensor chamber cover.

The sensor device may furthermore comprise one or more further sensor elements for detecting at least one further physical and/or chemical property of the fluid medium.

The sensor device also has at least one winged grating, which is arranged upstream of the flow sensor in the main flow direction and whose wings and webs have an angle of attack on both sides, i.e. in the direction of and against the main flow direction, in the range from 0 ° to 90 °, preferably from 0 ° to 20 °, and particularly preferably from 0 ° to 10 °. The cascade can be designed in particular in sections as a ring and be arranged spaced apart from the inner side of the guide tube wall.

The term main flow direction is understood here to mean the average flow velocity over a flow cross section through the flow conduit at a certain point along the flow path, local irregularities or turbulences on components such as plug-in sensors, for example, being able to be disregarded. The main flow direction can be distinguished from a local, time-averaged flow velocity. The average time interval for determining the main flow direction is significantly greater than the time scale of the turbulence.

The angle of attack is understood to be the angle between the inflowing medium, for example the intake air, and the profile chord or profile depth of the wings or webs of the winged grating. The contour chord is the imaginary line of the contour element from a front middle point viewed in the main flow direction to a rear middle point viewed in the main flow direction.

The invention is positioned between relatively coarse measures in the flow technology on the air-cleaning side of the air filter, such as guide vanes, and small-scale measures, such as air quality sensor plastic grids or air quality sensor wire screens. To the extent that the improvement in the stability or reproducibility of the characteristic curve, the reduction in the inflow sensitivity, in particular in the case of particle contamination of the air filter and different geometric configurations of the air filter and the air guide part, the geometric tolerances of the front edge of the flow guide tube, the geometric tolerances of the flange region of the sensor inlet/air filter outlet, the geometric tolerances of the flow guide part of the air filter into the clean air guide region of the sensor, is satisfactory in comparison with the aerodynamic rough measures or no measures on the clean air side of the air filter or on the sensor inlet side, the invention is embodied as an intermediate step or as a compromise in comparison with the measures known and used hitherto. The above-described embodiments also apply to the satisfaction of the implementation that is feasible in terms of manufacturing technology with regard to the reduction of signal noise, the smallest possible additional pressure drop, in particular the additional pressure drop that is smaller compared to plastic grids or even wire mesh screens, and the costs associated with the overall system comprising the air filter, the air guide and the sensor that are as advantageous as possible.

Drawings

Further optional details and features of the invention may be obtained from the following description of preferred embodiments, which are schematically represented in the drawings.

The attached drawings show that:

FIG. 1: a conventional sensor device for detecting at least one flow characteristic of the fluid medium;

FIG. 2: a conventional mounting position of a sensor device for detecting at least one flow characteristic of a fluid medium on an air filter;

FIG. 3A: results of simulation calculations in the case of a conventional sensor device in a draft tube region;

FIG. 3B: the velocity distribution in the flow conduit of conventional sensor devices in a plane perpendicular to the flow conduit;

FIG. 4: a cross-sectional view of a plug-in sensor with a conventional sensor device as shown and a vortex-dragged flow conduit;

FIG. 5: viewed in the main flow direction, one embodiment of the sensor device according to the invention for detecting at least one flow property of a fluid medium;

FIG. 6: a perspective cross-sectional view of a sensor device for detecting at least one flow characteristic of a fluid medium along line a-a in fig. 5;

fig. 7A and 7B: a different position of the fence according to the invention in a draft tube is shown in a sectional view according to a part of line B-B in fig. 5;

FIG. 8: a cross-sectional view according to line C-C in FIG. 5;

Fig. 9A to 9I: possible alternative configurations of the wings of the winged fence:

FIG. 10: a cross-sectional view of a winged-grid according to another embodiment;

FIG. 11: a perspective view of a winged fence according to another embodiment;

FIG. 12: a perspective view of a winged fence according to another embodiment;

FIG. 13: a perspective view of a winged fence according to another embodiment;

FIG. 14: a cross-sectional view of one of the winged-gratings according to another embodiment;

Fig. 15A to 15E: a top view of the wing of figure 14 according to a possible variant of the wing; and

FIG. 16: for the purpose of explaining the cross-sectional view of one wing of the concept used.

Detailed description of the preferred embodiments

Fig. 5 shows an embodiment of a sensor device 100 according to the invention for determining at least one flow characteristic of a fluid medium flowing in a main flow direction, in particular of an intake air mass of an internal combustion engine. Components identical to those of the conventional sensor device are provided with the same reference numerals.

the sensor arrangement 100 comprises a hot-film air mass sensor in the form of a plug-in sensor 12 in a plastic injection-molded flow duct 50 which is part of an intake manifold of the internal combustion engine downstream of an air filter, not shown. Other types of fluid sensors are also contemplated. The hot film air quality gauge corresponds to a commercially available air quality sensor model HFM7 from Robert Bosch limited, germany. The plug-in sensor 12 projects into the fluid medium in the flow guide tube 50.

Although, for reasons of clarity, a channel region with at least one channel through which a fluid medium can flow and an electronics region with an electronics chamber opening in the plug-in sensor 12 are received in the plug-in sensor 12, as in the case of the conventional sensor device 10. The channel has, in terms of it, a main channel and a bypass channel. An electronic module is received in the electronics compartment, which electronic module comprises a circuit carrier with a control circuit and/or evaluation circuit, which circuit carrier can be received on a base plate. The electronics assembly also includes a sensor mount in the form of a wing molded onto the base plate, which sensor mount extends into the bypass channel. A fluid sensor in the form of a hot-film air mass measuring chip is inserted into the sensor holder. The plug-in sensor 12 may furthermore comprise a cooling opening which extends into the electronics compartment.

In the configuration according to fig. 5 of a commercially available sensor device 100, the sensor carrier and the base plate form a unit which is referred to as an electronic module and which, for example, in this or in other embodiments can comprise a control and/or evaluation circuit for the control and/or evaluation of the fluid sensor. In addition to the fluid sensor, the electronics of the circuit carrier and the control and/or evaluation circuit are also bonded to the base plate. The fluid sensor and the control and/or evaluation circuit are usually connected to one another by a welded connection. The electronic assembly thus formed is for example glued in an electronic compartment and the entire plug-in sensor is closed by a cover. The plug-in sensor 12 has a sensor chip.

The plug-in sensor 12, which as described has a hot-film air mass meter, is located in a flow duct 50 of the intake manifold of the internal combustion engine, wherein a plug region 68 provided for electrical connection is arranged outside the flow duct 50. The insertion region 56 has a flange 70 with two drilled holes 72, as seen in the main flow direction 18, outside the wall 60 of the flow guide tube 50. The flange 70 is used to secure the delivery tube 50 to the air filter 52. In this case, the flange can be screwed to a corresponding flange in the outlet region of the air filter by inserting screws through the holes 72 and fastening them with a locking nut.

Upstream of the plug-in sensor 12, there is a wing grating 74. The wing grid 74 has a plurality of wings 75 and tabs 76. The wings 75 may be arranged circularly at least in sections. The louvered grating 74 is located immediately on the inside of the wall 60 of the draft tube 50. For example, in the case of a separate production of the flow duct 50 from the rib grid 74, an external connecting element 77 extends in the circumferential direction parallel to the inside of the wall 60 of the flow duct 50 and abuts against and is connected to this wall. The connection can be realized by welding, caulking connection, clamping groove connection, bonding and the like. The translating louvres 74 may be injection molded as one piece with the draft tube 50. The individual wings 75 and tabs 76 are spaced apart from each other, wherein the wings 75 are connected to each other by the tabs 76. The wing grating 74 may be located at a distance from the inlet region 56, as shown in fig. 7A, i.e. downstream of the inlet region 56, as seen in the main flow direction, depending on the particular application of the respective sensor device 100. For example, a steel connection 50a is provided upstream of the rib 74, so that the radius of the front edge of the inlet region 56 is designed to be sharper than in the case of injection molding of plastics in bulk. The difference in the radius of the front edge, particularly in the case of a strong deflection of the fluid in front of the flow conduit 50 and the absence of a cylindrical front edge, leads to a change in the fluid disengagement distribution, which in turn has an effect on the fluid distribution generated in the flow conduit. The alternating winged grating 74 may be disposed directly in the inlet region 56 of the draft tube 50, as shown in fig. 7B. Details of the winged-grating 74 and the tabs 76 will be described in detail below.

fig. 7A and 7B show a section of the cross section along the line B-B of fig. 5 and fig. 8 shows a section of the cross section along the line C-C of fig. 5. This section extends in particular through the web 76 according to the view of fig. 5.

The webs 76 have a uniformly curved contour which tapers in the main flow direction of the air mass flow toward the plug-in sensor 12. The tabs 76 transition to the winged fence 74 and may be integral with the winged fence 74.

The louvered grating 74 has fins 75 for deflecting the fluid medium into the main flow direction 18. In other words, the fluid medium flowing from the air filter 52 to the wing grate 74 and possibly having a flow direction deviating from the main flow direction 18 at the location of the plug-in sensor 12 is deflected by the wings 75 of the wing grate 74 into the main flow direction 18. In this case a flow straightening of the fluid takes place. The wings 75 may be arranged at least in sections in a circle, oval or according to other shapes, for example with variable radii. In other words, the wings 75 do not necessarily always extend as a complete circle or other complete shape in the circumferential direction, but rather the wings are formed as circular segments or shaped segments in a plane perpendicular to the main flow direction 18. In which case the sections may have different lengths in a plane perpendicular to the main flow direction 18. For example, the wings 75 are formed in a plane perpendicular to the main flow direction 18 as circular segments having a length of a quarter circle, a half circle, a third circle or a length in between. The circular segments need not be adjacent to one another in the circumferential direction, but can be arranged at least partially offset from one another. The individual wings 75 are likewise connected to one another by tabs 76. The innermost wing 78 may, for example, be formed as a complete circle. The innermost wing 78 need not have its circular shape disposed at the radial center of the draft tube 50. In particular, an imaginary line 79 in the main flow direction 18 can extend through or offset from the center 80 of the circle of the innermost limb 78 and the inlet 16 of the plug-in sensor 12. The wings 75 may thus for example be arranged in a circle, so that they define at least one centre point of the circle or circular arrangement. Each wing 75 may have a different or multiple radii. The center point of the circle of the wings 75 described by these radii can be on a connecting line 79 with a point of the inlet 16 on which the axis of rotation of the draft tube 50 lies or is offset thereto. For example, a plurality of center points 80a, 80b, etc., which are offset from one another, can be formed by the radially inner and radially outer wings 75. Due to the skin effect, depending on the embodiment of the plug-in sensor 12 and the embodiment of the innermost wing 78 or the type of specific application on the air filter 52, the distance of the aforementioned center point 80 from the center point of the flow duct 50 can be set such that the reference point is not realized by a purely geometric projection, for example, on the center of the plug-in sensor inlet region. At the entry of the cascade, the vanes 75 also have an angle of attack of 0 ° to 90 °, preferably 0 ° to 20 ° and particularly preferably 0 ° to 10 °, with respect to the main flow direction 18.

Reference is now made to fig. 16 for the purpose of explaining the concepts used in connection with one of the wings 75. FIG. 16 shows a cross-section of an exemplary bearing surface shape for airfoil 75. As shown in fig. 16, at least the following profile data may be defined on the wings 75 of one supporting surface shape. A profile chord or profile depth 75a is the longest straight line from a profile leading edge 75b to a profile trailing edge 75. One skeleton line 75d is composed of a midpoint between the upper side 75e and the lower side 75f taken perpendicular to the contour chord 75 a. One profile camber 75g is the maximum offset of the skeleton line 75d from the profile chord 75 a. One profile thickness 75h is the largest possible circle diameter on the skeleton line 75 d. An angle of attack α is the angle between the inflowing medium, for example the intake air, which is indicated by the arrow 75i, and the profile chord 75 a.

The vanes 75 are arranged, for example, such that the angle of attack α of the flow velocity reduction vanes 75 decreases from the outside in the direction of the center point 80 of the circle of the innermost vane 78, as will be explained in more detail below.

Fig. 6 shows a perspective cross-sectional view along the line a-a in fig. 5. Wings 75 are formed between the channels 81. These channels 81 can be formed convergent in the main flow direction 18. In this case, the distance of the wings 75 in the direction perpendicular to the main flow direction 18 decreases with increasing position, as seen in the main flow direction 18. For example, the convergence is enhanced from the outside to the inside in order to produce a uniform, high flow velocity. That is to say that the radially outer channels 81a have a smaller convergence rate than the radially inner channels 81b in particular.

According to the view of fig. 8 the winged fence 74 or wing 75 has a curved arch profile of constant thickness except for a profile leading edge 75b and a profile trailing edge 75 c. The transform ground plane 75 may have a non-uniform thickness, as will be described in detail below. The geometrical parameters of interest on the airfoil 75 and on the tab 76 are also the profile leading edge radius and the trailing edge thickness.

The wings 75 are formed in the shape of a support surface, for example. The front end region 82 and the rear end region 83, viewed in the main flow direction 18 of the air mass flow, each have a rounded corner 84. The angle of attack α is between 0 ° and 90 °. Preferably in the range from 0 ° to 20 ° and particularly preferably in the range from 0 ° to 10 °. This angle depends in particular on the application of the sensor arrangement 100 and can vary depending on the installation location, for example in the region of the intake manifold of an internal combustion engine. An excessively large angle of attack α for various reasons in the case of a linear inflow, for example in a post-production setting operation, is disadvantageous at least for the inner wing 75 of the cascade 74. In principle, the following steps are carried out: when the angle of attack α is too large the airflow on the suction side or upper side 75e of the airfoil 75 can be detached, which will lead to a reduction of the deflection angle and an increase of the pressure drop. The wings 75 may have a non-uniform thickness of about 0.2mm to 10 mm. The radius of the camber of the wing 75 may be in the range of 0.1mm to 5000 mm. The shear layer of the air mass flow generated downstream of the winged grating 74 by the special configuration of the wings 75 produces sufficient mixing with a small pressure drop, so that a uniform air flow is imparted to the hot-film air mass sensor and its sensor elements.

the shape of the wings 75 of the fixed-wing grill 74 may be modified depending on the installation site and application, as shown in fig. 9A to 9I. Possible configuration shapes of the wings 75 may be enumerated in their number without end. For example, an arch of curvature, as shown in fig. 9B, is not absolutely necessary, but it is also conceivable to replace it by a straight extent in the main flow direction 18, as shown in fig. 9A. The wings 75 may have an angle of attack a of 0 ° to 90 °. For example, the radially outer wing 85 has a larger angle of attack α of, for example, 20 °, while the radially inner wing 86 has a smaller angle of attack α of, for example, 5 °. If the angle of attack α is too large, the air flow on the suction side or upper side of the airfoil 75 will be detached, which will lead to a decrease in the deflection angle and an increase in the pressure loss. Wing profiles with camber generally dominate profiles without camber, but may not be achievable or preferred in terms of manufacturing technology or cost. The webs 76 which are oriented radially for the most part are symmetrical for reasons of symmetry in order to be widely applicable for various applications or in the case of gas flows with a spiral, a symmetrical, i.e. non-arched profile is usually used.

Wings 75 without fillets 84 on the ends are also contemplated, and in particular wings 75 of a parallelogram as shown in fig. 9C or curved arch without fillets 64 as shown in fig. 9D may be contemplated. Thickened portions 87 in the region of the front end region 82 and/or the rear end region 83 viewed in the main flow direction 18 along the contour chord 75a, as shown in fig. 9E and 9F, are also conceivable. The thickened portion in the front end region 82 and/or the rear end region 83 therefore corresponds to a reduction in the effective cross section of the flow guide tube 50, which can lead to an acceleration of the gas flow. Separation of the gas streams is thereby avoided. A thickened portion 87, for example, with an acute angle, in the rear end region 83 can lead to a targeted separation of the gas flows. This results in a wide, strong thorough mixing of the gas flow downstream of the cascade 74 and homogenization of the velocity distribution.

The filling 75 may have a discontinuous extension in its extension in the main flow direction 18. Such an extension may be realized, for example, in the form of an inflection point 88. This variant may be considered for injection molding reasons. The wing depth, i.e. the extension along the wing gate, is also a parameter in all solutions. The wings 75 may thus have different depths or lengths in the main flow direction 18. The radially outer wing 85 may be longer than the radially inner wing 86. This configuration of wings 75 with different depths or lengths will result in better thorough mixing and a reduction in common vibration modes. In this case, depending on the desired deflection and the additional conditions of taking into account the air flow against the wing grate 74, wings 75 with a large radius of curvature and a large wing depth can be produced, wherein not only the wing depth can be 3mm to 50mm but also the radius can be in the order of 0.1mm to several thousand mm.

As shown in fig. 9H and 9I, the rear end 83 of the vane 75 in the region of the main flow direction 18 may have notches 90 or grooves of different depths, which may lead to a more intensive and thorough mixing of the shear layer downstream of the vane grating 74 and to a small-scale, relatively positionally stable turbulence in the main flow direction 18. In a corresponding design, the turbulence stabilizes the gas flow. A plurality of wing bars 74 can likewise be provided, the distance of which from one another and from the other components can be selected at will. The winged grating 74 can be composed in particular of metals, metal compounds and alloys thereof or plastics, for example glass-fiber-reinforced plastics, so that it can be produced cost-effectively. The shape of the winged grating 74 may also be adapted to the cross section of the draft tube 50 and may thus be square, rectangular or oval, for example. The gas flow can also be influenced by the choice of the radius of the front edge in the inlet region 56 of the flow duct 50 and can be designed with sharper edges than with plastic pipes in the case of metal pipes.

In principle, the upper side 75e and the lower side 75f, i.e. the opposing sides, of one wing 75 can have different radii of curvature.

The corresponding shape of the webs 76 can also be provided, which can be formed in a streamlined, symmetrical or asymmetrical manner and can have an angle of attack α with respect to the main flow direction 18. In this case, the selection of the respective angle of attack can be used to generate a helix in the air mass flow or to influence a helix. In particular, variations in thickness along the main flow direction 18 can be taken into account. The number of tabs 76 can likewise be freely selected.

The shear layer generated downstream of the tabs 76 correspondingly produces a more or less intensive mixing, but may also produce a more or less pressure drop. In this case, the pressure drop contains a pressure component and a friction-based component, which can be taken into account in an optimized sense in the design of the winged-grid.

Fig. 10 shows a cross-sectional view of a wing grate 74 according to another embodiment. Only the differences from the previous embodiments and the same components have been described with the same reference numerals.

The wings 75 may have a non-uniform thickness and curvature or curvature as viewed in the main flow direction 18. The thickness distribution, i.e. the relation of the thickness to the respective position along the length of the wing 75, may correspond to a wing profile in combination with the curvature distribution or curvature distribution on the upper side 75e and the lower side 75 f. The wing 75 forms a channel 81 between itself and the web 76. The channels 81 may converge or diverge in the main flow direction 18, but may in particular constitute a converging-diverging. The distance of the wings 75 perpendicular to the main flow direction 18 in this case decreases or increases, in particular first decreases and then increases, with increasing position of the wings as seen in the main flow direction 18. The radially innermost channel 81b is formed, for example, convergent. The remaining channels 81, with the exception of the radially innermost channel 81b, are for example formed convergent-divergent. As a possible extreme, in particular in the case of a connecting part 77 which is flat or is formed parallel to the main flow direction 18, or in the case of a wall 60 of the draft tube 50 which is formed in one piece, the outer channel 81a between the outer wing 75 and the connecting part 77 is formed so as to diverge.

Fig. 11 shows a perspective view of a wing grate 74 according to another embodiment. Only the differences from the previous embodiments and the same components have been described below with the same reference numerals. The length of the wings may vary in the main flow direction. For example, each wing may have a different length in the main flow direction. The wings 75 can also be offset from one another in the main flow direction 18 for the same length. In this case, the webs 76 can have the length of the wings 76 in the main flow direction 18 or a smaller or larger length than these.

In the wing grate 74 of fig. 11, the wings 75 and the webs 76 thus have different lengths in the main flow direction 18. For example, the outer wing 77 has a shorter length than the wing 75 adjacent thereto in the radial direction. The wings 75 of the winged grating 74 of fig. 11 are arranged, for example, in 5 concentric rings, wherein the first ring of outer wings 77, the third ring of outer wings and the fifth ring of inner wings 78 have a smaller length than the second and fourth rings, seen from the outside inwards. As can be seen in fig. 11, the tab 76 has a jump-type change in its length. The jump in length of the tab 76 in the radial direction is located, for example, at a midpoint between an inner and an outer wing 75. In this case, a web 76 has the length of the inner wing 75 up to the jump point 91 and the length of the outer wing 75 from the jump point 91, for example. Here the relative radial position between the wings 75 may vary. A continuous change in the length of the tab can likewise occur.

fig. 12 shows another embodiment of the winged-grid 74. Only the differences from the previous embodiments and the same components have been described below with the same reference numerals. As can be seen from fig. 12, the required mold separation for the injection molding process is preferably realized in the region of the webs 76. In this case, the step 92 and the transition point 94 can occur both in the main flow direction 18 and in the radial and circumferential directions.

fig. 13 shows a perspective view of a wing grate 74 according to another embodiment. Only the differences from the previous embodiments and the same components have been described below with the same reference numerals. The vane 75 may have at least partially recesses 96 in the front and rear end regions, as seen in the main flow direction 18. For example, the wings 75 have modulated sinusoidal wave shaped recesses 96 extending in the circumferential direction or in the radial direction. These recesses 96 can alternatively be formed as right-angled or rounded. The number and amplitude of these modulated notches can here be varied, in particular from one wing 75 to the other 75, in order to reduce or avoid a common vibration mode when the winged grating 74 follows.

Fig. 14 shows a cross-sectional view of one wing 75 of a winged fence 74 according to another embodiment. The cross section extends here in the main flow direction 18. Only the differences from the previous embodiments and the same components have been described below with the same reference numerals. In the region upstream with respect to the main flow direction 18, i.e. in the region of the front edge of the wing 75 and in particular on the strongly curved suction side of the wing 75 and/or the web 76, an additional, locally very limited shaping can be achieved in the form of a thickened portion, as will be explained in more detail below with reference to fig. 15A to 15E.

fig. 15A to 15E show a top view of the wing of fig. 14 viewed in the line of sight of arrow D according to a possible variant of the wing 7. The molding 98 may be formed in the form of a thin rod, as shown in FIG. 15A. The molding 98 may be formed in the form of a serrated bar, as shown in FIG. 15B. The molding 98 may be formed in the form of an oscillating rod, as shown in FIG. 15C. It is thus possible for the shaping 98 to have different cross sections and extensions perpendicular to the main flow direction 18. Alternatively, discontinuous schemes can also be implemented. For example, the contouring 98 may be formed in the form of a rod-shaped segment 102, as shown in FIG. 15D. Alternatively, the shaping 98 can also form triangular segments 102, as shown in fig. 15E. All of the above-described contouring 98 will cause abrupt excitation of laminar flow and cause reduced flow disengagement and reduced pressure loss. In general, the wings 75 can have an additional, locally limited contouring 98 in the form of thickened portions of different cross-section and of different extent perpendicular to the main flow direction 18, including a discontinuous configuration.

Claims

1. Sensor device (100) for determining at least one flow property of a fluid medium flowing in a main flow direction (18), wherein the sensor device (100) has a plug-in sensor (12) arranged in a flow guide tube (50) and having a sensor (32) for determining the flow property of the fluid medium and at least one inlet (16) facing the main flow direction (18), characterized in that: the sensor device (100) has at least one winged grating (74) arranged upstream of the plug-in sensor (12) in the main flow direction (18), wherein the winged grating (74) has a plurality of wings (75) and webs (76) for deflecting the fluid medium in the main flow direction (18) at the plug-in sensor (12), wherein the wings (75) are at least partially provided in a circular shape or have a variable radius, wherein the wings (75) are arranged in such a way, so that they have an angle of attack (alpha) of 0 DEG to 90 DEG for reducing the air flow fluctuations and for generating a uniform high flow velocity at the plug-in sensor (12), wherein the wings (75) are arranged in such a way and are designed in such a way in their thickness distribution and camber distribution, so that an at least partially convergent or convergent-divergent channel (81) is formed between the wing itself and the adjacent web.

2. The sensor device (100) according to claim 1, wherein the airfoil (75) is a supporting profile, wherein the angle of attack (α) of the airfoil (75) of the supporting profile decreases from the outside to the inside for the airfoil grating (74).

3. Sensor device (100) according to claim 1 or 2, wherein the wing (75) is at least partially curved, as seen in the main flow direction (18).

4. The sensor device (100) according to claim 1 or 2, wherein the wings (75) and the tabs (76) have a non-uniform thickness seen in the main flow direction (18).

5. Sensor device (100) according to claim 1 or 2, wherein the length of the wing (75) in the main flow direction (18) varies from the outside in the direction of the centre point (80).

6. the sensor device (100) according to claim 1 or 2, wherein the tab (76) has the same length or a different length in the main flow direction as the wing (75).

7. Sensor device (100) according to claim 1 or 2, wherein the flap (75) and/or the tab (76) at least partially has a notch (90) in a front end region (82) and/or a rear end region (83) as seen in the main flow direction (18).

8. Sensor device (100) according to claim 1 or 2, wherein the flap (75) and/or the tab (76) has a shaping (98) in a front end region (82) viewed in the main flow direction (18).

9. Sensor device (100) according to claim 8, wherein the shaping (98) is formed in the form of a thickened portion perpendicular to the main flow direction (18).

10. The sensor device (100) according to claim 1, wherein the fluid medium is intake air of an internal combustion engine.

11. sensor device (100) according to claim 1, wherein the wings (75) are at least sectionally arranged in an oval shape.

12. The sensor device (100) according to claim 1, wherein the angle of attack (α) is 0 ° to 20 °.

13. The sensor device (100) according to claim 1, wherein the angle of attack (α) is an angle of attack (α) of 0 ° to 10 °.

14. the sensor device (100) according to claim 7, the indentations being in the shape of squares or modulated sine waves.

15. Sensor device (100) according to claim 8, wherein the wing (75) and/or the web (76) has a shaping (98) on a more strongly curved upper side (75e) of the wing (75) and/or the web (76).