KR102552763B1 - Sensor device for detecting at least one flow property of a flowing fluid medium - Google Patents

Abstract

The present invention relates to a sensor device (10) for detecting at least one flow characteristic of a fluid medium. The sensor device 10 includes at least one sensor housing 14, and at least one electronic device having at least one flow sensor 40 for detecting the flow characteristics in the sensor housing 14. module 30 is accommodated, the electronics module 30 is at least partially housed within the electronics chamber 20, and at least one moisture sensor 42 is housed inside the sensor housing 14; , the sensor housing 14 includes at least one inlet 46 for providing moisture in the fluid medium to the moisture sensor 42 . the sensor housing (14) includes at least one outlet (48) for discharging the fluid medium from the electronics chamber (20), and a gel (58) is provided in the electronics chamber (20); the gel (58) at least partially covers the electronics module (30) and the sensor housing (14) comprises at least one protrusion (60) projecting in a direction towards the electronics chamber (20); , the protrusion 60 protrudes into the gel 58, the protrusion 60 defining at least one channel 62, the channel 62 having the inlet 46 and the outlet 48 connect

Description

Sensor device for detecting at least one flow property of a flowing fluid medium

The present invention relates to a sensor device for detecting at least one flow characteristic of a flowing fluid medium.

The prior art discloses many methods and devices for measuring the flow properties of fluid media, ie liquids and/or gases. A flow property can be essentially any physically and/or chemically measurable property that qualifies or quantifies the flow of a fluid medium. It may in particular be a flow rate and/or a mass flow rate and/or a volume flow rate.

The present invention is hereinafter described in relation to a so-called hot-film air mass meter described eg in Konrad Reif (published), Sensoren im Kraftfahrzeug, Vol. 1 2010, pages 146-148. These hot-film air mass meters are generally based on sensor chips, in particular silicon sensor chips, with a measuring surface through which a flowing fluid medium can flow. The sensor chip generally includes at least one heating element and at least two temperature sensors, which are arranged, for example, on a measuring surface of the sensor chip. From the asymmetry of the temperature profile detected by the temperature sensor and influenced by the flow of the fluid medium, the mass flow rate and/or volume flow rate of the fluid medium can be inferred. Hot-film air mass meters are usually designed as implantable sensors, which can be fixedly or exchangeably inserted into the flow pipe.

For example, the flow pipe may be a suction pipe of an internal combustion engine.

In order to be able to infer the specific flow characteristics of the fluid medium accurately from the sensor signals of the hot film air mass meter, in many cases it is desirable that additional information about the fluid medium be provided. DE 10 2010 043 083 A1, for example, discloses a sensor device for detecting the flow characteristics of a fluid medium, said sensor device comprising an air mass meter with a sensor element for detecting an air mass flow rate. A moisture sensor is also provided.

Despite the advantages achieved by the sensor device, the sensor device still leaves room for improvement. The moisture sensor on a separate printed circuit board is protected from media and mechanical influences by a plastic frame with an integrated film acting as a pressure compensating element. To ensure access to the measuring medium to the moisture sensor, an electronics chamber cover placed thereon includes an inlet. The moisture sensor includes a moisture frame and a membrane semi-permeable to moisture flush with the electronics chamber cover. The fluid medium enters and exits the electronics chamber through a gap between the electronics chamber cover and the moisture sensor or through an exhaust hole in the electronics chamber cover. Water ingress in particular can damage electronic components within the electronics chamber, for example by freezing.

The object of the present invention is to detect at least one flow characteristic of a flowing fluid medium, which avoids at least substantially the above-mentioned disadvantages of the known sensor device and is designed in particular to provide an improved evacuation of the fluid medium and thus ventilation of the moisture sensor. To provide a sensor device for

The problem is solved by a sensor device comprising the features of claim 1 .

Regarding at least one flow property that can be qualitatively and/or quantitatively determined, reference may be made to the above description of the prior art, for example. In particular, the flow characteristic may be the flow rate and/or mass flow rate and/or volume flow rate of the fluid medium. The fluid medium may in particular be a gas, preferably air. The sensor device can be used in particular in automotive technology, for example in the intake manifold of an internal combustion engine. Of course, other fields of use are basically possible.

A sensor device according to the invention for detecting at least one flow characteristic of a fluid medium comprises at least one sensor housing. Sensor housing means within the scope of the present invention a one-piece or multi-piece device that at least substantially closes the sensor device to the outside and at least substantially protects it against mechanical influences and preferably against other kinds of influences, such as chemical influences and/or moisture influences. do. In particular, the sensor housing can contain at least one implantable sensor or can be designed as an implantable sensor, which implantable sensor can be inserted into the flowing fluid medium, and can also be inserted interchangeably or permanently. The implantable sensor can for example protrude into the flow tube of the flowing fluid medium, and the flow tube itself can be a component part of the sensor device or can be provided as a separate part with an opening through which the implantable sensor can be inserted. The implantable sensor and sensor housing can in particular be manufactured at least partly from a plastic material, for example by means of an injection molding method.

At least one electronics module with at least one flow sensor for detecting a flow characteristic is housed in the sensor housing. The expression housed in the sensor housing means that the electronics module is at least partially, preferably completely enclosed by the sensor housing. The electronics module is disposed at least partially within the at least one electronics chamber of the sensor housing. An electronics chamber means within the scope of the present invention a chamber that is partially or completely closed inside the sensor housing, said chamber being closed by the sensor housing in at least one direction. Preferably the electronics chamber includes at least one recess within the sensor housing, eg a block-shaped recess, accessible from a surface of the sensor housing. The electronics chamber is accessible, eg from a surface, eg for mounting, and can be permanently or reversibly closed by at least one closure member, eg at least one electronics chamber cover, as described in more detail below.

A flow sensor basically means any sensor element configured to detect at least one flow characteristic. In particular, the flow sensor can be, for example, at least one hot film air mass meter chip in the manner described above. In particular, the hot-film air mass meter chip may comprise at least one silicon chip with a measuring surface through which a flowing fluid medium can flow. On the sensor surface, for example, at least one heating element and at least two temperature sensors can be arranged. As mentioned above, at least one flow property can be inferred from the asymmetry of the temperature profile measured by the temperature sensor. The at least one flow sensor can be arranged for example on a sensor carrier of the electronics module, which sensor carrier protrudes into the flowing fluid medium. The electronic device module can in particular be integrally formed and in particular can support a control and/or evaluation circuit. The control and/or support circuitry is designed to control the flow sensor and/or to receive signals from the flow sensor. Accordingly, the electronic device module can include, for example, at least one circuit carrier. Furthermore, the electronic device module can in particular comprise at least one sensor carrier, which sensor carrier is preferably mechanically connected to the circuit carrier. For example, the circuit carrier can be disposed within the electronics chamber of the sensor housing, and the sensor carrier can protrude from the electronics chamber into the fluid medium. It is particularly preferred that the sensor housing comprises at least one flow channel through which a fluid medium can flow through, in which case the sensor carrier of the electronics module carrying the flow sensor is moved by a fluid medium from the electronics chamber into the sensor housing. It protrudes into at least one perfusable flow channel. The at least one flow channel may in particular be formed in one piece, but may also include at least one main channel and at least one bypass channel branching off from the main channel, in which case the sensor carrier preferably precedes Projects into the bypass channel as is known in the art.

The circuit carrier of the electronic device module can in particular comprise a printed circuit board, said printed circuit board being used in situ or stamped, for example on a mechanical carrier, which can be made of metal material, for example. -bended) mounted on the bottom plate in the form of a part. The sensor carrier can be connected directly to the circuit carrier or to the base plate by means of a part of the carrier, for example by ejecting the sensor carrier onto the base plate. Other embodiments are essentially possible. For example, it is possible to manufacture the electronic device module from a printed circuit board material, in which case the circuit carrier and the sensor carrier are made from the printed circuit board material, preferably from a part of the printed circuit board material. Alternatively or additionally, injection-molded printed circuit boards known from the prior art, for example one or several injection-molded printed circuit boards of the so-called MID-technology (MID = molded interconnect device) are used as electronic device modules. It is also possible. Accordingly, various embodiments are possible.

The sensor device also includes at least one moisture sensor. A moisture sensor is housed inside the sensor housing. The expression arrangement inside the sensor housing means an arrangement in which the moisture sensor is at least partially, preferably completely enclosed by the sensor housing. A moisture sensor basically means any sensor element designed to detect moisture in a fluid medium. For example, resistive and/or capacitive sensor elements as known from the prior art are considered in this case. Examples of such moisture sensors are disclosed in Konrad Reif (published), Volume 1 2010, pages 98-101. However, alternatively or in addition, other types of moisture sensors may also be used within the scope of the present invention.

The sensor housing includes at least one inlet for providing moisture in the fluid medium to the moisture sensor. The sensor housing also includes at least one outlet for discharging the fluid medium from the electronics chamber. A gel is provided within the electronics chamber. The gel at least partially covers the electronic device module. Preferably, the gel is cured so that it no longer has fluidity. The sensor housing also includes at least a protrusion projecting in a direction towards the electronics chamber. The protrusions protrude into the gel. In this case the protrusion defines a channel. A channel connects the inlet and outlet. Accordingly, the fluid medium entering the electronic device chamber is directed through the channel to the outlet.

As noted above, the sensor housing preferably includes at least one electronics chamber cover. An electronics chamber cover is formed to close the electronics chamber. The electronics chamber cover includes a protrusion. Due to this, the channel can be formed by the electronics chamber cover upon closing of the electronics chamber. In this case, the channel is laterally defined by the electronics chamber cover, protrusion and gel.

The inlets and/or outlets are preferably formed in the electronics chamber cover. Alternatively or additionally, the inlet and/or outlet may be formed in the sensor housing itself. The protrusions may define inlets and outlets.

The electronic device module may include a moisture sensor. The electronic device module can, for example, comprise a circuit carrier, in which case the moisture sensor is arranged on the circuit carrier. As described above, the electronic device module may include a sensor carrier. The sensor carrier can support the flow sensor and protrude from the electronics chamber into at least one flow channel permeable by a fluid medium within the sensor housing, in which case the flow sensor and the moisture sensor are on the same side of the electronics module. placed on top For example, the electronic device module comprises a control and/or evaluation circuit, said control and/or evaluation circuit being arranged on a circuit carrier, said control and/or evaluation circuit and said moisture sensor together on one side of the circuit carrier. placed on top

A channel may be formed to ventilate the moisture sensor. Ventilation means the achievement of the formation of a flow of a fluid medium inside a channel from the inlet to the outlet. This can in particular be achieved by the sensor housing being formed such that, when the fluid medium flows around the sensor housing, there is a higher static pressure in the region of the inlet than in the region of the outlet. Static pressure in the region of the inlet and outlet means the static pressure acting on the respective cross-sections of the inlet and outlet from the outside by the fluid medium. That is, it means the static pressure acting from the periphery of the sensor housing towards the inside of the sensor housing or channel.

Static pressure in the scope of the present invention means the ratio of the force applied to each surface connected to the fluid, and the force acts in proportion to the size of the surface. The static pressure can be found, for example, by the equation Pstat.= p x g x h, where p is the density of the fluid, g is the gravitational acceleration and h is the height of the fluid column above the surface.

Within the scope of the present invention, the pressure difference between the inlet and outlet is realized by structural measures of the sensor housing. For example, the pressure difference can be realized by appropriate design of the cross section, location and shape of the inlet and outlet. Other structural measures, such as vortex generators or the shape of the electronics chamber cover, can also cause fluid flow within the channel from the inlet to the outlet.

The moisture sensor may include at least one measuring chamber, the measuring chamber being bounded by at least one membrane and frame at least partially permeable to moisture.

The inlet can have essentially any cross-section, for example a rectangular and/or circular and/or polygonal cross-section. Other embodiments are also possible.

The protrusions may form channels. For example, the electronic device chamber cover is formed as a double wall, so that the protrusion forms a channel. This embodiment can be applied to cases where it is premised that the gel does not form a flat surface upon curing. By means of the channel-shaped protrusions, a defined cross-section ratio for the channel can be realized.

The sensor device may also include one or more other sensor elements for detecting at least one other physical and/or chemical property of the fluid medium. In particular, the sensor device may also comprise at least one temperature sensor, in particular at least one temperature sensor arranged on the outer surface of the sensor housing. For example, a temperature sensor may be disposed on the outer surface of the sensor housing such that it is disposed on the surface facing the moisture sensor. Of course, other embodiments are basically possible. In particular the temperature sensor can be arranged in at least one recess on the side wall of the sensor housing. The temperature sensor may in particular include at least one temperature dependent resistor. Alternatively or additionally, other types of temperature sensors may also be used. A fluid medium can flow freely around the temperature sensor. That is, the temperature sensor may not be enclosed by the sensor housing of the sensor element. The temperature sensor can in particular be connected to the sensor housing by means of a press-fit and/or form-fit, for example by having the supply lines of the temperature sensor crimped or otherwise connected to the outer wall of the sensor housing. The supply lines of the temperature sensor can in particular be led into the interior of the sensor housing and can be connected there, for example, to an electronics module and/or to a plug connector of the sensor device. Various other embodiments are essentially possible.

The sensor device may also include, for example, a pressure sensor. A pressure sensor basically means any sensor element designed to detect the pressure of a fluid medium. In particular, it may be a pressure sensor as described, for example, in Konrad Reif (published), Sensoren im Kraftfahrzeug, Volume 1 2010, pages 80-82 and 134-136. Alternatively or additionally, other types of pressure sensors may be used, for example pressure sensors based directly on the use of one or several strain gauges or similar pressure sensor elements.

Other optional details and features of the invention are presented in the following description of a preferred embodiment shown schematically in the drawings.

1 is an exploded view of a sensor device according to the invention for detecting at least one flow characteristic of a fluid medium;
2 is a cross-sectional view of the sensor device;
3 is a plan view of the sensor device;

1 shows an exploded view of a sensor device 10 according to the invention for detecting at least one flow characteristic of a fluid medium. The sensor device 10 is formed in this embodiment as a hot-film air mass meter and includes an implantable sensor 12 . The implantable sensor 12 can be inserted into a flow of a fluid medium, eg intake air, reversibly inserted eg into an intake tube or permanently installed. Implantable sensor 12 includes a sensor housing 14 . A channel region 16 and an electronics region 18 are housed within the sensor housing 14 and the electronics region includes an electronics chamber 20 inserted into the sensor housing 14 . Channel region 16 may be closed by bypass channel cover 22 . In the bypass channel cover 22, a flow channel 24 through which a fluid medium can flow is formed. The flow channel 24 includes a main channel 26 and a bypass channel 28 branching off from the main channel.

The electronic device module 30 is accommodated in the electronic device chamber 20 . The electronic device module 30 comprises a circuit carrier 32 with control and/or evaluation circuits 34 , which circuit carrier 32 can be accommodated on a base plate 36 , for example. The electronic device module 30 also includes a wing-shaped sensor carrier 38 extruded on the bottom plate 36 . The sensor carrier 38 protrudes into the bypass channel 28 . Into the sensor carrier 38, a flow sensor 40 in the form of a hot-film air mass meter chip is inserted.

The sensor device 10 also includes a moisture sensor 42 . Moisture sensor 42 is accommodated inside sensor housing 14 . Accordingly, the moisture sensor 42 is disposed on the circuit carrier 32 of the electronics module 30 . The sensor carrier 38, the base plate 36 and the circuit carrier 32 form an electronics module 30, which may additionally include a control and/or evaluation circuit 34. can In addition to the sensor carrier 38 , the circuit carrier 320 and the electronics of the control and/or evaluation circuit 34 are glued onto the base plate 36 . The flow sensor 40, the moisture sensor 42 and the control and/or evaluation circuit 34 are typically connected to each other by bonding bonds. The electronic device module 30 thus formed is bonded within the electronic device chamber 20 , for example.

The sensor device 10 also includes an electronics chamber cover 44 . The electronic device chamber cover 44 is formed to close the electronic device chamber 20 . The closure can be permanent or reversible. The sensor device 10 also includes at least one inlet 46 for providing moisture in the fluid medium to the moisture sensor 42 . An inlet 46 is formed in the electronics chamber cover 44 . Sensor device 10 also includes at least one outlet 48 for discharging fluid medium from electronics chamber 20 . An outlet 48 is also formed in the electronics chamber cover 44 . The inlet 46 and the outlet 48 are spaced apart from each other. For example, the inlet 46 and outlet 48 are disposed on opposite longitudinal sides of the electronics chamber cover 44 .

2 shows a cross-sectional view of the sensor device 10 . As shown in FIG. 2 , moisture sensor 42 includes at least one measurement chamber 50 . The measurement chamber 50 is bounded by a frame 54 and at least one membrane 52 that is at least partially permeable to moisture. Moisture sensor 42 may be formed as moisture module 56 or may be included within moisture module 56 . A gel 58 is provided within the electronics chamber 20 . The gel 58 at least partially covers the electronic device module 30 and in particular the circuit carrier 32 . The gel 58 is cured, for example by heat treatment or by means of UV-light, so that it no longer has fluidity. The sensor device 10 includes a protrusion 60 protruding in a direction toward the electronic device chamber 20 . In particular, the electronics chamber cover 44 includes the protrusion 60 . The protrusion 60 is designed as a sealing strut, for example. In this case, the protrusion 60 protrudes into the gel 58 . In other words, protrusion 60 is inserted into gel 58 .

Gel 58 protects the electronics of sensor device 10 . An electronics chamber cover 44 is provided for mechanical protection.

3 shows a plan view of the sensor device 10 . The electronics chamber cover 44 is shown transparent for illustration purposes, and only the protrusion 60 is outlined. Protrusion 60 defines a channel 62 . Channel 62 connects inlet 46 and outlet 48 . Thus, the fluid medium introduced into the electronics chamber 20 can leave the electronics chamber 20 again inside the channel 62 in the region of the outlet 48 . Due to this, the moisture sensor 42 can be ventilated. As shown in FIG. 3 , protrusion 60 defines an inlet 46 and an outlet 48 .

As shown in FIG. 1 , the flow sensor 40 and moisture sensor 42 are disposed on the same side 64 of the electronics module 30 . In other words, the flow sensor 40 and moisture sensor 42 are together disposed on one and the same side 64 of the electronics module 30 . In particular, the moisture sensor 42 and the control and/or evaluation circuit 34 are together arranged on one side 66 of the circuit carrier 32 .

Sensor device 10 may be configured to detect other flow characteristics of a fluid medium. As shown in FIG. 1 , sensor arrangement 10 also includes at least one temperature sensor 68 configured to detect the temperature of the fluid medium. A temperature sensor 68 may be disposed on an exterior surface of the sensor housing 14 . For example, the temperature sensor 68 may be disposed on an outer surface of the sensor housing 14 opposite the moisture sensor 42 . In particular, the temperature sensor 68 may be disposed in at least one recess on the sidewall or rear surface of the sensor housing 14 . As shown in FIG. 1 , the sensor device may also include a housing seal 70 configured to seal the sensor housing 14 against the flow tube.

10 sensor device
14 sensor housing
20 electronics chamber
30 electronics module
32 circuit carrier
34 control and/or evaluation circuit
38 sensor carrier
40 flow sensor
42 moisture sensor
44 electronics chamber cover
46 inlet
48 outlet
50 measuring chambers
Act 52
54 frames
58 gel
60 protrusion
62 channels

Claims (10)

A sensor device (10) for detecting at least one flow property of a fluid medium, comprising at least one sensor housing (14), in which at least one flow property for detecting said flow property At least one electronic device module 30 having a sensor 40 is accommodated, the electronic device module 30 is at least partially accommodated in the electronics chamber 20, and also inside the sensor housing 14 at least one moisture sensor (42) is housed therein, the sensor housing (14) comprising at least one inlet (46) for providing moisture in the fluid medium to the moisture sensor (42); In 10),
the sensor housing (14) includes at least one outlet (48) for discharging the fluid medium from the electronics chamber (20), and a gel (58) is provided in the electronics chamber (20); the gel (58) at least partially covers the electronics module (30) and the sensor housing (14) comprises at least one protrusion (60) projecting in a direction towards the electronics chamber (20); , the protrusion 60 protrudes into the gel 58, the protrusion 60 defining at least one channel 62, the channel 62 having the inlet 46 and the outlet 48 connect,
The sensor housing 14 includes an electronic device chamber cover 44, the electronic device chamber cover 44 is formed to close the electronic device chamber 20, and the electronic device chamber cover 44 is Including the protrusion 60,
the inlet (46) and the at least one outlet (48) are formed in the electronic device chamber cover (44);
The sensor device (10), characterized in that the projection (60) defines the inlet (46) and the outlet (48). delete delete delete 2. Sensor device (10) according to claim 1, characterized in that the electronic device module (30) comprises the moisture sensor (42). Sensor device (10) according to claim 1, characterized in that the electronic device module (30) comprises a circuit carrier (32) and the moisture sensor (42) is disposed on the circuit carrier (32). 2. The method of claim 1, wherein the electronics module (30) comprises a sensor carrier (38), the sensor carrier (38) supports the flow sensor (40) and removes the sensor housing from the electronics chamber (20). (14) into at least one flow channel permeable by the fluid medium, wherein the flow sensor (40) and the moisture sensor (42) are on the same side (64) of the electronic device module (30). A sensor device (10) characterized in that it is arranged. 8. The electronic device module (30) of claim 7, comprising circuitry (34) for performing one or more of control and evaluation, wherein the circuitry (34) for performing one or more of control and evaluation is a circuit carrier (32). ), wherein the circuit 34 for performing at least one of the control and evaluation and the moisture sensor 42 are disposed together on one side 66 of the circuit carrier 32. Sensor device (10). 2. Sensor device (10) according to claim 1, characterized in that the channel (62) is formed to ventilate the moisture sensor (42). 2. The method according to claim 1, wherein the moisture sensor (42) comprises at least one measuring chamber (50) comprising at least one membrane (52) at least partially permeable to moisture and a frame ( 54).

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