Sensor element for recording at least one property of a fluid medium

Abstract

A sensor element for recording at least one property of a fluid medium. The sensor element includes at least one housing that forms at least one wall of at least one flow channel that can be traversed by the flow of the fluid medium. In the wall, at least one pressure tap branches off from the flow channel. At least one pressure sensor for recording a pressure of the fluid medium is configured in the pressure tap. Provided in the wall is at least one outflow contour that at least partially surrounds an orifice of the pressure tap and is adapted for diverting impurities flowing along the wall away from the orifice of the pressure tap.

Claims

1. A sensor element for recording at least one property of a fluid medium, comprising: at least one housing, the housing forming at least one wall of at least one flow channel that can be traversed by the flow of the fluid medium, wherein in the wall, at least one pressure tap branches off from the flow channel; and at least one pressure sensor for recording a pressure of the fluid medium being configured in the pressure tap; wherein, in the wall is at least one outflow contour that at least partially surrounds an orifice of the pressure tap and that is adapted for diverting impurities flowing along the wall away from the orifice of the pressure tap.

2. The sensor element as recited in claim 1, wherein the outflow contour annularly surrounds the orifice of the pressure tap.

3. The sensor element as recited in claim 1, wherein the outflow contour includes an annular groove.

4. The sensor element as recited in claim 3, wherein the annular groove has a circular-cylindrical design.

5. The sensor element as recited in claim 1, wherein the outflow contour has a depth of at least 2 mm.

6. The sensor element as recited in claim 1, wherein a partition wall is provided between the outflow contour and the pressure tap.

7. The sensor element as recited in claim 6, wherein the partition wall is recessed from the wall.

8. The sensor element as recited in claim 1, wherein the pressure tap has a bore that branches off from the flow channel.

9. The sensor element as recited in claim 1, wherein the bore is one of completely or partially configured as a cylindrical bore.

10. The sensor element as recited in claim 1, wherein the pressure tap is a blind bore that branches off from the flow channel, the pressure sensor being configured at one end of the blind bore.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further details and optional features of the present invention are described in the exemplary embodiments that are schematically shown in the figures.

(2) FIGS. 1A and 1B show an exemplary embodiment of a sensor element according to the present invention.

(3) FIGS. 2A and 2B show various representations of a sensor element according to the present invention in the form of a plug-in sensor.

(4) FIG. 3 shows an air system of an internal combustion engine having a configuration of the sensor element according to the present invention between a charge-air cooler and a throttle valve.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(5) FIGS. 1A and 1B show an exemplary embodiment of a sensor element 110 according to the present invention. In this instance, FIG. 1A shows a plan view of a wall 112 of a housing 114 of sensor element 110, and FIG. 1B shows a sectional view through housing 114 along a line of intersection A-A in FIG. 1.

(6) In this exemplary embodiment, the sensor element is in the form of a plug-in sensor 116 that may be designed, for example, as a pressure-based mass airflow meter (PFM). Sensor element 110 extends into a flow of a fluid medium and may be circumflowed by the fluid medium, for example, in one or more possible flow direction(s) 118 shown in FIG. 1B. Accordingly, wall 112 may, for example, be at least one side wall, at least one front wall, at least one rear wall, or also at least one front end face of plug-in sensor 116.

(7) Sensor element 110 has at least one pressure tap 120. If a plurality of pressure taps 120 are provided, then a differential pressure may be generated, for example, as is clarified in greater detail in the following with reference to FIGS. 2A and 2B. Pressure tap 120 includes at least one bore 122, for example, at least one cylindrical bore 122, for example, which is sunk into wall 112 at an orifice 124. Bore 122 is designed, in fact, as a blind bore. Configured at the end of bore 122 in pressure tap 120 is a pressure sensor 125 for recording a pressure of the fluid medium. Pressure tap 120 may be used, namely, for recording a static pressure of the fluid medium.

(8) Furthermore, at least one outflow contour 126 is provided in wall 112. This outflow contour 126 surrounds orifice 124 of pressure tap 120 at least partially; and more specifically, as shown in FIGS. 1A and 1B, completely. Outflow contour 126 is adapted for diverting impurities flowing along wall 112 away from orifice 124 of pressure tap 120.

(9) In the illustrated exemplary embodiment, outflow contour 126 annularly surrounds orifice 124 of pressure tap 120. As is discernible in FIG. 1B, outflow contour 126 may include an annular groove 128 that has a circular-cylindrical or a cylindrical ring design and features a rectangular profile, for example. In principle, however, other profiles are also possible.

(10) Outflow contour 126 has a depth T.sub.K. Provided, moreover, between outflow contour 126 and bore 122 of pressure tap 120 is a partition wall 130 that may also be referred to as a shoulder. This partition wall 130 may, in fact, be recessed from wall 112, especially set back by a depth TA from wall 112. Pressure tap 120 itself may have a diameter D.sub.A. An inner diameter of annular groove 128 is denoted in FIG. 1B by D.sub.A,I. An outer diameter of outflow contour 126 is denoted in FIG. 1A by D.sub.A,A.

(11) The purpose of outflow contour 126 is to protect pressure sensor 125 from an ingress of water accumulations and dirt deposits. If a plurality of pressure taps 120 are provided in sensor element 110, then at least one of pressure taps 120, a plurality of pressure taps 120, or even all of pressure taps 120 may be provided with an outflow contour of this kind. Specifically, static pressure taps may have such an outflow contour 126. Water and dirt particles, that advance over wall 112 toward pressure tap 120, are deflected by outflow contour 126 and flow past static pressure tap 120 in outflow contour 126. Thus, the static pressure taps are protected from water and dirt particles.

(12) A plurality of measures make it possible to augment the deposition of water and dirt particles in the configuration in accordance with FIGS. 1A and 1B, as well as in other embodiments. Thus, on the one hand, shoulder depth T.sub.A may be increased, preferably under the condition that outflow contour depth T.sub.K is at least two to three times greater than shoulder depth T.sub.A. Water droplets that flow away over outflow contour 126 generally do not come in contact with the surface defined by diameters D.sub.D and D.sub.A,I. Furthermore, alternatively or additionally to the measures mentioned, outflow contour depth T.sub.K may be increased. Furthermore, the cross section of the outflow contour may be increased. On the other hand, the surface area defined by diameters D.sub.D and D.sub.A,I may also be minimized, alternatively or additionally to one or more of the measures already mentioned. For example, shoulder depth T.sub.A may be 2-10 mm; outflow contour depth T.sub.K may, in fact, have a value of T.sub.K=T.sub.A+3 to 6 mm. Diameter D.sub.D may, for example, be 4-6 mm. Diameter D.sub.A,I may, for example, have a value of D.sub.A,I=D.sub.D+2 to 5 mm. Diameter D.sub.A,A may have a value of D.sub.A,A=D.sub.AI+4 to 10 mm, for example.

(13) With reference to FIGS. 2A and 2B, the following explains how housing 114 and pressure tap 120 may be designed. Thus, the figures show various representations of a sensor element 110 according to the present invention, which, in turn, may be in the form of a plug-in sensor 116. Plug-in sensor 116 may extend into a flow channel 132, for example, so that at least one wall 112 of flow channel 132 is formed at least partially by housing 114. In this context, FIG. 2A shows an embodiment of plug-in sensor 110 with a closed cover, whereas a cover is removed in the embodiment in accordance with FIG. 2B, so that a channel section 134, which is configured in housing 114 and into which fluid medium may enter through an opening 128, is visible. Apart from outflow contour 126, reference may be made to the German Patent Application No. DE 10 2007 053 273 A1 described above for possible embodiments of sensor element 110. Other embodiments are also possible, however.

(14) As is discernible in these FIGS. 2A and 2B, sensor element 110 may have a plurality of pressure taps 120 that may be configured within channel section 134 and/or on an outer side and/or front end and/or rear side and/or front side of plug-in sensor 116. Thus, every region of housing 114 that is attainable by the fluid medium and over which the fluid medium is able to flow, may function as wall 112 that features at least one pressure tap 120. For example, in the illustrated example, two pressure taps 120 may be configured on an outer side of housing 114, thus on an outer side of plug-in sensor 116, and a pressure tap 120 on the inside of channel section 134. Of these pressure taps 120, one, a plurality of, or all pressure taps 120 may be designed to include the described outflow contour 126. Various other configurations are possible.

(15) Sensor element 110, for example, plug-in sensor 116, may be configured, namely, in an air system 136 of an internal combustion engine 137 that is shown exemplarily in FIG. 3. As is discernible there, this air system 136 includes, for example, an induction tract 138 including an air filter 140, a charge-air cooler 142, and a throttle valve 144, as well as an exhaust tract 146 that includes an exhaust-gas flap 148. Furthermore, an exhaust gas recirculation 150 may be optionally provided. Sensor element 110 may be configured between charge-air cooler 142 and throttle valve 144, for example, and may be designed as a pressure-based mass airflow meter.