Sensor device for determining material properties, media tank

Abstract

The invention relates to a sensor device which is configured for determining material properties of a gaseous and / or liquid medium and which can be arranged at least partially in the medium, having at least one ultrasonic transmitter, at least one first reflector, at least one ultrasonic receiver, wherein the path of the ultrasonic signal from the ultrasonic transmitter to the first reflector and from the first reflector to the ultrasonic receiver forms a first measurement path (M1, M1'), having a second reflector which is opposed to the first reflector such that the path of the ultrasonic signal forms a second measurement path, wherein the reflectors are integrally configured as a reflector member with a common carrier element. Wherein the reflector member is a stamped and bent part and has a flat substrate as the carrier element, the reflectors being bent out of the substrate on the same side of the substrate as reflector springs. The invention also relates to a medium tank.

Description

Technical Field

[0001] This invention relates to a sensor device.

[0002] The present invention also relates to a media container for receiving and providing liquid or gaseous media, the media container being equipped with a sensor device for determining the material properties of the media received in the media container. Background Technology

[0003] Sensor devices and media containers of the types mentioned at the beginning are known in the prior art. Ultrasonic sensor devices are used to determine specific properties of a medium in a liquid or gaseous state. For example, the concentration of urea in a solution can be determined based on the sound velocity of an aqueous solution of urea in an exhaust gas aftertreatment system. For this purpose, an ultrasonic transmitter is electrically excited to emit ultrasonic signals or ultrasonic pulses. Different measurement paths for the ultrasonic signals are provided by means of reflectors, through which the ultrasonic signals travel to reach the ultrasonic receiver. The determination of material properties can be performed with particular accuracy by comparing these measurement paths, as a reference value is provided by the second measurement path. Knowing the measurement path measured during the transmission time of the sensed ultrasonic signal, the material properties of the medium can be reliably determined.

[0004] For example, publication DE 10 2018 202 587 A1 discloses a general-purpose sensor device. A similar sensor device is also described in publication DE 10 2014 213 233 A1. Summary of the Invention

[0005] The sensor device of the present invention is configured to determine the material properties of a gaseous and / or liquid medium and can be at least partially arranged in the medium, the sensor medium comprising: at least one ultrasonic transmitter for generating an ultrasonic signal; at least one first reflector arranged spaced apart from the ultrasonic transmitter; at least one ultrasonic receiver for receiving the ultrasonic signal reflected from the first reflector, wherein the path of the ultrasonic signal from the ultrasonic transmitter to the first reflector and from the first reflector to the ultrasonic receiver forms a first measurement path; and a second reflector arranged opposite to the first reflector such that the path of the ultrasonic signal from the ultrasonic transmitter to the first reflector, from the first reflector to the second reflector, from the second reflector to the first reflector and from the first reflector to the ultrasonic receiver forms a second measurement path, wherein these reflectors are integrally constructed as a reflector member with a common carrier element.

[0006] The sensor device of the present invention has the advantages of being cost-effectively manufactured and particularly robust. This is achieved through the sensor device of the present invention: the reflectors are manufactured using cost-effective processes with low material consumption, and due to their advantageous construction, the arrangement of these reflectors relative to each other is durable and robust. According to the invention, this is achieved by the reflector member being a stamped and bent piece having a flat substrate as a carrier element, with the reflector, as a reflector reed, bent out from the substrate on the same side. Since the reflector, as a reflector reed, is located on or bent out from the same side of the substrate, the substrate ultimately extends in the direction of ultrasonic signal propagation, and only the reflector reed is in the path of the ultrasonic signal, so as to reflect the ultrasonic signal selectively, especially to achieve two different measurement paths. By being constructed as a stamped and bent piece, the reflector member can be mass-produced cost-effectively.

[0007] Preferably, the substrate has a device for securing the substrate to a box containing a medium. This ensures reliable arrangement of the sensor device within the box in a simple manner.

[0008] In particular, the substrate has at least one opening or notch serving as the device, into which the protrusion of the housing can be inserted at least substantially without gaps for orienting and securing the reflector component. This creates a form-locking connection between the reflector component and the housing, which permanently ensures the arrangement of the reflector component within the housing.

[0009] Furthermore, preferably, the first reflector has a first reflector surface, which is formed by a first reflector spring in a reflector spring, so as to reflect the ultrasonic signal at least to the ultrasonic receiver. Therefore, the ultrasonic signal is directly reflected back to the ultrasonic receiver through the first reflector surface. This achieves the desired reflector path, or measurement path, in a simple manner.

[0010] The second reflector preferably has a second reflector surface, which is formed by a second reflector spring in the reflector spring. Therefore, the second reflector surface can be positioned independently of the first reflector surface by the corresponding bending process of the stamping and bending member.

[0011] Preferably, the second reflector surface is configured to reflect the ultrasonic signal at least back to the first reflector surface. Therefore, the second reflector surface is located in the second measurement path and reflects the received ultrasonic signal, especially the ultrasonic signal that has been guided from the first reflector to the second reflector, back to the first reflector or the first reflector surface, particularly so that it can return from there to the ultrasonic receiver.

[0012] Preferably, the first reflector has a third reflector surface formed by another reflector reed to reflect the ultrasonic signal from the ultrasonic transmitter to the second reflector surface, wherein the second reflector surface is configured to reflect the ultrasonic signal back to the third reflector surface, which reflects or directs the ultrasonic signal from the second reflector surface to the ultrasonic receiver. Thus, a second measurement path is formed through the third and second reflector surfaces, and the ultrasonic signal is reflected back once between the third and second reflector surfaces.

[0013] Preferably, the ultrasonic transmitter and ultrasonic receiver are constructed as ultrasonic transducers. The ultrasonic transducer can both transmit and receive ultrasonic signals, thus combining the functions of two devices in one component, thereby enabling the sensor device to be implemented in a space-saving and cost-effective manner.

[0014] The medium box of the present invention is characterized by the sensor device structure of the present invention. Here, the advantages already mentioned are obtained.

[0015] Preferably, the substrate is arranged at the bottom of the media box within the media box, and the ultrasonic transmitter and ultrasonic receiver are arranged at the bottom outside the media box. Thus, ultrasonic signals are introduced from the outside into the media box and reflected there by the reflector component as described above. Since the ultrasonic transmitter and ultrasonic receiver are arranged outside the media box, there is no need for extensive cable routing to ensure the hermeticity and functionality of the transmitter and receiver. Instead, the reflector component, particularly made of a material durable for the media within the box, is arranged inside the box, especially at the bottom, and is secured there, for example, by means of the previously mentioned device. Preferably, the bottom has one or more protrusions that interact with one or more openings in the substrate to orient and / or lock the reflector component at the bottom of the media box relative to the ultrasonic receiver and ultrasonic transmitter arranged outside the box. In particular, the media box has recesses on its side walls for receiving the ultrasonic transmitter and ultrasonic receiver, especially for receiving ultrasonic transducers, which are particularly fitted or inserted into these recesses in a form-locking manner to ensure optimal arrangement of the reflector component within the box. Attached Figure Description

[0016] Other advantages, as well as preferred features and combinations thereof, are particularly evident from the foregoing description and from the claims. The invention will now be described in more detail based on the accompanying drawings. For this purpose, it is shown that:

[0017] Figure 1 A simplified cross-sectional view is shown of the media container with an advantageous sensor device, and

[0018] Figure 2A perspective view of the sensor device is shown. Detailed Implementation

[0019] Figure 1 A simplified side view shows an advantageous media tank 1 configured to receive and supply liquid and / or gaseous media 2, in this embodiment configured to receive liquid exhaust gas aftertreatment agent. For this purpose, the media tank 1 is configured to be substantially cup-shaped and thus has sidewalls 3 extending above the periphery of the bottom 4.

[0020] A sensor device 5 is attached to the bottom 4. This sensor device is configured to sense the material properties of the medium located in the medium tank 1, particularly the urea content of the exhaust aftertreatment agent. For this purpose, the sensor device 5 has an ultrasonic transducer 6, which integrates an ultrasonic transmitter 7 and an ultrasonic receiver 8. The ultrasonic transducer 6 is arranged outside the medium tank 1. Therefore, the medium tank 1 has, for example, a groove-shaped recess 9 in the bottom 4, into which the ultrasonic transducer 7 is oriented in a form-locking manner. Since the ultrasonic transducer 6 is located outside the tank, it can achieve electrical contact in a simple manner, for example, via cable connection, and can be connected to the controller of a motor vehicle, particularly one with an exhaust aftertreatment agent tank. Here, the ultrasonic transducer 6 is oriented such that it transmits ultrasonic signals through the tank wall 3 into the tank 1 and can also receive ultrasonic signals reflected within the tank. To reflect the emitted ultrasonic signals, the sensor device 5 also has a reflector member 10, which is arranged entirely inside the medium tank 1 on the bottom 4. According to this embodiment, the reflector component 10 is constructed as a stamped and bent part.

[0021] Figure 2 This is a partial perspective view of the media tank 1, looking toward the bottom 4 and the reflector component 10 arranged on the bottom 4.

[0022] The reflector member 10 has a flat substrate 11, which, according to this embodiment, has two circular openings 12. The media tank 1 has two protrusions, particularly slot-shaped protrusions 13, in the bottom 4 corresponding to the openings 12, which are inserted into the openings 12 without gaps. Through the protrusions 13 inserted into the openings 12 in the bottom 4, the reflector member 10 is oriented in the media tank 1 via the bottom 4 in a form-locking manner and is preferably also held therein. Optionally, the reflector member 10 is additionally bonded to the bottom 4 to ensure a durable and reliable arrangement. Optionally, the corresponding protrusion 13 has an interference fit with the opening 12 corresponding to the protrusion, such that the reflector member 10 is pressed against the protrusion 13, thereby also ensuring a reliable and durable connection of the reflector member 10 to the bottom 4 of the media tank 1.

[0023] The substrate 11 of the reflector component 10 is constructed to be flat and extends in the direction of propagation of the ultrasonic signal of the ultrasonic transducer 6.

[0024] Multiple reflector springs bent outward from the bottom 4 of the box are constructed on the substrate 11, and these reflector springs respectively constitute the reflectors of the reflector component 10.

[0025] Specifically, a first reflector 14 is configured to face the ultrasonic transducer 3, such that the signal emitted by the ultrasonic transducer 6 falls onto the first reflector 14. Here, the first reflector 14 is constructed such that it reflects the ultrasonic signal back to the ultrasonic transducer 6 and / or a second reflector 15, which faces the first reflector 14, for example, at the height of the ultrasonic transducer 6. The second reflector 15 is also integrally constructed with the reflector member 10 and the substrate 11. The first reflector 14 has a first reflector surface 16, and the second reflector 15 has a second reflector surface 17. The two reflector surfaces 16 and 17 are respectively formed by a bent reflector spring 18 or 19 of the reflector member 10.

[0026] Here, reflector surfaces 17 and 16 are positioned opposite each other such that the ultrasonic pulse generated by the ultrasonic transmitter 6 reaches the first reflector 14 and returns to the ultrasonic transmitter, thereby forming the first measurement path M1. Furthermore, a portion of the ultrasonic signal is also reflected to the second reflector 15 due to wave propagation; this portion is guided from the second reflector back to the first reflector 14 and from there to the ultrasonic transducer. This forms the second measurement path M2.

[0027] At least a portion of the measurement path M2 is formed solely by the reflector component 10, specifically between the first reflector 14 and the second reflector 15. These two measurement paths M1 and M2 relate to the effects of aging, temperature, and other factors that could damage the media tank 1 and the materials of the reflector component 10. In particular, the measurement path M2 provides the advantage of reliable reference measurement. The reflector component 10 is constructed such that the measurement path M2 extends in a V-shape, thereby optimizing the use of available installation space in the media tank 1 and optimizing the length of the measurement path, thus improving measurement accuracy.

[0028] Optionally, the reflector member 10 has a third reflector reed 20 configured with a third reflector surface 21, which also faces the ultrasonic transducer 6, such that an alternative first measurement path M1' is constructed between the third reflector surface 21 and the ultrasonic transducer, eliminating the need for direct reflection of the ultrasonic signal back to the ultrasonic transducer 6 from the third reflector surface 16. Accordingly, the third reflector surface 16 can be optimized and configured to feed the ultrasonic signal to the second reflector 15. Preferably, as shown, the third reflector surface 21 is arranged closer to the ultrasonic transducer 6 or the reflector surface 17.

[0029] All three reflector reeds 20, 18, and 19 are constructed as reflector reeds that bend simultaneously, particularly vertically, toward the same side of the substrate 11, and these reflector reeds are integrally connected to each other via the substrate 11. The precise manufacturing of the reflector component 10 also avoids the need for determining the measurement path required for wet calibration. Furthermore, based on the reference measurement path, the arrangement of the ultrasonic transducer 6 outside the dielectric chamber 1 is no longer important for determining the accuracy of material properties.

Claims

1. A sensor device (5) configured to determine the material properties of a gaseous and / or liquid medium, and the sensor device being at least partially disposed in the medium, the sensor device comprising: at least one ultrasonic transmitter (7) for generating ultrasonic signals; at least one first reflector (14) disposed opposite to the ultrasonic transmitter (7) at a distance from it; and at least one ultrasonic receiver (8) for receiving ultrasonic signals reflected from the first reflector (14), wherein, The path of the ultrasonic signal from the ultrasonic transmitter (7) to the first reflector (14) and from the first reflector (14) to the ultrasonic receiver (8) forms a first measurement path (M1, M1'); and a second reflector (15) is positioned opposite the first reflector (14) such that the ultrasonic signal travels from the ultrasonic transmitter (7) to the first reflector (14), from the first reflector (14) to the second reflector (15), and from the second reflector (15) to the receiver (8). The first reflector (14) and the path from the first reflector (14) to the ultrasonic receiver (8) form a second measurement path (M2), wherein the reflectors (14, 15) are integrally constructed with a common carrier element as a reflector member (10), characterized in that the reflector member (10) is a stamped and bent piece and has a flat substrate (11) as a carrier element, and the reflectors (14, 15) are bent out from the substrate on the same side of the substrate (11) as reflector springs (18, 19, 20).

2. The sensor device according to claim 1, characterized in that, The substrate (11) has a device for fastening the substrate (11) to a media tank (1) having the medium.

3. The sensor device according to claim 2, characterized in that, The substrate (11) has at least one opening (12) as the device, and in order to orient and secure the reflector member (10) in the media box (1), the protrusion (13) of the media box (1) can be inserted into the at least one opening at least substantially without gaps.

4. The sensor device according to any one of claims 1 to 3, characterized in that, The first reflector (14) has a first reflector surface (16) formed by a first reflector reed (18) in the reflector reed, so as to reflect the ultrasonic signal at least back to the ultrasonic receiver (8).

5. The sensor device according to claim 4, characterized in that, The second reflector (15) has a second reflector surface (17), which is formed by a second reflector reed (19).

6. The sensor device according to claim 5, characterized in that, The second reflector surface (17) is configured to reflect the ultrasonic signal at least back to the first reflector surface (16).

7. The sensor device according to claim 5, characterized in that, The first reflector (14) has a third reflector surface (21) formed by a third reflector reed (20) for reflecting ultrasonic signals from the ultrasonic transmitter (7) to the second reflector (15), and the second reflector surface (17) is configured to reflect the ultrasonic signals back to the third reflector surface (21), which reflects the ultrasonic signals to the ultrasonic receiver (8).

8. The sensor device according to any one of claims 1 to 3, characterized in that, The ultrasonic transmitter (7) and the ultrasonic receiver (8) are configured as an ultrasonic transducer (6).

9. The sensor device according to claim 1, characterized in that, The liquid medium is a liquid waste gas after-treatment agent.

10. A media tank (1) for receiving liquid and / or gaseous media, the media tank having a sensor device (5) for determining the material properties of the media, characterized in that, The sensor device is configured as described in any one of claims 1 to 9.

11. The media tank according to claim 10, characterized in that, The substrate (11) is arranged on the bottom (4) of the medium box (1) and placed inside the medium box, and the ultrasonic transmitter (7) and the ultrasonic receiver (8) are arranged outside the medium box on the medium box (1).

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