Abstract
In a device for measuring a fill level of a liquid in a reservoir with an ultrasonic sensor, wherein the ultrasonic sensor is arranged at the bottom end of a damping cup with a measuring tube, wherein electronic components are assigned to the ultrasonic sensor, the electronic components are encapsulated in sealing manner against the liquid that is to be measured between a floor of an electronics installation space and a cover arranged above the floor, so that the electronics installation space forms and encapsulated area. At least one support is provided inside the electronics installation space and connects the cover in force-fitting manner with the electronics installation space.
Claims
1. A device for measuring a fill level of a liquid in a reservoir with an ultrasonic sensor, wherein the ultrasonic sensor is arranged at the bottom end of a damping cup with a measuring tube, wherein electronic components are assigned to the ultrasonic sensor, wherein the electronic components are encapsulated in sealing manner against the liquid that is to be measured between a floor of an electronics installation space and a cover arranged above the floor, so that the electronics installation space forms and encapsulated area, and at least one support is provided inside the electronics installation space, connecting the cover in force-fitting manner with the floor of the electronics installation space.
2. The device according to claim 1, wherein the lengthwise extension of supports is greater than the diameter of the measuring tube.
3. The device according to claim 1, wherein two parallel supports are provided.
4. The device according to claim 3, wherein the parallel supports are arranged symmetrically about the measuring tube.
5. The device according to claim 1, wherein the support forms a closed geometrical structure.
6. The device according to claim 5, wherein the closed geometrical structure is arranged symmetrically about the axis of the measuring tube.
7. The device according to claim 5, wherein the closed geometrical structure forms a square.
8. The device according to claim 1, wherein the support is made as a single part with the cover.
9. The device according to claim 1, wherein the support is connected to the floor of the electronics installation space via a force-fitting bonded joint.
10. The device according to claim 9, wherein the supports have a triangular profile at the foot thereof.
11. The device according to claim 1, wherein the cover and the floor of the electronics installation space are connected in the edge area via a bonded joint.
12. An internal combustion engine, in particular for a motor vehicle having an oil-lubricated engine, wherein the oil-lubricated engine is equipped with a device according to claim 1 for measuring the fill level of the engine oil.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the following, the invention will be explained further with reference to an exemplary embodiment thereof represented in the drawing. The diagrams in the individual figures of the drawing show the following:
[0011] FIG. 1: a schematic representation of a device according to the invention;
[0012] FIG. 2: a sectional view of the lower part of a device according to the invention;
[0013] FIG. 3: a view of a part of the electronics installation space from below;
[0014] FIG. 4: an enlarged representation of a cross-section through a support, and
[0015] FIG. 5: another embodiment of the invention in a schematic representation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] FIG. 1 is a highly simplified schematic representation of device 1 with a damping cup 2. Though not shown individually here, measuring tube 3 is located in the middle of damping cup 2, and ultrasonic sensor 7, which transmits the ultrasonic waves into measuring tube 3 from below, is located at the foot of measuring tube 3. Ultrasonic sensor 7 is positioned underneath a cover 5 and above a floor 6 of an electronics installation space 4, in which electronic components and elements for controlling the ultrasonic sensor are arranged. Optionally, the space may also accommodate other components for signal processing and signal analysis. Electronics installation space 4 is encapsulated to keep it separate from the surrounding medium. For this purpose, sealing connections between cover 5 and floor 6 of electronics installation space 4 are provided in the external area, which is not shown here. In this context, it is essential for the purposes of the invention that supports 8 and 9 are provided and present inside the encapsulated electronics installation space 4 and serve to absorb both tensile and compressive forces as well as shearing forces. Vibrations that are generated exert very high loads on device 1, in particular on damping cup 2, and on the components of device 1 close to the floor. These forces increase with the height of installation of damping cup 2. The action of forces is indicated by a double-headed arrow. Supports 8 and 9 absorb the tensile and compressive forces. This is represented by the double-headed arrows. Supports 8 and 9 also absorb horizontal shearing forces. The effect of the invention and additionally provided supports 8 and 9 and box structure created thereby is to reduce the relative movement between cover 5 and floor 6 of electronics installation space 4 and to reduce the transmission of forces to the electronics. The overall effect thereof is to make it possible to increase the length of device 1, particularly the height of damping cup 2, without overloading the electronics.
[0017] FIG. 2 shows a cross-section through the lower part of damping cup 2, also showing the central measuring tube 4 and an antechamber 10. The bottom of device 1 is delimited by a flange 11, on which the floor 6 of electronics installation space 4 is arranged. The electronics installation space 4 situated above this is defined upwardly by cover 5. The encapsulation of electronics installation space 4 is assured by a peripheral bond, particularly a bonded joint 12, between cover 5 and floor 6. Cover 5 has a central cutaway 16 which corresponds to measuring tube 3 and in which the ultrasonic sensor 7 is arranged. In order to protect the encapsulation of electronics installation space 4, ultrasonic sensor 7 is fastened to cover 5 by means of a sealed, bonded joint 13. Generally, another type of connection would also be possible. At any rate, the connection must ensure that the encapsulation remains intact and electronics installation space 4 remains sealed. Support 8, 9 is provided inside electronics installation space 4, realised in this case as parallel struts arranged on both sides of measuring tube 3 and on both sides of ultrasonic sensor 7. The length of support 8, 9 in the x-direction or alternatively in the Y-direction is greater than the diameter of the measuring tube and/or greater than the edge length of ultrasonic sensor 7. Supports 8 and 9 are arranged symmetrically on both sides of measuring tube 3. In this example, supports 8 and 9 are constructed as a single part with cover 5 and connect the cover in force-fitting manner to the floor 6 of electronics installation space 4. A bonded joint 14 is provided for this purpose, with which the lower ends of supports 8 and 9 are joined to floor 6 of electronics installation space 4. The bottom termination of support 8, 9 is formed with a triangular recess in the profile, thus forming a triangular profile. This might also be described as a central, lengthwise recess or groove. It serves to enhance the effect of a force-fitting bonded joint 14.
[0018] FIG. 3 is a perspective view of cover 5 from below. Only a portion thereof is represented here, particularly showing cutaway 16 in cover 5, to which ultrasonic sensor 7 is fastened from below. Cutaway 16 represents an extension of the adjoining measuring tube 3. Supports 8 and 9, in the form of struts, are arranged symmetrically on both sides of the cutaway, and are each longer than the diameter of cutaway 16 and/or of measuring tube 3. A triangular profile 15 is apparent at the foot of supports 8 and 9, visible here because of the view looking up from below, and serves to collect adhesive from the bonded joint 14 which must be made, thereby ensuring a particularly good force-fitting bond with floor 6.
[0019] FIG. 4 is an enlarged representation of a cross-section through a support 8, which is formed integrally on cover 5. Here too, the force-fitting connection with the floor 6 of electronics installation space 4 is shown particularly clearly, wherein the bottom end area of support 8 has a triangular profile 15, where the bonded joint 14 is made.
[0020] FIG. 5 also shows entirely schematically a further embodiment of support 8, 9. In this case, not just two parallel supports or one support is/are present, but instead a closed geometrical structure 17 is formed. Ultrasonic sensor 7 is positioned inside this closed structure 17. Support 8, 9 thus forms a closed, box-like structure 17, surrounding ultrasonic sensor 7 and directing the vibration forces that act on the damping cup directly into the floor 6 of electronics installation space 4, thus relieving the external joints, particularly the bonded joints 12 between cover 5 and floor 6 of electronics installation space 4. Closed structure 17 may be constructed as a closed rectangle, a closed triangle, a closed circle, or even a closed rhombus.
[0021] All of the features described in the preceding description, as well as those in the claims, can be implemented in any order and combination with the features of the independent claim. The disclosure of the invention is thus not limited to the feature combinations that are described and/claimed, but all feature combinations practicable within the scope of the invention are rather to be considered disclosed.
