Active sensor with truck-specific housing

Abstract

The present invention relates to a sensor device (S), in particular a rotational speed sensor, for commercial vehicles. The sensor device (S) has a chip (1) with a sensor arranged in a housing (3), the chip (1) is arranged watertight with respect to the surroundings, and no metal is provided between the chip (1) and the object (O) to be sensed. Therefore, disruptive eddy currents can be avoided, and the watertightness ensures a long service life of the sensor.

Description

[Technical Field]

[0001] The present application relates to sensors, in particular active rotation speed sensors, with truck-specific housings.

[0002] In commercial vehicles, wheel rotation speed sensors are used, among other things, for anti-lock braking systems (ABS), electronic braking systems (EBS), electronic stability programs (ESP) as well as autonomous driving.

[0003] In anti-lock braking systems (ABS), for example, the rotation speed of each individual wheel is detected. Passive, i.e., coil-based, rotation speed sensors are provided, particularly in commercial vehicles, and these have no further functions. In trucks, passive rotation speed sensors are fixed using clamping sleeves. However, so-called active rotation speed sensors (based on Hall or MR technology), particularly in the private automobile sector, also exist. These sensors are mounted with their poles oriented toward the magnetic pole wheel or encoder wheel.

[0004] Active rotational speed sensors have several advantages since they can incorporate several functions.Such sensors also have to be appropriately assembled or fixed at their place of use.

[0005] The prior art is known, for example, from German Patent Application No. 102004028818. This document discloses a rotational speed sensor with a housing that can be inserted into a socket, where the sensor is arranged inside the housing. Contact elements connected to the sensor connect the sensor to the outside of the housing. The housing can be inserted into the socket accordingly.

[0006] Commercial vehicles require a different electrical path than private cars as commercial vehicles are usually significantly larger and therefore special measures must be taken regarding EMC (electromagnetic compatibility).

[0007] The object of the present invention is therefore to provide an axially displaceable rotational speed sensor that is highly robust with respect to electromagnetic compatibility. This object is achieved by the sensor device according to claim 1. Further advantageous embodiments of the invention are the subject of the respective dependent claims.

[0008] The sensor device according to the present invention includes a chip with a sensor arranged in a housing, the chip being arranged watertight relative to the surroundings, and no metal being provided between the chip and the object to be sensed.

[0009] This not only ensures extremely high mechanical robustness, but also ensures extremely high electromagnetic compatibility robustness, as there is no metal interference near the chip (or in the direct path between the sensor and the object to be sensed), and damage to the chip is also avoided.

[0010] Preferably, such a chip is a Hall element, preferably configured as a rotation speed sensor, more preferably a 2D / 3D Hall element, an R sensor, a GMR sensor or a TMR sensor.

[0011] Such sensors are particularly used in commercial vehicles. Preferably, the chip includes at least two active sensing areas. Three active sensing areas may be provided, for example, if rotation speed and direction are to be detected.

[0012] The housing can be made of metal. The housing may also comprise a ceramic material or a composite material.

[0013] Preferably, the housing has a cylindrical, prismatic, or rectangular parallelepiped shape, and the tip is disposed near an end face of the housing. The end face is provided with a bore, the extension length of which preferably corresponds at least to the extension length of the tip. This ensures that there is no metal between the tip and the object to be sensed (e.g., a magnetic pole wheel or an encoder wheel) that may interfere with electromagnetic detection in this case.

[0014] This preferably achieves that there is no metal between the active sensing area of ​​the chip and the object to be sensed.

[0015] More preferably, the housing is tubular, eliminating the end faces and again eliminating metal between the tip and the object to be sensed (e.g., a magnetic pole wheel or an encoder wheel). Furthermore, the manufacturing costs of a small tube (only a tubular periphery) are significantly lower than those of a sleeve. This also reduces eddy currents in the area of ​​the sensor tip, thereby improving electromagnetic compatibility.

[0016] Preferably, the housing has a collar on its end face located near the tip, the collar extending in the direction of the central axis of the housing, and preferably the collar has at least one hole, which hole is used to allow water that has collected inside the housing in that location to flow out of the housing without reaching the tip.

[0017] More preferably, the chip is mounted on a fixed section of a chip support, which is arranged inside the housing. The chip support further preferably has a first holding section and a second holding section, where the first holding section is arranged opposite a first opening in the housing and the second holding section is arranged opposite a second opening in the housing. Here, the holding sections can be firmly held by a corresponding stamp (an external holding device for the injection molding process).

[0018] More preferably, the housing is filled with a polymer matrix that surrounds the chip support, which makes it possible to hold the chip support within the housing when the stamp is present and then carry out injection molding.

[0019] More preferably, the chip support has a plurality of ribs adapted to tightly abut the inside of the housing, which may be configured as fused ribs that securely seal the chip support to the housing, so that water cannot migrate inside the housing, particularly into the area where the chip is located.

[0020] In another embodiment, the housing consists of a thermosetting material that completely surrounds the chip and preferably also the chip support, in this embodiment a sleeve or tube that externally defines the sensor device is no longer necessary.

[0021] Preferably, the sensor device is axially displaceable relative to the object to be sensed, which is particularly advantageous when detecting the rotational speed of individual wheels.

[0022] Preferably, the sensor device is used in a commercial vehicle.

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. [Brief explanation of the drawings]

[0024] [Figure 1] 1A and 1B show a sensor device according to the prior art, where FIG. 1A shows a cross-sectional view and FIG. 1B shows an isometric view. [Figure 2] 2A and 2B show a first embodiment of the present invention, where FIG. 2A is a cross-sectional view, FIG. 2B and FIG. 2C show detailed views of one side of the sensor device, FIG. 2D is an isometric view of the sensor device, and FIG. 2E shows a front view of the sensor device. [Figure 3] FIG. 4 is a cross-sectional view showing a second embodiment of a sensor device according to the present invention. [Figure 4] 4A and 4B show a third embodiment of the present invention, where FIG. 4A shows a cross-sectional view and FIG. 4B shows an isometric view. [Figure 5] 5b) and 5c) show corresponding partial views of the corresponding first and second holding sections, respectively, during the manufacture of the sensor device (according to the first, second or third embodiment), in particular during injection molding of the base material around the chip support. [Figure 6] 6A and 6B show a fifth embodiment of the invention, in which Fig. 6A shows in particular the chip carrier and Fig. 6B shows the corresponding isometric view. [Figure 7] 7A and 7B are diagrams showing a fifth embodiment of the present invention, in which FIG. 7A is an isometric view and FIG. 7B is a front view.

[0025] In FIG. 1 a ) a sensor device S according to the prior art is shown in cross section.

[0026] The chip 1 is mounted on a chip support 2, specifically on a chip fixing section 2c. The chip support 2 further comprises a first holding section 2a and a second holding section 2b. The chip support 2 with the chip 1 is mounted in a housing 3, which is here formed as a sleeve, i.e., cylindrical, and has a corresponding peripheral wall and a lid. Furthermore, a seal 6 is provided on the outside of the housing 3. On the side opposite the chip 1, a cable 5 is provided, connecting the housing 3 to the environment. The chip support 2 is fixed inside the housing 3, which is injection-molded from a polymer matrix 4. A first opening 3b is provided in the housing 3 for the first holding section 2a, and correspondingly, a second opening 3c is provided in the housing for the second holding section 2b.

[0027] 1b) shows an isometric view of a sensor device S according to the prior art. From this view it can be seen that the cable 5 exits from the housing 3 and that here a first opening 3b is provided in the housing. The first opening 3b is not shown in this view.

[0028] In Fig. 2a) a view similar to Fig. 1 is shown, now according to a first embodiment of the invention. It can be seen from this view that a large bore 3a is provided in the end face of the housing 3, so that there is no metal between the area where the tip 1 extends upward and the object O to be sensed (not shown here). All other sections of this view are exactly the same as in Fig. 1a).

[0029] FIG. 2b) shows a detailed view, again revealing the bore 3a. Furthermore, a corresponding collar 3e is provided, which extends slightly in the direction of the central axis of the housing 3. Here, the collar is L-shaped. FIG. 2c) also shows the collar 3e, but in this view, it is U-shaped. FIG. 2d) shows a symmetrical view, again showing the housing 3 and the first opening 3b. Here, the bore 3a is clearly visible at the end face, and multiple holes 3d are provided on the collar 3e. These holes serve to allow liquid to easily flow out of the interior area of ​​the housing 3. At the same time, the polymer matrix 4 (not shown) ensures that the tip is absolutely watertight from the surroundings. FIG. 2e) shows a front view, again showing the opening 3a with the holes 3d corresponding to the collar 3e.

[0030] A second embodiment of the invention is shown in Figure 3. This view is similar to Figure 2a), with the difference that in Figure 3 two more seals 6 are arranged on the outside of the housing 3, i.e. one seal on each side of the housing 3. In this case too there is a sleeve-shaped, i.e. cylindrical, circumferential wall and a lid.

[0031] 4a) shows a third embodiment of the invention, in which the housing 3 is formed as a tube, i.e., has no end faces or lids, but only a peripheral wall. Similarly, the first and second holding sections 2a and 2b are shown to be arranged relative to the corresponding first and second openings 3b and 3c.

[0032] In FIG. 4b) an isometric view of a third embodiment is shown, again showing a housing 3 with a corresponding second opening 3c.

[0033] 5a) shows a state during the manufacturing process of the sensor device, in particular, it is disclosed that a first stamp S1 can be inserted through the first opening 3b and a second stamp S2 can be inserted through the second opening 3c, and these stamps respectively hold the chip carriers 2 (the first stamp S1 holds the first holding section 2a, and the second stamp S2 holds the second holding section 2b), while injection molding is carried out using a polymer base material 4.

[0034] 5b) shows two states during the injection molding process, showing how the second holding section 2b is correspondingly held from multiple sides by the second stamp S2. The left-hand image shows that the stamp S1 fixes the star-shaped section of the second holding section 2b, and then the corresponding area of ​​the polymer matrix is ​​cut out. The right-hand image shows a further state, in which the second stamp S2 is moved slightly away from the second holding section 2b, so that the immediate periphery of the second holding section 2b is injection molded. This ensures that there are no holes in the polymer matrix 4, and that the polymer matrix 4 seals the chip element 1 (not shown here) against the surroundings in a completely watertight manner.

[0035] 5c) shows how the first holding section 2a is correspondingly held by the first stamp S1. Here, a two-stage injection molding process, as shown in FIG. 5b), is not performed. In this case, multiple holes may actually occur, but these are located far away from the sensor element 1, as can be seen in FIG. 5a).

[0036] 6a) shows a fourth embodiment of the invention, again showing only one chip carrier 2 with a first holding section 2a and a second holding section 2b.

[0037] A number of ribs 7 are provided along the chip support 2, which may be formed, for example, as melt ribs (which melt, for example, when heated, thereby achieving a sealing effect), and which enable the chip support 2 to be sealed in a correspondingly watertight manner relative to the housing 3 (not shown here), so that no water can reach the chip 1 in the direction corresponding to the chip fixing section 2c.

[0038] In FIG. 6b) a corresponding isometric view of a chip carrier 2 according to a fourth embodiment is shown.

[0039] FIG. 7 a) shows a fifth embodiment of the invention in an isometric view. A housing 3 is again provided, from which a cable 5 exits accordingly. However, here the tip 1 and tip support 2 (not shown) are completely enclosed by the thermosetting housing 3, i.e., the tip 1 and tip support 2 (not shown here) are correspondingly injection-molded from Duroplast. Two cutouts 9 are provided in the housing 3, into which corresponding engagement sections 8 of the clamping sleeve can engage, thereby making the housing correspondingly more robust. FIG. 7 b) shows a view from the front, again showing in more detail the positions of the two engagement sections 8 a of the clamping sleeve 8 in the corresponding cutouts 9.

[0040] The present invention is not limited to the above-described embodiments.

[0041] Injection molding can also be carried out with other materials, such as rubber, elastomer or other watertight materials. [Explanation of symbols]

[0042] S sensor device 1 chip 2 Chip support 2a First holding section 2b Second holding section 2c Tip fixing section 3. Housing 3a Boa 3b First opening 3c Second opening 3d hole 3e color 4. Polymer matrix 5 Cable 6 Seals 7. Ribs 8 Clamp sleeve 8a Engagement section 9 Notch 51 First Stamp 52 Second Stamp O Object

Claims

1. A sensor device (S), The sensor device (S) comprises a chip (1) with a sensor mounted in a housing (3), The chip (1) is arranged watertightly with respect to the surroundings, and no metal is provided between the chip (1) and the object (O) to be sensed. Sensor device (S).

2. 2. The sensor device according to claim 1, wherein the chip (1) is a Hall element, preferably a 2D or 3D Hall element, an MR sensor, a GMR sensor or a TMR sensor, which is preferably configured as a rotational speed sensor, and the chip (1) further preferably comprises at least two active sensing areas.

3. 3. The sensor device (S) according to claim 1 or 2, wherein the housing (3) has a cylindrical, prism or rectangular parallelepiped shape, the chip (1) is arranged near an end face of the housing (3), and a bore (3a) is provided in the housing, and the extension length of the bore (3a) preferably corresponds to at least the extension length of the chip (1).

4. 3. The sensor device (S) according to claim 1 or 2, wherein the housing (3) is tubular.

5. 5. The sensor device (S) according to claim 4, wherein a collar (3e) extending in the direction of the central axis of the housing (3) is provided on the end face of the housing (3) adjacent to which the chip (1) is arranged, and preferably at least one hole (3d) is provided in the collar (3e).

6. The sensor device (S) according to any one of claims 1 to 5, wherein the chip (1) is provided on a chip fixing section (2c) of a chip support (2), and the chip support (2) is arranged within the housing (3).

7. The chip support (2) further comprises a first holding section (2a) and a second holding section (2b); The first holding section (2a) is arranged opposite a first opening (3b) in the housing (3), and the second holding section (2b) is arranged opposite a second opening (3c) in the housing (3). A sensor device (S) according to claim 6.

8. 8. The sensor device (S) according to claim 6 or 7, wherein the housing (3) is filled with a polymer matrix (4) which surrounds the chip support (2).

9. 8. The sensor device (S) according to claim 6 or 7, wherein the chip support (2) further comprises a plurality of ribs (7) adapted to tightly abut the inside of the housing (3).

10. 8. The sensor device (S) according to claim 1, wherein the housing (3) is made of a thermosetting material that completely surrounds the chip (1) and preferably also the chip carrier (2).

11. 11. The sensor device (S) according to claim 1, wherein the sensor device (S) is axially displaceable relative to the object to be sensed.

12. 12. Use of a sensor device (S) according to one of claims 1 to 11 in a commercial vehicle.

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