CN111373268A

CN111373268A - Sensor unit for a vehicle

Info

Publication number: CN111373268A
Application number: CN201880075538.5A
Authority: CN
Inventors: M·施利茨库斯; S·莱恩伯格; S·海姆; H·塞班德; V·诺特曼
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-11-23
Filing date: 2018-09-20
Publication date: 2020-07-03
Also published as: WO2019101390A1; KR102644396B1; KR20200087164A; DE102017220905A1

Abstract

The invention relates to a sensor unit (1) for a vehicle, comprising a sensor carrier (10) which forms a mechanical interface (10A) for the sensor unit (1) and carries a circuit board (3) on which an electronic circuit (5) having at least one vibration-sensitive sensor element (5A) is arranged. The sensor carrier (10) has a fastening flange (12) on a first surface (13) of which, facing the circuit board (3), a first engagement geometry (14) is arranged, which at least partially receives a first edge (3.1) of the circuit board (3) in such a way that the first circuit board (3) is oriented perpendicular to the first surface (13), wherein a second engagement geometry (16) is arranged on a second surface (15) of the fastening flange (12) opposite the first surface (13), by means of which the sensor carrier (10) can be connected to a mechanical system in a force-fitting and/or form-fitting manner.

Description

Sensor unit for a vehicle

Technical Field

The invention relates to a sensor unit for a vehicle of the type described in independent claim 1.

Background

For controlling the vehicle brake system, vibration-sensitive acceleration sensors and rotation speed sensors are used, which are installed as standard in separate sensor units in the vehicle. In modern vehicle brake systems, these vibration-sensitive sensors are arranged on a circuit board in the control unit of the brake system. Thereby, the installation in the vehicle can be made easy and costs can be saved. However, there the sensor is subjected to a vibration chain which extends from the housing, via the components of the controller, up to the circuit board. In order to decouple the vibration-sensitive sensor from undesired resonances in the system, the sensor is usually arranged on a damping circuit board soldered to the controller circuit board. The sensor position is predefined by the vibration behavior of the circuit board. This means that the vibration-sensitive sensor is arranged on the control board in an area which vibrates as little as possible and the measuring direction of the sensor depends on the position of the board. Extremely high expenditure is required for decoupling vibration-sensitive acceleration and rotation speed sensors from mechanical and electrical interference signals. Thereby additionally creating a correlation with the corresponding circuit board layout.

Furthermore, pressure sensor units having a circuit mount and a circuit board arranged perpendicularly to the circuit mount are known from the prior art. Thus, for example, document DE 102012204904 a1 discloses a sensor unit having a housing in which at least one pressure measuring cell and a circuit mount are arranged, which circuit mount has a circuit board arranged perpendicularly to the circuit mount, which circuit board comprises an electronic circuit with at least one electronic and/or electrical component. The measuring unit has at least one connection point, via which at least one electrical output signal of the measuring unit can be intercepted. The circuit mount forms an internal interface which intercepts at least one electrical output signal of the measuring unit and loads it onto the electronic circuit. The output signal of the electronic circuit can be intercepted by an external interface. The inner connection is formed at a first end of the sheath and the outer connection is formed at a second end of the sheath. The sheath engages a sensor mount on a first end, the sensor mount having a mounting flange and a measurement connection configured as a self-biting connection. The fastening flange has a flange edge, on which the sheath is supported and by means of which the sensor unit can be pressed together with the fluid mass. Furthermore, the fastening flange comprises a connecting region, against which the jacket is pressed. The measuring unit is placed on the tubular support of the fastening flange and welded thereto. Furthermore, the measuring unit comprises a measuring membrane which deforms as a function of the fluid pressure on the measuring nipple.

Disclosure of Invention

The sensor unit for a vehicle having the features of the independent claim 1 has the advantage that: a rigid connection between the mechanical device and the electronic device is achieved and thus eigenvibrations of the sensor unit can be avoided or at least reduced. Due to the short vibration chain from the sensor carrier to the circuit board, the embodiment with the sensor unit according to the invention must be used with much less effort for decoupling the sensor unit from mechanical and electrical interference signals, so that the useful signal of the at least one sensor element is subjected to fewer interference signals. In this case, a better effective signal can be obtained without depending on the installation position and without depending on the vibration chain of the composite of the sensor unit to the mechanical system. The joint geometry of the sensor mount can be independently optimized without affecting the other components. In a change of the layout of the respective controller, a new safeguard procedure is usually undertaken, since a change of the vibration characteristics of the circuit board may occur due to mass shifts within the layout. By means of the embodiment of the sensor unit according to the invention, a standardized safeguarding process can be implemented, since the sensor unit is independent of the rest of the system, in particular of the layout of the controller circuit board, in contrast to known solutions in which a circuit board having at least one sensor element is coupled to the controller circuit board.

Embodiments of the present invention provide a sensor unit for a vehicle having a sensor carrier which forms a mechanical interface for the sensor unit and carries a circuit board on which at least one vibration-sensitive sensor element is arranged. The sensor carrier has a fastening flange, on a first surface of which facing the circuit board a first engagement geometry is formed, which at least partially receives the circuit board and is oriented at a predetermined angle relative to the first surface. Furthermore, a second engagement geometry is formed on a second surface of the fastening flange, which is opposite the first surface, by means of which the sensor carrier can be connected to the mechanical system in a force-fitting and/or form-fitting manner. Preferably, the circuit board is oriented perpendicularly to the first surface of the sensor carrier.

The term "mechanical system" can be understood here to mean a fluid block or a base housing of an electrical device, such as a pump of a control unit, for example, a brake control unit, to which an embodiment of the sensor unit according to the invention can be coupled. For this purpose, the mechanical system has a corresponding receiving geometry which can be engaged with the second engagement geometry of the fastening flange.

By "sensor unit" can be meant a structural unit which comprises at least one vibration-sensitive sensor element which directly or indirectly detects a physical variable or a change in a physical variable and preferably converts it into an electrical sensor signal. For example, sensor elements can be considered which detect an acceleration in a predetermined direction or a rotational speed about a predetermined spatial axis, respectively. For example, the detected sensor signals can be edited and/or processed and/or evaluated by an electronic circuit integrated in the sensor unit. Alternatively, the external electronic circuit can edit and/or further process and/or evaluate the sensor signal. The internal or external electronic circuit can comprise at least one electrical and/or electronic component and/or at least one conductor track and/or at least one contact point. In this way, any function, such as, for example, evaluation, editing, amplification, filtering, etc., can be advantageously implemented for processing and outputting the sensor signal. Furthermore, the contact elements of the at least one sensor element can be brought into electrical contact with corresponding contact points of the electronic circuit, which can intercept at least one electrical output signal of the at least one sensor element and load it onto the electronic circuit. The term "electronic circuit" can also refer to an integrated circuit, such as, for example, a so-called system ASIC (ASIC: application specific integrated circuit), which compiles and further processes or evaluates the detected sensor signals. Furthermore, the electronic circuit can have at least one interface, which can be embodied in hardware and/or in software. When embodied in hardware, the interface can be, for example, part of a system ASIC, which contains and executes the various functions of the electronic circuit. However, it is also possible for the interface to be an integrated switching circuit of its own or to be formed at least partially from discrete components. When implemented in software, the interface can be a software module, which can also be present on the microcontroller, for example, in addition to other software modules. Also advantageous is a computer program product having a program code which is stored on a machine-readable carrier, such as a semiconductor memory, a hard disk memory or an optical memory, and which is used to carry out an evaluation when the program is executed by an electronic circuit. Furthermore, a plurality of vibration-sensitive sensor elements can form a so-called inertial sensor, which can detect a plurality of accelerations and/or rotational speeds.

By the measures and refinements recited in the dependent claims, advantageous refinements of the sensor unit specified in the independent claim 1 can be achieved.

It is particularly advantageous if the sensor carrier with the first and second coupling geometries is a rotationally symmetrical lathe. Thereby, the sensor unit can be arbitrarily oriented when engaged with a mechanical system. Due to the rotationally symmetrical design of the sensor carrier, the measuring direction or the measuring axis of the at least one sensor element can be adapted to the installation position of the mechanical system. This means that the measuring direction or the measuring axis of the at least one sensor element can be oriented arbitrarily with respect to the pressing-in axis.

In an advantageous embodiment of the sensor unit, the first engagement geometry can be a support geometry with a U-shaped receiving groove, the width of which is adapted to the thickness of the circuit board. In this case, the first edge of the circuit board can be held in the receptacle groove in a force-fitting and/or material-fitting manner. This means that the first edge of the circuit board can be pressed into the receiving groove. Additionally or alternatively, the first edge of the circuit board can be glued into the receiving groove.

In a further advantageous embodiment of the sensor unit, the second engagement geometry can be a self-locking geometry or a knurled geometry or an external thread and is received by a corresponding receiving geometry of a mechanical system. The sensor carrier can thus advantageously provide a receiving geometry for the circuit board on one side and a connection geometry with respect to the mechanical system on the other side. The sensor mount thus enables an easy and rigid connection between the mechanical system and the circuit board, which provides advantages in terms of natural resonance. The sensor carrier can be pressed, for example, into a corresponding receiving opening in the mechanical system by means of the self-locking geometry or the knurled geometry, for producing a non-positive connection, or screwed together by means of an external thread with a threaded opening in the mechanical system, for producing a non-positive connection.

In a further advantageous embodiment of the sensor unit, the contact unit can form an external electrical interface having at least one external contact point for the at least one vibration-sensitive sensor element. Furthermore, the contact unit can have a third engagement geometry, which at least partially accommodates the circuit board. The circuit board can thus be inserted at least partially into the third engagement geometry of the contact unit, which is configured as a receiving opening. Furthermore, the at least one external contact point can be electrically connected to a corresponding contact point of an electronic circuit on the circuit board. The electrical connection between at least one external contact point of the contact unit and the corresponding contact point on the circuit board is preferably established by means of a soldering process.

In a further advantageous embodiment of the sensor unit, a fourth engagement geometry of the connection for force-fitting and/or material-connecting the sheath can be formed between the first surface of the fastening flange and the first engagement geometry. The fourth engagement geometry is, for example, a step or a shoulder, the outer contour of which matches the inner contour of the jacket at its first end. The sleeve can thus be pressed, for example with the first end, against the step or shoulder until the sleeve rests against the first surface. Additionally or alternatively, the sheath can be glued to the sensor mount at the first end.

Furthermore, the contact unit can form a fifth engagement geometry that can be adapted to the inner contour of the sheath in such a way that the contact unit is guided in the sheath in a centered manner. Thus, the fifth engagement geometry can be, for example, an outer contour which matches an inner contour of the sheath at its second end. The contact unit can thus be pressed into the sheath, for example at the second end. Additionally or alternatively, the sheath can be glued to the contact unit at the second end. The assembly or mounting of the sensor unit can thereby be carried out in an advantageous manner easily and more quickly.

The sheath can be made of metal or plastic and provides protection against mechanical loads. Furthermore, the interior of the sheath can be filled at least partially with a damping medium via a through-opening in the sensor carrier. Thereby, the vibration characteristics of the sensor unit can be influenced in an advantageous manner. Thus, for example, specific damping characteristics can be set. The circuit board can be reinforced by a support geometry on the sensor mount or by a contact unit acting as a support unit in the housing and/or by an applied damping medium, so that the circuit board is protected against undesired vibrations and disturbances. Furthermore, the sheath provides an additional interface for electrical protection measures, so that the performance of the sensor unit with respect to electromagnetic compatibility (EMV) and/or electrostatic discharge (ESD) can be improved. The sensor unit can thus be decoupled mechanically and electrically from the remaining system in an advantageous manner.

Drawings

Embodiments of the invention are illustrated in the drawings and are explained in detail in the following description. In the drawings, the same reference numerals denote components or elements performing the same or similar functions.

FIG. 1 shows a schematic perspective view of an embodiment of a sensor unit according to the invention without a sheath;

fig. 2 shows a schematic perspective view of a first exemplary embodiment of the sensor carrier of the sensor unit according to the invention shown in fig. 1;

FIG. 3 shows a schematic perspective view of a second exemplary embodiment of a sensor carrier for a sensor unit according to the invention;

fig. 4 shows a schematic perspective view of an exemplary embodiment of a sensor unit according to the invention with a sheath.

Detailed Description

As can be seen from fig. 1 to 4, the illustrated exemplary embodiment of the sensor unit 1, 1A according to the present invention for a vehicle accordingly comprises a sensor carrier 10 and a circuit board 3, wherein the sensor carrier 10 forms a mechanical interface 10A for the sensor unit 1, 1A and at least one vibration-sensitive sensor element 5A is arranged on the circuit board 3. The sensor carrier 10 has a fastening flange 12, on a first surface 13 of which, facing the circuit board 3, a first engagement geometry 14 is formed, which at least partially receives the circuit board 3 and is oriented at a predetermined angle relative to the first surface 13. A second engagement geometry 16 is formed on a second surface 15 of the fastening flange 12 opposite the first surface 13, by means of which the sensor carrier 10 can be connected in a force-fitting and/or form-fitting manner to a mechanical system, not shown in detail.

The illustrated exemplary embodiment of the sensor unit 1, 1A according to the present invention can thus be connected to a fluid block or a base housing of a pump or a control unit, for example. For this purpose, the mechanical system, not shown, has a corresponding receiving geometry, which can be brought into engagement with the second engagement geometry 16 of the fastening flange 12 or the sensor mount 10.

As can be seen from fig. 1, the at least one vibration-sensitive sensor element 5A is integrated into an electronic circuit 5, which in the exemplary embodiment shown is a system ASIC and forms an inertial sensor that detects a plurality of accelerations in a predetermined spatial direction and/or a plurality of rotational speeds about a predetermined spatial axis.

As can be seen in fig. 1 to 4, the sensor carrier 10 with the first and second joining geometries 14, 16 is a rotationally symmetrical turned part.

As can be seen in fig. 1 to 3, the first engagement geometry 14 in the exemplary embodiment shown is a support geometry 14A with a U-shaped receiving groove 14.1, the width of which receiving groove 14.1 is adapted to the thickness of circuit board 3. In the exemplary embodiment shown, a first edge 3.1 of the printed circuit board 3, which corresponds to the lower edge of the printed circuit board 3 in the illustration, is thereby pressed into the receiving groove 14.1 and held in a force-fitting manner in the receiving groove 14.1. In addition or as an alternative, the first edge 3.1 of the printed circuit board 3 can be glued into the receiving groove 14.1 with an adhesive and held in a force-fitting manner in the receiving groove 14.1. In the exemplary embodiment shown, the printed circuit board 2 is oriented perpendicularly to the first surface 13 of the fastening flange 12. Of course, if necessary, it is also possible to orient the printed circuit board 3 obliquely to the first surface 13 of the mounting flange 12. In order to facilitate the insertion of the printed circuit board 3, a lead-in chamfer 14.2 is formed on each of the two edges of the receiving groove 14.1.

As can be seen in fig. 1, 2 and 4, in the first illustrated embodiment of the sensor carrier 10, the second engagement geometry 16 is a self-locking geometry 16A. The self-locking geometry 16A can be pressed together with a correspondingly drilled receiving geometry of the mechanical system and establishes a force-fitting and form-fitting connection.

As can also be seen from fig. 3, in the second illustrated embodiment of the sensor carrier 10, the second engagement geometry 16 is a knurled geometry 16B. The knurling geometry 16B is pressed together, analogously to the self-locking geometry 16A, with a correspondingly drilled receiving geometry of the mechanical system and establishes a non-positively and positively locking connection. In an embodiment of the sensor carrier 10, which is not shown in the drawing, the fastening flange 12 or the second engagement geometry 16 of the sensor carrier 10 is an external thread which can be screwed into a receiving geometry of a mechanical system, which is correspondingly designed as a threaded bore, and which establishes a force-fitting connection.

As can also be seen from fig. 1 and 4, the contact unit 20 forms an external electrical interface 20A having at least one external contact point 24 for at least one vibration-sensitive sensor element 5A. At least one electrical output signal of the electronic circuit 5 can be intercepted by the at least one external contact point 24. As can also be seen from fig. 1 and 4, the base body 22 of the contact unit 20 has a cylindrical shape and, in the exemplary embodiment shown, comprises two half-shells 22.1, 22.2, each of which has at least one external contact point 24 of the external electrical interface 20A. Furthermore, the contact unit 20 has a third engagement geometry 26, which at least partially accommodates the circuit board 3. In the exemplary embodiment shown, the base body 22 of the support unit 30 has a third engagement geometry 26, which is designed as a receiving opening and which is adapted to the outer contour of the circuit board 10 and at least partially receives the circuit board 3 at a second edge 3.2, which corresponds here to the upper edge of the circuit board 3. At least one electrical connection between at least one outer contact point 24 of the outer electrical contact points 20A and at least one corresponding inner contact point 25 of the circuit board 3 is established by at least one metallized through-hole formed in the base body 22, which is electrically connected to at least one associated contact point in the base body 22, which in turn is electrically and mechanically connected to at least one inner contact point 25 of the circuit board 3 and thus to the electronic circuit 5 by at least one solder connection. In the exemplary embodiment shown, the support unit 30 has four outer contact points 34, two outer contact points 24 being arranged on each half shell 22.1, 22.2.

As can also be seen from fig. 4, the illustrated second exemplary embodiment of the sensor unit 1A has a protective sleeve 7 in order to protect the sensor arrangement from mechanical stress. As can be seen in fig. 1, a fourth engagement geometry 18 of the connection for force-fitting and/or material-connecting the sheath 7 is formed between the first surface 13 of the fastening flange 12 and the first engagement geometry 14. In the exemplary embodiment shown, the fourth engagement geometry 18 is a step, the outer contour of which matches the inner contour of the jacket 7 at its first end 7.1, the first end 7.1 here being adapted correspondingly to the lower end of the jacket. The jacket 7 can thus be pressed with the first end 7.1 against the step until the jacket 7 rests against the first surface 13 of the fastening flange 12. In addition or alternatively, the sheath 7 can be glued to the sensor carrier 10 at the first end 7.1 or fixed by means of a welding or soldering point.

As can also be seen from fig. 1 and 4, the contact unit 20 forms a fifth engagement geometry 27, which is adapted to the inner contour of the sheath 7 at its second end 7.1 in such a way that the contact unit 20 is guided in the sheath 7 in a centered manner. As can also be seen from fig. 1 and 4, the outer contour of the contact unit 20 forms a fifth engagement geometry 27, so that the contact unit 20 can be pressed into the jacket 7 at the second end 7.1. In addition or alternatively, the sheath 7 can be glued to the contact unit 20 at the second end 7.2. In the illustrated exemplary embodiment of the sensor unit 1, 1A according to the invention, a spring-elastic contact element 28 is arranged on each half shell 22.1, 22.2 of the base body 22 of the contact unit 20, so that in the joined-together state two spring-elastic contact elements 28 are arranged on the outer contour of the base body 22, which contact elements facilitate centering of the contact unit 20 in the housing 7. Furthermore, in the exemplary embodiment shown, the base body 22 of the support unit 20 has a projecting edge 23 which, in the engaged state, closes the jacket 20. Dirt particles, chips or the like can thereby advantageously be prevented from reaching the interior of the jacket 7.

The sheath 7 can be made of metal or plastic and has, in the exemplary embodiment shown, an electrically conductive inner coating. Since an electrically conductive connection, which functions as a ground path, can be established between the circuit board 3 and the sheath 7 by means of the spring-elastic contact elements 28, the sheath 7 provides an additional interface for electrical protection measures, so that the performance of the sensor unit 1 with respect to electromagnetic compatibility (EMV) and/or electrostatic discharge (ESD) can be improved.

As can be seen from fig. 2, in the exemplary embodiment shown, the sensor carrier 10 has a through-opening 17, through which the interior of the sheath 7 can be filled at least partially with a damping medium. Thereby, the vibration characteristics of the sensor unit 1 can be influenced in an advantageous manner. Thus, for example, specific damping characteristics can be set.

Embodiments of the present invention provide a sensor unit for a vehicle, for which the circuit board can be reinforced by a support geometry on the sensor carrier or by a contact unit acting as a support unit in the housing, so that the circuit board with at least one vibration-sensitive sensor element can be protected against undesired vibrations and disturbances. In an advantageous manner, a rigid or hard and less susceptible to interference connection can be produced between the mechanical device and the electronic device by means of a short vibration chain from the sensor mount to the circuit board, which advantageously influences the eigenvibration behavior of the sensor unit. In order to further improve the vibration behavior of the sensor unit, the natural resonance can be set by means of the applied damping medium.

Claims

1. A sensor unit (1, 1A) for a vehicle, having a sensor carrier (10), which forms a mechanical interface (10A) for the sensor unit (1) and carries a circuit board (3), on which at least one vibration-sensitive sensor element (5A) is arranged, characterized in that the sensor carrier (10) has a fastening flange (12), on a first surface (13) of which, facing the circuit board (3), a first engagement geometry (14) is formed, which at least partially accommodates the circuit board (3) and is oriented at a predefined angle relative to the first surface (13), wherein a second engagement geometry (16) is formed on a second surface (15) of the fastening flange (12) opposite the first surface (13), the sensor carrier (10) can be connected to a mechanical system in a force-fitting and/or form-fitting manner by means of the second engagement geometry.

2. Sensor unit (1, 1A) according to claim 1, characterized in that the sensor mount (10) with the first and second engagement geometries (14, 16) is a rotationally symmetrical turned piece.

3. Sensor unit (1) according to claim 1 or 2, characterized in that the first engagement geometry (14) is a support geometry (14A) with a U-shaped receiving groove (14.1), the width of the receiving groove (14.1) matching the thickness of the circuit board (3).

4. Sensor unit (1, 1A) according to claim 3, characterized in that the first edge (3.1) of the circuit board (3) is held in the accommodation groove (14.1) in a force-fitting and/or material-fitting manner.

5. Sensor unit (1, 1A) according to any one of claims 1 to 4, characterized in that the second engagement geometry (16) is a self-biting geometry (16A) or a knurled geometry (16B) or an external thread and is receivable by a corresponding receiving geometry of the mechanical system.

6. Sensor unit (1, 1A) according to one of claims 1 to 5, characterized in that the contact unit (20) forms an external electrical interface (20A) with at least one external contact point (24) for the at least one vibration-sensitive sensor element (5A).

7. Sensor unit (1, 1A) according to claim 6, characterized in that the contact unit (20) has a third engagement geometry (26) which at least partially accommodates the circuit board (3).

8. Sensor unit (1A) according to one of claims 1 to 7, characterized in that a fourth engagement geometry (18) of a connection for force-fitting and/or material-connecting the jacket (7) is formed between the first surface (13) of the fastening flange (12) and the first engagement geometry (14).

9. Sensor unit (1A) according to claim 8, characterized in that the contact unit (20) forms a fifth engagement geometry (27) which is adapted to the inner contour of the sheath (7) such that the contact unit (20) is guided concentrically in the sheath (7).

10. Sensor unit (1A) according to claim 8 or 9, characterized in that the interior of the sheath (7) is at least partially filled with a damping medium through a through-hole (17) in the sensor mount (10).

11. Sensor unit (1, 1A) according to one of claims 1 to 10, characterized in that the at least one vibration-sensitive sensor element (5A) detects at least one acceleration in a predefined spatial direction and/or a rotational speed around a predefined spatial axis.