DE102018113448A1 - Housing for a sensor - Google Patents

Abstract

Housing (1) for a sensor (2), in particular for installation in a motor vehicle (3), comprising a wall (4) which at least partially at least partially consists of an electrically conductive polymer material (5).

Description

The invention relates to a housing for a sensor, in particular for installation in a motor vehicle, a sensor, in particular for monitoring an environment of a motor vehicle, and a motor vehicle.

It is known to protect functional elements of sensors in that they are arranged in a housing. Depending on the field of application of the sensor, in particular in applications with low ambient temperatures, it may also be necessary to heat the housing. In this context, heating films have been proposed, which are attached to a housing wall. However, it has been found that corresponding heating foils are susceptible to overheating problems. In addition, the heating foils are expensive in their production.

On this basis, it is an object of the present invention, at least partially solve the problems described with reference to the prior art. In particular, a housing for a sensor and a sensor are to be specified, which each contribute at least to enable safe operation of the sensor even at low ambient temperatures. In addition, the housing and the sensor should in particular be inexpensive to produce.

These objects are achieved by the features of the independent claims. Further advantageous embodiments of the solution proposed here are specified in the dependent claims. It should be noted that the features listed individually in the dependent protection claims can be combined with each other in any technologically meaningful manner and define further embodiments of the invention. In addition, the features specified in the claims in the description are specified and explained in more detail, wherein further preferred embodiments of the invention are shown.

Here proposed is a housing for a sensor, in particular for installation in a motor vehicle, having a wall which at least partially at least partially consists of an electrically conductive polymer material.

The housing may be adapted to at least (fully) receive and / or at least largely surround functional elements of the sensor, such as a camera optics, or even the entire sensor. In addition, the housing may be formed in the manner of a cover for a sensor. In other words, this means in particular that the housing does not have to completely cover the sensor, in particular not from all directions.

The housing is provided and set up in particular for installation in or attachment to a motor vehicle. The housing may also be adapted to be mounted inboard or outboard of a windshield of a vehicle. Preferably, in this context, the housing is adapted to hold the sensor in a predefined orientation relative to the windshield. The housing is provided and arranged in particular for installation in the region of a bumper and / or grille. In principle, the housing can be used in any area of the bodywork of a vehicle.

At least a portion of the wall of the housing is at least partially made of an electrically conductive polymer material (or plastic material). Preferably, at least a portion of the wall of the housing is (only) partially or at least partially, but not completely made of an electrically conductive polymer material.

The electrically conductive polymer material may be, for example, an intrinsically conductive polymer (or an intrinsically conductive plastic). In other words, this means in particular that the electrically conductive polymer material is one that is itself electrically conductive. Alternatively or cumulatively, it can be provided that the electrically conductive polymer material is electrically conductive by at least one electrically conductive additive or filler, such as aluminum flakes or carbon black, which is contained or embedded in a (not necessarily self-conductive) polymer.

Examples of intrinsically conductive polymers or plastics which can be used here are poly-3,4-ethylenedioxythiophene (PEDOT, also PEDT), polystyrene sulfonate (PSS), doped polyethyne (also polyacetylene, PAC) and polyaniline (PAni). A preferred (intrinsic) conductive polymer is polyethylene.

As electrically conductive additive or filler can serve in particular electrically conductive fibers. In other words, this means in particular that the electrically conductive polymer material has electrically conductive fibers embedded in a polymer matrix.

In addition, electrically conductive wires (eg, metal wires, particularly copper wires) may be embedded in the polymeric material to form the electrically conductive polymeric material. For example, appropriate wires on a Cloth fabric sewn and be overmolded with polymer material (to form a polymer matrix). In other words, this means in particular that the electrically conductive polymer material has electrically conductive wires embedded in a polymer matrix. The wires can in this case form, for example, the contact arms explained in greater detail below.

As examples of usable here, not intrinsically conductive, but with conductive additives or fillers and / or wires ausstattbare polymers or plastics may be about acrylonitrile-butadiene-styrene copolymers, polycarbonates, PA66 (polyamide-66 or polymer of hexamethylenediamine and Adipic acid) polybutylene terephthalate and polyoxymethylene.

Alternatively or cumulatively to the embedding of conductive additives or fillers and / or wires described herein into a matrix, it may be provided that these additives or fillers and / or wires are applied to the matrix or a polymer substrate (or plastic substrate) , in particular vapor-deposited and / or printed. In addition, it can be provided that the conductive additives or fillers and / or wires are introduced into the matrix in a 3D printing process and / or applied to the matrix (or the substrate). The term "wires" should in particular represent metallic conductor structures.

According to an advantageous embodiment, it is proposed that the electrically conductive polymer material fills at least 44% of a wall cross section of the wall of the housing in at least one surface area.

The electrically conductive polymer material preferably fills at least 50% of the wall cross section or even at least 54% of the wall cross section. In addition, it can be provided that at least 5% or even at least 10% of the wall cross-section is filled with a gas, such as air, in the at least one surface area. The gas can contribute in an advantageous manner to thermally insulate or insulate the housing.

According to a further advantageous embodiment, it is proposed that the electrically conductive polymer material fills in at least one surface area at least 80%, preferably at least 90% or even at least 99% of a wall cross section of the wall of the housing. A wall cross section which consists almost entirely of electrically conductive polymer material can advantageously allow a reduced space requirement, a cost and / or a weight saving. In the determination of the wall cross-section is (usually) placed on the supporting structure of the wall. Any thermal insulation or electrical insulation, which are formed on the surface of a wall, are preferably not taken into account in the determination of the wall cross-section. However, it is possible to take such insulation (or coatings) into account when determining the wall thickness.

According to an advantageous embodiment, it is proposed that an electrically insulating protective layer is formed on at least one surface of the wall. In other words, this means, in particular, that electrical insulation is formed on at least one surface of the wall.

The insulating protective layer can be formed, for example, with a non-electrically conductive polymer. The electrically insulating protective layer is in particular formed on or on an inner (inwardly facing) surface of the wall. The electrically insulating protective layer or electrical insulation contributes in particular to protecting (electronic) functional elements of the sensor from an undesired voltage flashover from the electrically conductive polymer material to the functional elements.

According to an advantageous embodiment, it is proposed that a thermal insulation is formed on at least one surface of the wall.

For this purpose, a thermal insulating material can be arranged or applied to or on a surface of the wall. The insulating material may be, for example, a (non-electrically conductive) polymer with a low thermal conductivity. The thermal insulation is formed in particular on an outer (outwardly facing) surface of the wall. The thermal insulation can contribute in particular to protect functional elements of the sensor from low ambient temperatures.

According to an advantageous embodiment, it is proposed that the electrically conductive polymer material is a material with PTC resistance properties (PTC = positive temperature coefficient).

If the resistance of a material increases with increasing temperature, it has a positive temperature coefficient. Materials with metal-like conductive properties basically have a positive temperature coefficient (PTC properties or PTC resistance properties) with regard to their electrical resistance. In the case of metal-like conductive properties, the resistance increases almost linearly with increasing temperature. In contrast, have electrically conductive polymer materials usually in a very narrow temperature band, a strong resistance increase. Generally, these polymeric materials are also abbreviated PPTC. Here, the PPTC stands for the English term Polymer Positive Temperature Coefficients.

In other words, the electrically conductive polymer material with PTC resistance properties can also be described in particular as a so-called (polymer) PTC thermistor. A thermistor, PTC resistor or PTC thermistor is a temperature-dependent resistor, which counts in particular to the group of thermistors. It has a positive temperature coefficient as a property and conducts the electric current better at low temperatures than at high temperatures.

According to an advantageous embodiment, it is proposed that the electrically conductive polymer material is electrically contacted at least on an outer surface of the housing with at least one electrical contact.

In addition, the electrically conductive polymer material may be electrically contacted on the outer surface of the housing with at least one further electrical contact. Alternatively or cumulatively, the electrically conductive polymer material may be electrically contacted on an inner surface of the housing with at least one further electrical contact. The electrically conductive polymer material is in particular arranged between the electrical contact and the further electrical contact such that a short circuit between these contacts can be avoided. In other words, this means in particular that the electrically conductive polymer material electrically connects the electrical contact and the further electrical contact. For this purpose, the electrically conductive polymer material regularly extends from the electrical contact to the further electrical contact.

According to an advantageous embodiment, it is proposed that at least two (first) electrical contacts (contact and further contact) exist in the wall, which form a multiplicity of contact arms which are opposite one another at a distance from each other. In this case, it may be provided in an advantageous manner that the (first) distance of the opposing (first) contact arms from each other (locally) deviates by a maximum of 10% from a mean distance.

Between the contact arms, the electrically conductive polymer material is arranged regularly. Mutually (directly) opposite contact arms overlap in particular (only) partially. In other words, this means in particular that a contact arm of a contact and a contact arm of another contact (in particular only partially) are arranged overlapping and spaced from each other. The embodiment described with contact arms in particular allows the advantage that the electrically conductive polymer material can be heated as uniformly as possible (by electrical resistance heating). The two electrical contacts relate in particular to the same heating circuit or form (exactly) a heating circuit.

It is particularly advantageous if the distance of the (mutually directly) opposite contact arms from each other (locally) deviates by a maximum of 10% from a mean distance. This is especially advantageous if the most uniform possible heating is to be achieved. Alternatively or cumulatively, however, it can also be provided that the spacing of (directly) opposite contact arms (of the same heating circuit) from each other locally (deliberately) deviates by more than 10% from a mean distance. This is particularly advantageous in particular if specific subregions are to be set in which a faster heating is to be achieved than in other subregions.

In particular, for setting subsections which can be heated at different rates, it may moreover be provided that at least two second electrical contacts (contact and further contact) exist in the wall, forming a multiplicity of second contact arms which are opposite one another at a distance, the second distance the opposite second contact arms to each other from the first distance of the opposite first contact arms to each other. In this context, it may in particular be provided that the first contacts form a first heating circuit and the second contacts form a second heating circuit.

According to an advantageous embodiment, it is proposed that at least one inner surface of the housing has a corrugated surface structure. Alternatively or cumulatively, it can be provided that an outer surface of the housing has a corrugated surface structure.

According to an advantageous embodiment, it is proposed that the housing widens, at least in sections, from a first opening to a second opening with a cone. In other words, this means in particular that the housing widens, at least in sections, from a first opening to a second opening in the form of a cone.

According to an advantageous embodiment, it is proposed that the housing has connecting elements with which the housing can be connected to further housing sections. The connecting elements are in particular adapted to be able to provide a positive and / or non-positive connection.

According to a further aspect, a sensor is proposed, in particular for monitoring an environment of a motor vehicle, comprising a housing proposed here.

The sensor is preferably an optical sensor. Particularly preferably, the sensor is a camera sensor. In other words, this means in particular that the sensor comprises a camera optics, which is arranged in particular in the housing.

According to a further aspect, a motor vehicle is proposed, comprising a housing proposed here and / or a sensor proposed here. In addition, the motor vehicle usually has a windshield. Advantageously, the housing and / or the sensor is mounted on the inside or outside of the windshield of the vehicle.

The discussed in connection with the housing details, features and advantageous embodiments may also occur in accordance with the presented here sensor and / or the motor vehicle and vice versa. In that regard, reference is made in full to the statements there for a more detailed characterization of the features.

• 1: ein hier vorgeschlagenes Gehäuse für einen hier vorgeschlagenen Sensor in einer Schnittdarstellung,
• 2: einen beispielhaften Wandquerschnitt eines hier vorgeschlagenen Gehäuses,
• 3: einen weiteren beispielhaften Wandquerschnitt eines hier vorgeschlagenen Gehäuses, und
• 4: ein hier vorgeschlagenes Gehäuse in einer Draufsicht.

The solution presented here and its technical environment are explained in more detail below with reference to the figures. It should be noted that the invention should not be limited by the embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and / or findings from other figures and / or the present description. They show schematically:

• 1 a housing proposed here for a sensor proposed here in a sectional view,
• 2 : an exemplary wall cross-section of a housing proposed here,
• 3 a further exemplary wall cross section of a proposed housing, and
• 4 : a proposed here housing in a plan view.

1 schematically shows a proposed here housing 1 for a sensor proposed here 2 in a sectional view. The sensor 2 serves here as an example for monitoring an environment of a motor vehicle 3 and has the housing 1 on.

The housing 1 has a wall 4 on. The wall 4 consists at least in sections and at least partially of an electrically conductive polymer material 5 ,

The electrically conductive polymer material 5 Here is an example of a material with PTC resistance properties. PTC stands for the English term "positive temperature coefficient".

In 1 is also exemplified that the housing 1 at least in sections from a first opening 15 to a second opening 16 with a cone 17 extended. In addition, in 1 exemplifies that the housing 1 fasteners 18 having, with which the housing 1 to other housing sections 19 can be connected.

2 schematically shows an exemplary wall cross-section 7 a proposed here housing 1 (not shown here, cf. 1 ). The reference numerals are used uniformly, so that to the above statements to 1 Reference can be made.

In 2 exemplifies that the electrically conductive polymer material 5 in at least one surface area 6 (not shown here, cf. 1 ) at least 44% of a wall cross-section 7 the Wall 4 of the housing 1 fills. The wall cross-section is here by two surfaces 8th the Wall 4 limited. In this embodiment, the thickness of an electrical insulation 9 or the thickness of a thermal insulation 10 not counted.

Moreover, in 2 shown by way of example that on at least one (here the right) surface 8th the Wall 4 an electrically insulating protective layer 9 or an electrical insulation 9 is trained. In addition, here is an example of at least one (here the left) surface 8th the Wall 4 a thermal insulation 10 educated.

Further illustrated 2 by way of example, that the electrically conductive polymer material 5 at least on an outer surface 8th of the housing 1 with at least one electrical contact 11 electrically contacted.

3 schematically shows another exemplary wall cross-section 7 a proposed here housing (not shown here, see. 1 ). The reference numerals are used uniformly, so that the above statements on the 1 and 2 Reference can be made. When determining the wall cross-section 7 In this embodiment, the thickness of an electrical insulation 9 or the thickness of a thermal insulation 10 (not shown here) counted. Both variants the thickness of an electrical insulation 9 and / or the thickness of a thermal insulation 10 in the determination of the wall cross section 7 to be considered with possible.

In 3 exemplifies that at least one inner surface 8th of the housing 1 a wavy surface texture 14 having. The inner surface 8th is as shown 3 the right surface 8th ,

4 schematically shows a proposed here housing 1 in a top view. The reference numerals are used uniformly, so that the above statements on the 1 to 3 Reference can be made.

In 4 exemplifies that in the wall 4 at least two electrical contacts 12 exist that are a variety of yourself at a distance 13 opposite contact arms 12 train, with the distance 13 the opposite contact arms 12 deviates locally by a maximum of 10% from a mean distance.

Here proposed are a housing for a sensor and a sensor, which at least partially solve the problems described with reference to the prior art. In particular, a housing for a sensor and a sensor are specified, which each contribute at least to enable safe operation of the sensor even at low ambient temperatures. In addition, the housing and the sensor can be produced in particular at low cost.

LIST OF REFERENCE NUMBERS

1

casing

2

sensor

3

motor vehicle

4

wall

5

polymer material

6

area

7

Wall section

8th

surface

9

electrical insulation

10

thermal insulation

11

electric contact

12

contact arms

13

distance

14

surface structure

15

first opening

16

second opening

17

cone

18

connecting element

19

housing section

Claims (11)

Housing (1) for a sensor (2), in particular for installation in a motor vehicle (3), comprising a wall (4) which at least partially consists at least partially of an electrically conductive polymer material (5). Housing (1) to Claim 1 , wherein the electrically conductive polymer material (5) in at least one surface area (6) fills at least 44% of a wall cross-section (7) of the wall (4) of the housing (1). Housing (1) according to one of the preceding claims, wherein on at least one surface (8) of the wall (4) an electrically insulating protective layer (9) is formed. Housing (1) according to one of the preceding claims, wherein on at least one surface (8) of the wall (4), a thermal insulation (10) is formed. A housing (1) according to any one of the preceding claims, wherein the electrically conductive polymer material (5) is a material having PTC resistance properties. Housing (1) according to one of the preceding claims, wherein the electrically conductive polymer material (5) at least on an outer surface (8) of the housing (1) is electrically contacted with at least one electrical contact (11). Housing (1) according to one of the preceding claims, wherein in the wall (4) at least two electrical contacts (12) exist, which form a plurality of at a distance (13) opposite contact arms (12). Housing (1) according to one of the preceding claims, wherein at least one inner surface (8) of the housing (1) has a corrugated surface structure (14). Housing (1) according to one of the preceding claims, wherein the housing (1) has connecting elements (18) with which the housing (1) can be connected to further housing sections (19). Sensor (2), in particular for monitoring an environment of a motor vehicle (3), comprising a housing (1) according to one of the preceding claims. Motor vehicle (3), comprising at least one housing (1) according to one of Claims 1 to 9 or a sensor (2) after Claim 10 ,

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