JP2022534368A - Sealing device for statically sealing components at risk of freezing - Google Patents

Abstract

The present invention is to statically move a disc-shaped sensory and/or optical component element (1; 1') that is at risk of freezing to a component housing (2; 2') that abuts it on the edge side. 1. A packing device for sealing, comprising at least one elastomeric packing element (3; 4; 4'; 4''; 4''') arranged therebetween for static housing sealing, The elastomeric packing element is electrically operable for deicing by thermal conduction from the elastomeric packing element (3; 4; 4'; 4''; 4''') to the component element (1; 1'). It relates to the packing device provided with means for heating to. In this case, said means for electrically heating said packing elements (3; 4; 4'; 4''; 4''') comprise an electrically conductive elastomer, said electrically conductive elastomers being spaced from each other and said It is energizable with electrical energy via at least two electrical contact sites (5; 5a; 5b) permanently attached to the packing element (3; 4; 4'; 4''; 4'''). [Selection diagram] Fig. 1

Description

SUMMARY OF THE INVENTION The present invention is a packing device for statically sealing disc-shaped sensory and/or optical component elements that are at risk of freezing against component housings that abut them on the rim side, the sealing device comprising: an elastomeric packing element disposed therebetween for static housing sealing, said elastomeric packing element for electrically heating to effect deicing by heat conduction from said elastomeric packing element to said component element; It relates to said packing device comprising means.

The field of application of the invention mainly extends to automotive technology. For example, camera systems and sensors in automobiles may need to be de-iced to keep them ice-free during operation in order to be cold responsive. Furthermore, it is necessary to prevent the effects of moisture. For this reason, a heat source is usually mounted near the frontmost optical lens in camera systems. Other sensors, such as, for example, ultrasonic sensors or radar sensors, also have, as an external component element, a disk-shaped cover that is transparent to the sensor signal and is mostly made of plastic. De-icing also requires a heat source in the vicinity of this cover. In this way, ice and snow layers can be melted during a cold start of the vehicle, and the cover can be kept ice and snow free while driving, thereby providing an alternative wiper system or injection system. becomes unnecessary. In addition, the sealing device according to the invention can also be used outside of automotive technology, ie with likewise configured component parts that are at risk of freezing, for example component parts in building technology or household appliance technology.

DE 10 2005 020 003 A1 describes, inter alia, contact surface heating means for heating elements, in particular for window panes, outer mirrors etc. A heating element is disclosed for use as a

The heating element includes at least one thermoelectric heating element, which is formed from thermoplastic conductive plastic and is capable of supplying electrical energy via at least two conductive paths. In this case, the conductor track is applied by means of a thermal spraying method, in particular by means of standardized plasma spraying. The conductor tracks mounted in this way are each conductively connected with an electrical connection site, in particular with at least one contact pin.

For mounting on the rear side of the outer mirror, the known heating element can be correspondingly plate-shaped and preferably consists of sintered spheres or granules of the thermoplastic conductive plastic used here. .

This type of panel heating requires correspondingly additional construction space and is therefore suitable for disc-shaped sensory or optical component elements of the type in question here as they block the light path. not

Furthermore, the known state of the art also reveals packing devices for statically sealing parts that are at risk of freezing. The packing system comprises electrical heating means for deicing by conduction of heat from the packing element to said member. For this, a heating wire or the like is conventionally associated with the packing element.

International Publication No. 2013/092964A2 pamphlet

It is an object of the present invention to provide a disk-shaped sensory and/or optical component element at risk of freezing, which is simple to produce in terms of production technology and which has reliably acting means for electrically heating the packing element. To provide a packing device for static sealing.

This task is solved starting from the sealing device according to the preamble of claim 1 in conjunction with the characterizing features of claim 1 . The following dependent claims represent advantageous further developments of the invention.

The present invention provides that the means for electrically heating the packing element includes an electrically conductive elastomer that is energized with electrical energy through at least two spaced apart permanent electrical contacts on the packing element. It contains technical teachings that it is possible.

In other words, this allows the elastomeric packing element itself to be utilized as a heat source. This has the advantage that the existing elastomer pressing force of the packing element against the component element to be deiced can be utilized for efficient heat transfer. Furthermore, no separate components requiring installation space are required for the additional heating means. The invention takes advantage of the constructional circumstance that the packing element for statically sealing the housing is in most cases the last surface-contacting part to the sensory and/or optical component element. Experiments have shown that electrical biasing of the conductive elastomer to produce a current along its cross-section produces sufficient heating of the packing elements and the resulting thermal energy is sufficient for deicing. , can be conducted to component elements that abut it on the edge side. The heating means according to the invention then do not interfere with the light path through the disc-shaped sensory or optical component element.

The use of an elastomer for the specific purposes of the present invention also has the advantage that it is crosslinked so that the conductive filler contained therein is fixed immovably within the crosslinked structure. . In addition, elastomeric materials can react flexibly during thermal expansion, which improves their conformability to the component elements to be heated and improves heat transfer. Furthermore, of course, the sealing action is improved at the same time. Also, the elastomeric material of the packing is typically not subject to aging by repeated expansion over its lifetime. This is because such expansion is within the expansion range which is not problematic for elastomers. In contrast, the thermoplastics commonly used in the state of the art for similar purposes have a comparatively low elongation at break, and numerous thermal expansion processes lead to undesired aging up to thermodynamic failure. may have been exposed to

According to a first embodiment, the sealing element can be designed as an insert which is arranged in a circumferential groove formed on the side of the component housing or on the edge of the component element. Such circumferential grooves, which can extend radially or axially, allow a prefabricated packing element to be easily inserted and brought into electrical contact. Additional positioning means, such as cover crowns, are usually required as fixing means.

Alternatively, according to a second embodiment, it is also conceivable for the sealing element to be formed as an injection-molded part or the like and molded directly onto the edge side of the component element or on the side of the component housing. For this purpose, the component housing or the component elements can be complementarily provided with retaining grooves to enhance the stability of the connection. Additionally, injection molding has the advantage that a reliable electrical contact can be made at the electrical contact sites of the packing element. Besides injection molding, other suitable molding methods can also be used, such as 3D printing of different material components.

During molding of the packing element, the area of the contact site of the packing element may be provided with an adhesion promoter to increase electrical conductivity at the bond site. Such adhesion promoters known per se can be applied to the contact pins before the production of the packing element or alternatively can be incorporated into the elastomeric material. If a separate adhesion promoter is not used, sufficient engagement of the contact pins within the elastomeric material should be ensured through the residual pressure of the molding pressure of the elastomeric material upon pressing.

In particular, the disc-shaped sensory or optical component element forms a circular shape, so that in this case the elastomeric packing element fitted thereon is formed in the form of a closed ring. In this case, the sealing element preferably has two contact sites which are arranged exactly opposite each other and which are connected to each other by two current paths of the same length. Insofar as current paths of the same length are formed by two mirror-symmetric half-circuits of the ring-shaped packing element, they simply allow uniform heating of the packing element along the entire circumference. Besides this, it is also conceivable for the sealing element to have another, preferably closed, geometry, which is usually pregiven by the edge contour of the disc-shaped part element to be sealed.

According to a further refinement of the invention, it is proposed that the contact sites are realized respectively by piercing or digging a metal contact pin into the electrically conductive elastomeric material of the packing element. The fit is advantageously further enhanced after contact by thermal expansion of the elastomeric material.

For the purposes according to the invention, preferably elastomeric substrates which are members of the group of elastomeric materials comprising natural rubbers, thermoplastic elastomers, ethylene propylene diene monomer rubbers (EPDM), silicones, fluororubbers is used for manufacturing the packing elements.

The filling material of the packing element, which makes such an elastomeric substrate electrically conductive, is preferably selected from the group of electrically conductive materials including metal particles, carbon black, graphite, carbon fibres, carbonanotubes. It is

Various experiments have shown that in order to achieve the deicing action according to the invention in the application targeted by the invention, while achieving this without having to consume a great deal of electrical energy, the filling in the packing element It has been found that the wood content should be in the range between 10 and 70% by volume. Particularly preferred, a range between 30 and 50% by volume has been found to be particularly effective in achieving the aforementioned optimum objectives. The mixture component allows the specific electrical resistance of the packing element to be adjusted according to the prevailing structural boundary conditions, as well as for sealing automatic mitigation control in the sense of the so-called PTC effect (PTC=Positive Temperature Coefficient). A suitable height for the coefficient of thermal expansion of the elastomeric substrate can be utilized.

In the sense of an advantageous application of the solution according to the invention, the disk-shaped component element is optically non-optical as an optical lens for camera systems or the like, as headlight glass for vehicle lighting or for ultrasonic or radar sensors. It is proposed to be constructed as a transparent cover disk. Besides this, other component elements, preferably disk-shaped, which provide a housing seal on the edge side and which are at risk of freezing at the mounting location, can also be equipped with the solution according to the invention.

In the case of headlights, besides the deicing function, fogging of the glass can also be prevented. This was conventionally achieved by the waste heat of the lighting means used. Due to the increasing use of LED lamps as lighting means, less heat is dissipated in the headlights and fogging of the headlights is not reliably prevented. Therefore, the solution according to the invention also provides a remedy for this.

In the following, further measures improving the invention are shown in more detail with the help of figures together with the description of advantageous embodiments of the invention.

1 is a partial longitudinal sectional view of an optical lens device of a camera system equipped with a packing device of the present invention according to a first embodiment; FIG. FIG. 5 is a partial vertical cross-sectional view of an optical lens device of a camera system provided with a packing device of the present invention according to a second embodiment; FIG. 11 is a partial vertical cross-sectional view of an optical lens device of a camera system equipped with a packing device of the present invention according to a third embodiment; Fig. 4 is a schematic longitudinal section through another camera system with a cover crown and a packing device according to the invention in a first embodiment; Figure 5 is a schematic longitudinal section view of a detail of the camera system of Figure 4 with a packing device according to another embodiment; 1 is a schematic vertical cross-sectional view for explaining electrical contact in a packing device of the present invention according to a first embodiment; FIG. 1 is a schematic vertical cross-sectional view for explaining electrical contact in a packing device of the present invention according to a first embodiment; FIG. FIG. 5 is a schematic vertical cross-sectional view for explaining electrical contacts in the packing device of the present invention according to a second embodiment; FIG. 5 is a schematic vertical cross-sectional view for explaining electrical contacts in the packing device of the present invention according to a second embodiment; FIG. 4 is a schematic vertical cross-sectional view for explaining electrical contacts in detail;

According to FIG. 1, a disc-shaped optical component element 1 is used in the form of a front lens in a camera system (not shown in detail hereinafter) of a motor vehicle, which, together with various other optical lenses, is housed in a component housing. 2 is inserted into a tubular lens holder. The outer surface of the optical component element 1 is exposed to fog and ice due to corresponding environmental influences at the point of use in the motor vehicle. The optical component element 1 is statically sealed to the component housing 2 via a radial ring-shaped elastomeric sealing element 3 and an axial ring-shaped elastomeric sealing element 4 .

Here, in the context of this packing device, the axial ring-shaped elastomeric packing element 4 consists of an electrically conductive elastomer, which has two electrical contacts arranged opposite each other and permanently attached to the packing element 4 . Via points 5 (only one of which is shown here), it can be activated with electrical energy, as a result of which the sealing element 4 heats up and thereby presses against the disk-shaped component element 1. The heat is transferred to this to exert the desired deicing action. The electrical contact points 5 are then realized by piercing and cutting of metal contact pins 6 into the elastomeric material of the electrically conductive packing element 4 . Here the packing element 4 is formed as an insert which is arranged in a circumferential groove 7 formed between the component housing 2 and the adjacent lens. Due to the here rather large contact surface of the packing element 4 against the component element 1 to be heated, there is excellent heat conduction.

However, according to FIG. 2, it is also possible to equip only one radially arranged ring-shaped elastomeric packing element 3 with the means according to the invention for electrically heating, whereby the radially outward heat conduction into the component element 1 from the edge region of the .

According to the combination variant illustrated in FIG. 3 , the radially arranged ring-shaped elastomeric packing element 3 is also axially arranged such that it lies between the component element 1 and the component housing 2 . The packing elements 4 also consist of an electrically conductive elastomer according to the invention, these ring-shaped packing elements being here via a common metal contact pin 6' for the realization of the contact sites 5 (typically ) can be electrically energized. Here, the metal contact pins 6 are realized here by means of multiply-bent metal sheets, which are not inserted into the elastomeric sealing elements 3 and 4, but rather attached to them on the respective sealing underside. abut. Compared to the two previously described embodiments, this packing device can provide maximum heat input to the component element 1 to be heated.

In the embodiment of the camera system illustrated in FIG. 4, the camera system consists essentially of a camera housing 7 with a sleeve-like component housing 2' inserted therein, at the distal end of the sleeve-like component housing: A component element 1' formed as an optical lens is arranged. The component element 1' is detachably fixed to the component housing 2' by means of a cover crown 8 by means of a screw connection. In this case, the disc-shaped component element 1' is fitted on its edge side to an axially arranged elastomeric sealing element 4', which consists of the electrically conductive elastomer according to the invention. Heat conduction also takes place at this location. At the proximal end side of the sleeve-like component housing 2', an optical sensor 9 of the camera system is arranged at the end of the optical path formed by the component housing 2'. A current supply 10 is again used to electrically energize the electrically conductive packing element 4', for this purpose two metal contact pins 6a arranged exactly opposite each other on the packing element 4'. and 6b are provided. In this way two current paths of equal length are produced, each starting on either side of the contact pins 6a and 6b and ensuring uniform heating of the packing element 4'.

In a variant embodiment of the previously described camera system, illustrated in FIG. 5, the electrically conductive elastomeric packing element 4' formed in accordance with the invention is formed as a form-constrained multiple packing, which in the axial direction is divided into part elements. It seals against 1' and radially against a cover crown 8 screwed onto the component housing 2'. This ring-shaped elastomeric sealing element 4 ″ is then provided with a wider contact surface in the axial direction than in the previous embodiment in order to improve the heat transfer to the component element 1 ′.

The sequence diagrams of FIGS. 6A and 6B illustrate the first mechanical and electrical coupling of the first and second contact sites 5a and 5b for the elastomeric packing element 4''', including the component housing 2'. It describes the possibilities. In doing so, in a first step, according to FIG. 6A, first metal contact pins 6 respectively provided for each electrical contact site 5a and 5b are (typically) injected into the housing part 2' by injection moulding. is inserted into a mold and injection coated before molding. Then, according to FIG. 6B, an electrically conductive elastomeric material is injected into the cut-out of the component housing 2' which is open for this purpose, in order to form the electrically conductive packing element 4'''. The retention of the elastomeric material on the end side of the metal contact pin 6 is improved by inserting an adhesion promoter. Thus, basically starting from the injection site 11, the metal contact pin 6 is oversprayed with a conductive elastomeric material.

In contrast, the sequence diagrams of FIGS. 7A and 7B show a second possibility of electrically and mechanically coupling the contact pin 6 (typically) to both contact sites 5a and 5b. This is done by so-called stitching both metal contact pins 6 into (typically) already preformed ring-shaped elastomeric packing elements 4'''. In this case, in a first step, according to FIG. Injection to form a packing element 4'''. Then, according to FIG. 7B, both metal contact pins 6, which are embedded in the component housing 2' and/or in the packing element 4''', are (typically) stitched into the elastomer material. According to the detailed view shown in FIG. 8, the engagement of the metal contact pin 6 in the component housing 2' takes place via a barb 13a integrally formed on the metal contact pin 6 in this area, to which In contrast, the bite-in at the sealing element 4''' likewise takes place via another barb 13b which is arranged on the distal end side of the metal contact pin 6. FIG.

The invention is not limited to the embodiments described above. Rather, variants thereof are conceivable as covered by the scope of protection of the following claims. For example, the use of the sealing device according to the invention also for other component elements at risk of freezing, for example for optically non-transparent cover disks such as headlight glass, ultrasonic sensors or radar sensors. It is also possible to use

1, 1' component element 2, 2' component housing 3, 4, 4', 4'', 4''' packing element 5, 5a, 5b electrical contact location 6 metal contact pin 7 circumferential groove

Claims (12)

for statically sealing a disc-shaped sensory and/or optical component element (1; 1') that is at risk of freezing against the component housing (2; 2') that abuts it on the edge side A packing device comprising at least one elastomeric packing element (3; 4; 4';4'';4''') arranged therebetween for static housing sealing, said elastomeric packing element is electrically heated for deicing by heat conduction from said elastomeric packing elements (3; 4; 4';4'';4''') to said component elements (1; 1') In said packing device comprising means of
Said means for electrically heating said packing elements (3; 4; 4';4'';4''') comprise a conductive elastomer, said conductive elastomers being spaced from each other said packing elements ( 3; 4; 4′; 4″; 4′″) can be activated with electrical energy via at least two electrical contact sites (5; packing device. The electrically conductive elastomer of the packing element (3; 4; 4'; 4''; 4''') increases in volume by heat on application of electrical energy, i.e. the part housing (2; 2') and a significant increase in the pressing force at the component elements (1; 1') increases the volume so that the sealing action increases. said packing element (3; 4; 4'; 4''; 4''') in a circumferential groove (7) formed on the side of said component housing (2) or on the side of said component element (1); 2. The sealing device according to claim 1, characterized in that it is formed as an arranged insert. Said packing element (3; 4; 4'; 4''; 4''') is formed as an injection-moulded part and is integral with the edge side of said part element (1') or on the side of said part housing (2'). 2. The packing device of claim 1, wherein the packing device is molded. 2. Packing device according to claim 1, characterized in that the elastomeric packing element (3; 4; 4'; 4''; 4''') is formed in the form of a closed ring. Said packing element (3; 4; 4'; 4''; 4''') has two contact sites (5) which are arranged exactly opposite each other, which contact sites are 6. A packing device according to claim 5, characterized in that they are connected to each other by two current paths of equal length. Said contact site (5) is realized by piercing or wedging a metallic contact pin (6) into said elastomeric material of said packing element (3; 4; 4'; 4''; 4'''). 2. The packing device according to claim 1, characterized in that it is . 4''; 4'''), characterized in that the area of the contact site (5) of the packing element (3; 4; 4'; 4''') is provided with an adhesion promoter to increase the electrical conductivity. A packing device according to claim 1 or 4. said packing element (3; 4; 4'; 4'' from the group of elastomeric materials comprising natural rubber, thermoplastic elastomers, ethylene propylene diene monomer rubber (EPDM), silicones, fluororubbers; 4''') elastomeric substrate is selected. said elastomeric group of said packing element (3; 4; 4'; 4''; 4''') from the group of conductive materials comprising metal particles, carbon black, graphite, carbon fibres, carbon nanotubes; 10. A packing device according to claim 9, characterized in that the filler material is selected to render the material electrically conductive. 4''; 4''') in a range between 10 and 70% by volume, preferably between 30 and 50% by volume. 11. A packing device according to claims 9 and 10, characterized in that it is in the range. The disk-shaped component (1; 1') is designed as an optical lens, as a headlight glass or as an optically non-transparent cover disk for an ultrasonic or radar sensor. The packing device according to any one of claims 1 to 11.

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