阅读说明：本技术 防水的电开关组件 (Waterproof electrical switch assembly ) 是由 J·A·西蒙尼斯帕冯 J·费尔南德斯雷纳 A·罗哈斯奎瓦斯 F·E·纳瓦罗佩雷斯 于 2020-04-15 设计创作，主要内容包括：一种防水的电开关组件,包括封闭隔间和容纳在所述封闭隔间内的电开关(10),从所述隔间引出的电缆(16)与所述电开关(10)连接,所述隔间被布置在壳体(11)内,所述壳体具有带有两个开口(11a、11b)的腔体,第一开口(11a)由被附接到所述壳体(11)的能压缩的弹性本体(12)密闭地密封,第二开口(11b)由盖(13)密闭地密封。所述弹性本体(12)延伸到所述壳体(11)的腔体中,提供支撑所述电开关(10)的表面(12b),所述盖(13)在其内表面上具有管状壁(18),所述管状壁被插入到所述壳体(11)的腔体中,并沿着周界与所述弹性本体接触,所述管状壁(18)完全地围绕所述开关并确保其防水性。(A watertight electric switch assembly comprising a closed compartment and an electric switch (10) accommodated in the closed compartment, an electric cable (16) leading from the compartment being connected with the electric switch (10), the compartment being arranged in a housing (11) having a cavity with two openings (11a, 11b), a first opening (11a) being hermetically sealed by a compressible, elastic body (12) attached to the housing (11), a second opening (11b) being hermetically sealed by a cover (13). The elastic body (12) extends into the cavity of the housing (11), providing a surface (12b) supporting the electric switch (10), the cover (13) having on its inner surface a tubular wall (18) inserted into the cavity of the housing (11) and in contact with the elastic body along the perimeter, the tubular wall (18) completely surrounding the switch and ensuring its waterproofness.)

1. A waterproof electrical push button switch assembly (10) comprising:

-closing the compartment; and

-a printed circuit board (14) supporting electronic switching components, a button (30) being housed within the closed compartment, a cable (16) leading from the compartment being connected to the printed circuit board (14), wherein the closed compartment is defined within a housing (11) comprising a cavity with two openings (11a, 11b), a first opening (11a) being hermetically sealed by a compressible elastomeric body (12), the compressible elastomeric body (12) having a portion (12a) arranged facing the button (30) of the electronic switching components (10), the compressible elastomeric body (12) being attached to the housing (11), a second opening (11b) being hermetically sealed by a cover (13),

it is characterized in that the preparation method is characterized in that,

-the two openings (11a, 11b) are arranged opposite each other,

-the compressible, elastic body (12) extends partially into the cavity of the housing (11), providing an inner portion with an annular flange (12b) which is placed against the inner surface of the housing adjacent to the first opening (11a) of the housing (11);

-the printed circuit board (14) carrying the electronic switching components is mounted in a recessed portion of the compressible elastomeric body (12); and is

-the cover (13) comprises, on its inner surface, at least one tubular wall (18) inserted into the cavity of the casing (11) and whose free edge establishes a perimetral interference contact with the surface of the elastic body, the tubular wall (18) of the cover (13) completely surrounding the electronic switching component and ensuring its waterproofness,

wherein the two insulated electrical conductors (16) are led out through side windows (17) of the housing (11) which are occupied by extensions (12c) of the elastic body (12) and through which the insulated electrical conductors (16) pass.

2. The electrical switch assembly according to claim 1, characterized in that said elastic body (12) further comprises a tubular wall (20) extending towards the outside of the cavity of said casing (11) until a perimetric interference contact is established with the inner surface of said closing cover (13) of said second opening (11b), said tubular wall (20) also surrounding said switch.

3. An electrical switch assembly according to claim 2, wherein the tubular walls (18, 20) of the resilient body (12) and the cover (13) have different widths and are mounted together.

4. An electrical switch assembly according to claim 1, wherein the switch comprises a printed circuit board (14) supporting electronic switch components, to which printed circuit board the ends of two insulated electrical conductors (16) are connected by soldering, the insulated electrical conductors extending through the resilient body (12) to the outside of the housing (11), the printed circuit board (14) being mounted in an inner portion of the resilient body (12).

5. An electrical switch assembly according to claim 4, characterized in that the cover (13) has a protrusion (19) on its inner surface in a central region, which protrusion extends into the cavity of the housing (11) and provides support for the printed circuit board (14).

6. The electrical switch assembly according to any of the preceding claims, wherein the resilient body (12) is made of a resilient thermoplastic material capable of operating in a temperature range of-85 ℃ to +85 ℃.

7. The electrical switch assembly according to claim 1, wherein the housing (11) is a rigid housing, the first and second openings (11a, 11b) are arranged opposite each other, and the resilient body (12) is attached to the first opening (11a) of the housing by overmoulding, the resilient body comprising a flange (12b) providing the surface, the flange being placed against a portion of the inner surface of the housing surrounding the first opening (11 a).

8. The electrical switch assembly according to claim 8, wherein the resilient body (12) further has an outer portion (15) configured as a button attached thereto by overmolding.

9. An electrical switch assembly according to claim 2, wherein the housing (11) is rigid, the first and second openings (11a, 11b) are arranged opposite each other, and the resilient body (12) has a curved portion (12d) with a flat portion which is placed against a portion of the inner surface of the housing (11) surrounding the first opening (11a), the tubular wall (18) of the cover pressing against the flat inner surface of the curved portion (12 d).

10. An electric switch assembly according to claim 10, characterized in that the tubular wall (20) projects from a flat inner surface of the curved portion (12 d).

11. The electrical switch assembly of claim 1, wherein the cover (13) is secured to the housing by ultrasonic welding beads.

12. The electrical switch assembly according to claim 1, wherein the cover (13) is fixed to the housing (11) by mechanical fasteners.

13. The electrical switch assembly according to claim 13, wherein the mechanical fastener is provided by a side appendix of the cover (13) inserted into a cavity of the housing (11), adjacent to two opposite inner walls, and anchored in a side opening (22) of said walls.

Technical Field

The present invention relates to a waterproof electrical switch assembly that is particularly resistant to contact with water.

Insulating electrical and electronic components, especially switches, is of paramount importance today. In this sense, electrical and electronic devices are subject to increasingly stringent tests in terms of use operations, which must be subjected to combination tests, the most stringent of which are immersion in water, pressurized water and salt water vapor to ensure that water does not penetrate into the component or that water does not affect the component with minimal penetration.

Furthermore, in today's automotive industry, in addition to the switchgear achieving its proper sealing function, preventing water from penetrating into and reaching the switchgear, it is also vital to optimize, miniaturize, reduce chemical adhesives, and use recyclable materials that are easy to manufacture.

Background

One of the most widely used systems for protecting electric switches at present uses thermoplastics for over-moulding, which, although expensive, do not allow to close all the water inlet channels to the internal electric or electronic components.

The patent document US 8822863-B2 discloses a sealed switch resistant to the penetration of water and/or moisture, said switch being formed by a casing 2, the casing 2 defining a cavity housing a PCB assembly formed by a PCB6, a tactile electric switch 7, other components such as a capacitor 8 or a resistor 9, and an electric cable 13e passing through an opening 14 of the casing 2.

The housing 2 has an upper opening 2A sealed by the elastic button 3, and a lower opening 2U sealed by the injection material 11 that can be molded, so that the housing 2 is completely sealed.

According to one embodiment, the button 3 may be overmoulded relative to the housing 2 during the injection/moulding process, so as to seal the upper opening 2A, whereas once the PCB assembly 5 has been inserted into the housing 2, a mouldable material 11, preferably polyamide (TPE-a), is injected, forming an adhesive attachment between said mouldable material 11 and the button 3, the housing 2 and the PCB assembly 5, so as to seal the lower opening 2U and the opening 14 of the housing 2, after curing thereof, assuming the shape of the internal cavity of the housing 2.

Furthermore, when the moldable material 11 is injected into the cavity of the housing 2, a seal is formed around the cable 13.

A hermetically sealed push-button switch made in a similar way is also described in patent application DE 102016013790a1, in which the push-button portion is overmoulded with respect to an upper portion of the casing, which houses the switch, and a lower portion of the casing, which is filled with epoxy resin.

DE 202016107304U1 discloses a hand-held emitter with improved waterproof protection (in particular improved waterproof jet protection) and safe switching behavior, comprising two shells configured to be coupled in the inserted state of an elastic sealing block 60, defining a shell, and comprising an upper shell 70 with a peripheral skirt 75 and one lower shell 10 with a peripheral skirt 14. A first of these housings 70 has an opening 71 through which opening 71 passes some keys 53 of some keys 51, which keys 53 are part of an elastic sealing block 60 arranged between the two housings. The keys 52 are designed to operate switches (of the switch pad 50) supported by the printed circuit board 30.

EP 1032004a2 discloses a watertight switching device having a body formed by two parts 31, 32 clamped together. The lower shell 32 has an upstanding peripheral flange 33 having an inwardly projecting lip 34 for clip-together engagement with a corresponding portion 35 of the upper part 31 to form a housing. An elastic operating member 36 in the form of an elastic button projects through the hole of the upper part 31 and has a downward projection 37 for operating the circuit device 11. Button 36 extends along the inner wall of upper portion 31 and is overmolded to the wall to form a seal therewith. The lower part 32 of the housing has another upstanding rib 38 which rib 38 is urged against the end face 39 of the elastomer to hold it in place when the two parts are clamped together.

Although the technique of overmoulding the push-button body described in the above-mentioned patent document obviates the need to use special adhesives or coatings, it can be noted that the operation of sealing the casing by injecting or filling the substance that must be consolidated within the cavity of the casing is still being used, resulting in complex and costly operations of assembling the switch.

The present invention proposes a solution to avoid the use of resin or the like to fill the casing of the switch, which provides water tightness by means of a physical barrier obtained by the interference between a continuous wall deriving from the closing cover of the opening of the casing, said wall surrounding the area where the switch is located, and the elastic body forming the push-button.

Disclosure of Invention

As described above, the present invention is intended to solve the problems associated with: the lack of water tightness of electronic products, and how these products are affected by corrosion and other problems such as short circuits.

The proposed solution avoids the use of adhesives, thereby eliminating problems such as air bubbles and air bubble detection difficulties, lack of cross-linking, neglect of homogeneity (homology over flight). Furthermore, the proposed solution makes the switch assembly easier to assemble together, increasing the system reliability and assembly stability, increasing the number of water barriers and thus the safety in relation to water tightness.

The proposed structure allows to increase the resistance to temperature and water by simultaneously modifying, under compression only, the elastic material, which can be chosen to use TPE (thermoplastic elastomer) suitable for the low temperature range, or silicone (LSR) for higher resistance, with low creep deformation and low compression set in the large temperature range.

The waterproof electrical switch assembly of the present invention comprises:

-closing the compartment; and

-an electric switch housed within the closed compartment and having an electric conductor connected thereto;

the closed compartment is arranged inside a casing defining a cavity having two openings, a first opening hermetically sealed by a compressible elastomeric body attached to the casing and a second opening hermetically sealed by a cover, all according to the known prior art, in particular disclosed in document US 8822863-B2.

In contrast to this known structure of the switch assembly, the invention is characterized in that the above-mentioned compressible elastomeric body extends partially into the cavity of the casing and provides a surface on which the switch is arranged (for example mounted), the above-mentioned closing cover of the second opening of the casing also comprising, on its inner surface, at least one tubular wall (of any suitable cross-section) which is inserted into the cavity and which establishes a perimetrical interference contact with (i.e. presses along the entire profile of) said surface of the elastomeric body, this tubular wall of said cover completely surrounding the switch, thus ensuring its waterproofness. In other words, the tubular wall of the inner surface of the cover provides an additional barrier when closing the cover of the second opening of the housing, which second opening provides access to the cavity containing the switch.

This solution can be achieved by a rigid casing, the first and second openings being arranged opposite each other, an elastic body being attached to the first opening of the casing by overmoulding, the elastic body comprising an annular flange which rests against a portion of the inner surface of the casing which surrounds the first opening and defines the support surface for the switch.

Furthermore, it is also envisaged that an outer part is attached to the elastic body by overmoulding, the outer part being configured as a button.

In the second embodiment, the compressible elastomeric body does not have to be overmolded, which reduces the cost and operation of fitting it together, as well as providing effective water tightness.

In this second embodiment, too, a rigid housing is used, said first and second openings being arranged opposite each other, and in this example a compressible elastic body is introduced into the housing, protruding through the first opening, the curved portion of the elastic body having a flat portion which lies against a portion of the inner surface of the housing surrounding said first opening, said flat surface of said elastic body being pressed by said tubular wall of the inner surface of the cover. In this second embodiment, the elastic body also comprises a tubular wall, which extends towards the outside of the cavity of the casing, projecting from said bend until establishing a peripheral interference contact with the inner surface of said closing cap of the second opening, on which the free edge (with rounded transverse profile) of this tubular wall is pressed.

In this second embodiment, the tubular wall of the elastic body and the tubular wall of the cover have different widths and are very close to each other in the arrangement in which they are mounted together, so they provide a double watertight barrier.

In this second embodiment, since the elastic body is not attached to the body of the casing by overmoulding, it is not necessary to use an elastomer (elastomer) compatible with the material of the casing (typically a polymeric material), and therefore any elastomer available on the market can be used depending on the technical requirements of the application.

The elastomeric body is made of an elastic thermoplastic material capable of operating normally at a temperature in the range of-85 ℃ to +85 ℃.

The above-mentioned electric switch preferably comprises a printed circuit board supporting the electric or electronic switching components or devices and to which the ends of two insulated electric conductors are connected by welding, which are extended outside the casing through said elastic body, said printed circuit board being mounted in a recessed portion of said elastic body, inside the cavity of the casing, and surrounded by a peripheral wall providing a watertight function or, in the example of said second embodiment, by two walls.

The two insulated electrical conductors that converge in the switch exit to the outside through a side window of the casing occupied by an extension of said elastic body and through which said insulated electrical conductors pass, this type of arrangement thus determining the hermetic sealing of the aforementioned channels.

The cover that plugs the second opening of the housing is secured to the housing by ultrasonic welding beads (ultrasonic welds) or by mechanical fasteners.

In the example of application of the mechanical fastener, said mechanical fastener is provided by the coupling of a side appendix, for example a cover, inserted into a cavity of the housing, flush with two opposite internal walls and anchored on a side opening or recess of said internal walls. If there is a side opening of the housing, water can penetrate through the opening, but water will flow into the double-walled barrier, thereby maintaining the waterproof protection of the switch.

Based on what has been described above, it should be understood that the invention proposes to use the same flexible element, i.e. the above-mentioned elastic body, to insulate the switch or other electrical or electronic components housed in the cavity of the casing. In this way, the single elastic element covers the same waterproof protection in two areas (the area where the component is mounted in the cavity and the area for the cable), avoiding the separate joining elements, any type of adhesive or thermosetting resin, which have been used so far, and avoiding the increase of assembly costs.

One advantage of the above solution is that, depending on the technical requirements, it is possible to consider only one element to be replaced, namely the elastic body.

In addition to water tightness, another advantage is the mechanical protection of the actual electrical or electronic component or device, since the elements can be selected to protect it according to the requirements in terms of impact, external resistance, corrosion, etc.

It is to be understood that for geometrical positions such as parallel, perpendicular, tangential, etc., a deviation of at most ± 5 ° from the theoretical position defined by the term is allowed.

It is also to be understood that any range of values provided may not be optimal in terms of its endpoints and that modifications to the invention to adapt the endpoint may be required, which modifications are within the skill of the art.

Drawings

The above and other advantages and features will be more fully understood on the basis of the following detailed description of some embodiments, with reference to the accompanying drawings, which must be interpreted in an illustrative and non-limiting manner, wherein:

figure 1 is a cross-sectional perspective view of an electrical switch assembly of the present invention according to a first embodiment.

Figure 2 is a perspective view of the electrical switch assembly of figure 1 viewed through its lower surface with the cover removed, which allows viewing of the printed circuit board supporting the electronic switching components or devices, and the insulated electrical cables connected to the board.

Figure 3 is a perspective view of the switch assembly of the first two figures showing the button and the insulated cable exiting the housing.

Fig. 4 is a perspective view of the closure cap for the second opening of the housing showing the tubular wall derived from the inner surface of the closure cap and the sealing lip defining the free edge of the tubular wall and preferably having a circular cross-section.

Figure 5 is a cross-sectional perspective view of an electrical switch assembly of the present invention according to a second embodiment.

Figure 6 is a perspective view of the electrical switch assembly of figure 5, viewed through its lower surface, with the closing cover removed, which allows to see the printed circuit board supporting the switch, the tubular wall projecting from the elastic body surrounding said printed circuit board, and the insulated cable connected to said printed circuit board and extending to the outside, passing through the extension of the elastic body arranged in the side opening of the casing.

Figure 7 is a perspective view of the switch assembly of the embodiment of the first two figures showing the button and the insulated cable exiting the housing.

Detailed Description

In a first embodiment, shown in figures 1 to 3, a structure and/or design of the above-mentioned electric switch assembly is proposed, said assembly being conceived to show an external button element 15, i.e. a button that the user will press and subsequently actuate an electronic button enclosed within the switch assembly 10.

Said external button element 15 and the casing 11 are attached by means of an elastic body 12, which is overmoulded with respect to both the element 15 and the casing 11 and closes one of its openings 11a, so that water is prevented from entering the casing and said elastic body as long as there is a chemical adhesion and chemical compatibility between the two, resulting from the overmoulding. The closing cover 13, which closes the second opening 11b of the housing 11, which is directly opposite to the first opening 11a, will be described in detail below. The elastic body comprises a portion 12a arranged facing the push-button stem of the electric switch 10, which allows actuation upon deformation, acting on said external push-button 15. The portion of the elastomeric body 12 arranged within the cavity of the housing also has an annular flange 12b which rests against the inner surface of the housing adjacent to the first opening 11a of the housing 11.

Fig. 2 shows the above-described switch assembly 10, in which the closing cover 13 has been removed, which allows to see (via the second opening 11b of the casing 11) the printed circuit board 14 inside the cavity of the casing 11, which supports the electronic switching components or devices and to which the ends of the insulated electrical conductors 16 or cables are attached by soldering, which project towards the outside through the side windows 17 of the casing 11 (which are occupied by the extensions 12c of the overmolded elastomeric body 12), so that the electrical conductors 16 are embedded through said extensions 12c (see fig. 3), ensuring the watertightness of said channels.

The above-mentioned second opening is closed by a cover 13 which can be sealed by ultrasound, by a harpoon-type closure (attachment of the cover interlocked in the wall of the housing 11) or even by an adhesive, but this should be avoided.

According to the proposal of the invention, the above-mentioned cover 13 comprises, on its internal surface, a tubular wall 18 (in this example with a rectangular cross section) which is inserted into the cavity of the casing 11 until a peripheral interference contact is established, the free edge of which (advantageously with a rounded transverse profile) presses against the surface of the elastic body (provided by an annular flange 12b attached by overmoulding to the internal surface of the cavity of the casing 11 adjacent to the first opening 11a), this tubular wall 18 of the cover 13 completely surrounding the above-mentioned printed circuit board 14 carrying the switching components and being fitted into the internal portion of the elastic body 12, thus ensuring waterproofness.

It is essential to ensure that the elastic body 12 is pressed along the perimeter into the entire contour of the position of the switching electronic component or device, so that the tubular wall 18 of the cover 13 must be adapted to said elastic body 12, despite the height variations due to the interaction with the insulated electrical conductor 16. Fig. 4 shows a terminal profile of said wall 18, wherein it can be seen that the wall has a peripheral lip (perimetral lip) or arched portion designed to allow the passage of the cable 16 therethrough.

Furthermore, in the solution of the first embodiment, the cover 13 has, in a central portion of its inner surface, a projection or spacer 19 that supports the printed circuit board 14 so that it is held in position and mounted in an inner portion of the elastic body 12 (see fig. 1), but at the same time prevents the printed circuit board 14 from having a support and an opposite reaction force when the push-button exerts a force on the electronic components or means of the switch and the latter exerts a force on the printed circuit board 14.

Fig. 5 to 7 show a second embodiment applying the same principles of the invention, however in this case the elastic body 12 does not have to be overmoulded, thus reducing the cost of the manufacturing process shown and obtaining a similar water tightness condition.

In this second embodiment, the elastic body 12 is introduced into the cavity of the housing 11, the push button portion thereof protrudes through said first opening 11a and is held in place by the flat surface of the curved portion 12d, which is supported on the inner edge of the cavity adjacent to said opening 11a, and similarly, the printed circuit board 14 is mounted in the inner portion of this elastic body 12 in the region divided by the curved portion 12 d.

In this example, in addition to the cap 13 having a tubular wall 18, the free edge of which (with rounded transverse profile) presses on the above-mentioned flat surface of the curved portion 12d of the elastic body 12, completely surrounding the electronic components or devices of the switch, the polymeric body 12 itself has another tubular wall 20 which extends towards the outside of the cavity of the housing 11 until it establishes a peripheral interference contact with, presses on, the inner surface of said closing cap 13 of the second opening 11 b.

As can be seen in fig. 5, the tubular wall 18 of the cap 13 and the tubular wall 20 of the elastic body 12 have different widths, which are very close to each other and mounted together.

The same fig. 5 shows an example of the attachment of the cover 13 to the housing 11 by means of the interlocking of the handle or appendix 21 of the cover in the side opening 22 of the housing 11. The watertightness of the electronic components or devices of the switch associated with the printed circuit board 14 is guaranteed in view of the use of the double barrier provided by the walls 18, 20.

Fig. 6 is a view similar to fig. 2 described above, showing the printed circuit board 14 arranged to be mounted in a central portion of the elastomeric body 12 arranged within the cavity of the housing 11. In this figure, a tubular wall 20 can be seen, which derives from the elastic body 18 and extends to the outside until it bears against the inner surface of the cover 13, as explained with reference to fig. 5. It can also be seen that the cable 16 exits through the elastomeric body, extending towards a side window formed in the housing 11.

Fig. 7 is similar to fig. 3 and shows the switch assembly, the upper portion of which can be seen to act as a push button.

One advantage of this second embodiment is that the elastomeric body does not have to be made of an elastomer compatible with the material of the housing (typically a polymer material) since it is not attached by overmolding.

It is to be understood that different parts constituting the invention described in the embodiments may be freely combined with parts described in other different embodiments, even if the combination is not explicitly described, provided that such combination is not disadvantageous.

Likewise, it must be noted that the teachings of the present invention are applicable to sealing other electrical or electronic components or devices comprised in the closed compartment from water.