DE102022202354B3 - Glass assembly for a rearview mirror assembly for motor vehicles, and method for manufacturing a glass assembly - Google Patents

Abstract

The invention relates to a glass assembly (1) for motor vehicles, having a carrier plate (30) and a mirror assembly (10) comprising a liquid crystal cell (12) held at a distance from a first surface of the carrier plate (30) for observing the following traffic, the degree of reflection of the mirror assembly (10) is designed to be changeable by a control device, wherein the glass assembly (1) further comprises a surface heating element (20) with electrically contactable connection elements (22) and these are cast in a first contacting area (22a) with a flexible casting compound (40), and wherein the carrier plate (10) has connection elements (36) injection-molded on a second surface in the area of recesses (34), and wherein the electrically contactable connection elements (22) also have the injection-molded connection elements in the area of the recesses (34) of the carrier plate (30). (36) cast with the same flexible casting compound (40). are.

Description

The present invention relates to a glass assembly for a rearview mirror assembly for motor vehicles, and a method for manufacturing a glass assembly.

Glass assemblies for automotive rearview mirror assemblies have a reflective surface that allows for viewing of traffic behind. The rear-view mirror arrangements are usually designed to be able to be dimmed as well. This avoids being blinded by vehicles driving behind when driving in the dark. In the case of rear-view mirror arrangements that can be automatically dimmed, light sensors measure or record the difference in brightness between the area in front of the car and the area of traffic to the rear. The measured values are then forwarded to evaluation and control electronics and the reflectivity of the mirror arrangement is changed accordingly. This uses mirror assemblies that include optical cells. These optical cells can be in the form of liquid crystal cells, for example. With these mirror arrangements, the reflectivity can be changed when an electric field is applied.

In addition, the rear-view mirror arrangements for the outside area are often designed to be heatable. This avoids impairment of visibility, particularly in the winter months, due to water droplets, frost and icing. Conventional mirror assemblies that are not equipped with an optical cell comprise a glass plate, a reflective coating and a surface heating element arranged on the back of the reflective coating. This surface heating element is usually a carrier film that includes an electrical resistance heater and is bonded to the reflective coating that is protected by a layer of lacquer. In this case, the surface heating element is arranged on a carrier plate which carries the mirror assembly. The heat generated by the resistance element is conducted through the reflective coating to the outward-facing glass plate in order to de-ice the outer surface there, for example.

However, the known surface heating elements described at the outset and their arrangement are unsuitable for a mirror assembly that includes a liquid crystal cell.

Gluing the carrier plate-surface heating element-liquid crystal cell-glass plate leads to tension due to the tolerances of the individual parts within the liquid crystal cell. Furthermore, the direct contact between the surface heating element and the liquid crystal cell exerts pressure on the liquid crystal cell. These stresses, as well as the pressure and temperature effects, cause accumulations of liquid crystals in the liquid crystal medium in the liquid crystal cell, which leads to clear, dark spots in the optical image visible to the user. The ones from the DE 10 2013 203 530 A1 known rear-view mirror arrangement solves this problem in such a way that the surface heating element is glued to the support plate, but the mirror assembly with the liquid crystal cell is held on the support plate at a distance from the surface heating element, so that tension and direct contact between the surface heating element and the liquid crystal cell are avoided.

However, the previously known rear-view mirror arrangement has the disadvantage that the liquid crystal cell can be damaged when the surface heating element makes contact with the on-board electrical system of the motor vehicle. This is due to the fact that commercially available flat heating elements F are designed as flexible foil elements and the electrical connection elements E1, E2 attached thereto are sealed with a casting compound V at their first contacting areas K1 fixed on the foil element. The flat plugs on the vehicle electrical system are then plugged onto the angled lugs L protruding outwards from the casting compound V. This internal prior art, which is known to the person skilled in the art through his general knowledge, and relates to an arrangement and design of the surface heating elements with contact elements is in the 1 and in a detailed representation of the contact elements in the 2 shown.

However, these known surface heating elements cannot absorb the plugging forces that occur during the contacting process with the plug on the vehicle electrical system, and there is a risk that these will damage the liquid crystal cell. During assembly, this contacting process must therefore be carried out first before the mirror assembly with the liquid crystal cell is connected to the carrier plate. Only after the surface heating element has made contact with the connector on the vehicle side is the mirror assembly mounted and fixed to the carrier plate by gluing it to the outer edge of the carrier plate. This assembly sequence is complex and can lead to damage to the casting compound in the area of the contact elements on the surface heating element.

From the EP 1 598 237 B1 an exterior rearview mirror arrangement with at least one built-in lamp is already known. A circuit board with electrical/electronic components is assigned to this built-in light. The circuit board is via plug contacts contacted, the plug contacts protruding through openings in a carrier plate. The circuit board is encapsulated using a casting compound.

the DE 10 2007 013 598 B3 shows a mirror pane with a substrate made of plastic and a heating device and a corresponding manufacturing method of a mirror pane for an exterior rear view mirror arrangement.

The document U.S. 5,151,824A shows an exterior rearview mirror assembly with an electro-optical mirror assembly and an associated electrical contact of the mirror assembly.

The object of the present invention is therefore to develop a glass assembly for a rearview mirror assembly for a motor vehicle with an automatically dimming mirror assembly with an optical liquid crystal cell and a surface heating element to achieve a heating function in such a way that the assembly and contacting of the surface heating element with the vehicle electrical system can be carried out easily, wherein in particular no damage to the liquid crystal cell or impairment of the optical image of the image produced by the mirror assembly is achieved.

This object is achieved by the features specified in claim 1.

By the glass assembly specified in claim 1, wherein the carrier plate has connection elements injection-molded on the second surface in the area of the recesses, and the electrically contactable connection elements in the first contact area with the flexible casting compound additionally in the area of the recesses of the carrier plate with the injection-moulded connection elements with the same flexible casting compound, a seal can be achieved at the same time and the "plugging forces" that occur when the plug is plugged onto the electrical connection elements are reduced. Due to the connection elements molded onto the carrier plate, which are also embedded in the casting with the flexible mass, the insertion forces can be transmitted to and absorbed by the connection elements on the carrier plate.

Additional contact points and cables can be avoided.

In an advantageous embodiment, the carrier plate is designed with injection-molded struts and/or ribs for better connection and absorption of the forces when making contact with the heating plate.

Advantageously, the electrical connection elements are angled upwards at their second end region, which is also referred to as the second contacting region and is contacted with an onboard plug for the electrical connection to the vehicle electrical system. This increases the effect of the fixing of the electrical connection elements on the carrier plate by the casting compound. Of course, this second end area or second contacting area is not embedded in the casting compound, but protrudes from the casting compound.

The soft-elastic casting compound is designed to be flexible and elastic at low temperatures in terms of its material properties for the purpose of sealing the first contacting areas and for the purpose of connecting the electrical connection elements to the carrier plate. The casting compound is usually a hardening casting resin that includes a two-component plastic. For example, a material with the designation Rapid Y-16 can be used as the casting compound.

A further aspect of the invention specifies a simplified and cost-effective method for producing the glass assembly for a rear-view mirror arrangement comprising a mirror assembly with a liquid crystal cell, carrier plate and surface heating element with contact elements for contacting the vehicle electrical system.

In the manufacture of the glass assembly according to the invention for a rear-view mirror arrangement, the components are first provided: mirror assembly, carrier plate and heating surface element with connected connection elements. In contrast to the standard heating surface element described at the outset, the heating surface element is provided without cast-in connection elements.

In a first assembly step, the heating surface element is connected to the surface of the first surface of the carrier base plate of the carrier plate. Subsequently, in a further second assembly step, the mirror assembly is fixed to the carrier plate in such a way that a housing gap in the form of an air gap remains between the heating surface element and the liquid crystal cell.

In a final assembly step, the heating surface element is encapsulated in the area of the first contacting area of the connection element using an encapsulation compound together with the carrier plate in the area of the injection-molded connection elements.

This method according to the invention achieves process-reliable, quick and damage-free assembly of the glass assembly.

Alternatively, the method according to the invention can also be carried out in such a way that the second method step and the final method step are exchanged.

The heating surface element is preferably connected by means of an adhesive connection.

Further advantageous configurations and developments of the glass assembly according to the invention for a rear-view mirror arrangement result from the dependent claims.

Preferred embodiments of the glass assembly for a rear view mirror assembly for a motor vehicle are described below by way of example, reference being made to the accompanying drawings for purposes of illustration.

• 1 ein Heizflächenelement mit elektrischen Anschlusselementen und Vergussmasse gemäß dem Stand der Technik,
• 2 ein Detailausschnitt des in der 1 dargestellten Heizflächenelements im Bereich der elektrischen Anschlusselemente,
• 3 eine Glasbaugruppe im montierten und vergossenen Zustand der elektrischen Anschlusselemente in einer Ansicht auf eine zweite Fläche der Trägerbodenplatte der Trägerplatte,
• 4 ein Detailausschnitt des in der 3 dargestellten Bereichs der mit der Trägerplatte vergossenen elektrischen Anschlusselemente,
• 5 ein Schnitt durch die Glasbaugruppe in einem Ausschnitt eines vergossenen Bereichs der Trägerplatte längs des Schnitts A-A der 4,
• 6 eine Draufsicht auf die Trägerplatte der Glasbaugruppe in der montierten und vergossenen Situation,
• 7 eine Detaildarstellung des in der 6 gekennzeichneten Bereichs eines Anschlusselements in der vergossenen Situation,
• 8 eine Detaildarstellung des in der 6 gekennzeichneten Bereichs eines Anschlusselements im Bereich der Ausnehmung der Trägerplatte mit Anbindungselementen vor dem Verfahrensschritt des Vergießens mit der Vergussmasse,
• 9 eine Explosionsdarstellung der Glasbaugruppe einer Rückspiegelanordnung; und
• 10 eine Detailansicht einer weiteren Ausführungsform eines Anschlusselements.

Show it:

• 1 a heating surface element with electrical connection elements and casting compound according to the prior art,
• 2 a detail of the in the 1 illustrated heating surface element in the area of the electrical connection elements,
• 3 a glass assembly in the mounted and cast state of the electrical connection elements in a view of a second surface of the carrier base plate of the carrier plate,
• 4 a detail of the in the 3 illustrated area of the electrical connection elements cast with the carrier plate,
• 5 a section through the glass assembly in a section of a cast area of the carrier plate along the section AA of 4 ,
• 6 a plan view of the support plate of the glass assembly in the assembled and potted situation,
• 7 a detailed representation of the 6 marked area of a connection element in the cast situation,
• 8th a detailed representation of the 6 marked area of a connection element in the area of the recess of the carrier plate with connection elements before the method step of casting with the casting compound,
• 9 an exploded view of the glass assembly of a rearview mirror assembly; and
• 10 a detailed view of a further embodiment of a connection element.

The glass assembly 1 according to the invention essentially comprises, as can be seen from the exploded view of FIG 9 can be seen, a mirror assembly 10, a surface heating element 20 and a support plate 30 for supporting the mirror assembly 10 and the surface heating element 20.

The glass assembly 1 described below is part of a vehicle exterior mirror, which includes a mirror base and a mirror head. The vehicle exterior mirror is attached in a known manner to the driver's or passenger's outside of the motor vehicle. The mirror head is arranged on the mirror base so that it can be folded or pivoted and has a half-shell-shaped housing with a receiving space that has a receiving opening. The glass assembly 1 described below is accommodated in the accommodation space.

The carrier plate 30 is coupled to the housing. The support plate 30 is further provided with attachment means intended to allow the coupling of a position adjustment mechanism/glass adjuster, such an adjustment mechanism being operable from inside the vehicle to adjust the support plate 30 and consequently the mirror assembly itself, depending on vision needs of the driver of the vehicle. The back of the support plate 30 is connected to the glass adjuster and carries the mirror assembly 10 on its front. The mirror assembly 10 is fixed to the support plate 30 at the edge. The carrier plate 30 is mounted on an amplifier plate of the mirror head. This customary design is known to those skilled in the art.

The mirror assembly 10 is equipped with an automatic dimming function. One or more light sensors are provided for this purpose, for example, with which the light intensity of the surroundings is recorded from the direction of the following traffic. In addition, the light intensity of the area in front of the motor vehicle is recorded. The mirror assembly 10 is then controlled and darkened as a function of the measured signals. The illustration and detailed description of the sensors detecting the light intensity, the control and evaluation electronics are omitted. This is known to the person skilled in the art from the prior art.

The mirror assembly 10 includes a liquid crystal cell 12 for changing the degree of reflection therefore described below using an example. Of course, other embodiments are also possible. The liquid crystal cell 12 has a transparent front support layer, a reflective rear support layer 14 and an electrically addressable liquid crystal layer comprising a liquid crystal medium arranged between the support layers. For electrical control, the liquid crystal layer is arranged between two electrically conductive layers. This technology based on liquid crystals exploits the effect that when an electric field is applied to the liquid crystal cell, the liquid crystal molecules orient themselves parallel to the electric field. In the basic state, ie without an electrical field, the liquid crystal molecules are aligned in the longitudinal direction, ie in the direction in which the light passes through. In order to obtain this alignment, additional alignment layers are provided. These alignment layers are interposed between the electrically conductive layers and the liquid crystal layer.

The rear-side reflective support layer 14 is arranged on the side facing the support plate 30 . This layer is produced, for example, by vapor deposition or sputtering or spraying.

The mirror assembly 10 is, as is particularly evident from FIG 5 can be seen, attached to the carrier plate 30 at a distance.

The carrier plate 30 is designed as an injection molded part made of a plastic material and essentially follows the shape or outer contour of the mirror assembly 10.

The carrier plate 30 has a carrier base plate 31 with an end face 31a pointing to the front side V and a rear side R. FIG. The front side is the side facing the mirror assembly 10 . the 3 shows an oblique view of the back of the carrier plate 30.

The carrier base plate 31 is designed on the front with bearing points for supporting the mirror assembly 10 . These support points are designed, for example, as web-shaped support points arranged at the edge. When the mirror assembly 10 is held and supported on the carrier plate 30, a gap remains between the carrier base plate 31 and the mirror assembly 10.

From the point of view of 3 it can be seen that an annular wall 32 is formed on the rear side R of the carrier base plate 31 . A glass adjuster (not shown) is fastened within this wall 32 . Furthermore, grid structures 37 in the form of segments of a circle can be seen outside of the wall 32 , which are produced during injection molding and which are important for the dimensional stability of the carrier plate 30 .

At the edge, two recesses 34 are formed in the carrier base plate 30, which are designed essentially the same. 8th shows one of the two recesses 34 in a detailed view. The recesses 34 comprise a peripheral web-like edge region 35 which delimits an oval interior space. Within the edge area 35, connection elements 36 are formed in the area of the recesses. These connecting elements 36 are designed as ribs 37 arranged in the shape of a cross. The four molded ribs 37 extend obliquely inwards starting from the edge area 35 and end at a distance from a central area 38.

Two openings 33 are formed on both sides of the central area 38 in the area of the recesses 34 , which are used for the positioning and the passage of electrically contactable connection elements 22 of the surface heating element 20 .

The surface heating element 20, which is used to generate thermal radiation and to heat the mirror assembly 10, is arranged on the mirror assembly 10-facing end face 31a of the carrier base plate 31. The surface heating element 20 is preferably glued to the carrier base plate 31 over its entire surface. This surface heating element 20 is a plate-shaped element which is usually designed as a flexible carrier film. The flexible carrier film comprises, in a known manner, an electrical resistance heater and two connection elements 22, 22' that can be electrically contacted. As can be seen from the drawing, this surface heating element 20 is arranged at a distance from the mirror assembly 10 . A gap S thus remains between the flat heating element 20 and the mirror assembly 10 and runs almost over the entire end face 31a.

From the exploded view of the 9 it can be seen that the two connection elements 22 have a first contacting area 22a fixed on the surface heating element 20 and a second contacting area 22b leading to the outside. This second contact area 22b forms the contact point for the electrical connection to the vehicle electrical system of the vehicle, which is not shown. The connecting elements 22 are designed as angled brackets onto which a flat plug can be plugged during final assembly. When the voltage of the vehicle electrical system is applied, a current flow takes place between the two connection elements 22 acting as electrodes in a substantially homogeneous distribution over the entire surface of the surface heating element 20.

5 shows a sectional view of the glass assembly 1, with the electrically contactable connection elements 22 in the first contacting area 22a being cast with a flexible casting compound 40, additionally in the area of the recesses 34 of the carrier plate 30 with the injection-molded connection elements 36 with the same flexible casting compound. The potting compound completely fills the inner area of the recesses 34, which is delimited by the peripheral edge area 35, so that both the first contacting area 22a on the surface heating element 20 and the connection elements 36 are embedded in the potting compound and kept sealed. The connecting elements 22 are arranged in the area of the recesses in such a way that the angled tab-shaped second contacting areas 22b are passed through the openings 33 to the rear. Im shed in the 4 , 5 , 6 and 7 In the state of the finished glass assembly 1 shown, the second contacting region 22b protrudes outwards from the casting compound 40 on the rear side of the carrier plate 30 in order to be able to be contacted in this way.

The flexible casting compound 40 is designed to be flexible and elastic at low temperatures in terms of its material properties for the purpose of sealing the first contacting areas and for the purpose of connecting the electrical connection elements to the carrier plate. The casting compound is usually a hardening casting resin that includes a two-component plastic.

In an alternative embodiment, the connecting elements 22 'as it is from the detailed view of 10 can be seen, designed with recesses 22c. These recesses 22c are each introduced on both sides on the leg of the tab-shaped, angled second contacting region 22b extending perpendicularly to the rear side, and on a further opposite leg 22d extending perpendicularly to the rear side. The two recesses 34 and 33 as well as the recesses 22c on the connection element 22′ enable a form-fitting and stable connection of the combination of casting compound 40, connection elements 22′ and carrier plate 30. The form-fitting connection described above results in a stable connection despite the elastic casting compound 40 of the association.

The method according to the invention for producing glass assembly 1 essentially comprises the following steps: First, the components: mirror assembly 10, support plate 30 and heating surface element 20 with fixed—not cast—connecting elements 22 and 22' are provided.

In a first assembly step, the heating surface element 20 is connected flat to the end face 31a of the front side of the carrier base plate 31 of the carrier plate 30 . In this case, the alignment and connection takes place in such a way that the connection elements 22 or alternatively 22' are arranged by means of their second contacting area in the area of the recesses 34 and protrude through the openings 33.

Subsequently, in a further assembly step, the mirror assembly 10 is fixed to the front side V of the carrier plate 30 in such a way that a housing gap S in the form of an air gap remains between the heating surface element 20 and the mirror assembly 10 over almost the entire end face 31a.

In a final assembly step, the heating surface element 20 is encapsulated in the area of the first contacting area 22a of the connection element 22 or alternatively 22` using an encapsulation compound 40 together with the carrier plate 30 in the area of the injection-molded connection elements 36 . Here, the casting compound 40 completely fills the inner area of the peripheral edge area 35 . In the cured, cast state, the second contacting regions 22b protrude at an angle from the casting compound 40 on the rear side of the carrier plate 30 .

In an alternative variant of the method according to the invention, in a first assembly step the heating surface element 20 can first be connected flat to the end face 31a of the front side of the carrier base plate 31 of the carrier plate 30 . In this case, the alignment and connection takes place in such a way that the connection elements 22 or alternatively 22' are arranged by means of their second contacting area in the area of the recesses 34 and protrude through the openings 33.

In a subsequent second assembly step, the heating surface element 20 is then encapsulated in the area of the first contacting area 22a of the connection elements 22 or 22 ′ using an encapsulation compound 40 together with the carrier plate 30 in the area of the injection-molded connection elements 36 . Here, the casting compound 40 completely fills the inner area of the peripheral edge area 35 . In the cured, cast state, the second contacting regions 22b protrude at an angle from the casting compound 40 on the rear side of the carrier plate 30 .

Finally, in a final assembly step, the mirror assembly 10 is fixed on the front side V of the support plate 30 in such a way that between the heating surface element 20 and the mirror assembly 10 there is a housing gap S in the form of an air sp old remains over almost the entire end face 31a.

reference list

1

glass assembly

10

mirror assembly

12

liquid crystal cell

14

reflective layer

20

surface heating element

22, 22'

electrically contactable connection elements

22a

first contact area

22b

second contact area

22c

recesses

22d

leg

30

backing plate

31

support base plate

31a

face

32

annular wall

33

breakthroughs

34

recess

35

peripheral edge area

36

connection elements

37

ribs

38

middle area

40

potting compound

Claims (9)

Glass assembly for a rear-view mirror arrangement (1) for motor vehicles, a) with a mirror assembly (10) comprising a liquid crystal cell (12) for observing the following traffic, the degree of reflection of the mirror assembly being designed to be variable by a control device, b) with a surface heating element (20) , by means of which thermal radiation can be generated, wherein the surface heating element (20) comprises a plate-shaped element with integrated heating resistors and electrically contactable connection elements (22, 22') with a first and a second contacting area (22a, 22b), which are arranged on the plate-shaped element and are connected to the plate-shaped element in the first contacting area (22a) with a flexible casting compound (40), c) with a carrier plate (30) which is designed to hold the mirror assembly (10), and the one carrier base plate (31) with a first facing to the mirror assembly surface (31a) and a two ten opposite surface, wherein the carrier base plate (31) has recesses (34), d) wherein the flat heating element (20) is arranged on the first surface (31a) of the carrier base plate (31) in such a way that the electrically contactable connection elements (22, 22') protrude through the associated recesses (34) of the carrier base plate (31), e) the mirror assembly (10) being held on the carrier plate (30) in such a way that there is an air gap (p ) remains, characterized in that f) the carrier plate (10) has connection elements (36) injection-moulded on the second surface in the area of the recesses (34), and g) that the connection elements (22, 22') which can be electrically contacted are in the first contacting area ( 22a) with the flexible casting compound (40) additionally in the area of the recesses (34) of the carrier plate (30) with the injection-molded connection elements (36) with the same flexible casting compound (40 ) are shed. Glass assembly (1) for a rear-view mirror arrangement for motor vehicles claim 1 , characterized in that the flat heating element (20) is glued flat to the first surface (31a) of the carrier base plate (31). Glass assembly (1) for a rear-view mirror arrangement for motor vehicles claim 1 or 2 , characterized in that the connecting elements (36) are designed as ribs molded onto the carrier plate (30). Glass assembly (1) for a rearview mirror arrangement for motor vehicles according to one of the preceding claims, characterized in that the recesses (34) have a peripheral edge region (35) which delimits an inner region. Glass assembly (1) for a rear-view mirror arrangement (1) for motor vehicles claim 4 , characterized in that in the inner region of the recesses (34) a number of openings (33) are introduced, through which the connecting elements (22) protrude by means of their second contacting region (22b). Glass assembly (1) for a rear-view mirror arrangement (1) for motor vehicles according to one of the preceding claims, characterized in that the second contacting areas (22b) of the electrically contactable connection elements (22`) are formed angled like tabs and lateral recesses (22c) are made in the tabs. Glass assembly (1) for a rear-view mirror arrangement (1) for motor vehicles according to one of the preceding claims, characterized in that the connecting elements (22`) have a further leg (22d) which is arranged in the region of the first contacting region (22a) and in which lateral recesses ( 22c) are introduced. Method for producing a glass assembly (1) according to one of Claims 1 - 7 with the following steps: a) providing a mirror assembly (10), a carrier plate (30) and a surface heating element (20) b) surface connection of the surface heating element (20) to the first surface (31a) of the carrier base plate (31) of the carrier plate (30 ) in such a way that the connecting elements (22, 22') are arranged in the area of the corresponding recess (34) by means of their second contacting area (22b) and protrude through openings c) fixing the mirror assembly (10) on the front side (V) of the carrier plate ( 30) in such a way that a housing gap (S) in the form of an air gap remains between the surface heating element (20) and the mirror assembly (10) a flexible casting compound (40) together with the carrier plate (30) in the area of the recesses (34) and the injection-molded connection elements (36), the second contacting areas (22b) au protrude from the casting compound (40) on the back of the carrier plate (30). Method for manufacturing a glass assembly (1). claim 8 , wherein step d) is carried out first after step a) and b) and then step c).

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