Vehicle door handle and method of manufacturing such a vehicle door handle

Abstract

A vehicle door handle (1) comprises a housing (2a, 2b) with a grasping portion (3) and a base portion (4). The grasping portion (3) is integrally formed with the base portion (4) and extends at an angle therefrom. A support member (6) is received in the housing (2a, 2b), which extends at least in sections both in the base portion (4) and in the grasping portion (3). The grasping portion (3) of the housing (2a, 2b) is fixedly coupled or integrally connected to a coupling member (7), which extends on one side out of the base portion (4) of the housing (2a, 2b) to allow coupling to a body component (10) of a motor vehicle. The coupling member (7) is characterised in that a holder (6a) for an electronic printed circuit board (12) is formed in the support member (6). The support member (6) is formed with a circuit board (12), which is at least partially overmoulded with at least one plastic material for the purposes of stiffening and protection. The plastic forms a stiffening layer (14) which is applied in direct contact with the printed circuit board (12.

Description

[0001] The application relates to a vehicle door handle. In particular, the application relates to a vehicle door handle with a housing which has a grasping portion and a base portion. The grasping portion and base portion are angled relative to each other.

[0002] The base portion of the vehicle door handle is intended for placement on a body part of a vehicle. The grasping portion extends from the base portion in a curved or angled manner to allow easy access to the grasping portion for the user to operate a vehicle flap or vehicle door. Due to its spatial orientation, the grasping portion allows a user to reach under or over the grasping portion, thus ensuring convenient operation.

[0003] A support member is accommodated in the housing, extending in sections both in the base portion and in the grasping portion. The support member thus represents a mechanically continuous connection within the grasping portion and base portion. Furthermore, the support member is connected to a coupling member. This extends out of the base portion of the housing on one side and enables mechanical fixing or coupling to a door or flap of a motor vehicle. The coupling member has means which, together with associated means on the vehicle, allow the vehicle door handle to be secured to the vehicle. The support member is rigidly coupled or integral with the coupling member.

[0004] Vehicle door handles have a wide variety of shapes and functionalities. What they have in common, however, is that they have a mechanical access function which provides a stable access area to move a door or flap on the vehicle. A vehicle door handle of the type mentioned, in particular with one-sided attachment to a vehicle and a geometry extending from it that allows it to be gripped in a grasping portion, is used both as a fixed vehicle door handle with electronic control detection and with a mechanical functionality for emergency opening. In normal vehicle operation, however, such a vehicle door handle is operated in a fixed manner, i.e. without any significant relative movement between the vehicle door handle and the vehicle. The handle is then used to move a released door and to hold detection components that trigger a mechanical opening of the door via a signal path.

[0005] The vehicle door handle must have both mechanical and electronic components to ensure the required mechanical stability and to detect user actions or approaches. In addition, communication means such as transmitting and receiving coils can also be integrated into the vehicle door handle.

[0006] The installation space in such a vehicle door handle is very limited. Nevertheless, the operational capability of the electronic components housed in it must be permanently guaranteed. Suitable measures must be taken to protect these electronic components from environmental influences. Accordingly, it is common practice to accommodate electronic components in corresponding holding areas or containers, which are then filled with a plastic material to protect the electronic components.

[0007] Document WO 2022 / 106080 A1 describes a vehicle door handle with an electronic assembly. The electronics assembly includes detection devices such as capacitive sensors and communication elements for keyless access, which are positioned within a container installed in the vehicle door handle. The electronic assembly is surrounded in the container with a potting compound that forms a protective layer against moisture and dirt.

[0008] The realization of a plastic potting in vehicle door handles, especially those which are fixed to vehicles on one side and are exposed to considerable mechanical deformation loads, as they are subject to leverage forces, is at the expense of the installation space and makes the handles heavy and bulky.

[0009] The present invention aims to provide vehicle door handles with protected electronic components that have optimized installation space requirements and improved mechanical stability. This is achieved by a vehicle door handle having the features of claim 1 and a corresponding method of manufacture.

[0010] The vehicle door handle according to the invention has a holder for an electronic printed circuit board in the support member. The support member is responsible for holding a substantial part of the mechanical forces acting on the vehicle door handle when it is attached to a vehicle via the coupling member. The printed circuit board is accommodated by the arrangement directly in or on the support member, i.e. in the area with the best possible mechanical reinforcement, which extends inside the housing in the vehicle door handle. In order to improve the protection of the electronic components on the printed circuit board and at the same time optimize the mechanical strength of the vehicle door handle, the printed circuit board is overmolded with a plastic so that the plastic forms a stiffening layer around the printed circuit board or at least around sections of the printed circuit board. The overmolding step creates a plastic layer that lies against the printed circuit board and its electronic components without any gapping. As a result, mechanical effects on the printed circuit board and its elements are dissipated and the stiffening layer can also contribute to the stiffening of the vehicle door handle, as the printed circuit board is arranged in the holder of the support member.

[0011] In contrast to potting, overmoulding involves inserting the printed circuit board into an injection mould and then encapsulating it with a heated, liquefied plastic in a known manner. After cooling and removal of the overmolded printed circuit board, however, in contrast to potting the component, there is an integral component consisting of the printed circuit board and the surrounding layer, without the need for a container that remains permanently bonded to the potting compound. Due to the controlled pressure conditions and the use of appropriate devices, the absence of gaps in all areas between the printed circuit board and the components arranged on it and the plastic layer can be better guaranteed than with a potting compound. Plastics are available for overmolding in suitable devices, which can absorb higher mechanical loads than a potting compound after setting with the desired flexibility. This is particularly true when considering the time required for setting potting compounds. Overmoulding regularly only requires cooling times, so that mechanically stable layers can also be produced in fast production processes in this way. Potting with epoxy resins, for example, leads to long production times, gaps between the printed circuit board and the potting and possibly brittle layers. Overmolding with suitable thermoplastics forms gap-free, stable layers with the desired rigidity in fast production processes. In addition to thermoplastic elastomers, materials from the group of polyamides, polycarbonates and acrylonitrile-butadiene-styrenes, which enable high rigidity, are also suitable for overmolding.

[0012] The possibility of using much more resistant plastics during overmolding with fast processing to form the stiffening layer allows the mechanical stiffening to be improved while at the same time reducing the weight of the overmolded printed circuit board in contrast to an overmolded board. The formation of a stiffening layer on the printed circuit board through overmolding improves the mechanical stiffening and leads to a weight reduction of the vehicle door handle. The stiffening layer simultaneously provides a protective and barrier function for the printed circuit board as well as mechanical stiffening functions in the vehicle door handle. In addition to repelling moisture and gases from the components of the printed circuit board, the stiffening layer also distributes the load of mechanical forces acting on it. The stiffening layer thus counteracts both a threat to the integrity of the printed circuit board and the components due to acting forces and a deflection of the vehicle door handle, as forces from the support member can also be introduced into the stiffening layer.

[0013] The support member is preferably made of a metallic material and includes a bezel for holding the printed circuit board, which extends in the grasping portion.

[0014] This design ensures reproducible positioning of the printed circuit board in the grasping portion, where the electronic sensor components are placed closest to an operating action. The metal mounting frame acts both as mechanical protection for the printed circuit board and for electrical potential equalization around the board.

[0015] The printed circuit board, which is overmolded with plastic, is preferably inserted into the support member in such a way that the stiffening layer is in direct contact with the support member. This ensures improved mechanical stability and effective force transmission between the components, thereby increasing the service life of the vehicle door handle.

[0016] In a further development of the invention, the printed circuit board is overmolded together with parts of the support member, whereby the stiffening layer partially covers both the printed circuit board and the support member. This integration promotes structural uniformity, fixes the printed circuit board in its holder and provides additional protection for the electronic components.

[0017] The printed circuit board preferably contains electrical connections whose contact points are located within the stiffening layer. This ensures that the electrical connections are protected from environmental influences and mechanical stress, which improves the reliability of the electrical functions of the vehicle door handle.

[0018] It is advantageous if the printed circuit board has at least one sensor for detecting the operation of the vehicle door handle, which is covered by the stiffening layer. The sensor is thus protected from external influences, which improves the accuracy and reliability of the sensor technology and stabilizes the working conditions of the sensor. The stiffening layer can be overmolded thinner in the area of the sensor than in the surrounding area. This enables efficient sensor function and reduces a reduction in the sensitivity of the sensor due to the stiffening layer, without impairing the protective properties of the stiffening layer.

[0019] In a preferred embodiment of the invention, the housing is attached to the support member without any play in the base portion, while the support member is spaced apart from the housing in the grasping portion. This arrangement ensures a slack-free coupling between the housing and the carrier, but at the same time allows a certain freedom of movement of the housing relative to the carrier in the grasping portion, where the greatest operating forces are exerted on the vehicle door handle.

[0020] Preferably, a conductor coil for an inductive sensor is arranged on the printed circuit board in order to detect deformations of the housing. An inductive sensor benefits from mechanical stabilization through gap-free encapsulating by the overmolded stiffening layer and allows reproducible detection of deformations of the housing. Metallic targets can be arranged on the housing near the sensor for detection if the housing itself does not contain any detectable metallic components.

[0021] In a further embodiment of the invention, a capacitive sensor is used on the printed circuit board to detect the approach of an operator. The known advantages of capacitive sensors enable contact-free, intuitive operation of the vehicle door handle, for example by automatically unlocking the vehicle when the user approaches. At the same time, the capacitive sensor is protected by the gap-free stiffening layer.

[0022] In a preferred embodiment, sensors on the printed circuit board are at least partially exposed by recesses in the stiffening layer. This ensures that the sensors can work effectively in areas that require particular sensitivity without being impaired by the stiffening layer. The stiffening layer can be designed with recesses in the sensor areas for this purpose.

[0023] It is advantageous if elastic sealing means are arranged between the stiffening layer and the housing. These sealing means protect against the ingress of water or dirt and improve the durability of the vehicle door handle. Furthermore, a supporting and damping effect can be developed between the printed circuit board and the surrounding stiffening layer as well as the surrounding housing if the housing deforms or moves due to operation or environmental influences.

[0024] In a further embodiment of the invention, the stiffening layer is multi-layered and composed of different types of plastic. This makes it possible to optimize the mechanical properties for specific requirements, such as flexibility or impact resistance, depending on the position and function of the layer. The layers can be applied in a multi-step injection molding process and can also have different thicknesses and coverage areas on the printed circuit board.

[0025] The method according to the invention comprises the following steps, which are based on the technical specifications of the aforementioned technical objects: First, a printed circuit board is assembled, i.e. provided with the necessary electronic components. This assembled printed circuit board is then inserted into a specially designed injection molding mold. The design of the injection mold allows the printed circuit board to be accommodated at least in sections, creating a free space between the injection mold and the printed circuit board to form the stiffening layer.

[0026] In the next step, at least one molten plastic is injected into the injection mold. The plastic is pressed into shape in the tool and between the printed circuit board and the mold in such a way that it forms a gap-free stiffening layer directly on the printed circuit board. This stiffening layer not only provides mechanical reinforcement, but also protects the electronic components on the printed circuit board.

[0027] Once the plastic has cooled and set, the printed circuit board is removed from the injection mold with the stiffening layer now firmly in place. This combined unit of printed circuit board and stiffening layer is then inserted into a support member. The support member itself is part of the future vehicle door handle and must be precisely aligned with the printed circuit board and the stiffening layer.

[0028] Finally, the support member is inserted into the housing of the vehicle door handle. The housing is designed so that it comprises a grasping portion and a base portion, connected by a curved or angled transition portion. The support member extends at least in sections both in the base portion and in the grasping portion of the housing.

[0029] The injection molding process can also be carried out in several steps, with a sequence of different plastics or even with tool changes and rearrangements of the printed circuit board, if this is necessary to achieve a more complex stiffening geometry or composition.

[0030] The invention will now be explained in more detail with reference to the enclosed figures. Figure 1 shows a side view of a vehicle door handle according to a first embodiment of the invention; Figure 2 shows a perspective view of the vehicle door handle according to the first embodiment; Figure 3 shows an exploded view of the vehicle door handle according to the first embodiment; Figure 4 shows a support member with inserted printed circuit board and stiffening layer according to the first embodiment; Figure 5 shows the components from Figure 4 in a spaced-apart view; Figure 6 shows the printed circuit board with overmolded stiffening layer; Figure 7 shows a section through the printed circuit board with overmolded stiffening layer; Figure 8 shows a sectional view of the vehicle door handle according to the first embodiment;

[0031] Figure 1 shows a vehicle door handle 1 according to a first embodiment of the invention. The vehicle door handle is shown in a side view, i.e. the illustration shows a view of the handle along a direction which, when mounted on a vehicle, corresponds to the direction from the front of the vehicle to the rear along a lateral extension of the vehicle.

[0032] The vehicle door handle has a two-shell housing 2a, 2b forming the outer shell of the vehicle door handle and an actuating device for a user. The two housing shells form the housing 2a, 2b with a base portion 4 extending away from the vehicle, to which the handle portion 3 is formed substantially at right angles. The transition between the base portion 4 and the grasping portion 3 is formed by a curved transition area in the housing 2a, 2b. The dashed line 10 in Figure 1 schematically shows where the outer skin of a vehicle would be located after the vehicle door handle 1 has been installed. A coupling member 7 protrudes from the base portion 4 and is guided through an opening in the vehicle skin 10 into a corresponding coupling device on the inside of the door. The functionality of the coupling member 7 can go beyond the purely mechanical attachment of the vehicle door handle 1 to a vehicle door. For example, the coupling member 7 can trigger emergency unlocking functions when a significant mechanical force is exerted on the vehicle door handle 1. Since this aspect is not essential for the present invention, it will not be discussed further.

[0033] Figure 2 shows the vehicle door handle according to the first embodiment in an inclined perspective view, namely from the perspective of a user approaching a vehicle from diagonally behind. In the perspective shown here, the front of the vehicle is on the left side and the rear of the vehicle is on the right side, so that the vehicle door handle 1 has an oblique silhouette in the direction of the front of the vehicle. A user can reach over the vehicle door handle 1 in its grip area and exert an actuating force on the vehicle door handle 1 to move an unlocked door.

[0034] Figure 3 shows an exploded view in which the housing 2a, 2b is spaced apart from the components accommodated therein. A support member 6 formed from a metal is formed inside the housing 2a, 2b, which extends through the handle portion 3 in accordance with the inner free holder of the housing 2a, 2b and has an angled extension from this through the base portion 4. On the vehicle side, an integrally formed coupling member 7 protrudes from the housing 2a, 2b. A holder 6a is formed in the support member 6, which is designed here as an open bezel. The frame-shaped holder 6a accommodates a printed circuit board 12, which is provided with a plastic material to form a stiffening layer 14 (or stiffening support). This stiffening layer 14 is formed by inserting the assembled printed circuit board 12 into an injection mold and overmolding it with one or more plastics in one or more steps. This creates a connected component in which the stiffening layer 14 made of the plastic extends freely around the printed circuit board 12 in the equipped areas. In this embodiment example, the component thus formed, comprising the printed circuit board 12 and the components arranged thereon as well as the overmolded stiffening layer 14, is inserted into the bezel of the holder 6a. In this embodiment example, the seating can be performed by slightly compressing the stiffening layer 14, i.e. the overmolded plastic, in order to enable a multi-sided abutment of the bezel of the holder 6a against the stiffening layer 14 with the printed circuit board 12 located therein. The printed circuit board 12 is thus gripped in the holder 6a and, together with the support member 6, forms a structural unit that is easy to handle and connect to the housing parts of the housing 2a, 2b. Due to the precise shaping of the stiffening layer 14 in the injection mold, which is adapted in its outer dimensions to the holder 6a, the alignment of the printed circuit board 12 and the components arranged thereon is guaranteed at all times.

[0035] Figure 4 shows the support member 6 with the molded-on coupling member 7 and the holder 6a, which receives the injection-molded circuit board component 12.

[0036] Figure 4 shows in particular that the stiffening layer 14 has recesses 14a which expose parts of the printed circuit board, i.e. in these areas no material is injection-molded onto the printed circuit board or only a very thin film of material. It can be seen that a sensor 16, which can contain both capacitive and inductive components, is arranged in such an exposed area. This enables the detection of a user's operating actions, for example exerting a force on the handle section 3 of the housing part 2a, without a damping effect caused by a superimposed stiffening layer having a detrimental effect.

[0037] Figure 5 shows the overmolded printed circuit board 12 and the surrounding stiffening layer 14 with its recesses 14a and the holder 6a. It can be seen that the design of the holder 6a allows the printed circuit board with the stiffening layer 14 to be inserted, whereby the stiffening layer 14 may have to be slightly compressed. In any case, the holder 6a is adapted in its inner free receiving space to the outer shape of the stiffening layer 14, the shape of which is in turn predetermined by the injection mold into which the printed circuit board 12 is inserted for overmolding.

[0038] Figure 6 shows the overmolded printed circuit board 12 with the stiffening layer 14 and the recesses 14a as well as the sensor component 16.

[0039] Figure 7 shows a sectional view in which the cut has been made between the two recesses 14a shown. It can be seen that the stiffening layer 14 encapsulates the printed circuit board 12 in sections. Depending on the configuration of the printed circuit board, recesses are arranged in the material of the stiffening layer 14 in order to expose components on the printed circuit board 12, in particular the sensor unit 16. It can be seen that the printed circuit board 12 is surrounded at its edges by the material of the stiffening layer 14 without gaps and, in the embodiment shown here, contact surfaces are formed by the stiffening layer 14 for contact with the holder 6a.

[0040] Figure 8 shows a further sectional view in a different plane, with the section this time passing through the recess 14a, in which the sensor arrangement 16 is exposed. In this sectional view, it can be seen from the representation of the housing 2a, 2b how the support member 6 and the composite of the printed circuit board 12 and the stiffening layer 14 extend through the sections of the housing 2a, 2b. The stiffening layer 14 is connected to the printed circuit board 12 without a gap. The composite of printed circuit board 12 and stiffening layer 14 is accommodated in the holder 6a of the support member 6, which extends through the housing 2a, 2b in its angled configuration. A gap can be formed between the housing 2a, 2b and the stiffening layer 14 in order to allow housing deformations without force transmission to the inner structure. In contrast, the housing 2a, 2b can be firmly connected to the base portion in the area of the base portion, for example by screwing, while in the area of the grasping portion, which extends vertically upwards in the illustration, it extends unsupported into the inner free space of the housing 2a, 2b. In this way, on the one hand, it is possible to introduce the mechanical load into the support member in an optimum manner when an operator exerts forces on the outside of the housing 2a, 2b. In addition, the printed circuit board 12, which lies freely in the inner area of the housing 2a, 2b due to the distance from it, can detect movements of the housing 2a, 2b relative to the printed circuit board 12 by means of inductive sensors, provided that corresponding metallic targets are formed on the inside of the housing 2a, 2b for detection by inductive sensors, whereby these inductive sensors can be located on the printed circuit board 12 in exposed areas or also in areas that are covered by the stiffening layer 14.

Claims

1. Vehicle door handle (1) comprising a housing (2a, 2b) having a grasping portion (3) and a base portion (4) wherein the grasping portion (3) is integrally formed with the base portion (4) and extends at an angle therefrom, wherein a support member (6) is received in the housing (2a, 2b), which extends at least in sections both in the base portion (4) and in the grasping portion (3) of the housing (2a, 2b), wherein the support member (6) is fixedly coupled or integrally connected to a coupling member (7), the coupling member (7) extending on one side out of the base portion (4) of the housing (2a, 2b) to allow coupling to a body component (10) of a motor vehicle, characterized in that a holder (6a) for an electronic printed circuit board (12) is formed in the support member (6), wherein the printed circuit board (12) is at least partially overmolded with at least one plastic for stiffening and protection, so that the plastic forms a stiffening layer (14) and the printed circuit board (12) is at least partially covered and connected with a stiffening layer (14), wherein the stiffening layer is applied in direct contact on the printed circuit board.

2. Vehicle door handle according to claim 1, wherein the support member is made of a metallic material and comprises a bezel as a holder of the circuit board, the bezel extending in the grasping portion of the housing.

3. Vehicle door handle according to one of the preceding claims, wherein the overmolded printed circuit board is inserted into the holder of the support member in such a way that at least in sections the stiffening layer is gripped in the holder of the support member.

4. Vehicle door handle according to one of claims 1 to 2, wherein the circuit board arranged in the holder is overmolded together with a part of the support member, so that the stiffening layer at least partially covers both the circuit board and the support member and bonds them to form an assembly.

5. Vehicle door handle according to one of the preceding claims, wherein the circuit board has electrical connections, wherein the contact points of the electrical connections on the circuit board are arranged within the stiffening layer.

6. Vehicle door handle according to any one of the preceding claims, wherein the printed circuit board contains at least one sensor for detecting an operation of the vehicle door handle, wherein the sensor is covered by the stiffening layer for protection.

7. Vehicle door handle according to claim 6, wherein the stiffening layer is thinner in the area where the sensor is covered compared to adjacent areas.

8. Vehicle door handle according to one of the preceding claims, wherein the housing is fixed in the base portion to the support member via connecting means and wherein the support member extends in the grasping portion of the housing at a distance from the housing.

9. Vehicle door handle according to one of the preceding claims, wherein at least one conductor coil with electronic means for forming an inductive sensor is arranged on the circuit board in order to detect a deformation of the housing, wherein at least one metallic target for sensory interaction with the conductor coil is formed in the housing, in particular on the inner wall of the housing and in a section which is positioned opposite the conductor coil.

10. Vehicle door handle according to one of the preceding claims, wherein at least one capacitive sensor with a conductive surface is formed on the printed circuit board in order to detect an approach of an operator to the vehicle door handle.

11. Vehicle door handle according to one of the preceding claims, wherein sensors arranged on the circuit board, in particular capacitive or inductive sensors, are at least partially exposed from the stiffening layer by recesses in the said stiffening layer.

12. Vehicle door handle according to one of the preceding claims, wherein elastic sealing means are arranged at least in sections between the stiffening layer and the housing, which are compressed between the stiffening layer and the housing.

13. Vehicle door handle according to one of the preceding claims, wherein the stiffening layer is formed in several layers at least in sections, wherein the layers differ in the type of plastic.

14. method of manufacturing a vehicle door handle according to one of the preceding claims, comprising the steps of: - mounting a printed circuit board and inserting the mounted printed circuit board into an injection mold, wherein the injection mold is adapted to receive the printed circuit board and to form a free space for holding an injected material around the printed circuit board, - injecting a molten plastic into the injection molding tool so that a stiffening layer is molded onto the printed circuit board between the injection molding tool and the printed circuit board, - removing the printed circuit board with molded-on stiffening layer and inserting the printed circuit board with stiffening layer into a support member, - arranging the support member in a housing, the housing having a grasping portion and a base portion and having a curved or angled transition portion between the grasping portion and the base portion, such that the support member extends at least in sections both in the base portion and in the grasping portion of the housing.

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