wiper arm device

Abstract

The invention relates to a wiper arm device (10), in particular for a motor vehicle, comprising a mounting part (14) attachable to a wiper shaft, a retaining part (12), and a joint part (16) for articulated connection of the mounting part (14) to the retaining part (12). It is proposed that the mounting part (14) and the retaining part (12) be at least partially made of plastic, wherein the joint part (16) comprises at least one joint reinforcement element (20), in particular a metallic joint reinforcement element.

Description

[0001] The invention relates to a wiper arm device, a pre-integrated structural module for a wiper arm device and a method for manufacturing a wiper arm device according to the preamble of the independent claims. State of the art

[0002] Numerous wiper arms for windshield wiper systems of motor vehicles are already known.

[0003] These wiper arms feature a plastic joint that carries a wiper blade at one end. The other end is rotatably connected to a mounting bracket, which transmits the oscillating motion of the wiper shaft to the joint and thus to the wiper blade. This mounting bracket is made of zinc, aluminum, or cast iron. Disclosure of the invention

[0004] The invention relates to a wiper arm device, particularly for a motor vehicle, comprising a mounting part attachable to a wiper shaft, a retaining part, and a joint part for articulated connection of the mounting part to the retaining part. According to the invention, it is proposed that the mounting part and the retaining part be at least partially made of plastic, wherein the joint part comprises at least one joint reinforcement element, in particular a metallic joint reinforcement element.

[0005] The wiper device according to the invention enables a weight reduction of the wiper arm assembly through the use of plastic materials, while the stability and strength of the connection are ensured by the metallic joint reinforcement element. This achieves an optimized balance between lightweight construction and structural integrity, resulting in improved performance and efficiency of the device.

[0006] The measures listed in the dependent claims result in advantageous further developments and improvements of the features given in the independent claims.

[0007] According to an advantageous embodiment of the invention, the joint reinforcement element is designed as a sheet metal element, in particular as a stamped and bent sheet metal part, wherein the joint reinforcement element preferably serves as a load-bearing structural element for the fastening part and the retaining part. This has the advantage of providing increased stability and load-bearing capacity. This structure optimally supports the fastening part and the retaining part and enables a durable and robust connection, which increases the service life and reliability of the wiper arm assembly.

[0008] According to an advantageous embodiment of the invention, the fastening element and / or the retaining element are essentially, preferably entirely, made of plastic, and in particular are designed as injection-molded plastic parts. Designing the fastening element, and alternatively or additionally the retaining element, as injection-molded plastic parts allows for cost-effective and efficient manufacturing, since the use of plastic enables flexible design and easy adaptation of the parts to various requirements. Furthermore, the overall weight of the wiper arm assembly is further reduced.

[0009] According to an advantageous embodiment of the invention, the joint reinforcement element is designed as an insert part that is at least partially overmolded with plastic.

[0010] According to an advantageous embodiment of the invention, the joint reinforcement element has at least one receptacle for a clamping element, in particular a spring element, for articulated clamping between the fastening part and the holding part. The receptacle for a clamping element, in particular a spring element, enables articulated clamping between the parts, which improves the flexibility and adaptability of the wiper arm assembly. Integrating the receptacle into the sheet metal element allows for a particularly stable spring suspension. This ensures reliable operation and optimal contact pressure of the wiper against the windshield under various operating conditions.

[0011] According to an advantageous embodiment of the invention, the joint reinforcement element comprises at least one first wing element and at least one second wing element, wherein the first wing element and the second wing element are articulated, the first wing element being provided for attachment to the fastening part and the second wing element being provided for attachment to the retaining part. The use of wing elements offers improved structural support for the fastening part and the retaining part and a particularly large contact surface, especially for injection molding of the plastic components.

[0012] According to an advantageous embodiment of the invention, the first wing element comprises at least one first coupling element, in particular a molded element, and more preferably a chamfered rib for the fastening part. Alternatively or additionally, according to an advantageous embodiment of the invention, the second wing element comprises at least one second coupling element, in particular a molded element, and more preferably a chamfered rib for the retaining part. The integration of coupling elements as molded elements or chamfered ribs enables a firm and precise connection of the parts and improves the structural integrity and functionality of the wiper arm device, thus increasing its resistance to mechanical stress.

[0013] According to an advantageous embodiment of the invention, the coupling elements are each formed integrally with the wing element, preferably extending at an angle to the wing element. The integral formation of the coupling elements on the wing elements reduces the number of necessary connection points and increases the stability and robustness of the entire wiper arm assembly, thereby reducing assembly errors and simplifying manufacturing. The angled arrangement of the coupling elements relative to the wing element allows for the formation of undercuts that can be particularly well filled by the plastic, thus providing a particularly stable connection.

[0014] According to an advantageous embodiment of the invention, the fastening element in the area of ​​a wiper shaft receptacle for the wiper shaft comprises a metallic reinforcing element, in particular a metallic bushing. The metallic reinforcing element in the area of ​​the wiper shaft receptacle improves the durability and stability of the fastening element at critical points that are subject to high mechanical loads, thereby extending the service life of the wiper arm assembly.

[0015] According to an advantageous embodiment of the invention, the joint reinforcement element and a clamping element clamped in the joint reinforcement element are designed as a pre-integrated structural module, wherein the pre-integrated structural module is preferably designed as a common assembly that can be at least partially overmolded with plastic. The pre-integrated structural module simplifies the manufacturing of the wiper arm device through pre-integration, which reduces manufacturing costs.

[0016] The invention further relates to a pre-integrated structural module for a wiper arm device, comprising at least one joint reinforcement element and at least one clamping element.

[0017] The pre-integrated structural module offers a compact and effective solution for reinforcement and flexible connection within the wiper arm assembly.

[0018] The invention further relates to a method for manufacturing a wiper arm assembly. The method comprises the following steps: inserting the joint reinforcement element, in particular the pre-integrated structural module, into an injection mold and subsequently overmolding the fastening part and / or the retaining part, wherein at least one coupling element is overmolded with plastic. The described manufacturing method enables efficient and cost-effective production of the wiper arm assembly by combining injection molding processes with the integration of reinforcement elements, which ensures greater design flexibility and improved structural integrity of the final products. Drawings

[0019] The drawings schematically illustrate exemplary embodiments of the invention, which are explained in more detail in the following description. They show Fig. 1 a perspective view of an embodiment of a wiper arm device, Fig. 2 perspective views of an embodiment of a joint reinforcement element for a wiper arm device, Fig. 3 a sectional view of an embodiment of a wiper arm device, Fig. 4 a method for manufacturing a wiper arm device according to one embodiment. Description of the exemplary implementations

[0020] In Fig. Figure 1 shows a perspective view of an embodiment of a wiper arm device 10. The wiper arm device 10 comprises a retaining part 12, which receives a wiper rod, a fastening part 14, which is designed to connect the retaining part 12 to a wiper shaft, and a pivot part 16, which pivotally connects the fastening part 14 to the retaining part 12. To connect the retaining part 12 to the wiper shaft, the retaining part 12 has at least one receptacle 21 for the wiper shaft. The location of the attachment point of the wiper shaft on the fastening part 14 is simultaneously a pivot point about which a rotational movement of the wiper arm device 10 is generated.

[0021] A wiper blade (not shown) is attached to the retaining part 12. This blade is designed to wipe a surface on which it rests. The hinge part 16 allows the retaining part 12 to be folded upwards, thus removing the wiper blade from the surface. This device described above is suitable for a windshield wiping system of a motor vehicle, a building, or any other device that includes a surface to be wiped, such as a window or windshield. It is conceivable that the hinge part 20 could be partially formed by components of the mounting part 16 and / or the retaining part 12.

[0022] To reduce costs and weight, according to a preferred embodiment of the invention, both the fastening part 14 and the retaining part 12 are preferably made essentially, preferably completely, of plastic and are preferably manufactured using a plastic injection molding process.

[0023] To provide mechanical stability, the joint part 16 has a joint reinforcement element 20, which is preferably made of metal. The joint reinforcement element 20 is designed as a sheet metal element, preferably as a stamped and bent sheet metal part. This element serves as a load-bearing structural element for the fastening part 14 and the retaining part 12. The joint reinforcement element 20 can be designed as an insert part that is at least partially overmolded with plastic, thereby ensuring a firm connection with the plastic parts. Fig. 1, the joint reinforcement element 20, designed as an insert, is concealed due to the plastic overmolding.

[0024] According to a particularly preferred embodiment of the invention, the fastening part 12 has an additional metallic reinforcing element 34 in the area of ​​the receptacle 21 for the wiper shaft. According to the Fig. In the embodiment of the invention shown in Figure 1, the reinforcing element 34 has the form of a metallic bushing. This reinforcing element 34 serves in particular to provide additional stabilization and to improve the power transmission from the wiper shaft to the wiper arm assembly 10.

[0025] According to a preferred embodiment of the invention, it is conceivable that special measures to reduce the creep behavior of the joint reinforcement element 20 and additionally or alternatively also of the reinforcement element 34 are implemented.

[0026] For example, it is conceivable that the joint reinforcement element 20, and additionally or alternatively the reinforcement element 34, have anchoring elements, which could be located, for instance, at the edges or along the surface of the sheet metal part. It is also conceivable that the joint reinforcement element 20, and additionally or alternatively the reinforcement element 34, have openings or holes. The plastic can then flow advantageously through these openings during the overmolding process and create so-called "sprue heads" on the opposite side, which provide a mechanical interlock. These heads act like rivets and prevent the plastic from shifting relative to the metal. Furthermore, it is also conceivable that the joint reinforcement element 20, and additionally or alternatively the reinforcement element 34, have teeth, hooks, or projections.According to a further advantageous embodiment of the invention, it is also conceivable that the joint reinforcement element 20 and, additionally or alternatively, the reinforcement element 34 may have microstructures on their surface to reduce creep. These microstructures engage with the overmolded plastic and increase friction and the mechanical bond between the metal and the plastic. A targeted increase in surface roughness through microstructures, such as additional embossing or rough areas, can increase the surface area of ​​the sheet metal part, leading to improved mechanical interlocking of the plastic. These microstructures can be created during the manufacturing of the sheet metal part, for example, by punching, laser processing, or sandblasting.

[0027] It is also conceivable that the joint reinforcement element 20 and, additionally or alternatively, the reinforcement element 34 have additional grooves or slots. These grooves or slots can run both longitudinally and transversely to the main load direction and offer resistance to movement and creep of the plastic.

[0028] It is also conceivable that the plastic of the fastening part 14 and, additionally or alternatively, the retaining part 12, is at least partially fiber-reinforced or has additional metallic inserts. Preferably, the fastening part 14 and, additionally or alternatively, the retaining part 12 are made essentially of plastic. Preferably, the fastening part 14 and, additionally or alternatively, the retaining part 12 are made entirely of plastic or fiber-reinforced plastic. Preferably, the plastic is a polymer.

[0029] Fig. Figure 2 shows a perspective view of an embodiment of a joint reinforcement element 20. The joint reinforcement element has a first wing element 26 and a second wing element 28. The wing elements 26 and 28 are pivotally connected to each other so that they can be moved relative to each other. The first wing element 26 is provided for attachment to the mounting part 14, while the second wing element 28 is attached to the retaining part 12.

[0030] According to the in Fig. In the embodiment of the invention shown in Figure 2, the wing elements 26, 28 are each designed as planar, essentially flat structural elements. The joint reinforcement element 20 is designed according to the illustration in Figure 2. Fig. 2. The embodiment of the invention is designed as a one-piece sheet metal part, in particular as a stamped and bent part, and comprises the first wing element 26 and the second wing element 28, which, according to the illustration in Fig. 2. In the embodiment of the invention shown, they together form a gable-like structure.

[0031] The wing elements 26, 28 are arranged and shaped such that, as part of the joint part 16, they enable a hinged connection between the fastening part 12 and the retaining part 14. It is also conceivable that the joint reinforcement element 20 forms the joint part 16, so that the joint function is provided by the joint reinforcement element 20.

[0032] According to the in Fig. In the embodiment of the invention shown in Figure 2, the wing elements 26, 28 are each designed as planar, essentially flat structural elements which are connected at their inner ends along a common joint axis 40 by an integral joint 42, such as a bending zone or fold line.

[0033] The wing elements 26, 28 are preferably designed to be mirror-symmetrical to the imaginary joint plane, which ensures a uniform distribution of the forces occurring on the joint axis 40.

[0034] To optimize creep behavior, it is conceivable that, according to a further possible embodiment of the invention, the wing elements 26, 28 are provided with openings. These openings can be in the form of round, oval, or polygonal shapes, allowing the plastic to flow through the wing elements 26, 28 during the overmolding process. The wing elements 26, 28 can also be provided with special surface structures, such as embossing, grooves, or ribs. These structures increase the surface roughness and enlarge the contact area between the wing elements 26, 28 and the plastic, thus increasing friction and mechanical bonding. Preferably, the embossing is designed as a microstructural pattern that improves the adhesion of the plastic and minimizes the risk of creep.

[0035] To further increase the structural integrity of the wing elements 26, 28 and simultaneously prevent creep of the plastic, reinforcing ribs or flange structures can be provided on the wing elements 26, 28 according to a further embodiment of the invention. Flanges at the edges of the wing elements 26, 28 can be designed to additionally grip the plastic and enable an even firmer embedding.

[0036] Alternatively, the wing elements 26, 28 could be curved or arched to achieve additional three-dimensional deformation resistance. This arching increases stiffness and ensures that the wing elements 26, 28 deform less under load. This curvature can extend along both the longitudinal and transverse directions of the wing elements 26, 28.

[0037] According to a further advantageous embodiment of the invention, it is also conceivable that additional inserts, such as metal inserts, are provided in the wing elements 26, 28. These inserts could, for example, consist of high-strength materials such as titanium or composite materials.

[0038] According to the in Fig. In the embodiment of the invention shown in Figure 2, both the first wing element 26 and the second wing element 28 have at least one coupling element 30, 32 for connection with the respective plastic parts. The first wing element 26 has a first coupling element 30, which is designed as a molded element, preferably as a chamfered rib, for the fastening part 12. The second wing element 28 has a corresponding second coupling element 32 for the retaining part 14. According to the illustration in Figure 2, the first wing element 26 has a first coupling element 30, which is designed as a molded element, preferably as a chamfered rib, for the fastening part 12. The second wing element 28 has a corresponding second coupling element 32 for the retaining part 14. Fig. In the embodiment of the invention shown in Figure 2, coupling elements 30, 32 are each formed integrally on the wing elements 26, 28 and preferably extend at an angle to these, thus forming a corresponding undercut which can be surrounded by plastic.

[0039] According to the in Fig. In the embodiment of the invention shown in Figure 2, the coupling elements 30, 32 are designed as extended tabs or flags that extend over a significant length from the wing elements 26, 28. These extended tabs provide a larger surface area for the plastic, thereby improving the mechanical interlocking. The extended shape increases the contact area through which the plastic can flow around the tabs. The extended tabs can also be bent or angled outwards at their ends to provide additional anchoring points for the plastic.

[0040] According to the in Fig. In the embodiment of the invention shown in Figure 2, the coupling elements 30, 32 each have an opening 34, 36. It is also conceivable that the coupling elements 30, 32 have a plurality of openings. The openings can be designed as openings of different shapes in the coupling element 30, 32. The openings 34, 36 allow the plastic to flow through the coupling elements 30, 32 during the overmolding process, so that the coupling elements 30, 32 can be enclosed by plastic on the opposite side, thereby providing a firm mechanical connection and thus particularly advantageously reducing the risk of creep due to the positive-locking connection between the metal and the plastic.

[0041] According to the in Fig. In the embodiment of the invention shown in Figure 2, the coupling elements 30, 32 each have an arrow-shaped contour at their distal ends 36, 38. This allows the plastic to flow completely around the contour of the coupling elements during the injection molding process and to anchor itself at the acute angles. This arrow-shaped design results in increased resistance to the plastic mass being pulled out or displaced relative to the wing elements 26, 28, which increases the structural stability and strength of the connection and effectively prevents creep. Preferably, the tips of the arrow contour are oriented in the direction of the force flow to further optimize adhesion and structural integration.

[0042] According to the in Fig. In the embodiment of the invention shown in Figure 2, the coupling elements 30, 32 are at least partially curved. It is also conceivable that the coupling elements 30, 32 are formed with multiple curves or folds, for example as S- or Z-shaped elements. These multiple curves increase the complexity of the geometry and provide the plastic with several mechanical anchor points. This design leads to a further increase in friction and mechanical interlocking between the metal and the plastic, thus reducing the risk of creep. The curves can be designed to lie in multiple planes to achieve three-dimensional anchoring.

[0043] According to a further embodiment of the invention, not shown here, it is also conceivable that the coupling elements 30, 32 are provided with hook or barb elements that engage in the plastic and thus reinforce the adhesion. These hooks can be designed in various shapes, such as V-shaped, T-shaped, or L-shaped barbs, which ensure that the plastic remains firmly anchored to the coupling elements 26, 28 under all operating conditions. The barb elements could be arranged along the outer edges of the coupling elements to provide additional security against slippage or migration of the plastic. Additionally or alternatively, the coupling elements 30, 32 could be provided with microstructured surfaces, such as embossing, grooves, or roughness.These microstructures increase the contact area between the coupling elements 30, 32 and the surrounding plastic and increase adhesion through improved mechanical interlocking and friction.

[0044] According to the in Fig. In the embodiment of the invention shown in Figure 2, the coupling elements 30, 32 are integrally formed on opposite side edges S1, S2 of the wing elements 26, 28. This arrangement positions the coupling elements 30, 32 at a maximum distance from each other, so that they completely enclose the intervening plastic components.

[0045] The spacing of the coupling elements 30, 32 along the opposite side edges S1, S2 of the wing elements 26, 28 creates a kind of “frame structure” that efficiently embeds and fixes the plastic components.

[0046] In further embodiments, the coupling elements 30, 32 can be arranged at different positions or at different intervals along the side edges S1, S2 of the wing elements 26, 28 to meet specific mechanical requirements. For example, additional coupling elements could be positioned centrally or at varying intervals along the side edges S1, S2 to optimize the load distribution or to achieve targeted reinforcement in certain areas. This might be particularly necessary in areas with increased bending moment or increased stress. It is also conceivable that the opposite side edge of the same wing element 26, 28 has additional coupling elements.

[0047] According to the in Fig. In the embodiment of the invention shown in Figure 2, the fastening part 14 and the retaining part 12 are injection-molded onto the joint reinforcement element 20, wherein at least the coupling elements 30, 32 are overmolded for connection.

[0048] According to a further embodiment of the invention, however, it is also possible that the fastening part 14 and the retaining part 12 are connected to the joint reinforcement element 20 not by overmolding, but by alternative mechanical connection methods, such as clipping or clamping. In such an embodiment of the invention, the coupling elements 30, 32 can be designed to act as positive-locking clips or clamping elements, enabling quick and easy assembly.

[0049] The coupling elements 30, 32 can, in one embodiment, be designed as spring-loaded clip elements that serve to fix the plastic parts to the joint reinforcement element 20. These clip elements could have hook or tab structures that engage in corresponding receiving openings or grooves in the plastic parts. The advantage of this design lies in the quick and tool-free assembly, whereby the clip elements are reliably held in position by the spring force.

[0050] Alternatively, the coupling elements 30, 32 can also be designed as clamping elements that fix the fastening part 14 and the retaining part 12 to the joint reinforcement element 20 by means of a clamping action. These clamping elements could, for example, comprise spring arms or tapered wedges that provide a secure clamping action when the parts are joined. The clamping could be achieved by the elastic deformation of the clamping elements, so that the plastic parts are held securely on the joint reinforcement element and the connection remains stable even under vibration or mechanical stress.

[0051] Another advantageous embodiment provides a combination of clip and clamping elements, in which the coupling elements 30, 32 comprise both spring-loaded hook structures and curved or spring-loaded clamping surfaces.

[0052] According to a further advantageous embodiment, the coupling elements 30, 32 can also be designed as special positive locking elements, such as teeth, ribbing, or conical projections that engage in corresponding counter-structures of the plastic parts. These geometric features improve both the positive locking and the force transmission between the components, resulting in a particularly stable and resilient connection.

[0053] For the articulated movement and the necessary tension within the joint part 16, the joint reinforcement element 20 has a first receptacle 22 for a clamping element 24. The clamping element 24 is preferably designed as a spring element. The spring element 24 is intended to exert a torque between the fastening part 14 and the retaining part 12 via the joint part 16. The spring element 24 preferably comprises a tension spring, which is optionally extended by a C-bend. The spring element 24 can be a stem-eyelet tension spring, in which case the C-bend can be omitted.

[0054] Preferably, the joint reinforcement element 20 has a second, opposing receptacle 25 (not shown here) for the clamping element 24. Preferably, the clamping element 24 is clamped between the first and second receptacles 22, 25. It is also conceivable that the second receptacle 25 is arranged on another component, such as an additional reinforcement element, of the retaining part 12. The fastening part 14 and the retaining part 12 are connected to each other by the joint part 16 in a hinge-like manner.

[0055] The spring element can, for example, be suspended by a spring in the first receptacle 22 of the first wing element 26. The suspension point is preferably not adjustable.

[0056] Another suspension point is located on the retaining part 12, or on the second wing element 28, where preferably another hook of the spring element is attached. This additional suspension point can preferably be adjusted variably by means of a movable pin or a compensating element.

[0057] The joint reinforcement element 20 and the clamping element 24 can be designed as a pre-integrated structural module 52. This pre-integrated structural module 52 forms a common assembly that can be at least partially overmolded with plastic to simplify manufacturing and increase the stability of the connection.

[0058] According to the in Fig. In the embodiment of the invention shown in Figure 2, the first receptacle 22 is arranged on a lower edge U of the first wing element 26 facing away from the hinge 42. Preferably, the receptacle 22 is formed as a tab integrally connected to the first wing element 26. Preferably, the receptacle 22 is arranged centrally on the lower edge U. Preferably, the tab has a receiving opening 50 for hooking the clamping element 24.

[0059] In Fig. 3 is a section view along a section plane AA according to Fig. Figure 1 shows a section of a wiper arm device 10 according to one embodiment. Since the section plane AA runs centrally through the wiper arm, the following are shown in Fig. 3 the offset coupling elements 30, 32 concealed.

[0060] According to the in Fig. In the embodiment shown in Figure 3, the joint reinforcement element 20 has a joint 42 and two wing elements 26, 28. The first wing element 26 has a first receptacle 22 for the spring element 24, and the second wing element 28 has a second receptacle 25 for the spring element 24. The spring element 24 is clamped between the receptacles 22, 25. The receptacles 22, 25 are integrally formed with the respective wing elements 26, 28. The receptacles 22, 25 and the wing elements 26, 28 are overmolded on one side with the plastic of the fastening part 14 or the retaining part 12, respectively. The joint reinforcement element 20 and the clamping element 24 are preferably designed as a pre-integrated structural assembly 52.

[0061] In Fig.Figure 4 shows a method 100 for manufacturing a wiper arm device 10. In a first process step 110, the joint reinforcement element 20, in particular the pre-integrated module assembly 52, is placed in an injection mold. In a subsequent process step 120, the fastening part 12 and / or the retaining part 14 are injection molded, in particular using a plastic injection molding process. Preferably, at least the coupling elements 30, 32 are overmolded with plastic to ensure a stable connection between the components.

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