Wiper arm and wiper mechanism

Abstract

A wiper arm, particularly suitable for windshields of motor vehicles with large angles of curvature, is described, wherein the wiper arm comprises a support arm and a mounting arm, the support arm having a free end and being pivotally connected to the mounting arm at a second end, and wherein the wiper arm can be connected to a wiper shaft via the mounting arm in such a way that a rotational movement of the wiper shaft about a first axis of rotation x can be transmitted to the wiper arm. The mounting arm comprises at least a lower extension and an upper extension. Furthermore, a wiping device, particularly suitable for windshields of motor vehicles with large angles of curvature, is disclosed, comprising at least a wiper arm that can be pivotally driven via a wiper shaft.

Description

[0001] The invention relates to a wiper arm, in particular for a motor vehicle with the features of claim 1 and a wiping device, in particular for a motor vehicle with the features of claim 11. State of the art

[0002] Wiping devices with at least one wiper arm serve to maintain a clear view when the windshield of a motor vehicle is exposed to substances that impair visibility, particularly in the case of precipitation-related obstructions. These devices typically comprise a wiper arm, which can be set into a pivoting or oscillating motion via a wiper shaft, and a wiper blade. The wiper blade is driven by the wiper arm, one end of which is connected to a mounting arm coupled to the wiper shaft, while the other, free end of the wiper arm carries the wiper blade. A variety of different devices are known for the oscillating drive of the wiper shaft, which differ, among other things, in complexity and installation space requirements.The wiper arm is set into a pivoting motion by alternating rotary movements of the wiper shaft, whereby the wiper blade attached to the wiper arm follows this pivoting motion and wipes the windshield of a motor vehicle in a known manner. Various designs are also known for the connection between the wiper blade and the wiper arm, in which either the wiper blade is pivotally attached to the wiper arm or the wiper arm carries a wiper blade that is pre-tensioned in the direction of the windshield.

[0003] For example, German patent DE 197 47 797 A1 discloses a wiping system for straight to slightly curved windshields of motor vehicles, in which the pivoting movement of the wiper arm can be converted into a relative movement of the wiper blade, resulting in an increase in the wiping area while maintaining the same pivoting range. However, a problem arises here as well: especially with strongly curved windshields, a wiper joint is needed that optimally adapts the wiper lip to each wiping angle position of the windshield curvature in order to achieve the required angle of attack of the wiper blade to the windshield. Therefore, the requirements for cleaning such strongly curved windshields cannot be met with known wiper device concepts.Conventional wiper joints, in particular, pose a problem for windows that wrap around the vehicle occupants and have correspondingly large curvature angles, due to their rigid connection, which ensures precise adherence to the wiping angles.

[0004] The invention is based on the objective of providing a wiper arm and a wiping device for a motor vehicle which makes it possible to clean complex windows with large angles of curvature using the simplest possible means and which are as simple in design as possible, easy to assemble and cost-effective.

[0005] This problem is solved by a wiper arm and a wiping device with a wiper arm for a motor vehicle, comprising the features of the independent claims. Advantageous embodiments, variants, and further developments of the invention are described in the dependent claims. Disclosure of the invention

[0006] A wiper arm according to the invention, which is particularly suitable for windshields of motor vehicles with large angles of curvature, comprises a support arm and a mounting arm, wherein the support arm has a free end and is pivotally connected to the mounting arm at a second end, and wherein the wiper arm is furthermore connected to a wiper shaft via the mounting arm in such a way that a rotational movement of the wiper shaft about a first axis of rotation x can be transmitted to the wiper arm. Because the mounting arm comprises at least a lower extension and an upper extension, it is possible for the lower extension and the upper extension to rotate relative to each other as a result of the rotation, such that an increase in the wiping area can be achieved while maintaining a nearly constant swivel range. Furthermore, this solution is characterized by a simple and compact design.Furthermore, the free end of the support arm is designed in such a way that it can be connected to a wiper blade.

[0007] The upper arm is connected at one end to the wiper shaft, so that the rotational movement of the wiper shaft can be transmitted via the upper arm to the wiper arm. The lower arm and the upper arm interact via at least one drive element such that a rotational movement of the wiper shaft about the first axis of rotation x is transmitted via the upper arm to the lower arm in such a way that the lower arm rotates about a free second axis of rotation y. The disc defines an upper disc edge plane c, with the second axis of rotation y being perpendicular to the disc edge plane c.

[0008] The first axis of rotation x is tilted relative to the second axis of rotation y such that the second axis of rotation y forms an acute angle α with the first axis of rotation x, where an angle is defined below the acute angle α which is α ≤ 90°.

[0009] Preferably, the driver is rigidly connected to the lower arm. In an advantageous embodiment, the lower arm is divided into a first region which is perpendicular to the axis of rotation y and thus parallel to the disk plane z, and a second region which is tilted relative to the second axis of rotation y such that the second axis of rotation y forms an acute angle β with the second region.

[0010] In a further embodiment, the support arm is pivotally attached to the upper boom by a first joint whose axis of rotation is essentially perpendicular to the first axis of rotation x. It is particularly advantageous if the support arm is U-shaped, at least in the region of its second end, and has two legs, thus forming a type of fork joint. The first joint is preferably connected to the support arm by means of a pivot pin, and the pivot pin extends through both legs of the second end. This ensures high stability, and such a pivotal connection between the support arm and the mounting arm can be implemented particularly simply and therefore cost-effectively during manufacturing, assembly, and disassembly. Furthermore, this design allows the mounting arm to be attached to the support arm in such a way that the support arm can be folded against the windshield of the vehicle.

[0011] Advantageously, a spring element is provided between the support arm and the mounting arm. This spring element comprises a tension spring that is stressed during relative movement between the support arm and the mounting arm. The primary purpose of the spring element is to press the wiper blade, attached to the free end of the support arm, against the vehicle's windshield, thereby generating the necessary contact force for the wiper blade. The tension spring is connected to the mounting arm by a fastener, which is typically designed as a bracket. The tension spring is hooked into the bracket on one side, and the bracket is hooked onto the mounting arm on the other.

[0012] In a further embodiment, the upper arm has a first section and a second section, the second section being engaged with the drive element in such a way that a rotational movement of the wiper shaft about the first axis of rotation x is transmitted via the upper arm to the lower arm. To ensure this is as free of play as possible, the second section has flanks or side elements that enclose the drive element.

[0013] Furthermore, it is also possible that the first section and the second section of the upper boom are connected to each other via the first joint, so that in a particularly preferred embodiment the second section of the upper boom is arranged to be displaceable in such a way that the second section can perform a relative movement with respect to the driver, wherein the relative movement takes place in the longitudinal direction of the second section.

[0014] According to a further preferred embodiment of the invention, the support arm is connected to the upper extension of the mounting arm via the first joint. In this way, both the support arm and the mounting arm, as well as the upper extension and the lower extension, are connected via the first joint, thus eliminating the need for an additional mounting point and allowing the mounting of the support arm to be adapted variably and flexibly to the design of the wiper arm.

[0015] Advantageously, the upper arm is connected to the wiper shaft in a rotationally fixed manner via a second joint whose axis of rotation is essentially perpendicular to the first axis of rotation x. It is particularly advantageous if the second joint is also designed as a clevis joint with a pivot pin, thus ensuring high stability and particularly simple and cost-effective manufacturing, assembly, and disassembly.

[0016] According to a preferred embodiment of the invention, the driver has a spherically curved surface, so that it can be ensured that the second section of the upper cantilever surrounds the driver largely without friction, so that ideal guidance of the driver between the two side elements, or between the two flanks of the second section, can be ensured.

[0017] The present invention further relates to a wiping device, in particular for windshields of motor vehicles with large angles of curvature, which has a wiper arm according to the invention.

[0018] Further features, applications, and advantages of the invention will become apparent from the following description of the exemplary embodiment of the invention, which is illustrated in the drawing. It should be noted that the features described or illustrated in the figures, individually or in any combination, have only a descriptive character regarding the subject matter of the invention, irrespective of their inclusion in the claims or their cross-references, and irrespective of their formulation or representation in the description or in the drawing, and are not intended to limit the invention in any way. Drawings

[0019] An embodiment of the invention will now be explained in more detail with reference to the embodiments shown in the drawings. The drawings show: Fig. 1 a schematic perspective view of a wiping device according to the invention with a wiper arm; Fig. 2 a schematic perspective arrangement of a lower extension of a wiper arm according to the invention to a wiper shaft of a wiper device according to the invention Fig. 1; Fig. 3 the arrangement of an upper boom in the schematic perspective arrangement of the wiping device Fig. 2; Fig. 4 a schematic perspective side view of a wiping device according to the invention Fig. 1 in the front area of ​​a windshield of a motor vehicle; Fig. 5 a schematic perspective side view of the wiping device according to the invention Fig. 1 in the side area of ​​a window of a motor vehicle; and Fig. 6 a schematic perspective top view of the wiping device according to the invention Fig. 1 in the front area of ​​a motor vehicle window.

[0020] In Fig. Figure 1 shows a perspective view of a wiping device 100 according to the invention. This device essentially comprises a wiper arm 110 according to the invention, which can be pivotally driven about a first axis of rotation x via a wiper shaft 125. The wiper arm 110 consists of a support arm 112 and a mounting arm 114, both of which are generally made of sheet metal as stamped and bent parts.

[0021] The support arm 112 is essentially elongated and has a hook-shaped bend at a first, free end 116 of its longitudinal extent, to which a wiper blade in contact with a disc can be pivotally attached. At its other, second end 117 of its longitudinal extent, the support arm 112 is pivotally connected to the mounting arm 114 via a first joint 120, a fork joint with a pivot pin 130, the axis of rotation of which is essentially perpendicular to the first axis of rotation x, so that the support arm 112 is foldable with respect to the mounting arm 114 in a first axis a.

[0022] The support arm 112 is essentially U-shaped in the region of the first joint 120 and surrounds the mounting arm 114 in the region of its first end 118 with lateral flanks 150. The first joint 120 is essentially formed by a joint bolt 130 that extends through the support arm 112 and the mounting arm 114. To ensure that the free end 116 of the support arm 112 is pressed against the disc during operation, a spring, which is not shown here for clarity, can be tensioned between the mounting arm 114 and the support arm 112. For this purpose, the spring can, for example, be hooked at one end into a tab bent outward from the support arm 112 and at the other end into a C-shaped bracket, which in turn is hooked into a crossbar that extends through the mounting arm 112.

[0023] The mounting arm 114 is also essentially elongated and has a first end 118 along its longitudinal extent, at which it is connected to the support arm 112 by the first joint 120. At the other, second end 122 of the mounting arm 114, a second joint 124 is provided, which serves to attach the wiper arm 110 to the wiper shaft 125 of the wiping device 100. The wiper arm 110 is thus connected to the wiper shaft 125 in such a way that a rotational movement of the wiper shaft 125 about the first axis of rotation x can be transmitted to the wiper arm 110. Thus, during operation, the wiper shaft 125 performs a rotary back-and-forth movement about the first axis of rotation x, causing the wiper arm 110 to oscillate.

[0024] The mounting arm 114 has an upper extension 160 and a lower extension 170, the upper extension 160 and the lower extension 170 interacting via a driver 180 such that a rotational movement of the wiper shaft 125 about the first axis of rotation x is transmitted via the upper extension 160 to the lower extension 170, causing the lower extension 170 to rotate about a free second axis of rotation y. It can be clearly seen in the figure that the first axis of rotation x is tilted relative to the second axis of rotation y, so that the second axis of rotation y forms an acute angle α with the first axis of rotation x, where the acute angle α is understood to be an angle that is 0 < α < 90°.

[0025] As in the Fig. Figure 2, a schematic perspective arrangement of the lower boom 170 of the mounting arm 114, shows that the lower boom 170 comprises a first section 172, which is perpendicular to the second axis of rotation y and as shown in the Fig. 4, Fig. 5 and Fig. 6. The first section 174 pivots about the first axis of rotation x and parallel to a disk plane z, and a second section 174 is tilted relative to the second axis of rotation y such that the second axis of rotation y forms an acute angle β with the second section 174, where the angle β is defined below the acute angle β, which is less than 90°. The lower arm 170 is connected to the upper arm 160 only on one side and via the driver 180 and is not rotationally fixed to the wiper shaft 125. The driver 180 is fixedly connected to this second section 174 and, in the illustrated embodiment, has a spherically curved surface.

[0026] As in the Fig. Figure 3, a schematic perspective view of the upper boom 160 and the lower boom 170 of the mounting arm 114, shows in more detail that the upper boom 160 comprises a first section 162 and a second section 164 and is rotationally fixed to the wiper shaft 125 via the first section 162. The connection to the wiper shaft 125 is made via the second joint 124, the axis of rotation of which is essentially perpendicular to the first axis of rotation x. The first section 162 and the second section 164 of the upper boom 160 are connected to each other via the first joint 120. This connection allows the second section 164 of the upper boom 160 to be displaceably moved relative to the driver 180 on the lower boom 170, with the relative movement occurring in the longitudinal direction of the second section 164.

[0027] The Fig. 4 and Fig. Figures 5 each represent a schematic perspective view of the wiping device 100 according to the invention, wherein the wiper arm 110 is in Fig. 4 in the front area of ​​a windscreen 190 of a motor vehicle and in Fig. 5 is located in the side area of ​​the windshield of the motor vehicle 190. The windshield 190 defines an upper edge plane c. These two perspective views clearly show that the wiper arm 110 is driven by the wiper shaft 125 so that it pivots about the first axis of rotation x. The first axis of rotation x is tilted relative to the second free axis of rotation y, such that the second axis of rotation y forms an acute angle α with the first axis of rotation x. Furthermore, it is clearly visible that the first section 172 of the lower extension 170 runs parallel to the windshield plane z and is perpendicular to the second axis of rotation y.

[0028] The wiper arm 110 is guided by the wiper shaft 125 into a pivoting movement over the disc 190. During this movement, a wiper blade (not shown) sweeps across a wiped area on the disc 190. A rotational movement of the wiper shaft 125 about the first axis of rotation x causes the mounting arm 114, which is fixed to the wiper shaft 125, to move along with it. Due to the curved shape of the disc 190, the wiper arm 110 undergoes a lifting movement about the first joint 120 and the second joint 124, the respective axes of rotation of which are essentially perpendicular to the first axis of rotation x.

[0029] Due to the lifting movement and the way in which the first section 162 and the second section 164 of the upper boom 160 are connected to each other via the first joint 120, the second section 164 of the upper boom 160 shifts such that a relative movement in the longitudinal direction of the second section 174 occurs with respect to the driver 180 on the lower boom 170. Furthermore, as a result of the rotation and the lifting movement, the upper boom 160 and the lower boom 170 of the mounting arm 114 rotate relative to each other.

[0030] It becomes clear that, particularly in the central position of the wiper shaft 125 above the disc 190 as shown in the exemplary embodiment, an increase in the wiping area can be achieved by using a wiper arm 110 according to the invention.

[0031] Furthermore, the design of the wiper arm 110 according to the invention ensures that the wiping movement is possible with uniform contact pressure of the wiper blade on the disc even when the disc 190 is as described in the Fig. 4, Fig. 5 and Fig. Figure 6 shows a strong, irregular curvature along the wiper path.

[0032] In addition to the embodiment described and illustrated, further embodiments are conceivable, which may include further modifications and combinations of features. The description of the figures serves only to illustrate the invention.

Claims

[1] Wiper arm (110), especially suitable for windscreens (190) of motor vehicles with large angles of curvature, wherein the wiper arm (110) has a support arm (112) and a mounting arm (114), wherein the support arm (112) has a free end (116) and is pivotally connected to the mounting arm (114) at a second end (117), and wherein the wiper arm (110) can be connected to a wiper shaft (125) via the mounting arm (114) in such a way as to prevent rotation, such that a rotational movement of the wiper shaft (125) about a first axis of rotation (x) can be transmitted to the wiper arm (110), wherein the mounting arm (114) comprises at least a lower extension (170) and an upper extension (160), wherein the upper extension (160) is connected at a first end (118) to the wiper shaft (125), characterized by , that the lower arm (170) and the upper arm (160) interact via at least one driver (180) in such a way that a rotational movement of the wiper shaft (125) about the first axis of rotation (x) is transmitted via the upper arm (160) to the lower arm (170) in such a way that the lower arm (170) rotates about a free second axis of rotation (y), and the first axis of rotation (x) is tilted relative to the second free axis of rotation (y) in such a way that the second axis of rotation y forms an acute angle (α) with the first axis of rotation (x). [2] Wiper arm (110) according to claim 1, characterized by , that the driver (180) is firmly connected to the lower boom (170). [3] Wiper arm (110) according to one of claims 1 or 2, characterized by , that the second axis of rotation (y) is perpendicular to a disk edge plane (c). [4] Wiper arm (110) according to one of claims 1 to 3, characterized by, that the support arm (112) is pivotally attached to the upper boom (160) by a first joint (120) whose axis of rotation is essentially perpendicular to the first axis of rotation (x). [5] Wiper arm (110) according to one of claims 1 to 4, characterized by , that the upper arm (160) has a first section (162) and a second section (164), wherein the second section (164) engages with the driver (180) in such a way that a rotational movement of the wiper shaft (125) about the axis of rotation (y) is transmitted via the upper arm (160) to the lower arm (170). [6] Wiper arm (110) according to claim 5, characterized by , that the first section (162) and the second section (164) of the upper boom (160) are connected to each other via the first joint (120). [7] Wiper arm (110) according to claim 5 or 6, characterized by, that the second section (164) of the upper boom (160) is arranged to be displaceable in such a way that the second section (164) can perform a relative movement with respect to the driver (180). [8] Wiper arm (110) according to one of claims 6 or 7, characterized by , that the support arm (112) is connected to the upper boom (160) via the first joint (120). [9] Wiper arm (110) according to any one of claims 1 to 8, characterized by , that the upper arm (160) is connected to the wiper shaft (125) via a second joint (124) whose axis of rotation is essentially perpendicular to the first axis of rotation (x). [10] Wiper arm (110) according to any one of claims 1 to 9, characterized by , that the driver (180) has a spherically curved surface. [11] Wiping device (100), particularly suitable for windscreens (190) of motor vehicles with large angles of curvature, comprising at least a wiper arm (110) pivotably driven via a wiper shaft (125) according to one of claims 1 to 10, wherein the wiper arm (110) can be connected to a wiper blade.

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