WO2017217918A1

WO2017217918A1 - Windshield wiper device

Info

Publication number: WO2017217918A1
Application number: PCT/SE2017/050622
Authority: WO
Inventors: Klaus Schmidt
Original assignee: Scania Cv Ab
Priority date: 2016-06-15
Filing date: 2017-06-12
Publication date: 2017-12-21
Also published as: KR20190006555A; SE1650838A1; SE540687C2; EP3472005A4; CN109311454A; EP3472005A1

Abstract

The invention relates to a windshield wiper device (3), in particular for a motor vehicle (1), comprising a drive unit (29) which is coupled via a transmission device (31) to a wiper shaft (13), having a wiper arm (15) arranged to hold a wiper blade (17), the wiper shaft (13) being arranged so as to rotate about a rotation axis (19), wherein at least the wiper shaft (13) of the wiper device (3) is mounted pivotally about a pivoting axis (27), wherein the rotation axis (19) and the pivoting axis (27) are arranged at an angle to each other. The wiper device (3) further comprises a pivoting motor (21) arranged to pivot at least the wiper shaft (13) of the wiper device (3) about the pivoting axis (27). The invention also relates to a vehicle (1) and a method for wiping a windshield (5).

Description

WINDSHIELD WIPER DEVICE TECHNICAL FIELD

The present invention relates to a windshield wiper device, a vehicle with such a wiper device, and a method for wiping a windshield comprising a curvature.

BACKGROUND AND PRIOR ART

The present invention relates to a windshield wiper device, a vehicle with such a wiper device, and a method for wiping a windshield comprising a curvature according to the appended claims. Vehicles, and in particular heavy goods vehicles, such as trucks and buses, are usually equipped with a windshield in the front regions of said vehicles. The windshield serves to protect the driver and passengers from weather conditions such as rain and wind. As rain, or water from other sources, impair the visibility for the driver, windshield wipers are commonly used to wipe the windshield by means of a wiper blade swiping over the windshield. Windshield wiper devices and systems are known in the art and typically comprise a drive unit coupled to a wiper shaft via a transmission device, wherein the transmission device rotates the wiper shaft back and forth by means of the power provided by the drive unit. The wiper shaft is further equipped with a wiper arm upon which a wiper blade suitable for the particular vehicle can be mounted.

Windshield wiper devices and systems may be designed in several ways depending on the vehicle. Said wiper devices and systems may have one wiper arm and wiper blade swiping over the majority of the windshield, or a plurality of wiper arms and wiper blades, wherein each arm and blade covers separate portions of the windshield. Usually the speed of the movement of the wiper device may be controlled by means of a control unit, which control unit typically has a user interface within reach of the driver operating the vehicle. Wiper devices and systems as described above are well designed to wipe an essentially flat surface with good results. However, as aerodynamics is of great importance for the wind resistance affecting the vehicle when driving, the shape of the windshield may not always be essentially flat in shape. To decrease wind resistance and increase the aerodynamic behaviour of vehicles it is more and more common, for heavy goods vehicles in particular, to design the windshield with a sharper curvature, and/or having curved lateral edges to lower said wind resistance.

This however creates issues for wiping such windshields as the wiper devices and systems cannot handle windshields with too sharp curves. In such circumstances the wiper blades extends past the curvature in an essentially straight direction and thus cannot wipe said curved portion of the windshield.

This is an imperative problem as heavy goods vehicles are not, in some countries, authorized to de driven if large enough portions of the windshield in front of the driver cannot be wiped from water sufficiently.

The document EP 1939054 A2 discloses a windshield wiper device which attempts to alleviate the above described problem. The wiper device according to this document comprises a wiper shaft which is coupled to a drive unit via a transmission device. The drive unit is further mechanically coupled to an actuator which shifts the rotating axis for the wiper shaft by means of mechanically pivot the wiper device when it is operated, wherein the rotation of the wiper shaft automatically pivot the axis of rotation of the wiper shaft to shift the angle of attack of the wiper arm in relation to the windshield. SUMMARY OF THE INVENTION

Despite prior art there is a need to develop a windshield wiper device, which can wipe a windshield having a curvature. Also, there is a need to develop a wiper device, which can be used with high accuracy to guarantee good results to ensure safety when driving a vehicle equipped with such a wiper device. Furthermore, there is a need to develop a windshield wiper device which is customizable for windshields having different designs with different shaped curvatures.

An object of the present invention is thus to provide a windshield wiper device, which can wipe windshield having a curvature with high accuracy. Another object of the invention is to provide a wiper device which is customizable so as to be able to use for windshields having different designs with different shaped curvatures.

The herein mentioned objects are achieved by a windshield wiper device, a vehicle with such a windshield wiper device, and a method for wiping a windshield, which windshield comprises at least one curved portion according to the independent claims.

According to an aspect of the invention the windshield wiper device, in particular for a motor vehicle, comprises a drive unit which is coupled via a transmission device to a wiper shaft, having a wiper arm arranged to hold a wiper blade. The wiper shaft is being arranged so as to rotate about a rotation axis, wherein at least the shaft of the wiper device is mounted pivotally about a pivoting axis. The rotating axis and the pivoting axis are arranged at an angle to each other. The wiper device further comprises a pivoting motor arranged to pivot at least the shaft of the wiper device about the pivoting axis. This has the advantage that the pivoting motor can pivot the wiper shaft in such a way that the wiper arm and thus the wiper blade can be aligned with the curvature of the windshield. This further has the advantage that the pivoting motor can be adjusted for different curvatures or disabled if the wiper device is coupled to a windshield without a curvature present.

According to another aspect of the invention the pivoting motor is a servo motor. This has the advantage that high accuracy is achieved for the pivoting movement of the wiper shaft.

According to yet another aspect of the invention the wiper device further comprises a control unit arranged to control the pivoting of at least the shaft provided by the pivoting motor.

This has the advantage that said pivoting is controlled in a very precise way by means of the control unit. This is advantageous as the control unit is adapted to control the pivoting only and can therefore be designed for this object with high accuracy.

According to a further aspect of the invention the wiper device further comprises a sensor, arranged to determine the position of the wiper arm and provide said position to the control unit.

This has the advantage that the position of the wiper arm, and thus the wiper blade, always is available for the control unit, wherein the control unit therefore can control the pivoting of the wiper shaft in a very precise manner.

According to an even further aspect of the invention the sensor determines the position of the wiper arm by means of determining a rotational position of the wiper shaft. This has the advantage that the sensor is easy to install into the wiper device and that it can be securely attached to the wiper device where it is protected from outer sources such as weather conditions. This further has the advantage that the windshield is not obscured by the need of placing a sensor thereupon, or in the vicinity thereof.

According to an aspect of the invention the pivoting motor pivots the wiper shaft and the transmission device when pivoting is performed. This has the advantage that the transmission device is easier and less expensive to manufacture as only the rotational movement of the wiper shaft needs to be provided by the transmission device. According to another aspect of the invention the pivoting motor further pivots the drive unit when pivoting is performed.

This has the advantage that the wiper device is easy to manufacture as it can be designed and assembled as a whole without adding additional parts to achieve the pivoting of the wiper shaft within the wiper device. This is advantageous as the coupling between the drive unit and the transmission device, and the coupling between the transmission device and the wiper shaft may be designed as a windshield wiper device without the pivoting aspect, but with the possibility to add the pivoting aspect to the wiper device with ease if desired.

According to yet another aspect of the invention a vehicle is provided, which vehicle comprises a windshield wiper device according to the present invention.

This has the advantage that a vehicle with a windshield wiper device which can wipe a windshield having a curvature is provided.

According to a further aspect of the invention a method for wiping a windshield is provided, which windshield comprises at least one curved portion, by using a windshield wiper device comprising a drive unit which is coupled via a transmission device to a wiper shaft, having a wiper arm arranged to hold a wiper blade. The wiper shaft is arranged so as to rotate about a rotation axis, wherein at least the shaft of the wiper device is mounted pivotally about a pivoting axis, wherein the rotating axis and the pivoting axis are arranged at an angle to each other. The method comprising the steps of:

a) rotating the wiper shaft by means of the drive unit and the transmission device so as to generate an angular movement of the wiper arm and the wiper blade, wherein said angular movement of the wiper blade wipes a portion of the windshield, which portion is defined by said angular movement; b) determining if the wiper blade is in the proximity of the at least one curved portion of the windshield; and

c) adjusting the direction of the rotation axis of the wiper shaft by means of a pivoting motor which pivots said rotation axis about the pivoting axis, wherein said pivoting aligns the wiper blade with a curvature of the curved portion of the windshield.

This has the advantage that a method is provided, which method can wipe windshield having a curvature. The pivoting motor can pivot the wiper shaft in such a way that the wiper arm and thus the wiper blade can be aligned with the curvature of the windshield. This further has the advantage that the pivoting motor can be adjusted for different curvatures.

According to an even further aspect of the invention the wiper device of the method further comprises a control unit, which is arranged for calculating a position of the wiper blade during step a), which position is used by the control unit to perform step b), wherein the control unit transmits an output signal to the pivoting motor so as to perform the adjustment of step c) based on the result of step b).

This has the advantage that the control unit can operate the pivoting motor in a very precise and controlled way. This further has the advantage that the control unit may be adapted for windshields with different curvatures, thus making the method customizable without having to mechanically re-design the windshield wiper device being used. According to an aspect of the invention the wiper device of the method further comprises a sensor, which sensor is arranged to determine a rotational position of the wiper shaft, wherein the rotational position of the wiper shaft, in combination with design data for the wiper arm and the wiper blade, is used for calculating the position of the wiper blade.

This has the advantage that the method can use a sensor which is easy to install into the wiper device, and achieve a position of the wiper arm and blade with high accuracy as the angular position of the wiper shaft is easy to determine with such a sensor. According to another aspect of the invention the control unit compares the position of the wiper blade to surface curvature data for the windshield to perform step b). This has the advantage that the control unit at any given time will know if the wiper blade is located near a curvature present in the windshield. As the surface curvature data for the windshield tells the control unit where curvature is present the control unit can easily be adapted to perform step b) knowing the position of the wiper blade. According to yet another aspect of the invention a method for wiping a windshield is provided, wherein the windshield comprises a first essentially flat portion, an intermediate curved portion and a second essentially flat portion, the first and second essentially flat portions being at an angle to each other, wherein the method comprises the steps of: d) wiping the first essentially flat portion in a direction towards the curved portion, by means of performing step a); e) wiping the curved portion in a direction towards the second essentially flat portion, by means of performing step a), b) and c) simultaneously; and f) wiping the second essentially flat portion in a direction away from the curved portion, by means of performing step a) using the adjusted direction of the rotation axis of the wiper shaft of step e).

This has the advantage that the method may be used to wipe a type of windshield which is suitable for heavy goods vehicles, wherein the windshield is adapted for low wind resistance due to the added curvature. The method further has the advantage that the method wipes both the windshield in front of, and on the side towards meeting traffic in relation to the driver driving said vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

Below is a description of, as examples, preferred embodiments of the invention with reference to the enclosed drawings, in which:

Figure 1 schematically illustrates a vehicle provided with a windshield wiper device according to the invention, Figure 2a schematically illustrates a perspective view of a windshield provided with a windshield wiper device according to the invention,

Figure 2b schematically illustrates a top down sectional view of a windshield provided with a windshield wiper device according to the invention,

Figure 3a schematically illustrates a schematically front view of a windshield wiper device with a wiper blade in a first position according to the invention, Figures 3b and 3c schematically illustrate front views of exemplary embodiments of a windshield wiper device with a wiper blade in a second position according to the invention, and

Figures 4a and 4b show flowcharts of a method according to different embodiments for wiping a windshield according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION Figure 1 schematically illustrates a vehicle 1 provided with a windshield wiper device 3 according to the invention. The vehicle 1 comprises a windshield 5 which comprises a front portion 7 and a side portion 9. The windshield further comprises a curved portion 1 1 , which curved portion 1 1 couples the front portion 7 and the side portion 9 to each other. The windshield wiper device 3 comprises a wiper shaft 13, a wiper arm 15 extending from the wiper shaft 13, and a wiper blade 17, detachably coupled to the wiper arm 1 5. The front and the side portion 7, 9 of the windshield 5 of this example are essentially flat surfaces, which essentially flat surfaces are extending in two planes being essentially perpendicular to each other. The curved portion 1 1 comprises a curvature which couples said two essentially perpendicular planes to each other so as to provide a windshield 5 with a curved edge. Thus, the windshield 5 is to be viewed as a one sheet of material covering the front portion 7, the side portion 9, and the intermediate curved portion 1 1 in relation to a driver and/or a passenger within the vehicle 1 . As is known in the art, windshields 5 are commonly provided with curvatures for better aerodynamic behaviour, wherein said curvatures may be oriented in various directions in relation to the area the windshield 5 is meant to cover. For curvatures having large radiuses, in the range of about 1500 mm to about 2000 mm and above, the design of the wiper arms 1 5 and wiper blades 17, being supported with springs and flexible joints, usually provides enough flexibility so as to wipe such curvatures with good results. However, for a windshield 5 such as exemplified in figure 1 or similar, wherein the windshield 5 comprises a curved portion 1 1 provided to bridge a front portion 7 and a side portion 9, the radius of such a curvature is much smaller, typically going down in the region of a few hundred mm. As will be realized, the object of the present invention is to be able to wipe such curvatures with radiuses below the range of about 1500 mm to about 2000 mm, which should be viewed as sharp curvatures. The term curvature used in the patent application should therefore be viewed as a curvature which cannot be wiped by means of a windshield wiper device 3 only relying of the flexibility of the wiper blade 17, and the typically spring loaded mountings of such wiper blades 17.

Figure 2a schematically illustrates a perspective view of a windshield 5 provided with a windshield wiper device 3 according to the invention. The windshield 5 comprises an essentially flat front portion 7, two curved edge portions 1 1 , and two laterally essentially flat side portions 9. The windshield wiper device 3 of this example is schematically illustrated and comprises a wiper shaft 13, arranged to rotate about a rotation axis 19, a wiper arm 15 extending radially from the wiper shaft 13 and extending essentially parallel to the windshield 5. The windshield wiper device 3 further comprises a wiper blade 17, detachably coupled to the wiper arm 1 5 and being arranged to wipe the windshield 5 in a back and forth swiping movement by means of an alternating clockwise and anti-clockwise rotation of the wiper shaft 13 about the rotation axis 19. Said rotation is being provided by a drive unit and transferred to the wiper shaft via a transmission device (the drive unit and the transmission device are not shown in figure 2a). The windshield wiper device 3 further comprises a pivoting motor 21 and a control unit 23. The control unit 23 is in this example arranged in communication with the wiper shaft 13 wherein the control unit 23 receives data for the rotational movement of the wiper shaft 1 3 by means of a sensor 25. The sensor 25 is in this example a sensor arranged on, or in the proximity of, the wiper shaft 13 wherein the sensor 25 can read the rotational displacement, the speed of said rotation and the direction of said rotation of the wiper shaft 13. As the wiper arm 15 holding the wiper blade 17 is attached on the wiper shaft 13, the control unit 23 can thus calculate the position of the wiper blade 17. The control unit 23 further comprises surface curvature data for the windshield 5 to which the windshield wiper device 3 is mounted, wherein said data can be stored in the control unit 23, on a separate memory or in a computer feeding the data to the control unit 23. By means of a computer program P comprising computer code the control unit 23 can then determine if the wiper blade 17 is in proximity of, and moving in a direction towards, a curvature of the windshield 5. When this occurs, the control unit 23 operates the pivoting motor 21 to pivot the rotation axis 19 about a pivoting axis 27 so as to align the wiper blade 17 with the present curvature of the windshield 5, wherein the contact between the wiper blade 17 and the windshield surface area is maximized. As seen in figure 2a, the wiper blade is movable so as to wipe a segment of the essentially flat front portion 7, a segment of one of the curved edge portions 1 1 and one of the laterally essentially flat side portions 9. This is performed by means of pivoting the wiper shaft 13 and thus the rotation axis 19 about the pivoting axis 27. Said pivoting is performed by means of the pivoting motor 21 which is pivotally coupled to the windshield wiper device 3, or parts of said wiper device 3. The pivotal coupling may be arranged to pivot the wiper shaft 13, the wiper shaft 13 and the transmission device, or the wiper shaft 13, the transmission device and the drive unit (the transmission device and the drive unit are not shown in figure 2a). The pivoting motor 21 may be a servo motor, but other types of motors known in the art may also be used. By means of controlling the pivoting of the rotation axis 19, a device is thus provided which can wipe windshields 5 of various designs comprising various curvatures. Further, depending on the need and/or desire regarding how far the wiper blade 17 needs to move in a rotational direction in relation to a driver in a vehicle, the control unit 23 may be programmed to pivot the rotation axis 1 9 to a corresponding desired angle. It is thus easy to modify the windshield wiper device 3 according to the invention to different types of windshields 5 and vehicles, as the pivoting provided by the pivoting motor 21 can be adjusted to different predetermined angles, or even turned off if no curvature is present. Figure 2b schematically illustrates a top down sectional view of a windshield 5 provided with a windshield wiper device 3 according to the invention. The section of the windshield 5 can be viewed as part of the windshield 5 shown in figure 2a. This figure further illustrates how the rotation of the wiper shaft 13 about the rotation axis 1 9 and the pivoting of said rotation axis 1 9 about the pivoting axis 29 provides a wiper device 3 which can wipe a curved portion 1 1 of a windshield 5 as well as the essentially flat front portion 7 in front of the driver, and an essentially flat side portion 9 on the side of the driver. Figure 3a schematically illustrates a schematically front view of a windshield wiper device 3 with a wiper blade 1 7 in a first position Pi according to the invention. The windshield wiper device 3 comprises a drive unit 29 which is coupled via a transmission device 31 to a wiper shaft 1 3, having a wiper arm 1 5 arranged to hold a wiper blade 1 7. The wiper shaft 1 3 is arranged so as to rotate about a rotation axis 1 9, wherein at least the wiper shaft 13 of the wiper device 3 is mounted pivotally about a pivoting axis 27, wherein the rotating axis 1 9 and the pivoting axis 27 are arranged at an angle to each other. In this example, said axles are arranged essentially perpendicular to each other but other angles are also possible. The windshield wiper device 3 comprises first fastening means 33 arranged so as to attach the device to a vehicle, in particular a heavy goods vehicle comprising a windshield with at least one curved portion. The first fastening means 33 are provided with bearing or similar to allow at least the wiper shaft 1 3 of the wiper device 3 to be pivoted about the pivoting axis 27. The wiper device 3 further comprises a pivoting motor 21 arranged to pivot at least the wiper shaft 1 3 of the wiper device 3 about said pivoting axis 27. The pivoting motor 21 may be a servo motor. The pivoting motor 21 is attached to the vehicle by means of second fastening means 35. The pivoting motor 21 further comprises a pivoting shaft 37 which pivots at least the wiper shaft 1 3 of the wiper device 3. Even further, the windshield wiper device 3 comprises a control unit 23, which is arranged in communication with the wiper shaft 1 3 and the pivoting motor 21 , and a sensor 25, arranged to determine the position of the wiper arm 1 5 and provide said position to the control unit 23. The sensor 25 in this example is a sensor 25 which determines the position of the wiper arm 1 5 by means of determining a rotational position of the wiper shaft 1 3, being arranged in proximity to the wiper shaft 1 3. The control unit 23 comprises a computer, or a link to a computer, comprising a computer program P with programme code for receiving the data containing the current position of the wiper arm 15 to calculate the position of the wiper blade 17 in relation to the windshield of a vehicle. The control unit 23 further comprises stored data in a memory M, or a link to readable data, containing the design parameters of the windshield to control the pivoting of the rotation axis 19 when the wiper blade 17 is moved towards a curvature in the windshield.

As is illustrated in figure 3a, a rotation of the wiper shaft 13 rotates the wiper arm 15 holding the wiper blade 17 about the rotation axis 19. This is illustrated by the wiper arm 15 and wiper blade 1 7 in a first position Pi , and the wiper arm 15' and wiper blade 17' drawn with dotted lines being in an angled position P_a in relation to the first position Pi . Said rotation is used to wipe essentially flat portions of a windshield of a vehicle on which the windshield wiper device 3 is arranged.

Figures 3b and 3c schematically illustrate front views of exemplary embodiments of a windshield wiper device 3 with a wiper blade 1 7 in a second position P2 according to the invention. Figure 3b schematically illustrates a front view of an exemplary embodiment of a windshield wiper device 3 with a wiper blade 1 7 in a second position P2 according to the invention. In this exemplary embodiment the pivoting motor 21 has pivoted the wiper shaft 13 and the transmission device 31 about the pivoting axis 27 to a position which is perpendicular to the position of the wiper shaft 13 and transmission device 31 seen in figure 3a. This in turn moves the rotation axis 1 9 of the wiper shaft 13 to a direction which extends in a direction perpendicular to the rotation axis 1 9 seen in figure 3a. Hence, a windshield wiper device 3 is provided which can wipe

windshields having a curvature as the wiper blade 17 can be pivoted about a pivoting axis 27, which pivoting aligns the wiper blade 17 with a curved portion of the windshield as well as a side portion if present. This can be applied to wipe

windshields with essentially flat portions coupled with an intermediate curved portion, wherein the windshield wiper device is mounted in such a way that the pivoting aligns the wiper blade 17 with said curvature. It may also further be applied to wipe windshields having one essentially flat portion and one curved portion, wherein the pivoting pivots the rotation axis 1 9 to align the wiper blade 17 with the curvature during the wiping procedure. The control unit 23 comprising a computer program P with program code can thus control the pivoting motor 21 so as to be adapted to an existing curvature in a windshield to which the windshield wiper device 3 is mounted. The example seen in figure 3a pivots both the wiper shaft 13 and the transmission device 31 which makes manufacturing of the wiper shaft 1 3 and the transmission device 31 easy as the rotation of the wiper shaft 1 3 within the transmission device 31 only needs to be designed for a rotational movement of the wiper shaft 1 3 within the transmission device 31 . That means mechanically simple bearings can be used for said rotation which provides a precise rotational movement with good results but still being cost effective and easy to manufacture. The wiper shaft 1 3 can thus be mounted to the transmission device 31 by means of single axis rotational bearings, and the transmission device 31 can also be mounted to the drive unit 29 by means of single axis rotational bearings. This allows for a simple design as bearings allowing for a three dimensional movements are not needed.

Figure 3c schematically illustrates a front view of an exemplary embodiment of a windshield wiper device 3 with a wiper blade 1 7 in a second position P2 according to the invention. This exemplary embodiment is similar to that of figure 3b, but differs in that the pivoting of the rotation axis 19 is performed by pivoting the wiper shaft 13, the transmission device 31 and the drive unit 29. This provides an embodiment of a windshield wiper device 3 which can be assembled as a whole without the pivoting function, but then add said pivoting function by means a hinged mounting of the wiper device 3 to a vehicle and the addition of a pivoting motor 21 rotationally coupled to the windshield wiper device 3. This in turn leads to a very customizable windshield wiper device 3 where the pivoting function may be optional at a later stage of the assembly of said wiper device 3 to a specific vehicle. This ensures a cost effective manufacturing process wherein windshield wiper devices 3 can be manufactured for vehicles having essential flat windshields as well as windshield comprising curved portions in the same process line.

Figure 4a shows a flowchart of a method according to a first embodiment for wiping a windshield comprising a curvature according to the invention. The windshield wiper device 3 and the windshield 5 may according to this embodiment be viewed as described in accordance with figure 2a. The method is performed by means of using a windshield wiper device 3 comprising a drive unit 29 which is coupled via a transmission device 31 to a wiper shaft 13, having a wiper arm 1 5 arranged to hold a wiper blade 17, the wiper shaft 13 being arranged so as to rotate about a rotation axis 19, wherein at least the wiper shaft 13 of the wiper device 3 is mounted pivotally about a pivoting axis 27, wherein the rotating axis 19 and the pivoting axis 27 are arranged at an angle to each other. The method comprises the steps of a) rotating the wiper shaft 1 3 by means of the drive unit 29 and the transmission device 31 so as to generate an angular movement of the wiper arm 15 holding the wiper blade 17, wherein said angular movement wipes a portion of the windshield 5 with the wiper blade 17, which portion is defined by said angular movement. Further, the method comprises the steps of b) determining if the wiper blade 17 is in the proximity or in the area of a curved portion 1 1 of the windshield 5, and c) adjusting the direction of the rotation axis 19 of the wiper shaft 13 by means of a pivoting motor 21 which pivots said rotation axis 19 about a pivoting axis 27, wherein said pivoting aligns the wiper blade 17 with a curvature of the curved portion 1 1 of the windshield 5. Steps a) and b) are simultaneously performed by means of a control unit 23 which operates step b) and c). Step a) is continuously performed by means of the drive unit 29 of the wiper device 3, wherein a sensor 25 provides the control 23 unit with data regarding the position of the wiper blade 17 in relation to the surface area of the windshield 5 underneath, and in proximity of the position of the wiper blade 17. By means of determining the direction and speed of the wiper blade 17 during step a), and comparing said variables with surface area design data of the windshield 5, the control unit 23 can determine if a pivoting of the rotation axis 19 of the wiper device 3 is needed by means of a computer program P and operate the pivoting motor 21 accordingly. This means that step a) is continuously performed as long as the drive unit 29 provides power to the transmission device 31 , and that step b)

simultaneously is performed by means of the input data from step a) which is being fed into the control unit 23. Based on the results of step b), the control unit 23 performs step c) if a curvature is present in relation to the movement of the wiper blade 17.

This provided a method for wiping windshields 5 comprising curvatures wherein the method can wipe several types of curvatures without the need to mechanically redesign the windshield wiper device 3. For example, if a windshield 5 consists of a curved portion 1 1 only, the steps a), b) and c) are all performed simultaneously so as to constantly adjust the rotation axis 19 of the wiper shaft 1 3 while the wiper blade 17 is moved back and forth over said curved portion 1 1 .

Figure 4b shows a flowchart of a method according to a second embodiment for wiping a windshield 5 comprising a first essentially flat portion 7 and a second essentially flat portion 9, coupled with an intermediate curved portion 1 1 . This embodiment may be as described in accordance with figure 2a and 2b, wherein the first essentially flat portion 7 may be a portion covering a front view for a driver driving a vehicle, and the second essentially flat portion 9 may be a portion covering a side view of a driver driving the vehicle, but other similar arrangements are also possible. In the example described herein, the windshield wiper device 3 can be arranged to perform the method according to the invention by the steps of d), e) and f), wherein step d) comprises wiping the first essentially flat portion 7 in a direction towards the curved portion 1 1 , by means of performing step a). The step e) then comprises wiping the curved portion 1 1 in a direction towards the second essentially flat portion 9, by means of performing step a), b) and c) simultaneously. Step f) further comprises wiping the second essentially flat portion 9 in a direction away from the curved portion 1 1 , by means of performing step a) using the adjusted direction of the rotation axis 19 of the wiper shaft 13 of step e). Hence all three portions 7, 1 1 , 9 of the windshield 5 are wiped in a correct and precise manner by means of the method of the invention. Due to the pivoting of the rotation axis 19 being performed and adjusted by means of a separate control unit 23, the wiper device 3 and the method according to the invention may easily be adjusted to work on different types of windshields 5 and in various different ways. Different modes of operation are easily obtainable by changing mode and/or programing of the control unit 23. The wiper device 3 and method can for example be set to primarily wipe an essentially flat portion 7 of a windshield 5 and periodically wipe a curved portion 1 1 as well, or to wipe one portion, being either essentially flat or curved, exclusively. The wiper device 3 and method may further also be set to wipe a plurality of essentially flat and curved portions 7, 9, 1 1 together in one stroke of the wiper blade 17 by means of a clockwise rotation and then wipe the same area of the windshield 5 in a single stroke by means of a following anti-clockwise rotation. Or as another example, the wiper device 3 and method may be set to first wipe one portion of the windshield 5 by means of the back and forth rotation of the wiper shaft 13, and then pivot the rotation axis 27 to wipe a second portion of the windshield. Hence, a versatile wiper device 3 and method for wiping windshields 5 are provided, wherein the wiper device 3 and method can be customized for several types of windshields 5 and different types of needs, the different types of need being based on, for example, different weather conditions.

As should be realized, the components and features specified above may within the framework of the invention be combined between the different embodiments specified.

Claims

1 . A windshield wiper device, in particular for a motor vehicle (1 ), comprising a drive unit (29) which is coupled via a transmission device (31 ) to a wiper shaft (1 3), having a wiper arm (1 5) arranged to hold a wiper blade (1 7), the wiper shaft (13) being arranged so as to rotate about a rotation axis (19), wherein at least the wiper shaft (13) of the wiper device (3) is mounted pivotally about a pivoting axis (27), wherein the rotation axis (19) and the pivoting axis (27) are arranged at an angle to each other,

characterized in that

the wiper device (3) further comprises a pivoting motor (21 ) arranged to pivot at least the wiper shaft (1 3) of the wiper device (3) about the pivoting axis (27).

2. The wiper device according to claim 1 , wherein the pivoting motor (21 ) is a servo motor.

3. The wiper device according to any of the preceding claims, wherein the wiper device (3) further comprises a control unit (23) arranged to control the pivoting of at least the wiper shaft (1 3) provided by the pivoting motor (21 ).

4. The wiper device according to claim 3, wherein the wiper device (3) further comprises a sensor (25), arranged to determine the position of the wiper arm (15) and provide said position to the control unit (23).

5. The wiper device according to claim 4, wherein the sensor (25) determines the position of the wiper arm (15) by means of determining a rotational position of the wiper shaft (13).

6. The wiper device according to any of the preceding claims, wherein the

pivoting motor (21 ) pivots the wiper shaft (13) and the transmission device (31 ) when pivoting is performed.

7. The wiper device according to claim 6, wherein the pivoting motor (21 ) further pivots the drive unit (29) when pivoting is performed.

8. A vehicle (1 ), characterized in that the vehicle (1 ) comprises a windshield wiper device (3) according to any of the preceding claims.

9. A method for wiping a windshield (5), provided with at least one curved

portion (1 1 ), by using a windshield wiper device (3) comprising a drive unit (29) which is coupled via a transmission device (31 ) to a wiper shaft (13), having a wiper arm (15) arranged to hold a wiper blade (17), the wiper shaft

(13) being arranged so as to rotate about a rotation axis (1 9), wherein at least the wiper shaft (13) of the wiper device (3) is mounted pivotally about a pivoting axis (27), wherein the rotating axis (19) and the pivoting axis (27) are arranged at an angle to each other, comprising the steps of:

a) rotating the wiper shaft (13) by means of the drive unit (29) and the transmission device (31 ) so as to generate an angular movement of the wiper arm (15) and the wiper blade (1 7), wherein said angular movement of the wiper blade (17) wipes a portion of the windshield (5), which portion is defined by said angular movement,

characterized in that the method further comprises the steps of:

b) determining if the wiper blade (17) is in the proximity of the at least one curved portion (1 1 ) of the windshield (5); and

c) adjusting the direction of the rotation axis (19) of the wiper shaft (13) by means of a pivoting motor (21 ) which pivots said rotation axis (1 9) about the pivoting axis (27), wherein said pivoting aligns the wiper blade (1 7) with a curvature of the curved portion (1 1 ) of the windshield (5).

10. The method according to claim 9, wherein the wiper device (3) further

comprises a control unit (23), which is arranged for calculating a position of the wiper blade (1 7) during step a), which position is used by the control unit

(23) to perform step b), wherein the control unit (23) transmits an output signal to the pivoting motor (21 ) so as to perform the adjustment of step c) based on the result of step b).

1 1 . The method according to claim 10, wherein the wiper device (3) further comprises a sensor (25), which sensor (25) is arranged to determine a rotational position of the wiper shaft (13), wherein the rotational position of the wiper shaft (1 3), in combination with design data for the wiper arm (15) and the wiper blade (1 7), is used for calculating the position of the wiper blade (1 7).

12. The method according to any one of claims 10 and 1 1 , wherein the control unit (23) compares the position of the wiper blade (1 7) to surface curvature data for the windshield (5) to perform step b).

13. The method according to any of claims 9 to 12, wherein the windshield (5) comprises a first essentially flat portion (7), an intermediate curved portion (1 1 ) and a second essentially flat portion (9), the first and second essentially flat portions (7, 9) being at an angle to each other, wherein the method comprises the steps of:

d) wiping the first essentially flat portion (7) in a direction towards the curved portion (1 1 ), by means of performing step a);

e) wiping the curved portion (1 1 ) in a direction towards the second essentially flat portion (9), by means of performing step a), b) and c) simultaneously; and f) wiping the second essentially flat portion (9) in a direction away from the curved portion (1 1 ), by means of performing step a) using the adjusted direction of the rotation axis (19) of the wiper shaft (13) of step e).

14. A computer program (P), wherein said computer program (P) comprises

programme code for causing a control unit (23) or a computer connected to the control unit (23) to perform the steps according to any of the claims 9-13.

15. A computer programme product comprising a programme code stored on a computer-readable medium for performing the method steps according to any of claims 9-13, when said computer programme (P) is run on a control unit (23) or a computer connected to the control unit (23).