SCHOLL WOLFGANG (DE)
WO2014198892A1 | 2014-12-18 |
JPS5663538A | 1981-05-30 | |||
KR200437131Y1 | 2007-11-05 | |||
US20120285992A1 | 2012-11-15 | |||
DE102014118184A1 | 2016-06-09 |
Claims 1. A wiper system (10) for cleaning a vehicle window (1 ), comprising a reservoir (12) for a cleaning fluid (2), comprising a pump (14) for suctioning the cleaning fluid (2) from the reservoir (12), and comprising at least one duct (20) for supplying the cleaning fluid (2) from a delivery side (18) of the pump (14) to a spraying device (32), the spraying device (32) being configured to spray the cleaning fluid (2) onto the vehicle window (1 ) in the wiping area (28, 30) of at least one wiper blade (22, 24), characterized in that an intake side (16) of the pump (14) is connected at least indirectly to a device (40) for supplying air, allowing air to be suctioned by the pump (14) via the intake side (16) of the pump (14) in addition to the cleaning fluid (2) in order to produce a foamy mixture out of the cleaning fluid (2) and the air at the delivery side (18) of the pump (14). 2. The wiper system according to claim 1 , characterized in that the device (40) for supplying air has at least one air intake boring (44; 44a). 3. The wiper system according to claim 2, characterized in that the diameter (d) of the at least one air intake boring (44; 44a) has a diameter (d) that, at atmospheric pressure, prevents cleaning fluid (2) from flowing out of the at least one air intake boring (44; 44a) because of the surface tension of the cleaning fluid (2). 4. The wiper system according to claim 2 or 3, characterized in that the diameter (d) of the at least one air intake boring (44; 44a) is between 0.1 mm and 0.2mm, preferably 0.15mm. 5. The wiper system according to any one of claims 2 to 4, characterized in that the at least one air intake boring (44) is disposed in the area of an intake port (42) of the pump (14), the intake port (42) being connected to the surroundings of the reservoir (12). 6. The wiper system according to any one of claims 2 to 4, characterized in that the at least one air intake boring (44a) is disposed in the area of an air vent (45) within the reservoir (12). 7. The wiper system according to claim 6, characterized in that the mouth of the air vent (45) is located above a level (47) of the cleaning fluid (2). 8. The wiper system according to any one of claims 1 to 7, characterized in that the pump (14) is configured to foam the cleaning fluid (2) together with the air, preferably by means of at least one vane element or the like. 9. The wiper system according to claim 8, characterized in that the pump (14) is a rotary vane pump. 10. The wiper system according to any one of claims 1 to 9, characterized in that the device (40) has an intermediate chamber (62) which has connection with the at least one air intake boring (44; 44a), in that the intermediate chamber (62) is pierced by a drive shaft (52) of the pump (14), the drive shaft (52) reaching a suction chamber (60) for the cleaning fluid (2) and which is there connected with a mixing element (58), especially with a vane wheel, and in that a connection (66) between the intermediate chamber (62) and the suction chamber (60) is generated when turning the drive shaft (52), so that air which is sucked via the intermediate chamber (62) reaches the suction chamber (60). 11. The wiper system according to claim 10, characterized in that the drive shaft (52) has a cross-section reduction (55) in a connection section between the intermediate chamber (62) and the suction chamber (60), especially as at least one flat portion, and in that the drive shaft (52) is surrounded in a radial manner by a sealing element (56) in the area of the cross-section reduction (55), which sealing element (56) is configured to bear against the drive shaft (52) in a sealing manner when the drive shaft (52) is at a standstill and to generate the connection (66) when the drive shaft (52) is turned. 12. The wiper system according to any one of claims 1 to 1 1 , characterized in that the spraying device (32) has at least one spraying nozzle (34) that is integrated in the at least one wiper blade (22, 24). 13. The wiper system according to any one of claims 1 to 1 1 , characterized in that the spraying device (32) has at least one spraying nozzle (36) that is separate from the at least one wiper blade (22, 24). 14. The wiper system according to any one of claims 1 to 13, characterized in that an additional reservoir (50) is provided that serves to store a deicing fluid or a special cleaning agent. 15. A method for operating a wiper system (10) configured according to any one of claims 1 to 14, characterized in that a foaming agent (3) is used additionally to the cleaning fluid (2). |
Prior art
The invention relates to a wiper system for cleaning a vehicle window having the features of the preamble of claim 1 . The invention further relates to a method for operating a wiper system according to the invention.
A wiper system for cleaning a vehicle window having the features of the preamble of claim 1 is known from DE 10 2014 1 18 184 A1 of the applicant. The known wiper system has a spraying device for a cleaning fluid, in which the cleaning fluid is suctioned by means of a (delivery) pump from a reservoir on an intake side of the pump and supplied via a delivery side of the pump and a fluid duct to the at least one spraying device. In order to avoid freezing of the spraying device particularly at low ambient temperatures, the known wiper system additionally has, adjoining the delivery side of the pump, a device for generating an overpressure, by means of which device pressurized air can be fed into the duct serving to supply the cleaning fluid to the spraying device.
The reservoir for the cleaning fluid is customarily arranged in the engine compartment of the motor vehicle and requires a certain installation space. Furthermore, it is customary to store, for example, a quantity of five litres of cleaning fluid in the reservoir so as not to have to constantly replenish it. Automobile manufacturers are therefore seeking possibilities of reducing not only the space requirement for the reservoir but also in particular of reducing the weight or the mass of the cleaning fluid while in practice maintaining an equal overall cleaning action of the cleaning fluid.
Disclosure of the invention The wiper system according to the invention for cleaning a vehicle window having the features of claim 1 has the advantage that it allows a reduction in the volume of the cleaning reservoir and also a reduction in the mass of the cleaning fluid with a similarly long spraying duration or similarly good overall cleaning action of the stored cleaning fluid.
The idea on which the invention is based is not to apply the cleaning fluid to the vehicle window via the spraying device (exclusively) as a liquid, as is customary in the prior art, but in the form of a foam. Here, the foam consists, on the one hand, of the (liquid) cleaning fluid and, on the other hand, of air bubbles. Depending on the type of the cleaning fluid, it may be required here for additional foaming agents or the like to be admixed with the cleaning fluid in order to allow or to improve the foam formation.
In concrete terms, the teaching of the invention according to claim 1 proposes that the wiper system be designed in such a way that an intake side of the pump is connected at least indirectly to a device for supplying air, allowing air to be able to be suctioned by the pump via the intake side of the pump in addition to the cleaning fluid in order to produce a foamy mixture out of the cleaning fluid and the air at the delivery side of the pump. This results in it being able to be supplied to the spraying device in the form of a foam.
Advantageous developments of the wiper system according to the invention for cleaning a vehicle window are stated in the dependent claims. All combinations of at least two features disclosed in the claims, the description and/or the figures fall within the scope of the invention.
In a concrete apparatus-related embodiment of the invention, the device for supplying the air has at least one air intake boring. This air intake boring is connected to the intake side of the pump.
In order to avoid a situation in which, during non-operation of the pump, liquid cleaning fluid is discharged from the air intake boring to the surroundings via the intake side or the air intake boring, there is provision in a development of the last- stated proposal that the diameter of the at least one air intake boring has a diameter that, at atmospheric pressure, prevents cleaning fluid from flowing out of the at least one air intake boring because of the surface tension of the cleaning fluid. In concrete terms, inside diameters of the at least one air intake boring which result here in practice are between 0.1 mm and 0.2mm, preferably approximately 0.15mm.
There are various possibilities with regard to the arrangement of the at least one air intake boring. In a first variant, there is provision that the at least one air intake boring is disposed in the area of an intake port of the pump, the intake port being connected to the external surroundings of the reservoir. Air is thus suctioned from the external surroundings of the reservoir, that is to say from the engine compartment.
In an alternative arrangement of the at least one air intake boring, there is provision that the at least one air intake boring is disposed in the area of an air vent within the reservoir. Such an arrangement particularly has the advantage that an escape of cleaning fluid from the air intake boring is non-critical insofar as the escaping cleaning fluid passes back into the reservoir and is thus not lost.
In order to allow the possibility that, with an air intake boring arranged within the reservoir, no cleaning fluid is suctioned, there is provision in the last-mentioned variant that the mouth of the air vent is located in the reservoir above a level of the cleaning fluid. As a result, in a desired manner, only air can be suctioned from the reservoir.
In order, with the lowest possible apparatus-related outlay, to be able to use the pump to form the cleaning foam from the liquid cleaning fluid together with the suctioned air, there is provision that the pump is configured to foam the cleaning fluid together with the air, preferably by means of at least one vane element or the like. In fully concrete terms, there is provision that the pump is a rotary vane pump. Such a pump customarily makes it possible, with only little additional outlay or modifications, to form the cleaning foam by the required air suctioning.
A further modification of the wiper system relates to the area of the spraying device. This can be designed either in such a way that the spraying device has at least one spraying nozzle that is separate from the at least one wiper blade, or else at least one spraying nozzle that is integrated in the at least one wiper blade. The last-mentioned variant is also designated by the applicant as a so-called “Aqua-Blade wiper blade”.
A further variation of the invention relates to the possibility of using, for certain applications, a cleaning fluid which is provided, for example, in the form of a deicing fluid or a special cleaning agent and which then, depending on the application, can be used in addition to the customarily provided cleaning fluid or else independently thereof. In this case, there can be provision that an additional reservoir with a separate pump is provided, via which pump the special cleaning fluid is supplied to the wiper system or to the spraying device. The design according to the invention of the wiper system with the particularly compact and lightweight reservoir allows such a modification with the additional reservoir and additional pump to be customarily realized in the engine compartment without additionally required weight or installation space by comparison with a conventional wiper system.
Finally, the invention also relates to a method for operating a wiper system according to the invention described so far. The method is distinguished by the fact that use is made of a cleaning fluid which comprises foaming agents. As a result, the formation of the foam can be improved or may be made possible in the first place. In particular, the foamy consistency can thus also be ensured until spraying onto the vehicle window.
Further advantages, features and details of the invention will emerge from the following description of preferred exemplary embodiments and with reference to the drawing. In the drawing:
Figure 1 shows a simplified illustration of a wiper system according to the invention for cleaning a vehicle front window with the use of differently arranged spraying devices,
Figure 2 shows a perspective view of a reservoir for cleaning fluid, provided with a pump, having an intake boring for ambient air,
Figure 3 shows a detail of Figure 2 in an enlarged illustration in the region of the air-suctioning system,
Figure 4 shows a perspective illustration of a modified reservoir for the cleaning fluid in which the air suctioning occurs from a region within the reservoir tank, and
Figure 5 shows a schematic illustration of a modified device for suctioning air by means of a pump.
Identical elements or elements having an identical function are provided with the same reference numbers in the figures.
Figure 1 illustrates in simplified form a wiper system 10 for cleaning a vehicle window 1 , in the exemplary embodiment illustrated a vehicle front window. The wiper system 10 has a reservoir 12 for storing a liquid cleaning fluid 2. Depending on consistency or composition, the cleaning fluid 2 can, where appropriate, additionally comprise a so-called foaming agent 3 in order to form or ensure the formation of (cleaning) foam.
Preferably arranged within the reservoir 12 is a pump 14 for suctioning the cleaning fluid 2 or the foaming agent 3 from the reservoir 12. For this purpose, an intake side 16 of the pump 14 is arranged in operative connection with the cleaning fluid 2 or the foaming agent 3 in the reservoir 12. A delivery side 18 of the pump 14 is connected to a duct 20.
The wiper system 10 additionally comprises by way of example two wiper blades 22, 24 which are interchangeably fastened to wiper arms 26 and which, in a manner known per se, when pivoting back and forth between a lower reversal position UT and an upper reversal position OT, each generate a wiping area in the form of a wiping field 28, 30. In the region of the respective wiping field 28, 30 it is possible, by means of a spraying device 32 which is supplied with cleaning fluid via the duct 20, for the cleaning fluid 2 or the foaming agent 3 to be applied to the vehicle window 1 in the form of a foam via at least one spraying nozzle 34, 36. Here, the spraying nozzle 34, 36 can be arranged for example as a fixedly arranged spraying nozzle 36 in the region of the vehicle body or of the engine bonnet of the vehicle, in which case for example in each case one spraying nozzle 36 is then assigned to one wiping field 28, 30. Alternatively, there can be provision that each wiper blade 22, 24 is assigned, on at least one longitudinal side, a plurality of spraying nozzles 34 which spray the cleaning fluid 2 or the foaming agent 3 in the form of the foam directly ahead of the respective wiper blade 22, 24 onto the vehicle window 1 .
As can be seen in particular from Figures 1 to 3, the intake side 16 of the pump 14 is additionally at least indirectly connected to a device 40 for suctioning air. In the embodiment illustrated in Figures 1 to 3, the device 40 is designed in the form of an air intake port 42 whose air intake boring 44, which opens outside of the reservoir 12, has an (inside) diameter d for suctioning the air of between 0.1 mm and 0.2mm, preferably approximately 0.15mm. Such a design of the device 40 thus makes it possible that air is additionally suctioned via the intake side 1 6 of the pump 14, which air, in particular in conjunction with the foaming agent 3, makes possible the formation of cleaning foam from the cleaning fluid 2 by the pump 14. For this purpose, there is provision in particular that the pump 14 has at least one element, such as a vane element or the like, in order to ensure the corresponding mixture of the air with the cleaning fluid 2 and the foaming agent 3. In particular, there can be provision that the pump 14 is designed in the form of a rotary vane pump. The cleaning fluid supplied to the spraying device 32 thus takes the form of a cleaning foam which consists of the cleaning fluid 2, where appropriate the foaming agent 3 and air bubbles.
Furthermore, there can optionally be provision that the duct 20 is connected to an additional reservoir 50 having an additional pump (not shown in Figure 1 ). In the reservoir 50 there can be arranged, for example, a special deicing agent or another special cleaning fluid.
The device 40 illustrated in Figure 4 differs from the device 40 according to Figures 1 to 3 in that the air intake port 42a with its air intake boring 44a suctions the air from the interior 46 of the reservoir 12 above the level 47 of the cleaning fluid 2 via an air vent 45.
Finally, the device 40 illustrated in Figure 5 displays a pump 14 whose drive shaft 52 has a section 54 with a cross-section reduction in the form of a flat portion 55. In an axial subsection of the flat portion 55, the latter is radially surrounded by a first, elastic sealing element 56. Furthermore, the end of the drive shaft 52 is connected to a mixing element in the form of a vane wheel 58. The vane wheel 58 is arranged in the region of a suction chamber 60 which has connection with the reservoir 12 via the intake side 16. The suction chamber 60 is hydraulically connected to an intermediate chamber 62 via the flat portion 54. The intermediate chamber 62 is sealed with respect to the drive shaft 52 via a further sealing element 64. The intermediate chamber 62 in turn has connection to the air intake boring 44, 44a. If the drive shaft 52 of the pump 14 is not turned, the sealing element 56 also bears against the drive shaft 52 in the region of the flat portion 54, with the result that no connection is formed between the intermediate chamber 52 and the suction chamber 60. By contrast, when the drive shaft 52 is turning, a gap 66 is formed between the flat portion 54 and the sealing element 56, via which gap air suctioned by the air intake boring 44, 44a passes into the suction chamber 60 and is there converted, together with the cleaning fluid 2 suctioned via the intake side 1 6, into foam by the vane wheel 58. This foam is delivered via the delivery side 18 at the suction chamber 60 into the duct 20. The wiper system 10 described so far can be altered or modified in a wide variety of ways without departing from the concept of the invention.
List of reference signs
1 vehicle window
2 cleaning fluid
3 foaming agent
10 wiper system
12 reservoir
14 pump
16 intake side
18 delivery side
20 duct
22 wiper blade
24 wiper blade
26 wiper arm
28 wiping field
30 wiping field
32 spraying device 34, 36 spraying nozzle 40 device
42, 42a air intake port 44, 44a air intake boring
45 air vent
46 interior
47 level
50 reservoir
52 drive shaft
54 section
55 flat portion
56 sealing element 58 vane wheel
60 suction chamber 62 intermediate chamber 64 sealing element 66 gap
d diameter
UT reversal position OT reversal position