DEVICE FOR SUPPLYING AIR TO A SUCTION SIDE OF A PUMP, COMPONENT UNIT HAVING SUCH A DEVICE AND WIPER SYSTEM

Abstract

The invention relates to a device (50) for supplying air to a suction side (12) of a pump (10) of a wiper system (100), said device (50) comprising a suction channel (60) for sucking in air, said suction channel (60) being able to be connected to the suction side (12) of the pump (10). Provision is made that the device (50) is realized as a component separate from the pump (10) and comprises a connection area (52) for connecting the device (50) with a supply container (14) for washer fluid (3) and having an additional connection area (54) for a suction nozzle (24) of the pump (10), and that a check valve (62) is disposed in the suction channel (60), said check valve (62) being designed to open and close as a function of a negative pressure (P) on a suction nozzle (24) of the pump (10), whereby when the said check valve (62) is opened air can enter the area of the suction nozzle (24) of the pump (10), and when the check valve (62) is closed no air is sucked in. 20

Claims

1. A device for supplying air to a suction side of a pump of a wiper system, said device comprising: a suctioning channel for suctioning air, said suctioning channel being able to be connected to the suction side of the pump, wherein the device is realized as a component separate from the pump; a connection area for connecting the device with a supply container for washer fluid; and an additional connection area for a suction nozzle of the pump, wherein a check valve is disposed in the suctioning channel, said check valve being realized for opening and closing as a function of a negative pressure on a suction nozzle of the pump, whereby when the said check valve is opened air enters the area of the suction nozzle of the pump, and when the check valve is closed no air is sucked.

2. The device according to claim 1, wherein the suctioning channel comprises a first section in which the check valve is arranged, wherein the first section is connected with a second section which forms a part of the additional connection area for the suction nozzle of the pump.

3. The device according to claim 2, wherein the second section is realized for radially surrounding the suction nozzle of the pump by forming a supply gap which is connected with the suction side of the pump.

4. The device according to claim 1, wherein in the additional connection area an element is arranged, said element comprising a crosssectional constriction which acts as throttle for the washer fluid.

5. The device according to claim 4, wherein the element is sleeve-shaped and is arranged in the additional connection area in a sealing manner.

6. The device according to claim 1, wherein the check valve is designed as a duckbill-valve.

7. The device according to claim 1, wherein the device has a basic body which is made of plastic and realized as an injection moulded part.

8. The device according to claim 1, wherein a filter element is disposed on the side of the check valve facing away from the suctioning channel.

9. A component unit, comprising: a pump for suctioning washer fluid from a supply container said pump comprising a suction nozzle; and a device, which serves for supplying air and is realized according to claim 1, said suction nozzle of the pump protruding into the additional connection area of the device.

10. A component unit, comprising: a supply container for washer; and a device according to claim 1, which serves for supplying air, an opening of the supply container surrounding the connection area of the device in a sealing manner.

11. A wiper system for cleaning a vehicle, comprising: a supply container for a washer fluid; a pump for suctioning the Washer fluid from the supply container; and at least one duct for supplying a cleaning medium from a pressure side of the pump to a spraying device which is realized for spraying the cleaning medium onto the vehicle window in the wiping area of at least one wiper blade, and a suctioning side of the pump being at least indirectly connected to a device to supply air, in addition to the washer fluid, so that air is suctioned from the pump via the suction side of the pump order to produce a foam-like cleaning medium from the washer fluid and air at the pressure side, wherein the device for supplying air comprises a check valve which is realized for opening and closing as a function of a negative pressure on the suction side of the pump, whereby when the check valve is opened air can enter the area of the suction nozzle of the pump, and when the check valve is closed no air is sucked.

12. The wiper system according to claim 11, wherein the pump is realized for foaming the washer fluid together with the suctioned air, preferably via at least one vane element or the like.

13. The wiper system according to claim 11, wherein the pump is realized as a vane pump.

14. The wiper system according to claim 10, wherein the spraying device comprises at least one spray nozzle integrated in the at least one wiper blade.

15. The wiper system according to claim 10, wherein the spraying device comprises at least one spraying nozzle which is separate from the at least one wiper blade.

Description

[0020] Further advantages, features and details of the invention can be gathered from the following description of preferred exemplary embodiments and by using the drawings, in which:

[0021] FIG. 1 shows a simplified illustration of a wiper system for cleaning a vehicle front window,

[0022] FIG. 2 shows a schematic illustration of a component unit, comprising a supply container for cleaning medium and a device for supplying air,

[0023] FIG. 3 shows a component unit modified with respect to FIG. 2, comprising a pump and a device for supplying air connected to the suction nozzle of the pump,

[0024] FIG. 4 shows a sub-area of the component unit according to FIG. 3 in a longitudinal section, and

[0025] FIG. 5 shows a flowchart to illustrate the action of sucking in air by means of a device according to the invention for supplying air.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0026] The same elements or elements having the same function are provided with the same reference numbers in the figures.

[0027] In FIG. 1, the important component parts of a wiper system 100 for cleaning a vehicle window 1, a vehicle front window in the exemplary embodiment, are illustrated. The wiper system 100 comprises, by way of example, two wiper arms 102, 103 with wiper blades 105, 106 fixed replaceably thereto, which can be pivoted to and fro between the lower reversal position UT and an upper reversal position OT by means of a drive (windscreen wiper motor), not shown, in order to clean the vehicle window 1.

[0028] To apply a cleaning medium 2 in the form of a cleaning foam to the vehicle window 1, each of the two wiper blades 105, 106 has, by way of example, multiple spray nozzles 108 thereon spaced apart from one another in the longitudinal direction. As an alternative thereto, provision can also be made for each of the two wiper blades 105, 106 to be assigned a spray nozzle 109 arranged in a fixed location. The spray nozzles 108 and 109 thus each form a spraying device 110.

[0029] The cleaning medium 2 is supplied to the spray nozzles 108 and 109 by means of at least one hydraulic duct in the form of a hose 5, which is connected to a pressure side 8 of a pump 10. Via its suction side 12, the pump 10 sucks in liquid washer fluid 3 stored in a supply container 14, it being possible for additives, in particular foaming agents, to be added to the washer fluid 3. The pump 10 is formed as a vane cell pump and, for this purpose, has at least one vane (not illustrated) rotatably arranged in the pump 10. The pressure side 8 of the pump 10, designed in the form of a pressure nozzle, is located on the side of the pump 10, preferably just above the suction side 12. In addition, the pump 10 has a connecting plug 9, merely illustrated symbolically.

[0030] Various arrangements of the pump 10 with the supply container 14 will be explained below by using FIGS. 2 and 3. FIG. 2 illustrates a component unit 20, which comprises the supply container 14 and a device 50 for supplying air from the suction side 12 of the pump 10. To this end, the supply container 14 has in one wall an opening 22, into which the device 50 protrudes, the device 50 being sealed off relative to the opening 22. The component unit 20 can be completed by connecting the pump 10 to the device 50 to form a functioning installation unit for a vehicle. It is important that the device 50 is formed as a component which is separate from the pump 10.

[0031] FIG. 3 shows a component unit 30 that is modified with respect to FIG. 2 comprising the device 50 for supplying air to the suction side 12 of the pump 10 in addition to the pump 10. On its outer circumference, the device 50 has a connection area 52, which is designed to be inserted into the opening 22 of the supply container 14, forming a sealing connection, in order as a result to complete a functioning installation unit for a vehicle. Here, too, the device 50 is formed as a component which is separate from the pump 10.

[0032] FIG. 4 shows the area of the device 50 and the end of the pump 10 that faces the device 50 in the component unit 30 in an enlarged illustration. In particular, it can be seen that the device 50 has a basic body 51 consisting of rubber material or of a thermoplastic elastomer such as Santopren with an additional connection area 54 designed in the form of a passage opening, into which the suction side 12 of the pump 10 protrudes with a suction nozzle 24. In the longitudinal direction of the suction nozzle 24, in the additional connection area 54, there follows a sleeve-shaped element 56, which is formed as an injection moulded part made of plastic and which rests in a sealing manner with its outer circumference on the wall of the additional connection area 54 of the device 50. The sleeve-shaped element 56 has a passage opening in the form of a cross-sectional constriction 58, via which the washer fluid 3 reaches the suction side 12 of the pump 10. From a fluidic point of view, the cross-sectional constriction 58 thus forms a throttle for the washer fluid 3.

[0033] The device 50 has a suction channel 60 for supplying air to the suction side 12 of the pump 10. The suction channel 60 has a first section 61, which runs at right angles to the suction nozzle 24 of the pump 10 and is arranged close to the pump housing 26 of the pump 10. Arranged within the first section 61 is a substantially at least partially conical check valve 62, which is designed in the form of a so-called duckbill valve, which permits air from the surroundings to be sucked into the suction channel 60. In order to avoid sucking foreign bodies or dirt into the suction channel 60 via the check valve 62, the suction area of the check valve 62 is additionally covered by a filter element 65 on the side of the check valve 62 that faces away from the suction side 12.

[0034] The first section 61 is connected to a second section 66 of the suction channel 60, which in turn is connected to the suction side 12 of the pump 10. The second section is, by way of example, designed in the form of a longitudinal groove 68 in the additional connection area 54 of the device 50, which area is arranged on the side of the suction nozzle 24 that is opposite the check valve 62. The second section 66 intersects the first section of the suction channel 60 in the longitudinal direction of the additional connection area 54 and, as a result, is connected to the first section 61. The second section 62 ends just underneath the suction nozzle 24 but in front of the sleeve-shaped element 56, so that air sucked in via the suction channel 60 can enter the suction nozzle 24 directly.

[0035] When the check valve 62 is open, (ambient) air passes via the suction channel 60 into the area of the suction side 12 or of the suction nozzle 24 of the pump 10, the pump simultaneously sucking in washer fluid 3 from the supply container 14 via the sleeve-shaped element 56 together with the air. The washer fluid 3, together with the air, passes from the suction side 12 of the pump 10 to the pressure side 8 of the latter, thorough mixing and swirling of the washer fluid 3 with the air being carried out by the aforementioned vane element of the pump 10, as a result of which foaming is carried out in the desired manner. Foam-like cleaning medium 2 under pressure is thus present on the pressure side 8 of the pump 10, in order to be conveyed to the spray nozzles 108, 109.

[0036] During the operation of the pump 10, in which in particular its vane element is rotated continuously, the check valve 62 is opened and closed cyclically as a function of the pressure P.sub.1 prevailing on the suction side 12 and the suction channel 16, and the ambient pressure P.sub.2 prevailing outside the check valve 62 and the device 50, and on the basis of the forces generated by the pressures P.sub.1 and P.sub.2. If the pump 10 is switched on, then the pressure P.sub.1 on the suction side 12 and the suction channel 60 initially falls abruptly as compared with the pressure P.sub.2. This effects an opening of the check valve 62, so that ambient air passes via the suction channel 60 to the suction side 12 or the suction nozzle 24. This in turn effects a reduction in the pressure P.sub.1 as compared with the switching on, until the pressure difference that is still present between P.sub.1 and P.sub.2 is overcompensated, so that the check valve 62 closes. This in turn effects an abrupt pressure reduction on the suction side 12, i.e. in turn a reduction in the pressure P.sub.1 in such a way that the check valve 62 opens again. This relationship between the cyclic opening and closing of the check valve 62 and thus the cyclic suction of ambient air in the direction of the suction side 12 of the pump is illustrated in FIG. 5. The cyclic opening and closing of the check valve 62 (value A) over the time t is illustrated. In the example illustrated, the cycle ratio relating to the example is 1:4, i.e. the check valve 62 is open during 25% of the operation of the pump 10.

[0037] The wiper device 100 and the device 50 described to this extent can be modified in multifarious ways without departing from the ideas of the invention. It is important to the invention that the device 50 is formed as a component which is separate from the pump 10 and the supply container 14, the device 50 being arranged as an intermediate element between the supply container 14 and the pump 10.

LIST OF REFERENCE SYMBOLS

[0038] 1 Vehicle window

[0039] 2 Cleaning medium

[0040] 3 Washer fluid

[0041] 5 Duct

[0042] 8 Pressure side

[0043] 9 Connecting plug

[0044] 10 Pump

[0045] 12 Suction side

[0046] 14 Supply container

[0047] 16 Vane

[0048] 20 Component unit

[0049] 22 Opening

[0050] 24 Suction nozzle

[0051] 26 Pump housing

[0052] 30 Component unit

[0053] 50 Device for supplying air

[0054] 51 Basic body

[0055] 52 Connection area

[0056] 54 Additional connection area

[0057] 56 Sleeve-shaped element

[0058] 58 Cross-sectional constriction

[0059] 60 Suction channel

[0060] 61 First section

[0061] 62 Check valve

[0062] 65 Filter element

[0063] 66 Second section

[0064] 68 Longitudinal groove

[0065] 100 Wiper system

[0066] 102 Wiper arm

[0067] 103 Wiper arm

[0068] 105 Wiper blade

[0069] 106 Wiper blade

[0070] 108 Spray nozzle

[0071] 109 Spray nozzle

[0072] 110 Spraying device

[0073] UT Lower reversal position

[0074] OT Upper reversal position

[0075] P.sub.1 Pressure

[0076] P.sub.2 Ambient pressure