Sensor cleaning device, pneumatic system, vehicle and method for operating sensor cleaning device

Abstract

The invention relates to a sensor cleaning device (100) for a vehicle (1000), the sensor cleaning device (100) being designed to clean at least one sensor surface (301) of a sensor (300), the sensor cleaning device having: a compressed air inlet (270), which is designed to receive compressed air (DL), a liquid inlet (680), which is designed to receive a liquid (F), -a cleaning interface (310) configured for providing a liquid (F) and / or compressed air (DL). According to the invention, a delivery volume region (11) is provided in the sensor cleaning device (100), which delivery volume region is designed to accommodate a liquid (F) and is connected in a fluid-conducting manner to the compressed air inlet (270), the liquid inlet (680) and the cleaning connection (310) in such a way that the compressed air inlet (270), the liquid inlet (680) and the cleaning connection (310) are connected in a fluid-conducting manner. The liquid (F) is conveyed to the cleaning connection (310) in a conveying direction (FR) by applying compressed air (DL) to the compressed air inlet (270), the conveying volume region (110) being designed such that the compressed air (DL) is in, in particular, direct and / or phase-boundary pressure-transmitting contact with the liquid (F) in order to convey the liquid (F).

Description

Technical Field

[0001] The invention relates to a sensor cleaning device according to the preamble of claim 1. The invention also relates to a pneumatic system, a vehicle and a method for operating a sensor cleaning device. Background Art

[0002] Sensor cleaning devices for vehicles are known. With the aid of sensor cleaning devices, surfaces on the vehicle, in particular sensor surfaces of sensors, can be cleaned by means of at least one cleaning fluid, in particular a liquid and / or compressed air.

[0003] In this case, by means of, in particular, regular cleaning of the sensor surfaces on the vehicle, it is possible to reduce the contamination of the sensors and thus to make them function more reliably. Clean sensor surfaces thus advantageously increase the reliability of driver assistance functions and / or partially automated and / or automated driving functions of the vehicle. The safety of the vehicle, its occupants and other road users is thus advantageously increased by the sensor cleaning device.

[0004] There are already sensor cleaning devices that are advantageous in principle. Thus, DE 11 2017 006 621 T5 describes a vehicle cleaning system for cleaning an object to be cleaned, wherein the vehicle cleaning system is provided with a tank for containing a cleaning liquid, a pump for pressurizing and conveying the cleaning liquid in the interior of the tank, a high-pressure air generating unit for generating high-pressure air, a first spray opening for spraying the cleaning liquid in the direction of a cleaning surface of the object to be cleaned, a second spray opening for spraying the high-pressure air in the direction of the cleaning surface, and a control unit and a vehicle control ECU for controlling the spraying of the cleaning liquid and the high-pressure air; and the control unit and the vehicle control ECU perform control so that after the spraying of the cleaning liquid from the first spray opening is started, the spraying of the high-pressure air from the second spray opening is started.

[0005] DE 103 32 939 B4 also describes a device for cleaning a front area in front of a distance sensor installed in a vehicle, in particular a commercial vehicle, wherein the front area can be supplied with compressed air provided via a line from at least one compressed air source located in the vehicle, wherein the compressed air supply quantity is controlled during operation of the vehicle as a function of specific time intervals.

[0006] DE 10 2018 126 091 A1 describes a sensor cleaning device for selectively applying a first medium to a surface, the sensor cleaning device comprising: a high-pressure reservoir configured to store a first medium at a storage pressure; a pulse nozzle configured to apply the first medium at the storage pressure to the surface in a pulsed manner; a switching valve, the switching valve having a nozzle interface and a high-pressure reservoir interface configured to selectively establish a first connection between the high-pressure reservoir and the pulse nozzle, and a feed interface for establishing a second connection between the high-pressure reservoir and a first medium source. In the sensor cleaning device described there, it is provided that the high-pressure reservoir and the switching valve are structurally integrated in a reservoir valve module, wherein the switching valve is configured as an electromagnetic switching valve to connect between the first connection and the second connection when the high-pressure reservoir interface is at the storage pressure.

[0007] DE 10 2019 125 970 A1 describes a sensor cleaning system for cleaning a sensor, in which a switching unit is set up to enable the sensor to be cleaned via at least one nozzle line with a cleaning liquid discharged from at least one nozzle and / or a cleaning gas discharged from at least one nozzle. Here, the switching unit plays a central role here, and the switching unit includes a switching valve that can be controlled by a control unit. One embodiment provides that the gas storage is arranged in one container and the liquid storage is arranged in another container. A storage line is arranged between the two containers, which connects the two containers to each other. Here, it is advantageous to have an additional switching unit between the containers. A more compact embodiment of the sensor cleaning system can be achieved by accommodating the cleaning liquid and the cleaning gas in a common container. The cleaning liquid and the cleaning gas are directly adjacent to each other here. Here, when the cleaning gas, especially located above the cleaning liquid, is compressed, the cleaning liquid is simultaneously loaded with pressure by means of the cleaning gas, so that both the cleaning liquid and the cleaning gas are finally in a pressure-loaded state. Therefore, the switching unit between the liquid storage and the gas storage can be omitted. However, in order to fill the cleaning liquid in a pressure-free state, the container must be vented beforehand. This is why the container of DE 10 2019 125 970 A1 is constructed as a reservoir for storing cleaning liquid and cleaning gas, respectively.

[0008] Although these solutions are advantageous in principle, sensor cleaning devices are still worth improving, especially with regard to sensor cleaning that is as simple as possible and / or energy-efficient and effective.

[0009] It would therefore be desirable to have improvements in sensor cleaning devices, particularly with respect to reducing infrastructure costs and / or efficiently utilizing energy and / or cleaning fluids. Summary of the invention

[0010] The present invention is based on this and has the object of providing an improved device and an improved method which in particular allow a simplified structure and / or an improved efficiency with respect to the required cleaning fluid and / or the required energy. In particular, a sensor cleaning device, a pneumatic system, a vehicle and a method for operating a sensor cleaning device which are improved in this respect should be provided.

[0011] The object with regard to the sensor cleaning device is achieved by the invention in a first aspect with a sensor cleaning device according to claim 1 .

[0012] The present invention is based on a sensor cleaning device for a vehicle, which is configured to clean at least one sensor surface of a sensor, wherein the sensor cleaning device has: a compressed air input end configured to receive compressed air; a liquid input end configured to receive liquid; and a cleaning interface configured to provide liquid and / or compressed air.

[0013] According to the invention, a delivery volume region is provided in the sensor cleaning device, which delivery volume region is designed to accommodate a liquid.

[0014] The delivery volume region is connected to the compressed air inlet, the liquid inlet and the cleaning connection in a fluid-conducting manner. In particular, the delivery volume region is formed as a part of the pneumatic connection.

[0015] The delivery volume area is connected to a compressed air inlet, a liquid inlet and a clean interface in a fluid-conducting manner in such a way that the liquid is delivered in a delivery direction to the clean interface by applying compressed air to the compressed air inlet, wherein the delivery volume area is designed so that the compressed air and the liquid are in, in particular, direct and / or phase-boundary pressure-transmitting contact for conveying the liquid.

[0016] In this respect, the pressure-transmitting contact can usually also be realized via a pneumatic device or a pneumatic actuator, which can preferably be a non-return valve, for example.

[0017] However, in terms of direct pressure-transmitting contact with the liquid, it is preferred that the liquid and the compressed air are in close contact; for example, this can preferably be a membrane between the liquid and the compressed air.

[0018] In a particularly preferred embodiment, the pressure-transmitting contact of the compressed air with the liquid is a phase-boundary contact with the liquid, that is, a situation in which the compressed air and the liquid touch each other directly without any separating elements in between. In this respect, this embodiment also establishes direct and phase-boundary pressure-transmitting contact.

[0019] The invention is based on the recognition that cleaning with liquids is advantageous in principle, since dirt can be softened and washed away in this way. The invention also includes the recognition that a simple design of the sensor cleaning device is advantageous, since this can save costs and weight in the vehicle. In particular, additional pumps or similar devices for conveying liquids lead to increased costs, weight and installation space, and to increased complexity and maintenance of the sensor cleaning device.

[0020] The present invention surprisingly found that a pump or similar conveying means for conveying the liquid for cleaning can be omitted if a conveying volume region is used which is designed for direct pressure-transmitting contact of compressed air with the liquid for conveying the liquid.

[0021] This means that the delivery volume region is designed in such a way that the compressed air provided to the compressed air inlet can come into contact with the liquid and can therefore transmit a pressure, in particular a delivery pressure, to the liquid.

[0022] In particular, therefore, only a compressed air source and a liquid tank are required to operate such a sensor cleaning device; the delivery volume region is preferably and advantageously formed distally from the storage region, downstream of the pneumatic partitioning means at the liquid inlet.

[0023] In particular, it may be sufficient to provide the liquid from a liquid tank without pressure or guided by gravity, since the actual delivery process to the cleaning interface or the sensor surface to be cleaned takes place by applying compressed air in the delivery volume area. The delivery direction is guided from the liquid inlet through the delivery volume area to the cleaning interface.

[0024] Advantageous developments of the invention are apparent from the dependent claims and specify advantageous possibilities for realizing the above-described concept within the scope of the object and with further advantages.

[0025] In the context of a preferred development, it is provided that the liquid inlet and / or the compressed air inlet and / or the cleaning connection is arranged at or in the delivery volume region, preferably on the container wall. In other developments, the liquid inlet and / or the compressed air inlet and / or the cleaning connection can be connected to the delivery volume region in a fluid-conducting manner via a hose, a pipe or the like. The delivery volume region itself is formed, so to speak, as part of the pneumatic connection and in this sense is also designed in a fluid-conducting manner according to the concept of the invention.

[0026] It is preferably provided that the delivery volume region is designed to accommodate a delivery quantity of liquid, wherein the delivery quantity is delivered in a delivery direction to the cleaning connection by applying compressed air to the compressed air inlet.

[0027] It has proven to be particularly advantageous if a pneumatic partitioning device is arranged at the liquid inlet of the delivery volume region. It is particularly advantageous if the pneumatic partitioning device is designed relatively simply as an inlet nonreturn valve. The pneumatic partitioning device is particularly designed to open in the delivery direction and to block against the delivery direction. Preferably, the sensor cleaning device comprises an inlet nonreturn valve arranged at the liquid inlet, which inlet nonreturn valve opens in the delivery direction and blocks against the delivery direction.

[0028] It has also proven to be advantageous if the delivery volume region is pneumatically disconnected from the storage region, in particular the liquid tank, by a pneumatic separation device at the liquid inlet, in particular an inlet nonreturn valve. The delivery volume region is therefore preferably formed at the far end of the storage region, downstream of the separation device at the liquid inlet.

[0029] In particular, the above-described developments enable a more or less "intelligent" (because autonomously filling) delivery volume region to be realized. Thus, the delivery volume region can be refilled autonomously, for example, directly before and / or after a cleaning process.

[0030] This is a particular advantage over the prior art described at the outset, in which the entire reservoir would have to be put under pressure. The delivery volume region according to the concept of the invention and in particular according to one of the above-mentioned developments is advantageously formed pneumatically separate from the reservoir, so to speak as a small partial volume which only needs to be used for cleaning and can be appropriately and autonomously charged for this purpose. The delivery volume region is formed, so to speak, as part of the pneumatic connection and in this sense is also connected in a fluid-conducting manner according to the concept of the invention.

[0031] Preferably, the sensor cleaning device comprises an outlet overflow valve arranged at the cleaning interface, which preferably opens in the conveying direction against the outlet spring force of the valve spring and blocks against the conveying direction. Since the sensor cleaning device has an inlet check valve and preferably additionally has an outlet overflow valve, the gate principle can be advantageously implemented. This means that the liquid flows into the conveying volume area in particular autonomously via the inlet check valve, but does not flow back due to the blocking of the inlet check valve when compressed air is subsequently applied to the compressed air input end, and thus forces the delivery amount of the liquid in the conveying volume area to be guided away from the conveying volume area via the cleaning interface. In other words, when compressed air is applied to the compressed air input end, the inlet check valve prevents the liquid in the conveying volume area from flowing back into the liquid storage tank.

[0032] After the delivery volume has left the delivery volume area, as long as compressed air is still applied to the compressed air input and the inlet non-return valve is blocked, no new liquid will be provided at the cleaning interface, but only compressed air. In this way, it is ensured that only a limited amount of liquid (i.e. the delivery volume) is always consumed during each cleaning process or each time the compressed air input is charged with compressed air. Thus, a quantitative distribution of the amount of liquid can be achieved independently of the amount of compressed air. In addition, by continuously charging the delivery volume with compressed air after it has passed the cleaning interface, it is also possible to automatically dry the sensor surface after the delivery volume of liquid has been directed to the sensor surface.

[0033] Preferably, the inlet non-return valve is designed to enable an automatic filling of the delivery volume area with liquid from the liquid storage tank. Preferably, the inlet non-return valve is not spring-loaded. In other refinements, the inlet non-return valve can have a liquid-inlet valve spring and thus be spring-loaded with a defined liquid-inlet spring force.

[0034] With the spring-loaded inlet nonreturn valve it can advantageously be achieved that liquid no longer flows autonomously into the delivery volume region when the liquid in the liquid tank falls below a minimum pressure (for example because the liquid in the liquid tank falls below a minimum fill level).

[0035] Preferably, however, in an alternative variant, the spring of the inlet nonreturn valve is adjusted differently. The inlet nonreturn valve or a similar pneumatic separating element is preferably spring-loaded in such a way that the spring opens it even in the case of a very small tank volume and therefore even in the case of a low liquid pressure from the tank. This advantageously allows residual volume to enter the delivery volume region through the default open valve even when the tank is almost empty. The valve only blocks when pressure is applied via the compressed air input, which then pushes the nonreturn valve against its spring force; that is, the nonreturn valve also blocks under the action of the compressed air, against its spring force.

[0036] Preferably, the liquid inlet and / or the inlet non-return valve are arranged in the lower region of the liquid storage tank. Preferably, the liquid inlet and / or the inlet non-return valve are arranged below the liquid storage tank in the direction of gravity. Preferably, the liquid inlet and / or the inlet non-return valve are connected in a fluid-conducting manner to the liquid storage tank via a liquid supply line.

[0037] The invention is improved by an inlet overflow valve arranged at the compressed air inlet, which opens in the direction of the compressed air loading and blocks in the direction opposite to the loading direction, and which is preferably spring-loaded. With such an inlet overflow valve, it is advantageously possible to achieve that the compressed air applied at the compressed air inlet has an effect on the delivery volume area and on cleaning only when the delivery pressure of the compressed air exceeds a minimum pressure in the form of an inlet overflow pressure. In this way, compressed air flows with lower pressure, which are caused by specific exhaust processes and whose pressure level is insufficient for effective cleaning or liquid delivery, can be disregarded.

[0038] In a preferred refinement, the outlet overflow valve is spring-loaded and has an outlet valve spring. By means of the spring-loaded outlet overflow valve, it is advantageously possible to prevent liquid from accidentally discharging via the outlet overflow valve when no compressed air is applied to the compressed air inlet.

[0039] It is preferably provided that the outlet overflow valve and / or the inlet non-return valve and / or the inlet overflow valve are each designed as a piston valve, preferably with an integrated spring element. Preferably, at least two of the outlet overflow valve, the inlet non-return valve and the inlet overflow valve are designed identically in order to advantageously reduce the structural complexity of the sensor cleaning device.

[0040] In a preferred improvement, it is provided that the compressed air input has a blocking valve seat, which can be closed by the inlet overflow valve depending on the inlet overflow valve position, and a pressure chamber is pneumatically connected between the inlet overflow valve and the blocking valve seat. The pressure chamber is configured to receive a compressed air pulse amount from the compressed air input when the inlet overflow valve is in the open inlet overflow valve position, and to provide the compressed air pulse amount to the delivery volume area via the blocking valve seat when the inlet overflow valve is in the closed overflow valve position. With this arrangement of the blocking valve seat and the pressure chamber, compressed air pulses can be advantageously generated even when the compressed air load at the compressed air input ends again, in particular when there is no longer a long-lasting compressed air load. The compressed air pulse in the form of a compressed air pulse amount is advantageously also transmitted to the delivery amount or liquid in a pulsed manner, as a result of which the delivery amount or liquid is provided to the cleaning interface or at least one cleaning nozzle in a pulsed manner. In this respect, it is advantageously provided that the actual cleaning only begins when the compressed air load at the compressed air input is canceled; in other words, the actual cleaning begins when the blocking valve seat is opened.

[0041] Such an arrangement of blocking valve seat and pressure chamber also makes it possible to provide a compressed air pulse quantity which is always constant in terms of its quantity and its pressure, namely independently of the delivery pressure and duration of the pressure applied to the compressed air inlet.

[0042] Furthermore, this also enables the parallel calling of the working air of the compressed air consumer as a compressed air source; this is possible because, due to the design of the delivery volume area, only a limited amount of compressed air (compressed air pulse amount) can flow in, and therefore the working compressed air of the compressed air consumer does not flow out continuously via the sensor cleaning unit during operation of the compressed air consumer.

[0043] Therefore, theoretically, the working air of the service brake can also be used for sensor cleaning, and the cleaning can be triggered by actuating the brake. Preferably, it can be provided for this purpose that the inlet overflow valve opens only above a certain brake pressure. Advantageously, the sensor cleaning can be achieved by actuating the service brake above a minimum pressure.

[0044] An improved cleaning effect can also be achieved by means of a pulsed application of the sensor surface.

[0045] The invention is improved by a liquid tank which is connected or connectable to the liquid inlet in a fluid-conducting manner. Preferably, the liquid tank and the sensor cleaning device can be designed in an integrated manner, particularly preferably in one piece.

[0046] In the context of a preferred development, it is provided that the delivery volume region is arranged in the liquid tank or projects into the liquid tank, wherein the liquid inlet is preferably arranged in the lower region of the liquid tank. In particular, the lower region is understood to be that part of the liquid tank which is located in the lower 20%, preferably in the lower 10%, particularly preferably in the lower 5% of the tank height (that is to say of the vertical extension) of the liquid tank.

[0047] The invention is developed in that the compressed air inlet and / or the compressed air branch is arranged in or at the liquid tank, preferably in the tank wall, and the liquid inlet is arranged in or at the delivery volume region, preferably in the container wall.

[0048] Preferably, the delivery volume region comprises an immersion tube extending into the liquid storage tank, the immersion tube comprising a liquid input, and a delivery channel arranged outside the liquid storage tank, the delivery channel comprising a compressed air input on a first side and a cleaning interface on an opposite second side, wherein the immersion tube is connected to the delivery channel in a fluid-conducting manner at an immersion tube interface located between the first side and the second side. Particularly preferably, the immersion tube is arranged approximately in the direction of gravity, so that the liquid input is arranged in the lower region of the liquid storage tank. Particularly preferably, the delivery channel comprises a compressed air branch between the compressed air input and the immersion tube interface, which connects the delivery channel to the liquid storage tank, in particular to the upper region of the liquid storage tank, in a fluid-conducting manner, in particular pneumatically. Particularly preferably, the upper region of the liquid storage tank is free of liquid, that is, the maximum filling height of the liquid storage tank is lower than the upper region. By means of the compressed air branch, the liquid in the liquid storage tank can be advantageously loaded with compressed air by means of the delivery pressure applied at the compressed air input, and the liquid is then conveyed to the immersion tube interface via the liquid input and the immersion tube. At the immersion tube interface, the liquid is in particular received by the throttled air flow and conveyed to the cleaning interface. Particularly preferably, the conveying channel and / or the immersion tube interface is designed to form a spray mixture at the immersion tube interface when encountering the throttled air flow, which spray mixture is provided to the cleaning interface for at least one cleaning nozzle. The spray mixture is a mixture of air and fine liquid droplets or water droplets, which mixture can be advantageously guided to the sensor surface via the cleaning nozzle in this way.

[0049] In particular, the compressed air inlet and / or the compressed air branch are arranged in the upper region of the liquid tank. In particular, the upper region refers to the portion of the liquid tank that is located in the upper 20%, preferably the upper 10%, and particularly preferably the upper 5% of the tank height (i.e. the vertical extension) of the liquid tank.

[0050] In a preferred development, it is provided that the compressed air inlet and / or the liquid inlet and / or the cleaning connection are arranged at or in the delivery volume region.

[0051] In a preferred development, the compressed air inlet is spaced apart from the clean interface with respect to the delivery direction and / or the longitudinal axis of the delivery volume area. Preferably, the compressed air inlet is arranged opposite the clean interface with respect to the delivery volume area and / or the delivery direction.

[0052] This means in particular that the greater the delivery distance, preferably at a constant average cross-sectional area of ​​the delivery volume region, the greater the effective delivery volume of the liquid. Likewise, it is additionally or alternatively possible to adjust the cross-sectional area of ​​the delivery volume region in order to structurally change the delivery volume.

[0053] In particular, the delivery volume region has an elongated shape, in particular has an aspect ratio of the type that the ratio of the length along the longitudinal axis to the average diameter is greater than 5.

[0054] In the context of a preferred development, it is provided that the outlet overflow valve is spaced apart from the inlet non-return valve by a delivery height in the direction of gravity. This means in particular that the outlet overflow valve is arranged below the inlet non-return valve in the direction of gravity at a distance of the delivery height. In this way, in particular, the capacity of the delivery volume region can be increased by a proportion that is independent of the filling height of the liquid tank and can be filled with liquid autonomously. Preferably, the delivery volume region is arranged essentially vertically, in particular with a longitudinal axis arranged approximately vertically. In particular, the sensor cleaning device comprises a nozzle line, which is particularly preferably arranged at least partially parallel to the delivery volume region.

[0055] Preferably, the cleaning connection is arranged above the maximum filling height of the liquid tank and / or the delivery volume area. In this refinement, the outlet overflow valve can be advantageously omitted.

[0056] In a preferred development, a solenoid switching valve is provided which is arranged at the compressed air inlet and is designed to controllably load the compressed air inlet. The solenoid switching valve is particularly preferably electrically or electronically controllable. Preferably, the solenoid switching valve is a valve of a further compressed air consumer in the pneumatic system of the vehicle, which valve is designed completely or partially to supply compressed air to the compressed air inlet of the sensor cleaning device.

[0057] Preferably, the electromagnetic switching valve is integrated into the sensor cleaning device, in particular integrated into a housing of the sensor cleaning device, or fastened to the housing, preferably flange-connected.

[0058] In a preferred improvement, the sensor cleaning device has a liquid level sensor, which is configured to determine the filling height of the liquid in the liquid tank and / or in the delivery volume area. Preferably, the liquid level sensor is arranged in the delivery volume area. The liquid level sensor arranged in the delivery volume area is particularly advantageous when it is necessary to omit the overflow valve. Preferably, the liquid level sensor and the electromagnetic switching valve are connected to the electronic control unit via a common electrical line, which is preferably a twisted pair. Preferably, the liquid level sensor includes an electrical element, which is configured to change its resistance and / or its capacitance or and / or its inductance depending on the filling height in the delivery volume area and / or in the liquid tank. Preferably, the electronic control unit is configured to determine this change of the electrical element of the liquid level sensor by means of an electrical test pulse, and particularly preferably, this is done without switching the electromagnetic switching valve.

[0059] The invention achieves this object in a second aspect by a pneumatic system according to claim 15. A pneumatic system for a vehicle has a sensor cleaning device according to the first aspect of the invention and at least one sensor having a sensor surface.

[0060] In a development of the pneumatic system, the sensor cleaning device is or can be connected pneumatically to a compressed air source, preferably controllably via a solenoid switching valve.

[0061] In one development of the pneumatic system, a compressed air consumer is provided. In particular, the compressed air consumer is used for a primary purpose other than sensor cleaning.

[0062] Preferably, the exhaust air connection of the compressed air consumer is pneumatically connected or connectable to the compressed air inlet in order to receive exhaust compressed air as compressed air. In a refinement of such a pneumatic system, in particular, exhaust air which would otherwise be directed to the surroundings when not being used can be utilized for operating the sensor cleaning device. In particular, such a refinement of the pneumatic system can be designed without an additional electromagnetic switching valve, so that the sensor cleaning device is always operated when exhaust air is present.

[0063] Preferably, the working interface of the compressed air consumer is pneumatically connected or connectable to the compressed air input for receiving working compressed air as compressed air. In a refinement of this pneumatic system, the working compressed air of the compressed air consumer can preferably be used alternatively or additionally for other uses of the working compressed air in the compressed air consumer.

[0064] Preferably, a storage interface of a compressed air source, preferably a storage interface of a compressed air storage container and / or a compressor, is pneumatically connected or connectable to the compressed air input end for receiving reserve compressed air as compressed air. In a refinement of such a pneumatic system, an electromagnetic switching valve can be arranged at the storage interface, which is configured to controllably provide reserve compressed air and / or can drive the compressor in dependence on an electrical switching signal.

[0065] Preferably, the compressed air consumer is an air spring system with at least one air spring. Preferably, the compressed air consumer is a brake system, in particular a parking brake system with at least one parking brake cylinder or a service brake system with at least one service brake cylinder. Preferably, the compressed air consumer is a pneumatic steering axle lock or anti-theft lock or container locking system. Preferably, the compressed air consumer is a lifting axle with at least one lifting bag. Nevertheless, other compressed air consumers can also be used for the pneumatic system according to the second aspect of the invention with the sensor cleaning device according to the first aspect of the invention.

[0066] The invention achieves this object in a third aspect by a vehicle according to claim 17. The vehicle is preferably a commercial vehicle, a passenger vehicle or a trailer. The vehicle has a sensor cleaning device according to the first aspect of the invention or a pneumatic system according to the second aspect of the invention.

[0067] The invention achieves this object in a fourth aspect by the method of claim 18. The method according to the invention for operating a sensor cleaning device comprises the following steps:

[0068] - autonomously filling the delivery volume region with liquid from the liquid tank, preferably via an inlet non-return valve;

[0069] - The liquid is acted upon by compressed air which is in pressure-transmitting contact with the liquid.

[0070] The pressure-transmitting contact is in particular a direct contact between the compressed air and the liquid. Additionally or alternatively, the pressure-transmitting contact forms a phase boundary between the compressed air and the liquid.

[0071] The method for operating the sensor cleaning device further comprises the following steps:

[0072] - Supply pressurized liquid to the cleaning connection.

[0073] Since the liquid is acted upon by compressed air, which is in pressure-transmitting contact with the liquid, the cleaning interface is provided with pressurized liquid.

[0074] In addition, in particular, compressed air can also be provided to the cleaning interface. Compressed air can preferably be provided to the cleaning interface subsequently or simultaneously. When compressed air and liquid are provided simultaneously, a spray mixture consisting of compressed air and liquid is preferably provided.

[0075] Preferably, the supply of compressed air to the cleaning interface can be carried out according to the request of the vehicle driver or the system. Therefore, the cleaning trigger can be realized particularly simply. For example, this can include actions such as stepping on the brake to provide compressed air or systematically triggering compressed air.

[0076] In a preferred development of the method, a delivery quantity of liquid is delivered via the sensor cleaning device, whereby the steps are formed as follows: the delivery volume area is preferably filled autonomously with the delivery quantity of liquid from a liquid storage tank via an inlet non-return valve; the delivery quantity of liquid is charged with compressed air in direct pressure-transmitting contact; thereby, a delivery quantity of pressurized liquid is provided and, preferably subsequently or simultaneously, the cleaning interface is supplied with compressed air.

[0077] In a preferred refinement of the method, the following steps are provided: liquid, preferably a delivery volume and / or compressed air, is directed to the sensor surface of the sensor; a waiting time period is determined from the activation of the electromagnetic switching valve for the controlled application of compressed air to the liquid until the impingement on the sensor surface, and / or a loading time period is determined, preferably by means of the sensor to be cleaned itself, during which the sensor surface is exposed to the liquid; and the filling height of the liquid in the liquid tank and / or in the delivery volume region is determined as a function of the waiting time period and / or the loading time period. In this refinement, the liquid level can be indirectly measured without an additional liquid level sensor by having the sensor to be cleaned measure how long it has been since the electromagnetic switching valve has been activated or switched until the liquid has been discharged through the cleaning nozzle and / or how much liquid has been discharged from the cleaning nozzle, that is, how long it has been since the liquid began to be discharged.

[0078] In a preferred development of the method, the following step is provided: controlling the compressed air consumer, preferably actuating the compressed air consumer, in order to supply the sensor cleaning device, preferably the compressed air inlet of the sensor cleaning device, with working compressed air for charging the liquid. Preferably, actuating the compressed air consumer comprises actuating a brake system, in particular a parking brake system with at least one parking brake cylinder or a service brake system with at least one service brake cylinder, or a pneumatic steering axle lock, an anti-theft lock or a container locking system, or a lifting axle with at least one lifting bag. Preferably, actuating the compressed air consumer comprises fully actuating, particularly preferably providing, a maximum amount of working compressed air.

[0079] Therefore, in a preferred embodiment, part of its working air is used as compressed air for the cleaning system or cleaning is triggered, for example by (complete) actuation of a compressed air consumer; for example, by complete actuation of the brakes, by (briefly) actuating lift bags of a lifting axle, etc.

[0080] Triggering the cleaning by simply “fully pressing the brake” is relatively easy to implement. It has been shown in particular that this can occur without additional communication between the towing vehicle and the trailer (truck / trailer) of vehicle 1000 and can be conveniently controlled by the driver.

[0081] For example, technically it is theoretically possible to use the brake pressure directly as compressed air or to sense the brake pressure from the trailer via an electronic brake system (EBS system). This electronic brake system would recognize a complete actuation of the brake by the driver as a request to trigger cleaning and would itself actuate a corresponding compressed air valve connected to the compressed air inlet.

[0082] In a preferred development of the method, the following step is provided: venting the compressed air consumer, preferably ending the actuation of the compressed air consumer, in order to supply the sensor cleaning device with vented compressed air, preferably to supply the vented compressed air to a compressed air inlet of the sensor cleaning device, for charging the liquid. Preferably, venting the compressed air consumer includes venting a brake system, in particular a parking brake system with at least one parking brake cylinder or a service brake system with at least one service brake cylinder, or a pneumatic steering axle lock or an anti-theft lock or a container locking system or a lifting axle with at least one lifting bag.

[0083] It should be understood that the sensor cleaning device according to the first aspect of the invention, the pneumatic system according to the second aspect of the invention, the vehicle according to the third aspect of the invention and the method according to the fourth aspect of the invention have identical and similar sub-aspects, especially as reflected in the dependent claims. In this respect, the improvements of one aspect of the invention also refer to the improvements of other aspects of the invention.

[0084] Now, embodiments of the invention will be described below with the aid of the accompanying drawings by comparison with the prior art, which is also partially shown. These drawings do not necessarily reflect the embodiments in exact dimensions, but rather the drawings used for explanation are implemented in a schematic and / or slightly distorted form. For additional information on the teachings that can be directly derived from the drawings, reference is made to the relevant prior art. It should be taken into account that various modifications and changes can be made to the manner and details of the embodiments without departing from the general idea of ​​the invention. The features of the invention disclosed in the description, drawings and claims are of great significance to the improvement scheme of the invention, whether individually or in any combination. In addition, all combinations of at least two features disclosed in the description, drawings and / or claims fall within the scope of the invention. The general idea of ​​the invention is not limited to the exact form or details of the preferred embodiments shown and described below, nor to the subject matter that is limited compared to the subject matter claimed in the claims. With regard to the set measuring range, the values ​​within the mentioned limit ranges should also be disclosed as limit values ​​and can be used arbitrarily and should be protected by rights. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Further advantages, features and details of the present invention will be found in the following description of preferred embodiments in conjunction with the accompanying drawings; in which:

[0086] Figure 1 A vehicle in the form of a trailer is shown having a sensor cleaning device according to the concept of the present invention;

[0087] Figure 2 A preferred embodiment of a sensor cleaning device according to the concept of the present invention is shown;

[0088] Figure 2A A preferred first embodiment of a sensor cleaning device according to the concept of the present invention is shown in a non-operated state;

[0089] Figure 2B A preferred first embodiment of a sensor cleaning device according to the concept of the present invention in an actuated state is shown;

[0090] Figure 3 A preferred second embodiment of a sensor cleaning device in a first variant of the concept according to the present invention is shown;

[0091] Figure 3A A preferred second embodiment of a sensor cleaning device in a second variant of the concept according to the present invention is shown;

[0092] Figure 3B A preferred second embodiment of a sensor cleaning device according to the concept of the present invention in a third variant is shown;

[0093] Figure 4A A preferred third embodiment of a sensor cleaning device according to the concept of the present invention is shown in a non-operated state;

[0094] Figure 4B A preferred third embodiment of the sensor cleaning device according to the concept of the present invention in an actuated state is shown;

[0095] Figure 5 A preferred fourth embodiment of a sensor cleaning device according to the concept of the present invention is shown;

[0096] Figure 6 A preferred fifth embodiment of the sensor cleaning device according to the concept of the present invention is shown;

[0097] Figure 7 A preferred sixth embodiment of the sensor cleaning device according to the concept of the present invention is shown;

[0098] Fig. 8A A seventh preferred embodiment of the sensor cleaning device according to the present invention is shown.

[0099] Figure 8B A preferred eighth embodiment of the sensor cleaning device according to the concept of the present invention is shown;

[0100] Figure 8CA preferred and modified ninth embodiment of the sensor cleaning device according to the invention shows a first and a second further variant of the inlet overflow valve in combination with partially matched pressure chambers and delivery volume regions, which otherwise corresponds to the embodiment according to Figure 8B The preferred eighth embodiment is designed the same;

[0101] Fig. 9 A schematic diagram of a pneumatic system with a compressed air consumer and a sensor cleaning device according to the concept of the invention is shown. DETAILED DESCRIPTION

[0102] Figure 1 A vehicle 1000 is shown schematically, in the present case in the form of a trailer 1006. The following description is applicable to any other type of vehicle 1000 in a meaningful manner and without limitation. However, due to the advantageous simple design of the sensor cleaning device described below, the sensor cleaning device is particularly advantageously suitable for trailers. Such a trailer 1006 is described below in a preferred embodiment.

[0103] The trailer 1006 has a sensor 300 with a sensor surface 301 in the rear region 1007 for detecting the surrounding environment U. At present, the sensor 300 is constructed as an optical sensor 302 in the form of a camera 304. The trailer 1006 also has a cleaning nozzle 320, which is fixedly arranged and oriented relative to the sensor surface 301 so that the cleaning nozzle cleans the sensor surface 301 with a liquid F and / or compressed air DL. For this purpose, the cleaning nozzle 320 is connected to the cleaning interface 310 of the sensor cleaning device 100 according to the concept of the present invention in a fluid-conducting manner. The sensor cleaning device 100 includes a liquid input end 680 connected to the liquid tank 660 in a fluid-conducting manner. The liquid tank 660 can also be constructed as a central washing water tank of the vehicle 1000 in an embodiment, and is therefore used as a reservoir for other cleaning devices of the vehicle 1000. As the liquid F, water or a liquid containing a cleaning additive can be used in particular.

[0104] The sensor cleaning device 100 comprises a compressed air input 270 which is pneumatically connected to a compressed air consumer 820 of a pneumatic system 800 of the vehicle 1000. The pneumatic system 800 comprises an air spring system 730 with a plurality of air springs 732, which are schematically shown here. The trailer 1006 comprises an electromagnetic switching valve 290 in the form of an electronically switchable air spring valve 734 of the air spring system 730. By means of the electronically controllable electromagnetic switching valve 290, compressed air from a compressed air source, which is not shown in detail here, can be supplied to the compressed air input 270 in a controllable manner depending on an electronic control signal S1. In the present case, the electronic switching signal S1 is provided by the electronic control unit 700.

[0105] Figure 2 A preferred first embodiment of a sensor cleaning device 100 according to the concept of the present invention is shown. The sensor cleaning device 100 comprises a delivery volume region 110 which is configured to accommodate a delivery amount MF of a liquid F. The delivery volume region 110 comprises a container wall 112 which encloses a defined volume for accommodating the delivery amount MF of the liquid F; the container wall 112 can be configured as part of a pneumatic connection, for example. The delivery volume region 110 has a liquid input 680 for receiving the liquid F from a liquid storage tank 660. An inlet non-return valve 130 or a similar pneumatic separation device is arranged at the liquid input 680.

[0106] In the present embodiment, therefore, it is ensured in particular that the delivery volume region 110 is pneumatically disconnected from the storage region, in particular the liquid tank 660, by means of the pneumatic separation means, in particular the inlet non-return valve 130, at the liquid inlet 680. Nevertheless, in the present case, the storage region, in particular the liquid tank 660, is still connected or connectable to the liquid inlet 680 in a fluid-conducting manner.

[0107] The delivery volume region 110 is therefore formed distally from the storage region downstream of the pneumatic partitioning means at the liquid inlet 680 .

[0108] The inlet non-return valve 130 is designed to open in the conveying direction FR and to block in the direction opposite to the conveying direction FR, wherein the conveying direction FR extends from the liquid tank 660 via the conveying volume area 110 to the cleaning interface 310. This means that the liquid F flowing in the conveying direction FR can pass through the inlet non-return valve 130 and can therefore flow from the liquid tank 660 into the conveying volume area 110. However, a flow of the liquid F from the conveying volume area 110 into the liquid tank 660 is not possible.

[0109] In the present case, the liquid inlet 680 and the delivery volume region 110 are arranged in the lower region 670 of the liquid tank 660 relative to the gravity G and the tank height HT, thereby advantageously enabling an autonomous replenishing flow of liquid F into the delivery volume region 110. The liquid tank 660 can be connected to the delivery volume region 110 directly or via a relatively short liquid supply line 612, as shown here. The liquid supply line 612 leads into the liquid tank 660 at an opening in the tank wall 669 of the liquid tank 660. In other embodiments, it is also possible to arrange the liquid tank 660 in the vehicle 1000 at a distance from the delivery volume region 110 via a correspondingly longer liquid supply line 612.

[0110] The delivery volume region 110 further comprises a cleaning interface 310, which is connected to the cleaning nozzle 320 in a fluid-conducting manner via a nozzle line 610. An outlet overflow valve 134 having an outlet valve spring 135A and an outlet valve body 135B is arranged at the cleaning interface 310. The outlet overflow valve 134 is configured to open in the delivery direction FR against the outlet spring force FS dependent on the outlet valve spring 135A, and to block against the delivery direction FR. If the delivery pressure PF in the delivery volume region 110 exceeds the outlet overflow pressure PU, the outlet valve body 135B is lifted from the outlet valve seat 135C of the outlet overflow valve 134, and thus enables the liquid F and / or compressed air DL to pass from the delivery volume region 100 in the direction of the nozzle line 610 and the cleaning nozzle 320. The passage of compressed air DL and / or liquid F against the delivery direction FR, that is, from the nozzle line 610 to the delivery volume region 110, is impossible because the outlet overflow valve 134 is blocked. However, if the delivery pressure PF is absent or only low, the outlet relief valve prevents the outflow of cleaning fluid.

[0111] The delivery volume region 110 further includes a compressed air input 270 configured to receive compressed air DL. An inlet overflow valve 138 having an inlet valve spring 139A and an inlet valve body 139B is arranged at the compressed air input 270. The inlet overflow valve 138 is configured to open in a loading direction BR, i.e., in a direction into the delivery volume region 110, against an inlet spring force FE dependent on the inlet valve spring 139, and to block against the loading direction BR.

[0112] If the pressure applied at the compressed air inlet 270, in particular the delivery pressure PF, exceeds the inlet overflow pressure PE, the inlet valve body 139B is lifted from the inlet valve seat 139C of the inlet overflow valve 138, thereby enabling an inflow of compressed air DL from the compressed air inlet 270 into the delivery volume region 110. The inlet overflow valve 138 advantageously prevents the liquid F from being discharged via the compressed air inlet 270, even if the filling height HF of the liquid tank 660 exceeds the position of the compressed air inlet 27 relative to the direction of the gravity G.

[0113] In the present case, the delivery volume region 110 has a container wall 112, which encloses an elongated, approximately cylindrical space extending along the longitudinal axis AL. Nevertheless, in other embodiments, the delivery volume region 110 can still have a different non-cylindrical shape. The liquid inlet 680 and the compressed air inlet 270 are arranged at the first end side 114A of the cylinder or the delivery volume region. The cleaning interface 310 is arranged on the second end side 114B, which is opposite to the first end side 114A and is arranged at a delivery distance AF therefrom.

[0114] Sensor cleaning device 100 can advantageously be controlled by applying compressed air DL to compressed air inlet 270 .

[0115] Figure 2A A preferred first specific embodiment of the sensor cleaning device according to the concept of the present invention is now shown in the non-actuated state.

[0116] In the delivery volume region 110 there is a delivery quantity MF of the liquid F, which arrives there autonomously from the liquid storage tank 660 by the action of gravity G via the liquid inlet 680 and the inlet nonreturn valve 130. Figure 2A In the sensor cleaning device 100 in the non-operated state shown in FIG, the inlet overflow valve 138 is closed. That is, the inlet overflow valve is blocked under the dominant effect of the inlet valve spring 139A and the inlet overflow pressure PE.

[0117] If the compressed air inlet 270 is now acted upon by compressed air DL having a delivery pressure PF which is greater than the inlet overflow pressure PE, the inlet overflow valve 138 opens. Figure 2B Accordingly, a preferred first specific embodiment of the sensor cleaning device 100 according to the concept of the present invention is shown in an actuated state; that is to say, the inlet valve body 139B is lifted off the inlet valve seat 139C of the inlet overflow valve 138 .

[0118] The compressed air DL here comes into direct contact with the delivery quantity MF of the liquid F in the delivery volume region 110 and acts on the liquid. The delivery pressure PF therefore acts on the delivery quantity MF of the liquid F in the delivery volume region 100. As a result, the delivery quantity MF of the liquid F at the delivery pressure PF is acted on the outlet overflow valve 134, which opens against the outlet spring force FS.

[0119] The inlet check valve 130 blocks the delivery volume MF of the liquid F at the delivery pressure PF. Therefore, the delivery volume MF of the liquid F is guided to the cleaning nozzle 320 via the outlet overflow valve 134 and the nozzle line 610 and from there further to the sensor surface 310 (not shown here).

[0120] The duration of the application of compressed air DL can advantageously be adjusted such that, when the delivery volume MF leaves the delivery volume region 110, the application of compressed air DL continues, in particular by correspondingly controlling the electromagnetic switching valve 290 which is pneumatically connected to the compressed air inlet 270 and is not shown here. As a result, after the liquid F has been delivered, the compressed air DL is further guided through the delivery volume region 110, the outlet overflow valve 134 and the cleaning nozzle 320 to the sensor surface 310, thereby achieving drying and / or removal of the liquid F from the sensor surface 310.

[0121] exist Figure 3 FIG. 2 shows a preferred second embodiment of a sensor cleaning device 100 according to the concept of the present invention. Figure 2 In contrast to the first specific embodiment shown in FIG. 1 , the sensor cleaning device 100 shown here does not have an inlet overflow valve 138 at the compressed air inlet 270 .

[0122] Instead, the compressed air inlet 270 is arranged relative to the liquid tank 660 such that the maximum filling height HFM of the liquid tank 660 relative to the direction of gravity G is always located below the compressed air inlet 270 .

[0123] The outlet overflow valve 134 can also be arranged closer to the cleaning interface 310 or formed together with the cleaning interface; Figure 3 1 and 2. This is shown by the additional or alternative outlet overflow valve 134 drawn with a dashed line in FIG. In principle, the outlet overflow valve 134 itself or the outlet overflow valve 134 as a separate valve can also be omitted. Figure 3AAccordingly, a preferred second embodiment of the sensor cleaning device 100 in a second variant of the concept according to the invention is shown, without the inlet overflow valve 138 at the compressed air input 270, and also without the aforementioned outlet overflow valve 134 itself, in particular without the outlet overflow valve 134 as a separate valve. This embodiment shows an embodiment in which the design structure on the tank or the inlet / outlet opening is located in the delivery volume area 110 above the liquid storage tank 660; this enables Figure 3A The embodiment shown in FIG. is only designed with a delivery volume area 110 and an inlet nonreturn valve 130. If the compressed air inlet 270 and the cleaning interface 310 or their respective inflow / outflow lines are arranged above the liquid filling level of the liquid tank 660, preferably above the upper edge of the liquid tank 660, the outlet overflow valve 134 and the inlet overflow valve 138 can be eliminated.

[0124] and Figure 2 A further difference from the first embodiment shown in is that the delivery volume region 110 is now essentially vertically oriented. This means that the longitudinal axis AL of the delivery volume region 110 extends essentially in the direction of the gravity G. In the present case, the delivery quantity MF depends on the actual filling height HF of the liquid F in the liquid tank 660, because the delivery volume region 110 is also filled with liquid F to this filling height HF. This is the case in particular since the sensor cleaning device 100 does not have an inlet overflow valve 138 that limits the liquid F. The delivery length AF that defines the delivery quantity MF together with the cross-sectional area AQ of the delivery volume region 110 is now composed of the filling height HF and the delivery height HFZ, wherein the delivery height HFZ is the distance between the liquid inlet 680 and the cleaning interface 310 arranged below the liquid inlet 680, which extends in the direction of the gravity G.

[0125] Figure 3B A preferred second embodiment of a sensor cleaning device 100 in a third variant of the concept according to the invention is shown. In the design structure visible in the figure, a simple inlet non-return valve 130 arranged at the level of the tank bottom or arranged below the liquid storage tank 660 has an inlet / outlet flow line extending beyond the upper edge of the tank. The advantage of this design is that the cleaning liquid cannot accidentally flow out.

[0126] Figure 4A FIG. 2 shows a preferred third embodiment of the sensor cleaning device 100 in a non-operated state. Figure 3 , Figure 3A and Figure 3BAs in the second embodiment shown, the sensor cleaning device has a delivery volume region 110 extending in the direction of gravity G, ie the longitudinal axis AL of the delivery volume region 110 extends substantially parallel to the direction of gravity G. The delivery length AF substantially corresponds to the filling height HF of the liquid tank 660 .

[0127] The inlet check valve 130 has the same structure as the outlet relief valve 134 and therefore has a liquid-inlet valve spring 131A, a liquid-inlet valve body 131B and a liquid-inlet valve seat 131C. The inlet check valve 130 is accordingly configured to be actively opened in the delivery direction FR by the liquid-inlet spring force FEF, thereby achieving Figure 4A The liquid F shown in FIG. 1 reaches the state of delivery volume MF (as shown in FIG. 1 ). Figure 2 , Figure 2A As explained above). The inlet nonreturn valve 130 is accordingly designed to block against the conveying direction FR. In the present case, both the outlet valve spring 135A and the liquid inlet valve spring 131A are designed as curved spring elements.

[0128] In the third embodiment, the inlet check valve 130 is constructed in a substantially identical manner to the outlet relief valve 134. Thus, a further reduction in the complexity of the sensor cleaning device 100 can be advantageously achieved. Therefore, the outlet relief valve 134 has an outlet valve body 135B which is held against an outlet valve seat 135C by an outlet valve spring 135A. The outlet relief valve 134 is similar to Figure 2B In the embodiment shown in FIG. 1 , the outlet overflow valve 134 is configured to block against the conveying direction FR. In particular, the outlet overflow valve 134 can be similar to Figure 2B In the embodiment shown in FIG. , it is designed to open in the conveying direction FR against the outlet spring force FS. Figure 4B A third preferred embodiment of the sensor cleaning device according to the concept of the present invention is shown in an actuated state.

[0129] Figure 5 FIG. 1 shows a preferred fourth embodiment of the sensor cleaning device 100. The sensor cleaning device 100 is substantially similar to Figure 4A , Figure 4B , with the difference that the liquid tank 660 is not integrated into the sensor cleaning device 200 or integrally connected thereto. In contrast, in the embodiment shown here, it is possible to arrange the sensor cleaning device 100 away from the liquid tank 660. In particular, the liquid input 680 of the sensor cleaning device 100 can be connected to the liquid tank 660 in a fluid-conducting manner by means of a liquid supply line 612 (not shown here).

[0130] In addition, Figure 5Also shown in FIG. 2 is an electrically controllable electromagnetic switching valve 290 arranged at the compressed air input 270 . The electromagnetic switching valve 290 is configured to controllably provide compressed air DL at the compressed air input 270 .

[0131] The sensor cleaning device 100 also has a level sensor 294 arranged in the delivery volume area 110, which is designed to determine the level of the liquid F contained in the delivery volume area 110, in particular the filling height HF, and to provide a corresponding, in particular proportional, in particular electrical level signal S2 depending on the determined filling height HF, in particular with a change in the filling height HF. In the present case, the electromagnetic switching valve 290 is connected to the level sensor 294 via an electrical line 707 for receiving the electrical level signal S2.

[0132] Preferably, the electromagnetic switching valve 290 or the electric or electronic control unit 700 connected to the electromagnetic switching valve in a signal-conducting manner is designed to provide compressed air DL at the compressed air input 270 by providing an electronic switching signal S1 when the filling level HF is sufficiently high. And / or to terminate the supply of compressed air DL, in particular by terminating the provision of the electronic switching signal S1, when the filling level HF is sufficiently low.

[0133] exist Figure 6 A further preferred fifth embodiment of the sensor cleaning device 100 is shown in FIG. Figures 2 to 5 Unlike the first to fourth embodiments shown, the embodiments shown here are not based on the principle of a gate with an inlet nonreturn valve and an outlet overflow valve. The delivery volume area 110 now includes an immersion tube 116 that projects downwardly into the liquid storage tank 660 in the direction of gravity G. The liquid inlet 680 is arranged on a first end side 114A located below in the direction of gravity G. The liquid inlet 680 is arranged in the lower area 670 of the liquid storage tank 660. At a second end side 114B of the immersion tube 116 that is opposite to the first end side 114A, the immersion tube 116 is connected to the delivery channel 118 of the delivery volume area 110 in a fluid-conducting manner.

[0134] The conveying channel 118 is also elongated along the longitudinal axis AL, wherein the compressed air inlet 270 is arranged on the first side 119A and the cleaning interface 310 is arranged on the opposite second side 119B. The conveying direction FR therefore extends from the first side 119A to the second side 119B.

[0135] Between the first side 119A, i.e. the compressed air inlet 270, and the second side 119B, i.e. the cleaning connection 310, an immersion pipe connection 117 is arranged in the conveying channel 118, via which the immersion pipe 116 is connected to the conveying channel 18 in a fluid-conducting manner. In the present case, the immersion pipe connection 117 is designed as a pipe nipple bent in the conveying direction FR, whereby the liquid F conveyed into the conveying channel 118 via the immersion pipe 116 is accelerated in the direction of the cleaning connection 310. The immersion pipe connection 117 projects into the conveying channel 118 and thus produces a throttling effect on the passing throttling air flow DLD due to the resulting reduction of the cross section of the conveying channel 118 to the throttling cross section AQ.

[0136] A compressed air branch 272 is arranged between the first side 119A (i.e., the compressed air input 270) and the immersion tube interface 117. The compressed air branch 272 connects the delivery channel 118 to the upper region 672 of the liquid storage tank 660 in a fluid-conducting manner. In this way, the delivery pressure PF of the compressed air DL provided at the compressed air input 270 can be transmitted to the liquid F in the liquid storage tank 660. This will result in the liquid F loaded with the delivery pressure PF being guided to the cleaning interface 310 via the liquid input 680 and the immersion tube 116 and further via the immersion tube interface 117, where it is provided for the cleaning nozzle 320 not shown here.

[0137] The embodiment shown here also advantageously enables the provision of liquid F and compressed air DL as spray mixture GS. The generation of spray mixture GS can advantageously be achieved by structural design of sensor cleaning device 100 , in particular of delivery pressure PF and / or throttle cross section AQ.

[0138] In particular, since no inlet check valve is provided in the illustrated embodiment, a continuous delivery, in particular as spray mixture GS, is possible with the illustrated sensor cleaning device 100 for the duration of the application of compressed air DL to compressed air inlet 270 .

[0139] Figure 7 A preferred sixth embodiment of the sensor cleaning device 100 is shown in FIG. Figure 6Unlike the embodiment shown in , the sensor cleaning device 100 shown here has an inlet non-return valve 130, which is arranged at the liquid inlet 680 of the delivery volume area 110. The delivery volume MF of the liquid F is blocked in the delivery volume area 110 by the inlet non-return valve 130, and the delivery volume is provided to the cleaning interface 310 by applying compressed air DL to the compressed air inlet 270. The liquid F is provided through the connection of the immersion tube 116 via the immersion tube interface 117 in the delivery channel 118 and thus becomes a spray mixture GS when mixed with the throttle air flow DLD guided through the throttling cross section AQ. In addition to the delivery channel 118 and the immersion tube 116, the delivery volume area 110 also has a delivery chamber 113, which connects the compressed air branch 272 to the immersion tube 116, that is, to the immersion tube opening 116A arranged in the lower area 670 of the liquid tank 660, and is therefore isolated from the rest of the liquid tank 66. Therefore, liquid F from the liquid tank 660 can only reach the delivery volume area 110 via the inlet non-return valve 130. In particular, a defined delivery amount MF can be delivered by means of the application of compressed air DL. When the compressed air inlet 270 and the compressed air branch 272 are applied with compressed air DL, the inlet non-return valve 130 is blocked, so that no liquid F can flow back during the supply at the cleaning interface 310. Therefore, the delivery amount MF is the liquid F that is maintained from the immersion tube 116 to the filling height HF and additionally from the delivery chamber 113 to the filling height HF. Only after the application of compressed air DL, that is, when the delivery pressure PF is no longer applied at the compressed air interface 270, can the inlet non-return valve 130 be opened again and allow additional flow of cleaning liquid F into the delivery volume area 110.

[0140] Fig. 8A A preferred seventh embodiment of the sensor cleaning device 100 is shown, which has a spring-loaded inlet overflow valve 138 at the compressed air inlet 270, a spring-loaded outlet overflow valve 134 at the cleaning connection 310, and a spring-loaded inlet non-return valve 130. The arrangement and construction of the outlet overflow valve 134 and the inlet non-return valve 130 therefore essentially correspond to the arrangement of the third embodiment shown in FIG.

[0141] By means of spring-loaded inlet overflow valve 138, it is advantageously achieved that compressed air DL provided at compressed air inlet 270 is guided into delivery volume region 110 for the purpose of impinging sensor surface 301 only when delivery pressure PU exceeds a certain minimum value, in particular an inlet overflow pressure PE. Thus, compressed air flows, in particular exhaust air flows, with a relatively low pressure, which have a low cleaning effect, are advantageously ineffective for operating sensor cleaning device 100.

[0142] Figure 8B An eighth preferred embodiment of the sensor cleaning device 100 is shown, Fig. 8A Unlike the seventh embodiment shown in , the sensor cleaning device additionally has a shut-off valve seat 278 at the inlet overflow valve 138, and a pressure chamber 280 for accommodating a compressed air pulse quantity MDI is also arranged between the inlet overflow valve seat 139C and the shut-off valve seat 278.

[0143] If the delivery pressure PF exceeds the inlet overflow pressure PE, the inlet valve body 139B is lifted from the inlet valve seat 139C and moves from the closed inlet overflow valve position PUC into the open inlet overflow valve position PUO, and compressed air DL can flow into the pressure chamber 280. In the open inlet overflow valve position PUO, the inlet valve body 139B abuts against the blocking valve seat 278 and thus prevents compressed air DL from flowing into the delivery volume area 110. If the delivery pressure PF falls below the inlet overflow pressure PE again, the inlet valve body 139B moves back into the closed inlet overflow valve position PUC, and the compressed air pulse quantity MDI flows through the again opened blocking valve seat 278 into the delivery volume area 110 for loading the delivery quantity MF with liquid F in a known manner. Advantageously, the dimensions of the pressure chamber 280 and the delivery volume region 110 are dimensioned such that the liquid located in the delivery volume region 110 can be substantially completely pushed out of the delivery volume region, that is, delivered to the clean interface 310, by means of the generated compressed air pulse quantity MDI. The inlet overflow pressure PE is preferably 6 bar, so that at a delivery pressure PF of greater than or equal to 6 bar, the inlet overflow valve 138 opens. In other embodiments, the inlet overflow pressure PE can be other values, in particular in the range of 2 bar to 12 bar, preferably in the range of 4 bar to 8 bar, particularly preferably in the range of 5 bar to 7 bar.

[0144] Figure 8C A preferred and modified ninth embodiment of the sensor cleaning device 100 according to the invention shows first and second further variants of the inlet overflow valve 138 in combination with a partially matched pressure chamber 280 and delivery volume region 110, which is otherwise similar to the embodiment according to Figure 8B Here, the preferred and modified ninth embodiment of the sensor cleaning device 100 is particularly Figure 8C In the following, only this point will be specifically referred to, wherein it should be understood that for the remainder of the preferred and modified ninth embodiment of the sensor cleaning device 100, Figure 8B The same applies to the description of FIG. 1. In addition, for simplicity, the same reference numerals are used for the same or similar parts or parts having the same or similar functions.

[0145] Figure 8C The sensor cleaning device 100 is shown again; this time, Figure 8C The view (A) of FIG. 1 shows a modified inlet overflow valve 138 . 1 with a blocking valve seat 278 . Figure 8C The view (B) of FIG. 2 shows a modified inlet overflow valve 138 . 1 with a blocking valve seat 278 and a further inlet overflow valve 138 . 2 .

[0146] According to Figure 8B Compared to the embodiment of the sensor cleaning device 100 with the inlet overflow valve 138, Figure 8C In the inlet overflow valve 138.1, in both the variants of view (A) and view (B), a matching piston 139 of the inlet overflow valve 138.1 is provided. Figure 8C It can be seen from the variant of the inlet overflow valve 138.1 shown in the first view (A) of the embodiment that the matching piston 139 of the inlet overflow valve 138.1 with the blocking valve seat 278 is geometrically matched. That is, the first piston surface 139.1 located on the side of the piston 139 facing the compressed air input end 270 is larger than the second piston surface 139.2 located on the side of the piston 139 facing away from the compressed air input end 270.

[0147] This matching is used to keep the piston 139 in the open inlet-relief valve position PUO due to the pressure and area ratio of the first piston surface 139.1 and the second piston surface 139.2 after pressure balancing, that is, after the pressure chamber 280 is completely filled with compressed air from the compressed air input end 270, as shown in FIG. Figure 8C As shown in the views (A) and (B) in FIG. Thus, advantageously, potential fluctuations of the piston 139 are particularly avoided. Although this is unlikely in principle, it cannot be completely ruled out that the piston 139 may be caused by the following reasons: Figure 8B The pressure and surface ratios shown in the embodiments may result in undefined or unexpectedly fluctuating force ratios. Figure 8C The embodiment of the inlet overflow valve 138.1 with the blocking valve seat 278 in the embodiment ensures that even in the case of undefined or undesired fluctuations in the force ratio at the piston 139, the piston 139 remains in the same position due to the pressure and area ratios with respect to the first piston surface 139.1 and the second piston surface 139.2. Figure 8C View (A) and view (B) show the inlet-relief valve positioning PUO in an open state.

[0148] exist Figure 8C In the second variant of the sensor cleaning device 100 shown in the view (B), an assembly of the inlet overflow valve 138 is provided, namely, comprising the aforementioned Figure 8C1 and a further inlet overflow valve 138.2 with a blocking valve seat 278. The further inlet overflow valve 138.2 is arranged between the pressure chamber 280 and the delivery volume region 110, in particular here in the delivery volume region 110. The further inlet overflow valve 138.2 prevents cleaning liquid from flowing into the pressure chamber 280.

[0149] Fig. 9 A preferred embodiment of a pneumatic system 800 with a sensor cleaning device 100 according to the concept of the present invention is schematically shown. The pneumatic system 800 has at least one compressed air consumer 820, which is connected to the compressed air input 270 of the sensor cleaning device 100 via a compressed air supply line 702 for providing compressed air DL. In particular, as shown here, the compressed air supply line 702 can be configured as an exhaust line 703, which is connected to the exhaust interface 3 of the compressed air consumer 820 for providing exhaust compressed air DLE. Alternatively or additionally, as indicated by the dashed line here, the compressed air input 270 can be pneumatically connected to the working interface 2 of the compressed air consumer 820 via a compressed air supply line 702 configured as a working compressed air line 704, for providing working compressed air DLA. Also alternatively or additionally, as indicated by the dashed line here, the compressed air input end 270 can be pneumatically connected to a reserve interface 1 of a compressed air source 600, such as a compressed air reserve container 601 and / or a compressor 602, via a compressed air supply line 702 constructed as a reserve compressed air line 705, in order to provide reserve compressed air DLV.

[0150] As indicated by the dashed line here, the compressed air consumer 820 can be designed as an air spring arrangement 730 with at least one air spring 732, or as a brake system 708, in particular a parking brake system 710 with at least one parking brake cylinder 722 and / or a service brake system 712 with at least one service brake cylinder 728, or as a pneumatic steering axle lock 740 or as an anti-theft lock 742 or as a container locking system 744, or as a lifting axle 750 with at least one lifting bag 752. Other compressed air consumers 820 or combinations of the above-mentioned compressed air consumers 820 with each other or with other compressed air consumers 820 are also possible.

[0151] The compressed air consumer 820 has an electromagnetic switching valve 290 which can be controlled electrically as a function of an electrical switching signal S1 in order to controllably provide the compressed air inlet 270 with compressed air DL.

[0152] The liquid tank 660 is connected to the liquid input 680 of the sensor cleaning device 100 via a liquid supply line 612. In other embodiments, as shown above, the sensor cleaning device 100 can also be arranged partially or completely inside the liquid reservoir 660 and / or connected to the liquid reservoir as a whole. Via the cleaning interface 310, at least one cleaning nozzle 320 is connected to the sensor cleaning device 100 in a fluid-conducting manner in order to receive compressed air DL and / or liquid F and / or spray mixture GS and guide it to the sensor surface 301 of the sensor 300 for cleaning purposes. The sensor 300 is preferably configured as an optical sensor 302, particularly preferably as shown here as a camera 304.

[0153] Preferably, compressed air can be provided to the cleaning interface 310 according to the request of the vehicle driver or the system. Therefore, the triggering of the cleaning can be realized particularly simply. For example, this can include actively stepping on the brake to provide compressed air or systematically triggering the action of compressed air.

[0154] Therefore, in a preferred embodiment, cleaning can be triggered, for example by (completely) actuating a compressed air consumer so that part of its working air can be used as compressed air DL for the cleaning system; for example by fully actuating the brakes, by (briefly) actuating the lifting bags of a lifting axle, etc.

[0155] Triggering the cleaning by simply “fully pressing the brake” can be relatively easy to implement. It has been shown in particular that this can occur without additional communication between the towing vehicle and the trailer (truck / trailer) of the vehicle 1000 and the driver can conveniently control it.

[0156] For example, technically, it is theoretically possible to use the brake pressure directly as compressed air or to sense the brake pressure from the trailer via an electronic brake system (EBS system). The EBS system would recognize a complete actuation of the brake by the driver as a request to trigger cleaning and would itself actuate a corresponding compressed air valve connected to the compressed air inlet 270 .

[0157] List of reference numerals (part of the description)

[0158] 1 Reserve interface

[0159] 2Working interface

[0160] 3 Exhaust interface

[0161] 100 sensor cleaning equipment

[0162] 110 Delivery volume area

[0163] 112 container wall

[0164] 113 delivery cavity

[0165] 114 End side of the delivery volume area

[0166] 114A First end side of the delivery volume region

[0167] 114B Second end side of the delivery volume region

[0168] 116 Immersion Tube

[0169] 116A immersion pipe port

[0170] 117 Immersion pipe interface

[0171] 118 transport channel

[0172] 119A The first side of the conveying channel

[0173] 119B The second side of the conveying channel

[0174] 130 Inlet Check Valve

[0175] 131A Liquid-Inlet Valve Spring

[0176] 131B Liquid-Inlet Valve Body

[0177] 131C Liquid-Inlet Valve Seat

[0178] 134 outlet relief valve

[0179] 135A outlet valve spring

[0180] 135B outlet valve body

[0181] 135C outlet valve seat

[0182] 138 Inlet relief valve

[0183] 138.1, 138.2 Variants of the inlet pressure relief valve, further inlet pressure relief valves

[0184] 139 Modified inlet relief valve piston

[0185] 139.1 The first piston surface on the side facing the compressed air input end 270

[0186] 139.2 The second piston surface on the side facing away from the compressed air input end 270

[0187] 139A Inlet valve spring

[0188] 139B Inlet valve body

[0189] 139C Inlet valve seat

[0190] 270 Compressed air input

[0191] 272 Compressed air branch

[0192] 278 Blocking valve seat

[0193] 280 Pressure Chamber

[0194] 290 Solenoid Switching Valve

[0195] 294 Liquid Level Sensor

[0196] 300 sensors

[0197] 301 sensor surface

[0198] 302 optical sensor

[0199] 304 cameras

[0200] 310 Cleaning Interface

[0201] 320 Cleaning Nozzle

[0202] 600 Compressed air source

[0203] 601 Compressed air storage container

[0204] 602 compressor

[0205] 610 Nozzle Line

[0206] 612 Liquid Supply Line

[0207] 660 Liquid Storage Tank

[0208] 669 tank wall

[0209] 670 The lower area of ​​the liquid storage tank

[0210] 672 Upper area of ​​liquid storage tank

[0211] 680 Liquid input

[0212] 700 Electronic Control Unit

[0213] 702 Compressed air supply line

[0214] 703 exhaust line

[0215] 704 working compressed air line

[0216] 705 Reserve Compressed Air Line

[0217] 707 Electric Line

[0218] 708 Braking System

[0219] 710 parking brake system

[0220] 712 Service Braking System

[0221] 722 parking brake cylinder

[0222] 728 Service Brake Cylinder

[0223] 730 Air Spring Facility

[0224] 732 Air Spring

[0225] 734 Air Spring Valve

[0226] 740 Steering shaft lock

[0227] 742 anti-theft lock

[0228] 744 container locking system

[0229] 750 lifting axle

[0230] 752 lifting bag

[0231] 800 Pneumatic System

[0232] 820 Compressed air consumer

[0233] 1000 vehicles

[0234] 1006 trailer

[0235] 1007 tail area

[0236] A Longitudinal axis

[0237] AF conveying distance

[0238] AL longitudinal axis

[0239] AQ cross-sectional area

[0240] BR loading direction

[0241] DL Compressed Air

[0242] DLA Working Compressed Air

[0243] DLD throttling air flow

[0244] DLE exhaust compressed air

[0245] DLV Reserve Compressed Air

[0246] FLiquid

[0247] FE inlet spring force

[0248] FEF Liquid - Inlet Spring Force

[0249] FR conveying direction

[0250] FS outlet spring force

[0251] G-Gravity

[0252] GS spray mixture

[0253] HF filling height

[0254] HFM maximum filling height

[0255] HFZ conveying height

[0256] HT tank height

[0257] MDI compressed air pulse volume

[0258] MF conveying capacity

[0259] PE inlet overflow pressure

[0260] PF delivery pressure

[0261] PU outlet overflow pressure

[0262] PUC inlet-relief valve positioning

[0263] PUO inlet-relief valve positioning

[0264] S1 electrical switching signal, electronic switching signal

[0265] S2 electrical level signal, electronic level signal

[0266] USurrounding Environment

Claims

1. A sensor cleaning device (100) for a vehicle (1000), the sensor cleaning device being configured for cleaning at least one sensor surface (301) of a sensor (300), wherein: The sensor cleaning device (100) comprises: - a compressed air input (270) configured to receive compressed air (DL), - a liquid input (680) configured to receive a liquid (F), - a cleaning interface (310) configured to provide a liquid (F) and / or compressed air (DL), It is characterized by having - a delivery volume region (110) which is designed to accommodate a liquid (F) and is connected in a fluid-conducting manner to the compressed air inlet (270), the liquid inlet (680) and the cleaning interface (310) in such a way that: - by applying compressed air (DL) to the compressed air inlet (270), the liquid (F) is conveyed in a conveying direction (FR) to the cleaning connection (310), wherein: The delivery volume region (110) is designed to bring the compressed air (DL) into pressure-transmitting contact with the liquid (F), in particular direct and / or phase-boundary contact, for the delivery of the liquid (F).

2. The sensor cleaning device (100) according to claim 1, characterized in that The delivery volume region (110) is designed to accommodate a delivery volume (ML) of a liquid (F), wherein: - By applying compressed air (DL) to the compressed air inlet (270), the delivery quantity (MF) is delivered in a delivery direction (FR) to the cleaning connection (310).

3. The sensor cleaning device (100) according to claim 1 or 2, characterized in that have A pneumatic separation means, in particular an inlet non-return valve (130), arranged at the liquid inlet (680) of the delivery volume region (110), which opens in the delivery direction (FR) and blocks against the delivery direction (FR).

4. The sensor cleaning device (100) according to any one of claims 1 to 3, characterized in that have An outlet overflow valve (134) arranged at the clean interface (310) of the delivery volume region (110), which opens in the delivery direction (FR), preferably against an outlet spring force (FS) of a valve spring (135A), and blocks against the delivery direction (FR).

5. The sensor cleaning device (100) according to any one of the preceding claims, characterized in that have An inlet pressure relief valve (138) arranged at a compressed air inlet (270) of the delivery volume region (110) which opens in the direction of action (BR) of the compressed air (DL) and blocks action counter to the action direction (BR), the inlet pressure relief valve preferably being spring-loaded.

6. The sensor cleaning device (100) according to any one of the preceding claims, characterized in that - the compressed air inlet (270) has a blocking valve seat (278) which can be closed by the inlet overflow valve (138) depending on the inlet overflow valve position (PU); and - A pressure chamber (280) is pneumatically connected between the inlet overflow valve (138) and the shut-off valve seat (278), the pressure chamber being designed to receive a compressed air pulse quantity (MDI) from the compressed air input (270) when the inlet overflow valve (138) is in an open inlet overflow valve position (PUO) and to supply the compressed air pulse quantity (MDI) to the delivery volume region (110) via the shut-off valve seat (278) when the overflow valve (138) is in a closed overflow valve position (PUC).

7. The sensor cleaning device (100) according to any one of claims 1 to 6, characterized in that: - the delivery volume region (110) is pneumatically disconnected from the storage region, in particular the liquid storage tank (660), by means of a pneumatic separation element at the liquid inlet (680), in particular an inlet non-return valve (130); and / or - A storage area, in particular a liquid storage tank (660), is or can be connected to the liquid inlet (680) in a fluid-conducting manner.

8. The sensor cleaning device (100) according to any one of the preceding claims, characterized in that The delivery volume region (110) is formed remote from the storage region and downstream of the pneumatic separation means at the liquid inlet (680).

9. The sensor cleaning device (100) according to any one of the preceding claims, characterized in that The delivery volume region (110) is arranged in the liquid tank (660) or projects into the liquid tank (660), wherein preferably, The liquid inlet (680) is arranged in the lower region (670) of the liquid storage tank (660).

10. The sensor cleaning device (100) according to any one of the preceding claims, characterized in that The compressed air inlet (270) and / or the compressed air branch (272) are arranged in or at the liquid tank (660), preferably in the tank wall (669), and the liquid inlet (680) is arranged in or at the delivery volume region (110), preferably in the container wall (112).

11. The sensor cleaning device (100) according to any one of the preceding claims, characterized in that The compressed air inlet (270) and / or the liquid inlet (680) and / or the cleaning connection (310) are arranged at or in the delivery volume region (110).

12. The sensor cleaning device (100) according to any one of the preceding claims, characterized in that The compressed air inlet (270) is arranged at a distance (AF) from the cleaning interface (310) with respect to the delivery direction (FR) and / or the longitudinal axis (AL) of the delivery volume area (110), preferably arranged opposite the cleaning interface (310) with respect to the delivery volume area (110) and / or the delivery direction (FR).

13. The sensor cleaning device (100) according to any one of the preceding claims, characterized in that - the outlet relief valve (134) is spaced apart from the inlet check valve (130) by a delivery height (HFZ) in the direction of gravity (G); and / or - having an electromagnetic switching valve (290) arranged at the compressed air inlet (270), which is designed to controllably act on the compressed air inlet.

14. The sensor cleaning device (100) according to any one of the preceding claims, characterized in that - having a matching inlet overflow valve (138.1), which has a matching piston (139) associated with the shut-off valve seat (278), wherein a first piston surface (139.1) on the side of the piston (139) facing the compressed air inlet (270) is larger than a piston surface (139.2) on the side of the piston (139) facing away from the compressed air inlet (270), and / or The assembly having an inlet overflow valve (138), in particular a matching inlet overflow valve (138.1), has a further inlet overflow valve (138.2) between the pressure chamber (280) and the delivery volume region (110), in particular in the delivery volume region (110).

15. A pneumatic system (800) for a vehicle (1000), the pneumatic system comprising: - A sensor cleaning device (100) according to any of the preceding claims and at least one sensor (300) having a sensor surface (301).

16. The pneumatic system (800) according to claim 15, characterized in that have - A compressed air consumer (820), wherein preferably, the exhaust port (3) of the compressed air consumer (820) is connected or connectable to the compressed air input (270) for receiving exhaust compressed air (DLE) as compressed air (DL), or preferably, the working port (2) of the compressed air consumer (820) is connected or connectable to the compressed air input (270) for receiving working compressed air (DLA) as compressed air (DL).

17. A vehicle (1000), preferably a commercial vehicle (1002) or a passenger vehicle (1004) or a trailer (1006), comprising a sensor cleaning device (100) according to any one of claims 1 to 14 or a pneumatic system (800) according to claim 15 or 16.

18. A method for operating a sensor cleaning device (100) according to any one of claims 1 to 14, the method comprising the following steps: - the delivery volume region ( 110 ) is preferably automatically filled with liquid (F) from a liquid storage tank ( 660 ) ​​via an inlet non-return valve ( 130 ), - applying compressed air (DL) to the liquid (F), which is in pressure-transmitting contact with the liquid (F), in particular direct contact and / or forming a phase boundary, - supplying the cleaning connection (310) with pressurized liquid (F), in particular also supplying the cleaning connection (310) with compressed air (DL), preferably subsequently or simultaneously supplying the cleaning connection (310) with compressed air (DL).

19. The method according to claim 18, characterized in that The following steps are involved: - directing a liquid (F), preferably a delivery quantity (MF) and / or compressed air (DL) onto a sensor surface (301) of a sensor (300), - determining a waiting time period (TW) which elapses between the actuation of the electromagnetic switching valve (290) for the controlled application of compressed air (DL) to the liquid (F) and the impact of the liquid (F) on the sensor surface (301), and / or - determining, by means of the sensor (300), a loading time period (TB) during which the sensor surface (301) is loaded with the liquid (F), and - determining a filling height (HF) of the liquid (F) in the liquid tank (660) and / or in the delivery volume region (110) as a function of the waiting time period (TW) and / or the loading time period (TB).

20. The method according to claim 18 or 19, characterized in that The following steps are involved: - controlling a compressed air consumer (820), preferably actuating the compressed air consumer (820) to provide the sensor cleaning device (100), preferably at a compressed air inlet (270) of the sensor cleaning device (100), with working compressed air (DLA) for applying pressure to a liquid (F).

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