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

Abstract

The invention relates to a sensor cleaning device (100) for a vehicle (1000), designed for cleaning at least one sensor surface (301) of a sensor (300), wherein the sensor cleaning device (100) comprises: a pressurised air inlet (270) designed for receiving pressurised air (DL); a fluid inlet (680) designed for receiving fluid (F); a cleaning connection (310) designed for providing the fluid (F) and / or the pressurised air (DL). According to the invention, a conveyed volume region (11) is provided in the sensor cleaning device (100), which is design to receive the fluid (F) and which is fluidically connected to the pressurised air inlet (270), the fluid inlet (680) and the cleaning connection (310) in such a way that the fluid (F) is conveyed in a conveying direction (FR) to the cleaning connection (310) by applying the pressurised air inlet (270) with pressurised air (DL), wherein the conveyed volume region (110) is designed in such a way that, for the purpose of conveying the fluid (F), the pressurised air (DL) is in contact with the fluid (F) in particular directly and / or in a phase-bounary-forming, pressure-transmitting manner.

Description

[0001] Sensor cleaning device, pneumatic system, vehicle, method for operating a sensor cleaning device

[0002] The invention relates to a sensor cleaning device according to the preamble of claim 1. The invention further relates to a pneumatic system, a vehicle, and a method for operating a sensor cleaning device.

[0003] Sensor cleaning devices for vehicles are widely known. A sensor cleaning device can be used to clean surfaces on a vehicle, particularly sensor surfaces, using at least one cleaning fluid, particularly liquid and / or compressed air.

[0004] By cleaning sensor surfaces on the vehicle, especially regularly, it can be achieved that sensors are less contaminated and therefore function more reliably. A clean sensor surface thus advantageously increases the reliability of driver assistance functions and / or semi-autonomous and / or autonomous driving functions of a vehicle. The safety of the vehicle, its occupants, and other road users is thus advantageously increased by a sensor cleaning device.

[0005] There are already generally advantageous sensor cleaning devices of this type.For example, 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 that holds a cleaning liquid, a pump that supplies the cleaning liquid under pressure inside the tank, a high-pressure air generation unit that generates high-pressure air, a first discharge opening that sprays the cleaning liquid toward a cleaning surface of the object to be cleaned, a second discharge opening that sprays the high-pressure air toward the cleaning surface, and a controller and a vehicle control ECU that control the spraying of the cleaning liquid and the spraying of the high-pressure air; and the controller and the vehicle control unit perform a control to initiate the spraying of the high-pressure air from the second discharge opening after the spraying of the cleaning liquid from the first discharge opening has been initiated.

[0006] DE 103 32 939 B4 also describes a device for cleaning a front area which is located in front of a distance sensor installed in a vehicle, in particular a commercial vehicle, wherein the front area can be pressurized with compressed air which is supplied via a line from at least one compressed air source present in the vehicle, wherein the compressed air supply is controlled as a function of certain time intervals during vehicle operation.

[0007] DE 10 2018 126 091 A1 describes a sensor cleaning device for selectively applying a first medium to a surface, comprising: a high-pressure accumulator designed to store the first medium under a storage pressure, a pulse nozzle designed to pulse the surface with the first medium under the storage pressure, a switching valve having a nozzle connection and a high-pressure accumulator connection designed to selectively establish a first connection between the high-pressure accumulator and the pulse nozzle, and a feed connection for establishing a second connection of the high-pressure accumulator to a first medium source.In the sensor cleaning device described therein, it is provided that the high-pressure accumulator and the switching valve are structurally integrated in a storage valve module, wherein the switching valve is designed as a solenoid valve, connecting between the first and second connections at the high-pressure accumulator connection subject to the accumulator pressure. DE 10 2019 125 970 A1 describes a sensor cleaning system for cleaning sensors, in which a switching unit is configured such that a sensor can be cleaned via at least one nozzle line with a cleaning fluid emerging from at least one nozzle and / or a cleaning gas emerging from at least one nozzle. The switching unit plays a central role and comprises switching valves controllable by a control unit. One embodiment provides for a gas reservoir to be arranged in one container and a liquid reservoir to be arranged in another container.A storage line is arranged between the two containers, via which the two containers are connected to one another. In this case, an additional switching unit between the containers is advantageous. A more compact design of the sensor cleaning system can be achieved by storing the cleaning liquid and the cleaning gas in a common container. The cleaning liquid and the cleaning gas are directly adjacent to one another. When the cleaning gas, which is located above the cleaning liquid in particular, is compressed, the cleaning liquid is simultaneously pressurized by the cleaning gas, so that ultimately both the cleaning liquid and the cleaning gas are pressurized. A switching unit between the liquid reservoir and the gas reservoir is then no longer necessary. However, in order to fill the cleaning liquid under pressure, the container must first be vented.The reason for this is that the containers of DE 10 2019 125 970 A1 are each designed as storage units for holding the cleaning liquid and the cleaning gas.

[0008] Despite these fundamentally advantageous approaches, sensor cleaning devices still require improvement, particularly with regard to the simplest possible design and / or energy-efficient, effective sensor cleaning.

[0009] It would therefore be desirable to improve sensor cleaning devices, particularly with regard to low equipment costs and / or efficient use of energy and / or cleaning fluids. This is where the invention comes in, the object of which is to provide an improved device and an improved method that, in particular, enable a simplified structure and / or improved efficiency with regard to the required cleaning fluids 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 improved in this regard are to be provided.

[0010] The object relating to the sensor cleaning device is achieved by the invention in a first aspect with a sensor cleaning device of claim 1.

[0011] The invention relates to a sensor cleaning device for a vehicle, designed to clean at least one sensor surface of a sensor, wherein the sensor cleaning device comprises: a compressed air inlet, designed to receive compressed air, a liquid inlet, designed to receive liquid, and a cleaning connection, designed to provide the liquid and / or the compressed air.

[0012] According to the invention, the sensor cleaning device is provided with a delivery volume area which is designed to receive the liquid.

[0013] The displacement area is fluidically connected to the compressed air inlet, the liquid inlet, and the cleaning connection. Specifically, the displacement area is formed as part of a pneumatic connection.

[0014] The delivery volume area is connected in a fluid-conducting manner to the compressed air inlet, the liquid inlet and the cleaning connection in such a way that the liquid is conveyed in a conveying direction to the cleaning connection by applying the compressed air to the compressed air inlet, wherein the delivery volume area is designed in such a way that the compressed air for conveying the liquid is in a pressure-transmitting contact with the liquid, in particular direct and / or forming a phase boundary.

[0015] In general, pressure-transmitting contact can also be effected via a pneumatic means or a pneumatic actuator - this can, for example, preferably be a check valve.

[0016] However, direct contact between the liquid and compressed air is preferred – in other words, direct pressure-transmitting contact with the liquid; this can, for example, preferably be a membrane between the liquid and compressed air.

[0017] In a particularly preferred embodiment, the pressure-transmitting contact between the compressed air and the liquid is defined as contact with the liquid that forms a phase boundary; that is, a situation where the compressed air and the liquid are in direct contact without any separating medium between them. In this respect, this embodiment also establishes direct pressure-transmitting contact that forms a phase boundary.

[0018] The invention is based on the finding that cleaning with liquid is generally advantageous, as it allows, in particular, contaminants to be softened and washed away. The invention also includes the finding that a simple design of a sensor cleaning device is advantageous, as this can save costs and weight in the vehicle. In particular, additional pumps and similar means for conveying liquid lead to increased costs, weight, and installation space, and increase the complexity and susceptibility to maintenance of the sensor cleaning device.

[0019] The invention has surprisingly recognized that a pump or similar conveying means can be dispensed with for conveying liquid for cleaning if a conveying volume range is used which is designed such that compressed air for conveying the liquid is in direct, pressure-transmitted contact with the liquid.

[0020] This means that the delivery volume range is designed in such a way that the compressed air provided at the compressed air inlet can contact the liquid and consequently transfer a pressure, in particular a delivery pressure, to the liquid.

[0021] To operate such a sensor cleaning device, only a compressed air source and a liquid storage tank are required; the delivery volume region is particularly and advantageously formed distally from a storage region, downstream of a pneumatic separating means at the liquid inlet.

[0022] In particular, it may be sufficient for the fluid storage tank to provide the fluid without pressure and / or by gravity, since the actual pumping process to the cleaning port or to a sensor surface to be cleaned occurs via the application of compressed air in the pumping volume area. The pumping direction leads from the fluid inlet through the pumping volume area to the cleaning port.

[0023] Advantageous further developments of the invention can be found in the dependent claims and specify in detail advantageous possibilities for realizing the concept explained above within the scope of the task and with regard to further advantages.

[0024] Within the scope of a preferred development, it is provided that the liquid inlet and / or the compressed air inlet and / or the cleaning connection are arranged on or in the delivery volume area, preferably in a 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 area in a fluid-conducting manner via a hose, a pipe, or a similar line. The delivery volume area itself can be formed, so to speak, as part of a pneumatic connection and, in this sense, also be designed to be fluid-conducting according to the concept of the invention.

[0025] It is preferably provided that the delivery volume area is designed to receive a delivery quantity of the liquid, wherein the delivery quantity is conveyed by applying the compressed air to the compressed air inlet in a conveying direction to the cleaning connection.

[0026] It has proven particularly advantageous to arrange a pneumatic separating means at the fluid inlet of the conveying volume area. Particularly advantageously, the pneumatic separating means is designed in a comparatively simple manner as an inlet check valve. The pneumatic separating means is advantageously configured to open in one conveying direction and to close in the opposite direction. Preferably, the sensor cleaning device comprises an inlet check valve arranged at the fluid inlet, which opens in one conveying direction and closes in the opposite direction.

[0027] It has further proven advantageous for the delivery volume region to be pneumatically decoupled from a storage region, in particular from a liquid storage tank, by a pneumatic separating means at the liquid inlet, in particular an inlet check valve. The delivery volume region is thus preferably formed distally from the storage region, downstream of the separating means at the liquid inlet.

[0028] The aforementioned refinements, in particular, enable a more or less "intelligent"—i.e., automatic—filling of the delivery volume range. This means that the delivery volume range is automatically refilled, for example, immediately before and / or after a cleaning process.

[0029] This has particular advantages over the aforementioned prior art, where an entire reservoir may be pressurized. However, the delivery volume range according to the concept of the invention, and in particular according to one of the aforementioned developments, is advantageously formed pneumatically separated from a reservoir; as if it were only a smaller partial volume that is required for cleaning and that can be properly and automatically pressurized for this purpose. The delivery volume range is formed, so to speak, as part of a pneumatic connection and, in this sense, also carries fluids according to the concept of the invention.

[0030] The sensor cleaning device preferably comprises an outlet overflow valve arranged at the cleaning connection, which opens in one conveying direction, preferably against the outlet spring force of a valve spring, and closes against the conveying direction. By having an inlet check valve and preferably additionally an outlet overflow valve, the principle of a lock can be advantageously implemented. This means that liquid flows, in particular, independently into the conveying volume region via the inlet check valve. However, upon subsequent application of compressed air at the compressed air inlet, it does not flow back due to the blocking of the inlet check valve. Thus, the conveyed quantity of liquid in the conveying volume region is forcibly directed out of the conveying volume region via the cleaning connection.In other words, an inlet check valve prevents the fluid in the discharge volume range from flowing back into the fluid storage tank when compressed air is applied to the compressed air inlet.

[0031] After the flow rate has left the flow volume range, only compressed air is supplied to the cleaning connection as long as compressed air is still present at the compressed air inlet and the inlet check valve is thus closed. This ensures that only a defined amount of fluid, namely the flow rate, is used per cleaning process or per application of compressed air to the compressed air inlet. This allows the amount of fluid to be portioned independently of the amount of compressed air. Continuous application of compressed air after the flow rate has passed through the cleaning connection can also automatically dry the sensor surface once the flow rate of fluid has been directed onto it.

[0032] Preferably, the inlet check valve is designed to enable automatic filling of a delivery volume range with a delivery volume of a liquid from a liquid storage tank. Preferably, the inlet check valve is not spring-loaded. In other developments, the inlet check valve can have a liquid inlet valve spring and thus be spring-loaded with a defined liquid inlet spring force.

[0033] With a spring-loaded inlet check valve, it can be advantageously achieved that if the pressure of the liquid in the liquid storage tank falls below a minimum, for example because the liquid in the liquid storage tank has fallen below a minimum filling level, no more liquid can enter the delivery volume area on its own.

[0034] However, in an alternative variant it is preferred that the spring of the inlet check valve is set differently. The inlet check valve or similar pneumatic separating means is preferably spring-loaded in such a way that the spring opens it, even when the tank volume is very low and therefore also when the fluid pressure from the tank is low. This can advantageously ensure that even when the tank is almost empty, a residual quantity still flows through the valve, which is open by default, into the delivery volume area. The valve would only then close when pressure is applied via the compressed air inlet - the compressed air then pushes the check valve closed against its spring force; i.e. the check valve is also closed against its spring force under the influence of the compressed air.

[0035] Preferably, the liquid inlet and / or the inlet check valve are arranged in a lower region of the liquid storage tank. Preferably, the liquid inlet and / or the inlet check valve are arranged below the liquid storage tank in the direction of gravity. Preferably, the liquid inlet and / or the inlet check valve are fluidly connected to the liquid storage tank via a liquid supply line.

[0036] The invention is further developed by an inlet overflow valve arranged at the compressed air inlet, which opens in the direction of the compressed air's application and closes against the application direction, and which is preferably spring-loaded. Such an inlet overflow valve advantageously enables compressed air applied to the compressed air inlet to only be effective for the delivery volume range and for cleaning 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 a lower pressure, which are caused, for example, by certain venting processes and whose pressure would be insufficient for effective cleaning or conveying the fluid, can be disregarded.

[0037] In preferred embodiments, the outlet overflow valve is spring-loaded and has an outlet valve spring. A spring-loaded outlet overflow valve can advantageously prevent fluid from inadvertently escaping through the outlet overflow valve when no compressed air is being applied to the compressed air inlet.

[0038] Preferably, the outlet overflow valve and / or the inlet check valve and / or the inlet overflow valve are formed as a piston valve, preferably with an integrated spring element. Preferably, at least two of the outlet overflow valve and the inlet check valve and the inlet overflow valve are constructed identically to advantageously reduce the complexity of the sensor cleaning device.

[0039] In a preferred development, it is provided that the compressed air inlet has a shut-off valve seat that can be closed by the inlet overflow valve depending on an inlet overflow valve position, and a pressure chamber is pneumatically connected between the inlet overflow valve and the shut-off valve seat, which pressure chamber is designed to receive a compressed air pulse quantity from the compressed air inlet when the inlet overflow valve is in an open inlet overflow valve position, and to provide the compressed air pulse quantity to the delivery volume region via the shut-off valve seat when the overflow valve is in a closed overflow valve position. By means of such an arrangement of a shut-off valve seat and a pressure chamber, a compressed air pulse can advantageously be generated, even when a previously prolonged compressed air application at the compressed air inlet is terminated, in particular is no longer present.The compressed air pulse in the form of the compressed air pulse quantity is advantageously also transferred in a pulse-like manner to the flow rate or the liquid, which is then provided in a pulse-like manner at the cleaning connection or at least one cleaning nozzle. In this respect, it is advantageous that the actual cleaning only begins when the compressed air supply to the compressed air inlet is removed; in other words, the actual cleaning begins with the opening of the spear valve seat.

[0040] Such an arrangement of a shut-off valve seat and a pressure chamber also enables the provision of a constantly constant compressed air pulse quantity in terms of both its quantity and its pressure, regardless of the delivery pressure and the duration of the compressed air supply to the compressed air inlet.

[0041] In addition, this makes it possible to tap the working air of a compressed air consumer in parallel to serve as a compressed air source; this is possible because the design of the delivery volume range allows only a defined amount of compressed air (the compressed air pulse quantity) to flow in and thus the working compressed air of the compressed air consumer does not flow out continuously via the sensor cleaning unit during its operation.

[0042] Thus, theoretically, the service brake's working air could also be used for sensor cleaning, and cleaning could be triggered by applying the brake. Preferably, the inlet overflow valve can only open above a certain brake pressure. Sensor cleaning can then advantageously be achieved by applying the service brake above a minimum pressure.

[0043] An improved cleaning effect can also be achieved by applying pulsed pressure to the sensor surface.

[0044] The invention is further developed by a liquid storage tank that is connected or connectable to the liquid inlet in a fluid-conducting manner. The liquid storage tank and the sensor cleaning device can preferably be formed in an integrated manner, particularly preferably in one piece.

[0045] Within the scope of a preferred development, it is provided that the delivery volume region is arranged in the liquid storage tank or protrudes into the liquid storage tank, preferably in such a way that the liquid inlet is arranged in a lower region of the liquid storage tank. In particular, the lower region is that part of the liquid storage tank that lies in the lower 20%, preferably in the lower 10%, particularly preferably in the lower 5% of the tank height, i.e., a vertical extension of the liquid storage tank.

[0046] The invention is further developed in that the compressed air inlet and / or a compressed air branch is arranged in or on the liquid storage tank, preferably in a tank wall, and the liquid inlet is arranged in or on the delivery volume area, preferably in a container wall.

[0047] The delivery volume region preferably comprises a dip tube which projects into the liquid storage tank and comprises the liquid inlet, and a delivery passage arranged outside the liquid storage tank, which delivery passage comprises the compressed air inlet on a first side and the cleaning connection on an opposite second side, wherein the dip tube is fluid-conductingly connected to the delivery passage at a dip tube connection which lies between the first side and the second side. Particularly preferably, the dip tube is arranged approximately in the direction of gravity, so that the liquid inlet is arranged in a lower region of the liquid storage tank. Particularly preferably, the delivery passage comprises a compressed air branch between the compressed air inlet and the dip tube connection, which connects the delivery passage in a fluid-conducting, in particular pneumatic, connection to the liquid storage tank, in particular to an upper region of the liquid storage tank.The upper region of the liquid storage tank is particularly preferably free of liquid, i.e. a maximum fill level of the liquid storage tank is below the upper region. The compressed air branch can advantageously be used to pressurize the liquid in the liquid storage tank with compressed air using a delivery pressure applied to the compressed air inlet, which is then conveyed through the liquid inlet and the dip tube to the dip tube connection. At the dip tube connection, the liquid is taken up in particular by a throttle air stream and conveyed to the cleaning connection. The delivery passage and / or the dip tube connection is particularly preferably designed such that a spray mixture forms at the dip tube connection when it meets the throttle air stream, and this spray mixture is made available at the cleaning connection for at least one cleaning nozzle. A spray mixture is a mixture of air with fine liquid orWater droplets, which can be advantageously directed to the sensor surface via the cleaning nozzle.

[0048] In particular, the compressed air inlet and / or the compressed air branch are arranged in an upper region of the liquid storage tank. In particular, the upper region is that part of the liquid storage tank that lies in the upper 20%, preferably in the upper 10%, particularly preferably in the upper 5% of the tank height, i.e., a vertical extension of the liquid storage tank.

[0049] In preferred developments, it is provided that the compressed air inlet and / or the liquid inlet and / or the cleaning connection are arranged on or in the delivery volume region. Within the scope of a preferred development, it is provided that the compressed air inlet is arranged at a conveying distance from the cleaning connection with respect to the delivery direction and / or a longitudinal axis of the delivery volume region. It is preferably provided that the compressed air inlet is arranged opposite the cleaning connection with respect to the delivery volume region and / or the conveying direction.

[0050] This means, in particular, that the greater the delivery distance, the greater the effective delivery rate of the fluid, preferably with a constant average cross-sectional area of ​​the delivery volume range. It is also possible, additionally or alternatively, to adjust the cross-sectional area of ​​the delivery volume range to structurally change the delivery rate.

[0051] In particular, the delivery volume region has an elongated shape, in particular an aspect ratio such that a ratio of the length along the longitudinal axis to an average diameter is greater than 5.

[0052] Within the scope of a preferred development, it is provided that the outlet overflow valve is spaced apart from the inlet check valve at a delivery height in the direction of gravity. This means in particular that the outlet overflow valve is arranged at a delivery height spaced apart in the direction of gravity below the inlet check valve. In this way, in particular, the capacity of the delivery volume region can be increased by a proportion which is automatically filled with liquid, regardless of the fill level of the liquid storage tank. Preferably, the delivery volume region is arranged substantially vertically, in particular with an approximately vertically arranged longitudinal axis. In particular, the sensor cleaning device comprises a nozzle line which is particularly preferably arranged at least partially parallel to the delivery volume region.

[0053] Preferably, the cleaning connection is arranged above a maximum fill level of the liquid storage tank and / or the discharge volume range. In such developments, an outlet overflow valve can advantageously be omitted.

[0054] In preferred developments, a solenoid valve is provided at the compressed air inlet, which is designed to controllably pressurize the compressed air inlet. The solenoid valve is particularly preferably electrically or electronically controllable. The solenoid valve is preferably a valve of another compressed air consumer in a pneumatic system of a vehicle, which is advantageously designed entirely or partially to provide compressed air at the compressed air inlet of the sensor cleaning device.

[0055] Preferably, the solenoid switching valve is integrated into the sensor cleaning device, in particular in a housing of the sensor cleaning device, or is attached to the housing, preferably flanged.

[0056] In preferred developments, the sensor cleaning device has a fill level sensor which is designed to determine a fill level of the liquid in the liquid storage tank and / or in the delivery volume area. The fill level sensor is preferably arranged in the delivery volume area. A fill level sensor arranged in the delivery volume area is particularly advantageous if the overflow valve is to be dispensed with. The fill level sensor and the magnetic switching valve are preferably connected to an electronic control unit via a common, particularly preferably two-wire, electrical line. The fill level sensor preferably comprises an electrical element which is designed to change its resistance and / or its capacitance and / or its inductance depending on a fill level in the delivery volume area and / or in the liquid storage tank.The electronic control unit is preferably configured to determine such a change in the electrical element of the fill level sensor using electrical test pulses, particularly preferably without switching the solenoid valve. The invention achieves the object in a second aspect by providing a pneumatic system according to claim 15. The pneumatic system for a vehicle comprises: a sensor cleaning device according to the first aspect of the invention and at least one sensor with a sensor surface.

[0057] In a further development of the pneumatic system, the sensor cleaning device is pneumatically connected or connectable to a compressed air source, preferably controllable via a solenoid switching valve.

[0058] A further development of the pneumatic system includes a compressed air consumer. In particular, the compressed air consumer serves a primary purpose different from sensor cleaning.

[0059] Preferably, a vent connection of the compressed air consumer is pneumatically connected or connectable to the compressed air inlet for receiving venting compressed air as compressed air. In such developments of a pneumatic system, venting air, which would otherwise have been discharged unused into the environment, can be used to operate the sensor cleaning device. In particular, developments of such a pneumatic system can be designed without an additional solenoid switching valve, so that the sensor cleaning device is always operated when venting air is present.

[0060] Preferably, a working connection of the compressed air consumer is pneumatically connected or connectable to the compressed air inlet for receiving working compressed air as compressed air. In such developments of a pneumatic system, working compressed air from the compressed air consumer can be used, preferably alternatively or in addition to another use of the working compressed air in the compressed air consumer.

[0061] Preferably, a supply connection of a compressed air source, preferably a compressed air reservoir and / or a compressor, is pneumatically connected or connectable to the compressed air inlet for receiving a supply of compressed air as compressed air. In such developments of a pneumatic system, a solenoid switching valve can be arranged at the supply connection for the controllable provision of the supply of compressed air and / or a compressor can be designed to be controllable in response to an electrical switching signal.

[0062] Preferably, the compressed air consumer is an air spring system with at least one air spring. Preferably, the compressed air consumer is a braking 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.

[0063] Preferably, the compressed air consumer is a pneumatic steering axle lock, an immobilizer, or a container locking system. Preferably, the compressed air consumer is a lifting axle with at least one lifting bellows. However, other compressed air consumers can be used in a pneumatic system according to the second aspect of the invention with a sensor cleaning device according to the first aspect of the invention.

[0064] The invention achieves the object in a third aspect by providing a vehicle according to claim 17. The vehicle is preferably a commercial vehicle, a passenger car, 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.

[0065] The invention achieves the object in a fourth aspect by a method according to claim 18. The inventive method for operating a sensor cleaning device according to the first aspect of the invention comprises the steps:

[0066] - automatic filling of a delivery volume range with a liquid from a liquid storage tank, preferably via an inlet check valve;

[0067] - Pressurizing the fluid with compressed air, which is in pressure-transmitting contact with the fluid. The pressure-transmitting contact is, in particular, direct contact between the compressed air and the fluid. Additionally or alternatively, the pressure-transmitting contact forms a phase boundary between the compressed air and the fluid.

[0068] The method for operating the sensor cleaning device further comprises the step:

[0069] - Providing the pressurized fluid at a cleaning connection.

[0070] As a result of the fluid being subjected to compressed air which is in pressure-transmitting contact with the fluid, the pressurized fluid is made available at a cleaning connection.

[0071] In particular, compressed air is also provided at the cleaning connection. The compressed air can preferably be provided subsequently or simultaneously at the cleaning connection. If the compressed air and the liquid are provided simultaneously, a spray mixture of compressed air and liquid is preferably provided.

[0072] Preferably, the compressed air can be provided to a cleaning connection upon request from the vehicle driver or the system. This makes it particularly easy to initiate the cleaning process. For example, this can involve an action such as applying the brake to provide compressed air or a systemic release of compressed air.

[0073] In a preferred development of the method, a delivery volume of the liquid is delivered through the sensor cleaning device, so that the steps are designed as follows: automatically filling a delivery volume area with a delivery volume of a liquid from a liquid storage tank, preferably via an inlet check valve; pressurizing the delivery volume of the liquid with compressed air in direct pressure-transmitting contact; thereby providing the pressurized delivery volume of the liquid, and preferably subsequently or simultaneously providing the compressed air at a cleaning connection.

[0074] In a preferred development of the method, the following steps are provided: directing the liquid, preferably the delivery volume, and / or the compressed air onto a sensor surface of a sensor; determining a waiting period that elapses between the activation of a magnetic switching valve for the controlled application of compressed air to the liquid and impact on the sensor surface, and / or determining an exposure period in which the sensor surface is exposed to the liquid, preferably by means of the sensor to be cleaned itself, and determining a fill level of the liquid in the liquid storage tank and / or in the delivery volume range as a function of the waiting period and / or the exposure period. In such a development, an indirect fill level measurement can be carried out without an additional fill level sensor in that the sensor to be cleaned measures how long it takes after the activation orSwitching of the solenoid switching valve takes until liquid comes out through the cleaning nozzle and / or how much liquid, i.e. how long from the start of the liquid coming out, comes out of the cleaning nozzle.

[0075] In a preferred development of the method, the following step is provided: controlling a compressed air consumer, preferably actuating the compressed air consumer, to provide working compressed air to the sensor cleaning device, preferably at a compressed air inlet of the sensor cleaning device, for pressurizing the fluid. Actuating the compressed air consumer preferably comprises actuating a braking 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 immobilizer or a container locking system, or a lifting axle with at least one lifting bellows. Actuating the compressed air consumer preferably comprises full actuation, particularly preferably providing a maximum working compressed air quantity.Thus, in a preferred embodiment, for example, by (fully) actuating a compressed air consumer, part of its working air can be used as compressed air for the cleaning system or the cleaning can be triggered; e.g., by fully actuating the brake, by (briefly) actuating a lifting bellows of a lifting axle, etc.

[0076] Initiating the cleaning process by simply "fully depressing the brakes" is comparatively easy to implement. In particular, it shows that this can be done without any additional communication between the towing vehicle and the trailer (truck / trailer) of the vehicle 1000, allowing the driver to conveniently control it.

[0077] Technically, the brake pressure could theoretically be used directly as compressed air, or the brake pressure from the trailer could be sensed via an electronic braking system (EBS). This could detect the driver's full application of the brakes as a request, trigger a cleaning cycle, and in turn control the corresponding compressed air valve connected to the compressed air inlet.

[0078] In a preferred development of the method, the following step is provided: venting a compressed air consumer, preferably terminating actuation of the compressed air consumer, to provide venting compressed air to the sensor cleaning device, preferably at a compressed air inlet of the sensor cleaning device, for pressurizing the fluid. Preferably, venting the compressed air consumer comprises 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 immobilizer or a container locking system, or a lifting axle with at least one lifting bellows.

[0079] 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, as particularly set forth in the dependent claims. Therefore, for the development of one aspect of the invention, reference is also made to the developments of the other aspects of the invention.

[0080] Embodiments of the invention will now be described below with reference to the drawings in comparison to the prior art, some of which is also shown. These are not necessarily intended to represent the embodiments to scale; rather, where useful for explanation, the drawings are schematic and / or slightly distorted. With regard to additions to the teachings immediately apparent from the drawings, reference is made to the relevant prior art. It should be noted that many modifications and changes to the form and detail of an embodiment can be made without departing from the general idea of ​​the invention. The features of the invention disclosed in the description, in the drawings and in the claims can be essential for the further development of the invention, both individually and in any combination.Furthermore, all combinations of at least two of the features disclosed in the description, the drawings, and / or the claims fall within the scope of the invention. The general idea of ​​the invention is not limited to the exact form or detail of the preferred embodiment shown and described below, nor is it limited to an object that would be limited compared to the object claimed in the claims. In the case of specified dimensioning ranges, values ​​within the stated limits are also intended to be disclosed as limit values ​​and can be used and claimed as desired.

[0081] Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawing, which shows: Fig. 1 a vehicle in the form of a trailer with a sensor cleaning device according to the concept of the invention,

[0082] Fig. 2 shows a first preferred embodiment of a sensor cleaning device according to the concept of the invention,

[0083] Fig. 2A shows the first preferred embodiment of a sensor cleaning device in the unactuated state according to the concept of the invention,

[0084] Fig. 2B shows the first preferred embodiment of a sensor cleaning device in the actuated state according to the concept of the invention,

[0085] Fig. 3 shows a second preferred embodiment of a sensor cleaning device in a first variant according to the concept of the invention,

[0086] Fig. 3A shows the second preferred embodiment of a sensor cleaning device in a second variant according to the concept of the invention,

[0087] Fig. 3B shows the second preferred embodiment of a sensor cleaning device in a third variant according to the concept of the invention,

[0088] Fig. 4A shows a third preferred embodiment of a sensor cleaning device in an unactuated state according to the concept of the invention,

[0089] Fig. 4B shows a third preferred embodiment of a sensor cleaning device in the actuated state according to the concept of the invention, Fig. 5 shows a fourth preferred embodiment of a sensor cleaning device according to the concept of the invention,

[0090] Fig. 6 shows a fifth preferred embodiment of a sensor cleaning device according to the concept of the invention,

[0091] Fig. 7 shows a sixth preferred embodiment of a sensor cleaning device according to the concept of the invention,

[0092] Fig. 8A shows a seventh preferred embodiment of a sensor cleaning device according to the concept of the invention,

[0093] Fig. 8B shows an eighth preferred embodiment of a sensor cleaning device according to the concept of the invention,

[0094] Fig. 8C shows a first and second further variant of an inlet overflow valve in combination with the partially adapted pressure chamber and the displacement volume range and otherwise the same design as the eighth preferred embodiment according to Fig. 8B for a ninth preferred and varied embodiment of a sensor cleaning device according to the concept of the invention,

[0095] Fig. 9 is a schematic representation of a pneumatic system with a compressed air consumer and a sensor cleaning device according to the concept of the invention.

[0096] Fig. 1 shows a vehicle 1000, in the present case in the form of a trailer 1006, in schematic form. The following description applies analogously and without restriction to any other type of vehicle 1000. However, due to the advantageously simple design of the embodiment of the sensor cleaning device described below, it is particularly advantageously suited for a trailer. Such a trailer 1006 is described below in a preferred embodiment.

[0097] The trailer 1006 has a sensor 300 with a sensor surface 301 in a rear area 1007 for detecting an environment U. The sensor 300 is embodied here as an optical sensor 302 in the form of a camera 304. The trailer 1006 further has a cleaning nozzle 320, which is arranged and oriented in a fixed position with respect to the sensor surface 301 such that it can apply liquid F and / or compressed air DL to the sensor surface 301 for cleaning purposes. For this purpose, the cleaning nozzle 320 is fluid-conductingly connected to a cleaning connection 310 of a sensor cleaning device 100 according to the concept of the invention. The sensor cleaning device 100 comprises a fluid inlet 680, which is fluid-conductingly connected to a fluid storage tank 660.In embodiments, the liquid storage tank 660 can also be designed as a central washing water tank of a vehicle 1000, and thus serve as a reservoir for additional cleaning devices of the vehicle 1000. In particular, water or a liquid containing cleaning additives can be used as the liquid F.

[0098] The sensor cleaning device 100 comprises a compressed air inlet 270, which in this case is pneumatically connected to a compressed air consumer 820 of a pneumatic system 800 of the vehicle 1000. The pneumatic system 800 in this case comprises an air spring system 730 with a number of air springs 732, shown schematically here. The trailer 1006 in this case comprises a solenoid 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 solenoid switching valve 290, compressed air from a compressed air source (not shown in detail here) can be controllably provided to the compressed air inlet 270 as a function of an electronic switching signal S1. In this case, the electronic switching signal S1 is provided by an electronic control unit 700. Fig. 2 shows a first preferred embodiment of a sensor cleaning device 100 according to the concept of the invention.The sensor cleaning device 100 comprises a delivery volume region 110 configured to receive a delivery quantity MF of a liquid F. The delivery volume region 110 comprises a container wall 112 enclosing a defined volume for receiving a delivery quantity MF of the liquid F; this container wall 112 can be configured, for example, as part of a pneumatic connection. The delivery volume region 110 has a liquid inlet 680 for receiving the liquid F from a liquid storage tank 660. An inlet check valve 130 or similar pneumatic separating means is arranged at the liquid inlet 680.

[0099] In the present embodiment, particular care is taken to ensure that the delivery volume region 110 is pneumatically decoupled from a storage region, in particular from a liquid storage tank 660, by a pneumatic separating means at the liquid inlet 680, in particular an inlet check valve 130. Nevertheless, in the present case, a storage region, in particular the liquid storage tank 660, is also connected or connectable to the liquid inlet 680 in a fluid-conducting manner.

[0100] The delivery volume area 110 is thus formed distally from the storage area, downstream of the pneumatic separating agent at the liquid inlet 680.

[0101] The inlet check valve 130 is designed such that it opens in a conveying direction FR and closes against the conveying direction FR, wherein the conveying direction FR extends from the liquid storage tank 660 via the conveying volume region 110 to the cleaning connection 310. This means that liquid F flowing in the direction of the conveying direction FR can pass through the inlet check valve 130 and thus flow from the liquid storage tank 660 into the conveying volume region 110. However, a flow of liquid F from the conveying volume region 110 into the liquid storage tank 660 is not possible. In the present case, the liquid inlet 680 and the conveying volume region 110 are arranged in a lower region 670 of the liquid storage tank 660 with respect to a force of gravity G and a tank height HT, which advantageously enables an independent subsequent flow of liquid F into the conveying volume region 110. The liquid storage tank 660 can be connected directly or via the control unit as shown here.be connected to the delivery volume region 110 via a relatively short liquid supply line 612. The liquid supply line 612 leads into the liquid storage tank 660 via an opening in a tank wall 669. In other embodiments, it is nevertheless possible to arrange the liquid storage tank 660 at a distance from the delivery volume region 110 in the vehicle 1000 via a correspondingly longer liquid supply line 612.

[0102] The delivery volume region 110 further comprises the cleaning connection 310, which is fluidly connected to a cleaning nozzle 320 via a nozzle line 610. An outlet overflow valve 134 with an outlet valve spring 135A and an outlet valve body 135B is arranged at the cleaning connection 310. The outlet overflow valve 134 is designed to open in the delivery direction FR against an outlet spring force FS dependent on the outlet valve spring 135A and to close it against the delivery direction FR. If a delivery pressure PF in the delivery volume area 110 exceeds an outlet overflow pressure PU, the outlet valve body 135B lifts from an outlet valve seat 135C of the outlet overflow valve 134 and thus allows the liquid F and / or the compressed air DL to pass from the delivery volume area 110 in the direction of the nozzle line 610 and the cleaning nozzle 320.A passage of compressed air DL and / or liquid F against the conveying direction FR, i.e., from the nozzle line 610 into the conveying volume area 110, is not possible because the outlet overflow valve 134 then closes. However, if the conveying pressure PF is not present or is only low, the outlet overflow valve prevents the cleaning fluid from flowing out.

[0103] The displacement volume region 110 further comprises a compressed air inlet 270 configured to receive compressed air DL. An inlet overflow valve 138 with an inlet valve spring 139A and an inlet valve body 139B is arranged at the compressed air inlet 270. The inlet overflow valve 138 is configured to open in a direction of application BR, i.e., in a direction into the displacement volume region 110, against an inlet spring force FE dependent on the inlet valve spring 139, and to close against the direction of application BR.

[0104] If a pressure applied to the compressed air inlet 270, in particular the delivery pressure PF, exceeds an inlet overflow pressure PE, the inlet valve body 139B lifts from an inlet valve seat 139C of the inlet overflow valve 138 and thus enables the compressed air DL to flow from the compressed air inlet 270 into the delivery volume area 110. The inlet overflow valve 138 advantageously prevents liquid F from escaping via the compressed air inlet 270, even if a fill level HF of the liquid storage tank 660 exceeds the position of the compressed air inlet 270 with respect to the direction of gravity G.

[0105] In the present case, the delivery volume region 110 has a container wall 112 enclosing an elongated, approximately cylindrical space extending along a longitudinal axis AL. However, in other embodiments, the delivery volume region 110 may have a different, non-cylindrical shape. The liquid inlet 680 and the compressed air inlet 270 are arranged on a first end face 114A of the cylinder or the delivery volume region. The cleaning connection 310 is arranged on a second end face 114B, opposite the first end face 114A and spaced apart from it at a delivery distance AF.

[0106] The sensor cleaning device 100 can advantageously be controlled by applying compressed air DL to the compressed air inlet 270.

[0107] Fig. 2A now shows the first preferred embodiment of a sensor cleaning device in the unactuated state according to the concept of the invention. The delivery volume region 110 contains liquid F of delivery rate MF, which is automatically drawn there from the liquid storage tank 660 by the action of gravity G via the liquid inlet 680 and the inlet check valve 130. The inlet overflow valve 138 is closed in the sensor cleaning device 100 shown in Fig. 2A in the unactuated state; i.e., it blocks under the predominant effect of the inlet valve spring 139A and the inlet overflow pressure PE.

[0108] If the compressed air inlet 270 is now subjected to compressed air DL with a delivery pressure PF that is greater than the inlet overflow pressure PE, the inlet overflow valve 138 opens. Fig. 2B accordingly shows the first preferred embodiment of a sensor cleaning device 100 in the actuated state according to the concept of the invention; ie, the inlet valve body 139B is lifted from the inlet valve seat 139C of the inlet overflow valve 138.

[0109] The compressed air DL comes into direct contact with the fluid F of the delivery rate MF in the delivery volume range 110 and acts upon it. The delivery pressure PF thus acts upon the fluid F of the delivery rate MF in the delivery volume range 110. As a result, the fluid F of the delivery rate MF, subject to the delivery pressure PF, acts against the outlet overflow valve 134, which opens against the outlet spring force FS.

[0110] The inlet check valve 130 blocks the flow of the liquid F at the delivery pressure PF with a delivery rate MF. Consequently, the delivery rate MF of the liquid F is directed via the outlet overflow valve 134 and the nozzle line 610 to the cleaning nozzle 320, and from there to a sensor surface 310 (not shown here).

[0111] The duration of the application of compressed air DL can advantageously be adjusted, in particular via the corresponding control of a solenoid valve 290, which is pneumatically connected to the compressed air inlet 270 and not shown here, so that the application of compressed air DL continues when the delivery rate MF has left the delivery volume range 110. Consequently, after the delivery of the liquid F, further compressed air DL is directed via the delivery volume range 110, the outlet overflow valve 134 and the cleaning nozzle 320 onto the sensor surface 310, thereby drying and / or removing the liquid F from the sensor surface 310.

[0112] Fig. 3 shows a second preferred embodiment of a sensor cleaning device 100 according to the concept of the invention. Unlike the first embodiment shown in Fig. 2, the sensor cleaning device 100 shown here does not include an inlet overflow valve 138 at the compressed air inlet 270.

[0113] Instead, the compressed air inlet 270 is arranged with respect to the liquid storage tank 660 such that a maximum filling height HFM of the liquid storage tank 660, with respect to the direction of gravity G, is always below the compressed air inlet 270.

[0114] The outlet overflow valve 134 can also be arranged closer to the cleaning connection 310 or formed with it; this is shown by the additional or alternative outlet overflow valve 134 shown in dashed lines in Fig. 3. The outlet overflow valve 134 as such or the outlet overflow valve 134 as a separate valve can, in principle, also be dispensed with. Fig. 3A accordingly shows the second preferred embodiment of a sensor cleaning device in a second variant according to the concept of the invention without the inlet overflow valve 138 at the compressed air inlet 270 and without the aforementioned outlet overflow valve 134 as such, in particular without the outlet overflow valve 134 as a separate valve. The embodiment shows a construction on the tank or a design of the delivery volume area 110 with inlet / outlet openings above the liquid storage tank 660; this makes it possible to implement the arrangement shown in Fig.3A can be designed only with the delivery volume range 110 and the inlet check valve 130. Eliminating the outlet overflow valve 134 and the inlet overflow valve 138 is possible if the compressed air inlet 270 and the cleaning connection 310 or their respective inflow / outflow lines are arranged above the liquid fill level of the liquid storage tank 660, preferably above the upper edge of the liquid storage tank 660.

[0115] As a further difference from the first embodiment shown in Fig. 2, the delivery volume region 110 is oriented substantially vertically in the present case. This means that the longitudinal axis AL of the delivery volume region 110 extends substantially in the direction of gravity G. The delivery rate MF in the present case depends on the actual fill level HF of the liquid F in the liquid storage tank 660, since the delivery volume region 110 is also filled with liquid F up to this fill level HF. This is particularly the case since the sensor cleaning device 100 does not have an inlet overflow valve 138 that limits the liquid F.The delivery length AF, which together with a cross-sectional area AQ of the delivery volume area 110 defines the delivery quantity MF, is composed in this case of the filling height HF and a delivery head HFZ, wherein the delivery head HFZ is a distance running in the direction of gravity G between the liquid inlet 680 and the cleaning connection 310 arranged below the liquid inlet 680.

[0116] Fig. 3B shows the second preferred embodiment of a sensor cleaning device in a third variant according to the concept of the invention. In the design shown therein, the simple inlet check valve 130 is arranged at the level of the tank bottom of the liquid storage tank 660 or arranged below it with inlet / outlet lines that extend beyond the tank top edge. This offers the advantage that a cleaning fluid cannot accidentally leak out.

[0117] Fig. 4A shows a third preferred embodiment of a sensor cleaning device 100 in the unactuated state. Like the second embodiment shown in Fig. 3 and Fig. 3A, Fig. 3B, this device has a delivery volume region 110 extending in the direction of gravity G, i.e., 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 fill level HF of the liquid storage tank 660.

[0118] The inlet check valve 130 is structurally identical to the outlet overflow valve 134 and consequently has a liquid inlet valve spring 131A, a liquid inlet valve body 131B, and a liquid inlet valve seat 1310. The inlet check valve 130 is correspondingly configured to actively open in a delivery direction FR by a liquid inlet spring force FEF, so that the state of the liquid F shown in Fig. 4A in the delivery quantity MF is reached (as explained with reference to Fig. 2, Fig. 2A). The inlet check valve 130 is correspondingly configured to block against the delivery direction FR. The outlet valve spring 135A and the liquid inlet valve spring 131A are formed with bending spring elements in the present case.

[0119] In the present third embodiment, the inlet check valve 130 is substantially identical in construction to the outlet overflow valve 134. This advantageously allows an even further reduction in the complexity of the sensor cleaning device 100 to be achieved. Consequently, the outlet overflow 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 overflow valve 134 is designed, analogously to the embodiment shown in Fig. 2B, to block against the conveying direction FR. In particular, the outlet overflow valve 134 is designed, analogously to the embodiment shown in Fig. 2B, to open in a conveying direction FR against an outlet spring force FS. Fig. 4B shows the third preferred embodiment of a sensor cleaning device in the actuated state according to the concept of the invention.

[0120] Fig. 5 shows a fourth preferred embodiment of a sensor cleaning device 100. The sensor cleaning device 100 essentially corresponds to the third embodiment shown in Fig. 4A, Fig. 4B, with the difference that the liquid storage tank 660 is not integrated or integrally connected to the sensor cleaning device 100. Rather, in the embodiment shown here, it is possible to arrange the sensor cleaning device 100 remotely from the liquid storage tank 660. In particular, the liquid inlet 680 of the sensor cleaning device 100 can be fluidly connected to the liquid storage tank 660 by means of a liquid supply line 612 (not shown here).

[0121] Furthermore, Fig. 5 shows an electrically controllable solenoid switching valve 290 arranged at the compressed air inlet 270. The solenoid switching valve 290 is designed to controllably provide compressed air DL at the compressed air inlet 270.

[0122] The sensor cleaning device 100 further comprises a fill level sensor 294 arranged in the delivery volume region 110, which is designed to determine a fill level, in particular the fill level HF, of the liquid F received in the delivery volume region 110 and, depending on the determined fill level HF, to provide a corresponding fill level signal S2, in particular a fill level signal that develops with the fill level HF, for example, a proportional, preferably electrical one. In the present case, the solenoid switching valve 290 is connected to the fill level sensor 294 via an electrical line 707 for receiving the electrical fill level signal S2.

[0123] Preferably, the solenoid switching valve 290 or an electrical or electronic control unit 700 connected to it in a signal-carrying manner is designed to provide compressed air DL at the compressed air inlet 270 when the fill level HF is sufficiently high, in particular by providing an electronic switching signal S1, and / or to stop the provision of compressed air DL when the fill level HF is sufficiently low, in particular by stopping the provision of the electronic switching signal S1. Fig. 6 shows a further, fifth preferred embodiment of a sensor cleaning device 100. In contrast to the first to fourth embodiments shown in Figs. 2 to 5, the embodiment shown here is not based on the principle of a lock with an inlet check valve and an outlet overflow valve.The delivery volume region 110 here comprises a dip tube 116 projecting downward into the liquid storage tank 660 in the direction of gravity G. The liquid inlet 680 is arranged on a first end face 114A located at the bottom in the direction of gravity G. The liquid inlet 680 is arranged in a lower region 670 of the liquid storage tank 660. On a second end face 114B of the dip tube 116 opposite the first end face 114A, the dip tube 116 is fluid-conductingly connected to a delivery passage 118 of the delivery volume region 110.

[0124] The conveying passage 118 is also elongated along a longitudinal axis AL, with a compressed air inlet 270 arranged on a first side 119A and a cleaning connection 310 arranged on an opposite second side 119B. Consequently, a conveying direction FR runs from the first side 119A to the second side 119B.

[0125] Between the first side 119A, i.e., the compressed air inlet 270, and the second side 119B, i.e., the cleaning connection 310, a dip tube connection 117 is arranged in the delivery passage 118, via which dip tube 116 is fluidly connected to the delivery passage 118. The dip tube connection 117 is designed here as a pipe socket curved in the delivery direction FR, whereby liquid F delivered via the dip tube 116 into the delivery passage 118 is accelerated in the direction of the cleaning connection 310. The dip tube connection 117 protrudes into the delivery passage 118 and thus, due to the resulting reduction in the cross-section of the delivery passage 118 to a throttle cross-section AQ, causes a throttling effect for a passing throttle air flow DLD. A compressed air branch 272 is arranged between the first side 119A, i.e. the compressed air inlet 270, and the dip tube connection 117.The compressed air branch 272 connects the delivery passage 118 in a fluid-conducting manner to an upper region 672 of the liquid storage tank 660. In this way, a delivery pressure PF of the compressed air DL provided at the compressed air inlet 270 can be transferred to the liquid F in the liquid storage tank 660. As a result, the liquid F subjected to the delivery pressure PF is guided via the liquid inlet 680 and the dip tube 116 and further via the dip tube connection 117 to the cleaning connection 310, where it is provided for a cleaning nozzle 320 (not shown here).

[0126] With the embodiment shown here, it is also advantageously possible to provide the liquid F and the compressed air DL as a spray mixture GS. The generation of a spray mixture GS can advantageously be achieved by the structural design of the sensor cleaning device 100, in particular a delivery pressure PF and / or a throttle cross-section AQ.

[0127] In particular, because no inlet check valve is provided in the illustrated embodiment, the illustrated sensor cleaning device 100 enables continuous conveyance, in particular as a spray mixture GS, over the duration of the compressed air inlet 270 being pressurized with compressed air DL.

[0128] Fig. 7 shows a sixth preferred embodiment of a sensor cleaning device 100. In contrast to the embodiment shown in Fig. 6, the sensor cleaning device 100 shown here has an inlet check valve 130 which is arranged at the liquid inlet 680 of the delivery volume region 110. The inlet check valve 130 traps a delivery quantity MF of liquid F in the delivery volume region 110, which is made available at the cleaning connection 310 by pressurizing the compressed air inlet 270 with compressed air DL. By connecting the dip tube 116 via the dip tube connection 117 in the delivery passage 118 and thus making the liquid F available, mixing it with a throttle air flow DLD passed through the throttle cross section AQ, to form a spray mixture GS.Furthermore, in addition to the delivery passage 118 and the dip tube 116, the delivery volume area 110 also has a delivery chamber 113 which connects the compressed air branch 272 to the dip tube 116, namely to a dip tube mouth 116A arranged in the lower region 670 of the liquid storage tank 660, and thus shields it from the rest of the liquid tank 660. Liquid F from the liquid tank 660 can thus reach the delivery volume area 110 exclusively via the inlet check valve 130. In particular, a defined delivery quantity MF can be delivered by applying compressed air DL. When the compressed air inlet 270 and thus the compressed air branch 272 are pressurized with compressed air DL, the inlet check valve 130 is blocked, whereby no liquid F can flow in during provision at the cleaning connection 310.The delivery quantity MF is thus the liquid F held by the immersion tube 1 16 up to the filling level HF and additionally the liquid F held by the delivery chamber 1 13 up to the filling level HF. Only after the application of compressed air DL, i.e. when there is no longer any delivery pressure PF at the compressed air connection 270, can the inlet check valve 130 open again and cleaning liquid F flow into the delivery volume area 1 10.

[0129] Fig. 8A shows a seventh preferred embodiment of a sensor cleaning device 100, 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 check valve 130. The arrangement and design of the outlet overflow valve 134 and the inlet check valve 130 thus correspond essentially to the arrangement of the third embodiment shown in Fig. 4.

[0130] By means of a spring-loaded inlet overflow valve 138, it is advantageously achieved that compressed air DL provided at the compressed air inlet 270 is only directed into the delivery volume region 110 for the purpose of pressurizing a sensor surface 301 when the delivery pressure PU exceeds a certain minimum value, in particular an inlet overflow pressure PE. Compressed air flows, in particular venting flows with a lower pressure, which would be ineffective, in particular for cleaning, are thus advantageously ineffective for actuating the sensor cleaning device 100.

[0131] Fig. 8B shows an eighth preferred embodiment of a sensor cleaning device 100 which, in contrast to the seventh embodiment shown in Fig. 8A, additionally has a blocking valve seat 278 on the inlet overflow valve 138, and in which a pressure chamber 280 for receiving a compressed air pulse quantity MDI is arranged between the inlet overflow valve valve seat 139C and the blocking valve seat 278.

[0132] If the discharge pressure PF exceeds an inlet overflow pressure PE, an inlet valve body 139B lifts off the inlet valve seat 139C and moves from a closed inlet overflow valve position PUC to an 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 rests on the shut-off valve seat 278 and thus prevents the compressed air DL from flowing into the discharge 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 reopened shut-off valve seat 278 into the delivery volume area 110 to pressurize the delivery quantity MF of the liquid F in a known manner.Advantageously, the pressure chamber 280 and the delivery volume area 110 are dimensioned such that, by means of a resulting compressed air pulse quantity MDI, the liquid in the delivery volume area 110 can be essentially completely displaced, i.e., conveyed to the cleaning connection 310. 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 have a different value, in particular in the range from 2 to 12 bar, preferably from 4 to 8 bar, particularly preferably from 5 to 7 bar.

[0133] Fig. 8C shows, for a ninth preferred and varied embodiment of a sensor cleaning device 100 according to the concept of the invention, a first and second further variant of an inlet overflow valve 138 in combination with the partially adapted pressure chamber 280 and the delivery volume region 110 and otherwise the same design of the eighth preferred embodiment according to Fig. 8B. The ninth preferred and varied embodiment of the sensor cleaning device 100 is varied in particular with regard to the aspects shown in Fig. 8C. In the following, reference is only made specifically to these, it being understood that the description of Fig. 8B applies equally to the remaining parts of the sensor cleaning device 100 of the ninth preferred and varied embodiment. Furthermore, the same reference numerals are used for the same or similar parts or those with the same or similar function merely for the sake of simplicity.

[0134] Fig. 80 again shows a sensor cleaning device 100; this time with a varied inlet overflow valve 138.1 with check valve seat 278 in view (A) of Fig. 80 and the varied inlet overflow valve 138.1 with check valve seat 278 and another inlet overflow valve 138.2 in view (B) of Fig. 80.

[0135] Compared to the embodiment of the sensor cleaning device 100 with the inlet overflow valve 138 according to Fig. 8B, in the inlet overflow valve 138.1 of Fig. 80, an adapted piston 139 of the inlet overflow valve 138.1 is provided in both variants of view (A) and view (B). Referring to the variant of the inlet overflow valve 138.1 shown in the first view (A) of Fig. 80, it can be seen that the adapted piston 139 of the inlet overflow valve 138.1 is geometrically adapted to the check valve seat 278. Namely, in such a way that the first piston surface 139.1 located on the side of the piston 139 facing the compressed air inlet 270 is larger than the second piston surface 139.2 located on the side of the piston 139 facing away from the compressed air inlet 270.

[0136] This adjustment serves to ensure that after pressure equalization—that is, after the pressure chamber 280 has been completely filled with compressed air from the compressed air inlet 270—the piston 139 is held in the open inlet overflow valve position PUO—as shown in Fig. 8C in view (A) and view (B)—due to the pressure forces and area ratios with respect to the first piston surface 139.1 and the second piston surface 139.2. This advantageously prevents, in particular, potential oscillation of the piston 139. Although this is generally rather unlikely, it cannot be completely ruled out due to undefined or unexpectedly fluctuating force ratios as a result of the pressure forces and area ratios, such as in the embodiment of Fig. 8B. The embodiment of the inlet overflow valve 138.1 with check valve seat 278 in Fig. 8C ensures that the piston 139 is held in the open inlet overflow valve position PUO due to the pressure forces and area ratios with respect to the first piston surface 139.1 and second piston surface 139.2 in the open inlet overflow valve position PUO - as shown in Fig. 8C in view (A) and view (B) - - is held even in the case of undefined or unexpectedly fluctuating force ratios on the piston 139.

[0137] In the second variant of the sensor cleaning device 100 shown in view (B) of Fig. 8C, an arrangement of an inlet overflow valve 138 is provided, namely comprising the previously explained inlet overflow valve

[0138] 138.1 with check valve seat 278 according to the first view (A) of Fig. 8C and a further inlet overflow valve 138.2. The further inlet overflow valve

[0139] 138.2 is arranged between the pressure chamber 280 and the delivery volume region 110, in particular here in the delivery volume region 110. This further inlet overflow valve 138.2 prevents the cleaning fluid from flowing into the pressure chamber 280. Fig. 9 schematically shows a preferred embodiment of a pneumatic system 800 with a sensor cleaning device 100 according to the concept of the invention. The pneumatic system 800 has at least one compressed air consumer 820, which is connected to the compressed air inlet 270 of the sensor cleaning device 100 via a compressed air supply line 702 to provide compressed air DL. In particular, the compressed air supply line 702 can be designed as a vent line 703, as shown here, which is connected to a vent connection 3 of the compressed air consumer 820 to provide venting compressed air DLE.Alternatively or additionally, the compressed air inlet 270 can be pneumatically connected to a working connection 2 of the compressed air consumer 820 via a compressed air supply line 702 designed as a working compressed air line 704 to provide a working compressed air supply DLA, as indicated here by dashed lines. Likewise alternatively or additionally, the compressed air inlet 270 can be pneumatically connected to a supply connection 1 of a compressed air source 600, for example a compressed air reservoir 601 and / or a compressor 602, via a compressed air supply line 702 designed as a supply compressed air line 705 to provide a supply compressed air supply DLV, as indicated here by dashed lines.

[0140] The compressed air consumer 820 can, as indicated here by dashed lines, be designed as an air spring system 730 with at least one air spring 732, or as a braking 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 immobilizer 742, or as a container locking system 744, or as a lifting axle 750 with at least one lifting bellows 752. Other compressed air consumers 820 or a combination of the aforementioned compressed air consumers 820, with one another or with further compressed air consumers 820, are also possible.

[0141] The compressed air consumer 820 has a solenoid switching valve 290, which is electrically controllable as a function of an electrical switching signal S1, for the controllable provision of the compressed air DL at the compressed air inlet 270. A liquid reservoir 660 is connected to a liquid inlet 680 of the sensor cleaning device 100 via a liquid supply line 612. In other embodiments, as previously shown, the sensor cleaning device 100 can also be partially or completely arranged within the liquid reservoir 660 and / or integrally connected thereto. At least one cleaning nozzle 320 is fluidly connected to the sensor cleaning device 100 via a cleaning connection 310 in order to receive a compressed air DL and / or a liquid F and / or a spray mixture GS and to direct it onto a sensor surface 301 of a sensor 300 for cleaning.The sensor 300 is preferably designed as an optical sensor 302, particularly preferably as a camera 304 as shown here.

[0142] Preferably, the compressed air can be provided to the cleaning connection 310 upon request from the vehicle driver or the system. This makes it particularly easy to initiate the cleaning process. For example, this can involve an action such as applying the brake to provide compressed air or a systemic release of compressed air.

[0143] Thus, in a preferred embodiment, for example, by (fully) actuating a compressed air consumer, part of its working air can be used as compressed air DL of the cleaning system or the cleaning can be triggered; e.g., by fully actuating the brake, by (briefly) actuating a lifting bellows of a lifting axle, etc.

[0144] Initiating the cleaning process by simply "fully depressing the brakes" is comparatively easy to implement. In particular, it shows that this can be done without any additional communication between the towing vehicle and the trailer (truck / trailer) of the vehicle 1000, allowing the driver to conveniently control it.

[0145] Technically, the brake pressure could theoretically be used directly as compressed air, or the brake pressure from the trailer could be sensed via an electronic braking system (EBS). This could detect the driver's full application of the brakes as a request, trigger a cleaning cycle, and in turn actuate the corresponding compressed air valve connected to compressed air inlet 270.

[0146] LIST OF REFERENCE SYMBOLS (PART OF THE DESCRIPTION)

[0147] 1 supply connection

[0148] 2 working connections

[0149] 3 vent connection

[0150] 100 Sensor cleaning device

[0151] 110 delivery volume range

[0152] 112 Container wall

[0153] 113 Production room

[0154] 114 Front side of the delivery volume area

[0155] 114A first end face of the displacement range

[0156] 114B second end face of the displacement area

[0157] 116 dip tube

[0158] 116A dip tube muzzle

[0159] 117 Immersion tube connection

[0160] 118 conveyor passage

[0161] 119A first page of the conveyor passage

[0162] 119B second side of the conveyor passage

[0163] 130 Inlet check valve

[0164] 131 A Fluid intake valve spring

[0165] 131 B Liquid inlet valve body

[0166] 131 C Fluid inlet valve seat

[0167] 134 Outlet overflow valve

[0168] 135A Exhaust valve spring

[0169] 135B Exhaust valve body

[0170] 135C exhaust valve seat

[0171] 138 Inlet overflow valve

[0172] 138.1 , 138.2 Variant inlet overflow valve, additional inlet overflow valve

[0173] 139 Piston of the varied inlet overflow valve

[0174] 139.1 on the side facing the compressed air inlet 270, the first piston surface

[0175] 139.2 second piston surface located on the side facing away from the compressed air inlet 270 A inlet valve spring B inlet valve body C inlet valve seat

[0176] Compressed air inlet

[0177] Compressed air branch

[0178] Locking valve seat

[0179] pressure chamber

[0180] Solenoid switching valve

[0181] Level sensor

[0182] sensor

[0183] Sensor surface optical sensor

[0184] camera

[0185] Cleaning connection

[0186] Cleaning nozzle

[0187] Compressed air source

[0188] Compressed air storage tank

[0189] compressor

[0190] nozzle line

[0191] Liquid supply line

[0192] Liquid storage tank

[0193] Tank wall lower area of ​​the liquid storage tank upper area of ​​the liquid storage tank liquid inlet electronic control unit

[0194] Compressed air supply line

[0195] vent line

[0196] Working compressed air line

[0197] Supply compressed air line electrical line

[0198] braking system

[0199] Parking brake system 712 Service brake system 722 Parking brake cylinder 728 Service brake cylinder 730 Air suspension system 732 Air springs 734 Air suspension valve 740 Steering axle lock

[0200] 742 Immobilizer 744 Container locking system 750 Lift axle

[0201] 752 Bellows 800 Pneumatic system 820 Compressed air consumer 1000 Vehicle 1006 Trailer 1007 Rear area

[0202] A Longitudinal axis AF Conveying distance AL Longitudinal axis AQ Cross-sectional area BR Direction of application DL Compressed air DLA Working compressed air

[0203] DLD Throttle air flow DLE Vent compressed air DLV Supply compressed air F Liquid FE Inlet spring force FEF Liquid inlet spring force FR Flow direction

[0204] FS Outlet spring force G Gravity GS Spray mixture

[0205] HF filling level

[0206] HFM maximum filling height

[0207] HFZ delivery head

[0208] HT tank height

[0209] MDI compressed air pulse quantity

[0210] MF flow rate

[0211] PE inlet overflow pressure

[0212] PF discharge pressure

[0213] PU outlet overflow pressure

[0214] PUC intake overflow valve position

[0215] PUO Inlet overflow valve position

[0216] 51 electrical switching signal, electronic switching signal

[0217] 52 electrical level signal, electronic level signal

[0218] U environment

Claims

Patent claims 1. Sensor cleaning device (100) for a vehicle (1000), designed to clean at least one sensor surface (301) of a sensor (300), wherein the sensor cleaning device (100) comprises: a compressed air inlet (270) designed to receive compressed air (DL), a liquid inlet (680) designed to receive liquid (F), a cleaning connection (310) designed to provide the liquid (F) and / or the compressed air (DL), characterized by a delivery volume region (110) designed to receive the liquid (F), which is fluid-conductingly connected to the compressed air inlet (270), the liquid inlet (680) and the cleaning connection (310), such that the liquid (F) is delivered to the cleaning connection (310) by applying the compressed air (DL) to the compressed air inlet (270) in a delivery direction (FR), wherein the delivery volume region (110) is designed such thatthat the compressed air (DL) for conveying the liquid (F) is in a pressure-transmitting contact with the liquid (F), in particular direct and / or forming a phase boundary.

2. Sensor cleaning device (100) according to claim 1, characterized in that the delivery volume area (110) is designed to receive a delivery quantity (ML) of the liquid (F), wherein the delivery quantity (MF) is conveyed by applying the compressed air (DL) to the compressed air inlet (270) in a conveying direction (FR) to the cleaning connection (310).

3. Sensor cleaning device (100) according to claim 1 or 2, characterized by a pneumatic separating means, in particular an inlet check valve (130), arranged at the liquid inlet (680) of the conveying volume region (110), which opens in a conveying direction (FR) and closes against the conveying direction (FR).

4. Sensor cleaning device (100) according to one of claims 1 to 3, characterized by an outlet overflow valve (134) arranged at the cleaning connection (310) of the delivery volume area (110), which opens in a delivery direction (FR), preferably against an outlet spring force (FS) of a valve spring (135A), and closes against the delivery direction (FR).

5. Sensor cleaning device (100) according to one of the preceding claims, characterized by an inlet overflow valve (138) arranged at the compressed air inlet (270) of the delivery volume area (110), opening in the direction of a direction of application (BR) of the compressed air (DL) and blocking against the direction of application (BR), which is preferably spring-loaded.

6. Sensor cleaning device (100) according to one of the preceding claims, characterized in that the compressed air inlet (270) has a shut-off valve seat (278) which can be closed by an inlet overflow valve (138) depending on an 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), which pressure chamber is designed to receive a compressed air pulse quantity (MDI) from the compressed air inlet (270), when the inlet overflow valve (138) is in an open inlet overflow valve position (PUO), and to provide the compressed air pulse quantity (MDI) via the blocking valve seat (278) to the displacement volume area (110) when the overflow valve (138) is in a closed overflow valve position (PUC).

7. Sensor cleaning device (100) according to one of claims 1 to 6, characterized in that - the delivery volume area (110) is pneumatically decoupled from a storage area, in particular from a liquid storage tank (660), by a pneumatic separating means at the liquid inlet (680), in particular an inlet check 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. Sensor cleaning device (100) according to one of the preceding claims, characterized in that the delivery volume region (110) is formed distally from the storage region, downstream of the pneumatic separating means at the liquid inlet (680).

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

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

11. Sensor cleaning device (100) according to 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 on or in the delivery volume area (110).

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

13. Sensor cleaning device (100) according to one of the preceding claims, characterized in that the outlet overflow valve (134) is spaced apart from the inlet check valve (130) in the direction of a gravitational force (G) at a delivery head (HFZ), and / or a magnetic switching valve (290) arranged at the compressed air inlet (270), designed for the controllable actuation of the compressed air inlet (270).

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

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

16. Pneumatic system (800) according to claim 15, characterized by a compressed air consumer (820), wherein preferably a vent connection (3) of the compressed air consumer (820) is connected or connectable to the compressed air inlet (270) for receiving a venting compressed air (DLE) as compressed air (DL) or preferably a working connection (2) of the compressed air consumer (820) is connected or connectable to the compressed air inlet (270) for receiving a working compressed air (DLA) as compressed air (DL).

17. Vehicle (1000), preferably a commercial vehicle (1002) or passenger car (1004) or trailer (1006), comprising a sensor cleaning device (100) according to 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 one of claims 1 to 14, comprising the steps of: automatically filling a delivery volume area (110) with a liquid (F) from a liquid storage tank (660), preferably via an inlet check valve (130), Applying compressed air (DL) to the liquid (F) which is in pressure-transmitting contact with the liquid (F), in particular direct and / or forming a phase boundary, Providing the pressurized liquid (F) at a cleaning connection (310), in particular also providing the compressed air (DL) at the cleaning connection (310), preferably subsequently or simultaneously providing the compressed air (DL) at a cleaning connection (310).

19. Method according to claim 18, characterized by the steps: Directing the liquid (F), preferably the flow rate (MF), and / or the compressed air (DL) onto a sensor surface (301) of a sensor (300), Determining a waiting time (TW) that elapses between the activation of a solenoid valve (290) for the controlled application of compressed air (DL) to the liquid (F) and the liquid (F) striking the sensor surface (301), and / or Determining an exposure period (TB) in which the sensor surface (301) is exposed to the liquid (F) by means of the sensor (300), and Determining a filling level (HF) of the liquid (F) in the liquid storage tank (660) and / or in the delivery volume range (1 10) as a function of the waiting time (TW) and / or the loading period (TB).

20. Method according to claim 18 or 19, characterized by the step: controlling a compressed air consumer (820), preferably actuating the Compressed air consumer (820) for providing a working compressed air (DLA) to the sensor cleaning device (100), preferably at a compressed air inlet (270) of the sensor cleaning device (100), for pressurizing the liquid (F).

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