Method for cleaning a surface of a motor vehicle

Abstract

The invention relates to a method for cleaning a surface of a motor vehicle, using a cleaning device comprising: a reservoir of cleaning liquid; at least one nozzle (2) for spraying the cleaning liquid; a fluid dispersion circuit designed to transport the cleaning liquid from the reservoir to the cleaning nozzle (2); and a pump designed to inject the cleaning liquid contained in the reservoir into the fluid dispersion circuit, the fluid dispersion circuit comprising a dispersion block (6) of cleaning liquid comprising a number of valves (8) having substantially the same flow rate, the nozzle (2) being connected to a number of valves (8) of the dispersion block (6), the method being characterized in that it comprises the following steps: commanding the operation of the pump to inject the cleaning liquid contained in the reservoir into the dispersion block (6), commanding the opening of a number of valves (8) connected to the nozzle (2) when the pressure at the inlet of the dispersion block (6) reaches a predetermined pressure, as a function of the desired pressure at the outlet of the nozzle (2), and spraying the cleaning liquid from the nozzle (2) onto the surface to be cleaned.

Description

Technical Field

[0001] The present invention relates to an apparatus for cleaning the surface of a motor vehicle and intends to mount the apparatus on a motor vehicle. Background Technology

[0002] Many surfaces, such as sensors on motor vehicles, can be subjected to a variety of types of dirt. These include, for example, various driver assistance cameras or distance sensors placed on vehicles, ultrasonic sensors, radar, lidar sensors, or rain sensors.

[0003] Currently, dirt can cause malfunctions in certain devices or make the vehicle user experience difficult (due to the lack of visibility on the windshield). Therefore, it is necessary to provide a device for cleaning these surfaces.

[0004] Conventionally, such a cleaning device consists of a reservoir and a fluid distribution line. The cleaning liquid is stored in the reservoir, and the fluid distribution line consists of multiple pipes or tubes that allow the cleaning liquid to be delivered to at least one cleaning nozzle, which is placed in front of a surface to spray the cleaning liquid onto the surface (as is generally the case, there are multiple cleaning nozzles for multiple surfaces).

[0005] The pump is designed to push cleaning liquid in the fluid dispersion line to a cleaning nozzle, which is typically mounted directly on the reservoir. More specifically, the pump's inlet line is forced into an opening manufactured in the reservoir (a seal is used to ensure the assembly is leak-proof), and in this part, the drain port is connected to the fluid dispersion line.

[0006] When the sensor detects a malfunction due to the presence of dirt (e.g., automatically detected), or when the user activates the cleaning device, the pump draws cleaning fluid from the reservoir at the same pressure as standard atmospheric pressure (the pressure depends on the top of the cleaning fluid in the reservoir), and pushes the fluid into a fluid dispersion line at a higher pressure (the pressure difference depends on the pump's capacity). The pressurized cleaning fluid is then sprayed onto the sensor through a cleaning nozzle.

[0007] However, this device may have drawbacks in terms of cleaning performance.

[0008] Specifically, a pressure drop was found that depends on the distance between the pump and the cleaning nozzle. This distance varies depending on the location of the cleaning nozzle on the vehicle. Therefore, surface cleaning may be ineffective because the pressure of the cleaning fluid leaving the cleaning nozzle is too low.

[0009] Pumps could be added, for example, in as many as the nozzles (or even reservoirs for the cleaning liquid), and placed quite close to the cleaning nozzles. However, this decision results in an architecture that is complex and has high manufacturing and maintenance costs.

[0010] A significant objective of this invention is to provide a method for cleaning the surface of motor vehicles that overcomes the following problems, both in terms of minimizing pressure drop and in terms of being achievable with a cleaning device of a simple architecture. Summary of the Invention

[0011] Therefore, the present invention relates to

[0012] A method for cleaning the surface of a motor vehicle, the method using a cleaning apparatus comprising: a reservoir of a cleaning liquid; at least one nozzle for spraying the cleaning liquid; a fluid dispersion line designed to deliver the cleaning liquid from the reservoir to the cleaning nozzle; and a pump designed to inject the cleaning liquid contained in the reservoir into the fluid dispersion line, the fluid dispersion line comprising a dispersion block of the cleaning liquid, the dispersion block comprising a plurality of valves having substantially the same flow rate, the nozzle being connected to the plurality of valves of the dispersion block, the method characterized by comprising the following steps:

[0013] The pump is instructed to operate to inject the cleaning liquid contained in the reservoir into the dispersion block.

[0014] When the pressure at the inlet of the dispersion block reaches a predetermined pressure, based on the desired pressure at the outlet of the nozzle, several valves connected to the nozzle are instructed to open, and

[0015] The cleaning liquid is sprayed from the nozzle onto the surface to be cleaned.

[0016] This leads to another approach where pressure drop is limited or even eliminated. First, the presence of a valve in the fluid dispersion line creates an intermediate stage-level that allows activation to occur in both phases, with the pump activated in the first phase and the valve subsequently opening when the pressure at the dispersion block inlet is satisfied. This then reduces the length of the unobstructed path through which the cleaning fluid flows, and thus has a significant pressure drop, creating a compression stage.

[0017] Furthermore, by dividing the liquid flow for the nozzle among several valves, the total flow velocity entering the dispersion block is divided by the number of valves connected to the nozzle. The pressure drop of each valve is significantly lower than that when using a single valve. Therefore, some valves connected to the nozzle (several valves) or all valves connected to the nozzle can be opened to limit the pressure drop involved through the dispersion block. By employing this method, the pressure drop is further limited. The pressure obtained at the nozzle outlet can even be selected by choosing the number of valves to be opened connected to the nozzle.

[0018] When using standard components, this can affect the pressure drop, and more generally, the pressure at the cleaning nozzle.

[0019] Depending on the further optional features of the cleaning system, the following items may be selected individually or in combination:

[0020] The number of valves that can be opened depends on the distance between the nozzle and the dispersion block, with each nozzle connected to several valves. Therefore, the farther a cleaning nozzle is from the dispersion block, the more valves can be opened to ensure the pressure drop is as low as possible.

[0021] The number of valves opened depends on the ambient temperature. In low-temperature conditions, the greater pressure drop can be compensated by opening more valves connected to the cleaning nozzle.

[0022] All valves open upon command to open the valve connected to the nozzle. This minimizes pressure drop as much as possible.

[0023] The cleaning method further includes the following steps:

[0024] Activate the pump with the valve closed, and

[0025] Open the valve.

[0026] This creates a compression stage level in the section of the fluid dispersion circuit located between the pump and the dispersion block. This limits the pressure drop;

[0027] The cleaning device includes a control unit connected to the distribution block and configured to command the opening and closing of the valve assembly.

[0028] The control unit commands a certain number of valves to open, the number of valves varying depending on the desired pressure at the cleaning nozzle outlet;

[0029] The cleaning device includes a plurality of nozzles, each nozzle being connected to a set of valves, and the method includes, after instructing the operation of a pump to inject cleaning liquid contained in a reservoir into a dispersion block, instructing the opening of a plurality of valves in each set of valves.

[0030] The valve is configured to have a range of 0.12 to 0.15 m. 3 The export metric flow rate is between / h.

[0031] The valve is a solenoid valve. Attached Figure Description

[0032] The invention will be better understood by reading the following description, which is provided purely by way of example and reference to the accompanying drawings, wherein:

[0033] Figure 1 This is a schematic illustration of a part of the cleaning device according to the present invention, and

[0034] Figure 2It is a graphical representation that shows the pressure drop of liquid as it passes through one or more valves as a function of the flow rate entering one or more valves.

[0035] The embodiments described with reference to the figures in the example are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features described are applicable only to a single embodiment. Individual features of various embodiments can also be combined to create other embodiments.

[0036] The terms "upstream" and "downstream" are used to position an element / device in the direction of transport of the material stream to be processed. If the material is first processed by a first device and then by a second device, the first device / element, such as a pump, is therefore located upstream of the second device / element. Detailed Implementation

[0037] For reference Figure 1 This image shows a portion of the cleaning apparatus according to the invention. The goal of this cleaning system is to be able to clean various surfaces of a motor vehicle, such as sensors mounted on the vehicle, or the windshield or rear window.

[0038] This cleaning device includes a reservoir (not shown) for a cleaning liquid, on which a pump (not shown) is mounted. The pump is mounted in a recess within the reservoir for accommodating the pump. The reservoir includes an orifice through which the pump's inlet pipe is installed. A seal surrounding the orifice is present at the interface between the reservoir and the pump to ensure leak-proof assembly. As is conventional, the pump is a standard pump, including, for example, a tubular body. This body may consist of a pump-driven first part and a drive second part, including an electric motor. The pump-driven first part includes an inlet pipe and an outlet pipe, allowing it to receive the cleaning liquid from the reservoir and discharge it at a pressure higher than the pump's inlet pressure. The inlet pipe may be positioned at the free end of the pump-driven first part and may be coaxial with the pump body, sharing a common axis of rotation. The outlet second part extends from the pump-driven first part in a direction perpendicular to the axis of rotation of the body.

[0039] The drive section can be located above the pump drive section and includes an electric motor and a connector at its free end that enables the pump to be connected to a power source.

[0040] Multiple cleaning nozzles 2 and 4 may be installed and placed at the other end of the cleaning device and intended to be positioned in front of the surface of the motor vehicle to be cleaned, so as to spray pressurized cleaning liquid onto it.

[0041] The cleaning device also includes pipes (or conduits) that connect different components (pumps, cleaning nozzles 2 and 4, etc.) to form a fluid dispersion line.

[0042] The cleaning device also includes a dispersing block 6 for the cleaning liquid, which includes several valves 8 (four are depicted in this example). The pump is configured to pump the cleaning liquid from the reservoir and deliver it to the dispersing block 6 and the cleaning nozzles 2 and 4.

[0043] The valves 8 of the dispersion block 6 are configured to be fluidly connected to the nozzles respectively. At least one nozzle, in this example nozzle 2, is connected to several valves. Figure 1 There are three valves in the middle. The number of nozzles connected to several valves can naturally vary, just as the number of valves connected to a single nozzle can vary.

[0044] Valve 8 is configured to selectively deliver pumped cleaning fluid to the associated cleaning nozzle. Valve 8 is, for example, a solenoid valve conventionally used in this type of cleaning device. Valves 8 can be arranged in parallel, meaning they are all connected to a fluid conduit of the dispersing block 6. The fluid conduit is connected to the inlet of the dispersing block 6, which is connected to the pump. The outlet of the dispersing block 6 can be covered by a cap. Alternatively, a return line to a reservoir can be provided at the outlet of the dispersing block 6, returning the liquid to the reservoir and having an overpressure valve.

[0045] Valve 8 has a substantially identical flow rate. This again demonstrates the expectation of standardization achieved by using valves with the same or very similar specifications. For example, valve 8 has a flow rate that differs from each other by a maximum of 5%. For example, valve 8 is configured to have a flow rate between 0.12 and 0.15 m. 3 The nominal export metric flow rate between / h.

[0046] Therefore, during operation, activating the pump can deliver the cleaning liquid from the reservoir toward the dispersing block 6 and toward the cleaning nozzle, with one or more associated valves 8 open.

[0047] The dispersing block 6 is a modular block, so the number of valves 8 can be easily modified to accommodate the number of cleaning nozzles or a specific configuration of the cleaning device, such as depending on the model of the vehicle if the cleaning device is installed on a motor vehicle. Different dispersing blocks 6 can also be combined.

[0048] As for the method of cleaning the surface using nozzle 4, it involves activating the pump and opening valve 8 to spray cleaning liquid through cleaning nozzle 4.

[0049] As for the cleaning method using nozzle 2, the first step is also to instruct the pump to inject the cleaning liquid contained in the reservoir into the dispersing block 6. The valve 8 connecting the pump to nozzle 2 can be closed to pressurize the section of the fluid dispersion line between the pump and the dispersing block 6 until maximum pressure is reached (the same applies to nozzle 4). This creates a compression step level in the upstream section of the dispersing block 6 and thus limits the pressure drop in the fluid dispersion line.

[0050] The second step involves instructing several valves connected to the nozzle to open when the pressure at the inlet of the dispersion block reaches a predetermined pressure (maximum or intermediate, as explained above), based on the desired pressure at the nozzle outlet. The number of valves 8 that are opened can vary depending on certain parameters, as shown later.

[0051] The passage of liquid through valve 8 can be as follows Figure 2 The minimized pressure drop is shown, displaying the pressure drop (vertical axis) as a function of the flow velocity at the inlet of valve 8 (horizontal axis). Specifically, for valves used in this type of application in a typical manner, when only a single valve is in use, the liquid flow velocity at the valve inlet is approximately 30 mL / s. The pressure drop is approximately 0.9 bar, as can be seen from... Figure 2 Point 12 on the middle curve.

[0052] In contrast, for example, when three valves are opened under the same conditions to allow the same amount of liquid to pass through, the liquid is divided among the three valves, and the flow rate at the inlet of each valve is divided into three parts, becoming 10 mL / s. The pressure drop is then approximately 0.1 bar, as can be seen in... Figure 2 Point 10 on the curve. This allows for a significant reduction in the pressure drop across the dispersion block 6.

[0053] Adjusting the number of valves connected to the nozzle and the number of valves opened can regulate the pressure at the outlet of the dispersion block and thus the pressure at the nozzle outlet, for example, to achieve the highest possible pressure at the nozzle outlet. It is conceivable that by changing the number of valves 8 open, there are several cleaning modes for cleaning surfaces, for example, depending on the degree of surface dirtiness. Therefore, by opening more or fewer valves 8 connected to nozzle 2, the pressure at the outlet of nozzle 2 will differ, and these correspond to different cleaning modes.

[0054] The cleaning liquid can thus reach nozzle 2 and be sprayed onto the surface to be cleaned.

[0055] Preferably, the number of open valves 8 depends on the distance between the nozzle 2 connected to the valve and the dispersion block 6. Specifically, and to avoid pressure drop affecting the nozzles (e.g., nozzles 2 far from the dispersion block 6), a large number of valves 8 can be provided to the nozzles and all valves can be opened to maximize the limitation of pressure drop along the fluid dispersion path, such as by dividing the cleaning liquid between the valves 8 as explained above. Thus, there can be several nozzles at different distances from the dispersion block 6, each nozzle connected to a different number of valves 8 according to its distance. For example, nozzle 4 connected to a single valve 8 is closer to the dispersion block 6 than nozzle 2 connected to three valves 8, and thus has a greater potential pressure drop for nozzle 4.

[0056] The number of valves 8 that are open can also depend on the ambient temperature. Specifically, lower temperatures lead to a higher pressure drop. Therefore, when the temperature is lower, more valves can be opened to ensure that the pressure drop is minimized sufficiently.

[0057] All valves 8 can be opened upon command to open the valves 8 connected to nozzle 2. This results in maximum pressure at the outlet of nozzle 2. As mentioned above, only some valves 8 connected to nozzle 2 may be opened, for reasons such as those stated above.

[0058] The cleaning device may include a control unit connected to the distribution block 6 and configured to command the opening and closing of the valve assembly 8. This allows for centralized command and enables the various opening valve movements described above to be set in place.

[0059] The control unit can command a certain number of valves 8 to open, the number of valves 8 depending on the desired pressure change at the cleaning nozzle outlet. Specific examples of various possibilities for opening the valves 8 of the dispersion block 6 are given here.

[0060] As described above, the cleaning device may include a plurality of nozzles, each nozzle being connected to a set of valves 8. The method includes, after instructing the pump to inject cleaning liquid contained in a reservoir into the distributing block 6, instructing to open a plurality of valves 8 in each set of valves. In particular, the number of valves 8 connected to the nozzles may vary depending on the parameters verified above (distance between the nozzle and the distributing block 6, the ability to achieve several different cleaning modes, etc.).

[0061] Reference List

[0062] 2, 4: Cleaning nozzles

[0063] 6: Cleaning liquid dispersion blocks

[0064] 8: Valve

[0065] 10: Points showing the pressure drop at an inlet flow rate of 10 mL / min.

[0066] 12: Points showing the pressure drop at an inlet flow rate of 30 mL / min.

Claims

1. A cleaning method for cleaning the surface of a motor vehicle, the cleaning method using a cleaning apparatus comprising: A container for cleaning liquids; At least one nozzle for spraying cleaning liquid (2); fluid The dispersion line is designed to deliver cleaning liquid from the reservoir to the nozzle (2); The cleaning method is characterized by including the following steps: A pump designed to inject a cleaning liquid contained in a reservoir into a fluid dispersion line comprising a dispersion block (6) of the cleaning liquid, the dispersion block comprising a plurality of valves (8) having substantially the same flow rate, the nozzle (2) being connected to the plurality of valves (8) of the dispersion block (6). The pump is instructed to operate to inject the cleaning liquid contained in the reservoir into the dispersion block (6). When the pressure at the inlet of the dispersion block (6) reaches a predetermined pressure, based on the desired pressure at the outlet of the nozzle (2), a number of valves (8) connected to the nozzle (2) are instructed to open, wherein the number of valves (8) opened depends on the distance between the nozzle (2) and the dispersion block (6), and the nozzle (2) is connected to the number of valves (8). The cleaning liquid is sprayed from the nozzle (2) onto the surface to be cleaned.

2. The cleaning method according to claim 1, wherein, The number of valves (8) that are open depends on the ambient temperature.

3. The cleaning method according to claim 1 or 2, wherein, All valves (8) are opened according to the command to open the valve (8) connected to the nozzle (2).

4. The cleaning method according to claim 1 or 2 further includes the following step: Activate the pump with the valve (8) closed, and Open the valve (8).

5. The cleaning method according to claim 1 or 2, wherein the cleaning device includes a control unit connected to the dispersion block (6) and configured to command the opening and closing of a set of valves.

6. The cleaning method according to claim 5, wherein, The control unit commands to open a certain number of valves (8), the number of which varies depending on the desired pressure at the outlet of the nozzle (2).

7. The cleaning method according to claim 1 or 2, wherein the cleaning device comprises a plurality of nozzles, wherein each nozzle is connected to a set of valves, the cleaning method comprising, after instructing the pump to operate to inject cleaning liquid contained in a reservoir into the dispersion block (6), instructing to open a plurality of valves (8) of each set of valves.

8. The cleaning method according to claim 1 or 2, wherein the valve (8) is configured to have a range of 0.12 to 0.15 m 3 The export metric flow rate is between / h.

9. The cleaning method according to claim 1 or 2, wherein the valve (8) is a solenoid valve.

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