Method for controlling a telescopic hydraulic nozzle for a motor vehicle

Abstract

The invention relates to a control method (1) for controlling a telescopic hydraulic nozzle (2) of a device for cleaning a surface to be cleaned on a motor vehicle, the control method (1) comprising a step of regulating (11) the pressure of a cleaning liquid flowing through a supply pipe (21) of the telescopic hydraulic nozzle (2) so as to control the extension or retraction of the telescopic hydraulic nozzle (2). The regulating step (11) comprises a plurality of cycles comprising a step (12) of increasing the pressure beyond a threshold value and a step (13) of decreasing the pressure below the threshold value, in order to control a retraction distance (Y) of the telescopic hydraulic nozzle (2) through multiple partial back-and-forth movements over the surface to be cleaned.

Description

Method for controlling a telescopic hydraulic nozzle for a motor vehicle

[0001] The technical context of the present invention is that of systems for cleaning detection devices of a motor vehicle. More particularly, the invention relates to a method for controlling a telescopic hydraulic nozzle for a motor vehicle, and a telescopic hydraulic nozzle controlled by such a control method.

[0002] In the state of the art, the use of numerous detection devices deployed on motor vehicles is known, making it possible to detect a near or distant environment around the motor vehicle. Such detection devices are used, for example, to help or assist the driver during maneuvers, for example, to park his motor vehicle, or to detect the presence of another vehicle located in a blind spot when overtaking, to detect a crossing of lines on the road or to detect motor vehicles or pedestrians located near the motor vehicle. By way of non-limiting examples, such detection devices include, for example, cameras, radars, LIDARs (an acronym for "light detection and ranging" meaning laser remote sensing) or ultrasonic sensors or infrared wave sensors.Such detection devices generally comprise a detection surface through which waves emitted by the detection device are emitted towards the external environment of the motor vehicle on which these detection devices are installed.

[0003] In order not to disturb the waves emitted by these detection devices and to guarantee optimal operation, it is sought to keep their detection surface clean. To this end, it is known to associate with these detection devices, devices for cleaning the detection surface of said detection devices.

[0004] Cleaning devices are known which allow a cleaning liquid to be projected against the detection surface. In particular, cleaning devices are known which have projection nozzles which are fixed and which do not move or move during the pressurization and during the projection of the cleaning liquid onto the detection surface. Such fixed projection nozzles are particularly suitable for small detection surfaces. Also, such cleaning devices having fixed projection nozzles are generally associated with small sensors.

[0005] On the other hand, telescopic projection nozzles are also known which allow movement relative to the detection surface, by retraction. Such telescopic projection nozzles are particularly suitable for larger detection surfaces. In addition, such telescopic projection nozzles have better cleaning performance, because their retraction makes it possible to better compensate for the aerodynamic effect generated by the movement of the motor vehicle on the cleaning liquid projected onto the detection surface when the motor vehicle is moving, or to better manage the viscosity of the cleaning liquid projected when it is used in cold weather.

[0006] Among the telescopic projection nozzles, we know the telescopic hydraulic nozzles whose retraction is simply triggered by the hydrodynamic pressure of the cleaning liquid flowing in the telescopic hydraulic nozzle: beyond a threshold pressure, the hydrodynamic pressure present inside the telescopic hydraulic nozzle generates a sufficient force to allow the retraction of part of the head of the telescopic hydraulic nozzle. Conversely, below the threshold pressure, the hydrodynamic pressure of the cleaning liquid flowing in the telescopic hydraulic nozzle is no longer sufficient, and the force of a return spring allows the head of the telescopic hydraulic nozzle to be retracted.

[0007] Thus, the known hydrodynamic nozzles are used in a binary manner: either the hydrodynamic pressure flowing in the telescopic hydraulic nozzle is higher than the threshold pressure and the head of the telescopic hydraulic nozzle is then retracted to allow the cleaning liquid to be projected, or the hydrodynamic pressure of the cleaning liquid flowing in the telescopic hydraulic nozzle is insufficient and, in this case, the telescopic hydraulic nozzle is retracted so that the cleaning liquid is no longer projected.

[0008] However, it is observed that in certain particularly difficult usage situations, such as for example in the presence of dirt that is particularly difficult to remove – such as the presence of crushed mosquito(s) on the detection surface, or when the outside temperature is very cold, for example below -10°C, or when the cleaning liquid is particularly viscous and leads to degraded cleaning. In addition, although the cleaning act could be more effective with an increase in liquid pressure, such an increase in pressure has its own disadvantages in a telescopic nozzle system.More specifically, since the deployment of the telescopic nozzle head is at least partly a function of the cleaning liquid pressure, an increase in pressure subsequently leads to an increase in the deployment speed, and consequently a reduction in cleaning efficiency due to the too short passage time on the surface to be cleaned. Thus, known telescopic hydraulic nozzles do not always provide satisfaction.

[0009] The object of the present invention is to propose a new method for controlling such telescopic hydraulic nozzles in order to at least largely address the above problems and to further lead to other advantages.

[0010] Another aim of the invention is to improve the cleaning of a detection surface under all circumstances.

[0011] According to a first aspect of the invention, at least one of the aforementioned objectives is achieved with a method for controlling a telescopic hydraulic nozzle of a device for cleaning a surface to be cleaned on a motor vehicle, the control method comprising a step of regulating a flow rate and / or a pressure of cleaning liquid circulating in a supply conduit of the telescopic hydraulic nozzle so as to control the extension or folding of the telescopic hydraulic nozzle.

[0012] In the context of the present invention, the telescopic hydraulic nozzle comprises a retractable conduit slidably mounted in a static conduit, the retractable conduit being able to extend out of the static conduit under the effect of a hydraulic pressure exerted by the cleaning liquid circulating in the telescopic hydraulic nozzle when said pressure is greater than a pressure threshold value, and an elastic return element configured to generate a non-zero force on the retractable conduit so as to allow the retractable conduit to fold into the static conduit when the hydraulic pressure exerted by the cleaning liquid circulating in the telescopic hydraulic nozzle is less than the pressure threshold value. Thus, such a telescopic hydraulic nozzle allows it to be retracted or withdrawn under the simple effect of the hydrodynamic pressure of the cleaning liquid flowing in the telescopic hydraulic nozzle.

[0013] In the context of the present invention, the control method is ultimately a method for regulating the pressure and / or flow rate of the cleaning liquid circulating in the telescopic hydraulic nozzle in order to, concomitantly with the projection of the cleaning liquid out of the telescopic hydraulic nozzle, control the retraction or withdrawal of the retractable conduit relative to the static conduit of the telescopic hydraulic nozzle. For this purpose, the regulation step makes it possible to control the hydraulic pressure in the telescopic hydraulic nozzle. The regulation of the flow rate and / or pressure of the cleaning liquid in the telescopic hydraulic nozzle is carried out by any known regulation means, such as for example via a solenoid valve or a pump.

[0014] Thus, the control method according to the first aspect of the invention solves the technical problem in that it allows better control of the relative position of the telescopic hydraulic nozzle with respect to the detection surface to be cleaned. Indeed, by controlling the flow rate and / or pressure of cleaning liquid flowing into the telescopic hydraulic nozzle, it is possible to control the position of the jet of cleaning liquid on the surface to be cleaned, thus making it possible to improve its cleaning in a more precise manner than was previously achieved with such telescopic hydraulic nozzles.

[0015] The control method in accordance with the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements being able to be taken alone or in combination:

[0016] - a pressure of the cleaning liquid flowing into the telescopic hydraulic nozzle is greater than 2.5 bar or even greater than 4 bar, preferably greater than 6 bar. These hydraulic pressure levels in the telescopic hydraulic nozzle are higher than the pressures at which telescopic hydraulic nozzles are generally used – typically around 2 bar only. This advantageous configuration provides a hydrodynamic “reserve” allowing more precise control of the movement – ​​retraction or withdrawal – of the telescopic hydraulic nozzle;

[0017] - the regulation step comprises a step of increasing the flow rate and / or the pressure of the cleaning liquid beyond a pressure threshold value in order to retract the telescopic hydraulic nozzle. The pressure threshold value thus determines a turning point of the telescopic hydraulic nozzle: if the hydraulic pressure is greater than the pressure threshold value, then the retractable conduit of the telescopic hydraulic nozzle retracts out of the static conduit of said telescopic hydraulic nozzle. On the other hand, if the hydraulic pressure is lower than the pressure threshold value, then the retractable conduit of the telescopic hydraulic nozzle retracts into the static conduit of said telescopic hydraulic nozzle. However, advantageously, in both situations, the cleaning liquid continues to be sprayed by the telescopic hydraulic nozzle;

[0018] - the regulation step includes a step of reducing the flow rate and / or the pressure of the cleaning liquid below the pressure threshold value in order to fold the telescopic hydraulic nozzle;

[0019] - the pressure threshold value is equal to 1.5 bar, preferably greater than 4.5 bar;

[0020] - the regulation step comprises at least one iteration of the following steps: (i) a step of increasing the flow rate and / or the pressure beyond the pressure threshold value for a first duration, (ii) a step of decreasing the flow rate and / or the pressure below the pressure threshold value for a second duration;

[0021] - the second duration is equal to or different from the first duration. Generally, the first duration is between 0.1 and 10 times the second duration. These advantageous configurations make it possible to specifically define retraction ramps and withdrawal ramps of the retractable conduit of the telescopic hydraulic nozzle;

[0022] - according to a first advantageous embodiment, the first duration is equal to twice the second duration. According to a second advantageous embodiment, the first duration is equal to five times the second duration.

[0023] According to a second aspect of the invention, there is provided a telescopic hydraulic nozzle for cleaning a surface to be cleaned of a sensor of a motor vehicle, the telescopic hydraulic nozzle being controlled by the control method according to the first aspect of the invention or according to any of its improvements, the telescopic hydraulic nozzle comprising:

[0024] - a retractable conduit mounted to slide in a static conduit, the retractable conduit being able to extend out of the static conduit under the effect of hydraulic pressure exerted by the cleaning liquid circulating in the telescopic hydraulic nozzle greater than a pressure threshold value;

[0025] - an elastic return element configured to generate a non-zero force on the retractable conduit so as to allow the retractable conduit to fold into the static conduit if the hydraulic pressure exerted by the cleaning liquid circulating in the telescopic hydraulic nozzle is lower than the pressure threshold value.

[0026] According to a third aspect of the invention, there is provided a device for cleaning a surface to be cleaned of a sensor of a motor vehicle, the cleaning device comprising:

[0027] - the telescopic hydraulic nozzle according to the second aspect of the invention;

[0028] - a supply pipe connecting the telescopic hydraulic nozzle to a cleaning liquid tank;

[0029] - a pump configured to generate and control a flow rate and / or pressure of the cleaning liquid in the supply conduit and to the telescopic hydraulic nozzle.

[0030] If the cleaning device only comprises the pump for controlling the hydraulic pressure of the cleaning liquid in the telescopic hydraulic nozzle, for example by controlling its flow rate, then it is the pump which is controlled by the control method according to the first aspect of the invention. This configuration is particularly advantageous for binary control of the pump, simpler to implement and more economical.

[0031] Optionally, the cleaning device comprises a solenoid valve located in an intermediate position between the pump and the telescopic hydraulic nozzle, the control method according to the first aspect of the invention being applied to the control of the solenoid valve in order to more precisely control the flow rate and / or the pressure of cleaning liquid in the telescopic hydraulic nozzle. This advantageous configuration makes it possible to more precisely control the hydraulic pressure of cleaning liquid in the telescopic hydraulic nozzle, thus making it possible to more precisely control the retraction and withdrawal of the telescopic hydraulic nozzle relative to the surface to be cleaned.

[0032] Various embodiments of the invention are provided, incorporating, in all their possible combinations, the various optional features set out herein.

[0033] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0034] illustrates a synoptic view of the control method according to the first aspect of the invention;

[0035] illustrates a view of an exemplary embodiment of a telescopic hydraulic nozzle controlled by the control method and in three different operating states;

[0036] illustrates a timing diagram showing a control cycle of the telescopic hydraulic nozzle illustrated in the.

[0037] Of course, the features, variants and different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0038] In particular, all the variants and embodiments described can be combined with each other if there is no technical obstacle to this combination.

[0039] In the figures, elements common to several figures retain the same reference.

[0040] The invention described in the FIGURES below refers to the field of cleaning detection surfaces of sensors on board motor vehicles, known as surfaces to be cleaned. To do this, each sensor is associated with a cleaning device comprising:

[0041] - a telescopic hydraulic nozzle 2 according to the invention and of which a non-limiting example of embodiment will be described below with reference to the;

[0042] - a supply conduit 21 connecting the telescopic hydraulic nozzle 2 to a cleaning liquid tank;

[0043] - a pump configured to generate and control a flow rate and / or pressure of the cleaning liquid in the supply conduit 21 and towards the telescopic hydraulic nozzle 2.

[0044] More particularly, as visible in the, such a telescopic hydraulic cleaning nozzle 2 controlled by the control method 1 according to the invention comprises:

[0045] - a retractable conduit 23 and slidably mounted in a static conduit 22, the retractable conduit 23 being able to extend out of the static conduit 22 under the effect of hydraulic pressure exerted by the cleaning liquid circulating in the telescopic hydraulic nozzle 2 greater than a pressure threshold value;

[0046] - an elastic return element 24 configured to generate a non-zero force on the retractable conduit 23 so as to allow the retractable conduit 23 to fold into the static conduit 22 if the hydraulic pressure exerted by the cleaning liquid circulating in the telescopic hydraulic nozzle 2 is lower than the pressure threshold value.

[0047] The telescopic hydraulic nozzle 2 is connected to the cleaning system via the supply conduit 21, one terminal end of which is fluidically coupled to the telescopic hydraulic nozzle 2. In the embodiment illustrated in the, the supply conduit 21 is coupled to the telescopic hydraulic nozzle 2 at a portion opposite an outlet opening 26 of the retractable conduit 23 through which the cleaning liquid is sprayed onto the surface to be cleaned.

[0048] The telescopic hydraulic nozzle 2 takes the form of a hollow body comprising one or more channels 20 allowing the circulation of the cleaning liquid. In particular, the telescopic hydraulic nozzle 2 comprises:

[0049] - a rear channel 20 associated with the supply duct 21 and allowing the static duct 22 to be fluidically coupled with the supply duct 21;

[0050] - a distribution channel 20 associated with the retractable conduit 23 and making it possible to couple, in certain circumstances, the rear channel 20 to the distribution channel 20, so that the retractable conduit 23 is then fluidically coupled to the rear channel 20 of the static conduit 22, allowing the cleaning liquid coming from the supply conduit 21 to flow through the static conduit 22 and then the retractable conduit 23.

[0051] In order to allow the cleaning liquid to flow from the static conduit 22 to the retractable conduit 23, the telescopic hydraulic nozzle 2 further comprises a peripheral groove 25 formed on the static conduit 22, at a proximal front end of the retractable conduit 23. In addition, the retractable conduit 23 comprises, at a proximal rear end of the static conduit 22, axial grooves 27 which are intended to collaborate with the peripheral groove 25 when the retractable conduit 23 is sufficiently retracted.

[0052] The operation of the telescopic hydraulic nozzle 2 will be described in more detail below with reference to the.

[0053] The objective of the invention is thus to control the retraction movement of the telescopic hydraulic nozzle 2, and in particular of its retractable conduit 23 relative to its static conduit 22, in order to better clean the surface to be cleaned of the sensor with which it is associated. To this end, the pressure of the cleaning liquid circulating in the telescopic hydraulic nozzle 2 – in order to be projected onto the surface to be cleaned – is regulated to, concomitantly with the projection of the cleaning liquid onto the surface to be cleaned, control the retraction distance Y of the telescopic hydraulic nozzle 2.

[0054] Consequently, it is necessary to control the level of hydraulic pressure in the telescopic hydraulic nozzle 2 more or less finely in order to properly control the retraction distance Y. According to a first variant embodiment, simpler and less precise, it is possible to control the hydraulic pressure – and therefore the retraction distance Y, and consequently on which part of the surface to be cleaned the cleaning liquid is incident, directly by the pump itself. According to a second preferred variant embodiment and making it possible to obtain more precision in the control of the retraction distance Y, the cleaning device comprises a solenoid valve located in an intermediate position between the pump and the telescopic hydraulic nozzle 2, and it is the solenoid valve which is now regulated in order to control the flow rate and / or the pressure of cleaning liquid in the telescopic hydraulic nozzle 2.

[0055] With reference to the, the invention therefore addresses a method 1 for controlling a telescopic hydraulic nozzle 2 of a device for cleaning a surface to be cleaned on a motor vehicle, the control method 1 comprising a step 11 of regulating a flow rate and / or a pressure of cleaning liquid circulating in a supply conduit 21 of the telescopic hydraulic nozzle 2 so as to control the extension or folding of the telescopic hydraulic nozzle 2.

[0056] More particularly, the regulation step 11 aims to regulate the flow rate and / or the pressure of cleaning liquid circulating in the supply duct 21 of the telescopic hydraulic nozzle 2 so as to control the extension or folding of said supply duct 21 relative to the static duct 22. Thus, by controlling the flow rate of the cleaning liquid upstream of the telescopic hydraulic nozzle 2, it is possible to control the hydraulic pressure of the cleaning liquid accumulated in the static duct 22 of the telescopic hydraulic nozzle 2, against the retractable duct 23.

[0057] Illustrates three different states of the retractable telescopic hydraulic nozzle 2, depending on the pressure level established in said telescopic hydraulic nozzle 2, and corresponding to three different retraction distances Y:

[0058] – la(a) illustrates a first operating state of the telescopic hydraulic nozzle 2, in which the hydraulic pressure in the telescopic hydraulic nozzle 2 is minimal or even zero. This is the case, for example, when the telescopic hydraulic nozzle 2 is not in use. In this case, the retractable conduit 23 is completely retracted into the static conduit 22, and the retraction distance Y is zero or minimal.

[0059] – (b) illustrates a second operating state of the telescopic hydraulic nozzle 2, in which the cleaning liquid is supplied to the telescopic hydraulic nozzle 2. The operating state of the telescopic hydraulic nozzle 2 illustrated in (b) follows that illustrated in (a). In this case, the cleaning liquid is accumulated in the channel 20 of the static conduit 22 and, at the front end of the static conduit 22, presses against the rear end of the retractable conduit 23. Under the effect of this hydraulic pressure, the retractable conduit 23 retracts forward, so that the retraction distance Y increases compared to the situation illustrated in (b).However, in this case, the channel 20 of the retractable conduit 23 is still not placed in fluid communication with the channel 20 of the static conduit 22, so that the cleaning liquid does not flow into the channel 20 of the retractable conduit 23, and the telescopic hydraulic nozzle 2 still does not spray cleaning liquid onto the surface to be cleaned of the sensor with which it is associated.

[0060] – (c) illustrates a third operating state of the telescopic hydraulic nozzle 2, in which the cleaning liquid continues to be sent to the telescopic hydraulic nozzle 2. The operating state of the telescopic hydraulic nozzle 2 illustrated in (c) follows that illustrated in (b). In this case, the cleaning liquid accumulated in the channel 20 of the static conduit 22 has made it possible to increase the retraction distance Y and to propel the retractable conduit 23 forward, under the effect of the hydraulic pressure exerted by the cleaning liquid on the retractable conduit 23.The retraction distance Y is now such that the axial grooves 27 arranged on the rear part of the retractable conduit 23 are now located opposite the peripheral groove 25 of the static conduit 22, allowing the cleaning liquid present in the channel 20 of the static conduit 22 to reach the channel 20 of the retractable conduit 23 via the peripheral groove 25 and the axial grooves 27. Thus, in this configuration, the cleaning liquid flows into the channel 20 of the retractable conduit 23, and the telescopic hydraulic nozzle 2 now projects cleaning liquid onto the surface to be cleaned of the sensor with which it is associated.

[0061] The invention cleverly allows the selective creation of:

[0062] - a dynamic balance between the hydraulic pressure of the cleaning liquid present in the telescopic hydraulic nozzle 2 and the force of the elastic return element 24, so as to maintain the retractable conduit 23 at a determined retraction distance Y. In this situation, the hydraulic force exerted by the cleaning liquid on the rear part of the retractable conduit 23 of the telescopic hydraulic nozzle 2 is equal or substantially equal to the return force exerted by the elastic return element 24 and which tends to oppose the hydraulic force;

[0063] - a negative imbalance between the hydraulic pressure of the cleaning liquid present in the telescopic hydraulic nozzle 2 and the force of the elastic return element 24, so as to cause a withdrawal of the retractable conduit 23 into the static conduit 22, that is to say to cause a reduction in the retraction distance Y. In this situation, the hydraulic force exerted by the cleaning liquid on the rear part of the retractable conduit 23 of the telescopic hydraulic nozzle 2 is less than the return force exerted by the elastic return element 24 and which tends to oppose the hydraulic force;

[0064] - a positive imbalance between the hydraulic pressure of the cleaning liquid present in the telescopic hydraulic nozzle 2 and the force of the elastic return element 24, so as to cause a retraction of the retractable conduit 23 out of the static conduit 22, that is to say to cause an increase in the retraction distance Y. In this situation, the hydraulic force exerted by the cleaning liquid on the rear part of the retractable conduit 23 of the telescopic hydraulic nozzle 2 is greater than the return force exerted by the elastic return element 24 and which tends to oppose the hydraulic force.

[0065] Subsequently, the control method 1 according to the invention aims to create several control modes M1, M2, M3 of the telescopic hydraulic nozzle 2, corresponding to as many scenarios for managing the retraction distance Y with the aim of proposing optimal cleaning of the surface to be cleaned.

[0066] Several of these control modes M1, M2, M3 are illustrated schematically on the, which represents the retraction distance Y – on the ordinate – as a function of time T – represented on the abscissa axis. For the sake of clarity, a single operating cycle has been shown on the, i.e. a single cycle of maximum retraction and complete retraction of the telescopic hydraulic nozzle 2. Of course, it is possible to carry out several of these cycles successively, by mixing them or by taking them all separately from each other.

[0067] The first control mode M1 illustrated on illustrates the known use case of telescopic hydraulic nozzles 2: the retractable conduit 23 is first retracted – the retraction distance Y increasing over time T – then, when it reaches its maximum retraction distance Y, is folded back towards the static conduit 22. Optionally, the retracted conduit can be maintained for a non-zero duration at its maximum retraction distance Y. In this first operating mode, the telescopic hydraulic nozzle 2 is not controlled according to the control method 1;

[0068] The second control mode M2 ​​and the third control mode M3 come from the control method 1 according to the invention.

[0069] The second control mode M2 ​​and the third control mode M3 illustrated on the show, between the zero retraction distance Y and the maximum retraction distance Y, multiple back-and-forth movements of amplitude less than that of the maximum retraction distance Y. In other words, when the retractable conduit 23 is unfolded out of the static conduit 22, the hydraulic pressure inside the telescopic hydraulic nozzle 2 is controlled so as to generate micro-movements back and forth of the retractable conduit 23 out of the static conduit 22. In other words, the regulation step 11 of the control method 1 according to the invention comprises at least one iteration of the following steps:

[0070] - a step 12 of increasing the flow rate and / or the pressure beyond the pressure threshold value for a first duration,

[0071] - a step 13 of reducing the flow rate and / or the pressure below the pressure threshold value for a second duration.

[0072] By calibrating the first duration and the second duration, it is possible to adjust the slope of the curve illustrated on the, and therefore the deployment speed of the retractable conduit 23 of the telescopic hydraulic nozzle 2.

[0073] In the second control mode M2 ​​illustrated in the, the regulation step 11 implements these iterations from the start, that is to say from the minimum retraction distance Y of the retractable hydraulic nozzle. On the other hand, in the third control mode M3 illustrated in the, the regulation step 11 does not implement these iterations from the start. Conversely, the regulation step 11 first comprises a step 12 of increasing the pressure beyond the threshold value in order to allow the hydraulic pressure prevailing inside the telescopic hydraulic nozzle 2 to be greater than the restoring force of the elastic restoring element 24. This step 12 of increasing the pressure is maintained as long as the retractable conduit 23 is not sufficiently retracted to allow the flow of cleaning liquid through the channel 20 of said retractable conduit 23.In other words, the pressure increase step 12 is maintained as long as the axial grooves 27 of the retractable conduit 23 are not located opposite the peripheral groove 25 of the static conduit 22.

[0074] In the context of the present invention, it is understood that the pressure increase step 12 is a step of configuring the hydraulic pressure prevailing inside the telescopic hydraulic nozzle 2, and in particular at the static conduit 22, to a value greater than the aforementioned threshold value. The pressure increase step 12 may be a step of varying the pressure beyond the threshold value or a step at constant pressure, always greater than the threshold value.

[0075] Similarly, it is understood that the pressure reduction step 13 is a step of configuring the hydraulic pressure prevailing inside the telescopic hydraulic nozzle 2, and in particular at the level of the static conduit 22, to a value lower than the aforementioned threshold value. The pressure reduction step 13 may be a step of varying the pressure below the threshold value or a step at constant pressure, always lower than the threshold value.

[0076] It is therefore noted that the curves of the second and third control modes M2 and M3 represent embodiments where the first duration, associated with a pressure above the pressure threshold value, is a multiple (i.e., the first duration is more than 1 time the second duration, and preferably between 1.5 and 10 times) of the second duration, associated with a pressure below the threshold value. A generally rising curve shape is therefore obtained during the execution of the method of the invention, as illustrated by the curves of the second and third modes M2 and M3 of the.

[0077] On the other hand, one could also envisage an embodiment (not illustrated) where the first duration is a fraction (i.e. between less than 1 times the second duration, and preferably between 0 and 0.1 times) of the second duration. A generally descending curve shape is therefore obtained when carrying out the method of the invention. Such a curve allows the method according to the invention to be carried out in the "reverse direction", i.e. while the telescopic nozzle moves from an extended position to a retracted position.

[0078] Other embodiments not illustrated are also conceivable. For example, by modulating the pressure of the cleaning liquid, the position of the telescopic nozzle can be controlled, in order to "park" the nozzle in a specific position and for a specific duration. Consequently, the nozzle will project a much larger volume of liquid onto a targeted portion of the surface to be cleaned, thus making it possible to effectively clean particularly severe and / or stubborn dirt.

[0079] In summary, the invention relates to a method 1 for controlling a telescopic hydraulic nozzle 2 of a device for cleaning a surface to be cleaned on a motor vehicle, the control method 1 comprising a step 11 of regulating a pressure of cleaning liquid circulating in a supply conduit 21 of the telescopic hydraulic nozzle 2 so as to control the extension or folding of the telescopic hydraulic nozzle 2. The regulating step 11 comprises a plurality of cycles comprising a step 12 of increasing the pressure beyond a threshold value and a step 13 of decreasing the pressure below the threshold value in order to control a retraction distance Y of the telescopic hydraulic nozzle 2 according to multiple partial back and forth movements on the surface to be cleaned.

[0080] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. In particular, the different characteristics, forms, variants and embodiments of the invention can be associated with each other in various combinations insofar as they are not incompatible or mutually exclusive. In particular, all the variants and embodiments described above can be combined with each other.

Claims

Method for controlling (1) a telescopic hydraulic nozzle (2) of a device for cleaning a surface to be cleaned on a motor vehicle, the control method (1) comprising a step of regulating (11) a pressure of cleaning liquid circulating in a supply conduit (21) of the telescopic hydraulic nozzle (2) so as to control the extension or folding of the telescopic hydraulic nozzle (2). Control method (1) according to the preceding claim, in which the regulation step (11) comprises a step of increasing (12) the pressure of the cleaning liquid beyond a pressure threshold value in order to retract the telescopic hydraulic nozzle (2). Control method (1) according to the preceding claim, in which the regulation step (11) comprises a step of reducing (13) the pressure of the cleaning liquid below the pressure threshold value in order to fold the telescopic hydraulic nozzle (2). Control method (1) according to the preceding claim, in which the pressure threshold value is equal to 1.5 bar. Control method (1) according to any one of claims 3 or 4, in which the regulation step (11) comprises at least one iteration of the following steps: - the step of increasing (12) the pressure beyond the pressure threshold value for a first duration; - a step of decreasing (13) the pressure below the pressure threshold value for a second duration. Control method (1) according to the preceding claim, in which the first duration is between 0.1 and 10 times the second duration. Control method (1) according to claim 6, wherein the first duration is equal to twice the second duration. Telescopic hydraulic nozzle (2) for cleaning a surface to be cleaned of a sensor of a motor vehicle, the telescopic hydraulic nozzle (2) being controlled by the control method (1) according to any one of the preceding claims and comprising: - a retractable conduit (23) and slidably mounted in a static conduit (22), the retractable conduit (23) being able to extend out of the static conduit (22) under the effect of a hydraulic pressure exerted by the cleaning liquid circulating in the telescopic hydraulic nozzle (2) greater than a pressure threshold value; - an elastic return element (24) configured to generate a non-zero force on the retractable conduit (23) so as to allow folding of the retractable conduit (23) in the static conduit (22) if the hydraulic pressure exerted by the cleaning liquid circulating in the telescopic hydraulic nozzle (2) is less than the pressure threshold value. Device for cleaning a surface to be cleaned of a sensor of a motor vehicle, the cleaning device comprising:- the telescopic hydraulic nozzle (2) according to the preceding claim;- a supply conduit (21) connecting the telescopic hydraulic nozzle (2) to a cleaning liquid reservoir;- a pump configured to generate and control a flow rate of the cleaning liquid in the supply conduit (21) and towards the telescopic hydraulic nozzle (2).

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