METHOD FOR RECOVERING RAINWATER FROM THE SURFACE OF A VEHICLE, RECOVERY CIRCUIT AND VEHICLE EQUIPPED WITH SUCH A CIRCUIT

Abstract

The invention proposes a method for recovering a liquid collected on a surface (1, 19), interior or exterior, of a bodywork element (17) or glazing (2) of a motor vehicle, characterized in that it consists of analyzing a quantity of collected liquid flow by means of a device (30) for measuring or estimating a parameter representative of a pollution state of the collected liquid, such as its turbidity, comparing a measured value of the turbidity to a threshold value and, when the measured value is less than this threshold value, directing the collected liquid flow towards a recovery unit (9), or, when the measured value is greater than the threshold value, disposing of the collected liquid flow, for example as waste.

Description

1 "Method for recovering rainwater from the surface of a vehicle, recovery circuit and vehicle equipped with such a circuit" TECHNICAL FIELD OF THE INVENTION The invention relates to the recovery of liquids present on the surfaces, particularly exterior surfaces, of a motor vehicle. TECHNICAL BACKGROUND OF THE INVENTION The invention relates, for example, to the recovery of rainwater or condensation present on the bodywork or windshield, or even of liquid previously sprayed onto these surfaces for washing or cleaning, such as windshield washer fluid. Numerous designs for devices or arrangements for collecting these liquids are known, particularly for their various uses within the vehicle. For instance, water collected from rain falling on the roof or headliner of the vehicle can be reused for various washing equipment or equipment designed to regulate temperature or humidity. It is particularly useful and desirable to recover water for reuse in a windshield washer system connected to a wiper system, for example, to maintain the best possible visibility through the windshield. Such collected water contains varying amounts of foreign matter, including impurities and polluting particles. To be able to reuse it effectively, the quantity of recovered water must be sufficiently clean to avoid damaging the systems involved, such as the washers. Therefore, it has already been suggested that the collected water be filtered before being reintroduced into a windshield washer fluid reservoir. Different qualities or levels of purity can be achieved by using multiple filters with different characteristics. See, for example, the contents of documents WO-A-2014 / 11614 or de-A-102008029254. 10 TheThe filters or filtration systems used are bulky and heavy and also require changing and / or maintenance. BRIEF SUMMARY OF THE INVENTION 15 In order to remedy these drawbacks, the invention proposes an economical recovery method aimed at implementing a sorting or selection principle for the collected liquid. 20 The invention proposes a method for recovering a liquid collected on an interior or exterior surface of a bodywork or glazing element of a motor vehicle, characterized in that it consists of: - a) analyzing a quantity of liquid flow collected by means of a device for measuring or estimating a parameter representative of a pollution state of the collected liquid to provide a measured or estimated value of the pollution level of the liquid; - b) comparing said measured or estimated value to at least a threshold value of the pollution level of the liquid; - c) and, when the measured or estimated value is less thansaid threshold value, to direct at least part of the collected liquid stream towards a collected liquid recovery unit. 3062356 3 Thus, after analysis and evaluation of the quality of the collected liquid, a decision is made whether or not to recover the liquid for use. All quantities of collected liquid that do not meet the desired quality threshold are disposed of as waste, for example, wastewater, which can, for example, be discharged directly into the environment (from where it was previously collected). According to other characteristics of the process: 10 - the process consists of repeating step b) of comparison and, when the measured or estimated value is greater than said threshold value, d) of interrupting said direction and discharging the collected liquid stream; - the parameter representing the pollution state of the collected liquid 15 is its turbidity; - step a) consists of circulating a quantity of the liquid streamcollected in front of the measuring or estimating device; - step a) consists of storing at least part of the collected liquid flow in an intermediate collection tank 20 equipped with the measuring or estimating device; - the method consists of performing step b) according to a level of presence of collected water; - step b) is triggered with a time delay relative to measurement step a); 25 - step d) is triggered immediately after the detection of a measured or estimated value greater than said threshold value; - the recovery unit is a unit of use or a unit of storage of the collected liquid. 30 The invention also proposes a circuit for recovering a liquid collected on an interior or exterior surface of a bodywork or glazing element of a motor vehicle, characterized in that it comprises: 3062356 4 - a measuring zone equipped with a device for measuring or estimating a parameter representative of the state ofpollution of the collected liquid to provide a measured or estimated value of the pollution level of the liquid; 5 - an outlet pipe connected to said measurement zone; - a controlled device which is connected to said outlet pipe and which, depending on said measured or estimated value of the pollution level of the collected liquid, allows or interrupts 10 the flow of the collected liquid towards a collected liquid recovery unit. According to other characteristics of the circuit: - said device is a controlled solenoid valve; - the solenoid valve is actuated by an electromagnet and 15 a return spring to a stable discharge position; - the measuring or estimation device is a sensor for measuring the turbidity of the collected liquid; - the measurement zone is a section of pipe in which at least part of the collected liquid flow circulates; 20 - the measurement zone is an intermediate collection tank of at least onepart of the collected liquid flow; - the circuit includes means for timing the change of state of the solenoid valve to allow the circulation of the collected liquid flow towards a unit 25 for recovering the collected liquid; - the recovery unit is a unit for using or storing the collected liquid; The invention further proposes a motor vehicle, characterized in that it is equipped with means for collecting a liquid 30 from an interior or exterior surface of a bodywork or glazing element of the vehicle, and with a recovery circuit according to the invention. According to other characteristics of the vehicle: 3062356 5 - it includes at least one system for wiping the exterior surface of a window of the vehicle, and said collected liquid recovery unit includes a windshield washer fluid storage unit associated with said wiping system; 5 - it includes at least one thermal heating or heating circuitcooling of the vehicle's passenger compartment, or of an engine (for example, an internal combustion engine) fitted to the vehicle, or of an accessory or piece of equipment fitted to the vehicle, and said recovery unit is a storage unit for the supply fluid 10 of said thermal circuit. BRIEF DESCRIPTION OF FIGURES 15 Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for the understanding of which reference should be made to the accompanying drawings in which: - Figure 1 schematically illustrates a system for 20 collecting fluid from the exterior surfaces of a motor vehicle, which is associated with a first embodiment of a recovery circuit according to the invention; - Figure 2 schematically illustrates a second embodiment of a recovery circuit according to the invention; 25 and - Figure 3 is a schematic view of a system for wiping and cleaning a window, here of aMotor vehicle windscreen 30 DETAILED DESCRIPTION OF FIGURES 3062356 6 In the following description, elements with an identical structure or analogous functions will be designated by the same references. By way of non-limiting example, the invention relates to the recovery of liquid, for example rainwater, which can be reused for the operation of a system for cleaning the outer surface of a motor vehicle window, which is here a windshield, as illustrated in Figure 3. The system includes a cleaning device comprising two wiper blades, or wiping blades, each mounted on an associated wiper arm. Each wiper blade is capable of moving angularly along the outer surface of the windshield between an extreme low wiping position PB and an extreme high wiping position PH, and vice versa. During these sweeping movements, the bladesThe wiping arms fitted to the wiper blades 3 "wipe" the rain from the outer surface of the windshield and move this water to the lower and / or lateral part of the windshield 20 where it can be collected for possible reuse, as well as rainwater collected from the outer surface of the vehicle's roof (not shown). The cleaning system also includes an electric motor 25 5 which drives the wiper arms, and therefore the wiper blades 3, in an alternating angular sweep. The cleaning system also includes a set of means for projecting liquid onto the outer surface of the windshield. 30 These means here include a system 6 of piping which is connected to nozzles 7 intended to eject and project liquid onto the windshield 2. 3062356 7 The system of piping 6 is supplied with liquid to be projected by two separate upstream circuits of whichEach component is associated with a specific function required of the cleaning system. 5 For a normal or conventional washing function aimed at removing water from the outer surface of the windshield, a first circuit 8 includes a first reservoir 9 – containing washing fluid – and a first pump 10 for circulating the washing fluid through the piping system(s) 6. 10 For a cleaning function such as defrosting, a second circuit 11 includes a second reservoir 12 – containing defrosting fluid – and a second pump 13 for circulating the defrosting fluid through the piping system(s) 6. 15 Such a defrosting function is used to remove frost formed on the outer surface of the glass, in this case, the windshield. Compared to a normal or conventional washing function, the defrosting function is unique in that it removes material adhering to the outer surface 1 of the windshield.20 windshield 2, for which the fluid used for the washing function is not suitable. The wiping and cleaning system includes an electronic control unit 14 capable of controlling the electric motor 5 that drives the wiper blades 3 and 25, activating the pumps 21, 22 of the two fluid supply circuits 8, 11 to make the system perform different operating cycles, including cycles adapted either to the normal washing function, with the washing fluid present in the first reservoir 11, or to the defrosting function with 30 the specific fluid contained in the second reservoir 12. The electronic control unit 14 can be more or less simple, depending on the complexity of the operations planned to execute the different cycles and perform the different functions. 3062356 8 In addition, the vehicle can be equipped with an outside temperature sensor 15, which is here located on a high part of the windshield 2. The control unitThe control electronics 14 can be connected to the external temperature sensor 5, 15, and use the data provided by this sensor to adapt parameters of the different cycles and perform the various functions executed by the system. The recovery of liquid, and for example rainwater, as proposed by the invention aims, for example, to be able to use the recovered water as washing or rinsing water in the first tank 9, either as is and / or mixed with appropriate additives. In Figure 1, in the upper left part, a windshield 2 is shown, the outer surface of which is swept by a wiper blade 3, and a first collection pipe 20 through which the water collected by sweeping flows, for example by gravity, and is gathered at the lower part of the windshield 2. In the upper right part, a portion of the vehicle's bodywork 17 is schematically represented, which is, for example,a portion of the roof, on the outside surface of which rain is collected and then collected towards a second collection pipe 22. 25 The two collection pipes 20 and 22 here feed a reservoir 24 for collecting the water to be recovered. The collection tank 24 is equipped with a level sensor 26 that transmits signals representing the quantity of liquid contained in the collection tank 24 to electronic analysis and control means 30, such as an Electronic Control Unit (ECU) 28 schematically represented in Figure 1. The collection tank 24 is also equipped with a turbidity sensor 30 for measuring the water contained in the collection tank 24. The turbidity sensor emits signals representing the turbidity of the liquid to the ECU 28. As is known, a turbidity sensor assesses water quality by measuring its turbidity level. It is capable of detectingturbidity is measured by measuring light transmission and scattering rate (l0) as the amount of suspended solids changes. As the amount of suspended solids increases, the turbidity level or value of the liquid also increases. Turbidity refers to the concentration of substances that make a fluid, particularly a liquid, in the water. Suspended solids are defined as all particulate matter passively carried in the water. Turbidity corresponds to the optical property of water that causes incident light to be scattered or absorbed. Its meaning depends on the measurement technique used. Several optical measurements can be used to measure turbidity. A turbidity sensor can have different signal output modes, analog and / or digital. For example, a digital turbidity sensor with an adjustable threshold can be used.25 digital. The ECU 28 can also be designed to convert an analog signal representing the turbidity provided by the turbidity sensor 30 into a digital signal. Here, in the lower part, the collection tank 24 is connected to an electrohydraulic solenoid valve 32 by an outlet pipe 34. The solenoid valve 34 is a three-way, two-position type, with an inlet 38 and two outlets 38 and 40. The connecting pipe 34 is connected to the inlet 36, while the first outlet is connected to a pipe 42, referred to as the discharge pipe, and the second outlet is connected to a pipe 44, referred to as the recovery pipe. 5 The solenoid valve 32 is shown in its stable rest position in which the inlet 36 communicates with the first outlet 38, i.e., in which the outlet pipe 34 is connected to the drain pipe 42. The solenoid valve is connected to the ECU 28, which can control the change of position from its rest position.stable resting position, towards its second position (not shown) in which the inlet 36 communicates with the second outlet 40, i.e. in which the outlet pipe 34 is connected to the recovery pipe 44. 15 According to an unshown variant, the solenoid valve 32 could be of the three-way, three-position type, with the same arrangement of the channels, but with a third position in which neither of the two outlets 38 or 40 is connected to the inlet 36, i.e. a third position in which the outlet pipe 20 is "closed" and no collected liquid flows from the collection tank 24 through the solenoid valve 32. The flows and circulation of liquid are described and illustrated as taking place by gravity. Without departing from the scope of the invention, they can notably be carried out by suitable pumps or circulators controlled by the ECU. The recovery pipe opens downstream into the first reservoir.9 to be able to use the recovered water as washing or rinsing water, as is and / or mixed 30 with suitable additives. Like the collection tank 24, the tank 9, which can be filled with recovered water, can be equipped with a level sensor 46 that transmits signals 3062356 11 representative of the quantity of liquid contained in the tank 9 towards the ECU 28. The invention is not limited to the use of an intermediate collection tank 24 as described. 5 Alternatively, it is possible to connect a collection source directly to the outlet pipe 34, by equipping the path between the collection source and the solenoid valve 32 with the turbidity sensor 30. 10 The arrangement and circuit just described with reference to Figure 1 allow the implementation of a recovery process according to the invention. The analysis of water by the turbidity sensor 30 provides a parameter representative of a state ofwater pollution in the form of a signal transmitted to the UCE 28 in which a comparison is made between the value provided by the turbidity sensor 30 and an acceptable threshold value of the pollution level of the water collected for recovery as all or part of the washing liquid. 20 As long as the measured pollution level is below the threshold value stored or mapped in the ECU, the solenoid valve 32 is activated to direct the flow of collected liquid towards the recovery pipe 44 and the tank 9. 25 The comparison operation with the threshold value is repeated regularly (continuously or sequentially) so that as soon as the value measured by the turbidity sensor 30 becomes greater than said threshold value, the ECU interrupts the control of the solenoid valve 32, which returns to its stable position 30 illustrated in Figure 1 in order to discharge all the collected water in the form ofwaste. The use of a collection tank 24 allows for the temporary storage of collected water, which is, for example, identified as being of good quality, particularly when, for example, the tank 9 is "full" according to the information provided by the sensor 46. This can be achieved using a three-position solenoid valve as mentioned previously or with a circuit according to the second embodiment shown in Figure 5. Similarly, any liquid storage in the collection tank 24 is managed according to its fill level as provided by the level sensor 26. In case of overfilling, the collected water, even if of good quality, can be discharged into an intermediate storage tank equipped with the measuring or estimating device. According to the second embodiment illustrated in Figure 2, the outlet pipe 34 is divided into: - a first outlet pipe 34A connected to the discharge pipe42 through a first solenoid valve 32A; and - a second outlet pipe 34B connected to the recovery pipe 44 through a second solenoid valve 32B. Each of the two solenoid valves 32A and 32B is controlled by the UCE 28. Each solenoid valve 32A, 32B is of the two-way, two-position type with an input 36A, 36B respectively connected to the associated outlet pipe 34A, 34B, and an output 40, 38 respectively connected to the drain pipe 42 and the recovery pipe 44. In its stable rest position, each solenoid valve 32A, 32B interrupts communication between its input and its output, and therefore respectively between the outlet pipe 34A and the drain pipe 42 on the one hand, and between the outlet pipe 34B and the recovery pipe 44 on the other. 3062356 13 Here again, it is not mandatory to use an intermediate collection tank 24. AsPreviously, the UCE (Control and Evaluation Unit) managed and controlled the various flows through solenoid valves 5, 32A, and 32B to take into account the pollution / turbidity level of the collected water as well as the fill levels of the different tanks. For certain applications, the discharge pipe 44 can be connected to treatment means such as filtration or pollution control 10 for the purpose of recycling this "polluted" liquid flow and its downstream use, possibly with intermediate storage (not shown).

Claims

CLAIMS 1. Method for recovering a liquid collected on a surface (1, 19), interior or exterior, of a bodywork element (17) or glazing (2) of a motor vehicle, characterized in that it consists of: - a) analyzing a quantity of collected liquid flow by means of a device (30) for measuring or estimating a parameter representative of a pollution state of the collected liquid to provide a measured or estimated value of the pollution level of the liquid; - b) comparing said measured or estimated value with at least one threshold value of the pollution level of the liquid; - c) and, when the measured or estimated value is lower than said threshold value, to direct at least part of the flow of collected liquid towards a unit (9) for recovering the collected liquid.

2. Method according to claim 1, characterized in that it consists of repeating step b) of comparison and, when the measured or estimated value is greater than said threshold value, - d) to interrupt said orientation and to evacuate the flow of collected liquid.

3. Method according to claim 1, characterized in that the parameter representative of the pollution state of the collected liquid is its turbidity.

4. Method according to claim 1, characterized in that step a) consists of circulating a quantity of the collected liquid flow in front of the measuring or estimating device (30).

5. Method according to claim 1, characterized in that step a) consists of storing at least part of the collected liquid flow in an intermediate collection tank (24) equipped with the measuring or estimation device.

6. Method according to claim 1 characterized in that it consists of carrying out step b) as a function of a level of presence of collected water.

7. Method according to claim 1, characterized in that step c) is triggered with a time delay relative to the measurement step a).

8. Method according to claim 2, characterized in that step d) is triggered immediately after the detection of a measured or estimated value greater than said threshold value.

9. Method according to claim 1, characterized in that said recovery unit is a unit for use or a unit for storage of the collected liquid.

10. Circuit for recovering a liquid collected on an interior or exterior surface (1, 19) of a bodywork element (17) or glazing (2) of a motor vehicle, characterized in that it comprises: - a measuring zone equipped with a device (30) for measuring or estimating a parameter representative of the pollution state of the collected liquid to provide a measured or estimated value of the pollution level of the liquid, said measuring zone being an intermediate tank (24) for collecting at least part of the flow of collected liquid; - an outlet pipe (34) connected to said measuring zone; - a controlled device (32, 32A, 32B) which is connected to said outlet pipe (34) and which, depending on said measured or estimated value of the pollution level of the collected liquid, authorizes or interrupts the circulation of the flow of collected liquid towards a unit (9) for recovering the collected liquid.

11. Circuit according to claim 10, characterized in that said device is a controlled solenoid valve (32, 32A, 32B)).

12. Circuit according to claim 11, characterized in that the solenoid valve is controlled by an electromagnet and return spring to a stable evacuation position.

13. Circuit according to claim 10, characterized in that said measuring or estimating device is a sensor (30) for measuring the turbidity of the collected liquid.

14. Circuit according to claim 11, characterized in that it comprises means for delaying the change of state of the solenoid valve to authorize the circulation of the flow of collected liquid towards a unit for recovering the collected liquid.

15. Circuit according to claim 10, characterized in that said recovery unit is a unit for use or a unit for storage of the collected liquid.

16. Motor vehicle, characterized in that it is equipped with means for collecting a liquid on a surface, interior or exterior, of a bodywork or glazing element of the vehicle, and a recovery circuit according to any one of claims 10 to 15.

17. Vehicle according to claim 16, characterized in that it comprises at least one system (100) for wiping the outer surface of a window of the vehicle, and in that said unit for recovering the collected liquid comprises a unit (9) for storing windshield washer fluid associated with said wiping system.

18. Vehicle according to claim 16, characterized in that it comprises at least one thermal circuit for heating or cooling the passenger compartment of the vehicle or an engine equipping the vehicle or an accessory or equipment equipping the vehicle, and in that said recovery unit is a unit for storing liquid supplying said thermal circuit.

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