Patent Description:
The Applicant has already developed and proposed anti-aquaplaning systems for vehicles which are based on the injection of liquid at the front of the tread of front wheels of a motor vehicle, wherein the injected liquid is drawn from the tank of the windscreen washer liquid of the motor vehicle. An example of such systems is described in the <CIT>. Further examples are known from <CIT> and <CIT>. In particular the system of <CIT> comprises a storage unit only with a main tank <NUM> configured for storing a main operating liquid and no auxiliary tanks.

One of the most common technical problems affecting such systems resides in the characteristics of the windscreen washer liquid. The latter normally comprises a solution of water and a surfactant-based cleaning agent to clean the windscreen or the rear window: at the injection pressures typical of the windscreen washing system, the presence of surfactants in the liquid does not lead to the formation of high amounts of foam, but in an anti-aquaplaning system the injection pressures may reach around <NUM>-<NUM> bar, therefore generating significant amounts of foam. This has very adverse effects on the performances of the system because it jeopardizes the action of the liquid injection, therefore making the system ineffective in mitigating the aquaplaning effects. A further constraint involves the tank for the windscreen washer liquid: the latter cannot be modified for the supply of the anti-aquaplaning system, because this would involve a difference in the specifications according to the motor vehicle type and to the equipment thereof (with / without anti-aquaplaning system). Moreover, it would be necessary to differentiate the liquids contained in the tanks, a difference being made between the liquids for cars without anti-aquaplaning systems and the liquids for cars with anti-aquaplaning systems.

The present invention aims at solving the technical problems mentioned in the foregoing. Specifically, the invention aims at optimizing the simultaneous presence and operation of an anti-aquaplaning system and of the windscreen washing apparatus on board a vehicle by providing a plurality of functions.

The object of the present invention is achieved by a system and a method having the features set forth in the claims that follow, which are an integral part of the technical disclosure provided herein in relation to the invention.

The invention will now be described with reference to the annexed Figures, which are provided by way of non-limiting example only, wherein:.

Reference <NUM> in <FIG> generally denotes an anti-aquaplaning system for a motor vehicle according to first embodiments of the invention.

In the present and in other embodiments, the system includes:.

It must be kept in mind, moreover, that the dispensing unit <NUM> may generally be installed at any axle of the motor vehicle (either on the front axle or on the rear axle, or on both); therefore, it is possible to install it at a rear axle, the first and the second injectors <NUM>, <NUM> being accordingly configured for the injection of liquid towards the ground, respectively at the front of a right tread and a left tread of a right wheel and a left wheel of a rear axle of the motor vehicle, and/or of a front axle of the motor vehicle.

According to the invention, the storage unit <NUM> includes a main tank <NUM>, configured for storing a main operating liquid, and at least one auxiliary tank <NUM>, <NUM>, (n), <NUM>, wherein reference (n) generally denotes the presence of an nth tank, to indicate the variable number of auxiliary tanks (the present embodiment comprises three auxiliary tanks in addition to the nth tank, but the number may generally vary from a minimum of one to a maximum dictated by operational needs). Each auxiliary tank is configured for storing a corresponding auxiliary operating liquid. The main operating liquid may comprise a conventional windscreen washer solution (water and cleaning agent) or simply water. In preferred embodiments, the main tank <NUM> is chosen as the tank for windscreen washer fluid of the motor vehicle.

The auxiliary tanks <NUM>, <NUM>, (n), <NUM> store an auxiliary operating liquid, which is functionally an additive and which is specific for the users connected to the dispensing unit, and configured for mixing with the main operating fluid. Examples of auxiliary operating fluids, the purpose whereof will become apparent from the description in the following, include:.

The mixing unit <NUM> includes a manifold <NUM> to which there are connected, hydraulically and individually, the main tank <NUM> and the at least one auxiliary tank <NUM>, <NUM>, (n), <NUM>. Specifically, the following connections lead into manifold <NUM>:.

The mixing unit <NUM> moreover comprises an electrically operated valve for each auxiliary tank, specifically:.

Each electrically operated valve is configured for selectively enabling the flow of auxiliary operating liquid from the respective auxiliary tank towards the manifold <NUM>. Therefore, each valve may be operated so as to take a closed position, wherein the flow is blocked, and an open position, wherein the flow is enabled.

In this embodiment, the supply unit <NUM> includes a pump comprising an inlet port <NUM> and a delivery port <NUM>. In the diagram of <FIG>, it may be observed that the manifold <NUM>, and with it the tanks <NUM>, <NUM>, <NUM>, <NUM>, (n), are hydraulically connected to the pump inlet port <NUM>. For the auxiliary tanks, the hydraulic connection is enabled when the valves <NUM>, <NUM>, <NUM> (nv) are in an open position, while the hydraulic connection of the main tank <NUM> is always enabled.

Each valve <NUM>, <NUM>, <NUM>, (nv) is therefore configured for selectively enabling a flow of auxiliary operating liquid in the hydraulic connection between the corresponding auxiliary tank and the manifold <NUM>, so as to mix the main operating liquid, coming from tank <NUM>, and a corresponding - selected - auxiliary operating liquid, thereby defining an operating mixture of the system. It must be kept in mind, moreover, that in certain embodiments, depending on the nature of the main and auxiliary operating liquids, the operating mixture may comprise the main operating liquid and two or more auxiliary operating liquids. The supply unit <NUM>, therefore, is configured for drawing the operating mixture from the manifold <NUM> through the intake port <NUM> and for delivering it to the dispensing unit <NUM>, specifically to the injectors <NUM>, <NUM>.

Tank <NUM> is moreover connected to a conventional windscreen washing pump <NUM>, which is smaller than the pump of the supply unit <NUM> and which is configured for drawing the main operating liquid directly from tank <NUM> for washing the windows of the motor vehicle.

The operation of system <NUM> is as follows.

Thanks to the mixing unit, it is possible to define an operating mixture, in the present case to be delivered to the injectors <NUM>, <NUM> of the anti-aquaplaning systems, having optimized features for the specific use. In a preferred embodiment, comprising tank <NUM> and only one auxiliary tank <NUM>, the former is normally filled with a conventional windscreen washer water solution, so that pump <NUM> may draw directly therefrom, thus enabling the normal windscreen washing functions, while the latter is filled with a liquid defoaming agent.

When the need arises to operate the anti-aquaplaning system <NUM>, the operating mixture which in the present case contains the windscreen washer solution stored in tank <NUM> and the defoaming agent stored in tank <NUM> is obtained by opening valve <NUM> and enabling mixing within manifold <NUM>. accordingly, the pump of supply unit <NUM> draws the operating mixture through port <NUM> and delivers it directly to the injectors <NUM>, <NUM> at a pressure of <NUM> - <NUM> bar. With the operation of the system, and unlike the related art, the presence of a defoaming agent destroys the surfactants in the windscreen washer solution, thus inhibiting the formation of foam.

In a further embodiment of system <NUM>, the set of auxiliary tanks may also envisage tank <NUM> filled with water only (with the possible addition of an anti-freezing agent). In this case, the operating mixture may consist of the combination of the windscreen washer solution drawn from tank <NUM>, the defoaming agent drawn from tank <NUM> and the water drawn from tank <NUM> (the procedure is the same: the flow is enabled in connection <NUM> via valve <NUM>, and the mixing takes place in manifold <NUM>). The water in tank <NUM> may be used to dilute the windscreen washer solution, so as to further reduce the foam deriving from the injection via injectors <NUM>, <NUM>.

In still a further embodiment, it is possible to envisage the presence of additional tank <NUM> containing a cleaning agent for cleaning injectors <NUM>, <NUM> internally. In this case, the operating mixture may comprise a larger amount of water from tank <NUM> and of defoaming agent from tank <NUM>, so as not to jeopardize the action of the cleaning agent for the injectors, but it is also possible to draw and deliver only the cleaning agent from tank <NUM>.

Referring to <FIG>, reference <NUM> denotes an anti-aquaplaning system according to second embodiments of the invention. The system <NUM> is identical to system <NUM> as regards the storing unit and the mixing unit, but it differs in the supply unit and in the dispensing unit. The system will anyway be described in its entirety for better reference.

The anti-aquaplaning system <NUM> includes:.

The storage unit <NUM> includes a main tank <NUM>, configured for storing a main operating liquid, and at least one auxiliary tank <NUM>, <NUM>, (n), <NUM>, wherein reference (n), again, generally denotes the presence of an nth tank, to indicate the variable number of auxiliary tanks (the present embodiment comprises three auxiliary tanks in addition to the nth tank, but the number may generally vary from a minimum of one to a maximum dictated by operational needs). Each auxiliary tank is configured for storing a corresponding auxiliary operating liquid.

The main operating liquid may comprise either a conventional windscreen washer solution (water and cleaning agent) or simply water. Again, the main tank <NUM> is preferably chosen to be the tank for the windscreen washer liquid of the motor vehicle.

The auxiliary tanks <NUM>, <NUM>, (n), <NUM> store an auxiliary operating liquid, which is functionally an additive and which is specific for the users connected to the dispensing unit <NUM>, and configured for mixing with the main operating fluid. Examples of auxiliary operating fluids, the purpose whereof will become apparent from the description in the following, include:.

Each electrically operated valve is configured for selectively enabling the flow of an auxiliary operating liquid from the respective auxiliary tank towards the manifold <NUM>. Therefore, each valve may be driven so as to take a closed position, wherein the flow is blocked, and an open position, wherein the flow is enabled.

In the present embodiments, the supply unit <NUM> includes a pump comprising an inlet port <NUM> and a plurality of delivery ports. Specifically, the pump of supply unit <NUM> includes a first delivery port <NUM>, a second delivery port <NUM> and a third delivery port <NUM>.

The first delivery port <NUM> is hydraulically connected to a first accumulator <NUM> and to a second accumulator <NUM>, respectively associated to injector <NUM> and to injector <NUM>; the accumulators <NUM> and <NUM> are configured for storing the operating mixture in pressurized conditions, and are hydraulically connected to the corresponding injector <NUM>, <NUM>.

The second delivery port is hydraulically connected to a set of windscreen washer nozzles <NUM>, while the third delivery port is hydraulically connected to a set of sensor washing nozzles <NUM>, e.g. configured for washing the sensors for advanced driver assistance systems (ADAS).

The injectors <NUM>, <NUM> with the respective accumulators <NUM>, <NUM>, the set of windscreen washer nozzles <NUM> and the set of sensor washing nozzles <NUM> are the users of the dispensing unit <NUM>.

In the diagram of <FIG> it may be observed that the manifold <NUM>, and with it the tanks <NUM>, <NUM>, <NUM>, <NUM>, (n), are hydraulically connected to the inlet port <NUM> of the pump. For the auxiliary tanks, the hydraulic connection is enabled when the valves <NUM>, <NUM>, <NUM> (nv) are in an open position, while the hydraulic connection of the main tank <NUM> is always enabled.

Each valve <NUM>, <NUM>, <NUM>, (nv) is therefore configured for selectively enabling a flow of auxiliary operating liquid in the hydraulic connection between the corresponding auxiliary tank and the manifold <NUM>, in such a way as to mix the main operating liquid, coming from tank <NUM>, and a corresponding - selected - auxiliary operating liquid, thus defining an operating mixture of the system. It must be kept in mind, moreover, that in certain embodiments, depending on the nature of the main and auxiliary operating liquids, the operating mixture may comprise the main operating liquid and two or more auxiliary operating liquids. Unlike the supply unit <NUM>, the pump of the supply unit <NUM> is configured for drawing the operating mixture from manifold <NUM> through inlet port <NUM>, and for selecting the delivery port <NUM>, <NUM> or <NUM> which will deliver the drawn operating mixture to the dispensing unit <NUM>.

The basic operation of system <NUM> is identical to system <NUM>; however, system <NUM> implements further functions described in the following.

Thanks to the mixing unit <NUM> it is possible to define a specific operating mixture for each single user of the dispensing unit <NUM>.

The operating mixture for injectors <NUM>, <NUM> may be defined according to the procedure described in the foregoing, i.e. by mixing the windscreen washer liquid stored in tank <NUM> with a defoaming agent stored in tank <NUM>. Unlike system <NUM>, in system <NUM> the pump of the supply unit <NUM> may be small sized (i.e. may have a reduced flow rate), because the latter pump may implement pressure conditions similar to those of system <NUM> by loading accumulators <NUM> and <NUM> (flow F140 through the delivery port <NUM>), while offering the additional advantage, i. , of a more rapid action of the system, thanks to the vicinity of the accumulators to the injectors <NUM>, <NUM>.

The operating mixture for the set of windscreen washer nozzles <NUM> may be defined by only drawing windscreen washer liquid from tank <NUM> and by delivering it through port <NUM> (flow F150), while the operating mixture for the set of sensor washing nozzles <NUM> may be obtained by mixing the windscreen washer liquid stored in tank <NUM> with the sensor washing liquid stored in tank <NUM>. It will be observed, moreover, that thanks to the features of system <NUM> it is possible to fill tank <NUM> simply with water (with the optional addition of an anti-freezing agent), and to assign to each of the tanks <NUM>, <NUM>, <NUM> an auxiliary operating liquid corresponding to the agent required by the various users of the dispensing unit <NUM>: defoaming agent (injectors <NUM>, <NUM> of system <NUM>), windscreen washer liquid (set <NUM>) and sensor washing liquid (set <NUM>). In this case, it is moreover possible to replace the defoaming agent with a cleaning agent, in order to keep the injectors clean.

The person skilled in the art will therefore appreciate that the systems <NUM>, <NUM> make it possible to combine, with a normal on-board equipment for windscreen washing, an on-demand mixing equipment for adding additives or agents required for performing various different functions, without the need of modifying the normal container of windscreen washer fluid (tank <NUM>, <NUM>). The mixing units <NUM>, <NUM> provide the operating mixture with user-based logic and on demand, therefore making systems <NUM>, <NUM> extremely flexible and effective. As regards the operation of injectors <NUM>, <NUM> or <NUM>, <NUM> only, the systems <NUM>, <NUM> completely eliminate the onset of foam during injection, thanks to the possibility of adding a defoaming agent, further flexibility being provided by the possibility of separately mixing water, in order to dilute the windscreen washer liquid used as the main operating liquid and, for system <NUM>, with the further possibility of improving the intervention dynamics of the system, thanks to the constant availability of pressurized liquid directly upstream injectors <NUM>, <NUM> ensured by accumulators <NUM>, <NUM>.

Finally, referring to <FIG>, in preferred embodiments of system <NUM> and system <NUM> the mixing unit <NUM>, <NUM> includes, for each hydraulic connection between the auxiliary tanks <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, a Venturi effect flow element V16, V116, V18, V118, V20, V120 (at least roughly resembling a carburettor jet) hydraulically arranged upstream the electrically operated valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>). In a comparison with the embodiments of systems <NUM>, <NUM> of <FIG>, <FIG>, the provision of the Venturi effect flow elements enables an accurate adjustment (e.g. by choosing the inner diameter of flow elements V16, V116, V18, V118, V20, V120) of the amount of auxiliary liquid which is to be mixed with the main liquid by the mixing unit, similarly (but with only partially analogous processes) to the case of mixing air and fuel in a carburettor. The view in <FIG> exemplifies embodiments which envisage the presence of more than one auxiliary tank, while <FIG> exemplifies embodiments - which are preferable in certain applications - having only one auxiliary tank <NUM>, <NUM>.

In an embodiment of system <NUM>, the structure of <FIG> may envisage the tank <NUM> storing a windscreen washer liquid as auxiliary fluid, which is mixed with the main liquid (water) only when the flow F_IN does not need to be delivered to injectors <NUM>, <NUM>, i.e. only when it is necessary to mix water and windscreen washer liquid for cleaning the windscreen or the rear window. Conversely, the mixing of the windscreen washer liquid with the water in the main tank <NUM> is inhibited when it is necessary to deliver the flow F_IN to the injectors <NUM>, <NUM>.

Claim 1:
An anti-aquaplaning system (<NUM>; <NUM>) for a motor vehicle, including:
- a storage unit (<NUM>; <NUM>) for operating liquids,
- a mixing unit (<NUM>; <NUM>),
- a supply unit (<NUM>; <NUM>),
- a dispensing unit (<NUM>; <NUM>), said dispensing unit (<NUM>; <NUM>) comprising at least a first injector and a second injector (<NUM>, <NUM>; <NUM>, <NUM>) configured for injection of liquid to the ground in at the front of, respectively, a right tread (RT) and a left tread (LT) of a right wheel (R) and a left wheel (L) of a motor vehicle axle, respectively,
wherein:
- said storage unit (<NUM>; <NUM>) includes a main tank (<NUM>; <NUM>) configured for storing a main operating liquid, and at least one auxiliary tank (<NUM>, <NUM>; <NUM>; <NUM>, <NUM>, <NUM>) configured for storing a corresponding auxiliary operating liquid, each of said main tank (<NUM>; <NUM>) and at least one auxiliary tank (<NUM>, <NUM>; <NUM>; <NUM>, <NUM>, <NUM>) having a hydraulic connection (<NUM>; <NUM>, <NUM>, <NUM>,<NUM>; <NUM>; <NUM>, <NUM>, <NUM>, <NUM>) to said supply unit (<NUM>; <NUM>),
- said mixing unit (<NUM>) is configured to mix a predetermined amount of said main operating liquid with a predetermined amount of at least one of said auxiliary operating liquids, thereby defining an operating mixture of the system,
this supply unit (<NUM>; <NUM>) is configured to deliver said operating mixture to said first injector and second injector (<NUM>, <NUM>; <NUM>, <NUM>).