VALVE FOR A SPRAY SYSTEM

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of cleaning liquid projection systems for motor vehicles and in particular to the valves used in these systems. PRIOR TECHNIQUE

[0002] All motor vehicles have a cleaning fluid projection system to keep the vehicle's windshield clean and allow the driver to have optimal outward vision. Other optical devices, such as sensors, may also require such projection systems.

[0003] These systems generally include a cleaning fluid reservoir, a pump and at least one valve configured to allow or block the passage of cleaning fluid to the various spray tips or nozzles.

[0004] One of the problems with hydraulic valves placed in the hydraulic circuit of spray systems is the risk of valve malfunction due to valve icing. In addition, in very low temperatures, the cleaning fluid present in the valve can freeze, which can then lead to damage to the valve due to the expansion of the water when it freezes, causing a failure of the cleaning fluid spray system.

[0005] In order to avoid such damage to the valves in the event of frost, it is therefore necessary to find a solution to protect the electromagnetic valves in the cleaning fluid spray systems of motor vehicles in the event of frost.

[0006] A system for projecting a cleaning liquid as known in the state of the art is disclosed in document WO 2018 / 188823 A1. SUMMARY OF THE INVENTION

[0007] For this purpose, a cleaning liquid projection system is proposed comprising a liquid reservoir, a pump, at least one cleaning liquid projection nozzle and at least one valve, said valve comprising: a valve body enclosing a hydraulic cavity configured to be fluidically connected to a hydraulic channel of the projection system and intended to receive the cleaning liquid, a plunger configured to be moved in the hydraulic cavity between an open position in which it allows the cleaning liquid to pass into the hydraulic channel and a closed position in which it blocks the passage of the cleaning liquid through the hydraulic channel, the valve also comprising a compressible elastic element enclosing a gas disposed in the hydraulic cavity and configured to be compressed in the event of the cleaning liquid freezing in the valve.

[0008] According to one embodiment, the compressible elastic element containing a gas is a closed-cell foam.

[0009] the closed-cell foam is made of ethylene-propylene-diene-monomer “EPDM”. According to one embodiment, the volume of foam corresponds to at least 10% of the volume of the hydraulic cavity, in particular 10% of the volume of the hydraulic cavity.

[0010] According to one embodiment, the valve is an electromagnetic valve also comprising: a coil (13) configured to move the plunger (7) from the closed position to the open position.

[0011] According to one embodiment, the hydraulic cavity comprises a first portion surrounded by the coil and a second portion distinct from the first portion and in which the compressible elastic element containing a gas is arranged in the second portion of the hydraulic cavity.

[0012] According to one embodiment, the compressible elastic element containing the gas is fixed to the plunger.

[0013] According to one embodiment, the plunger comprises a first portion configured to come into contact with the valve body in the closed position and in which the compressible elastic element containing the gas is fixed to the plunger at a second portion distinct from the first portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Other characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and non-limiting example and the appended drawings among which: [ Fig.1 ] represents a schematic representation of a cleaning liquid projection system according to an embodiment of the present invention. [ Fig.2 ] represents a schematic sectional view of a solenoid valve in the closed state according to an embodiment of the present invention; [ Fig.3 ] represents a schematic perspective view of a solenoid valve; [ Fig.4 ] represents a schematic sectional view of a solenoid valve in the open state according to an embodiment of the present invention;

[0015] In these figures, identical elements have the same references. DETAILED DESCRIPTION

[0016] The following embodiments 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 apply only to a single embodiment. Single features of different embodiments may also be combined or interchanged to provide other embodiments, as long as they fall within the scope of the claims.

[0017] Implementations and embodiments of the invention relate to a liquid projection system.

[0018] There figure 1 represents an exemplary embodiment of a projection system 20 comprising a liquid reservoir 22, a pump 24, three projection nozzles 26 of cleaning liquid configured for example to spray a cleaning liquid on the windshield or on optical elements of a motor vehicle. The projection system 20 also comprises three valves 1 for controlling the distribution of the cleaning liquid to the projection nozzles 26. The valves 1 are connected to the reservoir 22 by supply hoses 28 and the projection nozzles 26 are connected to the valves 1 by distribution hoses 30.

[0019] The valves 1 are, for example, electromagnetic valves comprising a coil whose power supply makes it possible to control the movement of a plunger like that described in the remainder of the description. However, the invention is not limited to electromagnetic valves and can also be applied to other types of valves.

[0020] There figure 2 represents a sectional view of the electromagnetic valve 1 showing the internal elements of the electromagnetic valve 1 and the figure 3 represents a perspective view of an electromagnetic valve 1. The electromagnetic valve 1 is configured to be arranged in a system 20 for projecting a cleaning liquid as shown in the figure 1 .

[0021] The electromagnetic valve 1 comprises a valve body 3 enclosing a hydraulic cavity 5 in which a plunger 7 is positioned. The valve body 3 comprises a first part 3a comprising a coil 13 arranged around a first portion 5a of the hydraulic cavity 5 and a second part 3b in which a first orifice 9 corresponding to a fluid inlet orifice and a second orifice 11 corresponding to a fluid outlet orifice and enclosing a second portion 5b of the hydraulic cavity 5 are provided. The first orifice 9 is configured to be connected to a supply hose 28 for the fluid, for example a cleaning or washing liquid. The supply hose 28 is for example connected to a cleaning liquid reservoir 22 via a supply pump 24 allowing the cleaning liquid to be supplied.

[0022] The second port 11 is configured to be connected to a projection nozzle 26 via a distribution hose 30.

[0023] The electromagnetic valve 1 also comprises a hydraulic channel 15 connecting the first orifice 9 and the second orifice 11, said hydraulic channel 15 being in fluidic relation with the hydraulic cavity 5 in which the plunger 7 is arranged (the hydraulic channel 15 is therefore locally merged with the second portion 5b of the hydraulic cavity 5). The hydraulic channel 15 is configured to be extended on either side of the electromagnetic valve 1, in particular via the hoses 28, 30, so as to transmit the cleaning liquid from the reservoir 22 to a projection nozzle 26.

[0024] The plunger 7 is configured to move between an open position (shown in the figure 4 ) in which it allows the cleaning liquid to pass between the supply hose 28 and the distribution hose 30 and a closed position (shown on the figure 2 ) in which it blocks the passage of the cleaning liquid between the supply hose 28 and the distribution hose 30.

[0025] The plunger 7 comprises a first portion 7a, corresponding to a flexible end in the present case, for example an elastomer or rubber end to allow good sealing in the closed position, the first portion 7a coming into contact with a wall of the valve body 3 in the closed position to block the passage of the cleaning liquid through the hydraulic channel 15, that is to say between the first orifice 9 and the second orifice 11. The movement of the plunger 7 from the closed position to the open position is carried out via the power supply of the coil 13 (for example above a predetermined voltage threshold).An elastic constraint element 17, for example a helical spring, may be arranged between the valve body 3 (or an element fixed relative to the valve body 3) and the plunger 7 and configured to constrain the plunger 7 to the closed position in the absence of power to the coil 13 (or in the event of power being lower than the predetermined voltage threshold).

[0026] Furthermore, to prevent damage to the valve body 3 when the cleaning liquid inside the hydraulic cavity 5 freezes, for example when outside temperatures are below 0°C, the electromagnetic valve 1 also comprises a compressible elastic element 19 containing a gas, for example air, and arranged in the hydraulic cavity 5. This compressible elastic element 19 is for example a closed-cell foam and acts as a compressible cushion.

[0027] The compressible elastic element 19 is for example fixed to the wall of the hydraulic cavity 5 or to the plunger 7. The fixing of the compressible elastic element 19 is for example carried out by gluing. The compressible elastic element 19 occupies for example at least 10% of the volume of the hydraulic cavity 5 (when it is not compressed) which corresponds to the additional volume taken up by the ice compared to the water. This volume can also be equal to 10% of the volume of the cavity or even slightly less depending on the cleaning liquid used.

[0028] In the case of an electromagnetic valve 1, the compressible elastic element 19 is preferably located at a distance from the coil 13, that is to say outside the first portion 5a of the hydraulic cavity 5 surrounded by the coil 13 so as to avoid any disturbance of the electromagnetic operation of the valve 1.

[0029] The compressible elastic element 19 is preferably positioned at a distance from the interface zones between parts that move relative to each other to avoid any deterioration of the compressible elastic element 19 by mechanical friction due to contact with the different parts. When the compressible elastic element is fixed to the plunger 7, the compressible elastic element 19 is, for example, fixed to a second portion distinct from the first portion 7a and in particular at a distance from the part of the first portion 7a coming into contact with a wall of the valve body 3.

[0030] The closed-cell foam of the compressible elastic element 19 is, for example, made of ethylene-propylene-diene-monomer, more commonly called EPDM.

[0031] Thus, in the event of the cleaning liquid freezing in the valve body 3, the ice primarily compresses the compressible elastic element 19 which is more flexible than the walls of the valve body 3 or the plunger 7, thereby protecting the latter.

[0032] The present invention also relates to a system 20 for projecting a cleaning liquid comprising a liquid reservoir 22, a pump 24, at least one cleaning liquid projection nozzle 26 and at least one valve 1 as described previously.

Claims

1. System for spraying a cleaning liquid (20), comprising a liquid reservoir (22), a pump (24), at least one endpiece for spraying cleaning liquid (26), and at least one valve (1), said system being characterized in that said valve (1) comprises: - a valve body (3) including a hydraulic cavity (5) configured to be fluidically connected to a hydraulic channel (15) of the spray system and intended to receive the cleaning liquid, - a plunger (7) configured to be displaced in the hydraulic cavity (5) between an open position, in which it allows the cleaning liquid to enter the hydraulic channel (15), and a closed position, in which it prevents the cleaning liquid from passing through the hydraulic channel (15), and in that the valve (1) also comprises a compressible elastic element (19) containing a gas disposed in the hydraulic cavity (5) and configured to be compressed if the cleaning liquid in the valve (1) freezes.

2. System (20) according to Claim 1, wherein the compressible elastic element (19) containing a gas is a closed-cell foam.

3. System (20) according to Claim 1 or 2, wherein the closed-cell foam is made from ethylene-propylene-diene monomer "EPDM".

4. System (20) according to one of the preceding claims, wherein the volume of foam corresponds to at least 10% of the volume of the hydraulic cavity (5), in particular 10% of the volume of the hydraulic cavity (5).

5. System (20) according to Claim 1, which is an electromagnetic valve also comprising: - a coil (13) configured to displace the plunger (7) from the closed position to the open position.

6. System (20) according to Claim 5, wherein the hydraulic cavity (5) comprises a first portion (5a), surrounded by the coil (13), and a second portion (5b) separate from the first portion (5a), and wherein the compressible elastic element (19) containing a gas is disposed in the second portion (5b) of the hydraulic cavity (5).

7. System (20) according to one of the preceding claims, wherein the compressible elastic element (19) containing the gas is fixed on the plunger (7).

8. System (20) according to the preceding claim, wherein the plunger (7) comprises a first portion (7a) configured to come into contact with the valve body (3) in the closed position, and wherein the compressible elastic element (19) containing the gas is fixed on the plunger (7) at a second portion separate from the first portion (7a).