FR3045514A1 - TANK INTEGRATING BUFFER RESERVE TO AVOID OVERFLOW DURING FILLING - Google Patents

Abstract

The invention relates primarily to an assembly (10) for a motor vehicle comprising: - a reservoir (12), - a pipe for filling with a liquid, said pipe opening inside said tank (12), - a degassing pipe (20) opening into said reservoir (12), and - a filling height management volume (16) for limiting a volume of filling liquid inside said reservoir (12), characterized in that said assembly (10) further includes a buffer reservoir (25) in said fill height management volume (16), said buffer reservoir (25) being in fluid communication with said vent pipe (20) via a first port ( 27) and in fluid communication with an internal volume of said reservoir (12) via a second orifice (28) calibrated to allow a passage of liquid at a speed less than a filling rate of said reservoir (12).

Description

TANK INCORPORATING A BUFFER RESERVE TO AVOID OVERFLOW DURING FILLING

The present invention relates to a tank incorporating a buffer reserve to prevent overflow during a filling. The invention finds a particularly advantageous, but not exclusive, application in the field of motor vehicles.

[0002] Motor vehicles include several types of tanks intended to contain a liquid useful for the proper functioning of the vehicle. Examples include the fuel tank for storing the fuel before being injected into the engine, the oil and windshield containing fuel tanks, but also the tanks containing an additive, such as the urea, allowing the treatment of exhaust gases.

In a manner known per se, these tanks are filled so as to reach a high limit. Exceeding this high limit may cause the liquid to come out of the tank, either outside the vehicle in the case of fuel tanks or inside the vehicle in the case of urea tanks accessible from the trunk. . In the case of harmful or dangerous liquids, such as fuel or urea, the discharge can cause material damage related for example to the corrosion of elements of the vehicle, or health damage, such as irritations caused by toxicity. liquids.

To limit the risk of backflow during filling, it is necessary to evacuate the air in the tank to replace it with the corresponding liquid. For this purpose, it is known to use a separate degassing circuit of the filling circuit to evacuate the air without interfering with the introduction of the liquid into the reservoir. The degassing circuit comprises a pipe commonly placed in an upper part of the tank, and more frequently on an upper wall of the tank, to allow easy evacuation of the air overhanging the liquid.

However, these degassing systems have the disadvantage of being filled with filling liquid when the degassing valve is blocked or when the tank is too full. Cala then involves modifying the degassing pipe by incorporating an air tank to prevent overflow of the liquid during filling. This tank addition complicates pipe manufacture and increases its cost of manufacture. In addition, the backflow phenomenon of the liquid worsens when the contents of the tank undergoes expansion, due in particular to an increase in temperature.

The invention aims to overcome these disadvantages by providing a set for a motor vehicle comprising: - a tank, - a filling pipe with a liquid, the pipe opening into the tank, - a degassing pipe opening inside the tank, and - a filling height management volume to limit a volume of filling liquid inside the tank, characterized in that the assembly further comprises a buffer reservoir located in the volume of fill height management, the buffer reservoir being in fluid communication with the vent pipe via a first port and in fluid communication with an internal volume of the tank via a second calibrated orifice to allow a passage of liquid at a speed below a speed filling the tank.

The invention thus makes it possible to overcome the constraints associated with the modification of the degassing pipe by proposing an integrated buffer reserve inside the tank which makes it possible to generate a pressure peak which will cause the shutdown of a filling gun. The invention thus has the advantage of not requiring additional installation in the factory, nor having to make a tight connection.

In one embodiment, the degassing pipe is connected to the filler pipe.

In one embodiment, the second orifice is formed in a lower wall of the buffer pool.

In one embodiment, the second orifice is formed in a side wall of the buffer pool.

According to one embodiment, the buffer pool comprises a third orifice made in the lower wall and having a diameter smaller than the diameter of the first orifice and the second orifice of the buffer pool.

In one embodiment, the buffer pool is constituted by a housing portion inserted into the filling height management volume.

In one embodiment, the buffer pool is delimited by a closure plate at least partially closing the filling height management volume.

In one embodiment, the buffer pool is equipped with a snap fastening means.

According to one embodiment, the buffer pool comprises a gripping member for mounting.

The invention will be better understood on reading the description which follows and the examination of the figures that accompany it. These figures are given for illustrative but not limiting of the invention.

Figure 1 is a perspective view of a motor vehicle tank without the buffer pool according to the present invention; Figure 2 is a perspective view of a buffer pool according to the present invention; Figure 3 is a sectional view of a motor vehicle tank incorporating the buffer reservoir of Figure 2 according to the present invention; Figure 4 is a sectional view of an alternative embodiment of the buffer pool according to the present invention; Figures 5a to 5c are schematic sectional views illustrating the steps of filling a reservoir with a buffer reservoir according to the present invention; Figures 6, 7a and 7b are views illustrating alternative embodiments of elements for obtaining a buffer pool according to the present invention.

Identical elements, similar, or the like retain the same reference from one figure to another.

Figures 3 and 4 show an assembly 10 for a motor vehicle comprising a reservoir 12 containing for example an additive for the treatment of exhaust gas. This additive can be a precursor of ammonia, such as urea in the aqueous phase. Urea is injected into the exhaust line so that the urea thermally decomposes to ammonia, which then reduces the NOx contained in the exhaust gas in a catalyst disposed downstream of the injection point of the reactor. urea on the exhaust line.

Alternatively, the reservoir 12 may contain other types of additive, for the treatment of exhaust gas or for other functions, or it may contain fuel.

The tank 12 comprises in particular an upper wall 13, a bottom wall 14 and a side wall 15. The relative meaning of the terms "high" or "low" is understood with respect to the orientation of a tank 12 assembled and mounted in the vehicle as visible for example in Figures 3 or 4. The reservoir 12 may be obtained for example by assembling a lower portion 121 and an upper portion 122. The assembly may be performed by bonding, riveting, or welding along a peripheral lip 123 surrounding the side wall 15.

The reservoir 12 is in fluid communication with a filling pipe 18 opening into the interior of the tank 12 through the side wall 15 via a through opening 19. In addition, a degassing pipe 20 is connected to a bypass filling pipe 18 and opens inside the tank 12 through the side wall 15 via a through opening 23. The degassing pipe 20 thus allows the evacuation of the air contained in the reservoir 12 during filling.

As illustrated in Figure 1, a partition 24 projecting from the upper wall 13 inwardly of the tank 12 allows, in association with the side wall 15, to define a volume 16 of filling height management so to limit a volume of filling liquid inside the tank 12. For this purpose, the partition 24 extends beyond the opening 19. Due to the creation of this volume 16, the liquid does not exceed the lower part of the partition 24 or, if appropriate, the upper part of notches designed to adapt the height of the liquid (see reference 37 in FIG. 1), but may fill the filling height management volume 16 up to the opening 23.

According to the invention, a buffer reserve 25 formed for example by a housing shown in Figure 2, is located in the volume 16 so as to prevent the discharge of the filling liquid from the tank 12. In this case , the buffer reserve 25 is kept jammed between the partition 24 and the side wall 15.

As shown in Figure 3, the buffer reservoir 25 is provided with an orifice 27 in fluid communication with the degassing pipe 20 and a second orifice 28 in communication with the internal volume of the reservoir 12 corresponding to the volume capable of being filled with liquid except for volume 16.

The orifice 28 is calibrated to allow a passage of liquid inside the buffer reserve 25 at a lower speed than the filling rate of the reservoir 12. For example, for a filling of the reservoir 12 via the pipe 18 of the order of 40 L / min, the filling of the buffer reserve 25 via the orifice 28 will be between 10 L / min and 20 L / min. Preferably, the buffer reserve 25 has an internal volume of between 0.2 liter and 0.4 liter.

In the embodiment of Figure 3, the orifice 28 is formed in a lower wall 21 of the buffer pool 25. However, alternatively, the orifice 28 may be formed in a side wall 22 of the reserve buffer 25, as shown in FIG. 4. The buffer reservoir 25 then has a third orifice 32 made in the bottom wall 21. The orifice 32 has in this case a diameter smaller than the diameter of the orifice 28 and the orifice 27. The orifice 32 allows the buffer reservoir 25 and the reservoir 12 to empty at the same rate during use of the vehicle.

5a to 5c, a filling phase of the reservoir 12 provided with the buffer reservoir 25. More specifically, as illustrated by FIG. 5a, during the filling of the reservoir 12, the liquid flow from the pipe 18 can reach 40 L / min. The air contained inside the tank 12 then escapes at the same speed through the degassing pipe 20.

As illustrated in Figure 5b, the reservoir 12 fills up to the orifice 28 of the buffer pool 25, then the buffer 25 is filled in turn. The liquid column runs parallel to the filling pipe 18 and triggers the stopping of the filling gun 36 due to the generation of a pressure peak. It is noted that the loss of pressure caused by the filling time of the buffer reserve 25 has made it possible to prevent the liquid from reaching the upper end of the degassing pipe 20.

As illustrated in FIG. 5c, after stopping the gun 36, the liquid levels are equilibrated in the pipes 18 and 20 at a height less than the top of the pipes 18 and 20. There is therefore no overflow at the end of filling.

Alternatively, as shown in Figure 7a, the buffer pool 25 is delimited by a closure plate 31 at least partially closing the volume 16. The plate 31 is provided with the orifice 28. To ensure its guide inside the reservoir 12, the plate 31 preferably comprises a plurality of elongate tabs 34. A snap-fastening means 33 makes it possible to fix the plate 31 to the reservoir 12. This fixing means 33 is constituted for example by a form of hook coming from a free end of one of the tabs 34 intended to cooperate by elastic deformation with a rim of the opening 23 opening towards the pipe 20, as shown in FIG.

In another alternative embodiment shown in FIG. 7b, the buffer reserve 25 is constituted by a housing portion 30 inserted into the volume 16. The housing portion 30 may be provided with a fixing means by detent 33 constituted for example by a tab provided with a hook for cooperating by elastic deformation with a flange of the opening 23, as shown in Figure 6.

In addition, to facilitate their mounting inside the tank 12, the plate 31 or the housing portion 30 each comprises a gripping member 29 that the user can easily grasp when setting up the element 30, 31 in volume 16.

Claims (9)

An assembly (10) for a motor vehicle comprising: - a reservoir (12), - a filling pipe (18) with a liquid, said pipe (18) opening into said reservoir (12), - a pipe of degassing (20) opening into said reservoir (12), and - a filling height management volume (16) for limiting a volume of filling liquid inside said reservoir (12), characterized in that said assembly (10) further comprises a buffer reservoir (25) located in said fill height management volume (16), said buffer reserve (25) being in fluid communication with said degassing pipe (20) via a first orifice (27) and in fluid communication with an internal volume of said reservoir (12) via a second orifice (28) calibrated to allow a passage of liquid at a rate lower than a filling rate of said reservoir (12). 2. The assembly of claim 1, characterized in that said degassing pipe (20) is connected to said filler pipe (18). 3. The assembly of claim 1 or 2, characterized in that said second orifice (28) is formed in a bottom wall (21) of said buffer pool (25). 4. The assembly of claim 1 or 2, characterized in that said second orifice (28) is formed in a side wall (22) of said buffer pool (25). 5. The assembly of claim 4, characterized in that said buffer pool (25) comprises a third orifice (32) formed in said bottom wall (21) and having a diameter smaller than the diameter of said first orifice (27) and said second orifice. (28) of said buffer pool (25). 6. An assembly according to any one of claims 1 to 5, characterized in that said buffer reserve (25) is constituted by a housing portion (30) inserted into said filling height management volume (16). 7. An assembly according to any one of claims 1 to 5, characterized in that said buffer pool (25) is delimited by a closure plate (31) at least partially closing said filling height management volume (16). 8. An assembly according to any one of claims 1 to 7, characterized in that said buffer pool (25) is equipped with a fastening means (33) snap. 9. An assembly according to any one of claims 1 to 8, characterized in that said buffer reserve (25) comprises a gripping member (29) for mounting.