A fuel vapor emission management system for a motor vehicle, comprising a fuel tank connected to a vapor recovery unit and means for disconnecting the unit and the tank in the event of a collision

Abstract

This fuel vapor management system for a motor vehicle includes a fuel tank and a fuel vapor recovery unit (3) connected by a filler neck (4). The management system includes means (9) for disconnecting the unit (3) and the tank, comprising a plate (10) disposed between the tank and the unit (3), having greater stiffness than the unit (3), and extending vertically from a support (11) of the vehicle to the filler neck (4), the plate (10) extending beyond an outer edge (4a) of the filler neck (4). Figure 3

Description

Title of the invention: Fuel vapor emission management system for a motor vehicle comprising a fuel tank connected to a vapor recovery unit and means for disconnecting the unit and the tank in the event of a collision. Technical field

[0001] The invention relates to the field of fuel vapor emission management systems for motor vehicles, in particular systems equipped with a fuel vapor suction tank. Previous techniques

[0002] On a motor vehicle equipped with an internal combustion engine, more particularly a spark-ignition (gasoline) engine, the fuel vapor recovery unit, known to those skilled in the art by its English name "canister", includes a charcoal filter and is configured to collect fuel vapors escaping from the tank through a filler pipe.

[0003] Conventionally, the filling pipe is equipped with a non-return valve located upstream of the canister.

[0004] During a significant impact on the vehicle, it is possible that the canister may be crushed and that particles of coal may pass from the canister to the non-return valve through the filling pipe.

[0005] There is then a risk of clogging of the non-return valve which can endanger the safety of passengers, for example by increasing the risk of fuel leakage and fire. Description of the invention

[0006] The invention aims to prevent the transit of coal particles from the canister to the non-return valve, in the event of a crushing of the canister caused by a vehicle impact.

[0007] The invention relates to a fuel vapor emission management system for a motor vehicle comprising a fuel tank and a fuel vapor recovery unit connected by a filling pipe.

[0008] The management system includes means for disconnecting the housing and the tank comprising a sheet metal arranged between the tank and the housing, the sheet metal having a greater rigidity than that of the housing, and extending vertically from a support of the vehicle towards the filling pipe, the sheet metal extending beyond an outer edge of the filling pipe.

[0009] Advantageously, during a vehicle impact that displaces the housing towards the sheet metal, the filler pipe strikes a vertical edge of the sheet metal, creating a shear force on the filler pipe that reaches a predetermined shear threshold value, representing a disconnection of the housing and the tank. Such a configuration allows for automatic disconnection of the housing and the tank in the event of a vehicle impact.

[0010] According to one feature, the sheet metal is provided with rounded edges. Such sheet metal ensures the safety of assembly and maintenance operations by protecting the physical integrity of operators against the risk of cuts.

[0011] For example, the sheet metal includes a stamped area or stiffeners on one side face. Such a configuration makes it possible to increase the stiffness of the sheet metal.

[0012] Preferably, the sheet metal is metallic. Metallic sheet metal allows for easy, inexpensive and controlled manufacturing.

[0013] For example, the sheet metal is welded to the vehicle support.

[0014] For example, the sheet metal is provided with at least one fixing tab intended to fix the sheet metal to the vehicle support.

[0015] Advantageously, the sheet metal is located at a predetermined minimum safety distance from a bleed pipe connecting the housing to an intake circuit of a vehicle engine. Such a configuration ensures that the bleed pipe does not come into contact with the sheet metal.

[0016] For example, the impact is a rear impact of the vehicle.

[0017] According to another aspect, the invention relates to a motor vehicle comprising a fuel vapor emission management system as described above. Brief description of the drawings

[0018] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0019] [Fig-1] illustrates a direct orthonormal XYZ coordinate system classically used in automotive design;

[0020] [Fig.2] is a partial view from below of a rear portion of a motor vehicle comprising a fuel vapor emission management system according to an embodiment of the invention; and

[0021] [Fig.3] a perspective view of a disconnection device for the management system of the [Fig.2]. Detailed description of at least one embodiment

[0022] For the purposes of this description, reference will be made to a direct orthonormal coordinate system XYZ, classically used in automotive design and illustrated in [Fig. 1]. In this coordinate system, the X-axis designates the front-to-rear longitudinal direction of the vehicle, oriented Towards the rear, the Y axis designates the transverse direction and is oriented towards the right of the vehicle, the Z axis designates the vertical direction, and is oriented upwards.

[0023] Figure 2 is a partial view from below of a rear portion of a motor vehicle comprising a fuel vapor management system 1 according to an embodiment of the invention. The management system 1 comprises a fuel tank 2 and a fuel vapor recovery unit or canister 3.

[0024] In the illustrated embodiment, the canister 3 is positioned at the rear of the tank 2.

[0025] The canister 3 is connected to the tank 2 to recover fuel vapors from the tank 2 through a filling pipe 4 fitted with a non-return valve (not referenced).

[0026] The canister 3 is connected to the vehicle's engine intake by a purge pipe 5 equipped with a purge valve (not referenced) whose opening controls the passage of fuel vapors to the engine intake.

[0027] The tank 2 is protected against a rear impact by a rigid crossmember 6 of the rear part of the vehicle which is substantially parallel to the transverse axis Y and disposed at the rear and in the immediate vicinity of the tank 2.

[0028] The rear part further includes a bumper 7 located at the rear end of the vehicle, and a spare wheel 8 interposed between the canister 3 and the bumper 7.

[0029] During a significant rear impact, the bumper 7 deforms and presses against the spare wheel 8, which in turn presses against the canister 3 until it is crushed.

[0030] Crushing the canister 3 presents the safety risk related to the release of coal particles and the clogging of the non-return valve described previously.

[0031] In order to prevent the transit of coal particles from the canister 3 to the non-return valve during a significant rear impact, the fuel vapor emission management system 1 is equipped with a disconnection device 9 for the canister 3 and the tank 2.

[0032] Fig. 3 is a perspective view of the disconnection device 9 of Fig. 2.

[0033] The disconnection device 9 comprises a plate 10 disposed between the reservoir 2 and The canister 3 is fixed to at least one support 11 of the vehicle. The support 11 may be a crossmember, a side member, or a sheet metal part. The sheet metal 10 is fixed to the support 11, in particular, by spot welds or weld beads, and / or by fastening means such as screws or bolts.

[0034] To facilitate fixing, the sheet metal 10 is preferably provided with at least one fixing tab 12 which is in contact with the support 11. Here, the fixing tab 12 is parallel to a surface 1la of the support 11. The fixing tab can be made by cutting and bending the sheet metal 10.

[0035] The sheet metal 10 extends vertically from the support 11 towards the filling pipe 4, up to a level Z0 located below an outside diameter D4 of the filling pipe 4. In other words, the sheet metal 10 extends beyond an outside edge 4a of the filling pipe 4. Here, the level Z0 is above an outside diameter D5 of the purge pipe 5.

[0036] Preferably, the level Z0 of the sheet metal 10 is located at a predetermined minimum safety distance from the purge pipe 5. Alternatively, it remains possible that the level Z0 is below the outside diameter D5 of the purge pipe 5, i.e. that the sheet metal 10 protrudes beyond an outside edge of the purge pipe.

[0037] The sheet metal 10 has a greater front-to-back longitudinal stiffness than that of the canister 3, so that when they are subjected to similar forces oriented along the X axis, the resulting displacement of the sheet metal 10 is less than the resulting displacement of the canister 3.

[0038] Thus, during a significant rear-end collision, the filler pipe 4 strikes a vertical edge 13 of the plate 10, creating a shear force on the pipe 4. The energy of such an impact is dissipated primarily by the deformation of the rear of the vehicle. The difference between the forward displacements of the canister 3 and the plate 10 increases with this deformation, resulting in a growing shear force on the filler pipe 4, reaching a predetermined shear threshold value that disconnects the filler pipe 4 from the canister 3. The disconnection of the filler pipe 4 from the canister 3 can occur, in particular, through rupture of the filler pipe 4 or by the filler pipe 4 being torn away from the canister 3. The predetermined shear threshold value thus represents the disconnection of the canister 3 and the tank 2.

[0039] To increase the stiffness of the sheet metal 10, reinforcements such as stiffeners or stamped areas can be provided on at least one lateral face 14 of the sheet metal 10. Here, the sheet metal 10 is reinforced by a central stamped area 15. Alternatively, vertical stiffeners of the rib or fin type can be provided on the lateral face 14.

[0040] Preferably, the side face 14 is formed by stamping, so as to create edges 16 substantially perpendicular to the side face 14. Advantageously, the sheet 10 is provided with rounded edges 17.

[0041] Preferably, the sheet 10 is metallic.

[0042] As previously stated, in the illustrated embodiment, the canister 3 is positioned at the rear of the tank 2. Alternatively, different configurations are possible. For example, the canister 3 can be positioned longitudinally in front of the tank 2 and transversely outside the tank 2.

Claims

Demands

1. A fuel vapor management system (1) for a motor vehicle comprising a fuel tank (2) and a fuel vapor recovery unit (3) connected by a filler pipe (4), characterized in that said management system comprises means for disconnecting the unit (3) and the tank (2) comprising a plate (10) disposed between the tank (2) and the unit (3), the plate (10) having a greater stiffness than the unit (3), and extending vertically from a support (11) of the vehicle to the filler pipe (4), said plate (10) extending beyond an outer edge (4a) of the filler pipe (4).

2. Management system according to claim 1, wherein during a collision of the vehicle moving the housing (3) towards the sheet metal (10), the filling pipe (4) butts against a vertical edge (13) of the sheet metal (10), so as to create a shear force of the filling pipe (4) reaching a predetermined shear threshold value, representative of a disconnection of the housing (3) and the tank (2).

3. Management system according to claim 1 or 2, wherein the sheet metal (10) is provided with rounded stops (17).

4. Management system according to any one of claims 1 to 3, wherein the sheet metal (10) comprises on a lateral face (14) a stamped area (15) or stiffeners.

5. Management system according to any one of claims 1 to 4, wherein the sheet metal (10) is metallic.

6. Management system according to any one of claims 1 to 5, wherein the sheet metal (10) is welded to the support (11) of the vehicle.

7. Management system according to any one of claims 1 to 6, wherein the sheet metal (10) is provided with at least one fixing tab (12) for fixing the sheet metal (10) to the support (11) of the vehicle.

8. Management system according to any one of claims 1 to 7, wherein the sheet metal (10) is located at a predetermined minimum safety distance from a purge pipe (5) connecting the housing (3) to an intake circuit of a vehicle engine.

9. Management system according to any one of claims 1 to 8, dependent on claim 2, wherein said shock is a rear shock of the vehicle.

10. Motor vehicle comprising an emissions management system fuel vapors according to any one of claims 1 to 9.

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