Fuel vapor emissions 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 an impact

Abstract

This system for managing fuel vapor emissions of a motor vehicle comprises a fuel tank and a fuel vapor recovery housing (3) connected by a filler pipe (4). The management system comprises disconnecting means (9) for the housing (3) and the tank comprising a sheet metal (10) arranged between the tank and the housing (3), having a stiffness greater than that of the housing (3), and extending vertically from a support (11) of the vehicle towards the filler pipe (4), the sheet metal (10) extending beyond an outer edge (4a) of the filler pipe (4). Figure for abstract: Figure 3

Description

Title of the invention: System for managing fuel vapor emissions from 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 an impact Technical field

[0001] The invention relates to the field of systems for managing fuel vapor emissions from 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 engine (petrol), the fuel vapor recovery box, known to those skilled in the art by its English name "canister", comprises a carbon filter and is configured to accumulate the fuel vapors escaping from the tank through a filler pipe.

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

[0004] In the event of a significant impact to the vehicle, it is possible for the canister to be crushed and for carbon particles to pass from the canister to the non-return valve through the filler 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. Statement of the invention

[0006] The invention aims to prevent the transit of carbon particles from the canister to the non-return valve, in the event of the canister being crushed by an impact from the vehicle.

[0007] The subject of the invention is a system for managing fuel vapor emissions from a motor vehicle comprising a fuel tank and a fuel vapor recovery housing connected by a filler pipe.

[0008] The management system comprises means for disconnecting the housing and the tank comprising a sheet metal disposed between the tank and the housing, the sheet metal having a greater stiffness 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 an impact of the vehicle moving the housing towards the sheet metal, the filling pipe abuts against a vertical edge of the sheet metal, so as to create a shear force of the filling pipe reaching a predetermined shear threshold value, representative of a disconnection of the housing and the tank. Such a configuration allows automatic disconnection of the housing and the tank in the event of an impact of the vehicle.

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

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

[0012] Preferably, the sheet metal is metallic. A metal sheet 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 lug 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 purge pipe connecting the housing to an intake circuit of a vehicle engine. Such a configuration ensures that the purge pipe does not abut against the sheet metal.

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

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

[0018] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

[0019] [Fig-1] illustrates a direct orthonormal XYZ reference frame classically used in automobile design;

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

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

[0022] For the purposes of the description, reference will be made to a direct orthonormal XYZ reference frame conventionally used in automobile design and illustrated in [Fig.l]. In this reference frame, the X axis designates the front-rear longitudinal direction of the vehicle, oriented backwards, 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] [Fig. 2] is a partial view from below of a rear part of a motor vehicle comprising a fuel vapor emissions management system 1 according to one embodiment of the invention. The management system 1 comprises a fuel tank 2 and a fuel vapor recovery housing 3 or canister.

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

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

[0026] The canister 3 is connected to the vehicle engine intake by a purge pipe 5 equipped with a purge valve (not referenced) the opening of which controls the passage of fuel vapors towards 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 arranged at the rear and in the immediate vicinity of the tank 2.

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

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

[0030] Crushing the canister 3 presents the safety risk linked to the release of carbon particles and the clogging of the non-return valve described above.

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

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

[0033] The disconnection device 9 comprises a sheet 10 arranged between the tank 2 and the canister 3 and fixed on at least one support 11 of the vehicle. The support 11 may be a cross member, a side member or a sheet metal. The fixing of the sheet metal 10 on the support 11 may in particular be carried out by spot welds or by weld beads, and / or by fixing means such as screws or bolts.

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

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

[0036] Preferably, the level Z0 of the sheet 10 is located at a predetermined minimum safety distance from the purge pipe 5. Alternatively, it remains possible for the level Z0 to be below the external diameter D5 of the purge pipe 5, i.e. for the sheet 10 to exceed an external edge of the purge pipe.

[0037] The sheet 10 has a stiffness in the front-rear longitudinal direction greater 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 10 is smaller than the resulting displacement of the canister 3.

[0038] Thus, during a significant rear impact, the filler pipe 4 abuts against a vertical edge 13 of the sheet metal 10, creating a shearing of the pipe 4. The energy of such an impact is dissipated mainly by the deformation of the rear part of the vehicle. The difference between the forward movements respectively of the canister 3 and the sheet metal 10 increases, as this deformation progresses, and results in an increasing shearing force of the filler pipe 4, reaching a predetermined shear threshold value which disconnects the filler pipe 4 from the canister 3. The disconnection of the filler pipe 4 from the canister 3 can occur in particular by the rupture of the filler pipe 4 or by the tearing of the filler pipe 4 from the canister 3. The predetermined shear threshold value is thus representative of the disconnection of the canister 3 and the tank 2.

[0039] In order to increase the stiffness of the sheet 10, it is possible to provide reinforcements, such as stiffeners or stamped areas, on at least one lateral face 14 of the sheet 10. Here, the sheet 10 is reinforced by a stamped central area 15. Alternatively, it is possible to provide vertical stiffeners of the rib or fin type on the lateral face 14.

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

[0041] Preferably, the sheet 10 is metallic.

[0042] As indicated previously, in the illustrated embodiment, the canister 3 is arranged at the rear of the tank 2. Alternatively, it is possible to provide different configurations. For example, the canister 3 may be longitudinally opposite the tank 2 and transversely outside the tank 2.

Claims

Claims

1. Management system (1) for fuel vapor emissions of a motor vehicle comprising a fuel tank (2) and a fuel vapor recovery housing (3) connected by a filler pipe (4), characterized in that said management system comprises disconnection means (9) for the housing (3) and the tank (2) comprising a sheet metal (10) arranged between the tank (2) and the housing (3), the sheet metal (10) having a greater stiffness than that of the housing (3), and extending vertically from a support (11) of the vehicle towards the filler pipe (4), said sheet metal (10) extending beyond an outer edge (4a) of the filler pipe (4).

2. Management system according to claim 1, wherein during an impact of the vehicle moving the housing (3) towards the sheet metal (10), the filling pipe (4) abuts 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, in which the sheet metal (10) is provided with rounded stops (17).

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

5. A 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, in which 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, in which the sheet metal (10) is provided with at least one fixing lug (12) intended to fix 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 an engine of the vehicle.

9. A 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 of fuel vapors according to any one of claims 1 to 9.

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