FR2846605A1 - Device for putting automobile fuel tank to atmosphere is housed in cavity in fuel tank and locked by lugs engaging arced locking ramps ensuring locking of cavity cover - Google Patents

Abstract

The device is housed in a cavity (8) of the tank (1) and fixed in it by two locking lugs (19) which engage arced locking ramps (22). This ensures the locking of the cavity closing cover (12). When the device is used as a petrol vapor purge canister (10) it has a truncated shape conjugate with the cavity and contains active carbon (27).

Description

The present invention relates to a venting device for a

  motor vehicle fuel tank. It is known that for a petrol tank, the 5 petrol vapors emanating from it must be adsorbed by a device called a canister which is placed near the tank in order to limit any risk of degradation of the pipes connecting the tank to the canister. It is also known that to improve the regeneration of the canister, it is desirable to

  dispose in a temperate environment. In addition, the canister must have its regeneration air intake port located high enough above the ground so as not to be reached by water inlets when the vehicle is traveling on wet roads.

  For diesel tanks supplying high pressure direct injection engines, a booster pump is often placed in the tank and it must also be protected from the ingress of water, dust and bacteria, the presence in particular of the latter two elements causing rapid clogging of the filter elements present for temperatures of

relatively high diesel.

  The object of the present invention is to eliminate the above drawbacks by providing a venting device for a fuel tank of a motor vehicle which is characterized in that the tank comprises by construction a cavity in which is

  housed the venting device.

  The venting device is shaped

combined with that of the cavity.

  The venting device is also

  removably attached to the corresponding portion of the shell wall of the reservoir secured to the bottom wall of the cavity.

  This device is removably attached to the aforementioned portion by locking means comprising at least two radially external opposite lugs of a lower end portion of the device passing through the bottom wall of the cavity and the wall portion of the shell of the reservoir. , and two arcuate ramps locking 5 integral with the external face of the wall portion of the envelope of the tank while being inclined in the same direction to allow the lugs to engage respectively on the two ramps and to exercise on the device of venting a force perpendicular to the bottom wall of the cavity ensuring the blocking of a closure cover of the cavity secured to the

  device opposite the locking pins.

  When the device is used as a canister for purifying petrol vapors emanating from the tank, the body of this canister is of substantially frustoconical shape conjugated with that of the cavity of the canister housing and flared upwards, contains activated carbon. gas vapor adsorption, is closed at its upper part by the cover integral with the latter 20 with the outer peripheral edge of the cover maintained in forced support by the locking means with lugs and ramps on an annular edge bordering l upper opening of larger diameter of the canister housing cavity, and has its frustoconical lower part 25 having purified air passages towards the outside through the bottom wall of the cavity

  and the shell wall portion of the tank.

  Preferably, the frustoconical lower part of the canister comprises internal ribs extending along generatrices of this part and separating the

  each other by slots constituting the purified air passages and a frustoconical grid for retaining the activated carbon and purified air passage is disposed in the frustoconical lower part of the canister being supported by the internal ribs.

  Advantageously, the lower end part of the canister is cylindrical and hollow, integral with the lower circular wall of the solid bottom of the canister, has at its free end the two diametrically opposite locking lugs, and purified air passage holes made in its side wall 5 in the space existing between the bottom wall of the canister housing cavity and the bottom wall of the canister, the space communicating with the air passages

  uncluttered from the bottom of the canister.

  The fuel tank is connected to the canister by a line connected substantially to the center of the canister closure cover and extending into the latter and another line connects the source of depression of the vehicle engine to the canister by being

connected to the cover.

  For a diesel tank, when the device is used to condense the humidity likely to be present in the air sucked into this tank, to filter this air and / or to sanitize it, it includes a rigid perforated tube crossing the cavity perpendicularly to the closure cover and fixed at its upper end to a central tube passing integrally through the cover and connected by a pipe to the reservoir, the lower end of the tube comprising the diametrically opposite locking lugs which, with the locking ramps, allow to keep the external peripheral edge of the cover forced to rest on an annular edge bordering the upper opening of the cavity, and a cylindrical filter is mounted around the tube which contains hygroscopic and bactericidal elements in the form of granules, which tube comprises in its lower end portion of the air passage holes in

the cavity.

  Preferably, the openings of the tube are made up

  by longitudinal slots extending over substantially the entire length of the tube.

  The lower end portion of the tube is closed off by a transverse partition situated above the air passage bores and the tube comprises, at this partition, an end support collar

bottom of the filter.

  The tube advantageously comprises at its upper part a transverse grid for retaining granular hygroscopic and bactericidal elements.

  The cavity is frustoconical.

  The cover for closing the cavity comprises, on its external face, gripping protrusions 10 allowing rotation of the cover and of the device in a locking or unlocking direction of the

  cover and device to or from the tank.

  The cavity is made in the upper part of the tank and the lower end of the device is protected from the exhaust gas pipe by a

thermal insulation screen.

  The invention will be better understood, and other aims,

  characteristics, details and advantages thereof will appear more clearly in the explanatory description which follows, made with reference to the drawings

  attached schematics given solely by way of example illustrating two embodiments of the invention and in which: - Figure 1 is a top view of a fuel tank 25 of motor vehicle equipped with the setting device air according to the invention; - Figure 2 is a sectional view along line II-II of Figure 1; FIG. 3 is an enlarged sectional view of the part circled in III of FIG. 2; - Figure 4 is a top view along arrow IV of Figure 3; - Figure 5 is a sectional view along the line V-V of Figure 3; - Figure 6 is a developed view of the locking ramps of the tank venting device; - Figure 7 is a partial sectional view along line VII-VII of Figure 3; and - Figure 8 is an enlarged view similar to

  that of FIG. 3 and representing a device 5 for venting the invention applying to a diesel tank.

  Referring to FIGS. 1 to 7, the reference 1 designates a fuel tank for a motor vehicle in the shape defined by the envelope wall 2 and comprising 10 a tube 3 for filling the fuel tank and a gauging device 4 and of drawdown housed in the tank. The tank 1 is fixed to the chassis of the vehicle by means of a support cradle 5 and a pipe 15 6, through which the gases can circulate.

  exhaust, passes under the tank 1 in the longitudinal direction of the vehicle. A thermal insulation screen 7 is provided between a bottom portion of the tank 1 and the exhaust pipe 6 to provide thermal protection of this tank.

  FIG. 2 shows that the reservoir has a raised part under which the exhaust pipe 6 passes, but it is understood that the

  tank can have any other shape.

  The tank 1 comprises by construction and obtained

  by blowing a cavity or technical space 8 defined by a part commonly called "bonding pad" 9, known per se, and stabilizing by stiffening the bottom of the tank by connecting it to the upper part of the latter.

  According to the invention, the device 10 or canister for adsorbing the gasoline vapors emanating from the tank 1 is housed in the bonding pad 9 and is preferably removably fixed to the corresponding portion 35 of the bottom wall of this tank as we will see it later. The canister 10 comprises a body 11 of generally frustoconical shape conjugated to the gluing pad 9 so as to follow the shape of the latter and widening towards

the top of the tank.

  The canister 10 is closed at its upper part of larger diameter by a cover 12 having the general shape of a circular plate secured to the upper end of the body 11 of the canister 10

  transversely to the latter's axis of symmetry.

  The cover 12 includes a central tube 13

  passing through the cover integrally with the latter and to which is connected a pipe 14 making it possible to connect the cavity 8 to the intake manifold (not shown) of the engine constituting a source of vacuum.

  The cover 12 further comprises another tube 15 passing through it while being removably attached thereto and to which is connected a pipe 16 opening into the tank 1 in the upper part thereof. The tubing 15 extends into the cavity 8 by

an oblique tube 15a.

  The cover 12 is provided on its external face with at least two gripping protrusions 17 having an ergonomic curved shape 18 for printing on the cover 25 12 and on the canister 10 which is integral with it, a rotation about the axis of symmetry of the canister in one way or the other to lock or unlock this assembly to or from a portion of the tank bottom wall

  1 using locking means.

  These locking means comprise at least

  two diametrically opposite lugs 19 produced at the lower free end of a hollow cylindrical part 20 secured to the solid circular bottom wall 21 of the canister 10, extending coaxially to the axis of symmetry of the canister.

  The locking means further comprise two arcuate ramps 22 arranged concentrically with the axis of symmetry of the canister 10 and integral with the external face of a portion 23 of the envelope wall 2 of the tank 1 and which are inclined in the same direction to allow the lugs 19 to engage respectively on 5 the two ramps 22 when locking the canister 10 to the tank to exert on the canister 10 a force directed downward relative to Figure 3 and perpendicular to the bottom wall 21 of the canister to ensure the locking of the latter in the cavity 8 of the 10 gluing pad 9 and of the cover 12 by

  through its external peripheral edge 12a held in abutment on an annular rim 2a of the upper wall portion of the envelope of the reservoir 1 bordering the opening of larger diameter of the cavity 15 8.

  The cylindrical part 20 of the canister 10 passes through a

  orifice 9al of the circular bottom wall 9a of the bonding pad 9 and an orifice 23a of the wall portion 23 of the reservoir joined integrally to the bottom wall 20a of the bonding pad 9.

  The circular openings 9al and 23a respectively of the bottom walls 9a and of the wall portion 23 each have two diametrically opposite notches 24 in which the two pins 19 can engage or disengage 25 respectively during locking or

  unlocking the canister 10 to or the tank 1.

  In the locked position of the canister 10 in the cavity 8, the bottom wall 21 of this canister is arranged parallel above the bottom wall 9a of the bonding pad 9 and the cylindrical part 20 provided with locking lugs 19 comprises in its side wall portion located between the walls 21 and 9a of the

  orifices 20a for the passage of purified air.

  The frustoconical lower part of the body 11 of the canister 10 defines with respect to the wall of the gluing pad 9 a frustoconical space and has internal ribs 25 extending along generatrices of this lower part and which are separated from each other by slots constituting purified air passages. A frustoconical grid 26 is housed in the frustoconical lower part of the canister body 11 while being supported by the ribs 25 of the canister and serves as a means of retaining activated carbon 27 filling practically all of the canister 10. Activated carbon makes it possible to adsorb the gasoline vapors from the tank 1. The cylindrical lower part 20 of the canister 10

  has partitions thereb 20b perpendicular to one another and making it possible to reinforce its rigidity, in particular at the level of the locking lugs 15 19.

  To lock the assembly constituted by the canister 10 and the cover 12 in the cavity 8 of the gluing pad 9, it suffices to introduce this assembly into the cavity 8 by passing the pins 19 through 20 through the notches 24 then, at using the protrusions 17, to rotate this assembly in a clockwise direction with respect to FIG. 4 so that the lugs 19 move respectively on the two ramps 22 until the two lugs 19 come each lock in a suitable form 22a formed at the end of each ramp 22 and making it possible to limit the rotation of the canister 10 and to retain it in its locked position. Thus, by way of example, it suffices to print on the cover 12 and on the canister 10 a rotation 30 of a quarter turn so that the canister is blocked in

the bonding pad 9.

  To unlock the canister 10 and the cover

  12, it suffices to carry out the reverse operations above of the locking.

  When gasoline vapors are present in the upper part of the tank 1, the mixture of air and gasoline vapors is sucked into the canister 10 through the line 16, the tube 15 and the tube 15a as indicated by the arrows. F1 and the gasoline vapors are adsorbed by the activated carbon 27 and the purified air passing through this carbon passes through the grid 26, the slots between the ribs 25, the space between these ribs and the facing wall. screw of the bonding pad 9, the space between the bottom wall 21 of the canister 10 and the bottom wall 9a of the bonding pad 9, the orifices 20a of the cylindrical part 20 and 10 the space between internal partitions 20b of part 20 for

  exit outside the tank 1.

  The gasoline vapors can be sucked by vacuum in the canister 10 which communicates with the intake manifold through the line 14 under the control of the engine control system and prevents the activated carbon from being saturated. During an air depression in the intake manifold, the air can flow from bottom to top with respect to FIG. 3 in the opposite direction to that resulting from the suction of the air and gasoline vapor mixture present. in the upper part of the tank for

purify it with activated carbon 27.

  The second embodiment of the invention shown in FIG. 8 applies to diesel tanks and the elements of this embodiment common to those of the embodiment described above and performing the same functions have the same references. According to this second embodiment, the air vent device fixed removably in the cavity 8 of the tank performs the functions of dehumidifying the air entering the diesel tank, filtering the dust contained in this air and d elimination of bacteria likely to be present in the incoming air. To this end, the device comprises a rigid tube 28 passing through the cavity 8 perpendicular to the cover 12 to which it is secured by its end

  upper and which has openings in its side wall formed by longitudinal slots 29 extending over practically the entire length of the tube 28.

  Alternatively, the openings 29 may be constituted by circular orifices. The tube 28 comprises at its lower free end the locking lugs 19 which, as in the previous embodiment, cooperate with the inclined locking ramps 22 of the lower wall portion 23 of the reservoir 1 to lock the tube 28 and the cover 12 to the reservoir by pressing the cover, by its external peripheral edge 12a, on the

ledge 2a.

  The tube 28 can be secured to the cover 12 by press fitting its upper end around the lower end of the central tube 13 penetrating into the cavity 8, the tube 13 communicating, by a pipe, with the upper part of the tank.

diesel.

  The tube 28 is closed at its end part

  lower 20 by a partition 30 fixed transversely in the tube 28 and situated above passages 31 made in the wall of the tube 28 above the bottom wall 9a of the gluing pad 9 so as to put the cavity 8 into communication with outside.

  A cylindrical filter 32 is mounted around the tube 28 coaxially therewith, being held between the cover 12 and a flange 33 of the tube 28 located substantially at the same level as the partition 30 and on which the lower end of the filter 32 is supported. This filter is thus a porous tube whose mesh size is smaller than that of the strainer protecting the booster pump (not shown) housed in the

diesel tank.

  The tube 28 contains hygroscopic and bactericidal granules 34 which are retained in the tube 28 in the lower part by the partition 30 and in the upper part by a grid 35 fixed transversely in

the tube 28 above the slots 29.

  The suction of the outside air as indicated by the arrows F2 in FIG. 8 ensures a dehumidification 5 of the air passing through the hygroscopic granules 34 and sucked in through the tube 13 communicating with the upper part of the diesel tank and the condensed water. on the cold wall of the bonding pad 9 flows along it and then through the small annular passage 10 existing between the lower end part of the tube

  28 and the orifices of the bottom wall 9a of the bonding pad 9 and of the wall portion 23 of the reservoir.

  In this way, the air sucked in by the pipe 13 is free of water droplets and relatively dry, thus preventing the formation of water at the bottom of the diesel tank capable of disturbing the operation of the booster pump. In addition, the development of bacteria in diesel fuel is prevented by the granules 34 which, with the elimination of water, makes it possible to increase the service life of the booster pumps by reducing the probability of

  clogging of the strainer by bacteria.

  The cover 12 is arranged to allow fixing in the tank either of the canister 10 with the addition of the regeneration tubing 15, or of the tube 28, i.e. the cover can be used

  for either of the two types of tank and it will suffice to give the cover different colors to immediately distinguish those intended for petrol tanks from those intended for diesel tanks.

  The attachment of the ba typennette type of the venting device in the cavity 8 of the reservoir allows rapid installation of this device in this reservoir and, once the device is fixed, it suffices to make the connections of the conduits of the device for venting to the tank during its preparation

  equipped with these various elements, hence a reduction in assembly time on the vehicle.

  It should also be noted that the arrangement of the lower orifice of the venting device in an area set back from the bottom of the tank ensures an air supply in a relatively calm area and, in any case, protected from the exhaust pipe through the heat shield.

Claims (15)

  1. Breather device for a fuel tank of a motor vehicle, characterized in that the tank (1) includes by construction a cavity (8)   in which is housed the venting device.   2. Device according to claim 1, characterized in that it has a shape combined with that of the cavity (8). 3. Device according to claim 1 or 2, characterized in that it is removably attached to the corresponding portion (23) of the envelope wall (2) of the tank secured to the bottom wall (9a) of the cavity (8).   4. Device according to claim 3, characterized in that it is removably fixed to the aforementioned portion (23) by locking means comprising at least two radially external opposite lugs (19) of a lower end part of the device passing through the bottom wall (9a) of the cavity (8) and the portion (23) of the enclosure wall of the tank, and two arcuate locking ramps (22) integral with the external face of the portion (23) of tank shell wall being inclined in the same direction to allow the pins 25 (19) to engage respectively on the two ramps (22)   and exerting on the air-venting device a force perpendicular to the bottom wall (9a) of the cavity (8) ensuring the blocking of a closure cover (12) of the cavity (8) integral with the device opposite the 30 locking lugs (19).   5. Device according to one of claims   above, used as a canister for purifying petrol vapors emanating from the tank, characterized in that the body of the canister (10) is of substantially frustoconical shape combined with that of the housing cavity (8) of the canister and flared towards the top contains activated carbon (27) for adsorbing petrol vapors,   is closed at its upper part by the cover (12) integral with this with the external peripheral edge (12a) of the cover (12) held in forced support by the latching means with lugs (19) and ramps (22) on 5 un annular edge (2a) bordering the upper opening of larger diameter of the housing cavity (8) of the canister (10), and at its frustoconical lower part comprising purified air passages towards the outside through the wall bottom (9a) of the cavity (8) and of the portion (23) of the enclosure wall (2) of the reservoir.   6. Device according to claim 5, characterized in that the frustoconical lower part of the canister (11) comprises internal ribs (25) extending along generatrices of this part and separated from each other by slots constituting the passages of purified air and in that a frustoconical grid (26) for retaining the activated carbon and for passage of purified air is arranged in the frustoconical lower part of the canister (11).   7. Device according to claim 5 or 6, characterized in that the lower end part of the canister (11) is cylindrical and hollow, integral with the lower circular wall of solid bottom (21) of the canister, has at its free end the two diametrically opposite locking lugs 25 (19), and purified air passage holes made in its side wall in the space existing between the bottom wall (9a) of the housing cavity (8) of the canister ( 10) and the bottom wall (21) of the canister (10), the space 30 communicating with the purified air passages of the part   lower frustoconical of the canister.   8. Device according to one of claims 5 to 7,   characterized in that the reservoir (1) is connected to the canister (10) by a pipe (15,16) connected 35 substantially to the center of the closure cover (12) of the canister (10) and extending in the latter and in another line (13,14) connects the vacuum source of the vehicle engine to the canister (10) in   being connected to the cover (12).   9. Device according to one of claims 1 to 4,   used to condense the humidity likely to be present in the air sucked into the diesel tank, to filter this air and / or to sanitize it, characterized in that it comprises a rigid perforated tube (28) passing through the cavity (8) perpendicular to the closure cover (12) and fixed at its upper end to a central tube (13) passing integrally through the cover (12) and connected by a pipe to the reservoir (1), the lower end of the tube ( 28) comprising the diametrically opposite locking lugs (19) which, with the locking ramps (22), make it possible to maintain in forced support the external peripheral edge (12a) of the cover (12) on an annular edge (2a) bordering the upper opening of the cavity (8), and in that a cylindrical filter (32) is mounted around the tube (28) which contains hygroscopic and bactericidal elements (34) 20 in the form of granules and comprises in its part lower end d the air passage holes (31) in the cavity (8).   10. Device according to claim 9, characterized in that the openings of the tube (28) consist of longitudinal slots (29) extending over practically the entire length of the tube (28).   11. Device according to claim 9 or 10, characterized in that the lower end portion of the tube (28) is closed by a transverse partition (30) 30 located above the holes (31) for air passage and the tube (28) comprises at this partition (30) a flange (33) for supporting the lower end of the filter (32).   12. Device according to one of claims 9 to 35 11, characterized in that the tube (28) comprises at its   upper part a transverse grid (35) for retaining granular hygroscopic or bactericidal elements (34).   13. Device according to one of claims 9 to   12, characterized in that the cavity (8) is of frustoconical shape whose opening of larger diameter is directed upwards.   14. Device according to one of claims   above, characterized in that the cover (12) for closing the cavity (8) comprises on its external face 10 gripping protrusions (17) allowing rotation of the cover (12) and of the device in a locking or unlocking the cover (12) and   from the device to or from the tank (1).   15. Device according to one of the preceding claims 15, characterized in that the cavity (8) is   made in the upper part of the tank (1) and the lower end of the device is protected from the exhaust gas line (6) by a screen thermal insulation (7).