FR2724692A1 - PUMPING ASSEMBLY INCLUDING A PRESSURE REGULATOR FOR A FUEL TANK OF A MOTOR VEHICLE AND RESERVOIR THUS EQUIPPED - Google Patents

Abstract

The present invention relates to a fuel supply device for an internal combustion engine comprising a drawing assembly (200) comprising a fixing base (210) designed to be fixed to a wall of a fuel tank (R), a pump (220), at least one supply duct (212) connected to the outlet of the pump (220), a filter (250) placed on this supply duct and a pressure regulator (300) associated with the pump , the pressure regulator (300) and the filter (250) being fixed on the base of the drawing assembly (200) and the pressure regulator (300) being supported by the housing (252) of the filter (250) , characterized in that the regulator (300) is placed downstream of the filter (250), and the filter (250) comprises a filtering structure (254) in the form of a crown, supplied from the outside by the outlet of pump (220), while the regulator (300) is placed in the central part (257) of the filter structure (254) .

Description

The present invention relates to the field of power supply devices

  in fuel from internal combustion engines on

motor vehicles.

  As shown diagrammatically in the appended FIG. 1, the conventional fuel supply systems for internal combustion engines comprise a pump 10 which takes the fuel from a tank 12, and directs this fuel to the area of use, for example the injectors or the intake manifold 14, via a supply pipe 16. The excess fuel is returned to the tank 12 using a return pipe 18. The pump 10 generally comprises a filter upstream 11. In addition, a downstream filter 13 is generally placed at the outlet of the pump 10, on the supply pipe 16. This conventional arrangement, known as a loop, shown in FIG. 1, has the disadvantage of leading to heating of the fuel passing through the zone of use 14 and brought back to the tank 12

through the return duct 18.

  To avoid this heating of the fuel and consequently to decrease the emissions of vapor of the fuel accumulated in the tank 12, it has been proposed, as shown diagrammatically in FIG. 2, so-called dead-end supply systems, in which the back 18 is deleted. In this case, as shown diagrammatically in FIG. 2, a pressure regulator 20 is preferably integrated on the supply line 16. This pressure regulator 20 ensures the return of the excess fuel, to the tank 12. This pressure regulator 20 has its inlet connected to the supply line 16, generally downstream of the filter 13, by a bypass duct 15. The outlet of the regulator 20

opens into the reservoir 12.

  More specifically, as illustrated in FIG. 3, the applicant has proposed for several years systems applying the principle recalled above and which include: - an upper base 100 designed to be fixed to a tank wall, - conduits 102, 103 fixed to the base 100, - a pressure regulator 104, - a pump 106 fitted with a filter 108 at its inlet and - a level gauge 110 essentially comprising a float 112 fixed on a pivoting arm 114 and designed to control, through

  of a slider, a resistive transducer 116.

  The outlet of the pump 106 is connected to the inlet of the filter 13 outside the reservoir, via the conduit 102. The outlet of the filter 13 is connected to the injectors 14. It is also connected to the inlet of the regulator 20, via conduit 103, which is connected to the

  bypass duct 15 shown in FIG. 2.

  The resulting assembly of regulator 104 is quite complex.

  Document US-A-5078167 describes a variant according to which the drawing assembly comprises a fixing base designed to be fixed on the wall of a fuel tank, a pump, a supply duct connected to the outlet of the pump, a filter placed on this supply pipe and a pressure regulator associated with the pump, placed between the pump outlet and the filter inlet, the pressure regulator and the filter being fixed on the base of the and the water regulator

  pressure being supported by the filter housing.

  The arrangement thus described in document US-A-5078167 essentially aims to increase the life of the filter, by filtering only the fuel used. However, this provision is not entirely satisfactory. To control the pressure regulator with the pressure of

  output from the filter, it imposes a relatively complex structure.

  The present invention now aims to improve

  existing fuel delivery systems.

  This object is achieved according to the present invention by a device for supplying fuel to an internal combustion engine of the type comprising a drawing assembly comprising a fixing base designed to be fixed to the wall of a fuel tank, a pump , at least one supply duct connected to the pump outlet, a filter placed on this supply duct and a pressure regulator associated with the pump, the pressure regulator and the filter being fixed on the base of the drawing assembly, and the pressure regulator being supported by the filter housing, characterized in that the pressure regulator is placed downstream of the filter and the filter comprises a filtering structure in the form of a crown, fed by the outside, through the pump outlet, while the pressure regulator is placed in the

  central part of the filter structure.

  The invention also relates to the fuel tanks thus equipped. Other features, purposes and advantages of this

  invention will appear on reading the detailed description which will

  follow, and with reference to the appended drawings given by way of nonlimiting examples and in which: - Figures 1 to 3 previously described schematically illustrate arrangements according to the state of the art, - Figure 4 shows a schematic view in section of a first embodiment according to the present invention, - Figure 5 shows a schematic sectional view of a second embodiment of the present invention, - Figure 6 shows a schematic view in axial section of a regulator according to the invention, and Figure 7 shows a partial schematic sectional view, along a transverse sectional plane referenced VII-VII in Figure 4, of a device

according to the present invention.

  Schematically shown in Figure 4 attached, a device

  fuel supply according to the present invention.

  This device is designed to be placed in a fuel tank of a motor vehicle, which is only partially represented in the appended FIG. 4, under the general reference R Such a fuel tank R can be the subject of

  many variants.

  More specifically, in FIG. 4 appended, only part of the upper wall R1 and part of the lower wall R2 of the reservoir R are shown. The device 200 according to the present invention comprises a base 210 which supports a drawing assembly essentially comprising a pump 220, a filter 250 and a pressure regulator 300. The base 210 is adapted to be fixed to the upper wall

  R1 of the tank R, opposite an access orifice formed therein.

  The base 210 is preferably made of plastic. Its geometry can be the subject of numerous variants. It is preferably generally circular, centered around a vertical axis. Of course, the schematic representation of the base 210 given in the appended figures should not be considered as limiting. The base 210 can be fixed to the upper wall R1 of the tank by any suitable means. It is preferably a removable mounting. The base 210 is advantageously fixed by means of a ring held by screwing or locking with the interposition of an annular seal, on the upper wall R1 of the tank R. The base 210 serves as a support for an outlet pipe of fuel 212. The base 210 also serves as a support for electrical connections 214. These electrical connections, schematically represented in FIG. 4, are intended to allow, on the one hand the supply of the pump 220, on the other share the establishment of an electrical connection with a gauging device 400, preferably equipping

the drawing assembly 200.

  The connections 214 can be the subject of numerous variants. Their number depends on the nature of the gauging means 400 and

of the pump 220 used.

  Preferably, the base 210 is overmolded on these connections

214.

  According to the representation given in Figure 4, the upper base 210 is provided with an underlying mount 216, preferably formed of a cylindrical barrel, adapted to support the assembly of

drawing 200.

  The pump 220 can be the subject of numerous variant embodiments. It is preferably a conventional electrically controlled pump. The pump 220 is advantageously placed in a bowl 240 serving as a fuel reserve, connected by its upper end to the base of the frame 216. The bowl 240 can thus be rigidly fixed on the frame 216. However, preferably, as shown in FIG. '' will explain later, the bowl 240 is connected to the frame 216 by means of a telescopic assembly, so that the bowl 240 is constantly stressed

  against the lower wall R2 of the tank.

  The reserve bowl 240 can be supplied itself by any suitable means, for example using a booster pump, or a pump such as a jet pump, or even using a valve. non-return valve, as shown diagrammatically under reference 242, in the bottom of the bowl 240, to allow fuel to penetrate from the tank R to the bowl 240 when the level of fuel in the tank R is higher than that of the fuel in the bowl 240, while on the contrary preventing the flow of fuel from the bowl 240 to the tank R. The inlet of the pump 220 is placed near the bottom of the bowl 240, that is to say near the bottom of the tank R. The inlet of pump 220 is

  preferably provided with an upstream filter 222 adjacent to the bottom of the bowl 240.

  The outlet of the pump 220 is preferably provided with a nozzle.

  vertical 224 tightly connected to the inlet of the filter 250.

  The filter 250 comprises a casing 252, advantageously cylindrical, placed in the mount 216, on the top of the bowl 240. The casing 250 can be the subject of numerous variants. It is preferably formed by assembling two cylindrical shells, in material

plastic or metal.

  The housing 252 houses a filter structure 254 in the form of a crown. The filter structure 254 can be formed by any suitable means. It is preferably a conventional filter structure with

  paper base, shaped like a labyrinth for the fuel to be filtered.

  The two sides 253, 255 of the filter structure in crown 254 are tightly connected to the facing walls respectively

  lower 251 and upper 258 of the housing 250.

  It is further defined, inside the housing 252, on the one hand on the outer periphery of the filter structure 254, an inlet chamber 256, and on the inner periphery of the filter structure 254,

an outlet chamber 257.

  The outlet nozzle 224 of the pump 220 opens into the

  radially outer inlet chamber, 256, of the filter 250.

  Furthermore, the regulator 300 is placed in the internal chamber

257.

  The bottom wall 251 of the filter housing 252 250 has, preferably at its center, and in the internal chamber 257, a generally cylindrical and stepped structure 260 which serves as a support for the regulator 300. More precisely, according to the particular embodiment shown in FIG. 4, this support structure 260 comprises two cylindrical sleeves 262, 264, connected by a radial recess 266. The sleeve 262 opens towards the bottom of the bowl 240. The sleeve 264 superimposed on the sleeve 262 has a larger diameter than this latest. The sleeve 264 also has at least one through bore 265 allowing communication between its internal volume and the internal chamber 257 of the

filter 250.

  Thus the pressure regulator 300 is placed downstream of the filter 250, more precisely of the filtering structure 254, so that it receives only filtered fuel. The regulated output of regulator 300 communicates with chamber 257. On the contrary, the output of regulator 300 corresponding to the fuel overflow communicates with the

  scabbard 262 and from there with bowl 240.

  The upper wall 258 of the housing 252 of the filter 250 is in turn provided with an end piece 270 sealingly connected to the end piece 212 carried by the base 210. The end piece 270 communicates with the outlet chamber 257

of the filter.

  The fuel is directed, from this nozzle 212, to the zone

  of use, injector (s) or carburetor (s), by any suitable conduit.

  Thus, the fuel used follows the following circuit: pump 220, external chamber 256 of the filter, filter structure 254, internal chamber

  257 of the filter 250, then connection between the nozzles 270 and 212.

  On the contrary, the excess fuel from the pump 220 follows the circuit: external chamber 256 of the filter 250, filter structure 254, internal chamber 257 of the filter 250, pressure regulator 300 and bowl 240

  through the sleeve 262.

  Sealing means 226 are provided between the outlet 224 of the pump 220 and the inlet of the filter 250. These sealed connection means can be formed for example of a flexible tube. Preferably, however, the outlet nozzle 224 of the pump 220 is arranged in the form of a sealed telescopic mounting in the base of the inlet chamber.

  radially external 256 of the filter 250.

  For this, for example, the outlet nozzle 224 of the pump 220 is engaged in a complementary nozzle 259 provided at the base of the inlet chamber 256, with interposition of sealing means 226. These sealing means can be the subject of many variations. These can be simple O-rings. However, preferably, these sealing means are formed of at least one lip seal, very preferably a seal having a cross section in V with concavity oriented axially. In other words, such a seal comprises two elastic lips inclined together in a V and oriented substantially

  parallel to the central axis of the joint.

  The connecting means between the outlet nozzle 270 of the filter 250 and the nozzle 212 carried by the base 210 can be comparable to those

  provided between outlet 224 of pump 220 and inlet of filter 250.

  Thus, the connection between the outlet end piece 270 of the filter 250 and the end piece 212 carried by the base 210 can be ensured by a flexible conduit 272 as illustrated in FIG. 4. However, as a variant, the end piece 270 can be arranged in sealed telescopic mounting in the endpiece 212 carried by the base 210, with the interposition of a seal, such as a seal with two lips having a V-shaped cross section, as described

  previously for pump output 220.

  The pressure regulator 300 is preferably a regulator with coaxial input / output. The pressure regulation function is obtained, using the regulator 300, by a bypass flow, regulated by a membrane supporting the combined action of the liquid whose pressure is

  regulated, and a calibration spring.

  We will now describe the structure of the regulator 300

  shown schematically in Figure 6 attached.

  According to this representation the regulator 300 comprises a body

  302 generally cylindrical of revolution about a vertical axis 304.

  The body 302 is provided with a collar 310 or rib projecting from its outer surface, substantially halfway up. The body 302 is split into

  two chambers by a flexible membrane 330, transverse to the axis 304.

  The outer periphery of the membrane 330 is tightly fixed on the inner surface of the body 302. For this purpose, preferably, the outer periphery of the membrane 330 is pinched by the body 302 at

flange level 310.

  The upper chamber 332 delimited in the body 302 by the

  membrane 330 receives a calibration spring 340.

  The lower chamber 334 located on the other side of the membrane 330 receives a projecting tube 324, centered on the axis 304. This tube 324 extends on the outside of the body 302, towards the bowl 240 in the form of

the aforementioned tip 320.

  The tube 324 is tightly connected to the body 302. The top 325 of the internal tube 324 is located near the membrane 330, more

  precisely opposite a shutter 331 supported by the latter.

  Those skilled in the art will understand that thus the spring 340 pushes the shutter

  331 against the top of the tube 320, to close the latter.

  In addition, the lower chamber 334 is connected to the outside, either with the filter outlet chamber 257, through through passages 335 formed in the body 302 at the base thereof, around the nozzle 320. From

  preferably, several passages are thus provided crossing 335 equi-

distributed around axis 304.

  When the pressure of the fuel supplied to the lower chamber 334, via the passages 335, is lower than the setting pressure of the spring 340, the shutter 331 is pressed against the top of the tube 325. Thus, the fuel cannot flow out of the room

  lower 334 to the bowl 240, via the outlet tube 324.

  On the other hand, when the fuel pressure in the chamber 334 becomes higher than the spring setting pressure 340, the membrane 330 and the shutter 331 are spaced from the top of the tube 325. The fuel can then flow from the lower chamber 334 towards end piece 320 via

  tube 324, and from there join the bowl 240.

  The body 302 is provided under the collar 310 and above the passages 335, with an annular groove 306, designed to receive an annular seal 308 ensuring the seal between the body 302 and the internal surface of the sleeve 264 linked to the wall lower 251 of housing 252 of

filtered.

  Preferably a second annular seal 321 seals between the outer surface of the end piece 320 and the sleeve 262 in which

is engaged this tip 320.

  The regulator 300 can be fixed on the sleeves 262, 264 linked to the housing 252 by any suitable means, for example by a ring 309 engaged with the external surface of the body 302 and with the internal surface of a third sleeve 267 linked to the second sleeve 266 through a

dropout 268.

  In a manner known per se, the base 210 is placed opposite an access and inspection hatch provided on the chassis of the vehicle. Therefore, the filter 250 is easy to access since it suffices to disassemble the base 210 to

access this filter.

  Consequently, the filter 250 can be replaced without difficulty at any service station when the mileage of the vehicle reaches a

  required threshold defined by the manufacturer.

  In conventional structures, the pump bodies 220 are immobilized in mounts, using shock absorbers generally provided in the lower part and in the upper part respectively.

of the pump.

  In the context of the invention, due to the close cooperation defined between the outlet nozzle 224 of the pump 220 and the inlet of the filter 250, preferably, the damper generally provided in part

  upper part of the pump is replaced by flexible connecting means.

  Compared to the known prior arrangements, according to which the filter equivalent to the filter 250 is generally placed in an external breach of the reservoir, the present invention notably offers the following advantages: - it makes the conventional fire and anti-gravel protection of the filter unnecessary , - it simplifies the geometry of the container since it avoids the creation of such an infringement intended to house the filter, - it eliminates the loss of volume linked to this infringement (it should be noted that the volume of this infringement corresponds to a loss capacity is very often much greater than the volume of the filter), - it avoids any risk linked to a leak at the level of the connection between the pump and the filter, or the filter and the base, since any leak at this level,

  according to the invention, is automatically recovered in the bowl 240.

  According to the embodiment shown in FIG. 4, the upper chamber 332 of the regulator 300 being sealed, the regulator works with an absolute reference pressure

  corresponding to the pressure which reigns at rest in this chamber 332.

  On the other hand, FIG. 5 shows an alternative embodiment according to which, as also shown diagrammatically in FIG. 6, this upper chamber 332 of the regulator 300 has at least one through passage 303 through which the chamber 302

  communicates with an auxiliary pressure reference.

  More precisely, according to the representation given in the figure, the upper chamber 332 of the body 302 is placed in a recess 280 formed in the upper wall 258 of the housing 252. The seal between the outer surface of the body 302 of the regulator 300 and a sheath 281 linked to the clearance 280 is provided by the seal 308. The regulator 300 is fixed in the clearance 280 by the ring 309. The passage 303 thus communicates with the upper part of the reservoir R. The regulator 300 rests by its flange 310 on a recess 282 connecting the sheath 281 and the clearance 280. The end piece 320 is engaged in a sheath 262 linked to the bottom wall 251 of the filter

  and a seal 321 seals between this end piece 320 and this sleeve 262.

  This passage 303 formed in the body 302 of the regulator 300 can in other ways be connected, by means of an appropriate conduit, to the outside of the reservoir R, to be placed at atmospheric pressure, or even at the pressure of the engine intake manifold. Upstream filters 108 or primary filters generally have, according to conventional installations, a particle filtering power greater than 701tm. The downstream filter 13 on the other hand has

  generally a filtering power in the range 3-101tm.

  In the context of the invention, it is proposed to use a filter 222 with a filtering power capable of retaining particles of the order of 20 to 30 μm. This arrangement makes it possible to use a downstream filter 250 il with the same filtering powers of 3 to 10Fm as conventional installations, but with a smaller filtering surface, and consequently to reduce the size of this downstream filter 250 to allow its integration.

  on the base 210, in the tank.

  Of course the present invention is not limited to the particular embodiment which has just been described but extends to any variant

conforms to his spirit.

  In particular, the drawing-off assembly 200 can be equipped, as mentioned above, with a system for gauging the level and / or volume of fuel in the tank R. Such a gauge equipping the pumping assembly can comply with the provisions known and marketed nowadays and essentially comprising a housing 402 fixed on the frame 216 or on the bowl 240, a resistive track placed in the housing, a float 404 able to follow the evolutions of the fuel level and a cursor linked directly to the float or linked to it by means of a pivoting lever, which cursor moves on the resistive track according to the evolutions of the float. The gauge can also be formed from any other known structure,

for example a capacitive gauge.

  Furthermore, according to the preferred embodiment shown in Figure 4, the bowl 240 is mounted to slide vertically, on the base of the mount 216. If necessary, the bowl 240 can be biased against the bottom wall R2 of the tank R by simple gravity. However, preferably, at least one spring is interposed between the frame 216 and the bowl 240. Thanks to this indexing on the bottom, in a manner known per se, the bowl 240, and consequently the pump 220 as well as the gauging device associated 400, follow the bottom of the tank R2 whatever the deformations thereof, for example under the effect of the weight of the fuel, the manufacturing differences or even as a function of the temperature or

  due to aging of the tank.

  According to the embodiment shown in Figure 4, the base

  210 horizontal is fixed to the upper wall Ri of the tank.

  However, as a variant, the base 210 can be inclined to the horizontal, see fixed to a side wall of the tank R. Similarly, the indexing on the bottom R2 of the tank can be obtained not by telescopic mounting in one direction vertical, but by pivoting mounting

  around a horizontal axis of the drawing / gauging assembly.

  According to another optional feature of the invention, the upper part of the filter housing 252 250 can be arranged directly in the form of a base provided with the outlet pipe 212. The ends 270 and 212 are then combined. This arrangement makes it possible to reduce the number of hydraulic connections required and to reduce

  also the height of the system.

  Compared to previous fuel suction sets

  known, the present invention offers many advantages.

It saves space.

  It simplifies the structure.

  It reduces the number of parts used.

  It makes it possible to use filtered fuel in the regulator 300 and consequently makes it possible to avoid any clogging or any drift of the

regulator 300.

  It makes it possible to deliver fuel at constant pressure to the site of use, injector or carburetor, whatever the state of the filter 250. According to a variant, as shown in FIG. 7, the outer casing 290 of the filter 250 may be in the form of a cylinder of revolution locally comprising a projection 292 at the level of which the connection and sealing means are located with the outlet 224

pump 220.

Claims (17)

  1. Device for supplying fuel to an internal combustion engine comprising a drawing assembly (200) comprising a fixing base (210) designed to be fixed to a wall of a fuel tank (R), a pump (220 ), at least one supply duct (212) connected to the outlet of the pump (220), a filter (250) placed on this supply duct and a pressure regulator (300) associated with the pump, the regulator pressure (300) and the filter (250) being fixed on the base of the drawing assembly (200) and the pressure regulator (300) being supported by the filter housing (252), characterized by the fact that the regulator (300) is placed downstream of the filter (250), and the filter (250) comprises a filtering structure (254) in the form of a crown, supplied from the outside by the pump outlet (220 ), while the regulator (300) is placed in the central part (257) of the filter structure (254).   2. Device according to claim 1, characterized in that the regulator (300) is supported by a stepped structure (260) coming from the filter housing (252) (250).   3. Device according to one of claims 1 or 2, characterized   by the fact that a tight connection is provided between the outlet of the pump (220) and the filter inlet (250).   4. Device according to one of claims 1 to 3, characterized by   the fact that a tight connection (272) is provided between the outlet of the filter   (250) and an outlet nozzle (212) carried by the base (210).   5. Device according to one of claims 3 or 4, characterized   by the fact that the sealed connection comprises a flexible tube (272).   6. Device according to one of claims 3 or 4, characterized   by the fact that the sealed connection comprises a telescopic mounting with sealing means interposed.   7. Device according to claim 6, characterized in that the sealing means comprise at least one annular seal (226) at   two lips having a V-shaped cross section with axial concavity.   8. Device according to one of claims i to 7, characterized by   the fact that the regulator (300) comprises a body (302) provided with a waterproof membrane (330) delimiting two chambers, one (332) provided with a calibration spring (340) which biases the membrane, the another having at least one inlet through passage (335) and an outlet passage (320) which communicates with a conduit (324) cooperating with a shutter (331) linked to the membrane. 9. Device according to claim 8, characterized in that the chamber (332) housing the calibration spring is a sealed closed chamber. 10. Device according to claim 8, characterized in that the chamber (332) which houses the calibration spring (340) has at least one through passage (303) through which this chamber is   connected to an auxiliary pressure reference.   11. Device according to claim 10, characterized in that the auxiliary pressure reference is formed by the upper wall of the tank, the atmospheric pressure, or the manifold pressure engine intake.   12. Device according to one of claims 1 to 11, characterized   by the fact that the pump (220) comprises an upstream filter (222) adapted to retain particles of the order of 20 to 30 km and that the filter (250) located downstream of the regulator (300) is adapted to retain the particles of the order of 3 to 1iOnm.   13. Device according to one of claims 1 to 12, characterized   by the fact that it further comprises a gauging assembly (400).   14. Device according to one of claims 1 to 13, characterized   by the fact that the pump (220) and / or the gauging device (400) are indexed on the bottom.   15. Device according to one of claims 1 to 14, characterized   by the fact that the upper part of the downstream filter (250) is shaped as   mounting base on the tank wall.   16. Device according to one of claims 1 to 15, characterized   by the fact that the outer casing (290) of the filter (250) is in the form of a cylinder of revolution locally comprising a protuberance (292) at the level of which are located the means of connection and sealing with the outlet (224) of the pump (220).   17. Tank fitted with a supply device conforming to one of claims 1 to 16.