EP0965748B1 - Fuel gauging and drawing system for automotive vehicle fuel tank and tank equipped therewith - Google Patents

Description

The present invention relates to the field of gauging and fuel drawing assemblies in a motor vehicle tank.

Even more precisely, the present invention relates to means for supporting a fuel gauging and drawing assembly with respect to a base intended to be fixed to a wall of the tank.

Schematically illustrated in Figures 1 and 2 attached fuel gauging and drawing systems according to conventional arrangements according to the state of the art.

Most fuel tanks for motor vehicles are nowadays made of plastic. As a result, it is frequently found that the bottom 12 of these tanks can deform and move typically by several mm, under the effect of the weight of the fuel and thermal effects. This is why the gauging and drawing systems 20 are generally mounted in translation relative to the base 30 fixed on the wall of the tank 10 and are biased towards the bottom 12 of said tank, as shown schematically on Figures 1 and 2. This arrangement has the main purpose of allowing the gauging device 20 to take reference relative to the bottom 12 of the tank, regardless of the deformation thereof.

In FIGS. 1 and 2, the means for translational guiding and for urging the gauging and drawing assembly 20 are referenced 40.

However, the Applicant has found that this arrangement is not always satisfactory, in particular when the support base 30 is not fixed to a horizontal upper wall of the tank, but to an inclined wall. Indeed in this case the gauging and drawing assembly 20 may not be properly pressed against the bottom 12 of the tank, as seen for example in Figure 2. In addition in this case the contact point on the bottom 12 of the reservoir depends both on the relative inclination, itself fluctuating, between the support wall of the base 30 and the bottom 12 of the reservoir, and the indexing of the base 30 on its support wall, that is to say of the angular position of this base 30 relative to its support wall around the axis of translation of the gauging and drawing assembly.

The present invention now aims to propose new means having higher performance than that of the known prior devices.

The object of the present invention is in particular to provide means allowing reliable gauging and drawing whatever the inclination of the tank support wall which carries the base of this gauging and drawing assembly, and whatever the deformation of the tank bottom.

These aims are achieved in the context of the present invention by means of a fuel gauging and drawing system comprising a support base intended to be fixed to a tank wall and a gauging and drawing assembly mounted to move on the base. support and biased towards the bottom of the tank, relative to this base, characterized in that the connection means between the support base and the gauging and drawing assembly comprise at least two guide assemblies allowing one a translation and a relative swiveling and the other a translation and a displacement along a plane passing through the associated axis of translation.

Preferably, the above-mentioned travel plane also passes through the axis of translation of the first guide assembly.

The present invention also relates to the tanks thus equipped.

• les figures 1 et 2 précédemment décrites illustrent des dispositifs conformes à l'état de la technique,
• la figure 3 représente une vue schématique en coupe verticale d'un dispositif conforme à la présente invention,
• la figure 4 représente une vue schématique en coupe horizontale des moyens de guidage conforme à la figure 3,
• la figure 5 représente une vue schématique en coupe verticale d'une variante de dispositif conforme à la présente invention,
• la figure 6 illustre schématiquement un dispositif conforme à la présente invention implanté dans un réservoir de carburant,
• la figure 7 représente schématiquement un dispositif conforme à une autre variante de la présente invention, et
• la figure 8 illustre une vue schématique en coupe verticale, d'un dispositif conforme à une autre variante de réalisation de la présente invention.

Other characteristics, aims and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the appended drawings, given by way of nonlimiting examples and in which:

• FIGS. 1 and 2 previously described illustrate devices according to the state of the art,
• FIG. 3 represents a schematic view in vertical section of a device according to the present invention,
• FIG. 4 represents a schematic view in horizontal section of the guide means according to FIG. 3,
• FIG. 5 represents a schematic view in vertical section of a variant of the device according to the present invention,
• FIG. 6 schematically illustrates a device in accordance with the present invention installed in a fuel tank,
• FIG. 7 schematically represents a device according to another variant of the present invention, and
• FIG. 8 illustrates a schematic view in vertical section, of a device according to another alternative embodiment of the present invention.

We see in Figure 3 attached a device according to the present invention comprising a gauging and drawing assembly 120 and a support base 130. These can be the subject of many embodiments known per se. They will therefore not be described in detail later.

It will simply be noted that essentially, the gauging and drawing assembly 120 comprises a pump and a means for detecting the fuel level in the tank, for example with float control, while the support base 130 comprises a plate 132 adapted to be fixed in leaktight manner to a wall of the tank and which is traversed on the one hand by pipes connected to the pump and on the other hand by connections connected to the level detection means.

In the following description, we will describe only the specific guide means, in accordance with the present invention, defined between the support base 130 and the gauging and drawing assembly 120.

As can be seen in FIG. 3, the support base 130 is provided with two chambers 140, 150 which open on its lower surface, in the direction of the assembly 120.

These two chambers 140 and 150 are centered on parallel axes 145, 155.

One 150 of the two chambers has a circular straight section of revolution and constant over its entire length.

The other chamber 140, on the other hand, has an oblong and constant section over its entire length.

As illustrated in FIG. 4, preferably the cross section of this chamber 140 is delimited by two circular sectors 141, 142 interconnected by two flats 143, 144 parallel to each other. Preferably, these two flats 143, 144 are parallel to the plane defined by the axes 145, 155 of the two chambers 140, 150.

The drawing assembly 120 is in turn provided at its top with two drums 122 and 124 adapted to be engaged in the chambers 140 and 150 respectively.

As can be seen in FIG. 3, preferably each of the barrels 122, 124 is provided with a protrusion 123, 125 in the form of a spherical cap, in the vicinity of its upper end.

The cross section of the barrels 122, 124 is in turn smaller than that of the chambers 140, 150.

The protuberance 125 has a diameter complementary to the diameter of the chamber 150. Thus the protrusion 125 and the associated barrel 124 are capable of translation inside the chamber 150 along the axis thereof, in a generally vertical direction and / or a swiveling relative to the latter around the center of the protrusion 125.

The protrusion 123 has a diameter complementary to the distance separating the two flats 143 and 144. Thus the protrusion 123 and the associated barrel 122 are capable of translation inside the chamber 140 and / or of a clearance relative to the latter transversely to the axis 145 and parallel to the flats 143, 144. Therefore the cooperation defined between the ball joint 123 and the chamber 140 ensures indexing of the assembly 120 relative to the base 130.

This guide structure according to the present invention allows precise guidance of the assembly 120 allowing permanent support of the latter by its lower surface, on the bottom of the tank, whatever the deformations of this bottom (rotation and / or translation ) and / or its inclination relative to the wall of the tank which carries the base 130, as shown diagrammatically in FIG. 6.

It will also be noted that preferably the drums 122, 124 are hollow and receive descending columns 146, 156 secured to the bottom of the chambers 140, 150 and centered thereon.

These columns 146, 156 serve as central support for spiral springs 147, 157 interposed between the base 130 and the assembly 120, to urge the latter towards the bottom of the tank.

More precisely still, the springs 147, 157 bear respectively on the bottom of the chambers 140, 150 and on recesses 148, 158 formed inside the barrels 122, 124.

There is illustrated in FIG. 5 an alternative embodiment according to which the columns 146, 156 integral with the base 130 and serving to guide the springs 147, 157 are replaced by rising columns 1460, 1560 integral with the top of the drums 122, 124 , and emerging beyond the spherical protrusions 123, 125, to provide the same guiding function for the springs 147, 157.

Preferably the above-mentioned columns 146, 156 and 1460, 1560 are frustoconical, tapered away from their support, so as not to disturb the above-mentioned relative movement between the base 130 and the assembly 120.

The device according to the present invention offers in particular the following advantages.

It makes it possible to compensate for all the faults in the tank, in particular all the deformations of the bottom thereof, by guaranteeing that the assembly 120 rests permanently on this bottom.

In addition, the device according to the present invention makes it possible to maintain an indexing of the assembly 120 relative to the support base 130. Thus the present invention makes it possible to precisely control the path of the gauging float and to avoid any collision of this float with the walls of the tank. This is particularly important with the tanks in use today because these tanks often have complex shapes adapted to take up the available space in the vehicle infrastructure.

The present invention also makes it easier to assemble the gauging and drawing devices, since it makes it possible to mount the gauging and drawing assembly 120 and the base 130 separately and successively.

It will be noted that it is important in the context of the present invention, that there is practically no clearance between the spherical ball joint 125 and the wall of the chamber 150 on the one hand and between the spherical ball joint 123 and the flats 143, 144 on the other hand. This play is typically less than 0.25mm in the context of the present invention.

Of course, the present invention is not limited to the particular embodiments which have just been described, but extends to all variants within the scope of the claims.

Thus, for example according to an alternative embodiment, it is possible to envisage reversing the arrangement of the guide means, by providing for example at least one of the ball joints 123 and / or 125 on the base 130 and the complementary chamber 140, 150 on the gauging and drawing assembly 120.

According to another alternative embodiment, the ball joint 123 and the associated chamber 140 could be replaced by a rectilinear central guide 1400 secured to one of the assembly 120 or the base 130 and defining the direction of authorized clearance and two lateral bearing surfaces 1230, for example in the form of spherical caps integral with the other of the base 130 or of the assembly 120 and resting on said guide 1400, as shown diagrammatically in FIG. 7.

According to yet another alternative embodiment, the direction of authorized clearance, defined for example by the flats 143, 144 parallel to each other, may not be parallel to the plane defined by the axes of the chambers 140, 150, but inclined relative to this plan.

According to yet another alternative embodiment, as illustrated in the appended FIG. 8, at least one of the guide assemblies can define a hydraulic connection between the gauging assembly 120 and the support base 130. This hydraulic connection is preferably defined by the guide assembly which provides translation and relative swiveling. We thus see in Figure 8, a hollow tube 156 secured to the support base 130 and which plunges into a barrel 124 secured to the gauging assembly 120. Thus the internal volume of the tubing 156 communicates with the internal volume of the barrel 124. The geometry of the upper end of the barrel 124 is adapted to ensure translation and swiveling relative to the pipe 156. There are also provided sealing means, such as an O-ring 170, preferably with radial compression, between the pipe 156 and the barrel 124. This seal 170 is preferably provided at the closer to the swiveling center.

Such a hydraulic connection can be used, for example, to convey fuel from a pump located in a tank to injectors or to a carburetor.

Claims (15)

1. A fuel gauging and drawing system for a motor vehicle tank, the system comprising a support unit (130) for fixing to a wall of the tank and a gauging and drawing assembly (130) movably mounted relative to the support unit (130) and urged towards the bottom of the tank relative to said unit, the system being characterized by the fact that the connection means between the support unit (130) and the gauging and drawing assembly (120) comprise at least two guide assemblies, one of them (125, 150) allowing translation and relative swiveling, and the other one of them (123, 140) allowing translation and swinging motion in a plane containing the associated translation axis (144).
2. A system according to claim 1, characterized by the fact that the swinging plane also contains the translation axis (155) of the first guide assembly (125, 150).
3. A system according to claim 1 or claim 2, characterized by the fact that the first guide assembly (125, 150) comprises a spherical ball (125) secured to one of the gauging and drawing assembly (120) and the support unit (130), the ball being engaged in a chamber (150) of complementary circular section formed in the other one of the support unit (130) and the gauging and drawing assembly (120).
4. A system according to any one of claims 1 to 3, characterized by the fact that the second guide assembly (123, 140) comprises a structure (123) secured to one of the gauging and drawing assembly (120) and the support unit (130) engaged in a chamber (140) of oblong section formed in the other of the support unit (130) and the gauging and drawing assembly (120).
5. A system according to claim 4, characterized by the fact that said structure is formed by a spherical ball (123) adapted to be capable of swinging in the associated chamber (140).
6. A system according to claim 4 or claim 5, characterized by the fact that the right section of the chamber (140) of the second guide assembly is defined by two circular sectors (141, 142) interconnected by two mutually parallel flats (143, 144).
7. A system according to claim 6, characterized by the fact that the two flats (143, 144) are parallel to the plane defined by the axes (145, 155) of the two chambers (140, 150).
8. A system according to any one of claims 1 to 3, characterized by the fact that the second guide assembly (123, 140) comprises a rectilinear central guide (1400) secured to one of the assembly (120) and the unit (130) and defining the authorized swinging direction and two lateral bearing surfaces (1230), e.g. in the form of spherical caps that are secured to the other one of the unit (130) and the assembly (120), and resting against said guide (1400).
9. A system according to any one of claims 1 to 8, characterized by the fact that it further comprises resilient means (147, 157) interposed between the unit (130) and the assembly (120) for urging the assembly towards the bottom of the tank.
10. A system according to any one of claims 1 to 9, characterized by the fact that the clearance in the two guide assemblies (123, 140; 125, 150) is less than 0.25 mm.
11. A system according to any one of claims 1 to 10, characterized by the fact that at least one of the guide assemblies (124, 156) defines a hydraulic connection.
12. A system according to claim 11, characterized by the fact that the hydraulic connection is formed by the guide assembly (124, 156) which provides translation and swiveling.
13. A system according to claim 11 or claim 12, characterized by the fact that sealing means (170) are provided between two duct segments (124, 156) forming the guide assembly and defining a hydraulic connection.
14. A system according to claim 13, characterized by the fact that the sealing means (170) are placed close to the center of swiveling.
15. A motor vehicle fuel tank, characterized by the fact that it includes a gauging and drawing system in accordance with any one of claims 1 to 14.