WO2010122368A1

WO2010122368A1 - Liquid supply device for a vehicle

Info

Publication number: WO2010122368A1
Application number: PCT/IB2009/005752
Authority: WO
Inventors: Alain Brolh
Original assignee: Renault Trucks SAS
Current assignee: Renault Trucks SAS
Priority date: 2009-04-23
Filing date: 2009-04-23
Publication date: 2010-10-28
Anticipated expiration: 2011-10-23

Abstract

The invention relates to a liquid supply device for a vehicle for supplying a liquid contained in a tank of said vehicle to a liquid-consuming system, said supply device (16) being intended for fitting on an upper wall portion of a liquid-containing tank, said supply device (16) comprising at least a supply head (18) which is to be fitted on an upper wall portion of the tank, and, connected to the supply head, at least one pipe (20, 24, 26) having a lower extremity (22) which is intended to come in contact with or close to a tank lower wall portion for sucking liquid from said tank or for returning liquid to said tank, characterized in that said at least one pipe (20, 24, 26) is arranged as a coil and has elastic properties such that the elastic coiled pipe tends to expand and such that the lower extremity of the elastic coiled pipe tends to extend downwardly

Description

Liquid supply device for a vehicle

Technical field

The invention pertains to the field of liquid supply systems for vehicles, especially for trucks. Such systems are used for supplying a liquid contained in a tank of said vehicle to a liquid-consuming system, such as fuel supply systems and urea supply systems.

Background art

The invention relates more precisely to a liquid supply device which is intended for fitting on an upper surface of a liquid-containing tank, said supply device comprising at least a supply head which is to be fitted on an upper surface of the tank, and, connected to the supply head, a liquid suction pipe having a lower extremity which is intended to come close to or in contact with a tank lower surface. Such a system may also have at least one auxiliary pipe for sucking liquid from said tank or for returning liquid to said tank.

Contrary to systems where the liquid is sucked from the lower surface of the tanks, for example through a hole in the lower surface of the tank or through a suction device which is inherently immersed in the tank and affixed to the lower surface of the tanks, such systems which are principally fitted on an upper surface of the tank, have to take into account possible variations in the distance between said upper and lower surfaces of the tank.

An example of such device is shown for example in document EP-0.532.427. In this document, the suction pipe has a length adjustable portion where the pipe side-wall is accordion-like. The accordion-like portion can expand or contract to vary the total length of the suction pipe. Nevertheless, due to its manufacture with a relatively rigid material, it is evident that the length-varying capacity of such a structure is quite limited, and it is indeed intended to adapt the length only to slight variations in height of a given tank, for example due to deformation of the tank under load, or due to production discrepancies. In document FR-2.583.684 is shown a device having a chimney section and a suction chamber which are connected by a telescopic rod. A metal spring is arranged around the telescopic rod to press the suction chamber downwardly against the lower tank surface. A suction pipe and a return pipe are provided in parallel to the telescopic rod. The pipes both exhibit a length adjustable portion where the pipe side-wall is accordion-like. This device is relatively complex because of the number of parts it requires, and it is also able to compensate only for very moderate height variation of the tank.

It is therefore an object to improve such liquid supply device.

Summary of the invention

According to one aspect of the invention, it is suggested a liquid supply device for a vehicle for supplying a liquid contained in a tank of said vehicle to a liquid-consuming system, said supply device being intended for fitting on an upper wall portion of a liquid- containing tank, said supply device comprising at least a supply head which is to be fitted on an upper wall portion of the tank, and, connected to the supply head, at least one pipe having a lower extremity which is intended to come in contact with or close to a tank lower wall portion for sucking liquid from said tank or for returning liquid to said tank, characterized in that said at least one pipe is arranged as a coil and has elastic properties such that the elastic coiled pipe tends to expand and such that the lower extremity of the elastic coiled pipe tends to extend downwardly. According to this aspect of the invention, the supply device requires a reduced number of parts.

In one embodiment of the invention, the elastic coiled pipe is a main suction pipe for sucking liquid from the tank

According to another aspect of the invention, it is suggested a liquid supply device, characterized in that the suction pipe is telescopic with at least an upper part connected to the supply head and a lower part which can slide with respect to said upper part. Preferably, the lower part of the telescopic suction pipe carries the lower extremity of the suction pipe independently from the upper part of the telescopic suction pipe. According to this aspect of the invention, the supply device can easily be designed to adapt to big discrepancies in fuel tanks heights in which it can be installed. It can be designed to adapt to tanks having largely varying nominal heights.

Other aspects of the invention will become apparent in the following detailed description

Description of figures Figures 1 and 2 are two schematic views representing one embodiment of a liquid supply device according to the invention installed in two tanks of different heights.

Figure 3 is a perspective view of an embodiment of a liquid supply device according to the invention.

Figure 4 is a perspective view of a second embodiment of a liquid supply device according to the invention.

Description of the invention

On figures 1 and 2 are represented two tanks 10, each having an upper wall portion 12 and a lower wall portion 14. A liquid supply device 16 according to the invention is intended to be at least partly received within the internal volume of both tanks. The liquid supply device 16 is intended to be affixed to the upper wall portion 12 of the tank and to extend within the tank so the lower extremity of a liquid suction pipe is in contact with the lower wall portion 14 or at least near said lower wall portion. Preferably, but not necessarily, the upper and wall portions 12, 14 will be respectively the uppermost and/or the lowermost wall portions of the tanks. In the drawings, it will be seen that these upper and lower wall portions are located vertically one over the other. Accordingly, the liquid supply device 16 depicted on those figures extends essentially vertically. Nevertheless, these surfaces are not necessarily so arranged, as they could also be offset horizontally one with the other. In such a case, the liquid supply device would extend essentially along an inclined direction compared to the vertical. Also, the upper and lower wall portions are shown in Figures 1 and 2 as being substantially horizontal, but the tanks could be arranged so that at least one of these surfaces is inclined with respect to said horizontal. For example, the upper wall portion of the tank, on which the liquid supply device is to be fitted, could be vertical, thus being an upper side surface of the tank. The difference between the tanks which are shown on figures 1 and 2 lies essentially in the distance H between their upper and lower wall portions between which the liquid fuel supply device extends. It will be seen that, thanks to the invention, a same liquid supply device can be used with both tanks.

The tanks shown in Figures 1 and 2 are fuel tanks pertaining to a fuel supply system of a vehicle, for supplying fuel mainly to an internal combustion engine of the vehicle. As will be seen, the fuel supply system can also supply other fuel-consuming systems of the vehicle such as a cabin heater. Nevertheless, the tanks could also pertain to other liquid supply systems of the vehicle. For example, the tanks could pertain to a urea precursor supply system for feeding urea precursor to an exhaust gases after-treatment system.

The liquid supply system to which the liquid supply device pertains can comprise, in addition to said device and to the above mentioned tank, one or several of the following items:

- a liquid pump for pumping liquid from said tank through said liquid supply device; - a main liquid feed conduit having a first part connecting the liquid supply device to the liquid pump, and a second part connecting the liquid pump to the main liquid consuming system;

- a main liquid return conduit for returning liquid from the main liquid consuming system to the tank through said liquid supply device; - a secondary liquid feed conduit connecting the liquid supply device to a secondary liquid consuming system;

- a secondary liquid return conduit for returning liquid from the secondary liquid consuming system to the tank through said liquid supply device;

- a pressure regulator, a flow meter, valves, etc...

The liquid supply device 16 represented on Figures 3 and 4 comprise a supply head 18 by which it is to be fitted on the tank 10. The supply head 18 may be fully external to the tank or could be at least partially received within the internal volume of the tank, thus being received through a corresponding hole in the upper wall portion 12. The supply head could also be entirely received inside the internal volume of the tank, thus being affixed to the lower surface of the upper wall portion. The supply head can be affixed to the upper wall portion by any suitable fixing means, including snap-on connecting means, screw, rivets, gluing, welding etc...

The liquid supply device according to the invention comprises a liquid suction pipe 20 which extends from the supply head into the internal volume of the tank. As stated above, when the liquid supply device is fitted on the tank, a lower extremity 22 of the liquid suction pipe 20 is intended to come in contact with or close to a tank lower wall portion.

In a first embodiment of the invention shown on figure 3, said supply device comprises at least one auxiliary pipe for sucking liquid from said tank or for returning liquid to said tank, and the auxiliary pipe has elastic properties and presses the lower extremity of the suction pipe downwardly. The auxiliary pipe, which extends inside the tank, can for example be a main liquid return pipe 24, a secondary liquid suction pipe 26 or a secondary liquid return pipe which can be connected to a corresponding conduit outside the tank through the supply head 18. Several auxiliary pipes having elastic properties can be used jointly to press the lower extremity of suction pipe downwardly. With this arrangement, the main liquid suction pipe can be a flexible pipe while the auxiliary pipe can be a semirigid pipe having elastic properties. Preferably, if the main suction pipe is flexible, the auxiliary pipe is connected to the main pipe near the lower extremity of the latter so that this lower extremity is effectively located in the tank near the lower wall portion thanks to the elasticity of the auxiliary pipe.

According to another aspect of the invention, which can be implemented independently from the one described above and which is illustrated in Figure 3, the main suction pipe 20 is telescopic with at least an upper part 28 connected to the supply head 18 and a lower part 30 which can slide with respect to said upper part. Preferably, the lower part 30 of the telescopic suction pipe 20 carries the lower extremity 22 of the suction pipe independently from the upper part of the telescopic suction pipe. In cases where the telescopic suction pipe 20 is installed substantially vertically in the tank, it can be sufficient to provide that the weight of the lower part of the telescopic pipe insures by the mere action of gravity that the telescopic pipe extends itself to the maximum permitted either by the depth of the tank of by the maximum length of the telescopic pipe.

Nevertheless, the telescopic pipe will preferably be fitted with an elastic device which acts on its lower part to press the lower extremity of the suction pipe downwardly. Such an elastic device can be a dedicated spring, for example a coiled metallic compression spring which is compressed between the upper and the lower parts of the telescopic pipe.

In a refined embedment of a liquid supply device according to the invention, as shown on Figure 3, the two aspects of the invention which are highlighted above are combined so that the main liquid suction pipe 20 is telescopic and that at least one auxiliary pipe 24, 26 having elastic properties presses the lower extremity of the suction pipe downwardly. Of course, the auxiliary pipe can be any of the pipes described above, and several pipes can be configured to elastically press the lower extremity 22 of the suction pipe downwardly. In this embodiment, at least one of said auxiliary pipes 24, 26 is arranged as a coil and has elastic properties such that the elastic coiled pipe tends to expand and such that the lower extremity of the elastic coiled pipe tends to extend downwardly.

As shown on Figure 3, the auxiliary pipe(s) 24, 26 can be coiled around the telescopic suction pipe 20 and can press on a surface of the lower part of the suction pipe downwardly. The auxiliary pipe 24, 26 can be a tube of plastic material. It can be open at its lower end, or anywhere along its length for sucking or returning liquid from/to the tank.

In a second embodiment of the invention, shown on Figure 4, the suction pipe 20 itself is arranged as a coil and has elastic properties such that the elastic coiled pipe tends to expand and such that the lower extremity of the elastic coiled pipe tends to extend downwardly. The suction pipe is here connected to the supply head 18 through its upper extremity, and its lower extremity will tend to reach the lower wall portion of the tank as the coil expands. In this example, the liquid supply device is not fitted with any auxiliary pipe. Nevertheless, if at least one such auxiliary pipe were present, it could advantageously also be formed as an elastic coil pipe.

In both embodiments having at least one coiled elastic pipe, the pipe can be coiled along a cylinder, as shown on the figures, with a substantially constant diameter of the coil along its length, or can be coiled as cone, with a varying diameter of the coil along its length. In such a case, the diameter of the cone can increase from its upper extremity to its lower extremity, or it can decrease from its upper extremity to its lower extremity.

Preferably, the lower extremity 22 of the main suction pipe 20 is fitted with a filter 32 for filtering the liquid which is sucked by the suction pipe. The filter can be external, i.e. surrounding the lower extremity of the pipe, as shown on the Figures. It can also be internal to the lower extremity of the pipe. The lower extremity of the main suction pipe can also be equipped with an anti-obstruction device for preventing the lower extremity of the pipe through which the liquid is to be sucked-in from becoming obstructed by the mere contact with the lower wall portion of the tank. If the lower extremity of the suction pipe is equipped with an external filter and/or with an anti-obstruction device, it can be provided that such filter and/or device is shared with the auxiliary pipe(s). According to a further refined embodiment of the invention, the liquid supply device comprises a sensor device 34 for evaluating the volume of liquid contained in the tank, based on an electromagnetic wave reflection sensor. Such a sensor will preferably be an ultrasonic sensor, although other equivalent sensors such as radars or lidars could be contemplated. More precisely the sensor can be used to evaluate the position of the surface of the liquid in the tank. For example, the sensor 34 is able to measure the distance toward the surface of the liquid contained in the tank. Knowing the geometry of the tank, it is then possible to evaluate the volume of the liquid contained in the tank at a given time. An example of such ultrasonic sensor device for evaluating the volume of liquid contained in the tank is described in document US-4.535.627.

Preferably the ultrasonic sensor 34 is located on the supply head. It can be connected to an electronic module (not shown) which can communicate with other electronic devices of the vehicle. The information communicated by the electronic module which is integrated on the supply head can be representative only of the distance measured by the ultrasonic sensor. In such a case, the conversion of this distance into a value indicative of the remaining volume of liquid will be computed by another electronic module, remote from the supply head. But preferably, the electronic module which is integrated in the supply head is able to compute the remaining volume so that the information which is communicated to the other electronic module(s) is directly indicative of the remaining volume. Such communication can be analog, but it will preferably be digital. Also, although this communication can be performed over a dedicated wire or set of wires, it is preferred that the communication is performed over a shared databus, such as a LIN-bus or a CAN-bus well known in the vehicle industry.

Since the fuel supply device according to the invention is designed to be used with different tanks, it will be necessary to be able to calibrate the electronic module to perform the right conversion from distance to volume. Such calibration can be performed externally when the liquid supply device is installed on a vehicle, or it can involve an auto-calibration procedure whereby the liquid supply device is able on its own to recognize the tank on which it is fitted and to retrieve a corresponding conversion algorithm.

In order to achieve an optimal accuracy of the remaining volume evaluation, it is preferable that the supply device comprises a temperature sensor, especially for taking into account the variations in the propagation of ultrasonic waves according to the temperature of the medium in which such waves propagate. Such temperature sensor will optimally be located on the supply head and will be used to measure the temperature of the gas which is trapped in the tank above the liquid contained in the tank.

The liquid supply device according to the invention may be fitted in all sorts of vehicles, most particularly in commercial vehicles, including trucks and construction equipment machines such as haulers, loaders, excavators, and road machinery

Thanks to the invention, a liquid supply device is obtained which can be used in vehicle tanks having very different heights, while still be very easy and cheap to produce, with a minimum number of parts.

Claims

1. Liquid supply device for a vehicle for supplying a liquid contained in a tank (10) of said vehicle to a liquid-consuming system, said supply device (16) being intended for fitting on an upper wall portion (12) of a liquid-containing tank (10), said supply device (16) comprising at least a supply head (18) which is to be fitted on an upper wall portion (12) of the tank, and, connected to the supply head, at least one pipe (20, 24, 26) having a lower extremity (22) which is intended to come in contact with or close to a tank lower wall portion (14) for sucking liquid from said tank or for returning liquid to said tank, characterized in that said at least one pipe (20, 24, 26) is arranged as a coil and has elastic properties such that the elastic coiled pipe tends to expand and such that the lower extremity of the elastic coiled pipe tends to extend downwardly.

2. Liquid supply device according to claim 1, characterized in that the elastic coiled pipe is a main suction pipe (20) for sucking liquid from the tank.

3. Liquid supply device according to claim 1, characterized in that it comprises a main suction pipe (20) for sucking liquid from the tank and at least one auxiliary pipe (24, 26) for sucking liquid from said tank or for returning liquid to said tank, in that said at least one auxiliary pipe (24, 26) forms said elastic coiled pipe, and in that said elastic coiled pipe presses the lower extremity of the suction pipe (20) downwardly.

4. Liquid supply device according to claim 3, characterized in that the main suction pipe (20) is also an elastic coiled pipe which tends to expand such that the lower extremity of the elastic coiled pipe tends to extend downwardly.

5. Liquid supply device according to claim 3, characterized in that the suction pipe (20) is telescopic with at least an upper part (28) connected to the supply head (18) and a lower part (30) which can slide with respect to said upper part.

6. Liquid supply device according to claim 5, characterized in that the lower part (30) of the telescopic suction pipe (20) carries the lower extremity (22) of the suction pipe (20) independently from the upper part (28) of the telescopic suction pipe (20).

7. Liquid supply device according to claims 5 or 6, characterized in that the auxiliary pipe (24, 26) is coiled around the telescopic suction pipe (20) and presses the lower part of the suction pipe (20) downwardly.

8. Liquid supply device according to any of claims 2 to 7, characterized in that the lower extremity (22) of the suction pipe (20) is fitted with a filter for filtering (32) the liquid which is sucked by the suction pipe.

9. Liquid supply device according to any preceding claims, characterized in that the supply device (16) comprises an electromagnetic wave reflection sensor device (34) for evaluating the volume of liquid contained in the tank.

10. Liquid supply device according to claim 9, characterized in that the sensor (34) is located on the supply head (18).

11. Liquid supply device according to claims 9 or 10, characterized in that the sensor (34) is able to measure the distance towards the surface of the liquid contained in the tank.

12. Liquid supply device according to any preceding claims, characterized in that the supply device (16) comprises a temperature sensor.

13. Liquid supply device according to claim 9, characterized in that the temperature sensor is located on the supply head (18).

14. Liquid supply device according to any preceding claim, characterized in that the supply device comprises at least a second auxiliary pipe (26, 24) for sucking liquid from said tank (10) or for returning liquid to said tank (10), characterized in that the second auxiliary pipe (26, 24) is arranged as a coil and has elastic properties such that the elastic coiled pipe tends to expand and such that the lower extremity of the elastic coiled pipe tends to extend downwardly.

15. Liquid supply device according to any claim 9 to 13, characterized in that the supply head (18) comprises an electronic module which is connected to the sensor (34) and which has a digital output for its connection to a databus.