SE0950318A1 - Fuel systems, as well as vehicles comprising said fuel system - Google Patents

Description

10 15 20 25 30 2 in the venturi before being discharged into the smaller container / tank. On this way the fuel level is kept constantly high in the smaller one the tank / tank and a reliable continuous flow of fuel from the container / tank of the engine can be secured.

However, this type of fuel system requires a relatively large and continuous fl waste of recycled fuel to generate the necessary the transfer of fuel from the main tank to the smaller one the container / tank, and in the event of an interruption or too little fl fate sufficient fuel transfer will not be possible.

There is thus a need for a more reliable transfer of fuel from main tank for the smaller container / tank.

Summary of the invention The present invention has for its object to eliminate the above problem. The purpose is achieved through a fuel system according to it independent patent claim.

The problems described above are solved by using the venturi instead to be driven by the varying fl fate of return fuel from the engine is driven using compressed air.

Another advantage of the present invention is that it is a lot easy to modify, and thereby improve, existing fuel system then only a few components to lead compressed air to the venturi tube needs to be added to the existing system and thereby obtain the improved system of the invention.

A further advantage of the fuel system according to the invention is that it does not result in any temperature increase of the fuel in the secondary tank which inevitably happens in existing solutions where heated recycled fuel 10 15 20 25 30 3 from the engine is used to drive the fuel transfer from the main tank to secondary tank.

In one embodiment of the invention, the secondary tank is provided with a vent valve to avoid overpressure in the tank. This embodiment results in a system with increased reliability then none there is a risk of undesired overpressure in the secondary tank.

In one embodiment of the invention, it is in a suitable location along it the second line through which fuel / air is transported arranged a deaeration unit where at least part of the air is supplied the venturi and thereby currents in the line are diverted from the fuel.

This embodiment can be used in combination with the previous one the solution for deaeration or as a separate solution to avoid overpressure in the smaller tank. This embodiment also has the advantage that the risk of foaming in the smaller tank is then reduced at least some of the air in the fuel / air mixture is removed before it flows into the secondary tank.

In one embodiment of the invention, a compressed air hose leads the air the venturi and along the compressed air hose a valve is provided with which air flow through the compressed air hose can be controlled. This embodiment thus makes it possible to control the amount of fuel which transferred from the main tank to the secondary tank.

The venturi has a section with reduced cross-sectional area and that it first management joins this section. This embodiment results in a fuel system that is easy to manufacture, assemble and place in a vehicle.

The invention also relates to a vehicle comprising any of the fuel systems described above. 10 15 20 25 30 In one embodiment, compressed air from an existing system in the vehicle is led to fuel system venturi. This embodiment means that nothing separate additional arrangements for supplying compressed air to the fuel system needs to be installed in the vehicle.

In one embodiment, the compressed air to the vehicle's fuel system is led from one brake system comprising a compressor for the venturi. This is a advantageous embodiment as the vehicle does not need to be provided with additional systems without an existing system in the vehicle can be used.

Short figure description The invention is explained in more detail below with reference to it embodiment of the invention shown in the drawing figures, where: Figure 1 schematically shows the fuel system according to the invention.

Figure 2 schematically shows an embodiment of a venturi.

Detailed description of the invention Figure 1 shows an embodiment of the fuel system 10 defined by patent claims. The fuel system is intended to be used to continuously and reliably supply an internal combustion engine 11 with the desired amount of fuel. The fuel system includes a main tank 12 in which fuel is filled and stored. The main tank 12 has a volume which provides the desired range as well as satisfactory refueling intervals.

The volume is thus adjusted based on what the internal combustion engine 11 is installed in for type of vehicle, as well as engine 1 1 fuel consumption.

The main tank 12 has a suitable geometric shape based on what is available the space, as well as the desired volume. 10 15 20 25 30 5 If large fuel volumes are required or desired, alternatively if available space for the main tank 12 is limited, the vehicle can include fl your interconnected fuel tanks to thereby increase the total volume as well as enable better use of available space.

The fuel system also includes a secondary tank 13. Fuel is transferred from the main tank 12, or tanks, continuously to the secondary tank 13 so that the fuel level in this tank during use of the vehicle always kept at a higher level than the level in the main tank 12. This is to ensure that there is always enough fuel in the secondary tank 13 in order to continuously meet the engine's 1 1 periodically great need of fuel. The secondary tank 13 is in the embodiment shown in Figure 1 of an integrated, separated from the main tank 12, in the main tank 12, integrated space. The wall 14 delimiting the secondary tank 13 from the main tank 12 has an opening 15 so that when the desired fuel level achieved in the secondary tank 13, i.e. when the fuel level reaches the lower edge of the opening 15, the fuel is drained in the secondary tank 13 back to the main tank 12 through the opening 15. This is important for to avoid overfilling of fuel in the secondary tank 13 when this can result in leakage from connections and the like in the secondary tank 13.

However, the secondary tank can alternatively consist of a separate tank placed separated from the main tank. The secondary thought must then be provided with some kind of drainage back to the main tank in order to avoid overfilling the secondary tank.

Both the main tank 12 and the secondary tank 13 may have different geometric shapes depending on the available space in the imaginary the vehicle. However, the main tank 12 preferably has a shape such as facilitates as complete emptying of the main tank 12 as possible while the shape of the secondary tank 13 is suitably such that the fuel in 10 15 20 25 30 6 the tank is moved to the area where the fuel is transferred to the engine 1 1, for example by having a bottom with surfaces sloping towards this area so that the fuel accumulates at the desired location in the secondary tank 13.

The fuel is transferred from the main tank 12 to the secondary tank 13 via a first conduit 16, one end 17 of which opens near the main tank 12 bottom 18 to ensure that so much of the fuel in the main tank 12 as possible can be utilized and transferred to the secondary tank 13.

For transferring fuel from the main tank 12 to the secondary tank 13 a venturi 20 is used. The venturi 20 includes, as shown in FIG 2, a substantially straight through passage 21 which has a section 22 with significantly reduced cross-sectional area. The reduced area then gives a fl uid flows through the passage 21 giving rise to an increase flow rate through section 22 which in turn generates a suction force in the first line 16 (figure 1) whose second end 19 is connected to section 22 with reduced cross-sectional area. The generated suction power in the first line 16 causes the fuel to move from the main tank 12 to the venturi 20 where it is mixed with fl uiden, i in this case air, which flows through the passage 2 1 and further via a second line 23 which opens into the secondary tank 13.

In the fuel system 10 shown in Figure 1, pressurized air is fed from a compressor 32 to the venturi 20 via a compressed air hose 24. The fuel from the main tank 12 is thus mixed with the pressurized air in the passage 21 of the venturi tube 20 and the fuel / air mixture are led to the secondary tank 13 via the second line 23.

The air in the fuel must be separated from the fuel before the fuel is transferred to the motor 11 to ensure the desired function of the motor 1 1. This can be done either in the secondary tank 13 which is provided with a vent valve (not shown) to avoid overpressure in the tank then 10 15 20 25 30 7 overpressure in the tank would entail great risks of accidents because Significant amounts of air flow along with the fuel to the tank.

Deaeration can alternatively take place with the aid of a deaeration unit 30 which is placed in a suitable place along the second conduit 23 for to separate as much air as possible from the fuel before it reaches the secondary idea 13. A combination of these two solutions is that prefer even if they give the desired effect individually. The deaeration unit 30 includes an fi lter which separates the air from the fuel.

Fuel is finally fed from the secondary tank 13 to the internal combustion engine 1 1 via a fuel line 25, one end 26 of which is suitably located near the bottom 27 of the secondary tank 13 while the other end is connected to the motor 1 1.

The fuel systems 10 shown in Figures 1 and 2 also include a valve 31 arranged in a suitable place along the compressed air line 24. The valve 31 makes it possible to control the compressed air flow to the venturi 20, and thus also the amount of fuel transferred from the main tank 12 to the secondary tank 13. The control of the valve 31 is preferably performed in relation, for example, current throttle for the engine when it affects engine fuel consumption.

The fuel system 10 according to the invention is suitably arranged in one vehicles, such as a truck. Main tank 12, or main tanks, are then arranged in suitable places in the vehicle. Many vehicles include one, or fl era, compressed air systems in which some of the functions of these vehicles are operated with compressed air generated by a motor compressor 32. An example of pneumatic systems are the braking system 33 on trucks. Compressed air can then led from this existing system to the venturi tube 20 and thereby be used for the desired transfer of the fuel from main tank 12 to the secondary tank 13. 8 The invention has been described above on the basis of a preferred embodiment however, a number of modifications are possible: - The specific design of the venturi can be varied to suit for certain specific conditions; 5 - The design of thoughts in terms of form and mutuality size ratio can be varied and adapted based on the vehicle which the system is used in and the desired properties of the system.

Pressurized gases other than air can be used. 10 Although the invention has been described on the basis of some examples embodiments, the invention is not limited to these but defined on the basis of the appended claims.

Claims (4)

10 15 20 25 30 PATENT REQUIREMENTS A fuel system (10) intended to supply a combustion engine (11) with fuel, the system comprising: - at least one main tank (12) intended to accommodate fuel; - a secondary tank (13) to which fuel is transferred from the main tank (12) and from which fuel is led via a fuel hose (25) to the internal combustion engine (1 1); a venturi (20) intended for transferring fuel from the main tank (12) to the secondary tank (13), the fuel system being characterized in that the transfer of fuel from the main tank (12) to the secondary tank (13) is obtained by passing compressed air through the venturi (20) and thereby generating a suction force in a first conduit (16) one end (17) of which is located in the main tank (12) and the second connected to the venturi (20) so that the fuel in the main tank is sucked through the first conduit (16) to the venturi where mixed with the compressed air and led to the secondary tank (13) via a second line (23). Fuel system according to claim 1, characterized in that the secondary tank (13) is either an integral part of the main tank (12), or a separate tank placed separately from the main tank (12). Fuel system according to claim 1 or 2, characterized in that the secondary tank (13) is provided with a vent valve to avoid overpressure in the tank. Fuel system according to one of the preceding claims, characterized in that a venting unit (30) is arranged in a suitable place along the second line (23), where at least a part of the air flowing in the line (23) is diverted from the fuel. 10 15 20 10. Fuel system according to one of the preceding claims, characterized in that a compressed air hose (24) conducts compressed air from a compressor (32) to the venturi (20) and that a valve (31) is arranged along the compressed air hose (24) with which air flows through the compressed air hose (24). ) can be controlled, and thereby also control the transfer of the amount of fuel from the main tank (12) to the secondary tank (13). . Fuel system according to one of the preceding claims, characterized in that the venturi tube (20) has a section (22) with a reduced cross-sectional area and that the first line (16) connects to this section (22). . Vehicle comprising a fuel system according to any one of claims 1 - 6.. Vehicle according to claim 7, characterized in that the compressed air is led from an existing system in the vehicle to the fuel system (10). . Vehicle according to claim 8, characterized in that the compressed air to the fuel system (10) is led from a braking system (33) comprising a compressor (32) to the venturi tube (20).