Tank system with a valve in the form of a pendulum system

Description

TECHNICAL FIELD

[0001] The present invention relates to a tank system comprising a tank containing a liquid and a valve in the form of a pendulum system, as well as to an aircraft comprising such a tank system. STATE OF THE PRIOR ART

[0002] In an aircraft, fuel such as kerosene or dihydrogen is stored in a tank fixed in the aircraft. To channel the fuel from the tank to an engine, the aircraft has at the bottom of the tank, a drain pipe fluidically connected to a distribution pipe itself fluidically connected to the engine and to which a pump is connected. The drain pipe has several drain holes that allow the flow of fuel to the drain pipe and the fuel thus flows from the tank to the engine.

[0003] During the various phases of flight, the aircraft does not remain horizontal and may assume tilted positions, particularly during takeoff, landing and altitude changes. When the aircraft is in such a tilted position, the liquid fuel repositions itself under the effect of gravity, and depending on the quantity of fuel remaining in the tank, one or more drain holes may be located outside the fuel and the pump then sucks, at least in part, gas present in the tank.

[0004] To avoid such a problem, valves have been developed which include, for example, a movable plug subject to gravity which closes the drain hole when the aircraft takes a tilted position.

[0005] Although such systems give good results, there is a need to find more robust systems, in particular those which ensure that at least one valve is always open.

[0006] GB 466 335 A, according to its abstract, discloses a fuel tank having two outlets leading to a common pipe. Each outlet has a valve mounted on a pivoting beam carrying floating elements arranged so that the beam is moved by the floating elements to close the outlet at which the fuel depth has been reduced. STATEMENT OF THE INVENTION

[0007] An object of the present invention is to provide an aircraft tank system comprising a tank containing a liquid and a valve in the form of a pendulum system which ensures the closure of a drain port when the aircraft assumes tilted positions.

[0008] For this purpose, a tank system is proposed for an aircraft having a longitudinal direction, said tank system comprising: a tank intended to contain a liquid, a drain pipe which is housed and fixed in the tank in the lower part thereof and which extends parallel to the longitudinal direction and has at each end a drain orifice, for each drain orifice, a funnel secured to the drain pipe, where the axis of the funnel is parallel to the longitudinal direction and where the top of the funnel opens into the drain orifice, where the funnel has a wall crossed by at least one window, a body mounted movable in translation parallel to the longitudinal direction, for each funnel, a plug secured to the body and arranged movable inside said funnel alternately between an open position in which the plug does not block either the windows of the funnel or the drain orifice and a closed position in which the plug blocks at least the drain orifice,and an arm, a first end of which is mounted articulated to the tank above the body and a second end of which is mounted articulated on the body by means of a connection combining a pivot connection around an axis perpendicular to the longitudinal and horizontal direction and a sliding connection perpendicular to the longitudinal direction in a plane perpendicular to said axis.

[0009] Such a tank system is particularly robust in operation thanks to the pendulum effect of the arm and ensures that at least one of the ports is always open regardless of the position of the aircraft.

[0010] Advantageously, the reservoir system includes a weight which is attached to the arm as close as possible to its second end.

[0011] Advantageously, each funnel is truncated-conical and each stopper is truncated-conical in shape.

[0012] Advantageously, each funnel extends opposite the drain orifice by a cylinder whose axis is parallel to the longitudinal direction, each plug extends opposite the drain orifice by a cylinder whose axis is parallel to the longitudinal direction, and the cylinders of the plugs slide in the cylinders of the funnels. The invention also proposes an aircraft comprising a distribution pipe, a pump mounted on the distribution pipe and a tank system according to one of the preceding variants where the drain pipe is fluidically connected to the distribution pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above-mentioned and other features of the invention will become more clearly apparent from the following description of an exemplary embodiment, said description being given in relation to the accompanying drawings, among which: Fig. 1 is a side view of an aircraft according to the invention, Fig. 2 is a schematic representation of a tank system according to the invention in a horizontal flight position, and Fig. 3 is a schematic representation of the reservoir system of the Fig. 2 in a tilted position of the aircraft. DETAILED PRESENTATION OF EMBODIMENT METHODS

[0014] In the following description, terms relating to a position are taken with reference to an aircraft in a normal flight position, that is to say as it is represented on the Fig. 1 .

[0015] In the following description, and by convention, we call X the longitudinal direction of the aircraft, we call Y the transverse direction which is horizontal when the aircraft is on the ground, and Z the vertical direction which is vertical when the aircraft is on the ground, these three directions X, Y and Z being orthogonal to each other.

[0016] There Fig. 1 shows an aircraft 100 which comprises a fuselage 102 on each side of which is fixed a wing 104 which carries at least one engine 106 operating with fuel such as kerosene or dihydrogen. In the embodiment of the invention presented in the Fig. 1 , the 106 engine is a propeller engine, but any other type of engine is possible.

[0017] Arrow 107 indicates the forward direction of aircraft 100.

[0018] The aircraft 100 comprises a tank system 150 according to the invention, and which comprises a tank 152 in which the fuel is stored in liquid form. In the embodiment of the invention, the tank 152 is arranged at the rear of the fuselage 102, but a different positioning is possible.

[0019] The aircraft 100 also includes a fuel system 154 that provides the fluid connection between the tank 152 and each engine 106. The fuel system 154 includes, among other things, a distribution line 158 and a pump 156 mounted on the distribution line 158 and arranged to pump fuel from the tank 152 and send it to each engine 106.

[0020] There Fig. 2 shows the tank system 150 when the aircraft 100 is in a horizontal position, and the Fig. 3 shows the tank system 150 when the aircraft 100 is in a tilted position which may be due for example to a takeoff or a climb in altitude. In the case of a landing or a descent in altitude, the positioning is reversed and the longitudinal direction X points downwards.

[0021] In the embodiment of the invention shown in the Figs., the reservoir 152 has a cylindrical shape whose axis is oriented parallel to the longitudinal direction X, but a different shape is also possible, for example parallelepiped.

[0022] The tank system 150 comprises a drain pipe 160 which is housed and fixed in the tank 152 in the lower part thereof so as to immerse in the fuel 50. The drain pipe 160 is fluidically connected to the distribution pipe 158, here by an elbow in the middle of the drain pipe 160.

[0023] The drain pipe 160 extends parallel to the longitudinal direction X and has a drain orifice 162 at each end.

[0024] The tank system 150 comprises, for each drain orifice 162, a funnel 164 secured to the drain pipe 160 where the axis of the funnel 164 is parallel to the longitudinal direction X and where the top of the funnel 164 opens into the drain orifice 162. Each funnel 164 is here truncated-conical and points towards the drain orifice 162.

[0025] The funnel 164 is made up of walls, at least one of which is crossed by a window 166 which ensures fluid communication between the exterior and the interior of the funnel 164. Thus, the fuel 50 is sucked in by the pump 156 and flows through each window 166 inside the funnel 164 to reach the drain pipe 160, then the distribution pipe 158.

[0026] The tank system 150 comprises a body 172 which is rigid and mounted to move in translation parallel to the longitudinal direction X.

[0027] The tank system 150 also comprises, for each funnel 164, a plug 170 secured to the body 172 and which therefore moves with it and is thus slidably mounted inside the funnel 164, alternately between an open position in which the plug 170 does not block either the windows 166 of the funnel 164 or the drain orifice 162 and a closed position in which the plug 170 blocks at least the drain orifice 162 and, incidentally, the windows 166 of the funnel 164. The shape of each plug 170 is adapted to the shape of the funnel 164 to ensure sealing at the drain orifice 162. Here, each plug 170 is of truncated-conical shape and points towards the drain orifice 162.

[0028] In the open position, fuel 50 flows to the engine 106 and in the closed position, the drain port 162 is plugged and nothing can flow through it.

[0029] The tank system 150 comprises an arm 174, a first end 174a of which is mounted articulated to the tank 152 above the body 172, and here in the upper part of the tank 152. The first end 174a is generally in the middle of the body 172 when the aircraft 100 is in a horizontal position. The arm 174 is housed inside the tank 152.

[0030] In the embodiment of the invention presented here, the articulation is here a rotation around a first axis R1 parallel to the transverse direction Y and it takes here the form of a yoke secured to the reservoir 152 and an axis parallel to the first axis R1 which is mounted in the yoke and constitutes the first end 174a.

[0031] The arm 174 comprises a second end 174b which is mounted articulated on the body 172 by means of a connection combining a pivot connection around a second axis R2 perpendicular to the longitudinal direction X and horizontal, that is to say here in the transverse direction Y and a sliding connection perpendicular to the longitudinal direction X in a plane XZ perpendicular to the second axis R2, that is to say here in the vertical direction Z. In the embodiment of the invention presented here, the articulation of the second end 174b takes the form of a yoke secured to the body 172 whose holes 173 are oblong and where the major axis constitutes the direction of the sliding connection, and an axis parallel to the second axis R2 which is mounted in the yoke and constitutes the second end 174b.

[0032] Arm 174 thus acts like a pendulum.

[0033] Thus, when the aircraft 100 takes a tilted position as in the Fig. 3 , the arm 174 pivots around the first axis R1 under the effect of gravity, driving the body 172 in translation parallel to the longitudinal direction X. While moving, the body 172 drives the plugs 170 and the highest plug 170 closes the drain orifice 162 which is the highest and therefore potentially outside the fuel 50 and there is then no gas present in the tank 152 to enter the drain pipe 160 through this drain orifice 162, while the other drain orifice 162 remains immersed in the fuel 50 and supplies the pump 156 with fuel 50 and there is thus always a drain orifice 162 open and immersed in the fuel 50. When the body 172 moves, the second end 174b is free to pivot around the second axis R2 and to move inside the oblong holes 173.

[0034] To facilitate the rotation of the arm 174 under the effect of gravity, the arm 174 is equipped with a weight 176 which is fixed to the arm 174 as close as possible to its second end 174b.

[0035] In the embodiment of the invention presented on the Figs. 2 And 3 , each funnel 164 of truncated-conical shape extends opposite the drain orifice 162 by a cylinder 178 whose axis is parallel to the longitudinal direction X. In the same way, each plug 170 extends opposite the drain orifice 162 by a cylinder 180 whose axis is parallel to the longitudinal direction X. The translational guidance of the body 172 and the plugs 170 is then ensured here by the cylinders 180 of the plugs 170 which slide in the cylinders 178 of the funnels 164.

[0036] But according to another embodiment, the translational guidance can be ensured by the guidance of the body 172 relative to a fixed element of the reservoir 152, such as for example any translational guidance system known to those skilled in the art.

[0037] In the embodiment of the invention presented here, the windows 166 are made in the wall of the cylinder 178, but they can be made in the frusto-conical wall.

[0038] Although the invention has been described on the basis of a fuel tank, it can be applied to any tank containing a liquid.

Claims

1. Tank system (150) for an aircraft (100) having a longitudinal direction (X), said tank system (150) comprising: - a tank (152) intended to contain a liquid, - a drainage line (160) that is housed and fixed in the bottom part of the tank (152), extends parallel to the longitudinal direction (X), and has a drainage port (162) at each end, - for each drainage port (162), a funnel (164) secured to the drainage line (160), wherein the axis of the funnel (164) is parallel to the longitudinal direction (X) and wherein the top of the funnel (164) opens into the drainage port (162), wherein the funnel (164) has a wall, through which at least one window (166) passes, - a body (172) mounted to be able to move in translation parallel to the longitudinal direction (X), - for each funnel (164), a plug (170) that is secured to the body (172) and arranged to be able to move inside said funnel (164) alternately between an open position in which the plug (170) blocks off neither the windows (166) in the funnel (164) nor the drainage port (162) and a closed position in which the plug (170) blocks off at least the drainage port (162), and - an arm (174), a first end (174a) of which is mounted in an articulated manner to the tank (152) above the body (172) and a second end (174b) of which is mounted in an articulated manner on the body (172) via a connection combining a connection that pivots about an axis (R2) perpendicular to the longitudinal direction (X) and horizontal and a connection that slides perpendicular to the longitudinal direction (X) in a plane (XZ) perpendicular to said axis (R2).

2. Tank system (150) according to Claim 1, characterized in that it comprises a weight (176), which is fixed to the arm (174) as close as possible to the second end (174b) thereof.

3. Tank system (150) according to either of Claims 1 and 2, characterized in that each funnel (164) is frustoconical and in that each plug (170) has a frustoconical shape.

4. Tank system (150) according to Claim 3, characterized in that each funnel (164) is extended at the end facing away from the drainage port (162) by a cylinder (178), the axis of which is parallel to the longitudinal direction (X), in that each plug (170) is extended at the end facing away from the drainage port (162) by a cylinder (180), the axis of which is parallel to the longitudinal direction (X), and in that the cylinders (180) of the plugs (170) slide within the cylinders (178) of the funnels (164).

5. Aircraft (100) comprising a distribution line (158), a pump (156) mounted on the distribution line (158) and a tank system (150) according to one of the preceding claims, wherein the drainage line (160) is fluidically connected to the distribution line (158).