WO2007036698A1

WO2007036698A1 - Valve

Info

Publication number: WO2007036698A1
Application number: PCT/GB2006/003517
Authority: WO
Inventors: Matthew King; Brian Johnson; David Lowes
Original assignee: First Inertia Switch Limited
Priority date: 2005-09-27
Filing date: 2006-09-22
Publication date: 2007-04-05
Also published as: GB0519657D0; GB2430478A

Abstract

A cut-off valve for stopping flow of a fluid comprises a valve body in which is defined a fuel flow passage (12) between an inlet (2) and an outlet (4). A valve member (6), which is of paramagnetic material is moveable along the passage between a first position (121) allowing fluid to flow from the inlet to the outlet, and a second position (122) in which the valve member blocks the outlet to stop flow of fluid. First magnetic means (10) are provided for holding the valve member in the first position, and second magnetic means (8) are provided for holding the valve member in the second position.

Description

VALVE

The present invention relates to a valve. Embodiments of the invention relate to a cut-off valve for stopping flow of a fluid, for example fuel of a vehicle.

Currently, fuel cut-off in the event of an automobile crash is usually accomplished by having a mechanical inertia device trigger an electrical switch to isolate an electric fuel pump. However, in diesel engine vehicles the fuel pump is typically a mechanical pump which cannot be de-activated in that way. Also for petrol engines, even if the fuel pump is de-activated, fuel remaining in the tank is often pressurised and may continue to leak if the fuel pipe is severed in an accident. A previous proposal to mechanically shut-off an automobile fuel supply in the event of a roll-over or crash utilises a steel ball, which is displaced from its rest position by achievement of either a predetermined roll angle or rate of horizontal acceleration, to operate a trigger mechanism and thereby release the energy stored in a spring to close a valve. The present invention provides a cut-off valve for stopping flow of a fluid, the valve comprising a valve body in which is defined a fuel flow passage between an inlet and an outlet, a valve member, which is of magnetic material, moveable along the passage between a first position allowing fluid to flow from the inlet to the outlet, and a second position in which the valve member blocks the outlet to stop flow of fluid, first magnetic means for holding the valve member in the first position, and second magnetic means for holding the valve member in the second position. In examples of use of the invention, the valve is oriented so the fuel flow passage extends parallel to the centre line of the vehicle.

In one example, the valve member is the only moving part. In an accident for example, the inertia of the valve member acting in the direction from the first position to the second position releases the member from the magnetic force holding it at first position. The member moves to the second position where it is latched by the magnetic force at the second position. There the valve member blocks flow of fluid through the outlet. Any fuel pressure also pushes the member from the first position to the second position. In another example, the valve body has an outer surface about the said passage between the first and second positions, and an inertial mass moveable on said outer surface between the first and second positions, the inertial mass including at least one permanent magnet, the said first magnetic means comprising magnetic material at the first position which, when the inertial mass is at the first position completes, with the valve member and the said at least one permanent magnet, a magnetic circuit which holds the valve member at the first position, and the second magnetic means comprises magnetic material at the second position which, when the inertial mass is at the second position completes, with the valve member and the said at least one permanent magnet, a magnetic circuit which holds the valve member at the second position.

The valve when mounted parallel to the centre line of the vehicle will function in response to inertial events having at least a component of sufficient magnitude parallel to the centre line to release the valve member from the first position. For a better understanding of the present invention, reference will now be made by way of example to the accompanying drawings in which:

Figures 1 to 3 are schematic illustrations of a first embodiment of a fuel cut-off valve in accordance with the present invention, with Figures 2 and 3 being depicted in partial cross-section; Figures 4 to 7 are schematic illustrations some in partial cross section of a second example of the present invention; and

Figures 8 to 11 are schematic illustrations some in partial cross section of a third example of the present invention.

In the examples of Figure 1 to 11, the valve comprises a valve body in which a passage 12 contains a valve member e.g. a ball bearing 6 of paramagnetic material, such as stainless steel. The valve member 6 is held in an initial position by a permanent magnet 10, referred to as a holding magnet. The valve is triggered by a force having at least a component acting in the direction of the passage 12 so that the member 6 is freed from the holding magnet 10 at the initial position and moves from the initial position to a position in which it blocks fuel flow. This triggering is referred to hereinafter as an inertial event. Referring to Figures 1 to 3, a fuel cut-off valve has an inlet pipe 21 leading to an inlet 2 of a fuel flow passage 12 having an outlet 4 leading into an outlet pipe 41. The inlet and outlet pipes allow the valve to be fitted in a fuel line. In the example of Figures 1 to 3, the passage contains a ball bearing 6 of paramagnetic material, e.g. ferrous material. The passage 12 has a diameter D slightly greater than the diameter of the ball 6. The passage has a length of about 3 diameters of the ball 6 between one hemispherical end 121 of the passage and the other hemispherical end 122. The inlet 2 is between the ends 121 and 122 and is smaller than the ball 6, A permanent magnet 10 is at the end 121 to hold the ball bearing 6 at the end 121. If an iπertial event occurs, the inertia of the ball breaks the magnetic force holding it at the end 121 and the ball moves along the passage to the other end 122 where it is held by the magnetic force of another permanent magnet 8, referred to herein as the catch magnet. The catch magnet 8 is in the form of a ring in a fixed position around the outlet 4 in the example of Figures 1 to 3. However, it may be two or more individual permanent magnets fixed around the outlet 4 or any other suitable configuration. The outlet 4 is smaller than the ball. The ball 6 mates with a corresponding sealing surface around the outlet 4 to block the outlet. The pressure of the fuel in the pipe may also propel the ball from the end 121 to the outlet end 122 once the ball is released from the magnet 10 at the end 121. Thus in normal operation, the ball is retained in place by holding magnet 10 to allow fuel to flow freely through the valve. In particular, the ball is located against surface 121, thereby providing an unobstructed path between the fuel inlet 2 and the fuel outlet 4. This location of the ball is shown in Figure 2.

The fuel cut-off valve is triggered by an inertial event. For example, the inertia of the ball 6 in a frontal impact can overcome the magnetic holding force of the holding magnet 10, whereby the ball is thrown towards the catch magnet 8. The catch magnet holds the ball in position to block the fuel flow. In particular, the ball is held by catch magnet against, and thereby closing, fuel outlet 4. This location of the ball is shown in Figure^' 3. After the fuel cut off valve has been triggered so that the ball blocks the outlet, the valve may be reset. As shown in Figure 2, the valve may be reset by an external permanent magnet 26 which is used to drag the ball 6 from the outlet end 122 back to the end 121.

As shown in Figure 1, the material of the valve body may be transparent or translucent in the region 18 of the outlet 4 to provide a visible indication that the ball 6 is at the outlet when the valve has been triggered. For example, the valve may be provided with a transparent cap, so that the ball is visible through this cap after triggering.

Another example of the valve, as shown in Figures 4 to 7, is similar to that of the example of Figures 1 to 3. Figures 4 to 7 use the same reference numerals as Figures 1 to 3 and the valve has basically the same structure and operates in basically the same way. Figure 5 shows the ball 6 held in the untriggered position by the magnet 10 (in this case a disc magnet retained in the device by a sealing plug 49).

Figure 6 shows the ball in the triggered position held by the magnet 8. Again, it is assumed here that a frontal impact increases the inertia of the ball to overcome the holding force of disc magnet 10 and to throw the ball forward to where it is attracted to and retained by ring magnet 8 so as to block off fuel flow through the outlet pipe.

The valve of Figures 4 to 7 differs from that of Figures 1 to 3 mainly as follows. Instead of the fixed magnet or magnets 8 around the outlet 4, the magnet or magnets 8 are housed in a slide 14 which slides on a support surface 16 between a position adjacent the outlet 4 as shown in Figure 6, at which it holds the ball 6 at the outlet, to a release position spaced away from the outlet as shown in Figure 7 and defined by a stop 161.

In the position shown in Figure 6, the ball 6 blocks the outlet 4 and is held there by the magnet or magnets 8. Moving the magnet(s) 8 away from the outlet moves the ring magnet 8 out of reach of the ball 6. The ball 6 is therefore released from magnet 8, and can then be returned to the disk magnet 10, either by gravity, if the valve is or can be suitably inclined, or by use of an external magnet 26, as described above. Figure 7 illustrates the ball 6 returning to the untriggered position after such release. To prevent the magnet(s) 8 and slide moving in response to an inertial event, a lock is provided to lock the slide 14 in the position shown in Figures 4 and 5. The lock may be a latch 141 or a screw thread on the slide and a corresponding screw thread on the valve body adjacent the outlet 4. After the valve has been triggered, and the ball 6 subsequently released, the reset collar is now slid back and locked into the appropriate position.

It will be noted that in Figure 5, the initial position end 121 is not hemispherical. Instead a small recess is provided to locate the ball 6 near to the magnet 10.

Yet another example is shown in Figures 8 to 1 1. In this example the passage 12 extends between the inlet 2 and the outlet 4. The ball is held in the untriggered state of the valve at the inlet 2, there being fuel flow passages around the ball defined partly by projections 56 separated by fuel flow channels communicating with the inlet. In the untriggered state the ball 6 is supported on the projections 56 spaced from the inlet 2.

Adjacent the inlet 2 and surrounding the inlet 2 is a washer 52 of paramagnetic material e.g. ferrous material or other suitable metal. Likewise a metal washer 50 of paramagnetic material is adjacent to, and surrounding, the outlet 4. Between the washers is a sliding surface on which slides an inertial mass comprising a ring magnet 54 within a casing 58. The casing or magnetic housing 58 may be over-moulded and has a face 581 which covers the face of the ring magnet facing the washer 52. The thickness of the face 581 regulates the force which holds the ring magnet 54 to the washer 50. The casing is open at the faces of the ring magnet 54 facing the washer 50, so that the ring magnet can contact the washer 50, thereby maximising the strength of the magnetic circuit which latches the ball 6 to close the outlet 4 as described below.

In the untriggered state the ring magnet and its housing are adjacent the washer 52 at the inlet 2 to form part of a magnetic circuit that extends through the washer, the face 581, the ball and the magnet to hold the ball 6 at the inlet 2. In other words, the ball bearing is held in place as part of the magnetic circuit formed by the ring magnet and the metal washer. In this normal or untriggered state, fuel can flow around the ball, which may be supported at multiple points (e.g. three) by extrusions from the chamber wall. When an inertial event occurs, the ring magnet and its housing comprises an inertial mass which moves from the washer 52 to the washer 50, where it forms another magnetic circuit through the washer 50, the ball 6 and the magnet 8 to hold the ball 6 at the outlet. The ball 6 does not move in an inertial event until the magnetic circuit of the untriggered state is broken by the inertial mass 58, 54 moving. The magnetic field of the ring magnet 54 pulls the ball 6 from the inlet to the outlet. The ball's own inertia and fuel pressure may also aid the movement to the outlet once the ball is released from its initial position. The direction of movement of the ring magnet 54 during triggering is depicted in Figure 9 by arrow A, and is parallel to the (axial) direction of magnetisation depicted by arrow M.

Triggering the cut-off fuel valve may therefore involve the ring magnet 54 being thrown forward during a frontal impact. This breaks the original magnetic circuit holding the ball in the normal or untriggered position and establishes a new circuit with the washer at the other end of the device. This new circuit holds the ball bearing in place to seal off the outlet and prevent fuel flow. The ball 6 generally moves under a combination of the pull from the moving magnet as well as being pushed by the flow of fuel. As shown in Figure 10, the ring magnet and its housing and the washers and the sliding surface may be housed in a protective housing 60 extending from the inlet to the outlet. (Figure 11 illustrates the same device but with the cover or housing 60 removed).

Apertures may be provided through the housing 58 of the ring magnet 54 to allow air to pass through it especially when the protective housing is provided. Such apertures are unnecessary if there is sufficient clearance between the housing 58 of the magnet and the protective housing 60.

The ring magnet 54 may be replaced by a plurality of individual magnets in the housing 58 around the passage 12. The inertial mass comprising the ring magnet within the casing also provides means for resetting the valve after it has been triggered. The mass can be moved manually to the initial position; doing that resets the ball 6 to the initial position. An external magnet may be used to move the ball to its initial position.

Modifications. The ball 6 may not be a ball bearing which is ordinarily of steel. It could be of other material such as plastic in which paramagnetic material is embedded. The ball may be a permanent magnet itself. The ball may be coated with material which assists in sealing the outlet and/or reduces friction when the ball moves.

The ball 6 may be replaced by a member of paramagnetic material which is not spherical provided it can slide, roll or otherwise move along the passage 12 in an inertial event and block the outlet.

The valve body may be of moulded plastic or any other suitable material.

The passage 12 may have a length less than 3 diameters of the ball 6. It may have any length which allows fluid to flow from the inlet to the outlet in the untriggered state and which allows the valve member, e.g. ball 6, to move from the initial position to the position in which it blocks the outlet.

Whilst examples of the invention have been described in relation to a fuel cutoff valve, the invention may be applied to other fluids.

Whilst examples of the invention use a spherical valve member and a hemispherical sealing surface at the outlet the valve member may be of other shape complementary to the shape of a sealing surface at the outlet.

In use

In use, the valve is placed in a fuel line. The valve may be in a fuel supply line. It may be in a fuel return line or both fuel supply and return lines of a vehicle. It may be placed closely adjacent to the fuel tank of a vehicle. In some vehicles, a suitable location for the valve(s) is the front floor/dash panel area where the fuel line changes from a horizontal under-floor orientation to a vertical orientation to enter the rear of the engine bay.

Claims

1. A cut-off valve for stopping flow of a fluid, the valve comprising a valve body in which is defined a fuel flow passage between an inlet and an outlet, a valve member, which is of magnetic material, moveable along the passage between a first position allowing fluid to flow from the inlet to the outlet, and a second position in which the valve member blocks the outlet to stop flow of fluid, first magnetic means for holding the valve member in the first position, and second magnetic means for holding the valve member in the second position.

2. A valve according to claim 1, wherein the said fluid flow passage is a straight cylindrical passage having a diameter D and the valve member is circular and has a diameter slightly less than D to allow it to move along the passage.

3. A valve according to claim 1 or 2, wherein the valve member has a surface shaped to seal with a corresponding sealing surface around the said outlet to stop flow of fluid.

4. A valve according to claim 1, 2 or 3, wherein the valve member is spherical.

5. A valve according to claim 1, 2, 3 or 4, wherein the valve member is entirely of paramagnetic material.

6. A valve according to claim 1, 2, 3 or 4, wherein the valve member comprises a part of paramagnetic material and at least one other part of non-magnetic material.

7. A valve according to claim 1, 2, 3, 4, 5 or 6, wherein the first magnetic means comprises a permanent magnet for holding the valve member in the first position.

8. A valve according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the second magnetic means comprises one or more permanent magnets around the outlet for holding the valve member in the second position.

9. A valve according to any preceding claim, in combination with means for releasing the valve member from the second position.

10. A valve according to claim 8, wherein the second magnetic means is moveable away from the second position to release the valve member from the second position.

11. A valve according to any preceding claim, wherein the valve body is transparent or translucent at at least the second position.

12. A valve according to claim 1, 2, 3, 4, 5 or 6, wherein the valve body has an outer surface about the said passage between the first and second positions, and an inertial mass moveable on said outer surface between the first and second positions, the inertial mass including at least one permanent magnet, the said first magnetic means comprising magnetic material at the first position which, when the inertial mass is at the first position, completes with the valve member and the said at least one permanent magnet a magnetic circuit which holds the valve member at the first position, and the second magnetic means comprises magnetic material at the second position which, when the inertial mass is at the second position completes, with the valve member and the said at least one permanent magnet, a magnetic circuit which holds the valve member at the second position.

13. A valve according to claim 12, wherein the magnetic material at the first and second positions is paramagnetic material.

14. A valve according to any preceding claim, wherein the inlet is between the first and second positions.

15. A valve according to any one of claims 1 to 13, wherein the first position is between the inlet and the outlet, at least one fluid flow path being provided to allow fluid to pass the valve member in the first position.

16. A vehicle comprising a valve according to any preceding claim fitted in a fuel line of the vehicle.

17. A vehicle according to claim 16, wherein valves according to any preceding claim are fitted in the fuel feed and return-lines of the vehicle.

18. A vehicle according to claim 16 or 17, wherein the or each valve is mounted on, or adjacent to, the fuel tank of the vehicle.

19. A valve substantially as hereinbefore described with reference to:

Figures 1, 2 or 3; Figures 5 to 7; or Figures 8 to 11; of the accompanying drawings.