WO2001006157A1

WO2001006157A1 - A multi-port valve, and a marine propulsion unit having a multi-port valve

Info

Publication number: WO2001006157A1
Application number: PCT/GB2000/002747
Authority: WO
Inventors: Robert D. Glen
Original assignee: Ep Barrus Limited
Priority date: 1999-07-16
Filing date: 2000-07-17
Publication date: 2001-01-25
Also published as: AU6297500A; GB9916695D0; GB2352020A

Abstract

A multi-port valve comprises a plurality of input ports (4, 5, 6) and one or more output ports (7, 8, 9). The valve has a closure member (3) disposed in a cavity (2) within a housing (1). A plurality of flow passages for fluid (10, 11, 12) are defined in the closure member, with there being one fluid flow passage for each input port. Rotating the closure member thus enables all input ports to be simultaneously connected with or isolated from the input port(s).

Description

A Multi-Port Valve, and a Marine Propulsion Unit having a Multi-Port Valve

The present invention relates to a valve, and more particularly to a valve having more than one fluid flow path through the valve. The invention also relates to a marine propulsion unit having such a valve.

One well-known type of conventional valves is the ball-valve. A ball-valve consists essentially of a housing having a fluid input port, an input fluid passage extending within the housing from the fluid input port, a fluid output port, and an output fluid passage extending within the housing from the fluid output port. A closure member, or "ball", is provided within the housing between the input fluid passage and the output fluid passage, and is mounted for rotation about an axis. A passage for fluid is defined within the ball. The valve is opened by rotating the ball so that the fluid passage within the ball connects the input fluid passage to the output fluid passage, thereby defining a fluid flow path between the fluid input port and the fluid output port. The fluid flow path through the valve is made up of the input fluid passage within the housing, the fluid passage within the ball, and the output fluid passage within the housing.

The valve is closed by rotating the ball from its open position so that the fluid passage defined within the ball is no longer aligned with the fluid input passage and the fluid output passage, thereby isolating the fluid output port from the fluid input port.

A conventional ball-valve is a simple and effective valve, and is used in many applications. However, it is possible to envisage applications in which it is desired to simultaneously control a number of fluid flows. If conventional ball-valves were used in such applications, it would be necessary to provide a separate ball-valve for each fluid flow to be controlled.

A first aspect of the present invention provides a valve providing, in its open state, a plurality of fluid flow paths through the valve, the valve being operable between an open state in which each fluid flow path through the valve is open and a closed state in which each fluid flow path through the valve is closed. In a preferred embodiment, the valve comprises a housing having first and second input ports for fluid and one or more output ports for fluid; and a closure member provided within the housing, first and second fluid passage being defined within the closure member; the closure member being operable either to connect the first and second input ports with the output port or with a respective output port or to isolate each of the input ports from the or each output port.

A second aspect of the present invention provides a marine propulsion unit comprising a valve as described above.

A third aspect of the present invention provides a seal for a valve as described above.

Preferred features of the invention are set out in the dependent claims.

Preferred embodiments of the present invention will now be described, by way of illustrative example, with reference to the accompanying drawings in which:

Figure 1(a) is a schematic view of a first valve according to the present invention in its open state;

Figure 1(b) is a schematic view of a first valve according to the present invention in its closed state;

Figure 1(c) is a partial enlarged view of a modified embodiment of the valve shown in Figures 1(a) and 1(b);

Figure 2(a) is a schematic view of a second valve according to the present invention in its closed state;

Figure 2(b) is a cross-section along the line XX of Figure 2(a); Figure 3(a) is a schematic view of a third valve according to the present invention in its open state;

Figure 3(b) is a schematic view of a fourth valve according to the present invention in its open state;

Figure 4 is a schematic view of a fifth valve according to the present invention in its open state; and

Figure 5 is a schematic view of a marine propulsion unit incorporating a valve of the present invention.

A first embodiment of the invention is illustrated in Figure 1(a), which shows the valve in its open position, and Figure 1(b), which shows the valve in its closed position.

In this embodiment, the valve of the invention is embodied as a ball- valve. The valve comprises a housing 1. A cavity 2 is defined within the housing 1 , and a closure member 3 is disposed within the cavity 2.

The housing is provided with a plurality of fluid input ports 4, 5, 6 and with a plurality of fluid output ports 7, 8, 9. Three fluid input ports and three fluid output ports are shown in Figures 1(a) and 1(b), but the invention is not limited to a valve having three fluid input ports and three fluid output ports and can be applied to a valve having two or more input ports and output ports. A plurality of input fluid passages 4(a), 5(a), 6(a) are defined in the housing, with one input passage being provided for each fluid input port. The fluid input passages extend from a corresponding one of the fluid input ports 4, ^'5, 6 to the cavity 2. Similarly, a plurality of fluid output passages 7(a) 8(a), 9(a) are defined in the housing, with one fluid output passage being provided for each fluid output port. The fluid output passages extend from the cavity 2 to a respective one of the output ports 7, 8, 9. The closure member 3 is provided with a plurality of through passages 10, 11, 12. The number of through passages is equal to the number of fluid input ports.

The closure member 3 has the form of a solid of revolution, for example a sphere. It is rotatably mounted within the cavity 2, by means of a shaft 13 which is received in a cylindrical aperture in the housing 1. A handle 14 is provided on the shaft 13, to allow easy rotation of the shaft 13 and the closure member 3.

Figure 1(a) shows the valve in its open position. The through passages 10, 11, 12 in the closure member 3 are positioned such that, when the valve is open, the upper through passage 10 aligns with the upper fluid input passage 4a and the upper fluid output passage 7a, thereby connecting the upper input port 4 to the upper output port 7 and defining a first fluid flow path through the valve. Similarly, the middle through passage 11 aligns with the middle input passage 5 a and the middle output passage 8a, thereby connecting the middle input port 5 with the middle output port 8, and so defining a second fluid flow path through the valve. The lower through passage 12 aligns with both the lower input passage 6a and the lower output passage 9a thereby connecting the lower input port 6 with the lower output port 9 and defining a third fluid flow path through the valve. The three fluid flow paths through the valve are independent from one another, in that one fluid path does not communicate with either of the other fluid paths within the valve.

The valve is closed simply by rotating the closure member 3 by means of the handle 14 so that the through passage 10, 11, 12 do not align with the input passages 4a, 5a, 6a or the output passages 7a, 8a, 9a. The closure member can be rotated by manually moving the handle 14 so as to rotate the closure member. Alternatively, the valve could be opened and closed using any suitable actuating means - for example, mechanical, pneumatic, electrical, electro-mechanical, or electromagnetic actuation means could be used.

It is highly desirable that, when the valve is closed, there is a fluid tight seal between the closure member 3 and the input fluid passages 4a, 5a, 6a. This is to prevent fluid that enters one of the fluid input passages from leaking into another of the fluid input passages or into one of the fluid output passages 7a, 8a, 9a. It is also desirable for their to be a fluid-tight seal when the valve is in its open state, to prevent fluid leaking from one fluid flow path to another, and to prevent fluid leaking out of the valve around the shaft 13. In principle, this sealing can be achieved by choosing the dimensions of the closure member so as make a fluid-tight seal between the closure member and the face of the cavity in which the input fluid passages 4a, 5a, 6a are provided, and between the closure member and the face of the cavity in which the output fluid passages 7a, 8a, 9a are provided. The sealing can be improved by making the closure member of a resilient material, so that it can accommodate slight variations in the dimensions of the cavity 2.

An alternative method of ensuring fluid-tight seals is to provide seals within the cavity 2 to prevent leakage. Figure 1(c) is a partial enlarged view of a valve similar to that of Figures 1(a) and 1(b) but incorporating seals, and shows the region of the housing around the cavity 2. A seal 15 is provided on the input side of the closure member 3, between the closure member 3 and the housing 1. The seal 15 is provided with through passages 4b, 5b, 6b, which are aligned with the input fluid passages 4a, 5a, 6a in the housing. The seal 15 is a fluid-tight fit between the housing 1 and the closure member 3, so that fluid entering through one of the input passages 4a, 5a, 6a cannot flow between the housing 1 and the seal 15, or between the seal 15 and the closure member 3. Thus, when the valve is in its open position, the seal 15 ensures that fluid entering through one of the input passages 4a, 5a, 6a is directed into the respective through passage 10, 11, 12 in the closure member 3. When the valve is in its closed position, the seal ensures that fluid entering the input passages 4a, 5a, 6a is blocked, and cannot pass into another of the input passages or into one of the output passages 7a, 8a, 9a.

A corresponding seal 16 is provided at the output side of the closure member 3. This seal has 3 through passages 7b, 8b, 9b, which are aligned with the output passages 7a, 8a, 9a.

When a valve according to this embodiment of the invention is open a plurality of independent fluid paths (three fluid paths in the valve shown in Figure 1(c)) are defined through the valve. The first fluid path, for example, is formed by the upper input passage 4a, the upper through passages 4b through the seal 15, the upper passage 10 through the ball 3, the upper through passages 7b through the seal 16, and the upper output passage 7a.

The seals 15, 16 are preferably formed of a resilient material, so that any slight dimensional changes, due for example to thermal contraction or expansion, can be accommodated while retaining a fluid-tight seal. PTFE (polytetrafluoroethylene) is a suitable material for the seals 15, 16, but any material having the required properties can be used.

The face of the seal 15,16 adjacent to the closure member 3 is shaped to provide a fluid- tight seal between the seal and the closure member. Similarly, the face of the seal adjacent the housing 2 is shaped to provide a fluid-tight seal between the seal and the housing. For a valve with a spherical closure member, for example, the face of the seal 15,16 adjacent to the closure member will be provided with a part-spherical concavity.

In the valves of Figures 1(a) to 1(c), the three through passages 10, 11, 12 in the closure member 3 are disposed one above the other. The input ports 4, 5, 6, the input passages 4a, 5a, 6a, the output passages 7a, 8a, 9a and the output ports 7, 8, 9 are also disposed one above the other. However, the input and output fluid ports, the input and output fluid passages, and the through passages in the closure member can be arranged in any desired configuration. For example, Figures 2(a) and 2(b) show an alternative embodiment, in which the input and output ports, the input and output passages, and the through passages in the closure member are arranged in a triangular configuration. (Figure 2(b) is a section along the line XX of Figure 2(a).) The valve of Figures 2(a) and 2(b) again provides three independent fluid paths through the valve when it is open.

In the embodiments described above, the valve has had the same number of output ports as input ports. It is, however, possible for two or more of the input ports to be connected to a single output port, so that the number of output ports can be lower than the number of input ports. This can be done, for example, by disposing the output fluid passages 7a, 8 a, 9a so that they feed into a common output port 17, as shown in Figure 3(a).

Alternatively, the three through passages 10, 11, 12 in the closure member 3 could converge so that they open into a common output fluid passage 17b in the housing as shown in Figure 3(b). The common output fluid passage leads to a common output port 17.

In an alternative embodiment (not illustrated), the valve can be provided with one or more diverging fluid flow paths, so that the valve has more output ports than input ports. For example, one of the through passages in the closure member could branch into two, or one of the output fluid passages could branch into two.

The present invention is not limited to application to a so-called ball-valve, but can be applied to other types of valves.

As an example, Figure 4 shows the invention applied to a valve in which the closure member is substantially cylindrical, although provided with a slight taper to ensure good sealing. The principle of operation of a valve according to this embodiment of the invention is similar to that of the valve shown in Figures 1(a) and 1(b), and again provides a plurality of independent fluid paths (three fluid paths in the case of the valve shown in Figure 4) through the valve when the valve is open.

Although the valve Figure 4 corresponds generally to the valve of Figures 1(a) to 1(c), the valves shown in Figures 2(a) and 2(b), Figure 3(a) or Figure 3(b) could also be embodied using a substantially cylindrical closure member.

The valves shown in Figures 2(a) and 2(b), Figure 3(a) or Figure 3(b) can be provided with seals similar to those shown in Figure 1(c), to ensure fluid-tight sealing between the closure member 3 and the cavity 2. Alternatively, fluid tight sealing can be obtained directly between the closure member 3 and the faces of the cavity 2. The valve of Figure 4 can also be provided with a seal. A valve according to the invention can be used in any application where it is currently necessary to use two or more conventional valves each having a single input port and a single output port. Using a valve according to the present invention means that all the fluid passages can be opened or closed in a single action, whereas the use of a multiplicity of conventional single port valves would require each fluid flow to be opened and closed separately.

One particular application of the present invention is in relation to a post-immersion restart system for a marine propulsion unit. When a boat capsizes the propulsion unit is submerged and it will flood with water. Even in the case of a vessel provided with a self-righting capability, the engine is generally flooded with water by the time the vessel has righted itself. In order to restart the engine it is necessary to drain each cylinder of water, and also to drain the carburettor or carburettors. A post immersion restart system for draining a carburettor is described in European Patent EP-B-0 219 278, and a post immersion re-start system incorporating crankcase drainage is described in co-pending UK Patent Application No. 9909947.5. The contents of these two documents are hereby incorporated by reference.

A marine propulsion unit will generally have more than one cylinder. If conventional valves having just a single fluid flow passage are used as a crankcase drain in a post- immersion restart system, it would be necessary to provide a separate valve for each cylinder of the engine. Accordingly, a crew member would have to open each valve separately to drain each cylinder, restart the engine, and then close each valve separately. Since the crew member attempting to do this will have been flung into the sea when his vessel capsized and will have had to scramble back into the vessel, and moreover since the restarting operation is likely to be carried out in heavy seas and possibly at night, it is desirable for this operation to be made as simple as possible. According to the present invention, therefore, a marine propulsion unit is provided with a multi-flow path valve of the type described above. The number of fluid flow paths through the valve is equal to, or possibly greater than, the number of cylinders in the engine. Thus, the valves illustrated in Figure l(a)-4, which have three input ports, would be suitable for use with a three-cylinder marine propulsion unit. The drain from the crankcase of the first cylinder would be fed to the first input port 4, the drain from the crankcase of the second cylinder to the second input port 5, and the drain from the crankcase of the third cylinder to the third input port 6. Opening the valve would thus enable all three cylinders to be drained simultaneously and, when all cylinders had been drained, closing the valve would close the drains of all cylinders at once.

An engine having two cylinders would require a valve having at least two fluid input ports. A valve according to the invention having two input ports could be used, or a valve having three input ports could be used with one input port blanked-off. As a further example, an engine having six cylinders would require a valve having at least six fluid input ports or, as an alternative, two valves each with three input ports could be used with a six cylinder engine. While this means that two valves are needed for the engine, it does allow one valve to be used across a range of engines, rather than needing a large number of valves having different numbers of input ports. Furthermore, replacing six conventional valves by two valves of the invention significantly reduces the difficulty of restarting the engine.

Similarly, in the case of an engine having more than one carburettor, it is possible for the drain from each carburettor to be fed to a multi-flow passage valve of the present invention. Again, the number of fluid inputs of the valve should be equal to or greater than the number of carburettors in the engine. This then allows all carburettors to be drained simply by using a single valve. This again simplifies the restarting process, compared to a prior art propulsion unit in which each carburettor is provided with its own separate drainage valve.

When a valve of the present invention is used in a post-immersion restart system, it is preferable for a valve that provides, in its open state, a plurality of independent fluid paths. This can be done using a valve of the general type shown in Figures 1(a) and 1(b), Figure 1(c), Figures 2(a) and 2(b) and Figure 4. The reasons for this will be explained with regard to Figure 5. Figure 5 schematically shows a marine propulsion unit that is provided with a carburettor drain, which shows a valve of the invention. Figure 5 relates to a three- cylinder marine propulsion unit in which each cylinder is provided with a separate carburettor, so that the propulsion unit has three carburettors 21, 22, 23. The cylinders are stacked one above another, so that the carburettors are also arranged vertically one above another. The carburettors 21, 22,23 are the only components of the propulsion unit shown in Figure 5, since they are the only components relevant to the following description. The marine propulsion unit may be an inboard motor or an outboard motor.

The marine propulsion unit of Figure 5 is provided with a carburettor drain system, that enable the carburettors to be drained of water when the vessel is righted after a capsize. Each carburettor is provided with a drain 21a, 22a, 23a to enable water to be drained, for example in the manner described in EP-B-0 219 278. The carburettor drains 21a, 21b, 21c are connected to input ports 4, 5, 6 of a valve 20 according to the present invention. Thus, opening the valve 20 opens the carburettor drain of each carburettor of the marine propulsion unit, and allows water to be drained from each carburettor. It is far easier for a crew member to be able to drain all the carburettors by opening a single valve, then having to open a separate valve to drain each carburettor. Once all water has drained from the carburettors 21, 22, 23, closing the valve 20 enables all the carburettor drains to be closed in a single operation.

When the valve 20 is open, water can drain from all three carburettors, via their respective drains and via the respective fluid path through the valve 20. For example, water from the upper carburettor drains through the drain 21a, enters the first input port 4 of the valve 20, passes through the first flow passage 10, and leaves the valve by the first output port 7.

Since the carburettors 21, 22, 23 are stacked vertically, one above the other, it is desirable that the float chamber of each carburettor is not connected to the float chambers of the other carburettors. If the float chambers of the carburettors were connected, fuel entering the upper carburettor would tend to drain into the lower carburettor. The lower carburettor would thus be flooded with fuel, while the upper carburettor would be starved of fuel.

Furthermore, when the valve 20 is opened to drain the carburettors it is undesirable for water to be able to drain from the upper carburettor 21 into the middle or lower carburettors 22, 23, or for water to drain from the middle carburettor 21 into the lower carburettors 23.

It is accordingly preferable that the valve 20 provides, in its open state, three independent fluid paths through the valve. It is also preferable that there is no leakage between one fluid path and another when the valve is open, and that there is no leakage between one input of the valve and the other inputs of the valve when the valve is closed. This ensures that water draining from the upper carburettor 21 cannot flow back into the middle or lower carburettors 22, 23, and that water draining from the middle carburettor 21 cannot flow back into the lower carburettors 23. It also ensures that there is no communication between the float chamber of one of the carburettors and the float chambers of other carburettors. Thus, it is preferred to use a valve of the general construction shown in Figures 1(a) and 1(b), Figure 1(c), Figures 2(a) and 2(b) or Figure 4.

Figure 5 shows a valve 20 that is manually operated by a handle 14. It is alternatively possible to use a mechanically actuated valve, that is actuated in any of ways mentioned above.

It is preferable that drain pipes 21b, 22b, 23b, otherwise known as "tails" are provided on the outlet 7, 8, 9 of the valve 20. These direct water draining from the carburettor 21, 22, 23 to a convenient location. Moreover, the weight of fluid in the tails will assist the drainage of the carburettors, and the longer the tails the better will be the drainage of the carburettors. To obtain the best drainage effect, it is preferred that the tails provide a continuous downwards fluid path. A crew member is able to monitor the progress of the drainage process by observing the fluid output from the tails, and this provides a check that, for example, the drain from one carburettor is not blocked.

Claims

CLAIMS:

1. A valve providing, in its open state, a plurality of fluid flow paths through the valve, the valve being operable between an open state in which each fluid flow path through the valve is open and a closed state in which each fluid flow path through the valve is closed.

2. A valve as claimed in claim 1 and comprising: a housing having first and second input ports for fluid and one or more output ports for fluid; and a closure member provided within the housing, first and second fluid passage being defined within the closure member; the closure member being operable either to connect the first and second input ports with the output port or with a respective output port or to isolate each of the input ports from the or each output port.

3. A valve as claimed in claim 2 wherein the closure member can be put either in a first orientation in which the fluid passages defined in the closure member connect the first and second input ports with the output port or with a respective output port or in a second orientation in which each input port is isolated from the or each output port.

4. A valve as claimed in claim 2 and comprising: first and second fluid output ports; wherein the closure member can be put in a first orientation, in which the first fluid passage connects the first input port with the first output port and in which the second fluid passage connects the second input port with the second output port, or in a second orientation in which the first fluid input port is isolated from both the first and second output ports and in which the second fluid input port is isolated from both the first and second output ports.

5. A valve as claimed in claim 4, wherein the first fluid input port is isolated from the second fluid input port when the closure member is in its second orientation.

6. A valve as claimed in claim 4 or 5 wherein the first fluid passage does not directly communicate with the second fluid passage.

7. A valve as claimed in claim 4, 5 or 6 and further comprising a third input port; a third output port; and a third fluid passage defined in the closure member; wherein the third fluid passage connects the third input port with the third output port when the closure member is in its first orientation.

8. A valve as claimed in claim 3, 4, 5, 6 or 8 wherein the closure member is changed between its first orientation and its second orientation by rotating it relative to the housing.

9. A valve as claimed in any of claims 2 to 8 wherein the closure member is substantially spherical.

10. A valve as claimed in any of claims 2 to 8, wherein the closure member is substantially cylindrical.

11. A valve as claimed in claim 10, wherein the closure member is a tapered cylinder.

12. A valve as claimed in any preceding claim wherein a fluid flow path through the valve is independent from the or each other fluid flow path through the valve.

13. A marine propulsion unit comprising a valve as defined in any of claims 1 to 12.

14. A marine propulsion unit as claimed in claim 13, wherein the propulsion unit has n cylinders (n > 1); and the valve has at least n fluid input ports.

15. A marine propulsion unit as claimed in claim 14 wherein each cylinder is provided with a crank case drainage outlet connected to a respective input port of the valve.

16. A marine propulsion unit as claimed in claim 12 and comprising m carburettors (m > 1), and wherein the valve has at least m fluid input ports.

17. A marine propulsion unit as claimed in claim 16, wherein each carburettor is provided with a drain port connected to a respective input port of the valve.

18. A seal for a valve as defined in any of claims 1 to 12, a first face of the seal sealing, in use, against the housing and a second face of the seal sealing, in use, against the closure member; wherein a plurality of fluid flow passages are defined in the seal, the fluid flow passages extending from the first face of the seal to the second face of the seal.

19. A seal as claimed in claim 18 wherein the seal is made from a resilient material.

20. A seal as claimed in claim 19 wherein the resilient material is PTFE.