This invention relates to a gas fuelling system for a vehicle.

Gas fuelled vehicles are growing ever more popular as a sustainable option enabling commuting whilst using a cleaner fuel, a fuel that can be combusted in an internal combustion engine with lower emissions of fewer pollutants. For example, many gas fuelled three wheeler vehicles are to be seen on the roads of India. Increasingly, gas fuelled motorcycles and scooters are also becoming popular as well.

Past vehicle gas fuelling systems, such as CNG and LPG gas fuelling systems are bulky. As well as the gaseous fuel tank, other components that need to be included are the safety shut off valve, a gas pressure reducer - which may be described as a first stage reducer, various of which are connected with lightweight high pressure hose or ductwork which may extend over some distance. In addition, mounting components are required to be accommodated to mount all of these components to the vehicle frame which requires significant strength in the region accommodating the gas fuelling system. A frame "cradle" is typically provided for this purpose Particularly in 2 wheeler vehicle applications, but potentially in 3 or 4 wheeler vehicle applications as well, packaging space available to accommodate all these components is very limited. It would be desirable to reduce the space taken up by the gas fuelling system.

It is therefore an object of the present invention to provide a gas fuelling system that takes up less space in a vehicle, particularly a two wheeler and potentially for three or four wheeler vehicle.

With this object in view, the present invention provides a gas fuelling system for a vehicle comprising:

a gaseous fuel tank;

a gaseous fuel ON/OFF control valve operable to enable fuel supply from the fuel tank to the engine when required for vehicle operation;

a gaseous fuel pressure regulator for reducing gaseous fuel pressure between the gaseous fuel tank and the engine;

wherein said ON/OFF control valve and said gaseous pressure regulator are directly connected. Preferably, the ON/OFF control valve is a solenoid actuated valve.

Preferably the ON/OFF control valve is activated to an "ON" state during normal operating conditions and to an "OFF" state when the gas supply is to be halted.

By "directly connected" is intended that the gaseous fuel ON/OFF control valve and gaseous fuel pressure regulator are not significantly spatially separated (from a packaging and functioning perspective) being connected to each other directly or by a part extending no more than a short distance, contrast being made from the sometimes significant and circuitous length of high pressure hose or duct work used in prior gas fuelling systems. Desirably, the gaseous fuel ON/OFF control valve and gaseous fuel pressure regulator are directly connected by a connector or coupling, for example connecting an outlet of the gaseous fuel ON/OFF control valve to the outlet of the gaseous fuel pressure regulator.

The connector is no longer in the form of a high pressure hose or duct. Such direct connection reduces space required by the gas fuelling system and offers a direct packaging advantage for the gas fuelling system.

The connector could take various forms. One advantageous form of connector allows a threadable connection to be made between a portion of the gaseous fuel ON/OFF control valve and an adjacent portion of the gaseous fuel pressure regulator, which - acting to reduce gaseous fuel pressure from gaseous fuel tank pressure to required pressure for supply to the engine - may be termed a reducer. As pressure reduction may take place over multiple stages, the reducer may be termed a "first stage reducer" performing the first stage of pressure reduction from gaseous fuel tank pressure towards engine operating pressure .Each portion of the neighbouring, or adjacent, gas fuelling system components may be coupled together conveniently with a connection being made secure by tightening a coupler over a thread formed on one or both portions. Sealing means at the connection are advantageously employed to minimize leakage of gaseous fuel.

The gaseous fuel pressure regulator and gaseous fuel ON/OFF control valve are components having appreciable strength and rigidity, certainly in comparison to high pressure hose or duct work. So, the assembly of the fuel pressure regulator and ON/OFF control valve which form the connection between the two components has sufficient strength and rigidity that the assembly acts as a load carrying member for the ON/OFF control valve. This could not have been done using high pressure hose or duct work and results in a further advantage since the frame of the vehicle can be designed taking into account the use of the assembly of gaseous fuel pressure regulator and gaseous primary control valve. This may provide ease of packaging of the gaseous fuel pressure regulator within the existing available frame of motorcycle or may otherwise ease design constraints on the "cradle" of a frame used to support the gas fuelling system in two wheeler applications. That is, it may be possible to reduce the strength of that cradle and employ - lower cost structural or load bearing members in that cradle as a result of using the assembly of the gaseous fuel ON/OFF control valve and gaseous fuel pressure regulator as a load bearing member.

The assembly of gaseous fuel ON/OFF control valve and gaseous fuel pressure regulator, is fixed to the vehicle frame by suitable mounting means, for example in the form of mounting bracket(s) and clamp(s).

The gas fuelling system is particularly applicable to a two wheeler vehicle, such as a motorcycle. However, the gas fuelling system may also be used to advantage in a three " wheeler vehicle such as an autorickshaw or 4 wheeler.

The gas fuelling system is not to be limited by the nature of the gaseous fuel selected for vehicle operation. Typical gaseous fuels include CNG and LPG fuels. Other gaseous fuels are not excluded.

The gas fuelling system of the present invention may be more fully understood from the following non-limiting description of a preferred embodiment of the system made with reference to the accompanying drawings in which:

Fig 1 is a gas fuelling system employed in a prior 3 wheeler vehicle

Fig 2a is a schematic diagram of a gas fuelling system, suitable for a two wheeler vehicle such as a motorcycle, in accordance with one embodiment of the present invention.

Fig. 2b is a partial view along axis X of Fig. 2a.

Fig. 2c is a section view showing connection between first stage reducer and CNG flow control valve in the gas fuelling system shown in Figs. 2a and 2b.

Fig. 3a is a first (left) side view of a front portion of a motorcycle including the gas fuelling system as shown in Fig 2.

Fig. 3b is a partial view showing connection of an assembly of first stage reducer and CNG primary control valve to the frame of the motorcycle as shown in Fig. 3a.

Fig. 4 is a second (right) side view of a front portion of the motorcycle as shown in Fig 3.

Referring now to Fig. 1, there is shown a gas fuelling system 10 used to supply CNG, a gaseous fuel, to a three wheeler vehicle (not shown) as typically used for taxi type functions throughout India. The gas fuelling system 10 includes a cylindrical CNG fuel tank 15 (shown in an end-on view), a steel part to withstand the high pressure (about 250 bar) of CNG in the CNG fuel tank 15. Valve 15a is a safety shut-off valve for CNG fuel tank 15, next to which is port 33 which acts as inlet to the fuel tank 15 while filling fuel and as outlet when - fuel is used for running the vehicle.

Gaseous fuel pressure regulator 30 is in the form of a first stage reducer as above described. The first stage reducer, which is a conventional part, acts to reduce pressure of CNG fuel from the CNG fuel tank 15 pressure to a pressure suitable for supply to the engine. Further reduction in CNG fuel pressure may be required prior to delivery to the engine. The actual CNG fuel supply to the engine will be controlled in accordance with vehicle operating conditions and further description is not required in the context of the present invention.

Downstream of first stage reducer 30 is a CNG ON/OFF control valve 20 having a " brass body. This CNG ON/OFF control valve 20 is a solenoid actuated valve and it is turned "ON" (open) and "OFF" (closed) as required by the operating state of the three wheeler vehicle. In normal three wheeler vehicle operating conditions, the CNG ON/OFF control valve 20 will be turned "ON".

CNG ON/OFF control valve 20 is mounted to a frame of the three wheeler by a mounting bracket 19.

It may be understood from the above description that the gas fuelling system 10 shown in Fig. 1 includes a number of critical components. Further, the CNG ON/OFF control valve 20 and first stage reducer 30 are connected by a high pressure duct or hose 25 which extends some circuitous and significant length, the path for the high pressure duct 25 perhaps being chosen by the manufacturer/service operator to ease connection of the various components. Accommodation of all of these components takes a significant amount of space, relative to that available for packaging the gas fuelling system, and the three wheeler gas fuelling system 10 cannot be easily applied to the two wheel vehicle such as a motorcycle where space and packaging constraints are even more severe.

Referring now to Figs. 2 to 4, description follows of a gas fuelling system 110 for a motorcycle 100. The motorcycle 100 again runs on CNG fuel which is supplied from CNG fuel tank 115, having an outer cover 175 (as shown in Figs. 3 and 4) next to which is located a gaseous fuel pressure regulator 130 in the form of a first stage reducer which is made of brass. First stage reducer is communicated with CNG Fuel tank 115 by an inlet 131. The first stage reducer 130, acts, conventionally, to reduce pressure of CNG fuel from the CNG fuel tank 115 pressure to a pressure suitable for CNG fuel supply to the engine. Further reduction in CNG fuel pressure may be required prior to delivery of CNG fuel to the engine. The actual CNG fuel supply to the engine will be controlled in accordance with motorcycle 100 operating conditions and further description is not required in the context of the " present description.

Downstream of first stage reducer 130 is provided a CNG ON/OFF control valve 120 operable to enable CNG fuel supply from CNG fuel tank 115 to the engine (not shown), through outlet 123, when required for motorcycle 100 operation. Though CNG fuel is the primary fuel for the motorcycle 100, a reserve or auxiliary liquid fuel (petrol) tank may also be provided to enable operation, at least to a limited extent, when CNG fuel reserves run low and CNG fuel cannot be readily obtained, perhaps as in rural areas.

This CNG ON/OFF control valve 120 is a solenoid actuated valve and it is turned on (open) and off (closed) as required by the operating state of motorcycle 100. In normal motorcycle 100 operating conditions, the CNG ON/OFF control valve 120 will be turned "on". The CNG ON/OFF control valve 120 is included as a mandatory safety feature in motorcycle 100.

Connection of CNG ON/OFF control valve 120 and first stage reducer 130 is made in a very different way than explained for the prior art gas fuelling system 10 described with reference to Fig. 1. In that case, the connection was made "indirectly" using high pressure duct or hose 25, that connection extending over a circuitous and significant length, perhaps suiting convenience of manufacturer/service operator without regard to the objective of reducing space requirements for the gas fuelling system 10.

In gas fuelling system 110 for motorcycle 100, the CNG ON/OFF control valve 120 and the first stage reducer 130 are "directly" connected to form assembly 150. That is, the CNG ON/OFF control valve 120 and first stage reducer 130 are are directly connected by a connector, or coupling, 142, connecting an inlet 122 of the CNG ON/OFF control valve 120 to an outlet 132 of the first stage reducer 130. The connector 142 is no longer in the form of a length of high pressure hose or duct which cannot be relied upon to serve any other function than fluidly communicating CNG ON/OFF control valve 120 and first stage reducer 130. Such direct connection reduces space required to accommodate the gas fuelling system 110 and offers a direct packaging advantage for the gas fuelling system 110.

The connector 142, in the form of a threaded brass coupling, allows a threadable connection to be made between an inlet portion 122 of the CNG ON/OFF control valve 120 and an adjacent outlet portion 132 of the first stage reducer 130. Portion(s) 122 and 132 are correspondingly threaded. The connector 142 acts as a load bearing member for CNG ON/OFF control valve 120. Hence, no separate mounting, for example by a bracket as required in the three wheeler example above, is required on the motorcycle 100 frame for " the CNG ON/OFF control valve 120 component. This layout also allows the first stage reducer 130 to be mounted remotely of the emergency shut-off valve 15a and aids in giving the vehicle designer flexibility in efficiently packaging these items on a vehicle. Portions 122 and 132 are coupled together with a connection being made secure, and with gas-tight seal, by tightening a hexagonal brass portion of connector 142 over a thread formed on one or both portions 122 and 132. Washers 129, for example copper washers, are inserted between portions 122 and 132 (as shown in Fig. 2c). Washer 129 thickness is controlled to have the desired orientation of the CNG" ON/OFF control valve 120 with the outlet portion 132 of the first stage reducer 130.

Some other components of the gas fuelling system 110 may also be mentioned at this point. A pressure gauge 170 and CNG filler point 180 are provided proximate the first stage reducer 130. The purpose of these components is self-evident: to enable monitoring of fuel pressure and enable refilling of CNG fuel tank 115.

The CNG ON/OFF control valve 120 and first stage reducer 130 are components having appreciable strength and rigidity, as may be inferred from the drawings and certainly in comparison to high pressure hose or duct 25 as shown and described with reference to Fig. 1. So, the assembly 150 of the CNG ON/OFF control valve 120 and first stage reducer 130 has sufficient strength and rigidity for proper supporting and operation. This could not have been done using high pressure hose or duct work 25. This may ease design constraints on the "cradle" of the motorycle frame 190 used to support the gas fuelling system 110, notably the fuel tank 115 contained within fuel tank cover 175 as shown in Figs. 3 and 4 which illustrate the motorcycle 100 including the gas fuelling system 110 as described here or can be packaged with in the existing available frame of Motorcycle.

The assembly 150 of CNG ON/OFF control valve 120 and first stage reducer, being a load bearing member of the motorcycle frame 190, acts as a mounting point at which the " assembly 150 may be clamped to a down tube 192 of the motorcycle frame 190 by clamping the assembly 150 to mounting bracket 186-with a single clamp 185, the mounting bracket 186 and clamp 185 being of conventional form.

Use of the assembly 150 allows achievement of a number of advantages. In addition to assembly 150 acting as a load bearing member for CNG ON/OFF control valve 120, manufacture and serviceability is much simplified by use of assembly 150. Handling may also be facilitated by supply of the assembly 150 as a single part.

Modifications and variations to the gas fuelling system of the present invention may be apparent to the skilled reader of this disclosure. Such modifications and variations are to be deemed within the scope of the present invention. For example, the gas fuelling system may be employed in a motorcycle including the frame and other features of our co-pending Indian Provisional Application entitled "A Gas Fuelled Motorcycle" also filed on 9 June 2010 under our docket number 01.01.052.IN and the contents of which are hereby incorporated herein by reference.

WE CLAIM:

1. A gas fuelling system for a vehicle comprising:

a gaseous fuel tank;

a gaseous fuel ON/OFF control valve operable to enable fuel supply from the fuel tank to the engine when required for vehicle operation; and

a gaseous fuel pressure regulator for reducing gaseous fuel pressure between the gaseous fuel tank and the engine;

wherein said ON/OFF control valve and said gaseous fuel pressure regulator are directly connected.

2. The gas fuelling system of claim 1 wherein the ON/OFF control valve is a solenoid actuated valve.

3. The gas fuelling system of claim 1 or 2 wherein the gaseous fuel ON/OFF control valve and gaseous fuel pressure regulator are directly connected by a connector or coupling

- connecting an outlet of the gaseous fuel ON/OFF control valve to the inlet of the gaseous fuel pressure regulator.

4. The gas fuelling system of claim 3 wherein said connector or coupling allows a thread able connection to be directly made between a portion of the gaseous fuel ON/OFF control valve and an adjacent portion of the gaseous fuel pressure regulator.

5. The gas fuelling system of any one of the preceding claims wherein an assembly of the fuel pressure regulator and ON/OFF control valve acts as a load carrying member for the ON/OFF control valve.

6. The gas fuelling system of claim 5 wherein said assembly of the fuel pressure regulator and ON/OFF control valve provides a mounting point for connection to a tube of a frame of a vehicle.

7. A gas fuelling system assembly comprising:

a gaseous fuel ON/OFF control valve operable to enable fuel supply from the fuel tank to the engine when required for vehicle operation; and

a gaseous fuel pressure regulator for reducing gaseous fuel pressure between the gaseous fuel tank and the engine;

wherein said ON/OFF control valve and said gaseous pressure regulator are directly connected.

8. A vehicle comprising the gas fuelling system of any one of claims 1 to 6 or the assembly of claim 7.