GB2317202A - Manual or automatic valve actuation system for disabling one or more cylinders of an i.c. engine - Google Patents

Abstract

A method of achieving control over the number of cylinders in 'active operation' within a piston engine at times of low power requirements, eg., when stationary in traffic congestion, wherein the engine has additional valve control mechanism(s) which can be either manually or automatically operated to switch individual cylinders of the engine between active and passive operation. The mechanism is of basic cantilever construction as shown in fig 1 comprising bearing block (1) cantilever (2) push (or pull mechanism) (3) and locking device (4) optional dependant upon continuing power rating of (3) and requirement for maximum economy. The 'valve mechanism' would operate on the exhaust valve(s) of the engine, thus eliminating fuel intake to the effected cylinders. It could be operational on all but one of the cylinders at any time, dependant upon energy requirements from the engine. Hence, for a four cylinder motor, fuel economy and associated reduced CO2 emissions of 75% could be achieved. For a six cylinder motor this could rise to 83% in ideal conditions.

Description

IriTrOR VEHICLE ECoNoMy/co2 EMISSION LIMITING SYSTEM BACKGROUND TO THE INVENTION This invention relates to motor vehicle piston engines.

DESCRIPTICN The object of the invention is to provide a manual or automatic mechanism which will allow successive cylinders of the engine to be effectively and safely switched off from fuel intake capability, with a resulting fuel saving and subsequent reduction in C02 emitted. The number of cylinders so 'switched off' or operating in a passive mode, can be increased up to a point of one remaining, dependant upon the energy required to be supplied by the engine.

BACIR]ND It is well knawn that traffic congestion on the U.K.'s road network wastes vast quantities of fuel and creates unacceptable levels of C02 in the air around our cities, towns and villages notwithstanding the out-of-pocket expense of being caught up in such congestion.

Conventionally, the practice is to allow the engine to 'tick over' in such congestion in order to supply electrical power for lighting, windscreen wipers, radio, heater, window demister, plus other power consuming accessories, in any combination, dependant upon prevailing weather conditions.

This novel, simple control to achieve the above gains could be arranged such that any subsequent press of the accelerator control pedal would switch the system back to full power. The mechanism could be fitted to all cylinders of the engine and by sequencing control, any differences in engine wear would be eliminated. This, however, would assume regular and excessive road congestion.

SUMMARY OF THE INVENTION According to the invention there is provided a method of achieving a secondary valve operating mechanism for an internal combustion engine comprising: (1) Bearing block for cantilever operation (2) Cantilever operating arm (3) Push (or pull) mechanism for cantilever operation (4) Lock open and release mechanism (5) Manual or automatic operation control (6) Release sensor fran driver's accelerator control pedal Thus it can be seen that the invention provides, in effect, a power output control from the engine by means of selecting active and passive cylinders during operation. The mechanism would be of best advantage at times of heavy traffic congestion, but could also be used as an economy device once cruising speed had been acheived, for example, long distance motorway/freeway driving where the kinetic energy of the vehicle could be maintained by a lower energy source.

BRIEF DESCRIPTIQN OF THE DRAWLING Fig 1.

The drawing is a view of the 'Hamilton Valve' mechanism as applied to a typical overhead cam piston engine propulsion unit. Engines of different manufacture will have variations on this basic theme, but in all cases the mechanism will operate on the exhaust valve(s) end of the cam shaft follower(s) for overhead cam applications.

For alternative valve operating systems the basic principle of levering and locking open the exhaust valve(s) to one or more cylinders of the engine will achieve the same economy and subsequent reduction in C02 generated.

DESCRIPTION OF AN EBODIMEST OF THE INvENTIoN One overhead cam piston engine propulsion unit, installed into a typical motor vehicle, fitted with the 'Hamilton Valve' mechanism, will now be described by way of example, with reference to the accompanying drawing. Fig 1.

Basic Principle:- Holding open the exhaust valve of a rotating internal combustion engine allows the free passage of air into and out of the respective cylinder as the piston moves up and down the engine bore. This free passage of air stops the downward stroke of the piston creating a vacuum on the induction stroke, hence on a conventionally carburated/aspirated engine set-up, fuel does not get drawn into the cylinder and the respective cylinder is thus switched between active and passive operation.

In the case of an injected fuel supply, a signal from the exhaust valve control mechanism would switch the respective fuel input/output of the injector unit to avoid unwanted fuel build up on the inlet side of the engine. The result would again be a cylinder which could be switched easily between the active and passive modes of operation.

TYPICAL INsTALLATIoN Fig 1 A cantilever 1, supported by a bearing block, bearing and shaft for pivoting 2, is aligned such that one end is situated above the engine's primary cam shaft follower 8, at a point which is above the exhaust valve and associated spring and retaining mechanism 9.

The cam shaft 7, the cam shaft follower 8, the clearance adjustment mechanism 10, and the exhaust valve 9, are standard parts to the cont conventional piston engine. The electrically or hydraulically operated control cylinder 3, which is firmly mounted to the engine cylinder head or block, raises the other end of the cantilever 1 when commanded to do so by control mechanism 5. Control mechanism 5, is either an electrical or mechanical signal from the vehicle driver's control position.

Raising the end of cantilever 1, in this way produces a dowmward force on the exhaust valve mechanism 9, via the top of the cam follower. This downward force compresses the valve spring and opens the valve. Once open the basic principle as described earlier comes into operation. To cancel the effect and return the system to active operation a signal 6, is sent to the control mechanism 5, for example, by the driver depressing the engine accelerator control pedal. The control mechanism 5, switches the electrical or hydraulic control cylinder 3, to reverse cperation, cantilever 1 is lowered at the control end by means of releasing the valve spring 9, at the other end.

If electric power is used, and in some cases where hydraulic power is used, to operate the control cylinder 3, it will be necessary to conserve energy once the valve and spring has been depressed. In this case mechanism 4, which is solidly mounted to the engine cylinder head or block, will be activated once control cylinder 3 has reached its fully up position. A simple fork or locating pin will extend from mechanism 4, this mates with the raised section of cylinder 3, effectively holding the cantilever 1 in the operational position. Electrical or hydraulic power to 3, will then be switched off once mechanism 4, has locked into holding position.

cont To withdraw 4, from the holding position, the signal from the operation of the engine accelerator pedal is used to reverse the operation.

Alternative Installation A. Fig 1A The typical installation describes the valve mechanism operated by control cylinder 3, either electrically or hydraulically powered.

The alternative to this is shown within the circle Fig 1A. This shows a simple cam 12 and follower mechanism 13, which again is control led by the control mechanism 5. The cam is mounted either via bearing housings on top of the engine cylinder head and operates the cantilever directly as Fig 1, or is mounted in bearings within the main block of the engine and the cantilever is operated on the push rod principle. The effect of raising and lowering the cantilever on 1 is the same as described in the basic principle earlier. A number of cams and associated bearing blocks are used to control multiple cylinders of the engine. A cost reduced alternative is a dual cam operating on two cylinders with single control. This limits fuel economy to 50% for a four cylinder engine.

Alternative Installation B Fig 1B The typical installation describes the valve mechanism operated by control cylinder 3, either electrically or hydraulically powered.

The alternative to this is shown within the circle Fig 1B This shows a cam 14, which is mounted in suitable bearing blocks solidly attached to the cylinder head in such a position that the cam follower 15, bears down directly onto the exhaust valve end of cont the engine's primary cam follower 8. This alternative arrangement does not require the bearing block 2, cantilever arm 1 and operating cylinder 3, being a self-contained 'overhead cam' equivalent.

Control of the operation of the cam would be via the control mechanism 5 described under the typical installation and release would be, for example, by signal from the driver's engine speed accelerator control. A number of cams and associated bearing blocks are used to control multiple cylinders of the engine.

A cost reduced alternative is a dual cam operating on two cylinders with a single control. This limits fuel economy to 508 for a four cylinder engine.

Advanced Installation Vehicles with continuous monitoring of engine torque and power output requirements would use this information as imput to a fully automatic management system, thereby controlling the number of active and passive cylinders in use at any one time. This would afford maximum fuel economy and reduced C02 emissions as the circumstances of the journey changed en route. This would give full advantage of the system once the cruising speed had been attained and maximise the efficiency during waiting periods.

Claims (9)

1. A manual or automatic valve operating mechanism which will allow successive cylinders of an internal combustion engine to be effectively and safely switched from active to passive mode of operation for the purpose of fuel economy and reduced C02 emissions, regardless of driving speed or conditions, provided that sufficient energy is capable of being generated for the prevailing load.

2. A manual or automatic valve operating mechanism which will allow successive cylinders of an internal combustion engine to be effectively and safely switched off from fuel intake capability.

3. A canbustion chamber valve operating mechanism for an internal combustion engine for controlling the nlnSher of cylinders of the engine in 'active operation'. Fitted as a secondary valve operating mechanism to the exhaust valve(s) of the engine for conventional aspirated systems. Can equally be fitted to the inlet valve(s) with suitable engine management.

4. A combustion chamber valve operating mechanism for an internal combustion engine for controlling the number of cylinders of the engine in 'active cperation'. The valve control is achieved via electrically or hydraulically operated push/pull mechanism(s) FIG 1. The operational control is achieved either from within the vehicle driver's control area or automatically by engine load sensing methods.

cont CLAIMS

5. A combustion chamber valve operating mechanism for an internal combustion engine for controlling the number of cylinders of the engine in 'active operation'. Alternative valve control systems to Claim 2 above achieved via cam operation from either the cantilever mechanism described Fig 1A or directly via a secondary overhead cam and follower arrangement, as shown in Fig 1B. The cperational control is achieved either fram within the vehicle driver's control area or automatically by engine load sensing methods.

6. A valve operating mechanism substantially as described herein with reference to Figures 1, 1A, and 1B of the accompanying drawing and referred to as the 'HAMILTON VALVE' mechanism.

Amendments to the claims have been filed as follows 5. A combustion chamber valve operating mechanism for an internal combustion engine for controlling the number of cylinders of the engine in 'active operation'. Alternative valve control systems to Claim 2 above achieved via cam operation from either the cantilever mechanism described Fig 1A or directly via a secondary overhead cam and follower arrangement, as shown in Fig 1B. The cperational control is achieved either from within the vehicle driver's control area or automatically by engine load sensing methods.

6. A valve operating mechanism substantially as described herein with reference to Figures 1, 1A, and 1B of the accompanying drawing and referred to as the 'HAMILTON VALVE' mechanism.

7. A valve operating mechanism substantially as described herein with reference to figures 1, 1A and 1B of the accompanying drawing, which can be retrospectively fitted to the standard valve operating mechanism of existing piston engines.

8. A valve operating mechanism substantially as described herein with reference to figures 1, 1A and 1B of the accompanying drawing, which can be fitted at the time of manufacture, or retrospectively, to piston engines with multiple valves per cylinder.

9. A valve operating mechanism substantially as described herein with reference to figures 1, la and 1B of the accompanying drawing, capable of reducing fuel comsumption by up to 75% for a 4 cylinder engine, 808 for a 5 cylinder engine and 83% for a 6 cylinder engine, with respective reductions in C02 emissions, during periods of engine idling or low power output requirements.