GB1570977A

GB1570977A - Internal combustion engine including devices for agitating the air-fuel mixture

Info

Publication number: GB1570977A
Application number: GB22773/79A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-09-30
Filing date: 1976-09-30
Publication date: 1980-07-09

Description

(54) INTERNAL COMBUSTION ENGINE INCLUDING DEVICES FOR AGITATING THE AIR-FUEL MIXTURE (71) I, ONG SIAK-HOO, a citizen of Singapore, residing at 3-17-21, Koishikawa, Bunkyo-ku, Tokyo, Japan, do hereby declare the invention, for which I pray that a Patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to an internal combustion engine having two inlet valves per cylinder, and fitted with devices which improve the combustion efficiency of the engine by simultaneously rotating different portions of the air-fuel mixture entering the cylinders in different directions.

The air-fuel mixture of an internal combustion engine may be formed by a carburettor or a fuel injecting device. Particles of fuel, when entering the combustion chamber of an engine, are not small enough to ensure complete combustion. There are many devices and methods which are intended to give better mixing of the mixture before combustion. One type of device is a static device for scattering the particles of fuel. However, devices of the static device type do not give good performance under all running conditions. Some give poor acceleration but good level of CO in the exhaust gases at idle like the onedirection-swirl-generating device, fixed under the carburettor. Others give low power output, such as the metal mesh also fixed in the inlet manifold passage.

According to the invention we provide an internal combustion engine having a combustion chamber, and two inlet passages provided with inlet valves for introducing an air-fuel mixture into the combustion chamber, wherein there is provided in each inlet passage adjacent the valve seat a device comprising fins on the inner circumference of an annular body angled to rotate the air-fuel mixture passing through that valve, the devices being arranged so that different portions of the air-fuel mixture entering the combustion chamber are rotated in opposite directions.

These swirls may be generated by using devices in the form of circular rings, portions of which are partially cut out and bent inwards, for example by a press process from a metal sheet, to form the fins.

The fins of each device may be arranged into groups. In this case, certain fins of the same group may be angled so that they deflect the air-fuel mixture in either a clockwise or anti-clockwise direction, while certain fins of neighbouring groups may be oppositely angled so as to deflect the mixture in the opposite direction. These are called "directing fins." A pair of neighbouring directing fins of different groups and angled in opposite directions so that they face one another are called a "concentrating pair", while a pair of directing fins of opposite groups and angled in opposite directions so that they are facing away from each other are called a "separating pair." A second type of fin which may be provided is called a "centering fin" and this directs the flow towards the center of the device.Devices of this type having groups of fins which divide the air-fuel mixture into two portions, and rotate the portions in opposite directions are described and claimed in our copending application no. 40640/76 (Serial No. 1 568.243).

Many types of swirl can be generated by selecting suitable designs and combinations of the above mentioned fins and fin pairings. When the mixture passes through a device with the fins arranged in groupsas described above, the fins of the device change the direction of flow with the result that different portions of the mixture are deflected towards the center of the device and rotated in opposite directions thus forming multiple swirls.

When the devices are fixed at a position near the inlet valve, complex turbulences are formed inside the combustion chamber.

The flow may be arranged to clean the sparking plug electrodes, and gives a fast speed of flame after ignition, thus giving better fuel consumption, high power and a low-pollution exhaust.

The fins may be so arranged that the two separate swirls formed by each device are directed towards the sparking plug.

In the internal combustion engine of the present invention, there may be formed double swirls inside the combustion chamber by two swirl-generating devices associated with two separate inlet valves for the combustion chamber. Each device has fins for rotating the mixture in a different direction. Swirls generated by the two devices rotate in opposite directions towards the center of the combustion chamber. If the fins of the devices are arranged so that the flow of gas is towards the sparking plug or plugs, it cleans the plug or plugs and permits a smooth spread of flame. If two sparking plugs are used, the arrangement of flow from each inlet valve may be directed towards a different plug.

Alternatively, an internal combustion engine having a combustion chamber with two inlet valves may be provided with a pair of double-swirl devices, each being located near a different inlet valve. In that case each device has two groups of fins, which divide the air-fuel mixture into two portions, and rotate the two portions in opposite directions. In this case the flow of gas from each inlet valve may be directed towards the plug or plugs.

The invention is applicable to all internal combustion engines having two inlet valves per combustion chamber. It is especially important to mention that the present invention may be applied to modern lean-burn internal combustion engines, which operate on a lean air-fuel mixture, for example the auxiliary combustion chamber stratified charge engine, the turbulence generating pot system, and others.

The present invention gives a more homogeneous air-fuel mixture for a lean-burn engine, i.e. an engine capable of burning an air-fuel mixture having an air-fuel ratio greater than 15:1 under normal working conditions, thus improving performance, power, output, fuel consumption arid reducing the content of pollutants in the exhaust.

Some embodiments of the invention will now be described by way of Example, and with reference to the accomyanying drawings.

Figure 1 shows an engine embodying the present invention, where two swirlgenerating devices 1 are arranged respectively near the two inlet valves of the engine. Each cylinder 8 of the engine has a piston 9 and two air-fuel mixture inlet passages 6, each having an inlet valve 4.

The engine has a single exhaust valve 5 leading to an exhaust passage 7. It has a single spark plug 14. Each swirl device generates a single swirl in the direction of the arrow R.

Figure 2 and 3 show the cylinder heads of two engines embodying the present invention, in which the flow of gas is directed from the inlet ports 11 towards the sparking plug or plugs 14 in the combustion chamber 15 by two single swirl generating devices having fins 3. The cylinder has a single exhaust port 10. These embodiments give very strong turbulence to two independent swirls S directed towards the plug or plugs 14 in the directions R so that very low fuel consumption of the engines can be attained under all operating conditions.

Figures 4 and 5 show the cylinder heads of two further engines embodying the present invention in which the flow of gas is also directed from the inlet ports 11 towards the plug or plugs 14 by two doubleswirl-generating devices. The double swirls are indicated by the arrows S.

WHAT WE CLAIM IS: 1. An internal combustion engine having a combustion chamber and two inlet passages provided with inlet valves for introducing an air-fuel mixture into the combustion chamber, wherein there is provided in each inlet passage adjacent the valve seat a device comprising fins on the inner circumference of an annular body angled to rotate the air-fuel mixture passing through that valve, the devices being arranged so that different portions of the air-fuel mixture entering the combustion chamber are rotated in opposite directions.

2. An internal combustion engine according to Claim 1, wherein each device rotates the air-fuel mixture in a single direction.

3. An internal combustion engine according to Claim 1, wherein each device causes two portions of the air-fuel mixture passing through it to rotate in opposite directions.

4. An internal combustion engine according to any preceding claim wherein in operation the flow mixture from the inlet valves is directed towards a sparking plug or plugs in the combustion chamber.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. near the inlet valve, complex turbulences are formed inside the combustion chamber. The flow may be arranged to clean the sparking plug electrodes, and gives a fast speed of flame after ignition, thus giving better fuel consumption, high power and a low-pollution exhaust. The fins may be so arranged that the two separate swirls formed by each device are directed towards the sparking plug. In the internal combustion engine of the present invention, there may be formed double swirls inside the combustion chamber by two swirl-generating devices associated with two separate inlet valves for the combustion chamber. Each device has fins for rotating the mixture in a different direction. Swirls generated by the two devices rotate in opposite directions towards the center of the combustion chamber. If the fins of the devices are arranged so that the flow of gas is towards the sparking plug or plugs, it cleans the plug or plugs and permits a smooth spread of flame. If two sparking plugs are used, the arrangement of flow from each inlet valve may be directed towards a different plug. Alternatively, an internal combustion engine having a combustion chamber with two inlet valves may be provided with a pair of double-swirl devices, each being located near a different inlet valve. In that case each device has two groups of fins, which divide the air-fuel mixture into two portions, and rotate the two portions in opposite directions. In this case the flow of gas from each inlet valve may be directed towards the plug or plugs. The invention is applicable to all internal combustion engines having two inlet valves per combustion chamber. It is especially important to mention that the present invention may be applied to modern lean-burn internal combustion engines, which operate on a lean air-fuel mixture, for example the auxiliary combustion chamber stratified charge engine, the turbulence generating pot system, and others. The present invention gives a more homogeneous air-fuel mixture for a lean-burn engine, i.e. an engine capable of burning an air-fuel mixture having an air-fuel ratio greater than 15:1 under normal working conditions, thus improving performance, power, output, fuel consumption arid reducing the content of pollutants in the exhaust. Some embodiments of the invention will now be described by way of Example, and with reference to the accomyanying drawings. Figure 1 shows an engine embodying the present invention, where two swirlgenerating devices 1 are arranged respectively near the two inlet valves of the engine. Each cylinder 8 of the engine has a piston 9 and two air-fuel mixture inlet passages 6, each having an inlet valve 4. The engine has a single exhaust valve 5 leading to an exhaust passage 7. It has a single spark plug 14. Each swirl device generates a single swirl in the direction of the arrow R. Figure 2 and 3 show the cylinder heads of two engines embodying the present invention, in which the flow of gas is directed from the inlet ports 11 towards the sparking plug or plugs 14 in the combustion chamber 15 by two single swirl generating devices having fins 3. The cylinder has a single exhaust port 10. These embodiments give very strong turbulence to two independent swirls S directed towards the plug or plugs 14 in the directions R so that very low fuel consumption of the engines can be attained under all operating conditions. Figures 4 and 5 show the cylinder heads of two further engines embodying the present invention in which the flow of gas is also directed from the inlet ports 11 towards the plug or plugs 14 by two doubleswirl-generating devices. The double swirls are indicated by the arrows S. WHAT WE CLAIM IS:

1. An internal combustion engine having a combustion chamber and two inlet passages provided with inlet valves for introducing an air-fuel mixture into the combustion chamber, wherein there is provided in each inlet passage adjacent the valve seat a device comprising fins on the inner circumference of an annular body angled to rotate the air-fuel mixture passing through that valve, the devices being arranged so that different portions of the air-fuel mixture entering the combustion chamber are rotated in opposite directions.