Title of Invention

METHOD AND DEVICE FOR CHANGING AND GOVERNING THE COMPRESSION RATIO, VALVE TIMING & VALVE OVERLAP PERIOD OF AN INTERNAL COMBUSTION ENGINE

Abstract A device for regulating and changing the compression ratio, valve timing & valve overlap period of an internal combustion engine which includes primary cylinders that are inverted on secondary cylinders and in every primary cylinder there is a movable primary piston that is connected to the first crankshaft and in every secondary cylinder there is a movable secondary piston that is connected to the second crankshaft. Both cylinders are connected by throat. Secondary cylinder is mounted such that swirl is developed in it by throat for reducing ignition delay as fuel is injected along the air motion to enhance the atomization. The primary and secondary crankshafts are connected to each other by means of a transmission with speed ratio of 1:2. They are synchronized such that engine capacity will not vary during suction stroke. The phase difference between crankshafts will vary the clearance volume of combustion chamber, with which the variable compression ratio is achieved. Device will change the compression ratio depending upon the fuel used, engine speed and load conditions. There is also a provision for setting compression ratio at any particular value consistently by disconnecting crankshafts and setting angular position of secondary crankshaft with respect to that of primary crankshaft. Device on secondary crankshaft for changing the phase difference have the flanges with helical surface and coil spring located axially exerts thrust on them. Axial movement of the flange changes the phase difference between crankshafts. Axial movement is achieved by overcoming the axial thrust developed by spring. Combustion pressure exerted on secondary piston overcomes the spring force through crankshaft. Secondary crankshaft shares the camshaft as valve train for either inlet valve or exhaust valve or both. Phase difference between crankshafts also changes the valve timing depending upon the valve train shared by secondary crankshaft. Secondary crankshaft and camshaft for exhaust & inlet valve coupled by gear revolves opposite to each other, by changing phase difference it will vary the valve overlap period. In case of multi-cylinder engine, firing cylinder will change the valve timing of rest of the cylinders including it. Ports located at the BDC of secondary cylinder will reduce pumping losses. Exhaust gases coming from these ports are used for turbo- charging to utilize thermal energy of exhaust gases. Suction port with reed valve for secondary cylinder is exposed earlier than exhaust port. At the time of suction stroke exhaust ports are covered by piston which will expose only suction port and due to vacuum richer mixture is inhaled inside the secondary cylinder. It forms heterogeneous charge for lean burn in SI engine.
Full Text 1
FORM 2
THE PATENTS ACT,
1970 (39 of 1970)
&
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title: - Method and device for regulating and changing the compression ratio, valve timing & valve overlap period of an internal combustion engine with duel/Multifuel ability.
2.1 Ladi Dhirajkumar Dhondiram
A/P- kale, Tal- Karad, Dist- Satara, Maharashtra.
Pin-415104. Indian.
3. The following specification describes the invention and the manner in which it is to be performed

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Background of invention:-
Description of the Related Art
[001] Worldwide pressure to reduce automotive fuel consumption and C02 emissions is leading to the introduction of various new technologies for the IC engine as it fights for market share with the rest prime mover. The need for developing IC engine with high specific power output accompanied by good reliability and longer life is self evident.
[002] The internal combustion engine is small in size but is capable of outputting relatively large power and because of these advantages, the internal combustion engine is widely used as the power source of various transportations and as the power source of diverse stationary equipment and machinery. The principle of the internal combustion engine makes the compressed air-fuel mixture subjected to combustion in a combustion chamber and converts the pressure of combustion into mechanical power. Mean effective pressure is the measure of engine performance.
[003] The efficiency of a prime mover is the percentage of heat energy obtained from the fuel burning that is converted to useful mechanical energy. Indicated thermal efficiency is a term used to describe the percentage of the energy obtained from the fuel that is converted to mechanical energy within the engine even though some of this energy may not be available outside the engine due to factors such as friction within the engine and the energy used to run ancillary mechanisms needed for engine operation.
[004] All the methods of increasing power output of an engine bring with them a host of problems. For example, increasing engine speed imposes dynamic load and increased wear, thereby, reducing reliability and life. High speed also increases the pumping losses which may become unacceptable especially for part load operation.
[005] Use high pressure turbo charging result in very high peak cycle pressures and also impose higher thermal loads. Up to a certain specific output, matching the turbo charger and the engine characteristic is easy. However, the turbocharger cannot maintain good adiabatic efficiencies over wide range of pressure ratios and airflows and difficulties arise at higher specific output. The low speed torque output becomes too low to be used for certain applications such as for automotive use. Adding a positive displacement supercharger to overcome this difficulty is a complicated and costly proposal.
[006] the compression ratio of an engine is defined as the ratio of the cylinder volume at bottom dead center to the cylinder volume at top dead center. The compression ratio, which is set for engines in accordance with the prior art, represents a compromise between various objectives. For example, to achieve good cold-starting performance of the engine, the higher compression ratio is used. Theoretically it enhances the thermal efficiency of engine.
[007] However, a rise in the compression ratio of an internal combustion engine always gives rise to an increase in the friction of a real engine. In the actual state, however, the higher compression ratio undesirably heightens the potential for the occurrence of abnormal combustion called knocking. Driving the internal combustion engine in the state of knocking may damage the internal combustion engine. In the internal combustion engine with setting of a high compression ratio, especially in a driving area of high load having the high potential for the occurrence of knocking, the ignition timing is delayed from its optimum timing to prevent

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the occurrence of knocking. The delayed ignition timing effectively prevents the occurrence of
knocking but naturally lowers the output of the internal combustion engine.
[008] One method of solving the high peak pressure problem encountered when the specific
output is increased is to reduce the compression ratio at full load but at the same time keeping
the compression ratio sufficiently high for good starting and part load operation; Thus, it is
clear that a fixed compression ratio engine cannot meet these requirements of high specific
output.
[009] VCR technology could provide the key to enable exceptional efficiency at light loads
without loss of full load performance. The maximum output is obtained when the full air
capacity of engine is utilized.
[010] In the VCR engine a high compression ratio is used for good stability and low load
operation and a low compression ratio is used at full load to allow the turbocharger to boost the
intake pressures without increasing peak pressure. It should be noted that the greater volume of
clearance volume at lower compression ratio would result in increased air intake for the same
peak compression pressure and would give more power output.
Variable valve timing:-
[011] The maximum output is obtained when the full air capacity of engine is utilized. Intake valve timing has a bearing on the actual quantity of air sucked during suction stroke. It is seen that for both low and high speed engine the intake valve open 10 degree before the arrival of piston on TDC (Top Dead Center) the exhaust stroke. As piston moves to BDC fresh charge is drav n in through intake port and valve. When pistons reach BDC (Bottom Dead Center) and move in compression stroke, the inertia of the entering fresh charge tends to cause it to continue to move in cylinder. This is called ram effect. However intake valve remain open to long period, the up moving piston on the compression stroke would tend to force some of the charge, already in the cylinder, back into the intake manifold. At low speed air inertia is also low, and hence the intake valve should close relatively earlier after BDC for low speed engine. In high speed engines the charge speed is high and consequently air inertia is also high and hence the exhaust valve should close late.
[012] Exhaust valve is set to open before BDC to reduce the combustion pressure to minimize pumping losses. But opening of the exhaust valve too earlier reduces the pressure near the end of power stroke and thus cause some loss of useful work. Thus when piston is at the TDC both intake and exhaust valves are open this is called as valve overlap period. It affects the volumetric efficiency of engine. Hence it is necessary to vary the valve timing and valve overlap period as speed changes. Valve overlap period should increases as speed increases. Variable valve actuation increases the volumetric efficiency of engine with respect to the speed and intake air pressure in case of super charging and turbo charging.
[013] Stratified charge has long been used as a method to obtain lean burning in a spark-ignition engine. There are various ramifications but most have a single generic embodiment in common. A small volume separated from the main combustion chamber is supplied with a charge of fuel and air that is rich in fuel. This charge is fired with a spark and the flame from this ignites the charge in the remainder of the combustion chamber which latter charge is much leaner. In this manner it is possible to fire charges as lean as around 50-60% of stoichiometric.

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Combustion that takes place only in the small separated volume is often used to support very low torque values; around 10% of maximum. Between around 10% to around 40% the typical stratified charge engine is unstable and needs other mechanisms to appropriately throttle the engine. Stratified charge design also has some problems with efficiency as well. Near the lean limit of the stratified charge approach there is trouble firing the charge in the main combustion volume rapidly enough for operation. The slow burning results in a loss of some of the heat energy of the charge and also results in incomplete combustion as well.
[014] The use of homogenous charge compression ignition concepts has apparent benefits in substantial reduction of NOx emissions. However, two aspects of combustion control, used regularly in more conventional engines, are not available in an HCCI engine. The timing of ignition in an HCCI engine can be controlled neither indirectly by controlling the start of fuel injection, as in a direct injection engine, nor directly by controlling spark initiation, as in a spark ignition engine. Further, the rate of heat release can not be controlled via control of fuel injection, as in a direct injection engine, nor by flame propagation, as in a spark ignition engine. As a result, ongoing efforts for improving the HCCI concept include ways to control the ignition event in an HCCI engine.
[015] To overcome these problems, attempts have been made to control the compression ratio in the combustion cylinder using a secondary cylinder in communication with the combustion cylinder. By varying the position and movement of a secondary piston in the secondary cylinder, the compression ratio in the combustion cylinder can be controlled.
Advantages over existing techniques-
[016] Other techniques include the use of eccentric rings or bushings either at the lower "large" end of a connecting rod or the upper "small" end of the connecting rod for varying the effective length of the connecting rod or height of a reciprocating piston. U.S. Pat. Nos. 5,417,185, 5,562,068 and 5,960,750 and Japanese Publication JP-03092552 disclose devices that include eccentric rings. These eccentric ring devices, however, are undesirable in that each eccentric ring must be rotated 180 degrees before one of the desired operating modes or positions is engaged. As a result, locking of the eccentric ring in a proper position may not occur within an optimum period of time, thereby leaving the effective length of the device and consequently the compression ratio of an associated cylinder in an undesired intermediate state.
[017] Known techniques include using "sub-chambers" and "sub-pistons" to vary the volume of a cylinder (see, for example, U.S. Pat. Nos. 4,246,873 and 4,286,552), varying the actual dimensions of all or a portion of a piston attached to a fixed length connecting rod (see U.S. Pat. No. 5,865,092), and varying the actual length of a connecting rod (see U.S. Pat. No. 5,724,863). U.S. Pat. No. 4,516,537 entitled, "A Variable Compression System for Internal Combustion Engines" discloses a spark ignition engine in which a secondary cylinder and piston are provided to vary the compression ratio and reduce knock at low speeds and/or heavy loads, while also increasing power and fuel efficiency at high speed and/or light load.
[018] In above cases piston position is changed to vary the compression ratio but in that cases cylinder liner gets exposed to combustion and during long running of engine at lower compression ratio liner gets corroded which will reduce the life of liner and piston rings.
[019] To overcome this problem it is necessary that range and area of piston movement inside the cylinder should not be changed for all compression ratio and speed range. Piston should

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always move at fixed range and area of liner during each and every revolution to keep the liner lubricating.
[020] The invention make secondary piston moving continuously along fixed range during each revolution keeping liner lubricating. The invention also reduces the pumping losses for divided combustion chamber by providing the exhaust ports for secondary cylinders. At the end of expansion stroke exhaust gases escape through these ports which will avoid two time pumping losses as flue gases should not have to pass through communication passage to escape from main combustion chamber through exhaust manifold when exhaust valve is opened. It will reduce the Fresh charge dilution by flue gases to increase the power to weight ratio of engine.
[021] The changeover of the compression ratio set in the internal combustion engine enables the simultaneous improvement of the thermal efficiency and the maximum output, but has the drawbacks discussed below. The changeover of the setting of the compression ratio in the internal combustion engine requires some energy. Frequent changeover of the compression ratio undesirably consumes large energy and may lower the total thermal efficiency of the internal combustion engine. The changeover of the setting of the compression ratio also takes some time. Frequent changeover of the compression ratio may give the sense of discomfort to the operator of the internal combustion engine. The simple changeover of the compression ratio varies the output of the internal combustion engine and may give the sense of discomfort to the operator of the internal combustion engine. The complicated control strategy is thus required to prevent the variation in output of the internal combustion engine. A technique of eliminating such drawbacks has highly been demanded.
[022] The invention gives solution for these drawbacks by the governing the compression ratio of engine without any external interface or control system compression ratio depends only on the combustion pressure. When combustion pressure exceeds the threshold value, the governing system automatically reduces the compression ratio to maintain limited combustion pressure and avoid the knocking.
[023] A high compression contributes to an effective combustion, which in turn contributes to a high efficiency and low fuel consumption. At the same time, however, there is a need for using high octane fuel, particularly in the case of high engine loads in order to avoid uncontrolled combustion. In view of this background, it becomes evident that it can be desirable to be able to vary the compression ratio during engine operation depending on fuel quality and engine load.

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SUMMARY OF INVENTION
A device for regulating and changing the compression ratio, valve timing & valve overlap period of an internal combustion engine which includes primary cylinders that are inverted on secondary cylinders and in every primary cylinder there is a movable primary piston that is connected to the first crankshaft and in every secondary cylinder there is a movable secondary piston that is connected to the second crankshaft. Both cylinders are connected by throat. Secondary cylinder is mounted such that swirl is developed in it by throat for reducing ignition delay as fuel is injected along the air motion to enhance the atomization. The primary and secondary crankshafts are connected to each other by means of a transmission with speed ratio of 1:2. They are synchronized such that engine capacity will not vary during suction stroke. The phase difference between crankshafts will vary the clearance volume of combustion chamber, with which the variable compression ratio is achieved. Device will change the compression ratio depending upon the fuel used, engine speed and load conditions. There is also a provision for setting compression ratio at any particular value consistently by disconnecting crankshafts and setting angular position of secondary crankshaft with respect to that of primary crankshaft. Device on secondary crankshaft for changing the phase difference have the flanges with helical surface and coil spring located axially exerts thrust on them. Axial movement of the flange changes the phase difference between crankshafts. Axial movement is achieved by overcoming the axial thrust developed by spring. Combustion pressure exerted on secondary piston overcomes the spring force through crankshaft. Secondary crankshaft shares the camshaft as valve train for either inlet valve or exhaust valve or both. Phase difference between crankshafts also changes the valve timing depending upon the valve train shared by secondary crankshaft. Secondary crankshaft and camshaft for exhaust & inlet valve coupled by gear revolves opposite to each other, by changing phase difference it will vary the valve overlap period. In case of multi-cylinder engine, firing cylinder will change the valve timing of rest of the cylinders including it. Ports located at the BDC of secondary cylinder will reduce pumping losses. Exhaust gases coming from these ports are used for turbo-charging to utilize thermal energy of exhaust gases. Suction port with reed valve for secondary cylinder is exposed earlier than exhaust port. At the time of suction stroke exhaust ports are covered by piston which will expose only suction port and due to vacuum richer mixture is inhaled inside the secondary cylinder. It forms heterogeneous charge for lean bum in SI engine.

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BRIEF DESCRIPTION OF DRAWINGS
fig 1 shows the single cylinder internal combustion engine with device for regulating and changing the compression ratio, valve timing & valve overlap period of an internal combustion engine according to the present invention; and
FIG. 2 shows top view of device in which secondary crankshaft with extension for phase shift control geared with camshaft.
Fig.3 shows divided type combustion chamber geometry with suction ports timing advanced than exhaust ports at BDC for secondary cylinders.
DETAILED DESCRIPTION OF DRAWINGS
FIG. 1 shows, in a side view in partial cross-section, an internal combustion engine with an
engine primary cylinder 1 that respectively communicate with secondary cylinder 7 arranged
in the cylinder head 5 of the internal combustion engine . In primary cylinder 1, primary piston
2 is reciprocating arranged. By means of primary connecting rod 3 is connected to a first
crankshaft 4. In secondary cylinder 7, secondary piston 6 is reciprocatingly arranged and is
connected to the second crankshaft 9 by means of secondary connecting rods 8 the first
crankshaft 4 is mounted in bearings in the engine, and the secondary crankshaft 9 is mounted
in bearings in the cylinder head 5. The crankshafts 4, 9 are connected to each other by means
of a transmission 16 that runs over a first 14 and a second 15 driving wheel. The size of the
driving wheels 14, 15 are chosen so that the second crankshaft 9 rotates with half the rpm's of
the first crankshaft 4. The second driving wheels 15 with helical profile flange matched with
flange 17 of the device for phase shift control that is arranged on the cylinder head 5. There is
secondary crankshaft extension 19 with stopper 18 where spring is mounted to exert pressure
on flanges.
With reference to FIG. 2, a preferred embodiment of the means or device for phase shift
control will now be described. In the embodiment shown, the second driving wheel 15 is
mounted on head 5. The driving wheel 15 is in addition equipped with a helical surface flange
17 meshing for rotational connection, which interacts with the corresponding stopper 18 on a
crankshaft extension to rest the spring. Flange 17 and secondary wheel 15 with helical surface
meshing at 20.
Secondary crankshaft 9 with gear 13 is meshed with camshaft through gear wheel 12. Crankshaft 9 with cam 23 will operate exhaust valve while cams 21, 22 on camshaft to operate inlate valves. Both these shaft are mounted in head 5 on bearing support. Between the flange 17 and stopper 18 spring is mounted which is configured to absorb axial forces that will arise as a result of the torque transferred over the helical portions 20.

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Fig. 3 shows divided type combustion chamber geometry with suction ports timing advanced than exhaust ports at BDC for secondary cylinders, a method for operating an internal combustion engine is provided with reciprocating a primary piston 2 within a combustion cylinder 2 reciprocating a secondary piston within a secondary cylinder, combustible fuel to the combustion cylinder; communicating fluid flow between the secondary cylinder 7 and the combustion cylinder, the communicating fluid flow step being carried out through a communication port 10 having an opening in the combustion chamber and an opening in the secondary chamber, each the openings being narrower than the cylinders. Secondary cylinder is mounted eccentric so that swirl is developed in it by throat 10. Exhaust ports 23, 29 located at the BDC of cylinder will reduce pumping losses for divided combustion chamber. At the end of expansion stroke exhaust gases escape through these ports which will avoid two time pumping losses as flue gases should not have to pass through communication passage 10 to escape from main combustion chamber 1. Suction port 25 with reed valve 26 for secondary cylinder is exposed earlier than exhaust ports 23, 29 and at the time of suction stroke for primary cylinder exhaust ports are covered by piston which will expose only suction port 25 and due to vacuum richer mixture is inhaled for heterogeneous charge for lean burn in SI engine through intake manifold 28. While reed valve 26 in manifold does not allow the flue gases escape through intake manifold at the end of expansion stroke.
The invention is not limited to that which has been described above; it should be appreciated that other embodiments are also possible. This invention may apply for multicylinder engines with maintaining the synchronization between secondary and primary crankshafts.

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DETAIL DESCRIPTION OF INVENTION
[024] In aspect of the invention, a method for operating an internal combustion engine is provided with steps of reciprocating a primary piston within a combustion cylinder having an end; reciprocating a secondary piston within a secondary cylinder adjacent the end, the reciprocating step being carried out such that the secondary piston has a position within the secondary cylinder which is dependent upon a position of the primary piston within the combustion cylinder; providing a combustible fuel to the combustion cylinder; communicating fluid flow between the secondary cylinder and the combustion cylinder, the communicating fluid flow step being carried out through a communication port having an opening in the combustion chamber and an opening in the secondary chamber, each the openings being narrower than the cylinders communicating port dimensions determine the fluid velocity inside the combustion chamber which will support the atomization of fuel depending on the fuel properties. In each primary cylinder, a primary piston is connected to a first crankshaft and is arranged to carry out back and forth movement. In a corresponding way, in each secondary cylinder there is a secondary piston connected to a second crankshaft, the secondary piston also being arranged to carry out back and forth movement. Between the first and second crankshafts, there is arranged transmission and a device for phase angle shift between the shafts, with the purpose of obtaining a compression ratio that depends on the current fuel and load conditions of the engine. Controlling commencement of a combustion event in the combustion cylinder through control of the position of the secondary piston.
[025] To rate a fuel, the engine is set to an appropriate compression ratio by disconnecting two crankshaft and secondary piston is set at fixed position by locking crankshaft and engine is run at fixed compression ratio that will produce a knock of about 50 on the knock meter for the sample when the air-fuel ratio is adjusted on the carburetor bowl to obtain maximum knock. Normal heptane and iso-octane are known as primary reference fuels.
[026] Two blends of these are made, one that is one octane number above the expected rating, and another that is one octane number below the expected rating. These are placed in different bowls, and are also rated with each air-fuel ratio being adjusted for maximum knock. The higher octane reference fuel should produce a reading around 30-40, and the lower reference fuel should produce a reading of 60-70. The sample is again tested, and if it does not fit between the references fuels, further reference fuels are prepared, and the engine readjusted to obtain the required knock. The actual fuel rating is interpolated from the knock meter readings. [027] Engines in accordance with the invention accomplish the above objectives by increasing the compression ratio as the torque demanded of the engine is decreased throughout the engine's throttling range. As the compression ratio is raised the engine simultaneously provides for a leaner burning of the fuel ingested into the engine using a method of separated charge combustion. The combination of higher compression ratio together with leaner burning raises the efficiency of the engine in situations during which torque demanded of the engine is less than maximum. Since practically all applications of prime movers perform the bulk of their duties at these lower torque values the overall efficiency of systems using the inventive approach is equally increased.
[028] Engine will update itself depending on the fuel used or a blend used with multi fuel ability. There is room to tolerate the fuel quality or blends. Governing system will change the

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compression ratio depending on the energy released and combustion pressure. Engines in accordance with the invention also include subsystems that enable the basic engine to perform with increased efficiency and allow the design to be smaller and lighter than engines now in common usage by downsizing and down speeding.
Variable Valve Timing and valve Overlap Period
[029] In the case of an internal combustion engine with a turbocharger, at relatively high engine speeds, at which the turbocharger is completely active, the effect of the reduced chamber volume is compensated for by higher charging pressure when the inlet valves are closing. However, this compensation does not function at lower engine speeds, at which the turbocharger does not produce a sufficient charging pressure. According to the proposed configuration of the engine timing unit, this undesirable drop in engine torque is combated by adjusting the delay in the closing of the inlet valve being continuously varied as a function of the engine speed, the engine torque and/or the charging pressure of the turbocharger. In this case, at low engine speeds and low engine torques, IVC is delayed to produce quiet combustion with low emissions. On the other hand, at low speeds and full torque, IVC is delayed to a lesser extent to maximize the volumetric efficiency and the torque. Furthermore, the invention relates to a method for controlling a engine having a turbocharger, in which to vary the compression ratio the closing of at least one inlet valve is delayed. The method is distinguished by the fact that at a low engine speed the closing of the inlet valves is delayed to a lesser extent as the engine load increases to ensure a constant engine output. This method, in the manner which has been explained above, takes into account the fact that, at low engine speeds, the turbocharger can compensate for the drop in torque by a delayed IVC rather than by an increased charging pressure. Thus, if a higher engine output is demanded, the delay in IVC is reduced accordingly.
[030] The inventor of the present invention recognizes that a engine haying at least one bank of cylinders with at least one inlet valve and at least one exhaust valve per cylinder having a secondary crankshaft for the inlet valve controlling the opening of the inlet valve, a second camshaft for thee exhaust valve controlling the closing time of the inlet valve, and a camshaft phasing mechanism coupled to the secondary crankshaft. Secondary crankshaft shares the camshaft as valve train for either inlet valve or exhaust valve or both which is rotating at half of the speed of primary crankshaft. Phase differences between two crankshafts also change the valve timing depending upon the valve train shared by secondary crankshaft. Two separate cams on separate shafts for inlet & exhaust valve connected by gear revolves opposite to each other, it will vary the valve overlap period. In case of multi-cylinder engine, firing cylinder will change the valve timing of rest of the cylinders including it. Ports located at the BDC of cylinders will reduce pumping losses. Exhaust gases coming from these ports can be used for turbo charging to utilize thermal energy of exhaust gases.
[031] By controlling the closing of the inlet valves (IVC) of all the cylinders of a cylinder bank by a dedicated, secondary crankshaft which is provided with a phase shifter, it is possible to set a delay in the closing of the inlet valves. A delay of this type reduces the effective compression ratio when the engine is operating. This provides an advantage when the engine is warmed up

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to reduce the production of noise and the emissions of pollutants. At the same time, the first camshaft, which is separate from the second camshaft, ensures that the opening of the inlet valves can take place independently of the closing. Therefore, there is no disadvantageous change in the opening of the inlet valves associated with a delay in the closing of the inlet valves. Furthermore, the proposed engine has a relatively simple structure, since it is based on inexpensive, compact mechanical components.
[032] The phase-shifting mechanism of the secondary crankshaft is preferably designed to delay the closing time by up to 60. degree. Axial displacement will determine the change in phase difference. After the usual inlet closing (IVC). A delay of this extent is sufficient for the desired range in compression ratio and can still be achieved relatively successfully mechanically. According to a preferred configuration, the secondary crankshaft and camshaft are arranged parallel and closely adjacent to one another. In this way, it is possible to ensure that both camshaft and crankshaft are able to act on the both inlet and exhaust valves and take up relatively little space.
Combustion chamber geometry and combustion chemistry
[033] Combustion chamber is divided type supporting the heterogeneous charge for SI engine for lean burn to reduce the fuel consumption and emissions. The VCRC engine accomplishes a reduction in both oxides of nitrogen and unburned hydrocarbons by a method of burning in two phases. First the fuel is burned in a uniformly mixed fuel-rich environment which includes some EGR. This mode of burning minimizes the creation of oxides of nitrogen. The initial burning is immediately followed by a completion of the burning process in an environment in which air is present in excessive quantities when compared with that amount needed to completely burn the fuel.
[034] Thus in the VCRC internal combustion engine the compression ratio and the amount of fuel burned (the charge') during each firing cycle are simultaneously varied in response to torque demanded of the engine. A decrease in torque demand is accompanied by an increase in the engine's compression ratio and a reduced fuel flow. The relationship of compression ratio and fuel supplied is varied in such a manner as to keep the peak pressure in the engine's combustion process at a nearly constant level for all torque demands at a given speed. The relationship of the two parameters of compression ratio and fuel-air ratio are also varied as speed of the engine changes so as to raise the combustion peak pressure with an increase in engine speed.
[035] The VCRC engine's method of combustion offers other advantages also by separating the combustion into two phases; an initial combustion of the bulk of fuel and air in an fuel over-rich environment followed by a completion of combustion in a high temperature fuel-lean mixture, the problems of detonation are almost entirely eliminated. Detonation, or knock as it is colloquially called, is an explosion of the last 5% or less of the bulk fuel-air mixture. An overly rapid rise in pressure brought about by the initial combustion of the fuel-air mixture creates a pressure wave that compresses an isolated mixture of fuel and air and the accompanying rise in temperature of this isolated mixture creates an explosive situation

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wherein this mixture spontaneously combusts giving the resultant explosive increase in pressure and noise. In the VCRC engine the "end gas", as this isolated fuel air mixture is called in internal combustion engine engineering, consists only of air. Thus the concept of octane requirements for the fuel used are moved so far off the engine's boundary limits as to be of essentially no import. The fuel for a VCRC engine can be most any mixture of fuel oil, of a low octane number, and gasoline with a higher value. The need for a high cetane number, necessary for smooth combustion in compression ignition engines, is equally unimportant.
[036] In the engine configurations fuel is injected into a volume separated, by a short gas passage or passages, from the main cylinder volume. In this volume about 50% of the total air used by the engine is reduced by burning of the injected fuel in a manner that can be considered conventional compression-ignition engine spray combustion. Subsequently the hot mixture of fuel and combustion products is combined with the remaining air in the rest of the cylinder volume. The process allows up to 90% of the air to be burned (in the Comet Mark III) at full throttle showing that the process can be used to burn fuel at any level of leanness as long as all the fuel and some air are mixed in a fuel-rich burning amalgam in the initial phase of the burning process. The entire amount of fuel to be burned is contained in a separate variable volume together with around 60% or less of the air that is to be reduced by the combustion process. In this manner the difficulties of stratified charge burning are not present. The bulk of the fuel is burned at rapid velocity in the initial phase of combustion.

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I claim
1. A device for regulating and changing the compression ratio, valve timing & valve overlap
period of an internal combustion engine which includes primary cylinders that are inverted on
secondary cylinders and in every primary cylinder there is a movable primary piston that is
connected to the first crankshaft and in every secondary cylinder there is a movable secondary
piston that is connected to the second crankshaft. Both cylinders are connected by throat.
Secondary cylinder is mounted such that swirl is developed in it by throat for reducing ignition
delay as fuel is injected along the air motion to enhance the atomization. The primary and
secondary crankshafts are connected to each other by means of a transmission with speed ratio
of 1:2. They are synchronized such that engine capacity will not vary during suction stroke.
The phase difference between crankshafts will vary the clearance volume of combustion
chamber, with which the variable compression ratio is achieved. Device will change the
compression ratio depending upon the fuel used, engine speed and load conditions. There is
also a provision for setting compression ratio at any particular value consistently by
disconnecting crankshafts and setting angular position of secondary crankshaft with respect to
that of primary crankshaft. Device on secondary crankshaft for changing the phase difference
have the flanges with helical surface and coil spring located axially exerts thrust on them.
Axial movement of the flange changes the phase difference between crankshafts. Axial
movement is achieved by overcoming the axial thrust developed by spring. Combustion
pressure exerted on secondary piston overcomes the spring force through crankshaft.
Secondary crankshaft shares the camshaft as valve train for either inlet valve or exhaust valve
or both. Phase difference between crankshafts also changes the valve timing depending upon
the valve train shared by secondary crankshaft. Secondary crankshaft and camshaft for exhaust
& inlet valve coupled by gear revolves opposite to each other, by changing phase difference it
will vary the valve overlap period. In case of multi-cylinder engine, firing cylinder will change
the valve timing of rest of the cylinders including it. Ports located at the BDC of secondary
cylinder will reduce pumping losses. Exhaust gases coming from these ports are used for turbo-
charging to utilize thermal energy of exhaust gases. Suction port with reed valve for secondary
cylinder is exposed earlier than exhaust port. At the time of suction stroke exhaust ports are
covered by piston which will expose only suction port and due to vacuum richer mixture is
inhaled inside the secondary cylinder. It forms heterogeneous charge for lean burn in SI
engine.
2. The device according to claim 1, a method for operating an internal combustion engine is
provided with reciprocating a primary piston within a combustion cylinder; reciprocating a
secondary piston within a secondary cylinder, the reciprocating step being carried out such that
the secondary piston has a position within the secondary cylinder which is dependent upon a
position of the primary piston within the combustion cylinder; providing a combustible fuel to
the combustion cylinder; communicating fluid flow between the secondary cylinder and the
^combustion cylinder, the communicating fluid flow step being carried out through a
communication port having an opening in the combustion chamber and an opening in the secondary chamber, each the openings being narrower than the cylinders, commencement of a combustion event is controlled in the combustion cylinder through control of the position of the secondary piston. Secondary cylinder is mounted eccentric so that swirl is developed in it

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by throat for reducing ignition delay as fuel is injected along air motion to enhance the atomization in CI engine.
3. The device according to claim 1,between the first and second crankshafts, there is arranged transmission and a device for phase angle shift between the shafts, with the purpose of obtaining a compression ratio that depends on the current load of the engine first and second crankshaft being connected to each other by means of a transmission, secondary crank shaft rotates at the half of the speed of primary crank shaft and a crankshaft extension intended for said phase angle control, which is fixedly connected against rotation to one of said crankshafts and rotationally attached to the second of said crankshafts.
4. The device according to claim 3, wherein said secondary crankshaft extension exhibits a second portion equipped with flange with same helical surface profile to match each other for said rotational connection. Flanges loaded with coil spring located axially exert thrust on them. Spring loaded flanges are arranged for obtaining axial displacement of the crankshaft extension in a first direction and in a second direction. Axial movement of the flange changes the phase difference between two crankshafts will change the compression ratio of engine.
5. The method according the claim 4, axial movement of flanges is achieved by overcoming the axial thrust developed by spring. . When combustion pressure exceeds threshold value then it will act on both pistons and overcome the spring force through crankshafts. Spring stiffness determines the speed -compression ratio characteristics of engine which is evaluated from combustion pressure, knocking intensity speed and load conditions of engine.
6. The method according the claim 1, to rate a fuel for octane & cetane number, the engine is set to an appropriate compression ratio by disconnecting two crankshafts and secondary piston is set at fixed position by locking secondary crankshaft. Secondary piston position is set according to the fuel used. When engine is run for that compression ratio that will produce a knock of about 50 on the knock meter for the sample when the air-fuel ratio is adjusted on the carburetor bowl to obtain maximum knock. Normal heptane and iso-octane are known as primary reference fuels. From the knocking intensity of fuel maximum allowable compression ratio is determined for that particular fuel or fuel blends used.
7. The device according to claim 1, Secondary crankshaft shares the camshaft as valve train for either inlet valve or exhaust valve or both which is rotating at half of the speed of primary crankshaft. Phase differences between crankshafts also change the valve timing depending upon the valve train shared by secondary crankshaft. In case of secondary crankshaft and camshaft revolving in same direction, it will only change the valve timing of valve which is shared by secondary crankshaft. Device which includes Secondary crankshaft and camshaft for exhaust & inlet valve coupled by gear revolves opposite to each other will vary the valve overlap period. In case of multi-cylinder engine, firing cylinder will change the valve timing of rest of the cylinders including it.

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8. The method according to claim 1, ports located at the BDC of cylinders will reduce pumping losses for divided combustion chamber by providing the exhaust ports for secondary cylinders. At the end of expansion stroke exhaust gases escape through these ports which will avoid two time pumping losses as flue gases should not have to pass through communication passage to escape from main combustion chamber through exhaust manifold during exhaust stroke. Exhaust gases coming from these ports can be used for turbo charging to utilize thermal energy of exhaust gases.
9. The device according the claim 7, primary and secondary crankshafts are connected such that secondary crankshaft is advanced by few degrees with respect to that of the primary crankshaft. This advanced time period is greater than that of the exhaust valve open period of the ports provided at BDC of secondary cylinders so that it gives overlapped exhaust valve open period to that of the primary crankshaft for primary cylinders.
10. The device according the claim 8, Suction port with reed valve for secondary cylinder is
exposed earlier than exhaust port and at the time of suction stroke for primary cylinder exhaust
ports are covered by piston which will expose only suction port and due to vacuum richer
mixture is inhaled for heterogeneous charge for lean burn in SI engine. While reed valve in
manifold does not allow the flue gases escape through intake manifold at the end of expansion
stroke. Fuel injected or inhaled in secondary cylinder richer than primary cylinder which will
make heterogeneous charge for duel fuel ability. Piolet fuel is injected in secondary cylinder
initiate the ignition and after the ignition flame travels like SI engine. Due to this flame lean
mixture in main chamber can be ignited to achieve low fuel consumption and low emissions.
Dated this 10th day of April 2006
Signature
Ladi Dhirajkumar Dhondiram

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Title: - Method and device for regulating and changing the compression ratio, valve timing & valve overlap period of an internal combustion engine with duel/Multifuel ability.
This invention relates to enhancing efficiency, power output and expansion ratio of internal combustion engine with variable compression ratio mechanism, variable valve timing and variable valve overlap period. It also gives duel/Multifuel ability and the octane & cetane number determination of fuel from maximum knocking intensity.
Abstract
The internal combustion engine includes two sets of primary and secondary cylinders. Secondary cylinders are inverted on primary cylinders and in every cylinder there is a movable piston that is connected to the crankshaft. Both primary and secondary cylinders are connected by throat giving divided type combustion chamber. The pumping losses for divided combustion chamber are minimized by providing the exhaust ports for secondary cylinders. The first and second crankshafts are connected to each other by means of a transmission with speed ratio of 1:2. The phase difference between crankshafts will change the compression ratio by changing piston positions with that of the TDC (Top Dead Center) of each other. Compression ratio is set according to fuel used, speed and load conditions of engine. Device on secondary crankshaft to change phase difference have the flanges with helical surface. Coil spring located axially exerts pressure on them. Axial movement of the flange changes the phase difference between crankshafts. Secondary crankshaft also shares the camshaft as valve train for either inlet valve or exhaust valve or both. Phase differences between primary and secondary crankshafts also change the valve timing and valve overlap period depending upon the valve train shared by secondary crankshaft. In case of multi-cylinder engine firing cylinder will change the valve timing of rest of the cylinders including it.
LADIDHIRAJKUMAR DHONDIRAM

Documents:

565-mum-2006-abstract(3-9-2007).doc

565-mum-2006-abstract(3-9-2007).pdf

565-mum-2006-abstract-1.jpg

565-mum-2006-cancelled pages(3-9-2007).pdf

565-mum-2006-claims(granted)-(3-9-2007).doc

565-mum-2006-claims(granted)-(3-9-2007).pdf

565-mum-2006-claims.pdf

565-mum-2006-correspondence(ipo)-(21-9-2007).pdf

565-mum-2006-correspondence-received.pdf

565-mum-2006-description (complete).pdf

565-mum-2006-drawing(3-9-2007).pdf

565-mum-2006-form 1(10-4-2006).pdf

565-mum-2006-form 1(3-9-2007).pdf

565-mum-2006-form 13(23-8-2006).pdf

565-mum-2006-form 18(23-8-2006).pdf

565-mum-2006-form 2(granted)-(3-9-2007).doc

565-mum-2006-form 2(granted)-(3-9-2007).pdf

565-mum-2006-form 3(10-4-2006).pdf

565-mum-2006-form 8(26-9-2007).pdf

565-mum-2006-form 9(10-4-2006).pdf

565-mum-2006-form-1.pdf

565-mum-2006-form-2.doc

565-mum-2006-form-2.pdf

565-mum-2006-form-3.pdf

565-mum-2006-form-9.pdf

abstract1.jpg


Patent Number 210279
Indian Patent Application Number 565/MUM/2006
PG Journal Number 26/2008
Publication Date 27-Jun-2008
Grant Date 26-Sep-2007
Date of Filing 10-Apr-2006
Name of Patentee LADI DHIRAJKUMAR DHONDIRAM
Applicant Address
Inventors:
# Inventor's Name Inventor's Address
1 1)LADI DHIRAJKUMAR DHONDIRAM 2)CHAVAN SHRIRANG PANDURANG A/P-kale, Tal-karad, Dist-satara, Maharashtra, Pin-415104, Indian. DEPT. OF MECHANICAL ENGG. WALCHAND COLLEGE ENGG. VISHRAMBAUG, SANGLI.
2 LADI DHIRAJKUMAR DHONDIRAM A/P-kALE, TAL-kARAD, DIST-SATARA
3 Chavan Shrirang Pandurang
PCT International Classification Number F01L 1/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA