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EP-4193050-B1 - INTERNAL COMBUSTION ENGINE OPTIMISATION SYSTEM AND METHOD

EP4193050B1EP 4193050 B1EP4193050 B1EP 4193050B1EP-4193050-B1

Inventors

  • HART, BARRY

Dates

Publication Date
20260513
Application Date
20210809

Claims (15)

  1. A method of controlling a throttle for an internal combustion engine (210; 310), to enable the internal combustion engine to operate at a high compression ratio, whereby the engine is operable to compress an ingested fuel air mixture up to a predetermined compression pressure threshold, at which, if the ingested fuel air mixture was permitted to exceed the threshold, damage to the engine would occur by knocking or pinking, the method comprising the steps of: receiving a throttle signal, the throttle signal operable to open the throttle to a first position; determining whether opening the throttle to the first position will cause the ingested fuel air mixture to exceed the predetermined compression pressure threshold by comparing a performance demand of the first throttle position with predetermined map data that indicates safe/unsafe running conditions of the engine; and in response to making a determination that opening the throttle to the first position will cause damage to the internal combustion engine, modifying the throttle signal to open the throttle to a second position, the second position of the throttle having been determined to open the throttle to a position that will not cause damage to the internal combustion engine by knocking or pinking.
  2. The method of claim 1 wherein the predetermined map data are generated by measuring and determining conditions of the engine that cause knocking or pinking.
  3. The method of any preceding claim wherein the step of determining comprises using one or more calculations of current torque, projected torque and/or brake mean effective pressure (BMEP) for the internal combustion engine.
  4. The method of any preceding claim wherein the throttle signal is received from a throttle control (350) and optionally, the throttle control is an accelerator pedal (330).
  5. The method of any preceding claim for use with an internal combustion engine arrangement further comprising a second throttle, wherein the throttle is operable to be opened to a first or second position to restrict the airflow to the second throttle, optionally wherein the throttle and the second throttle are configured in a series arrangement.
  6. The method of any preceding claim further comprising one or more sensors wherein the one or more sensors provide data on the internal combustion engine and wherein the data is used to make the determination in the step of determining.
  7. The method of any preceding claim wherein modifying the throttle signal comprises generating a second throttle signal and controlling a further throttle using the second throttle signal.
  8. A controller (220) operable to modify a throttle signal for an internal combustion engine, the controller operable to modify the throttle signal using the method of any of claims 1 to 7 and optionally the controller comprises an engine control unit.
  9. A throttle assembly comprising a throttle, a stop and a controller according to claim 8, the stop operable to restrict a maximum opening position of the throttle to a predetermined opening position wherein the predetermined opening position is less than the maximum opening position.
  10. The throttle assembly of claim 9, wherein the stop is switchable between at least two settings such that at one setting the maximum opening position of the throttle is restricted to the predetermined opening position and in another setting the maximum opening position of the throttle is unrestricted.
  11. The throttle assembly of claim 10, wherein the stop is switchable based on any or any combination of: a switch; and an accelerator pedal position.
  12. The throttle assembly of any of claims 9 to 11 wherein the stop is an electronic stop or a physical stop, and optionally the physical stop is any or any combination of: a moveable cam; a motorised cam.
  13. A system comprising an internal combustion engine configured to operate at a high compression ratio, a throttle in communication with the internal combustion engine and a controller operable to control the throttle in order to ensure that the engine is operable to compress an ingested fuel air mixture up to a predetermined compression threshold, at which, if the ingested fuel air mixture was permitted to exceed the threshold, damage to the engine would occur by knocking or pinking, whereby the controller is operable to: receive a throttle signal, the throttle signal operable to open the throttle to a first position; determine whether opening the throttle to the first position will cause the ingested fuel air mixture to exceed the predetermined compression pressure threshold by comparing a performance demand of the first throttle position with predetermined map data that indicates safe/unsafe running conditions of the engine; and in response to a determination that opening the throttle to the first position will cause damage to the internal combustion engine, modify the throttle signal to open the throttle to a second position, the second position of the throttle having been determined to open the throttle to a position that will not cause damage to the internal combustion engine by knocking or pinking.
  14. The system of claim 13 wherein the high compression ratio of the internal combustion engine comprises a geometric compression ratio.
  15. The system of claim 13 or 14 wherein the step of modifying the throttle signal is performed over a time period, optionally wherein the time period is determined by determining the time required for the modified throttle signal to cause performance of the internal combustion engine to reach the performance demand indicated by the throttle signal.

Description

Field The present invention relates to internal combustion engines. More particularly, the present invention relates to an arrangement whereby internal combustion engines can be operated more efficiently at higher compression pressures. Background A vast majority of automobile vehicles are powered by internal combustion engines, such as petrol engines. An internal combustion engine in an automobile will include at least one cylinder and at least one piston working to create reciprocating motion, and a crankshaft. Other components of the engine convert the reciprocating motion of the piston in the cylinder to rotary motion of the crankshaft. All petrol engines compress air and fuel, then ignite it so that it burns. In a four stroke engine, for example as illustrated in Figure 1, there is provided an engine with one or more paired piston and cylinder where the piston is operable to move in and out of the cylinder where there are four steps in the combustion cycle: (1) the intake stroke 110, where the piston moves out of the cylinder and causes a pressure drop in the cylinder thus causing air and fuel 114 to be drawn into the cylinder via an intake 112; (2) the compression stroke 120, where the piston moves into the cylinder and compresses the air and fuel 122 in the cylinder; (3) the power stroke 130, where the compressed fuel and air is ignited 134 by the spark plug 132 and the piston moves out of the cylinder; and (4) the exhaust stroke 140, where the piston moves into the cylinder and causes the exhaust gases 142 to be expelled from the cylinder. As the piston inside the petrol engine moves out of the cylinder during the power stroke 130, the pressure inside the cylinder initially rises due to the fuel and air mixture igniting and creating exhaust gases, then the pressure stabilises and then falls (as the piston moves out of the cylinder and increases the space for the igniting fuel and air mixture to expand into within the cylinder) while the piston movement resulting from the ignition turns the crankshaft and causes the output of power from the engine to the vehicle. The compression ratio, specifically, the geometric compression ratio, is the ratio between the largest volume of the cylinder (with the piston having moved out of the cylinder to its fullest extent in normal operation) and the smallest volume of the cylinder (with the piston having moved into the cylinder to its fullest extent in normal operation), or more technically total swept volume of the cylinder with the piston at bottom dead centre (BDC) divided by the total compressed volume with the piston at the top dead centre (TDC). The pressure that the fuel and air mixture reaches, specifically the upper cylinder compression pressure when the spark from the spark plug ignites it during the power stroke, is a function of the amount of air trapped at the start of the compression stroke, the compression ratio and the point of ignition in degrees before top dead centre (TDC). So, for example, at the extremes this means more air trapped at a higher compression ratio results in the highest pressure whereas very little air trapped at a lower compression ratio results in the lowest pressure and conversely, more air trapped at a lower compression ratio might equal or be similar to less air trapped at a higher compression ratio. It is known that fuel burns more efficiently, creates more power and creates less CO2 and fewer emissions as the upper cylinder compression pressure of the fuel and air mixture increases. The upper cylinder compression pressure is a function of the amount of air trapped (often described as the volumetric efficiency) and the geometric compression ratio. However, if the upper cylinder compression pressure of the fuel and air mixture reaches too high a pressure, the flame front burning through the mixture when ignited by the spark plug can cause portions of the fuel and air mixture to explode instantaneously instead of burning in a controlled fashion. These instantaneous explosions are termed "detonation", "knocking" or "pinking". Other factors can cause the fuel and air mixture to ignite prematurely but which are not "knocking" or "pinking". For example, as when pressure increases in the fuel and air mixture temperature also increases, if the pressure becomes too high then the temperature of the fuel and air mixture can also cause the fuel and air mixture to ignite without the spark from the spark plug, termed "pre-ignition". Another example occurs when glowing carbon deposits remain present in the cylinder, these can ignite the fuel and air mixture. A further relevant example is the use of bad fuel or a type of fuel for which the engine is not designed, which can also cause pre-ignition. Thus, engine design among vehicle manufacturers requires the choice of a balanced compression ratio which is (a) a high enough compression ratio to benefit from the fuel efficiency, increased power and fewer emission of a high compression ratio a