Patent Application
20130152907
The present disclosure relates to an internal combustion engine induction system and, more particularly, to an internal combustion engine induction system utilizing electronic pressure charging.
A four stroke engine of the kind typically used in automotive engines goes through two crankshaft rotations for each firing event in a given engine combustion chamber. During the first part of the cycle (“intake stroke”), intake valves are opened and a piston descends from the top of the combustion chamber drawing fresh air and fuel into a combustion chamber. Once the piston reaches the bottom of its stroke, the intake valves are closed and the piston begins to rise (“compression stroke”). The compressed air/fuel mixture is ignited in the combustion chamber as the piston reaches the top of the combustion chamber causing the piston to once again descend (“power stroke”). Exhaust valves are opened once the piston reaches the bottom of its stroke and starts to rise once again, thus, forcing the combusted air/fuel mixture out of the combustion chamber through the exhaust valves (“exhaust stroke”). The exhaust valves are closed once the piston reaches the top of the combustion chamber and the cycle repeats itself. In some engines, the exhaust valves may remain open for an initial portion of the intake stroke, thus overlapping in their opening with the intake valves.
The induction system of an internal combustion engine is typically designed to provide as much air into the combustion chamber as possible. During the intake stroke, air rapidly moves from an engine intake manifold, into an intake runner, through the open intake valve, and into the combustion chamber. When the compression stroke begins, the intake valve is shut and the column of air in the intake runner that was moving into the combustion chamber rapidly comes to a halt. This creates a positive pressure at the intake valve that then reverberates back through the intake runner and into the intake manifold. Once in the intake manifold, the positive pressure wave reflects back into the intake runner until it hits the intake valve. The positive pressure wave will reflect back and forth in the intake tract slowly diminishing in amplitude over time. Timing the opening of the intake valve with the arrival of the positive pressure wave at the intake valve can provide additional air/fuel mixture into the combustion chamber, resulting in increased engine efficiency and power.
Conversely, arrival of a negative pressure wave during the time at which the intake valve is open will cause less air/fuel mixture to enter the combustion chamber. The arrival of the positive pressure wave at the intake valve at the correct time is highly dependent on the rotations per minute (“RPM”) of the engine and the geometry of the induction system. Because the timing is dependent, among other things, on engine RPM, the pressure wave generally will only arrive at the intake valve at the proper time for a small portion of the engine's operating range. Mechanically variable geometry induction systems attempt to solve this problem by altering the geometry of the induction system to increase the percentage of the engine's RPM range at which the intake pressure wave arrives at the intake valve while the intake valve is open. However, these systems generally only offer two, or sometimes three different intake tract geometries, still leaving large portions of the engine RPM range in which the positive pressure wave is not advantageously timed. Some infinitely variable geometry intake tracts have been created. However, like intake tracts with only two or three geometries, infinitely variable systems are complex, expensive, bulky, and still cannot optimize the timing of the intake pressure wave with the intake valve opening for all operating conditions. Moreover, the effect of variable geometry systems on the pressure wave is still limited by the physical geometry of the intake tract. Therefore, there is room for improvement in the art.
In one form, the present disclosure provides a method of manipulating pressure in an internal combustion engine including a pressure sensor, a signal conditioner, and a wave generator. The method includes sensing a pressure wave using the pressure sensor, communicating the sensed pressure wave to the signal conditioner, and generating an electronic wave form using the signal conditioner in response to the sensed pressure wave. The method also includes transmitting the electronic wave form to the wave generator, and generating a pressure wave using the wave generator and based upon the electronic pressure wave.
In another form, the present disclosure provides an electronic pressure charging system for pressurizing a confined volume. The system includes a first pressure sensor, a signal conditioner, and a first wave generator. The first pressure sensor is configured to detect a first pressure wave, the signal conditioner is configured to generate an electronic waveform in response to the sensed pressure wave, and the first wave generator is configured to generate a pressure wave based upon the electronic waveform generated by the signal conditioner.
Thus, an induction system having electronic pressure charging is provided. The induction system provides for optimizing an intake pressure wave to improve engine efficiency and performance. The induction system is capable of increasing a positive portion of the pressure wave, decreasing a negative portion of the pressure wave, or altering the pressure wave in any desired manner.
Further areas of applicability of the present disclosure will become apparent from the detailed description and claims provided hereinafter. It should be understood that the detailed description, including disclosed embodiments and drawings, are merely exemplary in nature intended for purposes of illustration only and are not intended to limit the scope of the invention, its application or use. Thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention.
Disclosed herein are exemplary embodiments of an induction system which optimizes the intake pressure wave under engine operating and environmental conditions and does not rely on mechanical changes to the geometry of the induction system. The embodiments disclose an induction system that can increase the size of the positive pressure wave, decrease the size of a corresponding negative pressure wave, or alter the intake pressure waves in desirable manners.
The electronic pressure charging system further includes a pressure sensor 61 mounted in the intake tract 10. In one embodiment, the pressure sensor 61 may be a manifold absolute pressure sensor (“MAP”) of the type typically found on many automotive engines. In one embodiment, the pressure sensor 61 may be any kind of air or other fluid pressure sensor. The pressure sensor 61 is preferably located somewhere in the intake tract 10. In one embodiment, the pressure sensor 61 may be located in an intake manifold or plenum portion of the intake tract 10 that provides an air/fuel mixture to all of the engine's 1 combustion chambers 3. In this embodiment, a single pressure sensor 61 may detect the pressure waves for each of the combustion chambers 3. Alternatively, multiple pressure sensors may be used in the intake manifold or plenum. In one embodiment, the pressure sensor 61 may be located in an individual intake runner that supplies air to a single combustion chamber 3. In this embodiment the pressure sensor 61 may detect the pressure wave for each individual combustion chamber 3. In one embodiment where the pressure sensor 61 is in an individual intake runner, at least one pressure sensor 61 may be employed in each intake runner. It should be appreciated that any number of pressure sensors 61 may be employed and that the pressure sensors 61 may be located anywhere in the intake tract 10. In one embodiment, the location of the pressure sensor 61 is dictated by the geometry of the intake tract 10.
The electronic pressure charging system further includes a signal conditioner 52 coupled to the pressure sensor 61. Calibration adjustments 50 are also coupled to the signal conditioner 52. Calibration adjustments 50 may include sensor inputs such as throttle position, engine load, engine RPM, valve timing, camshaft position, air temperature, and other environmental or vehicle conditions. The signal conditioner 52 analyzes data from the pressure sensor 61 and calibration adjustments 50 and provides a waveform signal to an amplifier 56. The amplifier 56 receives power from a power source 55. The power source 55 may be any type of power source including power sources typically found in a vehicle such as a battery or an alternator. The amplifier 56 amplifies the waveform from the signal conditioner 52 and drives a wave generator 62.
The wave generator 62 may any type of device that is capable of transforming electrical current into a fluid pressure wave such as an electromechanical transducer. In one embodiment, the wave generator 62 may be a piezoelectric crystal. In one embodiment, the wave generator 62 may be a device with a diaphragm similar to an audio speaker. The wave generator 62 is preferably mounted in the intake tract 10 of the engine 1. In one embodiment, there is a single wave generator 62 for each pressure sensor 61. In one embodiment, there may be more than one wave generator 62 for each pressure sensor 61. In one embodiment, there may be more than one pressure sensor 61 for each wave generator 62. In one embodiment, the wave generator 62 may be located in the intake manifold or plenum. In this embodiment, a single pressure sensor 61 and a single wave generator 62 are typically used. The single wave generator 62 generates a pressure wave as needed for each combustion chamber 3. However, more than one pressure sensor 61 and/or wave generator 62 may be utilized as desired. In one embodiment, the wave generator 62 may be located in an individual intake runner that supplies air to a single combustion chamber 3. In this embodiment, there is typically one wave generator 62 and one corresponding pressure sensor 61 in each intake runner for each combustion chamber 3. The corresponding pressure sensor 61 and wave generator 62 produce a pressure wave for their corresponding combustion chamber 3. It should be appreciated that any number of wave generators 62 may be employed and that the wave generators 62 may be located anywhere in the intake tract 10. In one embodiment the location of the wave generator 62 is dictated by the geometry of the intake tract 10.
In operation, the pressure sensor 61 measures the pressure waves in the intake tract 10 and transmits this information to the signal conditioner 52. Using information from the pressure sensor 61, calibration adjustment 50, and preprogrammed information about the geometry of the intake tract, the signal conditioner 52 generates an electronic waveform that is transmitted to the amplifier 56. The amplifier 56 transmits an amplified electronic waveform to the wave generator 62, which turns the amplified electronic waveform into a physical pressure wave. The pressure wave generated by the wave generator 62 is physically superimposed upon the pressure wave detected by the wave detector 61. In one embodiment, the signal conditioner 52 may cause the wave generator 62 to generate a waveform that is in phase with the waveform detected by the pressure sensor 61, thereby, amplifying the pressure wave within the inlet tract 10. For example, the waveform may be generated such that the resultant in-phase amplified positive pressure wave would reach the intake valve 11 at a time when the intake valve 11 is open during the intake stroke portion of the combustion cycle, thereby, causing pressurized air/fuel mixture to enter the combustion chamber 3 and improving engine efficiency and performance. Simultaneously, the resultant in-phase amplified negative portion of the pressure wave may be timed to reach the intake valve 11 when the intake valve 11 is closed, such as during the power stroke, compression stroke, or exhaust stroke. Thus, the lower air/fuel pressure associated with the negative portion of the in-phase pressure wave is avoided in the combustion chamber 3 during the intake stroke portion of the combustion cycle, thereby, avoiding performance or efficiency robbing reduced combustion chamber 3 pressure during the intake stroke.
It should be noted that the generated waveform may be used to create any type of pressure pattern desired in the intake tract 10 at any point during the combustion cycle. In one embodiment, the wave generator 62 may be utilized to reduce or completely cancel out pressure waves within the intake tract 10. To cancel out a pressure wave, the signal conditioner 52 would generate a waveform opposite to that detected by the pressure sensor 61. Thus, the pressure wave detected by the pressure sensor 61 would be completely eliminated or, at the very least, reduced when the opposite waveform generated by the wave generator 62 is superimposed onto the originally detected pressure wave. In one embodiment, the opposite, or cancelling, waveform may be generated to improve engine 1 efficiency. Generating a cancelling waveform and timing the neutralized intake pressure wave with the opening of the intake valve 11 will reduce the pressure in the combustion chamber 3 compared to a positive pressure wave at the same location and time. The reduction in pressure causes less air/fuel mixture to enter the combustion chamber 3, resulting in less fuel being burnt and increased efficiency. In one embodiment, instead of a neutral pressure wave, the wave generator 62 may create an in-phase negative pressure wave such that the resultant superimposed negative pressure wave arrives at the intake valve 11 while the intake valve 11 is open. Thus, pressure in the combustion chamber 3 will be even lower than with the neutralized intake pressure wave, resulting in further improved fuel efficiency. As such, the generated waveform may be utilized to reduce the effective compression ratio of the combustion chamber 3.
In some engines 1, the intake valve 11 and exhaust valve 21 may be open simultaneously for a short portion of time at the end of the exhaust stroke and beginning of the intake stroke. This achieves an effect known as exhaust scavenging in which the combusted air/fuel mixture exiting the combustion chamber 3 through the exhaust valve 21 and exhaust tract 20 literally sucks in new air/fuel mixture through the intake valve 11 and intake tract 10. In such engines 1, it may be desirable to amplify a positive pressure wave during this period of intake valve 11 and exhaust valve 21 overlap by utilizing the electronic pressure charging system to generate an in-phase positive pressure wave resulting in a superimposed large positive pressure wave and, thereby, more effectively expelling the combusted air/fuel mixture from the combustion chamber 3 and drawing into the combustion chamber 3 fresh air/fuel mixture.
In one embodiment, by timing a positive pressure wave with the opening of the intake valve 11, the electronic pressure charging system achieves an effect similar to turbo charging or supercharging, albeit at a lesser scale. At the same time, the electronic pressure charging system is more energy efficient, less complex, and less costly than supercharging or turbo charging. In one embodiment, the electronic pressure charging system may be used in combination with supercharging and/or turbo charging or any other means of forced induction.
In one embodiment, the signal conditioner 52 may employ adaptive learning control based upon inputs from the calibration adjustment 50 and/or pressure sensor 61. The adaptive control may enable the signal conditioner 52 to continuously adjust the generated waveform to optimize vehicle performance, efficiency, or any other desired operational parameter. The signal conditioner 52 may optimize vehicle operation without the mechanical changes to the intake tract 10 required by prior art systems. In one embodiment, the signal conditioner 52 may be employed to optimize vehicle operation in conjunction with mechanical changes to the intake tract 10 such as a variable geometry intake tract.
It should be understood that the embodiment depicted in
In one embodiment, the electronic pressure charging system may be utilized with any type of internal combustion engine including, but not limited to, a two stroke engine, four stroke engine, Atkinson cycle engine, or any other type of internal combustion engine. In one embodiment, the electronic pressure charging system may be utilized in any application in which it is desirable to adjust the pressure of a fluid in a confined area. For instance, the electronic pressure charging system may be utilized in any application featuring an intake tract and a confined volume (combustion chamber), whether or not actual combustion takes place.
Thus, an electronic pressure charging system for optimizing the amount of a fluid in a combustion chamber is provided. The electronic pressure charging system tunes the amount of air in a combustion chamber by altering the pressure waves generated during operation of an engine to achieve a desired level of engine performance and fuel efficiency. The electronic pressure charging system is capable of increasing a positive portion of the pressure wave, decreasing a negative portion of the pressure wave, or altering the pressure wave in any desired manner without requiring physical changes to the geometry of the intake tract.
