Description:FIELD
The present disclosure relates to engines of vehicles, more specifically, engines operating on Miller combustion cycle.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
With the evolution of stringent pollution norms to reduce carbon emissions, there arose a need to optimize the design of vehicle engines to make them more efficient and provide more fuel economy. An engine based on the Miller combustion cycle has been proved to have an optimized configuration when compared to the conventional Otto combustion cycle. Further, the Miller cycle operated engine has its valve timing configured in a way that pumping losses are minimized. However, the same valve timing reduces the ability of the engine to rapidly produce torque, thereby making engine response slower and overload on turbo charger.
Therefore, there is felt a need for a system that alleviates the aforementioned drawbacks of the Miller cycle operated engine.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a system that optimizes the configuration of the Miller cycle operated engine.
Another object of the present disclosure is to provide a system that enhances the ability of the Miller cycle operated engine to rapidly produce torque while improving the engine response.
Yet another object of the present disclosure is to provide a system that reduces overload on an engine turbo charger.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a system for actuating a variable valve timing (VVT) mechanism of a Miller engine. The system comprises a first sensing unit configured to sense a force with which an accelerator pedal is pressed, and further configured to generate a first sensed signal. An actuator is configured to actuate the VVT mechanism, in response to the first sensed signal, for achieving a required torque. The system further comprises a set of second sensing units configured to monitor at least one critical parameter of the vehicle. The set of second sensing units is configured to generate at least one sensed signal to actuate the VVT mechanism in the event that the first sensed signal fails to actuate the VVT mechanism.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A system, of the present disclosure, for actuating a variable valve timing mechanism of a Miller engine will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a block diagram depicting the system of the present disclosure; and
Figure 2A and Figure 2B illustrate graphical representations of the torque achieved by a basic Miller engine (without the provision of VVT mechanism) and a Miller engine equipped with dynamic VVT mechanism and the system for Gear 1 and Gear 2, respectively.
LIST OF REFERENCE NUMERALS
100 system
102 first sensing unit
104 second sensing unit
106 third sensing unit
107 control unit
108 converter
110 repository
112 processor
114 actuator
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including”, “includes” and “having” are open-ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
A system (100), of the present disclosure, for actuating a variable valve timing (VVT) mechanism of a Miller engine will now be described in detail with reference to Figure 1 through Figure 2B.
The Miller engine is configured to be fitted in a vehicle which is provided with an accelerator pedal. The Miller engine is configured to control the NOx emissions while reducing pumping losses at part load at an improved efficiency. The system (100), of the present disclosure, is configured to rapidly produce torque when desired by a user.
The system (100) comprises a first sensing unit (102) and an actuator (114). The first sensing unit (102) is configured to sense a force with which the accelerator pedal is pressed, and is further configured to generate a first sensed signal. The actuator (114) is configured to actuate the VVT mechanism, in response to the first sensed signal, for achieving a required torque. The system (100) further comprises a set of second sensing units (104) configured to monitor at least one critical parameter of the vehicle. The set of second sensing units (104) is configured to generate at least one sensed signal to actuate the VVT mechanism in the event that the first sensed signal fails to actuate the VVT mechanism.
Actuating the variable valve timing enables identification of the user’s requirements and altering the valve timings accordingly to allow the Miller engine to produce dynamic toque, thereby improving the vehicle performance.
In an embodiment, the system (100) includes a third sensing unit (106) configured to sense the rate of flow of air into the engine. The third sensing unit (106) is further configured to generate a third sensed signal.
The system (100) includes a control unit (107) including a converter (108), a repository (110) and a processor (112).
The converter (108) is configured to communicate with the first sensing unit (102) to receive the first sensed signal, and is further configured to communicate to the third sensing unit (106) to receive the third sensed signal. The converter (108) is configured to convert the first sensed signal and the third sensed signal into first sensed value and the third sensed value respectively.
The repository (110) is configured to store a first threshold value corresponding to the difference between rate of flow of air demanded by the engine and the available rate of flow of air into the engine.
The processor (112) is configured to communicate with the converter (108) to receive the first sensed value and the second sensed value. The processor (112) is further configured to communicate with the repository (110) to receive the first threshold value. The processor (112) is configured to process the difference between the first sensed value and the third sensed value, and is further configured to compare the difference with the first threshold value.
In an embodiment, the processor (112) is configured to generate a first compared signal if the difference is greater than the first threshold value, or a second compared signal if the difference is less than the first threshold value.
In another embodiment, the actuator (114) is configured to receive the first compared signal to actuate the VVT mechanism. In yet another embodiment, the actuator (114) is configured to receive the second compared signal to deactivate the VVT mechanism.
In an embodiment, each of the second sensing unit (104) includes a sensor and a converting unit. The sensor is configured to monitor a parameter of the set of critical parameters, and is further configured to generate a sensed value. The converting unit is configured to be coupled to the sensor. The converter (108) is configured to receive the sensed value, and is further configured to convert the sensed value to the second sensed signal.
In an embodiment, the critical parameters are selected from the group consisting of boost pressure, drive mode, gears, coolant temperature, air temperature, ambient pressure, engine speed, timer, air flow rate, engine knocking or a combination thereof.
In another embodiment, the repository (110) includes a set of second threshold values, wherein each value corresponds to each of the critical parameters.
In an embodiment, the processor (112) is configured to communicate with the second sensing units (104) to receive the second sensed signal. The processor (112) is configured to convert the second sensed signal to second sensed value. The processor (112) is configured to communicate with repository (110) to compare the second sensed value with the second threshold value.
In another embodiment, the processor (112) is configured to generate a third compared signal if the second sensed value is less than the second threshold value, or a fourth compared signal if the second sensed value is greater than the second threshold value.
In yet another embodiment, the actuator (114) is configured to communicate with the control unit (107) to receive the third compared signal to actuate the VVT mechanism. In still another embodiment, the actuator (114) is configured to receive the fourth compared signal to deactivate the VVT mechanism.
In accordance with a first exemplary embodiment of the present disclosure, it is necessary that the system (100) satisfies at least one of the following conditions to activate the VVT mechanism. The conditions include:
a) Force with which the accelerator pedal is pressed exceeds the threshold force of pressing the accelerator pedal;
b) Torque demanded exceeds the threshold torque;
c) Difference between desired boost pressure and actual boost pressure exceeds a threshold value;
d) Drive mode;
e) Value of coolant temperature is less than the threshold value of coolant temperature;
f) Value of air temperature is less than the threshold value of air temperature; and
g) Value of speed of the engine is less than the threshold value of speed of the engine.
In an embodiment, the dynamic VVT, of the first exemplary embodiment, is activated when the difference between the acceleration required by the user and the actual torque produce is relatively high.
In another embodiment, the dynamic VVT is activated when defined speed range varies between 1000RPM to 3000RPM.
In yet another embodiment, the dynamic VVT is activated when the drive is selected from the group consisting of Eco drive, Sports drive, and Comfort drive.
To deactivate the VVT mechanism of the first exemplary embodiment, at least one of the following conditions must be satisfied:
a) Force with which the accelerator pedal is pressed is less than the threshold force of pressing the accelerator pedal;
b) Torque demanded is less than the threshold torque;
c) Difference between desired boost pressure and actual boost pressure exceeds a threshold value;
d) Drive mode;
e) Value of coolant temperature is greater than the threshold value of coolant temperature;
f) Value of air temperature is greater than the threshold value of air temperature; and
g) Value of speed of the engine is greater than the threshold value of speed of the engine.
In an embodiment, the dynamic VVT, of the first exemplary embodiment, is deactivated when the difference between the torque demanded by the driver and the torque produced by the engine is less than a threshold value.
In another embodiment, the dynamic VVT is deactivated when boost pressure demanded by the driver and the actual boost pressure produced is less than a threshold value.
In yet another embodiment, the dynamic VVT is deactivated on release of the accelerator pedal.
In still another embodiment, the dynamic VVT is deactivated after a predetermined duration of activation of the VVT mechanism.
In yet another embodiment, further conditions of deactivation of the dynamic VVT are inhibiting conditions from the boost pressure control, operational limits of the engine temperature, major spark retardation by knock control, and charge temperature.
In accordance with a second exemplary embodiment of the present disclosure, it is necessary that the system (100) satisfies at least one of the following conditions to activate the VVT mechanism. The conditions include:
a) Difference between the rate of flow of air demanded and the available rate of flow of air exceeds the threshold value of difference between the flow of air demanded and the available flow of air;
b) Rate of flow of air demanded by the engine exceeds the threshold value of rate of flow of air required;
c) Boost pressure;
d) Drive mode;
e) Value of coolant temperature is less than the threshold value of coolant temperature;
f) Value of air temperature is less than the threshold value of air temperature; and
g) Value of speed of the engine is less than the threshold value of speed of the engine.
In an embodiment, the dynamic VVT is activated when the airflow rate required to generate torque demanded by the user is higher than a threshold, and the difference between driver demanded airflow rate and actual engine airflow rate is high.
In another embodiment, the dynamic VVT is activated when the pressure-based airflow rate is equal to its threshold value.
In yet another embodiment, the dynamic VVT is activated when the defined speed range varies between 1000 RPM to 3000 RPM.
In still another embodiment, the dynamic VVT is activated during Eco drive mode, Sports drive mode, and Comfort drive mode.
In another embodiment, the dynamic VVT is activated based on air and coolant temperatures.
In yet another embodiment, the dynamic VVT is activated based on the engine boost pressure.
To deactivate the VVT mechanism of the second exemplary embodiment, at least one of the following conditions must be satisfied:
a) Difference between the rate of flow of air demanded and the available rate of flow of air is less than the threshold value of difference between the rate of flow of air demanded and the available rate of flow of air;
b) Rate of flow of air demanded by the engine is less than the threshold value of rate of flow of air required;
c) Difference between desired boost pressure and actual boost pressure exceeds a threshold value;
d) Drive mode;
e) Value of coolant temperature is greater than the threshold value of coolant temperature;
f) Value of air temperature is greater than the threshold value of air temperature; and
g) Value of speed of the engine is greater than the threshold value of speed of the engine.
In an embodiment, the dynamic VVT is deactivated when the difference between airflow rate for torque demanded by the user and the actual airflow rate to the engine is lesser than a defined threshold.
In another embodiment, the dynamic VVT is deactivated when the airflow rate required to generate driver demanded torque is lesser than a threshold value.
In yet another embodiment, the dynamic VVT is deactivated after a predetermined duration of activation of the VVT mechanism.
In still another embodiment, other conditions that cause early deactivation of dynamic VVT are inhibiting conditions from the boost pressure control, operational limits of the engine temperature, major spark retardation by knock control, and charge temperature.
Figures 2A and 2B illustrate graphical representations of the torque achieved by a basic Miller engine (without the provision of VVT mechanism) and a Miller engine equipped with dynamic VVT mechanism and the system (100) for Gear 1 and Gear 2. From both the graphical representations, it is evident that for both the gears, the dynamic VVT mechanism helps in achieving higher amounts of torque for a given value of speed. It is inferred therefore, that the system (100) helps in improving the dynamic torque producing capability of the Miller engine for enhancing the vehicle performance, by identifying the user’s requirements and altering the valve timings to provide the desired performance. Further, the system (100) helps the engine to switch to the VVT mechanism for optimum fuel economy even when more performance is demanded by the user. The system (100) additionally helps in altering the VVT mechanism based on the fuel quality learnt from the engine knocking tendency, to deliver the best possible performance for that fuel quality.
Additionally, it has been observed that the transient torque generation performance of the engine operated on Miller combustion cycle has improved for all gears, with significant improvement of 15% to 20% from the first gear to the third gear.
Further it has been observed that the Miller engine provided with the dynamic VVT and the system (100) of the present disclosure, takes less response time to achieve a particular acceleration as compared to the basic Miller engine. More specifically, if the basic Miller engine takes ‘x’ seconds to achieve an acceleration of 60Kmph, the engine equipped with dynamic VVT takes ‘x-0.93’ seconds to achieve the same acceleration.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of system for actuating a variable valve timing mechanism of a Miller engine which:
• optimizes the configuration of the Miller cycle operated engine;
• enhances the ability of the Miller cycle operated engine to rapidly produce torque while improving the engine response;
• improves transient torque generation performance of the Miller operated engine from 15% to 20%; and
• reduces overload on an engine turbo charger.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Any discussion of materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. , C , Claims:WE CLAIM:
1. A system (100) for actuating a variable valve timing (VVT) mechanism of a Miller engine fitted in a vehicle, the vehicle having an accelerator pedal, said system (100) comprising:
• a first sensing unit (102) configured to sense a force with which the accelerator pedal is pressed, and further configured to generate a first sensed signal;
• an actuator (114) configured to actuate the VVT mechanism, in response to said first sensed signal, for achieving a required torque; and
• a set of second sensing units (104) configured to monitor at least one critical parameter of the vehicle, said set of second sensing units (104) configured to generate at least one sensed signal to actuate the VVT mechanism in the event that said first sensed signal fails to actuate the VVT mechanism.
2. The system (100) as claimed in claim 1, wherein said system (100) includes a third sensing unit (106) configured to sense the rate of flow of air into the engine, and further configured to generate a third sensed signal.
3. The system (100) as claimed in claim 2, wherein said system (100) includes a control unit (107) including:
o a converter (108) configured to communicate with said first sensing unit (102) to receive said first sensed signal, and further configured to communicate to said third sensing unit (106) to receive said third sensed signal, said converter (108) configured to convert said first sensed signal and said third sensed signal into first sensed value and said third sensed value respectively;
o a repository (110) configured to store a first threshold value corresponding to the difference between the rate of flow of air demanded by the engine and the available rate of flow of air into the engine; and
o a processor (112) configured to communicate with said converter (108) to receive said first sensed value and said second sensed value, said processor (112) further configured to communicate with said repository (110) to receive said first threshold value, said processor (112) configured to process the difference between said first sensed value and said third sensed value, and further configured to compare said difference with said first threshold value.
4. The system (100) as claimed in claim 3, wherein said processor (112) is configured to generate a first compared signal if said difference is greater than said first threshold value, or a second compared signal if said difference is lesser than said first threshold value.
5. The system (100) as claimed in claim 4, wherein said actuator (114) is configured to receive said first compared signal to actuate the VVT mechanism, or is configured to receive said second compared signal to deactivate the VVT mechanism.
6. The system (100) as claimed in claim 1, wherein each of said second sensing unit (104) includes:
o a sensor configured to monitor a parameter of said set of critical parameters, and further configured to generate a sensed value; and
o a converting unit coupled to said sensor, said converting unit configured to receive said sensed value, and further configured to convert said sensed value to said second sensed signal.
7. The system (100) as claimed in claim 6, wherein said critical parameters are selected from the group consisting of boost pressure, drive mode, gears, coolant temperature, air temperature, ambient pressure, engine speed, timer, air flow rate, engine knocking or a combination thereof.
8. The system (100) as claimed in claim 7, wherein said repository (110) includes a set of second threshold values, each value corresponding to each of said critical parameters.
9. The system (100) as claimed in claim 8, wherein said processor (112) is configured to communicate with said second sensing units (104) to receive said second sensed signal, said processor (112) configured to convert said second sensed signal to second sensed value, said processor (112) being configured to communicate with said repository (110) to compare said second sensed value with said second threshold value.
10. The system (100) as claimed in claim 9, wherein said processor (112) is configured to generate a third compared signal if said second sensed value is lesser than said second threshold value, or a fourth compared signal if said second sensed value is greater than said second threshold value.
11. The system (100) as claimed in claim 10, wherein said actuator (114) is configured to communicate with said control unit (107) to receive said third compared signal to actuate the VVT mechanism, or is configured to receive said fourth compared signal to deactivate the VVT mechanism.

Dated this 12th day of January, 2023

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
of R.K.DEWAN & CO.
Authorized Agent of Applicant

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT CHENNAI