DESC:TECHNICAL FIELD
[001] The embodiments herein generally relate to internal combustion engine for automotive vehicles, and more particularly to system and method to deactivate at least one operating cylinder for improving efficiency of the internal combustion engine.
BACKGROUND
[002] There are many vehicles today that come with V-6 or V-8 engines promising tremendous amount of power and torque but providing a very low efficiency at lower power and torque requirements. Cylinder deactivation has been a popular culture between many automotive giants since 1981 by its first introduction from Cadillac providing a V-8 engine with V-6 and V-4 usage. Alfa Romeo came with a similar concept and launched 1000 trial vehicles as taxi in 1983. Almost 25% reduction in fuel usage was recorded but no further developments were made. In 1993, Mitsubishi developed a cylinder deactivation concept that allowed the use of only two cylinders out of four, and simultaneously combined the variable valve timing technology and variable displacement, to reduce the pumping losses in the deactivated cylinders. The fuel consumption was reduced by 10-20% but the main gain was through variable timing, and not through variable displacement, so the idea was dropped in 1996 as the cost of the engine was too high.
[003] Currently, there are two types of cylinder deactivation methods used. Both of them aim towards cutting off the fuel supply to selected cylinders, in some way or the other and shut off the valves by isolating their valve train. But there are losses such as vibrations from moving pistons, friction from dead moving parts, lower lubrication due to unavailability of fuel and higher rotational inertia for a low powered engine which impacts the vehicle acceleration, engine braking and other critical parameters.
[004] It is known that by deactivating a portion of engine cylinders when the engine is operating at light load, that overall fuel economy can be improved. Typically, cylinders are deactivated by deactivating intake and exhaust poppet valves. A known art discloses a cylinder deactivation system which is achieved by disabling exhaust poppet valves. The intake valves are not disabled, but are opened and closed generally symmetrically about a top center or bottom center position of the piston. This results in a cost savings because valve deactivators are provided for exhaust valves and not intake valves. However, such a system does not eliminate valve deactivators, which are known to be problematic. For example, there are typically issues associated with latching the valve deactivators and difficulties in ensuring that they are latched within one engine cycle, particularly at high engine speeds.
[005] Currently commercially available variable displacement engines effectively “shuts down” some of the cylinders during certain low-load operating conditions. When a cylinder is “shut down”, its piston still reciprocates, neither air nor fuel is delivered to the cylinder. Thus the piston does not deliver any power during its power stroke. Since the cylinders that are shut down do not deliver any power, the proportionate load on the remaining cylinders is increased, thereby allowing the remaining cylinders to operate at an improved thermodynamic efficiency. Although the remaining cylinders tend to operate at improved efficiency, they still do not operate at their optimal efficiency the vast majority of the time because they are still not operating consistently at “full throttle.” i.e., they have same drawbacks of partial throttle operations, (e.g., lower compression, higher pumping losses) even though the scale of their inefficiencies is reduced.
[006] In existing engines used by current vehicles, the number of cylinders capable of being “shut down” when in variable displacement modes may be limited. For example, in the GM Generation IV small block V8 engine half of the cylinders are capable of being shut down. Current engine design, however, requires that the remaining 4 cylinders remain operational. Likewise, the six cylinder Honda™ J-series engine is capable of shutting down 3 or 4 cylinders. Yet there exist a need to have an engine design without necessarily requiring expensive alterations to the engine's design.
[007] Therefore, there exists a need for a system and method to deactivate at least one operating cylinder for improving efficiency of the internal combustion engine. Further, there exists a need for a system and method which obviates the aforementioned drawbacks.
OBJECTS
[008] The principal object of the embodiments disclosed herein is to provide a system to deactivate at least one cylinder for improving the efficiency of the internal combustion engine.
[009] Another object of the embodiments disclosed herein is to provide a system for improving the efficiency of the internal combustion engine using variable inertia.
[0010] Yet another object of the embodiments disclosed herein is to provide a method to deactivate at least one cylinder for improving the efficiency of the internal combustion engine.
[0011] Still another object of the embodiments disclosed herein is to provide a system to reduce friction and unwanted inertia during operation of the internal combustion engine with at least one deactivated cylinder.
[0012] Yet another object of the embodiments disclosed herein is to provide a system which is easy to manufacture and does not have complex valve train.
[0013] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[0014] The embodiments of the invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0015] FIG. 1 depicts side view of an engine having a first group of operating cylinders and a second group of operating cylinders in disengaged condition, according to an embodiment as disclosed herein;
[0016] FIG. 2 depicts side view of the engine having the first group of operating cylinders and the second group of operating cylinders in engaged condition, according to an embodiment as disclosed herein;
[0017] FIG. 3 depicts a flowchart of disengagement of second group of operating cylinders from the first group of operating cylinders in the engine, according to an embodiment as disclosed herein; and
[0018] FIG. 4 depicts a flowchart of engagement of second group of operating cylinders with the first group of operating cylinders in the engine, according to an embodiment as disclosed herein.

DETAILED DESCRIPTION
[0019] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed 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.
[0020] The embodiments herein achieve a system to deactivate at least one cylinder for improving the efficiency of the internal combustion engine. Further, the embodiments herein achieve a method to deactivate at least one cylinder for improving the efficiency of the internal combustion engine. Referring now to the drawings and more particularly to FIGS. 1 through FIG. 4, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0021] For the purpose of this description and ease of understanding, the internal combustion engine is considered to an engine at having least six operating cylinders. However, it is also within the scope of the invention to use any internal combustion with any number of cylinders such as V8, V10, and V12 etc. without otherwise deterring the intended function of aiding combustion of fuel as can be deduced from the description and corresponding drawings.
[0022] FIG. 1 depicts side view of an engine having a first group of operating cylinders and a second group of operating cylinders in disengaged condition, according to an embodiment as disclosed herein. In an embodiment, the system 100 includes crankshaft (not shown), a first group of operating cylinders 104, a second group of operating cylinders 106, at least one coupling 108, a control unit (not shown) embedded in an engine management system 102, a brake distribution system(not shown), at least one sensor 110, at least one detector means 112, and a flywheel 114.
[0023] The system 100 is operated between a high power required state and a low power required state. Further the system 100 includes the first group of operating cylinders 104 and the second group of operating cylinders 106. The first group of operating cylinders 104may include four cylinders and the second group of operating cylinders 106 may include two cylinders. However, it is also within the scope of the invention to use any internal combustion with any number of first group of operating cylinders and any number of second group of operating cylinders without otherwise deterring the intended function of aiding combustion of fuel as can be deduced from the description and corresponding drawings. The first group of operating cylinders 104 is connected to a first valve train (here after V4) and the second group of operating cylinders 106 is connected to a second valve train (here after V2). The first group of operating cylinders (V4) and the second group of operating cylinders (V2) operate together to form a V6 engine. When the engine requires high power the engine management system 102 operates said engine in high power requirement state by operating both of the first group of operating cylinders 104 and the second group of operating cylinders 106 in a firing mode. Similarly, when the engine requires low power the engine management system 102 operates the engine in low power requirement state by operating the first group of operating cylinders 104 in the firing mode.
[0024] FIG. 2 depicts side view of the engine having the first group of operating cylinders and the second group of operating cylinders in engaged condition, according to an embodiment as disclosed herein. The crankshaft (not shown) is divided into two parts by the coupling 108 as shown in FIG. 1.In an embodiment, the coupling 108 is a hydraulic coupling. However, it is also within the scope of the invention to provide any type of coupling without otherwise deterring the intended function of the coupling as can be deduced from the description and corresponding drawings. The coupling 108 configured to selectively connect and disconnect said first group of operating cylinders 104 with said second operating cylinders 106.
[0025] The system 100 further includes the control unit embedded in the engine management system 102 (here after EMS). Furthermore, the system includes the at least one sensor 110 adapted to be in communication with the engine management system 102 to measure vehicle load from a brake distribution system of said vehicle. Also the system 100 includes the at least one detector means 112 adapted to be in communication with said engine management system 102 to detect throttle position based on a driver’s input.
[0026] The engine management system 102is configured to receive at least one first signal indicating the throttle position in the engine according to a driver’s requirement. Further, the engine management system 102is configured to receive at least one second signal indicating vehicle load from the brake distribution system(not shown). The at least one first signal indicating a throttle position and the at least one second signal indicating vehicle load are continuously monitored by the EMS 102. The control unit (not shown) provided in the EMS senses the requirement of power for operating the engine according to driver’s driving condition. If the control unit in the EMS 102 senses the requirement of less power (low power) which can be catered by the first group of operating cylinders 104, it cuts-off the fuel supply to the second group of operating cylinders 106 (two cylinders V2). While the fuel supply is cut-off, the control unit does not disengage the coupling108 thus providing an advantage of reviving or resuming the two cylinders, in case of sudden requirement. Further, if the power requirement remains low for a predetermined time, the coupling 108is disengaged by the EMS 102, thus the system 100 operates as a V-4 engine, in terms of both performance and efficiency. Similarly, if the EMS 102 detects high power requirement, the EMS 102 resumes fuel supply for the two deactivated cylinders. Thus it operates all the six cylinders to generate power in the engine.
[0027] The engine management system 102 is configured to operate the engine in one of the high-power requirement state and the low-power requirement state. The high-power requirement state involves at least one operating cylinder operating in addition to operating cylinders at said low-power requirement state. The engine management system 102 is configured to operate said IC engine in one of a high-power requirement state and a low-power requirement state by referring to measured throttle position and measured vehicle load.
[0028] The engine management system 102 is further adapted to determine threshold inertia to switch said IC engine between the high power requirement state and the low power requirement state. The crankshaft (not shown) includes two different types of masses, one being the coupling 108 and the other being the flywheel 114. The coupling 108 includes a first predetermined inertia and the flywheel 114 includes a second predetermined inertia. The first predetermined inertia of the coupling 108 and the second predetermined inertia on the flywheel 114 work together when operated as the V6 engine. The first predetermined inertia of the coupling 108 and the second predetermined inertia on the flywheel 114 operate together to form a predetermined mass which is sufficient to cater any power fluctuations. The threshold inertia considered herein is a sum of the first predetermined inertia of the coupling 108 and the second predetermined inertia of the flywheel 114. In an embodiment, the threshold inertia of the flywheel 114 is decided to balance the four cylinders and the rest of inertia requirement is maintained through coupling 108.
[0029] FIG. 3 depicts a flowchart of disengagement of second group of operating cylinders from the first group of operating cylinders in the engine, according to an embodiment as disclosed herein. A method 200 for deactivating at least one operating cylinder of an internal combustion engine (IC engine) in a vehicle is disclosed. At step 202, the method includes operating said IC engine in a high-power requirement state, wherein said high-power requirement state includes firing a first group of operating cylinders 104 and a second group of operating cylinders 106, said first group of operating cylinders 104 and said second group of operating cylinders 106 are connected by a coupling 108. At step 204, the method includes determining vehicle load by at least one sensor 110 adapted to be in communication with said engine management system 102from a brake distribution system of said vehicle. At step 206, the method includes measuring throttle position by at least one detector means 112 adapted to be in communication with said engine management system102 based on a driver’s input. At step 208, the method includes receiving information by said engine management system 102 from said sensor 110 and said detector means 112. At step 210, the method includes determining by said engine management system 102 a low power requirement state for a first predetermined time period. At step 212, the method includes cutting off fuel supply to said second group of operating cylinders 106 by said engine management system 102. At step 214, the method includes analyzing power requirement by said engine management system 102 for a second pre-defined time period. At step 216, the method includes detecting a no power required state by said engine management system 102. At step 218, the method includes deactivating said second operating cylinders 106 by said engine management system 102 by disengaging said coupling 108.
[0030] The method for deactivating at least one operating cylinder is explained below. The engine management system 102is configured to receive at least one first signal indicating a throttle position in the engine according to a driver’s requirement. Further, the engine management system 102 is configured to receive at least one second signal indicating vehicle load from the brake distribution system (not shown).When the control unit in the EMS 102senses low power requirement state for operating the engine according to driver’s driving condition, it cuts-off the fuel supply to the V2 (two cylinders). The EMS 102analyzes power requirement for a first pre-defined time period. If the EMS 102detects no high power requirement, the EMS 102 sends a disengaging signal to the coupling 108. Further, if the EMS 102 detects high power requirement, the EMS 102 resumes fuel supply for the two deactivated cylinders. Thus it operates four cylinders when it senses low power requirement state and operates all the six cylinders to generate power when it senses high power requirement state.
[0031] FIG. 4 depicts a flowchart of engagement of second group of operating cylinders with the first group of operating cylinders in the engine, according to an embodiment as disclosed herein. A method 300 for activating at least one operating cylinder of an internal combustion engine (IC engine) in a vehicle is disclosed. At step 302, the method includes operating said IC engine in a low-power requirement state, wherein said low-power requirement state includes firing of a first group of operating cylinders 104. At step 304, the method includes determining vehicle load by at least one sensor 110 adapted to be in communication with said engine management system 102from a brake distribution system of said vehicle. At step 306, the method includes measuring throttle position by at least one detector means 112 adapted to be in communication with said engine management system102 based on a driver’s input. At step 308, the method includes receiving information by said engine management system102 from said sensor 110 and said detector means 112. At step 310, the method includes determining by said engine management system 102 a high-power requirement state for a first predetermined time period. At step 312, the method includes activating a coupling 108 disposed in said vehicle to connect said first group of operating cylinders 104 with a second group of operating cylinders 106by said engine management system 102. At step 314, the method includes holding firing signal for a second pre-defined time period by said engine management system 102. At step 316, the method includes activating said second operating cylinders 106 by resuming fuel supply to said second operating cylinders 106 by said engine management system 102. At step 318, the method includes operating said IC engine in a high-power requirement state, wherein said high-power requirement state includes firing said first group of operating cylinders 104 and said second group of operating cylinders 106.
[0032] The method for activating at least one operating cylinder is explained below. The engine management system 102receives at least one first signal indicating a throttle position in the engine according to a driver’s requirement. Further, the engine management system 102receives at least one second signal indicating vehicle load from the brake distribution system. The EMS 102detects high power requirement for a first pre-defined time. The EMS 102 sends an engaging signal to the coupling 108. Further, the EMS 102 maintains a firing signal on hold for a second pre-defined time period. The EMS 102 sends a resume signal to a fuel supply system to supply fuel and operates all the six cylinders to generate power when it senses high power requirement state.
[0033] In an embodiment, the technical advantages provided by the embodiments disclosed herein include reduced friction and unwanted inertia during operation as a V-4 with two deactivated cylinders, optimization of flywheel inertia catering to V-4 and V-6 requirements, improvement of fuel efficiency over current deactivation process technologies, and no complex geometry for valve train.
[0034] The foregoing description of the specific embodiments will 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.
,CLAIMS:We claim,
1. A system 100 for deactivating at least one operating cylinder of an internal combustion engine (IC engine) in a vehicle, said vehicle having an engine management system 102, comprising:
a first group of operating cylinders104 and a second group of operating cylinders 106;
a coupling 108 configured to selectively connect and disconnect said first group of operating cylinders 104 with said second operating cylinders 106;
a control unit embedded in said engine management system 102;
at least one sensor 110 adapted to be in communication with said engine management system 102 to measure vehicle load from a brake distribution system of said vehicle; and
at least one detector means 112 or pedal adapted to be in communication with said engine management system 102 to detect throttle position based on a driver’s input;
wherein,
said engine management system 102 is configured to engage and disengage said coupling 108 to connect said first group of operating cylinders 104 with said second group of operating cylinders 106 and to disconnect said first group of operating cylinders 104 with said second group of operating cylinders 106;
said engine management system 102 is configured to operate said engine in one of a high-power requirement state and a low-power requirement state; and
said engine management system 102 is adapted to determine threshold inertia to switch said IC engine between said high power requirement state and said low power requirement state.
2. The system 100 for deactivating at least one operating cylinder of an IC engine as claimed in claim 1, wherein said high-power requirement state involves at least one operating cylinder operating in addition to operating cylinders at said low-power requirement state.
3. The system 100 for deactivating at least one operating cylinder of an IC engine as claimed in claim 1, wherein said engine management system 102 is configured to operate said IC engine in one of a high-power requirement state and a low-power requirement state by referring to measured throttle position and measured vehicle load.
4. The system 100 for deactivating at least one operating cylinder of an IC engine as claimed in claim 1, wherein said first group of operating cylinders 104 and said second group of operating cylinders 106 includes a first valve train V1 and a second valve trainV2 respectively.
5. The system 100 for deactivating at least one operating cylinder of an IC as claimed in claim 3, wherein said engine management system 102 operates said engine in high power requirement state by operating both of said first group of operating cylinders 104 and said second group of operating cylinders 106 in a firing mode.
6. The system 100 for deactivating at least one operating cylinder of an IC as claimed in claim 5, wherein said engine management system 102 operates said engine in low power requirement state by operating said first group of operating cylinders 104 in said firing mode.
7. A method 200 for deactivating at least one operating cylinder of an internal combustion engine (IC engine) in a vehicle, said vehicle having an engine management system 102, comprising:
operating said IC engine in a high-power requirement state, wherein said high-power requirement state includes firing a first group of operating cylinders 104 and a second group of operating cylinders 106, said first group of operating cylinders 104 and said second group of operating cylinders 106 are connected by a coupling 108;
determining vehicle load by at least one sensor 110 adapted to be in communication with said engine management system 102from a brake distribution system of said vehicle;
measuring throttle position by at least one detector means 112 adapted to be in communication with said engine management system102 based on a driver’s input;
receiving information by said engine management system 102 from said sensor 110 and said detector means 112;
determining by said engine management system 102 a low power requirement state for a first predetermined time period;
cutting off fuel supply to said second group of operating cylinders 106by said engine management system 102;
analyzing power requirement by said engine management system 102 for a second pre-defined time period;
detecting a no power required state by said engine management system 102; and
deactivating said second operating cylinders 106 by said engine management system102 by disengaging said coupling 108.
8. A method 300 for activating at least one operating cylinder of an internal combustion engine (IC engine) in a vehicle, said vehicle having an engine management system, comprising:
operating said IC engine in a low-power requirement state, wherein said low-power requirement state includes firing of a first group of operating cylinders 104;
determining vehicle load by at least one sensor 110 adapted to be in communication with said engine management system 102from a brake distribution system of said vehicle;
measuring throttle position by at least one detector means 112 adapted to be in communication with said engine management system102 based on a driver’s input;
receiving information by said engine management system102 from said sensor 110 and said detector means 112;
determining by said engine management system 102 a high-power requirement state for a first predetermined time period;
activating a coupling 108 disposed in said vehicle to connect said first group of operating cylinders 104 with a second group of operating cylinders 106by said engine management system 102;
holding firing signal for a second pre-defined time period by said engine management system 102;
activating said second operating cylinders 106 by resuming fuel supply to said second operating cylinders 106 by said engine management system 102; and

operating said IC engine in a high-power requirement state, wherein said high-power requirement state includes firing said first group of operating cylinders 104 and said second group of operating cylinders 106.