DESC:FIELD OF THE INVENTION
[001] The present invention relates to a multi-dimensional intake throttle valve (ITV) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response and method of manufacturing thereof.
BACKGROUND
[002] In the conventional CNG BS-VI vehicle, engines operate with stoichiometric air-fuel mixture during operating conditions, whereas diesel engines operate with lean air-fuel mixture, due to excess air availability during operating conditions. Since in the diesel engines, torque/power output control via fuel injection quantity and as these engines always have excess amount of air, hence there is no need of precise air flow control system.
[003] Further during transient operation, precise air-fuel ratio control is very difficult, due to continuous change of ITV position, which leads to mismatch in air-fuel ratio, results in loss in fuel economy. Additionally, during transient conditions, faster ITV opening/closing leads to engine RPM fluctuation (known as engine hunting). Therefore, in addition to ITV position, rate of change of ITV position is also very crucial and important for precise air flow control and smoother engine operation during transient conditions.
BRIEF SUMMARY
[004] The present invention discloses a multi-dimensional intake throttle valve (itv) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response and method of manufacturing thereof.
[005] The present invention allowing a calibratable, variable, value of ITV opening and closing rate, on the basis of engine RPM and accelerator pedal demand by driver. Here the present invention allows desired opening/closing rate of ITV for different vehicle operating modes depending upon accelerator pedal demand by driver. The Table-1 herein below describes an ITV operation in different operating modes. The algorithms to enable this logic in EMS have been developed in-house.
[006] The below example exemplifies ITV opening rate with conventional and new methods:
[007] Example: 1
Vehicle specifications/Details:
• Vehicle Model ? Eicher Pro2059XP CNG BS6
• Vehicle Type ? Truck
• Application ? City Plus Highway
• Max vehicle speed ? 80 km/hr
• Max Gross Vehicle Base (GVW) ? 7.5 tons
Engine specifications/Details:
• Engine Name ? E483 NA CNG BS6
• Engine Swept Volume/Capacity (Lit) ? 3.3 Lit
• Max Torque ? 245 Nm @ 1600 RPM
• Rated Power ? 70 kW @ 3100 RPM
• Minimum engine speed (RPM) ? 800
• Maximum engine speed (RPM) ? 3500
ITV Logic in conventional EMS logic/mechanism: Single valve for entire engine/vehicle operating range
• ITV opening rate ? 100 %/sec,
• ITV closing rate ? -100 %/sec

[008] In one embodiment, the present invention discloses the ITV Logic with new EMS logic/mechanism: Two dimensional maps on the basis of engine RPM and pedal position for ITV opening and closing rate.
ITV Opening rate table (data in %/sec)
X-Axis: Engine Speed (RPM)
800 1600 2400 3100 3200 3500
Y-Axis: Pedal Position (%) 100 200 200 150 80 30 30
80 200 200 150 80 30 30
50 150 150 100 100 100 100
20 100 100 100 100 100 100
10 50 50 100 100 100 100
0 50 50 100 100 100 100

ITV Closing rate table (data in %/sec)
X-Axis: Engine Speed (RPM)
800 1600 2400 3100 3200 3500
Y-Axis: Pedal Position (%) 100 -100 -100 -100 -80 -30 -30
80 -100 -100 -100 -80 -30 -30
50 -100 -100 -100 -100 -100 -100
20 -100 -120 -120 -120 -120 -120
10 -100 -150 -150 -150 -150 -150
0 -150 -200 -200 -200 -200 -200

Note: In case of RPM/pedal position other than values mentioned in the table, EMS will do take inputs by interpolating the data.

Table.1: ITV Movement in Eicher Pro2059XP CNG BS6 vehicle with new EMS logic in different vehicle operating conditions
Sr. No. Operating Mode Pedal Position (%) Engine Speed (RPM) range ITV Movement ITV Rate (%/sec)
1 Vehicle Launching 80-100 800-1600 Fast ITV Opening 200
2 Acceleration 80-100 1600-2400 Fast ITV Opening 200 to 150
3 Deceleration 0 1600-3500 Fast ITV closing -200
4 Up-hill (Ghat) climbing 100 3100-3500 Slow ITV opening 80 to 30
5 City running 0-100 1600- 2400 Fast ITV opening & closing 200 to -200
6 Highway running 20-50 1600- 2400 Moderate ITV adjustment 100 to 150
7 Engine Overrun 0 1600-3500 Fast ITV closing -200

Example: 2

Vehicle specifications/Details:
• Vehicle Model ? Eicher Pro2114XP CNG BS6
• Vehicle Type ? Truck
• Application ? Highway
• Max vehicle speed ? 80 km/hr
• Max Gross Vehicle Base (GVW) ? 16 tons

Engine specifications/Details:

• Engine Name ? E494 TCIC CNG BS6
• Engine Swept Volume/Capacity (Lit) ? 3.8 Lit
• Max Torque ? 450 Nm @ 1600 RPM
• Rated Power ? 100 kW @ 2400 RPM
• Minimum engine speed (RPM) ? 800
• Maximum engine speed (RPM) ? 2800
ITV Logic in conventional EMS logic/mechanism: Single valve for entire engine/vehicle operating range

• ITV opening rate ? 80 %/sec,
• ITV closing rate ? -100 %/sec
ITV Opening rate table (data in %/sec)
X-Axis: Engine Speed (RPM)
800 1600 2000 2400 2600 2800
Y-Axis: Pedal Position (%) 100 150 150 120 60 20 20
80 150 150 120 60 20 20
50 120 120 100 80 80 80
20 80 80 80 100 100 100
10 50 50 80 100 100 100
0 50 50 80 80 80 80
[009] ITV Logic with new EMS logic/mechanism: Two dimensional maps on the basis of engine RPM and pedal position for ITV opening and closing rate.

ITV Closing rate table (data in %/sec)
X-Axis: Engine Speed (RPM)
800 1600 2000 2400 2600 2800
Y-Axis: Pedal Position (%) 100 -100 -100 -80 -60 -20 -20
80 -100 -100 -80 -60 -20 -20
50 -100 -100 -100 -80 -80 -80
20 -100 -100 -100 -100 -100 -100
10 -100 -120 -120 -120 -120 -120
0 -120 -150 -150 -150 -150 -150

Note: In case of RPM/pedal position other than values mentioned in the table, EMS will do take inputs by interpolating the data.

DESCRIPTION OF DRAWINGS
[0010] The present invention relates to a multi-dimensional intake throttle valve (ITV) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response and method of manufacturing thereof.
[0011] FIG. 1 describes air flow control mechanism in CNG engines.
[0012] FIG. 2 show existing or conventional mechanism for ITV Control.
[0013] FIG. 3 shows a multi-dimensional intake throttle valve (ITV) control system.
[0014] The FIG. 1 describes air flow control mechanism in CNG engines.
[0015] The following are the critical components of multi-dimensional intake throttle valve control system
a. A spark-ignition (SI) engine is an internal combustion engine, where the combustion of the air-fuel mixture is ignited by spark from spark plug. SI engines are different compared to compression-ignition (CI) engines (typically diesel engines), where the combustion start by auto-ignition of fuel, injected directly into the compressed hot air inside combustion chamber, without needing any external spark. The CNG engines comes in SI engine categories.
b. Engine Management System (EMS): An EMS also called Engine Control Unit (ECU) or Engine Control Module (ECM). The EMS receives inputs form various sensors and gives command to series of actuators, including ITV, to ensure optimal engine performance. Here the EMS developed by the present subject matter maintain the air fuel ratio in CNG 17.2 kg/air, which is the critical components to provide precise air flow control and smoother vehicle response.
c. Intake Throttle Valve (ITV): ITV also known as intake throttle, throttle body, electronic throttle body (ETB). In CNG engine, ITV is the most important component of intake air system that controls the amount of air flowing into the engine in response to driver accelerator pedal demand. It is located just before intake manifold. The main part of ITV is a throttle plate, which is a butterfly valve that regulates the air flow.
d. Steady-State Engine Operation: Steady-state is a condition where engine speed and torque output remain relatively steady and unchanging. During steady-state, operating parameters such as air flow rate, fuel flow rate, intake/exhaust temperature and pressure remains steady. Vehicle running at highway with steady speed is typical example of steady-state operation.
e. Transient Engine Operation: During transient condition engine speed and torque output varies continuously, results in rapid change in operating parameters such as air flow rate, fuel flow rate, intake/exhaust temperature and pressure. City driving conditions are typical example of transient operation with continuous need of engine acceleration and deceleration.
f. Stoichiometric Air -Fuel Mixture: The stoichiometric air-fuel mixture is ideal ratio of air to fuel that burns all fuel with no excess air. For CNG BS-VI engines, the stoichiometric air–fuel mixture is 17.2:1, e.g. for complete burning of one gram of CNG, 17.2 grams of air are required.
g. Lambda: It represents the ratio of the amount of actual oxygen present inside combustion chamber, or exhaust gases, compared to the air amount that should have been present in order to obtain perfect combustion i.e. stoichiometric air-fuel mixture. In CNG BS-VI engines, value of lambda is measured by a wide band lambda sensor, connected in the exhaust line just after exhaust manifold (in Naturally Aspirated engines) and after turbocharger (in TCIC engines).
[0016] Below is representation of lambda value;
If Lambda (?) = 1 Air-Fuel ratio ? Stoichiometric (17.2:1 for CNG engines)
If Lambda (?) > 1 Air-Fuel ratio ? Lean (i.e. excess air)
If Lambda (?) < 1 Air-Fuel ratio ? Rich (i.e. excess fuel)
[0017] The FIG. 2 illustrated existing CNG BS-VI engines have single fixed valve, stored in EMS, for ITV opening and closing rate. The valve of opening and closing rate of ITV is Calibratable and freeze in EMS memory.
[0018] The FIG. 3 demonstrate a multi-dimensional intake throttle valve (itv) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response and method of manufacturing thereof.
[0019] The present invention allowing a calibratable, variable, value of ITV opening and closing rate, on the basis of engine RPM and accelerator pedal demand by driver. Here the present invention allows desired opening/closing rate of ITV for different vehicle operating modes depending upon accelerator pedal demand by driver. The Table-1 herein below describes an ITV operation in different operating modes. The algorithms to enable this logic in EMS have been developed in-house.
[0020] The below example exemplifies ITV opening rate with conventional and new methods:
[0021] Example: 1
Vehicle specifications/Details:
• Vehicle Model ? Eicher Pro2059XP CNG BS6
• Vehicle Type ? Truck
• Application ? City Plus Highway
• Max vehicle speed ? 80 km/hr
• Max Gross Vehicle Base (GVW) ? 7.5 tons
Engine specifications/Details:
• Engine Name ? E483 NA CNG BS6
• Engine Swept Volume/Capacity (Lit) ? 3.3 Lit
• Max Torque ? 245 Nm @ 1600 RPM
• Rated Power ? 70 kW @ 3100 RPM
• Minimum engine speed (RPM) ? 800
• Maximum engine speed (RPM) ? 3500
ITV Logic in conventional EMS logic/mechanism: Single valve for entire engine/vehicle operating range
• ITV opening rate ? 100 %/sec,
• ITV closing rate ? -100 %/sec

[0022] In one embodiment, the present invention discloses the ITV Logic with new EMS logic/mechanism: Two dimensional maps on the basis of engine RPM and pedal position for ITV opening and closing rate.
ITV Opening rate table (data in %/sec)
X-Axis: Engine Speed (RPM)
800 1600 2400 3100 3200 3500
Y-Axis: Pedal Position (%) 100 200 200 150 80 30 30
80 200 200 150 80 30 30
50 150 150 100 100 100 100
20 100 100 100 100 100 100
10 50 50 100 100 100 100
0 50 50 100 100 100 100

ITV Closing rate table (data in %/sec)
X-Axis: Engine Speed (RPM)
800 1600 2400 3100 3200 3500
Y-Axis: Pedal Position (%) 100 -100 -100 -100 -80 -30 -30
80 -100 -100 -100 -80 -30 -30
50 -100 -100 -100 -100 -100 -100
20 -100 -120 -120 -120 -120 -120
10 -100 -150 -150 -150 -150 -150
0 -150 -200 -200 -200 -200 -200

Note: In case of RPM/pedal position other than values mentioned in the table, EMS will do take inputs by interpolating the data.

Table.1: ITV Movement in Eicher Pro2059XP CNG BS6 vehicle with new EMS logic in different vehicle operating conditions
Sr. No. Operating Mode Pedal Position (%) Engine Speed (RPM) range ITV Movement ITV Rate (%/sec)
1 Vehicle Launching 80-100 800-1600 Fast ITV Opening 200
2 Acceleration 80-100 1600-2400 Fast ITV Opening 200 to 150
3 Deceleration 0 1600-3500 Fast ITV closing -200
4 Up-hill (Ghat) climbing 100 3100-3500 Slow ITV opening 80 to 30
5 City running 0-100 1600- 2400 Fast ITV opening & closing 200 to -200
6 Highway running 20-50 1600- 2400 Moderate ITV adjustment 100 to 150
7 Engine Overrun 0 1600-3500 Fast ITV closing -200

Example: 2

Vehicle specifications/Details:
• Vehicle Model ? Eicher Pro2114XP CNG BS6
• Vehicle Type ? Truck
• Application ? Highway
• Max vehicle speed ? 80 km/hr
• Max Gross Vehicle Base (GVW) ? 16 tons

Engine specifications/Details:
• Engine Name ? E494 TCIC CNG BS6
• Engine Swept Volume/Capacity (Lit) ? 3.8 Lit
• Max Torque ? 450 Nm @ 1600 RPM
• Rated Power ? 100 kW @ 2400 RPM
• Minimum engine speed (RPM) ? 800
• Maximum engine speed (RPM) ? 2800
ITV Logic in conventional EMS logic/mechanism: Single valve for entire engine/vehicle operating range
• ITV opening rate ? 80 %/sec,
• ITV closing rate ? -100 %/sec
ITV Opening rate table (data in %/sec)
X-Axis: Engine Speed (RPM)
800 1600 2000 2400 2600 2800
Y-Axis: Pedal Position (%) 100 150 150 120 60 20 20
80 150 150 120 60 20 20
50 120 120 100 80 80 80
20 80 80 80 100 100 100
10 50 50 80 100 100 100
0 50 50 80 80 80 80
[0023] ITV Logic with new EMS logic/mechanism: Two dimensional maps on the basis of engine RPM and pedal position for ITV opening and closing rate.
ITV Closing rate table (data in %/sec)
X-Axis: Engine Speed (RPM)
800 1600 2000 2400 2600 2800
Y-Axis: Pedal Position (%) 100 -100 -100 -80 -60 -20 -20
80 -100 -100 -80 -60 -20 -20
50 -100 -100 -100 -80 -80 -80
20 -100 -100 -100 -100 -100 -100
10 -100 -120 -120 -120 -120 -120
0 -120 -150 -150 -150 -150 -150

Note: In case of RPM/pedal position other than values mentioned in the table, EMS will do take inputs by interpolating the data.
[0024] Although the present disclosure is described in terms of certain preferred embodiments and examples, other embodiments and examples will be apparent to those of ordinary skill in the art, given the benefit of this disclosure, including embodiments and examples that do not provide all of the benefits and features set forth herein, which are also within the scope of this disclosure. It is to be understood that other embodiments may be utilized, without departing from the true spirit and scope of the present invention.
[0025] It is to be understood that other embodiments of the present disclosure will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described only various embodiments of the disclosure by way of illustration. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.
[0026] It would become abundantly clear to a person in the art, after reading this specification that the present subject matter also multi-dimensional intake throttle valve (ITV) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response and method of manufacturing thereof. More specifically, the present subject matter discloses multi-dimensional intake throttle valve (ITV) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response effectively and without departing from the spirit of the present subject matter. While the subject matter may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described herein. Alternate embodiments or modifications may be practiced without departing from the spirit of the present subject matter. The drawings shown are schematic drawings and may not be to the scale. While the drawings show some features of the subject matter, some features may be omitted. Alternatively, in some other cases some features may be emphasized while others are not. Further, the methods disclosed herein may be performed in manner and/or order in which the methods are explained. Alternatively, the methods may be performed in manner or order different than what is explained without departing from the spirit of the present subject matter. It should be understood that the subject matter is not intended to be limited to the particular forms disclosed. Rather, the subject matter is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter.
Yours Faithfully

ANIL KUMAR PANDEY
(IN P/A 2359)
AGENT FOR THE APPLICANT(S)

,CLAIMS:We claim:

1) A multi-dimensional intake throttle valve (ITV) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response characterized by allowing a calibratable, variable, value of ITV opening and closing rate, on the basis of engine RPM and accelerator pedal demand by driver.
2) The multi-dimensional intake throttle valve (ITV) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response as claimed in Claim 1, wherein said system allows desired opening/closing rate of ITV for different vehicle operating modes depending upon accelerator pedal demand by driver.
3) A method of manufacturing the multi-dimensional intake throttle valve (ITV) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response as claimed in Claim 1, wherein said characterized by allowing a calibratable, variable, value of ITV opening and closing rate, on the basis of engine RPM and accelerator pedal demand by driver.
4) A method of manufacturing the multi-dimensional intake throttle valve (ITV) control system in CNG BS-VI engines for precise air flow control and smoother vehicle response as claimed in Claim 1, wherein said method allows desired opening/closing rate of ITV for different vehicle operating modes depending upon accelerator pedal demand by driver.

Yours Faithfully

ANIL KUMAR PANDEY
(IN P/A 2359)
AGENT FOR THE APPLICANT(S)