FORM 2
THE PATENT ACT 1970 (as amended)
[39 OF 1970]
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
[See Section 10 and Rule 13]
TITLE: “METHOD AND DEVICE OF ACTIVATING PREDETERMINED FUEL
FLOW IN BI-FUEL VEHICLES”
Name and address of the Applicant:
TATA MOTORS LIMITED, an Indian company having its registered office at
Bombay house, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001, Maharashtra,
INDIA.
Nationality: INDIAN
The following specification particularly describes the nature of the invention and the
manner in which it is to be performed.
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TECHINCAL FIELD
Embodiments of the present disclosure relate to bi fuel vehicles. More
particularly, the embodiments relate to activating a predetermined fuel flow in bi fuel
vehicles.
BACKGROUND OF DISCLOSURE
Presently, in most of bi fuel vehicles a separate CNG switch is provided on
dashboard for activation of CNG fuel mode. Activation of the CNG switch sends the
necessary information to CNG controller or EMS ECU. Based upon available inputs from
CNG switch, CNG mass, gasoline volume and conditions of engine, EMS / Controller
decides which fuel mode to be switched on. There is a separate CNG switch for the
activation of CNG mode. Thus a separate hardware is required for the switch and this
switch occupies additional space in the dashboard. Further, mounting additional hardware
will result in additional assembly time. Also due this additional switch the existing dash
board design has to be modified to facilitate this additional switch.
Hence, there is a need of a solution which can simplify the activation of CNG fuel
flow mode and remove the need of the separate CNG switch. Also, it has to be applicable
to any other fuel used in place of CNG.
OBJECTIVES OF THE DISCLOSURE
The objective of the present disclosure is to obtain a simple to use and cost
effective method of fuel selection in a multi fuel vehicle.
Another objective of the present disclosure is to provide a method of activating a
predetermined fuel flow using a single select switch on an instrument cluster of a vehicle.
Another objective of the present disclosure is to provide a device to activate a
predetermined fuel flow using a single switch on an instrument cluster of a vehicle.
SUMMARY
The shortcomings of the prior art are overcome and additional advantages are
provided through the provision as claimed in the present disclosure.
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Additional features and advantages are realized through the techniques of the
present disclosure. Other embodiments and aspects of the disclosure are described in
detail herein and are considered a part of the claimed disclosure.
In one embodiment, the disclosure provides a method of activating a
predetermined fuel flow in a bi-fuel vehicle. The method comprises selecting fuel
selection mode by pressing a select switch located on an instrument cluster of the bi-fuel
vehicle. Also the method comprises activating a non default fuel flow by pressing and
holding the select switch for predefined time duration in the fuel selection mode. The
predefined time duration is defined as below:
1. Short press – Less than or equal to 2 sec.
2. Long press – More than 2 sec.
Further, a default fuel flow is activated upon holding the select switch for time
duration greater than the predefined time duration. The predetermined fuel is selected
from one of compressed natural gas (CNG) and liquefied petroleum gas (LPG). The
default fuel flow is activated when the select switch is held for time duration greater than
2 seconds.
In one embodiment, the disclosure provides a device for activating a
predetermined fuel flow in a bi-fuel vehicle. The device comprises a select switch
integrated on an instrument cluster of the bi-fuel vehicle to select a mode of operation,
fuel mode of operation is selected upon pressing the select switch. Also, the device
comprises a control unit to receive input data from the select switch to determine the
mode of operation selected is fuel select mode. The control unit receives further input
upon pressing and holding the select switch for predefined time duration to activate the
predetermined fuel flow in the bi-fuel vehicle. The control unit is a microcontroller or
engine management system (EMS) engine control unit (ECU) for bi-fuel vehicles with
control area network (CAN) architecture.
The foregoing summary is illustrative only and is not intended to be in any way
limiting. In addition to the illustrative aspects, embodiments, and features described
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above, further aspects, embodiments, and features will become apparent by reference to
the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
The novel features and characteristic of the disclosure are set forth in the appended
claims. The disclosure itself, however, as well as a preferred mode of use, further
objectives and advantages thereof, will best be understood by reference to the following
detailed description of an illustrative embodiment when read in conjunction with the
accompanying figures. One or more embodiments are now described, by way of example
only, with reference to the accompanying figures wherein like reference numerals
represent like elements and in which:
Figure 1 illustrates an instrument cluster of a bi-fuel vehicle, as one embodiment.
Figure 2 illustrates a device block diagram for activating CNG mode in a bi-fuel vehicle,
as one embodiment.
Figure 3 illustrates a method flowchart for activating CNG mode in bi fuel vehicles.
The figures depict embodiments of the disclosure for purposes of illustration only. One
skilled in the art will readily recognize from the following description that alternative
embodiments of the structures and methods illustrated herein may be employed without
departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
The foregoing has broadly outlined the features and technical advantages of the
present disclosure in order that the detailed description of the disclosure that follows may
be better understood. Additional features and advantages of the disclosure will be
described hereinafter which form the subject of the claims of the disclosure. It should be
appreciated by those skilled in the art that the conception and specific embodiment
disclosed may be readily utilized as a basis for modifying or designing other structures
for carrying out the same purposes of the present disclosure. It should also be realized by
those skilled in the art that such equivalent constructions do not depart from the spirit and
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scope of the disclosure as set forth in the appended claims. The novel features which are
believed to be characteristic of the disclosure, both as to its organization and method of
operation, together with further objects and advantages will be better understood from the
following description when considered in connection with the accompanying figures. It is
to be expressly understood, however, that each of the figures is provided for the purpose
of illustration and description only and is not intended as a definition of the limits of the
present disclosure.
Referring now to the drawings wherein the drawings are for the purpose of
illustrating an exemplary embodiment of the disclosure only, and not for the purpose of
limiting the same.
To overcome the drawbacks mentioned in the background, the disclosure provides
a method which uses trip meter knob hereinafter called as select switch on the instrument
cluster for sensing customer requirement of a predetermined fuel flow or fuel mode of
operation such as CNG (Compresses Natural Gas) mode or liquefied petroleum gas
(LPG) in a bi fuel vehicle. Instrument cluster microcontroller recognizes the requirement
of a user based on the input to the modes and select switch to send appropriate signal to a
controller called as CNG Controller or engine management system (EMS) engine control
unit (ECU) for activating the selected fuel.
Exemplary embodiments of the present disclosure provide a method and device
for activating a predetermined fuel flow in bi fuel vehicles using trip meter select switch
of the instrument cluster.
In one embodiment for a Bi fuel vehicle, considering customer needs of fuel
selection, a fuel selector switch is provided on dashboard. The activation of the select
switch sends a signal to a control unit or a controller such as microcontroller or Engine
Management System (EMS), Engine Control Unit (ECU) for selecting a particular fuel
for engine. Based upon different inputs like balance mass of fuel, particular engine
conditions and other parameters, EMS ECU decides the fuel to be used of the vehicle.
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One embodiment of the present invention is a method of activating a
predetermined fuel flow or fuel mode in bi fuel vehicles. The method comprises swiftly
pressing the trip switch or the select switch one of the two modes is selected i.e. either
trip meter mode or fuel selection mode. By pressing the select switch for longer duration,
a predetermined fuel mode is selected. The predetermined fuel is one of natural gas
(CNG) and liquefied petroleum gas (LPG). The function of the fuel selection switch is
integrated in the trip select switch of the instrument cluster. The trip meter switches are
used in instrument cluster to show different displays such as distance covered in
kilometer (Km)/mile for upward journey which is Trip A and downward journey which is
Trip B. The trip meter switch or select switch is used for the purpose of selecting the
mode of operation and thereafter selecting the fuel mode or fuel flow in the fuel selection
mode of operation of the bi fuel vehicles. The method performs CNG mode activation in
bi fuel vehicles using the select switch located on the instrument cluster, as one
embodiment.
Figure 1 illustrates an instrument cluster of a vehicle, as one embodiment. The
instrument cluster 100 comprises select switch 102, CNG indicator 103, LCD display to
show selected mode 101. Also, the instrument cluster comprises other features such as
fuel gauge indicator, ODO meter and other typically known components. In the
instrument cluster, near to fuel gauge a “CNG” telltale or CNG indicator 103 is provided
which indicates that CNG mode is activated.
Figure 2 illustrates a circuit block diagram for activating CNG mode in bi fuel
vehicles 200. The block diagram 200 indicates the circuit connections and signal flow of
the different components. A control unit performs all the control actions based on the
inputs received from the select switch. The control unit is a 16 bit microcontroller 201
used for instrument cluster application, as one embodiment. The microcontroller support
the input analog, digital, pulse width modulated signals and produces analog, digital,
pulse width modulated signals as output. Also, the microcontroller supports CAN
communication with other ECUs in vehicle electrical system. The communication
between the microcontroller and Engine Management System (EMS), Engine Control
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Unit (ECU) 202 is established using CAN transceiver 203 and other necessary
application modules.
In one embodiment, the select switch as shown in the figure 2 is a simple non
latchable micro switch. The switch is directly mounted on PCB of instrument cluster and
gives direct input to microcontroller which activates predefined application.
Figure 3 is a flowchart illustrating the method of activating a predetermined fuel
mode or fuel flow in bi fuel vehicles. Upon pressing the select switch, micro switch gets
activated on PCB. The micro switch in turn provides input to microcontroller. If the
select switch is pressed for time duration less than 2 seconds (short press), one of the
modes defined in the vehicle is selected. For example, when the select switch is pressed
various mode like trip mode A, trip mode B, fuel consumption per km/mile mode, fuel
selection mode etc can be selected. A display menu on the LCD display of the instrument
cluster will display the mode been selected i.e. trip meter mode A (upward journey), trip
meter mode B (downward journey) and fuel selection mode.
In one embodiment, if the selected mode of operation is trip meter mode then one
can select trip A, trip B and reset trip readings. In this mode, if the select switch is
pressed for short time, display toggles between Trip A and trip B. If the select switch is
pressed for longer time then displayed trip meter is reset to zero.
In one embodiment, if the selected mode of operation is fuel selection mode then
selection of CNG fuel can be set. If the select switch is pressed for short time, then input
is ignored and vehicle runs in gasoline mode. If the select switch is pressed for longer
time i.e. long press greater than 2 seconds then CNG mode is selected. Accordingly CNG
mode flag is set in the cluster application and a signal is sent to CNG controller or EMS
ECU. Based upon inputs i.e. CNG mode flag the CNG controller or EMS ECU decides
fuel selection and sends back confirmatory message to the instrument cluster. After
receiving confirmation from EMS ECU regarding setting “CNG mode”, instrument
cluster turns on “CNG” symbol on the cluster.
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In one embodiment, if the fuel mode of operation has to be reset i.e. the fuel mode
of operation has to get back to the gasoline, the select switch should be pressed for time
duration greater than 2 seconds once again. The pressing of the select switch for greater
than 2 seconds will send information to the controller or EMS ECU for resetting fuel
mode to gasoline. Also, at the same time the controller performs the turning off action of
the “CNG” symbol on the instrument cluster. In the instant example, the default fuel is
gasoline. However, this example does not impose a limitation that CNG has to be a
default fuel. A person skilled in art can envisage various fuel options in fuel selection
mode other than the combinations illustrated in the above example.
In case of any emergency and autonomous CNG mode selection [ON/OFF] by the
controller or the EMS ECU, necessary information is sent to the instrument cluster via
CAN to turn ON / OFF CNG symbol and set/reset the CNG flag in application.
The method and device of activating CNG mode in bi fuel vehicles provide the
following advantages such as a simple and cost effective method of CNG mode selection
using select switch or trip meter knob which exists on the instrument cluster. Thus, the
select switch completely avoids the requirement of another switch on the dashboard. This
would also provide the advantage of not to make any change in designing the instrument
cluster to accommodate additional switch. Thus, the existing instrument cluster can be
used for the bi fuel vehicles. Also, the CAN based instrument clusters can use the method
of activating CNG mode in bi fuel vehicles.
The present disclosure is not to be limited in terms of the particular embodiments
described in this application, which are intended as illustrations of various aspects. Many
modifications and variations can be made without departing from its spirit and scope, as
will be apparent to those skilled in the art. Functionally equivalent methods and devices
within the scope of the disclosure, in addition to those enumerated herein, will be
apparent to those skilled in the art from the foregoing descriptions. Such modifications
and variations are intended to fall within the scope of the appended claims. The present
disclosure is to be limited only by the terms of the appended claims, along with the full
scope of equivalents to which such claims are entitled. It is also to be understood that the
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terminology used herein is for the purpose of describing particular embodiments only,
and is not intended to be limiting.
With respect to the use of substantially any plural and/or singular terms herein,
those having skill in the art can translate from the plural to the singular and/or from the
singular to the plural as is appropriate to the context and/or application. The various
singular/plural permutations may be expressly set forth herein for sake of clarity.
In addition, where features or aspects of the disclosure are described in terms of
Markush groups, those skilled in the art will recognize that the disclosure is also thereby
described in terms of any individual member or subgroup of members of the Markush
group.
While various aspects and embodiments have been disclosed herein, other aspects
and embodiments will be apparent to those skilled in the art. The various aspects and
embodiments disclosed herein are for purposes of illustration and are not intended to be
limiting, with the true scope and spirit being indicated by the following claims.
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We claim
1. A method of activating a predetermined fuel flow in a bi-fuel vehicle, said method
comprising:
selecting fuel selection mode by pressing a select switch located on an instrument
cluster of the bi-fuel vehicle; and
activating a non default fuel flow by pressing and holding the select switch for a
predefined time duration in the fuel selection mode,
wherein a default fuel flow is activated upon holding the select switch for a time
duration greater than the predefined time duration.
2. The method as claimed in claim 1, wherein the predetermined fuel is selected from
one of compressed natural gas (CNG) and liquefied petroleum gas (LPG).
3. The method as claimed in claim 1, wherein the select switch is pressed for a time
duration less than or equal to 2 seconds for selecting the fuel selection mode.
4. The method as claimed in claim 1, wherein the default flow is activated when the
select switch is held for time duration greater than 2 seconds.
5. The method as claimed in claim 1, wherein the default fuel mode is gasoline mode.
6. A device for activating a predetermined fuel flow in a bi-fuel vehicle comprising:
a select switch integrated on an instrument cluster of the bi-fuel vehicle to select a
mode of operation, wherein a fuel mode is selected upon pressing the select switch;
a control unit to receive input data from the select switch to determine the mode
of operation and upon selection of fuel select mode, said control unit receives further
input from the select switch wherein pressing and holding the select switch for a
predefined time duration will activate the predetermined fuel flow in the bi-fuel
vehicle and a default fuel flow is activated upon holding the select switch for a time
duration greater than the predefined time duration.
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7. The device as claimed in claim 6, wherein the predetermined fuel is selected from one
of compressed natural gas (CNG) and liquefied petroleum gas (LPG).
8. The device as claimed in claim 6, wherein the predefined time duration for pressing
and holding the select switch is greater than 2 seconds to select the predetermined
fuel flow.
9. The device as claimed in claim 6, wherein the control unit is a microcontroller.
10. The device as claimed in claim 6, wherein the control unit is engine management
system (EMS) engine control unit (ECU) for bi-fuel vehicles with control area
network (CAN) architecture.