FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
A Novel Engine Start Stop Controller
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS Mr. Dattatraya Katkar, Mr. D S Kulkarni, Mr. N B Khandarkar
all Indian nationals
of TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION:
This invention deals with start stop function in automotive vehicles used for improving fuel consumption during city driving conditions. Move particularity it deals with an add on type of device that can be used on vehicles that are primarily not developed with start stop system.
BACKGROUND OF INVENTION:
Currently use of automobiles has become a necessity which was a luxury in the past. Rising fuel praises and environmental concerns are two major challenges to the automotive industries facing today's. In addition, traffic congestion & lower average vehicle speeds during traffic in the urban areas are some of the local issues that pose additional challenge from fuel consumption point of view. Vehicle start-stop system is one simple and cost effective means of addressing the fuel consumption during traffic congestion. Automotive manufacturers are providing start-stop system as feature in vehicles. However, the start-stop systems are affected with new vehicles. New vehicles form a very small fraction of total fleet of vehicles. On the other hand old vehicles form a significant fraction, Any attempts to improve fuel consumption in old vehicles will have a positive impact to fuel conservation & environmental point of view. Thus the present patent aims at providing an add or system that will indicate the driver all out the suitable condition to stop the vehicles at idle. The device also ensures that the vehicle starting system and are also protected from wear arising from very frequent start-stop operations.
PRIOR ART:
Considerable amount of work has been done in the past for vehicle speed limiting on electronically controlled fuel injection system in dlesel engines,
US 6834 632 B2 explains about a stop and start control apparatus of an internal combustion engine that prevents fuel supplied in specific cylinder at the time of stopping the engine from being discharged in an unburned state. When an ignition switch is turned off in a state that the unburned fuel is sealed in the combustion chamber of a specific cylinder during idling stop, the unburned fuel is combusted to prevent the unburned fuel from being discharged. The vibration occurring at that time can be suppressed by rotating the motor generator in the counter direction to the rotation direction of the crankshaft. After the unburned fuel is sealed in the combustion chamber of a specific cylinder if it is estimated that the unburned fuel is discharged, the exhaust valve corresponding to the specific cylinders closed at the predetermined timing, or the unburned fuel is combusted, whereby the unburned fuel is prevented from being discharged. Thus, deterioration of emission can be avoided.

As per US patent 650259 Bl an engine automatic start stop control apparatus controls an engine of a vehicle to be automatically stopped or started in response to driving conditions of the vehicle. Particularly, the apparatus is applied to the vehicle that performs idle stop control for reduction of discharge gas. Herein, the apparatus controls the engine to restart based upon determination for restarting the engine under an engine stop mode. Namely, the apparatus controls the engine to . restart if a driver depresses a clutch pedal or a driver does not depress a brake pedal during the engine stall in which engine speed becomes zero. Thus, it is possible to restart the engine by prescribing even if the driver mistakenly recognizes that the engine is stopped by automatic stop control although the engine actually stalls due to an error of the driver so that the engine speed becomes zero. This improves the drivability for the driver who handles the vehicle particularly a hybrid vehicle which is capable of independently running by using an electric motor only.
US patent 6532926 Bl explains an engine automatic start stop control device for controlling an engine of a vehicle to be automatically stopped or started in response to driving conditions of a vehicle, which is equipped with manual transmission, automatic transmission or a continuously variable transmission (CVT). The apparatus makes a determination whether or not to allow a relationship between outside air temperature & engine water temperature. This prevents a catalyst from being deteriorated in performance as a resuit of a temperature reduction of the catalyst occurs when the engine idling is carelessly stopped. Thus, it is possible to effectively reduce discharging gas of the vehicle. The outside air temperature can be estimated based on intake air temperature which is detected after the vehicle runs for a prescribed time. The idle stop of the engine is of the engine is inhibited in response to a request from an air conditioner or to avoid cool-down of the engine to be restarted. In addition, the idle stop of the engine is allowed or inhibited in consideration of the remaining battery charge, particularly in case of hybrid vehicle which is equipped with a motor / generator in addition to the engine. The engine is automatically restarted to avoid unwanted reduction of remaining battery charge.
US patent 5653659 explains an automatic engine stop-start system which automatically stops an engine to reduce the fuel consumption whenever a predetermined condition is fulfilled. The system is particularly arranged to detect gearshift lever position of an automatic transmission to determine various stop start conditions so that an engine in a car with an automatic transmission can be automatically stopped/started.
The first patent primarily deals with the start stop controller from unburnt fuel in the engine during engine stop. The second and third patent primarily deal with start stop controls for hybrid vehicle and vehicle having CVT. These patents also deal with various parameters based on which the start stop function is decided. The last patent deals with an automatic starts top system which detects the gear position along with the other set of conditions. All the above patents deal with various

conditions and features for an efficient start stop system. However, none of the above patents deal about the actual stop time after an automatic engine stop. The starts top system becomes in effective irrespective of the intelligent engine stop strategies if the stop time is less and the fuel saved in a stop is less than the cranking fuel including electrical load. Thus in order the automatic start stop system becomes effective, it needs to take into account the estimate of stop time. The estimated stop time is a traffic and situation dependent phenomenon and the input regarding this parameter can be given by the driver. The present invention aims at capturing this input.
OBJECT OF THIS INVENTION:
The main object of the present inventions is to obviate the above mentioned drawbacks.
Another object of the invention is to provide a system and device that will indicate the vehicle
driver regarding the condition suitable for stopping the vehicle at idle.
Yet another object of the present invention is to provide a system and a device that is of add on
type and can to be retrofitted in the in use vehicles.
Yet another object of the present invention is to provide a device that takes into account the engine
cranking performance before suggesting start-stop function.
Yet another object of the present invention is to provide a system and a device to indicate the
vehicle driver stop indication that is simple and cost effective
SUMMARY OF INVENTION:
A Novel Engine Start Stop Controller comprising: an engine mounted in a vehicle, a switch installed in signal line between said engine start stop controller and fuel shut off solenoid, said start stop controller receive inputs from vehicle speed sensor, neutral switch, coolant temperature sensor, engine speed, battery state of charge, a fuel supply circuit having said fuel shut off solenoid installed in low pressure side of said fuel circuit, said fuel shut off solenoid cuts off fuel supply once it receives signal from said start stop controller, said start stop controller sends signal for cut off of fuel supply based on said inputs received.
The switch is a push type switch mounted on dashboard. The switch is normally closed type and after pressing it opens the electrical circuit and acts as a timer switch and is tuned for start stop application. The switch turns back to its normal position after a predetermined time and said start stop system functions normally. The said switch has a central contactor which is in electrical contact with the sensor signal through outer contactors such that when knob is pressed it causes an electrical discontinuity in electrical circuit. The switch has a return mechanism through spring to bring back central contactor to its original position and time for restoring original position is determined by said spring and damping characteristics.

A method of controlling engine start - stop action comprising acts of receiving signals of engine speed, vehicle speed, engine coolant temperature, engine cranking time, battery state of charge, input from switch by said controller, displaying engine stop signal and/ or providing audio signal to driver, stopping the vehicle depending of received signals in case of idling beyond a previously calculated time period by cutting fuel supply to said engine, suspending start-stop function in case engine cranking time is more than specified period.
The controller is also capable of being configured to handle additional variables like Idle stop delay, Idle fuel consumption and Cranking time upper threshold.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as further objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accord with the present invention when taken in conjunction with the accompanying drawing wherein:
Fig. 1 shows the typical electrical connections for start stop system in an automotive vehicle.
Fig. 2 shows the electrical connections for an automotive vehicle incorporating a start stop
indicator in accordance with the present invention.
Fig. 3 shows the schematic details of the electronic controller for stop start indication.
DETAILED DESCRIPTION OF THE INVENTION:
The instant disclosure describes about a device to indicate time to stop the vehicle engine during idle stop condition comprises of an electronic controller which receives vehicle stationary & engine idle signal. It also receives the engine coolant temperature exceeds a set threshold; the electronic display indicates the engine stop signal and provides an audio signal to the vehicle driver accordingly. The electronic controller also monitors engine cranking time during every start operation. If the cranking time exceeds a set cranking threshold the controller detects it is a weak battery or the engine problem and suspends the start-stop indication.
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.

As shown Fig. 1, the schematic of electrical connections for a vehicle having start stop system comprises of an engine (11) which is mounted in the vehicle boundary. Start stop controller (12) receives signals from vehicle speed sensor (13) neutral switch (14), coolant temperature sensor (15), engine speed (16), battery state of charge (17) . If the engine is idling for a period longer than the predetermined time, the controller shuts off fuel supply solenoid (18) through signal (19). The fuel shut off solenoid is installed in the low pressure side of the fuel circuit. In addition, the start stop controller (12) also receives input of engine coolant temperature , battery state of charge.
As shown in fig. 2, the start stop indication system inline with the present invention is similar to the system as explained in fig. Land in addition, it comprises of a push type switch (21) that is installed in the signal line between electronic controller (12) & the fuel shut off solenoid (15). The push type switch is mounted on the dashboard which is easily accessible to the driver. The push type switch is normally closed type and after pressing it opens the electrical circuit. The switch is a timer switch whose settings are tuned for start stop application. The switch turns back to its normal position after a predetermined time and thus, the after this time the start stop system functions normally & a particular stop, which is of very short duration is avoided. Thus, it stops the electrical signal going to the fuel solenoid. The push type switch (21), if pressed once again retains its original position. Thus, with this arrangement, it is possible to suppress the engine stop operation at a particular halt. When the vehicle comes to a halt at traffic which is of short time duration, the driver can press the push switch. There by the engine stop function is temporarily disabled only for a particular stop.
As shown in fig. 3, the timer switch (21) comprises of timer switch central contactor (31) which is in electrical contact with the sensor signal (19) through outer contactors (32). Timer switch is pressed through the knob (33) which causes an electrical discontinuity in the electrical circuit. The timer switch has a return mechanism through spring (34) which brings back the central contactor to its original position. The time for restoring the original position is determined by the spring & damping characteristics. Alternately, the timer switch is of electrical type.
As shown in fig. 4, the electronic unit of the stop start controller in accordance with the present invention comprises of a microprocessor based unit, which is capable of receiving multiple inputs. During vehicle operation when the engine coolant temperature exceeds the set threshold temperature & the engine remains in idle for more than a set time threshold, the start stop controller provides a command of engine stop by cutting the supply to the fuel cut off solenoid. This electronic controller also counts the time for which the engine was stopped by after indicating the stop signal. The electronic controller (12) receives following inputs (41) -
i) Engine speed
ii) Vehicle speed.

iii) Engine coolant temperature iv) Engine cranking time v) Battery state of charge, vi) Push switch ( driver input) The controller is also capable of being configured with the following variables (42). i) Idle stop delay ii) Idle fuel consumption iii) Cranking time upper threshold.
Based on inputs and the programmed parameters, The electronic controller (12) decides the out put action (43 ) - Engine stop signal to the fuel shut off solenoid.
The idle delay represents the time for which the engine needs to be kept on in idle after the vehicle comes to halt. The average warm engine idle fuel consumption is used to calculate the amount of fuel saved during engine stopping. The electronic controller also monitors the time required for each crank and compares it with cranking time upper threshold. The engine cranking time is taken as an indicator of engine and electrical system health. When the engine cranking time exceeds the upper threshold, (due to improper electrical system or improper engine system or drained battery) the electronic controller disables the engine stop indications.
If the engine is stopped, the electronic controller calculates the time for which the engine is stopped. This is further used to calculate the amount of fuel saved in each such stop and cumulative fuel saved. The electronic controller is also provided with push switch with which overrides the engine stop for a particular case.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

Claims:
We Claim:
1. A Novel Engine Start Stop Controller comprising:
- an engine mounted in a vehicle,
- a switch installed in signal line between said engine start stop controller and fuel shut off solenoid
- said start stop controller receive inputs from vehicle speed sensor, neutral switch, coolant
temperature sensor, engine speed, battery state of charge,
- a fuel supply circuit having said fuel shut off solenoid installed in low pressure side of said fuel circuit,
- said fuel shut off solenoid cuts off fuel supply once it receives signal from said start stop controller,
- said start stop controller sends signal for cut off of fuel supply based on said inputs received.

2. The system as claimed in claim 1 wherein said switch is a push type switch mounted on dashboard.
3. The system as claimed in claim 1 wherein said switch is normally closed type and after pressing it opens the electrical circuit and acts as a timer switch and is tuned for start stop application,
4. The system as claimed in claim 1 wherein said switch turns back to its normal position after a predetermined time and said start stop system functions normally.
5. The system as claimed in claim 1 wherein said switch has a central contactor which is in electrical contact with the sensor signal through outer contactors such that when knob is pressed it causes an electrical discontinuity in electrical circuit.
6. The system as claimed in claim 1 wherein said switch has a return mechanism through spring to bring back central contactor to its original position and time for restoring original position is determined by said spring and damping characteristics.
7. A method of controlling engine start - stop action comprising acts of:

- receiving signals of engine speed, vehicle speed, engine coolant temperature, engine cranking time, battery state of charge, input from switch by said controller,
- displaying engine stop signal and/ or providing audio signal to driver,
- stopping the vehicle depending of received signals in case of idling beyond a previously
calculated time period by cutting fuel supply to said engine,

- suspending start-stop function in case engine cranking time is more than specified period.
8. The method as claimed in claim 7 wherein said controller is also capable of being configured to handle additional variables like Idle stop delay, Idle fuel consumption and Cranking time upper threshold.
9. A Novel Engine Start Stop Controller and method of controlling the same substantially as hereinabove described with reference to the accompanying drawings.