FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See Section 10; rule 13)
TITLE OF THE INVENTION
Automated Manual Transmission for gear and clutch actuation with
common power source
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
INVENTOR
Mr. Deepak R R
Indian national
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 particularly describes the invention and the manner
in which it is to be performed.

FIELD OF INVENTION
The invention relates to a common hydraulic power source for power steering system and Automated Manual Transmission (AMT) for gear and clutch actuation of an automotive vehicle and more particularly to AMT with hydraulic actuation system which is connected in series with flow relationship between a source of fluid and a power steering system.
BACKGROUND OF THE INVENTION
The present automobiles having power steering system are assisted either by hydraulic or electrical means. Most of the vehicle presently operates with hydraulically assisted systems.
The customer is in constant need for comfort in case of gear shifting and clutch actuation has lead to automation of these gear boxes and clutch actuation. In the existing system best feasible cheap and efficient way of automating is adaptation of actuators on the gear box and clutch housing and controlled by electronic means. This system adopted on the gear box is called as automated manual gear boxes (here after called as AMT). Most of these actuators in AMT on present vehicle are hydraulically operated and they need some power source for there operation. The power source for the present AMT is provided by additional pump driven by a separate electrical motor. Thus requiring to have two different pumps for two systems and an additional motor and reservior. Additional capacity battery is required to power the motor, (i.e. power steering system and AMT). This is a costly affair and loss of power because of power steering, pump simply driven by the engine throughout in vehicle running condition even when not necessary.
OBJECTIVE OF THE INVENTION
The basic object of the invention to is to obviate the above mentioned drawbacks.
Another object of the invention is to provide a common hydraulic power source to Power Steering system and AMT actuation system.

Another objective of the invention is to monitor the hydraulic system and control the Engine if the hydraulic system fails of function.
Another object of this invention is to provide an AMT actuation system and power steering system to continuously feed with supply of pressurized hydraulic fluid when connected in Series with the hydraulic pump by maintaining uninterrupted flow during the functioning of the systems.
SUMMARY:
An automated manual transmission system for gear and clutch actuation with common power source comprising a pump having a relief valve, a steering gear valve, and an AMT actuation system, said pump being hydraulically connected to said steering gear valve, which is coupled with power steering system; outlet of said steering gear outlet is connected to inlet of fast switching valve, one outlet of said fast switching valve connects to reservoir and another outlet of said fast switching valve connects to accumulator via non return valve; said fast switching valve having a solenoid controls movement of spool valve loaded by spring which is electrically connected with a control module; inlet port of said accumulator is connected to the AMT actuation system and outlet of said AMT actuation system connects back to the reservoir, said control module connected to outlet of said AMT performs control activity by establishing electrical connection with the pressure sensor, on the accumulator and ECU of vehicle, by logging data from these units, said electrical connection is also provided with an alarm.
The fast switching valve is connected in series with the hydraulic circuit of the power steering system for directing the flow from the outlet of the steering gear into two different circuits.
The non return valve holds the pressure in the accumulator, relieving the fast switching valve form continuous pressure, enhancing switching speed.
The accumulator acts as an uninterrupted power source to the AMT actuation system.

The pressure sensor acts as a continuous messenger in monitoring the accumulator pressure.
The control module communicates with number of different sensors and with different outputs in different form, having higher range of voltage and current carrying capacity at a faster sampling and switching rates.
The system have a high rate of safety functioning by communication with SAS (steering angle sensor) and hydraulic pump failure detection logic, programmed into the control module.
The system have a high rate of safety functioning by feed back to vehicle ECU from the control module further conveyed to AMT actuation system to get the vehicle to neutral position with a alarm form manual understanding of failure of the system.
BRIEF DESCRIPTION
The sole FIGURE 1 is a schematic view of Prior Art showing the separate steering system and a separate AMT system with a separate motor, hydraulic pump and a reservoir.
The sole FIGURE 2 of the drawing is a schematic view showing the hydraulic and electrical connection with varies component of the vehicle and the component of the invention.
DETAILED DESCRIPTION
Unlike the prior art the present application, the power steering system and the AMT actuation system is powered by a single source. The single source being a hydraulic pump and the pressure developed by it is used by the power steering system as and when required. When, assistance is not required to the power steering system, pressure is stored

in the accumulator to feed it into the AMT actuation system of the vehicle with the help of a control module.
During sharing of hydraulic fluid or pressure between the AMT actuation system and power steering system, the system is designed in such a way that the function and performance of each other is not hampered. The application simplifies the hydraulic circuit by adding an accumulator which always provides a reserve for at least 15 operation of the AMT actuation system without even affecting the performance of the power steering system. The system also operates within a closed loop on noticing of the hydraulic pump failure It would send a single to engine ECU which in turn command AMT actuation system to shift to neutral position along with the alarm.
The same power source can be used for brake assistance. In absence of AMT the same power source can be used for clutch and gear shift assistance.
Referring now to the drawings, wherein like reference numbers used herein to designate like elements throughout, the various views and embodiments of an Automatic shifting control, system adoptable on automated manual transmission vehicle. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments.
The automatic shifting control system as shown in figure 2 is adoptable on automated manual transmission vehicle consist of a hydraulic pump (5) with a internal relief valve (not shown) mechanically coupled to engine (2). Said pump (5) is connected by means of high pressure hose (6) in series flow relationship with the steering gear valve (7) of the open center type operatively connected to the vehicle wheels. The inlet to the hydraulic pump (5) is connected to the reservoir (3) by means of a low pressure hose (4). The outlet from the said steering gear valve (7) is hydraulically connected to the inlet of fast switching solenoid valve (11) by means of high pressure hose (10). The said fast

switching valve (11) has one inlet and two outlets one connecting the reservoir (3) and other connecting the NRV (non return valve) (13) by means of low and high pressure hose (12) and (14). The said fast switching valve (11) is normally connected between the valve inlet and outlet connected to the reservoir (3) and normally disconnected between valve inlet and the NRV (13) in the non activated condition and vice versa in activated condition. The said NRV (13) is mounted so that the hydraulic flow is only from said High pressure hose (14) to high pressure hose (15) and is blocked in opposite direction. The said high pressure hose (15) is connected to the accumulator (16) to store the oil under pressure. The oil under pressure is stored in said accumulator (16) and is fed to the AMT actuation system (20) unit through high pressure hose (21). There is a low pressure line (22) form the said AMT actuation system (20) connecting back to the said reservoir (3). With this, the system is hydraulically coupled but for operating of the system and system safety, there are electrical and sensor connection needed which are explained with respect to the same drawing 1. The said Fast switching valve (11) operates/activates by means energizing of the solenoid shown on B side of the valve, by means of control module (18) through electrically connection between them. The said control module (18) is also electrically connected to the pressure sensor (17) on the said accumulator (16) and to the SAS (steering angle sensor) (9) on the steering column (not numbered). The said control module (18) is electrical connected with the vehicle ECU (1) for communicating certain inputs and outputs. There is an alarm (19) connected to the control module (18) to trigger in case of hydraulic pump (5) failure.
On a condition 1 when the vehicle is just started and the steering wheel is not turned, the hydraulic pump (5) starts rotating along with the engine (2) delivering the flow into the steering gear valve (7) and back into the reservoir (3) via fast switching valve (11) without any pressure build up. Simultaneously the control module (18) gets details of the Engine (2) rpm and the vehicle speed form the ECU (1) and SAS (9). The control Module (18) is programmed for several logic and to determine certain parameter and controls. Now for above condition (Vehicle speed zero) the Control module (18) will energies the fast switching valve (11) solenoid (not numbered) to shift the internal spool to A side against the spring (not numbered) inside the fast switching valve (11). This shift will

direct the free flowing fluid in the high pressure line (10) towards the NRV (13) via high pressure hose (14) further transmitted to the accumulator (16) via high pressure line (15). Since now the complete system is closed there is a pressure built up in the accumulator (16) .The pressure sensor (17) on the accumulator (16) senses the pressure which is continuously communicated to the Control module (18). There is preset value of pressure determined, on reaching the same pressure the control module (18) disconnects the power supplied to the fast switching valve (11) solenoid. The internal spool slides back to its original position towards B because of the internal spring (not numbered) in the fast switching valve (11). The time required to charge the accumulator (16) is usually 3~ 5 sec for a discharged accumulator (16). Once the accumulator (16) is charged the pressure is maintained in it by means of NRV (13) which would isolate the flow in the return direction, back into the fast switching valve (11). Now the discharge for the pressure in the accumulator (16) is only through the AMT actuation system (20) during its functioning. The time of 3-5 sec is a considerably small time which is not noticed by driver before any automatic gear shifting and steering wheel operation takes place.
On a condition 2 when the vehicle is in motion, as in above condition all things will be same except that the preference is now given to power steering system (8). Now the steering wheel will be working normally giving the full assistance as in case of normal vehicle without any intervention of the hydraulic supply of the fluid into the steering gear valve(7) from the Hydraulic pump(5) and back into the reservoir(3) via fast switching valve (11). The control Module (18) continuously sensing all required parameters, monitors the speed and steering angle form the SAS(9) through ECU(l). Now, the control module (18) will actuate the fast switching valve (11) for charging the accumulator(16) only when the SAS (9) angle is found "zero", the control module (18) identifies this "zero" as non steered condition. And as soon as the SAS (9) is diverted from its zero position that is when steered the control module (18) deactivates the fast switching valve (11) to its original position directing the flow away from the accumulator (16) to reservoir (3) circuitry, there by, functioning as normal power steering system (8).

On a condition 3 when the vehicle is in constant radius curve with steering wheel continuously held in one position. All Other condition would be similar to that of condition 2.0 except that the control module (18) monitors the SAS(9) through ECU (J) and at non "zero" angle of SAS (9) remaining constant for a particular time, means there is no requirement of assistance to the power steering system(8) and would be sensed by the control module (18) and would charge the accumulator 4) by switching the fast switching valve(l 1) and any change in the SAS (9) angle value would deactivate the fast switching valve(8) to work as normal power steering system as in other vehicle.
During all of the above three operating conditions, the control module(18) only charges the accumulator (14) through fast switching valve(ll) if the pressure in the accumulator 17) is below a certain range. Other wise the Control module (18) will not actuate the fast switching valve (11) to charge the accumulator (16). Even at this low pressure value in the accumulator (16) there is reserve for certain number of shifting on the AMT actuation system (20). The Control module (18) always tries to increase pressure constantly in the accumulator (16) till the maximum pressure defined achieved.
On a mode of Safety all the above three condition the control module (18) has a monitoring system in order to monitor the hydraulic pump (5) functioning, by determining pressures build up within the system. This is done as follows. Even with the accumulator (16) in fully charged condition and not discharged due to non shifting of gears inside the AMT actuation system(20) because of the straight road profile and the vehicle is at constant speed, the control module (18) constantly monitors the hydraulic pump(5) by switching the fast switching valve(l4) to micro seconds during the non operative condition of the steering wheel and getting the feedback of the pressure pulse in the accumulator 14) through pressure sensor(17) at different time intervals. In this condition there is almost no charging of the accumulator (13). And during normal charging of accumulator (16) the control module (18) would determine the increasing pressure in the accumulator (6) through pressure sensor(17) which would replicate the healthy condition of the Hydraulic pump(5).

If the pressure surge or pressure build up is not found, the control module (18) would trigger a safety message to ECU (1) which would in turn command AMT actuation system (20) to shift to neutral position along with the alarm (19).
Advantages:
1. The cost of the system comes down.
2. No need for any additional reservoir, electrical motor, pump so less space consumption.
3. The hydraulic pump flow rate being higher instantaneous charging of the accumulator is possible.
4. Safety function helps in detecting pump failure which safe guards the passenger.
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:
1. An automated manual transmission system for gear and clutch actuation with common
power source comprising:
a pump having a relief valve, a steering gear valve, and an AMT actuation system, said pump being hydraulically connected to said steering gear valve, which is coupled with power steering system;
outlet of said steering gear outlet is connected to inlet of fast switching valve, one outlet of said fast switching valve connects to reservoir and another outlet of said fast switching valve connects to accumulator via non return valve; said fast switching valve having a solenoid controls movement of spool valve loaded by spring which is electrically connected with a control module;
inlet port of said accumulator is connected to the AMT actuation system and outlet of said AMT actuation system connects back to the reservoir, said control module connected to outlet of said AMT performs control activity by establishing electrical connection with the pressure sensor, on the accumulator and ECU of vehicle, by logging data from these units, said electrical connection is also provided with an alarm.
2. The system as claimed in Claim 1, wherein said fast switching valve is connected in series with the hydraulic circuit of the power steering system for directing the flow from the outlet of the steering gear into two different circuits.
3. The system as claimed in Claim 1, wherein said non return valve holds the pressure in the accumulator, relieving the fast switching valve form continuous pressure, enhancing switching speed.
4. The system as claimed in Claim 1, wherein said accumulator acts as an uninterrupted power source to the AMT actuation system.
5. The system as claimed in Claim 1, wherein said pressure sensor acting as a continuous messenger in monitoring the accumulator pressure.

6. The system as claimed in Claim 1, wherein said control module communicates with number of different sensors and with different outputs in different form, having higher range of voltage and current carrying capacity at a faster sampling and switching rates.
7. The system as claimed in Claim 1, wherein said system have a high rate of safety functioning by communication with SAS (steering angle sensor) and hydraulic pump failure detection logic, programmed into the control module.
8. The system as claimed in Claim 1, wherein said system have a high rate of safety functioning by feed back to vehicle ECU from the control module further conveyed to AMT actuation system to get the vehicle to neutral position with a alarm form manual understanding of failure of the system.
9. Vehicles having automatic shifting control system, adoptable on automated manual transmission vehicle as claimed in claims 1 to 8.
10. Automated manual transmission system for gear and clutch actuation with common
power source substantially as herein described with reference to accompanying drawings.