STARTER RECRANKING CONTROL SYSTEM

Field of invention:

The present invention relates to starter recranking control system for an automotive vehicle and more particularly to an automotive starter relay control system constructed to de-energize and deactivate the starter relay and disable the starter motor, whenever the engine is in running condition and the motor vehicle is re-started inadvertently.

Background of invention:

Normally, the energisation of a coil in a starter relay turns the starter relay on, so that power from a battery is supplied to a starter motor to activate it. The activating of the starter motor makes an engine start. The activating of the starter motor causes the crankshaft of the engine to start to rotate. Specifically, when vehicle driver operates a starter switch to turn it on, the switch causes to turn the switching member on, allowing a current to flow through the coil. The current flowing through the coil turns the starter relay to on condition.

Starter motors are frequently employed to start the internal combustion engines in a vehicle. Controlling for starting of an engine is necessary, in order to improve the functionality of the automobiles. To prevent serious damage to the engine, the starter motor and the starter-motor-engagement mechanism, it is mandatory that the starter motor be deenergized and disengaged upon engine "start". It is equally important that the starter motor be not energized while the engine is in the running mode. Therefore, a control system having a circuit which will automatically deenergize the starter motor upon engine "start" is necessary to prevent the reenergization of the starter motor while the engine is in the running mode. Upon such an occurrence, meshing of the pinion and ring gears may result in unwanted effects and affects the starter performance.

Typically, a vehicle engine has a starter motor which is activated by the start or ignition switch through a electric starter relay when the switch is engaged. In general, the start or Ignition switch deliver the electric power to energize the starter relay if the switch is in "start" position. In this occurrence, the starter relay will be responsible for transmitting power to the starter motor. The starter motor will then provide transitional and rotational movement to a starter pinion gear which then meshes and engages with the ring gear of an engine crankshaft.

Fig. 1 shows the conventional circuit diagram of starting System in a vehicle in accordance to a prior art. The conventional starting and charging system has a starter motor (3) driveable by engaging with gear (6) of engine (4). An alternator (5) has driven by a belt connecting pulley (7) of engine 4 and rotor (8) of the alternator (5). The starter-motor-solenoid-operated switch (10) has two coils (11) and (12) connected across the battery (2) through electric starter relay (20). In the conventional starting circuit, the negative side of the starter relay coil has been connected directly to the ground potential (1) and to negative terminal of the battery (2) through the starter circuit. The vehicle will be started, when the vehicle operator turn the ignition key to the "start" position. When the ignition key is in "start" position, energisation of starter relay coil (21) takes place through a circuit.

However, the starting systems of vehicles do not disengage the starter motor after engine start-up. Hence, the starter motor can engage the pinion gear to the ring gear of the engine even after the vehicle is running, which is undesirable. Recent advances in engine vibration reduction knock control, and exhaust systems have reduced the amount of noise made in the vehicles when the vehicle is in running condition.

As a result, inadvertent starts are often caused by vehicle operators since they are unable to ascertain whether the engine is running. Further, such engagement may result in unnecessary noise to the vehicle operator and wear may be imparted on the gears. Furthermore, prolonged engagement between the pinion gear and ring gear when the ignition is in the "start" position may also result in complete failure of starter motor. Thus the conventional starter arrangement is not suitable to smooth operation of the vehicle.

Therefore, it is desirable to provide an improved control system with starter recranking protection circuit which overcomes the disadvantages of the conventional starter arrangement and providing starter recranking protection whenever the vehicle is started inadvertently.

Object of the invention:

The main object of the present invention is to provide an improved starter recranking control system which overcome the disadvantages and eliminating the problems associated with the prior art.

Another objet of the present invention is to provide an improved starter recranking protection circuit to avoid recranking of engine whenever the vehicle is started inadvertently.

Another object of the present invention is to provide an improved starter recranking protection circuit which avoids energisation of the starter relay whenever the vehicle is started inadvertently.

Another object of the present invention is to provide an improved starter recranking protection circuit which prevents reengagement of starter motor while the engine is in the running mode.

Further object of the present invention is to provide a method for controlling a starter relay for an engine to deactivate the starter relay upon engine start, when the engine is running condition.

Summary of the invention:

The present invention which achieves the objectives relates to the starting recranking control system which automatically disconnects the starter motor upon engine "start" and prevents the reengagement of starter motor while the engine is in the running mode. This is achieved by the de-energisation of starter relay which is responsive to the L or WL terminal's output potential magnitude of an alternator driven by the cranked engine.

The starter recranking control system provided for the internal combustion engine has a starter motor for cranking an internal combustion engine. A starter relay is arranged to connect the starter motor with an alternator such that the starter relay coil is grounded with a terminal of the alternator through a blocking diode and the terminal gives out positive output potential in the alternator running condition. Whenever the engine is in running condition and the vehicle is re-started inadvertently, an equal positive voltage is developed at the both sides of the relay coil such that the starter relay is deactivated and the starter motor is disabled. This enables the control system to de-energize and deactivate the starter relay upon re-starting the engine inadvertently.

The deactivation of the starter relay achieved by grounding the starter relay coil through L or WL terminal of the alternator via a blocking diode in series. This blocking diode to be used in the vehicle system wiring harness for the reverse current protection. Basically L or WL terminal of the alternator gives out positive output potential during alternator running condition. If the vehicle operator inadvertently re-starts the vehicle when the engine is running, equal positive voltage developed at the both sides of relay coil deactivates the starter relay which in turn disables the starter motor. Conventionally, L or WL terminal of the alternator goes to one side of the dash warning lamp and the other side of the lamp is connected to the ignition side of the ignition switch.

The present invention provides for a starter control system, a method for controlling a starter relay for an engine that is equipped with starter, starter relay and ignition switch. The starter control system will deactivate the starter relay upon engine "start" and if the operator of a vehicle attempts to re-start the vehicle when the engine is running conditions. The deactivation of the starter relay will thereby prevent engagement of the starter pinion gear to the ring gear of the engine, potentially reducing wear on the starter and grinding of the pinion gear to the ring gear when engaging the gears at a high RPM.

The starter recranking protection circuit according to the present invention eliminating the problems associated with the prior art and avoid recranking of engine whenever the vehicle is started inadvertently. The improved starter recranking protection circuit avoids energisation of the starter relay and prevents reengagement of starter motor while the engine is in the running mode. This safe operation starting and recranking protection of engine allows for improving the performance and life of the vehicle.

Brief description of the drawings:

The drawings being referred herein are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.

Fig. 1 shows the circuit diagram of conventional Starting System in a vehicle in accordance to a prior art.

Fig. 2 shows the circuit diagram of the illustrating the protective starting control circuit, in accordance to the exemplary embodiment of the present invention.

Detailed description of the invention:

The present invention relates to starter recranking control system for an automotive vehicle constructed to de-energize and deactivate the starter relay and disable the starter motor, whenever the engine is in running condition and the motor vehicle is re-started inadvertently.

The starter recranking control system provided for an internal combustion engine has a starter motor for cranking the internal combustion engine. A starter relay arranged to connect the starter motor with an alternator such that the starter relay coil is grounded with a terminal of the alternator through a blocking diode and the terminal gives out positive output potential in the alternator running condition. Whenever the engine is in running condition and the vehicle is re¬started inadvertently, an equal positive voltage is developed at the both sides of the relay coil such that the starter relay is deactivated and the starter motor is disabled. This enables the control system to de-energize and deactivate the starter relay upon re-starting the engine inadvertently.

Fig. 2 shows the circuit diagram of the illustrating the protective starting control circuit, in accordance to the exemplary embodiment of the present invention. The starting and charging system of a vehicle consists of starter motor (3), internal combustion engine (4), alternator (5) and battery (2). The starter motor (3) is driveable by engaging with the gear (6) of engine (4). The alternator (5) is driven by a belt connecting pulley (7) of engine (4) and a rotor (8) of alternator (5). The starting system schematic is the combination of DC potential, for example a storage battery (2), starter motor (3) connected through the normally open contacts of a starter-motor-solenoid-operated switch (10) having coils (11) and (12) and two normally open contact, movable contact (13) and stationary contact (14), an internal combustion engine (4) to be cranked thereby and an alternator (5) driven by the cranked engine (4).

The starter-motor-solenoid-operated switch (10) hereinafter referred to as a starter solenoid has two coils (11) and (12), such that the coil (11) the "pull-in" coil which, when energized, closes the movable contact (13) to stationary contact (14) and the coil (12) a "hold-in" coil which maintains movable contact (13) in electrical contact with stationary contact (14) after "pull-in" coil (11) is shorted out by the closed contacts. The operating coil (11) of solenoid-operated switch (10) is connected across the battery (2) through the normally open contact (22) of an electric starter relay (20), through a circuit which may be traced from the positive polarity terminal of battery (2), through leads (28) and (29), normally open contact (22) of electric starter relay (20), operating coil (11), lead (28), cranking motor (3) and point of reference of ground potential (1) to the negative polarity terminal of battery (2). "Hold-in" coil (12) of solenoid-operated switch (10) is also connected across battery (2) through the normally open contacts of relay (20).

The vehicle will be started, when the vehicle operator turn the ignition key to the "start" position. When the ignition key is in "start" position, energization of starter relay coil (21) takes place through a circuit which may be traced from the positive polarity terminal of battery (2), through leads (28), (29) and (30), ignition key, positive side of the starter relay coil (21a), negative side of the starter relay coil (21b) and point of reference of ground potential (1) to the negative polarity terminal of battery (2).

The alternator (5) supplies power to the vehicle electrical system after driven by engine (4).The alternator is a three-phase alternator having three output windings (5a), (5b), and (5c), main output diodes (21), (22), (23), (24), (25) and (26) and regulator (35), for regulating the output of alternator.

The field current supply to the field coil (9) of the alternator's rotor is provided from two different sources from the alternator itself, via "auxiliary diodes" or "diode trio" (16), (17) and (18) and from the battery (2), via alternator warning lamp (19). The alternator warning lamp (19) is the indication of vehicle charging system usually present in the vehicle dash.

The diode trio (16), (17) and (18) consists of three diodes, one per phase. When the vehicle operator first get in the vehicle and turn the ignition key on, the ignition switch is in "ign" position, the engine is not running and the alternator (5) is not spinning. At this time, the current source for the field current is from the battery (2), through the ignition switch "ign" position and through the warning lamp (19). The warning lamp (19) will light ON during this condition. After the engine (4) is started, and the alternator (5) is up to speed, the output of the diode trio (16, 17, 18) is fed back to the regulator (9), and serves as a source of current for the field current. At this time, the output of the diode trio (16, 17, 18) makes to produce positive potential at the L terminal of the alternator (5). Due to this, there exists an equal positive potential at the both sides of the warning lamp (19). So, the warning lamp light goes OFF, when the alternator (5) is running, self sustaining, and the battery (2) is no longer needed to power the vehicle electrical system.

The starter recranking control system according to the present invention, the positive side (21a) of the starter relay (21) is connected to ignition switch "start" position. The negative side (21b) of the starter relay (21) is connected to L or WL terminal of the alternator (5) via blocking diode (34). The blocking diode (34) to be used in the vehicle system wiring harness used for the reverse current protection. The alternator (5) is driven by the cranked engine (4). Starter relay contact (22) is connected to starter motor.

The alternator L or WL terminal indicates whether engine (4) is in running condition or not. Prior to the engine rotation, the zero potential exist at the L or WL terminal of the alternator (5). Now, when the vehicle operator turn the ignition key to the "start' position for starting the vehicle, the negative side of

starter relay coil (21b) of (20) gets grounded through L terminal of the alternator and hence starter relay coil (20) get energized through the circuit which may be traced from the leads (28), (29), (30), (21a), (21b), blocking diode (34), L or WL terminal of the alternator, rotor field coil (9), regulator (35), ground potential (1) and to the negative terminal of the battery (2). The relay contact (22) will shift the pulley (7) and allow full battery potential to starter motor.

Upon engine start and vehicle running condition, the alternator (5) will be in run mode. At this condition, there exists a positive output potential at the L or WL terminal of the alternator (5) due to the action of diode trio (6, 17, 18). Now, when the vehicle operator tries to restart the vehicle, due to the equal positive potential act on the both ends of the starter relay coil (21) make the automatic de-energisation. Hence, the starter motor (3) automatically disconnected due to the deenergization of starter relay coil (21) upon engine "start" and when the engine (4) is running the condition.

The present invention also provides a method of controlling a starter relay (20) for an engine (4) that is equipped with starter motor (3), starter relay (20) and ignition switch. The starter recranking control method involves connecting the starter motor (3) with the internal combustion engine (4) through a starter relay (20) and an alternator (5), such that said starter relay coil (21) is grounded with a terminal of the alternator (5) through a blocking diode (34), and thereby developing an equal positive voltage at the both sides of relay coil (21) such that the starter relay (20) is de-energized and the starter motor (3) is disabled whenever the engine (4) is in running condition and the vehicle is re-started inadvertently.

The starter control system will deactivate the starter relay (20) upon engine "start" and if the operator of a vehicle attempts to re-start the vehicle when the engine is in the running conditions. The deactivation of the starter relay (20) will thereby prevent engagement of the starter pinion gear to the ring gear of the engine (6), potentially reducing wear on the starter and grinding of the pinion gear to the ring gear when engaging the gears at a high RPM.

The starting system control circuit for the automotive vehicles, according to the present invention disable the starter motor (3) upon engine "start" and after the engine (4) attains running condition. In accordance to the present invention, the energisation of electric starter relay (20) took place only when vehicle engine is in OFF condition. When the vehicle operator turn the ignition key to the "start' position for starting the vehicle, the starter relay coil (20) gets energized through the circuit which may be traced from the leads (28), (29), (30), (21a), (21b), blocking diode (34), L or WL terminal of the alternator, rotor field coil (9), regulator (35), ground potential 1 and to the negative terminal of the battery (2).

The starter recranking protection circuit according to the present invention eliminates the problems associated with the prior art and avoid recranking of engine whenever the vehicle is started inadvertently. The improved starter recranking protection circuit avoids energisation of the starter relay and prevents reengagement of starter motor while the engine is in the running mode. This safe operation starting and recranking protection of engine allows for improving the performance and life of the vehicle.
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.

We Claim:

1. A Starter recranking control system for an internal combustion engine, said system comprises,

a starter motor (3) for cranking an internal combustion engine (4), a starter relay (20) connecting said starter motor (3) with an alternator (5) such that said starter relay coil (21) is grounded with a terminal of the alternator (5) through a blocking diode (34) and said terminal gives out positive output potential in the alternator running condition;

wherein an equal positive voltage is developed at the both sides of relay coil (21) such that the starter relay (20) is deactivated and the starter motor (3) is disabled, whenever the engine (4) is in running condition and the engine is re-started inadvertently.

2. The starter recranking control system as claimed in claim 1, wherein, when the engine (4) and the alternator (5) are in running condition, a positive output potential is developed at said alternator terminal.

3. The starter recranking control system as claimed in claim 1, wherein the control system de-energize and deactivate said starter relay (20) upon starting the engine (4).

4. The starter recranking control system as claimed in claim 1, wherein a starter pinion gear from said starter motor (3) engages with a ring gear (6) of the engine (4) to start the engine.

5. The starter recranking control system as claimed in claim 1, wherein the deactivation of the starter relay (20) prevents engagement of the starter pinion gear to the ring gear (6) of the engine (4).

6. The starter recranking control system as claimed in claim 1, wherein said alternator (5) is driven by a pulley (7) of engine and a rotor (8) of the alternator (5).

7. The starter recranking control system as claimed in claim 1, wherein the internal combustion engine (4) is cranked by the starter motor (3) and the alternator (5) is driven by the cranked engine.

8. The starter recranking control system as claimed in claim 1, wherein the alternator (5) supplies power to a vehicle battery (2) and electrical system after driven by engine (4).

9. The starter recranking control system as claimed in claim 1, wherein the battery (2) is connected with the alternator (5) to store the energy developed from the alternator (5).

10. The starter recranking control system as claimed in claim 1, wherein energisation of said starter relay coil (21) is made through the positive polarity terminal of battery (2).

11. The starter recranking control system as claimed in claim 1, wherein an ignition switch is provided with the internal combustion engine (4) to control the energisation of the starter relay coil (21).

12. A method of controlling a starter recranking for an internal combustion engine, the method comprising the steps of,

connecting a starter motor (3) with the internal combustion engine (4) through a starter relay (20) and an alternator (5), such that said starter relay coil (21) is grounded with a terminal of the alternator (5) through a blocking diode (34),

developing an equal positive voltage at the both sides of relay coil (21) such that the starter relay (20) is de-energized and the starter motor (3) is disabled whenever the engine (4) is in running condition and the engine is re-started inadvertently.

13. The method of controlling a starter recranking as claimed in claim 15, wherein said alternator terminal gives out positive output potential in the alternator running condition.

14. The method of controlling a starter recranking as claimed in claim 15, wherein when the engine (4) and the alternator (5) are in running condition, a positive output potential is developed at said alternator terminal.

15.The method of controlling a starter recranking as claimed in claim 15, wherein the control system de-energize and deactivate the starter relay (20), whenever the operator of the vehicle attempts to re-start the engine (4) and the engine (4) is running condition.

16. The method of controlling a starter recranking as claimed in claim 15, wherein said alternator (5) is driven by a pulley (7) of engine (4) and a rotor (8) of the alternator (5).

17. The method of controlling a starter recranking as claimed in claim 15, wherein the internal combustion engine (4) is cranked by the starter motor (3) and the alternator (5) is driven by the cranked engine.

18 The starter recranking control system as claimed in claim 1, wherein the energisation of electric starter relay (20) is made only when the vehicle engine (4) is in OFF condition.

19. A motor vehicle having the starter recranking control system as claimed in any of the preceding claims.