Field of invention

The present invention relates generally to a cooling fan control system used in two wheelers, and more particularly to a fan control system used for internal combustion engine cooling.

Background of the invention

Use of a cooling fan in two wheelers is a well known and necessary practice. This fan is driven by an electrical circuit and can be called as electrical load for the specific circuit. In the existing practice the Electrical loads are driven by additional relay contacts where the relay coil activation is made by a control signal - 'the output of Micro controller unit' used in the circuit. These micro controller units have the various inputs from vehicle parameters, which are sensed by sensors & finally fed to the Micro controller. As the microcontroller unit is unable to control the heavy loads like Fan directly thus an additional relay is required so that the required amount of current can be achieved without harming the microcontroller and the complete circuit.

Provision of this relay includes higher manufacturing cost, more space requirement; higher maintenance cost as the relays kept separately are more likely to get damaged because of mechanical wear and tear.

Summary of the invention

The present invention relates to a control system used for cooling assembly (herein after fan) in two wheelers. The said control system is based upon a transistor controlled ignition (TCI) unit wherein the fan control unit is interlinked with the micro controller and the external relay which was used to hold the high current has been removed in order to reduce interconnection of the wiring harness and to develop a easier manufacturing process. Mainly the said transistor controlled ignition (TCI) comprises a analog to digital convertor which is connected to the comparator used for comparing the temperature level provided by the thermal sensor, a power regulation circuit, plurality of signal conditioning units, a processing unit, a load control unit which can carry required level of current, a signal diagnostic unit and an ignition control unit wherein the transistor controlled ignition (TCI) unit provides a switching control signal to the cooling fan.

These and other features, aspects, and advantages of the present subject matter will become better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Brief description of the drawings

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus, are not limited of the present invention and wherein:

Figure 1 shows the block diagram of the cooling fan control system. Figure 2 shows the block diagram of the transistor controlled ignition (TCI) unit.

Detailed description of the invention

The embodiments disclosed below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. The application of this invention is extended to all kind vehicles.

Referring to Figure 1, block diagram of control system for cooling fan used in a two wheeler is shown. The transistor controlled ignition (TCI) (3) unit is receiving the signal from thermal sensor (1) which is receiving the power signal input from TCI unit (3). Based upon the input received from crank sensor (8), throttle positioning system (TPS) (4) and thermal sensor (1) TCI unit (3) gets activated and sends the control command to cooling assembly (herein after FAN) (2) , Malfunction indicator (MFI) (9), Engine warm up indicator (EWI) (12) and Inducting ignition (IDI) coil (5). Based upon the signal generated respective function takes place such as the state of the Fan i.e. ON/OFF changes, MFI indicates in case of any malfunctioning in the vehicle whereas the spark generation is controlled by the IDI coil (5) output.

Further referring to Figure 2, main aspect of the invention i.e. the TCI unit (3) and the working is explained. The Transistor controlled ignition (TCI) unit (3) is a microcontroller based controlled system where the internal control system (18) is an additional and novel part of standard TCI unit (3). The TCI unit (3) will have an input supply regulation (13) & signal conditioning circuit (15), ADC converter (12) to handle the analog sensor inputs. The corresponding voltage & logic signals are received by the micro controller (16), which will provide the desired out puts for the predetermined functions such as ignition output (20), fan control (17), diagnostic control (19) and output curve regulation (18).

The output of the thermal sensor (1) is in a variable resistance form, which will get converted into voltage in TCI unit. Depending on the temperature of the Coolant the output resistance will vary, this variable resistance is being used to control the state of cooling fan (2) through micro controller (16). The said thermal sensor (1) output in an analog output fed to ADC (12) & comparator circuit (14) of TCI. Based on the comparator-predefined value, which is pre-stored in the memory, the corresponding digital output will be given to Micro controller (16). The Micro controller (16) will provide the output to Fan control circuit (18) to control the function of Fan (2).

The said fan control unit (17) will have transistor to operate in open state and a closed state. The cooling fan is turned into 'ON' condition when the transistor is in a closed state. The status of the cooling fan can be changed from the 'ON' condition to an 'OFF' condition by making the transistor into the open state.

Based on output of the thermal sensor (1) the temperature of the Coolant is measured and if it exceeds the predetermined temperature then the output voltage corresponding to resistance of the thermal sensor (1) also exceeds a predetermined voltage.

This increase in the output voltage enables the micro controller (16) to change the state of the transistor of the Fan control unit (17) in to the closed state by applying the voltage to the base emitter region of the transistor. The close state of the said transistor further results in the 'ON' condition of the fan control unit (17) which finally turns-on the cooling fan (2).

When the temperature of the Coolant is below the predetermined temperature then the output voltage of the thermal sensor (1) will be lower than the predetermined voltage which enables the micro controller (16) to change the status of the transistor of the fan control unit (17) into the open state. Due to the open state of the transistor, cooling fan unit remains in 'OFF' condition and hence the cooling fan (2) remains off.

The above explained preferred embodiments are exemplary of the invention of the present application, which is described solely by the claims appended below. It should be understood that modifications of the preferred embodiments might be made as would occur to one of skill in the art.

Claims:

What is claimed is:

1) A cooling assembly control system for a vehicle comprising:

a transistor controlled ignition unit configured to receive a plurality of input and to send a plurality of output;

wherein, the transistor controlled ignition unit comprises a micro controller configured to receive the plurality of input through a signal conditioning unit and a comparator unit.

wherein, the plurality of input comprises a plurality of sensor configured to send analog signal to the transistor controlled ignition unit;

wherein, the plurality of output comprises a plurality of control command transmitted to a plurality of command receiver configured for a predefined operation.

2) A cooling assembly control system for a vehicle, as claimed in claim 1, wherein, the plurality of sensor comprising a crank sensor.

3) A cooling assembly control system for a vehicle, as claimed in claim 1, wherein, the plurality of sensor comprising a thermal sensor.

4) A cooling assembly control system for a vehicle, as claimed in claim 1, wherein, the plurality of sensor comprising a throttle positioning sensor.

5) A cooling assembly control system for a vehicle, as claimed in claim 1, wherein, the predefined operation includes a cooling operation, a engine performance diagnosis, an ignition control operation.