FIELD OF THE INVENTION
The present invention proposes a system and method for detection of coolant temperature to avoid engine seizure.
BACKGROUND
In a water cooled engine, due to leakage in the system or poor maintenance, there is a possibility of engine running without coolant. The sensor output turns out to be invalid that the ‘limp home’ mode may not get activated during such undesired condition of no coolant. As a result, the engine would continue to run till seizure. To avoid the engine seizure, introducing a new algorithm in a transistor controlled ignition (TCI) unit that would necessarily check the coolant temperature becomes necessary.
SUMMARY OF THE INVENTION
Once the engine is started, a transistor controller ignition (TCI) unit (hereinafter “the TCI unit”) would monitor the coolant temperature rise for a specific duration of time. If the rate of change of the coolant temperature is not within the acceptable limit, the TCI algorithm will register coolant temperature plausibility error and then activates the ‘limp home’ mode. When there is no coolant in the system, the rate of change of temperature rise will be almost zero. The TCI unit registers plausibility error and then activates the ‘limp home’ mode. Thus, this method of TCI unit protects an engine from seizure.
Coolant reservoir is filled with coolant and is coupled with the engine. Coolant output from the engine is fed as input to a thermostat assembly. The thermal sensor is mounted on the thermostat assembly to sense the coolant temperature. The coolant output from the thermostat assembly is sent to a radiator assembly for reducing the temperature of the coolant by using a cooling fan. The coolant output from the radiator assembly is connected to the coolant reservoir. The coolant temperature input is sensed by the thermal sensor, and the same is given as input to the TCI unit. The TCI unit consists of a microcontroller to process input data from the thermal sensor. The output from the TCI unit is given to an ignition coil

assembly and the cooling fan. The Ignition coil assembly is connected to a spark plug which in turn is connected to the engine.
When the coolant temperature exceeds a first predetermined value, the TCI unit will switch ON the cooling fan. The TCI unit will switch OFF the cooling fan if the coolant temperature is lower than a second predetermined value. For the coolant temperature more than a third predetermined value, the TCI unit will switch OFF the output to the ignition coil. So that the engine will switch off immediately without any sparking. When the engine is started, the TCI unit will monitor the coolant temperature for a predetermined duration. When the rate of change of temperature rise is lower than a fourth predetermined value, the TCI unit switches OFF the output to the ignition coil. So the engine will not get a spark and will switch OFF immediately. When there is no coolant in the system, the rate of change of temperature rise will be almost zero. So, the TCI unit will switch off the engine immediately. If any leakage in the coolant circuit, the rate of change of temperature rise will be lower than the fourth predetermined value. Immediately, the TCI unit will switch OFF the output to the ignition coil. So the engine will not get the spark and will switch OFF immediately.
The method applies to all naturally aspirated Integrated Circuit (IC) engines with Liquid cooled for the following fuels, Gasoline, alternate fuels like LPG, CNG, and alcohol-based fuels, etc., and any type of transmission (for example Geared, AMT, CVT, etc.). The same function can be carried out by identifying the coolant level using the coolant level sensor but will not be as effective as the proposed invention, while more time is consumed during a state of a leak in the coolant circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates a block diagram of the required embodiments of the invention.
Figure 2 illustrates the process of detecting coolant temperature and eliminating the engine seizure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is made to Figure 1, which illustrates a block diagram of the required embodiments of the invention. Coolant is filled in coolant reservoir (101) and is coupled with the engine (102). Coolant output from the engine (102) is fed as input to a thermostat assembly (103). The thermal sensor (104) is mounted on the thermostat assembly (103) to sense the coolant temperature. The coolant output from the thermostat assembly (103) is sent to radiator assembly (108) to reduce the temperature of the coolant by using a cooling fan (109). The coolant output from the radiator assembly (108) is connected to the coolant reservoir (101). The coolant temperature input is sensed by the thermal sensor (104), and same is given as input to the TCI unit (105). The TCI unit (105) consists of a microcontroller to process input data from the thermal sensor (104). The output from the TCI unit (105) is given to an ignition coil assembly (106) and cooling fan (109). The ignition coil assembly (106) is connected with a spark plug (107) which in turn is connected to the engine (102).
As in Figure 2, when the coolant temperature exceeds the first predetermined value (114), the TCI unit (105) will switch ON the cooling fan (115). The TCI unit (105) will switch OFF the cooling fan (117) if the coolant temperature is lower than the second predetermined value (116). For the coolant temperature more than the third predetermined value (118), the TCI unit (105) will switch OFF the output to the ignition coil (119). So that the engine (102) will switch off immediately without any sparking.
When the engine (102) is started (110), the TCI unit (105) will monitor the coolant temperature (111) for a predetermined duration (112, 113). When the rate of change of temperature rise is lower than the fourth predetermined value , the TCI unit (105) switches OFF the output to the ignition coil (119). So the engine (102) will not get a spark and will switch OFF immediately. When there is no

coolant in the system, the rate of change of temperature rise will be almost zero. So, the TCI unit (105) will switch off the engine (102) immediately. If any leakage in the coolant circuit, the rate of change of temperature rise will be lower than the fourth predetermined value . Immediately the TCI unit (105) will switch OFF the output to the ignition coil (119). So the engine (102) will not get the spark and will switch OFF immediately.

WE CLAIM:
1. A system for coolant temperature detection to eradicate engine seizure
comprising: a coolant reservoir (101); an engine (102); a thermostat
assembly (103);a thermal sensor (104);a transistor controller ignition
(TCI) unit (105); an ignition coil assembly (106); a spark plug (107);
radiator assembly (108); and a cooling fan (109), wherein
the coolant reservoir (101) is filled with coolant and coupled with the engine (102); and wherein
the thermal sensor (104) is mounted on the thermostat assembly (103) to sense the coolant temperature;
the TCI unit (105) consists of a microcontroller to process input data from the thermal sensor (104); and further wherein
the ignition coil assembly (106) is connected to the spark plug (107) which in turn is connected with the engine (102).
2. The system for coolant temperature detection as claimed in claim 1, wherein coolant output from the engine (102) is fed as input to the thermostat assembly (103).
3. The system for coolant temperature detection as claimed in claim 1, wherein the coolant output from the thermostat assembly (103) is forwarded to the radiator assembly (108) to reduce the coolant temperature by using the cooling fan (109).
4. The system for coolant temperature detection as claimed in claim 1, wherein the coolant output from the radiator assembly (108) is connected to the coolant reservoir (101).
5. The system for coolant temperature detection as claimed in claim 1, wherein the coolant temperature input is sensed by the thermal sensor (104), and the same is given as input to the TCI unit (105) to process through its microcontroller.

6. The system for coolant temperature detection as claimed in claim 1,
wherein the output from the TCI unit (105) is given to the ignition coil
assembly 106 and the cooling fan 109 is operated as follow,
if the coolant temperature exceeds a first predetermined value (114), the TCI unit (105) will switch ON the cooling fan (119); and
if the coolant temperature is lower than a second predetermined value (116), the TCI unit (105) will switch OFF the cooling fan (119).
7. The system for coolant temperature detection as claimed in claim 1, wherein when there is no coolant the rate of change of temperature rise will be almost zero and the TCI unit (105) will switch off the engine (102) immediately.
8. The system for coolant temperature detection as claimed in claim 1, wherein if there is a leakage in the coolant circuit the rate of change of temperature rise will be lower than the fourth predetermined value and immediately the TCI unit (105) switches OFF the output to the ignition coil (119) thus avoids sparking of the engine (102).
9. A method of detecting coolant temperature to eradicate engine seizure having, a coolant reservoir (101); an engine (102); a thermostat assembly (103); a thermal sensor (104); a transistor controller ignition (TCI) unit (105); an ignition coil assembly (106); a spark plug (107); radiator assembly (108);and a cooling fan (109), comprising the steps of:
starting (110) the engine (102) by switching ON the ignition key (110);
monitoring the coolant temperature (111) for a predetermined duration (112, 113) by the TCI unit (105);
switching ON the cooling fan (115) by the TCI unit (105) if the coolant temperature exceeds a first predetermined value (114);

switching OFF the cooling fan (117) by the TCI unit (105) if the coolant temperature is lower than a second predetermined value (116);
switching OFF the output to the ignition coil (119) by the TCI unit (105) when the coolant temperature exceeds a third predetermined value (118);
switching OFF the output to the ignition coil (119) thus, preventing the engine (102) from sparking by switching OFF immediately if the rate of change of temperature rise is lower than a fourth predetermined value (113) due to a leakage in the coolant circuit; and
switching OFF the engine (102) immediately by the TCI unit (105), if there is no coolant resulting in the rate of change of temperature rise to be almost zero.
10. The method of detecting coolant temperature as claimed in claim 9, wherein said method applies to all naturally aspirated Integrated Circuit (IC) engines with liquid cooled for the following fuels, Gasoline, alternate fuels, including LPG, CNG, and alcohol-based fuels, and any type of transmission.