[0001] The following specification particularly describes the invention and the manner in
which it is to be performed.
FIELD OF INVENTION
[0002] This invention relates to protection system used in vehicles and more particularly
this relates to engine protection system that monitors engine operating conditions
and disables the engine in the event of non-functioning of cooling system or short
fall of cooling media.
BACKGROUND OF INVENTION
[0003] During combustion of the engine and because of friction between various moving parts
of the engine substantial amount of heat is generated which needs to be dissipated
in order to maintain safe temperatures for engine and various systems to work properly.
[0004] An automobile may be either air-cooled or coolant cooled. In case of an air cooled
engine, the engine is mounted such that air passes through it when the automobile
is in motion. The passing over of air over the engine block ensures it's cooling.
However this type of cooling is effective only for smaller engines like those used
in scooters or motorbikes. Bigger engines generally are coolant cooled. In this system
coolant is circulated through a coolant jacket in the engine block with an aid of
a pump. The coolant while it passes through the engine block carries with it the heat
of combustion, this heat is then dissipated through a radiator placed in front of
the vehicle.
[0005] The burning fuel inside the engine cylinder raises the temperature of the cylinder,
piston and valve. If some of this heat is not removed, these components would be damaged
severely. Simultaneously sufficient care must be taken that the engine must also not
be over cooled, therefore an ideal equilibrium temp. of 75-95°C should be maintained
by the cooling system.
[0006] If the engine is over cooled some of the heat which could be used to expand the gases
will be lost. The fuel will not vaporize properly and some of the gases produced by
combustion will condense on the cylinder walls. This leads to dilution of the oil
in the sump and the addition of harmful corrosive acids. Removal of the oil film from
the cylinder wall by the unvaporized fuel leads to increased cylinder bore wear inadequate
lubrication of the engine, due to the oil not being warm enough to flow freely, results
in greater frictional losses. In general the economy and life of the engine would
be reduced.
[0007] At the same time under cooling can cause engine seizure or at least shortened valve
life and possible distortion of the cylinder block, head or gasket a hot-spot inside
the combustion chamber may be sufficient to cause pre-ignition to ignite the fuel
before the spark plug does, this causing loss of power and possible damage to the
engine components. Coolant in the cooling system may boil and evaporate, and if the
oil film burns away additional friction and wear will occur between cylinder and piston.
[0008] In automobiles with an internal combustion engine, a radiator is connected to channels
running through the engine and cylinder head, through which a liquid is pumped. This
liquid is typically a mixture of coolant with Ethylene glycol as antifreezer. The
fluid moves in a closed system from the radiator to the engine, where it conducts
heat away from the engine parts and carries the heat primarily to the radiator. The
radiator is typically mounted behind the vehicle's grille, with cold air driven through
the radiator to cool the radiator, the fluid inside, and therefore the engine. Between
the engine and the radiator lies the thermostat, a temperature operated valve. It
remains closed, restricting coolant flow, until the engine reaches the thermostat's
activation temperature. This arrangement allows the engine temperature to be maintained
in the ideal operating range.
[0009] Most of the motor vehicles use circulating coolant to cool the engine and there are
different methods of cooling:
- a) Thermo-siphon system- The thermo siphon system depends upon the natural circulation of coolant when heated
at one point. In this circulation, coolant flows from radiator bottom tank to engine
coolant jackets and from engine coolant jackets to radiator top coolant tank and from
radiator top tank to bottom tank. This coolant movement is caused by convection currents.
Coolant surrounds each of the cylinders, valves and plug pockets. The coolant in these
areas gets hot and expands. Cooled coolant from the bottom tank of the radiator moves
into position round the regions vacated by the hot rising coolant. The hot coolant
reaches the header tank and passes down to the radiator tubes, where it is cooled
by air traveling through the radiator grill. On reaching the bottom tank, its temperature
decreases and it enters in the cylinder block and head again.
- b) Use of impeller- Under heavy loads or in hot climates the engine gets so hot that the coolant may
not circulate fast enough. A pump is needed especially in over head valve engine which
have small coolant passages. This addition allows a smaller radiator to be used.
[0010] Since the coolant is constantly under pressure, it can be directed to engine at high
temperature locations, such as valve seats and plug bosses.
[0011] In both above systems it is essential that a proper level of coolant is maintained,
well above the pipe bringing coolant from the engine, otherwise circulation will stop.
Also connecting pipes must be large enough to permit the coolant to flow freely.
[0012] At the same time the total coolant cooling system which includes radiator, coolant
pump, coolant jacket and all connecting pipes and hoses should be perfectly enclosed.
There should not be any leakage at any point or any part of the entire coolant cooling
system. And if it happens the coolant in the cooling system may drain. Due to less
amount of coolant in the system, the temperature of the engine will keep on increasing
and ultimately which will result is over heating of engine.
OBJECTS OF THIS INVENTION
[0013] The main object of this invention is to provide an engine protection system that
can disable the engine in the event of shortage or leakage of cooling media to prevent
engine seizure.
[0014] Another object of this invention is to provide an engine protection system which
is simple and cost effective.
BRIEF DESCRIPTION OF INVENTION
[0015] Engine protection system in accordance with this invention basically comprises at
least one float sensor, auxiliary coolant tank, a relay, Fuel Injection Pump (FIP)
solenoid switch and coolant level warning indicator wherein said float sensor basically
comprises a sensor stem, a magnetic float freely mounted on said stem and a magnetic
reed valve provided at free end of the said stem and is provided on an auxiliary coolant
tank to sense the level of coolant inside the said tank. Said auxiliary coolant tank
is provided to maintain sufficient coolant level inside the radiator. Said relay is
having two coil points, one pole point, one normally open and one normally close point.
Wherein said one coil point is connected to first point of float sensor and another
coil point is connected to coolant level warning indicator through an earthling. Said
pole point is connected to power supply and second point of float sensor, said normally
open point is connected to coolant level warning indicator and normally close point
is connected to FIP solenoid switch. Said coolant level warning indicator is provided
at instrument cluster.
[0016] When coolant level inside the said auxiliary coolant tank drops beyond the specified
limit then float unit of said float sensor moves down and completes the electrical
circuit, because of which the FIP solenoid switch will cut off the diesel supply to
the engine. After this even though the engine gets cranked but it will not start unless
the level of coolant in a said tank resumes to the normal level.
DETAILED DESCRIPTION OF INVENTION
[0017] 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,
Fig. 1 - Shows an engine protection system in accordance with this invention;
Fig. 2 - Shows a magnetic float sensor used in engine protection system;
Fig. 3 - Shows a relay circuit diagram used in engine protection system.
[0018] Referring to Figures 1 to 3, Engine protection system according to one embodiment
of this invention basically comprises at least one float sensor (1), auxiliary coolant
tank (2), a relay (3), Fuel Injection Pump (FIP) solenoid switch (4) in case of diesel
engine and coolant level warning indicator (5) wherein said float sensor basically
comprises a sensor stem (11), a magnetic float (10) freely mounted on said stem and
a magnetic reed valve (12) provided at free end of the said stem and is provided on
cap (13) of an auxiliary coolant tank (2) to sense the level of coolant inside the
said tank. Said auxiliary coolant tank is provided to maintain sufficient coolant
level inside the radiator (not shown). Said relay is having two coil points (A, E),
one pole point (B), one normally open point (C) and one normally close point (D).
Wherein said coil point (A) is connected to first point (6) of float sensor (1) and
another coil point (E) is connected to coolant level warning indicator (5) through
an earthing point (7). Said pole point (B) is connected to power supply (8) and second
point (9) of float sensor (1), said normally open point (C) is connected to coolant
level warning indicator (5) and normally close point (D) is connected to FIP solenoid
switch (4). Said coolant level warning indicator is provided at instrument cluster
(not shown).
[0019] When coolant level inside the said auxiliary coolant tank (2) drops beyond the specified
normal limit then magnetic float (10) of said float sensor (1) moves down and comes
into contact with reed valve (12) and completes the circuit, because of which the
FIP solenoid switch (4) cuts power supply to the FIP and hence there will not be any
fuel supply to the engine. After this even though the engine gets cranked but it will
not start unless the level of coolant in a said tank resumes to the normal level.
[0020] To avoid above problem, as soon as coolant level in auxiliary coolant tank goes down
it would be indicated to driver on instrument cluster through the proposed circuitry.
[0021] Engine protection system according to another embodiment of this invention basically
comprises at least one float sensor (1), auxiliary coolant tank (2), a relay (3),
Engine control unit (4) in case of petrol engine and coolant level warning indicator
(5) wherein said float sensor basically comprises a sensor stem (11), a magnetic float
(10) freely mounted on said stem and a magnetic reed valve (12) provided at free end
of the said stem and is provided on cap (13) of an auxiliary coolant tank (2) to sense
the level of coolant inside the said tank. Said auxiliary coolant tank is provided
to maintain sufficient coolant level inside the radiator (not shown). Said relay is
having two coil points (A, E), one pole point (B), one normally open point (C) and
one normally close point (D). Wherein said coil point (A) is connected to first point
(6) of float sensor (1) and another coil point (E) is connected to coolant level warning
indicator (5) through an earthing point (7). Said pole point (B) is connected to power
supply (8) and second point (9) of float sensor (1), said normally open point (C)
is connected to coolant level warning indicator (5) and normally close point (D) is
connected to said Engine control unit (4). Said coolant level warning indicator is
provided at instrument cluster (not shown).
[0022] When coolant level inside the said auxiliary coolant tank (2) drops beyond the specified
normal limit then magnetic float (10) of said float sensor (1) moves down and comes
into contact with reed valve (12) and completes the circuit, because of which the
Engine control unit (4) cuts power supply to the engine. After this even though the
engine gets cranked but it will not start unless the level of coolant in a said tank
resumes to the normal level. To avoid above problem, as soon as coolant level in auxiliary
coolant tank goes down it would be indicated to driver on instrument cluster through
the proposed circuitry.
[0023] 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.
1. Engine protection system comprises at least one float sensor, auxiliary coolant tank,
a relay, Fuel Injection Pump (FIP) solenoid switch and coolant level warning indicator
wherein said float sensor is provided on an auxiliary coolant tank to sense the level
of coolant inside the said tank, said relay is having two coil points, one pole point,
one normally open point and one normally close point, said one coil point is connected
to first point of float sensor and another coil point is connected to coolant level
warning indicator through an earthing, said pole point is connected to power supply
and second point of float sensor, said normally open point is connected to coolant
level warning indicator and normally close point is connected to FIP solenoid switch
and said coolant level warning indicator is provided at instrument cluster.
2. Engine protection system comprises at least one float sensor, auxiliary coolant tank,
a relay, engine control unit (ECU) and coolant level warning indicator wherein said
float sensor is provided on an auxiliary coolant tank to sense the level of coolant
inside the said tank, said relay is having two coil points, one pole point, one normally
open point and one normally close point, said one coil point is connected to first
point of float sensor and another coil point is connected to coolant level warning
indicator through an earthing, said pole point is connected to power supply and second
point of float sensor, said normally open point is connected to coolant level warning
indicator and normally close point is connected to engine control unit (ECU) and said
coolant level warning indicator is provided at instrument cluster.
3. Engine protection system as claimed in claims 1 and 2, wherein said float sensor basically
comprises a sensor stem, a magnetic float freely mounted on said stem and a magnetic
reed valve provided at free end of the said stem.
4. Engine protection system as claimed in claims 1 to 3, wherein said float sensor is
provided in a cap of said auxiliary coolant tank.
5. Engine protection system as claimed in claims 1 to 4, wherein said auxiliary coolant
tank is provided over the radiator to maintain sufficient coolant level inside the
radiator.
6. Engine protection system as claimed in claims 1 to 5, wherein said relay is provided
inside the instrument cluster.
7. Engine protection system as claimed in claims 1 to 6, wherein said coolant is water
mixed with antifreezer.
8. Engine protection system as claimed in claims 1 to 7, wherein said coolant level warning
indicator is a cluster bulb.
9. Vehicle provided with the engine protection system as claimed in claims 1 to 8.
10. Engine protection system substantially as herein described with reference to accompanying
drawings.