FIELD OF INVENTION
[0001] The present invention relates to an internal combustion engine cooling
mechanism and more particularly to a radiator system in a three-wheeled vehicle.
BACKGROUND OF INVENTION
[0002] An automobile engine performs combustion of fuel inside the cylinder
thus thereby powering the transmission system connected to the engine along with production of a large amount of heat energy. This heat energy is mainly concentrated near to the cylinder block and cylinder head of the internal combustion engine. It is necessary to maintain the engine temperature at an optimum level to improve the combustion process. In addition, it is necessary to keep the temperature levels of surrounding of the engine cabin/compartment under control in order to avoid hot air recirculation.
[0003] In general, automobiles with front mounted liquid cooled engine have their
radiator assembly placed at front in the direction of movement of the vehicle. This helps in improving the cooling efficiency of the radiator as the fresh air from atmosphere comes in direct contact with the radiator. In addition, necessary care is taken to vent out the heated air from re-circulating near the engine. Wherein in the case of a rear mounted engine there is a challenge in mounting the radiator assembly, as the vehicle movement direction is not helpful for inducting fresh air and venting out the- hot re-circulating air from the engine cabin.

[0004] The engine cabin may affect the engine's cooling efficiency by reducing
the amount of fresh and lower temperature air entering inside the engine cabin. Hence, removal of hot air from the cabin space is very important for comfort, at the same time" there is a risk of hot air being recirculated inside the engine cabin if not properly ventilated. Since for a motor vehicle with rear-mounted engine, fresh air cannot reach the hot areas of the engine beyond a certain limit, the engine and its components need an extra mechanism for cooling for maintaining the engine temperature at optimum levels by expelling the hot air inside the engine cabin space into the outer atmosphere.
SUMMARY OF THE INVENTION
[0005] - Hence, to overcome the above problems associated with the current
design, the present invention discloses a novel approach of placing the radiator, fan assembly and the radiator ducting in order to improve the efficiency of the cooling system by increasing the chance of inducting fresh air coming in contact with the radiator and at the same time expelling maximum possible hot air out of the engine cabin space.
[0006] A ducting system is introduced in the radiator assembly in order to expel
the hot air inside the engine cabin to the outer atmosphere, which can result in improving the overall cooling efficiency of the engine. In the new design the direction of the radiator, fan assembly is flipped and placed in reverse direction of vehicle movement. Functionally this arrangement is advantageous as it helps to pull more fresh air from the atmosphere through the vents of tail door of the vehicle and in-turn helps in improving the radiator efficiency substantially. Moreover, the ducting system on the radiator

assembly directly expels the hot air coming out of the radiator into the outer atmosphere. This avoids the hot air re-circulation inside the engine cabin which otherwise affects the cooling system efficiency.
[0007] The ducting system for hot air outlet plays an important role in expelling
the hot air and it is proposed to vent out the hot air into the outer atmosphere through side panels of the vehicle in the left side or right side depending upon the placement of the radiator and orientation of the engine. The radiator assembly in the new proposed design is placed in the left side of the vehicle when viewed from the rear. Moreover, the placement of radiator depends upon the engine orientation. Hence, the radiator duct can .. be placed on the right side as well. Yet in another embodiment, the hot air is expelled downwards through the radiator ducts instead of using the side panels of the motor vehicle. Again, while using the downward exit of hot air, the radiator can be on either of the left or right side of the vehicle as seen from the rear of the vehicle depending upon the placement of the radiator and orientation of the engine.
[0008] In another embodiment, a more efficient tail door is disclosed which will
enhance the induction of fresh cooler air inside the engine cabin space and will increase the efficiency of the whole radiator cooling system as disclosed in the present invention. The vents made in the tail door are made according to the location of the radiator for efficient induction of fresh air.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 illustrates a typical three-wheeler.

Figure 2 illustrates engine mounting in a typical three-wheeler.
Figure 3 illustrates the top view of engine mounting in a typical three-wheeler according to the first embodiment of the invention.
Figure 4 illustrates a cooling system for the three-wheeler according to the first embodiment of the invention.
Figure 5 illustrates the rear view of the cooling system for the three-wheeler according to the first embodiment of the invention.
Figure 6 illustrates the top view of engine mounting in a typical three-wheeler according
to'the second embodiment of the invention. . .
Figure 7 illustrates a cooling system for the three-wheeler according to the second embodiment of the invention.
Figure 8 illustrates the rear view of the cooling system for the three-wheeler according to the second embodiment of the invention.
Figure 9 illustrates a cooling system for the three-wheeler according to the third embodiment of the invention.
Figure 10 illustrates the left side view of the cooling system for the three-wheeler according to the third embodiment of the invention.
Figure 11 illustrates the rear view of the cooling system for the three-wheeler according' to the third embodiment of the invention.
Figure 12 illustrates a cooling system, for the three-wheeler according to the fourth embodiment of the invention.

Figure 13 illustrates the right side view of the cooling system for the three-wheeler according to the fourth embodiment of the invention.
Figure 14 illustrates the rear view of the cooling system for the three-wheeler according to the fourth embodiment of the invention.
Figure 15 illustrates a typical tail door mesh arrangement for efficient induction of outside air for the radiators for various embodiments of the invention.
Table-1 Shows comparative results by using venting mechanism through tail door mesh.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The improved liquid-cooling system of engine according to the present
invention consists of a coolant pump, a system of water/coolant jackets and passages in the cylinder head and block (through which the coolant circulates to remove the heat from the engine), radiator, fan, radiator duct and thermostat assembly and finally the essential piping's connection between the engine and radiator assembly. Engine cooling is accomplished by keeping the coolant circulating and in contact with the hot metal surfaces of the engine to be cooled. The description of the invented liquid-cooled system can be explained as follows.
[00010] The coolant pump driven by the engine through a proper mechanical
connection draws the coolant from the bottom of the radiator and forces the coolant through the water jackets and passages in the cylinder head and cylinder block of the engine, and eventually hot coolant is ejected into the upper radiator tank. The coolant

then passes through a set of tubes to the bottom of the radiator from which the cooling cycle begins. The radiator is situated in front of a fan that is driven by an electric motor.
[00011] In present invention, placing of this fan in the reverse direction of the
. vehicle movement direction pulls more fresh air from the outer atmosphere and inducts it to the radiator tubes of the radiator. The inducted fresh.air getting in contact with these radiator tubes takes away heat from the engine cabin. Hence, after removing the heat from the coolant passing through the radiator tubes with increased efficiency when compared with conventional system of cooling wherein the hot air circulating inside the engine cabin has to be used for cooling the coolant passing through the radiator tubes.
[00012] Moreover, the hot air passing out post the radiator is directly vented out to
the outer atmosphere through a proposed radiator duct without allowing it to re-circulate within the engine cabin. The fan ensures airflow through the radiator even at times when there is slower vehicle motion. The thermostat controls the operation of fan based on the temperature of the coolant. The various embodiments of the current invention are described in the following description. In all the figures, vehicle left and right is the sides of the vehicle as seen from the vehicle rear to vehicle front.
[00013] Figure lshows a typical three-wheeler 10 with front wheel 1, rear wheel 2,
driver seat 3, vehicle chassis 4, wheel arch 5, vehicle rear cabin space 6, cabin space cover 7, passenger seat 8 and engine 9. The liquid cooling system as disclosed in the current invention is mounted and installed in the said vehicle rear cabin space 6. Different embodiments of the current invention involving different mounting and installing have

been discussed under different embodiments. The main aim of the current invention is to inhibit the heating of the vehicle rear cabin space 6 by expelling the heat produced by the engine 9 inside the vehicle rear cabin space 6 to the outer atmosphere. This has been accomplished by installing a system comprising of the radiator, fan and radiator duct. Various installing methods of the radiator, fan and radiator duct provide different advantages, which has been disclosed under various embodiments of the current invention.
[00014] Figure 2illustrates engine mounting in a typical three-wheeler. The engine
is mounted in the rear cabin space.6 and inbetween the two-rear wheel arch 5. The engine 9 consists of cylinder head 9A, cylinder block 9B and the engine transmission 9C. For easy illustration and clarity of essential elements of different embodiments to be visible, the engine 9 has been shown only with the cylinder head 9A and cylinder block 9B. Engine transmission 9C has not been shown in the other figures for retaining clarity of essential elements in the illustrated figures.
[00015] Figure 3 illustrates the top view of engine mounting in the proposed three-wheeler. Cylinder head 9A, Cylinder block 9B, engine transmission 9C in the vehicle rear cabin space are visible. Thermostat assembly flange 31 is connected to the cylinder block for providing hose connection between the radiator and the engine. The orientation of engine 9 alters the positioning of the thermostat assembly flange 31, which will decide the location of mounting of the radiator, fan shroud, fan and the radiator duct for proper cooling mechanism.

[00016] Figure 4 shows the liquid cooling system for the three wheeler according
to the first embodiment of the invention. The vehicle rear cabin space 6 (Figure 1) has been divided into two portions namely left portion cabin space left 6L and cabin space right 6R. Engine cylinder head 9A and cylinder block 9B are also illustrated. Figure 4 also shows coolant reservoir 41, radiator duct 42 according to the first embodiment of the invention, radiator 43 according to the first embodiment of the invention, left side panel 44, fan motor 45 and fan shroud 46.The radiator 43 is placed exposed to the rear outer atmosphere. The fan shroud 46 is mounted on the radiator cover and fan motor is mounted on the fan shroud. Fan shroud covers the fan blades. The whole of the fan shroud along with the fan motor is covered by an envolute42 which starts from the fan shroud 46 and ends in the left side panel 44 of the vehicle 10. The enveloping of the fan shroud 46 by the envolute or the radiator duct 42 gathers all the heated air out from the cabin space to the outer atmosphere.
[00017] Figure 5 shows the rear wheel of the current invention, according to the
first embodiment of the invention. Figure 5 also shows two wheels archs5L and 5R under which resides the two rear wheels 2, cabin space left 6L, engine cylinder head 9A, engine cylinder block 9B, radiator duct 42 according to the first embodiment of the current invention, radiator 43, left side panel 44, tail door 51, thermostat to radiator cooling hose 52, pump to cylinder block cooling hose 53, coolant pump 54, radiator top 55 and radiator bottom 56. The coolant flow is from the coolant pump 54 to the cylinder block 9B and then the coolant exits the engine from the cylinder head 9Aand passes through the thermostat to the radiator cooling hose and then back to the radiator top. The coolant from

radiator top passes through the radiator ducts and exits the said radiator from the radiator bottom during which the heat is dissipated into the outer atmosphere through the fan and radiator duct assembly of the cooling system.
[00018] Figure 6 shows engine orientation according to the second embodiment of
the invention. Since the thermostat assembly flange61 is on the right side, the radiator along with the radiator duct, fan and fan shroud is mounted on the vehicle rear cabin right side space 6R of the vehicle. Figure 6 also shows the engine 9 with the engine cylinder head 9A and engine cylinder block 9B.
[00019] Figure 7 shows the top view of the cooling system according to the second
embodiment of the invention. In this second embodiment, Figure 7 shows the engine cylinder head 9A, cylinder block 9B, fan motor 75, radiator 63, coolant reservoir 41, radiator duct 62, right side panel 74 all housed in the vehicle cabin rear right side space 6R. In this second embodiment of the current invention, it is proposed to exit the hot air coming from the radiator duct through the right side panel of the vehicle.
[00020] Figure 8 shows the rear view of the second embodiment. Figure 8shows
the vehicle rear cabin right side space 6R, engine cylinder head 9A, engine cylinder block 9B, radiator duct 62, radiator 63 and right side panel 74. Figure 9 shows the top view of the cooling system according to the third embodiment of the invention. The location of the radiator, fan shroud and fan is same as in the first embodiment. The only difference being the type and exit point of the envolute 91, which carries hot air coming through the fan to the outer atmosphere. Figure 9 shows the radiator duct 91, radiator 93, fan motor

95, cylinder block to radiator top cooling hose 92, thermostat assembly flange 61 and the engine cylinder head 9A and the engine cylinder block 9B. As seen from the top it is clear that the hot air through the radiator duct is not exited through the side panels. It would be more clearly visible in the side view of this embodiment that in fact the hot air is exiting from the cabin rear space 6R to the outer atmosphere towards the ground.
[00021] Figure 10 shows side view of the vehicle rear according to the third
embodiment of the invention. Figure 10 shows the rear wheel 2, wheel arch left 5L, vehicle rear cabin space left 6L, radiator duct 93; fan motor 104, fan blades 105. The dotted lines for the rear wheel 2 are only for illustration purpose. As seen from the left side, the radiator duct 91 is behind the wheel 2 and the wheel arch left 5L. As it can be clearly visualized from the Figure 10, the hot air is sucked in the cabin rear space by fan blades 105 through the radiator 93 and expelled towards the ground.
[00022] Figure llillustrates the rear view of the cooling system according to the
third embodiment of the invention. Figure llshows the wheel arch left 5L, wheel arch right 5R, cabin space left 6L, engine cylinder head 9A, engine cylinder block 9B, radiator duct 91 and radiator 93 according to the third embodiment of the invention. As seen in the rear view, the radiator duct in the transverse direction of the vehicle width, lies next to the wheel arch left side 5L. In this embodiment as well, the radiator is installed to face towards the rear outer atmosphere, so that the fan to provide more efficient cooling can suck fresh, cooler air.

[00023] Figure 12 shows the cooling system according to the fourth embodiment
of the current invention. Figure 12 is the top view of the radiator and cooling system installation and mounting. The cooling system comprises of the engine cylinder head 9A, engine cylinder block 9B, fan motor 124, radiatorl23 and radiator duct 121 all located in the rear cabin space right side 6R of the vehicle 10.
[00024] Figure 13 shows the right side view of the cooling system according to the
fourth embodiment of the current invention. Figure 13 shows the rear wheel 2, wheel arch right 5R, vehicle rear cabin space right 6R, radiator duct 121 and the radiator 123. As it is clearly visible in the right side view of the current embodiment, the hot. air is being. . expelled through the radiator duct 121 towards the ground beneath the vehicle chassis.
[00025] Figure 14 illustrates the rear view of the vehicle according to the fourth
embodiment of the current invention. Figure 14shows the wheel arch left 5L, wheel arch right 5R, engine cylinder head 9A, engine cylinder block 9B, radiator duct 121, radiator 123 and thermostat to radiator coolant hose 141. It is clearly visible in the Figure 14 that the radiator duct 121, radiator 123 and thermostat to radiator coolant hose 141 are located in the right side of the vehicle rear cabin space 6R.
[00026] Figure 15 shows a typical tail door to be used for all the embodiments as
disclosed in the current invention. As per the requirement of the current invention, a more efficient tail door is required which will enhance the induction of fresh and cooler air inside the engine cabin space and will increase the efficiency of the whole radiator cooling system as disclosed in the present invention. The vents made in the tail door are

made according to the location of the radiator for efficient induction of fresh air. For the said purpose, Figure 15 discloses a tail door 151 with mesh type venting 154, which covers both the right side and the left side locations of the radiators. As clearly illustrated in the Figure 15, radiator (43, 93, 63 and 123) is covered using the tail door mesh 154.
[00027] Table-1 shows the comparison of experimental values for the cabin space
rear temperatures with and without the radiator duct at both high speed (60 KmPH) and low speed (26KmPH). The table compares the temperature of rear cabin space of prior art to that of the proposed invention. The ambient air has been maintained at a temperature . ..of 41°C. Table-I shows the temperature, measurement, values for.a .system wherein, the radiator and radiator duct are placed in the cabin rear space left side. The vehicle high-speed value 60KmPH and low speed value 26KmPH are average values taken based on riding pattern of a normal three-wheeler vehicle.
[00028] The temperature at rear cabin space left (6L) is measured by the aid of
temperature sensor mounted on left side panel 44 and protruded into rear cabin space left (6L). From the Table-I , it can be clearly seen that there is a significant amount of reduction in temperature of rear cabin space at vehicle lower speed of around 26KmPH. Also, for higher speed as of at 60KmPH, the placement of radiator and radiator duct brings reduction in temperature of rear cabin space by a significant amount.
[00029] The proposed radiator mounting and the radiator duct layout is. for
efficiently expelling the hot air from the cabin rear space of a three-wheeler. Temperature measurements were carried out with the features in a three-wheeler as per the claim and

then the corresponding temperature readings were compared with that of a three-wheeler without the claimed features. The result in Table-I shows considerable reduction in temperature in the rear cabin space. The proposed invention of the radiator duct layout in-cooling system for a rear mounted engine provides better heat expelling mechanism and thus the vehicle's engine efficiency and comfort level of passengers sitting.in rear of the vehicle on the passenger seat, is increased.

We claim:
1. A cooling system for rear mounted engine (9) of a vehicle(lO) comprising:
a radiator (43,63,93,123) , with two faces mainly a first face (43A) and a
second face (43B); wherein the said radiator (43,63,93,123) has its said
first face (43A) facing the outer atmosphere of the vehicle(lO);
a fan shroud (46); wherein the said fan shroud(46) is mounted on the said
radiator 's second face (43B);
a fan (45,75, 95,104) mounted on the said fan shroud (46);
and
a radiator duct (42,62,91,123); wherein the said radiator duct
(42,62,91,123) has two ends mainly a first end and a second end; the first
end envelopes the said fan shroud (46) and the second end is open to
atmosphere through a vent on side panel (44, 74).
2. The cooling system for rear mounted engine (9) as claimed in Claim 1 wherein the radiator duct (42, 62, and 91,123) extends from the fan shroud (46) up to the left side panel (44).
3. The cooling system for rear-mounted engine (9) as claimed Claim 1 extends from the fan shroud (46) up to the right side panel (74) of the said vehicle.
4. A cooling system for rear mounted engine (9) of a vehicle(lO) comprising:
a radiator (43,63,93,123) , with two faces mainly a first face (43A) and a~ second face (43B); wherein the said radiator (43,63,93,123) has its said first face (43A) facing the outer atmosphere of the vehicle(lO);

a fan shroud (46); wherein the said fan shroud(46) is mounted on the said
radiator's second face (43B);
a fan (45,75, 95,104) mounted on the said fan shroud (46);
and
a radiator duct (42,62,91,123); wherein the said radiator duct
(42,62,91,123) has two ends mainly a first end and a second end; the first
end envelopes the said fan shroud (46) and the second end is open to the
outer atmosphere through an opening on the chassis (4) of the said vehicle
(10).
5. The cooling system for rear mounted engine (9) as claimed in Claim 4 wherein the radiator duct (42, 62, and 91,123) extends from the fan shroud (46) up to a hole on the chassis (4) of the said vehicle (10) in the rear cabin space.
6. The cooling system for rear mounted engine (9) as claimed in Claim 1 or Claim 4 wherein the said fan (45, 75, 95, and 104) induces air in the vehicle running direction (F).