DESC:FIELD OF INVENTION
[0001] The present invention relates to a cooling system of an internal combustion engine and more particularly to a coolant reservoir for said cooling system.
BACKGROUND OF INVENTION
[0002] In an internal combustion engine, combustion of fuel inside the cylinder, powers a transmission system along with production of a large amount of heat energy. This heat energy is mainly concentrated near the cylinder block and cylinder head of the internal combustion engine. It is necessary to maintain an engine temperature within an optimum range to improve the efficiency and operate the engine within the safe limits of operation. Thus, the heat generated in the cylinder block due to continuous firing of fuel inside said cylinder, which may gradually increase the cylinder head temperature, it is required that the heat from the cylinder head of the engine be properly dissipated to the atmosphere. Generally, for engines with lesser volume of cylinder, natural air-cooling is sufficient to lower down the cylinder head and cylinder block temperature wherein the cylinder head and cylinder block portions of the engine is cooled by the air that hits the cylinder block and the cylinder head while the vehicle is moving.
[0003] In vehicles which have a higher cylinder volume, natural air cooling is many a times insufficient to bring down the cylinder head or cylinder block temperature within a standard operating range. This problem of overheating of cylinder head and cylinder block is solved by circulating a cooling liquid (also called as coolant) through the cylinder head and cylinder block using a heat exchanger. Further, the coolant is circulated through the cylinder head and cylinder block by help of a pump. The heat absorbed by the coolant while travelling across the cylinder head and cylinder block is dissipated by means of a heat exchanger equipped either by a cooling fan and or by natural cooling. A reservoir tank is an expansion or overflow tank used in closed loop liquid cooling systems to reduce loss of coolant and to ensure proper filling of cooling system under all conditions. The coolant reservoir stores excess coolant for continuous supply to the liquid cooling system as & when required. The reservoir is also the refilling point of the cooling system for the customer. Since coolant flowing through the cylinder head and cylinder block has a tendency to diminish over time, a reservoir is used to store such a coolant. In such a vehicle with swinging engine, the coolant circulated through cylinder block and cylinder head is used to extract the heat and thus cool down the engine. Different cooling system for extraction of heat from the internal combustion is possible. In a two-wheeler, placing, locating and orientation of heat exchanger and the coolant reservoir becomes a great challenge due to space constraints.
[0004] The level of coolant in the reservoir is an important indicator of the health of cooling system. In the known prior arts, the coolant reservoir is either located under the seat inside the utility box or in the space in-between the utility box and fuel tank or on sides of the utility box. In either cases, either the reservoir cap is not accessible without opening the utility box or direct inspection of the coolant level in the coolant reservoir is not possible. In such an arrangement of coolant reservoir, visibility of coolant level for inspection and accessibility of the coolant reservoir cap for refilling are key parameters for installation of coolant reservoir. Hence, there is a requirement of a coolant reservoir that is easily accessible for refilling and regular inspection of coolant level.
SUMMARY OF THE INVENTION
[0005] In order to obviate the limitations and the problems associated with the locations of reservoir for cooling system as described above, the present invention discloses a coolant reservoir placed under a rider seat and in front of a utility / storage box. The reservoir is mounted on the utility box 17 via mounting bolts. The utility box 17 is further provided with an opening on the reservoir side, which will reveal the coolant level to the user. According to one embodiment of the present invention, neck of the reservoir extends away from the utility box 17, towards the cover front and the reservoir cap is accessible through a snap fit window that is further accessible through an opening in a cover front.
[0006] The reservoir as disclosed in the present invention is easy to mount (on the utility box 17). The reservoir level is easily visible through the utility box 17, once the seat is open and through the cover front. The filling cap for the reservoir is easily accessible from the cover front through a snap fit window on the cover front has an added advantage that no additional tool required by customer to refill coolant. In the present invention, the reservoir is not a swinging part mounted on the engine, thus avoids coolant splashing and overflowing. Furthermore, the reservoir is close to the engine i.e. the distance of the reservoir from engine is lesser thus, a lesser hose length and shorter path is required for the coolant to travel from coolant reservoir to the engine. A secured coolant reservoir further ensures that ignorant users do not refill the reservoir with tap water or children do not tamper with the contents of the reservoir.
BRIEF DESCRIPTION OF DRAWINGS
[0007] Figure 1 illustrates perspective view of a typical type two-wheeler.
[0008] Figure 2 illustrates side view of a typical two-wheeler with heat exchanger 12 mounting & reservoir location according to the present invention.
[0009] Figure 3 illustrates side view of the vehicle frame to illustrate reservoir mounting.
[00010] Figure 4 illustrates zoomed view of the reservoir window in closed condition on front cover.
[00011] Figure 5 illustrates detailed view of the reservoir window on front cover in open condition.
DETAILED DESCRIPTION OF THE INVENTION
[00012] The cooling system as described in the present invention comprises of a heat exchanger 12, a coolant reservoir, a heat exchanger 12 mounting and a coolant reservoir mounting. The coolant reservoir as described in the present invention is easy to mount and locate (on the utility box 17). The reservoir level is easily visible through the utility box 17, once the seat is open, and through the cover front, once the snap fit window is open. The filling cap for said reservoir is easily accessible from the cover front, once the snap fit window is open. The present invention provides an added advantage of no need of tools by customer to refill coolant. The reservoir is not a swinging part mounted on the engine, thus avoids coolant splashing and overflowing. Furthermore, the reservoir is close to the engine i.e. the distance of the reservoir from engine is lesser thus, a lesser hose length and lesser path for the coolant travel is needed. The reservoir cap is not accessible directly. This ensures that ignorant users do not refill the reservoir with tap water or kids don’t tamper with the contents of the reservoir.
[00013] The present invention proposes a more efficient location of installing the coolant reservoir for a continuously variable transmission (CVT) type engine wherein the assembly, serviceability and inspection is improved. The coolant reservoir as disclosed in the present invention is mounted on a cross bar which is welded or rigidly joined to the vehicle side tubes. In yet another embodiment, the coolant reservoir is mounted on a cross bar between atleast two side frames members using a plurality of fasteners.
[00014] Figure 1 shows a rider seat 1, a floorboard 5, step through vehicle 10, side cover 11, heat exchanger 12 and a front cover 13. In general, a reservoir has two hoses, atleast one pressure valve and atleast one vacuum valve connected to it. A first hose connects the reservoir and heat exchanger 12. This hose carries coolant from heat exchanger 12 to reservoir when a pressure valve opens and from reservoir to heat exchanger 12 when vacuum valve opens. This hose connects to the reservoir at its bottom surface. The second hose connects on the reservoir at a high point, close to the filler neck. This second hose extends from the reservoir to the ground. It carries overflowing coolant (due to splashing or excess expelling from the heat exchanger 12) to the ground, safely out of the vehicle. The customer can thus realize that there is an abnormally high level of coolant in the reservoir and detect a problem in the liquid cooling system.
[00015] Figure 2 shows a rider seat 1, a step through two wheeled vehicle 10, heat exchanger 12, front cover 13, coolant reservoir 14, cross member 15, vehicle left Lt, vehicle right Rt, vehicle rear R and vehicle front F. The coolant reservoir is mounted under the rider seat 1 in front of the utility box 17 when viewed from the side of the vehicle. There are two mounting holes in the utility box 17 face and two mounting lugs on the reservoir. Two bolts assemble the reservoir to the utility box 17 via these lugs. The bottom portion of the coolant reservoir is mounted on to a cross member 15.
[00016] Figure 3 shows vehicle frame structure with a coolant reservoir 14, cross member 15, LH side tube 31, and RH side tube 32 and down tube 33. The coolant reservoir 14 is mounted on a cross member 15 which is ultimately mounted on the LH side tube 31 and RH side tube 32. The neck cap is further includes a window on the front cover for easy accessibility during filling of coolant and regular inspection of the coolant level in the coolant reservoir 14. The coolant reservoir 14 provided with a neck cap in the front portion provides easy accessibility and serviceability.
[00017] Figure 4 shows step through two wheeled vehicle 10, front cover 13, reservoir cap 41 and reservoir window 42. The reservoir has a filler neck with a removable cap that extends towards the cover front and away from the utility box 17. This removable cap 41 is accessible through a snap fit window 42 in the cover front 13. The customer can open the window 42 as and when required and refill coolant easily.
[00018] Figure 5 shows the step through two-wheeled vehicle 10 with the front cover 13, reservoir cap 41 and reservoir window 42. The reservoir window 42 when opened reveals the reservoir 14 to access the reservoir cap 41. The coolant reservoir 14 is preferably made up of translucent plastic. The translucent plastic aids in visually inspecting the level of the coolant level in the coolant reservoir 14. Furthermore, the reservoir window 42, which covers the coolant reservoir 14 from the front, accommodates grilled openings on the window. Thus, through the grills, the monitoring of coolant level in the reservoir is performed and for further addition of coolant, the reservoir window can be opened to access the reservoir cap 41. The user can inspect the coolant level in the reservoir 14 through said see through grill and judge if refilling is necessary.
[00019] The coolant reservoir location and arrangement as described above in the present invention provides a coolant reservoir for cooling system of a liquid cooled engine which is easy to inspect, easy to access, easy to maintain and easy to service.
,CLAIMS:We claim:
1. A two wheeled vehicle (10) comprising:
a front cover (13) substantially above the floorboard to protect a lower front portion below rider seat (1) of the vehicle;
a heat exchanger (12), the heat exchanger (12) connected to an internal combustion engine (15) in a closed circuit for heat exchange;
a tandem rider seat (1) mounted on the vehicle body frame, the tandem seat including a front occupant seat on which a driver is to be seated and a rear occupant seat on which a passenger is to be seated, the front occupant seat and the rear occupant seat being provided integrally or separately with each other;
a coolant reservoir (14) with an opening cap (22), the coolant reservoir (14) storing a coolant used in the heat exchanger (12) and also filled throughout the closed circuit;
wherein to enhance the accessibility and to improve inspection of the coolant reservoir (14), the coolant reservoir (14) is located below said rider seat (1) substantially in front portion of utility box (17) rear to said front cover (13).

2. The two wheeled vehicle (10) as claimed in Claim 1 wherein said front cover (13) is equipped with a window (42) to access the opening cap (41) of said coolant reservoir (14).

3. The two-wheeled vehicle (10) as claimed in claim 1 wherein said window (42) being provided with plurality of slits (22) to inspect coolant level in said coolant reservoir (14).