VARIABLE COOLING SYSTEM FOR A STRADDLE TYPE VEHICLE

FIELD OF THE INVENTION

[0001] The present subject matter relates generally to a power unit, and more particularly, to a variable cooling system for cooling a power unit in a straddle type vehicle.

BACKGROUND OF THE INVENTION

[0002] Typically in a straddle type vehicle, a swinging power unit is located below the seat at a lower rear portion of the vehicle spanning from the underseat cover to the rear wheel hub. In particular, the anterior portion of the power unit is substantially enclosed by a cooling cowl.

[0003] The power unit, particularly the cylinder head, is generally cooled by forced cooling through a fan mounted on the right side of the crankcase. The fan forces the air inside a cooling cowl which further directs this air towards the cylinder head. The cooling cowl profile has a fan covering portion covering the said fan which is always exposed irrespective of whether the fan is operative or inoperative. The atmospheric air is sucked in by the fan through a grated air inlet present in the fan covering portion. This air inlet may facilitate entry of dirt, mud, rain water or like unwanted foreign particles into the cooling cowl and may harm the fan.

[0004] Usually the fan is mounted on a crankshaft and raises the air flow as the engine speed increases irrespective of the engine temperature. Since the air inlet in the fan covering portion is permanently open, the air volume entering the power unit causes delay in engine warm up during cold start conditions.

[0005] Hence, the present subject matter is directed to overcome all or any of the problems as set forth above and obviate the lacunae in the prior art. Therefore, it is an object of the present invention to provide a variable cooling system for cooling the power unit of a straddle type vehicle, including its cylinder head and also preventing foreign matter like water, dust etc from entering a cooling cowl of the power unit. It is another object of the present invention to disclose a cooling system for providing controlled air inlet into a cooling cowl of a power unit for a straddle type vehicle. It is yet another object of the present invention to provide a variable cooling system which is retrofittable and cost effective.

SUMMARY OF THE INVENTION

[0006] To this end, the present invention discloses a variable cooling system for controlling the inlet of air into a cooling cowl of a fan cooled internal combustion engine, the variable cooling system comprising: a baffle control portion, a baffle cover connected to and exterior to the baffle control portion, and a guide plate mechanically connected to the baffle control portion, wherein the variable cooling system is operatively controlled by a temperature controlled, spring-loaded solenoid.

[0007] According to an aspect of the invention, the variable cooling system is connected to a fan covering portion of the cooling cowl and is disposed exterior to the cooling cowl.

[0008] According to another aspect of the invention, the baffle control portion comprises at least one baffle and having at least two identical halves connected to each other through a press fit lock mechanism, the halves laterally covering the baffle and also having at least one opening and at least one keyway configured for supporting the baffle. Further, each baffle comprises a fixed projection and a movable projection at both of its ends, the fixed projection supported into the corresponding opening and the movable projection supported into the corresponding keyway of the halves of the baffle control portion and wherein further one end of each baffle is connected to the guide plate present laterally and outwardly to the baffle control portion,

[0009] According to a further aspect of the present invention, the baffle control portion further comprises an air inlet insert at its fan facing portion to support the baffle control portion for attachment with the fan covering portion of the cooling cowl; and the baffle cover is supported on the fan covering portion of the cooling cowl through a plurality of snap fitting attachment structures.

[00010] The foregoing objectives and summary provide only a brief introduction to the present subject matter. To fully appreciate these and other objects of the present subject matter as well as the subject matter itself, all of which will become apparent to those skilled in the art, the ensuing detailed description of the subject matter and the claims should be read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[00011] The above and other features, aspects, and advantages of the subject matter will be better understood with regard to the following description, appended claims and accompanying drawings where:

FIG. 1 is a typical straddle type vehicle according to the present invention.

FIG. 2 is a front view of the vehicle power unit according to the present invention.

FIG. 3 is a top sectional view of the vehicle power unit according to the present invention.

FIG. 4 illustrates a detailed view of the variable cooling system. assembly according to the present invention.

FIG. 5 shows the side and front views of the variable cooling system in the open state and with a baffle cover.

FIG. 6 shows side and front views of the variable cooling system in the open state without baffle cover.

FIG. 7 depicts the side and front views of the variable cooling system in the closed condition and with the baffle cover.

FIG. 8 depicts the side and front views of the variable cooling system in the closed condition and without baffle cover.

DETAILED DESCRIPTION OF THE INVENTION

[00012] In order that those skilled in the art, can understand the present invention, the invention is further described below so that various features of the variable cooling system thereof proposed here are discernible from the description thereof set out hereunder. However these descriptions and the appended drawings are only used for those skilled in the art to understand the objects, features, and characteristics of the present invention and not to be used to confine the scope and spirit of the present invention. In the supporting FIGs, the same reference numerals are given to members and parts having the same functions. In the ensuing exemplary embodiments, the vehicle is a straddle ride type vehicle like a scooter type motorcycle. However, it is contemplated that the concepts of the present invention may be applied to other types of vehicles within the spirit and scope of this invention. For example, the vehicle may be any straddle ride, type vehicle that may use forced air cooling for its power unit.

[00013] Further "front" and "rear", and "left" and "right" referred to in the ensuing description of the illustrated embodiment, except stated otherwise, refer to front and rear, and left and right directions as seen in a state of being seated on a seat of the vehicle. Furthermore, a longitudinal axis, except stated otherwise, refers to a front to rear axis relative to the vehicle, while a lateral axis, except stated otherwise, refers generally to a side to side, or left to right axis relative to the vehicle.

[00014] The present invention is now explained with the help of rendered FIGS. 1 to 8. FIG. 1 illustrates the side view of a concerned straddle ride type vehicle. Typically such a vehicle includes a body frame assembly made up of several tubes welded together which usually supports the body of the said vehicle. The vehicle has a steerable front wheel 110 and a driven rear wheel 111 driven by driving force generated by an engine (power unit) 102. The frame assembly 101 of the straddle ride type vehicle with the swinging power unit is an elongated structure, which typically extends from a forward end to a rearward end of the vehicle. It is generally convex in shape, as viewed from a side elevational view. The said frame assembly 101 includes a main frame and may also have a sub-frame. The sub-frame is attached to the main frame using appropriate joining mechanism. The frame assembly 101 includes a head tube (not shown) and a down tube that extends downward from head tube. The frame assembly is covered by a plurality of vehicle body covers including a front panel 115, a leg shield 116, an under seat cover 117 and a side panel 112.

[00015] A handlebar assembly 105 and a seat assembly 106 are supported at opposing ends of the frame assembly and a generally open area is defined there between known as floorboard 107 which functions as a step through space. The seat 106 for seating a driver and a pillion is placed forward to the fuel tank (not shown) and rearwardly of the floorboard 107. A fuel tank, for storing the fuel supplied to the engine, is disposed at the rear end of the vehicle above the rear wheel and the engine. A side stand, attached to the left side of the frame, is provided to the rear of the engine and supports the vehicle such that vehicle inclines to the left side.

[00016] A front fender 113 is provided above the front wheel 110 to avoid the said vehicle and its occupants'from being splashed with mud. Likewise a rear fender 109 is placed between fuel tank and rear wheel 111, and to the outer side in the radial direction of rear wheel. Rear fender 109 inhibits rain water or the like from being thrown up by rear wheel 111.

[00017] Typically, front 103 and rear 114 suspension assemblies are operatively positioned between the front 110 and rear 111 wheels and the frame assembly. The front suspension assembly 103 commonly is a telescopic fork arrangement while the rear suspension assembly 114 is a hydraulic damped arrangement.

[00018] In the said vehicle, the rear suspension swing arm typically supports the engine (power unit) 102 and a swing case 108. The engine and the swing case are integrally constructed for the embodied vehicle. In an embodiment of the present invention, the engine is a four stroke single cylinder engine and the swing case 108 is connected to a left side surface of a crankcase of the engine 102 so as to extend forward.

[00019] It is disposed on the vehicle frame with one end of the swing case 108 attached to the rear wheel hub in such a way that the power unit is substantially angularly disposed to the ground. The engine 102 is arranged horizontally, that is, its crankshaft is placed at right angles to the longitudinal direction of the vehicle body. Since the basic construction of an engine is known to those versed in the art, the details have been omitted.

[00020] FIG. 2 shows the front view of the anterior portion of the engine 102 comprising of a cylinder head 118. Positioned below the cylinder head 118 is a piston 125 connected to a crankshaft 122 through a connecting rod 121. The engine works when the piston 125 converts its reciprocatory motion into the rotatory motion of the crankshaft 122. The crankshaft motion is then transferred to the rear shaft 124 through a transmission system. The rear shaft 124 is connected to the rear wheel 111 as shown in the sectional view of the engine in FIG. 3.

[00021] During this process, significant heat is generated. A cooling cowl 200 is provided to significantly cool the engine, particularly cylinder head 118 and is mounted on the engine through a plurality of cooling cowl mounting points 204 which are joined to the corresponding points on the engine via known mechanism. A portion of the cooling cowl 200, namely a fan covering portion 201, covers a fan 123. The fan 123, mounted on a lateral end of crankshaft 122, sucks in atmospheric air through an air inlet 202 as the crankshaft rotates. The fan may include a centrifugal fan or an axial fan. The air inlet 202 allows the atmospheric air into the cooling cowl 200. The incoming air is aligned along a defined flow path and is radially directed towards the cylinder head 118 through the cooling cowl profile.

[00022] A variable cooling system for controlling the inlet of air inside the cooling cowl 200 is provided exterior to the fan covering portion 201 of the cooling cowl 200 and is illustrated in detail in FIG. 4. It mainly comprises a baffle control portion 302, a baffle cover 301 connected to and exterior to the baffle control portion and a guide plate 311 mechanically connected to the baffle control portion. The baffle control portion 302 further comprises of at least one rotatable baffle 304. In a preferred embodiment, the baffle control portion 302 comprises of a plurality of baffles 304 spaced equally and capable of opening and closing.

[00023] The baffle control portion 302 has at least two identical halves connected to each other through a press fit lock mechanism, wherein a small projection 312 of one half 302a is inserted into a corresponding recess 313 of the other half 302b. Further the halves 302a and 302b laterally cover the baffle 304 and also have at least one opening 307 and at least one keyway 308 configured for supporting the baffle.

[00024] Each baffle 304, at both of its ends, comprises of a fixed projection 305 fixed to rotate along an axis and a movable projection 306 which can rotate circumferentially along a path. The fixed projection 305 is supported into the corresponding opening 307 and the movable projection 306 is supported into the corresponding keyway 308 of the baffle control portion 302. The movable projection 306 is able to move along the keyway path upon opening and closing of the baffles 304. In a preferred embodiment, the baffle control portion 302 comprises of a plurality of openings 307 and a plurality of keyways 308 at both of its halves for accommodating the plurality of baffles 304.

[00025] According to an aspect, the baffle control portion 302 further comprises of an air inlet insert 309 at its fan facing portion to support the baffle control portion 302 for attachment with the fan covering portion 201 of the cooling cowl 200. The fan facing portion is present on the rear side of the baffle control portion 302.

[00026] Further, one end of each baffle is connected to the guide plate 311 present laterally and outwardly to the baffle control portion 302. The guide plate 311 contains a plurality of small holes in which the movable projection 306 of the baffle 304 after passing through the keyway 308 is finally held. The guide plate 311 is operably connected to a spring-loaded solenoid 310 through a known link mechanism. The solenoid 310 is further connected to a thermal sensor which maps the temperature of the engine. In a preferred embodiment, the guide plate 311 is linearly operated by the solenoid 310. The guide plate guides the movement of the movable projection of the baffles. The linear movement of the guide plate 311 is converted into rotating movement of the movable projection 306 of the baffles due to which the baffles may open and close depending upon the guide plate movement.

[00027] The baffle cover 301 is provided over an assembled baffle control portion 302. It covers the baffle control portion 302 and has a grated opening for allowing the atmospheric air inside. The baffle cover is supported on the fan covering portion 201 of the cooling cowl 200 through a plurality of attachment structures 303. The attachment structures 303 are snap fitted into the corresponding attachment points 203 on the cooling cowl 200 for supporting the baffle cover 301 on the cooling cowl 200. The baffle cover 301 also allows the mechanical connection between the solenoid 310 and the guide plate 311.

[00028] The working of the variable cooling system according to an embodiment of the present invention is now explained. The baffles 304 are located external to the air inlet 202 to control the air flow to the cooling cowl 200. The baffles can either be in open condition or in closed condition which may be controlled by an engine specific characteristic. In an embodiment of the present invention, the condition of baffles is controlled by the engine temperature by means of the thermal sensor and actuated through the solenoid 310. During cold start, the temperature is below a threshold temperature. Therefore the solenoid is not activated and hence the baffles remain closed in their default condition. Extremely small quantity of air is allowed into the cooling cowl 200 which helps the engine to warm up quickly. After continued operation for some time, the engine heats up and the thermal sensor activates the solenoid 310 after a threshold temperature is reached. The solenoid lifts the guide plate 311 through a known link mechanism thereby channelling the movable projection 306 along the keyway 308 to open the baffles 304 thus facilitating more air to enter into the cooling cowl 200. The solenoid 310 returns to its original position due to the spring force of the spring when the engine temperature returns below the threshold temperature. Thus, the opening and closing of the baffles is dependent on the temperature of the engine, the baffles being closed during cold start of the engine and the baffles being open when the engine temperature is above a predetermined threshold temperature.

[00029] FIG. 5 shows variable cooling system when the baffles are open and covered externally with the baffle cover. FIG. 6 shows side and front views of the variable cooling system in the open state without baffle cover. FIG. 7 depicts variable cooling system in the closed condition and with the baffle cover whereas FIG. 8 depicts the side and front views of the variable cooling system in the closed condition and without baffle cover. Furthermore, the components of the variable cooling system may be made of any material including plastic resin.

[00030] From the forgoing description, it will be appreciated that the present invention offers many advantages. The baffles remain closed when the vehicle is in parked condition. Hence mud, water and other foreign particles would not enter the cooling cowl. The present invention allows a controlled inlet of air into the cooling cowl for cooling the engine particularly the cylinder head. The closed baffles during the cold start of the engine ensure faster warming up of the engine. Additionally the present invention has the incidental advantage of being retrofittable on existing vehicles with slight labour.

[00031] The present subject matter is thus described. The embodiments described are chosen to provide an illustration of principles of the invention and its practical application to enable thereby one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore the forgoing description is to be considered exemplary, rather than limiting, and the true scope of the invention is that described in the appended claims.

We claim:

1. A variable cooling system for controlling the inlet of air into a cooling cowl of an air cooled internal combustion engine, the variable cooling system comprising: a baffle control portion, a baffle cover connected to and exterior to the baffle control portion, and a guide plate mechanically connected to the baffle control portion, wherein the variable cooling system is operatively controlled by a temperature controlled, spring-loaded solenoid and wherein the variable cooling system is disposed exterior to the cooling cowl.

2. The variable cooling system as claimed in claim 1, wherein a cooling fan is mounted external to the engine and supported on a crankshaft, the cooling cowl substantially covering the engine and the cooling fan, and including a fan covering portion for covering the cooling fan.

3. The variable cooling system as claimed in claim 1 or claim 2, wherein the variable cooling system is connected to the fan covering portion of the cooling cowl.

4. The variable cooling system as claimed in claim 1, wherein the baffle control portion comprises at least one rotatable baffle and having at least two identical halves connected to each other through a press fit lock mechanism, the halves laterally covering the baffle and also having at least one opening and at least one keyway configured for supporting the baffle.

5. The variable cooling system as claimed in claim 1 or claim 4, wherein each baffle comprises a fixed projection and a movable projection at both of its ends, the fixed projection supported into the corresponding opening and the movable projection supported into the corresponding keyway and wherein further one end of each baffle is connected to the guide plate present laterally and outwardly to the baffle control portion.

6. The variable cooling system as claimed in claim 1 or claim 5, wherein the guide plate is operably connected to the solenoid through a known link mechanism and wherein the guide plate is linearly operated.

7. The variable cooling system as claimed in claim 1, wherein the baffle control portion further comprises an air inlet insert at its fan facing portion to support the baffle control portion for attachment with the fan covering portion of the cooling cowl.

8. The variable cooling system as claimed in claim 1, wherein the baffle cover is supported on the fan covering portion of the cooling cowl through a plurality of snap fitting attachment structures.

9. The variable cooling system as claimed in any of the preceding claims, wherein the opening and closing of the baffles is dependent on the temperature of the engine, the baffles being closed during cold start of the engine and the baffles being open when the engine temperature is above a predetermined threshold temperature and wherein the variable cooling system is made of any material including plastic resin.

10. The variable cooling system substantially as herein described and illustrated with reference to the accompanying drawings.