FIELD OF INVENTION

The present invention relates to a radiator unit for a motorcycle and more particularly to layout of radiator unit in a scooter type motorcycle.

BACKGROUND OF THE INVENTION

The conventional radiator unit for a motorcycle is disclosed in Patent document 1: JPH01233187 and Patent document 2: JP4360932B2.. In the invention disclosed in Patent document 1, a liquid cooled motorcycle has a radiator unit which is arranged in a space formed between leg shield and a front cover. Cooling of the radiator unit is achieved with the help of travelling wind passing through an outer face of said radiator unit, in a vehicle running condition. Since the radiator unit is cooled by natural air alone, cooling efficiency is not achieved to sufficiently cool the engine. Also, since the radiator unit is located away from the engine there is a requirement for lengthy hoses for transfer of cooling liquid from an engine jacket to the radiator unit and vice versa. In the invention disclosed in Patent document 2, the liquid cooled motorcycle has a radiator unit arranged outside a cooling fan and is connected to the one end of crankcase support member in a manner such that the cooling fan covers the radiator unit from the vehicle side. This arrangement of the radiator unit in front of the cooling fan causes the radiator unit to project outside from the lower part of crankcase. In the present disclosure, the radiator unit is cooled by the cooling fan axially mounted to the crankshaft, which sucks hot air around the radiator unit and disperses hot air through air discharge ports located at downside of the radiator unit. Said air discharge ports are located very close to a foot rest, where a pillion rider rests his/her foot, the hot air coming out from a vent of the radiator unit hit the pillion rider legs and gives uncomfortable riding experience to the pillion rider: The present invention has been made in order to overcome the foregoing problems of the related arts, and provides a layout for mounting.of the radiator unit.

OBJECT OF THE INVENTION

The main objective of the present invention is to enhance cooling efficiency of a swinging engine which is liquid cooled, by arranging a radiator unit in a position such that cooling air smoothly flows from a cooling fan to t^e radiator unit to effect cooling of the radiator unit. Consequently, performance of the swinging engine can be improved and life of the swinging engine can be prolonged. Another object of the present invention is to arrange the radiator unit close to the swinging engine. Still another object of the present invention is to arrange the radiator unit in a manner such that hot air around the radiator unit is not carried to a pillion rider's foot. Yet another object of the present invention is to arrange the radiator unit in a manner such that the same is not visible outside so that external appearance of a motorcycle is enhanced when viewed from a motorcycle sideward direction.

SUMMARY OF THE INVENTION

The above and other objects are achieved, in accordance with the present invention by arranging a radiator unit at least partially above a muffler, at least partially above the cooling fan, below a rear portion of a rear frame of the motorcycle and substantially behind the swinging engine, in a manner such that the radiator unit is covered at least partially by a side cover . when viewed from a motorcycle sideward direction. Further, a top portion of the radiator unit is mounted to a rear portion of the rear frame by means of brackets. Cooling of the radiator unit is achieved with the aid of the cooling fan swingably and opertively connected to the swinging engine. A cooling air blowing from the cooling fan is directed to the radiator unit to cool the liquid inside said radiator unit. Further, a cooling fan cover, extending upwardly from the cooling fan is connected to a side portion of the radiator unit through a flexible connecting air passage. Thus, while the top portion of the radiator unit is fixedly connected to the rear frame, a side portion of the radiator unit is connected the cooling fan, which in turn is swingably connected to the swinging engine. As a result, a portion connecting the radiator unit and the cooling fan, in the form of the flexible connecting air passage, cannot be provided as a rigid member in . order to ensure durability of the flexible connecting air passage. Therefore, an expansion joint which gives flexibility to the flexible connecting air passage when the swinging engine swings, is provided between the cooling fan cover and the flexible connecting air passage. The expansion joint also dampens vibrations coming from the swinging engine.

Further, a plurality of cooling fan blades are arranged in such a way to direct the cooling air to the radiator unit via the cooling fan cover and the flexible connecting air passage. The cooling air coming from the cooling fan flows to the radiator unit via the flexible connecting air passage and flows but through discharge ports formed in a bottom and rear side of the radiator unit. Thus, the arrangement of the radiator unit in accordance with the above disclosure ensures that there is a continuous and smooth flow of the cooling air from the cooling fan to the radiator unit through the flexible connecting air passage. Further, hot air from the radiator unit is dispersed at a rear end of the motorcycle through the discharge ports formed therein. Therefore, it is ensured that hot air from the radiator unit does not flow towards a rider's legs. Moreover, since the radiator unit is arranged close to the swinging engine, a problem associated with the use of lengthy hoses is also eliminated. Further, according to the present invention, the radiator unit and the flexible connecting air passage are arranged at least partially behind the side cover of the motorcycle, therefore the radiator unit is not visible from outside when the motorcycle is viewed from a motorcycle sideward direction. The side cover is disposed on a lower side of a seat and it covers the radiator unit at least partially. Summary provided above explains the basic features of the invention and does not limit the scope of the invention. Other objects, novel features and advantages of the invention will become more apparent to the person skilled in the art from the following detailed description when taken in conjunction with the accompanying drawings. Scope of the invention will be based on the claims provided.

BRIEF DESCRIPTION OF DRAWINGS

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

FIG.1 illustrates a right side view of a motorcycle in accordance with the present invention.

FIG.2 illustrates a right side view of the motorcycle depicting an arrangement of a radiator unit in accordance with the present invention.

FIG.3 illustrates a rear view of the motorcycle depicting essential embodiments in accordance with the present invention.

FIG.4 illustrates an enlarged top view of a rear portion of the motorcycle depicting essential embodiments in accordance with the present invention.

FIG.5 illustrates a right side view of a rear portion of the motorcycle with essential embodiments in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Exemplary embodiments detailing arrangement of a radiator unit, in accordance to the present invention will be described hereunder with reference to the accompanying drawings. Various aspects of different embodiments of the present invention will become discernible from the following description set out hereunder. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. It is to be rioted that terms "upper", "lower", "right", "left", "front", "rear", "downward", "upward", "top", "bottom" and like terms are used herein based on the illustrated state or in a standing state of the motorcycle with a rider sitting thereon. Furthermore, a longitudinal axis refers to a front to rear axis relative to the motorcycle, while a lateral axis refers to a side to side, or left to right axis relative to the motorcycle. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. It is to be noted that although the present invention has been exemplified for a scooter type motorcycle, however, the present invention may not be restricted only to a scooter/type motorcycle and is applicable to any two wheeled,motorcycle.

FIG. 1 to FIG. 5 depict enabling arrangements of the radiator, the details of which are described below. Referring to FIG. 1, the motorcycle 101 includes a body frame assembly comprising a head tube 102, a down frame 103 extending rearwardly and downwardly from said head tube 102, and a rear frame 104 extending rearwardly and inclinedly upwards from said down frame 103. The head pipe 102 pivotally supports a front fork 105 that is steerable to the left and right. A handle bar assembly 106 provided above the front fork 105 allows steering of a front wheel 107. A headlight assembly (not shown) is supported on the handle bar assembly106. The front wheel 107 is journaled to a lower end of the front fork 105. A front fender 108 is provided to cover an upper portion of the front wheel 107. Further, a front cover (not shown) is provided to cover a forward facing side of the body frame assembly. A side cover 111 is disposed to cover left and right side surfaces of the rear frame 104. A seat 112 is disposed above the side cover. 111. A fuel tank 113 is arranged below the seat 112. The fuel tank 113 is supported at an upper portion of the rear frame 104; and a storage box 114 is supported besides the fuel tank 113. The seat 112, which can be opened and closed manually, covers both the fuel tank 113 andithe storage box 114.

A swinging engine E is arranged downwardly and in front of the fuel tank 113. The swinging engine E which is mounted to the rear frame 104 by means of a toggle link (not shown) swings up and down. In the present embodiment, the swinging engine E is of a liquid cooled type. The swinging engine E is powered by an air fuel mixture sent in by a throttle body (not shown) to a combustion chamber thereof. Combustion gases generated by the swinging engine E is let out as exhaust from a muffler 115 extending along a right hand side of the motorcycle 101. An exhaust pipe 116 extending rearwards from a cylinder head of the swinging engine E is operatively connected to the muffler 115. Power from the swinging engine E gets transmitted to a rear wheel 117 operatively connected to said swinging engine E by a continuously variable transmission which is located on the left hand side of the motorcycle 101.Further, a radiator unit 120 provided to cool said swinging engine E. Said radiator unit 120 is located at least partially behind the side cover 111 and on the right hand side of the motorcycle, in a manner such that the radiator unit 120 is not completely visible when viewed from the right hand side. FIG.2- FIG.5, represent details of the enabling arrangements of the radiator unit 120 in the motorcycle 101 as per the present invention.

The motorcycle 101 is provided with the radiator unit 120 for cooling the swinging engine E. As may be seen in the figure, the radiator unit 120 is arranged at least partially, above the muffler 115. The exhaust pipe 116 coming out from the swinging engine E and which is connected to the muffler 115 is arranged below a cooling fan 130 provided with a cooling fan cover 131 as viewed from a right hand side of the motorcycle 101. Said cooling, fan 130 is swingably operatively connected to the swinging engine E. Particularly the cooling fan 130 is operatively connected to a crankshaft (not shown) of said swinging engine E and is disposed to a right hand side of said swinging engine E. With reference to FIG.2, a description is given of an arrangement .of the radiator unit 120 with respect to an embodiment of the present invention. The radiator unit 120 is arranged at least partially above the muffler 115 and is mounted to the upper portion of the rear frame 104 by means of radiator unit mounting brackets 140,140a, in a manner such that the radiator unit 120 is disposed at least partially above the muffler 115 and substantially below the rear frame 104. Further, the radiator unit 120 is disposed substantially above the cooling fan 130. FIG.2, FIG.3 & FIG.4 depict an arrangement of the radiator unit 120, detailing a flow path of cooling liquid to and from the radiator unit 120. The radiator unit 120 includes a radiator cover 120a to cover saidiunit 120 at least partially.

With reference to FIG.2 & FIG.3, a reservoir 150 located between a tail lamp housing (not shown) and a fuel tank 113 is used to store and transmit a cooling liquid to be circulated to the swinging engine E through the radiator unit 120. The reservoir 150 is mounted to the rear frame portion 104 by means of mounting brackets 150a and is connected to the radiator unit 120 by a hose 122. The reservoir 150 is provided with a liquid refill supply pipe 119 which extends sideways from a reservoir tank portion. Thus, the liquid refill supply pipe 119 extends sideways with respect to the rear frame 104. A cap 119a which can be opened and closed by rotational operation is disposed to close one end of the liquid refill supply pipe 119. Further, an opening 123 is formed on a right side of said reservoir 150. One end of the hose 122 is connected to the opening 123 and other end of the hose 122 is connected to a top left side of the. radiator unit 120. Thus, the cooling liquid is supplied to the radiator unit 120 from the reservoir 150 through the hose 122. Further, as illustrated in FIG.4, the radiator unit 120 has a radiator inlet pipe 125 connected to a pump 118 mounted on an engine jacket at a portion of a cylinder head of the swinging engine E. The radiator inlet pipe 125 carries the cooling liquid circulated in the engine jacket and pumped by the pump 118 back into the radiator unit 120.

Thus, the heat from the swinging engine is transmitted to the radiator unit 120 through the cooling liquid. The radiator inlet pipe 125 is routed under the air cleaner tube outlet 126 from the pump 118 to the radiator unit 120 to arrest the swinging action of the radiator inlet pipe 125. Further, a thermostat 135 is provided in the swinging engine E in order to monitor a temperature inside the swinging engine E continuously. When the temperature inside the swinging engine E exceeds a threshold value as measured by the thermostat 135, the cooling liquid flows into the engine jacket through a radiator outlet pipe 136. Thus, the cooling liquid gets circulated between the swinging engine E and the radiator unit 120, carrying away heat from the swinging engine E. However, in order to ensure good cooling performance of the cooling liquid, it is essential to maintain temperature of the cooling liquid. The same is achieved by ensuring cooling of the radiator unit 120, where the cooling liquid gets stored for brief intervals of time. FIG.5 depicts an arrangement of the radiator unit 120, detailing a flow path of cooling air to the radiator unit 120 from the cooling fan 130. Enhanced cooling of the radiator unit 120 as per an embodiment of the present invention is achieved with the help of the cooling fan 130. In the ■ present embodiment, the cooling fan 130 is mounted on an extended portion of crankshaft of the swinging engine E behind a magneto (not. shown).

Further, the cooling fan 130 includes a cooling fan cover 131. As per one embodiment of the present invention, the cooling fan cover 131 may be integrally provided with the cooling fan 130. However, in a second embodiment of the present invention the cooling fan cover 131 may be detachably attached to the cooling fan 130. The cooling fan cover 130 thus provided as per the first embodiment or the second embodiment of the present invention covers an external surface of said cooling fan 130 and extends upwardly and rearwardly from the cooling fan 130 towards the radiator unit 120. Thus, the cooling fan 130 is arranged to be located substantially in front of the radiator unit 120 and downwardly thereof. A flexible connecting air passage 160 is used to connect the cooling fan cover 131 and the radiator cover 120a. The flexible connecting air, passage 160 thus extends from the cooling fan cover 131 upto the radiator cover 120a and is subject to swinging motion when the cooling fan 130 swings along with the swinging engine E. Therefore, in order to ensure, that the flexible connecting air passage 160 is not damaged due to the swinging motion, an expansion joint 165 is provided between the flexible connecting air passage 160 and the cooling fan cover 131, so as to give an elastic movement to the flexible connecting air passage 160 when the swinging engine E swings while riding. In one embodiment, the expansion joint 165 is provided in the- form of bellows. However, in another embodiment flexibility of the flexible air passage 160 may be achieved by providing any other means.

- As per an aspect of the present embodiment, the expansion joint 165 is integrally formed within the flexible connecting air passage 160. Thus, one end of the flexible connecting air passage 160 is connected to the cooling fan cover 131 through the expansion joint 165, and another end of the flexible connecting air passage 160 is connected to the radiator cover 120a. Thus, the cooling fan cover 131 extends into the flexible air passage 160. Flexibility of the flexible connecting air passage 160 can also be attained as per another aspect of the present embodiment by integrally providing the expansion joint 165 within the cooling fan cover 131 so that the cooling fan cover 131 may be flexibly connected to the flexible connecting air passage 160. Thus, the radiator unit 120 may be flexibly connected to the cooling fan 130 as per the present embodiment. In the present embodiment, the cooling fan cover 131, flexible, connecting air passage 160 and the expansion joint 165 are made of a resin or the like. Further, as illustrated in FIG.5, the cooling fan cover 131 is provided with a grille type vent 131a for air suction. The grille type vent 131a exposes a plurality of cooling fan blades 132 disposed behind the grille type vent 131a. Said plurality of cooling-fan blades 132 are arranged in such a way so as to direct the cooling air to the radiator unit 120 via the cooling fan cover 131 and the flexible connecting air passage 160.

In a running condition of the motorcycle 101, when the cooling fan 130 is rotated by the crankshaft (not shown) of the swinging engine E; the outside air is sucked by the cooling fan 130 and transmitted to the radiator unit 120. Thus, the cooling liquid filled inside the radiator unit 120 gets cooled by the cooling air transmitted from the cooling fan 130 via flexible connecting air passage 160. Thereby, heat around the radiator unit 120 subsides and hot air around the radiator unit 120 gets discharged via discharge ports 120b formed at a rear end of the radiator cover 120a in a bottom side thereof. The cooling liquid is circulated to the engine jacket provided on the cylinder block and cylinder head of the, swinging engine. The cooling liquid thus cooled flows from the engine jacket to the radiator unit 120 based on output given by the thermostat 135. The pump 118 mounted on the cylinder head pumps the cooling liquid from the> engine jacket to the radiator unit 120. Flow of the cooling liquid between the engine jacket and the radiator unit 120 is controlled by a valve (not shown), provided in the thermostat 135. Further, hot air released from the radiator unit 120 during cooling of the cooling liquid contained therein is discharged away from the radiator unit 120 by a plurality of air discharge ports 120b formed at a rear end of the radiator cover 120a in a bottom side thereof.

Thus, hot air gets discharged to a rear side of the motorcycle 101, away from a footrest where a rider places his/her legs, thereby ensuring riding comfort of a pillion rider. Additionally, in order to prevent exhaust heat emitted by the muffler 115 from entering the radiator unit120 through conduction, a muffler protector 115a is disposed over top of the muffler 115. Further, the radiator cover 120as is provided with mounting extensions 121, 121a which are fastened with the. radiator unit mounting brackets 140,140a. Thus, arrangement of the radiator unit 120 as per an embodiment of " the present invention enables enhanced cooling of the radiator unit 120. Moreover, the arrangement of radiator unit 120 as per an embodiment of the present invention also ensures that the radiator unit 120 is not projected: outwards in a motorcycle width direction and is covered by the side cover 111 of the motorcycle 101. In this layout of the radiator unit 120, the same is not: fully viewable to a person who is looking at the motorcycle from a motorcycle sideward direction. Thus, appearance of the motorcycle gets enhanced. Further, according to the present invention, since the radiator unit 120 is disposed near the swinging engine E in a compact manner, use of lengthy, hoses is also done away with.. While the present invention has been shown and described with' reference to the foregoing preferred embodiments, it will be apparent to those, skilled in the art that changes in form, connection, and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims:

We Claim:

1. A motorcycle (101) comprising: a head tube (102); a down frame (103) extending rearwardly and downwardly from said head tube (102); a rear frame (104) extending rearwardly and upwardly from said down frame (103); a side cover (111) attached to the rear frame (104) and covering said rear frame (104) from a left and right side thereof; a swinging engine (E) mounted to the rear frame (104); a rear wheel (117) operatively connected to the swinging engine (E); a cooling fan (130) operatively connected to the swinging engine (E) and projecting outwards therefrom in a motorcycle width direction; a muffler (115) operatively connected to said swinging engine (E) and positioned adjacent to one side of the rear wheel (117) and behind the cooling fan (130), so as to extend along a right hand side of the motorcycle (101); and a radiator unit (120) positioned below an upper portion of the rear frame (104), at least partially above the muffler (115) and substantially behind the cooling fan (130), in a manner such that the radiator unit (120) is operatively connected to the cooling fan (130) through a flexible connecting air passage (160).

2. The motorcycle (101) as claimed in claim 1, wherein the cooling fan (130) includes a cooling fan cover (131) covering an external surface •thereof.

3. The motorcycle (101) as claimed in claim 1, wherein the flexible connecting air passage (160) includes an expansion joint (165)

4. The scooter type motorcycle (101) as claimed in claim 1, wherein the cooling fan cover (131) extends upwardly from the external surface of-the cooling fan (130) towards the radiator unit (120).

5. The motorcycle (101) as claimed in claim 1, wherein the cooling fan cover (131) includes a grille type vent (131a).

6. The motorcycle (101) as claimed in claim 1, wherein the grille type vent (131 a).exposes a plurality of cooling fan blades (132) capable of; directing a cooling air to the radiator unit (120) through the flexible) connecting air passage (160).

7. The motorcycle (101) as claimed in claim 1, wherein the cooling fan cover (131) is connected to the radiator unit (120) through'the flexible connecting air passage (160).

8. The motorcycle (101) as claimed in claim 1, wherein the radiator unit; (120) includes a radiator cover (120a) covering the radiator unit (120) at least partially.

9. The motorcycle (101) as claimed in claim 1, wherein the radiator cover; (120a) includes a plurality of discharge ports (120b) formed at a rear end and in a bottom side thereof.

10. The motorcycle-(101) as claimed in claim 1, wherein the radiator unit (120) is at least partially covered by the side cover (111).