Title of Invention

ELECTRICALLY DRIVEN VEHICLE

Abstract

An electrically driven vehicle comprising a transmission for transmitting power from a motor disposed on the front side of a motor disposed on the side of a rear wheel to said rear wheel,said transmission being disposed on one side of a vehicle body,wherein said electrically driven vehicle comprises. a charger disposed at a side of said transmission, a charger cooling fan disposed at an upper portion of said charger,and a body cover comprising side cover portions whose lower end positions are so set as to cover side portions of said charger cooling fan.

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] COMPLETE SPECIFICATION [See Section 10] "ELECTRICALLY DRIVEN VEHICLE" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, having a place of business at 1-1, Minamiapyama 2-chome, Minato-ku, Tokyo, Japan, „• , The following specification particularly describes the nature of the ,,£*inventioh and the manner in which it is to be performed:- The present invention relates to an electrically driven vehicle. [Detailed Description of the Invention] [0001] [Technical Field of the Invention] The present invention relates to an electrically driven vehicle, and particularly to an electrically driven vehicle having a fitting structure of heat-generating component parts such as a charger which enables good cooling while maintaining good appearance. [0002] " [Prior Art] As a power source for a driving motor of an electrically driven vehicle, there is used a secondary cell (battery) capable of being repeatedly utilized through recharging by a chemical reaction. One example of a motor scooter type electrically driven vehicle on which ^ 2 a charger for charging the battery is mounted is disclosed in Japanese Patent Laid-open No. Hei 5-112270. In the electrically driven vehicle, the charger is contained in a space provided at a lower rear portion of a seat, and, at the time of charging, a lid is opened, a cord disposed in the inside of the space is drawn out and is connected to a commercial power source, whereby passage of electric current can be achieved. [0003] Among such batteries, one provided with a cooling device is known. For example, Japanese Patent Laid-open No. Hei 5-69870 discloses a motor scooter type vehicle in which a cooling wind is fed by a cooling fan to a battery device disposed under a step floor. [0004] In the above vehicle, the cooling fan is disposed on the upper side of a rear portion of the battery device, namely, on the front side of a rear wheel and on the lower side of a seat, and a cooling wind is fed from the cooling fan to the batteries through a duct. [0005] [Problems to Be Solved by the Invention] Since the charger is a heat-generating body, cooling thereof must be taken into consideration. In the 3 above conventional vehicle disclosed in Japanese Patent Laid-open No. Hei 5-12270, however, the charger is contained in a space for difficult contact with the outside air, so that there is a demand for disposing the charger in a position for easy contact with the outside air, such as a side portion of the vehicle body, from the viewpoint of cooling performance. In that case, there is also a merit that a storage space under the seat can be secured. In addition, in order to further enhance cooling performance, it may be contemplated to provide the charger with cooling fins, but such an appearance that the cooling fins are conspicuous is not favorable. Therefore, there is a request for a fitting structure excellent in mounting property and good in both appearance and cooling performance. [0006] Furthermore, in addition to the charger, a down converter which is a heat-generating component is mounted on the electrically driven vehicle, and there is a demand for enhancing the cooling performance of the down converter. [0007] In consideration of the above problems, it is a first object of the present invention to provide an 4 electrically, driven vehicle which has a fitting structure for a charger good in both appearance and cooling performance and excellent in mounting property and which can enhance the cooling performance of a down converter. [0008] [Problems to Be Solved by the Invention] In the above battery device disclosed in Japanese Patent Laid-open No. Hei 5-69870, the entire part of the battery device is cooled by only one cooling fan. Therefore, a large type cooling fan is required, and, particularly in a motor cycle, there is a case where it is difficult to secure a space for mounting a comparatively large type cooling fan. In addition, where only one cooling fan is used, there is need for a contrivance for cooling uniformly the entire part of the batteries large in volume, or the cooling structure may be complicated. Therefore, an improvement in these points is desired. [0009] In consideration of the above problems, it is a second object of the present invention to provide an electrically driven vehicle by which it is easy to secure a space for mounting the cooling fan and an effect of cooling uniformly the entire part of the batteries can be 5 expected. [Means for Solving the Problems] In order to attain the first object described above, the first feature of the present invention is characterized in that, in an electrically driven vehicle including a transmission for transmitting power from a motor disposed on the front side of a rear wheel to the rear wheel, the transmission being disposed on one side of a vehicle body, the electrically driven vehicle includes a charger disposed on the opposite side of the transmission with the vehicle body therebetween, a charger cooling fan provided at an upper portion of the charger, and a body cover including side cover portions whose lower end positions are so set as to cover the charger cooling fan. [0011] According to the first characteristic feature, the charger and the transmission are disposed with good balance with the vehicle body therebetween, and a connection portion of the charger cooling fan and the charger which would easily be intricate in appearance is covered by the side cover portion, so that intricate appearance can be obviated. 6 [0012] Besides, the second feature of the present invention is characterized in that the motor extends in the width direction of the vehicle body with a motor shaft set nearly horizontally, and the charger has its lower end located on the upper side of a shaft of the rear wheel and is so disposed as to be contained within the front-rear length of the rear wheel. [0013] According to the second characteristic feature, the charger is disposed while avoiding interference with the motor, and is provided on the upper side of the shaft of the rear wheel, so that the bank angle of the vehicle body can be secured sufficiently, and mounting property of the charger is enhanced. [0014] Besides, the third feature of the present invention is characterized in that the charger cooling fan is so set as to take in air from the lower side and discharge the air to the upper side. The fourth feature of the present invention is characterized in that the electrically driven vehicle includes a stay for fitting the charger to the vehicle body, the stay is formed so as to form one wall portion of a wind duct extending in the 7 vertical direction between itself and the charger, and the charger cooling fan is disposed at an upper portion of the wind duct. Further, the fifth feature of the present invention is characterized in that the charger includes cooling fins on a surface fronting on the wind duct. [0015] According to the third to fifth characteristic features, it is possible to form an upward flow of air in the wind duct without resisting against the flow of air whose temperature has been raised. This flow of air becomes a cooling wind impinging upon the fins, whereby the charger can be cooled effectively, a small type cooling fan can be adopted, and a compacter system can be contrived. In addition, since the fins are not exposed to the outside, appearance is good. [0016] Besides, the sixth feature of the present invention is characterized in that the electrically driven vehicle includes a rear fender for covering an upper portion of the rear wheel, and an upper portion of the cooling fan is covered by the rear fender in plan view. According to the sixth characteristic feature, a wind exhaust port of the cooling fan is protected by the rear fender, and 8 cooling efficiency of the fan can be maintained. [0017] Further, the seventh feature of the present invention is characterized in that the electrically driven vehicle includes a down converter disposed at a rear portion of the vehicle body, the down converter is mounted on a vehicle body frame made of a light alloy, and is contained in a rear portion body cover. The eighth feature of the present invention is characterized in that the down converter is contained in a light metal made box including cooling fins extending in the front-rear direction of the vehicle body, at least on its surface making contact with the vehicle body frame. [0018] According to the seventh and eighth characteristic features, the down converter and its cooling fins can be formed by utilizing the space surrounded by the body cover at a rear portion of the vehicle body where the charger is not present. In addition, since the down converter is in contact with the vehicle body frame having high thermal conductivity, heat can be discharged effectively. Particularly, according to the eighth characteristic feature, cooling performance can be further enhanced by the cooling fins. 9 [0019] In order to attain the second object described above, the ninth feature of the present invention is characterized in that, in a battery device for an electrically driven vehicle which is a motor scooter type vehicle including a step floor at a lower portion on the front side of a seat, and a battery system including a battery unit assembled by integrating a plurality of batteries, the battery system being mounted under the step floor, cooling fans for cooling the battery unit are provided on at least one of the front and rear sides of a vehicle body. In addition, the tenth feature of the present invention is characterized in that one of the cooling fans to be provided on the rear portion side of the vehicle body is disposed on an upper portion of the battery unit. Further, the eleventh feature of the present invention is characterized in that one of the cooling fans to be provided on the front portion side of the vehicle body is connected to a front surface of the battery unit, and one of the cooling fans to be provided on the rear portion side of the vehicle body is connected to a rear surface of the battery unit through a duct. [0020] According to the ninth to eleventh characteristic 10 features, the cooling wind can be fed to the battery-device from the front side and from the rear side, so that a high cooling performance in total can be obtained even though the cooling fans are small in size. Therefore, the cooling fans can be made smaller in size, so that the degree of freedom in laying out the cooling fans is enhanced. Particularly according to the tenth characteristic feature, the space at a lower portion on the front side of the seat can be utilized effectively, and the cooling fans can be disposed by utilizing the space under the seat while securing the volume of the battery unit up to a length nearly equal to the front-rear length of the floor. [0021] In addition, the twelfth feature of the present invention is characterized in that the cooling fans on the front-rear side are of the same type. According to the twelfth characteristic feature, a reduction in cost and facility of parts management can be contrived through common use of the component parts. [0022] Besides, the thirteenth feature of the present invention is characterized in that the battery device includes a battery frame for holding the battery unit, 11 and the battery frame is provided with connecting means for connecting the battery frame to a vehicle body frame made of a light alloy. According to the thirteenth characteristic feature, the heat generated at the batteries is transmitted through the battery frame and the connecting means to the vehicle body frame which is high in thermal conductivity, so that efficiency of cooling the battery unit is further enhanced. [0023] In addition, the fourteenth feature of the present invention is characterized in that the battery unit is provided with passages for a cooling wind which are formed between the batteries, and the battery frame is provided with wind exhaust ports connected to the passages. According to the fourteenth characteristic feature, the cooling wind flows through the spaces between the batteries and is discharged to the outside through the wind exhaust ports, so that the batteries can be cooled nearly uniformly by the front and rear cooling fans. [0024] Besides, the fifteenth feature of the present invention is characterized in that the cooling fans have wind leading directions so set as to take in air from the 12 front side of the vehicle body and feed the cooling wind into the passages. According to the fifteenth characteristic feature, the running wind can be effectively taken in by the cooling fans during running of the vehicle, so the fan efficiency is enhanced. [0025] [Mode for Carrying Out the Invention] Now, one embodiment of the present invention will be described below referring to the drawings. 13 [Brief Description of the Drawings] [Fig. 1] A major part exploded perspective view from the right rear side of a motor cycle according to one embodiment of the present invention. [Fig. 2] A side view of a right rear portion of the motor cycle according to the embodiment of the present invention. [Fig. 3] A perspective view of a charger. [Fig. 4] A plan view, of the charger. [Fig. 5] A side view of the charger. [Fig. 6] A perspective view of a down converter. [Fig. 7] A side view of the down converter. [Fig. 8] A major part exploded left side view showing the structure of a rear portion of the -motor cycle according 14 to the embodiment of the present invention. [Fig. 9] A major part exploded perspective view from the rear side of the motor cycle according to the embodiment of the present invention. [Fig. 10] A side view of a motor scooter type vehicle on which the charger and the battery device and so on are mounted according to the embodiment of the present invention. [Fig. 11] A side view of a battery device according to one embodiment of the present invention. [Fig. 12] An enlarged side view of a major part of the battery device according to the embodiment of the present invention. [Fig. 13] A sectional view taken at position A-A of Fig. 1. [Fig. 14] An exploded plan view of a major part of a vehicle on which the battery device according to the embodiment of the present invention is mounted. [Fig. 15] 15 In the following description, the terms "front (forwards)", "rear (rearwards)", "upper (upwards)— and..lower (downwards)" mean the directions as viewed from the driver, and the front side Fr, the rear side Rr, the left side L and the right side R show positions with reference to the running direction of the vehicle. [0026] Fig. 10 is a side view of a motor cycle having a fitting mode of a charger or the like according to the present invention. The motor cycle 10 which is a motor scooter type vehicle includes a vehicle body frame 11, a front fork 12 fitted to a head pipe 11a of the vehicle body frame 11, a front wheel 13 fitted to the front fork 12, a handle 14 connected to the front fork 12, a power unit 15 vertically swingably fitted to a rear portion of 17 the vehicle body frame 11, a rear wheel 16 fitted to the power unit 15, a rear cushion unit 17 for hanging a rear end portion of the power unit 15 from the vehicle body frame 11, a storage box (luggage box) 18 fitted to a rear upper portion of the vehicle body frame 11, and a seat 19 disposed on the upper side of the storage box 18 and so fitted as to be openable and closable. A helmet and the like are contained in the luggage box 18. [0027] The vehicle body frame 11 is die-cast from a light alloy such as an aluminum alloy, with the head pipe 11a cast integrally. The power unit 15 is included of a motor 21 and a belt-type non-stage transmission 22 provided with a centrifugal clutch. The motor 21 includes a motor shaft 211 extending nearly horizontally in the vehicle width direction, and the rotation of the motor shaft 211 is transmitted to a shaft (rear axle) 161 of the rear wheel 16 through the belt-type non-stage transmission 22 and a speed reduction mechanism. As the motor 21, a three-phase brushless motor capable of producing a high output is desirably used. A controller (not shown) including a semiconductor switching element for control of power supply to the brushless motor may be provided at an end portion in the axial direction of the motor 21. 18 [0028] The vehicle body frame 11 is covered by a body cover 24. The body cover 24 includes a front cover 31 covering a front portion of the head pipe 11a, a leg shield 26 clamping the head pipe 11a, covering a rear portion of the front cover 31 and covering the front side of leg portions of the driver, a step floor (low floor type foot rest plate) 27 on which the feet of the driver are mounted, a left-right pair of floor side covers 28 extending downwards from outer edges of the step floor 27, an under cover 29 covering the space between the lower edges of the front side covers 28, a seat lower portion cover 36 covering a front portion of the lower periphery of the seat 19, a rear cover 32 covering a lower rear portion of the seat 19 and the upper side of the rear wheel 16, and a left-right pair of side covers 33. [0029] A battery device 35 is disposed under the step floor 27. The battery device 35 is supported on a portion (lower frame) 11L disposed under the step floor 27 and extending nearly horizontally in the front-rear direction of the vehicle body, by stays 355, 356 and a support shaft 35a which function as connecting means. The support shaft 35a is fitted coaxially with a pivot shaft of a 19 swing arm which fixes the power unit 15 to the vehicle body frame 11. The lower frame 11L is branched to left and right sides of the vehicle body, and the battery device 35 is disposed by utilizing the space between the branches. [0030] Fans 38, 39 for cooling the batteries are provided at a front portion and a rear portion of the battery device 35. The front fan 38 is provided on the direct front side of the battery device 35, whereas the rear fan 39 is provided in the vicinity of the rear end of an upper portion of the battery device 35. Particularly, the rear fan 39 is provided, with a duct 41 for feeding a cooling wind to each battery of the battery device 35. The fans 38 and 39 are equal in size, and since the battery device 35 is cooled by the two fans, a reduction in size of each individual fan can be contrived. The fan 39 made smaller in size can be contained by effectively utilizing the space on the lower side of the storage box 18. [0031] A charger 37 for charging the batteries of the battery device 35 is provided at a rear portion of the vehicle body. The charger 37 is hung from the vehicle 20 body frame 11 by a stay 42 on the side opposite to the side where the belt-type non-stage transmission 22 is disposed, namely, the right side of the vehicle body frame 11. A cooling fan 43 is provided at an upper portion of the charger 37. Disposition and size of the charger 37 are so set that the lowermost end thereof is located on the upper side of the rear axle 161 and that the charger 37 is contained within the front-rear length of the rear wheel 16 in side view. By such size and disposition, interference of the charger 37 with the motor 21 located on the front side of the rear wheel 16 can be obviated, a bank angle can be secured, and effective utilization of space can be achieved. [0032] A down converter 44 is mounted on a rear portion of the vehicle body frame 11, and a breaker 45 is mounted on the vehicle body frame 11 at a position on the upper side of the support shaft 35a. A charging plug 34 is led from the charger 37 into the storage box 18, and is hooked on a hook (not shown) provided in the storage box 18. An upper portion of the down converter 44 is covered by the rear cover 32. [0033] A seat catch 46 is provided at a rear upper portion 21 of the vehicle body frame 11, in correspondence with a hook 19a provided on the seat 19. A rear fender 47a is provided for the rear wheel 16, and a second rear fender 47b extending downwardly rearwards from the vehicle body frame 11 is provided in the outer periphery of the rear fender 47a. [0034] Fig. 3 is a perspective view of a charger, Fig. 4 is a plan view of the charger, and Fig. 5 is a side view (partially sectional) of the charger. In these figures, the charger 37 is included of a box-like main body 371 made of a light metal such as an aluminum alloy and a lid 372 made of a resin. The main body 371 is provided on its one surface (the surface on the opposite side of the lid 372) with cooling fins 373 integral with the main body 371. A stay 42 is fixed to the main body 371 by bolts 374, oppositely to the fins 373. The stay 42 is provided with fitting holes 375 for fitting to the vehicle body frame 11, and is three-dimensionally molded so as to form a wind duct 50 between itself and the charger 37. [0035] A cooling fan 43 provided at an upper portion of the charger 37 is so set as to take in air from the lower side and discharge the air to the upper side. With the 22 cooling fan 43 driven, air is taken in from the lower side into the wind duct 50, and passes through the wind duct 50 to the upper side. By the air flow (cooling airflow) CA, cooling performance of the fins 373 is further enhanced, and the main body 371 of the charger 37 is cooled effectively. [0036] Fig. 1 is a perspective view of a rear portion of a motor cycle 10 showing a mode of mounting the charger 37, and Fig. 2 is a side view of a rear portion of the same. In Fig. 1, the charger 37 is fixed to the vehicle body frame 11 by the stay 42 at a rather central portion of the vehicle body, and is fixed to the vehicle body frame 11 by a bracket 52 at a surface on the front side of the vehicle body. The cooling fan 43 provided at an upper portion of the charger 37 has a skirt 431 so formed as to take in air efficiently from the wind duct 50. [0037] The second rear fender 47b includes a portion RFD extending from the rear end side of the vehicle body to the front upper side of the vehicle body, and a portion RFH extending horizontally forwards therefrom. The horizontal portion RFH is set in such a position as to cover the upper side of a wind exhaust port of the 23 cooling fan 43 in plan view. By this, the wind exhaust port of the cooling fan 43 is protected. A down converter 44 mounted on a rear portion of the vehicle body frame 11 is covered by the second rear fender 47b on the rear side and part of the side surfaces thereof. [0038] As shown in Fig. 2, in the condition where the side covers 33 are fitted, an upper portion of the charger 37 and the cooling fan 43 are covered by the side cover 33. Therefore, of the charger 37, only the lower portion, namely, only a straight linear outer shape is exposed to the people"s eyes, so that there is provided a charger mounting structure which is not intricate but is simple in appearance notwithstanding it is exposed to the outside. [0039] Fig. 6 is a perspective view of the down converter 44, and Fig. 7 is a side view of the down converter. Similarly to the charger 37, a main body of the down converter 44 is contained in a box 441 cast from a light metal such as aluminum. The box 441 is provided with a lid 442 made of a resin. The box 441 is provided with air-cooling fins 443 extending on the front and rear sides and along a lower surface of the vehicle body. 24 [0040] Fig. 8 is a left side view of a rear portion of the vehicle body, and Fig. 9 is a perspective view of the rear portion of the vehicle body as viewed from the rear side. The down converter 44 is mounted on the rear portion of the vehicle body with the fins 443 in contact with the vehicle body frame 11. Heat generated in the down converter 44 is dissipated through the fins 443; in this case, particularly because the vehicle body frame having good thermal conductivity is in contact with the fins 443, the dissipation of the heat is further promoted. [0041] A support member 52 made of a high-strength material such as steel is provided astride a front portion of the down converter 44, and is fitted to the vehicle body frame 11 by bolts 53, 54. A plate 461 constituting the above-mentioned seat catch 46 is fixed to the support surface member 52. [0042] Thus, since the space formed at a rear portion of the vehicle body can be made most of as a storage space for the down converter 44, the down converter 44 can be provided with the cooling fins 443 which are broad in area. As a result, synergistically with the high heat- 25 dissipating effect of the vehicle body frame 11 made of a light metal, the down converter 44 can be air-cooled effectively. [0043] Fig. 11 is a side view of the battery device 35, Fig. 12 is an enlarged view of a major part of a side surface of the battery device 35, and Fig. 13 is a sectional view taken at position A-A of Fig. 11. In these figures, the battery device 35 contains 1.2 volt Ni-MH batteries 351. The batteries 351 are cylindrical in shape, and are contained in a metallic frame (battery frame) 352 in four high piles disposed in two rows and 15 rows in the vehicle width direction and the vehicle longitudinal direction. Namely, a total of 120 batteries 351 are contained, to constitute a battery unit capable of producing an output of 7 0 volts. [0044] Passages 353 by which cooling winds led in from the outside into the battery device 35 by the cooling fans 38 and 39 are distributed throughout the battery device 35 are formed between the batteries 351. On the other hand, the frame 352 is provided with wind exhaust ports 354 through which the cooling wind having recovered the heat from the batteries 351 by flowing through the passages 26 353 is discharged to the outside of the frame 352. The wind exhaust ports 354 are provided respectively at extension positions of the passages 353 between the batteries 351, but only a part thereof is shown in the drawings in order to avoid complicatedness of the drawings. [0045] Stays 355, 356 for fitting the battery device 35 to the lower frame 11L are provided respectively at a front portion and an intermediate upper portion of the frame 352. The stay 355 at the front portion is fixed to the frame 352 by bolts 355a, 355b. On the other hand, the stay 357 at the intermediate upper portion is fixed by bolts 356a, 356b to a cross plate 357 fixed to an upper portion of the frame 352, and is fixed to a side portion of the frame 352 by a bolt 356c. [0046] A boss portion 358 for passing therethrough the support shaft 35a for supporting the battery device 35 on the vehicle body frame 11 at a rather rear side position is provided at the tip end of a bracket 359 extending rearwardly upwards from a rear portion of the frame 352. [0047] In the above constitution, the cooling fans 38 and 27 39 take in air from the front side of the vehicle as indicated by arrows W, and the cooling winds are fed into the inside of the frame 352 directly from the front portion cooling fan 3 8 and through a duct 41 (which turns the wind direction) from the rear portion cooling fan 39. The cooling winds thus led in pass through the passages 353 between the batteries 351 to be fed to side portions of the frame 352, and are discharged to the outside through the wind exhaust ports 354. [0048] Thus, the cooling winds are fed from the front and rear sides of the battery device 35, and are distributed uniformly throughout the passages 353, so that heat is recovered uniformly from each of the batteries 351, and the temperature of the batteries 351 is maintained to be not more than a predetermined temperature. With the arrangement in which air is taken in from the front side of the vehicle by the cooling fans 38 and 39, a running wind can be effectively taken in during running, so that fan efficiency is enhanced. The cooling fans 38, 39 are preferably of the same type, since common use of the component parts is advantageous in view of a reduction in cost and management of the parts. [0049] 28 Fig. 14 is a plan view showing the condition where the battery device 35 is mounted on the vehicle body frame 11, and Fig. 15 is a rear view (view from the rear side of the vehicle body) of the same. In both figures, the battery device 35 is disposed between the lower frames 11L which are roughly U-shaped in cross section of the vehicle body. The stay 355 is fixed to top surfaces of the lower frames 11L by bolts 355c, and the stay 356 is fixed to the lower frames 11L by bolts 356d. The batteries 351 are connected to the lower frames 11L of the vehicle body made of a metal (light metal such as an aluminum alloy) through the stays 355, 356, whereby the heat generated is transmitted efficiently to the lower frames 11L, and the battery device 35 can be cooled efficiently. [0050] Incidentally, by utilizing the U-shape of the lower frames 11L, cables 48, 49 such as a control cable and a power source cable are laid in the inside of U-shaped grooves 11LU. As shown in Fig. 5, the top surfaces of the battery device 35 and the lower frames 11L are covered by the step floor 27, and both side surfaces of the lower frames 11L are covered by the floor side covers 28. [0051] 29 [Effects of the Invention] As is clear from the above description, according to the inventions as set forth in claims 1 to 8, the charger can be disposed with good weight balance with respect to the vehicle body, and the cooling fan which would be intricate due to wiring or the like is covered by the body cover, whereby appearance can be enhanced. In addition, according to the inventions as set forth in claims 3 to 6, the charger can be cooled effectively. [0052] Further, according to the inventions as set forth in claims 7 and 8, the down converter including the box provided with sufficiently large cooling fins can be mounted by effectively utilizing the space at the rear portion of the vehicle body. Particularly, together with the dissipation of heat through the vehicle body frame having high thermal conductivity, high cooling performance can be obtained. [0053] As is clear from the above description, according to the inventions as set forth in claims 9 to 15, it is possible to provide a battery device in which cooling winds are efficiently fed from the front and rear sides of the vehicle body to the batteries by the two cooling 30 fans. Therefore, the individual cooling fans can be made smaller in size, and the degree of freedom in laying out the cooling fans is enhanced. Particularly, according to the inventions as set forth in claims 2 and 3, the rear portion cooling fan is disposed on the upper side of the batteries, so that the space at a front lower portion of the seat can be utilized effectively. [0054] In addition, according to the invention as set forth in claim 12, the two cooling fans are of the same type, so that facilitation of parts management and a reduction in cost can be contrived. [0055] Besides, according to the invention as set forth in claim 13, the heat generated at the batteries can be efficiently diffused by utilization of the high thermal conductivity of the vehicle body frame, and enhancement of cooling efficiency can be contrived. [0056] In addition, according to the invention as set forth in claim 14, the cooling wind can be distributed throughout the spaces between the batteries. Besides, according to the invention as set forth in claim 15, running wind can be taken in, so that fan efficiency can be enhauced 31 [Description of Reference Numerals] 10 : motor cycle- 11 vehicle body frame; 12 32- front fork; 13: front wheel; 14: handle; 15: power unit; 16: rear wheel; 21: motor; 22: transmission; 33: side cover; 35: battery device; 37: charger; 43: cooling fan; 44: down converter; 38, 39: cooling fan; 41: duct; 351: battery; 352: battery frame; 354: wind exhaust port; 355, 356: stay (connecting means). We claim 1. An electrically driven vehicle comprising a transmission for transmitting power from a motor disposed on the front side of a rear wheel to said rear wheel, said transmission being disposed on one side of a vehicle body, a down converter and a step floor, said electrically driven vehicle characterized in that: a charger for charging of a plurality of batteries is disposed at a side portion of said vehicle body opposite to the side of said transmission; a charger cooling fan disposed at an upper portion of said charger; and a body cover comprising side cover portions whose lower end positions are so set as to cover side portions of said charger cooling fan. 2. An electronically driven vehicle as claimed in claim 1, wherein said motor extends in the width direction of said vehicle body with a motor shaft set nearly horizontally, and said charger has its lower end located on the upper side of a shaft of said rear wheel and is disposed so as to be contained within the front-rear length of said rear wheel. 3. An electronically driven vehicle as claimed in claim 1, wherein said charger cooling fan is so set as to take in air from the lower side and discharge the air to the upper side. 4. An electronically driven vehicle as claimed in claim 3, wherein said electrically driven vehicle comprises a stay for fitting said charger to said vehicle body; -33- said stay is so formed as to form one wall portion of a wind duct extending vertically on the rear side of said charger between said charger and said vehicle body; and said-charger cooling fan is disposed at an upper portion of said wind duct; 5. An electrically driven vehicle as claimed in claim 4, wherein said charger comprises cooling fins on a surface fronting on said wind duct. 6. An electrically driven vehicle as claimed in claim 3, wherein said electrically driven vehicle comprises a rear fender covering an upper portion of said rear wheel; and an upper portion of said cooling fan is covered by said rear fender in plan view. 7. An electrically driven vehicle as claimed in claim 1, wherein the down converter is disposed at a rear portion of said vehicle body and mounted on a vehicle body frame made of a light alloy and is contained in a rear portion body cover. 8. An electrically driven vehicle as claimed in claim 7, wherein said down converter is contained in a light metal made box comprising cooling fins extending in the front-rear direction of said vehicle body, at least at its surface making contact with said vehicle body frame. 9. An electrically driven vehicle as claimed in claim 1, wherein the step floor is at a lower portion on the front side of seat, and a battery ; system including a battery unit assembled by integrating a plurality of batteries, said battery system being mounted under said step floor; and -34- cooling fans for cooling said battery unit are provided on at least one of the front and rear sides of a vehicle body. 10. An electrically driven vehicle as claimed in claim 9, wherein said cooling fans to be provided on the rear portion side of said vehicle body is disposed on an upper portion of said battery unit. 11. An electrically driven vehicle as claimed in claim 10, wherein said cooling fans to be provided on the front portion side of said vehicle body are connected to a front surface of said battery unit; and said cooling fans which are provided on the rear portion side, of said vehicle body is connected to a rear surface of said battery unit through a duct. 12. An electrically driven vehicle as claimed in claim 9, wherein said cooling fans are of the same type. 13. An electrically driven vehicle as claimed in claim 9, wherein said battery system comprises a battery frame for holding said battery unit; and said battery frame is provided with connecting means for connecting said battery frame to a vehicle body frame made of a light alloy. 14. An electrically driven vehicle as claimed in claim 13, wherein said battery unit is provided with passages for a cooling wind which are formed between said batteries, and said battery frame is provided with wind exhaust ports connected to said passages. 15. An electrically driven vehicle as claimed in claim 9, wherein said cooling fans have wind leading directions so set as to take in air from the -35- front side of said vehicle body and feed said cooling wind into said passages. 16. An electrically driven vehicle substantially as herein described with reference to the accompanying drawings. Dated this 28th day of May, 2002. JAYANTA PAL] OF REMFRY & SAGAR ATTORNEY FOR THE APPLICANTS -36-

Documents:

474-mum-2002-abstract(20-12-2007).doc

474-mum-2002-abstract(20-12-2007).pdf

474-mum-2002-cancelled pages(20-12-2007).pdf

474-mum-2002-claims(granted)-(20-12-2007).doc

474-mum-2002-claims(granted)-(20-12-2007).pdf

474-mum-2002-correspondence(20-12-2007).pdf

474-mum-2002-correspondence(ipo)-(15-11-2007).pdf

474-mum-2002-drawing(28-05-2002).pdf

474-mum-2002-form 1(28-05-2002).pdf

474-mum-2002-form 18(07-04-2006).pdf

474-mum-2002-form 2(granted)-(20-12-2007).doc

474-mum-2002-form 2(granted)-(20-12-2007).pdf

474-mum-2002-form 3(04-05-2007).pdf

474-mum-2002-form 3(13-04-2004).pdf

474-mum-2002-form 3(14-08-2002).pdf

474-mum-2002-form 3(28-05-2002).pdf

474-mum-2002-form 5(04-05-2007).pdf

474-mum-2002-form 5(28-05-2002).pdf

474-mum-2002-petition under rule 138(07-05-2007).pdf

474-mum-2002-power of authority(04-05-2007).pdf

474-mum-2002-power of authority(26-07-2002).pdf

abstract1.jpg