Straddle electric vehicle

A straddle electric vehicle comprises a battery case accommodating a battery which is an electric power supply for an electric motor; an inverter which converts DC power stored in the battery into AC power and supplies the AC power to the electric motor; an air passage through which ram air is guided to an interior of a battery case and discharges air from the battery case; and a radiator for cooling a coolant used to cool the inverter using water or oil, wherein the radiator is placed forward relative to an air inlet of the air passage or within the air passage.

TECHNICAL FIELD

The present invention relates to a straddle vehicle such as an ATV (all terrain vehicle) or a motorcycle, and a straddle electric vehicle which drives by a driving power generated by an electric motor.

BACKGROUND ART

In recent years, a straddle electric vehicle which incorporates as a driving power source an electric motor activated by electric energy stored in a battery has been developed. In the straddle electric vehicle, to ensure the reliability of its operation, it is necessary to control the temperatures of electric components such as an electric motor, an inverter, and a battery. To this end, regarding the straddle electric vehicle, it is proposed that ram air be guided to the interior of a battery case accommodating the battery to cool the battery using air, and an air outlet provided in the battery case faces the inverter to directly apply the air discharged from the battery case to the inverter (see e.g., Patent Literature 1).

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

It is demanded that the battery be cooled with air while avoiding a situation in which moisture contained in the ram air enters the battery case, and thereby a problem arises in the battery and an electric circuit connected to the battery. A straddle electric vehicle of a sport type intended to attain a high motion capability, is required to provide an output and an instantaneous force which are greater than those of a conventional electric vehicle. Therefore, it is necessary to increase a current supplied to the electric motor. Under the circumstances, the inverter is likely to be cooled insufficiently only by the ram air and the air discharged from the battery case.

Accordingly, an object of the present invention is to provide a straddle electric vehicle which is capable of cooling a battery and other electric components with a simple structure and suitably suppressing occurrence of a problem in the battery or the like.

Solution to Problem

The present invention has been developed to achieve the above object. According to the present invention, there is provided a straddle electric vehicle which drives by a driving power generated by an electric motor, comprising: a battery case accommodating a battery which is an electric power supply for the electric motor; an inverter which converts DC power stored in the battery into AC power and supplies the AC power to the electric motor; an air passage through which ram air is guided to an interior of the battery case and discharges air from the battery case; and a radiator for cooling a coolant used to cool the inverter or the electric motor using water or oil, wherein the radiator is placed forward relative to an air inlet of the air passage or within the air passage.

In accordance with this configuration, since the electric motor or the inverter is cooled with water or oil, the electric motor or the inverter is cooled more effectively. In contrast, the battery is cooled with air. Therefore, it becomes possible to avoid that the cooling system mounted in the straddle electric vehicle becomes complex in configuration and increases in size. The radiator for cooling the coolant for the inverter is placed within the air passage through which the air flows or forward relative to the air inlet within the air passage. Since this air is the ram air, the coolant can be cooled well.

The radiator may be placed upstream of the battery case within the air passage.

In accordance with this configuration, the ram air is blown into the radiator, and therefore the coolant can be cooled well. In addition, the radiator serves as a filter to separate moisture from the ram air moving toward the battery case. Therefore, without a need to design a member constituting the air passage toward the battery case so that it has a very intricate shape, it becomes possible to reduce a possibility of ingress of moisture into the battery case. Furthermore, the radiator can be protected from the outside by the member constituting the air passage.

The straddle electric vehicle may comprise an air box which is attached to an upper portion of the battery case and constitutes a portion of the air passage, wherein an upper portion of the air box may be openable and closable, and the radiator may be placed inside the air box.

In accordance with this configuration, the coolant can be cooled by utilizing air for cooling the battery, and maintenance work for the radiator can be carried out more easily. In addition, the radiator can be protected from the outside by the air box.

The air passage may have an extended section which is extended downward, the radiator may be placed in the extended section, and the extended section may be provided with a drain hole at a lower end of the extended section.

In accordance with this configuration, the extended section can capture moisture. In association with the filtering effect of the radiator, a water separation capability can be further enhanced. The drain port provided at the lower end of the extended section can prevent moisture captured in the extended section from flowing to a downstream side.

The radiator may be placed downstream of the battery case within the air passage.

In accordance with this configuration, the battery can be cooled more effectively while cooling the coolant by utilizing air for cooling the battery. In addition, the radiator can be protected from outside by the member constituting the air passage.

Advantageous Effects of Invention

As should be appreciated from the above, in accordance with the present invention, it becomes possible to cool a battery and other electric components with a simple structure and suitably suppress the occurrence of problems in the battery or the like. The above and further objects, features and advantages of the present invention will more fully be apparent from the following detailed description of preferred embodiments with accompanying drawings.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Throughout the drawings, the same or corresponding components are designated by the same reference symbols and will not be described repeatedly in detail. The stated directions are referenced from the perspective of a rider riding in an electric motorcycle which is an exemplary straddle electric vehicle according to the embodiment of the present invention.

FIG. 1is a right side view of an electric motorcycle which is an exemplary straddle electric vehicle according to Embodiment 1 of the present invention. As shown inFIG. 1, the electric motorcycle1includes a front wheel2which is a driven wheel, a rear wheel3which is a drive wheel, a vehicle body frame4disposed between the front wheel2and the rear wheel3, and an electric motor5which is a driving power source for moving the electric motorcycle1. The electric motorcycle1of the present embodiment is not equipped with an internal combustion engine and is configured to rotate the rear wheel3by a driving power generated by the electric motor5. In the electric motorcycle1of the present embodiment, a driving power transmission mechanism24for transmitting a rotation of the electric motor5to the rear wheel3includes a transmission25.

The electric motorcycle1includes a motor unit case15including a motor accommodating section29accommodating the electric motor5and a transmission accommodating section30accommodating the transmission25such that the motor accommodating section29and the transmission accommodating section30are unitarily joined together. In other words, the motor unit case15accommodates the electric motor5and the transmission25. The electric motor (or motor accommodating section29) is positioned above the transmission25(or transmission accommodating section30). The motor unit case15is elongated in a direction in which the motor accommodating section29and the transmission accommodating section30are arranged. As a result, the motor unit case15is mounted in the electric motorcycle such that it extends vertically.

The motor accommodating section29is provided in the upper portion of the motor unit case15, while the transmission accommodating section30is provided in the lower portion of the motor unit case15. The bottom portion of the motor unit case15constitutes an oil pan27for reserving oil. The oil is used as a coolant for cooling the electric motor5and an inverter35and as a lubricant for lubricating sliding portions of the transmission25. The motor unit case15also accommodates an oil pump28which discharges the oil reserved in the oil pan27. The oil pump28is placed between the transmission25and the oil pan27in a vertical direction.

The front wheel2is rotatably mounted to the lower portion of a front fork6extending substantially vertically. A steering shaft7for steering the front wheel is coupled to the upper portion of the front fork6, and a handle8is attached to the upper portion of the steering shaft7.

The vehicle body frame4includes a head pipe11, a pair of right and left main frames12, and a pair of right and left sub-frames31. The steering shaft7is supported by the head pipe11such that the steering shaft7is rotatable. The main frames12are unitarily joined to the head pipe11such that the main frames12extend rearward and downward from the head pipe11. The main frames12include down frame members13extending substantially vertically downward from the head pipe11and lower frame members14extending substantially horizontally rearward from the lower ends of the down frame members13. The rear end portions of the lower frame members14are joined to the front portion of the transmission accommodating section30. The sub-frames31extend rearward and downward from a region in the vicinity of the head pipe11, above the main frames12. More specifically, the sub-frames31include first sub-frame members31aextending rearward from the upper end portions of the down frame members13, and second sub-frame members31bcoupling the first sub-frame members31ato the vertical intermediate portions of the down frame members13. The rear end portions of the first sub-frame members31aare joined to the upper portion of the motor accommodating section29. As described above, the motor unit case15is joined to the main frames12and the sub-frames31, and the motor unit case15is constructed as a portion of the vehicle body frame4.

A swing arm16is pivotally coupled to the motor unit case15. The swing arm16extends in a forward or rearward direction. The swing arm16is pivotally coupled at its front end portion to the rear portion of the motor unit case15and supports the rear wheel3by its rear end portion such that the rear wheel3is rotatable. The motor unit case15has a flange protruding rearward from the rear portion thereof. A pivot17around which the swing arm16is pivotable is oriented in a rightward or leftward direction so as to penetrate the flange. In this way, in the present embodiment, the motor unit case15serves as a swing arm bracket or a pivot frame for supporting the swing arm16such that the swing arm16is pivotable.

A link mechanism18which operates in response to the pivot motion of the swing arm16is provided between the lower portion of the swing arm16and the bottom portion (in the present embodiment, oil pan27) of the motor unit case15. The lower end portion of a rear suspension19is coupled to the link mechanism18such that the rear suspension19is pivotable. The upper end portion of the rear suspension19is coupled to the rear portion of the motor unit case15such that the rear suspension19is pivotable. In this way, the motor unit case15also serves as a fastening suspension bracket for mounting the end of the rear suspension19to the vehicle body frame4.

The motor unit case15is also joined to a seat frame20. The seat frame20extends rearward from the upper portion of the motor unit case15such that it is inclined upward. A seat9on which the rider and a passenger are seated in the forward or rearward direction is mounted to the seat frame20. The electric motorcycle is a straddle vehicle. The rider is seated on the seat9while straddling a vehicle body.

The electric motorcycle1incorporates a battery unit21as an electric power supply for the electric motor5. The battery unit21includes a battery22for storing DC power, and a battery case23accommodating the battery22. The battery case23is supported on the lower frame members14of the main frames12. The inverter35converts the DC power stored in the battery22into AC power. The electric motor5is activated by the AC power supplied from the inverter to generate the driving power for moving the vehicle body. The driving power generated by the electric motor5is transmitted to the rear wheel3via the driving power transmission mechanism24. This allows the rear wheel3to rotate. As a result, the electric motorcycle1can drive. As described above, the driving power transmission mechanism24includes the transmission25and a chain26. The transmission25changes the speed of the rotation of the output shaft of the electric motor5. The chain26transmits the rotation with the changed speed, to the rear wheel3.

The battery case23is placed between the front wheel2and the rear wheel3. More specifically, the battery case23is placed forward relative to the motor unit case15and rearward relative to the down frame members13of the main frames12. In other words, the electric motor5is placed rearward relative to the battery case23, and the transmission25is placed rearward relative to the battery case23. The battery case23is supported on the main frames12such that it is placed on the lower frame members14of the main frames12. In this structure, it is not necessary to increase the stiffness of the battery case23to an excessively high degree, as compared to a case where the battery case23is suspended from the vehicle body frame4. Furthermore, the pair of right and left sub-frames31are placed outward relative to the battery case23in a vehicle width direction. This allows the side portions of the battery case23to be protected by the sub-frames31.

The electric motorcycle1is provided with an air passage50which serves to guide ram air to the interior of the battery case23and discharge the air from the battery case23to the outside air. This allows the battery22accommodated in the battery case23to be cooled by the air. The outline of the structure relating to the air passage50will be described with reference toFIG. 1. An air box51is attached to the upper portion of the battery case23. An air intake duct52is connected to the front portion of the air box51. An air discharge duct53is connected to the rear portion of the air box51.

The front portion of the air box51is placed rearward relative to the head pipe11and close to the head pipe11in the forward or rearward direction. The air intake duct52extends forward from the front portion of the air box51and opens in its front end portion which is located forward relative to the head pipe11. The rear portion of the air box51covers the upper portion of the motor unit case15from above. The rear portion of the air box51is placed forward relative to the seat9and close to the seat9in the forward or rearward direction. An air discharge duct53extends rearward along the seat frame20from the rear portion of the air box51and is placed below the seat9. The air discharge duct53opens in its rear end portion which is located between the seat9at an upper side and the rear wheel3at a lower side. A cover member10is provided below the seat9, and the side portion of the air discharge duct53is covered with the cover member10, together with the seat frame20.

During the driving of the electric motorcycle1, the incoming ram air from the forward direction is taken into the air intake duct52. Then, the air flows into the air box51through the air intake duct52. Since the inner space of the air box51is in communication with the interior of the battery case23via the battery case air inlet duct54, the air flows from the air box51into the battery case23. Also, since the inner space of the battery case23is in communication with the air discharge duct53via the battery case air outlet duct55, the air flows from the battery case23into the air discharge duct53. Then, the air is discharged from the air discharge duct53to the outside air through an opening in its rear end portion.

FIG. 2is a conceptual view showing a configuration of a cooling system incorporated in the electric motorcycle1ofFIG. 1. InFIG. 2, thin lines indicate an air flow (i.e., air passage50through which the air flows), and bold lines indicate an oil flow (i.e., oil passage through which oil flows). As shown inFIG. 2, the electric motorcycle1includes as the cooling system for cooling the electric components, a configuration for cooling the battery22with air and a configuration for cooling the electric motor and the inverter with oil. Alternatively, the electric motor5and the inverter35may be cooled with water. In a further alternative, either one of the electric motor5and the inverter35may be cooled with oil or water, and the other of electric motor5and the inverter35may be cooled with air.

How the battery22is cooled with air will now be described. The electric motorcycle1is provided with an air passage which serves to guide ram air to the interior of the battery case23and discharge the air from the battery case23. The air passage includes the inner space of the air box51attached to the upper portion of the battery case23. More specifically, the air passage50includes a first passage section50awhich serves to take in the ram air from the outside air and deliver it to the interior of the air box51, a second passage section50bwhich serves to deliver the air from the interior of the air box51to the interior of the battery case23, and a third passage section50cwhich serves to deliver the air from the battery case23to the outside air. The air intake duct52constitutes the first passage section50a, the battery case air inlet duct54constitutes the second passage section50b, and the battery case air outlet duct55and the air discharge duct53constitute the third passage section50c. The electric motorcycle1of the present embodiment is provided with a bypass passage50dwhich communicates the inner space of the air box51with the third passage section50csuch that the battery case23is bypassed. The bypass passage50dwill be described along with the structure of the air box51, with reference toFIG. 3. The air discharged from the battery case23may be supplied to the inverter35which is an electric component required to be cooled particularly (see dotted line ofFIG. 2). This allows the inverter35to be cooled more effectively.

Next, how electric motor5and the inverter35are cooled using oil will be described. The electric motorcycle1includes the oil pan27and the oil pump28as described above, and a radiator36. The oil pump28is activated by, for example, the driving power generated by the electric motor5and discharges the oil reserved in the oil pan27. The discharged oil is cooled by heat exchange with the air outside the radiator36while flowing through the interior of the radiator36. The cooled oil is supplied to the electric motor5and the inverter35. The oil supplied to the inverter35raises its temperature by heat exchange with the inverter35and then is returned to the oil pan27. By comparison, the inverter35receives the oil and thereby is cooled. The oil supplied to the electric motor5raises its temperature by heat exchange with the electric motor5, and then is supplied to sliding sections of the transmission25accommodated in the motor unit case15by its own weight. The sliding sections of the transmission25are lubricated by the oil sent from the electric motor5. The oil supplied to the transmission25is returned to the oil pan27by its own weight.

As described above, in the present embodiment, since the electric motor5and the inverter35are cooled using oil, the electric motor5and the inverter35are cooled more effectively. Therefore, the temperature of the electric motor5and the temperature of the inverter35can be controlled properly, and reliability of the operation of these electric components can be improved. In addition, since the oil used for cooling is also used for lubrication, the lubricating system and the oil-cooling system can be simplified as a whole. Moreover, since the battery22is cooled using air, the layout of pipes for guiding the oil does not become complex, and the oil-cooling system and the air-cooling system can be configured simply.

The radiator36is placed within the air passage50. This allows the air flowing through the air passage50to be utilized as the air which is the coolant which exchanges heat with the oil. Furthermore, the radiator36can be protected by the members constituting the air passage50.

FIG. 3is a cross-sectional view of the battery case23and the air box51ofFIG. 1. As shown inFIG. 3, in the present embodiment, the radiator36is placed within the first passage section50aof the air passage50. In other words, the radiator36is placed upstream of the battery case23and the air box51. Since the radiator36is placed upstream of the battery case23, the ram air before heat exchange with the battery22can be applied to (blown to) the radiator36, so that the oil can be cooled well. This allows electric motor5and the inverter35to be cooled more effectively. In addition, the radiator serves as a filter or a separator for separating moisture from the ram air flowing toward the battery case23. This can reduce a possibility of ingress of moisture into the battery case23without designing the air intake duct52so that it is bent in an intricate shape to capture the moisture. In the present embodiment, since the radiator36is filled within the air intake duct52as shown inFIG. 3, it works as a filter effectively.

The air box51includes a front section61, a rear section62, a partition wall63, and a bottom wall64. The front section61of the air box51covers the upper portion of the battery case23from above. The rear section62is provided rearward relative to the front section61integrally with the front section61. The partition wall63defines an inner space61aof the front section61and an inner space62aof the rear section62along the forward or rearward direction. The bottom wall64has a bottom surface defining the inner space61aof the front section61. The bottom wall64serves as the upper wall of the battery case23, and also serves as the wall which vertically defines the inner space of the air box51(inner space61aof the front section61) and the inner space of the battery case23.

The front section61is provided with a ram air inlet61bto which the air intake duct52is connected and through which the ram air flows into the air box51. The battery case air inlet duct54has a periscope shape and is placed in the inner space61aof the front section61. The battery case air inlet duct54extends upward from the bottom wall64in the inner space61aof the front section61and is bent at its upper end portion to be oriented horizontally. The inlet of the battery case air inlet duct54is provided in the upper end portion thereof. Since the battery case air inlet duct54is configured and placed as described above, moisture stays on the bottom wall64even when moisture enters the inner space of the air box51. This can reduce a possibility that moisture in the air box51flows into the inlet of the battery case air inlet duct54. This allows the battery22to be cooled with the ram air while suitably protecting the battery22from moisture.

The battery case air outlet duct55extends rearward from the rear wall of the battery case23, is bent and then extends upward into the inner space of the rear section62. The battery case air outlet duct55opens in the upper end portion located in the inner space62aof the rear section62. The air discharge duct53covers the rear wall of the rear section62from the rear. The rear wall of the rear section62is provided with a communication port62bvia which the inner space62aof the rear section62is in communication with the air discharge duct53. This allows the battery case air outlet duct55to be in communication with the air discharge duct53via the inner space62aof the rear section62and the communication port62b.

The partition wall63has a through-hole63a. Because of this, the inner space61aof the front section61bypasses the inner space of the battery case23, is in communication with the through-hole63aand the inner space62aof the rear section62, and as a result, in communication with the air discharge duct53. The through-hole63aand the inner space62aof the rear section62constitute the above described bypass passage50d. Electric components70electrically connected to the battery22are accommodated in the inner space61aof the front section61. These electric components70are placed between the ram air inlet61bat a front side and the through-hole63aat a rear side.

In the above described structure, there can be formed an air flow moving from the ram air inlet61btoward the inlet of the battery case air inlet duct54and an air flow moving from the ram air inlet61btoward the through-hole63a. The latter air flow allows the electric components70to be cooled by utilizing the ram air. A lid65which is openable and closable is attached to the upper wall of the front section61. By opening the lid65, an operator can access the inner space61aof the front section61. The operator can easily carry out maintenance work of the electric components70.

As described above, in accordance with the present embodiment, the electric components70as well as the battery22can be suitably cooled by air. In addition, since the ram air utilized to cool the battery22and the electric components70is also used as a coolant in the radiator36, the configuration of the overall cooling system can be simplified. Moreover, since the radiator36serves as a filter, the battery22and the electric components70can be protected from the moisture contained in the ram air in the case where the ram air is utilized for cooling.

FIG. 4is a cross-sectional view of the battery case23and the air box51of an electric motorcycle101which is an exemplary straddle electric vehicle according to Embodiment 2 of the present invention. Hereinafter, differences between Embodiment 2 and Embodiment 1 will be mainly described.

As shown inFIG. 4, a radiator136is placed upstream of the battery case23, in the air passage50. In the present embodiment, the radiator136is placed in the inner space of the air box51, to be precise, the inner space61aof the front section61. The upper portion of the front section61can be opened and closed by the lid65. In the present embodiment, therefore, maintenance work for the radiator136can be easily carried out. To allow maintenance work to be carried out more easily, the inner space of the rear section62may be configured to be openable and closable, and the radiator136may be accommodated in the rear section62.

In the present embodiment, the radiator136is placed in the inner space of the front section61such that the radiator136faces the ram air inlet. This allows the radiator136to serve as a filter so that the battery22can be protected from moisture as in Embodiment 1.

FIG. 5is a cross-sectional view of the battery case23and the air box51of an electric motorcycle201which is an exemplary straddle electric vehicle according to Embodiment 3 of the present invention. Hereinafter, differences between Embodiment 3 and the above described embodiments will be mainly described.

As shown inFIG. 5, a radiator236is placed downstream of the battery case23, in the air passage50. In the present embodiment, the radiator236is accommodated in the air discharge duct53. Since the radiator236is placed downstream of the battery case23in this way, the battery22and the electric components70can be cooled more effectively while utilizing air for cooling the battery as a coolant for cooling the oil.

FIG. 6is a cross-sectional view of the battery case23and the air box51of an electric motorcycle301which is an exemplary straddle electric vehicle according to Embodiment 4 of the present invention. Hereinafter, differences between Embodiment 4 and the above described embodiments will be mainly described.

As shown inFIG. 6, an air passage350has an extended section350dwhich is extended downward. In the present embodiment, an air intake duct352has a downward protruding section352awhich partially protrudes downward, and the extended section350dis formed by the downward protruding section352a. Specifically, in the present embodiment, the extended section350dis located upstream of the battery case23, in the air passage350. This is merely exemplary, and the extended section350dmay be located downstream of the battery case23, in the air passage350.

A radiator336is placed in the extended section350d. The radiator336is vertically elongated, and partitions the air passage350in a direction different from a vertical direction, within the extended section350dwhich is extended downward. In the present embodiment, the extended section350dis formed in a region extending substantially in the forward or rearward direction, in the air intake duct352, and therefore, the radiator336partitions the air passage350substantially along the forward or rearward direction, along which the air passage350extends. This is merely exemplary. The direction in which the radiator336partitions the air passage350is suitably changed according to the direction in which the air passage extends, in a region in which the extended section is provided.

The lower end of the extended section350dis in communication with the outside via a drain port352bformed in the bottom wall of the downward protruding section352a.

In accordance with the present embodiment, since the radiator336is placed in the extended section350dwhich is formed by extending downward a portion of the air passage350, the radiator336serves as a filter and the extended section350dcan suitably capture moisture contained in the ram air. Thus, a water separation capability can be further enhanced. In addition, the moisture captured in the extended section350dcan be discharged to the outside through the drain port352bprovided at the lower portion of the extended section350a. This makes it possible to avoid a situation in which the captured moisture flows to a downstream side of the radiator (e.g., air box51and battery case23).

FIG. 7is a cross-sectional view of an electric motorcycle401which is an exemplary straddle electric vehicle according to Embodiment 5 of the present invention. Hereinafter, differences between Embodiment 5 and the above described embodiments will be mainly described.

As shown inFIG. 7, the front opening of an air intake duct452serves as an air inlet450xin the whole air passage450. The air inlet450xis an opening through which the ram air is taken into the air passage450. In the present embodiment, the air inlet450xis located in front of the head pipe11and is substantially as high as the head pipe11. The air inlet450xis placed within a front cowling471which is placed forward relative to the head pipe11and supports a wind shield472. A radiator436is fastened to the front cowling471or the main frame12, and placed forward relative to the air inlet450x. In particular, in the present embodiment, the radiator436faces the front side of the air inlet450xand is close to the air inlet450x. There is no member interposed between the radiator436and the air inlet450x. The radiator436placed in this way serves as a filter, and makes it possible to avoid a situation in which moisture contained in the ram air enters the air passage450. The radiator436provided in the front cowling471receives the ram air sufficiently. Since the air inlet450xis placed rearward relative to the radiator436, the ram air passes through the radiator436smoothly. Therefore, the oil can be cooled effectively in the radiator436placed in this way.

FIG. 8is a cross-sectional view of an electric motorcycle501which is an exemplary straddle electric vehicle according to Embodiment 6 of the present invention. Hereinafter, differences between Embodiment 6 and the above described embodiments will be mainly described.

As shown inFIG. 8, a radiator536of the present embodiment is placed forward relative to an air inlet550x. The radiator536faces the front side of the air inlet550xand is closer to the air inlet550x. There is no member interposed between the radiator536and the air inlet550x. The front opening of an air intake duct552serves as the air inlet550xof the whole air passage550. The air intake duct552extends downward from the front end portion of the air box51. The air inlet550xis located below the head pipe11, above the front wheel2and rearward relative to the front wheel2. The radiator536is fastened to a side cowling (not shown) or the main frame12and placed forward relative to the air inlet550x. In the present embodiment, as in Embodiment 5, the radiator536serves as a filter, and makes it possible to avoid a situation in which moisture contained in the ram air enters the air passage550. Since the radiator536receives the ram air sufficiently, and the ram air passes through the radiator536smoothly, the oil can be cooled effectively in the radiator536.

Although the electric motorcycle has been exemplarily described in the embodiments of the present invention, the present invention is applicable to other straddle vehicles such as an all terrain vehicle (ATV), or a three-wheeled vehicle. Although the vehicle which does not include an internal combustion engine and drives only by the driving power generated by an electric motor is exemplarily described as an electric vehicle, the present invention is also applicable to a hybrid vehicle including an internal combustion engine in addition to an electric moor.

INDUSTRIAL APPLICABILITY

The present invention has advantages that it becomes possible to cool a battery and other electric components with a simple structure and suitably suppress the occurrence of problems in the battery or the like, and is effectively applied to a straddle electric vehicle including a radiator and a battery case.