Saddle-type vehicle

Abstract

This saddle-type vehicle comprises: a seat (8) where an rider sits; a handle (2) gripped by the rider; a floor part (9) that is disposed between the handle (2) and the seat (8) and that forms a footrest board (9a) where the rider places their feet; a motor (30) that generates a driving force for vehicular travel; a battery (100) that stores power for driving the motor (30); and an inverter (33) that converts a direct current supplied by the battery (100) to an alternating current and supplies the alternating current to the motor (30). At least one of the inverter (33) and the battery (100) is a subfloor electrical component disposed below the floor part (9). The subfloor electrical component is disposed in a recessed structure (50) having an opening (53) facing the lower side of the vehicle.

Description

Technical Field

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[0001] The present invention relates to a straddle-type vehicle. This application claims priority based on Japanese Patent Application No. 2022-147790 filed in Japan on September 16, 2022, and incorporates its content herein.

Background Art

[0002] In recent years, efforts to achieve a low-carbon society or a decarbonized society have become active, and research and development on electrification technologies have been conducted in vehicles to reduce CO2 emissions and improve energy efficiency. For example, in a scooter-type straddle-type electric vehicle having a floor portion between a handle and a seat, there is one in which a PCU (Power control unit, an integrated unit of an inverter and a control device) is housed below a footboard of the floor portion (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional configuration, a concave storage portion that opens upward is formed on the upper surface of the floor portion, and a PCU (electrical component) is stored in this storage portion and closed with a floor board. By the way, for electrical components such as an inverter, a configuration capable of supplying running wind for heat dissipation is desirable. On the other hand, the floor portion of a scooter-type vehicle has a low ground clearance, and there is a risk of being submerged up to the floor portion during road ponding or the like. There is no mention in the above conventional technology about countermeasures for such points.

[0005] The present invention aims to ensure heat dissipation for electrical components located beneath the floor and to suppress water ingress into electrical components in a saddle-type vehicle having a floor section between the steering wheel and the seat. This will ultimately contribute to improving energy efficiency. [Means for solving the problem]

[0006] As a means of solving the above problems, an embodiment of the present invention has the following configuration. (1) A saddle-type vehicle according to an aspect of the present invention comprises a seat (8) on which an occupant sits, a handle (2) on which the occupant grips, a floor portion (9) positioned between the handle (2) and the seat (8) and forming a footrest surface (9a) on which the occupant places their feet, a motor (30) that generates driving force for vehicle operation, a battery (100) that stores power to drive the motor (30), and an inverter (33) that converts the DC current supplied by the battery (100) into AC current and supplies it to the motor (30), wherein at least one of the inverter (33) and the battery (100) is an underfloor electrical component positioned below the floor portion (9), and the underfloor electrical component is positioned within a concave structure (50) with an opening (53) facing downwards towards the vehicle. According to the saddle-type vehicle described in (1) above of the present invention, heavy core electrical components such as inverters or batteries are placed under the floor to lower the vehicle's center of gravity. Furthermore, by surrounding these underfloor electrical components with a concave structure that opens downwards towards the vehicle, airflow can be supplied to the underfloor electrical components while simultaneously ensuring an air reservoir within the concave structure to prevent water from entering the underfloor electrical components, even if the vehicle is submerged up to the floor.

[0007] (2) In the saddle-type vehicle described in (1) above, the underfloor electrical component comprises a case (32) for housing element components, the case (32) comprises a breathing section (35) that connects the inside and outside of the case, the concave structure (50) comprises an upper wall portion (51) located above the underfloor electrical component, and a peripheral wall portion (52) that extends from the outer circumference of the upper wall portion (51) toward the lower side of the vehicle and surrounds the front, rear and left and right sides of the underfloor electrical component, the peripheral wall portion (52) may extend below the breathing section (35). According to the saddle-type vehicle described in (2) above of the present invention, the case of the underfloor electrical components is equipped with a breathing section to provide a breathing function within the case, and the peripheral wall portion surrounding the underfloor electrical components in the concave structure extends below the breathing section. As a result, even if the vehicle is submerged in water up to the vicinity of the floor, it is possible to suppress water ingress into at least the breathing section, secure an air reservoir, and prevent water from entering the case of the underfloor electrical components.

[0008] (3) In the saddle-type vehicle described in (1) above, the lower end (t2) of the rear wall portion (52b) on the rear side of the concave structure (50) may be lower than the lower end (t1) of the other wall portion (52a). According to the saddle-type vehicle described in (3) above of the present invention, the area around the inverter-side terminals is protected from contact with foreign objects by a rear wall that is long on the lower side of the vehicle, while the other wall sections are made relatively short, thereby allowing airflow to easily reach the underfloor electrical components and improving the heat dissipation of the underfloor electrical components.

[0009] (4) In the saddle-type vehicle described in any one of the above paragraphs (1) to (3), the underfloor electrical component is the inverter (33), the motor (30) and the battery (100) are located further rear than the inverter (33), the inverter (33) has an inverter-side terminal (31) on the rear side of the vehicle, and wiring (60, 61) connecting the motor (30) and the battery (100) to the inverter (33) may be connected to the inverter-side terminal (31). According to the saddle-type vehicle described in (4) above of the present invention, by providing the inverter-side terminal on the rear side of the vehicle (the side closer to the motor and battery) of the inverter, the length of the wiring such as power supply lines connecting the motor and battery to the inverter can be shortened, thereby reducing costs and weight.

[0010] (5) In the saddle-type vehicle described in (4) above, the inverter (33) may be inclined so that the rear part is located higher than the front part. According to the saddle-type vehicle described in (5) above of the present invention, the inverter-side terminal located on the rear side of the vehicle is positioned at a high position, making it easier to connect the wiring and preventing flying stones and the like from the front and bottom of the vehicle from coming into contact with the inverter-side terminal.

[0011] (6) In the saddle-type vehicle described in (4) above, the inverter (33) may be provided with a heat sink (34) having a heat dissipation section (34a) on the lower side of the vehicle. According to the saddle-type vehicle described in (6) above of the present invention, the lower side of the inverter faces the opening of the concave structure, so by placing the heat dissipation part of the heat sink in this area, the heat of the inverter can be effectively dissipated by the airflow while driving.

[0012] (7) In the saddle-type vehicle described in (4) above, the inverter (33) is positioned between a pair of left and right body frame members (14), and the concave structure (50) may be fixed to the body frame members (14). According to the saddle-type vehicle described in (7) above of the present invention, the inverter can be easily supported by a pair of left and right body frame members while being protected by these left and right body frame members.

[0013] (8) The saddle-type vehicle described in (4) above further comprises a control device (322) for controlling the inverter (33), and the inverter (33) may be configured as a unit (320) integrated with the control device (322). According to the saddle-riding type vehicle described in (8) of the present invention, by integrating the inverter and the control device into a unit, it is possible to suppress the component arrangement space and simplify the support structure.

Effect of the Invention

[0014] According to an aspect of the present invention, in a saddle-riding type vehicle having a floor portion between a handle and a seat, it is possible to ensure the heat dissipation of electrical components arranged under the floor and suppress the immersion of electrical components in water.

Brief Description of the Drawings

[0015] [Figure 1] It is a left side view of a motorcycle in an embodiment of the present invention. [Figure 2] It is a left side view including a partial cross section showing the arrangement of the PCU in the floor portion of the motorcycle. [Figure 3] It is a perspective view including a partial cross section of the periphery of the PCU viewed from the upper left rear. [Figure 4] It is a rear view of FIG. 3 viewed from the rear side. [Figure 5] It is a block diagram showing the drive system of the motorcycle.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the directions such as front, rear, left, and right are the same as those in the vehicle described below unless otherwise specified. In the drawings used in the following description, at appropriate positions, an arrow FR indicating the front of the vehicle, an arrow LH indicating the left side of the vehicle, an arrow UP indicating the upper side of the vehicle, and a line CL indicating the center of the vehicle body in the left-right direction are shown.

[0017] <Vehicle as a Whole> Fig. 1 shows a scooter-type motorcycle 1 as an example of a saddle-riding type electric vehicle, which has a floor part (low floor part) 9 on which a passenger (driver) places their feet. The motorcycle 1 includes a front wheel 3 that is a steering wheel and a rear wheel 4 that is a drive wheel. The front wheel 3 is supported by a front fork 6 and can be steered by a bar handle (steering handle) 2. In the figure, reference numeral 2a denotes grip portions on both the left and right sides of the bar handle 2, and reference numeral 2b denotes a handle cover that covers the periphery of the bar handle 2 excluding the left and right grip portions 2a.

[0018] The rear wheel 4 is supported at the rear end portion of a swing arm 20 and can be driven by an electric motor 30. The front end portion of the swing arm 20 is connected to a vehicle body main body 11A including a vehicle body frame 11. The vehicle body main body 11A of the embodiment includes, in addition to the vehicle body frame 11 that supports the steering system components 5, other components fixedly supported on the vehicle body frame 11. The vehicle body main body 11A of the embodiment includes the vehicle body frame 11 and a drive unit 30A including the electric motor 30.

[0019] The drive unit 30A is fixedly supported on the vehicle body frame 11. The above-mentioned "fixedly supported" means being immovable in the supported state (the position is uniquely determined), which is a substantial "fixing". However, even if it is supported via an elastic member such as a spring or rubber (such as a rubber mount) and can be displaced, as long as it is configured to return to the original position by the elastic force, it shall be included in "fixedly supported".

[0020] The steering system components 5 including the bar handle 2, the front fork 6, and the front wheel 3 are supported on the front end portion of the vehicle body frame 11 so as to be steerable. The swing arm 20 and the rear wheel 4 are supported on the drive unit 30A fixedly supported on the lower portion of the vehicle body frame 11 so as to be swingable up and down. The periphery of the vehicle body frame 11 is covered by a vehicle body cover 25.

[0021] The motorcycle 1 comprises a floor section 9 that forms a footrest surface on which the rider, seated on the seat 8, rests their feet; a front body FB that extends in front of the floor section 9; and a rear body RB that extends behind the floor section 9. Above the floor section 9, a straddle space K1 is formed to make it easier for the rider to straddle the vehicle.

[0022] A seat 8, on which an occupant sits, is supported on the rear body RB. The lower front end of the seat 8 is connected to the vehicle body via a hinge shaft 8a that runs along the vehicle width direction (left-right direction). The seat 8 rotates up and down around the hinge shaft 8a, thereby opening and closing the upper part of the rear body RB. When the seat 8 is in the closed state (see Figure 1) with its seat surface approximately horizontal and the upper part of the rear body RB closed, an occupant can sit on the seat 8, and the battery compartment below the seat 8 is closed. In this state, the seat 8 can be locked. When the seat 8 rotates around the hinge shaft 8a and the seat surface is raised upward, opening the upper part of the rear body RB, an occupant can no longer sit on the seat 8, and the battery compartment below the seat 8 opens, allowing the battery 100 to be attached and detached.

[0023] The vehicle frame 11 is formed by joining multiple types of steel materials together by welding or other means. The vehicle frame 11 includes a head pipe 12 located at the front end, a down frame 13 extending downward from the head pipe 12, a pair of left and right lower frames 14 branching out from the lower part of the down frame 13 and extending to the rear, and a pair of left and right rear frames 15 extending upward and rearward from the rear of the left and right lower frames 14. The PCU 320, which will be described later, is positioned between the left and right lower frames 14.

[0024] The perimeter of the vehicle frame 11 is covered by a vehicle cover 25. The vehicle cover 25 includes a front cover 25a that covers the front of the vehicle frame 11 from the front, an inner cover 25b that covers the front of the vehicle frame 11 from the rear, a floor cover 25c that covers the lower part of the vehicle frame 11 from above, a rear center cover 25d that covers the rear of the vehicle frame 11 from the front, and a pair of left and right rear side covers 25e that cover the rear of the vehicle frame 11 from the left and right sides.

[0025] The front cover 25a and inner cover 25b constitute the front body cover 25f, which forms the outer surface of the front body FB. The front body cover 25f also serves as a leg shield, covering the front of the driver's legs. The upper surface of the floor cover 25c constitutes the floor step 9a. The floor step 9a forms a flat upper surface (footrest surface) over the entire width in the vehicle width direction, for example. The floor step 9a may have a center tunnel that rises upward on the inside in the vehicle width direction. The rear center cover 25d and left and right rear side covers 25e constitute the rear body cover 25g, which forms the outer surface of the rear body RB. The body cover 25, with the exception of the steering wheel cover 2b, is fixedly supported by the main body 11A.

[0026] <Drive Unit> The drive unit 30A includes an electric motor 30 that generates driving force for the motorcycle 1, a reduction mechanism 37 that reduces the driving force of the electric motor 30, and a unit case 40 that houses the electric motor 30 and the reduction mechanism 37.

[0027] The electric motor 30 is powered by the battery 100. The electric motor 30 has its drive shaft aligned with the vehicle width. The electric motor 30 includes a rotor that rotates integrally with the drive shaft and a stator that surrounds the outer circumference of the rotor and is fixed to the unit case 40 (neither of which are shown). The electric motor 30 is driven by variable speed control, for example, VVVF (variable voltage variable frequency). The electric motor 30 is controlled to change speed as if it had a continuously variable transmission, but is not limited to this. The electric motor 30 may also be controlled to change speed as if it had a stepped transmission.

[0028] The reduction gear 37 includes a small-diameter gear that is rotatably mounted integrally with the drive shaft of the electric motor 30, and a large-diameter gear that meshes with the small-diameter gear (neither of which are shown). The large-diameter gear is rotatably mounted integrally with the output shaft, which is located behind the motor drive shaft and parallel to the motor drive shaft. One axial end of the output shaft (for example, the left end) protrudes to the outside of the unit case 40, and this protruding portion and the rear wheel 4 are connected so as to be able to transmit power via a power transmission device, for example, using an endless belt or chain.

[0029] The driving force generated by the electric motor 30 is transmitted to the drive wheel (rear wheel 4) supported by the swing arm 20 to propel the motorcycle 1. For example, a rear fender 27 is supported at the rear end of the swing arm 20 via a fender support arm 26. For example, the lower end of a rear cushion 28 is connected to the rear end of the swing arm 20. The swing arm 20 and the rear cushion 28 together constitute a suspension system (rear suspension) that supports the rear wheel 4.

[0030] The unit case 40 is a structure made of, for example, an aluminum alloy, and has a plurality of fixing parts 45a, 45b, 45c attached to the vehicle body frame 11. The plurality of fixing parts 45a, 45b, 45c include, for example, a first fixing part 45a located at the front end of the case, and second and third fixing parts 45b, 45c located above and below the rear end of the case.

[0031] <Battery> Battery 100 is mounted below seat 8. Battery 100 is positioned so as to overlap with seat 8 in a plan view. Battery 100 comprises multiple (for example, two front and rear) unit batteries 101 and 102. The multiple unit batteries 101 and 102 have the same configuration as each other. Hereinafter, each unit battery 101 and 102 will be referred to as front battery 101 and rear battery 102, respectively.

[0032] The front and rear batteries 101 and 102 each have a rectangular cross-section (for example, roughly square) and are prism-shaped (rectangular parallelepiped) extending in the longitudinal direction. The front and rear batteries 101 and 102 are arranged with their front and rear edges aligned in the left-right direction. The front and rear batteries 101 and 102 are arranged in an upright position, tilted so that the higher they are in the longitudinal direction, the further back they are positioned. The front and rear batteries 101 and 102 are tilted parallel to each other and are arranged with a constant gap between their front and rear surfaces.

[0033] Battery 100 generates a predetermined high voltage (48-96V) by connecting the front and rear batteries 101 and 102 in series. The front and rear batteries 101 and 102 are each composed of rechargeable and dischargeable energy storage, such as lithium-ion batteries.

[0034] Referring to Figure 4, battery cables 61 extend from the positive and negative terminals of the front and rear batteries 101 and 102, respectively. Each battery cable 61 is connected to a PDU (Power Driver Unit) 321 via a junction box (distributor) 323 and a contactor (electromagnetic switch) 324. A three-phase cable 60 extends from the PDU 321, and this three-phase cable 60 is connected to the electric motor 30.

[0035] The front and rear batteries 101 and 102 are mobile batteries that can be attached to and removed from the vehicle body. The front and rear batteries 101 and 102 can be charged using an external charger 325, for example, when they are removed from the vehicle body or when they are mounted on the vehicle body. The front and rear batteries 101 and 102 can be used independently, for example, as mobile batteries to power external devices.

[0036] Below the battery 100, the drive unit 30A is positioned. The battery 100 is positioned so that at least a portion of it overlaps with the drive unit 30A in a plan view. The front battery 101 is positioned so that it is almost entirely within the front-to-rear width of the drive unit 30A, and the rear battery 102 is positioned so that its front part overlaps with the front battery 101 and the drive unit 30A in the front-to-rear direction. Although not shown in the illustration, the front and rear batteries 101, 102 and the drive unit 30A are positioned so that they overlap each other in the vehicle width direction. In a plan view, the front and rear batteries 101, 102 and the drive unit 30A are positioned to straddle the left-to-right center of the vehicle.

[0037] <Drive System> As shown in Figure 5, the PDU (Power Driver Unit) 321 and the ECU (Electric Control Unit) 322 constitute a single control unit, the PCU (Power control unit) 320. The PDU 321 is equipped with an inverter 33 that converts the DC current supplied by the battery 100 into AC current and supplies it to the electric motor 30. The PDU 321 controls the energization of the stator windings of the electric motor 30. The electric motor 30 performs power operation in accordance with the control by the PDU 321, driving the motorcycle 1. The operation of the PDU 321 is controlled by the ECU 322.

[0038] Power from battery 100 is supplied to the motor driver PDU 321 via contactor 324. The power from battery 100 is converted from DC to three-phase AC in the PDU 321 and then supplied to the electric motor 30, which is a three-phase AC motor. The output voltage from battery 100 is stepped down via DC-DC converter (electrical component, down regulator) 326 and used to charge the 12V sub-battery 327. The sub-battery 327 supplies power to general electrical components such as lighting, meters, smart units, and control system components such as the ECU 322. By installing the sub-battery 327, various electromagnetic locks and other functions can be operated even when battery 100 is removed.

[0039] Each of the front and rear batteries 101 and 102 includes BMUs (Battery Managing Units) 101a and 102a that monitor the charge / discharge status, temperature, etc. Information monitored by each BMU 101a and 102a is shared with the ECU 322 when the front and rear batteries 101 and 102 are mounted on the vehicle body. Output request information from the accelerator sensor 329 is input to the ECU 322. The ECU 322 drives and controls the electric motor 30 via the PDU 321 based on the input output request information.

[0040] For example, the ECU 322 regulates the charge and discharge of the battery 100 according to the state of the battery 100. For example, the ECU 322 controls the contactor 324 etc. to switch between power supply to the battery 100 and discharge from the battery 100.

[0041] <PCU Arrangement> Referring to FIGS. 1 to 4, the PCU 320 has a flat rectangular parallelepiped outer shape with a reduced vertical width. The PCU 320 is arranged inside the floor portion 9. The PCU 320 is arranged between the left and right lower frames 14. The entire PCU 320 is arranged above the lower ends of the left and right lower frames 14, suppressing contact with the ground surface. The PCU 320 is arranged inclined in a side view of the vehicle such that the rear part is positioned above the front part. An inverter side terminal block 31 is arranged at the rear part of the PCU 320. By raising the ground height of this inverter side terminal block 31, it is difficult for disturbances from the road surface to reach the inverter side terminal block 31, and it is easy to perform connection work to the inverter side terminal block 31. A three-phase cable 60 is connected to the inverter side terminal block 31, and a positive and negative battery cable 61 extending from the case side connection terminal 107 of the front and rear battery case 103 and led out below the case lower protrusion 122 is connected. Control system wiring 67 connected to the ECU 322 is connected to, for example, the right side surface of the PCU 320 via a connector 67a.

[0042] The drive unit 30A is positioned behind the PCU320. The drive unit 30A is positioned so that its lower part overlaps the floor section 9 in the vertical direction, and its upper part is positioned above the floor section 9. The PCU320 is positioned so that its entirety fits within the vertical width of the drive unit 30A. The lower end of the drive unit 30A is positioned below the lower end of the PCU320, but above the lower ends of the left and right lower frames 14, and does not protrude below the lower ends of the left and right lower frames 14.

[0043] Although not shown in the diagram, the PCU320 and the drive unit 30A are positioned so that their positions in the vehicle width direction overlap each other. In a plan view, the PCU320 and the drive unit 30A are positioned to straddle the left and right center of the vehicle.

[0044] The PCU320 is positioned forward of the central position CP between the front and rear wheels 3 and 4 in the longitudinal direction of the vehicle. The drive unit 30A is positioned behind the central position CP between the front and rear wheels 3 and 4. This results in a good weight balance of the control system components in the longitudinal direction of the vehicle. By positioning the PCU320 and drive unit 30A on the rear suspension springs, the unsprung weight is reduced and road-following ability is improved compared to, for example, positioning at least one of the PCU320 and drive unit 30A under the rear suspension springs.

[0045] The PCU320 includes an electrical case 32 made of, for example, an aluminum alloy. An inverter 33, which includes a bridge circuit and a smoothing capacitor, is housed inside the electrical case 32. The bridge circuit and smoothing capacitor are composed of multiple switching elements such as transistors. The lower part of the electrical case 32 is a heat sink 34, with multiple heat dissipation fins 34a protruding downwards. The upper surface of the electrical case 32 is provided with a breathing section (vent plug, breathing hole forming section) 35 that connects the inside and outside of the electrical case 32. The breathing section 35 has, for example, a labyrinth structure to prevent the ingress of water and foreign matter, but a check valve, a waterproof and breathable sheet, etc. may also be placed to prevent the ingress of water, etc. The inside of the electrical case 32 of the underfloor electrical components is an environment where temperature fluctuations are large and condensation is likely to occur, so the breathing section 35 is provided to allow humidity to be adjusted.

[0046] <Underfloor case> Referring to Figures 2 to 4, the PCU 320 is housed in an underfloor case (concave structure) 50 positioned with an opening 53 facing downwards towards the vehicle. The underfloor case 50 is, for example, a one-piece molded product made of synthetic resin, and comprises an upper wall portion 51 that is rectangular in plan view and located above the PCU 320, and peripheral wall portions 52 that extend downwards from the four outer edges of the upper wall portion 51 and surround the front, rear, left, and right sides of the PCU 320. The peripheral wall portion 52 comprises a front wall portion 52a, a rear wall portion 52b, and left and right side wall portions 52c, respectively, positioned on the front, rear, left, and right sides of the PCU 320. The outer edge of the upper wall portion 51 and the upper edge of the peripheral wall portion 52 are integrated and continuous with each other. Each wall portion of the peripheral edge is also integrated and continuous with each other. The underfloor case 50 forms a closed (sealed) housing space K2 except for the opening 53 facing downwards. Therefore, even if the motorcycle 1 is submerged up to the floor portion 9, an air pocket is formed inside the floor-under case 50 above the lower end of the peripheral wall portion 52, and water exposure to the PCU 320 is suppressed. In Figure 2, the symbol W1 indicates the water level when submerged.

[0047] The lower end height (vertical height from the ground surface to the lower end) of the peripheral wall 52 differs depending on the part. The highest lower end height of the peripheral wall 52 is the height Z1 of the lower end t1 of the front wall 52a, and the lowest lower end height of the peripheral wall 52 is the height Z2 of the lower end t2 of the rear wall 52b. By increasing the lower end height Z1 of the front wall 52a (shortening the front wall 52a), it is made easier to introduce airflow into the underfloor case 50. On the other hand, the lower end height Z1 of the front wall 52a is lower than the vertical height Z3 of the breathing section 35 of the PCU 320 from the ground surface. Therefore, even if the motorcycle 1 is submerged up to the floor section 9, the submersion of the breathing section 35 is suppressed, and water ingress into the electrical case 32 of the PCU 320 (water exposure to electrical components inside the electrical case 32) is suppressed.

[0048] The underfloor case 50 has an opening 53 at its bottom, allowing airflow to be drawn into the PCU 320 inside the electrical case 32. However, the opening of the underfloor case 50 downwards raises concerns about the PCU 320 being affected by external disturbances. In particular, it is undesirable for workers' fingers or tools to enter the area around the inverter-side terminal block 31 during vehicle maintenance. For this reason, it is conceivable to provide a separate cover for the inverter-side terminal block 31. However, in this embodiment, the lower end height Z2 of the rear wall portion 52b of the underfloor case 50 that is close to the inverter-side terminal block 31 is lowered (the rear wall portion 52b is lengthened), making it difficult for fingers or other objects to enter the area around the inverter-side terminal block 31, and as a result, the need for a separate cover is eliminated.

[0049] The rear wall portion 52b extends downward to the extent that it does not obstruct the airflow within the electrical case 32, but holes or notches may be provided in the rear wall portion 52b to allow airflow. The rear wall portion 52b is the rear-side wall portion of the peripheral wall portion 52 and is a wall portion that spans between the rear ends of the left and right side wall portions 52c. The normal direction of the rear wall portion 52b in a plan view is oriented in the front-rear direction, but it may partially be oriented in the left-right direction due to steps or other differences. If the rear wall portion 52b is curved, for example, the rear wall portion 52b is defined as the range in which the normal direction in a plan view is at an angle of approximately 45 degrees with respect to the front-rear direction.

[0050] Referring to Figures 3 and 4, the underfloor case 50 is fixedly supported by the left and right lower frames 14. In the example shown, the underfloor case 50 is supported by the left and right lower frames 14 via an under cover 55. The under cover 55 is a tray-shaped cover that covers the PCU 320 from below, and is, for example, a one-piece molded product made of synthetic resin. The under cover 55 has curved portions 55a on its left and right sides that are curved to follow the outer circumferential surfaces of the left and right lower frames 14, and these left and right curved portions 55a are fixedly supported by the left and right lower frames 14 with the left and right lower frames 14 resting on them from above. The under cover 55 is equipped with an air guide portion and an air exhaust portion for directing airflow.

[0051] Flanges 52d are formed at the lower ends of the left and right side walls 52c of the underfloor case 50, and these flanges 52d extend outward in the left-right direction. The underfloor case 50 is fixed to the under cover 55 with these flanges 52d in contact with the left and right sides of the under cover 55 from above, and the underfloor case 50 is fixed to the left and right lower frames 14 via the under cover 55.

[0052] Inside the floor-undercase 50, a support frame 56 is provided for supporting the PCU 320 on the left and right lower frames 14. The support frame 56 is, for example, a one-piece molded product made of steel plate, and comprises a rectangular upper wall portion 56a located above the PCU 320 in plan view, left and right side wall portions 56b that bend downward from the left and right sides of the upper wall portion 56a and are positioned on the left and right sides of the PCU 320, and left and right flanges 56c that bend outward in the left and right directions from the lower ends of the left and right side wall portions 56b.

[0053] The left and right flanges 56c are in contact from above with the bases 14a fixed to the upper surfaces of the left and right lower frames 14, and the left and right flanges 56c, and thus the support frame 56, are fixed to the left and right lower frames 14 by bolt fastening or the like. The fastening bosses 36 provided on the electrical case 32 of the PCU 320 are in contact from below with the upper wall portion 56a of the support frame 56 and are fixed by bolt fastening. The PCU 320 is fixedly supported by the upper wall portion 56a of the support frame 56 in a suspended state from above.

[0054] As described above, the motorcycle 1 of the above embodiment includes a seat 8 on which the rider sits, a handlebar 2 on which the rider grips, a floor section 9 positioned between the handlebar 2 and the seat 8 and forming a footrest surface (floor step 9a) on which the rider places their feet, an electric motor 30 that generates driving force for vehicle operation, a battery 100 that stores power to drive the electric motor 30, and an inverter 33 (PCU 320) that converts the DC current supplied by the battery 100 into AC current and supplies it to the electric motor 30. The inverter 33 is positioned below the floor step 9a and is located inside a floor-under case 50 with an opening 53 facing downwards towards the vehicle. This configuration lowers the vehicle's center of gravity by placing heavy core electrical components such as the inverter 33 under the floor. Furthermore, by surrounding these underfloor electrical components with an underfloor case 50 that opens downwards towards the vehicle, airflow can be supplied to the underfloor electrical components while ensuring an air reservoir within the underfloor case 50, even if the vehicle is submerged up to the floor 9, thus preventing water from entering the underfloor electrical components.

[0055] In the above-described motorcycle 1, the inverter 33 (PCU 320) includes an electrical case 32 for housing elemental components, the electrical case 32 includes a breathing section 35 that connects the inside and outside of the electrical case 32, and the underfloor case 50 includes an upper wall portion 51 located above the inverter 33 (PCU 320), and a peripheral wall portion 52 that extends from the outer periphery of the upper wall portion 51 toward the lower side of the vehicle and surrounds the front, rear, left and right sides of the underfloor electrical components, the peripheral wall portion 52 extends below the breathing section 35. With this configuration, the electrical case 32 of the underfloor electrical components is equipped with a breathing section 35 to provide a breathing function within the electrical case 32, while the peripheral wall portion 52 surrounding the underfloor electrical components in the underfloor case 50 extends below the breathing section 35. As a result, even if the vehicle is submerged in water up to the vicinity of the floor portion 9, water ingress into the breathing section 35 is suppressed, ensuring an air reservoir and preventing water from entering the electrical case 32 of the underfloor electrical components.

[0056] In the above-described motorcycle 1, the electric motor 30 and battery 100 are positioned further rear than the inverter 33 (PCU 320), and the inverter 33 (PCU 320) is equipped with an inverter-side terminal block 31 on the rear side of the vehicle, to which wiring (three-phase cable 60, battery cable 61) connecting the electric motor 30 and battery 100 to the inverter 33 is connected. With this configuration, by providing an inverter-side terminal block 31 on the rear side of the inverter 33 (the side closer to the electric motor 30 and battery 100), the length of wiring such as power supply lines connecting the electric motor 30 and battery 100 to the inverter 33 can be shortened, thereby reducing costs and weight.

[0057] In the above-described motorcycle 1, the peripheral wall portion 52 of the floor-under case 50 has a lower end t2 of the rear wall portion 52b on the vehicle side that is lower than the lower end t1 of the other wall portions (especially the front wall portion 52a). With this configuration, the area around the inverter-side terminal block 31 is protected from contact with foreign objects by a rear wall portion 52b that is long on the lower side of the vehicle, while the other wall portions are relatively short. This allows airflow to easily reach the underfloor electrical components while driving, improving the heat dissipation of the underfloor electrical components.

[0058] In the above-described motorcycle 1, the inverter 33 is positioned at an angle such that its rear end is located higher than its front end. With this configuration, the inverter-side terminal block 31, which is located on the rear side of the vehicle of the inverter 33, is positioned at a high position, making it easier to connect the wiring and preventing flying stones and other debris from the front and bottom of the vehicle from coming into contact with the inverter-side terminal block 31.

[0059] In the above-described motorcycle 1, the inverter 33 is equipped with a heat sink 34 having heat dissipation fins 34a on the lower side of the vehicle. With this configuration, the lower side of the inverter 33 faces the opening 53 of the underfloor case 50, so by placing the heat dissipation fins 34a of the heat sink 34 in this area, the heat dissipation of the inverter 33 can be effectively carried out by the airflow while driving.

[0060] In the above-described motorcycle 1, the inverter 33 is positioned between a pair of left and right body frame members (lower frame 14), and the underfloor case 50 is fixedly supported by the body frame members. With this configuration, the inverter 33 can be easily supported by a pair of left and right body frame members while being protected by these left and right body frame members.

[0061] In the above-described motorcycle 1, a control device (ECU322) for controlling the inverter 33 is provided, and the inverter 33 is configured as a unit (PCU320) integrated with the control device. This configuration allows for the integration of the inverter 33 and the control device into a single unit, thereby reducing the space required for component placement and simplifying the support structure.

[0062] The present invention is not limited to the embodiments described above. For example, while a PCU was given as an underfloor electrical component located below the floor, the invention is not limited to this. For example, the underfloor electrical component may be a battery, or a PDU (motor driver with at least an inverter) with the control unit (ECU) separated from the PCU, or it may be a configuration comprising at least a part of the PCU and battery. It may also be a configuration comprising a single battery instead of multiple batteries.

[0063] The present invention may also be applied to saddle-type vehicles other than motorcycles. The above-mentioned saddle-type vehicles include all vehicles on which the driver straddles the vehicle body, and include not only motorcycles (including mopeds), but also three-wheeled vehicles (including vehicles with one front wheel and two rear wheels, as well as vehicles with two front wheels and one rear wheel) or four-wheeled vehicles (such as four-wheeled buggies). The configuration in the above embodiment is just one example of the present invention, and various modifications are possible without departing from the spirit of the invention, such as replacing the components of the embodiment with well-known components. [Explanation of symbols]

[0064] 1. Motorcycle (saddle-type vehicle) 2-bar handlebars (handlebars) 8 sheets 9th floor section 9a Floor step (footrest surface) 14. Lower frame (vehicle frame component) 30 Electric motor (motor) 31 Inverter-side terminal block (inverter-side terminals) 32. Electrical component case (case) 33 Inverter 34 Heatsink 34a heat sink fins 35 Respiratory part 50 Floor-under case (concave structure) 51 Upper wall 52 Peripheral wall section 52a Front wall section (other wall sections) t1 bottom end 52b Rear wall t2 bottom end 60 Three-phase cable (wiring) 61 Battery cable (wiring) 100 batteries 101 Front Battery 102 Rear Battery 103 Battery Case 320 PCU (Integrated Unit) 322 ECU (Control Unit)

Claims

1. The seats (8) in which the occupants sit, The handle (2) held by the occupant, A floor portion (9) is positioned between the handle (2) and the seat (8) and forms a footrest surface (9a) on which the occupant places their feet, A motor (30) that generates driving force for vehicle movement, A battery (100) that stores power to drive the motor (30), An inverter (33) converts the DC current supplied by the battery (100) into AC current and supplies it to the motor (30), Equipped with, At least one of the inverter (33) and the battery (100) is an underfloor electrical component located below the floor portion (9), The aforementioned underfloor electrical components are arranged within a concave structure (50) with an opening (53) facing downwards towards the vehicle. The aforementioned underfloor electrical components include a case (32) for housing element components, The case (32) is equipped with a breathing section (35) that connects the inside and outside of the case, The concave structure (50) comprises an upper wall portion (51) located above the underfloor electrical components, and a peripheral wall portion (52) extending from the outer periphery of the upper wall portion (51) toward the lower side of the vehicle and surrounding the front, rear, left, and right sides of the underfloor electrical components. A saddle-type vehicle characterized in that the peripheral wall portion (52) extends below the breathing portion (35).

2. (delete)

3. The seats (8) in which the occupants sit, The handle (2) held by the occupant, A floor portion (9) is positioned between the handle (2) and the seat (8) and forms a footrest surface (9a) on which the occupant places their feet, A motor (30) that generates driving force for vehicle movement, A battery (100) that stores power to drive the motor (30), An inverter (33) converts the DC current supplied by the battery (100) into AC current and supplies it to the motor (30), Equipped with, At least one of the inverter (33) and the battery (100) is an underfloor electrical component located below the floor portion (9), The aforementioned underfloor electrical components are arranged within a concave structure (50) with an opening (53) facing downwards towards the vehicle. The saddle-type vehicle is characterized in that the peripheral wall portion (52) of the concave structure (50) has a lower end (t2) of the rear wall portion (52b) on the rear side of the vehicle that is lower than the lower end (t1) of the other wall portion (52a).

4. The seats (8) in which the occupants sit, The handle (2) held by the occupant, A floor portion (9) is positioned between the handle (2) and the seat (8) and forms a footrest surface (9a) on which the occupant places their feet, A motor (30) that generates driving force for vehicle movement, A battery (100) that stores power to drive the motor (30), An inverter (33) converts the DC current supplied by the battery (100) into AC current and supplies it to the motor (30), Equipped with, At least one of the inverter (33) and the battery (100) is an underfloor electrical component located below the floor portion (9), The aforementioned underfloor electrical components are arranged within a concave structure (50) with an opening (53) facing downwards towards the vehicle. The aforementioned underfloor electrical component is the inverter (33), The motor (30) and the battery (100) are positioned further rearward than the inverter (33). The inverter (33) is provided with an inverter-side terminal (31) on the rear side of the vehicle. A saddle-type vehicle characterized in that wiring (60, 61) connecting the motor (30) and the battery (100) to the inverter (33) is connected to the inverter-side terminal (31).

5. The saddle-type vehicle according to claim 4, characterized in that the inverter (33) is arranged at an inclination such that the rear part is located above the front part.

6. The saddle-type vehicle according to claim 4, characterized in that the inverter (33) is provided with a heat sink (34) having a heat dissipation section (34a) on the lower side of the vehicle.

7. The inverter (33) is positioned between a pair of left and right vehicle body frame members (14), The saddle-type vehicle according to claim 4, characterized in that the concave structure (50) is fixed to the vehicle body frame member (14).

8. The inverter (33) is further controlled by a control device (322), The saddle-type vehicle according to claim 4, characterized in that the inverter (33) is configured as a unit (320) integrated with the control device (322).

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