Electric vehicle

Abstract

This electric vehicle improves battery-related workability. The electric vehicle is provided with a battery in which battery modules (91A, 91B) including battery cells (92) are accommodated in a battery case (33), and a vehicle body frame (11), wherein the battery case (33) is fixed to the vehicle body frame (11), and the battery modules (91A, 91B) are detachably supported with respect to the battery case (33) from the lower side of the vehicle.

Description

Electric vehicle

[0001] The present invention relates to an electric vehicle.

[0002] In recent years, research and development on batteries such as secondary batteries that contribute to improving energy efficiency have been carried out to enable more people to access affordable, reliable, sustainable and advanced energy. Some electric vehicles such as straddle-type electric vehicles are equipped with a battery in which a battery module including a plurality of battery cells is housed in a battery case. The electric vehicle disclosed in Patent Document 1 describes a configuration in which a battery case main body is covered with a lid from above and fixed between left and right side frames.

[0003] Japanese Unexamined Patent Publication No. 2010-228660

[0004] Meanwhile, in the art related to batteries, an object is to improve workability such as detachability and maintainability of internal components such as battery modules. In conventional electric vehicles, since a footrest or the like is provided above the battery, the battery module cannot be easily removed, and it is necessary to lift the heavy battery module. In order to solve the above problem, the present application aims to improve battery-related workability, and thereby contributes to improving energy efficiency.

[0005] An electric vehicle comprising: a battery that houses a battery module including battery cells in a battery case; and a vehicle body frame, wherein the battery case is fixed to the vehicle body frame, and the battery module is detachably supported by the battery case from the lower side of the vehicle. The present invention provides such an electric vehicle.

[0006] According to the present invention, battery-related workability can be improved.

[0007] Figure 1 is a side view of a saddle-type electric vehicle according to an embodiment of the present invention. Figure 2 is a side view of the battery case along with its surrounding components. Figure 3 is a top view of the battery case along with its surrounding components. Figure 4 shows the battery case, rear wheel module, rear module, and front module. Figure 5 is a side view of the battery case. Figure 6 is a top view of the battery case. Figure 7 shows the battery case with the lid removed, viewed from below. Figure 8 is a cross-section of Figure 7 along the line Xa-Xa. Figure 9 is a cross-section of Figure 7 along the line Xb-Xb. Figure 10 is a cross-section of Figure 7 along the line Xc-Xc. Figure 11 shows the substrate support stay from below along with its surrounding components. Figure 12 is a perspective view of the battery module. Figure 13 is a cross-sectional view showing the second heat transfer member along with its surrounding components. Figure 14 shows the circuit configuration of the saddle-type electric vehicle.

[0008] Embodiments of the present invention will be described below with reference to the drawings. In the description, directions such as front, back, left, right, and up and down refer to directions relative to the vehicle body unless otherwise specified. In each figure, the symbol FR indicates the front of the vehicle body, the symbol UP indicates the top of the vehicle body, and the symbol LH indicates the left side of the vehicle body.

[0009] [Embodiment] [1. Overall Vehicle Configuration] Figure 1 is a side view of a saddle-type electric vehicle 10 according to an embodiment of the present invention. Hereinafter, the saddle-type electric vehicle 10 will be referred to as "electric vehicle 10". As shown in Figure 1, the electric vehicle 10 is an electric motorcycle comprising a body frame 11, a drive motor 13 that drives the rear wheel 12 which is the drive wheel, a pair of left and right front forks 15 that steerably support the front wheel 14, a swing arm 16 that supports the rear wheel 12, a rear suspension 17 that suspends the swing arm 16, a seat 18 on which the rider sits, a luggage box 19 located below the seat 18, a grab rail 20, and a body cover 21 that covers the body frame 11.

[0010] The electric vehicle 10 is a saddle-type vehicle in which the rider sits straddling the seat 18, and is a step-through type scooter vehicle having a low floor section 10f in the center of the front and rear of the vehicle body.

[0011] As shown in Figure 1, the vehicle frame 11 comprises a head pipe 31 located at the front of the vehicle, a front frame 32 extending downward from the head pipe 31, a battery case 33 which is part of the vehicle frame 11, and a rear frame 34 located at the rear of the vehicle. The head pipe 31 supports a pair of left and right front forks 15 and a steering handle 23 via a steering shaft 31s (Figure 3), thereby supporting the front wheels 14 so that they can be steered left and right.

[0012] The front frame 32 is a frame that connects the head pipe 31 and the battery case 33, and has a pair of left and right frames that extend from the head pipe 31 to the left and right and downward and rearward. The lower end of each front frame 32 is connected to the front of the battery case 33. Figure 2 is a side view of the battery case 33 along with its surrounding configuration. Figure 3 is a top view of the battery case 33 along with its surrounding configuration. In Figure 3, the pair of left and right front frames 32 are formed in a symmetrical shape with respect to the vehicle width center LC. Furthermore, since there is space between the pair of left and right front frames 32, it is possible to arrange control devices such as the ECU 214 (see Figure 14) that controls the electrical components of the electric vehicle 10, and lead-acid batteries 213 (see Figure 14) used as auxiliary batteries.

[0013] As shown in Figure 1, the head pipe 31 and front frame 32 are covered by the front cowl 21a and leg shield 21b, which are part of the vehicle body cover 21. The rear frame 34 is the frame at the rear of the vehicle body and supports the rear components of the vehicle body, including the seat 18 and luggage box 19. The rear frame 34 has a pair of left and right frames that extend upward from the rear of the battery case 33 with a gap between them. The pair of left and right rear frames 34 are formed in a symmetrical shape with respect to the vehicle width center LC. Each rear frame 34 is covered by a rear side cover 21c, which is part of the vehicle body cover 21.

[0014] As shown in Figures 2 and 3, the battery case 33 is a hollow, rectangular box shape that extends in the front-to-back and left-to-right directions and has a relatively thin profile, housing the drive battery 40 inside. The battery case 33 is made of a rigid material such as metal, and its high rigidity satisfies the strength required for the frame between the front frame 32 and the rear frame 34. The structure containing the drive battery 40 inside the battery case 33 can be referred to as a battery unit or battery.

[0015] In this configuration, the battery case 33 includes a rear suspension connecting portion 41 to which one end 17a of the rear suspension 17 is connected, a swing arm connecting portion 42 that supports the pivot shaft 36 of the swing arm 16, a pair of left and right rear frame connecting portions 43 to which parts of a pair of left and right rear frames 34 are connected, and a pair of left and right front frame connecting portions 44 to which parts of a pair of left and right front frames 32 are connected. In each figure, the axis lines of the one end 17a of the rear suspension 17 and the pivot shaft 36 are indicated by reference numerals.

[0016] The rear suspension connecting portion 41, the swingarm connecting portion 42, and the rear frame connecting portion 43 are provided at the rear of the battery case 33. The area of ​​the connecting structure Sr related to the rear of the battery case 33 is shown in Figures 2 and 3 and is referred to as the "rear battery case connecting structure Sr". The front frame connecting portion 44 is provided at the front of the battery case 33. The area of ​​the connecting structure Sf related to the front of the battery case 33 is shown in Figures 2 and 3 and is referred to as the "front battery case connecting structure Sf".

[0017] Figure 4 shows the state in which the swingarm 16, rear frame 34, and front frame 32 are separated from the swingarm connecting portion 42, rear frame connecting portion 43, and front frame connecting portion 44 of the battery case 33, respectively. In other words, the electric vehicle 10 is formed as a modular structure in which the rear wheel module 50, rear module 51, and front module 52, which consist of a unit swing-type drive system, can be separated from the battery case 33.

[0018] Each module 50, the rear module 51, and the front module 52 will now be described. As shown in Figure 4, the swing arm 16 is fitted with drive system components including the drive motor 13, rear wheel 12, and motor case cover 45, thereby forming the rear wheel module 50, which consists of a unit swing type drive system. The rear frame 34 is fitted with rear body components including the seat 18 and luggage box 19, thereby forming the rear module 51.

[0019] Furthermore, the front frame 32 is fitted with front body components such as the front wheel 14, front fork 15, head pipe 31, and steering system including the handlebars 23, thereby forming the front module 52.

[0020] [2. Battery Case 33] Figure 5 is a side view of the battery case 33. As shown in Figure 5, the battery case 33 has a case portion 61 that houses the drive battery 40 and a lid member 62 that closes the case portion 61 from below. As shown in Figure 5, the height of the case portion 61, Ha, is set to be greater than the height of the lid member 62, Hb. The interface Mk between the case portion 61 and the lid member 62 is parallel to the upper surface Mu and the lower surface Mq of the battery case 33. For the sake of explanation, the case portion 61 will be appropriately referred to as the upper battery case 61 and the lid member 62 as the lower battery case 62.

[0021] As shown in Figure 6, the upper battery case 61 has a pair of left and right side plates 61a extending in the front-rear direction with a gap between them, a front plate 61b bridging the front ends of the pair of left and right side plates 61a, and a rear plate 61c bridging the rear ends of the pair of left and right side plates 61a. Furthermore, the upper battery case 61 has a top plate 61d that covers the space enclosed by the pair of left and right side plates 61a, the front plate 61b, and the rear plate 61c from above, forming a rectangular box shape that opens downwards. These are formed from a rigid material such as metal, giving the upper battery case 61 high rigidity. For example, the side plates 61a extending linearly in the front-rear direction make the battery case 33 strong against loads acting in the front-rear direction, and the front plate 61b and rear plate 61c extending in the vehicle width direction make the battery case 33 strong against loads acting in the vehicle width direction.

[0022] Ribs extending in the front-to-back direction are formed on the upper surface of the top plate portion 61d at intervals in the vehicle width direction. These ribs increase the surface area of ​​the battery case 33, enabling efficient heat dissipation of the drive battery 40. Furthermore, these ribs increase the rigidity of the top plate portion 61d, thereby further increasing the rigidity of the battery case 33. As shown in Figure 7, female screw portions 63 for fixing the lower battery case 62 are formed at intervals on the left and right pair of side plates 61a, the front plate portion 61b, and the rear plate portion 61c. The number and position of the female screw portions 63 can be set as appropriate.

[0023] The lower battery case 62 is attached so as to cover the opening formed by the left and right side plates 61a, the front plate 61b, and the rear plate 61c from below. The lower battery case 62 is fixed to the upper battery case 61 by fastening a plurality of screw members 70 to each female screw portion 63 from below. The drive battery 40 inside the upper battery case 61 is surrounded by the upper battery case 61 and the top plate 61d, thus enabling proper protection of the drive battery 40. The lower battery case 62 is made of a rigid material such as metal, which contributes to improving the rigidity of the battery case 33.

[0024] As shown in Figure 6, the rear suspension connecting portion 41 is integrally provided with the top plate portion 61d, located at the top of the battery case 33 and in the center of the vehicle width direction of the battery case 33, and is a pair of left and right plate-like members that protrude upward from the top plate portion 61d. The pair of left and right members constituting the rear suspension connecting portion 41 have holes 41h (Figure 5) that penetrate in the vehicle width direction. One end 17a of the rear suspension 17 is rotatably supported in each hole 41h.

[0025] Furthermore, the rear suspension connection portion 41 has a first opening 61k1 on the left side in the vehicle width direction, where a pair of charge / discharge connectors 1A and 1B are arranged, which are connected to the drive battery 40 and to a power transmission cable extending from the charging port (not shown) of the drive battery 40. The voltage of the power conducting through charge / discharge connector 1A is lower than the voltage of the power conducting through charge / discharge connector 1B. On the other hand, the rear suspension connection portion 41 has a second opening 61k2 on the right side in the vehicle width direction, where a signal connector 1C and a low-voltage power connector 1D connected to a signal line extending from the drive battery 40 are arranged. In this embodiment, charge / discharge connectors 1A and 1B are arranged in the first opening 61k1 and signal connector 1C and low-voltage power connector 1D are arranged in the second opening 61k2, but the electrical components arranged in the first opening 61k1 and the second opening 61k2 can be appropriately selected. For example, a signal connector 1C and a low-voltage power connector 1D may be placed in the first opening 61k1, and charge / discharge connectors 1A and 1B may be placed in the second opening 61k2. Furthermore, the number, shape, and size of the first opening 61k1 and the second opening 61k2 can be changed as appropriate.

[0026] As shown in Figures 5 and 6, the swing arm connecting portion 42 is integrally provided with the rear plate portion 61c and is formed in a cylindrical shape that extends outward in the vehicle width direction from the vehicle width center LC behind the rear plate portion 61c. The swing arm connecting portion 42 is formed in a cylindrical shape for inserting the pivot shaft 36.

[0027] The rear frame connecting portion 43 integrally comprises a first rear frame connecting portion 43a and a second rear frame connecting portion 43b, which are integrally provided at the rear of a pair of left and right side plate portions 61a. The first rear frame connecting portion 43a, in the side view of the vehicle body shown in Figure 5, is located in front of the rear end surface Mr of the battery case 33, protrudes upward from the upper surface Mu of the battery case 33, and has a hole 43h at its protruding end that extends in the vehicle width direction. The second rear frame connecting portion 43b is located below the upper surface Mu of the battery case 33 and above the lower surface Mq, is provided closer to the rear end surface Mr of the battery case 33 than the first rear frame connecting portion 43a, and has a hole 43h that extends in the vehicle width direction.

[0028] The rear frame connecting portion 43, including the first and second rear frame connecting portions 43a and 43b, is formed as a plate-like shape that extends in the front-rear direction in a plan view, by extending from the rear upper surface to the rear rear surface of the side plate portion 61a and protruding around the side plate portion 61a. In this embodiment, the rear frame connecting portion 43 is formed as a triangular shape with corners at the top and rear in a side view of the vehicle body shown in Figure 5, with the top corner formed on the first rear frame connecting portion 43a and the rear corner formed on the swing arm connecting portion 42.

[0029] Although the rear frame connecting portion 43 is formed integrally with the side plate portion 61a, it may also be constructed separately from the side plate portion 61a and joined to the side plate portion 61a by a known joining method such as welding. In either case, the joining area between the rear frame connecting portion 43 and the side plate portion 61a is made a wide area that extends continuously from the rear upper surface to the rear back surface of the side plate portion 61a, as indicated by the symbol Hr in Figure 5, thereby ensuring a wide joining area between the rear frame connecting portion 43 and the battery case 33. This ensures the joining strength between the rear frame connecting portion 43 and the battery case 33, and efficiently distributes the load acting from the rear frame 34 to the battery case 33.

[0030] As shown in Figures 5 and 6, the rear plate portion 61c is provided with a push rod connecting portion 46 below the swing arm connecting portion 42, to which one end 65a of a push rod 65, which constitutes part of the link mechanism of the rear suspension 17, is connected. The push rod connecting portion 46 is integrally provided with the rear plate portion 61c and the swing arm connecting portion 42, is located behind the rear plate portion 61c, at or around the vehicle width center LC, and is formed in a cylindrical shape extending in the vehicle width direction.

[0031] The front frame connecting portion 44 has a first front frame connecting portion 44a and a second front frame connecting portion 44b, which are integrally provided on the front of a pair of left and right side plate portions 61a. The first front frame connecting portion 44a, in the side view of the vehicle body shown in Figure 5, protrudes upward above the upper surface Mu of the battery case 33 and behind the front end surface Mf, and has a hole 44h at its protruding end that extends in the vehicle width direction. The second front frame connecting portion 44b, in the side view of the vehicle body shown in Figure 5, protrudes forward below the upper surface Mu of the battery case 33 and above the lower surface Mq, and has a hole 44h at its protruding end that extends in the vehicle width direction. More specifically, the second front frame connecting portion 44b is formed above the interface surface Mk of the upper battery case 61 and the lower battery case 62, and below the upper surface Mu of the battery case 33, so that it is provided within the height-direction thickness Ha of the upper battery case 61.

[0032] The front frame connecting portion 44, including the first and second front frame connecting portions 44a and 44b, is formed as a plate-like shape that extends in the front-rear direction in a plan view, by extending continuously from the front upper surface to the front front of the side plate portion 61a and protruding around the side plate portion 61a. In this embodiment, the front frame connecting portion 44 is formed as a triangular shape with corners on the upper and front sides in a side view of the vehicle body shown in Figure 5, with the upper corner formed on the first front frame connecting portion 44a and the front corner formed on the second front frame connecting portion 44b.

[0033] Although the front frame connecting portion 44 is formed integrally with the side plate portion 61a, it may also be constructed separately from the side plate portion 61a and joined to the side plate portion 61a by a known joining method such as welding. In either case, the joining area between the front frame connecting portion 44 and the side plate portion 61a is made a wide area that extends continuously from the front upper surface to the front front surface of the side plate portion 61a, as indicated by the symbol Hf in Figure 5, thereby ensuring a wide joining area between the front frame connecting portion 44 and the battery case 33. This ensures the joining strength between the front frame connecting portion 44 and the battery case 33, and efficiently distributes the load acting from the front frame 32 to the battery case 33.

[0034] [3. Rear Battery Case Connection Structure Sr] As shown in Figure 2, the rear frame 34 has fastening parts 71 that are fastened to the first rear frame connection part 43a, including a first fastening part 71a fastened by a screw member 70 to the outside of the first rear frame connection part 43a in the vehicle width direction, and a second fastening part 71b fastened by a screw member 70 to the outside of the second rear frame connection part 43b in the vehicle width direction. As shown in Figures 2 and 3, the first rear frame connection part 43a and the second rear frame connection part 43b are provided spaced apart in the front-rear and up-down directions, thereby increasing the spacing between the two fastening parts 71a and 71b of the rear frame 34, while saving space in the front-rear and up-down directions for the placement of these fastening parts 71a and 71b, and achieving weight reduction of the fastening parts 71. In this embodiment, the rear frame 34 is fastened by a screw member 70, but the fastening method is not limited to a screw member.

[0035] In this embodiment, by connecting the left and right rear frames 34 to the outside in the vehicle width direction of each rear frame connecting portion 43, the internal space surrounded by the rear frames 34 can be expanded, improving the degree of freedom in arranging rear body components such as the rear suspension 17. In this embodiment, the rear frame 34 is formed as a truss structure, but it is not limited to a truss structure, and other suitable frame structures such as pipe forms or monocoque structures made of plate materials can be adopted.

[0036] As shown in Figures 2 and 3, the rear suspension 17 includes a suspension body 67, one end 17a of which is at the front end and connected to a rear suspension connecting portion 41; a link plate 68 to which the other end 17b of which is at the rear end of the suspension body 67 is connected; and a push rod 65, one end 65a of which is at the front end and connected to a push rod connecting portion 46, and the other end 65b of which is at the rear end and connected to the link plate 68. The link plate 68 is also called a rod link plate.

[0037] The suspension body 67 is positioned between the left and right rear frames 34, above the upper surface Mu of the battery case 33, and inclined towards the rear and upward at an angle close to the horizontal plane. In this configuration, the suspension body 67 is positioned in the center of the vehicle width of the battery case 33, but is not limited to the center of the vehicle width; it may also be positioned around the center of the vehicle width (for example, at a position offset to either side of the vehicle width from the center of the vehicle width).

[0038] As shown in Figure 2, the rear suspension 17 is positioned so that it overlaps with the rear frame 34 in a side view of the vehicle body. This allows the rear frame 34 to function as a guard member that protects the rear suspension 17 from the outside in the width direction of the vehicle. As a result, it is possible to suppress situations in which flying debris from the side of the vehicle body affects the rear suspension 17, and for example, water exposure and dirt on the rear suspension 17 can be reduced.

[0039] Furthermore, the second rear frame connecting portion 43b, the swing arm connecting portion 42, and the push rod connecting portion 46 are located below the upper surface Mu of the battery case 33, above the lower surface Mq, and behind the rear end surface Mr, and are close to each other in the vertical direction. More specifically, the swing arm connecting portion 42 is located within the height-direction thickness Ha of the upper battery case 61 at the same height as, or within a range that can be considered the same as, the upper surface Mu of the battery case 33, and the push rod connecting portion 46 is located within the height-direction thickness Ha of the upper battery case 61 at the same height as, or within a range that can be considered the same as, the interface surface Mk between the upper battery case 61 and the lid portion 62 of the battery case 33. Therefore, the swing arm connecting portion 42 and the push rod connecting portion 46 are provided within the height-direction thickness Ha of the upper battery case 61. As a result, the battery case 33 can suppress the scattering of moisture and other debris from the front and below of the vehicle body to the second rear frame connecting portion 43b, the swing arm connecting portion 42, the push rod connecting portion 46, and their surroundings. Furthermore, the swingarm 16 and push rod 65 can be compactly arranged vertically in the space behind the battery case 33.

[0040] [4. Battery Case Front Connection Structure Sf] As shown in Figure 2, the left and right pair of front frames 32 have fastening parts 81 that are fastened to the first front frame connection part 44a of the battery case 33. These fastening parts 81 include a first fastening part 81a fastened from the outside by a screw member 80 to the inside of the first front frame connection part 44a in the vehicle width direction, and a second fastening part 81b fastened from the outside by a screw member 80 to the inside of the second front frame connection part 44b in the vehicle width direction. The first front frame connection part 44a and the second front frame connection part 44b are provided spaced apart in the front-rear and up-down directions. This allows for increased spacing between the two fastening parts 81a and 81b of the front frame 32, while also saving space in the front-rear and up-down directions for the placement of these fastening parts 81a and 81b, and achieving weight reduction of the fastening parts 81. In this embodiment, the front frame 32 is fastened by a screw member 80, but the fastening method is not limited to a screw member.

[0041] In this embodiment, by connecting the left and right front frames 32 to the inside in the vehicle width direction of each front frame connecting portion 44a, the outward protrusion of the front frames 32 in the vehicle width direction is suppressed, and the vehicle width can be made more compact. Each front frame 32 is formed in a frame shape that widens in the front-rear direction as it moves outward in the vehicle width direction, as shown in the plan view in Figure 3. This ensures a large contact area between the front frame 32 and the front plate-shaped member including the front frame connecting portion 44, and thus ensures high connection strength.

[0042] Furthermore, as shown in Figure 4, the front frame 32 of this embodiment has a reinforcing rib structure in the range from the upper and lower intermediate portion to the first and second fastening portions 81a and 81b, thereby increasing frame strength while reducing weight. However, the configuration is not limited to having a reinforcing rib structure, and any appropriate frame structure can be adopted.

[0043] [5. Battery Structure] [5.1 Internal Structure of Battery Case 33] Figure 7 is a view of the battery case 33 from below with the lower battery case 62 removed. As shown in Figure 7, the battery case 33 has a shape in which the length in the front-to-back direction is longer than the length in the left-to-right direction. The upper battery case 61 of the battery case 33 is divided into three chambers C1, C2, and C3 in the front-to-back direction, which is the longitudinal direction, by two partition walls 61w1 and 61w2. As shown in Figure 7, the battery modules 91 that constitute the drive battery 40 are arranged in the two front chambers C1 and C2, respectively. The rear chamber C3 houses the substrate support stays 61s that extend in the left-to-right direction and the component mounting substrate 96, etc. The component mounting substrate 96 has a transformer 95 mounted on it and extends in the left-to-right direction, which is the short direction of the battery case 33. The substrate support stay 61s is fastened to the area corresponding to chamber C3 inside the case portion 61 by a plurality of fastening members 103, and the component mounting substrate 96 is fastened below the substrate support stay 61s by a plurality of fastening members 104.

[0044] The battery modules 91 disposed in the respective chambers C1 and C2 are identical modules, and the fixing structure to the battery case 33 is also identical. In the following description, the respective battery modules 91 are referred to as battery modules 91A and 91B. Note that the two front chambers C1 and C2 are an example of the "battery module housing area" in the present disclosure, and the rear chamber C3 is an example of the "transformer housing area" in the present disclosure.

[0045] Below the battery modules 91A and 91B, a pair of connection busbars 100 that electrically connect the battery modules 91A and 91B and the component mounting board 96 are disposed. Among the two battery modules 91A and 91B, the connection busbars 100 are disposed below the battery module 91B adjacent to the component mounting board 96 at intervals in the left-right direction. Each connection busbar 100 is a plate-shaped conductive member extending linearly in the front-rear direction, and is electrically and physically connected to the positive electrode and negative electrode of each battery module 91A, 91B by a fastening member 101 from below. Each connection busbar 100 is formed of, for example, a metal plate. The rear end of each connection busbar 100 is connected to a respective plate-shaped connection member 97. The connection member 97 has a connection portion 97a connected to the charge / discharge connectors 1A, 1B and a connection portion 97b connected to the component mounting board 96, and is electrically connected to the charge / discharge connectors 1A, 1B and the component mounting board 96 via these connection portions 97a, 97b, and is also electrically connected to the transformer 95.

[0046] Since each connection busbar 100 is disposed below the battery module 91B, access from below is easy. In addition, by removing the fastening member 101, each connection busbar 100 can be easily removed. Furthermore, since each connection busbar 100 has the same shape, errors during attachment can be prevented. Note that the shape and arrangement position of each connection busbar 100 may be changed as appropriate. In addition, the connection structure of the connection busbars 100 may be appropriately changed within a range in which the connection busbars 100 can be attached and detached from below.

[0047] The battery modules 91A and 91B include a plurality of battery cells 92, cell holders 93 that retain each battery cell 92, and a battery module substrate 94 (FIG. 12) that electrically connects each battery cell 92 on the upper surface side of each battery cell 92. As shown in FIG. 7, the cell holder 93 has cylindrical cell accommodating portions 93a that respectively accommodate the battery cells 92, and holds each battery cell 92 in a planar manner with their axial directions aligned in the vertical direction. The cell accommodating portions 93a are arranged at intervals in the front-rear direction and the left-right direction, and the respective battery cells 92 are squarely arranged in a matrix of 7 rows by 4 columns.

[0048] The square arrangement is a method of evenly arranging the battery cells 92 in a square shape, and is also referred to as a square grid arrangement. Compared with a case where, for example, the battery cells 92 are arranged in a hexagonal close-packed structure, a larger interval can be secured between the battery cells 92, so that the transfer of heat between adjacent battery cells 92 can be suppressed. The cell holder 93 is formed with a plurality of insertion holes 93b penetrating in the vertical direction at intervals in the front-rear and left-right directions. These insertion holes 93b have a smaller diameter than the cell accommodating portions 93a, and are formed between the cell accommodating portions 93a when viewed in the axial direction of the insertion holes 93b. More specifically, the insertion hole 93b is formed between four squarely arranged cell accommodating portions 93a. Compared with a case where, for example, the battery cells 92 are arranged in a hexagonal close-packed structure, a larger interval can be secured between the battery cells 92, so it becomes easier to secure a space for arranging the insertion holes 93b.

[0049] Fastening members 102 are inserted from below into some of these through holes 93b. The cell holder 93 is fixed to the upper battery case 61 by fastening the fastening members 102 to the upper battery case 61. Figures 8 and 9 show cross-sections of the lower battery case 62 attached to the upper battery case 61. Figure 8 shows the cross-section Xa-Xa in Figure 7. As shown in Figure 8, the upper battery case 61 has a plurality of protrusions 61t that protrude downward from the top plate portion 61d. These protrusions 61t are inserted into different through holes 93b of the cell holder 93, and the fastening members 102 are fastened to the protrusions 61t from below the cell holder 93. In this configuration, as shown in Figure 8, an upper contact portion 93c that abuts the lower surface of the protruding portion 61t via a washer w1 and a lower contact portion 93d that abuts the head of the fastening member 102 via a washer w2 are provided inside the insertion hole 93b. The cell holder 93 is fixed to the upper battery case 61 by fastening the fastening member 102 to the protruding portion 61t via the washer w2, the lower contact portion 93d, the upper contact portion 93c, and the washer w1. Note that the fixing structure in Figure 8 is just one example, and the fixing structure may be modified as appropriate, within the range of fixing the cell holder 93 from below and being removable.

[0050] Figure 9 shows the cross-section Xb-Xb in Figure 7. As shown in Figure 9, the upper battery case 61 has multiple protrusions 61t at positions different from the protrusions 61t shown in Figure 8. These protrusions 61t are inserted into different insertion holes 93b of the cell holder 93, and the cell holder 93 is fixed to the upper battery case 61 by fastening members 102 to each of the protrusions 61t from below the cell holder 93. In this way, the battery modules 91A and 91B, including the cell holder 93, can be fixed to the upper battery case 61 by the simple operation of fastening the fastening members 102 from below. Furthermore, the battery modules 91A and 91B can be easily removed from the upper battery case 61 by removing the fastening members 102.

[0051] The positions and number of fastening members 102 and protrusions 61t may be changed as appropriate. Furthermore, the fixing structure in Figure 9 may also be modified as appropriate, within the range of fixing the cell holder 93 from below and allowing for removal.

[0052] In this configuration, by removing the lower battery case 62 of the battery case 33, the space created beneath the vehicle body can be used to easily attach, detach, and access the battery modules 91A, 91B and the connecting busbar 100. Although Figure 7 illustrates a case where each cell holder 93 has the same rectangular shape as the inner shape of each chamber C1, C2, the cell holder 93 can be made smaller or have a shape other than rectangular. Furthermore, the connection structure to the upper battery case 61 can be shared even with cell holders 93 of different sizes and shapes. Therefore, the structure is designed to accommodate changes in the size of the battery modules 91A, 91B, i.e., changes in battery capacity or specifications.

[0053] Furthermore, in this configuration, the battery modules 91A and 91B in each chamber C1 and C2 are connected in parallel via the connecting busbar 100, and each battery module 91A and 91B is connected to the transformer 95. Therefore, even if a battery module 91A or 91B is placed in only one of the chambers C1 or C2, that battery module 91A or 91B can be connected to the transformer 95. Thus, the electric vehicle 10 of this embodiment can accommodate both a configuration with two battery modules 91A and 91B, and a configuration with only one of them. In other words, the battery includes a battery case 33 having multiple chambers C1 and C2 capable of housing battery modules 91, and regardless of whether there are chambers C1 and C2 that do not house battery modules 91, the power of the battery modules 91 housed in the chambers can be output to the outside of the battery.

[0054] When only the battery module 91A in chamber C1 is installed, the power from the battery module 91A is output to the component mounting board 96 and the charge / discharge connectors 1A and 1B via the connection part 97. When only the battery module 91B in chamber C2 is installed, the power from the battery module 91B is output to the component mounting board 96 and the charge / discharge connectors 1A and 1B via the connection busbar 100 and the connection part 97. When using only one of the battery modules 91A or 91B, installing the battery module 91A only in chamber C1 eliminates the need for the connection busbar 100, thus reducing the number of components.

[0055] In this configuration, as shown in Figure 5, the height of the upper battery case 61, Ha, is greater than the height of the lower battery case 62, Hb. Furthermore, as shown in Figures 8 and 9, in a cross-sectional view along the vehicle width, the cross-sectional area of ​​the upper battery case 61 is greater than the cross-sectional area of ​​the lower battery case 62. As a result, the rigidity of the upper battery case 61, to which the battery modules 91A and 91B are fixed, can be more effectively increased than that of the lower battery case 62.

[0056] [5.2 Component Mounting Board 96 and its Peripheral Structure] Figure 10 is a diagram showing the Xc-Xc cross-section of Figure 7. As shown in Figure 10, a board support stay 61s extending in the left-right direction is fixed to the rear compartment C3 of the upper battery case 61, and the component mounting board 96 is supported by this board support stay 61s. The component mounting board 96 extends in the left-right direction, which is the shorter direction of the battery case 33, and electronic components including a transformer 95 and a capacitor 95a are mounted on the upper surface of the board which has a wiring pattern for signal lines. On the right side of the component mounting board 96, which is one of the left and right sides, a connection part 97 is provided that is connected to a connection bus bar 100, and on the left side, which is the other of the left and right sides, the transformer coil 95b of the transformer 95 is arranged.

[0057] The transformer 95 is not particularly limited in its configuration or application, but in this configuration, it is a DC-DC converter that generates charging power for the lead-acid battery 213 located outside the battery case 33 in the electric vehicle 10. The transformer 95 is a heat source, but in this configuration, the connection part 97 with the connecting busbar 100 and the transformer 95 are arranged separately in the left-right direction on the circuit board 96, so that the heat sources are physically separated from each other and the thermal influence on each other can be suppressed.

[0058] Among the components mounted on the upper surface of the component mounting board 96, the transformer coil 95b and capacitor 95a of the transformer 95 are relatively large components. These large components are kept from coming into contact with the board support stay 61s. As shown in Figure 10, signal lines 2C1 and 2C2 extending from the component mounting board 96 are connected to the signal connector 1C located on the upper surface of the left side in the vehicle width direction of the battery case 33, and signal lines 2D1 and 2D2 extending from the component mounting board 96 are connected to the low-voltage power connector 1D adjacent to the signal connector 1C.

[0059] Figure 11 shows the substrate support stay 61s from below, along with its surrounding configuration. In Figure 11, the transformer coil 95b and capacitor 95a are shown by dashed lines. As shown in Figure 11, the substrate support stay 61s has openings 61s1 and 61s2 formed at positions corresponding to the transformer coil 95b and capacitor 95a of the transformer 95, respectively, to avoid these components. As a result, contact between the transformer coil 95b and capacitor 95a and the substrate support stay 61s is avoided, and the component mounting substrate 96 can be placed close to the substrate support stay 61s. This allows the component mounting substrate 96 to be placed close to the top plate portion 61d of the upper battery case 61, reducing the vertical space required for the placement of the component mounting substrate 96. In addition, the transformer coil 95b, which is a heat source, can be placed closer to the top plate portion 61d of the upper battery case 61.

[0060] In this configuration, as shown in Figure 10, the transformer coil 95b contacts the top plate portion 61d of the upper battery case 61 via the first heat transfer member 111. The first heat transfer member 111 can be made of a material with high thermal conductivity that can efficiently transfer the heat generated by the transformer coil 95b to the top plate portion 61d of the upper battery case 61. This allows the heat generated by the transformer coil 95b to be efficiently transferred to the upper battery case 61. As described above, the top plate portion 61d of the upper battery case 61 is provided with multiple ribs that improve the surface area of ​​the battery case 33 and enable efficient heat dissipation, so that the heat generated by the transformer coil 95b can be efficiently dissipated from the upper battery case 61.

[0061] [5.3 Battery Module 91 and Battery Module Substrate 94] Figure 12 is a perspective view of the battery module 91, and Figure 13 is a cross-sectional view showing the second heat transfer member 114 together with its surrounding configuration. The battery module 91 is formed in the shape of a roughly rectangular parallelepiped. A roughly rectangular parallelepiped is not limited to a rectangular parallelepiped, but includes shapes that are close to a rectangular parallelepiped. Each battery cell 92 of the battery module 91 is provided with a positive terminal T1 and a negative terminal T2 at its upper end, and a battery module substrate 94 is placed on the upper surface of each battery cell 92. The battery module substrate 94 is a substrate having busbars 94a that electrically connect the positive terminal T1 and negative terminal T2 of adjacent battery cells 92, and a wiring pattern for signal lines connected to each battery cell 92. The signal lines include wiring Lsa, Lsb (Figure 14) that conduct signals from a temperature sensor that acquires the temperature of each battery cell 92 and a voltage sensor that acquires the voltage of each battery cell 92. The battery modules 92 are connected in series by this battery module substrate 94.

[0062] The battery module substrate 94 has multiple holes 94b formed therein to expose the busbars 94a of each battery cell 92. These holes 94b expose the area around the busbars 94a, thereby also exposing parts of the positive terminal T1 and the negative terminal T2. The busbars 94a are plate-shaped conductive members that extend linearly along the upper surface of each battery cell 92, and are made of metal, for example. The busbars 94a connected to the highest potential and lowest potential battery cells 92 are indicated by reference numerals 94a1 and 94a2. These busbars 94a1 and 94a2 pass along the side of the battery module 91, extend downward, and are connected to the respective connecting busbars 100.

[0063] A battery control board 98 (Figures 7 and 11), which functions as a battery control unit, is connected to the battery module board 94. The battery control board 98 has a BMU (Battery Management Unit) that monitors and controls the state of the battery module 91, and detects the voltage, current, and temperature of each battery cell 92 via the battery module board 94, as well as recording the charging and discharging of the battery modules 91A and 91B. As shown in Figures 7 and 11, the battery control board 98 is positioned along the side of each battery module 91A and 91B and fits into the gap formed between each battery module 91A and 91B and the partition walls 61w1 and 61w2.

[0064] Furthermore, inside each hole 94b, the space surrounding the electrodes, consisting of the positive terminal T1 and the negative terminal T2, is filled by the substrate-side heat transfer member 112. When the battery modules 91A and 91B are fixed to the upper battery case 61, a sheet-shaped heat transfer member 113 is placed between the substrate-side heat transfer member 112 and the top plate portion 61d of the upper battery case 61. These substrate-side heat transfer member 112 and the sheet-shaped heat transfer member 113 constitute a second heat transfer member 114 provided between each battery module 91A and 91B and the upper battery case 61.

[0065] [5.4 Second Heat Transfer Member 114] As shown in Figure 13, of the second heat transfer members 114, the substrate-side heat transfer member 112 is in contact with the busbar 94a and the battery cell 92. In this configuration, the substrate-side heat transfer member 112 is made of a thermal interface material (TIM) such as a sheet or grease. In addition, the sheet-like heat transfer member 113 of the second heat transfer member 114 is provided so as to cover the surface of the substrate-side heat transfer member 112, and in this configuration, it is made of a thermally conductive insulating sheet.

[0066] Both the substrate-side heat transfer member 112 and the sheet-shaped heat transfer member 113 can be made of materials with high thermal conductivity capable of efficiently transferring heat from the busbars 94a and battery cells 92 to the upper battery case 61. This configuration allows for efficient transfer of heat generated by each battery cell 92 to the upper battery case 61. Furthermore, since the sheet-shaped heat transfer member 113 is insulating, it can also serve as an insulating member between the busbars 94a and the upper battery case 61. Also, since the substrate-side heat transfer member 112 is insulating, the busbars 94a are not electrically connected to the battery case 33. Note that the second heat transfer member 114 shown in Figure 13 is an example of a "heat transfer member" in this disclosure, and any material capable of transferring heat from battery modules 91A and 91B to the upper battery case 61 can be widely applied.

[0067] [6. Circuit Configuration] Figure 14 shows the circuit configuration of the saddle-type electric vehicle 10. As shown in Figure 14, the two battery modules 91A and 91B are connected in parallel to the component mounting board 96. Each battery module 91A and 91B is connected to the battery control board 98 via wiring L1a and L1b that conducts power to the battery modules 91A and 91B, and signal lines L1as and L1bs that conduct temperature and voltage signals to the battery modules 91A and 91B. The component mounting board 96 has a parallel connection section 201 to which each battery module 91A and 91B are connected in parallel, and includes a first branch circuit 202 connected from the parallel connection section 201 to the charge / discharge connectors 1A and 1B, and a second branch circuit 203 connected from the parallel connection section 201 to the low-voltage power connector 1D via a fuse 301 and a transformer 95.

[0068] The first branch circuit 202 includes a circuit connected to an inverter 211 that generates power to supply to the drive motor 13, and a circuit connected to a charger 212 that receives power from outside the electric vehicle 10. The circuit connected to the charger 212 is provided with disconnection circuits SW1 and SW2 that can disconnect the power supply path from the charger 212 to each battery module 91A and 91B. These disconnection circuits SW1 and SW2 switch between connected and disconnected states by signals from signal lines Lsw1 and Lsw2 connected to the signal connector 1C. A fuse 302 is provided between the disconnection circuit SW1 and the parallel connection section 201. The signal connector 1C receives a signal from the ECU 214, which controls the connected / disconnected state of the disconnection circuits SW1 and SW2.

[0069] In Figure 14, the parallel connection section 201 is branched to the inverter 211 and the charger 212 respectively, and connected to two sets of charge / discharge connectors 1A and 1B, but the configuration is not limited to this. Within the component mounting board 96, a circuit connecting the parallel connection section 201 and the inverter 211, and a circuit connecting the parallel connection section 201 and the charger 212 may be connected, and the circuits may be branched again in parallel on the inverter 211 or charger 212 side of the charge / discharge connectors 1A and 1B, and connected to the inverter 211 and the charger 212 respectively. In this case, the number of charge / discharge connectors 1A and 1B becomes one set, so the number of components in the charge / discharge connector can be reduced.

[0070] The second branch circuit 203 generates charging power for the lead-acid battery 213, which is used as an auxiliary battery, via the transformer 95, and functions as a circuit to charge the lead-acid battery 213. A circuit 204 is also formed that connects the wirings Lsa and Lsb, which are connected to each battery control board 98, to the ECU 214 via the signal connector 1C. The wirings Lsa and Lsb are used to communicate information between the battery control board 98 and the ECU 214, such as the temperature and voltage of each battery cell 92 obtained by the battery control board 98, and the current flowing through the battery modules 91A and 91B obtained by the ammeters 98a and 98b in the battery control board 98.

[0071] Furthermore, each battery control board 98 is equipped with pre-charge circuits 205a, 205b and fuses 303, 304 in the paths connected to the positive terminals of each battery module 91A, 91B. The pre-charge circuits 205a, 205b each include a first circuit 206 with a resistor R1 that conducts when the inverter 211 is pre-charged by opening and closing the disconnection circuit SW3, and a second circuit 207 that does not conduct during normal discharge and has no resistor. These circuits 206, 207 are connected in parallel. The circuit shown in Figure 14 is configured to enable proper operation of the saddle-type electric vehicle 10 even when either the battery module 91A or 91B is not connected.

[0072] [7. Effects] [7.1 Battery Structure for Attachment and Detachment] As described above, in this embodiment, the battery case 33 is fixed to the vehicle frame 11, and the battery modules 91A and 91B are supported in a structure that allows them to be attached to and detached from the battery case 33 from the underside of the electric vehicle 10. With this configuration, with the battery case 33 fixed to the vehicle frame 11, it becomes possible to easily attach, detach, and access the battery modules 91A and 91B by utilizing the space under the vehicle. This makes it possible to improve the workability related to the battery. By improving workability, the work time is reduced.

[0073] Furthermore, the battery case 33 contains a transformer 95, and a connecting bus bar 100 is positioned below the battery modules 91A and 91B, functioning as a connecting member that electrically connects the battery modules 91A and 91B to the transformer 95. This configuration makes it possible to easily attach, detach, and access the battery modules 91 and the connecting bus bar 100 by utilizing the space below the vehicle.

[0074] Furthermore, the battery case 33 is divisible into an upper battery case 61 and a lower battery case 62, with the upper battery case 61 having higher rigidity than the lower battery case 62. This configuration allows the battery modules 91A and 91B to be supported by the highly rigid upper battery case 61, thereby suppressing the effects of vibration and shock and stably supporting the battery modules 91A and 91B.

[0075] Furthermore, as shown in Figures 5 and 9, the height of the upper battery case 61 is greater than the height of the lower battery case 62 (Hb), and in a cross-sectional view along the vehicle width, the cross-sectional area of ​​the upper battery case 61 is greater than that of the lower battery case 62. This configuration makes it possible to make the rigidity of the upper battery case 61 higher than that of the lower battery case 62.

[0076] Furthermore, a rear suspension connecting portion 41 is provided on the outer surface of the upper battery case 61, to which one end 17a of the rear suspension 17 is connected. With this configuration, the rear suspension 17 is positioned almost horizontally, so the battery modules 91A, 91B and the rear wheel module 50 become flat, reducing the overall height and improving the freedom of placement of other functional components. In addition, since the battery modules 91A, 91B are detachably supported from below by the upper battery case 61, the rear suspension connecting portion 41 does not get in the way when attaching or detaching the battery modules 91A, 91B, etc., improving work efficiency. Moreover, the upper battery case 61 has sufficient rigidity to support the rear suspension 17, making it possible to stably support the battery module 91.

[0077] Furthermore, the outer surface of the upper battery case 61 is provided with rear frame connecting portion 43 and front frame connecting portion 44, to which the rear frame 34 and front frame 32 of the vehicle body frame 11 are connected. With this configuration, the battery modules 91A and 91B are detachably supported from below by the upper battery case 61, so that the frame connecting portions 43 and 44 do not get in the way when attaching or detaching the battery modules 91A and 91B, improving work efficiency. In addition, the upper battery case 61 has the rigidity to support the rear frame 34 and front frame 32, making it possible to stably support the battery modules 91A and 91B.

[0078] Furthermore, the battery modules 91A and 91B are detachably fixed to the upper battery case 61 by fastening members 102. The cell holder 93 of the battery modules 91A and 91B has a plurality of cell housing sections 93a for housing battery cells 92 and an insertion hole 93b through which the fastening member 102 is inserted. In an axial view of the insertion hole 93b, the insertion hole 93b is positioned between the cell housing sections 93a. With this configuration, the size of the battery modules 91A and 91B can be suppressed compared to the case where the insertion hole 93b is positioned on the periphery of the cell holder 93.

[0079] Furthermore, the cell holder 93 is provided with multiple cell housing sections 93a so as to arrange the battery cells 92 in a square orientation when viewed from above or below the electric vehicle 10. With this configuration, compared to, for example, a hexagonal close-packed arrangement, it becomes easier to place through holes 93b between the cell housing sections 93a, and the enlargement of the battery modules 91A and 91B can be effectively suppressed.

[0080] [7.2 Battery Structure for Heat Dissipation] In this embodiment, the battery case 33 has a transformer 95 that transforms the power of the battery modules 91A and 91B, and the battery modules 91A and 91B and the transformer 95 are fixed to either the upper battery case 61 or the lower battery case 62, and are in contact with the upper battery case 61 via the first heat transfer member 111 and the second heat transfer member 114. With this configuration, the heat from the battery modules 91A and 91B and the transformer 95 can be efficiently transferred to the upper battery case 61 via the respective heat transfer members 111 and 114. As a result, when the heat dissipation structure is concentrated in the upper battery case 61 and the other battery case, the lower battery case 62, is separated, it is possible to ensure heat dissipation performance while maintaining access to multiple internal components. Therefore, it becomes possible to improve work efficiency and manage the battery temperature appropriately.

[0081] The upper battery case 61 and the lower battery case 62 are examples of the "first battery case and second battery case" as disclosed herein. Alternatively, the battery modules 91A, 91B and the transformer 95 may be fixed to the lower battery case 62 and in contact with the lower battery case 62 via the first heat transfer member 111 and the second heat transfer member 114. Furthermore, the battery case 33 may be made separable in directions other than vertical, with the battery modules 91A, 91B and the transformer 95 fixed to one of the separable cases and in contact via the first heat transfer member 111 and the second heat transfer member 114.

[0082] Furthermore, the battery modules 91A and 91B have a plurality of battery cells 92 and a busbar 94a connecting the plurality of battery cells 92, with the busbar 94a positioned on the upper battery case 61 side of the battery modules 91A and 91B, and the busbar 94a in contact with the upper battery case 61 via the second heat transfer member 114. With this configuration, the heat from the heat-generating busbar 94a can be transferred to the upper battery case 61 side. As a result, it becomes unnecessary to position the heat dissipation structure of the heat-generating busbar 94a on the lower battery case 62 side, and when the lower battery case 62 is separated, it becomes possible to ensure heat dissipation performance while maintaining access to multiple internal components.

[0083] Furthermore, a battery module substrate 94 having signal lines is provided on the upper battery case 61 side of the battery modules 91A and 91B, and a hole 94b is provided in the battery module substrate 94 that exposes the bus bar 94a to the upper battery case 61 side. Inside the hole 94b, the bus bar 94a is connected to the upper battery case 61 via the first heat transfer member 111. With this configuration, the battery module substrate 94 is positioned between the battery modules 91A and 91B and the battery case 33, and even in situations where the heat transfer path from the battery modules 91A and 91B to the battery case 33 is easily restricted, heat can be efficiently transferred from the bus bar 94a to the upper battery case 61 via the hole 94b of the battery module substrate 94.

[0084] Furthermore, the positive terminal T1 and negative terminal T2 of the battery cell 92 are provided at one end of the battery cell 92, with one end positioned on the upper battery case 61 side and the other end connected to the first battery case (61) via the second heat transfer member 114. This configuration allows the heat dissipation structures of each terminal T1, T2 and the surrounding area, which generate a lot of heat, to be concentrated on the upper battery case 61 side. As a result, it becomes unnecessary to position each terminal T1, T2 and the surrounding heat dissipation structures on the lower battery case 62 side, making it possible to ensure heat dissipation performance while maintaining accessibility to multiple internal components when the lower battery case 62 is separated. Note that the upper battery case 61 is an example of "one battery case" in this disclosure, and the lower battery case 62 is an example of "the other battery case" in this disclosure.

[0085] Furthermore, the battery module substrate 94 is provided with holes 94b that expose the positive terminal T1 and the negative terminal T2 to the upper battery case 61, and the positive terminal T1 and the negative terminal T2 are connected to the upper battery case 61 via the second heat transfer member 114 inside the holes 94b. With this configuration, the battery module substrate 94 is positioned between the battery modules 91A and 91B and the battery case 33, and even in situations where the heat transfer path from the battery modules 91A and 91B to the battery case 33 is easily restricted, the heat from each terminal T1 and T2 and the surrounding area can be efficiently transferred to the upper battery case 61 via the holes 94b of the battery module substrate 94. In the case where the battery cell 92 has a positive terminal T1 at one end and a negative terminal T2 at the other end, the battery module substrate 94 is provided with a hole 94b that exposes one of the positive terminal T1 side and the negative terminal T2 side to the upper battery case 61 side, and one of the terminals is connected to the upper battery case 61 via the second heat transfer member 114 inside the hole 94b.

[0086] Furthermore, a connecting busbar 100 is positioned on the lower battery case 62 side of the battery modules 91A and 91B to electrically connect the battery module 91 and the transformer 95. This configuration prevents the connecting busbar 100 from obstructing the heat dissipation path from heat-generating components such as the battery modules 91A and 91B and the transformer 95 to the upper battery case 61.

[0087] Furthermore, the transformer 95 is positioned on a component mounting board 96 that extends in the short direction of the upper battery case 61, the battery modules 91A and 91B are positioned on one side in the longitudinal direction of the upper battery case 61, and the component mounting board 96 is positioned on the other side in the longitudinal direction. The connecting busbar 100 and the component mounting board 96 are connected on one side in the short direction of the battery case 33, and the transformer coil 95b of the transformer 95 is positioned on the other side in the short direction. With this configuration, the connection part 97 with the connecting busbar 100 and the transformer 95 are positioned separately on the board, thereby physically separating the heat sources and suppressing the thermal influence between them.

[0088] Furthermore, the upper battery case 61 has chambers C1 and C2 for housing battery modules 91A and 91B on one longitudinal side of the upper battery case 61, and a chamber C3 for housing a transformer 95 on the other longitudinal side of the upper battery case 33, and a partition wall 61w2 separates the chambers C1 and C2 housing the battery modules 91 from the chamber C3 housing the transformer 95. With this configuration, heat transfer between the battery modules 91A and 91B and the transformer 95 can be suppressed. Note that chambers C1 and C2 are examples of the "battery module housing area" in this disclosure, and chamber C3 is an example of the "transformer housing area" in this disclosure. The shape and number of the battery module housing area and the transformer housing area may be changed as appropriate.

[0089] Furthermore, the battery modules 91A and 91B each have a roughly rectangular cell holder 93 that houses a plurality of battery cells 92, and a battery module substrate 94 that functions as a battery control unit and is positioned on the cell holder 93. The upper battery case 61 is provided with a partition wall 61w1 that separates the plurality of battery modules 91A and 91B and functions as an inter-module partition wall facing the battery module substrate 94. This configuration suppresses the propagation of heat from the battery module substrate 94 to adjacent battery modules 91A and 91B.

[0090] [Other Embodiments] The above embodiments represent only one aspect of the present invention and can be modified and applied as needed without departing from the spirit of the present invention.

[0091] For example, in the above embodiment, the case in which the present invention is applied to the electric vehicle 10 shown in Figure 1 was described, but the present invention may be applied to a different electric vehicle. The electric vehicles to which the present invention can be applied are not limited to two-wheeled vehicles, but the present invention may also be applied to saddle-type electric three-wheeled vehicles and saddle-type electric four-wheeled vehicles classified as ATVs (All Terrain Vehicles), etc.

[0092] [Configurations supported by the above embodiment] The above embodiment supports the following configurations.

[0093] (Configuration 1) An electric vehicle comprising a battery in which a battery module including battery cells is housed in a battery case, and a vehicle frame, wherein the battery case is fixed to the vehicle frame, and the battery module is detachably supported from the underside of the vehicle relative to the battery case. With this configuration, while the battery case is fixed to the vehicle frame, it becomes possible to easily attach, detach, and access the battery module by utilizing the space below the vehicle, thereby improving battery-related workability.

[0094] (Configuration 2) An electric vehicle according to Configuration 1, wherein a transformer for changing the voltage of the battery module is located inside the battery case, and a connecting member for electrically connecting the battery module and the transformer is located below the battery module. With this configuration, the battery module and connecting busbar can be easily attached, detached, and accessed by utilizing the space below the vehicle.

[0095] (Configuration 3) The electric vehicle according to Configuration 1 or 2, wherein the battery case has an upper battery case and a lower battery case that can be divided vertically, and the rigidity of the upper battery case is higher than that of the lower battery case. With this configuration, by supporting the battery module in the upper battery case with higher rigidity, it becomes possible to suppress the effects of vibration and shock and to stably support the battery module.

[0096] (Configuration 4) The electric vehicle according to Configuration 3, wherein the thickness of the upper battery case in the height direction is greater than the thickness of the lower battery case in the height direction. With this configuration, it is possible to make the rigidity of the upper battery case higher than that of the lower battery case.

[0097] (Configuration 5) An electric vehicle according to Configuration 3 or 4, wherein, in a cross-sectional view along the vehicle width direction, the cross-sectional area of ​​the upper battery case is larger than the cross-sectional area of ​​the lower battery case. This configuration makes it possible to make the rigidity of the upper battery case higher than that of the lower battery case.

[0098] (Configuration 6) An electric vehicle according to any one of Configurations 1 to 5, having a rear suspension that suspends a swing arm that rotatably supports the rear wheel, and a rear suspension connecting portion is provided on the outer surface of the upper battery case that constitutes the upper part of the battery case, to which one end of the rear suspension is connected. With this configuration, since the rear suspension is arranged substantially horizontally, the battery module and rear wheel module become flat, reducing the overall height and improving the freedom of arrangement of other functional components. Furthermore, the rear suspension connecting portion does not get in the way when attaching or detaching the battery module, improving workability. In addition, the upper battery case has sufficient rigidity to support the rear suspension, making it possible to stably support the battery module.

[0099] (Configuration 7) An electric vehicle according to any one of Configurations 3 to 6, wherein a frame connecting portion is provided on the outer surface of the upper battery case that constitutes the upper part of the battery case, to which the vehicle body frame is connected. With this configuration, the frame connecting portion does not get in the way when attaching or detaching the battery module, etc., improving workability. In addition, the upper battery case has rigidity that can support the vehicle body frame, making it possible to stably support the battery module.

[0100] (Configuration 8) The electric vehicle according to any one of Configurations 1 to 7, wherein the battery module is detachably fixed to the upper battery case which constitutes the upper part of the battery case by fastening members, the battery module includes a cell holder which houses a plurality of battery cells, the cell holder which has a plurality of cell housing portions which house the battery cells and an insertion hole through which the fastening member is inserted, and the insertion hole is positioned between the cell housing portions in an axial view of the insertion hole. With this configuration, the size of the battery module can be suppressed compared to the case in which the insertion hole is positioned on the periphery of the cell holder.

[0101] (Configuration 9) The electric vehicle according to Configuration 8, wherein the cell holder is provided with a plurality of cell housings such that the battery cells are arranged in a square orientation when viewed from above or below the vehicle. With this configuration, it is easier to place through holes between the cell housings, and the size of the battery module can be effectively suppressed.

[0102] 10 Saddle-type electric vehicle 11 Body frame 12 Rear wheel 13 Drive motor 14 Front wheel 16 Swing arm 17 Rear suspension 33 Battery case 41 Rear suspension connection part 42 Swing arm connection part (frame connection part) 43 Rear frame connection part (frame connection part) 44 Front frame connection part 61 Case part (upper battery case, first battery case) 61w1 Partition wall (partition wall between modules) 61w2 Partition wall 62 Cover member (lower battery case, second battery case) 91, 91A, 91B Battery module 92 Battery cell 93 Cell holder 93a Cell housing part 93b Insertion hole 94 Battery module board 94a Bus bar 94b Hole 95 Transformer 95b Transformer coil 96 Component mounting board 98 Battery control board 100 Connecting busbar (connecting member) 101, 102 Fastening member 111 First heat transfer member 112 Substrate-side heat transfer member 113 Sheet-shaped heat transfer member 114 Second heat transfer member C1, C2 Chambers (battery module housing area) C3 Chamber (transformer housing area)

Claims

1. An electric vehicle comprising a battery in which battery modules (91A, 91B) including battery cells (92) are housed in a battery case (33), and a vehicle body frame (11), wherein the battery case (33) is fixed to the vehicle body frame (11), and the battery modules (91A, 91B) are detachably supported from the lower side of the vehicle relative to the battery case (33).

2. The electric vehicle according to claim 1, wherein a transformer (95) for transforming the voltage of the battery modules (91A, 91B) is located inside the battery case (33), and a connecting member (100) for electrically connecting the battery module (91) and the transformer (95) is located below the battery modules (91A, 91B).

3. The electric vehicle according to claim 1, wherein the battery case (33) has an upper battery case (61) and a lower battery case (62) that can be divided vertically, and the rigidity of the upper battery case (61) is higher than the rigidity of the lower battery case (62).

4. The electric vehicle according to claim 3, wherein the thickness of the upper battery case (61) in the height direction is greater than the thickness of the lower battery case (62) in the height direction.

5. The electric vehicle according to claim 3, wherein, in a cross-sectional view along the width direction of the vehicle, the cross-sectional area of ​​the upper battery case (61) is larger than the cross-sectional area of ​​the lower battery case (62).

6. The electric vehicle according to claim 1, having a rear suspension (17) that suspends a swing arm (16) that rotatably supports a rear wheel (12), wherein a rear suspension connecting portion (41) is provided on the outer surface of the upper battery case (61) that constitutes the upper part of the battery case (33), to which one end (17a) of the rear suspension (17) is connected.

7. The electric vehicle according to claim 3, wherein frame connecting portions (43, 44) to which the vehicle body frame (11) is connected are provided on the outer surface of the upper battery case (61) which constitutes the upper part of the battery case (33).

8. The electric vehicle according to claim 1, wherein the battery modules (91A, 91B) are detachably fixed to the upper battery case (61) which constitutes the upper part of the battery case (33) by fastening members (102), the battery modules (91A, 91B) include a cell holder (93) which houses a plurality of battery cells (92), the cell holder (93) has a plurality of cell housing portions (93a) which house the battery cells (92) and an insertion hole (93b) through which the fastening member (102) is inserted, and the insertion hole (93b) is positioned between the cell housing portions (93a) in an axial view of the insertion hole (93b).

9. The electric vehicle according to claim 8, wherein the cell holder (93) is provided with a plurality of cell housing portions (93a) such that the battery cells (92) are arranged in a square orientation when viewed from above or below the vehicle.

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