JP2013126322A - Inverter unit and electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To commonize components of an inverter unit to be bilaterally symmetric.SOLUTION: The inverter unit 100 includes an inverter substrate on which an inverter circuit is mounted and an inverter cases (120, 130) that retains the inverter substrate, and converts input power from a battery into AC output power to supply the output power to a motor unit. Each of the inverter cases (120, 130) has a symmetric structure about a line in the vertical direction of an electric vehicle with respect to a symmetric axis in parallel to the cross direction of the electric vehicle.

Description

  The present invention relates to an inverter unit and an electric vehicle.

  Various electric vehicles have been proposed, and a three-wheel electric vehicle has been developed as one of them. For example, in a kind of three-wheeled electric vehicle, a motor unit is provided for each of two rear wheels as drive wheels, and an inverter unit that generates electric power for driving the motor unit is provided for each motor unit. At this time, an inverter unit designed for a two-wheeled electric vehicle may be applied to a three-wheeled electric vehicle as it is. However, since the structure required for the inverter unit, such as the shape of the inverter case that holds the inverter circuit, may differ between the left and right rear wheels, the case parts for the left rear wheel and the right rear wheel are designed separately. And need to be produced. Incidentally, in an electric vehicle having a rear arm incorporating a rear wheel drive motor, a structure in which the rear arm has a line-symmetric characteristic has been proposed (see Patent Document 1).

JP 2008-1000060 A

  Needless to say, if the case parts for the left rear wheel and the right rear wheel can be shared, it will contribute to the production cost reduction. In addition, the present invention is not limited to application to three-wheel electric vehicles, and if a structure that enables the commonality can be realized, for example, a two-wheel electric vehicle having an inverter unit arranged on the left side of the rear wheel and an inverter unit arranged on the right side of the rear wheel Common case parts and the like can be used for the two-wheeled electric vehicle, which is beneficial. Note that the structure disclosed in Patent Document 1 is not a structure related to the inverter unit.

  Therefore, an object of the present invention is to provide an inverter unit and an electric vehicle that contribute to the sharing of parts.

  An inverter unit according to the present invention includes an inverter case that holds a substrate on which an inverter circuit that converts input power from a power source into output power to a motor unit for driving a vehicle is mounted, With respect to a symmetry axis parallel to the longitudinal direction of the vehicle, the vehicle has a line-symmetric structure in the vertical direction of the vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the inverter unit and electric vehicle which contribute to sharing of components.

It is the external appearance top view of an electric vehicle which looked at the electric vehicle which concerns on embodiment of this invention from the side. It is the external appearance top view of an electric vehicle which looked at the electric vehicle which concerns on embodiment of this invention from diagonally backward left. The top view (a) of some components of the electric vehicle which concerns on embodiment of this invention, the functional block diagram (b) of the drive / braking function part 15 provided in the said electric vehicle, and the drive system of the said electric vehicle It is a functional block diagram (c). It is a schematic exploded perspective view of the main components of the inverter unit concerning the embodiment of the present invention. 1 is an external perspective view of an inverter unit according to an embodiment of the present invention. 1 is an external plan view of an inverter unit according to an embodiment of the present invention. It is a perspective view of an inverter unit in the state where a part of member was removed. It is a top view of an inverter unit in the state where a part of member was removed. It is a perspective view of the inverter board | substrate provided in the inverter unit. It is a top view of an inverter unit in the state where a part of member was removed.

  Hereinafter, an example of an embodiment of the present invention will be specifically described with reference to the drawings. In each of the drawings to be referred to, the same part is denoted by the same reference numeral, and redundant description regarding the same part is omitted in principle. In this specification, for simplification of description, a symbol or reference that refers to information, signal, physical quantity, state quantity, member, or the like is written to indicate information, signal, physical quantity, state quantity or Names of members and the like may be omitted or abbreviated.

  An electric vehicle according to an embodiment of the present invention will be described. The type of the electric vehicle is not limited as long as it is a vehicle that can travel using electric power. That is, for example, the electric vehicle may be a vehicle classified as a motorcycle, an automobile, a bicycle, or a senior car (registered trademark). The number of wheels provided in the electric vehicle is arbitrary, and the number may be 2 or 4, but here, a three-wheel electric vehicle having three wheels is taken as an example. The three-wheel electric vehicle may be a three-wheel electric vehicle having one front wheel and two rear wheels, or may be a three-wheel electric vehicle having two front wheels and one rear wheel. Take the three-wheeled motor vehicle as an example. FIG. 1 is an external plan view of an electric vehicle 1 as viewed from the side of the electric vehicle 1 according to the embodiment of the present invention. FIG. 2 is an external plan view of the electric vehicle 1 when the electric vehicle 1 is viewed obliquely from the left rear. The electric vehicle 1 shown in FIGS. 1 and 2 is a three-wheel electric vehicle including one front wheel 2 and two rear wheels 3. The electric vehicle 1 includes parts that are referred to by reference numerals 2 to 10 and 100. In the electric vehicle 1 shown in FIGS. 1 and 2, the rear wheel 3 is attached to the swing arm 5, but the rear wheel 3 may be directly attached to the main frame 4.

  Regarding the electric vehicle 1, the front direction corresponds to the direction in which the front wheel 2 exists when viewed from the rear wheel 3, and coincides with the moving direction of the electric vehicle 1 when the electric vehicle 1 goes straight. Regarding the electric vehicle 1, the downward direction corresponds to the direction in which gravity works, and the right direction corresponds to the right direction viewed from the driver of the electric vehicle 1 (the right direction when viewing the front from the back). Naturally, the reverse directions of the forward direction, the downward direction, and the right direction are the backward direction, the upward direction, and the left direction, respectively. The front-rear direction, the left-right direction, and the up-down direction may be considered as concepts having a certain width.

  The vehicle body, which is the main framework of the electric vehicle 1, is formed including the main frame 4 and the swing arm 5. The main frame 4 is formed of a resin material or a metal material having a substantially L-shaped cross section when a vertical plane is taken as a cross section. The vertical direction corresponds to the vertical direction. The front end of the main frame 4 is bent upward, and the front wheel 2 and the handle 6 are supported by the front end so that the driver can steer the front wheel 2 and the handle 6. A seat 7 on which the user sits down and a battery housing portion 8 are provided at the rear end side of the main frame 4 and at a substantially central portion in the front-rear direction of the electric vehicle 1. The battery accommodating portion 8 is provided below the seat 7 and can accommodate therein a battery BAT (see FIG. 3C) made of a secondary battery or the like. The seat 7 also serves as a lid for the battery housing portion 8 and is attached to the battery housing portion 8 so as to be openable and closable. A luggage platform 9 is provided behind the seat 7 and above the rear wheel 3.

  A swing arm 5 is connected to the main frame 4 at the rear of the main frame 4. The swing arm 5 is made of a resin material or a metal material which is the rear portion of the main frame 4 and extends rearward from the lower portion of the seat 7 and the battery housing portion 8. The rear wheel 3 is supported by the swing arm 5 at the rear end portion of the swing arm 5.

  Two driving / braking function units 15 (see FIG. 3A) provided in the electric vehicle 1 are attached to the swing arm 5, and the swing arm 5 is a driving wheel via the driving / braking function unit 15. The rear wheel 3 is supported. Further, an inverter unit 100 is attached to the swing arm 5. The inverter unit 100 may be attached to the main frame 4.

  FIG. 3A is a plan view of only the swing arm 5, the drive / braking function unit 15, the rear wheel 3, and the peripheral portion of the components of the electric vehicle 1 as viewed from above. When it is necessary to distinguish between the two rear wheels 3, the left rear wheel 3 and the right rear wheel 3 are also referred to as a left rear wheel 3 and a right rear wheel 3, respectively. The same applies to the swing arm 5, the driving / braking function unit 15, the motor unit 20, the brake unit 40, the inverter unit 100, and the like. As shown in FIG. 3A, the electric vehicle 1 can be provided with a left swing arm 5 that supports the left rear wheel 3 and a right swing arm 5 that supports the right rear wheel 3. Each swing arm 5 can be connected to the main frame 4 using a connector 16 so that each swing arm 5 can swing independently in the vertical direction using the suspension unit 10. The driving / braking function unit 15 includes a driving / braking function unit 15 for the left rear wheel 3 and a driving / braking function unit 15 for the right rear wheel 3. As shown in FIG. 3B, each driving / braking function unit 15 drives the rear wheel 3, that is, applies a driving force to the rear wheel 3, and brakes the rear wheel 3. That is, a brake unit 40 for applying a braking force to the rear wheel 3 is provided, and a driving force and a braking force are applied to the corresponding rear wheel 3.

  The motor unit 20 in each driving / braking function unit 15 generates the driving force using electric power output from the inverter unit 100 (hereinafter referred to as output electric power) as driving electric power. The electric vehicle 1 includes an inverter unit 100 (that is, the left inverter unit 100) that supplies output power to the motor unit 20 for the left rear wheel 3 (ie, the left motor unit 20), and a motor unit 20 ( That is, an inverter unit 100 (that is, the right inverter unit 100) that supplies output power to the right motor unit 20) is provided, and the left inverter unit 100 and the right inverter unit 100 are attached to the left swing arm 5 and the right swing arm 5, respectively. Can do. The battery BAT provided to the electric vehicle 1 is an example of an electric power source that accumulates and outputs electric power that is a source for generating the driving force. As shown in FIG. 3 (c), the battery BAT supplies each inverter unit 100 with DC power based on the stored charge of the secondary battery as input power, and each inverter unit 100 performs power conversion on the input power. By doing so, AC output power is generated. In the present embodiment, the output power is assumed to be three-phase AC power.

  Each inverter unit 100 may be disposed in each swing arm 5, or may be disposed between the left swing arm 5 and the right swing arm 5. Similarly, each driving / braking function unit 15 may be disposed in each swing arm 5, or may be disposed between the left swing arm 5 and the right swing arm 5. Further, the number of swing arms 5 provided in the electric vehicle 1 may be one. In this case, each rear wheel 3 is supported by one swing arm 5 connected to the main frame 4 via each drive / braking function unit 15.

  The inverter unit 100 for the left rear wheel 3 and the inverter unit 100 for the right rear wheel 3 have the same structure and function. Therefore, in the following description, the structure, function, and the like related to the inverter unit 100 for the left rear wheel 3 will be described unless it is particularly necessary to distinguish between left and right.

  FIG. 4 is an exploded perspective view of main components of the inverter unit 100. However, in FIG. 4, the shape of the components of the inverter unit 100 is simplified from the actual one. As shown in FIG. 4, the inverter unit 100 includes a first case member 101, a second case member 102, and an inverter board 103 on which an inverter circuit is mounted. The case members 101 and 102 form an inverter case 110 that holds the inverter board 103.

  The materials of the case members 101 and 102 are arbitrary. For example, the case members 101 and 102 can be formed of a metal such as an aluminum alloy, a resin, or a combination thereof. When the case members 101 and 102 are coupled with fastening parts such as screws, the case members 101 and 102 form a hollow, substantially rectangular parallelepiped member. The inverter unit 100 is formed by coupling the case members 101 and 102 to each other with the inverter substrate 103 sandwiched between the case members 101 and 102 (with the inverter substrate 103 fixed at a predetermined position in the case member 101). be able to.

  The case member 101 is provided with a battery side opening 104 and a motor side opening 105 which are holes. A power line (hereinafter referred to as a battery power line) for transmitting input power from the battery BAT to the inverter board 103 is disposed and inserted in the battery side opening 104, and the output power from the inverter board 103 is converted to the motor unit 20. A power line for power transmission (hereinafter referred to as a motor power line) is arranged and inserted in the motor side opening 105. That is, transmission of input power between the battery BAT and the inverter unit 100 is performed via the battery side opening 104, and transmission of output power between the inverter unit 100 and the motor unit 20 is performed via the motor side opening 105. . Various signal lines (including signal lines 203 and 204; see FIG. 5A), which will be described later, can also be arranged and inserted in the openings 104 or 105.

  The battery BAT is disposed at a position suitable for being connected to the inverter unit 100 at the front portion of the inverter unit 100. For example, the battery BAT can be disposed forward or above the inverter unit 100 and the inverter case 110. The motor unit 20 is disposed at a position suitable for being connected to the inverter unit 100 in the rear part of the inverter unit 100. For example, the motor unit 20 can be arranged behind or below the inverter unit 100 and the inverter case 110. In view of this, in the inverter unit 100 (that is, in the inverter case 110), the battery side opening 104 is preferably provided on the front side of the electric vehicle 1 and the motor side opening 105 is provided on the rear side of the electric vehicle 1 ( In other words, the battery-side opening 104 may be disposed in front of the motor-side opening 105). More specifically, for example, an opening 104 may be provided at the front end of the inverter case 110 (front end of the case member 101), and the battery power line may be drawn from the opening 104. 101 is provided at the rear end), and the battery power line is drawn from the opening 105. Thereby, it is not necessary to route the power line unnecessarily, and the power lines among the battery BAT, the inverter unit 100 and the motor unit 20 can be smoothly connected. As a result, the installation space of the power line can be reduced and the durability of the power line can be improved.

  Next, a detailed structural example of each component of the inverter unit 100 will be described with reference to FIGS. 5 (a), FIG. 5 (b), FIG. 6 (a), FIG. 6 (b), FIG. 7, FIG. 8, FIG. 9 (a), FIG. 9 (b) and FIG. , Each component of the inverter unit 100 for the left rear wheel 3 or each component connected to the inverter unit 100 for the left rear wheel 3, and each component shown in the drawings is provided in the electric vehicle 1. And can be included in the constituent elements of the inverter unit 100.

  The case member 120, the case member 130, and the inverter board 160 (see FIGS. 5A, 5B, and 8, etc.) are examples of the case member 101, the case member 102, and the inverter board 103 of FIG. 4, respectively. Yes, the matters described above for the case member 101, the case member 102, and the inverter board 103 also apply to the case member 120, the case member 130, and the inverter board 160. Therefore, the case composed of the case members 120 and 130 is also called the inverter case 110 (see FIG. 4).

  FIG. 5A is an external perspective view of the inverter unit 100 when the case member 130 is viewed from an oblique direction, and FIG. 5B is a view when viewed from the opposite side (radiation fin 125 side). 1 is an external perspective view of an inverter unit 100. FIG. 6A is a plan view of the inverter unit 100 when the left side is viewed from the right side of the electric vehicle 1, and FIG. 6B is a plan view of the inverter unit 100 when the right side is viewed from the left side of the electric vehicle 1. FIG. FIG. 7 is a perspective view of the inverter unit 100 with the case member 130 removed. FIG. 8 is a plan view of the inverter unit 100 when the left side is viewed from the right side of the electric vehicle 1 with the case member 130 removed. 9A is a perspective view of the inverter board 160 viewed from the solder surface side of the inverter board 160, and FIG. 9B is a perspective view of the inverter board 160 viewed from the component mounting surface side of the inverter board 160. It is a perspective view.

  As shown in FIG. 5A, FIG. 7, etc., the case member 120 protrudes toward the outside of the main casing with respect to the substantially box-shaped main casing that is hollow inside and whose one surface is open. This is a member to which the protruding pieces 121 to 124, 141 and 151 and the radiation fins 125 are added. In the case member 120, the protruding pieces 121 and 122 protrude from the main housing below the electric vehicle 1, the protruding pieces 123 and 124 protrude above the electric vehicle 1, and the protruding piece 141 protrudes from the front of the electric vehicle 1. A protruding piece 151 protrudes behind the electric vehicle 1. After fixing the inverter board 160 to a predetermined position in the case member 120 using screws or the like (see FIG. 7), the opened one surface of the main housing is closed with the plate-like case member 130, and a plurality of screws 171. (See FIG. 5A) and a plurality of holes provided in the case members 120 and 130 (including the screw holes 170 in FIG. 7), and the case members 120 and 130 are coupled and fixed to form an inverter unit. 100 is formed.

  The heat radiation fin 125 is involved in heat radiation of the electronic component on the inverter board 160 and has a function of promoting heat radiation of the electronic component. The fact that the heat dissipation fin 125 is involved in the heat dissipation of the electronic component means that the degree of heat dissipation of the electronic component (for example, the amount of heat dissipation per unit time) is greater when the heat dissipation fin 125 is present than when the heat dissipation fin 125 is not present. ) Will increase. The heat radiating fin 125 is composed of a plurality of metal pieces 126 protruding from the main housing to the left of the electric vehicle 1 (see FIG. 5B), and the metal pieces 126 extending in the front-rear direction of the electric vehicle 1 are in the air. The heat dissipation effect is enhanced by exposing to heat. The electronic components in which the radiating fins 125 are involved in heat dissipation include electronic components that form an inverter circuit 161 (see FIG. 9B) mounted on the inverter board 160. In particular, a plurality of switching elements in the inverter circuit 161 are included. 162 is included. Each switching element 162 is, for example, a semiconductor switching element such as a field effect transistor. In order to improve the heat dissipation effect of each electronic component including the switching element 162, an insulating heat dissipating sheet (not shown) is disposed in the space between the metal part forming the heat dissipating fin 125 and each electronic component. Anyway.

  In the inverter unit 100 shown in FIG. 5B and the like, the heat radiating fins 125 are formed integrally with the case member 120 (the same applies to the protruding pieces 121 to 124, 141, and 151). That is, the radiating fin 125 is formed on the case member 120 so that there is no seam with respect to the case member 120, and one object without a seam is formed by the radiating fin 125 and the case member 120 (projection pieces 121 to 124). , 141 and 151). Therefore, the material of the radiation fin 125 and the material of the case member 120 are the same. For example, the case member 100 and the heat radiating fins 125 can be formed of any metal material (such as an aluminum alloy). However, the case member 100 and the heat radiating fins 125 may be prepared as separate bodies and connected to each other using fastening parts (screws or the like).

  As shown in FIG. 5A and FIG. 6A, holes 121a to 124a penetrating along the left-right direction of the electric vehicle 1 are formed in the protruding pieces 121 to 124, respectively. On the other hand, four screw holes (not shown) in which female screws are formed are provided on the left side surface of the left swing arm 5, and four screws are passed through the holes 121a to 124a and the four screw holes. By performing the fastening operation, the inverter unit 100 as the left inverter unit 100 can be coupled and fixed to the left swing arm 5.

  In inverter case 110 formed by joining case members 120 and 130, an opening corresponding to battery side opening 104 (see FIG. 4) is present at the front end, and forward of electric vehicle 1 from the opening. A battery power line lead-out portion 140 having a cavity inside is formed toward the side. The battery power line lead-out portion 140 is formed by attaching a cover 142 made of a resin material or the like to the above-described protruding piece 141 from the right side of the electric vehicle 1 using screws or the like. It may be considered that the drawer 140 corresponds to the opening 104 in FIG. A pair of battery power lines 201 and 202 and signal lines 203 and 204 as the above-described battery power lines are disposed in the cavity in the drawer 140. In the drawer part 140, the lines 201 to 204 extend along the front-rear direction of the electric vehicle 1. One end of each of the battery power lines 201 and 202 is connected to the inverter board 160 using the round terminals 201a and 202a (see FIG. 7), and the other end of each of the battery power lines 201 and 202 is connected to the battery BAT. As a result, the input power due to the discharge of the battery BAT is supplied to the inverter board 160 via the battery power lines 201 and 202. Note that the drawer portion 140 may be considered as a component of the inverter case 110.

  A control circuit (not shown) provided on the inverter board 160 can communicate arbitrary information with a block (not shown) for controlling the battery BAT (charging / discharging control, etc.) via the signal line 203. Arbitrary information can be communicated with a host controller or the like through a CAN (Controller Area Network) in the electric vehicle 1 formed including the signal line 203. Further, the control circuit can receive an output signal or the like of a sensor that detects the state of the motor provided in the motor unit 20 (detection result signal of the magnetic pole position of the rotor, etc.) via the signal line 204. Inverter circuit 161 can be controlled based on the signal received via 204.

  The inverter circuit 161 (see FIG. 9B) uses a plurality of switching elements 162 to convert the input voltage from the battery BAT into output power to the motor unit 20 for driving the electric vehicle 1, that is, three-phase AC power. Then, a three-phase AC voltage corresponding to the three-phase AC power is output. So-called bus bars 211 to 213 made of metal plates are connected to the inverter board 160 (see FIGS. 7 and 8), and the three-phase AC voltage is applied to the bus bars 211 to 213.

  In the inverter case 110 formed by connecting the case members 120 and 130, an opening corresponding to the motor side opening 105 (see FIG. 4) exists at the rear end, and the opening of the electric vehicle 1 is provided from the opening. A motor power line coupling portion 150 having a cavity inside is formed toward the rear side. The motor power line coupling portion 150 is formed by attaching a molded product 152 and a cover 153 made of a resin material or the like to the above-described protruding piece 151 from the right side of the electric vehicle 1 using screws or the like. A hole 154 is formed in the rear end portion of the coupling portion 150 (see FIGS. 5A and 5B). The motor power line coupling portion 150 may be considered to include the opening 105 in FIG. 4, or the hole 154 may be considered to correspond to the opening 105 in FIG. 4. The coupling unit 150 may be considered as a component of the inverter case 110.

  FIG. 10 is a plan view of the inverter unit 100 when the left side is viewed from the right side of the electric vehicle 1 with the case member 130 and the cover 153 removed. In FIG. 10, the bus bars 211 to 213 are represented by dot areas, and the second bus bars 221 to 223 are represented by hatched areas. A terminal block 155 is provided in the coupling portion 150. The bus bars 211 to 213 pulled out from the rear end portion of the inverter case 110 are guided to the terminal block 155, and the bus bars 211 to 213 are connected to the bus bars 221 to 223 made of metal plates using screws or the like in the terminal block 155, respectively. Is done. The bus bars 221 to 223 are connected to the motor unit 20 through the holes 154. As a result, the three-phase AC power is transmitted to the motor unit 20 via the bus bars 211 to 213 and 221 to 223, and the driving force is generated. In this manner, the bus bars 211 to 213 and 221 to 223 that form the motor power lines described above are arranged and connected in the coupling portion 150. In coupling portion 150, the motor power line extends along the front-rear direction of electric vehicle 1. The motor power line may be formed using a flexible cable (harness) instead of a metal plate bus bar. Similarly, the battery power lines 201 and 202 may be formed of a flexible cable (harness) or a metal plate bus bar.

  By the way, the inverter unit 100 configured as described above can be provided with symmetry with the one-dot chain line AS (see FIG. 6A, etc.) as the axis of symmetry. Therefore, hereinafter, the one-dot chain line AS is referred to as an axis of symmetry. The symmetry axis AS is an axis parallel to the front-rear direction of the electric vehicle 1 and is an axis that divides the inverter case 110 (each of the case members 120 and 130) and the inverter board 160 into two equal parts in the vertical direction of the electric vehicle 1. Also good.

  For example, the inverter case 110 may have a line-symmetric structure in the vertical direction of the electric vehicle 1 with respect to the symmetry axis AS (in other words, it may be line-symmetric). Further, the inverter case 110 preferably has a plane-symmetric structure with respect to a plane of symmetry that includes the axis of symmetry AS and is parallel to the left-right direction of the electric vehicle 1 (in other words, plane-symmetric). The line symmetry is one side of the plane symmetry.

  By providing the inverter case 110 with such symmetry, the common inverter case 110 and the inverter unit 100 can be commonly used as the inverter case and the inverter unit for the left and right rear wheels 3. This is because the left inverter case 110 can function as the right inverter case 110 as it is if the left inverter case 110 is rotated 180 degrees around the vehicle body center line. The vehicle body center line here is a line parallel to the front-rear direction of the electric vehicle 1, passes through the center between the left and right rear wheels 3, and the position in the vertical direction of the electric vehicle 1 is the same as the symmetry axis AS. Point to a line. Due to the symmetry, a common inverter case 110 can be attached to each swing arm 5 under common conditions. Needless to say, the sharing of parts contributes to the reduction of production costs of the inverter case, the inverter unit including the inverter case, and the electric vehicle.

  The symmetry in the inverter case 110 preferably includes the symmetry of a plurality of attachment portions in the inverter case 110. The attachment part here refers to a part for attaching the inverter case 110 and the inverter unit 100 to the vehicle body of the electric vehicle 1 (in this embodiment, the swing arm 5). In this embodiment, the protruding piece 121 and the hole 121a, the protruding piece 122 and the hole 122a, the protruding piece 123 and the hole 123a, and the protruding piece 124 and the hole 124a are the first, second, third, and fourth attachment portions, respectively. It corresponds to. The first, second, third, and fourth attachment portions have the same structure and shape as each other, but are disposed at different positions from each other, but the first, second, third, and fourth attachment portions. Is preferably arranged at a symmetrical position in the vertical direction of the electric vehicle 1 with respect to the symmetry axis AS. That is, when the position of the mounting portion (corresponding to the protruding pieces 123 and 124 and the holes 123a and 124a in FIG. 6B) placed above the symmetry axis AS is folded downward with respect to the symmetry axis AS, the folding portion is folded. The position of the mounted portion is preferably coincident with the position of the mounting portion (corresponding to the protruding pieces 121 and 122 and the holes 121a and 122a in FIG. 6B) disposed below the symmetry axis AS.

  When the inverter unit 100 is attached to the right swing arm 5, it is only necessary to perform a fastening operation by passing four screws through the four screw fixing holes and holes 121a to 124a provided on the right side surface of the right swing arm (left In the swing arm 5, the holes 123a and 124a are located above the symmetry axis AS, whereas in the right swing arm 5, the holes 121a and 122a are located above the symmetry axis AS. If the mounting portion is symmetrical as described above, the common inverter unit 100 can be connected to each swing arm 5 only by providing mounting holes (screw holes) for the inverter unit 100 at fixed positions on the left and right swing arms 5. It becomes possible to attach to.

  Further, the symmetry in the inverter case 110 preferably includes the symmetry of the heat dissipating fins 125. That is, it is preferable that the radiation fins 125 have a line-symmetric structure with respect to the axis of symmetry AS in the vertical direction of the electric vehicle 1 (in other words, line-symmetric). It is preferable that the radiating fin 125 further has a plane-symmetric structure with respect to a plane of symmetry that includes the axis of symmetry AS and is parallel to the left-right direction of the electric vehicle 1 (in other words, plane-symmetric). The line symmetry is one side of the plane symmetry. In the example shown in FIG. 5B and FIG. 6B and the like, the positional relationship between the plurality of metal pieces 126 positioned above the symmetry axis AS and the symmetry axis AS and the plurality of positions positioned below the symmetry axis AS. The positional relationship between the metal piece 126 and the symmetry axis AS coincides with each other.

  When the common inverter unit 100 including the heat radiation fins 125 is used for the left and right motor units 20, the heat radiation conditions are the same between the left and right inverter units 100 by providing the heat radiation fins 125 with the above symmetry. This leads to the common use of electronic components and inverter case structure (common use between left and right), and simplifies the work of heat radiation design compared to the case where heat radiation conditions differ between left and right (simply halved). The benefits are high.

  Similarly to the inverter case 110, the inverter board 160 may have a line-symmetric structure in the vertical direction of the electric vehicle 1 with respect to the symmetry axis AS (in other words, line symmetry). The symmetry in the inverter board 160 may include the symmetry of the plurality of switching elements 162. When the plurality of switching elements 162 are arranged at symmetrical positions in the vertical direction of the electric vehicle 1 with respect to the symmetry axis AS. Good (see FIG. 9B).

  More specifically, for example, the plurality of switching elements 162 forming the inverter circuit 161 are divided into a first switching element group including two or more switching elements 162 and a second switching element group including two or more switching elements 162. The switching elements 162 of the first switching element group are arranged along the front-rear direction of the electric vehicle 1 while being positioned above the symmetry axis AS. Each switching element 162 of the second switching element group is arranged along the front-rear direction of the electric vehicle 1 while being positioned below the symmetry axis AS. And it is good to arrange | position the switching element 162 of a 1st switching element group, and the switching element 162 of a 2nd switching element group in the symmetrical position in the up-down direction of the electric vehicle 1 regarding symmetry axis AS. As shown in FIG. 9B, when each of the first and second switching element groups includes the first to sixth switching elements 162, the first to sixth switching elements 162 in the first switching element group. And the first to sixth switching elements 162 in the second switching element group are preferably arranged at symmetrical positions in the vertical direction of the electric vehicle 1 with respect to the symmetry axis AS.

  By giving such a symmetry to the plurality of switching elements 162, the heat radiation condition of the inverter circuit 161 can be made equal even when the inverter unit 100 is attached to either the left or right swing arm 5. This leads to common use of electronic components (common use between left and right), and simplifies (simply halved) the work of heat radiation design compared to the case where heat radiation conditions differ between right and left. The benefits are high.

  Further, in order to increase the symmetry of the inverter unit 100, components other than the plurality of mounting portions, the heat radiation fins 125, and the plurality of switching elements 162 (for example, the openings 104 and 105 in FIG. The drawer part 140 and the coupling part 150) in FIG. 5A and the like may also have a line-symmetric structure in the vertical direction of the electric vehicle 1 with respect to the symmetry axis AS. In the inverter case 110, the distance between the power line 201 and the symmetry axis AS and the distance between the power line 202 and the symmetry axis AS may be the same. Of the bus bars 211 and 213, the distance between the bus bar 211 and the symmetry axis AS and the distance between the bus bar 213 and the symmetry axis AS may be the same in the metal portion extending in the front-rear direction of the electric vehicle 1. And 213 may be provided on the axis of symmetry AS.

  Needless to say, the left rear wheel 3 and the right rear wheel 3 are drive wheels disposed on the left side and the right side with respect to the central axis of the vehicle body along the longitudinal direction of the electric vehicle 1. The motor unit and the brake unit provided in the electric vehicle 1 include a left motor unit 20 and a left brake unit 40 for applying a driving force and a braking force to the left rear wheel 3 and are driven with respect to the right rear wheel 3. The inverter unit provided in the electric vehicle 1 includes a right motor unit 20 and a right brake unit 40 for applying force and braking force. The inverter unit provided for the left motor unit 20 generates output power for the left motor unit 20 and the right motor unit 20. A right inverter unit 100 that generates output power is included. As a matter of course derived from the above-described symmetry, the symmetrical structural component of the left inverter unit 100 and the symmetrical structural component of the right inverter unit 100 have a plane-symmetric structure with respect to a symmetry plane orthogonal to the left-right direction of the electric vehicle 1. This is good (in other words, it should be plane-symmetric with respect to the symmetry plane), whereby the commonality between the left and right of the inverter unit 100 can be promoted. The symmetrical structural parts of the inverter unit 100 include the inverter case 110 and the inverter board 160, and particularly preferably include, for example, the plurality of mounting portions, the heat radiation fins 125, and the plurality of switching elements 162 described above.

  Although the example of the embodiment when the present invention is applied to a three-wheel electric vehicle has been described above, the present invention can also be applied to an electric vehicle other than the three-wheel electric vehicle. For example, the present invention can be applied to a four-wheel electric vehicle in which the front wheel 2 includes a left front wheel and a right front wheel, and the present invention is applied to a two-wheel electric vehicle in which only one rear wheel 3 is provided. Is also possible. In this type of two-wheeled electric vehicle, only one set of the motor unit 20, the brake unit 40 and the inverter unit 100 is provided, and the motor unit 20, the brake unit 40 and the inverter unit 100 are either on the left side or the right side of the rear wheel 3. Arranged on one side. When the symmetry as described above is not provided with respect to the structure of the inverter unit, it is necessary to change the components of the inverter unit between when it is provided on the left side of the rear wheel 3 and when it is provided on the right side ( It may be necessary to design and produce the left part and the right part separately), or the heat radiation conditions may be different. If the inverter unit has the symmetry according to the present invention, such necessity and the like are avoided, and as a result of the common use of parts, a production cost reduction effect and the like are expected.

<< Deformation, etc. >>
The embodiment of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims. The above embodiment is merely an example of the embodiment of the present invention, and the meaning of the term of the present invention or each constituent element is not limited to that described in the above embodiment. The specific numerical values shown in the above description are merely examples, and as a matter of course, they can be changed to various numerical values. As annotations applicable to the above-described embodiment, annotation 1 and annotation 2 are described below. The contents described in each comment can be arbitrarily combined as long as there is no contradiction.

[Note 1]
In the above-described example, the number of attachment portions provided in the inverter unit 100 is four. However, the number may be any number as long as the number is two or more.

[Note 2]
Although different from the above-described embodiment, in an electric vehicle, wheels driven by the motor unit 20 (that is, driving wheels) are provided in front of the inverter unit 100. As a result, the motor unit 20 is in front of the inverter unit 100. There may be a case where a power source (for example, battery BAT) for the motor unit 20 is provided at the rear of the inverter unit 100 (such as when two front wheels are included in the drive wheels in a four-wheel electric vehicle). In such a case, in the inverter unit 100 (that is, in the inverter case 110), the battery side opening 104 is provided on the rear side of the electric vehicle 1 and the motor side opening 105 is provided on the front side of the electric vehicle 1. (I.e., the battery side opening 104 may be disposed behind the motor side opening 105).

DESCRIPTION OF SYMBOLS 1 Electric vehicle 3 Rear wheel 5 Swing arm 15 Drive / braking function part 20 Motor unit 40 Brake unit 100 Inverter unit 101,102,120,130 Case member 103,160 Inverter board | substrate 104 Battery side opening part 105 Motor side opening part 110 Inverter Case 125 Radiation fin 140 Battery power line lead-out part 150 Motor power line coupling part 161 Inverter circuit 162 Switching element 201, 202 Battery power line 203, 204 Signal line 211-213, 221-223 Bus bar (motor power line)
AS symmetry axis

Claims (7)

An inverter case that holds a substrate on which an inverter circuit that converts input power from a power source into output power to a motor unit for driving a vehicle is mounted;
The inverter unit has an axisymmetric structure in a vertical direction of the vehicle with respect to an axis of symmetry parallel to a longitudinal direction of the vehicle. The inverter case includes a plurality of attachment portions for attaching the inverter unit to the vehicle body of the vehicle,
2. The inverter unit according to claim 1, wherein the plurality of attachment portions are arranged at symmetrical positions in the vertical direction of the vehicle with respect to the symmetry axis. The inverter case includes heat dissipation fins that are involved in heat dissipation of the electronic components on the substrate
The inverter unit according to claim 1, wherein the radiating fin has a line-symmetric structure with respect to the axis of symmetry in a vertical direction of the vehicle. The inverter circuit includes a plurality of switching elements for converting the input power into the output power,
The inverter unit according to any one of claims 1 to 3, wherein the plurality of switching elements are arranged at symmetrical positions in the vertical direction of the vehicle with respect to the symmetry axis. The inverter case includes a first opening in which a first power line for transmitting the input power is disposed, and a second opening in which a second power line for transmitting the output power is disposed.
In the inverter case, one of the first opening and the second opening is disposed on the front side of the vehicle, and the other is disposed on the rear side of the vehicle. Item 5. The inverter unit according to any one of Items 4. With the inverter unit as a reference, the power source is disposed on the front side of the vehicle and the motor unit is disposed on the rear side of the vehicle.
6. The inverter unit according to claim 5, wherein, in the inverter case, the first opening is disposed on the front side of the vehicle and the second opening is disposed on the rear side of the vehicle. A motor unit for applying driving force to the driving wheels of the vehicle;
A power source that outputs input power for generating the driving force;
An inverter circuit having an inverter case that holds the substrate on which the inverter circuit is mounted and an inverter circuit that converts the input power into output power for generating the driving force in the motor unit; and
A vehicle body to which the motor unit and the inverter unit are attached;
The drive wheel,
An electric vehicle as the vehicle, wherein the inverter unit according to any one of claims 1 to 6 is used as the inverter unit.

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