JP4325857B2 - Electric vehicle drive device - Google Patents

Description

  The present invention relates to a drive device for an electric vehicle, and more particularly to a drive device for an electric vehicle that constitutes a power unit in which a motor and a power transmission device that transmits power of the motor to wheels are integrated.

In recent years, electric vehicles driven by electric motors have been used. This electric vehicle drive device may be configured as a power unit in which a motor and a power transmission device that transmits the power of the motor to the vehicle are integrated. For example, Japanese Patent Laid-Open No. 5-42892 discloses an electric vehicle configured to transmit the power of a motor to a rear wheel using a V-belt type transmission, and includes a cooling fan and an exhaust port driven by the motor. And a motor housing having the following. In this electric vehicle, since the cooling fan rotates by the rotation of the motor and air flows in the motor housing, the cooling operation of the motor driving circuit (driver) including the motor and the semiconductor switching element can be obtained.
JP-A-5-42892

  In the electric vehicle, not only the motor but also the driver is cooled by the air blown by the cooling fan. However, since the drivers are arranged side by side in the axial direction of the motor, they protrude from the motor in the motor shaft extending direction. Therefore, the motor housing tends to be longer in the width direction of the vehicle body, and the entire power unit including the case of the power transmission device coupled to the motor housing tends to be longer in the width direction of the vehicle body. Therefore, it is desired to reduce the size of the power unit.

  Further, since the motor and the driver are generally connected by a high voltage line, it is also desired to reduce the wiring distance. Furthermore, a structure that can more efficiently dissipate the heat generated from the driver is desired.

  The objective of this invention is providing the drive device of the electric vehicle which can achieve size reduction, maintaining the cooling effect | action of a driver.

  In order to achieve the above object, the present invention provides a drive device for an electric vehicle comprising a motor and a power transmission device that transmits the power of the motor to the wheels of the vehicle, and the driver for driving the motor and the motor. There is a first feature in that a motor part case is provided, and the driver is disposed on an inner wall surface of the motor part case so as to substantially overlap the motor in a plan view.

  Further, the present invention has a second feature in that the driver is installed below the motor, and a third feature in that the driver is installed on the bottom inner wall surface of the motor case. There are features.

  Furthermore, the present invention has a fourth feature in that a heat sink is provided between the driver and the motor unit case, and the motor and the driver are disposed in front of the vehicle body in the motor unit case. The point has the fifth feature.

  According to the first to fifth features, the motor driver is arranged at a position overlapping with the motor, and the portion protruding from the motor in the axial direction can be eliminated or reduced. It does not increase in the width direction of the car body. In particular, when the driver is arranged below the motor as in the second feature, it is difficult to be affected by the heat generated from the motor.

  According to the third and fourth features, the heat generated by the driver is dissipated through the bottom wall surface of the motor case. In particular, according to the fourth feature, heat absorbed by the heat sink from the driver is released to the outside through the wall surface of the motor unit case.

  Further, according to the fifth feature, since the motor unit case is arranged in front of the vehicle body, it is easy to receive traveling wind and the cooling effect of the motor and the driver is high.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view of an electric motorcycle including a drive device according to an embodiment of the present invention, and FIG. 2 is a plan view of a vehicle body frame. The motorcycle 1 includes a body frame 2 and a cowl 3 that is supported by the body frame 2 and covers the body frame 2. In FIG. 1, in order to facilitate understanding of the structure of the vehicle body frame 2 and the like, the cowl 3 shows only a perspective and a schematic outline. The vehicle body frame 2 includes a head pipe 21 that is disposed slightly rearwardly at the front of the vehicle, an upper frame 22 that is welded at the front end to the head pipe 21 and extends downward and rearward, and a head pipe 21 below the upper frame 22. The lower frame 23 is welded at the front end and extends rearward, and the front end is joined to the upper frame 22, and the rear frame 24 is joined to the middle portion at the rear end of the lower frame 23 and extends rearward. .

  The upper frame 22 and the rear frame 24 joined to each other have a V-shape in a side view, and the lower frame 23 has a U-shape in a side view including a rear-falling portion and a rear-raising portion. That is, the vehicle body frame as a whole has a shape (referred to as “substantially U-shaped”) in which both ends in the longitudinal direction of the vehicle body are in a high position and almost the center in the longitudinal direction of the vehicle body is in a low position.

  On the other hand, as can be understood from FIG. 2, the upper frame 22 and the lower frame 23 branch from the head pipe 21 in the left-right direction of the vehicle and extend rearward. That is, the left and right frames 22, 23, and 24 are provided with respect to the vehicle. Batteries 4A, 4B, 4C for supplying electric power to the drive unit and the control unit of the motorcycle 1 are accommodated in a space surrounded by the pair of left and right frames 22, 23, 24. The batteries 4 </ b> A to 4 </ b> C are arranged in the front-rear direction of the vehicle body and are arranged in a step shape when viewed from the side. The battery 4A is positioned at the frontmost part of the vehicle body, and the batteries 4B and 4C are arranged so as to increase in the order toward the rear part. That is, the batteries 4A, 4B, 4C are arranged along the rear portion (rear frame 24) of the vehicle body frame 2 formed in a substantially U shape. The width of the battery 4A is set narrower than the batteries 4B and 4C so that the battery 4A can be accommodated inside the vehicle body frame 2 in conformity with the shape of the vehicle body frame 2 that is narrow in the vicinity of the head pipe 21, that is, in the front of the vehicle body. The lower frame 23 and the rear frame 24 are provided with cross members or trays (not shown) for holding the batteries 4A and 4B and 4C, respectively, and the batteries 4A, 4B, 4C are placed on these cross members or trays. The

  An occupant seat 5 is provided above the rear frame 24 so as to cover the batteries 4B and 4C. The passenger seat 5 includes a driver's seat and a passenger seat that follows the driver's seat. The occupant seat 5 is pivotally supported on the vehicle body by a hinge structure at the front end so that the occupant seat 5 can be opened and closed in the direction of the arrow 6.

  A steering shaft 7 is inserted into the head pipe 21, and a handle 8 is coupled to the upper end of the steering shaft 7, and a front fork 9 is coupled to the lower end. The front fork 9 supports the front wheel FW.

A power unit 10 as a driving device of the motorcycle 1 is suspended by shafts 18 a and 18 b connected to the lower frame 23 and the rear frame 24. The power unit 10 includes an electric motor 11 at the front and a speed reducer 12 at the rear. An output shaft of the speed reducer 12 (not shown) is connected to the rear wheel RW. The shaft of the motor 11 and the input shaft of the speed reducer 12 are connected by a belt 13 so that power can be transmitted. A drive unit including a driver circuit 14 for driving the motor 11 and a capacitor 15 is accommodated in the front portion of the power unit 10 and below the motor 11. A rear suspension device 16 having a shock absorber is provided between the rear portion of the power unit 10 and the rear frame 24. A similar rear suspension device is also provided on the right side of the vehicle body.
In front of the power unit 10, between the pair of left and right lower frames 23, a controller (control unit) 17 for the drive unit that supplies power to the motor 11 is provided.

  In the above configuration, the motor 11 is driven by the electric power supplied from the batteries 4A to 4C, and the power by the motor 11 is decelerated by the speed reducer 12 and transmitted to the rear wheels RW.

  When removing the batteries 4A, 4B, 4C from the motorcycle 1 for charging or the like, the occupant seat 5 is opened to open the upper side of the batteries 4B, 4C, and the batteries 4A to 4C are taken out through the opening. First, one of the batteries 4B and 4C is first lifted and taken out. Next, the other of the batteries 4B and 4C is similarly taken out. Subsequently, since a space is created by taking out the batteries 4B and 4C, the battery 4A can be lifted up and taken out while pulling the battery 4A backward through this space. The battery 4 </ b> A arranged at the forefront may be removed through a door 19 that can be provided at the upper part of the cowl between the occupant seat 5 and the head pipe 21.

  FIG. 3 is a view showing the front portion of the power unit with the left cover removed, and FIG. 4 is a view showing the rear portion. 5 is a plan sectional view of the front portion of the power unit, and FIG. 6 is a plan sectional view of the rear portion. FIG. 7 is a cross-sectional view of the main part of the front portion of the power unit (viewed from the front of the vehicle body).

  A front portion of the power unit 10 will be described with reference to FIGS. 3, 5, and 7. In the front portion of the power unit 10, a motor drive unit 46 including the motor 11, the driver circuit 14, and the capacitor 15 is provided. A case (hereinafter referred to as “swing unit case”) 51 of a swing unit 50 is rotatably connected to a case (hereinafter referred to as “motor unit case”) 26 that accommodates the motor 11 and the drive unit 46. That is, in the power unit 10, the motor unit case 26 and the swing unit case 51 are connected to form a “case member”.

  The motor case 26 includes a case intermediate portion 27 and lids 28 and 29 provided on the left and right sides of the case intermediate portion, respectively. The lids 28 and 29 are coupled to the intermediate portion 27 with a plurality of bolts 30. Upper portions of the lids 28 and 29 have bosses 31 and 32 formed with holes used for passing the shafts 18a and 18b when the motor unit case 6 is coupled to the vehicle body frame 2, respectively. Further, bolt holes 33 and 34 for receiving bolts for supporting a stand (not shown) used for allowing the motorcycle 1 to stand on its own are formed in the lower left and right.

  The motor unit case 26 has two upper and lower sections, and the motor 11 is accommodated in the upper section. The motor 11 includes a housing 35 and a stator 36, and a rotor 37 and a motor shaft 38 that are arranged coaxially with the stator 36. The housing 35 has long holes 40 in the front-rear direction of the vehicle, which are formed so that four stud bolts 39 that are planted and supported by the lid 28 can pass therethrough. The housing 35 is engaged with the lid 28 through 39. A nut 41 is screwed onto the stud bolt 39 protruding toward the housing 35 through the long hole 40 to fix the housing 35 to the lid 28. When the nut 41 is loosened, the implanted bolt is guided in the longitudinal direction of the long hole 40 in the long hole 40 by the long hole 40, and the housing 35 can be displaced in the longitudinal direction.

  As shown in FIG. 3, a belt tension adjusting bolt (hereinafter referred to as “tension bolt”) 42 is planted in the housing 35 of the motor 11 toward the front of the vehicle. The tension bolt 42 penetrates the front wall 43 of the motor case 26, that is, protrudes outward from the motor case 26, and a double nut 44 is screwed to the protruding portion. Among the four stud bolts 39, the tension bolt 42 is an intermediate portion between the upper one and the lower one, that is, almost the motor 11 so that the adjustment force due to the advancement and retraction of the tension bolt 42 can be applied to the motor 11 efficiently. The arrangement is set so as to be oriented toward the center.

  With the nut 41 fixing the housing 35 to the lid 28 of the motor part case 26 loosened, one side (end side) of the double nut 44 is loosened and the other side of the double nut 44 is rotated with respect to the tension bolt 42. When it is moved, the tension bolt 42 is screwed according to the rotation of the double nut 44. As a result, the housing 35 is displaced in the vehicle front-rear direction with respect to the motor unit case 26 in accordance with the rotation direction of the double nut 44. That is, the tension of the belt 13 can be adjusted by changing the distance between the motor shaft 38 and the input shaft (described later) of the speed reducer 12 by the rotation of the double nut 44. The movement limit of the housing 35 due to the action of the tension bolt 42 and the double nut 44 is indicated by two-dot chain lines 35a and 35b. The lid 29 is formed with an opening 29 a that is used to attach and detach the motor 11 to and from the motor unit case 26. Furthermore, a member 45 that covers the entire motor case 26 including the opening 29a from the right side of the vehicle body is provided.

  A drive unit 46 is provided in a section below the motor unit case 26. The drive unit 46 is disposed almost directly below the motor 11. Thereby, the width direction dimension of the motor part case 26 can be reduced so that the power unit 10 does not spread in the vehicle body width direction. In particular, the driver circuit 14 of the driving unit 46 is disposed on the bottom inner surface of the motor unit case 26. The driver circuit 14 includes a semiconductor element (switching element) 47 such as an FET, and controls the motor 11 by outputting a PWM signal in response to an instruction from the control unit 17. In order to increase the cooling effect of the semiconductor element 47, a heat sink 48 is provided. The motor unit case 26 is made of a material having good thermal conductivity such as aluminum alloy, and the driver circuit 14 is installed so that the heat sink 48 is in close contact with the inner surface of the bottom of the motor unit case 26 as shown in FIG. . As a result, the heat sink 48 can dissipate the heat conducted from the semiconductor element 47 and the like through the motor case 26 to the outside. The motor unit case 26 is provided at the front portion of the power unit 10. That is, in the traveling motorcycle 1, since the power unit 10 is in a position that is sufficiently susceptible to traveling wind, the heat radiation of the motor 11 and the drive unit 46 is further improved.

  The motor unit case 26 that houses the motor 11 and the drive unit 46 may be divided in the vertical direction. In other words, the compartment that houses the drive unit 46 can be a single independent block that can be attached to and detached from the upper compartment that houses the motor 11. For example, the lower part of the line indicated by the arrow AA in FIG. Thus, only the drive unit block can be removed from the motor unit case 26 to expose the drive unit 46 to the outside.

  Further, although the drive unit 46 is disposed below the motor 11, for example, the motor unit case 26 may be projected above the motor 11 and the drive unit 46 may be disposed at the projecting portion. If the motor 11 and the drive unit 46 are arranged so as to overlap in a plan view so that the drive unit 46 does not protrude from the motor 11 in the vehicle width direction, it is possible to avoid an increase in the width of the power unit 10. .

  As shown in FIG. 5, the swing unit case 51 is supported by the motor unit case 26 via bearings 52 and 53 provided coaxially with the motor shaft 38. The belt transmission device accommodated in the swing unit 51 includes a driving pulley 54, a driven pulley 73 (see FIGS. 4 and 6) described later, and a belt 13 as a “power transmission member” spanned between these pulleys. The drive pulley 54 is fixed to the motor shaft 38.

  The rear part of the power unit 10 will be described with reference to FIGS. 4 and 6. A main part of the speed reducer 12 provided at the rear part of the power unit 10 is a gear device incorporated in a space surrounded by a swing unit case 51 and a lid 55 of the swing unit case 51. An input shaft 56 of the speed reducer 12 is supported by bearings 57 and 58, and a gear 59 coupled to the input shaft 56 meshes with an intermediate large gear 61 coupled to an intermediate shaft 60. The small gear 62 coupled to the intermediate shaft 60 meshes with the gear 66 of the output shaft 65 supported by the swing unit case 51 and the lid 55 by bearings 63 and 64. Further, a hub 67 of the rear wheel RW is coupled to the output shaft 65.

  On the other hand, an outer member (clutch outer) 69 of the centrifugal clutch 68 is coupled to the portion 56a of the input shaft 56 protruding from the lid 55, and an inner member (clutch shoe 72a or spring 72b) via bearings 70 and 71. 72) and a driven pulley 73 are rotatably provided.

  The transmission device case 51 is covered with a left cover 74 and an outer cover 76 from above. Further, as shown in FIG. 4, a speed sensor 77 that detects the rotation of the gear 65 is provided facing the outer periphery of the gear 65 of the speed reducer 12. Further, a boss 78 for supporting the lower end of the rear suspension device 16 is formed at the rear end of the swing unit case 51.

  In the swing unit 50, when the driving pulley 54 is rotated by the motor 11, power is transmitted to the driven pulley 73 by the belt 13. When the rotational speed reaches the predetermined rotational speed, the clutch shoe 72 a overcomes the spring 72 b and expands, and is coupled to the clutch outer 68. When the clutch is thus engaged, the input shaft 56 rotates. The rotation of the input shaft 56 is decelerated by each gear of the speed reducer 12 and transmitted to the output shaft 64, and the rear wheel RW rotates.

  In the present embodiment, the motor 11 is displaceable with respect to the motor unit case 26 as a divided case member in which the swing unit case 51 is swingably connected to the motor unit case 26. The motor 11 may be displaceable with respect to the case member as an integral type instead of the divided type.

1 is a side view of an electric motorcycle including a drive device according to an embodiment of the present invention. FIG. 3 is a plan view of a body frame of the electric motorcycle. It is a figure which shows the front part of the power unit which removed the left side cover. It is a figure which shows the rear part of the power unit which removed the left side cover. It is a plane cross section of the front part of a power unit. It is a plane sectional view of the rear part of a power unit. It is sectional drawing (figure seen from the vehicle body front) of the motor part of a power unit.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 5 ... Passenger seat, 10 ... Power unit, 11 ... Motor, 12 ... Reduction gear, 13 ... Belt, 14 ... Driver circuit, 26 ... Motor part case, 35 ... Housing, 38 ... Motor Shaft, 39 ... Stud bolt, 43 ... Front wall of motor case, 44 ... Double nut, 50 ... Swing unit, 51 ... Swing unit case

Claims (8)

In a drive device for an electric vehicle comprising a motor and a power transmission device that transmits the power of the motor to the wheels of the vehicle,
A motor unit case that houses the motor and a driver for driving the motor and is coupled to the vehicle body frame ;
A swing unit case that is rotatably connected to the motor unit case and houses the power transmission device;
The drive device for an electric vehicle, wherein the driver is disposed on an inner wall surface of the motor portion case so as to substantially overlap the motor in a plan view.   The drive device for an electric vehicle according to claim 1, wherein the driver is installed below the motor.   The drive device for an electric vehicle according to claim 2, wherein the driver is installed on a bottom inner wall surface of the motor unit case. Drive apparatus for an electric vehicle according to any one of claims 1 to 3, characterized in that the heat sink is provided between the driver and the motor unit case. The motor and driver, driving apparatus for an electric vehicle according to any one of claims 1 to 4, characterized in that disposed in front of the vehicle body in the motor unit case. The driver driving apparatus for an electric vehicle according to any one of claims 1 to 5, characterized in that it consists of the driver circuit and a capacitor.   The drive device for an electric vehicle according to claim 6, wherein the capacitor is disposed in front of the vehicle with respect to the driver circuit. The swing unit case, the motor unit case, driving of the electric vehicle according to any one of claims 1 to 7, characterized in that it is swingably supported by the output shaft coaxial with said motor apparatus.

Images