JP5692003B2 - Electrical connection structure between inverter and drivetrain with built-in motor - Google Patents

Description

  The present invention relates to an electrical connection structure between the two housings for securing a power supply path from the inverter to the motor between the housing of the inverter and the housing of the drive train with a built-in motor.

  An electric vehicle having a wheel driving motor includes an inverter that converts direct current of a battery into alternating current power suitable for driving the motor. Since the motor for driving the vehicle has a large output torque, an inverter having a large capacity is also provided. The power supply line from the battery to the motor through the inverter is also a large-capacity thick cable or an elongated metal plate. An elongated metal plate as a high-power transmission medium is called a bus bar (bus). In addition, the “electric vehicle” in this specification includes a hybrid vehicle including both a wheel driving motor and an engine.

  A thick wire cable is difficult to bend, and if a thick wire cable is used as a power transmission medium between the battery and the inverter or between the inverter and the battery, it is difficult to route the wire cable. Therefore, it has been proposed that the inverter and the motor are arranged close to each other and connected by a bus bar (for example, Patent Document 1). Note that the housing that houses the motor also incorporates a gear set and the like, and the motor and the gear set may be collectively referred to as a drive train (or power train). In this specification, both the drive system unit including only the motor and the drive system unit including the motor and the gear set are collectively referred to as “drive train”.

JP 2009-142038 A

  When a bus bar is used, the wiring path from the connector provided on the inverter housing to the connector provided on the drive train housing is determined by the shape of the bus bar, so wiring is easy (the bus bar made of elongated metal plate is easy) The initial shape becomes the wiring path itself). On the other hand, if one end of the bus bar is fixed, the position of the other end is determined. Therefore, it is difficult to provide a connector at each end of the bus bar and attach each connector independently on both the inverter side and the drive train side. Here, the “connector” refers to a cover that shields the connection portion between the inverter side terminal (or drive train side terminal) and the bus bar from the outside. If it is possible to cover the entire bus bar with a housing (bus bar housing) corresponding to the connector and fix both ends of the bus bar housing to the inverter housing and the drive train housing, respectively, using the fact that the bus bar is difficult to deform, The effect of improving the workability of “connector connection” and reducing the number of parts can be expected.

  However, when a bus bar housing that covers the entire bus bar is adopted, there arises a problem that the alignment between one end of the bus bar housing and the inverter housing and the alignment between the other end of the bus bar housing and the drive train housing are caused simultaneously. . Increasing the clearance (positioning tolerance) is not preferable from the viewpoint of dust removal or insulation. In particular, a seal material is attached to the connector joint for dust removal, insulation, and waterproofing. However, if the positioning of both members with the seal material between them is not accurate, there will be a gap on the side of the seal material. As a result, the sealing effect is reduced. This specification was created in view of the above problems. This specification describes the workability of assembling the busbar housing that covers the busbar to the busbar that electrically connects the inverter and the drivetrain. Provide technology to improve

  In the technology disclosed in this specification, the openings at both ends of the bus bar housing are oriented in the same direction, the joint between one opening (first opening) and the inverter housing, and the other opening (first 2 openings) and the drive train housing, either one of the joining portions is joined between the end faces, and the other is joined between the peripheral surfaces of the cylinders. For the sake of explanation, the direction in which the opening is facing is defined as the X axis, and the Y axis and the Z axis are set in a direction perpendicular to the X axis. The first opening is joined to the end face and a plane around the inverter terminal group (terminal group for connection to the bus bar), and the second opening is formed in a cylindrical shape extending in the X-axis direction. It joins with the cylindrical surrounding part provided around the group. Since the second opening and the surrounding portion are joined to each other, the YZ direction is constrained, but there is room for movement in the X direction while maintaining contact between the two. On the other hand, since the first opening is joined at the end face, the movement in the X direction is restricted, but there is room for movement in the YZ direction while maintaining the contact between the two. If the cylindrical second opening is inserted into the surrounding part and the bus bar housing is pushed in until the end face of the first opening comes into contact with the plane of the inverter housing, the cylindrical surface of the second opening and the surrounding part are in close contact with each other. The first opening and the side surface of the inverter housing can be easily brought into close contact with each other. One of the bus bar housing opening portions facing in the same direction is joined at the end face, and the other is joined at the peripheral surface of the cylinder, so that the inverter housing and the opening, and the drive train housing and the opening Can be joined without gaps. The opening of the bus bar housing and the drive train housing may be joined at the end surface, and the joining of the bus bar housing and the inverter housing may be joined at the peripheral surface of the cylinder.

  A specific embodiment disclosed in this specification is as follows. This technology relates to an electrical connection structure for securing a power supply path between an inverter that supplies electric power to a wheel driving motor and a motor built-in drive train that is arranged adjacent to the inverter. The inverter and the drive train are electrically connected by a bus bar (elongated metal plate). Of the terminal group connected to the bus bar, the terminal group provided on one of the drive train casing and the inverter casing is referred to as a first terminal group, and the terminal group provided on the other casing is the second terminal. It is called a group. Strictly speaking, the “terminal group provided in the housing” means “a terminal group provided so as to be exposed from the housing”.

The first terminal group and the second terminal group are provided to face the same direction. In other words, the second terminal group is provided on the side surface of the other housing facing the same direction as the side surface of the one housing on which the first terminal group is provided. From the connection portion between the first terminal group and the bus bar to the connection portion between the second terminal group and the bus bar, the entire bus bar is covered with the bus bar housing and the housing cover . The bus bar housing has a first opening and a second opening that open in the same direction. The first opening is attached to one casing with a planar sealing material sandwiched between the end face and the plane of one casing side surface surrounding the first terminal group . The second opening is cylindrical. The second opening has a cylindrical sealing material sandwiched between the cylindrical peripheral surface and the peripheral surface of the surrounding portion provided in the other casing so as to surround the second terminal group. Attached to.

  The above-described electrical connection structure can achieve a good seal between the inverter housing and the bus bar housing and a good seal between the drive train housing and the bus bar housing in connection with the bus bar. .

  The first opening may be joined to the inverter housing, and the second opening may be joined to the inverter housing. The inverter is located adjacent to the drive train, but typically the inverter is fixed to the top of the drive train. In this case, the first opening is attached to the inverter casing with the planar seal interposed therebetween, and the second opening is attached to the drive train casing with the cylindrical sealing material sandwiched below the first opening. It is good to have a structure. This is because workability is better when the fitting portion by the cylinder is on the lower side. In that case, at least one of the first terminal group or the second terminal group may have a bolt fastening surface for fastening the bus bar facing obliquely upward. In particular, in the terminal group located on the lower side of the first terminal group and the second terminal group, it is preferable that the bolt fastening surface for fastening the bus bar is directed obliquely upward. For the terminal group located on the lower side, when the bus bar is fastened, the operator is in a posture to tighten the bolt obliquely from above, so that workability is good.

  The technique disclosed in this specification is preferably applied to an electric vehicle (including a hybrid vehicle) having the above-described novel connection structure.

It is a disassembled perspective view of the electrical junction part of an inverter and a drive train. It is a perspective view when a bus-bar housing is seen from the back side. It is sectional drawing in the XZ plane of FIG. 1 (exploded view). It is sectional drawing in a XZ surface (after an assembly).

  A connection structure 100 according to an embodiment will be described with reference to the drawings. The connection structure 100 is a structure for electrically connecting a drive train 4 with a built-in motor mounted on an electric vehicle and an inverter 2 that supplies power to a motor (not shown). More specifically, it is a structure for securing a supply path of UVW three-phase AC power for driving the motor from the inverter housing to the motor built-in drive train housing. FIG. 1 shows an exploded perspective view of components constituting the connection structure 100. FIG. 2 is a perspective view of the bus bar housing 12 (described later) as viewed from the back side. 3 shows a cross-sectional view (exploded view) in the XZ plane of FIG. 1, and FIG. 4 shows a cross-sectional view (after assembly) in the XZ plane. In FIGS. 3 and 4, in order to help understanding, each part of FIG. 1 is schematically illustrated, partly simplified, and partly deformed. FIG. 1 is a view for grasping the entire connection structure from a bird's-eye view, and omits some components such as a seal material (described later). The following description will be described mainly with reference to FIGS. Further, the Z-axis of the coordinate system shown in the figure indicates the vertically upward direction.

  The inverter 2 is fixed to the upper surface of the drive train 4. Although not shown, the drive train 4 includes two motors, and the inverter 2 supplies UVW three-phase AC power to the respective motors. Therefore, six power supply lines must be connected from the inverter 2 to the drive train 4. As shown in FIG. 1, six terminal groups 3 are exposed on the side surface of the casing of the inverter 2. The six terminal groups are two sets of terminal groups of three sets of UVW three-phase AC power. Six terminal groups 5 are also exposed on the side surface of the housing of the drive train 4. The six terminal groups 5 are terminals for transmitting UVW 3-phase AC power to one motor, and the remaining three are terminals for transmitting UVW 3-phase AC power to the other motor. Hereinafter, the terminal group 3 of the inverter 2 is referred to as a first terminal group, and the terminal group 5 of the drive train 4 is referred to as a second terminal group.

  The first terminal group 3 and the second terminal group 5 are electrically connected by the same number of bus bars 15. The bus bar 15 is an elongated metal plate and is a conductive member for flowing a large current. In addition, the component shown with the code | symbol 16 is a bus-bar holder which hold | maintains six bus bars. The first terminal group 3 is fastened together with one end 15 a of the bus bar 15 by a bolt 92. The second terminal group 5 is fastened together with the other end 15b of the bus bar 15 by a bolt 93 (see FIG. 3).

  The first terminal group 3 and the second terminal group 5 are exposed in the same direction. In other words, the side surface of the inverter provided with the first terminal group 3 and the side surface of the drive train provided with the second terminal group 5 face the same direction. Since the first terminal group 3 and the second terminal group 5 face in the same direction, the operator can connect the bus bar 15 to the terminal group on the inverter side (first terminal group 3) and the terminal on the drive train side by accessing from one direction. It can be fastened with both groups (second terminal group 5). Further, since the inverter 2 and the drive train 4 are placed in the front compartment of the electric vehicle, the drive train 4 is located below the front compartment. The bolt fastening surface 5a of the second terminal group 5 located on the lower side faces obliquely upward, making it easy for an operator to fasten the bolt (see FIG. 3).

  Parts that shield the bus bar 15 fastened to both the inverter 2 and the drive train 4 are a bus bar housing 12 and a housing cover 13. The bus bar housing 12 is attached to the inverter 2 and the drive train 4 before the bus bar 15 is attached. The bus bar housing 12 has two openings 12a and 12b. The two openings 12a and 12b are open in the same direction. The first opening 12 a is attached to the inverter 2, and the second opening 12 b is attached to the drive train 4. The bus bar 15 is shielded from the outside by attaching the bus bar 15 after attaching the bus bar housing 12 and then attaching the housing cover 13 from the rear of the bus bar 15.

  On the first opening 12 a side, the peripheral end surface 12 d is joined to the casing side surface 2 a around the first terminal group 3 with the sealing material 7 interposed therebetween. The bus bar housing 12 is fastened to the side surface 2a of the inverter 2 with bolts 91 with the planar sealing material 7 interposed therebetween. On the other hand, the second opening 12b is formed in a tubular shape (cylindrical end 12e). A cylindrical surrounding portion 4 a is formed on the side surface of the drive train 4 so as to surround the second terminal group 5, and the cylindrical end portion of the bus bar housing 12 is sandwiched by the surrounding sealing portion 8 with the cylindrical sealing material 8 interposed therebetween. 12e is fitted. The cylindrical end portion 12 e is fastened to the side surface of the drive train 4 by a bolt 94. The sealing materials 7 and 8 are made of, for example, silicon rubber.

  As well shown in FIGS. 3 and 4, the first opening 12a is joined to the side surface of the inverter 2 at the end face 12d extending in the YZ plane in the drawing. The holes 12f and 12g through which the bolts 91 pass have a large clearance, and the bus bar housing 12 is limited to the vicinity of the first opening 12a. The end face 12d around the first opening 12a and the inverter 2 There is room for movement in the YZ plane while maintaining contact with the side surface 2a.

  On the other hand, in the second opening 12b, the peripheral surface of the cylindrical end 12e extending in the X direction in the drawing is fitted to the cylindrical surrounding portion 4a of the drive train 4 with the cylindrical sealing material 8 interposed therebetween. Accordingly, the bus bar housing 12 is restricted in position in the YZ direction only in the vicinity of the second opening 12b, but there is room for movement in the X direction while maintaining contact with the surrounding portion 14a in the YZ direction. have.

  When the bus bar housing 12 is attached, first, the cylindrical end portion 12e is fitted into the surrounding portion 4a of the drive train 4 (the cylindrical sealing material 8 is also fitted). At this time, the operator does not have to worry about the position on the first opening 12a side. Next, the bus bar housing 12 is pushed in the X direction until the end surface 12d contacts the side surface 2a of the inverter 2 (the flat seal material 7 is sandwiched). The operator may simply push the bus bar housing 12 (tubular end 12e). Thus, in the bus bar housing 12, one opening (first opening 12a) is in close contact with the side surface 2a of the inverter 2, and the other opening (second opening 12b) is a cylinder of the drive train 4 on its peripheral surface. Close contact with the surrounding portion 4a. The operator can easily attach the bus bar housing 12 to the inverter side and the drive train side without any gaps.

  In the connection structure described above, the inverter 2 and the drive train 4 are electrically connected using a bus bar 15 made of an elongated metal plate instead of a wire. The bus bar 15 is shielded by the bus bar housing 12 (and the housing cover 13). Compared with the case of connecting with wires, the above structure has a smaller number of parts (no connectors are required at both ends of the wires) and good workability (the shape of the bus bar 15 is fixed, so each of the bus bars Easy to fasten the end to the inverter or drive train).

  In the bus bar housing 12, one opening (first opening 12a) is joined to the side of the inverter at its end face, and the other opening (second opening 12b) is a cylindrical enclosure of the drive train 4 on the circumferential surface of the cylinder. It joins with the part 4a. With the above structure, the bus bar housing 12 can be easily positioned on both the first opening 12a side and the second opening 12b side. The connection structure 100 improves the efficiency of mounting the bus bar 15 and mounting the bus bar housing 12.

  Points to note about the connection structure of the embodiment will be described. In the embodiment, the bus bar housing 12 is in close contact with the side surface 2a of the inverter 2 at the end surface, and is in close contact with the drive train 4 on the peripheral surface of the cylinder. On the contrary, the inverter 2 may be in close contact with the peripheral surface of the cylinder, and the drive train 4 may be in close contact with the end surface.

  The electrical connection structure disclosed in this specification can be applied to an electric vehicle that includes only a wheel driving motor and does not include an engine, and a hybrid vehicle that includes both a wheel driving motor and an engine.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Inverter 2a: Terminal group exposed side surface 3: First terminal group 4: Drive train 4a: Tubular enclosure 5: Second terminal group 5a: Bolt fastening surface 7: Flat seal material 8: Cylindrical seal material 12: Bus bar Housing 12a: 1st opening part 12b: 2nd opening part 12d: End surface 12e: Cylindrical part 13: Housing cover 15: Bus bar 16: Bus bar holder 100: Electrical connection structure

Claims (6)

It is an electrical connection structure between an inverter that supplies electric power to a wheel driving motor and a drive train that houses the motor,
A first terminal group provided on one of the drivetrain housing and the inverter housing;
A second terminal group that is provided on the other side of the drive train casing and the inverter casing, and is provided to face the same direction as the first terminal group;
A bus bar connecting the first terminal group and the second terminal group;
A bus bar housing and a housing cover that cover a connection portion between the first terminal group and the bus bar to a connection portion between the second terminal group and the bus bar;
With
Busbar housing
Having first and second openings that open in the same direction;
The first opening is attached with a planar sealing material sandwiched between the end face thereof, the drive train casing surrounding the first terminal group, and the one plane of the inverter casing ,
The second opening has a cylindrical shape, and is between the cylindrical peripheral surface and the peripheral surface of the surrounding portion provided on the other side of the drive train casing and the inverter casing so as to surround the second terminal group. It is attached with a cylindrical sealing material sandwiched between,
An electrical connection structure characterized by that.   The electrical connection structure according to claim 1, wherein the inverter is fixed to the drive train.   2. The drive train includes a plurality of motors, and the first terminal group and the second terminal group include terminals for supplying power to each of the plurality of motors. Or the electrical connection structure of 2.   The first opening is attached to the casing of the inverter with a flat seal interposed therebetween, and the second opening is attached to the casing of the drive train with a cylindrical sealing material interposed therebetween. 4. The electrical connection structure according to any one of 3 above.   5. The terminal group located on the lower side of the first terminal group and the second terminal group has a bolt fastening surface for fastening the bus bar together facing obliquely upward. Electrical connection structure described in 1.   An electric vehicle having the electrical connection structure according to any one of claims 1 to 5.