JP4697597B2 - Busbar and motor - Google Patents

Description

  The present invention relates to a bus bar and an electric motor including the bus bar.

Conventionally, in an electric motor, terminal parts of a coil, electronic components such as sensor elements, and the like are connected to a bus bar or a circuit board provided at a coil end of an armature. For example, in Patent Document 1, in an electric motor, a terminal wire of a coil, a sensor for speed detection, and the like are connected to a substrate on which a support is attached, and a connector is joined to the substrate via the connector. Thus, the external power supply lead wire is connected to the substrate, and a signal from the speed detection sensor is taken out through the connector.
Japanese Patent Laid-Open No. 10-14153

  By the way, when the pins in the connector are directly joined to the circuit board as in the motor of Patent Document 1, the force acting on the pins when the connector is attached to and detached from the external connector is directly transmitted to the circuit board. The stress resulting from this force may cause breakage of the joint between the pin and the circuit board or cracking of the circuit board.

  The present invention has been made in view of the above problems, and in a bus bar used in an electric motor, it is possible to prevent stress from being generated in a joint portion between a metal member such as a pin in a connector and a circuit board. Thus, it is an object to prevent damage to the joint and the circuit board.

The invention according to claim 1 is a bus bar which is disposed on one side of the armature in a predetermined central axis direction in an electric motor and is connected to supply a driving current to the armature. The resin main body formed by injection molding, and a plurality of terminals for connection between the armature and the current supply unit, and a portion connecting the plurality of terminals by the insert molding at the time of injection molding is the resin A plurality of first metal members located in the body, each of which is a substantially linear metal, both end portions are exposed in the same direction of the resin main body, and one end portion is inserted by insert molding at the time of injection molding. A plurality of second metal members positioned within the resin body, and a circuit board disposed on the resin body and joined to one end of each of the plurality of second metal members , On the circuit board, the motor Is connected to a sensor for detecting the rotational position of the over data portion, said first end of said second metal member is positioned on the inner circumferential side than the other end.

The invention according to claim 2 is the bus bar according to claim 1, wherein the one end of each of the plurality of second metal members protrudes vertically from the surface of the resin body, and the circuit board. It is inserted into the hole provided in the.

According to a third aspect of the invention, a bus bar according to claim 1 or 2, wherein the plurality of end opposite to the circuit board of the plurality of second metal member is detachably an external connector Connected.

Invention of Claim 4 is a bus bar of Claim 3 , Comprising: The site | part around the said some edge part of these 2nd metal members and the said some edge part of the said resin main body is the said It is a part of the connector to be fitted with the external connector.

A fifth aspect of the present invention is the bus bar according to any one of the first to fourth aspects, wherein each of the plurality of second metal members is substantially J-shaped.

The invention according to claim 6 is an electric motor having a stator portion having an armature and a field magnet that generates torque centered on a predetermined central axis between the armature and the armature. A rotor unit, a bearing mechanism that rotatably supports the rotor unit with respect to the stator unit about the central axis, and a bus bar according to any one of claims 1 to 5 .

  In the present invention, when a wiring or the like is connected to the end of the second metal member that is opposite to the end that is bonded to the circuit board, the end that is joined to the circuit board is the force acting on this end. It is possible to prevent the joint and the circuit board from being stressed by acting on each other, and to prevent the joint and the circuit board from being damaged.

In the invention of claim 2 , the circuit board and the second metal member can be easily joined. In invention of Claim 3 , it can prevent that the force which acts on a 2nd metal member at the time of attachment or detachment of an external connector acts on a junction part or a circuit board, In invention of Claim 4 , the structure of a bus bar is provided. It can be simplified. In the invention of claim 5 , both end portions of the second metal member can be easily exposed from the same surface on the resin main body of the bus bar.

  FIG. 1 is a longitudinal sectional view of an electric motor 1 according to an embodiment of the present invention. The motor 1 is a so-called brushless motor and is used as a power steering drive source for assisting the steering of the automobile. Note that some of the parallel diagonal lines in the details of the cross section are omitted. The motor 1 includes a rotor portion 2 that is a rotating assembly, a stator portion 3 that is a fixed assembly, a substantially bottomed cylindrical housing 11 that houses the rotor portion 2 and the stator portion 3, and a bearing mechanism 4.

  When the motor 1 is actually used, an opening on the upper side of the housing 11 in FIG. Control Unit) ") 71 is attached. A pump is attached to the outside of the bottom of the housing 11, and the inside of the pump and the inside of the housing 11 are filled with oil that is a fluid for power steering. In the following description, for the sake of convenience, the opening side of the housing 11 is described as the upper side and the bottom side of the housing 11 is the lower side in the direction in which the central axis J1 extends, but the central axis J1 does not necessarily coincide with the direction of gravity.

  The housing 11 is formed as a single member by aluminum die casting, and has a substantially cylindrical tubular part 111 centered on the central axis J1, and a bottom part 112 that covers the lower end of the tubular part 111 and has an opening 1121 formed in the center. , A substantially cylindrical bearing holding portion 113 protruding from the opening 1121 along the central axis J1 toward the upper end of the cylindrical portion 111 is provided.

  The rotor portion 2 has a shaft 21 with one end (upper end) projecting from the tip of the bearing holding portion 113 around the central axis J1 and a cylindrical portion centering on the central axis J1 and is attached to the shaft 21 at the upper end of the shaft 21. Rotor core 22, field magnet 23 attached to the side surface of rotor core 22, sensor magnet 24 having an annular shape centered on central axis J 1 and attached to the outer peripheral surface at the upper end of rotor core 22, and field magnet 23 and a rotor cover 25 that covers the sensor magnet 24.

  The rotor core 22 is a magnetic body formed in a covered cylindrical shape that covers the tip of the bearing holding portion 113 by a process including pressure molding and sintering of a metal powder material, and the upper lid portion 221 is formed on the upper end of the shaft 21. Connected and the lower side is the free end. In this way, by supporting the rotor core 22 with a so-called cantilever structure, the bearing mechanism 4 is positioned in the rotor core 22 and the height (axial length) of the motor 1 is reduced. . Note that the entire bearing mechanism 4 does not have to be located inside the rotor core 22, and at least a part of the bearing mechanism 4 may only be located within the rotor core 22.

  The field magnets 23 are aggregates of a plurality of field magnet elements (so-called segment magnets) each of which is long in the direction of the central axis J1, and are arranged on the outer peripheral surface of the rotor core 22 along the circumferential direction. As the field magnet 23, for example, a sintered body containing neodymium is used.

  The armature 30 is attached to the inner peripheral surface of the cylindrical portion 111 of the housing 11 so as to face the field magnet 23, and the central axis of the armature 30 coincides with the central axis J 1 of the shaft 21. The armature 30 is arranged radially from the inner peripheral surface of the annular portion (so-called core back) of the core 31 made of a magnetic material with the tip toward the central axis J1 and centering on the central axis J1 (that is, the housing 11). A plurality of teeth (refer to reference numeral 311 in FIG. 2) extending from the inner peripheral surface toward the shaft 21 and the field magnet 23, an insulator 32 covering the plurality of teeth, and a plurality of teeth conducting a conductor in multiple layers from above the insulator 32 The coil 35 provided by winding is provided. The coil 35 is formed by winding a conductive wire on the outer periphery of the teeth and the insulator 32 in the vertical direction (the direction of the central axis J1).

  A bus bar 50 connected to supply a driving current to the coil 35 of the armature 30 is disposed on the upper side, which is one side of the armature 30 with respect to the central axis J1 direction. The bus bar 50 is also connected to the ECU 71. The bus bar 50 includes a substantially annular resin main body 51 formed by resin injection molding, and a plurality of (four in the present embodiment) circles stacked in the resin main body 51 at intervals in the direction toward the central axis J1. An arc-shaped wiring board 512, a plurality of connector pins 513 each made of a substantially linear metal having rigidity, and a circuit board 52 disposed on the resin body 51 are provided.

  In the motor 1, the stator portion 3 fixed in the housing 11 with the armature 30, the bus bar 50 and the like as main portions is configured, and the bearing mechanism 4 is held inside the bearing holding portion 113 of the housing 11. The bearing mechanism 4 is a pair of bearings 41 and 42 arranged along the central axis J1, and the shaft 21 of the rotor portion 2 is supported by the pair of bearings 41 and 42 in the bearing holding portion 113. Thus, the rotor part 2 is supported so as to be rotatable relative to the stator part 3 around the central axis J1. Then, a drive current is supplied to the armature 30 via the bus bar 50, whereby a torque centered on the central axis J1 is generated between the field magnet 23 and the armature 30, and the rotor portion 2 rotates. To do.

  On the side of the resin body 51 of the circuit board 52, three hall elements 53 that are sensors for detecting the orientation of the rotor core 22 (that is, the rotational position of the rotor portion 2) together with various electronic components protrude downward. The Hall element 53 is connected to the sensor holder 54 described later. The hall element 53 is disposed outside the sensor magnet 24 with respect to the central axis J <b> 1, and the sensor magnet 24 faces the hall element 53. The sensor magnet 24 is magnetized in the same manner as the field magnet 23, and the rotational position of the field magnet 23 is indirectly detected by the Hall element 53 detecting the magnetic field from the sensor magnet 24. Detected. Then, the drive current to the armature 30 is controlled based on the detection result.

  FIG. 2 is an exploded perspective view showing main components of the stator unit 3. In FIG. 2, only the core 31 is shown for the armature 30, but actually, when the bus bar 50 is attached to the upper end of the armature 30, the teeth 311 of the core 31 are covered with the insulator 32, and further the insulator An armature 30 in which a coil 35 is formed by winding a conductive wire from above 32 is prepared (see FIG. 1).

  As shown in FIG. 2, the wiring board 512 in the bus bar 50 (see FIG. 1) includes a plurality of terminals 5121 for connection to the armature 30 and a plurality of flat terminals for connection to an external current supply unit. 5122, and a part that connects between the terminal 5121 and the flat terminal 5122 is resin-molded so as to be positioned in the resin main body 51 by insert molding at the time of injection molding. The bus bar 50 is also provided with a plurality of connector pins 513 for connection to the outside, and a part between both end portions 513a and 513b of each connector pin 513 is located in the resin main body 51 by insert molding at the time of injection molding. The resin is molded as follows. As described above, two types of metal members are roughly arranged in the resin main body 51 of the bus bar 50, and a part of the plurality of wiring boards 512 that are a plurality of first metal members and a plurality of second metal members. A part of the plurality of connector pins 513 is covered with the resin main body 51 and is fixed while being electrically insulated from each other.

  In the stator portion 3, the bus bar 50 is electrically connected to the armature 30 by connecting the lead wire from the coil 35 (not shown) to the terminal 5121 on the outer periphery by caulking. At this time, the plurality of leg portions 514 provided on the outer periphery of the resin body 51 abut on the upper surface of the core 31, and the protrusions formed at the tips of the leg portions 514 are engaged with the vertical grooves on the outer peripheral surface of the core 31. By combining, the position of the bus bar 50 with respect to the core 31 is determined.

  FIG. 3 is an enlarged longitudinal sectional view showing a part of the bus bar 50. In the bus bar 50, each connector pin 513 is substantially J-shaped, and both end portions 513a and 513b are exposed upward from the resin main body 51. Of the both ends of each connector pin 513, an end portion (hereinafter referred to as “substrate-side end portion”) 513a joined to the circuit board 52 is a circuit board of the resin main body 51 as shown in FIGS. An end portion (hereinafter referred to as “connector side end portion”) 513 b that protrudes perpendicularly from the surface facing the pin 52 and is opposite to the circuit board 52 of the connector pin 513 is provided so as to protrude upward from the resin body 51. It protrudes further upward from the tip of the protruding portion 515 formed.

  Specifically, the protrusions 515 are provided with connector protrusions 515a protruding upward around the plurality of connector side end portions 513b, and the plurality of connector side end portions 513b protrude from the tip ends of the connector protrusions 515a. To do. An external connector 711 that outputs a signal to the ECU 71 (see FIG. 1) is detachably connected to the connector 510 including the connector protrusion 515a and the connector side end 513b. That is, in the bus bar 50, a portion around the connector-side end portion 513 b of the resin main body 51 is a part of the connector 510 to be fitted with the external connector 711. A signal output to the ECU 71 is generated by an electronic component mounted on the circuit board 52 based on a signal from the hall element 53.

  As shown in FIG. 2 and FIG. 3, an arc-shaped recess 518 in which an arc-shaped sensor holder 54 made of resin is accommodated is formed on the inner peripheral surface of the resin main body 51, and the Hall element 53 is a circuit board. 52, the Hall element 53 is inserted and held in each recess 541 of the sensor holder 54, and after the terminals of the Hall element 53 are inserted into holes formed in the lands on the circuit board 52, The sensor holder 54 is fixed to the surface of the circuit board 52 on the resin body 51 side. As shown in FIG. 2, the sensor holder 54 is fixed to the circuit board 52 by thermal welding in which the protrusions 542 of the sensor holder 54 are inserted into the holes 521 of the circuit board 52 and the protrusions 542 are heated and melted to be crushed. Done. Thereafter, the terminals of the Hall element 53 are joined to the circuit board 52 by soldering.

  The circuit board 52 is fixed to the resin body 51 after the sensor holder 54 is attached to the circuit board 52. First, the sensor holder 54 is fitted into the recess 518, and is provided on the upper surface of the resin body 51. Two resin protrusions 511 are inserted into the holes 522 of the circuit board 52, and the board-side end parts 513 a of the plurality of connector pins 513 are inserted into the holes 523 provided in the circuit board 52. Then, the circuit board 52 is firmly fixed to the resin main body 51 by heat welding in which the protrusions 511 are heated and melted and crushed, and the board-side end 513a is joined to the circuit board 52 by soldering. In the bus bar 50, the board side end 513a protrudes perpendicularly from the surface of the resin body 51, so that the circuit board 52 and the connector pin 513 can be easily joined.

  Although the structure of the motor 1 has been described above, in the bus bar 50 of the motor 1, a part between the board side end portion 513 a and the connector side end portion 513 b of the connector pin 513 is positioned in the resin main body 51. Resin molding is performed, and each substrate side end 513a and the circuit board 52 are joined. Thereby, when the external connector 711 is connected to the connector side end 513b, the force acting on this end is absorbed by the resin main body 51 and does not act on the board side end 513a. As a result, it is possible to prevent stress from being generated in the joint portion of the board side end portion 513a and the circuit board 52, and damage to the joint portion and the circuit board 52 is prevented. Further, by making the connector pin 513 substantially J-shaped, the circuit board 52 is arranged not next to the position along the connection direction of the external connector 711 (that is, below the connector-side end 513b) but next to the connector 510. Therefore, the force acting on the connector pin 513 when the external connector 711 is attached / detached is efficiently absorbed by the resin main body 51, and the force acting on the joint portion of the board side end 513a and the circuit board 52 can be further prevented. .

  Further, since each connector pin 513 is substantially J-shaped, the board-side end 513a can be easily exposed from the same surface on the resin body 51, and the connector pin 513 and the circuit board 52 can be easily removed. Can be joined.

  Further, in the bus bar 50, a portion around the connector side end 513b of the resin main body 51 (connector protrusion 515a) and the connector side end 513b are part of the connector 510 to be fitted to the external connector 711 (actually The connector 510 is further provided with packing or the like, but the connector protrusion 515a and the connector side end 513b may constitute substantially the entire connector 510. Therefore, it is necessary to separately attach the connector to the resin main body 51. Therefore, the structure and assembly of the bus bar 50 can be simplified.

  As described above, the motor 1 is used as a power source of a pump that sends out oil as a fluid, and the housing 11 is filled with oil. Therefore, each terminal of the bus bar 50, the Hall element 53, and other electronic devices are used. A sealant is appropriately applied to the joint between the component and the circuit board 52.

  4 and 5 are longitudinal sectional views showing other examples of the bus bar, and correspond to FIG. In the bus bar 50a shown in FIG. 4, both ends 516a and 516b of the pin 516 (corresponding to the connector pin 513 in FIG. 3) are exposed from the resin main body 51 and connected to the circuit board 52 as in the case of FIG. A flexible lead wire 517 is connected to the end portion 516b opposite to the end portion 516a using solder. Also in the bus bar 50a, when connecting the wiring or the like, specifically, the lead wire 517 is joined to the end portion 516b, or a connector (not shown) connected to the opposite side of the lead wire 517 is attached to or detached from the ECU 71. At this time, the force acting on the end portion 516b is absorbed by the resin main body 51, and it is possible to prevent the stress from being generated in the joint portion between the end portion 516a of the pin 516 and the circuit board 52. Thus, the pin provided as the second metal member in the resin main body 51 may not be used as the pin of the fitting type connector. Further, the second metal member may not be pin-shaped as long as it is substantially linear, and may be, for example, a stranded metal having poor rigidity.

  FIG. 5 is a vertical cross-sectional view illustrating a bus bar 50 b including a substantially L-shaped connector pin 513. Since the connector pin 513 shown in FIG. 5 is substantially L-shaped, the board-side end portion 513a protrudes vertically from the upper surface of the resin body 51, but the connector-side end portion 513b protrudes from the outer surface of the resin body 51. The connector-side end portion 513b and the surrounding portion become a part of the connector 510 fitted to the external connector 711. Thus, the connector pin 513 that is the second metal member in the resin main body 51 may have various shapes. For example, the connector pin 513 may have a linear shape.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible.

  For example, in the motor 1, the resin main body 51 of the bus bar 50 is annular, but the present invention is not limited to this, and the resin main body may be arc-shaped or disk-shaped.

  In the above embodiment, only the wiring board 512 and the connector pin 513 are molded as metal members by insert molding in the resin main body 51, but other metal members may be further molded by insert molding.

  Further, the circuit board 52 may be provided other than the upper surface of the resin main body 51, for example, may be attached to the lower surface of the resin main body 51.

  The bearing mechanism 4 may have a bearing other than the pair of bearings 41 and 42, for example, the shaft 21 may be supported by an oil-impregnated sleeve. Moreover, the shaft 21 does not need to be supported by a cantilever structure, and may be supported by a both-end support structure. That is, the bearing mechanism that rotatably supports the shaft 21 with respect to the housing 11 may be separated from the rotor core 22 in the vertical direction.

  The motor 1 may be used for an electric brake system, an electromagnetic suspension, and a transmission system in addition to the electric power steering of an automobile, and may be used for various systems in which a motor including a circuit board on a bus bar is used.

1 is a longitudinal sectional view of an electric motor according to an embodiment of the present invention. It is a perspective view which decomposes | disassembles and shows the main components of a stator part. It is a longitudinal cross-sectional view which expands and shows a part of bus bar. It is a longitudinal cross-sectional view which shows the other example of a bus bar. It is a longitudinal cross-sectional view which shows the other example of a bus bar.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Rotor part 3 Stator part 4 Bearing mechanism 23 Field magnet 30 Armature 50, 50a, 50b Bus bar 51 Resin body 52 Circuit board 53 Hall element 512 Wiring board 513 Connector pin 513a Board side edge part 513b Connector side edge part 516 pin 516a, 516b end 517 lead wire 523 hole 711 external connector 5121 terminal 5122 flat terminal J1 central axis

Claims (6)

A bus bar disposed on one side of the armature with respect to a predetermined central axis direction in an electric motor, and connected to supply a driving current to the armature,
A resin body formed by resin injection molding;
A plurality of first metals having a plurality of terminals for connection with the armature and the current supply unit, and parts connecting the plurality of terminals are located in the resin body by insert molding at the time of the injection molding. Members,
Each is a substantially linear metal, both end portions are exposed in the same direction from the resin body, and a plurality of second portions in which a part between the both end portions is located in the resin body by insert molding at the time of the injection molding. A metal member;
A circuit board disposed on the resin body and bonded to one end of each of the plurality of second metal members,
A sensor that detects the rotational position of the rotor portion of the motor is connected to the circuit board,
The bus bar characterized in that the one end portion of the second metal material is located on the inner peripheral side with respect to the other end portion . The bus bar according to claim 1 ,
The bus bar, wherein the one end portion of each of the plurality of second metal members protrudes perpendicularly from the surface of the resin main body and is inserted into a hole provided in the circuit board. The bus bar according to claim 1 or 2 ,
A bus bar, wherein a plurality of ends of the plurality of second metal members opposite to the circuit board are detachably connected to an external connector. The bus bar according to claim 3 ,
Sites around the plurality of end portions of the plurality of second metal members and the plurality of end portions of the resin main body are part of a connector fitted to the external connector. Busbar. A bus bar according to any one of claims 1 to 4 ,
Each of the plurality of second metal members is substantially J-shaped. An electric motor,
A stator portion having an armature;
A rotor portion having a field magnet that generates torque centered on a predetermined central axis with the armature;
A bearing mechanism that rotatably supports the rotor portion with respect to the stator portion around the central axis;
Busbar according to any one of claims 1 to 5 ,
A motor comprising:

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