JP2013055798A - Weld structure of bus bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a stress working on a welded portion between a bus bar and a coil with a simple structure.SOLUTION: In a bus bar module including a plurality of bus bars 24, the bus bars are bent into a substantially L shape in cross section or the like to be in contact with a stator coil 14 at at least two points or two surfaces. Of the bus bars 24 included in one bus bar module, at least two are bent in different directions for welding.

Description

  The present invention relates to a welded structure of a bus bar.

  A vehicle such as a hybrid vehicle or an electric vehicle generally includes a rotating electrical machine that can function as a motor and a generator. A rotating electrical machine generally includes a stator as a stator and a rotor as a rotor that rotates with a predetermined gap with respect to the stator. The stator includes a stator core and a plurality of stator coils wound around the stator core.

  The end portion of the stator coil wound around the stator core is electrically joined and connected to a bus bar made of a conductor such as a plate or a rod by welding (for example, Patent Document 1).

JP 2004-64954 A

  The present invention provides a welded structure of a bus bar that can reduce stress acting on a welded portion between the bus bar and a coil with a simple configuration.

  The present invention relates to a bus bar module including a plurality of bus bars used for connecting a stator coil mounted so as to wind a stator of a rotating electrical machine. Of the bus bars arranged along the end face of the stator, The bus bar is bent and welded to be in contact with the stator coil at two points or two or more sides, and the second bus bar different from the first bus bar is in contact with the stator coil at two points or two or more sides. It is a welded structure of a bus bar that is bent and welded in a direction different from that of the first bus bar.

  The stress acting on the welded portion between the bus bar and the coil can be reduced with a simple configuration.

It is the schematic diagram shown about the outline of the structure of the welding structure of the bus-bar in embodiment of this invention. It is sectional drawing shown about the example of arrangement | positioning of a bus-bar and a coil. It is a schematic diagram for demonstrating an example of the outline of a structure of a stator. It is the schematic diagram illustrated about the welding structure of the conventional bus bar. It is sectional drawing illustrated about arrangement | positioning of the conventional bus-bar and a coil.

  Hereinafter, it demonstrates using drawing. In the drawings, the same components are denoted by the same reference numerals, and description thereof is omitted in some cases. Further, the dimensional ratio of each member in the drawings and between the drawings does not necessarily match the actual dimensional ratio.

  A general configuration of a stator will be described with reference to FIG. The stator core 12 is disposed between a plurality of stator teeth 16 formed so as to protrude inward in a radial direction (or a rotor direction not shown) from a yoke (not shown) constituting an outer portion of the stator core 12, and the stator teeth 16. A plurality of slots 18, a stator coil 14 inserted in each of the slots 18 and mounted to be wound around the stator core 12, and the stator coil 14 for electrically connecting to a circuit outside the rotating electrical machine. Bus bar module 120.

  The stator coil 14 can be formed by, for example, a plurality of windings constituting a plurality of phase coils (for example, a three-phase coil including a U-phase coil, a V-phase coil, and a W-phase coil). As the stator coil 14, for example, coil wires having various cross-sectional shapes such as round wires, square wires, and flat wires can be applied. In the present specification, a so-called square line having a substantially rectangular cross section will be described below as an example.

  The multi-phase stator coil 14 mounted so as to be wound around the stator core 12 includes a plurality of stator teeth 16 and slots 18 at coil end portions (not shown) protruding from the end of the stator core 12 in the axial direction of the rotor (not shown). A so-called distributed winding structure arranged so as to be distributed can be formed. Further, any other winding structure such as a so-called concentrated winding structure in which each phase coil is arranged to be wound around the stator coil 14 in a concentrated manner can be applied.

  The bus bar module 120 includes an electrically insulating holder 22 such as a resin, and a plurality of conductive bus bars 124 fixed to the holder 22, and the holder 22 is fixed to the stator 10. The shape of the bus bar module 120 and the arrangement of the bus bar 124 can be appropriately designed so as to appropriately connect the stator coils 14 having the same phase in accordance with the winding structure of the stator coil 14. Are arranged along. Hereinafter, a conventional welding structure of a bus bar will be described with reference to FIGS.

  A flat bus bar 124 is welded and joined to the one end 28 of the stator coil 14 protruding from the end face of the stator and the vicinity thereof by a known welding means. In the welded structure illustrated in FIG. 4, a weld 130 is formed at the end portions of the stator coil 14 and the bus bar 124. The arrangement and shape of the welded portion 130 can be appropriately changed according to the welding technique to be applied.

  Consider a case where a rotating electric machine having a welded structure in which a stator coil and a bus bar are welded using a bus bar module is mounted on a moving body such as a vehicle and driven and / or driven. As illustrated in FIGS. 4 and 5, the stator coil 14 and the bus bar 124 are generally welded so as to be in contact with one surface. At this time, in the case where the stator coil 14 and the bus bar 124 vibrate parallel to the joint surface, stress is generated in the welded portion 130 that joins the stator coil 14 and the bus bar 124. For this reason, if an excessive stress exceeding the welding strength at the welded portion 130 occurs due to use conditions or the like, the stator coil 14 may be peeled off or dropped from the bus bar 124, for example.

  Therefore, in the embodiment of the present invention, instead of the bus bar 124, a bus bar 24 having a shape that is bent into a substantially L-shaped cross section as shown in FIG. 1 is applied. A substantially L-shaped bus bar 24 is welded to one end 28 of the stator coil 14 and the vicinity thereof by known welding means such as TIG welding or laser welding, and at least to the end portions of the stator coil 14 and the bus bar 24. A weld 30 is formed. At this time, the stator coil 14 is welded so as to contact the bus bar 24 on two surfaces.

  In the present embodiment, of the two contact surfaces of the stator coil 14 and the bus bar 24, the other contact surface that joins the stator coil 14 and the bus bar 24 even when vibrating in parallel with one of the contact surfaces. Due to the presence of the stress, the stress generated in the welded portion 30 is reduced.

  FIG. 2 exemplifies the positional relationship between the stator coil and the bus bar in order to describe the welded structure of the bus bar in the embodiment of the present invention. In FIG. 2, the stator coil and the bus bar are viewed in cross section, and the welded portions are not shown.

  2A to 2D, bus bars 24a to 24d having different arrangement relationships are welded and fixed to the stator coil 14 having a rectangular cross section. When a bus bar module is manufactured by fixing a plurality of bus bars to a holder, the shape of the bus bars is not all the same. For example, two or more of the bus bars 24a to 24d illustrated in FIGS. When selected and configured, the stress generated in the weld is further reduced. For this reason, peeling or dropping off of the stator coil from the bus bar can be more effectively prevented or suppressed.

  As described above, a plurality of bus bars can be arranged in the bus bar module. In a bus bar module in which two bus bars are arranged in parallel, for example, the bus bar 24a and the bus bar 24c shown in FIGS. 2 (a) and 2 (c), the bus bar 24b and the bus bar 24d shown in FIGS. The two bus bars formed so as to be bent in the direction are preferably arranged side by side, but the present invention is not limited to this and can be arbitrarily selected.

  In addition, when the cross-sectional shape of the stator coil has a curved surface on at least a part of the contact surface with the bus bar, such as a circle or an ellipse, a part of each bus bar is in contact with the stator coil at two points or two or more surfaces. Alternatively, it is preferable to ensure conductivity by appropriately bending or bending the whole.

  The present invention can be used in a stator in which a stator coil is connected using a bus bar.

  10 stators, 12 stator cores, 14 stator coils, 16 stator teeth, 18 slots, 22 holders, 24, 24a, 24b, 24c, 24d, 124 bus bars, 28 one end, 30, 130 welds, 120 bus bar modules.

Claims (1)

In a bus bar module including a plurality of bus bars used for connecting a stator coil mounted so as to wind a stator of a rotating electrical machine,
Of the bus bars arranged along the end face of the stator, the first bus bar is bent and welded so as to be in contact with the stator coil at two points or two or more sides, and is different from the first bus bar. A welding structure of a bus bar, wherein the welding is bent and welded in a direction different from that of the first bus bar so as to be in contact with the stator coil at two points or two or more surfaces.

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