JP6459680B2 - Busbar connection structure - Google Patents

Description

  The present invention relates to a connection structure when two bus bars are connected by welding.

  When connecting bus bars connected to an electrical device through which a large current flows, both bus bars are bent in the same direction to contact both bus bars, and then both bus bars are welded and connected (for example, Patent Document 1).

  Since there are many gaps between the bus bars when they are brought into contact with each other, it is necessary to bring the bus bars into close contact when welding. At this time, both bus bars are brought into close contact with each other by using a jig such as a clamp in order to suppress an increase in electrical resistance at the connection site.

JP 2011-8938 A

  However, since the bus bar that handles a large current has high rigidity and is difficult to be deformed, there is a problem in that the adhesion between the contact surfaces of both bus bars does not increase.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a bus bar connection structure capable of improving the adhesion of the contact surface of the bus bar. There is.

In order to achieve the above object, the present invention forms a notch portion on at least one contact surface side of the first bus bar and the second bus bar. The notch is formed at the outer corner of at least one bent portion of the first bus bar and the second bus bar. Then, the contact surfaces of the first bus bar and the second bus bar are brought into contact with each other, and further, the respective contact surfaces are welded and connected.

  In the bus bar connecting portion structure according to the present invention, since the notch is formed on the contact surface side of the first bus bar or the second bus bar, the adhesion of the contact surface of each bus bar can be improved.

It is explanatory drawing which shows typically the connection structure of the bus-bar which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows typically the mode at the time of welding two bus bars using the connection structure of the bus bar which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the comparative example with respect to the connection structure of the bus-bar which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows typically the connection structure of the bus-bar which concerns on 2nd Embodiment of this invention. It is explanatory drawing which shows typically the connection structure of the bus bar which concerns on the modification of 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Description of First Embodiment]
FIG. 1 is an explanatory view schematically showing a bus bar connection structure according to the first embodiment of the present invention. In FIG. 1, as an example, a cross-sectional view of a connection structure of a bus bar B1 connected to a power module 11 mounted on an electric vehicle and a bus bar B2 connected to a smoothing capacitor 12 is shown.

  As shown in FIG. 1, the bus bar B1 (first bus bar) connected to the power module 11 has a flat plate shape and extends toward the smoothing capacitor 12 side. Furthermore, it bends substantially at right angles in the middle, and the whole forms an “L” shape.

  Similarly, the bus bar B2 (second bus bar) connected to the smoothing capacitor 12 has a flat plate shape and extends toward the power module 11 side. Further, it is bent substantially at a right angle (in the same direction as the bus bar B1) in the middle thereof, and the whole forms an “L” shape.

  As shown in FIG. 1, the surface of the bus bar B1 facing the bus bar B2 (outside of the bus bar B1) is the contact surface b1 during welding, and the surface of the bus bar B2 facing the bus bar B1 (outside of the bus bar B2) ) Is the contact surface b2 during welding. That is, the bus bar B1 and the bus bar B2 are mechanically and electrically connected by welding with the contact surfaces b1 and b2 being in contact with each other.

  In addition, a notch 13 having a rectangular cross-sectional shape is provided at an appropriate position on the contact surface b1 formed on the bus bar B1 (on the contact surface side of the bus bar B1, in the contact surface). The notch 13 is continuously formed in the depth direction (a direction orthogonal to the paper surface in the drawing). In addition, this invention is not limited to this, The notch part 13 may be intermittently formed toward the depth direction.

  In general, since a large current flows through the power module 11 and the smoothing capacitor 12, a material having high rigidity and being difficult to elastically deform is used as the material of each of the bus bars B1 and B2. However, since the bus bar B1 has a structure that is easily elastically deformed and plastically deformed in the vicinity of the notch 13 by forming the above-described notch 13, the adhesion between the two bus bars B1 and B2 is improved as will be described later. It can be increased.

  Next, a procedure for welding the bus bars B1 and B2 configured as described above and connecting them will be described with reference to the schematic diagram shown in FIG. As shown in FIG. 2, when connecting the two bus bars B <b> 1 and B <b> 2, an external force is applied to each bus bar B <b> 1 and B <b> 2 using the clamp 21 so as to bring them into close contact. At this time, since the notch 13 is formed in the contact surface b1 of the bus bar B1 as described above, the contact surface b1 and the contact surface b2 are improved in adhesiveness due to elastic deformation or plastic deformation. The space generated in the process can be reduced or completely eliminated.

  Then, a gap is left between the clamps 21, and the two bus bars B1 and B2 are welded by the torch 22 using this gap. As a welding method, fusion welding methods such as arc welding, laser beam welding, and electron beam welding can be used. In the case of laser beam welding or electron beam welding, the arrangement of the clamp 21 is determined so that the beam is not blocked by the clamp 21.

  In this way, since welding connection can be performed in a state in which the adhesion between the two bus bars B1 and B2 is increased, it is possible to perform connection without increasing the resistance value of the connection portion and maintaining high rigidity. Become.

  Moreover, in this embodiment, the notch part 13 is formed in the contact surface b1. In other words, the notch 13 is formed outside the bus bar B1 (on the side facing the bus bar B2). Therefore, as shown in FIG. 3, which is a comparative example, the elastic secondary moment of the notch 13 (hardness of deformation with respect to the bending moment) is increased as compared with the case where the notch 13a is provided inside the bus bar B1. And mechanical strength can be improved.

  In the present embodiment, the example in which one notch 13 is formed in the contact surface b1 (in the contact surface) of the bus bar B1 (first bus bar) has been described, but the present invention is not limited to this. Two or more notch portions 13 may be provided. Moreover, it is good also as a structure which forms a notch in both contact surface b1, b2 of bus-bar B1, B2. Furthermore, the shape of the notch 13 is not limited to a rectangular shape. For example, it may be an arc shape.

[Description of Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 4 is an explanatory view showing a connection structure according to the second embodiment. The bus bar B1 shown in FIG. 4 is different from the bus bar B1 shown in FIG. 1 in the position where the notch is formed. Since the other configuration is the same as that of FIG. 1 shown in the first embodiment, the same reference numerals are given and description of the configuration is omitted.

  As shown in FIG. 4, in the second embodiment, a cutout portion 23 having a rectangular cross section is formed at the outer corner (the contact surface side of the bus bar B1) of the bent portion of the bus bar B1. Then, similarly to the first embodiment described above, the bus bars B1 and B2 are connected to each other by using a fusion welding method such as arc welding, laser beam welding, or electron beam welding.

  Therefore, similarly to the first embodiment described above, since the welding connection can be performed in a state where the adhesion between the two bus bars B1 and B2 is improved, the resistance value of the connection portion is not increased, and the rigidity is high. It is possible to connect while maintaining

  Furthermore, by forming the notch 23 at the corner, the stress concentration on the power module 11 or the smoothing capacitor 12 due to external force can be reduced. Further, the bending of the bus bar B1 can be facilitated.

[Description of Modification of Second Embodiment]
Next, a modification of the second embodiment will be described. FIG. 5 is an explanatory view showing a connection structure according to a modification of the second embodiment. The bus bar B1 shown in FIG. 5 is different from the bus bar B1 shown in FIG. That is, in the connection structure shown in FIG. 5, the notch surface which is a cross section of the notch 24 formed at the corner of the bus bar B1 has an arc shape. The other configuration is the same as that of the second embodiment shown in FIG.

  And in the connection structure which concerns on a modification, the cross section of the notch part 24 is made into circular arc shape, Therefore The stress concentration at the time of external force being applied with the clamp 21 can be avoided, and the rigidity as a whole is improved. It becomes possible.

  As mentioned above, although the connection part structure of the bus bar of this invention was demonstrated based on embodiment of illustration, this invention is not limited to this, The structure of each part is set to the thing of the arbitrary structures which have the same function. Can be replaced.

11 power module 12 smoothing capacitor 13, 13a, 23, 24 notch 21 clamp 22 torch B1 bus bar B2 bus bar b1 contact surface b2 contact surface

Claims (2)

A bus bar connecting portion structure in which the first bus bar and the second bus bar are bent in the same direction, the contact surfaces of each bus bar are opposed to each other, and the contact surfaces are connected by welding.
At least one notch is formed on at least one contact surface side of the first bus bar and the second bus bar ,
The bus bar connection structure according to claim 1, wherein the notch is formed at an outer corner of at least one bent portion of the first bus bar and the second bus bar . The bus bar connecting portion structure according to claim 1, wherein the notched portion has a circular arc shape .

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