JP2018067432A - Aluminum alloy material for bus bar, bus bar and manufacturing method of bus bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy material for bus bar having conductive performance required as a bus bar and high production yield by conducting an edge wise flexure processing, and the bus bar having the aluminum alloy material for bus bar and a manufacturing method of the bus bar.SOLUTION: A bus bar 100 has a linear part 11, a recess 12 and a projection 13. The recess 12 and the projection 13 form an edge wise flexure processing part which is a bent part. The edge wise flexure processing part having the recess 12 and the projection 13 is formed one or more. The recess 12 is formed with a prescribed radius Ri. Minimum distance t2 from an edge part of the recess 12 to an edge part of the projection 13 has distance of sheet width t1 of the linear part 11 or more. Area A13 of the projection area formed by the recess 13 and a virtual line of the linear part 11 is same as or more than area A12 of a recess area formed by the recess 12 and the virtual line of the linear part 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an aluminum alloy material for bus bars, a bus bar, and a method for manufacturing the bus bar.

  Conventionally, a bus bar made of a pure copper plate having excellent conductivity and strength is used as a conductive member for wiring such as a PCU (Power Control Unit) in a transportation machine such as a bullet train, a linear motor car, a hybrid vehicle, and an electric vehicle. It has been. In recent years, bus bars made of aluminum alloy that are less expensive than copper and have a small specific gravity have been studied.

  However, when a bus bar having a complicated shape is produced by punching with a press, there is a problem that a large amount of punching waste is generated and the yield deteriorates.

  As a countermeasure against such a problem, there has been proposed a bus bar (Patent Document 1) that is formed into a desired shape using edgewise bending instead of the conventional press punching. In order to improve edgewise bending workability, a method of forming a recess in an edgewise bending portion (Patent Document 2) has also been proposed.

International Publication No. 2012/117650 Japanese Patent Laying-Open No. 2015-228476

  When aluminum alloy is applied to bus bars, aluminum alloy has lower conductivity than copper, so it needs to have a larger cross-sectional area, and wide bus bars must be used due to space constraints to accommodate bus bars There is a case. However, when the edgewise bending process is applied to such a wide bus bar, there is a problem that the edgewise bending outer peripheral portion is cracked due to the low bending processability of the aluminum alloy.

  The present invention has been made in view of such a background, and provides an aluminum alloy material for a bus bar having a conductive performance required as a bus bar and having a high product yield by performing edgewise bending. Objective. It is also an object of the present invention to provide a bus bar including the aluminum alloy material for bus bars and a method for manufacturing the bus bar.

In order to achieve the above object, an aluminum alloy material for bus bars according to the first aspect of the present invention,
An aluminum alloy material for a bus bar that has a straight portion and is edgewise bent,
A recess formed in a portion corresponding to a bending inner periphery of the edgewise bending process;
A convex portion formed on a portion corresponding to a bending outer peripheral portion of the edgewise bending process,
It is characterized by that.

The concave portion has an arc shape having a radius equal to or larger than the inner bending radius of the edgewise bending portion,
The minimum distance from the edge of the concave portion to the edge of the convex portion is a distance greater than or equal to the width of the straight portion.
It is good as well.

The area of the convex part is equal to or greater than the area of the concave part,
It is good as well.

The convex portion includes a plurality of individual convex portions.
It is good as well.

The arc portion circumferential length of the convex portion is longer than the arc portion circumferential length of the concave portion,
It is good as well.

In order to achieve the above object, the bus bar according to the second aspect of the present invention is:
Provided with the above aluminum alloy material for bus bars,
It is characterized by that.

In order to achieve the above object, a method of manufacturing a bus bar according to the third aspect of the present invention includes:
Prepare a bus bar material with a straight part and an edgewise bent part bent by a concave part and a convex part,
With the concave portion on the inside and the convex portion on the outside, edgewise bending is performed in the edgewise bending portion,
It is characterized by that.

  Since the said aluminum alloy material for bus bars has provided the recessed part previously in the edgewise bending inner peripheral part, it can perform an edgewise bending process easily and can raise a yield.

  In addition, since the bus bar aluminum alloy material is provided with a convex portion in the edgewise bending outer peripheral portion in advance, even when a concave portion is provided in the edgewise bending inner peripheral portion, the cross-sectional area of the convex portion and the concave portion is By having substantially the same cross-sectional area as that of the straight portion, it has excellent conductivity after edgewise bending.

  As described above, according to the present invention, an aluminum alloy material for a bus bar having a conductive performance required for a bus bar and having a high product yield can be obtained by performing edgewise bending. Moreover, the bus bar provided with the said aluminum alloy material for bus bars, and the manufacturing method of a bus bar are also obtained.

(A) It is a schematic diagram which shows a part of bus bar concerning 1st Embodiment of this invention, (b) is sectional drawing cut | disconnected by the XX line of (a). It is a schematic diagram which shows the edgewise bending part of a bus bar. It is a schematic diagram which shows a part of bus bar which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows a part of bus bar which concerns on 3rd Embodiment of this invention. It is a schematic diagram which shows a part of bus bar which concerns on 4th Embodiment of this invention. It is a schematic diagram which shows a part of bus bar which concerns on 5th Embodiment of this invention.

  Hereinafter, the present invention will be described in detail.

(First embodiment)
As shown in FIGS. 1A and 1B, the bus bar 100 according to the first embodiment is basically formed in a flat bar shape by the straight portion 11. However, at one or more predetermined portions, as shown in the figure, arc-shaped concave portions 12 and convex portions 13 are provided in advance and bent.

  The bus bar 100 is manufactured by punching into a shape shown in FIG. Since aluminum alloys used as bus bars are required to have strength, conductivity, and bending workability, aluminum alloys such as 1000 series and 6000 series are preferably used.

  The concave portion 12 and the convex portion 13 are formed when the short side surface 14 of the flat cross section of the bus bar 100 becomes the concave portion (14a) or the convex portion (14b). Therefore, Fig.1 (a) has shown the long side surface 15 among the rectangular cross sections.

  The boundary between the straight line portion 11 and the circular arc portion (the concave portion 12 or the convex portion 13) is smoothly rounded. The boundary may have a shape that changes more gently than in the case shown in FIG. The same applies to the structures in and after the second embodiment described later (a part of the illustration is simplified).

  The recess 12 is formed with a predetermined radius Ri. The convex portion 13 is formed with a radius Ro that is equivalent to the concave portion 12 or takes into account the shape of the bus bar 100 when edgewise bending (described later) is performed. The center of the convex portion 13 is shifted to the right side in the figure by a distance d compared to the center of the concave portion 12. By shifting the center positions from each other in this way, the edgewise bending process can be facilitated and a desired shape can be easily obtained after the process. Depending on the size of each part of the bus bar 100, the edgewise bending method, and the like, the direction of deviation of the center position may be opposite to that in the example of FIG.

  As will be described later, since the edgewise bending inner portion finally has an arc shape, it is preferable in terms of formability to make the shape an arc shape in advance.

  Here, the plate width of the straight portion 11 is t1, and the width of the edgewise bending portion which is a bent portion formed by the concave portion 12 and the convex portion 13 (the minimum from the edge of the concave portion 12 to the edge of the convex portion 13). When the distance) is t2, it is preferable that t2 ≧ t1. This is because the bus bar 100 is used as a conductive member, so that necessary conductivity is obtained.

  In addition, each virtual straight line is drawn in FIG. 1 at both edges in the width direction of the straight line portion 11 in the edgewise bent portion, and the area of the concave region formed between the concave portion 12 and the virtual straight line is A12. When the area of the convex region formed between the portion 13 and the imaginary straight line is A13, A13 is preferably equal to or greater than A12. This is because the area of the protrusions must be equal to or greater than the area of the recesses in order to ensure a sufficient cross-sectional area over the entire bend after bending. More preferably, the area of the convex part 13 is larger than the area of the concave part 12 (A13> A12).

  Further, it is preferable that the arc portion circumferential length of the convex portion 13 is longer than the arc portion circumferential length of the concave portion 12. When edgewise bending is performed, the outside of the processed portion extends and the inside shrinks. By providing the convex portion 13 and the concave portion 12, such extension and shrinkage can be suppressed. At this time, in order to suppress a decrease in the cross-sectional area of the conductor due to the edgewise bending process, the convex portion 13 is formed in advance so as to have a longer circumferential length than the concave portion 12.

  Next, the bending form of the bus bar 100 will be described with reference to FIG.

  In the present embodiment, the bus bar 100 is subjected to edgewise bending. Edgewise bending is a short-side surface of an aluminum alloy (including pure aluminum) that has one short side as an inner peripheral surface and the other short side as an outer peripheral surface. This is a process of bending a flat conductor by a predetermined angle by applying a bending load to the side. On the other hand, the flatwise bending process is such that one long side surface of the aluminum alloy rectangular conductor is an inner peripheral surface, and the other long side surface is an outer peripheral surface, and the outer peripheral surface side to the inner peripheral surface side. This is a process of bending a flat conductor by a predetermined angle by applying a bending load.

  In the example shown in FIG. 2, the bus bar 100 is bent 90 ° with the concave portion 12 as an inner side and the convex portion 13 as an outer side. What is indicated by a two-dot chain line in the figure is an inner bending radius Rb when a simple flat conductor is assumed. Assuming that Rb is formed in an arc shape from the position of the boundary portion between the straight portion 11 and the concave portion 12, Rb is obtained from the size of the concave portion 12 and the angle between the straight portions 11 on both sides of the concave portion 12.

  The portion of the concave portion 12 is deformed by compression and becomes smaller in inner diameter due to bending, but is equal or slightly larger than the inner bending radius Rb. Moreover, the part of the convex part 13 receives a tensile force by bending. In the example of FIG. 2, the outer diameter of the convex portion 13 before the bending process is determined in consideration of the convex portion 13 not protruding during bending.

  As described above, in the edgewise bent portion of the bus bar 100 according to the present embodiment, the concave portion 12 is provided in advance on the inner periphery of the bend before the edgewise bending. Thereby, the effect which reduces the distortion which generate | occur | produces in a bending outer peripheral part is acquired.

  Further, a convex portion 13 is provided in advance on the outer periphery of the bending in the edgewise bending portion before the edgewise bending. Thereby, the effect which supplements the cross-sectional area reduced by formation of the recessed part 12 is acquired, and required electroconductivity can be acquired.

  The bus bar 100 is required to have a wide width in order to ensure conductivity, and the inner bending radius Rb is required to be small so as to be within a narrow range. For this reason, when molding an inner bending radius Rb smaller than the plate width t1 without cracking, it is preferable to form the concave portion 12 and the convex portion 13. For example, in the case of a simple flat-conductor edgewise bending, even if a crack or constriction occurs in the outer periphery of the bend around Rb / t1 = 1, Rb / t1 can be made smaller by forming the recess 12 and the protrusion 13. Is possible.

  In addition, according to the present embodiment, the concave portion 12 and the convex portion 13 are provided only in a portion where the edgewise bending is scheduled in the substantially straight portion 11. Thereby, compared with the case where the shape corresponding to the shape after the edgewise bending is formed from the plate material by punching, the yield in manufacturing the bus bar 100 can be improved in the present embodiment.

(Second Embodiment)
As with the first embodiment, the bus bar 100 according to the second embodiment is provided with the concave portion 12 and the convex portion 13 in the edgewise bending portion. However, the second embodiment is different from the first embodiment in that the center of the concave portion 12 (the valley) and the center of the convex portion 13 (the mountain) coincide.

  As shown in FIG. 3, the center of the convex portion 13 is coincident with the center of the concave portion 12 in the horizontal direction in the drawing. As described above, the positions of the center of the recess 12 and the center of the protrusion 13 are combined with the first embodiment according to the size of each part such as the plate width t1 and the inner bending radius Rb of the bus bar 100 and the edgewise bending method. Relationships can be taken arbitrarily.

(Third embodiment)
Hereinafter, the example of the shape of the convex part 13 is shown from 3rd Embodiment to 5th Embodiment.

  In the third embodiment shown in FIG. 4, one convex portion 13 having a radius Ro is provided. Although not shown, the recess 12 is formed in the same manner as in FIG. The outer diameter of the convex portion 13 in FIG. 4 and the inner diameter of the concave portion 12 in FIG. 1 are not necessarily the same. Therefore, the example of FIG. 4 is equivalent to the configuration of FIG.

(Fourth embodiment)
In 4th Embodiment shown in FIG. 5, the convex part 13 becomes a form where the individual convex parts 13a, 13b, and 13c of radius Ro are located in a line. Although not shown, the recess 12 is formed in the same manner as in FIG. The outer diameters of the individual convex portions 13a, 13b, and 13c in FIG. 4 and the inner diameter of the concave portion 12 in FIG. 1 do not necessarily have to be the same, and the concave portion 12 has a width that substantially corresponds to the width of the convex portion 13 shown in the figure. It is formed. Since deformation tends to concentrate on the arc end of the convex portion 13, the deformation can be dispersed by arranging a plurality of arcs as in the present embodiment.

(Fifth embodiment)
In 5th Embodiment shown in FIG. 6, the convex part 13 becomes a form where the individual convex parts 13a, 13b, and 13c are located in a line like FIG. This embodiment is different from FIG. 5 in that the radius Ro is not only on the mountain side of the individual convex portions 13a, 13b, 13c, but also on the valley side between the individual convex portions 13a, 13b and between the individual convex portions 13b, 13c. It is that you are. Thereby, a waveform like a substantially sine wave is formed from the individual convex part 13a to the individual convex part 13c. 6 can also disperse the deformation by arranging a plurality of arcs as in the case of FIG. 5, and can further enhance the effect including the above-mentioned arcs on the valley side.

  The present invention is not limited to the above-described embodiments and specific examples, and various modifications and applications are possible.

  The inner bending radius Rb of the edgewise bending portion may be smaller than the width (width of the long side surface 15) t1 of the flat conductor cross section. As the inner bending radius Rb is smaller with respect to the width t1 of the rectangular conductor cross section, cracks are more likely to occur during edgewise bending, so the effect of forming the recess 12 becomes more prominent.

  The recess 12 may have an arc shape having a radius equal to or larger than the inner bending radius Rb of the edgewise bending portion. Since the inner periphery of the bending is subjected to compressive deformation in the longitudinal direction at the time of edgewise bending, by forming an arc shape having a radius equal to or larger than the inner bending radius Rb in advance, it is equal to the inner bending radius Rb after the edgewise bending. Shape can be obtained.

DESCRIPTION OF SYMBOLS 11 Straight part 12 Concave part 13 Convex part 13a, 13b, 13c Individual convex part 14 Short side surface 14a Concave part 14b Convex part 15 Long side side surface 100 Bus bar

Claims (7)

An aluminum alloy material for a bus bar that has a straight portion and is edgewise bent,
A recess formed in a portion corresponding to a bending inner periphery of the edgewise bending process;
A convex portion formed on a portion corresponding to a bending outer peripheral portion of the edgewise bending process,
An aluminum alloy material for bus bars characterized by the above. The concave portion has an arc shape having a radius equal to or larger than the inner bending radius of the edgewise bending portion,
The minimum distance from the edge of the concave portion to the edge of the convex portion is a distance greater than or equal to the width of the straight portion.
The aluminum alloy material for bus bars according to claim 1. The area of the convex part is equal to or greater than the area of the concave part,
The aluminum alloy material for bus bars according to claim 1. The convex portion includes a plurality of individual convex portions.
The aluminum alloy material for bus bars according to claim 1. The arc portion circumferential length of the convex portion is longer than the arc portion circumferential length of the concave portion,
The aluminum alloy material for bus bars according to claim 1. The aluminum alloy material for bus bars according to any one of claims 1 to 5,
This is a bus bar. Prepare a bus bar material with a straight part and an edgewise bent part bent by a concave part and a convex part,
With the concave portion on the inside and the convex portion on the outside, edgewise bending is performed in the edgewise bending portion,
A method of manufacturing a bus bar.

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