Bus bar

Abstract

The present invention provides a bus bar that is resistant to vibration and that is capable of absorbing a positional error. A non-flexible first bus bar 10 includes a right end portion 12b in which a part of the first bus bar 10 is cut. A flexible second bus bar 20 includes a left end portion 12b in which a part of the second bus bar 20 is cut. Thus, the first bus bar 10 and the second bus bar 20 can be joined by joining the right end portion 12b and the left end portion 20b.

Description

Bus bar

[0009] ,

[0001] The present invention relates to a bus bar.

[0002] The three-phase AC motor used in an in-vehicle motor module receives power supply from an inverter. Since the windings of the three-phase AC motor are connected to the inverter, they are fastened to electric wires or bus bars. In addition, a current sensor is used to detect insufficient current flowing through the windings of the three-phase AC motor. This current sensor has a sensor module mounted on the bus bar.

[0003] By the way, during the motor assembly work, a mechanism is required to absorb the positional error, which is an error within the tolerance regarding the dimensions, perpendicularity, and mounting position of each part of the motor.

[0004] Therefore, it is known that the positional error is absorbed by making the motor winding longer and connecting it in a deflected state.

[0005] However, since the flexibility of the motor winding itself is small, the wiring freedom is low. Therefore, when the motor is mounted in a narrow space, the distance between the stator of the motor and the terminal block becomes short, making it difficult to absorb the positional error by the motor winding. If the absorption of the positional error is insufficient and the motor is connected to the terminal block in this state, stress may be applied to the motor winding, resulting in problems such as insulation breakdown.

[0006] Therefore, in order to solve such problems, a technique as described in Patent Document 1 has been proposed. The invention described in this Patent Document 1 relates to an inverter in which the terminal block is supported in a cantilever manner and connected to an external cable at the opposite end, and aims to reduce the stress applied to the support end of the terminal block.

[0007] Japanese Patent Application Laid-Open No. 2014-17900

[0008] However, the above-mentioned technique has problems in terms of quality control, assembly, and cost because the size of the bus bar used as the current sensor becomes large. [[ID=Therefore, in order to solve the above problems, it is conceivable to use a flexible busbar as the busbar used as a current sensor.

[0010] However, while flexible busbars offer flexibility, they have a problem in that they have low resistance to vibration in the individual motor components they fasten to.

[0011] Therefore, in view of the above problems, the present invention aims to provide a busbar that is resistant to vibration and can absorb positional errors.

[0012] The object of the present invention described above is achieved by the following means. The reference numerals in parentheses indicate the embodiments described later, but the present invention is not limited thereto.

[0013] The busbar according to claim 1 comprises a non-flexible first busbar (10) and a flexible second busbar (20), wherein the first busbar (10) has a first cut portion (right end 12b, right end 12bA to 12bE) in which a part of the first busbar (10) is cut off, and the second busbar (20) has a second cut portion (left end 20b) in which a part of the second busbar (20) is cut off, and the first busbar (10) and the second busbar (20) are joined by joining the first cut portion (right end 12b, right end 12bA to 12bE) and the second cut portion (left end 20b).

[0014] The busbar according to claim 2 is characterized in that, in the busbar (1) described in claim 1, the plate thickness (H1) of the first busbar (10) and the plate thickness (H2) of the second busbar are formed to be the same, and when the first busbar (10) and the second busbar (20) are joined, the first cut portion (right end 12b, right end 12bA to 12bE) is formed to have a step, and the second cut portion (left end 20b) is also formed to have a step, so that the plate thickness (plate thickness H3 + plate thickness H4) of the joined portion is the same as the plate thickness (H1) of the first busbar (10) and the plate thickness (H2) of the second busbar (20).

[0015] The busbar according to claim 3 is characterized in that, in the busbar (1) described in claim 1 or 2, one end (vertical portion 11) of the first busbar (10) is formed to serve as a terminal block.

[0016] Next, the effects of the present invention will be described with reference to the reference numerals in the drawings. Note that the reference numerals in parentheses are those of embodiments described later, but the present invention is not limited thereto.

[0017] According to the invention of claim 1, by joining the first cut portion (right end portion 12b, right end portions 12bA to 12bE) and the second cut portion (left end portion 20b), the inflexible first busbar (10) and the flexible second busbar (20) can be joined. As a result, the flexible second busbar (20) can absorb the positional errors described above because it is flexible. Furthermore, the inflexible first busbar (10) has the characteristic of being highly resistant to vibration of each component of the motor to which it is fastened because it is inflexible.

[0018] Therefore, according to the present invention, it is possible to provide a busbar (1) that is resistant to vibration and can absorb positional errors.

[0019] According to the invention of claim 2, when the busbar (1) is fastened to each component of the motor, interference with the surrounding area can be eliminated.

[0020] According to the invention of claim 3, the device to which the busbar (1) is attached can be made smaller.

[0021] This is a perspective view showing a busbar according to one embodiment of the present invention and illustrating an example of its use as a busbar for a three-phase current sensor. (a) is a rear view of the busbar according to the present embodiment, and (b) is a side view of the busbar according to the present embodiment. This shows an enlarged side view of the right end portion of the horizontal part of a first busbar with a portion cut out and the right end portion of a second busbar with a portion cut out, with (a) showing the state in which they are about to be joined and (b) showing the joined state. (a) to (c) are perspective views showing the right end portion of the horizontal part of a first busbar with a portion cut out in an inclined state. (a) shows an enlarged view of the right end portion of the horizontal part of a first busbar with a portion cut out, and (b) shows a reduced view of the right end portion of the horizontal part of a first busbar with a portion cut out.

[0022] A busbar according to one embodiment of the present invention will be described in detail below with reference to the drawings. In the following description, when the directions of up, down, left, and right are indicated, they refer to the up, down, left, and right directions as viewed from the front as shown in the drawings.

[0023] <Overview of the Busbar> The busbar according to this embodiment is primarily used as a busbar for a three-phase current sensor, and is resistant to vibration and can absorb positional errors. Specifically, as shown in Figure 1, the busbar 1 according to this embodiment is shown as an example of being used as a busbar for a three-phase current sensor, and therefore three busbars are arranged in parallel with intervals between them. Since the busbar 1 is used as a current sensor, a sensor module (not shown) is mounted on it.

[0024] By the way, as shown in Figures 1 and 2, the busbar 1 described above is formed by joining a first busbar 10 and a second busbar 20. This will be explained in more detail below.

[0025] <Description of the First Busbar> The first busbar 10 is formed in an L-shape as shown in Figures 1 and 2(b), and is inflexible. It is made of materials such as copper or aluminum.

[0026] Thus, the first busbar 10 formed in this manner has a vertical portion 11 and a horizontal portion 12 integrally provided, as shown in Figures 1 and 2(b). The vertical portion 11 is formed in a convex shape, as shown in Figure 1, and in an upright shape, as shown in Figures 1 and 2(b). This vertical portion 11 plays a role in fixing to a mating housing (for example, various parts of a motor) or mating terminals, in other words, it functions as a terminal block. For this reason, it is formed in an upright shape and has a flat surface, as shown in Figure 2(b). This allows for the use of crimp nuts, through-holes, or soldering when fixing to a mating housing (for example, various parts of a motor) or mating terminals (in Figure 1, a crimp nut N is shown as an example with a dashed line). By providing the busbar 1 with a vertical portion 11 that functions as a terminal block, the equipment to which the busbar 1 is attached can be miniaturized. This vertical portion 11 is covered with a resin member IS, as shown in Figure 1. In other words, the vertical portions 11 of each of the three busbars 1 are covered with a resin member IS and integrally molded. This resin member IS serves as an insulator. That is, since the busbars 1 according to this embodiment are used as busbars for a three-phase current sensor, the currents flowing through each of the three busbars 1 are different. Therefore, to prevent the current from one busbar 1 from flowing into the other busbars, they are covered with a resin member IS as shown in Figure 1 for insulation. Needless to say, this resin member IS does not cover the parts that are fastened to the mating housing (for example, the various components of a motor) or mating terminals.

[0027] Furthermore, as shown in Figure 2(b), the horizontal section 12 is formed in a horizontally elongated rectangular shape when viewed from the side, and the lower end surface 11a of the vertical section 11 and the left end surface 12a of the horizontal section 12 are integrally connected. As shown in Figure 2(b), a portion of the right end 12b of the horizontal section 12 is cut out. More specifically, as shown in Figure 3(a), a rectangular portion 12ba, indicated by a dashed line, is cut out from the lower surface 12c to the upper surface 12d of the horizontal section 12 so as to form a step. As a result, as shown in Figure 2(b), a portion of the right end 12b of the horizontal section 12 is cut out.

[0028] On the other hand, as shown in Figure 2(b), a notch 12e is provided in the center of the horizontal section 12. As shown in Figure 2(a), the notch 12e is formed in a narrow shape with the width of the upper surface 12f and lower surface 12g of the horizontal section 12 narrowed. By forming this notch 12e, the current density that flows is increased, so that the magnetic field can be accurately detected by a sensor module (not shown).

[0029] The above is a description of the first bus bar 10.

[0030] <Description of the second busbar> The second busbar 20 is formed as a flexible busbar by laminating conductive material foils 21 made of thin, flexible metals such as copper and aluminum. This makes it possible to bend it into a stepped shape as shown in Figures 1 and 2(b). In this embodiment, a stepped shape is used as an example, but of course, it can be bent into any shape, not just a stepped shape.

[0031] Incidentally, as shown in Figures 1 and 2, a long, elliptical bolt hole 20a1 is provided through the right end 20a of the second busbar 20 in the vertical direction. Furthermore, as shown in Figure 2(b), a portion of the left end 20b of the second busbar 20 is cut out. To explain in more detail, as shown in Figure 3(a), a rectangular portion 20ba, indicated by a dashed line, is cut out from the upper surface 20c to the lower surface 20d of the second busbar 20 so as to form a step. As a result, as shown in Figure 2(b), a portion of the left end 20b of the second busbar 20 is cut out.

[0032] The above is a description of the second bus bar 20.

[0033] <Explanation of joining the first busbar and the second busbar> Thus, the first busbar 10 and the second busbar 20, which are configured as described above, are joined as follows.

[0034] Specifically, as shown in Figure 3(a), the left end portion 20b of the second busbar 20, which is partially cut out, is inserted into the portion where a part of the right end portion 12b of the horizontal portion 12 of the first busbar 10 is cut out (see the rectangular portion 12ba shown by the dashed line). Furthermore, as shown in Figure 3(b), the right end portion 12b of the horizontal portion 12 of the first busbar 10, which is partially cut out, is inserted into the portion where a part of the left end portion 20b of the second busbar 20 is cut out (see the rectangular portion 20ba shown by the dashed line). Thus, in the state shown in Figure 3(b), the first busbar 10 and the second busbar 20 can be joined by joining them using welding (including resistance welding) or brazing.

[0035] Therefore, by joining the inflexible first busbar 10 and the flexible second busbar 20 in this manner, the flexible second busbar 20 can absorb the positional errors described above because of its flexibility. Furthermore, the inflexible first busbar 10 has the advantage of being highly resistant to vibrations of the motor components it fastens to.

[0036] Therefore, according to the embodiment described above, it is possible to provide a busbar 1 that is resistant to vibration and can absorb positional errors.

[0037] By the way, the plate thickness of the first busbar 10 and the plate thickness of the second busbar 20 described in this embodiment are the same. To explain in more detail, as shown in Figure 3(a), the plate thickness H1 of the horizontal portion 12 of the first busbar 10 and the plate thickness H2 of the second busbar 20 are the same. Furthermore, as shown in Figure 3(a), when the plate thickness H3 of the right end 12b of the horizontal portion 12 of the first busbar 10 and the plate thickness H4 of the left end 20b of the second busbar 20 are added together, the plate thickness H1 of the horizontal portion 12 of the first busbar 10 and the plate thickness H2 of the second busbar 20 are made to be the same. In other words, plate thickness H1 = plate thickness H2 = plate thickness H3 + plate thickness H4. In this way, when the busbar 1 is fastened to each component of the motor, interference with the surroundings can be eliminated. Note that if interference with the surroundings is not a concern, it is not necessary to match the plate thickness as described above.

[0038] <Explanation of Modifications> The shapes shown in this embodiment are merely examples, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. For example, in this embodiment, as shown in Figure 3(a), a rectangular portion 12ba, indicated by a dashed line, is cut out from the lower surface 12c of the horizontal portion 12 toward the upper surface 12d. However, the invention is not limited to this, and the cutout may be made from the upper surface 12d toward the lower surface 12c of the horizontal portion 12. In this case, a part of the left end portion 20b of the second busbar 20 may be cut out from the lower surface 20d toward the upper surface 20c.

[0039] Furthermore, in this embodiment, as shown in Figure 3(a), a rectangular shape is exemplified as the cut-out portion 12ba of the right end 12b of the horizontal portion 12 of the first busbar 10, and a rectangular shape is exemplified as the cut-out portion 20ba of the left end 20b of the second busbar 20. However, the shape itself can be any shape. Hereinafter, specific examples will be given using the horizontal portion 12 of the first busbar 10.

[0040] For example, as shown in Figure 4(a), the right end portion 12bA of the horizontal portion 12 may be partially cut out so that it slopes upward from the front end surface to the rear end surface shown. Also, as shown in Figure 4(b), the right end portion 12bB of the horizontal portion 12 may be partially cut out so that it slopes upward from the left end surface to the right end surface shown. Furthermore, as shown in Figure 4(c), the right end portion 12bC of the horizontal portion 12 may be partially cut out so that it slopes downward from the front end surface to the rear end surface shown, making it narrower.

[0041] Therefore, it is also possible to tilt it as described above. In this case, if the plate thickness is to be matched as described above, a portion of the left end 20b of the second busbar 20 should be shaped to match the shape of the right end 12bA, right end 12bB, and right end 12bC of the horizontal section 12 as described above. Alternatively, if it is not necessary to match the plate thickness, for example, a portion of the left end 20b of the second busbar 20 may be left in the rectangular shape described above and joined together. In this case, there is the advantage that the joint portion can be tilted.

[0042] On the other hand, instead of tilting as described above, a portion of the horizontal section 12 may be cut out so that the right end portion 12bD of the horizontal section 12 expands from the left end face to the right end face as shown in Figure 5(a). Furthermore, a portion of the horizontal section 12 may be cut out so that the right end portion 12bE of the horizontal section 12 shrinks from the left end face to the right end face as shown in Figure 5(b).

[0043] Therefore, as explained using specific examples, the shape itself can be any shape.

[0044] 1 Busbar 10 First busbar 11 Vertical section (one end) 12b, 12bA to 12bE Right end (first cut section) 20 Second busbar 20b Left end (second cut section) H1 to H4 Plate thickness

Claims

1. A busbar comprising a non-flexible first busbar and a flexible second busbar, wherein the first busbar has a first cut portion in which a part of the first busbar is cut off, and the second busbar has a second cut portion in which a part of the second busbar is cut off, and the first busbar and the second busbar are joined by joining the first cut portion and the second cut portion.

2. The busbar according to claim 1, wherein the thickness of the first busbar and the second busbar are formed to be the same, and when the first busbar and the second busbar are joined, the first cut portion is formed to have a step, and the second cut portion is also formed to have a step, so that the thickness of the joined portion is the same as the thickness of the first busbar and the second busbar.

3. The bus bar according to claim 1 or 2, wherein one end of the first bus bar is formed to function as a terminal block.

Images