Bus bar

Abstract

The busbar is designed to be resistant to vibration and absorb positional errors. [Solution] The inflexible first busbar 10 has a right end 12b from which a portion of the first busbar 10 has been cut off. The flexible second busbar 20 has a left end 20b from which a portion of the second busbar 20 has been cut off. As a result, the first busbar 10 and the second busbar 20 can be joined by joining the right end 12b and the left end 20b.

Description

[Technical Field]

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

[0002] A three-phase AC motor used in an in-vehicle motor module receives power supply from an inverter, and the windings of the three-phase AC motor are fastened to an electric wire or a bus bar to connect to the inverter. A current sensor is used to detect an undercurrent 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, when assembling a motor, a mechanism is required to absorb positional errors, which are errors within tolerances related to the dimensions, perpendicularity, and mounting position of each component of the motor.

[0004] Therefore, it is known to absorb positional errors by making the motor windings longer and connecting them in a bent state.

[0005] However, since the flexibility of the motor windings themselves is low, the degree of freedom in wiring 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 positional errors by means of the motor windings. If absorption of positional error is insufficient, connecting the motor to the terminal block in this state will apply stress to the motor windings, which may cause problems such as insulation breakdown.

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

[0007] [Patent Document 1] Japanese Patent Publication No. 2014-17900 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the above technologies presented problems in terms of quality control, ease of assembly, and cost, due to the large size of the busbars used as current sensors.

[0009] 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 of the motor components they are fastened 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. [Means for solving the problem]

[0012] The object of the present invention described above is achieved by the following means. The reference numerals in parentheses indicate 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 It has a flexible second busbar (20), The first busbar (10) is provided with a first cut portion (right end 12b, right end 12bA~12bE) where a part of the first busbar (10) is cut off, The second busbar (20) is provided with a second cut portion (left end 20b) in which a part of the second busbar (20) is cut off. The first busbar (10) and the second busbar (20) are joined by joining the first cut portion (right end 12b, right end 12bA~12bE) and the second cut portion (left end 20b).

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

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

[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, due to its inflexibility.

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

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

[0020] According to the invention of claim 3, size reduction of the device itself to which the bus bar (1) is attached can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] [Figure 1] FIG. 1 is a perspective view illustrating a bus bar according to an embodiment of the present invention, explaining an example in which the bus bar is used as a bus bar for a three-phase current sensor. [Figure 2] (a) is a rear view of the bus bar according to the embodiment, and (b) is a side view of the bus bar according to the embodiment. [Figure 3] FIG. 3 is an enlarged side view showing a right end portion of a horizontal portion of a partially cut-out first bus bar and a right end portion of a partially cut-out second bus bar, wherein (a) shows a state where the bus bars are about to be joined, and (b) shows a state where the bus bars are joined. [Figure 4] FIGS. 4(a) to 4(c) are perspective views showing a state where the right end of the horizontal portion of the partially cut-out first bus bar is inclined. [Figure 5] FIG. 5, (a) shows a state where the right end of the horizontal portion of the partially cut-out first bus bar is expanded, and (b) shows a state where the right end of the horizontal portion of the partially cut-out first bus bar is contracted. DESCRIPTION OF EMBODIMENTS

[0022] Hereinafter, a bus bar according to an embodiment of the present invention will be specifically described with reference to the drawings. In the following description, when up, down, left, and right directions are indicated, they refer to up, down, left, and right as viewed from the front of the drawings.

[0023] 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. A detailed explanation follows.

[0025] <Explanation of the first bus bar> 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 surface 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, a portion of the right end surface 12b of the horizontal section 12 is cut out, as shown in Figure 2(b).

[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] <Explanation of the second bus bar> The second busbar 20 is formed as a flexible busbar by laminating conductive material foil 21 made of a thin, flexible metal such as copper or 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, a portion of the left end 20b of the second busbar 20 is cut out, as shown in Figure 2(b).

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

[0033] <Explanation of the connection between the first and second busbars> Thus, the connection between the first busbar 10 and the second busbar 20, configured as described above, is carried out 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, the first busbar 10 and the second busbar 20 can be joined by welding (including resistance welding) or brazing in the state shown in Figure 3(b).

[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, 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, as shown in Figure 3(a). Furthermore, 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 variations> It should be noted that 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. 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. 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, making it narrower.

[0041] Therefore, it is 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 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. [Explanation of Symbols]

[0044] 1 Bus bar 10 First Bus Bar 11 Vertical part (one end) 12b,12bA~12bE Right end (1st cutting part) 20 Second Bus Bar 20b Left end (2nd cutting part) H1~H4 Plate Thickness

Claims

1. The first busbar is inflexible, It has a flexible second busbar, The first busbar is provided with a first cut portion in which a part of the first busbar is cut off, The second busbar is provided with a second cut portion in which a part of the second busbar is cut off. The first busbar and the second busbar are joined together by joining the first cut portion and the second cut portion.

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

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

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