JP2007124751A - Bus bar connection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a configuration, inhibit a bus bar from being deformed when the bus bar is fastened, and eliminate a fastening nut in a connection using the bus bar. <P>SOLUTION: A vehicle motor 10 is shown as one apparatus, and an inverter circuit 20 is shown as the other apparatus, respectively. The bus bar connection 30 is connected between a power line terminal 14 in a stator 12 of the motor 10 and a terminal block 22 of the inverter circuit 20. The bus bar connection 30 is fixed and connected between the power line terminal 14 and one end of the L-shape bus bar 40 by a fastening bolt 32, and fixed and connected between the terminal block 22 and the other end of the L-shape bus bar 40 by a fastening bolt 34. Female threads are provided at the terminal block 22 and the other end of the L-shape bus bar 40. A thickness of the L-shape bus bar 40 is sufficiently large so as to reduce a shearing force generated by fastening to an allowable shearing force or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bus bar connection portion, and more particularly, to a bus bar connection portion that electrically connects between one device side and the other device side using a bus bar.

  For example, a connection portion using a bus bar is used to electrically connect one device side to the other device side, such as connection for power supply between a vehicle motor and an inverter circuit. It is done. The bus bar is made of a metal plate such as a copper plate, and both ends thereof are firmly fixedly connected to one device side and the other device side by fastening means such as a combination of bolts and nuts. An example of the bus bar has a bent shape such as an L shape so that the plate thickness is about 1 mm to 2 mm, for example, and is convenient for connection between one device side and the other device side.

  Due to the fact that the dimensions between the mounting portions at both ends of the bus bar do not necessarily match exactly with respect to the positional relationship between the one and the other device side mounting portions, the one device side and the other device side When the bus bar is attached to the apparatus side by the fastening means, the bus bar may be forcibly attached or the bus bar may be deformed.

  For example, in Patent Document 1, using a terminal block, a motor stator electric wire terminal on one end side of a substantially L-shaped bus bar, an inverter cable connection terminal on the other end side, a bolt and a nut on the terminal block side, respectively. In order to tighten, the bus bar is dimensioned so that it can move freely in the vertical direction with respect to the terminal block, and the nut on the terminal block side can be moved in the vertical direction without rotating in the tightening rotation direction with respect to the terminal block. It has been. As a result, when the bus bar and the connection terminal are tightened with bolts, the nut is freely lifted together with the bus bar, and even if there is a variation in the dimensions of the terminal block, no excessive force is applied to the connection terminal or the like by tightening.

  In Patent Document 2, in order to connect and connect a plurality of bus bars on the supply side and a plurality of bus bars on the reception side, an integrated portion is provided at the tip of a bus bar group consisting of a plurality of bus bars on the supply side. A method of removing an unnecessary portion of the integrated portion after providing an integrated portion at the front end of the bus bar group on the receiving side and welding the bus bars to each other using the integrated portion is described. Thereby, the position shift at the time of welding of a corresponding bus bar is reduced.

  Patent Document 3 describes a circuit board in which a bus bar composed of a strip-shaped circuit portion formed by punching a conductive plate into a circuit shape is molded with an insulating resin. In this case, the circuit portion of the bus bar is bent by the pressure at the time of resin molding by curving the circuit portion so that the protruding portion faces the opposite portion of the resin injection port provided in the mold for molding. Prevents bending.

JP 2004-327184 A JP 2003-219545 A JP 2002-84629 A

  As described above, the connection using the bus bar is likely to be deformed at the time of fastening because the bus bar is a plate material of about 1 mm to 2 mm. In order to prevent the deformation and perform the fastening, for example, a jig with a slit is prepared, and careful work such as receiving the force at the time of fastening with the whole jig while fixing the bus bar with the slit is necessary. By using the device described in the prior art, it is possible to prevent the bus bar from being deformed or bent due to a shift in the connection position or the like, but the configuration is considerably complicated.

  Further, as a simple configuration, in order to fasten the bus bar to one device side and the other device side with screws, a set of bolts and nuts is required. To eliminate the nut, a part with a female thread known as a cell fastener can be press-fitted into the bus bar, but the work such as press-fitting increases, and the contact area with the mating counterpart decreases depending on the press-fitting condition. However, the electrical connection may be insufficient.

  An object of the present invention is to provide a bus bar connecting portion that can suppress deformation of the bus bar at the time of fastening with a simple configuration. Another object is to provide a bus bar connecting portion that can omit a nut for fastening. The following means contribute to at least one of these purposes.

  The bus bar connection unit according to the present invention is a bus bar connection unit that electrically connects one device side to the other device side using a bus bar, and one end is connected to one device side, and the other One side terminal having a hole through which the threaded portion of the fastening bolt passes, the other end connected to the other device side, and a bus bar engraved with a female screw engaged with the threaded portion of the fastening bolt at one end, and the one side terminal A fastening bolt for passing the screw part through the hole through which the screw part is passed, aligning the position of the female screw of the bus bar, engaging the screw part and the female screw, and tightening the one side terminal and the bus bar, The thickness of the one end where the female screw is engraved is characterized in that the stress determined by the tightening torque of the fastening bolt is equal to or less than the allowable stress of the bus bar material.

  Further, the bus bar is made of an aluminum material, and the thickness of one end thereof is preferably 1.5 times or more the axial thickness of a fastening nut usually used for a fastening bolt.

  Moreover, it is preferable that a bus bar has a shape which becomes an L shape between one end and the other end.

  With the above configuration, the bus bar is engraved with a female screw that engages with the threaded portion of the fastening bolt, and the portion has a thickness such that the stress determined by the tightening torque of the fastening bolt is equal to or less than the allowable stress of the bus bar material. That is, even if the fastening bolt is directly engaged with the female screw of the bus bar and fastened, it has sufficient strength. Therefore, it is providing the bus-bar connection part which can suppress a deformation | transformation of the bus-bar at the time of fastening. Another object is to suppress the bus bar from being deformed and broken even when the fastening bolt is tightened. Moreover, the nut for fastening can be omitted.

  The bus bar is made of an aluminum material, and the thickness of one end of the bus bar is 1.5 times or more the axial thickness of a fastening nut usually used for fastening bolts. The thickness can be made sufficient in consideration of the above.

  Moreover, since the bus bar has a shape that is L-shaped between one end and the other end, it can be formed into a shape that is convenient for connection between one device side and the other device side.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a motor for a vehicle and an inverter circuit will be described as one and the other device to which the bus bar connection unit is applied. However, any other device can be electrically connected using a bus bar. Good. In addition, the bus bar is described as being provided between one terminal on one device side and a terminal plate on the other device side, but for connection between one device side and the other device side. As long as a bus bar is used, other connection forms, for example, a connection between connection portions of two devices, a connection between two terminals, a connection between two connection plates, or the like may be used. The materials, shapes, and dimensions described below are examples, and shapes and dimensions adapted to specific connection forms can be employed. For example, depending on the arrangement of the devices to be connected, a bus bar having a shape other than the L-shape can be used, and the thickness of the bus bar can be changed depending on the size of the fastening bolt. In addition, a material other than aluminum, for example, copper or another alloy can be used as long as the material has sufficient conductivity.

  FIG. 1 is a diagram illustrating a state of a bus bar connection unit that electrically connects two devices using a bus bar. Here, a motor 10 for a vehicle is shown as one device, and an inverter circuit 20 is shown as the other device. A bus bar is provided between the power line terminal 14 in the stator 12 of the motor 10 and the terminal block 22 of the inverter circuit 20. It is connected by the connection unit 30.

  The bus bar connection part 30 is fixedly connected between the power line terminal 14 and one end of the L-shaped bus bar 40 with a fastening bolt 32, and is also fastened between the terminal block 22 and the other end of the L-shaped bus bar 40. The bolt 34 is fixedly connected. Here, female screws are engraved on the terminal block 22, and female screws are also engraved on one end of the L-shaped bus bar 40, so that fastening can be performed with the fastening bolts 32 and 34 without using nuts. .

  FIG. 2 is a detailed view of the L-shaped bus bar 40. The L-shaped bus bar 40 is formed by bending an aluminum material having a thickness A = B into an L-shape, and engraving a female screw 42 that meshes with a screw portion of the fastening bolt 32 at one end, and a shaft portion of the fastening bolt 34 at the other end. It has a structure in which a through hole 46 is provided. Here, at the portion of the female screw 42 at one end of the L-shaped bus bar 40, the portion of the surface where the power line terminal 14 faces is a flat surface portion 44.

  The dimension of the L-shaped bus bar 40 can be set according to the size of the fastening bolts 32 and 34. For example, the thread portion of the fastening bolt is a 6 mm metric screw, the female screw 42 is a 6 mm metric screw, the through hole 46 has a diameter of about 6.5 mm, and the thickness of the L-shaped bus bar 40 is A = B = 9 mm. It is. The width can be about 13 mm. The diameter of the surface dashi portion 44 can be about 13 mm, which is the same as the width of the L-shaped bus bar 40. As for the L-shaped dimension, the length on one end side where the female screw 42 is provided can be about 20 mm, and the length on the other end where the through hole 46 is provided can be about 32 mm.

  The thickness A of one end where the female screw 42 is engraved in the L-shaped bus bar 40 is set to withstand the fastening torque by the fastening bolt 32. That is, when a power line terminal is sandwiched between the head of the fastening bolt 32 and one end of the L-shaped bus bar 40 and the screw portion of the fastening bolt 32 and the female screw 42 of the L-shaped bus bar 40 are engaged and fastened. Further, the stress generated in the internal thread 42 of the L-shaped bus bar 40 is determined to be equal to or less than the allowable stress of the material of the L-shaped bus bar 40.

  When the material of the L-shaped bus bar 40 is aluminum or an aluminum alloy, the threaded portion of the fastening bolt 32 is a 6 mm metric screw, and the fastening torque is about 12 N · m, a thickness A of about 9 mm is sufficient. The axial thickness of the nut combined with the metric screw fastening bolt 32 having a threaded portion of 6 mm is usually about 6 mm. Compared to the length of the threaded portion of this normal nut, the internal thread of the L-shaped bus bar 40 The axial length of 42 is 9 mm / 6 mm = 1.5 times longer. This thickness is much thicker than the conventional bus bar thickness of 1 mm to 2 mm, such as a copper plate material, so that a female screw that can sufficiently support the fastening torque can be carved into the L-shaped bus bar. .

  In the L-shaped bus bar 40, the thickness B at the other end where the through hole 46 is provided is set to withstand the fastening torque by the fastening bolt 32. That is, when the power line terminal 14 is sandwiched between the head of the fastening bolt 32 and the L-shaped bus bar 40 and the screw portion of the fastening bolt 32 and the female screw 42 of the L-shaped bus bar 40 are engaged and fastened, The stress generated in the portion of the base C where the L-shaped bus bar 40 bends in an L shape is determined to be equal to or less than the allowable stress of the material of the L-shaped bus bar 40. In this case as well, as in the case of the thickness A, if the material of the L-shaped bus bar 40 is aluminum or an aluminum alloy, the screw portion of the fastening bolt 34 is a 6 mm metric screw, and the fastening torque is about 12 N · m, the thickness About 9 mm is sufficient for B.

  Further, the width of the surface dashi portion 44 provided at one end of the L-shaped bus bar 40 can be made sufficiently wide according to the area of the connecting portion of the power line terminal 14 facing the L-shaped bus bar 40. Although the connection part of the power line terminal 14 is not illustrated, it is configured as a lug terminal shape having a hole through which the screw part of the fastening bolt 32 passes. The width of the surface dashi portion 44 can be set as having a diameter larger than the outer diameter of the lug terminal.

  The operation of the bus bar connecting portion 30 having such a structure will be described. When the motor 10 and the inverter circuit 20 are mounted in a predetermined arrangement in the vehicle, the plurality of power line terminals 14 of the stator 12 of the motor 10 and the corresponding connecting portions of the terminal block 22 of the inverter circuit 20 are connected. Are connected by an L-shaped bus bar 40. As described above, the L-shaped bus bar 40 has one end provided with a female screw 42 that meshes with the screw portion of the fastening bolt 32 and the other end provided with a through hole 46 through which the screw portion of the fastening bolt 34 passes.

  The through hole 46 at the other end of the L-shaped bus bar 40 is aligned with the position of the female screw provided at the corresponding connection portion of the terminal block 22, and the screw portion of the fastening bolt 34 is passed through the through hole 46. The other end of the L-shaped bus bar 40 is sandwiched between the head and the terminal block 22. Then, the fastening bolt 34 is fastened with a fastening torque of about 12 N · m. Since the thickness B of the other end of the L-shaped bus bar 40 is about 9 mm, the stress generated at the root C portion of the L-shaped bus bar 40 made of aluminum or aluminum alloy that is bent to the L shape is allowed. Since it is below the stress, the L-shaped bus bar 40 is sufficiently fastened to the power line terminal 14 without being deformed.

  Further, the other end of the power line terminal 14 whose one end is connected to the stator 12 is extended so as to be aligned with the position of the female screw 42 at one end of the L-shaped bus bar 40. More specifically, the lug terminal-shaped portion at the other end of the power line terminal 14 is aligned with the surface dashi portion 44 at one end of the L-shaped bus bar 40, and the position of the lug terminal-shaped through hole is the L-shaped bus bar. 40 is aligned with a female screw 42 at one end of 40. By setting the size of the through holes to be large to some extent, it is possible to increase the allowable range of these alignments. Thereby, the dislocation between the terminal block 22 and the stator 12 can be absorbed to some extent. It is preferable that the area of the surface dangling portion 44 is wide so as to include a range in which the position of the lug terminal is shifted by the alignment. When the through hole of the power line terminal 14 and the female screw 42 of the L-shaped bus bar 40 are aligned, the other end of the power line terminal 14 is sandwiched between the head of the fastening bolt 32 and the L-shaped bus bar 40. . Then, the fastening bolt 32 is fastened with a fastening torque of about 12 N · m. Since the thickness A at one end of the L-shaped bus bar 40 is about 9 mm, the shear stress generated in the female screw 42 of the L-shaped bus bar 40 made of aluminum or aluminum alloy is less than the allowable shear stress. The L-shaped bus bar 40 is sufficiently fastened to the power line terminal 14 without being deformed.

  In this way, by using the L-shaped bus bar 40 having a thickness in which the shearing force generated by the fastening torque is equal to or less than the allowable shearing stress of the material while securing a sufficient contact area by the surface dashes portion 44, the nut is removed. The bus bar connecting portion 30 can be omitted to prevent deformation due to fastening.

It is a figure which shows the mode of the bus-bar connection part in embodiment which concerns on this invention. It is detail drawing of the L-shaped bus bar in embodiment which concerns on this invention.

Explanation of symbols

  10 Motor, 12 Stator, 14 Power line terminal, 20 Inverter circuit, 22 Terminal block, 30 Bus bar connection part, 32, 34 Fastening bolt, 40 Bus bar, 42 Female thread, 44 Face part, 46 Through hole.

Claims (3)

A bus bar connection part that electrically connects between one device side and the other device side using a bus bar,
One terminal having one end connected to one device side and a hole through which the threaded portion of the fastening bolt is passed to the other end;
A bus bar in which the other end is connected to the other device side and a female screw that is engaged with the screw portion of the fastening bolt is engraved on one end;
A fastening bolt that tightens the one side terminal and the bus bar by passing the screw part through the hole through the screw part at the other end of the one side terminal, aligning the position with the female screw of the bus bar, engaging the screw part and the female screw,
With
A bus bar connecting portion characterized in that the thickness of one end where the female screw of the bus bar is engraved is such that the stress determined by the tightening torque of the fastening bolt is equal to or less than the allowable stress of the material of the bus bar. In the bus bar connection part according to claim 1,
The bus bar is made of an aluminum material, and the thickness of one end of the bus bar is 1.5 times or more the axial thickness of a fastening nut usually used for a fastening bolt. In the bus bar connection part according to claim 1,
The bus bar connecting portion, wherein the bus bar has an L-shape between one end and the other end.

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