JP2016035946A - Bus bar joining structure and bus bar joining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase of the size of equipment even when bus bars large in cross section and mass are subjected to ultrasonic joining.SOLUTION: A bus bar 1 on a motor side and a bus bar 3 on an inverter side are overlapped to each other to be subjected to ultrasonic joining. In the bus bar 1 on a motor side, a plurality of split pieces 1c are formed along a width direction thereof by forming a plurality of slits 1b along a longitudinal direction thereof. A vibrator 7 is individually pressed against each of the plurality of split pieces 1c to ultrasonically join the bus bars 1, 3 to each other.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a bus bar bonding structure and a bus bar bonding method for ultrasonic bonding in a state where a pair of plate-like bus bars are superposed on each other.

  Patent Document 1 below discloses a technique for ultrasonically bonding a lead of a terminal portion to a wiring pattern on a substrate.

JP 2013-51366 A

  By the way, the high-power bus bar used for electrically connecting the motor and the inverter has a large cross-sectional area and a large mass. For this reason, when high-power busbars are ultrasonically bonded together, it is necessary to use a larger ultrasonic bonder with higher output or a stronger restraining jig, which increases the size of the equipment. Invite.

  Then, even if it is a case where it joins ultrasonically with respect to a bus bar with a large cross-sectional area and mass, this invention aims at suppressing the enlargement of an installation.

  The present invention is characterized in that at least one of the pair of plate-like bus bars that are ultrasonically bonded to each other in a state of being superposed on each other includes a divided part that is divided into a plurality of parts.

  According to the present invention, ultrasonic bonding is performed for each of a plurality of divided portions provided on the bus bar, so that even a bus bar having a large cross-sectional area or mass can be bonded with weaker vibrations, thereby suppressing an increase in size of the facility. Can do.

It is a perspective view showing a pair of bus bars by a 1st embodiment to which a bus bar joining method of the present invention is applied. It is a top view of the bus bar of FIG. FIG. 2 is an operation explanatory diagram illustrating a state in which ultrasonic bonding is performed on the bus bar of FIG. 1 using a vibrator. It is a perspective view which shows a pair of bus bar by the 2nd Embodiment of this invention. It is a perspective view which shows a pair of bus bar by the 3rd Embodiment of this invention. It is a perspective view which shows a pair of bus bar by the 4th Embodiment of this invention. It is a perspective view which shows a pair of bus bar by the 5th Embodiment of this invention. It is a perspective view which shows a pair of bus bar by the 6th Embodiment of this invention. It is effect | action explanatory drawing which shows the 7th Embodiment of this invention.

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

  FIG. 1 shows a pair of bus bars 1 and 3 according to a first embodiment to which a bus bar joining structure and a bus bar joining method of the present invention are applied. The pair of bus bars 1, 3 here electrically connect the motor and the inverter, which are electrical devices, by ultrasonically joining the bus bar 1 on the motor side and the bus bar 3 on the inverter side, which are employed in an electric vehicle, for example. Connecting. Note that the motor and the inverter here have an electromechanical integrated structure integrated with each other, and are accommodated in the same housing.

  As shown in FIG. 2, one bus bar 1 has four slits 1b extending in the longitudinal direction (left-right direction in FIG. 2) at an end 1a on the distal end side. The slit 1b has an opening at the distal end, and extends from the opened end toward the proximal end. The intervals between the four slits 1b are equal to each other. Further, by forming the four slits 1b, five divided pieces 1c extending along the longitudinal direction of the bus bar 1 are formed. The widths of the five divided pieces 1c corresponding to the vertical direction in FIG. 2 are equal to each other, and the width of the divided pieces 1c is larger than the width of the slit 1b.

  That is, the bus bar 1 includes a divided piece 1c that is a divided portion that is divided into a plurality of portions along the width direction corresponding to the vertical direction in FIG. As shown in FIG. 2, the other bus bar 3 is simply formed in a plate shape and does not have a slit like the bus bar 1. The width dimensions of the bus bars 1 and 3 are equal to each other.

  The end portions 1a and 3a of the bus bars 1 and 3 are overlapped with each other as shown in FIG. That is, at least one of the pair of plate-like bus bars 1 and 3 connected to each other by bonding is provided with a divided part that is divided into a plurality of parts. In FIG. 1, the end 1 a of the bus bar 1 is overlaid on the end 3 a of the bus bar 3.

  Then, as shown in FIG. 3, ultrasonic bonding is performed with the bus bar 3 placed on the base 5. At that time, the tips of the vibrator 7 as a tool of the ultrasonic bonding machine are individually pressed sequentially along the width direction from the outermost divided piece 1c, and are individually ultrasonically vibrated, whereby the bus bars 1, 3 The end portions 1a and 3a are ultrasonically joined to each other. As shown in FIG. 3, the shape of the portion of the tip (lower end) of the vibrator 7 that contacts the split piece 1 c has a width in the left-right direction substantially equal to the width of the split piece 1 c, and the length in the depth direction in FIG. 3. Is almost the same as the width, and is almost square as a whole. The contact position of the vibrator 7 with respect to the divided piece 1c is approximately the center in the longitudinal direction of the divided piece 1c.

  In this case, the ultrasonic vibration is applied by the vibrator 7 to one divided piece 1 c provided at the end 1 a of the bus bar 1. One divided piece 1c has an extremely small width corresponding to the vertical direction in FIG. 2 as compared with the entire end 1a, and therefore has a small cross-sectional area and mass. For this reason, the vibrator 7 and the ultrasonic bonding machine including the vibrator 7 may be a small one having a smaller output as compared with the case where ultrasonic bonding is performed by applying vibration to the entire end portion 1a. This equipment is unnecessary. That is, ultrasonic bonding can be performed with weaker and smaller vibrations, and an increase in the size of the facility can be suppressed.

  Since the vibration applied to the split piece 1c of the vibrator 7 can be further weakened, ultrasonic bonding can be achieved even when the bus bar 3 is not fixed to the base 5 with a jig or the like, and the equipment can be simplified. . Moreover, since weaker vibration is sufficient, damage to electronic components such as a power module in the inverter can be suppressed. Further, since the pressing force of the vibrator 7 against the bus bar can be reduced, damage to peripheral parts can be suppressed.

  Here, since the motor and the inverter mounted on the vehicle are particularly required to be miniaturized and may have an electromechanical integrated structure as described above, the vibrator when ultrasonically joining the bus bars 1 and 3 to each other. It is difficult to secure space for using tools such as 7. For this reason, it is extremely effective from the viewpoint of workability that the small vibrator 7 can be used and that no fixed jig is required as in the present embodiment.

  Moreover, the slit 1b of the edge part 1a of the bus bar 1 can be manufactured by press-molding without adding a process in the press manufacturing process of the existing bus bar which does not provide the slit 1b. In order to enable press molding, the shape of the slit 1b may be changed as appropriate.

  In the present embodiment, the divided piece 1c of the bus bar 1 is formed by a slit 1b provided in a portion where the bus bars 1 and 3 are overlapped with each other. For this reason, even if it is a bus bar with a large cross-sectional area and mass by the simple method of forming the slit 1b in the edge part 1a of the existing bus bar 1, it can ultrasonically join, without using a large sized installation. .

  In that case, the slit 1b is extended toward the base end side from the front-end | tip part of the bus-bar 1. As shown in FIG. Thereby, the division | segmentation piece 1c can be formed in multiple numbers along the width direction of the bus-bar 1, and the some division | segmentation piece 1c can be ultrasonically joined sequentially along this width direction.

  Moreover, the above-mentioned slit 1b has the front-end | tip part of the bus bar 1 opened. As a result, the divided pieces 1c that are divided are more likely to vibrate when ultrasonically vibrated, and the joining work is facilitated.

  FIG. 4 shows a second embodiment of the present invention. In the second embodiment, a bus bar 1A is used instead of the bus bar 1 in the first embodiment shown in FIGS. The bus bar 1A has a triangular shape in a plan view in which the segment 1Ac provided at the end 1Aa is narrower toward the tip. Accordingly, the slit 1Ab here has a triangular shape whose width increases toward the tip, as opposed to the divided piece 1Ac, in plan view. The bus bar 3 is the same as that of the first embodiment.

  Also in the second embodiment, by using the vibrator 7 as shown in FIG. 3 and performing ultrasonic bonding for each divided piece 1Ac, it is possible to bond with weaker and smaller vibrations as in the first embodiment. Even a bus bar having a large cross-sectional area and mass can be ultrasonically bonded without using a large facility. Moreover, in 2nd Embodiment, it can be said that the division | segmentation piece 1Ac is hard to peel from the other party bus bar 3 by joining the front-end | tip part of division piece 1Ac which becomes tapered.

  FIG. 5 shows a third embodiment of the present invention. In the third embodiment, a bus bar 1B is used in place of the bus bar 1 in the first embodiment shown in FIGS. In the bus bar 1B, the slit 1Bb provided at the end 1Ba is not opened at the tip as in the slit 1b of FIG. 1, and is formed from the vicinity of the tip of the end 1Ba toward the base end side (the side opposite to the tip). It has a long hole shape. By forming the long hole-shaped slit 1Bb, the end 1Ba of the bus bar 1B is formed with a plurality of divided portions 1Bc along the width direction. The bus bar 3 is the same as that of the first embodiment.

  Also in the third embodiment, by using the vibrator 7 as shown in FIG. 3 and performing ultrasonic bonding for each divided portion 1Bc, bonding can be performed with weaker and smaller vibrations as in the first embodiment. Even a bus bar having a large cross-sectional area and mass can be ultrasonically bonded without using a large facility. In the third embodiment, the slit 1Bb has a long hole shape, and the tip of the end portion 1Ba is continuous in the width direction. For this reason, the strength and rigidity of the end portion 1Ba are higher than those of the bus bars 1 and 1A shown in FIGS. 1 and 4, and the work for ultrasonic bonding becomes easy.

  In the third embodiment, a long hole-shaped slit extending in the width direction may be provided instead of the long hole-shaped slit 1Bb extending in the longitudinal direction of the bus bar 1B. In this case, a plurality of divided portions extending along the width direction corresponding to the divided portion 1Bc are formed along the longitudinal direction of the bus bar 1B.

  FIG. 6 shows a fourth embodiment of the present invention. In the fourth embodiment, a bus bar 1C is used instead of the bus bar 1 in the first embodiment shown in FIGS. The bus bar 1C has a plurality of through holes 1Ch formed in the end 1Ca. Here, a total of 15 through-holes 1Ch in the longitudinal direction of the bus bar 1C and a total of 15 through-holes 3 at equal intervals in the width direction are provided in a lattice shape as a whole. The shape of the through hole 1Ch may be circular or polygonal.

  By providing a plurality of through holes 1Ch, the end portion 1Ca of the bus bar 1C is divided into a plurality of divided portions 1Cc formed between the through holes 1Ch. In addition, the division | segmentation site | part 1Cc here is the area | region between mutually adjacent through-holes 1Ch, and the area | region of the front end side and width direction both sides of the bus-bar 1C, and is equivalent to the area | region except the through-hole 1Ch in edge part 1Ca. To do. The bus bar 3 is the same as that of the first embodiment.

  Also in the fourth embodiment, by using the vibrator 7 as shown in FIG. 3 and performing ultrasonic bonding for each divided portion 1Cc, similar to the first embodiment, bonding can be performed with weaker and smaller vibration. Even a bus bar having a large cross-sectional area and mass can be ultrasonically bonded without using a large facility.

  In addition, the operation | work which carries out ultrasonic bonding for every division | segmentation site | part 1Cc here is as follows. The five through holes 1Ch along the longitudinal direction are arranged in one row, and four portions in total of two divided portions 1Cc corresponding to each other and two divided portions 1Cc on both sides in the width direction are connected to the bus bar 1C. Are sequentially joined along the width direction. Alternatively, three through-holes 1Ch along the width direction are arranged in one row, and five divided portions 1Cc corresponding to each other between the rows and one divided portion 1Cc on the front end side are arranged in a bus bar. Bonded sequentially along the longitudinal direction of 1C.

  Moreover, in 4th Embodiment, the front-end | tip of edge part 1Ca is continuing along the width direction similarly to 3rd Embodiment. For this reason, the strength and rigidity of the end portion 1Ca are higher than those of the bus bars 1 and 1A shown in FIGS. 1 and 4, and the work for ultrasonic bonding becomes easy.

  FIG. 7 shows a fifth embodiment of the present invention. In the fifth embodiment, a bus bar 1D is used instead of the bus bar 1 in the first embodiment shown in FIGS. The bus bar 1D is provided with a split piece 1Dc that is substantially the same as the split piece 1c of the bus bar 1 of FIG. 1 at its end 1Da, and further, with respect to the bus bar 3 on the other side in a superimposed state at the tip of the split piece 1Dc. A bending portion 1Dr serving as a heat radiating portion that bends at an angle of approximately 90 degrees toward the separating direction is provided. A slit 1Db is formed between the divided pieces 1Dc.

  The plurality of bent portions 1Dr that are adjacent to each other are displaced in the longitudinal direction of the bus bar 1D. Specifically, among the five bent portions 1Dr, three in total in the width direction both sides and the center in the width direction are located on the same straight line along the width direction, and are proximal to the other two Located on the opposite side of the tip. The other two bent portions 1Dr are located on the same straight line along the width direction, and are located closer to the tip than the other three. The bus bar 3 is the same as that of the first embodiment.

  Also in the fifth embodiment, the vibrator 7 as shown in FIG. 3 is used, and ultrasonic bonding is performed on the portion excluding the bent portion 1Dr for each divided piece 1Dc. Thereby, similarly to 1st Embodiment, it can join with a weaker and small vibration, and even if it is a bus bar with a large cross-sectional area and mass, it can ultrasonically join, without using a large sized installation.

  In the fifth embodiment, when heat generated in the stator of the motor is transmitted from the bus bar 1D to the inverter via the bus bar 3, the heat is radiated by the bent portion 1Dr of the bus bar 1D as a heat radiating fin. At that time, since the bent portions 1Dr are adjacent to each other in the longitudinal direction of the bus bar 1D, the heat dissipation effect is further enhanced.

  Thereby, the heat transmitted from the motor to the inverter can be reduced, and problems due to the high temperature of the inverter can be suppressed. In particular, in the electromechanical integrated structure in which the motor and the inverter are integrated, when the motor and the inverter are arranged close to each other, the amount of heat generated by the motor is transmitted to the inverter via the bus bar compared to the case where the motor and the inverter are not close to each other. Because it increases, the effect is great.

  FIG. 8 shows a sixth embodiment of the present invention. In the sixth embodiment, a bus bar 1E is used in place of the bus bar 1 in the first embodiment shown in FIGS. The bus bar 1E is provided with a split piece 1Ec and a slit 1Eb similar to the split piece 1c and the slit 1b of the bus bar 1 of FIG.

  However, the bus bar 1E is wider than the bus bar 1 of FIG. 1, and the number of the divided pieces 1Ec and the slits 1Eb is larger than that of the divided pieces 1c and the slits 1b, respectively. The widths of the divided pieces 1Ec and the slits 1Eb are substantially equal to the widths of the divided pieces 1c and the slits 1b of the bus bar 1, respectively.

  On the base end side of the above-described divided pieces 1Ec of the bus bar 1E that are overlapped with each other, a protruding portion 1Er that is a divided portion extending portion continuous with the divided piece 1Ec is formed. The protrusions 1Er are formed so as to be continuous with the plurality of divided pieces 1Ec, respectively, and the ones adjacent to each other in the width direction of the bus bar 1E are bent so as to protrude in the upside down direction. Specifically, among the plurality of protrusions 1Er, the first, third, fifth, seventh, ninth, and eleventh protrusions 1Er from the front side in FIG. 8 protrude upward, and in FIG. The fifth, fourth, sixth, eighth and tenth projecting portions 1Er from the front side of the paper surface project downward.

  As a result, the width of the divided piece 1Ec (protrusion 1Er) extends along the width direction between the first, third, fifth, seventh, ninth, and eleventh protrusions 1Er from the front side in FIG. And a width of the dimension obtained by adding the widths of the slits 1Eb at two locations on both sides of the divided piece 1Ec. Similarly, between the second, fourth, sixth, eighth, and tenth protrusions 1Er from the front side in FIG. 8, the width of the divided piece 1Ec (protrusion 1Er) along the width direction. An interval having a dimension obtained by adding the widths of the slits 1Eb at two positions on both sides of the divided piece 1Ec is formed. The counterpart bus bar 3E is substantially the same in width as the bus bar 1E, and is simply formed in a plate shape like the bus bar 3 of the first embodiment.

  Also in the sixth embodiment, by using the vibrator 7 as shown in FIG. 3 and performing ultrasonic bonding for each divided piece 1Ec, bonding can be performed with weaker and smaller vibrations as in the first embodiment. Even a bus bar having a large cross-sectional area and mass can be ultrasonically bonded without using a large facility.

  Further, in the sixth embodiment, similarly to the fifth embodiment, when heat generated in the stator of the motor is transferred from the bus bar 1E to the inverter via the counterpart bus bar 3E, the heat is projected from the bus bar 1E. 1Er radiates heat as a radiating fin. At that time, since the protrusions 1Er are adjacent to each other with the above-mentioned interval, the heat dissipation effect is further enhanced.

  Thereby, the heat transmitted from the motor to the inverter can be reduced, and problems due to the high temperature of the inverter can be suppressed. In particular, in the electromechanical integrated structure in which the motor and the inverter are integrated, when the motor and the inverter are arranged close to each other, the amount of heat generated by the motor is transmitted to the inverter via the bus bar compared to the case where the motor and the inverter are not close to each other. Because it increases, the effect is great.

  Further, in the sixth embodiment, the base end side of the end portion 1Ea of the bus bar 1E is compared with the case where the bent portion 1Dr serving as a heat radiating portion is formed at the tip as in the fifth embodiment shown in FIG. The protruding portion 1Er serving as a heat radiating portion can be formed in a large area. For this reason, the heat dissipation effect is further enhanced, and the heat transmitted from the motor to the inverter can be further reduced.

  FIG. 9 shows a seventh embodiment of the present invention. In the seventh embodiment, the tip (lower end in FIG. 9) of the transducer 70 which is a tool of an ultrasonic bonding machine is a convex curved surface shape portion 70a. In this case, the convex curved surface shape portion 70a has a spherical shape. The bus bars 1 and 3 are the same as those in the first embodiment shown in FIG.

  In the seventh embodiment, in a state where the vibrator 70 is tilted as shown in FIG. 9A, the convex curved surface portion 70a is pressed against the divided piece 1c located at the end portion to apply ultrasonic vibration, and thereafter 9B and 9C, the entire vibrator 70 is swung clockwise in FIG. By swinging the vibrator 70, the convex curved surface shape portion 70a moves so as to roll on the plurality of divided pieces 1c. At that time, the vibrator 70 is pressed against one divided piece 1c for a predetermined time. Thereby, the five divided pieces 1c arranged along the width direction of the bus bar 1 are sequentially ultrasonically bonded to the bus bar 3 by ultrasonic vibration.

  As described above, in the seventh embodiment, the entire curved surface of the vibrator 70 is configured such that the convex curved surface-shaped portion 70a of the vibrator 70 is pressed as it is on the end portion 1a including the divided piece 1c of the bus bar 1 as it is rolled. Rock. Thereby, ultrasonic bonding can be sequentially and sequentially performed on the plurality of divided pieces 1c. Therefore, as in the first embodiment shown in FIG. 3, the working time can be shortened compared to the case where the work of pressing the vibrator 7 against the plurality of divided pieces 1c and the work of separating them are repeated. This improves the workability.

  As mentioned above, although embodiment of this invention was described, these embodiment is only the illustration described in order to make an understanding of this invention easy, and this invention is not limited to the said embodiment. The technical scope of the present invention is not limited to the specific technical matters disclosed in the above embodiment, but includes various modifications, changes, alternative techniques, and the like that can be easily derived therefrom.

  For example, in the above-described embodiment, a motor and an inverter have been described as examples of electrical devices to be electrically connected when ultrasonically joining bus bars to each other. However, the present invention can also be applied to other electrical devices. it can.

  Further, in the above-described embodiment, the mating bus bars 3 and 3E to be ultrasonically bonded to the bus bars 1 and 1A to 1E having the divided portions are simply flat plate shapes, but are similar to the bus bars 1 and 1A to 1E. It is good also as what has division parts, such as division piece 1c. That is, in this case, ultrasonic bonding is performed in a state where the divided portions of the bus bars 1, 1A to 1E are overlapped with the divided portions of the bus bars 3, 3E.

1, 1A, 1B, 1C, 1D, 1E Bus bar 1a, 1Aa, 1Ba, 1Ca, 1Da, 1Ea Bus bar end 1b, 1Ab, 1Bb, 1Db, 1Eb Slit 1c, 1Ac, 1Dc, 1Ec Divided piece (divided part)
1Bc, 1Cc Dividing part 1Ch Through-hole 1Dr Bending part 1Er Protruding part 3, 3E Bus bar 3a End of bus bar 70 Vibrator whose tip is convexly curved

Claims (11)

A bus bar joining structure in which a pair of plate-like bus bars are ultrasonically joined in a state where they are overlapped with each other,
The bus bar joining structure characterized in that at least one of the pair of plate-like bus bars overlaps with a divided part.   The bus bar joining structure according to claim 1, wherein the divided part of the bus bar is formed by a slit provided in a part of the bus bar that is overlapped with each other.   The bus bar joining structure according to claim 2, wherein the slit is extended from a distal end portion of the bus bar toward a proximal end side.   4. The bus bar joining structure according to claim 3, wherein the slit has an opening at a front end portion of the bus bar and extends from the open end portion toward the base end side.   The bus bar joint structure according to claim 4, wherein the divided portion has a smaller dimension in the width direction toward the distal end side.   The bus bar joining structure according to claim 3, wherein the slit has a long hole shape extending from the vicinity of the front end of the bus bar toward the base end side.   The plurality of through-holes are provided in a lattice shape in a portion of the bus bar that is overlapped with each other, and the divided portion of the bus bar is formed between the plurality of through-holes. Bus bar joint structure.   6. The bus bar joint structure according to claim 4, further comprising a bent portion that bends in a direction in which a tip of the divided portion is separated from the bus bar on the other side. On the base end side with respect to the divided portions of the bus bar that are overlapped with each other, a divided portion extension portion that is continuous with the divided portion is formed,
6. The bus bar joint structure according to claim 4, wherein the divided portion extension portion includes a protruding portion that bends so that those adjacent to each other in the width direction of the bus bar protrude in the opposite direction. A bus bar joining method in which a pair of plate-like bus bars are ultrasonically joined to each other in a superposed state,
The part where at least one of the pair of plate-shaped bus bars is superimposed includes a divided part that is divided into a plurality of parts,
A bus bar joining method, wherein ultrasonic joining is performed for each of the plurality of divided portions.   By moving a vibrator having a convex curved tip at a surface pressed against the surface of the bus bar provided with the divided portions, the plurality of divided portions are continuously ultrasonically moved. The bus bar joining method according to claim 10, wherein joining is performed.

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