JP5387425B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device configured by stacking a plurality of semiconductor modules and a cooling tube.

  As a power conversion device that performs power conversion between DC power and AC power, as shown in FIG. 13, a plurality of semiconductor modules 91 incorporating switching elements, and a plurality of cooling tubes 92 that cool the semiconductor modules 91. (See Patent Document 1 below). Each semiconductor module 91 includes a control terminal 96 and a power terminal 93 that are electrically connected to the switching element.

The power terminal 93 includes a positive terminal 93a connected to the positive electrode of the DC power supply, a negative terminal 93b connected to the negative electrode of the DC power supply, and an AC terminal 93c connected to the AC load. A bus bar 95 is welded to the power terminal 93.
A control circuit board 99 is connected to the control terminal 96. This control circuit board 99 controls the operation of the switching elements in the semiconductor module 91. As a result, the DC voltage applied between the positive terminal 93a and the negative terminal 93b is converted into alternating current and output from the alternating current terminal 93c.

  A connection portion 94 for connecting to the bus bar 95 is formed on the side portion of the power terminal 93. As shown in FIG. 14A, the angle θ formed between the power terminal 93 and the connection portion 94 is an obtuse angle before the connection portion 94 and the bus bar 95 are connected. 14B, the connecting portion 94 is pressed against the bus bar 95, and the connecting portion 94 is bent and connected to the bus bar 95. Accordingly, even when the semiconductor module 91 is displaced in the y direction in FIG. 14B, the bus bar 95 and the connection portion 94 are in close contact with each other. In this way, by bringing the connecting portion 94 and the bus bar 95 into close contact, the subsequent welding process to the end surface 94a of the connecting portion 94 can be performed smoothly.

JP 2009-142000 A

  However, the conventional power converter 90 cannot sufficiently lengthen the length L of the connecting portion 94 (see FIG. 14B). This is because if the length L is too long, the connecting portion 94 interferes with the adjacent power terminal 93 as shown in FIG. Therefore, the length L of the connecting portion 94 has to be shortened, and it becomes difficult to deform, and it may be difficult to bring the bus bar 95 and the connecting portion 94 into close contact with each other. Therefore, the welding process between the bus bar 95 and the connecting portion 94 may not be performed smoothly.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a power conversion device that can easily weld a power terminal and a bus bar.

The present invention includes a main body portion having a built-in switching element constituting a power conversion circuit, a plurality of semiconductor modules in which power terminals conducted to the switching element protrude from an end surface of the main body portion, and the semiconductor module as described above. A laminate in which a plurality of cooling tubes for cooling from both main surfaces of the main body are laminated;
A bus bar welded to the power terminal,
The power terminal is formed of a metal plate, and the power terminal protrudes from the main body and has a main surface parallel to the main surface of the main body and the tip of the terminal main body. A connecting portion protruding in the stacking direction of the laminate,
The connection portions of the plurality of power terminals arranged in the stacking direction and the bus bar are connected with their main surfaces facing each other, and the bus bar is pressed by the connection portion. It is elastically deformed in the thickness direction of the bus bar ,
The bus bar includes a positive electrode bus bar connected to a positive electrode terminal of a DC power source and a negative electrode bus bar connected to a negative electrode terminal of the DC power source, and the positive electrode bus bar and the negative electrode bus bar are spaced at a predetermined interval in the plate thickness direction. Placed opposite each other,
The positive electrode bus bar and the negative electrode bus bar are respectively welded to the connection part,
The positive electrode bus bar and the negative electrode bus bar are respectively deformed in the same direction by being pressed by the connecting portion (claim 1).

The function and effect of the present invention will be described. In the present invention, the power terminal has a structure having the terminal body portion and the connection portion. Further, the connecting portion is pressed against the bus bar so that the bus bar is elastically deformed in the thickness direction.
When the bus bar is deformed in this way, the welding operation of the power terminal and the bus bar can be easily performed. That is, when the power terminal side is deformed (see FIGS. 13 and 14), as described above, the length L of the connecting portion 94 in the stacking direction x is limited in design, and thus the connecting portion 94 must be shortened. I do not get. For this reason, the rigidity of the connecting portion 94 is increased and it is difficult to deform. On the other hand, since the bus bar is not limited as described above, it can be easily designed to obtain sufficient elastic deformation. By deforming the bus bar in this manner, the connection portion and the bus bar can be easily brought into close contact with each other, and these welding operations can be easily performed.

  Further, the positions of the individual semiconductor modules constituting the stacked body may vary somewhat in the thickness direction of the bus bar. In the present invention, since the bus bar is elastically deformed, even if the position of the semiconductor module varies in the plate thickness direction, the connection portion and the bus bar are easily brought into close contact with each other. Therefore, the connection portion and the bus bar can be easily welded.

  Moreover, in this invention, the connection part and the bus-bar are connected in the state which mutually opposed the main surface. Therefore, even if the position of the semiconductor module varies in the laminating direction, or even when the position varies in the direction perpendicular to both the laminating direction and the plate thickness direction, the connecting portion only moves parallel to the bus bar. These can be easily connected.

  Thus, according to the present invention, the connection portion of the power terminal and the bus bar can be easily brought into close contact with each other regardless of the direction of the position of the semiconductor module. Thereby, it becomes possible to weld a connection part and a bus-bar easily.

  As described above, according to the present invention, it is possible to provide a power converter that easily welds the power terminal and the bus bar.

FIG. 3 is a perspective view of the power conversion device according to the first embodiment, and is a perspective view of a state before connecting a power terminal and a bus bar. It is a perspective view of the power converter in Example 1, Comprising: The perspective view of the state which connected the power terminal to the bus bar. FIG. 3 is an A arrow view of FIG. 2. The top view of the bus bar in Example 1. FIG. The enlarged view which looked at the power terminal and bus bar in FIG. 2 from the X direction. The circuit diagram of the power converter device in Example 1. FIG. FIG. 9 is a plan view of a bus bar according to the second embodiment, and is a view seen from an arrow C in FIG. BB sectional drawing of FIG. The top view of the bus bar in Example 3. FIG. FIG. 9 is a perspective view of a power conversion device according to a fourth embodiment, and is a perspective view of a state before connecting a power terminal and a bus bar. It is a top view of the bus bar in Example 4, Comprising: The E arrow line view of FIG. DD sectional drawing of FIG. The disassembled perspective view of the power converter device in a prior art example. It is the enlarged view of the power converter device seen from the Z direction of FIG. 13, Comprising: (A) The enlarged view before a connection of a bus bar and a power terminal (B) The enlarged view after the connection of a bus bar and a power terminal.

A preferred embodiment of the present invention described above will be described.
In the present invention, it is preferable that the bus bar has a small rigidity portion that is partially small in rigidity, and the small rigidity portion is configured to be deformed in the plate thickness direction.
If it does in this way, it will become easy to change a bus bar in a small rigidity part. Thereby, it becomes easy to make a bus bar and a connection part closely_contact | adhere, and it becomes easy to perform a welding process.

Further, it is preferable to form the small rigidity portion by partially reducing the thickness of the bus bar.
In this case, the small rigidity portion can be formed by partially reducing the thickness of the bus bar. In order to reduce the thickness of the bus bar, for example, grinding can be performed. Since grinding can be performed at low cost, the manufacturing cost of the bus bar can be reduced.

Further, a plurality of slits extending in the direction perpendicular to both the plate thickness direction and the laminating direction are formed in the side portion of the bus bar in the laminating direction, and two adjacent slits in the laminating direction are formed. It is preferable that the connecting portion is in contact with the main surface of the protruding portion formed between the slits, and the small rigidity portion is formed at the root portion of the protruding portion.
In this case, it is possible to manufacture a bus bar that is easily elastically deformed in the thickness direction only by performing a simple process of slitting the bus bar. That is, with the above structure, the protrusion formed between two adjacent slits is easily elastically deformed near the root. Moreover, according to the said structure, the process of making thin the plate | board thickness of the base part of a protrusion part etc. can be performed collectively. Therefore, the bus bar can be further elastically deformed. Thereby, it becomes easy to adhere | attach the connection part of a power terminal and a bus bar, and it becomes possible to perform these welding much more easily.

Moreover, it is preferable that the root portion of the protruding portion has a cutout portion cut out from at least one side in the stacking direction.
If it does in this way, it will become easy to change the base part of a projection part. Therefore, it becomes easy to closely contact the connection portion of the power terminal and the bus bar, and the welding process can be further facilitated.

The bus bar includes a positive bus bar connected to the positive terminal of the DC power source and a negative bus bar connected to the negative terminal of the DC power source. The positive bus bar and the negative bus bar are predetermined in the plate thickness direction. that it is opposed spaced apart.
Therefore , the parasitic inductance generated between the positive electrode bus bar and the negative electrode bus bar can be reduced. Thereby, when the switching element is operated, a surge voltage generated between the terminals of the switching element can be reduced. Therefore, the switching element is not easily destroyed.

Example 1
A power converter according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 2 and 3, the power conversion device 1 of this example includes a stacked body 4 in which a plurality of semiconductor modules 2 and a cooling tube 3 are stacked. Each of the semiconductor modules 2 has a main body 20 that incorporates a switching element that constitutes a power conversion circuit, and a power terminal 6 that is electrically connected to the switching element protrudes from an end surface of the main body 20. The cooling tube 3 cools the semiconductor module 2 from both main surfaces of the main body 20.

The power converter 1 includes a bus bar 5 welded to the power terminal 6.
The power terminal 6 is formed from a metal plate. The power terminal 6 protrudes from the main body 20 and has a main body 600 (see FIG. 3) parallel to the main surface 200 of the main body 20, and a stack of the laminate 4 from the tip of the terminal main body 60. And a connecting portion 61 protruding in the direction X.
As shown in FIGS. 2 and 3, the connection portions 61 of the plurality of power terminals 6 arranged in the stacking direction X and the bus bar 5 are connected in a state where the main surfaces 601 and 501 face each other. Further, as shown in FIG. 5, the bus bar 5 is elastically deformed in the plate thickness direction Y of the bus bar 5 by being pressed by the connecting portion 61.
The details will be described below.

  As shown in FIG. 2, two semiconductor modules 2 are interposed between two adjacent cooling tubes 3. Each semiconductor module 2 includes two power terminals 6 and a control terminal 21. The power terminal 6 includes a positive terminal 6a connected to the positive electrode of the DC power supply, a negative terminal 6b connected to the negative electrode of the DC power supply, and an AC terminal 6c connected to the AC load. The bus bar 5 is welded to the positive terminal 6a and the negative terminal 6b. Further, another bus bar (not shown) is also welded to the AC terminal 6c.

  A control circuit board (not shown) is connected to the control terminal 21 of the semiconductor module 2. The control circuit board controls the operation of the switching element in the semiconductor module 2. Thereby, the direct current voltage applied between the positive electrode terminal 6a and the negative electrode terminal 6b is converted into alternating current, and is output from the alternating current terminal 6c.

  The power terminal 6 is formed by bending a metal plate at a right angle to form a terminal main body portion 60 and a connection portion 61. As shown in FIG. 2, the terminal body 60 of the positive terminal 6a is longer in the Y direction than the terminal body 60 of the negative terminal 6b. Further, the connecting portion 61 of the positive electrode terminal 6a and the connecting portion 61 of the negative electrode terminal 6b have substantially the same length in the X direction.

  When manufacturing the power converter 1, the laminated body 4 is assembled first. Then, as shown in FIG. 5, the bus bar 5 is disposed slightly obliquely with respect to the connection portion 61, and the connection portion 61 is pressed against the bus bar 5. Then, the bus bar 5 is elastically deformed in the plate thickness direction Y, and the main surface 601 of the connection portion 61 is brought into close contact with the main surface 501 of the bus bar 5 on the end surface 610 side of the connection portion 61. Thereafter, a welding process is performed between the end surfaces 610 and 510.

As shown in FIGS. 2 and 4, the bus bar 5 of this example has a small rigidity portion 7 having a partially small rigidity, and the small rigidity portion 7 is configured to be deformed in the plate thickness direction.
As shown in FIGS. 2 and 4, a plurality of slits 50 extending in the direction Z perpendicular to both the plate thickness direction Y and the stacking direction X are formed in the side portion of the bus bar 5 in the stacking direction X. And the connection part 61 contact | abuts to the main surface 501 of the protrusion part 51 formed between the two slits 50 adjacent to the lamination direction X. FIG. Further, the base portion 52 of the protruding portion 51 is elastically deformed in the plate thickness direction Y. That is, the small rigidity portion 7 is formed at the root portion 52 of the protruding portion 51.

  As shown in FIG. 2, the bus bar 5 includes a positive bus bar 5a connected to the positive terminal of the DC power source and a negative bus bar 5b connected to the negative terminal of the DC power source. The positive bus bar 5a and the negative bus bar 5b Are arranged opposite to each other at a predetermined interval in the plate thickness direction Y.

  On the other hand, as shown in FIG. 2, two adjacent cooling tubes 3 are connected by connecting pipes 42 at both ends in the Z direction. When the refrigerant is introduced from the introduction pipe 40, the refrigerant flows through all the cooling tubes 3 through the connection pipe 42 and is led out from the outlet pipe 41. Thereby, the semiconductor module 2 is cooled.

Next, a circuit diagram of the power conversion device 1 of the present invention will be described. As shown in FIG. 6, the power conversion device 1 includes a converter unit 10 a and an inverter unit 10 b. As shown in FIG. 6, the converter unit 10 a and the inverter unit 10 b are composed of a plurality of semiconductor modules 2. Each semiconductor module 2 includes a switching element 23 (IGBT element) and a free wheel diode 24.
Converter unit 10 a boosts the voltage of DC power supply 11. The inverter unit 10b converts the boosted DC voltage into an AC voltage by the switching operation of the switching element 23, and outputs the AC voltage from the AC terminal 6c.
The power conversion device 1 of this example is mounted on a vehicle such as a hybrid car or an electric vehicle. A three-phase AC motor 12 is mounted on the vehicle. The AC power obtained by the power converter 1 is used to drive the three-phase AC motor 12 to drive the vehicle.

The effect of this example will be described.
In this example, the connecting portion 61 of the power terminal 6 is pressed against the bus bar 5 to elastically deform the bus bar 5 in the plate thickness direction Y.
If it does in this way, it will become possible to perform the welding operation of the power terminal 6 and the bus-bar 5 easily. That is, when the power terminal is deformed (see FIGS. 13 and 14), if the length L of the connecting portion 94 in the stacking direction x is excessively long, it interferes with the adjacent power terminal. Must be shortened. For this reason, the rigidity of the connecting portion 94 is increased, and it may be difficult to bend. On the other hand, since the bus bar 5 is not limited as described above, it is easy to design for obtaining sufficient elastic deformation. For example, in this example, as shown in FIG. 4, the slit 50 is inserted in the side portion of the bus bar 5 and the protruding portion 51 formed between the slits 50 is elastically deformed. However, the length L1 of the slit 50 is increased. By doing so, the protrusion 51 can be easily deformed. By deforming the bus bar 5 in this manner, the connecting portion 61 and the bus bar 5 can be easily brought into close contact with each other, and these welding operations can be easily performed.

  Further, the positions of the individual semiconductor modules 2 constituting the stacked body 4 may vary somewhat in the plate thickness direction Y (see FIG. 2). In this example, since the bus bar 5 is elastically deformed, even if the position of the semiconductor module 2 varies in the plate thickness direction Y, the connecting portion 61 and the bus bar 5 are easily brought into close contact with each other. Therefore, the connection part 61 and the bus bar 5 can be easily welded.

  Moreover, in this example, as shown in FIG. 2, the connection part 61 and the bus-bar 5 are connected in the state which mutually opposed the main surfaces 601 and 501. Therefore, even when the position of the semiconductor module 2 varies in the stacking direction X or in the Z direction, the connecting portion 61 only moves in parallel with the bus bar 5, so that these can be easily connected. .

  As described above, in this example, the connection portion 61 of the power terminal 6 and the bus bar 5 can be easily brought into close contact with each other even when the position of the semiconductor module 2 varies in any of the X direction, the Y direction, and the Z direction. . Thereby, the connection part 61 and the bus bar 5 can be easily welded.

In this example, as shown in FIG. 2, a small rigidity portion 7 having a small rigidity is formed on the bus bar 5.
If it does in this way, it will become easy to change bus bar 5 in small rigidity part 7. Thereby, it becomes easy to make the bus-bar 5 and the connection part 61 closely_contact | adhere, and it becomes easy to perform a welding process.

More specifically, as shown in FIGS. 2 and 4, in this example, a plurality of slits 50 extending in the Z direction are formed on the side portion of the bus bar 5 in the X direction. And the base part 52 of the protrusion part 51 formed between the two adjacent slits 50 was made to elastically deform in the Y direction.
If it does in this way, the bus bar 5 which is easy to elastically deform in the plate | board thickness direction Y can be manufactured only by performing the simple process of putting the slit 50 in the bus bar 5. FIG. Moreover, according to the said structure, the process of making thin the plate | board thickness of the base part 52 of the protrusion part 51 etc. can be performed collectively. Therefore, the bus bar 5 can be further elastically deformed. Thereby, it becomes easy to make the connection part 61 of the power terminal 6 and the bus-bar 5 closely_contact | adhere, and it becomes possible to perform these welding much more easily.

In this example, the positive electrode bus bar 5a and the negative electrode bus bar 5b connected to the power terminal 6 are arranged to face each other with a predetermined interval in the plate thickness direction Y.
If it does in this way, the parasitic inductance produced between the positive electrode bus bar 5a and the negative electrode bus bar 5b can be made small. Thereby, when the switching element 23 is operated, a surge voltage generated between the terminals of the switching element 23 can be reduced. Therefore, the switching element 23 is not easily destroyed. In addition, there is an advantage that the capacitor 13 (see FIG. 6) can be reduced.

  As described above, according to this example, it is possible to provide the power conversion device 1 in which the power terminal 6 and the bus bar 5 can be easily welded.

(Example 2)
In this example, the shape of the bus bar 5 is changed. As shown in FIGS. 7 and 8, in this example, a plurality of slits 50 extending in the Z direction are formed in the X direction on the side portion of the bus bar 5. And in the base part 52 of the protrusion part 51 formed between two adjacent slits 50, the plate | board thickness of the bus-bar 5 was partially made thin.
In this case, since the thickness of the root portion 52 of the protruding portion 51 is thin, the root portion 52 is easily elastically deformed when the connecting portion 61 is pressed against the protruding portion 51. Therefore, the connection portion 61 and the bus bar 5 are easily brought into close contact with each other, and the connection portion 61 and the bus bar 5 are easily welded.
In addition, the configuration and operational effects are the same as those of the first embodiment.

(Example 3)
In this example, the shape of the bus bar 5 is changed. As shown in FIG. 9, in this example, the root portion 52 of the protruding portion 51 has a cutout portion 53 cut out from at least one side in the stacking direction X.
In this way, the root portion 52 of the protrusion 51 is more easily deformed. For this reason, the connecting portion 61 of the power terminal 6 and the bus bar 5 are easily brought into close contact with each other, and these weldings can be performed more easily.
In addition, the configuration and operational effects are the same as those of the first embodiment.

Example 4
In this example, the shape of the bus bar 5 is changed. As shown in FIGS. 10 to 12, the bus bar 5 of this example has a plate shape, is not formed with a slit portion, and is formed with a recess 54 extending in the X direction at a position slightly away from the end surface 520. The thin portions 54 a and 54 b are elastically deformed by being pressed by the connection portion 61 of the power terminal 6.
In this way, it is not necessary to form a slit in the bus bar 5. Moreover, the recessed part 54 can be formed, for example by grinding. Since grinding can be performed at low cost, the manufacturing cost of the bus bar 5 can be reduced.

DESCRIPTION OF SYMBOLS 1 Power converter 2 Semiconductor module 20 Main body part 3 Cooling tube 4 Laminated body 5 Bus bar 6 Power terminal 60 Terminal main body part 61 Connection part

Claims (5)

A main body having a switching element constituting a power conversion circuit; a plurality of semiconductor modules in which power terminals connected to the switching element protrude from an end surface of the main body; and A laminate in which a plurality of cooling tubes cooled from the main surface are laminated;
A bus bar welded to the power terminal,
The power terminal is formed of a metal plate, and the power terminal protrudes from the main body and has a main surface parallel to the main surface of the main body and the tip of the terminal main body. A connecting portion protruding in the stacking direction of the laminate,
The connection portions of the plurality of power terminals arranged in the stacking direction and the bus bar are connected with their main surfaces facing each other, and the bus bar is pressed by the connection portion. It is elastically deformed in the thickness direction of the bus bar ,
The bus bar includes a positive electrode bus bar connected to a positive electrode terminal of a DC power source and a negative electrode bus bar connected to a negative electrode terminal of the DC power source, and the positive electrode bus bar and the negative electrode bus bar are spaced at a predetermined interval in the plate thickness direction. Placed opposite each other,
The positive electrode bus bar and the negative electrode bus bar are respectively welded to the connection part,
The positive electrode bus bar and the negative electrode bus bar are each deformed in the same direction by being pressed by the connecting portion .   2. The power conversion device according to claim 1, wherein the bus bar has a small rigidity portion having a partially small rigidity, and the small rigidity portion is configured to be deformed in the plate thickness direction.   3. The power conversion device according to claim 2, wherein the thickness of the bus bar is partially reduced to form the small rigidity portion.   The slits extending in a direction orthogonal to both the plate thickness direction and the laminating direction are formed in a side portion of the bus bar in the laminating direction and adjacent to the laminating direction. The power conversion device according to claim 1, wherein the connecting portion is in contact with a main surface of a protruding portion formed between two slits, and the small rigidity portion is formed at a root portion of the protruding portion.   5. The power conversion device according to claim 4, wherein the base portion of the protruding portion has a cutout portion cut out from at least one side in the stacking direction.

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