Bus bar fixing structure, and power conversion device

Abstract

To provide a bus bar fixing structure in which a bus bar is fixed to a terminal block of a power conversion device without bolt fastening or screwing, to enhance work efficiency and manufacturing cost suppression.SOLUTION: A bus bar holder 3 is used when PN bus bars 10 and 11 are fixed to a terminal block 2 of an inverter device 1. A round groove 13 is formed at the approximately center of a base portion 3a of the bus bar holder 3. A hole part 13b is formed on a groove bottom 13a of the round groove 13. Also, the PN terminal block 2 has a receiver for a push rivet 20 formed at a position corresponding to the hole part 13b. Each leg portion 26 of the push rivet 20 is engaged with the receiver through the hole part 13b to fix the PN bus bars 10 and 11 to the PN terminal block 2.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a structure for fixing a bus bar to a terminal block using a bus bar holder and a power conversion device including the structure.

Background Art

[0002] In FIG. 1, reference numeral 1 denotes an inverter device used in a rotary machine drive device or the like. In an inverter device, a DC capacitor C and switching elements S1 to S6 are often connected using a bus bar having low inductance and low impedance characteristics.

[0003] Patent Document 1 is known as a technique using this bus bar. By applying this bus bar, (1) suppression of overvoltage breakdown due to reduction of surge voltage during the switching operation of the switching elements S1 to S6, and (2) effects of reducing power loss and improving device efficiency due to reduction of the impedance of the bus bar are obtained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In Fig. 2, 2 indicates the PN terminal block, which corresponds to the mating component when connecting the DC input harness to the inverter housing to supply DC voltage from an external battery to the inverter device 1. The P and N poles of the harness and the PN bus bars 10, 11 are clamped together with screws (not shown) through the through holes 15, 16 provided in the PN bus bars 10, 11, enabling the harness and the PN bus bars 10, 11 to be energized.

[0007] Also, 3 in Fig. 2 indicates the bus bar holder used when fixing the PN bus bars 10, 11 to the PN terminal block. This bus bar holder 3 is adopted to hold the PN bus bars 10, 11 against the PN terminal block 2 to reduce the assembly variation. The PN terminal block 2 and the bus bar holder 3 are made of an insulating material such as resin, and the bus bar holder 3 also facilitates the alignment of the PN bus bars 10, 11 with the PN terminal block 2.

[0008] As a method of fixing the bus bar holder 3 to the PN terminal block 2, bolt fastening or screwing is common. Therefore, through holes (not shown) for inserting the shaft portions of bolts and screws are formed in the PN terminal block 2 and the bus bar holder 3.

[0009] Fig. 2 shows the fixing method by bolt fastening. The bus bar holder 3 is fixed to the PN terminal block 2 by tightening a nut (not shown) from the back side (opposite side of the bus bar holder 3) of the PN terminal block 2 onto the shaft portion of the bolt 12 inserted through the through hole.

[0010] In this fixing method, chips are generated when tightening the nut onto the shaft portion of the bolt 12 and may scatter into the inverter housing. Therefore, a chip prevention cap (not shown) was attached to the head of the bolt 12 during tightening. However, not only is a tool such as a driver required, but the number of working steps also increases, which may make it difficult to improve work efficiency and control manufacturing costs.

[0011] The present invention is made to solve such conventional problems, and has as its problem to be solved the fixation of a bus bar to a terminal block of a power conversion device without bolt fastening or screwing, thereby achieving work efficiency improvement and manufacturing cost reduction.

Means for Solving the Problems

[0012] The present invention is a structure for fixing a bus bar to a terminal block of a power conversion device, a bus bar holder for pressing the bus bar against the terminal block, a push rivet inserted through a hole portion of the bus bar holder, and a receiving portion formed in the terminal block for locking the push rivet, and is characterized in that, after inserting the push rivet through the hole portion and locking it to the receiving portion, the bus bar is sandwiched and fixed between the terminal block and the bus bar holder. This bus bar holder can be made of resin, and a power conversion device having the above structure also constitutes the present invention.

Effects of the Invention

Advantages of the Invention

[0013] According to the present invention, a bus bar can be fixed to a terminal block of a power conversion device without bolt fastening or screwing, making it possible to improve work efficiency and reduce manufacturing costs.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0015] Hereinafter, the bus bar fixing structure according to an embodiment of the present invention will be described based on the examples shown in FIGS. 3 to 5. In this example, the same reference numerals are used for the same configurations as in FIGS. 1 and 2.

[0016] The bus bar fixing structure is used, for example, to fix the PN bus bars 10 and 11 to the PN terminal block 2 of the inverter device 1 mounted on an electric vehicle. This inverter device 1 is housed in an installed inverter housing, receives power from an external battery by the PN terminal block 2 inside the device, and supplies DC power to the switching elements S1 to S6 and the DC capacitor C via the PN bus bars 10 and 11.

[0017] The PN bus bars 10 and 11 in FIGS. 3 and 4 indicate bus bars that form a line connecting the P terminal or N terminal on the basic configuration circuit shown in FIG. 1 and the DC capacitor C, and have a primary-side capacitor connection screw terminal portion and secondary-side screw terminal portions 10a and 11a connected to the DC input harness. Here, the portions of the screw terminal portions 10a and 11a are referred to as the PN bus bars 10a and 11a.

[0018] The PN bus bars 10a and 11a and the harness are fixed to the PN terminal block 2 by bolts or the like. However, since the PN bus bars 10a and 11a and the PN terminal block 2 have an outsert structure (a structure of being embedded in a molded resin product), it is necessary to fix the positions of the PN bus bars 10a and 11a to the PN terminal block 2 until the DC input harness is fastened. At this time, in this example, the bus bar holders 3 are used to fix the PN bus bars 10a and 11a in the same manner as in FIG. 2.

[0019] However, it is different in that the work efficiency is improved and the manufacturing cost is reduced by fixing the PN busbars 10a and 11a to the PN terminal block 2 without using the bolts 12. That is, in this embodiment, as shown in FIG. 3, the method of fixing the busbar holder 3 to the PN terminal block 2 by bolt fastening and screwing is abolished, and the fixing method by locking the resin push rivet (clip) 20 shown in FIG. 5 is adopted. Note that the PN terminal block 2 and the busbar holder 3 are made of an insulating material such as resin as described above.

[0020] As shown in FIG. 4, the busbar holder 3 is formed in a substantially U shape, and includes a base 3a formed with a circular groove 13 substantially at the center, and both end portions 3b bent to the left and right of the base 3a, and the PN terminal block 2 is held by the both end portions 3b.

[0021] A hole portion 13b through which the push rivet 20 is inserted is formed through the groove bottom 13a of the circular groove 13. Here, a receiving portion (not shown) for the push rivet 20 is resin-molded on the PN terminal block 2 at a position corresponding to the hole portion 13b. This receiving portion only needs to be able to lock the leg portion 26 (see FIG. 5) of the push rivet 20, and can be formed, for example, as a through hole or a groove portion (groove hole) communicating with the hole portion 13b. The through holes of the PN terminal block 2 and the busbar holder 3 formed for conventional bolt fastening may be used as the hole portion 13b and the receiving portion. In this regard, it can be used generally.

[0022] An example of the push rivet 20 will be described with reference to FIG. 5. This push rivet 20 includes a rivet body 21 and a pin 22. A flange portion 23 is provided around the rivet body 21, while the shaft portion 22b of the pin 22 is press-fitted from the upper end opening of the rivet body 21. Here, the rivet body 21 includes a plurality of leg portions 26 divided by a slit 25, and tapered protrusions (not shown) are formed on the inner surfaces of the respective leg portions 26.

[0023] Further, a recess (not shown) that engages with the protrusion is formed in the shaft portion 22b of the pin 22. By pushing in the head portion 22a of the pin 22, the shaft portion 22b moves along each leg portion 26, and the recess engages with the protrusion, causing each leg portion 26 to elastically deform outward in an open-leg shape. However, since the push rivet 20 only needs to be locked to the receiving portion, it is not limited to the configuration of FIG. 5, and for example, various known types of push rivets described in Patent Documents 2 and 3 and Non-Patent Document 1 can be used.

[0024] According to such an embodiment, when fixing the PN busbars 10a and 11a to the PN terminal block 2, first, the PN busbars 10a and 11a are arranged between the PN terminal block 2 and the busbar holder 3. Next, the leg portions 26 of the push rivet 20 are inserted through the hole portions 13b and screwed into the receiving portion of the PN terminal block 2, and the flange portion 23 is brought into contact with the peripheral portion (groove bottom 13a) of the opening of the hole portion 13b.

[0025] Thereafter, as shown in FIG. 3, when the head portion 22a of the pin 22 is pushed in and the shaft portion 22b is press-fitted into the rivet body 21, the recess engages with the protrusion, causing each leg portion 26 to elastically deform outward in an open-leg shape. As a result, each leg portion 26 is locked to the inner circumference of the receiving portion, and the busbar holder 3 is fixed to the PN terminal block 2. At this time, the PN busbars 10a and 11a are sandwiched between the PN terminal block 2 and the busbar holder 3, and the PN busbars 10a and 11a are fixed to the PN terminal block 2, obtaining the following effects.

[0026] (1) That is, according to this embodiment, by pressing the PN busbars 10a and 11a against the PN terminal block 2 with the resin-made busbar holder 3, it is possible to solve the problem of displacement of the PN busbars 10a and 11a while adopting insert molding.

[0027] (2) At this time, since the bus bar holder 3 is fixed to the PN terminal block by the push rivet 20, tools such as drivers, nuts, and chip prevention caps used for bolt fastening or screwing are not required. Therefore, the number of parts required for fixing the PN bus bars 10a and 11a can be reduced, thereby improving the work efficiency and suppressing the manufacturing cost compared to the conventional method.

[0028] (3) Also, it is only necessary to fit the push rivet 20 into the receiving part and push in the head 22a of the pin 22, so the PN bus bars 10a and 11a can be easily fixed to the PN terminal block 2. Therefore, the manufacturing process can be simplified compared to the conventional method, and the assemblability of the PN bus bars 10a and 11a is improved.

[0029] In this regard, the work efficiency and the manufacturing cost can also be reduced. According to this embodiment, it is possible to achieve both the fixing function of the PN bus bars 10a and 11a and the improvement of work efficiency and suppression of manufacturing cost.

[0030] Note that the present invention is not limited to the above-described embodiment and can be implemented with modifications within the scope described in each claim. For example, it can be applied not only to the PN bus bars 10 and 11 but also to the fixing of terminal blocks such as the three-phase output bus bar of an inverter device, and can also be applied to power conversion devices other than inverter devices such as choppers. Furthermore, a power conversion device such as an inverter device provided with the fixing structure of this embodiment (an inverter device using the fixing structure) also naturally constitutes the present invention.

Explanation of Reference Numerals

[0031] 1... Inverter device 2... PN terminal block 3... Bus bar holder 10, 11... PN bus bars 13b... Hole part 20... Push rivet

Claims

1. A structure for fixing a bus bar to a terminal block of a power conversion device, a bus bar holder for pressing the bus bar against the terminal block, a push rivet inserted through a hole of the bus bar holder, a receiving portion formed in the terminal block for locking the push rivet, comprising: by inserting the push rivet through the hole and locking it to the receiving portion, the bus bar is sandwiched and fixed between the terminal block and the bus bar holder A bus bar fixing structure characterized by the above.

2. The bus bar fixing structure according to claim 1, wherein the bus bar holder is made of resin.

3. A power conversion device comprising the bus bar fixing structure according to claim 1 or 2.

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