JPH09205778A - Inverter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accomplish the reduction of generated noise by the decrease of inductance, the realization of a snubberless device, the downsizing of an inverter device by it, the reduction of number of parts, and the curtailment of dispersion of the dispersion of inductance caused by the distance between a switching element and a electrolytic capacitor. SOLUTION: A screw 136 Is one for connecting the first electrode bus metallic plate 113, an electrolytic capacitor 112, and a switching element 111 with one another, and a screw 137 connects the second electrode bus metallic plate 114, the electrolytic capacitor 112, and the switching element 111 with one another. Moreover, 116 is a heat sink for the switching element 111. This is of such wiring structure that an insulating plate 115 is put between the first electrode bus metallic plate 113 and the second electrode bus metallic plate 114, and that a pair of tubular metallic plates 113 are opposed to them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device, and more particularly to an inverter device suitable for reducing a wiring inductance as compared with a conventional one.

[0002]

2. Description of the Related Art Conventionally, in an inverter device in which a switching element and an electrolytic capacitor are connected by a bus bar, the bus bar has a parallel plate shape. This is to reduce the current density and the inductance by making the bus bars flat.

[0003]

In the prior art, in an inverter handling a large current, the volume of the electrolytic capacitor portion becomes huge, so that the distance from the electrolytic capacitor to the switching element becomes long and the inductance increases. Present demands are to make the inverter device snubberless and to reduce the generated noise. In order to achieve snubberlessness, it is necessary to eliminate the wiring inductance between the switching element and the electrolytic capacitor, but in the conventional example, the wiring inductance cannot be reduced by the amount required for the snubberlessness.

It is an object of the present invention to reduce generated noise and realize snubberlessness by reducing the inductance made possible by making a conductor for connecting a switching element and an electrolytic capacitor into a cylindrical shape, and thereby miniaturizing an inverter device. And reducing the number of parts and reducing the variation in inductance due to the distance between the switching element and electrolytic capacitor.

[0005]

In order to achieve the above object, the present invention is an inverter device for connecting a switching element and an electrolytic capacitor with a bus bar, one of which is characterized in that the bus bar has a tubular shape. And Or
The electrolytic capacitor is arranged in the bus bar.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an inverter device according to the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view of the inverter device of this embodiment. However, some of the drawings are cut for the sake of explanation. 111 is a switching element for one phase, and 112 is an electrolytic capacitor. Reference numeral 113 denotes a first-pole busbar metal plate formed of at least one sheet that connects the first pole (for example, positive electrode) of the switching element 111 and the first pole of the electrolytic capacitor 112, and has a tubular shape. Reference numeral 114 denotes a second-pole busbar metal plate formed by at least one sheet that connects the second pole (for example, the negative electrode) of the switching element 111 and the second pole of the electrolytic capacitor 112, and the first-pole busbar metal plate 113.
Like, the shape is tubular. Reference numeral 115 is an insulating plate that is sandwiched between the first pole busbar metal plate 113 and the second pole busbar metal plate 114 to insulate the first pole and the second pole. In addition, 1
The screw 36 connects the first pole busbar metal plate 113 to the electrolytic capacitor 112 and the switching element 111, and the screw 137 connects the second pole busbar metal plate 114 to the electrolytic capacitor 112 and the switching element 111. Reference numeral 116 is a heating element for the switching element 111. As described above, the insulating structure 115 is sandwiched between the first pole busbar metal plate 113 and the second pole busbar metal plate 114 so that the pair of cylindrical metal plates 114 face each other. By reducing the inductance and increasing the surface area, the heat dissipation effect is also increased.

FIG. 2 shows a perspective view of the inverter device of this embodiment. However, some of the drawings are cut for the sake of explanation. Reference numeral 113 denotes a first-pole busbar metal plate composed of at least one sheet that connects the first pole (for example, positive electrode) of the switching element 111 and the first pole of the electrolytic capacitor 112, and particularly surrounds the electrolytic capacitor on all sides. 114 is the second pole (for example, negative pole) of the switching element 111 and the electrolytic capacitor 1.
It is a second pole busbar metal plate composed of at least one sheet for connecting the second pole of 12 and, like the first pole busbar metal plate 113, particularly surrounds the electrolytic capacitor on all sides. Reference numeral 115 is an insulating plate that is sandwiched between the first pole busbar metal plate 113 and the second pole busbar metal plate 114 to insulate the first pole and the second pole.
The screw 136 connects the first pole busbar metal plate 113 to the electrolytic capacitor 112 and the switching element 111, and the screw 137 connects the second pole busbar metal plate 114 to the electrolytic capacitor 112 and the switching element 111. . Further, 127 is an insulating support for the heat sink 116 for the inverter device and the bus bar. that's all,
By forming an insulating plate between the first pole busbar metal plate and the second pole busbar metal plate so that a pair of metal plates are opposed to each other, the inductance is reduced and the surface area is reduced as compared with the one disclosed in JP-A-3-285570. The heat dissipation effect is also increased by earning.

FIG. 3 shows a method of connecting a metal plate and an electrolytic capacitor in the inverter device of this embodiment. The positive electrode side metal plate 131 has two kinds of holes, large and small, for connection with the electrolytic capacitor 134. Small holes are electrolytic capacitors 13
4 is a hole for connection with the positive electrode, and a large hole is for avoiding contact with the negative electrode terminal of the electrolytic capacitor 134. Similarly, the negative electrode side metal plate 132 has two kinds of holes, large and small, for connection with the electrolytic capacitor 134. The small holes are for connecting the negative electrode of the electrolytic capacitor 134, and the large holes are for avoiding contact with the positive electrode terminal of the electrolytic capacitor 134. Since the negative electrode side metal plate 132 is attached from above the insulating plate and the positive electrode side metal plate, a conductive spacer 135 is used for reinforcement. Incidentally, 136 is a positive-side screw and 137 is a negative-side screw.

As described above, by making the buzz bar have a tubular shape, the self-inductances of the buzz bars are canceled out so that the buzz bar is close to 0. Therefore, the inductance can be reduced and the noise generated by the inductance can be reduced accordingly. Further, it realizes snubberlessness, which leads to downsizing of the inverter device and reduction of the number of parts. In addition, the variation in inductance due to the distance between the switching element and the electrolytic capacitor is reduced.

In this embodiment, a normal tubular material is used, but a material with holes may be used to improve the heat radiation ability.

[0012]

According to the present invention, the parallel conductor has a tubular shape, which enables reduction of inductance.

[Brief description of drawings]

FIG. 1 is a perspective view of an inverter device according to the present invention.

FIG. 2 is a perspective view of an inverter device according to the present invention.

FIG. 3 is an explanatory diagram of a connection structure between the metal plate and the electrolytic capacitor in FIGS. 1 and 2.

[Explanation of symbols]

111 ... Switching element, 112 ... Electrolytic capacitor,
Reference numeral 113 ... Negative electrode side tubular metal plate, 114 ... Positive electrode side tubular metal plate, 115 ... Insulating plate, 116 ... Heat sink, 136 ...
Positive screw, 137 ... Negative screw.

Claims (2)

[Claims] 1. An inverter device in which a switching element and an electrolytic capacitor are connected by a bus bar, wherein the bus bar has a tubular shape. 2. The inverter device according to claim 1, wherein the electrolytic capacitor is arranged in the bus bar.