JP4398593B2 - Inverter device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inverter device, and more particularly to an inverter device suitable for a vehicle including an electric motor as a drive source.
[0002]
[Prior art]
It is known that this type of inverter device is provided between a power source and an electric motor in a vehicle including an electric motor as a drive source. The inverter device includes an inverter module including a switching element, a smoothing capacitor, and the like, and is further attached to the vehicle body in a state of including a heat sink that promotes heat dissipation of the inverter module.
[0003]
In this type of inverter device, electrical noise generated when the switching element is activated may adversely affect the operation of other electrical devices provided in the vehicle. For this reason, conventionally, a noise filter unit having a built-in capacitor is connected to the inverter module and attached to the inverter device to remove noise.
[0004]
However, when the noise filter unit is provided in the inverter device, the inverter device becomes large, and there is a disadvantage that a wider mounting space is required in the vehicle body. Moreover, since a noise filter unit is separately required, there is a disadvantage that the cost increases.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a low-cost and compact inverter device that eliminates such disadvantages and can obtain a noise filter function with a very simple structure.
[0006]
[Means for Solving the Problems]
In order to achieve such an object, the first invention includes an inverter module having a built-in switching element, a smoothing capacitor having electrodes connected to a pair of power input terminals of the inverter module, the inverter module, and the smoothing capacitor. In the inverter device in which the smoothing capacitor is an electrolytic capacitor and the main body case is set to a negative potential , the smoothing capacitor is externally attached to the main body case of the smoothing capacitor. A holder fixedly held on the base plate is provided, and a grounded conductive portion facing the main body case of the smoothing capacitor and an insulating portion interposed between the conductive portion and the main body case of the smoothing capacitor are provided on the holder. It is characterized by that.
[0007]
In the inverter device according to the first aspect of the present invention, a base plate that integrally supports the inverter module and the smoothing capacitor is provided, and the smoothing capacitor is fixedly held on the base plate via a holder. The holder is provided with a grounded conductive portion facing the main body case of the smoothing capacitor via an insulating portion. Since the smoothing capacitor is an electrolytic capacitor whose main body case has a negative potential, a capacitor structure is formed by the main body case of the smoothing capacitor and the insulating and conductive portions of the holder. Since the capacitor structure can provide a noise filter function that prevents the propagation of noise, the structure can be simplified and a low-cost and compact inverter device can be configured.
[0008]
According to a second aspect of the invention, an inverter module having a built-in switching element, a pair of metal bus plates connected to each of a pair of power input terminals of the inverter module, and each electrode connected to each bus plate. and a smoothing capacitor, and a base plate for supporting integrally the inverter module and the smoothing capacitor, the smoothing capacitor in the inverter device that main body case is a negative potential a electrolytic capacitor, between the two bus plates, a pair In addition, a grounded conductive shield plate is provided between the two insulation sheets, and the base plate is externally mounted on the body case of the smoothing capacitor, and the smoothing capacitor is fixedly held on the base plate. A holder is provided, and the smoothing condenser is attached to the holder. Characterized by providing the insulating portion interposed between a conductive part which is grounded to face the body case, the main body case of the conductive portion and a smoothing capacitor.
[0009]
In the inverter device according to the second aspect of the present invention, a pair of bus plates is provided between the inverter module and the smoothing capacitor to eliminate inconvenience of cable wiring work and prevent erroneous wiring. The both bus plates have a capacitor structure formed by a pair of insulating sheets and a grounded conductive shield plate between the two insulating sheets. Since the capacitor structure formed by both bus plates functions as a noise filter, there is no need to provide a separate noise filter unit as in the past, and a low-cost and compact inverter device that prevents noise propagation is extremely simple in structure. can do.
Thereby, while the said bus plate provides a 1st noise filter function, the said holder can provide a 2nd noise filter function, and thereby it can prevent noise propagation more reliably.
[0011]
In the second invention , when the inverter device is provided in a vehicle including an electric motor as a drive source, the shield plate is preferably electrically connected to a body of the vehicle . In the above invention or the second invention, it is preferable that the conductive portion of the holder is electrically connected to the body of the vehicle. Thereby, noise generated from the inverter module can be further reduced, and the influence of noise on various electric devices provided in the vehicle can be surely reduced.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. 1 is a plan view showing the inverter device of the present embodiment, FIG. 2 is a view taken along the line II in FIG. 1, FIG. 3 is a circuit diagram of the inverter device of the present embodiment, and FIG. 4 is an exploded perspective view showing the configuration of the bus plate. FIG. 5 is a diagram showing the noise of the inverter device, FIG. 6 is an explanatory longitudinal sectional view showing the structure of the holder, and FIG. 7 is an explanatory longitudinal sectional view showing another aspect of the holder.
[0013]
The inverter device 1 of the present embodiment is mounted inside a vehicle such as an electric vehicle (not shown), and includes an inverter module 3 and a smoothing capacitor 4 on a metal base plate 2 as shown in FIGS. ing. As shown in FIG. 2, the base plate 2 includes a heat sink 5 composed of a plurality of fins on the lower surface side corresponding to the inverter module 3. The base plate 2 is fixed in a state of being electrically connected to the vehicle body 7 via a metal screw member 6.
[0014]
As shown in FIG. 3, the inverter device 1 of the present embodiment is connected between a battery power supply 8 and a motor 9, and the inverter module 3 includes a plurality of switching elements 10 and a plurality of diodes 11. It is said that. As shown in FIGS. 1 and 2, the smoothing capacitor 4 has positive and negative electrodes 12 and 13 connected to power supply input terminals 16 and 17 of the inverter module 3 through a pair of bus plates 14 and 15. . The smoothing capacitor 4 includes a main body case 18 made of aluminum, and the main body case 18 is fixedly held on the base plate 2 via a holder 19. The smoothing capacitor 4 is an electrolytic capacitor, and its body case 18 has a negative potential.
[0015]
As shown in FIGS. 1 and 4, the bus plates 14 and 15 are connected to the first bus plate 14 having the first connection portion 20 connected to the positive power input terminal 16 of the inverter module 3 and the negative polarity of the inverter module 3. The second bus plate 15 includes a second connection portion 21 connected to the side power input terminal 17. Furthermore, a pair of insulating sheets 23 and 24 are provided between the first bus plate 14 and the second bus plate 15 with a metal plate-like conductive shield plate 22 in an overlapping manner. As shown in FIG. 2, the shield plate 22 is connected to the base plate 2 via the lead wire 25 via the screw member 6. As a result, as shown in FIG. 3, the bus plates 14 and 15 form a capacitor structure, and a function as a so-called Y-type noise filter that bypasses noise generated from the switching element 10 of the inverter module 3 can be obtained.
[0016]
Here, the effect as a noise filter by the bus plates 14 and 15 of this embodiment is shown in FIG. In FIG. 5, the noise from the inverter module 3 when the bus plates 14 and 15 of this embodiment are provided is indicated by a line a in FIG. Note that line b in FIG. 5 indicates noise of the inverter device according to the conventional configuration in which the shield plate 22 is not provided between the first bus plate 14 and the second bus plate 15. As shown in FIG. 5, the inverter device 1 provided with the bus plates 14 and 15 of the present embodiment is provided with an extremely high noise filter function as compared with the conventional inverter device.
[0017]
2, the holder 19 receives the lower side of the main body case 18 of the smoothing capacitor 4 and the main body case 18 of the smoothing capacitor 4 from above. The pressing member 27 includes a pressing member 27 and a screw member 28 that holds the body case 18 of the smoothing capacitor 4 between the pressing member 27 and the receiving member 26 by connecting the pressing member 27 to the receiving member 26.
[0018]
As shown in FIG. 6, the holder 19 has a conductive portion formed by the pressing member 27 and the receiving member 26 being formed of a metal block, and the holding capacitor 27 and the receiving member 26 are smooth capacitors. Insulating portions are formed by insulating sheets 29 and 30 provided on the surface facing the four main body cases 18. Further, as shown in FIG. 2, the pressing member 27 is grounded to the base plate 2 via a screw member 6 by a lead wire 31. As a result, as shown in FIG. 3, a capacitor structure is formed by the holder 19 and the body case 18 of the smoothing capacitor 4, and an effect as a noise filter that bypasses the noise generated from the switching element 10 of the inverter module 3 is obtained. Can do.
[0019]
In the holder 19 shown in this embodiment, as shown in FIG. 6, the receiving member 26 and the holding member 27 are formed by metal blocks to form a conductive portion, and the insulating sheet 29 is provided on the body case 18 side of the smoothing capacitor 4. , 30 are provided as insulating portions, but the holder in the present invention is not limited to this configuration. That is, if the structure of another holder is given, as shown in FIG. 7, the receiving member 26 and the pressing member 27 are made of an insulating material such as synthetic resin. In this case, the base plate 2 is used as a conductive portion on the receiving member 26 side, and conductor layers 33 and 34 plated with a metal plate or metal are provided on the surface facing the smoothing capacitor 4 to provide lead wires 35 and 36. A noise filter function can be added by providing a conductive portion grounded to the base plate 2 via the base plate 2 and providing insulating sheets 29 and 30 between the smoothing capacitor 4 and the main body case 18 to form an insulating portion. Further, although not shown, by covering the body case 18 of the smoothing capacitor 4 with a synthetic resin film or the like, the covering member such as the synthetic resin film becomes an insulating portion, and the receiving member 26 and the pressing member 27 are formed by a metal block. If the conductive portion is used, a noise filter function can be added.
[0021]
Moreover, in this invention, it does not prevent providing the noise filter unit which is not illustrated in the structure of this embodiment separately. In this case, since the noise filter function is added to the bus plates 14 and 15 and the holder 19, the noise filter unit can be made inexpensive and small by reducing the capacitance of the capacitor constituting the noise filter unit, for example. The increase in the cost of the inverter device 1 can be reduced and the noise filter effect can be increased.
[0022]
In addition, as a specific material of the shield plate described above, if a copper plate (copper foil) or aluminum plate (aluminum foil) with low electrical resistance is used and a material with low dielectric loss is selected for the insulating sheet, the noise reduction effect is high. . Furthermore, when installing the shield plate and the grounding terminal of the conductive part, it is preferable to make the connection wiring as short as possible for noise countermeasures, and noise propagation can be suppressed by installing it on the base plate or the heat sink.
[Brief description of the drawings]
FIG. 1 is a plan view showing an inverter device according to an embodiment of the present invention.
FIG. 2 is an II arrow view of FIG.
FIG. 3 is a circuit configuration diagram of the inverter device of the present embodiment.
FIG. 4 is an explanatory perspective view showing an exploded configuration of a bus plate.
FIG. 5 is a diagram showing noise of the inverter device.
FIG. 6 is an explanatory longitudinal sectional view showing a configuration of a holder.
FIG. 7 is an explanatory longitudinal sectional view showing another aspect of the holder.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inverter apparatus, 3 ... Inverter module, 4 ... Smoothing capacitor, 7 ... Vehicle body, 10 ... Switching element, 12, 13 ... Electrode, 14, 15 ... Bus plate, 16, 17 ... Power supply input terminal, 18 ... Main body case , 19 ... Holder, 22 ... Shield plate, 23, 24 ... Insulating sheet.

Claims (4)

An inverter module having a built-in switching element; a smoothing capacitor in which each electrode is connected to a pair of power input terminals of the inverter module; and a base plate that integrally supports the inverter module and the smoothing capacitor; In an inverter device that is an electrolytic capacitor and whose main body case has a negative potential ,
The base plate is provided with a holder for fixing and holding the smoothing capacitor on the base plate by covering the body case of the smoothing capacitor,
An inverter device , wherein the holder is provided with a grounded conductive portion facing the main body case of the smoothing capacitor, and an insulating portion interposed between the conductive portion and the main body case of the smoothing capacitor . Inverter module with built-in switching element, a pair of metal bus plates connected to each of a pair of power input terminals of the inverter module, a smoothing capacitor with each electrode connected to each bus plate , and the inverter module And an inverter device in which the smoothing capacitor is an electrolytic capacitor and its main body case has a negative potential.
A pair of insulating sheets are provided between both bus plates, and a grounded conductive shield plate is provided between both insulating sheets.
The base plate is provided with a holder for fixing and holding the smoothing capacitor on the base plate by covering the body case of the smoothing capacitor,
An inverter device, wherein the holder is provided with a grounded conductive portion facing the main body case of the smoothing capacitor, and an insulating portion interposed between the conductive portion and the main body case of the smoothing capacitor. The inverter device is provided in a vehicle including an electric motor as a drive source,
The inverter device according to claim 2, wherein the shield plate is electrically connected to a body of the vehicle . The inverter device is provided in a vehicle including an electric motor as a drive source,
The inverter device according to claim 1, wherein the conductive portion of the holder is electrically connected to a body of the vehicle .

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