JPS6048085B2 - capacitor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved structure of a capacitor device mounted on an electric vehicle.

A chopper control device using semiconductors such as thyristors is used as a control device for the main motor of an electric vehicle, but since this control device controls high voltage and large current intermittently, high voltage,
A large capacity filter capacitor is used to smooth the current flowing through the overhead wires and rails.

FIG. 1 is a front view of a capacitor device mounted on an electric vehicle, and FIG. 2 is a longitudinal cross-sectional view taken along the line ■-■ in FIG. As shown in this figure, the conventional capacitor device has a plurality of capacitors 2 (seven in the figure) installed in an outer box 1,
These capacitors 2 are connected in parallel to form a large capacitor. This is, for example, a circuit voltage of 1500
V chopper control equipment uses a large capacitor with a rated voltage of 1800 VDC and a rated capacity of 460 pF (tank size 120
77E77l x 560m77l x height 400-mn) are connected in parallel to form a 460μF x 7x3220μF capacitor.

An inspection cover 1a is provided on the outer box 1 so that the capacitor can be attached and detached and inspected. The structure of this capacitor is such that two parallel conductors 5 are fixed to the outer box 1 via an insulator 9, and the parallel conductors 5 and the bushing 8 of the capacitor are connected by a conductor 4 having good flexibility.

A terminal block 3 is provided on the upper part of the outer box 1, and is connected to the parallel conductor 5 by a conductor 6. This terminal block 3 is provided to connect external wiring 7 between the capacitor device 1 and another device (not shown). Generally, a capacitor case is made of a thin iron plate (thickness of 1.6 cm or less), and is structured so that the case deforms due to the volumetric expansion or contraction of the impregnated oil filled inside.

Therefore, as shown in Figure 1, when multiple capacitors are installed side by side, a certain gap (usually 30 to 50 Tr$l) is required between adjacent capacitors, and the length dimension of the capacitor device, i.e. The horizontal dimension in Figure 1 had increased. Furthermore, the parallel conductor 5, the terminal block 3, and the connection conductor 6 are arranged above the capacitor 2, as described above.
In order to insulate these charged parts from the outer box 1 and the charged parts from each other, a predetermined space insulation distance is required, and when attaching or detaching the conductor to the bushing or attaching or detaching the external wiring 7 to the terminal block 3, a torque wrench is required. Since the height of the capacitor case cannot be increased due to the need for a space where the capacitor case can be operated with a wrench and a wrench, it is necessary to increase the thickness of the capacitor case or to increase the number of capacitors. The directional dimensions were increasing. Furthermore, the capacitor device has the disadvantage that it is heavy and the manufacturing cost increases depending on the external dimensions.

In order to eliminate these conventional drawbacks, it is conceivable to combine a plurality of capacitors into one large capacitor 2, as shown in FIGS. 3 and 4. Also the fifth
As shown in the figure, when the bushing 8 is provided on the side of the capacitor 2, the height of the capacitor case becomes larger, which makes it possible to shorten the length of the capacitor (the dimension in the left-right direction in Figure 3). It is possible to reduce the size and weight of the product. 3
The present invention aims to make the conventional capacitor device as described above smaller and lighter, thereby obtaining an inexpensive capacitor device. FIGS. 6 and 7 show an embodiment of this invention.

As is clear from this figure, the controller 3 according to the present invention. The capacitor device does not use an outer box, and one large capacitor 2 is mounted directly under the floor of the vehicle body 14. Therefore, the case of capacitor 2 is 32? ~6? A mounting bracket 24ta for fixing to the vehicle body 14 is fixed to the upper part of the case by a method such as welding. A bushing 8 is provided on the side surface of the case of the capacitor 2.
1 is attached to the side surface of the capacitor case 2 by welding, screwing, or the like. Inside the terminal box 11, a terminal block 3 for connecting an external conductor for wiring the capacitor device and other devices (not shown) is installed in the terminal box 11 or the case of the capacitor 2, and this terminal block 3 and the above-mentioned The bushing 8 is connected to the conductor 4. Furthermore, an exit hole 7a for pulling in the external conductor 7 and a cleat 13 for fixing the conductor are provided in the upper part of the terminal box 11. A cover 12 is provided on the open part of the terminal box 11, and by sealing the inside of the terminal box, rain, snow and dust are prevented from entering, and insulation deterioration is prevented. A mounting seat 15 with a female thread machined at an appropriate position is fixed to the case of the capacitor 2 by welding or the like, and a protective cover 16 is attached to the case of the capacitor 2.
is attached to the mounting seat 15 with bolts 17. As the device mounted under the floor of the vehicle is exposed to stones and dirt flying around as the vehicle runs, the protective cover 16 is installed to prevent the capacitor from being destroyed even if stones and sand fly away. It is preferable that the case and the protective cover 16 are installed with a predetermined gap between them.

In addition, if the capacitor 2 were to cause a short-circuit current to flow due to dielectric breakdown of the internal elements, it would generate abnormal heat and the case would be destroyed due to the generation of high-pressure gas. It also has the effect of preventing the scattering of. From the above, it is not very necessary for the protective cover 16 to cover the upper part of the capacitor 2, that is, the mounting surface under the floor of the vehicle.

According to the present invention, there are the following effects.

(a) Since the capacitor is attached directly to the vehicle body, the height of the capacitor case can be increased.

If the volume of the capacitor case remains the same, the length can be reduced by the increase in height, so the capacitor device can be made smaller and lighter. In conventional capacitors, the capacitor was further housed in an outer box, so the height of the capacitor had to be made significantly smaller than the height of the outer box so that the capacitor could be attached and removed from the outer box.

b) Since charged exposed parts such as bushings, terminal blocks, and conductors are stored in a sealed box provided on the side of the capacitor, there is no possibility of insulation deterioration due to rain, snow, dust, etc.

c) Since an outer box is not required, the manufacturing cost becomes low and the capacitor device becomes lightweight.

(d) Since the capacitor is configured with one piece, the number of bushings is reduced compared to conventional devices, which reduces leakage accidents of impregnated oil in the capacitor, resulting in a highly reliable capacitor device.

(e) The parallel conductor 5 and connecting conductor 6 of the conventional device are no longer necessary, making wiring work easier and reducing the number of electrical connections, reducing burnout accidents caused by poor contact.

As described above, the capacitor device of the present invention has an extremely simple configuration, greatly improves the size and weight reduction required for a vehicle device, and makes it possible to manufacture a highly practical capacitor device.

In addition, in the capacitor device of this invention, since the steel plate of the capacitor case is thicker than that of conventional products, even if the internal pressure changes due to the volumetric expansion or contraction of the capacitor impregnated oil, the capacitor case will not deform. Quantity is small.

A bellows or the like may be provided at any location of the capacitor case to absorb pressure changes in the capacitor case. Furthermore, if a wire mesh or the like is used for the protective cover, the heat dissipation effect against the temperature rise due to self-heating of the capacitor will be improved.

[Brief explanation of drawings]

Figure 1 is a front view of a conventional capacitor device with the inspection cover removed, Figure 2 is a sectional view taken along line 1 and 1 in Figure 1, and Figure 3 is a front view of a conventional capacitor device with its inspection cover removed. A front view showing the removed state, Figure 4 is the same as ■- in Figure 3.
5 is a sectional view of another conventional capacitor device, FIG. 6 is a front view showing an embodiment of the present invention, and FIG. 7 is a sectional view taken along the line ■-■ in FIG. 6. It is. In the figure, 2 is a capacitor, 2a is a mounting bracket, 3 is a terminal block, 4 is a conductor, 7 is an external conductor, 8 is a bushing, 11 is a terminal box, 14 is a vehicle body, 15 is a mounting seat, 16 is a protective cover,
17 is a screw.

Claims (1)

[Scope of Claims] 1. A capacitor device comprising a bushing for electrically connecting the inside and outside of the capacitor, and a terminal block for connecting the capacitor to the outside, the bushing and the terminal block being connected by a conductor, A terminal box is provided on the side wall of the capacitor case, and the above bushing, terminal block,
and a capacitor device that houses a conductor connecting these two, and a protective cover is provided on the exposed portion of the capacitor case. 2. The capacitor device according to claim 1, wherein the protective cover is screwed to the wall surface of the capacitor. 3. The capacitor device according to claim 1 or 2, wherein a predetermined gap is provided between the capacitor case and the protective cover. 4. The capacitor device according to any one of claims 1 to 3, wherein the protective cover is made of a wire mesh or a punched metal plate.