JPS6228725Y2 - - Google Patents

Description

[Detailed description of the invention] This invention connects large zinc oxide type voltage nonlinear resistors (hereinafter simply referred to as nonlinear resistors) in series and seals them in a porcelain tube.
This relates to a surge absorber with a structure that prevents the series connection of internal non-linear resistors from shifting or causing poor contact even when subjected to an impact, and even though it has these characteristics, We propose a structure that is compact in shape and does not take up much space for installation.

Surge absorbers using such large non-linear resistors have traditionally been installed in power equipment, power cables, power facilities, etc., but because the equipment itself is large, it is difficult to determine where to install it. There were relatively few strict restrictions. Therefore, large non-linear resistors were generally stacked in series and fixed with bolts or the like, and if airtightness was required, they were generally enclosed in an iron box or the like. In such cases, the iron box has to be large due to insulation issues.

Now, as the performance of the zinc oxide surge absorber mentioned above has been gradually recognized, the types of devices that use it have become diverse, and some are even built into the devices themselves. . Furthermore, when retrofitting devices to devices, the trend toward miniaturization of the devices itself has made it no longer acceptable for surge absorbers to take up a large amount of space.

In response to these technological trends, the surge absorber's surge performance is high enough to satisfy the surge performance of power equipment, and its overall shape is small, and it can even be submerged in water when no voltage is applied. Demand for performance has become increasingly sophisticated, such as complete sealing to meet strict environmental performance requirements such as preventing changes in internal elements, and conventional surge absorber structures are increasingly unable to meet these requirements. The current situation is that

The surge absorber of the present invention has been proposed to satisfy the above-mentioned required performance, and its configuration will be explained below with reference to drawings showing one embodiment.

First, FIG. 1 is a diagram illustrating the series connection of zinc oxide type voltage nonlinear resistors. In Figure 1,
Reference numeral 1 designates a plurality of non-linear resistors, each having electrodes 2, 2' on both end faces, and a through hole 3 in the center. The plurality of non-linear resistors 1 are crimped to each other with electrode plates 4 having through holes 4' located at both ends and between them, and insulating rods 5 with threads cut at both ends passed through the through holes 3 and 4'. It is tightened from both ends with nuts 6 and 6'. The figure shows a state in which four nonlinear resistors 1 are connected in series. Here, the electrode plates 4 located at both ends are overlapped with electrode plates 7 and 7' having a smaller diameter, so that a step is formed at the portions indicated by A and A'. Protrusions 7a, 7a' that fit into the through holes 4' of the electrode plates 4 located at both ends are provided on the peripheral edges of the central holes of the electrode plates 7, 7'. This prevents the electrode plates 4 located at both ends from sliding laterally. 8 and 8' are flat washers, and 9 and 9' are spring washers. 10 is a cylinder made of metal with high conductivity such as copper,
If the inner diameter of one end is fitted into the stepped portion A' and the other end is fixed to a porcelain tube (not shown in Fig. 1), which will be described later, the series body of the nonlinear resistor 1 is fixed. It also serves as a conductor to an external connection terminal (not shown in FIG. 1), which will be described later. Reference numeral 11 denotes a coil spring whose inner diameter at one end is fitted into the stepped portion A, and whose other end is fixed to the porcelain tube, thereby crimping the series body of the non-linear resistor 1 to the metal cylinder 10. It has an effect.

FIG. 2 is a diagram illustrating one end of a porcelain tube that houses the series body of the nonlinear resistor 1 shown in FIG. 1.
Reference numeral 12 is a cylindrical porcelain tube, at the end of which holes with a slightly larger diameter are bored in order to erect a plurality of bolts 13', and bolts 13' are inserted into these holes.
After each 3' is set up, cement or adhesive resin 1
4', respectively. Reference numeral 15' denotes a disk-shaped sealing metal plate, which has through holes 1 at positions corresponding to the plurality of bolts 13' fixed to the porcelain tube 12.
6' respectively, and a bolt 1 is inserted into this through hole 16'.
3' and are fixed with nuts 17'. A groove 18 is provided in the sealing metal plate 15' at a position corresponding to the metal cylinder 10, and this groove 18 also prevents the metal cylinder 10 from being displaced in the lateral direction. A groove 19' is formed in the inner peripheral edge of the sealing metal plate 15', and an O-ring 20' is fitted into this groove 19', and the bolt 13' and nut 17' are used to seal the porcelain tube 12. When the metal plate 15' is crimped and fixed, the inside of the porcelain tube 12 is sealed. Second
In the figure, 21' and 22' are flat washers and spring washers.

FIG. 3 is a diagram illustrating the other end of the porcelain tube 12, including bolts 13, cement and adhesive resin 1.
4, sealing metal plate 15, through hole 16, nut 1
7, the groove 19, the O-ring 20, the flat washer 21, and the spring washer 22 are completely the same as those on the one end side shown in FIG. 2, so their explanation will be omitted. 11 is the coil spring explained in FIG. 1;
The upper end of this coil spring 11 is installed in a groove 23 formed in a sealing metal plate 15, and further short-circuited with a soft metal plate 24 as a conductive part.

FIG. 4 is a diagram showing the finished product assembled as described above, in which the external connection terminals 25, 25' are connected to the outer surfaces of the sealing metal plates 15, 15' by means such as welding or brazing. has been done. The rest is as explained above. Here, a through hole is provided in either one of the sealing metal plates 15, 15',
It is also possible to seal the area with a thin metal plate to make it explosion-proof.

With the configuration of the present invention as described above, size reduction can be achieved by stably connecting large non-linear resistors in series and sealing them inside the porcelain tube to ensure airtightness. In addition, a coil spring and a metal cylinder are interposed between a series connection of non-linear resistors and a sealing metal plate fixed to both ends of the porcelain tube, and the coil spring and metal cylinder are attached to the sealing metal plate. By fitting into the formed groove, it is possible to provide a surge absorber having a structure in which the series connection body of the nonlinear resistor does not become misaligned or cause poor connection even when subjected to vibrations or shocks.

Note that welding may be considered as a means of fixing the sealing metal plate to both ends of the porcelain tube, but fixing means using bolts, nuts, and O-rings as described in the above embodiment are more airtight. This is more preferable in terms of ensuring quality.

[Brief explanation of the drawing]

Fig. 1 is an exploded cross-sectional view illustrating the assembly of a non-linear resistor showing one embodiment of the surge absorber according to the present invention, and Fig. 2 is an exploded cross-sectional view illustrating one end of the same porcelain tube. Figure 3 is an exploded cross-sectional view illustrating the other end of the same porcelain tube;
The figure is a half-sectional front view showing the finished product. DESCRIPTION OF SYMBOLS 1... Zinc oxide type voltage nonlinear resistor, 2... Electrode, 3... Center through hole, 4... Electrode plate, 5... Insulating rod, 6, 6'... Nut, 7, 7'... End electrode plate, 10...Metal cylinder, 11...Coil spring,
12...Porcelain tube, 13,13'...Bolt, 1
5, 15'... Sealing metal plate, 17, 17'... Nut, 18, 23... Groove, 19, 19'... Circumferential groove, 20, 20'... O-ring, A, A' ……
Step part.

Claims (1)

[Claims for Utility Model Registration] (1) A plurality of zinc oxide type voltage nonlinear resistors having electrodes on both end faces and a through hole in the center are inserted into the central through hole with an electrode plate in between. Pass the insulating rod with threaded ends and tighten it with nuts from both ends to fix it, and overlap the electrode plates at both ends of this series connection body of non-linear resistors with electrode plates smaller in diameter than the electrode plates to eliminate the stepped portion. A sealing metal plate is fixed to both ends of the porcelain tube housing the series connection body of the non-linear resistor by an appropriate means to form a sealed structure, and the step part of the electrode plate at one end is A metal cylinder is installed between the groove formed in the one sealing metal plate, and the stepped part of the electrode plate at the other end is connected to the groove formed in the other sealing metal plate. A surge absorber with a coil spring installed in between. (2) Embed and fix bolts at both ends of the porcelain tube, tighten nuts onto the bolts to secure the sealing metal plate to both ends of the porcelain tube, and insert an O into the groove on the periphery of the sealing metal plate. The surge absorber according to claim 1, which has a sealed structure by fitting and crimping a ring. (3) The surge absorber according to claim 1 of the utility model registration claim, which is made explosion-proof by making a through hole in at least one of the sealing metal plates at both ends and sealing that part with a thin metal plate. .