JPS6145339B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates to cylindrical cutouts.

Purpose An object of the present invention is to provide a cylindrical cutout that can have a larger rated current capacity than conventional cylindrical cutouts, and also allows safe installation and removal of current limiting fuses.

Embodiment An embodiment embodying the present invention will be described below with reference to FIGS. 1 to 11.

First, the outline of the cylindrical cutout switch body will be explained based on FIG. 1. 1 is a cylindrical body insulator in which a small diameter hole 2 is formed from the upper end to the lower part, and an enlarged diameter part 4 is continuously formed at the lower end of the small diameter hole 2 through a stepped part 3. ing. 5
is a molded cone that is inserted through and attached to the upper end opening of the main insulator 1, and there is an upper lead wire 6 inside the molded cone.
is inserted. Reference numeral 7 denotes an upper fixed electrode connected to the inner end of the upper lead wire 6, and 8 an arc extinguishing rod suspended from the inner end via a spring 9.

Reference numeral 10 denotes a lower fixed electrode frame fitted to the enlarged diameter portion 4 so as to be locked to the stepped portion 3 of the main insulator 1, and an electrode support plate 11 is fixedly provided at the upper end thereof. A plurality of lower fixed electrodes 11a (only one is shown) are fixed to this electrode support plate 11. Reference numeral 12 denotes a molded cone attached to the lower side surface of the main insulator 1, and a lower lead wire 13 inserted through the molded cone is connected to the electrode support plate 11. Reference numeral 14 denotes an arc extinguishing cylinder inserted into the small diameter hole 2 of the main insulator 1, whose lower end is supported by the stopper 15 on the lower fixed electrode frame 10, and whose upper end is connected to the lower outer periphery of the arc extinguishing rod 8. It extends directly below the upper fixed electrode 7 so as to surround it.

Next, the current limiting fuse F will be explained based on FIGS. 1 to 11.

Reference numeral 20 denotes an insulating cylinder in which a small diameter part 21 and a large diameter part 22 are integrally formed with a tapered part 23 interposed therebetween; 24 is an upper electrode attached to the upper end opening of this small diameter part 21; A contact 25 is screwed on. A lower electrode 26 is fitted onto the outer periphery of the base of the small diameter portion 21 and is fixed with an adhesive 31, and its lower portion is in contact with the tapered portion 23.

Reference numeral 27 denotes a cylindrical insulating core inserted into the large diameter portion 22 of the insulating tube 20 along the axial direction and fixed at the center, and as shown in FIG. Protrusions 27a extending in the direction are protruded at equal angles and have a star-shaped cross section. As shown in FIG. 2, an internal electrode 28 is fixed to the upper end (left end in FIG. 3) of the insulating core 27. This internal electrode 28 is provided with locking pieces 29 that are bent downward in an L-shape from six points on the periphery corresponding to the protrusions 27a of the insulating core 27. is engaged with the protrusion 27a.
Furthermore, each locking piece 2 is attached to the peripheral edge of the internal electrode 28.
An upwardly extending engagement piece 30 is provided between the proximal end portions of the cylindrical member 9 .

The engaging piece 30 of the internal electrode 28 is pressed against the small diameter portion 21 until the upper end edge of the protrusion 27a of the insulating cylinder 20 comes into contact with the inner peripheral surface of the tapered portion 23 via the locking piece 29. is inserted into.

Reference numeral 32 shown in FIG. 2 is a silk hat-shaped intermediate electrode attached to the lower end of the insulating core 27, and is attached to the peripheral edge of a flange 33 provided at the base end and abutting the lower end of the insulating core 27. As shown in FIG. 4, a locking piece 34 is projected to be locked to each protrusion 27a of the insulating core 27. Furthermore, a locking piece 35 is formed between the locking pieces 34 and extends to the inner circumference of the large diameter portion 22 of the insulating cylinder 20.

In the intermediate electrode 32, a cylindrical bulge 36 with a bottom is provided at the center of the flange 33 and protrudes below the insulating tube 20, and an insertion hole 37 is formed through the inner bottom of the bulge 36 as shown in FIG. has been done. As shown in FIG. 2, one end of a conductive plate 38 introduced from the outside is connected to one engagement piece 35a of the intermediate electrode 32 through a notch 22a at the lower end of the large diameter portion 22.
The other end of the conductive plate 38 extends along the longitudinal direction of the outer circumference of the insulating tube 20 and is connected to the lower electrode 26 .

Reference numeral 39 shown in FIG. 2 is a display tube that is inserted into the intermediate electrode 32 and the insulating core 27 through the insertion hole 37, and is attached to the display tube. A display bar 40 that can be projected is installed inside.

A first fuse element 41 has one end connected to the upper electrode 24 of the insulating cylinder 20, and the other end passes through the small diameter portion 21 and is engaged with one engagement piece 30 of the internal electrode 28.

Note that the engagement piece 30 of the internal electrode 28 is connected to the ninth fuse element 41 after the first fuse element 41 is engaged.
It is bent 90 degrees inward as shown in the figure. 42
is a second fuse element that is wound around the outer periphery of the insulating core 27 within the large diameter portion 22, and one end is engaged with the other engaging piece 30 of the internal electrode 28, as shown in FIG. , the other end is fixed to one of the fastening pieces 35a of the intermediate electrode 32, as shown in FIG.

Note that a low-melting metal portion (not shown) covered with an arc-extinguishing tube 43 is connected to the middle of the second fuse element 42, as shown in FIG. Reference numeral 44 shown in FIG. 2 is a resistance wire inserted into the insulating core 27, one end of which is connected to the internal electrode
It is engaged with one bent engagement piece 30 of No.8.
The other end of the resistance wire 44 is inserted into the display rod 40 which is housed in a recessed state against a spring (not shown) in the display tube 39, and is inserted into the intermediate electrode 32.
It is connected to the.

That is, this current limiting fuse F is connected to the upper electrode 24.
→First fuse element 41→Internal electrode 28→
An electric path is formed in the order of the second fuse element 42 → intermediate electrode 32 → conductive plate 38 → lower electrode 26, and a shunt is formed in the order of the internal electrode 28 → resistance wire 44 → intermediate electrode 32, and the second fuse element 42 On the other hand, the resistance wire 44 is connected in parallel.

45 is the small diameter part 21 and the large diameter part 22 of the insulating cylinder 20
In addition, the insulating core 2 is filled with arc-extinguishing sand.

Reference numeral 46 denotes a protective cover made of a weather-resistant insulating material that is fitted so as to cover almost the lower half of the large diameter portion 22 of the insulating tube 20, and is fixed in a watertight manner with an adhesive. A reduced diameter portion 47 for accommodating the bulged portion 36 of the intermediate electrode 32 is formed at the center of the lower end thereof. This protective cover 46 is designed to prevent the conductive plate 38 from being exposed from the lower end of the main insulator 1 when the cylindrical cutout is attached to the main insulator 1. Reference numeral 48 denotes engagement protrusions provided at positions 180 degrees opposite each other on the outer periphery of the reduced diameter portion 47 of the protective cover 46, and these engagement protrusions can be attached to and detached from the cylindrical cut-out body insulator 1 using conventional operations. A groove (not shown) is adapted for operative engagement.

As shown in FIG. 2, a through hole 49 from which the display rod 40 of the display tube 39 projects is provided in the center of the bottom surface of the reduced diameter portion 47 of the protective cover 46, and a through hole 49 is provided at the periphery via a stepped portion 50a. A skirt portion 50 is formed that projects downward.

When fitting the current limiting fuse F to the cylindrical cut-out body insulator 1 constructed as described above, it is engaged with a conventional operating rod (not shown) from the lower end opening as shown in FIG. It is inserted into the main insulator 1, and the contact 25 at its upper end is connected to the upper fixed electrode 7.
and the arc extinguishing rod 8, and the lower electrode 26 is also held between the lower fixed electrode 11a of the electrode support plate 11. Further, the small diameter part 21 of the insulating cylinder 20 is inserted into the arc extinguishing cylinder 14, and the large diameter part 22 of the insulating cylinder 20 is inserted into the enlarged diameter part 4 of the main insulator 1, and the lower end thereof is inserted into the main insulator 1. (first
(see figure).

Now, when a large current flows, the first fuse element 41 and the second fuse element 42 melt,
When the arc transitions, the resistance wire 44 is instantly fused by the voltage applied to both ends of the resistance wire 44, and the interruption is completed. By fusing the resistance wire 44, the display tube 39
An indicator rod 40 inside projects out under the bias of a spring (not shown) to display a fusing indication. On the other hand, when a small current with low magnification flows, it is reliably interrupted by the low-melting metal part (not shown) in the arc-extinguishing tube 43 of the second fuse element 42, and similarly the display tube 3
An indicator bar 40 in 9 protrudes to display a fusing display.

The lower end of the cylindrical cutout of this embodiment configured as described above protrudes from the main insulator 1 when the current limiting fuse F is attached to the main insulator 1. The lower ends of the conductive plate 32 and the conductive plate 38 are covered with a protective cover 46, so that the installation and removal work can be performed safely. It is safe because only the protective cover 46 is exposed downward from the main insulator 1.

Furthermore, a stepped portion 5 is provided on the lower surface periphery of the protective cover 46.
Since the skirt portion 50 extends downward through the 0a, when rainwater drips, it can be drained well.

In addition, in the large diameter portion 22 of the insulating tube 20 that is fitted into the enlarged diameter portion 4 of the main insulator 1, the outer diameter of the insulating core 27 can be increased. The winding diameter of the second fuse element 42 can be increased, and the rated current capacity can therefore be further increased.

Effects As detailed above, the cylindrical cut-out of the present invention can easily increase the rated current capacity even though the main insulator is a cylindrical cut-out body insulator that uses an existing discharge type fuse. Moreover, in response to this increase in capacity, the existing configuration can be maintained without any changes to the fixed electrodes etc. built into the conventional main body insulator.

Furthermore, in the cylindrical cutout of the present invention, the current limiting fuse attached to the main body insulator utilizes the large diameter part of the lower end opening of the main body insulator, and the large diameter part of the insulating tube corresponds to the same part, The outer diameter of the insulating core arranged in the large diameter part is made large, and the winding diameter of the fuse element wound around the outer periphery of this insulating core is made large to obtain a sufficient allowable length for the short length of the insulating tube. Therefore, it can be installed in the body insulator of an existing cylindrical cut-out switch in the same way as a fuse tube using a discharge type fuse, and the rated current capacity is higher than that of a discharge type fuse. It is an excellent invention for industrial use because it can be made larger and the electrodes are not exposed when attached to or removed from the cylindrical cut-out main body insulator, making it safer.

Note that the present invention is not limited to the above-mentioned embodiments, and may be embodied in a cut-out structure in which the first fuse element and the second fuse element are directly connected or a seal plug is provided at the lower end opening of the main body insulator. Any changes may be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a cylindrical cutout switch according to the present invention, FIG. 2 is a sectional view of a current limiting fuse, FIG. 3 is a front view of an insulating core, and FIG. 5 is a sectional view taken along line A, FIG. 5 is a sectional view taken along line B-B in FIG. 3, FIG. 6 is a right side view, FIG. 7 is a left side view, and FIG. 8 is a partial cross section of the lower electrode. 9 are cross-sectional views of the internal electrodes, FIG. 10 is a cross-sectional view taken along line CC in FIG. 2, and FIG. 11 is a cross-sectional view showing the arrangement of the internal electrodes and the insulating cylinder. Insulating cylinder...20, small diameter part...21, large diameter part...
22, Tapered part...23, Upper electrode...24,
Lower electrode...26, Insulating core...27, Internal electrode...28, Intermediate electrode...32, Conductive plate...38,
1st fuse element...41, 2nd fuse element...42, resistance wire...44, protective cover...46, engaging protrusion...48, skirt part...5
0.

Claims (1)

[Claims] 1. Attach an upper electrode and an intermediate electrode to both ends of an insulating cylinder consisting of a small diameter part and a large diameter part through a tapered part, connect both electrodes to each other by a fuse element, and insert the fuse element into the large diameter part. A lower electrode electrically connected to the intermediate electrode is attached to the outer periphery of the central part of the insulating cylinder, and a large diameter part of the insulating cylinder is wound around the outer periphery of an insulating core arranged along the axial direction. A cylindrical cut-out characterized in that a current-limiting fuse having a protective cover fitted thereon so as to cover the intermediate electrode is installed in the lower end of the main body insulator.