JPS6412059B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field This invention relates to a cutout with a current limiting fuse.

Purpose This invention serves as both a fuse attachment/detachment adapter and a sealing plug, has a simple structure, can be manufactured at low cost, and prevents explosion of the insulating cylinder, scattering of internal components and the sealing plug, falling off, etc. The purpose is to provide cutouts that can be used safely.

Embodiment Hereinafter, the present invention will be described in detail with reference to the drawings based on an embodiment in which the present invention is embodied in a cutout with a built-in transformer.

An insulating cylinder 2 made of an insulating material such as epoxy resin is inserted through a part of the transformer case 1 and fixed with a plurality of bolts 3. An opening 2a is provided at the lower end of the insulating cylinder 2, and the inner circumferential surface of the opening 2a is tapered so as to have a larger diameter toward the bottom. A connecting terminal 4a is provided at the upper end of the insulating tube 2.
A power supply side electrode 4 having a conductive rod 4b is provided, and a load side electrode 5 having a connection terminal 5a is provided at the center.

A current limiting fuse 6 is inserted into the insulating cylinder 2 from its lower end opening 2a, and an upper electrode 7 is provided at the upper end thereof to be connected to the power supply side electrode 4 via a quick-cut arc extinguishing device to be described later. At the same time, a lower electrode 8 connected to the load-side electrode 5 is provided at the lower end. A sealing plug 9 made of an insulating material such as rubber is removably attached to the lower end of the current-limiting fuse 6 at a threaded portion 10, and the upper part of the plug 9 has a sealing plug 9 that is attached to the lower end of the current-limiting fuse 6 when the current-limiting fuse 6 is inserted into the insulating cylinder 2. Insulation cylinder 2
A tapered fitting portion 9a is formed in close contact with the inner surface of the opening 2a. Further, a latching portion 9b is provided at the lower end of the sealing plug 9 for fitting and latching an operating rod (not shown) when the current limiting fuse 6 is installed or removed. It is now possible to use an adapter for both.

Insulating tube 2 exposed outside of the transformer case 1
A conductive layer 11 is formed on the outer surface of the insulating tube 2 and the outer surface of the sealing plug 9, and a protective tube 12 is provided on the outer periphery of the insulating tube 2. A pair of latch pieces 13 are attached to the outer periphery of the lower end of the protection tube 12, and a stopper 14 is attached to the upper part of the latch pieces 13.
is provided. Support protrusions 15 are provided on the outer periphery of the sealing stopper 9 in correspondence with each of the latching pieces 13, and an operating body 16 is rotatably supported by a pin 17 at the end thereof. A clamp body 18 serving as a substantially U-shaped regulating member is rotatably attached to each operating body 16 by a pin 19, and an engaging body 20 that can engage with the locking piece 13 is provided approximately at the center of the clamp body 18. It is supported to be able to move up and down, and a stopper portion 21 that can engage with the stopper 14 is provided at the upper end.
The engaging body 20 is urged in a direction to engage with the locking piece 13 by the elastic force of the coil spring 22,
As a result, the sealing plug 9 closes to the opening 2 of the insulating cylinder 2.
It is held in close contact with a.

A striker 23 is provided at the lower end of the current limiting fuse 6.
is provided so that when the fuse element in the current limiting fuse 6 is blown, the sealing plug 9 is broken and the fuse element protrudes downward. Further, a fusing display piece 24 is provided at the lower end of the sealing plug 9, and is always held in the upper position shown by the solid line in FIG. 1 by the biasing force of a coil spring 25.
When the fuse element is blown, the striker 23
With the protruding operation, it is protruded against the coil spring 25 to the lower position shown by the chain line in FIG. 1, and the fused state is displayed.

Next, to explain the configuration of the quick-cut arc extinguishing device, the conductive rod 4b of the power supply side electrode 4 has a sliding tube 2.
6 is slidably inserted and fitted, and a conductive rod 4 is attached to its upper end.
A fixed side contactor 27 that slides on b and a spring seat 28 that also serves as a stopper are attached, and an arc extinguishing rod 29 is fixed to the lower end. A tension spring 30 is provided between the power supply side electrode 4 and the spring seat 28, and the sliding tube 26, the fixed side contact 27 and the arc extinguishing rod 2
9 is moved upward and is held in an upper position regulated by the engagement between the spring seat 28 and the fixed cylinder 31 inside the insulating cylinder 2, as shown in FIG. Further, at the lower end of the spring seat 28, a locking member 32 consisting of a plurality of locking pieces is attached to a pair of ring-shaped springs 33.
It is attached so as to be expandable in diameter, and a hook portion 32a and a tapered engagement surface 32b are formed at the lower end thereof.

On the other hand, a movable side contactor 34 having a plurality of slits is protruded and fixed to the upper electrode 7 of the current limiting fuse 6 so as to come into sliding contact with the sliding tube 26 and the arc extinguishing rod 29. Moreover, the movable side contactor 3
A support tube 35 is fixedly protruding from the upper electrode 7 of the current limiting fuse 6 so as to be located outside of the upper electrode 7 of the current limiting fuse 6, and an engagement portion 35a that engages with the hook portion 32a of the hook member 32 is provided on the outer surface of the upper end of the support tube 35. At the same time, an arc extinguishing tube 36 is provided inside the upper end. A cam cylinder 37 is attached to the lower end of the fixed cylinder 31 in the insulating cylinder 2, and a cam part 37a is formed at the lower end of the cam cylinder 37 to be able to engage with the engagement surface 32b of the locking member 32. .

The operation of the cutout constructed as described above will now be explained.

Now, in FIG. 1, a current limiting fuse 6 is inserted into an insulating tube 2, and a sealing plug 9 which also serves as an adapter is attached to the lower end of the current limiting fuse 6.
This shows a state in which the lower end opening 2a is closed. In this state, as shown in FIG.
Since the insulating tube 2 is tightly fitted into the tapered opening 2a of the insulating tube 2, the inside of the insulating tube 2 is kept airtight.

And when using this cutout,
When the internal pressure of the current-limiting fuse 6 increases due to the failure of the fuse element inside the current-limiting fuse 6, etc.
The thin wall portion 7a provided on the upper electrode 7 is torn, and the internal pressure is released upward into the insulating cylinder 2. Due to the reaction of this upward pressure release, the current limiting fuse 6 and the sealing plug 9 are moved downward against the elastic force of the coil spring 22, and as shown in FIG. When engaged with the stopper 14, the movement is restricted and the fitting portion 9a of the sealing plug 9 and the opening 2 of the insulating cylinder 2
A gap S is formed between a and a. Therefore, the pressure inside the insulating cylinder 2 is easily released to the outside through this gap S, and after the release, the current limiting fuse 6 and the sealing plug 9 are returned to the original position shown in FIG. 1 by the elastic force of the coil spring 22. Moved back.

In this embodiment, the opening 2a of the insulating cylinder 2 and the fitting part 9a of the sealing plug 9 are formed in a tapered shape, so for example, when the taper angle is θ degrees as shown in FIG. , by moving the current limiting fuse 6 and the sealing plug 9 by a distance L, d=
A gap S corresponding to L sin θ is reliably formed. Therefore,
Opening part 2a of insulating cylinder 2 and fitting part 9a of sealing plug 9
Compared to a cutout without a taper, the opening 2a of the insulating tube 2 is reliably opened by only slightly moving the sealing plug 9, preventing an explosion of the insulating tube 2, internal components, and the sealing plug. 9 from scattering, falling off, etc., and can be used safely.

When removing the current limiting fuse 6 from inside the insulating tube 2, first rotate the operating body 16 as shown by the chain line in FIG.
0 from the hooking piece 13. Next, the sealing plug 9
When an operating rod (not shown) is fitted and latched onto the hooking portion 9b of the holder and the operating rod is used to pull the sealing plug 9 and the current limiting fuse 6 downward, the movable side contact 34 and the support cylinder 35 are connected to the current limiting fuse 6. It is moved downward together with the fuse 6. At this time, since the latching portion 32a of the latching member 32 is engaged with the engaging portion 35a of the support cylinder 35, as the support cylinder 35 moves, the latching member 32,
The spring seat 28, the stationary contact 27, the sliding tube 26, and the arc extinguishing rod 29 are integrally moved downward against the biasing force of the tension spring 30.

When the engaging surface 32b of the locking member 32 engages with the cam portion 37a of the cam cylinder 37, the diameter of the locking member 32 is expanded, and the locking portion 32a is attached to the support cylinder 37.
5, and the locking member 32, spring seat 28, stationary contact 27, sliding cylinder 26, and arc extinguishing rod 29 are moved to the upper position shown in FIG. 1 by the biasing force of the tension spring 30. The direction is suddenly moved back.
Therefore, due to the cooperative action of the arc-extinguishing rod 29 at the lower end of the sliding tube 26 and the arc-extinguishing tube 36 at the upper end of the support tube 35, the load is opened by quick cutting arc extinguishing, and the current is limited from inside the insulating tube 2. The fuse 6 can be safely pulled out.

Next, another embodiment of the invention will be described with reference to FIG. This embodiment is embodied in a molded cutout that is used as a device outside the transformer, and the connection terminal 5a of the load side electrode 5 is provided protruding from the outer periphery near the lower end of the insulating tube 2. This embodiment differs from the above-described embodiment in that an elbow connector 50 is attached to the connection terminal 5a and that the protective tube 12 is attached to cover the entire outer circumference of the insulating tube 2, but in other respects. The structure and operation are the same as in the previous embodiment.

Note that the present invention is not limited to the configurations of the embodiments described above, and the configuration of each part can be arbitrarily changed without departing from the spirit of the invention.

Effects As detailed above, the cut-out of the present invention includes an insulating tube having an opening formed in a tapered shape such that the inner surface becomes larger in diameter outward, and a cutout inserted into the insulating tube through the opening. A current-limiting fuse, a sealing plug that is removably attached to the end of the current-limiting fuse and also serves as a fuse attachment/detachment adapter that closes the opening of the insulating tube, and a sealing plug that is provided in a tapered shape relative to the closing plug. , a fitting portion that is in close contact with the tapered inner surface of the opening, and when the pressure within the insulating cylinder exceeds a predetermined value and the sealing plug moves in the opening direction, restricts the movement of the sealing plug beyond a predetermined value. , and a regulating member that prevents the sealing plug from separating from the opening, the following unique effects are achieved.

(a) Compared to conventional cut-outs in which a sealing plug and a fuse attachment/detachment adapter are provided separately, there is no need to prepare a fuse attachment/detachment adapter;
The structure is simple and can be manufactured at low cost.

(b) Due to the release of pressure within the current limiting fuse, the current limiting fuse and sealing plug are moved, and a gap is formed between the fitting part of the sealing plug and the opening of the insulating tube. The pressure inside the insulating cylinder is easily released to the outside through this gap, and the sealing plug is restricted from moving beyond a predetermined level by the regulating member, so that it does not come off from the opening. Therefore, it can be used safely by preventing the insulating tube from exploding and internal components and sealing plugs from scattering or falling off.

(c) Moreover, since the sealing plug is formed in a tapered shape, the opening of the insulating cylinder can be reliably opened by only slightly moving the sealing plug, and the pressure inside the insulating cylinder can be released.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of a cutout embodying the present invention, Fig. 2 is a partial side view of the same, Fig. 3 is a partial sectional view showing a state in which the pressure inside the insulating cylinder is released, and Fig. 4 is a partial sectional view of the cutout embodying the present invention. FIG. 7 is a vertical sectional view of a cutout showing another embodiment of the invention. Insulating tube...2, opening...2a, current limiting fuse...6, sealing plug...9, fitting part...9a.

Claims (1)

[Scope of Claims] 1. An insulating tube 2 having an opening 2a whose inner surface becomes tapered to a larger diameter toward the outside, and a current-limiting fuse inserted into the insulating tube 2 from the opening 2a. 6, a sealing plug 9 which is removably attached to the end of the current limiting fuse 6 and serves as a fuse attachment/detachment adapter for closing the opening 2a of the insulating cylinder 2; a fitting portion 9a provided in the opening portion 2a and closely contacting the tapered inner surface of the opening portion 2a;
When the pressure inside the insulating tube 2 exceeds a predetermined value and the sealing plug 9 moves in the opening direction, the sealing plug 9 is prevented from moving beyond a predetermined value, and the sealing plug 9 is prevented from leaving the opening 2a. A cutout characterized by comprising a regulating member 18 that prevents.