JPS6235249Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cylindrical cut-out switch used in underground distribution towers.

In recent years, transformers have become larger due to increased capacity,
Overhead power distribution systems are being replaced by underground wiring and above-ground facility systems for the purpose of increasing cable diameter, aesthetics, and disaster prevention.

However, in contrast to the cylindrical cut-out switches used in distribution towers installed on the ground, there are problems with safety and size when using the release-type fuses used in pole-mounted facilities as they are. . In other words, release type fuses are dangerous because they release high temperature gas when blown, and release type fuses are larger than current limiting fuses with the same short circuit capacity, so it is necessary to incorporate this release type fuse into the interior. As cylindrical cut-out switches have become larger, the distribution towers in which they are housed have had to become larger.

In order to solve this problem, it is better to use a current limiting fuse, but this also has the following problems. That is, in order to attach a current limiting fuse to a cylindrical cut-out switch, it is necessary to provide electrodes and an arc extinguishing device for opening and closing the load, or a connecting portion for connecting an operating rod when attaching and detaching the fuse. For this reason, a special current limiting fuse must be manufactured, which poses problems in terms of cost and compatibility. Furthermore, if the current limiting fuse is directly connected to and removed from the cylindrical cut-out switch, physical force is applied to the current limiting fuse, which may cause damage.

Furthermore, when a current limiting fuse is blown, an indicator member (protruding member) protrudes from one terminal portion, and this protruding indicator member opens the seal of the cylindrical cut-out switch to indicate that the fuse has blown. Therefore, it is necessary to place the protruding position of the display member close to the seal plug. Therefore, there is a problem in that one of the terminals faces the opening of the bushing, making it impossible to ensure a sufficient insulation distance from the ground.

The object of the present invention is to provide a cylindrical cut-out switch which can be fitted with a general-purpose current limiting fuse link and which can solve the above-mentioned problems.

An embodiment embodying the present invention will be described below with reference to the drawings. First, the distribution tower in which the cylindrical cut-out switch of the present invention is used will be explained with reference to FIG. 1. In the figure, 1 is the casing of the distribution tower installed on the ground. , 4. Reference numeral 5 denotes a cylindrical cut-out switch of the present invention that is fixed through the partition wall 2, and a power supply side lead wire 7 is connected to a connection terminal of an opening side electrode to be described later through a bushing 6 with a disconnecting section. Transformer 8 fixed in rear chamber 4
A transformer side lead wire 9 connected to the primary side of the transformer is also connected to a top side electrode which will be described later. 10 is insulating oil.

Next, switch the cylindrical cutout switch 5 to the second position.
To explain the drawings in detail, 11 is a cylindrical bushing with one end open, and a seal plug 12 is attached to the shaft 13 so as to be openable and closable.

Reference numeral 14 denotes a fuse case installed in the bushing 11, and is constructed by removably screwing first and second electrodes 16 and 17 onto both ends of a cylindrical insulating tube 15, respectively. . Reference numeral 18 is a rod-shaped insertion contact portion formed protruding from the first electrode 16, and an arc extinguishing rod 19 is fixed to the tip. A current limiting fuse link 20 is housed in the fuse case 14, and first and second terminals 21 and 22 at both ends are connected to the first and second electrodes 16 and 17, respectively. Two electrodes 1
It is designed to bridge 6 and 17. Reference numeral 23 is a projecting member built into the second terminal 22 side of the current limiting fuse link 20, and is designed to project outward when the fuse element is blown.
24 is the first electrode 16 and the current limiting fuse link 2;
0 and the first terminal 21 of the current limiting fuse link 2 due to its spring action.
0 in the fuse case 14,
First and second electrodes 16, 17 and first and second terminals 2
1 and 22 are ensured.

Reference numeral 25 denotes a top side fixed electrode fixed to the top side of the bushing 11 so as to pass through the inside and outside thereof, and the transformer side lead wire 9 is connected to the outside side, and the contactor 26 on the inside side is connected to the top side fixed electrode 25. The fitting contact portion 18 of the fuse case 14 is inserted into the fuse case so that it can be moved in and out. Reference numeral 27 denotes a cushioning material provided at the inner end of the contactor 26, and is adapted to perform a cushioning action between the tip of the insertion contact portion 18 and the inner end of the contactor 26. Reference numeral 28 denotes an arc extinguishing tube fixed to the outer periphery of the base end of the contact 26, which cooperates with the arc extinguishing rod 19 to extinguish the narrow gap when the insertion contact portion 18 is separated from the contact 26. It's becoming like that.

Reference numeral 29 denotes an opening-side fixed electrode fixed to the inner circumferential surface of the bushing 11 at a position slightly inward from the opening of the bushing 11, into which the second electrode 17 of the fuse case 14 is removably inserted. At the same time, the power supply side lead wire 7 is connected to the bushing 11 via a connecting terminal 30 which is diagonally fixed through the bushing 11.

Reference numeral 31 denotes a connecting portion protruding from the outer surface of the second electrode 17, to which an operating rod (not shown) for attaching and detaching the fuse case 14 to and from the bushing 11 is connected. Reference numeral 32 is a guide tube made of an insulating material screwed onto the inner periphery of the connecting portion 31, and one end thereof extends toward the opening side of the bushing 11. Reference numeral 33 denotes an indicator rod that is inserted into the guide tube 32 so as to be retractable.It is normally recessed into the guide tube 32 by the urging force of the spring 34, and when the protruding member 23 is blown by the current limiting fuse link 20. It is projected outward by the protruding action, and this protrusion opens the seal plug 12 and indicates a melt cut. The extension portion of the guide tube 32 has a guiding function when connecting the operating rod to the connecting portion and a function of preventing rattling after the connecting portion.

Now, connect the operating rod to the connection part 31 of the second electrode 17, take out the fuse case 14 from the bushing 11, remove the first electrode 16 or the second electrode 17, and connect the ordinary general-purpose current-limiting fuse link 20 to the insulating tube 15.
If the inserted first electrode 16 or second electrode 17 is screwed together, the first electrode 16 and the second electrode 1 are connected by the inserted current limiting fuse link 20.
7 is bridged. After that, connect the operating rod again to the connecting part 3.
1, the fuse case 14 is mounted in the bushing 11, and the first and second electrodes 16, 17 are inserted into the top side electrode 25 and the opening side electrode 29, respectively. A guide tube 32 is equipped with a coil spring 34 and an indicator rod 33 inside.
If the guide tube 32 is screwed onto the connecting portion 31 in advance, the guide tube 32 will also be installed inside the bushing 11 at the same time as the fuse case 14 is installed, so the indicator rod 33 and guide tube 32 can be reinstalled into the bushing 11 after the fuse case is installed. There is no need to wear it.

As described above, the cylindrical cut-out switch of the present invention has first and second electrodes 16 and 17 at both ends of the insulating tube 15, which correspond to the top side and opening side fixed electrodes 25 and 29 of the bushing 11 so as to be able to come into contact with and separate from them. Since at least one side is removably attached, there is a great effect that a normal general-purpose current-limiting fuse link 20 can be used.

In addition, since the present invention uses a current limiting fuse link, it is possible to not only downsize the cylindrical cut-out switch and therefore equipment such as distribution towers, but also reduce the This has the effect of eliminating the risk of gas release.

After the fuse case 14 is blown, the fuse case 14 can be taken out from the bushing 11 and the fused current-limiting fuse link 20 can be replaced with another general-purpose current-limiting fuse link 20.

By the way, if you try to use a cylindrical cut-out switch with the current-limiting fuse link exposed without using the fuse case 14, as mentioned above, the current-limiting fuse link will have an electrode for switching the load and an arc extinguishing device. , or a connecting portion, etc., must be provided, which increases the cost of the current limiting fuse link and makes it impossible to use a general purpose current limiting fuse link.

Further, in the cylindrical cut-out switch of the present invention, when the fuse blows, the seal plug 12 is opened via the indicator rod 33 made of an insulating material, so that the second electrode 17 of the fuse case 14 and the opening of the bushing 11 It is possible to provide a sufficient insulation distance between the parts and the ground, and therefore, there is also the effect of ensuring a sufficient insulation distance between the parts and the ground. After the fuse blows, use another general-purpose current limiting fuse link 20.
is stored in the case 14, but at this time the display bar 33
Since the indicator bar is recessed into the guide tube 32 by the biasing force of the coil spring 34, the display bar can be adapted to a reusable condition.

Next, another embodiment from the above embodiment will be explained with reference to FIG. 3. This embodiment is embodied in a cylindrical cut-out switch used vertically, and has a fixed electrode on the top side. A tulip-shaped electrode is used as the electrode 25, and the insertion contact portion 18 of the first electrode 16, which is inserted into contact with the top side fixed electrode 25, is cylindrical. Further, an arc extinguishing rod 36 is suspended from the inner top of the top side fixed electrode 25 via a spring 35, and the arc extinguishing rod 36 is inserted into the insertion contact portion 18. The arc extinguishing cylinder 37 is attached to the bushing 1 with a slight gap between the outer periphery of the
It is fixed to the inner peripheral surface of 1. Other configurations, functions, and effects are the same as those of the previous embodiment.

As described in detail above, the present invention has a first electrode attached to one end of the cylindrical insulating tube, which corresponds to the top side fixed electrode provided at the inner top of the bushing, and which corresponds to the load opening/closing. has a connecting part with an operating rod, and is attached to a second electrode that corresponds to the opening-side fixed electrode provided on the inner periphery of the bushing so as to be able to come into contact with and be separated from it, and is housed in the insulating cylinder. The first electrode and the second electrode can be bridged by a current-limiting fuse, and at least one of the first and second electrodes can be attached to and detached from the insulating tube in order to enable replacement of the current-limiting fuse. By attaching a display device to the connecting portion of the second electrode that responds to the protruding operation of the protruding member incorporating the current limiting fuse, a general-purpose current limiting fuse can be used, and compatibility of the fuse when blown is increased. This is an excellent idea for a cylindrical cut-out switch, as it not only allows for the reduction of the size of the bushing and therefore the equipment such as distribution towers, but also provides sufficient insulation between ground and earth. .

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a distribution tower using the cylindrical cut-out switch of the present invention, Fig. 2 is a sectional view showing a cylindrical cut-out switch embodying the present invention, and Fig. 3 is another embodiment. FIG. 3 is a partial cross-sectional view showing a cylindrical cut-out switch. Cylindrical cutout switch 5, butting 1
1, insulating cylinder 15, first electrode 16, second electrode 17,
Current limiting fuse link 20, protruding member 23, top side fixed electrode 25, opening side fixed electrode 29, connection part 3
1. Display bar 33.

Claims (1)

[Scope of utility model registration request] At one end of the cylindrical insulating tube, a first electrode is attached that can open and close the load with respect to the fixed electrode on the top side provided at the inner top of the bushing, and at the other end, a connection part with an operating rod is attached. A second electrode is attached to the fixed electrode on the opening side provided on the inner periphery of the bushing, and the second electrode is connected to the first electrode by a current limiting fuse housed in the insulating cylinder. and the second electrode, and in order to enable replacement of the current limiting fuse, at least one of the first and second electrodes is made removable from the insulating cylinder, and the connecting portion of the second electrode is made removable. A guide cylinder is screwed onto the guide cylinder, and the guide cylinder is always sunk into the guide cylinder by the biasing force of a coil spring, and when the current limiting fuse is blown, the guide cylinder is moved in response to the protruding movement of the protruding member built into the fuse. A cylindrical cut-out switch with an internal display rod that protrudes from the inside, and the protrusion of the display rod can open a seal plug that is pivoted to the bushing opening.