JPS64669Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a cased pneumatic switch.

In a case-enclosed pneumatic switch in which the movable electrode is opened and closed via a drive lever provided for each phase with respect to a connecting drive shaft that is common to each phase provided in the case, the movable electrode Issues include the insulation distance to ground and the insulation distance of the fixed electrode to the drive lever. Therefore, in order to make the switch smaller and lighter, it is necessary to ensure a sufficient insulation distance between them and to make the space between them as narrow as possible.

However, conventionally, such a measure has not been taken between the fixed electrode and the drive lever because there is an arc extinguishing chamber surrounding the fixed electrode. However, fixing fittings such as screws are provided at the bottom of the arc extinguishing chamber to attach it to the fixed electrode, and the fixed electrode inside the arc extinguishing chamber has a mounting conductor attached to the inner end of the bushing that penetrates the case. Since the connection is made through the arc chamber, it is necessary to arrange the connection drive shaft and the drive lever at a position away from the fixed electrode in order to ensure sufficient pressure resistance in the entire fixed electrode section. Therefore, in order to make the switch smaller and lighter by arranging the drive lever etc. near the fixed electrode, it is necessary to further improve the withstand voltage in the fixed electrode part.

On the other hand, the movable electrode moves away from the fixed electrode and approaches the case when the circuit is opened, so if the movable electrode is used as a power source, it will not be possible to insulate it unless a sufficient insulation distance to the ground is secured. Become. Therefore, it is desired to improve the insulation between the movable electrode and the ground in the open state in order to make the switch smaller and lighter.

This idea was made based on the above request, and there is a space between the bushing on the fixed electrode side and the bottom of the arc extinguishing chamber in the case and the drive lever for opening and closing the movable electrode. An insulating barrier is provided between the movable electrode and the case, and an insulating barrier is provided between the movable electrode and the case to surround the movable electrode when the circuit is opened. It is an object of the present invention to provide a case-encased pneumatic switch which allows electrodes to be brought close to the case and which reduces the size and weight of the switch.

An embodiment of the present invention will be described below with reference to the drawings. The case 1 of this switch comprises a main case 2 and a bottom box 3 which is closely attached to the bottom of the main case 2 via a packing.
The main body case 1 is provided on its upper surface with a bracket 4.
The circuit board is provided with a mounting bracket 5 and an earth terminal 6 for mounting the circuit board to the inverter, and bushings 7, 8 are fixedly provided in an airtight manner through each side of the circuit board for each phase. Mounting conductors 11, 12 are fixedly provided at the inner ends of the bushings 7, 8 and are connected to lead wires 9, 10 led out from the outer ends of the bushings 7, 8.

A connecting conductor 13 is bolted to one of the mounting conductors 11, a fixed electrode 14 is caulked to the conductor 13, and an arc extinguishing chamber 15 is attached with screws so as to surround the fixed electrode 14. The arc extinguishing room 1
At the bottom of 5 (appearing upward on the drawing) there is a third
As shown in the figure, an insulating barrier 16 having a horizontal U-shape in plan section is fitted, and a partition plate portion 16a at the center thereof is fitted.
It is screwed together with the arc extinguishing chamber 15 to the connecting conductor 13.

A movable electrode 17 is rotatably bolted to the other mounting conductor 12 and corresponds to the fixed electrode 14 so as to be able to come into contact with and be separated from the fixed electrode 14. At the center of the movable electrode 17 is a lower end of a connecting link 18 made of an insulating material. The part is rotatably attached to the shaft. The upper end of the connection link 18 is rotatably attached to the tip of a drive lever 20 whose base end is fixed to a connection drive shaft 19 common to each phase.

The main body case 2 and the drive lever 20 are isolated from live parts such as the connecting conductor 13 by the upper half of the insulating barrier 16, and the drive lever 20 and the fixed and movable electrode parts are connected between each phase and between the phases on both sides. It is isolated by four interphase insulation barriers 21 which are riveted to the main body case 2 so as to be located laterally. Further, a connecting lever L is fixed to the connecting drive shaft 19, and a connecting pin P protruding from the lever L is linked to an operating handle 22 outside the case 1 via an operating mechanism.

Ventilation grooves 23 are provided on the circumferential side of the four corners of the lower surface of the bottom box 3.
A vent plug 23 with a concave portion a for venting gas in the event of a short circuit is inserted so as to be able to pop out from below via a rubber cushioning gasket 24, and a vent plug 23 is inserted into one side of the inner bottom surface as shown in FIG. Engagement hole 2 for each phase
An angular engaging fitting 26 with a transparent numeral 5 is fixed by welding, and a fixing fitting 27 is welded to the other side of the bottom surface of the bottom box 3 so as to correspond to the engaging fitting 26. As shown by the chain line in FIG. 1, the ground insulating barrier 28 that accommodates and surrounds the movable electrode 17 when the circuit is open forms an open box shape as shown in FIG. A pair of leg portions 29 are protruded to abut on the bottom surface, and an engaging protrusion 30 that fits into the engaging hole 25 of the engaging metal fitting 26 is formed on one side thereof, and the engaging projection 30 that fits into the engaging hole 25 of the engaging metal fitting 26 is formed on the other side. A fixing tongue piece 31 having a mounting hole 31a is formed so as to be riveted to the fixing metal fitting 27. Therefore, the ground-to-ground barrier 28 can be fixed to the bottom box 3 by fitting the engagement protrusion 30 into the engagement hole 25 and then riveting the fixing tongue piece 31 to the fixing metal fitting 27. Ru.

Now, the case-filled pneumatic switch configured as described above is formed so that the insulation distance between the phases and between the opening/closing operation mechanisms on both sides or the case is long due to the interphase insulation barrier 21. Even if the space is narrow, sufficient insulation distance can be obtained. or,
By opening and closing the operating handle 22, the connecting drive shaft 19 is rotated via the opening/closing operation mechanism, and the movable electrode 17 of each phase is rotated via the drive lever 20 of each phase.
When the circuits are opened and closed all at once, the movable electrode 17 comes very close to the bottom box 3 as shown by the chain line in FIG. Therefore, a sufficient insulation distance to the ground can be obtained.

On the other hand, the drive lever 20 approaches the fixed electrode portion (fixed electrode 14, connecting conductor 13, etc.) both when the circuit is open (indicated by the chain line in FIG. 1) and when the circuit is closed (indicated by the solid line in the figure). However, the connecting conductor 13
The insulation barrier 16 provides a sufficient insulation distance for the screws and the like connected thereto. or,
The insulating barrier 16 includes a fixed electrode part and a main body case 2.
A sufficient insulation distance between the inner and upper surfaces is ensured.

As mentioned above, this invention provides an insulating barrier between the bushing on the fixed electrode side and the bottom of the arc extinguishing chamber and the drive lever that opens and closes the movable electrode.
In addition, by disposing an insulating barrier between the movable electrode and the case to surround the movable electrode when the circuit is opened,
Since the drive lever can be brought close to the fixed electrode and the switch can be made smaller and lighter, it is a practically preferable idea as a cased pneumatic switch.

Note that this invention is not limited to the above-mentioned embodiments, and can be arbitrarily modified without departing from the spirit of this invention, such as forming an upper plate portion as a lid on the upper surface of the insulating barrier 16.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing an embodiment of this invention.
FIG. 2 is a side sectional view of the main parts, FIG. 3 is an enlarged perspective view showing the insulation barrier, and FIG. 4 is an enlarged exploded perspective view showing the ground insulation barrier and the engagement fittings. Case...1, Bushing...7, 8, Lead wire...9, 10, Mounting conductor...11, 12, Connecting conductor...13, Fixed electrode...14, Arc extinguishing chamber...1
5. Insulating barrier...16, Movable electrode...17, Connecting drive shaft...19, Drive lever...20, Ground insulating barrier...28.

Claims (1)

[Scope of utility model registration request] In a case-enclosed pneumatic switch in which a movable electrode is opened and closed via a drive lever provided for each phase with respect to a connecting drive shaft that is common to each phase provided in the case, bushing and arc extinguishing on the fixed electrode side are used. An insulating barrier is disposed between the bottom of the chamber and the drive lever, and an insulating barrier is disposed between the movable electrode and the case to surround the movable electrode when the circuit is opened. Middle switch.