DE2339106A1 - Pneumatically actuated cct. breaker - has nozzle-shaped moving and fixed contacts in switching chamber under high pressure - Google Patents

Abstract

The high pressure switching chamber of the gas-blast circuit breaker has an inlet and an outlet valve for permitting gas stream through the nozzle-shaped contact elements. The valve associated with the stationary contact element has at least one piston whose lower space is connected to high pressure and upper space with the fixed contact nozzle channel. Between the two spaces is at least one equalising bore with such time dependent behaviour as to permit the opening of the second valve during breaking operation, owing to the pressure drop in the nozzle channel and in the upper piston space. The second valve opening is carried out against the force of a resetting spring.

Description

BROWN, BOVER! & CIE. AKTIENGESELLSCHAFT,; _,

M ANNHElM. BROWN BOV EFtI

Mp.no. 597/73 Mannheim, July 19, 1973

PAT / Ft / M-B

Compressed air holder

The invention relates to a compressed air switch, which is switched on State of the switch room under high pressure, at least one fixed and one movable, each similar to a nozzle having formed contact piece, with two of the gases a flow from the switch room through the contact pieces outwardly permitting valves, of which the first valve is coupled to the movement of the movable contact piece.

During the development of compressed air switches, it turned out that that the extinguishing effect of the compressed gas is significantly improved when a so-called double blowing takes place. For this purpose, both the fixed contact piece and the movable contact piece are designed as a nozzle, the; Nozzle channel both each has a connection to the outside. High pressure air resides inside the cylindrical Space in which the contact pieces are located. At a Senate act the moving contact piece is removed from the fixed contact piece; the air then flows out of the cylindrical ' Space through both the nozzle channel of the fixed and through the nozzle channel of the movable contact piece to the outside one blow valve each. The blow valve assigned to the movable contact piece is opened mechanically while the blow valve assigned to the fixed contact piece is pushed open synchronously with the other blow valve via compressed air will. In other words: the two blow valves are activated by control air, i. H. with a switch-off: command by pressing the corresponding piston in the open position or blown position. ;

All blowing valves are activated separately, with a compressed air line leading from the air inlet to the second blowing valve outside the switching chamber. In the event of a switching operation, the blow valve for the movable one is activated via the supply opening

and the blow valve for the fixed contact piece is routed via the control line. This requires considerable effort

on control lines or control tubes, as these must be designed as insulating tubes. The insulating tube must use protected from condensation in dry air. This means a considerable expense.

The object of the invention is to create a compressed air switch in which the cost is significantly reduced and in which an insulating tube is no longer required.

This object is achieved according to the invention in that on the second valve assigned to the fixed contact piece at least a piston is provided, wherein the space below the piston with high pressure and the space above the piston is connected to the nozzle channel of the fixed contact piece, and that between at least one compensation hole is provided in both spaces, which allows pressure equalization within a predetermined period of time, such that the second valve at a deactivation due to the pressure drop in the nozzle channel and in the Space above the piston is opened against the force of a return spring.

The space below the piston is advantageously connected to the control room via a connecting line.

Another advantageous embodiment is that the cross section of the connecting line is dimensioned such that a

+49 98 077 017

Pressure equalization between the space below the piston and the switch room is permitted with a time delay.

In a further advantageous embodiment, the second valve is approximate cylindrical and has a radially outward pointing at the end opposite the valve seat Edge that serves as a piston.

In the event of a switch-off action, this will now affect the movable contact piece associated valve, which is also referred to as a blow valve, open; this reduces the pressure inside of the cylindrical space, the compressed air through the

! both nozzle channels flows outwards and thereby the arc cools and blows. The pressure drop continues to lower the pressure above the piston of the fixed contact piece associated valve, with still higher pressure pending below piston j. This will counteract the piston brought into the open position by the pressure of the spring. After the pressure in all areas of the switch through balancing holes has balanced again, the spring predominates and presses the valve assigned to the fixed piston into the Closed position. The compensation openings are designed in the same way as the connection line between the space below of the piston and the cylindrical space accommodating the separation point, so that the compensation takes place with a certain time delay.

Further advantageous developments and advantages of the invention are to be described and explained in more detail using an exemplary embodiment. > It shows

Fig. 1 shows the compressed air switch in the switched-on state and 2 shows the compressed air switch in the switched-off state.

- 4 - i

SOS80770177

ι f; μ '/.' ι i;> oc.M ι

: As is well known, a compressed air switch consists of a central column, j two supports, which ^{are arranged in the form of a fork in relation to this central column 1} and one each running perpendicular to these supports. Compressed air gap chamber. ;

Such a compressed air switching chamber is shown in the drawing represents. ■:

The compressed air switching chamber according to Figures 1 and 2 has a cylinder 1 made of insulating material, on which the switching mechanism 2 with drive 3 and a first valve 4, welctes on the left hereinafter referred to as blow valve 4, and on the right a further arrangement 5 with a second valve 6, which in the following Blow valve 6 is called, connect.

inside the cylinder 1 is one essentially after two; Sides provided by closures 7 and 8 closed cylindrical space 9 in which the movable contact piece | 10 and the fixed contact piece 11 are located. The movable contact piece 10 is guided within a projection 12 on the termination 7 and actuated by a switching rod 13 which is connected to the drive 3. The extension 12 widens towards the end 7 in a widening section 14, so that a space 15 is located between the switching rod 13 and the inner wall of the section 14 of the extension 12. In the switched-on state, the blow valve 4 is seated on a valve seat 16 which is inserted in a recess 17 on the closure 7 'outside of the cylindrical space 9 #. At the edge of the termination 7, a cup-shaped component 18 is connected, which is connected by means of a screw connection 19 to a cylinder 20 leading to the drive 3. The cylinder 20 is closed to the left by means of a hood 21 in which there is a likewise cup-shaped, but stepped component 22 for receiving a compression spring 23. This compression spring 23 presses against a switch rod 13 for holding the drive 3

S09807 / 0177

P-It Λ \ ι (I. "'1!'F.""»'

firmly connected plate 13a and thus also against the switching rod 13 and thus acts on it in the closing direction. The cup-shaped Component 18 has two tadial recesses 24 opposite one another on the circumference. Their function will be described below

: to be explained. The connection of the cylindrical tube 1 j with the closure 7 takes place via a union nut 25 »which j is directly connected to termination 7. In the same way, the end 8 with a union nut 25a with the cylinder 1 connected.

Inside the cylinder 5 located on the right is the blow valve 6, which is seated with an extension 26 on the outside of the closure 8, the blow valve 6 being acted upon by a further compression spring 27 in the closing direction. The blow valve 6 is seated on a valve seat 28, which is inserted in a recess 29 in the closure 8. The blow valve 6 is essentially cylindrical; it therefore has a cylindrical central part 30, to which the extension 26 with a larger diameter adjoins to the left. ',

At its right end, that is to say at the end which is adjacent to the compression spring 27, an edge 31 is provided, which as

the

Piston is used and in the following / is referred to as piston. In this Pistons 31 are axially extending compensating bores 32 introduced. The cylinder 5 now has an inward facing Edge 33 », the inner diameter of which is equal to the outer diameter of the cylindrical central part 30 of the blow valve 6. By the inwardly facing edge 33 and the piston 31, a space 34 is formed, which via a connecting line 35 with the Space 9 in cylinder 1 is connected. The cylindrical middle part 30 is now towards the left, i.e. towards the fixed contact piece 11, completed with a filter insert 36, so that gases occurring during the switching operation are only cleaned in the interior of the blow valve 6 can reach.

509807/0177

The component 5 has outlet openings 37 designed correspondingly to the radial recesses 24. The fixed contact piece 11 is now designed as a nozzle and has a section 11a with a small cross-section, an extension part 11b and a section 11c with a larger cross-section. The movable contact piece is also designed analogously; however, it is in the range of the The narrower section of the projection 12 is slotted so that an air flow as indicated by the arrows A occurs during a switching operation

The mode of operation of the switch according to FIG. 1 will be explained in more detail below.

When switched on, the air within the space 9 is highly compressed, i. H. it has a high pressure. Above the connecting line 35, this high pressure also prevails in the space 34 and via compensating lines via the interior of the

Blow valve 6 also within the nozzle channels of the movable or fixed contact pieces 10 and 11, respectively.

When the movable contact piece moves in the direction of the arrow B during a switching operation, the separation point opens, so that the nozzle channel of the movable contact piece via the separation point 10, the extension section 14 of the extension 12 through the blow valve 4 through the space 9 with the environment the radial recess 24 is in communication. As a result, the pressure in space 9 drops, an air flow according to the arrows A is created. At the same time, however, the pressure in the nozzle channel of the fixed contact piece 11 within the valve 6 and thus also falls but also in the space above the piston 31 on the blow valve 6, so that the force of the compression spring 27 due to the then still pending Overcome high pressure in the space 34 and the blow valve closed | will open. This creates a flow according to the direction of the arrow device C through the channel and through the outlet openings 37 to the outside. The compensation bore 32 and the

- 7 -

connecting line 35 is with such a small cross-section designed so that the decreased pressure in space 9 is not also present in space 34 at the same time. Because in that case it would the force of the compression spring 27 still remains effective.

Over time, however, the pressure above and is equal below the piston 51 on the blow valve 6 and through the compensating bore 32, so that the force of the compression spring 27 again predominates and the blow valve 6 closes. The blow valve 6, which has an extension in the area of section 26, now runs against the inwardly facing edge 33 during this disconnection operation. So that this is possible, is also a compensating bore 39 is provided so that the air from the space 38 via the compensating bore 39 into the space 34 can get. When the blow valve 6 is closed, there is thus no negative pressure in the space 38 that would prevent it from closing would.

509807/0177

f'.il 11 1 t f 71 '11 f.! JO I I ι

Claims (4)

, g. Mp.no. 597/73 g Claims Compressed air switch whose switch room, which is under high pressure when switched on, has at least one fixed and one movable contact piece, each designed similarly to a nozzle, with two valves that allow the gases to flow from the switch room through the contact pieces to the outside, of which the first valve with the movement of the movable one Is coupled contact piece, characterized in that on the fixed contact piece (11) assigned second _; Valve (6) at least one piston (31) is provided, the space (34) below the piston with high pressure and the Space above the piston with the nozzle channel (11c) of the fixed that ! Contact piece is connected, and / between the two spaces | at least one compensating bore (32) is provided, which compensates for pressure within a predetermined period of time allowed, in such a way that the second valve in the event of a switch-off action due to the pressure drop in the nozzle channel and in the room above the piston against the force of a return spring (27) is opened. | 2. Compressed air switch according to claim 1, characterized in that that the space (34) below the piston (31) is connected to the control room (9) via a connecting line (35). 509807/0177 t - j 3. Compressed air switch according to claim 2, characterized in that that the cross section of the connecting line (35) is dimensioned such that a pressure equalization between the space (34) below the piston (31) and the control room (9) time-delayed ■ hesitation is permitted. i
4. Compressed air switch according to claims 1-3 »characterized in that the second valve (6) is approximately cylindrical is formed and at the end opposite the valve seat (28) has a radially outwardly pointing edge, which serves as a piston (31). 509807/0177 JO Blank page