DE1207991B - Device for blow valves for gas pressure switches - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

HOIh

German KL: 21c-35/10

Number: 1207 991

File number: A 46256 VIII d / 21 c

Filing date: June 8, 1964

Opening day: December 30, 1965

ίο

The invention relates to a device for in the immediate vicinity of the contact pieces of compressed gas circuit breakers arranged blow valves, in which the blow valve is a tubular, movable valve member contains, which is positively connected to the movable contact piece and with a annular valve disk cooperates, the interior of the valve member in the closed position below a lower pressure than the space surrounding the valve member outside.

In the case of compressed gas switches, it is known to arrange the blow valve in the immediate vicinity of the contact pieces, the blowing of the contact pieces that separate when switching off and the resulting Initiate the arc as quickly as possible. For this purpose, the movable valve member positively connected to the movable contact piece and both by a common drive device actuated. It has been found to be very useful, the movable valve member ao to be tubular and the movable contact piece ζ. B. in the form of one of several contact fingers to arrange existing tulip contact inside the movable valve member and as a bridging contact to be provided for connecting or disconnecting two fixed nozzle pipes. The arrangement is such that the valve and contact device is located in a switching chamber which is constantly filled with pressurized gas and that in the closed position, the interior of the valve member and the nozzle pipes under a lower pressure than whoever stands in the switching chamber or is connected to the outdoors at all. With the well-known The valve seat, which interacts with the movable valve member, is designed as a fixed valve disk formed, which z. B. is firmly connected to one of the nozzle pipes. The movable valve organ has a drive piston, one side of which is vented to open, in which case the Valve element through the switching chamber pressure on the other side in the opening direction is moved. However, the arrangement still has a certain disadvantage, which is that in the starting phase of the opening movement only a relatively small effective drive surface is present is and thus a small driving force is exerted on the movable valve member. With modern With compressed gas switches, however, efforts are made to achieve a very rapid switching piece opening, in particular even at the moment of contact separation, a possible high speed of the moving Switching piece is desired.

Device for blow valves on gas pressure switches

Applicant:

Public limited company Brown, Boveri & Cie., Baden

(Switzerland)

Representative:

Dr.-Ing. E. Sommerfeld, patent attorney,

Munich 23, Dunantstr. 6th

Named as inventor:

Dipl.-Ing. Salvatore Giammona, nut trees;

Ruhi Utku, Baden (Switzerland)

Claimed priority:

Switzerland of 25 May 1964 (6812)

This requirement can be met for pressure gas switches, in which the movable contact with the movable Part of the blow valve is connected, according to the invention thereby achieve in a simple manner that the valve plate is mounted displaceably in the direction of movement of the valve member and one in the closed position effective first piston, which as a starting piston during the first partial stroke of the Opening movement is used for additional acceleration of the valve member, and that the valve disc has a second piston, which after opening the blow valve, the return of the valve disk in its starting position. On the one hand, this results in very short switch-off times of the switch, on the other hand, the sealing element and the valve seat of the blow valve are largely protected against the harmful effects of the arc.

With reference to the drawing, which shows an embodiment according to the invention, the latter is described in more detail below. In the drawing, the stationary nozzle pipes are denoted by 1, 2, which are arranged in a manner known per se within a switching chamber not shown in detail. The nozzle tube 1 is surrounded by the guide cylinder 3, the tubular, movable valve member 4 with its drive piston Aa being slidably guided between the two parts 1, 3. The closing spring 5 is supported on the one hand against the piston 4 a and on the other hand against a

509 760/262

Fixed abutment, not shown in detail. The space 6 located above the piston 4 a serves as a control space, which is filled with compressed gas in a manner known per se via a control valve for closing the blow valve and emptied for opening. 7 with a contact finger is referred to, the several of which are arranged distributed on the circumference and are pressed together by means of the springs 8 in a known manner and thus form a tulip-shaped contact basket. The contact fingers 7 are arranged within the valve member 4 and are positively connected to the latter via the projections la. The valve member 4 is designed at its lower end as a valve seat 4 b , which cooperates with the sealing ring 10 embedded in the annular valve disk 9. The valve disk 9 has a first piston 9 a, which is mounted so as to slide tightly on the nozzle tube 2, and a second piston 9 b, which engages in the annular recess la. The lower side of the piston 9b is connected to the outside via the channel 2ö in the nozzle pipe 2.

The mode of operation of the arrangement is as follows: In the position shown, the blow valve is closed, the valve member 4 being pressed with its valve seat 4b against the sealing ring 10. This is done in that the valve member 4 is pressed downwards by the control pressure prevailing in space 6, the effective area being that of the two diameters d _v d. ₂ limited circular ring area is decisive, since the circular ring area enclosed between the diameters d ₃ , d ₂ , which is acted upon by the gas pressure prevailing in the surrounding space 11, results in an upward force component on the valve element 4. Here, for the sake of simplicity, it is assumed that the pressures in the spaces 6 and 11 are the same and the interior of the valve member 4 and the nozzle pipes 1, 2 z. B. stand under atmospheric pressure. In an analogous manner, an upward force ₂ enclosed annular surface of the piston to the valve plate 9 exerted which, i.e. from the pressure in the space 11 and the (d between the diameters 9 a result. In the selected embodiment is d _t = d _t ', so that the system consisting of parts 4 and 9 is in pneumatic equilibrium towards the outside. Parts 4 and 9 are held in the lower limit position by spring 5, which is caused by the piston 9b beating against the lower end face of the recess 2 is intended a. to open the blow valve of the chamber 6 is vented. Here, the system valve member-valve disc is very fast moving, because after a relatively low Duck drop in the chamber 6 a sufficient power surplus to top is formed which extends from the The pressure difference in the spaces 11 and 6 times the large circular ring area enclosed by the diameters d _? And <2 / (= CU _{1) results} Hase the valve disk 9 by virtue of its piston 9 a thus acts as a starting aid to accelerate the valve member 4 within the guide cylinder 3. This happens during the first partial stroke, which is limited by the fact that the piston 9 b with its upper surface against the during its upward movement upper end face of the recess la strikes. In the further course of movement, the valve seat 4 b then lifts off the sealing ring 10, so that the compressed gas can now reach the switching point from the space 11. In this case, the pressurized gas enters at the same time to the upper surface of the piston 9 b is returned whereby the valve plate 9 quickly back to its lower limit position, because the piston 9 b on its lower side through the channel 2 b is connected to the outside. This return of the valve disk 9 has the advantage that the seal is quickly moved outside of the zone in which it would otherwise be endangered by the effects of arcing, metal splashes, etc. rapidly enlarged.

Claims (3)

Patent claims: 1. Device for a blow valve arranged in the immediate vicinity of the switching pieces of compressed gas circuit breakers, which contains a tubular, movable valve member which is positively connected to the movable switching piece and interacts with an annular valve plate, the interior of the valve member in the closed position under a lower pressure than the space surrounding the valve member stands, characterized in that the valve plate (10) is mounted displaceably in the direction of movement of the movable valve member and has a first piston (9 a) which is effective in the closed position and which acts as a starting piston during the first partial stroke of the opening movement Acceleration of the valve member is used, and that the valve disk has a second piston (9 b) which, after opening the blow valve, brings about the return of the valve disk to its starting position. 2. Device according to claim 1, characterized in that the valve plate is tightly slidingly mounted on the switching piece assigned to it and its second piston (9 b) engages in a recess of the switching piece, which on the side facing away from the valve member via a channel constantly with the Outdoors is connected. 3. Device according to claim 1 and 2, characterized in that the second piston also serves as a stop for the valve disk movements. 1 sheet of drawings 509 760/262 12.65 © Bundesdruckerei Berlin