EA006044B1 - Yoke comprising a single element fixed contact carrier - Google Patents

Abstract

The invention relates to a yoke (1) for a magnetic system of a short circuit triggering device (16), especially for mounting in a circuit-breaker. Said short circuit triggering device (16) comprises a fixed contact carrier (2), a coil (4) with a core (5), an armature (9) which can be moved in the coil (4), and the yoke (1) carrying the core (5). In the event of a short circuit, the armature (9) is impacted by the magnetic forces produced in the coil (4) by the short circuit current, against a switching device (22) which causes the interruption of the current, the fixed contact carrier (2) being embodied as a single element with the yoke (1).

Description

SUBSTANCE: invention relates to a yoke for a magnetic system of a short-circuit current release, in particular, for mounting in a linear automatic circuit breaker, which includes a fixed contact holder, an armature coil, an anchor movable in the coil and a yoke bearing core, and in the case of a short circuit, the armature by magnetic forces produced by the short-circuit current in the coil, hits the switching mechanism that causes the current to go off.

Such a yoke is well known, in particular, in the field of designing linear circuit breakers. With these short-circuit releases, the fixed contact holder is, however, performed as a separate part and connected to the yoke of the short-circuit release. The disadvantage of this is the complicated construction, since a separate operation is needed to join both parts by welding or rivets.

Document ΌΕ-Α1-19845476 describes a magnetic system for linear circuit breakers. There is a coil wound on a sleeve and an anchor with an executive pusher mounted in the sleeve with the ability to move. At the first end of the sleeve, an insert is fitted on which the support part is fixed. This bearing part covers, on the one hand, a segment running parallel to the end side of the coil, and, on the other hand, a holder of a fixed contact, as well as an arc-guide plate adjacent to it. Both of these components are made in the form of a solid structural element. In FIG. Two forms of execution in the sleeve of the coil is placed magnetic core, which is adjacent to the bearing part. This core is only pressed in or glued into the sleeve (see column 4, lines 16-18). This results in the disadvantage that due to the gap formed between the core and the sleeve, which can be filled with air or glue, magnetic losses can occur in the magnetic system.

The magnetic system for linear circuit breakers according to EP-A1-569652 has a cylindrical coil, inside which there is a fixed core and an anchor mounted for movement. The anchor is connected to a percussion pin protruding from the coil. The magnetic yoke encompasses the first plate extending parallel to one end side of the coil, the second plate extending parallel to the other end side of the coil and connecting the two plates to a transverse web. The second plate is extended beyond the coil zone and forms a holder for fixed contact, as well as an arc-guide plate adjacent to it. In particular, from FIG. 8 it follows that the core 85 located inside the coil is made as a separate part from the magnetic yoke 34. From this, again, the disadvantage that the resulting gap between the core and the magnetic yoke, which can be filled with air, may cause magnetic losses in the magnetic system.

The objective of the invention is to create a yoke, which would eliminate the above disadvantage and provide a simpler design of short-circuit release, in particular, for mounting in a linear circuit breaker.

According to the invention, this is achieved due to the fact that the holder of the fixed contact is made in one piece with the yoke.

By performing the yoke in one piece with the fixed contact holder, both parts can be manufactured in one operation, i.e. on one machine. Any operations for the manufacture of joints between parts, in particular the riveting or welding process, are eliminated. This leads to time savings in the manufacture of short circuit current releases.

According to another embodiment of the invention, it can be provided that the core is also made in one piece with the yoke, in particular in the form of a cup made by deep-drawing.

This provides the additional advantage that any operations for connecting the core and the yoke also disappear. In addition, any air gap between the core and the yoke is thereby excluded. Corresponding to the state of the art, the core and yoke are made as separate parts from each other because of these air gaps in the magnetic system there are magnetic losses. This is excluded due to the improvement according to the invention.

The invention is described in more detail with reference to the accompanying drawings, in which particularly preferred embodiments are shown. In the drawings are:

FIG. 1 is a top view of a linear circuit breaker fitted with a yoke 1 according to the invention with the top cup removed;

FIG. 2 shows an embodiment of a yoke 1 with a core 5 according to the prior art, in plan, partially in section;

FIG. 3 shows another embodiment of a yoke 1 according to the invention with an inserted anchor block 6 in plan;

FIG. 4 shows another embodiment of a yoke 1 according to the invention with a second longitudinal side 16 of a yoke in plan, partially in section;

FIG. 5 shows an embodiment of a yoke 1 according to the invention with a deep-drawn core 5 made in perspective;

FIG. 6 - anchor block 6 for the yoke 1 according to the invention with a riveted core 5 in plan, partially in section;

- 1 006044 FIG. 7 - a short-circuit release 16 with a yoke 1 according to the invention and a welded clamping angle 8 in perspective.

A single-phase circuit breaker according to the invention is made, as is best seen from FIG. 1, similar to a conventional line circuit breaker.

It mainly includes two screw terminals 14, 15 for connecting a monitored line, a release element 17 for protection against overloads, a short-circuit release 16, and a switching mechanism 22 next to it, which can move the movable contact 7 'from a closed position to the open position shown in FIG. one.

In normal working condition, the monitored current flows in this protective circuit breaker, going from the first screw terminal 14, first through the release element 17 for protection against overloads through the moving wire 19 and the bridge contact 20 to the moving contact 7 ', then through the fixed contact 7 - to the short-circuit current release 16 and finally to the second screw terminal 15.

The switching mechanism 22 can be actuated both by the tripping element 17 for protection against overloads and by the short circuit release 16 as described below.

The release element 17 for overload protection consists in a known manner of a bimetallic strip 18, which is heated by a controlled current. The first end 18a of the bimetallic strip 18 is installed in the case of the circuit breaker, and the second end 18b is kept freely movable. The bending of the latter caused by the heating of the bimetal therefore leads to the movement of the second end 18b along the arrow Δ18. With sufficiently strong heating, the free end 18b of the bimetallic strip 18 contacts during this movement with the yoke 21 acting on the switching mechanism 22, seizes it in the direction of movement and causes thereby the switching mechanism 22 to trigger.

The short circuit release 16 includes a magnetic coil 4 with an iron core 5 (not shown), a yoke 1 according to the invention, and a moving armature 9 (also not shown). In the event of a short circuit and at correspondingly high short circuit currents, a rapid change in the magnetic flux in the coil 4 causes the anchor 9 to move in the direction of the switching mechanism 22, and the pusher 10 connected to it hits the bridge contact 20 of the switching mechanism 22.

The bridge contact 20 is tensioned by the spring 24 in the direction of the open position of the movable contact 7 '. In the case of tripping, i.e. when overloaded or short-circuited, the mentioned minor deviations of the bridge contact 20 by the pusher 10 of the short-circuit release 16 or by the release element 17 for protection against overloads are amplified through the collar 21 by means of the spring 24 to fully rotate the bridge contact 20 to the open position of the movable contact 7 '.

The arc formed by opening the movable contact 7 ′ between the fixed 7 and movable 7 ’contacts is guided by a conically expanding arc gap 30, the walls of which are formed by extending 2a of the fixed contact holder 2 and the arc guide plate 32. The arc moves in a known manner along the expanding arc gap 30 and is extinguished adjacent deionic chamber 34, containing several installed one above the other deionic plates, and the extinguishing gases are discharged through the outlet 35.

To turn on the safety switch, i.e. for turning back the bridge contact 20 to the closed position of the movable contact 7 ', a lever 25 accessible from the outside is provided, which is pressed by hand.

The body of the circuit breaker according to the invention is made in a manner known per se from two frequencies, from the bottom cup 26 and the top cup (not shown).

This invention relates to a special form of the yoke 1 of the short-circuit current splitter 16 in combination with the framing of the arc gap 30 formed by means of the holder 2 of fixed contact, in particular for mounting in a circuit-breaker. The invention is not limited, however, to the use of this short-circuit release 16 in linear circuit breakers. In the drawings, the line circuit breaker and its case were shown because this is a particularly preferred application area of the yoke 1 according to the invention. Yoke 1, in spite of this, can also be used in other circuit breakers or in other electrical devices, including a short-circuit release.

FIG. 2 shows the magnetic system of the short-circuit release 16 (FIG. 1), which includes the coil 4 with the core 5 and the yoke 1 according to the invention. Next, the short circuit release 16 includes a holder 2 of a fixed contact and pin 1 placed on it, for example in the form of a silver plate. The continuation 2a of the holder 2 of the fixed contact is made in the form of a guide plate of the arcing gap 30. In FIG. 2 does not show the anchor block 6 which is worn on the core 5 of the coil 4

Coil 4 consists of copper wire and has only a small number of turns. With its first end 4a, it is welded to yoke 1 on its first end side 1a, and with its second end 4b to the contact foot 8a of the clamping angle 8 (Fig. 7). 2 fixed contact holder and its servant

- 2 006044 continuation plate 2a made according to the invention in one piece with the yoke 1.

In the closed state of the automatic circuit breaker, the movable contact 7 'is in contact with the fixed contact 7, whereby the current is directed through the holder 2 of the fixed contact, the first end side 1a of the yoke 1, the coil 4 and the clamping angle 8 to the second screw terminal 15.

The yoke 1 according to the invention, made in one piece with the holder 2 fixed contact, the coil 4 with its first end 4A is welded directly to the yoke 1, and it does not have to be welded, as in the known embodiments, made as a separate part holder 2 fixed contact. For this, the yoke 1 itself is made of a conductive material or is coated with a conductive material, for example, galvanized by a copper layer.

Anchor block 6 (Fig. 6) includes a sleeve 12 for the coil, in which the anchor 9 is mounted for movement in the position Δ9, i.e. in the direction of the core 5 coil. The anchor 9 places the pusher 10 in the recess 10. The pusher 10 and the anchor 9 are tensioned by the spring 11 of the pusher against the direction Δ9, i.e. from the core 5 coil.

The coil core 5 is made in FIG. 2, as in the prior art, as a separate part of the rotation, which is riveted with a yoke 1 on its first end side 1a. This core 5 extends into the inner space between the two end sides 1a, 1c of the yoke 1 and has a bearing surface 5a facing the second end side 1a of the yoke on which the armature hits in case of a short circuit, as well as the hole 5b for accommodating the pusher 10.

The core 5 of the coil according to the invention, as shown in FIG. 3 and 5, is made in one piece with the yoke 1 and the holder 2 of fixed contact or with serving as an arc-guide plate continuation 2a of the holder 2 of fixed contact. In this case, the coil core 5 is preferably formed by a deep-drawing cup made on the first end side 1c of the yoke 1. Also, the cup extends into the inner space of the yoke 1 and forms the bearing surface 5a for the armature 9 and the hole 5b for accommodating the pusher 10 (Fig. 5).

FIG. 3, the anchor block 6 with the coil sleeve 12 (FIG. 6) is fitted onto the coil core 5 (FIG. 4), and the distance between the armature 9 and the coil core 5 is calculated so that the pusher 10 is in working condition, i.e. in the closed state The circuit breaker does not come into contact with bridge contact 20.

To prevent the losses in the magnetic core in the best way, the yoke 1 is ϋ-shaped bent around the coil 4. On the second end side 1c opposite to the first end side 1a, a hole 3 is provided to enter the anchor block 6. However, it may also be provided that the yoke 1 is made according to the invention in one piece with the fixed contact holder 2, without a second end side 1c, which leads to a particularly light construction, or, as shown in FIG. 4, to provide the second longitudinal side 16 in order to close the magnetic conductor also on the side opposite to the first longitudinal side 1b of the yoke 1.

In the event of a short circuit, the magnetic forces caused by an increase in the current in the coil 4 cause the armature 9 to move against the resistance of the pusher spring 10 in the direction of the core 5. When the short circuit currents are sufficiently strong, the pusher 10 hits the bridge contact 20 of the switching mechanism 22, resulting in actuation of the switching mechanism 22. Due to this, the bridge contact 20 rotates to the fully open position of the movable contact 7 ', and the contact is interrupted.

The arc arising due to the opening of the contact 7 'between the fixed 7 and the movable 7' contacts, proceeding from the fixed contact 7, is guided by the arc gap 30. The first guide plate of the arc gap 30 is therefore made as a continuation 2a of the holder 2 of the fixed contact.

FIG. 7 depicts a yoke 1 according to the invention with a clamping arm 8 welded to the second end 4b of the coil 4 and a screw clamp 15. The detail shown forms a knot and can be very easily, with a single hand movement or in an automatic production line, inserted into the case of the circuit breaker.

Claims (1)

CLAIM The yoke (1) for the magnetic system of the short-circuit current release (16), in particular for mounting in a linear circuit breaker, the short-circuit release (16) includes a fixed contact holder (2), a coil (4) with a core ( 5), the armature (9) moving in the coil (4) and the yoke (5) carrying the core (5), and in the case of a short circuit, the armature (9) through the magnetic forces generated by the short circuit current in the coil (4), hits the switching the mechanism (22), which causes a blackout, characterized in that they hold the spruce (2) of the fixed contact and the core (5) are made in one piece with the yoke (1), and the core has the shape of a cup made by deep drawing.