EP2686862A1

EP2686862A1 - Magnet system and installation switchgear

Info

Publication number: EP2686862A1
Application number: EP12707758.4A
Authority: EP
Inventors: Ralf Wieland; Wolfgang Pump; Klaus-Peter Eppe; Rainer Ludovici
Original assignee: ABB AG Germany
Current assignee: ABB AG Germany
Priority date: 2011-03-16
Filing date: 2012-03-07
Publication date: 2014-01-22
Anticipated expiration: 2032-03-07
Also published as: DE102011014061A1; EP2686862B1; DE102011014061B4; CN103477412A; WO2012123307A1; CN103477412B; AR088725A1

Abstract

The invention relates to a magnet system (1) for a line circuit breaker (2), with a yoke (3), a coil (4), a sleeve (5), a magnet core (6), a plunger (7), a magnet armature (8) and a restraint spring (9), wherein a conductor piece (10) is formed on the yoke (3) and bears a fixed contact piece (11), and wherein the magnet armature (8) is guided movably in the sleeve (5) counter to the force of the restraint spring (9). The magnet core (6) is fastened on the conductor piece (10), the sleeve (5) is in engagement with the magnet core (6) at the first end of said sleeve, and the magnet armature (8) can be guided into and out of the sleeve (5) at the second end of the sleeve (5).

Description

Magnetic system and installation switching device

The invention relates to a magnet system for a circuit breaker, comprising a yoke, a coil, a sleeve, a magnetic core, a plunger, a magnet armature and a captive spring, wherein on the yoke, a conductor piece is formed, which carries a fixed contact piece, and wherein the armature is guided displaceably in the sleeve against the force of the restraint spring, according to the preamble of claim 1. The invention further relates to a method for producing a magnet system, according to the preamble of claim 8.

The invention further relates to a circuit breaker with a Isolierstoffgehäuse and with a magnet system, according to the preamble of claim 9.

A generic magnet system is shown, for example, in DE 198 45 476 A1.

Circuit breakers with magnetic systems are used in electrical engineering to protect circuits against overload, z. As by short circuits or the like, and are used to automatically disconnect a line, d. that is, they trigger when such an overload occurs. For some possible overload cases, a magnet system is used to trip the circuit breaker. The magnet system has a movable armature, which in the rest position partially protrudes into a current-carrying coil flowing from the current in the line to be monitored. If the current in the coil is greater than a predetermined tripping current, the armature is displaced by the resulting magnetic field of the coil and triggers the circuit breaker via a plunger. Because the coil always from the monitored

Current flows through, the trigger element, ie armature and plunger, must selfeder be kept in a defined rest position to ensure a defined response of the circuit breaker and to avoid false tripping. Consequently, the magnet system must contain a plurality of different mechanical parts to ensure this reliability. To assemble this plurality of mechanical parts is time consuming and consequently expensive. For compliance with a predetermined triggering behavior, it is also significant that the air gap of the magnetic circuit of the magnet system is as independent of tolerances in manufacturing adjustable, which is why known magnetic systems sometimes quite expensive design measures provide for this.

It is therefore the object of the present invention to develop a magnet system such that its construction requires fewer parts and its assembly is further simplified, and to provide a method for its production. Further, it is an object of the present invention to develop a circuit breaker with a magnet system so that the assembly of the magnet system in the

Circuit breaker further simplified and also the air gap of the magnetic circuit of the magnet system is tolerance independent.

The object is achieved with respect to the magnet system by a magnet system having the features of claim 1.

With regard to the method for producing a magnet system, the object is achieved by claim 8.

The object with respect to an improved circuit breaker is achieved by a circuit breaker having the features of claim 9.

Thus, according to the invention, the magnetic core is fixed to the conductor piece, and the sleeve is engaged with the magnetic core at its first end, and the magnet armature is insertable and executable into the sleeve at the second end of the sleeve.

A magnet system according to the invention has very few individual parts, which in some cases assume multiple functions, is therefore very easy to assemble, even fully automatically at high speed. Thus, the magnetic core in addition to its actual function as a magnetic core in the magnetic circuit of the magnet system still fulfills the function of a holding member for the sleeve. A separate holding device for the mag- Net system is not required, since according to the invention, the magnetic core is attached to the conductor piece, and the conductor piece, since it carries the fixed contact piece, must be held in the housing of a service switching device anyway. Thus, the magnet system is held on the holder of the conductor piece with the fixed contact when mounted in the housing, the sleeve is held over the magnetic core, and the armature is held in the sleeve. A rearward stop for the armature can be provided outside the magnet system, as the armature is insertable and executable into the sleeve at the second end of the sleeve. Therefore, the magnet system according to the invention is suitable for determining the distance between the magnet core and the magnet armature, which determines the air gap of the magnet system, by abutment means located outside the magnet system and thus can be adjusted independently of manufacturing tolerances of the magnet system.

According to an advantageous embodiment of the invention, the magnetic core has a penetrated by the plunger bore. This hole also acts as a guide member for the plunger, so that an independent guide member, as required in the prior art, is eliminated.

According to an advantageous embodiment of the invention, the bore is a stepped longitudinal bore with a larger diameter at the end facing away from the conductor piece end, and the diameter step forms a first stop for the fetlock feather. As a result, the restraint spring is mounted against rotation, an additional holding part for the restraint spring is not required.

According to an advantageous embodiment of the invention, the outer surface of the magnetic core, at least in the area of engagement with the sleeve, has a surface configuration which increases the friction between the magnetic core and the sleeve in this area. This can be done for example by an external circumferential structuring of the outer surface, such as a kind of corrugation or roughening over which the sleeve is pushed and thereby better holds, without a further fastening means, such as an adhesive layer, must be provided. According to an advantageous embodiment of the invention, the plunger is inserted into a blind hole-like depression on an end face of the magnet armature and fastened therein. Untitled. This can be realized for example by the fact that the plunger is pressed into the armature. This has the advantageous effect of an optimized, better return of the armature. Such a measure to be provided according to the invention has a particularly favorable effect on the tolerances in the flow. According to an advantageous embodiment of the invention, the end face of the magnet armature forms the second stop for the fetlock spring. For this purpose, it advantageously has no contouring, that is to say in particular no hole or milled recess, in order to receive the fetlock spring. Advantageously, the restraining spring lies against the smooth end face. This has the advantageous effect of undisturbed and thus further improved magnetic properties of the magnetic circuit of the magnet system, which in particular causes a higher armature force.

According to an advantageous embodiment of the invention, the magnetic core is riveted to the conductor piece.

A method according to the invention for producing a magnet system is characterized in that it comprises the following steps:

Attaching the magnetic core to the conductor piece,

Sliding the sleeve onto the magnetic core,

Sliding the restraining spring onto the ram formed on the armature,

Inserting the magnet armature with the tappet formed thereon and the restraining spring pushed thereon into the sleeve,

- Inserting the magnetic core, conductor piece, sleeve formed with inserted magnetic core unit into the housing of a service switching device.

An inventive circuit breaker with a Isolierstoffgehäuse and with a magnetic system is characterized in that on the inside of the insulating material housing two bearing members are formed at a fixed distance from each other, wherein a first bearing member for holding the conductor piece and the second bearing member are designed as a stop for the armature , The first bearing member may be formed, for example, by two spaced apart the thickness of the conductor piece side by side on the inside of the housing webs, between which the conductor piece is clamped for attachment. The second bearing member may be a shoulder on the inside of the housing, which serves as a stop for the armature, ie, the Magnetic armature can not be pushed out of the sleeve by the restraint spring as far as this stop in the resting state.

According to an advantageous embodiment of the invention, the air gap of the magnet system determining distance between the magnetic core and the Magnetan- ker by the distance between the two bearing members can be fixed. The air gap of the magnetic circuit, so the distance between the magnetic core and the armature, is thus determined via two contact points in the housing. These bearing points can be kept in the housing exactly to each other, which has the consequence that according to the invention the air gap is tolerance independent.

Reference to the drawings, in which an embodiment of the invention is shown, the invention and further advantageous refinements and improvements of the invention will be explained and described in detail.

Show it:

Figure 1 shows an embodiment of a magnetic system according to the invention, Figure 2 is a view of a magnet system used in a housing of a service switching device of FIG. 1, and

FIG. 3 shows a sectional view of the magnet system according to FIG. 1 inserted in a housing of an installation switching device.

In the figures, identical or equivalent components or elements are designated by the same reference numerals.

Figure 1 shows a magnet system 1, as constructed according to the invention and in a circuit breaker 2, see Fig. 2 and 3, is used. Further details and other components of a circuit breaker, which are usually present in such, such as rear derailleur, overcurrent release, Lichtbogenlöschein- direction with arc guide rails and arc splitter stack and so on are not shown here.

The magnet system 1 has a yoke 3, here an L-shaped metal yoke, with a long leg 21 and an approximately right angle bent thereon short leg 22nd On the short leg 22, a conductor piece 10 is welded flat. The conductor piece 10 carries a fixed contact piece 1 1 and extends in the extension of the short leg 22 downwards, where it ends in an approximately U-shaped curvature, which forms a Festkontaktleitschiene. The conductor piece 10 is formed with a first plate 23 which is welded directly to the short leg 22. At the first plate 23 is projecting at an angle of approximately 45 ° projecting a second plate 24, which thus extends obliquely downwards. To the second plate 24, the U-shaped curvature 25 is formed.

In Figure 2, a contact lever 27 is shown schematically with a movable contact piece 28 which forms the contact point of the circuit breaker 2 with the fixed contact piece 1 and from which a movable wire 29 emanates, which continues the current path in the circuit breaker inside.

The short leg 22 and the conductor piece 10 each have a bore which lie one above the other in welded state and thus form a common passage through the conductor piece 10 and the short leg 22.

Through this passage, the free end of a magnetic core 6 is pushed through, so that it projects beyond the outer side of the conductor piece 10 this piece and riveted to this side by crimping.

The magnetic core consists of a ferromagnetic material and has a cylindrical outer contour and a stepped longitudinal bore 14. The larger diameter is located on the side facing away from the conductor piece 10 side, the smaller diameter is located on the conductor piece 10 side facing.

The diameter step 15 forms a stop for a cylinder spring 9, which acts as a restraining spring. The restraint spring 9 is inserted from the side of the larger diameter ago in the longitudinal bore 14 until it comes to the stop at the diameter stage 15.

A coil tube, also referred to as sleeve 5, made of insulating plastic material is pushed from the outside over the outer surface of the magnetic core 6. Thus, the sleeve 5 can not slide down again, the outer surface of the magnetic core 6 has a surface contouring, such as a corrugation, which the frictional force between the outer surface of the magnetic core 6 and the inner surface of the Sleeve 5 increases. The sleeve is pushed with a certain interference fit on the outer surface of the magnetic core 6, supported by the surface contouring and thereby increased sliding and static friction holds the sleeve 5 then on its own on the magnetic core 6, there is no further operation for securing the sleeve fifth on the magnetic core 6 of need.

Over the outer surface of the sleeve 5, the coil 4 is pushed, which is flowed through by the current flowing through the circuit breaker current. Depending on the size of the rated current and the short-circuit current to be disconnected, this coil can have more or fewer turns with different cross-sections. In the example shown here, the coil has only 3 turns and a large, rectangular cross-section. It is thus suitable for switching off a large short-circuit current. The coil 4 is connected via a first connection conductor 26 to the second plate 24 of the conductor piece 10. Both are welded directly together, thus resulting in a low contact resistance and a total low electrical resistance of the current path.

The first connection conductor 26 also forms an angle of approximately 45 ° with the first plate 23. This oblique course of the connecting conductor 26 and the second plate 24 has the following advantage. When opening the contact point in the event of a short circuit between the fixed contact piece 1 1 and the movable contact piece 28, an arc that initially carries the stream even further over the contact point. The dashed lines 30, 31 and the curved arrow 32 in Figure 2 illustrate that the current path over the arc in this state takes a curved or loop-shaped course. The magnetic field associated with this looping action acts on the arc to propel it away from the pad and toward the baffles and arc splitter stack (not shown in the figures herein); It is also said that the arc is blown away, and the configuration of first terminal conductor 26, second plate 24 and movable contact lever 27 with strand is also referred to as Blasschleife. Due to the oblique course of the second plate 24 and the first connecting conductor 26, the blowing loop here has a wide opening, resulting in a large blowing loop, which is advantageous in the sense of a strong blowing effect. At the other end of the coil 4 is a second connection conductor 33, which is connected to a connection terminal 34.

The magnet armature 8 has a cylindrical shape, with an outer diameter, which is dimensioned so that it can easily slide along with its outer surface on the inner surface of the sleeve 5, without forming a too large air gap.

On an end face 17 of the magnet armature 8 has a blind hole-like depression into which a plunger 7, formed approximately in the form of a round pin or a round rod, is pressed and then held therein without further measures for attachment, such as welding , gluing or the like, need to be provided.

Apart from the blind hole for pressing in the plunger 7, the end face of the magnet armature 8 has no further surface contour. The end face thus represents in the embodiment according to the invention a smooth surface. This is advantageous because it results in a higher anchor force. Because decisive for the height of the magnetic force, the anchor force, the area in the region of the air gap and the air gap width. The inventive design results in a large anchor surface in the region of the air gap and thus in a large anchor force.

The restraint spring 9 is pushed over the pressed into the armature 8 plunger 7. From the open side of the sleeve 5 ago then the armature, with the plunger 7 ahead, inserted into the sleeve 5. The smaller diameter is just so large that the plunger 7, which is connected to the armature 8, can slide therethrough. The plunger 7 thus slides through the bore 17 until it looks out at the opening in the conductor piece 10 a piece. The restraint spring reaches the diameter step.

The armature 8 looks at the free end of the sleeve 5 a little way beyond the sleeve 5 out.

The width of the air gap of the magnetic circuit of the magnetic system 1 can be fixed by the distance of the end face of the armature 8 of the magnetic core 6. In the case of short-circuit current tripping the magnet armature 8 is pulled into the sleeve 5 due to the magnetic force effect of the coil current, and thus the tappet is driven out of the sleeve to the left and can open the contact lever to open the contact point. An advantage of the inventive design of the mag- Netankers as a cylinder without further Oberflächenkonturierung is that no further air gap between the armature and the inner surface of the sleeve 5 is formed when the magnet armature is pulled into the sleeve 5 inside. If such an air gap arises, as is the case for example in the prior art according to DE 198 45 476 A1, this reduces the anchor force. In the embodiment according to the invention, however, such an air gap does not arise.

In order to be able to comply with the width of the air gap at rest with low manufacturing tolerance, the magnet system 1 is inserted into the circuit breaker 2, and thereby the conductor piece 10 between two spaced apart the thickness of the conductor piece side by side on the inside of the housing integrally formed webs 34th , 35, which together form a first bearing member 18, introduced and held, while a paragraph 19, also referred to as a second bearing member 19, serves as a stop for the armature 8 on the inside of the housing. The width of the air gap is thus determined by the distance between two bearing members 18, 19 or contact points in the housing, not by parts of the magnet system itself. The contact points 18, 19 connected to the housing can be adjusted to each other by precise housing production in an exact position and maintained with high reproducibility be, whereby the air gap is independent of manufacturing tolerances of the magnet system.

Due to the foregoing description, it is clear that the magnet system according to the invention is very simple and easy to assemble. The magnet system is built up step by step on the yoke. First, the magnetic core is riveted to the yoke. The sleeve is pushed onto the magnetic core, the magnet armature with the plunger are pushed into the sleeve, the coil we pushed over it, all together is inserted into the housing. It is not necessary to make complicated assembled subassemblies and then assemble them. But few parts are successively pushed up and pushed together, and the critical parameter of the air gap width is adjustable by a housing size, namely the set outside the magnet system distance between the two contact points for the conductor piece on the one hand and the armature on the other hand, with low tolerance.

It will be readily apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiment. and that the present invention may be embodied in other specific forms without departing from essential attributes thereof, and it is therefore to be construed that the present embodiments are considered in all respects to be illustrative and not restrictive, with more reference to the appended claims as referred to in the foregoing description, it is therefore intended that all variations which come within the meaning and range of the claims' equivalence be included therein.

LIST OF REFERENCE NUMBERS

1 magnet system

2 circuit breaker

3 yoke

4 coil

5 sleeve

6 magnetic core

7 pestles

8 magnet armature

9 restraining spring

10 conductor piece

1 1 fixed contact piece

12 first end of the sleeve

13 second end of the sleeve

14 hole

15 diameter step

16 blind hole-like depression

17 front side

18 first bearing element

19 second bearing member

20 insulating housing

21 long thigh

22 Short thigh

23 First record

24 Second plate

25 U-shaped vault

26 First connection strip

27 contact lever

28 Movable contact piece

29 strand

30 Dashed line

31 Dashed line

32 Arrow-shaped arrow

33 Second connection strip

34 footbridge

35 footbridge

Claims

claims

1 . Magnetic system (1) for a circuit breaker (2), comprising a yoke (3), a coil (4), a sleeve (5), a magnetic core (6), a plunger (7), a magnet armature (8) and a fetlock spring (9), wherein on the yoke (3) a conductor piece (10) is formed, which carries a fixed contact piece (1 1), and wherein the armature (8) in the sleeve (5) against the force of the restraining spring (9) displaceable is guided ,.

characterized in that the magnetic core (6) is fixed to the conductor piece (10), that the sleeve (5) is engaged at its first end with the magnetic core (6), and that the magnetic armature (8) at the second end of the Sleeve (5) in the sleeve (5) and is executable.

2. Magnetic system (1) according to claim 1, characterized in that the magnetic core (6) has one of the plunger (7) through-drilled bore.

3. magnet system (1) according to claim 2, characterized in that the bore is a stepped longitudinal bore with a larger diameter at the end remote from the conductor piece (10) end, and that the diameter step forms a first stop for the restraint spring (9).

4. magnet system (1) according to claim 1, characterized in that the outer surface of the magnetic core (6) at least in the region of engagement with the sleeve (5), the friction between the magnetic core (6) and the sleeve (5) in this Have area-increasing surface configuration.

5. magnet system (1) according to claim 1, characterized in that the plunger (7) is inserted into a blind hole-like depression on an end face of the magnet armature (8) and secured therein.

6. magnet system (1) according to claim 3, characterized in that the end face of the magnet armature (8) forms the second stop for the restraint spring (9).

7. magnet system (1) according to claim 1, characterized in that the magnetic core (6) with the conductor piece (10) is riveted.

8. A method for producing a magnet system (1) according to claim 1, characterized in that it comprises the following steps:

- Attaching the magnetic core (6) on the conductor piece (10),

Sliding the sleeve (5) onto the magnetic core (6),

Sliding the restraining spring (9) onto the ram (7) formed on the magnet armature (8),

Inserting the magnet armature (8) with the tappet (7) formed thereon and the restraining spring (9) pushed thereon into the sleeve (5),

- Insertion of the magnetic core (6), conductor piece (10), sleeve (5) formed with inserted magnetic core (6) in the housing of a service switching device.

9. Circuit breaker (2) with an insulating material and with a magnet system (1) according to claim 1, characterized in that on the inside of the insulating two housing members are formed at a fixed distance from each other, wherein a first bearing member for holding the conductor piece (10) and the second bearing member are designed as a stop for the armature (8).

10. Circuit breaker (2) according to claim 9, characterized in that the air gap of the magnet system (1) determining the distance between the magnetic core (6) and the armature (8) can be fixed by the distance between the two bearing members.