EP3221879A1

EP3221879A1 - Circuit breaker comprising a passively heated bimetal element acting on a striking armature of an electromagnetic tripping device

Info

Publication number: EP3221879A1
Application number: EP15797318.1A
Authority: EP
Inventors: Matthias KATZENSTEINER
Original assignee: Eaton Industries Austria GmbH
Current assignee: Eaton Intelligent Power Ltd
Priority date: 2014-11-20
Filing date: 2015-11-18
Publication date: 2017-09-27
Anticipated expiration: 2035-11-18
Also published as: WO2016079206A1; CN107004546A; CN107004546B; DE102014117034A1; EP3221879B1

Abstract

Disclosed is a circuit breaker comprising at least two terminal contacts which are electrically connected within the circuit breaker via a switching contact (1). The circuit breaker further comprises an electromagnetic tripping device (2) which acts on the switching contact (1) and the coil (3) of which is connected between the at least two terminal contacts, and a bimetal element (4) acting on the switching contact (1). In said circuit breaker, the electrical connection between the at least two terminal contacts bypasses the bimetal element (4), and the bimetal element is thermally coupled to the electromagnetic tripping device (2). Furthermore, the electromagnetic tripping device (2) comprises a movably mounted striking armature or tappet (25) which is affected directly or indirectly by the bimetal element (4).

Description

Circuit breaker with passively heated and acting on a percussion anchor of an electromagnetic release bimetallic element

TECHNICAL AREA

The invention relates to a circuit breaker comprising at least two terminal contacts, which within the circuit breaker via a

Switching contact are electrically connected, acting on the switching contact electromagnetic release whose coil between the at least two

Connection contacts is connected, and acting on the switching contact bimetallic actuator respectively acting on the switching contact bimetallic element.

PRIOR ART Circuit breakers (short "LS-switch" or English, "circuit breaker") are used to protect a line against excessive current load. Becomes a

predetermined limit is exceeded, the between the

Connection contacts lying switching contact open and thus the circuit is interrupted. The tripping in conventional circuit breakers can usually be done electromagnetically, by means of a bimetallic element, manually and in many cases also via an external connection.

The electromagnetic release is aimed primarily at the disconnection of the circuit at high overcurrent. Because the coil of the electromagnetic release of the circuit breaker is flowed through by the current, which also on the

Contacts flows, the force generated by the electromagnetic release is dependent on the current. Above a certain threshold, the switching contact is opened by this force. The electromagnetic release responds very quickly, whereby the delay time between the occurrence of an overcurrent and the opening of the switch contact is only very short. The triggering via the bimetallic element (usually in strip form) takes place much slower and is intended above all to prevent excessively long-lasting current, which is only slightly above a set limit. The bimetallic element is for this purpose in the electrical connection between the

Connected terminal contacts of the circuit breaker and is therefore flowed through by the current flowing through the terminal contacts current. In this case, the bimetallic element is gradually heated according to its electrical resistance and switches off after a delay time, which depends on the magnitude of the current. A higher overcurrent leads to an earlier shutdown, a lower current to a later shutdown.

In general, the electromagnetic release or the bimetallic element can act directly or indirectly on the switching contact. In the latter case, the electromagnetic release / the bimetallic element may in particular act on a lever system connected to the switching contact. A disadvantage of known circuit breakers that the bimetallic element by the sometimes very high on the terminals of the

Line circuit breaker flowing currents is charged. Furthermore, the structure of a circuit breaker is complex due to the many items. Finally caused by the bimetallic element current, which also as

Ohmic resistance acts, a considerable power loss and thus leads to a poor efficiency of the circuit breaker.

DISCLOSURE OF THE INVENTION

An object of the invention is therefore to provide an improved circuit breaker. In particular, a current load of the bimetallic element should be reduced or avoided and / or falling on the circuit breaker

Power loss can be reduced and / or the structure of a circuit breaker can be simplified.

This object is achieved by a circuit breaker of the type mentioned, in which

- The electrical connection between the at least two terminals on the bimetallic element is passed over and the bimetallic element with said electromagnetic actuator is thermally coupled and

the electromagnetic release comprises a movably mounted impact anchor respectively plunger and the bimetallic element acts directly or indirectly on this impact anchor / plunger. In this way, the bimetallic element is passively heated, that is, heated only by the waste heat of the electromagnetic release. As a result, the power loss at the circuit breaker can also be reduced. In addition, the thermal and electromagnetic short-circuit release are combined spatially and functionally, ie they can form an assembly. This simplifies the construction of a circuit breaker.

In addition, the disclosed arrangement is particularly suitable for use in existing systems. The switching contact or the lever system do not need to be changed, since the bimetallic element acts indirectly via the plunger on the switching contact / the lever system. From the perspective of

Switching contact / lever system changes when using such

Trigger mechanism nothing.

Typically, the thermal trip unit of a circuit breaker (i.e., the bimetallic element) tends to be largely independent of the prior art

Ambient temperature. Therefore, one chooses the "working temperature", ie the temperature at which the curvature of the bimetallic element is so large that the switching contact is opened, comparatively high (eg above 100 ° C) .. In addition, the bimetallic element should have a sufficient working capacity for the This means that the product of travel and force at the free end of the bimetallic element should be sufficiently large, for which there is sufficient distance between the working temperature and the circuit breaker

Reference temperature (e.g., 20 ° C) necessary.

In the coil of a magnetic release of a circuit breaker is in

Overload range is usually given a temperature that is sufficient as the working temperature for the bimetal. Furthermore, the heating power of said electromagnetic release is sufficient in most cases to the bimetallic To heat element and ensure safe triggering of the circuit breaker by the bimetallic element.

Furthermore, the following circumstance is advantageous for the said operating principle:

Coils for large rated currents have a low number of turns at large

Conductor cross section, whereas coils for small rated currents have a comparatively large number of turns with a small conductor cross-section. As a result, essentially the same magnetic forces are achieved over a large nominal current range on the order of magnitude. Accordingly, also in heat

converted output equal in magnitude. Further advantageous embodiments and modifications of the invention will become apparent from the dependent claims and from the description in conjunction with the figures.

It is also favorable if the bimetallic element spaced from the

electromagnetic release, in particular spaced from the coil, is arranged. Thereby, a good electrical insulation between the electromagnetic release, in particular its coil, and the bimetallic element can be achieved. A short circuit of the coil by the bimetallic element is thus avoided even if the insulation of the coil should be defective for some reason.

In a preferred variant of the circuit breaker, the bimetallic element and the electromagnetic release, in particular its coil, are arranged directly adjacent in the circuit breaker. In this way, the bimetallic element can be well heated by thermal radiation. "Direct

neighboring "means in this context that between the

electromagnetic trigger, in particular its coil, and the bimetallic element in the relevant for the heat transfer by radiation zone no significant shielding by other components. Preferably, at least 90% of the radiation emitted by the electromagnetic release, in particular its coil, in this zone rays should impinge unhindered on the bimetallic element. This is 90% of the rays emitted by the electromagnetic release and due to the spatial position of the electromagnetic release and the bimetal element can meet each other in principle to the bimetallic element.

It is particularly advantageous if the bimetallic element is / are provided with a coating at least in the region of the thermal coupling with the electromagnetic release and / or the electromagnetic release at least in the region of the thermal coupling with the bimetal element, which is at least 90%. the infrared radiation absorbs. In this way, the heat transfer from the electromagnetic release to the bimetallic element succeeds particularly well. The bimetallic element and / or the electromagnetic release may be coated accordingly for this purpose. For a good heat transfer, the absorption capacity in the infrared range is relevant, in the visible wavelength range, the elements mentioned may well have a different color than black.

It is favorable if the bimetallic element is arranged above the electromagnetic release, in particular above the coil, or one

Guiding device for directing hot air from the electromagnetic release is provided on the bimetallic element. In this way, the bimetallic element can be well heated by convection. Warm air rising from the electromagnetic release sweeps around the bimetallic element and heats it. It is particularly advantageous in this case if a turbulent flow is generated, in particular by the shape of the electromagnetic release, its coil or the guide device.

In a particularly preferred embodiment of the circuit breaker, the bimetallic element forms at least part of a yoke of the electromagnetic release. On the one hand, the bimetallic element can in turn be heated by eddy currents, on the other hand, it forms part of the magnetic yoke of the electromagnetic release, resulting in a particularly strong synergistic effect. This variant of the invention works particularly well when the bimetallic element has a comparatively high iron content. In general, eddy currents at a frequency of 50 Hz contribute only a comparatively small proportion to heating of the bimetallic element. In a series of multiple circuit breakers, it is also advantageous if the coils are made of different thickness wire and have substantially the same diameter, in particular outer diameter. As a result, a series of circuit breakers with relatively few different types of its components can be constructed, since all coils have the same diameter (preferably the same outer diameter) and the components of the circuit breaker without larger

Adaptations to each other fit. Ideally, no need at all

be provided in different designs of the components of the circuit breaker. In an advantageous variant, the differently thick coil wires are also wound on bobbin tubes with different diameters, so that within the series of circuit breakers result in coils with substantially the same outer diameter.

It is favorable in a series of several circuit breakers, finally, if the distance between the bimetallic element and the electromagnetic release, in particular its coil, is substantially equal in several circuit breakers. In this way it is achieved that the

Heat transfer from the electromagnetic actuator to the bimetallic element within a series of circuit breakers having different thicknesses of coil wire is substantially the same.

It is also advantageous if the circuit breaker a transversely to

Movement direction of the impact armature / plunger arranged and on the

Impact armature / plunger-acting leaf spring comprises, which is fixedly mounted at one end to the electromagnetic release and connected at the other end to the bimetallic element, in particular articulated and / or

connected.

It is advantageous if the leaf spring acts on that end of the impact armature / plunger that faces away from the switching contact or the lever system. As a result, the interface between the impact armature / plunger and the switching contact or the lever system can be kept simple. In addition, such an arrangement can also be used for existing systems, since the said interface does not need to be changed. It is also beneficial if the leaf spring rests on the impact armature / plunger only. This results in a simple construction of the circuit breaker.

In addition, it is favorable if the leaf spring is connected / hooked to the impact armature / plunger. As a result, both tensile and compressive forces can be transmitted between the leaf spring and the impact armature / plunger.

It is advantageous if the leaf spring / bimetallic element has forked ends into which a notch in the bimetallic element / in the leaf spring engages. As a result, a rotary joint between the leaf spring and the bimetallic element can be realized in a simple manner. It is also advantageous if the leaf spring / the plunger has a recess into which engages a notch in the plunger / in the leaf spring. As a result, a rotary joint between the leaf spring and the plunger can be realized in a simple manner.

It is advantageous if the bimetal element when heated from

electromagnetic trigger bends away. In combination with a leaf spring results in degressive course of the force acting on the plunger force. Likewise, this results in a progressive course of the distance traveled by the plunger path relative to the path, which is covered by the free end of the bimetal element.

But it is also advantageous if the bimetallic element bends when heated to the electromagnetic release. This allows the bimetal element to press directly on the plunger of the electromagnetic release. In combination with a leaf spring also results in a progressive course of the force acting on the plunger force. Likewise, this results in a degressive course of the distance traveled by the plunger path relative to the path, which is covered by the free end of the bimetal element.

It is advantageous if a compression spring acts on the impact armature / plunger whose force is directed away from the switching contact or the lever system. As a result, the impact armature / plunger is pulled away from the switching contact or the lever system, regardless of the leaf spring. This variant is in particular advantageous if the leaf spring rests only on the impact armature / plunger but not connected / hooked with this.

It is also particularly advantageous if the bimetal element acts indirectly on the iron contact or iron yoke of the electromagnetic release on the switching contact. As a result, repercussions on the bimetallic element, where they can occur when the bimetallic element acts on the plunger of the electromagnetic release, can be reduced, since influence on the electromagnetic release is also taken via the iron circuit or iron yoke. It is advantageous in this context, if the at least one bimetallic element is inserted into an iron or iron yoke of the electromagnetic release such that a magnetic flux through the iron / iron yoke in a first position of the at least one bimetallic element at a first temperature smaller is the magnetic flux through the iron circle / iron yoke in a second position of the at least one bimetallic element at a second temperature. Advantageously, so can the

magnetic flux in the iron circle or iron yoke and thus the generated electromagnetic force on a plunger of the electromagnetic

Trigger be influenced. Thus, the bimetallic influence indirectly influences the switching contact via the electromagnetic release. Advantageously, the force that must apply the bimetal element, very low, since this acts essentially as a switch. The bimetallic element can therefore be kept very small.

It is advantageous if the first temperature is less than the second

Temperature. As a result, the magnetic flux and thus the force acting on a plunger of the electromagnetic release force at the higher temperature are greater. An increase in the current thus always causes an increase of said force, regardless of whether this is done by the current through the coil of the electromagnetic release or by a change of the bimetallic element from the first to the second position due to the increased current. It is particularly advantageous if the circuit breaker comprises a variable in function of the temperature of the at least one bimetallic element air gap in the iron / iron yoke. As a result, the magnetic flux in the iron circle / iron yoke of the electromagnetic release can be relatively strongly influenced, since the magnetic resistance formed by the air gap depends linearly on the size of the air gap.

It is also favorable if exactly one air gap per bimetallic element in

Iron circle / iron back as a function of the temperature of said

Bimetallic element is changeable. This results in a comparatively simple construction of the electromagnetic release, since one end of the bimetal element can be fixedly connected to the iron circle / iron yoke.

But it is also favorable if exactly two air gaps per bimetallic element in

Iron circle / iron back as a function of the temperature of said

Bimetallic elements are changeable. In this way, the influence of the bimetallic element can be enhanced.

It is advantageous if an air gap existing at the first temperature is closed at the second temperature. In this way, the influence of the bimetal element on the iron circle / iron yoke of the electromagnetic release is particularly large. It is favorable if exactly one bimetal element is inserted into the iron circle / iron yoke. This results in a comparatively simple construction of the electromagnetic release.

But it is also favorable if exactly two bimetallic elements in the

Iron circle / iron yoke are inserted. With appropriate design, an emergency function of the electromagnetic release can be maintained even if a bimetallic element should fail for any reason.

It is also advantageous if the at least one bimetal element is arranged parallel to a direction of movement of a plunger of the electromagnetic release. This results in a particularly compact design of the

Circuit breaker. It is favorable finally, if the circuit breaker a between an inner leg of the iron / iron yoke and the coil of the

having electromagnetic release arranged plastic tube. With appropriate choice of the plastic, the friction between the plastic tube and the inner leg, in the plastic pipe in particular also

can be slidably mounted, kept low. In addition, the magnetic flux is concentrated on the said inner leg.

The above embodiments and developments of the invention can be combined in any manner. BRIEF DESCRIPTION OF THE FIGURES

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawing. It shows:

Fig. 1 shows a first example of a triggering mechanism of a

Circuit breaker and;

Fig. 2 shows a second example of a triggering mechanism of a

Circuit breaker with a larger cross-section of a coil wire;

Fig. 3 shows an example of a trigger mechanism in which a bimetallic element acts indirectly via a leaf spring on a plunger of an electromagnetic release;

FIG. 4 shows the arrangement shown in FIG. 3 in a triggering state; FIG.

Fig. 5 shows another example of a trigger mechanism in which a

Bimetallic element acts indirectly via a leaf spring on a plunger of an electromagnetic release; Fig. 6 is an exemplary leaf spring in plan view;

Fig. 7 shows an exemplary bimetallic element in plan view and Fig. 8 shows an example of a trigger mechanism in which a bimetallic element, the iron or iron yoke of a

Electromagnetic trigger influenced.

DETAILED DESCRIPTION OF THE INVENTION Fig. 1 shows a first example of a triggering mechanism of a

Circuit breaker. In general, a circuit breaker comprises at least two terminal contacts, which are electrically connected within the circuit breaker via a switching contact 1. Furthermore, the

Circuit breaker or its release mechanism on the

Switching contact 1 acting electromagnetic release 2, the coil 3 is connected between the at least two terminal contacts and acting on the switching contact 1 bimetallic element. 4

Specifically, the electromagnetic release 2 comprises not only the coil 3, a yoke 5 and a not visible in FIG. 1 because retracted impact anchor respectively plunger. The bimetallic element 4 is fixed to a bimetallic support 6 and can be adjusted in its position (in FIG. 1 vertically) by means of a screw 7 which is guided by a nut 8 fixed to the housing. The bimetallic support 6 is supported on the (in Fig. 1 only partially shown) housing 10 of the

Line circuit breaker 1 off, and is thus secured against rotation. In this way, the switching point or the triggering point of the bimetallic element 4 can be adjusted. Furthermore, the distance of the bimetallic element 4 to the electromagnetic release 2 can be adapted to coils 3 of different sizes. Although for different currents different sized wire cross sections of the coils 3 are required and the coils 3 may also have otherwise different dimensions, thereby

Circuit breaker for different currents to be constructed substantially the same.

The switching contact 1 comprises a fixed fixed contact 1 1 and a movable contact piece 12, which is also part of a lever system 13. The switching piece 12 is marked for reasons of clarity with small rings to better explain the function of the lever system 13 below to be able to. The lever system 13 further comprises a contact piece carrier 14, which is rotatably mounted about a housing-fixed axis 15 and with points

is marked. The switching piece 12 is rotatably mounted about the arranged on the contact piece carrier 14 axis 16. Furthermore, the lever system 13 comprises a pawl 17 which is rotatably mounted about an arranged on the contact piece carrier 14 axis 18 and is also marked with dots. In addition, the lever system 13 comprises a latch support 19, which is rotatably mounted about the axis 15 and is characterized by small crosses. Finally, the lever system 13 comprises a torsion spring 20, which presses the pawl 17 and the pawl support 19 against each other, and a tension spring 21, whose force acts on the contact piece 12.

In Fig. 1 are finally still connecting wires 22 and 23 are shown, which connect the electromagnetic release 2 and the contact piece 12 with the guided outwards terminal contacts of the circuit breaker.

In contrast, the electrical connection between the at least two

Connection contacts led to the bimetallic element 4 over. Last still Fig. 1 shows a bracket 24, which the pawl 17 with a lever of

Circuit breaker connects.

The function of the trigger mechanism shown in FIG. 1 is now as follows: In an ON position, the bimetallic element 4 is straight, so that the torsion spring 20 presses the pawl rest 19 on the pawl 17 and the pawl 17 with its extension in the Latch support 19 hooked. As a result, the contact piece carrier 14, the pawl 17 and the pawl support 19 can only be moved together, that is, rotated about the housing-fixed axis 15. The spring 21 pulls the switching piece 12 in a clockwise direction about the axis 16, whereby the switching contact 1 remains closed in the ON position. If the shift lever of the line switch is now moved into the exhibition, the bracket 24 pulls the contact piece carrier 14, the pawl 17 and the pawl rest 19, which are hooked into one another, counterclockwise and thus causes the axis 16 to be moved to the right which is opened as a result of the switching contact 1. As another possibility, the tripping of the circuit breaker can be effected by the electromagnetic release 2. If the current is too high, the impact armature presses on the latch support 19, so that the locking between the pawl 17 and the latch support 19 is released. The latch support 19 and the pawl 17 are then in the position shown in Fig. 1. By the tension spring 21 of the contact piece carrier 14 is now rotated about the axis 15 in the counterclockwise direction, wherein the pawl 17 deviates upward and thereby performs a clockwise rotation. As a result, the arranged on the contact piece carrier 14 axis 16 moves to the right, whereby the switching contact 1 is opened. In a similar manner, the triggering of the circuit breaker by means of the bimetallic element 4. This presses on strong heating on a projection of the pawl support 19, which in turn around the axis 15 against the

Turned clockwise and thus the lock between the pawl 17 and the pawl support 19 is released. This situation is shown in FIG. The further movement sequence is completely analogous to that which is carried out when triggered by the electromagnetic release.

The triggering by the electromagnetic release 2 and the bimetallic element 4 are thus essentially the same effect. Only the attack points, the

Directions and, where appropriate, the size of the forces applied by the electromagnetic release 2 and the bimetallic element 4 forces on the pawl 19 are different. In both cases, however, a rotation of the pawl support 19 about the axis 15 is effected counterclockwise.

Due to the arrangement of the bimetallic element 4 in the immediate vicinity of

electromagnetic release 2, the bimetallic element 4 is heated by the waste heat of the electromagnetic release 2. The electromagnetic release 2, whose main function is the detection of short-circuit currents and the opening of the switching contact 1 in the event of overcurrent, thus simultaneously acts as a heating coil. This results in a double use of the electromagnetic release 2.

The tripping mechanism of the circuit breaker illustrated in FIG. 1 has the following further features: In the present example, the bimetallic element 4 is spaced from the

electromagnetic release 2, in particular spaced from the coil 3,

arranged. This allows a good electrical insulation between the

electromagnetic release 2, in particular its coil 3, and the bimetallic element 4 can be achieved. A short circuit of the coil 3 by the bimetallic element 4 is thus avoided even if the insulation of the coil 4 should be defective for some reason. However, the closer the bimetallic element 4 is disposed to the electromagnetic actuator 2, the better is the heat transfer from the electromagnetic actuator 2 to the bimetallic element 4.

Furthermore, the bimetal element 4 and the electromagnetic release 2, in particular its coil 3, are arranged directly adjacent in the circuit breaker. In this way, the bimetallic element 4 can be well heated by thermal radiation, because between the electromagnetic actuator 2, in particular its coil 3, and the bimetallic element 4 takes place in the relevant for the heat transfer by radiation zone no significant

Shielding by other components. Preferably, at least 90% of the radiation emitted by the electromagnetic release 2, in particular its coil 3, in the relevant transfer zone hits unhindered on the bimetallic element 4. In this context, it is advantageous if the bimetal element 4 is oriented such that the heat transfer takes place on the largest possible area.

It is advantageous in this context also if the bimetallic element 4 is provided with a coating at least in the region of the thermal coupling with the electromagnetic release 2 and / or the electromagnetic release 2, at least in the region of thermal coupling with the bimetallic element 4 / are, which absorbs at least 90% of the infrared radiation. In this way, the heat transfer by radiation from the electromagnetic release 2 to the bimetallic element 4 succeeds particularly well.

It is furthermore advantageous if the bimetallic element 4, as shown in FIG. 1, is arranged above the electromagnetic release 2, in particular above the coil 3. In this way, the bimetallic element 4 is not only by

Radiation but also by convection in the form of warm air from the electromagnetic actuator 2 rises and sweeps around the bimetallic element 4, heated. Alternatively or additionally, a guide device for directing hot air from the electromagnetic release 2 to the bimetallic element 4 may be provided. Although the variant of the triggering mechanism of a circuit breaker illustrated in FIG. 1 is advantageous, other embodiments are also conceivable. In general, it is possible between the bimetallic element 4 and the electromagnetic release 2, an intermediate element or a

Intermediate layer (e.g., teflon, glass silk). For example, the bimetallic element 4, the electromagnetic release 2, in particular the coil 3, also touch, whereby the bimetallic element 4 is well heated by heat conduction.

It is also advantageous if the bimetal element 4 forms at least part of the yoke 5 of the electromagnetic release 2. For example, the yoke 5 can be moved past the top of the coil 3. This will make the bimetallic element

4 on the one hand heated by eddy currents, on the other hand, it forms part of the yoke

5 of the electromagnetic release 2, resulting in a particularly strong synergistic effect. This variant of the invention works particularly well when the bimetal element 4 is a comparatively high

Has iron content. A layer of a bimetal element 4 is often made of magnetic steel anyway and can then simultaneously serve as part of the iron yoke or yoke 5 of the electromagnetic release 2. In this variant, the magnetic force on the bimetallic element 4 at

Short-circuit currents are taken into account, and also that eddy currents at a frequency of 50 Hz, a comparatively small proportion to heat the

Bimetallic element 4 contribute.

FIG. 2 now shows a variant of a triggering mechanism of a

Circuit breaker, which is very similar to the variant shown in FIG. In contrast, however, the coil 3 of the electromagnetic release 2 has a substantially larger cross-section than the coil 3 shown in FIG. 1 and is therefore suitable for a higher rated current. Moreover, that is

Bimetal element 4 in the front region bent down. In essence, that is Operation of the trigger mechanism shown in FIG. 2 but the same as for the trigger mechanism shown in FIG. 1.

It is advantageous if the coils 3 of several different

Circuit breaker of a series of circuit breakers as shown in Figures 1 and 2 substantially the same diameter (here

Inside diameter). This can be a series of

Circuit breakers are constructed with relatively few different types of its components. Ideally, no need at all

be provided in different designs of the components of the circuit breaker.

It is also advantageous if the distance between the bimetallic elements 4 and the electromagnetic release 2, in particular their coils 3, in several different circuit breakers a series of

Circuit breakers is substantially the same size, as shown in Figures 1 and 2. As a result, the heat transfer from the electromagnetic release 2 to the bimetallic element 4 within a series of

Circuit breakers with different thickness coil wire substantially the same.

In the illustrated in Figures 1 and 2 series of different

Circuit breakers, the coils 3 have substantially the same

Inside diameter. However, this is by no means mandatory. It would also be conceivable, for example, that the coils 3 are all essentially the same

Have outer diameter. This is the heat transfer from

electromagnetic release 2 on the bimetallic element 4 within a series of circuit breakers with different thickness coil wire even without adjusting the distance of the bimetallic element 4 by means of the screw 7 is substantially equal. For this purpose, the different thickness coil wires can be wound on bobbin tubes with different diameters, so that arise within the series of circuit breakers coil 3 with substantially the same outer diameter. Another way to adapt the trigger mechanism to different sized coils 3, is also given by the fact that an exchangeable transmission piece can be provided, via which the bimetallic element 4 on the

Latch support 19 attacks. Alternatively, a different length crank (see FIG. 2) may be provided for this purpose.

In the illustrated examples, the bimetallic element 4 curves towards the coil 3 when heated. However, the trigger mechanism can also be constructed so that the bimetallic element 4 bends away when heated from the coil 3.

For example, the bimetallic element 4 could be arranged in Figures 1 and 2 under the coil 3 and attack, for example, on a projection of the latch support 19. Advantageously, the bimetal element 4 is in its (unheated) initial position very close to the coil 3. Bends the bimetallic element 4 when heated then down, the latch support 19 against the

Moves clockwise, whereby the trigger mechanism is triggered in the manner already described above.

The bimetallic element 4 can, as shown in Figures 1 and 2, actively apply a thermoelastic force for unlatching a trigger mechanism. Alternatively, it would also be possible that the bimetal element 4 is biased and holds the trigger mechanism in the ON state. If this force returns when the bimetallic element 4 is heated, the triggering mechanism is triggered, that is, the switching contact 1 is disconnected.

Figures 3 and 4 now show an embodiment of a trigger mechanism of a circuit breaker, in which the bimetallic element 4 acts indirectly via the electromagnetic release 2 on the switching contact 1 respectively on a lever system connected to the switching contact. In Figures 3 and 4, only the electromagnetic release 2 including the bimetallic element 4 acting thereon and the fixed contact 1 1 is shown. However, the lever system with the switching piece, which may be configured as that shown in Figures 1 and 2, is not shown. Specifically, the electromagnetic release 2 comprises a movably mounted

Impact anchor 25 respectively plunger on the bimetallic element 4 indirectly via a transverse to the direction of movement of the impact armature / plunger 25 arranged leaf spring 26 acts. The leaf spring 26 is fixedly mounted at one end to the electromagnetic release 2 and at the other end with the bimetallic element 4th

connected. In particular, the leaf spring 26 is at one end via a fixed

Swivel mounted and hinged at the other end connected to the bimetallic element 4.

Furthermore, the electromagnetic release 2 comprises a first and second sleeve 27 and 28 of the magnetic circuit, which are made in particular of ferromagnetic material. The preferably made of plastic impact armature / plunger 25 is slidably mounted in the first sleeve 27 and is by means of a compression spring 29 in the direction of the leaf spring 26 and thus independent of the leaf spring 26 of

Pulled lever system away. The impact anchor / plunger 25 is further mounted in the second sleeve 28, which in turn is slidably mounted in the sleeve 30, which is preferably made of plastic. Furthermore, the electromagnetic release 2 comprises a fastening screw 31 for fastening the bimetallic element 4.

The operation of the triggering mechanism shown in Figs. 3 and 4 is now as follows, with Fig. 3 showing the triggering mechanism in an idle state, Fig. 4 in the tripped state:

In the state shown in FIG. 3, the current conducted via the circuit breaker is within the permissible range, so that the impact armature / plunger 25 is retracted by the compression spring 29. Now rise above the

Circuit breaker and thus on the coil 3 guided current, so on the one hand, the two sleeves 27 and 28 are attracted by the electromagnetic force, on the other hand, the bimetallic element 4 is heated and bends visibly outward. Increases the current (in a short time) on the tripping value, the two sleeves 27 and 28 are pulled so strong against the force of the compression spring 29 by the electromagnetic force that the

Impact armature / plunger 25 triggers the lever system, not shown, and thus the switching contact is disconnected. Supporting acts thereby, that the air gap between the two sleeves 27 and 28 thereby becoming ever narrower and thus the magnetic flux or the electromagnetic force are getting bigger. But the current through the coil 3 also leads to a heating of the bimetallic element 4, which bends against the force of the leaf spring 26 and against the force of the compression spring 29 to the outside. Characterized the leaf spring 26 is pulled into a more or less elongated shape and thus presses the impact armature / plunger 25 against the lever system, not shown. Also in this case, the ever narrowing air gap between the two sleeves 27 and 28 leads to an increase in the electromagnetic force.

The triggering of the circuit breaker thus depends both on the temperature of the bimetallic element 4 and the current through the coil 3. The temperature of the bimetallic element 4 represents a temporal integral of the current through the coil 3, so that the influence of the bimetallic element 4 predominates in currents which are indeed long-lasting but only slightly above a permissible value. However, if the current rises very rapidly and very far above a permissible value, then the influence of the electromagnetic force on the impact armature / plunger 25 prevails.

In general, the arrangement shown in Figures 3 and 4 still has the following features: The leaf spring 26 acts in this example on that end of the

Schlagankers / plunger 25, the switching contact 1 and the

Lever system 13 is turned away. This allows the interface between the

Impact armature / plunger 25 and the switch contact 1 and the lever system 13 are kept simple. In addition, such an arrangement can also be used for existing systems, since the said interface does not need to be changed.

Furthermore, the leaf spring 16 is only on the impact armature / plunger 25, resulting in a simple construction of the circuit breaker. Advantageously, the leaf spring 26 may also have fork-shaped ends, in which a notch in the bimetallic element 4 engages (see also Fig. 6 and 7). This can easily pivot between the leaf spring 26 and the

Bimetallic element 4 can be realized. Of course, it is also conceivable for the same purpose that the bimetallic element 4 has fork-shaped ends, in which a notch in the leaf spring 26 engages. In this example, the bimetal element 4 bends when heated to the electromagnetic release 2 out. The combination with the leaf spring 26 results in a progressive course of the force acting on the plunger 25 force. Likewise, this results in a degressive course of the distance traveled by the plunger 25 path relative to the path, which is covered by the free end (or by the force acting on the leaf spring 26 end) of the bimetal element 4.

FIG. 5 now shows an embodiment which is similar to the embodiment shown in FIGS. 3 and 4. However, now the bimetallic element 4 is bent upwards in the initial state (shown in solid lines) and bends downwards when heated (drawn in broken lines). Accordingly, the leaf spring 26 is curved upon heating of the bimetallic element 4 forward and pushes the

Impact armature / plunger 25 in the direction of only schematically shown

Lever system 13. In this example, the impact armature / plunger 25 is pulled away from the lever system 13 at low current solely by the leaf spring 26 until the impact armature / plunger 25 rests on a housing wall 10. Another spring is not provided, the use of which is not excluded. The impact anchor / plunger 25 is mounted in the front region in the yoke 5, in the rear part in the plastic sleeve 30. In addition, the illustrated arrangement further comprises an insulation 32. The function of the triggering mechanism shown in FIG. 5 is similar to that of FIG

Operation of the arrangement shown in Figures 3 and 4. Again, the triggering of the circuit breaker depends both on the temperature of the bimetallic element 4 and the current through the coil 3. The temperature of the bimetallic element 4 again represents a time integral of the current through the coil 3, which is why the influence of the bimetallic element 4 predominates in currents which, although long-lasting but only slightly above a permissible value. However, if the current increases very rapidly and very much above a permissible value, then the influence of the electromagnetic force on the impact armature / plunger 25 prevails, which pulls it in the direction of the yoke 5 or in the direction of the lever system 13.

Fig. 6 shows the leaf spring 26, Fig. 7, the bimetallic element 4 now in detail in plan view. Good to see are the recesses with which the two parts be hooked into each other. In this case, the fork-like extensions of the leaf spring 26 engage in the notches of the bimetallic element 4, whereby a kind of articulated connection is formed. Similarly, the leaf spring 26 is mounted in the lower region in the yoke 5. Of course, it is also conceivable for the same purpose that the bimetal element 4 has fork-shaped ends, in which a notch in the leaf spring 26 engages. Of course, the arrangement shown is not only applicable to the triggering mechanism shown in Fig. 5, but can also be applied to the triggering mechanism shown in Figs. 3 and 4.

In general, the arrangement shown in FIG. 5 still has the following features: In this example, the leaf spring 26 again acts on that end of the

Schlagankers / plunger 25, the switching contact 1 and the

Lever system 13 is turned away. This allows the interface between the

Impact armature / plunger 24 and the switch contact 1 and the lever system 13 in turn kept simple or even used for existing systems.

In this example, the leaf spring 26 is also connected / hooked to the impact armature / plunger 25. As a result, both tensile and compressive forces between the leaf spring 26 and the impact armature / plunger 25 can be transmitted.

In the embodiment variant shown in FIG. 5, the bimetallic element 4 moreover bends towards the electromagnetic release 2 upon heating. By combining with the leaf spring 26, this results in a progressive course of the force acting on the plunger 25 force. Likewise, this results in a degressive course of the distance traveled by the plunger 25 way relative to the path of the free end (or of the force acting on the leaf spring 26 end) of the

Bimetallic element 4 is covered.

8 shows a further example of a triggering mechanism in which the bimetallic element 4 acts indirectly via the electromagnetic release 2 on a switching contact or on a lever system connected to the switching contact (shown here only symbolically) of the circuit breaker. In contrast to the variants shown above, but now two bimetallic elements 4 are in such an iron or iron yoke 5 of the electromagnetic Trigger 2 inserted that a magnetic flux through the

Iron circle / iron yoke in a first position (shown in solid line) of the at least one bimetallic element 4 at a first temperature is less than the magnetic flux through the iron circle / iron yoke in a second position (dashed line) of the at least one bimetallic element 4 at a second temperature.

Specifically, the electromagnetic release 2 comprises, in addition to a coil 3 and a centrally arranged and preferably made of plastic sleeve 30 two sleeves 27 and 28, a front disc 33 and a rear disc 24 which form parts of the iron / iron yoke. In addition, the bimetal elements form 4 parts of the iron circle / iron yoke.

In the present example exactly two bimetallic elements 4 in the

Iron circle / iron yoke inserted. It would also be conceivable that only one bimetallic element 4 or more bimetallic elements 4 in the

Iron circle / iron back is inserted / are. The bimetallic elements 4 are in this example parallel to a direction of movement of the plunger 15 of the

electromagnetic release 2 arranged. This results in a particularly compact design of the circuit breaker.

The function of the triggering mechanism shown in Fig. 8 is now as follows: In a rest state, the bimetallic elements 4 are more or less straight in this example, resulting in the iron / iron yoke air gaps, which adjoin the bimetal elements 4. With increasing

Heating the bimetal elements 4 curve towards the coil 3, whereby the air gaps are smaller. The illustrated electromagnetic release 2 thus has air gaps in the iron circle / iron yoke, which are variable as a function of the temperature of the bimetallic element 4. From a certain temperature, the bimetallic elements 4 are so strongly curved that the air gaps are closed.

Advantageously, the magnetic flux in the iron or

Iron yoke and thus the generated electromagnetic force to a plunger 25 of the electromagnetic release 2 can be influenced. Thus, the bimetal element 4 indirectly via the electromagnetic release 2 influence The advantage of this arrangement is that the force that has to apply the bimetal element 4, is very low, since this acts essentially as a switch. The bimetallic elements 4 can therefore be kept very small. In the present example exactly two air gaps per bimetallic element 4 are in

Iron circuit / iron yoke provided, which are variable depending on the temperature of said bimetallic element 4. It would also be conceivable that exactly one air gap per bimetallic element 4 in the iron circle / iron yoke is variable as a function of the temperature of said bimetallic element 4. For example, one end each of a bimetal element 4 could be fixedly connected to the disk 33 or the disk 34.

By a current through the coil 3, an electromagnetic force is generated on the sleeve 28 and thus on the plunger 25, which pulls them against the force of the compression spring 29 in the direction of the lever system 13. Due to the constantly narrowing air gap, the electromagnetic force is also getting bigger. The magnetic flux and thus the electromagnetic force are also influenced by the air gaps, which adjoin the bimetal elements 4. For smaller air gaps are also the magnetic flux and thus the

electromagnetic force larger, with larger air gaps accordingly smaller. Therefore, the temperature of the bimetallic elements 4 also influences the force acting on the impact armature / plunger 25.

Even with the trigger mechanism shown in Fig. 8, the triggering of the circuit breaker thus depends both on the temperature of the bimetallic element 4 and the current through the coil 3. The temperature of the bimetallic element 4 in turn represents a time integral of the current through the coil 3, which is why the influence of the bimetallic element 4 predominates in currents which are indeed long-lasting but only slightly above a permissible value. However, if the current increases very rapidly and very much above a permissible value, then the influence of the electromagnetic force on the impact armature / plunger 25 prevails, which pulls it in the direction of the yoke 5 or in the direction of the lever system 13. Preferably, the first temperature, which is associated with a larger air gap, is smaller than the second temperature, which is a smaller air gap

assigned. As a result, the magnetic flux and, as a result, the force acting on the plunger 4 of the electromagnetic actuator 2 are greater at the higher temperature. An increase in the current thus always causes an increase in said force, regardless of whether this is due to the current through the coil 3 of the electromagnetic release 2 or by a change of the bimetallic element 4 from the first to the second position due to the increased current.

In general, triggering mechanisms are suitable in which the bimetallic element 4 acts indirectly via the electromagnetic release 2 on a switching contact or on a lever system 13 of the circuit breaker connected to the switching contact (see in particular FIGS. 3 to 8), especially for use in existing systems , The lever system 13 does not need to be changed, since the bimetallic element 4, as shown above, acts indirectly on the lever system 13 via the plunger 4. From the perspective of the lever system 13, nothing changes with the use of such a triggering mechanism.

It should also be noted that the triggering mechanisms shown in FIGS. 1 and 2 are mutatis mutandis applicable to the triggering mechanisms shown in FIGS. 3 to 8. For example, the bimetallic element 4 may be arranged at a distance from the electromagnetic release 2. The bimetallic element 4 and the electromagnetic release 2 can also be arranged directly adjacent in the circuit breaker. In addition, it is conceivable that the bimetal element 4 is at least in the thermal coupling with the electromagnetic release 2 and / or the electromagnetic release 2 at least in the thermal coupling with the bimetallic element 4 is provided with a coating / which at least 90% of the infrared radiation absorbed. It is also possible that the bimetallic element 4 above the

electromagnetic initiator 2 is arranged or a guide device for conducting hot air from the electromagnetic release 2 is provided on the bimetallic element 4. In the variants shown in FIGS. 3 to 5, it is also conceivable that the bimetallic element 4 forms part of the yoke 5 of the electromagnetic release 2. Finally, it is also possible with the embodiments shown in Figures 3 to 8, a series of multiple circuit breakers to form, in which the coils 3 are made of different thickness wire and substantially the same diameter, in particular outer diameter, have (compare Figures 1 and 2). In particular, the distance between the bimetallic element 4 and the electromagnetic release 2 in the case of several circuit breakers may be substantially the same.

Finally, it is noted that the triggering device is not necessarily shown to scale and therefore may have other proportions. Furthermore, the triggering device may also comprise more or fewer components than shown. Location information (for example, "top", "bottom", "left", "right", etc.) are based on the respective figure described in each case and are to be adapted in a position change in accordance with the new situation. For example, the

electromechanical release 2 and the bimetallic element 4 instead of horizontally and vertically aligned as shown. Finally, it is noted that the above refinements and developments of the invention can be combined in any desired manner.

Claims

claims

1 . Circuit breaker comprising

at least two connection contacts, which are electrically connected within the circuit breaker via a switching contact (1),

an electromagnetic release (2) acting on the switching contact (1) or on a lever system (13) connected to the switching contact (1), whose coil (3) is connected between the at least two connecting contacts and

at least one bimetallic element (4) acting on the switching contact (1) or on a lever system (13) connected to the switching contact (1),

wherein the electrical connection between the at least two

Connection contacts on the bimetallic element (4) is passed over and the bimetallic element (4) with said electromagnetic release (2) is thermally coupled and

- The electromagnetic release (2) has a movably mounted

Impact armature or plunger (25) and the bimetallic element (4) acts directly or indirectly on this impact armature or plunger (25) and

wherein the circuit breaker a transverse to the direction of movement of

Impact armature or plunger (25) arranged and on the impact armature or plunger (25) acting leaf spring (26) which at one end against the electromagnetic release (2) fixedly mounted and at the other end with the

Bimetallic element (4) is connected.

2. Circuit breaker according to claim 1, characterized in that the leaf spring (26) acts on that end of the impact armature / plunger (25) that the

Switching contact (1) or the lever system (13) facing away.

3. circuit breaker according to claim 2, characterized in that the leaf spring (26) on the impact armature or plunger (25) only rests.

4. Circuit breaker according to one of claims 1 to 3, characterized in that the leaf spring (26) with the impact armature or plunger (25) is connected or hooked.

5. Circuit breaker according to one of claims 1 to 4, characterized in that the leaf spring (26) or the bimetallic element (4) has fork-shaped ends, in which a notch in the bimetallic element (4) or in the leaf spring (26) intervenes.

6. Circuit breaker according to one of claims 1 to 5, characterized in that the leaf spring (26) or the plunger (25) has a recess into which a notch in the plunger (25) or in the leaf spring (26) engages.

7. Circuit breaker according to one of claims 1 to 6, characterized in that the bimetallic element (4) when heated from

electromagnetic actuator (2) bends away.

8. Circuit breaker according to one of claims 1 to 6, characterized in that the bimetallic element (4) when heated to

electromagnetic trigger (2) bends.

9. Circuit breaker according to one of claims 1 to 8, characterized in that on the impact armature or plunger (25) acts a compression spring, the force of the switching contact (1) or the lever system (13) is directed away.