CN103681133B - The protection switch equipment of switching mechanism and electromechanics - Google Patents

Abstract

Switchgear and electromechanical protective switchgear. The switching mechanism has a switch contact, which has a fixed contact fixedly arranged in the housing of the protective switchgear and a movable contact support which is fixedly mounted on a movably supported movable contact and can move relative to the fixed contact and can Movable contacts that move together with the movable contact support. The switching mechanism has a movably mounted tripping lever which, when a predefined tripping criterion occurs, acts on the movable contact carrier in order to bring about the opening of the switching contacts. In this case, a first contour is formed on the tripping lever, which acts on a first partial surface of the movable contact carrier during the first phase of opening of the switching contact. A second profile is formed on the trip bar, which acts on the second partial surface of the movable contact support during the second phase of opening of the switch contact, said profiles being offset from each other so that during the first phase the An increased impact pulse lever is achieved and an increased impact opening distance can be achieved in the second stage.

Description

Switchgear and electromechanical protective switchgear

technical field

The invention relates to a switching mechanism for an electromechanical protective switching device, the switching mechanism having a switching contact with a fixed contact arranged fixedly in the housing of the protective switching device and capable of opposing A movable contact that moves with the fixed contact, is fixedly installed on a movable contact support that is supported in a rotatable manner, and can move together with the movable contact support. Furthermore, the protective switching device has a movably mounted tripping lever which acts on the movable contact carrier when a predefined tripping criterion occurs, such as an electrical short circuit or an overload current, used to cause the opening of the switch contacts. Among other things, the invention relates to an electromechanical protective switching device having such a switching mechanism.

Background technique

Protective switching devices, such as circuit breakers or circuit breakers, are used in particular as switches and safety elements in power supply networks. Circuit breakers are especially designed for higher currents. Circuit breakers are overcurrent protection devices in electrical installations and are used in particular in the field of low-voltage power grids. Circuit breakers and line protection switches ensure safe disconnection in the event of a short circuit and protect loads and equipment from overload. Circuit breakers and circuit breakers, for example, protect the lines from being damaged by excessive heating caused by too high currents and are designed to automatically switch off the monitored circuit in the event of a short circuit or in the event of an overload and thus disconnect it from the separated from the grid.

Such protective switching devices generally have a switching contact pair, which in turn has fixed switching contacts, or fixed contacts for short, and switching contacts, or movable contacts for short, which are movable relative to the fixed contacts. To conduct current, the movable switching contact contacts the fixed contact. In order to split the current, the movable contact is moved away from the fixed contact. The interruption of the current flow causes a voltage flashover between the fixed switching contact and the movable switching contact for each protective switching device at least briefly, since the distance between the switching contacts separates The process is not sufficient for isolation. If there is a gas between the two switching contacts, the gas is ionized by an electric arc when there is a correspondingly high voltage difference between the switching contacts, so that due to the discharge of the gas a arc.

DE 10 2004 040 288 B4 discloses a protective switch having a first tripping device for detecting and tripping a short circuit and a second tripping device for detecting and tripping an overload state. Furthermore, the protective switch has a switching contact with a fixed contact and a movable contact movable relative to the fixed contact, as well as a tripping lever, which is thus connected to the first tripping device and to the The second trip device is coupled such that the trip lever is actuated and the switch contacts are opened when the first trip device and/or the second trip device is tripped.

Therefore, the circuit breaker or circuit breaker is designed in such a way that the arc generated when the switching contacts are opened and thus interrupts the current flow. For this purpose, these protective switching devices have a time-delayed, eg magnetic, tripping system with a coil and an armature-tapster unit movable relative to the coil, via which the armature-tapster- The unit conducts the current to the switching contacts or also only a part of the current. When the current rises rapidly, such as in the event of a short circuit, the coil attracts the armature. Consequently, the tappet hits the trip lever, whereby the switching mechanism of the protective switching device is released and collapses. The current is finally interrupted by the switching contacts that are opened during this process. Therefore, non-delayed or fast-release tripping systems are used to prevent melting of the conductive contact surfaces at high current intensities and to ensure reliable switching off of the protective switchgear in the event of a resulting arc that could damage the protective switching device. Protective switchgear. Short tripping times are advantageous for this purpose, especially since the industrial range of use of the protective switch is greatly limited by too long tripping times.

In the event of a short circuit, the magnetic tripping system causes the switching contacts to open. For this purpose, the coil of the magnetic tripping system is energized with a short-circuit current, whereby the armature is pulled into the coil. The tappet connected to the armature is moved from the rest position into the release position. In order to open the switching contact, the tappet strikes the tripping lever, whereby the tripping lever is likewise moved. The switching mechanism of the protective switching device is released by the movement of the tripping lever, whereby the movable contact coupled to the switching mechanism moves away from the fixed contact. This means that in the event of a short-circuit the movement of the tappet is firstly transmitted to the tripping lever, which thus trips the switching mechanism, whereby the movable contact moves away from the fixed contact. head. In this way, a tripping chain consisting of tappets, tripping levers and movable contacts is thereby realized. A tripping mechanism with such a tripping chain is known, for example, from DE 10 2004 040288 B4.

However, since the drive chain of the switching mechanism reacts relatively sluggishly, short-circuit tripping systems are also used, which also act directly on the movable contact and cause it to leave the movable contact directly. Fixed contacts. The distance between the fixed contact and the movable contact which can be achieved here at the end of the operating time of the non-delayed release is referred to as the so-called impact-to-open distance or simply to impact-to-open. The impact opening is thus the contact distance between the fixed contact and the movable contact which can be achieved directly by a direct mechanical impact of the short-circuit tripping system on the movable contact in the event of a short-circuit tripping. The final complete opening of the contacts is then brought about by the switching mechanism coming to rest after it has tripped. A sufficiently large impact opening distance thus accelerates the arc run and its elimination process and thus has a decisive influence not only on the switching performance but also on the service life of the protective switching device.

Contents of the invention

It is therefore the object of the present invention to provide a switching mechanism and an electromechanical protective switching device which are distinguished by short tripping times and improved tripping behavior .

This object is achieved by a switching mechanism and an electromechanical protective switching device according to the independent claims. Advantageous refinements are the subject matter of the subclaims.

The switching mechanism according to the invention for an electromechanical protective switching device has a switching contact which itself has a fixed contact which is fixedly arranged in the housing of the protective switching device and which can be arranged relative to the fixed The movable contact of the contact is fixedly mounted on a movable contact carrier supported in a rotationally movable manner and is movable together with said movable contact carrier. In addition, the switching mechanism has a movably mounted tripping lever which, when a predefined tripping criterion occurs, acts on the movable contact carrier in order to cause a tripping of the switching contacts. Open. In this case, a first contour is formed on the tripping lever, which, in the first phase of opening of the switching contact, acts on a first partial surface of the movable contact carrier. Furthermore, a second contour is formed on the tripping lever, which in the second phase of opening of the switching contact acts on a second partial surface of the movable contact carrier, wherein the The first contour and the second contour are arranged offset relative to each other in such a way that in the first phase an increased impact pulse lever can be achieved and in the second phase an increased impact opening distance can be achieved .

The division of the active surface of the tripping bar into a first contour and a second contour and the division of the movable contact support cooperating with the tripping bar into a first partial surface and a second partial surface enables, over time, To separate the corresponding cooperating active surfaces of the trip lever or the movable contact carrier:

Firstly, in the first phase of opening of the switching contact, the first contour acts on the first partial surface in such a way that a pulse lever that is as large as possible can be achieved. The pulse lever here refers to the distance from the point of contact of the active surface to the point of rotation of the movable contact carrier. If such a pulse lever can be increased, the pulses that can be transmitted by the trip bar to the movable contact support are also larger, which causes a greater acceleration of the movable contact tip and thus the resulting Lightning-fast opening of the switching contacts, as a result of which the arc is picked up and thrown out of the contact area. With regard to the switching behavior or service life of the switching mechanism or protective switching device, it is particularly advantageous if the opening of the switching contacts is completed as quickly as possible and the arc leaves the contact region or the The contact area serves to keep the input of energy into the switching mechanism—and thus damage to the protective switching device—as small as possible.

In a further development, a second contour of the tripping bar acts on a second partial surface of the movable contact carrier in the second phase of opening of the switching contact, wherein the The second contour and the second partial surface thus achieve a static impact opening distance that is greater than when the first contour interacts with the first partial surface. The static strike-opening distance here means the contact distance between the fixed contact and the movable contact at the moment of opening the strike. As a result of the increase in the impact opening distance, a higher arc voltage of the arc is achieved and the running of the arc is accelerated, thereby significantly improving the switching performance and the service life of the switching mechanism.

In an advantageous development of the switching mechanism, the first contour and/or the second contour are designed as cams or cams protruding from the surface of the trip lever. . The cam or cam represents a simple means for realizing the first and/or second contour and thus - in cooperation with the first and/or second partial surface of the trip lever - Possibilities for realizing said two side effects.

In another advantageous development of the switching mechanism, the first contour and/or the second contour are connected to the tripping lever by welding or by means of soldering. Welding or soldering are used and common production methods with which the corresponding contours can be produced without major design and financial outlay. Furthermore, in this way, the static shock opening can be adjusted to a predetermined minimum dimension. In addition, the mentioned processing method offers the possibility of placing the variant definition time at the end of the processing process at a later time, so that a higher variant variety can be achieved at a relatively favorable variant cost. Features - such as trip levers with or without bumps/cams or with bumps/cams of different configurations.

In another advantageous development of the switching mechanism, the first contour and/or the second contour is integrally formed on the tripping lever. By selecting a suitable forming method, such as injection molding, the trip lever can be produced cost-effectively—in particular in a relatively high number of pieces.

In a further advantageous development, the switching mechanism has a locking pawl which is mechanically coupled to the movable contact carrier and rests on the movable contact carrier when the switching contact is closed. on the trip lever, thereby locking the switch mechanism. The locking can be released by moving the trip lever, whereby the movable contact carrier is brought into its end position in the third phase of opening of the switching contact. The locking of the switching mechanism—for example by the support of the locking pawl on the trip lever—represents a simple design possibility for the connection between the fixed contact and the movable contact. A high locking force is achieved between them, wherein the release of the locking causes the switching contacts to open, thereby bringing the movable contact carrier and thus the movable contact into their final position .

In a further advantageous development, the switching mechanism can be coupled mechanically to a movably mounted tappet of the short-circuit release of the electromechanical protective switching device in such a way that the In the event of a short circuit, the tappet acts mechanically on the tripping lever in order to bring about the opening of the switching contacts. A possible tripping criterion that causes tripping of the switching mechanism and thus of the protective switching device is the presence of a short circuit that is accompanied by a high short-circuit current. The use of a short-circuit release device necessary for this, which has a coil, represents a common possibility for detecting a short circuit and for correspondingly tripping the switching mechanism of the protective switching device. The coil then has a tappet mounted movably therein, which is actuated by the coil in the event of a short-circuit current in order to act mechanically on the tripping lever.

In a further advantageous refinement, the switching mechanism can be coupled mechanically to the overload release of the electromechanical protective switching device in such a way that the overload release mechanically switches off in the event of an overload current. acting on the trip lever in a manner for causing the opening of the switch contacts. Another tripping criterion that can cause tripping of the switching mechanism and thus of the protective switching device is the occurrence of an overload current, that is to say the occurrence of a ratio correlation within a relatively long predefined time interval. The rated current of the protective switchgear is high current. For this purpose, for example, a bimetal can be used, which heats up due to the overload current flowing for a longer period of time and thus deforms. This deformation can be transferred mechanically to the trip lever by means of suitable components. Through the use of an additional overload release, the range of use of the protective switchgear can be significantly expanded.

The electromechanical protective switching device according to the invention has a switching mechanism of the type described above and a short-circuit release, which is coupled to the switching mechanism in such a way that when the short-circuit release is tripped Buckling causes the opening of the switch contacts.

In an advantageous development, the protective switching device has an overload release device, which is coupled to the switching mechanism in such a way that when the overload release device trips, the switch contacts The opening of the head.

With regard to the advantages of the electromechanical protective switching device according to the invention, reference is made to the mentioned advantages of the switching mechanism according to the invention.

Description of drawings

An exemplary embodiment of the protective switching device according to the invention or of the switching mechanism according to the invention will be explained in more detail below with reference to the drawings. The accompanying drawings show the following:

1A to 1D are schematic illustrations of side views of the protective switching device according to the invention at various moments in the tripping process;

2A and 2B are schematic detailed illustrations of side views of the switching mechanism according to the invention at the beginning of pulse delivery; and

3A and 3B are schematic detailed illustrations of a side view of the switching mechanism according to the invention at the moment of static impact opening.

In the different figures, the same components are always provided with the same reference signs. The description applies to all figures in which corresponding parts can likewise be seen.

List of reference signs:

1 Protective switchgear

2 housing

3 riveted connection

4 Operating elements

10 switch mechanism

11 Fixed contacts

12 movable contacts

13 Movable contact support

13-1 Surface of the first part

13-2 Surface of the second part

14 Trip lever

14-1 First profile

14-2 Second profile

15 Locking pawl

16 supports

17 springs

18 Coupling elements

20 Short-circuit release device

21 Coils

22 armature

23 tappets

24 Core

25 Yoke

26 return spring

30 Overload release device

31 bimetallic

32 stranded wire

33 tension rod

D Rotation axis

H pulse lever

L air gap

S shocks open the pitch.

detailed description

In FIGS. 1A to 1D , the protective switching device 1 according to the invention is schematically shown correspondingly in side views at different points in time during the tripping process. The protective switch device 1 has a switching mechanism 10 provided with switching contacts consisting of a fixed contact 11 and a movable contact 12 which is movable relative to the fixed contact. The movable contact 12 is mounted on a movable contact carrier 13 , which is mounted in the housing 2 of the protective switchgear 1 in a rotationally movable manner by means of an axis of rotation D. As shown in FIG. The housing 2 is formed in the present case from at least two housing parts, which are fastened together by a plurality of riveted connections 3 . However, for reasons of clarity, only the part of the housing 2 arranged in the background is shown. For the manual actuation of the switching contacts, the protective switching device 1 has a manually actuatable actuating element 4 which is likewise mounted rotatably in the housing 2 . The actuating element 4 is coupled to the movable contact carrier 13 via a mechanical coupling element 18 (see FIG. 2A / FIG. 3A ), so that the switching contacts are opened and closed when the actuating element 4 is actuated. FIG. 1A shows the protective switching device 1 in its on position, in which the switching contacts are closed, that is to say the fixed contact 11 and the movable contact 12 are in direct contact with each other. between the contacts and thereby establish an electrically conductive contact.

FIG. 1B shows the protective switching device 1 with the short-circuit release 20 assigned to it at the start of the process of transmitting pulses to the movable contact carrier 13 . For this purpose, the short-circuit release 20 has a coil 21 via which the current to the switching contacts is conducted. In order to improve the magnetic effect of the coil, the short-circuit release 20 has a magnetic yoke 25 which is fixedly mounted in the housing 2 and a magnetic core 24 which is connected to the magnetic yoke 25 . In the case of a rapid current rise, for example due to a short circuit, the coil 21 attracts via the core 24 an armature-tappet unit mounted movably in the coil 21 , which armature-tapster- The unit consists of an armature 22 and a tappet 23 fixedly connected thereto.

In this case, the tappet 23 is moved from its rest position (shown in FIG. 1A ) into its release position shown in FIG. 1B . Returning to the rest position is carried out by means of a return spring 26 .

In the rest position of the tappet 23 shown in FIG. 1A , an air gap L is formed between the core 24 and the armature 22 . If the tappet is moved from its rest position into the tripped position, it hits the tripping lever 14 of the switching mechanism 10 . In the switched-on position ( FIG. 1A ) of the protective switching device 1 , that is to say when the switching contacts are closed, the switching mechanism 10 is supported by the locking pawl 15 on the upper end of the release lever 14 . superior. The movable contact carrier 13 is held in the position shown by the lug 16 connecting the locking pawl 15 to the movable contact carrier 13 , wherein the movable contact 12 is directed towards The fixed contact 11 is squeezed. At the start of the short-circuit tripping process (see FIG. 1B ), the tappet 23 now hits the tripping lever 14 , which then moves in a counterclockwise direction. As a result, the locking pawl 15 can no longer support the switching mechanism 10 on the upper end of the release lever 14 , and the locking is released. As a result of the movement of the locking pawl 15 , the movable contact carrier 13 is no longer supported by the support 16 and is brought into the position shown in FIG. 1D by the spring 17 . The movable contact 12 is moved away from the fixed contact 11 by the movable contact carrier 13 - the switching contact is opened.

The distance of the contact point of the tripping lever 14 with the movable contact carrier 13 relative to the point of rotation D of the movable contact carrier is referred to as a so-called impulse lever H here. The larger the size of the pulse lever is designed, the greater the angular momentum that can be transferred from the tappet 23 to the tripping rod 14 . The greater the angular momentum that can be transmitted to the trip lever 14, the greater the acceleration of the movable contact carrier 13 that can be achieved by impact opening, wherein a large acceleration causes a faster movement of the switching contacts. open.

FIG. 1C shows the protective switching device 1 at the end of the short-circuit tripping process, the so-called static surge opening. The tappet 23 is here in its tripped position, whereby the trip lever 14 is brought into the position shown by a counterclockwise rotation. This also releases the locking of the locking pawl 15 on the release lever 14 , wherein the remaining switching mechanism 10 has not yet reacted to the release of the locking due to its inertia. The so-called impact-to-open distance S denotes the distance of the movable contact 12 from the fixed contact 11 at the moment of impact-to-open, which should therefore not be attributed to the chain of action of the switching mechanism 10 , but should be attributed to the fact that the tappet 23 acts directly on the movable contact carrier 13 via a shock pulse via the lower end of the tripping bar 14 and has caused it to leave the Fixed contact 11.

FIG. 1D shows the third phase of the opening of the switching contact, in which the movable contact 12 is fully deflected away from the fixed contact 11 driven by the chain of action of the switching mechanism 10 , thereby achieving a maximum opening of the switching contact. In this third phase—likewise via the switching mechanism 10—the actuating element 4 is also brought into its deactivated position.

2A and 2B schematically show the process according to the invention at the start of the process of transmitting pulses from the tappet 13 via the tripping lever 14 to the movable contact carrier 13. switch mechanism 10. A side view of the switching mechanism 10 corresponding to the illustration in FIG. 1B is schematically shown in FIG. 2A , while FIG. 2B schematically shows the trip lever 14 together with the movable contact. A detailed illustration of the cooperation of the support 13 at the start of pulse delivery.

The tripping bar 14 has a first profile 14 - 1 and a second profile 14 - 2 in the area of contact with the movable contact support 13 . Likewise, the movable contact carrier 13 has a first partial surface 13 - 1 and a second partial surface 13 - 2 in the area of contact with the trip lever 14 . In the first phase of opening of the switching contact shown in FIGS. 2A and 2B , here only the first contour 14 - 1 of the tripping lever 14 acts on the movable contact carrier 13 . First part surface 13-1. In this case, the first contour 14 - 1 is formed onto the tripping lever 14 or is formed on the tripping lever 14 in such a way that the pulse lever H, ie the tripping lever 14 , is increased. The distance between the contact point with the movable contact support 13 relative to the rotation point D of the movable contact support 13 . As can be seen very well in the detailed illustration of FIG. 2B , the first contour 14 - 1 is arranged on the tripping lever 14 in such a way that the contact point—without the second A profile 14 - 1 of the trip bar 14 is shifted downwards in the illustration. A greater angular momentum can be transmitted to the movable contact carrier 13 by means of the larger impulse lever H thus achievable.

3A and 3B schematically show the switching mechanism 10 according to the invention at the moment of a static impact opening by the tappet 23 acting indirectly on the movable contact carrier 13 . In FIG. 3A, a side view of the switching mechanism 10 corresponding to the illustration in FIG. 1C is again schematically shown, while FIG. A detailed illustration of the interaction of the snap rod 14 and the movable contact support 13 .

In the second phase of the opening of the switching contact shown in FIGS. 3A and 3B , now only the second contour 14 - 2 of the tripping bar 14 acts on the movable contact carrier 13 . The second part surface 13-2. This second contour 14 - 2 is formed on the tripping lever 14 or formed on the tripping lever 14 in such a way that the impact opening distance S is increased, that is to say in the case of a static impact opening Time is the distance between the movable contact 12 and the fixed contact 11 . As can be seen very well in the detailed illustration of FIG. 3B , for this purpose the second profile 14 - 2 is arranged on the trip bar 14 in such a way that it is aligned with the second partial surface 13 - 2 The contact point of -compared to the trip lever 14 without the second profile 14 - 2 formed thereon -is shifted to the right in the illustration of FIG. 3B . By means of this measure, a larger impact opening distance S can be achieved. As a result, not only a higher arc voltage of the arc occurring between the fixed contact 11 and the movable contact 12 is achieved, but also the running of the arc is accelerated, thereby significantly improving the switching mechanism 10 and thus the resultant The switching performance and service life of the protective switching device 1 are described.

Claims (9)

1. electromechanical protection switch equipment is used for（1）Switching mechanism（10）, have

- switch contact, the switch contact have be fixedly placed on the protection switch equipment（1）Housing（2）In fixation Contact（11）And can be relative to the fixed contact（11）The movable contact of motion（12）, the movable contact（12）Regularly Installed in the movable contact bearing can be supported in the way of rotary motion（13）It is upper and can be with the movable contact Bearing（13）Move together；

- the release lever supported in the way of it can move（14）, the release lever is when there is pre-defined dropout standard Act on the movable contact bearing（13）, the opening for causing the switch contact,

Characterized in that,

- in the release lever（14）On construct the first profile（14-1）, the first profile（14-1）In the switch contact Opening first stage in act on the movable contact bearing（13）Part I surface（13-1）；

- in the release lever（14）On construct the second profile（14-2）, the opening of second profile in the switch contact The movable contact bearing is acted in second stage（13）Part II surface（13-2）,

Wherein described the first profile（14-1）With second profile（14-2）So offsettingly arrange relative to each other, so that The shock pulse lever of increase can be realized in the first stage（H）And increase can be realized in the second stage Spacing is opened in impact（S）.

2. the switching mechanism as described in claim 1（10）,

Characterized in that,

The first profile（14-1）And/or second profile（14-2）It is configured to from the release lever（14）Surface in dash forward The projection or cam for going out.

3. the switching mechanism as described in claim 2（10）,

Characterized in that,

The first profile（14-1）And/or second profile（14-2）By melting welding or by means of soldering and the dropout Bar（14）It is connected.

4. the switching mechanism as any one of claim 1 or 2（10）,

Characterized in that,

The first profile（14-1）And/or second profile（14-2）It is integrally formed to the release lever（14）On.

5. the switching mechanism as any one of preceding claims 1 to 3（10）,

Characterized in that,

- the switching mechanism（10）With locking pawl（15）, the locking pawl mechanically with the movable contact bearing （13）It is coupled and is supported on the release lever when the switch contact is closed（14）On, so that switching mechanism described in locking （10）；

- the locking can be by the release lever（14）Motion unclamp, thus the switch contact opening By the movable contact bearing in three stages（13）It is placed in its final position.

6. the switching mechanism as any one of preceding claims 1 to 3（10）,

Characterized in that,

The switching mechanism（10）Can mechanically so with the electromechanical protection switch equipment（1）Short circuit dropout Device（20）The tappet supported in the way of it can move（23）It is coupled so that the tappet（23）There is short circuit When mechanically act on the release lever（14）, the opening for causing the switch contact.

7. the switching mechanism as any one of preceding claims 1 to 3（10）,

Characterized in that,

The switching mechanism can mechanically so with the electromechanical protection switch equipment（1）Overload tripping device （30）It is coupled, so as to the overload tripping device when there is overload current（30）Mechanically act on the dropout Bar（14）, the opening for causing the switch contact.

8. the protection switch equipment of electromechanics（1）, have

- the switching mechanism as any one of claim 1 to 7（10）；

- short-circuit trip device（20）, the short-circuit trip device so with the switching mechanism（10）It is coupled, so as to described short Road trip gear（20）Cause the opening of the switch contact during dropout.

9. the electromechanical protection switch equipment as described in claim 8（1）, with overload tripping device（30）, the overlond trip Device so with the switching mechanism（10）It is coupled, so as in the overload tripping device（30）Cause the switch during dropout The opening of contact.