CN217507249U

CN217507249U - Thermomagnetic trip for a circuit breaker and circuit breaker

Info

Publication number: CN217507249U
Application number: CN202221584472.2U
Authority: CN
Inventors: 刘振忠; 庄文浩; 余刚
Original assignee: Schneider Electric China Co Ltd
Current assignee: Schneider Electric China Co Ltd
Priority date: 2022-06-23
Filing date: 2022-06-23
Publication date: 2022-09-27
Anticipated expiration: 2032-06-23

Abstract

A thermomagnetic trip for a circuit breaker and a circuit breaker. The thermomagnetic release comprises: an actuating unit including an actuating member and configured such that the actuating member does not operate when a main circuit of the circuit breaker is normally operated or an overload occurs and operates when the main circuit of the circuit breaker is short-circuited; a trip actuation member having a portion actuatable by the actuation member to be moved by movement of the actuation member; a bimetal arranged so that thermal deformation deflection of the bimetal can touch and press the tripping actuating component to move the tripping actuating component; a trip member abutting a portion of the trip actuating member and configured to be directly movable upon actuation of movement of the trip facilitating member.

Description

Thermomagnetic trip for a circuit breaker and circuit breaker

Technical Field

The present invention relates to electrical releases, and more particularly, to a thermomagnetic release for a circuit breaker. The present invention also relates to circuit breakers, and more particularly, to circuit breakers having a thermomagnetic trip.

Background

A release is a common device for releasing a holding mechanism of a circuit breaker to automatically open the circuit breaker, and can be generally classified into a magnetic release, an electronic release, and a thermal magnetic release, and the thermal magnetic release has a very wide application due to advantages of low cost, stable performance, long service life, and the like.

With the continuous promotion of policies such as green and low carbon, the development and utilization of new energy become the focus of attention of people, and corresponding services are rapidly developed. Dc circuit breakers are gaining more and more attention. In short years, the technology of dc circuit breakers has evolved from the previous 1000V four-pole string to 1200V four-pole string, 1500V three-pole string and 1500V two-pole string. The volume of the product with the same performance is smaller and smaller, and the cost is lower and lower.

These dc circuit breakers require a fast tripping speed, however, when the trip actuating member of the current thermomagnetic trip is actuated, the trip member is often released first, and then the trip member moves to trip, which results in a slow tripping speed.

Therefore, there is a need to provide a thermomagnetic trip with a quick trip, which can be used in a dc circuit breaker to obtain better breaking performance. Of course, the thermal magnetic release can also be used for an alternating current circuit breaker.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned drawbacks and deficiencies, it is an object of the present invention to at least solve the above-mentioned problems of the prior art.

The utility model provides a thermomagnetic release for circuit breaker, include: an actuating unit including an actuating member and configured such that the actuating member does not operate when a main circuit of the circuit breaker is normally operated or an overload occurs and operates when the main circuit of the circuit breaker is short-circuited; a trip actuation member having a portion actuatable by the actuation member to be moved by movement of the actuation member; a bimetal strip, wherein the bimetal strip is arranged to enable the thermal deformation deflection of the bimetal strip to touch and press the tripping actuating component so as to enable the tripping actuating component to move; a trip member abutting a portion of the trip actuating member and configured to be directly movable upon actuation of movement of the trip facilitating member.

Preferably, the trip member is configured to be directly translationally movable upon actuation of movement of the trip promoting member.

Preferably, the actuating unit further comprises an electromagnet unit consisting of a movable armature and a fixed armature, wherein the movable armature is carried and fixed on the actuating component, so that the movable armature does not act and the actuating component does not act when the main circuit of the circuit breaker operates normally or an overload occurs, and the movable armature acts and the actuating component acts when the main circuit of the circuit breaker short-circuits.

Preferably, the actuating unit further comprises a current carrying plate assembly, the actuating member being connected to a first portion of the current carrying plate assembly, the static armature being fixed to a second portion of the current carrying plate assembly such that the static armature and the dynamic armature oppose each other.

Preferably, the bimetal strip is fixed to the current carrying plate assembly.

Preferably, the actuating member is pivotally connected to the first portion of the current carrying plate assembly.

Preferably, the trip actuating member has a pivotable body and a first arm connected to the body, wherein the first arm is capable of being contacted by the actuating member and abutting the trip member such that pivoting of the actuating member is capable of contacting the first arm to pivot the first arm to directly move the trip member.

Preferably, the trip actuating member further comprises a second arm connected to the body, and the thermal deformation deflection of the bimetallic strip can press the second arm of the trip actuating member to enable the trip actuating member to perform pivoting movement, so that the first arm of the trip actuating member drives the trip piece to directly move.

Preferably, the current carrying plate assembly is in communication with a main circuit of a circuit breaker.

The utility model also provides a circuit breaker, include as above thermomagnetic release.

Drawings

The above and other features and advantages of exemplary embodiments of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are for illustrative purposes only and do not limit the scope of the present invention in any way, wherein:

fig. 1 shows a schematic side view illustrating the internal structure of a thermomagnetic release according to the present invention when no overload and short-circuit faults occur;

FIG. 2 is a schematic side view showing the internal structure of the thermomagnetic trip shown in FIG. 1 in the event of a short-circuit fault;

FIG. 3 is a schematic side view showing the internal structure of the thermal magnetic release shown in FIG. 1 in the event of an overload fault;

FIG. 4 is a schematic perspective view showing the internal structure of the thermomagnetic trip shown in FIG. 1;

fig. 5 is a schematic external view showing a thermomagnetic release according to the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

The foregoing and other features, aspects and utilities of the present disclosure will be apparent from the following detailed description of the embodiments when read in conjunction with the accompanying drawings. Directional terms as referred to in the following examples, for example: up, down, left, right, front or rear, etc., are simply directions with reference to the drawings. Therefore, the directional terminology used is for the purpose of description and is not intended to be limiting, and moreover, like reference numerals will be used to refer to like elements throughout.

It is first of all stated that the terms "overload", "overload current" or "overload fault" mentioned above and in the following refer to a situation in which an overload occurs in a circuit, for example, a situation in which the current is 140% -300% of the rated current; the term "short circuit", "short circuit current" or "short circuit fault" refers to a short circuit in the circuit, for example, a current greater than 300% of the rated current. In other words, although in a particular sense a short circuit may be considered as a very specific overload situation, in this context both are different fault types, having different meanings, and both comprise current ranges which do not overlap, an overload current being a current which is relatively small in excess of the rated current, and a short-circuit current being a current which is relatively large in excess of the rated current, i.e. a short-circuit current is not an overload current, also not referred to or considered as an overload current.

Referring now to fig. 1-5, a thermomagnetic release according to the present invention is described.

Reference is first made to fig. 1, which is a schematic side view showing the internal structure of a thermomagnetic trip according to the present invention when no overload and short circuit faults occur, in which the housing accommodating the internals of the thermomagnetic trip is not shown in order to better show the internal structure of the thermomagnetic trip.

According to the utility model discloses a thermomagnetic release for circuit breaker includes: an actuating unit including an actuating part 20 and configured such that the actuating part does not operate when a main circuit of the circuit breaker is normally operated or an overload occurs and operates when the main circuit of the circuit breaker is short-circuited; a trip actuating member 50, the trip actuating member 50 having a portion that is actuatable by the actuating member 20 to be moved by movement of the actuating member 20; a trip member 70, the trip member 70 abutting a portion of the trip actuating member 50 and configured to be capable of translational movement driven by movement of the trip promoting member, the trip member 70 being capable of extending out of a housing (as shown in fig. 5) housing internal structure of the thermomagnetic trip to cooperate with a movable contact assembly, not shown, to cause the movable contact assembly to correspondingly act upon translational movement to effect separation of the movable and stationary contacts; and a bimetal 60, wherein the bimetal 60 is arranged to enable the thermal deformation deflection of the bimetal 60 to touch and press the tripping actuating member 50 to enable the tripping actuating member to move. It is well known to those skilled in the art how the movement of the release 70 causes the movable contact assembly to act accordingly, and therefore will not be described in detail herein.

Further, referring to fig. 1, the actuating unit includes: a current carrying plate assembly 10; an actuating member 20, the actuating member 20 being connected to a first portion of the current carrying plate assembly 10; a moving armature 30, the moving armature 30 being carried and fixed on the actuating member 20; a static armature 40, the static armature 40 being fixed to the second portion of the current carrying plate assembly 10 such that the static armature 40 and the moving armature 30 oppose each other to collectively form an electromagnet unit configured to operate when the main circuit of the circuit breaker is operating normally or is not operating when an overload occurs and the main circuit of the circuit breaker is short-circuited. It should be noted that although the actuating unit is described and illustrated herein as a unit actuated by an electromagnet, the present invention is not limited thereto, but the actuating unit may be in other forms as long as the actuating unit has a means for actuating a trip actuating member and is not operated when the main circuit is normally operated or an overload occurs and is operated when the main circuit of the circuit breaker is short-circuited.

Meanwhile, it should be noted that although the actuating member 20 and the trip actuating member 50 are shown as pivotable members in fig. 1 (described in further detail below), it is obvious that the present invention is not limited to the situation shown in the drawings, that is, the actuating member 20 or the trip actuating member 50 may be members with other motion forms, such as a translational motion or a translational motion and a rotational motion. That is, the present invention is based on the idea that when an overload occurs (as shown in fig. 3), the bimetal moves, so that the trip actuating member moves, and the trip member is actuated to move in translation; and in the presence of a short circuit (as shown in fig. 2), the actuation member moves, thus causing the trip actuation member to move (which normally moves earlier than the bimetal because the magnetic response of the electromagnet unit is faster than the thermal response of the bimetal), thus actuating the trip translational movement. It can be seen that the movement of the actuating member is such as to move the release member, for example it may be such that the moving armature slides/translates towards the static armature, regardless of the form of movement of the actuating member.

In addition, it should be noted that although in the present description the release member 70 is shown as a translational moving part, it is obvious that the present invention is not limited to the situation shown in the drawings, i.e. the release member 70 may be a part of other moving forms, for example, may rotate or translate plus rotate. That is, the present invention is conceived in that, when an overload occurs (as shown in fig. 3) or a short circuit occurs (as shown in fig. 2), the trip actuating part moves to directly drive the trip member to move without an intermediate process requiring release of the trip member, thereby making the trip speed faster as long as the trip member can be directly driven by the trip actuating part regardless of the movement form of the trip member

Referring now to fig. 1-5 concurrently, wherein fig. 2 is a schematic side view showing the internal structure of the thermomagnetic trip shown in fig. 1 in the event of a short-circuit fault; FIG. 3 is a schematic side view showing the internal structure of the thermal magnetic release shown in FIG. 1 in the event of an overload fault; FIG. 4 is a schematic perspective view showing the internal structure of the thermomagnetic trip shown in FIG. 1; and fig. 5 is a schematic external view showing the thermomagnetic trip shown in fig. 1.

With respect to the design of the actuating component and its associated components, in a preferred embodiment of the present invention, the actuating component 20 is pivotally connected to a first portion of the current carrying plate assembly 10, the moving armature 30 is attached to the actuating component 20, the static armature 40 is connected to a second portion of the current carrying plate assembly 10, the moving armature 30 and the static armature 40 constitute one electromagnet unit opposite each other, and the current carrying plate assembly 10 is in communication with the main circuit of the circuit breaker, whereby the electromagnet unit can be energized through the current carrying plate assembly 10. It can be seen that in a preferred embodiment of the invention, the current carrying plate assembly simultaneously serves to energise and support the electromagnet unit, thereby facilitating structural simplification. Of course, the electromagnet unit may be energized in other ways as long as the current energizing the electromagnet unit is correlated with the current of the main circuit of the circuit breaker (for example, but not limited to, there is a proportional relationship between the energizing current and the main circuit current) so that the action of the electromagnet unit is correlated with the current of the main circuit (for example, an overload current and a short-circuit current).

Further, as shown in fig. 1-3, the actuating member 20 extends upwardly such that an uppermost end of the actuating member 20 is higher than a lowermost end of the trip actuating member 50, such that pivotal movement of the actuating member 20 can actuate the trip actuating member 50. The pivoting movement enables actuation of the respective components in a small space, thereby facilitating miniaturization of the entire thermomagnetic trip. Furthermore, the actuation by the pivoting movement is also advantageous for improving the working stability and the service life.

With respect to the design of the trip actuating member and its related components, in a preferred embodiment of the present invention, referring to fig. 2 and 3, the trip actuating member 50 has a pivotable body 503 and first and

second arms

501 and 502 connected to the body 503, such that pivoting of the actuating member 20 can press the first arm 501 to pivot the first arm 501, thereby causing translational movement of the trip device 70 through the first arm 501. As previously mentioned, the structural design of the pivoting movement of the trip actuating member has advantages such as miniaturization of the thermomagnetic trip, simple structure, reliable operation and long service life.

With respect to the design of the bimetal strip and its related components, in the preferred embodiment of the present invention, referring to fig. 1-3, the bimetal strip 60 is connected to the current-carrying plate assembly, and when the circuit is overloaded, it is heated by the component attached to the current-carrying plate assembly, so as to deform and deflect, and further touch the second arm 502 of the trip actuating component 50, so that the trip actuating component 50 drives the first arm 501 to perform a pivotal motion, and further, the trip 70 is moved in a translational motion by the first arm 501.

Thus, the current for the electromagnet unit to act can be set to a threshold value corresponding to the minimum short-circuit current, that is, the electromagnet unit does not act when the current is smaller than the threshold value, that is, when the short-circuit fault does not occur (including when the circuit works normally and the overload fault occurs); and when the current is larger than the threshold value, namely a short-circuit fault occurs, the electromagnet unit acts. More specifically, the electromagnet unit is arranged to be energized by the current carrying plate assembly 10 and is arranged to be inactive when the main circuit of the circuit breaker is operating normally or is overloaded, and to be active when the main circuit of the circuit breaker is shorted, so that the moving armature 30 moves towards the static armature 40, so that the actuating member 20 rotates to touch the trip actuating member 50, so that the trip 70 moves in translation.

On the other hand, the bimetal 60 is arranged to be heated by the current carrying plate assembly 10, and is arranged such that when the main circuit of the circuit breaker normally operates, the thermal deformation deflection of the bimetal 60 is not enough to press the trip actuating member 50 to move the trip actuating member 50, and when the main circuit of the circuit breaker is overloaded, the thermal deformation deflection of the bimetal 60 presses the trip actuating member 50 to move the trip piece 70 in a translation manner.

In a preferred embodiment of the present invention, there is also provided a circuit breaker, including: a thermomagnetic release as described above.

Although the present invention has been described in the specification and illustrated in the drawings with reference to various embodiments, it will be understood by those skilled in the art that the above embodiments are merely preferred embodiments, and that certain technical features in the embodiments may not be necessary to solve specific technical problems, so that these technical features may not be included or omitted without affecting the solution of the technical problems or the formation of the technical solutions; furthermore, the features, elements, and/or functions of one embodiment may be combined, coupled, or coordinated with the features, elements, and/or functions of one or more other embodiments as appropriate, unless the combination, coupling, or coordination is clearly not practical.

Claims

1. A thermomagnetic trip for a circuit breaker, characterized in that it comprises:

an actuating unit including an actuating member and configured such that the actuating member does not operate when a main circuit of the circuit breaker is normally operated or an overload occurs and operates when the main circuit of the circuit breaker is short-circuited;

a trip actuation member having a portion actuatable by the actuation member to be moved by movement of the actuation member;

a bimetal strip, wherein the bimetal strip is arranged to enable the thermal deformation deflection of the bimetal strip to touch and press the tripping actuating component so as to enable the tripping actuating component to move;

a trip member abutting a portion of the trip actuating member and configured to be directly movable upon actuation of movement of the trip facilitating member.

2. The thermomagnetic trip of claim 1, wherein the trip member is configured to be directly translationally movable upon actuation by movement of the trip-promoting member.

3. The thermomagnetic trip according to claim 2, characterized in that said actuating unit further comprises an electromagnet unit consisting of a moving armature and a static armature, said moving armature being carried and fixed on said actuating member, so that said moving armature does not act and therefore said actuating member does not act when the main circuit of the circuit breaker is operating normally or in the event of an overload, and said moving armature acts and therefore said actuating member acts when the main circuit of the circuit breaker is short-circuited.

4. The thermomagnetic trip of claim 3, wherein the actuation unit further comprises a current carrying plate assembly, the actuation component being coupled to a first portion of the current carrying plate assembly, the static armature being fixed to a second portion of the current carrying plate assembly such that the static armature and the dynamic armature oppose one another.

5. The thermomagnetic trip of claim 4, wherein the bimetallic strip is secured to the current carrying plate assembly.

6. The thermomagnetic trip of claim 4, wherein the actuation member is pivotally coupled to the first portion of the current carrying plate assembly.

7. The thermomagnetic release of any one of claims 1-6, wherein the release actuating member has a pivotable body and a first arm connected to the body, wherein the first arm is depressible by the actuating member and is in abutment with the release member such that pivoting of the actuating member depresses the first arm to pivot the first arm and thereby directly move the release member.

8. The thermomagnetic trip of claim 6, wherein the trip actuation member further comprises a second arm connected to the body, wherein the thermally deformed deflection of the bimetallic strip is capable of depressing the second arm of the trip actuation member to cause pivotal movement of the trip actuation member, thereby causing the first arm of the trip actuation member to drive direct movement of the trip member.

9. The thermomagnetic trip of any of claims 4-6, wherein the current carrying plate assembly is in communication with a main circuit of a direct current circuit breaker.

10. A circuit breaker, characterized in that it comprises a thermomagnetic trip as claimed in any one of claims 1 to 9.