CN216957938U

CN216957938U - Electromagnetic tripping mechanism and circuit breaker

Info

Publication number: CN216957938U
Application number: CN202220490730.4U
Authority: CN
Inventors: 郑永刚; 张慎虎; 陈鸣
Original assignee: Ningbo Gongniu Low Voltage Electric Co Ltd
Current assignee: Ningbo Gongniu Low Voltage Electric Co Ltd
Priority date: 2022-03-08
Filing date: 2022-03-08
Publication date: 2022-07-12
Anticipated expiration: 2032-03-08

Abstract

The utility model discloses an electromagnetism tripping device and circuit breaker belongs to the electrical technology field. The electromagnetic tripping mechanism comprises a movable iron core, a static iron core, an ejector rod, an elastic piece and an electromagnetic assembly; the movable iron core is positioned on the first side of the electromagnetic assembly and can move relative to the electromagnetic assembly; the static iron core is connected with the electromagnetic assembly and is positioned on the second side of the electromagnetic assembly, and the second side of the electromagnetic assembly is opposite to the first side of the electromagnetic assembly; the first end of the ejector rod is connected with the movable iron core, the part of the ejector rod, which is close to the second end of the ejector rod, is movably inserted in the static iron core, and the moving direction of the ejector rod is the same as the length direction of the ejector rod; the elastic piece is sleeved outside the ejector rod and is positioned between the movable iron core and the static iron core; the electromagnetic assembly is configured to drive the movable iron core to move along the length direction of the top rod after the electrified current exceeds a threshold value so as to compress the elastic piece. The present disclosure can improve reliability.

Description

Electromagnetic tripping mechanism and circuit breaker

Technical Field

The disclosure belongs to the technical field of electricity, and particularly relates to an electromagnetic tripping mechanism and a circuit breaker.

Background

A circuit breaker is a common electrical device that is configured in an electrical circuit to perform overload and short circuit protection functions on the electrical circuit.

In the related art, an electromagnetic trip mechanism is provided in a circuit breaker. When the circuit breaker is in a closing state, the circuit is conducted, the current flowing through the electromagnetic tripping mechanism does not exceed a threshold value, and the electromagnetic tripping mechanism does not act. When the circuit is overloaded or short-circuited, the current flowing through the electromagnetic tripping mechanism exceeds a threshold value, the electromagnetic tripping mechanism acts, so that the circuit breaker is converted into an opening state, and the circuit is cut off.

However, in order to cut off the circuit in a timely manner, the electromagnetic trip mechanism needs to be operated quickly. Therefore, higher requirements are provided for the operation reliability of the electromagnetic tripping mechanism.

SUMMERY OF THE UTILITY MODEL

The embodiment of the disclosure provides an electromagnetic tripping mechanism and a circuit breaker, which can improve the reliability. The technical scheme is as follows:

on one hand, the embodiment of the disclosure provides an electromagnetic tripping mechanism, which comprises a movable iron core, a static iron core, an ejector rod, an elastic piece and an electromagnetic assembly;

the movable iron core is positioned on a first side of the electromagnetic assembly and can move relative to the electromagnetic assembly;

the static iron core is connected with the electromagnetic assembly and is positioned on the second side of the electromagnetic assembly, and the second side of the electromagnetic assembly is opposite to the first side of the electromagnetic assembly;

the first end of the ejector rod is connected with the movable iron core, the part of the ejector rod, which is close to the second end of the ejector rod, is movably inserted in the static iron core, and the moving direction of the ejector rod is the same as the length direction of the ejector rod;

the elastic piece is sleeved outside the ejector rod and is positioned between the movable iron core and the static iron core;

the electromagnetic assembly is configured to drive the movable iron core to move along the length direction of the top rod after the electrified current exceeds a threshold value so as to compress the elastic piece.

In one implementation manner of the present disclosure, the movable iron core has a first receiving groove, and the first receiving groove extends along a moving direction of the movable iron core;

the static iron core is provided with a second accommodating groove, and the extending direction of the second accommodating groove is the same as that of the first accommodating groove;

the first part of the elastic piece is inserted in the first accommodating groove, and the second part of the elastic piece is inserted in the second accommodating groove.

In one implementation manner of the present disclosure, the bottom of the second accommodating groove has a guide hole;

the extending direction of the guide hole is the same as that of the second accommodating groove;

the second end of the ejector rod penetrates through the second accommodating groove, so that the part of the ejector rod, which is close to the second end of the ejector rod, can be movably inserted into the guide hole.

In one implementation manner of the present disclosure, a slot is formed at a bottom of the first accommodating groove;

the extending direction of the slot is the same as that of the first accommodating groove;

the first end of the ejector rod penetrates through the first accommodating groove and is inserted into the slot.

In one implementation of the present disclosure, the electromagnetic assembly includes a magnetic yoke and an electromagnetic coil;

the magnetic yoke is of a frame structure;

the electromagnetic coil is positioned in the magnet yoke and is connected with the magnet yoke;

the movable iron core and the static iron core are inserted in the electromagnetic coil.

In one implementation manner of the present disclosure, the magnetic yoke includes a first plate, a second plate, and a third plate, which are connected in sequence, and the first plate and the third plate are opposite to each other;

a gap is formed in one side edge, far away from the second plate body, of the first plate body, and the movable iron core is movably inserted into the gap;

the third plate body is provided with a through hole at a position far away from the second plate body, and the static iron core is inserted into the through hole.

In one implementation of the present disclosure, the yoke further comprises a stationary contact arm;

the first end of the static contact arm is connected with one side edge of the third plate body, which is far away from the second plate body;

and one electric end of the electromagnetic coil is connected with the first end of the static contact arm.

In one implementation of the present disclosure, the second end of the stationary contact arm extends with an arc striking angle.

In one implementation of the present disclosure, the first plate, the second plate, the third plate and the static contact arm are an integrated structure.

In another aspect, an embodiment of the present disclosure provides a circuit breaker, including a housing, a movable contact arm, and the electromagnetic trip mechanism described above;

the movable contact arm is positioned in the shell, the pivoting end of the movable contact arm is pivoted with the shell, and the free end of the movable contact arm can move relative to the shell;

the electromagnetic tripping mechanism is positioned in the shell, and an electromagnetic assembly of the electromagnetic tripping mechanism is clamped and embedded with the inner wall of the shell;

the electromagnetic tripping mechanism is configured to drive the free end of the movable contact arm to move by the second end of the ejector rod after the electrified current exceeds a threshold value, so that the circuit breaker is changed from a closing state to an opening state.

The technical scheme provided by the embodiment of the disclosure has the following beneficial effects:

when the electromagnetic tripping mechanism provided by the embodiment of the disclosure is applied to a circuit breaker, the second end of the ejector rod is opposite to the movable contact arm of the circuit breaker. When the circuit breaker is in a closing state, because the current value flowing through the circuit breaker is the same as the current value flowing through the electromagnetic assembly, if a circuit in which the circuit breaker is located normally works, the electrifying current of the electromagnetic assembly does not exceed a threshold value, and the movable iron core and the static iron core are mutually separated under the action of the elastic element and are kept static. If the circuit of the circuit breaker is overloaded or short-circuited, the electrifying current of the electromagnetic assembly exceeds a threshold value, the electromagnetic assembly can drive the movable iron core to move by overcoming the elasticity of the elastic piece, the ejector rod moves along with the electromagnetic assembly until the second end of the ejector rod pushes open the movable contact arm of the circuit breaker, and the circuit breaker is converted into an opening state. When the breaker is in an opening state, the electromagnetic assembly loses power, and the movable iron core is reset again under the action of the elastic piece to wait for the next action.

At the in-process that moves the iron core and remove, because the ejector pin is pegged graft in quiet iron core, and the moving direction that moves the iron core is the same with the length direction of ejector pin, so cooperation between ejector pin and the quiet iron core can be effectual for moving the effect that plays the direction of iron core, has guaranteed to move the iron core and can drive the accurate movable contact arm of pushing away the circuit breaker of ejector pin, has improved the reliability.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an electromagnetic trip mechanism provided in an embodiment of the present disclosure;

fig. 2 is a cross-sectional view of an electromagnetic trip mechanism provided by an embodiment of the present disclosure;

fig. 3 is a cross-sectional view of an electromagnetic trip mechanism provided by an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of a configuration of an electromagnetic assembly provided by an embodiment of the present disclosure;

fig. 5 is a schematic diagram of an internal structure of a circuit breaker provided by an embodiment of the present disclosure;

fig. 6 is a schematic diagram of an internal structure of a circuit breaker according to an embodiment of the present disclosure.

The symbols in the drawings represent the following meanings:

1. a movable iron core;

11. a first accommodating groove; 12. a slot;

2. a stationary iron core;

21. a second accommodating groove; 22. a guide hole;

3. a top rod;

4. an elastic member;

5. an electromagnetic assembly;

51. a yoke; 511. a first plate body; 5111. a notch; 512. a second plate body; 513. a third plate body; 5131. a through hole; 514. a stationary contact arm; 515. an arc striking angle; 52. an electromagnetic coil;

100. a housing;

200. a movable contact arm;

300. an electromagnetic trip mechanism.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

However, in order to timely disconnect the circuit, the electromagnetic trip mechanism needs to be operated quickly. Therefore, a high requirement is put forward on the operation reliability of the electromagnetic tripping mechanism.

In order to improve the reliability of the electromagnetic tripping mechanism, an embodiment of the present disclosure provides an electromagnetic tripping mechanism, and fig. 1 is a schematic structural diagram of the electromagnetic tripping mechanism, and referring to fig. 1, the electromagnetic tripping mechanism includes a movable iron core 1, a stationary iron core 2, a push rod 3, an elastic member 4, and an electromagnetic assembly 5. Move iron core 1 and be located the first side of electromagnetic component 5, and can remove for electromagnetic component 5, quiet iron core 2 links to each other with electromagnetic component 5, and be located the second side of electromagnetic component 5, the second side of electromagnetic component 5 is relative with the first side of electromagnetic component 5, the first end of ejector pin 3 links to each other with moving iron core 1, the part that ejector pin 3 is close to self second end is movably pegged graft in quiet iron core 2, and the moving direction of ejector pin 3 is the same with the length direction of self, the elastic component 4 cover is established outside ejector pin 3, and be located and move between iron core 1 and the quiet iron core 2. The electromagnetic assembly 5 is configured to drive the plunger 1 to move along the length direction of the plunger 3 to compress the elastic member 4 after the energizing current exceeds a threshold value.

Fig. 2 and 3 are cross-sectional views of the electromagnetic trip mechanism, where fig. 2 shows the circuit breaker in a closed state, and fig. 3 shows the circuit breaker in an open state. Referring now to fig. 2 and 3, the operation of the electromagnetic trip mechanism will be described.

When the electromagnetic tripping mechanism provided by the embodiment of the disclosure is applied to a circuit breaker, the second end of the ejector rod 3 is opposite to the movable contact arm of the circuit breaker. When the circuit breaker is in a closed state (see fig. 2), since the current value flowing through the circuit breaker is the same as the current value flowing through the electromagnetic assembly 5, if the circuit breaker is in a normal operation state, the energizing current of the electromagnetic assembly 5 does not exceed the threshold, and the movable iron core 1 and the stationary iron core 2 are spaced from each other and kept stationary under the action of the elastic member 4. If the circuit breaker is overloaded or short-circuited in the circuit, the energizing current of the electromagnetic assembly 5 exceeds the threshold value, and the electromagnetic assembly 5 is enough to drive the movable iron core 1 to move against the elastic force of the elastic piece 4, so that the ejector rod 3 moves along with the moving iron core until the second end of the ejector rod 3 pushes open the movable contact arm of the circuit breaker, and the circuit breaker is converted into an opening state (see fig. 3). When the breaker is in an opening state, the electromagnetic assembly 5 loses power, and the movable iron core 1 is reset again under the action of the elastic piece 4 to wait for the next action.

In the moving process of the moving iron core 1, the ejector rod 3 is inserted into the static iron core 2, and the moving direction of the moving iron core 1 is the same as the length direction of the ejector rod 3, so that the ejector rod 3 and the static iron core 2 can be matched to effectively play a role in guiding the moving iron core 1, the moving iron core 1 is guaranteed to be capable of driving the ejector rod 3 to accurately push the movable contact arm 200 of the circuit breaker open, and the reliability is improved.

In this embodiment, the threshold value of the energizing current is an artificial set value, and is not greater than the maximum current value that can be borne by the circuit in which the circuit breaker is located.

From the foregoing, it can be seen that accurate guiding of the movable iron core 1 is a key for improving reliability of the electromagnetic trip mechanism. Therefore, how to achieve accurate guidance of the plunger 1 will be further described below.

Referring to fig. 2 again, in the present embodiment, the movable iron core 1 has a first receiving slot 11, and the first receiving slot 11 extends along the moving direction of the movable iron core 1. The static iron core 2 has a second receiving groove 21, and the extending direction of the second receiving groove 21 is the same as the extending direction of the first receiving groove 11. A first portion of the elastic element 4 is inserted into the first receiving groove 11, and a second portion of the elastic element 4 is inserted into the second receiving groove 21.

In the above implementation manner, the first receiving groove 11 and the second receiving groove 21 respectively provide receiving spaces for the elastic member 4, so that the elastic member 4 can be stably installed between the movable iron core 1 and the stationary iron core 2. Moreover, the first accommodating groove 11 extends along the moving direction of the movable iron core 1, and the extending direction of the second accommodating groove 21 is the same as the extending direction of the first accommodating groove 11, so that the elastic element 4 inserted into the first accommodating groove 11 and the second accommodating groove 21 can extend along the extending direction of the movable iron core 1, and the elastic element 4 is prevented from pushing the movable iron core 1 to be inclined.

Illustratively, the elastic member 4 is a coil spring, and the elastic member 4 is sleeved on the top rod 3. As such, the first portion of the elastic member 4 is interposed between the outer wall of the carrier rod 3 and the inner wall of the first accommodation groove 11, and the second portion of the elastic member 4 is interposed between the outer wall of the carrier rod 3 and the inner wall of the second accommodation groove 21. Further ensuring that the elastic element 4 can stretch and contract along the extending direction of the movable iron core 1.

Referring to fig. 2, in the present embodiment, the slot 12 is formed at the bottom of the first receiving slot 11, and the extending direction of the slot 12 is the same as the extending direction of the first receiving slot 11. The first end of the push rod 3 penetrates through the first accommodating groove 11 and is inserted into the slot 12.

In the above implementation, the slot 12 is used for accommodating the first end of the ejector rod 3, and provides a foundation for installation between the ejector rod 3 and the movable iron core 1. In addition, the ejector rod 3 is accommodated in the slot 12, so that the contact area between the ejector rod 3 and the movable iron core 1 can be increased, and the installation reliability between the ejector rod 3 and the movable iron core 1 is ensured. Therefore, the deviation between the movable iron core 1 and the ejector rod 3 can be effectively avoided when the movable iron core 1 drives the ejector rod 3 to move.

In the present embodiment, the bottom of the second receiving groove 21 has a guiding hole 22, and the extending direction of the guiding hole 22 is the same as the extending direction of the second receiving groove 21. The second end of the top rod 3 penetrates through the second receiving groove 21, so that the part of the top rod 3 close to the second end thereof can be movably inserted into the guide hole 22.

Because the extending direction of the guide hole 22 is the same as the extending direction of the second receiving groove 21, and the extending direction of the second receiving groove 21 is the same as the moving direction of the movable iron core 1, the ejector rod 3 is inserted into the guide hole 22, and the guide accuracy of the movable iron core 1 can be improved effectively through the matching between the ejector rod 3 and the guide hole 22.

The cooperation between the movable iron core 1, the stationary iron core 2, the carrier rod 3 and the elastic member 4 is described above, and the electromagnetic assembly 5 is described below.

Fig. 4 is a schematic structural diagram of the electromagnetic assembly 5, and in conjunction with fig. 4, in the present embodiment, the electromagnetic assembly 5 includes a yoke 51 and an electromagnetic coil 52. The yoke 51 is a frame structure, the electromagnetic coil 52 is located in the yoke 51, and the electromagnetic coil 52 is connected to the yoke 51. The movable iron core 1 and the static iron core 2 are inserted in the electromagnetic coil 52.

In the above implementation, the yoke 51 can not only provide a support base for the electromagnetic coil 52, but also introduce current to the electromagnetic coil 52. Therefore, a coil framework which is usually configured in the related technology can be omitted, the production cost is reduced, and the miniaturization design of the electromagnetic tripping mechanism is facilitated. The electromagnetic coil 52 can drive the movable iron core 1 to move after the current flowing through the electromagnetic coil exceeds a threshold value. It is easily understood that the yoke 51 and the electromagnetic coil 52 are both made of an electrically conductive material.

Illustratively, the yoke 51 includes a first plate body 511, a second plate body 512, and a third plate body 513 connected in sequence, the first plate body 511 and the third plate body 513 being opposite to each other. A notch 5111 is formed in a side of the first plate 511 away from the second plate 512, and the movable iron core 1 is movably inserted into the notch 5111. A through hole 5131 is formed in a position of the third plate body 513, which is far away from the second plate body 512, and the static iron core 2 is inserted into the through hole 5131.

The second plate body 512 is used for connecting the first plate body 511 and the third plate body 513, so that the first plate body 511, the second plate body 512 and the third plate body 513 are integrated. The first plate 511 is used for supporting the movable iron core 1, and the movable iron core 1 is accommodated in the notch 5111, so that the movable iron core 1 can stably move in the notch 5111. The third plate 513 is used for supporting the stationary core 2, and the stationary core 2 is accommodated in the through hole 5131, so that the stationary core 2 can be stably installed in the through hole 5131.

Alternatively, the notch 5111 is replaced by a structure similar to the through hole 5131, and can also play a role in positioning and guiding the movable iron core 1.

With continued reference to fig. 4, in the present embodiment, the magnetic yoke 51 further includes a static contact arm 514, a first end of the static contact arm 514 is connected to a side of the third plate 513 away from the second plate 512, and a connecting end of the electromagnetic coil 52 is connected to the first end of the static contact arm 514.

In the above implementation, one electrical terminal of the electromagnetic coil 52 is connected to a first end of the stationary contact arm 514, and the stationary contact arm 514 is used to contact the movable contact arm 200 of the circuit breaker, thereby introducing current into the electromagnetic coil 52. The other electrical terminal of the electromagnetic coil 52 is connected to the circuit breaker's peripheral circuit, thereby drawing current.

Illustratively, the first plate 511, the second plate 512, the third plate 513 and the static contact arm 514 are a unitary structural member. By the design, the structure of the magnetic yoke 51 is more compact, and the production efficiency of the electromagnetic tripping mechanism is improved.

In this embodiment, the second end of the stationary contact arm 514 extends to form an arc striking angle 515, and the arc striking angle 515 extends into an arc extinguish chamber of the circuit breaker, so that an arc generated when the movable contact arm 200 and the stationary contact arm 514 are opened and closed can be introduced into the arc extinguish chamber, and the reliability of the electromagnetic tripping mechanism is further improved.

It will be readily appreciated that since the arc ignition angle 515 is formed by extending the second end of the stationary contact arm 514, the arc ignition angle 515 is also a unitary structural member with the third plate 513.

As can be seen from the foregoing, the electromagnetic trip mechanism can be applied to a circuit breaker, and the circuit breaker equipped with the electromagnetic trip mechanism shown in fig. 1 to 4 will be described below.

Fig. 5 is a schematic diagram of an internal structure of the circuit breaker, and in conjunction with fig. 5, in this embodiment, the circuit breaker includes a housing 100, a movable contact arm 200, and an electromagnetic trip mechanism 300 shown in fig. 1 to 4. The movable contact arm 200 is located in the casing 100, a pivoting end of the movable contact arm 200 is pivoted with the casing 100, a free end of the movable contact arm 200 can move relative to the casing 100, the electromagnetic trip mechanism 300 is located in the casing 100, and the electromagnetic assembly 5 of the electromagnetic trip mechanism 300 is embedded with an inner wall of the casing 100. The electromagnetic trip mechanism 300 is configured to, after the energizing current exceeds the threshold value, the second end of the jack 3 drives the free end of the movable contact arm 200 to move, so that the circuit breaker is changed from the closing state to the opening state.

Fig. 6 is a schematic diagram of an internal structure of the circuit breaker, and fig. 6 and 5 are different in that fig. 5 illustrates that the circuit breaker is in a closed state, fig. 6 illustrates that the circuit breaker is in an open state, and the electromagnetic trip mechanism 300 is not reset.

When the circuit breaker is in a closed state, the moving contact arm 200 contacts the stationary contact arm 514 so that current can be drawn into the electromagnetic coil 52. If the circuit of the circuit breaker works normally, the current value does not exceed the threshold value, and the movable iron core 1 and the static iron core 2 are separated from each other under the action of the elastic element 4 and keep static. If the circuit of the circuit breaker is overloaded or short-circuited, the current value exceeds the threshold value, the electromagnetic assembly 5 is enough to drive the movable iron core 1 to move against the elastic force of the elastic piece 4, so that the ejector rod 3 moves along with the movable iron core until the movable contact arm 200 of the circuit breaker is pushed open, and the circuit breaker is converted into an opening state. When the breaker is in an opening state, the electromagnetic assembly 5 loses power, and the movable iron core 1 is reset again under the action of the elastic piece 4 to wait for the next action.

The above description is intended to be exemplary only and not to limit the present disclosure, and any modification, equivalent replacement, or improvement made without departing from the spirit and scope of the present disclosure is to be considered as the same as the present disclosure.

Claims

1. An electromagnetic tripping mechanism is characterized by comprising a movable iron core (1), a static iron core (2), a push rod (3), an elastic piece (4) and an electromagnetic component (5);

the movable iron core (1) is positioned on a first side of the electromagnetic assembly (5) and can move relative to the electromagnetic assembly (5);

the static iron core (2) is connected with the electromagnetic assembly (5) and is positioned at the second side of the electromagnetic assembly (5), and the second side of the electromagnetic assembly (5) is opposite to the first side of the electromagnetic assembly (5);

the first end of the ejector rod (3) is connected with the movable iron core (1), the part of the ejector rod (3) close to the second end of the ejector rod is movably inserted into the static iron core (2), and the moving direction of the ejector rod (3) is the same as the length direction of the ejector rod;

the elastic piece (4) is sleeved outside the ejector rod (3) and is positioned between the movable iron core (1) and the static iron core (2);

the electromagnetic assembly (5) is configured to drive the movable iron core (1) to move along the length direction of the ejector rod (3) after the electrified current exceeds a threshold value so as to compress the elastic piece (4).

2. The electromagnetic trip mechanism according to claim 1, characterized in that the movable iron core (1) has a first receiving groove (11), the first receiving groove (11) extending along the moving direction of the movable iron core (1);

the static iron core (2) is provided with a second accommodating groove (21), and the extending direction of the second accommodating groove (21) is the same as that of the first accommodating groove (11);

a first part of the elastic piece (4) is inserted in the first accommodating groove (11), and a second part of the elastic piece (4) is inserted in the second accommodating groove (21).

3. The electromagnetic trip mechanism according to claim 2, characterized in that the bottom of the second receiving groove (21) has a guide hole (22);

the extending direction of the guide hole (22) is the same as that of the second accommodating groove (21);

the second end of the ejector rod (3) penetrates through the second accommodating groove (21), so that the part, close to the second end, of the ejector rod (3) can be movably inserted into the guide hole (22).

4. The electromagnetic trip mechanism according to claim 2, characterized in that the bottom of the first receiving groove (11) has a slot (12);

the extending direction of the slot (12) is the same as that of the first accommodating groove (11);

the first end of the ejector rod (3) penetrates through the first accommodating groove (11) and is inserted into the slot (12).

5. An electromagnetic trip mechanism according to any of claims 1-4, characterized in that the electromagnetic assembly (5) comprises a magnetic yoke (51) and an electromagnetic coil (52);

the magnetic yoke (51) is of a frame structure;

the electromagnetic coil (52) is positioned in the magnetic yoke (51), and the electromagnetic coil (52) is connected with the magnetic yoke (51);

the movable iron core (1) and the static iron core (2) are inserted in the electromagnetic coil (52).

6. The electromagnetic trip mechanism according to claim 5, characterized in that the magnetic yoke (51) comprises a first plate body (511), a second plate body (512) and a third plate body (513) which are connected in sequence, the first plate body (511) and the third plate body (513) being opposite;

a notch (5111) is formed in one side edge, away from the second plate body (512), of the first plate body (511), and the movable iron core (1) is movably inserted into the notch (5111);

the part of the third plate body (513) far away from the second plate body (512) is provided with a through hole (5131), and the static iron core (2) is inserted into the through hole (5131).

7. The electromagnetic trip mechanism according to claim 6, wherein the magnetic yoke (51) further comprises a stationary contact arm (514);

the first end of the static contact arm (514) is connected with one side of the third plate body (513) far away from the second plate body (512);

one end of the electromagnetic coil (52) is connected with the first end of the static contact arm (514).

8. The electromagnetic trip mechanism according to claim 7, wherein the second end of the stationary arm (514) extends with an arc ignition angle (515).

9. The electromagnetic trip mechanism according to claim 7, wherein the first plate (511), the second plate (512), the third plate (513), and the stationary arm (514) are a unitary structural member.

10. A circuit breaker comprising a housing (100), a movable contact arm (200) and an electromagnetic trip mechanism (300) of any of claims 1-9;

the movable contact arm (200) is positioned in the shell (100), the pivoting end of the movable contact arm (200) is pivoted with the shell (100), and the free end of the movable contact arm (200) can move relative to the shell (100);

the electromagnetic tripping mechanism (300) is positioned in the shell (100), and an electromagnetic assembly (5) of the electromagnetic tripping mechanism (300) is clamped and embedded with the inner wall of the shell (100);

the electromagnetic tripping mechanism (300) is configured in such a way that after the electrified current exceeds a threshold value, the second end of the ejector rod (3) drives the free end of the movable contact arm (200) to move, so that the breaker is changed from a closing state to an opening state.