CN221947061U - Small-sized circuit breaker - Google Patents

Abstract

The utility model discloses a miniature circuit breaker, which relates to the technical field of circuit breakers and comprises a shell, wherein a fixed contact and a movable contact are arranged in the shell, the movable contact is in driving connection with a contact system, an electromagnetic system for driving the contact system to act is also arranged in the shell, and the electromagnetic system comprises a bracket, a wiring board, a coil, a magnetism increasing piece, a release and the fixed contact; one end of the coil is electrically connected with the wiring board, and the other end of the coil is electrically connected with the static contact; the magnetism increasing piece is made of ferromagnetic materials and is insulated from the coil, and the magnetism increasing piece and the release pass through the coil and are fixed by the bracket; the bracket is made of high-temperature resistant insulating material, and can wrap the upper part of the silver point of the static contact and the coil and isolate the region where the electric arc is generated; and the release acts to push the contact system to complete the breaking action. The circuit breaker of the utility model is reinforced under the action of the coil even though the induction magnetic field generated by smaller current is generated, and the stress direction of the electric arc faces the arc extinguishing chamber no matter the current direction, so that the nonpolar reinforced magnetic blowing effect is finally formed.

Description

Small-sized circuit breaker

Technical Field

The utility model belongs to the technical field of circuit breakers, and particularly relates to a miniature circuit breaker.

Background

With the large-scale construction and planning of new energy systems, the duty ratio of the direct current power transmission and distribution system is increased year by year, and particularly, the improvement of a double-carbon target further accelerates the energy structure transformation, and renewable energy sources become dominant. In order to improve the system efficiency and reduce the cost, the voltage level of the direct current distribution system is continuously improved, the voltage level of the direct current load is also improved, and new requirements are also put forward for the performance of the terminal distribution circuit breaker. The breaking capacity of the circuit breaker to critical load current is an important index for checking the performance and reliability of the circuit breaker.

Because the critical load current is smaller, when the circuit breaker with a conventional structure is disconnected, the critical load current cannot generate strong air blowing and magnetic blowing effects, and the mode of adding the permanent magnet is adopted to enhance the magnetic blowing effect, so that the arc is pushed into the arc extinguishing chamber to complete the disconnection. The circuit breaker with the permanent magnet cannot change the current direction, has hard requirements on the polarity of the connection, and can cause more serious consequences due to current breaking under the condition of wrong polarity of the connection. Along with the increase of the service life of the permanent magnet, the high temperature influence of the arc on the permanent magnet during breaking and the high temperature influence of the inherent temperature rise of the circuit breaker when the circuit breaker is in high-environment-temperature operation, the magnetism of the permanent magnet can be gradually reduced, so that the magnetic blowing effect is reduced, and the breaking performance, the reliability and the service life of the circuit breaker are greatly influenced.

At present, the breaking performance of the miniature circuit breaker reaches the bottleneck, and the problem that the magnetism of a permanent magnet in the miniature circuit breaker is deteriorated along with the increase of the service life becomes a technical problem in the field.

Disclosure of utility model

The present utility model aims to solve the above technical problems to a certain extent. Therefore, the utility model provides the miniature circuit breaker, which adopts a mode of enhancing the induction magnetic field to enhance the magnetic blowing effect, improves the breaking effect of the critical load current of the circuit breaker, has the advantage of no polarity, and can improve the breaking performance, the reliability and the service life of the miniature circuit breaker.

In order to achieve the above purpose, the present utility model provides the following technical solutions:

The miniature circuit breaker comprises a shell, wherein a fixed contact and a moving contact are arranged in the shell, the moving contact is in driving connection with a contact system, an electromagnetic system for driving the contact system to act is further arranged in the shell, and the electromagnetic system comprises a bracket, a wiring board, a coil, a magnetism increasing piece, a release and the fixed contact; one end of the coil is electrically connected with the wiring board, and the other end of the coil is electrically connected with the static contact; the magnetizing piece is made of ferromagnetic materials and is insulated from the coil, and the magnetizing piece and the release pass through the coil and are fixed by the bracket; the support is made of high-temperature resistant insulating material, and can wrap the part above the silver point of the static contact and the coil and isolate the part from an arc generating area; and the release acts to push the contact system to complete breaking action.

Preferably, the release comprises a framework, an iron core, an armature and a push rod; the ejector rod and the framework are made of insulating materials, and the iron core and the armature are made of ferromagnetic materials; the iron core is fixed in the framework, and the armature slides in the framework and magnetically attracts the iron core when current passes through the armature; the ejector rod penetrates through and slides in the center of the iron core, one end of the ejector rod is close to the contact system, and the other end of the ejector rod is connected with the armature.

Preferably, a spring is sleeved outside the rod body, wherein the ejector rod is positioned between the iron core and the armature.

Preferably, the magnetism increasing piece is wrapped with an insulating sleeve.

Preferably, the first magnetic conductive plate and the second magnetic conductive plate are respectively arranged on the shell at two sides of the electromagnetic system, and the first magnetic conductive plate and the second magnetic conductive plate are respectively positioned at two sides of a region where the moving contact and the fixed contact generate electric arcs and are insulated and isolated from the region.

Preferably, the upper parts of the first magnetic conductive plate and the second magnetic conductive plate are provided with bending structures, and the bending structures of the first magnetic conductive plate and the second magnetic conductive plate are respectively contacted with two ends of the magnetism increasing piece and are insulated from the coil.

Preferably, the moving contact and the fixed contact are provided with arc-extinguishing chambers below, each arc-extinguishing chamber comprises a plurality of arc-extinguishing grid sheets which are arranged at intervals in a linear mode, each arc-extinguishing grid sheet is arranged vertically, and the linear arrangement direction of each arc-extinguishing grid sheet forms an included angle of 5-15 degrees with the horizontal direction.

Preferably, the housing has an exhaust hole, a certain gap exists between the end of the arc extinguishing gate sheet and the housing, and the closer the arc extinguishing gate sheet is to the exhaust hole, the larger the gap is. The electric arc enters an arc extinguishing chamber with increased capacity, is elongated under the action of an arc striking angle, is cut by an arc extinguishing grid sheet, and high-temperature gas generated by the arc extinguishing chamber is discharged from an exhaust hole.

Preferably, the shell is rotatably connected with a handle, the contact system is connected to the handle, and the handle rotates to drive the contact system to rotate so as to complete the opening and closing actions.

Preferably, the contact system is connected to the handle by a bent rod.

The utility model discloses the following technical effects:

The miniature circuit breaker of the utility model is provided with an electromagnetic system in the shell for driving the contact system to act, and when overcurrent occurs in a circuit or critical load current is disconnected, an arc is generated between the moving contact and the fixed contact. The induction magnetic field generated by the current is enhanced through the coil and is gathered in the magnetism increasing piece, so that the magnetism increasing piece which is not magnetic originally is converted into a ferromagnetic part with stronger magnetism, the magnetic fields at the two ends of the magnetism increasing piece are conducted through the magnetic conduction plates at the two ends of the magnetism increasing piece, the magnetic field with the direction perpendicular to the arc path is formed at the two sides of the arc, and the arc moves towards the arc extinguishing chamber under the action of Lorentz force. Even the induced magnetic field generated by the smaller critical load current is enhanced under the action of the coil, and no matter the current direction, the arc stress direction faces the arc extinguishing chamber, so that the nonpolar enhanced magnetic blowing effect is finally formed.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of a miniature circuit breaker according to an embodiment of the present utility model with a side housing removed;

fig. 2 is an isometric view of a miniature circuit breaker with one side housing removed in accordance with an embodiment of the present utility model;

Fig. 3 is a closing state diagram of the miniature circuit breaker according to the embodiment of the present utility model, in which the side housing, the magnetic conductive plate and the cover plate are removed;

Fig. 4 is an isometric view of a miniature circuit breaker of an embodiment of the present utility model in a closed state with one side housing, magnetically permeable plate and cover plate removed;

Fig. 5 is a state diagram of the miniature circuit breaker of the embodiment of the utility model after the shell, the magnetic conduction plate and the cover plate are removed;

Fig. 6 is an isometric view of a miniature circuit breaker of an embodiment of the present utility model in a disconnected state with a side housing, a magnetically permeable plate, and a cover plate removed;

FIG. 7 is a schematic diagram of an electromagnetic system according to an embodiment of the present utility model;

FIG. 8 is an exploded view of an electromagnetic system in an embodiment of the utility model;

FIG. 9 is a diagram showing the structure and the positional relationship between the magnetism enhancing member and the magnetism guiding plate according to the embodiment of the present utility model;

FIG. 10 is a diagram showing the magnetizing effect of the magnetizing member and the magnetically permeable plate according to an embodiment of the present utility model;

Fig. 11 is an arc path diagram of an embodiment of the present utility model.

1, A shell; 2. a handle; 3. bending a rod; 4. a contact system; 5. an electromagnetic system; 6. a coil; 7. a wire holder; 12. an arc extinguishing chamber; 13. a first magnetic conduction plate; 14. a cover plate; 15. a moving contact; 16. jumping buckle; 18. a stationary contact; 19. an arc partition wall; 20. arc extinguishing grid plates; 21. arc striking angles; 22. a wiring board; 23. a push rod; 24. an armature; 25. an iron core; 26. a spring; 27. a skeleton; 28. a bracket; 29. a magnetism increasing member; 30. an insulating sleeve; 31. a limit structure; 32. a bending structure; 33. a second magnetic conduction plate; 34. and an exhaust hole.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In order that the above-recited objects, features and advantages of the present utility model will become more readily apparent, a more particular description of the utility model will be rendered by reference to the appended drawings and appended detailed description.

Referring to fig. 1 and 2, the present utility model provides a miniature circuit breaker comprising a housing 1 and a handle 2, a bent rod 3, a contact system 4, an electromagnetic system 5, an arc extinguishing chamber 12 and other electrically conductive components located within the housing 1. The handle 2 is in driving connection with the contact system 4 through the bent rod 3, and the contact system 4 is connected with the moving contact 15 and is used for driving the moving contact 15 to complete tripping or opening actions. And the handle 2 is shifted to drive the bent rod 3 and the contact system 4 to rotate, so that the opening and closing operation is completed. When overcurrent is generated or switching-off operation is performed, the contact system 4 can drive the moving contact 15 to complete tripping or switching-off action, and an arc is generated between the moving contact 15 and the fixed contact 18.

In the above embodiment, the electromagnetic system 5 includes the bracket 28, the wiring board 22, the coil 6, the fixed contact 18, the magnetism enhancing member 29, the insulating sleeve 30, and the trip unit. One end of the coil 6 is electrically connected with the wiring board 22, and the other end is electrically connected with the fixed contact 18, specifically, one end of the coil 6 is welded with the wiring board 22, and the other end is welded with the fixed contact 18; the magnetic enhancement piece 29 is made of ferromagnetic materials, is wrapped by an insulating sleeve 30, insulates the magnetic enhancement piece 29 from the coil 6, passes through the coil 6 together with the release, and is fixed by a bracket 28; the bracket 28 is made of high-temperature resistant insulating material, can fix the electromagnetic system 5 in the shell 1, and wraps the part above the silver point of the fixed contact 18 and the coil 6, and is isolated from the area where the electric arc is generated; the release consists of a framework 27, an iron core 25, an armature 24, a spring 26 and a push rod 23.

In the above embodiment, the ejector rod 23 and the frame 27 are made of insulating materials, the iron core 25 and the armature 24 are made of ferromagnetic materials, the iron core 25 is fixed in the frame 27, when overcurrent is generated, the iron core 25 attracts the armature 24 by the induced magnetic field, drives the ejector rod 23, pushes the trip button 16 in the contact 15 system, and trips the contact system 4 to complete the breaking action.

In the above embodiment, the skeleton 27 has a limiting structure 31, and may fix the magnetism enhancing member 29 and the insulating sleeve 30 in the electromagnetic system 5 together with the bracket 28.

In the above embodiment, the first magnetic conductive plate 13 and the second magnetic conductive plate 33 are respectively disposed on the housing 1 at two sides of the electromagnetic system 5, and the first magnetic conductive plate 13 and the second magnetic conductive plate 33 are made of ferromagnetic materials and are disposed at two sides of the electromagnetic system 5. The vertical plane parts of the first magnetic conduction plate 13 and the second magnetic conduction plate 33 are positioned in the area where the electric arcs are generated near the moving contact 15 and the fixed contact 18, the plane parts of the first magnetic conduction plate 13 and the second magnetic conduction plate 33 are isolated from the arc generating area by the cover plate 14, and the cover plate 14 is made of high-temperature resistant insulating materials. The upper parts of the first magnetic conduction plate 13 and the second magnetic conduction plate 33 are provided with bending structures 32, the first magnetic conduction plate 13 and the second magnetic conduction plate 33 which are arranged on two sides of the electromagnetic system 5 are respectively contacted with two ends of the magnetism increasing piece 29, and the bending structures 32 are insulated from the coil 6.

In the above embodiment, as shown in fig. 1 to 6, the arc extinguishing chamber 12 is disposed below the moving contact 15 and the fixed contact 18, and is composed of an arc extinguishing gate 20 and arc separating walls 19 on both sides of the arc extinguishing gate 20. The arc extinguishing bars 20 are vertically arranged and are arranged at an angle of 5-15 degrees with the horizontal direction, the shell 1 is provided with the air exhaust holes 34, a certain gap exists between the tail ends of the arc extinguishing bars 20 and the shell 1, and the closer the arc extinguishing bars 20 are to the air exhaust holes 34, the larger the gap is, so that high-temperature gas between the arc extinguishing bars 20 can conveniently move towards the air exhaust holes 34. The arc extinguishing grid plates 20 at the two ends of the arc extinguishing chamber 12 are provided with arc striking angles 21, and the arc striking angles 21 at the side of the fixed contact 18 are electrically connected with the fixed contact 18. The arc striking angle 21 at the side of the moving contact 15 is electrically connected with the moving contact 15 at the opening position or keeps a small distance, so that the arc can jump to the arc striking angle 21 from the moving contact 15 conveniently.

When an overcurrent occurs in the line or a critical load current is broken, an arc is generated between the moving and fixed contacts 18.

As shown in fig. 10, a schematic diagram of a magnetic field direction generated in a certain current direction is shown, wherein a solid line is a current direction F1, and a dotted line is an induced magnetic field direction F2. The induced magnetic field generated by the current is enhanced by the coil 6 and is gathered in the magnetism enhancing member 29, so that the magnetism enhancing member 29 which is originally not magnetic is converted into a ferromagnetic member with stronger magnetism, and the magnetic fields at the two ends of the magnetism enhancing member 29 form magnetic fields with the directions perpendicular to the arc path at the two sides of the arc through the conduction of the first magnetic conduction plate 13 and the second magnetic conduction plate 33 at the two ends of the magnetism enhancing member 29.

As shown in fig. 11, the arc moves in the direction of the arc extinguishing chamber 12 by the lorentz force generated by the induced magnetic field in fig. 10, and F3 in fig. 11 is the arc stress direction. When the current direction is opposite to the current direction shown in fig. 10, the lorentz force applied to the arc still makes the arc move toward the arc extinguishing chamber 12, and no description is repeated.

Therefore, even the induced magnetic field generated by the smaller critical load current is enhanced under the action of the coil 6, and the arc stress direction is towards the arc extinguishing chamber 12 regardless of the current direction, so that the enhanced magnetic blow effect without polarity is finally formed. The arc enters the arc extinguishing chamber 12 with increased capacity, is elongated under the action of the arc striking angle 21, is cut by the arc extinguishing grid plate 20, and the generated high-temperature gas is discharged from the exhaust hole 34, so that the effect of extinguishing the critical load current is achieved.

The present utility model is not limited to the conventional technical means known to those skilled in the art.

In the description of the present utility model, it should be understood that the terms "longitudinal," "transverse," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present utility model, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present utility model.

The above embodiments are only illustrative of the preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model, and various modifications and improvements made by those skilled in the art to the technical solutions of the present utility model should fall within the protection scope defined by the claims of the present utility model without departing from the design spirit of the present utility model.

Claims (10)

1. The miniature circuit breaker comprises a shell (1), wherein a fixed contact (18) and a moving contact (15) are arranged in the shell (1), and the moving contact (15) is in driving connection with a contact system (4), and is characterized in that an electromagnetic system (5) for driving the contact system (4) to act is further arranged in the shell (1), and the electromagnetic system (5) comprises a bracket (28), a wiring board (22), a coil (6), a magnetism increasing piece (29), a release and the fixed contact (18); one end of the coil (6) is electrically connected with the wiring board (22), and the other end of the coil is electrically connected with the fixed contact (18); the magnetism increasing piece (29) is made of ferromagnetic materials and is insulated from the coil (6), and the magnetism increasing piece (29) and the release pass through the coil (6) and are fixed by the bracket (28); the support (28) is made of high-temperature resistant insulating material, and can wrap the part above the silver point of the static contact (18) and the coil (6) and isolate the part from an arc generating area; the release acts to push the contact system (4) to finish breaking action.

2. The miniature circuit breaker of claim 1, wherein the trip unit includes a frame (27), a core (25), an armature (24), and a plunger (23); the ejector rod (23) and the framework (27) are made of insulating materials, and the iron core (25) and the armature (24) are made of ferromagnetic materials; the iron core (25) is fixed in the framework (27), and the armature (24) slides in the framework (27) and magnetically attracts the iron core (25) when current passes through; the ejector rod (23) penetrates through the center of the iron core (25) and slides, one end of the ejector rod is close to the contact system (4), and the other end of the ejector rod is connected with the armature (24).

3. Miniature circuit breaker according to claim 2, characterized in that the rod body of the plunger (23) between the core (25) and the armature (24) is sheathed with a spring (26).

4. Miniature circuit breaker according to claim 1, characterized in that the magnetizing element (29) is externally wrapped with an insulating sleeve (30).

5. The miniature circuit breaker according to claim 1, characterized in that the first magnetic conductive plate (13) and the second magnetic conductive plate (33) are respectively arranged on the shell (1) at two sides of the electromagnetic system (5), and the first magnetic conductive plate (13) and the second magnetic conductive plate (33) are respectively positioned at two sides of an area where the moving contact (15) and the fixed contact (18) generate electric arcs and are insulated and isolated from the area.

6. The miniature circuit breaker according to claim 5, characterized in that the upper positions of the first magnetic conductive plate (13) and the second magnetic conductive plate (33) are provided with bending structures (32), and the bending structures (32) of the first magnetic conductive plate (13) and the second magnetic conductive plate (33) are respectively contacted with two ends of the magnetism increasing piece (29) and are insulated from the coil (6).

7. The miniature circuit breaker according to claim 1, characterized in that an arc-extinguishing chamber (12) is arranged below the moving contact (15) and the fixed contact (18), a plurality of arc-extinguishing grid plates (20) which are linearly arranged at intervals are included in the arc-extinguishing chamber (12), each arc-extinguishing grid plate (20) is vertically arranged, and the linear arrangement direction of each arc-extinguishing grid plate (20) forms an included angle of 5-15 degrees with the horizontal direction.

8. The miniature circuit breaker according to claim 7, characterized in that the housing (1) has a vent hole (34), a gap is present between the end of the arc chute sheet (20) and the housing (1), and the closer the arc chute sheet (20) is to the vent hole (34), the larger the gap.

9. The miniature circuit breaker according to claim 1, characterized in that a handle (2) is rotatably connected to the housing (1), the contact system (4) is connected to the handle (2), and the handle (2) rotates to drive the contact system (4) to rotate, thereby completing the opening and closing action.

10. Miniature circuit breaker according to claim 9, characterized in that the contact system (4) is connected to the handle (2) by means of a bent rod (3).