CN215911378U

CN215911378U - Circuit breaker

Info

Publication number: CN215911378U
Application number: CN202121949664.4U
Authority: CN
Inventors: 内田凉太; 陈毅杰; 水野初男; 罗宪庆
Original assignee: Panasonic Eco Solutions Information Equipment Shanghai Co Ltd
Current assignee: Panasonic Eco Solutions Information Equipment Shanghai Co Ltd
Priority date: 2021-08-19
Filing date: 2021-08-19
Publication date: 2022-02-25
Anticipated expiration: 2031-08-19

Abstract

The utility model relates to the field of electrical equipment, and provides a circuit breaker which comprises a moving contact and a fixed contact, wherein the moving contact is formed by fixedly connecting a moving contact plate and a moving contact base, and the plate surface of the moving contact plate is opposite to the fixed contact. According to the circuit breaker, the movable contact is fixedly connected with the movable contact base through the movable contact board, on one hand, the movable contact board and the movable contact base can be manufactured separately, the board surface of the movable contact board can be made wider in the width direction, and the movable contact can be separated from the fixed contact more quickly to form open circuit when a loop is short-circuited; on the other hand, the movable contact plate and the movable contact base can be made of different materials, the heat conductivity of the movable contact base is lower than that of the movable contact plate, and therefore the phenomenon that when the movable contact is in contact with the fixed contact, heat of the fixed contact is transferred to the bimetallic strip by the movable contact to cause bending deformation of the bimetallic strip can be avoided, and misoperation of the circuit breaker can occur.

Description

Circuit breaker

Technical Field

The utility model relates to the field of electrical equipment, in particular to a circuit breaker.

Background

The circuit breaker is a device widely used in industrial production and daily life for protecting the safety of electricity utilization, and has the main function of timely cutting off current under the abnormal conditions of short circuit of a loop, current overload and the like, so that the damage of the abnormal current to each part and electrical elements in the loop is avoided, and the safety of electricity utilization is effectively improved.

The circuit breaker generally comprises a moving contact and a fixed contact, and when the moving contact is in contact with the fixed contact in a power-on state, a circuit is switched on to form a loop; when the moving contact is separated from the static contact, the circuit is disconnected to form an open circuit. When the load side loop is short-circuited, the current in the electric loop is increased instantly, the moving contact in the circuit breaker is opened, the power supply is cut off rapidly, and the safety of the electric loop is protected. When the moving contact is opened, an electric arc is generated at the position of the contact, and the electric arc generates electromagnetic repulsion to push the moving contact away.

The moving contact structure of a circuit breaker in the prior art is shown in fig. 1, and the moving contact is made of a metal plate, such as a copper plate, through a material removing process, and is an integrally formed structure. The moving contact comprises a terminal W for connecting a copper wire and a contact part C for contacting with a fixed contact. In order to increase the contact area of the contact portion C between the moving contact and the stationary contact, a method of spreading a material is generally used in the contact portion. If it is desired to further increase the area of the contact portion C due to the limitation of the processing technique, a copper plate having a thicker thickness needs to be selected, resulting in waste of material and an increase in cost.

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved by the utility model

The moving contact in the prior art is integrally processed, and due to the processing technology, the size of the plate surface of the moving contact plate in the width direction is limited, so that the contact area of the moving contact and the static contact is limited by the processing capacity. When the loop is short-circuited, the moving contact and the static contact are quickly opened, and electric arcs are generated between the contacts at the opening moment to generate electromagnetic force. The electromagnetic force acts on the surface of the moving contact, the larger the surface area of the moving contact is, the larger the electromagnetic force thrust is, and the breaking capacity of the circuit breaker can be improved by the increase of the surface area of the moving contact. By combining the factors, the problem that the breaking capacity of the circuit breaker is limited by the processing capacity of the moving contact needs to be solved.

Solution for solving the above technical problem

In order to solve the problems, the utility model provides a circuit breaker which comprises a moving contact and a fixed contact, wherein the moving contact comprises a moving contact plate and a moving contact base which are fixedly connected with each other, and the plate surface of the moving contact plate and the fixed contact are arranged oppositely.

According to the technical scheme, the movable contact adopts a processing technology of split manufacturing and then fixed connection, and the stress area of the movable contact can be increased as long as the area of the plate surface of the movable contact plate is increased, so that the area of the movable contact can be made larger without being limited by the thickness of the movable contact plate. When the circuit is short-circuited, the plate surface with larger area can be subjected to larger electromagnetic force, so that the movable contact is more easily separated from the fixed contact, the circuit breaker can be rapidly opened, the breaking capacity of the circuit breaker is improved, the large current is reduced when the short circuit occurs, the movable contact or other electrical elements are burnt and damaged, the temperature rise between the contacts after the short circuit is reduced, and the safety of the circuit breaker is improved.

Preferably, the moving contact board has a notch portion, and the moving contact base has a protrusion portion, and the notch portion is matched with the protrusion portion.

According to the technical scheme, the gap part is matched with the protruding part, so that the movable contact plate and the movable contact base can be fixedly connected more firmly. In addition, the matching of the notch part and the protruding part can also play a positioning effect, and the movable contact plate and the movable contact base are favorably installed and fixed.

Preferably, the movable contact board and the movable contact base are riveted with the bulge through the notch part in a matching mode.

According to the technical scheme, the parts can be fixedly connected in a riveting mode, the thermal deformation of the parts and the change of material properties are reduced while tight connection is guaranteed, and automatic processing is facilitated.

Preferably, the moving contact base is provided with a welding part, the welding part is fixedly connected with one end of the wire in a welding mode, and the moving contact base is made of a material different from that of the wire.

According to the technical scheme, the movable contact base and the lead are welded and fixed together, the movable contact base and the lead are made of different materials, when the movable contact base and the lead are welded, due to the fact that interfaces among the different materials have contact resistance, the contact resistance generates high temperature when welding current passes through, metal melt is formed on the contact surface of the two materials, the movable contact base and the lead are welded together in a fusion welding mode, the effect that scaling powder or welding rods are not added or directly welded is achieved, the use of the scaling powder or the welding rods is reduced while welding is facilitated, and cost reduction is facilitated.

Preferably, the circuit breaker further includes a bimetal, and the other end of the wire is connected to the bimetal.

According to the technical scheme, the bimetallic strip fixes two metal sheets with different thermal expansion coefficients together by utilizing the principle that metal expands with heat and contracts with cold. The increase in current causes the temperature to increase and the metal sheets with different coefficients of thermal expansion bend to different degrees. The bimetallic strip is bent to one side due to the increase of heat caused by continuous overload of current, the lock catch is pushed to open the linkage mechanism, the moving contact is separated from the static contact to form an open circuit, and the loop current is cut off, so that the purpose of protection is achieved.

Preferably, the moving contact plate is made of copper, and the moving contact base is made of iron.

According to the technical scheme, the moving contact base is made of copper materials, and the moving contact base is made of iron materials. Compared with a moving contact made of a copper material, the moving contact base made of an iron material has low heat conductivity, and heat generated by a contact part can be prevented from being transferred to the bimetallic strip through the moving contact, so that the deformation of the bimetallic strip is influenced, and the action performance of the circuit breaker is reduced. And through configuring the moving contact base into the lower iron material of heat conductivity, not only the cost is lower, has reduced the heat conduction to bimetallic strip department moreover, improves the performance of circuit breaker.

Preferably, the circuit breaker further comprises a wiring terminal, the wiring terminal comprises an incoming line terminal and an outgoing line terminal, and current flows out of the circuit breaker from the outgoing line terminal after entering the circuit breaker from the incoming line terminal.

Preferably, the material of the movable contact base has a lower thermal conductivity than the movable contact plate.

According to the technical scheme, the thermal conductivity of the material of the moving contact base is lower than that of the moving contact plate, so that heat is not easy to be transferred to the bimetallic strip through the moving contact base to interfere the action precision of the bimetallic strip, and the phenomenon that the bimetallic strip is bent and deformed to cause misoperation of the circuit breaker when the current does not reach the rated current-carrying capacity is avoided.

Preferably, the width of the movable contact board perpendicular to the movable contact board surface is larger than the thickness of the movable contact base.

According to the technical scheme, the width of the movable contact plate is larger than the thickness of the movable contact plate in the direction perpendicular to the plate surface of the movable contact plate, so that the movable contact structure can not be influenced by the plate thickness, the surface area of the movable contact is increased, the electromagnetic force borne by the movable contact is increased, and the breaking capacity of the circuit breaker is favorably improved.

Drawings

Fig. 1 is a schematic structural diagram of a movable contact of a circuit breaker in the prior art.

Fig. 2 is an internal structural view of the circuit breaker according to the embodiment of the present invention.

Fig. 3 is an exploded view of a movable contact according to an embodiment of the present invention.

Fig. 4 is a perspective view of a movable contact according to an embodiment of the present invention.

Description of the reference numerals

C a contact portion; a W terminal; 1 moving contact; 11 moving the contact plate; 111 a contact portion; 112 a notch part; 12 a moving contact base; 121 a boss; 122, welding part; 2, static contact; 3, conducting wires; 4, a bimetallic strip; 5, an arc extinguishing device; 6, a wiring terminal; 61 incoming line terminals; 62 an outlet terminal; 7 an electromagnetic solenoid; 8, a push rod is instantaneously moved; 9 a linkage mechanism; 10, locking and buckling; a width direction.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The utility model provides a circuit breaker, and fig. 2 is an internal structure diagram of the circuit breaker according to the embodiment of the utility model, and as shown in fig. 2, the circuit breaker comprises a moving contact 1 and a static contact 2, wherein current is allowed to pass through when the moving contact 1 is in contact with the static contact 2, and the current can be cut off to form an open circuit when the moving contact 1 is separated from the static contact 2. When the loop is short-circuited, the current is increased instantaneously, and the gas in the circuit breaker is ionized due to the action of thermionic emission and a strong electric field, so that electric arcs are generated at the contact positions of the moving contact 1 and the static contact 2. The electric arc between the moving contact 1 and the static contact 2 can generate electromagnetic force to push the moving contact 1.

Fig. 3 is an exploded view of the movable contact 1 according to the embodiment of the present invention, and as shown in fig. 2 and fig. 3, the movable contact 1 is formed by fixedly connecting a movable contact board 11 and a movable contact base 12. The plate surface of the moving contact plate 11 (i.e. the surface of the moving contact plate 11 perpendicular to the paper surface in fig. 2) is arranged opposite to the fixed contact 2.

Fig. 2 shows the internal structure of the circuit breaker when the movable contact board 11 and the fixed contact 2 are separated from each other, and when the circuit needs to be closed, the contact part 111 of the movable contact board 11 contacts with the fixed contact 2, completing the connection of the circuit.

In the prior art, since the movable contact plate 11 and the movable contact base 12 are integrally formed, the dimension of the movable contact plate 11 in the width direction a is limited by the thickness of the raw material metal plate due to the processing technology, and is limited by the material cost and the processing technology. The movable contact 1 in this embodiment adopts a split structure, so that the area or width of the contact portion 111 can be free from the requirements of material cost and processing technology, the contact portion 111 with a larger area or a wider width can provide stronger electromagnetic force, and when short circuit occurs, under the condition of generating equal energy, the movable contact 1 is stressed more, and the separation of the movable contact 1 is facilitated. The safety of the circuit breaker is improved.

The plate surfaces of the moving contact base 12 and the moving contact plate 11 can be perpendicular to each other, and the width d of the moving contact plate 11 perpendicular to the plate surface of the moving contact base 12 is larger than the thickness t of the moving contact base 12, so that the surface area of the moving contact 1 can be increased, the electromagnetic force borne by the moving contact 1 is increased, and the moving contact 1 and the static contact 2 are favorably separated when a loop is in short circuit.

Fig. 4 is a perspective view of the movable contact 1 according to the embodiment of the present invention, as shown in fig. 4, a contact portion 111 of the movable contact 1, which is used for contacting with the fixed contact 2, is a protruding structure that is bent and raised toward one side on the movable contact plate 11, and a shape of one end (a lower end in fig. 4) of the movable contact base 12 is matched with the contact portion 111, so that the movable contact base 12 and the contact portion 111 can be more closely attached and stably assembled, and the above-mentioned matching structure is favorable for ensuring that the connection structure of the movable contact plate 11 and the movable contact base 12 is stable and the conductivity is good.

The movable contact board 11 has a notch 112, the movable contact base 12 has a protrusion 121, and the notch 112 matches with the protrusion 121. In the present embodiment, the notch 112 and the protrusion 121 are matched to enable the movable contact board 11 and the movable contact base 12 to be fixedly connected more firmly. In addition, the matching between the notch 112 and the protrusion 121 can also play a positioning effect, which is beneficial to the installation and fixation of the movable contact board 11 and the movable contact base 12. In the present embodiment, the movable contact board 11 and the movable contact base 12 are caulked to the protrusion 121 through the notch 112. Compared with a welding fixing mode, the movable contact plate 11 and the movable contact base 12 are fixedly connected in a riveting mode, so that the close connection can be guaranteed, the thermal deformation of parts and the change of material properties can be reduced, and the automatic processing is facilitated.

The moving contact base 12 has a welding portion 122, the welding portion 122 is fixedly connected with one end of the wire 3 by welding, and the moving contact base 12 and the wire 3 are made of different materials. The lead 3 is a metal wire having conductive properties, and is generally made of copper. When the moving contact base 12 and the lead 3 are both made of copper materials, objects made of the same metal materials usually need to be added with soldering flux to achieve a good welding effect during welding, and the welding process is inconvenient and not beneficial to automatic production.

In this embodiment, the moving contact base 12 and the wire 3 are welded and fixed together by a spot welding process, because the moving contact base 12 is made of an iron material and the wire 3 is made of a copper material, contact resistance is generated at an interface where different metal materials are in contact with each other, and a large amount of heat is generated at the contact interface due to the existence of the contact resistance by welding current, so that the moving contact base 12 and the wire 3 are welded without fluxing agent.

In the present embodiment, the circuit breaker further includes a bimetal 4, and the lead 3 is connected to the bimetal 4. Current overload means that the loop current exceeds the rated current capacity, and when the current is overloaded, more heat is generated in the loop, and if the overload is continuously generated, the insulation part can be aged, and even the line can be burnt. By arranging the bimetallic strip 4 in the circuit breaker, the bimetallic strip 4 is deformed due to the increase of heat caused by current overload, and the lock catch 10 is pushed to open the linkage mechanism 9, so that the moving contact 1 is driven to be separated from the static contact 2, and an open circuit is formed to protect each part and electrical element of a loop.

In the present embodiment, the material of the movable contact base 12 has a lower thermal conductivity than the movable contact plate 11, specifically, the movable contact plate 11 is made of copper, and the movable contact base 12 is made of iron. The thermal conductivity of copper is 401W/(mK), and the thermal conductivity of iron is 80W/(mK). Compared with the moving contact 1 completely made of copper, the moving contact base 12 made of iron has lower heat conductivity, so that the heat generated by the contact part 111 can be reduced to be transferred to the bimetallic strip 4 through the moving contact base 12, the current in the bimetallic strip is prevented from being broken off prematurely when the current is far smaller than the rated current capacity, and the occurrence of misoperation of the circuit breaker is reduced.

In other embodiments of the present invention, the materials of the movable contact board 11 and the movable contact base 12 are not limited to copper and iron, and may be other materials, and it is only necessary that the material of the movable contact base 12 has a lower thermal conductivity than the movable contact board 11.

The circuit breaker further comprises an arc extinguishing device 5, in the embodiment, an arc is easily generated between the movable contact 1 and the fixed contact 2 during breaking, and the main function of the arc extinguishing device 5 is to eliminate the arc.

In addition, the circuit breaker further comprises a wiring terminal 6, the wiring terminal 6 comprises an incoming line terminal 61 and an outgoing line terminal 62, current enters the circuit breaker from the incoming line terminal 61 and then flows out of the circuit breaker from the outgoing line terminal 62, and the incoming line terminal 61 is connected with the bimetallic strip 4.

In the present embodiment, current enters the circuit breaker through the line inlet terminal 61, and the line inlet terminal 61 and the bimetal 4 are connected by a wire. The current reaches the moving contact 1 through the conducting wire 3 after passing through the bimetallic strip 4, and the moving contact 1 is contacted with the static contact 2 when the loop is conducted. Two ends of the coil winding of the electromagnetic solenoid 7 are respectively connected with the fixed contact 2 and the outlet terminal 62, and current flows to the electromagnetic solenoid 7 through the fixed contact 2, flows to the outlet terminal 62 through the electromagnetic solenoid 7 and finally flows out of the circuit breaker. When short circuit occurs, the current in the coil winding of the electromagnetic solenoid 7 is instantaneously increased to generate Lorentz force, so that the instantaneous push rod 8 acts to push the lock catch 10 to act, the linkage mechanism 9 is opened, and the static contact 2 and the moving contact 1 are driven to be separated.

Those of skill in the art will appreciate that the specific features of the various embodiments may be adaptively separated or combined. Such splitting or combining of specific features does not cause the technical solutions to deviate from the principle of the present invention, and therefore, the technical solutions after splitting or combining will fall within the protection scope of the present invention. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

So far, the technical solutions of the present invention have been described in connection with the embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the utility model, and the technical scheme after the changes or substitutions can fall into the protection scope of the utility model.

Claims

1. The circuit breaker comprises a moving contact and a fixed contact and is characterized in that the moving contact comprises a moving contact board and a moving contact base which are fixedly connected with each other, and the surface of the moving contact board is opposite to the fixed contact.

2. The circuit breaker of claim 1, wherein the movable contact plate has a cutout portion and the movable contact base has a protrusion portion, the cutout portion mating with the protrusion portion.

3. The circuit breaker of claim 2, wherein the movable contact plate and the movable contact base are matingly riveted to the boss through the notch.

4. The circuit breaker of claim 3, wherein the movable contact base has a weld fixedly connected to an end of a wire by welding, the movable contact base being formed of a different material than the wire.

5. The circuit breaker of claim 4, further comprising a bimetal, wherein the other end of the wire is connected to the bimetal.

6. The circuit breaker of claim 5, wherein the movable contact plate is made of copper and the movable contact base is made of iron.

7. The circuit breaker of claim 5 or 6, further comprising a terminal block, wherein the terminal block comprises an incoming terminal and an outgoing terminal, wherein current flows out of the circuit breaker from the outgoing terminal after entering the circuit breaker from the incoming terminal, and wherein the incoming terminal is connected to the bimetal.

8. The circuit breaker of any of claims 1-6, wherein the material of the movable contact base has a lower thermal conductivity than the movable contact plate.

9. The circuit breaker of any of claims 1-6, wherein a width of the movable contact plate in a direction perpendicular to a face of the movable contact base is greater than a thickness of the movable contact base.