A short circuit breaking structure for low voltage circuit breaker

Abstract

The invention discloses a short-circuit breaking structure for a low-voltage circuit breaker, comprising a moving contact support connected to the circuit breaker housing through a pin shaft, and a stationary contact fixed to the circuit breaker housing, a moving contact fixed to the moving contact support, an arc extinguishing cover, and a breaking bracket, a breaking action structure arranged on the breaking bracket, the breaking action structure comprising a disc, an action rib rod fixed to the edge of the disc, a conductive rib plate fixed to the edge of the disc, a conductive plate fixed to the conductive rib plate, the conductive plate connected to a power supply through a voltage stabilizer, a pull-in armature connected to the conductive plate fixed to the moving contact support, an electromagnet fixed to the conductive plate, the other end of the electromagnet electrically connected to the incoming line terminal on the moving contact support. The structure of the invention is reasonably arranged, and the moving contact and the stationary contact can be effectively and quickly tripped, which is beneficial to improving the current limiting performance and electrical life of the product, and has strong applicability and good practicality.

Description

Technical Field

[0001] The invention belongs to the technical field of low-voltage circuit breakers, and in particular relates to a short-circuit breaking structure for a low-voltage circuit breaker. Background Art

[0002] Miniature circuit breakers have the functions of connecting and disconnecting normal circuits and have overload protection and short-circuit protection, so they are widely used in low-voltage power distribution systems.

[0003] When a serious short circuit occurs in the power distribution system, a short-term impact current is caused, and a strong electric repulsion is generated between the moving and static contacts. The electric repulsion repels the moving contact and accelerates the arc generation, thereby playing a current limiting role. However, during use, when a serious short circuit occurs in the power distribution system, since the existing design structure only has the Lorentz force and Holm force between the moving and static contacts, it is impossible to quickly repel the moving contact, resulting in an increase in the short-circuit current and thus generating huge energy, which is not conducive to the circuit breaker extinguishing the arc and seriously affects the circuit breaker's breaking capacity, so the applicability and practicality are limited. Summary of the invention

[0004] The object of the present invention is to provide a short-circuit breaking structure for a low-voltage circuit breaker which has a reasonable structural arrangement and strong applicability.

[0005] The technical solution to achieve the purpose of the present invention is a short-circuit breaking structure for a low-voltage circuit breaker, comprising a moving contact support connected to a circuit breaker housing through a pin shaft, and a stationary contact fixed to the circuit breaker housing, a moving contact fixed to the moving contact support, and an arc extinguishing cover, characterized in that: it also includes a breaking bracket mounted on the circuit breaker housing, a breaking action structure is arranged on the breaking bracket, and the breaking action structure is connected to the moving contact support;

[0006] The breaking action structure comprises a disc, the center of which is connected to the circuit breaker housing through a shaft rod, an action rib rod is fixed on the edge of the disc, and the action rib rod is connected to the breaking bracket through an insulating cable;

[0007] A conductive rib is also fixed on the edge of the disk, a conductive plate is fixed on the conductive rib, and the conductive plate is connected to a power source through a voltage stabilizer;

[0008] A pull-in armature connected to the conductive plate is fixed on the movable contact support, an electromagnet is fixed on the conductive plate, and the other end of the electromagnet is electrically connected to the incoming line terminal on the movable contact support;

[0009] In normal use, the voltages at both ends of the electromagnet are the same. When there is a short circuit, there is a voltage difference at both ends of the electromagnet, which starts the electromagnet. The electromagnet and the attracting armature are attracted to drive the disc to rotate, and the moving contact support is driven by the insulating cable to separate the moving contact from the static contact.

[0010] It is further preferred that: a return spring is provided between the disc, the conductive rib plate and the circuit breaker housing;

[0011] The return spring and the electromagnet are arranged on symmetrical sides of the conductive rib plate.

[0012] It is further preferred that: a bearing is provided between the disc and the pin shaft, and the disc is a disc body made of insulating plastic material.

[0013] Further preferably, the end of the arc extinguishing cover is connected to the action rib rod through a connecting shaft;

[0014] A buffer spring is fixed between the middle part of the arc extinguishing cover and the edge of the disc.

[0015] It is further preferred that: an arc-shaped guide groove is provided on the circuit breaker housing;

[0016] A guide sliding block extending into the arc-shaped guide groove is fixed on the bottom surface of the disc.

[0017] It is further preferred that: a limit stopper is fixed on the circuit breaker housing;

[0018] The conductive rib plate is pressed against the side surface of the limit stopper to limit the position.

[0019] The present invention has positive effects: the structure of the present invention is reasonably arranged, and the moving contact and the static contact can be effectively and quickly tripped in the event of a short circuit, thereby ensuring the quickness of disconnection, being beneficial to improving the current limiting performance of the product and the electrical life of the product, and having strong applicability and good practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings, wherein:

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 It is a specific structural schematic diagram of the breaking action structure in the present invention;

[0023] Figure 3 It is a schematic diagram of the specific structure of the moving contact support and the moving contact in the present invention.

[0024] Figure numerals: pin shaft 1, moving contact support 2, static contact 3, moving contact 4, arc extinguishing cover 5, breaking bracket 6, breaking action structure 7, disc 71, shaft 72, action rib rod 73, insulating cable 74, conductive rib plate 75, conductive plate 76, voltage stabilizer 77, attracting armature 78, electromagnet 79, circuit breaker housing 8, reset spring 9, bearing 10, connecting shaft 11, buffer spring 12, arc guide groove 13, guide slider 14, limit block 15. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] See Figures 1 to 3 As shown, a short-circuit disconnecting structure for a low-voltage circuit breaker includes a moving contact support 2 connected to a circuit breaker housing 8 through a pin shaft 1, and a stationary contact 3 fixed to the circuit breaker housing, a moving contact 4 is fixed to the moving contact support 2, and an arc extinguishing cover 5 is also provided, and also includes a disconnecting bracket 6 installed on the circuit breaker housing, a disconnecting action structure 7 is provided on the disconnecting bracket, and the disconnecting action structure is connected to the moving contact support. In this embodiment, the disconnecting bracket is a conventional structure of the prior art, mainly used for supporting and connecting the disconnecting action structure, and the disconnecting action structure 7 includes a disc 71. In this embodiment, a bearing 10 is provided between the disc and the pin shaft, and the disc is an insulating plastic material disc. In addition, an arc-shaped guide groove 13 is provided on the circuit breaker housing, and a guide slider 14 extending into the arc-shaped guide groove is fixed on the bottom surface of the disc. The guide slider is guided in the arc-shaped guide groove to ensure its effectiveness and stability in use.

[0028] In actual application, the center of the disc is connected to the circuit breaker housing 8 through an axis rod 72, and an action rib rod 73 is fixed on the edge of the disc. The action rib rod is integrally formed or fixed by screws, and the action rib rod is connected to the disconnect bracket through an insulating cable 74. A conductive rib plate 75 is also fixed on the edge of the disc, and a conductive plate 76 is fixed on the conductive rib plate. The conductive plate is connected to the power supply through a voltage stabilizer 77. An attraction armature 78 connected to the conductive plate is fixed on the moving contact support, and an electromagnet 79 is fixed on the conductive plate. The other end of the electromagnet is electrically connected to the incoming line end on the moving contact support. The attraction armature cooperates with the electromagnet, and the attraction armature can be magnetically attracted when power is turned on to make the moving contact support move.

[0029] In this embodiment, a limit stopper 15 is fixed on the circuit breaker housing, and the conductive rib plate is pressed against the side of the limit stopper for limiting the position. The conductive rib plate can be limited to ensure stability and reliability in use.

[0030] There is a reset spring 9 between the disc, the conductive rib plate and the circuit breaker housing, and the reset spring and the electromagnet are arranged on the symmetrical sides of the conductive rib plate. It is provided with a reset spring, which can be reset to ensure the continuous reliability of subsequent operations.

[0031] Its working principle is briefly described as follows: in normal use, the voltages at both ends of the electromagnet are the same. When there is a short circuit, there is a voltage difference at both ends of the electromagnet, which starts the electromagnet. The electromagnet and the armature are attracted to drive the disc to rotate, and the moving contact support is driven by the insulating cable to separate the moving contact from the static contact.

[0032] The end of the arc extinguishing hood is connected to the actuating rib via a connecting shaft 11 , and a buffer spring 12 is fixed between the middle of the arc extinguishing hood and the edge of the disc.

[0033] The structure of the present invention is reasonably arranged, and the moving contact and the static contact can be effectively and quickly tripped in the event of a short circuit, thereby ensuring the quickness of disconnection, being beneficial to improving the current limiting performance of the product and the electrical life of the product, and having strong applicability and good practicality.

[0034] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural components recorded in the specification and the drawings can also be directly processed according to the existing technical common sense. At the same time, the connection method of each component adopts the mature conventional means in the prior art, and the machinery, parts and equipment all adopt the conventional models in the prior art, so no specific description will be given here.

[0035] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A short-circuit breaking structure for a low-voltage circuit breaker, comprising a moving contact support connected to a circuit breaker housing through a pin shaft, and a stationary contact fixed to the circuit breaker housing, a moving contact fixed to the moving contact support, and an arc extinguishing cover, characterized in that: It also includes a disconnecting bracket installed on the circuit breaker housing, on which a disconnecting action structure is arranged, and the disconnecting action structure is connected to the moving contact support; The breaking action structure comprises a disc, the center of which is connected to the circuit breaker housing through a shaft rod, an action rib rod is fixed on the edge of the disc, and the action rib rod is connected to the breaking bracket through an insulating cable; A conductive rib is also fixed on the edge of the disk, a conductive plate is fixed on the conductive rib, and the conductive plate is connected to a power source through a voltage stabilizer; A pull-in armature connected to the conductive plate is fixed on the movable contact support, an electromagnet is fixed on the conductive plate, and the other end of the electromagnet is electrically connected to the incoming line terminal on the movable contact support; In normal use, the voltages at both ends of the electromagnet are the same. When there is a short circuit, there is a voltage difference at both ends of the electromagnet, which starts the electromagnet. The electromagnet and the attracting armature are attracted to drive the disc to rotate, and the moving contact support is driven by the insulating cable to separate the moving contact from the static contact.

2. A short-circuit breaking structure for a low-voltage circuit breaker according to claim 1, characterized in that: A return spring is provided between the disc, the conductive rib plate and the circuit breaker housing; The return spring and the electromagnet are arranged on symmetrical sides of the conductive rib plate.

3. A short-circuit breaking structure for a low-voltage circuit breaker according to claim 2, characterized in that: A bearing is arranged between the disc and the pin shaft, and the disc is a disc body made of insulating plastic material.

4. The short-circuit breaking structure for a low-voltage circuit breaker according to claim 1, characterized in that: The end of the arc extinguishing cover is connected to the action rib rod through a connecting shaft; A buffer spring is fixed between the middle part of the arc extinguishing cover and the edge of the disc.

5. The short-circuit breaking structure for a low-voltage circuit breaker according to claim 1, characterized in that: An arc-shaped guide groove is provided on the circuit breaker housing; A guide sliding block extending into the arc-shaped guide groove is fixed on the bottom surface of the disc.

6. A short-circuit breaking structure for a low-voltage circuit breaker according to claim 1, characterized in that: A limit stopper is fixed on the circuit breaker housing; The conductive rib plate is pressed against the side surface of the limit stopper to limit the position.

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