WO2020248556A1

WO2020248556A1 - Novel double-contact point plastic case circuit breaker

Info

Publication number: WO2020248556A1
Application number: PCT/CN2019/125636
Authority: WO
Inventors: 吴学海; 金炼; 秦朝阳; 唐福礼
Original assignee: 江苏亚开电气有限公司
Priority date: 2019-06-11
Filing date: 2019-12-16
Publication date: 2020-12-17

Abstract

A novel double-contact point plastic case circuit breaker, relating to the field of circuit breakers and comprising: a movable contact (1) and stationary contacts (2) provided in a housing. The intermediate of the movable contact (1) is disposed on the housing by means of a rotating shaft. Movable contact points (1a) are provided on both ends of the movable contact (1). The two movable contact points (1a) are respectively provided on front and back surfaces of both ends of the movable contact (1). The housing is further accordingly provided with two stationary contacts (2). The two stationary contacts (2) are provided with stationary contact points (2a) corresponding to the movable contact points (1a). The stationary contacts (2) are processed into a U-shaped structure. The stationary contact points (2a) are provided on the end surface of the U-shaped structure. According to the double-contact point plastic case circuit breaker, by means of the measure of increasing contact breaks, each contact bears one-second voltage when the current is disconnected, which can reduce the breaking energy, improve the breaking index, reduce the free gas and arc particles generated during breaking, and can be applied in a low voltage circuit breaker.

Description

A new type of double-contact molded case circuit breaker

Technical field

The utility model relates to a circuit breaker, in particular to a plastic case circuit breaker.

Background technique

Low-voltage circuit breaker is a mechanical switching device widely used in low-voltage power distribution systems. It has short-circuit protection, overload protection and isolation functions. It is mainly suitable for infrequent conversion and in circuits with rated voltages not exceeding AC 1000V or DC 1500V. The motor does not start frequently. When the low-voltage circuit breaker cuts off the current, if the circuit voltage is not less than 10-20V and the current is not less than 80-100mA, an electric arc will be generated between the contacts of the electrical appliance, and the arc will be sucked into the arc extinguishing chamber to be cooled and extinguished, and there is a part of the arc Or ionized gas is ejected from the arc port on the power end of the circuit breaker to form an arc. In the product manual, the manufacturer will indicate the arcing distance of the product, that is, under the specified conditions, such as rated voltage and power factor, follow the specified procedures The arc flying distance when breaking the specified short-circuit current. When the arcing distance is zero, it is called zero arcing.

The arcing temperature is as high as thousands of degrees Celsius, and the arcing itself also has electrical conductivity, which causes serious harm. In the power industry, the arc sprayed by switch appliances may be directly sprayed on the grounded metal frame such as switch cabinets and power distribution panels, which will cause damage to metal conductors, abnormal surge voltages on lines, burns to operators, and equipment , Make the insulation aging and other conditions, such as short-circuit failure, explosion, and fire, threatening the safety of life and property. In petroleum, chemical, mining and other industries, it is necessary to pay attention to the hazards of arcing. In the design of low-voltage power distribution cabinets, the internal space is compressed in order to pursue a smaller size, which will increase the probability of internal arc faults. For example, in the new energy wind power system, the space in the converter cabinet and box transformer cabinet is limited, and arcing may be damaged Other equipment causes accidents. Due to safety requirements, some requirements are put forward for the arcing distance of low-voltage circuit breakers. The arcing distance is required to be short or zero arcing. Large arcing distances will inevitably lead to a large power distribution cabinet. This results in increased consumables and increased costs.

Utility model content

The purpose of the utility model is to provide a new type of double-contact plastic case circuit breaker, which reduces the breaking energy, improves the breaking index, and reduces the free gas and arc particles generated during breaking.

The purpose of the utility model is achieved as follows: a new type of double-contact plastic case circuit breaker, the package block is arranged in the movable contact and the static contact in the shell, and the middle of the movable contact is installed on the shell via a rotating shaft. Both ends of the moving contact are provided with moving contacts, and the two moving contacts are respectively arranged on the front and back sides of the two ends of the moving contact. The housing is also provided with two static contacts correspondingly. A static contact corresponding to the moving contact is arranged on the head, the static contact is processed with a U-shaped structure, and the static contact is arranged on the end surface of the U-shaped structure.

Compared with the prior art, the beneficial effect of the utility model is that the utility model adopts measures to increase the contact fracture; when the current is disconnected, each contact bears 1/2 voltage, the recovery voltage amplitude is low, and the medium recovery strength It is easy to exceed the recovery voltage increase, which can reduce the breaking energy, improve the breaking index, and reduce the free gas and arc particles generated during the breaking; the contact system is closed, which is equivalent to the sealing of the area behind the contact, and the gas pressure generated by the breaking can be used for rapid arc Enter the arc extinguishing chamber to achieve the effect of rapid arc extinguishing; at the same time, the static contact is designed into a U-shaped structure, and a U-shaped loop is formed on the static contact, which can make the current flow in the opposite direction when the dynamic and static contact circuits flow, increasing The electric repulsion between the moving and static contacts, because the current flows in the static conductive rod and the moving conductive rod in opposite directions, the loop force received by the moving contact is the upward repulsive force, plus the force caused by the current contraction, the moving contact The total electric repulsion received is the sum of the two. When there is a large current flowing through, the electric repulsion of the contact and the conductor is used to repel the contact as soon as possible. The contact repels before the overcurrent instantaneous release operates. It is expected that the fault circuit will be cut off before the short-circuit current reaches its peak value; at the same time, the current is forced to cross zero, leading to an arc, and the arc resistance suppresses the rise of the short-circuit current. The actual breaking current is very small. With the help of arc extinguishing measures, rapid arc extinguishing can be realized. The utility model can be used in low-voltage circuit breakers.

In order to further enhance the arc extinguishing performance, two sets of arc extinguishing grid plates are also arranged in the housing, and the two sets of arc extinguishing grid plates are arranged beside the movable contact and the static contact.

In order to further enhance the arc extinguishing performance, the two ends of the movable contact are processed with extension parts that cooperate with the arc extinguishing grid, and the extension part and the movable contact are bent at an angle.

Description of the drawings

Figure 1 is a schematic diagram of the structure of the utility model.

Among them, 1 moving contact, 1a moving contact, 1b extension, 2 static contact, 2a static contact, 3 arc extinguishing grid.

Detailed ways

As shown in Figure 1, a new type of double-contact molded case circuit breaker, the package block is set in the movable contact 1 and the static contact 2 in the shell, the middle of the movable contact 1 is installed on the shell via the rotating shaft, and the movable contact Both ends of 1 are provided with movable contacts 1a, and the two movable contacts 1a are respectively arranged on the front and back sides of the two ends of the movable contact 1. The housing is also provided with two static contacts 2 correspondingly, and the two static contacts 2 are provided The static contact 2a corresponding to the movable contact 1a, the static contact 2 is processed in a U-shaped structure, and the static contact 2a is arranged on the end surface of the U-shaped structure, and two sets of arc extinguishing grids 3 are arranged in the shell. The arc extinguishing grid 3 is arranged beside the movable contact 1 and the static contact 2. Both ends of the movable contact 1 are processed with extensions 1b that are matched with the arc extinguishing grid 3, between the extensions 1b and the movable contact 1. Bend at an angle.

The present utility model is not limited to the above-mentioned embodiments. On the basis of the technical solutions disclosed by the present utility model, those skilled in the art can make some of the technical features according to the disclosed technical content without creative work. Replacement and deformation, these replacements and deformations are all within the protection scope of the present invention.

Claims

A new type of double-contact plastic case circuit breaker. The movable contact and the static contact of the package block are arranged in the shell. It is characterized in that the middle part of the movable contact is installed on the shell via a rotating shaft. Both ends are provided with moving contacts, and the two moving contacts are respectively arranged on the front and back sides of the two ends of the moving contact. The housing is also provided with two static contacts corresponding to the two static contacts. A static contact corresponding to the moving contact, the static contact is processed with a U-shaped structure, and the static contact is arranged on the end surface of the U-shaped structure.
A new type of double-contact plastic case circuit breaker according to claim 1, characterized in that, two sets of arc extinguishing grids are further arranged in the housing, and the two sets of arc extinguishing grids are arranged on the moving contact and Static touch next to the head.
A new type of double-contact plastic case circuit breaker according to claim 2, characterized in that the two ends of the movable contact are processed with extensions that cooperate with the arc extinguishing grid.
A new type of double-contact molded case circuit breaker according to claim 3, wherein the extension part and the movable contact are bent at an angle.