A DC circuit breaker static contact device with non-polarity magnetic blowout

Abstract

A DC circuit breaker static contact device with non-polarity magnetic blowout changes the traditional permanent magnet installation scheme. An insulating seat is installed in the cavity in the middle of the static contact, an arc contact is installed in the insulating seat, an arc-starting piece is riveted into the slot of the arc contact, the arc contact and the static contact are fixed with screws and insulating sleeves, the static contact and the arc contact are insulated from each other, a coil is symmetrically installed at both ends of the static contact, and finally the static contact device is securely fixed to the rear base plate by screws. The present invention eliminates the influence of the polarity of the DC current by removing the permanent magnet design, and when the moving and static contacts of the DC circuit breaker disconnect and an arc is generated, the arc is stably and rapidly moved to the arc extinguishing chamber by the magnetic field force under the action of the magnetic field generated by the coil to extinguish the arc, thereby improving the stability of the arc extinguishing, avoiding the circuit breaker from burning when opening, realizing the non-polarity opening of the DC circuit breaker, and improving the breaking capacity of the DC circuit breaker. The device has stable and reliable performance, a simple structure, a low failure rate, and an extended service life.

Description

Technical Field

[0001] The present invention relates to the field of low-voltage electrical components and equipment, and in particular to a DC circuit breaker static contact device with non-polarity magnetic blowout. Background Art

[0002] The primary function of a DC universal circuit breaker in a power distribution line is to connect and disconnect the circuit under normal and abnormal (overload or short-circuit) conditions. When a short-circuit fault occurs in the line, the circuit breaker contacts should quickly operate to disconnect the main circuit to prevent equipment damage. As is well known in the industry, when the moving contacts of a circuit breaker open while carrying current, an arc is generated. Since a DC power source, unlike an AC power source, does not have a natural zero-crossing point, extinguishing the arc with DC power is more difficult than with AC power. Especially at low rated currents, insufficient electric force can cause the arc to rise more slowly into the arc extinguishing chamber, or the arc may not rise and continue to burn between the contacts. In mild cases, this can cause the product contacts to burn, reducing the electrical lifespan; in severe cases, the product can burn out, causing a fire.

[0003] To address the above issues, Chinese patent application number CN209766345U discloses an arc extinguishing system for a DC circuit breaker. The system comprises a static contact, an arc extinguishing hood mounted on the static contact, and a movable contact that cooperates with an operating mechanism and rotates relative to the static contact. The arc extinguishing hood is provided with at least one bar-shaped permanent magnet at the static contact point corresponding to the static contact. The bar-shaped permanent magnet is disposed transversely through the arc extinguishing hood, and its magnetic flux lines are perpendicular to the plane formed by the moving contact's opening and closing motions. This system has the advantages of a simple structure, stable and reliable performance, good arc extinguishing effect, high interruption rate, and long service life.

[0004] For example, Chinese patent publication number CN212695109U discloses an arc extinguishing system for a DC circuit breaker, comprising an arc extinguishing chamber disposed on one side of the contact mechanism of the circuit breaker, two first magnetic conductive plates disposed opposite each other on one side of the arc extinguishing chamber, an arc striking chamber formed between the two first magnetic conductive plates, a moving contact and a static contact of the contact mechanism opening and closing in the arc striking chamber, the static contact being located on one side of the arc striking chamber and fixed above the arc extinguishing chamber, an arc striking angle being provided on the other side of the arc striking chamber, the arc striking angle being located below the moving contact, and the spacing between at least the portions of the two first magnetic conductive plates proximate the arc extinguishing chamber being smaller than the spacing away from the arc extinguishing chamber. In the arc extinguishing system for a DC circuit breaker of the present invention, the spacing between at least the portions of the two first magnetic conductive plates proximate the arc extinguishing chamber being smaller than the spacing away from the arc extinguishing chamber, thereby enhancing the magnetic field strength of the arc striking chamber, enabling the arc to quickly enter the arc extinguishing chamber along the arc striking angle and extinguish, reducing the arc stagnation time on the static contact, thereby alleviating the degree of static contact burnout, and achieving low cost.

[0005] At present, the above patents still have certain shortcomings in actual operation: the above two existing technologies both enhance the magnetic field strength between the moving and static contacts, so that the arc enters the arc extinguishing chamber under low current conditions. However, this solution has the following disadvantages: 1. The magnetism of permanent magnets may weaken when they are exposed to a strong electromagnetic environment for a long time, affecting the low current breaking capacity. 2. Permanent magnets have N / S polarity, and the polarity installation must be consistent with the current direction between the moving and static contacts. The installation and matching are cumbersome, and if installed incorrectly, the arc will be suppressed, which is counterproductive. The existing technology still needs to be improved. Invention content

[0006] In view of the deficiencies in the prior art, the present invention provides a DC circuit breaker static contact device with non-polarity magnetic blowout to solve the above problems.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A DC circuit breaker static contact device with non-polarity magnetic blowout includes a static contact, an insulating base, an arcing contact, a coil, an arcing plate, a rear base, and a coil cover. The static contact is connected to the insulating base at one end and to the rear base at the other end. The arcing contact is located on the other side of the insulating base and is connected to the insulating base. The arcing plate is connected to the arcing contact at one end and to the rear base at the other end. The coil is connected to the arcing contact at one end and to the static contact at the other end. The coil cover is located above the coil.

[0009] Furthermore, a cavity is designed in the middle of the static contact, and an insulating seat is installed in the cavity.

[0010] Furthermore, both ends of the static contact are fixed to the rear base plate by screws.

[0011] Furthermore, an arc contact is installed in the insulating seat.

[0012] Furthermore, the arc contact is provided with a slot, and the arc striking piece is inserted into the arc contact slot and riveted.

[0013] Furthermore, the arcing contact and the static contact are fixed by means of screws and insulating sleeves.

[0014] Furthermore, the coil includes a left coil and a right coil, and the left and right coils are symmetrically designed.

[0015] Furthermore, one end of the coil is fixed to the arcing contact by a screw.

[0016] Furthermore, the other end of the coil is fixed to the static contact by a screw.

[0017] Furthermore, a coil cover is designed above the coil.

[0018] Compared with the prior art, the beneficial effects of the device of the present invention are: a DC circuit breaker static contact device with non-polarity magnetic blowing, which changes the traditional permanent magnet installation scheme, an insulating seat is installed in the cavity in the middle of the static contact, an arc contact is installed in the insulating seat, and the arc striking piece is riveted in the slot of the arc contact. The arc contact and the static contact are fixed with screws and insulating sleeves, the static contact and the arc contact are insulated from each other, the coil is symmetrically installed at both ends of the static contact, and finally the static contact device is reliably fixed to the rear base plate by screws. The permanent magnet design of the present invention eliminates the influence of the polarity of the DC current. When the moving and static contacts of the DC circuit breaker are disconnected and an arc is generated, the arc is stably and rapidly moved to the arc extinguishing chamber under the action of the magnetic field generated by the coil and extinguished by the magnetic field force, thereby improving the stability of the arc extinguishing, avoiding the circuit breaker from burning when opening, realizing the non-polarity opening of the DC circuit breaker, and improving the breaking capacity of the DC circuit breaker. The device has stable and reliable performance, simple structure, low failure rate, and extended service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the assembly of a DC circuit breaker static contact device with non-polarity magnetic blowout according to the present invention;

[0020] Figure 2 This is a simplified structural diagram of a DC circuit breaker static contact with non-polarity magnetic blowout according to the present invention;

[0021] Figure 3 This is a front view of a static contact of a DC circuit breaker with non-polarity magnetic blowout according to the present invention;

[0022] Figure 4 This is a cross-sectional view of a static contact of a DC circuit breaker with non-polarity magnetic blowout according to the present invention;

[0023] Figure 5 This is a structural diagram of the static contact and the moving contact of a DC circuit breaker with non-polarity magnetic blowout according to the present invention;

[0024] Figure 6 The present invention is a schematic diagram of the working principle of the static contact and the moving contact of a DC circuit breaker with non-polarity magnetic blowout. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0026] The present invention provides a technical solution: a DC circuit breaker static contact device with non-polarity magnetic blowout, comprising a static contact 1, an insulating seat 2, an arc contact 3, a coil 4, an arc-starting piece 5, a rear base plate 6, and a coil cover 7. The processing process is as follows:

[0027] Install the arc-striking piece 5: slot the arc-striking piece 5, and set prefabricated holes in the slot and on the arc contact 3. Insert the arc-striking piece 5 into the slot of the arc contact 3, pass the rivet through the prefabricated holes of the arc-striking piece 5 and the arc contact 3, and rivet the arc-striking piece 5 and the arc contact 3.

[0028] Install the static contact 1, insulating seat 2 and arcing contact 3: Install the insulating seat 2 in the cavity of the static contact 1, install the arcing contact 3 in the insulating seat 2, fix the arcing contact 3 and the static contact 1 with screws and insulating sleeves, and separate the arcing contact 3 from the static contact 1 with the insulating seat 2, so that the static contact 1 and the arcing contact 3 are insulated from each other. Figure 4 shown.

[0029] Install coil 4: Coil 4 consists of two coils, left and right, which are symmetrically distributed. One end of coil 4 is fixed to arc contact 3 by screws, and the other end is fixed to static contact 1 by screws. Figure 3 shown.

[0030] Overall assembly: Fix the static contact 1 to the rear base plate 6 with screws, fix the screws through the holes above the arc-starting piece 5 to the rear base plate 6, and clamp the coil cover 7 on the top of the coil 4.

[0031] The present invention provides a DC circuit breaker static contact device with non-polarity magnetic blowout, which, together with the operating mechanism, the moving contact 8 and other components, constitutes a DC circuit breaker with non-polarity magnetic blowout. Figure 5 As shown in the figure, when the moving contact 8 opens to interrupt a small current, the current I enters the static contact 1 from the upper end, then flows through the coil 4 to the arcing contact 3, and then reaches the moving contact 8 through the arc between the arcing contact 3 and the moving contact 8. When the current I flows through the coil, an inward magnetic field B is generated. The arc is subjected to a vertical upward force F in the magnetic field. Under the action of the force F, the arc quickly enters the arc extinguishing chamber area above and extinguishes the arc, as shown in the figure. Figure 6 As shown in the figure. When the direction of current I reverses, the current flowing through the coil in circuit I reverses, generating an outward magnetic field B. The direction of the magnetic field force F on the arc remains vertically upward. Under the action of the force F, the arc quickly enters the arc extinguishing chamber area above and extinguishes, regardless of the current direction.

[0032] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A DC circuit breaker static contact device with non-polarity magnetic blowout, characterized in that: The invention comprises a static contact (1), an insulating seat (2), an arc contact (3), a coil (4), an arc striking piece (5), a rear bottom plate (6) and a coil cover (7), wherein one end of the static contact (1) is connected to the insulating seat (2) and the other end is connected to the rear bottom plate (6), the arc contact (3) is located on the other side of the insulating seat (2) and is connected to the insulating seat (2), one end of the arc striking piece (5) is connected to the arc contact (3) and the other end is connected to the rear bottom plate (6), the coil (4) is connected to the arc contact (3) at one end and the other end is connected to the static contact (1), and the arc contact (3) is located on the other side of the insulating seat (2) and is connected to the insulating seat (2), the arc striking piece (5) is connected to the arc contact (3) at one end and the other end is connected to the rear bottom plate (6), the coil (4) is connected to the arc contact (3) at one end and the other end is connected to the static contact (1), and the arc contact (3) is located on the other side of the insulating seat (2) and is connected to the insulating seat (2). The coil cover (7) is located above the coil (4). A cavity is designed in the middle of the static contact (1), and an insulating seat (2) is installed in the cavity. Both ends of the static contact (1) are fixed to the rear bottom plate (6) by screws. An arc contact (3) is installed in the insulating seat (2). The arc contact (3) is provided with a slot. The arc striking piece (5) is inserted into the slot of the arc contact (3) and riveted. The arc contact (3) and the static contact (1) are fixed by screws and insulating sleeves. The coil (4) includes a left coil and a right coil, and the left coil and the right coil are symmetrically designed.

2. A DC circuit breaker static contact device with non-polarity magnetic blowout according to claim 1, characterized in that: One end of the coil (4) is fixed to the arc contact (3) via a screw.

3. A DC circuit breaker static contact device with non-polarity magnetic blowout according to claim 2, characterized in that: The other end of the coil (4) is fixed to the static contact (1) by means of screws.

4. A DC circuit breaker static contact device with non-polarity magnetic blowout according to claim 3, characterized in that: A coil cover (7) is designed above the coil (4).

Images