Permanent magnet arc extinguishing structure of direct current contactor

Abstract

The utility model discloses a direct current contactor permanent magnet arc extinguishing structure, and relates to the technical field of direct current contactors, the direct current contactor permanent magnet arc extinguishing structure comprises a contactor body, a shell of the contactor body comprises a bottom shell and installation shells integrally formed at the two ends of the bottom shell, and a first magnet is arranged between the two installation shells; a second magnet is arranged on the side, away from the first magnet, of the installation shell, the polarities of the two adjacent ends of the first magnet and the second magnet are opposite, and a second limiting piece used for fixing the second magnet is further arranged on the installation shell. And a first limiting piece for fixing the first magnet is arranged between the two mounting shells. The problem that the arc extinguishing effect of the permanent magnet is reduced due to the fact that the permanent magnet is installed in the direct-current contactor and metal scraps generated when the direct-current contactor breaks current are adsorbed on the surface of the permanent magnet is solved.

Description

Technical Field

[0001] This application relates to the field of DC contactor technology, and in particular to a permanent magnet arc-extinguishing structure for a DC contactor. Background Technology

[0002] DC contactors are used to control DC circuits and are required to frequently switch on and off large load currents. During the switching process, the electrical contacts of a DC contactor discharge, generating an electric arc. This arc delays the circuit's opening, and high-energy arcs can even burn out the contacts, causing them to melt and weld. Since current DC contactors are sealed, this can even lead to fires and explosions in severe cases. Therefore, DC contactors must possess strong arc-extinguishing capabilities to safely switch on and off relatively large currents.

[0003] Chinese invention patent CN103515153B discloses a reliable arc-extinguishing non-polar high-voltage DC contactor arc extinguishing system. The system includes a sealed contact chamber and two permanent magnets. Two stationary contacts are fixedly mounted within the contact chamber, and two normally open moving contacts are movably mounted. The two moving contacts and the two stationary contacts are vertically aligned and matched. The permanent magnets are mounted on the extension line connecting the two stationary contacts, and their magnetic direction is non-perpendicular to the current direction between the moving and stationary contacts. The system utilizes the divergent horizontal component of the magnetic field lines at the contact point's cross-section, perpendicular to the arc current direction, to generate a magnetic blowing force with different directions on the arc at each different contact point. This disperses, elongates, and blows the concentrated or potentially superimposed arc towards a heat-dissipating metal grid. The heat dissipation area of ​​the metal grid rapidly reduces the temperature of the arc in contact with it, extinguishing it.

[0004] Regarding the aforementioned technologies, the inventors believe that since DC contactors generate an electric arc when interrupting current, the arc erodes the contacts and produces metal debris. Therefore, by installing permanent magnets inside the DC contactor, these metal debris will be attracted to the surface of the permanent magnets, causing changes in the magnetic field distribution of the permanent magnets, thereby affecting the magnetic properties of the permanent magnets and reducing their arc-extinguishing effect. Utility Model Content

[0005] To address the problem that installing permanent magnets inside a DC contactor causes metal debris generated during current interruption to adhere to the surface of the permanent magnet, thus reducing the arc-extinguishing effect of the permanent magnet, this application provides a permanent magnet arc-extinguishing structure for a DC contactor.

[0006] The permanent magnet arc-extinguishing structure for a DC contactor provided in this application adopts the following technical solution:

[0007] A permanent magnet arc extinguishing structure for a DC contactor includes a contactor body. The housing of the contactor body includes a bottom shell and mounting shells integrally formed at both ends of the bottom shell. A first magnet is disposed between the two mounting shells. A second magnet is disposed on the side of the mounting shell away from the first magnet, and the polarities of the adjacent ends of the first magnet and the second magnet are opposite. A second limiting member for fixing the second magnet is also disposed on the mounting shell, and a first limiting member for fixing the first magnet is disposed between the two mounting shells.

[0008] By adopting the above technical solution, a magnetic field is generated between the first magnet and the two second magnets. The electric arc is subjected to Lorentz force in the magnetic field. The Lorentz force will push the electric arc towards the inner wall of the bottom shell, causing the electric arc to be elongated, cooled and eventually extinguished, achieving the effect of rapid arc extinguishing. Considering that the metal debris generated by the arc erosion of the contact will be adsorbed onto the surface of the first magnet and the second magnet, the first magnet and the second magnet are installed on the outside of the DC contactor, which can improve the arc extinguishing effect of the DC contactor.

[0009] Optionally, the first limiting member is provided in a rectangular cylindrical shape, with an end cap at one end near the bottom shell and an open end at the other end. A groove is formed between the two mounting shells, and the first limiting member is embedded in the groove. The outer wall of the first limiting member abuts against the inner wall of the groove. A connecting member for stably installing the first limiting member in the groove is also provided between the first limiting member and the groove.

[0010] By adopting the above technical solution, the setting of the first limiting member embedded in the groove can reduce the additional space occupation, making the overall structure of the DC contactor more compact. The addition of the connecting member can also make the first limiting member more stably installed on the mounting shell.

[0011] Optionally, the connector is a metal block, which is bonded and fixed to the bottom wall of the groove, and can be attracted to the first magnet.

[0012] By adopting the above technical solution, the first limiting component can be quickly attracted and fixed on the mounting shell by magnetically connecting the metal block with the first magnet, which improves the stability of the structure and the convenience of installation.

[0013] Optionally, an anti-slip protrusion is fixedly provided on the outer side of the opening end of the first limiting member.

[0014] By adopting the above technical solution, the anti-slip protrusions can enhance the friction of the contact surface, provide a better grip point, and make it more convenient and faster to install and remove the first limiting component.

[0015] Optionally, the second limiting member includes a first shell for mounting the second magnet and a second shell integrally formed at both ends of the first shell, the second shell being sleeved on the outside of the mounting shell.

[0016] By adopting the above technical solution, the integral molding of the second shell improves the overall structural stability of the second limiting component and simplifies the assembly process of the second limiting component.

[0017] Optionally, the outer side of the second limiting member is provided with a number of heat dissipation holes at even intervals.

[0018] By adopting the above technical solution, the setting of heat dissipation holes can increase the surface area of ​​the second limiting member and increase the contact area with air. Therefore, the heat generated by the electric arc can be quickly dissipated through the heat dissipation holes, which can not only improve the efficiency of heat dissipation, but also help improve the durability and stability of the DC contactor.

[0019] Optionally, a positioning protrusion is fixed on the outer side of the mounting shell near the first limiting member, and a positioning groove is provided on the outer side of the first limiting member, with the positioning protrusion abutting and fixed to the positioning groove.

[0020] By adopting the above technical solution, the positioning groove and the positioning protrusion are fixed in contact, which can ensure the precise alignment of the first limiting member on the mounting shell. At the same time, it can also ensure that the first limiting member can maintain a stable installation state when subjected to external force, thereby enhancing the connection stability between the first limiting member and the mounting shell.

[0021] Optionally, the edges of the bottom shell and the mounting shell are arranged in an arc shape.

[0022] By adopting the above technical solution, the arc-shaped edge design can reduce safety accidents caused by scratches from sharp edges, making the DC contactor safer during gripping.

[0023] In summary, this application includes at least one of the following beneficial technical effects:

[0024] 1. A magnetic field is generated between the first magnet and the two second magnets. The electric arc is subjected to the Lorentz force in the magnetic field. The Lorentz force will push the electric arc towards the inner wall of the bottom shell, causing the electric arc to be elongated, cooled and eventually extinguished, achieving the effect of rapid arc extinguishing. Considering that the metal debris generated by the arc erosion of the contact will be attracted to the surface of the first magnet and the second magnet, the first magnet and the second magnet are installed on the outside of the DC contactor, which can improve the arc extinguishing effect of the DC contactor.

[0025] 2. The method of magnetically connecting the metal block with the first magnet allows the first limiting component to be quickly attracted and fixed on the mounting shell, improving the stability of the structure and the ease of installation;

[0026] 3. The anti-slip protrusions enhance the friction of the contact surface, providing a better grip and making it easier and faster to install or remove the first limiter. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of the permanent magnet arc extinguishing structure of the DC contactor in Embodiment 1 of this application.

[0029] Figure 2 This is a cross-sectional schematic diagram of the permanent magnet arc-extinguishing structure of the DC contactor in Embodiment 1 of this application.

[0030] Figure 3 This is a schematic diagram of the internal structure of the housing of the contactor body in Embodiment 1 of this application.

[0031] Figure 4 This is a schematic diagram of the heat dissipation hole structure in Embodiment 2 of this application.

[0032] Figure 5 This is a schematic diagram of the positioning protrusion and positioning groove in Embodiment 3 of this application.

[0033] Reference numerals in the attached drawings: 1. Contactor body; 2. Housing; 3. Bottom housing; 4. Mounting housing; 5. First magnet; 6. Second magnet; 7. Second limiting member; 8. First limiting member; 9. End cap; 10. Groove; 11. Connector; 12. Anti-slip protrusion; 13. First shell; 14. Second shell; 15. Heat dissipation hole; 16. Positioning protrusion; 17. Positioning groove; 18. Conductive base; 19. Moving iron core; 20. Connecting rod. Detailed Implementation

[0034] The following is combined with Figure 1-5 This application is described in further detail.

[0035] This application discloses a permanent magnet arc-extinguishing structure for a DC contactor.

[0036] Example 1

[0037] Reference Figure 1The permanent magnet arc-extinguishing structure of the DC contactor includes a contactor body 1, and the housing 2 of the contactor body 1 includes a bottom shell 3 and two mounting shells 4. Both mounting shells 4 are convex in shape and are integrally formed at both ends of the bottom shell 3. The housing 2 of the contactor body 1 is made of a plastic material with good insulation properties. To prevent safety accidents caused by sharp edges, the edges of the bottom shell 3 and the mounting shells 4 are rounded, which also makes them easier to handle. A groove 10 is provided at one end of the two mounting shells 4 that is close to each other, facilitating the installation of other components.

[0038] Reference Figure 1 To prevent metal debris generated by arc erosion from adhering to the surfaces of magnets 5 and 6, thus reducing the arc-extinguishing effect, this embodiment mounts the first magnet 5 and the second magnet 6 outside the housing 2, using the generated magnetic field for rapid arc extinguishing. The first magnet 5 is positioned between the two mounting shells 4, and the second magnet 6 is positioned on the side of the mounting shell 4 furthest from the first magnet 5; two second magnets 6 are provided. The adjacent ends of the first magnet 5 and the second magnet 6 have opposite polarities. Both the first magnet 5 and the second magnet 6 are permanent magnets, which maintain their magnetism over a long period, providing a continuous magnetic field. The first magnet 5 and the second magnet 6 are the same size and both are square in shape. A magnetic field is generated between the first magnet 5 and the two second magnets 6. The arc is subjected to a Lorentz force in this magnetic field, which pushes the arc towards the inner wall of the bottom shell 3, causing the arc to be elongated, cooled, and eventually extinguished, thus achieving a rapid arc-extinguishing effect.

[0039] Reference Figure 1 In order to fix the first magnet 5 and the second magnet 6 on the contactor body 1, this embodiment provides a first limiting member 8 and a second limiting member 7 on the mounting shell 4. The first limiting member 8 fixes the first magnet 5, and the second limiting member 7 fixes the second magnet 6.

[0040] Reference Figure 1 and Figure 2 The first limiting member 8 is disposed between the two mounting shells 4. The first limiting member 8 is rectangular and made of plastic. The interior of the first limiting member 8 is hollow. The end of the first limiting member 8 away from the bottom shell 3 is open, and the end of the first limiting member 8 near the bottom shell 3 is provided with an end cap 9. Considering that it is more convenient and quick to install or remove the first limiting member 8, a strip-shaped anti-slip protrusion 12 is fixedly provided on the outer side of the open end of the first limiting member 8 to provide a better grip by increasing the friction of the contact surface. The first limiting member 8 is embedded in the groove 10, and the outer wall of the first limiting member 8 abuts against the inner wall of the groove 10. A connector 11 is glued to the bottom wall of the groove 10. The connector 11 is made of metal. The first limiting member 8 is quickly attracted and fixed to the mounting shell 4 by magnetic attraction between the connector 11 and the first magnet 5.

[0041] Reference Figure 1 The second limiting member 7 is located at the end of the mounting shell 4 away from the groove 10. The second limiting member 7 is convex in shape and includes a first shell 13 and a second shell 14. The first shell 13 is used to mount the second magnet 6, while the second shell 14 is integrally formed at both ends of the first shell 13. The second shell 14 is sleeved on the outside of the mounting shell 4 and is bonded and fixed to the mounting shell 4. The integrally formed design of the second shell 14 simplifies the assembly process of the second limiting member 7.

[0042] Reference Figure 2 and Figure 3 Two conductive seats 18 are fixedly mounted on the side of the contactor body 1 near the mounting housing 4. Both conductive seats 18 are cylindrical. Two moving iron cores 19 are disposed inside the mounting housing 4, and the two conductive seats 18 extend into the mounting housing 4 to cooperate with the two moving iron cores 19. A connecting rod 20 is provided at the end of each moving iron core 19 away from the conductive seats 18. Both moving iron cores 19 are snapped and fixed onto the connecting rod 20, ensuring that the two moving iron cores 19 can move synchronously, allowing them to simultaneously engage with or disengage from the conductive seats 18. When the DC contactor circuit is turned on, the moving iron core 19 slides towards the conductive seats 18 and engages with them. When the DC contactor circuit is turned off, the moving iron core 19 disengages from the conductive seats 18 and slides away from them.

[0043] The implementation principle of the permanent magnet arc extinguishing structure of a DC contactor in this application embodiment is as follows: When the DC contactor circuit is turned on, the moving iron core 19 slides towards the conductive base 18 and attracts the conductive base 18. When the DC contactor circuit is de-energized, the moving iron core 19 will detach from the conductive base 18 and slide away from the conductive base 18. A large number of electric arcs will be generated at the moment of de-energization, and a magnetic field will be generated between the first magnet 5 and the second magnet 6. The electric arc is subjected to the Lorentz force in the magnetic field. The Lorentz force pushes the electric arc towards the inner wall of the bottom shell 3, causing the electric arc to be stretched, cooled and finally extinguished, thereby achieving the effect of rapid arc extinguishing and improving the arc extinguishing capability of the DC contactor.

[0044] Example 2

[0045] Reference Figure 4 The difference between this embodiment and embodiment 1 is that: since the heat generated by the electric arc can cause thermal damage to the internal components and affect the performance of the components, a number of heat dissipation holes 15 are evenly spaced on the outer side of the second limiting member 7. The heat dissipation holes 15 are arranged in a strip shape, which can increase the surface area of ​​the second limiting member 7 and increase the contact area with the air, so that the heat generated by the electric arc can be dissipated quickly.

[0046] The implementation principle of the permanent magnet arc extinguishing structure of a DC contactor in this application embodiment is as follows: When the DC contactor circuit is de-energized, an electric arc will be generated, and the electric arc will generate a large amount of heat. At this time, the heat is quickly dissipated into the outside air through the heat dissipation hole 15, thereby accelerating the heat dissipation efficiency.

[0047] Example 3

[0048] Reference Figure 5 The difference between this embodiment and embodiment 1 is that, in order to fix the first limiting member 8 on the mounting shell 4, a positioning groove 17 is provided on the outer side of the first limiting member 8, and a positioning protrusion 16 is fixed on the outer side of the mounting shell 4 near the first limiting member 8. The positioning groove 17 and the positioning protrusion 16 abut and fix each other, which can not only achieve precise alignment between the first limiting member 8 and the mounting shell 4, but also prevent the first limiting member 8 from sliding relative to each other under the action of external force, thus ensuring the connection stability of the first limiting member 8.

[0049] The implementation principle of the permanent magnet arc extinguishing structure of a DC contactor in this application embodiment is as follows: when the first limiting member 8 is installed on the mounting shell 4, the positioning groove 17 and the positioning protrusion 16 abut and fix, and the first limiting member 8 and the mounting shell 4 can be quickly and accurately aligned.

[0050] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0051] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A permanent magnet arc-extinguishing structure for a DC contactor, comprising a contactor body (1), characterized in that: The housing (2) of the contactor body (1) includes a bottom shell (3) and mounting shells (4) integrally formed at both ends of the bottom shell (3). A first magnet (5) is disposed between the two mounting shells (4). A second magnet (6) is disposed on the side of the mounting shell (4) away from the first magnet (5). The polarities of the two adjacent ends of the first magnet (5) and the second magnet (6) are opposite. A second limiting member (7) for fixing the second magnet (6) is also disposed on the mounting shell (4). A first limiting member (8) for fixing the first magnet (5) is disposed between the two mounting shells (4).

2. The permanent magnet arc-extinguishing structure for a DC contactor according to claim 1, characterized in that: The first limiting member (8) is arranged in a rectangular cylindrical shape. One end of the first limiting member (8) near the bottom shell (3) is provided with an end cap (9), and the other end is open. A groove (10) is formed between the two mounting shells (4). The first limiting member (8) is embedded in the groove (10), and the outer wall of the first limiting member (8) abuts against the inner wall of the groove (10). A connecting member (11) for stably installing the first limiting member (8) in the groove (10) is also provided between the first limiting member (8) and the groove (10).

3. The permanent magnet arc-extinguishing structure for a DC contactor according to claim 2, characterized in that: The connector (11) is a metal block, which is bonded and fixed to the bottom wall of the groove (10). The connector (11) can be attracted to the first magnet (5).

4. The permanent magnet arc-extinguishing structure for a DC contactor according to claim 2, characterized in that: The first limiting member (8) has an anti-slip protrusion (12) fixedly provided on the outer side of the opening end.

5. The permanent magnet arc-extinguishing structure for a DC contactor according to claim 2, characterized in that: The second limiting member (7) includes a first shell (13) for mounting the second magnet (6) and a second shell (14) integrally formed at both ends of the first shell (13), the second shell (14) being sleeved on the outside of the mounting shell (4).

6. The permanent magnet arc-extinguishing structure for a DC contactor according to claim 1, characterized in that: The outer side of the second limiting member (7) is provided with a number of heat dissipation holes (15) at even intervals.

7. The permanent magnet arc-extinguishing structure for a DC contactor according to claim 1, characterized in that: The mounting shell (4) has a positioning protrusion (16) fixed on the outer side near the first limiting member (8), and a positioning groove (17) is provided on the outer side of the first limiting member (8). The positioning protrusion (16) and the positioning groove (17) are abutted and fixed.

8. The permanent magnet arc-extinguishing structure for a DC contactor according to claim 1, characterized in that: The edges of the bottom shell (3) and the mounting shell (4) are arranged in an arc shape.

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