Terminal cover of molded case circuit breaker and circuit breaker structure

Abstract

The present invention discloses a terminal cover of a molded case circuit breaker, characterized in that it comprises: a cover body; a cover body having an opening structure at one end, and having a first cavity, a second cavity and a third cavity connected in sequence; an opening structure, which is arranged in an outer slot of a terminal outside the molded case circuit breaker, and covers the air outlet of an arc extinguishing chamber; the first cavity is connected to the opening structure; the volume of the second cavity is smaller than the volume of the first cavity and the third cavity; a plurality of vents are provided on the cavity wall of the third cavity opposite to the opening structure. The cover body of the present invention completely isolates the exposed metal part at the installation position of the transfer row from the arc extinguishing chamber, thereby preventing the exposed metal part of the transfer row from being damaged by voltage breakdown, and reducing maintenance costs. At the same time, gas backsplash is reduced, so that the arc in the arc extinguishing chamber is quickly transferred from the inside to the outside of the terminal cover, reducing the burning time of the arc, and further improving the breaking capacity of the molded case circuit breaker. The present invention also discloses a circuit breaker structure.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and in particular to a terminal cover of a molded case circuit breaker and a circuit breaker structure. Background Art

[0002] In the field of new energy, especially photovoltaic power generation, new energy molded case circuit breakers are directly connected to the transfer bar, the transfer bar is connected to the copper cable, the copper cable is buried in the ground and connected to the inverter, the inverter is connected to the photovoltaic panel, forming a series power transmission protection circuit. In actual work, when the moving and static contacts of the circuit breaker break the short-circuit current, an arc will be generated from the arc extinguishing chamber, which is easy to cause phase breakdown, parts burning and even accidents, causing damage to the equipment, so a terminal cover is usually installed on the outside of the circuit breaker to alleviate the above problems.

[0003] After the molded case circuit breaker is connected to the transfer bar, the transfer bar is then connected to other conductive conductors. The transfer bar is made of conductive material and is wrapped with an insulating skin in the middle. However, the connection position with the molded case circuit breaker and other conductors requires conductive overlap, so it cannot be wrapped with insulation. The terminal cover is usually located on the outer slot of the terminal and has a space to make way for the installation position of the transfer bar. The exposed metal part of the transfer bar is connected to the arc extinguishing chamber. Since there is a high voltage of AC800V on the top of the molded case for a long time (there is also voltage on the top after the molded case is opened), the exposed metal part of the transfer bar is prone to voltage breakdown. Moreover, if there is a fault in the system, after the molded case circuit breaker is protectively opened, the arc ejected from the arc extinguishing chamber will be ejected onto the transfer bar, causing the transfer bar to burn, and the transfer bar needs to be replaced frequently.

[0004] At the same time, after the arc is ejected through the arc extinguishing chamber, the ejection direction is quite random. Most of the arc is directly ejected onto the terminal cover directly above and contacts the metal parts of the terminal cover. The gap between the circular holes of the metal parts allows air carrying conductive particles to pass quickly. However, the non-circular hole position forms a gas obstruction. At this position, the gas is back-sprayed toward the arc chamber, which prolongs the time for the conductive metal particles to be discharged from the inside of the circuit breaker, prolonging the arc extinguishing time and thus reducing the breaking capacity of the circuit breaker. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a terminal cover and a circuit breaker structure of a molded case circuit breaker. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] A first aspect of an embodiment of the present invention provides a terminal cover for a molded case circuit breaker, comprising: a cover body;

[0007] The cover body has an open structure at one end, and has a first cavity, a second cavity and a third cavity which are connected in sequence;

[0008] The opening structure is arranged in the terminal outer slot outside the molded case circuit breaker and covers the air outlet of the arc extinguishing chamber;

[0009] The first cavity is connected to the opening structure;

[0010] The volume of the second cavity is smaller than the volumes of the first cavity and the third cavity, so as to reflect the airflow flowing out of the arc extinguishing chamber in a direction away from the opening structure and flow at a preset speed;

[0011] A plurality of vent holes are formed on the cavity wall of the third cavity opposite to the opening structure.

[0012] In one embodiment of the present invention, the inner diameter of the first cavity gradually decreases from the opening structure to the second cavity.

[0013] In one embodiment of the present invention, the range of the angle A between the first inner cavity wall of the first cavity body opposite to the airflow direction of the air outlet of the arc extinguishing chamber flow and the plane where the opening structure is located is: 60°≤A≤90°;

[0014] The range of the angle B between the second inner cavity wall opposite to the first inner cavity wall and the plane where the opening structure is located is: 70°≤B<90°.

[0015] In one embodiment of the present invention, a wall surface formed by a cover wall of the third cavity opposite to the opening structure gradually approaches the opening structure from a direction close to the adapter row to a direction away from the adapter row.

[0016] In one embodiment of the present invention, a cooling grid structure is provided on the second cavity.

[0017] In one embodiment of the present invention, the cooling grid structure comprises a substrate;

[0018] A plurality of spaced grid channels are sequentially opened on the substrate, and a grid sheet is formed between two adjacent grid channels;

[0019] Wherein, two ends of the grid channel are respectively connected to the first cavity and the third cavity;

[0020] The width of the grid sheet gradually decreases toward two end portions of the first cavity and the third cavity.

[0021] In one embodiment of the present invention, the opening structure comprises: a mounting opening, an inserting portion and a buckle;

[0022] The plug-in portion extends outwardly along the circumferential direction of the mounting opening, and two sides thereof are plugged into the side walls of the terminal outer groove;

[0023] The buckle is located at one end of the opening of the terminal outer groove, is fixedly connected to the plug-in portion, and is clamped with the groove bottom of the terminal outer groove.

[0024] In one embodiment of the present invention, the buckle is made of a thermoplastic elastic material;

[0025] One end of the buckle is fixedly connected to the plug-in portion, and the other end abuts against a clamping groove at the bottom of the outer groove of the terminal.

[0026] A second aspect of an embodiment of the present invention provides a circuit breaker structure, comprising a molded case circuit breaker and a plurality of terminal covers according to any one of claims 1 to 8;

[0027] A terminal cover is arranged in a terminal outer groove outside the molded case circuit breaker.

[0028] Beneficial effects of the present invention:

[0029] The present invention installs a cover body with an opening structure at one end in the terminal outer groove, the opening structure covers the air outlet of the arc extinguishing chamber, the cover body completely isolates the installation position of the adapter row from the cover body, and the cover body completely isolates the metal part of the adapter row exposed to the outside from the arc extinguishing chamber, which can prevent the metal part of the adapter row exposed to the outside from voltage breakdown and damage, and prevent the arc ejected from the arc extinguishing chamber from being ejected from the arc extinguishing chamber to the metal part of the adapter row exposed to the outside and cause burning, the adapter row is not easy to be damaged, the service life of the adapter row is extended, and the maintenance cost is reduced.

[0030] At the same time, the first cavity, the second cavity and the third cavity can make the gas flowing out of the arc extinguishing chamber reflect in the direction away from the opening structure when it contacts the side wall of the first cavity, and then reflect again through the second cavity and the third cavity in turn, and finally be transported to the vent for discharge, thereby reducing the gas back-spray. Moreover, the volume of the second cavity is smaller than that of the first cavity and the second cavity, and a canyon effect is formed at the position of the second cavity. When the airflow passes through the second cavity, it has an acceleration effect, so that the airflow with metal particles can be discharged quickly through the third cavity. Due to the increase in airflow speed, the arc in the arc extinguishing chamber is quickly transferred from the inside to the outside of the terminal cover, thereby reducing the burning time of the arc and further improving the breaking capacity of the molded case circuit breaker.

[0031] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0032] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0034] Figure 1 A schematic structural diagram of a terminal cover of a molded case circuit breaker provided in an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of installing a terminal cover of a molded case circuit breaker provided by an embodiment of the present invention;

[0036] Figure 3 A three-dimensional diagram of a terminal cover of a molded case circuit breaker provided by an embodiment of the present invention;

[0037] Figure 4 A schematic diagram of installing another terminal cover of a molded case circuit breaker provided by an embodiment of the present invention;

[0038] Figure 5 A schematic diagram of the structure of a cooling grid structure provided by an embodiment of the present invention;

[0039] Figure 6 Another structural intention of a terminal cover of a molded case circuit breaker provided by an embodiment of the present invention;

[0040] Figure 7 A schematic structural diagram of a molded case circuit breaker and a terminal cover provided in an embodiment of the present invention;

[0041] Figure 8 for Figure 7 An enlarged schematic diagram of part C of FIG.

[0042] Fig. 9 A schematic diagram of fluid flow velocity simulation in a terminal cover of a molded case circuit breaker provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0044] like Figure 1 , Figure 2 and Figure 3 As shown, a first aspect of an embodiment of the present invention provides a terminal cover for a molded case circuit breaker, comprising: a cover body 10.

[0045] One end of the cover 10 has an opening structure 11, and the cover 10 has a first cavity 21, a second cavity 22 and a third cavity 23 that are connected in sequence. The opening structure 11 is arranged in the terminal outer groove 71 outside the molded case circuit breaker 70, and the opening structure 11 covers the gas outlet of the arc extinguishing chamber 30.

[0046] The first cavity 21 is connected to the opening structure 11; the volume of the second cavity 22 is smaller than the volumes of the first cavity 21 and the third cavity 23, so as to reflect the airflow flowing out of the arc extinguishing chamber 30 in a direction away from the opening structure 11 and flow at a preset speed. A plurality of vent holes 234 are provided on the cavity wall of the third cavity 23 opposite to the opening structure 11.

[0047] In this embodiment, the opening structure 11 can cover the air outlet of the arc extinguishing chamber 30, and the opening structure 11 is arranged in the terminal outer groove 71 outside the molded case circuit breaker 70. Therefore, the cover body 10 completely isolates the exposed metal part of the adapter bar 80 at the installation position from the cover body 10 and the arc extinguishing chamber 30, which can prevent the exposed metal part of the adapter bar 80 from voltage breakdown and damage, and prevent the arc ejected from the arc extinguishing chamber 30 from being ejected from the arc extinguishing chamber 30 to the exposed metal part of the adapter bar 80 to cause burning, so that the adapter bar 80 is not easily damaged, the service life of the adapter bar 80 is extended, and the maintenance cost is reduced.

[0048] At the same time, the first cavity 21, the second cavity 22 and the third cavity 23 can make the gas flowing out of the arc extinguishing chamber 30 reflect in the direction away from the opening structure 11 when it contacts the side wall of the first cavity 21, and then reflect again through the second cavity 22 and the third cavity 23 in turn, and finally be transported to the vent 234 for discharge, thereby reducing the gas back-spray. Moreover, the volume of the second cavity 22 is smaller than that of the first cavity 21 and the second cavity 22, and a canyon effect is formed at the position of the second cavity 22. When the airflow passes through the second cavity 22, the pressure increases, the flow rate becomes faster, and an acceleration effect is produced, so that the airflow with metal particles can flow quickly through the second cavity 22 to the third cavity 23 at a preset speed and be discharged. Due to the increase in the airflow speed, the arc in the blank of the arc extinguishing chamber 30 is quickly transferred from the inside to the outside of the terminal cover, thereby reducing the burning time of the arc and further improving the breaking capacity of the molded case circuit breaker 70.

[0049] Here, the preset speed is greater than the flow rate of the gas when the volumes of the first cavity 21 , the second cavity 22 , and the third cavity 23 are equal.

[0050] like Fig. 9 As shown, it can be known that the flow rate of the gas in the second cavity 22 and the third cavity 23 is significantly faster than the flow rate of the gas near the lower end of the first cavity 21 .

[0051] Furthermore, the inner diameter of the first cavity 21 gradually decreases from the opening structure 11 to the second cavity 22. In this embodiment, the sudden force change point of the cover body 10 is avoided, the strength of the cover body 10 is ensured, and the processing and manufacturing are facilitated.

[0052] Furthermore, if Figure 1As shown, the range of the angle A between the first inner cavity wall 211 and the plane where the opening structure 11 is located, which is opposite to the airflow direction of the first cavity 21 and the air outlet of the arc extinguishing chamber 30, is: 60°≤A≤90°.

[0053] The range of the angle B between the second inner cavity wall 212 opposite to the first inner cavity wall 211 and the plane where the opening structure 11 is located is: 70°≤B<90°.

[0054] In this embodiment, within the angle range of the two inner cavity walls, the oblique upward airflow flowing out of the outlet of the arc extinguishing chamber 30 can quickly enter the third cavity 23 after being refracted twice at most, and the strength of the cover body 10 can be guaranteed while ensuring a fast airflow velocity. It should be noted that if the angle exceeds the above range, the width of the formed second cavity 22 is too small, resulting in excessive local pressure in the cavity, causing the cover body 10 to rupture.

[0055] Preferably, in a feasible implementation, A=87°, 70°≤B<90°.

[0056] Preferably, in a feasible implementation, A=69°, B=80°.

[0057] In one embodiment, the third cavity 23 can be configured in various shapes. For example, the inner diameter of the third cavity 23 gradually decreases from the second cavity 22 to a direction away from the second cavity 22, so that the airflow discharge is smoother and the processing is convenient.

[0058] For example, Figure 2 As shown, the third cavity 23 includes a first sub-cavity 231 and a second sub-cavity 232 which are connected in sequence. The first sub-cavity 231 and the second cavity 22 are adjacent to each other, and the inner diameter of the first sub-cavity 231 gradually decreases from the second cavity 22 to the direction away from the second cavity 22. The inner diameter of the third sub-cavity remains unchanged and is equal to the maximum inner diameter of the second sub-cavity 232. In this embodiment, the provision of the second sub-cavity 232 expands the space when the airflow flows out from the second cavity 22 to the third cavity 23, and further enables a larger volume of airflow to be discharged more quickly.

[0059] Furthermore, if Figure 2 and Figure 3 As shown, the cover wall of the third cavity 23 opposite to the opening structure 11 has a slope structure 233 that gradually approaches the opening structure 11 from a direction close to the adapter row 80 to a direction away from the adapter row 80 .

[0060] In the present embodiment, the cover wall of the third cavity 23 opposite to the opening structure 11 forms an inclined structure 233, and the outer surface of the inclined structure 233 is facing away from the installation position of the adapter row 80, that is, facing away from the adapter row 80, so that the airflow discharged from the vent 234 is sprayed in the oblique upward direction of the switch, that is, in the direction away from the adapter row 80, which can avoid contact with the adapter row 80 and the conductive components connected to the adapter row 80.

[0061] Furthermore, if Figure 4 As shown, a cooling grid structure 40 is provided on the second cavity 22. The cooling grid structure 40 can accelerate the cooling of the arc, speed up the diffusion and deionization, increase the arc resistance, and thus increase the voltage drop of the arc itself so that the applied voltage is insufficient to maintain the arc.

[0062] Preferably, if Figure 5 As shown, the cooling grid structure 40 includes a substrate 41, on which a plurality of spaced grid channels 42 are sequentially opened, and a grid sheet 43 is formed between two adjacent grid channels 42. The two ends of the grid channel 42 are respectively connected to the first cavity 21 and the third cavity 23. The width of the portion of the grid sheet 43 facing the two ends of the first cavity 21 and the third cavity 23 gradually decreases from the portion close to the two ends to the two ends. The width of the grid sheet 43 is narrow at the two ends and wide in the middle, so that the inlet 44 of the first cavity 21 to the grid channel 43 and the outlet 45 of the grid channel 43 to the third cavity 23 form a wider inlet and outlet channel, so as to accelerate the speed of gas entering and exiting the cooling grid structure 40.

[0063] In one embodiment, Figure 3 , Figure 6 , Figure 7 and Figure 8 As shown, the opening structure 11 includes: an installation opening 111, a plug-in portion 112 and a buckle 113. The installation opening 111 is connected to the first cavity 21, the plug-in portion 112 extends outward along the circumferential direction of the installation opening 111, and both sides of the plug-in portion 112 are plugged into the side walls of the terminal outer groove 71. The buckle 113 is located at one end of the opening of the terminal outer groove 71, the buckle 113 is fixedly connected to the plug-in portion 112, and the buckle 113 is snap-fitted to the bottom of the terminal outer groove 71.

[0064] In this embodiment, the cover body 10 is inserted into the terminal outer groove 71 through the plug-in portion 112 and is positioned by the buckle 113, which improves the convenience of disassembly and assembly and is very convenient to use.

[0065] Furthermore, the material of the buckle 113 is a thermoplastic elastic material, such as a TPE material. One end of the buckle 113 is fixedly connected to the plug-in portion 112, and the other end of the buckle 113 abuts against the slot 60 at the bottom of the terminal outer slot 71. In this embodiment, the other end of the buckle 113 extends toward the side of the installation opening 111. The buckle 113 abuts against the slot 60 to position and limit the cover body 10. When disassembling, the buckle 113 can be pried toward the outside of the slot 60 using a tool, which is convenient for disassembly and assembly.

[0066] Among them, the outer end of the terminal outer groove 71 is an opening, and slots 50 that penetrate the opening are respectively opened at positions near the bottom of the groove on the opposite side walls of the terminal outer groove 71. The two side parts of the plug-in part 112 are respectively inserted into the two slots 50 from the opening, and the buckle 113 forms a conflict with the slot 60.

[0067] like Figure 7 and Figure 8 As shown, the second aspect of the embodiment of the present invention provides a circuit breaker structure, including a molded case circuit breaker 70 and a plurality of terminal covers provided by the first aspect of the embodiment of the present invention. A terminal cover is arranged in a terminal outer groove 71 outside the molded case circuit breaker 70.

[0068] In this embodiment, the molded case circuit breaker 70 has a plurality of terminal structures, and a terminal outer groove 71 is provided at a corresponding position of each terminal structure, and a terminal cover is provided on a terminal outer groove 71, and the terminal cover can cover the gas outlet of the arc extinguishing chamber 30. The circuit breaker structure of this embodiment can prevent the metal part of the transfer bar 80 exposed to the outside from voltage breakdown and damage, and prevent the arc ejected from the arc extinguishing chamber 30 from being ejected from the arc extinguishing chamber 30 to the metal part of the transfer bar 80 exposed to the outside from burning, and the transfer bar 80 is not easy to be damaged, the service life of the transfer bar 80 is extended, and the maintenance cost is reduced. The terminal cover can also reduce the back-spray of the gas flowing out of the arc extinguishing chamber 30, and accelerate the discharge of these gases, thereby reducing the burning time of the arc and further improving the breaking capacity of the product.

[0069] Furthermore, the outer end of the terminal outer groove 71 is an opening, and slots 50 passing through the opening are respectively provided at positions near the bottom of the groove on the opposite side walls of the terminal outer groove 71, and the two side portions of the plug-in portion 112 of the terminal cover are respectively inserted into the two slots 50 from the opening, and the buckle 113 of the terminal cover forms a conflict with the slot 60.

[0070] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A terminal cover of a molded case circuit breaker, characterized in that: include: Cover body (10); The cover body (10) has an opening structure (11) at one end, and has a first cavity (21), a second cavity (22), and a third cavity (23) which are connected in sequence; The opening structure (11) is arranged in the terminal outer groove (71) outside the molded case circuit breaker, covering the gas outlet of the arc extinguishing chamber (30); The first cavity (21) is connected to the opening structure (11); The volume of the second cavity (22) is smaller than the volumes of the first cavity (21) and the third cavity (23), so as to reflect the airflow flowing out through the arc extinguishing chamber (30) in a direction away from the opening structure (11) and to flow at a preset speed; A plurality of ventilation holes (234) are provided on the cavity wall of the third cavity (23) opposite to the opening structure (11); The inner diameter of the first cavity (21) gradually decreases in a direction from the opening structure (11) to the second cavity (22); The range of the angle A between the first inner cavity wall (211) opposite to the airflow direction of the air outlet of the first cavity (21) and the arc extinguishing chamber (30) and the plane where the opening structure (11) is located is: 60°≤A≤90°; The range of the angle B between the second inner cavity wall (212) opposite to the first inner cavity wall (211) and the plane where the opening structure (11) is located is: 70°≤B<90°.

2. A terminal cover for a molded case circuit breaker according to claim 1, characterized in that: The wall surface formed by the cover wall of the third cavity (23) and the opening structure (11) gradually approaches the opening structure (11) from a direction close to the adapter row (80) to a direction away from the adapter row (80).

3. The terminal cover of a molded case circuit breaker according to claim 1, characterized in that: A cooling grid structure (40) is provided on the second cavity (22).

4. A terminal cover for a molded case circuit breaker according to claim 3, characterized in that: The cooling grid structure comprises a base (41); A plurality of spaced grid channels (42) are sequentially provided on the base body (41), and a grid sheet (43) is formed between two adjacent grid channels (42); Wherein, two ends of the grid channel (42) are respectively connected to the first cavity (21) and the third cavity (23); The width of the grid sheet (43) gradually decreases towards the two end portions of the first cavity (21) and the third cavity (23).

5. The terminal cover of a molded case circuit breaker according to claim 1, characterized in that: The opening structure (11) comprises: a mounting opening (111), an inserting portion (112) and a buckle (113); The plug-in portion (112) extends outwardly along the circumferential direction of the mounting opening (111), and two sides thereof are plugged into side walls of the terminal outer groove (71); The buckle (113) is located at one end of the opening of the terminal outer groove (71), is fixedly connected to the plug-in portion (112), and is snap-fitted to the bottom of the groove of the terminal outer groove (71).

6. A terminal cover for a molded case circuit breaker according to claim 5, characterized in that: The material of the buckle (113) is a thermoplastic elastic material; One end of the buckle (113) is fixedly connected to the plug-in portion (112), and the other end abuts against a clamping groove (60) at the bottom of the terminal outer groove (71).

7. A circuit breaker structure, characterized in that: Comprising a molded case circuit breaker (70) and a plurality of terminal covers according to any one of claims 1 to 6; A terminal cover is arranged in a terminal outer groove (71) outside the molded case circuit breaker (70).

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