Conductive loop of molded case circuit breaker
By adopting a conductive circuit structure with contact protective cover and soft connection of copper foil in the plastic case circuit breaker, the problems of ablation and structural stagnation during the breaking of the fault current are solved, and faster fault current cut-off and improvement are achieved High product reliability.
Patent Information
- Application Number
- CN202310819881.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-05
- Publication Date
- 2025-01-07
AI Technical Summary
The existing plastic case circuit breakers are prone to ablation and structural stagnation during the breakdown of the fault current, resulting in product failure and safety hazards. The flexibility of the conductive circuit of the dynamic contact under high rated current is insufficient, which affects the normal operation of the fault current. and cut-off performance.
A conductive circuit structure with contact sheet protective cover and copper foil soft connection is designed, using flexible conductors with upper and lower strands and conductive segment protective tongue to improve the insulation protection and rapid action ability of the conductive circuit, and optimize heat dissipation through the hollow structure. Effects and enhances electromagnetic force to ensure rapid cutoff of fault current.
It effectively reduces the operating temperature rise, improves the operating speed of the moving contact plate and product reliability, ensures rapid cut-off of the fault current, and improves the safety and reliability of the circuit breaker.
Smart Images
Figure CN119275072A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a circuit breaker, in particular to a conductive loop structure of the circuit breaker. Background Art
[0002] The molded case circuit breaker consists of a moving contact, a static contact, an arc extinguishing chamber, a housing, an operating mechanism, a rotating shaft, a tripping protection unit, etc.
[0003] The operating mechanism drives the shaft with the moving contact installed to rotate inside the shell, so that the moving contact and the static contact fit together or separate, thereby realizing the conduction and disconnection of the protected line. When a fault occurs in the line, the tripping protection unit senses and acts, driving the operating mechanism to trip, so that the moving contact and the static contact are quickly separated, so as to achieve the effect of cutting off the fault current. In the process of rapid separation of the moving contact and the static contact, an arc will be generated between the moving contact and the static contact, and enter the arc extinguishing chamber to extinguish. The generation and extinguishing process of the arc is often accompanied by the process of high-temperature arc ablation of the moving contact, the static contact and the arc extinguishing chamber, etc., generating a large amount of metal and non-metal particles. On the one hand, these are easy to burn the internal structure of the molded case circuit breaker, causing product failure; on the other hand, they are easy to cause structural jamming, making the product unable to work normally.
[0004] In the prior art, the conductive circuit of the moving contact includes a moving contact, a flexible connection and a conductor, which are connected in sequence to form a conductive path, wherein the moving contact includes a moving contact point and a moving contact piece, which are welded together. The flexible connection is composed of a copper wire soft braided wire, one end of which is welded and fixed to the moving contact piece to form an electrical connection, and the other end is welded to the conductor to form an electrical connection. In a circuit breaker with a larger rated current, each phase moving contact will use a plurality of moving contacts in parallel to increase the cross-sectional area of the contact point and the current path to reduce the adverse effects of the Holm force and the skin effect. The flexible connection composed of a copper wire soft braided wire, a whole strand of copper braided wire, is a loose structure. In rated current products, the thickness of the copper braided wire is often increased in order to increase its conductive cross-sectional area, which can easily lead to the inflexibility of the moving contact piece, affecting the normal action and action speed during fault current, affecting the performance of the product in breaking fault current, and causing safety hazards in use. Summary of the invention
[0005] The purpose of the present invention is to provide a conductive circuit structure of a moving contact of a molded case circuit breaker with a contact protection cover and a copper foil flexible connection, so as to solve the problems of insulation protection and rapid action in the process of breaking fault current of the conductive system of the molded case circuit breaker.
[0006] In order to achieve the above-mentioned purpose, the present invention designs a conductive circuit of a molded case circuit breaker, including a contact piece, a contact point, a rotating shaft, a housing, a protective cover, a flexible connection, a conductive member, a fixing member, and an elastic member. The contact point is tightly fixed on one end of the contact piece, the other end of the contact piece is fixedly connected with one end of the flexible connection, the other end of the flexible connection is fixedly connected with the conductive member, the contact point, the contact piece, the flexible connection, and the conductive member are connected and connected in sequence, and together constitute the conductive circuit of the molded case circuit breaker. The conductive circuit of the molded case circuit breaker is rotatably mounted on the rotating shaft through the contact piece. The rotating shaft is rotatably mounted in the rotor cavity of the housing so that the contact piece can rotate in the housing. The contact piece is installed with a protective cover. It is characterized in that the flexible connection is provided with an upper flexible section and a lower flexible section. The upper flexible section is arranged close to the inner shell of the housing, and the lower flexible section is arranged close to the bottom shell of the housing; there is a hollow space between the upper flexible section and the lower flexible section. The protective cover is provided with a conductive segment protective tongue, which covers a limit block on the rotating shaft. The conductive segment protective tongue is coupled with the limit block to isolate the contact piece from the arc extinguishing cavity in the housing.
[0007] Furthermore, the two ends of the flexible connection are provided with a contact fixed end and a conductive member fixed end of a rigid conductor. The contact fixed end is fixedly connected to the contact, and the conductive member fixed end is fixedly connected to the conductive member. The contact fixed end and the conductive member fixed end are connected to each other through the upper flexible section and the lower flexible section of the two flexible conductors.
[0008] Furthermore, the contact piece includes a contact section, a conductive section, and a movable end. The contact section is provided with a contact slot for fixing the contact point, and the contact section is provided with an assembly hole for installing a protective cover. A rotating hole is provided in the middle of the movable end. A fixed slot coupled with the fixed end of the contact piece is provided on the side of the movable end close to the soft connection. An arc-shaped upper supporting surface is provided on the upper side of the fixed slot, and an arc-shaped lower supporting surface is provided on the lower side of the fixed slot. An elastic member action slot for installing an elastic member is provided on the side of the movable end close to the rotating shaft. The movable end is naturally transitioned through the conductive section and connected to the contact section for conduction.
[0009] Furthermore, the protective cover is provided with a contact segment protective sheet coupled with the contact segment on the contact piece. Side protective sheets matching the contact segment are provided on both sides of the contact segment protective sheet; the side protective sheets are provided with mounting holes corresponding to the assembly holes on the contact segment. The side of the contact segment protective sheet close to the conductive segment of the contact piece naturally transitions and extends to form a conductive segment protective tongue. The side of the contact segment protective sheet close to the contact slot of the contact piece is provided with a notch contact hole for fixing the contact.
[0010] Furthermore, the outer shell is enclosed by an inner shell located at the upper part, a bottom shell located at the lower part, and a side wall to form an internal hollow rotor cavity and an arc extinguishing cavity. The rotor cavity is located in the middle of the outer shell; the rotor cavity is coupled with the rotating shaft. The bottom shell is provided with an arc-shaped bearing surface near and toward the fixed end of the flexible-connected conductive member. The bottom shell and the bearing surface are coupled with the lower flexible section.
[0011] Furthermore, a connecting section fixedly connected to the flexible connection is provided on one side of the conductive member close to the flexible connection. A circular arc-shaped supporting surface is provided on the connecting section close to and facing the flexible connection. The inner shell and the supporting surface are coupled with the flexible section.
[0012] The technical effect of the present invention is that the hollow upper and lower stranded copper foil flexible connection moving contact is designed; the internal space of the shell is more reasonably utilized to increase the current-carrying area of the flexible connection, improve the heat dissipation effect of this link, thereby reducing the operating temperature rise of the molded case circuit breaker; at the same time, the upper and lower stranded copper foil flexible connection structure can effectively provide electromagnetic force in the process of breaking the fault current, increase the action speed of the moving contact piece, and ensure the rapid interruption of the fault current of the molded case circuit breaker. In addition, the contact piece adopts a protective cover with a conductive segment protective tongue. Through the staggered protection design of the conductive segment protective tongue and the insulating shaft, it more effectively helps the contact piece to isolate the metal and non-metal particles from the arc extinguishing chamber in the process of breaking the fault current, and is not affected by them, thereby improving the reliability of the product. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 A structural schematic diagram of a conductive circuit closing state of a molded case circuit breaker according to the present invention;
[0014] Figure 2 The present invention relates to a structure of a molded case circuit breaker in a conductive circuit opening state;
[0015] Figure 3 An exploded structural diagram of a protective cover of a conductive circuit of a molded case circuit breaker according to the present invention;
[0016] Figure 4 An enlarged view of a partial structure of a protective cover of a conductive circuit of a molded case circuit breaker according to the present invention;
[0017] Figure 5 A schematic diagram of the structure of the copper braided wire of the conductive loop of the molded case circuit breaker in the prior art;
[0018] Figure 6 A structural schematic diagram of a copper foil flexible connection of a conductive circuit of a molded case circuit breaker according to the present invention; DETAILED DESCRIPTION
[0019] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.
[0020] Marking Description:
[0021] Contact piece 1, 1a, contact section 101, conductive section 102, movable end 103, contact slot 104, assembly hole 105, fixing slot 106, upper support surface 107, lower support surface 108, rotation hole 109, elastic member action slot 110,
[0022] Contact 2,
[0023] Rotating shaft 3, limit block 301,
[0024] Shell 4, rotor cavity 401, bearing surface 402, inner shell 403, bottom shell 404, arc extinguishing cavity 405,
[0025] Protective cover 5, side protective sheet 501, spacer 502, contact hole 503, contact segment protective sheet 504, conductive segment protective tongue 505, mounting hole 506, mounting groove 507
[0026] Flexible connection 6, contact fixed ends 601, 601a, conductive member fixed ends 602, 602a, upper flexible section 603, lower flexible section 604, flexible sections 603a, 603b,
[0027] Conductive member 7, connecting section 701, conducting section 702, transition section 703, terminal 704, supporting surface 705,
[0028] Fixed part 8, elastic part 9.
[0029] like Figure 1 and Figure 2As shown, a conductive circuit of a molded case circuit breaker provided by the present invention comprises a contact piece 1, a contact 2, a rotating shaft 3, a housing 4, a protective cover 5, a flexible connection 6, a conductive member 7, a fixing member 8, and an elastic member 9. The contact 2 is tightly fixed on one end of the contact piece 1, the other end of the contact piece 1 is fixedly connected with one end of the flexible connection 6, the other end of the flexible connection 6 is fixedly connected with the conductive member 7, the contact 2, the contact piece 1, the flexible connection 6, and the conductive member 7 are connected and connected in sequence, and together constitute a conductive circuit of the molded case circuit breaker. The conductive circuit of the molded case circuit breaker is rotatably mounted on the rotating shaft 3 via the contact piece 1. The rotating shaft 3 is rotatably mounted in the rotor cavity 401 of the housing 4, so that the contact piece 1 can rotate in the housing 4. Figure 1 As shown, when the contact piece 1 moves along the rotating shaft 3 to be close to the bottom shell 404, the molded case circuit breaker is in a closed state; Figure 2 As shown, when the contact piece 1 moves away from the bottom shell 404 along with the rotating shaft 3, the molded case circuit breaker is in the open state.
[0030] Figure 1 The housing 4 shown is formed by an inner housing 403 located at the upper part, a bottom housing 404 located at the lower part, and a side wall envelope to form an internal hollow space. The dotted inner part located in the middle of the housing 4 is a rotor cavity 401. The rotor cavity 401 is coupled with the rotating shaft 3, and the rotating shaft 3 can rotate in the rotor cavity 401. The movable cavity in which the contact piece 1 rotates with the rotating shaft 3 is an arc extinguishing cavity 405. When the circuit breaker breaks the fault current, a large amount of metal and non-metal particles will be generated in the arc extinguishing cavity 405. The bottom housing 404 is provided with an arc-shaped bearing surface 402 at a position close to and facing the fixed end 602 of the conductive part of the flexible connection 6. The bottom housing 404 and the bearing surface 402 are coupled with the lower flexible section 604. When the contact piece 1 moves to pull the flexible connection 6, or when the conductive circuit is energized and the flexible connection 6 is subjected to electromagnetic force, the lower flexible section 604 of the flexible connection 6 close to the bearing surface 402 will be tightly attached to the bearing surface 402 to obtain support and force transmission.
[0031] Figure 3The contact piece 1 of the conductive circuit of a molded case circuit breaker provided by the present invention is a sheet structure made of conductive material. It is particularly pointed out that the number of contacts 1 per phase of molded case circuit breakers of different current specifications is different. The number of contacts 1 per phase of a molded case circuit breaker of small current specification is one; in order to reduce the adverse effects of Holm force and skin effect, a molded case circuit breaker of large current specification will use multiple contacts 1 in parallel per phase to increase the cross-sectional area of the contact point and the current path. The contact piece 1 is composed of three parts: a contact section 101, a conductive section 102, and a movable end 103, and is bent. The contact section 101 is located at one end of the contact piece 1, and a contact slot 104 is provided on the contact section 101. The shape of the contact slot 104 matches the contact 2, and the contact 2 is fixed on the contact slot 104 to achieve the connection and conduction between the contact 2 and the contact piece 1. The molded case circuit breaker drives the contact piece 1 to fit and separate with the static contact through the operating mechanism to achieve the on and off of the protection circuit. The contact section 101 is provided with an assembly hole 105 for installing the protective cover 5. A movable end 103 is provided at the other end of the contact 1. A rotation hole 109 is provided in the middle of the movable end 103. The contact 1 is rotatably mounted on the rotating shaft 3 through the rotation hole 109. A fixing groove 106 is provided on the side of the movable end 103 close to the flexible connection 6. The fixing groove 106 is coupled with the contact fixed end 601 of the flexible connection 6. The contact fixed end 601 of the flexible connection 6 is fixed to the fixing groove 106 to achieve connection and conduction between the flexible connection 6 and the contact 1. An arc-shaped upper support surface 107 is provided on the upper side of the fixing groove 106, and an arc-shaped lower support surface 108 is provided on the lower side of the fixing groove 106. When the contact piece 1 moves to pull the flexible connection 6, or the conductive circuit is energized and the flexible connection 6 is subjected to electromagnetic force, the upper flexible section 603 of the flexible connection 6 close to the upper support surface 107 will be closely attached to the upper support surface 107, and obtain support and force transmission; the lower flexible section 604 of the flexible connection 6 close to the lower support surface 108 will be closely attached to the lower support surface 108, and obtain support and force transmission. The side of the movable end 103 close to the rotating shaft 3 is provided with an elastic member action groove 110, and the elastic member action groove 110 is used for the installation of the elastic member 9. The movable end 103 is naturally transitioned through the conductive section 102 and connected to the contact section 101.
[0032] Figure 3The protective cover 5 made of insulating material of the conductive circuit of a molded case circuit breaker provided by the present invention is provided with a contact segment protective sheet 504 coupled with the contact segment 101 on the contact piece 1. Side protective sheets 501 matching the shape of the contact segment 101 are provided on both sides of the contact segment protective sheet 504. The contact segment protective sheet 504 and the side protective sheets 501 are enclosed to form a spatial installation groove 507, which is used to install the contact piece 1, form insulation protection for the contact segment 101, isolate the contact segment 101 from the arc extinguishing cavity 405 in the housing 4, and prevent the high-temperature metal particles and non-metallic particles in the arc extinguishing cavity 405 from damaging the contact piece 1 when the molded case circuit breaker breaks the current. It is worth pointing out that for the structure of multiple contacts 1 in parallel per phase, a plurality of spacers 502 are provided in the middle of the side protective sheets 501 on both sides, and the space enclosed by the side protective sheets 501 on both sides and the contact segment protective sheet 504 is divided into a plurality of installation grooves 507. The side protection sheet 501 and the spacer 502 are provided with mounting holes 506. The mounting holes 506 correspond to the assembly holes 105 on the contact segment 101. The contact segment protection sheet 504 is close to the side of the conductive segment 102 of the contact 1, and naturally extends to form a conductive segment protection tongue 505. The conductive segment protection tongue 505 is coupled with the rotating shaft 3 to cover the passage from the conductive segment 102 to the arc extinguishing cavity 405, so that the contact 1 is isolated from the arc extinguishing cavity 405 in the housing 4, and the high-temperature metal particles and non-metallic particles in the arc extinguishing cavity 405 are prevented from damaging the contact 1 when the molded case circuit breaker breaks the current. The contact segment protection sheet 504 is close to the side of the contact slot 104 of the contact 1, and a notch contact hole 503 is reserved for the fixed installation of the contact 2. When the contact 2 is fixed to the contact 1, it just passes through the contact hole 503. The insulation protection of the protective cover 5 to the contact 1 does not affect the connection and disconnection of the conductive circuit of the molded case circuit breaker.
[0033] Figure 6 The conductive part 7 of the conductive circuit of a molded case circuit breaker provided by the present invention is provided with a connecting section 701 fixedly connected and conductive with the flexible connection 6 on one side thereof. The flexible connection 6 is connected and conductive with the conductive part 7 by being fixedly connected with the connecting section 701. The connecting section 701 is provided with an arc-shaped supporting surface 705 near and toward the flexible connection 6. The inner shell 403 and the supporting surface 705 are coupled with the upper flexible section 603. When the contact piece 1 moves to pull the flexible connection 6, or when the conductive circuit is energized and the flexible connection 6 is subjected to electromagnetic force, the upper flexible section 603 of the flexible connection 6 near the supporting surface 705 will be tightly attached to the supporting surface 705 to obtain support and force transmission.
[0034] Figure 1 and Figure 2The flexible connection 6 of the conductive circuit of a molded case circuit breaker provided by the present invention is provided with a contact fixed end 601 and a conductive member fixed end 602 of a rigid conductor at both ends. The contact fixed end 601 is fixedly connected to the contact 1. The conductive member fixed end 602 is fixedly connected to the conductive member 7. The contact fixed end 601 and the conductive member fixed end 602 are connected to each other through the upper flexible segment 603 and the lower flexible segment 604 of two flexible conductors. The upper flexible segment 603 is arranged close to the inner shell 403 of the outer shell 4, and the lower flexible segment 604 is arranged close to the bottom shell 404 of the outer shell 4. The space between the upper flexible segment 603 and the lower flexible segment 604 is hollow, which is conducive to the circulation of heat dissipating air in the middle to take away the relevant heat. When the fault current passes through the upper flexible section 603 and the lower flexible section 604, since the currents passing through the upper flexible section 603 and the lower flexible section 604 are in the same direction, an electromagnetic force of attraction is generated between the upper flexible section 603 and the lower flexible section 604, so that the flexible connection 6 moves toward the bottom shell 404, thereby driving the contact piece 1 to have a tendency to flip upward. When the molded case circuit breaker is opened, the electromagnetic force exerted on the upper flexible section 603 and the lower flexible section 604 can effectively increase the speed of the upward flipping action of the contact piece 1, so that the molded case circuit breaker can cut off the current faster and reduce the damage to the line caused by the fault current.
[0035] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and equivalent changes made by using the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.
Claims
1. A conductive circuit of a molded case circuit breaker, comprising a contact piece (1), a contact point (2), a rotating shaft (3), a housing (4), a protective cover (5), a flexible connection (6), a conductive member (7), a fixing member (8), and an elastic member (9); The contact point (2) is tightly fixed on one end of the contact piece (1), the other end of the contact piece (1) is fixedly connected to one end of the flexible connection (6), the other end of the flexible connection (6) is fixedly connected to the conductive member (7), and the contact point (2), the contact piece (1), the flexible connection (6), and the conductive member (7) are connected and connected in sequence to form a conductive circuit of the molded case circuit breaker; The conductive circuit of the molded case circuit breaker is rotatably mounted on the rotating shaft (3) via the contact piece (1); The rotating shaft (3) is rotatably mounted in the rotor cavity (401) of the housing (4), so that the contact piece (1) can rotate in the housing (4); The contact piece (1) is provided with a protective cover (5); It is characterized in that The flexible connection (6) is provided with an upper flexible section (603) and a lower flexible section (604); the upper flexible section (603) is arranged close to the inner shell (403) of the outer shell (4), and the lower flexible section (604) is arranged close to the bottom shell (404) of the outer shell (4); the space between the upper flexible section (603) and the lower flexible section (604) is hollow; The protective cover (5) is provided with a conductive segment protective tongue (505), the conductive segment protective tongue (505) covers a limit block (301) on the rotating shaft (3), and the conductive segment protective tongue (505) is coupled with the limit block (301), so that the contact piece (1) is isolated from the arc extinguishing chamber (405) in the housing (4).
2. A conductive circuit of a molded case circuit breaker according to claim 1, characterized in that: The two ends of the flexible connection (6) are provided with a contact piece fixing end (601) and a conductive member fixing end (602) of a rigid conductive body; The contact piece fixed end (601) is fixedly connected to the contact piece (1); The conductive member fixed end (602) is fixedly connected to the conductive member (7); The contact piece fixed end (601) and the conductive element fixed end (602) are connected to each other and conducted via an upper flexible section (603) and a lower flexible section (604) of two flexible conductors.
3. A conductive circuit of a molded case circuit breaker according to claim 1, characterized in that: The contact piece (1) comprises a contact section (101), a conductive section (102), and a movable end (103); The contact section (101) is provided with a contact groove (104) for fixing the contact (2); the contact section (101) is provided with an assembly hole (105) for installing the protective cover (5); A rotating hole (109) is provided in the middle of the movable end (103); A fixing groove (106) coupled to the fixed end (601) of the contact piece is provided on one side of the movable end (103) close to the flexible connection (6); an arc-shaped upper supporting surface (107) is provided on the upper side of the fixing groove (106); and an arc-shaped lower supporting surface (108) is provided on the lower side of the fixing groove (106); An elastic member action groove (110) for installing the elastic member (9) is provided on one side of the movable end (103) close to the rotating shaft (3); The movable end (103) naturally transitions through the conductive segment (102) and is connected and conducted with the contact segment (101).
4. A conductive circuit of a molded case circuit breaker according to claim 1, characterized in that: The protective cover (5) is provided with a contact segment protective sheet (504) coupled to the contact segment (101) on the contact sheet (1); Side protection sheets (501) matching the contact section (101) are arranged on both sides of the contact section protection sheet (504); the side protection sheets (501) are provided with mounting holes (506) corresponding to the mounting holes (105) on the contact section (101); The contact segment protection sheet (504) is located on one side of the conductive segment (102) of the contact sheet (1), and naturally transitions and extends to form a conductive segment protection tongue (505); A notched contact hole (503) for fixing the contact (2) is reserved on one side of the contact segment protection sheet (504) close to the contact slot (104) of the contact sheet (1).
5. The conductive circuit of a molded case circuit breaker according to claim 1, characterized in that: The outer shell (4) is composed of an inner shell (403) located at the upper part, a bottom shell (404) located at the lower part, and a side wall to form an internal hollow rotor cavity (401) and an arc extinguishing cavity (405); The rotor cavity (401) is located in the middle of the housing (4); the rotor cavity (401) is coupled to the rotating shaft (3); The bottom shell (404) is provided with an arc-shaped bearing surface (402) at a position close to and facing the fixed end (602) of the conductive member of the flexible connection (6); The bottom shell (404) and the bearing surface (402) are coupled with the lower flexible section (604).
6. A conductive circuit of a molded case circuit breaker according to claim 1, characterized in that: A connection section (701) fixedly connected and conductive with the flexible connection (6) is provided on one side of the conductive member (7) close to the flexible connection (6); The connection section (701) is provided with an arc-shaped supporting surface (705) near and facing the flexible connection (6); The inner shell (403) and the support surface (705) are coupled to the upper flexible section (603).