A molded case circuit breaker

Abstract

The utility model relates to a moulded case circuit breaker belongs to low pressure electric appliance technical field. Including circuit breaker body, radiator and base, the base splices at the bottom of circuit breaker body, constitutes the heat dissipation channel in base, the radiator is located in heat dissipation channel and is connected with the static conductive system of circuit breaker body. Advantage: the radiator is connected with the static conductive system, directly conducts the heat of the core heat source of circuit breaker, the radiator is located in the heat dissipation channel in the base inside and located the circuit breaker body outside, and under the premise of guaranteeing safety, realizes heat dissipation through external cooling and gas flow, thereby, effectively reduces the temperature rise of moulded case circuit breaker, improves the heat dissipation effect.

Description

Technical Field

[0001] This utility model belongs to the field of low-voltage electrical technology and relates to a molded case circuit breaker, specifically a molded case circuit breaker with a heat dissipation structure. Background Technology

[0002] The core of a molded case circuit breaker is a switching device that controls and protects circuits and electrical equipment. It can connect, disconnect, and carry current under normal circuit conditions. Furthermore, when an abnormality occurs in the circuit, it can quickly disconnect the current under abnormal circuit conditions to prevent equipment damage or the escalation of accidents.

[0003] According to Joule's law, the heat generated by a current-carrying conductor is proportional to its resistance and the square of the current. Therefore, in engineering, the cross-sectional area of ​​the conductor is often increased to reduce its resistance, thereby effectively reducing heat generation. However, within a certain frame size, the increase in the conductor cross-sectional area of ​​a molded case circuit breaker is limited due to volume constraints. In this case, the influence of current on heat generation is more significant, especially when using high currents, where enormous heat generation is unavoidable and seriously affects the normal use and lifespan of the circuit breaker.

[0004] To ensure that the temperature rise of molded case circuit breakers (MCCBs) remains within safe operating limits, the current method involves installing heat sinks on the circuit breaker terminals for cooling. However, this method not only increases the installation length of the incoming and outgoing lines but also fails to achieve ideal cooling results. The reason for this lies in the fact that the core heat source of the circuit breaker is located internally: the connection and disconnection of the circuit by the moving and stationary contacts are achieved through their opening and closing. When the moving and stationary contacts are electrically connected with a certain contact pressure, the highest temperature rise occurs at that contact point. However, because the moving and stationary contacts are located inside the circuit breaker housing, heat is difficult to effectively conduct to the external environment. Furthermore, to ensure that the electric arc and high-temperature airflow follow a predetermined path, and to prevent the arc generated between the moving and stationary contacts from overflowing when they open, the circuit breaker is designed as a sealed structure, making ventilation impossible. This results in a significant amount of heat generated by the contacts being difficult to dissipate to the external environment, greatly diminishing the effectiveness of simply installing heat sinks at the terminals.

[0005] In view of the above-mentioned existing technology, it is necessary to improve the structure of the existing molded case circuit breaker. To this end, the applicant has made a useful design, and the technical solution to be introduced below is produced in this context. Utility Model Content

[0006] The purpose of this invention is to provide a molded case circuit breaker that can effectively reduce the temperature rise of the molded case circuit breaker and improve the heat dissipation effect.

[0007] The purpose of this utility model is achieved as follows: a molded case circuit breaker includes a circuit breaker body, a heat sink, and a base. The base is spliced ​​to the bottom of the circuit breaker body, and a heat dissipation channel is formed inside the base. The heat sink is located inside the heat dissipation channel and is connected to the static conductivity system of the circuit breaker body.

[0008] In a specific embodiment of this utility model, the circuit breaker body includes a base, the static conductive system is fixed in the base, a connection through hole is provided on the base corresponding to the static conductive system, and a connection boss is provided on the surface of the heat sink facing the base. After the connection boss is inserted into the connection through hole, it is attached to and fastened to the static conductive system.

[0009] In another specific embodiment of this utility model, one end of the static conductive system is bent upward and then bent and extended to the other end to form a U-shaped end. The upper arm of the U-shaped end is fixed with a static contact at the end, while the lower arm extends outward toward the base and forms a first terminal block. The connecting boss of the heat sink is fastened to the bottom surface of the lower arm.

[0010] In another specific embodiment of this utility model, the radiator includes a radiator base, and fins are formed on the surface of the radiator base facing away from the base. When the connecting boss is in contact with the static conductivity system, the radiator base is in contact with the base.

[0011] In another specific embodiment of this utility model, the circuit breaker body further includes a moving contact rotatably disposed in the base and a guide rod electrically connected to the moving contact via a flexible connection. One end of the guide rod extends away from the first terminal to form a second terminal. Several base ribs extending from the surface of the base toward the base and / or several base ribs extending from the surface of the base toward the base divide the heat dissipation channel into several small heat dissipation channels corresponding to the number of poles of the molded case circuit breaker. The heat sink and the small heat dissipation channels both extend along the arrangement direction of the first terminal and the second terminal.

[0012] In another specific embodiment of this utility model, a partition is provided at each end of the length direction of the small heat dissipation channel, and the partition is provided with several ventilation holes.

[0013] In a further specific embodiment of this utility model, the number of the connecting through holes corresponding to each pole of the molded case circuit breaker is a pair, and a static conductivity system support is formed between the pair of connecting through holes. The number of the connecting bosses of the heat sink corresponding to each pole of the molded case circuit breaker is also a pair, and a boss groove is formed between the pair of connecting bosses. When the connecting bosses are inserted into the connecting through holes, the static conductivity system support is fitted into the boss groove between the pair of connecting bosses.

[0014] In a further specific embodiment of this utility model, the static conductivity system support member has a support boss protruding on the surface facing the static conductivity system. The support boss passes through the lower arm through hole opened on the lower arm of the static conductivity system from bottom to top and abuts against the surface of the upper arm end facing away from the static contact.

[0015] In another specific embodiment of this utility model, a boss through hole is provided on the connecting boss, and the static conductivity system assembly screw passes through the boss through hole and is screwed into the lower arm thread hole on the lower arm of the static conductivity system, so that the connecting boss and the lower arm are tightly installed.

[0016] In another specific embodiment of this utility model, the radiator base is provided with a base through hole, and the base mounting screw passes through the base through hole and is screwed into the base thread hole on the base, so that the radiator base is tightly installed with the base surface facing the base.

[0017] Due to the aforementioned structure, this invention offers several advantages over existing technologies: Connecting the radiator to the static conductive system enables direct heat transfer to the core heat source of the circuit breaker. The radiator is located outside the circuit breaker body and within a heat dissipation channel in the base. While ensuring safety, heat dissipation is achieved through external cooling and gas flow, effectively reducing the temperature rise of the molded case circuit breaker and improving heat dissipation. Furthermore, the radiator's connecting boss is in close contact with the static conductive system, while the radiator base is in close contact with the base. This allows for simultaneous heat transfer to the internal conductive components and the internal space of the circuit breaker, further reducing temperature rise, improving heat dissipation, and ensuring the normal operation and lifespan of the circuit breaker. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 for Figure 1 A sectional view; Figure 3a This is a schematic diagram of the static conductivity system described in this utility model; Figure 3b for Figure 3a Another perspective illustration; Figure 4a This is a schematic diagram of the front structure of the heat sink described in this utility model; Figure 4b This is a schematic diagram of the back structure of the heat sink described in this utility model; Figure 5a This is a schematic diagram of the bottom structure of the base described in this utility model; Figure 5b This is a schematic diagram of the internal structure of the base described in this utility model; Figure 6 This is a schematic diagram of the installation of the radiator and base described in this utility model; Figure 7 This is a schematic diagram of the installation of the base and partition described in this utility model; Figure 8 This is a schematic diagram of the structure of the base described in this utility model; Figure 9 This is a schematic diagram of the structure of the partition described in this utility model; Figure 10 This is a schematic diagram of the bottom of the circuit breaker body after the mounting base is installed. Figure 11 This is a schematic diagram illustrating the principle of heat movement in this utility model.

[0019] In the diagram: 1. Circuit breaker body; 11. Base; 111. Connecting through hole; 112. Base rib; 113. Static conductivity system support; 114. Support boss; 115. Base phase spacer; 116. Base housing surface; 117. Frustum; 118. Base threaded hole; 119. Base bottom partition; 12. Static conductivity system; 121. Upper arm; 122. Static contact; 123. Lower arm; 124. First terminal; 125. Lower arm threaded hole; 126. Lower arm through hole; 13. Moving contact; 14. Flexible... 1. Connection, 15. Guide rod, 151. Second terminal block, 16. Top cover; 2. Heat sink, 21. Connecting boss, 211. Boss through hole, 22. Heat sink base, 221. Base through hole, 23. Fin, 24. Boss groove; 3. Base, 31. Base rib, 311. Rib groove, 32. Fitting groove, 33. Base through hole; 4. Heat dissipation channel, 41. Small heat dissipation channel; 5. Partition plate, 51. Vent hole; 61. Static conductivity system mounting screw, 62. Base mounting screw, 63. Base mounting screw. Detailed Implementation

[0020] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. However, the description of the embodiments is not a limitation on the technical solution. Any formal but not substantive changes made based on the concept of this utility model should be considered within the protection scope of this utility model.

[0021] In the following description, all directional (or orientational) concepts involving up, down, left, right, front, and back refer to the position of the figure being described, and are intended to facilitate public understanding. Therefore, they should not be construed as a special limitation on the technical solution provided by this utility model.

[0022] See Figure 1 and Figure 2This utility model relates to a molded case circuit breaker, including a circuit breaker body 1. The circuit breaker body 1 includes a base 11 and an upper cover 16 spliced ​​above the base 11. The splicing mentioned here refers to the upper cover 16 and the base 11 being engaged by rib grooves and then fastened with screws. Specifically, taking the three-pole molded case circuit breaker in the figure of this embodiment as an example, two base phase spacers 115 are protruding inside the base 11, and the base phase spacers 115 are recessed with fitting grooves. Two upper cover phase spacers are correspondingly protruding inside the upper cover 16, and the upper cover phase spacers are provided with ribs. During assembly, the edges of the base 11 and the upper cover 16 are engaged accordingly, and the ribs on the upper cover phase spacers are fitted into the fitting grooves of the base phase spacers. Then, the upper cover 16 and the base 11 are fastened with screws to complete the splicing. The above-mentioned splicing method of the upper cover 16 and the base 11 is a known technology and will not be illustrated in this utility model.

[0023] As is also known, the upper cover 16 and the base 11 are spliced ​​together to form a cavity, and the internal components of the circuit breaker, such as the operating mechanism, tripping mechanism, moving and stationary contacts, and arc extinguishing system, are all located in this cavity. Of course, the circuit breaker also includes wiring terminals for users to connect wires, which are fixed on the base 11 and exposed outside the cavity. There is a pair of wiring terminals corresponding to each pole of the circuit breaker.

[0024] Specifically, the circuit breaker body 1 further includes a static conductive system 12 disposed within a base 11, a moving contact 13 that rotates within the base 11 to contact or separate from the static conductive system 12, and a guide rod 15 electrically connected to the moving contact 13 via a flexible connection 14. See Figure 2 , Figure 3a and Figure 3b One end of the static conductive system 12 is bent upwards and then bent and extended to the other end to form a U-shaped end. The upper arm 121 of the U-shaped end is fixed with a static contact 122 at the end, while the lower arm 123 extends outwards toward the base 11 and forms a first terminal 124. One end of the guide rod 15 extends away from the first terminal 124 and forms a second terminal 151.

[0025] See you later Figure 2 As an innovation of this utility model, a heat sink 2 and a base 3 are provided on the outside of the circuit breaker body 1, and the base 3 is spliced ​​to the bottom of the circuit breaker body 1. A heat dissipation channel 4 is formed inside the base 3, and the heat sink 2 is located in the heat dissipation channel 4 and connected to the static conductivity system 12 of the circuit breaker body 1 to transfer heat from the static conductivity system 12. In this embodiment, the heat sink 2 is also in close contact with the base 11 of the circuit breaker body 1.

[0026] See Figure 4a and Figure 4bThe radiator 2 includes a radiator base 22. Multiple elongated fins 23 are spaced apart on the surface of the radiator base 22 facing away from the base 11. The fins 23 are perpendicular to the radiator base 22. A connecting boss 21 protrudes from the side of the radiator base 22 facing the static conductivity system 12. A connecting through hole 111 is provided on the base 11 corresponding to the static conductivity system 12. The connecting boss 21 is inserted into the connecting through hole 111 and then fastened to the bottom surface of the lower arm 123.

[0027] See Figure 3b , Figure 4b and Figure 6 Specifically, the connecting boss 21 has a boss through hole 211. The static conductivity system assembly screw 61 passes through the boss through hole 211 and is screwed into the lower arm threaded hole 125 on the lower arm 123 of the static conductivity system 12, so that the connecting boss 21 and the lower arm 123 are tightly installed.

[0028] See Figure 2 , Figure 5a and Figure 6 The base 11 includes a base bottom partition 119 for sealing and fastening screws, the base bottom partition 119 being in close contact with the base housing surface 116. See Figure 4a and Figure 6 The radiator base 22 has a base through hole 221. The base mounting screw 62 passes through the base through hole 221 and is screwed into the base threaded hole 118 on the base 11, so that the radiator base 22 is tightly attached to the base bottom partition 119 of the base 11. Figure 2 As can be seen, the surface of the base 11 that is in close contact with the heat sink 2 and faces the base 3 is the lower surface of the base bottom partition 119. In order to ensure the fastening strength between the heat sink 2 and the base 11, a frustum 117 is protruding on the base housing surface 116, so that the base mounting screw 62 can be screwed into the base threaded hole 118 opened on the frustum 117. The frustum 117 passes through the base bottom partition 119 and is fitted into the base through hole 221.

[0029] See Figure 5a and Figure 5b and combined Figure 2 , Figure 3a , Figure 3b , Figure 4aFurthermore, the number of connection through holes 111 corresponding to each pole of the molded case circuit breaker is one pair, and a static conductivity system support 113 is formed between the pair of connection through holes 111. The number of connection bosses 21 of the heat sink 2 corresponding to each pole of the molded case circuit breaker is also one pair, and a boss groove 24 is formed between the pair of connection bosses 21. When the connection bosses 21 are inserted into the connection through holes 111, the static conductivity system support 113 is fitted into the boss groove 24 between the pair of connection bosses 21. The static conductivity system support 113 has a support boss 114 protruding on the surface facing the static conductivity system 12. The support boss 114 passes through the lower arm through hole 126 opened on the lower arm 123 of the static conductivity system 12 from bottom to top and abuts against the surface of the upper arm 121 facing away from the static contact 122. The pair of connecting through holes 111 can be arranged relative to each other along the width direction of the molded case circuit breaker (the arrangement direction of two adjacent poles of the molded case circuit breaker), and the pair of connecting bosses 21 are arranged relative to each other in the width direction of the molded case circuit breaker. Of course, the pair of connecting through holes 111 can also be arranged relative to each other along the length direction of the molded case circuit breaker (the arrangement direction of the first terminal 124 and the second terminal 151), and the pair of connecting bosses 21 are arranged relative to each other in the length direction of the molded case circuit breaker.

[0030] See Figure 6 , Figure 8 and Figure 10 The base 11 has several base ribs 112 extending from its surface facing the base 3, and the base 3 has several base ribs 31 extending from its surface facing the base 11. When the base 11 and the base 3 are joined, the base ribs 112 are correspondingly fitted into the rib grooves 311 on the base ribs 31. Then, the base mounting screws 63 pass through the base through holes 33 on the base 3 and are screwed into the corresponding threaded holes on the base 11 for fastening. The base ribs 112 and / or the base ribs 31 divide the heat dissipation channel 4 into several small heat dissipation channels 41, the number of which corresponds to the number of circuit breaker poles. The radiator 2, the fins 23, and the small heat dissipation channels 41 all extend along the arrangement direction of both the first terminal 124 and the second terminal 151.

[0031] In the three-pole molded case circuit breaker of this embodiment, there are two base ribs 112 and two base ribs 31, which cooperate to form three small heat dissipation channels 41. Of course, the way the small heat dissipation channels 41 are separated is not limited to the structure given in the above embodiment. It is also possible to only provide protrusions on the surface of the base 11 facing the base 3, or only provide protrusions on the surface of the base 3 facing the base 11. Of course, when the electrical clearance between two adjacent corresponding heat sinks 2 of the molded case circuit breaker is large enough, it is also possible not to divide it into small scattered channels 41 and to retain a large overall heat dissipation channel 4 between the base 11 and the base 3.

[0032] See Figure 7 , Figure 8 as well as Figure 9 Furthermore, a partition plate 5 is provided at each end of the length direction of the small heat dissipation channel 41, and several ventilation holes 51 are provided on the partition plate 5. The base 3 is provided with fitting grooves 32 at both ends corresponding to the extension direction of the small heat dissipation channel 41 for fitting and installing the partition plate 5.

[0033] Figure 11 The illustrated vertical installation method represents the conventional installation method for circuit breakers, where the circuit breaker is installed perpendicular to the ground. When current I passes through the circuit breaker's conductive circuit, heat B is generated. This heat is transferred to the fins 23 via thermal conduction. The fins 23 increase the contact area with the air, and heat B enters the heat dissipation channel 4 through the radiator 2. The temperature difference between channel A-1 and channel A-2 creates a "chimney" effect. External air C enters channel A-2 through the vent 51 on the lower partition 5. Under the "chimney" effect, the internal heat of the circuit breaker is quickly conducted to the outside of the circuit breaker through the vent 51 on the upper partition 5. Therefore, connecting the radiator 2 to the static conductive system 12 allows for direct heat conduction to the core heat source of the circuit breaker. The radiator 2 is located outside the circuit breaker body 1 and within the heat dissipation channel 4 formed between the base 3 and the circuit breaker body 1. While ensuring safety, heat dissipation is achieved through external cooling and gas flow, thereby effectively reducing the temperature rise of the molded case circuit breaker and improving heat dissipation. Furthermore, while the connecting boss 21 of the radiator 2 is in close contact with the static conductive system 12, the radiator base 22 is in close contact with the base 11. This enables the simultaneous transfer of temperature between the conductive components that generate heat inside the circuit breaker and the internal space of the circuit breaker, thereby further reducing the temperature rise of the circuit breaker, improving the heat dissipation effect, and ensuring the normal use and lifespan of the circuit breaker.

[0034] In the above embodiment, the surface where the base 3 engages with the bottom of the circuit breaker body 1 is open, see [reference]. Figure 7 The base 3 has a U-shaped cross section in the width direction of the circuit breaker. At this time, the heat dissipation channel 4 inside the base 3 is formed by the base 3 and the base 11 of the circuit breaker body 1. Of course, this utility model is not limited to the above embodiment. The base 3 can also be a box-shaped structure. The cross section of the base 3 in the width direction of the circuit breaker is “□” shaped. The bottom of the circuit breaker body 1 is spliced ​​with the top surface of the “□” shaped structure of the base 3.

Claims

1. A molded case circuit breaker, comprising a circuit breaker body (1), characterized in that: It also includes a radiator (2) and a base (3), the base (3) being spliced ​​to the bottom of the circuit breaker body (1), and a heat dissipation channel (4) being formed inside the base (3). The radiator (2) is located inside the heat dissipation channel (4) and is connected to the static conductivity system (12) of the circuit breaker body (1).

2. A molded case circuit breaker according to claim 1, characterized in that: The circuit breaker body (1) includes a base (11), the static conductive system (12) is fixed inside the base (11), and a connecting through hole (111) is provided on the base (11) corresponding to the static conductive system (12). The heat sink (2) has a connecting boss (21) protruding on the surface facing the base (11). The connecting boss (21) is inserted into the connecting through hole (111) and then attached to and fastened to the static conductive system (12).

3. A molded case circuit breaker according to claim 2, characterized in that: One end of the static conductive system (12) is bent upward and then bent and extended to the other end to form a U-shaped end. The upper arm (121) of the U-shaped end is fixed with a static contact (122) at the end, while the lower arm (123) extends outward toward the base (11) and forms a first terminal (124). The connecting boss (21) of the heat sink (2) is fastened to the bottom surface of the lower arm (123).

4. A molded case circuit breaker according to claim 2, characterized in that: The radiator (2) includes a radiator base (22), on which fins (23) are formed on the surface of the radiator base (22) facing away from the base (11). When the connecting boss (21) is in contact with the static conductivity system (12), the radiator base (22) is in contact with the base (11).

5. A molded case circuit breaker according to claim 2, characterized in that: The circuit breaker body (1) also includes a moving contact (13) rotatably disposed in the base (11) and a guide rod (15) electrically connected to the moving contact (13) via a flexible connection (14). One end of the guide rod (15) extends away from the first terminal (124) to form a second terminal (151). Several base ribs (112) extending from the surface of the base (11) toward the base (3) and / or several base ribs (31) extending from the surface of the base (3) toward the base (11) divide the heat dissipation channel (4) into several small heat dissipation channels (41) corresponding to the number of poles of the molded case circuit breaker. The radiator (2) and the small heat dissipation channels (41) both extend along the arrangement direction of the first terminal (124) and the second terminal (151).

6. A molded case circuit breaker according to claim 5, characterized in that: A partition (5) is provided at both ends of the length direction of the small heat dissipation channel (41), and several ventilation holes (51) are provided on the partition (5).

7. A molded case circuit breaker according to claim 3, characterized in that: The number of the connecting through holes (111) corresponding to each pole of the molded case circuit breaker is one pair. A static conductivity system support (113) is formed between the pair of connecting through holes (111). The number of the connecting bosses (21) of the heat sink (2) corresponding to each pole of the molded case circuit breaker is also one pair. A boss groove (24) is formed between the pair of connecting bosses (21). When the connecting bosses (21) are inserted into the connecting through holes (111), the static conductivity system support (113) is fitted into the boss groove (24) between the pair of connecting bosses (21).

8. A molded case circuit breaker according to claim 7, characterized in that: The static conductivity system support member (113) has a support boss (114) protruding on the surface facing the static conductivity system (12). The support boss (114) passes through the lower arm through hole (126) opened on the lower arm (123) of the static conductivity system (12) from bottom to top and abuts against the surface of the upper arm (121) facing away from the static contact (122).

9. A molded case circuit breaker according to claim 7, characterized in that: The connecting boss (21) has a boss through hole (211). The static conductivity system assembly screw (61) passes through the boss through hole (211) and is screwed into the lower arm thread hole (125) on the lower arm (123) of the static conductivity system (12), so that the connecting boss (21) and the lower arm (123) are tightly installed.

10. A molded case circuit breaker according to claim 4, characterized in that: The radiator base (22) has a base through hole (221). The base mounting screw (62) passes through the base through hole (221) and is screwed into the base thread hole (118) on the base (11), so that the radiator base (22) and the surface of the base (11) facing the base (3) are tightly installed.

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