An explosion-proof circuit breaker housing structure

Abstract

The utility model discloses a kind of explosion-proof circuit breaker shell structures, including double-layer explosion-proof housing, the double-layer explosion-proof housing is by the arc-extinguishing chamber shell of inner layer and the protective housing of outer layer, clearance between arc-extinguishing chamber shell and protective housing forms inert gas filling layer, dry nitrogen is filled in inert gas filling layer, the back of arc-extinguishing chamber shell and protective housing is coaxially provided with exhaust port, pressure release valve is fixedly installed outside exhaust port;Pressure release valve includes release shell, plugging plug and buffer, release shell is fixedly connected with protective housing and covers exhaust port, release shell inside is equipped with installation inner cavity and is provided with exhaust hole, buffer one end is fixed in installation inner cavity side wall, other end connects the center of circular-truncated-cone plugging plug, buffer outside is coaxially equipped with compression spring.The utility model sets up double explosion-proof barrier to block explosion propagation path, the cooperation design of circular-truncated-cone plugging plug and conical exhaust port, in combination with the two-stage action of buffer and compression spring, realize rapid pressure relief.

Description

Technical Field

[0001] This utility model relates to the field of circuit breaker technology, specifically to an explosion-proof circuit breaker housing structure. Background Technology

[0002] In the current development of modular circuit breaker technology, safety has always been a key research direction. Existing products, in pursuit of extremely small size and low cost, typically use only a single-layer plastic shell. For example, Chinese patent CN213816005U describes a miniature circuit breaker with a hollow cylindrical shell. Two sets of shell connecting plates and terminals are respectively set on the two end faces of the shell, and the shell connecting plates and terminals are connected through the shell wall. The fuse is set inside the shell and includes core connecting plates at both ends, which are in contact with the shell connecting plates. An adjusting block is set on the end face of the shell, which is connected to the fuse and controls its rotation around the shell. The two ends of the core shell are closed, and the core shell is filled with fusible material. The core connecting plates are set in pairs at both ends of the core shell, and the core connecting plates extend into the core shell through the core shell wall. When the main circuit fault is eliminated, the adjusting block flips the fuse, thereby restoring its fusing function and achieving cyclic use.

[0003] However, its casing is still limited to the basic structure of conventional circuit breakers and does not involve any explosion-proof design elements. When encountering abnormal situations such as short-circuit arcs or internal faults, high-temperature and high-pressure gases may be generated rapidly inside the equipment, which cannot effectively suppress or release energy, and may easily cause the casing to break from weak points or even cause secondary accidents in the distribution box. Summary of the Invention

[0004] The purpose of this invention is to provide an explosion-proof circuit breaker housing structure. The housing is equipped with a double explosion-proof barrier to block the explosion propagation path. The combination of a frustum-shaped sealing plug and a conical exhaust port, along with the two-stage action of a buffer and a compression spring, enables rapid pressure relief. The inert gas filling layer between the double-layer explosion-proof housing and the release housing is seamlessly connected, so that the entire circuit breaker housing is completely covered by a nitrogen barrier. This achieves a deep integration of explosion protection, heat dissipation, and pressure relief, solving the problems in the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: An explosion-proof circuit breaker housing structure includes a double-layer explosion-proof housing, which is composed of an inner arc-extinguishing chamber housing and an outer protective shell housing. The gap between the arc-extinguishing chamber housing and the protective shell housing forms an inert gas filling layer, which is filled with dry nitrogen. An exhaust port is coaxially provided on the back of the arc-extinguishing chamber housing and the protective shell housing, and a pressure relief valve is fixedly installed on the outside of the exhaust port housing. The pressure relief valve includes a release shell, a sealing plug, and a buffer. The release shell has a double-layer structure. The release shell, the arc-extinguishing chamber shell, and the protective shell are integrally cast. The release shell and the protective shell are fixedly connected and cover the exhaust port. The release shell has an internal installation cavity, and an exhaust hole is opened at the top, bottom, and sides. One end of the buffer is fixed to the side wall of the installation cavity, and the other end is connected to the center of the frustum-shaped sealing plug. A compression spring is coaxially sleeved on the outside of the buffer. A heat dissipation ring is snapped into the exhaust port. The side wall of the heat dissipation ring fits against the inner wall of the exhaust port. The two ends of the heat dissipation ring extend to the inner cavity of the arc-extinguishing chamber shell and the installation cavity, respectively.

[0006] Preferably, the arc-extinguishing chamber shell and the protective shell are fixedly connected by a connecting rib, which is located at the inflection point or the center of the connection surface between the arc-extinguishing chamber shell and the protective shell.

[0007] Preferably, a sealing ring is coaxially fixed to the side of the sealing plug near the buffer, and the diameter of the sealing ring is greater than the maximum diameter of the exhaust port and equal to the diameter of the installation cavity.

[0008] Preferably, the inner diameter of the exhaust port gradually increases from the inside to the outside, and its taper matches the taper of the outer wall of the sealing frustum.

[0009] Preferably, the buffer, compression spring and sealing plug are coaxially arranged, and the axis of the sealing plug coincides with the axis of the exhaust port.

[0010] Preferably, the sealing ring and the sealing plug are an integral structure.

[0011] Preferably, the four vent holes of the release housing are symmetrically distributed around the axis.

[0012] Preferably, the arc-extinguishing cavity shell has a wall thickness of 2-4 mm, and the protective shell has a wall thickness of 1.5-3 mm.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model, through the adoption of a double-layer explosion-proof shell structure with specific parameters, forms a dual explosion-proof mechanism of physical isolation and chemical inhibition. This structure significantly increases the explosion-proof pressure resistance of the shell. By absorbing arc energy through the inert gas layer, it effectively prevents the internal explosion from propagating to the external environment. When the pressure inside the shell is too high, the airflow pushes the sealing block backward and generates an annular conical gap. The airflow is discharged from the exhaust port through the gap, effectively preventing the accumulation of high-temperature gas inside the shell and causing secondary deflagration, thereby ensuring the stable operation of the distribution box. 2. This utility model features a heat dissipation ring snapped into the exhaust port, with both ends extending into the inner cavity of the arc-extinguishing chamber and the mounting cavity, respectively. This structure integrates the heat dissipation and pressure relief structures. During normal operation of the circuit breaker, the arc heat in the arc-extinguishing chamber is guided to the exhaust port through the heat dissipation ring and the sealing ring, reducing the temperature of the hot spot area. During pressure relief, the airflow pushes the sealing block backward, and the airflow is discharged from the exhaust port through the gap. At the same time, the release shell, the arc-extinguishing chamber shell, and the protective shell are integrally cast. The inert gas filling layer between the double-layer explosion-proof shell and the release shell is seamlessly connected, so that the entire circuit breaker shell is completely covered by a nitrogen barrier. This achieves a deep integration of explosion protection, heat dissipation, and pressure relief, while ensuring the compactness of the overall structure. It is suitable for high-density distribution box environments, achieving a balance between safety and space utilization. Attached Figure Description Figure 1 This is an isometric view of the overall structure of this utility model; Figure 2 This is a cross-sectional view of the overall structure of this utility model; Figure 3 This is a cross-sectional plan view of the overall structure of this utility model; Figure 4 This is a diagram showing the operating state of the pressure relief valve of this utility model. Figure 5 This is an isometric view of the heat dissipation ring of this utility model.

[0014] In the diagram: 1. Double-layer explosion-proof enclosure; 2. Arc-extinguishing chamber shell; 3. Protective outer shell; 4. Inert gas filling layer; 5. Connecting rib; 6. Pressure relief valve; 7. Release shell; 8. Sealing plug; 9. Exhaust hole; 10. Exhaust port; 11. Mounting cavity; 12. Buffer; 13. Sealing ring; 14. Compression spring; 15. Heat dissipation ring; 16. Push-pull gate handle. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] To address the risk of explosion hazard in existing deeply integrated circuit breakers due to the lack of explosion-proof structures and pressure relief mechanisms in the circuit breaker housing, the following technical solution is proposed. Please refer to [link / reference needed]. Figure 1-5 ; An explosion-proof circuit breaker housing structure includes a double-layer explosion-proof housing 1. The double-layer explosion-proof housing 1 includes an inner arc-extinguishing chamber housing 2 and an outer protective shell housing 3. The arc-extinguishing chamber housing 2 is made of high-strength alloy steel or ceramic material with a wall thickness of 2-4 mm. The protective shell housing 3 is made of engineering plastic or cast aluminum material with a wall thickness of 1.5-3 mm. The arc-extinguishing chamber housing 2 is used to house the core components of the circuit breaker and provide initial explosion-proof isolation.

[0017] An inert gas filling layer 4 with uniform gaps is formed between the arc-extinguishing chamber shell 2 and the protective shell 3. The gap distance of the inert gas filling layer 4 is 7mm. The inert gas filling layer 4 is filled with 0.35MPa dry nitrogen gas. The inert gas filling layer 4 absorbs the arc energy and effectively prevents the internal explosion from spreading to the external environment. The arc-extinguishing chamber shell 2 and the protective shell 3 are fixedly connected by connecting ribs 5. The connecting ribs 5 are set at the inflection point or the center of the connection surface between the arc-extinguishing chamber shell 2 and the protective shell 3 to ensure structural stability and gap consistency.

[0018] An exhaust port 10 is provided on one side of the back of the arc-extinguishing chamber shell 2 and the outer protective shell 3. A pressure relief valve 6 is fixed outside the exhaust port 10. The pressure relief valve 6 includes a release shell 7 and a sealing plug 8. The release shell 7 has a double-layer structure. The inner layer is made of the same material as the arc-extinguishing chamber shell 2, and the outer layer is made of the same material as the protective shell 3. The two layers are also filled with inert gas and connected by connecting ribs 5. Therefore, the release shell 7 can be integrally cast with the arc-extinguishing chamber shell 2 and the protective shell 3. The release shell 7 covers the exhaust port 10, which is located at the position of the arc-extinguishing chamber.

[0019] The release housing 7 has an inner cavity 11. The top, bottom and sides of the release housing 7 each have an exhaust hole 9, which is connected to the inner cavity 11. The four exhaust holes 9 are symmetrically distributed around the axis. A buffer 12 is installed in the inner cavity 11. One end of the buffer 12 is fixed to the side wall of the inner cavity 11, and the other end is connected to the center of the sealing plug 8. A compression spring 14 is installed outside the buffer 12. The compression spring 14 and the buffer 12 form a two-stage action assembly. The buffer 12, the release housing 7 and the sealing plug 8 are coaxially connected.

[0020] The sealing plug 8 has a frustum-shaped structure, and the shape of the exhaust port 10 is adapted to the sealing plug 8. The diameter of the exhaust port 10 gradually increases from the inside to the outside. A heat dissipation ring 15 is snapped into the exhaust port 10. The side wall of the heat dissipation ring 15 fits against the inner wall of the exhaust port 10. The two ends of the heat dissipation ring 15 extend to the inner cavity of the arc extinguishing chamber shell 2 and the mounting inner cavity 11, respectively. Under normal conditions, the compression spring 14 and the buffer 12 press the sealing plug 8 tightly against the inner wall of the heat dissipation ring 15 to achieve a seal.

[0021] A sealing ring 13 is provided on the side of the sealing plug 8 near the buffer 12. The diameter of the sealing ring 13 is larger than the maximum diameter of the exhaust port 10. The diameter of the sealing ring 13 is equal to the diameter of the installation cavity 11. In the sealed state, the sealing ring 13 abuts against the end edge of the heat dissipation ring 15. The sealing ring 13 and the heat dissipation ring 15 are made of high thermal conductivity alloy material. One end of the heat dissipation ring 15 conducts the heat in the inner cavity of the arc extinguishing chamber shell 2 to the other end, and continues to conduct heat through the sealing ring 13, so that the heat is finally discharged through the exhaust port 9.

[0022] The sealing ring 13 and the sealing plug 8 can be horizontally displaced along the axial direction in the installation cavity 11. Under normal conditions, the sealing plug 8 is pressed against the exhaust port 10 by the compression spring 14 and the buffer 12. When the pressure inside the arc extinguishing chamber shell 2 is greater than 0.4MPa, the airflow pushes the sealing plug 8 backward and compresses the compression spring 14 and the buffer 12. The conical gap opens in an annular shape, and the opening height Δh and the pressure P satisfy: Δh=0.02P-0.008. After the venting airflow is accelerated through the conical gap, it is decelerated and pressurized in the installation cavity 11. Finally, the venting airflow is discharged through the exhaust holes 9 on all four sides. The buffer 12 can suppress high-frequency oscillations during this process to ensure stable opening.

[0023] Working Principle: Under normal operating conditions, the double-layer explosion-proof housing 1 houses the core components of the circuit breaker through its inner arc-extinguishing chamber housing 2. The arc-extinguishing chamber housing 2 is made of high-strength alloy steel or ceramic material, providing initial explosion-proof isolation. The outer protective shell 3 is made of engineering plastic or cast aluminum, forming a uniform inert gas filling layer 4 between the two. This layer is filled with 0.35MPa dry nitrogen gas to absorb arc energy and suppress explosion propagation. The arc-extinguishing chamber housing 2 and the protective shell 3 are fixedly connected by connecting ribs 5, which are located at inflection points or the center of the connection surface to ensure structural stability and gap consistency. The exhaust port 10 is located on the back side of the arc-extinguishing chamber housing 2 and the protective shell 3, and a pressure relief valve 6 is fixed externally. The pressure relief valve 6 includes a release housing 7 and a sealing plug 8. The release housing 7 is a double-layer structure and is integrally cast with the arc-extinguishing chamber housing 2 and the protective shell 3. The release housing 7 covers the exhaust port 10 and has an installation cavity 11. An exhaust hole 9 is opened at the top, bottom, and both sides of the installation cavity 11. The sealing plug 8 has a frustum-shaped structure and is coaxially connected to the mounting cavity 11 via a two-stage action assembly formed by a buffer 12 and a compression spring 14. One end of the buffer 12 is fixed to the side wall of the mounting cavity 11, and the other end is connected to the center of the sealing plug 8. A sealing ring 13 is provided on the side of the sealing plug 8 near the buffer 12. The diameter of the sealing ring 13 is larger than the maximum diameter of the exhaust port 10 and equal to the diameter of the mounting cavity 11. Under normal conditions, the compression spring 14 and the buffer 12 press the sealing plug 8 tightly against the exhaust port 10 to achieve a seal.

[0024] When the pressure inside the arc-extinguishing chamber shell 2 exceeds 0.4 MPa due to an arc fault, a high-pressure gas flow rushes out from the exhaust port 10, pushing the sealing plug 8 backward. The compression spring 14 and the buffer 12 are compressed, resulting in an annular conical gap between the sealing plug 8 and the exhaust port 10. The gas flow accelerates through the conical gap and enters the mounting cavity 11. In the mounting cavity 11, the gas flow velocity decreases while the pressure increases. The buffer 12 suppresses high-frequency oscillations, ensuring stable opening and avoiding the risk of secondary explosion. The released gas flow is finally discharged to the external environment through the exhaust port 9, achieving safe pressure relief.

[0025] After depressurization, the rebound force of the compression spring 14 and the buffer 12 pushes the sealing plug 8 to reset, resealing the exhaust port 10. The entire process is fast and controllable. The inert environment of the inert gas filling layer 4 and the synergistic effect of the pressure relief valve 6 effectively prevent the spread of the explosion and the rupture of the casing.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0027] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. A type of explosion-proof circuit breaker housing structure, comprising a double-layer explosion-proof housing (1), characterized in that, The double-layer explosion-proof shell (1) is composed of an inner arc-extinguishing chamber shell (2) and an outer protective shell (3). The gap between the arc-extinguishing chamber shell (2) and the protective shell (3) forms an inert gas filling layer (4). The inert gas filling layer (4) is filled with dry nitrogen. An exhaust port (10) is coaxially provided on the back of the arc-extinguishing chamber shell (2) and the protective shell (3). A pressure relief valve (6) is fixedly installed on the outside of the exhaust port (10). The pressure relief valve (6) includes a release housing (7), a sealing plug (8), and a buffer (12). The release housing (7) is a double-layer structure. The release housing (7), the arc-extinguishing chamber shell (2), and the protective shell (3) are integrally cast. The release housing (7) covers the outside of the exhaust port (10). The release housing (7) has an installation cavity (11) inside, and an exhaust hole (9) is opened at the top, bottom, and sides. One end of the buffer (12) is fixed to the side wall of the installation cavity (11), and the other end is connected to the center of the frustum-shaped sealing plug (8). A compression spring (14) is coaxially sleeved on the outside of the buffer (12). A heat dissipation ring (15) is snapped into the exhaust port (10). The side wall of the heat dissipation ring (15) is in contact with the inner wall of the exhaust port (10). The two ends of the heat dissipation ring (15) extend to the inner cavity of the arc-extinguishing chamber shell (2) and the installation cavity (11), respectively.

2. The explosion-proof circuit breaker housing structure according to claim 1, characterized in that, The arc-extinguishing cavity shell (2) and the protective shell (3) are fixedly connected by a connecting rib (5), which is located at the inflection point or the center of the connecting surface of the arc-extinguishing cavity shell (2) and the protective shell (3).

3. The explosion-proof circuit breaker housing structure according to claim 2, characterized in that, The sealing plug (8) is coaxially fixed to a sealing ring (13) on the side near the buffer (12). The diameter of the sealing ring (13) is greater than the maximum diameter of the exhaust port (10) and equal to the diameter of the mounting cavity (11).

4. The explosion-proof circuit breaker housing structure according to claim 3, characterized in that, The inner diameter of the exhaust port (10) gradually increases from the inside to the outside, and its taper matches the taper of the outer wall of the truncated cone of the sealing plug (8).

5. The explosion-proof circuit breaker housing structure according to claim 4, characterized in that, The buffer (12), compression spring (14) and sealing plug (8) are coaxially arranged, and the axis of the sealing plug (8) coincides with the axis of the exhaust port (10).

6. The explosion-proof circuit breaker housing structure according to claim 5, characterized in that, The sealing ring (13) and the sealing plug (8) are an integral structure.

7. The explosion-proof circuit breaker housing structure according to claim 6, characterized in that, The four vent holes (9) of the release housing (7) are symmetrically distributed around the axis.

8. The explosion-proof circuit breaker housing structure according to claim 7, characterized in that, The arc-extinguishing chamber shell (2) has a wall thickness of 2-4 mm, and the protective shell (3) has a wall thickness of 1.5-3 mm.

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