A molded case circuit breaker

Abstract

This invention discloses a molded case circuit breaker, relating to the field of circuit breaker technology. It includes a housing, an air jet assembly disposed at the bottom inner part of the housing, a guide assembly disposed at the output end of the air jet assembly, including a stop block and a baffle. When manually disconnected, the gas input to the air jet assembly flows upward through the transmission section under the guidance of the stop block. When an overload occurs, the gas input to the air jet assembly cools the bimetallic strip at the bottom of the baffle and then flows upward. A shunt assembly disposed at the top of the guide assembly includes a conduction cavity. When a short circuit occurs, the gas input to the air jet assembly flows upward along the arc-extinguishing chamber after passing through the conduction cavity. The gas cleans the transmission section, preventing carbon black and metal particles generated by the arc in the arc-extinguishing chamber from adhering to the surface of the transmission section and causing jamming or failure. The gas cools and resets the bimetallic strip. After the arc is lengthened and cooled, it interacts with the metal grid in the arc-extinguishing chamber, effectively preventing arc escape and potential safety hazards.

Description

Technical Field

[0001] This invention relates to the field of circuit breaker technology, and in particular to a molded case circuit breaker. Background Technology

[0002] Molded case circuit breakers are core switching devices used in low-voltage power distribution systems for overload and short-circuit protection of lines and equipment. All core components are housed in flame-retardant engineering plastic housings, resulting in a compact structure and excellent protection. Their main function is to automatically disconnect the power supply when an overload or short circuit occurs, thus protecting the lines and downstream electrical equipment from damage. As a result, they have become the mainstay in power distribution networks in industrial, commercial, and large buildings.

[0003] Chinese Patent Publication No. CN120376379A discloses a plastic-cased circuit breaker, including a housing, a tripping mechanism, and a contact assembly. The contact assembly includes a moving contact and a stationary contact, and also includes an overload protection mechanism. The overload protection mechanism includes a first double bimetallic strip and a time delay component. The first double bimetallic strip is vertically arranged, with its lower end connected to the moving contact and its upper end corresponding to the tripping mechanism.

[0004] The above-mentioned technical solutions have some problems in use. The high-temperature and high-voltage arc generated by the separation of circuit breaker contacts can seriously affect the performance of the casing. The arc in the arc-extinguishing chamber produces carbon black and metal particles that flow into the transmission part and adhere to the surface of the transmission part, causing jamming or failure. After an overload in industrial production, the operator needs to close the circuit and restore operation, but the high-temperature deformation of the bimetallic strip does not reset and hinders the closing action. During the process of contact separation caused by a current short circuit, a huge arc is generated. The large amount of arc can easily cause concentrated ablation and lead to safety hazards. Furthermore, although the arc problem in the arc-extinguishing chamber is solved by the flow of gas inside the casing, it cannot be extinguished in time and sufficiently when the arc increases due to the increase in input current during manual power-off.

[0005] Therefore, it is necessary to invent a molded case circuit breaker to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a molded case circuit breaker to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a molded case circuit breaker, comprising a housing, an operating mechanism disposed inside the housing, the operating mechanism comprising a bimetallic strip and an arc-extinguishing chamber, and further comprising: The jet assembly, located at the bottom inner part of the housing, inflates the interior of the housing during power outages. The guiding component, located at the output end of the jet assembly and on top of the bimetallic strip, includes a baffle and a baffle. When the power is manually cut off, the gas input to the jet assembly flows upward under the guidance of the baffle. When the power is cut off due to overload, the gas input to the jet assembly cools the bimetallic strip at the bottom of the baffle and then flows upward. The diversion assembly is located on top of the guide assembly and at the bottom of the trip unit. It includes a conduction chamber. When the short circuit is interrupted, the gas input from the jet assembly flows upward along the arc-extinguishing chamber after passing through the conduction chamber. An exhaust assembly, located on top of the guide assembly, includes a pressure relief port and a temperature control port for outputting the gas input to the jet assembly.

[0008] Preferably, the operating mechanism further includes a handle, a transmission part, a latch, a contact, and a trip unit; a partition is fixedly connected inside the housing, the partition is located between the transmission part and the trip unit, and gas flows upward through the right side of the partition during overload power failure.

[0009] Preferably, the jet assembly includes: An air pump is fixedly installed at the bottom of the housing, and a one-way air outlet is provided on one side of the air pump. The top plug is slidably connected to the inside of the air cylinder. A reset component is installed between the side of the top plug and the inside of the air cylinder. The top plug has a one-way air inlet. A push rod is fixedly connected to the end of the top plug. The push rod corresponds to the one-way air outlet and is directly opposite the lock. When the handle is dropped, it drives the top plug to push the gas inside the air cylinder out through the one-way air outlet. When the top plug moves to its maximum value, the push rod extends through the one-way air outlet and contacts one end of the lock.

[0010] Preferably, the guiding component further includes: The temperature sensing element is fixed to the inner bottom of the housing, and the sensing position of the temperature sensing element is slidably connected to the side of the bimetallic strip. The temperature sensing element senses the temperature change of the bimetallic strip. If the temperature rises, it will drive the baffle to move upward so that the gas passes between the bimetallic strip and the baffle. A vent is located at the top of the baffle, through which gas between the bimetallic strip and the baffle is discharged upwards.

[0011] Preferably, the block is fixedly connected to the top of the temperature sensing element, the baffle is fixed inside the housing, both the block and the baffle are located on the top of the bimetallic strip, and the side of the block is slidably connected to one end of the baffle.

[0012] Preferably, the splitter component further includes: The pressure plate is fixedly connected to the output end of the trip unit. The trip unit moves downward to press the pressure plate. An elastic element is fixedly connected between the pressure plate and the baffle. The pressure plate moves down to compress the elastic element to open the obstruction to the conduction cavity. The conduction cavity is located at the top of the baffle, and the output end of the conduction cavity is connected to the arc-extinguishing chamber, allowing some gas to be discharged from bottom to top through the conduction cavity via the bottom of the arc-extinguishing chamber.

[0013] Preferably, the pressure relief hole is installed on the housing on the side of the arc-extinguishing chamber. When the internal pressure of the housing increases to a preset value, the pressure relief hole opens to release air. The temperature control hole is installed on the housing at the top of the contact. As the temperature rises, the opening of the temperature control hole gradually decreases until it closes.

[0014] Preferably, the handle is rotatably connected to the side of the housing, the output end of the handle is connected to the transmission part, the output end of the transmission part is connected to the contact, the input end of the transmission part is connected to the latch, one end of the latch is in contact with the output end of the trip unit, the other end of the latch corresponds to one end of the bimetallic strip, the bimetallic strip is fixedly connected to the inner bottom of the housing, and the arc extinguishing chamber is located below the contact.

[0015] Preferably, the input end of the contact is in contact with the input end of the housing, the output end of the contact is electrically connected to the input end of the trip unit, the output end of the trip unit is electrically connected to the input end of the bimetallic strip, and the output end of the bimetallic strip is fixedly connected to the output end of the housing.

[0016] The technical effects and advantages of this invention are as follows: 1. In this invention, the pressure relief hole and the temperature control hole work together to release pressure during manual power-off, overload power-off and short circuit power-off processes, ensuring rapid pressure relief inside the shell to stabilize the shell and prevent excessive internal pressure from causing the plastic shell to crack.

[0017] 2. In this invention, the gas is cleaned by the transmission part, and the gas flow prevents the gas inside the arc-extinguishing chamber from flowing out in reverse, thereby preventing the carbon black and metal particles generated by the electric arc in the arc-extinguishing chamber from adhering to the surface of the transmission part and causing jamming or failure.

[0018] 3. In this invention, gas is used to cool and reset the bimetallic strip, so that the bimetallic strip can be quickly reset after being subjected to action, and can be quickly reconnected after being disconnected due to overload. This is suitable for industrial production and prevents disruption to normal production.

[0019] 4. In this invention, different amounts of gas are used to guide the electric arc under different conditions, so that the electric arc can fully enter the arc-extinguishing chamber and be quickly extinguished by the metal grid, thus ensuring the stability of the contact disconnection process.

[0020] 5. In this invention, during the short-circuit power-off process, by introducing an auxiliary airflow at a certain angle to the direction of arc movement, a pressure gradient adjustment is formed on the arc, which induces the arc to enter the metal grid plate more stably for arc extinguishing, thus avoiding the arc from escaping and causing safety hazards. Attached Figure Description

[0021] Figure 1This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of the operating mechanism structure of the present invention; Figure 4 This is a schematic diagram of the exhaust assembly structure of the present invention; Figure 5 This is a cross-sectional structural diagram of the present invention; Figure 6 For the present invention Figure 4 Enlarged structural diagram at point A in the middle; Figure 7 This is a schematic diagram of the guiding component structure of the present invention; Figure 8 This is a schematic diagram of the shunt component structure of the present invention.

[0022] In the diagram: 1. Housing; 2. Operating mechanism; 201. Handle; 202. Transmission unit; 203. Lock; 204. Contact; 205. Trip device; 206. Bimetallic strip; 207. Arc extinguishing chamber; 3. Jet assembly; 301. Air cylinder; 302. Top plug; 303. Reset component; 304. One-way air inlet; 305. One-way air outlet; 306. Push rod; 4. Guide assembly; 401. Temperature sensing element; 402. Stop block; 403. Baffle; 404. Ventilation groove; 5. Partition plate; 6. Diverter assembly; 601. Pressure plate; 602. Elastic element; 603. Conducting cavity; 7. Exhaust assembly; 701. Pressure relief hole; 702. Temperature control hole. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1 In the operation of a molded case circuit breaker, the arc generated when the contacts 204 separate can create a high-temperature, high-pressure environment in the arc-extinguishing chamber 207, which can easily cause the casing 1 to crack, seriously affecting its safety performance. Furthermore, the arc in the arc-extinguishing chamber 207 produces carbon black and metal particles, which, under the high pressure, can flow into the transmission part 202 and adhere to its surface, causing it to jam or fail. Additionally, if the high-temperature air from an overload interruption flows into the transmission part 202, it will affect the active connection between the molded case circuit breaker 1 and the transmission part 202. If jamming occurs, it is difficult to guarantee the precise operation of the subsequent transmission part 202. After industrial production overload, the staff will quickly unload some non-core loads and then immediately try to close the circuit to restore operation. If the bimetallic strip 206 is not sufficiently cooled and reset at this time, it will hinder the operation of the latch 203 and the transmission part 202, affecting normal closing. Furthermore, the current short circuit causes a huge electric arc to be generated during the separation of the contact 204. The huge arc is prone to concentrated ablation. If the arc is not sufficiently stretched and cooled before entering the arc extinguishing chamber 207, it can easily lead to the ablation and deformation of the metal grid, or even the arc escaping and causing safety hazards.

[0025] This invention provides, for example Figures 1 to 8 The molded case circuit breaker shown includes a housing 1, and an operating mechanism 2 is provided inside the housing 1. The operating mechanism 2 includes a handle 201, a transmission part 202, a latch 203, a contact 204, a trip unit 205, a bimetallic strip 206, and an arc-extinguishing chamber 207. The top port of the housing 1 is connected to an external input line, and the bottom port of the housing 1 is electrically connected to an external output line.

[0026] The handle 201 is rotatably connected to the side of the housing 1. The output end of the handle 201 is connected to the transmission part 202. The output end of the transmission part 202 is connected to the contact 204. The input end of the transmission part 202 is connected to the latch 203. One end of the latch 203 is in contact with the output end of the trip unit 205. The other end of the latch 203 corresponds to one end of the bimetallic strip 206. The bimetallic strip 206 is fixedly connected to the inner bottom of the housing 1. The arc-extinguishing chamber 207 is located below the contact 204.

[0027] The input terminal of contact 204 is in contact with the input terminal of housing 1. The output terminal of contact 204 is electrically connected to the input terminal of trip unit 205. The output terminal of trip unit 205 is electrically connected to the input terminal of bimetallic strip 206. The output terminal of bimetallic strip 206 is fixedly connected to the output terminal of housing 1. The external output current reaches trip unit 205 and then bimetallic strip 206 through contact 204, and is finally output to the external circuit at the bottom port of housing 1.

[0028] The jet assembly 3 is located at the bottom of the housing 1 and inflates the inside of the housing 1 during power failure. A partition 5 is fixedly connected inside the housing 1 and is located between the transmission part 202 and the trip unit 205. During overload power failure, the gas flows upward through the right side of the partition 5. The rotation and falling of the handle 201 pushes the jet assembly 3 to move, thereby the jet assembly 3 outputs gas into the housing 1.

[0029] The guide component 4 is located at the output end of the jet assembly 3 and on top of the bimetallic strip 206. It includes a baffle 402 and a baffle 403. When the power is manually cut off, the gas input to the jet assembly 3 flows upward through the transmission part 202 under the guidance of the baffle 402. When the power is cut off due to overload, the gas input to the jet assembly 3 cools the bimetallic strip 206 at the bottom of the baffle 403 and then flows upward.

[0030] The baffle 402 is fixedly connected to the top of the temperature sensing element 401. The side of the baffle 402 faces the output end of the air cylinder 301. The baffle 403 is fixed inside the housing 1. Both the baffle 402 and the baffle 403 are located on the top of the bimetallic strip 206. The side of the baffle 402 is slidably connected to one end of the baffle 403. During the gas flow, the gas passes over the surface of the bimetallic strip 206 and quickly carries away a large amount of heat, thereby forcibly cooling the high-temperature bimetallic strip 206, preventing the bimetallic strip 206 from being excessively deformed at high temperature, and allowing the bimetallic strip 206 to cool down and recover quickly after bending.

[0031] The guiding component 4 also includes a temperature sensing element 401, which is fixed to the inner bottom of the housing 1. The sensing position of the temperature sensing element 401 is slidably connected to the side of the bimetallic strip 206. The temperature sensing element 401 is made of materials such as shape memory alloy. The temperature sensing element 401 senses the temperature change of the bimetallic strip 206. If the temperature rises, it drives the baffle 402 to move upward, allowing gas to pass between the bimetallic strip 206 and the baffle 403. The ventilation groove 404 is opened at the top of the baffle 403. The gas between the bimetallic strip 206 and the baffle 403 is discharged upward through the ventilation groove 404 and passes through the right side of the partition 5. The temperature sensing element 401, which is close to the side of the bimetallic strip 206, senses the temperature abnormality. The baffle 402 moves upward, so that the ventilation gap between the bimetallic strip 206 and the baffle 403 is fully opened.

[0032] The diversion assembly 6 is located on top of the guide assembly 4 and at the bottom of the trip unit 205. It includes a conduction chamber 603. When the short circuit is interrupted, the gas input by the jet assembly 3 is discharged from bottom to top through the conduction chamber 603 and in the arc-extinguishing chamber 207.

[0033] The diversion assembly 6 also includes a pressure plate 601, which is fixedly connected to the output end of the trip unit 205. The trip unit 205 drives the output end to press the pressure plate 601. An elastic element 602 is fixedly connected between the pressure plate 601 and the baffle 403. The pressure plate 601 moves down to compress the elastic element 602 to open the obstruction to the conduction cavity 603. The conduction cavity 603 is opened at the top of the baffle 403. The output end of the conduction cavity 603 is connected to the arc-extinguishing chamber 207, so that some gas can be discharged from the bottom of the arc-extinguishing chamber 207 through the conduction cavity 603 from bottom to top. A portion of the gas flows to the right into the conduction cavity 603 and reaches the bottom of the arc-extinguishing chamber 207 along the inside of the conduction cavity 603.

[0034] The exhaust assembly 7, located on top of the guide assembly 4, includes a pressure relief hole 701 and a temperature control hole 702 for outputting the gas input from the jet assembly 3. Both the pressure relief hole 701 and the temperature control hole 702 are one-way holes, meaning they can only discharge the gas inside the housing 1 to the outside, preventing impurities in the external gas from entering the housing 1 and affecting the performance of the internal structure. The pressure relief hole 701 is installed on the housing 1 on the side of the arc-extinguishing chamber 207. When the internal pressure of the housing 1 increases to a preset value, the pressure relief hole 701 opens to discharge gas. The temperature control hole 702 is installed on the housing 1 at the top of the contact 204. As the temperature rises, the opening of the temperature control hole 702 gradually decreases until it closes. The temperature control hole 702, in conjunction with the pressure relief hole 701, opens to release gas, balancing the internal and external gas pressure of the housing 1. At room temperature, the temperature control hole 702 is in the open state, thereby ensuring the stability of the internal gas pressure of the housing 1.

[0035] Both the pressure relief hole 701 and the temperature control hole 702 are equipped with common temperature control and air pressure regulating components. The temperature control component mainly consists of shape memory metal located inside the housing 1 and a blocking block at the end. The blocking block misaligns and blocks the temperature control hole 702. When the internal temperature of the housing 1 rises, the shape memory metal deforms more due to heat, causing the blocking block to move. The blocking area of ​​the blocking block on the temperature control hole 702 increases, and the opening of the temperature control hole 702 gradually decreases until it closes. A one-way lever is provided on the outside of the temperature control hole 702 to achieve one-way air release. The air pressure regulating component is a baffle with its own elastic resistance. It is located on the outside of the housing 1 and elastically blocks the pressure relief hole 701. When the air pressure inside the housing 1 increases and the thrust on the baffle increases, its deformation increases, the opening of the pressure relief hole 701 increases, and the pressure relief amount increases.

[0036] In summary, during use, the top port of housing 1 is connected to the external input line, and the bottom port of housing 1 is electrically connected to the external output line. During the connection process, the handle 201 is tilted upward on the side of housing 1, so that the contact 204 contacts the top input terminal inside housing 1. The external output current is input to the contact 204 at the top port of housing 1, and reaches the top input terminal of trip unit 205 under the conduction of the electrical connection. It is then output through trip unit 205 and at the bottom output terminal of trip unit 205. The electrical connection is conducted to one end of bimetallic strip 206, and then output through bimetallic strip 206 at the other end, and finally output to the external line at the bottom port of housing 1.

[0037] by Figure 2 As a baseline, when the operator manually cuts off the power as needed, the operator pulls down the handle 201, causing it to fall to the side of the housing 1. At this time, the handle 201 rotates and falls, driving the transmission unit 202 to move. The transmission unit 202 then drives the contact 204 to move, causing the input end of the contact 204 to separate from the input end at the top of the housing 1 and cut off the power. Simultaneously, the rotation and falling of the handle 201 drives the jet assembly 3 to work. The jet assembly 3 outputs gas into the housing 1. At this time, the baffle 402 is positioned directly opposite the output end of the jet assembly 3. The gas output by the jet assembly 3 is blocked by the baffle 402 and flows obliquely upward under the guidance of the baffle 402's own side slope.

[0038] The gas flows upward and is split by the partition 5. It passes through the transmission part 202 and the trip unit 205 on both sides of the partition 5. The gas on the left side of the partition 5 passes through the transmission part 202 and cleans the inside of the transmission part 202, while the gas on the right side of the partition 5 passes through the trip unit 205 and cleans the surface of the trip unit 205. This removes impurities accumulated during operation and reduces the probability of mechanical jamming. The gas on both sides of the partition 5 flows upward. Since the internal temperature of the shell 1 is within the preset range, the temperature control hole 702 is in the open state. As a result, part of the gas is discharged from the shell 1 through the temperature control hole 702 on the side wall of the shell 1, and the other part of the gas flows to the right into the arc extinguishing chamber 207.

[0039] During the separation of the input terminal of contact 204 from the top input terminal of housing 1, the air is broken down at the moment of contact 204 separation to form a high-temperature electric arc. The electric arc is gradually introduced into the metal grid of arc-extinguishing chamber 207 and divides the long electric arc into multiple short arcs. The grid dissipates heat and cools the electric arc, reducing the temperature and the concentration of free particles, causing the electric arc to be elongated and the charged particles to diffuse. The electric arc is completely extinguished and the circuit is completely disconnected, causing the pressure relief hole 701 on the side of arc-extinguishing chamber 207 to open for pressure relief, preventing excessive internal pressure in housing 1 from causing the plastic housing 1 to crack.

[0040] Meanwhile, another portion of gas enters the arc-extinguishing chamber 207 from left to right. The gas blows the formed arc, allowing it to be better conducted to the metal grid plate of the arc-extinguishing chamber 207 for rapid arc extinguishing. This prevents the carbon black and molten metal particles generated when the arc is generated from flowing back to the transmission part 202, which could cause the subsequent action of the transmission part 202 to be stuck or fail. The gas is discharged from the housing 1 through the pressure relief hole 701 and the temperature control hole 702, respectively, to ensure rapid pressure relief inside the housing 1 and stabilize the inside of the housing 1, thereby completing the manual power-off process.

[0041] When the line load exceeds the rated standard and an overload power outage occurs, the continuously excessive overload current causes the bimetallic strip 206 to accumulate heat, and the surface temperature continues to rise. The two metal layers in the bimetallic strip 206 expand at different rates and bend towards the side with the smaller expansion coefficient. That is, the bimetallic strip 206 gradually heats up and bends upward. As time accumulates, the end of the bimetallic strip 206 that is close to the jet assembly 3 pushes one end of the latch 203, causing the latch 203 to rotate and drive the transmission part 202 to unlock and release. The transmission part 202 drives the input end of the contact 204 to quickly separate from the input end on the top of the housing 1 to cut off the circuit. At the same time, the action of the transmission part 202 drives the handle 201 to rotate and fall, causing the handle 201 to push the jet assembly 3 to output gas into the housing 1.

[0042] Furthermore, the temperature sensing element 401, which is close to the side of the bimetallic strip 206, senses an abnormal temperature. After being heated and deformed, it causes the top stop 402 to move upward. The deformation of the temperature sensing element 401 is much greater than the bending degree of the bimetallic strip 206. The bimetallic strip 206 also bends, but there is still a large gap between the bimetallic strip 206 and the baffle 403. The upward movement of the stop 402 fully opens the ventilation gap between the bimetallic strip 206 and the baffle 403. The gas output from the jet assembly 3 is directly opposite the gap between the bimetallic strip 206 and the baffle 403. During the gas flow, a large amount of heat is quickly carried away from the surface of the bimetallic strip 206, forcibly cooling the high-temperature conductive sheet and preventing the bimetallic strip 206 from being excessively deformed at high temperature. It also allows the bimetallic strip 206 to cool and recover quickly after bending, preventing the bimetallic strip 206 from obstructing the recovery action of the latch 203 and the transmission part 202.

[0043] After the gas between the bimetallic strip 206 and the baffle 403 cools the bimetallic strip 206, the gas flows upward through the vent 404. Due to the obstruction of the baffle 5, the gas only passes through the surface of the trip unit 205 on the right side of the baffle 5 and continues to flow upward along the channel on the right side of the baffle 5. This prevents the high-temperature gas generated by cooling the bimetallic strip 206 from passing through the transmission part 202 and causing the high-temperature gas to affect the active connection between the multiple sets of connecting mechanisms inside the transmission part 202 and the housing 1.

[0044] The temperature control hole 702 is completely closed under high temperature, allowing more gas to flow into the arc-extinguishing chamber 207 and fully blowing away the large arc caused by overload, so that it is fully conducted to the metal grid of the arc-extinguishing chamber 207 for rapid arc extinguishing. Meanwhile, the pressure relief hole 701 opens under the high temperature and pressure and gas promotion inside the arc-extinguishing chamber 207, and exhaust is carried out at the pressure relief hole 701 to stabilize the temperature and pressure environment inside the shell and avoid the impact of high temperature and high pressure-related failures on the safety performance of the shell 1.

[0045] When a sudden short circuit occurs and the power is cut off, the instantaneous surge current spikes dramatically. The large current flowing through the electromagnetic coil in the trip unit 205 generates an extremely strong magnetic field. The magnetic force overcomes the counterforce, and the spring instantly attracts the top armature of the connecting rod, causing the connecting rod to move downward and push the other end of the latch 203. The latch 203 rotates, causing the transmission part 202 to disengage from the locked state. The transmission part 202 drives the input end of the contact 204 to quickly separate from the input end of the top of the housing 1 to cut off the circuit. At the same time, the action of the transmission part 202 causes the handle 201 to rotate and fall, causing the handle 201 to push the jet assembly 3 to output gas into the housing 1.

[0046] Simultaneously, as the connecting rod in the trip unit 205 moves downward, it presses down on the pressure plate 601. The pressure plate 601 squeezes the intermediate elastic element 602, causing it to contract and deform and move downward. There is a gap between the pressure plate 601 and the conduction cavity 603. The channel of the conduction cavity 603, which was originally blocked by the pressure plate 601 and the elastic element 602, is completely opened. Since the heat of the bimetallic strip 206 does not have time to accumulate during the short circuit, there will be no significant temperature rise or deformation. The gas output by the jet assembly 3 flows obliquely upward under the obstruction and guidance of the baffle 402. A portion of the gas flows to the right into the conduction cavity 603 and reaches the bottom of the arc-extinguishing chamber 207 along the inside of the conduction cavity 603. Then, it rushes from bottom to top through the gap of the metal grid in the arc-extinguishing chamber 207 into the top of the arc-extinguishing chamber 207.

[0047] The width of the elastic element 602 is much larger than the width of the connecting rod in the latch 203 and the release device 205. The layout of the metal grid can be adjusted by tilting, and the tilt angle and the spacing of the metal grid are configured in the optimal ratio. The tilted metal grid will form a flow guide surface similar to a "louver", which will force the arc's trajectory to change from a simple straight line to a controlled curve, thereby achieving the path adjustment effect.

[0048] At this time, when the short-circuit contact 204 separates, the electric arc formed in the arc-extinguishing chamber 207 takes a certain amount of time to completely disappear. The reverse gas prolongs the time for the electric arc to enter the metal grid in the arc-extinguishing chamber 207, avoiding ablation and energy concentration, creating conditions for efficient arc extinguishing. In addition, the resistance and cooling effect generated by the gas enhances the stretching and cutting effect, reduces the arc's forward movement speed, and makes the metal grid equivalent to a load, gradually consuming the huge electric arc. This prolongs the contact time between the arc root and the metal grid, giving the metal grid sufficient time to divide, cool, and extinguish the arc. This prevents the electric arc from rapidly rushing into the space between the metal grids, concentrating in contact, and causing breakdown, which could burn surrounding components and lead to safety hazards.

[0049] Furthermore, the generated electric arc and gas impact will increase the gas pressure inside the housing 1. The pressure relief hole 701 opens in time to release the high-pressure gas and balance the gas pressure inside and outside the housing 1. Another part of the gas flows upward on both sides of the partition 5, passes through the inside of the transmission part 202 and the surface of the trip unit 205 to reach the inner top of the housing 1. The temperature control hole 702 is in the open state and is sufficient to completely discharge this part of the gas. The gas is discharged uniformly through the temperature control hole 702, and the circuit breaker gradually stabilizes and maintains the circuit breaking protection state. The gas inside the housing 1 is quickly discharged.

[0050] Example 2 Based on the above embodiments, the arc problem in the arc-extinguishing chamber 207 is solved by the gas flow inside the shell 1. However, during the manual power-off process, the external input current increases but does not reach the overload state. If the amount of gas reaching the arc-extinguishing chamber 207 is constant, it cannot extinguish the increased arc caused by the increased input current in a timely and sufficient manner, resulting in poor arc extinguishing effect.

[0051] Specifically, the air jet assembly 3 in a molded case circuit breaker includes an air cylinder 301, which is fixedly installed at the bottom of the housing 1. A one-way air outlet 305 is provided on one side of the air cylinder 301. A top plug 302 is slidably connected to the inside of the air cylinder 301. A reset member 303 is installed between the side of the top plug 302 and the inside of the air cylinder 301. A one-way air inlet 304 is provided on the top plug 302. A push rod 306 is fixedly connected to the end of the top plug 302. The push rod 306 has a conical structure. 6. Corresponding to the one-way air outlet 305 and facing the latch 203, the handle 201 falls down, causing the top plug 302 to push the gas inside the air cylinder 301 out through the one-way air outlet 305. When the top plug 302 moves to its maximum value, the push rod 306 extends along the one-way air outlet 305 and contacts one end of the latch 203, causing the latch 203 to rotate and cut off the power. The handle 201 rotates and lifts up, and the reset member 303 drives the top plug 302 to reset, allowing external gas to enter the air cylinder 301 through the one-way air inlet 304.

[0052] The handle 201 pushes the top plug 302 to move partially along the direction of the air cylinder 301 and move into the housing 1 to inflate it, so that the gas is discharged through the one-way air outlet 305 of the air cylinder 301. Rotating and lifting the handle 201 causes the reset member 303 to retract and reset under its own elasticity. The reset member 303 drives the top plug 302 to move out of the housing 1 along the direction of the air cylinder 301. During the resetting process of the top plug 302 moving to the left, the external gas enters the air cylinder 301 through the one-way air inlet 304 on the top plug 302 for subsequent use, thereby realizing the gas storage and discharge process.

[0053] In summary, when using it, such as Figure 6 As shown, during the power-off process, the handle 201 is rotated and falls to contact the part of the top plug 302 protruding from the housing 1 in the jet assembly 3. The handle 201 then pushes the top plug 302 to move partially along the direction of the air cylinder 301 and squeezes the gas inside the housing 1, so that the gas is discharged through the one-way air outlet 305 of the air cylinder 301, thereby realizing the above-mentioned exhaust process. During the movement of the top plug 302 to the right, the one-way air inlet 304 is in a closed state, and the reset member 303 between the air cylinder 301 and the top plug 302 is stretched to ensure that the gas accumulated in the air cylinder 301 fully enters the interior of the housing 1.

[0054] When a fire occurs outside and the circuit breaker does not malfunction, and manual power disconnection is required, simply press the top plug 302 fully against the part protruding from the housing 1. This will cause the top plug 302 to move along the direction of the air cylinder 301. When the top plug 302 drives the push rod 306 to move to its maximum value, the top plug 302 will cause the push rod 306 to extend along the one-way air outlet 305 and contact one end of the latch 203. This will cause the latch 203 to rotate, thereby unlocking and releasing the transmission part 202. The transmission part 202 will then cause the input end of the contact 204 to quickly separate from the input end on the top of the housing 1 to cut off the circuit. At the same time, the top plug 302 will push the gas inside the air cylinder 301 into the housing 1 to perform the aforementioned manual power disconnection action.

[0055] By rotating the handle 201 upwards, the operator can reset the transmission part 202 and the latch 203. The stop block 402 and the elastic element 602 remain in a blocking state on the top channel of the conduction cavity 603 and the bimetallic strip 206, respectively. At this time, the reset element 303 retracts and resets under its own elasticity. The reset element 303 drives the top plug 302 to move out of the housing 1 along the direction of the air cylinder 301. During the reset process of the top plug 302 moving to the left, the external gas enters the air cylinder 301 through the one-way air inlet 304 on the top plug 302. Gas accumulates in the air cylinder 301 on the right side of the top plug 302 for subsequent use.

[0056] During manual power-off, the external input current increases but does not reach an overload state. The bimetallic strip 206 continues to heat up but does not reach the bending degree. The temperature sensing element 401 does not make a large movement, so the stop block 402 is still in the blocking state. Since one end of the bimetallic strip 206 is close to the output end of the gas cylinder 301, the bimetallic strip 206 heats the gas output from the gas cylinder 301 to a certain extent. The gas then reaches the top of the housing 1 through the transmission part 202 and the trip unit 205. The increased temperature of the gas causes the opening of the temperature control hole 702 to decrease, thereby reducing the amount of gas discharged from the temperature control hole 702 and ensuring that more gas enters the arc extinguishing chamber 207.

[0057] Gas enters the arc-extinguishing chamber 207 from left to right. As the external input current increases, the number of arcs generated by the disconnection of the contact 204 increases. More gas blows the formed arc, allowing it to be fully conducted to the metal grid of the arc-extinguishing chamber 207 for rapid arc extinguishing. This ensures that as the external input current causes an increase in the number of arcs due to power outages, more gas enters the arc-extinguishing chamber 207 for better arc extinguishing guidance. The temperature control hole 702 discharges some gas to prevent the arc from being directly blown off, which would cause the arc to be insufficiently guided and extinguished, thus excessively damaging the contact 204 and affecting the subsequent energization process of the contact 204.

[0058] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A molded case circuit breaker, comprising a housing, wherein an operating mechanism is disposed inside the housing, the operating mechanism comprising a trip unit, a bimetallic strip, and an arc-extinguishing chamber, characterized in that, Also includes: The jet assembly, located at the bottom inner part of the housing, inflates the interior of the housing during power outages. The guiding component, located at the output end of the jet assembly and on top of the bimetallic strip, includes a baffle and a baffle. When the power is manually cut off, the gas input to the jet assembly flows upward under the guidance of the baffle. When the power is cut off due to overload, the gas input to the jet assembly cools the bimetallic strip at the bottom of the baffle and then flows upward. The diversion assembly is located on top of the guide assembly and at the bottom of the trip unit. It includes a conduction chamber. When the short circuit is interrupted, the gas input from the jet assembly flows upward along the arc-extinguishing chamber after passing through the conduction chamber. An exhaust assembly, located on top of the guide assembly, includes a pressure relief port and a temperature control port for outputting the gas input to the jet assembly; The operating mechanism also includes a handle, a transmission part, a latch, and a contact; a partition is fixedly connected inside the housing, the partition is located between the transmission part and the trip unit, and gas flows upward through the right side of the partition during overload power failure. The jet assembly includes: an air cylinder, which is fixedly installed at the bottom of the housing, and a one-way air outlet is provided on one side of the air cylinder; a top plug, which is slidably connected to the inside of the air cylinder, and a reset member is installed between the side of the top plug and the inside of the air cylinder, and a one-way air inlet is provided on the top plug, and a push rod is fixedly connected to the end of the top plug, the push rod is corresponding to the one-way air outlet and facing the lock, the handle falls down to drive the top plug to push the gas inside the air cylinder to be discharged along the one-way air outlet, and when the top plug moves to the maximum value, the push rod extends along the one-way air outlet and contacts one end of the lock; The diversion assembly further includes: a pressure plate, which is fixedly connected to the output end of the trip unit, and the trip unit moves downward to press the pressure plate; an elastic element, which is fixedly connected between the pressure plate and the baffle, and the pressure plate moves downward to compress the elastic element to open the obstruction to the conduction cavity; the conduction cavity is opened at the top of the baffle, and the output end of the conduction cavity is connected to the arc-extinguishing chamber, so that some gas can be discharged from bottom to top through the conduction cavity and the bottom of the arc-extinguishing chamber.

2. A molded case circuit breaker according to claim 1, characterized in that, The boot component also includes: The temperature sensing element is fixed to the inner bottom of the housing, and the sensing position of the temperature sensing element is slidably connected to the side of the bimetallic strip. The temperature sensing element senses the temperature change of the bimetallic strip. If the temperature rises, it will drive the baffle to move upward, so that the gas passes between the bimetallic strip and the baffle. A vent is located at the top of the baffle, through which gas between the bimetallic strip and the baffle is discharged upwards.

3. A molded case circuit breaker according to claim 2, characterized in that, The block is fixedly connected to the top of the temperature sensing element, and the baffle is fixed inside the housing. Both the block and the baffle are located on the top of the bimetallic strip, and the side of the block is slidably connected to one end of the baffle.

4. A molded case circuit breaker according to claim 1, characterized in that, The pressure relief hole is installed on the housing on the side of the arc-extinguishing chamber. When the internal pressure of the housing increases to a preset value, the pressure relief hole opens to release air. The temperature control hole is installed on the housing at the top of the contact. As the temperature rises, the opening of the temperature control hole gradually decreases until it closes.

5. A molded case circuit breaker according to claim 1, characterized in that, The handle is rotatably connected to the side of the housing. The output end of the handle is connected to the transmission part. The output end of the transmission part is connected to the contact. The input end of the transmission part is connected to the latch. One end of the latch is in contact with the output end of the trip unit. The other end of the latch corresponds to one end of the bimetallic strip. The bimetallic strip is fixedly connected to the inner bottom of the housing. The arc-extinguishing chamber is located below the contact.

6. A molded case circuit breaker according to claim 5, characterized in that, The input end of the contact is in contact with the input end of the housing, the output end of the contact is electrically connected to the input end of the trip unit, the output end of the trip unit is electrically connected to the input end of the bimetallic strip, and the output end of the bimetallic strip is fixedly connected to the output end of the housing.

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