An air-filled sealing device for the inner cavity of an electrical control product

Abstract

This utility model discloses an internal cavity inflation and sealing device for electrical control products, including an inflation chamber and a resistance welding machine. The inflation chamber contains a support platform and a plug seat, which serve as welding electrodes for the resistance welding machine and are electrically connected to it. During production, the vent plug and the main body of the electrical control product are first placed into the inflation chamber; then, the inflation chamber is evacuated; after this, filling gas is added to the inflation chamber, and inflation is stopped when the pressure of the filling gas meets the requirements; next, the vent plug is welded and fixed to the vent of the main body of the electrical control product; finally, the filling gas in the inflation chamber is emptied, and the finished electrical control product is removed. This utility model, by performing inflation operations on the internal cavity of the electrical control product in a sealed inflation chamber and using resistance welding to seal the vent, ensures sufficient gas filling in the electrical control product, reduces the likelihood of leakage later, and extends its service life.

Description

Technical Field

[0001] This utility model belongs to the field of electrical control product manufacturing technology, specifically relating to an air-filled sealing device for the inner cavity of an electrical control product. Background Technology

[0002] In current electrical control products (such as relays, circuit breakers, transformers, contactors, etc.), the arc extinguishing medium used to extinguish the electric arc caused by load interruption is usually air, inert gas, SF6, hydrogen, nitrogen, etc., within the product's internal cavity. In existing technology, the method of filling the arc extinguishing medium is as follows: first, an injection port (a vent connecting to the internal cavity) is opened on the electrical product body; then, the arc extinguishing medium (such as hydrogen) is filled into the injection port; finally, the injection port is sealed with adhesive.

[0003] Specifically, Chinese patent CN109980504A discloses a device for filling hydrogen gas and its usage method. The device includes a frame, a vacuum pump, and a hydrogen tank. A sealing cover is mounted on the frame, and a mounting base for placing a workpiece is located inside the sealing cover. The frame has a vent that communicates with the sealed cavity, and a pipe is connected to the vent. A first control valve connects the vacuum pump to the pipe, and a second control valve connects the hydrogen tank to the pipe. The device also includes a negative pressure gauge and a pressure gauge for detecting the pressure inside the sealed cavity. In use, the sealed cavity is first evacuated, and then hydrogen gas is injected into it. Filling stops when the pressure inside the sealed space equals the external atmospheric pressure. The relay is then removed, and the injection port is sealed with adhesive. This solution effectively injects hydrogen gas into the product's internal cavity and seals the vent. However, in actual operation, the following problems may arise: The pores are sealed by injecting adhesive after the product is removed from a sealed space. Therefore, this method is only suitable for products with the same filling gas pressure as atmospheric pressure, and is ineffective for products with filling gas pressure greater than atmospheric pressure.

[0004] 2. Furthermore, sealing under atmospheric conditions requires extremely precise sealing time. Prolonged sealing can lead to hydrogen escape, compromising the required hydrogen concentration. Additionally, this method of sealing pores with adhesive is prone to aging and detachment during subsequent use, causing leaks and other problems, resulting in a relatively short overall lifespan. Summary of the Invention

[0005] The purpose of this utility model is to provide an air-filling and sealing device for the inner cavity of electrical control products, which can inflate and seal the inner cavity of electrical control products, achieve good welding sealing effect, ensure that the concentration of filling gas meets the requirements, and extend the service life of electrical control products.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: an internal cavity inflation and sealing device for an electrical control product, characterized in that it includes a resistance welding machine and an inflation chamber with a gas inlet and outlet interface; the inflation chamber is provided with a support platform for placing the main body of the electrical control product and a plug seat for placing an air hole plug; the plug seat can be raised and lowered under the drive of the plug lifting mechanism, and when it rises to the position, it can insert the air hole plug into the air hole of the main body of the electrical control product; the support platform and the plug seat respectively serve as welding electrodes of the resistance welding machine and are electrically connected to the resistance welding machine.

[0007] Furthermore, the inflation chamber includes a cooperating upper chamber and a lower chamber, with the support platform and plug seat disposed in the lower chamber.

[0008] Furthermore, an insulating gasket is provided between the support platform and the inner wall of the lower cavity.

[0009] Furthermore, the plug seat is a cylindrical seat, the lower end of which passes through the bottom surface of the lower chamber and is sealed to the lower chamber by a sealing element. The plug lifting mechanism is a lifting power cylinder, and the telescopic rod of the lifting power cylinder is fixedly connected to the lower end of the cylindrical seat.

[0010] Furthermore, the sealing element is a bellows, the cylindrical seat is placed inside the bellows, and one end of the bellows is sealed to the bottom surface of the lower chamber, while the other end is sealed to the connector or the end of the telescopic rod of the lifting power cylinder.

[0011] The beneficial effects of this invention are as follows: Using the device of this invention, the internal cavity of the electrical control product is inflated within a sealed inflation chamber. After inflation, the vent holes of the electrical control product are directly sealed within the inflation chamber. Compared with traditional methods, this method is more efficient, ensures sufficient gas volume and concentration, and provides better arc extinguishing effect. Furthermore, the vent plugs are directly welded to the vent holes of the electrical control product using resistance welding, ensuring a stable structural connection and reducing the likelihood of leakage later, thus extending the service life of the electrical control product.

[0012] This invention can be used to fill and encapsulate the internal cavities of relays, circuit breakers, transformers, contactors, and other products with arc-extinguishing gas. Compared to existing encapsulation methods, it provides a better sealing effect. Since the welding and encapsulation process is carried out in a sealed gas-filled chamber, it is also suitable for products requiring a filling gas pressure greater than atmospheric pressure, thus having a wide range of applications. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a structural diagram showing the disassembled relay body and the vent plug.

[0015] Figure 2 This is a schematic diagram of the structure of the device of this utility model.

[0016] Figure 3 This is a top view of the lower mold in the device of this utility model.

[0017] Figure 4 This is a schematic diagram of the working process of this utility model.

[0018] Figure 5 This is a schematic diagram of the air passage connection to the inflation chamber in this utility model. Detailed Implementation

[0019] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0020] This utility model discloses an air-filled sealing device for the internal cavity of electrical control products, which can be used to air-fill and seal electrical control products such as relays, circuit breakers, transformers, and contactors. This embodiment uses... Figure 1 The relay product shown is used for illustration. The relay includes a relay body K21 and an air hole plug K22. An air hole K20 is provided on the relay body K21, and the air hole plug K22 is used to seal the air hole K20.

[0021] like Figure 2-3 As shown, the internal cavity inflation and sealing device of the electrical control product includes an inflation chamber and a resistance welding machine. The inflation chamber is an openable and closable sealed space, equipped with a gas inlet / outlet port 10 connecting to the inner cavity of the inflation chamber. During production, the relay body K21 is placed in the inflation chamber, and a vacuum pump and an inflation assembly are connected to the gas inlet / outlet port; the vacuum pump can then be used to evacuate the inflation chamber and the inner cavity of the relay body; the inflation assembly can then be used to inflate the gas.

[0022] Specifically, the inflation chamber includes a cooperating upper chamber 11 and a lower chamber 12, with a gas inlet / outlet port 10 located on the lower chamber 12. Inside the lower chamber 12, there is a support platform 13 for placing the relay body K21 and a plug seat 14 for placing the vent plug K22. The plug seat 14 can move up and down under the drive of a plug lifting mechanism. When the vent plug K22 is placed on the plug seat 14 and the relay body K21 is placed on the support platform 13, the vent K20 inside the relay body K21 is directly above the vent plug K22. When the upper chamber 11 and lower chamber 12 are closed and connected, the relay body K21 is fixed in place, forming a sealed inflation chamber. Specifically, the upper chamber 11 and lower chamber 12 can be manually closed and connected. The closed docking can also be achieved through mechanical operation. For example, the lower chamber is fixedly installed on the worktable, and a power cylinder (such as a pneumatic cylinder, electric cylinder, or hydraulic cylinder) is mounted on the upper chamber via a bracket. The upper chamber 12 is mounted on the telescopic rod of the power cylinder, and the upper chamber 11 is driven by the action of the power cylinder to achieve closed docking. When the plug lifting mechanism drives the plug seat 14 to rise to the correct position, the air hole plug K22 is just installed on the air hole K20 of the relay body. The support platform 13 and the plug seat 14 serve as two welding electrodes of the resistance welding machine and are electrically connected to the resistance welding machine. When the resistance welding machine is started, it can weld and fix the air hole plug installed on the air hole of the relay body.

[0023] In actual assembly and production, conductive connectors or other unforeseen circumstances may cause a conductive circuit to form between the support platform 13 and the plug seat 14 even in the non-welding working state (i.e., the plug is in the lowest position and no product is placed on it). If this problem occurs, it will lead to welding failure during actual welding. Therefore, to ensure the normal operation of the resistance welding machine, insulating material can be added to electrically isolate the two, such as placing an insulating gasket between the support platform 13 and the inner wall of the lower chamber 14. Specifically, the insulating gasket can be a ceramic gasket made of ceramic material.

[0024] Preferably, the plug seat 14 is designed as a long cylindrical seat, with a groove on the top surface for placing the vent plug. The lower end of the cylindrical seat passes through the bottom surface of the lower chamber, and the cylindrical seat and the lower chamber are sealed by a sealing element. The plug lifting mechanism is a lifting power cylinder 16, and the plug lifting mechanism 123 is a plug lifting power cylinder, which can be an electric cylinder, a hydraulic cylinder, or a pneumatic cylinder. In this embodiment, a plug lifting pneumatic cylinder is selected as the plug lifting mechanism. The telescopic rod of the lifting power cylinder 16 is fixedly connected to the lower end of the cylindrical seat.

[0025] Specifically, the sealing element can be a bellows. During assembly, the cylindrical seat is placed inside the bellows, with one end of the bellows sealed to the bottom surface of the lower chamber and the other end sealed to the connector or the end of the telescopic rod of the lifting cylinder. Alternatively, other existing sealing methods can be used, such as a skeleton sealing ring. The key is to ensure a seal between the cylindrical seat and the lower chamber during vertical movement.

[0026] During production, first ensure that all components are stably connected, and connect the vacuum equipment and the inflation assembly to the gas inlet / outlet interface 10 through pipes and connectors.

[0027] The vacuum pumping equipment includes a forepump 201 and a molecular pump 202 that work together. A forepump valve 203 and a first vacuum gauge 204 are provided between the forepump 201 and the molecular pump 202. The forepump 201 is also connected to the gas inlet / outlet port 10 via a pipe, and a coarse pump valve 205 and a second vacuum gauge 206 are provided on the corresponding pipe. The molecular pump 202 is connected to the fine pump valve 207 and the gas inlet / outlet port 10 via pipes, and a high vacuum gauge 208 is provided on the high vacuum chamber of the molecular pump. The gas filling assembly includes a gas source 301, a pressure reducing valve 302, a gas filling valve 303, a pressure gauge 304, a first pressure sensor 305, and a second pressure sensor 306. The inflation gas source 301, pressure reducing valve 302, inflation valve 303, and gas inlet / outlet port 10 are connected sequentially via pipes. A pressure gauge 304 and a first pressure sensor 305 are installed on the pipe between the pressure reducing valve 302 and the inflation valve 303; a second pressure sensor 306 is installed on the pipe near the gas inlet / outlet port 10. The first pressure sensor 305 monitors the inflation gas source pressure to ensure a stable gas supply and provides an alarm when the gas supply is insufficient. The second pressure sensor 306 monitors the gas pressure inside the inflation chamber during inflation. An exhaust valve 401 is also connected to the gas inlet / outlet port 10, and the outlet of the exhaust valve 401 is connected to an external exhaust gas discharge pipe.

[0028] like Figure 4-5 As shown, the working process of the air-filled sealing device for the inner cavity of the electrical control product of this utility model is as follows.

[0029] S1: Place the vent plug K22 and the relay body K21, both made of stainless steel, onto the plug seat 14 and the support platform 13, respectively.

[0030] S2: After the inflation chamber is sealed, the vacuum equipment is activated to evacuate the inflation chamber and check the vacuum level. Vacuuming is complete when the set vacuum level is reached. The specific vacuuming process can be performed as follows: Close the fine evacuation valve 207 and the fore-stage valve 203, open the coarse evacuation valve 205, and start the fore-stage pump 201 to initially evacuate the product, providing a vacuum environment for the molecular pump evacuation. After reaching the initial vacuum setpoint, close the coarse evacuation valve 205 and open the fine evacuation valve 207 and the fore-stage valve 203; perform fine evacuation of the product using the molecular pump 202. After the vacuum level reaches the high vacuum setpoint, close the fine evacuation valve 207; vacuuming is complete. The initial vacuum setpoint and high vacuum setpoint involved in this process can be set according to the actual product requirements.

[0031] S3: The inflation assembly is activated to fill the inflation chamber with filling gas, and the gas pressure in the inflation chamber is monitored in real time by the second pressure sensor 306. Inflation stops when the gas pressure reaches the set pressure value. Specifically, the inflation pressure setting value can be set according to the actual product requirements.

[0032] S4: The plug lifting mechanism drives the plug seat to rise, installs the air hole plug onto the air hole of the relay body and fixes it by resistance welding, thus sealing the air hole of the relay body. S5: Open the exhaust valve 401 to empty the filling gas in the inflation chamber and remove the finished electrical control product.

[0033] Preferably, in step S3, when the gas pressure reaches the set pressure value, inflation is stopped and the pressure is maintained for a period of time. The pressure maintenance time can be set according to the actual situation (e.g., 10 seconds). During the pressure maintenance process, the pressure of the filling gas in the filling chamber is monitored. If the pressure remains within the standard range, step S4 is executed; if the pressure drops, the machine is stopped and an automatic alarm is triggered, which may indicate a leak in the filling chamber or pipeline, requiring manual intervention.

[0034] Preferably, when the filling gas contains hydrogen, to ensure safety, the concentrations of hydrogen and oxygen in the filling chamber can be detected before welding and sealing the vent holes. Specifically, in step S3, after stopping the filling, the concentrations of hydrogen and oxygen in the filling chamber are monitored to ensure they meet the requirements. If they do, step S4 is executed; otherwise, an automatic alarm is triggered to notify manual intervention.

[0035] Specifically, a hydrogen concentration detection component and an oxygen concentration detection component can be set up. The hydrogen concentration detection component detects the hydrogen and oxygen concentrations respectively. The hydrogen concentration detection component includes a hydrogen isolation valve 501, a hydrogen detection valve 502, and a hydrogen concentration sensor 503 connected in sequence; the oxygen concentration detection component includes an oxygen isolation valve 601, a hydrogen detection valve 602, and an oxygen concentration sensor 603 connected in sequence; the hydrogen isolation valve 501 and the oxygen isolation valve 601 are respectively connected to the filling chamber. The specific detection operation is as follows: before vacuuming, the first isolation valve 501, the first detection valve 502, the second isolation valve 601, and the second detection valve 602 are opened to perform vacuuming; when vacuuming is completed, the first detection valve 502 and the second detection valve 602 are closed; during the pressure holding process after filling, the first detection valve 502 and the second detection valve 602 are opened; the hydrogen and oxygen concentrations in the filling chamber are detected by the hydrogen concentration sensor 503 and the oxygen concentration sensor 603. When the hydrogen concentration is above 95% and the oxygen concentration is below 1%, the hydrogen and oxygen concentrations are considered to meet the requirements.

[0036] By incorporating an oxygen concentration detection component, the oxygen concentration is further checked after the inflation pressure reaches the required level. This allows for further confirmation of any leaks in the inflation chamber or pipeline. Combined with the second pressure sensor 306, this provides double protection, ensuring continued detection of leaks even if the second pressure sensor 306 fails. Particularly useful when the gas filling the relay cavity contains hydrogen, which can generate sparks during welding, the separate hydrogen and oxygen concentration detection components ensure that welding only proceeds when the concentrations meet requirements. This prevents leaks in the inflation chamber or pipeline from mixing with the hydrogen, thus avoiding potential accidents during welding.

[0037] This invention enables the electrical control product's internal cavity to be inflated within a sealed inflation chamber, and then the product's vents can be sealed directly within the inflation chamber, minimizing gas leakage and ensuring that the pressure and concentration of the filling gas meet the requirements.

[0038] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. An air-filling and sealing device for the inner cavity of an electrical control product, characterized in that, It includes a resistance welding machine and an inflation chamber with a gas inlet and outlet interface; the inflation chamber is provided with a support platform for placing the body of the electrical control product and a plug seat for placing the vent plug; the plug seat can be raised and lowered under the drive of the plug lifting mechanism, and when it rises to the position, it can insert the vent plug into the vent of the body of the electrical control product. The support platform and the plug seat serve as welding electrodes of the resistance welding machine and are electrically connected to the resistance welding machine.

2. The air-filled sealing device for the inner cavity of an electrical control product according to claim 1, characterized in that, The inflation chamber includes a matching upper chamber and a lower chamber, with the support platform and plug seat disposed in the lower chamber.

3. The air-filled sealing device for the inner cavity of an electrical control product according to claim 1, characterized in that, An insulating gasket is provided between the support platform and the inner wall of the lower cavity.

4. The air-filled sealing device for the inner cavity of an electrical control product according to claim 1, characterized in that, The plug seat is a cylindrical seat, the lower end of which passes through the bottom surface of the lower chamber and is sealed to the lower chamber by a sealing element. The plug lifting mechanism is a lifting power cylinder, and the telescopic rod of the lifting power cylinder is fixedly connected to the lower end of the cylindrical seat.

5. The air-filled sealing device for the inner cavity of an electrical control product according to claim 4, characterized in that, The sealing element is a bellows, the cylindrical seat is placed inside the bellows, and one end of the bellows is sealed to the bottom surface of the lower chamber, while the other end is sealed to the connector or the end of the telescopic rod of the lifting power cylinder.

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