Rail transit return difference adjustable pressure switch

Abstract

The present application belongs to the technical field of pressure switch, especially relates to a rail transit return difference adjustable pressure switch, which comprises a return difference adjustable pressure switch main body, an oval shell and a shell cover, the inner wall of the oval shell is fixedly connected with a mounting plate, the lower surface of the mounting plate is fixedly and sealingly connected with a mounting box together with the inner wall of the oval shell, and the bottom end of the return difference adjustable pressure switch main body is fixedly and embeddedly connected with the bottom end of the mounting box. The rail transit return difference adjustable pressure switch solves the problems of return difference adjustment lag, vibration easy to loosen and drift, strong electrostatic interference and poor vehicle working condition adaptability of the existing return difference adjustable pressure switch, realizes the comprehensive technical effects of return difference online dynamic adjustment, parameter self-locking anti-looseness, active electrostatic elimination and high protection level, greatly improves the control precision, operation stability and service life of the pressure switch, reduces the vehicle operation and maintenance cost, and effectively guarantees the safe and reliable operation of the rail train pneumatic system.

Description

Technical Field

[0001] This invention belongs to the field of pressure switch technology, and in particular relates to a hysteresis adjustable pressure switch for rail transit. Background Technology

[0002] The adjustable hysteresis pressure switch for rail transit is a core measurement and control component of the pneumatic control system for rail trains. It mainly consists of a pressure sensing component, a main pressure regulating mechanism, a hysteresis adjusting bolt, a microswitch, and a sealed protective housing. It can adjust the difference between the pressure action threshold and the reset threshold according to the vehicle's operating conditions. This adjustable hysteresis pressure switch is primarily installed in the equipment compartment of the rail train undercarriage and in the onboard pneumatic control circuit. It is used to monitor the pressure status of key pipelines such as the main air cylinder, brake air circuit, and pantograph air circuit in real time, converting fluid pressure signals into switching electrical signals to achieve functions such as air compressor start / stop control, brake pressure protection, and air circuit fault interlock alarm. It is a fundamental component ensuring the stable operation of the vehicle's pneumatic system and controllable driving safety, and is suitable for the harsh onboard conditions of rail trains, including wide temperature ranges, shock resistance, and continuous vibration.

[0003] Currently, existing adjustable pressure switches for rail transit generally suffer from adjustment lag. Hysteresis adjustment relies on manual tightening of external adjusting bolts using a wrench, and this work can only be carried out after the vehicle has stopped and the air pressure has been released. During vehicle operation, the hysteresis parameters cannot be dynamically adjusted according to operating conditions. Furthermore, the adjusted hysteresis accuracy is highly susceptible to continuous vehicle vibration, easily loosening the adjusting bolts and leading to parameter drift and positioning misalignment. This lag-based adjustment mode cannot adapt to the hysteresis requirements of different operating conditions such as high-speed cruising, low-speed start-stop, and multiple-unit operation. It easily causes frequent switching on and off when the pressure in the measured medium pipeline fluctuates slightly, leading to frequent start-stop of the air compressor and erosion of control contactor contacts. This not only significantly reduces the control accuracy and lifespan of the pressure switch itself, increasing vehicle maintenance frequency and costs, but also causes pressure control disorder in the vehicle's pneumatic system, easily triggering false braking alarms, traction blocking anomalies, and insufficient air supply, seriously affecting the stability and safety of rail train operation.

[0004] To address this issue, we propose a hysteresis-adjustable pressure switch for rail transit. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a hysteresis adjustable pressure switch for rail transit.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a hysteresis adjustable pressure switch for rail transit, comprising a hysteresis adjustable pressure switch body, an elliptical shell and a shell cover, wherein an mounting plate is fixedly connected to the inner wall of the elliptical shell, and an mounting box is sealed and fixedly connected to the lower surface of the mounting plate together with the inner wall of the elliptical shell; the bottom end of the hysteresis adjustable pressure switch body is fixedly embedded and connected to the bottom end of the mounting box; and a fixing through hole that mates with the inlet end of the hysteresis adjustable pressure switch body is opened on the lower surface of the mounting box. A pressure switch hysteresis control mechanism is fixedly connected to the upper surface of the mounting plate; The inner wall of the mounting box and the lower surface of the mounting plate are both fixedly connected to a partition plate; An anti-static mechanism is fixedly connected to the outer wall of the partition plate.

[0007] The partition plate divides the internal cavity of the mounting box into a protective area and a mounting area, and the main body of the hysteresis adjustable pressure switch is located inside the mounting area.

[0008] In the aforementioned adjustable pressure switch for rail transit, both ends of the elliptical housing are provided with through holes, and the walls of the two through holes are respectively fixedly connected with a first rubber sealing ring and a second rubber sealing ring. An aviation plug is fixedly connected to the inner wall of the first rubber sealing ring.

[0009] In the aforementioned adjustable pressure switch for rail transit, the pressure switch hysteresis control mechanism includes a miniature servo self-locking motor. The miniature servo self-locking motor is fixedly connected to the upper surface of the mounting plate via mounting bolts. A first gear is fixedly connected to the output end of the miniature servo self-locking motor. A circular hole for the first gear to pass through is opened on the upper surface of the mounting plate. A fixed through hole is opened on the upper surface of the mounting plate, and a connecting bearing is fixedly connected to the wall of the fixed through hole. A rotating rod is interference-fitted onto the inner wall of the connecting bearing. A second gear meshing with the first gear is fixedly fitted onto the wall of the rotating rod. The gear ratio between the first gear and the second gear is 1:5. A hexagonal block is fixedly connected to the bottom end of the rotating rod. The bottom end of the hexagonal block is fixedly connected to the inner wall of the hexagonal socket of the adjusting bolt in the main body of the adjustable pressure switch.

[0010] In the aforementioned adjustable pressure switch for rail transit, the anti-static mechanism includes a miniature ion generator. The outer wall of the miniature ion generator is fixedly connected to the outer wall of the partition plate located in the protected area. The outer wall of the partition plate has multiple first air outlets. The outer wall of the mounting box located in the mounting area has multiple second air outlets. The outer wall of the shell cover has a fixed through hole, and a first air outlet check valve is installed at the fixed through hole. The outer wall of the mounting plate located in the protected area has a fixed hole, and a first air pipe is fixedly connected to the hole wall of the fixed hole. The air inlet end of the first air pipe passes through the outer wall of the first rubber sealing ring. The outer wall of the mounting box located in the protected area has a fixed hole, and a second air pipe is fixedly connected to the hole wall of the fixed hole. The air inlet end of the second air pipe passes through the outer wall of the second rubber sealing ring. The outer walls of the first rubber sealing ring and the second rubber sealing ring respectively have pipe holes for the first air pipe and the second air pipe to pass through.

[0011] In the aforementioned adjustable pressure switch for rail transit, a second one-way valve is fixedly connected to the outlet ends of both the first and second air pipes, and an air inlet assembly is fixedly connected to the inlet ends of both the first and second air pipes.

[0012] In the aforementioned adjustable pressure switch for rail transit, the air intake assembly includes an air collection hood that is fixedly connected to the air intake end of the first air pipe. A filter screen is fixedly connected to the open end of the air collection hood, and two symmetrically distributed mounting rings are fixedly connected to the outer wall of the air collection hood.

[0013] In the aforementioned adjustable pressure switch for rail transit, a fixed base is fixedly connected to the side of the elliptical shell away from the shell cover, and two stops for limiting the side end of the mounting plate are fixedly connected to the inner wall of the shell cover.

[0014] In the aforementioned adjustable pressure switch for rail transit, a fixed edge strip is fixedly connected to the inner wall of the opening side of the elliptical shell, and a sealing ring that mates with the fixed edge strip is fixedly connected to the inner wall of the shell cover. Two symmetrically distributed countersunk holes are opened on the outer wall of the shell cover, and a limit bolt is movably sleeved on the hole wall of the countersunk hole. The outer walls of the fixed edge strip and the sealing ring are both provided with threaded through holes that mate with the limit bolts.

[0015] Compared with existing technologies, the advantages of a hysteresis adjustable pressure switch for rail transit are: 1. Through the pressure switch hysteresis control mechanism, when the rail train needs to adjust the hysteresis parameter according to the pressure fluctuation of the pipeline of the medium to be measured under different working conditions such as high-speed cruising, low-speed start-stop, and multiple-unit operation, the micro servo self-locking motor first receives the control command issued by the front control console and outputs the precise torque corresponding to the steering and turning angle, driving the first gear to rotate synchronously. The first gear transmits power to the second gear through gear meshing, and achieves deceleration and torque increase with the help of the 1:5 gear ratio, thereby driving the rotating rod to rotate smoothly under the radial support and axial limit of the connecting bearing. Finally, the hexagonal block at the bottom drives the hysteresis adjustment bolt to be turned synchronously, and the hysteresis threshold can be adjusted online. After the adjustment is completed, the power-off self-locking function of the micro servo self-locking motor can lock the output shaft rotation angle, and lock the circumferential position of the rotating rod and the hexagonal block through the gear transmission pair, forming a circumferential limit constraint on the adjustment bolt. It solves the problems of lag in traditional pressure switches that require stopping the vehicle to adjust the hysteresis and manual adjustment, as well as the problems of loosening the adjusting bolt and drifting of the hysteresis parameter caused by continuous vehicle vibration. It achieves the technical effect of online dynamic adjustment of hysteresis and parameter self-locking to prevent loosening, which greatly improves the accuracy of hysteresis adjustment and the long-term stability of parameters. It can flexibly adapt to the hysteresis requirements of different working conditions, reduce the component wear caused by frequent switching of pressure switches, and reduce vehicle operation and maintenance costs.

[0016] 2. Through the anti-static mechanism, when the adjustable pressure switch operates under continuous vehicle vibration and internal airflow friction, the micro ion generator is powered on within the protected area. The internal high-voltage discharge component causes corona discharge in the surrounding air, ionizing it to generate a large number of positive and negative charged ions. Simultaneously, during vehicle operation, the oncoming airflow first passes through a filter screen to remove dust and impurities, then flows along the corresponding air pipe through a one-way valve into the protected area, creating a positive pressure environment. The positive pressure airflow, carrying the ionized positive and negative ions, is evenly blown into the installation area through multiple first air outlets on the partition plate, ensuring full contact with the surface of the adjustable pressure switch body. The system neutralizes the static charge accumulated on the surface. Finally, the airflow carrying the remaining ions is discharged outward through the second vent and the first one-way valve on the cover. The first one-way valve can also prevent the backflow of airflow containing dust and moisture from the outside. This solves the problem of static accumulation and static interference caused by vibration and airflow friction in the vehicle environment. It avoids the defects of microswitch malfunction, measurement and control signal interference, and electronic component breakdown caused by electrostatic discharge. It achieves the technical effect of active and continuous static elimination and improves the stability of electrical operation. It ensures the accuracy and reliability of the electrical signal output of the adjustable hysteresis pressure switch and effectively extends the service life of internal precision electronic components.

[0017] 3. Through the design of the elliptical shell, mounting box, and matching sealing and protective structure, when the hysteresis adjustable pressure switch is installed in the equipment compartment under the railcar and faces harsh on-board conditions of wide temperature range, strong vibration, and high dust levels, the elliptical shell and cover are locked together by limit bolts, fixing strips, and sealing rings, forming an outer layer of closed protective space. The main body of the hysteresis adjustable pressure switch is embedded in the mounting area of ​​the mounting box, and then, with the first and second rubber sealing rings at both ends, radially seals the pipes and electrical circuits of the tested medium, effectively adding an inner layer of protective barrier. When the vehicle travels in both directions, the air intake components in the corresponding direction can collect the oncoming airflow, filter it, and inject it into the protective area to form a positive pressure environment, providing a stable airflow basis for static electricity elimination. This invention solves the problems of insufficient protection level of traditional adjustable hysteresis pressure switches, easy intrusion of dust and moisture under complex vehicle operating conditions, and easy shaking and loosening of pipeline connections. It achieves the technical effect of high protection level and strong adaptability to operating conditions, effectively isolates the corrosion of internal components by external dust and moisture, restrains pipelines to prevent loosening due to pulling, improves the overall vibration resistance and environmental adaptability of the adjustable hysteresis pressure switch, and ensures long-term stable and reliable operation of the adjustable hysteresis pressure switch under harsh vehicle operating conditions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an adjustable pressure switch for rail transit provided by the present invention; Figure 2 yes Figure 1 A schematic diagram of the structure in partial cross-section; Figure 3 yes Figure 2 A partially enlarged structural diagram; Figure 4 This is a three-dimensional structural diagram of the second gear part in a hysteresis adjustable pressure switch for rail transit provided by the present invention; Figure 5 This is a three-dimensional structural diagram of the hexagonal block portion in a hysteresis adjustable pressure switch for rail transit provided by the present invention.

[0019] In the diagram: 1. Hysteresis-adjustable pressure switch body; 2. Elliptical housing; 3. Housing cover; 4. Mounting plate; 5. Mounting box; 6. Pressure switch hysteresis control mechanism; 61. Miniature servo self-locking motor; 62. First gear; 63. Connecting bearing; 64. Rotating rod; 65. Second gear; 66. Hexagonal block; 7. Anti-static mechanism; 71. Miniature ion wind generator; 72. First air outlet; 73. Second air outlet; 74. First air outlet check valve; 75. First air pipe; 76. Second air pipe; 8. Second air outlet check valve; 9. Air inlet assembly; 91. Air collection hood; 92. Filter screen; 93. Mounting ring; 10. Divider plate; 11. Protective area; 12. Mounting area; 13. First rubber sealing ring; 14. Second rubber sealing ring; 15. Aviation plug; 16. Fixing base; 17. Stop block; 18. Fixing strip; 19. Sealing ring; 20. Limit bolt. Detailed Implementation

[0020] 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.

[0021] like Figures 1-5 As shown, a hysteresis adjustable pressure switch for rail transit includes a hysteresis adjustable pressure switch body 1, an elliptical shell 2, and a shell cover 3. An mounting plate 4 is fixedly connected to the inner wall of the elliptical shell 2. An mounting box 5 is sealed and fixedly connected to the lower surface of the mounting plate 4 and the inner wall of the elliptical shell 2. The bottom end of the hysteresis adjustable pressure switch body 1 is fixedly embedded and connected to the bottom end of the mounting box 5. A fixing through hole that matches the inlet end of the hysteresis adjustable pressure switch body 1 is opened on the lower surface of the mounting box 5. A pressure switch hysteresis control mechanism 6 is fixedly connected to the upper surface of the mounting plate 4. The pressure switch hysteresis control mechanism 6 includes a miniature servo self-locking motor 61, which is fixedly connected to the upper surface of the mounting plate 4 by mounting bolts. A first gear 62 is fixedly connected to the output end of the miniature servo self-locking motor 61. A circular hole for the first gear 62 to pass through is opened on the upper surface of the mounting plate 4. A fixing through hole is opened on the upper surface of the mounting plate 4, and a connecting bearing 63 is fixedly connected to the wall of the fixing through hole. The inner wall of the connecting bearing 63 is interference-fitted with a... The rotating rod 64 is movably connected to the connecting bearing 63. When the adjusting bolt knob of the hysteresis adjustable pressure switch body 1 is adjusted, position compensation can be performed to ensure the reliable operation of the automatic adjustment function. The rod wall of the rotating rod 64 is fixedly sleeved with a second gear 65 that meshes with the first gear 62. The gear ratio between the first gear 62 and the second gear 65 is 1:5. The bottom end of the rotating rod 64 is fixedly connected to a hexagonal block 66. The bottom end of the hexagonal block 66 is fixedly connected to the inner wall of the hexagon in the adjusting bolt of the hysteresis adjustable pressure switch body 1.

[0022] The inner wall of the mounting box 5 and the lower surface of the mounting plate 4 are fixedly connected to a partition plate 10. The partition plate 10 divides the internal cavity of the mounting box 5 into a protection area 11 and a mounting area 12. The hysteresis adjustable pressure switch body 1 is located inside the mounting area 12. Both ends of the elliptical shell 2 are provided with through holes, and the walls of the two through holes are respectively fixedly connected to a first rubber sealing ring 13 and a second rubber sealing ring 14. An aviation plug 15 is fixedly connected to the inner wall of the first rubber sealing ring 13.

[0023] An anti-static mechanism 7 is fixedly connected to one side of the partition plate 10 in the protected area 11. The anti-static mechanism 7 includes a miniature ion wind generator 71. The outer wall of the miniature ion wind generator 71 is fixedly connected to the outer wall of the partition plate 10 in the protected area 11. The outer wall of the partition plate 10 has multiple first air outlets 72. The outer wall of the mounting box 5 in the mounting area 12 has multiple second air outlets 73. The outer wall of the cover 3 has a fixing through hole, and a first air outlet one-way valve 74 is installed at the fixing through hole. The mounting plate 4 is located in the protected area 11. A fixing hole is provided on the outer wall of zone 11, and a first air pipe 75 is fixedly connected to the wall of the fixing hole. The air inlet end of the first air pipe 75 passes through the outer wall of the first rubber sealing ring 13. The mounting box 5 is located on the outer wall of the protective zone 11 and has a fixing hole, and a second air pipe 76 is fixedly connected to the wall of the fixing hole. The air inlet end of the second air pipe 76 passes through the outer wall of the second rubber sealing ring 14. The outer walls of the first rubber sealing ring 13 and the second rubber sealing ring 14 are respectively provided with pipe holes for the first air pipe 75 and the second air pipe 76 to pass through.

[0024] The first air pipe 75 and the second air pipe 76 are both fixedly connected to the air outlet end with a second air outlet one-way valve 8. The air inlet end of the first air pipe 75 and the second air pipe 76 are both fixedly connected to an air inlet assembly 9. The air inlet assembly 9 includes an air collection hood 91 fixedly connected to the air inlet end of the first air pipe 75. The opening end of the air collection hood 91 is fixedly connected to a filter screen plate 92. The outer wall of the air collection hood 91 is fixedly connected to two symmetrically distributed mounting rings 93.

[0025] A fixing seat 16 is fixedly connected to the side of the elliptical shell 2 away from the shell cover 3. Two blocks 17 for limiting the side of the mounting plate 4 are fixedly connected to the inner wall of the shell cover 3. A fixing strip 18 is fixedly connected to the inner wall of the opening side of the elliptical shell 2. A sealing ring 19 that mates with the fixing strip 18 is fixedly connected to the inner wall of the shell cover 3. Two symmetrically distributed countersunk holes are opened on the outer wall of the shell cover 3, and the walls of the countersunk holes are movably fitted with limiting bolts 20. The outer walls of the fixing strip 18 and the sealing ring 19 are both provided with threaded through holes that mate with the limiting bolts 20.

[0026] The operating principle of this invention is described as follows: When the adjustable hysteresis pressure switch is installed in the equipment compartment of the railcar: Step 1: Install the hysteresis adjustable pressure switch, such as... Figures 1-3 As shown, the device is first stably connected to the corresponding mounting position on the vehicle chassis via the fixing seat 16 and fixing bolts. The cover 3 and the elliptical shell 2 are then locked together by the limiting bolts 20, the fixing strip 18, and the sealing ring 19, achieving sealing protection of the joint surface of the elliptical shell 2. The mounting plate 4 is side-limited by the stop block 17 on the inner wall of the cover 3, ensuring the stability of the internal mounting structure. The hysteresis adjustable pressure switch body 1 is embedded in the mounting area 12 of the mounting box 5, and is entirely within the closed protective space formed by the elliptical shell 2 and the cover 3. This prevents the hysteresis adjustable pressure switch body 1 from directly contacting external dust and moisture, while also reducing direct friction between internal components and high-speed airflow from the outside, thus reducing the probability of initial static electricity accumulation.

[0027] After the housing is assembled and fixed, the medium pipeline and electrical circuit are connected in sequence: the medium pipeline to be tested on the rail train is passed through the central through hole of the second rubber sealing ring 14 and connected to the medium inlet end at the bottom of the differential adjustable pressure switch body 1, and then tightened and sealed; the elastic inner wall of the second rubber sealing ring 14 is tightly fitted with the outer wall of the medium pipeline to be tested, realizing radial sealing at the connection point, and at the same time forming radial limiting constraint on the medium pipeline to be tested, preventing the medium pipeline to be tested from continuously shaking and pulling the connection point during the operation of the rail train, preventing the connection point from loosening and sealing failure, and medium leakage, thus ensuring the stability and sealing of pressure acquisition.

[0028] After the test medium pipeline is connected, the control cable of the train head control console is plugged into the corresponding aviation plug 15 for conduction. The signal output line of the hysteresis adjustable pressure switch body 1, the control power supply line of the micro servo self-locking motor 61, and the power supply line of the micro ion wind generator 71 are all connected inside the elliptical shell 2 and then connected to the aviation plug 15. They are electrically connected to the train head control console through external wires to realize the uploading of pressure signals, the issuance of adjustment commands, and the centralized power supply control of various electrical components, ensuring the integration and wiring sealing of the device's electrical control.

[0029] Meanwhile, the first air pipe 75 and the second air pipe 76 are arranged along the front and rear directions of the vehicle, respectively. The openings of the air collection hoods 91 of the two sets of air intake components 9 correspond to the front of the two train heads, ensuring that when the rail train travels in both directions, there is oncoming airflow into the corresponding air pipe. During the vehicle's operation, the oncoming airflow first passes through the filter screen 92 to remove dust and impurities before entering the air collection hood 91, and then flows along the corresponding first air pipe 75 or second air pipe 76 through the second exhaust check valve 8 into the protective area 11 of the mounting box 5. The second exhaust check valve 8 adopts a large flow rate specification, which can reduce the air intake resistance and ensure the smoothness and stability of the airflow.

[0030] Through the combination of the aforementioned enclosed housing, sealed pipeline wiring, and directional air intake structure, a physical protective barrier is constructed for the main body 1 of the adjustable pressure switch, and a reliable connection between the medium path and the electrical path is completed. At the same time, a stable airflow foundation is provided for subsequent static electricity elimination, effectively improving the device's environmental adaptability to complex on-board working conditions.

[0031] Step 2: Dynamic adjustment of pressure switch hysteresis, such as... Figures 1-5 As shown, the pressure fluctuation amplitude and frequency of the test medium pipeline vary significantly under different operating conditions such as high-speed cruising, low-speed start-stop, and multiple-unit operation of the rail train. If the hysteresis parameter remains unchanged, frequent switching on and off may occur when the pressure fluctuates slightly, or the response may be delayed when the pressure changes significantly. Therefore, the hysteresis threshold needs to be dynamically adjusted according to the real-time operating conditions.

[0032] During operation, the main body 1 of the adjustable pressure switch collects the pressure signal of the pipeline of the medium to be tested in real time. At the same time, the pressure acquisition equipment of the vehicle pneumatic system feeds back the pipeline pressure status and vehicle operating condition signals to the front control console. The driver or the vehicle automatic control system sends control commands to the miniature servo self-locking motor 61 of the pressure switch hysteresis adjustment mechanism 6 through the aviation plug 15 according to the working conditions. After receiving the command, the micro servo self-locking motor 61 outputs a precise torque corresponding to the direction and angle of rotation, driving the first gear 62 at the output end to rotate synchronously. The hexagonal block 66 at the bottom of the rotating rod 64 is fixedly connected to the inner hexagonal groove of the adjusting bolt at the top of the adjustable pressure switch body 1, thereby driving the adjusting bolt to rotate synchronously. The first gear 62 transmits power to the second gear 65 through gear meshing, and the gear ratio between the first gear 62 and the second gear 65 is 1:5, so the transmission reduction ratio is 5, that is, the first gear 62 rotates 5 times, and the second gear 65 only rotates 1 time, achieving the purpose of speed reduction and torque increase. The second gear 65 is fixed coaxially with the rotating rod 64, and the rotating rod 64 is sleeved inside the connecting bearing 63. The connecting bearing 63 forms radial support and axial limit for the rotating rod 64, counteracting the radial runout and axial movement during rotation, and ensuring that the rotating rod 64 rotates smoothly and coaxially.

[0033] This high reduction ratio structure can significantly improve adjustment accuracy: the small rotation angle at the output end of the micro servo self-locking motor 61 is reduced by the gear pair and outputs a small angular displacement, improving the accuracy of the rotation of the adjusting bolt of the hysteresis adjustable pressure switch body 1; at the same time, the gear reduction can weaken the adjustment deviation caused by the small jitter of the output of the micro servo self-locking motor 61, reduce the backlash error caused by the gear meshing backlash, and accurately control the rotation angle of the hexagonal block 66, achieving fine control of the hysteresis adjusting bolt, effectively avoiding the defects of rough scale and excessive adjustment range of manual adjustment, and further ensuring that the hysteresis parameter adjustment is uniform, accurate and controllable.

[0034] When the micro servo self-locking motor 61 rotates forward, the adjusting bolt is screwed in to increase the difference between the action pressure and the reset pressure of the pressure switch (i.e., the hysteresis threshold); when the micro servo self-locking motor 61 rotates in reverse, the adjusting bolt is screwed out to decrease the hysteresis threshold, thereby achieving online precise adjustment of the hysteresis parameter.

[0035] After dynamic adjustment of the hysteresis parameter, it can be matched to the current operating conditions of the railcar: under high-speed cruise conditions, appropriately increasing the hysteresis can avoid frequent switching caused by small fluctuations in pipeline pressure, reduce unnecessary start-stop times of the air compressor, and reduce the burning loss of control contactor contacts; under low-speed start-stop and multiple-unit operation conditions, appropriately decreasing the hysteresis can ensure the response sensitivity of pressure control, avoid insufficient air supply or pressure exceeding limits in the pneumatic system, and ensure the working reliability of the air circuits such as brakes and pantographs.

[0036] After adjustment, the micro servo self-locking motor 61 has a built-in power-off self-locking function, which can lock the rotation position of its own output shaft. Then, through the transmission meshing of the first gear 62 and the second gear 65, it locks the circumferential position of the rotating rod 64 and the hexagonal block 66, forming a circumferential limit constraint on the adjusting bolt of the adjustable pressure switch body 1, so as to avoid the continuous vibration during the operation of the rail train causing the adjusting bolt to loosen and the hysteresis parameter to drift, thus ensuring the long-term stability and control accuracy of the hysteresis parameter.

[0037] This structure enables online dynamic adjustment of hysteresis during vehicle operation, solving the lag defects of traditional pressure switches that require stopping the vehicle to release pressure and manual adjustment. At the same time, the self-locking anti-loosening structure of the motor improves the vibration resistance stability of the parameters, significantly improving the control accuracy, working condition adaptability and service life of the pressure switch, reducing the frequency of vehicle operation and maintenance and maintenance costs, and ensuring the operational stability and safety of the rail train's pneumatic system.

[0038] Step 3: Static electricity elimination work of anti-static mechanism 7, such as... Figure 2 and Figure 3 As shown, during the operation of the pressure switch, the anti-static mechanism 7 starts working simultaneously: the micro ion air generator 71 is powered on and operates in the protection zone 11, and causes corona discharge in the surrounding air through the internal high-voltage discharge component, ionizing and generating a large number of positive and negative charged ions; the positive pressure airflow continuously injected into the protection zone 11 by the air intake component 9 blows the positive and negative ions generated by ionization evenly into the installation area 12 through multiple first air outlets 72 on the partition plate 10. The filter plate 92 in the air intake component 9 can filter impurities in the injected air, and by regularly cleaning the filter plate 92, the continuous reliability of the air intake of the air intake component 9 can be ensured. The ionized airflow is in full contact with the surface of the hysteresis adjustable pressure switch body 1, neutralizing the static charge accumulated on the surface of the switch body due to component vibration friction and internal airflow friction. The airflow in the installation area 12 carries residual ions and a small amount of heat. It flows out through multiple second air outlets 73 on the side wall of the installation box 5 into the internal cavity of the elliptical shell 2, and finally exits through the first air outlet one-way valve 74 on the shell cover 3. The first air outlet one-way valve 74 only allows the internal airflow to exit outward, which can prevent the backflow of external airflow containing dust and moisture into the shell, ensuring the cleanliness of the internal space.

[0039] In the onboard environment of rail transit vehicles, continuous vibration and airflow friction can easily lead to the accumulation of static electricity on the surface of precision electronic components such as microswitches and pressure sensing components inside the pressure switch. Electrostatic discharge can easily cause malfunctions of microswitch contacts, interference with measurement and control signals, and even breakdown and damage to electronic components. This mechanism uses positive pressure airflow to deliver ionized air to actively neutralize static electricity in the switch body within the enclosed installation space. This effectively eliminates the accumulation of static electricity in the installation area 12, preventing electrostatic discharge from interfering with or damaging the precision measurement and control components of the hysteresis adjustable pressure switch body 1, ensuring the accuracy and reliability of the switch's electrical signal output, reducing the probability of electrostatic-induced failures, and extending the service life of the internal electronic components of the switch.

[0040] This device achieves active and continuous static electricity elimination in enclosed installation spaces, solving the problems of static electricity accumulation and interference caused by vehicle vibration and airflow friction, improving the stability and anti-interference capability of the pressure switch's electrical operation, and ensuring measurement and control accuracy under complex working conditions.

[0041] The solution comprehensively addresses the core issues of existing adjustable pressure switches for rail transit, such as hysteresis adjustment lag, easy loosening and drift due to vibration, strong electrostatic interference, and poor adaptability to on-board conditions. It achieves a combination of technical effects, including online dynamic adjustment of hysteresis, parameter self-locking and anti-loosening, active electrostatic elimination, and high protection level. This significantly improves the control accuracy, operational stability, and service life of the pressure switch, reduces vehicle operation and maintenance costs, and effectively ensures the safe and reliable operation of the pneumatic system of rail trains.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 hysteresis-adjustable pressure switch for rail transit, comprising a hysteresis-adjustable pressure switch body (1), an elliptical shell (2), and a cover (3), characterized in that, An installation plate (4) is fixedly connected to the inner wall of the elliptical shell (2). The lower surface of the installation plate (4) and the inner wall of the elliptical shell (2) are sealed and fixedly connected to an installation box (5). The bottom end of the hysteresis adjustable pressure switch body (1) is fixedly embedded and connected to the bottom end of the installation box (5). The lower surface of the installation box (5) is provided with a fixed through hole that matches the inlet end of the hysteresis adjustable pressure switch body (1). The pressure switch hysteresis control mechanism (6) is fixedly connected to the upper surface of the mounting plate (4). The inner wall of the mounting box (5) and the lower surface of the mounting plate (4) are fixedly connected to a partition plate (10). An anti-static mechanism (7) is fixedly connected to the outer wall of the partition plate (10); The partition plate (10) divides the internal cavity of the mounting box (5) into a protective area (11) and a mounting area (12), and the hysteresis adjustable pressure switch body (1) is located inside the mounting area (12); The pressure switch hysteresis control mechanism (6) includes a micro servo self-locking motor (61), the output end of which is fixedly connected to a first gear (62). The upper surface of the mounting plate (4) is provided with a fixed through hole, and the wall of the fixed through hole is fixedly connected to a connecting bearing (63). The inner wall of the connecting bearing (63) is interference-fitted with a rotating rod (64). The rod wall of the rotating rod (64) is fixedly fitted with a second gear (65) that meshes with the first gear (62). The bottom end of the rotating rod (64) is fixedly connected to a hexagonal block (66). The antistatic mechanism (7) includes a micro ion wind generator (71). The outer wall of the micro ion wind generator (71) is fixedly connected to the outer wall of the partition plate (10) in the protection area (11). The outer wall of the partition plate (10) is provided with a plurality of first air outlet holes (72). The outer wall of the mounting box (5) in the installation area (12) is provided with a plurality of second air outlet holes (73). The outer wall of the shell cover (3) is provided with a fixed through hole, and a first air outlet one-way valve (74) is installed at the fixed through hole. The outer wall of the mounting plate (4) in the protection area (11) is provided with a fixed hole, and a first air pipe (75) is fixedly connected to the hole wall of the fixed hole. The outer wall of the mounting box (5) in the protection area (11) is provided with a fixed hole, and a second air pipe (76) is fixedly connected to the hole wall of the fixed hole.

2. The adjustable pressure switch for rail transit according to claim 1, characterized in that, Both ends of the elliptical shell (2) are provided with through holes, and the walls of the two through holes are respectively fixedly connected with a first rubber sealing ring (13) and a second rubber sealing ring (14). An aviation plug (15) is fixedly connected to the inner wall of the first rubber sealing ring (13).

3. The adjustable pressure switch for rail transit according to claim 1, characterized in that, The micro servo self-locking motor (61) is fixedly connected to the upper surface of the mounting plate (4) by mounting bolts. The upper surface of the mounting plate (4) is provided with a circular hole for the first gear (62) to pass through. The gear ratio between the first gear (62) and the second gear (65) is 1:

5. The bottom end of the hexagonal block (66) is fixedly connected to the inner wall of the hexagonal socket of the adjusting bolt in the body (1) of the backlash adjustable pressure switch.

4. The adjustable pressure switch for rail transit according to claim 1, characterized in that, The air inlet of the first air tube (75) passes through the outer wall of the first rubber sealing ring (13), and the air inlet of the second air tube (76) passes through the outer wall of the second rubber sealing ring (14). The outer walls of the first rubber sealing ring (13) and the second rubber sealing ring (14) are respectively provided with tube holes for the first air tube (75) and the second air tube (76) to pass through.

5. A hysteresis adjustable pressure switch for rail transit according to claim 1, characterized in that, The first air pipe (75) and the second air pipe (76) are both fixedly connected to the air outlet end with a second air outlet check valve (8), and the first air pipe (75) and the second air pipe (76) are both fixedly connected to an air inlet assembly (9).

6. A hysteresis adjustable pressure switch for rail transit according to claim 5, characterized in that, The air intake assembly (9) includes an air collection hood (91) that is fixedly connected to the air intake end of the first air pipe (75). A filter screen plate (92) is fixedly connected to the opening end of the air collection hood (91), and two symmetrically distributed mounting rings (93) are fixedly connected to the outer wall of the air collection hood (91).

7. A hysteresis adjustable pressure switch for rail transit according to claim 1, characterized in that, The elliptical shell (2) is fixedly connected to a fixing seat (16) on the side away from the shell cover (3), and the inner wall of the shell cover (3) is fixedly connected to two stops (17) for limiting the side of the mounting plate (4).

8. A hysteresis adjustable pressure switch for rail transit according to claim 1, characterized in that, The inner wall of the elliptical shell (2) is fixedly connected with a fixing strip (18), and the inner wall of the shell cover (3) is fixedly connected with a sealing ring (19) that cooperates with the fixing strip (18). The outer wall of the shell cover (3) has two symmetrically distributed countersunk holes, and the hole wall of the countersunk hole is movably fitted with a limit bolt (20). The outer walls of the fixing strip (18) and the sealing ring (19) are both provided with threaded through holes that cooperate with the limit bolt (20).

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