Self-cutting protection valve for railway vehicles and method of use

Abstract

This invention discloses a self-shutdown protection valve for railway vehicles and its usage method. The protection valve includes: a movable valve core and a rotary valve core disposed within the valve body, dividing the valve body into a first air chamber, a second air chamber, and a normal pressure air chamber. The rotary valve core includes a column, with grooves on both sides for supply air chamber and exhaust air chamber, respectively. A main air passage connecting the first air chamber and the supply air chamber is disposed within the column and the extended rod. The exhaust air chamber has coaxial upper and lower holes for connecting the second air chamber and the normal pressure air chamber, respectively. A spring valve rod is provided with a regulating air passage connecting the second air chamber and the exhaust air chamber. This protection valve changes the pressure difference between the first air chamber and the exhaust air chamber by generating air pressure changes in the second air chamber according to the valve chamber's operating conditions. This, in turn, controls the axial movement of the movable valve core and switches the on / off state of the main air passage and the regulating air passage, achieving self-shutdown protection and reset. It also stops the piston rod from moving when a momentary pressure loss occurs in one end of the air chamber of the air cylinder.

Description

Technical Field

[0001] This invention belongs to the field of railway vehicle technology, and more specifically, relates to a self-shutdown protection valve for railway vehicles and its usage method. Background Technology

[0002] Currently, the driving force for the operation of functional components in railway freight cars mainly comes from air cylinders, such as brake cylinders and double-acting air cylinders. Since the working medium for these air cylinders is generally air, components for their control and safety must be connected to them in series via pipelines. As the demands for control precision and diverse control functions continue to increase, the number of components connected in this pipeline system will gradually increase. This will also increase the number of joints (interfaces) in the pipeline, undoubtedly multiplying the probability of pipeline leaks.

[0003] Practical experience with vehicles shows that piping system leaks typically occur at the connections between components and the piping system. Although these connections are usually sealed with sealing rings or PTFE tape, leaks persist due to the aging of sealing materials, the complexity of vehicle operating conditions, and the effects of thermal expansion and contraction in the external environment. This has become a key issue hindering railway freight safety and the normal operation of vehicles. Simplifying the piping system is clearly impractical given the increasing complexity and demands of current control functions. Therefore, it is essential to find an alternative technical solution to this problem.

[0004] The root cause of the vehicle malfunction due to the leakage problem is actually a momentary loss of pressure in one end of the air cylinder chamber. Therefore, another technical approach to solving the problem is: "In the event of a momentary loss of pressure in one end of the air cylinder chamber, the current state of the air cylinder can be locked in time, stopping the piston rod from moving. This avoids all the adverse effects caused by subsequent abnormal actions, buys valuable time for the formulation and implementation of problem-solving plans, and facilitates the switching of the manual air cylinder system. It also lays the foundation for reducing the cost and difficulty of handling railway freight malfunctions. Therefore, exploring the technical solution under this approach is an important and very meaningful endeavor." Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a self-shutting flow protection valve suitable for railway vehicles, which solves the problem that the piston rod continues to move even when there is a momentary loss of pressure in the air chamber at one end of the existing air cylinder.

[0006] To achieve the above objectives, the present invention provides a self-shutting protection valve suitable for railway vehicles, comprising: The valve body contains a movable valve core and a rotary valve core arranged sequentially from top to bottom. The valve body is divided into a first air chamber, a second air chamber, and an atmospheric pressure air chamber from top to bottom. The first air chamber is provided with a main air inlet, and the atmospheric pressure air chamber is provided with an air outlet. The extended rod of the rotary valve core passes through the movable valve core and the valve body and is exposed, which can drive the rotary valve core to rotate. The rotary valve core includes a column, and grooves for supply air chamber and exhaust air chamber are respectively provided on both sides of the column. The column and the extension rod are provided with a main air passage connecting the first air chamber and the supply air chamber. The valve stem has a coaxial upper hole and a lower hole on the exhaust chamber, which are used to connect the second chamber and the atmospheric pressure chamber, respectively. Both ends of the valve stem pass through the upper hole and the lower hole and are exposed. Both ends are provided with upper plugs and lower plugs for sealing the upper hole and the lower hole. The valve stem has an axial third central blind hole. The third central blind hole forms a regulating air passage connecting the second chamber and the exhaust chamber through a radial third side hole. When the movable valve core rises to block the main air passage, the regulating air passage is opened, and the exhaust air chamber is isolated from the normal pressure air chamber; When the movable valve core descends to block the regulating air passage, the main air passage is opened, and the exhaust air chamber is connected to the normal pressure air chamber.

[0007] Optionally, the valve body includes an upper valve cover, a cylinder, and a lower valve cover connected in sequence, wherein the upper valve cover and the lower valve cover are threadedly connected to the cylinder.

[0008] Optionally, the length of the spring valve stem is greater than the length of the column. When the movable valve core is pressed against the rotary valve core, the exhaust chamber is connected to the normal pressure chamber, and the first chamber is connected to the supply chamber.

[0009] Optionally, a positioning shaft is provided at the center of the bottom of the column, and the valve body is provided with a positioning seat that cooperates with the positioning shaft.

[0010] Optionally, the top of the column is provided with an axial first central blind hole, which communicates with the air supply chamber through a first side hole. The end of the extension rod near the rotary valve core is provided with an axial second central blind hole, one end of which communicates with the first central blind hole, and the other end of which communicates with the first air chamber through a second side hole. The movable valve core can rise to close the second side hole.

[0011] Optionally, the extension rod is detachably connected coaxially to the rotary valve core, so that the first central blind hole and the second central blind hole are connected.

[0012] Optionally, when the movable valve core is pressed against the rotary valve core, the lower end of the spring valve stem is provided with a gap from the bottom of the valve body.

[0013] Optionally, the upper hole is provided with an upper conical opening, and the lower hole is provided with a lower conical opening. When the upper hole and the lower hole have the same diameter, the upper plug is subjected to a greater airflow thrust than the lower plug.

[0014] Optionally, the exposed end of the extension rod is provided with a lever that can drive the rotary valve core to rotate 180°.

[0015] This invention also provides a method for using a self-shutdown protective valve for railway vehicles, comprising: The above-mentioned self-shutdown protection valve for railway vehicles has a normally open main air circuit and a normally closed regulating air circuit. s1. The air intake passes through the first air chamber and the main air passage into the air supply chamber. The air pressure in the first air chamber is greater than that in the second air chamber. The exhaust air chamber and the normal pressure air chamber are connected. s21. The intake air pressure is reduced, and the displacement of the movable valve core is adjusted to regulate the pressure difference between the first air pressure and the second air chamber; s22, The movable valve core moves to block the main air passage, and the airflow in the exhaust chamber enters the second air chamber through the regulating air passage, and the lever stops moving; s3. When the air pressure is restored, the air enters the first air chamber and drives the moving valve core to reset, and the main air circuit connects the first air chamber and the air supply chamber.

[0016] This invention provides a self-shutdown protection valve suitable for railway vehicles, the advantages of which are: The protective valve buffers pressure changes through the second air chamber. The pressure in the second air chamber changes with the valve chamber's operating conditions, thereby altering the pressure difference between the first air chamber and the exhaust air chamber. This, in turn, controls the axial movement of the movable valve core, switches the main air path from the regulating air path to the main air path, and achieves self-flow interruption protection and reset. It also stops the piston rod from moving when there is a momentary loss of pressure in the air chamber at one end of the air cylinder.

[0017] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0018] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0019] Figure 1 A schematic diagram of the structure of a self-shutdown protection valve for railway vehicles under normal conditions is shown according to an embodiment of the present invention.

[0020] Figure 2 A schematic diagram of the structure of a self-shutdown protection valve for railway vehicles under pressure loss condition is shown according to an embodiment of the present invention.

[0021] Figure 3 A schematic diagram of the valve body of a self-shutdown protection valve for railway vehicles according to an embodiment of the present invention is shown.

[0022] Figure 4 A schematic diagram of the structure of a rotary valve core for a self-shutdown protection valve for railway vehicles according to an embodiment of the present invention is shown.

[0023] Figure 5 A schematic diagram of the structure of a rotary valve core for a self-shutdown protection valve for railway vehicles according to an embodiment of the present invention is shown.

[0024] Figure 6 A schematic diagram of the structure of a movable valve core for a self-shutdown protection valve for railway vehicles according to an embodiment of the present invention is shown.

[0025] Figure 7 A schematic diagram of the structure of a self-shutting flow protection valve for railway vehicles according to an embodiment of the present invention is shown.

[0026] Explanation of reference numerals in the attached figures: 1. Valve body; 2. Moving valve core; 3. Rotating valve core; 4. Extending rod; 5. First air chamber; 6. Second air chamber; 7. Supply air chamber; 8. Exhaust air chamber; 9. Normal pressure air chamber; 10. Main air passage; 11. Regulating air passage; 12. Spring valve stem; 13. Positioning shaft. Detailed Implementation

[0027] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0028] like Figure 1-3 As shown, a self-shutting protection valve suitable for railway vehicles includes: The valve body 1 has a movable valve core 2 and a rotary valve core 3 arranged sequentially from top to bottom inside the valve body 1. The valve body 1 is divided into a first air chamber 5, a second air chamber 6 and an atmospheric pressure air chamber 9 from top to bottom. The first air chamber 5 is provided with a main air inlet, and the atmospheric pressure air chamber 9 is provided with an air outlet. The extension rod 4 of the rotary valve core 3 passes through the movable valve core 2 and the valve body 1 and is exposed, which can drive the rotary valve core 3 to rotate. The rotary valve core 3 includes a column, and grooves for supply air chamber 7 and exhaust air chamber 8 are respectively provided on both sides of the column. The column and the extension rod 4 are provided with a main air passage 10 connecting the first air chamber 5 and the supply air chamber 7. The spring valve stem 12 has a coaxial upper hole and a lower hole on the exhaust air chamber 8, which are used to connect the second air chamber 6 and the normal pressure air chamber 9, respectively. Both ends of the spring valve stem pass through the upper hole and the lower hole respectively and are exposed. Both ends are provided with upper plugs and lower plugs for sealing the upper hole and the lower hole. The spring valve stem 12 is provided with an axial third central blind hole. The third central blind hole forms a regulating air passage 11 that connects the second air chamber 6 and the exhaust air chamber 8 through a radial third side hole. When the movable valve core 2 rises to block the main air passage 10, the regulating air passage 11 is opened, and the exhaust air chamber 8 is isolated from the normal pressure air chamber 9. When the movable valve core 2 descends to block the regulating air passage 11, the main air passage 10 is opened, and the exhaust air chamber 8 is connected to the normal pressure air chamber 9.

[0029] Specifically, the second air chamber 6 buffers the air pressure change. The second air chamber 6 generates air pressure changes according to the valve chamber operating conditions, thereby changing the pressure difference between the first air chamber 5 and the exhaust air chamber 8, and thus controlling the axial lifting and lowering of the movable valve core 2, switching the on and off of the main air passage 10 and the regulating air passage 11, so as to realize self-flow interruption protection and reset.

[0030] Furthermore, the groove and the inner wall of the valve body 1 form a supply air chamber 7 and an exhaust air chamber 8. Annular sealing grooves are provided on the outer periphery of both ends of the column, and a vertical sealing groove is provided between the two sealing ring grooves to ensure the sealing of the exhaust air chamber 8 and the supply air chamber 7. The rotary valve core 3 may also remain stationary. The extended rod 4 supports the lifting and positioning of the movable valve core 2 and is used to set the main air passage 10. Only one of the main air passage 10 and the regulating air passage 11 is open at any given time.

[0031] In this embodiment, the valve body 1 includes an upper valve cover, a cylinder and a lower valve cover connected in sequence, and the upper valve cover and the lower valve cover are threadedly connected to the cylinder.

[0032] Specifically, the disassembled structure facilitates the installation of the internal valve core.

[0033] In this embodiment, the length of the spring valve rod 12 is greater than the length of the column. When the movable valve core 2 is pressed against the rotating valve core 3, the exhaust air chamber 8 is connected to the normal pressure air chamber 9, and the first air chamber 5 is connected to the supply air chamber 7.

[0034] Specifically, the length of the spring valve stem 12 is greater than the length of the column, which allows the movable valve core 2 to drive the spring valve stem 12 to move, thereby connecting the exhaust air chamber 8 and the normal pressure air chamber 9.

[0035] In this embodiment, a positioning shaft 13 is provided at the center of the bottom of the column, and the valve body 1 is provided with a positioning seat that cooperates with the positioning shaft 13.

[0036] Specifically, the stable operation of the rotary valve core 3 is ensured by the cooperation between the positioning shaft 13 and the positioning seat.

[0037] In this embodiment, the top of the column is provided with an axial first central blind hole, which is connected to the air supply chamber 7 through a first side hole. The end of the extension rod 4 near the rotary valve core 3 is provided with an axial second central blind hole, one end of which is connected to the first central blind hole, and the other end is connected to the first air chamber 5 through a second side hole. The movable valve core 2 can rise to close the second side hole.

[0038] Specifically, the main air passage 10, consisting of a first side hole, a first central blind hole, a second central blind hole, and a second side hole, connects the first air chamber 5 and the air supply chamber 7. The main air passage 10 is interrupted when the movable valve core 2 blocks the second side hole. The movable valve core 2 includes a coaxially arranged disc and a ring. The ring is used to block the main air passage 10 and is adapted to the rotation of the rotary valve core 3.

[0039] Furthermore, an annular sealing ring mounting groove is provided on the outer periphery of the disc, and an outer chamfer is provided at the top of the ring, which cooperates with the wedge-shaped sealing ring on the extension rod 4. By utilizing the displacement of the ring to block the main air passage 10, the sealing effect is further improved by the outer chamfer and the wedge-shaped sealing ring.

[0040] In this embodiment, the extension rod 4 is detachably connected to the rotary valve core 3 on the same axis, so that the first central blind hole and the second central blind hole are connected.

[0041] Specifically, the extension rod 4 and the rotary valve core 3 are detachably connected for easy assembly.

[0042] In this embodiment, when the movable valve core 2 is pressed against the rotary valve core 3, the lower end of the spring valve stem 12 is spaced apart from the bottom of the valve body 1.

[0043] Specifically, the lower end of the spring valve stem 12 does not contact the lower valve cover.

[0044] In this embodiment, the upper hole is provided with an upper conical opening and the lower hole is provided with a lower conical opening. When the diameters of the upper and lower holes are the same, the upper plug is subjected to a greater airflow thrust than the lower plug.

[0045] Specifically, the plug has a gradually expanding structure. When the movable valve core 2 is pressed onto the rotary valve core 3, an exhaust gap is formed between the lower plug and the corresponding lower cone. When the pressure is lost, because the upper and lower holes have the same diameter, the upper plug is subjected to a greater airflow thrust than the lower plug, causing the spring valve rod 12 to rise preferentially to block the normal pressure chamber 9 and the exhaust chamber 8.

[0046] In this embodiment, the exposed end of the extension rod 4 is provided with a lever handle, which can drive the rotary valve core 3 to rotate 180°.

[0047] Specifically, it facilitates switching the direction of airflow.

[0048] This invention also provides a method for using a self-shutdown protective valve for railway vehicles, comprising: The above-mentioned self-shutdown protection valve for railway vehicles has a main air circuit 10 that is normally open and a regulating air circuit 11 that is normally closed. s1. The air intake passes through the first air chamber 5 and the main air passage 10 into the air supply chamber 7. The air pressure in the first air chamber 5 is greater than the air pressure in the second air chamber 6. The exhaust air chamber 8 and the normal pressure air chamber 9 are connected. s21. When the intake air pressure is reduced, the displacement of the movable valve core 2 adjusts the pressure difference between the first air pressure 5 and the second air chamber 6. s22, the movable valve core 2 moves to block the main air passage 10, the airflow in the exhaust air chamber 8 enters the second air chamber 6 through the regulating air passage 11, and the lever stops moving; s3. The air pressure is restored, and the air enters the first air chamber 5 to drive the movable valve core 2 to reset. The main air passage 10 connects the first air chamber 5 and the air supply chamber 7.

[0049] Specifically, the wind pressure fluctuates and is unstable. Within a certain fluctuation range, the first air chamber 5 and the second air chamber 6 are dynamically balanced. When the air pressure in the first air chamber 5 weakens too much or drops to zero, the moving valve core 2 moves to block the main air passage 10. The air in the exhaust air chamber 8 flows through the regulating air passage 11 into the second air chamber 6. The lever stops moving, and the atmospheric pressure air chamber 9 and the exhaust air chamber 8 are isolated and blocked, maintaining the blocked state of the main air passage 10 until the air pressure in the first air chamber 5 recovers.

[0050] This embodiment provides a self-shutting protection valve suitable for railway vehicles, taking the vehicle's actuating air cylinder as an example: When connecting the self-shutdown protection valve to the vehicle's actuating air cylinder air circuit, connect one side air inlet of the actuating air cylinder to the air cylinder inlet, and connect the other side air inlet of the actuating air cylinder to the air cylinder exhaust port; connect the air supply pipeline to the main air inlet, and the atmospheric connection port does not require an external pipeline and is directly connected to the atmosphere.

[0051] (1) The strut of the actuating air cylinder extends: the cut-off valve on the air supply pipeline is opened, and the air source airflow enters the first air chamber 5 formed between the upper valve cover and the moving valve core 2 through the main air inlet. The airflow in the first air chamber 5 enters the air supply chamber 7 through the second side hole, the second central blind hole, the first central blind hole and the first side hole; the airflow entering the air supply chamber 7 is then sent into the actuating air cylinder through the air cylinder inlet on the valve body 1. The air pressure on the air inlet side of the actuating air cylinder gradually increases, pushing the piston to drive the strut to extend outward to perform the operation.

[0052] During piston movement, the gas in the other chamber of the air cylinder is squeezed out and flows into the exhaust chamber 8 on the side of the rotary valve core 3 through the air cylinder exhaust port on the valve body 1. At this time, the air pressure in the first chamber 5 is always greater than the air pressure in the exhaust chamber 8, and the upper end of the moving valve core 2 is under greater pressure than the lower end, so that the moving valve core 2 is always pressed tightly against the upper end face of the rotary valve core 3; the plug at the upper end of the spring valve rod 12 fits and seals the upper conical opening of the rotary valve core 3. Since the axial length of the spring valve rod 12 is greater than the axial length of the cylindrical body of the rotary valve core 3, an exhaust gap is naturally formed between the plug at the lower end of the spring valve rod 12 and the lower conical opening of the rotary valve core 3; the gas in the exhaust chamber 8 flows into the atmospheric pressure chamber 9 below the rotary valve core 3 through this exhaust gap, and is finally discharged into the atmosphere through the atmospheric port on the lower valve cover.

[0053] (2) Air cylinder lever retraction mode: Move the lever at the exposed end of the extension rod 4 to drive the rotary valve core 3 to rotate 180° relative to the valve body 1. The air supply chamber 7 and the air exhaust chamber 8 on both sides of the rotary valve core 3 will switch positions synchronously. The external pipelines of the air cylinder inlet and exhaust port on the valve body 1 remain unchanged, thus achieving seamless switching of the air cylinder inlet and exhaust flow directions. The air source inlet path, the airflow direction inside the valve, and the exhaust flow direction are consistent with the principle of the lever extension mode.

[0054] (3) Air supply link pressure loss and leakage, self-locking protection of the actuating air cylinder: When the air supply pipeline connected to the main air inlet interface leaks, the air pressure in the first air chamber 5 decreases instantaneously. The pressure change is quickly transmitted to the air inlet side cavity of the actuating air cylinder, making the air pressure in the air outlet side cavity of the air cylinder higher than the air pressure in the air inlet side. This pressure difference is synchronously fed back to the exhaust air chamber 8 connected to the air outlet of the air cylinder, forming a pressure difference state where the air pressure in the exhaust air chamber 8 is greater than the air pressure in the first air chamber 5. The airflow in the exhaust air chamber 8 acts on the upper part of the spring valve rod 12, pushing the spring valve rod 12 to move upward. Its upper end plug is separated from the upper conical mouth seal. The airflow in the exhaust air chamber 8 enters the second air chamber 6 between the moving valve core 2 and the rotating valve core 3 through the third side hole and the third central blind hole of the spring valve rod 12, thereby pushing the moving valve core 2 to move upward synchronously. After the spring valve stem 12 moves upward, its lower end plug is inserted into the lower cone opening to block the exhaust passage between the exhaust chamber 8 and the normal pressure chamber 9, so that the exhaust chamber 8 forms a pressure-maintaining and sealed state.

[0055] At the same time, the air pressure in the second air chamber 6 continuously pushes the moving valve core 2 upward until the moving valve core 2 blocks the second side hole of the extension rod 4, cutting off the main air passage 10 from the first air chamber 5 to the inside of the extension rod 4; at this time, the air passages on both sides corresponding to the air cylinder inlet and air cylinder outlet are locked and closed at the same time, and the piston of the actuating air cylinder and the lever rod remain fixed in position, realizing pressure loss self-locking protection.

[0056] After the leak is repaired and the air supply pressure is restored, the first air chamber 5 re-establishes air pressure. Relying on the air pressure difference, the movable valve core 2 is pushed down to reset. The volume of the second air chamber 6 is compressed, the spring valve rod 12 falls back, the exhaust air chamber 8 and the normal pressure air chamber 9 are reconnected, and the valve automatically returns to normal working state.

[0057] Working principle: The air supply chamber 7 and the air exhaust chamber 8 are integrated on the rotatable rotary valve core 3 column. By rotating the rotary valve core 3, the on / off switching of the air chamber and the valve body 1 interface, as well as the functions of manual pressure maintenance and air path reversal are realized.

[0058] The valve's self-shutdown and self-locking function is based on the real-time pressure difference comparison between the first air chamber 5 and the second air chamber 6. Under normal conditions, the two air chambers always maintain dynamic pressure matching. When the first air chamber 5 experiences instantaneous pressure loss and decay, the exhaust air chamber 8 quickly replenishes and builds pressure to the second air chamber 6 through the regulating air passage 11 of the spring valve rod 12, and simultaneously closes the passage from the exhaust air chamber 8 to the normal pressure air chamber 9 and isolates the main air passage 10, thereby locking the position of the air cylinder.

[0059] Pressure matching protection mechanism: Assume the pressure of the normal pressure chamber 9 is P1, the pressure of the first chamber 5 is P2, the pressure of the second chamber 6 is P3, and the pressure of the exhaust chamber 8 is P4. Normal operating conditions satisfy: P2≥P4=P3≥P1.

[0060] When the air supply pipeline leaks and loses pressure, P2 drops instantaneously, but P4 > P1 is still satisfied. When the pressure relationship changes to P4 ≥ P2 > P1, the air in the exhaust chamber 8 flows into the second chamber 6 through the regulating air passage 11 of the spring valve rod 12, while a small amount of gas is still slowly depressurized into the normal pressure chamber 9.

[0061] Because the upper conical orifice diameter of the rotary valve core 3 is larger than the lower conical orifice diameter, the effective pressure bearing area of ​​the upper end of the spring valve rod 12 is larger than that of the lower end, and the upper part is subjected to greater force than the lower part, which pushes the spring valve rod 12 to float upward; after rising, the upper air intake flow section increases, and the lower exhaust channel is gradually blocked by the plug until the exhaust air chamber 8 and the normal pressure air chamber 9 are completely separated.

[0062] After the second air chamber 6 is pressurized, a new pressure relationship is formed: P2≤P_current_exhaust_chamber=P3<P_original_exhaust_chamber, which pushes the moving valve core 2 to continue to move upward to block the main air passage 10. Thereafter, even if the pressure in the first air chamber 5 continues to decrease, it will no longer disturb the pressure stabilization state of the second air chamber 6. The pressure in the exhaust air chamber 8 and the actuating air cylinder cavity is self-balanced and locked, and the lever remains stationary without any abnormal movement.

[0063] Once the air supply is restored, the first air chamber 5 regains high pressure. Relying on the pressure difference, the moving valve core 2 moves down to reset, compressing the volume of the second air chamber 6. The spring valve rod 12 falls back to reset, and the exhaust air chamber 8 and the normal pressure air chamber 9 are reconnected. The valves return to normal operation.

[0064] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A self-shutting protection valve suitable for railway vehicles, characterized in that, include: The valve body contains a movable valve core and a rotary valve core arranged sequentially from top to bottom. The valve body is divided into a first air chamber, a second air chamber, and an atmospheric pressure air chamber from top to bottom. The first air chamber is provided with a main air inlet, and the atmospheric pressure air chamber is provided with an air outlet. The extended rod of the rotary valve core passes through the movable valve core and the valve body and is exposed, which can drive the rotary valve core to rotate. The rotary valve core includes a column, and grooves for supply air chamber and exhaust air chamber are respectively provided on both sides of the column. The column and the extension rod are provided with a main air passage connecting the first air chamber and the supply air chamber. The valve stem has a coaxial upper hole and a lower hole on the exhaust chamber, which are used to connect the second chamber and the atmospheric pressure chamber, respectively. Both ends of the valve stem pass through the upper hole and the lower hole and are exposed. Both ends are provided with upper plugs and lower plugs for sealing the upper hole and the lower hole. The valve stem has an axial third central blind hole. The third central blind hole forms a regulating air passage connecting the second chamber and the exhaust chamber through a radial third side hole. When the movable valve core rises to block the main air passage, the regulating air passage is opened, and the exhaust air chamber is isolated from the normal pressure air chamber; When the movable valve core descends to block the regulating air passage, the main air passage is opened, and the exhaust air chamber is connected to the normal pressure air chamber.

2. The self-shutdown protection valve for railway vehicles according to claim 1, characterized in that, The valve body includes an upper valve cover, a cylinder, and a lower valve cover connected in sequence, and the upper valve cover and the lower valve cover are threadedly connected to the cylinder.

3. The self-shutdown protection valve for railway vehicles according to claim 1, characterized in that, The length of the spring valve stem is greater than the length of the column. When the movable valve core is pressed against the rotating valve core, the exhaust air chamber is connected to the normal pressure air chamber, and the first air chamber is connected to the supply air chamber.

4. The self-shutdown protection valve for railway vehicles according to claim 1, characterized in that, A positioning shaft is provided at the center of the bottom of the column, and a positioning seat that cooperates with the positioning shaft is provided on the valve body.

5. The self-shutdown protection valve for railway vehicles according to claim 1, characterized in that, The top of the column is provided with an axial first central blind hole, which is connected to the air supply chamber through a first side hole. The end of the extension rod near the rotary valve core is provided with an axial second central blind hole, one end of which is connected to the first central blind hole, and the other end of which is connected to the first air chamber through a second side hole. The movable valve core can rise to close the second side hole.

6. The self-shutdown protection valve for railway vehicles according to claim 1, characterized in that, The extended rod is detachably connected coaxially to the rotary valve core, allowing the first central blind hole and the second central blind hole to communicate.

7. The self-shutdown protection valve for railway vehicles according to claim 3, characterized in that, When the movable valve core is pressed against the rotary valve core, the lower end of the spring valve stem is spaced apart from the bottom of the valve body.

8. The self-shutdown protection valve for railway vehicles according to claim 1, characterized in that, The upper hole is provided with an upper conical opening, and the lower hole is provided with a lower conical opening. When the diameters of the upper hole and the lower hole are the same, the upper plug is subjected to a greater airflow thrust than the lower plug.

9. The self-shutdown protection valve for railway vehicles according to claim 1, characterized in that, The exposed end of the extension rod is provided with a lever, which can drive the rotary valve core to rotate 180°.

10. A method for using a self-shutdown protective valve for railway vehicles, characterized in that, include: According to any one of claims 1-9, the self-shutdown protection valve for railway vehicles has a main air circuit that is normally open and a regulating air circuit that is normally closed. s1. The air intake passes through the first air chamber and the main air passage into the air supply chamber. The air pressure in the first air chamber is greater than that in the second air chamber. The exhaust air chamber and the normal pressure air chamber are connected. s21. The intake air pressure is reduced, and the displacement of the movable valve core is adjusted to regulate the pressure difference between the first air pressure and the second air chamber; s22, The movable valve core moves to block the main air passage, and the airflow in the exhaust chamber enters the second air chamber through the regulating air passage, and the lever stops moving; s3. When the air pressure is restored, the air enters the first air chamber and drives the moving valve core to reset, and the main air circuit connects the first air chamber and the air supply chamber.

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