Railway vehicle car height control hydraulic system and method

Abstract

The rail vehicle carriage height control hydraulic system has the advantages that the oil inlet pipeline and the oil outlet pipeline are separately arranged, independently controlled, the oil way structure is simplified, and maintenance and detection are facilitated; the hydraulic cylinder is selected as a single-acting cylinder, extension control is more accurate, the internal sealing structure and the oil inlet and outlet connection structure are simpler, the carriage height is accurately controlled in combination with the height adjustment requirement of the carriage and the real-time carriage height at the hydraulic cylinder connection position, the accuracy of the carriage height control and the convenience of the hydraulic system maintenance are improved, the practicality of the hydraulic system is improved, the adaptability of the hydraulic system to working conditions is improved, the connection structure reliability of the hydraulic cylinder is improved, the smoothness of the carriage height control is ensured, the adjustment error caused by the monitoring error is reduced, and therefore the accuracy of the carriage height control is improved. The application also protects a rail vehicle carriage height control method.

Description

Technical Field

[0001] This invention relates to a hydraulic system and method for controlling the height of a rail vehicle car, belonging to the technical field of rail vehicle car height adjustment. Background Technology

[0002] Some rail vehicles require adjustable car height, such as passenger rail vehicles or multi-functional overhead contact line maintenance vehicles. In passenger rail vehicles, the car floor will sink when the load increases and rise when the load decreases, necessitating timely adjustments to bring the car to the set height. In multi-functional overhead contact line maintenance vehicles, the car height, as the secondary suspension support, needs to be adjusted according to operational requirements. Rail vehicles primarily use air springs as the secondary suspension system, adjusting the car height by inflating and deflating the rubber air bladders. However, rubber air bladders have drawbacks, including high manufacturing and maintenance costs for the air source and piping, relatively heavy weight, complex piping layout, and difficulty in accurately controlling height adjustment. To simplify the structure and improve the accuracy of height adjustment, hydraulic systems are also used to adjust the height of the car body, such as CN202110106721.0-Hydraulic power unit car body lifting system and rail vehicle, CN202110548179.4-Mechatronics integrated system for active height adjustment of car body and rail vehicle, and CN202411438466.X-Hydraulic adjustment system and method for floor height of rail vehicle. However, existing hydraulic height adjustment systems have the following drawbacks: 1. Hydraulic systems have a large number of valves, making troubleshooting difficult and maintenance inconvenient.

[0003] 2. In the hydraulic system, the lifting and lowering of the car body is achieved by the extension and retraction of the hydraulic cylinder. The hydraulic cylinder is connected between the bogie and the car body. There will be a certain relative movement between the car body and the bogie. The connection structure of the hydraulic cylinder is unreliable and has poor adaptability to the movement of the car body, which affects the vibration reduction effect of the car body and reduces the smoothness of the car body height adjustment.

[0004] 3. The hydraulic system uses sensors to monitor the height of the car body, which requires monitoring the height change of the car body relative to the bogie. The lifting and lowering of the car body relative to the bogie is not vertical, but often has a certain tilt angle. If the sensor settings are not reasonable, it will affect the accuracy of monitoring and increase the error of hydraulic adjustment.

[0005] 4. During long-term use, hydraulic cylinders may experience minor oil leaks. The leaked oil may damage the wiring of the hydraulic system, posing a certain safety hazard. Summary of the Invention

[0006] The hydraulic system for controlling the height of a rail vehicle car provided by this invention features separate inlet and outlet oil lines for independent control, simplifying the oil circuit structure and facilitating maintenance and testing. The hydraulic cylinders are single-acting, resulting in more precise telescopic control. The internal sealing structure and inlet / outlet connection structure are simpler, improving the accuracy of car height control and the convenience of hydraulic system maintenance. This enhances the system's practicality, adaptability to various working conditions, and the reliability of the hydraulic cylinder connection structure, ensuring smooth car height adjustment control. It also improves the effectiveness and accuracy of monitoring, reducing adjustment errors caused by monitoring errors, thereby enhancing the accuracy of car height control. This invention also provides a method for controlling the height of a rail vehicle car.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A hydraulic system for controlling the height of a rail vehicle car includes a hydraulic cylinder connected between the car floor and the bogie, a controller for controlling the extension and retraction of the hydraulic cylinder, and a height monitoring component for detecting changes in the car height. The hydraulic cylinder is a single-acting cylinder. Its inlet is connected to an oil tank via an inlet pipe, and its outlet is connected to the oil tank via an outlet pipe. The inlet pipe, outlet pipe, and height monitoring component are each controlled by the controller. The hydraulic cylinder extends as oil enters through the inlet pipe, causing the car to rise; it compresses as oil exits through the outlet pipe, causing the car to descend.

[0008] Preferably, the hydraulic cylinder includes a cylinder barrel with its opening facing downwards, an integral piston rod that is sealed and guided to the inner wall of the cylinder barrel, and a guide seat that is sealed and fixed to the opening end of the cylinder barrel and guided to the integral piston rod. The guide seat is fixed to the floor of the carriage. The lower end of the integral piston rod extends out of the cylinder barrel and is hinged to the bogie support plate. The integral piston rod divides the inner cavity of the cylinder barrel into a rodless chamber and a rod chamber. The oil inlet pipe is connected to the oil inlet of the rodless chamber, and the oil outlet pipe is connected to the oil outlet of the rodless chamber. The cylinder barrel rises as oil enters the rodless chamber and falls as oil exits the rodless chamber.

[0009] Preferably, an oil inlet is provided at the top of the cylinder, and the oil inlet pipeline includes an oil pump controlled by a controller, an oil inlet proportional solenoid valve controlled by a controller, and an oil inlet connector mounted on the oil inlet. The oil tank, oil pump, oil inlet proportional solenoid valve and oil inlet connector are connected in sequence through oil pipes.

[0010] Preferably, the integrated piston rod has an oil discharge channel connected to the rodless chamber along its central axis. The lower end of the oil discharge channel is connected to the oil discharge port on the integrated piston rod. The oil discharge pipeline includes an oil discharge proportional solenoid valve controlled by the controller and an oil discharge connector mounted on the oil discharge port. The oil tank, the oil discharge proportional solenoid valve, and the oil discharge connector are connected in sequence through oil pipes.

[0011] Preferably, the outer edge of the top of the guide seat is a chamfered edge, and an oil-gathering ring groove is formed between the inner wall of the cylinder and the chamfered edge. An oil return channel communicating with the oil-gathering ring groove is opened on the guide seat, and an oil return connector is installed at the outer end of the oil return channel. The oil return connector is connected to the oil tank through an oil pipe.

[0012] Preferably, a bearing hole is formed at the lower end of the integrated piston rod, a universal joint bearing is press-fitted into the bearing hole, a connecting shaft is assembled into the universal joint bearing, and the connecting shaft is fixedly connected to the bogie support plate.

[0013] Preferably, the outer ring of the universal joint bearing is fitted with a dustproof sealing ring 1 at both ends, and the inner ring is fitted with a dustproof sealing ring 2 at both ends to seal the bearing hole. A retaining ring groove is opened on the inner wall of the bearing hole on both sides of the dustproof sealing ring 2. A retaining ring for the hole is installed in the retaining ring groove. A washer is placed on the outer end of the dustproof sealing ring 2. The washer and the dustproof sealing ring 2 are axially positioned between the two retaining rings for the hole.

[0014] Preferably, the height monitoring component includes a height sensor mounted on the car floor and connected to the controller signal, a height adjustment rod with its upper end hinged to the rotating handle of the height sensor, and the lower end of the height adjustment rod hinged to the bogie support plate via a universal joint. The rotating handle of the height sensor rotates as the car rises and falls.

[0015] The method for controlling the height of rail vehicle carriages uses the hydraulic system for controlling the height of rail vehicle carriages described above. In the non-adjustment state, the oil inlet and outlet pipes are normally closed, and the height of the carriage is locked. Raising the height of the cargo box: The controller controls the oil inlet pipe to open, so that the oil in the oil tank is introduced into the hydraulic cylinder through the oil inlet pipe. The hydraulic cylinder extends as the oil enters, driving the cargo box to rise. When the height monitoring component detects that the cargo box height has risen to the preset height value, the controller controls the oil inlet pipe to disconnect and lock the cargo box height. Lowering the car body height: The controller controls the oil drain line to open. Under the action of the car body's gravity, the oil in the hydraulic cylinder flows through the oil drain line to the oil tank, causing the hydraulic cylinder to compress. The car body descends as the hydraulic cylinder compresses. When the height monitoring component detects that the car body height has dropped to the preset height, the controller controls the oil drain line to disconnect, locking the car body height.

[0016] Preferably, "controller controls the oil inlet pipeline to open" means that the controller controls the oil pump to start and controls the proportional oil inlet solenoid valve to be energized and open; "controller controls the oil inlet pipeline to close" means that the controller controls the oil pump to close and controls the proportional oil inlet solenoid valve to be de-energized and close; "controller controls the oil outlet pipeline to open" means that the controller controls the proportional oil outlet solenoid valve to be energized and open; "controller controls the oil outlet pipeline to close" means that the controller controls the proportional oil outlet solenoid valve to be de-energized and close.

[0017] The beneficial effects of the invention are: The present invention relates to a hydraulic system for controlling the height of a rail vehicle car. A controller controls the inlet oil line to guide hydraulic oil to a hydraulic cylinder, causing the cylinder to extend and lift the car. The controller also controls the outlet oil line, causing the hydraulic cylinder to compress and discharge oil under the weight of the car, thus lowering the car. Controlling the inlet oil speed and flow rate adjusts the lifting speed and amount of the car, while controlling the outlet oil speed and flow rate adjusts the lowering speed and amount. The inlet and outlet oil lines are separate and independently controlled, simplifying the hydraulic circuit structure and facilitating maintenance and testing. The hydraulic cylinders are single-acting, providing more precise extension and retraction control. The internal sealing structure and inlet / outlet connection structure are simpler. By combining the car height adjustment requirements with the real-time car height at the hydraulic cylinder connection position, precise control of the car height is achieved, improving the accuracy of car height control and the convenience of hydraulic system maintenance, thus enhancing the practicality of the hydraulic system.

[0018] An oil-collecting annular groove is installed at the bottom of the rodless chamber, and a return oil channel is opened on the guide seat. Oil leaking from the rod chamber into the rodless chamber accumulates in the annular groove and flows back to the oil tank through the return oil channel. This prevents leaked oil from flowing out of the rodless chamber and causing corrosion damage to the hydraulic system wiring, reduces oil waste, lowers the failure rate of the hydraulic system, and improves its practicality. A universal joint bearing forms an integral hinge between the piston rod and the bogie support plate, allowing the hydraulic cylinder to adaptably swing when the car body rises or falls relative to the bogie in any direction. Double-layer sealing prevents sand and dust from entering the universal joint bearing, avoiding jamming caused by sand and dust, improving the hydraulic system's adaptability to working conditions, enhancing the reliability of the hydraulic cylinder's connection structure, and ensuring smooth control of the car body's height adjustment.

[0019] A height sensor with a rotating handle is used to monitor the real-time height change of the car floor. The swing angle of the rotating handle caused by the raising and lowering of the car is used as the monitoring object to form a monitoring signal. It can monitor the raising and lowering of the car relative to the bogie at any angle. The height monitoring has high adaptability, improves the effectiveness and accuracy of monitoring, reduces the adjustment error caused by monitoring error, and thus improves the precision of car height control. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the hydraulic system for controlling the height of the rail vehicle carriage according to the present invention.

[0021] Figure 2 for Figure 1 A magnified view of a portion of the image.

[0022] Figure 3 for Figure 1 Another enlarged view of a portion of the diagram.

[0023] Figure 4This is a schematic diagram showing the connection between the height monitoring component and the controller. Detailed Implementation

[0024] The following is combined Figures 1-4 The embodiments of the present invention will be described in detail below.

[0025] A hydraulic system for controlling the height of a rail vehicle car includes a hydraulic cylinder 1 connected between the car floor and the bogie, a controller 2 for controlling the extension and retraction of the hydraulic cylinder, and a height monitoring component 3 for detecting changes in the car height. The hydraulic cylinder 1 is a single-acting cylinder. The oil inlet of the hydraulic cylinder 1 is connected to an oil tank 5 via an oil inlet pipe 4, and the oil outlet is connected to the oil tank 5 via an oil outlet pipe 6. The oil inlet pipe 4, the oil outlet pipe 6, and the height monitoring component 3 are all controlled by the controller 2. The hydraulic cylinder 1 extends as oil enters through the oil inlet pipe 4, causing the car to rise. It compresses as oil is discharged through the oil outlet pipe 6, causing the car to descend as the hydraulic cylinder compresses.

[0026] The hydraulic system for controlling the height of the rail vehicle car described above uses a controller 2 to control the oil inlet pipe 4 to guide hydraulic oil to the hydraulic cylinder 1, causing the hydraulic cylinder 1 to extend and lift the car. The controller 2 also controls the oil outlet pipe 6 to open, causing the hydraulic cylinder 1 to compress under the weight of the car and discharge the oil through the oil outlet pipe 6, thus lowering the car. Controlling the oil inlet speed and volume of the oil inlet pipe 4 adjusts the lifting speed and amount of the car, while controlling the oil outlet speed and volume of the oil outlet pipe 6 adjusts the lowering speed and amount of the car. The oil inlet pipe 4 and oil outlet pipe 6 are separately configured and independently controlled, simplifying the hydraulic circuit structure and facilitating maintenance and testing. The hydraulic cylinder 1 is a single-acting cylinder, providing more precise extension and retraction control. Its internal sealing structure and oil inlet / outlet connection structure are simpler. By combining the car height adjustment requirements with the real-time car height at the hydraulic cylinder connection position, precise control of the car height is achieved, improving the accuracy of car height control, the convenience of hydraulic system maintenance, and the practicality of actual application.

[0027] The hydraulic cylinder 1 includes a cylinder 7 with its opening facing downwards, an integral piston rod 8 that is sealed and guided to the inner wall of the cylinder 7, and a guide seat 9 that is sealed and fixed to the opening end of the cylinder 7 and guided to the integral piston rod 8. The guide seat 9 is fixedly connected to the car floor 100. The lower end of the integral piston rod 8 extends out of the cylinder 7 and is hinged to the bogie support plate 101. The integral piston rod 8 divides the inner cavity of the cylinder 7 into a rodless chamber I and a rod chamber II. The oil inlet pipe 4 is connected to the oil inlet of the rodless chamber I, and the oil outlet pipe is connected to the oil outlet of the rodless chamber I. The cylinder 7 rises as oil enters the rodless chamber I and falls as oil exits the rodless chamber I. As shown in the figure, the upper end of the integrated piston rod 8 is sealed and guided to the inner wall of the cylinder 7, dividing the inner cavity of the cylinder 7 into a rod chamber II and a rodless chamber I. The rodless chamber I is located above the rod chamber II. When oil enters the rodless chamber I, the cylinder 7 will move upward, causing the car body to rise. When oil is discharged from the rodless chamber I, the cylinder 7 will move downward, causing the car body to fall. The lower end of the integrated piston rod 8 is hinged to the bogie support plate 101, so that the hydraulic cylinder 1 can swing relative to the bogie as the car body rises and falls. This prevents the setting of the hydraulic cylinder 1 from interfering with the movement of the car body relative to the bogie, avoids the impact of the hydraulic cylinder 1 on the vibration reduction of the car body, and ensures the smoothness of the car body height adjustment.

[0028] The cylinder 7 has an oil inlet at the top, and the oil inlet pipeline 4 includes an oil pump 41 controlled by the controller 2, an oil inlet proportional solenoid valve 42 controlled by the controller 2, and an oil inlet connector 43 mounted on the oil inlet. The oil tank 5, oil pump 41, oil inlet proportional solenoid valve 42 and oil inlet connector 43 are connected in sequence through oil pipes. Both the oil inlet pipe 4 and the oil outlet pipe 6 are set to a normally closed state without conduction. When the controller controls the oil inlet pipe 4 to open, the oil pump 41 starts and the oil inlet proportional solenoid valve 42 is energized and conducts, pumping the oil in the oil tank 5 into the oil pipe. The oil enters the rodless chamber I through the oil inlet proportional solenoid valve 42 and the oil inlet connector 43. The sealed rodless chamber I lifts the cylinder 7 as the oil enters, so as to lift the car body synchronously. The oil pump ensures that the oil can continuously and stably enter the rodless chamber I during the lifting process. By controlling the opening of the oil inlet proportional solenoid valve 42, the flow rate and velocity of the oil are controlled, thereby accurately controlling the lifting speed and lifting amount of the cylinder 7 and the car body.

[0029] The integrated piston rod 8 has an oil discharge channel 80 along its central axis that connects to the rodless chamber I. The lower end of the oil discharge channel 80 connects to the oil discharge port on the integrated piston rod 8. The oil discharge pipeline 6 includes an oil discharge proportional solenoid valve 61 controlled by the controller 2 and an oil discharge connector 62 mounted on the oil discharge port. The oil tank 5, the oil discharge proportional solenoid valve 61, and the oil discharge connector 62 are connected in sequence via oil pipes. When the oil inlet pipeline 4 is closed and the oil discharge pipeline 6 is opened, the oil discharge proportional solenoid valve 61 is energized and conducts. The carriage descends under gravity, compressing the hydraulic cylinder 1, causing the oil in the rodless chamber I to be squeezed out and discharged back to the oil tank 5 through the oil discharge channel 80 and the oil discharge pipeline 6. By controlling the opening degree of the oil discharge proportional solenoid valve 61, the flow rate and velocity of the discharged oil are controlled, thereby precisely controlling the descent speed and descent amount of the cylinder 7 and the carriage. The oil inlet line 4 and the oil outlet line 6 are set up separately and controlled independently. Both lines use proportional solenoid valves to regulate the flow rate and velocity. The oil circuit structure is simpler, maintenance and repair are more convenient, and troubleshooting is easier. There are no valve systems on the car floor and bogies, which makes it easy to disassemble and replace, and it is highly practical.

[0030] The guide seat 9 has a chamfered edge 91 at the top outer edge, and an oil-gathering ring groove 10 is formed between the inner wall of the cylinder 7 and the chamfered edge 91. An oil return channel 92 connected to the oil-gathering ring groove 10 is opened on the guide seat 9. An oil return connector 93 is assembled at the outer end of the oil return channel 92. The oil return connector 93 is connected to the oil tank 5 through an oil pipe. The upper end of the integrated piston rod 8 is sealed to the inner wall of the cylinder 7. After long-term use, the sealing performance deteriorates due to the frequent reciprocating motion of the integrated piston rod 8, and a slight leakage will form between the integrated piston rod 8 and the inner wall of the cylinder 7. The oil will leak from the rodless chamber I to the rod chamber II. The guide seat 9 and the cylinder 7 are sealed and fixed. When the oil leaks downward from the rodless chamber along the inner wall of the cylinder, it will not flow out between the guide seat 9 and the cylinder 7. As shown in the figure, an oil-collecting ring groove 10 is set at the bottom of the rod chamber II, and an oil return channel 92 is opened on the guide seat 9. The oil leaking from the rodless chamber I to the rod chamber II will accumulate in the oil-collecting ring groove 10 and flow back to the oil tank 5 through the oil return channel 92. This can prevent the leaked oil from flowing out of the rod chamber II and causing corrosion damage to the wiring of the hydraulic system, and can also discharge the leaked oil back to the oil tank, reducing oil waste, lowering the failure rate of the hydraulic system, and improving the practicality of the hydraulic system.

[0031] The integrated piston rod 8 has a bearing hole 81 at its lower end, into which a universal joint bearing 11 is press-fitted. A connecting shaft 12 is assembled in the universal joint bearing 11 and fixedly connected to the bogie support plate 101. The universal joint bearing 11 forms a hinge between the integrated piston rod 8 and the bogie support plate 101, allowing the hydraulic cylinder 1 to swing adaptively when the car body rises or falls relative to the bogie in any direction. This ensures smooth height adjustment of the car body at any position without affecting vibration damping.

[0032] The universal joint bearing 11 has a dustproof sealing ring 13 at both ends of its outer ring and a dustproof sealing ring 14 at both ends of its inner ring to seal the bearing hole. The bearing hole 81 has a retaining ring groove on both sides of the dustproof sealing ring 14. A retaining ring 15 is installed in the retaining ring groove. A washer 16 is placed on the outer end of the dustproof sealing ring 14. The washer 16 and the dustproof sealing ring 14 are axially positioned between the two retaining rings 15. Dustproof sealing ring 13 forms an inner seal between the inner and outer ring end faces of the universal joint bearing 11, and dustproof sealing ring 14 forms an outer seal between the inner and outer ring end faces of the universal joint bearing 11. The double seal prevents sand and dust from entering the universal joint bearing 11, ensuring that the universal joint bearing 11 is not affected by the external environment, avoiding jamming of the universal joint bearing 11 due to sand and dust, improving the reliability of the connection between the hydraulic cylinder 1 and the bogie, ensuring that the hydraulic cylinder 1 will swing with the movement of the carriage during long-term use, improving the adaptability of the hydraulic system to the working environment, improving the reliability of the hydraulic cylinder connection structure, and ensuring the smoothness of the carriage height adjustment control.

[0033] The height monitoring component 3 includes a height sensor 31 mounted on the car floor 100 and connected to the controller 2, and a height adjustment rod 32 whose upper end is hinged to the rotating handle 311 of the height sensor 31. The lower end of the height adjustment rod 32 is hinged to the bogie support plate 101 through a universal joint. The rotating handle 311 of the height sensor 31 rotates as the car rises and falls. When the car body is at a preset height, the rotating handle 11 remains horizontal. When the car body rises or falls beyond the preset value, the rotating handle 11 swings. The height sensor 31 converts the swing angle of the rotating handle 311 into a monitoring signal and transmits it to the controller 2. The controller 2 calculates and analyzes the received monitoring signal to obtain a control signal, which is then sent to the oil inlet pipe 4 or the oil outlet pipe 6 to control the flow of the oil inlet pipe 4 or the oil outlet pipe 6, thereby extending or compressing the hydraulic cylinder 1 and controlling the rise and fall of the car body to adjust the car body height to the preset height. The height sensor 31 with a rotating handle is used to monitor the real-time height change of the car body floor 100. The swing angle of the rotating handle 311 caused by the rise and fall of the car body is used as the monitoring object to form a monitoring signal. The rise and fall of the car body relative to any angle of the bogie can be monitored. The height monitoring has high adaptability, improves the effectiveness and accuracy of monitoring, reduces the adjustment error caused by monitoring error, and thus improves the accuracy of car body height control.

[0034] This invention also protects a method for controlling the height of a rail vehicle car, which uses the above-described hydraulic system for controlling the height of the rail vehicle car to control the height of the car. In the non-adjustment state, the oil inlet pipe 4 and the oil outlet pipe 6 are normally closed, and the height of the car is locked. Raising the height of the carriage: Controller 2 controls the oil inlet pipe 4 to open, so that the oil in the oil tank 5 is introduced into the hydraulic cylinder 1 through the oil inlet pipe 4. The hydraulic cylinder 1 extends as the oil enters, driving the carriage to rise. When the height monitoring component 3 detects that the height of the carriage has risen to the preset height value, controller 2 controls the oil inlet pipe 4 to disconnect, locking the height of the carriage. Lowering the car body height: Controller 2 controls the oil drain line 6 to open. Under the action of the car body's gravity, the oil in the hydraulic cylinder 1 flows through the oil drain line 6 to the oil tank 5, causing the hydraulic cylinder 1 to compress. The car body descends as the hydraulic cylinder 1 is compressed. When the height monitoring component 3 detects that the car body height has dropped to the preset height, controller 2 controls the oil drain line 6 to disconnect, locking the car body height.

[0035] The control method described above, in the non-adjustment state, both the oil inlet pipe 4 and the oil outlet pipe 6 are closed, and the height of the carriage is locked to prevent the height of the carriage from fluctuating arbitrarily. In the adjustment state, when the carriage needs to rise, the controller 2 controls the oil inlet pipe 4 to open and guide the hydraulic oil to the hydraulic cylinder 1, causing the hydraulic cylinder 1 to extend and drive the carriage to rise. When the carriage needs to descend, the controller 2 controls the oil outlet pipe 6 to open, and the hydraulic cylinder 1, under the action of the carriage's gravity, compresses and discharges the oil through the oil outlet pipe 6, driving the carriage to descend. Controlling the oil inlet speed and oil volume of the oil inlet pipe 4 adjusts the lifting speed and lifting amount of the carriage, and controlling the oil outlet speed and oil volume of the oil outlet pipe 6 adjusts the descent speed and descent amount of the carriage. Combining the height adjustment requirements of the carriage and the real-time height of the carriage at the hydraulic cylinder connection position, precise control of the carriage height is achieved, improving the accuracy of the carriage height control.

[0036] Specifically, "Controller 2 controls the oil inlet pipe 4 to be open" means that Controller 2 controls the oil pump 41 to start and controls the proportional oil inlet solenoid valve 42 to be energized and open; "Controller 2 controls the oil inlet pipe 6 to be closed" means that Controller 2 controls the oil pump 41 to be shut down and controls the proportional oil inlet solenoid valve 41 to be de-energized and close; "Controller 2 controls the oil outlet pipe 6 to be open" means that Controller 2 controls the proportional oil outlet solenoid valve 61 to be energized and open; "Controller 2 controls the oil outlet pipe 6 to be closed" means that Controller 2 controls the proportional oil outlet solenoid valve 61 to be de-energized and close. The opening and closing of the oil inlet pipe 4 only requires controlling the oil pump 41 and the proportional oil inlet solenoid valve 42, and the opening and closing of the oil outlet pipe 6 only requires controlling the proportional oil outlet solenoid valve 61. The oil inlet pipe 4 and the oil outlet pipe 6 are set up separately and controlled independently, resulting in high control reliability.

[0037] The technical solutions of the embodiments of the present invention have been fully described above with reference to the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of the present invention. 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.

Claims

1. A hydraulic system for controlling the height of a rail vehicle car, comprising a hydraulic cylinder connected between the car floor and the bogie, a controller for controlling the extension and retraction of the hydraulic cylinder, and a height monitoring component for detecting changes in the car height, characterized in that: The hydraulic cylinder is a single-acting cylinder. The oil inlet of the hydraulic cylinder is connected to the oil tank through the oil inlet pipe, and the oil outlet is connected to the oil tank through the oil outlet pipe. The oil inlet pipe, the oil outlet pipe, and the height monitoring component are controlled by the controller. The hydraulic cylinder extends as oil enters through the oil inlet pipe, causing the truck bed to rise. It compresses as oil exits through the oil outlet pipe, causing the truck bed to descend as the hydraulic cylinder compresses. The hydraulic cylinder includes a cylinder barrel with its opening facing downwards, an integral piston rod that is sealed and guided to the inner wall of the cylinder barrel, and a guide seat that is sealed and fixed to the opening end of the cylinder barrel and guided to the integral piston rod. The guide seat is fixed to the floor of the carriage. The lower end of the integral piston rod extends out of the cylinder barrel and is hinged to the bogie support plate. The integral piston rod divides the inner cavity of the cylinder barrel into a rodless chamber and a rod chamber. The oil inlet pipe is connected to the oil inlet of the rodless chamber, and the oil outlet pipe is connected to the oil outlet of the rodless chamber. The cylinder barrel rises as oil enters the rodless chamber and falls as oil exits the rodless chamber. The cylinder has an oil inlet at the top, and the oil inlet pipeline includes an oil pump controlled by a controller, an oil inlet proportional solenoid valve controlled by a controller, and an oil inlet connector mounted on the oil inlet. The oil tank, oil pump, oil inlet proportional solenoid valve and oil inlet connector are connected in sequence through oil pipes. An oil discharge channel connected to the rodless chamber is opened along the central axis on the integrated piston rod. The lower end of the oil discharge channel is connected to the oil discharge port opened on the integrated piston rod. The oil discharge pipeline includes an oil discharge proportional solenoid valve controlled by the controller and an oil discharge connector assembled on the oil discharge port. The oil tank, the oil discharge proportional solenoid valve and the oil discharge connector are connected in sequence through oil pipes. The outer edge of the top of the guide seat is chamfered, and an oil-gathering ring groove is formed between the inner wall of the cylinder and the chamfered edge. An oil return channel is opened on the guide seat and connected to the oil-gathering ring groove. An oil return connector is installed at the outer end of the oil return channel and is connected to the oil tank through an oil pipe.

2. The hydraulic system for controlling the height of a rail vehicle car according to claim 1, characterized in that: The lower end of the integrated piston rod has a bearing hole, a universal joint bearing is press-fitted into the bearing hole, a connecting shaft is assembled into the universal joint bearing, and the connecting shaft is fixedly connected to the bogie support plate.

3. The hydraulic system for controlling the height of a rail vehicle car according to claim 2, characterized in that: The outer ring of the universal joint bearing is fitted with a dustproof sealing ring 1 at both ends, and the inner ring is fitted with a dustproof sealing ring 2 at both ends to seal the bearing hole. The inner wall of the bearing hole is provided with retaining ring grooves on both sides of the dustproof sealing ring 2. The retaining ring grooves are filled with retaining rings for the hole. The outer end of the dustproof sealing ring 2 is padded with a washer. The washer and the dustproof sealing ring 2 are axially positioned between the two retaining rings for the hole.

4. The hydraulic system for controlling the height of a rail vehicle car according to claim 1, characterized in that: The height monitoring component includes a height sensor mounted on the car floor and connected to the controller signal, a height adjustment rod with its upper end hinged to the rotating handle of the height sensor, and the lower end of the height adjustment rod hinged to the bogie support plate via a universal joint. The rotating handle of the height sensor rotates as the car rises and falls.

5. A method for controlling the height of a rail vehicle car, wherein the rail vehicle car height control hydraulic system as described in any one of claims 1 to 4 is used to control the height of the car, and the oil inlet pipe and oil outlet pipe are normally closed in the non-adjustment state, and the height of the car is locked; Raising the car body height: The controller controls the oil inlet pipe to open, allowing oil from the tank to be introduced into the hydraulic cylinder via the oil inlet pipe. The hydraulic cylinder extends as oil enters, lifting the car body. When the height monitoring component detects... When the height of the carriage reaches the preset height value, the controller disconnects the oil inlet line to lock the height of the carriage. Lowering the car body height: The controller controls the oil drain line to open. Under the action of the car body's gravity, the oil in the hydraulic cylinder flows through the oil drain line to the oil tank, causing the hydraulic cylinder to compress. The car body descends as the hydraulic cylinder compresses. When the height monitoring component detects that the car body height has dropped to the preset height, the controller controls the oil drain line to disconnect, locking the car body height.

6. The method for controlling the height of a rail vehicle car according to claim 5, characterized in that: "Controller controls the oil inlet line to open" means the controller controls the oil pump to start and energizes the oil inlet proportional solenoid valve to open; "Controller controls the oil inlet line to close" means the controller controls the oil pump to close and de-energizes the oil inlet proportional solenoid valve to close; "Controller controls the oil outlet line to open" means the controller controls the oil outlet proportional solenoid valve to open; "Controller controls the oil outlet line to close" means the controller controls the oil outlet proportional solenoid valve to close.

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