Buffer cylinder for anti-bending system of low-floor tram

Abstract

The present invention provides a buffer cylinder for a low-floor tram anti-bending system. A two-way piston rod and piston rod guiding and supporting seats located at both ends of the piston rod are arranged inside the cylinder body. Spring outer guiding sleeves are arranged at both ends of the cylinder body. A spring pressing seat and a spring supporting seat which are coaxial are sequentially arranged inside the spring outer guiding sleeves along the direction away from the piston rod guiding and supporting seats. A disc spring is arranged between the spring pressing seat and the spring supporting seat. The sliding end of the two-way piston rod passes through the piston rod guiding and supporting seat and is connected to the spring pressing seat. Oil ports corresponding to and communicating with the internal oil cavities are arranged on the cylinder body, and the two are respectively connected to the incoming oil circuit and the outgoing oil circuit between the front and rear bogies. A two-way sealing packing ring is arranged on the two-way piston rod. Multistage sealing is adopted between the piston rod guiding and supporting seat, the cylinder body and the two-way piston rod. The buffer cylinder is also provided with an internal transition oil sump and an external oil storage tank. The present invention reduces the pressure peak during the operation of the system, reduces the vibration impact brought by the vehicle body, and improves the riding comfort.

Description

Technical Field

[0001] The present invention relates to the technical field of rail vehicles, and in particular, to a buffer cylinder structure for an anti-bending system of a low-floor tramcar. Background Art

[0002] The floor of a low-floor tramcar is only 35 cm from the rail surface, without the need for platform facilities. The maximum passenger capacity is 6 to 8 times that of a bus. The vehicle uses a parallel hybrid power of a battery and a super capacitor to provide a catenary-free solution for the whole line, has a strong climbing ability, and the minimum turning radius is only 19 m. Compared with ordinary catenary trams, low-floor trams have obvious advantages such as less development investment, shorter development time, not being restricted by the power grid, wide applicable regions, convenient for passengers to get on and off, saving operation costs and energy, and are the most "green" means of transportation at present.

[0003] In the normal operation mode of a rail vehicle, the running mechanism that rotates by means of a torsion spring on a curve generates a reset moment. Through the action of the reset moment, the front and rear car bodies connected by a connecting rod are linked, which will cause the connecting rod to rotate and increase the lateral force borne by the wheel flange. Once this rotation and lateral force exceed the vehicle gauge, it will cause relative bending between the front and rear car bodies, damage the bogie for carrying the car body, and affect the driving safety.

[0004] Therefore, we have developed an anti-bending system, the purpose of which is to achieve a smooth transition of the actions between the front and rear car bodies by delaying the transfer of the rapid displacement from the previous bogie to the next bogie. Therefore, the buffer cylinder is the most important component in the whole anti-bending system. It is necessary to ensure that the transfer volume of the hydraulic oil meets the requirements, the flow rate of the hydraulic oil cannot be too fast, and at the same time, the tightness and safety of the oil circuit must be ensured. This poses relatively high requirements on the structure of the buffer cylinder.

[0005] At present, there is no buffer cylinder product specifically designed for use in the anti-bending system in the industry. Summary of the Invention

[0006] The purpose of the present invention is to provide a hydraulic oil buffer cylinder with good stiffness adjustability, reliable tightness, and long service life to solve the problems in the background art.

[0007] To achieve the above purpose, the present invention provides a buffer cylinder for an anti-bending system of a low-floor tramcar, including a cylinder body, a bidirectional piston rod, a piston rod guide support, a disc spring, a spring outer guide sleeve, a spring pressing seat, and a spring support seat.

[0008] The cylinder block is of a cylindrical structure with openings at both ends in the length direction. The double-acting piston rod is arranged inside the cylinder block and can slide along its length direction. The piston rod guiding and supporting seat is arranged at both ends in the sliding direction of the double-acting piston rod and is fixedly connected to the inner wall of the cylinder block. The spring outer guiding sleeve is arranged at both openings of the cylinder block, and after being fixedly connected with the cylinder block, it cooperates with the piston rod guiding and supporting seat to form a cavity for accommodating the disc spring, spring pressing seat and spring supporting seat. The spring pressing seat and spring supporting seat are arranged in sequence along the direction away from the piston rod guiding and supporting seat, and the three are coaxially arranged. The spring pressing seat is slidably arranged. The disc spring is arranged in the same direction as the sliding direction of the double-acting piston rod, and its two ends are respectively connected to the opposite ends of the spring supporting seat and the spring pressing seat. The other end of the spring pressing seat is connected to the part of the double-acting piston rod that passes through the piston rod guiding and supporting seat.

[0009] The internal space of the cylinder block is divided into two oil cavities by the double-acting piston rod. The double-acting piston rod reciprocates under the action of the disc springs and spring pressing seats at both ends to adjust the volume of the two oil cavities. Oil ports are arranged on the cylinder block corresponding to each oil cavity. One oil port is connected to the incoming oil circuit between the front and rear bogies, and the other oil port is connected to the outgoing oil circuit between the front and rear bogies.

[0010] Preferably, a Gleitring is provided at the position where the piston on the double-acting piston rod contacts the inner wall of the cylinder block. The Gleitring is made of polytetrafluoroethylene with an O-ring as the force-applying element to achieve double-sided sealing between the two oil cavities.

[0011] Preferably, the piston rod guiding and supporting seat is fixedly installed inside the cylinder block through a shaft retaining ring, flat washer and hole retaining ring. Two O-ring seals are provided between the piston rod guiding and supporting seat and the inner wall of the cylinder block to achieve static sealing.

[0012] Preferably, a high-pressure seal and a low-pressure seal are provided between the piston rod guiding and supporting seat and the double-acting piston rod to achieve two-stage dynamic sealing of high and low pressures. Grooves for installing the high-pressure seal, as well as round grooves and threads for installing the low-pressure seal, are machined on the surface of the piston rod guiding and supporting seat.

[0013] Preferably, the high-pressure seal is a Strseal made of T46T material with an O-ring as the force-applying element, and the low-pressure seal is a lip-type rubber seal with a spring as elastic compensation and a skeleton.

[0014] Preferably, an annular transition oil storage groove is provided between the groove and the round groove of the piston rod guiding and supporting seat.

[0015] Preferably, an annular oil storage groove is provided on the outer wall of the cylinder block. An oil storage cover is provided on the oil storage groove, and the oil storage groove is sealed by fixedly connecting the oil storage cover to the outer wall of the cylinder block. The oil storage groove is communicated with the transition oil storage groove through an oil guiding hole.

[0016] Preferably, exhaust ports are provided corresponding to each oil chamber at the top of the cylinder block, exhaust screws are provided at the exhaust ports, a pressure breather valve is provided at the top of the oil storage tank, an oil drain port is provided at the bottom of the oil storage tank, and an oil drain screw is provided at the oil drain port.

[0017] Preferably, guide grooves are machined at both sliding ends of the double-acting piston rod, and guide members matching the guide grooves are machined on the piston rod guide support seat; coaxial vent holes are provided inside the double-acting piston rod and the spring pressing seat, so that the gas at both ends of the buffer cylinder can flow through to maintain air pressure balance.

[0018] Preferably, the spring outer guide sleeve is connected to the cylinder block by threads.

[0019] The technical solution provided by the present invention has at least the following beneficial effects:

[0020] By using the buffer cylinder provided by the present invention, a part of the high-flow and high-pressure hydraulic oil from the front bogie control cylinder can be diverted into an oil chamber (high-pressure chamber) of the buffer cylinder, reducing the pressure peak of the high-pressure oil circuit. When the oil circuit in the high-pressure chamber slowly enters the control cylinder of the rear bogie through the throttle valve, the pressure slowly decreases. The buffer cylinder slowly discharges the oil in the high-pressure chamber to the equilibrium position through the restoring force of the compressed spring, so that the volume of this oil circuit returns to the equilibrium position, thereby realizing the delay transfer of the rapid displacement of the previous bogie to the next bogie, reducing the system working pressure peak, reducing the vibration impact of the low-floor tram, and improving the riding comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings, where:

[0022] Figure 1 is a schematic structural diagram of the buffer cylinder for the anti-bending system of the low-floor tram in Embodiment 1 of the present invention;

[0023] Figure 2 is Figure 1 an enlarged structural view of the cylinder block part in

[0024] Wherein: 1 cylinder block, 2 double-acting piston rod, 3 piston rod guide support seat, 4 disc spring, 5 spring outer guide sleeve, 6 spring pressure seat, 7 spring support seat, 8 Gleason ring, 9 high-pressure seal, 10 low-pressure seal, 11 transition oil sump, 12 oil storage tank, 13 oil storage cover, 14 exhaust screw, 15 pressure breather valve, 16 oil drain screw, 17 first oil port, 18 second oil port. Detailed implementation mode

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] Embodiment 1

[0027] See Figure 1 And Figure 2 , a buffer cylinder for a low-floor tram anti-bending system, including a cylinder block 1, a double-acting piston rod 2, a piston rod guide support seat 3, a disc spring 4, a spring outer guide sleeve 5, a spring pressure seat 6 and a spring support seat 7.

[0028] The cylinder block 1 is of a cylindrical structure with openings at both ends in the length direction. The double-acting piston rod 2 is arranged in the cylinder block 1 and can slide along its length direction. The piston rod guide support seat 3 is arranged at both ends of the sliding direction of the double-acting piston rod 2 and is fixedly connected to the inner wall of the cylinder block 1. The spring outer guide sleeve 5 is arranged at both open ends of the cylinder block 1, and after being fixedly connected with the cylinder block 1, it cooperates with the piston rod guide support seat 3 to form a cavity for accommodating the disc spring 4, the spring pressure seat 6 and the spring support seat 7. The spring pressure seat 6 and the spring support seat 7 are arranged in sequence along the direction away from the piston rod guide support seat 3 and are coaxially arranged. The spring pressure seat 6 is slidably arranged. The disc spring 4 is arranged in the same direction as the sliding direction of the double-acting piston rod 2, and both ends are respectively connected to the opposite ends of the spring support seat 7 and the spring pressure seat 6. The other end of the spring pressure seat 6 is connected to the part of the double-acting piston rod 2 that passes through the piston rod guide support seat 3.

[0029] The internal space of the cylinder block 1 is divided into two oil chambers by the double-acting piston rod 2. The double-acting piston rod 2 reciprocates under the action of the disc springs 4 and the spring pressure seat 6 at both ends to adjust the volume of the two oil chambers. Oil ports are provided on the cylinder block 1 corresponding to each oil chamber, namely the first oil port 17 and the second oil port 18. Among them, the first oil port 17 is connected to the incoming oil circuit between the front and rear bogies, and the second oil port 18 is connected to the outgoing oil circuit between the front and rear bogies.

[0030] At the position where the piston on the double-acting piston rod 1 contacts the inner wall of the cylinder block 1, a Gleitring 8 is provided. The Gleitring 8 is made of polytetrafluoroethylene with an O-ring rubber as the force-applying element to achieve double-directional sealing between the two oil cavities, ensuring no internal leakage between the two oil cavities during the operation of the piston rod.

[0031] The piston rod guide support seat 3 is fixedly installed inside the cylinder block 1 through a shaft retaining ring, flat washer, and hole retaining ring, facilitating the assembly and maintenance of the buffer cylinder. Between the piston rod guide support seat 3 and the inner wall of the cylinder block 1, two O-ring seals are provided to achieve static sealing, ensuring no external leakage between the piston rod guide support seat and the cylinder block.

[0032] Between the piston rod guide support seat 3 and the double-acting piston rod 2, a high-pressure seal 9 and a low-pressure seal 10 are provided to achieve two-stage dynamic sealing of high and low pressures. On the surface of the piston rod guide support seat 3, a groove for installing the high-pressure seal 9, a circular groove, and a thread for installing the low-pressure seal 10 are machined. The low-pressure seal 10 is pressed and installed in the circular groove through a gland.

[0033] In this embodiment, the high-pressure seal is a Struthers seal made of T46T material with an O-ring as the force-applying element, and the low-pressure seal 10 is a lip-type rubber seal with a skeleton and a spring as the elastic compensation, double ensuring the sealing reliability.

[0034] An annular transition oil storage groove 11 is provided between the groove and the circular groove of the piston rod guide support seat 3. An annular oil storage groove 12 is provided on the outer wall of the cylinder block 1. An oil storage cover 13 is provided on the oil storage groove 12, and the oil storage groove 12 is sealed by fixedly connecting the oil storage cover 13 to the outer wall of the cylinder block. The oil storage groove 12 is communicated with the transition oil storage groove 11 through oil guiding holes provided inside the piston rod guide support seat 3 and in the side wall of the cylinder block 1.

[0035] A small amount of high-pressure oil first flows into the transition oil storage groove 11 after leakage from the high-pressure seal, and then is continuously conducted to the oil storage groove 12 for storage. Through this structural design, it can be avoided that the leaked hydraulic oil accumulates between the high-pressure seal and the low-pressure seal to form high pressure, further causing the sealing failure of the low-pressure seal and resulting in external leakage, ensuring zero external leakage of the buffer cylinder itself.

[0036] At the top of the cylinder block 1, an exhaust port is provided corresponding to each oil cavity, and an exhaust screw 14 is provided at the exhaust port. A pressure breathing valve 15 is provided at the top of the oil storage groove 12 for adjusting the pressure in the oil storage groove 12. An oil drain port is provided at the bottom of the oil storage groove 12, and an oil drain screw 16 is provided at the oil drain port.

[0037] Guide grooves are machined at both sliding ends of the bidirectional piston rod 2, and guide members matching the guide grooves are machined on the piston rod guide support seat 3, which improves the assembly coaxiality of the bidirectional piston rod and the cylinder block and ensures the smooth operation of the buffer cylinder.

[0038] Coaxial vent holes are provided inside the bidirectional piston rod 2 and the spring pressing seat 6, enabling the gas at both ends of the buffer cylinder to flow, and realizing the air pressure balance inside the spring outer guide sleeves on both sides.

[0039] In this embodiment, a cermet ultrafine powder sprayed coating is provided on the surface of the bidirectional piston rod 2 to improve the wear resistance life of the piston rod.

[0040] The spring outer guide sleeve 5 is connected to the cylinder block 1 by threads. The response pressure and stiffness of the buffer cylinder can be adjusted by adjusting the screwing depth of the threads. After adjustment, it can be fixed by the set screw on the spring outer guide sleeve.

[0041] The working principle of the above buffer cylinder is as follows:

[0042] When the low-floor tram turns or vibrates laterally, the large-flow hydraulic oil generated by the rapid compression displacement of the anti-bending system control cylinder of the previous bogie flows through the one-way valve to the anti-bending system control cylinder of the next bogie. Due to the resistance of the throttle valve, an instantaneous high pressure is generated, causing the hydraulic oil to be divided into two paths. Part of it enters the control cylinder of the rear bogie through the damping valve, pushing the control cylinder to stretch, while most of the remaining enters the first oil port of the buffer cylinder, causing the buffer cylinder piston rod to move to the right, increasing the volume of the left oil circuit, reducing the pressure peak, and at the same time compressing the spring on the right side of the buffer cylinder. When the buffer cylinder piston rod reaches pressure balance, it stops moving. As the throttle valve slowly passes oil, the pressure of the hydraulic oil at this place begins to drop, and the oil begins to flow out from the first oil port of the buffer cylinder, and then enters the control cylinder of the rear bogie through the throttle valve, causing the control cylinder to continue to stretch. Finally, the buffer cylinder piston rod returns to the center, realizing that the oil of the rapid displacement generated by the control cylinder of the anti-bending system of the previous bogie flows into the control cylinder of the rearward moving bogie after being buffered by the buffer cylinder, thereby realizing the buffering of the vibration impact of the low-floor tram and improving the ride comfort of the vehicle.

[0043] The above are only the preferred embodiments of the present invention, and do not limit the patent protection scope of the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Within the spirit and principle of the present invention, any improvement or equivalent replacement made by using the content of the specification and drawings of the present invention, directly or indirectly applied to other related technical fields, shall be included in the patent protection scope of the present invention.

Claims

1. A buffer cylinder for a low - floor tram anti - bending system, characterized in that, it includes a cylinder body (1), a two - way piston rod (2), a piston rod guiding and supporting seat (3), a disc spring (4), a spring outer guiding sleeve (5), a spring pressing seat (6) and a spring supporting seat (7); The cylinder body (1) is of a cylindrical structure with both ends open in the length direction. The two - way piston rod (2) is arranged inside the cylinder body (1) and can slide along its length direction. The piston rod guiding and supporting seat (3) is arranged at both ends in the sliding direction of the two - way piston rod (2) and is fixedly connected to the inner wall of the cylinder body (1). The spring outer guiding sleeve (5) is arranged at both open ends of the cylinder body (1), and after being fixedly connected with the cylinder body (1), it cooperates with the piston rod guiding and supporting seat (3) to form a cavity for accommodating the disc spring (4), the spring pressing seat (6) and the spring supporting seat (7). The spring pressing seat (6) and the spring supporting seat (7) are arranged in sequence along the direction away from the piston rod guiding and supporting seat (3) and the three are coaxially arranged. The spring pressing seat (6) is slidably arranged. The disc spring (4) is arranged in the same direction as the sliding direction of the two - way piston rod (2), and both ends are respectively connected to the opposite ends of the spring supporting seat (7) and the spring pressing seat (6). The other end of the spring pressing seat (6) is connected to the part of the two - way piston rod (2) that passes through the piston rod guiding and supporting seat (3); The internal space of the cylinder body (1) is divided into two oil cavities by the two - way piston rod (2). The two - way piston rod (2) reciprocates under the action of the disc springs (4) and the spring pressing seat (6) at both ends to adjust the volume of the two oil cavities. Oil ports are arranged on the cylinder body (1) corresponding to each oil cavity. One oil port is connected to the incoming oil circuit between the front and rear bogies, and the other oil port is connected to the outgoing oil circuit between the front and rear bogies.

2. The buffer cylinder for a low - floor tram anti - bending system according to claim 1, characterized in that, at the position where the piston on the two - way piston rod (2) contacts the inner wall of the cylinder body (1), there is a Gleitring (8). The Gleitring (8) uses polytetrafluoroethylene with an O - ring rubber as the force - applying element to achieve two - way sealing between the two oil cavities.

3. The buffer cylinder for a low - floor tram anti - bending system according to claim 2, characterized in that, The piston rod guiding and supporting seat (3) is fixedly installed inside the cylinder body (1) through a shaft - type wire snap ring, a flat washer and a hole - type wire snap ring. There are two O - ring seals between the piston rod guiding and supporting seat (3) and the inner wall of the cylinder body (1) to achieve static sealing.

4. The buffer cylinder for a low - floor tram anti - bending system according to claim 3, characterized in that, A high - pressure seal (9) and a low - pressure seal (10) are arranged between the piston rod guiding and supporting seat (3) and the two - way piston rod (2) to achieve two - stage dynamic sealing of high and low pressures. Grooves for installing the high - pressure seal (9), circular grooves and threads for installing the low - pressure seal (10) are machined on the surface of the piston rod guiding and supporting seat (3).

5. The buffer cylinder for a low - floor tram anti - bending system according to claim 4, characterized in that, The high-pressure seal (9) is a T46T material Straddle seal with an O-ring as the force-applying element, and the low-pressure seal (10) is a lip-type rubber seal with a spring as an elastic compensation and a skeleton.

6. The buffer cylinder for the anti-bending system of the low-floor tram according to claim 4, characterized in that, an annular transitional oil storage groove (11) is provided between the groove and the circular groove of the piston rod guiding and supporting seat (3).

7. The buffer cylinder for the anti-bending system of the low-floor tram according to claim 6, characterized in that, an annular oil storage groove (12) is provided on the outer wall of the cylinder block (1), and an oil storage cover (13) is provided on the oil storage groove (12). The oil storage groove is sealed by fixedly connecting the oil storage cover (13) to the outer wall of the cylinder block, and the oil storage groove (12) is communicated with the transitional oil storage groove (11) through an oil guiding hole.

8. The buffer cylinder for the anti-bending system of the low-floor tram according to claim 7, characterized in that, an exhaust port is provided corresponding to each oil chamber at the top of the cylinder block (1), an exhaust screw (14) is provided at the exhaust port, a pressure breathing valve (15) is provided at the top of the oil storage groove (12), and an oil drain port is provided at the bottom of the oil storage groove (12), and an oil drain screw (16) is provided at the oil drain port.

9. The buffer cylinder for the anti-bending system of the low-floor tram according to claim 8, characterized in that, guide grooves are machined at both sliding ends of the double-ended piston rod (2), and guiding members matching the guide grooves are machined on the piston rod guiding and supporting seat (3); coaxial ventilation holes are provided inside the double-ended piston rod (2) and the spring pressure seat (6) so that the gases at both ends of the buffer cylinder can flow to maintain air pressure balance.

10. The buffer cylinder for the anti-bending system of the low-floor tram according to claim 9, characterized in that, the spring outer guide sleeve (5) is connected to the cylinder block (1) by threads.

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