The invention relates to a height control mechanism for a rail vehicle comprising suspension units that are arranged between the body and the bogie of the rail vehicle and that each comprise a spring, a pneumatic or a hydraulic reciprocating piston element. In accordance with the invention, the reciprocating piston element is retracted so much in train operation that it does not bridge the spacing between the body and the bogie.

The invention relates to a height control mechanism for a rail vehicle comprising suspension units that are arranged between the body and the bogie of the rail vehicle and that each comprise a spring, a pneumatic or a hydraulic reciprocating piston element. In accordance with the invention, the reciprocating piston element is retracted so much in train operation that it does not bridge the spacing between the body and the bogie.

An air spring includes: an upper surface plate; a lower surface plate opposing the upper surface plate; an elastic film airtightly coupling a peripheral portion of the upper surface plate and a peripheral portion of the lower surface plate to each other to form an air chamber inside the air spring; the air chamber connected to the lower surface plate; and an exhaust passage forming body at which an exhaust passage is formed. The exhaust passage includes an exhaust passage inlet and an exhaust passage outlet. The exhaust passage inlet is open to an outside of the air chamber when a clearance between the upper surface plate and the lower surface plate in an upward/downward direction falls within a predetermined allowable range and is open to an inside of the air chamber when the clearance exceeds an upper limit of the predetermined allowable range.

An air spring includes: an upper surface plate; a lower surface plate opposing the upper surface plate; an elastic film airtightly coupling a peripheral portion of the upper surface plate and a peripheral portion of the lower surface plate to each other to form an air chamber inside the air spring; the air chamber connected to the lower surface plate; and an exhaust passage forming body at which an exhaust passage is formed. The exhaust passage includes an exhaust passage inlet and an exhaust passage outlet. The exhaust passage inlet is open to an outside of the air chamber when a clearance between the upper surface plate and the lower surface plate in an upward/downward direction falls within a predetermined allowable range and is open to an inside of the air chamber when the clearance exceeds an upper limit of the predetermined allowable range.

A main tank storing pressurized air supplied to a pair of air springs; an air supply passage through which the pressurized air flows between the main tank and each of the pair of air springs; a plurality of compressors configured to supply the pressurized air to the main tank; an air discharge passage which is connected to the pair of air springs and through which discharged pressurized air discharged from the air springs flows; and an exhaust tank connected to the air discharge passage and storing the discharged pressurized air discharged from the air springs, the plurality of compressors including at least one first compressor configured to pressurize air introduced from an atmosphere and at least one second compressor configured to operate auxiliarily for an operation of the first compressor and pressurize the discharged pressurized air introduced from the exhaust tank.

A secondary suspension system for a railcar comprises a chassis, a primary spring, a levelling actuator, a first hydraulic circuit and a secondary spring. The levelling actuator is adapted to be connected to the carbody. A piston shoulder, located at the lower portion of the piston and below an opening in the chassis, reaches farther than the opening so as to be capable of catching the chassis. The secondary spring is at least partially positioned underneath the piston shoulder. The piston is operative to adopt a high position inside the body under a pressure of a hydraulic fluid injected in a lower chamber below a piston head. This makes the piston shoulder abut against the chassis, thereby compressing the primary spring between the body and the chassis without compressing the secondary suspension.

A leveling valve includes an actuator arm that rotates due to a restoring force of a buffer spring, and a connecting valve that is opened by the actuator arm against air pressure. The connecting valve includes a first valve body that is opened by being pressed by the actuator arm, a second valve body from/on which the first valve body is separated/seated, a sleeve from/on which the second valve body is separated/seated, and an engaging portion that is provided to the second valve body and engages with the first valve body when the first valve body has moved by a predetermined distance after the first valve body is opened. A pressure receiving area of the second valve body is larger than a pressure receiving area of the first valve body.

A leveling valve includes an actuator arm that rotates due to a restoring force of a buffer spring, and a connecting valve that is opened by the actuator arm against air pressure. The connecting valve includes a first valve body that is opened by being pressed by the actuator arm, a second valve body from/on which the first valve body is separated/seated, a sleeve from/on which the second valve body is separated/seated, and an engaging portion that is provided to the second valve body and engages with the first valve body when the first valve body has moved by a predetermined distance after the first valve body is opened. A pressure receiving area of the second valve body is larger than a pressure receiving area of the first valve body.

A method for controlling a position of a floor of a carriage of a railway vehicle moving on rails, relative to a platform. The carriage includes a body including the floor, at least one bogie, and at least one suspension interposed between the body and the bogie. The method includes determining a level difference between the actual position of the carriage relative to the platform and an expected position of the carriage relative to the platform, adjusting a height of the suspension for compensating the determined level difference. Determining the level difference includes capturing an image of at least one predetermined pattern comprised on the platform with a camera borne by the body, comparing the captured image with a memorized reference image of the at least one pattern of the platform, and calculating a vertical displacement from the images to determine the level difference.

A method for controlling a position of a floor of a carriage of a railway vehicle moving on rails, relative to a platform. The carriage includes a body including the floor, at least one bogie, and at least one suspension interposed between the body and the bogie. The method includes determining a level difference between the actual position of the carriage relative to the platform and an expected position of the carriage relative to the platform, adjusting a height of the suspension for compensating the determined level difference. Determining the level difference includes capturing an image of at least one predetermined pattern comprised on the platform with a camera borne by the body, comparing the captured image with a memorized reference image of the at least one pattern of the platform, and calculating a vertical displacement from the images to determine the level difference.