摘要:
A hydraulic force regulating system (10') presenting a hydraulic actuator (11) including a cylinder (15) housing a piston (16) movable in relation to the cylinder; a hydraulic circuit (12-14) in turn presenting a servovalve (12) for controlling supply to the actuator; a first force regulating loop (26-29) which, on the basis of the difference between the actual force (F m ) generated by the piston (16) and the required nominal force (F r ), regulates the current (I) supplied to the servovalve (12); and a second regulating loop (35) which, on the basis of the speed (V) of the piston (16) in relation to the cylinder (15), generates an additional current (I₁) for the servovalve (12), to achieve a substantially elastic performance of the hydraulic system (10'). More specifically, the additional current (I₁) opens the servovalve (12) by the exact amount required to permit the passage, in the presence of a desired pressure difference Δp, of the flow AV (product of piston area A and speed) produced by the movement of the piston (16) in relation to the cylinder (15).
摘要:
A control system wherein an electronic control unit (14) generates a drive signal for a hydraulic device (13l, 13r, 15) for rotating the body (11) of a railroad car (3) about a longitudinal axis (G) of the car to reduce the non-compensated transverse acceleration to which the passengers are subjected. The control system presents a differentiating circuit (37) and a proportional circuit (31), which are supplied with an error signal (ϑe) equal to the difference between a reference signal (ϑc) and a feedback signal (ϑz) indicating the actual tilt angle of the body. The outputs of the differentiating circuit (37) and the proportional circuit (31) are added to generate a drive signal for driving the hydraulic device (13l, 13r, 15); and the differentiating circuit (37) presents a derivative gain (Gd) which is a function of the derivative in time (d|ϑe|/dt) of the error signal (ϑe) modulus.
摘要:
A hydraulic system (1) for controlling rotation of a railroad car body (2), and presenting a motor pump assembly (8) connected to a hydraulic fluid tank (7) and to a supply line (14); a number of hydraulic actuators (3a, 3b, 4a, 4b) for exerting mechanical force on the body (2) to rotate it; a solenoid valve (26) for selectively connecting the hydraulic actuators (3a, 3b, 4a, 4b) to the supply line (14) or to a drain (29) in response to electric control signals; and a bypass start valve (64) for depressurizing the supply line (14) during start-up of the motor pump assembly (8); the bypass start valve (64) being a purely hydraulically operated, normally-open valve, which switches automatically when supply from the motor pump assembly (8) reaches a predetermined threshold value.
摘要:
A hydraulic system (1) for controlling rotation of a railroad car body (2), and presenting a motor pump assembly (8) connected to a hydraulic fluid tank (7) and to a supply line (14); a number of hydraulic actuators (3a, 3b, 4a, 4b) for exerting mechanical force on the body (2) to rotate it; a solenoid valve (26) for selectively connecting the hydraulic actuators (3a, 3b, 4a, 4b) to the supply line (14) and to a drain (29) in response to electric control signals; and a device (61) for depressurizing the actuators (3a, 3b, 4a, 4b) and disabling the system at the end of the duty period or in the event of an emergency. The device (61) presents two hydraulically driven, normally-open disabling valves (47) interposed between respective pairs of actuators (3a, 4a; 3b, 4b) and the drain (29), and presenting respective drive lines (59) connected to the supply line (14); and an electric distributor (46) for depressurizing the drive lines (59).