| 摘要 |
PURPOSE:To control damping force in multistate according to the running conditions by incorporating a solenoid-controlled spool valve for controlling the connection of passages connecting chambers on both sides of a piston in the internal end portion of a piston rod of a hydraulic draft gear. CONSTITUTION:A twin-tube hydraulic draft gear has a piston rod 14 movably inserted in a cylinder, and a piston (not shown) is mounted on the end portion 15 of the rod. In this case, on the internal end portion of the piston rod 14, a hole 24 for a coil and a hole 26 for a spool valve are formed in such a manner as to be connected to each other, and the first and second passages 34, 36 are formed as a by-path. A core 40 having coils 50, 52 wound round both ends thereof is disposed in the hole 24, and a plunger 44 deviated to a neutral position by springs 66, 68 is fitted in an axial through hole 42 of the core 40. A spool valve 58 in the hole 26 is slid to displace through a connecting rod 60 by controlling the electricity applied to the coils 50, 52. |
