| 主权项 |
1. A piston (10) for a damping-adjustable shock absorber, and arranged to be slidably mounted inside a cylinder of the shock absorber to split the shock absorber into a lower chamber and an upper chamber, the piston (10) comprising:
a first pair of passive flow-control valves (18, 20) for controlling flow of a damping fluid between the lower chamber and the upper chamber via a first flow path (42, 40, 44, 72, 74, 68), the first pair of passive flow-control valves (18, 20) including a first compensation valve (18) made as a check valve arranged to control the flow of the damping fluid from the lower chamber to the upper chamber, and a first rebound valve (20) made as a check valve arranged to control the flow of the damping fluid from the upper chamber to the lower chamber wherein the first compensation valve (18) includes a first resilient element (78) adapted to keep the first compensation valve normally closed and the first rebound valve (20) includes a second resilient element (82) adapted to keep the first compensation valve normally closed; a second pair of passive flow-control valves (22, 24) for controlling the flow of the damping fluid between the lower chamber and the upper chamber via a second flow path (118, 110, 112, 120) separate from the first flow path (42, 40, 44, 72, 74, 68), the second pair of passive flow-control valves (22, 24) including a second compensation valve (22) made as a check valve arranged to control the flow of the damping fluid from the lower chamber to the upper chamber, and a second rebound valve (24) made as a check valve arranged to control the flow of the damping fluid from the upper chamber to the lower chamber wherein the second compensation valve (22) includes a third resilient element (136) adapted to keep the second compensation valve normally closed and the second rebound valve (24) includes a fourth resilient element (154) adapted to keep the second compensation valve normally closed; a flow-dividing solenoid valve (14) shiftable between a first operating position that allows the damping fluid to flow between the upper chamber and the lower chamber via the first pair of passive flow-control valves (18, 20) and the second pair of passive flow-control valves (22, 24) and, thus, the first flow path (42, 40, 44, 72, 74, 68) and the second flow path (118, 110, 112, 120) and a second operating position that allows the damping fluid to flow between the upper chamber and the lower chamber via only the second pair of passive flow-control valves (22, 24) and, thus, the second flow path (118, 110, 112, 120) wherein the solenoid valve (14) is normally open such that the solenoid valve (14) is normally held in the first operating position; wherein the piston comprises further a rod (12), a valve assembly (16), and a connecting body (26) substantially axially interposed between and fixed to the rod (12) and the valve assembly (16), the valve assembly (16) and the connecting body (26) defining, between the upper chamber and the lower chamber, the first flow path (42, 40, 44, 72, 74, 68) and the second flow path (118, 110, 112, 120) and the solenoid valve (14) including a solenoid (50) fixed inside the rod (12) and a poppet (46) arranged inside the connecting body (26) to be moved under control of the solenoid (50) between an open position, corresponding to the first operating position of the solenoid valve (14) that opens the first flow path (42, 40, 44, 72, 74, 68), and a closed position, corresponding to the second operating position of the solenoid valve (14) that closes the first flow path (42, 40, 44, 72, 74, 68); wherein the valve assembly (16) includes a hollow inner body (54) defining, along with the connecting body (26), the first flow path (42, 40, 44, 72, 74, 68) and a hollow outer body (56) that is arranged substantially coaxially with the inner body (54) and defines, along with the inner body (54), the second flow path (118, 110, 112, 120), the first pair of passive flow-control valves (18, 20) being located in the inner body (54) and the second pair of passive flow-control valves (22, 24) being located between the inner body (54) and the outer body (56); wherein the valve assembly (16) further includes a first partition plate (70) that is accommodated in a chamber (66) of the inner body (54) to split the chamber (66) into an upper chamber portion and a lower chamber portion and has first and second through-bores (72, 74) adapted to put the chamber portions in fluid communication with each other, the first through-bores (72) being arranged radially outwardly of the second-through bores (74) and the first compensation valve (18) and the first rebound valve (20) being located in the upper chamber portion and the lower chamber portion, respectively; wherein the first partition plate (70) defines, on a side of the lower chamber portion, an auxiliary chamber (98), the first rebound valve (20) includes a movable element (80) on which the second resilient element (82) acts and at least one adjustment disc (84) that is interposed between the movable element (80) and the first partition plate (70) and cooperates with the second through-bores (74), and the first rebound valve (20) is configured to have: a first variable restrictor (96, 84) a restriction amount of which depends on a position of the movable element (80) and through which the upper chamber portion is in fluid communication with the lower chamber portion; a second variable restrictor (94, 84) a restriction amount of which depends on the position of the movable element (80) and through which the upper chamber portion is in fluid communication with the auxiliary chamber (98); and a first fixed restrictor (102) via which the auxiliary chamber (98) is in fluid communication with the lower chamber portion, whereby, as a result of an increase in a distance between the movable element (80) and the first partition plate (70), a pressure value in the auxiliary chamber (98) and an opening force acting on the movable element (80) against a resilient force generated by the second resilient element (82) increase; and wherein the first partition plate (70) forms, on a side facing toward the lower chamber portion, a first annular projection (94) and a second annular projection (96) that radially limit the second through-bores (74), the auxiliary chamber (98) is formed by an annular cavity of the first partition plate (70) extending radially between a substantially cylindrical guide element (90) substantially coaxial to the piston and the first annular projection (94), the first variable restrictor (96, 94) is formed by a passage between the second annular projection (96) and the at least one adjustment disc (84), the second variable restrictor (94, 84) is formed by a passage between the first annular projection (94) and the at least one adjustment disc (84), and the first fixed restrictor (102) is defined by a difference of radius between an inner edge of the at least one adjustment disc (84) and an outer lateral surface of the cylindrical guide element (90). |
