| 摘要 |
<p>PURPOSE:To make it possible to supply oil pressure under a semi-clutch state in the range of a wide stroke of pedal by installing a spring between an inching spool and a main spool and providing a variable spring which is interlocked with variable speed stages at the other end of the main spool. CONSTITUTION:When an inching valve 61 is continuously stepped down, a main spool 114 will not move, even if a spool 61 is held down, because the force of a spring 115 is weaker than that of a spring 116 until a notched member 61c of the spool 61 is comunicated to a port 61b, and the pressure to a hydraulic clutch unit is not changed. If the notched member 61c is depressed until it is communicated to a throttle port 61b, the pressure oil of a port 114c is partially introduced into a spring chamber 115a of the spring 115 through the throttle port 61, the notched member 61c, and a through oil hole 61, and starts pressing down the spool 114 with both the spring 115 and the oil pressure P. Then, the spool 114 is transferred. The clearance between a pressure port 114d and an E port is narrowed while L port 114c for lubricating oil is communicated with a narrow clearance and the pressure oil flows into a hydraulic clutch through the E port.</p> |
