| 摘要 |
PURPOSE:To enable a valve opening to be stably regulated, by providing a main valve and variable orifices in a small contour shaft part. CONSTITUTION:The rear end part of a sleeve 24 is adapted to the rear end surface of a back chamber 20. An oil path 30 provides variable orifices 34 to be placed in their fully opened condition for the back chamber 20. If the pressure of oil acts in a front chamber 14, a poppet 12 is retreated by the pressure of oil acting in the front chamber 14 without causing an increase of internal pressure in a rear chamber 16 because the pressure oil is allowed to both flow into the rear chamber 16 and the back chamber 20 and flow out to the outside via a discharge passage 40. If the variable orifice 34, whose opening is gradually decreased by retreating a small contour shaft part 22, is placed in an almost closed condition, the poppet 12 is stabilized holding its predetermined opening by allowing most of the pressure oil to flow into the rear chamber 16 through the oil path 30, as the result, by increasing the internal pressure in the rear chamber 16 to be balanced with the pressure in a side of the front chamber 14 together with the action of a spring 28. |
