| 摘要 |
<p>PURPOSE:To prevent a shock generated by a sudden clutch connection by disposing a drain circuit communicating with a tank port in the midway of an oil path extending from a hydraulic pump to a hydraulic cylinder chamber and providing a pressure accumulating buffer chamber on an extension line of an operation rod. CONSTITUTION:When a start switch 3 is turned on, an electric current is applied to a solenoid 4 so that an operation rod 5 is protruded to the right. Whereupon, a spool 6 is pushed to the right, and a part of operation oil fed out by a hydraulic pump 8 reaches an oil path 14 communicating with a PTO clutch 2, a part thereof being discharged through a drain oil path 12 to a tank 11. At this time, a mover 20 is pushed to the right by a spool 6, and oil in the right chamber 19a in an pressure accumulating chamber 19 flows into the left chamber 19b through a through hole 20b, so that the moving speed of the spool 6 is temporarily held down to keep the half-connection state of a clutch. When the spool 6 is further pushed in, only the oil path 14 communicates with a pressurized oil supply path 9 to completely engage the clutch.</p> |
