{
  "$type": "site.standard.document",
  "description": "A control valve device (16) comprises two direction control valves (20) and (21). The direction control valve (20) includes an expansion side variable throttle portion (20C) and a contraction side variable throttle portion (20D). The direction control valve (21) includes an expansion side variable…",
  "path": "/patents/985967",
  "publishedAt": "2013-03-06T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B60P1/162",
    "HITACHI CONSTRUCTION MACHINERY [JP]"
  ],
  "textContent": "A control valve device (16) comprises two direction control valves (20) and (21). The direction control valve (20) includes an expansion side variable throttle portion (20C) and a contraction side variable throttle portion (20D). The direction control valve (21) includes an expansion side variable throttle portion (21C) and a contraction side variable throttle portion (21D). When a hoist cylinder (10) is telescopically operated to raise or lower a vessel (3), as the hoist cylinder (10) approaches a stop position, a controller (35) determines that the hoist cylinder (10) gets close to the stop position. Based upon this determination, the controller (35) variably adjusts a flow passage area of the direction control valve (20) using the variable throttle portions (20C) and (20D) or variably adjusts a flow passage area of the direction control valve (21) using the variable throttle portions (21C) and (21D) in such a manner as to slow down or speed up the telescopic speed of the hoist cylinder (10) corresponding to the weight in the side of vessel (3).",
  "title": "TRANSPORTATION VEHICLE"
}