{
  "$type": "site.standard.document",
  "description": "The invention relates to a metering device comprising a housing (12) having a metering opening (22), controllable by the movement of an axially moveable valve needle, an axially extendable piezoelectric actuator (28) cooperating with the valve needle to control its axial movement, and a thermal…",
  "path": "/patents/1089458",
  "publishedAt": "2004-02-25T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F02M51/0603",
    "SIEMENS VDO AUTOMOTIVE SPA [IT]"
  ],
  "textContent": "The invention relates to a metering device comprising a housing (12) having a metering opening (22), controllable by the movement of an axially moveable valve needle, an axially extendable piezoelectric actuator (28) cooperating with the valve needle to control its axial movement, and a thermal compensator unit (30) to compensate for different thermal expansion of the housing (12) and the piezoelectric actuator (28). According to the invention the thermal compensator unit (30) comprises a compensator housing (32) and a hydraulic piston (34), disposed axially slidable within the compensator housing (32), the compensator housing (32) and the piston (34) forming a first fluid chamber (36), a second fluid chamber (38) and a throttling passage (40) connecting the first (36) and second fluid chamber (38), and means for transmitting an axial extension of the piezoelectric actuator (28) to the compensator housing (32) or to the piston (34) to urge a hydraulic fluid from the first fluid chamber (36) to the second fluid chamber (38) in an activation phase of the piezoelectric actuator (28).",
  "title": "Metering device with thermal compensator unit"
}