Vehicle equipped with a hydraulically-operated device

{
  "publication_number": "US9316167B2",
  "country": "US",
  "kind": "B2",
  "title": "Vehicle equipped with a hydraulically-operated device",
  "abstract": "A vehicle equipped with a hydraulically-operated device includes an engine that drives the hydraulically-operated device, a temperature detection unit that detects a temperature of the engine or hydraulic oil and a control unit that controls the engine. The control unit is allowed to control torque of the engine in accordance with a predetermined specified torque limit value when the control unit is in an Eco-mode, and does not control the torque of the engine in accordance with the specified torque limit value in the Eco-mode when the temperature detected by the temperature detection unit is a predetermined specified release temperature or lower. The release temperature is set as a temperature at which output of the engine is hard to be stabilized.",
  "claims": [
    "1. A vehicle equipped with a hydraulically-operated device comprising: an engine that drives the hydraulically-operated device; a temperature detection unit that detects a temperature of the engine or hydraulic oil; and a control unit that controls the engine, wherein the control unit is allowed to control torque of the engine in accordance with a predetermined specified torque limit value when the control unit is in an Eco-mode, the control unit controls the engine without controlling the torque of the engine in accordance with the specified torque limit value in the Eco-mode when the temperature detected by the temperature detection unit is at a predetermined release temperature or lower, and the release temperature is set as a temperature at which output of the engine is hard to be stabilized when the torque of the engine is controlled.",
    "2. The vehicle equipped with the hydraulically-operated device according to claim 1, wherein when the detected temperature is at a predetermined specified temperature or higher, the control unit controls the torque of the engine in accordance with the specified torque limit value in the Eco-mode, and the specified temperature is higher than the release temperature.",
    "3. The vehicle equipped with the hydraulically-operated device according to claim 2, wherein when the detected temperature has exceeded the release temperature, the control unit changes a torque limit value gradually with an increase of the detected temperature until the detected temperature reaches the specified temperature.",
    "4. The vehicle equipped with the hydraulically-operated device according to claim 2, wherein when the detected temperature has exceeded the release temperature, the control unit performs both a temperature-dependent control in which the torque limit value is changed gradually with an increase of the detected temperature until the detected temperature reaches the specified temperature, and a time-dependent control in which the torque limit value is changed gradually with the elapse of time, and compares a change rate of the torque limit value per unit time when the temperature-dependent control is performed and a change rate of the torque limit value per unit time when the time-dependent control is performed to perform one of the controls whose change rate is smaller.",
    "5. The vehicle equipped with the hydraulically-operated device according to claim 1, wherein when the detected temperature has exceeded the release temperature, the control unit changes the torque limit value gradually with elapse of time."
  ],
  "description_excerpt": "The present invention relates to a vehicle equipped with a hydraulically-operated device.\n\nIn view of the demand for the fuel economy, there has been proposed a hybrid vehicle in which an economy mode (Eco-mode) is selectable. The Eco-mode may be turned ON or activated by pressing an Eco-mode switch. When the Eco-mode is thus selected, the engine output torque is changed from the torque that is required during normal operation of the vehicle to the torque that is controlled for energy saving so that the engine of the vehicle is operated with efficiency. Such vehicle is disclosed, for example, by Japanese Unexamined Patent Application Publication No. 2008-105532.\n\nIn the hybrid vehicle disclosed in the above-cited Publication, the improvement of the fuel economy and the simultaneous maintenance of the required vehicle performance (the required torque) are accomplished by operating the engine efficiently and supplementing the engine with torque using a motor in the Eco-mode. Unlike such hybrid vehicle, however, in the vehicle that is powered by an engine and has no motor, no torque can be supplemented to the engine.\n\nTherefore, in a forklift truck powered by an engine that is equipped with a hydraulically-operated device, there is a fear that an engine stall may occur in the Eco-mode due to insufficient engine torque attributable to a rapid increase of the load occurring during the loading operation. Particularly, immediately after a start of the engine, for example, the engine is not sufficiently warmed up and the engine output is yet to be stabilized.",
  "cpc": [
    "F02D 41/068",
    "B60W 10/06",
    "B60W 2300/121",
    "B60W 2510/0676",
    "B60W 2710/0666",
    "B60W 2710/0672",
    "B60W 30/194",
    "B66F 9/06",
    "B66F 9/07572",
    "B66F 9/20",
    "F02D 2001/0075",
    "F02D 2001/167",
    "F02D 2200/101",
    "F02D 2200/604",
    "F02D 2200/606",
    "F02D 2250/26",
    "F02D 29/02",
    "F02D 29/04",
    "F02D 41/021",
    "F02D 41/1498"
  ],
  "ipc": [
    "B60W 10/06",
    "B60W 20/00",
    "B60W 30/194",
    "B66F 9/04",
    "B66F 9/06",
    "B66F 9/075",
    "F02D 1/00",
    "F02D 1/16",
    "F02D 29/02",
    "F02D 29/04",
    "F02D 41/06"
  ],
  "assignees": [
    "Toyota Industries Corp"
  ],
  "inventors": [
    "Norihiko Kato",
    "Yukikazu Koide"
  ],
  "filing_date": "2015-03-23",
  "publication_date": "2016-04-19",
  "grant_date": "2016-04-19",
  "priority_date": "2014-03-26",
  "application_number": "US-201514665241-A",
  "family_id": "52780830",
  "cited_by_count": 1,
  "citations": [
    "EP1267075A2",
    "US20070239339A1",
    "JP2008105532A",
    "JP2009127548A",
    "WO2011115290A1",
    "US20110320095A1"
  ]
}