Power control device for cargo handling vehicle

{
  "publication_number": "US9500150B2",
  "country": "US",
  "kind": "B2",
  "title": "Power control device for cargo handling vehicle",
  "abstract": "A power control device for a cargo handling vehicle provided with a cargo handling apparatus operated by a hydraulic oil from a hydraulic pump driven by an engine includes a controller and an engine speed sensor detecting an engine speed. The controller controls an engine torque to be limited by using an engine torque limit value for limiting the engine torque, and controls the engine torque limit on the engine by an engine torque limiting unit to be canceled when the engine speed detected by the engine speed sensor is equal to or lower than a predetermined first engine speed.",
  "claims": [
    "1. A power control device for a cargo handling vehicle provided with a cargo handling apparatus operated by a hydraulic oil from a hydraulic pump driven by an engine, the power control device comprising: engine torque limiting means for controlling an engine torque to be limited by using an engine torque limit value; engine speed detection means for detecting an engine speed; and engine torque limit cancelling means for controlling a torque limit on the engine by the engine torque limiting means to be canceled when the engine speed detected by the engine speed detection means is equal to or lower than a predetermined first engine speed, wherein the engine torque limiting means sets the engine torque limit value to a predetermined value when the engine speed detected by the engine speed detection means is equal to or higher than a second engine speed higher than the first engine speed.",
    "2. The power control device for a cargo handling vehicle according to claim 1, wherein the engine torque limiting means includes means for storing an engine torque limit value map in which the engine torque limit value is associated with the engine speed and sets the engine torque limit value to a value corresponding to the engine speed by using the engine torque limit value map when the engine speed detected by the engine speed detection means is higher than the first engine speed and is lower than the second engine speed.",
    "3. The power control device for a cargo handling vehicle according to claim 1, wherein the second engine speed is lower than an idling engine speed of the engine.",
    "4. The power control device for a cargo handling vehicle according to claim 1, further comprising: an accelerator opening sensor detecting an accelerator opening, wherein the engine torque limiting means calculates a deviation between a target engine speed corresponding to the accelerator opening detected by the accelerator opening sensor and the engine speed detected by the engine speed detection means, calculates an engine torque command value based on the calculated deviation, adjusts the calculated engine torque command value with the engine torque limit value, and outputs the adjusted engine torque command value to the engine as a command signal so that the engine torque is controlled to be limited.",
    "5. A power control device for a cargo handling vehicle provided with a cargo handling apparatus operated by a hydraulic oil from a hydraulic pump driven by an engine, the power control device comprising: an engine speed sensor detecting an engine speed; and a controller configured to limit an engine torque by using an engine torque limit value and cancel a torque limit on the engine when the engine speed detected by the engine speed sensor is equal to or lower than a predetermined first engine speed, and set the engine torque limit value to a predetermined value when the engine speed detected by the engine speed sensor is equal to or higher than a second engine speed higher than the first engine speed."
  ],
  "description_excerpt": "Field of the Invention The invention relates to a power control device for a cargo handling vehicle. Related Background Art As described in, for example, Japanese Unexamined Patent Application Publication No. 2012-56763, a power control device for a cargo handling vehicle that produces a control command for obtaining an engine speed corresponding to a depression operation amount of an accelerator pedal and controls an engine output torque in accordance with the control command is known as a power control device for a cargo handling vehicle according to the related art. Realization of fuel saving is strongly desired for the power control device for a cargo handling vehicle described above. Regarding hybrid cars, a technique for improving fuel economy by switching from a normal demand torque to a demand torque for fuel saving when an eco-mode switch is pressed is known as described in, for example, Japanese Unexamined Patent Application Publication No. 2008-105532.\n\nIn the hybrid car described in Japanese Unexamined Patent Application Publication No. 2008-105532, an engine output is supplemented by a motor output in an eco-mode so that the fuel economy is improved while the demand torque as a vehicle performance is being maintained. In the engine-type cargo handling vehicle described in Japanese Unexamined Patent Application Publication No. 2012-56763, on which no motor is mounted, the engine torque is limited in the eco-mode so that the fuel economy is improved.",
  "cpc": [
    "F02D 41/083",
    "B66F 9/20",
    "B66F 9/22",
    "F02D 29/02",
    "F02D 29/04"
  ],
  "ipc": [
    "B66F 9/20",
    "B66F 9/22",
    "F02D 29/02",
    "F02D 29/04",
    "F02D 41/08"
  ],
  "assignees": [
    "TOYOTA JIDOSHOKKI KK"
  ],
  "inventors": [
    "KATO NORIHIKO",
    "KOIDE YUKIKAZU",
    "TANAKA HIROYUKI"
  ],
  "filing_date": "2015-03-20",
  "publication_date": "2016-11-22",
  "grant_date": "2016-11-22",
  "priority_date": "2014-03-24",
  "application_number": "US-201514663635-A",
  "family_id": "53039668",
  "citations": [
    "EP2644873A2",
    "GB2385844A",
    "JP2008105532A",
    "JP2012056763A",
    "US2004185986A1",
    "US2013089399A1",
    "US2013190996A1",
    "US2013261906A1",
    "US2014067174A1",
    "US7153235B2",
    "US8676457B2",
    "US8818654B2",
    "US8996259B2",
    "US9233684B2"
  ]
}