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US 9,753,456 B2Granted
Device for detecting decrease in rotational speed of cooling fan of machine tool
AssigneeFanuc Corporation
InventorsYoshinori Hoshino, Taisei Fujimoto
Life of this patent
Estimating the term…
Abstract
A machine tool including a cooling fan measures an input power source voltage to the machine tool and an input current to the cooling fan. If the measured current value is outside a predetermined current value range corresponding to the measured voltage value, the machine determines that the rotational speed of the cooling fan has decreased.
Claims10
A machine tool including a cooling fan, the machine tool comprising:
- a user interface unit configured to give a notice of a state of the machine tool;
- a current measuring unit configured to measure an input current to the cooling fan;
- a voltage measuring unit configured to measure an input power source voltage to the machine tool;
- a first storage unit storing a threshold of the input current corresponding to the input power source voltage, the first storage unit storing a plurality of voltage values stored in an ascending order;
- and
- a rotation-reduction determining unit configured
- to acquire, based on a measured current value measured by the current measuring unit and a measured voltage value measured by the voltage measuring unit, a threshold of the input current associated with the measured voltage value, from the first storage unit, and
- to output information indicating reduction in a rotational speed of the cooling fan to the user interface unit when the measured current value exceeds the acquired threshold of the input current.
5 more elements
A machine tool including a cooling fan, the machine tool comprising:
- a user interface unit configured to give a notice of a state of the machine tool;
- a current measuring unit configured to measure an input current to the cooling fan;
- a voltage measuring unit configured to measure an input power source voltage to the machine tool;
- a second storage unit storing a rotational speed reduction rate of the cooling fan associated with each combination of the input current and the input power source voltage wherein
- the second storage unit stores
- a plurality of voltage values sorted in an ascending order, and
- a plurality of current values sorted in an ascending order;
- a rotational speed estimating unit configured
- to estimate a rotational speed reduction rate of the cooling fan, based on a measured current value measured by the current measuring unit and a measured voltage value measured by the voltage measuring unit, and
- to output the estimated rotational speed reduction rate of the cooling fan to the user interface unit.
7 more elements
A cooling device configured to cool a machine including a cooling fan, the cooling device comprising:
- a current measuring unit configured to measure an input current to the cooling fan;
- a voltage measuring unit configured to measure an input power source voltage to the cooling fan;
- a second storage unit storing a rotational speed reduction rate of the cooling fan associated with each combination of the input current and the input power source voltage, wherein
- the second storage unit stores
- a plurality of voltage values sorted in an ascending order,
- a plurality of current values sorted in an ascending order;
- a rotational speed estimating unit configured
- to estimate a rotational speed reduction rate of the cooling fan, based on a measured current value measured by the current measuring unit and a measured voltage value measured by the voltage measuring unit, and
- to output the estimated rotational speed reduction rate of the cooling fan.
6 more elements
A cooling device configured to cool a machine including a cooling fan, the cooling device comprising:
- a current measuring unit configured to measure an input current to the cooling fan;
- a voltage measuring unit configured to measure an input power source voltage to the cooling fan;
- a first storage unit storing a threshold of the input current corresponding to the input power source voltage, the first storing unit storing a plurality of voltage values stored in an ascending order;
- and
- a rotation-reduction determining unit configured
- to acquire, based on a measured current value measured by the current measuring unit and a measured voltage value measured by the voltage measuring unit, a threshold of the input current associated with the measured voltage value, from the first storage unit, and
- to output information indicating reduction in a rotational speed of the cooling fan when the measured current value exceeds the acquired threshold of the input current.
4 more elements
Dependencies are inferred from the claim text.