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US 2017/0305268 A1Published application
Automatic transmission
AssigneesAisin Aw Co., Ltd., Toyota Jidosha Kabushiki Kaisha
InventorsYuhei YOSHIOKA, Yasushi SATO, Toshihiko KAMIYA, Akio MURASUGI, Masahide ICHIKAWA
Life of this patent
Estimating the term…
Abstract
An automatic transmission where the control portion controls the adjustment solenoid valve so that the circulation hydraulic pressure equals to a second circulation hydraulic pressure higher than the first circulation hydraulic pressure when the rotational speed difference between the output rotational speed of the fluid transmission device and the rotational speed of the driving source is more than the predetermined rotational speed.
Claims18
1-12. (canceled)
An automatic transmission comprising:
- a fluid transmission device fluid-transmitting rotation of a driving source via oil filled therein;
- a transmission mechanism changing an output rotational speed from the fluid transmission device and outputting a changed rotational speed;
- a hydraulic pressure control device including a circulation hydraulic pressure adjustment valve adjusting a hydraulic pressure discharged by an oil pump to a circulation hydraulic pressure circulating through the fluid transmission device and an adjustment solenoid valve supplying a signal pressure to the circulation hydraulic pressure adjustment valve;
- and
- a control portion that acquires a rotational speed of the driving source and that acquires an output rotational speed of the fluid transmission device, wherein:
- the control portion controls the adjustment solenoid valve so that the circulation hydraulic pressure equals to a first circulation hydraulic pressure when a rotational speed difference between the output rotational speed of the fluid transmission device and the rotational speed of the driving source is equal to or less than a predetermined rotational speed and
- the control portion controls the adjustment solenoid valve so that the circulation hydraulic pressure equals to a second circulation hydraulic pressure higher than the first circulation hydraulic pressure when the rotational speed difference between the output rotational speed of the fluid transmission device and the rotational speed of the driving source is more than the predetermined rotational speed.
4 more elements
An automatic transmission comprising:
- a fluid transmission device fluid-transmitting rotation of a driving source via oil filled therein;
- a transmission mechanism changing an output rotational speed from the fluid transmission device and outputting a changed rotational speed;
- a hydraulic pressure control device including a circulation hydraulic pressure adjustment valve adjusting a hydraulic pressure discharged by an oil pump to a circulation hydraulic pressure circulating through the fluid transmission device and an adjustment solenoid valve supplying a signal pressure to the circulation hydraulic pressure adjustment valve;
- and
- a control portion controlling the adjustment solenoid valve so that the circulation hydraulic pressure equals to a first circulation hydraulic pressure when the fluid transmission device is filled with oil and controlling the adjustment solenoid valve so that the circulation hydraulic pressure equals to a second circulation hydraulic pressure higher than the first circulation hydraulic pressure when the oil has leaked from the fluid transmission device.
2 more elements
Dependencies are inferred from the claim text.