Oil pressure controller for automatic transmission

Patent metadata

Field	Value
Publication number	US-10047853-B2
Application number	US-201414915837-A
Country	US
Kind code	B2
Filing date	Aug 27, 2014
Priority date	Sep 13, 2013
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

Oil pressure controller for an automatic transmission produces a pre-charge shelf pressure supplied to a starter clutch by rapidly decreasing a command hydraulic pressure to the starter clutch after temporarily rapidly increasing the command hydraulic pressure, also produces a capacity adjustment pressure (Pb1 or Pb2) of the starter clutch by gradually increasing the hydraulic pressure from a decrease point of the pre-charge shelf pressure (Pa), when a selecting operation is made from N-range to D-range. By changing capacity adjustment pressure (Pb1 or Pb2) according to brake-operating/nonoperating state, capacity adjustment pressure (Pb1) in the brake-nonoperating state is set to be higher than capacity adjustment pressure (Pb2) in the brake-operating state by an offset hydraulic pressure amount. With this, when the selecting operation is made from N-range to D-range, in the brake-operating state, selection shock of the starter clutch can be reduced. In the brake-nonoperating state, good vehicle startability can be achieved.

First claim

The invention claimed is:

1. An oil pressure controller for an automatic transmission, the oil pressure controller producing a pre-charge shelf pressure supplied to a starter clutch by rapidly decreasing a command hydraulic pressure to the starter clutch after temporarily rapidly increasing the command hydraulic pressure and also producing a capacity adjustment pressure of the starter clutch by gradually increasing the command hydraulic pressure after decreasing the pre-charge shelf pressure when a selecting operation is made from a neutral range to a drive range, the oil pressure controller comprising:
a brake state detecting unit that detects a brake-operating/nonoperating state of a vehicle mounting the automatic transmission, and
the command hydraulic pressure in the brake-nonoperating state being set to be higher than the command hydraulic pressure in the brake-operating state, and
when a brake is changed from the brake-operating state to the brake-nonoperating state during the progress of production of the capacity adjustment pressure on the basis of the selecting operation from the neutral range to the drive range, the capacity adjustment pressure in the brake-nonoperating state being produced while gradually increasing the capacity adjustment pressure in the brake-operating state.

2. The oil pressure controller for the automatic transmission as claimed in claim 1 , wherein:
the capacity adjustment pressure in the brake-nonoperating state is a pressure obtained by adding a predetermined offset hydraulic pressure amount to the capacity adjustment pressure in the brake-operating state.

3. The oil pressure controller for the automatic transmission as claimed in claim 2 , wherein:
when a brake is changed from the brake-operating state to the brake-nonoperating state during the progress of production of the capacity adjustment pressure on the basis of the selecting operation from the neutral range to the drive range, the capacity adjustment pressure in the brake-nonoperating state is produced by adding the offset hydraulic pressure amount to the capacity adjustment pressure in the brake-operating state while gradually increasing the offset hydraulic pressure amount.

4. The oil pressure controller for the automatic transmission as claimed in claim 2 , wherein:
the offset hydraulic pressure amount is increased or decreased according to temperature of a working fluid.

Assignees

• Jatco Ltd

Inventors

• Kotsuji Kouichi
• Hattori Kenji

Classifications

• F16D2500/50293

  Reduction of vibrations · CPC title

• F16D2500/50224

  Drive-off · CPC title

• F16H61/0265

  for gearshift control, e.g. control functions for performing shifting or generation of shift signals · CPC title

• F16H61/0437

  by using electrical signals (F16H61/0403 and F16H61/061 take precedence) · CPC title

• F16H59/54

  dependent on signals from the brakes, e.g. parking brakes · CPC title