US 11,988,231 B2
Diagnostic device for hydraulic pressure control actuator
Takahiro Kinoshita, Tokyo (JP)
Assigned to SUBARU CORPORATION, Tokyo (JP)
Filed by Fuji Jukogyo Kabushiki Kaisha, Tokyo (JP)
Filed on Mar. 20, 2014, as Appl. No. 14/221,200.
Claims priority of application No. 2013-065499 (JP), filed on Mar. 27, 2013.
Prior Publication US 2014/0297137 A1, Oct. 2, 2014
Int. Cl. F16B 19/00 (2006.01); F15B 19/00 (2006.01)
CPC F15B 19/005 (2013.01) 12 Claims
OG exemplary drawing
 
1. A diagnostic device for a hydraulic pressure control actuator which drives a line pressure control valve to regulate a pressure of hydraulic oil between an upper limit line pressure and a lower limit line pressure, so that the pressure approaches a predetermined target line pressure, the hydraulic oil being discharged by a hydraulic pump which discharges hydraulic oil in an amount according to a driving revolution rate, the diagnostic device comprising:
an actual hydraulic pressure detection unit configured to detect an actual hydraulic pressure after the pressure is regulated by the line pressure control valve;
a determination value setting unit configured to set a high pressure fixation determination value which is increased as the driving revolution rate is increased so as to substantially match a characteristic of the hydraulic pressure control actuator at a time of high pressure fixation; and
a fixation determination unit configured to determine high pressure fixation of the hydraulic pressure control actuator when the actual hydraulic pressure substantially matches the high pressure fixation determination value with a difference between the target line pressure and the upper limit line pressure higher than or equal to a predetermined value.