US 11,674,468 B2
Evaporative fuel processing device
Yuichiro Miura, Kariya (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on Sep. 3, 2021, as Appl. No. 17/466,962.
Claims priority of application No. JP2020-149722 (JP), filed on Sep. 7, 2020.
Prior Publication US 2022/0074364 A1, Mar. 10, 2022
Int. Cl. F02D 41/22 (2006.01); F02M 25/08 (2006.01); F02M 35/10 (2006.01)
CPC F02D 41/22 (2013.01) [F02M 25/0818 (2013.01); F02M 25/0836 (2013.01); F02M 25/0872 (2013.01); F02M 35/10222 (2013.01); F02D 2041/225 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An evaporative fuel processing device for determining a leak in an evaporation piping system that is defined by a fuel tank connected to a canister absorbing evaporated fuel via a vapor passage, an atmospheric on-off valve provided in an atmospheric passage that connects the canister and an air opening, and a purge valve provided in a purge passage that connects the canister and an intake passage, the evaporative fuel processing device comprising:
a pump, configured to pressurize or depressurize an internal pressure of the evaporation piping system for leak determination, pressurizing the internal pressure to a positive value with respect to an atmospheric pressure or depressurize the internal pressure to a negative value with respect thereto;
a pressure sensor, configured to detect the internal pressure; and
an abnormality determination device comprising processor and a computer-readable storage medium storing instructions which upon execution by the processor causes the an abnormality determination device to be configured to determine whether (i) the evaporation piping system has a leak hole or (ii) the pump has an abnormality based on the internal pressure detected by the pressure sensor, wherein
the abnormality determination device shifts between modes, the modes including:
(A) a normal leak determination mode for determining a presence or absence of the leak hole in the evaporation piping system when an absolute value of the internal pressure reaches a target value by an operation of the pump based on an assumption that the pump is normal, and in the normal leak determination mode, the abnormality determination device determines that the evaporation piping system has the leak hole when the absolute value of the internal pressure of the system is equal to or less than a normal leak determination threshold value after lapse of a determination time from stop of the operation of the pump, and
(B) a pump abnormality determination mode for determining abnormality of the pump when the absolute value of the internal pressure does not reach the target value by an operation of the pump.