US 11,674,477 B2
Leak hole determination device of evaporated fuel processing device
Keiichirou Ishihara, Kariya (JP); Tomohiro Itoh, Kariya (JP); and Yasuo Katoh, Kariya (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on May 18, 2021, as Appl. No. 17/323,340.
Claims priority of application No. JP2020-088734 (JP), filed on May 21, 2020.
Prior Publication US 2021/0363942 A1, Nov. 25, 2021
Int. Cl. F02M 25/08 (2006.01); G01M 3/28 (2006.01)
CPC F02M 25/0809 (2013.01) [G01M 3/2815 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A leak hole determination device located in an evaporated fuel processing system and configured to determine a presence or an absence of a leak hole the system, wherein the system includes: the device; a fuel tank; and a canister for absorbing an evaporated fuel discharged from the fuel tank, and wherein the device comprises:
a first pressure detector configured to detect a first pressure in the fuel tank;
a second pressure detector configured to detect a second pressure in the canister; and
a leak hole determiner configured to determine whether a leak hole is present or not by using either of (A) a change speed difference between a first pressure change speed of the first pressure detected by the first pressure detector and a second pressure change speed of the second pressure detected by the second pressure detector after a limit pressure timing or (B) a pressure difference between the first pressure detected by the first pressure detector and the second pressure detected by the second pressure detector after the limit pressure timing, wherein
the limit pressure timing is a timing at which the first pressure detected by the first pressure detector and the second pressure detected by the second pressure detector respectively take a limit pressure value due to a pressurization operation or a depressurization operation for pressurizing or depressurizing an inside of the system.