Patent ID: 9303600
Filing Date: 2016-04-05
CPC Classification: F02M

Claim Text:
1. A fuel vapor leakage detection device, comprising: a canister connection passage connected to a canister that absorbs a fuel vapor in a fuel tank; an air passage for allowing fluid communication between the canister connection passage and atmosphere; a pressure detection passage for allowing fluid communication with the canister connection passage; a switching valve selectively switching fluid communication of the canister connection passage with one of the pressure detection passage or the air passage; a bypass passage for bypassing the switching valve that provides fluid communication between the canister connection passage and a pressure detection passage; a pressure-depressure unit (i) pressurizing or depressurizing the fuel tank and the canister when the switching valve establishes fluid communication between the canister connection passage and the pressure detection passage and (ii) pressurizing or depressurizing the air passage when the switching valve establishes fluid communication between the canister connection passage and the air passage; a throttle positioned within the bypass passage; a pressure detector detecting a pressure of the pressure detection passage and outputting a signal according to a detected pressure of the pressure detection passage; a purge valve fluidly connected to a purge passage, the purge valve opening and closing fluid communication between an intake air passage of an internal combustion engine and the canister; a valve controller for controlling the switching valve and the purge valve; a purge passage clog determination unit configured to determine a clog of the purge passage that is in communication with the pressure detection passage based on the pressure of the pressure detection passage which is detected by the pressure detector; an air passage clog determination unit configured to determine a clog of the air passage that is in communication with the pressure detection passage based on the pressure of the pressure detection passage; and an Electronic Control Unit (ECU) configured to control an operation of each of the pressure-depressure unit, the pressure detector, the valve controller, the purge passage clog detection unit, and the air passage clog detection unit, via an electrical connection with the pressure-depressure unit, the pressure detector, the valve controller, wherein the ECU is configured to determine a clog of the purge passage based on a detection result of the purge passage clog determination unit, determine a clog of the air passage based on a detection result of the air passage clog determination unit, and determine a leakage of the fuel vapor from the fuel tank, from the canister or from the purge passage within a preset time.