Testing apparatus for fuel vapor treating device

A testing apparatus for a fuel vapor treating device, the treating device including a canister for collecting fuel vapor generated in a fuel tank through a vapor line, wherein the fuel in the tank is supplied to an engine, a purge line for purging the collected fuel in the canister into an air intake passage of the engine by a negative intake pressure generated in the intake passage during operation of the engine, a vapor control valve for adjusting a flow of the fuel vapor passing therethrough from the tank to the canister, wherein the vapor control valve opens in accordance with a difference between the pressure of the tank and the pressure of the canister, a purge control valve for adjusting a flow rate of fuel vapor passing through the purge line, wherein the opening of the purge control valve is duty controlled in accordance with a duty signal, and control means for controlling said purge control valve during operation of the engine, wherein the control means supplies the duty signal to the purge control valve, and wherein the duty control of the purge control valve causes pulsation of a negative intake pressure applied to the purge line from the air intake passage, the apparatus comprising:

• pressure detecting means for detecting the pressure at a canister side of the vapor control valve;
• first testing means for testing a malfunction related to a sealing of the canister side based on the detected pressure;
• first deciding means for deciding whether said control means terminates supplying the duty signal to the purge control valve after completion of the engine starting;
• second deciding means for deciding whether the detected pressure is lower than a predetermined reference value after a completion of the engine starting;
• third deciding means for deciding whether the pressure detected after completion of the engine starting is lower than the pressure detected before completion of the engine starting;
• and
• second testing means for determining that there is a malfunction hindering selective closing of the purge control valve, when the first deciding means decides that the control means terminates supplying the duty signal to the purge control valve after completion of the engine starting and the second deciding means decides that the detected pressure is lower than a predetermined reference value after a completion of the engine starting and the third deciding means decides that the pressure detected after completion of the engine starting is lower than the pressure detected before completion of the engine starting.

A testing apparatus for a fuel vapor treating device, the treating device including a canister for collecting fuel vapor generated in a fuel tank through a vapor line, wherein the fuel in the tank is supplied to an engine, a purge line for purging the collected fuel in the canister into an air intake passage of the engine by a negative intake pressure generated in the intake passage during operation of the engine, a vapor control valve for adjusting a flow of the fuel vapor passing therethrough from the tank to the canister, wherein the vapor control valve opens in accordance with a difference between the pressure of the tank and the pressure of the canister, a purge control valve for adjusting a flow rate of fuel vapor passing through the purge line, wherein the opening of the purge control valve is duty controlled in accordance with a duty signal, and control means for controlling said purge control valve during operation of the engine, wherein the control means supplies the duty signal to the purge control valve, and wherein the duty control of the purge control valve causes pulsation of a negative intake pressure applied to the purge line from the air intake passage, the apparatus comprising:

• pressure detecting means for detecting the pressure at a canister side of the vapor control valve;
• first testing means for testing a malfunction related to a sealing of the canister side based on the detected pressure;
• first deciding means for deciding whether said control means is supplying the duty signal to the purge control valve;
• second deciding means for deciding whether the detected pressure is higher than a predetermined reference value;
• third deciding means for deciding whether a pressure pulsation is absent in the detected pressure caused by the duty control of the purge control valve;
• second testing means for determining that there is a malfunction hindering selective opening of the purge control valve, when the first deciding means decides that the control means is supplying the duty signal to the purge control valve and the second deciding means decides that the detected pressure is higher than a predetermined reference value and the third deciding means decides that the pressure pulsation is absent in the detected pressure caused by the duty control of the purge control valve;
• fourth deciding means for deciding whether said control means terminates supplying the duty signal to the purge control valve after completion of the engine starting;
• fifth deciding means for deciding whether the detected pressure is lower than a predetermined reference value after a completion of the engine starting;
• sixth deciding means for deciding whether the pressure detected after completion of the engine starting is lower than the pressure detected before completion of the engine starting;
• and
• third testing means for determining that there is a malfunction hindering selective closing of the purge control valve, when the fourth deciding means decides that the control means terminates supplying the duty signal to the purge control valve after completion of the engine starting and the fifth deciding means decides that the detected pressure is lower than a predetermined reference value after a completion of the engine starting and the sixth deciding means decides that the pressure detected after completion of the engine starting is lower than the pressure detected before completion of the engine starting.