Purge valve control method and control device of evaporated fuel processing device

A purge valve control device for an evaporative fuel processing device, comprising:

• a canister structured to adsorb evaporative fuel;
• at least one purge valve disposed in a purge passage between the canister and an intake passage of an internal combustion engine;
• and
• a controller configured to duty-control the at least one purge valve;
• wherein the controller is configured to drive the at least one purge valve by:
• synchronizing a cycle, in which the at least one purge valve is opened, with rotation of the internal combustion engine;
• setting a valve opening interval at one half of an odd number times an intake stroke interval, wherein the valve opening interval is from a start point of a first opening time period of the at least one purge valve to a start point of a second opening time period of the at least one purge valve, wherein the second opening time period follows the first opening time period, wherein the intake stroke interval is determined by a number of cylinders of the internal combustion engine;
• and
• setting the odd number to a value of a mathematical expression of (2·C+1), wherein C represents the number of cylinders of the internal combustion engine.