Oil jet device

An oil jet device comprising:

• a main body mounted on an internal combustion engine and having a fluid communication passage held in fluid communication with an oil passageway defined in said internal combustion engine;
• a nozzle pipe having an oil ejection port configured to eject oil that has passed through said fluid communication passage;
• a check valve configured to open and close said fluid communication passage when a valve body and a valve seat which are disposed in said main body abut against each other;
• and
• a filter having a fluid communication hole configured to pass the oil therethrough and filter the oil, said filter being disposed upstream of said check valve and disposed in or on said main body,
• wherein an inside diameter of said valve seat is smaller than an inside diameter of said filter, and said valve seat has an upstream end wall surface facing at least some of said fluid communication holes, and
• said upstream end wall surface includes a slanted surface arranged such that a cross-sectional area of an oil channel is progressively smaller in a direction from an upstream region toward a downstream region of the fluid communication passage.