| 摘要 |
PURPOSE:To provide a fuel injector which facilitates the sealing performance test for an O-ring for separating the lubricating oil space and the fuel space of the fuel injectot and the airtightness inspecting method. CONSTITUTION:In an airtightness inspecting method for a fuel injector, the sliding gap between the bore 21 of a cylinder 2 and a plunger 3 is charged with liquid by charging the inside of the bore 12 of a pump housing 1 with liquid until the liquid level reaches the part between the lower edge of the cylinder 2 and an O-ring 5, and a gas pressure difference is generated between a fuel space F and a residual lubricating oil space L, and in this state the gas leak between the fuel space F and the reidual lubricating oil space L is detected. Accordingly, the gas leak between both the spaces F and L can be considered so as to be due to only the gas passing through the O-ring, and the sealing performance of the O-ring can be correctly inspected. |
