| 摘要 |
PURPOSE:To prevent the abrasion of a stem section by providing an annular tongue piece made of a flexible material and capable of making a contact angle on its inward bent tip edge smaller than the contact angle when a valve body is opened, on the peripheral surface of the stem of the valve body. CONSTITUTION:An annular tongue piece 4 made of a heat-resistant flexible material, preferably Teflon, etc., and capable of making a contact angle alpha of an opened valve body smaller than the contact angle beta of the closed valve body with an inward bent tip edge brought into looseby contact with the peripheral surface of the stem section 2' of a valve body 2 side is fixed to the upper end of a valve guide cylinder 3 in a state pinched by inner and outer cylinder metals to constitute an oil feed adjusting tool 5. First, when the valve body 2 is opened (when moved downward) with a contact angle alpha, the lubricating oil stuck to the peripheral surface of the stem section 2' is controlled preferably to an oil film thickness of about 1.2mu in conjunction with the looseby contact structure, and on the other hand, when the valve body 2 is closed (when returned upward) With a contact angle beta, the lubricating oil having remained between sliding faces is scraped down to an oil film thickness of about 1.0mu, thereby the lubricating oil is continuously fed to the sliding surface of the stem section 2' by utilizing the difference of the oil film thickness when the valve body 2 is opened and closed. |
