| 摘要 |
<p>PURPOSE:To enable high response changeover control to be executed by making use of pressurized air as a driving source of a driving mechanism for moving a cam pieces, etc., in a captioned device where a pumping valve is changed over and controlled in two stages by moving the cam piece, etc. CONSTITUTION:A cam piece 3 is fitted in a bearing part 2 formed in a body on a cam shaft 1 rotatably and slidably in the axial direction. The cam piece 3 is formed by providing in a body the first cam 5 for low speed rotation, the second cam 6 for high speed rotation and a flange-shaped member 8. A cylindrical fixed member 17 is provided near the cam shaft 1 parallely thereto, and a driving part 18 is slidably fitted in the outer periphery thereof. A timing mechanism 19 is provided on the cam piece 3 side of said driving part 18, and said flange- shaped member 8 is inserted into a slit 27 provided in a cylindrical part 20. The driving mechanism 18 forces a plunger 29 to displace in the axial direction by means of pressurized air supplied to and discharged from respective right and left chambers 31, 30 thereof, and controls an axial position of the cam piece 3 via the cylindrical part 20.</p> |
