| 摘要 |
1,137,538. Hydraulic pressure intensifiers. NARADI NARODNI PODNIK. May 19, 1966 [May 20, 1965], No. 22237/66. Heading F1P. The high-pressure cylinder space 4 Fig. 2 of a hydraulic intensifier is formed within a hollow double-acting low-pressure piston 3 reciprocably mounted within a cylinder 1 and the high-pressure piston 5 which is also double-acting is fixed to a stationary head 6 of the intensifier body 2. In operation low-pressure oil admitted through an inlet 7 to a bore 14 is distributed by a hydraulically actuated spool valve 21 Fig. 4 along a bore 22 leading to the space below the lower end of piston 3 whilst the space above the upper end of said piston is connected through a bore 23 and the valve 21 to an outlet bore 13 and connection 8. Piston 3 is thereby raised and high-pressure oil is forced past a non-return valve 25 in the enlarged lower end of piston 5, an axial bore 5a and a non-return valve 11 at an outlet 10 having a relief valve 9, Fig. 6. At the end of the upward stroke the piston 3 actuates a lever 18 which in turn displaces an auxiliary spool valve 17 to an end position in which is connects an inlet branch 14c to one end of the main spool valve 21 to displace it to its other position whereof the return stroke of piston is initiated. High-pressure oil is then forced from the annular space surrounding the narrow portion of piston 5 through ports 5b and into bore 5a; valve 25 being closed, and 24 open. In a modification the double-acting lowpressure piston comprising upper and lower isolated connected portions 3a' 3b' Fig. 8 are reciprocated by compressed air distributed by a spool valve 21' either to the cylinder spaces below or above each piston 3a', 3b'. The high-pressure cylinder space 4' is filled with oil forced by air pressure from a tank 13' Fig. 7 up a fixed tube 13b' and a tube 13' slidable therein and projecting downwardly, from piston 3b'. The auxiliary spool valve for actuating valve 21' is operated by rod 18' when the latter is abutted by the inner ends of pistons 3a', 3b'. |
