| 摘要 |
PROBLEM TO BE SOLVED: To provide a tilting control device of variable capacity type hydraulic pump which can obtain a metering characteristic to facilitate the minute operation. SOLUTION: While a regulator 9 including a servo piston 2 which can change the tilting angle of a hydraulic pump 1; a change-over valve 5 (a first change- over value) having the servo piston 2 and a sleeve 51 and spool 52 which connects either one of the hydraulic pump 1 or a tank 6 selectively, a spring 11 to energize the end 53 of the spool 52; and a pilot piston 13 to abut to the end 54 of the spool 52; is provided, a difference in level is formed to the pilot piston 13 to provide the first pressure receiving surface 13c and the second pressure receiving surface 13d, and a second change-over valve 7 having the first change-over position 7a to feed a specific command pressure to only the first pressure receiving surface 13x, the second change-over position 7b to feed to only the second pressure receiving surface 13d, and the third change-over position 7c to feed to both the pressure receiving surfaces 13c and 13d, is provided. |
