To provide a hydraulic circuit using a variable displacement hydraulic pump which controls to an approximately zero swash plate angle, enhancing the responsiveness of a load sensing valve controlling the swash plate angle of the hydraulic pump even if a small diameter pipe is used, and achieving improved peak pressure reducing effect.
Load pressure of an actuator 6 and spring force of a spring 2a which are taken out through a pilot oil passage 14 act on one end surface of the load sensing valve 2, and the intermediate pressure of the pump pressure of a discharge oil passage 10, which is taken out by a pilot oil passage 13 and a pilot oil passage 15, acts on the other end surface of the load sensing valve 2 through a merged pressure oil passage 20. A hose with a large inside diameter is used for a discharge oil passage 10b and a pilot oil passage 15b, and thereby pipe resistance in the discharge oil passage 10 and pilot oil passage 15 is reduced.
| JP2006132683 | HYDRAULIC DRIVE UNIT |
| JPH11230104 | CONSTANT SPEED CONTROL DEVICE FOR HYDRAULIC MACHINE |
KATAOKA TOYOMI
WAKIZAKA AKIYUKI
OSHIRO MITSURU
SHINBASHI KIJIN
| JP2006090419A | 2006-04-06 | |||
| JPS57157802A | 1982-09-29 | |||
| JPH0518365A | 1993-01-26 |
Katsutoshi Shiozawa