Title:
HYDRAULIC CIRCUIT FOR CYLINDER FOR TELESCOPIC ARM
Document Type and Number:
Japanese Patent JP3553186
Kind Code:
B2
Abstract:
PURPOSE: To increase the extending and retracting speed of hydraulic cylinder for telescopic arms, in an excavator to the top end of which the telescopic arms to be used for construction work and civil engineering are attached.
CONSTITUTION: In order that an extending speed of a hydraulic cylinder 5 for telescopic arms is increased, pipe lines 24, 25, 26 connected between a pipe lines 21b at the head side of the hydraulic cylinder 5 and a pipe line 22b at the bottom side thereof are provided, and a speed-increasing circuit in which discharged oil from the head side is allowed to flow into pressurized oil of the bottom side is formed between them. A drain circuit for dropping a back pressure of the hydraulic cylinder 5 during its retraction is allowed to branch at the pipe line 22b connected to the bottom side and oil therein is directly drained into a tank 7, and thus the back pressure is decreased and a retracting speed of the hydraulic cylinder 5 is increased.
Inventors:
Akihiro Toyomura
Hideaki Akagi
Hideaki Akagi
Application Number:
JP7965895A
Publication Date:
August 11, 2004
Filing Date:
March 09, 1995
Export Citation:
Assignee:
KOMATSU LTD.
International Classes:
E02F9/22; E02F3/39; E02F3/47; (IPC1-7): E02F3/39; E02F3/47; E02F9/22
Domestic Patent References:
| JP5321289A | ||||
| JP6307407A |