JPS618693U

JPS618693U - Pump control circuit for cranes, etc.

Info

Publication number: JPS618693U
Application number: JP9249284U
Authority: JP
Inventors: 和明井上
Original assignee: Sumitomo Heavy Industries Ltd
Current assignee: Sumitomo Heavy Industries Ltd
Priority date: 1984-06-22
Filing date: 1984-06-22
Publication date: 1986-01-18

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

第１図は本考案に係る制御回路図。第２図は従来公知の制御回路図。図において；１・・・油圧ポンプ、２・・・方向切換弁
、３・・・リリーフ弁、４・・・油圧モータ、５，６・
・・（モータの）駆動回路、７・・・カウンターバラン
ス弁、８・・・戻り回路、９・・・操作用油圧ポンプ、
１０・・・パイロット弁、１１．１２・・・（パイロッ
ト弁の）２次側回路、１３・・・シャットル弁、１４・
・・（シャットル弁の）出口側の管路、１５・・・リリ
ーフ弁、１６・・・ポンプ、１７・・・圧力制御弁、１
８・・・方向切換弁、１９・・・アクチュエータ、２０
，２０′・・・給排管路、２１・・・パイロット圧制御
弁、２１ａ・・・操作レバー、２２・・・（高圧選択用
）シャトル弁、２３・・・制御部、２４・・・パイロッ
ト圧受圧部、２５・・・比例分割弁、２６・・・パイロ
ット圧力源、２７・・・タンク。FIG. 1 is a control circuit diagram according to the present invention. FIG. 2 is a conventionally known control circuit diagram. In the figure: 1... Hydraulic pump, 2... Directional switching valve, 3... Relief valve, 4... Hydraulic motor, 5, 6...
...(motor) drive circuit, 7...counter balance valve, 8...return circuit, 9...hydraulic pump for operation,
10...Pilot valve, 11.12...(Pilot valve) secondary side circuit, 13...Shuttle valve, 14.
... Pipe line on the outlet side (of the shuttle valve), 15 ... Relief valve, 16 ... Pump, 17 ... Pressure control valve, 1
8... Directional switching valve, 19... Actuator, 20
, 20'... Supply/discharge pipe line, 21... Pilot pressure control valve, 21a... Operation lever, 22... Shuttle valve (for high pressure selection), 23... Control unit, 24... Pilot pressure receiving section, 25... proportional division valve, 26... pilot pressure source, 27... tank.

Claims

[Scope of utility model registration request]

It has a pilot pressure control valve that switches and controls the pilot pressure from the pilot pressure source, and two of the pilot pressure control valves
A speed control system for cranes, etc., configured to control a variable displacement hydraulic pump according to the following pressure, and to control a directional control valve that switches and controls discharge oil from the pump according to the operation amount of the pilot pressure control valve. In the road, the control section of the variable displacement hydraulic pump is set to the minimum discharge amount necessary to move the actuator at a slow speed, and the secondary pressure from the pilot pressure control valve is applied to the control section of the pump. A pump control circuit for a crane or the like, characterized in that a proportional division valve is provided which proportionally divides the secondary pressure on the way to the pilot pressure receiving part, and the proportional division ratio of the proportional division valve is arbitrarily variable.