JPS59135958U

JPS59135958U - Hydraulic excavator hydraulic circuit

Info

Publication number: JPS59135958U
Application number: JP2984983U
Authority: JP
Inventors: 三男相原; 勝木　公雄; 大坪　和彦
Original assignee: 日立建機株式会社
Priority date: 1983-03-03
Filing date: 1983-03-03
Publication date: 1984-09-11
Also published as: JPH0352280Y2

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図は従来の油圧ショベルの油圧回路を示す系統図、
第２図は従来の油圧ショベルの油圧回路を構成する主油
圧ポンプの圧力と吐出量との関係を示す特性線図、第３
図は油圧ショベルのフロン＝トアタッチメント油圧回路を示す系統図、第４図は第３
図の油圧回路を構成する主油圧ポンプの圧力と吐出量と
の関係を示す特性線図、第５図は油圧ショベルの走行油
圧回路を示す系統図、第６図は第５図の油圧回路を構成
する主油圧ポンプの圧力と吐出量との関係を示す特性線
図、第７図はこの考案による油圧回路の一実施例を示す
系統図である。１・・・主油圧ポンプ装置、２・・・可変容量形油圧ポ
ンプ、３・・・レギュレータ、４・・・カットオフバル
ブ、５・・・管路、６・・・サーボピストン、８・・・
油タンク、９・・・管路、１０・・・主リリーフバルブ
、１２・・・走行用コントロールバルブ、１３．１４・
・・パイロット管路、１５・・・パイロットバルブ、１
６・・・シャトルバルブ、１７・・・圧油取出し管路、
１８・・・シリンダ。ｉ−ゝ−１３１５２１−−−１廿−Ｔ′１Figure 1 is a system diagram showing the hydraulic circuit of a conventional hydraulic excavator.
Figure 2 is a characteristic diagram showing the relationship between the pressure and discharge amount of the main hydraulic pump that constitutes the hydraulic circuit of a conventional hydraulic excavator;
The figure is a system diagram showing the front attachment hydraulic circuit of a hydraulic excavator.
Figure 5 is a characteristic diagram showing the relationship between the pressure and discharge amount of the main hydraulic pump that constitutes the hydraulic circuit in Figure 5. Figure 5 is a system diagram showing the traveling hydraulic circuit of a hydraulic excavator. Figure 6 is a diagram showing the hydraulic circuit in Figure 5. FIG. 7 is a characteristic diagram showing the relationship between the pressure and the discharge amount of the main hydraulic pump that constitutes the main hydraulic pump, and is a system diagram showing an embodiment of the hydraulic circuit according to this invention. DESCRIPTION OF SYMBOLS 1... Main hydraulic pump device, 2... Variable displacement hydraulic pump, 3... Regulator, 4... Cutoff valve, 5... Pipe line, 6... Servo piston, 8...・
Oil tank, 9... Pipe line, 10... Main relief valve, 12... Traveling control valve, 13.14.
...Pilot line, 15...Pilot valve, 1
6...Shuttle valve, 17...Pressure oil extraction pipe,
18...Cylinder. i-ゝ-1315 2 1----1廿-T'1

Claims

[Scope of utility model registration request]

, a hydraulic excavator in which the discharge end of a variable displacement hydraulic pump equipped with a regulator and a cut-off mechanism is connected to a travel control valve, and - the pressure receiving part of the travel control valve and a pilot valve are connected through pilot pipes, respectively. In the hydraulic circuit, the pilot pipes are connected to each other via a shuttle valve, and the pressure oil outlet pipe of the shuttle valve is connected to the hydraulic oil chamber of the cylinder that stops the operation of the cut-off mechanism. Hydraulic line.