JPS6414260U

JPS6414260U -

Info

Publication number: JPS6414260U
Application number: JP10972787U
Authority: JP
Priority date: 1987-07-16
Filing date: 1987-07-16
Publication date: 1989-01-25

Description

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はこの考案にかかる第１実施例油圧回路
図、第２図は第１図のＣ部詳細図、第３図はこの
考案にかかる第２実施例油圧回路図、第４図は従
来技術油圧回路図である。１……ブーム第１弁、２，２９，４０……ブー
ム第２弁、３……ブームシリンダ、４……ブーム
用リモコン弁、５……第１ポンプ、６……第２ポ
ンプ、９……ブーム、１２……パイロツト弁、３
０，４３……電磁弁、３２……リミツトスイツチ
。 Fig. 1 is a hydraulic circuit diagram of a first embodiment of this invention, Fig. 2 is a detailed view of section C in Fig. 1, Fig. 3 is a hydraulic circuit diagram of a second embodiment of this invention, and Fig. 4 is a conventional hydraulic circuit diagram. Technical hydraulic circuit diagram. 1... Boom first valve, 2, 29, 40... Boom second valve, 3... Boom cylinder, 4... Boom remote control valve, 5... First pump, 6... Second pump, 9... ...Boom, 12...Pilot valve, 3
0,43...Solenoid valve, 32...Limit switch.

Claims

【実用新案登録請求の範囲】[Scope of utility model registration request]

油圧シヨベルに装備した各種油圧アクチユエー
タ制御用切換弁を２個のグループＡ，Ｂに分け、
そのグループＡ内にブーム第１弁を、かつ、グル
ープＢ内にブーム第２弁を設け、また、グループ
Ａ、グループＢのそれぞれ圧油供給源として第１
ポンプ、第２ポンプを配置した油圧回路において
、ブーム用リモコン弁のブーム上昇用パイロツト
弁と、ブーム第１弁またはブーム第２弁のいずれ
か一方のブーム上昇用パイロツト圧受圧部とを連
通するパイロツト油路に油路開閉用電磁弁を設け
、一方、油圧シヨベル用上部旋回体のメインフレ
ーム付近にリミツトスイツチを設け、ブーム最高
上昇位置手前にてブームフート部の一部位を上記
リミツトスイツチの接触子に当接可能とするとと
もに、上記リミツトスイツチと電磁弁とを連結し
て構成したことを特徴とする油圧シヨベルの油圧
回路。 The switching valves for controlling various hydraulic actuators installed on the hydraulic excavator are divided into two groups A and B.
A first boom valve is provided in group A, a second boom valve is provided in group B, and a first boom valve is provided as a pressure oil supply source for each of group A and group B.
In a hydraulic circuit in which the pump and the second pump are arranged, a pilot valve that communicates between the boom lifting pilot valve of the boom remote control valve and the boom lifting pilot pressure receiving part of either the boom first valve or the boom second valve. A solenoid valve for opening and closing the oil passage is installed in the oil passage, and a limit switch is installed near the main frame of the upper revolving structure for the hydraulic excavator, and a part of the boom foot is brought into contact with the contact of the limit switch before the boom reaches its highest raised position. A hydraulic circuit for a hydraulic excavator, characterized in that the limit switch and the solenoid valve are connected to each other.