JPS60151966U

JPS60151966U - Hydraulic circuit of upper swing type construction machine

Info

Publication number: JPS60151966U
Application number: JP3997084U
Authority: JP
Inventors: 交堂辻
Original assignee: 株式会社小松製作所
Priority date: 1984-03-22
Filing date: 1984-03-22
Publication date: 1985-10-09

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 drawings]

第１図は従来例を示す油圧回路図、第２図は上部旋回式
建設機械の一例を示す側面図、第３図は本考案の実施例
を示す油圧回路図である。１は主油圧ポンプ、３は旋回方向切換弁、４はブーム方
向切換弁、６はブームシリンダ、１０は旋回パイロット
操作弁、１１はブームパイロット操作弁、１６は旋回圧
力保証弁、１６ａは連通位置、１６ｂは絞り連通位置、
１８は旋回パイロットシャトル弁、１８ａは分岐ポート
。FIG. 1 is a hydraulic circuit diagram showing a conventional example, FIG. 2 is a side view showing an example of an upper swing type construction machine, and FIG. 3 is a hydraulic circuit diagram showing an embodiment of the present invention. 1 is the main hydraulic pump, 3 is the swing direction switching valve, 4 is the boom direction switching valve, 6 is the boom cylinder, 10 is the swing pilot operating valve, 11 is the boom pilot operating valve, 16 is the swing pressure guarantee valve, 16a is the communication position , 16b is the aperture communication position;
18 is a swing pilot shuttle valve, and 18a is a branch port.

Claims

[Scope of utility model registration request]

The swing motor 13 and the boom cylinder 6 are connected in parallel to the main hydraulic pump 1 via the swing direction switching valve 3 and the boom direction switching valve 4, which are controlled by pilot pressure, respectively, and the two-way switching valves 3 and 4 are connected in parallel to each other. A swing pilot operating valve 10 and a boom pilot operating valve 1 are provided in the pilot pressure acting section, respectively.
In the hydraulic circuit of an upper swing type construction machine to which one pilot circuit is connected, a swing pilot shuttle valve 18 having a branch port 18a is provided between each pilot pressure acting part of the swing direction switching valve 3 and the swing pilot operation valve 10. In addition, a swing pressure guarantee valve 16, which has a communication position 16a and a throttle communication position 16b and is switched and operated by pilot pressure, is installed in the circuit for raising the boom cylinder 6. The pilot pressure acting part for switching to the communication position 1'6a side of the guarantee valve 16 is connected to the raised side chamber of the boom cylinder 6, and the pilot pressure acting part for switching to the throttle communication position 16b side is connected to the above-mentioned swing pilot. A hydraulic circuit for an upper swing type construction machine, characterized in that it is connected to a branch port 18a of a shuttle valve 18.