JPH01120562U

JPH01120562U -

Info

Publication number: JPH01120562U
Application number: JP1294788U
Authority: JP
Priority date: 1988-02-01
Filing date: 1988-02-01
Publication date: 1989-08-15
Anticipated expiration: 2003-02-01
Also published as: JPH0649634Y2

Description

[Brief explanation of the drawing]

第１図は請求項第１項にかかるドーザ切換装置
用油圧回路図、第２図は請求項第２項にかかるド
ーザ切換装置用回路図、第３図は請求項第３項に
かかるドーザ切換装置用回路図、第４図はドーザ
アタツチメントを装備した油圧シヨベルの側面図
、第５図は従来技術油圧回路図である。１……ドーザアタツチメント、４……ドーザシ
リンダ、７……第１ポンプ、８……第２ポンプ、
９……パイロツトポンプ、１０，１０′……ドー
ザ弁、１１……第３ポンプ、１４，２２，３３…
…ドーザ切換装置、１５……分流用切換弁、１６
，１２，２５……リリーフ弁、２３……分流用パ
イロツト切換弁、２４……電磁開閉弁、２６，３
４……電気回路、２７……リミツトスイツチ、３
５……スイツチ。 1 is a hydraulic circuit diagram for a dozer switching device according to claim 1, FIG. 2 is a circuit diagram for a dozer switching device according to claim 2, and FIG. 3 is a hydraulic circuit diagram for a dozer switching device according to claim 3. FIG. 4 is a side view of a hydraulic excavator equipped with a dozer attachment, and FIG. 5 is a prior art hydraulic circuit diagram. 1... Dozer attachment, 4... Dozer cylinder, 7... First pump, 8... Second pump,
9... Pilot pump, 10, 10'... Dozer valve, 11... Third pump, 14, 22, 33...
...Dozer switching device, 15... Diversion switching valve, 16
, 12, 25... Relief valve, 23... Diversion pilot switching valve, 24... Solenoid on-off valve, 26, 3
4... Electric circuit, 27... Limit switch, 3
5...Switch.

Claims

[Scope of Claim for Utility Model Registration] (1) Various hydraulic actuators of a hydraulic excavator equipped with a dozer attachment are divided into two groups A and B, and a first and second pump are provided for each group A and B, respectively. In the hydraulic circuit configured to supply pressure oil discharged from the pump, a diversion switching valve is provided in the oil passage communicating the first and second pumps with switching valves for various hydraulic actuators, and the diversion switching valve and The dozer cylinder is connected to the dozer cylinder via a dozer valve, and the switching operations of the dozer valve and the diverting valve are set so that they can be switched in conjunction with each other. What is claimed is: 1. A dozer switching device characterized in that the dozer switching device is configured to be capable of supplying parts. (2) A pilot switching valve for diversion is provided in the oil passage that communicates the first and second pumps mounted on the hydraulic excavator with switching valves for various hydraulic actuators, and the pilot switching valve for diversion and the dozer cylinder are connected to a dozer valve. A limit switch is provided near the operating lever of the dozer valve, and the limit switch is set to turn on in conjunction with the switching operation of the dozer valve. An electromagnetic on-off valve is interposed in the oil passage communicating with the pilot pressure receiving part, and when the dozer valve is switched, the electromagnetic on-off valve and the diverting pilot switching valve can be switched by turning on the limit switch. A dozer switching device according to claim 1. (3) A pilot switching valve for diversion is provided in the oil passage that communicates the first and second pumps mounted on the hydraulic excavator with switching valves for various hydraulic actuators, and the pilot switching valve for diversion and the dozer cylinder are connected to a dozer valve. On the other hand, an electromagnetic on-off valve is interposed in the oil passage that communicates the pilot pump and the pilot pressure receiving part of the pilot switching valve for diverting flow, and the electromagnetic on-off valve can be switched by a manually operated switch. A dozer switching device characterized in that it is configured to be set to