JPS5974989U - Four-stage boom extension device - Google Patents

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

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

図面は本考案の実施例を示すもので、第１図は四段ブー
ムの断面図、第２図は油圧配管図である。 １、２．３．４は第１、第２、第３、第４ブーム、５．
６は第１、第２シリンダ、５ａ、　　ｆｉａはボトム室
、５ｂ、６ｂはロッド室、７，８は口］ンド、９．１０
はシーブ、１１．１２はロープ、１３ａ。 １４ａはボトム側通路、１３ｂ、１４ｂはロッド測道Ｌ
　１５ａ、　　１５ｂはカウンタバランス弁、１６は伸
縮切換弁、１７はポンプ、１８ａ。 １８ｂは配管。−The drawings show an embodiment of the present invention, and FIG. 1 is a sectional view of a four-stage boom, and FIG. 2 is a diagram of hydraulic piping. 1, 2.3.4 are the first, second, third, and fourth booms; 5.
6 is the first and second cylinders, 5a, fia is the bottom chamber, 5b and 6b are the rod chambers, 7 and 8 are the openings, 9.10
is sheave, 11.12 is rope, 13a. 14a is the bottom side passage, 13b and 14b are rod surveying paths L
15a, 15b are counter balance valves, 16 is a telescopic switching valve, 17 is a pump, and 18a. 18b is piping. −

Claims (1)

【実用新案登録請求の範囲】 第１、第２、第３、第４のブーム１．２．３゜４をテレ
スコピック状に伸縮可能に嵌挿し、また第１シリンダ部
を第２ブーム２に、ロッド７を第１ブーム１に連結し、
第２シリンダ６のシリンダ部を第３ブームに、ロッド８
を第２ブーム２に連結し、さらに第３ブーム３に枢着し
た収縮シーブ９及び伸長ブーム１０に一端を第２ブーム
２に、他端を第４ブーム４に連結した収縮および伸張ロ
ープ１１．１２を巻掛けてなる四段ブーム伸縮装置にお
いて、第１、第２シリンダ５．６のロッド７．８のそれ
ぞれに、ボトム室５ａ、５ａに連通ずるボトム側通路１
３ａ、１４ａと、ロッド室５ｂ。 ６ｂに連通ずるロッド側通路１３ｂ、１４ｂを設け、第
１シリンダ５のロッド６に設けた上記両通路１３ａ、　
　１３ｂをカウンタバランス弁１５ａ。 １５ｂおよび伸縮切換弁１６を介してポンプ１７に接続
し、第２シリンダ６のロッド７に設けたボトム側通路１
４ａを第１シリンダ５のボトム室５ａに、ロッド側通路
１４ｂをロッド室５ｂにそれぞれ配管１８ａ、１８ｂを
介して接続し、上記第１、第２シリンダ５．６の両ボト
ム室５ａ、５ａの受圧面積Ｓ□、Ｓ２をＳｌ＞Ｓ２とし
たことを特徴とする四段ブーム伸縮装置。[Claims for Utility Model Registration] The first, second, third, and fourth booms 1.2.3°4 are telescopically telescopically inserted and inserted, and the first cylinder portion is inserted into the second boom 2, Connecting the rod 7 to the first boom 1,
The cylinder part of the second cylinder 6 is connected to the third boom, and the rod 8
is connected to the second boom 2, and further connected to the retractable sheave 9 and the extendable boom 10, which are pivotally connected to the third boom 3. A retractable and extensible rope 11. is connected to the second boom 2 at one end and to the fourth boom 4 at the other end. In the four-stage boom telescoping device, each of the rods 7.8 of the first and second cylinders 5.6 has a bottom side passage 1 communicating with the bottom chambers 5a, 5a.
3a, 14a, and the rod chamber 5b. rod-side passages 13b and 14b communicating with the rod 6b, and both passages 13a provided in the rod 6 of the first cylinder 5;
13b is a counter balance valve 15a. 15b and the bottom side passage 1 connected to the pump 17 via the telescopic switching valve 16 and provided in the rod 7 of the second cylinder 6.
4a is connected to the bottom chamber 5a of the first cylinder 5, and the rod side passage 14b is connected to the rod chamber 5b via piping 18a, 18b, respectively. A four-stage boom extension and retraction device characterized in that the pressure receiving area S□, S2 satisfies Sl>S2.