JPS6355804U

JPS6355804U -

Info

Publication number: JPS6355804U
Application number: JP15020386U
Authority: JP
Priority date: 1986-09-30
Filing date: 1986-09-30
Publication date: 1988-04-14

Description

[Brief explanation of the drawing]

図面は本考案の一実施例を示すもので、第１図
は農用トラクタの側面図、第２図はその農用トラ
クタの油圧装置におけるユニツト化された油圧ポ
ンプ及び制御弁装置の平面図、第３図及び第４図
は第２図の―線及び―線断面図、第５図
は第２図の矢視図、第６図は第４図の―線
断面図、第７図は第３図の―線断面図、第８
図は第７図の―線断面図、第９図は制御弁装
置の縦断面図、第９Ａ図は第９図の第１チエツク
弁及び調圧弁周辺部の拡大図、第９Ｂ図は第９図
の絞り弁及び第２チエツク弁の周辺部の拡大図、
第１０図及び第１１図は第９図の―線及び
―線断面図である。３……エンジン、２１ｆ，２１ｒ……前，後部
昇降腕、２２ｆ，２２ｒ……前，後部油圧シリン
ダ、２５……油圧制御ユニツト、２６……油タン
ク、３３……油圧ポンプ、３４……制御弁装置、
３５……ケーシング、５５……切換弁、５６……
マニユアル弁、５７……絞り弁、５７ａ……弁部
、５８_１……チエツク弁、６９……油路、８５…
…バイパス孔。 The drawings show one embodiment of the present invention, in which Fig. 1 is a side view of an agricultural tractor, Fig. 2 is a plan view of a unitized hydraulic pump and control valve device in the hydraulic system of the agricultural tractor, and Fig. 3 is a plan view of a unitized hydraulic pump and control valve device in the hydraulic system of the agricultural tractor. Figures 4 and 4 are sectional views taken along lines - and - of Fig. 2, Fig. 5 is a view taken along the arrows in Fig. 2, Fig. 6 is a sectional view taken along - lines of Fig. 4, and Fig. 7 is a sectional view taken along lines - 3 of Fig. 2. - line sectional view, No. 8
The figure is a cross-sectional view taken along the line -- in Fig. 7, Fig. 9 is a vertical sectional view of the control valve device, Fig. 9A is an enlarged view of the first check valve and pressure regulating valve surrounding area in Fig. 9, and Fig. 9B is a cross-sectional view of the control valve device. An enlarged view of the surrounding parts of the throttle valve and second check valve shown in the figure,
10 and 11 are cross-sectional views taken along lines - and - in FIG. 9. 3... Engine, 21f, 21r... Front, rear lifting arm, 22f, 22r... Front, rear hydraulic cylinder, 25... Hydraulic control unit, 26... Oil tank, 33... Hydraulic pump, 34... Control valve device,
35...Casing, 55...Switching valve, 56...
Manual valve, 57... Throttle valve, 57a... Valve section, 58 ₁ ... Check valve, 69... Oil path, 85...
...Bypass hole.

Claims

[Scope of utility model registration request]

Hydraulic cylinder attached to a work vehicle to raise and lower the work equipment; Hydraulic pump; Oil tank; Stop position where the hydraulic oil discharged from the hydraulic pump is discharged into the oil tank, and a raised position where the hydraulic oil is supplied to the hydraulic cylinder. A manual valve configured to be able to shift to a lower position where the hydraulic oil supplied to the hydraulic cylinder is circulated to the oil tank; the valve portion is inserted into a throttle hole formed in the oil passage between the manual valve and the hydraulic cylinder. In a hydraulic system for a work vehicle equipped with a throttle valve, a bypass hole communicating between both ends of the throttle hole is formed in the throttle valve, and the bypass hole is configured to allow oil to flow in only one direction from the manual valve to the hydraulic cylinder. A hydraulic system for a work vehicle, characterized by a removable check valve that allows flow.