JPS6382881U

JPS6382881U -

Info

Publication number: JPS6382881U
Application number: JP17656086U
Authority: JP
Priority date: 1986-11-17
Filing date: 1986-11-17
Publication date: 1988-05-31
Anticipated expiration: 2001-11-17
Also published as: JPH054629Y2

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
ンプおよび制御弁装置の平面図、第３図および第
４図は第２図の―線および―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図の一部の
拡大図、第１０図および第１１図は第９図の―
線および―線断面図、第１２図は油圧
系の油圧回路図である。Ａ……中立位置、Ｂ……上昇制御位置、Ｃ……
下降制御位置、Ｌ……制御油路、２２ｆ，２２ｒ
……前、後部油圧シリンダ、２６……油タンク、
３３……油圧ポンプ、５１……吐出ポート、５６
……マニユアル弁、５８……チエツク弁、１１５
……開弁棒、１２７……付勢手段としての引張り
ばね。 The drawings show an 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. The figure and FIG. 4 are cross-sectional views taken along lines - and - of FIG.
Fig. 5 is a view taken along the arrow in Fig. 2, Fig. 6 is a sectional view taken along the - line in Fig. 4, Fig. 7 is a sectional view taken along the - line in Fig. 3, and Fig. 8 is a 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 a part of FIG. 9, and FIGS. 10 and 11 are views of FIG. 9.
12 is a hydraulic circuit diagram of the hydraulic system. A... Neutral position, B... Lift control position, C...
Lowering control position, L...Control oil path, 22f, 22r
...Front and rear hydraulic cylinders, 26...Oil tank,
33...Hydraulic pump, 51...Discharge port, 56
...Manual valve, 58...Check valve, 115
...Valve opening rod, 127...Tension spring as biasing means.

Claims

[Scope of utility model registration request]

a hydraulic pump; a hydraulic cylinder to which hydraulic pressure is transmitted to raise a working machine, and a hydraulic cylinder to which hydraulic pressure is released to lower the working machine; interposed in a control oil path between a discharge port of the hydraulic pump and the hydraulic cylinder; a check valve that prevents release of hydraulic pressure from the hydraulic cylinder; a manual valve interposed in the control oil passage between the check valve and the discharge port; and a manual valve that operates in conjunction with the manual valve to force the check valve. and a valve opening rod that opens automatically; the manual valve has a neutral position in which the check valve is communicated with the oil tank, and an upward control in which the manual valve is shifted to one side from the neutral position and communicates the check valve with the discharge port. and a lower control position in which the check valve is communicated with the oil tank by being shifted from the neutral position to the other position, and the check valve is opened by the valve opening rod. A hydraulic system for a work vehicle, characterized in that the manual valve is provided with a biasing means for biasing the manual valve from the neutral position to the descending control position.