JPH02145005U

JPH02145005U -

Info

Publication number: JPH02145005U
Application number: JP5316089U
Authority: JP
Priority date: 1989-05-08
Filing date: 1989-05-08
Publication date: 1990-12-10

Description

[Brief explanation of drawings]

第１図及び第２図はそれぞれ本考案の実施例に
係る油圧制御装置の断面図、第３図乃至第５図は
それぞれ同作用説明図、第６図は同油圧回路図、
第７図は同農用トラクタと作業機との側面図、第
８図は他の実施例に係る作用説明図、第９図は農
用トラクタの左右水平制御のための説明図、第１
０図は農用トラクタの前後バランス制御のための
説明図、第１１図は従来例に係る油圧制御弁の作
用説明図である。２１……弁本体、３３……第１流路、３３ａ…
…上流第１流路、３３ｂ……下流第１流路、３４
……スプール軸、３６……第２流路、３７……圧
油連通口、３８……径大部、４９……リターン流
路、５１……傾斜面。 1 and 2 are sectional views of a hydraulic control device according to an embodiment of the present invention, FIGS. 3 to 5 are explanatory diagrams of the same operation, and FIG. 6 is a hydraulic circuit diagram of the same,
FIG. 7 is a side view of the same agricultural tractor and working machine, FIG. 8 is an explanatory diagram of the operation according to another embodiment, FIG. 9 is an explanatory diagram for horizontal horizontal control of the agricultural tractor,
FIG. 0 is an explanatory diagram for controlling the longitudinal balance of an agricultural tractor, and FIG. 11 is an explanatory diagram of the operation of a conventional hydraulic control valve. 21... Valve body, 33... First flow path, 33a...
...Upstream first flow path, 33b...Downstream first flow path, 34
... Spool shaft, 36 ... Second flow path, 37 ... Pressure oil communication port, 38 ... Large diameter portion, 49 ... Return flow path, 51 ... Inclined surface.

Claims

[Scope of utility model registration request]

A spool shaft 34 is inserted into the first flow path 33 of the valve body 21 so as to be movable in the axial direction, and a second flow path 36 communicating with the first flow path 33 and transmitting hydraulic pressure is formed. In the hydraulic control valve device in which a large diameter portion 38 is formed on the outer periphery of the spool shaft 34 to open and close the pressure oil communication port 37 from the first flow path 33 to the second flow path 36 by moving the spool shaft 34 in the axial direction. By making the axial length of the large diameter portion 38 shorter than the axial length of the pressure oil communication port 37, the spool shaft 34 is connected to the upstream first flow path 33a upstream of the large diameter portion 38 and the downstream Side downstream first flow path 3
3b and 3b to the second flow path 36, and a neutral state in which the first upstream flow path 33a is connected to the second flow path 36 and the space between the first downstream flow path 33b and the second flow path 36 is closed. The hydraulic pressure transmission state and the first upstream flow path 33
The pressure oil from the upstream first flow path 33a is returned to the tank in the neutral state, and the pressure oil is returned to the tank in the neutral state. The flow path 49 is communicated with at least one of the axially upstream peripheral edge of the large diameter portion 38 and the axially upstream peripheral edge of the pressure oil communication port 37 so that the axial distance between the two peripheral edges is increased. A hydraulic control valve device characterized by having an inclined surface 51 inclined with respect to the axial direction.