JPH0262175U

JPH0262175U -

Info

Publication number: JPH0262175U
Application number: JP14149988U
Authority: JP
Priority date: 1988-10-28
Filing date: 1988-10-28
Publication date: 1990-05-09

Description

[Brief explanation of the drawing]

第１図は本考案におけるリリーフ弁の断面図、
第２図は同実施例のダンピング機構の要部断面図
、第３図は同ダンピング機構の作用説明図、第４
図は別の実施例のダンピング機構の要部断面図、
第５図は同ダンピング機構の作用説明図、第６図
はダンピング室がない場合に段付ピストンがスト
ロークエンドに達した瞬間に段付ピストンに作用
する液圧の変動状態の説明図、第７図は同リリー
フ圧力の変動状態の説明図、第８図はダンピング
室を有する場合にリリーフ弁始動時における段付
ピストンに作用する液圧力と時間との関係の説明
図、第９図は同リリーフ圧力と時間との関係の説
明図である。１……ケーシング本体、２……流入孔、３……
シート、９……プランジヤ、１０……貫通孔、１
１……絞り部、１２……段付ピストン、１６……
液室、１８……ダンピング室、１８ａ……連通路
、１９……第１のばね（ばね）、２４……連通孔
、２５……戻し流路、２９……電磁比例開閉弁（
開閉弁）。 Figure 1 is a cross-sectional view of the relief valve according to the present invention.
Fig. 2 is a sectional view of the main parts of the damping mechanism of the same embodiment, Fig. 3 is an explanatory diagram of the operation of the damping mechanism, and Fig. 4
The figure is a sectional view of a main part of a damping mechanism of another embodiment,
Fig. 5 is an explanatory diagram of the operation of the same damping mechanism, Fig. 6 is an explanatory diagram of the fluctuating state of the hydraulic pressure acting on the stepped piston at the moment when the stepped piston reaches the stroke end when there is no damping chamber, and Fig. 7 The figure is an explanatory diagram of the fluctuation state of the relief pressure, Figure 8 is an explanatory diagram of the relationship between the hydraulic pressure acting on the stepped piston and time when the relief valve is started when the relief valve has a damping chamber, and Figure 9 is an explanatory diagram of the relationship between the relief pressure and time. FIG. 3 is an explanatory diagram of the relationship between pressure and time. 1...Casing body, 2...Inflow hole, 3...
Sheet, 9...Plunger, 10...Through hole, 1
1... Restricted portion, 12... Stepped piston, 16...
Liquid chamber, 18... Damping chamber, 18a... Communication path, 19... First spring (spring), 24... Communication hole, 25... Return flow path, 29... Electromagnetic proportional opening/closing valve (
on-off valve).

Claims

[Scope of utility model registration request]

A cylindrical casing with an annular sheet forming an inflow hole for pressure liquid on the inflow side fixed at one end and closed at the other end, and one end formed with a large diameter so as to be slidable on the inner periphery of the one end of the casing. a cylindrical step that is slidably fitted between the plunger to be fitted and the inner periphery of the other end of the casing and the outer periphery of the other end of the plunger to form a liquid chamber between the other end of the casing; and a communication passage that communicates the liquid chamber with an annular damping chamber formed by a stepped portion on the outer circumference of the stepped piston and a stepped portion on the inner circumference of the casing. A through hole is formed along the direction, and an arbitrary part of the through hole is formed into a fine hole to form a constricted part, a spring is interposed between one end of the stepped piston and one end of the plunger, and the A communication hole is formed in the casing to communicate the damping chamber with the other end of an external return passage whose one end is open to the atmosphere, and an on-off valve whose opening degree can be arbitrarily varied is interposed in the return passage. A relief valve characterized by: