JPH0262176U

JPH0262176U -

Info

Publication number: JPH0262176U
Application number: JP14150088U
Authority: JP
Priority date: 1988-10-28
Filing date: 1988-10-28
Publication date: 1990-05-09
Anticipated expiration: 2003-10-28
Also published as: JPH0717895Y2

Description

[Brief explanation of drawings]

第１図は本考案の一実施例におけるリリーフ弁
の断面図、第２図および第３図は各々同リリーフ
弁のダンピング動作の説明図、第４図は同リリー
フ弁の寸法関係の説明図、第５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６図は同リリーフ圧力の変動状
態の説明図、第７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８図は同
リリーフ圧力と時間との関係の説明図、第９図は
本考案の別の実施例におけるリリーフ弁の断面図
である。１……ケーシング、２……流入孔、３……シー
ト、９……プランジヤ、１０……貫通孔、１１…
…絞り部、１２……段付ピストン、１５……連通
孔、１６……ポペツト、１７……突出部、２０…
…第１のばね、２２……第３のばね、４１……ケ
ーシング、４２……流入孔、４３……シート、４
９……プランジヤ、５０……貫通孔、５１……絞
り部、５２……段付ピストン、５３……スリーブ
、５４……液室、６０……第１のばね、６１……
第２のばね、６２……第３のばね。 FIG. 1 is a sectional view of a relief valve according to an embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams of the damping operation of the relief valve, and FIG. 4 is an explanatory diagram of the dimensional relationship of the relief valve. Fig. 5 is an explanatory diagram of the fluctuation 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. 6 is an explanatory diagram of the fluctuation state of the relief pressure. Fig. 7 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 damping chamber is provided, Fig. 8 is an explanatory diagram of the relationship between the relief pressure and time, and Fig. 9 The figure is a sectional view of a relief valve in another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Casing, 2...Inflow hole, 3...Seat, 9...Plunger, 10...Through hole, 11...
...Constricted portion, 12...Stepped piston, 15...Communication hole, 16...Poppet, 17...Protrusion, 20...
...First spring, 22...Third spring, 41...Casing, 42...Inflow hole, 43...Seat, 4
9... Plunger, 50... Through hole, 51... Restricted portion, 52... Stepped piston, 53... Sleeve, 54... Liquid chamber, 60... First spring, 61...
Second spring, 62...Third spring.

Claims

[Claims for Utility Model Registration] 1. A cylindrical casing having an annular sheet fixed to one end and closed at the other end, forming an inflow hole for pressure liquid on the inflow side, and the casing having a large diameter at one end. a plunger that is slidably fitted to the inner periphery of one end and whose other end is slidably fitted to the inner periphery of a cylindrical sleeve; and between the inner periphery of the other end of the casing and the outer periphery of the sleeve; a cylindrical stepped piston that is slidably fitted to the sleeve and forms a liquid chamber between the sleeve and the other end of the casing; and a stepped piston that is slidably fitted to the inner periphery of the sleeve and has a tapered protrusion at the lower end. A poppet with a protruding portion is provided, a through hole is formed in the plunger along the axial direction, and an arbitrary part of the through hole is made into a fine hole to form a constricted portion, and the other end of the casing and the A first spring is interposed between the poppet and the poppet so that the protrusion of the poppet fits into the through hole of the plunger in a fluid-tight manner, and a second spring is interposed between one end of the sleeve and one end of the plunger. a third spring is interposed between one end of the stepped piston and one end of the plunger to bring one end of the stepped piston into fluid-tight contact with the seat; The plunger is brought into contact with the other end of the casing, and the through hole of the plunger and the liquid chamber communicate with each other via a communication hole formed in the sleeve, and the communication path is opened and closed by a protrusion of the poppet. A relief valve characterized by: 2. 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 plunger that is fitted into the rod and whose other end is slidably fitted to the outer periphery of one end of the rod; a cylindrical sleeve that is slidably fitted to the outer periphery of the other end of the rod; and the casing. A cylindrical stepped piston is provided between the inner periphery of the other end and the outer periphery of the sleeve so as to be slidably fitted to form a liquid chamber between the inner periphery of the sleeve and the other end of the casing. A through hole is formed along the direction, and an arbitrary part of the through hole is made a fine hole to form a constricted part, and a first spring is interposed between one end of the rod and one end of the plunger. One end of the plunger is brought into liquid-tight contact with the sheet, a second spring is interposed between one end of the sleeve and the plunger, and the other end of the sleeve is brought into contact with the other end of the casing in a fluid-tight manner. A third spring is interposed between one end of the stepped piston and the plunger, and the other end of the stepped piston is brought into contact with the other end of the casing, so that the liquid is connected to the through hole of the plunger. A relief valve characterized in that the chamber communicates with the chamber via the rod, and the communication path is opened and closed by the sleeve.