JPH0223268U

JPH0223268U -

Info

Publication number: JPH0223268U
Application number: JP10191988U
Authority: JP
Priority date: 1988-07-29
Filing date: 1988-07-29
Publication date: 1990-02-15
Anticipated expiration: 2003-07-29
Also published as: JPH0635848Y2

Description

[Brief explanation of drawings]

第１図は本考案に従つた負圧式倍力装置の一実
施例を示す断面図、第２図は本考案の要部を示す
ピストンボデイの斜視図である。１０…負圧式倍力装置、１１…ボデイ、１４…
パワーピストン、１５…ダイアフラム、１５ａ…
内周ビード部、１６…定圧室、１７…変圧室、１
８…ピストンボデイ、１８ｃ…変圧室側に面する
面、１８ｄ…スリツト、１８ｆ…溝、１８ｇ…外
周部分、１８ｈ…ランド部、１８ｉ…環状溝、１
８ｊ…リブ、１９…プレツシヤプレート、１９ａ
…筒状部、１９ｂ…係止鉤部、２３…制御弁。 FIG. 1 is a sectional view showing an embodiment of a negative pressure booster according to the present invention, and FIG. 2 is a perspective view of a piston body showing the main parts of the present invention. 10... Negative pressure booster, 11... Body, 14...
Power piston, 15...Diaphragm, 15a...
Inner peripheral bead portion, 16... constant pressure chamber, 17... variable pressure chamber, 1
8... Piston body, 18c... Surface facing the variable pressure chamber side, 18d... Slit, 18f... Groove, 18g... Outer circumferential portion, 18h... Land portion, 18i... Annular groove, 1
8j...rib, 19...pressure plate, 19a
...Cylindrical part, 19b...Latching hook part, 23...Control valve.

Claims

[Claims for Utility Model Registration] (1) A power piston that divides the inside of a body into a constant pressure chamber and a variable pressure chamber together with a diaphragm has a control valve that controls the pressure difference between the constant pressure chamber and the variable pressure chamber. Movement of the piston body toward the constant pressure chamber is restricted by contact between a built-in piston body, a surface of the piston body that is fitted into the piston body and faces toward the variable pressure chamber, and an annular inner circumferential portion of the piston body. In the negative pressure booster, the pressure plate is formed on the outer periphery of the piston body, and the thick inner periphery of the diaphragm is fitted airtightly by its own elasticity. The groove is arranged closer to the variable pressure chamber than the inner circumferential portion of the pressure plate, and the inner circumferential portion of the pressure plate contacts the piston body from the surface of the piston body facing the variable pressure chamber. A negative pressure booster characterized in that a substantially annular groove is formed on the variable pressure chamber side such that a land portion is formed between the groove and the groove. (2) In order to restrict the movement of the pressure plate toward the variable pressure chamber with respect to the piston body, a locking hook portion that comes into contact with a surface of the piston body facing toward the constant pressure chamber is attached to the pressure plate. an axial slit in the piston body through which the locking hook can pass, and an annular groove at the same position on the circumference as the slit; 2. The negative pressure booster according to claim 1, further comprising a rib that connects the slit and the land portion on the same plane.