Negative pressure type booster device

Patent metadata

Field	Value
Publication number	US-10173656-B2
Application number	US-201415031979-A
Country	US
Kind code	B2
Filing date	Oct 24, 2014
Priority date	Oct 25, 2013
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A movable diaphragm of a negative pressure type booster device includes an annular rubber diaphragm and an annular metal plate. The diaphragm is airtightly pinched by the housing at an annular outer peripheral bead portion formed at an outer peripheral edge of the diaphragm, and airtightly secured to an outer peripheral portion of a valve body, together with an inner peripheral portion of the plate, at an annular inner peripheral bead portion formed at an inner peripheral edge of the diaphragm. Between the outer peripheral bead portion and the inner peripheral bead portion, there are formed a folded portion having a curved portion toward the front and continuous with the outer peripheral bead portion at an outer peripheral area, and an annular portion continuous with an inner peripheral area of the folded portion and with the inner peripheral bead portion.

First claim

The invention claimed is:

1. A negative pressure type booster device comprising:
a housing,
a movable diaphragm partitioning an interior of the housing into a forward negative pressure chamber and a rear pressure conversion chamber,
a valve body connected to the movable diaphragm, the valve body including a shaft hole,
a plunger configured to reciprocate in an axial direction with reference to the valve body and movable integrally with an input member,
a valve mechanism movable integrally with the plunger, the valve mechanism including a negative pressure valve performing communication/cutoff between the negative pressure chamber and the pressure conversion chamber depending on reciprocal movement of the plunger with reference to the valve body and an air valve performing communication/cutoff between the pressure conversion chamber and atmospheric air, the negative pressure valve and the air valve being positioned in the shaft hole,
a reaction member having a rear surface engageable with a front end portion of the plunger and a front end portion of the valve body, and
an output member having a rear end portion engaged with a front surface of the reaction member and being configured to move in the axial direction with reference to the valve body, the movable diaphragm and the valve body being operable upon operation of the input member in a forward direction to move the output member in the forward direction, wherein
the movable diaphragm includes an annular rubber diaphragm and an annular metal plate disposed in front thereof, the rubber diaphragm is airtightly held at an annular outer peripheral bead portion formed on an outer peripheral edge of the diaphragm in the housing, and is airtightly fixed on an outer peripheral portion of the valve body together with an inner peripheral portion of the metal plate on an annular inner peripheral bead portion formed on an inner peripheral edge of the diaphragm, between the outer peripheral bead portion and the inner peripheral bead portion, a folded portion having a curved portion on the front side and connected to the outer peripheral bead portion at an outer peripheral portion is formed, an annular portion connected to an inner peripheral portion of the folded portion and the inner peripheral bead portion is formed, and the rubber diaphragm is molded in a condition in which a shape of the folded portion is a form which the folded portion also takes in an active state of the valve body.

2. The negative pressure type booster device according to claim 1 , wherein when a condition of the folded portion in an inactive state of the valve body is a 0%-active condition and a condition of the folded portion in a full-stroke active state of the valve body is a 100%-active condition, a molded shape of the rubber diaphragm is a shape in any one of the active conditions including the 10%-active condition to the 100%-active condition of the folded portion.

3. The negative pressure type booster device according to claim 1 , wherein
when a condition of the folded portion in an inactive state of the valve body is a 0%-active condition and a condition of the folded portion in a full-stroke active state of the valve body is a 100%-active condition, a molded shape of the rubber diaphragm is a shape in any one of the active conditions including the 10%-active condition to the 70%-active condition of the folded portion.

4. The negative pressure type booster device according to claim 1 , wherein in the rubber diaphragm, the outer peripheral bead portion is mounted in the housing when the folded portion has a shape in a molding condition.

Assignees

• Advics Co Ltd

Inventors

• Inoue Yoji

Classifications

• B60T13/569 Primary

  characterised by piston details, e.g. construction, mounting of diaphragm · CPC title