Jidosha Kiki Co., Ltd.

Calsonic Kansei Corporation

Haruo Suzuki

Kohei Mori

Atushi Satoh

Yasuo Tsuyuki

Hidefumi Inoue

Hideki Sunaga

Tohru Satoh

Hiroya Gotoh

Junichi Ohki

Satoru Satoh

Norio Fujii

Yuuzou Shimamura

Yuuji Daimon

Kazunori Endoh

Air in a thermally insulated space, which has been expanded by heat resulting from heating treatment for curing a thermosetting potting material, is prevented from entering the potting material. A casing has a partition wall that partitions an opening into a heat-generating-electronic-component placement section, where a heat generating electronic component is placed, and an adjacent section that is adjacent to the heat-generating-electronic-component placement section, when a heat releasing member is fixed to the opening. The heat-generating-electronic-component placement section is filled with a thermosetting potting material for moisture prevention up to a height which allows at least the heat generating electronic component to be buried in the potting material. The adjacent section has in the casing a communicating portion that communicates with a position which is apart from the heat-generating-electronic-component placement section filled with the potting material.

Electronic unit

A negative brake booster having a power piston 8 with a piston unit 8a extending in a radial direction, a cylinder unit 8b provided at a backward position in an axial direction and airtightly and slidably supported on a center plate 4. A front diaphragm 12 is provided between the outer peripheral edge of the piston unit 8a and the front shell 2. A rear power piston with a piston unit 9a extending in a radial direction and a cylinder unit 9b furnished at a backward position in an axial direction, and a rear diaphragm 12 are provided between the outer peripheral edge of the piston unit 9a and the front shell. Further, the rear power piston 9 is connected with the valve body 7 where the flange unit 8c of the front power piston 8 is squeezed between the stepped portion of the outer periphery of the valve body 7 by the rear power piston 9.

Negative pressure booster

An improvement of a variable pressure passage which is formed in a valve body of a booster, for example, a brake booster, is disclosed. The valve body which is disposed within a shell of the booster comprises a first and a second tubular member which are connected together. An axial space is defined by the outer peripheral surface of the first tubular member and the inner peripheral surface of the second tubular member when they are integrally connected together, and forms a variable pressure passage providing a communication between forwardly and rearwardly located, variable pressure chambers. This avoids the formation of an axial bore and a radial opening which are formed in a solid portion of a single member valve body, as occurs in the prior art, thus allowing the mechanical strength of the valve body to be improved.

Booster

In the negative pressure booster equipment according to the present invention, a valve plunger 17 and an input shaft 18 are incorporated in a single member. Also, the axial length of the guide 17a of the valve plunger in relation to the valve body 4 is set to such size as to allow the angle of the maximum inclination of the input shaft 18 during operation. Further, a retainer 27 to support a spring 33 of a control valve 22 is removably mounted on the input shaft 18 from the atmospheric air inlet of the valve body 4. Accordingly, in the case of valve disc 24 is to be replaced, valve disc 24 and other rubber products can be readily replaced by removing the retainer 27 without disassembling the valve plunger 17 or the input shaft 18 from the valve body 4. Because the valve plunger 17 and the input shaft 18 are incorporated, the caulking process for the members 17 and 18 are not required. Because the guide 17a of the valve plunger 17 requires the guding function in lesser degree than the conventional equipment, the overall length of the equipment can be shortened.

Brake booster

A seal unit for a brake booster such as of a tendem type including a centerplate disposed within a shell is disclosed. Annular seal means maintains a hermetic seal between the centerplate and a valve body. According to the invention, the annular seal means is formed with a passage which provides a communication between the inner and the outer periphery thereof. This allows a communication between the inner and the outer periphery of the annular seal means to be maintained by the passage formed therein in the event the opening of a constant pressure passage (or variable pressure passage) formed in the valve body is closed by the annular seal means. This allows a spacing between the annular seal means and a power piston or pistons mounted on the valve body to be reduced, contributing to reducing the overall length of the brake booster.

Seal unit for brake booster

A brake booster such as a tandem brake booster including a center plate disposed within a shell is disclosed. The center plate is connected to a valve body disposed within the shell by seal means in the form of a diaphragm, thus allowing the entire length of the valve body and hence of the brake booster to be reduced as compared with the prior art arrangement.

Brake booster with tubular guide member

The negative pressure booster equipment according to the present invention is provided with a variable orifice, by which the area of the air passage in the pathways other than one pathway, of two or more pathways communicating two or more variable pressure chambers with atmospheric air, is gradually decreased as the valve plunger moves forward, and it is gradually increased as the valve plunger moves backward in relation to the valve body. Consequently, the pathways other than one pathway are throttled by the variable orifice as the valve plunger moves forward. As the result, most of the air flowing through the control valve is intensively introduced into the variable pressure chamber communicating with the pathway, which is not throttled by the variable orifice, and the pressure in this variable pressure chamber is rapidly increased. As the result, the power pistons under the pressure in this variable pressure chamber is quickly operated, and the rising of the output of the negative pressure booster equipment occurs earlier.

Negative pressure booster equipment

A brake booster of triple type comprises a shell in which constant pressure and variable pressure chambers are formed. According to the invention, individual variable pressure chambers defined within the shell communicate with a valve mechanism through respective variable pressure passages having a minimum channel length. In this manner, hydraulic fluid contained within the respective variable pressure chambers which communicate with the associated variable pressure passages can be rapidly displaced through the valve mechanism, thus preventing an operational lag in terminating the brake action in a favorable manner.

Three chamber brake booster with variable pressure passages having a

A brake booster includes at least two pairs of constant pressure chambers and variable pressure chambers defined within a shell. A clearance is defined between a stepped end face of a valve body which is disposed within the shell and a power piston which is mounted on the valve body at a location rearward of the stepped end face. The clearance is utilized to provide a communication between the constant pressure chambers, thereby allowing a reduction in the axial size of the valve body.

A reaction mechanism for brake booster is disclosed. The end face of one end of an output shaft is formed with a recess in which a reaction disc is received. Part of the reaction disc and a valve body include projections extending into the other to establish a tight contact between part of the reaction disc and the valve body, which region is effective to achieve a hermetic seal in a reliable manner.

Reaction mechanism for brake booster

The invention relates to a locking arrangement for a key member used in a brake booster. A key member includes an arcuate portion which surrounds substantially one-half the perimeter of a valve body, and engaging recesses are formed at the opposite ends of the arcuate portion on the inner side. A retainer surrounds substantially one-half the perimeter of the valve body at a location opposite to the arcuate portion of the key member. The opposite ends of the retainer are formed with engaging pawls on the outer side for engaging with the engaging recesses under the resilience of the retainer. Accordingly, by merely assembling the key member and the retainer with the valve body, the engaging pawls of the retainer can be automatically engaged with the engaging recesses in the key member, thereby preventing the withdrawal of the retainer and the key member from the valve body.

A brake booster of tandem type comprises a pair of power pistons, a valve body internally housing a valve mechanism and a center body formed with a passage which communicates with a passage formed in the vlave body, all of which are integrally connected together, by holding them between a hub which is disposed through these members in alignment with their axes and a nut which is threadably engaged with the hub. An ear is formed on one of the outer peripheral surface of the hub and in an opening formed in the front power piston through which the hub extends while a recess is formed in the other for receiving the ear, thus allowing the hub and the front power piston to be positioned relative to each other by the engagement between the ear and the recess.

Brake booster of tandem type

A brake booster of tandem type includes a valve body, a rear power piston, a front power piston and a centerbody slidably extending through a centerplate which is centrally disposed within a shell, all of which are integrally connected together by utilizing a hub. An end of the hub located adjacent to the valve body is formed with an engaging portion which extends radially outward, while the shank portion of the valve body is formed with an axial groove which permits the engaging portion to pass there through and is also formed with an engaging recess circumferentially displaced from the axial groove and receiving the engaging portion. The engagement between the engaging portion and the engaging recess allows the hub to be assembled with the valve body while preventing the withdrawal of the hub forwardly from the valve body and also preventing the relative rotation therebetween, all with a greatly simplified construction.

A brake booster includes a plunger which defines a valve mechanism. A stop member is provided to prevent the withdrawal of the plunger, and structure is provided to prevent the disengagement of the stop member from a valve body. Specifically, the valve body is formed with a detent, and a retainer which supports the stop member is formed with a detent which is engageable with the detent on the valve body. The retainer is disposed externally of the stop member, and the detents on both the valve body and the retainer are effective, when engaged, to prevent the disengagement of the stop member from the valve body.

A tandem type brake power servo booster and toggle joint include a cylindrical member which has a first engaging portion for engaging a second engaging portion of a front power piston so that relative rotation between the cylindrical member and the front power piston can be prevented when a nut is tightened to secure the cylindrical member and the front power piston into position. In addition, a key member extends through a valve body and a hub of the cylindrical member to engage a valve plunger, and a surface of the key member which faces a push rod is spaced apart from the valve body to form a clearance between the valve body and the key member surface, thus providing the toggle joint with increased strength. In addition to the nut which serves as a stop, a second stop is formed on the hub so that the first and second stops integrally join the valve body and a center body of the cylindrical member with each other.

Growing community of inventors

Saitama, Japan

Haruo Suzuki