JPH0475759U - - Google Patents

Description

[Brief explanation of the drawing]

The figure is a sectional view showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Tandem brake booster, 3... Shell, 3b... Cylindrical part, 4... Master cylinder, 5
...Housing, 6...Piston rod, 7...
Output shaft, 8... Seal member, 8a... Radial portion, 8b... Axial portion, 18... Retainer.

Claims (1)

[Claims for Utility Model Registration] (1) A piston rod is formed on the front shaft of the shell toward the rear, through which the piston rod of the master cylinder passes, and into which the rear end of the master cylinder housing is fitted. A brake booster comprising a cylindrical portion and a sealing member that maintains airtightness between the cylindrical portion of the shell and the piston rod of the master cylinder, the brake booster being fitted onto the tip of the cylindrical portion of the shell and A retainer is provided through which the piston rod of the master cylinder passes, and the seal member is formed of a cylindrical axial portion and a radial portion formed by bending the rear end of the axial portion radially inward. The radial inner circumference of the seal member is brought into close contact with the outer circumference of the piston rod of the master cylinder, and the outer circumference of the axial portion of the seal member is brought into close contact with the inner circumference of the cylindrical portion of the shell. A brake booster characterized by: (2) A cylindrical part formed toward the rear side on the front shaft part of the shell, through which the output shaft passes, and into which the rear end of the master cylinder housing is fitted, and the cylindrical part of the shell. and a seal member that maintains airtightness between the shell and the output shaft, the retainer being fitted onto the tip of the cylindrical portion of the shell and through which the output shaft passes, and the seal member is composed of a cylindrical axial part and a radial part formed by bending the rear end of the axial part radially inward, and the inner peripheral part of the radial part of the seal member is A brake booster, characterized in that the seal member is brought into close contact with the outer peripheral part of the output shaft, and further, the outer peripheral surface of the axial part of the seal member is brought into close contact with the inner peripheral surface of the cylindrical part of the shell. (3) forming an annular protrusion bulging in the radial direction at the front end of the axial portion of the sealing member, and bringing the outer circumferential portion of the annular protrusion into close contact with the inner circumferential surface of the cylindrical portion of the shell; A sealing member that fits the inner peripheral part of the annular projection into the housing of the master cylinder, and forms a notch that penetrates in the axial direction in the inner peripheral part of the annular projection, and is located on the rear side of the annular projection. forming a plurality of protrusions on the inner circumferential surface of the axial portion of the seal member to maintain a gap between the inner circumferential surface of the axial portion of the seal member and the outer circumferential surface of the housing of the master cylinder; A utility model characterized in that a space defined by the rear end surface of the housing of the master cylinder and the seal member is communicated with outside air through a notch provided in the annular projection and the gap. A brake booster according to claim 1 or 2 of the registered claims.