Cylinder mechanism

Abstract

A cylinder mechanism includes a housing, a piston slidably held in the housing for defining a fluid chamber for introducing a working fluid thereinto, and a plurality of disc springs for urging the piston toward the fluid chamber. At least two of the disc springs have respective bottom ends facing each other. A ring has an arcuate surface held against respective inner slanted surfaces of the at least two of the disc springs.

1 . A cylinder mechanism comprising:
 a housing;   a piston slidably held in said housing and defining a fluid chamber for introducing a working fluid thereinto;   a plurality of disc springs for urging said piston toward said fluid chamber, at least two of said disc springs having respective bottom ends facing each other; and   a circular member having an arcuate surface held against respective inner surfaces of said at least two of said disc springs.   
   
   
       2 . A cylinder mechanism according to  claim 1 , wherein said circular member is movable in an axial direction thereof and is prevented from moving in a direction perpendicular to said axial direction. 
   
   
       3 . A cylinder mechanism comprising:
 a housing;   a piston slidably held in said housing and defining a fluid chamber for introducing a working fluid thereinto;   a plurality of disc springs for urging said piston toward said fluid chamber, at least two of said disc springs having respective bottom ends facing each other; and   motion preventing means for preventing said at least two of said disc springs from moving in a direction perpendicular to an axial direction of said disc springs.   
   
   
       4 . A cylinder mechanism according to  claim 1 , wherein said disc springs make up a first spring assembly comprising a plurality of said disc springs and seated on a member, and a second spring assembly comprising a plurality of said disc springs and operatively coupled to said first spring assembly by said member, and wherein said piston is biased toward said fluid chamber at least by said first spring assembly and said second spring assembly. 
   
   
       5 . A cylinder mechanism according to  claim 4 , wherein said second spring assembly has a spring constant greater than said first spring assembly. 
   
   
       6 . A cylinder mechanism according to  claim 5 , wherein when said piston is moved under the fluid pressure of said working fluid to define said fluid chamber, said first spring assembly is compressed and thereafter said second spring assembly is compressed through said member. 
   
   
       7 . A pedal simulator comprising a cylinder mechanism for absorbing a fluid pressure generated in a pressurization chamber of a master cylinder by operating a brake pedal, wherein said cylinder mechanism comprises:
 a housing;   a piston slidably held in said housing and defining a fluid chamber for introducing a working fluid thereinto;   a plurality of disc springs for urging said piston toward said fluid chamber, at least two of said disc springs having respective bottom ends facing each other; and   a circular member having an arcuate surface held against respective inner surfaces of said at least two of said disc springs.   
   
   
       8 . A brake apparatus comprising:
 a pedal simulator according to  claim 7 ; and   a braking force generator for generating a braking force based on the fluid pressure generated by at least said master cylinder.