Fluid pressure cylinder and rolling mill

Abstract

Hydraulic cylinders are provided in a housing so as to be opposed to roll chocks. Each of the hydraulic cylinders is constituted by movably fitting a thin plunger via a liner into a cylinder fixed to the housing, movably fitting a concave portion of the thin plunger over a center guide on the cylinder to form guide means, and connecting a liner for thrusting each of the roll chocks to a front end portion of the thin plunger.

What is claimed is:  
     
         1 . A fluid pressure cylinder comprising: 
 a cylinder of a cylindrical shape;    a thin plunger fitted along an inner wall surface of the cylinder so as to be movable in an axial direction;    an output portion provided at one end portion of the thin plunger; and    guide means provided between the cylinder and other end portion of the thin plunger by having a concave portion and a convex portion fitted to each other, and adapted to guide movement of the thin plunger relative to the cylinder.    
     
     
         2 . A rolling mill comprising: 
 a housing;    upper and lower rolling rolls rotatably supported by the housing via roll chocks;    screw down means provided in an upper portion of the housing and adapted to apply a predetermined pressure to the rolling roll; and    hydraulic cylinders for thrusting the roll chocks along a transport direction of a rollable material to press the roll chocks against the housing, and further including    guide means each provided between a cylinder constituting each of the hydraulic cylinders and a shaft end portion of a thin plunger by having a concave portion and a convex portion fitted to each other, and adapted to guide movement of the thin plunger.    
     
     
         3 . The rolling mill of  claim 2 , wherein the thin plunger is movably supported in the housing, and a liner capable of contacting and thrusting the roll chock is connected to a front end portion of the thin plunger.  
     
     
         4 . The rolling mill of  claim 3 , further including greasing means for greasing a surface of the liner.  
     
     
         5 . The rolling mill of  claim 2 , wherein the thin plunger is provided in a liner portion contacting the roll chock, is movably supported by the liner, and has a front end portion capable of thrusting the roll chock.  
     
     
         6 . The rolling mill of  claim 5 , further including greasing means for greasing a front end surface of the thin plunger.  
     
     
         7 . The rolling mill of  claim 2 , wherein the guide means includes a center guide of a cylindrical shape provided at a center of the cylinder, and a concave portion provided in the thin plunger and fitted over the center guide.  
     
     
         8 . The rolling mill of  claim 2 , wherein the thin plunger is movably fitted on an inner peripheral surface of the cylinder via a liner, a ring-shaped cover is fixed to the cylinder in correspondence with an outer peripheral portion of the thin plunger, an oil pressure supply chamber is provided between the cylinder and the thin plunger, and a pullback mechanism is provided between the cover and the thin plunger.