Diaphragm damper, and method and device for producing the same

Abstract

A method of producing a diaphragm damper 1 having a high pressure chamber 3 comprised of two diaphragms 2 with flanges 6 welded together and charged inside with a high pressure gas. The diaphragms 2 are made of magnetically attractable thin metal sheets. A pair of jigs 30, 40 provided to face each other inside the pressure vessel 20 hold the diaphragms 2 by magnetic force. The pressure vessel 20 is sealed and evacuated, then the pressure vessel 20 is charged and pressurized by a mixed gas including helium. After this, the pair of jigs 30, 40 are made to approach each other to make the flanges 6 of the pair of diaphragms 2 come into close contact. Inside the pressure vessel 20 , the jigs 30, 40 are simultaneously rotated to rotate the pair of diaphragms 2 and a laser beam is fired at the flanges 6 of the diaphragms 2 to weld the flanges 6 over their entire circumferences.

1 . A method of production of a diaphragm damper having a high pressure chamber comprised of two diaphragms welded together as their flanges and charged inside with a high pressure gas, comprising the steps of: 
 forming said diaphragms by magnetically attractable thin metal sheets and using a pair of jigs provided so as to face each other in a pressure vessel so as to hold the diaphragms by magnetic force,    sealing and evacuating said pressure vessel, then charging and pressurizing a mixed gas including helium in said pressure vessel, then bringing the pair of jigs close to each other to bring the flanges of the pair of diaphragms into close contact, and    simultaneously rotating said jigs in said pressure vessel to make the pair of diaphragms rotate and firing a laser beam at the outer peripheral edges of the flanges of said diaphragm from a direction substantially perpendicular to the shafts of said diaphragms so as to weld said flanges across their entire circumferences.    
   
   
       2 . The method of production of a diaphragm damper as set forth in  claim 1 , wherein each diaphragm has 
 a thin disk shaped flexible part formed with repeated patterns of coaxial concentric ring-shaped recesses and ring-shaped ridges,    a positioning part formed continuing from the outer periphery of this flexible part and bent to an arc-shaped cross-section so as to form a half space for a high pressure chamber in combination with said flexible part, and    the flange formed integral with the outer periphery of this positioning part to a flat ring shape, and    the diaphragms are formed to the same shapes as each other.    
   
   
       3 . The method of production of a diaphragm damper as set forth in  claim 2 , wherein each jig is formed with a positioning recess for holding the diaphragm so as to be positioned by said positioning part and, at the center of said positioning recess, a magnet for detachably holding the diaphragm by magnetic force is arranged.  
   
   
       4 . The method of production of a diaphragm damper as set forth in any one of  claims 1  to  3 , wherein said mixed gas including helium gas is mixed gas of 15 to 25 vol % of helium gas and 75 to 85 vol % of argon gas.  
   
   
       5 . The method of production of a diaphragm damper as set forth in any one of  claims 1  to  3 , wherein when welding said flanges over their entire circumference, inside said pressure vessel, the pressure of said mixed gas is, by gauge pressure, a pressure of 0.1 to 0.5 MPa.  
   
   
       6 . A diaphragm damper produced by the method as set forth in any of  claims 1  to  3 .  
   
   
       7 . A production apparatus of a diaphragm damper comprising: 
 a pressure vessel able to guide a laser beam inside it at least at part of it,    a pair of jigs provided to be able to rotate freely in said pressure vessel and to be able to move toward and away from each other along the direction of their shafts, and    a laser system disposed outside said pressure vessel and disposed to be able to fire a laser beam from a direction substantially perpendicular to the shafts of said jigs to the outer peripheral edges of flanges of diaphragms,    each jig provided with:    a recess against which a positioning part provided at an inside periphery of the flange of the diaphragm may abut for positioning and    a magnet for magnetically holding the diaphragm at said recess.