Pipe fixing structure and pipe fixing method

Abstract

A pipe fixing structure and method are disclosed. In the pipe fixing structure, an ejector 1 on which a pipe 2 is to be fixed is subjected to a pressure which is exerted on the pipe 2 thereby to deform and fix the pipe 2 . An enlarged portion 1 a larger than the outer diameter of the pipe 2, through which the pipe 2 can be inserted in axial direction, is formed in the ejector 1 . A thin portion 2 a is formed on the inner peripheral portion of the pipe 2 , and a first projection 6 is formed by plastic deformation of the thin portion 2 a of pipe 2 under the pressure. The first projection 6 coincides with the enlarged diameter portion 1 a so that the pipe is fixed on the ejector 1.

1 . A pipe fixing structure for deforming and fixing a pipe by applying a force to press the pipe in axial direction against an object member to which the pipe is to be fixed, the pipe fixing structure comprising: 
 an enlarged diameter portion formed in the object member, which portion is larger than the outer diameter of the pipe and through which the pipe can be inserted in axial direction; and    a first projection into the shape of which a thin portion of the pipe is deformed under the pressure;    wherein the first projection coincides with the enlarged diameter portion.    
   
   
       2 . A pipe fixing structure according to  claim 1 , comprising a second projection projected radially outward from the pipe and integrated with the object member in the boundary between the fixed pipe and the outer surface of the object member.  
   
   
       3 . A pipe fixing structure according to  claim 2 , 
 wherein the second projection is formed in a substantially uniform thickness along the shape of the outer surface of the object member.    
   
   
       4 . A pipe fixing structure according to  claim 1 , 
 wherein the cross section of the enlarged diameter portion in axial direction of the pipe is progressively reduced outward.    
   
   
       5 . A pipe fixing structure according to  claim 1 , 
 wherein the object member is an ejector for the refrigeration cycle.    
   
   
       6 . A pipe fixing method comprising the steps of: 
 forming a thin portion on the inner periphery of the pipe;    forming an enlarged diameter portion, in the object member to which the pipe is fixed, which portion is located at a position corresponding to the thin portion and through which the pipe can be axially inserted; and    inserting the pipe into the object member, and pressing the pipe in axial direction so that the thin portion is deformed by being projected outward into coincidence with the enlarged diameter portion.    
   
   
       7 . A pipe fixing method according to  claim 6 , 
 wherein the pipe inserted into the object member is pressed in axial direction by gripping the outer peripheral portion of the pipe with a chuck and moving the chuck in axial direction.    
   
   
       8 . A pipe fixing method according to  claim 6 , 
 wherein the thin portion is deformed into coincidence with the enlarged diameter portion, after which pressure is applied to the pipe thereby to buckle the pipe in the boundary between the fixed pipe and the outer surface of the object member.    
   
   
       9 . A pipe fixing method according to  claim 8 , 
 wherein the chuck moved in axial direction while gripping the outer peripheral portion of the pipe has an end surface in opposed relation to the outer surface of the object member on the side thereof for gripping the pipe, which end surface is formed along the outer surface of the object member.    
   
   
       10 . A pipe fixing method according to  claim 9 , 
 wherein the outer surface of the object member is curved, and that end surface of the chuck which grips the pipe and which is nearer to the object member is curved or inclined along the shape of the curved outer surface of the object member.    
   
   
       11 . A pipe fixing method according to  claim 6 , comprising the step of inserting the pipe into the object member and pressing the object member in axial direction with a support member inserted in the pipe, thereby deforming the thin portion into an outward projection coincident with the enlarged diameter portion.  
   
   
       12 . A pipe fixing method comprising: 
 the step of forming an opening into which the pipe can be inserted, in the object member to which the pipe is to be fixed, and forming an enlarged diameter portion larger than the insertion opening and the outer size of the pipe in the object member; and    the step of inserting the pipe into the object member from the insertion opening and holding the outer surface of the pipe while deforming by projecting the outer peripheral portion of the pipe outward into coincidence with the enlarged diameter portion by applying the axial pressure to only the pipe.