Hose with sealing layer, direct-connect assembly including the same, and method of manufacturing the same

Abstract

In a hose having a resin layer as an inner layer, a plasma treatment is performed on the inner surface of the inner layer and a connecting portion of an end part of the hose to thereby perform surface modification. Then, a sealing layer made of an elastic material is coated on and bonded to the inner surface of the connecting portion.

1 . A hose with a sealing layer, comprising: 
 a connecting portion on one end part of the hose;    a resin layer as an inner layer of the hose; and    a sealing layer made of an elastic material;    wherein a functional group including oxygen is formed in the resin layer of the connecting portion, and the sealing layer is coated on and bonded to an inner surface of the resin layer.    
   
   
       2 . The hose with a sealing layer according to  claim 1 , wherein the resin layer is made of a melt formable resin.  
   
   
       3 . The hose with a sealing layer according to  claim 1 , wherein the resin layer is made of a fluororesin.  
   
   
       4 . The hose with a sealing layer according to  claim 1 , wherein the resin layer comprises one selected from the group consisting of ethylene-tetrafluoroethylene copolymer, thermoplastic polyester elastomer, polybutylene terephthalate, polyphenylenesulfide, polyethylene, and polypropylene.  
   
   
       5 . The hose with a sealing layer according to  claim 4 , wherein the resin layer is made of alloy material including one selected from the group consisting of ethylene-tetrafluoroethylene copolymer, thermoplastic polyester elastomer, polybutylene terephthalate, polyphenylenesulfide, polyethylene, and polypropylene.  
   
   
       6 . The hose with a sealing layer according to  claim 1 , wherein the hose is used in a vehicle.  
   
   
       7 . The hose with a sealing layer according to  claim 1 , wherein an atmospheric plasma treatment is performed on the resin layer to form the functional group including oxygen therein.  
   
   
       8 . The hose with a sealing layer according to  claim 1 , further comprising: 
 a flare part expanded like a horn and provided at an end of the connecting portion;    wherein the flare part and straight-shaped other portions of the connecting portion are substantially uniformly modified; and    adhesive strength between the sealing layer and each of the flare part and the straight-shaped other portions is set at substantially equal strength.    
   
   
       9 . The hose with a sealing layer according to  claim 1 , wherein the functional group is a carbonyl group or a hydroxyl group.  
   
   
       10 . A direct-connect assembly comprising: 
 a metal pipe; and    a hose with a sealing layer, comprising: 
 a connecting portion on one end part of the hose;  
 a resin layer as an inner layer of the hose; and  
 a sealing layer made of an elastic material;  
 wherein a functional group including oxygen is formed in the resin layer of the connecting portion, and the sealing layer is coated on and bonded to an inner surface of the resin layer;  
   wherein an end part of the metal pipe is press-fitted into the connecting portion and the metal pipe is directly connected to the hose.    
   
   
       11 . A method of manufacturing a hose with a sealing layer, the hose including a connecting portion on one end part thereof, a resin layer as an inner layer of the hose and a sealing layer made of an elastic material, the method comprising: 
 sending a plasma gas generated by glow discharge between a pair of electrodes to an inner surface of the inner layer of the connecting portion to thereby modify the inner surface by action of the plasma gas; and    coating the sealing layer on the inner surface to bond the sealing layer to the inner surface.    
   
   
       12 . The method according to  claim 11 , wherein in sending the plasma gas, an abutting die is used, against which an end part of the hose abuts, the abutting die having an insertion space into which the end part of the hose is inserted, a gas introducing space extending from the insertion space and penetrating through the abutting die in a direction opposite to the insertion space, and a blocking portion operative to block the plasma gas introduced through the gas introducing space from going around to an outer surface of the hose; and 
 the plasma gas is introduced to the inner surface of the inner layer of the connecting portion through the gas introducing space to thereby modify the inner surface by action of the plasma gas.    
   
   
       13 . The method according to  claim 11 , wherein in sending the plasma gas, an abutting die is used, against which an end part of the hose having a flare part abuts, the abutting die having an insertion space into which the end part of the hose is inserted, a gas introducing space extending from the insertion space and penetrating through the abutting die in a direction opposite to the insertion space, a blocking portion operative to block the plasma gas introduced through the gas introducing space from going around to an outer surface of the hose, and a guide portion operative to lead the plasma gas to an end of the flare part; 
 the plasma gas is introduced to the inner surface of the inner layer of the hose through the gas introducing space to thereby modify the inner surface by action of the plasma gas; and    the guide portion causes the plasma gas to flow from the end of the flare part to an inside of the inner layer.