Pipe fitting mechanism and heat exchanger using same

A heat exchanger comprising:

• a panel material shaped into a box with one side open;
• a pipe fixed to said panel material, said pipe having a thin wall of uniform thickness;
• at least one section of a tank formed of said panel material and a seat panel joined to the open surface of said panel material;
• and
• a plurality of heat exchanging tubes with one end thereof being connected to said seat panel of said tank for communicating with said tank;
• wherein said panel material includes a cylindrical part projecting inward relative to a panel surface of said panel material at approximately a right angle to said panel surface, a ring-shaped part formed on an inner peripheral side of a tip end part of said cylindrical part and being approximately parallel to said panel surface, and pipe fitting hole formed at a central part of said ring-shaped part for fitting said pipe;
• wherein said pipe includes a flange part projecting generally radially outward thereof, said flange part being plastically formed by projecting and folding said thin wall, and a projecting portion comprising at least one projection defined adjacent a tip end of said pipe to be inserted into said pipe fitting hole;
• wherein said pipe and said panel material are locked to each other by contact at two interface positions between said projection portion and said ring-shaped part and between said flange part and said panel surface for preventing the displacement in an axial direction of said pipe;
• and
• wherein an annular sealing material is sandwiched between said outer peripheral surface of said pipe, said ring-shaped part, said cylindrical part, and flange part.

A heat exchanger comprising:

• a panel material shaped into a box with one side open;
• a pipe fixed to said panel material, said pipe having a thin wall of uniform thickness;
• at least one section of a tank formed of said panel material and a seat panel joined to the open surface of said panel material;
• and
• a plurality of heat exchanging tubes with one end thereof being connected to said seat panel of said tank for communicating with said tank;
• wherein said panel material includes a cylindrical part projecting inward relative to a panel surface of said panel material at approximately a right angle to said panel surface, a ring-shaped part formed on an inner peripheral side of a tip end part of said cylindrical part and being approximately parallel to said panel surface, and a pipe fitting hole formed at a central part of said ring-shaped part for fitting said pipe;
• wherein said pipe includes a flange part projecting generally radially outward thereof, said flange part being plastically formed by projecting and folding said thin wall, and a plurality of projections disposed adjacent a tip end of said outer peripheral surface for insertion into said pipe fitting hole;
• wherein said ring-shaped part includes a plurality of notched parts disposed on an inner peripheral side thereof for fitting with said plurality of projections, and a plurality of holding concave parts for holding said pipe while maintaining contact with said projections;
• wherein said pipe and said panel material are locked to each other with contact at two positions, one position being between said projections and said holding concave parts and the other position being between said flange part and said panel surface for preventing displacement in an axial direction of said pipe;
• and
• wherein an annular sealing material is sandwiched between said outer peripheral surface of said pipe, said ring-shaped part, said cylindrical part, and flange part.

A connection between a pipe and a separate element, said connection comprising:

• cylindrical part projecting inward from an outer surface of said separate element and a ring-shaped member formed at an inner end of said inward projecting cylindrical part;
• said pipe having a thin wall of uniform thickness;
• a flange projecting outward of said pipe, said flange being plastically formed by projecting and folding said thin wall;
• projections formed adjacent a tip end of said pipe;
• receiving elements formed in said separate element for receiving and interacting with said projections;
• wherein said separate element locks to said pipe by contact between an outer peripheral surface of said pipe and said ring-shaped member, and between said outer surface of said separate element and said flange;
• wherein a sealing member is disposed in an annular hole defined by said outer peripheral wall, said flange, said cylindrical part, and said ring-shaped member.