Abstract: A tubular body having integral branch tubes for use in a distribution tank of a car air conditioner and a method for producing such tubular body. The tubular body is produced almost solely by a deformation process. The process for forming the tubular body includes a swelling step for swelling the sheet metal at predetermined positions to create cylindrically swelled portions by several stages, a boring step for boring the top end of the swelled portion to create branch tubes, a channel creating step for creating mating channel throughout the whole length of the sheet metal, a rounding step for rounding the sheet metal to form a tube having a desired sectional shape, and a mating step for mating the end of the rounded sheet metal with the mating channel. The production process further includes a divider creating step for dividing the space in the tubular body into a plurality of compartments by squeezing the tubular body.

Abstract: An exhaust manifold A that embodies the invention in one preferred form includes a double-wall structure 3 consisting of an inner shell IS and an outer shell OS. The double-wall structure has a substantially straight body portion 1, three branches 16 projecting downward from the body portion 1, and a curved tail portion 15. Each shell comprises half shells 1A and 1B that are mechanically interlocked at their edges 1c. Also the branches 16 are mechanically interlocked with a flange coupling 4. In addition, an outlet coupling 5 is mechanically interlocked with the tail portion 15.

Abstract: A tube flange assembly including attachment flanges associated by interlocking deformation with flared tubes. The flanges are placed with the attachment plates thereof arranged in juxtaposition with a tubular insert extending to within the tubes. A raised section on the tubular insert mates with the concavities formed in the annuluses of the flanges. The joint is drawn together by fasteners. Each attachment flange includes a fixing area for receiving the end of the tube. Outwardly of that fixing area, an annular channel forming a loop in cross section with the small circular gap provides tolerance to vibration.

Abstract: A muffler designed at least about the exterior surface by a barrel with end plates. An inlet tube and an exhaust pipe are associated with the end plates, respectively. The external joints are formed by locked seamed roll joints and S-shaped deformed joints to avoid welding at the exterior of the muffler. Tubes extending between baffle plates may also employ the S-shaped deformed joints. Joint tubes having some ability to telescope axially with the other internal components provide thermal stress relief.

Abstract: A flange joint assembly having first and second attachment flanges are associated with first and second tubes through an interengagement of the ends of the tubes between an inner annulus and an annular corrugation which are inwardly of an attachment plate. The annulus and corrugation with the interengaged tube end are flared outwardly to interlock the components. The tube also includes an outwardly tapered section adjacent to the end. A tubular insert having inwardly tapered outer surfaces extending to each end from a midsection is positioned within the tapered portions of two axially abutting tubes. Fasteners draw the attachment flanges together to complete the assembly.

Abstract: A pipe flange is formed with an opening into which is fitted a pipe, and an annular groove which is coaxial with the opening and surrounds the same. A cylindrical is defined between the opening and the annular groove coaxially. A folding-back portion is led to the cylindrical portion and is adapted to retain one leading end of the pipe fitted into the opening. A pipe retaining portion is led to the folding-back portion and is folded back radially inwardly over the cylindrical portion in parallel therewith and is spaced apart therefrom by a predetermined distance. Therefore, the joining process can be simplified, and the work environment will not be contaminated. In addition, the joint strength and the air tightness can be enhanced. The pipe integral with the flange for pipe fitting is light in weight. Furthermore, the present invention is adapted for the mass production by the simple joining method.

Abstract: A method of joining a pair of pipes involves inserting the ends of a pair of pipes into a fitting, and then axially compressing the fitting to produce readily outward bulging of the fitting at an intermediate portion thereof, the fitting being so configured as to cause outwards flaring of the pipe ends during axial compression of the fitting, the outwardly flared ends of the respective pipes then being entrapped within the fitting.

Abstract: A pair of pipes are joined airtightly and securely through a pipe joint including a cylindrical main body and a pair of contact portions integrally protruded apart from each other in the longitudinal direction of the main body on the central inner wall of the main body individually capable of contacting end surfaces of the pipes, and a pair of retaining portions integrally protruded from inside ends of the contact portions along the longitudinal direction of the main body for clamping joining ends of the pipes in conjunction with the main body, by inserting the pair of pipes between the main body of the pipe joint and the pair of retaining portions from both ends of the main body, and upsetting the pipe joint and the pair of pipes until the pair of retaining portions closely contact each other while projecting the central portion of the main body along with joining ends of the pair of pipes in the radial direction so that the joining ends of the pipes clamped between the projected central portion of the main