Hitachi, Ltd.

Masahiro Miyagi

Izumi Ochiai

Yoshio Nozawa

Yukio Kitayama

Katsuharu Uehara

Takahiko Deguchi

Masaaki Itoh

Katsuo Arai

Hiroshi Kogure

Yoichi Wakabayashi

Tadaaki Ayabe

Kenji Iino

Keikichi Morita

Yukio Kitayama, Deceased

Tamotsu Nakayama

A heat exchanger having different types of fins of different widths arranged such that different types of fins are arranged alternately can be efficiently produced by a process which has the steps of: forming a plurality of rows of refrigerant-tube holes in a hoop; forming lines of cutting which extend parallel to a direction of feed of the hoop at positions which are offset from the midpoint between adjacent rows of the holes, the lines of cutting having a length smaller than the longitudinal size of fins to be obtained; forming slits or elongated holes in positions of the hoop to which the ends of the lines of cutting is to be extended, the slits or elongated holes having longitudinal axes extending in the direction crossing the direction of feed of the hoop; cutting the hoop along a transverse line of cutting which extends in the direction crossing the direction of feed of the hoop past regions between adjacent slits or elongated holes which oppose to each other in the direction of feed of the hoop, thus severing a group of fins having a plurality of fins of different types connected integrally; stacking the succesively severed groups of fins; inserting refrigerant tubes into the holes in the fins and expanding the tubes so as to fix the tubes to the fins in the successive groups; and cutting the stacked successive groups of fins at positions between adjacent rows of the holes and within the regions of the slits or the elongated holes.

Heat exchanger and process for producing the same

An apparatus for producing various heat exchangers is disclosed in which a plurality of heat exchangers disposed side by side are formed at once. A series of manufacturing stations for working heat exchanger components such as fins and tubes and for opening the tubes are arranged in an endless manner to thereby automatically carry out the production steps with a high productivity while meeting various requirements of the specifications of the heat exchangers with a high flexibility.

Apparatus for assembling fins and tubes for heat exchangers

Disclosed is a tube-enlarging press in which clamping units are provided for preventing the fins and tubes used in a heat exchanger, from being buckled. The clamping units are provided with a through-hole for permitting the passage therethrough of mandrels falling outside of the area of the fin when the mandrels are lowered during the tube enlarging process. Therefore, the arrangements and preparations for replacement of the mandrels can be omitted.

Tube-enlarging press for use in heat exchanger fabrication

A fin-and-tube type heat exchanger is disclosed in which the height of each raised, slotted louver from a fin base portion continuously changes in a direction crossing at right angles both the direction of the air flow and the direction of lamination of fins, and two or three kinds of such louver pairs, each consisting of louvers symmetric with each other with respect to the fin base portion, are arranged regularly.

Fin-and-tube type heat exchanger

A method of stacking fins of heat exchangers suitable for use in producing fins of a plurality of heat exchangers arranged in a group widthwise thereof, characterized by causing one group of fins after another to adhere to a suction plate and forcedly inserting tube receiving apertures formed beforehand in the fins into stacking bars to thereby stack the groups of fins.

Method of stacking fins of heat exchangers

An internal groove forming apparatus for heat exchanging pipes, having a cylindrical holder adapted to be loosely fitted in a heat exchanging pipe in concentric relationship, and a plurality of groove forming rolling tools arranged on the holder in a plurality of axially spaced, circumferentially oriented rows and rotatably supported on the holder in such a manner that the rolling tools of one of the two adjacent rows are disposed in staggered relationship with respect to those of the other and an imaginary circle circumscribing the rolling tools is interposed between an outer peripheral surface and an inner peripheral surface of the heat exchanging pipe. Axial relative movements of the heat exchanging pipe and the holder enable the rolling tools to form a number of substantially axially oriented grooves on the inner peripheral surface of the heat exchanging pipe.

Growing community of inventors

Tochigi, Japan

Masahiro Miyagi