Abstract: In an inner fin, a plate is made up of a top part, a bottom part, and a wall plate part, and a channel having a concave-shaped cross section and a channel having an inverted concave-shaped cross section are alternately repeated as channels of the gas by a pair of the wall plate parts facing each other. The wall plate part for each of the channels has a shape in which the wall plate part is bent left and right in a serpentine shape and projected and recessed parts thereof are alternately repeated and formed, and the recessed part of the wall plate part is formed with a chevron-shaped part made up of an upward slope part that ranges from a base part to the top part and a downward slope part that passes downward from the top part to a neighboring base part.

Abstract: In an inner fin, a plate is made up of a top part, a bottom part, and a wall plate part, and a channel having a concave-shaped cross section and a channel having an inverted concave-shaped cross section are alternately repeated as channels of the gas by a pair of the wall plate parts facing each other. The wall plate part for each of the channels has a shape in which the wall plate part is bent left and right in a serpentine shape and projected and recessed parts thereof are alternately repeated and formed, and the recessed part of the wall plate part is formed with a chevron-shaped part made up of an upward slope part that ranges from a base part to the top part and a downward slope part that passes downward from the top part to a neighboring base part.

Abstract: There is provided an EGR cooler having a core portion in which a large number of flat tubes through which exhaust gases pass are stacked one on another in an interior of a hollow cylindrical shell to be joined to the shell for heat exchange between the exhaust gases and a cooling fluid which flows around the tubes, a cylindrical inlet header which is joined to an upstream side of the shell in relation to a gas flow at one end thereof, and a cylindrical outlet header which is joined to a downstream side of the core portion in relation to the gas flow at one end thereof, characterized in that the inlet header and the outlet header are joined to an outer surface of the shell, and the tubes are joined to an inner surface of the shell at those joint portions.

Abstract: There is provided an inner fin wherein: a sheet material is formed into an offset configuration in which grooves and ridges are formed alternately in a widthwise direction, and the grooves and the ridges are offset laterally at right angles to a gas flowing direction at predetermined length intervals in an alternate fashion; and a first projection and a second projection are formed for each segment surrounded by a pair of left and right side walls, by cutting either an upper surface portion or a lower surface portion and causing the cut surface portion to stand, the first projection being inclined towards an upstream side of the gas flowing direction, the second projection being disposed downstream of the first projection and being inclined towards a downstream side of the gas flowing direction at an angle equal to an angle at which the first projection is inclined.

Abstract: A sub-control valve is provided which detects a temperature of a liquid coolant in a main circulation path and separates part of the liquid coolant which is to be sent to a main radiator to send it into a sub-circulation path in case the detected temperature of the liquid coolant exceeds an upper limit value of the temperature of the liquid coolant when an engine runs in a steady state, and the liquid coolant which is sent into the sub-circulation path by the sub-control valve is cooled in a sub-radiator and is then caused to flow into a cooler device, while the liquid coolant in the sub-circulation path is separated to be returned to an upstream side of a first pump in the main circulation path.

Abstract: There is provided an EGR cooler having a core portion in which a large number of flat tubes through which exhaust gases pass are stacked one on another in an interior of a hollow cylindrical shell to be joined to the shell for heat exchange between the exhaust gases and a cooling fluid which flows around the tubes, a cylindrical inlet header which is joined to an upstream side of the shell in relation to a gas flow at one end thereof, and a cylindrical outlet header which is joined to a downstream side of the core portion in relation to the gas flow at one end thereof, characterized in that the inlet header and the outlet header are joined to an outer surface of the shell, and the tubes are joined to an inner surface of the shell at those joint portions.

Abstract: A plurality of beads protruding from an inner face of the tube are provided in such a manner that the beads are arranged at a predetermined pitch in an axial direction of the tube; and a circumference of the tube is divided at least into thirds, and the beads are aligned in a circumferential direction of the tube; and the beads aligned in the circumferential direction of the tube are provided at plural rows at the predetermined pitch in the axial direction of the tube, and the beads adjoining in the axial direction are shifted by substantially a half of a circumferential length of the bead to one another. Alternatively, the circumference of the tube is divided into parts of an even number of four or more, and the beads are aligned in the circumferential direction so as to be alternately formed in the parts of the circumference.

Abstract: Disclosed is a nickel-based brazing material obtained by adding to powdery brazing nickel a powder of at least one metal selected from the group consisting of nickel, chromium, nickel-chromium alloys, and SUS (stainless steel) in an amount of from 2 to 10% by weight, excluding 10% by weight, based on the nickel-based brazing material, followed by mixing.

Abstract: A ferritic stainless steel comprises C: not more than 0.025 wt %, Si: not more than 0.10 wt %, Mn: not more than 1.0 wt %, Cr: 17.0-25.0 wt %, Ni: not more than 0.50 wt %, Mo: 0.50-2.00 wt %, Al: not more than 0.025 wt %, N: not more than 0.025 wt %, at least one of Nb: 10(C wt %+N wt %)-1.0 wt % and Ti: 10(C wt %+N wt %)-1.0 wt %, and the balance being substantially Fe and inevitable impurities and is effectively used in various heat exchangers.

Abstract: A heat exchanger of a brazed-plate-fine type and a counter-flow type consists of a plurality of tube elements which define first-fluid flowing spaces while inner fins are disposed in the spaces, respectively. The tube elements are alternately laminated with a plurality of outer fins, and the laminated elements and fins are surrounded by a housing for constituting a second-fluid flowing space. A first-fluid inlet port and a first-fluid outlet ports are formed so as to outwardly project from a lateral side of the outer fin. The housing is formed to have curved portions conforming with projecting outer peripheries of the inlet and outlet ports. Accordingly, the heat transmission efficiency of the heat exchanger is improved.