Abstract: A heat exchanger manufacturing method comprising: a welding step of disposing a first weld bead through a thickness of one of the inner and outer plate portions and fusing the first weld bead to other of the inner and outer plate portions for joining together the first and second case halves, to thereby provide the heat exchange tube; and a temporary tacking step of providing a temporarily-assembled end plate/tube unit by temporarily tacking the heat exchange tube to each of the end plates by means of a second weld bead and filling, with the second weld bead, a gap of a generally triangular shape defined, at each of the opposite end portions of the heat exchange tube, by an outer surface of the inner plate portion, an end surface of the outer plate portion and a corresponding one of the end plates.

Abstract: A heat exchanger includes a pair of end plates closing opposite ends of a cylindrical core case, and a plurality of heat exchange tubes each supported at opposite end portions by the end plates. The end plates have support holes, and opposite ends of the tubes are inserted into corresponding support holes in the end plates. Each of the tubes is formed by bending a plate material so that opposite side edge portions of the bent plate material are superimposed on each other, one of the superimposed side edge portions, located inward of the other of the superimposed side edge portions, forming an inner plate portion, the other of the superimposed side edge portions forming an outer plate portion, and then welding a weld bead through the thickness of one of the inner and outer plate portions to fuse to the other plate portion.

Abstract: A heat exchanger manufacturing method comprising: a welding step of disposing a first weld bead through a thickness of one of the inner and outer plate portions and fusing the first weld bead to other of the inner and outer plate portions for joining together the first and second case halves, to thereby provide the heat exchange tube; and a temporary tacking step of providing a temporarily-assembled end plate/tube unit by temporarily tacking the heat exchange tube to each of the end plates by means of a second weld bead and filling, with the second weld bead, a gap of a generally triangular shape defined, at each of the opposite end portions of the heat exchange tube, by an outer surface of the inner plate portion, an end surface of the outer plate portion and a corresponding one of the end plates.

Abstract: A heat exchanger includes: a pair of end plates closing opposite ends of a cylindrical core case; and a plurality of heat exchange tubes each supported at opposite end portions by the end plates, a first heat medium being caused to flow through the interior of the tubes, each of the tubes being formed by: bending a plate material so that opposite side edge portions of the bent plate material are superimposed on each other, one of the superimposed side edge portions, located inward of the other of the superimposed side edge portions, forming an inner plate portion, the other of the superimposed side edge portions forming an outer plate portion; and then causing a first weld bead, disposed through the thickness of one of the inner and outer plate portions, to be fused to the other plate portion.

Abstract: A heat exchanger including a tubular core case, a pair of end plates for closing opposite ends of the core case, and a plurality of heat exchange tubes supported at opposite ends thereof by the end plates and allowing flow of a first heating medium inside thereof. One end plate is disposed on an upstream side of the first heating medium as an upstream end plate while the other end plates is disposed on a downstream side of the first heating medium as a downstream end plate. The downstream end plate comprises a downstream bottom surface part for supporting downstream end parts of the heat exchange tubes, and a downstream wall part formed integrally with and rising from a peripheral edge of the downstream bottom surface part, and a top end part of the downstream wall part is oriented toward upstream of the flow of the first heating medium.