A heat exchanger having a core. A header is on a side of the core, and a tank is brazed to the header. A connector is brazed to an outer surface of the tank. A welding aperture is defined by the tank beneath the connector. A weld at the welding aperture secures the connector to the tank prior to brazing of the connector and the tank together.

A header plate includes slots to receive heat exchange tubes of a heat exchanger. Each slot includes a lip extending in a direction of the tubes. Each slot has straight sides and corners. At least two tabs extend from each lip. One tab is on one side of each lip, and another tab is on an opposite side of each lip. Tabs are absent from the corners of the lip. Each tab is turned out from the lip so that the tabs on the lip act as a lead in for a tube entering the slot. Each slot has two long sides opposite one another. At least one tab is on each long side of the lip.

A heat exchanger includes a header part that is arranged on an outer surface side of a sidewall part of a case into which a combustion gas is supplied, and has hole parts through which end parts of heat transfer tubes are inserted and forms a chamber communicating between insides of the heat transfer tubes. The heat exchanger further includes a burring part in a tubular shape that protrudes from a circumferential edge part of each hole part of the header part toward the sidewall part side and is externally fitted to the end part of each heat transfer tube, and an extension part that partially extends from a part of a tip circumferential edge part of the burring part toward the sidewall part side and has a tip part abutting against the sidewall part.

The heat exchanger has tubes and a header tank that is located at an end of the tubes in a longitudinal direction and communicates with the tubes. The header tank has a core plate that connects to the tubes and a tank body that is fixed to the core plate. The core plate has a tube connection surface, a sealing surface, and an inclined surface that connects the tube connection surface and the sealing surface with each other. A distance between the tube connection surface and an end surface of the tubes in the longitudinal direction is different from a distance between the sealing surface and the end surface in the longitudinal direction by disposing the inclined surface to incline with respect to the longitudinal direction. The tubes connect to the tube connection surface and the inclined surface in a condition of being inserted to the tube connection surface and the inclined surface.

A tube header for a heat exchanger includes a header plate having two major dimensions defining a header plane. The header plate has a row of oblong passages extending through the header plate, and a plurality of tie bars. Each tie bar is arranged between a pair of adjacent oblong passages. At least one of the tie bars is a support tie bar with a generally W-shaped support tie bar profile in a cross-section across the row of oblong passages. The support tie bar has a center area forming a plateau surface parallel to the header plane and connecting two generally V-shaped portions of the support tie bar profile. The plateau surface supports an internal header baffle extending perpendicular to the header plane.

The heat exchanger has tubes and a header tank that is located at an end of the tubes in a longitudinal direction and communicates with the tubes. The header tank has a core plate that connects to the tubes and a tank body that is fixed to the core plate. The core plate has a tube connection surface, a sealing surface, and an inclined surface that connects the tube connection surface and the sealing surface with each other. A distance between the tube connection surface and an end surface of the tubes in the longitudinal direction is different from a distance between the sealing surface and the end surface in the longitudinal direction by disposing the inclined surface to incline with respect to the longitudinal direction. The tubes connect to the tube connection surface and the inclined surface in a condition of being inserted to the tube connection surface and the inclined surface.

A stacking-type header includes a first plate having a first through-hole; a second plate having a plurality of second through-holes; a third plate in which a flow path that communicates between the first through-hole and the second through-holes is formed, a first pipe including a first end portion that is inserted into the first through-hole; a plurality of second pipes each including a second end portion that is inserted into a corresponding one of the second through-holes; and brazing portions. The first pipe includes a first expanded portion in the first end portion, the first expanded portion having an outer peripheral surface that is pressed against an inner peripheral surface of the first through-hole. Each of the second pipes includes a second expanded portion having an outer peripheral surface that is pressed against an inner peripheral surface of a corresponding one of the second through-holes.

A heat exchanger may include a block for separately conducting first and second fluids, and a box. The block may have flat tubes through which the first fluid is flowable and each of which may have a narrow tube side and a wide tube side. The box may have a base, the flat tubes being guided into the base via corresponding through-openings in the base. Each through-opening may have at least one raised edge, with at least one narrow edge side and at least one wide edge side, surrounding the corresponding flat tube. The wide edge side may be higher than the narrow edge side. The two may transition into one another via an inclination with a recess that may have a height lower than that of the narrow edge side. A contact surface edge may have a height lower at the recess than at the narrow edge side.

A heat transfer tube as a first refrigerant pipe has a first portion, a first expansion portion, a second portion, a second expansion portion, and a third portion arranged in order. A connecting tube as a second refrigerant pipe has a fourth portion facing the second portion and a fifth portion facing the third portion. The connecting tube is inserted into the heat transfer tube. The inner diameter of the second portion is larger than the inner diameter of the first portion, and the inner diameter of the third portion is larger than the inner diameter of the second portion. The outer diameter of the fifth portion is larger than the outer diameter of the fourth portion. The fifth portion and the third portion are brazed.

A heat exchanger includes tubes and a header tank. The header tank includes a core plate and a tank body. The core plate includes a tube connection surface and a receiving portion that houses an end portion of the tank body. The receiving portion includes a bottom wall and an inner wall that connects the bottom wall to the tube connection surface. The tube connection surface and the inner wall are connected to a rib. The rib is located between adjacent two tubes and inclined with respect to a longitudinal direction of the tubes. The rib includes one end connected to the tube connection surface and an other end connected to the inner wall. The tubes includes lateral ends in the width direction, and a clearance, which has a specified dimension, is defined between the inner wall and the lateral ends in the width direction.