A heat exchanger and a fin are provided. The heat exchanger includes: a fin. The fin includes a fin body and a flange, the fin body being provided with a heat exchange tube hole, the flange being provided on the fin body and surrounding the heat exchange tube hole; and a heat exchange tube passing through the heat exchange tube hole and connected to the flange. The flange includes a first sub-flange and a plurality of second sub-flanges, the first sub-flange is connected to the fin body, the plurality of second sub-flanges are connected to the first sub-flange and spaced apart from one another, and a height of the first sub-flange is less than a height of the second sub-flange.

Provided are a forming method and a forming apparatus which can secure strength after forming while suppressing deformation.

The forming method of the present invention includes a burring step and a pressing step. In the burring step, a branch pipe is formed by causing a cylindrical peripheral wall of a cylindrical member (workpiece) having the peripheral wall to project in an outside direction in a tubular shape. In the pressing step, a distal end surface of the branch pipe is pressed toward a proximal end portion of the branch pipe. In the pressing step, the distal end surface of the branch pipe can be pressed by an end surface pressing punch in a state where a burring punch is inserted in the branch pipe.

In a method for producing a component by further forming of a preformed contour of a blank, the blank which has previously been cut to size at ambient temperature from a strip or a metal sheet undergoes after optional further manufacturing steps carried out at ambient temperature, e.g. punching or cutting operations to realize recesses or openings, in selected edge regions that have been strain hardened by the punching or cutting operations to obtain a preformed contour a first forming operation at ambient temperature. The edge regions intended to undergo the forming operation or at least the edge regions that have undergone the first forming operation are heated to a temperature of at least 600 C. for maximal 10 seconds. After the heat treatment, the edge regions undergo at any time a second forming operation or further forming operations at ambient temperature with respectively preceding heat treatments.

A convex portion projecting from a plate member includes a base, a convex body, and a guide. The base is part of the plate member. The convex body erects in a cylindrical shape from the base. The guide is at a top end of the convex body. The base includes a first inner circumferential surface, a second inner circumferential surface, and a third inner circumferential surface. The first inner circumferential surface is continuous with an inner circumferential surface of the convex body and extends in a direction opposite to an erecting direction of the convex body. The second inner circumferential surface is continuous with the first inner circumferential surface and intersects the erecting direction of the convex body. The third inner circumferential surface is continuous with the second inner circumferential surface and is larger in diameter than the first inner circumferential surface.

The invention relates to a method for the optimized production of a component, in particular from steel, with at least one secondary formed element, comprising the steps of a) providing a blank which has been cut to size at room temperature from a strip or a sheet and in which cut-outs and/or holes have optionally been created by stamping or cutting operations; b) thermal treatment of selected edge regions of the blank that have been cold-hardened by the stamping or cutting operations, in which the edge regions are heated to a temperature of at least 600 C. for a maximum 10 seconds; c) forming the thermally treated edge regions of the blank at ambient temperature to obtain a component with an unfinished secondary formed element; characterized by an additional step d), a calibrating step for obtaining the component with the secondary formed element, wherein the unfinished secondary formed element is formed at ambient temperature into a secondary formed element that has an increased and/or more uniform wall thickness in comparison with the unfinished secondary formed element.

Provided is a burring processing method, which is a method for forming a buffing processed portion including a raised portion and a curved portion in a metal component having a pilot hole formed therein, the method being characterized by including: a preforming step of enlarging a diameter of the pilot hole, moving an edge portion of the pilot hole relative to the metal component in a first direction of a thickness direction of the metal component in a first range around the pilot hole of the metal component, and forming the whole first range into a preformed portion raised from the metal component in the first direction; and a main forming step of deforming the preformed portion in a second direction opposite to the first direction, forming a second range on an outer diameter side of the preformed portion to have the same height as the first range in the first direction, and forming part of a third range on an inner diameter side of the preformed portion from the second range to be part of the curved portion and the raised portion.

A machining method for a burred flat hole includes first an overhang portion is formed in a flat hole-forming region in a metal plate in a first step, subsequently a fiat hole portion is formed in the overhang portion in a second step, and finally burring is formed on the peripheral edge portion of the hole portion in a third step. Accordingly, when burring is to be formed, overhanging machining and perforating machining have been substantially completed, and therefore pressing force of a punch for burring machining can be set to the minimum value necessary for burring formation.

After an annular plate is blanked from a metal flat plate in a blanking step, an inner peripheral portion of the annular plate is deformed upward in a burring step. As a result, a hat-shaped intermediate product having an upstanding tubular portion and an annular plate portion is formed. After that, an outer peripheral portion of the annular plate portion is folded step by step toward an inner peripheral side of the annular plate portion. As a result, a folded portion composed of a first folded portion and a second folded portion is formed, whereby a connection portion having a second flange portion is formed.

To reliably form an effectively functioning burring hole in a steering member. The steering member includes a metal tubular main body extending in a vehicle width direction, wherein a burring hole is formed in a circumference surface of the main body, an edge of the burring hole extrudes inward the main body, and the edge of the burring hole has a droop amount in a circumference direction of the main body and a droop amount in an axis direction of the main body.

In performing burring processing on a sheet-like member, the following processes are performed: a punching process of performing punching processing of the sheet-like member; a hole expansion process of performing hole expansion processing of a punched hole formed by the punching process; a re-punching process of performing punching processing again on a portion surrounding the punched hole expanded by force in the hole expansion process; and a burring process of pushing a portion surrounding a re-punched hole that is a punched hole formed by the re-punching process and forming a vertical wall.