A method of manufacturing a knife blade for a cutter knife of an agricultural harvesting machine, wherein a substantially disk-shaped blade blank is provided in a providing step, said blade blank having a bottom side extending in a first plane (YZ1) and a top side extending in a second plane (YZ2), wherein a hole connecting the first plane (YZ1) with the second plane (YZ2) is made in the blade blank, wherein in a reshaping step an area of the blade blank surrounding the hole is deformed in such a way that a top contact surface surrounding the hole is formed in a third plane (YZ3), wherein the third plane is more distant from the first plane than the second plane (YZ2) in a normal direction (X) perpendicular to the first plane (YZ1).

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.

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.

Disclosed are a support unit and a floor plate. The support unit includes a first plate and a second plate which are spaced apart from each other, one end of the first plate is provided with a plurality of first ring walls at intervals, one end of second plate facing the first plate is provided with a plurality of second ring walls at intervals, the plurality of second ring walls are arranged corresponding to the plurality of first ring walls, each of the second ring walls is sleeved outside and matched with a respective one of the first ring walls to form a support structure that supports the first plate and the second plate.

A processing method and a processing apparatus for a metal housing are provided. The method includes: sleeving a metal flat pipe having an end face provided with a curved surface portion on a lower mold; and pressing the curved surface portion by the cooperation between an upper mold and the lower mold, thereby forming a chamfered slanted surface on the curved surface portion. The processing processes and the apparatus involved are simple, the quality of the products is improved, and thus the method may be suitable for mass production.

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 method and device for producing a press-quenched part having a rim hole with a collar formed at the periphery of the rim hole includes inserting a temperature-controlled die into the rim hole of the part. The temperature of the temperature-controlled die is controlled such that the temperature of the part in a region of the collar is held above the martensite start temperature of the material from which the part is made. While the temperature of the collar is being held above the martensite start temperature, the remainder of the part is press quenched.

There is provided a hole widening method including a preparing process of preparing a forming tool which has a diameter-increasing portion increasing in diameter from a front end side toward a rear end side and a line-shaped projection formed to protrude outward from a surface of the diameter-increasing portion, and a workpiece in which a pilot hole is formed; and a hole widening process of successively widening the pilot hole by pushing the forming tool into the pilot hole such that the line-shaped projection of the forming tool comes into point contact with a part of a circumferential edge portion of the pilot hole in the workpiece two times or more, and forming a stretched flange.

A method for processing a steel plate capable of removing residual strain at a trim edge thereof without causing overheating in areas of the steel plate other than the trim edge. A method of processing a steel plate includes punching a steel plate and disposing heating electrodes in such a way that a trim edge punched in the punching is positioned between electrode surfaces facing each other and then heating a part of the steel plate including the trim edge.

A burring processing method including increasing a diameter of a prepared hole provided in a metal component and bending a part of the metal component to form a burring processed portion (110) including an upright portion (120) and a curved portion (130), wherein in a cross-section that passes through an axis (cb) of the burring processed portion (110) and is parallel to the axis (cb) of the buffing processed portion (110), a cross-sectional shape of the curved portion (130) on an inner surface of the curved portion consists of a curve, and a length of the curved portion (130) in a direction perpendicular to the axis (cb) of the burring processed portion (110) is at least 1.2 times a height of the curved portion in a direction parallel to the axis (cb) of the burring processed portion (110).