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AssigneeShowa Aluminum Corporation
InventorsHideyuki Kobayashi, Mitsuru Nobusue, Noboru Kodachi, Tustomu Motohashi, Hironaka Sasaki, Ryoichi Hoshino, Koji Tomita, Haruo Fujinuma
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A method of making a brazeable metal pipe which has elliptical tube-insertion apertures and guide lugs extending from at least one of the opposite edges defining the minor axis of each aperture, with the guide lugs extending in the direction of insertion of flat tubes. The method in an embodiment comprises the steps of: bending a part of a raw strip, which may be previously embossed to form recesses, so as to provide a bulged portion arc-shaped in cross section and connected to at least one unbulged flat portions; pressing inwardly to form inward swells; subsequently punching each inward swell to provide the tube-insertion aperture so that at least one of the opposite edges located at ends of the minor axis of said aperture remains unpunched; and finally bending the at least one unbulged portions to produce the finished pipe. Alternatively, the method may comprise the step of: punching raw apertures through the raw strip so that each aperture has protrusions; bending it to form the bulged portion; bending the protrusions to give the guide lugs; and finally bending the unbulged portions, thus any complicated die is not needed and the pipe wall is protected well from being collapsed or deformed.
A method of making a brazeable metal pipe having a plurality of tube-insertion apertures of an elliptical shape and also having guide lugs formed integral with and extending from at least one of the opposite peripheral edges defining therebetween the minor axis of the elliptical aperture, with the guide lugs extending in parallel with the direction of insertion of flat tubes into the aperture, comprises the steps of:
A method of making a brazeable metal pipe having a plurality of tube-insertion apertures of an elliptical shape and also having guide lugs formed integral with and extending from at least one of the opposite peripheral edges defining therebetween the minor axis of the elliptical aperture, with the guide lugs extending in parallel with the direction of insertion of flat tubes into the aperture, the method comprising the steps of:
A method of making a brazeable metal pipe having a plurality of tube insertion apertures of an elliptical shape and also having guide lugs formed integral with and extending from at least one of the opposite peripheral edges defining therebetween the minor axis of the elliptical aperture, with the guide lugs extending in parallel with the direction of insertion of flat tubes into the aperture, the method comprising the steps of:
A method of making a brazeable metal pipe having a plurality of tube-insertion apertures of an elliptical shape and also having guide lugs formed integral with and extending from at least one of the opposite peripheral edges defining therebetween the minor axis of the elliptical aperture, with the guide lugs extending in parallel with the direction of insertion of flat tubes into the aperture, the method comprising the steps of:
The method as defined in 2 or 4, wherein the outer edge of each recess is formed upright in the direction of, or slightly slanted outwardly with respect to the direction cf, the thickness of the raw strip, before the raw strip is bent to provide the bulged portion.
The method as defined in 1, 2, 3 or 4, wherein the lateral ends of the raw strip are pressed in the direction of its thickness, but in opposite directions, i.e., upwardly for one of the lateral ends and downwardly for the other lateral end, before the raw strip is bent to provide the bulged portion, whereby one of the thus chamfered or slanted ends becomes thinner from its lower edge towards its upper edge, while the other slanted end contrarily becomes thinner from its upper edge towards its lower edge, and both the slanted ends are covered with the brazing substance layer.
The method as defined in 1, 2, 3 or 4, wherein slits are punched at opposite side zones of the raw strip, before the raw strip is bent to provide the bulged portion, so that the slits can be coupled with one another to provide an integral opening in which a partition of the heat exchanger is inserted and secured later, whereby the coolant is caused to flow in a meandering manner within the heat exchanger.
The method as defined in 1, 2, 3 or 4, wherein cutouts are formed at opposite side zones of the raw strip, before the raw strip is bent to provide the bulged portion, so that the cutouts can be coupled with one another to provide a bore in which a coolant inlet or outlet pipe of the heat exchanger is inserted and secured later.
A method of making a brazeable metal pipe having a plurality of tube insertion apertures of an elliptical shape and also having guide lugs formed integral with and extending from at least one of the opposite peripheral edges defining therebetween the minor axis of the elliptical aperture, with the guide lugs extending in parallel with the direction of insertion of flat tubes into the aperture, the method comprising the steps of:
A method of making a brazeable metal pipe having a plurality of tube insertion apertures of an elliptical shape and also having guide lugs formed integral with and extending from at least one of the opposite peripheral edges defining therebetween the minor axis of the elliptical aperture, with the guide lugs extending in parallel with the direction of insertion of flat tubes into the aperture, the method comprising the steps of:
Dependencies are inferred from the claim text.