Method and apparatus for manufacturing aluminum alloy extruded part

1 . A method for manufacturing an aluminum alloy extruded part, the method comprising:

hot-extruding a 7000 series aluminum alloy by an extruder to form an extruded material;

cutting the extruded material as it moves forward from the extruder to a predetermined length;

applying plastic working to the cut extruded material in a state in which Vickers hardness of the cut extruded material is 50 Hv or higher and 70 Hv or lower; and

applying aging treatment to the extruded material after the plastic working,

wherein a time T minute(s) from the extrusion of the extruded material from the extruder to completion of the plastic working is set within a range of a following formula in relation to a yield strength σ MPa of the extruded material:

T≤− 0.59σ+322.

2 . The method for manufacturing an aluminum alloy extruded part according to claim 1 , wherein

the extruded material has a hollow shape,

the method further comprising:

inserting a nozzle from a front into an inside of the extruded material that is extruded from the extruder and that moves forward; and

injecting a refrigerant from the nozzle to cool the extruded material.

3 . The method for manufacturing an aluminum alloy extruded part according to claim 1 , further comprising:

clamping front and rear portions of a cutting place at a time of cutting the extruded material; and

cooling the cutting place of the extruded material and the clamped front and rear portions of the cutting place.

4 . The method for manufacturing an aluminum alloy extruded part according to claim 3 , further comprising tensile-straightening the extruded material in a cold state after cutting the extruded material to the predetermined length and before applying the plastic working.

5 . The method for manufacturing an aluminum alloy extruded part according to claim 1 , further comprising tensile-straightening the extruded material in a cold state after cutting the extruded material to the predetermined length and before applying the plastic working.

6 . The method for manufacturing an aluminum alloy extruded part according to claim 5 , further comprising stretching with a stretcher to provide the tensile-straighten of the cut extruded material.

7 . An apparatus for manufacturing an aluminum alloy extruded part, the apparatus comprising:

an extruder configured to form an extruded material by hot-extruding a 7000 series aluminum alloy;

a cutter configured to cut the extruded material to a predetermined length and separate the extruded material from the extruder;

a conveyer configured to convey the extruded material cut to the predetermined length;

a plastic working machine configured to apply plastic working to the extruded material conveyed by the conveyer; and

a controller configured to control the extruder, the cutter, the conveyer, and the plastic working machine so as to complete the plastic working on the extruded material within a predetermined time after the extrusion of the extruded material from the extruder,

wherein the predetermined time T minute(s) is set within a range of a following formula in relation to a yield strength σ MPa of the extruded material

T≤− 0.59σ+322.

8 . The apparatus for manufacturing an aluminum alloy extruded part according to claim 7 , further comprising a cooler configured to cool the extruded material extruded from the extruder.

9 . The apparatus for manufacturing an aluminum alloy extruded part according to claim 8 ,

wherein the cooler includes a nozzle configured to inject a refrigerant, and

wherein the nozzle is configured to advance and retreat along an extrusion direction of the extruded material.

10 . The apparatus for manufacturing an aluminum alloy extruded part according to claim 7 , wherein the cutter includes a cutoff tool and a pair of clamps configured to grip the extruded material and move forward in synchronization with the cutoff tool.

11 . The apparatus for manufacturing an aluminum alloy extruded part according to claim 10 , wherein at least one of the cutoff tool and the pair of clamps includes a cooler to cool the extruded material.

12 . The apparatus for manufacturing an aluminum alloy extruded part according to claim 11 , wherein the cutter has a function as a stretcher that grips front and rear ends of the extruded material with the pair of clamp members, widens a distance between the pair of clamp members, and tensile-straightens the extruded material.

13 . The apparatus for manufacturing an aluminum alloy extruded part according to claim 11 , further comprising a stretcher configured to tensile- straighten the cut extruded material.

14 . The apparatus for manufacturing an aluminum alloy extruded part according to claim 10 , wherein the cutter has a function as a stretcher that grips front and rear ends of the extruded material with the pair of clamps, widens a distance between the pair of clamps, and tensile-straightens the extruded material.

15 . The apparatus for manufacturing an aluminum alloy extruded part according to claim 10 , further comprising a stretcher configured to tensile- straighten the cut extruded material.

16 . The apparatus for manufacturing an aluminum alloy extruded part according to claim 7 , further comprising a stretcher configured to tensile- straighten the cut extruded material.