Abstract: Provided is a hole drilling machine and the method for drilling an oval hole and an inner-diameter-changing hole by means of the hole drilling machine, the machine and the method being configured so that the oval hole can be shaped with high accuracy and drilling of a complicated hole such as the inner-diameter-changing hole can be performed with high accuracy. A hole drilling machine 100 includes a spindle 101 and an auxiliary spindle 120 holding both end portions of a processing tool 102 having a cutting blade 103. The spindle 101 includes a spindle drive motor 106 configured to rotatably displace the processing tool 102 on a circular path, and a tool turnable-drive motor 105 configured to spin the processing tool 102. The auxiliary spindle 120 includes an auxiliary spindle drive motor 120b.

Abstract: An aluminum-alloy sheet has a chemical composition containing Si: 2.3-3.8 mass %, Mn: 0.35-1.05 mass %, Mg: 0.35-0.65 mass %, Fe: 0.01-0.45 mass %, and at least one element selected from the group consisting of Cu: 0.0010-1.0 mass %, Cr: 0.0010-0.10 mass %, Zn: 0.0010-0.50 mass %, and Ti: 0.0050-0.20 mass %. The ratio of the Si content to the Mn content is 2.5 or more and 9.0 or less. The aluminum-alloy sheet exhibits an elongation of 23% or more and a strain hardening exponent of 0.28 or more at a nominal strain of 3%. Such an aluminum-alloy sheet is well suited for press forming (stamping) applications, such as forming automobile body panels.

Abstract: Provided is a hole drilling machine and the method for drilling an oval hole and an inner-diameter-changing hole by means of the hole drilling machine, the machine and the method being configured so that the oval hole can be shaped with high accuracy and drilling of a complicated hole such as the inner-diameter-changing hole can be performed with high accuracy. A hole drilling machine 100 includes a spindle 101 and an auxiliary spindle 120 holding both end portions of a processing tool 102 having a cutting blade 103. The spindle 101 includes a spindle drive motor 106 configured to rotatably displace the processing tool 102 on a circular path, and a tool turnable-drive motor 105 configured to spin the processing tool 102. The auxiliary spindle 120 includes an auxiliary spindle drive motor 120b.

Abstract: Provided is a hole drilling machine and the method for drilling an oval hole and an inner-diameter-changing hole by means of the hole drilling machine, the machine and the method being configured so that the oval hole can be shaped with high accuracy and drilling of a complicated hole such as the inner-diameter-changing hole can be performed with high accuracy. A hole drilling machine 100 includes a spindle 101 and an auxiliary spindle 120 holding both end portions of a processing tool 102 having a cutting blade 103. The spindle 101 includes a spindle drive motor 106 configured to rotatably displace the processing tool 102 on a circular path, and a tool turnable-drive motor 105 configured to spin the processing tool 102. The auxiliary spindle 120 includes an auxiliary spindle drive motor 120b.

Abstract: Provided is a hole drilling machine and the method for drilling an oval hole and an inner-diameter-changing hole by means of the hole drilling machine, the machine and the method being configured so that the oval hole can be shaped with high accuracy and drilling of a complicated hole such as the inner-diameter-changing hole can be performed with high accuracy. A hole drilling machine 100 includes a spindle 101 and an auxiliary spindle 120 holding both end portions of a processing tool 102 having a cutting blade 103. The spindle 101 includes a spindle drive motor 106 configured to rotatably displace the processing tool 102 on a circular path, and a tool turnable-drive motor 105 configured to spin the processing tool 102. The auxiliary spindle 120 includes an auxiliary spindle drive motor 120b.

Abstract: An aluminum-alloy sheet has a chemical composition containing Si: 2.3-3.8 mass %, Mn: 0.35-1.05 mass %, Mg: 0.35-0.65 mass %, Fe: 0.01-0.45 mass %, and at least one element selected from the group consisting of Cu: 0.0010-1.0 mass %, Cr: 0.0010-0.10 mass %, Zn: 0.0010-0.50 mass %, and Ti: 0.0050-0.20 mass %. The ratio of the Si content to the Mn content is 2.5 or more and 9.0 or less. The aluminum-alloy sheet exhibits an elongation of 23% or more and a strain hardening exponent of 0.28 or more at a nominal strain of 3%. Such an aluminum-alloy sheet is well suited for press forming (stamping) applications, such as forming automobile body panels.