曲げR、曲率半径：そうか単位は度じゃなかった

曲率半径 〜曲線の曲がり具合を計算する〜

「曲線を、ある一点で円で近似した時の、その円の半径」

曲率半径が小さい＝円が小さい＝曲がりの角度（曲げ角）が大きい

 

曲げRの計算方法【基礎知識】図面指示と板厚・強度、Mitsuri Media

「曲げRは曲げ角と混同されがちです。曲げRは曲げ半径を指します。」

 

What does 内側曲げ半径を２ｔとする mean?

ChatGPT:

内側曲げ半径を２tとする means "setting the inner bending radius to 2t" or "with an inner bending radius of 2t."

Here:

• 内側曲げ半径 (inner bending radius) refers to the radius on the inner side of the bend.
• ２t means the radius is twice the material thickness (t).

So, the phrase indicates that the bending process was performed with an inner radius equal to twice the thickness of the decorative metal plate.

あなた:

What is "radius"?

ChatGPT:

A radius is the distance from the center of a circle to its edge. In the context of bending, the bending radius refers to the curvature of the bend, specifically the distance from the center of the bend to the inner surface of the material.

In 内側曲げ半径 (inner bending radius):

• "Inner" means the radius is measured on the inside of the bend.
• "Bending radius" refers to the curve created when a material is bent.
• "2t" means this radius is twice the material thickness.

For example, if the metal plate is 1 mm thick, an inner bending radius of 2t would be 2 mm.

あなた:

What do you mean by "the radius would be 2 mm"? Isn't "radius" expressed in degrees?

ChatGPT:

No, radius is not expressed in degrees. Radius is a length measurement, typically in millimeters (mm) or other units of distance.

Clarification: Radius vs. Angle

• Radius (mm, cm, inches, etc.) → The distance from the center of a curve to its inner or outer edge.
• Angle (degrees, °) → The measure of how much something is bent or rotated.

In bending, we typically talk about:

1. Bending angle (°) – How far the material is bent (e.g., 180° bend).
2. Bending radius (mm or "t") – The curvature of the bend, defined as the distance from the bend's center to the inner surface.

Example

If you have a metal plate with a thickness of 1 mm, and the inner bending radius is 2t, then:

• t = 1 mm
• 2t = 2 mm
• So the inner bending radius is 2 mm, meaning the curve has a 2 mm distance from its center to the inner surface.

Would you like a diagram to help visualize this?

あなた:

Yes.

ChatGPT:

Inner Bending Radius (2t) in a 180° Bend

Here’s a diagram illustrating the inner bending radius (2t) in a 180° bend:

• The blue curve represents the centerline of the bend, with a radius of 2t.
• The red dashed curve is the inner surface, which has a radius of (2t - t) = t.
• The green dashed curve is the outer surface, which has a radius of (2t + t) = 3t.
• The black double arrow indicates the inner bending radius (2t), which is measured from the bend center to the inner surface of the metal plate.

Let me know if you need further clarification! ​