Wound core producing apparatus and wound core producing method

A wound core producing apparatus, the wound core being formed by bending and laminating a steel sheet, the wound core producing apparatus comprising:

• a bending device that bends the steel sheet;
• and
• a feed roll that feeds the steel sheet to the bending device,
• wherein
• the bending device includes a die and a punch for press working,
• the punch is shifted in a conveyance direction of the steel sheet with respect to the die,
• the die includes a curved portion disposed at an end portion on the punch side, and a flat portion continuously connected to the curved portion from a direction opposite to the punch side and in contact with the steel sheet, and
• when a distance from a center of the feed roll to an end surface on the die side of the punch along the conveyance direction of the steel sheet is denoted by L mm, a diameter of the feed roll is denoted by R mm, a pressure applied to the steel sheet by the feed roll is denoted by p MPa, and a temperature at a position 20 mm away from a boundary between the curved portion and the flat portion in a direction opposite to the conveyance direction is denoted by T° C., the following formulas (1) and (2) are satisfied,
• 0
• .
• 1
• ⁢
• 2
• ≤
• (
• L
• ×
• p
• )
• /
• (
• T
• ×
• R
• )
• ≤
• 0
• .40
• (
• 1
• )
• 0.4
• ≤
• p
• ≤
• 2
• ⁢
• .00
• .
• (
• 2
• )