Abstract: An upper die holder apparatus having a holder body has an upper die clamp supported to the holder body with a supporting point supporting the upper die clamp in a vicinity of a center in a vertical direction of the holder body. A clamping force applier is provided to the holder body for pressing an upper portion of the upper die clamp so that the upper die clamp clamps the upper die. A pressure receiver is provided to an upper portion of the upper die clamp. The pressure receiver, having a pressure sensing surface, is provided so that its advancing and retreating are adjusted to a pressing direction by the clamping force applier and the pressure receiver is provided so that an opening amount of the upper die clamp at the time of unclamping is freely selected between a plurality of stages.

Abstract: An upper die supporting section for supporting an upper die is provided to a lower portion of a holder body 7, a pressing section for pressing the upper die against the upper die supporting section is provided to a lower portion of an upper die clamp 11 supported to the holder body 7 in a rocking manner with a vicinity of a center in a vertical direction being as a supporting point. A locking member which freely locks into a drop-proof groove provided to the upper die is provided to a lower portion of the upper die clamp 11, and it is biased towards the upper die supporting section. Clamping force applying means 13 for pressing an upper portion of the upper die clamp 11 so as to apply a clamping force for clamping the upper die using the upper die clamp 11 is provided.

Abstract: In an upper tool for a press brake formed with an inclined surface (9S) narrowed upwardly at an upper portion thereof and an engage groove (9G) formed under the inclined surface (9S). The inclined surface (9S) is brought into contact with an inclined surface of an upper tool clamp member (11), when the upper tool is clamped between an upper tool holder body (5) and an upper tool clamp member (11), in such a way that clamping force can be further increased when the upper tool is engaged with a die (63). Further, in an upper tool holder apparatus for a press brake, the pivotal upper tool clamp member (211) is formed with an engage projection (211P) for engaging a drop prevention groove (205G) formed in the upper tool (205).

Abstract: In an upper tool for a press brake clamped between a support plate (7) of an upper tool holder body (5) attached to a lower portion of an upper table (3) and an upper tool clamp member (11), the upper tool (9) is formed with an inclined surface (9S) narrowed upward at an upper portion thereof and with an engage groove (9G) engaged with an engage projection (11K) of the upper tool clamp member (11) and formed under the inclined surface (9S). Therefore, the inclined surface (9S) is brought into contact with an inclined surface of the upper tool clamp member (11), when the upper tool is clamped between the upper tool holder body (5) and the upper tool clamp member (11), in such a way that clamping force can be-further increased when the upper tool is engaged with a die (63).