Casting product reduction apparatus
The present invention is a casting product reduction apparatus that applies reduction to a casting product drawn from a mold with a sufficient reduction force and thereby can surely decrease center segregation and porosity and suppress occurrence of internal cracks so as to manufacture a high-quality casting product and includes: a pair of casting product press rolls that hold and press the casting product therebetween; backup rolls that support the casting product press rolls; and a pair of frames arranged to face each other, wherein three or more sets of the casting product press roll and the backup roll are arranged in a casting product drawing direction on each of the frames, and wherein a reduction means that decreases and increases a distance between the frames is provided at two or more places on the pair of frames.
1. A casting product reduction apparatus for applying reduction to a casting product drawn from a mold, comprising:
a pair of casting product press rolls that hold and press the casting product therebetween;
backup rolls that support the casting product press rolls; and a pair of frames arranged to face each other, each of the backup rolls supporting only a respective one of the pair of casting product press rolls and forming a set including the backup roll and the respective one of the pair of casting product press rolls,
wherein three or more sets of the casting product press roll and the backup roll are arranged in a casting product drawing direction on each of the frames,
wherein a reduction means that decreases and increases a distance between the pair of frames is provided at two or more places on the pair of frames, and
wherein at least one of the casting product press rolls forming a pair across the casting product has a large-diameter portion having a diameter that is larger than a diameter portion of a small diameter portion of the at least one of the casting product press rolls, the larger-diameter portion projecting outward in a diameter direction at a middle portion in an axial direction, and
wherein where a thickness of the casting product is t, an end region in a width direction of the casting product which is not subjected to reduction by the large-diameter portion of the casting product press roll is a region of 60 mm or more from an end in the width direction of the casting product and 1.5×t or less from the end in the width direction of the casting product.
2. The casting product reduction apparatus according to claim 1 ,
wherein the backup roll is divided into a plurality of parts in an axial direction of the casting product press roll.
3. The casting product reduction apparatus according to claim 1 ,
wherein the backup roll is arranged on a downstream side in a drawing direction of the casting product with respect to the casting product press roll.
4. The casting product reduction apparatus according to claim 1 ,
wherein the backup roll is divided in an axial direction of the casting product press roll, and at least one backup roll is arranged on a downstream side in a drawing direction of the casting product and at least one backup roll is arranged on an upstream side in the drawing direction of the casting product.
5. The casting product reduction apparatus according to claim 4 ,
wherein difference amount X in the drawing direction between a center axis of the casting product press roll and a center axis of the backup roll arranged on the downstream side is set to sin 0.23°×(Rw+Rb)≤X≤sin 5°×(Rw+Rb) in which Rw is a radius of the large-diameter portion and Rb is a radius of the backup roll.
6. The casting product reduction apparatus according to claim 1 ,
wherein each backup roll is divided into a plurality of parts in an axial direction of the casting product press rolls, each of said parts having a respective individual rotation axis, wherein bearings of the divided backup rolls have no interval therebetween in an axial direction.
7. The casting product reduction apparatus according to claim 6 ,
wherein difference amount X′ in the drawing direction between a center axis of the casting product press roll and a center axis of the backup roll arranged on the upstream side is set to sin 0.23°×(R w +R b )≤X′≤sin 5 °×(R w +R b ).