Inner surface regulation tool, plug, mandrel, hot rolling mill, press piercing machine, and drawing machine

Patent metadata

Field	Value
Publication number	US-9486845-B2
Application number	US-201314410162-A
Country	US
Kind code	B2
Filing date	Aug 22, 2013
Priority date	Aug 24, 2012
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

An inner surface regulation tool includes a mandrel, a plug which is detachably connected to the mandrel, and a connection member which connects the plug and the mandrel by a magnetic force. One of the plug and the mandrel includes a column-shaped portion which extends in an axial direction of the one, and the other of the plug and the mandrel includes a joining hole which extends in an axial direction of the other and into which the column-shaped portion is inserted. In addition, the connection member is a permanent magnet which is attached to at least one of the column-shaped portion and the joining hole.

First claim

The invention claimed is:

1. An inner surface regulation tool, comprising:
a mandrel;
a plug which is detachably connected to the mandrel; and
a connection member which connects the plug and the mandrel by a magnetic force,
wherein one of the plug and the mandrel includes a column-shaped portion which extends in an axial direction of the one, and the other of the plug and the mandrel includes a joining hole which extends in an axial direction of the other and into which the column-shaped portion is inserted, and
wherein the connection member is a permanent magnet which is attached to at least one of the column-shaped portion and the joining hole, and
wherein the connection member is fitted to a groove which is formed on at least one of an outer circumferential surface of the column-shaped portion or an inner circumferential surface of the joining hole so that a gap is generated between a surface of the connection member and an opening surface of the groove, or the connection member is fitted to a mounting hole which is formed on at least one of a rear end surface of the column-shaped portion or a bottom surface of the joining hole so that a gap is generated between a surface of the connection member and an opening surface of the mounting hole.

2. The inner surface regulation tool according to claim 1 ,
wherein cross-sectional shapes of the column-shaped portion and the joining hole are circles.

3. The inner surface regulation tool according to claim 1 or 2 ,
wherein when the connection member is attached to the outer circumferential surface of the column-shaped portion, the joining hole is formed in a ferromagnetic body which is at least a portion of the other of the plug and the mandrel, and
wherein when the connection member is attached to the inner circumferential surface of the joining hole, at least the column-shaped portion of one of the plug and the mandrel is formed by a ferromagnetic body.

4. A hot rolling mill for making a seamless metal pipe, comprising:
a pair of inclined rolls; and
an inner surface regulation tool according to claim 1 or 2 .

5. A press piercing machine for making a seamless metal pipe, comprising:
a container; and
an inner surface regulation tool according to claim 1 or 2 .

6. A drawing machine for making a seamless metal pipe, comprising:
a tapered die;
a chuck; and
an inner surface regulation tool according to claim 1 or 2 .

7. A plug which is detachably connected to a mandrel, comprising:
a column-shaped portion or a joining hole which extends in an axial direction of the plug; and
a connection member which connects the mandrel and the plug by a magnetic force,
wherein the connection member is a permanent magnet which is attached to the column-shaped portion or the joining hole, and
wherein the connection member is fitted to a groove which is formed on at least one of an outer circumferential surface of the column-shaped portion or an inner circumferential surface of the joining hole so that a gap is generated between a surface of the connection member and an opening surface of the groove, or the connection member is fitted to a mounting hole which is formed on at least one of a rear end surface of the column-shaped portion or a bottom surface of the joining hole so that a gap is generated between a surface of the connection member and an opening surface of the mounting hole.

8. The plug according to claim 7 ,
wherein a cross-sectional shape of the column-shaped portion or the joining hole is a circle.

9. A mandrel which is detachably connected to a plug, comprising:
a column-shaped portion or a joining hole which extends in an axial direction of the mandrel; and
a connection member which connects the mandrel and the plug by a magnetic force,
wherein the connection member is a permanent magnet which is attached to the column-shaped portion or the joining hole, and
wherein the connection member is fitted to a groove which is formed on at least one of an outer circumferential surface of the column-shaped portion or an inner circumferential surface of the joining hole so that a gap is generated between a surface of the connection member and an opening surface of the groove, or the connection member is fitted to a mounting hole which is formed on at least one of a rear end surface of the column-shaped portion or a bottom surface of the joining hole so that a gap is generated between a surface of the connection member and an opening surface of the mounting hole.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Yamane Kouji
• Shimoda Kazuhiro
• Yamakawa Tomio
• Inoue Yuji

Classifications

• B21B25/06 Primary

  Interchanging mandrels {, fixing plugs on mandrel rods or cooling during interchanging mandrels (separating tubes from mandrels B21C45/00)} · CPC title

• B21C25/04

  Mandrels · CPC title

• B21J5/10

  Piercing billets (in combination with extrusion B21C23/00) · CPC title

• B21B25/00 Primary

  Mandrels for metal tube rolling mills, e.g. mandrels of the types used in the methods covered by group B21B17/00; Accessories or auxiliary means therefor {; Construction of, or alloys for, mandrels or plugs} · CPC title

• B21C3/16

  Mandrels; Mounting or adjusting same · CPC title