U.S. patent application number 11/997935 was filed with the patent office on 2009-05-14 for ring rolling from metal blanks.
This patent application is currently assigned to FORMFLO LIMITED. Invention is credited to Jason Michael Paul Hannis, Andrew J. L. Harrison, David Alexander Wilding.
Application Number | 20090120152 11/997935 |
Document ID | / |
Family ID | 34984219 |
Filed Date | 2009-05-14 |
United States Patent
Application |
20090120152 |
Kind Code |
A1 |
Harrison; Andrew J. L. ; et
al. |
May 14, 2009 |
RING ROLLING FROM METAL BLANKS
Abstract
A method of rolling a ring from a metal blank comprises mounting
the blank (2) on a mandrel (4) between two forming rolls (6)
located on opposite sides of the mandrel axis. A pair of lower
growth control rolls (12) are located below and with their axes
parallel to and on opposite sides of the mandrel axis (8), and a
pair of upper growth control rolls (16) are arranged above and with
their axes parallel and on opposite sides of the mandrel axis (8).
The spacing between the pair of upper growth control rolls is
different from that between the pair of lower growth control rolls.
As the ring is rolled, both the forming rolls and the growth
control rolls are engaged with it. In a modification of the method,
the upper growth control rolls are replaced by a single roll (20)
with its axis disposed directly over the mandrel axis.
Inventors: |
Harrison; Andrew J. L.;
(Bristol, GB) ; Hannis; Jason Michael Paul;
(Gloucestershire, GB) ; Wilding; David Alexander;
(Wiltshire, GB) |
Correspondence
Address: |
Levenfeld Pearlstein, LLC;Intellectual Property Department
2 North LaSalle, Suite 1300
Chicago
IL
60602
US
|
Assignee: |
FORMFLO LIMITED
Gloucestershire
GB
|
Family ID: |
34984219 |
Appl. No.: |
11/997935 |
Filed: |
August 4, 2006 |
PCT Filed: |
August 4, 2006 |
PCT NO: |
PCT/GB2006/002937 |
371 Date: |
June 26, 2008 |
Current U.S.
Class: |
72/87 |
Current CPC
Class: |
B21H 1/12 20130101 |
Class at
Publication: |
72/87 |
International
Class: |
B21D 19/04 20060101
B21D019/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 5, 2005 |
GB |
0516221.9 |
Claims
1. A method of rolling a ring from a metal blank, comprising
mounting the blank on a mandrel between two forming rolls located
on opposite sides of the mandrel axis, with a pair of lower growth
control rolls located below and with their axes parallel to and on
opposite sides of the mandrel axis, and a pair of upper growth
control rolls arranged above and with their axes parallel and on
opposite sides of the mandrel axis, wherein the spacing between the
pair of upper growth control rolls is different from the spacing
between the pair of lower growth control rolls; and rolling the
ring between the forming rolls with the growth control rings
engaging the ring.
2. A method according to claim 1 wherein the spacing between the
pair of upper growth control rolls is less than the spacing between
the pair of lower growth control rolls.
3. A method according to claim 1, wherein the lower growth control
rolls are located relative to the mandrel axis with their axes
disposed at an angle in the range 50.degree. to 70.degree. below
the horizontal plane containing the mandrel axis.
4. A method according to claim 3, when said angle is at least
60.degree..
5. A method according to claim 1, wherein the upper growth control
rolls are located relative to the mandrel axis with their axes
disposed at an angle in the range 50.degree. to 80.degree. above
the horizontal plane containing the mandrel axis.
6. A method according to claim 5, wherein said angle is in the
range 65.degree. to 70.degree..
7. (canceled)
8. A method according to claim 1, wherein the mandrel axis and the
axes of the forming rolls are in the same horizontal plane.
9. A method according to claim 1, wherein the mandrel axis is
disposed below a horizontal plane containing the forming roll
axes.
10. A method according to claim 9, wherein the mandrel axis is
disposed at an angle no greater than 10.degree. below the
horizontal plane containing the forming roll axes.
11. A method according to claim 10, wherein the angle is no greater
than 5.degree..
12. A method of rolling a ring from a metal blank, comprising
mounting the blank on a mandrel between two forming rolls located
on opposite sides of the mandrel axis, with a pair of lower growth
control rolls located below and with their axes parallel to and on
opposite sides of the mandrel axis, and a single upper growth
control roll arranged above and with its axis parallel and directly
over the mandrel axis, and rolling the ring between the forming
rolls with the growth control rings engaging the ring.
13. A method according to claim 12, wherein the lower growth
control rolls are located relative to the mandrel axis with their
axes disposed at an angle in the range 50.degree. to 70.degree.
below the horizontal plane containing the mandrel axis.
14. A method according to claim 13, when said angle is at least
60.degree..
15. A method according to claim 12, wherein the mandrel axis and
the axis of the forming rolls are in the same horizontal plane.
16. A method according to claim 12, wherein the mandrel axis is
disposed below a horizontal plane containing the forming roll
axes.
17. A method according to claim 16, wherein the mandrel axis is
disposed at an angle no greater than 10.degree. below the
horizontal plane containing the forming roll axis.
18. A method according to claim 17, wherein the angle is no greater
than 5.degree..
Description
[0001] This invention relates to the ring rolling of metal blanks.
The blanks are typically of standard steels such as wrought steels,
but could comprise other metals or alloys. They can be rolled to
form rings having many uses, particularly bearing components. The
invention may also be applied to powder metal blanks.
[0002] In rolling processes of the kind described above, the metal
blank is mounted on a mandrel located between two forming rolls
either side of the mandrel axis. Growth control rolls are disposed
above and below the mandrel axis to engage the blank as it turns
between the forming rolls. Four growth roll controls are used; one
directly above another between the mandrel axis and each forming
roll. This process has produced good results with very good quality
roundness in the final product. However, the process does generate
lobes. The present invention seeks to further reduce the generation
of lobes, and thereby further improve the roundness of the ring
rolled product. According to the invention, the growth control
rolls are arranged above, below and on either side of the mandrel
axis to generate a less symmetric pattern of forces acting on the
ring blank with more of the horizontal forces being resolved
between the upper or the lower growth control rolls and the forming
rolls. The preferred arrangement has the pair of upper growth
control rolls with their axes parallel to but closer than those of
the lower rolls. However, for some applications of the invention
the lower pair of growth control rolls can be closer together than
the upper pair.
[0003] In the method of the invention the upper and lower growth
control rolls will normally be arranged with their axes equidistant
on either side of the vertical plane containing the mandrel axis.
In one variant of the invention, the two upper growth controls can
be replaced by a single growth control with its axis disposed
directly over the mandrel axis. In this variant, the upper growth
control does of course apply only vertical forces to the ring blank
with all the horizontal forces being resolved between the lower
growth control rolls and the forming rolls. The disposition of the
growth control rolls is preferably selected to minimise the length
of unsupported blank between peripherally adjacent rolls (forming
rolls and growth control rolls).
[0004] In the methods of the invention, the mandrel axis and the
forming rolls are in the same horizontal plane. However, in some
applications of the invention there can be some benefit in locating
the mandrel axis below the axes of the forming rolls so that there
is a vertical component of the forces between the forming rolls and
the ring blank.
[0005] The invention will now be described by way of example and
with reference to the accompanying schematic drawings in which:
[0006] FIG. 1 shows a cross-section through ring rolling apparatus
adapted to practice the method of the invention; and
[0007] FIG. 2 shows an alternative apparatus to that of FIG. 1 in
which the upper growth controls are replaced by a single roll.
[0008] As shown in FIG. 1 a metal blank (2) is mounted on a mandrel
(4) disposed between two forming rolls (6). The axis (8) of the
mandrel (4) is located below the horizontal plane containing the
axes (10) of the forming rolls, the line between the axis (8) and
each forming roll axis (10) subtending an angle .beta. with the
horizontal. Angle .beta. is normally no more than 10.degree., and
typically will be no more than 5.degree.. Effective performance has
been achieved with angle .beta. at around 1.degree..
[0009] Two lower growth control rolls (12) are disposed beneath the
mandrel (4) to engage the metal blank (2) from below. The rolls
(12) are arranged symmetrically on either side of the vertical
plane containing the mandrel axis (8); equally spaced from that
vertical plane. The rolls (12) are mounted on a framework (14)
enabling their spacing to be adjusted. It will be appreciated that
the diameter of the lower growth control rolls may need to vary
depending upon the spacing between them, to avoid interference with
either each other or the forming rolls. The critical factor is of
course the line of engagement with the blank on the mandrel, and
the angle .theta. subtended between the line of engagement and the
mandrel axis and the horizontal. This angle .theta. is typically in
the range of 50.degree. to 70.degree., and normally at least
60.degree..
[0010] Two upper growth control rolls (16) are mounted in a
framework (18) over the mandrel axis for engaging the blank (2)
from above. These rolls (16) are located closer to each other than
are the lower growth control (12) but once again their spacing can
be altered by movement of their axes in the framework (18). The
rolls (16) are also arranged symmetrically on either side of the
vertical plane containing the mandrel axis, and the angle .theta.'
subtended by the line of engagement of the roll (16) and the blank
(2) and the mandrel axis relative to the horizontal will of course
be greater than the angle .theta. defined in the location of the
lower growth controls. The angle .theta.' is typically in the range
of 50.degree. to 80.degree., normally in the range 65.degree. to
70.degree..
[0011] As noted above different sized growth control rolls can be
used depending upon the geometry of the desired roll arrangement
and of course the size of the ring to be rolled on the forming
rolls. Because of the forces involved, the diameter of the growth
control rolls should be as much as the geometry allows. The
location of the growth control rolls relative to the blank is
normally selected such that the spacing between the lines of
engagement of the upper rolls (16) is substantially equal to the
spacing between each upper roll and the line of engagement of the
adjacent forming roll (6). The lower growth control rolls (12) are
located in a similarly symmetric arrangement.
[0012] FIG. 2 shows a modification of the arrangement in FIG. 1 in
which the upper growth control rolls (16) are replaced by a single
roll (20). In other respects the arrangement of forming and growth
control rolls is the same as in FIG. 1.
* * * * *