U.S. patent application number 10/647473 was filed with the patent office on 2004-07-29 for method of making rim having opposite hollow flanges.
Invention is credited to Motode, Katsuhiro, Sato, Junichi.
Application Number | 20040143968 10/647473 |
Document ID | / |
Family ID | 32588706 |
Filed Date | 2004-07-29 |
United States Patent
Application |
20040143968 |
Kind Code |
A1 |
Sato, Junichi ; et
al. |
July 29, 2004 |
Method of making rim having opposite hollow flanges
Abstract
Disclosed is a method of making a rim having hollow flanges
formed on its opposite annular edges. It comprises the steps of:
cutting an elongated metal band of a fixed width to provide metal
strips of a predetermined length; rolling a selected metal strip
into a ring; welding the opposite ends of the ring; curling each
annular edge of the ring outward; and roll-forming the main annular
part to define a well along the center line of the main annular
part. The method further comprises the steps of: bending the
opposite bead areas toward the center well; closing the gap between
each curl edge and the counter bead area; and unbending the
opposite bead areas into the final rim shape.
Inventors: |
Sato, Junichi; (Ishikawa,
JP) ; Motode, Katsuhiro; (Ishikawa, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
32588706 |
Appl. No.: |
10/647473 |
Filed: |
August 26, 2003 |
Current U.S.
Class: |
29/894.354 |
Current CPC
Class: |
Y10T 29/49531 20150115;
B21D 53/30 20130101 |
Class at
Publication: |
029/894.354 |
International
Class: |
B21K 001/38 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 27, 2003 |
JP |
2003-17272 |
Claims
What is claimed is:
1. A method of making a rim having hollow flanges formed on its
opposite annular edges comprising the steps of: cutting an
elongated metal band of a fixed width to provide metal strips of a
predetermined length, rolling a selected metal strip of the
predetermined length into a ring; welding the opposite ends of the
ring; curling each annular edge of the ring outward; and rolling
the main annular part of the ring into a required shape.
2. A method of making a rim having hollow flanges formed on its
opposite annular edges according to claim 1, wherein the opposite
ends of the ring are flash butt-welded; and the burr or flash is
removed from the welded part of the ring.
3. A method of making a rim having hollow flanges formed on its
opposite annular edges according to claim 2, wherein the main
annular part of the ring is sandwiched between inner and outer
rolls, and is roll-formed to define a well along the center line of
the main annular part.
4. A method of making a rim having hollow flanges formed on its
opposite annular edges according to claim 3, wherein it further
comprises the steps of: bending the opposite bead areas toward the
center well; closing the gap between each curl edge and the bead
area; and unbending the opposite bead areas into the final rim
shape.
5. A method of making a rim having hollow flanges formed on its
opposite annular edges according to claim 3, wherein it further
comprises the steps of: closing the gap between each curl edge and
the counter bead area; and raising each closed curl edge into the
final rim shape.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method of making a rim
having opposite hollow flanges formed on its circumference.
[0003] 2. Related Art
[0004] Almost all rims for motorcycles are of aluminum, but steel
rims are still used widely. A variety of steel rims used are
different in cross sections. One of the principal steel rims is
called "W"-type rim. It has two opposite hollow flanges "a" formed
on its annular circumference, as shown in FIG. 5(a). The tyre bead
is fitted on the hollow flanges "a" of the rim.
[0005] Another principal steel rim is called DC type rim. It has
opposite projecting flanges "b" rising from the outer edges of the
annular circumference, as shown in FIG. 5(b). This flange "b" of
the DC type rim has a reduced strength, compared with the hollow
flanges "a" of the "W"-type rim. Also, the strength and rigidity of
the whole rim body is low, compared with the "W"-type rim.
[0006] Advantageously DC type rims can be made by a multi-stage
roll system. Small-sized "W-type rims however, cannot be made by
such a multi-stage roll system; their hollow flanges cannot be
correctly shaped. Referring to FIG. 6, a strip of steel needs to be
partly worked by a series of rolls sequentially (15 to 20 steps)
until it has been given a required shape in cross-section. The
semi-final shaped object is curved to be given a required
curvature, and then the ring is cut.
[0007] The cut ends are flash butt-welded to provide an annular
rim. The annular rim is corrected in roundness, followed by five to
six steps including removing the burr or flash from the welded cut.
Then, the whole rim body is polished, and nipple bosses and holes
are formed in the polished rim to stretch the spokes across the
ring. Finally the rim is subjected to the surface treatment.
[0008] As described above, a strip of steel needs to be subjected
to the 15 to 20 forming steps to be given the cross-section as
shown in FIG. 5(a). The so-shaped strip of steel has a hollow
flange "a" formed on its annular circumference. If the flange is
relatively large in width, and if the final annular product is
relatively small in size, the shaped steel strip cannot be rolled
into the rim without twisting and deforming its hollow flange.
[0009] Also disadvantageously the burr-removing-and-polishing of
the welded cut ends of the rim cannot be automatized. This step
must be performed manually, and therefore, the manufacturing cost
increases, and the product quality cannot be guaranteed to be
same.
[0010] One object of the present invention, therefore, is to
provide a method of, with precision and efficiency, making a
small-sized rim having a hollow flange formed on its annular
circumference. The method can be equally used in making such rims
of steel and aluminum.
SUMMARY OF THE INVENTION
[0011] A method of making a rim having hollow flanges formed on its
opposite annular edges according to the present invention comprises
the steps of:
[0012] cutting an elongated metal band of a fixed width to provide
metal strips of a predetermined length; rolling a selected metal
strip of the predetermined length into a ring; welding the opposite
ends of the so rolled metal strip, curling each annular edge of the
ring diametrically outward; and rolling the main annular part of
the ring into a required shape. The required shape is a well
defined at the center of the main annular part. The method further
comprises the steps of bending bead areas bordering the center
well; rolling each curled edge to form the hollow flange; and
unbending the opposite bead areas. Otherwise, it further comprises
the steps: rolling each curled edge to form the hollow flange; and
raising each hollow flange to give the final rim shape to the
ring.
[0013] The opposite ends of the rolled steel strip can be welded
easily for instance by flash butt-welding; the required welding is
linear along the abutting line, and can be automatized. Friction
welding can be used, also.
[0014] Each annular edge of the ring can be curled diametrically
outward by pushing the ring on the opposite sides with conical
tools. One to four roll-forming steps follow, much smaller in
number than the conventional method.
[0015] The method according to the present invention can be used in
making small-sized rims of relatively large width. Needless to say,
it can be used in making large-sized rims of relatively small
width.
[0016] Other objects and advantages of the present invention will
be understood from the following description of one preferred
embodiment, which is shown in accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0017] FIG. 1(a) is a perspective view of an elongated length of
steel; FIG. 1(b) is a similar perspective view of a predetermined
length of steel cut and separated from the belt-like elongation of
FIG. 1(a); FIG. 1(c) is side and front views of the open ring; and
FIG. 1(d) is side and front views of the closed ring;
[0018] FIG. 2(a) is a sectional view of the edge-curled ring taken
along a selected diameter of the ring whereas FIG. 2(b) is a front
view of the edge-curled ring;
[0019] FIGS. 3(a) to 3(e) illustrate how an edge-curled ring can be
roll-formed sequentially;
[0020] FIGS. 4(a) to 4(c) illustrate how another edge-curled ring
can be roll-formed sequentially;
[0021] FIGS. 5(a) and 5(b) illustrate conventional rims; and
[0022] FIG. 6 shows a series of steps for making a hollow-flanged
rim according to the conventional method.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0023] Referring to FIG. 1(a), a coiled band steel 1 having a fixed
width "M" and thickness "T" is prepared. When aluminum rims are
made, coiled band aluminum is prepared.
[0024] Referring to FIG. 1(b), the band steel 1 is cut to provide
steel strips of a predetermined length "L", which is equal to the
circumference of the rim to be made.
[0025] Referring to FIG. 1(c), a selected steel strip of the
predetermined length is bent into a ring with a bender. As shown,
the ring has an aperture 2 between the opposite cut ends.
[0026] Referring to FIG. 1(d), the open ring is closed, and the
abutting ends 3a and 3b are flash butt-welded. The burr or flash is
removed from the welded portion 4 to be flush with the inner, outer
circumferences 5 and 6, and with the opposite sides 7. For
instance, the burr or flash is removed by shaper tools while around
the welded portion 4 is clamped.
[0027] Referring to FIG. 2, after finishing the process at the
welded portion 4 as above, each annular edge of the ring 8 is
curled by inserting a conical tool into the ring 8 on each open
side, forming the curl 12 on each open side. Then, the edge-curled
ring 9 is shaped by a series of rolls, as shown in FIG. 3.
[0028] Specifically the edge-curled ring 9 is roll-formed to define
a well 10 at its center (see FIG. 3(a)) as follows: the main
annular part of the edge-curled ring 9 is sandwiched between the
inner and outer rolls, and the edge-curled ring 9 is rotated to
form the well 10 on its main annular part.
[0029] The so shaped ring 9 is roll-formed to bend the opposite
bead areas 11 toward the center well 10 (see FIG. 3(b)).
[0030] The ring 9 is roll-formed to make the free edge of each curl
closer to the bead area 11, thus substantially reducing the gap 13
between the bead area 11 and the curl edge (see FIG. 3(c)).
[0031] The remaining gap 13 is closed to define the opposite hollow
flanges 15 (see FIG. 3(d)). Each flange 15 has a hollow space
14.
[0032] The step of bending the opposite bead areas 11 toward the
center well 10 (FIG. 3(b)) is preliminary for defining the hollow
flanges 15. After finishing the roll forming of the flanges 15, the
bead areas 11 are unbent to their original flat shapes (FIG.
3(e)).
[0033] As may be understood from the above, the ring 8 is not
directly provided with the hollow flanges, which can be formed via
the preparatory step of curling the opposite annular edges. The
steps (a) and (c) encircled with broken lines in FIG. 3 can be
omitted.
[0034] FIG. 4 shows another manner in which a rim having hollow
flanges formed on its opposite annular edges can be made according
to the present invention.
[0035] Specifically the edge-curled ring 9 is roll-formed to define
a well 10 in the center of the main annular part (see Fig.
(a)).
[0036] The so shaped ring 9 is roll-formed to define the opposite
hollow flanges 16 (see FIG. 4(b)). As seen from the drawing, the
opposite hollow flanges 16 are inclined outward to be apart from
the opposite bead areas 11, which border the center well 10.
[0037] Finally, the opposite inclined hollow flanges 16 are raised
to be in normal positions (FIG. 4(c)). The step (a) encircled with
broken lines in FIG. 4 can be omitted.
[0038] Nipple bosses and holes are formed on the rim thus provided
to stretch wire spokes to form a wheel with use of the rim.
Otherwise, plate spokes are welded to the inner circumference of
the rim.
[0039] Rims made according to the present invention can be used for
the wheels of motorcycles and other cars such as buggies.
[0040] As may be understood from the above, the pre-edge-curling of
the rolled steel strip permits opposite hollow flanges to be formed
with precision no matter how wide the rim may be, and no matter how
small the rim diameter may be. Also advantageously the number of
steps required for forming rims is significantly smaller than the
conventional method, and accordingly the manufacturing cost can be
reduced. Removal of the burr or flash from the linear welded part
of the ring is easy.
* * * * *