Metal fusion bonding – Process – With shaping
Reexamination Certificate
2000-11-06
2004-08-03
Stoner, Kiley (Department: 1725)
Metal fusion bonding
Process
With shaping
C228S017500, C072S166000
Reexamination Certificate
active
06769597
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bent work to be used as a bearing-receiving unit and the like for construction machinery, a bending method for manufacturing the same, and a bending device to be used therefor.
2. Description of the Related Art
Generally, construction machinery such as a hydraulic shovel includes, as shown in
FIG. 19
, a lower moving unit
51
and an upper rotational unit
52
rotatably supported by the lower moving unit
51
. The upper rotational unit
52
is rotatably mounted on the lower moving unit
51
via a bearing-receiving unit
53
fixed to the lower moving unit
51
and a bearing (not shown) fixing to the bearing-receiving unit
53
. As shown in
FIGS. 20
to
22
, the bearing-receiving unit
53
includes a cylindrical part
54
, and a flange
55
protruding toward the outside or outwardly at the upper end of the cylindrical part
54
. The flange
55
is provided with a number of through-holes
55
a
(four through-holes
55
a
are shown in
FIGS. 20 and 21
) formed in the flange
55
for receiving bolts (not shown) for fixing the bearing. The bearing-receiving unit
53
must have a strength sufficient to support the bearing thereon. The cylindrical part
54
and the flange
55
are made of a thick steel plate (the cylindrical part
54
is thinner than the flange
55
).
Hitherto, the bearing-receiving unit
53
has been manufactured in a manner such that a first member
57
made of a thick steel plate bent in a cylindrical shape and a second member
58
made of a thick steel plate bent in an annular shape are welded to each other (see FIGS.
23
and
24
). In
FIG. 24
, welds
59
are shown. In
FIG. 23
, the first and second members
57
and
58
are welded to each other butt-welds
57
a
and
58
a
, respectively. A roll-forming method for manufacturing the first and second members
57
and
58
, as shown in
FIGS. 25
to
29
, is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 7-314050.
In the roll-forming method, four rolls, which are a pair of upper and lower press-rollers
61
and
62
, an inlet assist roller
63
disposed at the inlet side, and an outlet assist roller
64
disposed at the outlet side, are used. A metallic plate
65
is placed in a working position, as shown in FIG.
25
. The upper roller
61
moves downward to be pressed to the lower roller
62
, thereby pressing so as to hold the metallic plate
65
, as shown in FIG.
26
. The upper and lower rollers
61
and
62
as a unit pivot in a direction moving the metallic plate
65
away from the inlet assist roller
63
, thereby bending the metallic plate
65
at an end thereof, as shown in FIG.
27
. The outlet assist roller
64
moves so as to come into contact with the transferred metallic plate
65
at the end thereof, and the upper and lower rollers
61
and
62
are restored to the original position while the upper and lower rollers
61
and
62
rotate so as to transfer the metallic plate
65
toward the outlet side, as shown in FIG.
28
. Then, the upper and lower rollers
61
and
62
and the outlet assist roller
64
bend the metallic plate
65
, as shown in FIG.
29
. The metallic plate
65
is welded at ends thereof (not shown), whereby cylindrical works such as the first and second members
57
and
58
are formed.
However, when the individually manufactured first and second members
57
and
58
are welded so as to form an integral structure, considerable labor and time are required in processes of setting the first and second members
57
and
58
for welding, and sufficient strength cannot be obtained. In addition, the appearance is not good due to the welds of the first and second members
57
and
58
being exposed. Moreover, two sets of bending devices are required because the first and second members
57
and
58
are individually manufactured. Therefore, forging may be used for forming the bearing-receiving unit
53
in an integral structure. However, a forging device is expensive, thereby increasing the cost.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a low-cost bent work and bending method and a bending device therefor, in which a bent work such as a bearing-receiving unit can be manufactured in an integral structure, thereby omitting welding processes and improving the strength and the appearance of the work, and the bent work can be manufactured by one bending device at low cost.
To these ends, according to a first aspect of the present invention, a bent work is obtained by a method comprising the steps of preparing a belt-shaped thick steel material having an L-shaped cross-section; forming a cylinder by bending the belt-shaped thick steel material having an L-shaped cross-section; and welding ends of the belt-shaped thick steel material formed into the cylinder to each other.
According to a second aspect of the present invention, a bending method comprises the steps of providing a belt-shaped thick steel material having one of an L-shaped cross-section and a U-shaped cross-section; and forming the material into a cylinder by using a center roller to be driven to rotate which is positioned and fixed in a predetermined position and a pair of bending rollers to be driven to rotate which is disposed opposing the center roller at one side of the center roller, movable toward and away from the center roller. The belt-shaped thick steel material having one of an L-shaped cross-section and a U-shaped cross-section is bent by being transferred between the center roller and the pair of bending rollers.
According to a third aspect of the present invention, a bending device, for forming a cylinder by bending a belt-shaped thick steel material, comprises a center roller to be driven to rotate positioned and fixed in a predetermined position; and a pair of bending rollers to be driven to rotate disposed opposing the center roller at one side of the center roller, movable toward and away from the center roller, the belt-shaped thick steel material being bent by being transferred between the center roller and the pair of bending rollers. The center roller is provided with an annular recess formed therein around the center roller. The pair of bending rollers are respectively provided with annular convex portions formed thereon around the bending rollers. The convex portions can be inserted in the annular recess of the center roller at a predetermined position of the annular recess of the center roller. The belt-shaped thick steel material having one of an L-shaped cross-section and a U-shaped cross-section is transferred between the center roller and the pair of bending rollers in a manner such that a concave portion of the belt-shaped thick steel material having one of an L-shaped cross-section and a U-shaped cross-section faces toward the outside at the annular recess of the center roller and the convex portions of the pair of bending rollers are positioned in the concave portion of the belt-shaped thick steel material having one of an L-shaped cross-section and a U-shaped cross-section.
According to the present invention, the bent work is formed by bending a belt-shaped thick steel plate having an L-shaped cross-section and welding the steel plate at the ends thereof, thereby forming a cylinder. The cylinder having an L-shaped section can be manufactured in one bending process. It is not necessary to manufacture first and second members
57
and
58
individually, and to combine the first and second members
57
and
58
by welding, as in a known technology. The welding process of assembling the first and second members
57
and
58
can be omitted, according to the present invention. The strength of the bent work according to the present invention is greater than that of the known work because the bent work according to the present invention is integrally formed. The appearance of the bent work is superior to that of the known work in which the welding points of the first and second members
57
and
58
are exposed. The bent work acco
Armstrong Kratz Quintos Hanson & Brooks, LLP
Johnson Jonathan
Miharu Co., Ltd.
Stoner Kiley
LandOfFree
Bent work and bending method and bending device used therefor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bent work and bending method and bending device used therefor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bent work and bending method and bending device used therefor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3269288