Metal deforming – By use of non-deforming work-gripping clamp and relatively... – With interrelated clamp closer and tool mover
Reexamination Certificate
1999-08-02
2001-10-02
Crane, Daniel C. (Department: 3725)
Metal deforming
By use of non-deforming work-gripping clamp and relatively...
With interrelated clamp closer and tool mover
C072S452900, C029S243580
Reexamination Certificate
active
06295858
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a hemming apparatus and a hemming process for bending a work such as a metal plate.
2. Description of the Related Art
Various hemming apparatuses which bend a work such as a door panel for automobile have been suggested. As shown in
FIG. 8
which illustrates the state before bending of a work, a hemming apparatus
80
possesses an upper mold
81
and a lower mold
82
and a work W is placed between these molds. The upper mold
81
possesses a driver cam
84
having a slant face
84
and a liner
83
. The lower mold
84
is composed of a hemming die
89
for fixing the work W that has already been subjected to a previous bending at the processing position WA, a hemming punch
88
for bending the processing position WA of the work W by compressing the position WA, a supporting pole for supporting the hemming punch
88
which can moves vertically, and a slide cam
85
possessing a slant face
85
a
which is come into contact with the slant face
84
a
provided via a moving mechanism which holds the supporting pole
87
and which can move horizontally.
Consequently, when the processing position WA of the work W is bent, by descending the upper
81
to bring the slant face
84
a
of the driver cam into contact with the slant face
85
a
of the slide cam
85
, the slant face
85
a
is compressed. The slide cam
85
is therefore, pushed toward the work W against the resilient force of the moving mechanism
85
and the hemming punch
88
comes to the processing position WA of the work W. By further descending the upper mold
81
, the liner
83
pushes the upper side of the hemming punch
88
to carry out the bending of the processing position WA of the work W.
The apparatus described above is disadvantageous in that the previous bending must be carried out by the use of another apparatus. Consequently, an apparatus as shown in
FIG. 7
has been suggested (
FIG. 7
illustrates the states after the previous bending and bending). To be specific, a hemming apparatus
90
is comprised of an upper mold
91
and a lower mold
92
. The upper mold
91
possesses a driver cam
94
having a slant face
94
a
and a liner
93
, whereas the lower mold
94
possesses a hemming die
99
for providing the work W and for supporting the position WA of the work W, a hemming punch for carrying out previous bending and bending of the processing position WA of the work W, a slide cam
96
for supporting and fixing the hemming punch
95
, a revolving cam
95
provided on the backside of the slide cam
95
, and a spring
97
which always apply the resilient force to the slide cam
96
in the backside direction.
Consequently, descending the upper mold
91
whereby the slant face
94
a
pushes the revolving cam
95
, the slide cam
96
goes forward against the spring
97
to previously bend the processing position WA of the work W by means of a previous bending slant face
98
a
of a hemming punch
98
. Subsequently, the hemming punch
98
is further pushed to go forward so that the face
98
b
to be bent placed on the lower side of the hemming punch
98
is positioned at the position where the bending of the processing position WA of the work W has been finished. The bending is carried out by pressing the face
98
b
by means of the liner
93
from the upper side of the hemming punch
98
.
However, the conventional hemming apparatuses have the following problems:
(1) In the case where there coexist linear portions and curved portions at an internal and external circumference portion of the site to be hemmed like window frame of the automobile, it is difficult for the conventional hemming apparatus to carry out bending of the linear portions and curved portions at the narrow position of the work. For this reason, in the conventional hemming apparatus, the bending of the curved portions at the internal circumference portion and the bending of the linear portions at the internal circumference portion are separately carried out. Because of carrying out two separate steps for bending the curved portions and the linear portions, the apparatus should become large as a whole.
(2) Since the hemming conventional apparatuses are separately composed of mounting portions for mounting slide cam and hemming punch, and since they have a large operation by the link mechanism, the rattled portions might be brought about, leading to compression loss and, thus, making it impossible to transmit push compression in an adequate manner. This also results in reduction in the bending precision.
(3) While the conventional hemming apparatuses are required to carry out bending at a compression timing suitable for the conditions of the work, the adjustment of the compression timing, the adjustment thereof is very serious because of complicated construction of the slide cam and other related parts. Moreover, the conventional hemming apparatuses have a large number of parts to be adjusted and, thus, the maintenance of the apparatus is very terrible.
(4) In the case where there are positions to be bent both at the external and internal circumference portions of the work, it is difficult for the conventional hemming apparatuses to secure the space for bending the internal circumference side of the work, making it difficult to design and manufacture the apparatus.
(5) In the case where there are positions to be bent both at the external and internal circumference portions of the work, the conventional hemming apparatuses cannot carry out the bending of the external circumference portion and that of the internal circumference portion at one step. Consequently, the balance between the compressions applied to the external and internal circumference portions of the work is not good and, thus, the deformation of the work might occur.
SUMMARY OF THE INVENTION
The present invention has been made in light of the above situations, and an object of the present invention is to provide a hemming apparatus and, which excels in workability even at a narrow portions, is capable of carrying out bending of linear and curved portion as well as the work at internal and external circumference sides at one step, has a reduced compression loss, excelling in processing precision, is easy to adjust stroke the hemming punch, to design and manufacture of the apparatus, and has good compression balance to the work, and a hemming process using the me.
The first aspect of the present invention is a hemming apparatus composed of opposing upper mold and lower mold;
said lower mold including
a hemming die for placing and supporting a work a hemming punch including previous bending portion and bending portion each placed adjacent to said heming die and carrying out bending of said work,
a slide cam for fixing and supporting said hemming punch and including a cam follower,
a moving mechanism for applying a resilient force to said slide cam in one direction and moving said slide cam to a prescribed distance,
a cushion holder for placing and fixing said slide cam and said moving mechanism, and
a movable supporting mechanism for supporting said cushion holder which can vertically move to a prescribed distance; and
said upper mold including
a presser for pressing and fixing the work on said hemming die,
driver cam for pushing said cam follower of said slide cam; and
a liner for pushing said hemming punch.
The second aspect of the present invention is a hemming apparatus composed of opposing upper mold and lower mold;
said lower mold including
a hemming die for placing and supporting a work
a hemming punch including previous bending portion and bending portion each placed adjacent to said heming die and carrying out bending of the internal circumference portions of said work,
a slide cam for fixing and supporting said hemming punch and including a cam follower,
a moving mechanism for applying a resilient force to said slide cam in one direction and moving said slide cam to a prescribed distance,
a cushion holder for placing and fixing said slide cam and said moving mechanism,
a movable supportin
Crane Daniel C.
Hirotec Corporation
Liniak Berenato Longacre & White
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