Plastic article or earthenware shaping or treating: apparatus – Stock pressurizing means operably associated with downstream... – Including auxiliary shaping means associated with molding...
Reexamination Certificate
1999-10-29
2001-06-19
Heitbrink, Tim (Department: 1722)
Plastic article or earthenware shaping or treating: apparatus
Stock pressurizing means operably associated with downstream...
Including auxiliary shaping means associated with molding...
C425S38200R, C425S462000, C425S463000
Reexamination Certificate
active
06247915
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a die for manufacturing honeycomb bodies used for extruding honeycomb structural bodies.
2. Description of Related Art
Generally, various kinds of dies for manufacturing honeycomb bodies are known, which comprise; a die main body including batch supply holes which are opened to a backside surface of the die, slit channels which are communicated with the batch supply holes and are opened to a foreside surface of the die and a taper worked portion which is formed by working an outer peripheral portion of the foreside surface of the die in a taper manner; and a control plate arranged at a portion opposed to the taper worked portion.
FIG. 3
is a schematic view showing one embodiment of a known die for manufacturing honeycomb bodies. In the embodiment shown in
FIG. 3
, a die
51
for manufacturing honeycomb bodies comprises a die main body
52
and a control plate
53
. The die main body
52
has a disk-shape and comprises batch supply holes
61
which are opened to its backside surface (lower surface (not shown) in
FIG. 3
) and slit channels
62
which are opened to its foreside surface (upper surface in FIG.
3
). The slit channels
62
have a crisscross shape at the foreside surface of the die main body
52
, and the batch supply holes
61
are communicated with alternate intersection points. An outer peripheral portion of the die main body
52
is worked into a taper shape to form a taper worked portion
63
. The control plate
53
is connected to the die main body
52
via a spacer
64
in such a manner that one surface
53
a
is opposed (parallel in
FIG. 3
) to the taper worked portion
63
.
In the die
51
for manufacturing honeycomb bodies having the construction shown in
FIG. 3
, a ceramic batch for example is supplied from the batch supply holes
61
which are opened to the backside surface of the die
51
, and the thus supplied ceramic batch is extruded from the slit channels
62
which are opened to the foreside surface of the die
51
, so as to obtain a honeycomb structural body. Then, it is possible to reduce an inward batch stress when an outer wall is formed and to prevent a collapsing of outer cells i.e. a generation of wrinkle portions in the honeycomb structural body by forming the taper worked portion
63
at the outer peripheral portion of the die main body
52
and by arranging the control plate
53
at a portion opposed to the taper worked portion
63
.
However, if a thin wall honeycomb structural body having a thin rib thickness, which is required recently, is to be formed, an isostatic strength of the honeycomb structural body become smaller correspondingly since the rib thickness is thin. As a result, there is a drawback such that it is necessary to take care of a handling of the honeycomb structural body. In order to eliminate the drawback mentioned above, it is thinkable in the die
51
for manufacturing honeycomb bodies having the construction shown in
FIG. 3
that a space between the taper worked portion
63
and the control plate
53
is widened by making a thickness of the spacer
64
thick so as to obtain a honeycomb structural body having a thick outer wall. However, if the thick outer wall is to be formed in this manner, a batch is supplied in excess at this portion to an extent such that the outer wall becomes thicker. In addition, when the outer wall is formed, a pressure of the batch moving between the taper worked portion
63
and the control plate
53
becomes large and is applied in an inward direction of the honeycomb structural body. As a result, there is a drawback such that outer ribs are deformed and a collapsing of the outer cells i.e. a wrinkle portion is generated.
SUMMARY OF THE INVENTION
An object of the present invention is to eliminate the drawbacks mentioned above and to provide a die for manufacturing honeycomb bodies in which a generation of wrinkle portions in a honeycomb structural body after forming can be prevented and a thickness of an outer wall can be thicker.
According to the invention, a die for manufacturing honeycomb bodies including batch supply holes which are opened to a backside surface of the die, slit channels which are communicated with the batch supply holes and are opened to a foreside surface of the die and a taper worked portion which is formed by working an outer peripheral portion of the foreside surface of the die in a taper manner, comprises at least one cut-out portion formed to the taper worked portion of the outer peripheral portion.
In the present invention, it is possible to reduce a pressure of the batch moving between the taper worked portion and the control plate by arranging the cut-out portion to the taper worked portion of the outer peripheral portion. As a result, it is possible to reduce a pressure applied to the rib even if the outer wall is designed thick, and thus it is possible to obtain a ceramic honeycomb structural body in which a generation of wrinkle portions in a honeycomb structural body after forming can be prevented and a thickness of an outer wall can be thicker. In the case that the cut-out portion is constructed in a longitudinal cross section by a horizontal surface along a radial direction of the die and a vertical surface along an axial direction of the die, or, in the case that the taper worked portion has an angle of 45° with respect to a surface along a radial direction of the die, and the horizontal surface and vertical surface constituting said cut-out portion are 0.2-1.0 mm in a longitudinal cross section, these cases are preferred since a function of the cut-out portion can be exerted effectively.
REFERENCES:
patent: 4178145 (1979-12-01), Hamamoto et al.
patent: 4242075 (1980-12-01), Higuchi et al.
patent: 4298564 (1981-11-01), Higuchi et al.
patent: 4550005 (1985-10-01), Kato
patent: 5552102 (1996-09-01), Krangle
patent: 5876804 (1999-03-01), Kodama et al.
patent: 5942260 (1999-08-01), Kodama et al.
Heitbrink Tim
NGK Insulators Ltd.
Parkhurst & Wendel LLP
LandOfFree
Die for manufacturing honeycomb bodies does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Die for manufacturing honeycomb bodies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Die for manufacturing honeycomb bodies will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2482687