JP4627372B2 - Die for extrusion molding of honeycomb structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a die jig for extrusion molding of a honeycomb structure.
[0002]
[Prior art]
Conventionally, as shown in FIG. 8, a die jig 20 used for extrusion molding of a ceramic honeycomb structure has a die 1 and an opening 10 corresponding to the outer size and shape of the honeycomb structure to be extruded. And holding a base presser jig 21, which includes a plate-like part 21 a that presses the surface of the base 1 and a cylindrical part 21 b that is formed integrally with or separately from the plate-like part 21 a, and press-fit And a die holder 4 for receiving the dredged clay.
[0003]
In the base jig 20 having such a configuration, it is desirable that the thickness of the base 1 to be used is as thin as possible so that the base 1 is not broken by the extrusion earth pressure. If the thickness of the base 1 is increased, the strength is increased, but the pressure resistance due to friction between the slit 6 and the back hole 7 and the clay is increased, and there is a problem that the pressure of the clay must be increased. In addition, slit processing and back hole processing become difficult, and it takes a long time, resulting in a problem of high cost. Conventionally, carbon steel having excellent rigidity is used. As shown in FIG. 7, the base 1 has a two-layer structure, the slit layer 13 for forming the thin wall portion of the honeycomb structure is formed on the surface side, and the slit 6 is formed on the back side. A base 1 having a structure in which a back hole layer 14 in which a back hole 7 is formed is provided and the slit layer 13 is reinforced by the back hole layer 14 is used.
[0004]
In the base 1 having such a structure, a base 1 that is further thinned without destroying the base 1 is desired. By reducing the thickness of the base 1, the slit processing of the base 1 becomes easy, the processing time is shortened, and the manufacturing cost of the base 1 is reduced. It is also possible to reduce the pressure of the clay.
[0005]
[Problems to be solved by the invention]
Accordingly, the present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a die jig for extrusion molding of a honeycomb structure that can reduce the thickness of the die.
[0006]
[Means for Solving the Problems]
That is, according to the present invention, a plate-shaped die for extruding a honeycomb structure, a front plate portion that has an opening provided to face the die and presses the surface of the die, and the front plate portion And a pressing jig comprising a cylindrical body portion that is in contact with the peripheral end surface and the inner peripheral surface of the base, and a die holder that holds the pressing jig and receives the press-fitted clay. In the honeycomb structure extrusion molding die configured as described above, when the clay press-fitted into the die holder is extruded from the die as a honeycomb structure while pressing the die, the peripheral portion of the die is A honeycomb structure extrusion molding characterized in that a bending allowance portion capable of being bent in the extrusion direction of the clay by pressurization of the clay is a space provided between the front plate portion and the peripheral edge portion of the base. A base jig is provided.
[0007]
In this invention, the said bending | flexion permission part is the space part formed by the groove process of the back surface of the front plate part of the said pressing jig, or it is a notch space part formed in the peripheral part surface of the said nozzle | cap | die. Is preferred.
[0008]
Moreover, in this invention, it is preferable to provide a convex part in the back surface of the front board part of the said pressing jig, and to hold down the surface of the said nozzle | cap | die with this convex part.
Furthermore, the convex portion can be separated from the pressing jig. Furthermore, this separate convex part can be used as an adhesive tape.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the following, embodiments of the honeycomb structure extrusion molding die jig of the present invention will be specifically described. However, the present invention is not limited to these, and departs from the scope of the present invention. Insofar as various changes, modifications and improvements can be made based on the knowledge of those skilled in the art.
[0010]
FIG. 1 is a cross-sectional view showing an embodiment of a die for extrusion molding of a honeycomb structure of the present invention. The honeycomb structure extrusion molding die jig 5 includes a disk-shaped die 1 for extruding the honeycomb structure and an opening provided corresponding to the outer size and shape of the honeycomb structure extruded into a cylindrical shape. A front plate portion 2a having a portion 10 and pressing the surface side of the base 1; a cylindrical body portion 2b formed integrally with the front plate portion 2a and abutting on the peripheral edge surface 12 of the base 1 on the inner peripheral surface; And a die holder 4 for holding the pressing jig 2 and receiving the press-fit clay.
[0011]
In the honeycomb structure extrusion molding die 5, when the clay pressed into the die holder 4 is extruded from the die 1 as a honeycomb structure while pressing the die 1, the peripheral edge of the die 1 is formed. A deflection allowing portion 3 whose portion can be bent by pressurization of the clay is provided on the back surface of the front plate portion 2 a of the pressing jig 2. FIG. 1 shows an embodiment in which the bending allowance portion 3 provided on the back surface of the front plate portion 2a of the pressing jig 2 is a space portion formed by groove processing (counterbore processing). Note that the front plate portion 2a and the cylindrical body portion 2b are not integral and can be separated.
[0012]
When the clay press-fitted into the die holder 4 is extruded from the base 1 as a honeycomb structure while pressing the base 1, the base 3 is formed by the space 3 formed on the back surface of the front plate portion 2 a of the holding jig 2. The peripheral edge of 1 can be bent by pressing the clay.
[0013]
FIG. 5 shows the results of the bending state of each part of the base 1 due to the pressing of the clay when the honeycomb structure is extruded using the honeycomb structure forming base jig 5 of the present invention configured as described above. It is shown in 2.
[0014]
The zero point on the horizontal axis indicates the center of the base 1. The central portion and the peripheral portion of the base 1 are greatly bent, and the bending of the pressing portion 11 by the front plate portion 2a of the pressing jig 2 is small. As a result, the cross section at the base center line is bent into a W shape.
[0015]
In this case, the tensile stress generated on the outermost surface of the slit layer 13 of the base 1 is as shown in FIG. Also in this graph, the zero point on the horizontal axis indicates the center of the base 1. The maximum tensile stress is generated in the central portion of the base 1 and a considerable stress is generated in the peripheral portion.
[0016]
FIG. 3 shows that the tensile stress generated in the central portion of the base 1 is 8.3 kgf / mm when the diameter of the base 1 is 200 mm and the thickness of the space 3 that is grooved (counterbored) is 30 mm. ² was shown.
[0017]
On the other hand, as a comparative example, in the case where the honeycomb structure is extruded by using exactly the same die except that the front plate portion 2a of the holding jig 2 is not counterbored, each portion of the die is bent. The amount and generated stress are shown in FIGS.
The cross-sectional shape of the deflection in the base line of the base is a mountain shape having a symmetrical ridge line with the center at the top and the left and right. The generated stress is maximum at the center of the base 1 and is a high value of 12 kgf / mm ² as compared with the case where a space portion is formed by counterbore.
[0018]
That is, by providing the space 3 that allows bending at the peripheral edge of the base 1, the maximum tensile stress generated in the base 1 can be greatly reduced to about 30% compared to the conventional base jig. . Therefore, the thickness of the base 1 can be further reduced.
[0019]
The present inventors estimate the mechanism by which the maximum tensile stress generated in the base 1 is reduced by providing the space 3 that allows bending at the peripheral edge of the base 1 as follows. In other words, the center portion of the base 1 is bent in the opposite direction to the direction in which the clay is pushed out by using the high rigidity of the base 1 and the pressing portion 11 by the front plate portion 2a of the holding jig 2 for pressing the base 1 as a fulcrum. It is estimated that this is the result of offsetting the bending of the base due to the pressing of the clay.
[0020]
Although FIG. 1 shows an embodiment in which the space portion 3 formed by the groove processing on the back surface of the front plate portion 2a of the holding jig 2 corresponding to the peripheral edge portion of the die is shown, the die for honeycomb structure extrusion molding of the present invention is shown. Various other embodiments are possible for the tool 5. FIG. 4 shows an embodiment in which a space 8 by notches is provided on the surface of the periphery of the base 1 on the slit layer 13 side. The depth of the space 8 is usually 0.05 to 0.1 mm. However, depending on the earth pressure, the depth of the space 8 may be further increased. The length A of the pressing part 11 is sufficient if it is long enough to prevent the pressing part 11 from being crushed, and is preferably shorter. Usually, 2 to 3 mm is sufficient.
[0021]
FIG. 5 shows an embodiment in which a convex portion 9 is provided on the back surface of the front plate portion 2 a of the pressing jig 2, the base 1 is pressed by the convex portion 9, and the outer peripheral side of the convex portion 9 is the space portion 15. Further, the convex portion 9 is separated from the pressing jig 2, and for example, a tape having a thickness of 0.1 mm is attached to the back surface of the front plate portion 2 a of the pressing jig 2 or the surface of the base 1, and the tape surface is attached to the base 1. It is also possible to use the pressing portion 11.
[0022]
In the die jig 5 of the present invention, the stress generated in the die 1 can be reduced as the length B of the space portions 3, 8, and 15 is increased. Therefore, as shown in FIG. 6, it is more effective if the diameter of the die 1 is made larger than the inner diameter of the die holder 4 and the inner diameter of the holding jig 2 is made larger accordingly.
[0023]
【The invention's effect】
As described above, according to the die for extrusion molding of a honeycomb structure of the present invention, it is possible to further reduce the thickness of the die without destroying the die. The thinning of the die facilitates slitting of the die, shortens the processing time, and reduces the production cost of the die. It is also possible to reduce the pressure of the clay.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a die for extrusion molding of a honeycomb structure of the present invention.
FIG. 2 is a graph showing a relationship between a portion of a base that is bent by pressing of a clay and a bending amount. In the graph, Δ indicates an example of the present invention, and □ indicates a comparative example.
FIG. 3 is a graph showing the relationship between the base portion and the generated stress with respect to the generated stress generated in the base by pressing of the clay. In the graph, Δ indicates an example of the present invention, and □ indicates a comparative example.
Fig. 4 is a cross-sectional view of a main part showing another embodiment of a die jig for honeycomb structure extrusion molding according to the present invention.
Fig. 5 is a cross-sectional view of a principal part showing still another embodiment of a die jig for extrusion molding of a honeycomb structure of the present invention.
Fig. 6 is a cross-sectional view of a main part showing still another embodiment of a die jig for extrusion molding of a honeycomb structure of the present invention.
FIG. 7 is an enlarged cross-sectional view of a main part of the base.
FIG. 8 is a cross-sectional view showing a conventional honeycomb structure extrusion molding die jig.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... Holding jig, 2a ... Front plate part, 2b ... Cylindrical body part, 3 ... Space part which accept | permits bending of peripheral part of base, 4 ... Die holder, 5 ... Extrusion of honeycomb structure of the present invention Forming die jig, 6 ... slit formed in the die, 7 ... back hole formed in the back side of the die, 8 ... notch space portion formed in the periphery of the die, 9 ... front plate part of the holding jig Projections formed on the back surface, 10 ... opening formed in the front plate portion of the pressing jig, 11 ... pressing portion, 12 ... peripheral edge surface of the base, 13 ... slit layer of the base, 14 ... back hole layer of the base, 15 A space part formed on the outer peripheral side from the convex part, 20 ... a conventional base jig, 21 ... a conventional base pressing jig, 21a ... a plate-like part, 21b ... a cylindrical part.

Claims (7)

A plate-shaped die for extruding the honeycomb structure, an opening provided opposite to the die, a front plate portion for pressing the surface of the die, and a front plate portion formed integrally with the front plate portion Honeycomb structure extrusion molding comprising a pressing jig composed of a cylindrical body portion that comes into contact with the peripheral edge surface and the inner peripheral surface of the base, and a die holder that holds the pressing jig and receives the press-fit clay. In the base jig,
When the clay press-fitted into the die holder is extruded from the die as a honeycomb structure while pressing the die, the peripheral edge of the die is bent in the extrusion direction of the clay by the pressure of the clay. A die for jig extrusion molding of a honeycomb structure, characterized in that the bending allowable portion is a space provided between the front plate portion and the peripheral portion of the die. 2. The die jig for extrusion molding of a honeycomb structure according to claim 1, wherein the bending allowance portion is a space portion formed by groove processing on the back surface of the front plate portion of the pressing jig. 2. The die jig for extruding a honeycomb structure according to claim 1, wherein the bending allowance portion is a notch space portion formed on a peripheral surface of the die. The die jig for extruding a honeycomb structure according to claim 1, wherein a convex portion is provided on the back surface of the front plate portion of the pressing jig, and the surface of the die is pressed by the convex portion. The honeycomb structure extrusion molding die jig according to claim 4, wherein the convex portion provided on the back surface of the front plate portion of the pressing jig is separate from the pressing jig. 6. The die jig for extruding a honeycomb structure according to claim 5, wherein a separate convex portion provided on the back surface of the front plate portion of the pressing jig is an adhesive tape. The honeycomb structure extrusion molding die according to any one of claims 1 to 6, wherein a diameter of the die is larger than an inner diameter of the die holder.

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