JP2019025749A - LIM molding method - Google Patents

Abstract

To provide a LIM molding method which is less likely to cause fibrous foreign matter from paper and hardly causes problems of contamination.SOLUTION: In a LIM molding method, paper 31 placed in a mold 11 for molding a molded article so as to intersect with a material flow path 21 in the mold 11 is removed from the mold 11 after molding with a burr attached to the paper 31. An easily breakable part comprising a slit 33 or a small hole is provided in advance at a position intersecting with the material flow path 21 in the paper 31, and when a molding material is filled in the mold 11, an aperture area of the easily breakable part expands by filling pressure of the molding material flowing through the material flow path 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a LIM molding method according to a molding technique. The LIM molding method of the present invention is used for molding a fuel cell component, for example.

  In general, in LIM molding, after the molding, as a preparation for the next molding, a vent burr generated in the runner mold is cleaned and removed. However, depending on the shape and quantity of burrs, it takes time to clean and remove, causing cycle time (CT) to deteriorate.

  Therefore, conventionally, as shown in FIG. 5B, in order to eliminate the above inconvenience, the paper 31 is combined with the mold 11, and the paper 31 is placed in the mold 11 so as to intersect the material flow path 21 in the mold 11. A technique has been developed in which burrs (not shown) are attached to the paper 31 and the burrs attached to the paper 31 are removed simultaneously when the paper 31 is removed from the mold 11 after molding.

Japanese Utility Model Publication No. 3-52124 JP-A-5-4250 JP, 2006-87882, A

  However, the burr removing method using the paper 31 has room for improvement in the following points.

  That is, in the prior art, as shown in FIG. 5A, the paper 31 is not subjected to any special processing such as forming a slit. As shown in FIG. 6, the paper 31 installed so as to intersect the material flow path 21 in the mold 11 is pierced by the filling pressure of the molding material S flowing in the material flow path 21. Although the molding material S is allowed to pass, when the paper 31 is pierced, a part of the paper 31 is broken and fine fibrous foreign matter 32 is generated from the paper 31, and the fibrous foreign matter 32 is mixed into the molding material S. Sometimes. Therefore, in this case, it is necessary to carefully select the material of the paper 31 so as not to cause a so-called contamination problem.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a LIM molding method in which fibrous foreign matters are less likely to be generated from paper, and therefore, contamination problems are less likely to occur.

  In order to solve the above-mentioned problems, the LIM molding method of the present invention is such that a paper is placed in the mold so as to intersect a material flow path in a mold for molding a molded product, and the paper is molded from the mold after molding. A LIM molding method for simultaneously removing burrs adhering to the paper at the time of removing, wherein an easy-breaking portion consisting of a slit or a small hole is provided in advance at a position intersecting the material flow path in the paper, When the molding material is filled, an opening area of the easily breakable portion is enlarged by a filling pressure of the molding material flowing through the material flow path.

  As an embodiment, in the above-described LIM molding method, the slit is formed in a plane linear shape or a radial shape.

  In the present invention, since the easily breakable portion made of slits or small holes is provided in advance in the paper, the molding material passes through the paper while expanding the opening area of the easily breakable portion when the molding material passes through the paper. Therefore, unlike the above-described prior art, it does not occur that the molding material breaks through the paper and a part of the paper is broken, so that it is possible to suppress the generation of fibrous foreign matter from the paper. Therefore, it is possible to provide a LIM molding method in which fibrous foreign matter is less likely to be generated from the paper, and therefore, the problem of contamination is less likely to occur.

FIG. 1 (A) is a plan view of a paper used for carrying out the LIM molding method according to the embodiment, and FIG. 1 (B) is a cross-sectional view of the paper installed in a mold. Sectional drawing which shows the state which filled the molding material in the metal mold | die FIG. 3A is a plan view of the main part showing another example of the paper, and FIG. 3B is a cross-sectional view of the main part of the paper and the mold. Plan view showing another example of paper FIG. 5 (A) is a plan view of a paper used for carrying out the LIM molding method according to the background art, and FIG. 5 (B) is a sectional view showing a state where the paper is installed in a mold. Sectional drawing which shows the state which filled the molding material in the metal mold | die

  In the LIM molding method according to the embodiment, as shown in FIG. 1 (B), a paper 31 is installed in the mold 11 so as to intersect the material flow path 21 in the mold 11 for molding a molded product, A procedure for simultaneously removing burrs (not shown) adhering to the paper 31 when the paper 31 is removed from the mold 11 after molding, as shown in FIG. A slit 33 as an easily breakable portion is provided in advance at a position intersecting with the flow path 21, and as shown in FIG. 2, the filling pressure of the molding material S flowing through the material flow path 21 when the mold 11 is filled with the molding material S To enlarge the opening area of the slit 33.

  The mold 11 is formed by molding a molded product such as a fuel cell component by the LIM molding method. The mold 11 has a plurality of divided molds composed of an upper mold 12, a runner mold 13, and a lower mold 14 that are combined so as to be openable and closable. A material flow path 21 in which the runner part 24, the gate part 25, and the cavity part 26 are made continuous is provided.

  The paper 31 is installed by being sandwiched between the upper mold 12 and the runner mold 13 while keeping the paper 31 flat. Since the installed paper 31 intersects the runner portion 24 in the material flow path 21, a slit 33 is provided in advance at a position where the paper 31 intersects the runner portion 24. A plurality of runner portions 24 may be provided. In the present embodiment, two (two) runner portions 24 are provided, and accordingly, slits 33 are also provided at two locations.

  The slit 33 may be a planar straight slit, or may be a radial slit. In FIG. 1A, the slit 33 is formed in a planar cross shape as an example of the radial slit. The slit 33 is formed as a cut that penetrates the paper 31 in the thickness direction. Therefore, the flow resistance is set to be small locally, so that the molding material S easily flows through the slit 33.

  In the LIM molding method having the above configuration, since the slits 33 are provided in the paper 31 in advance, the molding material S does not pierce the paper 31 when the molding material S passes through the paper 31, but the opening area of the slit 33 is increased. While passing through the paper 31. Therefore, as seen in the above-mentioned prior art, since the situation that the molding material S breaks through the paper 31 and a part of the paper 31 is broken does not occur, the generation of fine fibrous foreign matter from the paper 31 is suppressed. Is possible. Therefore, since it becomes difficult to generate a fibrous foreign material from the paper 31, the problem of contamination is less likely to occur.

  The arrangement, number, planar shape, and the like of the slits 33 provided in advance in the paper 31 are appropriately changed according to the configuration of the mold 11.

  For example, in the example of FIG. 3, since the paper 31 is arranged to overlap the runner groove portion 24 b in addition to the runner hole portion 24 a in the runner portion 24, the runner groove portion is located immediately below the sprue portion (not shown). A planar straight slit 33 having a predetermined length L is provided at a position immediately above 24b. If the slit 33 is too long, the releasability deteriorates, and if it is too short, the functionality deteriorates. Therefore, the slit 33 is preferably provided over about half of the runner portion 24. Moreover, it is preferable to provide to the middle of a sprue part (injection part) and a runner part.

  Further, in the example of FIG. 4, slits 33 are provided in four places on the plane of one sheet of paper 31, and two of them are two planar straight slits 33 having a predetermined length. It is supposed to be combined with a book and an angle.

  Instead of this, the slit 33 may be a single or a plurality of small holes.

11 Mold 12 Upper mold 13 Runner mold 14 Lower mold 21 Material flow path 22 Nozzle touch part 23 Sprue part 24 Runner part 24a Runner hole part 24b Runner groove part 25 Gate part 26 Cavity part 31 Paper 32 Fibrous foreign matter 33 Slit S Molding material

Claims (2)

A LIM that installs a paper in the mold so as to intersect a material flow path in a mold for molding a molded product, and simultaneously removes burrs attached to the paper when the paper is removed from the mold after molding. A molding method,
Providing an easily breakable portion consisting of a slit or a small hole in advance at a position intersecting the material flow path in the paper,
An LIM molding method characterized by enlarging an opening area of the easily breakable portion by a filling pressure of the molding material flowing through the material flow path when the molding material is filled into the mold. The LIM molding method according to claim 1,
The LIM molding method, wherein the slits are formed in a plane linear shape or a radial shape.

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