JP4606097B2 - Mold for molding - Google Patents

Description

  The present invention relates to a molding die used for pulp mold molding and the like.

Molds having a cavity molding surface include a single metal block, an assembly of a plurality of metal blocks, and a cavity molding surface on the upper surface of a plurality of laminated metal sheets. What provided the one steel plate shape | molded in the shape of this is known.
By the way, in the manufacture of a pulp mold molded body, the papermaking process is usually at room temperature, but in the heat drying process, the mold is heated from room temperature to about 150 ° C to 230 ° C. As a result of repeated expansion and contraction of the mold while receiving, a dimensional change occurs in the cavity molding surface, and it may be difficult to manufacture a pulp mold molded body with high molding accuracy. In addition, as a passage for releasing steam generated during drying, it is necessary to provide a large number of pores in the mold or to form slits by wire electric discharge machining.

  The following Patent Document 1 discloses a molding die for improving the cooling efficiency of a die and reducing the generation of thermal stress in a metal pressure casting die. In the molding die described in Patent Document 1, the support member assembly, which is a component of the die, is provided with a cooling medium passage that circulates inside thereof, and cold water is circulated in the cooling medium passage to thereby provide a die. Is cooling.

JP-A-7-32121

  However, the molding die described in Patent Document 1 does not disclose a technical means for absorbing expansion / contraction of the mold component itself due to heat. Therefore, in the molding die described in Patent Document 1, the dimensional change of the cavity molding surface due to expansion / contraction of the constituent members of the die is large, and it is difficult to manufacture the molded body with high accuracy.

  Therefore, the object of the present invention is to absorb expansion / contraction due to heat, hardly cause dimensional change of the cavity molding surface, have a large number of air passages (voids), and can mold the molded body with high accuracy. The object is to provide a molding die.

  In the present invention, a large number of metal plates having a large number of convex portions between the frames are laminated and fixed in a state where gaps are formed by the convex portions between the metal plates, respectively. This object is achieved by providing a molding die in which a cavity molding surface is formed by the upper end surface of the metal plate.

  According to the molding die of the present invention, the expansion and contraction due to heat is absorbed, the dimensional change of the cavity molding surface hardly occurs, and there are many air passages (voids), and the molded body is molded with high accuracy. be able to.

  Hereinafter, a preferred embodiment in which the molding die of the present invention is used as a drying mold for pulp molding will be described with reference to FIGS. In FIGS. 1 and 2, the protrusions of the metal plate are not shown, and the thickness of the metal plate and the space between the metal plates are shown for convenience.

As shown in FIGS. 1 to 3, the molding die 1 according to this embodiment includes a large number of metal plates 4 having a large number of convex portions 41 between the frame bodies 2, 2. Each of the protrusions 41 is laminated and fixed in a state where a gap P is formed, and a plurality of the laminated and fixed metal plates 4 (“multiple and fixed metal plates 4” are hereinafter referred to as “laminated metal plates 5”). )) Is the cavity molding surface. The voids P thus formed can absorb the expansion / contraction of the mold due to heat.
In the molding die of the present invention, the metal plate stacking direction is the left-right direction, and the cavity opening direction is the upward direction.

The molding die 1 according to the present embodiment will be described in detail. The molding die 1 according to the present embodiment has a concave portion in a front view composed of the frame bodies 2 and 2 and the bottom plate 3 as shown in FIGS. It consists of a bottomed frame body having a shape and a large number of metal plates 4 laminated and fixed between the frame bodies 2 and 2.
As shown in FIGS. 1 and 2, the frame bodies 2 and 2 are rectangular plates and are formed of a pair of plates that are spaced apart in the left-right direction of the molding die 1.
Four fixing bolts B1 are embedded in a screwed state on the outer surface side of the plate, and four pressing members B2 respectively connected to the front ends of the fixing bolts B1 are provided on the inner surface side thereof. A portion is embedded from the inner surface of the plate. In the vicinity of the front and rear ends of the lower surface of the plate, a female screw portion capable of screwing a connecting bolt B3 (described later) is formed.

  The bottom plate 3 that constitutes the bottomed frame is a rectangular plate that is in contact with the lower surfaces of the pair of plates, and has connecting bolt holes through which four connecting bolts B3 can be inserted. The plate and the bottom plate 3 are connected by inserting a connecting bolt B3 through the connecting bolt hole and screwing into the female screw portion, thereby forming the bottomed frame.

As the material of the plate and the bottom plate 3, a metal material having a low linear expansion coefficient is preferably used, and examples thereof include an aluminum alloy material and a steel material.
As a material of the fixing bolt B1 and the connecting bolt B3, a steel material having a low linear expansion coefficient is used.

As shown in FIGS. 1 and 2, a large number of metal plates 4 having a large number of convex portions 41 (see FIG. 3) are provided between the frame bodies 2, 2. Thus, the laminated metal plate 5 is formed by being laminated and fixed in a state where the gap P is formed. The left and right side surfaces of the laminated metal plate 4 are pressed by the pressing members B2 of the pair of plates constituting the frames 2 and 2, and as a result, the laminated metal plate 5 is fixed between the frames 2 and 2. The
The bottom plate 3 is provided on the lower end surface 52 of the laminated metal plate 5, and the lower end surface 52 of the laminated metal plate 5 is supported by the bottom plate 3.

The thickness of the metal plate 4 (the thickness of the portion where the convex portions 41 are not formed) T1 [see FIG. 3C] is preferably 0.1 mm to 3.0 mm, more preferably 0.5 mm to 2. 0 mm. The area of the metal plate 4 and the thickness of the laminated metal plate 5 (length in the lamination direction) are appropriately set according to the size of the cavity 6 and the like.
Various metal plates can be used, and examples include an aluminum alloy plate and a stainless alloy plate. In the present embodiment, an aluminum alloy plate is used from the viewpoint of weight reduction and the like.

As shown in FIG. 3A, a large number of convex portions 41 are formed on the metal plate 4 and project only on one side of the metal plate 4. Further, as shown in FIGS. 3B and 3C, the top of the convex portion 41 is in contact with the flat portion of the metal plate 4 (the portion where the convex portion 41 is not formed), so that between the metal plates 4. A gap P is formed in the gap.
The convex portion 41 is formed by embossing because it is easy to process and low cost in the present embodiment. 3 (a) to 3 (c) show the metal plate 4 in detail in FIG. 1 (a).

In the present embodiment, the convex portions 41 are irregularly arranged in the surface direction of the metal plate 4 over the entire surface of the metal plate 4. The reason is that when the convex portions 41 formed by embossing are regularly arranged, when the metal plates 4 are stacked, the convex portion 41 of one metal plate 4 is the convex portion 41 of the other metal plate 4. This is because there is a possibility that the gap P is not formed between the metal plates 4 by fitting into the recesses on the back side of the metal plate 4. In FIGS. 3B and 3C, the convex portions 41 are regularly arranged for convenience.
In the present embodiment, the convex portion 41 has a truncated cone shape because embossing is easy.
The ratio of the total area S2 of the area of the convex portion 41 (projected area when viewed in the direction penetrating in its height direction) to the area of the metal plate 4 (projected area when viewed in the thickness direction) S1. (S2 / S1) is preferably 20% to 60%.

The height of the convex portion 41 is made constant from the viewpoint of making the gap P between the two metal plates 4 constant.
In the present embodiment, the height of the convex portion 41 is the same as the interval T2 of the gap P. The interval T2 of the gap P is appropriately selected according to the characteristics of the molding material introduced into the cavity, the use of the mold, and the like. In general, if the gap T2 between the gaps P is too wide, the molding material tends to flow into the gap P, and the surface shape of the molded body tends to be poor. On the other hand, if the gap T2 between the gaps P is too narrow, the cooling effect of the mold. Therefore, the size of the gap P is set in consideration of these.
The gap interval T2 is preferably 0.2 mm to 1.0 mm, more preferably 0.2 mm to 0.5 mm, and most preferably 0.25 mm to 0.3 mm.

The cavity 6 is formed in the upper end surface 51 of the laminated metal plate 5 (see FIG. 1). The shape of the cavity 6 is formed by carving the upper end portion of the laminated metal plate 5 in accordance with the shape of the molded body. The shape of the cavity 6 in this embodiment is such that one small hemisphere is connected to the right side of one large hemisphere, and two smaller hemispheres are connected to the left side of the large hemisphere.
The formation of the cavity 6 in this embodiment is based on a method in which a large number of metal plates 4 are laminated and fixed between the frames 2 and 2 to form a laminated metal plate 5 and the upper end portion of the laminated metal plate 5 is engraved.

A method for using the molding die 1 of the present embodiment when used as a drying mold in pulp mold molding will be described.
First, an undried pulp mold molded body (hereinafter, also referred to as “undried molded body”) having a shape substantially coinciding with the cavity 6 is obtained by a papermaking process and a dewatering process. Next, an undried molded body (not shown) is placed in the cavity 6. Before or after the mounting, the entire molding die 1 including the laminated metal plate 5 is heated. By this heating, the undried molded body is dried, and a dried pulp mold molded body is obtained.

Here, in the molding die 1 of the present embodiment, the void P is formed by the convex portion 41 between the adjacent metal plates 4 and 4, and the thermal deformation (expansion and contraction) occurring in the metal plate 4 is caused by the convex portion 41. Is absorbed as a cushioning material, so that a dimensional change hardly occurs on the molding surface of the cavity 6. As a result, a pulp mold molded body with high shape accuracy can be manufactured.
The gap P also serves as a water vapor passage. That is, since water vapor generated during drying is discharged from the gap P, it is not necessary to separately provide a water vapor ventilation path in the drying mold for pulp molding.

Next, another embodiment of forming the convex portion of the metal plate will be described with reference to FIG. As shown in FIG. 4, the metal plate 4 ′ in another embodiment is provided so that the convex portions 41 protrude from both surfaces.
In the metal plate 4 ′ having such a shape that the convex portions 41 protrude on both surfaces, by appropriately setting the arrangement, size, shape, etc. of the convex portions 41, if these metal plates 4 ′ are laminated, Between the adjacent metal plates 4 ′ and 4 ′, the tops of the convex portions 41 of the respective metal plates 4 ′ can be overlapped with each other. In this case, the width of the gap is twice the height of the convex portion 41.

  In addition, as shown in FIG. 5, the metal plate in yet another embodiment includes a metal plate 4 ′ having a shape in which convex portions 41 protrude on both sides, and a metal plate in which the convex portions 41 protrude only on one side and the other side is flat. 4 is laminated next to each other. As shown in FIG. 5, when the convex portion 41 is brought into contact with a flat surface, the width of the gap becomes the same as the height of one convex portion 41. Moreover, when it laminates | stacks so that the surface in which the convex part 41 was formed may contact | abut (not shown), by setting the arrangement | positioning of the convex part 41, the width | variety of a space | gap is made twice the height of the convex part 41. It can also be.

The molding die of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.
As long as the frame can stack and fix a large number of metal plates having a large number of projections between the metal plates in a state where gaps are formed between the metal plates, the frame in the above embodiment is used. It is not limited to body composition.
The convex portion of the metal plate can be formed by a processing method other than embossing. The convex portions can be regularly or irregularly arranged in the surface direction of the metal plate. The shape of the convex portion can be various shapes such as a hemispherical shape and a truncated pyramid shape in addition to the truncated cone shape.
The shape of the cavity can be various shapes according to the shape of the molded body. As another method of forming the cavity, each metal plate is cut into a predetermined shape corresponding to the shape of the cavity before the metal plate is laminated and fixed, and when the metal plate is laminated and fixed, the cavity having the predetermined shape is formed. The method by which is formed.

In the above embodiment, the mold of the present invention is used as a drying mold for pulp mold molding. However, the mold for molding of the present invention may be used as a paper mold for pulp molding, a pressure dehydrating mold, or the like. it can. In addition to pulp mold molding, the molding mold of the present invention can also be used as injection molding molds for synthetic resins, metal mold molds, and the like.
In the molding die of the present invention, a pair of frame bodies can be arranged vertically and used, and the upper end side (opening side of the cavity) and the lower end side of a large number of laminated metal plates are arranged. It can also be used in the horizontal direction.

1A and 1B are diagrams showing an embodiment of a molding die according to the present invention, in which FIG. 1A is a plan view, and FIG. 1B is a cross-sectional end view taken along the line A-B-C-D-F shown in FIG. FIG. 2 is a cross-sectional perspective view taken along line II-II shown in FIG. 3 is a cross-sectional view showing a metal plate in the molding die shown in FIG. 1, (a) is a diagram showing one metal plate, (b) is a diagram showing two stacked metal plates, (C) is the elements on larger scale of (b). FIG. 4 is a side view showing a metal plate in another embodiment. FIG. 5 is a side view showing a metal plate in still another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molding die 2 Frame 3 Bottom plate 4, 4 'Metal plate 41 Convex part 5 Laminated metal plate 51 Upper end surface 52 Lower end surface 6 Cavity P Cavity

Claims (4)

A large number of metal plates having a large number of projections between the frame bodies are laminated and fixed in a state where gaps are formed by the projections between the metal plates, and a plurality of the metal plates that are laminated and fixed. a mold for molding cavity molding surface is formed by the upper end surface of
A number of the convex portions have a truncated cone shape, have a constant height, protrude only on one surface of the metal plate, and are irregularly arranged in the surface direction of the metal plate.   2. The molding die according to claim 1, wherein an interval between the plurality of metal plates laminated and fixed is the same as a height of the convex portion and is 0.2 mm to 1.0 mm.   3. The molding die according to claim 1, wherein a bottom plate is provided on a lower end side of the plurality of metal plates that are laminated and fixed, and a lower end side of the metal plate is supported by the bottom plate. The molding die according to any one of claims 1 to 3 , which is used in a drying mold for pulp mold molding.

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