JP2002264119A - Mold and molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold and a molding method which enable molding of a molded body of an almost prescribed thickness even when a material charge is excessive and enable also molding of the molded body having a clear-cut indentation pattern (design). SOLUTION: The mold 10 has a top force 11, a bottom force 12 and a side tool 13. A cavity surface of the top force 11 is provided with an indented surface 14, which is provided with an indentation pattern part 15 for forming an indentation pattern on the surface of the molded body. The bottom force 12 is provided with a protuberant surface 16 opposite to the indented surface 14. A rubber body 18 is inserted into an indented part 17 of the protuberant surface 16. When a charge of a material R is excessive on the occasion of press molding, the material R presses strongly the rubber body 18 in pressing and the rubber body 18 is compressed. At least a part of the excess of the material R is thereby made to get into the indented part 17 and the thickness of the individual molded bodies becomes uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die and a molding method for press-molding a plastic raw material such as a clay or cement kneaded material to form a molded body. The present invention relates to a mold having a mechanism capable of coping with the problem and a molding method using the mold.

[0002]

2. Description of the Related Art It is well known to press a raw material in a cavity between a pair of dies to form a formed body.

In this molding method, if the raw material supply amount (charge amount) into the mold is larger or smaller than the predetermined amount, the thickness of the formed body becomes larger or smaller accordingly than the predetermined thickness. Or Japanese Patent Application Laid-Open No. Hei 8-281621 discloses a pin or rod-shaped sliding portion provided on a cavity surface of a mold so as to be freely retractable. When the raw material charge amount is larger than a predetermined amount, the sliding portion is retracted from the cavity surface, and when the raw material charge amount is smaller than the predetermined amount, the sliding portion is protruded from the cavity surface. Has been described.

FIGS. 4 (a) and 4 (b) are cross-sectional views of the mold disclosed in the same publication when the mold is opened and when the mold is closed. This molding die includes an upper die 1 and a lower die 2, and a cavity is provided between the two.

[0005] A hollow portion 3 is provided in the upper die 1.
A through hole 5 penetrating from the hollow portion 3 to a substantially central portion of the ridge 4 of the upper die 1 is provided. The inside of the through hole 5 is slid so that the front end portion slides freely from the cavity surface. A moving part 6 is provided.

[0006] The base ends of the sliding parts 6 and 6 are connected to a pressing plate 7 in the hollow part 3 of the upper die 1. A cylinder 8 is provided in the hollow portion 3 to slide the sliding portions 6 and 6 at the same pressure per unit area as the forming press pressure by moving the pressing plate 7 forward and backward. The cylinder 8 is operated by a relief valve (not shown) provided outside the mold.

In order to perform press molding using this molding die, first, a plastic raw material is charged into the molding die to be in a mold-clamped state, and press molding is performed. At this time, if the charge amount of the raw material 9 is appropriate, the sliding portions 6 and 6 stop at positions where the tip surfaces thereof are flush with the cavity surface as shown in FIG. 4 (b).

If the amount of charge of the raw material 9 is too small, the sliding portions 6 and 6 slide to the position where the tip ends thereof have advanced into the cavity and stop. Is responsible for the small volume integral. Thereby, the molding pressure applied to the raw material 9 in the cavity becomes appropriate, and a hydraulically-inorganic molded body having a uniform thickness can be press-formed without causing molding failure.

When the charge amount of the raw material 9 is too large,
The sliding parts 6 and 6 stop by sliding to the position where the tip ends retreat from the cavity surface into the through holes 5 and 5,
Compensates for the volume of the charged raw material in the cavity.
Thereby, the molding pressure applied to the raw material 9 in the cavity becomes appropriate, and a hydraulic inorganic molded body having a uniform thickness can be press-formed without causing molding failure.

[0010]

The above-mentioned JP-A-8-281
In the molding die and the molding method of JP-A-62-62, if it is not known how much the amount of raw material charged into the molding die is larger or smaller than a predetermined amount, positioning (projection, retreat) of the sliding portion 6 is performed. Can not do.

[0011] The present invention provides a molding die capable of absorbing a variation in thickness of a molded body without any artificial operation even when the raw material charge amount is excessive, and a molding method using the molding die. The purpose is to provide.

It is another object of the present invention to provide a molding die and a molding method capable of molding a molded article having the uneven pattern clearly transferred when the molded article having the irregular pattern is molded. And

[0013]

A molding die according to the present invention (claim 1) has a first die and a second die, and the first die, the second die, A molding die for press-molding a molding raw material in a cavity between the cavities, wherein a concave portion is provided on a cavity surface facing at least one of the mold cavities, and an elastic body is provided in the concave portion. It is.

The molding method of the present invention (claim 5)
Using such a mold of the present invention, a molded article is press-molded from a plastic raw material.

According to the molding die and the molding method of the present invention, when the raw material is charged into the molding die and press-formed, if the charged amount of the raw material is more than a predetermined amount, the raw material presses the elastic body during pressing. And a part of the raw material enters the recess. As a result, the excess amount of the raw material is absorbed, and it becomes possible to form a molded body having a substantially predetermined thickness.

According to the present invention, the elastic member provided in the concave portion of the mold naturally retreats from the cavity surface by the molding pressure, and the amount of the raw material charged is detected, and an artificial operation is performed accordingly. Instead, the molding operation is simple.

In the present invention, it is preferable that a concave surface is provided on a cavity surface of the first mold, and the concave portion is arranged on a portion of the cavity surface of the second mold facing the concave surface.

In particular, it is preferable that a convex surface is provided on the cavity surface of the second mold so as to face the concave surface, and the concave portion is arranged on the convex surface. Also, in this case, even if the concave surface of the first mold is provided with a concave / convex pattern portion for forming a concave / convex pattern on the molded body, the raw material is sufficiently pressed into the concave / convex pattern portion to form the concave / convex pattern clearly. Can be transcribed.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a molding die and a molding method according to an embodiment. FIG. 1A shows a state before press molding, and FIG. 1B shows a state during press molding.

The molding die 10 has an upper die 11, a lower die 12, and a side die 13. The cavity surface of the upper die 12 is provided with a concave surface 14, and the concave surface 14 is provided with an uneven pattern portion 15 for forming an uneven pattern on the surface of the molded body.

The lower mold 12 has a convex surface 16 facing the concave surface 14. A concave portion 17 is provided at the uppermost portion of the convex surface 16, and a rubber body 18 is inserted into the concave portion 17. The rubber body 18 is preferably flush with the surface of the convex surface 16, but may protrude slightly or may recede.

In order to perform press molding using the molding die 10, the upper die 11 is removed from the side die 13, the raw material R is supplied onto the lower die 12, and the upper die 11 is fitted to the side die 13. And
The inside of the cavity is sucked and evacuated as needed.

Next, the upper die 11 is lowered, and the raw material R is pressed to obtain a molded body F. If the amount of charge of the raw material R is excessive during the press molding, the raw material R strongly presses the rubber body 18 during pressing, and the rubber body 18 is compressed as shown in FIG. 1 (b). Thereby, at least a part of the excess amount of the raw material R enters into the concave portion 17, and the thickness of the molded body becomes uniform.

In the above description, press molding is performed by lowering the upper mold 11, but press molding may be performed by raising the lower mold 12.

In the embodiment shown in FIG. 1, the lower mold 12 has a convex surface 16 corresponding to the concave surface 14 of the upper mold 11, but as shown in FIG. '
It may be. 2 are the same as those in FIG. 1, and the same reference numerals indicate the same parts.

However, in the present invention, as shown in FIG. 1, it is preferable to provide a convex surface 16 on the lower die 12 corresponding to the concave surface 14 of the upper die 11. When the convex surface 16 is provided in this manner, the amount of lateral movement of the raw material R during the press forming is reduced, and the raw material R is reliably filled to every corner in the uneven pattern portion 15. That is, as shown in FIG. 2, when the convex surface 16 is not provided and only the concave surface 14 is provided, when pressed, the raw material R in the cavity moves from the peripheral portion to the center side as shown by an arrow N to fill the concave surface 14. Try to move sideways. However, before the raw material R is sufficiently moved laterally, the raw material R is strongly pressed between the peripheral portion 11a of the upper die 11 and the lower die 12 ′ and becomes hard, and the raw material R becomes concave even when pressed no matter how much. Will not enter enough. As a result, as shown in FIG. 2 (b), voids V are formed in the uneven pattern portion 15, and the uneven pattern of the obtained molded body is
Tends to be unclear, which is not transferred clearly.

On the other hand, if the convex surface 16 is provided on the lower die 12 as shown in FIG. 1, it is almost unnecessary for the raw material R to move laterally toward the concave surface 14 during the press molding. Before the raw material R is hard pressed between the peripheral edge of the lower mold 11 and the peripheral edge of the lower mold 12, the raw material R is sufficiently filled in the uneven pattern portion 15. As a result, the obtained molded body has an uneven pattern in which the uneven pattern of the upper mold 11 is clearly transferred.

In the present invention, the distance between the concave surface 14 and the convex surface 16 is preferably larger than the distance between the peripheral portions of the upper mold 11 and the lower mold 12 on average.

In the present invention, an elastic body other than the rubber body 18 may be used. FIGS. 3 (a) and 3 (b) show an example thereof. In FIG. 3 (a), a coil spring 20 as an elastic body is disposed in the recess 17 and the spring 20 is provided at the entrance of the recess 17. Plate 21 backed up by
Has been arranged.

In FIG. 3 (b), a plate is disposed near the middle of the recess 17 and a rubber body 22 supported by the plate 21 is disposed near the entrance of the recess 17.

Although not shown, a spring device other than rubber or a coil spring (for example, an air spring) may be used. In addition, the shape of the rubber body is arbitrary, such as a cylindrical shape, an elliptical cylindrical shape, and a prismatic shape.

In the present invention, it is preferable to select the size and number of the elastic bodies according to the size and shape of the concave surface 14 and the convex surface 16. It is preferable that the elastic body has a deformation characteristic that does not deform so much under normal molding pressure and sufficiently deforms when the molding pressure is higher than the normal pressure.

[0033]

As described above, according to the present invention, it is possible to form a molded body having a substantially specified thickness even if the raw material charge is excessive. Moreover, in this molding, an artificial molding thickness adjusting operation is not required, and the molding is easy.

Further, according to the present invention, it is possible to mold a molded article having a clear uneven pattern (design).

[Brief description of the drawings]

FIG. 1 is a sectional view showing a molding die and a molding method according to an embodiment.

FIG. 2 is a cross-sectional view illustrating a molding die and a molding method according to another embodiment.

FIG. 3 is a cross-sectional view showing another configuration example of the elastic body.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Mold 11 Upper mold 12 Lower mold 13 Side mold 14 Concave surface 15 Concavo-convex pattern 16 Convex surface 17 Concave part 18 Rubber body 20 Coil spring 21 Plate 22 Rubber body

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Attack Sekiguchi 5-1-1 Koie Honcho, Tokoname-shi, Aichi Prefecture Inax Corporation (72) Inventor Masaki Miwa 5-1-1 Koie Honcho, Tokoname-shi, Aichi Co., Ltd. Inside Inax (72) Inventor Akinori Miyazono 27-1 Higashi-Shinkiri, Nezaki-cho, Anjo-shi, Aichi Prefecture Inside Miyazono Seisakusho Co., Ltd. (72) Inventor Haruo Matsunaga 27-1 Higashi-Shinkiri, Nezaki-cho, Anjo-shi Aichi Pref. (Reference) 4G053 AA19 BB15 BF01 CA03 CA16 CA23 EA03 EA33 EA34 EB11 4G054 AA01 AA05 AB03 AC04 AC06 BA02 BA45 BA47

Claims (5)

[Claims] 1. A mold having a first mold and a second mold, wherein a molding material is press-molded in a cavity between the first mold and the second mold. A molding die, wherein a concave portion is provided on a cavity surface facing a cavity of at least one mold, and an elastic body is provided in the concave portion. 2. The method according to claim 1, wherein a concave surface is provided on a cavity surface of the first mold, and the concave portion is arranged on a portion of the cavity surface of the second mold facing the concave surface. Characteristic mold. 3. The mold according to claim 2, wherein a convex surface is provided on the cavity surface of the second mold so as to face the concave surface, and the concave portion is arranged on the convex surface. 4. The mold according to claim 2, wherein the concave surface of the first mold is provided with a concave / convex pattern portion for forming a concave / convex pattern on the molded body. 5. A molding method, wherein a molding is press-molded from a plastic raw material using the molding die according to claim 1.