JP3478277B2 - Molding method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention press-molds plastic raw materials such as clay and cement kneaded materials to form molded articles.
That relates to a molding method, molding side using a mold having a mechanism that can specifically deal with variations in the charge amount of the raw material
It relates to the law.

[0002]

2. Description of the Related Art A method of forming a molded body by pressing a raw material in a cavity between a pair of molds is well known.

In this molding method, if the amount of raw material supplied (charge amount) into the mold is larger than the planned amount, or conversely, it is smaller, the thickness of the molded product becomes thicker or thinner than the planned thickness. Or In order to eliminate such a variation in the thickness of the molded body due to the variation in the charge amount, Japanese Patent Laid-Open No. 8-281621 discloses that a pin or rod-shaped sliding portion is provided on the cavity surface of a mold so that the sliding portion can be retracted. A molding die is configured such that the sliding portion is retracted from the cavity surface when the raw material charge amount is larger than the planned amount, and conversely, the sliding portion is projected from the cavity surface when the raw material charge amount is smaller than the planned amount. Have been described.

FIGS. 4 (a) and 4 (b) are cross-sectional views of the forming die of the same publication at the time of opening and closing the mold. This mold comprises an upper mold 1 and a lower mold 2, and a cavity is provided between them.

A hollow portion 3 is provided in the upper mold 1.
A through hole 5 penetrating from the hollow portion 3 to a substantially central portion of the protrusion 4 of the upper mold 1 is provided, and the tip portion of the cavity surface is slidably slidable by sliding in the through hole 5. A moving part 6 is provided.

The base ends of the sliding parts 6 and 6 are connected to the pressing plate 7 in the hollow part 3 of the upper mold 1. Inside the hollow portion 3, there is provided a cylinder 8 that slides the sliding portions 6 and 6 at the same sliding pressure per unit area as the molding press pressure by advancing and retracting the pressing plate 7. 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 bring the mold into a clamped state and press molding is performed. At this time, when the charge amount of the raw material 9 is proper, the sliding portions 6 and 6 are stopped at a position where their tip surfaces are flush with the cavity surface, as shown in FIG.

When the charge amount of the raw material 9 is too small, the sliding portions 6 and 6 are slid to the positions where the tips of the slide portions 6 and 6 have advanced into the cavity and stopped, and the charge amount of the raw material in the cavity is reduced. Responsible for the less volume. As a result, the molding pressure applied to the raw material 9 in the cavity becomes appropriate, and it is possible to press-mold a hydraulic inorganic molding having a uniform thickness without causing molding defects.

When the charge amount of the raw material 9 is too large,
The sliding parts 6 and 6 are slid to the positions where the tips of the sliding parts 6 and 6 are retracted from the cavity surface into the through holes 5 and 5, and then stopped,
Compensate for the large volume of raw material charge in the cavity.
As a result, the molding pressure applied to the raw material 9 in the cavity becomes appropriate, and it is possible to press-mold a hydraulic inorganic molding having a uniform thickness without causing molding defects.

[0010]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the molding die and the molding method of Japanese Patent Laid-Open No. 62, if it is not known how much or less the amount of raw material charge to the molding die is than the predetermined amount, the sliding portion 6 is positioned (projected or retracted). I can't.

[0011] The present invention, when the raw material charge amount is excessive even without making any manual operation, to provide a molding method using a forming shape type that can be absorbed thickness variation of a molded article The purpose is to

Further, the present invention, when molding a molded article having an uneven pattern, and an object thereof is to provide a forming form method capable of molding a molded article this uneven pattern is crisp and transferred .

[0013]

According to the molding method of the present invention (claim 1), a molding die is used to prepare a molded body from a plastic raw material.
In the molding method for scan molding forming die has a first die and a second die, the concave is provided on the key Yabiti surface of the first mold, a second mold cavity If the surface is provided with a convex surface facing the concave surface, the convex surface is provided with a concave portion, and the elastic body is installed in the concave portion, and if the charge amount of the raw material is excessive than the planned amount, press It is characterized in that a part of the raw material enters the concave portion due to the elastic body retreating due to the molding pressure during molding .

[0014] According to forming shapes the method of the present invention, when the press-molded by charging raw materials into the mold, when the charge amount of the raw material is in excess than a predetermined amount, retracted by pressing raw material an elastic body at the time of press Then, a part of the raw material enters the recess.
Thereby, the excess amount of the raw material is absorbed, and it becomes possible to mold a molded body having a substantially predetermined thickness.

In the present invention, the elastic body provided in the concave portion of the mold is naturally retracted from the cavity surface by the molding pressure, and the amount of raw material charge is detected and an artificial operation is applied accordingly. However, the molding operation is simple .

In the present invention, convex surface disposed to face the concave surface on the cavity surface of the second mold, but the recess convex surfaces are arranged, in this case, the concave surface of the first mold Even if the molded product is provided with an uneven pattern portion for forming an uneven pattern, the raw material can be sufficiently pushed into the uneven pattern portion to transfer the uneven pattern in a clear manner.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Embodiments will be described below with reference to the drawings. Figure 1 is a sectional view showing the engagement Ru formed form method to the embodiment, (a) diagram shows the state before press-forming, (b) diagram shows the state during pressing.

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

The lower mold 12 is provided with 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. It is preferable that the rubber body 18 is flush with the surface of the convex surface 16, but the rubber body 18 may slightly project or may retreat.

To perform press molding using this 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 then the upper die 11 is fitted into the side die 13. Let
If necessary, suction and exhaust the inside of the cavity.

Next, the upper die 11 is lowered and the raw material R is pressed to form a compact F. If the amount of charge of the raw material R is excessive during this 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). As a result, at least a part of the excess amount of the raw material R enters the recess 17, and the thickness of the molded body becomes uniform.

In the above description, the upper mold 11 is lowered and press-molded, but the lower mold 12 may be lifted and press-molded .

In the present invention, as shown in FIG. 1, the lower mold 12 is provided with the convex surface 16 corresponding to the concave surface 14 of the upper mold 11. By providing the convex surface 16 in this manner, the amount of lateral movement of the raw material R during the press molding is reduced, and the raw material R is surely filled in every corner of the uneven pattern portion 15. That is, when the convex surface 16 is not provided as shown in FIG. 2 and only the concave surface 14 is provided, when pressed, the raw material R in the cavity moves from the peripheral portion toward the center side as shown by the arrow N to fill the concave surface 14. Try to move sideways. However, before the raw material R sufficiently moves laterally, the raw material R is strongly pinched and hardened between the peripheral portion 11a of the upper die 11 and the lower die 12 ', and the raw material R is concave 14 You will not be able to get inside. As a result, as shown in FIG. 2B, voids V are generated in the uneven pattern portion 15, and the uneven pattern of the obtained molded article is not clearly transferred to the uneven pattern of the upper mold 11. It tends to be unclear.

On the other hand, when the convex surface 16 is provided on the lower mold 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, and the upper mold is not required. The raw material R is sufficiently filled in the concave-convex pattern portion 15 at a stage before the raw material R is tightly pressed between the peripheral edge portion 11 and the peripheral edge portion of the lower mold 12. As a result, the obtained molded article 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 arranged in the recess 17, and the spring 20 is provided at the entrance of the recess 17. Plate backed up by
Are arranged.

In FIG. 3 (b), the plate 21 has the recess 1
A rubber body 22 supported by the plate 21 is disposed in the vicinity of the middle of the inside of 7, and 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. The rubber body may have any shape such as a cylindrical shape, an elliptic cylindrical shape, and a prismatic shape.

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

[0030]

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

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

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing a molding die and a molding method according to a comparative example .

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

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

[Explanation of symbols]

10 Mold 11 Upper mold 12 Lower mold 13 lateral type 14 concave 15 uneven pattern 16 convex 17 recess 18 Rubber body 20 coil spring 21 plates 22 Rubber body

Front page continuation (72) Inventor Masaki Miwa 5-1, Koiemotocho, Tokoname City, Aichi Prefecture Inax Co., Ltd. (72) Inventor Akinori Miyazono 27, Nesakicho Higashishinkiri, Anjo City, Aichi Prefecture Miyazono Co., Ltd. (72) Inventor Haruo Matsunaga 27, Higashishinkiri, Nezaki-cho, Anjo City, Aichi Prefecture Miyazono Manufacturing Co., Ltd. (56) References JP-A-8-108419 (JP, A) JP-A-9-123139 (JP) , A) Japanese Unexamined Patent Publication No. 8-267431 (JP, A) Actual Development No. 1-166505 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B28B 1 / 00-23 / 22

Claims (4)

(57) [Claims] 1. A molding is produced from a plastic raw material using a molding die.
And have you to the molding method for press molding, the molding mold has a first mold and a second mold, the concave is provided on the cavity surface of the first mold, the second mold Convex surface facing the concave surface on the cavity surface
If a concave portion is provided on the convex surface and an elastic body is installed in the concave portion, and the amount of raw material charged is more than the planned amount,
A molding method, wherein a part of the raw material enters the concave portion due to the elastic body retreating due to the molding pressure at the time of molding . 2. The molding method according to claim 1 , wherein the concave surface of the first mold is provided with an uneven pattern portion for forming an uneven pattern on the molded body. 3. The recess according to claim 1 or 2,
A molding method, which is provided on the uppermost part of the convex surface of the first mold. 4. The odor according to any one of claims 1 to 3.
And the said elastic body is arrange | positioned flush with the surface of the convex surface of a 1st metal mold | die, The shaping | molding method characterized by the above-mentioned.