JPH02204013A - Mold and method for forming - Google Patents

Abstract

PURPOSE:To prevent the inclusion of air in forming material and the poor flow of the forming material from occurring at forming with low cost facilities by a method wherein the formation of an enclosed space around a forming cavity is made possible at the approach of an upper and a lower molds in the midway of mold clamping process and a member, which enlarges the volume of the enclosed space with no communication with the outside, is provided. CONSTITUTION:Under mold opening state, an annular forming material 8 is charged near the outside of an annular forming cavity 3, which is formed by an upper mold 1 and a lower mold 2. By approaching the molds 1 and 2 so as to pinch the forming material 8, an enclosed space 4 is formed by the forming material 8 and the upper and the lower molds 1 and 2. Next, by moving a piston 6 downwards, the volume in the enclosed space 4 increases and the pressure in the enclosed space 4 decreases and turns to be nearly vacuum pressure. Next, under the state that the piston 6 is held at the lower position, the upper and the lower molds 1 and 2 are clamped so as to abut against each other. After the completion of the filling of the forming material 8 in the forming cavity 4, the mold clamping is kept on and the forming is completed by applying the predetermined pressure and temperature to the molds.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a mold and a molding method, and in particular, when filling a molding cavity with a molding material, the pressure inside the mold is reduced to reduce the pressure generated in the molding material. The present invention relates to a mold and a molding method that prevent air entry and flow defects.

[Prior art and trying to solve! ! [Problem] Generally, when manufacturing a molded product by filling a molding material such as resin or rubber into a molding cavity in a mold, the lower part of the mold is lowered to prevent the molding during molding. The problem of air intrusion, which causes air bubbles in the material, and poor flow, which deteriorates the fluidity of molded material #4, has been improved. There is a molding machine with 11 knobs.

In other words, the second molding machine has a sealing device 22 in the mold 21.
will be established. L: In this mold 21, a vacuum pump 2;
When filling the molding material into the molding cavity in 21, the vacuum,
In the assembly [23], the inside of the C mold 21 was made to have a TiJ function under reduced pressure.

Name, 25 is 1-hot plate, 26 is lower heat plate, 27 is true 2-all 23? ■Control machine, pressure gauge 429 on the 2nd
is a pressure sensor.

However, in the above-mentioned conventional molding machine, in addition to the single round mold 21, many additional equipment such as a dense mold 1 device 22 and a vacuum pump 23 are required, and these additional equipment The problem was that it was expensive due to the installation costs and maintenance costs.

The present invention solves the above-mentioned problems of the conventional method, and thus eliminates the problems caused by molding and flow defects in the molding material during molding using inexpensive equipment. The purpose is to use a mold and a molding method that can be used as a mold.

[F1 stage for solving the problem] In order to achieve the above object, the pre-molding stage 1 of the present invention:, t,
When the LFO molds come into contact and separate, a molding cavity is formed with the square rod mold, and t, -1 in front of the middle of the mold clamping angle culm, nil F.
When approaching the type of! ,': The four walls of the molding cavity C, - density j・
・The molding method of the present invention has a structure in which a space can be formed, and an expanding member is provided to increase the volume of this sealed space without communicating with the outside. 1. When the lower molds come into contact, a molding cavity is formed with both H molds, and in 4), when the upper and lower molds approach during the mold clamping process, a sealed space is created around the molding cavity. Forming the molding material 14, the volume of the space is increased by increasing the volume of the space with a chamber expansion member, and the pressure is reduced, and the molding material 14 is then filled into the molding cavity under the pressure of the molding material 14. It has a means for molding.

[Effect]

By employing the above configuration and means, the present invention has the following features:
After loading the molding material into the mold, the mold is pushed close to form a closed space in the mold, the volume of the sealed space in the mold is increased, and the pressure inside this sealed space is reduced. By filling the molding material into the molding cavity, it is possible to prevent air entry and flow defects that occur in the molding material during molding.1.1.

(Actual example) Practical embodiments of the present invention shown in the drawings will be described below.

FIG. 1 shows an embodiment of a mold according to the present invention, and this mold is composed of an upper mold 1 and a closed mold 2 which are in contact with and separate from each other, and the upper mold 1 has an outer peripheral edge. A hole 1a is formed in the center of the hole 1a, which hangs downward, and a piston rod 6a, which is connected to the piston 6, is inserted into the hole 1a so as to be movable up and down, and its upper end extends above the upper mold 1. At the same time, a piston with a larger diameter than the piston rod a is disposed on the lower mold 2.

In addition, the lower mold 2 has four parts formed on its outer periphery that match the vertical F part of the upper mold l, and a contact surface f with -gl, which is an annular four part filled with the molding material 8. A molding cavity 5 is formed, and a cylinder part 7 for receiving the piston 6 is formed inside the annular molding cavity 5, and the piston 6 and the cylinder part 7 constitute the chamber expanding member 5.

Further, a packing 9 is provided on the inner circumferential surface of the hole 1a of the upper mold 1 to seal the piston rod 6a for 2.6 days when the piston rod 6a reciprocates. A gasket 10 is provided to seal between the two parts 6 and 7 during reciprocation within the part 7.

The process of molding using the mold configured as described above will be explained below.

First, as shown in FIG. 2 fa), an annular molding material 8 is charged near the outside of an annular molding cavity 3 formed by both molds 1 and 2 in an open state.

Next, enter the mold clamping process, bringing the upper and lower molds 1.2 closer together,
0]) in Fig. 2.

That is, both molds 1 and 2 are close to each other and the molding +4 material 8
The molds 1.2 are brought close to each other until they are sandwiched between the molds 1 and 2 of the upper F, and a sealed space 4 is formed by this molding material $48 and the upper and lower molds 1 and 2.

With the sealed space 4 shown in FIG. 2(b) formed, the piston rod 6a protruding from the second surface of the upper mold l is pressed downward as shown in FIG. The piston 6 located in the sealed space 4 is of the F type 2.
It is immersed in the cylinder part 7 formed in the 1: direction to increase the volume in the sealed space 4. At this time, the air in the cylinder section 7 located below the piston 6 is transferred to an air vent 1.1 provided at the bottom of the cylinder section 7 and communicating with the outside.
Run away more. Moreover, the length of the piston rod 6a is
When the piston 6 reaches the lowermost position of the cylinder portion 7, it matches the height of the upper surface of the upper mold 1.

Due to this downward movement of the piston 6, the sealed space 4
The volume inside increases and the pressure inside the sealed space 4 decreases, resulting in a state close to vacuum.

Next, the piston 6 remains in the downward position until the upper and lower molds 1 and 2 come into contact with each other, and the molds are clamped by a mold clamping mechanism (not shown).

At this time, the molding material 8 sandwiched between the molds 1 and 2 of the upper F and located in the sealed space 4 is
It becomes as shown in .

That is, the molded material 1B that becomes a part of the partition wall of the sealed space 4
is moved toward the molding cavity 3 due to the pressure difference with the outside of the mold, and is filled into the molding cavity 3.

After filling the molding material 8 into the molding cavity 4,
The molding is completed by applying a predetermined pressure and temperature while maintaining the mold clamping state shown in FIG. 2(e).

The relationship between the pressure in the sealed space 4 and the stroke amount of the press that presses down the piston rod 6a in each of the above molding steps is shown in FIG.
．． 2 and the molding material 8 to form a sealed space 4,
It can be seen that by pushing the piston loft 6a downward, the volume within the sealed space 4 increases and the pressure decreases, resulting in a state close to vacuum.

In the molding method according to the present invention in which molding is performed as described above, when the molding material 8 is filled into the molding cavity 3, the molding material 8 is in a reduced pressure state in the mold, so that the molding material In addition to preventing the air-intrusion phenomenon in 8, the molding material 8
This also prevents flow defects.

In other words, the molding material in the mold can be easily removed by simply forming the piston 6 and cylinder part 7 in the upper and lower molds 1 and 2 as described above, without installing large-scale additional equipment such as a vacuum pump as in the past. 8 can be filled into the molding cavity 4 in a near-vacuum state.

μ, in the above configuration, the piston rod 6a may be operated by its own operating mechanism, but the molds l, 2
It is also possible to operate the piston rod 6a with the mold clamping mechanism, and after loading the molding material 8 with the mold open,
A mold clamping mechanism (not shown) brings both molds 1.2 close to each other until the sealed space 4 is formed, then only the piston rod 6a is pushed down by the mold clamping mechanism, and finally the piston rod 6a and the upper mold 1 are It is also possible to press down and clamp the mold at the same time.

FIG. 4 shows another example of the mold according to the present invention. In the above embodiment, the molding material 8 is used as a part of the partition wall and cooperates with the upper and lower molds 1.2 to form the sealed space 4. The molding material 8 was filled into the molding space 4 using the difference between the pressure outside the mold and the pressure inside the sealed space 4. A pankin 12 is provided in one mold 2,
The sealed space 4 is formed only by the upper and lower molds 1.2, and then the molding cavity 3 in the sealed space 4 is filled with the molding material 8 using a filling device (not shown) capable of filling the molding material 8. You can.

〔Effect of the invention〕

The present invention is configured as described above, and by simply providing simple and inexpensive additional equipment to the mold, after loading the molding material into the mold, with a sealed space formed in the mold, By increasing the volume of the sealed space in the mold, the molding material loaded into this reduced pressure sealed space can be filled into the molding cavity under reduced pressure, and the process that occurs in the molding material during molding can be reduced.
This has excellent effects such as being able to prevent the occurrence of intrusion and poor flow.

[Brief explanation of the drawing]

1IA is a schematic diagram of a mold according to the present invention, FIG. 2(a)
(b) (c) (d) (el is a molding process diagram using the mold shown in Figure 1, Figure 3 is Figure 2 (al (b)
(C) (d) Diagram showing the relationship between the pressure in the sealed space and the stroke of the piston rod in each step of (e),
FIG. 4 is a schematic diagram showing another example of the mold according to the present invention, and FIG. 5 is a schematic diagram of a conventional molding machine. 6... Piston 6a... Piston rod 7... Cylinder part 8... Molding material 9.1 O512... Packing 11... ... Air vent 21 ... Molding mold 22 ... Sealing device 23 ... Vacuum pump 24 ... Piping l ... Upper mold 1a ... ... Hole 2 ... Lower mold 3 ... Molding cavity 4 ... Sealed space 5 ... Room expansion member Fig. 2 (0). 'xh knee. -, V' Ki 2 figure (b) r>0.7)゛No. 5 Figure 27 φl Works O Katayo Shintsubo -1 斤力 □ Tsuda procedural amendment (voluntary) 1, Meigyu no 2, Name of the invention 3. Name of the person making the amendment Address related to the case (Name) 4. Address of the agent 6. Subject of the amendment 1989 Special Apology Eaves No. 189930 Molding mold and molding method 5th floor, Marunaka Building, 3-8-13 Kudanminami, Chiyoda-ku, Tokyo (Tokyo 262-4761) NOK Co., Ltd. 1-12-15 (438) Shiba Daimon, Minato-ku, Tokyo Detailed explanation" ↓ ~ L, y (r door off; /11a"; Product 4? 1341u
Contents of the amendment (1) ``In other words, . . . . delete. (2) In the same book, page 9, line 5, "molding material #J8 is inside the mold" is corrected to "in the molding cavity." (3) Delete "[Figure 4 shows another example of the mold according to the present invention]" in lines 5 and 6 of page 10 of the same book. (4) “To form,
The pressure outside the mold may be used to fill the mold. ” was formed, but it is also possible to provide a packing in the mold and make the molding cavity into a sealed space by the packing, and by doing so, the above
Can handle product shapes other than circular and molding materials. ” he corrected. (5) In the same book, page 11, lines 11 to 13, "Fig. 4 is a schematic diagram." is replaced with "Fig. 4 is a schematic diagram Ld1 of a conventional molding machine." and correct it. (6) Figure 4 of the drawing will be deleted. (7) Correct 5th and 1 as shown in FIG. Complete 4 Figure 8, Attached catalog of antiques (1) Drawings (No. 4)

Claims (4)

[Claims] (1) When the upper and lower molds (1) and (2) contact and separate, both molds (1) and (2) form a molding cavity (3), and the molding space (3) is formed during the mold clamping process. Upper and lower molds (1), (2)
A sealed space (4) is formed around the molding cavity (3) when the
1. A molding die characterized by being provided with a chamber expansion member (5) that enlarges the volume of this sealed space (4) without communicating with the outside. (2) The chamber expansion member (5) includes a cylinder portion (7) provided in the lower mold (2) and opening into the sealed space (4), and a cylinder portion (7) provided in the upper mold (1). (7) The mold according to claim 1, comprising a piston (6) that is movable inside. (3) When the upper and lower molds (1) and (2) contact and separate, both molds (1) and (2) form a molding cavity (3), and the molding space (3) is formed during the mold clamping process. Upper and lower molds (1), (2)
A sealed space (4) is formed around the molding cavity (3) when the molding cavity (3) approaches, and the volume of this sealed space (4) is increased by the room expansion member (5) to reduce the pressure. ) A molding method characterized in that the molding material (8) loaded in the molding material (8) is filled into the molding cavity (3) under reduced pressure and molded. (4) The room expansion member (5) includes a cylinder portion (7) provided in the lower mold (2) and opening into the sealed space (4), and a cylinder portion (7) provided in the upper mold (1) and opened in the sealed space (4). (7) The molding method according to claim 3, further comprising a piston (6) whose interior is movable.