JP2002067073A - Molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a molded article having an outward appearance of high quality which is improved in the transferability of a minute shape of the molded article or a mold cavity surface which requires high accuracy, or the like. SOLUTION: This molding apparatus is equipped with a plurality of molds 10 each having a cavity 40 formed by a plurality of mold members 20 and 30, and each mold 10 is moved sequentially among a preliminarily heating process part, a resin filling process part, a cooling-pressurizing process part and a product removing process part so that a plurality of processes are executed concurrently. The mold 10 has a centering location part which is constituted of recessed and projecting structures 22 and 32 fitted to each other between the mold members 20 and 30 and regulates the movement of the mold members 20 and 30 in a direction other than the direction of pressurization of resin, while the cooling-pressurizing process part has a cooling control means for controlling a cooling speed of the mold 10 and a compressing means which compresses the resin by moving the mold members 20 and 30 of the mold 10 in the direction of pressurization in conformity with the shrinkage of the resin consequent on the cooling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding device for a high-precision molded product and a fine-transfer molded product.

[0002]

2. Description of the Related Art Injection molding and the like are used for molding synthetic resin molded articles requiring high precision. There is also known a technique for improving the accuracy of a molded product by applying a large clamping force or applying a long cooling time as a molding condition. For example, a molding apparatus disclosed in Japanese Patent Publication No. 1-367768 has an injection molding machine and a plurality of press machines, and has a plurality of dies for individually moving between the injection molding machine and the plurality of press machines. It is characterized by having a device for individually pressing a mold filled with resin by an injection molding machine with a press machine and cooling while controlling the temperature.

In the above-mentioned prior art, it is stated that the molding time can be shortened by separately performing the resin injection and filling steps and the cooling step at different locations. It is said that a high-precision molded product can be efficiently produced by performing fine pressure and temperature control during cooling with a plurality of press machines.

[0004]

However, in the above-mentioned prior art, there is a problem that the resin pressure in the cavity of the molding apparatus cannot be finely controlled. There is also a problem that molding requiring high transfer of fine shapes cannot be performed.
An object of the present invention is to provide a molded article requiring high precision or
An object of the present invention is to make it possible to produce a high-quality appearance molded product in which transferability of a fine shape or the like of a mold cavity surface is improved.

[0005]

A molding apparatus according to the present invention includes a plurality of dies that form a cavity by combining a plurality of mold members, and a preheating step of preheating each of the dies. Section, a resin filling step section for filling the cavity with a thermoplastic resin from the resin supply device, a cooling / pressing step section for pressurizing while cooling the resin in the cavity, and a product removal step section for taking out a molded product from the mold. This is a molding apparatus that moves a plurality of steps sequentially to perform a plurality of processes at the same time. The mold has a spigot portion having an uneven structure fitted between the mold members and configured to restrict movement of the mold members in directions other than the pressing direction of the resin. The cooling and pressurizing step includes a cooling control unit that controls a cooling rate of the mold, and a compression unit that compresses the resin by moving the mold member in the pressing direction in accordance with shrinkage of the resin accompanying cooling. And

[0006] The mold member constituting the spigot portion may be composed of a plurality of divided members. The mold may further include pressure detecting means for detecting a pressure in the cavity. The compression unit of the cooling and pressurizing unit may further include a pressure detection unit that detects a pressure applied to the compression unit. The cooling and pressurizing step may further include a closing means for closing a resin supply unit provided in the mold for filling the cavity with the resin. The resin filling step may further include a direct filling means for directly filling the resin from the resin supply device into the cavity.

[0007] The resin filling step may further include vacuum evacuation means for sealing the molding space including the cavity and a portion for filling the cavity with the resin, and evacuating the molding space. The resin filling step may further include a vibrating means for vibrating the mold. The preheating step may further include a plurality of heating members for preheating the mold by contacting the mold surface from different directions. A mold that moves between the respective process units may be constituted by the plurality of mold members and a protruding pin for taking out a molded product from the cavity.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Basic Structure of Molding Apparatus] As shown in FIG. 1, the overall structure of the molding apparatus includes a preheating step A, a resin filling step B, a cooling / pressing step C, and a product unloading step. D is provided. Although not shown, each of the process units A to D
During the process, the molds 10 are circulated and moved in the order of the process sections A to D.
Transport means such as a conveyor for transporting the paper. A plurality of steps such as a resin filling step and a cooling and pressurizing step, or a cooling and pressurizing step and a product removing step may be executed at the same place using at least a part of a common device. In this case, some of the process units A to D may be used in some cases.

While the mold 10 is being conveyed between the process sections A to D, the process of manufacturing a molded product is sequentially performed. As shown in FIG. 2, the mold 10 is composed of two members, an upper mold part 20 and a lower mold part 30, and a gap corresponding to the shape of a molded product to be manufactured is provided between the two mold parts 20, 30. That is, cavity 4
0 is configured. In the cavity 40, the protruding portion 22 protruding below the upper mold portion 20 is vertically fitted into the concave recess 32 of the lower mold portion 30. The fitting structure of the convex portion 22 and the concave portion 32 becomes a spigot portion. The upper mold part 20 and the lower mold part 30 are movable in the vertical direction, but are restricted from moving in the horizontal direction.

In the center of the lower surface of the upper mold portion 20, a resin supply hole 28 is provided.
Penetrates into the cavity 40. Upper mold part 20
The pressure sensor 26 detects the internal pressure of the cavity 40, that is, the pressure of the filled resin, and the temperature sensor 2 detects the temperature of the mold 10 near the inner surface of the cavity 40.
4 is provided. The lower mold part 30 has a protruding pin 34 that can move up and down and protrudes and removes a molded product in the cavity 40.
It has. However, the mold 10 is not provided with a mechanism for driving the protruding pin 34. A plurality of molds 10 having the above structure are prepared.

As shown in FIG. 1, the mold 10 is sequentially sent to each of the process sections A to D by a conveying means such as a conveyor,
A predetermined processing operation is performed in each of the process units A to D.
If the mold 10 is disposed in each of the process sections A to D, the respective processing operations can be performed simultaneously in each of the process sections A to D. [Preheating Step A] FIGS. 3 and 4 show the structure of the preheating step A and the processing steps therein. The preheating step A includes a base 50 forming a bottom surface, and a heating space in which a space above the base 50 is surrounded by a heat insulating material 51.

In the heating space, heating plates 52 and 54 are arranged above and below the mold 10, respectively. The heating plates 52 and 54 are in contact with the upper surface of the upper mold portion 20 and the lower surface of the lower mold portion 30, respectively. The heating plate 56 is also arranged so as to contact the side of the mold 10. Although not shown in the drawing, heating plates 56 are arranged not only on the left and right sides of the mold 10 but also on the front and rear sides. Each heating plate 52, 5
4 and 56 are driven by hydraulic cylinders 53 and 57. Until the mold 10 is transported to the preheating step A,
The heating plates 52, 54, and 56 are arranged on the heat insulating material 51 side, and move to a position where the mold 10 comes into contact with the mold 10 when the mold 10 is arranged at a predetermined position. Heating plates 52, 54, 5
The heater 6 has a built-in heater 58 therein, and contacts the mold 10 to heat the mold 10.

As shown in FIG. 4, when the preheating step is completed, the respective heating plates 52, 54, 56 are separated from the mold 10, and the mold 10 can be carried out from the preheating step part A. Heating plate 5 from multiple directions around mold 10
By performing the preheating by bringing the layers 2, 54, and 56 into contact with each other, the heating efficiency of the mold 10 is increased, and the heating time can be reduced.
By surrounding the periphery of the heating space with the heat insulating material 51, the heating space can be thermally isolated from the outside, and the heating efficiency is increased. The temperature of the mold 10 is measured by a temperature sensor 24 installed in the mold 10, and the mold 10 can be heated to a predetermined temperature.

As for the mold temperature, it is desirable to heat the resin used for molding to near the glass transition point. Mold 10
Is heated to a temperature equal to or higher than the glass transition temperature of the resin, the distribution of the skin layer and the core layer in the molded product can be prevented, and a highly precise molded product without distortion can be produced. When the mold temperature is heated to a temperature equal to or higher than the glass transition temperature of the resin, the fluidity of the resin is increased, the resin is easily filled into the minute shape of the mold cavity surface, and high transfer molding of the minute shape is easily performed. In the conventional general injection molding, if the temperature of the mold 10 is raised to the glass transition temperature of the resin, it takes time to cool the mold 10 from the glass transition temperature to the removal temperature of the molded product. This results in low productivity.

However, in the present invention, since the plurality of dies 10 are moved between the respective steps A to D independently of the respective steps A to D, the molding cycle as a whole can be shortened. By heating the mold 10 to near the glass transition point of the resin, the resin pressure in the resin filling step may be low. Therefore, the rigidity of the mold 10 can be reduced and the structure of the mold 10 can be simplified as compared with a normal injection mold or a press mold. If the structure of the mold 10 can be simplified, the heat capacity of the mold 10 itself becomes small, and the mold 10
The heating and cooling efficiency is improved, which is effective in shortening the molding cycle.

[Resin Filling Step B] As shown in FIG.
The mold 10 that has been preheated is sent to the resin filling step B, and the molding resin P is filled into the cavity 40 of the mold 10. The resin filling step B includes die plates 60, 60 arranged vertically, a temperature control block 62 and a mold clamper 64 arranged on the surface of the die plate 60 via a heat insulating plate 61. The temperature control block 62 has a built-in heater 63. Upper and lower temperature control block 62
When the upper surface of the upper mold portion 20 and the lower surface of the lower mold portion 30 of the mold 10 are brought into contact with each other and locked by the mold clamper 64, the mold 10 is mounted in the resin filling step B.

In this state, the upper mold part 20 and the lower mold part 30 are not completely clamped, and the initial opening G ₀ is between the upper mold part 20 and the lower mold part 30. is open. The shape of the cavity 40 is slightly larger than the shape of the finally manufactured molded product. However, as mentioned above,
Since the convex portion 22 of the upper mold portion 20 and the concave portion 32 of the lower mold portion 30 are vertically fitted to each other to form a spigot portion, resin leaks between the upper mold portion 20 and the lower mold portion 30. There is no gap that flows or flows backward. The supply port 67 of the resin supply nozzle 66 is fitted into the resin supply hole 28 of the upper mold section 20. The supply port 67 opens directly into the cavity 40. The resin P is pressure-fed to the resin supply nozzle 66 from a resin supply device (not shown).

The resin P is filled in the cavity 4 of the mold 10.
0 is performed while maintaining the glass transition temperature raised in the preheating step A. For this purpose, it is effective to operate the heater 63 of the temperature control block 62 in advance. In the above embodiment, the resin supply path such as a sprue runner provided in a normal molding apparatus is omitted, and the cavity 40 is directly supplied from the supply port 67 of the resin supply nozzle 66.
Is filled with resin P. As a result, the time for cooling the sprue runner or the like is not required in the cooling performed in the subsequent step, and the cooling time can be reduced. As a means for directly supplying the resin P to the cavity 40, a long nozzle or a hot runner can be used.

[Cooling and Pressurizing Step C] As shown in FIGS. 6 and 7, the mold 10 after the filling of the resin P is sent to the cooling and pressurizing step C. In the cooling and pressurizing step C, a temperature control block 72 and a mold clamper 74 are provided on a pair of upper and lower die plates 70, 70 via a heat insulating plate 71, respectively. A temperature control element 73 is built in the temperature control block 72 so that the temperature of the temperature control block 72 can be controlled. The upper and lower die plates 70, 70 have a press mechanism, and can narrow, open, and press each other.

Upper mold part 20 and lower mold part 30 of the mold 10
Is fixed to the upper and lower die plates 70 by the mold clamper 74 in the same manner as in the resin filling step B. The temperature control block 7 is provided in the resin supply hole 28 of the upper mold portion 20.
An obturator plug 75 protruding from the lower end of 2 is fitted. The closing plug 75 may be formed integrally with the temperature control block 72, or may be constructed by assembling the divided parts. If the resin supply hole 28 is securely closed with the closing plug 75, when the resin P is pressed and compressed,
The resin P can be prevented from leaking or flowing backward from the resin supply hole 28, and the resin pressure in the cavity 40 can be finely controlled.

By controlling the temperature of the temperature control block 72, the resin P in the cavity 40 is cooled. At the same time as cooling, the distance between the die plates 70,
0 and the lower mold part 30 are clamped, and the resin P in the cavity 40 is
Compress. The resin P shrinks when cooled. For a molded product requiring high precision, it is desirable that the resin P in the cavity 40 be uniformly shrunk in the cooling step and solidified without distortion. For this reason, in the cooling step, it is effective to apply pressure to the resin P in the cavity 40 so as to compensate for a decrease in the resin pressure in the cavity 40 due to shrinkage of the resin P while gradually cooling the mold 10. is there.

When the resin P is cooled after the upper mold part 20 and the lower mold part 30 are completely clamped, the die plate 70
The upper mold part 20 and the lower mold part 30
Just receiving pressure on the mating surface with
The pressure of the resin P within 0 cannot be controlled. However, as described above, at the start of the cooling and pressurizing step, the initial opening amount G between the upper mold portion 20 and the lower mold portion 30 is increased.
_{When the} upper mold part 20 and the lower mold part 30 are clamped so that the opening amount G gradually decreases from this state, the resin P in the cavity 40 is shrunk by cooling. The resin pressure in the cavity 40 can be appropriately and finely controlled. As described above, the upper mold part 20 and the lower mold part 30 are vertically slidable with the convex part 22 and the concave part 3.
2 and the cavity 4
While maintaining the hermeticity of 0, the thickness of the cavity 40 in the vertical direction is gradually reduced, and only the resin P is compressed without receiving pressure at the abutting surface between the upper mold section 20 and the lower mold section 30. I can go.

As the temperature control element 73 installed in the temperature control block 72, a heater, an oil temperature control tube, or the like is used. The temperature of the temperature control block 72 is preferably set near the glass transition temperature of the resin P at the beginning of the cooling and pressurizing step, and then cooled at a cooling rate of 1 ° C. to 5 ° C./min. On the other hand, high transferability of the fine shape of the mold cavity surface is particularly required, and for the molded product where the distortion inside the molded product is not so important, it is necessary to rapidly cool the mold in the cooling process to shorten the cycle. desirable. The temperature of the temperature control block 72 at this time is desirably set to be equal to or lower than the solidification temperature of the resin P from the initial state.
As the temperature control element 73 suitable for such rapid cooling, a water temperature control tube, a Peltier element, or the like can be used.

In addition to cooling from the temperature control block 72, the space in the cooling and pressurizing step is thermally cut off from the surroundings,
The cooling effect can be enhanced by a structure such as blowing cooling air on the surface. By keeping the temperature control block 72 insulated from the die plate 70 by the heat insulating plate 71, the temperature of the mold 10 can be controlled efficiently. As shown in FIG. 7, when the compression of the resin P is completed, the upper mold part 20 and the lower mold part 30 are completely clamped. Cooling may be ended simultaneously with the end of the compression, or further cooling may be performed after the end of the compression.

By performing the cooling and pressurizing step as described above, the resin P in the cavity 40 can be cooled while being precisely controlled. By appropriately controlling the pressure of the resin P, the dimension and shape of the finally manufactured molded product become accurate, and the fine irregularities provided on the inner surface of the cavity 40 are accurately transferred to the molded product. Will be. [Product Removal Step D] As shown in FIGS. 8 and 9, the mold 10 after the cooling and pressurizing step is sent to the product removal step D. The product removal process section D includes a pair of upper and lower die plates 8.
Mold clamps 83 are provided at 0 and 82, respectively.
The lower die plate 80 is provided with the protruding pin 34 of the mold 10.
And a projecting cylinder 84 for driving

With the upper die portion 20 and the lower die portion 30 attached to the upper and lower die plates 80 and 82 by the die clamps 83, respectively, the upper die plate 82 is raised and the upper die portion The part 20 is separated and the mold is opened. The lower mold part 20 and the upper mold part 30 are smoothly opened by being guided by the spigot part formed by the convex part 22 and the concave part 32. In the cavity 40, a molded article M obtained by cooling and hardening the resin P is formed. Thereafter, as shown in FIG.
4 to raise the protruding pin 34 of the mold 10,
The molded article M in the cavity 40 is projected above the cavity 40. Molded product M taken out of cavity 40
Is carried out using an appropriate transporting means (not shown) or manually.

In each of the process sections A to D described above, a separate mold 10 is disposed in each process section, and each of the process sections A to D is provided.
The operations in D can be performed independently and simultaneously in parallel. As a result, shortening of molding cycle and high precision molded products,
In addition, it is possible to produce a high-transfer molded product having a fine shape. 10 and 11, the embodiment shown in FIGS. 10 and 11 shows the mold 10 arranged in the cooling and pressurizing step C. A part of the structure of the embodiment and the mold 10 will be described. Are different. The structure of the upper mold part 20 of the mold 10 is common to the above embodiment.

The lower mold part 30 is divided into a plurality of members. That is, the tube portion 37 is provided on the substrate portion 35 having a hole in the center, and the nest portion 36 is mounted inside the hole of the substrate portion 35 and the inside of the tube portion 37. The inner surface of the cylindrical portion 37 becomes the concave portion 32 forming the spigot portion. The nesting part 36 is vertically movable with respect to the substrate part 35 and the cylinder part 37. The upper surface of the nested portion 36 and the inner surface of the cylindrical portion 37 constitute a mold surface. The bottom surface of the nesting portion 36 is in contact with the upper end of a compression rod 76 that moves up and down through the lower die plate 70. In the cooling and pressurizing step, the compression rod 76 is moved up while the mold 10 is closed, so that
Is raised to compress the resin P in the cavity 40.
At this time, the moving amount of the compression rod 76, that is, the amount of compression of the resin P, is desirably set to be about 1% to 10% of the thickness of the final molded product M.

In the above embodiment, the resin filling in the previous process
Initial opening amount G of the mold 10 in the process section B ₀Just open
[Refer to FIG. 5] The mold 10 is gradually tightened in the cooling and pressurizing step.
Operation was performed, but in this embodiment,
The mold 10 may be left completely closed. Upper die 2
0 or the die plate 70 is moved up and down to
No need to finely control opening and closing. Resin filling process
Vertical movement of the upper mold part 20 in the part B and the cooling / pressing process part C
Is not performed, so that the upper mold part 20 is
It does not need to be attached to the plate,
And shorten the molding cycle.

The compression rod 76 can also be used for taking out the molded product M. As shown in FIG.
In the above, after the mold 10 is opened and the upper mold part 20 is removed, the compression rod 76 is operated to raise the nesting part 36, and the molded article M is lifted to above the lower mold part 30, The product M can be taken out. In this embodiment, the mold 10 is transferred from the cooling and pressurizing process section C to the product removal process section D, and the compression rod provided on the die plate 80 of the product removal process section D is used. May be driven, but the molded product M can be taken out while the mold 10 is arranged in the cooling and pressurizing step C. That is, in the cooling and pressurizing step C, after the resin P is cooled and pressurized to obtain a molded product M, the mold 10 is opened at the position as it is, and the compression rod 76 is operated to perform molding. The product M can be taken out. In this case, both the cooling and pressurizing step and the product removing step are performed in the cooling and pressurizing step C.

[Pressure Sensor / Temperature Sensor] The operation of the pressure sensor 26 and the temperature sensor 24 provided in the mold 10 will be described. As shown in FIG. 2, the pressure sensor 26 and the temperature sensor 24 have a cable 2 for extracting detection information.
5 and 27. When the mold 10 is disposed in each of the process sections A to D, the cables 25 and 27 are connected to a control device provided in each of the process sections A to D as necessary, so that each process based on pressure and temperature is performed. Work can be controlled.

As the pressure sensor 26, a quartz piezoelectric sensor or a strain gauge sensor can be used. The mounting position and the mounting number of the pressure sensor 26 are set according to conditions such as the structure of the mold 10 and the necessity of pressure detection, and are not particularly limited. As the temperature sensor 24, a thermocouple or an infrared temperature sensor can be used. The mounting position and the number of the temperature sensors 24 are not particularly limited. In FIG. 2, the pressure sensor 26 and the temperature sensor 24
Is attached, but it can also be attached to the lower mold section 30 or to both the upper mold section 20 and the lower mold section 30.

The pressure sensor 26 and the temperature sensor 24
It is effective for achieving high precision of molding and high transferability of fine shapes. 6 and 7, the operation of the temperature control element 73 of the temperature control block 72 can be controlled by information from the temperature sensor 24. Specifically, at the beginning of the cooling and pressurizing step, the temperature of the temperature control block 72 detected by the temperature sensor 24 is set near the glass transition temperature of the resin P. 1 ℃ ～ 5
The cooling can be performed by controlling the operation of the temperature control element 73 so that the cooling rate becomes ° C / m. By using the temperature sensor 24, the temperature of the resin P can be finely controlled.

The resin pressure in the cavity 40 is measured by the pressure sensor 26, and if the die plate 70 is actuated in the compression direction by an amount corresponding to the pressure decrease due to the cooling of the resin P, the resin pressure decrease in the cavity 40 is compensated. can do. As a result, it is possible to produce a molded article M from which internal distortion has been successfully removed. Even when the above-described mold 10 is rapidly cooled, the temperature of the temperature control block 72 can be set to be equal to or lower than the solidification temperature of the resin P based on the information of the temperature sensor 24. Also at this time, the operation of the die plate 70 is controlled based on the information of the pressure sensor 26, and the decrease in the resin pressure can be compensated for by the compression of the resin P.

[Pressure Detecting Means] In the above-described embodiment, the pressure sensor 26 is attached to the mold 10 to detect the resin pressure. However, a pressure detecting means may be provided in the cooling / pressurizing step C. . As shown in FIG.
By installing the load cell 29 at the side, the reaction force applied to the compression rod 76 can be directly measured. The reaction force applied to the compression rod 76 corresponds to the resin pressure in the cavity 40. When the compression rod 76 is driven by a hydraulic cylinder, a pressure sensor for detecting oil pressure may be provided in the hydraulic cylinder or the hydraulic piping. When the compression rod 76 is driven by a motor, a detector that detects the load on the motor can be used as pressure detection means.

If the compression rod 76 is provided with a pressure detecting means, the resin pressure in the cavity 40 is estimated by the pressure detecting means, and the compression rod 76 is actuated in the compression direction by an amount corresponding to the reduced pressure, whereby the resin pressure is reduced. The decrease can be compensated for. When the resin P is compressed by the operation of the die plate 70 without using the compression rod 76,
The same control as described above can also be performed by estimating the resin pressure in the cavity 40 from the pressure applied to the die plate 70 with a pressure detector installed behind the die plate 70. In the above embodiment, it is not necessary to move the pressure sensor 26 between the steps A to D together with the mold 10. There is no need to connect or disconnect the cable of the pressure sensor 26.

[Evacuation Means] In the embodiment shown in FIG. 14, the molding space is evacuated in the resin filling step B. The basic structure of the resin filling step B is the same as that of the above-described embodiment. A sealing plate 92 is arranged around the outer periphery of the mold 10, the temperature control block 62, the heat insulating plate 61, and the mold clamp 64. In the heat insulating plate 61, seal members 93 are arranged near upper and lower ends of a surface facing the sealing plate 92, respectively. When the sealing plate 92 comes into contact with the sealing material 93, the internal space of the sealing plate 92 closed by the sealing material 93, that is, the molding space is in a sealed state. As the sealing material 93, silicone rubber or the like which can be used at a high temperature is desirable.

Vacuum evacuation path 91 opening to a part of molding space
Is connected to a vacuum pump 90. Vacuum exhaust path 91
Is opened to the lower surface of the temperature control block 62 on the side of the mold 10, penetrates the temperature control block 62, the heat insulating plate 61 and the upper die plate 60, and is disposed from the side surface of the die plate 60 to the vacuum pump 90. ing. By operating the vacuum pump 90, the molding space can be evacuated. The sealing plate 92 is connected to an operating rod 94 such as a hydraulic cylinder or an air cylinder, and protrudes upward from the lower die plate 60 to form upper and lower die plates 60.
It is slidably mounted in a vertical direction between a position covering the space between the die plates 60 and a position accommodated below the lower die plate 60.

The mold 10 is moved from the previous step to the resin filling step B
Is transported to the upper and lower die plates 6 with the sealing plate 92 housed below the die plate 60.
The mold 10 can be mounted between 0 and 60. After the mold 10 is mounted at a predetermined position, a hydraulic cylinder or the like is operated to raise the sealing plate 92 to seal the molding space. By vacuum evacuation of the molding space surrounded by the sealing plate 92, when the cavity 40 of the mold 10 is filled with the resin P, the resin P is reliably formed according to the fine shape provided on the mold surface of the cavity 40. Is filled. As a result, the transferability of the fine shape to the molded article M is improved.

The degree of evacuation by the vacuum pump 90 is as follows.
Vacuum in the cavity 40 is preferably set to be 10 ⁰ ~10 ² Torr. [Vibration means] In the embodiment shown in FIG. 15, vibration is applied at the time of resin filling in the resin filling step B. A vibrator 100 that contacts the outer peripheral side surface of the mold 10 is
It has. The vibrator 100 generates minute vibrations using an ultrasonic vibrator, a piezo element, or the like.

The resin P is filled into the cavity 40 of the mold 10 while applying a minute vibration to the mold 10 by the vibrator 10. Vibration is applied to the mold 10 and the resin P, so that the resin P is satisfactorily filled into the finely shaped portion of the mold surface of the cavity 40. As a result, the mold transferability of the finely-shaped portion to the molded article M is improved. It is desirable that the vibration be performed at an amplitude of about 5 to 20 μm and a frequency of about 15 to 25 kHz. In the illustrated embodiment,
As the mold 10, the mold 10 having a divided structure including the substrate portion 35, the cylindrical portion 37, and the insert portion 36 is used.
The lower die plate 60 is provided with a lifting rod 68 for raising and lowering the nesting portion 36.

[0042]

The molding apparatus of the present invention is provided with the spigot portion having the above-described structure. In the cooling and pressurizing step, while controlling the cooling rate of the mold, the inside of the cavity is adjusted in accordance with the cooling shrinkage of the resin in the cavity. Since the resin can be compressed, it is possible to finely control the resin pressure in the cavity. As a result, a highly accurate molded product can be obtained.
Further, the fine shape of the cavity surface can be accurately transferred to the molded product. If the mold member forming the spigot portion is composed of a plurality of divided members, the movement of the mold from the cavity compression to the product removal step becomes unnecessary, and the clamping of the mold in the compression step becomes unnecessary.

If the mold is further provided with a pressure detecting means for detecting the pressure in the cavity, it is possible to finely control the resin pressure in the cavity. If the compression means in the cooling and pressurizing step further includes a pressure detection means for detecting the pressure applied to the compression means, the resin pressure in the cavity can be finely controlled and the mold structure can be simplified. If the cooling and pressurizing step further includes a closing means for closing the resin supply unit provided in the mold for filling the cavity with the resin, the resin pressure in the cavity can be finely controlled.

If the resin filling step further comprises a direct filling means for directly filling the cavity with the resin from the resin supply device, the cooling time can be shortened and the mold structure can be simplified. If the resin filling step further includes vacuum exhaust means for closing the molding space including the cavity and the resin filling portion into the cavity and evacuating the molding space, high transfer of the fine shape can be achieved in a short molding cycle. Will be possible. If a vibrating means for vibrating the mold is further provided in the resin filling step, high transfer of a fine shape can be performed in a short molding cycle.

If the preheating step further comprises a plurality of heating members for preheating the mold by contacting the mold surface from different directions, the mold heating time can be reduced. If the mold moving between the respective process sections is composed of the plurality of mold members and the protruding pins for taking out the molded product from the cavity, the time for heating and cooling the mold can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a molding apparatus representing an embodiment of the present invention.

FIG. 2 is a sectional view of a mold.

FIG. 3 is a sectional view of a preheating step.

FIG. 4 is a cross-sectional view of a stage at the end of a preheating step.

FIG. 5 is a sectional view of a resin filling process section.

FIG. 6 is a cross-sectional view of a cooling and pressurizing process unit.

FIG. 7 is a cross-sectional view of the end stage of the cooling and pressurizing process.

FIG. 8 is a cross-sectional view of a product removal process section.

FIG. 9 is a cross-sectional view showing an operation state of a product removal process.

FIG. 10 is a cross-sectional view in a cooling and pressurizing step of the embodiment in which the structure of the mold is changed.

FIG. 11 is a sectional view showing an operation state of the compression rod.

FIG. 12 is a cross-sectional view of a product removal process.

FIG. 13 is a sectional view showing a modified example of the pressure detecting means.

FIG. 14 is a cross-sectional view of a molding apparatus provided with a vacuum exhaust unit.

FIG. 15 is a cross-sectional view of a forming apparatus provided with a vibration unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 mold 20 upper mold portion 22 convex portion (inlay portion) 28 resin supply hole 30 lower mold portion 32 concave portion (inlay portion) 34 protruding pin 40 cavity 24 temperature sensor 26 pressure sensor 52, 54, 56 heating plate 66 resin supply nozzle 72 Temperature control block 75 Stopper 84 Projection cylinder A Preheating step B Resin filling step C Cooling and pressurizing step D Product unloading step P Resin M Molded product

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naoyuki Kondo 1048 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Works F-term (reference) 4F202 AP02 AR02 AR06 CA11 CB01 CK18 CK43 CK83 CM02 CN05 CP07 4F206 AP025 AR025 AR064 JA07 JM16 JN14 JN25 JN33 JN37 JP13 JQ81 JT06

Claims (10)

[Claims] 1. A plurality of dies that form a cavity by combining a plurality of mold members, each of the dies is provided with a preheating step for preheating the dies, and a thermoplastic resin is supplied from a resin supply device into the cavities. A plurality of processes are performed simultaneously by sequentially moving between a resin filling process unit for filling, a cooling / pressing process unit for pressurizing while cooling the resin in the cavity, and a product removing process unit for removing a molded product from a mold. The molding apparatus, wherein the mold has an inlay portion which has an uneven structure fitted between the mold members and is restricted from moving the mold members in directions other than the pressing direction of the resin, A cooling and pressurizing step, a cooling control unit that controls a cooling rate of the mold, and a compression unit that compresses the resin by moving the mold member of the mold in a pressing direction in accordance with shrinkage of the resin accompanying cooling. Molding characterized by having Location. 2. The molding apparatus according to claim 1, wherein the mold member forming the spigot portion comprises a plurality of divided members. 3. The molding apparatus according to claim 1, further comprising a pressure detecting means for detecting a pressure in the cavity in the mold. 4. The molding apparatus according to claim 1, wherein the compression means of the cooling and pressurizing step further includes a pressure detection means for detecting a pressure applied to the compression means. Molding equipment. 5. The molding apparatus according to claim 1, wherein the cooling and pressurizing step includes a resin supply unit provided in the mold for filling the cavity with the resin. A molding apparatus, further comprising a closing means for closing. 6. The molding apparatus according to claim 1, wherein the resin filling step further includes a direct filling means for filling the cavity directly with the resin from the resin supply device. Characteristic molding equipment. 7. The molding apparatus according to claim 1, wherein the resin filling step hermetically seals a molding space including a cavity and a portion for filling the cavity with the resin, and evacuates the molding space. A molding apparatus, further comprising a vacuum exhaust means for performing a vacuum evacuation. 8. The molding apparatus according to claim 1, further comprising a vibrating means for vibrating a mold in said resin filling step. 9. The molding apparatus according to claim 1, wherein the preheating step includes a plurality of heating members for preheating the mold by contacting the mold surface from different directions. A molding device, further comprising: 10. The molding apparatus according to claim 1, wherein the mold that moves between the respective process units includes the plurality of mold members and a protruding pin that removes a molded product from a cavity. A molding apparatus characterized by being performed.