JP3240877B2 - Injection compression molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection compression molding apparatus for molding a resin molded plate such as a magneto-optical disk.
The present invention relates to an injection compression molding apparatus capable of achieving a high cycle of production of a resin molded plate.

[0002]

2. Description of the Related Art Since high precision and high precision are required for resin molded plates such as magneto-optical disks, the resin filled in the cavity is forcibly pressurized to prevent sink of the resin at the time of curing. In general, injection molding is performed using an injection compression molding apparatus.

As shown in FIG. 2, this type of injection compression molding apparatus includes a fixed mold 3 and a movable mold 4 which form a cavity C11 for a resin molded plate 1, and a cavity C11 through a resin passage R11. Injection means such as an injection nozzle 6 for injecting the resin, and a hydraulic cylinder (not shown) for forcibly pressing the resin in the cavity C11 by minutely moving the movable mold 4 toward the cavity C11 after the cavity C11 is filled with the resin. And the basic configuration.

Further, in such an injection compression molding apparatus, the resin molding plate 1 formed in the cavity C11 or the resin passage is formed for the purpose of accelerating the curing of the resin molding plate 1 and increasing the cycle of the production. A cooling water passage R12 for cooling the sprue 7 formed in R11 has been proposed.

[0005]

However, in such an injection compression molding apparatus, after the cavity C11 is filled with the resin, the movable mold 4 is slightly moved to the cavity C11 side to forcibly remove the resin in the cavity C11. When hardening of the sprue 7 and the resin molding plate 1 is performed by flowing the cooling water through the cooling water flow passage R12, the temperature of the root 7a of the sprue 7 on the resin molding plate 1 side as shown in FIG. The temperature is higher than the temperature of the resin molded plate 1. Accordingly, the hardening of the root portion 7a of the sprue 7 is slower than the hardening of the resin molded plate 1. As described above, the balance of the progress of the curing is lost at the base 7a of the resin molded plate 1 and the sprue 7.
In order to shorten the molding cycle, it has been an issue to shorten the sprue solidification time. To speed up sprue solidification, it is conceivable to lower the water temperature of the cooling water flow passage R12 for sprue cooling. However, when the water temperature is lowered, the temperature affects the nested components around the sprue 7 and a temperature difference occurs between the inner peripheral portion and the outer peripheral portion of the cavity C11 surface. As a result, internal distortion occurs in the resin molded plate 1. For this reason, it was difficult to further increase the cycle.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an injection compression molding apparatus capable of further increasing the cycle of manufacturing a resin molded plate.

[0007]

According to the present invention, there is provided an injection compression molding apparatus, comprising: a mold for forming a cavity for a resin molding plate; an injection means for injecting a resin into the cavity through a resin passage; A cooling water flowing means for cooling the formed resin molded plate or sprue formed in the resin passage, the cooling water flowing means,
Cooling water distribution means for the resin molded plate for cooling the resin molded plate,
The sprue cooling water circulation means is formed in a band shape surrounding the sprue and cools the sprue. The sprue cooling water circulation means distributes cooling water having a lower temperature than the cooling water of the resin molding plate cooling water circulation means. It is allowed, on the periphery of the cooling water circulation means for sprue, characterized in that the insulating sleeve is provided as insulating means for thermally insulating between the cooling water circulation means and a resin molded plate for sprue.

[0008]

According to the injection compression molding apparatus of the first aspect, since the heat insulating means for insulating the resin molding plate is provided around the sprue cooling water flowing means, the cooling water of the sprue cooling water flowing means is provided. Thereby, it is possible to prevent the resin molded plate from being cooled. In addition, since the cooling water flowing means for the sprue circulates cooling water at a lower temperature than the cooling water of the cooling water flowing means for the resin molded plate, cooling of the sprue having a higher temperature than the resin molded plate, that is, curing You can speed up the process. Thereby, the difference in the degree of progress of curing between the resin molded plate and the sprue can be reduced.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a main part of one embodiment of an injection compression molding apparatus 100 according to the present invention.
00 is an embodiment in the case where the optical disk 1A is injection-molded as a resin molded plate.

The injection compression molding apparatus 100 generally includes a mold mechanism 50 including a fixed mold section 51 and a movable mold section 52, an injection mechanism 60 for injecting resin from the injection nozzle 61 to the mold mechanism 50, and a mold mechanism. It comprises a mold clamping mechanism (not shown) that performs mold clamping and mold opening of the movable mold section 52 with respect to the 50 fixed mold sections 51.

The fixed mold part 51 of the mold mechanism 50 has a fixed platen 10 arranged at the upper part of FIG. 1, and a fitting hole 11 penetrating vertically in FIG. Is formed. A sprue bush 12 is fitted in the fitting hole 11, and the lower part of FIG. 1 of the sprue bush 12 protrudes below the lower surface of the fixed platen 10 in FIG. Inside the sprue bush 12, resin passages R1 are formed at the top and bottom in FIG. 1, and at the lower end of the resin passage R1, a disk gate G extending in the radial direction is formed. In the upper part of the sprue bush 12 in FIG.
Is provided so as to communicate with the upper end of the resin passage R1 in FIG.

The sprue bush 12 has a belt-like cooling water flow passage R2 surrounding the lower portion of the resin passage R1 in FIG.
A cooling water supply path R3 for supplying cooling water of about 30 to 80 degrees Celsius to the cooling water flow path R2, and a cooling water discharge path R4 for discharging cooling water from the cooling water flow path R3. Distribution means are provided.

On the lower surface of the fixed platen 10 in FIG. 1, a substantially donut disk-shaped fixed mold 20 is attached by inserting and fitting the sprue bush 12, and the fixed mold 20 is fitted to the sprue bush 12. The joint portion is formed of a fitting sleeve 21. The fitting sleeve 21 has a heat insulating sleeve 21a forming the inner peripheral surface thereof.
Is made of a material having high heat resistance and heat insulating effect, such as Vespel manufactured by DuPont, which is mainly formed by molding a polyimide resin.

The lower surface of FIG. 1 of the fixed mold 20 is a cavity C1 forming a donut disk-shaped optical disk 1A.
An upper surface and an inner peripheral surface are formed, and a large number of cooling water flow passages R6 as cooling water supply means for a resin molded plate are provided along the cavity C1 in the upper portion of FIG. Cooling water of about 100 degrees Celsius to about 120 degrees Celsius flows through the cooling water flow passage R6.

An annular fitting protrusion 22 protruding downward in FIG. 1 is formed on the periphery of the fixed mold 20. The outer peripheral surface 22a of the fitting protrusion 22 is tapered downward in FIG. are doing.

The movable mold part 52 of the mold mechanism 50 has a movable plate 30 arranged at the lower part of FIG. 1, and the movable plate 30 has a substantially cylindrical housing 31 with an opening 31a in FIG. It is provided facing upward. The inner peripheral surface of the opening 31a has a movable mold fitting surface 31b, a fixed mold fitting surface 31c whose diameter is further increased at the upper end side in FIG. 1, a movable mold fitting surface 31b, and a fixed mold. Step surface 31 connecting between fitting surface 31c
d. The fixed mold fitting surface 31c is formed so as to expand toward the upper side in FIG.
1c has an outer peripheral surface 22a of the fitting projection 22 of the fixed mold 20.
However, the fixed die 20 is fitted so as to be centered by the taper. The end surface 22 b of the fitting projection 22 of the fixed mold 20 is projected downward from the step surface 31 d of the housing 31.

The lower end of FIG. 1 of the outer peripheral surface 41 of the movable mold 40 having a donut disk shape is provided on the movable mold fitting surface 31b of the open end 31a of the housing 31 with the housing 31 and the movable platen 3.
1 is fitted so as to be slightly movable vertically in FIG. The outer peripheral surface 41 of the movable mold 40, the fixed mold fitting surface 31 b of the housing 31, and the step surface 31 d form the fitting recess 5.
2a is formed.

The upper surface of the movable mold 40 forms the lower surface of the cavity C1 forming the donut disk-shaped optical disk 1A. A stamper (not shown) for transferring information is mounted on the upper surface of the movable mold 40. I have. In the lower part of FIG. 1 of the movable mold 40, a number of cooling water flow paths R7 as cooling water supply means for the resin molded plate are provided along the cavity C1. Cooling water of about 100 degrees Celsius to about 120 degrees Celsius flows through the cooling water flow passage R7.

The inner periphery of the movable mold 40 is provided with a cavity C1.
The ejector 42 includes a cylindrical ejector 42 for projecting the optical disc 1A. The ejector 42 has a gate cut that is driven toward the inside of the fitting sleeve 21 of the fixed mold 20 and pushes and cuts the disc gate G. 43
Is built-in.

Since the injection compression molding apparatus 100 has the above configuration, first, the injection nozzle 61 of the injection mechanism 60
After the resin is injected and filled into the cavity C1 through the resin passage R1 and the disk gate G, the movable mold 40 is minutely moved to the fixed mold 20 side, and the filled resin is forcibly pressed to cure. In this case, it is possible to prevent sinking of the resin at the time and to make the density distribution uniform. Thereby, the distortion of the optical disk 1A can be reduced, the transferability from the stamper can be improved, and the optical characteristics including birefringence can be improved. That is, the optical disc 1A with high precision and high precision can be formed.

Next, the optical disk 1A in the cavity C1
During the curing process of the sprue 7A of the resin passage R1, the cooling water flow passage R2 provided around the sprue 7A
Cooling water of about 30 ° C. to about 80 ° C. is flowed through the sprue 7A, which is higher in temperature and thicker than the optical disc 1A in the cavity C1, especially at the root portion, immediately after the resin is injected and compressed. Cooling water of about 100 degrees Celsius to about 120 degrees Celsius flows through cooling water flow paths R6 and R7 provided in the mold 20 and the movable mold 40, and the optical disc 1A in the cavity C1 is heated at a higher temperature than the sprue 7A. Cooling. At this time, since the heat insulating sleeve 21a is provided on the inner peripheral surface of the fitting sleeve 21 fitted to the sprue bush 12 in which the sprue 7A is formed, the low-temperature cooling water flowing through the cooling water flow passage R2 allows the inside of the cavity C1 to be cooled. Rapid cooling of the inner circumference of the optical disc 1A is prevented.

Therefore, the optical disk 1 in the cavity C1
As compared with A, the cooling of the sprue 7A, which is higher in temperature and thicker than the optical disc 1A, that is, the progress of curing can be accelerated, so that the difference in the degree of curing progress between the optical disc 1A and the sprue 7A can be reduced. . Thus, even if the optical disk 1A is cooled more rapidly than in the past, the internal distortion can be kept low, and rapid hardening becomes possible. Therefore, it is possible to further increase the cycle of manufacturing the optical disc 1A.

In the above embodiment, as the heat insulating means , the heat insulating sleeve 21a is mainly made of, for example, a polyimide resin.
Of DuPont Vespel etc.
Made of high heat and heat insulating material, but with sleeve
It is good also as a structure which provides an air layer of a shape .

In the above embodiment, the injection compression molding apparatus 100 for producing the optical disk 1A has been described. However, the injection compression molding apparatus for producing other magneto-optical disks, plastic lenses and the like may be used. Of course.

[0025]

According to the injection compression molding apparatus of the first aspect, it is possible to reduce the difference in the degree of curing progress between the resin molded plate and the sprue, and the resin molded plate can be uniformly cooled over the entire surface. Further, even when cooling is performed more rapidly than in the conventional case, it is possible to prevent internal distortion of the resin molded plate. Therefore, it is possible to further increase the cycle of manufacturing the resin molded plate.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an injection compression molding apparatus according to the present invention.

FIG. 2 is a view showing an example of a conventional injection compression molding apparatus.

FIG. 3 is a diagram showing a temperature distribution of a resin molded plate and a sprue during curing.

[Explanation of symbols]

1A ... Optical disk (resin molded plate) 7A ... Sprue 20 ... Fixed die (die) 21a ... Heat insulation sleeve (heat insulation means) 40 ... Movable die (die) 60 ... Injection mechanism (injection means) C1 ... Cavity R1 ... Resin passage R2: cooling water flow passage (cooling water distribution means, cooling water distribution means for sprue) R3: cooling water supply path (cooling water distribution means, cooling water distribution means for sprue) R4: cooling water discharge path (cooling water distribution means) R6: Cooling water flow path (cooling water flow means, cooling water flow means for resin molding plate) R7: Cooling water flow path (cooling water flow means, cooling water flow means for resin forming plate)

Claims (1)

(57) [Claims] 1. A mold for forming a cavity for a resin molded plate, an injection means for injecting a resin into the cavity via a resin passage, and a resin molded plate formed in the cavity or formed in the resin passage. A cooling water flowing means for cooling the sprue, wherein the cooling water flowing means is a resin-molded plate cooling water flowing means for cooling the resin molded plate, and a belt-like shape surrounding the sprue. The sprue cooling water circulation means is formed to cool the sprue, the sprue cooling water circulation means, the cooling water of the resin molding plate cooling water circulation means lower temperature of the cooling water flow, Around the sprue cooling water flow means, the sprue
An injection compression molding apparatus , wherein a heat insulating sleeve is provided as a heat insulating means for insulating between a cooling water flowing means for use and the resin molding plate.