JPS63160815A - Injection compression molding method and mold therefor - Google Patents

Abstract

PURPOSE:To improve facial accuracy of both faces of a molded product, by a method wherein resin with which the inside of a cavity is filled is compressed by a predetermined quantity through a stationary side insert and a movable side insert constituted movably and relatively with each other. CONSTITUTION:A stationary side mold part 2 and movable mold part 3 are joined each other by fixing them through joining and mold registration at a parting line 4, and the inside of a cavity 14 is filled with molten resin through injection through a sprue 17, runner 18 and gate 19, in injection molding of high-precision optical parts such as plastic lens. Then when ejector plates 10, 11 are moved upward by a predetermined quantity, a movable side insert is shifted in a contracting direction of inner capacity of the cavity 14 through an ejection rod 24 by being pressed by the predetermined quantity. At the same time, a stationary insert 12 also is shifted in the contracting direction of the inner capacity of the cavity through a pressing lever operation rod 23 and pressing lever 22 of the stationary side insert. Then compression molding of the resin in the cavity 14 is performed into a molded product of a predetermined form through pressing operation of each of the inserts 12, 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Yf] The present invention relates to an injection compression molding method for injection compression molding molded products such as plastic lenses, and a mold for the same.

[Prior Art] When injection molding high-precision optical parts such as plastic lenses, it is required to mold the molded product so that no optical distortion occurs, and injection compression molding is often used as a step to satisfy this requirement. It is used.

L: This type of injection molding apparatus includes 1, for example, JP-A-58
A technique disclosed in Japanese Patent No.-167134 is known. This technology is configured so that the molten resin in the cavity can be shaped into a pressure of 1M1J by moving the movable metal part 5 with respect to the mold part of the fixed die plate via a hydraulic mechanism. , and many injection compression molding machines employ this one-stage process.

[Problems to be Solved by the Invention] In the configuration of the prior art described in L, the compression operation is performed by moving the movable mold part with respect to the fixed mold part. There was a problem.

In other words, since the molten resin injected into the cavity is a viscoelastic body, if it is pressed by the movable mold part, it will also act on the fixed mold part, but it will not cause interference fringes such as plastic lenses. There has been a problem in that good transferability cannot be obtained when molding a molded article that requires mold transferability. The reason for this is that the skin layer on the surface of the resin filled in the cavity, especially the skin layer on the resin surface on the fixed mold part side, solidifies in a short time, and as a result, i'i
There was a drawback that good transferability could not be obtained on the fixed mold part side compared to the seven moving mold part side.

Furthermore, in some cases, the molding surface on the fixed mold part side is required to have better surface accuracy than the molding surface on the movable mold part side, and the above-mentioned conventional technology does not satisfy such requirements. It was not possible to form a molded product.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and is designed to enable transfer with better surface precision to the same level on the resin surfaces (molding surfaces) on the fixed mold part side and the movable mold part side. The object of the present invention is to provide an injection compression molding method and a mold for the same.

[Means for Solving the Problems] The method of the present invention includes injecting and filling a molten resin into a cavity, and making the resin filled in the cavity movable relative to each other. It is compressed by a predetermined amount via the fixed bias f and the movable insert. In addition, the injection pressure knitting/forming mold of the present invention has a fixed member T~ that forms the molding surface 41 forming the cavity tee, and a movable side insert that is movably operated in the direction of expanding or contracting the internal volume of the cavity. The molten resin injected and filled into the cavity can be fixed and compressed through the 1/4 constant side insert and the movable side insert and molded.

[Operation 1] In the injection compression molding mold having the above configuration, molding can be performed while compressing the molten resin filled in the cavity by the fixed side and movable side inserts that are both movably operated.

[Example] Hereinafter, an example of the present invention will be described in detail using the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of an injection compression molding mold 1 according to the present invention, with main parts shown in cross section.

As shown in the figure, a first embodiment of a mold l for injection compression molding is shown, and the main parts are shown in cross section.

As shown in the figure, the injection mold l has a 4W structure consisting of a fixed side mold part 2 and a movable side mold part 3, and both molds i'l1
2 and 3 are constructed so that they can be moved toward and away from each other at a parting line (mold matching surface) 4.

Fixed side mold! 9B2 has a fixed side mounting plate 5 and a fixed side mold plate 6, and a movable side mold part 2 has a movable side mounting plate 7. Receiving plate 8. Movable side template 9. and two ejector plates 10 and 11.

The fixed side mold plate 6 includes a fixed side insert 1 having a molding surface 12a.
2 is installed inside, and this fixed side insert 12 is attached to the fixed side mold plate 6.
The cavity 14 is movably guided by a guide cylinder 13 fitted therein in directions to expand and contract the volume of the cavity 14. The movable side mold plate 9 is equipped with a movable side insert 15 having a molding surface 15a.
It is movably guided in the direction of expanding or contracting the volume of. Inside the cavity 14 formed between the molding surfaces 12a, 15a of each insert 12.15 is a sprue 17. Runner 18. The molten resin is injected and filled through the gate 19.

Is there a recess in the joint surface of the fixed side mounting plate 5 with the fixed side mold plate 6? B20 is formed, and this four part 20 is equipped with a fixed side nesting suppression lever 22 which is swingably supported via a support pin 21. The tip end (left end in the figure) of the stationary insert press lever 22 is engaged with the upper surface of the stationary insert 12, and the rear end is connected to the press lever operating rod 23 connected to the ejector plate 10° 11. It is connected to the upper end of the. That is, the fixed side insert 12 is connected to the ejector plates 10, 11 . Fixed-side nested press lever 2 that is swing-operated counterclockwise via a press lever operating rod 23
2, the direction in which the volume inside the cavity 14 is reduced;
That is, it is set to perform a suppressing movement operation in the direction of compressing the molten resin filled in the cavity 14.

The pressing force that presses the fixed side insert 12 is the support pin (fulcrum)
It is set so that it can be variably adjusted by changing the distance L1 from 21 to the engaging part 22a and the distance ft L2 from the engaging part 22b.

The movable side insert 15 is connected to an ejector rod 24 connected to the ejector plate 10, 11, and the movable side insert 15 is connected to the ejector plate 10, 11. It is set to be operated to expand or contract the volume inside the cavity 14 via the ejecting rod 24. Reference numeral 25 indicates a rod for pushing up the molded product.

Next, a method for injection compression molding a plastic lens using the mold l having the above configuration will be described.

First, the fixed side mold 8112 and the movable mold part 3 are joined at the parting line 4, and the molds are matched and fixed.

Next, sprue the molten resin 17. Runner 18° game) 1
The liquid is injected and filled into the cavity 14 through step 9.

Next, the ejector plates 10 and 11 are moved up by a predetermined amount via an operation mechanism (not shown). Due to this L movement of the ejector plate 10.11, the movable side insert 15 is moved to a predetermined position 4 in the direction of reducing the internal volume of the cavity 14 via the ejector rod 24, and at the same time, the fixed side insert 12 is also moved to the pressing lever. Operation rod 23. In this embodiment, the lens effective diameter of the molded product is set to 17.51 mm on the movable side insert 12 side, and the molded product is suppressed by a predetermined amount in the direction of reducing the cavity internal volume via the fixed side insert suppressing lever 22.
Set the fixed side insert 15 side to 11.98 mm, and each insert 1
The pressing force of 2.15 is 900 for the movable insert 12 side.
kgf, and the fixed side insert 15 side was set to 419 kgf. Also, LI:L2 was set to 7:3.

Due to the suppressing action of each of the inserts 12 and 15, the resin within the cavity 14 is compression-molded into a plastic lens (molded product) having a predetermined shape.

When the molding is completed and the molded product is cooled, the mold is opened, and the molded product is pushed up via the push-up rod 25 or the like and taken out.

Injection compression molding is completed as described above, but in this embodiment, the resin in the cavity 14 is compressed by both the fixed side and movable side inserts 12.15, which are configured to be relatively movable. The skin layer on the resin surface on the fixed side insert 12 side does not solidify within a short time as well as on the movable biasing element 15 side, and therefore the resin is removed from both the fixed side and movable side inserts 12゜15. In contrast, it is possible to obtain reversibility of the fringe level. As a result, both the fixed side and movable side inserts 12.1
The surface accuracy of the molded product on the 5th side can be improved.

(Second Embodiment) FIG. 2 shows a second embodiment of the unexploded 11. The feature of this embodiment is that the fixed side nesting suppression lever 22 in FIG. This is because the suppression operation unit 30 is used. The suppression operation section 30 closes the incompressible fluid 32 filled in the fluid passage 31 formed in the fixed side mounting plate 5 and the entrance/exit of the fluid passage 31, and also closes the movable side insert 12 and the suppression operation lever (the main body). In this embodiment, since the stationary insert pressing lever 22 shown in FIG. 1 is not used, the member indicated by the reference numeral 23 in FIG. 1 will be referred to as a pressing operation lever). It is composed of The lid members 33, 34 are formed to have a suitably large diameter so that they can move within the passages 31a, 31b within a predetermined distance. Since the other configurations are the same as in FIG. 1, the same members are given the same reference numerals and their explanations will be omitted.

In the above structure as well, injection compression molding can be performed in the same molding process as in the first embodiment, and the same functions and effects as in the first embodiment can be achieved.

(:jS3 Embodiment) FIG. 3 shows a third embodiment of the present invention. The feature of this embodiment is that the mechanism for pressing the stationary side insert 12 is composed of a pressing rod 40 and a cam 41. This is the point that was constructed. The suppression rod 40 has a guide hole 42 formed in the fixed side plate mounting plate 5.
The rod push pin (referred to as rod push pin in this embodiment) is configured to be slidable in the left and right direction, and has a tapered surface 40a that is formed with the tapered surface 23a at the upper end of the rod push pin (referred to as rod push pin in this embodiment). The cam 41 is rotatably supported via a support shaft 43, and is set so that it can press the stationary insert 12 by rotating the cam 41 counterclockwise via the press rod 40. It is.

Even in the L configuration, injection compression molding can be performed in the same molding-L process as in the first embodiment, and the same operations and effects as in the first embodiment can be achieved.

(Fourth Embodiment) FIG. 4 shows a fourth embodiment of the present invention. The feature of this embodiment is that the fixed side The point is that the insert 12 is configured so that it can be operated by pressing. The hydraulic cylinder 51 is fixed to the side surface of the fixed side mounting plate 5 via a mounting plate 53, and has a tapered surface 52a formed at the tip of the piston rod 52 and a tapered surface 12a formed on the fixed side insert 12. It is connected with.

According to the configuration L, the fixed side insert 12 and the movable side insert 15 (
(not shown).

The fixed side insert 12 can be separated from the movable side insert 15 and suppressed, and the pressing force can be controlled by the controller 50.
It has the advantage of being able to be set to α via . Further, it is also advantageous to control the pressure of both persons' f12°15 at the same time via the controller 50, because the pressure can be controlled at different timings.

The other configurations, molding steps, and effects are the same as those in the first embodiment, so their explanations will be omitted.

[Effects of the Invention] As described above, according to the present invention, reversibility at the level of interference fringes can be obtained on both the fixed insert side and the movable insert side, and the surface precision of both sides of the molded product can be significantly improved. can. or,
It is also suitable for molding lenses that require surface precision on the fixed insert side.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway explanatory diagram showing a first embodiment of a mold according to the present invention, and FIG. 2 is an explanatory diagram showing a second embodiment of a mold according to the present invention. FIG. 3 is an explanatory cross-sectional view showing a third embodiment of the mold according to the present invention. FIG. 4 is an explanatory diagram showing a fourth embodiment of the mold according to the present invention. 12...Fixed side insert 14...Gearbity 15...Movable side insert 22...Fixed side insert press lever 23...Press lever operating rod 24...Extrusion rod Patent applicant Olympus Optical Attorney for Kogyo Co., Ltd. Takeshi Nara Patent Attorney Amendment to Figure 1 Figure 2 Procedural Amendment (Voluntary) Commissioner of the Japan Patent Office Akio Kuroda 11? (+April 3B1, 1162, Indication of inertia +V (Japanese Patent Application No. 309747, 2013), Name of the invention: Injection compression molding method and its molding die 3, Person making the amendment/Relationship with the case: Patent applicant Address 2-43-2 Hatagaya, Shibuya-ku, Tokyo Name (037) Olympus Optical Industry Co., Ltd. Representative Shimoyamashikibe 4 Column 7 of “Detailed description of the invention” in the agent’s specification Contents of the amendment (1) As described from line 11 to line 14 on page 9 of the specification, ``The skin layer on the resin surface of the fixed side insert 12 also solidifies within a short period of time in the same way as the movable side insert 15 side. 8. List of attached documents

Claims (2)

[Claims] (1) Inject and fill the molten resin into the cavity, and move the resin filled into the cavity through a fixed side insert and a movable side insert that are configured to be movable relative to each other. An injection compression molding method characterized by compressing only a fixed amount. (2) A fixed side insert and a movable side insert each having a molding surface that forms a cavity are provided so as to be movable in the direction of expanding or contracting the internal volume of the cavity, and the melt is injected and filled into the cavity. A mold for injection compression molding, characterized in that the mold is configured to be able to mold a resin while compressing a predetermined amount of resin through the fixed side insert and the movable side insert.