JPH06293047A - Mold - Google Patents

Abstract

PURPOSE:To finely adjust the interval of a cavity left and right and up and down and minimize the irregularity of optical characteristics caused by thickness by providing an adjusting mechanism capable of finely adjusting the depth of the cavity to the force-cutting surface of one of a fixed mold and a movable mold. CONSTITUTION:A fixed mold 1A and a movable mold 1B are clamped by a clamping device to form four cavities 40A, 40B by four pairs of female molds 7 and male molds 16. The cavities 40A are formed by a pair of the female and male molds 7, 16 and the depth of the cavities 40A, 40B, etc., can be finely adjusted by spacers 30A, etc. The depths of the cavities 40A in a standard adjusting state are adjusted by holding the spacer 30A with a thickness Ta between the cavities 40A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to the case of molding a molded product such as a substrate for an optical disc (hereinafter simply referred to as "disc") such as a compact disc (CD) or a mini disc (MD). The present invention relates to a molding die used.

[0002]

2. Description of the Related Art In the following description, a disk will be described as an example of a molded product. Usually, the disc is molded by an injection compression molding method using a molding die composed of a fixed side die and a movable side die. The disc has a thickness of, for example, an MD disc that is formed so as to be within a range of 1.2 mm ± 0.1 mm. However, even if the disc is within the standard, if the disc has a minute thickness unevenness within that range, the homogeneity of the resin is impaired during molding, and the optical birefringence characteristics of the disc, etc. The optical characteristics will not be within the specifications.

Therefore, in molding a disk, in order to keep optical characteristics such as birefringence of light within the standard, the gap between the cavities formed by the fixed mold and the movable mold is reduced. However, it is necessary to make the disc thickness uniform. Particularly, in the injection compression molding method of molding a plurality of disks with one molding die, it is necessary to minimize this nonuniformity.

[0004]

Therefore, in the conventional injection compression molding, both the fixed side mold and the movable side mold are mechanically machined with high precision, and the clamping of them is performed vertically and horizontally. It is assembled with high precision so that there is no sway, and the molding conditions are strictly controlled.

However, even if these controls are performed, the molding method of slightly opening the mold by injection pressure is adopted in the molding of the disk, and the parallelism of the platen of the molding machine is up to about 0.03. Since it can only be adjusted, there is a limit naturally even if individual accuracy of thickness variation factors is pursued. It is an object of the present invention to obtain a disk having a uniform thickness that greatly affects the birefringence characteristics of light.

[0006]

Therefore, according to the present invention,
It is considered that the space between the cavities formed by the molding die composed of the fixed-side die and the movable-side die during forming has unevenness from the beginning, and at least one of these die push-cut surfaces. In addition, an adjustment mechanism for finely adjusting the depth of the cavity is provided, and a molding die composed of a fixed side mold and a movable side mold in which a plurality of cavities capable of simultaneously molding a plurality of molded products are formed. In the mold, an adjusting mechanism capable of finely adjusting the depth of each cavity is provided on the push-cut surface of at least one of the molds around each of the cavities to solve the above problems.

[0007]

Therefore, in the molding die of the present invention, the distance between the cavities can be finely adjusted on the left, right, upper and lower sides, and the variation in optical characteristics due to the thickness can be minimized.

[0008]

EXAMPLES Next, a molding die of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a molding die of the present invention, and FIG. 2 is a plan view seen from a cavity surface of a fixed-side die of the molding die of the present invention, for example, in which four MDs can be simultaneously molded. FIG. 3 shows one cavity of four MDs of the fixed side mold shown in FIG. 1 taken out and enlarged, and FIG. 3A is a plan view seen from the cavity surface. FIG. 4B is a cross-sectional view taken along the line AA in FIG. 4A, and FIG. 4 shows one molding die of the present invention when the cavities have standard intervals, and FIG. FIG. 4B is a cross-sectional view showing the side die and the movable die separated from each other by a push-cut surface, and FIG. B shows a state in which the fixed die and the movable die are fastened to form a cavity. FIG. 5 is a cross-sectional view, and FIG. 5 shows one molding die of the present invention when the spacing between cavities is adjusted. FIG. 4 is a cross-sectional view showing a state in which the fixed-side mold and the movable-side mold are separated by a pressing surface, and FIG. B shows a state in which the fixed-side mold and the movable-side mold are fastened to form a cavity. It is the sectional view shown.

First, a molding die of the present invention capable of molding four MDs at a time will be described with reference to FIGS. 1 and 2. In FIG. 1, reference numeral 1 generally indicates the molding die of the present invention. The molding die 1 is composed of a fixed side die 1A and a movable side die 1B.

The fixed side mold 1A includes a mounting plate 2, a manifold plate 3, a mold plate 4, and four circular inserts 5A, 5B, 5C and 5D which are fitted to the mold plate 4, and these. It is composed of a female die 7 (FIGS. 1 and 2) composed of circular rings 6A, 6B, 6C and 6D fitted between the two, a manifold 8 and the like.

A resin injection device 9 is provided at the center of the mounting plate 2, and the manifold 8 has manifold channels 8A and 8B branched from a common resin injection port facing the resin injection device 9. , 8C and 8D (8C and 8D are not shown, but in a position opposite to 8A and 8B) are formed, and the manifold 8 is formed by the mounting plate 2 and the female mold 7. The space is provided in the manifold plate 3.

The female die 7 is fixed to the mounting plate 2 via the manifold plate 3, and the female die 7 has the manifold flow paths 8A, 8B,
Resin injection pipes 9A, 9B, 9C and 9D (9C and 9D are not shown) connected to the respective outlet sides of 8C and 8D are provided, and their gate portions 10 are provided.
A, 10B, 10C and 10D (FIGS. 1 and 2) are opened at the centers of the respective nests 5A, 5B, 5C and 5D.

In FIG. 3, of the four female molds, only the female mold 7 consisting of a part of the mold plate 4, the insert 5A and the circular ring 6A is taken out and further enlarged and shown. A of the same figure shows the cavity surface, and B of the same figure shows a cross-sectional view taken along the line AA of FIG.

An annular step portion 20 having an annular inner peripheral surface 21 having an L-shaped cross section and an annular flat surface 22 is formed on the inner surface of the die plate 4 on the push cut surface (parting line) Ka side. On the other hand, on the outer periphery of the cavity 5A on the cavity surface Ha side, an annular flat surface which is also L-shaped in cross section and which forms the same plane as the annular outer peripheral surface 24 parallel to the annular inner peripheral surface 21 and the annular flat surface 22. An annular step portion 23 composed of 25 and 25 is formed.

A circular ring 6A having an L-shaped cross section is fitted in the annular groove formed by the annular step portion 20 and the annular step portion 23. One end surface of the circular ring 6A and the template 4 are fitted. The push-cut surface Ka forms the same plane, and the inner peripheral surface of the circular ring 6A and the smooth surface of the insert 5A (that is, the cavity surface Ha) form a cavity 40Aa on the female mold 7 side. ing.

Furthermore, the annular inner peripheral surface 21 of the stepped portion 20.
An annular spacer 30A for finely adjusting the depth D of the cavity is fitted in, for example, four positions of the annular groove formed by the annular outer peripheral surface of the circular ring 6A, and
In A, the circular ring 6A is fixed to the mold plate 4 by a screw 26 at the center of the upper and lower spacers 30A, and on both sides of the screw 26 and at the left and right spacers 30A of the female mold 7, The spacer 30A is attached to the circular ring 6A by screws 27 at both ends thereof.
It is fixed to.

Next, the movable mold 1B will be described. The movable side mold 1B was fitted between a mounting plate 11, a spacer block 12, a mold plate 13 and circular inserts 14A, 14B, 14C and 14D fitted to the mold plate 13 and between them. Outer circular ring 15A, 15B, 15
Male 16 composed of C and 15D (Figs. 1 and 2)
And an ejector device 17 and the like.

The male mold 16 has its respective nests 14A, 14A.
B, 14C and 14D are the nests 5A, 5 of the female die 7, respectively.
It is fixed to the mounting plate 11 via the spacer block 12 so as to face B, 5C, and 5D, respectively.

The ejector device 17 is located in the space 12A of the spacer block 12 and includes a main ejector plate 17A and a sub ejector plate 1
7B and five ejector pins 17 supported by 7B
It consists of Ca, 17Cb, 17Cc and 17Cd (17Cc and 17Cd are not shown) and an ejector rod 17D that pushes the main ejector plate 17A. The ejector rod 17D is pushed to the right by a hydraulic device (not shown). By doing so, the main and sub ejector plates 17A and 17B move to the right of the arrow R, and accordingly, the ejector pins 17Ca, 17Cb, 17
The four CMDs and the 17Cd tip portions are configured to be able to simultaneously press the four MDs that have been formed and release them.

In FIG. 4A, of the four male molds, only the male mold 16 including a part of the mold plate 13, the insert 14A and the outer peripheral circular ring 15A is taken out and enlarged and shown. This nest 14
The outer peripheral surface of A on the cavity surface Hb side has an L-shaped cross section,
An annular step portion 50 composed of an annular flat surface 51 and an annular outer peripheral surface 52 is formed, and the outer peripheral circular ring 15A includes
The push-cut surface (parting line) Kb of the male die 16 that abuts the outer peripheral surface of the cavity surface Ha of the insert 5A and the push-cut surface Ka of the circular ring 6A are fitted and have an abutment surface 53 that can abut. An annular step portion 54 having an L-shaped cross section is formed. With the inner peripheral surface of the outer peripheral circular ring 15A and the cavity surface Hb, the cavity 40 of the male mold 16 is formed.
Ab is formed.

Although not shown, the outer peripheral circular ring 15A has cavity surfaces Ha, H by hydraulic means or the like.
The annular step portion 5 is movable in a direction (arrow R) perpendicular to b.
It is set to 0.

By fastening the fixed-side die 1A and the movable-side die 1B having such a structure by a fastening device (not shown), four pairs of the female die 7 and the male die 16 form four pieces. Cavities 40A, 40B, 40C and 40D (40C and 4
0D is not formed). In FIG. 4B,
A state in which the cavity 40A is formed by the pair of female mold 7 and male mold 16 is shown. These cavities 40A, 40
The depth Da of B, 40C and 40D is set to the spacer 30.
The point that the fine adjustment can be performed by A, 30B, 30C and 30D (30C and 30D are not shown) is the main point of the present invention.

Next, the fine adjustment mechanism will be described with reference to FIGS. 4 and 5. FIG. 4B shows that the depth Da of the cavity 40A is adjusted to a standard adjustment state where the push-cut surface Ka of the female die 7 that is the fixed-side die and the push-cut surface Kb of the male die 16 that is the movable-side die abut against each other. It is sectional drawing which showed the state at the time.
The depth Da of the cavity 40A in the standard adjustment state was adjusted by sandwiching the spacer 30A having a thickness Ta.

In this case, the surface of the spacer 30A forms the same plane as the push-cut surface Ka of the mold plate 4 and the circular ring 6A, and when both are fastened (FIG. B), the same as the push-cut surface Ka of the female die 7. The push-cut surface Kb of the male mold 16 collides with each other,
Then, the push-cut surface Ka of the circular ring 6A abuts the abutment surface 53 of the outer peripheral circular ring 15A, and the cavity surface Ha of the insert 5A and the push-cut surface Kb of the outer peripheral circular ring 15A abut. ing.

FIG. 5 shows a spacer 30 having a slightly thicker thickness Tb.
It shows that the cavity 40A having the depth Db is adjusted by sandwiching A. FIG. A is a sectional view showing a state in which the female die 7 and the male die 16 are opened.
The surface of A projects from the push cut surface Ka of the template 4.

Therefore, when the male die 16 and the female die 7 fitted with the thick spacer 30A are fastened, the surface of the spacer 30A is the template plate 13 of the male die 16 as shown in FIG. Abutting against the push-cut surface Kb of the circular ring 6
Push-cut surface Ka of A and abutting surface 5 of outer circular ring 15A
3, and the cavity surface Ha of the female die 7 and the push cut surface Ka of the outer peripheral circular ring 15A abut, but the push cut surface Ka of the mold plate 4 and the push cut surface Kb of the mold plate 13 do not abut. There is a slight gap. Therefore, by mounting the slightly thicker spacer 30A, a cavity 40A slightly deeper than the depth Da shown in FIG. 4B can be realized.

These spacers 30A, 30B, 30C
And 30D, the movable side mold 1B is retracted to an open state as shown in FIG. 4A or FIG. 5A, first, the screw 27 is removed, and the already mounted spacer is removed. Insert a spacer of the desired thickness into
It can be replaced and mounted by fixing it again with the screw 27.

As the spacers, for example, spacers having various thicknesses are prepared in advance so that the thickness can be adjusted to a range of 0.2 mm at intervals of 5 μm. Then, each cavity can be finely adjusted.

If the fine adjustment as described above is carried out for each of the cavities 40A, 40B, 40C and 40D, the depth Da (Db etc.) of each cavity can be changed, and the disc with no variation in thickness ( MD) can be obtained.

In the above description, a molding die having four cavities has been described, but one or two cavities,
Alternatively, the adjusting mechanism of the present invention can be applied to many molding dies. Further, by adjusting the thickness of each of the upper, lower, left, and right spacers mounted around each cavity, the depth of the cavity in the upper, lower, left, and right directions can be adjusted.

[0031]

As is apparent from the above description, according to the present invention, there are variations in the thickness of the cavity from the beginning due to various factors such as the precision of the injection molding machine, the precision of the mold, and the molding conditions. Therefore, it is possible to finely adjust the space between cavities on the left, right, top and bottom of the molding die to make the thickness of the disc (molded product) due to the depth uniform, and to obtain the optical characteristics due to the thickness of the disc found in the prior art. Variations can be suppressed. Therefore, in processing and assembling the molding die, if the precision of the die alone is taken out, adverse effects due to other factors can be obtained by the fine adjustment, and various excellent effects can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a molding die of the present invention.

FIG. 2 is a plan view seen from the cavity surface of the fixed side mold of the molding mold of the present invention in which, for example, four disks can be molded simultaneously.

FIG. 3 is an enlarged view of one of the four cavities of the fixed side mold shown in FIG. 1 taken out, and FIG. 3A is a plan view seen from the cavity surface. FIG. B is a sectional view taken along the line AA of FIG.

FIG. 4 shows one molding die of the present invention when the cavities have a standard interval, and FIG. 4A shows a state in which the fixed-side die and the movable-side die are separated by a push-cut surface. It is the sectional view shown, and the same figure B is the sectional view showing the state where the fixed side mold and the movable side mold are fastened together to form a cavity.

FIG. 5 shows one molding die of the present invention when the space between cavities is adjusted, and FIG. 5A shows a state in which the fixed side die and the movable side die are separated by a push-cut surface. It is the sectional view shown, and the same figure B is the sectional view showing the state where the fixed side mold and the movable side mold are fastened together to form a cavity.

[Explanation of symbols]

 1 Molding Mold 1A Fixed Side Mold 1B Movable Side Mold 4 Template 5A Insert 5B Insert 5C Insert 5D Insert 6A Circular Ring 6B Circular Ring 6C Circular Ring 6D Circular Ring 7 Female 13 Mold Plate 14A Insert 14B insert 14C insert 14D insert 15A outer peripheral circular ring 15B outer peripheral circular ring 15C outer peripheral circular ring 15D outer peripheral circular ring 16 male 20 annular step 21 annular inner peripheral surface 22 annular flat surface 23 annular step 24 annular outer peripheral surface 25 annular Plane 30A Spacer 30B Spacer 30C Spacer 30D Spacer 40A Cavity 40B Cavity 40C Cavity 40D Cavity 40Aa Female Mold 7 Side Cavity 40Ab Male Mold 16 Side Cavity 50 Annular Step 51 Annular Flat 52 Annular Peripheral Surface 53 Abutting Surface 54 Annular Step Ha cavity surface H Cavity surface Ka press cutting surface Kb push cutter surface Da thickness Tb thickness of the spacer standard adjustment state at depth Db adjusting the cavity depth Ta spacer cavity

Claims (2)

[Claims] 1. An adjusting mechanism for finely adjusting a depth of a cavity is provided on a push-cut surface of at least one mold of a molding mold composed of a stationary mold and a movable mold. Mold to be used. 2. A molding die comprising a fixed-side die and a movable-side die forming a plurality of cavities capable of simultaneously forming a plurality of molded articles, and at least one of the periphery of each cavity. The molding die is characterized in that an adjusting mechanism for finely adjusting the depth of each cavity is provided on the push-cut surface of the die.