JPH02295618A - Die guide device for die for forming disklike parts - Google Patents

Abstract

PURPOSE:To manufacture a die guide device for die with high accuracy and inexpensively by providing a guidepost on an approximately equidistant and equally divided angular position from the center of die assemblies and so as to slide in a radial direction. CONSTITUTION:The die guide device for the die with which disk-like parts are formed is constituted by connecting the die assemblies 1, 2 of fixing side and the die assemblies 3, 4 of moving side with the guidepost 7 which is provided on one side and a guide bush 8 which is provided on the other side. Then the guidepost 7 is provided on the approximately equidistant and equally divided angular position from the center of the die assemblies 1, 2 and so as to slide in the radial direction. Thereby, breakage phenomenon of both members by a bending stress and an excessive surface pressure when the guidepost is inserted into the guide bush is dissolved.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is an injection mold for molding a disk-shaped component such as an optical disk substrate, and the present invention is aimed at controlling the heating temperature of the fixed side and movable side molds. The present invention relates to a mold guide device for a mold for molding disc-shaped parts that solves the problems caused by the difference.

(Problems to be solved by conventional technology and invention) CD,
In mold equipment that molds disc-shaped parts such as optical disk substrates such as laser discs, guide posts and bushings installed on other molds may be misaligned with the guide post fixed to the mold. Damage to both the post and guide bushing is a problem.

According to the inventors' study, this is caused by a misalignment of the axis due to the difference in thermal expansion due to the difference in heating temperature between the molds on the fixed side and the movable side, and the guide post is guided and inserted into the guide bush. It was found that excessive bending stress was generated when the

This problem will be explained with reference to FIG. 4, which is a schematic cross-sectional view of a conventional optical disk injection mold.

FIG. 4 is a cross-sectional view for explaining the problems of a conventional mold guide device for a mold for molding a disk-shaped part.

A fixed cavity 2 is fixed to the fixed substrate 1, and a movable cavity 4 is fixed to the movable substrate 3.

A disk-shaped molding cavity 5 is formed between the stationary side cavity 2 and the movable side cavity 4, and a resin material is injected and filled therein, and a stamper plate 6 having an uneven signal portion on one side is disposed on the movable side. There is.

When the molten resin material is injected and filled into the molding cavity 5 from an injection hole (not shown) provided in the center of the stationary cavity, the signal portion of the stamper plate 6 is transferred to the resin molding surface.

Usually, three to four guide posts 7 are firmly and fixedly attached on the circumference of a circle centered on the center of the stationary substrate l.

The guide bush 8 is provided coaxially on the movable base plate 3 in correspondence with each guide post 7 .

The purpose of these members is to accurately align the axes of the molds on the fixed side and the movable side.

In the conventional disk molding mold mentioned above, the stationary side mold is equipped with high-heat parts such as resin injection nozzles and injection holes, and the influence of radiant heat from the resin material heating screw part of the molding machine itself. As a result, the mold temperature tends to be higher than that of the movable mold part.

For this reason, the amount of thermal expansion at the axial center position of the guide post 7 due to the temperature difference is greater than that at the axial center position of the guide bush 8.

Therefore, as shown in FIG. 4, it is inevitable that the molding operation is performed with the axial center position of the guide post 7 shifted by δ.

In this case, the guide post 7 is forcibly bent and inserted into the guide bush 8.

In a standard 130mm diameter disc mold, if the guide post axis position is at a radius of 200mm from the center of the mold, and the temperature is 10°C higher than the movable mold, then approximately +0.024mm outward. It will be displaced to.

In this case, if the length of the guide post 7 from the fixed side board is 90 mm and the diameter is 40 mm, the pressure due to bending stress when the tip is inserted into the end of the guide bush 8 is approximately 2 6 0 kg f or more.

Furthermore, the disk molding device is used in a so-called clean room to prevent dust from adhering to the formed disk.

If lubricating oil is used in the disk molding device, it may scatter and damage the environment and the quality of the product, so lubricating oil cannot be used in the guide bush.

Therefore, if excessive surface pressure is applied to the guide bushing, it may cause breakage of the guide post and the guide bushing, making stable molding operations difficult.

An object of the present invention is to provide a mold for molding disc-shaped parts that can prevent damage to guide posts and guide bushes due to excessive bending stress caused by temperature differences between the base slopes of each mold assembly. The purpose of the present invention is to provide a guidance device.

(Means for Solving the Problems) In order to achieve the above object, the mold guide device for a mold for molding a disk-shaped part according to the present invention has a fixed mold assembly and a movable mold assembly arranged on one side. In a mold guide device for a mold for molding a disc-shaped part, which is connected by a guide post 1 provided on one side and a guide bush provided on the other side, the guide post is placed approximately equidistant from the center of the mold assembly. , are arranged so as to be slidable in the radial direction at equally divided angular positions.

The mold device for molding the disc-shaped part has a concentric circle formed in one of the fixed mold and the movable mold, in which a disc-shaped cavity is provided at the center of the fixed mold assembly and the movable mold assembly, respectively. An optical disc is formed by injecting molten resin at high pressure from the injection hole in the center of the stationary mold into an optical disc molding cavity formed by installing a standby plate with a concave and convex symbol engraved on it and pressing each mold face-to-face on a coaxial center. It can be a forming mold device.

For the guide posts, three or four guide posts are provided in one mold assembly at equidistant positions on a concentric circle from the mold center, and the guide posts are precisely inserted in the axial direction in the other mold. This is a precision positioning guide device for each mold, which is configured by arranging the same number of guide bushes in the same position.
Each guide post can be divided into two parts: a base member that is a mold attachment part, and a tip member that is a guide bush insertion part, and can be connected by a connecting pin.

The engaging part of the two members of the guide post is such that one member has a cylindrical counterbore hole and a through hole perpendicular to the axis, and the other member has a height equivalent to that of the cylindrical counterbore hole and a cylindrical counterbore hole and a through hole at right angles to the axis. When the stepped cylindrical protrusion has an outer diameter smaller than the counterbore hole, and when the cylindrical protrusion is inserted into the counterbore hole, a through-hole with the same diameter and coaxial with the above-mentioned through-hole is provided in the relevant part, and the connecting pin is inserted. The two members are integrated by being inserted into the common through hole, and the member having the cylindrical protrusion can move in parallel in the axial direction of the coupling pin by the gap between the cylindrical counterbore and the cylindrical protrusion. I have to.

(Example) An example of the present invention will be described with reference to the drawings.

FIG. 1 shows a part of the guide post (X in FIG.
-X') A front view and a plan sectional view shown in a broken state.

FIG. 2 is a cross-sectional plan view of a mold device for molding a disc-shaped part.

FIG. 3 is a sectional view showing a state in which the guide post is fitted into the guide bush in the mold clamping state in the mold apparatus.

A guide post base 9 is fixedly attached to the stationary substrate 1 supporting the stationary mold 2 with screws.

A screw hole 10 for a bolt for fixing to the stationary substrate 1 is provided at the end face of the guide post base 9, and the guide post base 9 is fixed at this portion as shown in FIG.

The guide post base 9 is provided with a stepped hole 1) that opens downward and an insertion hole l2 that loosely receives the coupling pin l7.

At the lower end of the movable guide post 13 there is a cylindrical insertion part 14 that is fitted into the guide bush 8, and at the other end there is a guide having the same height as the depth of the stepped hole 1) at the base of the guide post and a diameter smaller than its inner diameter. A stepped cylindrical protrusion 15 of the post movable portion is provided.

The stepped cylindrical protrusion 15 can be fitted with a prescribed gap S, and is provided with a through hole 16 that is coaxial with the coupling pin insertion hole 12.

The connecting pin 17 is press-fitted into the award hole 16.

In the embodiment of the mold guide device for a mold for molding a disc-shaped part according to the present invention, as shown in FIG. 2, the axis of each guide post has a diameter D with respect to the mold center point 0. arranged on concentric circles.

The axial direction of the coupling pin 17 is a concentric circle (
(diameter D) (the radial direction of the center point 0).

In the embodiment device having the above configuration, if the fixed substrate 1 is at a higher temperature than the movable substrate 2, the fixed guide post base 9 and the guide post movable portion 13 move outward as a unit when the mold is opened.

As shown in FIG. 3, when the mold is clamped, the tip of the cylindrical part 14 of the guide post movable part 13 comes into contact with the guide bush temporarily attached to the movable side base, and at the same time the movable guide post member 13 is guided to the guide busher 8. and can be displaced along the coupling pin 17 in the direction toward the center of the mold by the difference in thermal expansion due to the temperature of each substrate.

At this time, the important thing is that the center point O of each mold on the fixed side and the movable side must be coaxial and immovable.
In Figure 2, if the normal lines connecting the center of each pair of guide posts are x-x' and Y-Y', then
“If the amount of displacement of each guide post in the direction is different, and the displacement on the Y
' Each guide pin acts as a support and works to prevent uneven displacement in the x-x' direction, so the mold center point 0 in the XX° direction on the movable side is aligned with the axis of the stationary mold center point 0. Forced to match the heart position.

On the other hand, since non-uniform displacement in the Y-Y' direction can be considered in the same way, the center points O of each mold can always be made to coincide.

(Effects of the Invention) The mold guide device for a mold according to the present invention connects a stationary mold assembly and a movable mold assembly by a guide post provided on one side and a guide bush provided on the other side. In a mold guide device for a mold for molding a disk-shaped part, the guide post is placed approximately equidistant from the center of the mold assembly. They are arranged so as to be slidable in the radial direction at equally divided angular positions.

Therefore, in conventional disk molding molds, when the guide post is inserted into the guide bush, the misalignment of the guide post and guide bush due to the temperature difference between the fixed side and movable side of the mold. It is possible to almost eliminate the phenomenon of damage to both members due to bending stress and excessive surface pressure.

At the same time, as mentioned above, there is no misalignment between the center points of the fixed and movable molds, which is particularly important in disc molding molds, and the guide post inserted into the guide bush bends due to bending stress. When the mold is opened after completion, the mold does not vibrate or shock due to the repulsive force when it returns to its original state the moment it leaves the guide bush.

Therefore, the effect of preventing accidents of damage and deformation of the uneven signals transferred from the stamper plate to one surface of the resin molding is great.

In addition, the structure of the member has sufficient rigidity, and
Since it is simple, it has good accuracy and has the advantage of being inexpensive to manufacture.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view and a plan view of a guide post of an embodiment of a mold guide device for a mold for molding a disc-shaped part according to the present invention (X-X' in FIG. 2). FIG. FIG. 2 is a sectional plan view of a mold device for molding a disc-shaped part. FIG. 3 is a sectional view showing a state in which the guide post is fitted into the guide bush in the mold clamping state in the mold apparatus. FIG. 4 is a cross-sectional view for explaining the problems of the mold guide device of a conventional mold for molding disc-shaped parts. l...Fixed side substrate 2...Fixed side cavity 3...Movable side base handling 4...Movable side cavity 5...Molding cavity 6...Stand bar plate 7...Guide post 8... ... Guide bush 9 ... Guide post base 0 ... Guide post 1 ... Guide post 2 ... Guide post 3 ... Guide boss 4 ... Guide post 5 ... ...Guide post 6...Through hole 7...Threaded hole for the bolt at the base of the coupling pin, Cylindrical counterbore hole at the base, Coupling pin insertion hole at the base, Movable part, Fitting part of the movable part. Stepped cylindrical protrusion of the part Patent applicant: Elliptic Engineering Co., Ltd. 1. Representative of Sumitomo Heavy Industries, Ltd. Patent attorney: Hisao Inoro Figures 3 and 4

Claims (4)

[Claims] (1) In a mold guide device for a mold for molding a disc-shaped part in which a fixed side mold assembly and a movable side mold assembly are connected by a guide post provided on one side and a guide bush provided on the other side. , A mold for molding a disc-shaped part, characterized in that the guide posts are arranged so as to be slidable in the radial direction at approximately equal distances from the center of the mold assembly and at equal division angles. Guidance device. (2) At the center of the fixed side mold assembly and the movable side mold assembly of the mold guide device of the mold for molding the disk-shaped part, respectively.
A stamper plate with a concentric concave and convex symbol is provided on one of the fixed side mold and the movable side mold with a disc-shaped cavity, and each mold is fixed in the optical disc molding cavity formed by pressing the molds face-to-face with the coaxial center. 2. The mold guiding device for a mold for molding a disc-shaped component according to claim 1, which is an optical disc molding mold device for injecting and molding molten resin at high pressure from an injection hole in the center of a side mold. (3) For the guide posts, 3 or 4 guide posts are provided on one mold assembly at equidistant positions on a concentric circle from the mold center, and the other mold is precisely aligned with the guide posts. This is a precision positioning guide device for each mold, which is constructed by arranging the same number of guide bushes at the same position so that each guide post can be inserted in the same direction. 2. The mold guide device for a mold for molding a disc-shaped component according to claim 1, wherein the tip member is divided into two parts and connected by a connecting pin. (4) The engaging part of the two members of the guide post is such that one member has a cylindrical counterbore hole and a through hole perpendicular to the axis, and the other member has a height equivalent to that of the cylindrical counterbore hole. , a stepped cylindrical protrusion having an outer diameter smaller than the cylindrical counterbore, and a through-hole having the same diameter and coaxial with the through-hole in the part when the cylindrical protrusion is inserted into the counterbore,
By inserting the coupling pin into the common through hole, the above 2.
2. The disc-shaped component according to claim 1, wherein the member having the cylindrical protrusion can be moved in parallel in the axial direction of the coupling pin by the gap between the cylindrical counterbore and the cylindrical protrusion. A mold guide device for molds that mold.