JPS6237709Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for forming disk-shaped recording media such as audio records and video discs.

Conventional methods for molding audio records include compression molding by inserting preformed materials between molds (stampers), and two methods: one is compression molding by inserting a preformed material between stampers, and the other is using an injection machine to place the materials facing each other with a spacing of a few millimeters between them. An injection compression molding method is generally employed in which material is injected between molds and then compression molded.

In general, in compression molding preforming, the material surface becomes hard, stabilizers etc. ooze out, and foreign matter adheres to the material surface, all of which can stain and damage the stamper surface, but injection compression molding With this method, these drawbacks can be greatly improved because the material can be molded in a state with good fluidity by high-temperature injection for a short period of time.

In the injection compression molding method, since the mold is almost closed, it is difficult for foreign matter to enter the mold, and even if foreign matter enters between the molds due to the air flow caused by the mold closing operation or the material injection operation, it is easily ejected.

As described above, the injection compression molding method has the advantage of reducing the causes of surface defects on disks.

However, the conventional injection compression molding apparatus for records has a combination structure of a horizontal injection machine and a vertically opposed mold clamp, and therefore has the following problems, especially when molding high quality recording media such as video discs.

(b) Since the mold is installed vertically, the weight of the injected material itself tends to tilt downward, making it difficult to mold a disk with a uniform thickness. Therefore, it is difficult to set optimum molding conditions due to constraints such as the setting of the mold interval during material injection, the setting of the mold clamping timing, and the mold cooling cycle.

(b) The weight of the movable parts of the injection machine and mold clamping machine becomes a horizontal load on the guide members and tie bars, which increases the size of each mechanical element, increasing the volume, installation area, and weight of the entire machine.

In addition, the height of the mold clamping machine needs to be approximately 75cm to make it easier to work with when installing and removing molds and handling disks, which inevitably requires a large space under the injection machine and mold clamping machine. The whole area has a very large volume. Particularly in a system in which a plurality of molding machines are operated by a centralized hydraulic pressure generator, the lower space becomes a completely wasted space. Since video disks are particularly sensitive to dust during molding, it is necessary to install the molding machine in a clean room, and the large volume and installation area of the machine poses a major obstacle.

(c) It takes time and effort to remove and install the vertical mold. In addition, in the case of video disks, in order to improve the centering accuracy of the front and back sides of the disk, a centering configuration is sometimes adopted using guide pins of the mold, regardless of the guide accuracy of the tie bar, but in this case, one side of the mold is It is necessary to install the mold so that it can be moved in the direction, which is practically impossible because the weight of the mold is placed on the guide pin.

For molding high-quality disk-shaped recording media, we use a molding device that takes advantage of the above-mentioned features of injection compression molding machines and eliminates their drawbacks, and has a horizontally opposed mold clamping machine and a vertical injection machine attached to its upper fixed plate. considered optimal.

In the disk-shaped recording medium forming apparatus having such a configuration, since the injection machine is configured as a vertical injection machine, the injection cylinder tip formed in the upper fixed plate enters the upper part, and the space between the stampers and the resin material injection hole of the mold is passed through the space inside the fixed plate. The structure makes it easy for foreign matter to enter. The present invention provides a molding apparatus configured to solve this drawback.

The details of this invention will be explained below with reference to illustrated embodiments.

FIG. 1 is a front view of a disc-shaped recording medium forming apparatus according to the present invention, and FIG. 2 is a side view, in which 1 is a lower fixing plate;
Reference numeral 2 denotes an upper fixing plate, and these two are connected by tie bars 3, 3'. 4 is a movable plate, which is slidably inserted into the tie bars 3 and 3';
The movable plate 4 is moved up and down between the fixed plates 1 and 2 by a mold clamping mechanism consisting of a ram 5 and a cylinder 6 provided in the lower fixed plate 1. 7 is a lower mold for forming a disc-shaped recording medium fixed to the upper surface of the movable plate 4; 8 is an upper fixed plate 2;
The upper mold is fixed to the lower surface of the. The molds 7 and 8 are moved by a first driving means consisting of the mold clamping mechanism and a hydraulic control circuit (not shown) to the disc-shaped recording medium ejection position shown in FIG. They are controlled to three positions: a position where they are spaced at a minute interval during material injection as shown, and a clamping position where both are pressed together (not shown).

Note that the means for raising the lower mold 7 from the disk-shaped recording medium take-out position to the minute gap opening position is a commonly used auxiliary cylinder that is used to raise the lower mold 7 at high speed, thereby shortening the molding time. is possible. Reference numerals 9 and 9' denote a pair of mutually parallel guide shafts installed vertically on both sides of the upper part of the upper fixing plate 2, whose upper ends are integrally connected by a support member 10, and which control the vertical movement of the injection cylinder 11. It is used as a guide member for Further, movable cylinders 12, 12' which are operated by hydraulic pressure are slidably mounted on the guide shafts 9, 9', and the injection cylinder 11 is attached to the movable cylinders 12, 12'.
A holding member 13 is fixed to the moving cylinder 1.
Reference numerals 2 and 12' constitute a second driving means which also serves as a sliding mechanism for vertically moving the holding member 13 along the guide shafts 9 and 9'. A hopper 14 is adapted to supply material to the injection cylinder 11 via the holding member 13.

FIG. 3 shows details of the structure around the second driving means and the injection cylinder 11.

Around the guide shafts 9, 9', there is a piston member 1 along with the movable cylinders 12, 12'.
The piston members 15, 15' are fixed to the guide shafts 9, 9', respectively, so as to be in sliding contact with the inner walls of the movable cylinders 12, 12', and are provided within the shafts 9, 9'. are upward hydraulic passages 1 which communicate with two oil chambers between the moving cylinders 12, 12' and the guide shafts 9, 9', which are partitioned by piston members 15, 15'.
6, 16' and lowering hydraulic passages 17, 17' are provided on the upper fixed plate 2.
It is penetrated from 8, 18'. Further, the holding member 13 is rotatably mounted inside the upper part of the movable cylinders 12, 12' with shaft members 19, 19', and as shown in FIG. It can be rotated around the shaft members 19, 19', and is configured to facilitate maintenance such as taking out the screw 20 and cleaning the injection cylinder 11. Further, normally, the movable cylinders 12, 12' and the holding member 13 are fixed by a locking mechanism (not shown) so that the injection cylinder 11 is set vertically. In this way, the second driving means uses the pair of guide shafts 9, 9' and the moving cylinders 12, 12' to move the holding member 1 in a well-balanced manner.
3 and the injection cylinder 11, and also serves as a sliding mechanism for raising and lowering, the mechanism can be simplified with light weight and small size, and the overall height can be reduced. In addition, the holding member 13 is connected to two moving cylinders 12, 1.
2', and since they are connected by the shaft member 19, it also serves as a rotation mechanism for the injection cylinder 11, making it possible to achieve a small size and light weight with a simple mechanism.

In addition, in FIG. 3, the holding member 13 has a pair of piston rods 2 provided vertically in parallel.
Piston part 2 fixed to 1 and 21' respectively
2, 22' and oil cylinders 23, 23' are provided, and a screw 20 is connected to the upper end of the piston rod 21, 21' via a screw rotation driving means 25 attached to a seat plate 24, and a third driving means is provided. It consists of The injection cylinder 11 is installed vertically by penetrating the rear end of the center of the holding member 13, and the nozzle 26 at the tip is installed in the center of the upper mold 8 through a hole 27 protruding from the center of the upper fixing plate 2. The nozzle receiver 28 is pressed with a predetermined pressure. Reference numerals 29 and 29' denote stampers for forming a disc-shaped recording medium on which signals such as sound recording or video recording are recorded, and are closely fixed to the upper molds 8 and 7, although details are omitted. The third driving means described above is divided into a pair of piston rods 21, 21' and cylinders 23, 23' and arranged in parallel, and is also connected to the squew 20 and the moving cylinders 12, 12' of the second driving means. Since they are installed in almost parallel positions, the overall height can be shortened and the size can be made smaller. The screw 20 in FIG. 3 shows the positional relationship immediately before material injection into the molds 7 and 8, and FIG. 4 shows the positional relationship between the screw 20 and the piston rod 2.
1 and 21' are lowered and material is injected and supplied from the tip of the screw 20 between the molds 7 and 8. The molds 7 and 8 may be molded by repeated heating and cooling with steam and water, as in general compression molding, or molded by holding the mold at a constant temperature, as in a general injection molding machine. good.

In this apparatus for forming a disc-shaped recording medium, it is necessary to prevent foreign matter from entering between the stampers 29 and 29' as much as possible.

First, consider the operation shown in the cross-sectional views of FIGS. 3 and 4. The nozzle 26 is connected to the nozzle receiver 28
In this state, no foreign matter will fall into the nozzle receiver. However, during operation, airborne particles, rust, etc.
There is a risk of oil leaking from sliding parts or other unpredictable foreign objects entering. When molding is temporarily stopped and the injection cylinder is raised in order to replace the stamper or raw materials, the above-mentioned foreign matter may pass through the nozzle receiver and into the stamper 29, 2.
It falls between 9'. In order to eliminate such drawbacks, shielding tubes A and B, 30 and 31, are provided as an example. The shielding cylinder A30 is attached to the injection cylinder 11. One end is attached near the root of the nozzle so as not to create a gap in the nozzle. From there, the shielding cylinder A30 rises along the injection cylinder 11 to a position higher than the upper surface of the upper fixing plate when the disc-shaped recording medium forming device is in operation, then spreads out in a conical shape toward the outer circumference, and further extends below the end thereof. It has a configuration in which a folded portion 30a is provided in the direction. The shielding cylinder B31 is attached to the upper surface of the upper fixing plate 2. This shielding tube B31
A bank is formed on the outer periphery of the hole 27 of the upper fixing plate 2, and its outer diameter is configured to fit inside the folded part 30a of the shielding tube A30, and the gap is made as small as possible. . Since the shielding cylinder A30 has an inverted conical shape with an open bottom, it serves to prevent rust and other foreign matter from the injection cylinder from accumulating and falling below it. The shielding cylinder B31 serves to prevent foreign matter that has fallen onto the upper fixing plate 2, leaked oil, etc. from entering the hole 27. Further, the shielding tubes A and B serve to shield the space inside the fixing plate of the hole 27 from the outside during operation.

Even when the present molding device is not in operation and the nozzle is upwardly separated from the nozzle receiver, by considering the dimensional relationship between the shielding plates A and B, the same shielding effect as in operation can be obtained. is possible.

As described above, according to the present invention, shielding tubes A and B
By providing this, it is possible to eliminate the disadvantage of foreign matter getting mixed in between the molds of a disk-shaped recording medium forming apparatus having horizontally opposed molds, and it is possible to improve the quality of the product and the life of the stamper.

[Brief explanation of the drawing]

FIG. 1 is a front view of a disk-shaped recording medium forming apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the same, and FIG.
4 and 4 are cross-sectional views of the same essential parts in different operating states, and FIG. 5 is a side view of the same device in different operating states. 1... Lower fixing plate, 2... Upper fixing plate, 3...
Tie bar, 4...Movable plate, 5...Ram, 6...Cylinder, 7...Lower mold, 8...Upper mold, 9,9'
...Guide shaft, 10...Support member, 11...
...Injection cylinder, 12, 12'...Moving cylinder, 13...Holding member, 14...Hopper, 1
5, 15'... Piston member, 16, 16'... Ascent hydraulic path, 17, 17'... Descending hydraulic path, 1
8, 18'... Support block, 19, 19'... Shaft member, 20... Screw, 21, 21'... Piston rod, 22, 22'... Piston part, 2
3, 23'...Hydraulic cylinder, 24...Seat plate, 2
5... Screw rotation drive means, 26... Nozzle, 27... Hole, 28... Nozzle receiver, 29,2
9'... Stamper, 30... Shielding cylinder A, 31
...Shielding tube B.

Claims (1)

[Claims for Utility Model Registration] (1) An upper mold installed horizontally on the lower surface of a fixed plate, and a movable plate located below the fixed plate that can come into contact with and separate from the fixed plate. A lower mold is provided to face the upper mold and the lower mold is provided above the fixing plate, the tip of which passes through a through hole provided in the fixing plate. a vertically movable injection cylinder for injecting molding resin between them; a first annular shielding plate protruding from the outer periphery of the through hole on the upper surface of the fixing plate; and a second shielding plate whose outer periphery is located on the outer periphery of the first dust shielding plate when the injection cylinder is lowered. (2) The second shielding plate consists of a conical body whose center is fixed to the tip of the injection cylinder and whose diameter gradually increases upward, and whose terminal end is bent downward. A disc-shaped recording medium forming apparatus according to claim 1 of the utility model registration claim.