JPH0929747A - Mold heat insulating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a mechanism which does not make the heat quantity of a replaceable mold act on a platen without modifying a conventional precise molding machine with a simple structure. SOLUTION: Since a pair of heat insulating units 12 are detachable at a platen 2 and molds 7, 8 are detachable, a heat insulation unit 12 can be interposed when the molds 7, 8 are mounted. Since the unit 12 heat insulates the molds 7, 8 from the platen 2, the heats of the molds 7, 8 do not act on the platen 2.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a precision molding apparatus for precision molding a product such as an optical disk.

[0002]

2. Description of the Related Art First, a conventional example of a precision molding apparatus will be described below with reference to FIG. The precision molding apparatus 1 exemplified here is for precisely molding an optical disk (not shown) as a product, and a pair of platens 2 are supported by four tie bars 3 so as to be movable in contact and separation directions at positions facing each other. ing. A pair of temperature control plates 5 and 6 are individually mounted on the inner surfaces of the pair of platens 2 that face each other via a spacer 4 only on one side.
A pair of molds 7 and 8 are individually mounted on the inner surfaces of 6 facing each other.

The pair of molds 7 and 8 are formed in a shape corresponding to the optical disc to be molded, the inner surfaces facing each other, and between the inner surfaces facing each other when the molds 7 and 8 are integrally joined. The cavity 9 is formed as a gap. A flow path 10 is formed inside the temperature control plates 5 and 6,
A temperature control liquid supply device (not shown) for flowing the temperature control liquid in the flow path 10 is provided in the temperature control plates 5 and 6.

In the precision molding apparatus 1 as described above, since the molds 7 and 8 are exchangeable as described later, these molds 7 and 8 are formed with through holes through which bolts are inserted. A female screw to which a bolt is fastened is formed on the platen 2 (not shown).

The above-mentioned precision molding apparatus 1 can injection-mold an optical disc as a product. In that case, the pair of platens 2 are brought close to each other to integrally join the molds 7 and 8,
The molten resin is injected into the cavity 9 formed here. In such a state, the flow path 10 of the temperature control plates 5 and 6
Since the temperature control liquid is supplied to the molds 7, the molds 7 and 8 are temperature-controlled and gradually cooled. Since the resin is gradually cooled and solidified together with these molds 7 and 8, this is formed as an optical disk which is a product of injection molding.

[0006] In the precision molding apparatus 1 as described above, the molds 7 and 8 are detachably mounted, and by exchanging the molds, various products can be precision molded. In such a case, the platen 2 is separated and the molds 7 and 8 are mounted, and the molds 7 and 8 are heated to the same temperature as that at the time of molding.
Then, the platen 2 is moved closer to confirm the bonding condition of the molds 7 and 8, and the platen 2 is moved away from the molds 7 and 8 to adjust the mounting positions of the molds 7 and 8.

[0007]

The precision molding apparatus 1 described above can injection-mold an optical disk as a product by means of the cavities 9 of the molds 7 and 8 that are integrally joined.

However, since the resin injected into the cavity 9 is in a state of being heated to a high temperature and melted, the molds 7, 8 are
Will also be heated to high temperatures. When such a temperature acts on the platen 2, the tie bar 3, etc., the positions of the molds 7 and 8 change due to their thermal expansion, and the yield of precision molding decreases.

In order to solve such a problem, Japanese Unexamined Patent Publication No.
In the molding device disclosed in Japanese Patent No. 162142, a heat insulating portion is provided between the mold and the platen. This heat insulating part is composed of a cooling plate having a flow passage formed inside, and the heat generated by the mold is absorbed by the cooling water flowing in the flow passage so that it does not act on the platen. According to the above publication, the heat insulating portion is provided as a part of the mold, and it can be provided as a part of the platen.

When the heat insulating part is provided as a part of the mold as described above, it is possible to modify the existing mold to add the heat insulating part. However, as mentioned above, the precision molding equipment replaces many kinds of molds for each product, and thus providing a heat insulating part in each of the many kinds of molds is complicated and the number of parts of the entire system is large. Also increases.

On the other hand, when the heat insulating portion is provided as a part of the platen, the heat insulating portion may be a pair even if there are many kinds of molds. However, since the shape and area of the heat generating part of the mold differ depending on the product to be molded, it is difficult to properly absorb such heat generation with one type of heat insulating part, and it is difficult to partially heat the platen There is concern about partial overcooling of the mold.

Further, as described above, the platen 2 is attached to the mold 7,
When mounting and adjusting the position of the molds 8, the molds 7 and 8 are heated to the same temperature as that at the time of molding, but it takes time to perform such heating, and thus it is difficult to quickly perform the work. Is.

[0013]

According to a first aspect of the present invention, there is provided a pair of a platen having a detachable plate mounting portion and a die detachable mold mounting portion for insulating the die and the platen from each other. With a heat insulation unit. Since the pair of heat insulating units has the plate mounting portion that is detachable from the platen and the mold mounting portion that is detachable from the mold, the die can be mounted on the platen via the heat insulating unit. Since the mold and the platen are insulated from each other, the heat generated by the mold does not act on the platen.

According to the second aspect of the present invention, the mold has a pair of heat insulating units that absorb the amount of heat generated during molding and do not act on the platen. The heat insulating units are detachably mounted on the platen and the mold is also attached. Is detachably attached. Since the pair of heat insulating units are detachably attached to the platen and the die is detachably attached, the die can be attached to the platen via the heat insulating unit,
This heat insulating unit absorbs the amount of heat generated by the mold during molding, so that the heat generated by the mold does not act on the platen.

According to the third aspect of the present invention, the heat insulating unit has a flow passage formed therein, and the forced cooling mechanism causes the cooling fluid to flow in the flow passage. It absorbs the amount of heat transferred from the mold and does not act on the platen.

In the invention according to claim 4, the flow passage is formed in an intersecting shape having a plurality of intersections, and since the flow passage switching mechanism provided at the intersection of the flow passages changes the flow direction, heat insulation is performed. The shape of the part where the unit absorbs heat can be changed.

According to the fifth aspect of the present invention, the forced cooling mechanism has the flow rate adjusting mechanism for adjusting the flow rate of the cooling fluid, so that the amount of heat absorbed by the heat insulating unit can be changed.

According to the sixth aspect of the present invention, the flow rate adjusting mechanism has a temperature sensor for detecting the temperature of the platen, and adjusts the flow rate of the cooling fluid according to the temperature of the platen.
The amount of heat absorbed by the heat insulating unit is appropriately adjusted according to the temperature of the platen.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. Note that, regarding this embodiment, the same portions as those of the above-described conventional example use the same names and reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, the mold heat insulating device 11 is
It has a cooling plate 12 which is a pair of heat insulating units. In the pair of cooling plates 12, female screws (not shown) are formed on one of the plate surfaces serving as the plate mounting portion, similarly to the molds 7 and 8, and on the other plate surface serving as the mold mounting portion,
Like the platen 2, through holes for bolts are formed.
Therefore, the cooling plate 12 has one plate surface detachably mounted on the platen 2, and the molds 7 and 8 are mounted detachably on the other plate surface. The cooling plate 12 has a channel 13 formed therein, and the channel 1
3, a forced cooling mechanism 15 is connected by a heat-resistant hose 14 made of fluororesin.

As shown in FIG. 2, the cooling plate 12
The flow path 13 is formed in an intersecting shape having a plurality of intersections, and a two-way valve 16 or a three-way valve 17 is provided at the intersection as a flow path switching mechanism for changing the flow direction. The intersecting shape of the flow passages 13 is, for example, a shape in which a large number of flow passages communicating in the up-down direction and a large number of flow passages communicating in the left-right direction intersect in a mesh shape.

The forced cooling mechanism 15 has, for example, a structure in which a radiator and a rotary pump are combined, and a flow valve 18 for adjusting a flow rate is provided at a discharge port for supplying cooling water as a cooling fluid to the cooling plate 12. It is provided. A drive control circuit 19, which is a flow rate adjusting mechanism, is connected to a solenoid (not shown) that drives the flow rate valve 18 of the forced cooling mechanism 15.
A temperature sensor 21 such as a thermistor is connected by a bendable wiring cord 20 (not shown). The temperature sensor 21 includes a magnet and a suction cup, and is detachably attached to the platen 2.

In such a configuration, the precision molding device 1
When the optical disc is injection-molded as a product by the cavity 9 of the molds 7 and 8, the mold heat insulating device 11 insulates the molds 7 and 8 and the platen 2 by the cooling plate 12. Therefore, the heat generated by the molds 7 and 8 for molding the product does not act on the platen 2, and molding defects due to thermal expansion of the platen 2 and the tie bar 3 are prevented.

More specifically, by supplying a high temperature temperature control liquid to the flow passages 10 of the temperature control plates 5 and 6, the molds 7,
The cavities 9 of 8 are preheated to an optimum temperature. This temperature is 100 to 120 (° C) for precision molding and 50 to 80 for high speed molding.
Since it is (° C), the mold 7, which has been preheated to such a temperature,
The resin melted by being heated to 300 (° C.) or higher is injected into the cavity 9 of No. 8. The resin thus injected into the cavity 9 is cooled and solidified together with the molds 7 and 8. Therefore, by separating the molds 7 and 8 and taking out the solidified resin from the cavity 9, a molded product is obtained. An optical disc can be obtained.

At this time, the amount of heat conducted from the resin to the molds 7 and 8 is absorbed to some extent by the temperature control liquid of the temperature control plates 5 and 6, but not entirely absorbed and together with the amount of heat of the temperature control liquid. It is conducted to the cooling plate 12. This cooling plate 12 has a flow path 1
Since the cooling water is flowing in the plate 3, the amount of heat conducted by the cooling water is absorbed and does not act on the platen 2. For this reason, the platen 2 and the tie bar 3 are prevented from being deformed by heat transfer, and the defective molding due to the displacement of the molds 7 and 8 is prevented.

The mold heat insulating device 11 illustrated here can prevent the heat amount of the molds 7, 8 and the temperature control plates 5, 6 from acting on the platen 2 as described above, but the cooling plate 12 thereof is the platen. It is independent of 2 and molds 7 and 8. Therefore, there is no need to modify the conventional precision molding device 1,
Even when the precision molding apparatus 1 exchanges various types of molds 7 and 8 for each product, it is sufficient to incorporate one mold heat insulating device 11, and therefore the configuration of the entire system is simple.

In the precision molding device 1 as described above,
The molds 7 and 8 are replaced each time the product to be molded is changed,
In such a case, the amount of heat generated by the molds 7 and 8 may change. However, in the mold heat insulating device 11 described above, since the flow rate of the cooling water flowing through the cooling plate 12 by the forced cooling mechanism 15 can be adjusted by the flow valve 18, the heat quantity generated by the molds 7 and 8 can be controlled by the cooling plate. 12
Can be appropriately absorbed by the flowing cooling water, and the heating of the platen 2 and the supercooling of the molds 7 and 8 can be prevented. Moreover, when the flow valve 18 of the forced cooling mechanism 15 operates as described above, the drive control circuit 19 detects the temperature of the platen 2 by the temperature sensor 21 and adjusts the flow rate of the cooling water according to this temperature. The flow rate of cooling water is adjusted in real time with a simple structure.

Further, when the molds 7 and 8 of the precision molding apparatus 1 are exchanged as described above, the shape and area of the heat generating portion may change. However, in the mold heat insulating device 11 described above, the flow path 13 of the cooling plate 12 is formed in an intersecting shape having a plurality of intersections, and the flow direction of the intersections of the flow paths is controlled by the two-way valve 16 or the three-way valve 17. Since it can be changed, the shape and area of the portion where the cooling plate 12 absorbs the amount of heat of the molds 7 and 8 can be adjusted as desired, and the partial heating of the platen 2 and the portion of the molds 7 and 8 can be performed. Supercooling can also be prevented.

Further, in the above-mentioned precision molding apparatus 1, when the molds 7 and 8 are replaced, the entire system is heated to the same temperature as that at the time of molding to precisely adjust the mounting positions of the molds 7 and 8. However, in such a case, the flow path 1 of the cooling plate 12
Since the whole system can be heated in a short time by supplying the hot water to 3, the above-described adjustment work can be executed quickly and accurately.

[0030]

According to the first aspect of the present invention, the pair of platens are supported by the tie bars so as to be movable in the contact and separation directions at the opposite positions, and the pair of molds are detachably attached to the pair of platens. However, in a precision molding device that molds a product in one cavity formed by a pair of molds that are integrally joined, a plate mounting part that is removable from the platen and a mold mounting part that is removable from the mold are provided. By having a pair of heat insulation units that insulate the mold and platen from each other, the heat quantity of the mold for molding the product can be prevented from acting on the platen by the heat insulation unit, so that the platen and the tie bar are deformed by heat transfer. Molding failure due to this is prevented, and since such a heat insulating unit is independent of the platen and mold, it is not necessary to modify the conventional precision molding equipment, Since it may be mold insulating device in one when replacing the many types of molds for each goods, construction of the whole system is simple.

According to the second aspect of the present invention, a pair of platens are supported by tie bars so as to be movable in the contact and separation directions at opposite positions, and a pair of molds are detachably attached to the pair of platens, respectively. In a precision molding apparatus that molds a product in one cavity formed by a pair of molds that are integrally joined, the mold has a pair of heat insulating units that absorb the amount of heat generated during molding and do not act on the platen, This heat insulation unit is detachably attached to the platen and the die is detachably attached, so that the heat quantity of the die for molding the product can be prevented from acting on the platen by the heat insulation unit. Molding defects due to heat transfer are prevented.Since such a heat insulation unit is independent of the platen and mold, it is possible to use conventional precision molding equipment. There is no need to modify the so precision molding apparatus is good in one mold insulating device even when exchanging various kinds of molds for each product, the structure of the whole system is simple.

According to the third aspect of the present invention, the heat insulating unit has the flow passage formed therein, and the forced cooling mechanism for flowing the cooling fluid is provided in the flow passage. Can be absorbed by the flowing cooling fluid, so that the platen can be insulated from the mold with a simple structure.

In the invention according to claim 4, the flow passage is formed in an intersecting shape having a plurality of intersections, and the flow passage switching mechanism for changing the flow direction is provided at the intersection of the flow passages. Even if the shape or area where heat is generated changes due to mold replacement, the shape and area where the heat insulating unit absorbs the heat can be adjusted so that the platen is partially heated and the mold is partially supercooled. Can be prevented.

According to the fifth aspect of the present invention, the forced cooling mechanism has the flow rate adjusting mechanism for adjusting the flow rate of the cooling fluid, so that the heat insulating unit absorbs even if the amount of heat generated by the replacement of the mold changes. Since the amount of heat can be matched, heating of the platen and overcooling of the mold can be prevented.

According to the sixth aspect of the invention, the flow rate adjusting mechanism has a temperature sensor for detecting the temperature of the platen, and the heat insulating unit absorbs by adjusting the flow rate of the cooling fluid corresponding to the temperature of the platen. The amount of heat can be adjusted in real time according to the temperature of the platen.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a state in which a mold heat insulating device according to an embodiment of the present invention is mounted on a precision molding device.

FIG. 2 is a plan view showing a flow path of a cooling plate which is a heat insulating unit.

FIG. 3 is a vertical sectional side view showing a precision molding device of a conventional example.

[Explanation of symbols]

 1 Precision Molding Device 2 Platen 3 Tie Bar 7,8 Mold 9 Cavity 11 Mold Insulation Device 12 Heat Insulation Unit 13 Flow Path 15 Forced Cooling Mechanism 16,17 Flow Path Switching Mechanism 19 Flow Control Mechanism 21 Temperature Sensor

Front page continuation (72) Inventor Tomohiro Mitani 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd.

Claims (6)

[Claims] 1. A pair of platens supported by a pair of tie bars so as to be movable in the contact and separation directions at positions facing each other, and a pair of molds are detachably attached to the pair of platens individually, and the pair is integrally joined. In a precision molding apparatus for molding a product in one cavity formed by the mold, the mold is provided with a plate mounting part that is removable from the platen and a mold mounting part that is removable from the mold. A mold heat insulating device having a pair of heat insulating units for insulating the platen and the platen from each other. 2. A pair of platens supported by a tie bar so as to be movable in the contact and separation directions at opposite positions, and a pair of molds are detachably attached to the pair of platens individually, and the pair is integrally joined. In a precision molding device for molding a product in one cavity formed by the mold, the mold has a pair of heat insulating units that absorb the amount of heat generated during molding and do not act on the platen. Is a mold heat insulation device, wherein the mold is detachably mounted on the platen and the mold is detachably mounted. 3. The mold heat insulating device according to claim 1, wherein the heat insulating unit has a flow passage formed therein, and a forced cooling mechanism for flowing a cooling fluid is provided in the flow passage. . 4. The flow path is formed in a cross shape having a plurality of intersections, and a flow path switching mechanism for changing the flow direction is provided at the intersection of the flow paths. Mold insulation device. 5. The mold heat insulating apparatus according to claim 3, wherein the forced cooling mechanism has a flow rate adjusting mechanism that adjusts the flow rate of the cooling fluid. 6. The heat insulating mold according to claim 5, wherein the flow rate adjusting mechanism has a temperature sensor for detecting the temperature of the platen, and adjusts the flow rate of the cooling fluid according to the temperature of the platen. apparatus.