JP2003145538A - Molding die and method for manufacturing molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding die which is capable of rapidly heating and quenching the wall surface of a cavity and thereby, enhancing the fluidity and transferability of a resin and at the same time, shortening a molding cycle and upgrading the quality of a product and its productivity, and a method for manufacturing the molding die. SOLUTION: This molding die is configured of a cavity members 7 and 8 which are fitted to the mold bodies 5 and 6 of a cavity side half 2 and a movable half 3 and constitute a cavity 4 and heat insulating plates 9 and 10 provided on the cavity face sides 7a and 8a opposite to the cavity members 7 and 8. In addition, grooves 23 and 24 which constitute temperature control water circuits 21 and 22 are formed in the cavity face sides 7a and 8a opposite to the cavity members 7 and 8 and the grooves 23 and 24 are arranged between the cavity members 7 and 8 and the heat insulating plates 9 and 10 respectively. Thus the temperature control water circuits 21 and 22 are formed near the wall face of the cavity 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die used when a resin product is molded by injection molding or the like, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, in the case of molding various resin products by injection foam molding, as shown in FIG. 2, a product cavity 52 formed in a molding die 51 corresponding to the shape of the product is plasticized. The molten resin 55 is injected and injected from the nozzle 54 of the device 53 through the resin injection portion (gate). Therefore, the molding die 51 includes a fixed die 57 attached to the fixed plate 56 and a movable die 59 attached to the movable plate 58. First, the mold 51 is once closed by the "die closing" operation. After "clamping / pressurizing", the mold 51 is opened by a predetermined amount of opening (core back) by "moving inward" (core back), "moving in stop" is held by opening and the "injection filling" operation is performed. Molten resin 5 as a molding material in the cavity 52
5 is filled and injection holding pressure is performed. Next, during the “mold clamping / holding” after the “mold clamping / pressurizing”, the molten resin 55 for the next shot is “plasticized”, and after “mold clamping / pressurizing”,
When the mold 51 is opened by the "mold opening" operation and "product takeout" is performed, one cycle of injection molding is completed.

By the way, a molding die 5 having such a structure is used.
In order to improve the quality of the resin product and to improve the productivity by shortening the molding cycle time, the wall surface of the cavity 52 can be switched between high temperature and low temperature in a short time (rapid heating and cooling). Is required. Therefore, in the conventional mold heating / cooling method, for example, when the mold is opened, the wall temperature of the cavity 52 is heated to the glass transition temperature or higher by an induction heating coil or the like, and the mold is clamped before the wall temperature of the cavity 52 decreases. After closing and filling with the molten resin 55, a cooling fluid is caused to flow through a cooling pipe (not shown) in the mold 51 to cool the mold 51, and then the resin product is taken out.

[0004]

However, in the above-mentioned conventional molding die 51, it takes a long time from the heating to the injection and injection of the molten resin 55, and the die temperature is lowered, so that the cavity is not heated. If the wall temperature of 52 cannot be increased, but the temperature of the entire mold is increased,
There is a possibility that the mold cooling time thereafter may increase. Further, the method of heating the induction heating plate close to the wall surface of the product cavity 52 has a problem that the cavity 52 can only support a flat wall surface shape. In addition to this, the cooling pipe in the mold 51 is arranged away from the wall surface of the cavity 52 because of structural reasons and a complicated processing method for approaching the wall surface of the cavity. The cooling efficiency for the wall surface of the mold was poor, and the mold 51 could not be cooled rapidly before the mold opening operation after the injection and filling of the molten resin 55. Therefore, in the conventional molding die 51, it is difficult to control the temperature of the wall surface of the cavity 52 at high and low temperatures in a short time, so that it is not possible to sufficiently save energy at the time of molding, which leads to improvement of product quality and productivity. It was also difficult to maintain and improve.

The present invention has been made in view of the above circumstances, and an object thereof is to enable rapid heating and cooling of the wall surface of the cavity, thereby improving the fluidity and transferability of the resin and molding the resin. It is an object of the present invention to provide a molding die capable of shortening the cycle time and improving product quality and productivity, and a manufacturing method thereof.

[0006]

In order to solve the above-mentioned problems of the prior art, the present invention relates to a cavity member which is attached to a mold body, and a part of the surface of which constitutes a wall surface of the cavity, and A heat insulating material provided on the anti-cavity surface side of the cavity member, and forming a groove constituting a temperature control circuit on the anti-cavity surface of the cavity member, the groove being provided between the cavity member and the heat insulating material. By arranging, the temperature control circuit is provided near the wall surface of the cavity.

Further, according to the present invention, a groove for a temperature control water circuit is formed on an anti-cavity surface of a cavity member, a part of the surface of which constitutes the wall surface of the cavity, and the groove is filled with a filling material and embedded. In this state, the cavity member is attached to the mold body, positioned so that a space is formed between the cavity surface of the cavity member and the mold body, and a liquid resin is poured into the space. A heat insulating material is formed by curing, and then the entire mold is heated, and the filler filled in the groove of the cavity member is melted and flown out, so that the temperature control water near the wall surface of the cavity. A mold provided with a circuit is manufactured.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail based on the illustrated embodiments. Here, FIG. 1 is a sectional view of a molding die according to an embodiment of the present invention.

The molding die 1 according to the embodiment of the present invention is
For example, it is used when molding various resin products by injection foam molding, and as in the conventional example, "mold closing",
"Clamping / pressurizing", "Mold open", "Mold stop", "Mold open"
In addition, one cycle of injection molding is completed through each process such as "product taking out". Therefore, molding die 1
Includes a fixed mold 2 attached to a fixed plate (not shown) and a movable mold 3 attached to a movable plate (not shown),
The fixed mold 2 and the movable mold 3 are arranged so as to face each other between the fixed platen and the movable platen, and the movable platen (not shown) and the movable mold 3 are integrated by moving a mold clamping ram (not shown). Is configured to move forward and backward.

A cavity 4 corresponding to the shape of the resin product is formed in the molding die 1, and a molten resin is injected and injected into the cavity 4 from a nozzle of a plasticizing device (not shown). It is like this. For this reason,
The fixed mold 2 and the movable mold 3 include mold bodies 5 and 6 including substrates 5a and 6a and holder molds 5b and 6b, and the mold bodies 5 and 5, respectively.
6 is provided with a cavity member 7 and a cavity member 8 that are attached to and held by the holder molds 5b and 6b of FIG. 6 and that form the cavity 4. Between the holder molds 5b and 6b and the cavity member 7 and the cavity member 8. Insulating plates (insulating materials) 9 and 10 are arranged in each. The cavity member 7 forms the product surface of the resin product, and the cavity member 8 forms the anti-product surface of the resin product.
Both plates 7 and 8 are made of a metal (for example, S45C) having a wall thickness of about 20 mm.

The mold body 5 of the fixed mold 2 has a sprue 11 communicating with a nozzle of a plasticizer (not shown), a hot runner 12 having a substantially U-shaped cross section communicating with the sprue 11, and a plurality of positioning pins 13. These positioning pins 13 project from the holder mold 5b toward the cavity 4 side, and the tips are arranged to be inserted into the positioning holes 14 of the cavity member 7. The cavity member 7 has a side runner 16 communicating with the hot runner 12 and the cavity 4 via the valve gate 15.
The valve gate 15 is opened and closed by a slidable piston pin 17 extending along the axial direction of the mold body 5. Further, the mold body 6 of the movable mold 3 is provided with a plurality of positioning pins 18 facing each other like the positioning pins 13 on the fixed mold 2 side, and these positioning pins 18 are held by the holder mold 6b. It projects further toward the cavity 4 side, and is arranged so that its tip portion is inserted into the positioning hole 19 of the cavity member 8. Moreover, the mold body 6 and the cavity member 8 are slidably provided with a plurality of protrusion pins 20 extending along the axial direction of the mold body 6, and the tips of the protrusion pins 20 are When the product is taken out, the resin product is ejected from the surface of the cavity member 8 so as to be pushed out to be detached.

The heat insulating plates 9 and 10 are insulators that block heat conduction to the mold bodies 5 and 6, and are anti-cavity surfaces of the cavity member 7 and the cavity member 8 (surfaces through which the injected and injected resin flows). Opposite side) 7a, 8a and holder mold 5b,
A liquid resin is poured into the spaces S1 and S2 formed between the space 6b and 6b and cured to form a predetermined shape. For this reason, the resin forming the heat insulating plates 9 and 10 is in a liquid state that can be poured into the spaces S1 and S2 at room temperature, and has a very small volume reduction when being heated or cured at room temperature, and has a strong adhesive force to the contact surface. Epoxy resin, which has excellent shapeability and is capable of following complex shapes, is used.

On the other hand, on the anti-cavity surfaces 7a, 8a of the cavity member 7 and the cavity member 8, a large number of grooves 23, 24 which will later constitute the temperature control water circuits 21, 22 are formed by cutting, grinding, or electric discharge machining. It is formed by. These grooves 23, 24 are provided at intervals along the horizontal direction (or the vertical direction) with respect to the cavity 4, and the depth thereof is, for example, about 1: 3 with respect to the wall thickness of the cavity member. It is formed to have a ratio. In addition, before the cavity member 7 and the cavity member 8 are attached to the mold bodies 5 and 6, the grooves 23 and 24 are filled and filled with wax (filler) to which the lost wax method is applied. By temporarily backfilling 23 and 24, the resin forming the heat insulating plates 9 and 10 is treated so as not to enter the grooves 23 and 24 when mounted on the mold bodies 5 and 6. Moreover, the wax has the property of being melted by the heating of the mold bodies 5 and 6 and flowing out from the grooves 23 and 24.

Therefore, when the cavity member 7 and the cavity member 8 are attached to the mold bodies 5 and 6,
The grooves 23 and 24 are the cavity member 7 and the cavity member 8.
And the heat insulating plates 9 and 10 are disposed between the heat insulating plates 9 and 10, so that the temperature control circuits 21 and 22 are provided near the wall surface of the cavity 4. This temperature control circuit 21,
Reference numeral 22 denotes hot water (about 140 ° C.) and cold water (about 20 ° C.) that are pressurized to rapidly heat and cool the temperature of the wall surface of the cavity 4.
(C) and water is passed therethrough, and air is introduced to prevent energy loss when hot water and cold water are introduced and switched. As a result, the wall surface of the cavity 4 becomes
It is heated to the crystallization temperature (Tc) or higher of the crystalline resin, or the glass transition temperature (Tg) or the flow start temperature (Tf) of the amorphous resin.

Next, a method of manufacturing the molding die 1 according to the embodiment of the present invention will be described. First, the anti-cavity surfaces 7a and 8a of the cavity member 7 and the cavity member 8 that form the cavity 4 are grooved to form a large number of grooves 2.
3 and 24 are formed. Then, the grooves 23, 24 are filled with wax by an appropriate means and embedded so that the grooves 23, 2
Block 4 Next, the cavity member 7 and the cavity member 8 in this state are arranged in the mold bodies 5 and 6 of the fixed mold 2 and the movable mold 3, and the positioning pins 13 and 18 protruding from the holder molds 5b and 6b are positioned in the positioning holes 14. , 19,
Moreover, the protrusion pin 20 is inserted into the cavity member 8, and spaces S1 and S2 are formed between the cavity member 7 and the anti-cavity surfaces 7a and 8a of the cavity member 8 and the holder molds 5b and 6b of the mold bodies 5 and 6, respectively. While being positioned as described above, it is attached to the mold bodies 5 and 6 by a fastener such as a screw. Then, the heat insulating plates 9 and 10 are formed by pouring a liquid epoxy resin into the spaces S1 and S2 by an appropriate means and heating or curing at room temperature. Thereafter, when the entire mold bodies 5 and 6 are heated, the wax filled in the grooves 23 and 24 of the cavity member 7 and the cavity member 8 is melted and flows out from these grooves 23 and 24.
Therefore, the temperature control water circuit 2 is provided near the wall surface of the cavity 4.
The molding die 1 including the fixed die 2 and the movable die 3 provided with 1 and 22 is obtained (see FIG. 1), and the manufacturing operation is completed.

In the molding die 1 according to the embodiment of the present invention, of the cavity member 7 and the cavity member 8 which are attached to the die bodies 5 and 6 of the fixed die 2 and the movable die 3 and constitute the wall surface of the cavity 4. Heat insulating plates 9 and 10 are provided on the side of the anti-cavity surfaces 7a and 8a, and a large number of grooves 23 and 24 are formed in the anti-cavity surfaces 7a and 8a of these plates 7 and 8, respectively. By arranging between the cavity member 8 and the heat insulating plates 9 and 10, the temperature control water circuits 21 and 22 are provided in the vicinity of the wall surface of the cavity 4, so that the temperature control water circuits 21 and 22 are filled with hot water and cold water. The wall surface temperature of the cavity 4 can be rapidly adjusted to a high or low temperature by switching between and to pass water. Therefore, if the molding die 1 of the present embodiment is used in the injection foam molding method, the wall temperature of the cavity 4 can be quickly changed to the glass transition temperature or the crystallization by the passage of hot water to the temperature control water circuits 21 and 22. It becomes possible to inject and fill the molten resin into the cavity 4 at a temperature higher than or equal to the temperature, and by passing cold water to the temperature control water circuits 21 and 22, the wall temperature of the cavity 4 is rapidly lowered, and It becomes possible to perform cooling in a short time. As a result, the flowability of the molten resin is improved in foam molding and injection at low pressure is possible, while the surface silver of the resin product can be suppressed, and the product surface gloss and transferability are dramatically improved in decorative molding, and the molding cycle time Can be made shorter than the conventional one.

Further, in the method for manufacturing the molding die 1 according to the embodiment of the present invention, the cavity member 7 constituting the wall surface of the cavity 4 and the anti-cavity surface 7 of the cavity member 8 are formed.
forming a large number of grooves 23, 24 in a, 8a,
3, 24 are filled with wax and embedded, the cavity member 7 and the cavity member 8 are attached to the holder molds 5b and 6b of the mold bodies 5 and 6, and the positioning pins 13 and 18 and the positioning holes 14 and 19 are fitted together. The cavity members 7 and 8 are positioned so that the spaces S1 and S2 are formed between the anti-cavity surfaces 7a and 8a of the cavity members 8 and the holder molds 5b and 6b, and the liquid epoxy resin is placed in these spaces S1 and S2. The heat insulating plates 9 and 10 are formed by pouring and hardening the mold, and then the entire mold bodies 5 and 6 are heated to form the groove 2 of the cavity member 7 and the cavity member 8.
By melting and flowing out the wax filled in 3, 24, the temperature control water circuits 21, 2 are formed in the vicinity of the wall surface of the cavity 4.
Since the molding die 1 provided with 2 is manufactured, the temperature control water circuits 21 and 22 for controlling the wall surface temperature of the cavity 4 and the heat insulating plate 9,
10 and 10 can be installed simultaneously and smoothly, and the manufacturing cost can be reduced.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications and changes can be made based on the technical idea of the present invention. is there. For example, the present invention can be applied to molds other than injection molds that require rapid heating and cooling.

[0019]

As described above, the molding die according to the present invention is provided with a cavity member which is attached to the die body and a part of the surface of which constitutes the wall surface of the cavity, and an anti-cavity surface of the cavity member. With a heat insulating material provided on the side,
A groove forming a temperature control water circuit is formed on the anti-cavity surface of the cavity member, and the groove is disposed between the cavity member and the heat insulating material, whereby the temperature control circuit is provided in the vicinity of the wall surface of the cavity. The wall surface of the cavity can be rapidly heated and cooled by switching between hot water and cold water in the temperature control water circuit because the temperature control water circuit is provided. It is possible to inject and fill molten resin into the cavity in this state, improve the fluidity and transferability of the resin, and shorten the molding cycle time.As a result, product quality and productivity can be improved, and during molding. It is possible to reduce costs by saving energy.

Further, in the method for manufacturing a molding die according to the present invention, a groove for a temperature control water circuit is formed on the anti-cavity surface of the cavity member, a part of the surface of which constitutes the wall surface of the cavity, and the groove is formed. Filling with a filling material and embedding it, and in this state, the cavity member is attached to the mold body, and the cavity member is positioned so that a space is formed between the anti-cavity surface of the cavity member and the mold body. Form a heat insulating material by pouring liquid resin into the space and curing it.
After that, the entire mold is heated, and the filler filled in the groove of the cavity member is melted and poured out to manufacture a mold in which the temperature control circuit is provided near the wall surface of the cavity. Therefore, the temperature control water circuit and the heat insulating material can be installed at the optimum position for rapid heating and cooling of the wall surface of the cavity at the same time, and a mold having excellent performance can be obtained at a lower cost than the conventional one.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a molding die according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a conventional molding die.

[Explanation of symbols]

1 Mold for molding 2 fixed type 3 movable 4 cavities 5,6 Mold body 7 Cavity member 7a Anti-cavity surface 8 cavity members 8a Anti-cavity surface 9,10 Insulation board (insulation material) 13,18 Positioning pin 14, 19 Positioning holes 21,22 Temperature control circuit 23, 24 groove S1, S2 space

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshihiko Kariya             1 Takamichi, Iwatsuka-cho, Nakamura-ku, Nagoya-shi, Aichi               Mitsubishi Heavy Industries Nagoya Research Center (72) Inventor Nobuya Hayashi             1 Takamichi, Iwatsuka-cho, Nakamura-ku, Nagoya-shi, Aichi               Mitsubishi Heavy Industries Nagoya Research Center F-term (reference) 4F202 AA39 AA49 CA11 CB01 CK06

Claims (6)

[Claims] 1. A cavity member, which is attached to a mold body and has a part of its surface forming a wall surface of a cavity, and a heat insulating material provided on the side opposite to the cavity surface of the cavity member. A groove for forming a temperature control water circuit is formed on the anti-cavity surface, and the temperature control water circuit is provided near the wall surface of the cavity by disposing the groove between the cavity member and the heat insulating material. Molding die characterized by. 2. The plurality of grooves of the cavity member are provided at intervals along a longitudinal direction, a lateral direction, or an oblique direction of an arbitrary angle with respect to the cavity. Mold for molding described. 3. The molding die according to claim 1, wherein the heat insulating material is made of resin. 4. A groove for a temperature control water circuit is formed on an anti-cavity surface of a cavity member, a portion of which constitutes the wall surface of the cavity, and the groove is filled with a filling material to be embedded. By attaching the cavity member to the mold body, positioning so that a space is formed between the anti-cavity surface of the cavity member and the mold body, and further pouring a liquid resin into the space to cure the resin. After forming the heat insulating material, the entire mold is heated, and the filling material filled in the groove of the cavity member is melted and flown out, whereby the temperature control circuit is provided near the wall surface of the cavity of the cavity member. A method for producing a molding die, which comprises producing a die provided with. 5. The method of manufacturing a molding die according to claim 4, wherein the filler is wax. 6. The method of manufacturing a molding die according to claim 4, wherein the resin is an epoxy resin.