JPH06297463A - Mold attachment - Google Patents

Abstract

PURPOSE:To enhance forming efficiency and product yield and realize low cost by a method wherein piping for supplying heating and cooling medium is arranged under the condition that the space is left between the rear surface of a mold and the piping and, in addition, nozzle holes, through which heating and cooling medium is radiated against the back of the mold, are formed on the piping. CONSTITUTION:After molding material W is charged in a product molding part 4, which is between both the upper mold 2 and the lower mold 3 of a molding device 1, heating medium is supplied from medium supplying source to respective pipings arranged on the rear surface 3a side of the lower mold. The heating medium supplied in the pipings 10 is radiated as mist from respective nozzle holes 11 against the rear surface 3a of the lower mold. Since the pipings 10 do not contact the lower mold 3, the heat exchange between the heating medium in the pipings 10 and the outside is small and the temperature change of the heating medium in the pipings 10 is small. Accordingly, the heating medium having nearly uniform temperature is radiated so as to allow to heat uniformly the whole lower mold 3. The heating medium, the heat of which is dissipated to the rear surface 3a of the lower mold, changes heat directly to the lower mold 3, resulting in thermally hardening the molding material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die attachment device for heating or cooling a molding die from the back surface thereof in a molding device for filling a molding material between a pair of molding dies and molding it into a predetermined shape.

[0002]

2. Description of the Related Art For example, when a thermosetting resin is used as a molding material and a product is molded by injection molding, after the molding material is filled in the molding die, the molding material is heated to cure the molding material. Then the product is molded. On the other hand, when a heat-melting synthetic resin is used as a molding material, the molding material is filled in a heated molding die, and then the molding material is cooled to cure the molding material to mold the product.
As described above, the molding apparatus using the molding die often requires heating or cooling of the molding die.

In view of this, some conventional molding apparatuses have molding die attachment devices 20, 21 as shown in FIG. 5 or FIG. These mold attachment devices 20, 21
Is attached to a molding device 24 configured to fill a molding material W between a synthetic resin upper mold 22 and an aluminum alloy lower mold 23 to mold a product, and has high thermal conductivity. By heating or cooling the lower die 23, the molding material W filled in the molding die is cured. That is, the conventional mold attachment device 20 shown in FIG.
The rear part of 3 has a hollow portion 25.
A heating / cooling medium is introduced into the inside to heat or cool the entire lower die 23. On the other hand, in the conventional mold attachment device 21 shown in FIG. 6, a metal pipe 26 is welded to the back surface of the lower mold 23, and a heating / cooling medium is circulated in the pipe 26, and the metal pipe 26 is passed through the pipe 26. Heating / cooling medium and lower mold 2
The heat exchange with 3 was performed.

[0004]

In the conventional molding die attachment device 20 shown in FIG. 5, since the hollow portion 25 formed in the back portion of the lower die 23 has a large volume, the inside of the hollow portion 25 is uniformly heated.・ To distribute the cooling medium, a large amount of heating
A cooling medium was required, and a pressure feed pump (not shown) for supplying the heating / cooling medium was also large and had a large pressure. Therefore, there is a problem that the equipment and operation costs are high. Further, since the conventional mold attachment device 21 shown in FIG. 6 uses heat exchange through the pipe 26, the heating or cooling efficiency is poor. Therefore, in order to sufficiently cure the molding material, it is necessary to keep the heating / cooling medium in conduction for a long time, which causes a problem of poor molding efficiency.
Moreover, since heat is exchanged between the heating / cooling medium in the pipe 26 and the lower mold 23, the temperature of the heating / cooling medium in the pipe 26 changes, and the heating / cooling state of the lower mold 23 is changed. Partially uneven. Therefore, the curing time of the molding material is partially different, and as a result, there is a risk of product quality defects such as cracks and cracks in the product, and partial loss of gloss on the surface of the product. It was the cause. The present invention has been made in order to solve the problems of the prior art as described above, and provides a mold attachment device that can heat or cool a mold efficiently and inexpensively with equipment and operating costs. With the goal.

[0005]

In order to achieve the above-mentioned object, the present invention is attached to a molding apparatus for filling a molding material between a pair of molding dies and molding it into a predetermined shape. A mold attachment device that heats or cools at least one of the molds, and a pipe for supplying a heating / cooling medium is installed from the back of the mold at an arbitrary interval, and heating / cooling supplied in the pipe. A plurality of nozzle holes for discharging the medium toward the back surface of the molding die are formed in the pipe.

[0006]

In the apparatus of the present invention having the above-mentioned structure, the heating / cooling medium supplied into the pipe is diffused to the back surface of the molding die through the nozzle holes. The medium supply pressure required at this time is the sum of the pressure for supplying the heating / cooling medium into the pipe with a small volume, and the pressure for allowing the heating / cooling medium diffused from the nozzle holes to reach the back surface of the mold. Is. Since such a supply pressure requires a comparatively small pressure, a small pressure pump can suffice. Further, since the heating / cooling medium diffused from the nozzle holes directly contacts the back surface of the molding die, the molding die can be efficiently heated or cooled. further,
Since there is no heat exchange with the mold in the pipe, the heating / cooling medium diffused from each nozzle hole has a substantially constant temperature, and the entire surface of the mold can be uniformly heated or cooled.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 4 are views showing an embodiment of the present invention, FIG. 1 is a front sectional view of a molding apparatus provided with a molding die attachment device of the present invention, and FIG. 2 is a lower mold rear surface portion of the molding apparatus. It is a bottom view. As shown in FIG. 1, the molding apparatus 1 includes an upper mold 2 and a lower mold 3, and a space serving as a product molding unit 4 is formed between the molds 2 and 3. The upper mold 2 is made of a heat-resistant synthetic resin, while the lower mold 3 is made of an aluminum alloy having good thermal conductivity. In this embodiment, the lower mold 3 is heated from the back surface to cure the thermosetting molding material W filled in the product molding unit 4.

On the rear surface 3a side of the lower mold 3, a plurality of heating medium supply pipes (hereinafter, simply referred to as "pipes") 10 are installed at arbitrary intervals from the lower mold rear surface 3a. Here, if the lower die back surface 3a and the pipe 10 are too close to each other, the range of the heating medium diffused from the nozzle holes 11 to be described later becomes narrow, while if they are too far, the heating medium diffused from the nozzle holes 11 is Since it is cooled in the air, the distance between the lower mold back surface 3a and the pipe 10 is determined with these points in mind. The pipe 10 can be formed of various heat-resistant materials, but preferably the pipe 1 is made of a material having a small thermal conductivity.
The temperature change of the heating medium within 0 is reduced. As shown in FIG. 2, these pipes 10 are provided almost uniformly over the entire rear surface 3a of the lower mold 3. Both ends of each pipe 10 communicate with a medium supply source (not shown), and the heating medium is supplied from the medium supply source by a pressure feed pump (not shown). The heating medium to be supplied is arbitrarily selected in consideration of the curing temperature of the molding material W. For example, if the molding material W is a thermosetting resin having a curing temperature of 80 ° C., hot water heated to nearly 90 ° C. may be selected as the heating medium.

Each of the pipes 10 is provided with a plurality of nozzle holes 11 as shown enlarged in FIGS. Each nozzle hole 11 is arranged so as to diffuse the heating medium S toward the lower die back surface 3a. Further, the nozzle hole 11 is formed in an arbitrary shape that can dissipate the heating medium S in the form of mist. Here, the nozzle hole 11 is composed of two types of nozzle holes 11a and 11b having different medium ejection directions.
Are arranged alternately along the axial direction. By thus alternately arranging the nozzle holes 11a and 11b having different medium discharge directions, the range in which the heating medium S can be diffused from the single pipe 10 is widened. As a result, a small number of installed pipes 10
The heating medium S can be diffused over the entire lower mold 3.
The lower die back surface 3a is formed as a rough surface as shown in FIG. By thus forming the lower mold back surface 3a as a rough surface, the surface area of the back surface 3a, that is, the area in contact with the heating medium is expanded, and the heat exchange efficiency is further improved. The roughness of the rough surface may be arbitrary. The base 5 supporting the lower mold 3 is provided with a drainage port 6, and the heating medium that has been diffused to the lower mold back surface 3a and then dropped is discharged to the outside of the apparatus through the drainage port 6.

Next, the operation of the molding die attachment device described above will be described. As shown in FIG. 1, after closing the upper mold 2 and the lower mold 3 of the molding apparatus 1 and filling the molding material W into the product molding portion 4 formed between the molds 2 and 3, the lower mold rear surface 3a. A heating medium is supplied from a medium supply source (not shown) to each of the pipes 10 provided on the side. The heating medium supplied into the pipe 10 is used for each nozzle hole 1
1 to the lower mold back surface 3a in the form of mist (see FIG. 4).
reference). Here, since the pipe 10 is not in contact with the lower mold 3, heat exchange between the heating medium in the pipe 10 and the outside is small, and the temperature change of the heating medium in the pipe 10 is small. Therefore, the heating medium having a substantially uniform temperature is diffused from each nozzle hole 11, and the entire lower die 3 can be heated uniformly. The heating medium dissipated on the lower mold back surface 3a is
Since the heat exchange is directly performed between and, the molding material can be efficiently heat-cured.

The present invention is not limited to the above-described embodiments, but various modifications and applications are possible without departing from the spirit of the invention. For example, in the above-mentioned embodiment, the heating medium was supplied into the pipe for heating and curing the thermosetting molding material, but the present invention is not limited to this, and the heating medium or the cooling medium may be selected for the pipe according to the molding method. Just supply it. Further, the pipes can be installed not only on the back surface of the lower mold but also on the back surface of both the molding dies depending on the structure of the molding apparatus to be installed. Each nozzle hole formed in the pipe may be configured to discharge the heating / cooling medium in the same direction, or may be configured by a plurality of types of nozzle holes discharging the medium in different directions of three or more directions. .

[0012]

As described above, according to the molding die attachment device of the present invention, the heating / cooling medium supply pipe is installed at an arbitrary interval from the back surface of the molding die and the pipe is provided in the pipe. A plurality of nozzle holes that diffuse the supplied heating / cooling medium toward the back of the mold are formed in the pipe, so the equipment and operating costs are low, and the mold can be heated or cooled efficiently and uniformly. As a result, the molding efficiency and the product yield can be improved at low cost.

[Brief description of drawings]

FIG. 1 is a sectional front view of a molding apparatus equipped with a molding die attachment device according to an embodiment of the present invention.

FIG. 2 is a bottom view showing a back surface of a lower mold of the molding apparatus.

FIG. 3 is an enlarged perspective view showing a pipe.

FIG. 4 is a cross-sectional side view showing an enlarged lower mold rear surface and piping.

FIG. 5 is a sectional front view showing a conventional example.

FIG. 6 is a sectional front view showing another conventional example.

[Explanation of symbols]

 2 Upper mold 3 Lower mold 4 Product molding part 5 Base 6 Water distribution port 10 Piping 11 Nozzle hole

Claims (2)

[Claims] 1. A molding die attachment device, which is attached to a molding device for filling a molding material between a pair of molding dies to mold into a predetermined shape, and which heats or cools at least one of the pair of molding dies. A heating / cooling medium supply pipe is installed at an arbitrary distance from the back surface of the mold, and a plurality of nozzle holes for discharging the heating / cooling medium supplied into the pipe toward the back surface of the molding die are provided. A molding die attachment device formed on the pipe. 2. The plurality of nozzle holes are composed of at least two types of nozzle holes having different circumferential opening directions,
The molding die attachment device according to claim 1, wherein the nozzle holes are alternately arranged along the axial direction.