JPH09314611A - Easily temperature controllable mold structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently raise and lower the temperature of a mold in the short period of time and shorten the molding preparatory working time by a method wherein a cavity is made into an inserting piece system by forming a main mold and the cavity in separate part for efficiently realizing the controlling the temperature of the molds. SOLUTION: Between the mating surfaces of a fixed side main mold 1 and of a movable side main body 2, a cavity 3 is formed and comprises a fixed side inserting piece 4 and a movable side inserting piece 5. Heat insulating layers are respectively provided between the fixed side main mold 1 and the inserting piece 4 and between the movable side main mold 2 and the inserting piece 5. The heat insulating layer comprises a low conductive stainless steel heat insulating layer 6 and a bakelite heat insulating plate 7. Gaps 8 are provided between the fixed side main mold 1 and the stainless steel 6 and the movable side main mold 2 and the stainless steel 6. Gaps 9 are provided between the fixed side inserting piece 4 and the heat insulating plate 7 and between the movable side inserting piece 5 and the heat insulating plate 7. Furthermore, a mold temperature controlling piping 10 and a thermocouple 11 are provided in the fixed side inserting piece 4 and the movable side inserting piece 5 for controlling the temperature of the molds.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a molding method such as general injection molding and gas assist molding of a thermoplastic resin.
The present invention relates to a mold structure applicable to a molding method in a field in which high quality surfaces and dimensional accuracy are required for molded products such as exterior parts, outer plates and precision parts of various products and high cycle is required.

The present invention is particularly applicable to a high cycle when a mold temperature is raised to eliminate appearance defects such as weld lines and jetting of various molded products, dimensional accuracy defects, and appearance defects in inorganic filler-filled materials. The present invention relates to a molding die structure.

[0003]

2. Description of the Related Art Conventionally, in the molding of engineering plastics, the mold temperature is lower than the heat distortion temperature of the resin by the problem of molding residual stress and appearance of the molded product and the problem of floating of the filler in the resin filled with the inorganic filler. In many cases, the temperature was set lower by about 20 ° C. However, there are problems that it takes too much time to raise and lower the temperature of the die, the die temperature exceeding 100 ° C. does not rise, and the molding cycle becomes long.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a mold for conventional injection molding, gas assist molding, etc., which is effective for shortening the molding cycle and is capable of efficiently controlling the temperature of temperature rising and cooling of the mold in a short time. An object of the present invention is to provide a molding die structure that can be formed inside.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an injection mold with a main mold and a cavity for forming a product shape as separate parts in order to efficiently control the mold temperature. This is solved by a mold structure in which the cavity is of the insert piece type.

In this mold structure, a heat insulating layer can be provided between the main mold and the insert piece. As the heat insulating layer, a metal material having a thermal conductivity of 30 W / mK or less, for example, a metal such as stainless steel or titanium is provided between the main mold and the insert piece, and between the metal having a poor thermal conductivity and the insert piece. A double-layered heat insulating layer can be formed by installing a heat insulating plate, for example, Bakelite.

By using the mold structure according to the present invention, molding suitable for automobile parts such as roof rails, door handles and grips for vehicles, office equipment such as FAX and copying machines, housings and chassis for household electric appliances, etc. Goods are obtained. This mold can be applied to various molding methods such as injection molding of thermoplastic resin and gas assist molding having a hollow molding portion.

As described above, the mold structure for efficiently and rapidly raising and lowering the temperature used in the present invention has the main mold forming the outer mold of the mold, the cavity forming the product shape, and the core. Is a separate part, and both of them are of the insertion piece type.

Here, between the main mold and the insert piece,
A heat insulating layer consisting of a double structure of a metal material with a thermal conductivity of 30 W / mK or less and a heat insulating plate is installed, and the mold strength is maintained on the contact surface between the main mold and the heat insulating layer and the contact surface between the insert piece and the heat insulating plate. This can be achieved by providing voids within a range that does not cause a problem.

At this time, the metal forming the insert piece is a material having a thermal conductivity of 60 W / mK or more, such as zinc, Be-Cu (beryllium-copper), aluminum and alloys containing these as the main components, and pre-hardened steel. create. Further, the mold temperature control pipe is directly provided in the insert piece portion, and the temperature is controlled only in the insert piece portion.

[0011]

According to the present invention, the temperature of the mold can be raised and lowered efficiently and quickly, and the time required for work preparation can be shortened. Further, a mold temperature of 100 ° C. or higher can be easily realized in a short time.

According to the present invention, in the mold cooling / heating cycle in which the mold temperature is raised and lowered during one molding cycle,
It can be realized without lengthening the molding cycle.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be disclosed in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 is a sectional view of a mold structure according to the present invention. In this mold, a cavity 3 is formed on the mating surface of the fixed main mold 1 and the movable main mold 2. The cavity 3 is formed by a fixed insertion piece 4 and a movable insertion piece 5.

A heat insulating layer is provided between the fixed main mold 1 and the insert piece 4, and between the movable main mold 2 and the insert piece 5, respectively. This heat insulating layer is composed of a stainless steel heat insulating layer 6 which is a metal having a low thermal conductivity and a bakelite heat insulating plate 7.

A gap 8 is provided between the fixed-side main mold 1 and the movable-side main mold 2 and the stainless steel 6 within a range where there is no problem in terms of mold strength. In addition, the fixed insertion piece 4 and the movable insertion piece 5
Between the heat insulating plate 7 and the heat insulating plate 7 within a range where there is no problem in mold strength.
Is provided.

A mold temperature control conduit 10 and a thermocouple 11 are provided on the fixed side insert piece 4 (not shown) and the movable side insert piece 5 in order to control the temperature of the die.

Example 1 In Example 1, a temperature controller TURBU-TD-U4-H (manufactured by Cisco Co., Ltd.) was used, and hot water pressurized at 100 ° C. was 1200 l /
The mold of the present invention is circulated in hr, the temperature of the mold surface temperature is measured, and the mold cooler Glacier series portable chiller NXGW-10 (manufactured by Cisco Corp.)
The mold of the present invention was circulated at 000 l / hr and the rate of temperature decrease of the mold surface temperature was measured. As a comparative example, the same experiment was performed with the same mold without the insert piece structure, and the comparison was made.

The heating rate of the present invention is 30 times that of the comparative example, and the cooling rate of the present invention is 2 times that of the comparative example.
The speed was 0 times. The results are shown in Table 1.

[0019]

[Table 1]

Example 2 In Example 2, a temperature controller TURBU-TD-U4-H (manufactured by Cisco Co., Ltd.) was used, and hot water pressurized at 140 ° C. was 1200 l / l.
The mold of the present invention was circulated in hr and the mold surface temperature was evaluated. As a comparative example, the same experiment was carried out in the case where the same mold was used and the insert piece structure was not used, and the results were compared.

According to the mold of the present invention, after the hot water patrol is started, 3
After a minute, the surface temperature of the cavity reached 140 ° C., whereas in the comparative example, it was 100 ° C. one hour after the start of the hot water circulation. Table 2 shows the results of the mold surface temperature of Example 2.

[0022]

[Table 2]

[0023]

According to the present invention, it is possible to efficiently raise and lower the temperature of the mold in a short time, and it is possible to shorten the working time for the molding preparation. Further, the mold temperature of 100 ° C. or higher can be surely kept at the set temperature. As a result, high cycle molding becomes possible.

[Brief description of drawings]

FIG. 1 is a sectional view of a mold structure according to the present invention.

[Explanation of symbols]

 1 Fixed-side main mold 2 Movable-side main mold 3 Cavity 4 Fixed-side insert piece 5 Movable-side insert piece 6 Insulation layer (stainless steel) 7 Insulation plate 8 Void between main mold and insulation layer 9 Insert piece and insulation plate Air gap 10 Mold temperature control pipe 11 Thermocouple

Claims (9)

[Claims] 1. In an injection molding die, a main die and a cavity for forming a product shape are formed as separate parts in order to efficiently control the die temperature, and the cavity is made into an insert piece type. The mold structure is characterized by easy temperature control. 2. The mold structure according to claim 1, wherein a heat insulating layer is provided between the main mold and the insert piece. 3. A thermal conductivity of 30 between the main mold and the insert piece.
A double layer heat insulating layer formed by providing a heat insulating layer made of a metal material of W / m · K or less and installing a heat insulating plate made of an appropriate material between the metal having poor thermal conductivity and the insert piece. The mold structure according to claim 1 or 2, further comprising: 4. The mold structure according to claim 1, wherein a void is provided in a contact surface between the main mold and the heat insulating layer within a range where there is no problem in mold strength. . 5. The contact surface between the heat insulating plate and the insert piece,
The mold structure according to any one of claims 1 to 4, wherein voids are provided in a range where there is no problem in mold strength. 6. The mold temperature control conduit for controlling the mold temperature is provided independently from the insert piece and provided in a large number within a range in which there is no problem in mold strength. 5
The mold structure according to any one of 1. 7. The mold structure according to claim 1, wherein the metal forming the insert piece is made of a material having a thermal conductivity of 60 W / m · K or more. 8. The thermal conductivity of the insert piece is 60 W /
The mold structure according to claim 7, wherein the metal material having m · K or more is any one of zinc, Be-Cu (beryllium-copper), aluminum, an alloy containing these as main components, and pre-hardened steel. . 9. The mold structure according to claim 1, wherein the mold temperature control pipe is directly provided in a receiving piece portion forming a cavity.