JPH08150437A - Production of die with permeability having heating, cooling hole and die with permeability - Google Patents

Abstract

PURPOSE: To stably and in-expensively supply a die with the permeability being able to be heated or cooled by machining a cavity face of porous die blank that the clearance between a metal tube and a metal container is filled with a metal powder and chilled internally, into a prescribed shape. CONSTITUTION: A temperature regulating tube 2 which is made in a prescribed shape is assembled at a prescribed position inside a metal container 12 having a similar shape to a die 1. A rapid quench aluminum alloy powder 14 is filled in the clearance between the vessel 12 and the tube 2. A cap 15 is welded on the container 12 and the opening part 13 is sealed closely. Under the high temperature and the high pressure the powder 14 is compacted and solidified into a metal powder compacted body. The cavity face is executed with machining, etc., and it is machined into a die cavity 4. A heat transfer medium is made flow into the tube 2 and the die 1 is heated or cooled. The counter-measure to leaking of the heat transfer medium is made needless. Because the heat capacity of the aluminum alloy 14 is small, the heating or cooling time of the die 1 can be shortened.

Description

Detailed Description of the Invention

[0001]

[Industrial application] This relates to molding dies for metals and resins that require heating or cooling, especially with a relatively low molding pressure and air permeability. The present invention relates to a method of manufacturing an air-permeable mold having a heating / cooling hole which is repeated as described above and an air-permeable mold.

[0002]

2. Description of the Related Art In a conventional air-permeable low-pressure molding die, (1) on a die cavity surface that has been cast or machined,
Pores for ventilation were formed by drilling or electric discharge machining. (2) A metal porous body having air permeability is used as a mold material. (3) It was manufactured by forming a layer having air permeability on the mold cavity surface by electroforming or the like.

[0003]

However, in the case of (1) processing the pores on the surface of the mold cavity, the number and position of the pores are limited, so that uniform air permeability is provided over the entire surface of the mold cavity. Since it cannot be held, the quality of the molded product varies. Since the size of the pores is limited, it is not possible to process extremely small pores, so that the resin enters the pores and minute projections are formed on the surface of the molded product, resulting in deterioration of the quality of the molded product. Further, when the resin enters the pores, it causes clogging, which reduces the air permeability of the mold and shortens the life of the mold.

(2) In the case where the entire die is made of a metal porous body without forming a cast metal pipe, the temperature control medium passes from the heating / cooling holes through the holes in the porous body to the die cavity. To prevent the temperature control medium from leaking, in order to prevent leakage of the temperature control medium, if a means to form a non-permeable protective coating on the mold cavity surface is taken, the shape of the mold cavity surface should be modified or Repair processing is not possible. As another leak prevention measure, if a measure to form an impermeable protective film on the inner wall surface of the temperature control hole is taken after drilling the temperature control hole with a drill etc., linear temperature control hole processing such as drilling is performed. However, since it is not possible to perform processing along the mold cavity surface shape, the heating / cooling time becomes long, and it is also impossible to obtain a uniform temperature. Therefore, the molding cycle becomes long and the productivity is lowered.

(3) When the porous film is formed by the porous electroforming, a special device such as a porous electroforming process is required, which causes an increase in the cost of the mold. As in the case of using the metal porous body, it is impossible to perform processing such as repair, and in addition, a measure for preventing leakage of the temperature control medium is required. There were various problems.

The present invention has been made in view of the above problems of the prior art, and is a breathable mold having uniform breathability, light weight and high strength, and a heating / cooling hole with a short mold temperature control time. It is an object of the present invention to provide a method of manufacturing the same and a breathable mold.

[0007]

In order to achieve the above object, according to a first aspect of the present invention, a metal pipe processed into a predetermined shape is assembled in a metal container similar to a mold, and then the metal pipe is assembled. And a metal powder filled in a gap between the metal container and the metal pipe having a heating or cooling medium passage hole under high temperature and high pressure conditions. After obtaining the mold material, the cavity surface of the porous mold material is processed into a predetermined shape, and in the second invention, the surface modification treatment is performed on the metal powder, and then the surface of the metal powder is processed. An adjustment process capable of partially removing the oxide film is provided. Further, in the third invention, a mold is used in which the metal powder is a rapidly solidified aluminum alloy powder having a particle size distribution of 44 to 149 μm and a solidification rate of 10 ³ to 10 ⁶ ° C./sec and a small heat capacity.

[0008]

[Function] By integrally molding the metal powder forming the mold and the metal pipe forming the heating / cooling hole under the conditions of high temperature and high pressure, the entire surface of the mold cavity is uniformly breathable and has a high temperature. At the same time, a breathable mold can be obtained with no leakage of the preparation medium.

Further, the mold material, which has a great influence on the mold temperature control time, has a large effect on the heat capacity rather than being determined only by the conventionally considered temperature diffusion coefficient, and is made of an aluminum alloy having a small heat capacity. It is possible to obtain an air-permeable mold capable of controlling the mold temperature with good heating / cooling efficiency. Furthermore, by using the rapidly solidified aluminum alloy powder for the die base material, it is possible to obtain a lightweight molding die having high strength and high toughness and air permeability.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a breathable mold having heating / cooling holes and a concrete example of the breathable mold according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing the relationship between mold material and mold temperature control time,
FIG. 2 shows a cross-sectional view of a breathable mold molded under the conditions of high temperature and high pressure.

First, the present inventor has already considered that the heat capacity (specific heat × density) rather than the conventional idea that the mold temperature control time is shortened by using a material having a large temperature diffusion coefficient for the molding die 1. We have obtained the knowledge that it is appropriate to shorten the mold temperature control time by selecting the mold material depending on the size.

That is, assuming a perfect ideal state in which the laminar boundary film of the heat medium flowing through the conventional temperature control pipe 2 is completely absent, the heat cycle of the molding die 1 is a temperature diffusion coefficient [die. Thermal conductivity / heat capacity (specific heat × density)] is dominant. Therefore, the larger the temperature diffusion coefficient of the mold is, the shorter the mold temperature control time is, but the present inventor considers that the heat medium is a completely turbulent region, but the laminar boundary film It is confirmed that the heat capacity is more dominant in the heat cycle of the molding die 1 under such a semi-ideal state, because the heat capacity is more dominant.

Therefore, in this embodiment, the molding die 1 is used.
An aluminum alloy having a small heat capacity was used as the material. Incidentally, the heat capacity of the aluminum alloy (Al), copper alloy (Cu), and iron alloy (Fe) used for the material of the molding die 1 is Al <Cu <Fe,
Among them, the heat capacity of the aluminum alloy (Al) is the smallest, and conversely, the iron alloy (Fe) is the largest. Further, when comparing only the temperature diffusion coefficient, Fe <Al <Cu, and the copper alloy is the largest.

Further, as shown in FIG. 1, it has been confirmed that the molding die 1 can be heated and cooled in a short heat cycle by using the aluminum alloy having the smallest heat capacity. The results are that aluminum alloy <copper alloy <iron-based alloy becomes smaller and the mold temperature control time becomes shorter.

Based on the above results, in the present embodiment, the material of the molding die 1 is basically made of aluminum alloy having a small heat capacity.

In addition to this, in the present embodiment, as shown in FIG. 2, as a molding method of the molding die 1, the temperature control pipe 2 is incorporated into a predetermined position of a metal container similar to the mold 1 to form a metal container. Aluminum alloy powder 14 in the gap between the temperature control pipes 2
To fill. Specifically, a rapidly solidified aluminum alloy powder 14 having a particle size of 44 to 149 μm and a solidification rate of 10 ³ to 10 ⁶ ° C./sec is used, and this is filled with, for example, an apparent density of 80% or more in a metal container, Mold and solidify under high temperature and high pressure conditions.

In this way, after the temperature control pipe 2, the metal container and the aluminum alloy powder 14 are integrally molded and solidified,
With only the metal container 12 on the surface of the mold cavity 4 removed and the other part of the metal container 12 left, the mold 1 having a predetermined shape is finished by, for example, machining.

As a result, the surface of the mold cavity 4 has air permeability, the side of the mold opposite to the surface of the cavity 4 is sealed with the metal container 12, and the side surface of the metal container 12 is connected to the connecting jig. By attaching 6 to the exhaust device 8, air remaining in the gap between the resin being molded and the mold 1 is sucked from the surface of the mold cavity 4 and vented through the porous base material portion. It is possible to obtain a breathable mold 1.

Here, when the aluminum alloy powder 14 is filled, the air permeability after molding and solidification is affected,
It is desirable to fill the metal container 12 with an apparently high density in order to secure strength as the mold 1 and to minimize dimensional deformation due to solidification shrinkage. The effect increases when filled. Alternatively, it is also possible to pre-form and solidify under conditions of room temperature and high pressure and then fill the metal container.

On the surface of the aluminum alloy powder, an oxide film (such as Al2O3) formed during solidification is in the range of several tens to several.
It exists in a thickness of several hundred Å, and this oxide film hinders the bonding between powders when they solidify under high temperature and high pressure conditions.

That is, the metal powder compact molded and solidified by utilizing this inhibition phenomenon becomes a porous material in which extremely fine and continuous pores are uniformly dispersed in the entire area of the mold 1, and It is possible to obtain the mold 1 having extremely good air permeability.

Furthermore, by using the powder in which the oxide film on the surface of the powder is partially removed by the surface modification treatment, it is possible to increase the bonding strength between the metal powders and to have fine ventilation holes.

Furthermore, by adjusting the rate of partial removal of the surface oxide film according to the degree of surface modification treatment, the mold strength and air permeability, the size of the air holes, and the distribution state of the air holes can be freely set. You can control.

Further, when the metal container filled with the aluminum alloy powder 14 is molded and solidified under high temperature and high pressure conditions,
Since the dimensional shrinkage is involved when the powder state is changed to the solid state, it is necessary to calculate the size of the metal container according to the shrinkage amount in advance. Moreover, since the processing temperature of high temperature and high pressure in the case of the aluminum alloy powder used in this embodiment is relatively low, for example, 500 to 600 ° C., the metal container is not required to be a special material in this embodiment. An SS material that is easy and inexpensive to process is used.

During high temperature / high pressure molding, the temperature control pipe 2 is projected to the outside of the metal container so that, for example, N2 gas used under high pressure conditions is also conducted into the temperature control pipe 2, so that temperature control is performed. Although the adjustment pipe 2 was slightly deformed and moved with the solidification shrinkage of the aluminum alloy powder 14, the adjustment pipe 2 had a sufficient function as a heating / cooling medium passage hole.

Further, in the present invention, the rapid solidification characteristics are utilized by adjusting the composition of the aluminum alloy powder according to the diversifying characteristics of the molding die.
It is possible to obtain the characteristics equivalent to those of the iron-based alloy by solid-solubilizing an element effective for improving mechanical properties by rapid solidification, and in the present embodiment, the following two types of rapidly solidified aluminum alloy powders are shown. Was used.

The rapid solidification characteristic is obtained by increasing the solidification rate from the liquid state to the solid state.
To this end, the powder particle size is set to 44 to 149 μm from the viewpoint that reducing the powder particle size is effective. That is, a powder having a particle size of 44 μm or less has a solidification rate sufficient to obtain a rapid solidification property, but it is not preferable because the activation is strong and a danger such as an explosion is involved in handling.
This is because the powder of 49 μm or more has a slow solidification rate and does not maintain the rapid solidification property. Together with the powder production, 44
This is because the powder particle size distribution of ˜149 μm has the highest yield.

The solidification rate is 10 ³ to 10 ⁶ ° C / se
c. This has a strong relationship with the powder particle size determined previously, that is, it is difficult to dissolve the effective element into supersaturation at 10 ³ ° C / sec or less, and conversely, at 10 ⁶ ° C / sec or more, the rapid solidification characteristics rapidly increase. This is because there is no significant change. At the same time, by using a gas atomizing method which is relatively inexpensive as a powder manufacturing method and is generally used for industrial production, cost reduction can be achieved, and the solidification rate in this case is 10 ³ to 10 ⁶
It means that the temperature was satisfied with ° C / sec.

FIG. 2 shows a sectional view of the molding die obtained in the example according to the present invention. In FIG. 2, reference numeral 1 is a molding die, 2 is a temperature control pipe, 12 is a metal container, 13 is an opening, 14 is an aluminum alloy powder, and 15 is a lid.

Next, a method of manufacturing this molding die will be described.

First, as shown in FIG. 2A, a temperature control pipe 2 processed into a predetermined shape is used as a metal container 12 similar to a mold.
Install it in the specified position. Next, the rapidly solidified aluminum alloy powder 14 is filled into the gap between the metal container 12 and the temperature control pipe 2 through the opening 13 opened in the metal container 12. In addition,
At the time of filling the aluminum alloy powder 14, the opening 13 is made to be the upper surface, and when the filling is completed, the lid 15 is closed and sealed with the metal container 12 by, for example, welding.

Similarly, the temperature control pipe 2 and the metal container 12 are also sealed by welding or the like. Here, the temperature control pipe 2 has a structure projecting to the outside of the metal container 12, so that when the temperature control pipe 2 is molded and solidified under high temperature and high pressure conditions, for example, N2 for increasing the pressure into the temperature control pipe 2, An inert gas such as Ar is conducted so that the temperature control pipe 2 is not damaged. In this way, each metal container 12 is put into an apparatus capable of high-temperature and high-pressure condition treatment and integrally formed and solidified.

Here, the treatment conditions are the residual ratio of air-permeable fine pores after molding and solidification, the rapidly solidified aluminum alloy powder 14, the temperature control pipe 2 or the metal container 1.
Set according to the material of 2.

The remaining rate of fine pores can be adjusted by previously subjecting the metal powder to a surface modification treatment, and it has been confirmed that the influence of the treatment conditions at the time of molding and solidification is reduced. Is. That is, if the temperature and pressure at the time of molding and solidification are set in advance so as to obtain a desired porous body, the residual rate of fine pores and the like are determined by the surface modification treatment before molding and solidification.

In this embodiment, as shown in FIG.
The temperature was 500 ° C. and the pressure was 1,000 kg / cm ² .
After being processed under high temperature and high pressure conditions and integrally molded, the metal mold cavity 4 surface is processed into a predetermined shape while leaving the metal container 12 other than the metal mold cavity 4 surface.
The gas permeable mold 1 is obtained through the connecting jig 6 on the side surface of the metal container 12 other than the surface.

Using the breathable mold 1 thus obtained,
A molding test was conducted and the results shown in Table 1 were obtained.

[0038]

[Table 1]

As is clear from Table 1, the superiority of the molding die 1 of this example was proved in all points when the comparative example was used as a reference. Each mold has a width of 300 x
A cooler box mold for molding a cooler box for leisure with a length of 400 mm and a thickness of 40 mm, and a temperature control pipe 2
Was formed by casting stainless steel having an outer diameter of 12 mm and a thickness of 1.5 mm in the examples, and the comparative example was machined (drilled) to have an inner diameter of 9 mm.

Example 1: Breathable mold obtained by molding and solidifying rapidly solidified aluminum alloy powder (Al-Fe system) under conditions of high temperature and high pressure Example 2: Rapidly solidified aluminum alloy powder (7091)
System) was molded and solidified under high temperature and high pressure conditions. Comparative example: A mold obtained by machining an aluminum rolled material for a mold, and a ventilation hole having a diameter of 0.3 mm was drilled. Indicates. Here, a material selected in Example 1 was heat resistance, a material in Example 2 was high strength, and a material frequently used in the comparative examples was selected.

As shown in Table 1, even in the mold temperature control time, a metal pipe for temperature control is used as the heat medium passage so as to be arranged along the shape of the mold cavity 4. It was possible to obtain a fairly short mold temperature control time. In addition, the quality of the molded product is significantly improved as compared with the comparative example because the uniform and fine air vents are uniformly dispersed and arranged over the entire area of the mold 1. Further, since the air vents are extremely fine, the resin is It was confirmed that the plugging did not cause clogging at all.

Further, due to the rapid solidification property, the physical properties are much higher than those of the comparative examples even at room temperature and 200 ° C. tensile strength, which is the normal temperature range for mold forming, and it is possible to cope with diversifying mold use conditions. is there.

In this example, the rapidly solidified aluminum alloy powder was used for the purpose of expanding the use of the mold, but a normal solidified aluminum alloy powder can be used in the low pressure molding mold having relatively small stress. Therefore, the cost can be reduced.

[0044]

As is apparent from the above description, in the first invention according to the present invention, a metal pipe processed into a predetermined shape is assembled in a metal container similar to a mold, and then the metal pipe is used. Porous gold having air permeability by being filled with metal powder in the gaps between the metal containers and integrally molding the metal pipe having heating or cooling medium passage holes inside the mold under high temperature and high pressure conditions. After the mold material is obtained, the cavity surface of the porous mold material is processed into a predetermined shape, so that it has a very fine ventilation hole, so that a high quality molded product can be stably obtained. it can. By forming a metal pipe around the porous body as a heat medium passage hole, it is not necessary to take measures against leakage of the heat medium, and it is possible to stably supply a breathable mold that can be heated and cooled at low cost. be able to.

According to the second aspect of the present invention, after the metal powder is subjected to the surface modification treatment, an adjusting step capable of partially removing the surface oxide film of the metal powder is provided. Since the size, distribution, etc. can be adjusted, a high quality breathable mold can be stably supplied.

Further, in the third invention, the particle size is added to the metal powder.
Cloth 44-149 μm, coagulation rate 10 ³-10⁶℃ / se
Uses rapidly solidified aluminum alloy powder with small heat capacity of c
As a result, a die material with high strength and high toughness can be obtained.
Therefore, we supply molds that are compatible with diversifying molding dies.
Can also be aluminum with a small heat capacity
By using an alloy, the heating / cooling time of the mold can be shortened.
It

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the mold material of the present invention and the mold temperature control time.

FIG. 2 is a cross-sectional view of a breathable mold molded under conditions of high temperature and high pressure. FIG. 2 (1) shows a case where an exhaust device is not installed, and FIG. 2 (2) shows an exhaust device installed. Each case is shown.

[Explanation of symbols]

 1 Mold for molding (breathable mold) 2 Pipe for temperature control 4 Mold cavity 6 Connection jig 8 Exhaust device 12 Metal container 13 Opening 14 Aluminum alloy powder 15 Lid

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B22F 1/00 N 1/02 F 3/11 B29C 33/02 9543-4F 33/10 9543-4F 33/38 9543-4F 45/73 7639-4F

Claims (3)

[Claims] 1. A metal pipe processed into a predetermined shape is assembled in a metal container similar to a mold, and then a metal powder is filled in a gap between the metal pipe and the metal container and heated under high temperature and high pressure conditions. Alternatively, after the metal pipe having a cooling medium passage hole is cast inside the mold to be integrally molded to obtain a porous mold material having air permeability, the cavity surface of the porous mold material is processed into a predetermined shape. A method for producing a breathable mold having heating / cooling holes. 2. A heating / cooling hole comprising an adjusting step capable of partially removing a surface oxide film of the metal powder after the surface modification treatment of the metal powder according to claim 1. A method of manufacturing a breathable mold having the same. 3. The particle size distribution of the metal powder according to claim 1 is 44 to 1.
A breathable mold having heating and cooling holes, which is characterized by using a rapidly solidified aluminum alloy powder having a small heat capacity of 49 μm and a solidification rate of 10 ³ to 10 ⁶ ° C./sec.