JPS62240137A - Production of mold for forming product by molten metal drop - Google Patents

Abstract

PURPOSE:To simply produce a mold for forming product having excellent heat conductivity of the surface at short time by projecting molten metal drops under inert gas atmosphere on a model surface, and to separating molten metal drop sticking layer, formed on the surface from the above-mentioned model. CONSTITUTION:Metal bar 16 for the molten drop forming is sent in inner part of a nozzle 11 and become to the molten drops by arc generated between electrodes 12, 13 under the inert gas atmosphere, such as Ar, etc., introducing from an injecting hole 14. The above-mentioned molten drops are projected continuously or intermittently on the surface of the model 17. On the surface of the above model 17, molten metal spraying layer having a few mu thickness is desirable to form previously. Further, Al or Al alloy, etc., as the material quality for the above metal bar, is suitable from a view-point of good thermal conductivity, etc. In this way, the molten metal drop sticking layer 18 is formed on the surface of the model 17 and separated from the model 17 to obtain the model for forming product, producing plastic forming product, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a mold for a molded product for manufacturing a plastic molded product, a casting, etc. (hereinafter referred to as a molded product), and more specifically, , a method of manufacturing molds for moldings particularly suitable for manufacturing small quantities of molded products, in which a mold for moldings is obtained by projecting droplets of metal such as aluminum onto the surface of the model. The present invention relates to a method for forming a mold for a molded article using droplets.

[Technical background of the invention]

A small number of molded products are generally manufactured using synthetic resin molds and the like. That is, a model obtained from a design drawing (including a model obtained by transferring a model obtained from a design drawing with plaster, etc.) is placed in a frame, and a synthetic resin is poured into the frame, and the synthetic resin is solidified. After that, a resin mold obtained by separating (peeling) the model is used, and a synthetic resin is poured into the mold to produce a molded product.

However, when molding a molded article using the resin mold described above, synthetic resin is poured into the mold, but since the surface of the resin mold has poor thermal conductivity, the resin does not flow uniformly throughout the mold. There are problems in that voids etc. are generated in some areas and the heat curing temperature is uneven, resulting in a high proportion of defective molded products.

Therefore, today, there are two types of configurations: ■ A configuration in which multiple number heaters are installed inside the mold, ■ A configuration in which a thin metal plate with excellent thermal conductivity is installed on the inside surface of the mold, and ■ A configuration in which a thin metal plate with excellent thermal conductivity is installed on the inside surface of the mold. Attempts have been made to use superior metals that are thermally sprayed.

However, although the configuration in which heaters are arranged in (■) can improve the thermal conductivity of the entire mold, it takes too much time to manufacture, and the configuration in which (■) in which a thin metal plate is installed is such that the thin metal plate has a shape that matches the mold. The cost for molding becomes high, and the metal sprayed structure (2) has problems such as a decrease in thermal conductivity because each of the metal spray particles is oxidized.

In addition, when using a casting mold suitable for molding a large amount of molded products, there is not much of a problem in terms of thermal conductivity as described above, but plaster molds or sand molds are required to obtain the mold. (
Since it is necessary to mold a ceramic mold in the middle, there are problems in that it takes many manufacturing steps to obtain the mold, takes a lot of manufacturing time, and requires a large amount of ceramic, etc. ing.

In order to solve the above-mentioned problems, the inventor of the present invention conducted various experiments and considerations, and found that a droplet-shaped metal with thermal conductivity, such as aluminum, was used in an inert gas atmosphere. It has been found that when the droplets are successively applied to various parts, the droplets are integrated to form a thick plate-like body. Further investigation into this matter revealed that the planar array of droplets was thermally contracted at the stage when each droplet was dropped, and the plate formed by the planar droplets was It was found that there was no need to worry about thermal contraction, and since each metal droplet was integrated with the next metal droplet without forming an oxide film, a plate-like body with excellent thermal conductivity could be obtained. Ta.

The present invention was created in response to the above-mentioned problems, and its purpose is to provide a molded product that can be manufactured easily in a short time and has an excellent surface thermal conductivity. The purpose is to provide a model.

[Means for solving problems]

As a means for achieving the above object, the method of manufacturing a mold for a molded article using metal droplets of the present invention is to continuously or intermittently apply droplet-shaped metal onto the surface of a model under an inert gas atmosphere. A configuration in which a metal droplet adhesion layer is formed on the surface by means of dropping or the like, and then the metal droplet adhesion layer is separated from the above model to obtain a mold for a molded article made of metal droplets. It becomes more.

Here, in the above structure, argon gas is normally used as the inert gas, and aluminum or aluminum alloy is used as the metal. The structure includes a thermally sprayed layer.

[Effect]

The method for manufacturing a mold for a molded article using metal droplets according to the present invention based on the above configuration is such that metal droplets are first projected onto the surface of a model for making a mold under an inert gas atmosphere.・If the metal droplet is projected before an oxide film is formed on the attached metal droplet, both droplet-formed metals will weld and solidify together, forming a metal droplet adhesion layer, and the metal droplet adhesion layer will be modeled. When separated further, the metal droplet adhering layer acts to form a mold for a molded article having uniform thermal conductivity.

〔Example〕

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. Here, FIG. 1 is a schematic diagram of a droplet projection device used to carry out the present invention, and FIG. 2.3 is a manufacturing process diagram showing an embodiment of the present invention.

As shown in FIG. 1, the method for manufacturing a mold for a molded article according to this embodiment includes a rod anode 12 at an upper position in the center inside a nozzle 11, a cathode 13 at a lower position, and The nozzle 11 has an inert gas injection port I4, and further has a droplet forming metal rod sending hole 15 between both electrodes of the nozzle 11, and the droplet forming hole 15 is sent out from the droplet forming metal rod sending hole 15. The metal rod 16 for use in the electrodes 12, 1 is placed under an inert gas atmosphere injected from the inert gas injection port 14.
The arc generated between 3 and 3
The metal droplet projection device 10 is used which is capable of dropping (projecting) the metal droplets onto the model 17. here,
As the metal rod for forming droplets, an aluminum alloy is used from the viewpoint of good thermal conductivity, and as the inert gas, agon gas is used. However, other types of materials may be used as required, for example, aluminum, copper, etc. may be used as the metal rod for forming droplets, and helium gas or the like may be used as the inert gas.

That is, an aluminum alloy is turned into droplets and projected onto the end surface of a model 17 of a molded product created from a design drawing using a metal droplet projection device 10 under an inert gas atmosphere. Then, by performing the same operation while moving the device 10 little by little, the previously ejected metal droplet and the next ejected metal droplet in a reduced state become integrated, and by performing this operation continuously, the droplet A metal droplet layer 18 is formed on the model surface with a thickness corresponding to the size of the metal droplet (see FIG. 2). Here, multiple layers may be formed, and a reinforcing layer made of resin or the like may be provided outside the layer.

Then, when the metal droplet layer 18 and the model 17 are separated, the metal droplet layer 18 itself has a thick mold 19.
(See Figure 3).

Next, in order to confirm the effect of the mold for molded products obtained in this example described above, 50 sheets of synthetic resin were each made using a nuclear mold and a conventional synthetic resin mold with a metal sprayed layer inside. After individually molding and examining the sheet and the mold after use,
The following was observed.

In the case of the mold for molded products according to this example, no irregularities were observed on the entire surface of all sheets, whereas in the case of the conventional synthetic resin mold, 20 sheets had large irregularities and were defective. The occurrence of This is thought to be due to the quality of the thermal conductivity of the mold surface, and also indicates that the thermal conductivity of the mold surface is maintained approximately uniform in the case of the mold for a molded article according to this example.

Further, in the case of the mold for a molded product of this example, no change was observed in the mold itself, whereas in the case of the synthetic resin mold of the conventional example, deformed parts were observed inside the mold. This is thought to be due to the quality of the strength, and in the case of the mold for a molded article according to this example, it is thought to be based on the fact that the metal forming the mold is reliably integrated and the metal is thick.

In the above-mentioned embodiment, when dropping droplets in succession, it is preferable to consider the position where the drops are dropped, as small gaps may be formed on the model surface between adjacent droplets. In such a case, the surface treatment may be performed by first spraying the same metal as the droplet onto the surface of the model to form a sprayed metal layer several microns thick. In this case, although the metal sprayed layer has poor thermal conductivity, the droplet layer disposed in contact with the metal sprayed layer acts to maintain good thermal conductivity. In the case of a mold for a molded article obtained with this configuration, a smooth mold surface was obtained.

In this example, metal droplet projection was carried out using a device as shown in FIG. 1, but the present invention is not limited to using such a device. It is clear that a mold for a molded article may be obtained by using a metal melting furnace and dropping the molten metal from the layer while shielding with a shielding gas such as argon gas, and making it adhere to the surface of the model.

Incidentally, the present invention is not limited to the above-described embodiments, but includes modifications that can be made without changing the gist of the present invention.

〔Effect of the invention〕

As is clear from the above description, according to the method of manufacturing a mold for a molded article using metal droplets of the present invention, metal droplets are dropped (projected) onto the surface of the model in an inert gas atmosphere, and the model surface is A metal droplet layer is formed on the metal droplet, and the mold is manufactured using the metal droplet, and the droplets that form the core mold do not form an oxide film, so the droplets are integrated with each other and have excellent thermal conductivity. This has the effect that a mold for a molded article can be easily obtained.

Furthermore, according to the method of manufacturing a mold for a molded article using metal droplets of the present invention, it is possible to manufacture the mold by directly projecting the metal forming the mold onto the surface of the model. , a ceramic mold, etc. are not required, so the manufacturing process can be shortened, and the mold can be obtained in a short time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a droplet jetting device used to carry out the present invention, and FIG. 2.3 is a manufacturing process diagram showing an embodiment of the present invention. 10... Metal droplet projection device, 11... Nozzle, 12
．． 13... Electrode, 14... Inert gas injection port, 15
...Metal rod sending hole for droplet formation, 16...Metal rod for forming droplet, 17...Model, 18...Metal droplet layer patent Applicant: Mars Manufacturing Co., Ltd. Representative Patent Attorney Yoshi Hiroshi Mura No. 111

Claims (3)

[Claims] (1) After continuously or intermittently projecting droplet-shaped metal onto the surface of the model under an inert gas atmosphere to form a metal droplet adhesion layer on the surface, the metal droplet adhesion layer is A method for manufacturing a mold for a molded article using metal droplets, characterized in that a mold for a molded article made of the metal droplets is obtained by separating the metal droplets from a model. (2) The method for producing a mold for a molded article using metal droplets according to claim 1, wherein argon gas is used as the inert gas and aluminum or aluminum alloy is used as the metal. (3) A method for manufacturing a mold for a molded article using metal droplets according to claim 1, wherein a metal sprayed layer with a thickness of several microns is interposed on the surface of the model.