JPH0586326B2 - - Google Patents

Description

Detailed Description of the Invention "Industrial Application Field" The present invention involves molding a high-precision silicone rubber mold from a master mold, and molding a two-component urethane resin,
The present invention relates to a vacuum casting apparatus for injecting epoxy resin in a vacuum and then releasing the vacuum to feed the resin into the details of the silicone rubber mold, thereby molding a three-dimensional replica.

"Conventional Technology" In recent years, the need for industrial model resins has been increasing year by year as an essential material for the development of industrial products. Generally, when mass-producing industrial resin products by injection molding of typical commercially available thermoplastic resins, the preliminary step is to create actual samples, decide on the product design, evaluate external appearance, and conduct physical property tests on packaging. There is a need. At this time, each time we made a prototype, we
Preparing expensive molds using machine tools increases development costs and is a heavy burden. Furthermore, it takes a great deal of effort and time to manually attach ABS resin, polypropylene resin, etc. and create several physical samples. As a means to solve this problem, in the prototyping industry, a high-precision rubber mold is molded from a master mold using silicone rubber, and a two-component thermosetting resin such as urethane or epoxy resin is vacuum poured into the rubber mold. Type devices are becoming popular.

``Problems to be solved by the invention'' In the conventional vacuum casting equipment as described above, automation of vacuum work in all processes has not been established, so air bubbles may be mixed in during the process, resulting in high There was a problem in that it was difficult to easily mold accurate three-dimensional replicas. In addition, in order to prevent this, defoaming operations must be repeated, which is time consuming, and the three-dimensional reproduction product itself has to be expensive. The present invention solves the above problems, and
The purpose of the present invention is to provide a vacuum casting device that can automate the entire vacuum casting process and easily form highly accurate three-dimensional replicas.

"Means for Solving the Problems" The structure of the vacuum casting apparatus according to the present invention to achieve the above-mentioned object of the present invention is that air present in a liquid such as two-component liquid urethane resin or epoxy resin is A vacuum stock solution tank from which liquid urethane resin, epoxy resin, etc. are extracted, a liquid delivery pump that discharges a predetermined amount of liquid urethane resin, epoxy resin, etc. from this vacuum stock solution tank, and a liquid urethane resin, epoxy resin, etc. delivered by this liquid delivery pump. It comprises a receiving part for receiving the liquid, a stirring means for stirring the liquid, and a vacuum working chamber provided with a release means for releasing the vacuum after injecting into a silicone rubber mold provided in advance. Furthermore, as a preferred embodiment of the present invention, a turntable on which a large number of silicone rubber molds are placed is provided at the bottom of the vacuum work chamber, so that urethane resin, epoxy resin, etc. can be injected into a large number of silicone rubber molds at once. Multiple production in one process is possible. Furthermore, by providing lighting means in the vacuum work chamber, it is possible to work in a bright and comfortable manner.

"Function" The present invention is a two-component liquid urethane resin, epoxy resin, etc., in which predetermined amounts of the main resin and curing agent are measured, and which are vacuum degassed in a vacuum stock solution tank. liquid urethane resin,
A predetermined amount of epoxy resin, etc. is discharged into the receiving part of the vacuum work chamber using a liquid feed pump, and this is stirred by a stirring means in the vacuum work chamber or a part connected thereto, and then the resin is poured into a silicone rubber mold prepared in advance. injected in a vacuum work chamber. Thereafter, the vacuum in the vacuum working chamber is released by a release means, and the resin is pushed into the silicone rubber mold to the smallest detail. Also, the portion connected to the vacuum working chamber can be placed under vacuum if necessary.

"Embodiments" Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the component parts described in this example are as follows, unless otherwise specified.
This is not intended to limit the scope of the invention, but is merely an illustrative example.

FIG. 1 is a front view showing an embodiment of a vacuum casting apparatus according to the present invention.

FIG. 2 is a front view showing a working chamber as a vacuum working chamber in the same embodiment.

FIG. 3 is a front view of a fluorescent lamp as illumination means for the vacuum work chamber in the same embodiment.

Figures 4 and 5 show the casting procedure of the vacuum casting apparatus according to the present invention, Figure 4 is a process diagram for molding a silicone rubber mold from a master mold, and Figure 5 is a three-dimensional reproduction from a silicone rubber mold. It is a process diagram of molding a product.

In Fig. 1, reference numerals 1 and 1 are stirring handles, which are sealed with O-rings, Teflon materials, etc., in order to maintain airtightness within the working chamber 20, which will be described later as a vacuum working chamber. Vibration of the stirring handles 1, 1 can also be prevented by this. Further, reference numerals 2 and 2 denote a casting handle, and 3 a casting outlet, through which liquid urethane resin and epoxy resin are injected into a silicone rubber mold 21 provided in advance in the working chamber 20. 4 is
It is an operation control panel for performing various tasks.
0 is a pipe for delivering from 4 to the casting outlet 3. 5 and 5' are stirring handles for manually stirring the resin stock solution, but 5' is not shown because it is located directly behind 5. 6 is work room 2
This is a vacuum gauge that displays the degree of vacuum, such as within 0. 7 is
It is a swivel handle. Reference numerals 8 and 10 are discharge rate adjustment switches for adjusting the discharge rate of different stock solutions, and accordingly discharge rate adjustment handles 9 and 11 are provided.
In addition, valves 12, 12 are provided for draining the remaining liquid in the vacuum stock solution tank when replacing the stock solution. Reference numerals 13 and 13 are grounding adjustment bolts that ground the device.

In the working chamber 20 as the vacuum working chamber,
A circular turntable 23 is attached to a shaft 24, and the turntable 23 is manually raised and lowered and rotated from the outside via a transmission means such as a chain and an adjustment means such as a speed reducer. Thereby, a large number of silicone rubber molds 21 placed on the turntable 23 can be injected in one step.

Furthermore, a fluorescent lamp 25 as illumination means is attached to the upper part of the work chamber 20, and this fluorescent lamp 25 is enclosed in a glass tube 27 via a fluorescent lamp holder 26. A cover 3 is attached to the glass tube 27 via a glass tube holder 28 and a bush 29.
0 is attached. An O-ring 31 is fitted between the fluorescent lamp 25 and the fluorescent lamp holder 26, and similarly between the fluorescent lamp holder 26 and the glass tube 27, between the glass tube holder 28, and the glass tube holder. O between 28 and bush 29 respectively
Rings 32, 33, and 34 are fitted. As a result, the glass tube 27 is completely sealed, and the working chamber 2
It is possible to brighten the area within 0.

Furthermore, the cup receiver provided in the work chamber 20 as a receiving part has a metal ring coated with silicone rubber to prevent slipping in order to invert the cup.

On the other hand, although not shown in FIGS. 1 and 2, the vacuum casting apparatus according to the present invention is used as a vacuum stock solution tank for removing air, etc. present in the liquid of two-component liquid urethane resin or epoxy resin. The degassing chamber is 5,5'
A liquid feed pump is provided within the working chamber 20 to deliver a predetermined amount of the resin from the defoaming chamber into the working chamber 20. Further, in or near the work chamber 20, there is a stirring means for stirring the cup-receiving resin that receives the resin from the liquid feeding pump in the vacuum work chamber or a part connected thereto, and the leak valve is opened. A release means for releasing the vacuum in the working chamber 20 is also provided. Next, the process of molding a silicone rubber mold from a master mold will be explained based on FIG. First, a master model is obtained through the master manufacturing process 40 in the figure. The material of this model is not limited to metal, plastic, wood, etc. Next, reference numeral 41 serves as an injection port for injecting resin into the mold in the process of bonding the gate and setting the master. 42 is a formwork set, and a plate-shaped formwork is assembled to surround the master from all sides. On the other hand, 43
After passing through the resin measuring step 44, the vacuum-defoamed resin is mixed with a silicone rubber main ingredient and a curing agent in a two-liquid mixing step 45. Next, these are injected into a mold 46, and in a vacuum defoaming step 47, the air trapped during rubber injection is defoamed under reduced pressure vacuum. After that, in the curing process of 48, at room temperature, about 25 degrees Celsius.
It will harden in 6 to 8 hours if left for 20 to 24 hours or in an atmosphere of about 60 degrees Celsius. Then, in the mold opening step 49, the mold is removed, the rubber mold is incised with a surgical scalpel, and the master model is taken out to complete the rubber mold. Further, based on FIG. 5, the process of molding a three-dimensional replica from a silicone rubber mold will be explained. First, a predetermined amount of the main resin and curing agent is measured using a resin metering unit 50. Next, by vacuum degassing 51,
Vacuum defoaming is performed in a vacuum stock solution tank. The resin, base resin, and curing agent that have been degassed are mixed in vacuum 52.
Mix and stir. On the other hand, by cleaning the rubber mold in Step 53, dirt on the parting surface is wiped off, and if it is difficult to release from the mold, a mold release agent is applied. Then, the molds are matched using a set of 54 rubber molds, the frame plates are applied from both sides, the molds are clamped with rubber rings, etc., and the resin pool is attached to the gate part. Therefore, the resin obtained by vacuum mixing 52 is injected into a rubber mold and vacuum casting 55 is performed. When this is completed, the vacuum pump is stopped, the inside of the working chamber 20 is returned to atmospheric pressure, and the resin is pushed into the details. Thereafter, a curing step at 56 leaves the entire mold under the curing time conditions of the resin. As a typical condition, it can be cured by leaving it in a constant temperature bath at 60 degrees Celsius for 30 minutes. Then, in the mold release step 57, the frame plate holding the rubber mold is removed, the mold is released, and the relay product is taken out. Next, in the finishing step 58, the gate is cut, and the gate marks, burrs, etc. of the parting are polished with a file, etc., and the product is completed 59. In this way, the three-dimensional replicas molded can be molded into hard, soft, elastic, or transparent materials depending on the selection of resin, and can be used for product development and product samples of automobile parts, equipment parts, home appliance parts, etc. , used for toys, buttons, ornaments, accessories, etc. whose designs often change.

"Effects of the Invention" As described above, according to the present invention, there is provided a vacuum stock solution tank that removes air, etc. present in a two-component liquid urethane resin, epoxy resin, etc., and a vacuum stock solution tank that removes the liquid urethane resin from the vacuum stock solution tank. , a liquid feeding pump for discharging a predetermined amount of epoxy resin, etc., a receiving part for receiving liquid urethane resin, epoxy resin, etc. sent out by this liquid feeding pump, stirring means for stirring this, and silicone rubber provided in advance. Since it has a vacuum work chamber equipped with a release means for releasing the vacuum after pouring into the mold, it is possible to automate the vacuum casting work in the entire process and easily create highly accurate three-dimensional replicas. This has the effect of making it possible to

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of a vacuum casting apparatus according to the present invention. FIG. 2 is a front view showing a working chamber as a vacuum working chamber in the same embodiment. FIG. 3 is a front view of a fluorescent lamp as illumination means for the vacuum work chamber in the same embodiment. Figures 4 and 5 show the casting procedure of the vacuum casting apparatus according to the present invention, Figure 4 is a process diagram for creating a silicone rubber mold from a master mold, and Figure 5 is a three-dimensional reproduction from a silicone rubber mold. It is a process diagram for creating a product. 1...Stirring handle, 2...Pouring handle, 3
...Casting outlet, 4...Operation control panel, 5...Stirring handle, 20...Working chamber, 21...Silicone rubber mold, 23...Turntable, 24...Shaft,
25...Fluorescent light.

Claims (1)

[Scope of Claims] 1. A vacuum stock solution tank for removing air present in a two-component liquid urethane resin, epoxy resin, etc., and a predetermined amount of the liquid urethane resin, epoxy resin, etc. from this vacuum stock solution tank. The liquid urethane resin, epoxy resin, etc. sent out from the liquid feed pump are stirred by a stirring means in a vacuum working chamber or a part connected to the vacuum working chamber to form a pre-prepared silicone rubber. A vacuum casting device comprising a vacuum work chamber provided with a release means for releasing the vacuum after pouring into the mold. 2. The vacuum casting apparatus according to claim 1, wherein the vacuum working chamber has a turntable on which a large number of silicone rubber molds are placed at the bottom thereof. 3. The vacuum casting apparatus according to claim 1 or 2, wherein the vacuum working chamber has lighting means.