JPH0336647B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for injecting a curable resin into a mold using the effects of gravity and centrifugal force under a vacuum condition using the casting machine itself. This invention relates to a casting device that can perform molding in a short time without complication.

[Conventional technology]

When mass-producing industrial products by injection molding with resin, etc., it is necessary to prepare actual samples, decide on the product design, evaluate the external appearance, and conduct physical property tests as a preliminary step. At this time, preparing expensive molds by machining each time a prototype is required.
This led to a rise in development costs, and there were also problems in that it required a great deal of labor and time to create more than a few physical samples by manually bonding materials such as ABS resin and polypropylene resin together.

Therefore, in recent years, a vacuum casting method has been adopted which allows a large number of prototypes to be obtained at low cost in a short period of time. This vacuum casting method is a method of mixing resin and injecting the resin into a mold in a vacuumed work chamber.In particular, the injection of resin into the mold is performed by the gravitational action of the injected resin under a vacuum. This utilizes the press-fitting effect created by the atmospheric pressure in the work chamber after the resin is injected. In this way, by utilizing the gravitational action of the resin under vacuum conditions, the mold is not affected by air or other gases flowing out from inside the mold, and the resin can be fully filled into the mold without bubbles or cavities. It had the advantage of being able to obtain molded products of good quality.

[Problem to be solved by the invention]

On the other hand, with the diversification of required molded products,
Resins are also required to have high mechanical strength and physical properties.However, resins with high mechanical strength and physical properties have a high viscosity, so the effect of gravity on the resin under vacuum conditions and after resin injection has increased. In the conventional vacuum casting method, which is performed by press-fitting by increasing the atmospheric pressure in the working chamber, it has become difficult to fill the mold thoroughly with resin.
Further, even with ordinary resin, it is difficult to completely fill the thin portion of the mold with resin using the conventional vacuum casting method.

For this reason, methods have been devised such as using a gear pump to forcibly feed the resin into the mold and filling the mold by increasing the pressure in the working chamber after resin injection. The latter method requires a pressure device to bring the working chamber from a vacuum state to a high pressure state all at once, making the casting machine itself complicated and expensive. The problem was that it was said to lead to

The present invention has been made in view of the above problems, and uses the gravity and centrifugal force of resin under vacuum conditions to cast a material with high viscosity or to cast into a thin part of a mold. The purpose of the present invention is to provide a casting device that can perform molding reliably and in a short time without complicating the molding machine itself.

[Means for solving problems]

In order to achieve the above object, the casting device of the present invention has the following features:
a defoaming chamber for defoaming the curable material contained in the pot; a working chamber connected to a vacuum pump; a support ring for holding the pot containing the curable material in the working chamber; A rotary table provided below the pot in a room, a mold attached to the rotary table so that the cavity portion is located on the outer circumference side from the center of rotation, and a drive motor for rotating the rotary table at a predetermined speed. It has a configuration that includes.

[Effect]

In the casting device of the present invention, a pot containing a curable material that has been defoamed in a degassing chamber is attached to a support ring provided in a work chamber, and after the mold is attached to a rotary table, the work chamber is brought into a vacuum state. Then, a curable material is injected into the mold from a pot,
Also, at the same time or in conjunction with this injection, a rotary table is rotated to generate centrifugal force, and the curable material is filled into the cavity in the mold by gravity and centrifugal force under a vacuum condition. Therefore, casting can be performed in a short time without complicating the casting machine itself.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

The drawings show an embodiment of the device; FIG. 1 is a partially cut-away front longitudinal sectional view, FIG. 2 is a side sectional view,
FIG. 3 is a partially cutaway enlarged view of the rotating device, FIG. 4 is a schematic diagram of the entire device, and FIGS. 5 A to F are views showing how it is attached to various types of rotating tables.

First, the apparatus of this embodiment will be explained. In the drawing, reference numeral 1 denotes a working chamber, and a first pot 2 and a second pot 5 are arranged above the interior thereof. The first pot 2 is held via a support ring 4 at the inner end of an operating rod 3 which is slidably and rotatably provided through a side wall of the working chamber 1. The second pot 5 also has a support ring attached to the inner end of an operating rod 6 that is slidably and rotatably provided through the side wall of the work chamber 1 so as to be located slightly below the first pot 2. 7
is held through. The first and second pots 2 and 5 are attached to the respective support rings 4 and 7 and are detachable, and the defoamed material is transferred to the pots 2 and 5 in the defoaming chamber 17 shown in FIG.
It is designed so that it can be installed separately. Generally, the first pot 2 contains a curing agent, and the second pot 5 contains a liquid resin. 8 is
The stirring member is fixed to the inner end of an operating rod 9 which penetrates the upper wall of the working chamber 1 and is vertically movable and rotatable, so that the second pot 5 can be stirred.

Reference numeral 10 denotes a rotary table, which is located below the second pot 5 in the working chamber 1 and is arranged horizontally. This rotary table 10 can be rotated at a predetermined rotational speed by a drive motor 11. The drive motor 11 can also be arranged outside the work chamber 1 instead of inside it. Further, a presser member 16 for attaching the mold 12 is provided on the upper surface of the rotary table 10, so that the mold 12 can be attached and removed.

The mold 12 is made of silicone rubber, for example, and includes a cavity part 13 and a gate part 14, and a resin reservoir part 15 connected to the gate part 14 is provided in the upper part of the mold 12. This mold 12 is placed on the rotary table 1.
0, the gate part 14 should be positioned near the center of rotation, and the cavity part 13 should be mounted on the outer periphery side of the center of rotation, so that when the rotary table 10 rotates, the centrifugal force causes resin to flow inside the cavity part 13. Make sure that it flows easily. Furthermore, the shape of the mold 12 is symmetrical or nearly symmetrical with respect to the center of rotation in order to maintain balance during rotation.

The shape of the mold 12 can be, for example, a rectangle, a square, a three-star shape, a pentagonal shape, a hexagonal shape, or a circular shape as shown in FIGS. 5A to 5F.

A vacuum pump 18 is installed in the work chamber 1 and the degassing chamber 17.
There are provided a pipe 19 that connects to the air and a leak pipe 21 that communicates with the atmosphere. And these piping 1
Opening/closing valves 20, 22 are attached to the opening/closing valves 9, 21, respectively, and by opening and closing these opening/closing valves 20, 22, the working chamber 1 and the degassing chamber 17 are switched between a vacuum state and an atmospheric pressure state. In addition, 23 is
It is an operating device that controls the rotation, stop, and rotational speed of the drive motor 11 of the rotary table 10 and the on-off valve 20.
Issues various operation signals such as opening/closing commands of 22.

Next, the operation of the casting device having the above configuration will be explained.

A mold 12 is attached to a rotary table 10.

In the defoaming chamber 17, the support ring 4 of the operating rod 3 and the supporting ring of the operating rod 6 are placed so that the defoamed curing agent and liquid resin are located in the working chamber 1 together with the first pot and the second pot. Attach each to 7.

In this way, before attaching the first pot and the second pot to the support ring in the work chamber 1, the material contained in the pots is degassed in the degassing chamber in advance, thereby degassing the material inside the work chamber. There is no need to carry out any process, and casting can be carried out immediately in the work room. Therefore, casting can be carried out in a short time.

The inside of the work chamber 1 is in a vacuum state, and the operating rod 3 is operated to pour the curing agent from the first pot 2 to the second pot 5 (at this time, the stirring member 8 is moved to a position where it does not interfere with the first pot 2). (let it rise).

Under a vacuum condition, the stirring member 8 is lowered by operating the operating rod 9, inserted into the second pot 5, and rotated to mix the liquid resin and the curing agent to form a curable resin.

Operate the operating rod 6 to pour the mixed resin from the second pot 5 into the reservoir 15 (at this time,
The stirring member 8 is raised again to a position where it does not interfere with the first pot 2).

In this way, since a pot is used as a means of pouring the material into the mold, the casting machine itself is not complicated compared to using a material supply pipe, etc., and it is easy to replace the pot. , it is also possible to easily change to other materials.

Simultaneously with, before, or immediately after pouring the resin into the reservoir 15, the rotary table 10 is rotated by the drive motor 11 at a predetermined rotational speed depending on the curing speed or viscosity of the resin. As a result, since gravity and centrifugal force act on the resin under a vacuum condition, the resin flows into the cavity part 13 through the gate part 14 due to the action of both forces, and is completely filled. In addition,
At this time, it is also possible to close the on-off valve 20 and open the on-off valve 22 to bring the inside of the work chamber 1 to atmospheric pressure immediately after pouring the resin, and further apply pressure equal to the atmospheric pressure.

The rotary table 10 is rotated for a predetermined period of time, and then the mold 12 is removed from the rotary table 10 and necessary processing is performed.

The apparatus of the present invention can also be used to mold cast products from materials such as rubber, ceramics, or wax.

〔Effect of the invention〕

As described above, the casting device of the present invention is designed to defoam the material housed in the pot in the defoaming chamber in advance, so there is no need to defoam the material in the work chamber, and the casting process can be completed in a short time. can be done.

Furthermore, since the casting apparatus of the present invention employs a pot as a means for pouring the material into the mold, the casting machine itself does not become complicated compared to the case where a material supply pipe or the like is used. By replacing the pot,
Materials can also be easily changed.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention.
The figure is a partially cutaway front vertical sectional view, Figure 2 is a side sectional view, Figure 3 is a partially cutaway enlarged view of the rotating device, Figure 4 is a schematic diagram of the entire device, and Figures 5A to F. FIG. 3 is a diagram showing how it is attached to various types of rotary tables. 1: Working room, 2: First pot, 3: Operation lever,
4: Support ring, 5: Second pot, 6: Operation rod,
7: Support ring, 10: Rotary table, 11: Drive motor, 12: Mold, 15: Reservoir.

Claims (1)

[Claims] 1. A defoaming chamber for defoaming the curable material contained in the pot, and a working chamber connected to a vacuum pump;
a support ring for holding a pot containing a curable material in the working chamber; a rotary table provided below the pot in the working chamber;
A casting device comprising: a mold attached to the rotary table so that the cavity portion is located on the outer peripheral side from the center of rotation; and a drive motor that rotates the rotary table at a predetermined speed.