JPH0217852Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention involves mixing and stirring a liquid synthetic resin and a hardening agent, injecting the mixture into a cavity such as a rubber mold, and then reacting and hardening the mixture in the mold. This invention relates to a mixing/stirring device in the law.

(Prior art) The synthetic resin casting method does not require a strong mold unlike injection molding, as the synthetic resin and curing agent, which are liquid at room temperature, are mixed, stirred, and injected into the mold. Since liquid synthetic resin can be supplied to the details inside the cavity with no pressure or only a slight pressure, the mold cost is low, and the ratio of equipment costs and energy costs is also lower than that of conventional injection molding methods, resulting in improved product quality. Because it takes only a short time to obtain, it is widely used for decorative items and prototypes for high-mix, low-volume production. The conventional technique of the above casting method will be explained with reference to FIG. 1. A mold 2 is set in a vacuum chamber 1, and a base material and a hardening agent are mixed in an injection receiver 3 attached to the mold 2. After pouring the liquid synthetic resin 4, the chamber lid 5 is closed, the vacuum valve 6 is opened, and the vacuum pump P is used to suction and exhaust. As the pressure in the vacuum chamber 1 is reduced, the air in the mold cavity 2a and the air drawn in during mixing and stirring of the base resin and curing agent pass through the injected resin to the outside of the mold, and then through the vacuum pump P to the vacuum chamber 1. Expelled outside. After completing the exhaust inside the mold, close the vacuum valve 6, open the leak valve 7, and open the vacuum chamber 1.
Guide the atmosphere inside. Synthetic resin injected with atmospheric pressure 4
is pressurized, the resin flows around to every corner of the vacuum mold cavity 2a, hardens within the mold, and is cast.

According to the conventional method, the curing time after mixing the main resin and curing agent is relatively long, for example, 5 to 6
Good molded products can be obtained without any problems by casting for materials that take more than a minute or so, but some resins that harden within a short time after mixing, such as urethane resins that harden within about 30 seconds after mixing, may also be used. This type of resin is commercially available, and with this type of resin, it takes more time than the curing time mentioned above to close the lid 5 of the vacuum chamber 1, suck and exhaust the air, and reduce the pressure to a degree of pressure reduction suitable for casting, for example, about 5 mmHg. In this case, the casting resin progresses in hardening during depressurization and loses fluidity, resulting in the inconvenience that a good cast product cannot be obtained.
Since the decompression speed is determined by the volume of the space inside the vacuum chamber 1 and the displacement per hour of the vacuum pump P, in order to solve the above-mentioned problems, it is necessary to reduce the chamber capacity and use a vacuum pump with a large displacement. This can be solved by using a decompression tank with a large capacity, or by pre-depressurizing the tank and then operating a valve to rapidly suck out the air in the chamber, but this is not a cost-effective equipment. becomes. Therefore, it is extremely difficult to apply the conventional apparatus as described above to resins that require a short curing time.

(Purpose) The purpose of the present invention is to vacuum degas the two liquids, the base agent and the curing agent, set in a vacuum chamber in an unmixed state, and to remove the two liquids by operating from outside the vacuum chamber. By providing a mixing and stirring device that enables mixing and stirring and injection into molds, it is possible to obtain good cast products even for resins that have a high curing speed, without being affected by the depressurization speed of the vacuum chamber. The aim is to make sure that

(Example) The present invention will be explained below with reference to an example. In FIGS. 2 to 4, 10 is a first storage tank having an opening 10a at the lower end, and a second storage tank 11 has a plurality of connecting pieces 1.
The inner and outer peripheral surfaces of the first storage tank 10 and the second storage tank 11 are coated with silicone rubber, etc., and are supported concentrically with the second storage tank 10 through 2, and are each made of a metal material as a core material. The molding resin is coated to make it easy to peel off the casting resin that adheres and solidifies during the casting process. Reference numeral 13 denotes an agitating body, which includes a core material 14 made of a metal material, and a shaft portion 13a and blade portions made of polyacetal resin or the like so that resin for casting adheres to the core material and is easily peeled off after solidification. 13b. The stirring body is provided concentrically with the first storage tank 10 described above, and is configured to be able to slide in the axial direction and be positioned at a plurality of positions, and to be rotatable about the shaft portion 13a. That is, the stirring body 13 can first be positioned at the first position as shown in FIG.
The first storage tank 10 and the second storage tank 11 can store different liquids, one for the hardening agent and the other for the main agent.
Regarding the storage tank 10, the outer peripheral surface 13 of the blade portion 13b
c is brought into close contact with its inner peripheral surface 10b, and the upper surface 13d of the blade portion becomes the bottom of the first storage tank, and as for the second storage tank 11, the lower end of the shaft portion 13a is brought into close contact with the inner surface of the outlet 11a of the second storage tank. Each of these storage tanks becomes a closed stopper and has a bottom. Further, the stirring body 13 can be positioned at the second position shown in FIG.
is not in contact with the inner circumferential surface 10b of the first storage tank 10, so the liquid in the first storage tank 10 is poured into the second storage tank 11 through the opening 10a, and the stirring body 13 is rotated by an external operation to be described later. For example, the two liquids in the first storage tank 10 and the second storage tank 11 can be mixed and stirred within the second storage tank. The stirring body 13 can also be positioned in a third position as shown in FIG.
In this state, the outlet 11a is opened and the mixed resin 15 is poured downward. The first storage tank 10, the second storage tank 11, and the stirring body 13 described above constitute a mixing and stirring device 16.

(Operation) Next, the operation of the present invention configured as described above will be explained. To perform casting, first, as shown in FIG. 5, the mixing and stirring device 16 is set on the pedestal 20 in the vacuum chamber 19 in which the mold 18 to which the injection receiver 17 is attached is set. The body 13 is positioned at the first position as shown in FIG. 13 shaft portion 13a with the lid 2
The vacuum seal bearing 22 fixed to the vacuum seal bearing 1 is inserted and pulled out of the vacuum chamber 19, and the vacuum chamber 19 and the lid 21 are brought into close contact with each other, and the shaft portion 13a is connected to the handle 24 by the connecting pin 23. Next, the vacuum valve 25 was opened and the vacuum pump P was used to suction and exhaust air to exhaust the entire interior of the vacuum chamber 19 and the cavity 18a of the mold 18, and the curing agent 25a and the base agent 15b were sufficiently degassed under reduced pressure. Thereafter, by operating the handle 24, the stirring body 13 is pushed down to the second position and then rotated as shown in FIG. Through this operation, the curing agent 15a is poured from the first storage tank 10 onto the base agent 15b in the second storage tank 11, and when the stirring body 13 is rotated by operating the handle, these are uniformly mixed by the blade portion 13b. .
After sufficient mixing, the stirring body 13 is pulled up to its third position as shown in FIG. 7 by operating the handle 24, the outlet 11a is opened, and the mixed resin 15 in the second storage tank 11 is It is injected into the cavity 18a of the mold 18 through the outlet and the injection receiver 17. Next, the operation of the vacuum pump P is stopped, the vacuum valve 25 is closed, and the leak valve 26 is opened to introduce the atmosphere into the vacuum chamber 19. Atmospheric pressure pressurizes the injected resin, causing the resin to reach every corner of the vacuum mold cavity and harden inside the mold, resulting in casting.

(Effects) As described above, according to the present invention, the two liquids, the base agent and the curing agent, set in the vacuum chamber can be vacuum degassed in an unmixed state, and the two liquids can be degassed by an operation from outside the vacuum chamber. By providing a mixing/stirring device that enables mixing and stirring and injecting into a mold, it is possible to produce good cast products even for resins with a high curing speed without being affected by the depressurization speed of the vacuum chamber. can get.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a conventional technique in the casting method, and FIGS. 2 to 7 relate to embodiments of the present invention.
FIG. 2, FIG. 6, and FIG. 7 are longitudinal cross-sectional views of the mixing and stirring device, showing the first, second, and third positions of the stirring body, respectively, in this order. Figure 3 is a perspective view of the stirring body, Figure 4 is a perspective view of the mixing and stirring device with the stirring body removed, and Figure 5 shows the mixing and stirring device set in the vacuum chamber of the casting device. It is a longitudinal cross-sectional view showing a state of use. 10 is a first storage tank, 10a is an opening, 11 is a second storage tank, 11a is an outlet, 13 is a stirring body, 13a is a shaft portion, 13b is a blade portion, 15a is a hardening agent, 15b
16 is a mixing and stirring device, and 19 is a vacuum chamber.

Claims (1)

[Scope of utility model registration request] In the casting method, in which a liquid synthetic resin made by mixing a base resin and a hardening agent is injected into a mold and hardened, molding is performed using vacuum defoaming of the base resin and hardening agent and the pressure difference between vacuum and atmospheric pressure. A mixing/stirring device that is set in a vacuum chamber that is depressurized and then opened to atmospheric pressure to pressurize the liquid synthetic resin injected into the chamber, and that is operated from the outside of the vacuum chamber, with an opening at the bottom end. a second storage tank provided concentrically with the first storage tank and having an outlet at the lower end; and a second storage tank provided concentrically with these and capable of sliding positioning in the axial direction and rotating around the shaft portion. At the first position, the first storage tank and the second storage tank are each placed in a bottomed state so that they can store different liquids, and at the second position, the liquid in the first storage tank is poured into the second storage tank. The bottomed state of the first storage tank is opened so that it can mix with the liquid in the second storage tank, and mixing and agitation can be performed using a blade, and the outflow port of the second storage tank is opened at the third position. A mixing and stirring device for the casting method, which comprises a body and a body.