JPH0118332Y2 - - Google Patents

Description

[Detailed description of the invention] (Purpose) The present invention relates to a mold used for molding using liquid rubber for casting. The purpose is to provide formwork that can be easily assembled.

(Prior art) Molten wax is poured into a mold and cooled and solidified to form a wax model used in the lost wax casting method, or a reaction-curing liquid synthetic resin is poured into a mold and cured by reaction. In the so-called casting method, in which synthetic resin molded products are obtained using molded products, a rubber mold is often used that is made by copying a product master using liquid rubber such as silicone rubber or polyurethane rubber. .

To create a rubber mold, first assemble the formwork, place the product master inside the formwork, then inject liquid rubber into the formwork and let it harden, then disassemble the formwork and remove the product master. A method of making a mold has been adopted, and FIGS. 1 and 2 show this method of making a rubber mold as a perspective view and a sectional view.

The conventional formwork used to make this rubber mold is
Frame plates 1, 1' which are simply flat plates as shown in FIG.
are assembled into a rectangular shape by standing upright on the flat plate 2 that will serve as the bottom plate, and the joints between the frame plates and between the frame plate and the flat plate are secured with screws 3.
etc. to be fixedly formed.

Fixing the joints between the frame plates and between the frame plates and the flat plate is as follows:
This is done using screws, adhesives, adhesive tape, etc., but if adhesive is used, it is difficult to remove the adhesive later to disassemble the formwork or reuse the frame board, and it is difficult to use adhesive tape. When used, the fixing force is weak and the assembled formwork often disintegrates due to the gravity of the injected liquid rubber 4.

For this reason, fixation is usually done with screws as shown in Figure 1, but even in this case, the injected liquid rubber may easily leak from the joint, or the size of the formwork required may be insufficient. The disadvantage is that it is necessary to prepare frame plates and flat plates each of a size suitable for each, which is said to be uneconomical.

In other words, liquid rubber for mold-making has a relatively low viscosity of about 1.0 to 1.5 poise and a slow curing time of about 15 to 16 hours due to the need for excellent copyability of Master 6, so it is difficult to bond. It is easy for leakage to occur even from the slightest gap between the parts, and when reusing a frame plate or flat plate to form a formwork of another size, completely seal the already drilled screw holes and insert new screw holes. It becomes necessary to open the room, which is complicated in various ways.

Therefore, if the joints between the frame plates and between the frame plates and the flat plate are fixed by screws, the joints shown in bold lines in Fig. 1 should be fixed with a sealant 5 such as putty as shown in Fig. 2. must be completely sealed.

As mentioned above, the conventionally used formwork requires a surprisingly large number of man-hours to assemble and disassemble, and it is also uneconomical to prepare frame plates and flat plates of various sizes. The inventors arrived at the present invention as a result of intensive studies in order to obtain an economical formwork that is easy to assemble and disassemble, and which can be freely formed into forms of various sizes.

(Structure) That is, in the present invention, ribs are provided on two adjacent sides of a rectangular flat plate, extending over the entire length and protruding in the same direction at right angles to the flat plate surface, and the ribs provided on the two sides intersect with each other at right angles. The edges are tightly fixed to form a frame plate.
The ribs on one side of the frame plate are closely fixed on a flat plate that will serve as the bottom plate and stand upright, and the ribs on one side are placed on the same flat plate as the back side of the ribs on the other side as the bottom plate in the same way as the frame plate. Note that the four frame plates are mutually combined into a tomoe shape to form a rectangular enclosure that stands upright on the flat plate by closely fixing the back side of the flat plate of the other upright frame plate. This is a mold for making a rubber mold for shapes, and more details are as described below based on examples.

FIG. 3 is a perspective view of a frame plate for assembling the formwork of the present invention, which shows two adjacent rectangular flat plates 7.
Ribs 8, 8' projecting in the same direction at right angles over the entire length of the sides are provided, and end portions 9 and 9' of the ribs 8, 8' intersecting at right angles are closely fixed.

A flat plate made of wood, plastic, metal, etc. is used as the frame plate, but when the frame plate is disassembled after molding, it is easy to peel off the lightly bonded rubber and the frame plate is damaged. 1 to 2 mm thick with spring properties to prevent bending or deformation.
steel plates, such as bainitic steel plates or heat-treated SK
Preferably, steel plates are used.

In addition, the ribs that are provided to protrude at right angles on two adjacent sides of the flat plate can be formed by bending the flat plate at right angles, or by fixing an L-shaped angle made of steel with a thickness of 2 to 3 mm as shown in Figure 3. The width of the frame plate must be sufficient to allow the frame plate to stand upright on the flat plate that will serve as the bottom plate, and to be in close contact with the flat plate surface of the flat plate and the adjacent frame plate to prevent leakage of the injected liquid rubber. , usually 50
It is preferable to set it to about mm.

In addition, the adjacent ends of the ribs provided on the frame plate are
They are tightly fixed by gluing, welding, etc., and this is done to prevent the injected liquid rubber from leaking, so there is no gap and it prevents the bottom of the ribs from coming into complete contact with the flat plate. Needless to say, it is necessary to take sufficient care to avoid this.

FIG. 4 is a perspective view of the formwork assembled using the frame plate, and shows a flat steel plate 1 with a thickness of 2 to 3 mm that will serve as the bottom plate.
0, the frame plate 11 is placed upright with one side 12 of the rib in close contact with the flat plate, and fixed with adhesive tape 13. Next, the frame plate 14 is placed upright with one side 15 of the rib in close contact with the flat plate, and the flat plate surface and the above-mentioned It is brought into close contact with the rib 12' on the other side of the frame plate 11 and fixed with a clip 16,
Next, the ribs 15 that are in close contact with the flat plate of the frame plate 14 are fixed with adhesive tape 13.

Using the method described above, four frame plates are placed upright on a flat plate that will serve as the bottom plate, and the ribs and flat plate surfaces are brought into close contact with each other to form a tomoe shape, thereby forming a rectangular enclosure, and each joint is glued. The formwork is assembled by fixing with tape, clips, etc.

(Effects) As is clear from the above explanation of the assembly method, the formwork of the present invention can be assembled using clips, adhesive tape, etc.
It is extremely easy to assemble and disassemble, as the injected liquid rubber will not leak at all even without special sealing at the joints.

Also, since there are no screw holes in the frame plate, it is easy to use it for assembling formwork of various sizes. Therefore, by preparing frame plates of several sizes, it is possible to assemble formwork of various sizes. It is economical to assemble.

Although the formwork of this invention was devised for the creation of rubber molds for casting, it is naturally applicable to the creation of plaster molds, the encapsulation of electronic parts with liquid resins such as epoxy resin, and other liquid substances. It can be effectively used in many fields as a mold for injection.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional formwork, Fig. 2 is a sectional view of the conventional formwork, Fig. 3 is a perspective view of a frame plate for assembling the formwork of the present invention, and Fig. 4 is a perspective view of a frame plate for assembling the formwork of the present invention. FIG. 2 is a perspective view of the formwork of the present invention.

Claims (1)

[Scope of utility model registration request] Ribs are provided on two adjacent sides of a rectangular flat plate extending over the entire length and protruding in the same direction at right angles to the flat plate surface, and the ends of the ribs provided on the two sides, which intersect at right angles to each other, are closely fixed to each other to form a frame. A plate, the ribs on one side of the frame plate are tightly fixed on a flat plate serving as a bottom plate, and the frame plate is made to stand upright.
By closely fixing the back surface of the rib on the other side and the back surface of the flat plate of another frame plate that stands upright with the rib on one side as the bottom surface in the same way as the frame plate, 4.
A formwork for making a rubber mold for casting, characterized in that a rectangular enclosure standing upright on a flat plate is formed by combining two frame plates into a tomoe shape.