JPS625299Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Field of Application> The disclosed technology belongs to the field of molding technology that eliminates burrs on the mating surfaces of molds used in injection molding by resin casting.

<Summary of the gist> This invention uses a rigid core material such as A as a back-up reinforcing material for both fixed and movable resin casting type injection molds, and the cavity of the product molding part and its This is an idea for a resin casting type mold structure in which a resin layer is provided on the mating surface of the side extension part and attached to the core material.In particular, the resin layer is made of urethane resin to resist mold clamping pressure. It was made to be plastically deformable, and a urethane resin tank was attached to the core material not only in the cavity but also at least from the side extension to the cavity where the mating surface of the side extension from the cavity and the core material met. This is an idea related to the structure of a resin mold.

<Prior art> As is well known, resin injection molded products are used in an extremely wide range of fields, but the mold used for molding them is generally a fixed mold that clamps a movable mold, material resin is injected, and molded in a cavity. Although the mold is then opened, some molds have been used in which a casting resin layer is added to the core material based on the so-called resin casting method.

As shown in FIG. 1, both the fixed mold 2 and the movable mold 3 of the resin casting mold 1 have a core material 4 as a back-up reinforcing material made of a rigid body such as ZAS or A. 5, an epoxy resin layer 8 is attached to the core material 4 on the cavity 6 and its side extension 7, and when the mold is clamped, the mating surface 10 of the mold mating part 9 of the core material 4 is zero-aligned, and in that case, In order to prevent the side extensions 7 of the resin layer 8 from being cracked due to their material inability to withstand mold clamping pressure, the mating surface 11 of the side extensions 7 of the molded part 5 is
A clearance d of 0.1 to 0.2 mm is formed between the two.

<Problems to be solved by the invention> However, when molding the product 12 into the cavity 6 by injecting resin, there is a drawback that burrs are inevitably formed on the side extensions 7. However, deburring is required in the post-process, which requires a lot of man-hours and has a disadvantage that the product production cycle is poor.
As a result, there were also disadvantages that led to higher costs.

The purpose of this invention was to solve the technical problem of the resin casting type injection molding mold based on the conventional technology mentioned above, and to replace the resin layer with epoxy resin and make it with urethane resin, and to We provide an excellent resin mold structure for the resin product manufacturing industry by ensuring that the parts are zeroed to prevent burrs from occurring, and that the core material is also freely zeroed to support mold clamping pressure and injection pressure. That is.

<Means and actions for solving the problem> In accordance with the above-mentioned purpose, the structure of this invention, which is summarized in the scope of the above-mentioned utility model registration claim, is to solve the above-mentioned problem by clamping the movable mold with respect to the fixed mold. Monkey and
The core material or the urethane resin attached to the core material is zero-aligned and subjected to mold clamping pressure, and in this state, the urethane resin layer of the molded part is elastically compressed and deformed by the mold clamping pressure, and in that state, the resin In this case, the urethane-based resin layer of the cavity is used in such a way that it is not compressively deformed at a molding injection pressure lower than the mold clamping pressure.

<Example> Next, an example of this invention will be described below based on FIGS. 2 and 3. Note that the same parts as in FIG. 1 will be explained using the same reference numerals.

In the embodiment shown in FIG. 2, 1' is a mold for resin injection type injection molding, and both the fixed mold 2' and the movable mold 3' have a core material 4, and are both made of A. The resin layer 8' adhesively attached to the molded part 5' is made of urethane resin, and forms the cavity 6', and is attached to the side extensions 7' of the cavity 6' to form the mating surfaces of the side extensions 7', 7'. 11', 11' are in contact with each other, as shown in the figure, there is a step difference d, for example, 0.1 to 0.2, with respect to the mating surface 10' of the mating portion 9' of the core material 4.
It is formed with a protrusion of mm.

In the above structure, when performing injection molding, when the movable mold 3' is brought close to the fixed mold 2' and the mold is clamped, first, as described above, the side extensions 7', 7 of the resin layers 8', 8' are The parts up to the mating surfaces 11', 11' of the core materials 4, 4 touch zero as shown in FIG.
When the resin layers 8', 8' are pressed tightly against each other to support the mold clamping pressure, the side extensions 7', 7' of the resin layers 8', 8' are elastically compressed through the urethane resin material, and the injection pressure is increased. can be supported.

Therefore, when a predetermined amount of resin is injected, the product 12 is molded in the cavity 6', but in this case, the resin layers 8', 8' of the cavity 6' are almost completely formed by lowering the injection molding pressure lower than the mold clamping pressure. Not deformed.

Therefore, even if the mold is subsequently opened and the product 12 is taken out, no burrs are formed on the product 12, and therefore, post-deburring work is not necessary.

Further, the embodiment shown in FIG. 3 has mating surfaces 11'', 1
0'' was a flat surface in the above embodiment, but is formed as a free curved surface, and therefore, the resin layer 8''
However, not only the cavity 6'' of the molded part 5'', but also the side extending portion 7'' of the above-mentioned embodiment further form the mating portion 9'' of the core material 4,
In this embodiment, side extensions 13, 13 are formed extending up to the side ends of 9''.

Therefore, when the movable mold 3'' is closely clamped to the fixed mold 2'', the mating portions 9'', 9'' of the core material 4 and the side extensions 7'', 7'' of the molded portion 5'', The mating surfaces 11″ and 10″ of the resin layers 13 and 13 are zero-aligned, and further,
The urethane resin material is elastically compressed by the mold clamping pressure and supports the mold clamping pressure.

Of course, in this embodiment as well, the injection pressure is set so that deformation of the cavities 6'', 6'' does not become a problem depending on the injection molding pressure.

Therefore, when the resin is injected and injection molded as in the above embodiment, the product 12 is molded into the cavities 6'', 6'' as designed, and no burrs are formed because the mating surfaces 11'' are tightened.

Therefore, the effect of eliminating the need for deburring the product 12 after opening the mold is exactly the same.

It goes without saying that the embodiments of this invention are not limited to the above-mentioned embodiments, and various other embodiments can be adopted.

<Effects of the invention> As described above, according to this invention, in the resin injection mold structure, the resin layer attached to the molding part is made of a urethane resin layer, so that it basically has a step from the core material. Despite the protruding design, the side extensions of the molded part are not only zero-aligned when the mold is closed, but are also compressed elastically, so that even when subjected to injection pressure, the side extensions remain unchanged. Therefore, there is no burr generation at the mating part on the product, and there is no need for a burr removal process after molding, which shortens the product manufacturing cycle and produces excellent effects that lead to cost reductions.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of a resin casting mold structure based on the prior art, Figs. 2 and 3 are explanatory views of an embodiment of this invention, and Fig. 2 is a schematic cross-sectional view of one embodiment; FIG. 3 is a schematic sectional view of another embodiment. 1', 1''...molding mold, 2', 2''...fixed mold,
3', 3''...Movable type, 4...Core material, 5', 5''...
Molding part, 6', 6"...Cavity, 7', 7"...
Side extension part, 8', 8''...Resin layer, 9', 9''...Matching part.

Claims (1)

[Scope of utility model registration request] In a resin casting type mold structure in which the core of the reinforcing material of the fixed mold and the movable backup of the injection mold is made of a rigid body, and a resin layer is attached to the cavity and side extensions forming the molding part, The resin layer is formed of a urethane resin, and the resin layer is formed continuously from the side extension of the molded part and the inner surface of the end of the core material from at least the side extension to the cavity of the molded part. A resin mold structure characterized by being attached to the core material.