JPH0471695B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a molding method in injection molding, etc., and more specifically, a resin molding method for obtaining a resin molded product to which metal parts are fixed. Regarding.

(Prior art) Conventionally, in molding processes such as injection molding, when obtaining a molded product in which a metal part and a resin part are fixed,
The above-mentioned molded product is obtained by placing the metal part in advance at a predetermined position in the mold, and after the mold is clamped, molten resin is filled under pressure into the cavity.

(Problem to be solved by the invention) However, if the molding process is performed with the metal parts simply placed on the mold, the position of the metal parts may shift when the molten resin is pressurized and filled into the cavity. There is a problem in that it is easy for defective products to occur.

The present invention has been made to solve the above-mentioned problems, and aims to provide a resin molding method that improves the quality of molded products.

(Means for Solving the Problems) The technical means of the method of the present invention to achieve this object is that in a molding method that obtains a resin molded product to which metal parts are fixed, magnetic materials such as iron or the like are placed in the mold. A metal part made of a material is held and fixed by a magnet whose magnetized surface faces the cavity side and which is provided so that one of the pair of magnets can be elastically biased toward the other magnet by a spring and slid to the other side, After mold clamping, molten resin is pressurized and filled into the cavity of the mold,
The method is characterized in that the molten resin is cooled and solidified in a mold, and then the mold is opened to obtain a resin molded article to which the metal parts are fixed.

(Function) With the above configuration, the present invention can prevent the metal parts from shifting due to the filling pressure of the molten resin by molding the metal parts while securely fixing them with a magnet. A molded product of good quality can be obtained.

In the present invention, the material of the metal parts is a magnetic material, generally iron. The magnet is arranged in the mold so that the magnetized surface faces the cavity side, and it is preferable to use a permanent magnet rather than an electromagnet. In insert molding in which a metal part is fixed inside a resin part, the resin part undergoes molding shrinkage, so there is no risk of the metal part coming off from the resin part. In this insert molding, the functional part of the metal part is molded so as to be exposed outside of the resin part. The resin molding process of the present invention can also be applied to outsert molding in which a metal part is fixed to the outside of a resin part, and can be performed by molding methods such as injection molding, compression molding, blow molding, and transfer molding.

(Example) Specific examples of the method of the present invention will be described below. In this embodiment, as shown in FIG. 2, a glass breaking jig 6 is injection-molded to a resin part 3 consisting of a head 1 and a handle 2, and to which a steel breaking element 5 having a pointed end 4 is fixed. This is applied to processing methods that involve Reference numeral 5a in FIG. 2 is a notch groove formed in the destroyer 5 to prevent detachment.

As shown in FIG. 1, a pair of magnets 7 are attached to a predetermined position of the fixed mold 8 so that the magnetized surfaces of different polarities face each other. In this case, one of the pair of magnets 7 is provided so as to be slidable toward the other side,
This is elastically biased toward the other magnet 7 by a spring (numeral 9 in FIG. 1). In this configuration, the stepped portion indicated by the reference numeral 10 in FIG. 1 serves as a positioning stopper surface for one of the magnets 7. Next, when the rod-shaped destroyer 5 is attached between the pair of magnets 7, the destroyer 5
is strongly fixed in a state where both its pointed ends are magnetically attracted and held by a pair of magnets 7.

After this, the movable mold (not shown) is activated to clamp the mold.
The cavity is filled with molten thermoplastic resin under pressure. At this time, the filling pressure depends on the molding conditions.
600 to 2,000 Kgf/cm ² , but since the destroyer 5 is firmly attracted and fixed by the pair of magnets 7, it will not be displaced by the filling pressure of the molten resin. Next, the molten resin is cooled and solidified in the mold, and then the mold is opened to obtain a window glass breaking jig 6 in which the destroyer 5 is integrally fixed to the head 1 of the resin component 3. Obtained window glass breaking jig 6
As described above, since there is no displacement of the destroyer 5 and the resin part 3 shrinks slightly after molding, the adhesion strength of the destroyer 5 to the resin part 3 increases accordingly. Therefore, even if only one detachment prevention notch 5a is formed in the destroyer 5 as shown in FIG. 3, the destroyer 5 will not come off from the resin component 3 during use.

In the above embodiment, the handle part 2 of the resin part 3 is separately injection molded, the destroyer 5 is magnetically fixed in the mold, and the handle part 2 of the resin part 3 is
is fitted into a mold and fixed in advance, and then molten resin is injected only into the portion corresponding to the head 1 of the resin part 3 to form the window glass breaking jig 6.
You may also obtain

In the resin molding method of the present invention, a plurality of metal parts may be fixed by the magnet. Additionally, metal parts may be fixed within the movable mold if necessary.

(Effects of the Invention) As described above, according to the resin molding processing method of the present invention, the molten resin is injected while the metal parts in the mold are securely fixed by the magnet. The filling pressure does not cause displacement of the metal parts, thereby preventing the occurrence of defective products and increasing the adhesion strength between the resin parts and the metal parts. One of the pair of magnets is elastically biased toward the other magnet by a spring, and the metal part is held and fixed by the magnet provided so that it can slide toward the other side, so the dimensions and shape of the metal part are not particularly limited. Moreover, it has the effect of being able to securely fix even complex-shaped objects, and being applicable to both horizontal and vertical molds.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a mold according to the method of the present invention;
2 and 3 are partially cutaway front views showing a window glass breaking jig obtained using the mold shown in FIG. 1. FIG. 3...Resin parts, 5...Destroyer (metal parts),
6... Window glass breaking jig (resin molded product), 7...
Magnet, 8...Fixed type.

Claims (1)

[Claims] 1 A metal part made of a magnetic material such as iron is placed in a mold with the magnetized surface facing the cavity side, and one of the pair of magnets is elastically biased toward the other magnet by a spring, and the other side is moved. The mold is held and fixed by a slidably provided magnet, and after the mold is clamped, a molten resin is pressurized and filled into the cavity of the mold, and after the molten resin is cooled and solidified in the mold, the mold is opened, A resin molding processing method characterized by obtaining a resin molded product to which the metal parts are fixed.