JPS61273920A - Injection molding of molded product embedded with insert - Google Patents

Abstract

PURPOSE:To provide the injection molding method of molded product embedded with the insert by a method wherein a core, consisting of a magnetic body,is fitted to the protruding section of the insert to attract the core to a magnet, fixed to a metallic mold, and fix the insert to the wall surface of the mold through the core while resin is injected into the cavity of the mold to mold the product, then, the product is released from the mold together with the core and, thereafter, the core is removed out of the insert. CONSTITUTION:The upper and lower metallic molds 31, 32 are opened and the core 2 is inserted into a recess 4 provided at a proper place in the wall surface of the mold to attract the core 2 to the magnet 5. The insert 1 is fixed to the wall surface of the mold through the core 2 in such a manner, thereafter, the molds are clamped and resin is injected into the cavity 30 through a gate. Subsequently, the upper and lower metallic molds 31, 32 are opened after waiting the curing of the resin injected into the cavity 30 and the core 2 is taken out of the mold together with the molded product. Then, the core 2 is removed from the insert 1 and the molded product, in which a part of the insert 1 is projected out of the molding surface, may be obtained.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an injection molding method for molded products in which inserts are embedded, and in particular, inserts in which a portion of the molded product protruding from the molding surface is undercut, or non-magnetic materials. This invention relates to an injection molding method suitable for embedding an insert consisting of a molded product into a molded product.

(Prior Art and its Problems) A method of manufacturing a molded product in which an insert is embedded by injection molding is conventionally known.

Generally, when manufacturing a molded product in which a part of the buried insert protrudes from the molding surface, a recess is provided in the wall of the mold constituting the cavity, and the protruding part of the inner is inserted and fixed into the recess. , molding was carried out by injecting resin into the mold main 11 bit.

When the insert is made of a magnetic material such as metal, a magnet is fixed to the inner part of the four parts provided on the wall of the mold, and a fixing means is used to attract the insert to the magnet. In addition, when the insert is made of a non-magnetic material such as plastic, the insert is fixed in the recess using an adhesive.

■ However, in the case of any of the fixing means mentioned above, the part protruding from the surface of the molded product will be subject to under-force.
The resulting insert (the insert shown in Figure 1)
(see cert) could not be fixed to the mold wall. In addition, if the insert is small, the diameter of the four holes into which the insert is inserted will also be 1.1, which means that the injection pad will not fit into the mold cavity.
There is a problem in that when the resin gets into the gap between the recess and the insert and is soldered, the work to remove this resin is extremely troublesome.

Furthermore, the insert made of the latter non-magnetic material is recessed and
When inserting the rod into the recess and fixing it with adhesive, use the inner rod of the recess.

-However, the disadvantage is that the molding cycle is extended because the adhesive that has stuck to it must also be removed.
Ivy.

(Means for Solving the Problems) The present invention involves fitting a placing core into a protrusion of an insert protruding from the surface of a molded product, while fitting the placing core into an appropriate position on a mold wall surface constituting a cavity. A matching recess is provided and a magnet is fixed deep inside the recess. Then, a placing core is inserted into the recess and attracted by a magnet, and the insert is fixed to the wall surface of the mold via the placing core.

Next, after injecting resin into the mold cavity to form a molded product, the mold is opened, the core is taken out together with the molded product, and the core is removed from the insert.

The molding method of the present invention includes a normal injection molding method in which a molded product is obtained by injecting a molten resin such as vinyl chloride resin into a cavity, a foam molding method using a foamable resin, and a rim molding method using a urethane resin or the like. applicable to any law,
Inserts embedded in molded products can be used regardless of whether they are magnetic or not, and regardless of their shape.

Note that the part protruding from the surface of the molded product may be under-forced.
When burying the inner that has become a cut, the minute p<
:(Use a breakable core and attach the core to a magnet.
To ui, Pal: 1゛ It is best to fix the insert to the mold wall without suction.

17゜-1・1 ゛′ Shiba: ゛ (Example) 1%1. lj Hereinafter, the specific configuration of the present invention will be explained in detail with reference to the drawings.

(Figure 1 is a cross-sectional view of the main parts of the molding process showing one embodiment of the present invention, in which the reference numerals 1 and 2 are
, ′ ・j゛ Placement core, 3 is the mold.

The insert 1 is made of a magnetic material such as iron, or a non-magnetic material such as positive,
, Pa An under force is provided on the protruding portion that protrudes from the surface of the molded product.

On the other hand, the core 2 is made of a magnetic material such as iron. The protruding portion of the insert 1 is attached to this core 2.
.

□ is provided with a recess 21 into which it fits, and can be divided.
・It is shaped like a ring with a single bottom. Also,
The insert 1 is placed around the opening of the recessed portion 21.
A sealing member 6 that comes into close contact with the housing is attached.

The mold 3 is composed of an upper mold 31 and a lower mold 32,
The upper and lower molds 31 and 32 form a cavity 30 that matches the desired molded product. A recess 4 into which the core 2 fits is provided at an appropriate location on the wall of the mold, and a magnet 5 is fixed at the back of the recess 4.

In the molding method of the present invention, first, the upper and lower molds 31.3
2 is opened, and the core 2 is inserted into a recess 4 provided at an appropriate position on the wall of the mold and is attracted to a magnet 5. After the insert 1 is fixed to the wall surface of the mold through the core 2 in this manner, the mold is clamped and resin is injected into the cavity 30 from a gate (not shown).

Next, after waiting for the resin injected into the cavity 30 to harden, the upper and lower molds 31 and 32 are opened, and the core 2 is taken out together with the molded product.

Therefore, when the core 2 is removed from the insert 1, a molded product with a part of the insert 1 protruding from the molding surface is obtained.

(Operations and Effects of the Invention) The molding method of the present invention fixes the insert to the wall of the mold through a core made of magnetic material, so regardless of the material of the insert, the insert can be securely attached to the wall of the mold. Can be fixed. Furthermore, when embedding an insert with an undercut in the part protruding from the surface of the molded product, using a splittable core allows the insert to be reliably fixed to the mold wall surface.

Furthermore, when embedding a small insert in a molded product, if the hole diameter of the recess into which the core fits is made large, even if the resin gets into the space between the recess and the core, the inner surface of the recess is prevented. Even if resin adheres, this resin can be easily removed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a molding process showing an embodiment of the present invention.

Claims (1)

[Claims] 1. When injection molding a molded product in which a part of the buried insert protrudes from the molding surface, a core made of a magnetic material is fitted into the protruding part of the insert, and a cavity is formed. A recess into which the placing core fits is provided at an appropriate location on the wall surface of the mold, and a magnet is fixed at the back of the recess, and the placing core is inserted into the recess so that it is attracted to the magnet, and the placing core is inserted into the mold through the placing core. After fixing the insert to the wall of the mold, injecting resin into the mold cavity to mold the molded product, then demolding the mold, taking out the core together with the molded product, and removing the core from the insert. An injection molding method for molded products with embedded inserts characterized by 2. Claim 1, characterized in that the insert is fixed to the wall surface of the mold via the insert using a splittable core having a recess into which the protrusion of the insert fits. An injection molding method for molded products with embedded inserts.