JPS61197210A - Insert molding method - Google Patents

Abstract

PURPOSE:To contrive an improvement in design properties of a molded article, by a method wherein holding of a metallic insert is performed by sticking an insert support, which is made of a material showing an external appearance similar to the main body of the molded material, on an insert side in an insert molding. CONSTITUTION:A plurality of pin sticking holes 16 in a keyhole-like state is formed on a part which has been supported by an insert holding pin. As for an insert support 11, it is stuck to an insert 2 by making the same slide to a small diameter side after it has been inserted into the pin sticking hole 16 through a large diameter side. A mud guard is obtained by performing mold release of a high molecular material after the high molecular material has been made to cure by pressurizing and casting the same into a cavity 5 under this state. In this instance, as the insert 2 is floated in an intermediate part by the insert support 11 and is being held under a state incapable of moving, the insert 2 is moved to one side through casting pressure and a matter that it is exposed does not happen.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of molding by injecting a polymeric material under pressure into a mold cavity in which a metal insert is suspended and immovably held in the middle.

(Prior Art) Here, the case of molding a mudguard for an automobile as shown in FIG. 9 will be explained as an example.

A metal insert 2 having an angled cross section is embedded in the mudguard 1 to provide strength to the mounting portion. Conventionally, the molding of this mudguard 1 was performed using an insert 2.
As shown in FIG. 8, the insert is suspended and immovably held in the middle part of the cavity 5 by a plurality of insert holding pins 3.4 protruding from both sides of the cavity surface of the mold, respectively.
In this state, a polymer material such as rubber (EX, EPDM, NBR) or synthetic resin (EX, modified PP, PVC) is injected under pressure into the cavity 5 by injection or transfer, and after hardening, the mold is released. I was doing it.

<Problems to be Solved by the Invention> However, on the design surface of the thus obtained mudguard (molded product) 1, the hole 6.7 of the insert holding pin remains as shown in FIG. Moreover, the metal surface of the insert is exposed through the trace holes 6 and 7, and rust may occur over time, further impeding the design. This tendency is remarkable when the mudguard is painted.

1:::Go-27:222121.9, An insert support made of a material that has the same appearance as the two-body material is fixed to the insert side, and the insert is floated and moved in the mold cavity. The above-mentioned problem is solved by injecting a polymeric material under pressure into the mold cavity while the mold is held in a state where the mold is held in a state that it cannot be held. .

(1) First embodiment (Figs. 1 and 2) This is different from the conventional method in that the polymeric material is injected under pressure into the mold cavity 5 in which the metal insert 2 is held floating and immovably in the middle part. This method is similar to the method of insert molding.

In this embodiment, the insert 2 is held by fixing the insert support 11 to the insert side. and
The insert support 11 has large-diameter first holes on both sides of the shaft portion 12.
It has a shape that includes a support part 13 and a second support part 14, and is made of a material that has the same appearance as the mudguard main body (molded product main body) material (usually the same type of rubber or synthetic resin as the molded product main body material, and the same color). It is colored (colored) and molded by injection, etc. On the other hand, a plurality of keyhole-shaped bottle fixing holes 16 are formed in a portion of the insert 2 that was conventionally supported by an insert holding pin. The insert support 11 is inserted into the pin fixing hole 16 from the large diameter side, and then slid to the small diameter side and fixed to the insert 2. In this state, a polymeric material is injected into the cavity 5 under pressure and cured, and then released from the mold to obtain a mudguard (Jm-shaped product). At this time, when the material is injected, the insert 2 is suspended in the middle part by the insert support 11 and held immovably, so the insert 2 will not be exposed by moving to one side due to the injection pressure. .

In addition, the insert support 11 and the insert 2 are integrated into the molded product body and then released from the mold, and no trace hole for the insert holding pin is formed as in the conventional case.

(2) Second embodiment (Figs. 3 and 4) In the first embodiment, the pin fixing hole 17 formed in the insert 2 is round, and the insert 1 and the support 1
8 is made into a spherical body with a diameter that can be press-fitted into the bottle fixing hole 16. In this case 1, if one of the insert supports 11 has a small diameter and there is a possibility that either wall surface will be pressed due to the flow of the material, change the direction alternately as shown in the illustration. The insert support 18 is secured to the insert 2. Note that this insert support 18
1 is usually molded from a rubber-like elastic material, but it may also be molded from a thermoplastic resin and fixed to the insert 2 by hot caulking.

(3) Third embodiment (Figs. 5 and 6) In the second embodiment, only one side of the insert support 21 is used as a support part, and the other side is a clip leg part 2 having spring elasticity.
2. In this case, the insert support body 21 can be fixed to the insert 2 with one touch using the clip legs, but since the support part is only on one side, it is necessary to alternately change the direction as in the second embodiment. Incidentally, examples of the material having spring elasticity for molding the insert support include polyamide, ABS, PP, and the like.

(4) Fourth Embodiment (FIG. 7) In this example, insert supports 24, which serve as one support portion, are fixed to both surfaces of the insert with an adhesive or the like, without making holes in the insert 2.

<Effects of the Invention> Since the insert molding method of the present invention has the above-described configuration, it produces the following effects.

(a) The insert support, which has the same appearance as the molded product body, is integrated with the molded product body together with the insert and is released from the mold, and the molded product does not have a hole for the insert holding pin as in the past. Therefore, the mudguard When molding is performed by supporting the insert at a design surface area such as this, the design quality of the molded product is improved.

(b) For the same reason as in (a) above, the metal surface of the insert is completely buried, so there is no risk of rust forming on the metal surface and impairing the design (especially for painted products). ).

The method of this invention is not limited to the molding of mudguards, but also assist grips, wheel covers, side moldings,
Of course, it can also be applied to insert molded products such as glove boxes, console boxes, steering wheel pads, and bumpers.

[Brief explanation of drawings]

1 to 7 illustrate the present invention, FIG. 1 is a partial sectional view of the mold showing the holding state of the insert in the first embodiment, and FIG. 2 similarly shows the relationship between the insert and the insert support just before they are fixed. FIG. 3 is a partial sectional view of the mold showing the holding state of the insert in the second embodiment, and FIG.
The same figure is a partial perspective view showing the relationship between the insert and the insert support just before they are fixed, FIG. 5 is a partial cross-sectional view of the mold showing the holding state of the insert in the third embodiment, and FIG. 6 is also a partial perspective view showing the insert and the insert support. FIG. 7 is a partial sectional view of the mold showing the state in which the insert is held in the fourth embodiment; FIG. 8 is a partial perspective view showing the state in which the insert is held in the conventional insert molding method. Figure 9 is a partial cross-sectional view of the molded product obtained by the method shown in Figure 8 (
FIG. 2 is a perspective view of a mudguard. 1...Mudguard (insert molded product), 2...
Metal insert, 5...Mold cavity, 11゜1
8.21.24... Insert support 16.17.
・Pin fixation hole. Patent applicant 1～. -゛Figure 7 @ Figure 8 Figure 9 Procedural amendment (method) 61.3.28 Display of the case 1983, Patent application No. 229071, Title of invention Method of insert molding, Case of person making amendment Relationship with Patent Application Person Address Name Toyoda Gosei Co., Ltd., Agent Date of Amendment Order March 5, 1985 (Shipping Date March 25, 1986)
, "Brief explanation of drawings" column of the specification subject to amendment', Contents of amendment

Claims (1)

[Scope of Claims] A method of forming a metal insert by pressurizing injection of a polymer material into a mold cavity in which a metal insert is suspended and immovably held in the middle part, wherein the metal insert is formed of a material that has the same appearance as the main body of the molded product. A method of insert molding, characterized in that the metal insert is held by fixing a molded insert support body to the insert side.