JPS588607A - Mold for insert molding - Google Patents

Abstract

PURPOSE:To obtain a precisely molded product, by providing a gate for an insert at one split mold and a protruded part which supports the insert at a position corresponding to said gate at a cavity face of another split mold on an insert attaching mold. CONSTITUTION:On split molds 10, 10' by which a molded product containing an insert 11 is molded integrally a gate 18 is provided about a center of the insert 11 to be attached and also a protruded part 19 supporting the insert is provided correspondingly to the gate 18 at a cavity face of another split mold which puts the insert 11 between. Though a molten resin which is forced in molding collides with the insert almost at a right angle, the insert is supported by the protruded supporting part at another face and deformation and displacement of the insert are prevented in such a way, and the molded product of which the insert is held at a predetermined position can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold for molding plastics such as plastics and rubber, and more particularly to a mold for molding plastics having built-in inserts such as mounting fittings.

Conventionally, molded products such as plastic and rubber have been used for various products, but especially for molded products that need to be attached or fixed to other objects, such as automobile mudguards, reinforcing cores are used. A type in which the body or mounting hardware is integrally molded is used.

By the way, these reinforcing core bodies or mounting metal fittings (generally called inserts, hereinafter referred to as inserts)
has various shapes depending on the product or the structure of the product, but especially when obtaining a molded product in which the insert is embedded in the molded product, the insert is placed in the mold parting surface or in the mold cavity. It is necessary to attach or clamp it to more than one holding part.

On the other hand, in order to obtain these molded products, plasticized plastic in a fluid state is injected or press-fitted from one side of a well-known nine-part mold into the cavity formed by the divided mold. but.

Therefore, traces of the injection or press-fit holes (hereinafter referred to as gates) will always remain on the molded product. Therefore, this gate position is usually set in a place that is as inconspicuous as possible, such as the back or side ridgeline of the molded product, but when molding a molded product to which an insert is attached, the gate position makes it difficult for the insert to be press-fitted. It may be deformed or displaced by the applied resin pressure.

For example, in the case of a molded product in which a plate-shaped insert 11 for mounting a mudguard or the like shown in FIG. 1 is buried, a gate 68 shown in FIG. However, since the molten resin is press-fitted at high pressure and high speed, the insert 11 becomes an obstacle as shown in FIG. , the flow becomes more complicated. Therefore, the pressure applied to both sides of the insert changes depending on the mounting position of the insert, the precision of the insert, etc., and as mentioned above, the pressure of the molten resin is high, so even inserts made of iron plates etc. can easily deform. When the insert is long, corrugations often occur in the longitudinal direction.

Therefore, the present invention aims to provide a molding die that can eliminate the above-mentioned drawbacks when obtaining such an insert molded product. A support protrusion that reaches one side of the insert is erected on the mold cavity surface corresponding to the gate position,
The insert molding die receives the pressure of the molten resin press-fitted through the insert at the supporting protrusion and holds the insert in a fixed position.

To explain the present invention based on the drawings, FIG. 2 is an excerpted A-All sectional view of the metal view for molding the mudguard of FIG. 1, which is an embodiment of the present invention, and 10. type, 1
Reference numeral 1 designates an insert. The insert 11 is generally plate-shaped and has mounting holes 12 provided at appropriate locations on the front side.

Insert 1 is placed on the cavity surface 17 of one split mold 10.
The mold 1 is provided with a protrusion 16 serving as a holding means, and the other mold 1 is provided with four parts 14 on the cavity surface 11 facing the protrusion 16 to receive the protrusion 16.

In this case, it is preferable to provide the protrusion 16 and the four parts 14 corresponding to the mounting hole 12 of the insert 11, and in the same figure, in order to position the insert 11 approximately in the middle of the cavity, A seat 15 is provided that is slightly raised from the cavity surface 17, and an annular projection 16 is provided around the recess 14 of the other split mold 10'. Therefore, the insert 11 is attached to the protrusion 11, and the split mold 10.10'
When the insert 11 is closed, the insert 11 is sandwiched between the seat 15 and the annular projection 16, and is held and fixed approximately in the middle of the cavity.

Reference numeral 18 denotes a gate for press-fitting the molten resin into the cavity, and is open toward approximately the center of the insert 11. It goes without saying that this gate 18 communicates with the runner groove and sprue hole shown by broken lines.

19 is the other cavity surface 1 corresponding to the gate 18
7', which supports the approximate center of the insert 11 in the width direction, and whose height is such that when the insert 11 is installed and the mold is clamped, its top surface touches one side of the insert 11. It is formed so that it touches. Although only one insert support protrusion 19 is shown in the figure, a plurality of insert support protrusions 19 may be provided if the insert 11 is held for a long time, that is, if the insert is long.

Also, although only one gate 1B is shown in the figure, it goes without saying that a plurality of gates 1B may be provided at predetermined intervals in the longitudinal direction of the insert. When a plurality of gates 18 are provided, at least the same number of support protrusions 19 are provided correspondingly. In other words, the number of support protrusions 19 may be greater than the number of gates 18.

Therefore, when molten resin is press-fitted through the gate 18, the molten resin collides with one side of the insert 11 under high pressure, but the other side of the insert 11 that corresponds to the gate 18 is connected to the supporting protrusion 1.
? Since the insert 11 is supported by Therefore, the support protrusion 1
9, so that no deformation occurs.

FIG. 6 shows an embodiment similar to FIG. 2 in which the mounting portion of the insert 21 is different from the above embodiment, and the mounting hole 12 is
Instead, the insert 21 is provided with a mounting bolt or the like 22. In this case, one mold 20 may be provided with a holding portion 26 corresponding to the bolt 22 of the insert 21, and the other mold 20 may be provided with a holding protrusion 24 corresponding to the holding recess 26. .29 indicates a gate and a supporting protrusion, respectively, which are provided in the same manner as in the previous embodiment. In addition, support protrusion 19.29
The shape is designed according to the shape of the inserter) 11.21 and is not limited to that shown in the drawings.

The inserts 11.21 may also be provided with appropriate small holes (not shown) to facilitate bonding with the molten resin.

As described above, the present invention provides a gate approximately at the center of the insert to be mounted in a split mold for integrally molding a molded product including an insert, and the other split mold that sandwiches the insert in correspondence with the gate. Since the insert support protrusion is provided on the mold cavity surface, even if the molten resin press-fitted during molding collides with the insert at a substantially right angle, the insert is supported by the support protrusion on the other surface.
During fork molding, the insert is always pressed against the support protrusion by the press-fitted resin, which prevents deformation and displacement of the insert, making it possible to obtain a molded product in which the insert is held in a predetermined position. .

[Brief explanation of drawings]

FIG. 1 is a front view of a mudguard according to an embodiment of the present invention, and FIG. 2 is a split mold 10.10 for molding according to the embodiment of FIG. 1.
° A-A cross-sectional view, Figure 6 shows that the insert mounting part is the second
A sectional view similar to Fig. 2 in a case different from the one in the figure, Fig. 4 (A-X opening) shows the conventional molding method for the product in Fig. 1, B-E, C of the split mold 60.60° -C sectional view. Explanation of symbols 10.10', 20.20', 30.30'...
Split mold 11.21...Insert 18.28...Gate 19.29...Support protrusion

Claims (1)

[Claims] In the molding die in which the insert is mounted, a gate for the insert is provided in one of the split molds, and an insert support protrusion is provided at a position corresponding to the gate on the cavity surface of the other split mold that sandwiches the insert. Characteristic insert mold.