JPS6030251B2 - insert mold - Google Patents

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 with an insert embedded in the molded product, it is necessary to install the insert in the mold dividing surface or mold cavity. It is necessary to attach or clamp it to two or more holding parts. On the other hand, in order to obtain these molded products, as is well known, plasticized fluid plastic or the like is injected or press-fitted into the cavity formed by the split mold from one side of the split mold. For this purpose, molded products have injection or press-fit holes (hereinafter referred to as gates).

) marks will always remain. 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 38 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 accuracy of the insert, etc., and as mentioned above, the pressure of the molten resin is high, so even inserts such as iron plates can easily deform. If the insert is the longest, it is best to create undulations in its 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 gate is provided on the part facing the insert, and a support protrusion reaching one side of the insert is provided upright at a position opposite to the gate of the other split mold sandwiching the insert, and the pressure of the molten resin to be press-fit is applied to the support protrusion through the insert. It is in an insert mold that receives the insert and holds the insert in position.

To explain the present invention with reference to the drawings, FIG. 2 is a cross-sectional view taken along the line A-A of the mudguard molding die shown in FIG. Type, 11
indicates an insert.

The insert 11 is approximately plate-shaped, and mounting holes 12 are provided at appropriate locations. The cavity surface 17 of one of the split molds 10 is provided with a protrusion 13 that serves as a holding means for the insert 11, and the other mold 10' is provided with the protrusion 13.
A recess 14 for receiving the protrusion 13 is provided on the cavity surface 17' facing the protrusion 3. In this case, it is preferable to provide a protrusion 13 and a recess 14 corresponding to the mounting hole 12 of the insert 11. Also, in the same figure, in order to position the insert 11 approximately in the middle of the cavity, a seat 15 that is slightly raised from the cavity surface 17 is provided around the protrusion 13, and an annular protrusion 16 is provided around the recess 14 of the other split mold 10'. It is provided. Therefore, the insert 11 is connected to the protrusion 13
When the split molds 10, 10' are closed, the insert 11 is fitted onto the seat 15 and the annular projection 16, and is held and fixed approximately in the middle of the cavity. A gate 18 is provided on the cavity surface 17 of one of the split molds 10 for introducing molten resin into a portion facing approximately the center of the insert 11 to be mounted. In addition, when the insert 11 is plate-shaped, the gate 1
8 is provided facing substantially the center in the middle direction. It goes without saying that this gate 18 communicates with the runner groove and sprue hole shown by broken lines. Reference numeral 19 denotes an insert support protrusion provided on the other cavity surface 17' corresponding to the gate 18, which supports the approximately central portion of the insert 11 in the inner direction, and whose height is set to the height of the insert 11 and the molded cotton. When the top surface is insert 1 1
It is formed so as to come into contact with one side of the.

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 the longest. Also, although only one gate 18 is shown, it goes without saying that a plurality of gates 18 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 introduced through the gate 18, the molten resin is transferred to the insert 11.
The insert 11 collides with one side of the gate 1 under high pressure.
Since the other surface corresponding to the insert 11 is supported by the support protrusion 19, it will not be deformed, and even if the molten resin flowing from the upper surface of the insert 1 to the back surface acts to push up the insert 11, the molding will not occur. During press-fitting of the molten resin, the press-fitted resin is always pressed against the support protrusion 19, so that no deformation occurs.

'Fig. 3 shows an embodiment similar to that of Fig. 2 in which the mounting part of the insert 21 is different from the above-mentioned embodiment.
In place of 2, the insert 21 is provided with a mounting bolt 22.

In this case, the holding recess 23 is formed in one mold 20 corresponding to the bolt 22 of the insert 21, and the holding recess 23 is formed in the other mold 20'.
A holding protrusion 24 may be provided corresponding to the holding recess 23 . Reference numerals 28 and 29 indicate a gate and a support protrusion, respectively, which are provided in the same manner as in the previous embodiment.

Note that the shapes of the support protrusions 19, 29 are designed according to the shapes of the inserts 11, 21, and are not limited to those shown. In addition, the inserts 11 and 21 have appropriate small holes (not shown) in order to improve the bonding with the molten resin.
may be provided. As described above, the present invention provides a gate approximately at the center of the inserted insert in a split mold for integrally molding a molded product including an insert, and the other split mold sandwiching 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 approximately right angles, the insert is supported by the support protrusion on the other surface. Also, during 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.
'A-A sectional view, Figure 3 shows that the mounting part of the insert is the second
Figure 2 is a cross-sectional view of the same machine when different from the one in the figure, Figure 4 A, and the mouth is BB, C- of the split molds 30, 30' showing the method of molding the subordinate column in the product of Figure 1. It is a sectional view of C. Explanation of symbols, 10, 10', 20, 20', 30, 30
'...Divided mold, 11, 21...・Insert, 18, 28...Gate, 19, 29...
...Support protrusion. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. In an insert molding die in which an insert is attached to a cavity of a split mold and the insert and a plastic material to be press-fit are integrally molded, a protrusion that holds the insert when the split mold is closed is provided on the cavity surface of the mold. and an insert characterized in that a concave portion is provided, a gate is provided on a portion of one split mold cavity surface facing the insert, and a protrusion for supporting the insert is provided at a position facing the gate on the other split mold cavity surface. Molding mold.