JPH0436895Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to the structure of a mold for insert molding, and in particular, it is designed to accommodate a wide variety of inserts with different dimensions and to change the setup of inserts in a short time. The present invention relates to an improvement of a mold structure for insert molding suitable for.

[Conventional technology]

The insert molding mold is used to integrally mold resin onto an insert that is previously held within the mold. Insert molds are used to manufacture various products such as bushings for bearings.

For example, a bearing bush 11 as shown in FIGS. 5 and 6 is made by integrally molding a resin 13 with good lubricity such as polyacetal on the inner periphery of a metal cylindrical member 12.

Furthermore, grooves 14 are formed in four places in the integrally molded resin 13 to prevent the resin 13 from separating from the cylindrical member 12 due to molding shrinkage.

By the way, a conventional insert molding die for molding the bush 11 of such a bearing had the following structure.

That is, as shown in FIG. 4, the plate 5 is placed in close contact with the end surface of the insert (cylindrical member) 12 in either one of the movable mold 51 and the fixed mold 52.
3, and the plate 53 was biased toward the other mold side by a disc spring 54.

As a result, even if the height L of the insert 12 varies (approximately 0.4 mm), resin leakage and burrs can be reliably prevented and molding defects can be eliminated.

In addition, 58 is a movable mold (lower mold) main body, 59 is a fixed mold (upper mold) main body, 592 is a stopper, 594 is a tightening bolt, 16 is a sprue, and 18 is a cavity for resin molding.

Such a technique is disclosed in Utility Model Application No. 175929/1983, which was previously filed by the applicant.

For insert parts with normal machining errors, in order to prevent burrs from forming due to resin leakage during molding, the pot is not clamped and fixed between the upper plate and the middle mold, but can be slid up and down by a small distance. By holding the pot at a medium size, there was a technology that allowed dimensional errors in the insert part to escape during mold clamping and to keep the pot in constant contact with the insert part.

For example, such technology was developed in Japanese Patent Application Laid-Open No.
−198215 has arrived.

[Problem that the invention attempts to solve]

However, the conventional insert molding mold 5
0 had the following problems.

That is, the conventional insert molding die 50
is certainly about the height dimension L of the insert 12.
The variation of 0.4 mm and the difference in the outer diameter dimension D could be dealt with by replacing the disc spring 54 and the bush 55.

However, if the inner diameter d of the insert 12 is different, the movable insert 56 and the fixed insert 57 must be replaced.

Conventionally, in order to remove the mold 50 from a molding machine (not shown), the mold 50 had to be disassembled, which caused a problem in that it took a lot of time to change the setup.

Therefore, an object of the present invention is to change the setup of the nest in a short time in response to various types of inserts having different sizes.

[Means for solving problems]

For this reason, the insert molding mold structure according to the present invention will be described with reference to the numbers attached to the drawings. It is characterized by having a structure in which it is fixed by.

Specifically, the cavity 18 formed by the movable mold 51, the fixed mold 52, and the insert 12
In the insert molding mold structure 1 in which the resin 13 is integrally molded into the insert 12 by injecting the resin 13 into the insert mold, a movable side insert 56 that constitutes the movable mold 51 and a fixed mold insert 57 that constitutes the fixed mold 52. are fixed by keys 2 and 4 which are removable from the outside of the insert molding die 1.

[Effect]

To explain the operation of the present invention according to the above configuration, when the mold 1 is open at the parting line (PL), by pulling out the keys 2 and 4 from the mold, the movable side insert 56 and the fixed side insert 57 can be taken out easily.

In addition, contrary to the above, after inserting the movable side insert 56 and the fixed side insert 57, the keys 2 and 4 can be inserted to easily attach and fix.

In this way, nesting can be easily replaced.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a sectional view showing a schematic configuration of an insert molding mold structure according to the present invention, FIG. 2 is a view taken along the - line in FIG. 1, and FIG. 3 is a view along the - line in FIG.
It is a sectional view along a line.

In this example, the same reference numerals are given to the parts that are the same as or correspond to those of the conventional insert molding mold, detailed explanations are omitted, and only the parts that are different from the conventional mold are explained.

The insert molding mold structure 1 includes a movable mold 51
, a fixed mold 52, a movable insert 56, a fixed insert 57, a key 2, and a key 4.

Then, after the insert 12 is resin molded,
From the parting line (PL) side, movable mold 51
The side and the fixed mold 52 side are separated, and then the sleeve 8 is pushed through the knockout pin 6 to be knocked out.

Here, the keys 2 and 4 are inserted into the fixed side nest 57.
and the movable side insert 56 can be replaced while remaining attached to the mold 1, and have a structure that allows them to be attached and removed from the outside of the mold 1.

To explain in more detail using the structure of key 2 as an example,
As shown in FIGS. 2 and 3, the key 2 has a plate shape with the tip side divided into two parts 22. As shown in FIGS.

Then, the key 2 is inserted into the mold 1 at the tip of the bifurcation 22.
A tapered chamfer 24 is formed to facilitate insertion when inserting into the stationary side nest 57.

Note that the same applies to key 4 as well.

To explain the operation of the embodiment according to the above configuration, when the mold 1 is open at the parting line (PL), by pulling out the keys 2 and 4 from the mold 1, the movable side nest 56 and the fixed side nest 57 can be easily taken out.

In addition, contrary to the above, after inserting the movable side insert 56 and the fixed side insert 57, the keys 2 and 4 can be inserted to easily attach and fix.

In this way, the nests 56 and 57 can be easily replaced.

Although specific embodiments of the present invention have been described above, the present invention is not limited thereto, and various other embodiments can be considered by those skilled in the art within the scope of the claims for utility model registration.

For example, in the above embodiment, a tapered chamfer is formed at the tip of the key, but a curved chamfer may be formed instead of a tapered chamfer.

[Effect of idea]

As explained above, the insert molding mold structure according to the present invention has a structure in which the movable side insert and the fixed side insert are fixed by a removable key from the outside of the mold, so it is compatible with many types of inserts with different dimensions. This allows nest setup changes to be made in a short time.

In fact, the time required to change molds has been reduced from 30 minutes to 1/30 of the conventional time.

In addition, since a key is used, it also has the excellent effect of positioning the workpiece.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a schematic configuration of the insert molding mold structure according to the present invention, Fig. 2 is an enlarged view taken along the - line in Fig. 1, and Fig. 3 is an enlarged view taken along the - line in Fig. 2. 4 is a sectional view showing a conventional insert mold, FIG. 5 is a front view showing a schematic structure of a bearing bushing in which resin is integrally molded, and FIG. - is a cross-sectional view along the line. 1...Mold structure for insert molding, 2, 4...
Key, 12...Insert, 13...Resin, 18
...Cavity, 51...Movable type, 52...Fixed type, 56...Movable side nest, 57...Fixed side nest.

Claims (1)

[Scope of utility model registration request] In an insert molding mold structure in which resin is integrally molded to the insert by injecting the resin into a cavity formed by a movable mold, a fixed mold, and an insert, a movable side nest constituting the movable mold; A mold structure for insert molding, characterized in that the fixed side nest constituting the fixed mold is fixed by a key that is removable from the outside of the mold for insert molding.