JPS6250110A - Mold for insert molding - Google Patents

Abstract

PURPOSE:To prevent floating of the insert, by coinciding the projected part of the insert with the axis center when the insert is set and by arranging a chuck rod to be movable back and forth to the axial direction. CONSTITUTION:The insert projection 20a of the set pin 20 for setting the engagement leg part is inserted in the hollow part of the engagement leg part 22 formed on the back surface of the insert 21. The movable mold 1 is then moved to the fixed mold 2 to close the mold and to form a covering type cavity 3, where a molding material is poured. When the mold is closed and a floating plate 15 is moved to the backward direction, the chuck rod 14 moves backward and is energized by the elastic force of the coil spring being set at the bottom part of the chuck rod 14. The top part of the chuck rod thereby pulls the insert 21 to the movable mold side through the engagement leg part 22 and the floating of the insert is thereby prevented.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an insert molding die in which an insert having a protrusion on the back side is set in a movable mold and a covering portion is formed on the front side of the insert. This mold is particularly suitable for insert molding of automobile horn pads, etc.

<Prior art> Conventionally, when insert molding, for example, a horn pad for an automobile, as shown in FIG. The mold is set in the mold 1, the movable mold 1 is moved toward the fixed mold 2, and the mold is closed to form a product cavity, that is, a coating cavity 3, and a molding material (usually a soft This was done by injecting synthetic resin. After the molding material for the coating cavity 3 is cooled and solidified to form the coating 25, the formed amount 26 is protruded by an ejection pin 5 attached to the protrusion plate 4 to perform mold release. Note that 23 is a rib that prevents the formed amount from adhering to the fixed mold side during mold release. Further, 6 is a sprue.

<Problems to be Solved by the Invention> When the insert 21 is set in the movable mold 1, as shown in FIG.

When insert molding is performed while it is raised like this,
The insert 21 may be exposed on the surface of the formed amount, the protruding dimension of the locking leg 22 may be shortened, and in the case of a molded product such as a horn pad, the installation may deviate from the standard dimensions, and the is also a defective product. By the way, the travel distance to activate the horn by pressing the horn pad is usually 1 to 21.
Even if there is an error of about 0.5 cm in the protruding dimension of the locking leg portion 22 of the molded horn pad, the product will be defective.

Means for Solving the Problems〉 As a result of the inventors' earnest efforts in development to solve the above problems, the present inventors set an insert having a protrusion on the back side in a movable type, and The present invention was completed based on the idea that an insert molding die used for forming a covering portion in a mold may have the following characteristic configuration.

A chuck rod is disposed on the movable mold and is capable of reciprocating in the axial direction with its axis aligned with the protrusion of the insert when set.

When the mold is opened, the tip chuck opens, and when the mold is closed,
The tip chuck part closes, chucks the protruding part, and has a mechanism that urges it backward.

<Example> The present invention will be explained in detail based on an example. Portions that are the same as those of the conventional example will be given the same reference numerals and the explanation will be omitted.

As shown in FIGS. 1 and 2, it consists of a movable mold 1 into which an insert 21 is set, and a fixed mold 2 that cooperates with the movable mold 1 to form a coating cavity 3 when the mold is closed. The movable mold 1 is equipped with an extrusion mechanism using an ejection pin 5 attached to an ejection plate 4. Up to this point, the configuration is the same as the conventional example.

On the back side of the movable mold 1, a first spacer 8. Sub-mounting is plate 9. Second spacer 11. and the main attachment are integrally attached at a port 13 in the order of the plate 12.

A chuck rod 14 is disposed on the movable mold 1 so as to be reciprocally slidable with its axis aligned with the locking leg portion 22 of the insert 21 when set. The base of the chuck rod 14 is held in a cavity cut out between the sub-mounting plate 9 and the floating plate 15, and is biased in the backward direction by a coil spring 16. Further, a plurality of push-back pins 17 whose heads are held by the movable plate 15 and whose tips abut against the mating surface of the fixed mold 2 are provided. A coil spring 10 is interposed in a cavity formed by cutting out each other between the floating plate 15 and the main mounting plate 12.

Further, the tip chuck portion of the chuck rod 14 has the third to
As shown in FIG. 4, a plurality of spring claws 18 with bulging tips are arranged radially, and are formed from the large diameter portion 19a to the small diameter portion 19b of the chuck rod holding hole 19 formed in the movable mold 1.
When one bulge 18a at the tip of the spring claw 18 is pulled in, the tip chuck portion is closed.

Furthermore, the center of the chain rod 14 is provided with an insertion protrusion 20a at its tip that is inserted into the hollow of the locking leg 22, and the main attachment point is a locking leg set pin 20 fixed to the plate 12. (See Fig. 1).The stroke amount St in the movable mold l is the gap formed between the floating plate 15 and the main mounting plate 12 in Fig. 1. , the total spring force of coil spring 10 is
The spring force is set to be greater than the spring force of 6.

Next, how the above embodiment is used will be explained.

First, set the insert 21 in the movable mold 1 of the mold (
Figure 1). The insertion protrusion 20a of the locking leg set pin 20 is inserted into the hollow portion of the locking leg 22 formed on the back surface of the insert 21.

At this time, there is no problem even if the insert 21 is lifted from the movable mold 1 as shown in the figure. In addition, the insert material is
It is usually made of hard synthetic resin such as ABS resin or polyamide, but may also be made of metal.

Next, the movable mold 1 is moved in the direction of the fixed mold 2 and the mold is closed to form a covering cavity 3, and a molding material is injected into the covering cavity 3 by injection or the like (FIG. 2). Here, as the molding material, a soft synthetic resin such as soft polyvinyl chloride or soft polyurethane is used.

In the above, when the mold is closed, the push-back pin 17 is
The floating plate 15 is moved backward against the action of the coil spring 10. Then, the compression of the coil spring 16 that has been attached to the base of the chuck rod 14 is released, and the chuck rod 14 is moved and biased in the backward direction by the spring force. Then, the tip bulging portion 18a of the spring claw 18 is drawn into the small diameter portion 19b of the chuck rod holding hole and closes, and the tip chuck portion chucks the undercut portion of the locking leg portion 22. Part 22
The insert 21 is pulled toward the movable mold side through the insert 22, and the insert 22 is no longer lifted up. In this state,
Since the material is injected, defects in the molded product that occur when insert molding is performed with the insert floating as in the conventional method no longer occur. Further, in the above, since the insertion convex portion 20a of the locking leg set pin 20 is inserted into the hollow part of the locking leg 22, the locking leg is prevented from being crushed, and the locking leg 22 is chucked. and ensure retraction.

Subsequently, after cooling and solidifying the molding material in the coating cavity 3, the mold is opened as in the past, and the ejector bottle 5 is removed.
Before the molded product is ejected in this mold opening process, in which the molded product 26 is ejected and released, the floating plate 15 resists the spring force of the coiled spring 16 by the action of the coil spring 18, and the sub-mounting is prevented. It is pressed against the plate 9 and returns to the state shown in FIG. 1, and the chuck claw 18 of the tip chuck portion of the chuck rod 14 opens to release the chuck of the locking leg portion 22. Therefore, during demolding, the locking leg portion 22 will not be damaged due to forceful removal or the like.

In the above embodiment, the driving force for retracting and pushing back the chuck rod 14 is obtained by the coil spring 10°16, but the driving force may be obtained by directly connecting the chuck rod 14 to the cylinder rod. Furthermore, if the locking legs of the insert are of a hollow type, the locking leg set bin is, of course, unnecessary.

Furthermore, when the protruding part of the insert is a disposable leg part 24 that may be damaged as shown in FIG.
A blade part 28b is formed on the inside of the blade part a, and is configured to bite into the sacrificial leg part 24.

In addition, if the insert is large or has a three-dimensional curved surface and has many parts that tend to lift up, it is necessary to form multiple disposable legs on the back side of the insert and correspondingly arrange multiple chuck rods on the movable mold. It is desirable to set up

<Operations and Effects of the Invention> In the insert molding mold of the present invention, when the insert is set floating in the movable mold, the protruding parts such as the locking legs formed on the back side of the insert will not move when the mold is closed. Since the insert is chucked by the chuck rod and pulled and biased toward the movable mold side, lifting of the insert is surely eliminated.

Since the material is injected into the covering portion in this state, defects in the molded product that occur when insert molding is performed with the insert floating, as in the conventional method, do not occur.

[Brief explanation of the drawing]

Figures 1 to 5 illustrate the present invention, Figure 1 is a schematic cross-sectional view of the main part showing an example of an insert molding mold just before mold closing, and Figure 2 shows the injection of material in the mold shown in Figure 1 at the time of mold closing. A schematic sectional view of the main part after completion, FIG. 3 is a plan view showing an example of the chuck rod,
Fig. 4 is a plan view of the tip chuck part taken along the line ■-■ in Fig. 3, Fig. 5 is a sectional view of the main part showing another aspect of the tip chuck part of the chuck rod, and Fig. 6 is the insert in the conventional example. FIG. 7 is a schematic sectional view of the molding die when the mold is closed, and FIG. 7 is a schematic sectional view when the mold is opened. DESCRIPTION OF SYMBOLS 1... Movable type, 2... Fixed type, 3... Covering cavity, 8... First spacer, 9... Sub-mounting plate, 10... Coil spring, 11... 2nd spacer, 12... Main mounting plate, l4... Chuck rod, 15... Floating plate, 16... Coil spring, 17... Push back pin, 18.28... Spring claw, 21... Insert, 22... Locking leg (protrusion), 24... Disposable leg (protrusion), 25... Covering part. 26... Molded product. Patent applicant

Claims (1)

[Claims] An insert molding die used for setting an insert having a protrusion on the back surface side in a movable mold and forming a covering portion on the front side of the insert, wherein the protrusion part of the insert when set in the movable mold. A chuck rod is disposed that can reciprocate in the axial direction with the axis aligned with the chuck rod, and when the mold is opened, the tip chuck portion is open, and when the mold is closed, the tip chuck portion is closed. A mold for insert molding, comprising a mechanism for chucking the protrusion and urging it backward.