JPH0747575A - Device for dealing with undercut release for protrusion - Google Patents

Abstract

PURPOSE:To easily deal with release of undercut having small irregularity by radially opening/closing a split mold which forms outline of a protrusion as a molded piece by a conical taper in a fixed pin so as to release the undercut having small irregularity. CONSTITUTION:After a molded piece 1 and a joint short tube 12 are molded, a mold 7 of a moving side plate is separated and moved downward from a fixed side plate 3, and a holder 15 is moved together with the mold 7 by a compression coil spring 23. Then, an open/close transfer pin 20 planted in the holder 15 is relatively guided by a comical taper 18 of an opening/closing fixed pin 16 in a fixed state so as to be expanded diametrically. As a result, a diameter of an outline split mold 14 is also expanded, and particularly a diameter of an undercut 2 is also expanded. Further, when the mold 7 separates and moves, the separating movements of the holder 15 and the expanded outline split mold 14 stop. Successively, the mold 7 moves, so that the undercut 2 is entirely released.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an undercut mold release processing device for a projecting portion having an undercut portion on the outer circumference, and more specifically, an undercut of a plurality of pipes arranged in parallel and having an undercut portion on the entire circumference. The present invention relates to a cut release processing device.

[0002]

2. Description of the Related Art Generally, undercutting in an injection molding die means that when a molded product is taken out from the die,
It refers to the uneven part of the mold that interferes, and therefore a molded product with an undercut part cannot be molded only by a structure in which the mold moves in the mold opening direction of the molding machine, so a complicated mechanism for the mold. Is provided to perform mold release processing of the undercut portion.

A typical example of such a mold release processing apparatus is a slide core type mold release processing apparatus, which uses an entire cavity or a slide core obtained by dividing a die of an undercut portion into a movable structure. There is. As a means for moving the slide core, there are a method of using a mold opening force and a method of using an operating cylinder. However, a method of using a mold opening force via an angular pin (fixing pin) is very general. Has become.

An undercut mold release processing device utilizing the mold opening force through the angular pin will be described.

In FIG. 5, the underside is formed on the outer periphery of the molded product 1.
If the cut portion 2 is provided, the fixed side plate 3 is provided with the angular pin 4 inclined, and the slide core 5 having the angular pin 4 as a cam is connected to the guide rail (not shown) of the movable side plate 6. (Shown). This slide core 5
Is the outer mold of the undercut portion 2.

That is, since the angular pin 4 slidably penetrates through the slide core 5, the movable plate 6 is moved.
When the mold 7 is opened, the slide core 5 is guided by the angular pin 4 and moves in the direction of the arrow a to release the undercut portion 2. In FIG. 5, 8 is a locking block, 9 is a mold provided on the fixed side plate 3, and 10 is a mold.
Is a fixed side mounting plate, and 11 is a pin insertion hole.

However, in the device for moving the slide core 5 by using the angular pin 4 and releasing the mold, the structure is simple and the operation is reliable, but when there are a plurality of undercut parts 2 adjacent to each other, There were the following problems.

That is, when two or more cylindrical protrusions are provided in parallel on the same surface and there is an undercut portion on the outer periphery of each of these protrusions, the slide cores are moved by the angular pins with respect to each other. There is a problem that the slide core cannot be used due to the interference, and for that purpose, the method of forcibly removing the die of the undercut portion after the molding is adopted. Therefore, there is a problem that the quality of the product deteriorates due to the excessive removal of the undercut portion.

Further, if a large number of cylindrical protrusions having an undercut portion on the outer periphery are arranged side by side, it is impossible to force the punching, and the molded product and the cylindrical protrusions are separately molded. Then, they are welded together.
Therefore, in such a method of separately molding and fixing,
There was a problem that production cost and time were required.

[0010]

SUMMARY OF THE INVENTION Therefore, the present invention has been made in order to solve the above-mentioned various problems, and the gist of the present invention is to provide a protrusion having a small uneven undercut portion on the outer periphery. In an undercut mold release processing apparatus for parts, an outer mold for molding the outer shape of the protruding portion is formed into a plurality of split molds that open and close in a radial manner, and the split molds are used as fixed side plates. In the undercut mold release processing device for a protruding portion, the conical taper portion of the provided fixing pin is used to open and close while utilizing the mold opening force.

[0011]

The present invention will be described in detail with reference to the embodiments shown in the accompanying drawings. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is FIG.
3A to 3D and 4A to 4C are operation explanatory views of FIG. 1, and the same parts as those of the conventional example shown in FIG.

The product molded by the undercutting apparatus of this embodiment is a synthetic resin case for accommodating air filters, dampers, etc. used in automobile engines and the like. the flat surface, Dakutoho - scan (e.g., 20 ^mm φ~60 ^mm φ ones) joint short pipe for connecting is provided. Then, on the outer peripheral surface of the joint short pipe, a hose retaining projection (for example, a height of 1 ^mm to
2 ^mm ) is formed, and a plurality of joint short pipes are arranged side by side. Therefore, the hose retaining projection forms an undercut portion, and
Since a plurality of them are arranged side by side, it is impossible to apply a slide core type mold release processing device using a normal angular pin.

Therefore, in FIG. 1 and FIG. 2, a flat shoulder portion 1a is formed on the molded article 1 to be the case, and a duct hose (not shown) is connected to the shoulder portion 1a. A joint short pipe 12 for standing is provided upright. Around the outer circumference of the joint short pipe 12, there is provided a projection for preventing the duct hose from coming off. That is, this forms the small concave-convex undercut portion 2. Therefore, the underside of the molded product 1 and the joint short pipe 12
The following mold release processing device is used for mold release after the cut portion 2 is injection molded.

That is, the joint short tube 12 is formed by the cylindrical inner mold 13 and the outer shape split mold 14. More specifically, an insertion hole 21 is formed in the fixed plate 3, and a pipe-shaped holder 15 is inserted into the insertion hole 21 so as to be slidable in the axial direction. The tip side of the holder 15 is formed in the cylindrical inner mold 13.

A fixing pin 16 for opening and closing, which corresponds to a conventional general angular pin, is provided through the center of the holder 15. A guide portion 17 is formed at the tip of the open / close fixing pin 16, and a conical taper portion 18 having a gradually reduced diameter is formed following the guide portion 17. A shaft portion into which a compression coil spring 23, which will be described later, is inserted is formed subsequent to the conical taper portion 18, and a tightening bolt 19 is screwed onto the pin base portion. The open / close fixing pin 16 is fixed to the fixed plate 3. Therefore, the opening / closing fixing pin 16 is slidably inserted in the holder 15 in the axial direction.

A cavity 2 for molding the joint short pipe 12 and the undercut portion 2 is provided in the outer shape split mold 14.
a (particularly, refer to FIG. 4) is provided, but the outer shape split mold 14 is radially divided into four as shown in FIG. 2, and the base (cavity 2a) of each split mold 14a is divided.
The pin implantation portion 2b (see FIG. 1) is formed in a portion other than the above), and the opening / closing transmission pin 2 is formed in this pin implantation portion 2b.
The tip of 0 is in contact with the conical taper portion 18,
When the taper diameter changes, the outer shape split mold 14 opens and closes. The outer peripheral surface of the outer shape split mold 14 is formed in a conical shape, and is closely fitted to the conical inner surface of the insertion hole 21 (see particularly FIG. 4) formed in the fixed plate 3.

A spring receiving hole 2 is provided at the end of the holder 15.
2 is perforated, and the spring receiving hole 22 and the insertion hole 2
A compression coil spring 23 externally fitted to the opening / closing fixing pin 16 is housed between the compression coil spring 23 and the inner end surface of 1.

Next, the operation of this embodiment will be described. Molded product 1
When the joint short tube 2 is molded, the movable side plate 6
The mold 7 (see FIG. 5) is moved away from the fixed plate 3 in the b direction, that is, the mold is opened. At that time, holder-15
Is the movable plate 6 due to the elasticity of the compression coil spring 23.
Since it is pressed against the mold 7 of No. 6, it moves together with the mold 7 of the movable plate 6. On the other hand, since the opening / closing fixing pin 16 is fixed to the fixed plate 3, the opening / closing transmission pin 20 implanted in the holder 15 is guided to the conical taper portion 18 of the opening / closing fixing pin 16. The diameter is increased. as a result,
The outer shape split mold 14 is also expanded in the direction c of FIG. 2, and in particular, the undercut portion 2 is also expanded (see FIG. 3).

Further, since the die 7 of the movable plate 6 is moved away from the movable plate 6, the compression coil spring 23 comes close to the free height, and the holder 15 and the expanded outer shape split mold 14 are moved away from each other. Stops (see FIG. 4). Subsequently, the mold 7 of the movable plate 6 moves, so that the undercut portion 2 is completely released.

Although the present embodiment has been described with a circular joint short pipe, the present invention is not limited to this, and it may be a square pipe or a solid protruding portion.

[0021]

According to the present invention, the conical taper portion of the fixing pin radially opens and closes the split mold for molding the outer shape of the protruding portion, which is a molded product, to form a small concave-convex undercut portion. Unlike the slide core, it does not take up a space for opening and closing since it is released from the mold. Therefore, it is possible to perform the release process of the small concave-convex undercut of the juxtaposed protrusions or the protrusions erected along the wall surface. .

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line A of FIG.

FIG. 3 is an operation explanatory view of FIG. 1.

FIG. 4 is an operation explanatory view of FIG. 1.

FIG. 5 is a conventional example.

[Explanation of symbols]

1 ... Molded product, 2 ... Undercut part, 3 ... Fixed side pre-
G., 14 ... Outer part split type, 16 ... Opening / closing fixing pin, 18 ...
Conical taper part

Claims (1)

[Claims] 1. An undercut mold release processing apparatus for a protrusion having a small unevenness-shaped undercut on the outer periphery, wherein a plurality of outer dies for forming the outer shape of the protrusion are opened and closed in a radial manner. The projection is characterized in that the split mold is configured to be opened and closed by utilizing the mold opening force by the conical taper portion of the fixing pin provided on the fixed plate. Under-cut mold release processing equipment.