JPH0126422Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to improvement of a mold having a slide core, and is applicable to a mold having an inclined slide core.

[Prior Art] The first explanatory cross-sectional view showing a state in which a resin molded product is molded using a mold having a conventional slide core is shown in FIG.
FIG. 0 shows a perspective view of the main parts of the resin molded product formed using the same method. As shown in FIG. 10, a conventional molding die having a slide core includes a push-up pin (not shown), a slide core 2 that is driven in synchronization with the push-up pin and non-parallel to the push-up pin;
a first split mold 3' that holds the push-up pin and the slide core 2 so as to be relatively movable; and at least one mold surface that, together with the push-up pin, the slide core 2, and the first split mold 3', defines a cavity. It is composed of one second divided mold 4.

Therefore, in the conventional mold, as shown in FIG. 10, the molded product 7', particularly its undercut portion 71', is brought into close contact with the slide core 2 due to its shrinkage force. Therefore, as shown in FIG. 11, in order to release the molded product 7', when the molded product 7' is pushed up using a push-up pin (not shown) and the slide core 2 is driven, the molded product 7' The undercut portion 71' of the slide core 2 cannot be removed from the slide core 2, and the molded product 7' follows the slide core 2, making it impossible to take out the molded product 7'. Further, if the molded product 7' is forcibly removed from the mold, the surface of the molded product 7' will be adversely affected by sink marks, deformation, etc.

[Problems to be solved by the invention] The purpose of the invention is to provide a mold having a slide core from which a molded product can be easily taken out without causing any negative effects such as sink marks or deformation on the surface of the molded product. shall be.

[Means for solving the problems] A mold having a slide core of the present invention has a first
To explain using a typical example shown in the figure, a push-up pin 1, a slide core 2 that is synchronized with the push-up pin 1 and driven non-parallel to the push-up pin 1,
a first split mold 3 that holds the push-up pin 1 and the slide core 2 so as to be relatively movable; the push-up pin 1;
The slide core 2 and the first split mold 3 are composed of at least one second split mold 4 that forms a mold surface that partitions the cavity 5, and the mold surface that partitions the cavity 5 of the push-up pin 1 is The structure includes a parallel surface portion 6 that is substantially parallel to the direction in which the push-up pin 1 is driven, and the molded product formed in the cavity 5 is moved by driving the push-up pin 1 and the slide core 2. When separating from the one-piece mold 3, the movement of the molded product, which is urged by the movement of the slide core 2 in a direction perpendicular to the driving direction of the push-up pin 1, is controlled by the movement substantially parallel to the drive direction of the push-up pin 1. It is characterized in that the slide core 2 is blocked by a parallel surface portion 6 and is movable relative to the molded product.

The essential part of the mold having a slide core of the present invention is that the mold surface defining the cavity of the push-up pin includes a parallel mold surface portion that is substantially parallel to the direction in which the push-up pin is driven.

The "parallel surface portion" refers to a part of the mold surface that partitions the cavity of the push-up pin, and is substantially parallel to the direction in which the push-up pin is driven. When the molded product molded in the cavity is separated from the first split mold,
This prevents the molded product from moving due to the movement of the slide core in a direction substantially perpendicular to the driving direction of the push-up pin. The parallel surface portion has the following aspects, for example.

First, as shown in Figures 1 and 2,
The parallel surface portion 6 can be a part 6 of the circumferential surface of the tip end of the push-up pin 1. That is, the configuration in this case is that the tip end surface of the push-up pin 1 and the first split mold 3
is on the same plane as the mold surface of the first divided mold 3.
The push-up pin 1 may have a concave portion 8 defined by a portion (parallel surface portion) 6 of the circumferential side surface of the tip end thereof.

Second, as shown in FIG. 3, the parallel surface portion 61 can be a peripheral surface 61 at the tip of the push-up pin 1 that protrudes from the mold surface of the first divided mold 31.

Thirdly, as shown in FIG. 4, the parallel surface portion 62 may be a circumferential surface 62 of a recess 82 formed inside the tip of the push-up pin 12.

Fourthly, as shown in FIG. 5, the parallel surface portion 63 can be the outer peripheral side surface 63 of the convex portion 83 formed at the tip of the push-up pin 13.

Parallel surface portions 6, 61, 62 of each of the above embodiments,
The number of concave portions 8, 82 or convex portions 61, 63 including 63 is not particularly limited, and for example, as shown in FIG.
It can be done as one. In this recess 8,
At least one of them may be disposed on the slip-preventable side of the molded product, that is, on the right peripheral end side of the push-up pin in FIG. When these six recesses are provided, the longitudinal drag of the recesses (ribs) can be effectively countered, the plate thickness of the ribs can be reduced, and adverse effects such as sink marks on the surface of the molded product are reduced. Moreover, since the degree of adhesion of the molded product to the push-up pin is small when taking out the molded product, it is extremely easy to take out the molded product.

Further, the cross-sectional shape and thickness of the above-mentioned recesses or protrusions are not particularly limited, but may have a rectangular shape elongated in the sliding direction of the resin molded product, as shown in FIG. 2, for example. Its thickness is usually 0.5-3mm
That's about it. It is preferable that the recesses or projections have a plurality of thinner shapes 8, as shown in FIG. 2, for example.

As the push-up pin, slide core, first split mold, and second split mold used in the mold having a slide core of the present invention, conventionally known ones can be used.

In addition, the cavity shape formed by the first split mold, second split mold, and slide core can be changed depending on the application.
It can be of various types. The degree of inclination between the slide core and the first split mold that holds the slide core is 70 to 95 with respect to the relative movement direction of the first split mold.
Preferably, it is about 100%.

The sliding of the slide core on the first split mold may be driven by a slide pin mechanically using the relative movement of the molds, or by using another driving device such as a hydraulic cylinder. Good too.

The mold having the slide core of the present invention can be mainly used as an injection mold, but can also be used as a mold for compression molding, transfer molding, etc.

[Example] The present invention will be explained below with reference to Examples.

FIG. 1 is a cross-sectional view of a main part of a mold having a slide core of the present invention, and FIG. 2 is a cross-sectional view taken along the line A--A in FIG. 1. Note that FIG. 1 shows a state in which the fixed mold 4, which is the second split mold, the movable mold 3, which is the first split mold, and the slide core 2 are driven to a predetermined mold clamping position, and a cavity 5 of a predetermined shape is formed. show.

This mold holds a push-up pin 1, a slide core 2 that is driven in synchronization with the push-up pin 1 and non-parallel to the push-up pin 1, and allows the push-up pin 1 and the slide core 2 to move relative to each other. A movable mold 3, the push-up pin 1, the slide core 2, and the movable mold 3
and a fixed mold 4 that forms a mold surface that partitions a cavity 5. The slide core 2 is driven by a hydraulic system (not shown).

As shown in FIGS. 1 and 2, the mold surface that partitions the cavity 5 of the push-up pin 1 includes a parallel mold surface portion 6 that is substantially parallel to the direction in which the push-up pin 1 is driven. The tip surface of the pin 1 and the mold surface of the movable mold 3 are on almost the same plane, and the movable mold 3 has a part (parallel surface part) 6 of the peripheral surface of the tip part of the push-up pin 1.
It has six recesses 8 defined by.

Note that the diameter of the one recess 8, the push-up pin 1, and the shape of the cavity 5 are usually selected within the following ranges. That is, the thickness a of the one recess 8 is 0.5 to 3 mm,
The length is 2 mm or more, the depth b is 1 mm or more, the diameter of the push-up pin 1 is 2 mmφ or more, and the shape of the cavity 5 is a flat plate with a constant thickness of 0.5 to 5 mm (height 100 mm, width
100mm or more). Note that the cavity 5 has an undercut forming portion 51 in a part thereof.

In the above state, resin (for example,
ABS resin, PP resin) is injected into the cavity 5.
It is cooled inside and a resin molded product is formed.

Next, as shown in FIG. 6, when the push-up pin 1 and the slide core 2 are driven, the resin molded product 7 first
is separated from the movable mold 3. At the same time, as shown in FIG. 7, the resin molded product 7 follows in the left direction (←) due to the drive of the slide core 2, causing a sliding phenomenon. However, in the six ribs 72 formed on both sides of the push-up pin 1, the right direction (→)
A drag is generated, and this drag is larger than the sliding force, so the resin molded product 7 does not slide to the left.
As shown in FIG. 6, the slide core 2 slips out smoothly from the undercut portion 71 of the resin molded product 7. Then, the resin molded product 7 was easily released from the fixed mold 4, and the resin molded product 7 was separated from the mold. The resin molded product 7 has an undercut portion 71 and six ribs 72, as shown in FIG. Note that the thickness a' of the rib 72 is 0.5
~3.0mm, its height b′ is more than 1.0mm, its length is 3.0
mm or more, and typically each of them is
They are 1.5mm, 3mm, and 10mm.

As described above, the mold having the slide core 2 of this embodiment has six recesses 8 with a small thickness, which are defined by a part (parallel surface part) 6 of the circumferential side of the tip end of the push-up pin 1. . Therefore, if a mold having this slide core 2 is used, the resin molded product 7 formed by the mold will not slip, and the undercut portion 71 will easily fit into the slide core 2.
Since the resin molded product 7 can be easily taken out, the resin molded product 7 has very few negative effects such as sink marks on the surface of the resin molded product 7. Further, since the degree of adhesion of the resin molded product 7 to the push-up pin 1 is small, the resin molded product 7 can be taken out even more easily.

[Effects of the invention] The mold having a slide core of the present invention is capable of relative movement between a push-up pin, a slide core that is synchronized with the push-up pin and driven non-parallel to the push-up pin, and the push-up pin and the slide core. 1st to hold
A mold surface of the push-up pin that is composed of a split mold and at least one second split mold that forms a mold surface that partitions a cavity together with the push-up pin, the slide core, and the first split mold; is characterized in that it includes a parallel surface portion that is substantially parallel to the direction in which the push-up pin is driven.

Therefore, in the mold having this slide core, when the molded product molded in the cavity is separated from the first split mold by driving the push-up pin and the slide core, the push-up pin of the slide core is The movement of the molded product urged by movement in a direction perpendicular to the drive direction is blocked by the parallel surface portion substantially parallel to the drive direction of the push-up pin, and the slide core moves relative to the molded product. is possible.

Therefore, according to the mold having the present slide core, the resin molded product molded by the mold does not slip, and the undercut portion easily comes out of the slide core, making it easy to take out the resin molded product. Moreover, there are extremely few negative effects such as sink marks on the surface of resin molded products. Therefore, a mold having this slide core is extremely convenient for molding resin molded products with severe surface appearance, such as those requiring plating or glossy coating.

In a mold having this slide core, a structure that can easily withstand the operating resistance force of the slide core can be easily fabricated, and since the contact surface with the push-up pin is relatively small, it is easy to take out the resin molded product. There is no decrease in workability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a mold having a slide core showing the mold in a closed state in a normal state in an example. FIG. 2 is a cross-sectional view taken along the line A--A in FIG. 1, and shows a cross-sectional state of the peripheral portion of the parallel surface portion. 3, 4, and 5 are cross-sectional views showing the periphery of the parallel type surface portion showing other aspects, and in FIG. 3, the tip of the push-up pin is the first split type. Fig. 4 shows a state in which the push-up pin has a predetermined concave portion on its tip surface, and Fig. 5 shows a state in which the push-up pin has a predetermined convex portion on its tip surface. . FIG. 6 is a cross-sectional view of a main part showing a state in which the rear push-up pin and the slide core formed by molding the resin molded product in the example are driven. FIG. 7 is a plan view of a main part schematically showing the state of the force applied to the resin molded product when trying to drive the push-up pin and slide core after molding the resin molded product in the example. FIG. 8 is a perspective view of the main parts of the resin molded product manufactured in the example. FIG. 9 is a perspective view of a main part of a resin molded product molded by a conventional mold having a slide core. FIG. 10 is an explanatory sectional view showing a state in which an undercut portion of a resin molded product molded by a conventional mold having a slide core contracts and comes into close contact with the slide core. FIG. 11 is an explanatory sectional view showing a state in which a resin molded product follows a slide core and slides in a conventional mold having a slide core. 1... Push-up pin, 2... Slide core, 3...
First divided mold (movable type), 4... Second divided mold (fixed type), 5... Cavity, 51... Undercut forming part, 6... Parallel surface portion, 7... Resin molded product, 71 ...undercut part, 72...rib,
8... Concavity or convexity.

Claims (1)

[Claims for Utility Model Registration] (1) A push-up pin, a slide core that is driven in synchronization with the push-up pin and non-parallel to the push-up pin, and a first division that holds the push-up pin and the slide core so that they can move relative to each other. a mold; and at least one second split mold that forms a mold surface that partitions a cavity together with the push-up pin, the slide core, and the first split mold, and a mold surface that partitions the cavity of the push-up pin. has a configuration including a parallel surface portion substantially parallel to the direction in which the push-up pin is driven, and the molded product molded in the cavity is moved from the first split mold by driving the push-up pin and the slide core. When separating, the movement of the molded product urged by the movement of the slide core in a direction perpendicular to the driving direction of the push-up pin is blocked by the parallel surface portion substantially parallel to the drive direction of the push-up pin; A mold having a slide core, characterized in that the slide core is movable relative to the molded product. (2) A mold having a slide core according to claim 1, wherein the tip of the push-up pin protrudes from the mold surface of the first split mold, and the circumferential side surface of the tip of the push-up pin constitutes the mold surface. (3) The tip surface of the push-up pin and the mold surface of the first split mold are on almost the same plane, and the first split mold has a recess defined by a part of the circumferential side of the tip of the push-up pin. A molding die having a slide core according to claim 1. (4) The tip end surface of the push-up pin has at least one of a concave portion and a convex portion including a surface substantially parallel to the direction in which the push-up pin is driven. Claim 1 of Utility Model Registration
A mold having a slide core as described in .