JPH03222A - Undercut processing structure of injection mold - Google Patents

Abstract

PURPOSE:To dispense with an additional setup at molding and to improve the assembly of a mold in efficiency through a cheap one by a method wherein two or more slide cores and a core insert provided between the slide cores and fixed by a single press plate so as to enable an undercut section to be formed into a mechanical slide structure. CONSTITUTION:Six small protrusions 12 are provided as undercuts in a direction which forms an angle of 45 degrees or so with a parting plane. Four angular pins 4 are used to enable four slide cores 5 and 6 to slide, an angular pin mounting plate 2 is formed into a telescopic structure through three pressure pads 3, and the angular pins 4 and fitted respectively. A core insert 7 is provided between the outer slide core 5 and the inner slide core 6, and a positioning groove is provided to a movable side plate 14. The outer slide core 5 and the inner slide core are so structured that they are made to keep moving by the angular pin 4 and a spring 8 buried in the core opening a mold until the side face of the inner slide core 6 comes into contact with a stopper 9 and the undercut can be drawn out.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an undercut treatment structure for an injection mold that mechanically treats an undercut on a 45° plane of an injection mold. .

[Conventional technology]

When a mold for creative molding has an undercut on a 45° plane, conventionally the undercut was removed by installing a hydraulic cylinder in the 45° direction, but the mold processability, mold dimensions, and molding Due to the problem of setup during molding, avoid the above configuration in advance when designing the molded product, and create a structure in which undercuts are not provided on 456 sides and are attached using screws, etc. I was daring to move forward.

[Problem to be solved by the invention]

The above conventional technology shows that undercuts can be treated by installing a hydraulic cylinder in the mold, but it does not take into account molding processability or setup during molding, resulting in an increase in molded product cost. It was an economic problem. In addition, when it is difficult to use a hydraulic cylinder, consideration is given to the design, and structures such as fitting and screwing are used in the design, resulting in poor assembly work efficiency and an increase in cost.

The present invention does not require extra setup during molding, and
Achieved higher assembly efficiency with inexpensive molding molds.
The purpose is to obtain an undercut treatment structure for an injection mold.

[Means to solve the problem]

The above purpose is to undercut!・Achieved by processing the part with a mechanical sliding structure.

In order to form the undercut portion into a mechanical sliding structure, a plurality of slide cores and a core insert provided between them are fixed by a single holding plate.

[Effect]

In the undercut treatment structure of the present invention, two slide cores slide against one core insert using an angular pin and a spring. At this time, in order to fix the core insert, a groove is carved in the movable template and fixed with one presser plate. As a result, the two sets of slide cores are configured to slide smoothly between the cores and the holding plate, so that the undercut portions are completely removed, and there is no galling of the slide portions, and obstacles to molding are removed.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a front view showing the slide part in a mold-clamped state in one embodiment of the present invention, Fig. 2 is a partial sectional view of Fig. 1 above with the outer slide core removed, and Fig. 3 shows the molded product. In the figure,
(a) is a side view, (b) is a front view, FIG. 4 is a side sectional view of the slide part in the above embodiment, and FIG. 5 is a side sectional view of the slide part after opening the mold. In Figure 1, 5.
6 indicates the outer and inner slide cores, respectively, and the core insert 7
The holding plate 10 and the core 13 are positioned. FIG. 2 shows the slide core portion excluding the outer slide core 5, and clearly shows the positioning state of the core insert 7.

As shown in FIGS. 3(a) and 3(b), the molded product 11 has an approximately 90" mountain-shaped curved shape, and one end thereof is provided with six points at approximately 45 degrees to the parting surface. A small protrusion 12 is provided as an undercut. Therefore, the slide cores 5 and 6 described above are required, but these slide cores 5 and 6 are made of a molded product in which L-shaped shapes are arranged in two rows. Due to the shape, four slide cores must be provided in a narrow space as shown in Fig. 4 or Fig. 5. Fig. 4 shows the slide part in the mold clamping state, and the four slide cores 5 and 6 must be provided. Four angular pins 4 are used to make each slide, but since the template in the fixed example is thick and difficult to machine directly, the angular pins are attached by inserting the plate 2 into the plate 2 using a 3N pressure receiver 3. An angular pin 4 is attached to each of the outer slide cores 5 and 6.A core insert 7 is provided between the outer slide core 5 and the inner slide core 6, but in order to prevent the core insert 7 from moving, The movable side mold plate 14 is machined with a groove for positioning.

While the outer slide core 5 and inner slide core 6 are opened, the side surface of the inner slide core 6 is pressed against the stopper 9 by the angular pin 4 and the spring 8 embedded in the core.
The structure is such that it moves until it comes into contact with the undercut.

As described above, according to the present invention, approximately 4 parts of the parting surface
Since the undercut provided in the 5° direction can be mechanically handled, mold processing problems such as installing a hydraulic cylinder in a narrow space and troublesome setup during molding are eliminated.
Molded products such as decorative frames with decorations at the corners can be molded with a greater degree of freedom in design through simple assembly work without the need for screws that spoil the design.

〔Effect of the invention〕

As described above, the undercut treatment structure for an injection mold according to the present invention is an undercut treatment structure for an index mold in which undercuts are provided in approximately 456 directions of the parting surface. A slide core having a parting shape with approximately 456 sides and consisting of an outer slide core and an inner slide core, a core insert provided between the slide cores, and a slide retainer that also serves as positioning and slide presser. By equipping the parting surface with a plate, it is possible to mechanically handle undercuts in the approximately 45" direction of the parting surface, eliminating the problems that existed in mold processing and the need for setup during molding.
Since the core slide in the direction can be easily performed, the degree of freedom in selection can be expanded in terms of the design of the molded product, and workability in assembling the molded product can be improved.

[Brief explanation of drawings]

Fig. 1 is a front view showing the slide part in a mold-clamped state in an embodiment of the present invention, Fig. 2 is a partial sectional view with the outer slide core removed in Fig. 1 above, and Fig. 3 is an external appearance of the molded product. In the figures, (a) is a side view, (b) is a front view, Fig. 4 is a side sectional view of the slide part in the above embodiment, and Fig. 5 is a side sectional view of the slide part after opening the mold. . 5...Outer slide core, 6...Inner slide core, 7
...Core insert, 10...Slide presser plate, 12...
・Undercut protrusion.

Claims (1)

[Claims] 1. In the undercut treatment structure of an injection mold in which an undercut is provided in the approximately 45° direction of the parting surface, the parting shape is approximately 45°, and the outer slide core and the inner slide core An undercut treatment structure for an injection mold, comprising a slide core made of the same material, a core insert provided between the slide cores, and one slide presser plate that serves both for positioning and slide presser.