JPH01221209A - Transverse hole molding process in resin molding - Google Patents

Abstract

PURPOSE:To contrive to simplify a mold structure by a method in which two projected parts are mutually lapped by clamping a core mold and a cavity mold, and the transverse hole crossing at right angle in the mold clamping direction is molded in the part where said two projected parts are mutually lapped. CONSTITUTION:The tip part of the projected part 12 of the core 100 side of a top force 10 has a semicircular shape, and the tip part of the projected part 13 of the cavity 110 side of a bottom force 11 has the mold-opening structure of semicircular square shape. The top force 10 and the bottom force 11 are clamped, and the projected part 12 of core side and the projected part 13 of cavity side form respectively the recessed part corresponding to the projected shape inside and outside in wall thickness direction, and then said tip parts are mutually lapped. Next, molten resin is injected and packed into the space formed by the core part 100 and the cavity part 110. Then after the resin has been cured under cooling in cooling process, the top force 10 and the bottom force 11 are opened respectively upward and downward. The transverse hole 24, penetrating transversely the side wall 21, is molded in the part where the projected part 12 of core side and the projected part 13 of cavity side are mutually lapped in the shape of a reverse key hole.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for forming a horizontal hole in resin molding, in which a horizontal hole perpendicular to the mold clamping direction can be formed by only the opening operation of the mold clamp.

2. Description of the Related Art In recent years, molded products formed by resin injection molding have been widely used, including printer frames and the like. Many of these molded products have horizontal holes in a direction perpendicular to the clamping direction of the mold.

For example, as shown in FIG. 4, a frame 1 of a printer 1 has a support hole 2 formed in a side wall for supporting a shaft or the like.

In this way, when forming a horizontal hole 2 such as a support hole in the side wall IA of a molded product 1 such as a frame of a printer, as shown in FIG. A mold was formed.

During molding, after the core mold 5 and the cavity mold 6 are vertically matched, the slide piece 7 is laterally matched. After clamping the mold, when injecting the resin into the space formed by the core mold 5, the cavity mold 6, and the slide piece 7, control is performed to press the slide piece 7 from the side in addition to vertical pressing control. will be held.

On the other hand, when opening the mold, first, the slide piece 7 is pulled out laterally, and then the core mold 5 and the cavity mold 6 are opened in the vertical direction. In this way, a horizontal hole was formed in a direction perpendicular to the mold clamping direction.

Problems to be Solved by the Invention In the conventional method for forming a horizontal hole as described above, a slide piece 7 for forming the horizontal hole is required in addition to the core mold 5 and the cavity mold 8. As a result, the structure of the mold becomes complicated and there is a drawback that it becomes difficult to use.

In addition, when molding, it is necessary to control the movement of the mold in at least two directions: the mold clamping/mold opening direction of the core mold 5 and the cavity mold 6, and the mold clamping direction of the slide piece 7. The molding process and the control of the molding operation are complicated and difficult to handle, and the process operation takes time.

The present invention was proposed in view of the above points, and an object of the present invention is to provide a method for forming a horizontal hole that can easily form a horizontal hole perpendicular to the mold clamping direction by only mold clamping and mold opening operations in the - direction. There is.

Means for Solving the Problems In order to achieve the above object, the present invention forms a convex portion having one side shape that forms a hole shape on the side wall of the core mold, and also forms a convex portion having a shape on one side that forms a hole shape on the side wall of the cavity mold. forming a convex portion having a shape on the other side, and overlapping the two convex portions by clamping the core mold and the cavity mold;
A feature is that a horizontal hole orthogonal to the mold clamping direction is formed in the overlapping portion of these two convex portions. The two convex portions are overlapped on the inside and outside in the wall thickness direction, and the two convex portions overlap each other to form a hole shape with substantially equal wall thickness in one direction and the other direction in the mold clamping direction. The two convex portions are formed as separate pieces or integrally formed, and are overlapped on the inside and outside in the thickness direction.

When the working core mold and the cavity mold are clamped together, a molded product-shaped space is formed with the protrusions on the core mold side and the protrusions on the cavity mold side overlapped.

After injecting and filling this space with resin, when the core mold and cavity mold are opened, the molded product will have a recess corresponding to the convex shape on the cavity side on its outer or inner surface, and a recess corresponding to the shape of the convex part on the cavity side, and A recess corresponding to the shape of the protrusion on the core side is formed on the outer surface.

A portion where the convex portion on the core side and the convex portion on the cavity side overlap is formed as a horizontal hole passing through from side to side.

Example Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of the configuration of a mold for resin molding according to the present invention, and FIG. 2 shows a molded product formed by the mold.

The mold is composed of an upper mold 10 and a lower mold 11. A core 100 is formed in the upper mold 10.

In addition, the lower mold 11 has a cavity 1 corresponding to the core 100.
10 are formed.

A tongue-shaped convex portion 12 extending downward is formed on the side wall of the core 100 of the upper mold 10 .

On the other hand, inside the cavity portion 110 of the lower mold 11, a tongue-shaped convex portion 13 corresponding to the convex portion 12 on the core side is formed to extend upward.

Convex portion 12 on the core 100 side and convex portion 1 on the cavity 110 side
The tip portions of No. 3 are formed to match the shapes of one side and the other side that divide the horizontal hole shape to be machined into upper and lower parts. When the upper mold 10 and the lower mold 11 are clamped, the protrusions 12 on the core 100 side and the protrusions 13 on the cavity 110 side are overlapped so that the dividing lines L that divide the horizontal holes coincide with each other.

The convex portion 12 on the core side and the convex portion 13 on the cavity 110 side are manufactured with high precision as separate pieces from the upper and lower molds, and are assembled integrally into the respective molds.

Of course, it is also possible to process it in one piece with high accuracy from the beginning using an NC machine or the like.

When molding the molded product 20, when the upper mold 10 and the lower mold 11 are clamped, the respective protrusions 12.13 overlap inside and outside in the thickness direction, and recesses 22.13 corresponding to the shapes of the respective protrusions are formed inside and outside. 23 is formed.

A horizontal hole shape is formed in the overlapping portion of the convex portions 12,13. This side hole can be formed into various shapes such as an irregular shape such as a keyhole shape, or a circular shape.

Horizontal hole 2 formed by overlapping protrusions 12 and 13
4, convex portions 12 and 1 for the inner and outer overlap thickness.
It is preferable that the respective wall thicknesses formed by the tip portions 3 are approximately equal. However, as long as a hole with good precision can be formed without distortion due to molding conditions, etc., there is no problem even if the hole is non-uniform.

Next, the resin molding method according to the present invention will be explained using mainly FIGS. 3(a) to 3(d).

First, as shown in FIG. 3(a), a horizontal hole having a rectangular upper part and a circular lower part connected thereto, that is, an inverted keyhole-shaped horizontal hole is formed using the upper mold 10 and the lower mold 11. In this case, the tip of the protrusion 12 on the core side has a semicircular shape, and the tip of the protrusion 12 on the cavity side has a semicircular rectangular mold opening structure. In this case, the portion where the protrusion 12 on the core side and the protrusion 13 on the cavity side overlap has an inverted keyhole shape with an upper rectangular shape and a lower circular shape.

For molding a molded product, the upper mold 1 manufactured as described above
0 and the lower mold 11 are clamped, the convex portion 12 on the core side and the convex portion 13 on the cavity side form concave portions corresponding to the convex shape on the inside and outside in the thickness direction, and their tips overlap with each other.

Next, the space formed by the core part 100 and the cavity part 110 is injected and filled with molten resin.

After that, after the resin is cooled and hardened in the cooling process, the upper mold 1
0 and the lower mold 11 are opened in the vertical direction.

Through the above molding process, a molded product 20 is formed as shown in FIG. A recess 22 corresponding to the shape of the protrusion 12 on the cavity side is formed on the outside of the side wall 21 of the molded product 20 . Then, inside the side wall 21, a protrusion 13 on the core side is provided.
A recess 23 corresponding to the shape is formed. Then, a horizontal hole 24 penetrating inside and outside of the side wall 21 is formed in the shape of an inverted keyhole at a portion where the protrusion 12 on the core side and the protrusion 13 on the cavity side overlap.

In the case of the method of the present invention, the shape of the horizontal hole 24 is as shown in FIG.
It is not limited to the shape shown in FIG. 3, but various shapes such as those shown in FIGS. 3(b) to 3(d), for example, can be formed.

FIG. 3(b) shows an example of forming the horizontal hole 24 in a perfect circular shape. In this case, the tips of the protrusion 12 on the core side and the protrusion 13 on the cavity side may be formed into a semicircular shape that is symmetrical to each other with respect to the dividing line L of the horizontal hole 24 by overlapping butts.

FIG. 3(c) shows an example of forming a horizontal keyhole-shaped horizontal hole. In this case, the protrusion 12 on the core side
One side of the tip is rectangular and the other side of the key hole is formed into a semicircular shape. It is sufficient if they are formed into a symmetrical half-split shape and made coincident with the dividing line L.

FIG. 3(d) shows an example of molding a rectangular horizontal hole 24 in which one diagonal line is inclined at a predetermined angle with respect to the inner surfaces of the upper and lower molds. In this case, the dividing line L of the horizontal hole 24 coincides with the inclined diagonal line. Then, the tip of the protrusion 12 on the core side is formed into a shape matching the triangular shape of one side divided by the horizontal diagonal, and the tip of the corresponding protrusion 13 on the cavity side is formed on the other side. What is necessary is to form them into a triangular shape, overlap them, and butt them at diagonal positions.

As mentioned above, the maximum width in the left and right direction of the horizontal hole is the dividing line L.
A lateral hole of any shape can be formed by the method described above, as long as the convex shape is parallel to or smaller on the proximal side with respect to the dividing line.

In the embodiment, the mold is clamped and opened vertically, but the method can be applied in the same manner as described above even if the mold is clamped and opened horizontally.

As described in detail, according to the present invention, horizontal holes of various shapes perpendicular to the mold clamping direction can be easily formed only by the mold clamping and mold opening operations between the core and the cavity.

Therefore, the mold structure can be simplified and manufactured at low cost.

Furthermore, since the molding operation can be completed by only mold clamping and mold opening operations in one direction, the molding process can be simplified, the operation control of the mold can be simplified, and the process time required for molding can be shortened.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a configuration example of a resin molding die to which the present invention is applied, Fig. 2 is a perspective view showing a molded product formed by the mold, and Figs. 3 (a) to (d) are An explanatory diagram illustrating a method of forming a horizontal hole and its shape, FIG. 4 is a perspective view showing the shape of a conventional molded product, and FIG. 5 is a perspective view showing a mold configuration for molding the molded product shown in FIG. 4. It is. DESCRIPTION OF SYMBOLS 10... Upper mold, 100... Core part, 11... Lower mold, 110... Cavity part, 12... Convex part on the core side, 130φ・Convex part on the cavity side, 20... Molded product, 2411 φ horizontal hole. 0 Applicant NEC Home Electronics Figure 1 Figure 2 Figure 3 (a) (b)shi\)
(D) 110 13 11Q

Claims (6)

[Claims] (1) Forming a convex portion having a shape on one side that forms a hole shape on the side wall of the core mold, and forming a convex portion having a shape on the other side forming the hole shape on the side wall of the cavity mold; A horizontal hole forming method in resin molding, characterized in that the two convex portions are overlapped by mold clamping with a cavity mold and a horizontal hole perpendicular to the mold clamping direction is formed in the overlapping portion of the two convex portions. (2) The two convex portions are overlapped on the inside and outside in the wall thickness direction, and the two convex portions overlap to form a hole shape in one side and the other side in the mold clamping direction with substantially equal wall thickness. A horizontal hole forming method in resin molding according to claim (1). (3) The two convex portions are formed as separate pieces or integrated, and are integrally attached to the corresponding portions of the core mold and cavity mold, respectively, and overlap inside and outside in the wall thickness direction perpendicular to the mold clamping direction. A horizontal hole forming method in resin molding according to claim (1) or (2). (4) The resin molding according to claim (1) or (2), wherein the two convex portions overlap to form an irregular shape such as a keyhole shape, a perfect circle or an ellipse shape, a square hole shape, etc. Side hole forming method. (5) A recess according to claim (1) or (2), characterized in that a recess corresponding to the shape of the two convex parts is formed inside and outside in the thickness direction, and a horizontal hole is formed at the overlapping part of the two convex parts. Side hole forming method in resin molding. (6) The horizontal hole forming method in resin molding according to claim (1) or (2), wherein the inner and outer thicknesses of the overlapping portions of the two convex portions in the wall thickness direction are made substantially equal.