JPH11277589A - Mold for injection molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To demold a molded product surely in an ejection process after mold opening in a mold for injection molding which molds a complex shape. SOLUTION: A movable side cavity block 16 for forming at least part of the side surface of a molded product 10 is provided, a spring plunger 17 which acts vertically to the opening/closing direction of a mold is fitted to the cavity block 16, in an ejection process after mold opening, the molded product 10 is ejected in the mold clamping direction by the first ejector pin 18, and simultaneously the cavity block 16 is ejected in the same direction by the second ejector pin 19. In this process, the cavity block 16, while being biased by the spring plunger 17, slides on the step surface of a side plate 15, after having moved in the mold clamping direction, moves also vertically to the direction, and separates from the molded product 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for injection molding,
In particular, the present invention relates to the structure of an injection molding die when the shape of a molded product is complicated.

[0002]

2. Description of the Related Art In general, an injection molding die having a simple shape of a molded product has a structure in which an ejector pin contacts a bottom portion of the molded product and protrudes the molded product to discharge the molded product. Since the shape of the molded product is complicated, for example, as shown in FIG. 8 (a perspective view showing an example of the molded product), there is a protruding portion 10a on the side surface, and a small hole 10b in the opening and closing direction of the mold. In the case of the injection molding die in which the contact area of the ejector pin cannot be sufficiently obtained, at least a part of the side surface corresponding to the opening and closing direction of the die is formed by a cavity block attached to the movable side mold plate, In order to stably project the molded product, an ejector pin that is in contact with the protrusion on the side surface is provided in addition to the ejector pin that is in contact with the bottom of the molded product.

[0003] Such an example will be described with reference to the drawings. 9A, 9B, and 9C are cross-sectional views showing a conventional example. In the figure, 10 is a molded product, 24 is a core, 2
6 is a movable side cavity block, 28 is a first ejector pin, and 29 is a second ejector pin. The first ejector pins 28 and the second ejector pins 29 are fixed to the same ejector plate (not shown).

FIG. 9 (a) shows a mold opened state after injection molding. FIG. 9B shows the ejected state after the mold is opened, in which the first ejector pin 28 and the second ejector pin 29 protrude the molded product 10. FIG.
(C) shows an eject end state, in which the first ejector pin 28 and the second ejector pin 29 return to their original positions, and the molded article 10 is discharged.

[0005]

However, in such an injection molding die, since the ejector pin sandwiches the molded product in the ejected state, the molded product is completely released even after the ejection is completed. There was a problem that sometimes did not.

The present invention solves such a problem and provides an injection molding die capable of stably ejecting a molded article having a complicated shape and reliably releasing the molded product in an ejecting step after opening the mold. The purpose is to provide.

[0007]

In order to achieve this object, in the present invention, a fixed-side cavity block fixed to a fixed-side mold plate and a side surface fixed to a movable-side mold plate and coinciding with a mold opening / closing direction are provided. A side plate fixed to the movable mold plate and having a stepped surface beside the side surface of the core; and a movably disposed between the side surface of the core and the stepped surface of the side plate. A movable cavity block which is provided and forms at least a part of a side surface of a molded article; and a spring mounted on the movable side cavity block and in contact with a side surface of the core to press the movable side cavity block against a stepped surface of the side plate. A movable body cavity block having a plunger, a first ejector pin for projecting a molded product, and a second ejector pin for projecting the movable side cavity block; Is the injection mold also moves in a direction away when protruded to the ejector pin of the second with the mold clamping direction while sliding the stepped surfaces of the side plates from the side of the core.

That is, the movable-side cavity block forming at least a part of the side surface of the molded product also functions as an ejector. In the ejecting step, the movable cavity block moves in the mold clamping direction while being in contact with the side surface of the molded product, and then moves in the vertical direction. The molded product is separated from the molded product, so that the molded product is stably ejected and the mold is reliably released.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional view schematically showing an injection mold according to the present invention. In the figure,
1 is a fixed-side mounting plate, 2 is a fixed-side template, 3 is a movable-side template,
4 is a spacer block, 5 is a movable side mounting plate, 6 is a guide bar, 7 is an ejector plate, 8 is an ejector guide pin, and 9 is a return pin. These are components usually provided in an injection mold. is there. E denotes an ejector rod of the molding machine, which moves the ejector plate 7 to a fixed side when discharging a molded product.

Reference numeral 10 denotes a molded product, for example, as shown in FIG.
As shown in (a perspective view showing an example of a molded product), both side surfaces coincide with the opening / closing direction of the mold, and have a projection 10a.
In this example, a plurality of small holes 10b
Have a high density.

A fixed-side cavity block 11 is fixed to the fixed-side mold plate 2.
1 is provided with a return pin 12 urged in the movable side by a spring. A core 14 is fixed to the movable mold plate 3 via a back plate 13, and a movable cavity block 16 is movably disposed between the core 14 and the side plate 15 on both sides. A first ejector pin 18 and a second ejector pin 19 are fixed to the ejector plate 7.

The core 14 is provided with a core pin 14a at the tip, and forms a small hole with the bottom of the molded product 10. The tip of the first ejector pin 18 penetrates the core 14 and contacts the bottom of the molded product 10 to protrude toward the fixed side. The second ejector pin 19 is provided on the movable side cavity block 1.
6 and protrude toward the fixed side.

The movable side cavity block 16 forms a side surface of the molded product 10 with a part of the side surface on the core 14 side. FIG. 2 shows a perspective view thereof. A spring plunger 17 is attached to the movable-side cavity block 16, the tip of which contacts the core 14 and biases the movable-side cavity block 16 toward the side plate 15.

As shown in a perspective view of FIG. 3, the side plate 15 has a first plane 1 with a stepped portion 15a interposed therebetween.
5b and the second flat surface 15c, and form a stepped surface. The side plate 15 has a movable side cavity block 1 in which the distance between the first plane 15b and the side surface of the core 14 is
6 and the second
The distance between the flat surface 15c and the side surface of the core 14 is larger than the thickness of the movable side cavity block 16.

FIG. 4 is a sectional view showing a state of the mold of FIG. 1 before clamping. In this state, the movable side cavity block 16 is in contact with the first flat surface 15 b of the side plate 15, and there is a gap between the movable side cavity block 16 and the core 14. FIG. 5 is a cross-sectional view showing a closed state of the mold of FIG. The movable side cavity block 16 abuts on the return pin 12 in the process of mold clamping, changes its relative position with respect to the side plate 15 and comes into contact with the second plane 15c, and as a result, is perpendicular to the mold opening / closing direction. And the opposite side surface is brought into close contact with the side surface of the core 14. In this state, injection molding is performed.

FIG. 6 is a cross-sectional view showing the mold opening state of the mold of FIG. The relative position of each part on the movable side is the same as before. FIG. 7 is a sectional view showing an ejected state of the mold of FIG.
The ejector rod E in FIG. 1 pushes out the ejector plate 7, and as a result, the first ejector pin 18 projects the molded product 10, and the second ejector pin 19 projects the movable side cavity block 16. The cavity block 16 changes its relative position with respect to the side plate 15 and comes into contact with the first plane 15b again. As a result, the cavity block 16 moves perpendicularly to the mold opening / closing direction, separates from the side surface of the core 14, and forms. Article 10
Is released. The molded product is taken out and ejector rod E
Returns to the state of FIG.

[0017]

As described above, according to the present invention,
It is possible to provide an injection molding die capable of stably ejecting a molded article having a complicated shape in an ejecting step after opening the mold and releasing the molded article reliably.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view schematically showing an injection mold according to the present invention.

FIG. 2 is a perspective view showing a movable-side cavity block of the mold of FIG. 1;

FIG. 3 is a perspective view showing a side plate of the mold of FIG. 1;

FIG. 4 is a cross-sectional view showing a state of the mold of FIG. 1 before clamping.

FIG. 5 is a cross-sectional view showing a closed state of the mold of FIG. 1;

FIG. 6 is a cross-sectional view showing a mold opening state of the mold of FIG. 1;

FIG. 7 is a sectional view showing an ejected state of the mold of FIG. 1;

FIG. 8 is a perspective view showing an example of a molded product.

FIG. 9 is a sectional view showing a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fixed-side mounting plate 2 fixed-side template 3 movable-side plate 4 spacer block 5 movable-side mounting plate 6 guide bar 7 ejector plate 8 ejector guide pin 9 return pin 10 molded product 11 fixed-side cavity block 12 return pin 13 back plate 14, 24 Core 15 Side plate 16, 26 Movable cavity block 17 Spring plunger 18, 28 First ejector pin 19, 29 Second ejector pin

Claims (1)

[Claims] 1. A fixed-side cavity block fixed to a fixed-side mold plate, a core fixed to a movable-side mold plate and having a side surface coinciding with a mold opening / closing direction, and a core fixed to the movable-side mold plate and fixed to the movable-side mold plate. A side plate having a step surface on the side of the side surface, and a movable side cavity movably disposed between the side surface of the core and the step surface of the side plate to form at least a part of the side surface of the molded article. A block, a spring plunger mounted on the movable-side cavity block and in contact with a side surface of the core to press the movable-side cavity block against a stepped surface of the side plate; a first ejector pin for projecting a molded product; A second ejector pin for projecting the cavity block, wherein the movable side cavity block is provided with the side ejector when projected to the second ejector pin. A mold for injection molding, wherein the mold moves in a direction away from a side surface of the core together with a mold clamping direction while sliding on a stepped surface of the core.