JPS5814298B2 - mold for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold apparatus for plastic molding, and more particularly to a mold apparatus for removing undercuts.

Conventionally, a movable member 4 is attached to the side of a movable mold 3 during molding of a molded product 1 having undercuts 2a, 2b, etc. on the outside of the molded product 1, such as a bottle container as shown in FIG. When opening, the molded product 1 first moves back with respect to the movable die 4, and the others move backwards with respect to the movable mold 3 (moves downward in the figure), and in the middle of the backward stroke, the mover 4 opens in the direction of arrow A, resulting in the undercut portion 2a + 2b. ...is to be removed.

However, recently, it has become desirable to give the handle part (hereinafter referred to as the R part) a rounded shape (hereinafter referred to as the R part) as shown in Figure 2, as it is desired to make the handle part (part A in Figure 1) of objects to be transported such as containers feel more comfortable. It has come.

Such an undercut with an R portion cannot be removed simply by pulling out the slide core in the A direction.

The object of the present invention is to provide a mold device for removing the R portion of the above-mentioned undercut.

Next, one embodiment of the present invention will be described with reference to FIGS. 3 and 4. Reference numeral 11 denotes a fixed mold attached to a fixed mold mounting plate (not shown).

Reference numeral 12 denotes a movable mold mounting plate to which a movable mold 13 that moves forward and backward with respect to the fixed mold is attached.

Reference numeral 14 denotes a slide core that moves in the direction of arrow B when the mold is opened, and removes the rib 16 and handle 17, which are the undercut portions of the molded product 15.

A rotating block 18 is rotatably attached to one end of the coupling shaft 19 with a pin 20, and is loosely fitted inside the slide core 14 and forms a cavity in the R portion of the undercut portion. , the undercut of the molded product is removed by rotation.

The coupling shaft 19 is slidably inserted from the outside of the slide core substantially parallel to the moving direction of the slide core, and the other end 19a is always pressed by a spring 22 against a cam 21 attached to the fixed mold 11. ing.

Therefore, as the mold opening progresses and the movable mold 13 retreats, the other end 19a comes into contact with the slope 21a of the cam 21, and the other end 19a moves along the slope 21a. As shown in the figure, while the slide core 14 is retreated in the axial direction by the dimension l, the slide core 14 is also retreated in the direction of the arrow B by a driving source (not shown) from the cavity forming position by the dimension S, which is larger than the dimension l. block 18
is rotated in the direction of arrow C using the pin 20 as a fulcrum to remove the undercut portion marked with an radius.

After the undercut part is completely removed, the rotation block 18 is pulled by the spring 22, rotates in the direction of arrow D using the pin 20 as a fulcrum, and is pulled back into the slanted hole 23 in which it has been housed. , in preparation for cavity formation during mold clamping.

With the structure described above, the drawbacks listed at the beginning can be removed and the undercut portion with the radius can be removed.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a conventional device. FIG. 2 is an explanatory diagram of part A in FIG. 1. FIG. 3 is a view showing one embodiment of the present invention in a mold clamped state. FIG. 4 is a view after opening the mold in FIG. 3. 11... Fixed mold, 13... Moving mold, 14... Slide core, 15... Molded product, 18... Rotating block, 19
...Connection shaft, 21...Cam, 22...Spring.

Claims (1)

[Scope of Claims] 1. A plastic molding die having a slide core for removing an undercut, comprising the following constituent elements. a. a movable mold that moves forward and backward relative to the fixed mold and cooperates with the fixed mold to form a cavity; b. From the side of the fixed mold and the movable mold together with both molds. C. a slide core that cooperates to form a cavity, moves back together with the movable mold to a predetermined position when the mold is opened, and then moves in a direction in which the cavity is released and the undercut is removed; One end is slidably inserted from the outside of the slide core parallel to the moving direction of the slide core, and the other end is located outside the slide core and is attached to a cam, etc. provided on a fixed part of a fixed mold, etc. with a spring. a bond axis that is constantly pressed through the d. It is attached to one end of the shaft so as to be rotatable about a pin as a fulcrum, and is loosely fitted inside the slide core, and when the mold is clamped, it is integrated with the slide core to form the cavity of the R part of the undercut, and the mold is opened. When the slide core is moved to remove the undercut, the shaft is pulled back together with the slide core to a predetermined position, and then the shaft is pulled through the spring due to the continued retreat of the slide core. Undercut} Rotating block that rotates to remove the R section.