JPS625301Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a mold for molding a molded product having an undercut portion, such as the handle of a plastic container.

2. Description of the Related Art Molding molds having a split mold are known, in which a split mold is provided between a fixed mold and a movable mold, and the split mold is slid outward by an angular pin when the mold is opened. Further, a slide piece is provided on the split mold, and this is slid as the split mold moves,
There is also known a molding die that can be disengaged from an undercut portion of a molded product. However, since the slide piece is in close contact with the outer surface of the molded product and the undercut, even if the split mold moves when the mold is opened, the slide piece may not slide smoothly. There is a risk of damaging the handle part of the molded product due to engagement with the part.

This invention was made with attention to the above circumstances, and its purpose is to smoothly and reliably slide a slide piece that has an engaging part that engages with the undercut part of a molded product, and when the mold is opened. The object is to provide a molding die that does not damage the molded product.

This invention will be explained below based on an embodiment shown in the drawings. In the figure, 1 is a fixed mold, 2 is a stripper plate, and 3 is a movable mold. The fixed mold 1 is provided with a recess 4, and the fixed mold 1 is provided in the recess 4.
A split mold 6 is provided which is movable outward by an angular pin 5 protruding from. Then, the fixed mold 1, the stripper plate 2 and the split mold 6
A cavity 7 is formed by. Also,
The movable mold 3 is provided with a core 8 to be inserted into a cavity 7, and is capable of molding a molded product 9 such as a container having an undercut portion 9a serving as a handle portion.

Further, the split mold 6 has a cutout on the inner side facing the cavity 7, and the cutout 6a has an inclined surface 10, a first step 11, and a second step 1.
2 are provided consecutively. In addition, a first slide piece 13 and a second slide piece 13 are provided in the notch 6a of the split mold 6.
The slide pieces 14 are provided in a vertically overlapping manner. The first slide piece 13 is provided at its upper part with an inclined sliding surface 15 that joins with the inclined surface 10, and at its lower part is provided with an engaging part 16 which engages with the undercut part 9a. .
Furthermore, the front surface of the first slide piece 13 is joined to the outer surface of the molded product 9, and the rear surface is joined to the first stepped portion 11. Further, the upper surface of the second slide piece 14 is joined to the lower surface of the first slide piece 13, and the lower surface is joined to the stripper plate 2. Furthermore, a locking protrusion 17 interposed between the second step portion 12 and the rear surface of the first slide piece 13 is integrally provided at the rear end of the second slide piece 14 . Further, the joint portion of the first and second slide pieces 13 and 14 has a recess 1 facing each other.
8 and 19 are provided, and a first compression spring 20 is interposed between these recesses 18 and 19. Further, recesses 21 and 22 facing each other are provided at the joint between the split mold 6 and the second slide piece 14, and a second compression spring 23 is interposed between these recesses 21 and 22. . Furthermore, a guide pin 24 is provided protrudingly on the first slide piece 13, and this guide pin 24 passes through the second slide piece 14 and is inserted into an engagement hole 25 drilled in the stripper plate 2. It matches. The engagement length a of the guide pin 24 with respect to the engagement hole 25 is set to be slightly larger than the engagement length b of the undercut portion 9a with respect to the engagement portion 16.

Therefore, when the split mold 6 slides outward along the angular pin 5, that is, in the direction of arrow A, due to the restoring force of the second compression spring 23 when the mold is opened, the first
Since the slide piece 13 is urged upward by the first compression spring 20, the inclined sliding surface 15 slides upward, that is, in the direction of arrow B while sliding on the inclined surface 10. At this time, since the guide pin 24 is inserted into and engaged with the engagement hole 25, the first slide piece 13 is guided in the vertical direction and does not move outward with the split die 6. As the first slide piece 13 continues to slide upward, the engagement portion 16 and the undercut portion 9a are disengaged, and then the guide pin 24 is pulled out from the engagement hole 25. Therefore, the first and second slide pieces 1
3 and 14 are movable relative to the stripper plate 2, and as the split mold 6 moves, they move in the direction of arrow A.
The front surface of the first slide piece 13 is separated from the molded product 9.

In this way, the first slide piece 13 slides in the direction of arrow B and then in the direction of arrow A until the engaging part 16 comes off from the undercut part 9a of the molded product 9. The engaging part 16 does not get caught on the undercut part 9a and damages the molded product 9, and the first slide piece 13 is pushed up by the restoring force of the first compression spring 20, so it can be smoothly moved. can be slid to.

As explained above, this invention includes first and second slide pieces provided in a split mold that slides outward by an angular pin, and an engagement mechanism that engages the first slide piece with the undercut portion of the molded product. In addition, the first slide piece is slid in a direction perpendicular to the moving direction of the split mold by means of a guide pin until this engaging part is disengaged from the undercut part. This can be done smoothly and reliably, and it is possible to prevent the molded product from getting caught in the undercut part. Therefore,
This has the effect that the mold opening operation can be easily performed without damaging the molded product when opening the mold.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a cross-sectional view of the main part showing the mold clamping state, and FIG. 2 is a cross-sectional view of the main part showing the mold opening state. 1...Fixed mold, 3...Movable mold, 5...Anguilla pin, 6...Split mold, 7...Cavity, 9
...Molded product, 9a...Undercut part, 13...
...first slide piece, 14...second slide piece, 16...engaging portion, 20...first compression spring, 23...second compression spring, 24...guide pin.

Claims (1)

[Scope of utility model registration request] In a molding die for forming a molded product having an undercut portion, a cavity is formed by a fixed mold, a movable mold, and a split mold, and the undercut portion is provided at an angle and protrudes from the fixed mold and splits when the mold is opened. An angular pin that slides the mold outward, an inclined surface provided inside the split mold, and an inclined sliding surface provided inside the split mold and joined to the slope surface, and perpendicular to the moving direction of the split mold. a first slide piece that is slidable in the same direction as the split mold and that has an engaging portion on the inner surface that engages with the undercut portion of the molded product; a second slide piece; a first compression spring that is interposed between the first and second slide pieces and biases the first slide piece in a direction in which the engaging portion thereof is separated from the undercut portion; A second compression spring is interposed between the second slide piece and the split die and biases them in a direction away from each other, and the engagement portion and the undercut portion protrude from the first slide piece. A molding die comprising: a guide pin that prevents the first slide piece from sliding outward until the first slide piece is removed.