JPS641058Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an ejection mechanism of a double molding die used in a double injection molding method.

The double injection molding method is a method in which a primary molded product is molded in a primary molding cavity, and a molding material is further injected around the primary molded product in a secondary molding cavity to produce a double molded product. When double molding is performed using a double molding mold, the primary molded product molded in the primary molding cavity is pulled out from the primary molding cavity while attached to the core when the mold is opened, and is removed from the movable side metal mold. By rotating the mold, it is moved to the secondary molding cavity side. Thereafter, the mold is closed and the primary molded product is stored in the secondary molding cavity, and then material is injected into the secondary molding cavity to complete the double molded product. Next, the mold is opened again and the double molded product is pulled out of the secondary molding cavity while attached to the core, and then the double molded product is pushed out of the core by the ejection mechanism. , the double molded product is removed from the mold.

By the way, the ejecting mechanism of an injection mold is provided in the movable mold together with the core to which the molded product is attached, but the ejecting mechanism of a double molding mold is able to prevent the primary molded product from being pushed down It must be able to push down only heavy molded products.

For this reason, the ejection mechanism of conventional double molding molds is
It is divided into two parts, and only the ejection mechanism on the core side to which the double molded product is attached always operates, resulting in a complicated structure of the ejection mechanism and the disadvantage that it takes time and effort to manufacture the mold. This caused problems such as frequent mold failures.

This idea was made in view of the above circumstances,
By providing a simple ejection mechanism that only pushes down the double molded product without pushing down the primary molded product,
The purpose is to reduce the labor involved in manufacturing double molding molds and to reduce mold failures.

This invention will be described in detail below with reference to the drawings.

FIG. 1 shows a three-piece mold for double molding equipped with an embodiment of the protruding mechanism of this invention, and reference numeral 1 in the figure indicates the mold. This mold 1 is for molding a thick hollow cylindrical body, and is divided into a fixed mold 1a and a movable mold 1b with a dividing surface 2 as a boundary. An inventive protrusion mechanism 3 is provided.

The fixed-side mold 1a is made up of a fixed-side mounting plate 4, a runner stripper plate 5, and a fixed-side mold plate 6 stacked one on top of the other. 7a (abbreviated as cavity) 7a, and cavity for secondary molding (hereinafter referred to as
A secondary cavity (abbreviated as secondary cavity) 7b is formed. In this mold 1, the inner peripheral part of the hollow cylindrical body is primarily formed in a primary cavity 7a, and a secondary cavity 7b is formed.
The outer periphery of the hollow cylindrical body is secondarily molded to produce a double molded product. Therefore, the primary cavity 7a
The diameter of the opening surface on the dividing surface 2 side is the diameter of the secondary cavity 7
The diameter is smaller than the diameter of the opening surface on the dividing surface 2 side of b.

The movable mold 1b is made up of a lower plate 8a and an upper plate 8b of the movable mounting plate 8, spacer blocks 9, 9, a receiving plate 10, and a movable mold plate 11 stacked one on top of the other. Lower plate 8a of movable side mounting plate 8
A cylindrical core 12, 12 is provided between the upper plate 8b and the upper plate 8b.
One end is clamped and fixed. The other end of this core 12 is provided with an inner diameter pin 13 for forming a hollow part of the double molded product.
3 protrudes from the movable mold plate 11.

The ejector mechanism 3 provided on the movable mold 1b has a lower ejector plate 14a and an upper ejector plate 14b pushed out by the ejector of the molding machine.
A plurality of protruding members 15, 15 are provided for pushing down the molded product. Ejector plate top and bottom 1
4b and 14a are stacked on top of each other and are provided in a space between the movable side mounting plate 8 and the receiving plate 10 formed by the spacer blocks 9, 9 so as to be movable in the direction of the arrow in the figure. As the protruding member 15, a hollow cylindrical sleeve pin is used. The diameter of the hollow portion 15a of this protruding member 15 is larger than the diameter of the opening surface on the dividing surface 2 side of the primary cavity 7a, and smaller than the diameter of the opening surface on the dividing surface 2 side of the secondary cavity 7b. . This protruding member 1
5 is slidably fitted into the core 12, and one end is connected to the upper and lower ejector plates 14.
b, 14a, and the other end surface is flush with the surface of the movable mold plate 11 on the dividing surface 2 side.

Next, the operation of the mold 1 when molding a double molded product will be explained.

First, the primary cavity 7a of the closed mold 1
Material is injected into the tube, and the inner circumference of the hollow cylinder is formed as a primary molded product. Thereafter, the mold 1 is opened and the primary molded product attached to the core 12 is extracted from the primary cavity 7a. Subsequently, the protruding mechanism 3 operates and the protruding member 15 is protruded. However, the outer diameter of the primary molded product is
Since the diameter of the primary molded product is smaller than the diameter of the hollow part 1
5a, and will not be pushed down while remaining attached to the core 12. After that, move the movable mold 1b around the center axis perpendicular to the dividing surface 2.
Core 12 rotated 180 degrees and attached with primary molded product
is moved to the secondary cavity 7b side.

Next, the mold is closed and the primary molded product is stored in the secondary cavity 7b, after which a molding material is injected into the secondary cavity 7b, and the outer peripheral part is molded on the outside of the primary molded product, resulting in a double molded product. It is formed. Subsequently, the mold is opened again and the double molded product is pulled out from the secondary cavity 7b while attached to the core 12. After this, the protruding mechanism 3 operates and the protruding member 15 is protruded. Since the outer diameter of this double-molded product is larger than the diameter of the hollow part 15a of the protruding member 15, the double-molded product does not fit into the hollow part 15a of the protruding member 15 and is pushed down and removed from the mold 1. It will be done. During this time, the primary molded product is being molded as described above on the other core 12 side, and the same operation is repeated thereafter to continuously produce double molded products.

In the case of such a protrusion mechanism 3 of a double molding mold, a hollow part 15a is provided in the protrusion member 15, and the diameter of this hollow part 15a is set to be larger than the diameter of the primary cavity 7a on the dividing surface 2 side. Since the dimension is smaller than the diameter of the cavity 7b on the side of the dividing surface 2, when the protruding member is pushed out, the primary molded product will fit in the hollow part 15a and will not be pushed down, and the double molded product will not fall into the hollow part 1.
It doesn't fit in 5a, so it gets pushed down. Therefore, this protrusion mechanism 3 can always push down only the double molded product even if the protrusion member 15 on the primary cavity 7a side and the protrusion member 15 on the secondary cavity 7b side are operated in the same manner.

What is shown in FIG. 2 shows a second embodiment of this invention, and the same components as those in the embodiment shown in FIG.

In the mold 1 of this example, the protruding member 15 is a single plate, and the protruding member 15 is provided on the stationary mold plate 6 so as to be superimposed thereon. Hollow portions 15a, 15a are bored in the protrusion member 15 at positions corresponding to the cores 12, 12, and are slidably fitted into the cores 12, 12. Further, this protruding member 15 is connected to the upper and lower ejector plates 14b and 14a via pins 16, so that it moves in the direction of the arrow in the figure.

Even with the protrusion mechanism 3 of this example, the same effects as the protrusion mechanism 3 shown in FIG. 1 can be obtained.

In the above explanation, the movable mold 1b is rotated to move the primary molded product from the primary cavity 7a side to the secondary cavity 7b side, but the cavity replacement operation is performed as shown in FIG. Alternatively, a method may be used in which the stationary mold 1a is rotated about the central axis perpendicular to the dividing surface 2 as the rotation axis. Also,
As shown in FIG. 4, the fixed side mold 17 is formed by laying two regular fixed side molds 1a side by side, with a primary cavity 7a on one side and a secondary cavity 7b on the other side. If provided, the cavity can be replaced by reciprocating the stationary mold 17 by a predetermined distance as shown by the arrow in the figure.

As explained above, the protrusion mechanism of the double molding mold of this invention has an opening larger than the opening on the dividing side of the primary molding cavity and smaller than the opening on the dividing side of the secondary molding cavity. A protruding member with a hollow part is provided by fitting the hollow part into the core so that the double molded product can be pushed down, so it can be used as a protruding member on the primary molding cavity side. Even if the projecting member on the side of the cavity for secondary molding is pushed out at the same time, only the double molded product can be pushed down without pushing down the primary molded product. For this reason, it is no longer necessary to operate the protruding members on the primary molded product side and the double molded product side separately, and the ejecting mechanism of this invention has a simple structure, which saves time and effort in mold manufacturing. It is possible to reduce mold failures.

[Brief explanation of the drawing]

Figures 1 and 2 are partially sectional plan views showing a mold equipped with an embodiment of the ejection mechanism of this invention, and Figures 3 and 4 are diagrams for explaining the cavity replacement operation, respectively. Explanatory diagram. 1...Mold, 2...Dividing surface, 3...Protrusion mechanism,
7a... Cavity for primary molding (primary cavity), 7b... Cavity for secondary molding (secondary cavity), 12... Core, 13... Inner diameter pin, 1
5... Projection member, 15a... Hollow part.

Claims (1)

[Claims for Utility Model Registration] A cavity for primary molding that forms part of a surface of a primary molded product, a cavity for secondary molding that forms a part of a surface of a double molded product, a primary molded product and a double molded product When the mold is opened, the primary molded product formed in the primary molding cavity is pulled out from the primary molding cavity while attached to the core, and the movable side mold is A protruding mechanism provided on a double molding mold that moves toward the secondary molding cavity side as it rotates, which is larger than the opening surface on the dividing surface side of the primary molding cavity, and is larger than the opening surface of the secondary molding cavity. A protrusion member is provided with a hollow portion that opens smaller than the opening surface on the dividing surface side, and the hollow portion is slidably fitted into the core, thereby pushing down the double molded product. Ejection mechanism of double molding mold.