JP3342088B2 - Molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus using a molding die, and more particularly to a molding apparatus suitable for in-mold molding at a relatively low pressure.

[0002]

2. Description of the Related Art A conventional molding apparatus is disclosed, for example, in Japanese Utility Model Laid-Open Publication No. 63-192015, and this example will be described with reference to the drawings. 4 is a side sectional view of the same device.

[0003] In FIGS. 3 and 4, a molding device includes a fixed die 1, a movable die 2, two pistons 103, and a hydraulic device 1.
04. The cavity 1a formed by the fixed mold 1 and the movable mold 2 is for molding interior parts for automobiles whose side section is shown in FIG. 4, and the fixed mold 1 is a mold protruding in a rectangular shape. Cylinder hole 111 at the center of both sides of the surface
Are formed to penetrate. The fixed mold 1 has these 2
A runner hole 112 is formed on the side of the individual cylinder hole 111 close to the mold surface, and a sprue hole 113 is provided to connect the center of the runner hole 112 to the opposite side of the mold surface.
A resistance heating element (not shown) is buried in the portion of the fixed die 1 around the runner hole 112, and thereby the runner hole 11 is formed.
2 is a hot runner.

Further, a wall-shaped spacer 117 is fixed to the surface of the fixed mold 1 opposite to the mold surface.
, A holding plate 118 having a through hole 181 into which a nozzle portion of an injection molding machine is inserted at a central portion is fixed. 103
Is a piston, an end face 131 on the side facing the cavity 1a.
Form a part of a mold surface, and a piston rod 132 is fixed to an end surface on the opposite side of the piston 103. 10
Reference numeral 4 denotes a drive unit, a bracket 141 fixed to the back surface of the fixed mold 1, a hydraulic device 142 fixed to the bracket 141, and a cylinder (not shown) of the hydraulic device 142.
And a hydraulic unit (not shown) for supplying pressurized oil. Hydraulic device 14
The second output shaft (not shown) is fixed to the piston rod 132 and drives the piston rod 132 directly.

[0005] The molding apparatus is used by fixing a fixed mold 1 and a movable mold 2 to a fixed platen 51 and a movable platen 52 of a mold clamping device of an injection molding machine, respectively. The periphery of the runner hole 112 of the fixed die 1 fixed to the apparatus is heated by a heating unit (not shown) to form a hot runner. Then, the piston 103 moves toward the bottom of the cylinder hole 111.
Is moved, and the mold is clamped in this state to form the cavity 1a. Next, a predetermined amount of plasticized resin is injected from the injection molding machine 106, and the injected plasticized resin passes through the sprue hole 113 and the runner hole 112 to form two cylinder holes 1.
11 is introduced. Immediately after this, the drive unit 104 is driven, and the plasticized resin in the cylinder hole 111 is removed from the piston 103.
Then, the resin is pressurized and fed into the cavity 1a, and the resin is cooled and solidified in this state to be molded. Thereafter, the mold clamping device is driven in the mold opening direction, and the movable mold 2 is driven relative to the fixed mold 1 to open the mold. Further, the driving unit 104 is driven to
3 is protruded from the fixed mold 1, and the molded product is knocked out and separated from the mold surface. Then, after taking out the molded product at last, the process proceeds to the next cycle. Thus, a molded article can be formed.

[0006]

As described above, in the conventional molding apparatus, when the molten resin stored in the cylinder hole 111 is pressed and pressed by the piston 103 and fed into the cavity 1a,
Since the fixed mold 1 and the movable mold 2 are pressed by the mold clamping device of the injection molding machine and are in close contact with each other, the gap of the cavity 1a has a minimum value. Therefore, when the molten resin is pressed and pressed into the cavity 1a by pressure, the resin pressure is hardly reduced to a target low pressure, and the apparatus is suitable for in-mold molding formed by relatively low pressure such as integral skin molding. Did not. The present invention provides a molding apparatus suitable for in-mold molding performed at a relatively low pressure, and aims to solve the above-mentioned conventional problems.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a fixed mold and a movable mold which form a cavity and a mold which forms one cavity of the same mold so as to slide freely in and out of the mold, and to inject molten resin. An annular member arranged to communicate with the sprue hole for use, a stopper for regulating the opening dimension of the cavity, and a drive device for driving the annular member and the stopper to advance and retreat. This is a means for solving the problem.

[0008]

In the molding by the molding apparatus of the present invention, first, the molding die is attached to a normal injection molding apparatus, and then the annular member and the stopper provided on the fixed mold are moved to the movable mold side by the driving device. The mold is clamped until the movable mold contacts the stopper. In this state, the molten resin is introduced from the injection molding machine into the annular member through the sprue hole. When a certain amount of molten resin is introduced, the annular member and the stopper are moved to the fixed mold side by the driving device, and the mold is immediately re-clamped.
This mold clamping causes the molten resin in the cavity to expand and contract,
Evenly distributed. Thereafter, the resin is cooled and solidified and molded, and the fixed mold 1 and the movable mold 2 are opened to take out a molded product.

[0009]

1 and 2 show an embodiment of the present invention. FIG. 1 shows a state at the time when molten resin is introduced into a resin reservoir ring.
FIG. 2 shows a state in which the molten resin introduced in the sectional view is clamped again and uniformly distributed in the cavity.
The molding apparatus includes a fixed mold 1, a movable mold 2, a driving device 3, a moving plate 4 connected to the driving device 3, an annular resin reservoir ring (annular member) 5, a stopper 6, and a sprue member 7,
The movable plate 4 is connected to the resin pool ring 5 and the stopper 6 respectively. The molding apparatus having the above configuration is used by fixing the fixed die 1 to the fixed platen 51 of the mold clamping device of the injection molding machine and the movable die 2 to the movable platen 52.

In the molding step, first, the driving device 3 is driven in a state where the mold is opened by a mold clamping device (not shown) of the injection molding machine, and the moving plate 4 is moved to the movable mold 2 side. The resin pool ring 5 and the stopper 6 connected to the moving plate 4 also move to the movable mold 2 side. In this state, a mold closing operation is performed by a mold clamping device (not shown) of the injection molding machine, and the mold is closed until the movable mold 2 and the stopper 6 abut. In this state, a molten resin is introduced from a nozzle (not shown) of the injection molding machine into the resin reservoir 5a of the resin reservoir ring 5 through the sprue hole 7a (this state is shown in FIG. 1).

When a certain amount of molten resin has been introduced, the driving device 3 is driven, and the resin pool ring 5 and the stopper 6 are embedded in the fixed mold 1 via the moving plate 4. In this state, the mold closing operation (not shown) of the injection molding machine is performed again to close the mold, and the molten resin stored in the resin pool ring 5a is compressed and spread to uniformly distribute the molten resin to the cavity 1a (this state is referred to as “the state”). (Shown in FIG. 2). In the state shown in FIG. 2, the molten resin is cooled and solidified to form a molded product. Thereafter, a mold clamping device (not shown) is driven in the direction of opening the mold, and the fixed mold 1 and the movable mold 2 are opened to take out a molded product.

[0012]

As described above in detail, according to the present invention, the molten resin is introduced into the cavity while the fixed mold and the movable mold are opened by a predetermined dimension (about 10 to 25 mm), and then the molten resin is melted by the mold clamping operation. Since the resin is compressed and stretched, it has excellent effects such that the pressure of the molten resin during molding can be adjusted to a low pressure and the pressure in the cavity can be made substantially constant.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a molding apparatus according to an embodiment of the present invention during an operation process.

FIG. 2 is a sectional view of the molding apparatus according to the embodiment of the present invention at the time of completion of the operation following FIG.

FIG. 3 is a plan sectional view of a conventional molding apparatus.

FIG. 4 is a side sectional view of the molding apparatus of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed type 1a Cavity 3 Drive 4 Moving plate 5 Resin pool ring 5a Resin pool 6 Stopper 7 Sprue member 7a Sprue hole

Claims (1)

(57) [Claims] 1. A fixed mold and a movable mold that form a cavity, and are disposed so as to freely slide in and out of a mold surface that forms one of the cavities and communicate with a sprue hole for injecting molten resin. A molding device comprising: an annular member formed as described above; a stopper for regulating an opening dimension of the cavity; and a driving device for driving the annular member and the stopper to move forward and backward.