JPH07214595A - Multi-point gate die device for sandwich molding - Google Patents

Abstract

PURPOSE:To provide a multi-point gate die device which enables easy installation of a sandwich molding part and a single material molding part side by side without wasting much of a material. CONSTITUTION:A multi-point gate die device 1 is equipped with a sandwich molding gate 11. On a third runner 12 connected directly to the sandwich molding gate 11, a first hot runner nozzle 14 which injects a skin material, a skin material reservoir 13 positioned in the downstream side of the first hot runner nozzle 14, and a second hot runner nozzle 15 for core material injection which protrudes to the skin reservoir 13 are provided. A first runner which connects the first hot runner nozzle 14 to a skin material nozzle 21 for an injection device and a second rubber which connects the second hot runner nozzle 15 to a core material nozzle 22 for the injection device are hot runners.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-point gate mold device for sandwich molding.

[0002]

2. Description of the Related Art A sandwich molding method is used to effectively use a recycled material as a core material or to improve performance by combining different materials. So-called sandwich molding, in which the core material is filled in the center of the skin material,
As shown in FIG. 4, the sandwich-shaped resin flow is injected into the sprue 92 from the double nozzle 91 of the injection device 90, and passes through the cold runner 921 and the sandwich molding gate 93.
Then, the sandwich-shaped resin flow is injected into the cavity 94 and molded.

The double nozzle 91 has an inner nozzle 912 for injecting a core material inside a main nozzle 911 for injecting a sandwich-shaped resin flow into a sprue 92. Then, the core material 82 is injected from the inner nozzle 912 into the skin material 81 in the main nozzle 911 to form a sandwich-shaped resin flow having the core material 82 as a nucleus.

The runner 921 extending from the sprue 92 to the sandwich molding gate 93 is designed so that the core material 82 and the skin material 81 do not mix during movement.
Cold runner. This is because, as shown in FIG. 5, if the route from the sprue 92 to the sandwich molding gate 93 is a hot runner 95, the skin material 81 and the core material 82 are fluidized and mixed in the hot runner 95 to form a sandwich shape. This is because the layer structure of is destroyed. In FIG. 5, reference numeral 96 is a hot runner block.

On the other hand, each resin material has its own L / T.
Since there are (L: maximum filling length, T: wall thickness), if the product (molded product) is longer than the above L / T, a plurality of gates are provided to provide a multi-point gate mold device.

[0006]

However, there are the following problems in the conventional mold apparatus that performs sandwich molding with a multi-point gate in order to manufacture a long molded product. The first point is that if a multi-point gate is used, the length of the runner (cold runner) path from the nozzle 91 of the injection device to the gate 93 must be lengthened, resulting in a large amount of wasted material and so-called material yield deterioration. It is to be.

The second point is that when a sandwich molding part and a single material molding part consisting only of a skin material are to be provided in a product (molded product), the nozzle of the injection device and the runner are made of a single material. It is necessary to provide it separately for the molding part, which complicates the device. For sandwich molding, a double nozzle is used as described above, and a sandwich-shaped resin having a core material as a core is injected from an injection device into a mold. Therefore, the nozzle and runner of the injection device for injecting only the skin material are separately required.

The third point is that the length of the cold runner becomes long, so that the pressure loss in the mold becomes large,
The injection pressure to the cavity is reduced. The fourth point is that, as a result of the runner length being different for each gate, the injection pressure differs depending on the gate, resulting in imbalance of the injection pressure. Due to the above-mentioned third and fourth problems, it becomes extremely difficult to mold a large molded product in a good shape.

In view of such conventional problems, the present invention is
An object of the present invention is to provide a multi-point gate mold device that requires less waste of material, can easily have a single material molding part in addition to a sandwich molding part, and can easily accommodate larger molded products. Is.

[0010]

The present invention is a multi-point gate mold apparatus having a sandwich molding gate for forming a sandwich-shaped molding portion having a core material as a core, which is a third device directly connected to the sandwich molding gate. The runner has a first hot runner nozzle for injecting a skin material into the third runner,
A skin material reservoir located downstream of the first hot runner nozzle and a second hot runner nozzle for injecting a core material projecting toward the skin material reservoir are provided, and the first hot runner nozzle is also provided. The first runner connecting the hot runner nozzle to the skin material nozzle of the injection device and the second runner connecting the second hot runner nozzle to the core material nozzle of the injection device are both hot runners. It is in a multi-point gate mold device for sandwich molding.

The first thing to note most in the present invention
The point is that the injection apparatus is provided with a skin material nozzle and a core material nozzle, and the first hot runner nozzle for injecting the skin material and the second hot runner nozzle for injecting the core material into the third runner connected to the sandwich molding gate. Is provided, and the nozzle of the injection device and the first and second hot runner nozzles on the die side are connected by a hot runner (first and second runners).

The second and most remarkable point is that
The first hot runner nozzle is arranged on the upstream side of the third runner, the skin material reservoir is provided on the downstream side, and the second hot runner nozzle is projected on the skin material reservoir. It should be noted that the skin material reservoir portion is a third space for accumulating the skin material, facilitating the injection of the core material into the skin material, and providing a space for providing a core material nozzle (second hot runner nozzle). The space inside the runner is large.

The multi-point gate of the mold device may be a sandwich molding gate only, or a sandwich molding gate and a single material gate composed only of a skin material or a core material may be mixed. Then, for a plurality of sandwich molding gates, the third runner having the above-described configuration is directly connected to each gate.

On the other hand, when a single material gate is mixed with the sandwich molding gate, the first runner or the second runner is used.
It is preferable to connect the single material gate to the fourth runner branched from the runner. With this configuration, it is not necessary to separately provide a nozzle for the skin material or the core material on the injection device side, and the device configuration is simplified.

[0015]

In the mold apparatus of the present invention, in the third runner connected to the sandwich molding gate, the core material is injected into the skin material to form a sandwich-shaped resin flow, which is injected from the sandwich molding gate. . That is, the core material is injected into the skin material in the skin material reservoir from the second hot runner nozzle projecting in the skin material reservoir, forming a sandwich-shaped resin flow, and injecting it from the sandwich molding gate.

The third runner, which is a cold runner, is connected to the sandwich molding gate, and has a size that allows the first and second hot runner nozzles and the reservoir to be formed. Can be shortened. Therefore, the amount of wasted resin material is extremely small.
Further, in order to provide a plurality of sandwich gates, the third runner can be formed in each and the first and second runners that are hot runners can be extended.

Since the first and second runners are hot runners, the pressure loss in the hot runners is small, and the desired terminal pressure can be obtained at each gate without imbalance. Therefore, a large molded product can be easily dealt with by providing a plurality of gates, and a molded product of good quality can be obtained.

When a single material gate for injecting only a skin material or a core material is additionally provided in addition to the hot runner nozzle, the fourth runner is branched from the first runner or the second runner, and the single runner is provided ahead of it. A material gate may be provided. Therefore, it is extremely easy to install the single material gate and the sandwich molding gate together, and it is not necessary to separately provide a nozzle for the skin material or the core material in the injection device, unlike the conventional multi-point gate mold device.

As described above, according to the present invention, it is possible to reduce the waste of materials, it is easy to install a single material molding part in addition to the sandwich molding part, and it is possible to form a large molded product. It is possible to provide a multi-point gate mold device that is easy to handle.

[0020]

EXAMPLE A multi-point gate mold device for sandwich molding according to an example of the present invention will be described with reference to FIGS. In this example, as shown in FIG. 1, two sandwich molding gates 11 for injecting a sandwich resin having a core material as a core and a single material gate 10 for injecting a skin material are used.
It is a multi-point gate mold device 1 for sandwich molding having an individual piece.

As shown in FIG. 2, the third runner 12 directly connected to the sandwich molding gate 11 has a first hot runner nozzle 14 for injecting a skin material and a first hot runner nozzle 14 located slightly upstream thereof. 2 is provided with a skin material reservoir 13 located downstream thereof and a second hot runner nozzle 15 for injecting a core material, which projects toward the skin material reservoir 13. Further, a first runner 17 connecting the first hot runner nozzle 14 and the skin material nozzle 21 of the injection device (FIG. 1), a second hot runner nozzle 15 and a core material nozzle 22 of the injection device (FIG. 1) are connected. The second runners 18 to be connected together are hot runners.

In this example, as shown in FIG. 1, in addition to the two sandwich molding gates 11, one single material gate 10 for the skin material is provided side by side. And a skin material part 802. The single material gate 10 has a first
It is connected to the fourth runner 19 branched from the runner 17 (FIG. 2), and the fourth runner 19 is also a hot runner.

Each sandwich molding gate 11 is connected to the third runner 12 shown in FIG. Then, as shown in FIG. 2, a first hot runner nozzle 14 for injecting a skin material is provided upstream of the third runner 12, and a skin material reservoir 13 is provided downstream thereof. A second hot runner nozzle 15 is provided so as to project toward the skin material reservoir 13.

The first hot runner nozzle 14 and the second hot runner nozzle 15 are, as shown in FIG. 1, skin material nozzle 21, core material nozzle 22, first and second runners 17 and 18 (FIG. 2). ) Are connected by. The first and second runners 17 and 18 are inserted through the hot runner blocks 31 and 32, respectively.

On the other hand, as shown in FIG. 3, the single material gate 10 is connected to the fourth runner 19 branched from the first runner 17 (FIG. 2), and the fourth runner 19 is provided in the hot block 31. Insert it. In FIGS. 2 and 3, reference numeral 33
Is a heater for heating.

One of the skin materials injected from the skin material nozzle 21 (FIG. 1) reaches the third runner 12 from the first runner 17 through the first hot runner nozzle 14 as shown in FIG. Is injected from the single runner 17 into the cavity 16 through the fourth runner 19 from the first runner 17, as shown in FIG.

On the other hand, the core material injected from the core material nozzle 22 (FIG. 1) reaches the third runner 12 from the second runner 18 through the second hot runner nozzle 15 as shown in FIG. Then, in the skin material reservoir 13, a sandwich-shaped resin having a core material is formed in the core portion of the skin material. Then, the sandwich resin is injected from the sandwich molding gate 11 into the cavity 16.

Next, the effect of the multi-point gate mold apparatus 1 of this example will be described. Cold runner, third runner 12
Is provided close to the sandwich molding gate 11, and the runner length is short because the size is sufficient to provide the skin material hot runner nozzle 14, the core material hot runner nozzle 15, and the skin material reservoir 13. Very little resin material is wasted.

The number of the skin material nozzles 21 and the number of the core material nozzles 22 of the injection device are respectively one, and the structure of the injection device is extremely simple. Since the first, second, and fourth runners 17, 18, and 19 are all hot runners, the pressure loss in the runners is reduced and each gate 10,
A resin flow for molding can be supplied to 11 with a good injection pressure. Therefore, the injection pressure of the injection device can be made relatively low, and the resin pressure injected into the cavity 16 can be made high and uniform.

As a result, a good quality molded product can be produced even for a large molded product. As described above, according to this example, waste of material can be reduced, a single material molding part can be easily provided in addition to the sandwich molding part, and a large molded product can be supported. It is possible to provide an easy multi-point gate mold device.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a multi-point gate mold device according to an embodiment.

FIG. 2 is a cross-sectional view of a main part around a sandwich molding gate of a multi-point gate mold device of an example (a cross-sectional view taken along the line AA of FIG. 1).

FIG. 3 is a cross-sectional view of a main part around a single material gate of a multi-point gate mold device of an embodiment (cross-sectional view taken along the line BB in FIG. 2).

FIG. 4 is a cross-sectional view of a main part of a conventional sandwich molding die device.

5 is a configuration diagram when a hot runner is used in FIG.

[Explanation of symbols]

 1. ． ． Multi-point gate mold device, 11. ． ． Sandwich molding gate, 12. ． ． Third runner, 14. ． ． First hot runner nozzle, 21. ． ． Skin material nozzle, 22. ． ． Core material nozzle,

Claims (2)

[Claims] 1. A multi-point gate mold apparatus having a sandwich molding gate for forming a sandwich-shaped molding portion having a core material as a core, wherein the third runner directly connected to the sandwich molding gate has: A first hot runner nozzle for injecting a skin material into the third runner, a skin material reservoir located downstream of the first hot runner nozzle, and a first core material injecting portion projecting toward the skin material reservoir. Two hot runner nozzles are provided, and the first hot runner nozzle is connected to the skin material nozzle of the injection device, and the second hot runner nozzle and the core material nozzle of the injection device are connected. A multi-point gate mold apparatus for sandwich molding, characterized in that the second runners to be connected are both hot runners. 2. The single-material gate for forming a single-material molding part made of only a skin material or a core material is provided in addition to the sandwich molding gate according to claim 1, and the single-material gate is the first material gate. A multi-point gate mold device for sandwich molding, which is connected to a fourth runner branched from a first runner or a second runner.