JPH07237235A - Forming of laminated molding and molding device - Google Patents

Abstract

PURPOSE:To enhance the molding accuracy of a skin material and save a resin material by reducing the pressure of a molten resin near a gate, in a method for forming a laminated molding integrally in a mold press-forming die using a resin core material and a skin material and a molding device. CONSTITUTION:A decompression block 61 is installed on the top force 30 of a die which corresponds to a gate 32 provided on a bottom force 30, and at the same time, the decompression block 61 is caused to ascend by a slight stretch of size using a drive cylinder 6 when forming a molding by a mold press. Thus the resin pressure near the gate 32 is reduced to eliminate the adverse effect of a pressure applied to a skin material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a laminated molded article suitable for manufacturing automobile interior parts such as door trims for automobiles, and a molding apparatus used for the molding.

[0002]

2. Description of the Related Art Conventionally, the structure of automobile interior parts such as automobile door trims, rear corner trims, etc., which are installed in the body panel of an automobile, will be described by taking the automobile door trim shown in FIG. 7 as an example. Is a resin core material 2 molded to have a desired curved surface shape,
The resin core material 2 is laminated and integrated on the front surface side, and is formed of a laminated molded body with a skin material 3 having good cushioning properties and decorative properties.

As a method of molding the resin core material 2,
Recently, since a complicated three-dimensional shape is required for molding, a mold press molding method having excellent moldability tends to be used frequently.

In this case, for the purpose of shortening the molding process, when the resin core material 2 is press-molded, the skin material 3 is used.
Are integrated with the surface side of the resin core material 2.

That is, as shown in FIG. 8, first, the skin material 3 is set in advance on the set pin 4a of the upper mold 4 for mold press molding, and the lower die 5 for mold press molding is molded with the skin material 3. When the upper mold 4 is lowered and the clearance between the upper and lower molds 4 and 5 reaches 10 to 20 mm, the upper mold 4 is lowered from the injection molding machine 6 through the hot runner 5a and the gate 5b which are formed in the lower mold 5 for mold press molding. The molten resin M is distributed and supplied onto the mold surface of the mold 5, and then the upper and lower molds 4 and 5 are engaged and compressed to mold the resin core material 2 into a required shape as shown in FIG. The skin material 3 is integrated on the surface side of the resin core material 2, and the automobile door trim 1 shown in FIG. 7 is molded into a product shape.

A time chart diagram of the upper mold 4 for mold press molding in this series of mold press molding steps is shown.
As shown in FIG. 10, the upper die 4 descends from the uppermost position (a) and descends until the upper and lower dies 4, 5 reach a predetermined clearance (b).

Then, the molten resin M is distributed and supplied onto the mold surface of the lower mold 5 between (b) and (c).

After that, the upper die 4 descends from (c) to (d), and the upper die 4 reaches the maximum descending point.

During the period from (d) to (e), mold press molding is usually performed for 40 to 45 seconds, and then the upper die 4 is lifted from (e) to (f) to complete a series of molding cycles. Is completed.

[0010]

However, in the conventional method of forming a laminated molded product by integrally press-molding the resin core material 2 and the skin material 3 by mold press molding as described above, the skin material 3 is a molten resin. The heat of M or the press pressure is easily affected, and this tendency is remarkable especially near the gate 5b.

Therefore, conventionally, it has been dealt with by reducing the pressure to perform mold press molding or using an expensive grade of the skin material 3 which is excellent in heat resistance and rigidity resistance. When the mold press molding is carried out, the material of the resin core material 2 must be used in a large amount, and also when the expensive grade of the skin material 3 is used, similarly, a significant cost increase is caused. Has been pointed out.

The present invention has been made in view of the above circumstances, and in a molding method and a molding apparatus for a laminated molded body in which a resin core material and a skin material are integrated by a mold press molding method, a molten resin is used. By reducing the resin pressure near the injection gate, it is possible to save molten resin material, downgrade the skin material, and to prevent molding defects of the skin material as much as possible. It is intended to be provided.

[0013]

In order to achieve the above object, the present invention provides a resin core material formed by molding a molten resin into a required shape in a mold press molding die, and a mold press molding of the resin core material. At this time, in the method of forming a laminated molded body composed of a resin core material and a skin material integrated with the resin core material, a decompression block is installed in the upper mold corresponding to the gate provided in the lower mold, and the upper mold is lowered to the maximum. After reaching the point, after a predetermined time, the depressurizing block is elevated to partially reduce the resin pressure of the molten resin in the vicinity of the gate.

Further, according to the present invention, a molten resin is molded and press-molded into a required shape to mold a resin core material,
At the time of mold press molding of this resin core material, in a molding apparatus for a laminated molded body in which the resin core material and the skin material are integrated,
The molding apparatus includes a lower mold for mold press molding having a desired mold surface, an injection molding machine that is connected to the lower mold and supplies molten resin onto the mold surface of the lower mold, and the lower mold and mold engagement. It is configured to move up and down as much as possible and is composed of a mold press molding upper mold having a desired mold surface.The mold press molding upper mold corresponds to the gate provided in the lower mold. The pressure reducing block is inserted thereinto, and the pressure reducing block is configured to be vertically movable by a driving cylinder.

[0015]

[Function] As is apparent from the above configuration, the upper mold has the depressurizing block movable up and down corresponding to the gate installation location provided in the lower mold, and the upper mold is at the maximum descending point. After a predetermined time has elapsed since the temperature reached, the pressure reducing block rises by a predetermined dimension, and the resin pressure near the gate can be reduced.

Therefore, the adverse effect of the pressure of the resin applied to the skin material can be eliminated.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for molding a laminated molded body and a molding apparatus therefor according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an automobile door trim manufactured by the method of the present invention, FIG. 2 is a sectional view showing the construction of a molding apparatus according to the present invention, and FIGS. 3 to 5 show each step of the method of the present invention. 6 is a time chart diagram of a molding cycle in the method of the present invention.

In FIG. 1, an automobile door trim 10 manufactured by the method of the present invention comprises a resin core material 11 formed into a required shape and a skin material 12 laminated and integrated on the surface side of the resin core material 11. It is roughly composed of.

More specifically, the resin core material 11 is made of polypropylene resin mixed with talc, is distributed and supplied in a molten state into a mold for press molding having a desired curved shape, and is then subjected to mold press molding. It is shaped into a complicated curved surface.

As the skin material 12, various specifications may be used depending on the application, but in this embodiment, a laminated sheet having a polypropylene foam backing on the back surface of the vinyl chloride sheet is used.

Next, the structure of a molding apparatus for molding the above-described automobile door trim 10 by mold press molding will be described.

As shown in FIG. 2, the molding apparatus 20 has
A lower mold 30 for mold press molding having a desired mold surface,
An upper mold 40 for mold press molding which is located above the lower mold 30 and has substantially the same mold surface, and a mold which is connected to the lower mold 30 and which is the material of the resin core material 11 is melted on the mold surface of the lower mold 30. The injection molding machine 50 for supplying the resin M and the depressurization mechanism 60 installed in the upper mold 40 are generally configured.

More specifically, in the injection molding machine 50, the nozzle 51 is connected to the lower die 30, and the nozzle 51 is passed through the hot runner 31 and the gate 32 which are punched in the lower die 30.
Thus, the molten resin M is distributed and supplied to predetermined positions on the mold surface of the lower mold 30 through the hot runner 31 and the gate 32.

The supply amount of the molten resin M is adjusted by opening / closing the valve 33.

Next, the upper mold 3 located above the lower mold 30.
0 is connected to the upper plate 41, and the upper plate 41 and the upper mold 40 are vertically movable by a predetermined stroke by the operation of the lifting cylinder 42 connected to the upper plate 41.

Further, set pins 43 for setting the skin material 12 are provided at a plurality of locations around the upper die 40.

Next, the pressure reducing mechanism 60 installed on the upper mold 40.
Has a cylindrical depressurization block 61 inserted in the upper mold 40 corresponding to a plurality of installation locations of the gates 32. The upper end of the depressurization block 61 is connected to a drive cylinder 62. 62 is fixed to the upper plate 41 via a bracket 63.

The decompression block 61 has a diameter of 40 to
It is set to 200 mm.

The configuration of the molding apparatus 20 according to the present invention has been described above. The molding process of the automobile door trim 10 shown in FIG. 1 using the molding apparatus 20 will be described with reference to FIGS. 3 to 5. .

First, as shown in FIG. 3, when the upper die 40 for mold press molding is at the uppermost position, this upper die 40
The skin material 12 is set on the set pin 43 of.

Thereafter, as shown in FIG. 4, the lifting cylinder 42 operates to move the upper plate 41 and the upper mold 40.
Is lowered by a predetermined stroke, and when the clearance between the upper and lower molds 30 and 40 reaches 10 to 20 mm, the upper mold 40 is stopped and the molten resin M is passed from the nozzle 51 of the injection molding machine 50 through the hot runner 31 and the gate 32. Is lower mold 3
It is distributed and supplied to a plurality of points on the mold surface of 0.

Simultaneously with the supply of the molten resin M, the upper mold 40 is further lowered, and as shown in FIG.
The molten resin M is molded into a required shape by press-fitting pressure of 60 to 80 kg / cm ² by engagement pressure tightening of 0 and 40, and the resin core material 11 is molded, and on the surface side of the resin core material 11. The skin material 12 is integrated.

At this time, the lower surface of the pressure reducing block 61 is
Although it constitutes a part of the mold surface of the upper mold 40, after the upper mold 40 reaches the maximum descending point, 3 to 10 seconds, preferably about 5 seconds have elapsed, the driving cylinder 62 operates and 1 ~ 5
mm, preferably about 2 mm, and the decompression block 61 rises.

Therefore, although the resin pressure in the vicinity of the gate 32 tends to become excessively large, the resin pressure in the vicinity of the gate 32 can be reduced by raising the depressurizing block 61, and the skin material 12 is excessively pressed from the molten resin M. No pressure is applied and the skin material 12 is not damaged.

FIG. 6 is a time chart diagram of the upper mold 40 in the above mold press molding process.

That is, the upper mold 40 at the maximum upper position (a)
Is lowered to (b), the molten resin M is supplied from (b) to (c), and then the upper mold 40 is lowered again from (c) to (d) to move the upper mold 40. Reaches the maximum descent point.

Then, from (d) to (e), usually 5
After clamping the upper and lower molds 30, 40 for about a second,
The depressurization block 61 rises to reduce the resin pressure in the vicinity of the gate 32, press-molds up to (f), and then the upper mold 40 rises from (f) to (g).

As described above, according to the method of the present invention, the depressurizing mechanism 60 composed of the depressurizing block 61 that is vertically moved by the driving cylinder 62 is installed in the upper mold 40 so that the resin can be used during the mold press molding. Since the damage to the skin material due to the pressure can be prevented, there is an effect that the molding accuracy of the skin material 12 can be improved.

Further, since it is possible to partially reduce the pressure near the gate 32, it is not necessary to reduce the entire molding pressure, so that the molten resin M can be saved, the weight can be reduced, and the material of the skin material 12 can be reduced. There is also an advantage that a low-priced grade can be used, resulting in cost reduction.

[0041]

As described above, according to the present invention, the following operational effects are achieved.

(1) By installing a pressure reducing mechanism in the upper mold for mold press molding, the resin pressure near the gate can be reduced and damage to the skin material near the gate can be prevented as much as possible. This has the effect that the molding accuracy of the material can be increased.

(2) Since it is possible to partially reduce the pressure in the vicinity of the gate, it is not necessary to reduce the overall mold press molding pressure, so that the amount of molten resin material can be minimized and the grade of the skin material is also reduced. Since low-priced grades can be used without using expensive heat-resistant grades, the cost of the skin material can be reduced, which contributes to weight reduction, and has the effect of significantly reducing the product cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of an automobile door trim manufactured by the method of the present invention.

FIG. 2 is a sectional view showing a configuration of an embodiment of a molding apparatus according to the present invention.

FIG. 3 is a sectional view showing a step of setting a skin material in the method of the present invention.

FIG. 4 is a sectional view showing a step of supplying molten resin in the method of the present invention.

FIG. 5 is a sectional view showing a mold press molding step in the method of the present invention.

FIG. 6 is a time chart diagram of an upper die for mold press molding in the method of the present invention.

FIG. 7 is a cross-sectional view showing a configuration of a conventional automobile door trim.

FIG. 8 is a cross-sectional view showing a step of setting a skin material in a conventional mold press molding method.

FIG. 9 is a cross-sectional view showing a press in a conventional mold press molding method.

FIG. 10 is a time chart diagram of a press upper die in a conventional mold press molding method.

[Explanation of symbols]

 10 Automotive Door Trim 11 Resin Core Material 12 Skin Material 20 Molding Device 30 Lower Mold for Mold Press Molding 32 Gate 40 Upper Mold for Mold Press Molding 42 Elevating Cylinder 50 Injection Molding Machine 60 Pressure Reduction Mechanism 61 Pressure Reduction Block 62 Drive Cylinder M Molten resin

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area B29L 31:58

Claims (2)

[Claims] 1. A resin core material (11) formed by molding a molten resin (M) into a required shape in a mold press molding die (30, 40), and at the time of mold press molding of the resin core material (11), Skin material (12) integrated with resin core material (11)
In the method for forming a laminated molded body including the above, a decompression block (61) is installed on the upper mold (40) corresponding to the gate (32) provided on the lower mold (30), and the upper mold (40) is After reaching the maximum descent point of (1), the depressurizing block (61) is moved up a predetermined time to partially reduce the resin pressure of the molten resin (M) near the gate (32). And a method for forming a laminated molded body. 2. A molten resin (M) is molded and press-molded into a required shape to mold a resin core material (11), and when the resin core material (11) is molded and press-molded, a resin core material (11) is formed. In a molding apparatus for a laminated molded body, which is integrally formed with a skin material (12), the molding apparatus (20) comprises a lower mold (30) for mold press molding having a desired mold surface, and the lower mold (30). ), An injection molding machine (50) for supplying the molten resin (M) onto the mold surface of the lower mold (30), and a vertically movable installation so that the lower mold (30) can be engaged with the mold, The upper die (40) for mold press molding having a desired die surface is provided with a gate (32) provided in the lower die (30) in the upper die (40) for mold press molding. Correspondingly, the decompression block (61) is inserted, and the drive cylinder (6 )
The depressurizing block (61) is configured to be movable up and down according to the above.