JPH06305040A - Method for correction of shape of molded item - Google Patents

Abstract

PURPOSE:To eliminate defects and deformation of a molded item and to enlarge general-purpose properties; by a method wherein a deformable molded item is put in a correcting mold and the molded item is covered with press tools each having a soft press member and the soft press members are expanded between the press tools and the molded item to press the molded item to the correcting mold. CONSTITUTION:A correcting mold 1 fixed on a base stage 10 and a pressing tool 2 driven by means of a cylinder 20 in the approaching and going-away direction to the base stage 10 are provided. Compressed air is introduced into soft press members 21 from an air pump 4 and each soft press member 21 is expanded between a press tool 2 and a molded item 3. In addition, the soft press member 21 expands so as to fill the space in the press tool 2 and the froce acts also in such a direction that the press tool 2 is separated from the base stage 10. However, as the press tool 2 is pressed strongly to the base stage 10 by means of the cylinder 20, the expanding force of the soft press member 21 acts on the molded item 3 and the molded item 3 is pressed by the correcting mold 1 with a force of about 6kg/cm and is fixed by following the shape of the correcting mold 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a method for correcting the shape of a resin molded product.

[0002]

2. Description of the Related Art In the molding of resin molded products, various measures have been taken in order to shorten the molding cycle.
One of them is to remove the molded product during cooling from the mold and to cool it. As a result, the mold can be immediately used for the next molding, and the molding cycle can be shortened.

By the way, in the case of a molded product such as a glove box lid which requires a cushioning feeling, a skin having a foam layer is disposed on the mold surface of the mold, and the base material is molded on the back surface side. Mainly formed by a molding method. However, in the case of such a molded product, since the cooling of the molded base material is delayed due to the heat insulation effect of the foam layer, it takes a long time to remove from the mold. There is also a problem that the molded product is deformed when it is removed from the mold early.

Therefore, conventionally, as shown in FIG. 5, a molded product 100 removed from a mold is placed on a correction mold 101 having a predetermined shape, and a pressing jig 103 having a predetermined shape driven by a cylinder 102 is used to correct the correction mold 101. It is cooled by pressing to correct the shape. As a result, even a molded product having a foam layer can be removed from the mold early and the molding cycle can be shortened.

[0005]

However, in the above-mentioned conventional straightening method, the pressing jig may locally press the molded product, and the molded product has a scratch or a defective shape. was there. In addition, there is a problem that a pressing jig that matches the shape of the molded product is required, which is not suitable for the production of many kinds.

The present invention has been made in view of such circumstances, and it is an object of the present invention to eliminate scratches and deformations of molded articles and to enhance versatility.

[0007]

According to the method for correcting the shape of a molded article of the present invention for solving the above-mentioned problems, a molded article having a deformable temperature is placed on a straightening die having a predetermined shape, and then a balloon-shaped soft pressing is performed. Characterized by covering the molded product with a holding jig having a member and supplying the fluid into the soft pressing member to expand the soft pressing member between the holding jig and the molded product to press the molded product against the correction mold. And

[0008]

In the method for correcting the shape of a molded article of the present invention, for example, the molded article at a deformable temperature during cooling is removed from the mold,
Place on the corrective mold. Then, the molded product is covered with a holding jig having a balloon-shaped soft pressing member, and fluid is supplied into the soft pressing member to expand the soft pressing member between the holding jig and the molded product. At this time, since the pressing jig is in a fixed state, the soft pressing member presses the molded product toward the correction mold as it expands.

Since the soft pressing member is soft, it is first deformed according to the shape of the molded product, and is deformed so as to follow the shape of the correction mold by pressing the molded product against the correction mold as it expands.
Further, since a fluid such as air or water is supplied to the inside of the soft pressing member, the internal pressure acts uniformly on the entire surface of the soft pressing member. Therefore, the molded product is pressed against the straightening mold with a uniform force on the entire surface without any problem such as being locally strongly pressed, and the shape is straightened by cooling as it is.

The cooling rate of the molded product can be further increased by providing a flow path for the cooling water inside the straightening mold or by using a low temperature fluid as the fluid supplied to the inside of the soft pressing member. Then, after the shape of the molded product is corrected, the fluid is drained from the soft pressing member, the pressing jig is removed from the correction mold, and the corrected molded product is removed from the correction mold. The straightening die and the pressing jig are used to straighten the next molded product.

[0011]

EXAMPLES The present invention will be specifically described below with reference to examples. Figure 1
The configuration of the shape correcting device used in one embodiment of the present invention is shown in FIG. This device comprises a straightening mold 1 fixed on a base 10,
The pressing jig 2 is driven by a cylinder 20 in a direction approaching the base 10 and a direction moving away from the base 10.

The straightening mold 1 is provided with a cooling water passage 11,
The molded product 3 placed on the surface of the straightening mold 1 can be cooled. The molded product 3 is a lid for a glove box of an automobile, and as shown in FIG. 2, a PVC skin 30 and a urethane foam layer 31 laminated on the back surface of the skin 30.
And a PP base material 32 integrally formed on the back surface of the foam layer 31.

The holding jig 2 has a box shape, and a plurality of rubber soft pressing members 21 are held inside. The soft pressing members 21 are provided on the inner surface of the pressing jig 2 on five flat surface portions each consisting of a ceiling portion and four side surface portions continuous with the ceiling portion, and each of them has a balloon shape having an air inlet (not shown). Has been formed. In the straightening method of this embodiment using such a straightening device, the heat-deformable molded article 3 during cooling is removed from the molding die (not shown) and placed on the surface of the straightening die 1. Then, the cylinder 20 is immediately driven, and the pressing jig 2 is pressed against the base 10 with a force of 10 t. The state is shown in FIG. At this time, there is a gap between the soft pressing member 21 and the molded product 3, and the pressing force has not yet acted on the molded product 3.

Next, as shown in FIG. 4, pressurized air is introduced from the air pump 4 into the respective soft pressing members 21, so that the respective soft pressing members 21 are pushed between the pressing jig 2 and the molded product 3. Expands. The soft pressing member 21 is a pressing jig 2
It expands so as to fill the inner space, and its force also acts in the direction in which the holding jig 2 moves away from the base 10. However, since the pressing jig 2 is strongly pressed against the base 10 by the cylinder 20, the expansion force of the soft pressing member 21 has a large effect on the molded product 3, and the molded product 3 is corrected with a force of about 6 kg / cm ^2. Pressed by the mold 1.

Further, the cooling water is supplied to the cooling water passage 11 almost at the same time as the introduction of the pressurized air, and the base material 32 in contact with the surface of the straightening mold 1 is efficiently cooled. As a result, the molded product 3 is fixed in a corrected shape following the shape of the correction mold 1.
After cooling to a temperature at which the molded product 3 is not deformed, the soft pressing member 21 is deflated by air and contracts, and the cylinder 20 is driven in the opposite direction, and the holding jig 2 separates from the base 10. Subsequently, the molded product 3 is removed from the correction mold 1, and the next molded product is similarly corrected.

That is, according to the straightening method of this embodiment, the molded product 3 is pressed by the soft pressing member 21 and is pressed by the air pressure, so that the whole is pressed by a uniform force. Therefore, there is no local variation in pressing force, deformation of the molded product 3 is prevented, and scratches are also prevented. It should be noted that although a slight springback occurs in the molded product 3 and does not exactly match the shape of the straightening die 1, the shape of the straightening die 1 is determined in consideration of the springback amount. Further, in this embodiment, the pressurized air is introduced into the soft pressing member 21, but it is also possible to introduce low temperature water or the like to expand the soft pressing member 21. In this way, the molded product 3 is cooled more quickly, so that the straightening cycle can be further shortened.

[0017]

Therefore, according to the shape correcting method for a molded product of the present invention, since the soft pressing member uniformly presses the molded product, there is no problem that the molded product is scratched or deformed. Further, since the soft pressing member is easily deformed following the shape of the correction mold, it is possible to easily follow the shape of the correction mold and press the molded product. As a result, a single pressing jig can correct various molded products, and the versatility is significantly improved.

Due to these effects, even a molded article having a foam layer can be immediately removed from the mold and straightened, so that the molding cycle can be further shortened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a correction device used in an embodiment of the present invention and showing a state before driving.

FIG. 2 is a cross-sectional view of a main part of a molded product used in one example of the present invention.

FIG. 3 is a cross-sectional view showing a correction device used in an embodiment of the present invention, showing a state immediately before correction.

FIG. 4 is a cross-sectional view showing a correction device used in an embodiment of the present invention, showing a state immediately after correction.

FIG. 5 is an explanatory diagram of a conventional correction method.

[Explanation of symbols]

1: Straightening type 2: Holding jig
3: Molded product 4: Air pump 10: Base 1
1: Cooling water passage 20: Cylinder 21: Soft pressing member
31: Foam layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ken Kuroki Aichi Nagasaki, Kasuga-cho, Aichi Prefecture 1 Ochiai, Nagahata, Toyoda Gosei Co., Ltd. (72) Inventor Koji Yamaoka Kasuga, Aichi Pref. Toyoda Gosei Co., Ltd.

Claims (1)

[Claims] 1. A molded article at a deformable temperature is placed on a straightening die having a predetermined shape, and then the molded article is covered with a holding jig having a balloon-shaped soft pressing member, and a fluid is placed in the soft pressing member. Is supplied to expand the soft pressing member between the pressing jig and the molded product to press the molded product against the correction mold.