JPH10230530A - Apparatus for producing decorated molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorated molded product producing apparatus capable of molding even a deep drawing product in relatively uniform wall thickness under vacuum so as to closely bring a decorative sheet into contact with the cavity surface of a mold and not generating trouble such as the deterioration of weatherability or the non-uniform stretching of a pattern without increasing the thickness of a sheet material. SOLUTION: A press core 5 inserted in the gap between opened molds 1, 2 to move toward the mold 1 to press a decorative sheet S to perform the preparatory stretching of the sheet is provided and recessed and projected structures 12, 54 capable of being mutually fitted so as to provided a predetermined gap therebetween are formed to the periphery of the sheet pressing part of the press core 5 and the periphery of the cavity surface 1a of the mold 1 to press the decorative sheet S clamped to the mold 1 in such a state that the press core 5 is always positioned with respect to the mold 1 to enhance the symmetry of the thickness distribution of the sheet S after prestretching.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a decorative molded product using a decorative sheet. The decorative sheet is insert-molded by injecting molten resin into the cavity while the decorative sheet is in close contact, or the decorative sheet is printed on the sheet as a transfer sheet. The present invention relates to an apparatus for transferring a portion to a molded article surface.

[0002]

2. Description of the Related Art There is known an in-mold molding method in which a decorative sheet is brought into close contact with a cavity surface in advance during injection molding, and the decorative sheet is insert-molded on a surface portion of a molded product. In this molding method, generally, a decorating sheet such as a laminating sheet supplied between molds in an open state is softened by heating, and then the cavity surface of one mold is evacuated. Etc. so that they adhere to each other,
A method is adopted in which a mold is clamped and a molten resin is injected into a cavity.

[0003] In the above-mentioned method, a transfer layer such as printing laminated on the transfer sheet can be transferred to the surface of a molded article by using the decorating sheet as a transfer sheet.

In a conventional apparatus employing the above-described decorative molding method, specifically, as shown in a cross-sectional view in FIG. 7, the material is supplied between molds 701 and 702 in an open state.
The heating sheet 704 is moved closer to the decoration sheet S clamped to one of the molds (female mold) 701 by the sheet clamp 703, so that the decoration sheet S is heated by the radiant heat. The decorative sheet S in a softened state is brought into close contact with the cavity surface of the mold 701 by evacuating the decorative sheet S through a vacuum device through an air passage 705 formed in the mold 701. Used.

[0005]

However, the above-described conventional method has the following problems. That is, after the decorative sheet S is heated, it is shaped by vacuum forming so as to be in close contact with the cavity surface of the mold 701. At this time, the decorative sheet S is formed by the mold 701.
, The stretched state becomes non-uniform, and a phenomenon occurs in which the thickness of a portion where the contact of the sheet S with the mold 701 is delayed, such as a deep drawing portion, becomes thin. When the sheet S becomes thin, various problems occur when covering the product. For example, when a printed transfer sheet is used, the pattern may not be in a desired shape due to uneven stretching of the sheet, or, particularly when a film subjected to a weather-resistant formulation is used, the film may be targeted. If it is thinner, the weather resistance will decrease accordingly, and the thickness of the material film before stretching must be increased in order to secure the minimum thickness required to obtain the required weather resistance, and the cost There is a problem that leads to up.

The present invention has been made in view of such circumstances, and even in the case of a deep drawn product, a decorative sheet having a relatively uniform wall thickness can be formed similarly to a product having a simple surface shape which is not so. It can be vacuum formed so as to be in close contact with the cavity surface of the mold, so that the required weather resistance can be exhibited without increasing the thickness of the material film, and defects such as uneven spreading of pictures It is an object of the present invention to provide an apparatus for manufacturing a decorative molded product that does not cause any problem.

[0007]

The structure for achieving the above-mentioned object will be described with reference to FIGS. 1 to 3 showing an embodiment. A pair of molds 1 and 2, a sheet supply mechanism 3 for supplying a decorative sheet S between the molds 1 and 2 in an open state, and the supplied sheet S to one mold 1. A clamping mechanism 4 for positioning, and a heating device (not shown) for heating the sheet S in the clamped state are provided, and the decorative sheet S after heating is placed in the one mold 1 by vacuum molding. In order to adhere to the cavity surface 1a of the mold 1,
An air passage 11 communicating with the vacuum device is formed, and the decorative sheet S is brought into close contact with the cavity surface 1a, and the mold is clamped to inject the molten resin into the cavity.
In a decorative molded product manufacturing apparatus for integrally molding the resin and the decorative sheet S or transferring the transfer layer of the decorative sheet S to the surface of the molded product, the mold is opened and closed between the molds 1 and 2. By moving to the one mold 1 side in the inserted state, a pressing core 5 for pressing and pre-stretching the decorative sheet S in the clamped state is provided, and a sheet pressing portion of the pressing core 5 is provided. By forming a concavo-convex structure (for example, the positioning pin 54 and the positioning recess 12) that can be fitted to each other under a predetermined gap, around the periphery and around the cavity surface 1a of the one mold 1. Characterized.

According to the present invention, the decorative sheet S preliminarily stretched by the pressing core 5 before the heat-softened decorative sheet S is vacuum-formed, so that the deep-drawn product S In order to make the wall thickness uniform, the decorative sheet S positioned with respect to one of the molds 1 by the clamp mechanism 4 is pre-stretched. Pressing core 5 that moves and presses sheet S
Is moved in a state of being accurately positioned under certain conditions with respect to the mold 1, so that the distribution of the stretching of the decorative sheet S with respect to the cavity surface shape of the mold 1 is always constant, and after the vacuum forming, This is to improve the symmetry of the sheet thickness.

That is, after the decorative sheet S is clamped and heated by the clamp mechanism 4 and then the pressing core 5 is pressed against the sheet S toward the mold 1, the pressing core 5 and the periphery of the sheet pressing portion of the pressing core 5 are removed. Due to the fitting of the concavo-convex structure provided around the cavity surface 1a of the mold 1, the pressing core 5 is constantly pressed against the decorating sheet S while being positioned with respect to the mold 1 with constant accuracy. Can be Since the distribution of the amount of stretching of the decorative sheet S due to the pressing of the pressing core 5 is in accordance with the pressing position, the pressing core 5 and the mold 1 are appropriately positioned, and The decorative sheet S positioned by the clamp mechanism 4 is pressed and pre-stretched, so that the thickness distribution of the pre-stretched decorative sheet S and, consequently, the decorative sheet S can be in close contact with the cavity surface 1 a of the mold 1. The thickness distribution of the decorative sheet S after being vacuum-formed is uniform in the vertical and horizontal directions, and the thickness of the sheet S after vacuum forming is more than in the case of pre-stretching without positioning. It is possible to make it uniform.

Here, the uneven structure for positioning the pressing core and the mold in the present invention, particularly,
The dimensions are not limited, and a concave portion or a convex portion may be formed in either the mold or the pressing core. However, the concave portion may be formed in a peripheral portion of the cavity surface of the mold or a sheet of the pressing core. A method of directly engraving the peripheral portion of the pressing portion can be employed. Also, as a method of forming the convex portion, the peripheral portion of the cavity surface of the mold or the peripheral portion of the sheet pressing portion of the pressing core is also used. A method of inserting and fixing another member such as a pin into the portion, or a method of directly processing the corresponding portion to form a protruding portion can be adopted. In addition, the cross-sectional shape of the unevenness is circular,
Any shape, such as a rectangle, may be used as long as it can fit into each other. As for the cross-sectional dimension of the unevenness, a diameter or a vertical and horizontal dimension of about 5 to 100 mm is appropriate, and the depth or the protruding length depends on the depth of the mold 1,
It is appropriate that the distance is 5 to 50 mm from the tip of the pressing core.

[0011] The positioning accuracy between the mold and the pressing core by the concavo-convex structure depends on the dimensions of the mold and the pressing core, but the intended purpose is achieved by setting the accuracy to approximately ± 1 mm or less. be able to.

[0012] Further, the uneven structure may be disposed at the periphery of the cavity surface of the mold or at the four corners around the sheet pressing portion of the pressing core, or by providing irregularities of an arbitrary cross-sectional shape, or as two opposing sides. Irregularities having an elongated rectangular cross section may be provided. Further, when the size of the mold is particularly large, the positioning accuracy can be improved by increasing the number of sets of unevenness or increasing the length of one unevenness.

In addition to the structure in which one protrusion is simply fitted into the other recess, the protrusion / recess structure according to the present invention has a structure in which one protrusion projects from the main body (a mold or a pressing core) in the projecting direction. It is also possible to adopt a structure in which one of the main body portions is slidably supported with the protrusion portion being a guide while the tip portion is fitted and positioned in the other recess portion. (See FIGS. 4 to 6).

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partial sectional side view showing a main part of an embodiment of the present invention, showing a state before the pressing of a decorative sheet S by a pressing core 5 is started, and FIG. That A
FIG. FIG. 3 is a partial cross-sectional side view showing a state in which the decorative sheet S is pressed by the pressing core 5.

Of the pair of dies 1 and 2 facing each other,
One mold (female mold) 1 is mounted on a mounting plate 10 for a movable die plate of an injection molding machine, and the other mold (male die) 2 is mounted on a mounting plate 20 for a fixed die plate. The mold 1 is closed when the mold 1 side approaches the mold 2 side from the state of FIG. In addition, an air passage 11 communicating with a vacuum device is formed in the mold 1 for vacuum-forming the decorative sheet S, and the mold 2 has
A resin flow path 21 for injecting a molten resin into a cavity formed by the molds 1 and 2 in a mold-clamped state is formed.

Above the mold 1, a sheet roll 31 around which the decorative sheet S is wound, and a sheet feeder 32 for feeding the decorative sheet S downward from the sheet roll 31 at a constant pitch. The sheet supply mechanism 3 is provided. Each time the injection molding is completed and the mold is opened in the mold-clamped state, the sheet supply mechanism 3 supplies a required amount of the decorative sheet S close to the parting surface of the mold 1. .

The mold 1 is provided with a frame 42 which is moved back and forth by the ejector device 41 with respect to the parting surface of the mold 1 so that the decorative sheet S can be moved around its periphery. A sheet clamp mechanism 4 for clamping the mold 1 is formed. That is, the decorative sheet S is supplied by the sheet supply mechanism 3 in a state in which the frame body 42 has moved forward from the state of FIG. 1 (a state moved to the right in the figure), and then, as shown in FIG. 42 is retracted so that four sides around the frame 42 and the mold 1
And is positioned and fixed with respect to the mold 1. In the clamped state by the frame 42, the decorative sheet S is cut by the cutter 33 disposed above the mold 1.

Although not shown, a heating plate equivalent to that illustrated in FIG. 7 and a moving mechanism thereof are provided above or on the sides of the dies 1 and 2, and the dies 1 and 2 are provided as described above. After the decorative sheet S is clamped against the decorative sheet S, the heating plate is inserted between the open molds 1 and 2 so as to face the decorative sheet S. The sheet S is heated.

After the heating of the decorative sheet S by the heating plate is completed, as shown in FIG. 1, the pressing core 5 is inserted between the dies 1 and 2 in the opened state. The pressing core 5 is attached to the distal end of an arm 50 in a state where the pressing core 5 is integrated with a flat supporting member 51. The arm 50 includes a vertical movement mechanism 52 and an anteroposterior movement mechanism using an electric motor as an actuator. 53 allows movement in the up-down direction and the mold clamping direction. Under such a configuration, the pressing core 5 is inserted between the molds 1 and 2 by the lowering of the arm 50 driven by the vertical movement mechanism 52 as shown in FIG. , Together with the support member 51 to the mold 1 side. In addition, this pressing core 5
It may be heated to an appropriate temperature by a built-in heater or the like.

A horizontal positioning pin 54 is fixed to each of the four corners surrounding the pressing core 5 on the supporting member 51 integrated with the pressing core 5. Further, a total of four horizontal positioning recesses 12 are formed at positions around the cavity surface 1a of the mold 1 corresponding to the four positioning pins 54, respectively. As shown in FIG. 2, the positioning pins 54 and the positioning recesses 12 are located outside the decorative sheet S clamped to the mold 1 by the frame 42.

The inner diameter of each positioning recess 12 is slightly larger than the outer diameter of each positioning pin 54, and the amount of projection of each positioning pin 54 from the support member 51 is different from that of the support member 51 of the pressing core 5. When the pressing core 5 is moved closer to the mold 1 by a predetermined amount than the projecting amount of the pressing core 5, the positioning pins 54 are first inserted into the corresponding positioning recesses 12, and then the pressing core 5 It is considered that the leading end abuts on the decorative sheet S.

Each of the positioning recesses 12 has a tapered surface which opens toward the positioning pin 54 at an entrance portion thereof. A tapered surface is formed so as to close toward the end.

With the above arrangement, when the pressing core 5 and the supporting member 51 are moved toward the mold 1 by driving the longitudinal movement mechanism 53 from the state shown in FIG. The pressing cores 5 are fitted into the recesses 12 while being guided by the tapered surfaces of the respective molds.
The pressing core 5 is pressed against the decorating sheet S in the positioned state as shown in FIG. By appropriately setting the fitting accuracy of each positioning pin 54 and each positioning recess 12, the pressing core 5 is always positioned with a certain accuracy with respect to the mold 1, and the pressing core 5 The decorating sheet S in the heated and softened state clamped by the mold 1 is pressed and preliminarily stretched.

According to the pre-stretching in the embodiment of the present invention, the decorative sheet S clamped and heated with respect to the mold 1 is always positioned with respect to the mold 1 under a constant condition. Since the pre-stretching is performed by being pressed by the pressing core 5, the thickness distribution of the decorative sheet S after the pre-stretching step is substantially uniform in the vertical and horizontal directions with respect to the center of the mold 1.

Next, another embodiment of the present invention will be described. FIG. 4 is a partial cross-sectional side view of the main part configuration, showing a state before the pressing of the decorating sheet S by the pressing core 5 is started, and FIG. 5 is a view along the line AA. FIG. 6 is a partial sectional side view showing a state in which the decorative sheet S is pressed by the pressing core 5.

The feature of this embodiment is that a vertical movement mechanism 52 is provided.
A front-rear movement mechanism 530 using an air cylinder as an actuator is attached to the tip of an arm 500 that moves in the up-down direction according to 0. The configuration, the point that each positioning pin 540 is slidably supported in the axial direction by the support member 51, the flange 541 is fixed to each of the positioning pins 540, and the flange 541 is fixed. A compression coil spring 542 is interposed between the support member 51 and each of the compression coil springs 542 to bias each positioning pin 540 toward the mold 1 side. The point is that the depth of the concave portion 120 is made shallower than the previous example, and the other portions are the same as the previous example.

According to this embodiment, the longitudinal movement mechanism 53
0, the pressing core 5 and the supporting member 51 are moved to the mold 1.
Side, first, the tip portion of each positioning pin 540 fits into the positioning recess 120, and each pin 54
0 is positioned with respect to mold 1. With the further movement of the pressing core 5 and the support member 51, each positioning pin 54
0 abuts against the bottom of each positioning recess 120 and stops,
Next, at the same time as the compression coil spring 542 is compressed and deformed,
As shown in FIG. 6, while the support member 51 is relatively moving with respect to the positioning pins 540, that is, while the support member 51 is guided by the positioning pins 540 positioned with respect to the mold 1, as shown in FIG. The pressing core 5 presses the decorative sheet S.

Also in this embodiment, the decorating sheet S is positioned with the pressing core 5 positioned with respect to the mold 1 by the positioning pins 540 and the positioning recesses 120.
Is pressed and stretched, it is possible to achieve the same operation and effect as the above example.

Tables 1 and 2 show examples in which the decorative sheet S was actually pre-stretched and the thickness distribution was examined using the above embodiments of the present invention, together with comparative examples.

[0030]

[Table 1]

In this [Table 1], Example 1 is shown in FIGS.
Example 2 shows a case where the embodiment shown in FIG. 3 is used, and Example 2 shows a case where the embodiment shown in FIGS. 4 to 6 is used. In Comparative Example 1, the same device as in Example 1 was used except that the positioning pin 54 was not used. In Comparative Example 2, the same device as in Example 2 was used, except that the positioning pin 540 was not used. An example of stretching is shown.

Table 1 shows that the decorative sheet S is a methyl methacrylate sheet (sheet thickness 0.125 m).
m) During the in-mold molding of a symmetrical product using the above method, the decorative sheet S is heated and pre-stretched, and then vacuum-molded so as to be in close contact with the cavity surface 1a of the mold 1,
Decorative sheet S at half the height of the entire product
3 shows the result of measuring the thickness of the right and left sides.

As is clear from Table 1, in Examples 1 and 2 using each embodiment of the present invention, the thickness of the decorative sheet S after vacuum forming differs only by 5 μm or less on the left and right. However, in Comparative Examples 1 and 2 in which the pressing core and the mold were pre-stretched without being positioned, the thickness of the decorative sheet S after vacuum forming was different by 20 μm or more on the left and right. Thus, the effectiveness of the present invention was confirmed.

[0034]

As described above, according to the present invention, the mold on which the decorative sheet is clamped, and the pressing core that moves back and forth with respect to the mold to press the decorative sheet, In the state of being positioned relative to each other by the uneven structure formed around the sheet pressing portion of the pressing core and the cavity surface of the mold, the decorating sheet in a heat-softened state before vacuum forming is pressed by the pressing core. As a result, the decorative sheet is always preliminarily stretched by being pressed against the mold in a fixed positional relationship, and the thickness distribution is preliminarily adjusted vertically or horizontally. As a result of the stretching, the thickness unevenness of the decorative sheet after vacuum forming is reduced, and the sheet material thickness required to secure the minimum sheet thickness for obtaining the weather resistance required for the decorative molded product Thinner than before. Becomes possible, it becomes possible to reduce the cost of the sheet. At the same time, since the thickness of the decorative sheet after vacuum forming becomes uniform, when a pattern is transferred to a molded product using a transfer sheet, a problem such as uneven spreading of the pattern does not occur. Further, thinning of the sheet can be avoided, and the occurrence of tears and wrinkles can be prevented.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing a configuration of a main part of an embodiment of the present invention, showing a state before pressing of a decorative sheet S by a pressing core 6 is started.

FIG. 2 is a view taken in the direction of arrows AA in FIG. 1;

FIG. 3 is a partial cross-sectional side view showing a configuration of a main part of the embodiment of the present invention, showing a state in which a decorating sheet S is pressed by a pressing core 6;

FIG. 4 is a partial cross-sectional side view showing a configuration of a main part of another embodiment of the present invention, showing a state before the pressing of the decorative sheet S by the pressing core 6 is started.

FIG. 5 is a view taken in the direction of arrows AA in FIG. 4;

FIG. 6 is a partial cross-sectional side view showing a configuration of a main part according to another embodiment of the present invention, showing a pressed state of a decorating sheet S by a pressing core 6.

FIG. 7 is an explanatory view of a heating process and a vacuum forming process of a decorative sheet in a conventional decorative molded product manufacturing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Die (female type) 10 Mounting plate to movable die plate 11 Air passage 12, 120 Positioning recess 2 Mold (male) 20 Mounting plate to fixed die plate 21 Resin flow path 3 Sheet supply mechanism 4 Sheet clamp Mechanism 42 Frame 5 Pressing core 50, 500 Arm 51 Support member 52, 520 Vertical movement mechanism 53, 530 Front / back movement mechanism 54, 540 Positioning pin S Decorating sheet

Claims (1)

[Claims] 1. A pair of dies facing each other, a sheet supply mechanism for supplying a decorative sheet between dies in an open state, and a clamp for positioning the supplied sheet with respect to one of the dies. A mechanism and a heating device for heating the sheet in the clamped state are provided, and the above-mentioned one mold is evacuated so that the heated decorative sheet is brought into close contact with the cavity surface of the one mold by vacuum molding. An air passage communicating with the apparatus is formed, and the decorative sheet is closely attached to the cavity surface, and the mold is clamped and molten resin is injected into the cavity to integrally mold the resin and the decorative sheet. Or, in a decorative molded product manufacturing apparatus that transfers the transfer layer of the decorative sheet to the surface of the molded product, by moving to the above one mold side while being inserted between the molds in the mold open state ,Up A press core for pressing and pre-stretching the decorative sheet in the clamped state is provided, and a predetermined gap is formed around the sheet pressing surface of the press core and the cavity surface of the one mold. An apparatus for manufacturing a decorative molded product, characterized in that an uneven structure that can be fitted to each other is formed.