JPH10156868A - Concurrent in-mold decorating with injection molding method and device for this process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a decorated sheet to be smoothly introduced into the cavity face of a female die and brought into contact tightly with each other, and thereby obtain a injection moldings which are free from the distortion of a pattern on the decorated sheet and are of a high precision. SOLUTION: A groove part 30a with a curved surface is formed on the surface of a female die 30, and a projecting part 50a with a curved surface corresponding to the groove part 30a of the female die 30 is formed on the surface of a sheet clamp 50. In addition, a pair of sheet guide grooves 82 are provided in the groove part 30a with a curved surface of the female die 30. Further, the both side ends of a decorated sheet 15 are held by a sheet pinching means 88 consisting of paired pinching parts 88a, and a rotative body on one of the pinching parts 88a travels in the sheet guide groove 82. The rotative body on one of the pinching part 88a of the sheet pinching means 88 travels in the paired sheet guide groves 82, resulting in the smooth supply of the decorated sheet 15 while it is curved with the female die 30. As the decorated sheet 15 is curved, it is possible to bring the decorated sheet 15 into contact tightly with a cavity face 31a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for simultaneous painting by injection molding, in which painting is performed on the surface of a molded article at the same time as injection molding, and more particularly, to the surface of a molded article having relatively large surface curvature and uneven steps. The present invention relates to a method and an apparatus suitable for performing appropriate painting.

[0002]

2. Description of the Related Art It is possible to manufacture a molded article 13 having a design 11 or a character 12 formed on a surface thereof, for example, as shown in FIG. Is being done. For this simultaneous injection molding painting, an injection molding simultaneous painting apparatus 10 as shown in FIG.
(See JP-A-59-31130, JP-B-4-42172, etc.).

[0003] This injection molding simultaneous painting apparatus 10 comprises a female mold 2
0, and a male mold 25 arranged opposite to the female mold 20. The female mold 20 is provided with a cavity 21 having a molding cavity surface 21a corresponding to the outer shape of the molded body to be obtained, and is provided with an intake hole 22 opening to the cavity surface 21a. The female die 20 is advanced and retracted in a direction approaching / separating from the male die 25 by an advance / retreat device 23 composed of a cylinder or the like. Also,
The male mold 25 has a core 26 inserted into the cavity 21, and a pouring hole (gate) 27 of the molten resin injection device is provided therein. A hot platen 29 is arranged between the female mold 20 and the male mold 25 so as to be able to advance and retreat.
The hot platen 29 has a front surface (the female mold 20 side) as a heating surface.

In order to perform painting simultaneously with injection molding using such an injection molding simultaneous painting apparatus 10, first, a female mold 20 is required.
The painting sheet 15 is arranged opposite to the molding cavity of
The painted sheet 15 is heated and softened by the hot platen 29 (FIG. 7). Next, the painted sheet 15 is transferred to the female mold 20 and the hot platen 2.
9, the opening surface of the cavity 21 is closed, vacuum is drawn through the suction holes 22 provided in the female mold 20, and, if necessary, through ventilation holes (not shown) provided in the hot platen 29. Supply compressed air.

As a result, as shown in FIG. 8, the painted sheet 15 is stretched along the inner peripheral surface of the cavity 21 and is brought into close contact therewith. This step is generally called preforming.

Subsequently, the hot platen 29 is retracted from between the two molds 20 and 25, and the female mold 20 is moved forward as shown in FIG.
Injection molding is performed by injecting and filling a molten resin into a cavity space formed between the female mold 20 and the male mold 25 through a pouring hole 27 of an injection device provided in the male mold 25.

As a result, the painted sheet 15 in the female mold 20 is
When the mold is opened after the injection molding is completed, the molded body having the painting sheet 15 adhered to the outer surface is taken out of the mold.

Here, when the painted sheet 15 is a laminated film (laminated film), it means that the painting is performed as it is, and the whole layer of the painted sheet 15 is adhered and integrated on the outer surface of the molded product P. It becomes a decorative layer. On the other hand, when the painting sheet 15 is a transfer film,
In a subsequent step, only the base film of the painted sheet 15 integrated with the outer surface of the molded body P is peeled off, and a transfer layer such as a picture layer is left on the molded body P side to serve as a decoration layer, so that painting is achieved. Complete.

[0009]

In the conventional simultaneous injection molding painting method, the painting sheet 15 is arranged on the opening side of the molding cavity 21 of the female die 20 as described above, and this is evacuated or the core 26 By pressing the sheet 15 from the flat surface to the inner peripheral surface (cavity surface) 21 of the cavity 21 in a short time by pushing the sheet 15 into the molding cavity 21,
Are stretched at high speed in the cavity 21. Female mold 2
The extension amount of the painting sheet 15 in the cavity 21 of 0 is
The larger the unevenness level and the curvature of the surface of the molded article 13 are, the larger it becomes. In addition, when the sheet is stretched at a high speed, the stress distribution cannot be sufficiently dispersed and relaxed, and is locally concentrated. When the painted sheet 15 is locally stretched greatly, the pattern layer or the like formed on the sheet is naturally stretched and greatly distorted to the extent that it cannot be ignored. In the case where a desired displacement cannot be obtained on the surface of the molded article 13 or the
5 may be wrinkled or torn.

By previously heating and softening the painted sheet 15 using the hot platen 29 as described above, the disadvantages associated with the stretching of the painted sheet 15 can be avoided to some extent. In the case of molding the molded article 13 having a large curvature, the amount of stretching and the amount of drawing of the painted sheet 15 become large, so that wrinkles and distortions are easily generated in the painted sheet 15 and it is difficult to perform painting as expected. . Also, in order to deform the heat-softened painted sheet with a large amount of stretching and squeezing, for example, if the stretching speed is reduced for stress relaxation, the sheet will be distorted by its own weight before reaching the cavity surface. Deformation becomes remarkable.

The present invention has been made in view of such a point, and it is possible to appropriately apply a picture to a molded product having a large surface unevenness step or a large curvature without large distortion or positional deviation. An object of the present invention is to provide a simultaneous injection molding painting method and an apparatus therefor.

[0012]

According to the first aspect of the present invention,
A step of inserting the painting sheet while bending it substantially along the cavity surface of the curved female mold, a step of holding the painting sheet in the female mold in a state of being curved substantially along this cavity surface, Heating the painting sheet held by the heating means to soften the painting sheet; bringing the painting sheet into close contact with the cavity surface; combining the female mold and the male mold to perform mold clamping; A step of performing injection molding by injecting and filling a molten resin between the mold and a step of adhering the injection molded article and the painted sheet, when the painted sheet is inserted while being curved, the sheet provided in the female mold A simultaneous painting method for injection molding, characterized in that a painted sheet is clamped from both sides by a sheet clamping means running along a guide groove.

According to a second aspect of the present invention, there is provided a female mold having a cavity surface and an intake hole opened in the cavity surface,
A male clamp having a resin pouring hole disposed opposite to the female mold, a sheet clamp having a curved protruding portion, and holding the painted sheet between a cavity peripheral portion of the female mold, and a painted sheet. A sheet supply means for supplying to the cavity side of the female mold, and a heating means for heating the painted sheet, provided with a pair of sheet guide grooves in the female mold, along each sheet guide groove,
Sheet holding means for gripping both side edges of the painted sheet is provided so as to be able to travel, the sheet holding means is composed of a pair of holding portions, and one holding portion has a rotating body mounted in a sheet guide groove, and the other holds. The holding part has a rotary body that comes into contact with the sheet clamp, and is a simultaneous injection molding and painting apparatus.

As described above, according to the first aspect of the present invention, the painting sheet is held by being inserted into the female mold in a state where the painting sheet is sandwiched from both sides by the sheet sandwiching means and curved substantially along the cavity surface. Then, the painted sheet can be smoothly brought into close contact with the cavity surface by heating the painted sheet with a heating means. Therefore, when the painted sheet is brought into close contact with the cavity surface, the design of the painted sheet is not distorted.

According to the second aspect of the present invention, both ends of the painted sheet are gripped by the sheet holding means comprising a pair of holding parts each having a rotating body, and one of the holding parts of the sheet holding means is rotated. By moving the body along the inside of the sheet guide groove provided in the female mold, the painted sheet can be smoothly inserted and curved substantially along the cavity surface. Therefore, the painted sheet can be heated by the heating means while being held by the female mold and the sheet clamp, and can be brought into close contact with the cavity surface.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views showing a method and apparatus for simultaneous painting by injection molding according to the present invention.

First, an injection molding simultaneous painting apparatus will be described with reference to FIG. As shown in FIG. 1, the simultaneous molding apparatus for injection molding includes a cavity 3 having a cavity surface 31a.
1 and a female mold 30 having an intake hole 22 opened in the cavity surface 31a, and a male mold 40 arranged opposite to the female mold 30 and having a core portion 42 and a resin pouring hole 27 (FIGS. 4 and 5). See). The cavity surface 31a of the female mold 30 has a semi-cylindrical shape with the x-axis as a central axis. As shown in FIG. 1, a sheet clamp 50 is provided between the female die 30 and the male die 40 for holding the painting sheet 15 between the female die 30 and the cavity peripheral portion 31 b of the female die 30.

The sheet clamp 50 includes left and right holding frames 52.
a, 52b, and upper and lower holding frames 51a, 51b,
An opening 80 is formed in each of the holding frames 52a, 52b, 51a, 51b. The left and right holding frames 52a and 52b of the sheet clamp 50 are provided with semicircular curved protrusions 50a having the x-axis as a central axis. In the sheet clamp 50, a flexible planar heating element 60 described later is provided.
Is provided, and a slit 53 is formed to bend into substantially the same shape as the painted sheet 15 held by the female mold 30.
As shown, the slit 53 is open on the side where the sheet heating element 60 is inserted (upward in FIG. 1), and in the sheet clamp 50, the feeding direction of the sheet heating element (downward in FIG. 1). It is expanding toward. Also, at both ends of the slit 53,
A guide groove 54 is formed. The slit 53 may penetrate the lower holding frame 51b of the sheet clamp 50, or the surface heating element 60 may cover the opening 80 without it. Furthermore, the seat clamp 50 is provided with a sliding rod 57.
The sheet clamp 50 is connected to the female mold 30 through a parting surface outside the cavity 31 of the female mold 30 so as to move toward and away from the female mold 30 by a sliding rod 57 that slides through the parting surface. Has become.

The surfaces around the cavity of the female mold 30 (collectively referred to as parting surfaces) are located vertically and have upper and lower parting surfaces 31c, 31c fitted (joined) with the opposing upper and lower pressing frames 51a, 51b. And left and right parting surfaces that are fitted to the curved projections 50a, 50a that are located on the left and right sides of the cavity and that face each other. On the left and right parting surfaces, x corresponding to the protrusion 50a of the sheet clamp 50 is provided.
A semicircular curved groove portion 30a having the axis as the central axis is formed, and a pair of groove members 82a each having a sheet guide groove 82 is provided on the surface of the curved groove portion 30a. The depth of the groove 30a of the female mold 30 from the upper and lower parting surfaces 31c is substantially the same as the height of the projection 50a of the sheet clamp 50, but is smaller than the depth of the cavity 31. The curvature of the groove 30a of the female mold 30 is smaller than the curvature of the cavity surface 31a. In addition, female mold 30
Cavity 31 of the upper and lower and left and right parting surfaces
Is referred to as a cavity peripheral portion 31b. Here, a ring groove 92a (see FIGS. 1 to 4) is formed, and an O-ring 92 is fitted into the ring groove 92a. The female die 30 is provided with an intake pipe 33 communicating with the intake hole 22.

Above the female die 30, a painting sheet unwinding roll 16 for sequentially supplying a long strip-shaped painting sheet 15 is provided, and the painting sheet unrolling roll 16 from the painting sheet unwinding roll 16 is a pair. Are supplied to the cavity 31 side of the female mold 30 through the feed rollers 17 and 17. The painted sheet 15 supplied from the feed rollers 17, 17 to the cavity 31 side of the female die 30 is configured such that both side ends thereof are sandwiched by sheet sandwiching means 88.

The sheet nipping means 88 is fixed to a wire 87 fed by a sheet nipping means unwinding roll 90, and the sheet nipping means unwinding roll 90 is driven by an electric motor 91.
The wire 87 is fed out by rotating the sheet holding means 88, and the sheet holding means 88 is lowered. The sheet holding means 88 has a pair of holding portions 88a and 88b which hold both side ends of the painting sheet 15 and are connected to each other by a rotating shaft 89 such as a hinge. Next, the sheet holding means 88 will be described in detail with reference to FIGS.
As shown in FIG. 2 and FIG. 3, rotating bodies 93a and 93b each composed of a bearing or a pulley are attached to the pair of grip portions 88a and 88b of the sheet holding means 88, respectively. Among them, the rotating body 93a of the one grip portion 88a on the female die 30 side is mounted in the sheet guide groove 82,
The rotating body 9 of the other grip portion 88b on the sheet clamp 50 side
3b can be brought into contact with the contact surface 101 of the sheet clamp 50. Also, between the pair of grips 88a, 88b,
Spring 1 for urging a pair of grips 88a and 88b in the closing direction
00 is attached. For this reason, the pair of grip portions 88a and 88b are urged in the closing direction by the force of the spring 100 so as to clamp the painted sheet 15 (FIG. 2), and the sheet clamp 50 is moved toward the female mold 30. After the shift, the rotating body 93b of the other grip portion 88b is
0 by contacting the contact surface 101 of the pair of gripping portions 8.
8a and 88b are opened (FIG. 3).

After the leading end of the picture sheet 15 sent from the feed roller 17 is detected by the position sensor 83, the tip end of the picture sheet is gripped by the pulling chuck 86 and pulled downward. Although not shown, the pulling chuck 86 is moved in the sheet feeding direction (the vertical (Z) direction in FIG. 1) by means such as a fluid pressure cylinder mechanism.

Further, a cutter guide rail 84 is disposed above the female die 30 in a horizontal direction, and a sheet cutter 85 runs along the cutter guide rail 84.

A sheet heating element 60 is inserted into the slit 53 of the sheet clamp 50, and both side ends of the sheet heating element 60 are sandwiched by gripping portions 64. Is connected to a pulley 65.

Incidentally, the female die 30 described above is
The female mold 30 fixed to the moving board 34 moves to the fixed male mold 40 side. The unillustrated sheet unwinding roll 16 and the sheet pinching means unwinding roll 90 are fixed to the moving platen 34, though not shown, and move together with the female die 30.

Next, the operation of the present invention having such a configuration will be described. FIG. 1 is a diagram showing a state in which the previous molding cycle has been completed and the next molding cycle has been started. In FIG. 1, the female mold 30 and the male mold 40 (not shown in FIG. 1) are separated from each other.
7 protrudes, so that the sheet clamp 50 also becomes the female mold 3.
Away from zero. The flexible planar heating element 60 is waiting above the sheet clamp frame. In addition, painting sheet 15
Is unwound from a painting sheet unwinding roll 16, and the leading end of the painting sheet 15 is located at a position where it is fed from a feed roller 17. In addition, the tip of the painting sheet 15 is gripped by a tension chuck 86.

As shown in FIG. 1, a pair of left and right wires 8 unwound by a sheet pinching means unwinding roll 90 is provided.
A plurality of sheet sandwiching means 88 are connected to the sheets 7 and 87 at predetermined intervals, and the wires 87 maintain an interval slightly wider than the width of the painting sheet 15. Each sheet holding means 8
The pair of holding portions 88a, 88b of the female mold 8
Waiting above.

Next, a new molding cycle is started from such a state. That is, as shown in FIG. 1, a long strip-shaped painting sheet 15 is unwound from the painting sheet unwinding roll 16, and the leading end of the painting sheet 15 is detected by the position sensor 83. Next, the tip of the painting sheet 15 is pulled downward (z direction) by the tension chuck 86, and
The leading end of the sheet 5 reaches even lower than the lowermost one of the sheet holding means 88. At this time, both ends of the painted sheet pass between the pair of open grips 88a and 88b.

Next, the pair of holding portions 88a and 88b of each sheet holding means 88 are closed, and the pair of holding portions 88a and 88b are closed.
Both ends of the painting sheet 15 are gripped between 8b.

In this case, each of the sheet holding means 88 is provided with a rotating body 93b provided at the tip of the other grip portion 88b.
Is pressed by a driving means such as a solenoid or a hydraulic cylinder to open the pair of grips 88a and 88b. Next, after receiving both ends of the painted sheet 15 between the pair of grips 88a and 88b, the driving means is released, and the pair of grips 88a and 88b are closed by the spring 100.

At the same time, the pulley 65 connected to the holding portion 64 for holding the both ends of the sheet heating element 60 while the sheet heating element 60 descends is moved to the guide groove 54 of the sheet clamp 50.
To enter. When the pulley 65 enters the guide groove 54 in this manner, the sheet heating element 60 is inserted into the slit of the sheet clamp 50.

Next, the leading end of the painting sheet 15 is further pulled downward by the pulling chuck 86. In this case, the rotating body 93a of one gripping portion 88a of each sheet holding means 88
Smoothly travels in the sheet guide groove 82 of the female mold 30, and thus, the painted sheet 15 is
It curves along the surface of 0a.

As shown in FIG. 1, the shape of the grooves 30a formed on the left and right side parting surfaces 31b, 31b of the female mold 30 is similar to the shape of the cavity 31 of the female mold 30. The depth from the upper and lower parting surfaces 31c, 31c is smaller than the depth of the cavity 31. The curvature is set to be equal to or smaller than that of the cavity surface 31a. For this reason, the painted sheet 15 curved along the surface of the groove 30a of the female die 30
It is also in a state substantially along the cavity surface 31a. Thus, the cavity 31 of the female mold 30 is covered with the painting sheet 15. At this time, the depth of the groove 30a and the value of the radius of curvature are as deep as possible within a range that can be sufficiently deformed without wrinkles, tears, etc. even when the painted sheet 15 is bent without heating and softening. Is preferably selected to be approximately the same as the cavity surface.

At the same time, the pulley 65 connected to the holding portion 64 for holding the sheet heating element 60 enters the guide groove 54 of the sheet clamp 50. In this case, the planar heating element 60 is curved to have substantially the same shape as the projection 50a of the sheet clamp 50, that is, to have substantially the same shape as the painted sheet 15 on the surface of the groove 30a of the female die 30.

Next, the position sensor 83 detects that the painting sheet 15 has reached a predetermined position, and the pulling action by the pulling chuck 86 stops. Thereafter, the pulling chuck 86 retreats from the painted sheet 15, and instead, the leading end of the painted sheet 15 is gripped by a fixing chuck (not shown) provided below the female mold. The pulling chuck 86 separated from the painting sheet 15 then rises and reaches the standby position above the female mold 30.

Next, the sliding rod 57 is retracted toward the female mold 30 (y direction). As a result, after the sheet clamp 50 moves to the female mold 30 side, the sheet clamp 50 contacts and fits with the female mold 30, and the painted sheet 15 is sandwiched between the female mold 30 and the sheet clamp 50. In this case, the sheet clamp 50 is in close contact with the O-ring 92 of the female die 30 with the picture sheet 15 therebetween,
The inside of the cavity 31 of the female mold 30 is sealed.

Further, the sheet clamp 50 is brought into contact with the female mold 30, and the painted sheet 15 is brought into contact with the female mold 30 and the sheet clamp 5.
By sandwiching the sheet heating member 60 between 0 and 0, the sheet heating element 60 in the sheet clamp 50 can be arranged at a predetermined distance from the painted sheet 15. In addition, sheet clamp 50
The contact surface 101 and the rotating body 93b of the other grip portion 88b contact each other to open the pair of grip portions 88a and 88b, and the sheet holding means 88 is released from the painted sheet 15.

Next, the wire 87 is wound by the sheet holding means unwinding roll 90, and the sheet holding means 88 is
, And waits at a standby position above the female mold 30. In this manner, the sheet holding means 88 is withdrawn from the sheet guide groove 82 of the female die 30.

Thereafter, the sheet cutter 85 runs along the cutter guide rail 84 in the width direction of the painting sheet.
The sheet 15 is cut by the sheet cutter 85. The travel of the sheet cutter 85 is performed by, for example, a rack and pinion mechanism or an air cylinder. The reason for cutting the painting sheet 15 in this way is that the painting sheet 15
This is to prevent deformation and wrinkles that occur during pre-molding and injection molding from going back to the upstream side of the sheet and deforming the painted sheet 15 used for the next molding.

Thereafter, the sheet unwinding roll 16 is taken up, whereby the painted sheet 15 is returned to the standby position, and the leading end of the painted sheet 15 is gripped by the tension chuck 86.

In the meantime, the sheet with image 15 is uniformly heated and softened by the sheet heating element 60 in the sheet clamp 50. This heating is performed in a non-contact manner, mainly by radiant heat. After the heating and softening of the painted sheet 15 is completed,
The sheet heating element 60 is pulled up from inside the sheet clamp 50. Then, the sheet heating element 60 waits above the sheet clamp 50.

Next, the female mold 30 is driven by a vacuum pump (not shown).
Intake hole 22 in cavity surface 31a through intake pipe 33 of
Then, the softened painted sheet 15 adheres to the cavity surface 31a to perform preforming.

Next, the female mold 30 fixed to the moving board 34 is
It moves together with the sheet clamp 50 to the side of the male mold 40 fixed to the fixed platen 44, and the female mold 30, the sheet clamp 50 and the male mold 40 are united to perform mold clamping (FIG. 4). At this time, the sheet clamp 50 is formed by the core 42 of the male mold 40.
The slit 53 and the guide groove 54 are sealed. Next, the injection resin flows from the resin pouring hole 27 of the male mold 40 into the cavity 31 between the female mold 30 and the male mold 40 through the opening 80 of the sheet clamp 50, and is thus molded by the injection resin. Article 13 (see FIG. 6) is obtained. in this case,
At the same time that the molded article 13 is molded, the pattern 1
One or letter 12 is attached.

Thereafter, the sliding rod 57 is extended and the female mold 30 is extended.
Are separated from the seat clamp 50 and the male mold 40, and thus the female mold 30, the seat clamp 50 and the male mold 40 are separated.
Is opened. After the female mold 30, the sheet clamp 50 and the male mold 40 are opened, the molded product 13 is taken out from the female mold 30. In this case, the molded article 13 can be easily taken out by extruding the molded article from the female mold 30 or the sheet clamp 50 side by using an extraction rod (not shown).

The flexible planar heating element 60 is formed by arranging a heating element formed by, for example, spirally winding a thin resistance wire around a glass fiber cord in a predetermined pattern, and reinforcing the heating element with glass fiber. A sheet heater formed by setting and vulcanizing between two thin silicon rubbers,
Alternatively, a sheet heater such as a sheet heater formed by forming a coating layer of a resistor on a heat-resistant resin substrate and covering the surface with an electric insulating layer is adhered to a thin elastic steel plate. It has a thickness of about 2 mm, and a uniform temperature distribution can be obtained by energization. Flexible planar heating element 6
A gripping portion 64 is fixed to both sides of the gripping portion 64 by means such as screwing over a predetermined length from the lower end portion.
A pulley 65 is rotatably attached to the end of the pulley. Instead of the pulley 65, a guide member which is slid and guided without rotating in the guide groove may be used. The sheet heating element 60 is most preferably a single continuous body having flexibility as a whole. However, in addition to this, it is also possible to use a structure in which a heating element made of a short shelf-shaped rigid plate that extends in a direction (width direction) perpendicular to the heater feeding direction and has a short dimension in the sheet feeding direction is hinged. I can do it.

As described above, according to the present embodiment, the female mold 30
A pair of sheet guide grooves 8 is formed in the curved groove portion 30a on the surface of
2 and the rotator 93a of one grip portion 88a is inserted into the sheet guide groove 82 so that the
Is curved along the groove 30a.
Can be smoothly adhered to the cavity surface 31a of the female mold 30 with a lesser step than the cavity shape and with a curvature equal to or smaller than the cavity shape. Preforming starts from this curved state. For this reason, the amount of deformation (stretching amount) and the stretching speed applied to the sheet at the time of preforming in which the painted sheet 15 is attached to the cavity surface 31a of the female mold 30 are small. Therefore, compared with the case where the preform is performed at once from the flat surface to the surface of the cavity surface 31a, the local stress of the painted sheet is sufficiently dispersed and relaxed throughout the sheet, so that the local portion of the painted sheet is extremely distorted or torn. , Design 1 attached to molded article 13
1st etc. will not be distorted or deformed.

In the above-described embodiment, an example has been shown in which the sheet holding means 88 is fed vertically downward from the sheet holding means unwinding roll 90 (see FIG. 1). However, the present invention is not limited to this, and as shown in FIG. The sheet pinching means unwinding roll 90 is arranged near the picture unwinding roll 16, and the sheet pinching means 88 is unwound from the sheet pinching means unwinding roll 90 in a substantially horizontal direction. 30 and one of the gripping portions 8
The rotating body 93a of 8a may be made to enter. In this case, a sheet cutter 85 may be provided in the vicinity of the painting sheet unwinding roll 16 as shown in FIG.

Although the example in which the position sensor 83 for detecting a predetermined position of the painting sheet 15 is provided has been shown, the position sensor 83 may be omitted when the pattern of the painting sheet does not need to be positioned. Further, a pair of grip portions 88a, 8 of the sheet holding means 88 are provided.
The opening and closing operation of 8b can also be performed by suction and repulsion by an electromagnet.

Although the example in which the sheet holding means 88 is connected to the wire 87 has been described, the invention is not limited thereto, and a chain may be used instead of the wire 87.

The cavity surface 31a of the female mold 30, the groove 30a, and the projection 50a of the sheet clamp 50 are formed in a semi-cylindrical shape with the x-axis (FIG. 1) as the center axis. May be a semi-cylindrical shape having a central axis. The shapes of the groove 30a and the protrusion 50a are, in addition to the cylindrical shape,
Other shapes such as an elliptical column and a hyperbolic column may be used.

Further, an example has been shown in which the painted sheet 15 is supplied to the cavity 31 side of the female mold 30 and the sheet heating element 60 is inserted into the sheet clamp 50 at the same time. Supply, then female mold 3
The sheet heating element 60 may be inserted into the sheet clamp 50 after the painted sheet 15 is sandwiched between the sheet clamp 50 and the sheet clamp 50. The sheet cutter 85 may use a heating wire, a laser beam such as a carbon dioxide gas laser, or the like, in addition to the above-described blades. And the position of the sheet cutter,
In addition to the position as shown in FIG. 1, it can be provided on the surface of the upper clamp frame 51a of the sheet clamp 50 that is in contact with the female die 30.

The painting sheet to be used may be any of a laminated film and a transfer film.

As an injection molding method, besides a method of injecting a hot-melt resin and cooling and solidifying it, a reactive injection molding method of injecting a resin liquid which is hardened by a liquid chemical reaction at room temperature and hardening by a chemical reaction may be used.

[0056]

As described above, according to the present invention, first, the painting sheet can be smoothly placed on the female mold in a state of being curved substantially along the cavity surface of the female mold. Next, after heating the painting sheet with a heating means while holding the painting sheet with respect to the female mold, the painting sheet can be brought into close contact with the cavity surface. That is, preforming is performed in two stages. For this reason, when the painted sheet is brought into close contact with the cavity surface, the pattern of the painted sheet is not distorted or broken even in the case of a molded product having a large unevenness on the cavity surface and a large curvature. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an injection molding simultaneous painting apparatus according to the present invention.

FIG. 2 is an enlarged view showing a closed state of sheet holding means.

FIG. 3 is an enlarged view showing an open state of the sheet holding means.

FIG. 4 is a diagram showing a tightened state of a female mold, a sheet clamp, and a female mold.

FIG. 5 is a diagram showing a modification of the present invention.

FIG. 6 is a view showing a molded product obtained by a conventional simultaneous injection molding painting method.

FIG. 7 is an operation view of a conventional simultaneous injection molding painting apparatus.

FIG. 8 is an operation diagram of a conventional simultaneous injection molding painting apparatus.

FIG. 9 is an operation diagram of a conventional simultaneous injection molding painting apparatus.

[Explanation of symbols]

 15 Painted sheet 16 Sheet unwinding roll 30 Female mold 31 Cavity 31a Cavity surface 40 Male mold 50 Sheet clamp 53 Slit 60 Planar heating element 82 Sheet guide groove 88 Sheet holding means 88a Gripping section 88b Gripping section 93a Rotating body 93b Rotating body

Claims (2)

[Claims] A step of inserting a picture sheet while curving it substantially along the cavity surface of the curved female mold; and holding the picture sheet in the female mold so as to curve substantially along the cavity face. A step of heating and softening the painted sheet held by the female mold by heating means; a step of bringing the painted sheet into close contact with the cavity surface; and a step of combining the female mold and the male mold to perform mold clamping. A step of performing injection molding by injecting and filling a molten resin between the female mold and the male mold, and adhering the injection-molded product and the painted sheet. And simultaneously holding the picture sheet from both sides by sheet holding means running along a sheet guide groove provided in the apparatus. 2. A female mold having a cavity surface and an air intake opening to the cavity surface, a male mold disposed opposite the female mold and having a resin pouring hole, and a curved projection. A sheet clamp for holding the painting sheet between the peripheral edge of the cavity of the female mold, sheet supply means for supplying the painting sheet to the cavity side of the female mold, and heating means for heating the painting sheet; A pair of sheet guide grooves are provided, and along each of the sheet guide grooves, sheet holding means for gripping both side edges of the painted sheet is provided so as to be able to travel, and the sheet holding means comprises a pair of grip portions, and one grip portion is provided. A simultaneous injection molding and painting apparatus, comprising a rotating body mounted in the sheet guide groove, and the other gripping portion having a rotating body abutting on a sheet clamp.