JPH1034705A - Device and method of in-mold decorating simultaneous with injection molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the positional deviation, drooping, creasing and the like upon cutting a decorating sheet with a simple constitution by a method wherein a heating filament for melting and cutting the belt type decorating sheet in the widthwise direction thereof is provided on a frame type clamper, pushing or fixing the decorating sheet and movable in a direction orthogonal to the parting surface of a female mold. SOLUTION: A frame type clamper 25, pinching a decorating sheet S between the parting surface 12a of a female mold 12 and itself, is connected to a driving and supporting plate 22 by through holes 29 and connecting rods 24 at the four corners of the female mold 12 so as to be advanced and retreated by a driving mechanism 21. A sheet cutting means or a heating filament 30 is provided on the clamper 25. The heating filament 30 is projected from the sheet pushing surface 25a of the clamper 25 toward the female mold 12 at the upstream side end of the clamper 25. The cutting of the sheet is effected utilizing the pushing and fixing operation of the clamper 25 under such a constitution whereby a driving means for moving the cutting means becomes unnecessary and the length of tip end side of the decorating sheet S, which is corresponding to the length of one shot, can be the necessary minimum length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding method in which a painted sheet is integrally adhered to the surface of an injection molded resin article in a mold at the same time as injection molding to obtain a molded article on which patterns, characters, etc. are applied. The present invention relates to an apparatus and method for simultaneous molding and painting.

[0002]

2. Description of the Related Art There have been proposed a number of simultaneous injection molding painting methods in which a painting sheet is integrally adhered to the surface of an injection resin molded article in a mold at the same time as injection molding. Is designed so that all or some of the following steps (a) to (j) are performed in the order described, or the order of the steps is changed, and the steps are sequentially performed or a plurality of steps are simultaneously performed in parallel or in parallel.

(A) A sheet supply step of supplying a picture sheet onto a female parting surface used for injection molding. (B) a clamping step of fixing and holding the painted sheet on the female parting surface; (C) In the case where the painted sheet is a strip-shaped long sheet wound up in a roll shape, one shot of the leading side of the painted sheet supplied up to the female parting surface is taken from the supply side (upstream side). Sheet separation process to be separated. (D) A softening step of heating and softening the painted sheet with a hot plate or the like. (E) A stretching step (preliminary molding step) of stretching the painted sheet along the cavity surface of the female mold by vacuum suction and / or air supply. (F) A mold clamping step of moving one of the female mold and the male mold (usually a female mold) to the other (usually a male mold) to perform mold clamping. (G) An injection molding step of injecting and filling a resin (molten resin) in a flowing state into the cavity from the male mold side to perform injection molding. (H) a mold opening step of separating the female mold and the male mold. (I) A trimming step of separating a part of the painted sheet to be attached to the injection molded product from another part (unnecessary part). (J) a removal step of taking out the injection molded product to which the picture sheet is adhered from the female mold.

[0004] Simultaneously performing a plurality of steps simultaneously means that a plurality of steps are included in one step. For example, in the mold clamping step (f), the painted sheet is divided into a female type and a male type. If it is not fixed and held between them, the clamping step (b) is performed simultaneously with the mold clamping step, and the painted sheet is used in the injection molding step (g). If the stretching is performed by the heat and pressure of the injected molten resin, this means that the stretching step (e) is performed simultaneously with the injection molding step.

[0005] As the painting sheet, either a laminated sheet (laminated sheet) or a transfer sheet is used in accordance with the product type. In the case of a laminated sheet, painting is performed as it is by injection molding. That is, all the layers of the sheet are bonded and integrated with the surface of the injection resin molded product to form a decorative layer. On the other hand, when the painted sheet is a transfer sheet, the support sheet of the decorative sheet integrated with the surface of the injection resin molded product is peeled off, and only the transfer layer such as the decorative layer is placed on the injection resin molded product side. Painting is completed by leaving it as a decorative layer.

By the way, in the simultaneous painting method for injection molding as described above, as described in the above (c), when the painting sheet to be used is a strip-shaped long sheet wound up in a roll shape, The tip of the sheet is pinched by a chuck or the like and one shot of the tip side is supplied onto the female parting surface, and the sheet is pressed and fixed to the female parting surface by a clamper or the like, and then the tip is Often, one shot is cut off from the supply side. For example, Japanese Patent Application Laid-Open
The invention described in Japanese Patent No. 301250 corresponds to this.

[0007] In this case, a cutting means is required for separating one shot from the supply side on the leading end side of the painting sheet. Conventionally, as this cutting means, a cutter for mechanically cutting the sheet has been used. That is, in the related art, a cutter is disposed so as to be able to advance and retreat in a direction perpendicular to the painted sheet on the upstream side of the female sheet supply side end, and the cutter is used to move the painted sheet to the female sheet supply side. Cutting was performed in the width direction at a portion near the end portion (however, outside the space between the male and female molds).

[0008]

However, in the above-described cutting method using a cutter, a cutter and a drive means for moving the cutter forward and backward must be separately provided. As the height increases, more space is required for the device. Since the blade is worn and the sharpness deteriorates with the number of cuts, it is necessary to periodically replace or polish the blade.

Therefore, the applicant of the present application has previously described, for example, as disclosed in JP-A-6-315950, at the sheet supply side end of the hot plate used in the softening step (d) described above. , A heating wire made of a heating wire such as a nichrome wire is stretched in a state of protruding from the heating surface of the heating plate toward the painting sheet side (female mold side), and the heating plate provided with the heating wire is attached to the painting plate. After moving to a position facing the cavity of the female mold covered by the sheet, the sheet is further moved to the painted sheet side (female mold side), and the heating wire is pressed against the painted sheet, thereby removing the painted sheet. There has been proposed an injection molding simultaneous painting apparatus in which the female die is melt-cut in a width direction at a portion near an end on the sheet supply side (see FIGS. 23 and 24 of the above publication).

[0010] In this apparatus, the heating wire as the cutting means is arranged on the hot plate normally provided in the injection molding simultaneous painting apparatus, so that the cutting means can be inexpensive as compared with the apparatus using the cutter. Along with simplifying the device configuration,
Further, there is an advantage that the space occupied by the device can be reduced.

However, in the above-described simultaneous injection molding painting apparatus, a driving means for moving the hot plate provided with the heating wire to the painting sheet side (female mold side) is indispensable in order to cut the painting sheet. Here, in a device in which a hot plate is brought into contact with or close to a painted sheet to heat and soften, a driving means for moving the hot plate to the painted sheet side may be provided in advance, and in this case, a new drive is performed. Although it is not necessary to add means, even in this case, the cost of the apparatus is increased and the structure of the apparatus is complicated as compared with an apparatus without the driving means.

[0012] Further, both of the apparatus using the cutter and the apparatus having the heating wire disposed on the hot plate,
In order to prevent the cutter and the heating wire from interfering with other members such as the female mold, the cutting position of the painted sheet has to be located upstream of the sheet supply side end of the female mold. Therefore, the length of one shot of the painted sheet, particularly the length from the sheet supply side end of the female mold cavity to the cutting portion (the rear end of the one-shot painted sheet) becomes long, and this portion is Is an unnecessary part (surplus part) which is trimmed, and the painting sheet is wastefully consumed, which is uneconomical.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a relatively simple configuration without separately requiring a driving means for moving the cutting means. Thus, it is possible to cut the one shot on the leading end side of the belt-shaped painted sheet to the minimum length required, and there is no displacement of the painted sheet at the time of clamping and cutting, occurrence of wrinkles, wrinkles, etc., and equipment cost, It is an object of the present invention to provide an injection molding simultaneous painting apparatus and method capable of reducing running costs, occupied space, and the like as much as possible.

[0014]

In order to achieve the above-mentioned object, an injection molding simultaneous painting apparatus according to the present invention basically has a direction orthogonal to a female parting surface used for injection molding. A heating filament for melting and cutting the strip-shaped painting sheet in the width direction is disposed on a frame-shaped clamper for pressing and fixing the painting sheet which is movable in the width direction.

More specifically, a female type and a male type, which are arranged to face each other so that one can be moved to the other side, and one shot on the leading end side of a strip-shaped painted sheet wound up in a roll shape And a sheet supply means for supplying a portion of the picture on the female parting surface in a direction orthogonal to the female parting surface. A frame-shaped clamper that is pressed against and fixed to the parting surface of the female mold, and a resin injection unit that injects and fills the resin in a fluid state from the male mold side into the female mold cavity. A heating wire is provided for melting and cutting the painted sheet in the width direction to separate one shot on the leading end side from the supply side.

In this case, the heating wire is stretched to a position protruding from the sheet pressing surface of the clamper toward the female mold, and the cutting of the painting sheet by the heating wire is melted by the clamper. It is preferable to carry out the operation in cooperation with the pressing and fixing operation. In addition, in order to avoid interference between the female mold and the heating wire when the picture sheet is pressed and fixed by the clamper, it is preferable that the female mold is provided with an escape groove capable of accommodating the heating wire.

As the heating wire, a normal heating wire such as a nichrome wire can be used. In this case, the heating wire is connected to a sheet supply side end of the frame-shaped clamper via an appropriate insulating member. , And the painting sheet is melt-cut by energizing the heating wire for a predetermined time after the clamper starts pressing and fixing the painting sheet.

Further, the simultaneous painting method for injection molding of the present invention
Basically, a sheet supply step of supplying one shot of the leading end side of the band-shaped painting sheet wound up in a roll shape onto the female parting surface, and applying the painting sheet to the female parting surface A clamping step of pressing and fixing with a frame-shaped clamper above, a stretching step of stretching the painted sheet along the cavity surface of the female mold, and a mold by moving one of the female mold and the male mold to the other side. A mold clamping step of performing clamping, an injection molding step of performing injection molding by injecting and filling a resin in a flow state from the male mold side into the female mold, and a mold opening step of separating the female mold and the male mold. Taking out the injection-molded product to which the painted sheet is adhered from the female mold, and in which the steps are described in the order described, or the order of the steps is replaced, sequentially, or a plurality of steps are simultaneously overlapped or parallel. To do That.

In addition to the above, in cooperation with the operation of pressing and fixing the painted sheet by the clamper, the strip-shaped painted sheet is melt-cut in the width direction by a heating wire provided on the clamper, and the leading end is cut. It is characterized in that one shot is cut off from the supply side.

In the present invention, the clamper provided with the heating wire can be the same as that provided in a conventional ordinary simultaneous injection molding painting apparatus. In other words, it is only necessary to arrange the heating wire on the clamper of the existing simultaneous injection molding painting apparatus.

As the heating wire, nichrome (nickel-
It is desirable from the viewpoint of price, structure, and control (control of heating temperature and heating time, etc.) to use a heating wire that generates heat when energized, such as a chromium alloy wire. It is a matter of course that other heatable wires such as wires and iron-chromium alloy wires may be used. As the insulator between the heating wire and the clamper, a material having both electric insulation and heat resistance is selected. For example, mica, quartz, porcelain and the like are used.

As described above, the injection molding simultaneous painting apparatus of the present invention is a clamper which can be moved in a direction perpendicular to the female parting surface so as to press and fix the painting sheet on the female parting surface. And a driving means for moving the clamper forward and backward in a direction perpendicular to the female parting surface (painted sheet). In this case, the existing driving means such as the air cylinder for driving the clamper and its control means can be used as they are,
Further, the ejector pin driving means provided in a normal injection molding apparatus can also be used as the clamper driving means.

The male and female molds may be made of metal such as iron or ceramics, and may be divided (provided with an intermediate mold or the like) according to the shape of the molded product. When preforming the painted sheet, a hot plate or the like for heating and softening may be attached, or a small hole (vacuum suction hole, etc.) may be provided for female and male molds for vacuum suction or for supplying compressed air (for preforming). ) Is provided.

In order to position a decorative pattern such as a picture pattern of a painted sheet with a female mold cavity surface (molded product) with high accuracy, for example, a "+"-shaped, "-"-shaped, or "I" -shaped And the like, and the operation of the sheet supply means such as a servomotor may be controlled by detecting the positioning mark with a photoelectric tube, an image sensor, or the like provided around the female mold or on the female mold itself. When high-accuracy positioning is not required (when the painted sheet is plain or the same pattern is repeated), a fixed amount of the sheet is fed by simply controlling the stepping motor or the like of the sheet feeding means. You may do so. It should be noted that a slight tension is applied to the painted sheet by the sheet supply means so that the pictured sheet is peen on the female parting surface so as not to generate slack or wrinkles.

The painted sheet is composed of a base sheet and a decorative layer laminated thereon, and is a laminated sheet (laminated sheet) used as a final product while keeping the base sheet in close contact with the molded product, or Once the painted sheet and the molded article are integrated, any transfer sheet that peels off the substrate sheet (support sheet) while leaving only the decorative layer (transfer layer) on the molded article side can be used.

As the base sheet, a thermoplastic resin such as polyvinyl chloride, acrylic, polystyrene, ABS resin, polycarbonate, polyester, and polypropylene can be used. The thickness of the base sheet is usually 2
It is about 0 to 500 μm. The decorative layer may be a layer having a visual design such as a printed pattern, a colored or transparent coating film, a metal thin film, or a layer having functionality such as a hard coating film, an anti-fog coating film, or a conductive layer. .

ABS (acrylonitrile / butadiene / ABS) is used as a resin in a fluid state injected from the resin injection means.
Injection of thermoplastic resin such as styrene copolymer), polystyrene, polycarbonate, polypropylene, etc., heated or melted, or two-part curing type, catalyst curing type resin, for example, uncured liquid such as polyurethane, unsaturated polyester, etc. Conventionally known materials can be used for simultaneous molding and painting.

In a preferred embodiment of the injection molding simultaneous painting apparatus and method according to the present invention having the above-described configuration, the painting sheet is changed from the state of a long continuous strip-shaped sheet wound into a roll, for example. Required amount (one shot each) by sheet feeding means equipped with a movable chuck etc.
The tip is passed between the clamper and the female die (below the sheet pressing surface of the clamper) so as to cover the cavity and the parting surface of the female die. (A side end portion), and is conveyed to a position near the fixed chuck and fixedly held by a fixed chuck. From this state, the surplus delivery amount is pulled back by the sheet feeding means, and the sheet is arranged on the female parting surface in a stretched state. (Sheet supply step).

Next, the frame-shaped clamper is moved forward to the female mold side (painted sheet side), whereby one shot on the leading end side of the painted sheet is pressed and fixed on the female mold parting surface by the clamper. (Clamping step).
In cooperation with the pressing and fixing operation of the painting sheet by the clamper, the painting sheet is melted and cut in the width direction by the heating wire provided on the clamper, and one shot of the leading end side is separated from the supply side (sheet separating step). ).

That is, when the clamper is moved forward to the female mold side, the heating wire stretched at a position protruding toward the female mold side from the sheet pressing surface (lower surface) of the clamper comes into contact with the painted sheet, and Is slightly pressed. Here, when the clamper is moved forward to the female mold side as described above, the heating wire may collide with the parting surface of the female mold in a state where the painting sheet is interposed therebetween. By providing an escape groove capable of accommodating the heating wire, the collision interference can be avoided, and a portion (a linear portion having a certain width) of the painting sheet that is in contact with the heating wire can be formed as described above. It is pushed into the escape groove.

At this time, the position of the heating wire may be present on the surface of the clamper facing the female die, but in this case, a portion of the sheet upstream of the cut end is fixed by the clamper. In order to leave the cut end upstream side of the sheet to the mold upstream side, a gap is formed between the upstream side of the heating wire of the clamper and the female parting surface by the thickness of the sheet. Ingenuity such as is required. Therefore, more preferably, as in the embodiment described later, the heating wire may be provided so as to slightly protrude upstream of the clamper.
In this case, the cut end of the sheet is pulled upstream without any constraint.

Here, the cut surface (cut line) of the sheet is prevented from meandering, and the sheet near the cut surface (cut line) is distorted by heat or stress at the time of cutting, thereby preventing the unusable portion from expanding. In order to smoothly lift the cut sheet to the upstream side (outside of the mold), the following is preferable.

That is, as shown in FIG. 1, the sheet S is fixed by the lifting / lowering chuck 53 returning to the upstream side from the upper end of the female parting surface, thereby preventing the sheet S from oscillating and generating wrinkles and bulges. The sheet is cut by the heating wire 30 on the upstream side of the clamper 25 in a state where the sheet is fixed by the clamper 25 and the O-ring (FIG. 5). By doing so, the cutting line of the sheet is straight. Then, the take-up roll RS is turned in the reverse direction, and as shown in FIG. 6, while the sheet is fixed by the fixed chuck 55, the sheet cutting terminal is not swung from between the two molds 12 and 40, and To withdraw. This prevents the sheet from being deformed by being pinched between the two dies at the time of mold clamping.

In a preferred embodiment, energization of the heating wire is started in synchronization with the pressing and fixing operation of the clamper, and a predetermined time (for example, 1 second) is maintained even after the pressing and fixing operation of the painting sheet by the clamper is completed.
, The current supply to the heating wire is continued.

In this case, the heating temperature of the heating wire rises according to the energizing time, and a certain time (for example, one second) after the energizing is started.
Elapses, the heat generation temperature reaches a temperature at which the painting sheet can be melted, and the painting sheet is melted and cut at a portion where the heating wire is in contact. At this time, in a preferred embodiment, the portion of the heating wire and the heating sheet of the painting sheet that are in contact with each other is in the clearance groove, and the heating wire penetrates the painting sheet in the thickness direction in the clearance groove. To be cut. Further, the timing of pressing and fixing the sheet and the cutting can be performed simultaneously with the fixing and the cutting, or the cutting after the fixing, but more preferably, the pressing and fixing of the sheet is completed and the position of the sheet is shifted. Disappeared,
The time difference is set so that the cutting occurs after the transient stress generated in the sheet during fixing is sufficiently relaxed.

Accordingly, in the simultaneous injection molding painting apparatus and method of the present invention, a heating wire is used as the cutting means,
Since the cutting of the sheet by the heating wire is performed by using the pressing and fixing operation of the clamper, a separate driving means for moving the cutting means is not required, the configuration is relatively simple, and the apparatus cost, occupied space and the like can be reduced. Can be effectively reduced.

Further, since the painted sheet can be cut at a portion on the cavity side of the sheet supply side end of the female mold, the length of one shot on the leading end side of the strip-shaped painted sheet can be reduced to the minimum necessary length. As a result, the length of the pictorial sheet for the shot (especially, the length of the surplus portion) can be shorter than that of the related art, so that the sheet cost and the running cost per one molded product are reduced.

After the step of cutting the painted sheet is completed, the painting sheet is heated and softened by a hot plate or the like, and the painted sheet is subjected to female suction by vacuum suction and / or compressed air supply. Stretching process (preliminary molding process, in which one of the female mold and the male mold (usually a female mold) is moved to the other (usually a male mold) side to perform stretching along the cavity surface of the mold, and the mold is clamped. A mold clamping process for forming a cavity (molding cavity) between dies, an injection molding process for injecting and filling a resin (melt resin) in a flowing state into the cavity from the male mold side, and performing an injection molding, a female mold and a male mold. The steps such as a mold opening step to be separated are performed in the order of description or the order of the steps is changed, and the steps are sequentially performed or a plurality of steps are simultaneously performed in parallel or in parallel.

[0039]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 and FIG. 2 show a female mold provided in an embodiment of the simultaneous injection-molding and painting apparatus according to the present invention and a peripheral portion thereof.

Injection molding simultaneous painting apparatus 10 of this embodiment
Comprises a female mold 12 having an uneven shape corresponding to a molded product to be obtained, and a male mold 40 described later (shown in a closed state in FIG. 7),
The female mold 12 has its bottom fixed to the movable platen 11, and is arranged in the left-right direction (horizontal direction) in FIG. 1 by the ram 15 of the fluid pressure cylinder, in other words, is arranged on the right side of the female mold 12 in FIG. It is designed to move forward and backward in a direction approaching and separating from the outer male mold 40.

In the present embodiment, the female mold 12 is movable and moves in the horizontal direction as described above. However, the present invention is not limited to this. It is also possible to adopt a mode in which the female molds are vertically opposed and one of them is moved in the vertical direction.

The working chamber 1 provided at the bottom of the female mold 12
An ejector pin (not shown) for discharging the obtained injection-molded product out of the mold is usually arranged at 6.
In the present embodiment, the parting surface 12 of the female mold 12 is used.
a driving mechanism such as a fluid pressure cylinder for driving a frame-shaped clamper 25 (for example, a rectangular shape) that encloses a female cavity (forming cavity) for fixing and holding the painting sheet S in between. 21 and a drive support plate 22 are provided.

The frame-shaped clamper 25 has four connecting rods 24, 24, 2 slidably fitted in through holes 29, 29, 29, 29 provided near four corners of the female die 12.
4 and 24, which are connected to the drive support plate 22 by the drive mechanism 21.
It can move forward and backward in the vertical direction. A heating wire 30 as a sheet cutting means is disposed on the clamper 25 (described later).

A concave cavity (cavity surface) 13 is formed in the female mold 12 in accordance with the shape of the molded product to be obtained, and a vacuum suction passage 17 (simplified in the drawing) is opened to the cavity 13. The vacuum suction passage 17 is connected to an external vacuum pump via a conduit 19. Further, an annular groove 14 in which an O-ring 15 is mounted is formed in the parting surface 12 a of the female mold 12 so as to go around the outer peripheral edge of the cavity surface 13. The O-ring 15 is configured so that the frame-shaped clamper 25 is
When pressed against the second parting surface 12a, it serves to hermetically shut off the cavity 13 from the outside.

On the other hand, the male mold 40 has a fixed platen 44 provided with a mounting portion 43 to which a nozzle 50 of an injection molding machine is mounted, as can be clearly understood from FIG.
The male mold 40 has a convex portion (core portion) 41 protruding at the center thereof, and the molten resin from the nozzle 40 of the injection molding machine is fed into the cavity 13 of the female mold 12. A runner (runner) 42 is formed for injecting and filling the fluid.

Above the female die 12, a take-up roll RS on which a continuous band-shaped picture sheet S is wound, and the necessary amount of the picture sheet S (one shot) is fed from the take-up roll RS. A pair of feed rolls 51 and an elevating chuck 53 for holding and lowering the leading end of the picture sheet S fed out by the feed rolls 51 are arranged, and near the lower end of the female die 12, A fixed chuck 55 for fixing and holding the leading end of the painted sheet S held and pulled down by the elevating chuck 53 is provided.

Further, a hot platen 60 (not shown in FIGS. 1 and 2) for heating and softening the painted sheet S is shown above the female mold 12 (the operating state is shown in FIG. 6).
Is waiting.

The hot platen 60 is attached to the tip of the piston rod 62 of the first hydraulic cylinder 62 via an attachment member 64 so as to be parallel to the parting surface 12 of the female die 12. A heater 61 is housed inside the female mold 12 of the hot platen 60. The hot platen 60 may have a structure in which the sheet is heated by conduction heat in contact with the sheet, or a structure in which the sheet is heated in a non-contact manner by radiant heat while facing the sheet at a predetermined gap from the sheet. Good.

In addition to the above-described configuration, in the present embodiment, the strip-shaped painted sheet S is provided on the upper side (the sheet supply side end) of the frame-shaped clamper 25 in the width direction (the direction orthogonal to the sheet traveling direction). ) Is provided with a heating wire 30 for melting and cutting one shot of the tip side from the supply side. That is, as can be understood by referring to FIG. 3 in addition to FIGS. 1 and 2, a plate-shaped base portion 31 is fixed to the upper end surface of the upper side of the frame-shaped clamper 25. A pair of support rods 32, 32 are vertically and vertically (upward) protrudingly provided at both ends of the sheet 31 with a separation distance longer than the width of the painting sheet S.
Insulating rods 34, 34 each composed of a pair of porcelains on the left and right sides are vertically protruded toward the female mold 12 at the upper end of the rod 2, respectively. A heating wire 30 made of a heating wire is stretched.

In this case, the tip position of the insulating rods 34, 34, that is, the position of the heating wire 30 is projected from the sheet pressing surface 25a of the clamper 25 toward the female mold 12 by α (for example, about 5 mm). I have. The position of the heating wire 30 is β from the upstream end of the clamper 25.
(For example, about 10 mm). The smaller β is, the more excess sheet can be saved.

In order to avoid interference between the female mold 12 and the heating wire 30 when the picture sheet S is pressed and fixed by the clamper 25, the heating wire 30 and the insulating rods 34 An escape groove 36 having a rectangular straight path shape capable of accommodating the front end portion is provided. Further, the heating wire 30 is located between the upper end 18 of the female parting surface and the upstream end of the clamper 25.

As shown in FIG. 4, the heating wire 30 is energized from an external AC power source 90 to a temperature control circuit 94 using a start switch 92 and a triac.
Is to be done through. The start switch 92 is operated by a signal from a control unit (control panel) 100 provided externally.
5, after a predetermined time delay from the start of the pressing and fixing operation of the painted sheet S, the ON state is turned ON for a predetermined time, and the activation switch 92 is turned ON, so that the temperature control circuit 94 , A predetermined current is caused to flow, whereby the heating wire 30 is heated to a temperature at which the painting sheet S can be melted. The delay time is programmed in advance in the timer of the control unit. The delay time is typically a time difference Δt (seconds) from when the pressure for pressing the sheet between the clamper 25 and the female parting surface reaches a steady state until the heating wire 30 reaches the melting temperature of the sheet. ) Is set so as to satisfy about 0 ≦ Δt ≦ 1.

Incidentally, for reference, in this embodiment, the vertical and horizontal external dimensions of the parting surface 12a of the female die 12 are approximately 650 and 500 mm, and the vertical and horizontal external dimensions of the frame-shaped clamper 25 are Approximately 400 / 350mm, vertical and horizontal external dimensions of cavity 13 are approximately 300 / 250m
m, and the vertical and horizontal external dimensions of the hot platen 60 are substantially the same as those of the clamper 25, but the dimensions of each part can be variously set in design.

In addition, the picture sheet S used in this embodiment is an acrylic base sheet (having a thickness of 125
μ) and a wood-grained decorative layer and an adhesive layer printed and laminated thereon, and used as a final product while the base sheet is tightly integrated with the molded product (injection resin molded product). It is a sheet (laminated sheet), and its melting temperature is about 160 ° C.

In the simultaneous injection molding painting apparatus 10 of this embodiment having such a configuration, the painting sheet S is required by the pair of feed rolls 51 from the state of the winding roll RS wound in a roll shape. It is fed out by an amount (one shot at a time), and its tip is held by an elevating chuck 53 to cover the cavity 13 of the female mold 12 and the parting surface 12a. The sheet is conveyed to a position near the sheet discharge side end (lower end) of the female die 12 through the sheet pressing surface 25a of the clamper 25 and is fixed and held by the fixed chuck 55. From this state, the lifting chuck 53 Is released from the sheet holding state and returned to the original position, and the feed roll 51 is reversed, so that the surplus amount of the sheet S with the picture is returned. As a result, the painted sheet S (for one shot on the leading end side) is arranged in a state of being spread on the parting surface 12a of the female die 12 (sheet supply step).

Next, as shown in FIG. 3, the frame-shaped clamper 25 is moved forward by the drive mechanism 21 toward the female die 12 (the side of the picture sheet S). The shots are pressed and fixed on the parting surface 12 of the female die 12 by the clamper 25 (clamping step). In addition, at the start of this clamping step or in a preceding step (sheet feeding step), the elevating chuck 53 and the fixed chuck 55 are moved toward the female mold 12 with the pictorial sheet S held therebetween, so that the pictorial sheet S is 12 may be placed on the parting surface 12a, or the painting sheet S may be moved so as to be pressed against the parting surface 12a using the pressing and fixing operation of the clamper 25.

The painting sheet S is melted and cut in the width direction by the heating wire 30 provided on the clamper 25 in cooperation with the press-fixing operation of the painting sheet S by the clamper 25, and one tip of the painting sheet S is cut. Is separated from the supply side (sheet separating step).

That is, when the clamper 30 is moved forward to the female mold 12 side, the heating wire 30 stretched at a position protruding toward the female mold from the sheet pressing surface 25a of the clamper 30 comes into contact with the picture sheet. And press it slightly. Here, when the clamper 25 is moved forward toward the female mold 12 as described above, the heating wire 30 may collide with the parting surface 12a of the female mold 12 with the painting sheet S interposed therebetween. However, in the present embodiment, the female mold 12 is provided with the escape groove 36 capable of accommodating the heating wire 30, so that the collision interference is avoided as shown in FIG. The portion of S that is in contact with the heating wire 30 (a linear portion having a certain width) is pushed into the clearance groove 36.

Then, in synchronization with the pressing and fixing operation of the clamper 25, the start switch 92 (FIG. 4) is turned ON, and the energization of the heating wire 30 is started. Even after the pressing and fixing operation is completed, the power supply to the heating wire 30 is continued for a predetermined time (for example, one second).

In this case, the heat generation temperature of the heating wire 30 rises in accordance with the energization time, and a certain time (for example, 1
After the elapse of (sec), the heat generation temperature reaches a temperature at which the painted sheet can be melted, and the painted sheet S is melted and cut at a portion where the heating wire 30 is in contact. At this time, the heating wire 30
The portion where the heating wire 30 is in contact with the heating sheet 30 in the painting sheet S is in the clearance groove, and the heating wire is cut so as to penetrate the painting sheet in the thickness direction in the clearance groove. In the present embodiment, since the heating wire 30 projects more upstream than the upstream end of the clamper 25, the upstream side of the cut sheet S can be pulled up without any obstacle. (See FIG. 5).

After the cutting of the sheet is completed, the energization of the heating wire is stopped (the start switch 9 is in the OFF state), and the heating wire is quickly cooled to room temperature. Therefore, the sheet is not cut even if it touches the heating wire except at the time when cutting is required, and there is no fear of burns even if the worker apologizes and touches the heating wire. In addition, wasteful power consumption is suppressed.

Therefore, in the injection molding simultaneous painting apparatus of this embodiment, the heating wire 30 is used as the cutting means,
Since the cutting of the sheet by the heating wire 30 is performed by using the pressing and fixing operation of the clamper 25, no separate driving means for moving the cutting means is required, the configuration is relatively simple, and the apparatus cost and the occupied space are reduced. It can be reduced as much as possible.

Further, since the painted sheet S can be cut at a position closer to the cavity 13 than the sheet supply side end (upper end) 18 of the female die 30, one shot of the belt-shaped painted sheet S on the leading end side can be cut to the necessary minimum length. As a result, the length of the one-shot pictorial sheet can be shorter than that of the conventional sheet, so that the sheet cost and the running cost per molded product can be reduced.

After the cutting step of the painted sheet S is completed in this way, as shown in FIG. 6, the hot platen 60 is brought close to the female mold cavity surface 13 to soften the painted sheet S by heating and softening. A process is performed. Next, a stretching step (preliminary molding step) is performed in which the heat-softened painting sheet S is vacuum-suctioned through the vacuum suction passage and the conduit 19 and stretched along the cavity surface 13 of the female mold 12 (virtual in FIG. 6). line).

Subsequently, as shown in FIG.
A mold closing step of moving the female mold 12 to the male mold 40 side to close the mold is performed. Next, the female mold 12 and the female mold 40 are connected from the nozzle 43 of the injection molding machine through the runner 42 of the male mold 40. Injection molding is performed by injecting and filling the molten resin P into the cavity 13 between the molds, and thereafter, a mold opening step of separating the female mold 12 and the male mold 40 and an injection molded article to which the picture sheet S is adhered are formed into the female mold. A take-out step of taking out from the mold 12, a trimming step of separating a portion of the picture sheet S to be attached and attached to the injection-molded product from other portions (unnecessary portions) and the like are performed.

FIG. 8 shows another embodiment. In this case, the lifting chucks 54 are installed not on the lower end of the sheet S but on both sides of the sheet S. While holding both side edges of the sheet S, one shot of the sheet to be formed next is conveyed between the two dies, and the lower end of the sheet is fixed to the fixed chuck 55 in the downstream part of the female mold. Thereafter, the lifting chucks 54 on both sides of the sheet are released, and the lifting chucks 54 are retracted upstream between the two dies. With this configuration, there is no lifting chuck at the lower end of the sheet,
With the free end, the lower end of the sheet is delivered to the fixed chuck. Therefore, the lower end of the seat can be fixed more smoothly.

The lifting chucks 54 on both sides are connected to a lifting mechanism (not shown) such as a ram of a fluid pressure cylinder to drive the lifting and lowering. The lifting chuck 54 is operated by an electromagnet or the like so that the gripping piece 54b at the tip of the chuck rotates around the hinge 54a to grip or release the sheet. In FIG. 8, two pairs of the lifting chucks 54 are provided at the top and bottom, but of course, only one pair may be provided at the lower end position of the sheet.

[0068]

As will be understood from the above description, according to the method and apparatus for simultaneous painting by injection molding according to the present invention, a driving means for moving the cutting means is not separately required, and a relatively simple structure is provided. Originally, it is possible to cut one shot on the leading edge side of the strip-shaped painted sheet to the required minimum length without causing displacement, wrinkles, and wrinkles. It can be quickly withdrawn without any problems. Further, there is an excellent effect that the apparatus cost, the running cost, the occupied space and the like can be reduced as much as possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a female mold and its peripheral portion of an embodiment of a simultaneous painting apparatus for injection molding according to the present invention.

FIG. 2 is an enlarged perspective view showing the periphery of a female cavity of the simultaneous injection molding and painting apparatus of FIG. 1;

FIG. 3 is an enlarged view showing the vicinity of a heating wire of the simultaneous painting apparatus for injection molding of FIG. 1;

FIG. 4 is a circuit diagram for energizing heating wires provided in the simultaneous injection molding painting apparatus of FIG. 1;

FIG. 5 is an enlarged view for explaining a clamping step and a sheet separating step by the simultaneous injection molding painting apparatus according to the present invention.

FIG. 6 is a diagram for explaining a sheet softening step and a sheet stretching step by the simultaneous injection molding and painting apparatus according to the present invention.

FIG. 7 is a view provided for explaining a mold closing step and an injection molding step by the simultaneous injection molding painting apparatus according to the present invention.

FIG. 8 is an enlarged perspective view showing the periphery of a female cavity of another embodiment of the simultaneous injection molding and painting apparatus according to the present invention.

[Explanation of symbols]

 S Painting sheet 10 Injection molding simultaneous painting apparatus 12 Female mold 13 Cavity 17 Vacuum suction passage 25 Clamp 30 Heating wire 36 Escape groove 40 Male mold 60 Hot plate

Claims (6)

[Claims] 1. A band-shaped painted sheet is melt-cut in a width direction by a frame-shaped clamper for pressing and fixing the painted sheet which is movable in a direction perpendicular to a female parting surface used for injection molding. Injection molding simultaneous painting equipment with heating filaments. 2. A female type and a male type, which are arranged to face each other and one of which is moved to the other side, and one shot of the front side of a strip-shaped painting sheet wound up in a roll shape is used as the female type. A sheet supply means for supplying the parting surface of the mold, and a sheet supplying means for moving the shot part in a direction orthogonal to the parting surface of the female mold, wherein one shot of the leading end side of the painted sheet is separated from the parting surface of the female mold. And a resin injection means for injecting and filling a resin in a flowing state from the male mold side into the female mold cavity, and fixing the band-shaped painted sheet to the clamper. An injection molding simultaneous painting apparatus, characterized in that a heating wire is provided for melting and cutting in one direction and separating one shot of the tip side from a supply side. 3. The heating wire is stretched at a position protruding from the sheet pressing surface of the clamper toward the female mold, and the melted cutting of the painting sheet by the heating wire is performed by the clamping by the clamper. 2. The apparatus according to claim 1, wherein the operation is performed in cooperation with the pressing and fixing operation of the sheet.
Or the injection molding simultaneous painting apparatus according to 2. 4. An escape groove capable of accommodating the heating wire is provided in the female mold in order to avoid interference between the female mold and the heating wire when the clamped sheet is pressed and fixed by the clamper. 4. The simultaneous injection molding and painting apparatus according to claim 3, wherein: 5. The heating wire is made of an electric heating wire such as a nichrome wire, and the heating wire is attached to an end of the frame-shaped clamper on a sheet supply side via an insulating member. After the pressing and fixing operation starts, the heating wire is energized for a predetermined time, and the heating wire in contact with the painting sheet is heated to a temperature equal to or higher than the melting temperature of the painting sheet, so that the painting sheet is melt-cut. The simultaneous injection molding and painting apparatus according to any one of claims 1 to 4, characterized in that: 6. A sheet supply step of supplying one shot of the leading end side of a strip-shaped painted sheet wound up in a roll shape onto the female parting surface, and supplying the painted sheet to the female parting surface. A clamping step of pressing and fixing with a frame-shaped clamper above, a stretching step of stretching the painted sheet along the cavity surface of the female mold, and a mold by moving one of the female mold and the male mold to the other side. A mold clamping step of clamping and forming a cavity between both molds, an injection molding step of injecting and filling a resin in a flow state from the male mold side into the cavity, and performing an injection molding, and the female mold and the male mold A mold opening step of separating the molded sheet from the female mold, and a step of taking out the injection molded product to which the painted sheet is adhered from the female mold.
Or in an injection molding simultaneous painting method in which a plurality of steps are performed simultaneously or in parallel, in cooperation with the pressing and fixing operation of the painting sheet by the clamper, by a heating wire provided on the clamper And simultaneously cutting the strip-shaped painting sheet in the width direction to cut off the one shot on the front end side from the supply side.