JPS63154315A - Molding method of synthetic resin product with skin material - Google Patents

Abstract

PURPOSE:To enable molding easily and swiftly without necessitating secondary processing on treatment of a terminal part of a skin material, by a method wherein mold break of a pair of molding tools is performed at a predetermined space under a state where synthetic resin to which a skin material has been stuck is not solidified compolelely, a warm air is sent to the inside of a cavity, the terminal part of the skin material left behind on the circumference of the synthetic resin is folded back to the backside of a part of a formed article, and mold clamping is performed again for molding. CONSTITUTION:The inside of a cavity 3 is filled with molten resin composed of thermoplastic synthetic resin by injection through a casting hole 9. In this instance, a skin material 51 is stretched by running after a forming surface 5 of the cavity of a molding tool 2 and adheres to the surface of the synthetic resin. Then the molding tool 2 on a movable side is moved backward by a predetermined distance under a state where the synthetic resin to which the skin material has been stuck is not solidified completely and the molding tool is broken by a predetermined space where fitting parts 6, 7 still keep fitting. Then after fixed decompression has been performed within the cavity 3, air which has been kept warmed by a heater 33 is sent into the cavity 3 through an air ventilation path 36 at a breath. A terminal part 51a of the skin material 51 left behind on a circumferential surface of the synthetic resin is folded back extending over the whole circumference and rolled in the backside of a molded product 61. In this moment, the synthetic resin of the molded product 61 is pressed against the skin material 51 by moving forward again the molding tool 2 on the movable side and made into a completely stuck state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for molding a synthetic resin product with a skin body used as, for example, an interior material for an automobile.

(Prior Art) Conventionally, when molding a synthetic resin molded product having a skin integrally provided on its surface, a pair of opposing molds are used, for example, as shown in Japanese Patent Application Laid-Open No. 6O-2J9021. A skin body is disposed on the cavity forming surface of one of the molds to clamp the pair of molds, and a thermoplastic synthetic resin is injected into the cavity formed by the pair of molds to form the molded product. The skin is attached to the surface, and at the same time, unnecessary portions of the skin around the molded product are cut off using a cutting blade provided on the mold.

(Problems to be Solved by the Invention) According to the above-mentioned conventional molding method, in the end treatment of the skin body, unnecessary portions of the skin body are simply cut off at the same time as molding. A secondary process is required in which the molded body is folded back to the back side and bonded with adhesive. As a result, it takes time to process the ends of the skin, the folds cannot be folded neatly, and peeling tends to occur, and if the skin is cloth-like, the threads on the cut surface may become frayed, resulting in poor finishing. It can get worse.

The present invention is an attempt to solve the above-mentioned problems, and involves folding back the ends of the skin at the same time as molding, eliminating the need for secondary processing to process the ends of the skin, and facilitating molding. The purpose is to make it possible to do so quickly.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a skin body on the cavity forming surface of one mold in a pair of opposing molds, clamps the pair of molds, and A thermoplastic synthetic resin is injected into the cavity formed by the mold, and the skin body is attached to the surface of the synthetic resin in the shape of a molded product. The molds are opened at a predetermined distance, the pressure inside the cavities of the pair of molds is reduced, and warm air is blown into the cavities to remove the end portion of the skin body left around the synthetic resin in the shape of the molded product. is folded back to the back side of the molded product, and the pair of molds are clamped again to form a laminate molded product.

(Function) The present invention involves clamping a pair of molds with a skin body disposed on the cavity forming surface of one of the molds, and injecting a thermoplastic synthetic resin into the cavity formed by the pair of molds. , a skin body is attached to the surface of the synthetic resin. Then, the pair of molds are opened at a predetermined interval before the synthetic resin to which the skin is attached is completely solidified. At the same time, the inside of the cavity is depressurized, and after a predetermined period of time after starting the depressurization in the cavity, or at the same time as the depressurization in the cavity, lff1 is blown into the cavity, and by this blowing pressure, the shape of the molded product is synthesized. The end portion of the skin body left around the resin is folded back, and when it is wrapped around the back side of the molded product, the pair of molds is clamped again, so that the end portion of the skin body becomes the molded product. A laminated molded product is obtained which is bonded to the back side of the laminate.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In Fig. 1, reference numeral 1.2 denotes a pair of molds on a fixed side and a movable side that face each other, and the pair of molds 1.2 has an uneven cavity forming a cavity 3 in the center of the opposing surface. A fitting portion 6, which is provided with a surface 4.5 and is slidably fitted to the outer periphery of the opposing surface by a predetermined length,
7 is provided. Further, a slide mold 8 that forms a part of the cavity 3 is provided on the concave cavity forming surface 5 of the movable mold 2 so as to be able to move forward and backward. Further, an injection hole 9 is formed in the center of the mold 1 on the fixed side, and a nozzle joint 10 is provided at the outer end of the injection hole 9.

A pressure reducing device 11 is provided in the mold 1 on the fixed side. This pressure reducing device 11 has a piston 13 inside a cylinder 12.
A vacuum bottle 15 that appears and retracts into the cavity 3 is attached to the tip of a rod 14 that protrudes from the piston 13.
A vacuum hole 16 is opened at the tip of the vacuum bottle 15, and the vacuum hole 16 is connected to a vacuum pump 18 via a suction path 17.The tip of the vacuum bottle 15 is made flush with the cavity forming surface 4 by a spring 19. It is constantly biased in the direction of sinking into the mold 1. Further, the inner and outer ends of the cylinder 12 are connected to an oil tank 25 by a conduit 20.21 via an electromagnetic switching valve 22, a pump 23, and an oil filter 24.

A plurality of hot air blowers 131 are provided in the fitting portion 7 of the mold 2 on the movable side. This hot air blower 31 is
A heater 33 is provided inside the blower case 32, a pump 34 is connected to the blower case 32, and a blower path 36 opening inside the fitting portion 7 is connected to the blower case 32 via a valve 35. has been done.

A drive device 4 for the slide mold 8 is attached to the mold 2 on the movable side.
1 is provided. In this driving device 41, a piston 43 is fitted into a cylinder 42 so as to be freely movable back and forth, and a rod 44 connected to the slide mold 8 is protruded from the piston 43. Further, the inner and outer ends of the cylinder 42 are connected to T11! by pipes 45 and 46. Switching valve 47, pump 48
and the oil tank 2 via the oil filter 49.
5.

Then, for molding, first, as shown in FIG. A skin body 51 such as a cloth having a raised surface is disposed on the molding surface 4 .

In this case, for example, the skin body 51 is hung with its front side facing the movable mold 2 side and its upper end fixed to the mold 1 with double-sided tape or the like. In this state, the vacuum bag m1ll, the hot air blower 31, and the drive device 41 of the slide mold 8 are in a stopped state.

Next, as shown in FIG. 3, the movable mold 2 is advanced toward the fixed mold 1, and the fitting part 6 of the mold 1.2 is moved forward.
7 are fitted, and the unnecessary portion 52 on the entire circumference of the skin body 51 is sheared and removed using the edge portions 6a and 7a.

Next, when the movable mold 2 moves further forward and is clamped with the fixed mold 1 as shown in FIG. 4, the skin body 5
1 is completely separated, and the end portion 51a of the entire circumference of the skin body 51 is held between the molds 1.2 on the outer periphery of the cavity 3.

Next, as shown in FIG. 5, the nozzle 56 of the injection unit 55 moves forward and joins the nozzle joint 10 in the injection hole 9 of the mold 1, and the molten resin made of thermoplastic synthetic resin is discharged from the injection hole 9. The cavity 3 is injected and filled. At this time, the skin body 51 is the cavity forming surface 5 of the mold 2,
That is, it is stretched along the surface shape of the molded article and is attached to the surface of the synthetic resin shaped like the molded article.

Next, the cavity 3 is filled with molten resin, and the skin body 5 is filled.
When the synthetic resin to which 1 is attached is not completely solidified, that is, immediately after filling with molten resin or 1 to 2 seconds after filling,
As shown in FIG. 6, the mold 2 on the movable side is moved back by a predetermined distance, and the fitting part 6 between the mold 2 on the fixed side and the mold 1 on the fixed side is moved back.
．． 7 is still open by a predetermined distance while still being fitted. At this time, the molded product 61 is attached to the movable mold 2 having no draft angle.

Simultaneously with this mold opening, the electromagnetic switching valve 22 of the pressure reducing device 11 operates in one direction to form a hydraulic circuit, and the pump 2
3 is activated, hydraulic pressure is applied to the rear side of the piston 13 of the cylinder 12 via the conduit 20, and the hydraulic pressure on the front side of the piston 13 is drained to the oil tank 25 via the conduit 21. Then, the piston 13 is moved forward by hydraulic pressure, and the vacuum bottle 15 is moved forward together with the rod 14. At the moment when the vacuum hole 16 at the tip protrudes into the cavity 3, the vacuum pump 18 is activated, and the vacuum bottle 15 is moved forward through the suction path 17. Begin depressurizing the inside. At this time, molds 1 and 2
are in contact at the fitting parts 6 and 7 around the entire circumference, and the injection unit 5
The nozzle 56 of No. 5 is in contact with the nozzle joint 10 of the mold 1, and the valve 35 of the hot air blower 31 is also closed, so the pressure inside the cavity 3 is quickly reduced.

Then, after a predetermined period of time has elapsed since the start of depressurization in the cavity 3 and a constant depressurization has been performed, each hot air blower device 3
1 valve 35 opens, and the pump 34 is inserted into the ventilation case 32.
The air that has been supplied by the heater 33 and warmed in advance by the heater 33 is blown into the cavity 3 from the air passage 36 at once. Due to this blowing pressure, the end portion 51a of the skin body 51 left on the peripheral surface of the synthetic resin in the shape of the molded product is folded back around the entire circumference and rolled up onto the back side of the molded product 61. At this moment, the mold 2 on the movable side moves forward again and starts the mold clamping operation, and at the same time the mold clamping operation is signaled, the pressure reducing device 11
The electromagnetic switching valve 22 operates in reverse, and the piston 13 retreats, and is also pushed back by the elastic force of the spring 19, and the vacuum bottle 15 also moves back, so that its tip becomes flush with the cavity 3, and the electromagnetic switching valve 22 becomes neutral. Upon returning to the position, the pump 23 is stopped, the vacuum pump 18 is also stopped, and the valve 35 of the hot air blower 31 is also closed. Then, the state shown in FIG. 7 is reached, and the end portion 51a of the skin body 51 is bonded to the back side of the molded product 61. The state shown in FIG. 7 is maintained for a predetermined cooling period. At this time, molded product 6
Since the synthetic resin No. 1 is not completely solidified, the synthetic resin of the molded product 61 is pressed against the skin body 51 by mold clamping, and an anchor effect occurs, resulting in a complete adhesion state.

Next, as shown in FIG. 8, after the mold 2 on the movable side is moved back and opened, the electromagnetic switching valve 47 of the drive device 41 of the slide mold 8 operates in one direction to form a hydraulic circuit. The pump 48 operates, and hydraulic pressure is applied to the rear side of the piston 43 of the cylinder 42 via the pipe line 45, and the hydraulic pressure on the front side of the piston 43 is applied to the oil tank 25 via the pipe line 46.
is drained. Then, the piston 43 is moved forward by hydraulic pressure, and together with the rod 44, the slide die 8 is moved forward, and the molded product 61 is ejected. At this time, since the molded product 61 is pushed out by the entire surface of the slide die 8, no partial ejection marks remain, and the skin body 51 is held in a good condition, as shown in FIGS. 9 and 10. As shown, a molded product 61 is obtained in which the end portion 51a of the skin body 51 is adhered to the back side.

After the ejection of the molded product 61 is completed, the electromagnetic switching valve 47 is operated in reverse, and the slide die 8 is moved back, making it ready for the next molding.

In the above process, when folding back the end portion 5ta of the skin body 51, the pressure inside the cavity 3 may be reduced and at the same time hot air may be blown to wrap up the end portion 51a of the skin body 51. In addition, in this molding, the injection unit 55
As the nozzle 56, a shut-off nozzle or a hydraulic needle valve nozzle may be used since drooling can be prevented.

Next, the embodiment shown in FIGS. 11 and 12 is an embodiment in which an epidermis supply device 71 is added to the embodiment described above. This skin supply 5A@71 is supplied to drums 74.75 via support arms 72.73 to the upper and lower parts of the mold 1 on the fixed side.
is mounted on a shaft, and a skin body 51 is wound around and supported on this upper drum, and the lower end of this skin body 51 is connected to a lower drum 7.
Connect to 5. Further, a motor 76 is connected to the lower drum 75 via a gear interlocking mechanism 77. As shown in FIG. 11, before forming, the lower drum 75 for winding is rotated by the motor 76 via the gear interlocking mechanism 77, and the skin body 51 is transferred to the upper drum 74.
The skin body 51 is stretched over the mold surface of the mold 1 by drawing it out from the mold 1. At this time, by using the upper drum 74 having a certain degree of rotational torque, the skin body 51 of a predetermined length can be set without sagging excessively even when the skin body 51 is pulled down.

Then, molding is performed in the same manner as described above, but the skin body 51
is continuous vertically, so the epidermis 5 left in a frame shape
The unnecessary portions 52 of 1 are also left vertically. Therefore, after molding, as shown in FIG. 12, the lower drum 75
By rotating the drum 75 to feed the skin body 51 and winding up the unnecessary portion 52 remaining after punching on the drum 75, it can be prepared for the next molding.

〔Effect of the invention〕

According to the present invention, the end portion of the skin body can be folded back at the same time as the molding, and the end portion of the skin body does not require secondary processing, and the molding can be performed easily and quickly.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the apparatus used in the molding method of the present invention, Figure 2
8 to 8 are sectional views showing the molding process, FIG. 9 is a perspective view of the molded product, FIG. 10 is a sectional view thereof, and FIGS. 11 and 12 are sectional views showing other embodiments. be. 1.2... Molding mold, 3... Cavity, 4... Gavity forming surface, 51... Skin body, 51a... Terminal part, 61
··Molding. 5ggJ

Claims (3)

[Claims] (1) A skin body is disposed on the cavity forming surface of one of the molds in a pair of opposing molds, the pair of molds are clamped, and a thermoplastic compound is formed in the cavity formed by the pair of molds. The skin is attached to the surface of the synthetic resin in the shape of a molded product by injecting resin, and the pair of molds is opened at a predetermined interval while the synthetic resin to which the skin is attached is not completely solidified. While reducing the pressure inside the cavity of the mold, warm air is blown into the cavity to fold the end portion of the skin body left around the synthetic resin in the shape of the molded product to the back side of the molded product, A method for molding a synthetic resin product with a skin body, comprising clamping the above-mentioned pair of molds again to mold a laminate molded product. (2) When folding back the end portion of the skin body, the pair of molds are opened at a predetermined interval to reduce the pressure inside the cavity, and then warm air is blown into the cavity. Method for molding the described synthetic resin product with a skin body. (3) At the time of folding back the end portion of the skin body, a pair of molds are opened at a predetermined interval to reduce the pressure inside the cavity, and at the same time,
A method for molding a synthetic resin product with a skin body according to claim 1, characterized in that hot air is blown into the cavity.