JPH07125001A - Manufacture of continuous resin molded piece - Google Patents

Abstract

PURPOSE:To provide a method of two-color molding which does not cause flashes on the decorative face of the molded product. CONSTITUTION:A cavity 28 of clamped upper and lower molds 26 and 27 is filled with a hard material by a predetermined injection pressure. After the hard material is hardened, a moving core 29 is lowered to a protector forming position. When the moving core 29 reaches till the protector forming position, an upper end of a runner 35 of the lower mold 27 is opened and an opening at an upper part of a submarine gate 34 comes to face a runner 31, so that a cavity 37 is formed at the upper part of the moving core. The cavity 37 is filled with a soft material through the runners 31, 32, the submarine gate 34, and the runner 35 from the rear face side opposite to a decorative face with respect to a main body 21. As the soft material 38 gradually moves from a part from the end face of the main body 21 to the end face side of the main body 21 in the cavity 37, injection pressure is not exerted on the end face of the main body 21 from the beginning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a long resin molded product mounted on a vehicle or the like.

[0002]

2. Description of the Related Art Conventionally, there is known a vehicle 1 in which an overfender 3 is attached to an outer surface of a fender panel 2 as shown in FIGS. The over fender 3 is fixed by inserting a clip 5 into a mounting projection 4 on the inner surface of the over fender 3 and further inserting the clip 5 into the fender panel 2 and locking it. A protector 6 made of synthetic resin or the like is adhered to the peripheral edge of the end surface of the over fender 3 that abuts the fender panel 2 with a double-sided tape 7 or the like so that the design surface of the fender panel 2 is not scratched and the fender panel 2 is protected. No gap is formed between the two.

[0003]

This conventional technique has a problem that the number of assembling steps and the number of parts are increased because the step of attaching the protector 6 to the overfender 3 is required. Therefore, it is conceivable to replace the method of mounting the over fender 3 with a protector, which is a separate member, to form the over fender and the protector in two colors and integrally form them. In this structure, the protector is integrally formed on one end surface of the over fender with a soft material.

When adopting this structure, the two-color molding method is performed as follows. As shown in FIG. 10, a cavity 10 for forming an overfender is formed between the upper and lower molds 8 and 9, and one end surface side of the cavity 10 (a portion which becomes an end surface that contacts the fender panel 3 of the overfender after molding). ), The movable core 11 is provided so as to be vertically movable. First, the upper end of the moving core 11 shown in FIG. 10 is positioned at the position a, and the cavity 10 is injected and filled with a hard material for molding the over fender body, and after hardening, the moving core 11 is moved.
Is lowered to the b position to form the cavity 12 for the protector. Then, with respect to this cavity 12, a gate 13 is disposed near the end of the cavity 10 for the over fender and provided on the side of the cavity 12.
A soft material is injected through the resin to cure it.

However, in the case of the manufacturing method as described above, the injection pressure of the soft material from the gate 13 causes a space between the design surface, which is the outer surface of the overfender body, and the mold (the portion c shown in FIG. 10). After the soft material penetrates and the soft material is hardened, burrs are formed on the design surface of the over fender, and the appearance of the over fender deteriorates.

The above problems are common to other long resin molded products. An object of the present invention is to solve the above-mentioned problems, and when manufacturing a two-color protector together with an overfender, burrs do not occur on the design surface side of the overfender. To provide a method.

[0007]

According to the present invention, there is provided a main body formed of a hard material in a longitudinal direction and a main body attachment portion made of a soft material formed in a longitudinal direction with respect to a side portion of the main body. In a method for producing a two-color molded long resin molded product, a cavity for forming a main body is formed between a moving mold and a fixed mold, and a hard material is filled into the cavity and cured to form a main body. After that, the moving core provided in the mold on the back side of the main body is moved to form a cavity for forming the main body attachment part having a width of 15 mm or more on the back side of the main body, and the cavity for forming the main body attachment part is formed. In the cavity for forming the main body appendage, the main body is injected and filled with a soft material from a plurality of gates that are spaced from each other by a predetermined distance from the end side opposite to the tip side end in the side width direction of the main body, and then the main body is cured. It is necessary to mold the accessory part. It is the gist.

[0008]

With the above structure, the soft material to be filled moves from a position farther from the tip end in the lateral width direction of the body to the tip end in the lateral width direction of the body in the cavity for forming the body appendage. To do. Therefore, the injection pressure is prevented from being applied to the tip end portion in the lateral width direction of the main body from the beginning, and the tip end edge portion in the lateral width direction of the main body does not move to the design surface side.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a method for manufacturing an over fender will be described below with reference to FIGS.

First, the over fender 20 which is a long resin molded product will be described. As shown in FIGS. 6 and 7, the over fender 20 includes a main body 21 formed of a hard material such as polypropylene, and a PPE (thermoplastic elastomer) or the like on the end surface and the rear surface side of the main body 21 that abut the fender panel 23 of the vehicle. And a protector portion 22 made of a soft material. Body 21 of this over fender 20
The width d of the protector portion 22 that covers a part of the end surface and the back surface is 15 mm. The over fender 20 is fixed to the fender panel 23 by inserting a clip 25 into a mounting projection 24 provided on the inner surface of the over fender 20 and further inserting the clip 25 into the fender panel 23 and locking the clip 25. ing. And over fender 2
In the case of 0, one end surface of the fender panel 23 is abutted through the protector portion 22 made of a soft material so that the design surface of the fender panel 23 is not damaged.

Overfender 2 constructed as described above
A mold for manufacturing 0 will be described. As shown in FIG. 1, a movable mold upper mold 26 and a fixed mold lower mold 27.
A cavity 28 for forming the over fender body is formed therebetween. A movable core 29 is provided in the lower mold 27 so as to be vertically movable on one end surface side of the cavity 28 (a portion that becomes an end surface that contacts the fender panel 23 of the over fender after molding). The moving core 29 is shown in FIG.
It is movable between the main body forming position shown in FIG. 3 and the protector portion forming position located below the main body forming position as shown in FIG. The moving core 29 is formed so as to follow the shape on the one end face side of the cavity 28 for forming the main body. As shown in FIG. 1, the upper end surface of the moving core 29 is formed of a surface forming one end surface of the body 22 of the overfender 20 after molding and a surface forming a part of the back surface side of the body 22. In this embodiment, the length of the upper end surface of the moving core 29, that is, the length d of the portion involved in forming the width of the protector portion formed after the two-color formation is 15 mm.
It is said that. It is preferable that the length of d is 15 mm or more, and if it is less than 15 mm, the effect of the present invention cannot be sufficiently obtained.

A plurality of runners 31 are formed outside the sliding hole 30 in which the moving core 29 of the lower die 27 moves. The runner 31 communicates with an opening 32 a of a runner 32 provided in the upper mold 26. This upper die 27
As shown in FIG. 3, the opening 32a of the runner 32 is located at a predetermined position in the recess 33 that forms the cavity 28 for forming the main body, including the vicinity of the corner and the vicinity of the end.
In addition, they are arranged at a predetermined interval (200 mm interval in this embodiment). The cavity 28 is connected to a gate and runner (not shown). In addition, it is preferable that the predetermined interval is within a range of 200 mm to 400 mm.

One end of the runner 31 of the lower die 27 extends obliquely downward toward the sliding hole 30 of the moving core 29 and is opened in the sliding hole 30. Corresponding to each runner 31, the moving core 29 has a plurality of submarine gates 34 from the outer side surface (left side surface in FIGS. 1 and 3) of the moving core 29 toward the inner side surface (right side surface in FIGS. 1 and 3). One (only one is shown in FIGS. 1 and 2) is obliquely provided downward. One opening facing the runner 31 in the submarine gate 34 corresponds completely so that the opening cross-sectional area thereof is 100% effective when the moving core 29 is located at the protector portion forming position.

A runner 35 extending vertically is formed in a sliding hole 30 of the moving core 29 so as to correspond to the other opening of each submarine gate 34 of the moving core 29 at all times.
When 9 is located at the main body forming position shown in FIG. 1, its upper end is closed by the moving core 29.

Further, an extrusion pin 36 is provided so as to be vertically movable with respect to the lower mold 27. The push pin 36 is arranged with respect to the lower mold 27 so as to press both ends and corners of the molded over fender 20. In addition,
In FIG. 5, the positions where the extrusion pins 36 are arranged are indicated by P1 to P4 as positions facing each other in the recess 33 of the upper mold 26. The diameter of the upper end of the push pin 36 is reduced,
At the time of molding the main body, the hard material is also filled in the gap formed between the reduced diameter portion 36a and the lower die 27.

The manufacture of an over fender using the mold configured as described above will be described. The upper and lower molds 26 and 27 are clamped while the movable core 29 and the push pin 36 are positioned at the main body forming position in FIG. In this state, a hard material such as polypropylene is filled into the cavity 28 at a predetermined injection pressure through a runner and a gate (not shown) (see FIG. 2). After the hard material is hardened, the moving core 29 is lowered to the protector portion forming position shown in FIG. Moving core 2
When 9 is lowered to the protector portion forming position, the lower mold 2
The upper end of the runner 35 of No. 7 is opened, and the upper opening of the submarine gate 34 faces the runner 31.
Further, when the movable core 29 is moved to the protector forming position, the movable core 29 and the lower mold 2 are located above the movable core 29.
7. A cavity 37 for forming a protector portion surrounded by the main body 21 is formed.

A soft material 38 is injected into the cavity 37 through a runner 32 of the upper mold 26, a runner 31 on the lower mold 27 side, a submarine gate 34, and a runner 35 at a predetermined injection pressure to fill the cavity 37. . That is, the soft material 38 is filled into the cavity 37 from the back surface side of the main body 21, which is opposite to the design surface. Since the soft material 38 to be filled gradually moves to the end surface side of the main body 21 from a position farther from the end surface of the main body 21 in the cavity 37, the injection pressure is not applied to the end surface of the main body 21 from the beginning. Therefore, the filled soft material 38 does not reach the end surface of the main body 21 and further move from the end surface to the design surface side.

After that, the filled soft material is cured, so that the protector portion 22 is formed on a part of the end surface and the back surface of the main body 21 of the over fender 20. Then, after opening the upper and lower molds 26, 27, the extrusion pin 3
6 is moved upward and the overfender 20 is taken out.

In the above manufacturing process, in this embodiment, the soft material 38 to be filled is filled with the main body 2 in the cavity 37.
It gradually moves to the end face side of the main body 21 from a position far from the end face of 1. Therefore, since the injection pressure is prevented from being applied to the end surface of the main body 21 from the beginning, the filled soft material 38 does not reach the end surface of the main body 21 and further move from the end surface to the design surface side. As a result, burrs do not occur on the design surface side of the main body 21.

Even if a burr is generated between the lower die 27 and the back surface of the main body 21 near the upper opening of the runner 35 due to the injection pressure, unlike the design surface of the main body 21, the fender panel 2 of the vehicle is overfendered. If 20 is attached, the burr is not visible, so there is no problem in design.

Further, in this embodiment, the length of the upper end surface of the movable core 29, that is, the length d of the portion related to the formation of the width of the protector portion formed after the two-color formation is set to 15 mm,
It is arranged so as to face the back surface side of the main body 21. Therefore, the width of the cavity 37 for forming the protector portion is 15 mm from the end surface including the end surface and the back surface side of the main body 22. Therefore, as compared with the case where the movable core 11 is provided only on the end surface of the main body 21 as shown in FIG. 10, the flow passage cross-sectional area can be increased, and the internal pressure at the time of injection can be reduced. It is possible to prevent the occurrence of burrs on the design surface side.

Furthermore, since the moving core 29 is thicker than the moving core of FIG. 10, the durability of the moving core 29 can be improved. Next, a second embodiment will be described. The same or corresponding components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, in the construction of the above-mentioned embodiment, an extending portion 40 is formed by bending an end portion of the main body 21 on the side abutting the fender panel 23, along the fender panel 23. The protector portion 22 made of a soft material is differently formed on the back surface of 40 in two colors.
The extension portion 40 has a length d of 15 mm or more.

Therefore, as shown in FIG. 11, both upper and lower molds 2
The portions corresponding to the extended portions of 6 and 27 are also changed correspondingly, and the over fender 20 is formed by the same injection molding as in the first embodiment by the molds 26 and 27.

The present invention is not limited to the above embodiments, but may be embodied in other long resin molded products such as side garnishes and side moldings.

[0026]

As described in detail above, the present invention has an excellent effect that burrs do not occur on the design surface side of the main body when the main body attachment part and the main body are two-color molded.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts of a mold forming an over fender according to an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of a mold in which a hard material forming the body of the over fender is filled.

FIG. 3 is a sectional view of an essential part of the mold in a state where the moving core is also moved.

FIG. 4 is a sectional view of an essential part of a mold similarly filled with a soft material.

FIG. 5 is a bottom view of the upper mold of the same.

FIG. 6 is a perspective view of the over fender.

FIG. 7 is a sectional view showing a state in which the over fender is also attached to the fender panel.

FIG. 8 is a schematic perspective view of a vehicle to which an over fender is attached.

FIG. 9 is a cross-sectional view of a conventional overfender attached to a fender panel.

FIG. 10 is an explanatory diagram of a case where the over fender is two-color molded.

FIG. 11 is an explanatory diagram of two-color molding of the over fender of the second embodiment.

[Explanation of symbols]

20 ... Over fender, 21 ... Main body, 22 ... Protector part (main body attachment part), 23 ... Fender panel, 26 ... Upper mold, 27 ... Lower mold, 28 ... Cavity, 29 ... Moving core, 30 ... Sliding hole , 31 ... Runner, 34 ... Submarine gate, 36 ... Extrusion pin.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location // B29L 31:30 (72) Inventor Kouji Nakao 1 Ochiai, Nagahata, Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi prefecture Toyoda Gosei Co., Ltd. (72) Inventor Akira Yamauchi No. 1 Nagahata, Ochiai, Okaai, Kasuga-cho, Nishikasugai-gun, Aichi Toyoda Gosei Co., Ltd.

Claims (1)

[Claims] 1. A long resin in which a main body formed of a hard material in a longitudinal direction and a main body attachment portion made of a soft material formed along a longitudinal direction with respect to a side portion of the main body are two-color molded. In the method of manufacturing a molded article, a cavity for forming a main body is formed between a moving mold and a fixed mold, and a hard material is filled into the cavity and cured to form a main body. The movable core provided in the mold is moved to form a cavity for forming a main body attachment part having a width of 15 mm or more on the back side of the main body. In the cavity, a soft material is injection-filled from a plurality of gates that are spaced from each other from the end side opposite to the tip side end in the lateral width direction of the main body, and the main body appendage is molded by curing. Characteristic long resin molded product Manufacturing method.