JP3008750B2 - Manufacturing method of long resin molded products - Google Patents

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 to be mounted on a vehicle or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 8 and 9, for example, a vehicle in which an over fender 3 is attached to an outer surface of a fender panel 2 of a vehicle 1 is known. The over fender 3 is fixed by inserting a clip 5 into a mounting projection 4 on the inner surface thereof, and further inserting the clip 5 into the fender panel 2 and locking it. A protector 6 made of a synthetic resin or the like is adhered to a peripheral edge of the over fender 3 that comes into contact with 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 damaged and the fender panel 2 is not damaged. 2 is not formed.

[0003]

However, this prior art requires a process of attaching the protector 6 to the over fender 3, and thus has the problem of increasing the number of assembly steps and the number of parts. Therefore, instead of mounting the overfender 3 with a protector which is a separate member, the overfender and the protector may be integrally formed by two-color molding. This structure is a structure in which the protector is integrally formed of a soft material on one end surface of the over fender.

When this structure is employed, the two-color molding is performed, for example, as follows. As shown in FIG. 10, a cavity 1 for forming an over fender is provided between upper and lower molds 8 and 9.
0, and a movable core 11 is provided on one end surface side of the cavity 10 (a part to be an end surface which comes into contact with the fender panel 3 of the over fender after molding) 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 hard material for molding the over fender body is injected and filled into the cavity 10, and after hardening, the moving core 11 is lowered to the position b and the protector is lowered. Cavity 1 for
Form 2 And for this cavity 12,
A soft material is injected through a gate 13 provided on the side of the cavity 12 and is hardened while being arranged close to the end of the cavity 10 for over fender. The hardened soft material portion becomes the protector portion 14.

However, when the hard material filled in the cavity 12 for forming the over fender is hardened, both ends and corners of the over fender body 15 in the longitudinal direction contract as shown by arrows in FIG. The ends and corners in the direction may be displaced from the mold due to shrinkage. As a result, when the soft material is subsequently filled into the cavity 10 for forming the protector, the design surface side or the end surface of the over fender body 15 is shifted at a displaced portion of the over fender body 15, for example, at a portion near an end surface and a corner portion. There is a problem that the soft material penetrates into the side and the burrs 16 as shown in FIG. 12 are formed and the appearance is not good.

[0006] Such a problem is not limited to the over fender, and is a common problem in other long resin molded products formed by two colors. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem. When the main body and the main body attachment portion are formed in two colors along the longitudinal direction, the main body and the main body are displaced from the mold even if the main body shrinks. It is an object of the present invention to provide a method for producing a long resin molded product in which burr is prevented and burrs are not generated on the design surface side of the main body.

[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 made of a soft material formed along a longitudinal direction with respect to a side portion of the main body. In the method of manufacturing a long resin molded product to be molded in two colors, a mold on a back surface side which becomes a main body after molding, with respect to an effective position for preventing displacement in a cavity for forming a main body formed between a moving mold and a fixed mold. After protruding a pin so as to cut into the cavity, filling the cavity with a hard material and curing to form a main body, then moving a movable core provided in a mold on the back side of the main body, A cavity for forming a main body attachment portion is formed on the back side, and a soft material is injected and filled into the cavity for forming the main body attachment portion from a plurality of gates spaced at a predetermined distance from each other, and is cured to form a main body attachment portion. That is the gist There.

[0008]

With the above arrangement, the hard material filled in the cavity for forming the main body hardens and shrinks after filling, but the pin disposed in the effective position for preventing slippage cuts into the hard material, thereby causing the shrinkage of the main body. Is prevented.

[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 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 PPE (thermoplastic elastomer) or the like on the end surface and the back surface of the main body 21 that contact the fender panel 23 of the vehicle. And a protector portion 22 as a body attachment portion made of a soft material. The body 21 of the over fender 20
Has a width d of 15 mm. The over fender 20 is fixed to the fender panel 23 by inserting a clip 25 into a mounting projection 24 projecting from the inner surface of the over fender 20 and further inserting the clip 25 into the fender panel 23 for locking. ing. And over fender 2
No. 0 has one end face abutted on the fender panel 23 via the protector portion 22 made of a soft material so that the design surface of the fender panel 23 is not damaged.

The over fender 2 configured as described above
The mold for manufacturing the No. 0 will be described. As shown in FIG. 1, an upper mold 26 as a movable mold and a lower mold 27 as a fixed mold.
A cavity 28 for forming an over fender main body is formed therebetween. A movable core 29 is provided in the lower mold 27 on the one end surface side of the cavity 28 (a portion which becomes an end surface that comes into contact with the fender panel 23 of the over fender after molding) in a vertically movable manner. The moving core 29 is shown in FIG.
3 and a protector portion forming position located below the main body forming position as shown in FIG. The movable core 29 is formed so as to conform to the shape on one end surface side of the cavity 28 for forming the main body. As shown in FIG. 1, the upper end surface of the movable core 29 is formed of a surface forming one end surface of the main body 22 of the molded over fender 20 and a surface forming a part of the rear surface side of the main body 22. In this embodiment, the length d of the upper end surface of the movable core 29, that is, the length d of the portion involved in forming the width of the protector formed after the two colors is formed is 15 mm.
It has been. It is preferable that the length 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 the lower mold 27 where the movable core 29 moves. The runner 31 communicates with an opening 32 a of a runner 32 provided in the upper mold 26. This upper mold 27
As shown in FIG. 3, the opening 32a of the runner 32 is located at a predetermined position including the vicinity of the corner and the end of the recess 33 forming the cavity 28 for forming the main body.
In addition, they are arranged so as to have a predetermined interval (in this embodiment, an interval of 200 mm). The cavity 28 is connected to a gate and a runner (not shown). It is preferable that the predetermined interval is in the range of 200 mm to 400 mm.

One end of the runner 31 of the lower mold 27 extends obliquely downward toward the sliding hole 30 of the movable core 29 and is opened in the sliding hole 30. A plurality of submarine gates 34 are provided on the movable core 29 corresponding to the respective runners 31 from the outer side surface (the left side surface in FIGS. 1 and 3) to the inner side surface (the right side surface in FIGS. 1 and 3). 1 (only one is shown in FIG. 1 and FIG. 2). One opening facing the runner 31 in the submarine gate 34 completely corresponds so that the opening cross-sectional area is 100% effective when the movable core 29 is located at the protector portion forming position.

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

An extrusion pin 36 is provided so as to be vertically movable with respect to the lower mold 27. The push pins 36 are arranged on the lower mold 27 so as to press both ends and corners of the formed over fender 20. Both ends and corners of the over fender 20 are prevented from displacing the over fender body 21 from the mold when the hard material forming the over fender body 21 is filled in the cavity 28 and then hardened and contracted. It is a valid position. In FIG. 5, the positions of the push pins 36 are indicated by P1 to P4 as opposing positions in the concave portion 33 of the upper mold 26. The upper end of the extrusion pin 36 is formed to have a reduced diameter, so that the hard material bites into the cavity 28 so that the hard material is filled in the gap formed between the reduced diameter portion 36a and the lower mold 27 during the molding of the main body. Are located.

The manufacture of an over fender using the above-configured mold will be described. The upper and lower dies 26, 27 are clamped with the moving core 29 and the push pin 36 positioned at the main body forming position in FIG. In this state, the cavity 28 is filled with a hard material such as polypropylene at a predetermined injection pressure through a runner and a gate (not shown) (see FIG. 2). After the hard material has hardened, the movable core 29 is lowered to the protector portion forming position shown in FIG. Moving core 2
When the lower mold 9 is lowered to the protector portion forming position, the lower mold 2
The upper end of the submarine gate 34 faces the runner 31 while the upper end of the runner 35 is opened.
In addition, by moving the movable core 29 to the protector portion forming position, the movable core 29 and the lower mold 2 are provided above the movable core 29.
7. A cavity 37 for forming a protector portion is formed as a cavity for forming a main body attachment portion surrounded by the main body 21.

A soft material 38 is injected into the cavity 37 at a predetermined injection pressure via the runner 32 of the upper mold 26, the runner 31 on the side of the lower mold 27, the submarine gate 34, and the runner 35 for filling. . That is, the soft material 38 is filled into the cavity 37 from the back surface side opposite to the design surface with respect to the main body 21. Since the soft material 38 to be filled gradually moves to the end face side of the main body 21 from a position farther from the end face of the main body 21 in the cavity 37, the injection pressure is not applied to the end face of the main body 21 from the beginning. Therefore, the filled soft material 38 does not reach the end face of the main body 21 and further does not move from the end face to the design surface side. Thereafter, the filled soft material is hardened, so that the protector 22 is attached to the end face and a part of the back face of the main body 21 of the over fender 20.
Is formed.

Then, after the upper and lower dies 26 and 27 are opened, the extrusion pin 36 is moved upward to move the over fender 2.
Take out 0. In the above manufacturing process, when the hard material filled in the cavity 28 for forming the main body is hardened, shrinkage occurs in the direction of the arrow shown in FIG. 5, but in this embodiment, both ends and corners of the over fender 20 are formed. On the other hand, since the push-out pin 36 bites into the over fender body 2
1 is prevented from deviating from the mold. Therefore, generation of burrs on the design surface or the end side surface at both end portions and corner portions of the over fender 20 is prevented.

In this embodiment, the soft material 38 to be filled is used.
Gradually moves from the portion of the cavity 37 farther from the end face of the main body 21 to the end face side of the main body 21. Therefore, since the injection pressure is prevented from being applied to the end face of the main body 21 from the beginning, the filled soft material 38 does not reach the end face of the main body 21 and further shift from the end face to the design surface side. As a result, burrs do not occur on the design surface side of the main body 21.

Even if burrs are formed between the lower mold 27 and the back surface of the main body 21 due to the injection pressure near the upper end opening of the runner 35, unlike the design surface of the main body 21, the fender panel 2 of the vehicle has an over fender. Since the burr is not visible if 20 is attached, there is no problem in design.

In this embodiment, the length of the upper end surface of the movable core 29, that is, the length d of the portion involved in forming the width of the protector formed after the two colors is formed is 15 mm.
The main body 21 is opposed to the back side. For this reason, the width of the cavity 37 for forming the protector portion is 15 mm from the end face including the end face and the back face side of the main body 22. Therefore, as compared with the case where the moving core 11 is provided only on the end face of the main body 21 as shown in FIG. 10, the flow path cross-sectional area can be increased, and the internal pressure at the time of injection can be reduced. Can be prevented from being generated on the design surface side.

Furthermore, since the thickness of the moving core 29 is larger than that of the moving core of FIG. 10, the durability of the moving core 29 can be improved. The present invention is not limited to the above embodiment, and may be configured as follows. (1) In the above-described embodiment, the pressing pin is arranged at the shift prevention effective position. However, instead of the pressing pin, another pin may be arranged so as to bite into the cavity for forming the main body at the shift prevention effective position. (2) In the above-described embodiment, the shape of the upper end of the pressing pin is reduced in diameter. However, the shape is not limited to this as long as the pressing pin bites into the cavity 28. (3) In the above embodiment, the present invention is embodied as an over fender.
It may be embodied in another long resin molded product, for example, a side garnish, a side molding, or the like.

[0023]

As described above in detail, according to the present invention, when the main body is molded in two colors together with the main body attachment portion, the main body can be prevented from being displaced from the mold. Is produced on the design surface side of the main body.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a mold for forming an over fender according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of a mold in a state where a hard material constituting the body of the over fender is filled.

FIG. 3 is a sectional view of a main part of a mold in a state where a movable core is moved.

FIG. 4 is a sectional view of a main part of a mold in a state where a soft material is filled.

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

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

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

FIG. 8 is a schematic perspective view of a vehicle equipped with an over fender.

FIG. 9 is a cross-sectional view of a state in which a conventional over fender is attached to a fender panel.

FIG. 10 is an explanatory diagram in a case where an over fender is formed in two colors.

FIG. 11 is an explanatory diagram showing a direction in which the over fender contracts.

FIG. 12 is a perspective view showing a state in which burrs are generated on the over fender.

[Explanation of symbols]

Reference Signs List 20: Over fender, 21: Main body, 22: Protector (main body attached part), 23: Fender panel, 26: Upper die, 27: Lower die, 28: Cavity, 29: Moving core, 30: Sliding hole , 31 ... runner, 34 ... submarine gate, 36 ... extrusion pin.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-106624 (JP, A) JP-A-64-20109 (JP, A) JP-A-57-144737 (JP, A) 71418 (JP, U) JP-A 3-31927 (JP, U) JP-A 62-173913 (JP, U) JP-49-21746 (JP, B1) JP-B 45-10233 (JP, B1) Special Table 3-500991 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/00-45/84 B29C 33/00-33/76

Claims (1)

(57) [Claims] 1. A long resin for two-color molding of a main body formed of a hard material in a longitudinal direction and a main body attachment portion of a soft material formed along a longitudinal direction with respect to a side portion of the main body. In the method for manufacturing a molded product, a pin is formed so as to bite into the cavity from a mold on the back side which becomes a main body after molding, with respect to an effective position for preventing displacement in a cavity for forming a main body formed between a movable mold and a fixed mold. After filling the hard material into the cavity and curing it to form a main body, the moving core provided on the mold on the back side of the main body is moved to form a main body attachment portion on the back side of the main body. The cavity for forming the main body attachment portion is formed by injecting and filling a soft material from a plurality of gates spaced at a predetermined interval from each other into the cavity for forming the main body attachment portion, and curing and hardening the main body attachment portion. Method for manufacturing resin molded products .