JPH0745232B2 - Exterior resin product for automobile and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The invention according to claim 1 (hereinafter referred to as the first invention) relates to exterior resin products for automobiles such as spoilers and rear garnishes. (Hereinafter referred to as the second invention) relates to a method for producing the exterior resin product for automobiles.

[Prior Art] Conventionally, exterior resin products for automobiles such as spoilers and garnishes are usually made of a hard material, and if they are directly attached to the body of an automobile, the exterior resin product for automobiles will damage the painted surface of the body. Therefore, a soft protector was attached to the body contact portion of the exterior resin product for automobiles.

For example, in the case of a side spoiler, as shown in FIG. 6, a protector 24 is fixed to the side spoiler 23 with a double-sided tape or an adhesive at the contact portion of the side spoiler 23 against the body 22 below the door 21 of the automobile. There is.

[Problems to be Solved by the Invention] An automobile exterior resin product using the above-mentioned conventional protector 24 is protected from the automobile exterior resin product during transportation.
There was a problem that 24 was dislodged, the color tone between them did not match, and the appearance was poor due to the boundary line and step between them.

Further, in the method of manufacturing the exterior resin product for automobiles, it takes a work man-hour to adjust the protector 24 to the shape of the main body of the exterior resin product for automobiles, and further, it is necessary to form the protector 24 having a predetermined shape so as not to come off from the body. Since there is a cost, there is a problem that the manufacturing cost becomes high.

Therefore, an object of the first invention is to solve the above-mentioned problems and to have a simple appearance that does not require a protector.
An object of the present invention is to provide an exterior resin product for automobiles in which the painted portion of the body contact portion is not damaged.

A second object of the present invention is to provide a method for manufacturing an exterior resin product for an automobile, which reduces the manufacturing man-hour and the manufacturing cost.

[Means for Solving the Problems] In order to solve the above problems, a soft PP inner layer made of a hard polypropylene (hereinafter referred to as PP) -based material of the first invention is used.
Adopted a structure in which it is completely covered with an outer layer made of a system material, the contact part with the body is thin, and is mainly made of the soft PP resin, and the second invention is thicker than the general part. A soft PP material is injected through the injection port into the cavity having a small width, and after the injection of the soft PP material is completed or while it is being injected, a hard PP material is injected from the injection port. It adopts a configuration that does.

[Operation] According to the first aspect of the present invention, the exterior resin product for automobiles is formed of a soft PP-based material at the contact portion with the body, so that no protector is required. Moreover, the interior of the exterior resin product for automobiles is made of a hard PP-based material and retains sufficient strength, so it is structurally superior. In addition, the hard
Since the PP material is completely covered with the soft PP material, it has a good appearance.

Further, according to the second invention, the exterior resin product for automobiles of the first invention can be obtained, and as the hard PP-based material, a low-cost and rigid material can be used.

[Embodiment] An embodiment in which the first invention and the second invention are embodied in a side spoiler will be described below with reference to FIGS. 1 to 5C.

First, a side spoiler as an automobile exterior resin product corresponding to the first invention will be described.

As shown in FIGS. 3 and 1 (cross-sectional view taken along the line BB in FIG. 3), the outer surface side of the body 2 located at the lower portion of the door 1 of the automobile has a curved portion 2a that is curved inward downward. Has become. In the curved portion 2a, a side spoiler 3 having a substantially S-shaped cross section is provided with a hole 4 provided in a contact surface of the side spoiler 3 with the curved portion 2a and a hole 5 provided in the curved portion 2a.
It is designed to be attached by a bolt (not shown) penetrating through.

As shown in FIG. 2 (enlarged view of part A in FIG. 1), the upper end portion of the side spoiler 3 has a lip portion 3a as a contact portion with the curved portion 2a of the body 2 with respect to the curved portion 2a. It is a line hit. This line contact usually has a width of about 1 to 3 mm.

The side spoiler 3 has a structure in which the hard PP-based material R _{1 which} is the inner layer 3b is completely covered with the soft PP-based material R ₂ which is the outer layer 3c by a so-called sandwich molding method. Although the thickness of the outer layer 3c is substantially uniform as a whole, in the vicinity of the lip portion 3a, only the outer layer 3c and the inner layer 3b are provided.
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The PP-based material R ₂ forming the outer layer 3c is a soft PP-based thermoplastic rubber-like material, specifically, PP in which rubber such as EPDM (ethylene / propylene / diene copolymer) is dispersed. Is. The PP-based material R ₁ forming the inner layer 3b is made of hard PP.
Examples of the system material include a PP material containing a filler such as glass fiber, calcium carbonate, and talc, and a foamed material of the PP material containing the filler.

Therefore, since the side spoiler 3 of the present embodiment has a structure in which the conventional protector is not used, the appearance of the side spoiler based on the unharmonious color tone between the protector and the side spoiler and the boundary line or the step between the protector and the side spoiler is used. There is no badness and it has a simple appearance of only the main body. The inner layer 3b of the side spoiler 3 is an outer layer 3c made of a soft PP-based material R _2.
It has a good appearance because it is completely covered with. Further, since the lip portion 3a is made of a soft PP-based material, it has good followability to the body 2 and does not damage the body 2.

Next, a manufacturing method of the side spoiler 3 corresponding to the second invention by the sandwich molding method will be described.

The sandwich molding method is a method in which two types of resins are divided into an outer layer (skin layer) 3c and an inner layer (core layer) 3b by an injection molding method and molded into a sandwich shape. Specifically, as shown in FIG. 4, the molding apparatus for performing the sandwich molding method is used to form an injection cylinder 6 for injecting a soft PP-based material R ₂ for forming the outer layer 3c and an inner layer 3b. Hard PP
An injection cylinder 7 that injects the system material R ₁ , and a general portion 11a having a large thickness width formed by the molds 9 and 10 of the resin supplied from both injection cylinders 6 and 7 and a width greater than the general portion 11a. A nozzle portion 8 for injecting into the cavity 11 having a small portion 11b.

In the molding apparatus, first, as shown in FIG. 5 (a), the outer layer is formed from the injection cylinder 6 through the nozzle portion 8.
A part of the soft PP-based material R ₂ which is the resin of 3c is injected into the general part 11a in the cavity 11 of the molds 9 and 10. Then, as shown in FIG. 5B, a hard PP material R ₁ which is a resin of the inner layer 3b is injected from the injection cylinder 7 through the nozzle portion 8 to the general portion 11a in the cavity 11 as well. At this time, the PP-based material R ₂ of the outer layer 3c that was first injected is the inner layer 3b that is injected later.
Is extruded into the PP-based material R ₁ and is pressed against the inner wall surface of the cavity 11. At this time, the soft PP-based material R ₂ may be simultaneously injected. Then, when the hard PP-based material R ₁ of the inner layer 3b is further injected into the cavity 11 from the general portion 11a, the state shown in FIG. 5 (c) is obtained. That is, the general portion 11a of the cavity 11 is completely covered with the hard PP-based material R ₁ with the soft PP-based material R ₂ , while the portion 11b having a small thickness width is formed with soft P-based material R _1.
Only P-based material R ₂ is filled. After the injection is completed, it is cooled for a predetermined time.

By such a sandwich molding method, the side spoiler 3 in which the hard PP-based material R ₁ of the inner layer 3b is completely covered with the soft PP-based material R ₂ of the outer layer 3c on the entire surface except the injection port is molded. A hard PP-based material R ₁ and a soft PP-based material R ₂ are provided in a cavity 11 composed of a general portion 11a corresponding to the main body portion of the side spoiler 3 and a portion 11b having a small thickness like the lip portion 3a. Since the and are molded by injection, the hard PP-based material R ₁ as the inner layer 3b is not injected into the lip portion 3a, and is formed only by the soft PP-based material R ₂ . Therefore, the lip portion 3a has sufficient flexibility, and the contact with the curved portion 2a of the body 2 is soft.

The resins of the inner layer 3b and the outer layer 3c are preferably compatible with each other, but the soft PP-based material R ₂ and the hard PP-based material
R ₁ has good compatibility. Further, when a PP-based material foam is used as the resin of the inner layer 3b, the foaming pressure prevents sink marks in the thick portion of the molded product.

According to the above-mentioned manufacturing method, the number of steps for adjusting the protector to the shape of the main body of the side spoiler 3 is not required unlike the conventional method, so that the number of working steps can be shortened. Further, since the protector is not used and the inner layer 3b is formed of an inexpensive PP material containing a filler, the manufacturing cost can be reduced.

The automotive exterior resin product of the first invention and the manufacturing method of the second invention are suitably applied to a rear garnish, a back panel garnish, a side protection molding, etc. in addition to the side spoiler. Since the contact portion 3a with the automobile body 2 is formed of the soft PP-based material R ₂ ,
It also functions as a covering material or sealing material that covers minute gaps.

[Effect of the Invention] The automotive exterior resin product of the first invention has a simple appearance that does not require a conventional protector, and has an excellent effect that the painted portion of the body contact portion is not scratched.

Further, according to the manufacturing method of the second aspect of the invention, there is an excellent effect that the number of working steps can be shortened and the manufacturing cost can be reduced.

[Brief description of drawings]

1 to 5 (c) are views showing an embodiment of the present invention, wherein FIG. 1 is a sectional view showing a side spoiler mounting structure, and FIG. 2 is an enlarged sectional view of part A of FIG. FIG. 3 is a perspective view of an automobile, FIG. 4 is a sectional view of a molding apparatus showing a sandwich molding method, FIGS. 5 (a) to 5 (c) are sectional views showing a molding state, and FIG. 6 is a conventional side view. It is sectional drawing which shows the attachment structure of a spoiler. 2 ... Body, 3a ... Lip part as contact part, 3b ...
… Inner layer, 3c …… Outer layer, 11 …… Cavity, 11a …… General part, 11b …… Small width part, R ₁ …… Hard PP material, R ₂ …… Soft PP material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenjiro Hagiwara 3-2-5 Kasumigaseki, Chiyoda-ku, Tokyo Mitsui Petrochemical Industry Co., Ltd.

Claims (2)

[Claims] 1. A is completely covered with an inner layer made of a polypropylene material of the hard (R ₁₎ (3b) polypropylene soft material outer layer of (R ₂₎ (3c), per part of the body (2) (3a) has a thin wall and is mainly formed of the soft polypropylene-based resin (R ₂ ), which is an exterior resin product for automobiles. 2. A portion (1) having a smaller thickness width than the general portion (11a).
The soft polypropylene material (R ₂ ) is injected into the cavity (11) having 1b) through the injection port, and after the injection of the soft polypropylene material (R ₂ ) is completed or while the injection is being performed, A method for producing exterior resin products for automobiles, characterized by injecting a hard polypropylene material (R ₁ ) from the outlet.