JPH06190862A - Manufacture of molding - Google Patents

Abstract

PURPOSE:To obtain excellent quality in appearance by ensuring excellent adhesion to a vehicle body and assuredly preventing generation of sink mark at a terminal part. CONSTITUTION:A main body 5 molded previously by extrusion is arranged in a gap S of a mold 9 in such a manner that an end face 5a faces a cavity 15. An SEBS is injected into the cavity 15 until the cavity is filled with it. After the injection is completed, a compressing core 13 is pushed up inwardly in the cavity 15 by a piston 14 for compressing the SEBS. The compressing core 13 has a protrusion 13a nearly conformed to a shape of a designed face A of a terminal part 6 in other part than a flat part corresponding to a part to which a double-faced tape is to be stuck. Therefore, a melting resin for forming the terminal part 6 is compressed as a whole and is made to be nearly uniform in thickness. Accordingly, volumetric shrinkage of the resin material is reduced remarkably, and also the shrinkage difference will be almost out. In addition, at a non-designed face B, the part to which the double-faced tape is to be stuck becomes flat, thereby ensuring a sticking area.

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 molding such as a side molding mounted on both sides of a vehicle body of an automobile. More specifically, the invention relates to a long body portion and an end surface of the body portion. The present invention relates to a method for manufacturing a molding including a formed terminal portion.

[0002]

2. Description of the Related Art Conventionally, as a technique of this kind, for example, in a side molding 21 as shown in FIG.
2 is formed in a long shape by a known extrusion molding method.
Due to the nature of the manufacturing method, the main body 22 has substantially the same cross-sectional shape at any position. In addition, the main body 22
In order to improve the design of the entire side molding 21, the terminal portion 23 continuously formed on the end surface of the is thinned toward the tip side (right side in the drawing).

The side molding 21 is formed as follows. That is, first, the main body 22 formed by the extrusion molding method is attached to the mold 2 including the upper mold 24 and the lower mold 25.
6 is arranged at a predetermined position (left side in the figure). Next, a molten resin is injected and filled from a gate 28 (right end in the figure) into a cavity 27 having a shape of a terminal portion 23 composed of a molding recess 24a of the upper die 24 and an upper surface 25a of the lower die 25. Then, after the molten resin is cooled and solidified, the mold 26
By dividing the mold, the side molding 21 in which the main body portion 22 and the terminal portion 23 are integrated is obtained.

However, in the above-mentioned method of manufacturing the side molding 21, the shrinkage amount of the thick portion is relatively larger than that of the thin portion due to the volume shrinkage due to the cooling of the resin material. turn into. For this reason, there is a possibility that a partial dent (sink) may be generated on the surface of the thick portion of the terminal portion 23 of the side molding 21 due to the difference in volume contraction. In addition, such a sink mark is side mall 2
If it occurs on the first design surface (upper surface in the figure), the appearance quality may be deteriorated.

On the other hand, as a measure for eliminating the sink mark, there is a method of using a mold 43 having a plurality of protrusions 42 formed on the upper surface of a lower mold 41, as shown in FIG.
According to this method, as shown in FIG. 11, the terminal portion 45 is obtained in which the ribs 44 are formed so that a plurality of ribs 44 are formed on the non-design surface side (the lower side of the drawing). Therefore, the terminal unit 4
It is considered that the volume shrinkage amount can be reduced because the volume of the whole 5 decreases.

[0006]

However, in the above-mentioned conventional technique, when the side molding having the above-mentioned terminal portion 45 is to be adhered to the vehicle body with a double-sided tape or the like, the non-designed surface of the terminal portion 45 is used. In this case, only the ribs 44 are adhesive surfaces, and the adhesive area is smaller than that in the case where the non-designed surface is a flat surface. Therefore, the adhesive strength of the side molding to the vehicle body may be reduced. In addition, since the ribs 44 having a large thickness are formed, the thick ribs 44 may appear as shadows (fine sink marks) on the design surface of the side molding, which may result in deterioration of the appearance quality. It was

The present invention has been made to solve the above problems, and an object thereof is to provide a long main body and a terminal portion continuously formed on an end surface of the main body. It is an object of the present invention to provide a method for manufacturing a mall that can secure good adhesion to a vehicle body and can reliably prevent sink marks from being generated at a terminal portion to obtain excellent appearance quality.

[0008]

In order to achieve the above object, according to the present invention, there is provided a molding which is attached to a vehicle body through an attaching means attached to a non-designed surface and which is a long body in advance. In the method for manufacturing a molding, in which a portion is formed and is continuous with an end surface of the main body portion to form an end portion, the main body portion is formed so that the end surface faces a cavity for forming the end portion. Placed in a mold, in the mold on the non-design surface side of the terminal portion, in a shape substantially conforming to the design surface of the terminal portion at a location other than the flat surface portion corresponding to the location where the attaching means is attached. A compression core having a convex portion is provided so as to be able to move forward and backward with respect to the cavity, and after filling the molten resin in the cavity, the compression core is moved in the direction of the cavity to compress the molten resin, Thickness of the terminal part is almost uniform It has as its gist that the content was.

[0009]

According to the above construction, the elongated main body is arranged in the mold so that the end surface faces the cavity for molding the terminal portion. Further, the compression core is provided in the mold on the non-design surface side of the end portion so as to be able to advance and retract with respect to the cavity. Then, after the molten resin is filled in the cavity, the compression core is moved toward the cavity. Therefore, the molten resin is compressed, and the terminal portion is continuously formed on the end surface of the main body portion by the compressed resin.

At this time, the compression core has a convex portion having a shape substantially conforming to the design surface of the terminal portion at a portion other than the flat portion corresponding to the portion to which the attaching means is attached. Therefore, the molten resin for forming the end portion is wholly compressed by the compression core and has a substantially uniform thickness due to the presence of the convex portion. Therefore, since the end portion is compressed and the wall thickness is substantially equal, the volume shrinkage of the resin material after molding is significantly reduced, and the sink mark does not occur on the design surface. Further, on the non-design surface side of the terminal portion, the portion to which the attaching means is attached is not compressed by the convex portion, and thus has a flat shape. Therefore, the pasting area of the pasting means is sufficiently secured.

[0011]

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

FIG. 2 is a perspective view showing a part of the side molding 1 as a molding manufactured in this embodiment, and FIG. 3 is a rear view showing a part of the side molding 1. The side moldings 1 are mounted on both sides of a vehicle body (not shown), and have a long shape as a whole. That is, the double-sided tapes 2, 3, and 4 are attached to the side molding 1 on both sides and ends of the non-designed surface B, and the double-sided tapes 2 to 4 are attached to both sides of the vehicle body. It has been done.

As shown in FIG. 4, the side molding 1 has a body portion 5 formed in an elongated shape and an end surface 5a of the body portion 5.
And a terminal portion 6 formed continuously. The body portion 5 has a two-layer structure including a skin layer 7 and a core layer 8. The skin layer 7 is made of relatively soft SEBS (styrene-ethylene-butylene-styrene copolymer resin), and the core layer 8 is made of relatively hard low linear expansion polypropylene. The terminal portion 6 is made of SEBS, like the skin layer 7.

The main body 5 is formed by a well-known two-layer extrusion molding method, and has substantially the same cross-sectional shape (in the present embodiment, a kamaboko shape) at any position. In addition, the terminal portion 6 has a tapered shape in order to improve the design of the entire side molding 1. More specifically, in the terminal portion 6, the distance from the vehicle body to the design surface A is gradually shortened toward the tip portion.

The side molding 1 including the main body portion 5 and the terminal portion 6 has the main body portion 5 and the terminal portion 6 which are continuously formed flush with each other on the design surface A, and has a sense of unity as a whole. ing. Further, the non-designed surface B side of the main body portion 5 is formed into a flat surface. Furthermore, the non-designed surface B of the terminal portion 6
The side is formed as a flat surface at least in the portion where the double-sided tapes 2 to 4 are attached. Then, the portion other than the flat surface is recessed in a shape substantially conforming to the design surface A side of the terminal portion 6.

Next, a mold for forming the side molding 1 will be described. As shown in FIGS. 1 and 5, the mold 9 comprises an upper mold 10 and a lower mold 11, and the lower surface of the upper mold 10 has a molding recess 10 a having a shape substantially similar to that of the terminal portion 6.
Are formed. Further, a part of the lower mold 11 is formed with a through hole 12 opening in a rectangular shape on the upper surface of the lower mold 11. In the through hole 12, a compression core 13 which is vertically slidable is arranged. A piston 14 for pushing up the compression core 13 is provided below the compression core 13 so as to be vertically movable. On the upper surface of the compression core 13, a convex portion 13a is formed at a portion other than the portion corresponding to the portion where the double-sided tapes 2 to 4 are attached. The convex portion 13 a has a shape substantially conforming to the design surface A of the terminal portion 6. In addition, the convex portion 13 on the upper surface of the compression core 13
The parts other than a have a planar shape. The molding recess 10a, the upper surface of the lower mold 11 and the upper surface of the compression core 13 form a cavity 15 for forming the terminal portion 6. Further, the lower mold 11 is formed with a gate 16 that opens to the end of the cavity 15. Further, the main body portion 5 is arranged in a space S communicating with the cavity 15 and between the upper mold 10 and the lower mold 11.

Next, a method of manufacturing the side molding 1 will be described. First, the main body portion 5 is formed in advance by the extrusion molding method described above. Subsequently, as shown in FIG. 1, the main body 5 is arranged in the gap S of the mold 9 so that the end surface 5 a of the main body 5 faces the cavity 15. At this time, the compression core 13 and the piston 14 are arranged such that the upper surface of the compression core 13 is located slightly below the upper surface of the lower mold 11.

With the main body 5, compression core 13 and piston 14 arranged as described above, the melted SEBS is injected through the gate 16 and the melted SEBS is injected into the cavity 15, as shown in FIG. Let it fill.
After the filling is completed, the inlet side of the gate 16 is closed to prevent the molten SEBS in the cavity 15 from flowing backward. In this state, the upper surface of the compression core 13 is the lower mold 1.
The space shifted downward from the upper surface of 1 is also filled with the molten SEBS, and the portion serves as the compression margin 17 by the compression core 13.

Then, melted SE filled as described above.
In order to compress the BS, as shown in FIG. 7, the piston 1
The compression core 13 is pushed up inward of the cavity 15 by 4. Then, when the flat surface of the upper surface of the compression core 13 is flush with the upper surface of the lower mold 11, the upward movement of the piston 14 is stopped. By this pushing-up operation, the cavity 15
The molten SEBS inside is compressed by the amount of the compression margin 17 described above.

Thereafter, the molten SE compressed as described above
After the BS is cooled and solidified, the mold 9 is divided into molds to obtain the side molding 1 in which the main body portion 5 and the terminal portion 6 are integrated as shown in FIGS.

In the above compression, the compression core 13 is used.
Has a convex portion 13a having a shape substantially conforming to the design surface A of the terminal portion 6 at a portion other than the flat portion corresponding to the portion to which the double-sided tapes 2 to 4 are attached. Therefore, the molten resin for forming the terminal portion 6 is compressed as a whole, and the distance from the vehicle body to the design surface A is substantially shorter by the convex portion 13a, although the distance from the vehicle body is gradually shortened toward the tip portion. It is assumed to be of uniform thickness. Therefore, the resin forming the terminal portion 6 is uniformly compressed, and the wall thickness is substantially uniform as a whole, so that the volume shrinkage of the resin material after molding is significantly reduced, and the difference in shrinkage at each location is almost zero. Disappear. As a result, it is possible to reliably prevent the occurrence of sink marks on the side of the design surface A of the terminal portion 6, and it is possible to obtain excellent appearance quality.

On the non-design surface B side of the terminal portion 6,
The places where the double-sided tapes 2 to 4 are attached are not compressed by the convex portion 13a but are flat by being compressed by the flat surface of the upper surface of the compression core 13. Therefore, the attachment area of the double-sided tapes 2 to 4 can be sufficiently secured. As a result, the double-sided tape 2 firmly attached to the non-designed surface B side
By 4, the good adhesiveness to the vehicle body can be ensured, and in turn, problems such as peeling of the side molding 1 can be prevented.

Further, in this embodiment, the cavity 15
Since the molten SEBS inside is compressed, it is possible to spread the molten SEBS to every corner inside the cavity 15. Therefore, it is possible to prevent a gap from being formed between the main body portion 5 and the terminal portion 6 on the design surface A of the side molding 1, and to further improve the appearance quality. You can

In addition, in this embodiment, the base end surface of the terminal portion 6 on the side of the body portion 5 has the same area and the same shape as the end surface 5a of the body portion 5. Therefore, the joint area of the both 5 and 6 can be secured to the maximum, and the joint strength of the both 5 and 6 can be improved.

The present invention is not limited to the above-described embodiments, but may be implemented as follows with a part of the configuration appropriately changed without departing from the spirit of the invention. (1) In the above embodiment, in order to secure the joint area between the main body 5 and the terminal 6, the main body 5 side of the terminal 6 (left side in FIG. 7).
The base end surface of the main body portion 5 has the same area and the same shape as the end surface 5a of the main body portion 5. However, as shown in FIG. 8, for example, a portion corresponding to the base end surface is also projected on the upper surface of the compression core 18. You may make it provide the part 18a. In this case, since the convex portion 18a can be set to have the same shape as the design surface A of the terminal portion 19, the wall thickness of the terminal portion 19 can be made almost equal at any place. As a result, it is possible to more reliably prevent the occurrence of sink marks.

(2) In addition to the examples shown in the above examples, as the resin forming the side molding 1, a thermoplastic resin such as rubber-modified polypropylene, polyester elastomer, or polyvinyl chloride (PVC) may be used. However, when PVC is used, it is preferable that a heat-welding adhesive is adhered to the end surface 5a of the main body 5 and the adhesive is interposed at the interface with the terminal portion 6. In this way, by interposing the adhesive agent, the adhesive force between the main body portion 5 and the terminal portion 6 can be made stronger than in the case where nothing is interposed. Of course, S in the above embodiment
Even when EBS is used, an adhesive may be interposed.

(3) In the above embodiment, the main body 5 was formed by a known extrusion molding method, but the main body 5 may be formed by any method, for example, an injection molding method. You may use what was done.

(4) In the above embodiment, the sticking means is embodied as the double-sided tapes 2-4, but it may be embodied as an adhesive instead.

[0029]

As described in detail above, according to the method for manufacturing a molding of the present invention, a molding having a long main body and a terminal portion continuously formed on an end face of the main body is provided. ,
At the time of molding the terminal portion, the compression core having a resin forming the terminal portion and having a convex portion having a shape substantially conforming to the design surface of the terminal portion at a portion other than the flat portion corresponding to the portion to which the attaching means is attached. I tried to compress with. Therefore, it is possible to ensure good adhesion to the vehicle body, to reliably prevent the occurrence of sink marks at the terminal portion, and to obtain a molding having an excellent appearance quality.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a mold and the like for molding a side molding in an embodiment embodying a method for manufacturing a molding according to the present invention.

FIG. 2 is a perspective view showing a part of a side molding according to an embodiment.

FIG. 3 is a back view showing a part of the side molding according to the embodiment.

FIG. 4 is a cross-sectional view showing a part of a side molding according to an embodiment.

5 is a cross-sectional view taken along line XX of FIG. 1 in one embodiment.

FIG. 6 is a partial cross-sectional view of a mold showing a state in which a molten resin is filled in a cavity for molding the end portion of the side molding in one embodiment.

FIG. 7 is a partial cross-sectional view of a mold showing a state in which a resin filled in a cavity is compressed when molding an end portion of a side molding in one embodiment.

FIG. 8 is a partial cross-sectional view of a mold showing a state in which a resin filled in a cavity is compressed when molding an end portion of a side molding in another embodiment.

FIG. 9 is a partial cross-sectional view showing a mold for molding a terminal portion of a side molding according to a conventional technique.

FIG. 10 is a partial cross-sectional view showing a mold for molding a terminal portion of a side molding according to a conventional technique.

11 is a cross-sectional view showing a terminal portion of a side molding molded by the mold of FIG. 10 in the prior art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Side molding as a molding, 2, 3, 4 ... Double-sided tape as a sticking means, 5 ... Main body part, 5a ... End surface, 6 ...
Terminal part, 9 ... Mold, 13, 18 ... Compression core, 13a,
18a ... convex part, 15 ... cavity, A ... design surface, B ... non-design surface.

Claims (1)

[Claims] 1. A molding (1) to be mounted on a vehicle body via a sticking means (2, 3, 4) stuck to a non-designed surface (B), which has a long body portion ( 5) is formed,
In the method for manufacturing a molding, wherein a terminal portion (6) is formed continuously with an end surface (5a) of the body portion (5), the body portion (5) is formed so that the end surface (5a) is the terminal portion (6). It is arranged in the mold (9) so as to face the cavity (15) for molding, and the sticking is performed on the mold (9) on the non-design surface (B) side of the terminal portion (6). For compression, which has a convex portion (13a) having a shape substantially conforming to the design surface (A) of the terminal portion (6) at a portion other than the flat portion corresponding to the portion to which the attaching means (2, 3, 4) is attached. Core (13)
Is provided so as to be able to move forward and backward with respect to the cavity (15), and after the molten resin is filled in the cavity (15), the compression core (13) is moved toward the cavity (15) to move the molten resin. Compress the terminal part (6)
A method for manufacturing a molding, characterized in that the thickness of the molding is substantially uniform.