JPH0477650B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a method for processing a plastic molding used for protection and decoration on the outer surface of an automobile body, and particularly relates to a method for processing the end portion of the molding. .

(Prior Art) In recent years, various plastic moldings have been used on the outer surfaces of automobile bodies to protect and decorate the vehicle body. Among these, extrusion moldings made of soft vinyl chloride resin or foam thereof having appropriate elasticity and flexibility are often used. The reason why extrusion molded products are often used is that they are long products with a constant cross section, and have the advantage that they can be cut to any desired length, such as the length of a vehicle. However, if such an extrusion molded product is simply cut, the aesthetic appearance of the ends is poor, and the cut ends tend to be sharp, which is not preferable from the viewpoint of safety.

On the other hand, as mentioned above, this molding is used to decorate the side of the car body, etc., and decorations such as strips or decorative tapes of a different color from the molded product body are pasted or embedded on the surface of the extruded molded product, which is the visible part. Those with a similar configuration are also often used. This decorative body is usually attached or embedded integrally during the molding of the extrusion molded product, that is, during extrusion molding, and is continuous in the longitudinal direction of the extrusion molded product. Therefore, when the extrusion molded product is cut, the cut end of the decorative body is exposed at the cut end.

Therefore, conventionally, the molding material of such an extrusion molded product is made into a product (mall) by the following post-processing or secondary molding method.

(1) A method of attaching a cap, which is a separate molded product, to the cut end to make the end of the molding beautiful.

(2) Place the end of the extruded product in an injection mold having a desired cap-shaped cavity, and inject molten plastic into the cavity to mold the cap and place the molded cap on the end of the extruded product. How to adhere.

(3) A method of cutting the surface of the end portion of an extruded product into a desired shape and pressing a heating jig against the cut surface to melt and make the cut surface beautiful.

(4) An extruded rod or block made of a thermoplastic resin with a large dielectric loss, such as vinyl chloride resin, is placed in a mold with a small dielectric loss, and the rod or block is molded into a predetermined mold by high-frequency heating. A method of manufacturing a molding that is formed into a shape (see Japanese Patent Application Laid-open No. 108110/1983).

(Problems to be Solved by the Invention) However, the above processing methods (1) to (3) all have the disadvantage that a clear dividing line appears between the processed end portion and the unprocessed portion. Furthermore, even if a decorative tape or the like is stuck to the surface of the extrusion molded product, it may be hidden by the cap or the decorative tape or the like must be cut, so that the decorative tape or other decoration may not be visible at the edges. There is a problem that it cannot be done even if it has reached the level of the department.

On the other hand, the method (4) using high-frequency heating has the advantage of being able to produce products with non-uniform cross-sectional shapes; Since it is desirable to place the cut pieces into the mold, many have the problem of requiring multiple pieces and requiring operations such as weighing to fit them into the mold volume. Furthermore, since one molding is obtained from a plurality of pieces, there is also the problem that weld lines and the like appear on each piece.

Therefore, it is an object of the present invention to provide a novel molding method that does not cause such drawbacks.

(Means for Solving Problems) The gist of the present invention is to cut the back surface of the end portion of a molding material extruded from a material with large dielectric loss, such as soft vinyl chloride resin. The end part is made thinner and has a continuous smooth surface on the visible side.
Between the split molds, at least one of the split molds is made of a material with low dielectric loss, and the other split mold has a mold cavity that substantially defines the surface shape of the visible part of the molding following a groove-shaped opening that opens outside the mold. The material end portion is installed so that the continuous visible portion side surface of the thin material end portion is in contact with the mold cavity surface that defines the visible portion side surface shape, and the split mold is closed. A method for processing a molded end portion is characterized in that the end portion of the material is pressed and deformed, and the end portion of the material is subjected to high frequency heating through a split mold to be shaped into a desired end shape.

(Function) The end portion of the molding material extruded from soft vinyl chloride resin or the like is made thinner by cutting the back side thereof, and has a continuous smooth surface on the visible side. This thinned end part is installed so that its visible part side surface is in contact with the mold cavity surface following the groove-shaped part opening outside the mold, and by closing the split mold, the visible end part of the material is The portion side surface is pressed against the cavity surface and deformed to approximately form the desired cavity shape. At this time, internal strain occurs at the end of the material due to pressure contact stress, but in this state, a high frequency voltage is applied to the end of the material through the split mold, so the end of the material installed between the dies quickly self-heats,
Finally, it is plasticized and plastically deformed (shaped) into a predetermined cavity shape. In other words, the stress strain caused by the closed welding of the split type disappears, and the shape of the closed welding is permanently deformed. In addition, at this time, since the surface of the visible part of the terminal part constitutes a smooth surface that is continuous with the surface of the general part of the material, a molding terminal part with no seam is formed on the visible part surface of the terminal part of the molding. It will be done. Furthermore, if a decorative body such as a decorative tape is attached to the surface of the visible part at this time, the decorative body is also shaped into a predetermined shape by the mold surface, so that the molding terminal can be A molding having decorations on its surface can be obtained.

(Example) Examples will be explained below based on the figures. Figure 1 is a sectional view showing a state in which the end portion of the material whose back surface has been cut and thinned is installed between the divided molds before closing, and Figure 2 is the divided mold. A sectional view showing a state in which the mold is closed and a high frequency voltage is applied to the press-deformed end of the material, FIG. 3 is a perspective view of the end of the molding material before processing, and FIG. FIG. 3 is a perspective view of an example of a processed molding.

The processing device used in the present invention consists of split molds 11 and 12 connected to a high frequency generator 40. The split molds 11 and 12 are made of epoxy resin, silicone resin,
It is made of a material with low dielectric loss such as ceramic, and a cavity 13 is provided on the joint surface to give a predetermined shape to the end portion 22 of the molding material 20. As shown in the figure, the molding mounting surface of the cavity 13 is formed by the mold surface 16 of one of the divided molds 12, and the visible part side surface shape of the desired molding end shape is roughly formed by the mold surface of the other divided mold 11. configured to specify. In the illustrated example, the depth of the cavity 13 gradually decreases from a groove-like portion 14, which will be described later, toward the end, and is provided so as to form a smooth cavity surface.

Note that one of the split molds 11 has a cavity surface that substantially defines the surface shape of the visible portion side of the molding terminal portion 22.
Next to the cavity 13, a groove-shaped portion 14 is provided, the other end of which opens outside the mold, and serves as an insertion path for the molding material 20. That is, only the end portion 22 of the material 20 can be inserted into the divided molds 11 and 12.

In addition, when forming a molding mounting surface of a simple shape such as a planar shape using one cavity surface 16 of the split mold as described above, the metal plate constituting the electrode plate 30 to be described later On the other hand, in the illustrated example, it may be configured to also serve as the split mold 12. That is, it is sufficient that at least one of the split molds is made of a material with low dielectric loss.

Electrode plates 3 are provided on the upper and lower surfaces of the split molds 11 and 12.
0,30 is attached, and its electrode plate 3
0 and 30 so that the cavity 13 and a part of the groove-shaped portion 14 following it are sandwiched therebetween. These electrode plates 30, 30
As shown in the figure, it is connected to a high frequency generator 40 so that a high frequency voltage can be applied between the split molds 11 and 12.

The molding material 20, which is a workpiece, is a long non-foamed or foamed product extruded into a predetermined cross-sectional shape from a plastic with a large dielectric loss, such as a soft vinyl chloride resin. An example is shown in FIG. In order to obtain the molding material 20 made of foam, a known chemical foaming agent may be mixed into a raw material such as a soft vinyl chloride resin, and foaming may be carried out simultaneously with extrusion molding. The illustrated molding material 20 has a decorative body 21, such as a plastic film or a metal-deposited film, which is different in color from the material 20, attached to the visible side surface of the molding material 20. It is preferable to attach the material 20 so that its side edges are buried in the material during extrusion molding of the material 20.

Next, the processing method of the present invention will be explained step by step. First, a predetermined amount of the back side of the end portion of the molding material 20 cut into a predetermined length is removed. The cutting is performed on the terminal portion 22 as shown by the dashed line in FIG.
It is preferable to remove it so that it becomes thin. FIG. 1 shows a vertical sectional view in the longitudinal direction of the material 20 placed between the divided molds 11 and 12 after the deletion. At this time, the visible part side surface of the material is left as a continuous smooth surface without cutting or the like.

As shown in the figure, the continuous visible part side surface opposite to the cut back side is placed on one of the split molds 12 so as to be placed against the mold cavity 13 that defines the surface shape, and the terminal part 22 Split molds 11 and 12 with the general part of the material following the groove facing the grooved part 14
Close. At this time, it is preferable that a protrusion 15 is provided upright on the cavity surface 16 of the split mold 12, and that the material 20 is positioned by the protrusion 15.

By closing the split molds 11 and 12, the visible part side surface of the material terminal part 22, which is continuous with a smooth surface from the general part of the material, is pressed against the cavity surface that defines its shape and is deformed to form the second part. As shown in the figure, it becomes a curved surface that roughly follows the cavity surface. At this time, if a decorative tape 21 or the like is attached to the surface of the visible part of the material, the decorative tape 21 or the like is also deformed along the cavity surface.

In this state, a high frequency voltage is applied between the electrode plates 30, 30. At this time, at least one of the split molds 11 and 12, for example, the split mold 11 that defines the shape of the visible portion surface side of the material terminal portion 20, is made of silicone resin or the like with low dielectric loss. It penetrates most of the material and acts on the material end portion 22 with a large dielectric loss installed in the cavity and a part of the material 20 following it. That is, the material terminal portion 22 sandwiched between the electrode plates 30, 30 receives high frequency and generates heat from within, becomes plasticized in a short period of time, and further becomes molten. Therefore, the end portion of the material 22 which is pressed against the cavity surface and is deformed releases the deformation stress and strain through plasticization and becomes uniform, and at this time, the visible part of the end portion becomes the general material Since the molding has a smooth surface that is continuous with the surface of the molding, a molding end portion having no seam is formed on the visible surface of the end portion of the molding. still,
The material portion following the material terminal portion 22 is the electrode plate 30, 3.
Since the portion located between 0 is small, the degree of self-heating is also small. Further, since the material portion following the terminal portion 22 is continuous with the material portion not located between the electrode plates 30, 30, the degree of plasticization decreases as the distance from the terminal portion 22 increases.
The portion that is removed from the gap is hardly subjected to any heating action, so no deformation or the like occurs. In other words, it maintains its extruded shape.

In addition, when the decorative tape 21 or the like is pasted or buried on the surface of the material 20, the decorative tape 21 or the like is deformed into a predetermined curved surface by the closing of the split molds 11 and 12 as described above. etc. are also the terminal unit 22
By shaping, a predetermined curved surface (line) is drawn and fixed to the surface of the terminal part.

After the end portion of the material is plasticized and shaped in this manner, the high frequency is stopped, the material is cooled, and the material is demolded. FIG. 4 shows an embodiment of the end portion of the molding 20a processed according to the present invention.

The above is an example in which the shape of the molding terminal section is substantially formed using one of the split molds, but it goes without saying that the shape of the terminal section may be formed using both split molds. be. Further, when one of the cavity surfaces of the split mold has a simple shape such as a flat surface, one of the split molds may be constructed of an electrode plate as described above. Alternatively, the top and bottom of the split mold may be changed, and the shape of the surface side of the molding terminal portion may be defined on the bottom side.

Furthermore, as shown by the broken line in FIG. 1, a clip 17 made of a material with low dielectric loss, such as polyacetal resin, is provided on the mold surface 16 on the back side of the terminal part, and its head is used to shape the terminal part. In some cases, the terminal portion may be attached and fixed.

(Effects of the Invention) As described above, the present invention, when processing the end portion of a molding material made of extrusion molding, removes a predetermined amount of the back surface of the end portion, and places the end portion in a split mold having a predetermined cavity for the end portion. After the end part is installed, the end part is self-heated from the inside by high frequency and plasticized, so deformation stress and strain during pressure welding are released, and the visible part surface of the part becomes similar to the general part of the material. Since the surface is continuous with the surface, it is possible to provide a molding end portion that has no seam on the visible surface of the end portion of the molding. Further, even if a decorative body such as a decorative tape is attached to the molding material, it can be processed in the same way, and an extremely beautiful molding with the decorative body extending to the ends of the molding can be produced. It also has the advantage that a fixing device such as a clip can be implanted at the end of the molding at the same time.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the end of the material whose back surface has been cut and thinned between the split dies before closing, and the end of the material that has been made thinner by cutting the back side is installed between the split dies. Figure 2 is a high-frequency voltage applied to the end of the material that has been press-fitted and deformed after the split dies are closed. FIG. 3 is a perspective view of the end portion of the molding material before processing, and FIG. 4 is a perspective view of an example of the molding processed according to the present invention.

Claims (1)

[Claims] 1 The terminal part of the molding material extruded from a material with high dielectric loss such as vinyl chloride resin is thinned by cutting the back side, and the terminal part is made of a smooth surface with a continuous visible part side. At least one of the split molds is made of a material with low dielectric loss, and one of the split molds has a mold cavity that substantially defines the surface shape of the visible part of the molding terminal following the groove-shaped part that opens outside the mold. A device is installed between the divided molds so that the continuous visible part side surface of the thin material end part is in contact with a mold cavity surface that defines the visible part side surface shape, and by closing the divided molds, the material is removed. 1. A method for processing a molded end portion, which comprises press-deforming the end portion and applying high-frequency heating to the end portion of the material through a split mold to shape the end portion into a desired end shape.