JPS61144328A - Blow molded article having skin and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain an excellent external appearance with simple structure having a few parts in number, by a method wherein the skin is joined with at least one surface of a molded material, a groove is formed on at least one surface adjoining to the surface and a terminal of the skin is made to turn in the groove. CONSTITUTION:In a door trim of a motor car, for example, a molded material 4 is made of PP which has been molded into a hollow state through blowing and a plane which is the surface adjoining to the front, a right and left sides and the bottom are provided respectively with grooves 6. The skin 6 possesses double layer structure which is constituted bya method wherein the surface layer 7 made of PVC and a cushion layer 8 made of foamed PP and is rich in elasticity are bonded together and the cushion layer 8 is joined strongly to the molded material 4 through anchorage effect and fusion based on in-mold blow molding. Edge parts of four sides of the skin 5 are bent respectively into the plane, right and left sides and bottom of the molded material 4 and terminals 9 of the sides each are made to turn in a groove 6. The terminals 9, therefore, of the skin 5 are hardly recognized visually from every direction.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a blow-molded article having a skin and a method for manufacturing the same.

(Prior Art) Conventional resin molded products having a skin, such as automobile door opening trims (hereinafter referred to as door trims), include the following.

■ As shown in Figure 5, injection molded product 5 made of ABS resin.
There is a door trim on which a soft skin 52 made of polyvinyl chloride resin (PVC) is attached with adhesive. In this door trim, the cut at the end of the skin 52 is visible and unsightly, so polypropylene resin (PP) or PV
A backing cover 53 made of C is fixed with screws 54 from the back side.

(2) As shown in FIG. 6, there is a door trim in which a PVC skin 52 is molded and a urethane resin foam 55 is foam-molded on the back side of the skin 52 in the mold. In this door trim as well, the lining cover 53 is fixed with screws 54 because the edges of the outer skin 52 are visible and unsightly. In addition, since the strength of the urethane resin foam 55 is not so high, in order to increase the strength of the door and the retention strength of the screws 54, a sheet metal or resin insert is inserted into the foam 55.
6 and installing the lining cover.

(2) As shown in FIG. 7, a skin 52 was set in a blow molding die (not shown), and a molded body 57 made of PP was in-mold blow molded on the back side of the skin 52. In this case as well, since the ends of the skin 52 are unsightly, it is necessary to attach the backing cover 53.

(Problems to be Solved by the Invention) The present invention attempts to solve the problem that the number of parts and manufacturing man-hours of the resin molded product increases due to the necessity of the above-mentioned backing cover, and the cost also increases. Yes, the first
The purpose of the invention is to provide an inexpensive blow-molded product with a skin that has a simple structure with a small number of parts and an excellent appearance, and the purpose of the second invention is to efficiently manufacture the blow-molded product with a small number of man-hours. The objective is to provide a manufacturing method that allows for

Structure of the Invention (Means for Solving Problems) The first invention includes joining a skin to at least one surface of a molded body, and forming a groove on at least one surface adjacent to that surface,
The second invention takes a method of wrapping the end of the skin around the wire groove, and the second invention sets the skin in the molding recess of the split mold, and makes the end protrude inward of the molding recess, and also extends inward from the opening edge of the molding recess. The process of setting the middle plate to form the reduced opening on the parting line of the split mold, the process of extruding the synthetic resin parison between the split molds, and the process of aligning the split molds and then blowing into the parison. We adopted a method that consists of a process, and a process of opening the split mold and removing the middle plate from the molded product.

(Function) In the first invention, since the groove of the molded body hides the end of the skin, the end is hardly visible from all directions even without providing the backing cover in the conventional example, and therefore, the appearance is improved.

In the second invention, simultaneously with the molding of the molded body by blow molding the parison, the parison hits the end of the intermediate plate to form a groove in the molded body, the skin and the molded body are joined by an anchor effect and fusion, and The end of the epidermis wraps around into the groove. Therefore, the number of manufacturing steps can be reduced.

(Example) Hereinafter, an example in which the present invention is embodied in a door trim of an automobile will be described with reference to FIGS. 1 to 4.

The door trim 1 of this embodiment is formed to be thin in order to expand the space inside the car, and is designed to have a front view (meaning the inside side of the car).
A protrusion 2 is provided at the top, and a recess 3 for attaching an armrest is provided at the center of the front. This door trim 1 is composed of a molded body 4 serving as a base and a skin 5 joined to the front surface of the molded body 4 by in-mold blow molding.

The molded body 4 is blow-molded from PP into a hollow shape, and grooves 6 are formed in each of the plane adjacent to the front, the left and right side surfaces, and the bottom surface.

The skin 5 has a two-layer structure in which a surface layer 7 made of PVC and a highly elastic cushion layer 8 made of foamed PP are bonded together.
The cushion layer 8 is firmly joined to the molded body 4 by the anchor effect and fusion based on in-mold blow molding. The edges of the four sides of the skin 5 are bent to the plane, left and right side surfaces, and bottom surface of the molded body 4, respectively, and the ends 9 of each side are bent.
is wrapped around into the groove 6.

In this embodiment configured as described above, the groove 6 hides the end 9 of the outer skin 5, so that the end 9 of the outer skin 5 is hardly visible from all directions even if the backing cover in the conventional example is not provided. Therefore, with a simple structure with a small number of parts,
It is possible to provide the terminal 9 with an invisible and excellent appearance, which greatly contributes to cost reduction. Further, since the skin 5 of this embodiment includes the cushion layer 8, a soft touch feeling can be obtained.

Next, an embodiment of a method for manufacturing the door trim 1 will be described.

The two molds shown in Figures 3 and 4 are split mold 1 for blow molding.
1.12, the split mold 11 on the right side of the figure has a molding recess 13 for molding the front side of the door trim 1, and the split mold 12 on the left side has a molding recess 14 for molding the back side of the door trim 1. are formed respectively.

First, the skin 5 is formed in advance into a shape similar to the molding recess 13 of the split mold 11 by vacuum forming or other mold forming, and then the excess portion of the edge thereof is trimmed. that time,
The end 9 of the skin 5 is left so as to protrude inward along the parting line of the split mold 11. This epidermis 5 is
It is set in the same molding recess 13 as shown in the figure.

Next, the middle plate 16 is set on the parting line of the split mold 11. The middle plate 16 is made of a material having high strength such as steel and is thinly formed to have a wall thickness of about 0.8 to 3 mm. Further, the middle plate 16 is divided into parts so as to be easily removed after blow molding, and an opening 15 is formed in the center thereof, which is smaller inward than the opening edge of the molding recess 13. Therefore, the end 9 of the skin 5 is brought into contact with the edge of the opening 15.

Next, a square annular PP parison 17 is extruded from an upper nozzle (not shown) between the two split molds 11 and 12. In this embodiment, the parison 17 is pushed out in the lateral direction of the door trim molded body 4 shown in FIG. is the direction of flow.

Next, as shown in FIG. 4, after aligning the split molds 11 and 12, the parison 1 is
Blow within 7 days. Due to this blowing pressure, the skin 5 is pressed against the molding recess 13 and the parison 17
is pressed against the back surface of the skin 5, the end of the middle plate 16, and the molding recess 14.

Therefore, the molded body 4 is formed into a hollow shape by the parison 17, and grooves 6 are formed in each of the plane, the left and right side surfaces, and the bottom surface of the molded body 4, which are the surfaces adjacent to the front side. At the same time, the cushion layer 8 of the skin 5 is firmly joined to the molded body 4 by the anchoring effect and thermal fusion, and the ends 9 of the skin 5 wrap around into each groove 6 and are joined. In particular, the PP foam of the cushion layer 8 and the P of the molded body 4
Since P is a homogeneous material, it is easy to fuse with each other.

Further, since the blowing pressure is much lower than the pressure during injection molding, the cushion layer 8 of the skin 5 will not be crushed. For the same reason, the thickness of the middle plate 16 can be made as thin as possible without deformation, and when steel is used, it is 0.8
Even fl can withstand practical use. The thinner the wall thickness is, the less visible the ends 9 of the skin 5 after manufacturing are, which contributes to improving the appearance.

Therefore, the appropriate thickness is 0.8 to 3 ms.

Next, after opening the split molds 11 and 12, the intermediate plate 16 can be removed from the molded body 4.

According to the above manufacturing method, the formation of the groove 6, the joining of the skin 5 and the molded body 4, and the wrapping of the end 9 of the skin 5 into the groove 6 are performed simultaneously with the molding of the molded body 4 by blow molding. The blow molded products of the above embodiments can be manufactured efficiently with a small number of man-hours.

It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiments, and can be embodied by making appropriate changes, for example, as follows.

(1) In the above embodiment, the grooves 6 were formed on all the surfaces adjacent to the front surface of the molded body 4, but the grooves 6 may be formed only on some of the surfaces, for example, the plane and the bottom surface. .

In this way, the surface on which the grooves 6 are formed can be arbitrarily determined depending on the shape, type, easily visible portion, etc. of the molded product.

(2) In the door trim l, after blow molding only the molded body 4, the skin 5 is pasted with adhesive, and the skin 5 is placed in the groove 6.
It is also possible to wrap around the terminal.

Effects of the Invention As detailed above, the first invention has a simple structure with a small number of parts, can provide an excellent appearance with no visible end of the skin, and has the effect of greatly contributing to cost reduction. The second invention has the effect that the blow-molded product of the first invention can be efficiently manufactured with fewer man-hours.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example in which the first invention is embodied in a door trim of an automobile, Fig. 2 is a sectional view thereof, and Fig. 3 is an embodiment in which the second invention is embodied in the method for manufacturing the above-mentioned door trim. 4 is a sectional view showing an advanced state of the manufacturing process, FIG. 5 is a sectional view showing a conventional example, FIG. 6 is a sectional view showing another conventional example, and FIG. 7 is a sectional view showing an advanced state of the manufacturing process. FIG. 7 is a sectional view showing still another conventional example. Molded body 4, skin 5, groove 6, terminal 9, split mold 11°12,
Molding recess 13, opening 15, middle plate 16, parison 17° Patent applicant Toyoda Gosei Co., Ltd. Agent
Patent Attorney On 1) Hironobu Figure 1 Figure 2 Figure 8 Figure 4

Claims (1)

[Claims] 1. A skin (5) is bonded to at least one surface of the molded body (4), and a groove (5) is formed on at least one surface adjacent to the skin (5).
6) is formed, and the end (9) of the epidermis (5) is formed in the groove (6).
A blow-molded product having a skin characterized by a wrap around the skin. 2. The blow-molded product having a skin as set forth in claim 1, wherein the skin (5) is provided with an elastic cushion layer (8). 3. Set the skin (5) in the molding recess (13) of the split mold (11) and let its end (9) protrude inward of the molding recess (13), and from the opening edge of the molding recess (13) The step of setting the middle plate (16) forming the inwardly reduced opening (15) on the parting line of the split molds (11, 12), and the step of setting the synthetic resin parison ( After extruding the parison (17) and matching the split molds (11, 12), the parison (1
7) The process of blowing inside the mold, opening the split molds (11, 12), and molding the molded product (1).
1. A method for producing a blow-molded product having a skin, the method comprising the step of removing the middle plate (16) from ).