JP7762078B2 - Materials - Google Patents

Description

The present invention relates to a component including a decorative surface.

Conventionally, many resin molded products with patterns such as embossing formed on their surfaces have been known as resin molded products used as interior components such as the upper housing of an automobile shift lever device, console boxes, and instrument panels. The embossing pattern is formed, for example, by transferring the pattern on the molding surface of a resin molding die (see, for example, Patent Document 1). The pattern on the molding surface of the die is formed, for example, by a embossing process using chemical etching.

Texturing by etching allows a pattern consisting of gently continuing, finely textured surfaces to be created on the molding surface of a mold. The pattern on the molding surface is transferred to the resin molded product produced by this mold, creating a gently textured surface. This type of textured pattern on a resin molded product disperses light that enters the textured surface in multiple directions, resulting in a matte finish.

Japanese Patent Application Laid-Open No. 2000-025046

However, the grain patterns on resin molded products that can be formed in this manner have little variation in surface properties, making it difficult to fully meet the needs for diverse designs.

The present invention was made in consideration of the above-mentioned problems with the conventional technology, and aims to provide components with improved design.

The present invention is a component including a design surface composed of at least one of a flat surface and a curved surface,
The design surface has fan-shaped areas of the same specifications arranged in a scale pattern,
A plurality of convex ridges or concave grooves are formed inside the sector-shaped region, the convex ridges or concave grooves being aligned along arcs having a smaller diameter than the arcs forming the outer edge of the sector, while sharing a center with the arcs forming the outer edge of the sector ,
The component is characterized in that, inside the fan-shaped region, there is a difference in the arrangement pitch of the convex ridges or concave grooves that are arranged in parallel in the radial direction of the fan shape, and the convex ridges or concave grooves vary in density in the radial direction of the fan shape.

In the member of the present invention, a plurality of convex ridges or concave grooves are formed along an arc that shares a center with the fan shape inside a sector-shaped region arranged like a scale. Inside this sector-shaped region, the arrangement pitch of the convex ridges or concave grooves varies, and the density of the convex ridges or concave grooves varies in the radial direction of the sector.

For example, if the reflection of light is weak in the ridges or grooves, the ridges or grooves will appear dark, and shadows or variations in brightness will occur depending on the density of the ridges or grooves. Furthermore, if the reflection of light is strong on the surface of the ridges or the inner surface of the grooves, the reflection intensity of light is likely to vary depending on the longitudinal direction of the surface or inner surface, i.e., the direction of the ridges or grooves. In such cases, inside a fan-shaped region, the ridges or grooves in a fan-shaped area with an even narrower angle than the fan-shaped area will appear to shine, and variations in brightness may occur inside the fan-shaped region. This is because the direction of the ridges or grooves is the same in a narrow-angle fan-shaped area.

In this way, the component of the present invention enhances its design through the use of shadows and light and dark within the fan-shaped areas arranged in a scale-like pattern.

FIG. An enlarged view of a portion of the top surface of a resin molded product. FIG. Cross-sectional view of the molding surface. An explanatory diagram of the pattern. FIG. 4 is an explanatory diagram of areas that make up a pattern. An illustration of how the pattern reflects light. A photograph of the top surface of a resin molded product (partially enlarged).

The embodiments of the present invention will be specifically described using the following examples.
Example 1
This example relates to a resin molded product 1 which is an example of a member including a design surface composed of flat and curved surfaces. The resin molded product 1 of this example will be described with reference to FIGS.

The resin molded product 1 (Figure 1) is a component that forms the upper housing of a vehicle shift lever device (not shown). The resin molded product 1 has a roughly rectangular front shape and has a side wall 18 on its outer periphery. When the shift lever device is attached to the vehicle, the top surface 1S of the resin molded product 1 is exposed to the passenger compartment and is either flush with the surrounding area or recessed from the surrounding area. Therefore, the side wall 18 of the resin molded product 1 is not visible to vehicle occupants. The top surface 1S of the resin molded product 1 is a decorative surface that decorates the passenger compartment. Hereinafter, the top surface of the resin molded product 1 will be referred to as the decorative surface 1S.

In an assembled shift lever device (not shown), the shift lever operated by the vehicle driver is positioned through a lever through-hole 10 provided on the inner periphery of the resin molded product 1, which serves as the upper housing. The lever through-hole 10 is a rectangular opening that allows the shift lever to be operated in the shift direction along the fore-and-aft direction of the vehicle and in the select direction along the vehicle width direction. In the resin molded product 1, a long, narrow indicator window 101 is provided in a position adjacent to the lever through-hole 10 in the vehicle width direction. This indicator window 101 is an opening that allows visibility of an indicator panel (not shown) that displays the layout of the shift ranges, such as the parking range, drive range, neutral range, and reverse range.

The resin molded product 1 is a molded product made of a resin material such as ABS resin, polycarbonate resin, or ASA resin. The resin material in this example is a colored resin material kneaded with a colorant such as a black pigment. The resin molded product 1 in this example is made of this resin material and is black in color even when unpainted.

A pattern 100 (see Figure 2) is formed over the entire design surface 1S of the surface of the resin molded product 1. This pattern 100 is a pattern in which fan-shaped regions 11, on which arc-shaped convex ridges 1R are formed, are arranged in a scale-like pattern. Note that Figure 2 is an enlarged view of the region 19 indicated by the circular dashed line in Figure 1. The pattern 100 made of the convex ridges 1R corresponds to the pattern on the molding surface 40 of the molding die 4 (see Figure 3) used to mold the resin molded product 1, and is formed during resin molding.

Now, we will explain the molding die 4 for the resin molded product 1. The molding die 4 (Figure 3) is a mold consisting of a combination of a metal upper die 42 and a lower die 41. The molding die 4 has holes (not shown) for pouring molten resin material into the interior when the upper die 42 and lower die 41 are clamped together. The resin molded product 1 can be molded by injecting resin material into the interior of the clamped molding die 4. The lower die 41 is the mold that molds the shape of the design surface 1S, which corresponds to the top surface of the resin molded product 1. The upper die 2 is the mold that molds the shape of the back side of the resin molded product 1. With the molding die 4 illustrated in Figure 3, the resin molded product 1 is molded upside down.

The molding surface 40 of the lower mold 41 is provided with a pattern corresponding to the pattern 100 (Figure 2) on the design surface 1S of the resin molded product 1. The pattern on the molding surface 40 of the lower mold 41 is a pattern consisting of concave grooves 4T that correspond to the convex ridges 1R that make up the pattern 100. The grooves 4T (Figure 4) on the molding surface 40 are grooves with a wedge-shaped cross section formed, for example, by laser processing. The convex ridges 1R that make up the pattern 100 (see Figure 2) on the design surface 1S of the resin molded product 1 are formed to correspond to the wedge-shaped grooves 4T in cross section and have a triangular cross section. The depth D of the grooves 4T on the molding surface 40 is approximately 10 μm. The width W of the grooves 4T is 50 μm.

The molding surface 40 of the lower mold 41 is machined, polished to a mirror finish, and then laser-machined to form the grooves 4T. The decorative surface 1S of the resin molded product 1 molded using this molding surface 40 is a surface composed of convex ridges 1R and a glossy surface 118, as will be described in detail later with reference to Figure 7.

The design surface 1S (Figs. 5 and 6) of the resin molded product 1 has a scale-like pattern 100 that creates a three-dimensional effect and enhances its aesthetic appeal. As described above, this pattern 100 is formed by arc-shaped ridges 1R. The smallest unit of the pattern 100 is a fan-shaped region 11 (Fig. 6). The pattern on the design surface 1S of the resin molded product 1 is formed by seamlessly combining fan-shaped regions 11 of the same specifications in a scale-like pattern.

The fan-shaped region 11 (Figure 6) is a region in which multiple concentric arc-shaped ridges 1R are formed. Here, concentric arc-shaped ridges 1R refer to ridges formed along an arc that shares a center with the arc that forms the outer edge of the fan-shaped region 11. Because the centers of the arc-shaped ridges 1R are aligned, the width of the gap between any two ridges 1R in the fan-shaped region 11 is the same and constant at each position in the circumferential direction. Meanwhile, the arrangement pitch of the parallel ridges 1R in the radial direction of the fan-shaped region 11 varies, resulting in a variation in the density of the ridges 1R in the radial direction of the fan shape. Here, the arrangement pitch refers to the center-to-center distance between two adjacent ridges 1R in the radial direction of the fan shape (dimension P in Figure 7). In this example, the closer to the outer periphery of the arc, the wider the arrangement pitch of the ridges 1R, making the ridges 1R denser, and the closer to the center of the arc, the wider the arrangement pitch of the ridges 1R, making the ridges 1R sparser.

The height of the ridges 1R is 10 μm, corresponding to the approximately 10 μm depth D of the grooves 4T (see Figure 4) on the molding surface 40. The formation width of the ridges 1R is 50 μm, corresponding to the 50 μm formation width W of the grooves 4T on the molding surface 40. The arrangement pitch (dimension P in Figure 7) between two adjacent ridges 1R is 120 to 480 μm. Because the formation width W of the grooves 4T is 50 μm, the width of the gap between adjacent ridges 1R (dimension G in Figure 7) is 70 to 430 μm.

Next, the visual effect of the pattern 100 formed on the design surface 1S of the resin molded product 1 will be explained with reference to Figure 7. This figure illustrates an example of a cross-sectional structure perpendicular to the arc-shaped ridges 1R. The figure shows the cross sections of two adjacent ridges 1R.

As shown in Figure 7, the design surface 1S of the resin molded product 1 on which this pattern 100 is formed is composed of convex ridges 1R and glossy surfaces 118 between the ridges 1R. Here, the glossy surfaces 118 are highly smooth surfaces formed by the mirror-finished molding surface 40 of the molding die 4. For example, when viewing the design surface 1S from viewpoint A in Figure 7, the direction in which light is reflected varies depending on the slopes on both sides of the ridges 1R and the glossy surfaces 118 between the ridges 1R.

Furthermore, the direction of the ridges 1R (the tangent direction of the arc) changes in the circumferential direction, and the orientation of the slopes of the ridges 1R differs depending on the circumferential position. Therefore, for example, the intensity of light reflected by the slopes of the ridges 1R (the surfaces of the ridges 1R) changes depending on the circumferential position of the arc-shaped ridges 1R.

This is easily seen in the photograph of the design surface 1S in Figure 8, for example. In the photograph in the same figure, the reflected light is stronger in the arc-shaped ridges 1R of each sector-shaped region 11 where the tangent direction slopes downward to the right from the horizontal direction in the figure. Therefore, in the photograph in the same figure, the ridges 1R belonging to the narrow-angle sector area 111 to the right of the center of the sector-shaped region 11 shine, and this narrow-angle sector area 111 appears bright. Furthermore, in this narrow-angle sector area 111, the width of the gaps between adjacent ridges 1R is narrower and denser on the outer periphery, making it appear brighter than the inner periphery.

In the example photograph of Figure 8, the light and dark areas due to the density of the arc-shaped ridges 1R in the fan-shaped region 11, and the light and dark areas within the region 11 depending on the direction (tangential direction) of the ridges 1R, create complex light and dark areas throughout the pattern 100, creating a three-dimensional effect.

For example, when the viewpoint moves (e.g., from A to B in Figure 7), the conditions for reflecting light in each fan-shaped region 11 can change. For example, the direction of the ridges 1R (the tangent direction of the arc) in which the reflected light is stronger may change as the viewpoint moves. In such cases, the narrow-angle fan-shaped area 111 that appears bright within each fan-shaped region 11 changes as if it were rotating around the center of the fan shape. Furthermore, as a result of the viewpoint moving, the reflected light from the glossy surface 118 may become stronger. In this case, the inner periphery, where the ridges 1R are coarse and the glossy surface 118 occupies a higher proportion, of the fan-shaped region 11, has stronger reflected light and appears brighter than the outer periphery, where the ridges 1R are dense.

In addition, in the resin molded product 1 of this example, the design surface 1S is not flat, but has curved surfaces at the edges of the upper and lower ends. On a curved surface, the direction of light reflection varies depending on the position. As a result, on a curved surface, the direction of the ridges 1R, where the light reflection intensity is stronger, may differ depending on the position, or the ridges 1R and the glossy surface 118 may switch sides that strongly reflect light. In this way, on curved surfaces, more complex shadows or light and dark areas may occur, producing a variety of visual effects.

As described above, the resin molded product 1 of this example has a highly varied and colorful visual effect due to the pattern 100 on the design surface 1S, resulting in an excellent aesthetic appearance. This pattern 100 is made up of fan-shaped regions 11 arranged in an orderly manner to form scales, and the viewer is struck by the beauty of the orderly arrangement.

In each of the fan-shaped regions 11 that make up the pattern 100, the density of the arc-shaped ridges 1R varies, creating shade and light and shade, creating a three-dimensional effect. The entire pattern 100 can produce a wide variety of visual effects, such as changes in the shade and light of each fan-shaped region 11 depending on the viewing direction, which can change the three-dimensional effect. Furthermore, on surfaces where the slope of the surface to which the pattern 100 is applied varies, such as curved surfaces, different visual effects can be produced at different positions.

In addition, the design surface 1S of the resin molded product 1 in this example can create a visual effect on the surface without requiring work processes such as painting or surface treatment. As a result, this resin molded product 1 is an excellent product that exhibits high design quality while keeping production costs down. Because the resin molded product 1 in this example is molded from a black pigmented resin material, it does not require painting.

The fine ridges 1R on the design surface 1S have the effect of preventing fingerprints and scratches on the glossy surface 118 between the ridges 1R. Therefore, the design surface with ridges 1R can maintain its aesthetic appeal for a long time.

In this example, a fan-shaped region 11 is shown with ridges 1R that follow an arc of a constant diameter, but the region may also be a fan-shaped region with ridges that follow an elliptical arc. In this case, the outer edge of the fan shape will be an elliptical arc.

In this example, the resin molded product 1 is an upper housing for a shift lever device. However, it may also be a resin molded product used for decorative vehicle components, such as interior vehicle components such as console boxes and instrument panels, or exterior vehicle components such as grilles and wheel caps. In addition to decorative vehicle components, the resin molded product may also be used for decorative components for various items, such as home appliances, office automation equipment, and furniture. Colored resin materials other than black may also be used as the resin material. The surface shape of the design surface is not limited to a flat surface, but may be a convex or concave curved surface, or may include a convex or concave step. A pattern consisting of ridges 1R may be provided on only a portion of the design surface, rather than the entire surface. The cross-sectional shape of the ridges 1R may be a mountain shape, a semicircular shape, a trapezoidal shape, or other shape.

In this example, laser processing is used as an example of a processing method for forming grooves 4T on the molding surface 40 of the mold 4. Instead of laser processing, grooves 4T may be formed by engraving, cutting, or other processes. Furthermore, in addition to injection molding as used in this example, other molding methods such as blow molding and compression molding may also be used as a resin molding method for the resin molded product 1.

In this example, the visual effect is enhanced by providing convex ridges 1R on the surface of the resin molded product 1, but concave grooves may also be provided instead of the convex ridges 1R. Concave grooves can also produce a similar visual effect to this example. However, in terms of preventing fingerprints and other residue from adhering to the design surface, ridges 1R are expected to provide a greater anti-fouling effect.

In this example, the formation width of the ridges 1R is 50 μm. The formation width of the ridges 1R is preferably a width that is difficult to see when viewed from the extension direction of the ridges 1R, and is preferably 10 to 200 μm. If it is less than 10 μm, the reflection of light on the inclined surface of the ridges 1R may be difficult to see. If it exceeds 200 μm, the ridges 1R may be easily seen as lines, and the difference in appearance from conventional line patterns may be reduced. Preferably, the formation width of the ridges 1R is 50 μm ± 20 μm. If the formation width of the ridges 1R is 50 μm ± 20 μm, the ridges 1R are difficult to see as lines when viewed from the extension direction of the ridges 1R, and the areas of ridges 1R lined up in the same direction are seen as if they were a single surface.

In this example, the arrangement pitch of the ridges 1R (dimension P in Figure 7) is 120 to 480 μm. The width of the gaps between the ridges 1R should be 20 to 800 μm. If it is less than 20 μm, the width of the flat surface between adjacent ridges 1R will be reduced, reducing the glossy surface that reflects light, which may reduce the contrast between light and dark and make it difficult to visually perceive the three-dimensional effect. If it exceeds 800 μm, the width of the flat surface will increase, resulting in excessive glossy surface that reflects light, which may be perceived as a simple glossy design. The maximum width of the gaps between the ridges 1R is preferably 150 μm. If the gap width is 150 μm or less, the width of the flat surface can ensure a glossy surface that reflects light appropriately, resulting in a well-balanced contrast between light and dark and an easier-to-visual three-dimensional effect.

In this example, the height of the ridges 1R is 10 μm. The height of the ridges 1R is preferably 2 to 30 μm. If the height is less than 2 μm, the reflective surface of the ridges 1R becomes smaller, reducing the difference in reflection between the flat portion and the inclined surface, which may make it difficult to visually recognize the three-dimensional effect. If the height exceeds 30 μm, this may have an adverse effect on the releasability of the resin molding. Preferably, the height of the ridges 1R is 5 to 25 μm. If the height of the ridges 1R is 5 to 25 μm, the angle of the uneven slope becomes appropriate and the difference in reflection between the flat portion and the inclined surface can be ensured, making the three-dimensional effect more easily visible and achieving the effect of improving the releasability of the resin molding.
In this example, a metal mold 4 is used as an example, but a resin mold may also be used.

Although specific examples of the present invention have been described in detail above as examples, these specific examples merely disclose examples of the technology encompassed by the claims. Needless to say, the scope of the claims should not be interpreted as being limited by the configurations, numerical values, etc. of the specific examples. The claims encompass technologies that incorporate various modifications, alterations, or appropriate combinations of the specific examples, utilizing publicly known technology and the knowledge of those skilled in the art.

1. Resin molded products (components)
1R ridge 1S design surface (top surface)
11 Fan-shaped area 118 Glossy surface 100 Pattern 4 Mold 4T Groove 40 Mold surface 41 Lower mold 42 Upper mold

Claims (5)

A component including a design surface composed of at least one of a flat surface and a curved surface,
The design surface has fan-shaped areas of the same specifications arranged in a scale pattern,
A plurality of convex ridges or concave grooves are formed inside the sector-shaped region, the convex ridges or concave grooves being aligned along arcs having a smaller diameter than the arcs forming the outer edge of the sector, while sharing a center with the arcs forming the outer edge of the sector ,
A component characterized in that, inside the fan-shaped region, there is a difference in the arrangement pitch of the convex ridges or concave grooves that are arranged in parallel in the radial direction of the fan shape, and the convex ridges or concave grooves vary in density in the radial direction of the fan shape. 2. The component according to claim 1, wherein, inside the sector-shaped region, the arrangement pitch narrows or widens as it approaches the outer periphery of the sector. 3. A member according to claim 1, wherein the surface of the inner surface of said sector-shaped region, which forms a gap between adjacent said convex ridges or concave grooves, is formed as a glossy surface. 4. The member according to claim 1, wherein convex ridges are formed inside the sector-shaped region. A component according to any one of claims 1 to 4, characterized in that it is an interior component for a vehicle.