JP2007083434A - Resin molded part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin molded part capable of ensuring the rigidity of a locking structure part while preventing the appearance failure such as the "weldline", "sink", etc. occurring on the side of the design surface of the locking structure part. <P>SOLUTION: The resin molded part is equipped with a part main body (1) for constituting the design surface 11 of the locking structure part 2 and at least one locking structure part 2 wherein a pawl part 22 is formed on one side of a plate-shaped member 21 erected on the back 12 of the design surface and the through-hole 23 for piercing the plate shaped member 21 in its thickness direction is provided to the root of the plate shaped member 21 while a slope 13 becoming high on the side opposite to the protruding direction of the pawl part 22 is provided to the part where the root of the plate shaped member 21 of the back 12 of the design surface is positioned. Further, leg parts 24 and 25 widened in the direction having height reference of the slope are provided to the root of the plate-shaped member 21. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a molded product having a locking structure portion for attaching to other parts on the back surface of a design surface using a resin or the like as a molding material, and more specifically, an appearance defect occurring on a design surface near the locking structure portion. It is related with the resin molded component which can also ensure the rigidity of a latching structure part, preventing it.

  In a molded part using a resin or the like as a molding material, in order to assemble a plurality of molded products, a locking structure portion having a claw shape is often installed on the back surface of the design surface of the part. In this locking structure portion, the filling amount of the material is larger than that in the peripheral portion, so that the flow of the molding material is slow. As a result, the material flowing from the left and right peripheral portions of the locking structure portion collides after entering the locking structure portion, so that a “weld line” is likely to occur on the design surface. Further, since the locking structure portion is thicker than its peripheral portion, “sink” is likely to occur.

  Conventionally, measures such as changing to a material that does not easily cause appearance defects such as weld lines and sink marks have been taken. However, in this measure, since the type of material is restricted, the applicable parts are limited due to the performance of the material. Furthermore, since it is difficult to completely eliminate appearance defects such as weld lines and sink marks, it can be applied only to inconspicuous parts even when appearance defects occur.

  Further, as a method other than the countermeasures based on the material, there is a countermeasure by changing the part shape. For example, in Patent Document 1, a rib is provided under the mounting claw and a space is formed between the mounting claw and the back surface of the design surface, thereby eliminating the thick wall and preventing the occurrence of sink marks. However, this measure has a problem that it is not possible to ensure the rigidity of the locking structure portion with respect to a load caused by contact of other components. (See Patent Document 1).

Japanese Patent No. 3338617

  The present invention has been made in view of such a situation, and an object of the present invention is to prevent appearance defects such as “weld lines” and “sinks” generated on the design surface side of the locking structure portion, and to An object of the present invention is to provide a resin molded part capable of ensuring the rigidity of the stopper structure.

  In order to solve the above-described problems of the prior art, the present invention includes a thin component main body constituting a design surface and at least one claw portion formed on one surface side of a plate-like member standing on the back surface of the design surface. In a resin molded part provided with a locking structure portion, and the locking structure portion can lock the component main body to the mounting site thereof, the plate-like member is penetrated in the thickness direction at the base of the plate-like member. In addition to providing a through-hole, an inclined surface that is higher on the side opposite to the protruding direction of the claw portion is provided in a portion of the back surface of the design surface where the plate-like member root is located.

  Moreover, in this invention, the leg part extended in the direction with the height difference of the said inclined surface was provided in the base of the said plate-shaped member. Further, the front end side of the plate-like member of the through hole has a mountain shape with the center protruding toward the front end side.

  As described above, the resin molded part according to the present invention includes a thin part main body constituting a design surface and at least one latch formed with a claw portion on one surface side of a plate-like member standing on the back surface of the design surface. In a resin molded part provided with a structure part and capable of locking the component main body to the attachment site by the locking structure part, penetrating through the plate-like member in the thickness direction at the base of the plate-like member Since a hole is provided and an inclined surface that is higher on the side opposite to the protruding direction of the claw portion is provided in the portion where the plate-like member root is located on the back surface of the design surface, the engagement structure portion and the back surface of the design surface The flow of the resin material to the component main body is ensured by suppressing the inflow of the resin material to the locking structure portion by the space portion formed between them. Is generated at the locking structure. That the appearance of such as "weld line" and "sink" failure can be prevented.

  At the same time, due to the configuration of the inclined surface on the back side of the design surface provided with the locking structure portion, the cross-sectional area of the connection portion between the plate-like member of the locking structure portion and the component main body is reduced when the locking structure portion is locked. In addition to being enlarged in the bending direction, the distance between the high-order side of the connecting portion and the claw portion is shortened, so that the bending strength of the locking structure portion increases. As a result, it is possible to prevent a deterioration in the appearance of the locking structure portion while preventing a decrease in strength of the locking structure portion due to the provision of the through hole and ensuring the rigidity of the locking structure portion. Moreover, on the claw portion side of the locking structure portion, a sufficient space can be secured between the lower side of the connecting portion and the claw portion, and the mounting portion can be reliably locked.

  Further, since the leg portion is provided at the base of the plate-like member so as to extend in the direction in which the inclined surface has a height difference, the bending strength of the locking structure portion, that is, the locking force of the locking structure portion is further increased. In particular, since the leg portion can be provided avoiding the position of the through hole, it is possible to avoid a decrease in the strength of the locking structure portion due to the through hole, and to provide an optimal locking structure for preventing poor appearance. Can be configured.

  Furthermore, since the front end side of the plate-like member of the through hole has a mountain shape with the center protruding toward the front end side, stress concentration on the plate-like member root portions located on both sides of the through hole is alleviated. In addition, the strength reduction due to the through hole is suppressed as much as possible, and the flow of the resin material from the through hole to the tip side is improved, so that the moldability of the locking structure portion itself due to the through hole can be suppressed.

  With the above features, the present invention prevents the “weld line” and “sink” that are likely to occur on the design surface of the portion where the locking structure portion is provided, and further solves the problem of rigidity reduction by the conventional method. In addition, the rigidity against the load caused by the contact at the time of locking to the mounting portion is ensured. The present invention can be applied to various resin molded parts used for adding a design effect to the part or protecting the part by locking to the part or covering the part. Applicable. It is suitable for automobile parts such as wheel caps that require a high level of locking performance and a high locking force to prevent falling off.

  In recent years, due to environmental problems, reduction of volatile organic compounds such as volatile organic compounds has become a challenge for automobile parts, and reduction of volatile organic compounds generated by painting is also required for resin parts. There is a growing need for the use of molding materials that are directly colored with colorants such as dyes. Recently, there is an increasing demand for parts having improved texture such as a metallic feeling and a glitter feeling, and molding with a molding material to which a glittering material such as aluminum flakes and glass flakes is added is also required.

  Molding materials that are directly colored with colorants such as pigments and dyes tend to have poor appearance such as weld lines, and in molding materials to which glittering materials are added, the flow of molding materials at the locking structure is delayed. Turbulent flow is generated, and the glittering material is easily oriented, so that appearance defects such as weld lines are likely to occur compared to the molding material without the glittering material, and it was difficult to use. By applying it, it is possible to effectively prevent weld lines generated on the design surface of the portion where the locking structure portion is provided, not only in the molding material without the glittering material but also in the molding material with the glittering material added. Therefore, the development of unpainted parts can be expanded. Furthermore, by increasing the use of non-painted resin parts, the cost of molded products can be reduced by eliminating the painting process.

  Hereinafter, details of the present plan will be described using a case where the present invention is applied to a resin wheel cap of a vehicle. FIG. 1 is a front view of the entire design surface 11 of the wheel cap 1 as seen from the back side, and FIG. 2 is a perspective view of the same. 3 is a cross-sectional view taken along the line AA of FIG. 1, FIG. 4 is an enlarged view of the locking structure portion 2 shown in FIG. 2, and FIG. 5 is an enlarged view of the vicinity of the locking structure portion 2 of FIG. is there.

  As shown mainly in FIG. 2, the wheel cap 1 is provided with a locking structure portion 2 for attaching the wheel cap 1 to the wheel on the back surface 12 of the design surface. Four places are arranged at equal intervals in the circumferential direction. These locking structures 2 extend in the circumferential direction, which corresponds to the edges of the four bulged portions (recessed portions as viewed from the design surface 11 side, groove shape in the illustrated example) of the design surface back surface 12 for reasons described later. It is erected on the existing inclined surface 13.

  As shown in FIGS. 4 and 5, the locking structure portion 2 is formed with a claw portion 22 on the front end side of a plate-like member 21 flat in the extending direction of the inclined surface 13, and the claw portion 22 is a plate. The protrusion 21 protrudes toward the lower side of the inclined surface 13 (the center side of the wheel cap 1), and the further tip side of the claw portion 22 is inclined like a wedge. With this configuration, when the locking structure portion 2 is advanced toward a wheel (not shown), the claw portion 22 comes into contact with an edge portion such as a locking hole provided in the wheel, and the plate-like member 21 is opposite to the claw portion 22. By bending in the direction, the claw portion 22 gets over the edge portion and fits into the locking hole, whereby the wheel cap 1 can be attached to the wheel.

  A through-hole 23 is provided at the base of the plate-like member 21 so as to penetrate the plate-like member 21 in the thickness direction (radial direction of the wheel cap 1). The design surface back surface 12 side of the through hole 23 is formed on the inclined surface 13 common to the design surface back surface 12, while the front end side (claw portion 22 side) of the through hole 23 faces the front end side for reasons described later. It is formed in the shape of a mountain with a central bay.

  Further, leg portions 24 and 25 are provided at the bases of the plate-like member 21 located on both sides of the through hole 23 so as to spread in the direction in which the inclined surface 13 has a height difference (thickness direction of the plate-like member 21). Yes. In the illustrated example, the leg portions 24, 24 project to the lower side (the center side of the wheel cap 1) of the inclined surface 13, and the leg portions 25, 25 project to the higher side (the peripheral side of the wheel cap 1) of the inclined surface 13. Yes.

  In manufacturing the wheel cap 1 configured as described above, for example, it is divided into a design surface 11, a peripheral portion of the design surface back surface 12, and a central portion of the design surface back surface 12, and the center portion of the design surface back surface 12 is Injection molding is performed using a mold (not shown) divided into four slide cores corresponding to the four locking structures 2.

  At this time, in the conventional locking structure portion without the through hole 23, the molding material injected from the injection port (14) into the mold passes through the locking structure portion (2) as compared with the peripheral portion thereof. As the amount of material filling increases, the flow of the material slows, and as a result, the molding material that flows at high speed around the locking structure collides with the downstream side of the locking structure, resulting in a “weld line”. In addition, there is a problem that “sink” is likely to occur because the locking structure portion is thicker than its peripheral portion.

  However, in the present invention, by providing the through hole 23 in the locking structure portion 2, the base of the plate-like member 21 has a shape with two legs, and the molding material is formed in the locking structure portion 2. Since the entrance into which it flows is small and divided into two parts (parts corresponding to the legs 24 and 25), the molding material is prevented from flowing into the locking structure 2 at a stretch, and the flow similar to the surroundings is prevented from flowing into the locking structure 2 It is also maintained on the downstream side of this, and the generation of weld lines can be prevented. Moreover, since the capacity | capacitance itself of the latching structure part 2 can also be made small, generation | occurrence | production of the sink by the shrinkage | contraction of resin can also be prevented.

  On the other hand, due to the presence of the through hole 23, the locking structure portion 2 is connected to the wheel cap 1 body only at both side portions of the through hole 23, but by providing the locking structure portion 2 on the inclined surface 13, The cross-sectional area of the connection portion to the wheel cap 1 body is enlarged in the direction in which the locking structure portion 2 bends when locked, and the distance between the high-order side of the connection portion and the claw portion 22 is shortened. Therefore, the bending strength of the locking structure portion 2 increases. Furthermore, by providing leg portions 24 and 25 extending in the inclination direction of the inclined surface 13 at the base of the plate-like member 21, the bending strength of the locking structure portion 2, that is, the locking of the locking structure portion 2 is achieved. The force is maintained, and a decrease in strength of the locking structure portion 2 due to the through hole 23 can be avoided.

  Furthermore, in this invention, as shown in FIG. 4, the shape of the upper part of the through-hole 23 is formed in the mountain shape which the center protruded toward the front end side. By adopting such a shape, the stress concentration on the plate-like member 21 (portion connected to the leg portion 24) located on both sides of the through hole 23 is alleviated, and the strength reduction due to the through hole 23 is suppressed as much as possible, and the locking structure Sufficient strength can be ensured over the entire portion 2. In addition, the flow of the resin material from the through hole 23 toward the tip side is improved, and it is possible to suppress a decrease in moldability of the locking structure portion 2 itself due to the through hole 23.

  Moreover, since the design surface back surface 12 on which the plate-like member 21 is erected forms an inclined surface 13 that becomes higher in the opposite direction to the claw portion 22, the design surface back surface 12 and the claw portion 22 side of the locking structure portion 2 A sufficient space can be secured between the claw portion 22 and the wheel can be securely locked to the mounting portion.

  As shown in FIG. 2, the inlet 14 for injecting the molding material into the mold is provided at the end of the design surface back surface 12. This is because a circular character line 15 is provided at the end of the design surface 11, so even if “sink” occurs near the inlet 14 where “sink” is likely to occur, This is because it can obscure "sinks" and has little effect on the appearance.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

It is a front view which shows the design surface back surface of the wheel cap which implemented the resin molded component of this invention. It is a perspective view which shows the design surface back surface of the wheel cap which implemented the resin molded component of this invention. It is AA sectional drawing of FIG. It is an expansion perspective view which shows the latching structure part which concerns on embodiment of this invention. It is an expanded sectional view showing the locking structure part concerning the embodiment of the present invention.

Explanation of symbols

1 Wheel cap (component body)
DESCRIPTION OF SYMBOLS 11 Design surface 12 Design surface back surface 13 Inclined surface 14 Inlet 15 Character line 2 Locking structure part 21 Plate-shaped member 22 Claw part 23 Through-hole 24,25 Leg part

Claims (3)

  A thin component main body constituting a design surface, and at least one locking structure portion having a claw portion formed on one surface side of a plate-like member erected on the back surface of the design surface. In the resin molded part that can lock the component main body to the attachment site, a through hole that penetrates the plate member in the thickness direction is provided at the base of the plate member, and the plate shape on the back surface of the design surface A resin molded part, wherein an inclined surface is provided at a portion where a member base is located, and an inclined surface is provided on a side opposite to a protruding direction of the claw portion.   The resin molded part according to claim 1, wherein a leg portion is provided at a base of the plate-like member so as to spread in a direction in which the inclined surface has a height difference.   3. The resin molded part according to claim 1, wherein the front end side of the plate-like member of the through hole has a mountain shape with a center protruding toward the front end side. 4.

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