JP2009166782A - Fixation structure of resin molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixation structure of a resin molding which is screw-fastened to the other member via a boss vertically provided on the resin molding, wherein the fixation structure is capable of preventing a surface sink and enhancing the strength of the boss for screw-fastening. <P>SOLUTION: A door storage compartment 30 is screwed to a predetermined position in a door trim body 20. The boss 33 for screw-fastening vertically provided on a predetermined position of a rear face of the door storage compartment 30 is configured to have a board thickness of one third to a half of a general board thickness of the door storage compartment 30. The enhanced strength of the screw-fastening fixation part is secured by incorporating reinforcing ribs 34 into a periphery surface of the boss 33 for screw-fastening so that lack of its rigidity is compensated while preventing the surface sink generated on the surface of the door storage compartment 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin molded product fixing structure suitable for fixing a resin molded product such as a door pocket to a door trim main body, and in particular, it has a beautiful appearance that does not cause appearance sink and can enhance rigidity. The present invention relates to a fixing structure of a resin molded product that can satisfy both the appearance performance and the strong mounting strength.

  FIG. 8 shows a door pocket 1 attached to a lower surface of a door trim body (not shown). This door pocket 1 is formed by injection-filling a general-purpose thermoplastic resin such as polypropylene resin into an injection mold, A clip seat 2 is formed at three locations on the lower edge of the door pocket 1 in order to fix it to the door trim body, which is a mating part, and a clip (not shown) is attached to the clip seat 2, With this clip, the door trim body or the door trim body and the door panel are fastened together. Further, in addition to the clip mounting portion, a screw fixing boss 3 is erected at a screw fixing point.

  FIG. 9 is a perspective view of the screw fixing boss 3 as seen from the back side of the door pocket 1, and FIG. 10 is a plan view of the screw fixing boss 3. In addition, regarding the dimensional relationship of the conventional screwing boss 3, the inner diameter a1 of the screwing boss 3 is set to 3.2 to 3.5 mm, and the outer diameter a2 is determined based on the inner diameter a1. Since the strength is insufficient unless the outer diameter a2 of the screw-fixing boss 3 is at least twice the inner diameter a1, the outer diameter a2 is at least twice the inner diameter, numerically 7.0 mm, and the plate thickness d is 1 .75mm respectively. In order to attach the door pocket 1 to the door trim main body, which is a counterpart component, after positioning the door pocket 1 at an appropriate position with respect to the door trim main body, a screw is fastened and fixed in the screw fixing boss 3 from the back side of the door trim main body. Then, the attachment of the door pocket 1 is completed. For example, Patent Document 1 discloses a conventional example of a fixing structure for fixing a resin molded product with screws.

JP-A-6-173913

  Thus, conventionally, when fixing the door pocket 1 to the door trim body, which is a counterpart, with a screw, the outer diameter of the screw-stop boss 3 standing on the back surface of the door pocket 1 is 7.0 mm, and the inner diameter is 3 Since the thickness is 0.5 mm, the thickness of the screw-fixing boss 3 is set to 1.75 mm. Accordingly, when the screw fixing boss 3 having a plate thickness of 1.75 mm is erected on the back surface while the general plate thickness of the door pocket 1 is 2.3 mm, the product surface of the door pocket 1 is sinked and the appearance is increased. There is a defect that causes a defect. As a countermeasure, a pedestal is set at the base of the screw-fixing boss 3 to prevent the appearance sink. However, in this case, a separate slide core for forming the pedestal is required. There is a problem that the cost increases.

  This invention was made in view of such circumstances, and is a resin molded product fixing structure for fixing a resin molded product to a counterpart part with a screw, without causing an increase in mold cost, An object of the present invention is to provide a fixing structure for a resin molded product that can enhance the strength of a screw-fixing boss and can prevent the appearance of sink marks as much as possible.

  In order to achieve the above object, the present invention provides a resin molded product fixing structure in which a resin molded product molded into a required shape is fixed to a predetermined position of a counterpart part with a screw, and a predetermined position on the back surface of the resin molded product. The screw-fixing boss is erected on the surface, and after positioning the resin molded product at a predetermined position on the surface of the mating part, the screw is fastened and fixed into the screw-fixing boss of the resin molded product from the back side of the mounting hole of the mating part. Accordingly, in the fixing structure of the resin molded product for fixing the resin molded product, the boss for fixing the screw is a thin-walled boss adjusted within a range of 1/2 to 1/3 of the plate thickness of the general part of the resin molded product. A structure is adopted, and a reinforcing rib that compensates for a decrease in rigidity due to a thin wall is integrated with the outer peripheral surface of the screw-fixing boss.

  Here, the resin molded product can be applied to the door pocket, and the mating part to which the door pocket is attached can be applied to the door trim body. In addition, the present invention can be applied to a structure in which resin molded products such as ornament panels and various covers are fixed to an interior trim body as a counterpart part. The resin molded product is formed by molding a general-purpose thermoplastic resin such as polypropylene resin, polyethylene resin, or ABS resin into a required shape by injection molding or the like.

  In addition, since the screw boss has a standard specification for the screw screw diameter, its inner diameter is predetermined to 3.5 mm, and the screw boss plate can be increased or decreased by increasing or decreasing the outer diameter of the screw boss. The thickness can be changed.

  And in this invention, in order to suppress external appearance sink, the board thickness of a boss | hub is set to the comparatively thin specification which becomes the thickness of 1/2 to 1/3 with respect to the board thickness of the general part of a resin molded product. ing. When the plate thickness of the screwing boss exceeds 1/2 of the plate thickness of the general part, for example, when the plate thickness of the screwing boss is set to 1.75 mm when the plate thickness of the general part is 2.3 mm In this case, sink marks are likely to occur on the surface of the resin molded product, and when the plate thickness of the screw boss is less than 1/3 of the plate thickness of the general part, the strength of the screw boss is reduced and impact is reduced. This is because the screw fixing boss is likely to be damaged. Furthermore, setting the plate thickness of the screw-stop boss to be thin reduces the rigidity contrary to preventing the appearance sink, but in order to compensate for this, a reinforcing rib is appropriately provided on the outer peripheral surface of the screw-stop boss. It is provided at pitch intervals. In addition, the outer diameter of the screw-fixing boss including the reinforcing rib should satisfy the relationship of outer diameter (mm) ≧ (inner diameter × 2 + 0.5) (mm) with the inner diameter of the screw-fixing boss. . Furthermore, the width dimension of the reinforcing rib is preferably set to 1/2 to 1/3 of the plate thickness of the general part. The number of the reinforcing ribs to be installed is preferably set to an even number such as six or eight.

  As is apparent from the above configuration, the screw boss erected at a predetermined position on the back surface of the resin molded product has a plate thickness in the range of 1/2 to 1/3 of the plate thickness of the general portion of the resin molded product. Because it has been set inside and the plate thickness has been reduced, molding defects such as sink marks do not occur on the surface of the resin molded product, a good appearance can be obtained, and the rigidity has been reduced due to the thin wall. Since the reinforcing ribs are integrated with the outer peripheral surface of the boss, the strength of the screw-stop boss can be maintained firmly. Also, since the base is not integrated with the base of the screw-stop boss, the mold cost of the molding die Can also be kept inexpensive.

  As described above, the resin-molded product fixing structure according to the present invention fixes the resin-molded product to an appropriate position of the mating part via a screw-fixing boss provided upright at a predetermined position on the back surface of the resin-molded product. Resin molded product fixing structure, adjusting the plate thickness of the screw-fixing boss to 1/2 to 1/3 of the thickness of the general part of the resin molded product, preventing the appearance sink, The structure is such that the rigidity of the thin-walled screw boss is strengthened by the reinforcing rib on the outer peripheral surface. Therefore, the screw-fixing boss can eliminate the pedestal that requires the slide core, so it can be molded with an inexpensive mold, and the thickness of the screw-fixing boss can be reduced to prevent the appearance of sink marks, and Since the strength is ensured by the reinforcing ribs on the outer peripheral surface of the screw-fixing boss, the strength of the screw mounting portion can be enhanced. As described above, according to the present invention, the appearance of the resin molded product can be maintained satisfactorily, the strength of the screw-fixing boss can be strengthened, and various effects can be produced at low cost.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a resin molded product fixing structure according to the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the gist of the present invention is as described in the claims, and the contents of the embodiments described below are merely examples of the present invention.

  1 to 7 show an embodiment of the present invention. FIG. 1 is a front view showing a door trim having a door pocket fixed by applying the present invention. FIGS. 2 and 3 are objects to which the present invention is applied. FIG. 4 is a perspective view showing a screw fixing boss provided in the door pocket to which the present invention is applied, FIG. 5 is a plan view of the screw fixing boss, FIG. FIG. 7 is a plan view showing a modification of the screw-fixing boss used in the resin molded product fixing structure according to the present invention.

  FIG. 1 shows a door trim 10 as an interior part mounted on the indoor surface side of a door panel (not shown), and a door pocket 30 capable of accommodating equipment is fixed by screws with a lower side of a door trim main body 20 serving as a base. Various functional parts are mounted on the door trim main body 20, but the fixing structure of the door pocket 30 is a main part, and thus the description regarding the functional parts is omitted here. As shown in FIGS. 2 and 3, the door pocket 30 includes a pocket opening 31, and clip seats 32 are formed at three locations on the lower edge side of the door pocket 30 to be fixed to the door trim body 20. Screw fixing bosses 33 for fixing with screws to the door trim main body 20 are provided at a plurality of locations on both sides of the door pocket 30.

  By the way, the present invention has an ideal strength that does not cause any appearance sink on the product surface side of the screw fixing boss 33 and does not easily break even if the screw is firmly tightened and fixed. In addition, the present invention is characterized by providing a door pocket 30 fixing structure that does not require a separate slide core at the time of molding, can reduce mold costs, and can be implemented at low cost.

  That is, as shown in FIGS. 4 and 5, the plate thickness of the screw fixing boss 33 is 1/2 to 1/3 of the plate thickness of the general portion with reference to the plate thickness of the general portion of the door pocket 30. By setting the thickness within the range and preventing thinning of the appearance by making it relatively thin, the rigidity is reduced by reinforcing ribs 34 provided at eight locations on the outer peripheral surface of the screwing boss 33. A configuration with ideal strength is adopted. In this embodiment, as shown in FIG. 5, the inner diameter d1 of the screwing boss 33 is predetermined to 3.5 mm, and the outer diameter d2 of the screwing boss 33 is set to 6.5 mm. . Therefore, when the plate thickness d3 of the screwing boss 33 is adjusted to 1.5 mm and the plate thickness of the general part is set to 3.0 mm, the plate thickness of the screwing boss 33 is 1 / th of the plate thickness of the general part. 2 is set. Further, the reinforcing ribs 34 provided on the outer peripheral surface of the screwing boss 33 are provided at eight positions with equal pitch intervals, and the length dimension d4 is set to 0.5 mm. Further, the outer diameter d5 of the screwing boss 33 including the reinforcing rib 34 is between the outer diameter d5 (mm) ≧ (inner diameter d1 × 2 + 0.5) (mm) between the inner diameter d1 of the screwing boss 33. A relationship should be established. Furthermore, it is preferable that the width dimension d6 of the reinforcing rib 34 is set to 1/2 to 1/3 of the plate thickness of the general portion.

  As described above, the reason for setting the screw fixing boss 33 according to the present invention to 1/2 to 1/3 of the thickness of the general part is that the thickness exceeds 1/2 of the thickness of the general part. This is because sinking is likely to occur on the outer surface, resulting in poor appearance. Conversely, when the thickness is set to be less than 1/3 of the plate thickness of the general part, an appropriate strength cannot be ensured.

  Thus, in the fixing structure of the door pocket 30 according to the present invention, the screw fixing boss 33 has a structure in which the plate thickness is reduced and the reinforcing rib 34 is integrated on the outer peripheral surface. No. 33 can secure the necessary rigidity even though the plate thickness is thin, while maintaining the strength of the screw tightening part firmly, without causing any sink marks on the external surface, ensuring a beautiful appearance. it can. Further, since it is not necessary to integrate a pedestal or the like with the base portion of the screw-fixing boss 33, it is possible to cope with an inexpensive mold structure, so that the cost of the mold is not increased and the cost is not increased.

  6 and 7 show a modified example of the present invention. In the modified example shown in FIG. 6, the inner diameter d1 and the outer diameter d2 of the screwing boss 33 are the same as those in the above-described embodiment. This is a modified example in which the number of reinforcing ribs 34 formed on the outer peripheral surface of 33 is reduced to six, and thus, when the door pocket 30 is removed from the molding die after molding, the releasability is improved. The workability in the work can be improved and the number of electric discharge machining steps for the molding die can be reduced. Next, FIG. 7 shows a modification in which the plate thickness d3 of the screw-stop boss 33 is reduced to 1.15 mm. In this case, the plate thickness of the general portion of the door pocket 30 is set to 2.3 mm, and vice versa. Further, the length d4 of the reinforcing rib 34 is changed to 0.85 mm. Therefore, in this modified example, since the plate thickness of the screwing boss 33 is reduced, the fear of sinking is further alleviated.

  The embodiment described above is applied to the fixing structure of the door pocket 30 that is fixed to the lower surface of the door trim body 20 with screws. Is not limited.

It is a front view which shows the door trim which has a door pocket to which this invention is applied. It is a front view which shows the door pocket which is the application object of the fixing structure of the resin molded product which concerns on this invention. It is a rear view which shows the door pocket which is the application object of the fixing structure of the resin molded product which concerns on this invention. It is a perspective view of the boss for screwing provided in the door pocket shown in FIG. It is a top view of the boss | hub for screw fixing provided in the door pocket shown in FIG. It is a top view which shows the modification of the boss | hub for screw fixing used for the fixing structure of the resin molded product which concerns on this invention. It is a top view which shows the modification of the boss | hub for screw fixing used for the fixing structure of the resin molded product which concerns on this invention. It is a rear view which shows the conventional door pocket. It is a perspective view which shows the boss | hub for screw fixing provided in the conventional door pocket. It is a top view which shows the conventional boss | hub for screw fixing.

Explanation of symbols

10 Door Trim 20 Door Trim Body 30 Door Pocket 31 Pocket Opening 32 Clip Seat 33 Boss for Screw Fixing 34 Reinforcement Rib

Claims (3)

A resin-molded product (30) fixing structure for fixing a resin-molded product (30) molded into a required shape to a predetermined position of a counterpart component (20), and a predetermined position on the back surface of the resin-molded product (30) The screw fixing boss (33) is erected to position the resin molded product (30) at a predetermined position on the surface of the mating component (20), and then the screw is molded from the back side of the mounting hole of the mating component (20). In the fixing structure of the resin molded product (30) for fixing the resin molded product (30) by fastening and fixing in the screw fixing boss (33) of the product (30),
The screw fixing boss (33) employs a thin boss structure adjusted within a range of ½ to ３ of the plate thickness of the general part of the resin molded product (30). A structure for fixing a resin molded product, wherein reinforcing ribs (34) for compensating for a decrease in rigidity due to thin wall are integrated with the outer peripheral surface of the boss (33).   The outer diameter (d5) of the screwing boss (33) including the reinforcing rib (34) is between the outer diameter (d5) (mm) ≧ ( 2. The structure for fixing a resin molded product according to claim 1, wherein a relationship of inner diameter (d1) × 2 + 0.5) (mm) is established.   The width structure of the said reinforcing rib (34) is set to 1 / 2-1 / 3 of the plate | board thickness of a general part, The fixing structure of the resin molded product of Claim 1 or 2 characterized by the above-mentioned.

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