JP4482439B2 - Plastic molded product - Google Patents

Description

  The present invention relates to an improvement of a resin molded product having a mounting seat and having a large number of voids formed therein.

In Patent Document 1, a thermoplastic resin containing fibers is injected and filled into a cavity in a state where a fixed mold having a recess formed on a molding surface and a movable mold incorporating a slide mold are closed, and this thermoplastic resin containing fibers While the resin is solidified in the cavity, the slide mold is retracted in the movable mold to enlarge the cavity volume, and the fiber-containing thermoplastic resin is recovered by the elastic restoring force (spring back phenomenon) of the fiber compressed by the resin pressure. Is expanded to obtain a resin molded product in which convex portions are integrally projected on the molded product body and a large number of voids are formed inside the molded product body.
Japanese Patent Laid-Open No. 11-179751 (pages 3 and 7, FIG. 1)

  However, in the resin molded product as described above, since the volume of the entire cavity is expanded to expand the fiber-containing thermoplastic resin, a part of the fiber-containing thermoplastic resin flows into the enlarged cavity from the concave portion of the molding surface. As a result, sagging occurs due to insufficient resin on the front end surface of the convex portion formed by the concave portion of the resin molded product. As shown in FIG. 7, when such a phenomenon occurs in the mounting seat c for mounting the lifting rail of the window regulator integrally protruding to the door inner panel body b of the door inner panel a of the automobile, the lifting rail is This is a very serious problem because it cannot be accurately attached to the mounting seat c. In FIG. 7, d is a mounting surface at the tip of the mounting seat c, and indicates that the mounting surface d is tapered and the surface drip occurs on the mounting surface d. e is a screw insertion hole penetratingly formed in the mounting seat c, and f is a reinforcing rib integrally formed radially around the outer periphery of the mounting seat c. A is a void.

  This invention is made | formed in view of this point, The place made into the objective is to provide the resin molded product which does not produce surface sagging in the attachment surface of an attachment seat.

  In order to achieve the above object, the present invention is characterized in that the thermoplastic resin containing fibers does not flow out from the concave portion of the mold corresponding to the mounting seat during molding.

Specifically, the present invention is directed to a resin molded product in which a mounting seat having a mounting surface to which a component is attached at its tip is integrally projected on one surface of a molded product body. Took.

That is, according to the first aspect of the present invention, in the vicinity of the outer periphery of the mounting seat of the molded product body, a thin-walled portion that is thinner than other molded product body portions is integrally formed, and the thin-walled portion is formed on the mounting seat. In the process of solidifying the fiber-containing thermoplastic resin injected and filled into the cavity of the mold, the molded product main body, which is integrally continuous with the base end and excluding the mounting seat and the portion corresponding to the vicinity of the outer periphery of the mounting seat, The cavity volume on the molded product main body side excluding the mounting seat and the portion corresponding to the outer periphery of the mounting seat is expanded to the one surface side of the molded product main body, and the fiber-containing thermoplastic resin is expanded by the elastic restoring force of the fiber. a large number of voids formed therein by said mounting seat, molded article body corresponding to seat peripheral region with seat with said mounting及Vito is a cavity corresponding to the mounting seats and the attachment seat peripheral region at the time of molding the cavity without increasing the volume To regulate the outflow of fiber-containing thermoplastic resin into Luo said enlarged cavity, characterized that you have formed a hard solid with no air gap.

The invention according to claim 2 is characterized in that, in the invention according to claim 1 , a recess is formed in the molded product body corresponding to the mounting surface of the mounting seat and / or the base end of the mounting seat. To do.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a convex portion is formed near the outer periphery of the mounting seat.

According to the first aspect of the present invention, a large number of voids are formed by the elastic restoring force of the fiber compressed by the resin pressure inside the molded product main body excluding the portion corresponding to the mounting seat and the vicinity of the outer periphery of the mounting seat. Thus, the weight of the molded product can be reduced. On the other hand, does not expand the cavity volume corresponding to the mounting seats and the attachment seat peripheral region, the mounting seat, the molded article body corresponding to seat peripheral region with seat with said mounting及Bito the outflow of fiber-filled thermoplastic resin It is possible to secure the mounting strength by making the solid solid without any gaps. Also, since the cavity volume corresponding to the vicinity of the outer periphery of the mounting seat is not enlarged, the outflow of the thermoplastic resin containing fibers from the cavity corresponding to the inner mounting seat to the enlarged cavity is restricted, and the mounting surface of the mounting seat Therefore, it is possible to improve the mounting accuracy of the parts.

In addition , according to the first aspect of the present invention, the thin wall portion in the vicinity of the outer periphery of the mounting seat is cooled and solidified faster than other molded product main body portions , so that the enlarged cavity from the cavity corresponding to the mounting seat The partial outflow of the thermoplastic resin containing fibers into the hood is further restricted, and the mounting surface accuracy of the mounting seat can be further improved.

According to the invention which concerns on Claim 2 , the recessed part formed in the molded article main body corresponding to the attachment surface of a mounting seat and / or the base end of a mounting seat of the thermoplastic resin containing the fiber in the cavity corresponding to a mounting seat The solidification by cooling can be accelerated, and the mounting surface accuracy of the mounting seat can be further increased.

According to the invention of claim 3 , the fiber-containing thermoplastic resin flows out from the cavity corresponding to the convex portion of the resin molded product (molded surface concave portion) into the enlarged cavity, and the fiber seated thermoplastic resin flows out to the mounting seat. Since it is difficult to affect, the mounting surface accuracy of the mounting seat can be further improved, and the vicinity of the outer periphery of the mounting seat can be reinforced by the convex portion.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 3 is a perspective view of a resin door inner panel (door module) 1 constituting a part of a side door of an automobile as a resin molded product according to Embodiment 1 of the present invention as viewed from the vehicle interior side. The door inner panel 1 includes a door inner panel main body 3 as a molded product main body, and four cylindrical mounting seats 5 having screw insertion holes 5a are provided on a surface of the door inner panel main body 3 on the vehicle interior side. The screw insertion hole 5a penetrates through the door inner panel body 3, and a lifting rail as a part of a window regulator that raises and lowers the window glass by inserting a screw into the screw insertion hole 5a. (Not shown) is attached to the four attachment seats 5.

  A pulling hole having a screw insertion hole 7a into which a tapping screw is screwed on the outer surface of the door inner panel body 3 corresponding to the space between the two upper and lower mounting seats 5 on the right side in FIG. Four handle mounting bosses 7 are protruded integrally at the left and right at equal intervals.

  In FIG. 3, a circular flower pot-shaped speaker housing portion 9 is integrally projected on the outer surface of the door inner panel body 3 corresponding to the lower left corner in FIG. 3, and the door inner panel body 3 corresponding to the speaker housing portion 9 An annular flange portion 11 is integrally projected on the surface on the vehicle interior side, and a speaker mounting boss 13 having a screw insertion hole 13a into which a tapping screw is screwed into the flange portion 11 has a circumference of 4 or the like. One piece is integrally formed at a position to be divided.

  As shown in FIG. 4, a seal surface portion 15 is integrally formed on the outer peripheral edge portion of the vehicle inner surface of the door inner panel body 3 over the entire circumference, and the seal surface portion 15 has a U-shaped cross section. The seal groove 15a is recessed over the entire circumference. A seal material is provided in the seal groove 15a to ensure a seal with the door outer panel. In FIG. 3, reference numeral 17 denotes a ridge that protrudes toward the vehicle interior side of the door inner panel main body 3 in correspondence with the seal groove 15a.

  A plurality of screw insertion holes 18 are formed so as to penetrate the entire circumference of the door inner panel body 3 from the seal surface 15 of the door inner panel body 3 at predetermined intervals. Around the insertion hole 18, an annular convex portion 19 is projected to form a mounting portion 21. In FIG. 3, 22 is a motor mounting part for raising and lowering the window glass.

FIG. 1 is an enlarged view of the mounting seat 5 for mounting the lifting rail of the window regulator described above. The mounting surface 5b at the tip of the mounting seat 5 is formed as a flat surface. Further, a plurality of reinforcing ribs 25 are integrally formed radially in a region from the mounting seat 5 through the mounting seat outer peripheral portion 23 to the outer periphery thereof. Furthermore, a large number of gaps (indicated by X in FIG. 1A) are formed inside the door inner panel body 3 excluding the mounting seat 5 and the portion corresponding to the mounting seat outer peripheral vicinity 23. . In contrast, the mounting seat 5, the door inner panel body 3 corresponding to the mounting seat 5及arbitration with seat peripheral region 23 is a hard solid with no air gap A, the largest feature of this that this invention It is said. In particular, the mounting seat outer periphery vicinity portion (thin wall portion) 23 is formed thinner than the other door inner panel main body 3 portion , and the thin wall portion 23 is continuously connected to the base end of the mounting seat 5 . The door inner panel 1 having such a mounting seat 5 is formed as follows.

That is, as shown in FIG. 2, the shape of the mounting seat 5 is urged by a spring or the like so as to protrude toward the fixed die 27, the movable die 29 facing the fixed die 27, and the fixed die 27 side. A molding die 33 comprising a pressing block 31 having a recess 31a corresponding to the above is prepared, and a thermoplastic resin R containing fibers such as glass fibers is injected and filled from the injection machine into the cavity 35 with the molding die 33 closed. To do. At this time, the cavity interval W1 corresponding to the mounting seat outer periphery vicinity portion 23 is set to be narrower than the cavity interval W2 corresponding to the door inner panel body 3. Thereafter, in the process of fiber-containing thermoplastic resin R in the cavity 35 within the mold 33 is solidified, as shown in phantom in FIG. 2, a direction to expand the movable mold 29 is a cavity volume (car door inner panel body 3 Move back to the outer surface . That is, the movable mold 29 is slightly separated from the fixed mold 27, and the cavity volume on the door inner panel body 3 side excluding the mounting seat 5 and the portion corresponding to the mounting seat outer peripheral vicinity 23 is increased. The thermoplastic resin R containing fibers forms a surface layer as a skin layer (not shown) having a high resin density by quickly cooling the portion of the cavity 35 that contacts the molding surface due to the influence of mold temperature. On the other hand, the inner part of the fiber-containing thermoplastic resin R is hardly affected by the mold temperature and is in a gel state with high viscosity. Therefore, by expanding the cavity volume, the fiber that has been compressed with the resin pressure until then is released from the resin pressure and elastically restored. The elastic restoring force (spring back phenomenon) causes the fiber-containing thermoplastic resin R to expand. To do. As a result, the door inner panel 1 in which a large number of gaps A are formed inside the door inner panel body 3 excluding the mounting seat 5 and the portion corresponding to the mounting seat outer peripheral vicinity 31 is obtained. Can be achieved.

On the other hand, since the pressing block 31 does not move during the backward movement of the movable die 29, the cavity volume corresponding to the mounting seat 5 and the mounting seat outer peripheral portion 23 is not enlarged at the time of molding, and a thermoplastic resin containing fibers. The elastic restoration of the fibers in R is suppressed, and the thermoplastic resin R containing fibers does not flow out into the cavity 35 in which a part thereof is enlarged, and the formed mounting seat 5 , the mounting seat 5 , and the mounting seat outer peripheral portion 23 . The corresponding door inner panel main body 3 is a solid solid with no gap A caused by the outflow of the thermoplastic resin R containing fibers, and can secure the mounting strength and hang down the mounting surface 5b of the mounting seat 5. It is possible to improve the mounting accuracy of the lifting rail by finishing it flat.

  Further, since the cavity interval W1 corresponding to the mounting seat outer periphery vicinity portion 23 is set to be narrower than the cavity interval W2 corresponding to the outer door inner panel body 3 in the closed state of the mold 33, the mounting seat The outer peripheral vicinity 23 is cooled and solidified faster than other parts, and the partial outflow of the thermoplastic resin R containing fibers from the cavity 35 corresponding to the mounting seat 5 to the enlarged cavity 35 is reliably regulated. The surface accuracy of the mounting surface 5b of the mounting seat 5 can be further improved. That is, the thickness T1 of the formed mounting seat outer periphery vicinity 23 is the cavity interval W2 (the thickness of the door inner panel main body 3) corresponding to the door inner panel main body 3 excluding the mounting seat outer periphery vicinity 23 before expanding the cavity volume. It is set thinner than T2) (see FIG. 1A and FIG. 2).

FIG. 5 shows a mounting seat 5 of the door inner panel 1 according to the second embodiment. In the second embodiment, the annular recess 5d is formed in the door inner panel body 3 corresponding to the mounting surface 5b of the mounting seat 5 and the base end of the mounting seat 5, respectively, as in the first embodiment. Since it is comprised, the same code | symbol is attached | subjected to the same location and description is abbreviate | omitted. Therefore, in the second embodiment, in addition to being able to achieve the same operational effects as in the first embodiment, an annular formed on the door inner panel main body 3 corresponding to the base end of the mounting surface 5b and the mounting seat 5 With the recess 5d, solidification by cooling of the fiber-containing thermoplastic resin R in the cavity 35 corresponding to the mounting seat 5 can be accelerated, and the surface accuracy of the mounting surface 5b of the mounting seat 5 can be further increased. The recess 5d is not limited to an annular shape, and may be intermittent in the circumferential direction. Further, the recess 5 d may be formed only on either the mounting surface 5 b or the door inner panel body 3 corresponding to the base end of the mounting seat 5 .

  FIG. 6 shows a mounting seat 5 of the door inner panel 1 according to the third embodiment. In the third embodiment, except that an annular convex portion 23a is formed in the mounting seat outer periphery vicinity portion 23, it is configured in the same manner as in the first embodiment. The description is omitted. Therefore, in the third embodiment, the same function and effect as in the first embodiment can be achieved. In addition, since the solidification by cooling of the fiber-containing thermoplastic resin R in the cavity 35 corresponding to the convex portion 23a is faster than the vicinity of the outer periphery corresponding to the convex portion 23a, the convex portion 23a becomes a solid, and the mounting seat outer peripheral vicinity portion 23 Can be reinforced. The convex portion 23a is not limited to an annular shape, and may be intermittent in the circumferential direction.

  In each of the above embodiments, the gap A is formed inside the door inner panel main body 3 by utilizing the spring back phenomenon of the fiber. Even when the restoring force of the fiber in the back phenomenon is insufficient, the foaming force of the foaming agent is preferable because the restoring force of the fiber can be complemented and the void A can be reliably formed.

  Further, in each of the above embodiments, the case where the resin molded product is the door inner panel 1 of the automobile is shown, but it is a bonnet covering the engine room of the automobile, a ceiling material of the automobile, a cylinder head cover of the engine, or the like. Furthermore, it can be applied to panels other than automobiles.

  The present invention is useful for a resin molded product having a mounting seat and having a large number of voids formed therein.

The attachment seat of the door inner panel which concerns on Embodiment 1 is shown, (a) is sectional drawing in the II line | wire of FIG. 3, (b) is a top view of Fig.1 (a). It is a molding process figure which shows the state which injected and filled the thermoplastic resin containing a fiber in the cavity of a shaping | molding die. It is the perspective view which looked at the door inner panel which concerns on Embodiment 1 from the vehicle interior side. It is the enlarged view which looked at the X section of FIG. 3 from the vehicle outer side. FIG. 3 is a diagram corresponding to FIG. FIG. 3 is a diagram corresponding to FIG. It is a figure equivalent to FIG. 1 of a conventional example.

1 Door inner panel (resin molded product)
3 Door inner panel body (molded product body)
5 Mounting seat 5b Mounting surface 5c Anti-mounting surface 5d Recess 23 Mounting seat outer periphery vicinity portion (thin wall portion)
23a Convex part 33 Mold 35 Cavity A Cavity T1 Thickness T2 near the outer periphery of the mounting seat T2 Thickness of the door inner panel main body W1 Cavity interval corresponding to the outer peripheral portion of the mounting seat W2 Cavity spacing corresponding to the door inner panel main body

Claims (3)

A resin molded product in which a mounting seat having a mounting surface on which a component is mounted is projected integrally on one surface of the molded product body,
In the vicinity of the outer periphery of the mounting seat of the molded product body, a thin-walled portion that is thinner than other molded product body parts is integrally molded,
The thin-walled portion is integrally connected to the mounting seat base end,
The molded product main body excluding the mounting seat and the portion corresponding to the vicinity of the outer periphery of the mounting seat has a structure in the vicinity of the outer periphery of the mounting seat and the mounting seat in the process of solidifying the fiber-filled thermoplastic resin injected into the cavity of the mold. The cavity volume on the molded product main body side excluding the portion corresponding to the part is expanded to the one surface side of the molded product main body, and the thermoplastic resin containing fibers is expanded by the elastic restoring force of the fibers so that a large number of voids are formed inside. Formed,
Said mounting seat, molded article body corresponding to seat peripheral region with seat with said mounting及Vito from the cavity above expanded without enlarging the cavity volume corresponding to the mounting seats and the attachment seat peripheral region at the time of molding to regulate the outflow of fiber-containing thermoplastic resin into the cavity, a resin molded article which is characterized that you have been formed to a rigid void-free solid. In the resin molded product according to claim 1 ,
A molded resin body corresponding to the mounting surface of the mounting seat and / or the base end of the mounting seat is formed with a concave portion. In the resin molded product according to claim 1 or 2 ,
A resin molded product characterized in that a convex portion is formed in the vicinity of the outer periphery of the mounting seat.

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