JP4465262B2 - Plastic molded product - Google Patents

Description

  The present invention relates to an improvement in a resin molded product having a seal portion at the outer peripheral edge of a molded product body and having a large number of voids formed inside the molded product body.

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 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)

By the way, in the resin molded product as described above, for example, a resin door inner panel a of an automobile as shown in FIG. 7 will be described as an example. In the door inner panel a, the outer side of the door inner panel body b is arranged outside the vehicle. A seal portion c for joining the door outer panel is provided on the outer peripheral edge of the surface so as to protrude over the entire circumference. The seal portion c is formed with a seal groove e for applying the seal material C. For this reason, the portion corresponding to the seal portion c of the door inner panel a has an inner door corresponding to the amount of the seal portion c. It is formed thicker than the inner panel body b. Accordingly, the cooling speed of the seal portion c is slower than that of the door inner panel main body b. When the fiber-containing thermoplastic resin is expanded using the elastic restoring force (spring back phenomenon) of the fiber as described above, the seal portion c from the corresponding cavity section c to flow out fiber-containing thermoplastic resin outer peripheral edge portion of the seal portion c is inclined faces sagging in the relevant section is occurring. Thus, when surface sagging occurs in the seal part c, the surface accuracy of the sealing surface d to which the sealing material C is applied deteriorates, and when the sealing material C is applied to the sealing surface d, the sealing material C sags. Leaking outward from the outer peripheral edge of the seal surface d, the seal material C becomes insufficiently applied, the door outer panel cannot be attached to the seal surface d with high accuracy, and the bonding strength is adversely affected. In addition, rain water to enter immersion in the inside of the door inner panel a, or electrical equipment is wet, which is attach to the door inner panel a inner surface, there is a problem that rainwater or intrusion into the passenger compartment. In FIG. 7, A is a gap.

  This invention is made | formed in view of this point, The place made into the objective is to provide the resin molded product which a surface droop does not produce in the sealing surface of a seal part.

  In order to achieve the above object, the present invention is characterized in that the contact area between the fiber-containing thermoplastic resin and the mold is increased in the cavity corresponding to the seal portion.

Specifically, the present invention is premised on a resin molded product in which a seal portion having a seal groove is integrally projected on the outer peripheral edge portion of one surface of a molded product body, and a seal material is applied to the seal portion. The following solutions were taken.

That is, a first aspect of the present invention, the above-mentioned molded article Body, enlarged in the course of fiber-containing thermoplastic resin injected and filled in the mold cavity has solidified, the cavity volume corresponding to the molded article the body Then, a large number of voids are formed inside by expanding the thermoplastic resin containing fibers with the elastic restoring force of the fibers, and another seal groove is formed along the seal groove in the seal portion on the side of the seal groove. It is characterized by being recessed .

According to a second aspect of the invention, in the above premise, the above-mentioned molded article Body, in the course of fiber-containing thermoplastic resin injected and filled in the mold cavity has solidified, the cavity volume corresponding to the molded article the body A large number of voids are formed inside by expanding the thermoplastic resin containing fibers with the elastic restoring force of the fibers, and a plurality of bottomed seal holes are formed in the seal portion on the side of the seal groove. characterized in that it is recessed I along with the seal groove.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the molded product main body opposite to the seal portion has a recess formed along the seal groove. .

Invention according to claim 4, in the above premise, the above-mentioned molded article Body, in the course of fiber-containing thermoplastic resin injected and filled in the mold cavity has solidified, the cavity volume corresponding to the molded article the body A large number of voids are formed inside by expanding the thermoplastic resin containing fibers with the elastic restoring force of the fibers, and a concave portion is formed along the seal groove in the molded product main body opposite to the seal portion. It is characterized by being recessed.

According to the first aspect of the present invention, a large number of voids are formed inside the resin molded product main body due to the elastic restoring force of the fibers compressed by the resin pressure, thereby increasing the rigidity and weight of the resin molded product. Can be planned. On the other hand, by recessing the other of the sealing groove in the sealing portion of the sealing groove side I along with the seal groove, a contact area between the fiber-filled thermoplastic resin in the cavity corresponding to the sheet Lumpur portion and the mold As a result, the thermoplastic resin containing fibers in the cavity corresponding to the seal portion is cooled early. As a result, even if the thermoplastic resin containing the fiber expands due to the elastic restoring force (spring back phenomenon) of the fiber on the molded product main body side, the cooling of the corresponding part is proceeding from the seal part side. The resin spilling does not occur, and the sagging can be prevented. For this reason, the sealing surface becomes flat, and other members can be attached to the sealing surface with high accuracy, and the bonding strength can be improved.

According to the invention of claim 2, the recessed to Rukoto the seal hole with a bottom along the seal groove, the number contact area between the mold and the thermoplastic resin in the corresponding cavity seal portion, The same effect as that of the first aspect can be realized.

According to the third and fourth aspects of the invention, the concave portion of the molded product main body on the side opposite to the seal portion reduces the thickness of the portion, so that the cooling is accelerated and the solidification is accelerated, thereby improving the surface accuracy of the seal surface. Can do. In particular, in claim 3, an early cooling effect due to an increase in the contact area between the fiber-containing thermoplastic resin and the mold can be added, and the surface accuracy of the seal surface can be further improved.

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

  4 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 the door inner panel main body 3, and a window regulator ascending / descending rail (not shown) for raising and lowering the window glass by inserting a screw into the screw insertion hole 5a. Are attached to the four mounting 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 integrally projected on the left and right at equal intervals.

  In FIG. 4, a speaker pot 9 having a circular flower pot shape is integrally projected on the outer surface of the door inner panel main body 3 corresponding to the lower left corner of the door inner panel main body 3. An annular flange 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 on the mounting seat 11 has a circumference of 4 or the like. One piece is integrally formed at a position to be divided.

As shown in FIG. 5, a seal portion 15 is integrally projected on the outer peripheral edge portion of the vehicle outer surface of the door inner panel body 3 over the entire circumference. A seal material C (see FIG. 1A) is applied to the seal portion 15 to ensure a seal with the door outer panel.

  A plurality of screw insertion holes 18 are formed through the entire periphery of the door inner panel body 3 from the seal portion 15 at predetermined intervals. Around the insertion hole 18, an annular convex portion 19 is projected to form a mounting portion 21. In FIG. 4, 22 is a motor mounting part for raising and lowering the window glass.

FIG. 1A shows the above-described seal portion 15 in an enlarged manner. The seal portion 15 slightly protrudes to the outside of the door inner panel main body 3 and a seal groove 15b having a U-shaped cross section is formed along the outer peripheral edge of the door inner panel main body 3 at a substantially central portion in the width direction of the seal surface 15a. It is recessed over. Another seal groove 15c having a narrower width than the seal groove 15b is recessed along the seal groove 15b in the seal portions 15 on both sides in the width direction of the seal groove 15b. By forming the seal groove 15c, the upper Symbol seal portion 15 constitutes the Article 4 of the rib 15d along the seal groove 15b. Further, the seal portion 15 and the opposite side of the door inner panel body 3 (anti-seal surface 15e side) Ru Tei formed flat. Then, inside the upper Kido Ain'napaneru body 3, numerous voids A (indicated by × mark in FIG. 1 (a)) is formed. The door inner panel 1 having such a seal portion 15 is formed as follows.

That is, as shown in FIG. 1B, a forming die 27 including a fixed die 23 and a movable die 24 facing the fixed die 23 is prepared. On the molding surface of the fixed mold 23, convex strips 23a and 23b corresponding to the shapes of the seal groove 15b of the seal portion 15 and the seal grooves 15c on both sides thereof are formed. On the other hand, the molding surface of the movable die 24, the recess 24a corresponding to the shape of the upper Kido Ain'napaneru body 3 is formed. First, with the mold 27 closed, the cavity 25 is filled with a thermoplastic resin R containing fibers such as glass fibers from an injection machine. Thereafter, in the process in which the fiber-containing thermoplastic resin R is solidified in the cavity 25 of the mold 27, the movable mold 24 is moved backward in the direction in which the cavity volume is expanded, as indicated by the phantom line in FIG. That is, the movable mold 24 is slightly separated from the fixed mold 23. The thermoplastic resin R containing fibers constitutes a surface layer as a skin layer (not shown) having a high resin density by quickly cooling the portion of the cavity 25 in contact with 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 main body 3 is obtained, and the door inner panel 1 can be increased in rigidity and weight. The seal portion 15 to the outer peripheral edge portion on the surface of the exterior of the door inner panel body 3 is integrally projected over the entire periphery, the seal surface 15a of the seal 15, the seal groove 15b and its both sides a seal groove 15c of the narrow width is formed along the entire circumference. Thus, Article 4 of the ribs 15d are formed integrally in parallel over the entire circumference along the upper Symbol seal 15 on the sealing surface 15a side of the seal portion 15.

Therefore, the number area of contact with the forming surface of the fiber-containing thermoplastic resin R and the fixed die 23 in the cavity 25 corresponding to the seal portion 1 5, fiber-containing thermoplastic resin R in the cavity 25 corresponding to the seal portion 1 5 Is cooled early. Thus, from the cavity 25 to the fiber elastic restoring force of the door inner panel main body 3 side (spring back phenomenon) in fiber-containing thermoplastic resin R corresponds to the seal portion 1 5 also expands, the relevant section cooling progresses As a result, resin spillage due to the expansion does not occur, and surface sagging can be prevented. For this reason, the seal surface 15a becomes flat, the outer panel can be attached to the seal surface 15a with high accuracy, and the bonding strength can be improved.

FIG. 2A shows an enlarged view of the seal portion 15 of the second embodiment. In the second embodiment, in addition to a plurality of bottomed seal hole 15f on both sides of the sealing portion 15 of the seal groove 15b is recessed I along with the seal groove 15b, as in the first embodiment It is configured. Therefore, in the second embodiment, although the cooling rate on the side of the seal groove 15b is slightly slower at the time of molding than in the first embodiment, it is possible to achieve substantially the same operational effects as in the first embodiment.

FIG. 3 shows an enlarged view of the seal portion 15 of the third embodiment. In the third embodiment, the door inner panel body 3 (on the side of the anti-seal surface 15e ) opposite to the seal portion 15 has a substantially U-shaped recess (stolen portion) 15g along the seal groove 15b. It is recessed over. FIG. 3B is a view corresponding to FIG. 1B in the first embodiment. In FIG. 3B, the seal groove 15b is formed on the molding surface of the fixed mold 23 in accordance with the shape of the seal portion 15. The forming ridges 23a are formed, and the ridges 24b for forming the ridges (stolen portions) 15g are formed on the molding surface of the movable die 24 corresponding to the ridges 23a. The molding method is the same as in the first embodiment. Therefore, in the third embodiment, the opposite side of the door inner panel main body 3 and the sealing portion 15 (counter-sealing surface 15e side), the thickness by concave part 15g of the door inner panel body 3 except for the sealing portion 15 gap A thinner than the portion having the said part is fast cooling rate at the time of molding, when retracting the movable die 24, fiber-containing thermoplastic resin R of the cavity corresponding to the sheet Lumpur surface 15a is of the door inner panel body 3 It does not flow out towards. Therefore, also in Embodiment 3, the same operational effects as Embodiments 1 and 2 can be achieved.

FIG. 6 shows the door inner panel 1 in which ribs 15 h are integrally projected on the outer peripheral edge portion of the door inner panel main body 3 (on the side of the anti-seal surface 15 e ) opposite to the seal portion 15. In this door inner panel 1, the presence of the ribs 15 h increases the contact area between the fiber-containing thermoplastic resin in the cavity corresponding to the outer peripheral edge of the seal portion 15 including the ribs 15 h and the fiber-containing heat. Cooling of the plastic resin is accelerated and the outflow of the resin from the outer peripheral edge portion of the seal portion 15 is reduced, so that the sagging of the seal surface 15a at the location can be prevented.

In addition, in each said embodiment, although the seal groove 15b is dented over the perimeter along the outer-periphery edge part of the seal | sticker part 15, you may make it dented intermittently. Further, in the first embodiment, although the ribs 15d structures Article 4 the sealing portion 15 by respective recessed another seal groove 15c on both sides of the seal groove 15b, as further according to the third embodiment A concave portion (stolen portion) 15 g may be provided in the door inner panel main body 3 on the side opposite to the seal portion 15. In the second embodiment, a plurality of bottomed sealing holes 15f are recessed in the seal portion 15 on the side of the seal groove 15b. However, as in the third embodiment, the door inner panel main body on the opposite side to the seal portion 15 is provided. 3 ( on the side of the anti-seal surface 15e ) may be provided with a concave portion (stolen portion) 15g. By doing so, the recess (stolen part) 15g of the door inner panel body 3 (on the side of the anti-seal surface 15e ) on the opposite side of the seal part 15 reduces the thickness of the part, thereby further cooling and further solidifying faster. As a result, the effects of the first and second embodiments can be reliably achieved.

  Further, in each of the above-described embodiments, the gap A is formed inside the door inner panel body 3 by utilizing the spring back phenomenon of the fiber, but if the foaming agent is included in the fiber-containing thermoplastic resin R, the spring 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 automobile door inner panel 1 is shown. However, even if it is a hood covering the engine room of the automobile, a ceiling material of the automobile, a cylinder head cover of the engine, or the like. Moreover, it can be applied to panels other than automobiles.

  The present invention is useful for a resin molded product having a seal portion at the outer peripheral edge of the molded product body and having a large number of voids formed inside the molded product body.

(A) is sectional drawing in the II line | wire of FIG. 5, (b) is a shaping | molding process figure corresponding to FIG. 1 (a) which shows the state which injected and filled the thermoplastic resin containing a fiber in the cavity of a shaping | molding die. It is. . (A) is a figure equivalent to Drawing 1 (a) in Embodiment 2, and (b) is a top view of Drawing 2 (a). FIG. 1 (a) is a view corresponding to FIG. 1 (a) in Embodiment 3, and FIG. 3 (b) is a molding corresponding to FIG. 3 (a) showing a state in which a thermoplastic resin containing fibers is injected and filled into the cavity of the mold. It is process drawing. . 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. 4 from the vehicle outer side. The seal portion and the opposite side of the door inner panel body (counter sealing surface) is FIGS. 1 (a) corresponding view projecting from the ribs. It is a figure equivalent to Drawing 1 (a) of a conventional example.

1 Door inner panel (resin molded product)
3 Door inner panel body (resin molded body)
15 Seal portion 15a Seal surface 15b, c Seal groove 15d Rib 15e Anti-seal surface 15f Seal hole 15g Recessed portion (stolen portion)
23 Fixed mold 24 Movable mold 25 Cavity 27 Molding mold A Void R Fiber-containing thermoplastic resin

Claims (4)

Sealing portion having a sealing groove is integrally projected on an outer peripheral edge portion of one surface of the molded article body, a resin molded article for applying a sealant to the sealing portion,
The above molded article Body, in the course of fiber-containing thermoplastic resin injected and filled in the mold cavity is solidified, by a larger cavity volume that corresponds to the molded article the body of fibers the fiber-containing thermoplastic resin A large number of voids are formed inside by expanding with elastic restoring force,
The seal is the seal portion of the groove side, the resin molded article, characterized in that another seal groove is recessed I along with the seal groove. Sealing portion having a sealing groove is integrally projected on an outer peripheral edge portion of one surface of the molded article body, a resin molded article for applying a sealant to the sealing portion,
The above molded article Body, in the course of fiber-containing thermoplastic resin injected and filled in the mold cavity solidifies, by enlarging the cavity volume corresponding to the molded article the body of fibers the fiber-containing thermoplastic resin A large number of voids are formed inside by expanding with elastic restoring force,
The seal groove side of the the seal portion, the resin molded article seal hole with a bottom is characterized in that it is recessed me along the plurality the seal groove. In the resin molded product according to claim 1 or 2,
A resin molded product , wherein a concave portion is provided along the seal groove in the molded product main body opposite to the seal portion. Sealing portion having a sealing groove is integrally projected on an outer peripheral edge portion of one surface of the molded article body, a resin molded article for applying a sealant to the sealing portion,
The above molded article Body, in the course of fiber-containing thermoplastic resin injected and filled in the mold cavity solidifies, by enlarging the cavity volume corresponding to the molded article the body of fibers the fiber-containing thermoplastic resin A large number of voids are formed inside by expanding with elastic restoring force,
A resin molded product , wherein a concave portion is provided along the seal groove in the molded product main body opposite to the seal portion.

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