JP2008074009A - Resin molded article which has shock absorption function, and its molding process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin molded article having the shock absorption function and its molding process which allow a recessed ditch imparting a shock absorption function to be freely set on shaping regardless of a set place of an ejector pin, a processing cost of the ejector pin to be reduced, and also demold operation to be smoothly carried out. <P>SOLUTION: The molding process avoids the dividing of the recessed ditch 41 to secure an excellent shock absorption function by providing the recessed ditch 41 and a circular recessed part 42A which can contain the tip end 64a of the ejector pin 64 with a communication structure if both are intervened so as to allow the recessed ditch 41 to be freely set even if the abutting part of this ejector pin 64 is present anywhere when being pushed up by a plurality of ejector pins 64 after an armless core 40 is molded by a molding die 60 since the back face of the armless core 40 is formed with the plural row of the recessed ditch 41 extending along a longitudinal direction of a vehicle to impart the shock absorption function. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin molded product having an impact absorbing function and a molding method thereof, and more particularly to a resin molded product provided with a concave groove serving as a base point of buckling deformation when an impact is applied from the outside, and an ejector pin Resin molding with shock absorbing function that can freely set the groove in the abutting part, can arbitrarily set the groove for shock absorption at the required place, and can reduce the processing cost of the molding die Product and its molding method.

  8 and 9 show an armrest 1 installed in a vehicle and rested by an occupant on an elbow, FIG. 8 is a perspective view, FIG. 9 is a sectional view, and the armrest 1 is a surface of an armrest core 2 More specifically, the armrest core material 2 is formed by injection-molding or press-molding a general-purpose thermoplastic resin such as polypropylene resin, polyethylene resin, or ABS resin. The armrest skin 3 can be made of a synthetic resin sheet or fabric sheet with excellent surface appearance and feel. If desired, a cushion layer such as urethane foam can be used as the armrest core 2 and the armrest skin. 3 may be inserted. As the armrest skin 3, a thick resin molded body can be used by injection molding an elastomer resin.

  By the way, the armrest 1 employs a configuration that reduces the impact load by buckling deformation of the armrest core material 2 in the armrest 1 when the occupant's body touches in the direction of arrow F in FIG. As shown in FIGS. 9 and 10, a plurality of rows of grooves 4 extending in the longitudinal direction are formed in the armrest core material 2, and the armrest 1 in the armrest 1 is subjected to a side collision with the groove 4 as a base point. An impact absorbing function is obtained by buckling deformation of the core material 2. A conventional configuration of the armrest 1 having an impact absorbing function is disclosed in Patent Document 1.

JP 9-277863 A

  As described above, in order to provide the armrest 1 with an impact absorbing function, a plurality of rows of concave grooves 4 have been formed in the armrest core material 2. However, in the mold for molding the armrest core material 2, An ejector pin 5 (not shown in FIG. 10) that pushes up the armrest core material 2 in the demolding direction is set, and a plurality of push-up points indicated by a in FIG. Then, in consideration of the shock absorbing performance to be applied to the armrest 1, when newly adding the concave groove 4, for example, when passing the push-up points a of the ejector pins 5 set at a plurality of locations, interference is caused. In order to avoid this, as shown in FIG. 11, the groove 4 must be divided in the middle, and the base point of buckling deformation will be divided. Therefore, it has been pointed out that the shock absorbing function is lowered.

  Further, when the concave groove 4 is penetrated without being divided, as shown in FIG. 12, it is necessary to form a rib 5a fitted to the concave groove 4 at the tip portion of the ejector pin 5, and in such a case, the ejector pin 5 is expensive, and the fitting accuracy is required between the groove 4 and the rib 5a of the ejector pin 5, but a gap is generated between the two due to the anti-rotation processing and assembly accuracy of the ejector pin 5. Since the groove 4 is not continuous because it is easy, a problem has been pointed out that an impact absorbing function due to buckling deformation cannot be expected.

  The present invention has been made in view of such circumstances, and is a resin molded product having an impact absorbing function represented by an armrest core material in an armrest and a molding method thereof, and can freely impact even at an ejector pin setting location. A resin molded product having an impact absorbing function that can pass through a ditch for absorption, can maintain a good impact absorbing function, can reduce the processing cost of a molding die, and can perform a demolding operation smoothly, and It aims at providing the shaping | molding method.

  In order to solve the above problems, the present invention is a resin molded product that is molded into a required shape by injecting and filling molten resin into a product cavity formed by clamping a cavity mold and a core mold. In a resin molded product having an impact absorbing function in which a plurality of concave grooves that are the base points of buckling deformation are formed when an impact is applied from the outside, the resin molded product has a core-type ejector pin after molding, A push-up point set at multiple locations on the bottom surface of the resin molded product is pushed up, and a circular recess that accommodates the tip of this ejector pin is formed in communication with the groove at the location where the push-up point interferes with the groove. It is characterized by being.

  Further, according to the method of the present invention, a molten resin is injected and filled into a product cavity formed by clamping a cavity mold and a core mold to mold a resin molded product into a required shape. In a molding method of a resin molded product for molding a resin molded product having an impact absorbing function by pushing up an internal ejector pin, at the portion where the tip of the ejector pin interferes with the concave groove of the resin molded product, the tip of the ejector pin The resin-molded product is pushed up by an ejector pin set at an arbitrary position without dividing the concave groove by communicating the circular concave portion and the concave groove.

  Here, as the resin molded product having an impact absorbing function, the armrest core material in the armrest attached to the door trim and the door trim core material in the door trim in which the armrest is integrated are applicable. The injection molding method and the mold press molding method This is a molded product that is molded by using a plurality of rows of concave grooves that act as a base point for buckling deformation when an impact is applied from the outside, such as during a side collision. It can be applied to all resin molded products pushed up by the above. The mold is composed of a cavity mold and a core mold, and a plurality of ejector pins are provided inside the core mold, and a convex surface corresponding to the concave groove formed in the resin molded product is formed on the core mold surface. A strip is provided, and a circular concave portion that accommodates the tip portion of the ejector pin is set to communicate with the concave groove at a portion where the concave groove and the ejector pin setting portion interfere with each other.

  As is clear from the above configuration, even if the concave groove and the ejector pin setting location interfere with each other, the concave groove is not divided, so that the shock absorbing function by dividing the concave groove, that is, by dividing the base point of buckling deformation. There is no risk of lowering. Furthermore, it is only necessary to house the tip of the ejector pin in a circular recess that communicates with the concave groove and perform the push-up operation. This eliminates the trouble of forming a rib that fits into the concave groove on the ejector pin and prevents rotation of the ejector pin. There is no fitting error between the ejector pin and the resin molded product which occurs due to processing and assembly accuracy.

  As described above, in the resin molded product having an impact absorbing function and the molding method according to the present invention, when an impact load is applied to the resin molded product, a concave groove serving as a base point of buckling is provided at appropriate positions. In addition, at the part where the push-up point of the ejector pin interferes with the concave groove, a circular concave portion that accommodates the tip of the ejector pin is formed so as to communicate with the concave groove, and the tip of the ejector pin is accommodated in the circular concave portion. Since it is configured to push up the resin molded product, the concave groove is not divided in the middle, that is, the base point of buckling deformation is not divided, and the necessary shock absorbing function is provided. Since the ejector pin is housed in the circular recess and the resin molded product is pushed up, there is no need to rib the tip of the ejector pin, and the fitting accuracy between the rib and the recessed groove is also required. Since it is not, with mold processing can also be simplified, it is possible to reduce the processing cost of the mold, moreover has the effect that the demolding operation can be smoothly performed.

  Hereinafter, embodiments of a resin molded product having an impact absorbing function and a molding method thereof according to the present invention will be described in detail with reference to the accompanying drawings. Note that the gist of the present invention is as described in the scope of claims, and the contents of the embodiments described below are merely examples of the present invention.

  FIG. 1 to FIG. 7 show an embodiment of the present invention. FIG. 1 is a perspective view showing a door trim in which a resin molded body having an impact absorbing function according to the present invention is applied to an armrest core material, and FIG. FIG. 3 is a plan view of the armrest core material, FIG. 4 is an explanatory diagram illustrating a molding process of the armrest core material, and FIG. 5 is a resin molded material. 6 is an explanatory view showing the relationship between the product and the ejector pin, FIG. 6 is an explanatory view showing the relationship between the recessed groove and the circular recessed portion in the resin molded product, and FIG. 7 is a view showing the relationship between the recessed groove and the circular recessed portion in the modification according to the present invention. It is explanatory drawing.

  In FIG. 1, an automobile door trim 10 is provided with an armrest 30 on which a rider can rest on an elbow at a predetermined position on the surface of a door trim main body 20 serving as a base. More specifically, in this embodiment, the door trim main body 20 is formed by molding a polypropylene resin or a polypropylene resin material appropriately mixed with a filler by a mold press molding method into a required shape, and a fabric sheet is formed on the upper side of the armrest 30. In addition to improving the feel and appearance performance, a door pocket opening 22 capable of accommodating equipment is opened below the armrest 30 and a pocket back (not shown) is provided on the back side thereof. A cover is attached. A speaker grille 23 is provided on the front side of the pocket opening 22 integrally with the door trim body 20 or separately.

  As shown in FIGS. 2 and 3, the armrest 30 is configured by enveloping an armrest skin 50 on the surface of the armrest core member 40. In this embodiment, the armrest skin 50 has a cushioning property on the back surface. A cushion layer 51 made of a polyurethane foam to be applied is laminated. The armrest core member 40 is a resin molded product. In particular, the armrest core member 40 is applied to the armrest 30 that is attached to the approximate center of the surface of the door trim body 20 so that the occupant touches the armrest 30, particularly the armrest 30 of the door trim 10 when a side collision occurs. Since it is easy, the shock absorbing function is given to the armrest core member 40. More specifically, the armrest core member 40 is formed into a required shape by injection molding a general-purpose thermoplastic resin such as a polypropylene resin, a polyethylene resin, an ABS resin, and the like. In order to ensure good shock absorption due to buckling deformation, a plurality of rows of concave grooves 41 are provided along the longitudinal direction of the vehicle. Furthermore, as shown in FIG. 3, the armrest core member 40 to which the structure of the resin molded product according to the present invention is applied is formed with a plurality of rows of concave grooves 41 extending along the longitudinal direction of the vehicle, as shown in FIG. It can easily be buckled and deformed with reference to 41, and has excellent characteristics of shock absorption function, and ejector pin push-up points 42 are set at predetermined multiple locations over the entire back surface. Thus, the concave groove 41 is added or changed in shape, and a circular concave portion 42A is formed at a location where the concave groove 41 and the push-up point 42 interfere. Note that the armrest core member 40 is formed with a locking claw 43 to be attached to the door trim main body 20 at an appropriate position. In order to form the locking claw 43, the slide core 44 shown by a dotted line in FIG. Placed in the mold.

  Incidentally, the present invention is characterized in that the concave groove 41 and the circular concave portion 42A are formed in communication. That is, as shown in FIGS. 4 and 5, in order to mold the armrest core member 40, the molding die 60 shown in FIG. 4 is clamped, and the cavity mold 61 and the core mold 62 are clamped. 4, molten resin is injected and filled into a product cavity C formed between both molds 61 and 62 through a resin passage such as a gate (not shown) to form the armrest core 40 into a required shape. However, in this case, a plurality of grooves 41 are formed corresponding to the ridges 63 formed on the mold surface of the core mold 62, and the ejector is used to push up upward simultaneously with the mold opening after the armrest core member 40 is molded. As shown in FIG. 5, the tip 64a of the ejector pin 64 at the location where the pin 64 is set and the concave groove 41 and the push-up point 42 interfere is accommodated in the circular concave portion 42A. Therefore, as shown in FIG. 6, when setting the groove 41 for imparting an impact absorbing function to the armrest core member 40, the ejector pin 64 when performing the demolding operation after forming the armrest core member 40 is the groove 41. Since the groove 41 is accommodated in the circular recess 42 </ b> A that communicates with the groove and the groove 41 is not divided, the base of buckling deformation is not divided, and a good shock absorbing function can be obtained. The tip does not need to be ribbed, and the fitting accuracy between the resin molded product and the ejector pin 64 is not troublesome, so that the mold structure cost can be simplified and the mold removal operation can be performed smoothly. Further, FIG. 7 shows that the setting position of the circular recess 42A for accommodating the ejector pin 64 is provided at a position deviated from the width center line of the groove 41 to either one of the left and right sides. Is optional.

  In the embodiment, the resin molded product having the shock absorbing function according to the present invention is applied to the armrest core material 40 of the armrest 30. However, if the resin molded product has the shock absorbing function, the door trim core material and the rear side trim core material are used. It can also be applied to itself, and can be applied to all types of resin molded products in which a concave groove having an impact absorbing function is formed and is pushed up by an ejector pin after molding.

It is a perspective view which shows the door trim equipped with the armrest which applied the resin molded product which concerns on this invention to the armrest core material. It is a partially broken perspective view which shows the armrest which applied the resin molded product which concerns on this invention to the armrest core material. It is the top view which looked at the armrest core material in the armrest shown in FIG. 2 from the back surface side. It is explanatory drawing which shows the outline | summary of the shaping die which shape | molds the armrest core material shown in FIG. It is explanatory drawing which shows the relationship between the ejector pin and the ditch | groove in the armrest core material shown in FIG. It is explanatory drawing which shows the relationship between the ditch | groove of the armrest core material which removed the ejector pin shown in FIG. 5, and a circular recessed part. It is a principal part perspective view which shows the modification of the armrest core material to which the resin molded product which has the impact absorption function which concerns on this invention is applied. It is a perspective view which shows the conventional armrest. It is explanatory drawing which shows the state at the time of the side collision in the conventional armrest. It is the top view which looked at the armrest core material in the conventional armrest from the back surface side. It is explanatory drawing which shows the division | segmentation state of the ditch | groove in the conventional armrest core material. It is explanatory drawing which shows the relationship between the ditch | groove in the conventional armrest core material, and the ejector pin which carried out the rib process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Door trim 20 Door trim main body 21 Centering sheet 22 Door pocket opening 23 Speaker grill 30 Armrest 40 Armrest core material 41 Groove 42 Push-up point 42A Circular recessed part 43 Locking claw 44 Slide core 50 Armrest skin 51 Cushion layer 60 Mold 61 Cavity mold 62 Core mold 63 Convex strip 64 Ejector pin 64a Tip

Claims (2)

A resin molded product (40) molded by injection molding with molten resin into a product cavity (C) formed by clamping a cavity mold (61) and a core mold (62). In the resin molded product (40) having an impact absorbing function in which a plurality of grooves (41) serving as a base point of buckling deformation are formed when an impact is applied from the outside,
After the molding of the resin molded product (40), the ejector pins (64) of the core mold (62) push up upward push points (42) set at a plurality of locations on the bottom surface of the resin molded product (40). A circular recess (42A) that accommodates the tip (64a) of the ejector pin (64) is formed in communication with the recess (41) at a portion where the push-up point (42) and the recess (41) interfere with each other. A resin molded product having an impact absorbing function characterized by The resin mold (40) is molded into a required shape by injecting and filling molten resin into a product cavity (C) formed by clamping the cavity mold (61) and the core mold (62). Thereafter, in the molding method of the resin molded product, the resin molded product (40) having an impact absorbing function is molded by pushing up the ejector pin (64) embedded in the core mold (62).
At a portion where the tip (64a) of the ejector pin (64) and the concave groove (41) of the resin molded product (40) interfere with each other, a circular recess (42A) for accommodating the tip (64a) of the ejector pin (64) An impact characterized in that the resin molded product (40) is pushed up by an ejector pin (64) set at an arbitrary position without dividing the concave groove (41) by communicating with the concave groove (41). A method for molding a resin molded product having an absorption function.

Images