JP4710638B2 - Plastic molded product - Google Patents

Description

  The present invention relates to a resin molded product.

Conventionally, as a resin molded product in which a primary molded product is used as a core and a secondary molded portion is formed on the outer surface of the core, the one described in Patent Document 1 below is known. This is designed to be held at a position floating from the molding surface by providing a protrusion on the outer surface of the core. As for the dimension of the core, a certain clearance is provided between the molding surface and the tip of the protrusion in consideration of the dimensional variation of the primary molding. The reason for providing the clearance in this way is that the mold may not be closed when the clearance is set to zero and the core is finished with a large dimension.
JP 2005-7715 A

  However, since this product has a certain clearance, when the core is finished to a small size, there is a risk that burrs may occur due to the molten resin entering between the tip of the projection and the molding surface. is there. The present invention has been completed based on the above-described circumstances, and an object thereof is to suppress the occurrence of burrs between the tip of a protrusion and a molding surface.

請 Motomeko one aspect of the present invention, a primary molded article to the outer surface of the main body bus bar circuit is routed inside the plurality of protrusions is protruded, in a mold capable of opening and closing in the two directions perpendicular to each other It comprises a secondary molded part molded between the outer surface of the primary molded product held at a position floating through the projecting part and the molding surface of the mold, and the projecting part is formed by the primary molded product. Of the outer surface of the main body portion, two protrusions facing each other when facing the pair of molding surfaces facing each other at the time of mold closing in each direction are integrally formed to face each other in opposite directions, and both protrusions are The tip has a sharp shape and the tip is a deformable portion, and the distance between the pair of molding surfaces facing each other when each die is closed is L1, and the corresponding pair of protrusions in the primary molded product the overall height between the tips when the L2, larger than L2 is L1 In particular with the tip of the projections each pair is compressed is the deformable portion by being pressed by both the molding surface of the mating, the pair of protrusions is set so that, the mold is closed mold by the total height between the tip of the L1, having characterized in that after the secondary molding has a configuration in which the tip of the projecting portion on the outer surface of the secondary molded part is adapted to be exposed.

<Invention of Claim 1>
According to the invention of claim 1, when the molding die is closed, the deformable portion is compressed by the molding surface, and the clearance between the molding surface and the tip of the projection becomes zero. The occurrence of burrs is restricted by the molten resin entering between the molding surface and the molding surface.

In addition, since the tip of the protrusion has a sharp shape and is a deformable part, it is not necessary to provide the protrusion and the deformable part separately, and the structure can be simplified.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 2, the resin molded product 1 according to the first embodiment includes a primary molded product (hereinafter simply referred to as a core) 4 indicated by a broken line and a plurality of protrusions 8 provided on the outer surface of the core 4. And a secondary molding part 5 indicated by a solid line. The secondary molding portion 5 is molded by setting the core 4 in a molding die (hereinafter simply referred to as a mold) 6 and then injecting molten resin into a molding space 10 described later. In the following description, the vertical direction is based on the vertical direction in FIG. 3, and the horizontal direction is based on the horizontal direction in FIG.

  The core 4 has synthetic resin-made main body portions 3 dispersed in a plurality of locations, and the illustrated four bus bar circuits 2 made of metal are routed inside the main body portion 3. The core 4 includes a first member 4A extending in the horizontal direction in FIG. 1 and a second member 4B extending in the vertical direction. Both members 4A and 4B are assembled in the form shown in FIG. 1 prior to the secondary molding. It is done. The left end side of the first member 4A extends downward, and four bus bar circuits 2 shown in the figure protrude from the extended end. Further, the right end side of the first member 4A extends upward, and two bus bar circuits 2 shown in the figure protrude from the extended end. Two bus bar circuits 2 shown in the figure are routed on the second member 4B.

  The plurality of protrusions 8 are integrally provided on the outer surface of each main body 3. Of these protrusions 8, the one disposed on the upper surface of the core 4 (the surface facing the front side in FIG. 1) is the upper protrusion 8 </ b> A, and the lower surface of the core 4 (the surface facing the same side). The one arranged on the lower side is the lower projection 8B, and the one arranged on the left and right side surfaces of the core 4 (the surfaces facing the left and right sides in FIG. 1) is the side projection 8C. The protrusion 8 has a substantially conical shape, and its tip 9 (corresponding to the deformable part in the present invention) has a sharp shape, and the tips of the protrusions 8A, 8B, and 8C are respectively 9A, 9B, and 9C. To do. 3 to 5, the protrusion 8 disposed substantially at the center in the length direction of the second member 4B (protrusions denoted by reference numerals 8A, 8B, and 8C in FIGS. 1, 2, and 6). The structure will be described.

  Here, the dimensions of the core 4 will be described. As a symbol used for this dimension description, the distance between the tips 9C and 9C of the pair of side projections 8C and 8C in FIG. 1 is W2, and the tip 9A of the upper projection 8A and the tip 9B of the lower projection 8B in FIG. Let H2 be the distance between. Similarly, as shown in FIG. 3, when the mold is closed, a distance between an upper molding surface 7A described later and a lower molding surface 7C described later is H1, and a distance between both side molding surfaces 7C and 7C described later is W1. And In the primary molding, the dimensions of the core 4 are set so that H2 is larger than H1 and W2 is larger than W1. Thereby, the tip 9 of the protrusion 8 can be pressed by the molding surface 7 facing the tip 9 of the protrusion 8 when the mold 6 is closed. Further, the tip 9 of the protrusion 8 has a hardness that can be deformed (collapsed) by pressing with the molding surface 7.

  The mold 6 includes an upper mold 6A and a lower mold 6B, and the upper mold 6A includes a left mold 6AL and a right mold 6AR. FIG. 3 is a cross-sectional view showing a state in which the core 4 is set in the mold 6 and closed, and a molding surface 7 having a substantially square hole shape is formed inside the mold 6. . The molding surface 7 includes an upper molding surface 7A for molding the upper surface side of the secondary molding part 5, a lower molding surface 7B for molding the lower surface side, and a side molding surface for molding the same side surface. 7C. The upper mold 6A is provided with an upper molding surface 7A and a side molding surface 7C. The upper molding surface 7A is divided into a left mold 6AL and a right mold 6AR when the mold is opened, but the left mold 6AL side and the right mold 6AR side are flush with each other when the mold is closed. On the other hand, the lower mold 6B has a horizontal plane that is substantially parallel to the upper molding surface 7A, and the upper mold 6A is disposed on the horizontal plane. And the area | region pinched | interposed by the lower end of the both-sides molding surfaces 7C and 7C at the time of a mold closing among the horizontal surfaces is made into the lower molding surface 7B.

  The upper mold 6A is slidable along the horizontal plane of the lower mold 6B, and the left and right molds 6AL and 6AR approach each other in the horizontal direction when the mold is closed. Accordingly, the core 4 placed on the lower molding surface 7A is sandwiched from the upper and lower sides by the upper molding surface 7A and the lower molding surface 7B when the mold is closed, and is formed by the both side molding surfaces 7C and 7C. By being sandwiched from both the left and right sides, the mold 6 is held in a floating position via the protrusion 8. At this time, the tip 9 of each projection 8 is compressed and deformed by the molding surface 7 as described above so that the clearance between the tip 9 of each projection 8 and the molding surface 7 becomes zero. A molding space 10 is formed between the outer surface of the core 4 and the molding surface 7.

  FIG. 4 is a cross-sectional view showing a state in which molten resin is injected into the molding space 10 when the mold is closed. Since the tip 9 of the protrusion 8 is pressed and held by the molding surface 7, the core 4 is restricted from being displaced in the vertical and horizontal directions by molten resin injected from a gate (not shown). Further, since the tip 9 of the protrusion 8 comes into close contact with the molding surface 7 and molten resin cannot enter between the tip 9 of the projection 8 and the molding surface 7, The occurrence of thin resin burrs is restricted. FIG. 5 is a cross-sectional view of the resin molded product 1 showing a state in which the mold 6 is opened after molding. The tip 9 of the protrusion 8 is exposed on the outer surface of the secondary molded part 5.

The present embodiment has the above-described structure, and the operation thereof will be described subsequently.
First, the core 4 is placed on the lower molding surface 7B, and the mold 6 is closed. When closing the mold, the upper projection 8A is pressed against the upper molding surface 7A, the lower projection 8B is pressed against the lower molding surface 7B, and the side projection 8C is pressed against the side molding surface 7C. The tip 9 of the protrusion 8 is compressed and deformed, and the mold is closed while the clearance between the tip 9 of each protrusion 8 and the molding surface 7 is kept at zero. When the mold closing is completed, the tip 9 of each projection 8 and the molding surface 7 come into close contact with each other, and the clearance between the tip 9 of each projection 8 and the molding surface 7 is maintained at zero. Thus, a molding space 10 is formed between the outer surface of the core 4 and the molding surface 7, and the core 4 is held in a position floating in the mold 6 via the protrusion 8.

  Next, molten resin is injected into the molding space 10. At this time, since the tip 9 of each projection 8 and the molding surface 7 are in close contact with each other, the molten resin is restricted from entering between the tip 9 of each projection 8 and the molding surface 7. Further, the core 4 is in a state in which the protrusions 8 are pressed and positioned by the molding surface 7, so that displacement of the core 4 by the molten resin injected from a gate (not shown) is restricted. Thus, when the resin injection is completed, the secondary molded portion 5 is formed on the outer surface of the core 4, and the resin molded product 1 is completed when the mold is opened. At this time, the tip 9 of each protrusion 8 is exposed on the outer surface of the secondary molding part 5, and the generation of resin burrs is restricted at the tip 9 of each protrusion 8.

  As described above, according to the present embodiment, the tip 9 (deformable portion) of each protrusion 8 is deformed as the mold is closed, and the clearance between the tip 9 of each protrusion 8 and the molding surface 7 is increased. It becomes zero, and it is regulated that the molten resin enters between them and burr is generated. Moreover, since the tip 9 of each protrusion 8 has a sharp shape and is compressed and deformed, it is not necessary to provide each protrusion 8 and the deformable part separately, and the structure can be simplified.

The top view of the core in Embodiment 1 Plan view of the resin molded product Sectional drawing which shows the state before resin injection after mold closing in the AA line section of FIG. Sectional view showing the state after mold injection and before mold opening Sectional view showing the state after mold opening Side view of core in embodiment 1

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Resin molded product 3 ... Main-body part 4 ... Primary molded product (core)
5 ... Secondary molding part 6 ... Mold for molding 7 ... Molding surface 8 ... Projection (deformable part)
9 ... The tip of the protrusion

Claims (1)

A primary molded product in which a plurality of protrusions are protruded on the outer surface of the main body bus bar circuit is routed in the interior,
Secondary molded between the outer surface of the primary molded product and the molding surface of the mold held in a floating position via the protrusion in a molding die that can be opened and closed in two directions orthogonal to each other It consists of a molding part ,
The protrusions are integrally opposite to each other on two surfaces facing the pair of molding surfaces facing each other when the mold is closed in each direction among the outer surfaces of the main body of the primary molded product. The protrusion is formed, and both protrusions have a pointed tip and the tip is a deformable part .
L2 is larger than L1 when the distance between a pair of molding surfaces facing each other when each mold is closed is L1, and the total height between the tips of the corresponding pair of protrusions in the primary molded product is L2. Set,
With particular the mold is closed type, the tip of the projections each pair is compressed is the deformable portion by being pressed by both the molding surface of the mating, the between tips of the pair of projections Height There by the L1, the resin molded article, characterized in that the tip of the projecting portion on the outer surface of the secondary molded portion after secondary forming is so exposed.

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