JP5855635B2 - Manufacturing method of molded products - Google Patents

Description

The present invention is an invention related to a body portion formed in an elongated shape, producing how the polymeric material made of a molded article and a protrusion protruding from the rear surface side of the main body portion.

  In pillar garnishes mounted along the pillars of automobiles, the main body is injection-molded with a hard polymer material, and then the main body is set in an injection mold for molding a cushion portion. By injecting the cushion part (or pasting the cushion part molded with a soft polymer material to the main part with double-sided tape etc.), the cushion part is joined to the main part and the main part and the cushion part are integrated. There is something.

  Further, as described in Patent Document 1 (WO2012 / 005181), there is one in which a protruding portion is provided on the back side of the main body portion of the pillar garnish. In this Patent Document 1, an injection mold having a main body molding cavity and a protrusion molding cavity is used, and a polymer material heated and melted is injected into the main body molding cavity, so that the main body molding cavity and the protruding portion are injected. By filling the molding cavity with the polymer material, the main body portion and the protruding portion are formed, and a molded product in which the protruding portion is integrated with the main body portion is formed.

WO2012 / 005181

  However, in the technique of the above-mentioned patent document 1, when the polymer material heated and melted is injected into the main body molding cavity, and the polymer material is filled into the main body molding cavity and the protrusion molding cavity, the main body molding When the polymer material flowing in the cavity reaches the vicinity of the projection molding cavity, the flow of the polymer material is in two directions (the direction of flowing into the projection molding cavity and the direction of passing through the projection molding cavity). Therefore, the flow of the polymer material is disturbed in the vicinity of the protrusion forming cavity, and a turbulent flow of the polymer material is generated. For this reason, gloss unevenness may occur in the vicinity of the portion corresponding to the protruding portion of the surface of the body portion after molding, and the appearance may be impaired.

  Therefore, the problem to be solved by the present invention is to prevent the occurrence of uneven glossiness on the surface of the main body in a molded product having a protrusion on the back side of the main body.

In order to solve the above-mentioned problem, the invention according to claim 1 is a polymer material comprising a main body portion formed in a long shape and a protruding portion protruding from a part in the longitudinal direction on the back surface side of the main body portion. A method of manufacturing a molded product, comprising: a main body portion forming cavity for forming a main body portion; and a protruding portion forming cavity for forming a protruding portion; and in the protruding portion forming cavity. Between the closed position to enter and close the projection molding cavity and the open position to exit from the projection molding cavity and connect the projection molding cavity to the body molding cavity Using an injection mold having a movable slide mold, forming a main body molding cavity by closing the injection mold and moving the slide mold to the closed position; and a main body molding key The heated molten polymeric material is injected into the Activity, the polymeric material was the move to the open position the slide type after passing through the position of the slide to flow in the cavity for the body portion molding, continued injection of the polymeric material The molding process for forming the main body part and the projecting part by filling the main body part molding cavity and the projecting part molding cavity with a polymer material, and forming a molded product in which the projecting part is integrated with the main body part, and injection molding And taking out the molded product by opening the mold.

  In this manufacturing method, after the polymer material flows in the body molding cavity and passes through the position of the slide mold, the slide mold is moved to the open position, and the protrusion molding cavity communicates with the body molding cavity. Let it be in the state you let it. Therefore, when the polymer material flowing in the body molding cavity reaches the vicinity of the protrusion molding cavity, the flow direction of the polymer material is not divided, and the turbulent flow of the polymer material in the vicinity of the projection molding cavity Can be prevented. Thereby, it is possible to prevent the occurrence of uneven gloss in the vicinity of the portion corresponding to the protruding portion of the surface of the body portion after molding.

  In this case, as in claim 2, in the molding step, a fluid may be injected into the polymer material in the main body molding cavity to form a cavity. In this way, even in the case of a molded product having a non-uniform thickness such as a protruding portion, a fluid is injected into the polymer material in the molding process and pressure is uniformly applied from the inside of the polymer material. Thus, sink marks can be prevented from occurring in the molded product.

  Further, as in claim 3, the protruding portion is preferably formed in a columnar shape. In this way, the slide mold that enters the projection forming cavity can be made into a columnar shape (for example, a columnar shape), and the slide mold can be smoothly slid (entered / retreated).

FIG. 1 is a perspective view of a garnish body in one embodiment of the present invention. FIG. 2 is a plan view of the injection mold. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2 and shows a state where the slide mold is moved to the closed position. 4 is a cross-sectional view taken along the line AA of FIG. 2 and shows a state in which the slide mold is moving from the closed position to the open position. FIG. 5 is a cross-sectional view taken along the line AA in FIG. 2 and shows a state where the slide mold has moved to the open position. FIG. 6 is a cross-sectional view taken along the line AA in FIG. 2 and shows a state in which high pressure gas is injected. 7 is a cross-sectional view taken along line BB in FIG.

Hereinafter, an embodiment in which a mode for carrying out the present invention is applied to a pillar garnish mounted along a front pillar of a vehicle will be described.
First, a schematic configuration of the pillar garnish will be described with reference to FIG. The pillar garnish is formed by injection-molding a cushion portion (not shown) on the outer surface of a long garnish body 11 (molded product) and joining the garnish body 11 and the cushion portion together. . Alternatively, the garnish body 11 and the cushion portion may be joined and integrated by attaching the cushion portion to the outer surface of the garnish body 11 with a double-sided tape or the like.

  The garnish main body 11 is integrally provided with a main body portion 12 formed in an elongated shape and a protruding portion 13 that protrudes from a part in the longitudinal direction on the back surface side of the main body portion 12. The protrusion 13 is formed in a columnar shape, for example, when the garnish main body 11 is attached to the vehicle body, or when the cushion portion is joined to the garnish main body 11 (for example, when the garnish main body 11 is set in the injection mold of the cushion portion), etc. Used for positioning. Or you may make it form the through-hole which cuts off the protrusion part 13 from the main-body part 12, and connects with the cavity 17 in the main-body part 12. FIG.

  The garnish main body 11 (the main body portion 12 and the protruding portion 13) has a higher rigidity than the cushion portion and is formed of a hard thermoplastic polymer material. Examples of the thermoplastic polymer material for molding the garnish body 11 include acrylonitrile / butadiene / styrene resin (ABS resin), acrylonitrile / ethylene propylene / styrene resin (AES resin), rigid or semi-rigid polyvinyl chloride resin (rigid PVC). Resin), polycarbonate resin (PC resin), polypropylene resin (PP resin), polyethylene resin (PE resin), polystyrene resin (PS resin), polyamide resin (PA resin), and other thermoplastic synthetic resins are used.

  The main body 12 is integrally formed with a decorative head 14, a leg 15 that supports the decorative head 14, and a rib 16 that protrudes from one edge of the leg 15 to the back surface side. A cavity 17 (hollow part) is formed inside the part 12. A recess 18 is formed around the protrusion 13 on the back surface of the main body 12. Further, a first cushion portion (not shown) having elasticity is joined along the first edge portion 12a of the main body portion 12 (for example, the back surface of the decorative head portion 14), and the second edge portion of the main body portion 12 is joined. A second cushion portion (not shown) having elasticity is joined along 12b (for example, the side surface of the leg portion 15).

Next, the manufacturing method of the garnish main body 11 is demonstrated using FIG. 2 thru | or FIG.
As shown in FIG. 2, the injection mold 19 for injection molding the garnish main body 11 can simultaneously mold two garnish main bodies 11 (a garnish main body for the right front pillar and a garnish main body for the left front pillar). It has become.

  As shown in FIGS. 3 to 7, the injection mold 19 includes an upper mold 20 and a lower mold 21, and slide cores 22 and 23 that can move in the left-right direction with respect to the upper and lower molds 20 and 21 (see FIG. 7). ), A slide core 24 movable in the front-rear direction, a slide mold 25 movable in the vertical direction, and the like. The injection mold 19 is provided with a main body molding cavity 26 for molding the main body 12 and a projection molding cavity 27 for molding the projection 13.

  The slide mold 25 is formed in a columnar shape in accordance with the protruding portion forming cavity 27, and enters the protruding portion forming cavity 27 to close the protruding portion forming cavity 27 (see FIG. 3). And an open position (see FIG. 5) in which the protruding portion forming cavity 27 communicates with the main body forming cavity 26 by being retracted from the protruding portion forming cavity 27 so as to be slidable. Yes. The slide mold 25 is driven by an actuator (not shown) (for example, a hydraulic cylinder or an air cylinder), and can be slid and moved while the injection mold 19 is closed.

  The injection mold 19 is provided with an injection gate 28 for injecting a thermoplastic polymer material (hereinafter simply referred to as “polymer material”) P into the main body molding cavity 26, and in the vicinity of the injection gate 28, the main body molding. A gas injection part 29 for injecting a high-pressure gas (for example, nitrogen gas), which is a fluid for forming a cavity, is provided in the cavity 26 for use. Further, a discharge channel 30 is provided in a portion (the end portion opposite to the injection gate 28 in the longitudinal direction of the main body molding cavity 26) where the polymer material P injected into the main body molding cavity 26 reaches the latest. A discharge cavity 31 that communicates with the main body molding cavity 26 is provided.

The polymer material P injected from an injection nozzle (not shown) of the injection molding machine and heated and melted is runners 32 , 33 → injection gate 28 → main body forming cavity 26 and protruding portion forming cavity 27 → discharge cavity 31. It flows in the route of. Further, the high-pressure gas pumped from the high-pressure gas supply source 34 (for example, a high-pressure gas pump) is discharged from the gas injection part 29 → the body part molding cavity 26 (or the body part molding cavity 26 and the protrusion part molding cavity 27) → discharge. It flows in the path of the cavity 31 for use. Note that the position for injecting the high-pressure gas may be appropriately changed. For example, the high-pressure gas may be injected from the runner 32 or an injection nozzle (not shown).

  When manufacturing the garnish main body 11, a preparatory process is first performed. In this preparation step, as shown in FIG. 3, the injection mold 19 is closed to form the main body molding cavity 26, and the slide mold 25 is moved to the closed position so that the projection mold forming cavity 27 is moved by the slide mold 25. Is in a closed state.

  Thereafter, a molding process is performed. In this molding step, as shown in FIG. 3, the polymer material P heated and melted is injected into the main body molding cavity 26. As a result, the polymer material P flows in the main body molding cavity 26, but the slide mold 25 is moved to the closed position so as to close the protruding part molding cavity 27, so that the polymer material P slides. Even when the position of the mold 25 (the position of the protruding portion forming cavity 27) is reached, the flow of the polymer material P passes through two directions (the direction of flowing into the protruding portion forming cavity 27 and the protruding portion forming cavity 27). The polymer material P passes through the position of the slide mold 25 without being divided in the direction in which it slides. For this reason, the flow of the polymer material P is not disturbed in the vicinity of the protrusion forming cavity 27, and the occurrence of the turbulent flow of the polymer material P is prevented.

  Thereafter, as shown in FIG. 4, when a predetermined time has elapsed since the start of the injection of the polymer material P, a process of moving the slide mold 25 from the closed position to the open position is started, Move to the open position (see FIG. 5). Here, the predetermined time is set to a time required from the start of the injection of the polymer material P until the polymer material P flows in the main body molding cavity 26 and passes through the position of the slide mold 25. As a result, after the polymer material P flows through the body portion molding cavity 26 and passes through the position of the slide mold 25, the slide mold 25 is moved to the open position, and the protruding portion molding cavity 27 is formed for the body portion molding. It is in a state where it communicates with the cavity 26. In this state, the injection of the polymer material P is continued, and the polymer material P is filled in the projecting portion molding cavity 27 and the polymer material P is filled in the body portion forming cavity 26, whereby the main body portion 12 and the projecting portion are projected. The garnish main body 11 is formed by forming the portion 13 and integrating the protruding portion 13 with the main body portion 12.

  Further, in this molding process, as shown in FIGS. 5 to 7, before the polymer material P is solidified, a high-pressure gas (for example, nitrogen gas) is injected into the polymer material P in the body portion molding cavity 26. A cavity 17 is formed in the main body 12 (or the main body 12 and the protrusion 13). At this time, the cavity 17 partially swells at the entrance of the protrusion forming cavity 27. The timing of injecting the high-pressure gas may be immediately after the start of injection of the polymer material P (before the polymer material P is filled into the main body molding cavity 26), or the polymer material P is filled into the main body molding cavity 26. Later.

After performing the gas assist injection molding as described above, the polymer material P in the main body molding cavity 26 and the protrusion molding cavity 27 is cooled and solidified while maintaining the pressure of the high-pressure gas so that a cavity is formed inside. 17 molding the garnish main body 11 having a. Thereafter, the slide cores 22 and 23 shown in FIG. 7 are slid in the left-right direction and the lower mold 21 is moved downward to open the injection mold 19 and take out the garnish main body 11. Thereby, manufacture of the garnish main body 11 is completed.

  Thereafter, the garnish body 11 is set in an injection mold (not shown) for molding the cushion portion, and the cushion portion is injection-molded with a soft polymer material. Pillar garnish which united the garnish main body 11 and the cushion part by joining a cushion part to edge part 12a, 12b) is formed. At this time, the garnish body 11 can be positioned in the injection mold by using the protrusion 13 of the garnish body 11.

  Alternatively, the cushion part formed of a soft polymer material is attached to the garnish main body 11 (the edges 12a and 12b of the main body part 12) with a double-sided tape or the like, so that the garnish main body 11 and the cushion part are joined and integrated. A pillar garnish may be formed.

  In the present embodiment described above, when the garnish main body 11 is manufactured, first, the injection mold 19 is closed to form the main body molding cavity 26, and the slide mold 25 is moved to the closed position to move the slide mold 25. Thus, the protruding portion forming cavity 27 is closed. Thereafter, a polymer material heated and melted is injected into the main body molding cavity 26, and the polymer material flows in the main body molding cavity 26 to position the slide mold 25 (position of the projecting part molding cavity 27). After passing, the slide mold 25 is moved to the open position so that the protrusion forming cavity 27 is communicated with the main body forming cavity 26. In this way, when the polymer material flowing in the main body molding cavity 26 reaches the vicinity of the projection molding cavity 27, the flow of the polymer material P is not divided into two directions, and the projection molding is performed. It is possible to prevent the turbulent flow of the polymer material in the vicinity of the cavity 27 for use. Thereby, it is possible to prevent the occurrence of uneven gloss in the vicinity of the portion corresponding to the protruding portion 13 in the surface of the main body portion 12 after molding.

  Further, in this embodiment, in the molding process, the high-pressure gas is injected into the polymer material in the main body molding cavity 26 to form the cavity 17, so that the wall thickness of the protruding portion 13 is not uniform. Even if the garnish main body 11 has a portion to be made, sinking is prevented from occurring in the garnish main body 11 by injecting high pressure gas into the polymer material in the molding process and applying pressure uniformly from the inside of the polymer material. can do.

  Further, in the present embodiment, since the protruding portion 13 is formed in a columnar shape, the slide mold 25 that enters the protruding portion forming cavity 27 is formed in a columnar shape, and the slide mold 25 is smoothly slid and moved (entering / To leave).

  In the above-described embodiment, the protruding portion 13 is formed in a cylindrical shape. However, the present invention is not limited to this. For example, the protruding portion 13 is formed in a prismatic shape (for example, a rectangular column shape or a hexagonal column shape). Also good.

  Moreover, in the said Example, although it was set as the structure which provides the one protrusion part 13 in the back surface side of the garnish main body 11 (main-body part 12), it is not limited to this, A plurality is provided in the back surface side of the garnish main body 11 (main-body part 12). Alternatively, the protruding portion 13 may be provided.

  Moreover, in the said Example, although it was set as the structure which forms the cavity 17 inside the garnish main body 11, it is not limited to this, It is good also as a structure which does not form the cavity 17 inside the garnish main body 11. FIG.

  In addition, the present invention is not limited to the pillar garnish mounted along the front pillar of the automobile. For example, the pillar garnish mounted along the center pillar and the rear pillar, the body side molding mounted on the door panel, and the wheel arch. It can also be applied to wheel arch moldings (including mudguards) mounted along the belt moldings mounted along the lower edge of the side door window opening.

  DESCRIPTION OF SYMBOLS 11 ... Garnish main body (molded article), 12 ... Main body part, 13 ... Projection part, 17 ... Cavity, 19 ... Injection mold, 25 ... Slide mold, 26 ... Cavity for main body part molding, 27 ... Cavity for molding projection part

Claims (3)

A method of manufacturing a molded article made of a polymer material comprising a main body portion formed in an elongated shape and a protruding portion protruding from a part of the back surface side of the main body portion in the longitudinal direction,
A cavity for molding the main body for molding the main body and a cavity for molding the protrusion for molding the protrusion, and the cavity for molding the protrusion by entering the cavity for molding the protrusion A slide that is movable between a closed position where the projecting portion molding cavity is closed and an open position where the projecting portion molding cavity is communicated with the body portion molding cavity. Use an injection mold with a mold,
A preparation step of closing the injection mold to form the body part molding cavity and moving the slide mold to the closed position;
The molten polymer material is injected into the main body molding cavity, and after the polymer material flows through the main body molding cavity and passes through the position of the slide mold, the slide mold is moved to the open position. And continuously injecting the polymer material, filling the body material molding cavity and the protrusion molding cavity with the polymer material, thereby forming the body portion and the projecting portion to the body portion. A molding process for forming a molded product integrating the protrusions;
A method for producing a molded product, comprising: taking out the molded product by opening the injection mold.   2. The method of manufacturing a molded product according to claim 1, wherein, in the molding step, a fluid is injected into the polymer material in the body portion molding cavity to form a cavity.   The method for manufacturing a molded product according to claim 1, wherein the protruding portion is formed in a columnar shape.

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