JP2005297211A - Method for molding synthetic resin and molding apparatus used for this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for molding a synthetic resin capable of increasing a bonding force of a molded body to a substrate, and a molding apparatus used for this. <P>SOLUTION: A movable mold 4 and a mold holder 5 are retreated more than a molding position where a shape of a cavity 7 coincides with a shape of a bracket 71 and a trim board 72 is arranged so that a base body carrying device 50 closes an opening 7a of the cavity 7 by a mold moving device 30 of the molding apparatus 1. Thereafter, a molding material introducing device 10 introduces a melted molding material MZ into the cavity 7 and the mold moving device 30 forwards the movable mold 4 and the mold holder 5 to the molding position. Thereby, while the cavity 7 is shrunk, the molding material MZ is cured, and the bracket 71 is formed in the cavity 7 and is bonded to the trim board 72. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a synthetic resin molding method for joining a molded body to a substrate, and a molding apparatus used therefor.

As a conventional technique, a pair of molds are placed at predetermined positions, a cavity having the same shape as the molded body is formed therein, a base is disposed so as to close the opening of the cavity, and a synthetic resin is disposed in the cavity. There has been a method by injection molding in which a material is injected to form a molded body and bonded to a substrate (see, for example, Patent Document 1). According to this, since the molding material is injected at a high pressure so as to reach the inside of the cavity, the base closing the cavity may be joined to the base while being bent outward by the pressure of the molding material. there were. Also, when the cavity has a narrow and complicated shape, when the molding material moves through the cavity after injection and reaches the base by touching the mold, the temperature is already lowered, and the molded body is joined to the base. There was a problem that power decreased.
JP 2002-355848 A (FIG. 6)

  The present invention has been completed based on the above circumstances, and provides a synthetic resin molding method capable of increasing the bonding force between a molded body and a base, and a molding apparatus used therefor. Objective.

  As means for achieving the above-mentioned object, the invention of claim 1 is such that, when both face each other at a predetermined position, a cavity having an opening to the outside is formed between them. In addition, after the base is arranged so that the pair of molds whose size of the cavity can be changed by moving relative to each other is separated from the predetermined position and the opening of the cavity is closed. The molten molding material is introduced into the cavity and the molding dies are brought close to each other until the predetermined position is reached, whereby the molding material is cured while reducing the cavity to form the molded body. In addition, the synthetic resin molding method is characterized in that it is bonded to the substrate.

  The invention according to claim 2 is the synthetic resin molding method according to claim 1, wherein the base closes the opening of the cavity from below, and the molding material is introduced from above the cavity.

  According to a third aspect of the present invention, in the synthetic resin molding method according to the first or second aspect, the mold is relatively moved along a surface where the base closes the opening of the cavity.

  According to a fourth aspect of the present invention, a cavity having a shape of a molded body and having an opening to the outside is formed therebetween by opposing each other at a predetermined position, and the cavity is moved relative to each other. A pair of molds capable of changing the size of the mold, a mold moving device for moving the molds relative to each other, a substrate transfer device for moving the substrate so as to close the opening of the cavity, and a molding material in the cavity A molding material introducing device to be introduced, wherein the molding die moving device places the molding die in a state of being separated from each other than the predetermined position, and the substrate transporting device closes the opening of the cavity. After the movement, the molding material introducing device introduces the molten molding material into the cavity, and the molding die moving device removes the molding die from the mold. By gradually closer together until a constant position, together with the molding material while the cavity is reduced to form the shaped body and cured, and a molding apparatus characterized in that it is bonded to the substrate.

<Invention of Claim 1>
The pair of molds are placed in a state of being separated from each other at a predetermined position, and the base is disposed so as to close the opening of the cavity. By making them close to each other, the molding material is cured while shrinking the cavities to form a molded body and bonded to the base. Since the molding material is easy to spread into the cavity and the molding material can be introduced at a low pressure, the base body does not bend at the time of joining with the molded body. Further, the molding material rarely touches the wall of the cavity before reaching the substrate, and the temperature drop is suppressed, and the bonding force between the molded body and the substrate can be improved.

<Invention of Claim 2>
Since the base closes the cavity opening from below and the molding material is introduced from the top of the cavity, the molding material introduced into the cavity falls and it is easy to ride directly on the base. The bonding force between the body and the substrate can be further improved.

<Invention of Claim 3>
Since the molding die is configured to move relative to the surface closing the opening of the cavity in parallel, the molding die moves relatively along the joint portion of the molded body to the substrate. In addition, it is possible to easily perform die cutting after molding.

<Invention of Claim 4>
After the mold moving device moves the molds away from each other in a predetermined position and the substrate transport device moves the substrate so as to close the opening of the cavity, the molding material introducing device melts into the cavity. The molding material is introduced, and the mold moving device moves the molds closer to each other until it reaches a predetermined position, so that the molding material hardens while the cavity shrinks to form a molded body, and is joined to the substrate. By adopting the configuration, when the molding material is introduced, the cavity is larger than the shape of the molded body, the molding material easily spreads into the cavity, and the molding material can be introduced at a low pressure. The base body does not bend at the time of joining with the molded body. In addition, it is possible to provide a molding apparatus in which the molding material rarely touches the wall of the cavity before reaching the substrate, the temperature decrease is suppressed, and the bonding force between the molded body and the substrate can be improved.

  An embodiment of the present invention will be described with reference to FIGS. In the description, the right side in FIG. 2 is the front of the movable mold 4 and the mold holder 5. The molding apparatus 1 according to the present embodiment includes a fixed mold 3, a movable mold 4, a mold holder 5, a molding material introducing apparatus 10, a molding mold moving apparatus 30, and a substrate transport apparatus 50. The fixed die 3 is fixed by welding, press-fitting, or the like so as to hang downward in the accommodation hole 2b formed in the upper end portion 2a of the support 2. The support body 2 has an approximately inverted L shape, and a lower end portion 2c thereof is fixed to an upper portion of the substrate transport device 50, and a mold moving device 30 is attached to the side end portion 2d thereof.

  The movable die 4 is fixed to the die holder 5 with a plurality of mounting bolts 6. The movable mold 4 and the mold holder 5 have mold surfaces 4a and 5a at the front portions, respectively, which are disposed so as to face the mold surface 3a of the fixed mold 3, and between the mold surface 3a and the mold surfaces 4a and 5a. A cavity 7 is formed (see FIG. 2). The fixed mold 3, the movable mold 4 and the mold holder 5 constitute a pair of molds of the present invention. As shown in FIG. 2, the cavity 7 faces the outside in a state where a trim board 72 (corresponding to the base body of the present invention) to be described later is not disposed at the lower ends of the fixed mold 3 and the mold holder 5. Has an opening 7a. The movable mold 4 is engaged with the fixed mold 3 so as to be relatively movable in the left-right direction in FIG. 1 while its upper end is in contact with the cavity upper surface 3 b of the fixed mold 3.

  Further, the mold holder 5 fixed to the movable mold 4 is fixed to the front end portion of the slide shaft 32 constituting the molding mold moving device 30. The slide shaft 32 is connected to a moving actuator 31 (fixed to the side end 2d of the support 2) that also constitutes the mold moving device 30, and is supported via a ring-shaped guide member 33. A slide hole 2e formed at the side end 2d of the body 2 is movably inserted. The moving actuator 31 can be any of an electric motor actuator, an air cylinder, a hydraulic cylinder, an electromagnetic solenoid actuator, and the like, thereby moving the slide shaft 32 in the left-right direction. By the operation of the slide shaft 32, the movable mold 4 and the mold holder 5 move with respect to the fixed mold 3, and the size of the cavity 7 can be changed. As shown in FIG. 1, the movable mold 4 and the mold holder 5 are configured to move in parallel with the surface of the trim board 72 that closes the opening 7 a of the cavity 7.

  The mold moving device 30 is controlled by a controller (not shown). The controller moves the movable mold 4 and the mold holder 5 forward (moves to the right in FIG. 2), and moves the position shown in FIGS. It is moved to the molding position corresponding to the predetermined position of the invention and is not moved further forward. At this position, the controller detects the rotational position by, for example, a pulse encoder attached to the electric motor of the moving actuator 31 and stops the moving actuator 31 based on the detected rotational position. Alternatively, the moving actuator 31 may be stopped based on a signal generated by a limit switch (not shown) disposed between the fixed mold 3 and the mold holder 5. At the molding position, the size of the cavity 7 is minimized, and the shape thereof matches the shape of the formed bracket 71 (corresponding to the molded body of the present invention) (shown in FIG. 1).

  On the other hand, when the movable die 4 and the die holder 5 are moved backward to be in a position (initial position) farther from the fixed die 3 than the molding position described above (shown in FIG. 2), the detection is performed by the pulse encoder described above. Based on the rotation position of the electric motor of the movement actuator 31 that has been moved, the limit switch (not shown) attached to the mold holder 5 is stopped against the side end 2d of the support body 2 to stop the operation of the movement actuator 31. A stop signal is transmitted in contact with the controller, and the controller that receives the stop signal stops the operation of the moving actuator 31. As shown in FIG. 1, the cavity 7 is formed to extend in the vertical direction so as to coincide with the direction in which the molding material MZ introduced therein moves.

  The substrate transport device 50 is controlled by the controller described above, and has a box 51 to which the lower end 2c of the support 2 is fixed, and a pedestal 52 attached thereon. A transport actuator 53 similar to the movement actuator 31 is accommodated in the box body 51. An operating shaft 54 extends upward from the transport actuator 53, and a pressing portion 55 is fixed to an upper end portion thereof. Has been. A bendable cushion portion 56 formed in a flat plate shape with synthetic rubber or synthetic resin material is fixed to the upper end surface of the pressing portion 55 with an adhesive or the like.

  The pressing portion 55 is accommodated in a recess 52 a formed in the pedestal 52 at the lowest position. On the other hand, the pressing portion 55 is lifted via the operating shaft 54 by the action of the conveying actuator 53, lifts a trim board 72 (to be described later) via the cushion portion 56, and contacts the lower ends of the fixed mold 3 and the mold holder 5. Thus, the uppermost position is reached with the opening 7a closed. The transport actuator 53 detects the rotational position of an electric motor (not shown) of the transport actuator 53 at the lowermost position and the uppermost position, or stops using a limit switch or the like. It is done. Further, as will be described later, a base body guide 8 used for positioning the trim board 72 in the left-right direction is attached to the column portion 2f of the support body 2.

  The molding material introduction device 10 is controlled by a controller and is disposed above the support 2, and the lower end portion thereof is inserted into the upper end portion of the fixed mold 3. The molding material introduction device 10 includes a cylinder body 11 having an introduction cylinder 12 therein, and a pressing plunger 14 of an introduction actuator 13 is fitted in the introduction cylinder 12. The introduction actuator 13 is the same as the movement actuator 31 and, when activated, moves the pressing plunger 14 in the vertical direction. Further, at the uppermost position and the lowermost position of the pressing plunger 14, similarly to the moving actuator 31, the introducing actuator 13 is stopped using a limit switch or the like. The introduction cylinder 12 communicates with a hopper 15 that stores a molding material MZ made of a synthetic resin such as polypropylene, and can always supply the molding material MZ.

  A heating body 16 is connected to the lower end of the cylinder body 11, and a melting passage 17 is formed in the heating body 16. A plurality of electric heaters 19 are attached around the heating body 16, and the molding material MZ in the melting passage 17 is heated and melted. The lower end portion of the heating body 16 is inserted into the upper end portion of the fixed mold 3, and the molten molding material MZ can be injected into the cavity 7 from the nozzle 18 formed at the distal end portion of the melting passage 17. .

  In FIG. 7, as an example of a molded product formed by the molding apparatus 1 according to the present embodiment, a door trim 70 that is an interior product of a vehicle is shown. The door trim 70 is formed by joining the bracket 71 formed in the cavity 7 described above to the trim board 72. The trim board 72 is formed of synthetic leather, natural leather, fiber, etc. on a base material 73 formed of a synthetic resin material such as polypropylene or a material obtained by mixing polypropylene and bast plant fibers such as kenaf. In other words, the outer skin 74 is covered.

  As shown in FIG. 7, the bracket 71 joined to the trim board 72 is shaped like a half of a cylindrical body whose outer peripheral surface is inclined, and its bottom surface (surface on the trim board 72 side) 71a is flat. This is joined to the trim board 72 by welding to the surface of the base material 73. Further, a standing wall 71b is provided at the tip of the bracket 71, and a semicircular cutout 71c is formed at the center thereof. The door trim 70 is attached to the inner panel by engaging the notch 71c of the bracket 71 with a locking portion of an inner panel (not shown) of the vehicle.

  Next, a method for joining the bracket 71 using the molding apparatus 1 to the trim board 72 will be described. First, as shown in FIG. 2, the moving actuator 31 of the mold moving device 30 is actuated to move the moving mold 4 and the mold holder 5 backward (move to the left in FIG. 1) to be in the initial position. Leave it in a state. As a matter of course, at this time, the shape of the cavity 7 is much larger than the shape of the bracket 71.

  On the other hand, the trim board 72 is conveyed rightward in FIG. 2 by a conveyor (not shown), a robot, or the like until the front end of the trim board abuts against the substrate guide 8. In this state, since the trim board 72 is positioned immediately above the pressing portion 55, the pressing actuator 55 is raised by operating the transfer actuator 53 of the substrate transfer device 50, and the trim board 72 is moved to the cushion portion. 56. Thereafter, by continuing to raise the pressing portion 55, the trim board 72 comes into contact with the lower ends of the fixed mold 3 and the mold holder 5, and closes the opening 7a from below (shown in FIG. 3). At this time, the trim board 72 is pinched by the cushion portion 56 and the fixed mold 3, but the cushion portion 56 can be bent, so that the trim board 72 is not damaged.

  Next, the introduction actuator 13 of the molding material introducing device 10 is operated to lower the pressing plunger 14, and the molten molding material MZ in the melting passage 17 is pressed downward, and the nozzle 7 is used to press the cavity 7 from above. Introduce in. Since the cavity 7 is in a considerably large state when the molding material MZ is introduced, the surroundings of the molding material MZ are good, and the pressure for introducing the molding material MZ from the nozzle 18 is such that the molding material is injected in the conventional injection molding. Is set much lower than the pressure. Further, the injected molding material MZ does not touch the wall of the cavity 7 and can fall directly onto the base material 73 of the trim board 72 before the temperature decreases.

  Thereafter, before the temperature of the molten molding material MZ decreases, the moving actuator 31 is operated to move the moving mold 4 and the mold holder 5 forward (move to the right in FIG. 3), and the shape of the cavity 7 becomes It is moved to a molding position that matches the shape of the bracket 71 (shown in FIG. 4). As the movable mold 4 and the mold holder 5 move and approach the fixed mold 3, the cavity 7 is gradually reduced, and the molding material MZ in the cavity 7 is compressed. The compressed molding material MZ reaches the inside of the cavity 7, touches the wall of the molding material MZ, the temperature decreases, and the curing progresses, and the bracket 71 is molded in the cavity 7.

  Further, when the molding material MZ injected from the nozzle 18 is placed thereon, the base material 73 of the trim board 72 melts and melts with the molding material MZ, so that the bracket after the molding material MZ is cured. The bottom surface 71 a of 71 is firmly joined to the trim board 72. (See FIG. 5). When the movable mold 4 and the mold holder 5 are moved forward, the molding material MZ is compressed and the pressure rises. However, since the injection pressure in the conventional injection molding does not rise, the opening 7a of the cavity 7 is closed. The trim board 72 is not bent.

  After the elapse of time sufficient for the molding material MZ to cure, the molding die moving device 30 moves the movable die 4 and the die holder 5 backward, and a position further away from the fixed die 3 (dispensing position) than the initial position described above. To move. During the retraction of the movable mold 4 and the mold holder 5, the controller ignores the signal from the above-described pulse encoder or the limit switch attached to the mold holder 5 at the initial position and further retracts the movable mold 4 and the mold holder 5. Then, the movable die 4 and the die holder 5 are stopped at the payout position by a stop signal from a limit switch attached to another part. Thereafter, the pressing portion 55 is lowered by the substrate transport device 50, and the bracket 71 joined to the trim board 72 is taken out from the fixed mold 3 (shown in FIG. 6). Thereafter, the movable mold 4 and the mold holder 5 are moved forward again by the mold moving device 30 and moved to the initial position, and the above-described steps are repeated.

  According to this embodiment, the fixed mold 3, the movable mold 4, and the mold holder 5 are separated from each other, the trim board 72 is disposed so as to close the opening 7 a of the cavity 7, and then melted in the cavity 7. By introducing the material MZ and moving the fixed mold 3, the movable mold 4 and the mold holder 5 close to each other until they reach a predetermined position, the molding material MZ is cured while the cavity 7 is reduced to form the bracket 71. In addition, since the molding material MZ is introduced, the cavity 7 is larger than the shape of the bracket 71 when the molding material MZ is introduced, and the molding material MZ easily spreads into the cavity 7, so that the molding material MZ is reduced in pressure. Therefore, the trim board 72 is not bent and deformed when the bracket 71 is joined.

  Moreover, since the cavity 7 is large at the time of the injection, the molding material MZ easily spreads into the cavity 7 in a short time, so that a decrease in the temperature can be suppressed and the joining force between the bracket 71 and the trim board 72 can be improved. Further, when the molding material MZ is injected, since the cavity 7 is large, the injected molding material MZ directly reaches the base 73 of the trim board 72 without touching the wall of the cavity 7. The temperature drop of MZ is suppressed, and the joining property between the bracket 71 and the trim board 72 can be further improved.

  Further, since the trim board 72 closes the opening 7a of the cavity 7 from below and the molding material MZ is introduced from above the cavity 7, the temperature of the molding material MZ introduced into the cavity 7 is reduced. It becomes easy to get on the trim board 72 directly before the lowering, and the joining force between the bracket 71 and the trim board 72 can be further improved without providing an extra heating step. Furthermore, the movable mold 4 and the mold holder 5 are configured to move in parallel with the surface of the trim board 72 that closes the opening 7 a of the cavity 7, so that the movable mold 4 and the mold holder 5 are moved along the bottom surface 71 a of the bracket 71 joined to the trim board 72. The movable mold 4 and the mold holder 5 are moved, and the bottom surface 71a is not undercut, so that the mold can be easily removed after molding. Further, since the cavity 7 is formed to extend in the vertical direction so as to coincide with the direction in which the introduced molding material MZ moves in the cavity 7, the moldability of the bracket 71 can also be improved.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention. Various modifications can be made without departing from the scope of the invention.
(1) At the time of molding, the molding die on the side connected to the molding material introducing device may be moved, or both opposing molding dies may be moved.
(2) The present invention is not limited to a vehicle door trim, and can be applied to any joint product made of a synthetic resin material.
(3) The molding material is not limited to polypropylene, and any kind of synthetic resin material is applicable.

1 is an overall view of a molding apparatus according to an embodiment. FIG. 2 is an enlarged view of a main part showing a state in which the trim board is lifted by a substrate transport device in the molding apparatus shown in FIG. 1. It is a principal part enlarged view which shows the place where the molding material was inject | poured in the cavity. It is a principal part enlarged view which shows the place which advanced the movable mold | type and the mold holder 5, and reduced the cavity. It is a principal part enlarged view which shows the place which hardened the molding material in the cavity. It is a principal part enlarged view which shows the place which took out the bracket from the fixed type | mold. It is a perspective view which shows the trim board to which the bracket was joined.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Molding device 3 ... Fixed mold 4 ... Moving mold 5 ... Mold holder 7 ... Cavity 7a ... Opening 10 ... Molding material introduction apparatus 30 ... Mold moving apparatus 50 ... Base conveyance apparatus 70 ... Door trim 71 ... Bracket 72 ... Trim board MZ ... molding materials

Claims (4)

By facing each other at a predetermined position, a cavity having a molded body shape and having an opening to the outside is formed therebetween, and the size of the cavity can be changed by moving relative to each other. A pair of molds are placed in a state of being separated from the predetermined position, a base is disposed so as to close the opening of the cavity, a molten molding material is introduced into the cavity, and the mold is A synthetic resin molding method characterized in that the molding material is formed by curing the molding material while reducing the cavity while being brought close to each other until the predetermined position is reached, and is bonded to the substrate. The synthetic resin molding method according to claim 1, wherein the base closes the opening of the cavity from below, and the molding material is introduced from above the cavity. The synthetic resin molding method according to claim 1, wherein the molding die is relatively moved along a surface where the base body closes the opening of the cavity. By facing each other at a predetermined position, a cavity having a molded body shape and having an opening to the outside is formed therebetween, and the size of the cavity can be changed by moving relative to each other. A pair of molds,
A mold moving device for moving the molds relative to each other;
A substrate transport device that moves the substrate so as to close the opening of the cavity, and a molding material introduction device that introduces a molding material into the cavity,
After the mold moving device moves the molds away from the predetermined position, the substrate transport device moves the substrate so as to close the opening of the cavity, and then introduces the molding material. The apparatus introduces the molten molding material into the cavity, and the mold moving device brings the molding mold closer to each other until the predetermined position is reached, so that the molding material is reduced while the cavity is reduced. A molding apparatus characterized by being cured to form the molded body and being bonded to the substrate.

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