JP2012236373A - Molding die device of resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding die device of the resin molding that can make the other punching block a moving structure without using a hydraulic cylinder.SOLUTION: A punching block 3 of the movable side arranged protruding from the mold surface 1A of a core mold 1 by gas spring 6 is pressed by the punching block 4 of the fixed side provided on a mold surface 2A of a cavity mold 2 in a mold clamping and injection process and moves back. As a result, a pressure welding state of the punching blocks 3 and 4 is maintained by a big spring force of the gas spring 6, and a porous part G that has a lot of perforations in resin molding D-T can be molded.

Description

  The present invention relates to a molding apparatus for a resin molding, and more particularly to a molding apparatus suitable for molding a resin molding in which a porous portion having a large number of perforations such as a speaker grille is integrally provided.

  In Patent Document 1, as a molding apparatus for a vehicle door trim integrally provided with a speaker grill, a punching block for molding the speaker grill is arranged oppositely on each mold surface of a pair of molds. A technique is disclosed in which one punching block is a movable structure that can be brought into contact with and separated from the other punching block.

JP 2001-260184 A

  In the disclosed technique of Patent Document 1, a hydraulic cylinder is disposed inside one mold, and the one punching block described above is moved forward and backward by this hydraulic cylinder.

  As described above, when the punching block is advanced / retreated by the hydraulic cylinder, if the size of the punching block is large, it is necessary to enlarge the hydraulic cylinder in order to increase the operating force.

  For this reason, the area occupied by the hydraulic cylinder in the mold becomes large, and the layout of the ejector pins attached to the punching block and the guide pins and guide bushes constituting the moving guide means of the punching block becomes difficult.

  In addition, when a vehicle door trim integrally provided with a speaker grill using this mold apparatus is injection-foam molded by a core back molding method in which a general part excluding the speaker grill is foam-molded, mold clamping, and It is necessary to control the operation of the hydraulic cylinder of the punching block in synchronization with the core back, and it cannot be denied that the control circuit configuration becomes complicated.

  Accordingly, the present invention provides a molding apparatus for a resin molded body in which one punching block can have a movable structure without using a hydraulic cylinder and can adopt a core back molding method.

The molding apparatus for a resin molded body of the present invention has a punching block for forming a porous portion of a resin molded body facing each mold surface of a pair of molds clamped and opened by a mold opening / closing means. The one punching block has a movable structure that can be brought into contact with and separated from the other punching block, and the movable punching block is disposed in one mold. It is arranged so as to protrude from the mold surface of the one mold by a spring and can be moved back into the one mold by being pressed against the other punching block in the mold clamping / injection process. Is the main feature.

  According to the present invention, the movable punching block that protrudes from the mold surface of one mold by the gas spring is pressed and moved backward by the other fixed punching block in the mold clamping / injection process. Thereby, the pressure contact state of both punching blocks is maintained by the large spring force (reaction force) of the gas spring, and a porous portion having a large number of perforations in the portions corresponding to these punching blocks can be formed.

  Since the gas spring is small enough to obtain a large spring force, the occupied area in the mold can be minimized. Accordingly, it is possible to increase the degree of freedom of the layout of the attached portions such as the ejector pins of the movable punching block.

  Moreover, since the pressure contact state of both punching blocks can be maintained by the spring force of the gas spring, it is possible to adopt a core back molding method in which a foaming space is formed by the core back and the filled resin material is foam molded.

Cross-sectional explanatory drawing which shows one Embodiment of the shaping die apparatus of this invention in order of a process in (A)-(D). The schematic external appearance perspective view which shows the punching block of a movable side.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  1 includes a pair of molds, for example, a core mold 1 and a cavity mold 2 that are clamped and opened by a general-purpose mold opening / closing means.

  A punching block for forming a porous portion G in a resin molded body DT such as a speaker grill portion of a vehicle door trim, for example, at required portions of the mold surfaces 1A and 2A of the core mold 1 and the cavity mold 2 3 and 4 are arranged facing each other.

  The punching block 4 is fixed to the cavity mold 2, while the punching block 3 is movably disposed on the core mold 1 so as to be in contact with and away from the punching block 4.

  The punching blocks 3 and 4 are formed with a large number of protrusions 3a and 4a facing each other on their mold surfaces, and the perforations in the above-described porous portion G are formed by abutting the pair of facing protrusions 3a and 4a.

  The punching block 3 is slidably accommodated in the recess 5A provided in the core mold 1. A plurality of gas springs 6 are embedded in the bottom of the recess 5A. The end of the operating rod 6a of the gas spring 6 is connected to or abutted against the bottom surface of the punching block 3, and the punching block 3 is urged in the protruding direction by the spring force of the gas spring 6.

  Thus, in a normal state, the punching block 3 is disposed so as to protrude from the mold surface 1A of the core mold 1 and is pressed against the punching block 4 on the fixed side of the cavity mold 2 in the mold clamping / injection process. The punching block 3 is moved back into the core mold 1 against the spring force of the gas spring 6.

  Further, the punching block 3 has an advancing position where the protrusion is restricted by the locking of the stopper means 7A and 7B provided on the opening peripheral edge of the recess 5A and the outer peripheral surface of the punching block 3, and the recess 5A when the mold is clamped. The range of movement is restricted to a retreat position that is attached to the bottom surface of the head.

  The advancing / retreating operation of the punching block 3 includes a plurality of guide pins 8 planted on the bottom surface of the punching block 3 and a guide bush 10 fitted and fixed to an opening of a pin receiving hole 9 provided on the bottom surface of the recess 5A. And sliding guide.

  On the bottom surface side of the core mold 1, a recess 5 </ b> B is formed corresponding to the recess 5 </ b> A, and an ejector plate 12 in which a plurality of ejector pins 11 are implanted is accommodated.

  The ejector pins 11 are inserted and arranged in pin receiving holes 13 penetrating the core mold 1 and the punching block 3 respectively.

  The ejector plate 12 is advanced / retracted by a hydraulic cylinder 14 provided on a mold platen (not shown). The ejector plate 12 is advanced / retracted by a plurality of guide pins 15 implanted on the bottom surface of the recess 5B and the ejector. The guide bush 16 is fixed to the plate 12 so as to pass therethrough.

  A related configuration of the punching block 3, the ejector pin 11, the ejector plate 12, and the like is schematically shown as a perspective view in FIG.

  A case where the resin molding DT is injection-foamed by the core back molding method using the molding die apparatus having the above configuration will be described in detail with reference to FIG.

  FIG. 1A shows a state where the core mold 1 and the cavity mold 2 are opened. In this state, the punching block 3 is in the advanced position protruding from the mold surface 1 </ b> A of the core mold 1 by the spring force of the gas spring 6.

  FIG. 1B shows a mold clamping / injection process. In this process, the punching block 4 of the cavity mold 2 abuts on and presses the punching block 3 at the above-mentioned advanced position. At the mold clamping position, the punching block 3 is pressed and moved to the retracted position where the bottom of the concave portion 5 bottoms against the spring force of the gas spring 6.

  For example, the foamable molten resin material M is injected and filled into the cavity immediately before the punching blocks 3 and 4 come into contact with each other, and the punching block 3 is bottomed by the recess 5 between the punching blocks 3 and 4. Done.

  FIG. 1C shows a core back process, in which the core mold 1 is moved backward in the direction of expanding the cavity volume by a predetermined amount from the mold clamping state of FIG. As a result, a necessary foaming space S is formed between the core mold 1 and the cavity mold 2 while maintaining the state where the punching blocks 3 and 4 are in pressure contact with each other by the spring force of the gas spring 6. In the foaming space S, the above-described injection-filled foamable molten resin material M is foam-molded. In the portion where the punching blocks 3 and 4 are in pressure contact with each other, foaming of the foamable molten resin material M is suppressed, and a porous portion G in which perforations are formed is formed by butting the protrusions 3a and 4a.

  FIG. 1 (D) shows a die-cutting process of the resin molded body D / T. The core mold 1 and the cavity mold 2 are opened, and the ejector pin 11 is advanced to move the resin molded body D / T. Die-cut.

  As described above, according to the molding die apparatus of the present embodiment, the movable punching block 3 that is arranged to protrude from the mold surface 1A of the core mold 1 by the gas spring 6 is the cavity mold 2 in the mold clamping / injection process. It moves backward by being pressed by the punching block 4 on the fixed side provided on the mold surface 2A.

  Thereby, the press-contact state of both punching blocks 3 and 4 is maintained by the big spring force (reaction force) of the gas spring 6.

  As a result, the resin molded body DT can be molded into a porous portion G having a large number of perforations in portions corresponding to the punching blocks 3 and 4 that are in pressure contact with each other.

  Here, since the gas spring 6 is small enough to obtain a large spring force, the occupied area in the core mold 1 can be made as small as possible. Accordingly, it is possible to increase the degree of freedom of the layout of the attached components such as the guide pins 8 and the ejector pins 11 of the movable punching block 3.

  Further, since the punching block 3 restricts the advance position by the spring force of the gas spring 6 by the stopper means 7A, 7B, it is possible to avoid the loose movement when the mold is opened. On the other hand, since the retreat position is regulated by being attached to the bottom surface of the recess 5 of the core mold 1, it is possible to obtain the burr cutting accuracy between the punching blocks 3 and 4 at the time of mold clamping.

  Since the pressure contact state of the punching blocks 3 and 4 can be maintained by the spring force of the gas spring 6 as described above, the core back molding method is employed in which the foaming space S is formed by the core back and the filled resin material is foam molded. It is possible to obtain a resin molded body DT corresponding to a request in which a general portion other than the porous portion G is foamed.

1 ... Core mold (one mold)
2 ... Cavity mold (the other mold)
DESCRIPTION OF SYMBOLS 1A, 2A ... Mold surface 3 ... Punching block 4 of movable side (one side) ... Punching block 5A of fixed side (other side) ... Recess 6 ... Gas spring 7A, 7B ... Stopper means DT ... Resin molding G ... Porous part S: Foaming space M: Expandable molten resin

Claims (3)

A punching block for forming a porous portion of the resin molded body is opposed to each mold surface of the pair of molds clamped and opened by the mold opening / closing means, and one punching block is connected to the other punching block. It has a movable structure that can contact and leave the punching block,
The movable punching block is disposed so as to protrude from the mold surface of one mold by a gas spring disposed in one mold, and pressed against the other punching block in the mold clamping / injection process. Thus, a molding die apparatus for a resin molding, which can be moved backward in the one die.   The movable punching block has a movement range restricted to an advance position where the protrusion is restricted by the stopper means and a retreat position where the bottom of the concave portion of the one mold containing the movable punching block is bottomed. The molding die apparatus for a resin molded body according to claim 1, wherein 3. The resin molded body according to claim 1, wherein the one mold moves in a direction of expanding the cavity volume after filling with the foamable molten resin to form a foaming space. 4. Molding mold equipment.

Images