JP5464702B2 - Method for producing soft resin molded product - Google Patents

Description

  The present invention relates to a method for producing a soft resin molded article.

  Vehicle interior parts such as instrument panels and door panels are installed in the passenger compartment of the vehicle. For example, an instrument panel having a three-layer structure having a foam layer between a skin material and a core material is known, and by using the three-layer structure, texture and touch are improved.

  There are various methods for forming the skin material for forming the skin material. For example, a paint film is sprayed on the inner surfaces of a pair of molds to form a coating film, and after the molds are clamped, There is known a reaction injection molding method for injecting a resin material and molding a soft resin molded product integrated with a coating film in a mold.

  The demolding operation of taking out the skin, which is the soft resin molded product, from the mold is performed by an ejector device embedded in the mold. Specifically, a soft resin molded product is extruded by extruding an ejector pin from the molding surface of the molding die using a cylinder arranged inside the molding die, and the molding surface of the molding die and the soft resin molded product are extruded. A gap is provided between them, gas is fed into this gap, and the soft resin molded product is peeled off from the mold and taken out. However, since resin materials used for reaction injection molding generally have high adhesiveness and fluidity that is liquid and close to water, if an ejector pin is set in the mold, the liquid resin injected into the mold Before the resin hardens, the liquid resin moves around the gap between the ejector pin and the molding die, or from the gap into the sliding part of the ejector pin, and the liquid resin reacts and solidifies in the fine gap and the sliding part becomes immobile. Therefore, a seal mechanism such as packing or O-ring is provided between the ejector pin and the mold (see Patent Document 1).

JP 2009-202440 A

  In Patent Document 1, a seal mechanism such as a packing and an O-ring is provided between the ejector pin and the mold. However, when the seal mechanism deteriorates, the liquid resin enters the sliding portion from the deteriorated portion and slides. There is a possibility that the moving part will not move.

  The present invention was made in view of such technical problems of the prior art, and is a soft resin molding that can easily take out a soft resin molded product from a mold without using a movable mechanism such as an ejector pin. It aims at providing the manufacturing method of goods.

  In order to achieve the above object, in the present invention, in a method for producing a soft resin molded product by injecting a molding material into a molding space formed by a pair of molding dies, a step of clamping the pair of molding dies. And a step of injecting a molding material into a molding space formed by the pair of molding dies, and forming a demolding auxiliary portion that protrudes to the side that does not contact one molding die when the mold is opened at least at the outer peripheral edge of the molded product And opening the pair of molding dies, and applying an external force inwardly from the outer peripheral direction to the demolding assisting portion of the soft resin molding that remains in one of the molds, the soft resin molding A part of the peripheral edge of the soft resin molded product is peeled off from the mold surface, and the mold surface side of the peeled soft resin molded product is pressed to demold the soft resin molded product.

  According to the present invention, a soft resin molded product can be easily taken out from a mold without using a movable mechanism such as an ejector pin.

It is a back surface side perspective view of the soft resin molded product which concerns on this invention. It is sectional drawing which simplifies and shows the shaping | molding apparatus of a soft resin molded product. It is a flowchart which shows the process of the shaping | molding method of a soft resin molded product. It is sectional drawing for demonstrating the cross-sectional enlarged view of the outer periphery formation part of the shaping | molding die of the shaping | molding apparatus of FIG. 2, and the demolding process of a soft resin molded product. It is sectional drawing of the soft resin molded product along the AA line of FIG. It is sectional drawing of the soft resin molded product along the BB line of FIG. It is the modification of embodiment, and is sectional drawing for demonstrating the cross-sectional enlarged view of the outer periphery formation part of a shaping | molding die, and the demolding process of a soft resin molded product. It is a modification of embodiment, and is a cross-sectional enlarged view of the outer periphery formation part of a shaping | molding die.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(Instrument panel configuration)
A resin instrument panel is provided at the front of the interior of a vehicle such as an automobile. The instrument panel has a three-layer structure including a foam layer between the skin material and the core material. By adopting a three-layer structure, a high quality feeling can be obtained by the soft touch of the skin material and the elasticity of the foam layer. The skin material is a resin molded product formed of a soft resin, and the core material is formed of a hard resin. The foam layer is made of a urethane material or the like.

  This three-layered instrument panel is a soft resin molded product that has been pre-formed on a foaming mold, with a skin material and core material set, and a liquid foaming agent injected between the skin material and the core material. It is manufactured by foaming to make a foamed layer.

(Soft resin molded product)
FIG. 1 shows a back side perspective view of a soft resin molded product 100 that becomes the above-described skin material. The soft resin molded product 100 is molded using a mold coating technique and a reaction injection molding technique. For example, paint is applied to the inner surface of a mold to form a coating film (mold coating), and two or more reactive liquids (polyol, isocyanate, etc.) that are reactive after mold clamping are measured, mixed, and molded. It is formed by a reaction injection molding method in which a soft resin molded article 100 is manufactured by being fed into a mold and reacted.

  Further, the soft resin molded product 100 is formed by integrally forming a product part 110 that finally becomes a product and a product exterior 120 that is the outside of the product part 110. The product exterior 120 is formed by an outer peripheral edge 121 extending from the product part 110 to the outer peripheral side. On the side of the product portion 110 that becomes the product surface, a texture such as a skin pattern formed with fine irregularities is formed. In addition, the molded soft resin molded product 100 is set in the foamed mold together with the core material and foam-molded to form an instrument panel having a three-layer structure. A plurality of positioning projections 122 serving as positioning portions for setting are formed so as to project toward the product surface side.

(Overall configuration of molding equipment)
FIG. 2 shows a molding apparatus 200 for molding a soft resin molded product 100 by a reaction injection molding method. The molding apparatus 200 includes a pair of molding dies 230 including a cavity mold 210 serving as a lower mold and a core mold 220 serving as an upper mold, and an injection unit 250 for injecting (injecting) a resin material into the mold. And a control unit 240 that controls each operation of the injection unit 250 and the pair of molds 230 and the like.

  The core mold 220 is provided so as to be movable toward and away from the cavity mold 210. The mold 230 is clamped by moving the core mold 220 closer to the cavity mold 210. The mold 230 is opened by moving the core mold 220 away from the cavity mold 210. The mold clamping and mold opening operations of the mold 230 are performed by a control signal S1 transmitted from the control unit 240. The details of the injection means 250 for injecting (injecting) the resin material into the mold will be described later.

(Cavity mold)
The cavity mold 210 forms a first molding surface 211 having a partially uneven shape in accordance with the outer shape on the surface side of the soft resin molded product 100, and the soft resin of the first molding surface 211. A textured shape such as a leather pattern formed by fine irregularities is transferred and formed on a corresponding portion to be the product portion 110 of the molded product 100. Further, the outer peripheral edge of the first molding surface 211 is formed in the same plane as the mold matching surface 212 of the cavity mold 210 and the core mold 220, and a plurality of the positioning protrusions 122 are formed on the outer peripheral edge. A recess for forming a positioning protrusion is formed (not shown).

(Core type)
On the other hand, the second molding surface 221 of the core mold 220 is partially formed with an irregular portion having a shape that substantially matches the irregular portion provided on the first molding surface 211 (fine irregularities of the fine wrinkles). Except).
Further, the vicinity of the outer peripheral edge forming the outer peripheral edge 121 of the soft resin molded product 100 of the second molding surface 221 is formed in an outer shape that is parallel to the mold matching surface 212 of the cavity mold 210 and the core mold 220. In addition, a rectangular shape for forming a demolding assisting portion 123 (see FIG. 1) as an assisting means at the time of demolding the soft resin molded product 100 from the cavity mold 210 on the outer peripheral edge of the second molding surface 221. A plurality of demolding assisting portion forming recesses 222 are formed along the outer peripheral edge. The mold release assisting portion forming recess 222 is formed in a rectangular recess extending along the direction of the outer peripheral edge.

  Further, the mold release auxiliary portion forming recess 222 is formed in the vicinity of the positioning projection forming recess for forming the positioning projection 122 formed in the cavity mold 210.

  In addition, a cavity 235 (molding space) that matches the outer shape of the soft resin molded product 100 is formed between the first molding surface 211 and the second molding surface 221 by clamping the mold. When the resin material is injected into the cavity 235, the air remaining in the cavity 235 and the gas generated from the resin material gradually gather with the spread of the injected resin material in the cavity 235, and finally the resin material Although gathered in the final flow part, the demolding auxiliary part forming concave part 222a is also provided at a position corresponding to the final flow part, and the demolding auxiliary part forming concave part 222a is also used as an air reservoir. Note that the removal assisting portion forming recess 222a at a position corresponding to the final flow portion is formed deeper than the other release assisting portion forming recesses 222a. Further, the position of the final flow part is obtained in advance by flow analysis or the like, or a mold removal assisting part forming concave part 222 formed at a position farthest from the injection means 250 for injecting the resin material into the mold. May be formed deeper than the other recesses 222 for forming the mold release assisting portion.

(Resin injection)
The injection means 250 for injecting resin into the cavity 235 shown in FIG. 2 includes a resin material supply unit 252 for supplying a resin material stored in a chamber (not shown), and a resin material injection head for injecting the resin material into the cavity 235. 251 and a resin material while causing a polyol component and an isocyanate component, which are liquid resin raw materials having fluidity and adhesiveness, to collide at high pressure from a resin material supply unit 252 in accordance with a control signal S2 transmitted from the control unit 240 It is injected into the cavity 235 through the injection head 251 and the gate 231 provided between the cavity mold 210 and the core mold 220.

(Molding method)
Next, a method for molding the soft resin molded product 100 will be described. FIG. 3 is a flowchart showing the steps of the molding method of the soft resin molded product 100. The molding method of the soft resin molded product 100 will be described with reference to the flowchart.

  First, a step of applying a release agent is performed (S11). The mold release agent is applied in order to make it easy to take out a soft resin molded product from the mold 230, and the cavity mold 210 and the core mold 220 are opened, and the first molding surface 211 and the second molding are performed. A release agent is applied to the surface 221 using a release agent spray gun (not shown).

  Subsequently, a step of arranging a masking jig is performed (S12). The masking is for preventing the coating material from being applied to the mating surface 212 of the cavity mold 210 or an unintended range when the coating material is applied in the next process. And restrict the range where the paint is applied (not shown).

  Next, a step of applying a paint to the first molding surface 211 of the cavity mold 210 is performed (S13). The coating is applied to form a coating film to form the design appearance of the soft resin molded product 100, and the coating film is formed on the entire first molding surface 211 using a coating film spray gun. Apply paint as shown (not shown).

  Next, a step of removing the masking jig is performed (S14). The masking jig arranged on the mating surface 212 of the cavity mold 210 is removed (not shown).

  Next, a step of clamping is performed (S15). After the step of applying the paint, the core mold 220 is moved closer to the cavity mold 210 and the mold 230 is clamped. A cavity 235 having a shape matching the outer shape of the soft resin molded product 100 is formed between the first molding surface 211 of the cavity mold 210 and the second molding surface 221 of the core mold 220 (FIG. 2). reference).

  Next, a step of injecting a resin material is performed (S16). The injection means 250 injects into the cavity 235 through a gate provided between the cavity mold 210 and the core mold 220 while colliding a polyol component and an isocyanate component, which are liquid resin raw materials having both fluidity and adhesiveness, at high pressure. .

  Next, a mold opening step is performed (S17). In a state where the resin material injected into the cavity 235 is cured and the coating film and the resin material are integrally molded, the core mold 220 is moved away from the cavity mold 210 to open the molding mold 230. In the present embodiment, a textured shape such as a skin pattern formed by fine irregularities is transferred and formed on the first molding surface 211 of the cavity mold 210, and the soft resin molded product 100 is transferred from the first molding surface 211. In addition to being difficult to peel off, the outer shape of the soft resin molded product 100 is an undercut shape with respect to the cavity mold 210, so that the soft resin molded product 100 remains on the cavity mold 210 side. .

  4 shows an enlarged cross-sectional view of the outer peripheral edge forming portion of the mold 230 and a demolding process of the soft resin molded product 100. FIG. 4A shows the mold 23 being clamped and the resin material being FIG. 4B shows the injected state, and the resin injected from the state of FIG. 4A is cured, the core mold 220 is moved away from the cavity mold 210, and the mold 230 is opened to open the cavity mold. The state where the soft resin molded product 100 remains on the 210 side is shown.

Next, a step of removing the soft resin molded product and removing it from the mold is performed (S18).
As shown in FIG. 4, at the outer peripheral edge of the soft resin molded product 100, the demolding assisting portion 123 is formed in the core mold 220 so that the demolding assisting portion 123 is directed toward the core mold releasing direction. Protrusions are formed. Note that the side on which the demolding assisting portion 123 is formed is the back side of the soft resin molded product 100. Further, the mold release assisting portion 123 is thicker than the general thickness of the soft resin molded product 100 and has a draft angle, and is formed of prismatic ribs extending along the outer peripheral edge 121 of the soft resin molded product 100. Yes.

  In order to remove the soft resin molded product 100 from the state in which the soft resin molded product 100 remains on the cavity mold 210 side, as shown in FIG. By applying an external force F in the horizontal direction toward the center or inward of the resin molded product 100, the vertical wall surface on the product part side of the demolding assisting portion 123 and the general plate thickness portion 125 in the demolding assisting portion 123 The product-side base 124 serving as an intersection is a starting point of deformation, and the outer peripheral edge 121 outside the mold release assisting part 123 rises and the outer peripheral edge of the soft resin molded product 100 and the first molding surface 211 on the cavity mold 210 side. Since a space 261 is formed between them, a fingertip 260, a jig, or the like is inserted into the space 261, and the mold surface side (first molding surface 211 side) of the soft resin molded product 100 is pressed to obtain the first molding surface. 211 to soft tree By gradually peeling the molded product and sufficiently expanding the space 261, the edge of the soft resin molded product 100 is gripped and the soft resin molded product 100 is peeled off from the first molding surface 211. The mold is released, and a soft resin molded product is taken out from the cavity mold 210.

  For the undercut portion, the soft resin molded product 100 is taken out by elastically deforming the soft resin molded product 100. In addition, when taking out the soft resin molded product, the soft resin molded product is taken out with both hands holding the edge of the soft resin molded product 100 so that the soft resin molded product does not break.

  Note that the outer peripheral edge portion outside the demolding assisting portion 123 easily rises when a horizontal external force F is applied to the demolding assisting portion 123 from the outside to the inside, because the soft resin molded product 100 is a soft resin. It is because it is formed by.

  The shape of the demolding assisting portion 123 will be described in more detail with reference to FIGS. FIG. 5 shows a cross-sectional view of the soft resin molded product 100 along the line AA in FIG. 1, and FIG. 6 shows a cross-sectional view of the soft resin molded product along the line BB in FIG. ing. The height (H), width (L), thickness (D), and mold release gradient of the demolding assisting portion 123 can be arbitrarily set, but the center or inside of the soft resin molded product from the product outer peripheral direction by the human fingertip 260. Since the external force F is applied in the horizontal direction toward the direction, it is sufficient that the fingertip 260 is at least large enough to be caught. In this embodiment, the height (H) is 4 mm, the width (L) is 12 mm, the thickness (D) is 7 mm, and the draft is about 1.5 °. If the height (H) is low, the fingertip 260 is not caught, and the applied external force F is not sufficiently transmitted to the protrusion shape, and the force escapes. On the other hand, if the thickness (D) is small, the demolding assisting portion 123 itself is deformed, and a sufficient deformation starting point for demolding is not created, and smooth demolding cannot be performed. Further, even when the width (L) is narrow, the fingertip 260 is not caught and the applied external force F is not sufficiently transmitted to the protrusion shape, and the force escapes.

  As described above, according to this embodiment, in the method of manufacturing the soft resin molded product 100 by injecting the molding material into the molding space 235 formed by the pair of molding dies 230, The step of clamping and the molding material is injected into the molding space 235 formed by the pair of molding dies 230, and at least the outer peripheral edge 121 of the molded product does not contact one of the molding dies (cavity mold 210) when the mold is opened. A step of forming a mold release assisting portion 123 projecting to the side, and the pair of molds 230 are opened, and the mold release assist of the soft resin molded product 100 left in one mold (cavity mold 210). A part of the periphery of the soft resin molded product 100 is peeled off from the mold surface by applying an external force F to the portion 123 from the outer peripheral direction to the inside, and the peeled soft resin molded product 10 is peeled off. A step of pressing the mold surface side of the soft resin molded product 100 to remove the soft resin molded product 100, so that the soft resin molded product can be easily produced without using a movable mechanism such as an ejector pin. The resin molded product can be taken out from the mold 230.

  In addition, when the positioning protrusion 122 serving as a positioning portion is formed on the outer peripheral edge 121 of the soft resin molded product 100 when the foam molding die is set (when the instrument panel having a three-layer structure is manufactured), the cavity The mold 210 will be formed with a positioning projection forming recess. However, the positioning projection forming recess has a small concave shape, so that the application of the release agent is deteriorated and the concave shape itself. Although the releasability is further deteriorated due to the anchor effect, the demolding assisting portion 123 is formed on the side of the core mold 220 corresponding to the vicinity of the positioning projection forming recess so that the demolding assisting portion 123 has a circumferential direction. When an external force is applied from the inside to the inside, the peripheral edge of the soft resin molded product 100 is peeled off from the mold surface, and the positioning projection forming recess is pulled together, so that air enters the positioning projection forming recess. Easier to enter, -Decided releasability of projection forming recess (peeling) can be improved.

  It should be noted that the position where the demolding assisting portion 123 is provided is in the vicinity of the positioning projection forming recess. When an external force is applied to the demolding assisting portion 123 from the circumferential direction to the inside, the positioning projection forming recess is also located together. In other words, the fingertip 260 and a jig are inserted into the space 261 formed by the soft resin molded product 100 rising, and the mold surface side of the soft resin molded product 100 (the first side) This refers to the range in which the positioning projection forming recess is easily pulled in the initial stage of pressing the molding surface side).

  A plurality of the demolding assisting portions are formed by a demolding assisting portion forming recess 222 formed in the other mold (core mold 220) of the molding die, and at least one demolding assisting portion forming recess (cavity 235) is formed. Demolding assisting portion forming recess 222 at a position corresponding to the final flow portion of the resin material injected into the mold, or demolding assist formed at a position farthest from the injection means 250 for injecting the resin material into the mold The part forming recess 222) is formed deeper than other mold release assisting part forming recesses and has a function as an air reservoir, so that there is no nest in the soft resin molded product 100 or insufficient filling. A good soft resin molded article 100 can be formed.

(Modification)
FIG. 7 is a modified example of the above-described embodiment, and shows an enlarged cross-sectional view of the outer peripheral edge forming portion of the molding die 230 and a demolding process of the soft resin molded product 100. Portions common to the members shown in FIGS. 1 to 6 are denoted by the same reference numerals, and description thereof is partially omitted.

  This modification is the same as the above embodiment from the step (S11) of applying a release agent to the mold 230 to the step of opening the mold 230 (S17), and the soft resin molded product 100 is demolded. However, only the step (S18) is different, and only that step will be described.

  In order to remove the soft resin molded product 100 from the state where the soft resin molded product 100 remains on the cavity mold 210 side, as shown in FIG. By applying an external force F in the horizontal direction from the direction toward the center or inward of the soft resin molded product 100, the vertical wall surface and the general plate thickness portion on the product part side of the mold release auxiliary part 123 in the mold release auxiliary part 123 The outer peripheral edge 121 outside the mold release assisting part 123 rises with the product-side base 124 that is an intersection with the outer edge 125 as a starting point of deformation, and the outer peripheral edge 121 of the soft resin molded product 100 and the first on the cavity mold 210 side. Since the space 261 is formed between the molding surface 211 and the other hand, the air gun 262 is held with the other hand, and the air gun 262 is moved so as to gradually expand the space 261 in the horizontal direction toward the space 261. While feeding the compressed air, it is peeled from the state mold surface side of the resin molded article 100 of the soft (first molding surface 211 side) by pressing the resin molded product 100 of the soft first shaping surface 211 are in close contact. The soft resin molded product 100 can be released from the cavity mold 210 by advancing this operation from the outer periphery of the cavity mold 210 toward the center. When the soft resin molded product 100 is finally released from the cavity mold 210, the cavity mold 210 prevents the soft resin molded product from being folded while the edges of the soft resin molded product 100 are held with both hands. Take out from.

  In the above modification, a person operates the air gun 262 to supply compressed air to the space 262 in the space 261 between the outer peripheral edge 121 of the soft resin molded product 100 and the first molding surface 211 on the cavity mold 210 side. However, as shown in FIG. 8, an air discharge port 263 directed toward the space 261 may be provided at the periphery of the cavity mold 210, and compressed air may be blown out from the air discharge port 263 in conjunction with the demolding operation. The air supply circuit for supplying air to the air discharge port 263 supplies a pressure adjusting valve 265 for adjusting the pressure of compressed air supplied from a compressor (not shown) and supplies the compressed air whose pressure has been adjusted to the air discharge port 263. It comprises an electromagnetic valve 264 for controlling and a control device 266 for controlling the electromagnetic valve.

  As described above, according to this modification, compressed air is fed into the space 261 between the outer peripheral edge of the soft resin molded product 100 and the first molding surface 211 on the cavity mold 210 side, and the soft resin molded product is thus obtained. Since the mold surface side (first molding surface 211 side) is pressed and the soft resin molded product 100 is peeled from the first molding surface 211 in close contact with each other, it can be efficiently peeled off and the soft resin This has the effect that the molded product is not easily broken.

  Further, when the soft molded resin product is peeled off from the first molding surface 211 in close contact, or finally when the soft resin molded product 100 is released from the cavity mold 210, the soft resin molded product with both hands is used. An opening such as a ventilator that is punched out in the final product within the product portion 110 of the soft resin molded product 100 in order to make it difficult for the soft resin molded product to be broken when gripping 100 and removing from the cavity mold 210. Support the mold release or removal by sucking and supporting the corresponding part with a jig etc. using a suction pad, or assisting the mold release or removal by inserting the demolding auxiliary part 123 with the jig It is effective.

  In addition to the polyurethane resin, the molding material used in the present invention is capable of molding a soft resin molded product such as a two-component thermosetting resin such as a polyamide resin, an epoxy resin, or a polyester resin. I just need it.

  Moreover, in the said embodiment, although demonstrated by reaction injection molding, it is not limited to this, This invention is applicable if it is injection molding which can shape | mold a soft resin molded product.

100 ·································································· 121
220... Core type (the other type)
222 ··· Demolding auxiliary portion forming recess 230 ··· Mold 235 · · · Cavity (molding space)

Claims (3)

In a method for producing a soft resin molded product by injecting a molding material into a molding space formed by a pair of molds, a step of clamping the pair of molds and a mold formed by the pair of molds Injecting the molding material into the space, forming at least the outer peripheral edge of the molded product, and forming a demolding auxiliary portion that protrudes to the side that does not come into contact with one mold when the mold is opened; and opening the pair of molds A part of the periphery of the soft resin molded product is peeled off from the mold surface by applying an external force inward from the outer peripheral direction to the demolding auxiliary portion of the soft resin molded product remaining in one mold. And a step of pressing the mold surface side of the peeled soft resin molded product to demold the soft resin molded product, and a method for producing a soft resin molded product. 2. The method for producing a soft resin molded product according to claim 1, wherein in the step of removing the soft resin molded product, the mold surface side of the soft resin molded product is pressed with compressed air. A plurality of the mold release assisting portions are formed by a mold release assisting portion forming recess formed in the other mold of the mold, and at least one of the mold release assisting portion forming recesses is deeper than the other mold release assisting portion forming recesses. The method for producing a soft resin molded product according to claim 1 or 2, wherein the method is formed.

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