JP2006198954A - Mold and method for producing foamed molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold which can produce a foamed molding having a hole part dented from an outer surface easily without increasing the material cost of the molding and a method for producing the foamed molding using the mold. <P>SOLUTION: A first bag-shaped body 30 is set on the cavity surface of an upper mold 21A, and second and third bag-shaped bodies 31 and 32 are set on the cavity surface of a lower mold 22A facing the upper mold 21A. Each of the bag-shaped bodies 30, 31, and 32 is made of a flexible synthetic resin, a rubber, or the like. A chamber 33 for applying a positive pressure and a negative pressure to the first bag-shaped body 30 is formed in the upper mold 21A, and chambers 34 and 35 for applying a positive pressure and a negative pressure to the second and third bag-shaped bodies 31 and 32 are formed in the lower mold 22A. During molding, the bag-shaped bodies 30, 31, and 32 are expanded to be protruded into a cavity to be a core for forming the hole part 24 dented from the outer surface of a sheet pad 23. During demolding, the bag-shaped bodies 30, 31, and 32 are withered to retreat from the cavity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mold for molding a foam molded body such as a seat pad for a vehicle and a method for manufacturing a foam molded body using the mold, and in particular, it is recessed from an outer surface such as a through hole or a concave portion. The present invention relates to a mold for molding a foam molded article having a hole, and a method for producing a foam molded article using the mold.

  BACKGROUND ART A vehicle seat pad (hereinafter sometimes simply referred to as a seat pad) is generally composed of a foamed molded article such as a flexible polyurethane foam or a semi-rigid polyurethane foam.

  Japanese Patent Laid-Open No. 11-34710 discloses a seating sensor in which a recess is provided to be recessed upward from the bottom surface of a seat pad, and a slab is inserted into the recess, and a sensor is installed on the upper surface portion of the slab. With seats listed.

In order to reduce the weight of the seat pad, it is also conceivable to provide a recessed portion that is recessed upward from the bottom surface of the seat pad and leave the recessed portion hollow (that is, so-called “stealing meat”).
JP 11-34710 A

  As a method of providing such a hole such as a recess or a through hole in a foamed molded product, a method is considered in which a soft core is placed in a mold and molded, and after removing the mold, the core is pulled out from the hole. It has been. However, it is very troublesome to pull out the core after demolding.

  A method is also considered in which this soft core is made hollow, and this core is left as it is in the molded body even after demolding, and the inside of the core is used as a hole. However, the method of leaving the core in this way increases the material cost of the foamed molded product.

  The present invention relates to a mold capable of easily producing a foamed molded article having a hole recessed from the outer surface without increasing the material cost of the foamed molded article, and a foamed molded article using the mold. It aims at providing the manufacturing method of.

  The metal mold of the present invention (Claim 1) is a metal mold for producing a foamed molded article having a hole portion recessed from the outer surface, and a gas inside is formed as a core for forming the hole portion. A bag-like body is provided which expands into a predetermined shape by being filled and protrudes into the mold from the inner wall of the mold and retracts in a non-projecting manner from the inner wall of the mold by withdrawing gas from the inside. It is characterized by being.

  The mold of claim 2 is the mold according to claim 1, wherein the mold is provided with a vent passage communicating with the bag-like body, and a positive pressure applying means for applying a positive pressure to the vent path, and a negative pressure. A negative pressure applying means for applying is provided.

  The mold according to claim 3 is the mold according to claim 1 or 2, wherein the bag-like body is provided on each of the first and second surfaces facing each other on the inner surface of the mold. When the body and the bag-like body on the second surface are inflated, the tips of the bag-like bodies abut on each other.

  The method for producing a foamed molded product according to the present invention (Claim 4) is a method for producing a foamed molded product having a hole that is recessed from the outer surface, wherein the mold according to any one of claims 1 to 3 is used. In use, the bag-shaped body is molded in an expanded state, then the bag-shaped body is deflated, and then demolded.

  According to a fifth aspect of the present invention, there is provided a method for producing a foam molded body according to the fourth aspect, wherein the mold is the mold according to the second aspect, and when removing the mold, a negative pressure is applied to the air passage to form a bag-shaped body. It is characterized by being retracted in the air passage.

  According to a sixth aspect of the present invention, there is provided a method for producing a foam molded article according to the fourth or fifth aspect, wherein the foam molded article is a vehicle seat pad.

  In the mold of the present invention, at the time of molding, the bag-shaped body is inflated and protruded from the inner wall of the mold into the mold, and a core for forming a hole that is recessed from the outer surface of the molded body And At the time of demolding, the bag-like body is deflated and retracted from the mold. Thereby, the operation | work which draws out a core from the inside of a hole part after mold removal becomes unnecessary, and the foaming molding which has a hole part recessedly fitted from an outer surface can be manufactured easily.

  Since the bag-like body is not projected from the inner wall of the mold at the time of demolding, the bag-like body is not caught by the foamed molded body, and the demolding operation can be performed smoothly.

  In addition, since the bag-like body can be used repeatedly without being left in the foam-molded body, the material cost of the foam-molded body does not increase.

  In the metal mold of claim 2, by applying a positive pressure to the air passage, the bag-like body can be expanded and protruded into the metal mold. Further, by applying a negative pressure to the air passage, the bag-like body can be drawn into the air passage and retracted from the inner wall of the mold in a non-projecting manner.

  In the mold according to claim 3, at the time of molding, the bag-like body on the first surface and the bag-like body on the second surface facing each other on the inner surface of the mold are inflated, and the tips of both are brought into contact with each other. By making it, a through-hole can be formed in a foaming molding.

  In the method for producing a foamed molded product of the present invention (Claim 4), by using the mold of the present invention, the foamed molded product having a hole portion recessed from the outer surface can be easily formed. Can be manufactured without increasing the material cost.

  As in claim 5, when the mold of claim 2 is used, after molding, the bag-like body is removed at the time of demolding by applying a negative pressure to the air-flow path and retracting the bag-like body into the air-flow path. The mold can be removed smoothly without being caught by the molded body.

  As described in claim 6, the method for manufacturing a mold and a foamed molded product of the present invention is extremely suitable for manufacturing a vehicle seat pad.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 are longitudinal sectional views of a mold according to an embodiment. FIG. 1 shows a state where the bag-like body is inflated, and FIG. 2 shows a state where the bag-like body is retracted.

  The mold 20A according to this embodiment is a mold for forming a vehicle seat pad. The mold 20A has an upper mold 21A and a lower mold 22A, and a vehicle seat pad is formed by injecting a foaming stock solution such as urethane into a cavity (reference numeral omitted) formed by combining them and foaming. 23 (FIG. 2) is formed. The seat pad 23 has a posture in which the side that becomes the seating surface (upper surface) faces the cavity surface of the lower die 22A and the side that becomes the bottom surface (lower surface) faces the cavity surface of the upper die 21A when commercialized. Molded.

  In this embodiment, the first bag-like body 30 is provided on the cavity surface of the upper mold 21A, and the second and third bag-like bodies 31 and 32 are provided on the cavity surface of the lower mold 22A opposite thereto. It has been. Each of these bag-like bodies 30, 31, and 32 is made of a synthetic resin such as soft polypropylene or silicone resin, rubber, or the like. The upper mold 21A is provided with a chamber 33 for applying a positive pressure and a negative pressure to the first bag-like body 30, and the lower mold 22A has a positive and negative pressure on the second and third bag-like bodies 31, 32. Chambers 34 and 35 are provided for applying pressure and negative pressure.

  In this embodiment, the inner space of the first bag 30 and the inner space of the chamber 33 are located at the center of the cavity surface of the upper mold 21A (near the middle in the left-right direction in FIGS. 1 and 2; hereinafter the same). A ventilation path 36 is provided to communicate with each other. In addition, air passages 37 communicating the internal space of the second bag-like body 31 and the internal space of the chamber 34, respectively, at points spaced approximately equidistant from the center of the cavity surface of the lower mold 22A, respectively. In addition, an air passage 38 that communicates the internal space of the third bag-like body 32 and the internal space of the chamber 35 is provided.

  As shown in FIG. 1, each of the bag-like bodies 30, 31, and 32 has a closed tube shape in which one end (tip) is closed. In addition, the other end (rear end) of each bag-like body 30, 31, 32 is an open end, and a flange portion (reference numeral omitted) projecting radially is provided around the other end. Yes. The other end side of each bag-like body 30, 31, 32 is inserted into the chamber 33, 34, 35 via the corresponding air passage 36, 37, 38. Then, as shown in the figure, the flange portions of the respective bag-like bodies 31, 32, 33 are overlapped with the opening peripheral edge portions leading from the inside of the corresponding chambers 33, 34, 35 to the ventilation paths 36, 37, 38, and fixed members ( Ring) 39, 40, 41.

  The bag-like bodies 30, 31, and 32 are expanded so as to protrude from the air passages 36, 37, and 38 into the cavity when positive pressure is applied from the chambers 33, 34, and 35, respectively. The expanded bag-like body 30 extends vertically downward from the cavity surface of the upper die 21A, and the second and third bag-like bodies 31, 32 respectively extend vertically upward from the cavity surface of the lower die 22A. After that, it bends from the middle and extends toward the center of the cavity (the tip of the bag 30).

  When the bag-like bodies 30, 31, and 32 are completely inflated, they come into contact with each other as shown in FIG.

  In addition, these bag-like bodies 30, 31, and 32 are respectively provided with negative pressure from the chambers 33, 34, and 35 so that the inside of the air passages 36, 37, and 38 (or the chambers 33, 34, 35) and retracts from the cavity.

  When the seat pad 23 is formed using the mold 20A having such a configuration, first, a foaming stock solution such as urethane is supplied to the lower mold 22A, the upper mold 21A is put on and the mold is clamped, and then each bag-like body 30, 31 is formed. , 32 is applied with a positive pressure to be inflated so that the end portions of these bag-like bodies 30, 31, 32 are in contact with each other. Next, the sheet pad 23 is molded by heating and foaming as shown in FIG. Thereafter, a negative pressure is applied to each of the bag-like bodies 30, 31, and 32, the bag-like bodies 30, 31, and 32 are deflated, and further drawn into the air passages 36, 37, and 38. Thereafter, the mold is opened, the seat pad 23 is removed, and a deburring process or the like is performed as necessary, whereby the seat pad 23 product is obtained.

  In the seat pad 23 thus obtained, the portion where the bag-like bodies 30, 31, and 32 that were expanded at the time of molding existed becomes a hole 24 that is recessed from the outer surface of the seat pad 23. . In this embodiment, the bag-like body 30 expanded from the cavity surface of the upper mold 21A and the bag-shaped bodies 31 and 32 expanded from the cavity surface of the lower mold 22A come into contact with each other. , 32 form a series of through-holes that penetrate the seat pad 23.

  In the mold 20A, at the time of molding, the bag-like bodies 30, 31, and 32 are inflated to protrude into the cavity, and are used as cores for forming the hole portions 24 that are recessed from the outer surface of the seat pad 23. At the time of demolding, the bag-like bodies 30, 31, 32 are deflated and retracted from the cavity. Thereby, the operation | work which pulls out a core from the inside of a hole part after mold removal becomes unnecessary, and the seat pad 23 which has the hole part 24 recessedly fitted from an outer surface can be manufactured easily.

  Since the bag-like bodies 30, 31, and 32 are not projected from the inner wall of the cavity at the time of demolding, the bag-like bodies 30, 31, and 32 are not caught by the seat pad 23, and the demolding operation is performed smoothly. be able to.

  Further, since the bag-like bodies 30, 31, and 32 can be used repeatedly without being left in the seat pad 23, the material cost of the seat pad 23 does not increase.

  FIG. 3 is a longitudinal sectional view of a mold according to another embodiment, showing a state in which a bag-like body is inflated.

  In the mold 20B according to this embodiment, a bag-like body 50 is provided on the downward cavity surface of the upper mold 21B. The bag-like body 50 is also made of a synthetic resin such as soft polypropylene or silicon resin, rubber, or the like. A chamber 52 for applying a positive pressure and a negative pressure to the bag-like body 50 is provided on the upper die 21B.

  In this embodiment, when inflated, the bag-like body 50 extends downward from the downward cavity surface of the upper mold 21B, then bends from the middle, and extends toward the center of the cavity.

  Also in this embodiment, the bag-like body 50 is inflated and molded in a state of protruding into the cavity. At the time of demolding, the bag-like body 50 is deflated and retracted from the cavity. The portion where the bag-like body 50 was present becomes a hole that is recessed from the outer surface of the seat pad molded body. In this embodiment, a seating sensor or the like is accommodated in the hole.

  Therefore, even in the mold 20B, it is not necessary to pull out the core from the hole after demolding, and a seat pad having a hole that is recessed from the outer surface can be easily manufactured. In addition, since the bag-like body 50 becomes a non-projecting shape from the inner wall of the cavity at the time of demolding, the bag-like body 50 is not caught by the seat pad and the respective molds 21B and 22B, and the demolding operation can be performed smoothly. . Further, since the bag-like body 50 can be used repeatedly without being left in the seat pad, the material cost of the seat pad does not increase.

  FIG. 4 is a longitudinal sectional view of a mold according to still another embodiment, showing a state where the bag-like body is inflated.

  A mold 20C according to this embodiment includes a first upper mold 21C, a second upper mold 21D, and a lower mold 22C. The second upper mold 21D is disposed near the center above the cavity, and the first upper mold 21C is disposed so as to surround the second upper mold 21D. Both side portions of the second upper mold 21D project into the cavity, and face each other with a distance from the lateral cavity surface of the both sides of the lower mold 22C.

  A bag-like body 60 is provided on the side surface of the projecting portion into the cavity of the second upper mold 21D (the surface facing the lateral cavity surface on the side of the lower mold 22C). Further, a chamber 61 for applying a positive pressure and a negative pressure to the bag-like body 60 is provided at the overhanging portion. This bag-like body 60 is also made of a synthetic resin such as soft polypropylene or silicon resin, rubber, or the like.

  When a positive pressure is applied from the chamber 61 into the bag-like body 60, the bag-like body 60 expands so as to protrude from the side surface of the protruding portion toward the lateral surface of the lower mold 22C. Further, when a negative pressure is applied from the chamber 61 into the bag-like body 60, the bag-like body 60 is drawn into the chamber 61 while being deflated, and becomes non-projecting from the side surface of the overhanging portion.

  Reference numeral 63 denotes a fixing member (ring) in which the rear end portion of the bag-like body 60 is fixed to the side surface of the overhang portion (inlet peripheral edge portion of the chamber 61).

  Also in this embodiment, the bag-like body 60 is inflated and molded in a state of protruding into the cavity. At the time of demolding, the bag-like body 60 is deflated and retracted from the cavity. The portion where the expanded bag-like body 60 was present becomes a hole that is recessed from the outer surface of the seat pad molded body.

  Even in the mold 20C, it is not necessary to pull out the core from the hole after demolding, and a seat pad having a hole recessed from the outer surface can be easily manufactured.

  In this embodiment, the bag-like body 60 is inflated so as to protrude toward the lateral cavity surface from the side surface of the overhanging portion of the second upper mold 21D facing the lateral cavity surface of the side portion of the lower mold 22C. Although a hole is formed, when removing the mold, the bag-like body 60 is deflated so as not to protrude from the side surface of the overhanging portion. Therefore, the bag-like shape is formed in the molded portion between the side surface of the overhanging portion and the lateral cavity surface. The body 60 is not caught and the demolding operation can be performed smoothly.

  Since this bag-like body 60 can also be used repeatedly, the material cost of the seat pad does not increase.

  FIG. 5 is a longitudinal sectional view of a mold according to still another embodiment, and shows a state where the bag-like body is inflated.

  The mold 20C 'according to this embodiment also includes a first upper mold 21C', a second upper mold 21D ', and a lower mold 22C'. Also in this embodiment, the second upper mold 21D ′ is disposed near the center above the cavity, and the first upper mold 21C ′ is disposed so as to surround the second upper mold 21D ′. Has been. Both side portions of the second upper mold 21D 'project into the cavity and face the lateral cavity surfaces on both side portions of the lower mold 22C' with a space therebetween.

  In this embodiment, bag-like bodies 70 and 71 are provided on the laterally facing cavity surfaces on both sides of the lower mold 22C '. In addition, chambers 72 and 73 for applying a positive pressure and a negative pressure to the bag-like bodies 70 and 71 are provided on both sides of the lower mold 22C '. These bag-like bodies 70 and 71 are also made of a synthetic resin such as soft polypropylene or silicon resin, rubber, or the like.

  When positive pressure is applied from the chambers 72 and 73 into the bag-like bodies 70 and 71, the bag-like bodies 70 and 71 are respectively connected to the second upper mold from the lateral cavity surfaces on both sides of the lower mold 22C ′. It expand | swells so that it may protrude toward the left and right overhang | projection part side surface of 21D '. Further, when a negative pressure is applied from the chambers 72 and 73 into the respective bag-like bodies 70 and 71, the bag-like bodies 70 and 71 are drawn into the chambers 72 and 73 while being deflated, respectively. It becomes a non-protruding shape from the sideways cavity surface on both sides of 22C ′.

  Reference numerals 74 and 75 denote fixing members (rings) for fixing the rear end portions of the respective bag-like bodies 70 and 71 to the lateral cavity surfaces (inlet peripheral portions of the chambers 72 and 73) on both sides of the lower mold 22C ′. Is shown.

  Also in this embodiment, each bag-like body 70, 71 is inflated and molded in a state of protruding into the cavity. And at the time of mold removal, each bag-like body 70 and 71 is deflated and evacuated from the inside of the cavity. The portion where the expanded bag-like bodies 70 and 71 existed becomes a hole portion that is recessed from the outer surface of the seat pad molded body.

  Even in the mold 20C ', it is not necessary to pull out the core from the hole after demolding, and the seat pad having the hole recessed from the outer surface can be easily manufactured.

  In this embodiment, the bag-like bodies 70 and 71 are inflated so as to protrude from the lateral cavity surfaces on both sides of the lower die 22C ′ so as to protrude toward the side of the overhanging portion of the second upper die 21D ′ facing them. Although the hole is formed, when removing the mold, the bag-like bodies 70 and 71 are deflated so that they do not protrude from both lateral cavity surfaces. Therefore, when the seat pad is pulled out from the lower mold 22C ′, The bodies 70 and 71 are not caught, and the demolding work can be performed smoothly.

  Also in this embodiment, since the bag-like bodies 70 and 71 can be used repeatedly, the material cost of the seat pad does not increase.

  In addition, the convex part in a metal mold | die can be used also for setting auxiliary materials, such as a felt, a resin clip, and a fastener. Thereby, the repair expense etc. accompanying the breakage / defect of the product by the convex part for submaterial set can be suppressed.

  Each of the above embodiments shows an example of the present invention, and the present invention is not limited to the above embodiment.

It is sectional drawing of the metal mold | die which concerns on embodiment. It is sectional drawing of the state which deflated the bag-like body of the metal mold | die of FIG. It is sectional drawing of the metal mold | die which concerns on embodiment. It is sectional drawing of the metal mold | die which concerns on embodiment. It is sectional drawing of the metal mold | die which concerns on embodiment.

Explanation of symbols

20A, 20B, 20C, 20C 'Die 23 Sheet pad 24 Hole 30, 31, 32, 50, 60, 70, 71 Bag-shaped body 33, 34, 35, 52, 61, 72, 73 Chamber

Claims (6)

A mold for producing a foamed molded article having a hole recessed from the outer surface,
As a core for forming the hole, the inside of the mold expands into a predetermined shape by being filled with gas, protrudes into the mold from the inner wall of the mold, and withdraws the gas from the inside to wither the gold A mold having a bag-like body that is retracted in a non-projecting manner from an inner wall of the mold.   In Claim 1, the mold is provided with a vent path communicating with the bag-like body, and a positive pressure applying means for applying a positive pressure to the vent path and a negative pressure applying means for applying a negative pressure. A mold characterized by being provided.   3. The bag-like body on the first surface and the bag on the second surface, respectively, wherein the bag-like body is provided on the first surface and the second surface of the mold inner surface facing each other. A metal mold characterized in that the tips of the respective bag-like bodies come into contact with each other when the respective shaped bodies are inflated. In the method for producing a foamed molded article having a hole recessed from the outer surface,
Using the mold according to any one of claims 1 to 3,
Perform molding with the bag-like body expanded,
Then deflate the bag,
Thereafter, demolding is carried out, and a method for producing a foamed molded product. In Claim 4, the said metal mold | die is a metal mold | die of Claim 2,
A method for producing a foamed molded article, wherein a negative pressure is applied to the air passage to remove the bag-like body into the air passage when demolding.   6. The method for producing a foam molded body according to claim 4, wherein the foam molded body is a vehicle seat pad.

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