JP2013063630A - Mold, exhaust hole closing member of mold, and method for manufacturing foam molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold that can fully exhaust the gas in the cavity from the exhaust hole outside the cavity when foam molding, and can more certainly prevent entry of the resin foam in the cavity into the exhaust hole, and can improve designability of the foam molded article, and to provide an exhaust hole closing member of the mold and a method for manufacturing the foam molded article.SOLUTION: An exhaust hole closing member 10 has an opening/closing member 11 that can advance or retreat to take the exhaust hole open position by advancing from the exhaust hole 5 of the mold 1 in the cavity 4 and opening the exhaust hole 5 and to take the exhaust hole close position by retreating in the exhaust hole 5 and closing the exhaust hole 5; and a biasing member 12 that biases the opening/closing member 11 to the exhaust hole open position. The biasing member 12 is composed to allow the opening/closing member 11 to retreat to the exhaust hole closed position, when the pressing force is added from the foamed synthetic resin that has been filled in the cavity 4 to the opening/closing member 11 that exists in the exhaust hole open position at the foam molding.

Description

  The present invention relates to a mold for molding a foam molded body such as a seat pad, and relates to a mold provided with an exhaust hole for discharging gas in the cavity to the outside of the cavity during foam molding, In particular, the present invention relates to a mold configured to prevent foam resin in a cavity from entering the exhaust hole during foam molding. The present invention also relates to an exhaust hole closing member provided in the mold for preventing the foamed resin in the cavity from entering the exhaust hole during foam molding. Furthermore, this invention relates to the manufacturing method of the foaming molding using this metal mold | die.

  A foam molded body made of a synthetic foam resin such as polyurethane foam is used for a seat pad constituting a vehicle seat, an interior of a vehicle door, and the like. In the manufacturing process of such a foamed molded article, a release agent is applied to the inner surface of a cavity of a molding die, and then a predetermined amount of a foamed resin raw material for forming a flexible polyurethane foam is supplied into the cavity. And a metal mold | die is clamped and a foaming resin raw material is foam-hardened. The expanded resin raw material fills the cavity while expanding and is molded into a shape corresponding to the cavity. In such a process, when the air existing in the cavity or the gas such as carbon dioxide generated by the foaming reaction is not sufficiently discharged out of the cavity, a defect such as lacking or void may occur in the molded body.

  Therefore, an exhaust hole is provided in the mold to discharge the gas in the cavity. However, simply providing an exhaust hole may cause the foamed resin material filled in the cavity to flow out of the cavity from the exhaust hole, resulting in a loss of material and a need for cleaning the exhaust hole. there were.

  In Patent Document 1 (Japanese Patent Laid-Open No. 2006-192831), a breathable member made of a breathable plate slab or non-woven fabric, to which a non-breathable sheet is attached so as to cover the exhaust hole, is placed in the cavity of the mold. Arrangement is described. In the foam molding process using this mold, the gas in the cavity passes through the air-permeable member and passes between the air-impermeable sheet and the inner surface of the cavity until the resin is filled in the cavity. It flows out of the mold through the exhaust hole. When the foamed resin fills the cavity, the breathable member is pressed against the inner surface of the cavity by the foaming pressure of the foamed resin material, and the exhaust hole is blocked by the non-breathable sheet. This prevents the foamed resin from entering the exhaust hole.

  In the embodiment shown in FIGS. 7 to 10 of Patent Document 1, a protrusion protruding inward of the cavity is provided on the inner surface of the cavity around the exhaust hole. At the time of foam molding, when the air-permeable member is pushed toward the inner surface of the cavity by the foamed resin filled in the cavity, the air-permeable member comes into contact with the protrusion via the non-air-permeable sheet. At this time, the air-permeable member is supported by the protrusion through the air-impermeable sheet, and a gap communicating with the exhaust hole remains between the air-impermeable sheet and the inner surface of the cavity. The gas in the cavity can be discharged out of the cavity through the exhaust hole. After that, when the foaming resin raw material is foamed and cured, and the breathable member is further pressed against the inner surface of the cavity by the foamed resin, the protrusions bite into the breathable member through the non-breathable sheet, and the non-breathable sheet becomes Furthermore, the exhaust hole is closed close to the inner surface of the cavity. This prevents the foamed resin from entering the exhaust hole.

JP 2006-192831 A

  In the embodiment shown in FIGS. 7 to 10 of Patent Document 1, in the foam molding process, the protrusion bites into the air permeable member through the non-breathable member. There is a corresponding recess. Therefore, there exists a possibility that the designability of a foaming molding may fall.

  Further, in the embodiment shown in FIGS. 7 to 10 of Patent Document 1, since the protrusion is disposed around the exhaust hole, the portion of the air-permeable member that overlaps the exhaust hole is not supported by the protrusion. Therefore, if the breathable member is made of a flexible material such as a non-woven fabric, when the breathable member comes into contact with the projection via the non-breathable member, the vent is closer to the exhaust hole than the projection. It may be difficult to separate the non-breathable member from the inner surface of the cavity and leave a gap communicating with the exhaust hole therebetween.

  The present invention can sufficiently discharge the gas in the cavity from the exhaust hole through the exhaust hole during foam molding, and more reliably prevent the foamed resin in the cavity from entering the exhaust hole. A mold capable of improving the design of the foamed molded article and exhaust for preventing the foamed resin in the cavity from entering the exhaust hole provided in the mold. It is an object of the present invention to provide a hole closing member and a method for producing a foam molded body using this mold.

  The metal mold of the present invention (Claim 1) is a metal mold for producing a foam molded body made of a foamed synthetic resin, and the gas in the cavity provided on the inner surface of the cavity of the metal mold is supplied to the cavity. In a mold having an exhaust hole for discharging to the outside of the mold and an exhaust hole closing member for preventing the foamed synthetic resin in the cavity from entering the exhaust hole during foam molding, The member can take an exhaust hole opening position in which the exhaust hole is opened from the exhaust hole to open the exhaust hole, and an exhaust hole closing position in which the exhaust hole is retracted and closed in the exhaust hole. An openable / closable opening / closing member, and a biasing member that biases the opening / closing member to the exhaust hole opening position, and the biasing member is located at the exhaust hole opening position during foam molding. Foam synthesis filled in the cavity for the member When the pressing force of more than predetermined to the backward direction from fat is applied, in which the closing member is characterized by being configured to permit the retreats exhaust stomatal closure position.

  The mold according to claim 2 is the mold according to claim 1, wherein the opening / closing member has a shaft portion inserted through the exhaust hole and a flange portion projecting radially from a distal end side of the shaft portion in the advance direction. The outer diameter of the shaft portion is smaller than the inner diameter of the exhaust hole, and when the opening / closing member is in the exhaust hole open position, the flange portion extends from the exhaust hole to the cavity. It is spaced inward, and the gas in the cavity can be discharged to the outside of the cavity through the flange portion and the shaft portion and the exhaust hole, and the opening and closing member is in the exhaust hole closed position. When retracted, the flange portion is configured to engage with the exhaust hole and close the exhaust hole.

  According to a third aspect of the present invention, the mold according to the second aspect is characterized in that the flange portion has a tapered shape in which an outer diameter becomes smaller toward a rear end side in the advance direction.

  According to a fourth aspect of the present invention, in the metal mold according to any one of the first to third aspects, the urging member includes a spring.

  The mold according to claim 5 is the mold according to any one of claims 1 to 4, wherein the exhaust hole closing member is attached to the mold and includes a holding member that holds the opening and closing member and the biasing member. The holding member is attached to the mold by screwing.

  The manufacturing method of the foaming molding of this invention (Claim 6) manufactures a foaming molding using the metal mold | die of any one of Claim 1 thru | or 5.

  The method for producing a foamed molded article according to claim 7 is the method according to claim 6, wherein the breathable member is disposed in the cavity of the mold so as to cover the exhaust hole, and the breathable member is disposed. After the step, a foam molding step of foaming the foamed synthetic resin raw material in the cavity is performed.

  The method for producing a foamed molded article according to claim 8 is characterized in that, in claim 7, a non-breathable member is arranged on the exhaust hole side of the breathable member so as to face the exhaust hole. is there.

  The method for producing a foamed molded article according to claim 9 is the method according to claim 8, wherein the non-breathable member is attached to the breathable member via a pressure-sensitive adhesive or adhesive, and the pressure-sensitive adhesive or adhesive is The organic solvent is not contained, or the content of the organic solvent in the pressure-sensitive adhesive or adhesive is 0.5% by weight or less.

  According to a tenth aspect of the present invention, there is provided a method for producing a foam molded article according to the eighth or ninth aspect, wherein the non-breathable member is made of pulp or a laminate of pulp and SBR resin.

  The method for producing a foamed molded article according to claim 11 is the sheet-like shape according to any one of claims 8 to 10, wherein the non-breathable member extends along a surface of the breathable member on the exhaust hole side. The non-breathable member has a thickness of 0.05 to 0.2 mm, a tensile strength defined by JIS-Z-0237 of 30 to 90 N / 15 mm, and conforms to JIS-Z-0237. The specified elongation is 1 to 10%.

  According to a twelfth aspect of the present invention, there is provided a method for producing a foamed molded product according to any one of the sixth to eleventh aspects, wherein the foamed molded product is a seat pad.

  According to the present invention (Claim 13), the exhaust hole closing member of the mold is provided on the inner surface of the cavity of the mold for producing a foamed molding made of foamed synthetic resin. In the exhaust hole closing member for preventing the foamed synthetic resin in the cavity from entering the exhaust hole for discharging into the cavity, the exhaust hole closing member advances from the exhaust hole into the cavity. An opening / closing member that can be moved forward and backward so as to be able to take an exhaust hole opening position in which the exhaust hole is opened and an exhaust hole closing position in which the exhaust hole is closed by retreating into the exhaust hole, and the opening / closing member A biasing member biased to the exhaust hole opening position is provided, and the biasing member is a foam filled in the cavity with respect to the opening / closing member at the exhaust hole opening position during foam molding. Pressure is applied from synthetic resin When the one in which the closing member is characterized by being configured to permit the retreats exhaust stomatal closure position.

  In the mold of the present invention (Claim 1), until the foamed resin is filled in the cavity, the opening / closing member of the exhaust hole closing member advances from the exhaust hole into the cavity and opens the exhaust hole. Therefore, the gas in the cavity can be sufficiently discharged from the cavity through the exhaust hole.

  In this mold, when the foamed resin fills the cavity, and the pressing force in the backward direction applied from the foamed resin to the opening / closing member exceeds a predetermined value, the opening / closing member retracts into the exhaust hole and the exhaust hole Will come to close. This prevents the foamed resin from entering the exhaust hole. At this time, since the opening / closing member is retracted into the exhaust hole, there is no room for the foamed resin to enter the exhaust hole, so that it is possible to more reliably prevent the foamed resin from entering the exhaust hole.

  Further, as described above, when the exhaust hole is closed, the opening / closing member retreats into the exhaust hole, so that a concave portion corresponding to the opening / closing member is not formed on the surface of the foam molded body foam-molded by the mold. . Thereby, the design property of a foaming molding can be made favorable.

  According to the second aspect of the present invention, when the opening / closing member is in the exhaust hole open position, the gas in the cavity is sufficiently discharged outside the cavity through the flange portion and the shaft portion of the opening / closing member and the exhaust hole. Is possible. Further, when the opening / closing member is retracted to the exhaust hole closing position, the flange portion engages in the exhaust hole and closes the exhaust hole, so that it is possible to more reliably prevent the foamed resin from entering the exhaust hole. it can.

  As described in claim 3, the flange portion is tapered so that the outer diameter decreases toward the rear end side in the advancing direction, so that the gas in the cavity extends along the outer peripheral surface of the flange portion when the exhaust hole is open. And can smoothly flow into the exhaust hole (between the shaft portion and the exhaust hole).

  As described in claim 4, it is preferable to use a spring as the urging member that urges the opening / closing member to the exhaust hole opening position because it is simple and the control of the urging force is easy.

  According to the fifth aspect of the present invention, since the opening / closing member and the urging member are held by the holding member attached to the mold by screwing, it is relatively easy to perform a large amount of processing on the current mold. The exhaust hole closing member can be installed, and the opening / closing member and the urging member can be removed from the mold relatively easily during maintenance. Therefore, the opening / closing member and the urging member itself and the exhaust hole can be removed. Such maintenance work can be easily performed.

  According to the method for producing a foam molded article of the present invention (Claim 6), since the foam molded article is produced using the mold of the present invention, the gas in the cavity is discharged from the exhaust hole during foam molding as described above. It is possible to sufficiently discharge out of the cavity, and it is possible to more reliably prevent the foamed resin in the cavity from entering the exhaust hole. Moreover, since the recessed part corresponding to the opening-and-closing member of an exhaust hole closing member is not formed in the surface of the foaming molding manufactured by this method, the designability of a foaming molding can be made favorable.

  As described in claim 7, when the air-permeable member is disposed in the cavity of the mold so as to cover the exhaust hole prior to the foam molding step, the open / close member of the exhaust hole closing member is exhausted in the exhaust hole open state. Since the air enters the cavity from the hole, even if the breathable member is made of a flexible material such as a nonwoven fabric, the pressing force applied in the backward direction is applied to the opening and closing member after the foamed resin reaches the breathable member. Until the air pressure exceeds a predetermined value, the air-permeable member can be more reliably separated from the exhaust hole, and a gap communicating with the air-exhaust hole can be secured between the air-permeable member and the inner surface of the cavity of the mold. . Thereby, the gas in the cavity can be sufficiently discharged out of the cavity after the foamed resin reaches the air-permeable member and before the exhaust hole is closed.

  As described in claim 8, by disposing a non-breathable member on the exhaust hole side of the breathable member so as to face the exhaust hole, gas in the cavity permeates the breathable member in the foam molding process. Thus, it is possible to effectively prevent the foamed resin from being impregnated into the breathable member as it flows out of the exhaust hole. Thereby, effects such as prevention of rubbing noise generated when the foamed molded product is used when the foamed resin is impregnated into the air-permeable member and weight reduction of the foamed molded product are exhibited.

  Volatile organic compounds (VOC) such as formaldehyde, toluene, and xylene cause sick house syndrome and chemical sensitivity. There is a need to not dissipate as much as possible. In order to meet this requirement, according to the present invention, when the non-breathable member is attached to the breathable member with a pressure-sensitive adhesive or adhesive, an organic solvent is contained as the pressure-sensitive adhesive or adhesive. It is preferable to use those that are not present, or those in which the content of the organic solvent in the pressure-sensitive adhesive or adhesive is 0.5% by weight or less. By using such a pressure-sensitive adhesive or adhesive, substantially no or almost no volatile organic compound is generated from the pressure-sensitive adhesive or adhesive. Therefore, the foam produced using the breathable member with the non-breathable member is used. It is possible to more reliably prevent or suppress the emission of volatile organic compounds from the molded body.

  In the present invention, the pressure-sensitive adhesive is disposed between the air-permeable member and the non-air-permeable member, and refers to a material that adheres them only by applying pressure. The adhesive is moisture-cured, This means that these are bonded together with solvent volatilization, chemical reaction, and the like.

  As described in claim 10, the non-breathable member is preferably made of pulp or a laminate of pulp and SBR (styrene-butadiene rubber) resin. By configuring the non-breathable member with such a material, the non-breathable member can be made more flexible. Thereby, when the foamed resin is filled in the cavity of the mold, the non-breathable member easily has a shape along the inner surface of the cavity. Therefore, the outer shape accuracy of the foam molded body molded in the cavity, and Further, the mold exhaust hole can be closed well by the non-breathable member.

  As described in claim 11, the non-breathable member is a sheet-like member extending along the surface on the exhaust hole side of the breathable member, has a thickness of 0.05 to 0.2 mm, and is JIS-Z. The tensile strength and elongation defined by −0237 are preferably 30 to 90 N / 15 mm and 1 to 10%, respectively. By making the non-breathable member like this, the non-breathable member becomes more excellent in followability to the inner shape of the cavity and resists the pressing force from the foamed resin in the cavity. Since the closed state of the exhaust hole of the mold can be maintained firmly, the outer shape accuracy of the foamed molded product and the closeability of the exhaust hole of the mold by the non-breathable member can be further improved. .

  As claimed in claim 12, the present invention is suitable for application to a seat pad manufacturing method.

  In the exhaust hole closing member of the present invention (Claim 13), until the foamed resin fills the cavity of the mold, the opening / closing member extends from the exhaust hole of the mold into the cavity and the exhaust hole Therefore, the gas in the cavity can be sufficiently discharged out of the cavity from the exhaust hole.

  In this exhaust hole closing member, when the foamed resin fills the cavity of the mold and the pressing force in the backward direction applied from the foamed resin to the opening / closing member exceeds a predetermined value, the opening / closing member is exhausted from the mold. Retreats into the hole and closes the exhaust hole. This prevents the foamed resin from entering the exhaust holes of the mold. At this time, since the opening / closing member is retracted into the exhaust hole, there is no room for the foamed resin to enter the exhaust hole, so that it is possible to more reliably prevent the foamed resin from entering the exhaust hole.

  In this way, when the exhaust hole of the mold is closed, the opening / closing member retreats into the exhaust hole, so that a recess corresponding to the opening / closing member is formed on the surface of the foam molded body foam-molded by the mold. Is not formed. Thereby, the design property of a foaming molding can be made favorable.

It is sectional drawing of the metal mold | die which concerns on 1st Embodiment. It is a block diagram of the exhaust-hole closing member provided in the metal mold | die of FIG. It is an expanded sectional view of the III part of FIG. It is sectional drawing of the part similar to FIG. 3 which shows the middle of a foam molding process. It is sectional drawing of the same part as FIG. 3 which shows the time of completion | finish of a foam molding process. It is sectional drawing which shows the middle of the foam molding process by the manufacturing method of the foaming molding which concerns on 2nd Embodiment. It is sectional drawing which shows the middle of the foam molding process by the manufacturing method of the foaming molding of FIG. It is sectional drawing which shows the time of completion | finish of the foam molding process by the manufacturing method of the foaming molding of FIG. It is a block diagram of the exhaust-hole closing member which concerns on 3rd Embodiment. It is an exploded sectional view of a reinforcing material with a non-breathable sheet.

  Embodiments will be described below with reference to the drawings. The following embodiments show examples of applying the present invention to a mold for manufacturing a seat pad, an exhaust hole closing member of the mold, and a method of manufacturing a seat pad using the mold. However, the present invention is also applicable to a mold for manufacturing a foam molded body other than a seat pad, an exhaust hole closing member of the mold, and a method for manufacturing a foam molded body using the mold. It is.

[First Embodiment]
FIG. 1 is a sectional view of a mold according to the first embodiment. FIG. 2 (a) is a perspective view of an exhaust hole closing member provided in the mold. FIG. 2 (b) is a cross-sectional view taken along line BB in FIG. 2 (a), and shows a state where the opening / closing member of the exhaust hole closing member is in the exhaust hole open position (exhaust hole open state). ing. FIG. 2 (c) is a cross-sectional view of the same portion as FIG. 2 (b), showing a state where the opening / closing member of the exhaust hole closing member is in the exhaust hole closed position (exhaust hole closed state). FIG. 3 is an enlarged cross-sectional view of a portion III in FIG. 1, showing a state in the middle of the foam molding process and before the foamed resin presses the opening / closing member. FIG. 4 is a cross-sectional view of the same part as in FIG. 3, showing a state where the foamed resin is pressing the opening / closing member in the middle of the foam molding process. FIG. 5 is a cross-sectional view of the same part as in FIG. 3, showing the end of the foam molding process.

  In this embodiment, the mold 1 is for manufacturing a seat pad constituting a vehicle seat. The seat pad is made of a foamed synthetic resin such as polyurethane foam. That is, this seat pad corresponds to the foamed molded article of claim 1. In this embodiment, the seat pad is a cushion pad that constitutes a seat portion of a vehicle seat, but the present invention is also applicable to a back pad that constitutes a backrest portion of a vehicle seat. FIG. 1 shows a vertical cross section along the front-rear direction (hereinafter simply referred to as the front-rear direction) when the seat pad (cushion pad) formed by the mold 1 is used.

  In this embodiment, as shown in FIG. 1, the mold 1 has an upper mold 2 and a lower mold 3, and gas in a cavity 4 surrounded by the upper mold 2 and the lower mold 3 is placed outside the cavity 4. An exhaust hole 5 for discharging and an exhaust hole closing member 10 for preventing the foamed synthetic resin in the cavity 4 from entering the exhaust hole 5 during foam molding are provided. The mold 1 may further have a core mold (not shown). The upper mold 2 and the lower mold 3 are matched with each other at their peripheral portions. 1 indicates a parting line between the upper mold 2 and the lower mold 3. During foam molding, the gas in the cavity 4 is also discharged from the parting line P.

  In this embodiment, the exhaust hole 5 is provided on the center side of the cavity inner surface of the upper mold 2 with respect to the parting line P. The exhaust hole 5 has, for example, a portion that is higher than the parting line P in the cavity inner surface of the upper mold 2 or a portion that is lower than the parting line P between the parting line P and the exhaust hole 5. It is disposed in a portion where gas is difficult to escape only from the parting line P at the time of foam molding, such as a portion that performs. In FIG. 1, two exhaust holes 5 arranged at intervals in the front-rear direction of the seat pad are illustrated, but the number and arrangement of the exhaust holes 5 are not limited to this. In addition, the exhaust hole 5 may be provided also in the lower mold | type 3 etc. as needed. Each exhaust hole 5 is provided with an exhaust hole closing member 10.

  In the cavity 4 of the mold 1, the seat pad is foam-molded with the seating surface facing downward. That is, the seat surface of the seat pad is formed by the cavity inner surface of the lower mold 3, and the side surface (hereinafter referred to as the back surface) opposite to the seat surface of the seat pad is formed by the cavity inner surface of the upper mold 2. A reinforcing material 6 is provided on the back surface of the seat pad. In this embodiment, the reinforcing material 6 is made of a breathable material such as a nonwoven fabric. That is, in this embodiment, the reinforcing member 6 corresponds to the breathable member of claim 7. Prior to the foam molding process of the seat pad, the reinforcing material 6 is disposed along the inner surface of the cavity of the upper mold 2 and is fixed to the upper mold 2 by a fixing tool (not shown) such as a pin or a magnet. At this time, each exhaust hole 5 is covered with the reinforcing material 6.

  The exhaust hole closing member 10 advances from the exhaust hole 5 into the cavity 4 to open the exhaust hole 5, and the exhaust hole closed position retracts into the exhaust hole 5 to close the exhaust hole 5. And an opening / closing member 11 that can be advanced and retracted, and an urging member 12 that urges the opening / closing member 11 to the exhaust hole opening position.

  In this embodiment, the exhaust hole closing member 10 further includes a holding member 13 that holds the opening / closing member 11 and the biasing member 12. As shown in FIG. 2 (a), in this embodiment, the holding member 13 has a substantially cylindrical shape having an inner hole 13a. A male screw portion 14 is provided around the outer peripheral surface of one end side (hereinafter referred to as the front end side) of the holding member 13 in the cylinder axis direction. As shown in FIGS. 3 to 5, a female screw hole 7 into which the male screw portion 14 is screwed is provided at the closing member mounting position of the upper die 2, and the male screw portion 14 is screwed into the female screw hole 7. Thus, the holding member 13 is attached to the upper mold 2.

  In this embodiment, as shown in FIGS. 3 to 5, the female screw hole 7 passes through the upper mold 2, and the end surface on the front end side of the holding member 13 (hereinafter referred to as the front end surface) through the female screw hole 7. Faces the cavity 4. The holding member 13 is screwed into the female screw hole 7 so that the front end surface thereof is substantially flush with the cavity inner surface of the upper mold 2 around the female screw hole 7.

  In this embodiment, the inner hole 13 a of the holding member 13 is open to the front end surface of the holding member 13, and the opening of the inner hole 13 a on the front end surface of the holding member 13 is the exhaust hole 5. . On the other end side (hereinafter referred to as the rear end side) of the holding member 13 in the cylinder axis direction, the inner hole 13a is closed. In this embodiment, the forward / backward movement of the opening / closing member 11 is guided from an end surface on the rear end side of the inner hole 13a (hereinafter simply referred to as a rear end surface) into the inner hole 13a substantially coaxially with the inner hole 13a. A guide pin 16 is projected. A communication port 15 that communicates the inner hole 13 a and the outside of the holding member 13 (that is, the outside of the cavity 4) is provided on the outer peripheral surface of the holding member 13 on the rear end side of the male screw portion 14. In this embodiment, a plurality of communication ports 15 are provided at intervals in the circumferential direction of the holding member 13. The gas flowing into the exhaust hole 5 from the inside of the cavity 4 is discharged to the outside of the cavity 4 through the inner hole 13 a and the communication port 15 of the holding member 13. In addition, the structure of the holding member 13 and the formation method of the exhaust hole 5 are not limited to this. The holding member 13 may be attached to the upper mold 2 by a method other than screwing (for example, elastic engagement between the holding member 13 and the upper mold 2). The opening / closing member 11 and the biasing member 12 may be directly attached to the mold 1 without using the holding member 13.

  In this embodiment, the opening / closing member 11 includes a shaft portion 11a inserted into the inner hole 13a of the holding member 13 through the exhaust hole 5, and a distal end side of the shaft portion 11a in the advance direction (= the holding member 13). A flange portion 11b projecting radially from the distal end side (hereinafter simply referred to as the distal end side). A guide hole 11c (FIG. 2 (b) in which a guide pin 16 is fitted in the rear end side (= the rear end side of the holding member 13, hereinafter simply referred to as the rear end side) of the shaft portion 11a. ), (C)). The shaft portion 11 a advances and retreats along the guide pin 16. In this embodiment, the urging member 12 is formed of a coil spring and is disposed so as to surround the guide pin 16, and in the accumulated state (compressed state), one end side in the axial center direction is the rear end surface of the shaft portion 11 a. The other end is in contact with the rear end surface of the inner hole 13a.

  In this embodiment, the inner hole 13a of the holding member 13 has a substantially circular cross-sectional shape in the direction perpendicular to the cylinder axis direction, and has an inner diameter over the entire length in the cylinder axis direction (that is, up to the exhaust hole 5). Is almost constant. The shaft portion 11a has a substantially circular cross-sectional shape in the direction orthogonal to the axial direction, and the outer diameter is substantially constant over the entire length in the axial direction. The outer diameter of the shaft portion 11 a is smaller than the inner diameter of the inner hole 13 a of the holding member 13. The inner diameter of the inner hole 13a of the holding member 13 (that is, the inner diameter of the exhaust hole 5) is preferably 5 to 15 mm, particularly 5 to 8 mm, and the outer diameter of the shaft portion 11a is 3 to 10 mm, particularly 4 to 7 mm. preferable.

  In this embodiment, when the opening / closing member 11 is in the exhaust hole open position, as shown in FIGS. 2 (b) and 3, the flange portion 11b is separated from the exhaust hole 5 to the inside of the cavity 4, The gas in the cavity 4 can be discharged to the outside of the cavity 4 through the flange portion 11b and the shaft portion 11a and the exhaust hole 5 (exhaust hole open state).

  In this embodiment, as shown in FIGS. 2 (b) and 2 (c), the flange portion 11b has a tapered shape whose outer shape becomes smaller toward the rear end side. The front end surface of the flange portion 11b has a substantially circular plan view shape corresponding to the opening shape of the exhaust hole 5, as shown in FIG. In this embodiment, the front end surface of the flange 11 b is a flat surface substantially parallel to the inner surface of the cavity of the upper mold 2 around the exhaust hole 5. The angle θ (FIG. 2 (b)) formed by the front end surface of the flange portion 11b and the tapered outer peripheral surface is preferably 30 to 80 °, particularly 55 to 75 °. Thus, by making the outer peripheral surface of the flange portion 11b tapered, in the above exhaust hole open state, the gas in the cavity 4 can be smoothly exhausted along the outer peripheral surface of the flange portion 11b (the shaft portion 11a). And between the exhaust holes 5).

  In this exhaust hole open state, the distance from the cavity inner surface of the upper mold 2 around the exhaust hole 5 to the front end surface of the flange portion 11b (amount of protrusion of the opening / closing member 11 from the cavity inner surface) T (FIG. 2 (b)) Is preferably 1 to 10 mm, particularly 2 to 8 mm.

  As shown in FIGS. 4 and 5, the urging member 12 fills the cavity 4 with respect to the opening / closing member 11 (in this embodiment, the front end surface of the flange portion 11b) at the exhaust hole opening position during foam molding. The opening / closing member 11 is allowed to retreat to the exhaust hole closing position when a predetermined pressing force or more is applied in the backward direction from the foamed resin via the reinforcing member 6. In other words, the urging member 12 does not allow the opening / closing member 11 to be retracted at a gas pressure at which gas in the cavity 4 passes through the reinforcing material 6 and flows into the exhaust hole 5. In this way, the urging force of the urging member 12 for operating the opening / closing member 11 can be obtained by experiment, simulation, or the like. As in this embodiment, it is convenient and preferable to use a coil spring as the biasing member 12. By appropriately selecting the spring constant of the coil spring, the urging force of the urging member 12 can be easily controlled. In the manufacture of a general vehicle seat pad, the spring constant of the coil spring is preferably 0.02 to 0.40 N / mm, particularly 0.05 to 0.30 N / mm. The urging member 12 may be configured by an urging means other than a spring.

  When the opening / closing member 11 is retracted to the exhaust hole closing position, as shown in FIGS. 2 (c) and 5, the flange portion 11b is engaged with the exhaust hole 5, and the exhaust hole 5 is closed by the flange portion 11b. State (exhaust hole closed state).

  In the exhaust hole closed state in which the flange portion 11b is engaged with the exhaust hole 5, the space between the inner peripheral surface of the exhaust hole 5 and the outer peripheral edge of the flange portion 11b may not necessarily be sealed. There may be a slight gap (preferably enough to prevent the foamed resin from entering between them). Specifically, the outer diameter of the front end surface of the flange portion 11b is preferably an inner diameter of the exhaust hole 5 of −0.2 to 1.0 mm, particularly an inner diameter of the exhaust hole 5 of −0.3 to 0.6 mm.

  In this embodiment, as shown in FIGS. 2 (c) and 5, when the opening / closing member 11 is retracted to the exhaust hole closed position, the tip surface of the flange portion 11 b is the upper mold 2 around the exhaust hole 5. It is configured to be in a state of being retracted (retracted) into the exhaust hole 5 from the inner surface of the cavity. The distance between the front end surface of the flange portion 11b and the cavity inner surface of the upper mold 2 around the exhaust hole 5 when the opening / closing member 11 is in the exhaust hole closed position (retraction amount of the flange portion 11b from the cavity inner surface) D 2 (c)) is preferably 0.0 to 5.0 mm, particularly preferably 0.0 to 2.0 mm. By comprising in this way, the sealing performance between the exhaust hole 5 and the flange part 11b in an exhaust hole closed state can be improved.

  Next, a procedure for manufacturing a seat pad using the mold 1 will be described.

  First, the upper mold 2 and the lower mold 3 are opened, the reinforcing material 6 is disposed along the inner surface of the cavity of the upper mold 2, and is fixed to the upper mold 2 by the fixture (breathable member arranging step). . At this time, as shown in FIGS. 1 and 3, the opening / closing members 11 of the exhaust hole closing members are located at the exhaust hole opening positions extending from the exhaust holes 5 to the inside of the cavity 4. The portions overlapping the holes 5 and the periphery thereof are respectively pushed by the opening / closing members 11 of the exhaust hole closing members 10 and separated from the cavity inner surface of the upper mold 2.

  Next, the foamed synthetic resin raw material is injected into the lower mold 3, the lower mold 3 and the upper mold 2 are clamped, and the foamed synthetic resin raw material is heated and foamed (foam molding process). The foamed resin U formed by foaming this raw material fills the cavity 4 toward the cavity inner surface (reinforcing material 6) of the upper mold 2 as shown in FIGS. As a result, the seat pad is molded, and the reinforcing material 6 is integrated with the back surface of the seat pad.

  In this foam molding step, the pressing force in the backward direction applied to each opening / closing member 11 is not less than a predetermined value before the foamed resin U reaches the reinforcing material 6 and after the foamed resin U reaches the reinforcing material 6. Until this time, as shown in FIGS. 3 and 4, each exhaust hole 5 is open. As a result, the gas in the cavity 4 passes through the reinforcing member 6, and communicates between the flange portion 11 b and the shaft portion 11 a of the opening / closing member 11 and the exhaust hole 5 (inner hole 13 a of the holding member 13) and the holding member 13. It is discharged to the outside of the cavity 4 through the mouth 15. The gas in the cavity 4 is also discharged from the parting line P to the outside of the cavity 4. Thereby, the gas in the cavity 4 is sufficiently discharged to the outside of the cavity 4, and it is possible to prevent molding defects such as voids from occurring in the seat pad.

  As shown in FIGS. 4 to 5, after the foamed resin U reaches the reinforcing member 6, when the pressing force applied to each opening / closing member 11 in the backward direction becomes a predetermined value or more, each opening / closing member 11 closes the exhaust hole. The exhaust holes 5 are closed by the respective opening / closing members 11. This prevents the foamed resin U from entering each exhaust hole 5.

  After the foamed resin U is cured, the mold is opened to release the seat pad. Thereafter, the surface of the seat pad is finished as necessary to complete the seat pad.

  The mold 1 provides the following operational effects.

  In this mold 1, until the foamed resin is sufficiently filled in the cavity 4, the opening / closing member 11 of the exhaust hole closing member 10 advances from the exhaust hole 5 into the cavity 4 to open the exhaust hole 5. Therefore, the gas in the cavity 4 can be sufficiently discharged out of the cavity 4 from the exhaust hole 5.

  In the mold 1, when the exhaust hole is open, the opening / closing member 11 has advanced from the exhaust hole 5 into the cavity 4, so that the reinforcing member 6 as a breathable member is flexible like a nonwoven fabric. Even when the material is made of any material, the reinforcing material 6 can be exhausted more reliably until the pressing force in the backward direction applied to each opening / closing member 11 after the foamed resin U reaches the reinforcing material 6 becomes a predetermined value or more. It is possible to secure a gap communicating with the exhaust hole 5 between the reinforcing member 6 and the inner surface of the cavity of the upper mold 2 by separating from the hole 5. Thereby, even after the foamed resin U reaches the reinforcing member 6, the gas in the cavity 4 can be more sufficiently discharged out of the cavity 4.

  In the mold 1, when the foamed resin U reaches the reinforcing material 6 and the pressing force applied in the backward direction from the foamed resin to the opening / closing member 11 exceeds a predetermined value, the opening / closing member 11 is exhausted. Retreating into the hole 5 and closing the exhaust hole 5 eliminates room for the foamed resin U to enter the exhaust hole 5 and more reliably prevents the foamed resin U from entering the exhaust hole 5. Can do.

  Further, as described above, when the exhaust hole 5 is closed, the opening / closing member 11 is retracted into the exhaust hole 5, so that the surface of the seat pad foam-molded by the mold 1 corresponds to the opening / closing member 11. A recess is not formed. Thereby, the design property of a seat pad can be made favorable.

[Second Embodiment]
FIG. 6 is a cross-sectional view showing a state before the foaming resin presses the opening / closing member in the middle of the foam molding process by the method for producing a foam molded body according to the second embodiment. FIG. 7 is a cross-sectional view showing a state where the foamed resin is pressing the opening / closing member in the middle of the foam molding process by the method for producing the foam molded article. FIG. 8 is a cross-sectional view showing the end of the foam molding process according to the method for producing the foam molded article. 6 to 8 show the same parts as those in FIGS.

  In this embodiment, a non-breathable sheet 8 made of a non-breathable material is provided on the surface of the reinforcing material 6 on the side of the exhaust hole 5 in the region overlapping the cavity inner surface of each exhaust hole 5 and the upper mold 2 in the vicinity thereof. Is provided. As the non-breathable material constituting the non-breathable sheet 8, a PET film with an adhesive, a paper tape with an adhesive, a PP film with an adhesive, and the like are suitable. The non-breathable sheet 8 preferably has a size that covers the reinforcing member 6 from the center of each exhaust hole 5 over a radius of 15 to 40 mm, particularly 20 to 30 mm.

  The non-breathable sheet 8 is preferably made of a material that can be deformed relatively flexibly along the inner surface of the mold 1 when pressed by the foamed resin expanded in the mold 1. For example, the non-breathable sheet 8 is preferably made of pulp or a laminate of pulp and SBR resin. When the non-breathable sheet 8 is made of pulp or a laminate of pulp and SBR resin, the non-breathable sheet 8 is excellent in flexibility and easy to handle (for example, in a roll like a tape). The ease of work when drawing and cutting a predetermined length from the wound state is also good, and rubbing noise is less likely to occur.

  In this embodiment, as shown in FIG. 10, the air-impermeable sheet 8 includes a sheet-like base material 8a, and an adhesive layer 8b formed on one surface of the base material 8a (reinforcing material 6 side). And a coating layer 8c formed on the other surface (exhaust hole 5 side) of the substrate 8a. In addition, the structure of the air-impermeable sheet 8 is not limited to this. For example, the base material 8a may be made of pulp, and the covering layer 8c may be made of SBR resin. As the base material 8a made of pulp, for example, Japanese paper is suitable. In addition, the material of the base material 8a and the coating layer 8c is not limited to this.

  The base material 8a itself may be air permeable, and in this case, air permeability may be imparted by at least one of the pressure-sensitive adhesive layer 8b and the coating layer 8c covering the surface of the base material 8a. When non-breathability is imparted by the pressure-sensitive adhesive layer 8b, the coating layer 8c may be omitted. The substrate 8a itself may be non-breathable. When the non-breathable sheet 8 is shipped in the state of being wound in a roll like a tape, the coating layer 8c is provided for imparting peelability from the pressure-sensitive adhesive layer 8b. It may be. An adhesive layer may be formed instead of the pressure-sensitive adhesive layer 8b.

  As a pressure-sensitive adhesive or adhesive for adhering the non-breathable sheet 8 to the reinforcing material 6, one that does not contain an organic solvent or one that has an organic solvent content of 0.5% by weight or less is used. Is preferred. As such a pressure-sensitive adhesive or adhesive, for example, hot melt, emulsion pressure-sensitive adhesive and the like are suitable.

  The thickness of the air-impermeable sheet 8 is preferably 0.05 to 0.20 mm, particularly 0.05 to 0.15 mm. The non-breathable sheet 8 preferably has a tensile strength defined by JIS-Z-0237 of 30 to 90 N / 15 mm, particularly 40 to 60 N / 15 mm. The non-breathable sheet 8 preferably has an elongation percentage defined by JIS-Z-0237 of 1 to 10%, particularly 2 to 5%.

  The configuration of the mold 1 in this embodiment is the same as that in the first embodiment. In addition, in the method of manufacturing the seat pad using the mold 1, in the air permeable member arranging step, as shown in FIGS. Except that the reinforcing material 6 is arranged so as to overlap with the first embodiment, it is the same as the first embodiment.

  In this embodiment, a non-breathable sheet 8 is provided on the surface of the reinforcing member 6 on the side of the exhaust hole 5 in the region overlapping the exhaust hole 5 and the cavity inner surface of the upper mold 2 around it. Therefore, it is possible to effectively prevent the foamed resin U from being impregnated into the reinforcing material 6 as the gas in the cavity 4 permeates the reinforcing material 6 and flows out from the exhaust holes 5 in the foam molding process. Can do. As a result, the reinforcing material 6 is impregnated with the foamed resin U, and effects such as prevention of rubbing noise generated when the seat pad is used and weight reduction of the seat pad are exhibited.

  In this embodiment, the non-breathable sheet 8 is made of pulp or a laminate of pulp and SBR resin, and is excellent in flexibility. Therefore, when the foamed resin U is filled in the cavity 4, The breathable sheet 8 can be easily formed along the inner surface of the cavity 4. Thereby, the outer shape accuracy of the seat pad molded in the cavity 4 and the closing property of each exhaust hole 5 by the non-breathable sheet 8 can be improved.

  Moreover, in this embodiment, the non-breathable sheet 8 is a sheet-like thing extended along the surface at the side of the exhaust hole 5 of the reinforcement 6, and thickness is 0.05-0.2 mm. Since the tensile strength and elongation defined by JIS-Z-0237 are 30 to 90 N / 15 mm and 1 to 10%, respectively, the non-breathable sheet 8 is more excellent in followability to the inner surface shape of the cavity 4. In addition, since the closed state of each exhaust hole 5 can be firmly maintained against the pressing force from the foamed resin U in the cavity 4, the outer shape accuracy and non-breathability of the seat pad can be maintained. The closing property of each exhaust hole 5 by the seat 8 can be further improved.

  In this embodiment, the pressure-sensitive adhesive or adhesive for attaching the air-impermeable sheet 8 to the reinforcing material 6 does not contain an organic solvent, or the organic solvent content is 0.5% by weight or less. Therefore, substantially no or almost no volatile organic compound is generated from this pressure-sensitive adhesive or adhesive. Thereby, emission of the volatile organic compound from the seat pad can be prevented or suppressed more reliably.

[Third Embodiment]
FIGS. 9 (a) and 9 (b) are configuration diagrams of an exhaust hole closing member according to the third embodiment. FIG. 9 (a) shows an exhaust hole open state, and FIG. 9 (b). The exhaust hole closed state is shown. 9 (a) and 9 (b) are shown in the same cross section as in FIGS. 2 (b) and 2 (c).

  The exhaust hole closing member 10A in this embodiment includes a seal member 11d for sealing between the flange portion 11b ′ of the open / close member 11A and the exhaust hole 5 when the open / close member 11A is in the exhaust hole closed position. ing.

  In this embodiment, as shown in FIG. 9 (a), the flange portion 11b 'has a disk shape larger in diameter than the exhaust hole 5, and a seal member 11d is disposed on the upper surface of the flange portion 11b'. ing. When the opening / closing member 11A is retracted to the exhaust hole closing position, as shown in FIG. 9B, the flange portion 11b ′ overlaps with the peripheral edge portion of the exhaust hole 5 through the seal member 11d, and the flange portion 11b is sealed by the seal member 11d. The space between 'and the peripheral edge of the exhaust hole 5 is sealed (sealed). The seal member 11d may be provided at the peripheral edge of the exhaust hole 5 or may be provided at both the upper surface of the flange portion 11b 'and the peripheral edge of the exhaust hole 5.

  As the seal member 11d, for example, an O-ring or a rubber washer is simple and preferable. The material of the seal member 11d is preferably silicon rubber, nitrile rubber, fluorine rubber, ethylene propylene rubber, or the like. The configuration of the seal member 11d is not limited to this.

  The other structure of the exhaust hole closing member 10A is the same as that of the exhaust hole closing member 10 in the first embodiment, and FIGS. 9 (a) and 9 (b) show FIGS. The same reference numerals denote the same parts.

  In the exhaust hole closing member 10A, when the opening / closing member 11A is retracted to the exhaust hole closing position, the gap between the flange portion 11b ′ of the opening / closing member 11A and the exhaust hole 5 is sealed by the seal member 11d. Intrusion of the foamed resin into the exhaust hole 5 at the time of molding can be prevented more reliably.

  Each of the above embodiments is an example of the present invention, and the present invention may have a configuration other than that illustrated.

  For example, each of the above embodiments shows an application example of the present invention to a seat pad, but the present invention can also be applied to a foam molded body other than the seat pad.

1 Mold 2 Upper mold 3 Lower mold 4 Cavity 5 Exhaust hole 6 Reinforcing material (breathable member)
7 Female screw hole 8 Non-breathable sheet 8a Base material 8b Adhesive layer (or adhesive layer)
8c Covering layer 10, 10A Exhaust hole closing member 11, 11A Opening / closing member 11a Shaft portion 11b, 11b 'Flange portion 11d Seal member 12 Energizing member 13 Holding member 14 Male screw portion 15 Communication port 16 Guide pin

Claims (13)

A mold for producing a foam molded body made of a synthetic foam resin,
An exhaust hole provided on the cavity inner surface of the mold for exhausting the gas in the cavity to the outside of the cavity;
In a mold having an exhaust hole closing member for preventing the foamed synthetic resin in the cavity from entering the exhaust hole during foam molding,
The exhaust hole closing member is:
The exhaust hole can be moved forward and backward so as to be able to take an exhaust hole opening position where the exhaust hole is opened from the exhaust hole to open the exhaust hole, and an exhaust hole closed position where the exhaust hole is closed by retreating into the exhaust hole. An opening and closing member, and
A biasing member that biases the opening / closing member to the exhaust hole opening position;
The biasing member is formed when a pressing force of a predetermined value or more is applied in the backward direction from the foamed synthetic resin filled in the cavity to the opening / closing member at the exhaust hole opening position during foam molding. The mold is configured to allow the opening / closing member to retract to the exhaust hole closing position. In Claim 1, the opening and closing member has a shaft portion inserted through the exhaust hole, and a flange portion projecting radially from the distal end side of the shaft portion in the advance direction,
The outer diameter of the shaft portion is smaller than the inner diameter of the exhaust hole,
When the opening / closing member is in the exhaust hole open position, the flange portion is separated from the exhaust hole to the inside of the cavity, and passes between the flange portion and the shaft portion and the exhaust hole, so that Gas can be discharged outside the cavity,
A mold characterized in that, when the opening / closing member is retracted to the exhaust hole closing position, the flange portion is engaged with the exhaust hole to close the exhaust hole.   3. The mold according to claim 2, wherein the flange portion has a tapered shape in which an outer diameter decreases toward a rear end side in the advance direction.   4. The mold according to claim 1, wherein the urging member comprises a spring. 5. The exhaust hole closing member according to claim 1, wherein the exhaust hole closing member includes a holding member that is attached to the mold and holds the opening and closing member and the biasing member.
The mold, wherein the holding member is attached to the mold by screwing.   The manufacturing method of a foaming molding which manufactures a foaming molding using the metal mold | die of any one of Claim 1 thru | or 5. The air permeable member arrangement step according to claim 6, wherein an air permeable member is arranged in the cavity of the mold so as to cover the exhaust hole;
A method for producing a foam molded article, comprising performing a foam molding step of foaming a foamed synthetic resin raw material in the cavity after the breathable member arranging step.   8. The method for producing a foamed molded article according to claim 7, wherein a non-breathable member is disposed on the exhaust hole side of the breathable member so as to face the exhaust hole. In claim 8, the non-breathable member is attached to the breathable member via an adhesive or an adhesive,
The pressure-sensitive adhesive or adhesive does not contain an organic solvent, or the content of the organic solvent in the pressure-sensitive adhesive or adhesive is 0.5% by weight or less. Production method.   10. The method for producing a foamed molded article according to claim 8, wherein the non-breathable member is made of pulp or a laminate of pulp and SBR resin. In any one of Claims 8 thru | or 10, the said non-breathable member is a sheet-like thing extended along the surface by the side of the said exhaust hole of the said breathable member,
The non-breathable member has a thickness of 0.05 to 0.2 mm, a tensile strength defined by JIS-Z-0237 of 30 to 90 N / 15 mm, and an elongation defined by JIS-Z-0237. Is 1 to 10%, A method for producing a foamed molded product.   12. The method for producing a foamed molded product according to any one of claims 6 to 11, wherein the foamed molded product is a seat pad. Foam in the cavity at the time of foam molding is provided in the exhaust hole for discharging the gas in the cavity to the outside of the cavity provided in the cavity inner surface of a mold for producing a foam molded body made of foamed synthetic resin. In the exhaust hole closing member for preventing the synthetic resin from entering,
The exhaust hole closing member is:
The exhaust hole can be moved forward and backward so as to be able to take an exhaust hole opening position where the exhaust hole is opened from the exhaust hole to open the exhaust hole, and an exhaust hole closed position where the exhaust hole is closed by retreating into the exhaust hole. An opening and closing member, and
A biasing member that biases the opening / closing member to the exhaust hole opening position;
The urging member is configured such that when a pressing force is applied from the foamed synthetic resin filled in the cavity to the opening / closing member at the exhaust hole opening position during foam molding, the opening / closing member An exhaust hole closing member for a mold, wherein the exhaust hole closing member is configured to allow retreat to a hole closing position.

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