JP5334627B2 - Cushion pad mold and cushion pad manufacturing method using the mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cushion pad molding mold which prevents the breakage of a reinforcement cloth material molded integrally with a foamed resin on the inside of at least a thickness variation part on the back side of the cushion pad when the molded cushion pad is demolded and can easily change the width and height of a recess formed on the inside of the thickness variation part in accordance with a molding situation. <P>SOLUTION: An extension part which is extended from the upper side edge to the back side and makes the cross section of the upper part of the cushion pad be formed in a U shape has a thick part on the side of the upper side edge, a thin part on the side of the tip of the extension part, and the thickness variation part between the thick part and the thin part. The mold which molds the cushion pad with the foamed resin and the reinforcement cloth material covering the foamed resin molded integrally on the inside of at least the thickness variation part has a lower mold, a core mold, and an upper mold and detachably fixes a recess forming cavity insert made of a material which is softer than the material of the core mold to the surface of the core mold in order to form the recess in the inside surface of the thickness variation part. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a molding die for molding a cushion pad made of foamed resin used for, for example, an automobile seat and the like, and a cushion pad manufacturing method using the molding die.

  A seat such as a vehicle represented by an automobile mainly includes a backrest portion and a cushion pad for a seating portion. For example, the cushion pad of the backrest part is formed with an extending part extending from the upper edge to the back side, and the upper part of the cushion pad has a U-shaped cross section. As a manufacturing method for forming a cushion pad having this extended portion, Patent Document 1 discloses a method for manufacturing a seat pad.

  In Patent Document 1, a lower mold is formed from the back surface of the pad body of the cushion pad to the outer surface of the connecting portion of the overhang portion corresponding to the extending portion of the cushion pad, and the outer surface of the flange portion of the overhang portion is formed. A manufacturing method using a three-part mold that includes an upper mold and a core mold that forms the back surface of the pad main body and the inner surface and the front end surface of the flange portion of the overhang portion is disclosed.

  However, in the manufacturing method using the split mold of Patent Document 1, in the flange portion of the overhang portion, the thickness of the tip portion is set to be thinner than the thickness of the other portion. The flow of the foamed resin raw material liquid may deteriorate at the stepped portion, and molding defects may occur. Further, when the step portion of this thickness is formed above (higher position) than the upper mold and the middle mold parting line (bonding surface), the gas escape is bad and as a result, molding failure may occur. .

  Therefore, in Patent Document 1, in order to improve the above-described molding defects, the foamed resin raw material liquid bypass member is used as an insert material in the core-shaped part at the stepped portion where the flow of the foamed resin raw material liquid becomes poor. Has been disclosed to improve the flow of the foamed resin raw material liquid at the time of cushion pad molding and prevent the generation of voids.

  Similarly to Patent Document 2, a cushion pad is formed by using a split mold and using a pre-molded auxiliary foam as an insert material fixed to the core surface with double-sided tape. A manufacturing method is disclosed.

  However, the cushion pad manufactured by the manufacturing method disclosed in Patent Documents 1 and 2 is a part of the cushion pad while the foam resin raw material liquid bypass member or auxiliary foam as an insert material is embedded in the cushion pad. Therefore, an insert material is used for each manufactured cushion pad, and there is a problem that the manufacturing cost of the cushion pad is increased.

  As a technique for solving the problem of using an insert material for each cushion pad to be manufactured, Patent Document 3 discloses a core for a part in which the flow of the foamed resin raw material liquid deteriorates in a split mold. A method for manufacturing a cushion pad using a molding die in which convex portions are formed on the mold is disclosed.

  When a cushion pad is molded using the molding die disclosed in Patent Document 3, since the convex portion provided in the core mold is in an intricate portion inside the extended portion, the molded cushion pad is removed. Undercut shape with respect to the direction, but because the molded cushion pad is made of foamed resin and has elasticity, the molded cushion pad is elastically deformed when the molded cushion pad is removed from the core mold By means of this, it becomes possible to perform die cutting. However, on the inside of the extended portion of the cushion pad, the reinforcing cloth material is molded integrally with the cushion pad main body, so when the molded cushion pad is removed, the reinforcing cloth material is caught on the convex portion provided in the core mold, There was a problem that the reinforcing cloth material was damaged.

  In addition, as described above, the convex portion provided in the core mold is intended to improve the liquid flow of the foamed resin raw material liquid. Therefore, it is desirable that the width and height of the convex portion provided in the core mold that determines the width and height of the flow path can be easily changed. However, since the core mold is a mold, the convex portion provided on the core mold is made of metal and is hard. Accordingly, there is a problem that it is not easy to change the width and height of the convex portion provided in the core mold.

JP 2007-82909 JP 2008-23084 A JP 2008-183129 A

  The present invention has been made in view of the above problems, and an extended portion extending from the upper edge of the foamed cushion pad to the back side so that the upper portion of the cushion pad has a U-shaped cross section is formed at the tip thereof. Since the thickness of the extended portion has a sharp decrease, the thin portion has a thick wall on the upper edge portion side of the extended portion in order to improve molding defects that cause voids in front of the thin portion. When the molded cushion pad is removed, the back side of the cushion pad is formed when the cushion pad having the thickness variation portion having the concave portion on the inside is formed between the portion and the thin portion on the tip side of the extending portion. Prevents damage to the reinforcing cloth material molded integrally with the foamed resin at least inside the wall thickness variation part, and the width and height of the recess provided inside the wall thickness variation part The cushion can be easily changed according to And to provide a method of manufacturing a mold and the cushion pad using the mold of the pad.

  In order to solve the above-described problems, the present inventors have intensively studied a cushion pad mold that can form a thickness variation portion having a concave portion inside. As a result, the recessed portion forming insert made of a material softer than the core shape is detachably fixed to the surface of the core shape corresponding to the recessed portion formed inside the thickness variation portion of the cushion pad to be molded. By doing so, it is found that a cushion pad made of foam resin can be obtained without damaging the reinforcing cloth material formed integrally with the foam resin on the inner surface of at least the thickness variation portion of the back side portion of the cushion pad. It was. The reason why the reinforcing cloth material is not damaged is that the recess forming nest is a softer material than the core mold, so that when the molded cushion pad is removed, the recess forming nest is formed together with the molded cushion pad. This is because the reinforcing cloth material formed integrally with at least the inside of the thickness variation portion of the back surface of the cushion pad does not get caught in the recess forming nest due to the elastic deformation and the decrease in the punching resistance. We also found out.

  In addition, by making the recess forming insert softer than the metal core material, the recess forming insert can be easily processed. It was also found that the width and height of the recess formed inside the portion can be easily changed.

The present invention has been made on the basis of the above-described knowledge, and the gist of the present invention is as follows.
(1) An extending portion that extends from the upper edge portion of the cushion pad made of foamed resin to the back side and has an upper portion of the cushion pad that is U-shaped in cross section includes a thick portion on the upper edge portion side, and the extended portion And a reinforcing cloth that covers the foamed resin and the foamed resin at least inside the thickness-varying part. A mold for molding the cushion pad, which is molded integrally with the material,
A lower mold for forming the shape of the front side of the cushion pad;
A core mold for forming the shape of the back surface side of the cushion pad and the shape of the inside of the extended portion;
An upper mold for forming a shape on the back surface side including the outside of the extended portion of the cushion pad;
Have
In order to form a recess on the inner surface of the thickness variation portion, a recess forming insert made of a material softer than the core type material is detachably fixed to the core type surface. A cushion pad mold.

(2) When the width of the extending portion in the direction orthogonal to the extending direction of the extending portion is L, the width of the recess forming nest is at least 0.8 L, and the recessed portion is formed. The cushion pad mold according to (1) above, wherein a distance a between each end face perpendicular to the width direction of the insert and the outer surface of the extended portion is 15 mm or more.

(3) The cushion pad according to (1) or (2) above, wherein the recess-forming insert is a urethane chip of 147 to 1960 N with 25% hardness according to a hardness test method of JASO-B408 Mold.

(4) The cushion pad mold according to any one of the above (1) to (3), wherein the cushion pad is a back pad for an automobile seat.

(5) An extending portion that extends from the upper edge portion of the cushion pad made of foamed resin to the back side and has an upper portion of the cushion pad having a U-shaped cross section includes a thick portion on the upper edge portion side, and the extended portion And a reinforcing cloth that covers the foamed resin and the foamed resin at least inside the thickness-varying part. A method of manufacturing the cushion pad, wherein the material is integrally molded,
A lower mold for forming the shape of the front side of the cushion pad;
A core mold for forming the shape of the back surface side of the cushion pad and the shape of the inside of the extended portion;
An upper mold for forming a shape on the back surface side including the outside of the extended portion of the cushion pad;
In order to form a concave portion on the inner surface of the thickness variation portion, the concave portion forming insert made of a material softer than the core-type material, which is detachably fixed to the surface of the core type,
When the foamed resin raw material liquid is injected into the cushion pad molding die provided with the above, at least the surface corresponding to the thickness variation portion among the surfaces of the core die to which the recessed portion forming insert is fixed is reinforced. A method for producing a cushion pad, comprising injecting a foamed resin raw material liquid in a state where a cloth material is disposed, and foaming and curing the foamed resin raw material liquid.

(6) When the width of the extending portion in a direction orthogonal to the extending direction of the extending portion is L, the width of the recess forming nest is at least 0.8 L, and the recessed portion is formed. The method for manufacturing a cushion pad according to (5) above, wherein a distance a between each of both end faces perpendicular to the width direction of the insert and the outer surface of the extending portion is 15 mm or more.

(7) The cushion pad according to (5) or (6) above, wherein the recess forming nest is a urethane chip of 147 to 1960 N at 25% hardness according to a hardness test method of JASO-B408 Manufacturing method.

(8) The method for manufacturing a cushion pad according to any one of (5) to (7), wherein the cushion pad is a back pad for an automobile seat.

  According to the cushion pad molding die of the present invention, the recessed cushion forming insert made of a material softer than the core mold material is detachably fixed to the surface of the core mold. A cushion pad made of foamed resin can be obtained without damaging the reinforcing cloth material formed integrally with the foamed resin at least inside the thickness variation portion of the back side portion of the cushion pad at the time of punching. And the shape of the recess inside the thickness variation part provided to prevent molding defects by making the recess forming insert a material that is easier to process because it is softer than the core metal. Can be easily changed to a shape that does not cause molding defects.

  Therefore, according to the mold of the cushion pad of the present invention, with respect to the extending direction of the extending portion, which greatly affects the liquid flow of the foamed resin raw material liquid in the concave portion inside the thickness variation portion of the cushion pad. Cushion pads can be molded by easily changing the width in the perpendicular direction, and the width in the direction perpendicular to the extending direction of the extending portion in the recess forming insert is determined based on the molding results of the various recessed portions. Moreover, it can be set as the predetermined | prescribed range which can obtain the cushion pad without a shaping | molding defect between the upper edge part and front-end | tip part of an extending part.

  In the cushion pad molding die of the present invention, the hardness of the recess forming nest can be within a predetermined range in which the durability of the recess forming nest can be improved.

  Furthermore, the cushion pad molding die of the present invention can be suitably used when molding a back pad for an automobile seat.

  Further, according to the cushion pad manufacturing method of the present invention, a molded cushion is obtained by removably fixing a recess-forming insert made of a material softer than the core-type material to the core-type surface. A cushion pad made of foamed resin can be obtained without damaging the reinforcing cloth material formed integrally with the foamed resin at least inside the thickness variation portion of the back side portion of the cushion pad when the pad is removed. And the shape of the recess inside the thickness variation part provided to prevent molding defects by making the recess forming insert a material that is easier to process because it is softer than the core metal. Can be easily changed to a shape that does not cause molding defects, and a cushion pad without molding defects can be obtained between the upper edge portion and the tip portion of the extending portion.

  According to the cushion pad manufacturing method of the present invention, the concave portion inside the thickness variation portion has a great influence on the flow of the foamed resin raw material liquid, and is perpendicular to the extending direction of the extending portion. Cushion pads can be molded by changing the width easily, and the width in the direction perpendicular to the extending direction of the extending portion in the recessed portion forming insert is extended based on the molding results of the various recessed portions. It is possible to obtain a predetermined range in which a cushion pad free from molding defects can be obtained between the upper edge of the part and the tip part.

  Further, in the cushion pad manufacturing method of the present invention, the hardness of the recess forming nest can be within a predetermined range in which the durability of the recess forming nest can be improved. As a result, the cushion The pad manufacturing cost can be reduced.

  Furthermore, the method for manufacturing a cushion pad according to the present invention can be suitably used when molding a back pad for an automobile seat.

It is a perspective view of the cushion pad shape | molded with the shaping | molding die of one Embodiment of this invention. It is sectional drawing which follows the II line | wire in FIG. It is a schematic diagram of the longitudinal cross-section of the said cushion pad shaping | molding die which is one Embodiment of this invention. It is a schematic diagram of the longitudinal cross-section of the said cushion pad shaping | molding die, Comprising: It is explanatory drawing which expands and shows the periphery of the site | part which fixes the nest | insert for recessed part formation. It is a perspective view which shows the fastener shown in FIG. It is a perspective view which shows the nest | insert for recessed part formation shown in FIG. It is explanatory drawing which shows the condition in the cavity near the thickness fluctuation | variation part in foam molding of the said cushion pad shaping | molding die. It is explanatory drawing which shows the state which the bubble stayed in the level | step-difference part formation part, when a cushion pad is shape | molded without fixing the nest | insert for recessed part formation to the core type | mold of a cushion pad shaping | molding die.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a cushion pad molded with the mold according to one embodiment of the present invention. FIG. 2 is a longitudinal sectional view taken along the line II in FIG. In FIG. 1, reference numeral 500 indicates the cushion pad. The cushion pad 500 is a back pad for a vehicle seat. Reference numeral 505 denotes the front side of the cushion pad, reference numeral 510 denotes the back side of the cushion pad, and reference numeral 515 denotes the upper edge. Reference numeral 520 denotes an extending portion that extends from the upper edge portion 515 to the back side 510 of the cushion pad so that the upper portion of the cushion pad has a U-shaped cross section. Reference numeral 525 denotes the outside of the extended portion, reference numeral 530 denotes the inside of the extended portion, and reference numeral 535 denotes the tip of the extended portion. The extended portion 520 includes a thick portion 540 on the upper edge portion 515 side and a thin portion 545 on the extended portion distal end 535 side, and a thickness variation portion 550 between the thick portion 540 and the thin portion 545. Have The thickness variation portion 550 has a recess 555 in the extended portion inner side 530. Further, the thickness varying portion 550 has a stepped portion 560 on the extended portion outer side 525. The cushion pad 500 has a reinforcing cloth material 570 that is formed integrally with the foamed resin 565 and covers the foamed resin 565 on the back side 510 and the back side of the extended portion inner side 530.

  The thin-walled portion 545 serves as a seating surface to which a resin plate called a backboard that improves the appearance of the back side 510 of the cushion pad is attached. When the recessed portion 555 is not formed in the extended portion 520, the thickness of the extended portion 520 is rapidly reduced at the opposite side of the extended portion distal end 535 of the thin portion 545, that is, at the step portion 560. Due to this sudden decrease in wall thickness, a poor flow of the foamed resin raw material liquid occurs, which causes molding defects such as voids in the stepped portion 560. Therefore, in order to improve such a liquid flow failure of the foamed resin raw material liquid, in this embodiment, a concave portion 555 is formed on the surface of the extending portion inner side 530 between the thick portion 540 and the thin portion 545 to increase the thickness. The fluctuating part 550 is configured to improve the liquid flow failure of the foamed resin raw material liquid and prevent molding defects such as voids in the step part 560.

  Next, a molding die for molding a cushion pad having the thickness varying portion 550 in which the above-described concave portion 555 is formed will be described. FIG. 3 is a schematic diagram of a longitudinal section of the cushion pad mold according to one embodiment of the present invention. In FIG. 3, reference numeral 5 denotes the cushion pad mold. FIG. 3 also shows the reinforcing cloth material 570 disposed in the mold when the foamed resin is foam-molded.

  The cushion pad mold 5 is a split mold, and has an upper mold 10, a core mold 20, a lower mold 30, and a recess forming insert 40. In FIG. 3, the phantom lines indicate a state where the core mold 20 is opened together with the upper mold 10. The lower mold 30 forms the shape of the front side 505 of the cushion pad 500. The core mold 20 forms the shape of the back surface side of the cushion pad 500 and the shape of the extended portion inner side 530. The upper mold 10 forms the shape of the back side 510 including the shape of the extending portion outer side 525 of the cushion pad 500. The recessed portion forming insert 40 forms a recessed portion 555 on the inner surface of the thickness variation portion 550 of the cushion pad 500.

  Reference symbol PL denotes a parting line between the upper mold 10 and the core mold 20.

  The upper mold 10 is provided with a stepped portion forming portion 11, thereby forming a stepped portion 560 in which the sectional thickness of the cushion pad decreases toward the extended portion distal end 535 on the extended portion outer side 525 of the cushion pad 500. Thus, the thickness of the extended portion 520 decreases to the thickness of the thin portion 545.

  The parting line PL is a gas escape inside the cushion pad mold 5 that is required when the foam resin raw material liquid is injected into the cushion pad mold 5 and the foam pad raw material liquid is filled inside the cushion pad mold 5. It functions as a passage. When the stepped portion forming part 11 is provided in front of the parting line PL (upstream side in the direction of foamed resin raw material liquid flow) and at a position higher than the parting line PL, the stepped portion forming part 11 is Thus, in order to inhibit gas escape, the liquid flow of the foamed resin raw material liquid is deteriorated, resulting in defective molding such as generation of voids. Therefore, in the cushion pad mold 5 of this embodiment, the concave portion of the cushion pad 500 on the surface of the core mold 20 is provided so as to improve the gas escape at the step portion forming portion 11 and the liquid flow of the foamed resin raw material liquid. The recess forming insert 40 is detachably fixed to the position where the 555 is formed. The position at which the recessed portion forming insert 40 is detachably fixed faces the stepped portion forming portion 11. By this recess forming insert 40, the outflow of gas and the flow of the foamed resin raw material liquid are improved, and molding defects such as voids can be prevented.

  Here, a method of fixing the recess forming insert 40 to the surface of the core mold 20 will be described. FIG. 4 is a schematic diagram of a longitudinal cross section of the cushion pad mold 5 and is an explanatory view showing an enlargement of the periphery of a portion where the recessed portion forming insert 40 is fixed. The core mold 20 has a fastener 50 at a portion where the recess forming insert 40 is fixed.

  FIG. 5 is a perspective view showing the fastener 50. The fastener 50 has a base 52, a reverse slope 54 and a top 56. For example, the fastener 50 may be press-fitted into the core mold 20 or may be screwed.

  FIG. 6 is a perspective view showing the recess forming insert 40. The recess forming insert 40 has a fitting hole 44. The recess forming insert 40 is fixed to the core mold 20 by fitting a fastener 50 into the insertion hole 44 of the recess forming insert 40. The fastener 50 has a reverse slope portion 54, but when the recess forming insert 40 is inserted, the recess forming insert 40 is elastically deformed and inserted. On the other hand, when the molded cushion pad 500 is removed, the recess forming nest 40 is maintained fixed to the core mold 20 without being detached from the clasp 50 by the reverse gradient 54 of the clasp 50. .

  Further, the surface of the recessed portion 555 of the molded cushion pad 500 is formed so as to have the reinforcing cloth material 570 integrally, but a recessed portion forming portion corresponding to the recessed portion forming insert 40 that forms the recessed portion 555, In the case of being made of metal like the core type described in Patent Document 3, the reinforcing cloth material 570 is formed when the molded cushion pad 500 is removed even if a sufficient escape gradient is given to the recess 555. There is a possibility that the reinforcing cloth material 570 may be damaged by catching on the metal concave portion forming portion (the convex shape as the core shape) of the core die. This is because when the foamed resin raw material liquid injected into the cavity of the mold is foamed and cured when the cushion pad is molded, a pressure of 40 to 100 kPa is applied to the inner surface of the mold, and after the foamed resin raw material liquid is cured This is because the metal recess forming portion (projected shape as the core mold) of the core mold is in a state of being tightened with a cured foamed resin, and the reinforcing cloth material 570 is easily caught. is there.

  On the other hand, the recessed portion forming insert 40 in this embodiment is made of a material softer than the material of the core mold 20, and therefore, when the molded cushion pad 500 is removed, the recessed portion forming insert 40 is slightly formed. Since the outer periphery of the insert 40 is elastically deformed, the foamed resin after curing is released from being tightened to the recess forming insert 40 to reduce the resistance to mold release. Even if the shape of the cushion pad 500 is not given or the reverse gradient shape is given, the molded cushion pad 500 can be removed without damaging the reinforcing cloth material 570. In other words, the cushion pad 500 can be easily removed even if the recess forming nest 40 has a rod shape as shown in FIG. 6, but the recesses that give R to each ridge line of the recess forming nest 40. It goes without saying that the punching resistance can be further reduced by making the cross section perpendicular to the longitudinal direction of the forming insert into a triangle, trapezoid or semicircle.

  When replacing the recessed portion forming insert 40 fixed to the core mold 20, the recessed portion forming insert is applied with a force larger than the force applied to the recessed portion forming insert 40 when the molded cushion pad is removed. By pulling out the core 40, the recess-forming insert 40 fixed to the core mold 20 can be removed. It is preferable that the force required for removing the recess forming insert 40 be of a level that does not require the use of a tool.

  The reinforcing cloth material 570 is mainly used for reinforcing and protecting the cushion pad 500 and suppressing the generation of rubbing sound between the seat frame, and examples of the material include felt, non-woven fabric, and cloth. From the viewpoint of thermoforming, felt or non-woven fabric is preferable, and felt is particularly preferable. The thickness or basis weight of the reinforcing cloth material 570 can be appropriately set according to the specification of the cushion pad. In addition, the reinforcing cloth material 570 is in a range where it is integrally molded with the foam resin, but at the time of foam molding, in order to prevent the recess forming insert 40 and the foam resin from adhering, at least the thickness variation portion 550 On the inner surface, the foamed resin and the reinforcing cloth material 570 need to be formed integrally. The reinforcing cloth material 570 is preferably a flexible material that can be three-dimensionally molded so as to conform to the shape of the back side of the cushion pad and the surface shape of the core mold 20 and the recess forming insert 40. The reinforcing cloth material 570 is preferably preliminarily thermoformed so as to conform to the shape of the back side of the cushion pad and the surface shape of the core mold 20 and the recess forming insert 40.

  The reinforcing cloth material 570 used in the present embodiment is made of felt, and is thermoformed in advance so as to conform to the shape of the back surface side of the cushion pad and the extended portion inner side 530 (including the recessed portion 555). The felt thermoforming method is not particularly limited.

  The material for the recess forming insert 40 is preferably a urethane chip having a 25% hardness (hereinafter referred to as “25% hardness”) in the range of 147 to 1960 N according to the hardness test method of JASO-B408. This is because when the 25% hardness is less than 147N, the recess-forming insert 40 is deformed by the pressure generated during foaming and curing of the foamed resin, and the friction with the molded urethane pad at the time of die-cutting. On the other hand, if the 25% hardness exceeds 1960 N, the amount of elastic deformation at the outer periphery of the recess forming insert 40 becomes extremely small when the cushion pad 500 is removed, and the reinforcing cloth material 570 There is a problem that there is a high possibility that the reinforcing cloth material 570 may be damaged by being caught in the recess forming nest 40. In addition to urethane chips, urethane slab foam having a 25% hardness in the range of 147 to 1960 N can also be used. In the present embodiment, the material for the recess forming insert 400 is a urethane chip having a 25% hardness of 490N.

  Next, the dimensions of the recess forming insert 40 will be described. As shown in FIG. 1, the recess forming nest 40 has a longitudinal direction in a direction orthogonal to the extending direction of the extending portion 520 (a direction orthogonal to the paper surface in FIG. 3). Therefore, the dimension in the longitudinal direction of the recess forming nest 40 is the width of the recess forming nest 40. The recess forming insert 40 is a member fixed to the core mold 20 in order to improve the liquid flow of the foam resin raw material liquid at the time of molding the urethane pad 500. The width of the recess forming nest is particularly important. When the width of the extending part 520 of the cushion pad 500 to be molded is L in the direction perpendicular to the extending direction of the extending part, the width of the recess forming insert 40 is at least 0.8 L. In addition, it is preferable that a distance a between each end surface perpendicular to the width direction of the recess forming insert 40 and the outer surface of the extension portion 520 of the cushion pad to be molded is 15 mm or more. This is because when the width of the recessed portion forming insert 40 is less than 0.8 L, the recessed portion forming insert having a liquid flow bypass function described later with respect to the liquid flow of the foamed resin raw material liquid 70 when the cushion pad 500 is molded. When the distance a is less than 15 mm, the range occupied by 40 in the mold is reduced, and if the distance a is less than 15 mm, both ends of the recess 555 and the outer surface of the extended portion 520 are formed in the cushion pad 500 after molding. Since the thickness of the foamed resin wall between the extension portion 520 and the extension portion 520 becomes thin, the rigidity in the longitudinal direction of the extension portion 530 of the extension portion inner side 530 decreases. Further, it is preferable that the central axis orthogonal to the longitudinal direction of the recess forming nest 40 is the same as the central axis orthogonal to the extending direction of the extending portion 520 of the cushion pad 500. In the present embodiment, the width of the recess forming insert 40 is 0.8L.

  Further, with respect to the fixing interval of the recess forming nest 40, the center and both ends in the width direction of the recess forming nest 40 as shown in the fitting holes 44 of the present embodiment indicated by reference numerals 44a, 44b and 44c in FIG. Although it is preferable to fix at least 3 places, it is not restricted to this.

  Next, a method for manufacturing the cushion pad 500 using the cushion pad mold 5 will be described.

  First, after inserting the fastener 50 into the insertion hole 44 of the recess forming insert 40 and fixing the recess forming insert 40 to the surface of the core mold 20, the reinforcing cloth material 570 is inserted into the recess forming insert 40. The core 40 is fixed at a predetermined position of the core mold 20. As a result, as shown in FIG. 4, the recessed portion forming insert 40 is disposed between the core mold 20 and the reinforcing cloth material 570 in the portion where the recessed portion forming insert 40 is fixed. It becomes.

  Next, in a state where the core mold 20 is opened together with the upper mold 10 as indicated by phantom lines in FIG. 3, for example, a predetermined amount of a foamed resin raw material liquid of flexible polyurethane foam is injected into the lower mold 30. .

  Then, the upper mold 10 and the core mold 20 are closed onto the lower mold 30 to form a cavity therein, and foam molding is performed by heating at a predetermined temperature for a predetermined time. FIG. 7 is an explanatory diagram showing a situation in the cavity near the thickness variation portion 550 during foam molding.

  The foamed resin raw material liquid 70 in the lower mold 30 flows between the upper mold 10 and the core mold 20. That is, the foamed resin raw material liquid 70 in the lower mold 30 is formed from the molding surface 72 of the upper mold 10 and the molding surface 74 formed from the thick part 540 to the thin part 545 via the reinforcing cloth material 570 in the core mold 20. The foamed resin raw material liquid 70 collides with the recess forming nest 40, although it flows between the forming surface 76 that forms the extended portion tip 535. Since the recess forming nest 40 has a function as a baffle plate, the foamed resin raw material liquid 70 is detoured upward as indicated by an arrow A in FIG.

  Since the bypassed foamed resin raw material liquid 70 flows on the recess forming insert 40 along the molding surface 72 of the upper mold 10, the air mixed in the foamed resin raw material liquid 70 becomes bubbles in the step portion forming part 11. It reaches the tip of the molding surface 76 of the core mold 20 together with the foamed resin raw material liquid 70 without staying.

  Further, the air that has passed through the portion corresponding to the thickness variation portion 550 of the cushion pad 500 is shown in FIG. 7 from the parting line PL of the upper mold 10 and the core mold 20 that is located downstream of the thickness variation portion 550. It is pulled out as shown by arrow B. Since this parting line PL is located at the corner of the thin part 545 downstream of the thickness variation part 550, air is exhausted without remaining between the upper mold 10 and the core mold 20, and the upper part The foamed resin raw material liquid 70 can be filled evenly between the mold 10 and the core mold 20. FIG. 8 shows a state where bubbles 90 stay in the stepped portion forming portion 11 of the cushion pad when the cushion pad is molded without fixing the recess forming insert 40 to the core mold 20.

  After the cushion pad 500 is molded in this way, the mold is cooled as needed, and the upper mold 10 is rotated upward to open the mold and hold the molded cushion pad 500. 20 is separated from the upper mold 10, and then the cushion pad molded from the core mold 20 is removed. Here, the foamed resin that has undergone the foam molding is molded integrally with the reinforcing member 570 to be a cushion pad 500, but the recess forming insert 40 is fixed to the surface of the core mold 20. Become. Accordingly, when the cushion pad 500 is subsequently formed, only the reinforcing cloth material 570 may be disposed in the core mold to which the recess forming insert 40 is fixed. Before changing the shape of the concave portion 555 provided inside the thickness variation portion 550 of the cushion pad 500, or when replacing the concave portion forming insert 40 due to wear or the like, the reinforcing cloth material 570 is not disposed. Next, after removing the recess forming insert 40 fixed to the core mold 20 and fixing another recess forming insert 40 to the core mold 20 again, the reinforcing cloth material 570 is inserted into the recess forming insert. Of course, it can be arranged at a predetermined position of the core mold 20 to which 40 is fixed.

  The invention is further illustrated in the following examples.

  A cushion pad 500 sample was molded using the cushion pad mold 5 shown in FIG. 3 of the above embodiment. In addition, the width L (refer FIG. 1) of the extension part 520 of the cushion pad 500 in the direction orthogonal to the extension direction of the extension part 520 was 180 mm.

(Sample No. 1-9)
A recess-forming insert 40 was produced using a urethane chip and incorporated into a cushion pad mold 5, and each of Sample No. 1 to No. 9 was formed as Examples 1 to 9. In addition, as shown in Table 1, the width of the recess-forming insert 40 and the 25% hardness of the urethane chip in Sample Nos. 1 to 9 were changed.

(Sample No. 10)
As Example 10, one Sample No. 10 was molded under the same conditions as Sample No. 2 except that the recess forming insert 40 was prepared using a urethane foam slab of 25% hardness and 490 N.

(Sample No.11)
As Comparative Example 1, one sample No. 11 was molded under the same conditions as Sample No. 2, except that the recess forming insert 40 was made using die steel.

  In addition, the cushion pad rigidity, the void generation situation, the amount of nest deformation for forming the recess, and the damage situation of the reinforcing cloth material were evaluated as follows.

(Cushion pad rigidity)
About each of sample No. 1-11, the extension part 520 was evaluated as follows in the state of the extension part 520 when it turned back to the cushion pad back side 510 with the load 8N.
◎: The folding angle of the extended portion 520 in the recess 555 is 90 ° or more and less than 115 ° ○: The folding angle of the extending portion 520 in the recess 555 is 115 ° or more and less than 135 ° ×: The folding angle of the extending portion 520 in the recess 555 Is 135 ° or more and less than 180 °

(Void occurrence status)
About each of sample No. 1-11, the generation | occurrence | production state of the void in the level | step-difference part 560 was investigated, and it evaluated as follows according to the generation | occurrence | production degree of a void.
◎: No void generation ○: Minor void generation (good product by reworking)
×: Severe voids are generated (the product does not become non-defective even if it is reworked)

(Indentation deformation for recess formation)
When each surface of the recessed portion 555 of the molded cushion pad 500 is deformed by 3 mm or more compared to the normal shape, it is determined that the recessed portion forming insert 40 is deformed and needs to be replaced. For each of Sample Nos. 1 to 11, the amount of deformation of the recess 555 with respect to the regular shape was investigated and evaluated as follows.
◎: Deformation amount less than 1 mm ○: Deformation amount 1 mm or more and less than 3 mm ×: Deformation amount 3 mm or more

(Reinforcing fabric damage situation)
For each of Sample Nos. 1 to 11, the state of breakage of the reinforcing cloth material 570 in the concave portion 555 (breakage during die cutting) was investigated and evaluated as follows.
◎: No damage ○: Minor damage (good product by reworking)
×: Severe breakage (does not become a good product by reworking)

  The evaluation results are also shown in Table 1. As is clear from the table, in Comparative Example 1 in which the recess forming insert 40 was made of die steel (metal), the reinforcing cloth material 570 was damaged to the extent that it would not become a good product even when it was reworked. When the recess-forming insert 40 is made with a urethane tip or urethane slab foam that is softer than die steel (metal), the reinforcing cloth material 570 is not damaged at the time of mold removal, It turns out that it was only a minor breakage. In particular, it can be seen that when the 25% hardness of the recess forming insert 40 is 1960 N or less, the reinforcing cloth material 570 can be prevented from being damaged.

  Further, even if the recess-forming insert 40 is made of a soft material such as a urethane chip, the recess-forming insert 40 is not deformed when the cushion pad 500 is foamed or removed, and Examples 6 to 10 are As shown, when the 25% hardness of the recess forming nest 40 is 147 N or more, the deformation amount of the recess forming nest 40 is particularly small.

  The influence of the width of the recess forming insert 40 on the occurrence of voids and the rigidity of the extended portion 520 of the cushion pad 500 is large. As shown in the second and third embodiments, the width of the recess forming insert 40 is large. When the distance a between each end surface perpendicular to the width direction of the recess forming insert 40 and the outer surface of the extending portion 520 is 15 mm or more, the void pad is prevented and the cushion pad 500 is It can be seen that the securing of the rigidity of the extending portion 520 can be achieved particularly well.

  In addition, the place mentioned above only showed an example of embodiment of this invention, and this invention can add a various change within the description range of a claim. For example, in this embodiment, the reinforcing cloth material 570 is formed integrally with the foamed resin on almost the entire back surface side of the cushion pad and the extended portion inner side 530, but only inside the wall thickness variable portion extended portion 550. Alternatively, the reinforcing cloth material 540 and the foamed resin may be integrally formed.

  In addition, even if the wall thickness varying portion 525 has a shape in which the extended portion outer side 525 projects further outward, the effect of the present invention can be similarly obtained.

  And as a raw material of a cushion pad, the foamed resin which has the elasticity etc. which exhibit the function as a cushion pad other than the flexible polyurethane foam illustrated by this embodiment can also be used.

  Further, the foam resin material liquid is injected into the cavity by providing an inlet in the upper mold 10 or the lower mold 30 and closing the upper mold 10 and the core mold 20 on the lower mold 30 and then through the inlet. You can go.

  According to the cushion pad molding die of the present invention, the recessed cushion forming insert made of a material softer than the core mold material is detachably fixed to the surface of the core mold. A cushion pad made of foamed resin can be obtained without damaging the reinforcing cloth material formed integrally with the foamed resin at least inside the thickness variation portion of the back side portion of the cushion pad at the time of punching. And the shape of the recess inside the thickness variation part provided to prevent molding defects by making the recess forming insert a material that is easier to process because it is softer than the core metal. Can be easily changed to a shape that does not cause molding defects.

  Further, according to the cushion pad manufacturing method of the present invention, a molded cushion is obtained by removably fixing a recess-forming insert made of a material softer than the core-type material to the core-type surface. A cushion pad made of foamed resin can be obtained without damaging the reinforcing cloth material formed integrally with the foamed resin at least inside the thickness variation portion of the back side portion of the cushion pad when the pad is removed. And the shape of the recess inside the thickness variation part provided to prevent molding defects by making the recess forming insert a material that is easier to process because it is softer than the core metal. Can be easily changed to a shape that does not cause molding defects, and a cushion pad without molding defects can be obtained between the upper edge portion and the tip portion of the extending portion.

5 Cushion pad mold
10 Upper mold
20 Core type
11 Step forming part
30 Lower mold
40 Nest for recess formation
44, 44a, 44b, 44c Insertion hole
50 Fastener
52 Base
54 Reverse slope
56 Top
70 Foam resin raw material liquid
72 Upper mold surface
74 Forming surface from thick part to thin part through reinforcing cloth material in core type
76 Molding surface that forms the tip of the extension
90 bubbles
PL parting line
500 cushion pads
505 Front side of cushion pad
510 Back side of cushion pad
515 Upper edge
520 Extension
525 Outside extension
530 Inside extension
535 Extension end
540 Thick part
545 Thin section
550 Thickness variation part
555 recess
560 Stepped part
565 Foam resin
570 Reinforcement cloth material

Claims (8)

An extended portion that extends from the upper edge of the foam pad cushion pad to the back side and has a U-shaped cross section at the upper portion of the cushion pad, and a thick wall portion on the upper edge side, and the distal end side of the extended portion And a reinforcing cloth material that covers the foamed resin and the foamed resin inside at least the inside of the thickness-variable part, and has a thickness-variable part between the thick-walled part and the thin-walled part. A mold for molding the cushion pad that is integrally molded,
A lower mold for forming the shape of the front side of the cushion pad;
A core mold for forming the shape of the back surface side of the cushion pad and the shape of the inside of the extended portion;
An upper mold for forming a shape on the back surface side including the outside of the extended portion of the cushion pad;
Have
In order to form a recess on the inner surface of the thickness variation portion, a recess forming insert made of a material softer than the core type material is detachably fixed to the core type surface. A cushion pad mold.   When the width of the extending portion in the direction orthogonal to the extending direction of the extending portion is L, the width of the recessed portion forming insert is at least 0.8 L, and the recessed portion forming insert 2. The mold for forming a cushion pad according to claim 1, wherein a distance a between each of both end faces perpendicular to the width direction and the outer surface of the extending portion is 15 mm or more.   The cushion pad mold according to claim 1 or 2, wherein the recess forming nest is a urethane chip having a hardness of 147 to 1960 N at 25% hardness according to a hardness test method of JASO-B408.   The said cushion pad is a back pad for seats of a motor vehicle, The shaping | molding die of the cushion pad of any one of Claims 1-3 characterized by the above-mentioned. An extended portion that extends from the upper edge of the foam pad cushion pad to the back side and has a U-shaped cross section at the upper portion of the cushion pad, and a thick wall portion on the upper edge side, and the distal end side of the extended portion And a reinforcing cloth material that covers the foamed resin and the foamed resin inside at least the inside of the thickness-variable part, and has a thickness-variable part between the thick-walled part and the thin-walled part. A method of manufacturing the cushion pad formed integrally,
A lower mold for forming the shape of the front side of the cushion pad;
A core mold for forming the shape of the back surface side of the cushion pad and the shape of the inside of the extended portion;
An upper mold for forming a shape on the back surface side including the outside of the extended portion of the cushion pad;
In order to form a concave portion on the inner surface of the thickness variation portion, the concave portion forming insert made of a material softer than the core-type material, which is detachably fixed to the surface of the core type,
When the foamed resin raw material liquid is injected into the cushion pad molding die provided with the above, at least the surface corresponding to the thickness variation portion among the surfaces of the core die to which the recessed portion forming insert is fixed is reinforced. A method for producing a cushion pad, comprising injecting a foamed resin raw material liquid in a state where a cloth material is disposed, and foaming and curing the foamed resin raw material liquid.   When the width of the extending portion in the direction orthogonal to the extending direction of the extending portion is L, the width of the recessed portion forming insert is at least 0.8 L, and the recessed portion forming insert 6. The method of manufacturing a cushion pad according to claim 5, wherein a distance a between each of both end faces perpendicular to the width direction of the first and the outer surfaces of the extending portion is 15 mm or more.   The method for manufacturing a cushion pad according to claim 5 or 6, wherein the recess-forming insert is a urethane chip having a hardness of 147 to 1960 N at 25% hardness according to a hardness test method of JASO-B408.   The said cushion pad is a back pad for seats of a motor vehicle, The manufacturing method of the cushion pad of any one of Claims 5-7 characterized by the above-mentioned.

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