JP4541778B2 - Manufacturing method of seat pad - Google Patents

Description

  The present invention relates to a method for manufacturing a seat pad used as a seat cushion material for a vehicle or the like.

  In general, a seat pad used as a seat cushion material of an automobile or the like is made of a flexible foam molded product such as a flexible polyurethane foam. Such a seat pad is configured as a seat by being assembled to the seat frame, but there is a problem that abnormal noise is generated or damaged due to vibration with the seat frame or friction with the seat frame during seating. Therefore, in order to prevent the occurrence of such abnormal noise, to protect against damage and to strengthen, the back side of the pad body made of soft foam is integrated with the back cloth such as non-woven fabric as a backing material by foam molding of the soft foam. (For example, refer to Patent Documents 1 and 2 below).

  By the way, in recent automobiles, there is a case where a side airbag device that inflates an airbag and restrains an occupant from the side at the time of a vehicle collision is mounted, and such a side airbag device has, for example, a seat backrest portion. It is embedded in the door side of the back pad that constitutes it. In this case, the pad main body covering the airbag device is provided with a linear tearing portion for allowing the airbag to be inserted when the airbag device is operated, and the back cloth also corresponds to the linear tearing portion. The slit part is provided so that it may do (refer the following patent document 3).

  FIG. 8 is a view showing a part of the back pad 100 configured so that the side airbag device can be mounted. As shown in the figure, an accommodation recess 104 for accommodating the side airbag device 120 is provided on the back side of the side portion 102, and an airbag (not shown) is inserted into the accommodation recess 104. A linear cleavage portion 106 extending in the vertical direction is provided. Further, a back surface cloth 112 such as a nonwoven fabric is laminated and integrated on the back surface of the pad body 110 by foam molding of polyurethane foam, and the back surface cloth 112 has a slit as a notch so as to correspond to the cleavage portion 106. A portion 114 is provided.

When the back pad 100 is molded, when the back cloth 112 is attached to the mold 120, as shown in FIGS. 9 (a) and (b), The protrusion 122 of the forming die 120 for forming the cleavage part 106 is inserted. The back pad can be obtained by injecting a foam foam stock solution into the cavity of the mold and filling it with foam while the back cloth is mounted on the mold in this manner.
JP-A-6-171002 JP 2000-71838 A Japanese Patent Laid-Open No. 9-254735

  In the above-described molding method, the protrusion 122 of the molding die 120 is inserted and attached to the slit portion 114 of the back surface cloth 112. However, since the back surface cloth 112 has a dimensional tolerance, As shown in FIGS. 8 and 9 (b), the opening edge 116 of the slit 114 spreads, and therefore polyurethane may enter between the mold 120 and the back cloth 112, resulting in molding defects. When such a molding defect occurs, the pad thickness is reduced in the side portion 102 provided with the housing recess 104, and therefore the hardness of the pad surface is felt by the back cloth 112 cured by impregnation with polyurethane foam, The surface feel and sitting comfort will be impaired.

  The present invention has been made in view of the above points, and in the sheet pad configured to embed the airbag device, the sheet pad capable of eliminating the molding defect caused by the back cloth. An object is to provide a manufacturing method.

  A manufacturing method of a pad for a sheet according to the present invention comprises a pad body made of a flexible foam, and a back cloth laminated and integrated on the back surface of the pad body by foam molding of the flexible foam. In the method for manufacturing a seat pad provided with a housing recess for housing the airbag device and a linear tearing portion through which the airbag is inserted when the airbag device is operated, the pad body is provided on the back cloth. A slit portion corresponding to the cleavage portion is provided by being connected at one or a plurality of locations in the longitudinal direction, and the slit portion is matched with a protrusion for forming the cleavage portion provided in the mold. The back body cloth is attached to the mold surface of the molding die, and the pad main body is molded by foaming a foaming stock solution in the cavity of the molding die attached with the back cloth. It is.

  In the manufacturing method of the present invention, the slit portion of the back cloth for inserting the airbag is not simply a slit shape corresponding to the cleavage portion of the pad body, but is connected at one or a plurality of locations in the longitudinal direction. In this way, when mounted on the mold surface according to the ridge of the molding die, the opening edge of the slit portion is not widened by the connecting portion, and the opening edge is held along the side surface of the ridge. be able to. Therefore, intrusion of the flexible foam between the back cloth and the mold at the slit portion can be prevented, and molding defects can be eliminated.

  In the manufacturing method of the present invention, the slit portion is formed of an elongated rectangular opening and is connected at one or a plurality of locations in the longitudinal direction, and a cut extending from the long side of the slit portion is formed at the base portion of the connection portion. It may be provided. By providing a cut at the base of the connecting portion that connects a part of the slit portion in this way, the cut can be triggered when the airbag is deployed, and the connecting portion can be easily broken. Can be improved.

  As described above, according to the present invention, there is no inconvenience that the opening edge of the slit portion of the back cloth for allowing the airbag to pass through widens during foam molding to form a gap with the mold. Therefore, it is possible to eliminate molding defects caused by the back surface cloth in the vicinity of the slit portion, and thus a sheet pad having excellent surface tactile sensation and sitting comfort in the embedded portion of the airbag apparatus can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a pad 10 for a sheet according to an embodiment of the present invention, FIG. 2 is a sectional view of the pad 10 in the vertical direction, and FIG. 3 is a sectional view in the width direction. As shown in the figure, this seat pad 10 is a back pad used for a backrest portion of a front seat of an automobile, for example, and is laminated and integrated on the back surface of a pad body 12 made of a highly elastic flexible polyurethane foam. It consists of a back fabric 14 and is assembled to the seat frame.

  As shown in FIG. 1, the pad main body 12 includes a main portion 16 at the center in the width direction that receives the back of the occupant, and a pair of left and right side portions 18 a and 18 b formed in a protruding shape on both sides in the width direction. In addition, as shown in FIGS. 2 and 3, an inward flange-like overhanging portion 20 for frame mounting is integrally formed on the back side of the pad main body 12 on the three sides of the upper side and the left and right sides. As a result, the pad main body 12 has a generally bag shape as a whole. A mounting hole 22 for mounting a headrest (not shown) is provided on the upper surface of the pad main body 12.

  Moreover, in the side part 18a by the side of the door, the accommodation recessed part 24 for accommodating the side airbag apparatus 1 is provided in the back surface side. As shown in FIG. 3, the accommodating recess 24 can accommodate the box-shaped side airbag device 1 in a concave groove portion 26 extending in the vertical direction formed between the protruding portion 20 on the back surface side of the side portion 18 a. In addition, it is formed by sinking into a square toward the pad surface side.

  Further, in the bottom wall portion (front side wall portion) of the housing recess 24, a linear tearing portion 28 through which an airbag (not shown) is inserted when the side airbag device 1 is operated is provided at the corner portion on the outer side in the width direction. It has been. The cleaving portion 28 is formed to extend in the vertical direction over substantially the entire vertical dimension of the housing recess 24 (see FIG. 1). In this embodiment, the cleaving portion 28 is formed as a fragile portion by providing a concave groove extending in the vertical direction on the wall surface of the housing concave portion 24, and the airbag is inserted by being cleaved by the deployment pressure of the airbag. It is like that. In place of such a non-penetrating groove-shaped cleavage portion 28, a slit-shaped cleavage portion penetrating to the pad surface may be provided.

  The back surface cloth 14 is integrated by foam molding of polyurethane foam so as to cover substantially the entire back surface of the main portion 16 and the side portions 18a and 18b including the inner side surface of the housing recess 24, and the inside of the overhang portion 20 is The side surfaces are also covered with the back surface cloth 14. Here, the back surface cloth 14 plays a role of protecting the pad main body 12 and suppressing generation of a rubbing sound with the seat frame (not shown), and can play such a role. Any non-woven fabric, woven or knitted fabric, or a laminated composite of these can be used without particular limitation. Generally, a coarse blanket, a cold chill, a felt, or the like is used.

  The shape of the base fabric that constitutes the back cloth 14 is as shown in FIG. 4, and the opposing edges on the left and right sides (specifically, edges A1 and A2, edges B1 and B2, edges C1 and C2, edges D1 and D2, edges E1 and E2, edges F1 and F2, edges G1 and G2, edges H1 and H2) are stitched to form a bag shape that conforms to the back surface shape of the pad body 12. Is done. Accordingly, the concave portion backing portion 30 that is lined on the inner surface of the accommodating concave portion 24 is also sewn in a three-dimensional shape.

  The recessed portion backing portion 30 is provided with a slit portion 32 extending in the vertical direction so as to correspond to the cleavage portion 28 of the pad main body 12. The slit portion 32 is formed of an elongated rectangular opening having a constant width, and is connected in a bridging manner at one place in the central portion in the longitudinal direction. That is, the slit portion 32 is connected at the central portion in the longitudinal direction by a connecting portion 34 that traverses the elongated rectangular opening, thereby two slits (openings) above and below the connecting portion 34. Are provided in a separated state. Note that the connecting portion 34 is not limited to one location in the longitudinal direction, and may be provided at two or more locations. In the present invention, providing one location or two locations may cause molding defects while ensuring the deployability of the airbag. It is suitable for eliminating. Moreover, when providing the connection part 34 in multiple places, arrange | positioning at equal intervals is preferable.

  As shown in the enlarged view of the X portion in FIG. 4, the connecting portion 34 is provided with a cut 36 extending continuously from the long side of the slit portion 32 at the base portion thereof. A part in the width direction at the base is cut. In this embodiment, the cuts 36 are provided at all four locations on both sides of each base portion of the connecting portion 34, but may be provided at any one of these locations.

  The back cloth 14 is provided with a mounting hole 38 for a headrest at a position corresponding to the mounting hole 22 of the pad main body 12. Further, a through hole 40 is provided for mounting the back cloth 14 to a molding die described later.

  When manufacturing the sheet pad 10, first, a base fabric constituting the back fabric 14 is formed into a shape shown in FIG. 4 by punching or the like, and then the predetermined sewing described above is performed on the base fabric. By carrying out, the bag-like back surface cloth 14 is produced.

  Next, the produced back cloth 14 is mounted in the mold 50 and the pad main body 12 is foam-molded.

  Here, as shown in FIGS. 5 and 7, the mold 50 has a lower mold 52 that is recessed so as to mold the surface side portion of the pad main body 12, and an upper surface opening of the lower mold 52 to open and close the foaming space. And an upper die 56 for forming the cavity 54, and the upper die 56 is provided with a core die 58 for forming the protruding portion 20. As shown in FIGS. 6 and 7, the core mold 58 is provided with a convex portion 60 for forming the accommodating concave portion 24, and the cleavage portion 28 is provided at the front corner of the convex portion 60. A protrusion 62 for forming is provided. The protrusion 62 has a flat plate shape with a substantially constant thickness and extending in the vertical direction, and protrusions 64 and 64 are set at the upper and lower ends of the protrusion 62.

  In foam molding, first, as shown in FIG. 5, the back cloth 14 is put on the core mold 58, and a headrest pin 66 provided in the core mold 58 is inserted into the mounting hole 38. The back cloth 14 is attached to the mold surface of the mold 50 by inserting the fastener 68 of the core mold 58 into the through hole 40.

  At that time, as shown in FIG. 6, the back surface cloth 14 is mounted so that the slit portion 32 is aligned with the protrusion 62 of the core mold 58. Preferably, both ends of the slit portion 32 are hooked on the protrusions 64 at both ends of the ridge 62 so that the slit portion 32 is attached to the ridge 62 in a state where tension is applied in the longitudinal direction. More specifically, the length b of the slit portion 32 is slightly shorter (for example, about 3 mm) than the length a of the ridge 62, and when the slit portion 32 is attached to the ridge 62, the back cloth 14, when the protrusions 62 are fitted into the slit portion 32 while pulling as shown by arrows α on both sides in the longitudinal direction of the slit portion 32, the slit portion 32 is tensioned in the longitudinal direction. Mounted in a state. In addition, by providing the protrusions 64 at both ends of the protrusion 62 as described above, it is easy to hook both ends of the slit portion 32 on the protrusion 62, and workability is improved.

  Next, after injecting a polyurethane foam foaming stock solution U into the cavity 54 using an injector (not shown), the upper mold 56 is closed to seal the cavity 54. Thus, the foaming stock solution U is foam-filled in the cavity 54, the pad main body 12 made of polyurethane foam is foam-molded, and the back cloth 14 is integrated on the back surface thereof.

  At that time, as described above, since the slit portion 32 of the back surface cloth 14 is connected in a bridging manner by the connecting portion 34, the opening edge 33 of the slit portion 32 does not widen, and the opening edge 33 is formed of the core 58. It can be held in a state along the side surface of the protrusion 62. In particular, in the present embodiment, since the slit portion 32 is attached to the protrusion 62 with tension in the longitudinal direction, a gap between the opening edge 33 of the slit portion 32 and the mold 50 is formed. It can be eliminated more reliably. As described above, at the time of foam molding, the opening edge 33 of the slit portion 32 is not fluctuated by the polyurethane foam that is filled with foam, and therefore, molding defects caused by the back cloth 14 in the vicinity of the slit portion 32 can be eliminated.

  In this way, after molding, the upper mold 56 is opened, and the core mold 58 is further detached from the upper mold 56, and the mold is opened and then removed, so that molding failure in the embedded portion of the side airbag device 1 can be prevented. No sheet pad 10 is obtained.

  Further, in the obtained sheet pad 10, the slit portion 32 corresponding to the linear cleavage portion 28 of the pad main body 12 is partially connected in the longitudinal direction by the connecting portion 34. Since the cut portion 36 is provided at the base portion, when the airbag is deployed, the cut portion 36 becomes a trigger, and the connecting portion 34 is easily broken, so that the deployability of the airbag can be improved.

  In the above-described embodiment, the seat back pad used for the backrest portion of the automobile seat has been described. However, if the airbag device is a seat pad embedded therein, the seat cushion pad or the like constituting the seat surface portion that receives the buttocks is used. It is also possible to apply to the pads of various vehicle seats other than those for automobiles.

The perspective view of the pad for sheets concerning one embodiment of the present invention. The longitudinal cross-sectional view in the up-down direction of this pad for sheets. The longitudinal cross-sectional view in the width direction of this pad for sheets. The developed view of the back surface fabric used for this pad for sheets. The perspective view at the time of the back surface cloth mounting | wearing of the shaping | molding die used for shaping | molding of this pad for sheets. The principal part expansion perspective view before (a) of attachment of the back surface cloth with respect to a shaping | molding die, and after attachment (b). Sectional drawing of the shaping | molding die at the time of shaping | molding of the said pad for sheets. The partial expanded sectional view of the conventional pad for sheets. The principal part expansion perspective view before (a) of mounting | wearing with the back surface cloth with respect to the shaping | molding die in the example shown in FIG. 8, and (b) after mounting | wearing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 …… Side airbag apparatus 10 …… Seat pad 12 …… Pad body 14 …… Back cloth 24 …… Receiving recess 28 …… Cleavage part 32 …… Slit part 34 …… Connecting part 36 …… Slot 50 …… Mold 54 ... Cavity 62 ... Projection

Claims (2)

A pad main body made of a flexible foam; and a back surface cloth laminated and integrated on the back surface of the pad main body by foam molding of the soft foam; an accommodation recess for accommodating an airbag device in the pad main body; In the manufacturing method of the seat pad provided with a linear tearing portion through which the airbag is inserted when the airbag device is activated,
A slit portion corresponding to the cleavage portion of the pad main body is connected to the back surface cloth at one or a plurality of locations in the longitudinal direction,
Attaching the back cloth to the mold surface of the molding die so as to match the slit portion with the ridge for molding the cleavage portion provided in the molding die,
A method for producing a pad for a sheet, wherein the pad main body is molded by foaming a foaming stock solution in a cavity of the molding die equipped with the back cloth. The slit portion is formed of an elongated rectangular opening, and is connected at one or a plurality of locations in the longitudinal direction, and a cut extending from the long side of the slit portion is provided at the base portion of the connection portion. The manufacturing method of the pad for sheets of Claim 1 to do.

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