JP6936648B2 - Vehicle seat pads and their manufacturing methods - Google Patents

Description

The present invention relates to a vehicle seat pad constituting a vehicle seat and a method for manufacturing the same.

The seat pads that make up the seats and backrests of vehicle seats such as automobiles have conventionally been made of flexible polyurethane foam moldings so as to provide comfortable cushioning. However, in recent years, in order to improve fuel efficiency, there is a movement to respond to the weight reduction of vehicles by having a beaded foam molded product such as a policerol foam partially carry it (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 9-70330

However, since the bead foam molded products such as Patent Document 1 shrink during molding and the dimensional accuracy cannot be improved, it is difficult to set them in the foam molding mold, and it is difficult to integrally mold the polyurethane foam molded products. be.
Therefore, in order to reduce the weight, the present inventor has newly considered using a blow molded product instead of the bead foam molded product, but it is difficult as it is. Even if the parison is made of polypropylene resin, which is a thermoplastic resin, and the blow molded product made from this parison is set in a foam molding mold to integrally mold a flexible polyurethane foam molded product, the bond between the two is poor and integrated. It is becoming difficult to convert.

The present invention solves the above problems, and provides a vehicle seat pad and a method for manufacturing the same, which improves the bondability with a flexible polyurethane foam molded product while partially using a blow molded product and realizes weight reduction. The purpose is.

In order to achieve the above object, the gist of the first invention is a vehicle seat pad in which at least the contact surface portion on the side where the occupant comes into contact is formed of a flexible polyurethane foam molded body, and is formed in a hollow molded body of thermoplastic plastic. The core pad of the blow-molded product and the flexible polyurethane foam molded body are formed, the contact surface portion is formed on the design surface side thereof, and the inner surface is formed so as to follow the upper surface shape of the core pad. A surface pad that covers the upper surface of the core pad, and a non-woven fabric that is interposed between the surface pad and the core pad. The vehicle seat pad is provided with a bonding material in which the upper surface side of the core pad is inserted into the core pad to be integrated with the core pad. The vehicle seat pad of the second invention is the first invention , wherein the non-woven fabric has a base layer of a spunbonded non-woven fabric layer and an outer layer of a non-woven fabric layer in which at least the core pad side of the base layer is mechanically entangled with raised parts. It is characterized in that it is bonded and laminated, and the basis weight of the base layer is larger than that of the outer layer. The vehicle seat pad of the third invention is the first or second invention, in which the core pad is based on a polypropylene resin, while the non-woven fabric has a base layer of PET fibers and at least an outer layer of polypropylene fibers on the core pad side. It is characterized in that it is laminated by combining. The vehicle seat pad of the fourth invention, in the first to third invention, has an exposed surface to the lower surface of the hollow body according to the core pads, while forming the exposed surface gentle uniform, partially It is characterized in that a recess is formed on the upper surface side. The vehicle seat pad of the fifth invention is the first to fourth inventions, in which an undercut portion is formed on a side wall near the lower surface of the core pad, and the surface layer pad forms a portion of the undercut portion from the upper surface side of the core pad. It is characterized in that it covers and reaches the lower surface of the core pad. The vehicle seat pad of the sixth invention is a blow-molded product in which a collar portion in which a core pad projects outward from a side wall of a hollow body is integrally formed according to the first to fifth inventions, and the collar portion is the surface layer. It is characterized by being embedded in a pad. The vehicle seat pad of the seventh invention is characterized in that the core pad of the sixth invention is provided with a mounting portion for fixing a connection to a vehicle body so that a part of the collar portion protrudes to the outside of the surface layer pad. do.
The gist of the eighth invention is a method for manufacturing a vehicle seat pad in which at least the contact surface portion on the side where the occupant comes into contact is formed of a flexible polyurethane foam molded body, which is a blow molding mold for molding the core pad. One side of the sheet-shaped bonding material made of non-woven fabric is directed to one of the split mold surfaces for molding the upper surface side of the The upper surface side of the core pad formed in the hollow molded body is inserted into the portion to blow-mold the core pad with the joining material integrated, and then one side of the non-woven fabric related to the sheet-shaped joining material is the lower mold. The core pad with the bonding material is set on the upper cavity surface of the foam molding mold, and then the flexible polyurethane foam raw material is injected onto the lower cavity surface and the mold is closed, and then the mold is closed. A vehicle seat pad characterized in that the contact surface portion is formed on the design surface side, and the surface layer pad of a flexible polyurethane foam in which the inner surface side is inserted into the one-sided non-woven fabric portion of the bonding material to be joined and integrated is foam-molded. It is in the manufacturing method of. The method for manufacturing a vehicle seat pad according to the ninth aspect of the present invention is the eighth invention , wherein the nonwoven fabric is mechanically entwined with the base layer of the spunbonded nonwoven fabric layer and at least on the core pad side of the base layer with brushing. It is characterized in that the outer layer and the outer layer are bonded and laminated. The method for manufacturing a vehicle seat pad according to the tenth invention is the eighth or ninth invention, in which the core pad is based on a polypropylene resin, while the non-woven fabric has a base layer of PET fibers and at least polypropylene fibers on the core pad side. It is characterized in that it is laminated by connecting it with an outer layer. The method for manufacturing a vehicle seat pad according to the eleventh invention is the eighth to tenth inventions , wherein an undercut portion is formed on a side wall near the lower surface of the core pad, and the portion of the undercut portion is covered from the upper surface side of the core pad. The surface pad that reaches the lower surface of the core pad is foam-molded. The method for manufacturing a vehicle seat pad according to the twelfth invention is the eighth to eleventh inventions, in which a collar portion protruding outward from the side wall of the core pad is integrally formed by blow molding of the core pad, and then the surface layer. It is characterized in that the collar portion is embedded by foam molding of a pad. The method for manufacturing a vehicle seat pad according to the thirteenth invention is the eighth to twelfth inventions, in which a mounting portion for fixing a connection to a vehicle body is integrally formed on a side wall of a core pad by the blow molding, and then foam molding of the surface layer pad is performed. It is characterized in that the mounting portion is made to protrude to the outside of the surface layer pad.

In the vehicle seat pad of the present invention and the method for manufacturing the same, a bonding material is interposed between the surface pad and the core pad made of a blow-molded product to enhance the bonding force, and the core pad is made into a blow-molded hollow body. In addition to reducing the weight, it is possible to provide a collar for strengthening the coupling force between the two and a vehicle body mounting part, which is an excellent effect.

It is a perspective view of the seat pad in one form of the seat pad of this invention and the manufacturing method thereof. FIG. 2 is a view taken along the line II-II of FIG. It is an enlarged view in a circle of FIG. In the partially enlarged view of FIG. 3, (a) is a two-layered non-woven fabric having a base layer and an outer layer, and (b) is a three-layered non-woven fabric having the base layer in the center and the outer layers laminated on both sides. It is a VV line arrow view of FIG. It is a VI-VI line arrow view of FIG. It is a bottom view of the core pad. It is a vertical cross-sectional view which set the bonding material on the mold surface of the blow molding mold in the mold open state. It is an enlarged view in a circle of FIG. 8 (b). (A) is a vertical cross-sectional view of the parison extruded from the die after FIG. 8 (a), and (b) is another aspect view. After FIG. 10, it is a vertical cross-sectional view in which the mold is closed, gas is blown into the parison, and the parison is pressed against the mold surface. It is explanatory cross-sectional view which sets the core body with a joint material in the upper mold, and injects a foaming raw material. It is explanatory cross-sectional view which closed the mold. It is explanatory cross-sectional view which finished foam molding of a surface layer pad.

Hereinafter, the vehicle seat pad (hereinafter, also simply referred to as “seat pad”) and the manufacturing method thereof according to the present invention will be described in detail. 1 to 14 are one form of the seat pad of the present invention and a method for manufacturing the same. FIG. 1 is a perspective view of the seat pad, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a circle of FIG. Enlarged view, FIG. 4 is a partially enlarged view of FIG. 3, FIG. 5 is a VV line cross section of FIG. 2, FIG. 6 is a VI-VI line cross section of FIG. 2, and FIG. 7 is a bottom view of the core pad. 8 is a cross-sectional view in which the bonding material is set on the mold surface of the blow molding mold in the open mold state, FIG. 9 is an enlarged view in the circle of FIG. FIG. 11 is a cross-sectional view in which the mold is closed after FIG. 10 and gas is blown into the parison to press the parison against the mold surface. FIG. A cross-sectional view, FIG. 13 is a cross-sectional view in which the mold is closed, and FIG. 14 is a cross-sectional view in which foam molding of the surface pad is completed. In addition, in order to make each figure easy to understand, the main part of the invention is highlighted for simplification.

(1) Vehicle Seat Pad The vehicle seat pad S is a back pad for a backrest and a cushion pad that supports the lower body of a seated occupant. This embodiment is applied to a cushion pad as shown in FIG. 1 of the rear seat of a vehicle. If the cushion pad is covered with a skin to form a seat cushion, a seat back with a known back pad covered with a skin and a known headrest form a rear seat with an auxiliary seat added to the center in the vehicle width direction. do.
The seat pad S includes a core pad 1, a joining material 2, and a surface pad 5 (FIG. 2). In FIG. 2, the horizontal left direction of the paper is the front of the vehicle, and in FIG. 1, the diagonally upper right direction of the paper is the front of the vehicle.

The core pad 1 is a blow-molded product formed in a hollow molded body of thermoplastic plastic, and has a size that occupies the lower half of the seat pad S (FIG. 2). In the core pad 1, the hollow main body 1A and the flange portion 1B protruding outward from the side wall 13 of the hollow main body 1A are integrally molded by blow molding. The flange portion 1B is integrally molded by effectively utilizing the burr portion that appears on the parting line during blow molding of the hollow body 73 shown in FIG. 11, and is provided at a substantially intermediate height of the hollow body side wall 13. Be done. The collar portion 1B is embedded in the surface layer pad 5 (details will be described later), and is integrally strengthened with the surface layer pad 5. An eaves-shaped collar portion 1B is provided along the side wall 13 of the hollow main body over substantially the entire circumference, and the core pad 1 is provided with a mounting portion 15 as shown in FIG. 7 by deforming a part of the collar portion 1B. Be done. A part of the collar portion 1B is formed in a mounting portion 15 having a through hole 150 (or a notch) for fixing the connection to the vehicle body by changing its shape into a bent piece shape and protruding to the outside of the surface layer pad 5 ( Figure 6). The mounting portion 15 may be separated without being connected to the flange portion 1B as shown in FIG.
The core pad 1 of the present embodiment is made of polypropylene resin, and a non-woven fabric having a polypropylene fiber outer layer 3B on the core pad 1 side is also used for the bonding material 2 (details will be described later).

In the core pad 1, the hollow main body 1A is embedded in the surface pad 5 together with the flange portion 1B, but the lower surface of the hollow main body 1A is an exposed surface 19. While the exposed surface 19 is formed gently and uniformly, a recess 12 that is partially recessed toward the upper surface is formed. Here, the "upper surface" on the upper surface side of the core pad 1 in the present invention means the surface on the side where the occupant comes into contact with the back pad, and the "lower surface" means the surface on the opposite side. Speaking of the cushion pad in which the seat pad S is in the state of FIG. 2 installed in the vehicle, the "upper surface" on the upper surface side of the core pad 1 literally becomes the upper surface of the core pad 1 on the paper surface of FIG. The "lower surface" is also literally the lower surface of the hollow body 1A. The recess 12 has a recess 123 for holding the set in the foam molding mold T in the shape of a square hole, and a recess 124 for strengthening the core pad 1 running in the vehicle width direction like the wavy groove in FIG. , There is. In the strength reinforcing recess 124, the vertical wall portion where the lower surface 1b side of the core pad is recessed and reaches the back surface side of the upper surface 1a of the core pad serves as a reinforcing column, and the portion of the hollow core body that receives the load of the seated occupant is strengthened. ..
The core pad 1 also tilts toward the center of the core pad 1 as the side wall 13 near the lower surface approaches the lower surface 1b of the core pad to form the undercut portion 14. The surface layer pad 5 covers the portion of the undercut portion 14 from the upper surface 1a side of the core pad and reaches the lower surface 1b of the core pad.

The surface pad 5 is a foam-molded product whose outer shape is molded into the shape of a cushion pad seat using a foamed resin raw material such as a polyurethane material. At least the contact surface portion 51 on the side where the occupant comes into contact is formed of a flexible polyurethane foam molded product. A surface pad 5 provided with a contact surface portion 51 on the design surface 5a side with which the occupant abuts and the inner surface 5b conforming to the upper surface shape of the core pad 1 covers the upper surface 1a of the core pad 1. Then, the side wall 13 of the core pad 1 and the flange portion 1B are embedded in the side wall portion 55 of the surface layer pad 5 while leaving the lower surface 1b of the core pad as the exposed surface 19. The flange portion 1B suppresses the arbitrary movement of the core pad 1 with respect to the surface pad 5.
The surface pad 5 here includes a main portion 5A on which the occupant sits, a side portion 5B that rises on both outer sides of the main portion and supports the side portions of the buttocks and thighs related to the occupant, and an auxiliary seat portion 5C. (FIGS. 1 to 6). As described in FIG. 2, the side wall portion 55 on the front side of the vehicle is connected to the contact surface portion 51 at the upper end of the surface pad 5, and the corresponding surface portion 51 gradually increases in thickness toward the rear of the vehicle, and the buttock portion of the occupant. It becomes the maximum in the part that supports. After that, the thickness is reduced to form the slope 5D, which reaches the mating portion 5E with the back pad.

The joining material 2 is a sheet-like member made of a non-woven fabric 3 (FIG. 3). The seat pad S is obtained by setting the core pad 1 in the foam molding mold T for the surface pad 5 and integrally molding the surface pad 5 by embedding the core pad 1. It is difficult to make it. The adhesive strength of the surface pad 5 of the flexible polyurethane foam molded product to the core pad 1 of the blow-molded product made of polypropylene resin or the like is poor, and it is difficult to bond.
Therefore, a sheet-shaped bonding material 2 made of the non-woven fabric 3 is interposed between the surface layer pad 5 and the core pad 1 to connect the two. In the bonding material 2, the inner surface 5b of the surface layer pad 5 is joined and integrated with the non-woven fabric portion 32 on the upper surface side (one surface side), and the upper surface 1a side of the core pad 1 is inserted into the non-woven fabric portion 31 on the lower surface side (other surface side) to be joined and integrated. do. Here, the "upper surface" on the upper surface side of the joining material 2 in the present invention means the surface on the side where the occupant comes into contact, like the upper surface of the core pad 1, and the "lower surface" means the surface on the opposite side. ..

As shown in FIG. 3, in the bonding material 2, the inner surface 5b side of the surface layer pad 5 is joined and integrated with the upper surface side (one surface side) non-woven fabric portion 32, and the upper surface 1a side of the core pad 1 enters the lower surface side (other surface side) non-woven fabric portion 31. Is joined and integrated with the non-woven fabric 3. In the present embodiment, the non-woven fabric configuration is such that the parison 72 at the time of blow molding for forming the core pad 1 does not enter the non-woven fabric portion 32 on the upper surface side. As shown in FIG. 4A, the parison 72 at the time of blow molding penetrates into the non-woven fabric portion 31 on the lower surface side of the bonding material 2, but is set so as to stay in the outer layer 3B of the non-woven fabric portion 31 on the lower surface side.

Specifically, the base layer 3A of the spunbonded non-woven fabric layer and the outer layer 3B of the non-woven fabric layer that has brushes on at least the core pad 1 side of the base layer 3A and are mechanically entwined are bonded and laminated. The basis weight of the nonwoven outer layer 3B in the range of 100g / m ² ~400g / m ^2, but the basis weight of the base layer 3A is set larger than the basis weight of the outer layer 3B, pack eye network. With these configurations, it becomes difficult for the parison 72 to stay in the outer layer 3B and advance into the base layer 3A by blow molding of the core pad 1.
The spunbonded non-woven fabric of the spunbonded non-woven fabric layer is a non-woven fabric having a network structure in which resin chips are melted to form threads and deposited as they are on a conveyor to form a web and bonded in a sheet shape in the same manner as in ordinary spinning. The base layer 3A of the spunbonded non-woven fabric layer is bonded to the outer layer 3B having a raised non-woven fabric layer that is mechanically entangled, and the mechanically entangled non-woven fabric is formed by a needle punch, a fluid punch, or the like. In the method using a needle punch, the web is pierced with a needle and the fibers of the outer layer 3B are entangled with the base layer 3A. Here, even in the case of the two-layer non-woven fabric as shown in FIG. 4A, in which the outer layer 3B having a small basis weight on the core pad 1 side does not penetrate the base layer 3A having a large basis weight, the outer layer 3B on the core pad 1 side penetrates the base layer 3A. It doesn't matter what you have. A three-layer non-woven fabric (b in FIG. 4) in which the outer layer 3B is also provided on the surface pad 5 side may be used as another embodiment product.

More specifically, the non-woven fabric 3 as the bonding material 2 is compositely laminated by bonding the PET fiber base layer 3A and at least the polypropylene fiber outer layer 3B on the core pad 1 side, and the core pad 1 is based on the polypropylene resin. do. With such a configuration, in the blow molding of the core pad 1, the parison 72 penetrates into the outer layer 3B of the raised non-woven fabric of the bonding material 2, and the upper surface 1a side of the core pad 1 penetrates into the non-woven fabric portion 31 on the lower surface side of the non-woven fabric 3. Join and integrate. Then, the outer layer 3B is made of polypropylene fiber, and by adopting the polypropylene resin-based core pad 1 having excellent compatibility, the core pad 1 with the bonding material 2 whose bonding force is further enhanced is obtained. The core pad 1 enters the brushed outer layer 3B and melt-bonds.
Here, there is a possibility that the parison 72 of the core pad 1 in blow molding exceeds the outer layer 3B of the non-woven fabric portion 31 on the lower surface side and impregnates into the base layer 3A region. However, the parison 72 has a high viscosity, and the base layer 3A of the spunbonded non-woven fabric layer is more difficult to penetrate the parison 72 than the outer layer 3B which is mechanically entangled. Furthermore, the basis weight is large and the mesh structure is tight, so that the infiltration of parison can be stopped before the base layer 3A. The parison 72 stays in the outer layer 3B at the stage of being formed into the hollow body 73 for the core pad 1, and the appearance of the base layer 3A having a network structure remains after blow molding. In addition, in the base layer 3A of the PET fiber, even if the polypropylene resin parison 72 infiltrates the base layer 3A, it does not melt, and the network structure of the base layer 3A can be easily maintained.

The joining material 2 is also integrated with the surface pad 5 on the base layer 3A side opposite to the outer layer 3B (a in FIG. 4). In the foam molding of the surface layer pad 5, the inner surface 5b side of the surface layer pad 5 is on the base layer 3A side of the network structure opposite to the surface of the bonding material 2 joined and integrated with the core pad 1, so to speak, on the upper surface side non-woven fabric portion 32. It goes in and joins and integrates. The foaming raw material g to be the surface pad 5 impregnates the bonding material 2 in the middle of foaming to join and integrate. In the three-layer non-woven fabric (b in FIG. 4) in which the outer layer 3B is provided on the surface pad 5 side, the surface pad is on the upper surface side non-woven fabric portion 32 which is the outer layer 3B side on the surface pad 5 side, and further up to the base layer 3A depending on the situation. The inner surface 5b side of 5 enters and is joined and integrated.
As described above, in the seat pad S of the present invention, the surface layer pad 5 and the core pad 1 interpose the joining material 2 to strongly and surely bond and integrate, and the core pad 1 of the blow molded product realizes weight reduction. The desired seat pad S is finished. Reference numeral 53 indicates a foam-molded portion of the surface pad 5 that fills the undercut portion 14, and reference numeral 59 indicates a suspension groove such as a vertical groove 591 and a horizontal groove 592.

(2) Manufacturing Method of Seat Pad for Vehicle The seat pad S is manufactured by, for example, the following manufacturing method. Using the joining material 2, the blow molding mold 6, and the foam molding mold T, first, the joining material 2 is set in the blow molding mold 6 and the core pad 1 is blow molded to obtain the core pad 1 with the joining material 2. After that, the core pad 1 with the joining material 2 is set in the foam molding mold T (FIG. 12), and the inner surface 5b is joined and integrated with the non-woven fabric portion 32 (exposed side) on the upper surface side (one side) of the joining material 2 (FIG. 12). This is a method for manufacturing a sheet pad for foam-molding the surface pad 5 of a foam (FIG. 14).

The joining material 2 is a sheet-like body made of a non-woven fabric. The joining material 2 is the same as that described in (1) Seat pad, and detailed description thereof will be omitted. This embodiment also uses the non-woven fabric bonding material 2 as shown in FIG. 4 (a), and will be described based on this.

The blow molding mold 6 is a known device for manufacturing a blow molded product, and is between a pair of split molds 6A and 6B in which the outer shape of the core pad 1 which is a blow molded product is formed on the mold surface 61 and the double split molds 6A and 6B. A die 71 for extruding a tubular parison 72 and a die 71 are provided (FIG. 10). For example, a joining material set pin 64 is provided on the split die (one split die) 6A for forming the upper surface 1a side of the core pad so that the sheet-shaped joining member 2 can be set (a in FIG. 8). Further, when the joint material 2 of the molded felt (molded non-woven fabric) molded in advance according to the mold surface shape of the split mold 6A is used, the mold surface 61 of the split mold 6A is provided with a recess 611 for setting the joint material 2. (B in FIG. 8). By attaching the joining material 2 to the one split mold 6A with the top surface side (one side) non-woven fabric portion 32 facing the mold surface of one split mold 6A, the joining material 2 is set between the pair of split molds 6A and 6B. Next, the parison 72 is extruded from the die 71 between the split molds 6A and 6B in the open mold state (specifically, between the joining material 2 and the other split mold 6B), and the parison 72 is placed in the split molds 6A and 6B. Put it in. It is a blow molding device that can blow gas into the sandwiched parison 72 with a blow pin (not shown) and press the parison 72 against the mold surface 61 with the pressure to form the hollow body 73 for the core pad 1 with the joining material 2 (FIG. 8). ~ FIG. 11). Reference numeral 623 indicates a protrusion for forming the set holding recess 123 of the core pad 1, reference numeral 624 indicates a protrusion for forming the strength reinforcing recess 124 of the core pad 1, and reference numeral 69 indicates a cut-out protrusion. ..

The foam molding mold T is a split mold as shown in FIG. 12, and includes a lower mold 8 and an upper mold 9. On the upper cavity surface 91, a convex portion 923 for holding the set of the core pad 1 with the joining material 2 and a convex portion 924 for strengthening the core pad 1 are formed. When the core pad 1 with the joining material 2 is set on the upper cavity surface 91 and the mold is closed as shown in FIG. 13 with the hinge hg as a fulcrum, the lower cavity surface 81 having a large degree of denting as a whole and a partially convex portion 92 are partially formed. Cavity C of the seat pad S containing the core pad 1 with the joining material 2 is formed by the substantially flat upper die cavity surface 91. In the foam molding of FIGS. 12 to 14, the design surface side of the seat pad S is formed on the lower die cavity surface 81, and the back surface side of the seat pad S is formed on the upper die cavity surface 91.

The seat pad S is manufactured, for example, as follows by using the bonding material 2, the blow molding mold 6, and the foam molding mold T.
First, under the mold open state, the joining material 2 is set in the split mold 6A with the top surface side (one side) non-woven fabric portion 32 facing the mold surface 61 of the split mold 6A (FIG. 8). The set of the joining material 2 is not limited to the form of being attached to the split mold 6A (a in FIG. 8), and a clamp 65 or the like is used on the split mold 6A side between the split molds 6A and 6B as shown in FIG. 10 (b). You may hang it. In the bonding material 2 of the present embodiment, the PET fiber base layer 3A of the spunbonded non-woven fabric layer and the polypropylene resin fiber outer layer 3B having a raised non-woven fabric layer mechanically entwined with at least the core pad 1 side of the base layer 3A are bonded. It is a two-layer non-woven fabric (FIG. 4A, FIG. 9). Moreover, the basis weight of the base layer 3A is larger than that of the outer layer 3B. The upper surface (one surface) 3a of the base layer 3A side non-woven fabric of the bonding material 2 is directed to the mold surface 61 of one split mold 6A of the blow molding mold 6 that can be opened and closed so that the parison 72 can be sandwiched, and the lower surface of the non-woven fabric 3 on the outer layer side. With the (other surface) facing the other split mold 6B, the bonding material 2 made of the non-woven fabric 3 is set in the one split mold 6A.
Although not shown, even when the bonding material 2 is the three-layer non-woven fabric shown in FIG. 4 (b), the lower surface of the non-woven fabric on the outer layer 3B side is set toward the other split mold 6B. When a molded non-woven fabric (molded felt) molded according to the mold surface shape of one of the split molds 6A is used, the upper surface 3a side of the non-woven fabric 3 is formed into the mold surface recess 611 of the blow molding mold 6 as shown in FIG. Set them in contact with each other.

Next, under the mold open state, the parison 72 is lowered from the die 71 between the pair of split molds 6A and 6B (FIG. 10). At this time, the parison 72 descends between the bonding material 2 and the other split mold 6B. Subsequently, the parison 72 is sandwiched between the split molds 6A and 6B, and air is blown into the parison 72 in the sandwiched mold closing cavity 60 using a blow pin (not shown). The parison 72 in the mold closing cavity 60 was inflated, and a part of the wall surface of the hollow body 73 was infiltrated into the joint material 2 to form a hollow body 73 with the joint material 2 integrated therein, which was eventually formed into a hollow molded body. Blow molding of the core pad 1 with the joining material 2 in which the joining material 2 is joined and integrated with the upper surface 1a of the core pad 1 is completed. A core pad 1 with a joining material 2 is formed in which the upper surface 1a side of the core pad enters the non-woven fabric portion 31 on the lower surface side of the joining material 2 and is joined and integrated (FIG. 11). In blow molding, the protrusion 623 provides the set holding recess 123, and the protrusion 624 provides the strength reinforcing recess 124. When the parison 72 is changed to the hollow body 73 by this blow molding, the excess burr 79 is removed by the biting protrusion 69, but on the parting line, a part of the burr is integrated with the hollow body 1A. , It is molded into the mounting portion 15. The core pad 1 is a blow-molded product in which the flange portion 1B and the mounting portion 15 are integrated with the hollow main body 1A. The mold is opened and removed, and burrs other than the flange portion 1B and the mounting portion 15 are removed to obtain a core pad 1 with a joining material 2 as shown in FIG.

Subsequently, the upper surface 3a of the non-woven fabric of the joining material 2 is exposed so as to face the lower mold 8, and the core pad 1 with the joining material 2 is set on the upper die cavity surface 91 of the foam molding die T (FIG. 12). Since the seat pad S is molded upside down in the foam molding mold T in which the lower surface 1b of the core pad is brought into contact with the upper mold cavity surface 91, the upper surface 3a of the non-woven fabric is set in the upper mold 9 so as to face the lower mold 8. NS. The convex portion 923 of the upper die 9 is inserted into the set holding recess 123, and the core pad 1 with the joining material 2 is kept locked to the upper die 9.

After that, the flexible polyurethane foam raw material is injected onto the lower mold cavity surface 81 and the mold is closed. A predetermined amount of the foaming raw material g for sheet pad molding is injected onto the lower mold cavity surface 81 in the mold open state using an injection hose NL or the like.
Then, the upper mold 9 is operated to close the mold (FIG. 13). By closing the upper mold 9 and the lower mold 8, a cavity C for a seat pad in which the core pad 1 with the joining material 2 is insert-set is formed.

After closing the mold, the process moves to the main process of foam molding. A contact surface portion 51 is formed on the design surface 5a side, and the foaming material g is impregnated in the non-woven fabric portion 32 on the upper surface side of the bonding material 2, so that the inner surface 5b side enters the non-woven fabric portion 32 on the upper surface side and is joined and integrated. The surface pad 5 of the body is foam-molded (FIG. 14). The surface pad 5 is foam-molded so that the flange portion 1B is embedded and the portion of the undercut portion 14 formed on the side wall 13 near the lower surface of the core pad 1 is covered from the upper surface 1a side of the core pad to reach the lower surface 1b of the core pad. The core pad 1 is embedded in the surface pad 5, but the lower surface 1b thereof is left as an exposed surface 19.

Here, in the present embodiment, the PET fiber base layer 3A of the spunbonded non-woven fabric layer and the polypropylene fiber outer layer 3B of the non-woven fabric layer having brushes on at least the core pad 1 side of the base layer 3A and mechanically entwined are bonded and laminated. The bonded material 2 is used. In the core pad 1 with the bonding material 2 in which the bonding material 2 is integrated by blow molding of the core pad 1, the non-woven fabric portion 32 on the upper surface side of the bonding material 2 maintains the mesh structure of the non-woven fabric as described above. In the initial stage of foam molding after the mold is closed, the foaming raw material g is foamed from the state shown in FIG. 13, and the upper surface thereof rises. Eventually, it reaches the upper surface of the joining material 2. The parison 72 has not penetrated into the base layer 3A on the upper surface side of the bonding material 2 by the previous blow molding, and the non-woven fabric having a mesh structure is maintained. The foaming raw material g enters between the fibers of the non-woven fabric. A part of the foaming raw material g penetrates into the interfibers of the non-woven fabric portion 32 on the upper surface side of the bonding material 2, and is eventually cured. The foamed raw material g soaked into the non-woven fabric portion 32 on the upper surface side is entangled with the non-woven fabric portion to form a cured flexible polyurethane foam-molded bonded portion. In FIG. 4A, the flexible polyurethane foam-molded bonding portion is shown by a hatched cross-sectional view of the surface layer pad 5 that has entered the base layer 3A.
Further, the foaming raw material g is foamed, and the flange portion 1B protruding from the core pad side wall 13 is embedded to raise the upper surface thereof, and further covers the undercut portion 14 to reach the upper cavity surface 91.

In this way, the cavity C is filled with the foam of the foaming material g, and the foam molding of the surface layer pad 5 made of the soft polyurethane foam in which the inner surface 5b side enters the upper surface side of the bonding material 2 and is bonded and integrated is completed (FIG. 14). .. On the side wall 13 of the core pad 1, a mounting portion 15 for fixing a connection to a vehicle body integrally formed by blow molding projects to the outside of the surface pad 5 (FIGS. 1 and 6). When the foam molding is completed and the mold is removed, the weight can be reduced by adopting the core pad 1 of the blow molded product having the hollow portion 10, and the core pad 1 and the surface layer pad 5 have a bonding force via the bonding material 2. The desired seat pad S is completed. Reference numeral 84 indicates a lateral groove forming portion, and reference numerals 89 and 99 indicate a mold matching surface.

(3) Effect According to the vehicle seat pad and the manufacturing method thereof configured as described above, the seat pad S is formed into a hollow molded body having gas inside and is occupied by the lightweight core pad 1, so that the weight is lightweight. Can be realized.
Then, when the joining material 2 made of the non-woven fabric 3 is interposed between the surface layer pad 5 and the core pad 1, the joining material 2 is in the middle to connect the surface layer pad 5 and the core pad 1. Since the core pad 1 is blow-molded and enters the non-woven fabric portion 31 on the lower surface side of the joining material 2 to be joined and integrated, the joining material 2 is strongly bonded and integrated with the core pad 1 unlike fixing such as simple adhesion. ..
On the other hand, on the upper surface side of the joining material 2, the inner surface 5b side of the surface layer pad 5 can enter into the upper surface side non-woven fabric portion 32 and can be joined and integrated. Unlike fixing, the joining material 2 is strongly bonded and integrated with the core pad 1. Even if the seat pad S is a large product in which the core pad 1 is arranged in the lower half and the exposed surface 19 is provided on the lower surface 1b of the core pad, the surface pad 5 is less likely to be peeled off from the core pad 1, and the surface pad 5 and the joining material are joined. The bond integrity of 2 is improved. The connection between the surface layer pad 5 and the core pad 1 is strengthened via the joining material 2.

Then, the bonding material 2 is made of the non-woven fabric 3, and the base layer 3A of the spunbonded non-woven fabric layer and the outer layer 3B of the non-woven fabric layer which has brushes on at least the core pad 1 side of the base layer 3A and is mechanically entangled are bonded. When laminated, the parison 72 can smoothly penetrate into the non-woven fabric layer that has brushing and is mechanically entangled by blow molding of the core pad 1, and even if it penetrates, the long fibers are made into a web and the fibers are pressure-bonded to each other. Since the spunbonded non-woven fabric layer has a large penetration resistance, the parison 72 stays at the non-woven fabric portion 31 on the lower surface side of the joining material 2 and is joined and integrated. The upper surface 3a side of the non-woven fabric remains as it is. If the basis weight of the base layer 3A is larger than that of the outer layer 3B, the penetration resistance of the spunbonded non-woven fabric layer becomes even larger. Therefore, even after blow molding of the core pad 1, the mesh structure on the upper surface 3a side of the non-woven fabric is before blow molding. Can be left in shape. Thus, in the subsequent foam molding of the surface layer pad 5, the inner surface 5b side of the surface layer pad 5 enters the non-woven fabric upper surface 3a side, and the bonding force between the surface layer pad 5 and the bonding material 2 is increased unlike simple adhesion.
Further, while the core pad 1 is based on a polypropylene resin, when the non-woven fabric 3 is laminated by bonding the base layer 3A of the PET fiber and at least the outer layer 3B of the polypropylene fiber on the core pad 1 side, the bonding force is further enhanced. It becomes a core pad 1 with an increasing bonding material 2. This is because, at the time of blow molding of the core pad 1, the parison 72 soaks into the compatible outer layer 3B and melt-bonds with the outer layer 3B.
Furthermore, when the core pad 1 is a blow-molded product in which the collar portion 1B protruding outward from the side wall 13 of the hollow body 1A is integrally formed, and the collar portion 1B is embedded in the surface layer pad 5, the collar portion 1B Restricts the peeling of the surface pad 5 from the core pad 1, so that the integration of the core pad 1 and the surface pad 5 becomes solid.

Further, in order to attach the seat pad S to the vehicle body, a separate attachment portion 15 is required for the seat pad S. When the portion 15 is provided, a separate mounting portion 15 is not required. In the conventional bead foam molded body used for weight reduction, a separate part of the metal mounting portion 15 is incorporated by insert molding, but the present invention does not require the trouble of incorporating and there is a concern that the weight may increase due to the metal part. No. Further, unlike the bead foam molded product whose dimensional accuracy cannot be improved, the core pad 1 of the blow-molded product having a certain external dimension has a mounting portion 15 having a high mounting position accuracy.
In addition, the collar portion 1B and the mounting portion 15 can be integrally formed with the hollow body 1A, the collar portion 1B, and the mounting portion 15 by processing the burr portion formed on the parting line by blow molding of the core pad 1. Therefore, there is no need for separate parts for the mounting part, and inventory management is not required. It is extremely beneficial because it can be handled at low cost while maintaining productivity.

Further, an undercut portion 14 is formed on the side wall 13 near the lower surface of the core pad 1, and the surface pad 5 covers the portion of the undercut portion 14 from the upper surface side of the core pad 1 by foam molding of the surface layer pad 5. The undercut portion 14 also helps prevent the surface pad 5 from peeling off from the core pad 1.
Further, if the core pad 1 is provided with the set holding recess 123, it becomes easy to set the surface pad 5 in the foam molding mold T at the time of foam molding. Further, when the core pad 1 is provided with the strength reinforcing recess 124, the hollow main body 1A is located in the large core pad 1 and the required strength can be easily secured.
As described above, the seat pad S for this vehicle and its manufacturing method realize weight reduction by using the core pad 1 of a blow-molded product made of a hollow molded body having only gas inside, and the core pad 1 and the surface layer pad 5. The number of parts can be reduced by integrally strengthening the mounting portion 15 and integrally molding the mounting portion 15, which is effective in improving fuel efficiency, stabilizing quality, and reducing cost due to weight reduction.

In the present invention, the present invention is not limited to the one shown in the above embodiment, and various modifications can be made within the scope of the present invention according to the purpose and application. The shape, size, number, material, etc. of the core pad 1, the joining material 2, the surface pad 5, the blow molding mold 6, the foam molding mold T, etc. can be appropriately selected according to the application. Although the embodiment is applied to a cushion pad, it can also be applied to a back pad for a backrest. The collar portion 1B does not have to be on the entire circumference of the core pad 1. It may be partially provided on the outer circumference of the core pad 1.

1 core pad 1A hollow body 1B collar
10 Hollow part
13 Side wall 14 Undercut part 15 Mounting part 2 Joining material 3 Non-woven fabric 3a Non-woven fabric top surface (one side of non-woven fabric)
32 Top side non-woven fabric part (one side non-woven fabric part)
5 Surface pad 5a Design surface 5b Inner surface 51 Seated occupant contact surface 6 Blow molding type 61 Mold surface (split mold surface)
73 Hollow body 8 Lower mold (Lower mold of foam molding mold)
81 Lower mold cavity surface g Foaming material S Seat pad T Foam molding mold

Claims (8)

A vehicle seat pad in which at least the contact surface portion on the side where the occupant comes into contact is made of a flexible polyurethane foam molded product.
A blow-molded product formed in a hollow molded body of thermoplastic plastic, and a core pad having a flange portion integrally formed on the parting line from the outer side wall of the hollow portion and projecting outward.
In the flexible polyurethane foam moldings, wherein the contact surface portion is formed on the design surface side Rutotomoni, covering the upper surface of and core pad is embedded the flange portion, the core pad and surface layer are integrally molded With the pad
It is interposed between the surface pad and the core pad, and is made of a non-woven fabric. A vehicle seat pad characterized by being provided with an integrated bonding material. The non-woven fabric is laminated by bonding the base layer of the spunbonded non-woven fabric layer and the outer layer of the non-woven fabric layer that has brushes on at least the core pad side of the base layer and is mechanically entwined, and is more than the basis weight of the outer layer. The vehicle seat pad according to claim 1 , wherein the base layer has a large basis weight. The vehicle according to claim 1 or 2, wherein the core pad is based on a polypropylene resin, while the non-woven fabric is laminated by bonding a base layer of PET fibers and at least an outer layer of polypropylene fibers on the core pad side. Seat pad. Claims 1 to 3 have an exposed surface on the lower surface of the hollow main body related to the core pad, and a recess is partially formed on the upper surface side while the exposed surface is formed gently and uniformly. The vehicle seat pad according to any one of the above. The core vehicle seat pad according to any one of claims 1 to 4 undercut portion is formed on the lower surface near the side wall of the pad. The vehicle seat pad according to any one of claims 1 to 5, wherein the surface layer pad reaches the lower surface of the core pad by embedding the collar portion from the upper surface side of the core pad. It is a method for manufacturing a vehicle seat pad in which at least the contact surface portion on the side where the occupant comes into contact is made of a flexible polyurethane foam molded product.
In a blow molding die for molding a core pad, one side of a sheet-shaped bonding material made of a non-woven fabric is directed toward one split mold surface for molding the upper surface side of the core pad, and the sheet-shaped bonding material is split between the split molds. After setting in, the upper surface side of the core pad formed in the hollow molded body is inserted into the non-woven fabric portion on the other side of the joint material to blow-mold the core pad with the joint material integrated by joining, and the blow-molding is performed. , When the parison is made into a hollow body, a collar portion integrated with the hollow body is formed from the side wall on the outside of the hollow portion on the parting line to obtain the core pad with the joining material, and then the sheet-shaped joining material is applied. The non-woven fabric is exposed so that one side faces the lower mold, the core pad with a bonding material is set on the upper cavity surface of the foam molding mold, and then the soft polyurethane foam raw material is injected onto the lower cavity surface. After that, the contact surface portion is formed on the design surface side, the flange portion is embedded, and the inner surface side is inserted into the one-sided non-woven fabric portion of the bonding material to join and integrate the flexible polyurethane foam. A method for manufacturing a vehicle seat pad, which comprises foam-molding a surface pad. The method for manufacturing a vehicle seat pad according to claim 7, wherein the collar portion is embedded from the upper surface side of the core pad, and the surface layer pad reaching the lower surface of the core pad is foam-molded.

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