JP2019024534A - Vehicle seat pad and method for manufacturing the same - Google Patents

Abstract

To provide a vehicle seat pad which improves connectivity with a soft polyurethane foam molding while using a blow molding for a part and to reduce weight, and a method for manufacturing the same.SOLUTION: A vehicle seat pad S which forms a contact surface part 51 on the side with which at least a crew member is in contact with a soft polyurethane foam molding includes: a core pad 1 of a blow molding product formed in a hollow molding of thermoplastic resin; a surface layer pad 5 which is a soft polyurethane foam molding, forms the contact surface part 51 on its design surface 5a, is formed into an upper surface shape of the core pad 1 in the way that an inner surface 5b goes along, and covers an upper surface 1a of the core pad 1; and a bonding material 2 which is intervened between the surface layer pad 5 and the core pad 1, is composed of non-woven fabric 3, is integrally bonded by the inner surface 5b side of the surface layer pad 5 entering into a one surface side non-woven cloth part 32, and is integrally bonded by the upper surface 1a of the core pad 1 entering into the other surface side non-woven cloth part 31.SELECTED DRAWING: Figure 2

Description

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

  Conventionally, a seat pad constituting a seat portion and a backrest of a vehicle seat such as an automobile has been conventionally made of a flexible polyurethane foam molded article so as to obtain a comfortable cushioning property. However, in recent years, there has been a movement toward reducing the weight of a vehicle by using a bead foam molded body such as a polystyrene foam body to improve fuel efficiency (for example, Patent Document 1).

JP-A-9-70330

However, since the bead foam molded body including Patent Document 1 is shrunk at the time of molding and the dimensional accuracy cannot be increased, it is difficult to set the foam foam mold and it is difficult to integrally form the polyurethane foam molded body. is there.
Therefore, in order to reduce the weight, the present inventor has newly studied to use 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 a thermoplastic resin such as polypropylene resin, and the blow molded body made from this parison is set in a foam mold and an attempt is made to integrally form a flexible polyurethane foam molded body, the binding between the two is poor and the integral It is becoming difficult.

  The present invention solves the above-described problem, and provides a vehicle seat pad and a method for manufacturing the same that achieve good weight and weight reduction while using a blow-molded body as a part while improving the bonding property with a flexible polyurethane foam molded body. For the purpose.

In order to achieve the above object, the gist of the invention described in claim 1 is a vehicular seat pad in which at least a contact surface portion on the side where an occupant abuts is formed of a soft polyurethane foam molded article, A blow molded article core pad formed on the molded body and a soft polyurethane foam molded body are formed so that the contact surface portion is formed on the design surface side and the inner surface is aligned with the upper surface shape of the core pad. A surface pad that covers the upper surface of the core pad, and is interposed between the surface layer pad and the core pad, and is composed of a nonwoven fabric. And a bonding material formed by joining and integrating the upper surface side of the core pad into the surface-side nonwoven fabric portion. A vehicle seat pad according to a second aspect of the present invention is the vehicle seat pad according to the first aspect, wherein the nonwoven fabric has a base layer of a spunbond nonwoven fabric layer and an outer layer of the nonwoven fabric layer that has mechanically entangled with raising at least on the core pad side of the base layer. And the basis weight of the base layer is larger than the basis weight of the outer layer. A vehicle seat pad according to a third aspect of the present invention is the seat pad for a vehicle according to the first or second aspect, wherein the core pad is made of a polypropylene resin base, while the non-woven fabric has a base layer of PET fiber and an outer layer of polypropylene fiber at least on the core pad side. Are combined and laminated. A vehicle seat pad according to a fourth aspect of the present invention is the vehicle seat pad according to the first to third aspects, wherein the lower surface of the hollow main body related to the core pad has an exposed surface, and the exposed surface is formed gently and uniformly. A recess is formed on the upper surface side. A vehicle seat pad according to a fifth aspect of the present invention is the vehicle seat pad according to the first to fourth aspects, wherein an undercut portion is formed on the side wall near the lower surface of the core pad, and the surface layer pad is located on the undercut portion from the upper surface side of the core pad. And reaching the lower surface of the core pad. A vehicle seat pad according to a sixth aspect of the present invention is the blow molded product according to any one of the first to fifth aspects, wherein the core pad is integrally formed with a flange portion protruding outward from the side wall of the hollow body, and the flange portion is the It is embedded in a surface layer pad. A vehicle seat pad according to a seventh aspect of the present invention is the seat pad for a vehicle according to the sixth aspect, wherein the core pad is provided with an attachment portion for fixing the connection to the vehicle body so that a part of the flange portion protrudes outside the surface layer pad. It is characterized by.
The gist of the invention described in claim 8 is a method for manufacturing a vehicle seat pad in which at least a contact surface portion on the side where an occupant abuts is formed of a soft polyurethane foam molded body, wherein the blow pad mold is used to mold a core pad. The sheet-shaped bonding material is set between the molds so that one surface side of the sheet-shaped bonding material made of a nonwoven fabric faces the one mold surface for molding the upper surface side of the core pad. The other side nonwoven fabric portion is blow-molded with a bonding material core pad that is joined and integrated by inserting the upper surface side of the core pad formed in the hollow molded body, and then the nonwoven fabric related to the sheet-like bonding material. The core pad with the bonding material is set on the upper mold cavity surface of the foam mold, with the one surface side exposed to face the lower mold, and then the flexible polyurethane foam raw material is injected onto the lower mold cavity surface and the mold is closed. And Thereafter, a surface layer pad of a soft polyurethane foam is formed by foam molding, wherein the contact surface portion is formed on the design surface side, and the inner surface side enters into the one-side nonwoven fabric portion of the bonding material to be integrated. A method of manufacturing a seat pad for a vehicle. According to a ninth aspect of the present invention, there is provided a vehicle seat pad manufacturing method according to the eighth aspect of the present invention, wherein the nonwoven fabric comprises a base layer of a spunbond nonwoven fabric layer and a nonwoven fabric mechanically entangled with raising at least on the core pad side of the base layer. The outer layers of the layers are combined and laminated. According to a tenth aspect of the present invention, there is provided a vehicle seat pad manufacturing method according to the eighth or ninth aspect, wherein the core pad is made of a polypropylene resin base, while the non-woven fabric has a base layer of PET fiber and at least the polypropylene fiber on the core pad side. The outer layer is bonded and laminated. The vehicle seat pad manufacturing method according to an eleventh aspect of the present invention is the vehicle seat pad manufacturing method according to the eighth to tenth aspects, wherein an undercut portion is formed on the side wall near the lower surface of the core pad, and the portion of the undercut portion is formed from the upper surface side of the core pad. The surface layer pad that covers and reaches the lower surface of the core pad is foam-molded. A method for manufacturing a vehicle seat pad according to a twelfth aspect of the present invention is the method for manufacturing a vehicle seat pad according to the eighth to eleventh aspects, wherein the flange portion protruding outward from the side wall of the core pad is integrally formed by blow molding of the core pad, and thereafter The flange is embedded by foam molding of a surface layer pad. A vehicle seat pad manufacturing method according to a thirteenth aspect of the present invention is the method for manufacturing a vehicle seat pad according to the eighth to twelfth aspects of the present invention, wherein the connection fixing portion for connection to the vehicle body is integrally formed on the side wall of the core pad by the blow molding, and then the foaming of the surface layer pad is performed. The mounting portion protrudes outside the surface layer pad by molding.

  The vehicle seat pad and the manufacturing method thereof according to the present invention include a bonding material interposed between the surface layer pad and the core pad made of the blow molded product to increase the bonding force, and the core pad is made into a blow molded hollow body. This makes it possible to reduce the weight, and to provide a superior effect such as the ability to provide a brim for strengthening the coupling force between the two and a vehicle body mounting part.

It is a perspective view of a seat pad in one form of a seat pad of the present invention, and its manufacturing method. It is the II-II arrow directional view of FIG. FIG. 3 is an enlarged view in a circle of FIG. 2. FIG. 3 is a partially enlarged view of FIG. 3. (a) is a non-woven fabric having two layers of a base layer and an outer layer, and (b) is a three-layer structure in which the non-woven fabric has the base layer in the middle and the outer layers are laminated on both sides. FIG. 5 is a view taken along line VV in FIG. 2. FIG. 6 is a view taken along line VI-VI in FIG. 2. It is a bottom view of a lead pad. It is the longitudinal cross-sectional view which set the joining material to the type | mold surface of the blow molding die of a mold open state. FIG. 9 is an enlarged view in a circle of FIG. FIG. 8A is a longitudinal sectional view in which a parison is extruded from a die after FIG. 8A, and FIG. It is the longitudinal cross-sectional view which closed the type | mold after FIG. 10, blown gas in the parison, and pressed this parison on the type | mold surface. It is explanatory sectional drawing which sets a core with a joining material to an upper mold | type, and inject | pours a foaming raw material. It is explanatory sectional drawing closed mold. It is explanatory sectional drawing which finished foam molding of the surface layer pad.

  Hereinafter, a vehicle seat pad (hereinafter also simply referred to as “seat pad”) according to the present invention and a manufacturing method thereof will be described in detail. 1 to 14 show one embodiment of the seat pad and the manufacturing method thereof according to the present invention, FIG. 1 is a perspective view of the seat pad, FIG. 2 is a view taken along the line II-II in FIG. 1, and FIG. 4 is a partially enlarged view of FIG. 3, FIG. 5 is a view taken along the line VV in FIG. 2, FIG. 6 is a view taken along the line VI-VI in FIG. 2, and FIG. 8 is a cross-sectional view in which a bonding material is set on the mold surface of the blow mold in the mold open state, FIG. 9 is an enlarged view in a circle in FIG. 8, FIG. 10 is a cross-sectional view in which a parison is extruded from a die after FIG. 11 is a cross-sectional view of FIG. 10 after closing the mold, blowing gas into the parison and pressing the parison against the mold surface, and FIG. 12 is an explanation of setting the core with bonding material to the upper mold and injecting the foaming raw material FIG. 13 is a sectional view in which the mold is closed, and FIG. 14 is a sectional view in which foaming of the surface layer pad is completed. It should be noted that, for the sake of clarity, each figure is simplified and the essential parts of the invention are highlighted.

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

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). The core pad 1 is integrally formed with a hollow main body 1A and a flange 1B projecting outward from the side wall 13 of the hollow main body 1A by blow molding. The flange portion 1B is formed by integrally using a burr portion that appears on the parting line during blow molding of the hollow body 73 shown in FIG. It is done. The eaves part 1B is embedded in a surface layer pad 5 (details will be described later), and the reinforcement with the surface layer pad 5 is enhanced. A flange-shaped flange portion 1B is provided over the entire circumference along the hollow body side wall 13. However, the core pad 1 is also provided with a mounting portion 15 as shown in FIG. It is done. A part of the flange portion 1B is formed in the attachment portion 15 having a through hole 150 (or a notch) for fixing the connection to the vehicle body by changing the shape into a bent piece shape and coming out of the surface layer pad 5 (see FIG. (Fig. 6). The attachment portion 15 may be separated without being connected to the flange portion 1B as shown in FIG.
The core pad 1 of this embodiment is made of polypropylene resin, and the bonding material 2 (detailed later) is also made of a nonwoven fabric having a polypropylene fiber outer layer 3B on the core pad 1 side.

In the core pad 1, the hollow body 1 </ b> A is embedded in the surface pad 5 together with the flange 1 </ b> B, but the lower surface of the hollow body 1 </ b> A becomes an exposed surface 19. While the exposed surface 19 is gently and uniformly formed, a recess 12 partially recessed toward the upper surface side is formed. Here, in view of application to the back pad, the “upper surface” on the upper surface side of the core pad 1 in the present invention refers to the surface on the side where the occupant abuts, and the “lower surface” refers to the opposite surface. If the seat pad S is a cushion pad under the vehicle installation state of FIG. 2, 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. "Lower surface" is literally the lower surface of the hollow body 1A. In the recess 12, a recess 123 for holding the foam molding mold T in a square hole shape, and a strength reinforcing recess 124 that runs in the vehicle width direction of the core pad 1 like a wavy groove in FIG. There is. In the strength reinforcing recess 124, the standing wall portion which is recessed on the core pad lower surface 1b side and reaches the back surface side of the core pad upper surface 1a serves as a reinforcing column, and the strength of the hollow core body receiving the load of the seated occupant is increased. .
The core pad 1 also tilts toward the center side of the core pad 1 as the lower surface side wall 13 approaches the core pad lower surface 1b to form an undercut portion 14. The surface layer pad 5 covers the portion of the undercut portion 14 from the core pad upper surface 1a side and reaches the core pad lower surface 1b.

The surface layer pad 5 is a foam molded product whose outer shape is formed into a cushion pad seat portion shape using a foamed resin raw material such as a polyurethane material. At least the contact surface portion 51 on the side on which the occupant abuts is formed of a soft polyurethane foam molded article. A surface layer pad 5 provided with a contact surface portion 51 on the side of the design surface 5a on which the occupant abuts and an inner surface 5b conforming to the upper surface shape of the core pad 1 covers the core pad upper surface 1a. Then, the side wall 13 and the flange 1 </ b> B of the core pad 1 are embedded with the side wall 55 of the surface layer pad 5 while leaving the core pad lower surface 1 b as the exposed surface 19. Arbitrary movement of the core pad 1 with respect to the surface layer pad 5 is suppressed by the collar part 1B.
Here, the surface layer pad 5 includes a main part 5A on which an occupant sits, a side part 5B that protrudes on both outer sides of the main part, and supports side parts of the buttocks and thighs of the occupant, and an auxiliary seat part 5C. (FIGS. 1 to 6). 2, the surface pad 5 is connected to the contact surface portion 51 at the upper end of the side wall portion 55 on the front side of the vehicle, and the thickness of the corresponding surface portion 51 gradually increases toward the rear of the vehicle. It becomes the maximum in the part that supports. Thereafter, the thickness is reduced to form the inclined surface 5D, and reaches the mating portion 5E with the back pad.

The bonding material 2 is a sheet-like member made of a nonwoven fabric 3 (FIG. 3). The seat pad S is obtained by setting the core pad 1 in the foaming mold T for the surface layer pad 5 and embedding the surface pad 5 by embedding the core pad 1. It is difficult to make it. The adhesive force of the surface layer pad 5 of the flexible polyurethane foam molded article to the core pad 1 of a blow molded product made of polypropylene resin or the like is poor and is difficult to bond.
Therefore, the sheet-like bonding material 2 made of the nonwoven fabric 3 is interposed between the surface layer pad 5 and the core pad 1 to achieve connection between the two. In the bonding material 2, the inner surface 5b of the surface layer pad 5 is bonded and integrated to the upper surface side (one surface side) nonwoven fabric portion 32, and the upper surface 1a side of the core pad 1 enters the lower surface side (other surface side) nonwoven fabric portion 31 and bonded and integrated. To do. Here, the “upper surface” on the upper surface side of the bonding material 2 in the present invention means the surface on the side where the occupant abuts, like the upper surface of the core pad 1, and the “lower surface” refers to the opposite surface. .

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

Specifically, the base layer 3A of the spunbonded nonwoven fabric layer and the outer layer 3B of the nonwoven fabric layer that is entangled mechanically with raising at least on the core pad 1 side of the base layer 3A 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, the parison 72 stays in the outer layer 3B by blow molding of the core pad 1, and does not easily advance into the base layer 3A.
The spunbond nonwoven fabric of the spunbond nonwoven fabric layer is a nonwoven fabric having a network structure in which resin chips are melted to form yarns as in ordinary spinning, and are deposited on a conveyor as they are to form a web, which are bonded in a sheet form. The outer layer 3B having the raising of the nonwoven fabric layer that is mechanically entangled is bonded to the base layer 3A of the spunbond nonwoven fabric layer. The formation of the mechanically entangled nonwoven fabric is performed by a needle punch, a fluid punch, or the like. In the method using the 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, the outer layer 3B on the core pad 1 side penetrates the base layer 3A even if the outer layer 3B on the core pad 1 side penetrates the base layer 3A as shown in FIG. It doesn't matter what you have. In addition, you may use the three-layer nonwoven fabric (b of FIG. 4) in which the outer layer 3B is provided also on the surface layer pad 5 side as another aspect product.

More specifically, the nonwoven fabric 3 as the bonding material 2 is composed of a PET fiber base layer 3A and a polypropylene fiber outer layer 3B bonded at least to the core pad 1 side, and the core pad 1 is made of a polypropylene resin base. To do. With such a configuration, the parison 72 enters the outer layer 3 </ b> B of the nonwoven fabric with the raised material of the bonding material 2 by blow molding of the core pad 1, and the upper surface 1 a side of the core pad 1 enters the lower surface nonwoven fabric portion 31 of the nonwoven fabric 3. Join and integrate. And the outer layer 3B is made into a polypropylene fiber, and the core pad 1 with the bonding material 2 that further increases the bonding strength is obtained by adopting the polypropylene resin-based core pad 1 having excellent compatibility. The core pad 1 enters into the raised outer layer 3B and is melt-bonded.
Here, there is a possibility that the parison 72 of the core pad 1 in the blow molding may impregnate the outer layer 3B of the lower surface side nonwoven fabric portion 31 to the base layer 3A region. However, the parison 72 has a high viscosity, and the base layer 3A of the spunbond nonwoven fabric layer is more difficult to penetrate the parison 72 than the mechanically entangled outer layer 3B. Furthermore, the basis weight is large and the mesh structure is closed, so that the parison entry can be stopped before the base layer 3A. The parison 72 stays in the outer layer 3B when it is 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, even if the base layer 3A of PET fiber is used, the polypropylene resin parison 72 does not melt even if it enters the base layer 3A, and the network structure of the base layer 3A is easily maintained.

The bonding material 2 is also integrated with the surface layer 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 disposed on the base layer 3A side of the mesh structure opposite to the surface of the bonding material 2 joined and integrated with the core pad 1, in other words, on the upper surface side nonwoven fabric portion 32. Enter and join together. The foaming raw material g to be the surface layer pad 5 is impregnated into the joining material 2 during the foaming and joined and integrated. In the three-layer nonwoven fabric (B in FIG. 4) provided with the outer layer 3B on the surface layer pad 5 side, the surface layer pad may be disposed on the upper surface nonwoven fabric portion 32 on the outer layer 3B side on the surface layer pad 5 side, and further on the base layer 3A depending on the situation. The inner surface 5b side of 5 enters and is integrated.
As described above, the seat pad S of the present invention has the surface layer pad 5 and the core pad 1 intervening the bonding material 2 so that the bonding pad 2 is strongly and surely integrated and the weight reduction is realized by the core pad 1 of the blow molded body. The desired seat pad S is finished. Reference numeral 53 denotes a foam-molded portion of the surface layer pad 5 that fills the undercut portion 14, and reference numeral 59 denotes a hanging groove such as a vertical groove 591 and a horizontal groove 592.

(2) Manufacturing method of vehicle seat pad The seat pad S is manufactured by the following manufacturing method, for example. Using the bonding material 2, the blow mold 6 and the foam mold T, first, the bonding material 2 is set in the blow mold 6 and the core pad 1 is blow-molded to obtain the core pad 1 with the bonding material 2. Thereafter, the core pad 1 with the bonding material 2 is set in the foaming mold T (FIG. 12), and the inner surface 5b is bonded and integrated to the upper surface side (one surface side) nonwoven fabric portion 32 (exposed side) of the bonding material 2. This is a manufacturing method of a seat pad for foam-molding the foam surface layer pad 5 (FIG. 14).

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

  The blow mold 6 is a known apparatus for producing a blow-molded product. Between the pair of split molds 6A and 6B in which the outer shape of the core pad 1 as a blow-molded product is formed on the mold surface 61 and between the split molds 6A and 6B. And a die 71 for extruding the cylindrical parison 72 (FIG. 10). For example, a bonding material set pin 64 is provided on the split mold (one split mold) 6A for molding the core pad upper surface 1a side so that the sheet-like bonding material 2 can be set (a in FIG. 8). In addition, when using a molding felt (molded nonwoven fabric) bonding material 2 molded in advance in accordance with the mold surface shape of the split mold 6A, a recess 611 for setting the bonding material 2 is provided on the mold surface 61 of the split mold 6A. (B in FIG. 8). The joining material 2 is set between a pair of split molds 6A and 6B by attaching the joining material 2 to one split mold 6A with the upper surface side (one side) nonwoven fabric portion 32 facing the mold surface of one split mold 6A. Next, the parison 72 is pushed out from the die 71 between the split molds 6A and 6B in the mold open state (specifically, between the bonding material 2 and the other split mold 6B), and the parison 72 is inserted into the split molds 6A and 6B. Sandwiched between. Gas is blown into the sandwiched parison 72 with a blow pin (not shown), and the parison 72 is pressed against the mold surface 61 by the pressure to form a blow molding device that can be molded into the hollow body 73 for the core pad 1 with the bonding material 2 (FIG. 8). To FIG. 11). Reference numeral 623 denotes a protrusion for forming the set holding recess 123 of the core pad 1, reference numeral 624 denotes a protrusion for forming the strength reinforcing recess 124 of the core pad 1, and reference numeral 69 denotes a biting protrusion. .

  The foaming 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 mold cavity surface 91, a set holding convex portion 923 of the core pad 1 with the bonding material 2 and a strength reinforcing convex portion 924 of the core pad 1 are formed. When the core pad 1 with the bonding material 2 is set on the upper die cavity surface 91 and the die is closed as shown in FIG. 13 with the hinge hg as a fulcrum, the lower die cavity surface 81 having a large degree of dent and a convex portion 92 on a part thereof. The cavity C of the sheet pad S containing the core pad 1 with the bonding material 2 is formed with the substantially flat upper mold cavity surface 91. 12 to 14, the design surface side of the seat pad S is formed on the lower mold cavity surface 81, and the back surface side of the sheet pad S is formed on the upper mold cavity surface 91.

Using the bonding material 2, the blow mold 6 and the foam mold T, the seat pad S is manufactured as follows, for example.
First, under the mold open state, the bonding material 2 is set on the split mold 6A with the upper surface side (one side) nonwoven 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 (a in FIG. 8) attached to the split mold 6A, but 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. It may be hung. In the bonding material 2 of the present embodiment, the PET fiber base layer 3A of the spunbond nonwoven fabric layer is bonded to the polypropylene resin fiber outer layer 3B having the raised fabric of the nonwoven fabric layer mechanically entangled with at least the core pad 1 side of the base layer 3A. The two-layer nonwoven fabric (a in FIG. 4, FIG. 9). Further, the basis weight of the base layer 3A is larger than the basis weight of the outer layer 3B. The base layer 3A side nonwoven fabric upper surface (one surface) 3a of the bonding material 2 is directed to the mold surface 61 of the split mold 6A of the blow mold 6A that can be opened and closed so that the parison 72 can be sandwiched, and the outer layer side lower surface of the nonwoven fabric 3 The bonding material 2 made of the nonwoven fabric 3 is set in one split mold 6A with the (other surface) facing the other split mold 6B.
Although not shown, when the bonding material 2 is the three-layer nonwoven fabric of FIG. 4B, the lower surface of the nonwoven fabric on the outer layer 3B side is set toward the other split mold 6B. Further, when using a molded nonwoven fabric (molded felt) molded according to the mold surface shape of one split mold 6A, the upper surface 3a side of the nonwoven fabric 3 is used as a mold surface recess 611 of the blow mold 6 as shown in FIG. Set it in contact.

  Next, the parison 72 is lowered from the die 71 between the pair of split dies 6A and 6B under the mold open state (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 is inflated, and a part of the wall surface of the hollow body 73 is infiltrated into the joining material 2 to form a hollow body 73 with the joining material 2, which is finally formed into a hollow molded body. Blow molding of the core pad 1 with the bonding material 2 in which the bonding material 2 is bonded and integrated with the upper surface 1a of the core pad 1 is completed. The core pad upper surface 1a side enters the lower surface nonwoven fabric portion 31 of the bonding material 2 and is bonded and integrated to form the core pad 1 with the bonding material 2 (FIG. 11). In the blow molding, the set holding recess 123 is provided by the protrusion 623, and the strength reinforcing recess 124 is provided by the protrusion 624. 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, the burrs 1B in which a part of the burr is integrated with the hollow main body 1A. , The mounting portion 15 is formed. The core pad 1 is a blow molded product in which the flange portion 1B and the attachment portion 15 are integrated with the hollow main body 1A. Mold opening and demolding are performed, and burrs other than the flange portion 1B and the attachment portion 15 are removed to obtain the core pad 1 with the bonding material 2 as shown in FIG.

  Then, the nonwoven fabric upper surface 3a of the bonding material 2 is exposed so as to face the lower mold 8, and the core pad 1 with the bonding material 2 is set on the upper mold cavity surface 91 of the foaming mold T (FIG. 12). Since the seat pad S is formed upside down in the foam molding die T in which the core pad lower surface 1b is brought into contact with the upper die cavity surface 91, the nonwoven fabric upper surface 3a is set on the upper die 9 so as to face the lower die 8. The The convex portion 923 of the upper mold 9 is inserted into the set holding recess 123, and the core pad 1 with the bonding material 2 is held in the upper mold 9.

Thereafter, a soft polyurethane foam raw material is injected onto the lower mold cavity surface 81 and the mold is closed. A predetermined amount of the foam material g for forming the seat pad is injected onto the lower mold cavity surface 81 using the injection hose NL or the like while the mold is open.
Then, the upper die 9 is actuated to close the die (FIG. 13). By closing the mold between the upper mold 9 and the lower mold 8, a sheet pad cavity C in which the core pad 1 with the bonding material 2 is insert-set is formed.

  After closing the mold, the main process moves to foam molding. A flexible polyurethane foam that forms a contact surface portion 51 on the design surface 5a side and impregnates the upper surface nonwoven fabric portion 32 of the joining material 2 with the foaming raw material g so that the inner surface 5b side enters the upper surface nonwoven fabric portion 32 and is joined and integrated. The body surface pad 5 is foam-molded (FIG. 14). The surface layer pad 5 that embeds the flange portion 1B and covers the portion of the undercut portion 14 formed on the side wall 13 near the lower surface of the core pad 1 from the core pad upper surface 1a side and reaches the core pad lower surface 1b is foam-molded. The core pad 1 is embedded with the surface layer pad 5, but the lower surface 1 b is left as the exposed surface 19.

Here, in this embodiment, the PET fiber base layer 3A of the spunbond nonwoven fabric layer is bonded to the polypropylene fiber outer layer 3B of the nonwoven fabric layer that has brushed at least on the core pad 1 side of the base layer 3A and is mechanically entangled. Adopted bonding material 2 is employed. 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 upper surface nonwoven fabric portion 32 of the bonding material 2 maintains the network structure of the nonwoven fabric as described above. At the initial stage of foam molding after mold closing, foaming of the foam raw material g proceeds from the state of FIG. 13 and the upper surface thereof rises. Eventually, it reaches the upper surface of the bonding material 2. The parison 72 does not enter the base layer 3A on the upper surface side of the bonding material 2 by the previous blow molding, and a network-structured nonwoven fabric is maintained. The foaming raw material g enters into between the fibers of the nonwoven fabric. A part of the foam raw material g penetrates into the space between the fibers of the upper surface side nonwoven fabric portion 32 of the bonding material 2 and is eventually cured. The foamed raw material g soaked in the upper surface side nonwoven fabric portion 32 is entangled with the nonwoven fabric portion and cured to form a flexible polyurethane foamed bonded portion. In FIG. 4 (a), the soft polyurethane foam molding bonded 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 progresses in foaming, burying the flange portion 1 </ b> B protruding from the core pad side wall 13, the upper surface rises, and further covers the undercut portion 14 and reaches the upper mold cavity surface 91.

  In this manner, the cavity C is filled with the foam of the foaming raw material g, and the foam molding of the surface layer pad 5 made of the soft polyurethane foam is completed, in which the inner surface 5b side enters the upper surface side of the bonding material 2 and is joined and integrated (FIG. 14). . An attachment portion 15 for connecting and fixing to the vehicle body integrally formed by blow molding on the side wall 13 of the core pad 1 protrudes to the outside of the surface layer pad 5 (FIGS. 1 and 6). When foam molding is completed and demolded, the weight reduction is realized 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 are bonded via the bonding material 2. A desired seat pad S with increased height is completed. Reference numeral 84 denotes a lateral groove forming portion, and reference numerals 89 and 99 denote mold matching surfaces.

(3) Effect According to the vehicle seat pad configured as described above and the manufacturing method thereof, the seat pad S is formed into a hollow molded body having gas inside, and the lightweight core pad 1 occupies it. Can be realized.
When the bonding material 2 made of the nonwoven fabric 3 is interposed between the surface layer pad 5 and the core pad 1, the bonding material 2 is connected to connect the surface layer pad 5 and the core pad 1. Since the core pad 1 is blow-molded and enters the lower surface side nonwoven fabric portion 31 of the bonding material 2 to be bonded and integrated, the bonding material 2 is strongly bonded and integrated with the core pad 1 unlike fixing such as simple bonding. .
On the other hand, on the upper surface side of the bonding material 2, the inner surface 5 b side of the surface layer pad 5 can enter the upper surface side nonwoven fabric portion 32 so as to be bonded and integrated. Unlike fixing, the bonding material 2 is strongly bonded and integrated with the core pad 1. Even in the case of a sheet pad S having a core pad 1 in the lower half and an exposed surface 19 on the core pad lower surface 1b in a large product, the surface pad 5 is difficult to peel off from the core pad 1, and the surface pad 5 and the bonding material The joint integrity of 2 is improved. The connection between the surface layer pad 5 and the core pad 1 is strengthened through the bonding material 2.

Then, the bonding material 2 is composed of the nonwoven fabric 3, and the base layer 3A of the spunbond nonwoven fabric layer is bonded to the outer layer 3B of the nonwoven fabric layer that has brushed at least on the core pad 1 side of the base layer 3A and is mechanically entangled. When laminated, the core pad 1 can be blow-molded so that the parison 72 can smoothly penetrate into the nonwoven fabric layer having raised hairs and mechanically entangled. Since the spunbond nonwoven fabric layer has a high penetration resistance, the parison 72 stays on the lower surface nonwoven fabric portion 31 of the bonding material 2 and is joined and integrated. The nonwoven fabric upper surface 3a side remains as it is. If the basis weight of the base layer 3A is larger than the basis weight of the outer layer 3B, the infiltration resistance of the spunbond nonwoven fabric layer is further increased. Therefore, even after the core pad 1 is blow molded, the network structure on the nonwoven fabric upper surface 3a side is the same as before the blow molding. It can be left in shape. Thus, in the subsequent foam molding of the surface layer pad 5, the inner surface 5 b side of the surface layer pad 5 enters the nonwoven fabric upper surface 3 a side, and the bonding force between the surface layer pad 5 and the bonding material 2 is increased unlike simple bonding.
On the other hand, when the core pad 1 is made of a polypropylene resin base, the nonwoven fabric 3 is formed by bonding and laminating a PET fiber base layer 3A and at least the core pad 1 side with a polypropylene fiber outer layer 3B. It becomes the core pad 1 with the joining material 2 which increases. This is because the parison 72 penetrates into the compatible outer layer 3B and is melt-bonded with the outer layer 3B when the core pad 1 is blow-molded.
More specifically, when the core pad 1 is a blow-molded product in which the flange portion 1B projecting outward from the side wall 13 of the hollow body 1A is integrally formed, and the flange portion 1B is embedded in the surface layer pad 5, the flange portion 1B. Regulates the peeling of the surface layer pad 5 from the core pad 1, so that the integration of the core pad 1 and the surface layer pad 5 becomes a stone.

In order to attach the seat pad S to the vehicle body, a separate attachment portion 15 is required for the seat pad S. However, by blow molding, attachment for fixing the connection to the vehicle body appearing outside the surface layer pad 5 on the core pad 1 If 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. However, the present invention does not require assembling, and there is a risk of weight increase due to the metal part. Absent. The core pad 1 of a blow-molded product having a certain outer dimension is different from the bead foam molded body in which the dimensional accuracy cannot be increased, and the mounting portion 15 has a high mounting position accuracy.
In addition, the flange portion 1B and the attachment portion 15 can be integrally formed with the hollow main body 1A, the flange portion 1B, and the attachment portion 15 by processing a 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 no inventory management is required. It can be handled at low cost while maintaining productivity, which is extremely beneficial.

More specifically, an undercut portion 14 is formed on the lower surface side wall 13 of the core pad 1, and the surface layer 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. And the undercut part 14 is also useful for preventing peeling of the surface layer pad 5 from the core pad 1.
Further, if the core pad 1 is provided with the set holding recess 123, it is easy to set the surface layer pad 5 on the foam molding die T during foam molding. Further, if the core pad 1 is provided with the strength reinforcing recess 124, the hollow main body 1A is in the large core pad 1 and the required strength can be easily secured.
As described above, the vehicle seat pad S and its manufacturing method achieve weight reduction by using the core pad 1 of the blow molded product made of a hollow molded body whose inside is only gas, and the core pad 1 and the surface layer pad 5. In addition, it is possible to reduce the number of parts by integrally molding the mounting portion 15 and the mounting portion 15 and so on.

  The present invention is not limited to those shown in the above-described embodiment, and various modifications can be made within the scope of the present invention depending on the purpose and application. The shape, size, number, material, and the like of the core pad 1, the bonding material 2, the surface layer pad 5, the blow mold 6, and the foam mold T 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 backrest. The collar portion 1 </ b> B may not be on the entire circumference of the core pad 1. It may be provided partially on the outer periphery of the core pad 1.

DESCRIPTION OF SYMBOLS 1 Core pad 1A Hollow main body 1B Ridge part 14 Undercut part 15 Attachment part 2 Bonding material 3 Nonwoven fabric 3a Nonwoven fabric upper surface (one surface of nonwoven fabric)
32 Upper side nonwoven fabric part (one side nonwoven fabric part)
5 Surface layer pad 5a Design surface 5b Inner surface 51 Contact surface portion of seated occupant 6 Blow molding die 61 Mold surface (split mold surface)
8 Lower mold (foam mold lower mold)
81 Lower mold cavity surface g Foaming raw material S Seat pad T Foaming mold

Claims (13)

A vehicle seat pad in which at least a contact surface portion on a side where an occupant abuts is formed of a soft polyurethane foam molded article,
A core pad of a blow molded product formed in a hollow molded body of thermoplastic plastic;
A soft polyurethane foam molded body, the contact surface portion is formed on the design surface side, and the upper surface of the core pad is formed to follow the inner surface, and a surface layer pad covering the upper surface of the core pad;
It is interposed between the surface layer pad and the core pad, and is made of a nonwoven fabric. The inner surface side of the surface layer pad enters and is integrated into one nonwoven fabric portion, and the upper surface side of the core pad enters and joins the other nonwoven fabric portion. A vehicular seat pad comprising: an integrated bonding material. The non-woven fabric is laminated by bonding a base layer of a spunbond non-woven fabric layer and an outer layer of a non-woven fabric layer that has brushed at least on the core pad side of the base layer and is mechanically entangled, and more than the basis weight of the outer layer The vehicle seat pad according to claim 2, wherein the basis weight of the base layer is large. 3. The vehicle according to claim 1, wherein the core pad is made of a polypropylene resin base, and the nonwoven fabric is laminated by bonding a base layer of PET fiber and an outer layer of polypropylene fiber at least on the core pad side. Seat pad. 4. A hollow portion having an exposed surface on a lower surface of the hollow body related to the core pad, wherein the exposed surface is gently and uniformly formed, and a recess partially recessed on the upper surface side is formed. The vehicle seat pad according to any one of the above. 5. The undercut portion is formed on the side wall near the lower surface of the core pad, and the surface layer pad covers the undercut portion from the upper surface side of the core pad and reaches the lower surface of the core pad. The vehicle seat pad according to claim 1. The core pad is a blow-molded product in which a flange portion projecting outward from the side wall of the hollow body is integrally formed, and the flange portion is embedded in the surface layer pad. The vehicle seat pad as described. The vehicle seat pad according to claim 6, wherein the core pad is provided with an attachment portion for connecting and fixing to a vehicle body such that a part of the collar portion protrudes outside the surface layer pad. A vehicle seat pad manufacturing method in which at least a contact surface portion on the side where an occupant abuts is formed of a soft polyurethane foam molded article,
A blow mold for molding a core pad. One surface of the mold pad for molding the upper surface side of the core pad is directed to one surface side of a sheet-shaped bonding material made of nonwoven fabric, and the sheet-shaped bonding material is placed between the split molds. Then, the other side nonwoven fabric portion of the bonding material is blow-molded with the bonding material core pad which is bonded and integrated by inserting the upper surface side of the core pad formed in the hollow molded body, One side of the nonwoven fabric related to the sheet-like bonding material is exposed so as to face the lower mold, and the core pad with the bonding material is set on the upper mold cavity surface of the foam mold, and then the flexible polyurethane is formed on the lower mold cavity surface. The foam raw material is injected and the mold is closed. Thereafter, the contact surface portion is formed on the design surface side, and the surface layer pad of the flexible polyurethane foam is joined and integrated into the one side nonwoven fabric portion of the bonding material. Method for producing a vehicle seat pad, characterized in that foamed molded. The vehicle according to claim 8, wherein the nonwoven fabric is laminated by bonding a base layer of a spunbond nonwoven fabric layer and an outer layer of the nonwoven fabric layer having brushed at least on the core pad side of the base layer and mechanically entangled. Method for manufacturing a seat pad for an automobile. 10. The vehicle according to claim 8, wherein the core pad is made of a polypropylene resin base, and the nonwoven fabric is laminated by bonding a base layer of PET fiber and an outer layer of polypropylene fiber at least on the core pad side. A manufacturing method of a seat pad. 11. An undercut portion is formed on a side wall near the lower surface of the core pad, and the surface layer pad reaching the lower surface of the core pad by covering the portion of the undercut portion from the upper surface side of the core pad is foam-molded. The manufacturing method of the vehicle seat pad of any one of these. 12. The flange according to claim 8, wherein a flange projecting outward from the side wall of the core pad is integrally formed by blow molding of the core pad, and then the flange is embedded by foam molding of the surface layer pad. The manufacturing method of the vehicle seat pad of description. 13. An attachment portion for fixing a connection to a vehicle body is integrally formed on the side wall of the core pad by the blow molding, and then the attachment portion protrudes to the outside of the surface layer pad by foam molding of the surface layer pad. The manufacturing method of the vehicle seat pad of any one of these.

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