Vehicle cushion pad and manufacturing method thereof

Abstract

To provide a cushion pad for a vehicle, which employs a core pad of foamed bead molding useful for weight reduction, exposes its back surface, and covers the side surface of the core pad up to the outer peripheral edge of the back surface with the side part of a surface pad, while preventing the foaming raw material from getting around to the back surface of the core pad in foam molding of the surface pad, thereby reducing the labor burden on workers and contributing to improving productivity, and a method for manufacturing the same. [Solution] A vehicle cushion pad in which at least the receiving surface portion on the side where the occupant comes into contact is formed with a surface pad of soft polyurethane foam molding, comprises a core pad 2 made of bead foam molding, with a flexible thin plate portion 26 formed upright along the outer peripheral edge 21 of the back surface near the outer peripheral edge of the back surface, and a surface pad in which the core pad 2 is an insert product with its back surface 2b exposed, and side portions 32 cover the side of the core pad 2 up to the outer peripheral edge 21 of the back surface, embedding and integrating it.

Description

[Technical field]

[0001] The present invention relates to a vehicle cushion pad constituting a vehicle seat and a manufacturing method thereof. [Background technology]

[0002] In seats installed in vehicles such as automobiles, the cushion pads constituting the seating area have been made exclusively of soft polyurethane foam to provide comfortable cushioning. However, in recent years, for the purpose of weight reduction, etc., inventions have been proposed in which the lower layer of the cushion pad is made of a bead foam molded product of polystyrene foam or polyolefin foam (for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5277912 [Patent Document 2] Japanese Patent Application Publication No. 9-70330 [Patent Document 3] Japanese Utility Model Application Publication No. 58-175756 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0004] Here, in Patent Documents 1 and 2, in which a core pad of bead foam molding exists in the lower layer, the side surface is exposed and is not covered by the soft polyurethane foam layer, so that when an occupant touches it, there is a problem of poor cushioning and poor touch. On the other hand, as in Patent Document 3, if the polyolefin foam layer (the "core pad" in the present invention) is only exposed on the back surface, and the side portion of the polyurethane foam layer (the "surface pad" in the present invention) can cover the side surface of the core pad up to the outer periphery of the back surface, the problem of poor cushioning and poor touch can be solved. However, when the surface pad is configured to cover the side surface of the core pad up to the outer periphery of the back surface as in Patent Document 3, the foaming raw material tends to go around to the back surface of the core pad and penetrate toward the center of the back surface during foam molding of the surface pad. The bead foam molding of the core pad 2 has poor cushioning and sealing properties, and further tends to shrink during foam molding, which makes it even easier for the foaming raw material to penetrate into the back surface 2b of the core pad (FIG. 11). The infiltrated foaming material forms a polyurethane film k on the back surface 2b of the core pad, which causes a problem of rubbing noise after the cushion pad 1 is mounted on the vehicle. Therefore, in a post-process after foaming, a nonwoven fabric or the like must be attached to cover the soft polyurethane film k on the back surface 2b of the core pad to prevent rubbing noise, which increases the labor burden.

[0005] The present invention solves the above-mentioned problems and aims to provide a vehicle cushion pad and a manufacturing method thereof which employs a core pad made of expanded beads, which is useful for reducing weight, has an exposed back surface, and has the sides of the core pad covered up to the outer peripheral edge of the back surface with the sides of the surface pad, while preventing the foaming raw material from leaking around to the back surface of the core pad during foam molding of the surface pad, thereby reducing the labor burden on workers and contributing to improved productivity. [Means for solving the problem]

[0006] In order to achieve the above object, the gist of the invention is a method for manufacturing a cushion pad for a vehicle, in which at least the receiving surface portion on the side where an occupant comes into contact is formed of a surface pad of a soft polyurethane foam molded body, the method comprising the steps of: using a core pad of a bead foam molded body as an insert product, the core pad having a thin plate portion formed upright in a low portion on the back surface outer periphery side with a gap interposed between a wall surface on the back surface outer periphery side from a low portion on the outer periphery side to a high portion that is raised one step up near the outer periphery of the back surface; providing a recess in a portion corresponding to the high portion including the thin plate portion in an upper mold in which the core pad is set; The method for manufacturing a vehicle cushion pad is characterized in that the depression has a side wall with an inclined surface approaching the center of the depression from the entrance toward the bottom surface, the thin plate portion slides along the inclined surface, the vertical surface of the thin plate portion on the back outer periphery side is pressed against the side wall, the thin plate portion is inserted into the depression together with the high portion, the core pad is set in the upper mold, soft polyurethane foaming raw material is then injected into the cavity surface of the lower mold and the mold is closed, and then the side portion covers the side surface of the core pad up to the back outer periphery of the core pad, and the embedded and integrated surface pad is foam-molded. The manufacturing method for a vehicle cushion pad according to the invention is characterized in that the thickness of the thin plate portion becomes smaller from the base end portion connected to the low portion toward the tip portion, and the vertical surface is inclined toward the wall surface side of the high portion toward the tip portion. The method for manufacturing a vehicle cushion pad according to the present invention is characterized in that both the wall surface and the vertical surface of the thin plate portion are provided along the outer peripheral edge of the back surface of the core pad, and the vertical surface is set to have a longer length along the outer peripheral edge of the back surface than the wall surface. The method for manufacturing a vehicle cushion pad according to the present invention is characterized in that the thin plate portion is separated from the high portion by the gap running in the vehicle width direction, and is provided along the outer peripheral edge in the vehicle width direction of the back surface of the vehicle rear side.The gist of the invention is a vehicle cushion pad having at least a receiving surface portion on the side where an occupant comes into contact formed of a surface layer pad of a soft polyurethane foam molded body, characterized in that the vehicle cushion pad comprises: a core pad made of a bead foam molded body, in which a thin plate portion having a surface facing the wall surface is formed on the back surface outer peripheral edge side with a gap from a wall surface on the back surface outer peripheral edge side from a low part on the outer peripheral edge side to a high part that is raised one step up near the outer peripheral edge of the back surface, and a surface layer pad in which the core pad is an insert product with its back surface exposed, and the side portion of the core pad is embedded and integrated by covering the side surface of the core pad up to the back surface outer peripheral edge. The vehicle cushion pad according to the invention is characterized in that the plate thickness of the thin plate portion becomes smaller from the base end portion connected to the low part toward the tip portion, and the upright surface is inclined toward the wall surface side of the high part toward the tip portion. The vehicle cushion pad of the invention is characterized in that both the wall surface and the vertical surface of the thin plate portion are arranged along the outer peripheral edge of the back surface of the core pad, and the vertical surface is set to have a longer length along the outer peripheral edge of the back surface than the wall surface. Effect of the Invention

[0007] The vehicle cushion pad and its manufacturing method of the present invention is a cushion pad in which a core pad of a bead foam molding is embedded and integrated with a surface pad, which prevents the foaming raw material from penetrating into the back surface of the core pad during surface pad molding and does not require post-processing such as application of tape, thereby providing excellent effects in reducing labor and improving productivity. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view of the cushion pad as viewed from the back surface side, in one embodiment of the cushion pad and the manufacturing method thereof of the present invention. [Diagram 2] 2 is a perspective view of the cushion pad of FIG. 1 as viewed from the front surface side. FIG. [Diagram 3] A cross-sectional view showing a core pad set in an upper mold when the mold is open. [Figure 4] This is a partially enlarged view just before the core pad is set on the upper mold. [Diagram 5]FIG. 5 is a partially enlarged view showing the state of FIG. 4 after the core pad has been set in the upper mold. [Figure 6] FIG. 11 is a cross-sectional view showing the foaming raw material being injected into the lower mold in an open state. [Figure 7] FIG. 7 is a cross-sectional view showing the state after the mold is closed from the state shown in FIG. 6. [Figure 8] 1 is a cross-sectional view of a surface pad integral with a core pad, which has been foam-molded. [Figure 9] FIG. 2 is a perspective view of a cushion pad according to another embodiment, which is an alternative to the cushion pad shown in FIG. 1. [Figure 10] FIG. 2 is a perspective view of a cushion pad according to another embodiment, which is an alternative to the cushion pad shown in FIG. 1. [Figure 11] FIG. 1 is an explanatory perspective view of a cushion pad according to a related art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a vehicle cushion pad (hereinafter, simply referred to as a "cushion pad") according to the present invention and a method for manufacturing the same will be described in detail. (1) Method for manufacturing a cushion pad Figs. 1 to 10 show one embodiment of the cushion pad and its manufacturing method according to the present invention, which are applied to a cushion pad for a rear seat of a vehicle. Fig. 1 is a perspective view of the cushion pad as seen from the back side, and Fig. 2 is a perspective view of the cushion pad as seen from the front side. Fig. 3 is a cross-sectional view of the core pad set in the upper mold in the mold open state, Fig. 4 is a partially enlarged view immediately before the core pad is set in the upper mold, Fig. 5 is a partially enlarged view of the state of Fig. 4 after the core pad has been set in the upper mold, Fig. 6 is a cross-sectional view of the foaming raw material being injected into the lower mold in the mold open state, Fig. 7 is a cross-sectional view of the mold closed from the state of Fig. 6, Fig. 8 is a cross-sectional view of the surface pad integrated with the core pad foam-molded, and Figs. 9 and 10 are perspective views of a cushion pad of another embodiment replacing Fig. 1. In Fig. 1, which shows the back side of the cushion pad, the upper left side of the sheet corresponds to the vehicle front of the cushion pad, and in Fig. 2, the cushion pad is in the state in which it is installed on the vehicle, with the upper right side corresponding to the vehicle front. In each figure, the essential parts of the invention are emphasized in order to make the drawings easier to understand, and parts that are not directly related to the present invention are simplified or omitted.

[0010] (1) Manufacturing method of vehicle cushion pad The manufacturing method of the vehicle cushion pad is a manufacturing method in which at least the receiving surface portion 31 on the side where the occupant comes into contact is formed from a soft polyurethane foam molded body, and the surface pad 3 of the soft polyurethane foam molded body is foam molded to bond its inner surface 3b side to a lightweight core pad 2 (Fig. 8). The side of the cushion pad 1 where the occupant comes into contact is the design surface. Here, this is applied to a cushion pad 1 for a three-seater seat in the rear seat of a vehicle as shown in Fig. 2. Prior to foam molding of the surface pad 3, the core pad 2 and foam molding mold 7 are prepared.

[0011] The core pad 2 is a bead foam molded body, and is a core member in which a high part 25 is provided toward the center of the back surface 2b, rising from a low part 24 on the outer periphery side near the outer periphery 21. A slice-shaped thin plate part 26 having an opposing surface of a size matching the wall surface 251 is formed upright on the low part 24 on the back surface outer periphery 21 side, which is spaced apart from the wall surface 251 on the back surface outer periphery 21 side leading to the high part 25. The thin plate part 26 is integrally formed by foam molding of the core pad 2, and its thickness is reduced from the plate thickness t1 to the plate thickness t2 from the base end part connected to the low part 24 toward the tip part. In the present invention, the side relatively lower than the high part 25 is called the low part 24, and here, the thin plate parts 26 are formed at three places on the low part 24 on the outer periphery 21 side beside the high part 25 (FIG. 1). A small raised portion 28 is formed on the back surface 2b of the core pad 2 on the back surface of the seat of the main portion 3A in accordance with the three-seater seat, and a thin plate portion 26 is provided on each of the outsides of the raised portions 28 in the vehicle width direction in the vehicle travel direction. A low portion 24 is provided from the back surface outer periphery 21 toward the front side of the vehicle at the center of the rear side of the vehicle, and a step wall 271 is climbed from the low portion 24 to form a step 27 that is one step higher, and the center of the step 27 in the vehicle width direction protrudes toward the rear of the vehicle. The protruding step 27 is made into a high portion 25, and a thin plate portion 26 is provided on the low surface 24a related to the low portion 24 on the back surface outer periphery 21 side with a gap ε interposed between the wall surface 251 on the back surface outer periphery 21 side. The core pad 2 of this embodiment is a bead foam molded product of expanded polypropylene (EPP), and its apparent density is smaller than the apparent density of the surface pad 3 made of a soft polyurethane foam molded product. Reference numeral 22 denotes a plurality of grooves for engaging the skin end provided at a predetermined interval along the rear outer peripheral edge 21 near the rear outer peripheral edge 21.

[0012] Here, the "reverse side" of the core pad reverse side 2b in the present invention refers to the "underside" of the paper, the surface on the lower side, that is, the surface facing the vehicle floor, in terms of the cushion pad 1 in Figure 2 in a state of being installed in a vehicle. Also, the "bead foam molded product" refers to a foam molded product obtained by the so-called bead foaming method, which is a block-shaped foam molded product formed by pre-foaming the raw material beads and then foaming in a mold. The bead foaming method is also simply called the bead method. The bead foam molded product is preferably a molded product made of polystyrene foam, polypropylene foam, polyethylene foam, or at least one of these. It is a bead foam molded product with air bubbles sealed inside, and most of the volume is gas, making it lightweight, airtight, shape-retaining, and suitable retention. This is advantageous for the core pad 2, which needs to maintain its shape. By increasing the expansion ratio, the apparent density can be easily made smaller than that of the soft polyurethane foam molding.

[0013] The foam molding die 7 is a split die as shown in FIG. 6, and a lower die 8 and an upper die 9 are connected so as to be able to open and close. When the die is closed as shown in FIG. 7, the cavity C of the cushion pad 1 is formed by the lower die cavity surface 81 which forms the receiving surface portion 31 which is recessed as a whole into a bowl shape and becomes the design surface 3a, and the upper die cavity surface 91 which matches the back surface 2b of the core pad 2. The upper die 9 is provided with a recess 93 at a corresponding portion of the high part 25 including the thin plate part 26 by setting the core pad 2. In terms of the cavity surface 91 of the upper die 9 which corresponds to the VIII-VIII line arrow view of FIG. 1, as shown in FIG. 4 and FIG. 8, the cavity surface 911 with which the low part 24 abuts passes through the side wall 931 of the recess 93 and reaches the bottom surface 935 of the recess 93 with which the high part 25 abuts by setting the core pad 2 on the upper die 9. 4, which appears in the view taken along the line VIII-VIII, has a bottom surface 935 that extends directly to the right of the drawing as the upper die cavity surface 91. The side wall 931 is formed as an inclined surface approaching the center of the recess 93 from the entrance 930 of the recess 93 toward the bottom surface 935, and when the core pad 2 is set in the upper die 9, the vertical surface 261 on the back surface outer peripheral edge 21 side of the thin plate portion 26 is pressed against the inclined surface to facilitate sealing. The main side wall 931 shown in FIGS. 3 to 8 is an inclined surface that extends from the entrance 930 of the recess 93 on the vehicle rear side toward the bottom surface 935 of the recess 93, which is one step deeper toward the vehicle front side, as shown in the drawings. When the core pad 2 is set in the upper mold 9, the thin plate portion 26 in FIG. 4, which is in the state immediately before the core pad 2 is set, hits the inclined side wall 931, and then deforms as shown in FIG. 5, and the vertical surface 261 on the back surface outer peripheral edge 21 side is pressed against the side wall 931. Reference numeral 912 denotes a cavity surface that forms the side back surface 323 of the surface layer pad 3, and after the core pad 2 is set in the upper mold 9, it is located outside the back surface outer peripheral edge 21 of the core pad 2 when the mold is closed. Reference numeral 86 denotes a raised portion for a hanging groove, and reference numerals 89 and 99 denote mold mating surfaces. The foam molding mold 7 in FIG. 3 to FIG. 6 has a mold structure that produces the surface layer pad 3 that is integrated with the core pad 2 as the cushion pad, in a state that is upside down from the cushion pad 1 in FIG. 2 that is installed on the vehicle.

[0014] Using the foam molding die 7 and the core pad 2, the cushion pad 1 is manufactured, for example, as follows. First, prior to manufacture, the groove opening of the locking groove 22 is sealed with tape, and the core pad 2 is set in the upper die 9 with the foam molding die 7 in an open state (FIG. 3). When the core pad 2 is attached and set in the upper die 9, the tip portion 26a of the thin plate portion 26 first hits the side wall 931 formed on the inclined surface of the recess 93 (FIG. 4). In this state, the core pad 2 is pressed upward toward the upper die 9. Then, the thin plate portion 26 slides along the inclined surface of the side wall 931, undergoes deformation to fit the inclined surface, and fits into the recess 93 together with the high portion 25, completing the setting of the core pad 2 in the upper die 9 (FIGS. 5 and 6). Here, the vertical surface 261 of the thin plate portion 26 is inclined toward the wall surface 251 of the high part 25 toward the tip portion 26a as shown in FIG. 4, so that it is easy to deform by approaching the inclined surface of the side wall 931. At least a part of the vertical surface 261 of the thin plate portion 26 adheres to the side wall 931 in a deformed state pressed against the side wall 931 as shown in FIG. 5. Even if the core pad 2 is made of a bead foam molded body, the slice-shaped thin plate portion 26 has the deformable flexibility shown in FIG. 4, and the thin plate portion 26 is made thinner from the base end portion toward the tip portion, so that the thin plate portion 26 can smoothly respond to the deformation shown in FIG. 4. Note that FIGS. 3 to 6 show the thin plate portion 26 provided at the center of the rear side of the vehicle as shown in the arrow view of line VIII-VIII in FIG. 1 and the setting pattern in the recess 93 of the high part 25 through the gap ε, but the same is true for the thin plate portion 26 formed on the left and right outer sides in the vehicle width direction of the raised part 28 with respect to the vehicle traveling direction. The thin plate portion 26 located on the left and right outer sides of the raised portion 28 in the vehicle width direction also slides along the inclined surface of the side wall 931 and deforms into a bow shape, pressing the vertical surface 261 on the back outer edge 21 side against the inclined side wall 931 of the recess 93 not shown. Almost simultaneously with the thin plate portion 26 and the high portion 25 provided in the center of the rear side of the vehicle, the thin plate portion 26 is inserted into the recess 93 together with the high portion 25, and the core pad 2 is set in the upper mold 9.

[0015] Next, soft polyurethane foaming raw material g (hereinafter, simply referred to as "foaming raw material") for forming the surface pad 3 is injected into the lower mold cavity surface 81, and the mold is closed. A predetermined amount of foaming raw material g is injected into the bowl-shaped concave lower mold cavity surface 81 using an injection nozzle NL or the like (FIG. 6). Next, the upper mold 9 is operated and the mold is closed (FIG. 7). By closing the upper mold 9 and the lower mold 8, a cavity C for the cushion pad 1 in which the core pad 2 is insert-set is formed. In this mold closing, the hanging groove protrusion 86 may be brought into contact with the surface 2a of the core pad 2, and the core pad 2 may be supported from below and held in the cavity C. Note that, after the core pad 2 is set on the upper mold 9, the foaming raw material g is injected and then the mold is closed, but it is also possible to set the core pad 2 on the upper mold 9, close the mold, and then inject the foaming raw material g.

[0016] After the mold is closed, the process moves to the foaming of the surface pad 3, which is the main process. The mold closed state shown in FIG. 7 is maintained for a predetermined time, and the surface pad 3 is foamed and molded from a soft polyurethane foam molded body with the core pad 2 embedded and integrated therein, having a receiving surface portion 31 on the design surface 3a side against which a seated occupant abuts. In the initial stage of foaming, the foaming raw material g advances in foaming. After filling the cavity C of the receiving surface portion 31, the foaming raw material g rises and reaches the upper mold cavity surface 91. During this rise, the foaming raw material g tries to go around and infiltrate the back surface 2b of the core pad, but as described above, the vertical surface 261 of the thin plate portion 26 is pressed against the side wall 931 of the recess 93 to seal it, so that the progress of the foaming raw material g stops there. With the foaming raw material g prevented from entering the back surface 2b of the core pad beyond the thin plate portion 26, the surface pad 3 is foamed and molded to fill up to the back surface 323 of the side portion 32 as shown in FIG. 8. The surface pad 3 with the core pad 2 embedded therein is foam-molded. The core pad 2 may shrink during manufacturing, but even if it shrinks, the side wall 931 that the tip portion 26a of the thin plate portion 26 abuts against when the core pad 2 is set in the upper mold 9 is an inclined surface, so that even if the core pad 2 shrinks in the lateral direction of the paper in FIG. 4, there is a tolerance range for the inclined side wall 931 that receives the tip portion 26a of the thin plate portion. Therefore, even if some dimensional deviation occurs due to the shrinkage of the core pad 2, the vertical surface 261 of the thin plate portion 26 can be easily pressed against the side wall 931, and the thin plate portion 26 can be deformed and adhered to the side wall 931 to be sealed. The pressing of the thin plate portion 26 against the side wall 931 may be assisted by the support of the hanging groove protuberance 86 described above.

[0017] 7 is maintained for a predetermined time, exposing the back surface 2b of the core pad 2, and covering the side surface 23 of the core pad 2 with the side portion 32 from the core pad front surface 2a side to the back surface outer peripheral edge 21, and foaming the surface pad 3 with the core pad 2 embedded and integrated. When foaming is completed and the mold is removed, the receiving surface portion 31 is formed, and the desired cushion pad 1 is obtained without any burrs of the foaming raw material g because the thin plate portion 26 prevented the foaming raw material g from penetrating into the center of the core pad back surface 2b during foaming. The tape that covered the locking groove 22 is removed after the mold is removed.

[0018] In this embodiment, the entire periphery of the core pad side surface 23 is covered with the side portion 32 as shown in Fig. 2, but the portion that is not particularly touched by the occupant may be omitted. Also, as shown in Figs. 1 to 8, the size of the wall surface 251 on the back outer peripheral edge 21 side of the high part 25 and the size of the opposing surface of the thin plate part 26 opposing the wall surface are made approximately the same, but for example, as shown in Fig. 9, the vertical surface 261 of the thin plate part 26 can be made larger than the wall surface 251. As in Fig. 1, the high part 25 and the thin plate part 26 arranged in the center of the vehicle rear side in Fig. 9 have both the wall surface 251 of the high part 25 and the vertical surface 261 of the thin plate part 26 provided along the back outer peripheral edge 21 of the core pad 2, but the vertical surface 261 is set to have a longer length along the back outer peripheral edge 21 than the wall surface 251. The vehicle width direction length L6 of the vertical surface 261 is longer than the vehicle width direction length L5 of the wall surface 251. This thin plate portion 26 is more preferable because it widens the defensive area in the vehicle width direction that blocks the infiltration of the foaming raw material g from the outer peripheral edge 21 of the core pad back surface on the vehicle rear side to the center of the core pad back surface 2b. Also, it is possible to use a core pad 2 as shown in Fig. 10, in which the locking groove 22 is provided in the high part 25 on the vehicle rear side and the thin plate portion 26 with a length in the vehicle width direction that covers the locking groove is formed upright in the low part 24. In foam molding of the surface pad 3 in which the core pad 2 is embedded and integrated, the thin plate portion 26 prevents the infiltration of the foaming raw material g into the locking groove 22 in addition to preventing the infiltration of the foaming raw material g into the core pad back surface 2b side, so that it is not necessary to seal the groove opening of the locking groove 22 covered by the thin plate portion 26 with tape prior to foam molding. Although the drawing showing the core pad 2 set in the upper mold 9 is omitted, in FIG. 5, the locking groove 22 is formed with a groove opening on the top surface 25a of the high part near the wall surface 251. In FIG. 10, the thin plate portion 26 is divided into three parts so that the thin plate portion 26 can slide on the inclined surface of the side wall 931 and the vertical surface 261 on the back outer peripheral edge 21 side can be easily pressed against the side wall 931, but it may be made into a single piece. In FIG. 9 and FIG. 10, the other configurations are the same as those described above in FIG. 1 to FIG. 8, and the explanation thereof will be omitted. The same reference numerals as those in FIG. 1 to FIG. 8 indicate the same or corresponding parts. Reference numeral 3B indicates a side portion, reference numeral 3D indicates an inclined surface, reference numeral 3E indicates a joint portion with the backrest, and reference numerals 391 and 392 indicate the vertical groove and horizontal groove of the hanging groove 39.

[0019] (2) Cushion Pad The cushion pad 1 obtained by the above-mentioned manufacturing method and the like in Fig. 1 to Fig. 8 is a vehicle cushion pad 1 in which the surface 2a side of the core pad 2 is covered with a surface layer pad 3 made of a soft polyurethane foam molded body. At least the receiving surface portion 31 on the side where an occupant comes into contact is formed of a soft polyurethane foam molded body, thereby forming the cushion pad 1 having the core pad 2 and the surface layer pad 3.

[0020] The core pad 2 is a mass-shaped bead foam molded body that occupies almost the lower half of the cushion pad 1. The core member is formed with a slice-shaped thin plate portion 26 having a facing surface of a size that matches the wall surface 251 on the back surface outer peripheral edge 21 side, with a gap ε, on the back surface outer peripheral edge 21 side, which extends from the outer peripheral edge side low part 24 to the raised high part 25 near the outer peripheral edge 21 of the back surface 2b. Both the wall surface 251 in the high part 25 and the vertical surface 261 of the thin plate portion 26 are provided along the back surface outer peripheral edge 21 of the core pad 2. The plate thickness of the thin plate portion 26 decreases from the base end portion connected to the low part 24 toward the tip portion. Furthermore, the vertical surface 261 of the thin plate portion 26 located on the outer peripheral edge side toward the tip portion 26a is inclined toward the wall surface 251 of the high part 25. The skin end engagement grooves 22 are provided near the outer periphery 21 of the back surface as shown in the figure, and are arranged at predetermined intervals around the entire periphery of the back surface outer periphery 21.

[0021] The surface pad 3 is a soft polyurethane foam molded body in which the core pad 2 is embedded and integrated with the back surface 2b of the core pad 2 exposed. A receiving surface portion 31 is formed on the design surface 3a side of the soft polyurethane foam molded body, while the inner surface 3b side opposite the design surface 3a is joined to the front surface 2a of the core pad 2. The surface pad 3 embeds and integrates the core pad 2 as an insert product in which the back surface 2b is exposed, with the side portion 32 covering the side surface 23 of the core pad 2 from the front surface 2a side to the back surface outer peripheral edge 21. The core pad 2 is wrapped in the surface pad 3 with the back surface 2b exposed, as shown in Figs. 1 and 8.

[0022] The cushion pad 1 is provided with a thin plate portion 26 for preventing the foaming raw material g from penetrating into the back surface 2b of the core pad during foam molding of the surface pad 3. In this embodiment, a slice-shaped thin plate portion 26 having an opposing surface of a size matching the wall surface 251 is formed upright on the back surface outer peripheral edge 21 side with a gap ε from the wall surface 251 of the elevated portion 25 (FIGS. 1 to 8). The foam molding of the surface pad 3 provides a desired cushion pad 1 in which the foaming raw material g is prevented from penetrating into the back surface 2b side of the core pad.

[0023] 9 shows another embodiment of the cushion pad 1, which is a core pad 2 in which the vertical surface 261 of the thin plate portion 26 is set to be longer along the rear outer peripheral edge 21 than the wall surface 251 of the high part 25. Also, FIG. 10 shows a cushion pad 1 in which the locking groove 22 is provided in the high part 25 on the rear side of the vehicle, and the thin plate portion 26, which is longer in the vehicle width direction and covers the locking groove 22 in the vehicle width direction, is set to be lowered. The core pad 2 is formed in an upright manner along the rear outer peripheral edge 21 of the cushion pad 24. The other configurations are the same as those described in (1) Method for manufacturing a cushion pad for a vehicle, and therefore the description will be omitted. The same reference numerals as those in (1) indicate the same or corresponding parts.

[0024] (3) Effects In the vehicle cushion pad and its manufacturing method thus constructed, the core pad 2 of the bead foam molded body, which is extremely light and has shape retention, is embedded and integrated with the surface pad 3 of the soft polyurethane foam molded body, making it possible to reduce the weight of the cushion pad 1. At the same time, at least the receiving surface portion 31 on the side where the occupant comes into contact is formed of the surface pad 3 of the soft polyurethane foam molded body, so that comfortable cushioning is maintained when the occupant sits down.

[0025] The core pad 2 of the bead foam molding is less likely to deform than the surface pad 3 with cushioning properties, but the thin plate portion 26 makes it flexible and can accommodate deformation. If the thin plate portion 26 is formed upright and has a surface facing the wall surface 251 of the high part 25 with a gap ε between them, the upper mold 9 on which the core pad 2 is set is provided with a recess 93, and the recess 93 is provided with a side wall 931 with an inclined surface approaching the center of the recess 93 from the entrance 930 toward the bottom surface 935, the thin plate portion 26 can slide along the inclined surface, and the vertical surface 261 on the back surface outer peripheral edge 21 side can be pressed against the side wall 931, so that the core pad 2 can be set well in the upper mold 9. Since the vertical surface 261 of the thin plate portion 26 can be pressed against the side wall 931 and sealed, the infiltration of the foaming raw material g around the back surface 2b of the core pad toward the center of the back surface during foam molding of the surface pad 3 can be stopped at the vertical surface 261. In molding the surface pad 3, a polyurethane film k is formed on the back surface 2b of the core pad 2, which eliminates the conventional problem of emitting friction noise after the cushion pad 1 is installed in the vehicle. There is also no need to attach nonwoven fabric or the like to cover the soft polyurethane film k on the back surface 2b of the core pad to prevent friction noise in a post-process after foam molding. By configuring the surface pad 3 to cover the side surface 23 of the core pad 2 up to the outer periphery 21 of the back surface, the side portion 32 of the surface pad 3 can also cover the side surface 23 of the core pad that is touched by the occupant, making it possible to provide a cushion pad 1 with good cushioning properties and feel.

[0026] Incidentally, the foamed bead body of the core pad 2 tends to shrink during foaming, making it easier for the foaming raw material g to penetrate into the back surface 2b of the core pad. However, by using an upper mold 9 with an inclined side wall 931 in which the recess 93 approaches the center of the recess 93 from the entrance 930 toward the bottom surface 935, the area in which the thin plate portion 26 can be pressed against the inclined side wall 931 when the core pad 2 is set in the upper mold 9 is expanded, and the cushion pad can be made to reliably prevent the foaming raw material g from penetrating into the back surface 2b of the core pad even if the core pad 2 shrinks in size to some extent. In addition, if the plate thickness of the thin plate portion 26 is reduced from the base end portion connected to the low portion 24 toward the tip portion, the thin plate portion 26 is provided with greater flexibility and can respond to deformation, so that it is more reliable to press the vertical surface 261 of the thin plate portion 26 against the side wall 931 to seal. In addition, if the vertical surface 261 is inclined toward the wall surface 251 of the elevated portion 25 toward the tip portion 26a of the thin plate portion 26, the deformation response becomes smoother, and the thin plate portion 26 slides on the inclined surface of the side wall 931, and the vertical surface 261 on the back surface outer peripheral edge 21 side is smoothly pressed against the side wall 931. This makes it easier to set the core pad 2 on the upper mold 9.

[0027] Furthermore, if the thin plate portion 26 is separated from the high part 25 by a gap ε running in the vehicle width direction and is provided along the outer peripheral edge in the vehicle width direction of the back surface of the rear side of the vehicle, the thin plate portion 26 effectively blocks the intrusion of the foaming raw material g from the rear side of the vehicle into the back surface 2b of the core pad during foam molding of the surface layer pad 3, so that the formation of a polyurethane film k due to the foaming raw material g wrapping around the back surface 2b of the core pad from the rear side of the vehicle, which was likely to occur in the past, can be eliminated. Furthermore, if the vertical surface 261 of the thin plate portion 26 is set to have a longer length along the back surface outer peripheral edge 21 than the wall surface 251 of the high part 25 as shown in FIG. 9, the long thin plate portion 26 can prevent the foaming raw material g from wrapping around the high part 25 over a wider range during foam molding of the surface layer pad 3. In this way, even if the side portion 32 of the surface layer pad 3 covers the side surface 23 of the core pad from the front surface 2a side to the back surface outer peripheral edge 21, the foaming raw material g will not wrap around the back surface 2b of the core pad during foam molding of the surface layer pad 3. This eliminates the problem of friction noise occurring after the cushion pad 1 is mounted on the vehicle, and the burden of attaching a nonwoven fabric or the like to the back surface 2b of the core pad to prevent the friction noise. In addition, the quality is stabilized, and the present invention has excellent effects in terms of eliminating the labor burden, stabilizing the quality, and improving the productivity.

[0028] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention according to the purpose and use. The shape, size, number, material, etc. of the core pad 2, low portion 24, high portion 25, thin plate portion 26, surface pad 3, foam molding die 7, depression 93, etc. can be appropriately selected according to the use. [Explanation of symbols]

[0029] 1 cushion pad 2 core pad 21 back outer periphery 23 side 24 low part 25 high part 251 wall surface 26 thin plate part 26a vertical surface 3 surface pad 31 receiving surface part 32 side part 81 lower mold cavity surface 9 upper mold 93 recess 931 side wall g foaming material

Claims

1. A core pad that forms a vehicle cushion pad by covering a surface and a side surface with a soft polyurethane foam molding, A bead foam molding, A low portion provided near the outer periphery of the back surface; a raised portion on the back surface that is raised from the low portion; A thin plate portion formed upright from the back surface, The thin plate portion is formed upright from the low portion so as to have a surface facing the wall surface on the outer peripheral edge of the back surface of the high portion extending from the low portion to the high portion, with a gap between the wall surface and the wall surface on the outer peripheral edge of the back surface, and is provided at a position spaced apart from the outer peripheral edge of the back surface.

2. A core pad that forms a vehicle cushion pad by covering a surface and a side surface with a soft polyurethane foam molding, A bead foam molding, A thin plate portion is provided that stands upright from the rear surface. The thin plate portion is flexible and is provided along the outer circumferential edge of the back surface at a position spaced apart from the outer circumferential edge of the back surface.

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