JP2021003449A - Foam molding product and molding method of the same - Google Patents

Abstract

To provide a foam molding product that can suppress generation of shrinkage on a surface of a thin part, and to provide a molding method of the same.SOLUTION: A foam molding product 1 constitutes a backrest part 7 as a part of a vehicle seat. The foam molding product 1 includes: a body part 10; a rear side 102 of the body part 10; and a rear side material 2 which is installed on the rear side 102 of respective wall parts 111, 121 as thin parts, in an upper part 11 and both side parts 12R, 12L as a marginal part of the body part 10. In the rear side material 2, there is formed a notched part 25 having a notched shape so that a part of the rear side 102 of the wall part 121 of the right side part 12R is exposed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a foam molded product and a molding method thereof.

The seat and backrests of the vehicle seat are formed by covering a foam molded product made of a foamable raw material with a skin. A foam-molded product is molded by foaming and filling a foamable raw material in a mold. In the foam molded product, fine bubbles (foam cells) due to the foamable raw material are dispersed. Further, a skin is arranged on the front surface side of the foam molded product, and a metal seat frame and a spring are arranged on the back surface side of the foam molded product to form a seat portion or a backrest portion of the seat. Further, on the back surface side of the foam molded product, a back surface material may be arranged to prevent the generation of abnormal noise generated when the foam molded product and the seat frame and the spring rub against each other.

For example, in the seat pad of Patent Document 1, overhanging portions are integrally provided on the upper side portion and the left and right both side portions on the back surface side of the pad body made of foamed resin, and the overhanging portions are continuously provided from the back surface of the pad main body to the overhanging portion. A reinforcing sheet is provided. The reinforcing sheet is formed up to the overhanging tip of the overhanging portion in order to reinforce the pad body and the overhanging portion.

JP-A-2007-82909

In recent years, in order to reduce the weight and size of foam-molded products, there is a demand for thinning the portion protruding from the edge of the main body of the foam-molded product. However, in order to reduce the thickness of the portions protruding from the edge of the foam molded product, it is necessary to narrow the width of the cavity for molding these portions in the molding die. Therefore, it becomes difficult for the effervescent raw material to pass through this cavity.

In particular, when the back surface material is arranged in this cavity, a state in which the foamable raw material is more difficult to pass is formed by the thickness of the back surface material. As a result, it is difficult for the foamable raw material to be filled in the cavity, and the fine air bubbles in the thinned portion (thin-walled portion) of the foamed molded product may be crushed, resulting in sink marks on the surface of the foamed molded product. There is.

In the sheet pad of Patent Document 1, the thickness of the connecting portion at the overhanging portion is thinner than the thickness of the flange portion located on the tip side thereof, and the reinforcing sheet is arranged on the connecting portion and the flange portion. There is. Therefore, when the sheet pad is foam-molded in the molding die, sink marks may occur at the connecting portion of the molded sheet pad.

The present invention has been made in view of such a problem, and has been obtained in an attempt to provide a foam molded product capable of suppressing the occurrence of sink marks on the surface of a thin-walled portion and a molding method thereof.

According to the first invention, a part of a vehicle seat is formed, a main body portion, a thin-walled portion formed at an edge portion of the main body portion to be thinner than the main body portion, and the back surface of the main body portion and the thin-walled portion. It is a method of molding a foam molded product having a back surface material provided on the side.
A molding die composed of a lower mold for molding a part of the foam molded product and an upper mold for molding the rest of the foam molded product which is relatively openable and closable with respect to the lower mold. Using
The back surface material arranging step in which the back surface material having the notched portion formed so as to expose a part of the back surface side of the thin wall portion is arranged in the upper mold,
An injection step in which the effervescent raw material is injected into the lower mold and the upper mold is closed relative to the lower mold.
The foamable raw material is filled in a cavity formed between the molding surface of the lower mold and the molding surface of the upper mold, and the back surface material is provided on the back surface side of the main body portion and the thin wall portion. The present invention includes a molding step of molding a foam-molded product in which a part of the back surface side of the thin-walled portion is exposed by the notch portion of the back surface material, and a molding method of the foam-molded product.

The second invention is a foam molded product that constitutes a part of a vehicle seat.
With the main body
A thin-walled portion formed at the edge of the main body portion to be thinner than the main body portion,
It has a back surface material provided on the back surface side of the main body portion and the thin wall portion.
The back surface material is a foam molded product in which a notch portion having a notched shape is formed so as to expose a part of the back surface side of the thin wall portion.

(Molding method for foam molded products)
In the molding method of the foam molded product of the first invention, when the back surface material is arranged on the thin wall portion of the foam molded product, the foam molding of the thin wall portion is not hindered by the back surface material. A notch portion having a shape in which a part of this portion is notched is formed in a portion of the back surface material used in this molding method which is arranged on the back surface side of the thin-walled portion. Then, when the back surface material placement step and the injection step are performed and the back surface material is placed in the molding die, in the cavity for molding the thin-walled portion in the molding die, the portion where the back surface material is placed and the portion where the back surface material is placed, The notch forms a portion where the back surface material is not arranged. Then, in the portion of the cavity where the back surface material is not arranged, the width of the cavity is increased due to the absence of the back surface material, and the foamable raw material can easily pass through.

As a result, in the foamed molded product after molding, the foamable raw material can be smoothly filled in the entire thin-walled portion, and fine bubbles (foam cells) in the portion constituting the entire thin-walled portion can be prevented from being crushed. .. Therefore, according to the molding method of the foam molded product of the first invention, it is possible to suppress the occurrence of sink marks on the surface of the thin-walled portion of the foam molded product.

The "notch portion" means a portion where a part of the back surface material arranged in the thin-walled portion is intentionally removed. The "notch portion" can be formed by cutting out a part of the auxiliary material for forming the back surface material. Further, the "notch portion" may be formed as a notch shape even if the auxiliary material is not cut out and formed.

(Effervescent molded product)
A notch portion having a shape in which a part of this portion is notched is formed in a portion of the back surface material of the foam molded product of the second invention arranged on the back surface side of the thin-walled portion. In the foam molded product, the fine bubbles (foam cells) in the portion constituting the entire thin-walled portion are hardly crushed. Therefore, according to the foam-molded product of the second invention, it is possible to obtain a foam-molded product in which the occurrence of sink marks on the surface of the thin-walled portion of the foam-molded product is suppressed. In addition, the foamed molded product has almost no poor appearance, and even when the surface side of the foamed molded product is covered with the epidermis, the epidermis does not wrinkle, and the appearance of the epidermis can be maintained well.

FIG. 1 is a perspective view showing an effervescent molded product constituting a backrest portion according to an embodiment. FIG. 2 is a sectional view taken along line II-II in FIG. 1 according to the embodiment. FIG. 3 is a sectional view taken along line III-III in FIG. 1 according to the embodiment. FIG. 4 is a perspective view showing a back surface material according to the embodiment. FIG. 5 is a perspective view showing a molding mold according to the embodiment. FIG. 6 is a VI-VI cross-sectional equivalent view of FIG. 5 showing a molded mold in a closed state according to the embodiment.

A preferred embodiment of the molding method of the first invention and the foam molded product of the second invention described above will be described. The composition of the foam molded product and the back surface material in the first invention and the second invention can be as follows.

The foam-molded product constitutes a backrest portion of the sheet, and the thin-walled portion is rearward from at least one of the upper, lower, right-side, and left-side edges of the main body of the backrest. It may be formed as an extended wall portion. With this configuration, it is possible to obtain a backrest portion of the sheet in which the occurrence of sink marks on the surface of the thin-walled portion of the foam molded product is suppressed.

Further, the thin-walled portion is formed as a wall portion extending rearward from the edge portion of at least one side portion of both side portions of the main body portion, and the notch portion of the back surface material is the thin-walled portion. It may be formed by notching the lower side of the total length of the portion in the vertical direction. With this configuration, the effervescent raw material can easily enter the cavity for molding the thin-walled portion, and the occurrence of sink marks in the effervescent molded product can be effectively suppressed. Further, by leaving the upper side (the part excluding the lower side) of the thin-walled portion in the vertical length of the back surface material, the thin-walled portion can be reinforced, and the back surface material is raised in the back surface material arranging process. The backing material can be easily placed on the upper mold by securing a lot of parts that can be fastened to the mold.

Further, the wall portion is continuously formed on the upper portion and both side portions of the main body portion, and a bent portion bent so as to face the main body portion is formed on the upper portion and the edge portion of the wall portion. Even if the back surface material is continuously formed on both side portions and is continuously arranged from the back surface side of the main body portion to the back surface side of the wall portion and the bent portion, the back surface material is formed in a bag shape. Good. With this configuration, in the back surface material arranging step, the bag-shaped back surface material can be easily arranged on the upper mold so as to cover the upper mold.

Further, among the edge portions forming the notch portion in the back surface material, the portion arranged on the wall portion extending rearward from the edge portion of the side portion of the main body portion has a concave shape formed by a curved line. May have. With this configuration, in the backing material arranging process, the part corresponding to the wall part of the side part of the backing material can be made difficult to open with respect to the part corresponding to the main body part of the backing material, and the backing material is stabilized in the upper mold. Can be placed.

Further, the foam molded product is used by being mounted on a seat frame, and the notch portion faces a portion of the seat frame where a soft member softer than the seat frame is provided. It may be arranged. With this configuration, in the portion of the foam molded product in which the notch portion is formed in the back surface material, the soft member prevents the generation of abnormal noise generated when the foam molded product and the seat frame rub against each other.

The molding method of the first invention and the embodiment of the foam molded product of the second invention described above will be described with reference to the drawings.
<Embodiment>
As shown in FIGS. 1 to 4, the foam-molded article 1 of the present embodiment constitutes a backrest portion (seat back) 7 as a part of a vehicle seat. The foam molded product 1 is provided on the main body portion 10, the back surface side 102 of the main body portion 10, and the back surface side 102 of the wall portions 111 and 121 of the upper portion 11 and both side portions 12R and 12L as the edge portion of the main body portion 10. It also has a back surface material 2. The wall portions 111 and 121 are formed as thin-walled portions as compared with the main body portion 10. The back surface material 2 is formed with a notch portion 25 having a shape notched so as to expose a part of the foam on the back surface side 102 of the wall portion 121 of the right side portion 12R.

The molding method of the foam molded product 1 and the foam molded product 1 of this embodiment will be described in detail below.
(Effervescent molded product 1)
As shown in FIGS. 1 to 3, the foam molded product 1 constitutes the backrest portion 7 of the seat of an automobile. The seat of an automobile is composed of a seat portion and a backrest portion 7. The main body 10 of the foam molded product 1 constituting the backrest 7 shows a central portion surrounded by an upper portion 11, a right side portion 12R, a left side portion 12L, and a lower portion 13.

Wall portions 111 and 121 are extended and formed behind the edges of the upper portion 11, the right side portion 12R and the left side portion 12L of the main body portion 10, respectively. The wall portions 111 and 121 are continuously formed on the upper portion 11 of the main body portion 10 and the side portions 12R and 12L. In other words, the wall portion 111 formed on the upper portion 11 and the wall portion 121 formed on the side portions 12R and 12L are connected to each other. On the edges of the wall portions 111 and 121, bent portions 112 and 122 bent so as to face the main body portion 10 are continuously formed on the upper portion 11 and both side portions 12R and 12L.

The wall portion 111 formed on the upper portion 11 is formed from the end portion of the upper side H1 in the vertical direction H of the main body portion 10 toward the rear D2 in the front-rear direction D. At the end of the rear D2 of the wall portion 111, a bent portion 112 extending toward the lower side H2 in the vertical direction H is formed. The bent portion 112 is bent with respect to the wall portion 111 with a space S open to the main body portion 10.

The wall portions 121 formed on the right side portion 12R and the left side portion 12L are formed from the left and right ends of the main body portion 10 in the vehicle width direction W toward the rear D2 in the front-rear direction D. At the end of the rear D2 of each wall portion 121, a bent portion 122 extending inward in the vehicle width direction W is formed. The bent portion 122 is formed in a shape that is bent with respect to the wall portion 121 in a state where the space S is opened with respect to the main body portion 10.

The space S refers to a space located between the main body portion 10 and the bent portions 112 and 122 of the wall portions 111 and 121. The bent portion 112 formed on the wall portion 111 of the upper portion 11 and the main body portion 10 face each other with the space S, and the bent portion 122 and the main body formed on the wall portions 121 of the side portions 12R and 12L face each other. The portion 10 faces the portion 10 via the space S.

The bent portion 112 may not be formed on the wall portion 111 formed on the upper portion 11. Further, the bent portions 122 may not be formed on the wall portions 121 formed on both side portions 12R and 12L. Further, the wall portion may be formed in the lower portion 13 of the foam molded product 1 constituting the backrest portion 7.

As shown in FIGS. 1 to 3, the upper portion 11 of the foam molded product 1 constituting the backrest portion 7 is a portion located on the upper side H1 in the vertical direction H when the backrest portion 7 is mounted on an automobile. To say. The lower portion 13 of the foam molded product 1 refers to a portion located on the lower side H2 of the vertical direction H when the backrest portion 7 is mounted on an automobile. The side portions 12R and 12L of the foam molded product 1 refer to portions located on both sides of the vehicle width direction W of the vehicle when the backrest portion 7 is mounted on the vehicle.

Further, the surface side 101 of the foam-molded product 1 constituting the backrest portion 7 means the outside of the foam-molded product 1 on which the skin is provided. The back surface side 102 of the foam molded product 1 refers to the side opposite to the front surface side 101 and the inside of the foam molded product 1. In the main body 10 of the foam molded product 1, the front surface side 101 is directed to the front D1 in the automobile, and the back surface side 102 is directed to the rear D2 in the automobile. The thickness direction of the wall portions 111, 121 means the direction in which the front surface side 101 and the back surface side 102 of the wall portions 111, 121 face each other.

As shown in FIG. 3, the thickness t2 of the wall portion 121 as the thin portion of the right side portion 12R of the foam molded product 1 is the thickness t1 of the main body portion 10, the thickness t3 of the wall portion 121 of the left side portion 12L, and It is smaller than the thickness of the wall portion 111 of the upper portion 11.

Although not shown, an armrest is attached to the wall portion 121 of the right side portion 12R of the foam molded product 1 constituting the backrest portion 7. As shown in FIG. 1, a through hole 15 as a mounting hole for mounting the armrest is formed in the wall portion 121 of the right side portion 12R. The through hole 15 in the wall portion 121 of the right side portion 12R penetrates the wall portion 121 toward the vehicle width direction W (thickness direction of the wall portion 121) of the foam molded product 1.

Although the back surface material 2 such as felt is provided on the back surface side 102 of the foam molded product 1 of the present embodiment, sink marks do not occur on the upper portion 11, both side portions 12R, 12L, etc. of the foam molded product 1. Here, in the "sink", when the foamable raw material 100 of the resin foams, innumerable fine bubbles (foam cells) are locally crushed inside or on the surface of the foam molded product 1, and the foam molded product 1 Means that a predetermined shape cannot be obtained.

(Backrest 7)
As shown in FIGS. 1 to 3, the foam molded product 1 constituting the backrest portion 7 of the seat is used by being attached to the seat frame 3 constituting the backrest portion 7. The backrest portion 7 is arranged at the rear end position of the seat portion of the seat. At the lower part of the backrest portion 7, a shaft portion (not shown) for tilting the backrest portion 7 back and forth is arranged. The backrest portion 7 is a seat component including a foam molded product 1, a skin covering the front surface side 101 of the foam molded product 1, and a seat frame 3 mounted on the back surface side 102 of the foam molded product 1. The seat frame 3 has a frame portion 31 formed in a frame shape by a metal pipe, and a metal spring portion (not shown) provided inside the frame portion 31 and elastically deformable.

In FIG. 1, each portion of the main body portion, upper portion, both side portions, and lower portion of the backrest portion 7 is shown as the main body portion 10, the upper portion 11, both side portions 12R, 12L, and the lower portion 13 of the foam molded product 1. Further, in FIGS. 1 to 3, the skin and the spring portion are not shown. The epidermis is composed of epidermis materials such as woven fabrics, knitted fabrics, and artificial leathers. The spring portion is made of a metal wire or the like, is supported by the frame portion 31, and receives the load of the occupant seated on the seat.

The frame portion 31 of the seat frame 3 is arranged on each back surface side 102 of the upper portion 11, both side portions 12R and 12L, and the lower portion 13 in the main body portion 10 of the foam molded product 1. At the portion of the back surface side 102 of the foam molded product 1 where the back surface material 2 is arranged, since the back surface material 2 is present, the foam and the frame portion 31 do not come into direct contact with each other, and no abnormal noise is generated.

On the back surface side 102 of the foam molded product 1, in the portion of the frame portion 31 facing the notch portion 25 in which the back surface material 2 is cut out, as shown in FIGS. 1 and 4, the frame portion 31 The outer circumference is covered with a soft member 32 that is softer than the metal material constituting the frame portion 31. In other words, the notch portion 25 of the back surface member 2 is arranged to face the portion of the frame portion 31 where the soft member 32, which is softer than the frame portion 31, is provided. As a result, in the portion of the foam molded product 1 corresponding to the notch portion 25 of the back surface material 2, the foam and the frame portion 31 do not come into direct contact with each other, and no abnormal noise is generated. The soft member 32 of this embodiment is made of felt (nonwoven fabric) formed of a fiber material.

(Back material 2)
As shown in FIG. 4, the back surface material 2 is provided on the back surface side 102 of the foam molded product 1 to reinforce the back surface side 102 of the foam molded product 1, and the foam of the foam molded product 1 is the sheet frame 3. This is to prevent the generation of abnormal noise by preventing direct contact. The back surface material 2 is made of a felt (nonwoven fabric) sheet. The back surface material 2 is formed in a bag shape that is continuously arranged from the back surface side 102 of the main body portion 10 to the back surface side 102 of the wall portions 111, 121 and the bent portions 112, 122.

The back surface material 2 is formed in a bag shape by sewing appropriate parts of the felt sheet together. For example, the back surface material 2 has a wall portion 111 and a bent portion 112 of the upper portion 11 at a corner portion between the wall portion 111 and the bent portion 112 of the upper portion 11 and the wall portion 121 and the bent portion 122 of both side portions 12R and 12L. The sheet portion 21 arranged in the above and the sheet portion 22 arranged in the wall portions 121 and the bent portions 122 of the side portions 12R and 12L can be sewn together to form a bag shape. The sewn portion between the sheet portions 21 and 22 is indicated by the alternate long and short dash line E.

The sheet portion 21 arranged on the wall portion 111 and the bent portion 112 of the upper portion 11 of the back surface material 2, and the sheet portion arranged on the wall portions 121 and the bent portion 122 of both side portions 12R and 12L of the back surface material 2. 22 is formed continuously. With this configuration, as shown in FIG. 5, the bag-shaped back surface material 2 can be easily arranged on the core mold portion 521 of the upper mold 52 so as to cover the core mold portion 521 of the upper mold 52. ..

The back surface material 2 also includes a sheet portion 20 arranged on the back surface side 102 of the main body portion 10 and a sheet portion 23 arranged on the back surface side 102 of the lower portion 13. The back surface material 2 does not necessarily have to be sewn together with the sheet portions 21 and 22, and may have a bag shape when arranged in the core mold portion 521 of the upper mold 52.

As shown in FIGS. 1 and 4, in the cutout portion 25 of the back surface material 2 of the present embodiment, the lower portion of the wall portion 121 and the bent portion 122 in the vertical direction H of the right side portion 12R is cut out. It is formed by More specifically, the notch portion 25 is formed by notching the wall portion 121 of the right side portion 12R and the bent portion 122 in the range h1 of 1/2 from the lower end in the total length h in the vertical direction H. There is. Further, since the cutout portion 25 is formed in the wall portion 121 of the right side portion 12R, the upper and lower sides of the wall portion 121 of the right side portion 12R are higher and lower than the length hl of the wall portion 121 of the left side portion 12L in the vertical direction H. The length hr in the direction H is short. The length of the vertical direction H means the distance from the uppermost end to the lowermost end of the vertical direction H of the wall portion 121.

The “notch portion 25” refers to a portion where a part of the back surface material 2 arranged on the wall portion 121 of the right side portion 12R is intentionally removed. Due to the formation of the notch portion 25, in the foam molded product 1, the foam is exposed on the wall portion 121 of the right side portion 12R and the back surface side 102 of the bent portion 122.

Since the cutout portion 25 is formed in the lower portion of the wall portion 121 and the bent portion 122 of the right side portion 12R of the back surface material 2, the foamable raw material 100 is placed on the right side portion during molding of the foam molded product 1. It becomes easy to enter the cavity 53 for forming the lower portion of the wall portion 121 and the bent portion 122 of the 12R. Further, in the back surface material 2, the wall portion 121 and the bent portion 122 of the right side portion 12R are left, so that the wall portion 121 and the bent portion 122 of the right side portion 12R can be reinforced. At the time of molding the foam molded product 1, the back surface material 2 can be easily arranged on the upper mold 52 by securing a large number of portions where the back surface material 2 can be fastened to the upper mold 52.

As shown in FIG. 4, among the edge portions forming the notch portion 25 in the back surface material 2, the portions arranged on the wall portion 121 and the bent portion 122 extending rearward from the edge portion 120 of the right side portion 12R. Has a concave shape composed of curved lines. With this configuration, in the backing material arranging step at the time of molding the foam molded product 1, the sheet corresponding to the wall portion 121 of the right side portion 12R of the backing material 2 with respect to the sheet portion 20 corresponding to the main body portion 10 of the backing material 2. The portion 22 can be made difficult to open, and the back surface member 2 can be stably arranged on the core mold portion 521 of the upper mold 52.

Since the notch portion 25 has a concave shape, the lower end position of the lower portion of the sheet portion 22 arranged in the wall portion 121 and the bent portion 122 of the right side portion 12R of the back surface material 2 in the vertical direction H is , The wall portion 121 and the bent portion 122 are different. Further, the concave notch 25 of the present embodiment is formed around the through hole 15 so as to avoid the through hole 15.

(Molding mold 5 of foam molded product 1)
As shown in FIGS. 5 and 6, the molding die 5 is for molding the foam molded product 1, with respect to the lower mold 51 for molding a part of the foam molded product 1 and the lower mold 51. It is relatively openable and closable via the hinge portion 54, and is composed of an upper mold 52 for molding the remaining portion of the foam molded product 1. Mainly, the front surface side of the backrest portion 7 is formed by the lower mold 51, and the rear surface side of the backrest portion 7 is formed by the upper mold 52.

The upper mold 52 is connected to the core mold portion 521 for molding the back surface side (inner portion) 102 of the wall portions 111 and 121 of the foam molded product 1 and the core mold portion 521, and is connected to the core mold portion 521 to form the wall in the foam molded product 1. It is composed of an outer mold portion 522 for molding the surface side (outer portion) 101 of the portions 111 and 121. The back surface material 2 is arranged on the core mold portion 521 so as to cover the core mold portion 521 of the upper mold 52. The back surface material 2 may be provided with a magnetic member such as an iron powder tape or a magnet to prevent the back surface material 2 from coming off from the metal core mold portion 521. The magnetic members can be provided at a plurality of locations on the back surface material 2.

The width T2 of the cavity 53 for molding the wall portion 121 as a thin portion of the right side portion 12R of the backrest portion 7 is the width T1 of the cavity 53 for molding the main body portion 10, and the wall portion 121 of the left side portion 12L is molded. It is smaller than the width T3 of the cavity 53 for forming and the width of the cavity 53 for forming the wall portion 111 of the upper portion 11. The width T2 of the cavity 53 for forming the wall portion 121 of the right side portion 12R is the smallest in the width of each portion in the entire cavity 53. Here, the widths T1, T2, and T3 of the cavity 53 refer to the widths corresponding to the thickness directions of the main body portion 10, the wall portions 111, 121, and the bent portions 112, 122 in the foam molded product 1.

The width T2 of the cavity 53 for forming the wall portion 121 of the right side portion 12R is 25 mm or less. When the back surface material 2 is arranged in the cavity 53 having a width T2 of 25 mm or less, sink marks are likely to occur, and when the back surface material 2 is arranged in the cavity 53 having a width T2 of 15 mm or less, sink marks are particularly likely to occur. On the other hand, the widths T1 and T3 of the cavities 53 for forming the wall portion 111 of the main body portion 10, the upper portion 11 and the wall portion 121 of the left side portion 12L exceed 25 mm. The thickness of the back surface material 2 can be, for example, in the range of 2.5 to 3 mm.

(Molding method and action effect of foam molded product 1)
In molding the foam molded product 1, as shown in FIG. 5, a backing material arranging step, an injection step, and a molding step are performed using a molding die 5 having a lower mold 51 and an upper mold 52. In the back surface material arranging step, the upper die 52 is opened with respect to the lower die 51, and the back surface material 2 on which the notch portion 25 is formed is covered with the core die portion 521 of the upper die 52, and is middled by a magnetic member. It is attached to the child mold portion 521. In the injection step, as shown in FIG. 6, the foaming raw material 100 is injected into the lower mold 51, and the upper mold 52 is closed with respect to the lower mold 51.

Next, in the molding step, the effervescent raw material 100 spreads while foaming in the cavity 53 between the lower mold 51 and the upper mold 52. Then, the foamable raw material 100 is for molding the upper portion 11, both side portions 12R, 12L, the lower portion 13, the wall portions 111, 121, and the bent portions 112, 122 from the cavity 53 for molding the vicinity of the main body portion 10. The cavity 53 is filled. Further, the foamable raw material 100 in the cavity 53 flows upward and laterally while foaming.

When the foamable raw material 100 flows upward through the cavity 53 for molding the wall portion 111 of the upper portion 11 and the wall portion 121 of the left side portion 12L, the foamable raw material 100 is formed of the back surface material 2 and the lower mold 51. It flows between the faces. At this time, in particular, the width T3 of the cavity 53 for molding the wall portion 111 of the upper portion 11 and the wall portion 121 of the left side portion 12L exceeds 25 mm, and the foamable raw material 100 is a fine bubble due to foaming. It flows while forming innumerable foam cells, and is filled between the back surface material 2 and the molding surface of the lower mold 51.

On the other hand, when the foamable raw material 100 flows upward through the cavity 53 for molding the wall portion 121 of the right side portion 12R, the foamable raw material 100 is a back material in the upper portion of the wall portion 121 of the right side portion 12R. It flows between 2 and the molding surface of the lower mold 51. Further, at this time, since the back surface material 2 is not arranged in the lower portion of the wall portion 121 of the right side portion 12R, the foamable raw material 100 has the molding surface of the upper mold 52 and the molding surface of the lower mold 51. Flow between and.

In this way, the foamable raw material 100 corresponds to the cavity 53 between the back surface material 2 arranged in the core mold portion 521 of the upper mold 52 and the molding surface of the lower mold 51, and the notch portion 25 of the back surface material 2. A foam that fills the cavity 53 between the molding surface of the core mold portion 521 of the upper mold 52 and the molding surface of the lower mold 51, is heated and hardened, and has innumerable bubbles (foam cells) due to foaming. Become. Then, the back surface member 2 is provided on the back surface side 102 of the main body portion 10, the wall portions 111, 121 and the bent portions 112, 122, and the back surface side of the wall portion 121 of the right side portion 12R is provided by the notch portion 25 of the back surface material 2. A foam molded product 1 in which the lower portion of 102 is exposed is molded.

In the molding method of the foam molded product 1, when the back surface material 2 is arranged on the wall portions 111, 121 and the bent portions 112, 122 of the foam molded product 1, the back surface material 2 bends the wall portions 111, 121 and The foam molding of parts 112 and 122 is prevented from being hindered. In the portion of the back surface material 2 used in this molding method, which is arranged on the wall portion 121 of the right side portion 12R and the back surface side 102 of the bent portion 122, a notch portion 25 in which the lower portion of this portion is cut out is provided. It is formed.

Then, when the back surface material arranging step and the injection step are performed and the back surface material 2 is arranged in the molding die 5, the wall portion 121 and the bent portion 122 of the right side portion 12R in the molding die 5 are molded. In the cavity 53, a portion where the back surface material 2 is arranged and a portion where the back surface material 2 is not arranged are formed by the notch 25. Then, in the portion of the cavity 53 where the back surface material 2 is not arranged, the width of the cavity 53 is increased due to the absence of the back surface material 2, and the foamable raw material 100 can easily pass through.

As a result, in the foam-molded product 1 of the backrest portion 7 after molding, the foamable raw material 100 is smoothly filled in the entire wall portion 121 of the right side portion 12R, and the portion constituting the entire wall portion 121 of the right side portion 12R. It is possible to prevent fine bubbles (foaming cells) from being crushed. Therefore, according to the molding method of the foam molded product 1, it is possible to suppress the occurrence of sink marks on the surfaces of the wall portion 121 and the bent portion 122 of the right side portion 12R of the foam molded product 1.

(Effect of foam molded product 1)
In the foam molded product 1, the back surface material 2 has a notch portion having a shape in which the lower portion of this portion is cut out at a portion arranged on the wall portion 121 of the right side portion 12R and the back surface side 102 of the bent portion 122. 25 is formed. In the foam molded product 1, the fine air bubbles in the portion constituting the entire wall portion 121 and the bent portion 122 of the right side portion 12R are hardly crushed. Therefore, according to the foam molded product 1, it is possible to obtain the foam molded product 1 in which the occurrence of sink marks on the surfaces of the wall portion 121 and the bent portion 122 of the right side portion 12R of the foam molded product 1 is suppressed. Further, the foam molded product 1 has almost no poor appearance, and even when the surface side 101 of the foam molded product 1 is covered with the epidermis, the epidermis does not wrinkle and the appearance of the epidermis can be maintained well. it can.

Further, the thin portion of the backrest portion 7 may be the wall portion 121 of the left side portion 12L or the wall portion 111 of the upper portion 11 in addition to the wall portion 121 of the right side portion 12R. In this case, the notch portion 25 in the back surface member 2 can be formed at a portion arranged on the wall portion 121 of the left side portion 12L or the wall portion 111 of the upper portion 11. Further, the thin-walled portion may be a wall portion formed in the lower portion 13, and a notch portion 25 in the back surface material 2 may be arranged on the wall portion.

The present invention is not limited to the embodiment, and further different embodiments can be configured without departing from the gist thereof. The present invention also includes various modifications, modifications within an equal range, and the like. Further, the technical idea of the present invention also includes combinations, forms, etc. of various components assumed from the present invention.

Further, the foam molded product 1 provided with the back surface material 2 of the present embodiment is not limited to the one constituting the backrest portion of the seat, and may also constitute the seat portion (seat cushion) of the seat.

1 Foam molded product 101 Front side 102 Back side 11 Upper 111 Wall (thin wall)
12R Right side 12L Left side 121 Wall (thin wall)
13 Lower part 2 Back material 25 Notch part 3 Seat frame 31 Frame part 32 Soft member 5 Molding mold 51 Lower mold 52 Upper mold 53 Cavity 7 Backrest

Claims (8)

A part of the seat of the vehicle is formed, and the main body portion, the thin-walled portion formed at the edge portion of the main body portion to be thinner than the main body portion, and the main body portion and the back surface side of the thin-walled portion are provided. It is a method of molding a foam molded product having a backing material.
A molding die composed of a lower mold for molding a part of the foam molded product and an upper mold for molding the rest of the foam molded product which is relatively openable and closable with respect to the lower mold. Using
The back surface material arranging step in which the back surface material having the notched portion formed so as to expose a part of the back surface side of the thin wall portion is arranged in the upper mold,
An injection step in which the effervescent raw material is injected into the lower mold and the upper mold is closed relative to the lower mold.
The foamable raw material is filled in a cavity formed between the molding surface of the lower mold and the molding surface of the upper mold, and the back surface material is provided on the back surface side of the main body portion and the thin wall portion. A method for molding a foam-molded product, comprising a molding step of molding a foam-molded product in which a part of the back surface side of the thin-walled portion is exposed by the notch portion of the back surface material. The foam molded product constitutes the backrest portion of the sheet.
The thin-walled portion according to claim 1, wherein the thin-walled portion is formed as a wall portion extending rearward from at least one edge of an upper portion, a lower portion, a right portion portion, and a left side portion of the main body portion in the backrest portion. Molding method for foam molded products. The thin-walled portion is formed as a wall portion extending rearward from the edge portion of at least one side portion of both side portions of the main body portion.
The method for molding a foam molded product according to claim 2, wherein the cutout portion of the back surface material is formed by notching the lower side of the thin wall portion in the total length in the vertical direction. The wall portion is continuously formed on the upper portion and both side portions of the main body portion.
Bent portions bent so as to face the main body portion are continuously formed on the upper portion and both side portions of the edge portion of the wall portion.
The method for molding a foam-molded article according to claim 3, wherein the back surface material is formed in a bag shape that is continuously arranged from the back surface side of the main body portion to the back surface side of the wall portion and the bent portion. .. Of the edges forming the notch portion in the back surface material, the portion arranged on the wall portion extending rearward from the edge portion of the side portion of the main body portion has a concave shape formed by a curved line. , The method for molding a foam molded product according to any one of claims 1 to 4. Effervescent molded product that forms part of the vehicle seat
With the main body
A thin-walled portion formed at the edge of the main body portion to be thinner than the main body portion,
It has a back surface material provided on the back surface side of the main body portion and the thin wall portion.
A foam-molded product in which a notch portion having a notched shape is formed on the back surface material so as to expose a part of the back surface side of the thin-walled portion. The foam molded product is used by being attached to a seat frame.
The foam-molded article according to claim 6, wherein the cutout portion is arranged so as to face a portion of the seat frame where a soft member softer than the seat frame is provided. The main body portion constitutes the backrest portion of the seat.
The foam-molded article according to claim 6, wherein the thin-walled portion is formed as a wall portion extending rearward from at least one of the upper, lower, right-side, and left-side edges of the main body. ..

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