JP2017070628A - Seat pad and method for manufacturing seat pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a seat pad that suppresses discomfort, improves human body fitting feeling and increases stability of a seating posture.SOLUTION: A seat cushion pad 18 includes: a resin foam cushion material 20 for supporting load of an occupant P; and a planar elasticity imparting member 22 embedded in the cushion material 20 so as to be surrounded wholly by the cushion material 20, curved so as to be projected toward a rear face and having higher flexural rigidity than that of the cushion material 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a seat pad used for a seat and a method for manufacturing the seat pad.

  A seat pad having cushioning properties is used for a vehicle seat (see, for example, Patent Document 1).

  The seat pad of patent document 1 is adding the elasticity provision member made into the flat sheet form to the cushion material, and it is not reaching a bottom-butting state, but has improved the holding | maintenance property of a driver | operator's attitude | position.

Japanese Patent Application Laid-Open No. 2005-131277.

  In the seat pad of Patent Document 1, since the elasticity-imparting member is fixed to the mold and subjected to foam molding, a part of the periphery of the elasticity-imparting member appears to be exposed from the surface of the seat pad. For this reason, a load is applied to the elasticity imparting member to cause deformation, and at the same time, the surface of the cushion material around the portion exposed on the surface of the elasticity imparting member is pulled by the elasticity imparting member, and the occupant may feel uncomfortable.

  Further, in the seat pad, further improvement is desired in terms of holding the occupant against the human body fit feeling, the rolling and lateral G of the vehicle, in other words, the lateral acceleration.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a seat pad and a method for manufacturing the seat pad, which improve the bottom sensation while suppressing a sense of incongruity, improving the fit of the human body, and improving the stability of the sitting posture. In addition, the seat pad of this invention is applicable not only to a seat part but a backrest part.

  The seat pad according to claim 1 is a foamed resin cushion material that supports a passenger's load, and is embedded in the cushion material so as to be entirely surrounded by the cushion material, and a center side in the width direction of the passenger is the passenger side. Is curved so as to be convex toward the back surface opposite to the front surface, has higher bending rigidity than the cushion material, and extends from one side to the other side in the width direction of the occupant. And an elasticity imparting member.

  When a passenger's load acts on the seat pad, the cushion member is compressed and the elasticity imparting member is deformed to support the passenger's load. Since the elasticity imparting member is embedded in the cushion material, it is possible to suppress the feeling of bottoming. The elasticity applying member is embedded in the cushioning material so as to be entirely surrounded by the cushioning material, and is not exposed to the cushioning material surface, so that the distance between the elasticity applying member and the cushioning material surface is increased and the elasticity applying member is increased. At the time of deformation, the cushion material surface is hardly pulled by the elasticity-imparting member, and the occupant is less likely to feel uncomfortable.

  In addition, the elasticity-imparting member has a surface shape with higher bending rigidity than the cushion material, and is curved so that the center side in the width direction of the occupant is convex toward the back surface side, compared to a flat elasticity-imparting member. The shape is in line with the shape of the passenger's buttocks. For this reason, the seat pad according to claim 1 can secure a deflection that fits the human body as compared with the seat pad using a flat elasticity imparting member, thereby improving the fit of the human body, Since the occupant can be held by the elasticity imparting member that is curved when the lateral G is added, the stability of the sitting posture can be improved.

  The invention according to claim 2 is the seat pad according to claim 1, wherein the cushion material includes a first foamed resin provided on the front surface side of the elasticity applying member and the back surface of the elasticity applying member. And a second foamed resin provided on the side and having higher elasticity than the first foamed resin.

  In the seat pad according to claim 2, the first foamed resin having relatively low elasticity is provided on the passenger side of the elasticity applying member, and the second foamed resin having relatively high elasticity is provided on the passenger side. Since it is provided on the opposite side, it is possible to give a better seating feeling to the occupant side part than the elasticity applying member, and to hold the occupant more in the part on the back side than the elasticity applying member, It becomes possible to improve the stability of the sitting posture.

  According to a third aspect of the present invention, in the seat pad according to the first or second aspect, the cushion material is a seat cushion pad, and the elasticity imparting member is from a central portion in the front-rear direction of the seat cushion pad. Is also arranged closer to the rear.

  When the occupant is seated, the occupant's buttocks are positioned closer to the rear than the center portion in the front-rear direction of the seat cushion pad. For this reason, the elasticity imparting member can support the occupant's load under the occupant's buttocks, and the stability of the sitting posture can be easily improved.

  According to a fourth aspect of the present invention, in the seat pad according to the third aspect, the elasticity imparting member is larger than a bottom part of the occupant.

  By making the elasticity applying member larger than the lower part of the occupant's buttocks, the fit to the human body can be improved.

  According to a fifth aspect of the present invention, in the seat pad according to the first or second aspect, the cushion material is a seat back pad, and the elasticity imparting member is from a vertical center of the seat back pad. Is also arranged on the lower side.

  In the seat pad according to the fifth aspect, when the occupant is seated, the pelvis of the occupant is positioned below the center part in the vertical direction of the seat back pad. For this reason, the elasticity imparting member can support the load on the seat back pad side received from the pelvis of the occupant, and the stability of the sitting posture is easily improved.

  The invention according to claim 6 is the seat pad according to claim 5, wherein the elasticity imparting member is larger than a waist portion of the occupant.

  By making the elasticity imparting member larger than the occupant's waist, the fit to the human body can be improved.

  The invention according to claim 7 is the seat pad according to any one of claims 1 to 6, wherein the cushion material has a thickness of 45 to 60 mm.

  By making the thickness of the cushion material of the seat pad within the range of 45 to 60 mm, in a thin seat pad, it is possible to improve the fit of the human body and improve the stability of the sitting posture while suppressing the bottom butt feeling. it can.

  The invention according to claim 8 is the seat pad manufacturing method for manufacturing the seat pad according to any one of claims 1 to 7, wherein the elasticity applying member is arranged so that the elasticity applying member is separated from the mold. A step of supporting by a support member, a step of injecting a foamed resin material into the mold, and clamping the mold to foam-mold the seat pad; and opening the mold and opening the foam-molded seat pad. And removing the support member from the seat pad and removing the support member from the seat pad to demold the seat pad.

In the seat pad manufacturing method according to the eighth aspect, in the first step, the elastic member is supported by the support member so that the elastic member is separated from the mold. In other words, the elasticity imparting member is suspended in the mold so as not to contact the inner surface of the mold.
In the next step, a foamed resin material is injected into the mold, the mold is clamped, and the seat pad is foam-molded. Thereby, the whole elasticity provision member is covered with foaming resin, and it is embed | buried in foaming resin.
In the next step, the mold is opened and the foam-molded seat pad is removed to remove the support member from the seat pad, or the support member is removed from the seat pad to remove the seat pad. Thereby, the whole elasticity provision member is covered with foaming resin, and the seat pad embed | buried in foaming resin is obtained.

  The invention according to claim 9 is the seat pad manufacturing method for manufacturing the seat pad according to claim 8, wherein the seat pad includes side portions on both sides in the width direction of the occupant of the seat pad main body, and the foam The resin material forms a first foamed resin material injected between the elasticity applying member and the lower mold of the molding die, between the elasticity applying member and the upper mold of the molding die, and the side portion. And a second foamed resin material that molds a harder cushion material than the cushion material molded with the first foamed resin material.

In the seat pad manufacturing method according to claim 9, the first foamed resin material is injected between the elasticity applying member and the lower mold of the mold, and between the elasticity applying member and the upper mold of the mold, and on the side A second foamed resin material that molds a cushion material that is harder than the cushion material molded from the first foamed resin material is injected into the molded part that forms the part.
As a result, the cushion member formed of the first foamed resin material on the occupant side of the elasticity applying member, the side opposite to the passenger side of the elasticity applying member, and the cushion member formed of the first foamed resin material on the side portion are harder. A seat pad made of a cushion material formed of the second foamed resin material can be obtained.

  As described above, according to the seat cushion of the present invention, it is possible to achieve an excellent effect that it is possible to suppress the sense of incongruity, improve the fit of the human body, and improve the stability of the sitting posture while improving the feeling of bottoming. Have.

  In addition, according to the seat cushion manufacturing method of the present invention, it is possible to obtain a seat cushion that improves the feeling of bottoming while suppressing the sense of incongruity, improving the fit of the human body, and improving the stability of the sitting posture. It has an excellent effect.

It is a side view showing a vehicular seat using a seat pad concerning a 1st embodiment of the present invention. (A) is a top view which shows a seat cushion, (B) is a width direction cross section which shows the seat cushion shown to FIG. 2 (A), (C) is a width direction cross section which shows the seat cushion which the passenger | crew sat on. FIG. (A) is a front view showing a seat back, (B) is a width direction cross section showing the seat back shown in FIG. 3 (A), (C) is a width direction cross section showing a seat back on which an occupant is seated. FIG. (A) is the width direction sectional view which shows the shaping | molding die which shape | molds a seat cushion pad, (B) is the width direction sectional view which shows the lower mold | type which has arrange | positioned the 1st resin liquid, (C) is 1st. It is width direction sectional drawing which shows the lower mold | type which has arrange | positioned the resin liquid of this, the 2nd resin liquid, and the elasticity provision member. (A) is a sheet longitudinal cross-sectional view showing a lower mold in which the first resin liquid is arranged, and (B) is a lower mold in which the first resin liquid, the second resin liquid, and the elasticity imparting member are arranged. FIG. 2C is a cross-sectional view in the front-rear direction of the sheet, and (C) is a cross-sectional view in the front-rear direction of the sheet showing the mold in which the first resin liquid, the second resin liquid, and the elasticity imparting member are arranged. (A) is a top view which shows the seat cushion pad which supported the elasticity provision member with the seat fixing jig, (B) is sectional drawing which shows the elasticity provision member supported by the sheet fixing jig, (C) Is a plan view showing the seat cushion pad with the seat fixing jig pulled out, (D) is a cross-sectional view in the width direction showing the seat cushion pad with the seat fixing jig pulled out (6 (D)-in FIG. 6C). FIG. 6 (D) is a cross-sectional view). It is a seat front-back direction sectional view showing the lower model of the forming die used for the manufacturing method of the seat cushion pad concerning a 2nd embodiment. (A) is a top view which shows the lower mold | type of the shaping | molding die used for the manufacturing method of the seat cushion pad which concerns on 3rd Embodiment, (B) is seat front-back direction sectional drawing of the lower mold | type shown in FIG. 8 (A). It is. (A) is a width direction sectional view showing a seat cushion pad according to another embodiment, and (B) is a width direction sectional view showing a seat back pad according to another embodiment.

[First Embodiment]
A first embodiment of a seat pad according to the present invention will be described with reference to FIGS.
FIG. 1 shows a vehicle seat 16 including a seat cushion 12 and a seat back 14.
The seat cushion 12 includes a seat cushion pad 18 inside a skin (not shown). The seat cushion pad 18 includes a cushion material 20 made of foamed resin, which will be described later, and a planar elasticity applying member 22 made of an elastic material embedded in the cushion material 20.

  The seat back 14 includes a seat back pad 24 inside a skin (not shown). The seat back pad 24 includes a cushion material 26 and a planar elastic member 28 embedded in the cushion material 26. In other words, the cushion material 20 and the cushion material 26 are elastic members that have elasticity, are compressed when a load is applied, and return to the original shape by their own elasticity when the load is removed.

(Seat cushion pad)
As shown in FIGS. 2A and 2B, the seat cushion pad 18 has a seat pad body portion 29 at the center in the seat width direction, and both sides in the width direction of the seat pad body portion 29 are more than the seat pad body portion 29. The side portion 30 is formed so as to rise.

  The elasticity applying member 22 embedded in the seat cushion pad 18 is formed of a sheet-like member having a certain thickness. The elasticity applying member 22 has a rectangular shape when the seat cushion pad 18 is viewed from above, and extends in the seat width direction, in other words, from one side to the other side in the width direction of the occupant and in the seat front-rear direction. ing. The seat cushion pad 18 is viewed from the front-rear direction of the seat cushion pad 18, in other words, the seat cushion pad 18 is viewed from the cross section in the seat width direction, and the rear side of the seat cushion pad 18 is opposite to the passenger P side. For example, the seat cushion 12 is curved so as to be convex toward the lower side which is the back surface.

The elasticity applying member 22 may be curved with a single curvature, a form in which the curvature on the center side in the width direction is reduced and the curvature on both sides in the width direction is increased, and the curvature on the center side in the width direction is increased in the width direction. It may be curved with a plurality of large and small curvatures such as a form in which the curvatures on both sides are small.
The elasticity imparting member 22 may be inclined so that the seat front side is higher than the rear side when the seat cushion pad 18 is viewed from the lateral direction.
The sheet-like member used for the elasticity applying member 22 of the present embodiment is flat with a constant thickness before being curved, but a plurality of minute irregularities may be formed, and a plurality of minute holes are formed. May be.

  Further, both side portions in the width direction of the elasticity applying member 22 are jig insertion portions 32 rounded into a cylindrical shape. The jig insertion portion 32 is a portion into which a seat fixing jig 68 described later is inserted when the seat cushion pad 18 is formed. In addition, the cushion material 20 of the seat cushion pad 18 is formed with a hole 34 having a trace from which the seat fixing jig 68 is pulled out.

  The cushion material 20 of the seat cushion pad 18 of the present embodiment has a two-layer structure of a first foamed resin 36 and a second foamed resin 38. The cushion material 20 is formed of the first foamed resin 36 having low elasticity on the occupant P side of the elasticity applying member 22 in the seat pad main body 29, in other words, the seat surface side, and in other words, in other words, the elasticity applying member 22. The back side of the seat opposite to the occupant P side, both sides of the elasticity applying member 22 in the front-rear direction of the seat, and the side portions 30 are formed of a high-elasticity second foamed resin 38.

  The second foamed resin 38 is relatively more elastic than the first foamed resin 36. In other words, the second foamed resin 38 is relatively harder than the first foamed resin 36. Means. Further, “hard” means that the spring constant in the vertical direction is high, in other words, that the amount of compression when compressed by applying a load to the lower side in the vertical direction is small.

  As the first foamed resin 36 and the second foamed resin 38, for example, a flexible polyurethane foam can be used. A preferred embodiment of the flexible polyurethane foam is a flexible polyurethane foam obtained by foam-molding a foaming stock solution containing a polyol, a polyisocyanate, a crosslinking agent, a foaming agent, and a catalyst.

  The elasticity imparting member 22 can be formed of a synthetic resin, rubber, or the like having higher bending rigidity than the first foamed resin 36 and the second foamed resin 38, and the material used is not particularly limited. A material having good adhesion to the foamed resin 36 and the second foamed resin 38 is preferable. Note that high bending rigidity means that the bending spring constant is high.

As shown in FIGS. 1 and 2, the elasticity imparting member 22 is positioned below the buttocks of the occupant P seated on the vehicle seat 16 so as to support the load of the occupant P. In other words, the elasticity imparting member 22 is located at the center in the width direction of the seat cushion pad 18 and in the front-rear direction center of the occupant load support region of the seat cushion pad 18, in other words, behind the center position in the front-rear direction of the occupant load support region. Arranged on the side. In other words, the elasticity imparting member 22 is disposed in a region where the load of the passenger P is concentrated. The elasticity imparting member 22 of the present embodiment is formed to be larger than the bottom part (buttock) of the seated occupant P in plan view. In other words, the area of the elasticity imparting member 22 is larger than the area projected from the lower part of the bottom of the seated occupant P toward the seat cushion pad 18, and the dimension of the elasticity imparting member 22 in the seat width direction and the dimension of the seat longitudinal direction are as follows: Both are larger than the dimension in the width direction and the dimension in the front-rear direction of the seated occupant P.
Here, the occupant load support area is an area that can support the load of the occupant P, and means an area on the upper side of the seat cushion pad 18 that is in front of the area below the seat back 14 in the vertical direction. To do.
In addition, the size of the occupant P in the present embodiment is, for example, the same size as that of the three-dimensional sitting human model (3DM-JM 50) for measuring the vehicle interior dimensions. The width direction dimension of the buttocks of the three-dimensional sitting human body model for measuring the vehicle interior dimension is the width dimension at the position of BL ₁₂₀ in the plan diagram of FIG. 3 (seat pan diagram) of JIS D04607.
In the present embodiment, the sheet width direction dimension of the elasticity applying member 22 is set to 400 mm or more.

  The elasticity imparting member 22 is disposed in the middle portion of the cushion material 20 in the thickness direction, and the first foamed resin 36 and the second foamed resin are entirely disposed so as not to be exposed on the outer surface of the seat cushion pad 18. 38 completely covered.

  In the seat cushion pad 18, the thickness (average value) of the seat pad main body 29 of the cushion material 20 is preferably set within a range of 45 to 60 mm.

  Further, on the surface side of the seat cushion pad 18, a groove 40 extending along the seat front-rear direction is formed at a boundary portion between the seat pad main body portion 29 and the side portion 30, and the seat pad main body portion 29 is attached to the seat cushion pad 18. In the front-rear direction, three portions, in other words, a groove 42 and a groove 44 that are divided into a front portion 29A, an intermediate portion 29B, and a rear portion 29C are formed.

(Seat back pad)
As shown in FIGS. 3A and 3B, the seat back pad 24 has a seat pad body portion 25 at the center in the seat width direction, and both sides of the seat pad body portion 25 in the width direction are more than the seat pad body portion 25. The side portion 27 is formed so as to rise.

  The elasticity applying member 28 embedded in the seat back pad 24 is formed in a sheet shape having a constant thickness. The elasticity imparting member 28 has a rectangular shape when the seat back pad 24 is viewed in plan view, and the seat back pad 24 is viewed from above and below, in other words, when the seat back pad 24 is viewed in a cross section in the seat width direction, Is curved to be convex toward the opposite side, in other words, the rear side (the direction opposite to the direction of arrow F).

  Further, both side portions of the elasticity applying member 28 in the width direction are jig insertion portions 46 rounded into a cylindrical shape. The jig insertion portion 46 is a portion into which a seat fixing jig (not shown) similar to the seat fixing jig 68 used when molding the seat cushion pad 18 is inserted when the seat back pad 24 is molded. . Further, the cushion material 26 of the seat back pad 24 is formed with a hole 48 having a trace from which the seat fixing jig is pulled out.

  The cushion material 26 of the seat back pad 24 has a two-layer structure of a first foamed resin 50 and a second foamed resin 52. The seat cushion pad 18 has a low foamed first foamed resin 50 on the occupant side of the elasticity applying member 28 of the seat pad main body 25, in other words, the seat surface side, and in other words, the elasticity of the elasticity applying member 28. The seat back side opposite to the occupant side, both sides in the seat up-down direction of the elasticity applying member 28, and the side portions 27 serve as the second foamed resin 52. As the first foamed resin 50 and the second foamed resin 52, the same flexible polyurethane foam as that of the seat cushion pad 18 can be used.

  As the first foamed resin 50 and the second foamed resin 52, the same flexible polyurethane foam as that of the seat cushion pad 18 can be used. Further, the second foamed resin 52 is relatively more elastic than the first foamed resin 50. In other words, the second foamed resin 52 is relatively harder than the first foamed resin 50.

  The elasticity-imparting member 28 can be formed of a synthetic resin, rubber, or the like having a higher bending rigidity than the first foamed resin 50 and the second foamed resin 52, and the material used is not particularly limited. A material having good adhesion to the foamed resin 50 and the second foamed resin 52 is preferable.

The elasticity imparting member 28 is positioned behind the pelvis Pp of the occupant P when the occupant P is seated on the vehicle seat 16, and can mainly support a load directed toward the rear of the seat in the portion of the occupant P from the buttocks to the waist. The seat back pad 24 is disposed on the center side in the width direction and below the center portion in the vertical direction. The elasticity imparting member 28 of the present embodiment is formed larger than the waist of the occupant P when viewed from the front. In other words, the area of the elasticity applying member 28 is larger than the area projected from the waist of the occupant P toward the seat back pad 24, and the seat width direction dimension and the seat vertical dimension of the elasticity applying member 28 are both seated. It is larger than the width direction dimension and the vertical direction dimension of the waist of the occupant P.
The width direction dimension of the waist part of the three-dimensional sitting human body model for measuring the dimensions of an automobile interior is the width dimension at the position of HL ₂₀₅ in the front diagram of FIG. 2 (back pan diagram) of JIS D04607.
In the present embodiment, the sheet width direction dimension of the elasticity applying member 28 is set to 360 mm or more.

  The elasticity applying member 28 of the present embodiment is disposed in the middle portion of the seat back pad 24 in the thickness direction, and is entirely covered by the first foamed resin 50 and the second foamed resin 52. . For this reason, the elasticity imparting member 28 is not exposed on the outer surface of the seat back pad 24.

  A groove 54 extending along the seat vertical direction is formed on the front surface side of the seat back pad 24 at the boundary portion between the seat pad main body portion 25 and the side portion 27.

  Further, in the seat back pad 24, the thickness (average value) of the seat pad main body portion 25 of the cushion material 26 is preferably set within a range of 45 to 60 mm.

(Manufacturing method of seat cushion pad 18)
4 shows a longitudinal cross section of the mold 64 for molding the seat cushion pad 18, and FIG. 5 shows a longitudinal cross section along the center line of the mold 64 in the width direction. Yes.

  The molding die 64 includes an upper die 64A and a lower die 64B, and the upper die 64A can be moved in the vertical direction by a driving device (not shown). The upper mold 64A molds the upper surface side of the seat cushion pad 18, in other words, the front surface side, and the lower mold 64B molds the rear surface side of the seat cushion pad 18, in other words, the lower surface side.

  The lower mold 64B is formed with a cavity 56 that matches the shape of the surface side of the seat cushion pad 18, in other words, the seat pad main body portion 29 and the side portion 30, and the seat cushion pad 18 is formed on the bottom surface of the cavity 56. The protrusions 58, 60, and 62 for forming the groove 40, the groove 42, and the groove 44 are formed. Therefore, the bottom surface of the cavity 56 corresponds to the front region 56A corresponding to the front portion 29A of the seat cushion pad 18, the intermediate region 56B corresponding to the intermediate portion 29B, and the rear portion 29C by these protrusions 58, 60, and 62. The rear region 56 </ b> C is divided into a side region 30 </ b> A corresponding to the side portion 30.

  In addition, a pair of seat fixing jigs 68 is attached to the lower mold 64B at the end on the arrow F direction side (the seat front side as the seat cushion pad 18) so as to be bent. The sheet fixing jig 68 is formed of a wire material or the like, and can be disposed along the front-rear direction of the sheet so as to be placed on the top of the protrusion 62. The sheet fixing jig 68 can be inserted into and removed from the jig insertion portion 32 provided on both sides in the width direction of the elasticity applying member 22.

  The upper mold 64A is formed with a cavity 70 that matches the shape of the back side of the seat cushion pad 18.

(Forming seat cushion pads)
Next, the molding procedures (1) to (6) of the seat cushion pad 18 will be described.
(1) Stand the sheet fixing jig 68 (see FIG. 5A), insert the sheet fixing jig 68 into the jig insertion portion 32 of the elasticity applying member 22 (see FIG. 6B), and apply elasticity. The member 22 is held by the sheet fixing jig 68.

(2) As shown in FIG. 4 (B), the first resin liquid containing a foaming agent that will later become the first foamed resin 36 in the intermediate region 56B provided at the bottom of the cavity 56 of the lower mold 64B. (A foaming stock solution that becomes the first foamed resin 36 when foamed) 36A is disposed, and as shown in FIG. 5A, in the front region 56A, the rear region 56C, and the side region 30A (in FIG. 5A) A second resin liquid (foaming stock solution that becomes the second foamed resin 38 when foamed) 38A containing a foaming agent that will later become the second foamed resin 38 is arranged in a not-shown).

(3) Tilt the sheet fixing jig 68 and hold the elasticity applying member 22 in a suspended state so as not to contact the lower mold 64B.
(4) As shown in FIG. 4C, the second resin liquid 38 </ b> A is disposed on the elasticity applying member 22.

  The first resin liquid 36A disposed in the intermediate region 56B is surrounded by the ridges 58, the ridges 60, and the ridges 62, and the upper part is covered with the elasticity applying member 22. When the resin liquid 38A is disposed, it is possible to prevent the first resin liquid 36A and the second resin liquid 38A from being mixed.

(5) As shown in FIG. 5C, the mold 64 is closed, the first resin liquid 36A and the second resin liquid 38A are foamed and solidified in the mold 64, and the seat cushion pad 18 is molded. .

(6) After the first resin liquid 36A and the second resin liquid 38A are foamed and solidified, the mold 64 is opened, and the seat fixing jig 68 is pulled out from the seat cushion pad 18 (see FIG. 6A). ), The seat cushion pad 18 is taken out of the mold 64. As shown in FIGS. 6C and 6D, a hole 34 is formed in the cushion material 20 of the seat cushion pad 18 after the seat fixing jig 68 is pulled out. Alternatively, the seat fixing pad 68 may be pulled out after the seat cushion pad 18 is taken out of the mold 64.

  In addition, although illustration is abbreviate | omitted, the seat back pad 24 can also be shape | molded with a shaping | molding die (not shown) through the process similar to the seat cushion pad 18. FIG.

(Function, effect)
Next, the operation and effect of the seat cushion 12 of the present embodiment will be described.
When the occupant P sits on the vehicle seat 16, the load of the occupant P acts on the seat cushion pad 18, and the seat cushion pad 18 receives the load and is compressed and recessed, and curved so as to protrude toward the back side. The formed elasticity applying member 22 supports the load of the passenger P.

  The seat cushion pad 18 can suppress a bottom sensation because the elasticity imparting member 22 is embedded in the cushion material 20. Further, since the elasticity imparting member 22 is embedded in the cushion material 20 so as to be entirely surrounded by the cushion material 20 and is not exposed to the surface of the cushion material 20, the surface of the cushion material 20 is deformed when the elasticity imparting member 22 is deformed. Is difficult to be pulled, in other words, the cushion material 20 is not easily deformed locally, and the seated occupant P is unlikely to feel uncomfortable at the buttocks.

  The elasticity imparting member 22 has a planar shape with higher bending rigidity than the cushion material 20, is curved so that the center side in the width direction is convex toward the back surface side, and has a shape that follows the shape of the buttocks of the passenger P. Therefore, the seat cushion pad 18 according to the present embodiment can secure a deflection that fits the human body, and can improve the fit of the human body, as compared to the seat cushion pad using a flat elasticity imparting member. In addition, since the occupant P can be held by the elasticity applying member 22 that is curved when the lateral G is applied, the stability of the sitting posture can be improved. The elasticity applying member 22 is displaced and deformed together with the cushion material 20 with respect to the load of the occupant P, but is deformed in a shape along the shape of the buttocks of the occupant P, so that a feeling of holding is obtained.

  If a part of the elasticity applying member 22 is exposed to the outer surface of the seat cushion 12 and is in contact with a member disposed outside, the movement of the elasticity applying member 22 to be elastically deformed is restricted. Thus, the entire elasticity imparting member 22 that receives the load may not be deformed properly. However, as in the present embodiment, if the entire elasticity applying member 22 is surrounded by the cushion material 20, the movement of the elasticity applying member 22 is not restricted by the member disposed outside the seat cushion 12, It is possible to appropriately deform the entire elasticity applying member 22 that receives the load.

  Further, the seat cushion pad 18 is provided with elasticity because the first foamed resin 36 disposed on the upper side of the elasticity applying member 22 has low elasticity and the second foamed resin 38 disposed on the lower side is highly elastic. A better seating feeling can be imparted in the part on the occupant P side than the member 22, in other words, the feel when the occupant P is seated becomes softer, and the occupant P is more in the part on the back side than the elasticity imparting member 22. It is possible to hold it, and it is possible to suppress the bottom sensation and further improve the stability of the sitting posture. Furthermore, by making the thickness of the seat pad main body 29 of the cushion material 20 within a range of 45 to 60 mm, the thin seat cushion pad 18 can suppress the bottom butt feeling and enhance the posture retention of the occupant P. be able to.

  The side portions 30 disposed on both sides of the seat pad main body 29 in the seat width direction can support the seated occupant P's buttocks from the side, so that the lateral movement of the occupant P is suppressed in cornering and the like. Steering stability can be improved.

  In addition, since the hole 34 is formed in the cushion material 20 of the seat cushion pad 18, the air permeability of the cushion material 20 can be improved.

Next, functions and effects of the seat back pad 24 will be described.
When the occupant P is seated on the vehicle seat 16 and the load of the occupant P acts on the seat back pad 24, the seat back pad 24 is compressed and recessed, and is elastically curved so as to be convex toward the back side. The applying member 28 can be deformed to support the load of the passenger P.

  The seat back pad 24 of the present embodiment is compared with a case where a flat elasticity-imparting member is deformed by deforming the elasticity-imparting member 28 curved so as to be convex toward the back surface side as described above. Thus, it is possible to improve the human body fit and the stability of the sitting posture. Further, the elasticity applying member 28 is displaced and deformed together with the cushion material 26 with respect to the load of the occupant P, but is deformed in a shape along the shape of the occupant P, so that a hold feeling is obtained. Further, since the entire elasticity applying member 28 is surrounded by the cushion material 26, the elasticity applying member 28 is displaced and deformed together with the cushion material 26 with respect to the load of the occupant P, and a hold feeling can be obtained without a sense of incongruity.

  Further, the seat back pad 24 has a low elasticity of the first foamed resin 50 disposed on the occupant P side of the elasticity applying member 28 and a high second foamed resin 52 disposed on the side opposite to the occupant P side. Since it is elastic, a better seating feeling can be imparted at the portion closer to the occupant P than the elasticity imparting member 28, in other words, the feel when the occupant P is seated becomes softer, and the back side more than the elasticity imparting member 28 It is possible to hold the occupant P more in this portion, to suppress the bottom sensation, and to further improve the stability of the sitting posture. Further, by setting the thickness of the seat pad main body portion 25 of the cushion material 26 within the range of 40 to 60 mm, in the thin seat back pad 24, it is possible to improve the maintainability of the posture of the occupant P while suppressing the feeling of bottoming. be able to.

  The side portions 27 arranged on both sides of the seat pad main body portion 25 in the seat width direction can support the seated occupant P from the side portion. Can be improved.

  In addition, since the hole 48 is formed in the cushion material 26 of the seat back pad 24, the air permeability of the cushion material 26 can be improved.

[Second Embodiment]
In the second embodiment, a manufacturing method of the seat cushion pad 18 different from the first embodiment will be described. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.
As shown in FIG. 7, in the manufacturing method of the present embodiment, the lower mold 64B of the mold 64 is inclined so that the arrow F direction side is the upper side, and is used in the lower mold 64B of the first embodiment. Instead of the sheet fixing jig 68, a pin 72 is provided in the middle region 56B of the cavity 56 to support the elasticity applying member 22 in a suspended state. Other configurations are the same as those in the first embodiment.

  In the present embodiment, the elasticity applying member 22 is first mounted on and supported by the pin 72, and then the intermediate region 56B on the arrow F direction side of the elasticity applying member 22 (a portion not hidden by the elasticity applying member 22 in plan view). By injecting the first resin liquid 36A from above, the first resin liquid 36A is injected downward on the inclined intermediate region 56B to the lower side of the elasticity applying member 22. Can be arranged. In the present embodiment, first, the first resin liquid 36A may be injected and arranged in the intermediate region 56B, and then the elasticity applying member 22 may be placed on and supported by the pin 72.

  Thus, by using the molding die 64 of the present embodiment, it is possible to eliminate the restriction on the arrangement order between the arrangement of the elasticity applying member 22 and the arrangement of the second resin liquid 38A. Further, in the present embodiment, there is no need to step down the sheet fixing jig 68 or pull out the sheet fixing jig 68 after the first resin liquid 36A is disposed.

[Third Embodiment]
In the third embodiment, a manufacturing method of the seat cushion pad 18 different from the first embodiment and the second embodiment will be described. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.
As shown in FIG. 8A, in the manufacturing method of the present embodiment, a hole 74 is formed at the center of the elasticity applying member 22.

  Therefore, in the present embodiment, the elasticity applying member 22 is first placed on and supported by the pin 72, and then the first resin liquid 36A is injected into the lower intermediate region 56B through the hole 74. can do. In the present embodiment, first, the first resin liquid 36A may be injected and arranged in the intermediate region 56B, and then the elasticity applying member 22 may be placed on and supported by the pins 72. Therefore, this embodiment can also eliminate the restriction of the arrangement order of the arrangement of the elasticity applying member 22 and the arrangement of the first resin liquid 36A.

As the first foamed resin and the second foamed resin in the embodiment, for example, the flexible polyurethane foam described below can be used.
Below, an example of a flexible polyurethane foam and its manufacturing method is demonstrated.
A preferred embodiment of the flexible polyurethane foam is a flexible polyurethane foam obtained by foam-molding a foaming stock solution containing a polyol, a polyisocyanate, a crosslinking agent, a foaming agent, and a catalyst. The following (A)-(C) are mentioned as a characteristic of the more suitable material which comprises the said foaming undiluted | stock solution.

(A) As a polyol component, the polyether polyol whose weight average molecular weight Mw is 3000-12000 and whose functional group number (number of hydroxyl groups) is 3-4 is contained. (B) The ethylene oxide group / propylene oxide group (molar ratio) in the entire compound (total cross-linking agent) contained in the foaming stock solution as the cross-linking agent component is 100 or more.
(C) As a polyisocyanate, 70 or more diphenylmethane diisocyanate (MDI) is contained by an isocyanate equivalent.

<Polyol component>
As a polyol component constituting the foaming stock solution, a polyether polyol having a weight average molecular weight Mw of 3,000 to 12,000 and a functional group number (number of hydroxyl groups) of 3 to 4 is contained. The polyether polyol is preferably a polyether polyol obtained by ring-opening polymerization of an alkylene oxide because of good reactivity. Examples of the alkylene oxide include propylene oxide (PO) and ethylene oxide (EO). The alkylene oxide used as the material for the polyether polyol may be one kind or two or more kinds.

  The polyether polyol constituting the foaming stock solution is preferably a polyether polyol obtained by using the above PO and EO together from the viewpoint of raw material activity. The blending ratio (molar ratio) of PO and EO is not particularly limited. For example, the EO / PO (molar ratio) is preferably 8/92 to 25/75, and more preferably 13/87 to 20/80. When the EO / PO (molar ratio) is in the above range, a polyether polyol having good reactivity can be easily produced.

  The number of hydroxyl groups (functional groups) contained in one molecule of the polyether polyol constituting the foaming stock solution is preferably 3 to 4. Within these preferred ranges, the viscosity of the foamed stock solution becomes moderate, and a flexible polyurethane foam having excellent physical properties can be obtained. As an optional component, in addition to the polyether polyol of (A), a polyether polyol having two functional groups may be used in combination.

  The weight average molecular weight Mw of the polyether polyol constituting the foaming stock solution is preferably 3,000 to 12,000, more preferably 3,000 to 8,000, and further preferably 5,000 to 8,000. When the weight average molecular weight of the polyether polyol is 12,000 or less, the viscosity of the foaming stock solution is not excessively increased, and the stirring efficiency is improved. On the other hand, if the weight average molecular weight of the polyether polyol is 3,000 or more, a flexible polyurethane foam having good rebound resilience can be obtained. Here, the weight average molecular weight Mw is a value calculated as a polystyrene conversion value by gel permeation chromatography (GPC method).

  The degree of unsaturation of the polyether polyol constituting the foaming stock solution is preferably 0.03 meq / g or less. When the degree of unsaturation is 0.03 meq / g or less, a flexible polyurethane foam having good physical properties such as durability can be obtained. Here, “the degree of unsaturation” was measured by a method in which acetic acid liberated by acting mercuric acetate on unsaturated bonds in a sample was titrated with potassium hydroxide in accordance with JIS K 1557-1970. , Meaning total unsaturation (milli equivalent / g).

  The polyether polyol contained in the foaming stock solution as the polyol component may be one type or two or more types.

  When there is only one kind of polyether polyol contained in the foaming stock solution as the polyol component, a polyether polyol having a weight average molecular weight of 7000 or more and 4 functional groups (tetrafunctional) is contained. It is preferable. When the polyether polyol is used, the feeling of wobbling when the flexible polyurethane foam obtained by foam molding is used as a pad for a sheet can be greatly reduced, and steering stability can be improved.

  From the viewpoint of easily imparting desired physical properties to a flexible polyurethane foam obtained by foam-molding the foamed stock solution, one type corresponding to the polyether polyol of (A) with respect to the total mass of the polyol component contained in the foamed stock solution Alternatively, the total content of two or more kinds of polyether polyols is preferably 60% by mass or more, more preferably 70 to 100% by mass, further preferably 80 to 100% by mass, and most preferably 85 to 100% by mass.

  In addition to the polyether polyol, a polymer polyol may be used in combination as the polyol component constituting the foaming stock solution. As the polymer polyol, a polymer polyol widely used for polyurethane foam moldings can be applied. For example, a polymer component such as polyacrylonitrile or acrylonitrile-styrene copolymer is added to a polyether polyol made of polyalkylene oxide and having a weight average molecular weight Mw of 3,000 to 8,000, more preferably 4,000 to 7,000. Examples include graft-polymerized polymer polyols. The alkylene oxide used as the raw material of the polyalkylene oxide is preferably an alkylene oxide containing propylene oxide (PO) as a functional group (polymerizable group), an alkylene oxide containing only propylene oxide, or propylene oxide and ethylene oxide (EO). More preferred are alkylene oxides included together. Moreover, it is preferable that content of the said polymer component with respect to the total mass of the said polymer polyol is 25-50 mass%.

As a polyol component which comprises the said foaming undiluted | stock solution, only polyether polyol may be used and the mixture of polyether polyol and polymer polyol may be used.
As a mixing ratio in the case of using a mixture of a polyether polyol and a polymer polyol, it is sufficient that the polyether polyol is less than 100% and the polymer polyol is more than 0%, and the polyether polyol / polymer polyol (mass ratio) is 70 / 30-99 / 1 is preferable, 80 / 20-99 / 1 is more preferable, and 85 / 15-99 / 1 is still more preferable. When the mixture is used and the mixing ratio is in the above range, a flexible polyurethane foam having desired physical properties is easily obtained.

<Polyisocyanate component>
As a polyisocyanate component constituting the foaming stock solution, 70 or more diphenylmethane diisocyanate is contained in an isocyanate equivalent.

Diphenylmethane diisocyanate (MDI) is a polyisocyanate component commonly used in the field of polyurethane foam. Specific examples of MDI include 4,4-diphenylmethane diisocyanate (4,4-MDI), generally called monomeric MDI, 2,
Examples include 4-diphenylmethane diisocyanate (2,4-MDI), 2,2-diphenylmethane diisocyanate (2,2-MDI), polymeric MDI, and crude MDI.
In the foaming stock solution, one type of MDI may be contained alone, or two or more types of MDI may be contained.

  “Isocyanate equivalent” representing the total amount of polyisocyanate contained in the foaming stock solution means the molar ratio of isocyanate groups when the amount of active hydrogen (mole) in the foaming stock solution is 100.

  The isocyanate equivalent derived from MDI contained in the foaming stock solution is at least 70 or more, preferably 70 to 120, and more preferably 80 to 100. When the isocyanate equivalent is 70 or more, poor stirring of the foaming stock solution can be prevented. Generation | occurrence | production of foam collapse can be prevented as the said isocyanate equivalent is 120 or less.

  As an optional component, a small amount of a known polyisocyanate component other than MDI may be added in addition to the MDI of (C). For example, tolylene diisocyanate (TDI), triphenyl diisocyanate, xylene diisocyanate, polymethylene polyphenylene polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and the like can be mentioned.

  From the viewpoint of easily imparting desired physical properties to the flexible polyurethane foam formed by foaming the foaming stock solution, one type or two of diphenylmethane diisocyanate (C) with respect to the total mass of the polyisocyanate component contained in the foaming stock solution The total content of at least types is preferably 70% by mass or more, more preferably 80 to 100% by mass, further preferably 90 to 100% by mass, and most preferably 95 to 100% by mass.

  Further, the content of pure MDI constituting the diphenylmethane diisocyanate (C) with respect to the total mass of the polyisocyanate component contained in the foaming stock solution is preferably 40% by mass or more, more preferably 50 to 90% by mass, 55 -85 mass% is further more preferable, and 60-80 mass% is the most preferable.

<Crosslinking agent component>
Since the flexible polyurethane foam obtained by foam-molding the foamed stock solution has desired physical properties, as a cross-linking agent component constituting the foamed stock solution, a cross-linking agent having a higher reactivity with respect to the polyisocyanate component than water is a main component. Is preferably included. Usually, the reactivity with respect to the polyisocyanate component decreases in the order of glycerin, a crosslinking agent having an ethylene oxide group (EO-based crosslinking agent), water, and a crosslinking agent having a propylene oxide group (PO-based crosslinking agent). Based on this, the molar ratio of the EO group to the PO group (the number of moles of EO groups / the number of moles of PO groups) of one or more compounds contained as a cross-linking agent in the foaming stock solution is 100. It is preferably above, more preferably 105 or more, and even more preferably 110 or more. A higher molar ratio is preferable. That is, it is preferable that the foaming stock solution does not substantially contain a crosslinking agent having a PO group.

  Here, the ethylene oxide group (EO group) means a group having a monovalent bond from which one hydrogen atom constituting ethylene oxide is removed. The propylene oxide group (PO group) means a group having a monovalent bond in which one hydrogen atom constituting propylene oxide is removed.

  As a specific crosslinking agent component, a known crosslinking agent used in the field of polyurethane foam can be applied. The molecular weight of the crosslinking agent is usually preferably 1000 or less. From the viewpoint of increasing the molar ratio of the EO group / PO group, a commercially available cross-linking agent indicated as “EO (group) / PO (group) = 100/0” is preferable.

  The crosslinking agent contained in the foaming stock solution may be one type or two or more types.

  The total content of the cross-linking agent components contained in the foaming stock solution is preferably 0.5 to 10 parts by mass and more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the polyol component. . When the amount is not more than the upper limit of the above range, the closed cell property becomes too high, molding becomes difficult, and foam collapse can be prevented. The effect of a crosslinking agent is fully acquired as it is more than the lower limit of the said range.

<Foaming agent component>
As a foaming agent component constituting the foaming stock solution, it is preferable to use water. Since water reacts with polyisocyanate to generate carbon dioxide, it functions as a foaming agent.
As content of the water in the said foaming undiluted | stock solution, it is preferable that it is 1-7 mass parts with respect to 100 mass parts of polyol components, and it is more preferable that it is 2-5 mass parts. Within the above range, a flexible polyurethane foam having desired physical properties can be easily obtained. Moreover, it can prevent that the heat compression residual distortion characteristic of the obtained flexible polyurethane foam deteriorates.

<Catalyst component>
Examples of the catalyst component that constitutes the foaming stock solution include known catalysts used in the field of polyurethane foam. Known catalysts include amine catalysts and tin catalysts.

In general, known catalysts are roughly classified into a resination catalyst that promotes the resinization of polyurethane and a foaming catalyst that promotes foaming of the polyisocyanate component.
Suitable resination catalysts are tertiary amine catalysts that specifically promote the reaction of polyisocyanates and polyols, such as, but not limited to, triethylenediamine, 1,8-diazabicyclo [5.4.0]. Undecene-7, imidazoles such as 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1,1 ′-(3- (dimethylamino) propyl) imino) bis (2- Propanol). A suitable foaming catalyst is a tertiary amine catalyst that particularly accelerates the reaction between isocyanate and water and effectively generates carbon dioxide, and is generally used for improving the fluidity and dimensional stability of the foam. The foaming catalyst is not particularly limited, but bis (2-dimethylaminoethyl) ether, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, and N, N, N ′, N ″. , N ′ ″, N ′ ″-hexamethyltriethylenetetramine and the like.

The foaming stock solution preferably contains at least a resination catalyst as a catalyst component among a resination catalyst and a foaming catalyst.
The mass ratio of the resinification catalyst: foaming catalyst contained in the foaming stock solution is preferably 100: 0 to 100: 100, more preferably 100: 0 to 100: 50, and further more preferably 100: 0 to 100: 20. preferable.

The amine-based catalyst has a ratio of the foaming catalyst constant to the gelation catalyst constant of 10 × 10 in order to accelerate the resinification (gelation) reaction between polyols and polyisocyanates and promote urethane bond formation. It is preferable to use a resinification catalyst that is ⁻¹ or less.
Here, the gelation catalyst constant is a constant that determines the speed of the resinification reaction between polyols and polyisocyanates. As the value increases, the crosslink density of the foam increases and the mechanical properties of the foam increase. Become good. Specifically, the reaction constant of the gelation reaction between tolylene diisocyanate and diethylene glycol is used. On the other hand, the foaming catalyst constant is a constant that determines the speed of the foaming reaction between the polyisocyanates and water, and the larger the value, the higher the cell connectivity of the foam. Specifically, the reaction constant of the foaming reaction between tolylene diisocyanate and water is used. The ratio of the two catalyst constants represents the balance of both catalysts.
Examples of suitable amine-based catalysts are exemplified below including specific examples of the resinification catalyst.

Specific examples of the resinification catalyst include the above-mentioned catalyst, triethylenediamine (TEDA), a mixture of triethylenediamine and polypropylene glycol, N, N, N ′, N
'-Tetramethylethylenediamine, N, N, N', N'-tetramethylpropylenediamine, N, N, N ', N ", N" -pentamethyl- (3-aminopropyl) ethylenediamine, N, N, N' , N ″, N ″ -pentamethyldipropylenetriamine, N, N, N ′, N′-tetramethylguanidine, 135-tris (N, N-dimethylaminopropyl) hexahydro-S-triazine Imidazoles such as 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, other N, N, N ′, N′-tetramethylhexamethylenediamine, N-methyl-N′- (2-dimethylaminoethyl) piperazine, N, N'-dimethylpiperazine, N-methylpiperazine, N-
Examples include methylmorpholine and N-ethylmorpholine.

  The content of the amine-based catalyst in the foaming stock solution is preferably 0.1 to 0.4 parts by mass, and 0.2 to 0.4 parts by mass with respect to 100 parts by mass of the polyol component. Is more preferably 0.3 to 0.4 parts by mass. When the lower limit of the above range is 0.1 parts by mass or more, foam collapse can be prevented. When the upper limit of the above range is 0.4 parts by mass or less, it is possible to prevent shrinkage from occurring due to closed cells.

  Specific examples of the tin catalyst include known organotin catalysts such as stannous octoate, stannous laurate, dibutyltin dilaurate, dibutyltin dimaleate, dibutyltin diacetate, dioctyltin diacetate, and tin octylate.

  The content of the tin catalyst in the foaming stock solution is preferably 0.01 to 0.5 parts by mass, and 0.01 to 0.4 parts by mass with respect to 100 parts by mass of the polyol component. More preferred is 0.01 to 0.2 parts by mass.

<Foam stabilizer component>
The foaming stock solution may contain a foam stabilizer. As the foam stabilizer, known foam stabilizers used in the field of polyurethane foam are applicable, and examples thereof include silicone foam stabilizers, anionic foam stabilizers, and cationic foam stabilizers. These foam stabilizers include foam stabilizers having a hydroxyl group at the molecular chain terminal.

  As for content of the foam stabilizer in the said foaming undiluted | stock solution, 0.1-5 mass parts is preferable with respect to 100 mass parts of said polyol components, 0.2-3 mass parts is more preferable, 0.3-0.8 Part by mass is more preferable. Usually, the effect as a foam stabilizer is sufficiently obtained at a content of 5 parts by mass or less. Moreover, the stirring rate of a polyol component and a polyisocyanate component improves that it is a content rate of 0.1 mass part or more, and the flexible polyurethane foam which has a desired physical property is easy to be obtained.

<Other optional components>
Various additives may be added to the foaming stock solution as necessary. For example, coloring agents such as pigments, chain extenders, fillers such as calcium carbonate, flame retardants, antioxidants, UV absorbers, light stabilizers, conductive materials such as carbon black, antibacterial agents, etc. it can. The compounding quantity of various additives is suitably adjusted according to a use and the objective.

<Method for preparing foaming stock solution>
The method for preparing the foaming stock solution is not particularly limited. For example, a mixture composed of the remaining components excluding the polyisocyanate component (hereinafter sometimes abbreviated as “polyol mixture”) is prepared, and then. The preparation method which mixes with a polyisocyanate component and obtains foaming stock solution is mentioned.

The polyol mixture is prepared by first mixing the catalyst component with the polyol component in order to reduce the contact between the foaming agent water and the catalyst component, then the foam stabilizer component, the crosslinker component, and if necessary. Accordingly, it is preferable to mix optional components and finally mix water as a blowing agent.
Thereafter, in the step of foam-molding the flexible polyurethane foam, it is preferable to prepare the foaming stock solution by mixing the polyol mixture and the polyisocyanate component.

  The viscosity of the prepared polyol mixture at a liquid temperature of 25 ° C. is preferably 2,400 mPa · s or less, and more preferably 1,800 mPa · s or less. When the viscosity is within such a suitable range, the stirring efficiency of the foaming stock solution is improved, and a sufficient amount of foaming is obtained uniformly throughout the foaming stock solution, thereby obtaining a flexible polyurethane foam (foamed molded product) having desired physical properties. It becomes easy to be done.

  A method for foam-molding a flexible polyurethane foam using the foaming stock solution is not particularly limited. For example, a known method for foaming by injecting a foaming stock solution into a cavity formed in a mold can be applied. .

  In the above known method, in order to prevent separation of each component constituting the foaming stock solution, it is preferable to prepare the foaming stock solution by mixing the above-mentioned components immediately before injecting the foaming stock solution into the cavity. The liquid temperature of the foaming stock solution to be injected is preferably 10 to 50 ° C, more preferably 20 to 40 ° C, still more preferably 25 to 35 ° C. The temperature of the mold is preferably 40 to 80 ° C, more preferably 50 to 70 ° C, and still more preferably 60 to 65 ° C. When the liquid temperature of the foaming stock solution and the temperature of the mold are within the above-mentioned preferable ranges, appropriate foaming can be obtained. Subsequent to foaming, the target flexible polyurethane foam is obtained by curing in a mold and then demolding. The flexible polyurethane foam obtained here may be further subjected to a known foam breaking treatment.

<Rigidity distribution in the thickness direction of flexible polyurethane foam>
Regardless of the foam molding method, the flexible polyurethane foam according to the present invention gradually increases in rigidity (hardness) in the thickness direction from the lower layer to the upper layer during foam molding (that is, the upward direction along the vertical line). There is a tendency. That is, the rigidity distribution in the thickness direction of the flexible polyurethane foam according to the present invention shows a continuous increasing tendency or a decreasing tendency. Here, the rigidity distribution tends to increase when viewed from the lower layer to the upper layer during foam molding of flexible polyurethane foam, but when the same flexible polyurethane foam is viewed from the upper layer to the lower layer during foam molding, the rigidity distribution The distribution shows a decreasing trend.

  Although the details of the mechanism by which the flexible polyurethane foam according to the present invention exhibits the above-described rigidity distribution are unknown, it is considered that the combination of the respective components constituting the foaming stock solution is a factor. In particular, the main polymerizable group (reactive group) of the crosslinker component is an EO group, and the PO group that does not substantially exhibit a crosslinking effect is not included in the crosslinker component, and polyisocyanate It is considered that a large factor is that MDI is contained as a major part of the component and that TDI is little or not contained. Moreover, it is considered that the fact that glycerin is contained as a cross-linking agent component and that a resinification catalyst is contained as a catalyst component contributes to the above-described rigidity distribution.

  In addition, when the flexible polyurethane foam exhibiting the above stiffness distribution is cut in the thickness direction, the degree of flatness of the foamed cell shape appearing in the cross section tends to gradually increase from the upper layer to the lower layer during foam molding. It is done. In other words, in the flexible polyurethane foam obtained by foam molding, the foam cell located in the lower layer at the time of foam molding is crushed in the direction of gravity and exhibits a horizontally long flat shape (elliptical shape), and the foam cell located in the middle layer The degree of flatness is relatively relaxed and approaches a circle, and the degree of flatness in the foam cell located in the upper layer is further relaxed and tends to be closer to a circle. Thus, it is thought that the change in the shape of the foamed cell that appears in the cross section in the thickness direction of the flexible polyurethane foam correlates with the tendency of the stiffness distribution.

  Note that “soft” of the flexible polyurethane foam means that the flexible polyurethane foam has a hardness (rigidity) enough to be deformed and recessed when the soft polyurethane foam is pushed by hand or sitting on it.

  The foaming stock solution forming the flexible polyurethane foam has a novel composition. As a result, comfortable sitting comfort and stability different from conventional ones, in other words, steering stability, can be obtained by reducing the wobble feeling when an appropriate repulsive force at the time of sitting and lateral acceleration is applied.

Examples will be described below, but the present invention is not limited to these examples.
Manufacturing the seat pad of Examples 1 and 2 provided with the elasticity imparting member and the seat pad of Comparative Example 1 not equipped with the elasticity imparting member, steering stability (feeling of wobbling when lateral G is added), The ride comfort (vertical vibration absorption) and bottom sensation were compared.
The structure of the seat pad is that of the first embodiment.
A resin foam stock solution was prepared with the formulation shown in Table 1, and this stock solution was poured into a mold and subjected to foam molding to obtain a seat pad body portion made of material A or B.

“Polyether polyol A1-2” has an EO / PO molar ratio of 13/87, a number average weight average molecular weight of 7000, and a functional group number of 3.
“Polymer polyol A2-1” is a polymer polyol having a solid content of 33%, a hydroxyl value of 23 mgKOH / g, a weight average molecular weight of 5400, and a 3.2 functional polymer (manufactured by Sanyo Chemical Industries, Ltd., trade name: KC855).
“Crosslinking agent C-1” has an EO / PO molar ratio of 100/0, a weight average molecular weight of 400, and a functional group number of 4.
"Catalyst D-1" is a commercially available resinification catalyst and is triethylenediamine.
“Catalyst D-2” is a commercially available foaming catalyst and is (2-dimethylaminoethyl) ether.
“Foam stabilizer E-1” is a silicone foam stabilizer (trade name: B8742) manufactured by Evonik.
“Foaming agent F-1” is water.
“Polyisocyanate (B-1)” is an MDI isocyanate called “NE150” manufactured by DOW. TDI-based isocyanate is not substantially contained.
“Polyisocyanate (B-2)” is a commercially available polyisocyanate, which is a TDI-based isocyanate mixed at TDI / MDI = 80/20 (mass ratio).

  Riding comfort, handling stability, bottom-bottom feeling, and human body fit feeling were sensory evaluated by a test driver running a test course on a vehicle equipped with a prototype seat. The evaluation of ride comfort, handling stability, feeling of bottoming, and human body fit is a three-stage evaluation of A, B, and C. A is the best, and the performance decreases in the order of B and C. I mean.

As a result of the test, Examples 1 and 2 provided with the elasticity imparting member have improved handling stability, riding comfort, bottom-up feeling, and human fit feeling as compared with Comparative Example 1 not provided with the elasticity imparting member. I found out.
In addition, Example 1 molded using the material A has further improved handling stability, ride comfort, bottom-up feeling, and human fit than Example 2 molded using the material B. I understood.
Furthermore, since the material itself becomes harder from the seating surface to the back surface by using the material of Example 1, in addition, since the hardness can be adjusted by the elasticity imparting member, more ride comfort, handling stability, bottom sensation, And a human body fit feeling can be improved.
On the other hand, the material B of Comparative Example 1 has the softest part in the layer between the seating surface and the back surface. With this configuration, when a lateral G is added, a soft polyurethane foam feels lying in the middle layer deeper than the surface layer close to the seating surface, and a wobble feeling is likely to occur. For this reason, it has been found that the ride comfort, the handling stability, the bottom thrust and the human body fit are insufficient.

[Other Embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and other various modifications can be made without departing from the spirit of the present invention. It is.

  In the first embodiment, the cushion material 20 of the seat cushion pad 18 and the cushion material 26 of the seat back pad 24 are each formed of two types of foamed resins having different hardnesses. As shown in B), the cushion material 20 of the seat cushion pad 18 and the cushion material 26 of the seat back pad 24 can be formed of one type of foamed resin.

In the above embodiment, the elasticity-imparting member 22 and the elasticity-imparting member 28 are in the form of a sheet having a constant thickness. However, the thickness in the width direction center is thick and the both sides in the width direction are thin. The thickness may be partially different, such as a form that is thin and thick on both sides in the width direction.
Both end portions of the elasticity applying member 22 may extend into the side portion 30. Similarly, both end portions of the elasticity applying member 28 may extend into the side portion 27.

  In the above-described embodiment, the elasticity applying member 22 is located at the center side in the width direction of the seat cushion pad 18 and in the front-rear direction center portion of the occupant load support region of the seat cushion pad 18, in other words, from the center position in the front-rear direction of the occupant load support region. Although it has been arranged closer to the rear, it may be arranged to extend further forward than the center position in the front-rear direction.

  In the above-described embodiment, the elasticity applying member 28 is disposed on the center side in the width direction of the seat back pad 24 and closer to the lower side than the center portion in the vertical direction, but is disposed so as to extend upward from the center portion in the vertical direction. May be.

  In the said embodiment, although the thickness (average value) of the cushioning material 20 was 45-60 mm, you may make it thickness other than 45-60 mm. The thickness of the cushion material 26 is also the same.

DESCRIPTION OF SYMBOLS 18 ... Seat cushion pad (seat pad), 20 ... Cushion material, 24 ... Seat back pad (seat pad), 26 ... Cushion material, 22 ... Elasticity imparting member, 27 ... Side part, 28 ... Elasticity imparting member, 30 ... Side Part 36 ... first foamed resin 36A ... first resin liquid (first foamed resin material) 38 ... second foamed resin 38A ... second resin liquid (second foamed resin material) 64 ... Molding die, 64A ... upper die, 68 ... sheet fixing jig (support member)

Claims (9)

A cushioning material made of foamed resin that supports the load of the occupant;
Surrounded entirely by the cushion material, embedded in the cushion material, and curved and formed so that the center side in the width direction of the occupant is convex toward the back surface opposite to the occupant side surface, Also has a high bending rigidity, and a surface-like elasticity imparting member extending from one side in the width direction of the occupant to the other side;
Having a seat pad.   The cushion material includes a first foamed resin provided on the front surface side of the elasticity applying member and a second foam resin provided on the back side of the elasticity providing member and having higher elasticity than the first foamed resin. The seat pad according to claim 1, comprising: The cushion material is a seat cushion pad,
The seat pad according to claim 1 or 2, wherein the elasticity applying member is disposed closer to the rear than a center portion in the front-rear direction of the seat cushion pad.   The seat pad according to claim 3, wherein the elasticity imparting member is larger than a bottom part of the occupant. The cushion material is a seat back pad,
The seat pad according to claim 1 or 2, wherein the elasticity applying member is disposed closer to the lower side than a central portion in the vertical direction of the seat back pad.   The seat pad according to claim 5, wherein the elasticity applying member is larger than a waist portion of the occupant.     The seat pad according to any one of claims 1 to 6, wherein the cushion material has a thickness of 45 to 60 mm. A step of supporting the elasticity applying member with a support member so that the elasticity applying member is separated from the mold;
Injecting a foamed resin material into the mold, clamping the mold, and foam-molding the seat pad;
Opening the molding die and removing the foam-molded seat pad to remove the support member from the seat pad; or removing the support member from the seat pad to remove the seat pad; ,
The manufacturing method of the seat pad which manufactures the seat pad of any one of Claims 1-7 which has these. The seat pad includes side portions on both sides in the width direction of the occupant of the seat pad main body,
The foamed resin material includes a first foamed resin material injected between the elasticity applying member and the lower mold of the molding die, between the elasticity applying member and the upper mold of the molding die, and the side portion. 9. The seat pad according to claim 8, wherein the seat pad is divided into a second foamed resin material that molds a cushion material harder than a cushion material molded by the first foamed resin material and injected into a molding part that forms a material. A method for manufacturing a seat pad.