JP2017070633A - Seat pad for vehicle and seat for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve weight reduction while favorably securing a riding comfort of a seated person, a feeling at a seating initial stage and the quality of external appearance.SOLUTION: In a seat cushion pad 20, since a layer at which a large number of lightening holes 26 are formed is a lower layer part 24 out of an upper layer part 22 and the lower layer part 24 which are composed of foaming bodies, a feeling at a seating initial stage and the quality of external appearance can be favorably secured by the upper layer part 22. Furthermore, since the lower layer part 24 is formed of the foaming body which is higher in hardness than the foaming body which constitutes the upper layer part 22, load deflection curved lines of the upper layer part 22 and the lower layer part 24 can be made coincident with or approximate to each other by setting dimensions and the number and arrangement of a large number of the lightening holes 26. As a result, since a hysteresis loss can be reduced, a riding comfort of a seated person can be favorably secured. Furthermore, since both the upper layer part 22 and the lower layer part 24 are formed of the foaming bodies, and a large number of the lightening holes 26 are formed at the lower layer part 24, weight reduction is achieved.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle seat pad and a vehicle seat.

  In the vehicle seat pad described in Patent Literature 1 described below, a large number of concave holes are provided in the upper surfaces of the lower thigh, lower buttocks, and side portions to reduce the weight.

  In the seat sheet described in Patent Document 2 below, a core material made of viscoelastic polyurethane in which deformation assisting gaps are entirely formed is embedded in the back surface of a seat body made of urethane pad. This reduces the fatigue of the seated person.

JP 2009-023596 A Japanese Patent Laid-Open No. 03-037010

  In the vehicle seat pad described in Patent Document 1, a large number of concave holes are provided on the upper surface, which may cause the following problems. That is, when the occupant is seated, it feels uneven, and the initial feeling of sitting is poor. Moreover, the shape of a concave hole comes out on the surface of the sheet | seat skin which covers the said pad, and external appearance quality worsens. Further, since it is necessary to increase the hardness in order to compensate for the decrease in rigidity due to the provision of a large number of concave holes, the entire pad becomes hard and the ride comfort of the seated person is deteriorated. Furthermore, if the hip point of the seated person falls too much due to the provision (opening) of the concave hole, the seated person will feel a so-called butt-dropping feeling. In order to prevent this, the setting of the concave hole is limited, and a sufficient weight reduction cannot be achieved.

  On the other hand, in the seat described in Patent Document 2, the core material in which the deformation assisting gap is formed is embedded on the back surface side of the seat body made of the urethane pad, and a large number of concave holes are formed on the upper surface of the urethane pad. Is not formed. For this reason, it is thought that the feeling and appearance quality at the initial stage of sitting do not deteriorate. Further, depending on how the deformation assisting gap is set in the core material, there is a possibility that deterioration in riding comfort can be avoided. However, since the core material is made of non-foamed viscoelastic polyurethane, the mass increases.

  In view of the above facts, the present invention has an object to obtain a vehicle seat pad and a vehicle seat that can reduce the weight while satisfactorily ensuring the ride comfort of the seated person, the initial feeling of sitting and the appearance quality. To do.

  The vehicle seat pad according to the invention of claim 1 is composed of a surface layer portion made of a foam and a foam having a hardness higher than that of the foam, and is bonded to the back surface of the surface layer portion and has a large number of meat. And a back layer portion in which a hole is formed.

  In the vehicle seat pad according to claim 1, since the back layer portion is formed with a number of lightening holes among the surface layer portion and the back layer portion made of foam, the feel and appearance at the initial stage of sitting Good quality can be ensured by the surface layer. In addition, since the back layer portion is made of a foam having a higher hardness than the foam constituting the surface layer portion, the surface layer portion and the back layer portion can be set depending on the setting of the size, number and arrangement of a number of lightening holes. The load deflection curves (compression deflection curves) can be the same or approximate. As a result, even if the surface layer portion and the back layer portion have different hardnesses, the hysteresis loss can be reduced, so that the ride comfort of the seated person can be ensured satisfactorily. Furthermore, since both the surface layer portion and the back layer portion are made of foam, and a number of lightening holes are formed in the back layer portion, the weight can be reduced.

  A vehicle seat pad according to a second aspect of the present invention is the vehicle seat pad according to the first aspect, wherein the density of the foam constituting the back layer portion is 100% of the density of the foam constituting the surface layer portion. Sometimes, it is set within a range of 100% ± 10%.

  In the vehicle seat pad according to claim 2, the density of the back layer portion constituted by the foam having higher hardness than the foam constituting the surface layer portion is the same as or close to the density of the foam constituting the surface layer portion. It is set within the range. Thereby, it can prevent or suppress that the mass of a back layer part increases by the increase in the density of a back layer part. As a result, it is possible to reduce the mass equivalent to the mass of the foam that corresponds to the volume of the many hollow holes formed in the back layer portion.

  A vehicle seat according to a third aspect of the present invention includes a seat cushion having a seat cushion pad and a seat back having a seat back pad, and at least one of the seat cushion pad and the seat back pad includes The vehicle seat pad according to claim 1 or claim 2.

  In the vehicle seat according to the third aspect, since at least one of the seat cushion pad and the seat back pad is the vehicle seat pad according to the first or second aspect, the above-described effects are exhibited.

  A vehicle seat according to a fourth aspect of the present invention is the vehicle seat according to the third aspect, wherein the seat cushion pad is the vehicle seat pad according to the first or second aspect, and the seat cushion is a dummy doll. In the seated state, the deflection rate of the back layer portion immediately below the hip point of the dummy doll is configured to be within a range of ± 5% with respect to the deflection rate of the surface layer portion immediately below the dummy doll. .

  Note that the dummy doll described in claim 4 may be any one of AF05, AM50, and AM95.

  In the vehicle seat according to claim 4, the seat cushion pad of the seat cushion is the vehicle seat pad according to claim 1 or 2. And just below the hip point of the dummy doll seated on the seat cushion, the deflection rate of the back layer portion and the deflection rate of the surface layer portion are configured to be within the same or approximate range. As a result, the load deflection curves of the surface layer portion and the back layer portion immediately below the hip point can be made the same or approximate, so that a natural ride comfort can be given to the seated person.

  As described above, in the vehicle seat pad and the vehicle seat according to the present invention, it is possible to reduce the weight while satisfactorily ensuring the ride comfort of the seated person, the initial feeling of sitting, and the appearance quality.

It is a longitudinal cross-sectional view shown in the state which looked at the vehicle seat which concerns on embodiment of this invention from the seat left side. It is a perspective view which shows the seat cushion with which the vehicle seat is provided. It is a perspective view which shows a part of seat back with which the vehicle seat is provided. It is a disassembled perspective view of the seat cushion. It is the expanded sectional view which expanded a part of Drawing 1, and is a figure showing the state where the dummy doll sat down to the seat cushion. It is a perspective view which shows the test piece comprised with the flexible polyurethane foam which is a material of a surface layer part. It is a perspective view which shows the test piece comprised with the flexible polyurethane foam which is a material of a back layer part.

  Hereinafter, the vehicle seat 10 according to the embodiment of the present invention will be described with reference to FIGS. Note that an arrow FR appropriately shown in each drawing indicates the front direction of the sheet, an arrow UP indicates the upper direction of the sheet, and an arrow W indicates the width direction of the sheet (the left-right direction of the sheet).

  As shown in FIG. 1, a vehicle seat 10 according to this embodiment includes a seat cushion 12 that supports a seated person's buttocks and thighs, a seat back 14 that supports a seated person's back and waist, and a seating position. And a headrest 16 for supporting a person's head.

  The vehicle seat 10 is a rear seat of an automobile, for example, and is a bench seat for three people. In the vehicle seat 10, for example, a seat cushion 12 is attached to the upper surface of a rear floor panel (not shown). The seat back 14 has a lower end connected to the upper surface of the rear floor panel via a hinge bracket (not shown), and an upper end connected to a lock mechanism (not shown) provided on the side or center of the passenger compartment. Yes. The front / rear / left / right / up / down directions of the vehicle seat 10 coincide with the front / rear, left / right / up / down directions of the vehicle.

  As shown in FIG. 2, the seat cushion 12 includes a pair of left and right seating portions 12A arranged at intervals in the seat width direction, and seats between the left and right seating portions 12A and the left and right seating portions 12A. On the outer side in the width direction, a bulging portion 12B bulging upward from the left and right seating portions 12A is formed.

  On the other hand, the seat back 14 is a 6: 4 split-foldable type, and FIG. 3 shows a left side portion 14L of the seat back 14. In the seat back 14, a backrest portion 14A is formed on each of a left side portion 14L shown in FIG. 3 and a right side portion (not shown). The positions of the left and right backrest portions 14A in the seat width direction coincide with the positions of the left and right seating portions 12A. In addition, an armrest accommodating portion 14B that accommodates an armrest (not shown) is formed at the center in the left-right direction of the seat back 14 on the right end side of the left portion 14L.

  The seat cushion 12 is configured such that the surface of a seat cushion pad 18 that is a cushion material is covered with a seat skin (not shown) made of cloth, leather, synthetic leather, PVC, or the like. Similarly, the seat back 14 is configured such that the surface of the seat back pad 20 that is a cushion material is covered with a seat skin (not shown) made of cloth, leather, synthetic leather, PVC, or the like. The seat cushion pad 18 and the seat back pad 20 described above correspond to the “vehicle seat pad” according to the present invention.

  As shown in FIG. 4, the seat cushion pad 18 has an upper and lower two-layer structure in which an upper layer portion 22 as a “surface layer portion” and a lower layer portion 24 as a “back layer portion” are stacked. The upper layer portion 22 and the lower layer portion 24 are both made of a flexible polyurethane foam that is a foam, and the lower layer portion 24 is bonded to the back surface (lower surface) of the upper layer portion 22 by means such as adhesion.

The density of the flexible polyurethane foam constituting the lower layer portion 24 is set within a range of 100% ± 10% when the density of the flexible polyurethane foam constituting the upper layer portion 22 is 100%. Specifically, in this embodiment, the density of the flexible polyurethane foam constituting the lower layer portion 24 and the density of the flexible polyurethane foam constituting the upper layer portion 22 are the same value (for example, 0.035 g / cm ³ ). Is set.

  However, the soft polyurethane foam constituting the lower layer portion 24 is set to have a higher hardness than the soft polyurethane foam constituting the upper layer portion 22. For example, in JIS K6400-2, the hardness of the upper layer portion 22 is set to 100N, and the hardness of the lower layer portion 24 is set to 300N.

  In addition, the lower layer portion 24 has a large number of lightening holes 26 formed thereover, whereas the upper layer portion 22 is not formed with the above-described lightening holes. Each of the hollow holes 26 has a circular shape in plan view, and penetrates the lower layer portion 24 in the sheet vertical direction. The load deflection curve of the upper layer portion 22 and the load deflection curve of the lower layer portion 24 are configured to be the same or approximate by setting the size, the number, and the arrangement of the numerous hollow holes 26. . In other words, the size, the number, and the arrangement of the numerous hollow holes 26 are set so that the load deflection curve of the upper layer portion 22 and the load deflection curve of the lower layer portion 24 are the same or approximate. The shape of the lightening hole 26 is not limited to the circular shape in a plan view and can be changed as appropriate. Further, the lightening hole 26 may be a groove-shaped hole. This point is the same also about the lightening hole 32 mentioned later.

  In the seat cushion pad 18 having the above-described configuration, as shown in FIG. 5, the deflection of the lower layer portion 24 immediately below the hip point HP of the dummy doll D in a state where the dummy doll D for collision test is seated on the seat cushion 12. The rate is configured to be within a range of ± 5% with respect to the deflection rate of the upper layer portion 22 immediately below. The dummy doll D may be any one of AF05 (5th percentile of US adult women), AM50 (50th percentile of US adult men), and AM95 (95th percentile of US adult men). That is, even if any dummy doll D of AF05, AM50, and AM95 is seated on the seat cushion 12, the deflection rate between the upper layer portion 22 and the lower layer portion 24 is configured as described above. The definition of “deflection rate” in the present embodiment is the same as the definition of “deflection rate” in JIS K6400-2.

  On the other hand, as shown in FIG. 3, the seat back pad 20 has a back-and-forth two-layer structure at a portion constituting the backrest portion 14 </ b> A. That is, the portion constituting the backrest portion 14A has a structure in which the front layer portion 28 as the “surface layer portion” and the rear layer portion 30 as the “back layer portion” are stacked. The front layer portion 28 and the rear layer portion 30 are both made of a flexible polyurethane foam that is a foam, and the rear layer portion 30 is bonded to the back surface (rear surface) of the front layer portion 28 by means such as adhesion. Yes. In the present embodiment, the rear layer portion 30 is divided into an upper portion 30A and a lower portion 30B.

  The front layer portion 28 and the rear layer portion 30 are configured similarly to the upper layer portion 22 and the lower layer portion 24 of the seat cushion 12. That is, the density of the flexible polyurethane foam constituting the rear layer portion 30 is set within a range of 100% ± 10% when the density of the flexible polyurethane foam constituting the front layer portion 28 is 100%. The soft polyurethane foam constituting the rear layer portion 30 is set to have a higher hardness than the soft polyurethane foam constituting the front layer portion 28. Furthermore, the rear layer portion 30 is formed with a large number of lightening holes 32 over the whole, whereas the front layer portion 28 has a structure in which such a lightening hole is not formed. . The load deflection curve of the front layer portion 28 and the load deflection curve of the rear layer portion 30 are configured to be the same or approximate by setting the size, the number, and the arrangement of the numerous hollow holes 32. ing.

  Next, the amount of lightening (that is, the number of lightening holes 26 when setting a number of lightening holes 26 and lightening holes 32 for the lower layer portion 24 and the rear layer portion 30 (both of the back layer portions) described above. Of the total volume and the total volume of the many hollow holes 32) will be described. In this calculation method, the amount of lightening is calculated using the following calculation formulas (1) to (3) and the test pieces 34 and 36 shown in FIGS.

  In the following calculation formulas (1) to (3), Ks is a spring constant, W is a load (load), σ is a deflection (deflection), E is an apparent Young's modulus, and AL is The pressure receiving area, h is the height, G is the static shear modulus, S is the shape factor, and AF is the free surface area.

Ks = W / σ = E × AL / h
Σ = W × h / (E × AL) (1)

E = G × (4 + 3.29S ² ) (2)

  S = AL / AF (3)

Further, the test piece 34 shown in FIG. 6 is made of the same material (here, the flexible polyurethane foam) as the surface layer portion (the upper layer portion 22 and the front layer portion 28), the width a is 200 mm, the depth b is 200 mm, and the height (thickness). A) h is formed in a plate shape of 75 mm. The density of the test piece 34 is set to the same value as the density of the upper layer portion 22 (here, 0.035 g / cm ³ ), and the hardness of the test piece 34 is the same value as the hardness of the upper layer portion 22 ( 100N) in JIS K6400-2.

In addition, the test piece 36 shown in FIG. 7 is made of the same material (here, flexible polyurethane foam) as the back layer portion (the lower layer portion 24 and the rear layer portion 30), the width a is 200 mm, the depth b is 200 mm, and the height ( The thickness h is formed in a frame shape of 75 mm, and the width c of the frame portion is set to a constant width of 43 mm. That is, in the central portion of the test piece 36, a lightening hole 38 having a width d of 114 mm, a depth e of 114 mm, and a height h of 75 mm is formed. The density of the test piece 36 is set to the same value as the density of the lower layer part 24 (here, 0.035 g / cm ³ ), and the hardness of the test piece 36 is the same value as the hardness of the lower layer part 24 ( It is set to 300 N) in JIS K6400-2.

  And the deflection amount when the load of 245N, 490N, and 980N is added with respect to each said test piece 34 and 36 is calculated by said calculation formula (1)-(3). Table 1 below shows the calculation results for the test piece 34, and Table 2 below shows the calculation results for the test piece 36.

  As shown in Tables 1 and 2, when the width c of the frame portion of the test piece 36 is set to 43 mm, the deflection amounts σ of the test pieces 34 and 36 are substantially the same. Therefore, the volume of the lightening hole 38 formed in the test piece 36 is the amount of lightening to be obtained. In other words, in the present embodiment, test pieces manufactured by cutting the surface layer portion and the back layer portion into a width of 200 mm, a depth of 200 mm, and a height of 75 mm, respectively, in the height direction with loads of 256 N, 490 N, and 980 N, respectively. A structure in which a number of lightening holes are formed in the back layer portion so that the deflection rate of the test piece cut out from the back layer portion is within ± 5% of the deflection rate of the surface layer portion when compressed. It has become.

  Note that, as in the seat cushion pad 18 and the seat back pad 20 (see FIG. 1) according to the present embodiment, the surface layer portion (upper layer portion 22 and front layer portion 28) and the back layer portion (lower layer portion 24 and rear layer portion 30). ) And the thickness (corresponding to the height h) are different from each other, the load deflection curves of the surface layer portion and the back layer portion are matched or substantially matched while the thicknesses are different.

  Next, the operation and effect of this embodiment will be described.

  In the seat cushion pad 18 of the vehicle seat 10 having the above-described configuration, the lower layer portion 24 made of the flexible polyurethane foam is joined to the back surface of the upper layer portion 22 made of the flexible polyurethane foam. In the lower layer portion 24, a number of lightening holes 26 are formed, but in the upper layer portion 22, no lightening holes are formed. As a result, it is possible to prevent the sheet skin covering the upper surface of the upper layer portion 22 from having a feeling of unevenness, and thus it is possible to ensure a good feeling and appearance quality in the early stage of sitting. That is, it is possible to make the feeling and the appearance quality at the initial stage of sitting equivalent to those of a general seat cushion pad that does not have a two-layer structure.

  And the lower layer part 24 is comprised by the soft polyurethane foam whose hardness is higher than the soft polyurethane foam which comprises the upper layer part 22. FIG. For this reason, even if it is the structure by which many undercutting holes 26 were formed in the lower layer part 24, while being able to prevent a seated person from feeling what is called a fall-off, the setting of many underfilling holes 26 is possible. The restriction can be prevented or suppressed.

  Further, the load deflection curves of the upper layer portion 22 and the lower layer portion 24 are made the same or approximate by setting the size, the number, and the arrangement of the many hollow holes 26. Thereby, the hysteresis loss can be reduced, so that the ride comfort of the seated person can be ensured satisfactorily.

  Furthermore, since both the upper layer part 22 and the lower layer part 24 are comprised with a flexible polyurethane foam, and the many hollow holes 26 are formed in the lower layer part 24, weight reduction can be achieved. Moreover, the density of the flexible polyurethane foam constituting the lower layer portion 24 and the density of the flexible polyurethane foam constituting the upper layer portion 22 are the same. Thereby, it can prevent that the mass of the lower layer part 24 increases by the increase in the density of the lower layer part 24. FIG. As a result, the mass of the flexible polyurethane foam that corresponds to the volume of the numerous hollow holes 26 formed in the lower layer portion 24 can be reduced, so that a significant reduction in weight can be achieved. Moreover, since it becomes possible to manufacture the upper layer part 22 and the lower layer part 24 with the same raw material, it also contributes to the reduction of manufacturing cost.

  Further, in a state where the dummy doll D is seated on the seat cushion 12, the deflection rate of the lower layer portion 24 immediately below the hip point HP of the dummy doll D is ± 5% relative to the deflection rate of the upper layer portion 22 immediately below the dummy doll D. It is configured to be within the range. As a result, hysteresis loss immediately below the hip point HP is reduced, so that a natural ride comfort can be given to the seated person.

  In the present embodiment, the seat back pad 20 has a two-layer structure including a front layer portion 28 and a rear layer portion 30, and the front layer portion 28 has the same configuration as the upper layer portion 22 of the seat cushion pad 18. In addition, the rear layer portion 30 has the same configuration as the lower layer portion 24 of the seat cushion pad 18. Thereby, also in the seat back pad 20, weight reduction can be achieved, ensuring a seating person's riding comfort, the feeling of a seating initial stage, and favorable external appearance quality.

  In the above embodiment, the case where the surface layer part (upper layer part 22, front layer part 28) and the back layer part (lower layer part 24, rear layer part 30) are all formed of flexible polyurethane foam has been described. Not limited to this, the surface layer portion and the back layer portion may be formed of other types of foams.

  Moreover, although the said embodiment demonstrated the case where the vehicle seat 10 was made into the rear seat, you may make it the structure by which the vehicle seat which concerns on this invention was made into the front seat.

  In addition, the present invention can be implemented with various modifications without departing from the scope of the invention. Needless to say, the scope of rights of the present invention is not limited to the above embodiment.

DESCRIPTION OF SYMBOLS 10 Vehicle seat 12 Seat cushion 14 Seat back 18 Seat cushion pad 20 Seat back pad 22 Upper layer 24 Lower layer 26 Meat hole 28 Front layer 30 Rear layer 32 Meat hole D Dummy doll HP Hip point

Claims (4)

A surface layer portion made of foam,
The back layer part which consists of a foam whose hardness is higher than the foam, is joined to the back surface of the surface layer part, and is formed with a number of lightening holes,
Vehicle seat pad with   The density of the foam constituting the back layer portion is set within a range of 100% ± 10% when the density of the foam constituting the surface layer portion is 100%. The vehicle seat pad as described. A seat cushion having a seat cushion pad;
A seat back having a seat back pad;
With
The vehicle seat in which at least one of the seat cushion pad and the seat back pad is the vehicle seat pad according to claim 1. The seat cushion pad is the vehicle seat pad according to claim 1 or 2,
In a state where the dummy doll is seated on the seat cushion, the deflection rate of the back layer portion directly below the hip point of the dummy doll is within a range of ± 5% with respect to the deflection rate of the surface layer portion immediately below the dummy doll. The vehicle seat according to claim 3 configured as described above.

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