JP2995325B2 - Automotive seat cushion pads - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile seat cushion pad (hereinafter, also simply referred to as "cushion pad").

[0002]

2. Description of the Related Art Conventional automobile seat cushion pads made of urethane foam and the like generally tend to be too soft, and the initial sitting comfort is good, but the feeling of pushing up and swinging from below is felt. It is easy to cause numbness and strong fatigue of legs when driving for a long time,
Had been a problem.

In order to solve this problem, a cushion pad having a slab layer having a thickness of about 15 to 20 mm provided on the surface of a high resilience foam by bonding is used.
According to this cushion pad, since the surface is soft and the inside has some elasticity, there is an advantage that it is comfortable to sit on and is hard to be fatigued even after a long operation.

However, such a cushion pad having a two-layer structure requires an extra step of bonding in its manufacture, which causes a problem that the cost is increased and the degree of freedom in design is small.

[0005] The present invention has been made in view of the above, the surface gives a soft feel, good sitting comfort, hardly cause fatigue even after long hours of driving, and does not require a two-layer structure. Therefore, an object of the present invention is to provide a cushion pad that can be manufactured at low cost and has a large degree of freedom in design.

[0006]

Cushion pad of claim 1 SUMMARY OF THE INVENTION is a seat cushion pad for automobiles, made from high-resilience foam seat part is more structure, the high-resilience foam, Torirenjiiso
It contains 10% by weight or less of cyanate, and the remaining
Isocyanate consisting of phenylmethane diisocyanate
And a "3% IS" calculated from the following equation (1) using the "load at 25% strain" and the "load at 3% strain" measured at the seat surface.
R "value is about 6 or more.

“3% ISR” = “load at 25% strain” / “load at 3% strain” (1) Here, “load at 25% strain” refers to pressing with a pressure plate having a diameter of 60 mm. In this case, the load that compresses the thickness by 25% is referred to, and the “load at the time of 3% strain” means the load that compresses the thickness by 3% when pressed by the pressure plate.

[0008] A cushion pad according to a second aspect is an automobile seat cushion pad, wherein a seat surface portion is further provided.
Consists of a structure in a high resilience foam, said Ha
Irresilience foam is tolylene diisocyanate
In a proportion of 10% by weight or less, with the remainder being diphenylmeth
Using isocyanate consisting of tan diisocyanate
The "5% ISR" value calculated from the following equation (2) using the "load at 25% strain" and the "load at 5% strain" measured at the seat portion is approximately 4%.
That is all.

“5% ISR” = “Load at 25% strain” / “Load at 5% strain” (2) Here, “Load at 25% strain” is the same as above.
"5% strain load", when pressed by the pressure plate,
It means the load at which the thickness is compressed by 5%.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A cushion pad A of the present invention
For example, it constitutes a front seat or a rear seat for an automobile as shown in FIG. 1, and a part or the whole of a seat surface portion 1 is made of a high resilience foam. The high resilience foam referred to in the present invention means a highly elastic foam, that is, a foam having a core rebound resilience of 50% or more. The core rebound resilience is measured by the following measuring method.

A test piece having a thickness of 30 mm is collected from the core of the foam, preliminarily compressed 10 times with palm pressure to a distance of about 75% of the thickness of the test piece, and left for 1 minute or more. Then placed specimen horizontal table, the distance from the rigid balls (diameter of about 16 mm, weight 16.29 g) of the test piece 460mm freely down the measures maximum repulsive vertical distance _{D 1} of the that time. The rebound resilience R (%) is calculated by the following equation (3).

R = (D ₁ / D ₀ ) × 100 (3) (D ₀ : free fall distance of a hard sphere (mm), D ₁ : maximum rebound vertical distance (mm)) , A skin made of a synthetic resin sheet or the like, and reference numerals 4 and 5 indicate suspension grooves provided in the seat surface portion 1.

Further, in the vehicle seat cushion pad of the present invention, the seating surface portion 1 is pressed by a pressing plate having a diameter of 60 mm, and based on the result, a value calculated by the equation (1) is obtained.
The% ISR value is about 6 or more, or the 5% ISR value calculated from equation (2) is about 4 or more.

By setting the 3% ISR value or the 5% ISR value within this range, the cushion pad has a comfortable surface because the surface gives a soft touch, and is less likely to be numb or tired even after a long running. Is obtained.

The reason why numbness and fatigue are unlikely to occur is considered to be as follows.

I. With the conventional cushion pad, the wide area from the occupant's buttocks to the thighs was strongly pressed,
According to the cushion pad of the present invention, the center of gravity is applied to a narrow area below the ischial tubercle, and a wide area of strong compression does not occur.

Ii. With conventional cushion pads, the damping is slow and the resonance magnification is high, so there is a large sense of thrust and swing during running, and as a result of applying force to the body in order to maintain the correct posture, physical strength is consumed and tired easily. According to the cushion pad of the present invention, since the attenuation is fast and the resonance magnification is low, there is no problem as described above in the conventional product, and there is no unnecessary consumption of physical strength.

As the high resilience foam constituting the cushion pad of the present invention, a polyurethane foam synthesized from an isocyanate and an active hydrogen compound such as a polyol or water is preferably used.

Isocyanates are mainly MDI (4,
4'-diphenylmethane diisocyanate, 2,4'-
Diphenylmethane diisocyanate, preferably consisting of 2,2'-diphenylmethane diisocyanate), but shall be the one containing the TDI at a ratio of 10% or less with respect to the total isocyanate component. Note that M in this specification
DI includes both pure (monomeric) MDI and crude (polymeric) MDI.

The type of the polyol is not particularly limited.
3028, EP3033, EP828, POP312
8, POP3428, POP3628 (all manufactured by Mitsui Chemicals, Inc.) and the like can be used.

As the components other than those used in the production of the urethane foam, commonly used crosslinking agents, foam stabilizers, catalysts and the like may be appropriately used, and the types thereof are not particularly limited.

Examples of the crosslinking agent include triethanolamine, diethanolamine and the like. Examples of foam stabilizers include SF-2962, SRX-274C, and 2969.
T (Toray Dow Corning Silicone Co., Ltd.)
Manufactured). Examples of the catalyst include DABCO 33L
V (Mitsui Air Products Co., Ltd.), Toyocat E
T, SPF2, MR (all manufactured by Tosoh Corporation) and the like.

Further, if necessary, additives such as water, toner, flame retardant and the like can be appropriately used.

Examples of the flame retardant include CR530, CR5
05 (manufactured by Daihachi Chemical Co., Ltd.).

The method of manufacturing the cushion pad of the present invention is not particularly limited. For example, the above-mentioned components are mixed at a predetermined ratio, uniformly mixed, and then injected into a mold to foam and harden. Obtainable.

When the material is injected into the mold, auxiliary materials such as a back surface reinforcing member may be set and molded integrally therewith. The material of the back reinforcing member is not particularly limited, but a polypropylene net or the like can be suitably used.

[0027]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

1. Manufacture of cushion pad The components shown in Table 1 below were blended in the proportions shown in the table, mixed uniformly, then poured into a mold and foamed and cured to have the end face shapes shown in FIGS. 2 and 3. A molded product was obtained. At that time, the back support member was set in the mold, and was integrally molded. As the back support member, in Example 1 and Comparative Example 1, a polypropylene net (Nisseki Condend Net manufactured by Nisseki Goju Products Co., Ltd.) was used. In Examples 2 and Comparative Example 2, urethane fibers ( Espansione manufactured by Kanebo Co., Ltd.) was used.

FIG. 2 is an end view taken along the center line of the cushion pad, and FIGS. 3 (a) to 3 (c) are end views taken along lines a to c in FIG. The line a
This is a line passing through the hip point, and a depression 3 having a diameter of about 15 mm is provided.

The suspension grooves indicated by reference numerals 4 and 5 in FIG. 2 are respectively provided in the width direction of the cushion sheet. These suspension grooves are provided in the direction of gravity at the time of installation of the cushion sheet, and the angle θ between the suspension groove and the vertical line from the surface of the cushion sheet is 12.6 °. In addition, the depth of the suspension groove is 40 mm
And the distance d between the two suspension grooves is 148 mm.

The dimensions α, β, and γ in FIG. 3 are α = 65 mm, β = 80 mm, and γ = 85 mm, respectively. The distance between the a-line and the b-line is 150 mm, and the distance between the b-line and the c-line is 100 mm.

[0032]

[Table 1]

2.3 Measurement of 3% ISR value and 5% ISR value 3% ISR value at the seat surface of the molded article obtained above,
The 5% ISR value was measured at the seating surface portion between the line a and the line c in FIG. 2 where no suspension groove was provided.

The measurement was carried out using an autograph manufactured by Shimadzu Corporation with a disk having a diameter of 60 mm at a crosshead speed of 100 mm / min.

The results are shown in Table 2 together with the initial thickness of the measurement site.

[0036]

[Table 2]

As shown in Table 2, the cushion pads of Examples 1 and 2 had a 3% ISR value of about 6 or more and a 5% ISR value of about 4 or more.
None meet this criterion.

From these results, in the cushion pad of the present invention, both the hard material such as the polypropylene net of Example 1 and the soft material such as the urethane fiber of Example 2 are used as the back surface support member. However, it can be seen that the characteristics of the present invention appear more remarkably when a hard material is used.

3. Measurement of Load-Deflection Curve The load-deflection curve at the seat surface of the cushion pad obtained in Example 1 and Comparative Example 1 was measured centering on line a (hip point) in FIG. The initial thickness of the measurement site was 64.2 mm in Example 1 and 66.1 mm in Comparative Example 1.

The measurement was carried out using an autograph manufactured by Shimadzu Corporation with a 200 mm diameter disk at a crosshead speed of 100 mm / min.

The results are shown in FIGS.

From these results, it can be seen that the device of Example 1 has a more flexible surface than that of Comparative Example 1 and has a small feeling of pushing up (a large feeling of fit) during traveling.

4. Measurement of body pressure distribution A pressure sensor sheet (BIG manufactured by Nitta Corporation) was placed on the cushion pad obtained in Example 1 and Comparative Example 1.
-MAT2000), height 175cm, weight 65
A kg panelist sat down and measured the body pressure distribution.

The results are shown in FIGS. Score 1 in the figure
５5 indicates that the larger the numerical value, the higher the pressure.

Specifically, in the range of the score 1 in FIG. 6, the minimum value is about 6 (unit: g / cm ² , the same applies hereinafter), and the maximum value is about 5
9, a median value of about 34, a score of 2, a minimum value of about 59, a maximum value of about 110, a median value of about 85, a score of 3, a minimum value of about 110, a maximum value of about 136, A score of 4 indicates that a median of about 136 was detected, and a score of 5 indicates that a median of about 161 was detected.

In the range of the score 1 shown in FIG. 7, the minimum value is about 9, the maximum value is about 59, and the median is about 34. In the range of the score 2, the minimum value is about 59, the maximum value is about 109, and the median is about 109. With a pressure of 84 and a score of 3, a minimum value of about 109 and a maximum value of about 1
A pressure of 34, a median of about 134 in the range of score 4,
A score of 5 indicates that a median pressure of about 159 was sensed.

From these results, in the cushion pad of Comparative Example 1, the wide area from the buttocks to the thighs of the panel was strongly compressed, but in the cushion pad of Example 1, the center of gravity was located in a narrow area below the ischial tubercle. , Comparative Example 1
It can be seen that strong pressure did not occur over a wide area such as.

5. Vibration Test The cushion pads obtained in Example 1 and Comparative Example 1 were subjected to a forced vibration test under the following conditions using a seat cushion vibration tester model C-1002DL manufactured by Ito Seiki Co., Ltd. The results are shown in FIGS.

Pressing plate: JM50 butt type Load: 50 kg (490 N) Amplitude: ± 2.5 mm Frequency: 1 to 10 Hz From these results, the cushion pad of Example 1 has a faster attenuation than that of Comparative Example 1. It can be seen that the resonance magnification is small. This result means that the swinging feeling during actual running is small and fatigue is unlikely to occur.

[0050]

According to the present invention, since the surface gives a soft touch, the seat is comfortable and can be used for a long time.
A cushion pad that does not easily cause numbness and fatigue of the leg can be obtained.

Furthermore, since there is no need to form a two-layer structure having a slab layer on the surface, there are also advantages of low cost and great design freedom.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an automobile seat to which a cushion pad of the present invention is applied.

FIG. 2 is a vertical end view at the center line of the cushion pads manufactured in Examples and Comparative Examples.

FIG. 3 is a lateral end view taken along line a, line b, and line c of FIG. 2;

FIG. 4 is a view showing a load-deflection curve of the cushion pad of Example 1.

FIG. 5 is a view showing a load-deflection curve of the cushion pad of Comparative Example 1.

FIG. 6 is a view showing a body pressure distribution of the cushion pad according to the first embodiment.

FIG. 7 is a diagram showing a body pressure distribution of a cushion pad of Comparative Example 1.

FIG. 8 is a view showing the results of a vibration characteristic test of the cushion pad of Example 1.

FIG. 9 is a diagram showing the results of a vibration characteristic test of the cushion pad of Comparative Example 1.

[Explanation of symbols]

 A: Automotive seat cushion pad 1 ... Seat surface 2 ... Skin 3 ... Dent (hip point) 4,5 ... Hanging groove

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Junji Yamamoto 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd. (56) References JP-A-7-206961 (JP, A) Hei 9-176273 (JP, A) JP-A Hei 8-52287 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A47C 27/00 B68G 5/02 C08J 9/02 CFF C08L 75:04

Claims (2)

(57) [Claims] An automobile seat cushion pad comprising a high resilience foam having a single- layered seating surface, wherein the high resilience foam is tolylene diisocyanate.
Containing 10% by weight or less of
An isocyanate consisting of nylmethane diisocyanate
The urethane foam has a "3% ISR" value calculated from the following equation (1) using "load at 25% strain" and "load at 3% strain" measured at the seat surface. An automobile seat cushion pad having a size of 6 or more. “3% ISR” = “load at 25% strain” / “load at 3% strain” (1) (In the above, “load at 25% strain” is 60 mm in diameter.
Means a load by which the thickness is compressed by 25% when pressed by the pressure plate, and "load at 3% strain" means a load by which the thickness is compressed by 3% when pressed by the pressure plate. ) 2. A seat cushion pad for an automobile, comprising a high resilience foam having a single- layered seating surface, wherein the high resilience foam is tolylene diisocyanate.
Containing 10% by weight or less of
An isocyanate consisting of nylmethane diisocyanate
The urethane foam used has a “5% ISR” value calculated from the following equation (2) using “load at 25% strain” and “load at 5% strain” measured at the seat surface. An automobile seat cushion pad characterized by being 4 or more. “5% ISR” = “load at 25% strain” / “load at 5% strain” (2) (In the above description, “load at 25% strain” is 60 mm in diameter.
Means a load at which the thickness is compressed by 25% when pressed by the pressure plate, and "5% strain load" means a load at which the thickness is compressed by 5% when pressed by the pressure plate. )