JP2002253380A - Structure of seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a seat which shows high decrescence and gives a user an excellent fitted feeling when he/she sits on the seat. SOLUTION: A supporting frame B is made up of a front edge 1, which is placed at the under side of the front of a seat surface and shows rigidity, and S-shaped springs which are joined to the front edge 1 and extends from the front edge 1 to the back. The air permeability of a seat cushion pad A ranges between 0.05 and 1.5 cfm (1.41-42.2 L/min), and hysteresis loss of a core layer shows less than 17%. Polyetherpolyol of 30-80 part by weight containing 20-40 mg KOH/g hydroxyl value as a polyol ingredient and an ethylene oxide unit at the end, polymerpolyol of 70-20 part by weight with the hydroxyl value of 15-30 mg KOH/g, a silicone foam stabilizer, a blowing agent, and a polyisocyanate compound which shows 70/30-90/10 of TDI/MDI constitute the raw material of poly-urethane foam. The average of height of expanded foam for the silicone foam stabilizer shows more than 225 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a seat structure,
More specifically, the present invention relates to a seat structure used for a seat with vibration of an automobile or the like.

[0002]

2. Description of the Related Art Conventionally, in order to improve the riding comfort of an automobile seat cushion, JASO B-407 has been used.
With respect to the prescribed vibration transmissibility characteristics, it is said that it is effective to greatly attenuate the frequency range in which a person feels uncomfortable (4 to 10 Hz: a vibration transmissivity of 6 Hz is usually adopted as an evaluation value). In particular, vibration around 6 Hz is said to be a frequency causing car sickness. Therefore, even with a combination of a seat cushion pad for automobile made of urethane foam and a support frame, development for suppressing the vibration transmission rate to be low. Has been done.

However, the conventional seat cushion pad in which the vibration transmissibility at 6 Hz is kept low has a large resonance magnification (resonance peak) appearing at 2 to 4 Hz in the vibration transmissibility characteristics, so that the occupant sits on the automobile seat cushion. When the vehicle is running, the sense of stability of the body is lost due to the vibration of the vehicle body, and it is not possible to sufficiently prevent the feeling of the body swinging up and down (a so-called chilling feeling). Moreover, even if a seat cushion pad that improves the sense of stability of the body has been developed, in many cases, the characteristics of the seat cushion pad are not sufficiently exhibited by the combination of the seat cushion pad and the frame.

[0004]

Under these circumstances, a combination of a seat cushion pad and a frame for a vehicle such as an automobile is required to reduce the vibration transmissibility around 6 Hz in order to reduce sickness and fatigue of occupants. It is necessary not only to reduce the noise, but also to improve the safety during driving operation (improve the stability when seated in the seat), and it is considered that a device that exhibits a low vibration transmissibility even in a wider range of frequencies is preferable. .

However, generally in terms of vibration engineering, a vibration transmissibility characteristic curve (vertical axis: vibration transmissivity, horizontal axis: vibration frequency)
When the resonance magnification of the vibration transmissibility characteristic at 2 to 4 Hz is reduced, the vibration transmissibility at a relatively high frequency (for example, 6 Hz) related to the cushioning property is increased, and the vibration transmissibility characteristic curve is reduced as a whole. It becomes a broad curve. That is, in the vibration transmissibility characteristic curve, a decrease in the vibration transmissivity and a decrease in the resonance magnification had a trade-off relationship.

Accordingly, an object of the present invention is to provide a high damping property capable of lowering the resonance transmissibility at 2 to 4 Hz and lowering the vibration transmissibility around 6 Hz to the same level as or less than the conventional one. It is an object of the present invention to provide a seat structure having a seat cushion pad and a support frame portion disposed below the seat cushion pad and supporting the seat cushion pad, which has an excellent fit when seated at the same time.

[0007]

The above object is achieved by the invention described in each claim. That is, the characteristic structure of the seat structure according to the present invention is a seat cushion pad comprising a polyurethane foam having a skin layer and a core layer molded by injecting a polyurethane foam material into a mold, and having a single-layer seating surface. And a support frame portion disposed below the seat cushion pad and supporting the seat cushion pad, wherein the support frame portion is disposed at a front lower portion of the seat surface portion and has a front edge having a rigidity function. And a resilient means connected to the front edge and extending and arranged rearward from the front edge, and the seat cushion pad has a gas permeability of 0.05. ~ 1.5 cfm [1.441 to 42.2]
L / min], the hysteresis loss of the core layer is 17% or less, and the polyurethane foam raw material has a hydroxyl value of 20 to 40 as a polyol component.
mgKOH / g, 30 to 80 parts by weight of a polyether polyol having ethylene oxide units at the terminals, and a polymer polyol having a hydroxyl value of 15 to 30 mgKOH / g.
20 parts by weight, silicone foam stabilizer, foaming agent, and TDI / M
A polyisocyanate compound having a DI of 70/30 to 90/10 is used as a constituent material, and the silicone foam stabilizer has an average free foam height of 225 mm or more.

The present inventors have conducted intensive studies on the vibration transmissibility characteristics of a seat cushion pad made of urethane foam, and found that the hysteresis loss of the core layer of the urethane foam was 17% or less and the air permeability including the skin layer was reduced. By adjusting the seat cushion pad to be in a specific range, and further by supporting such a seat cushion pad with a support frame portion, the above-mentioned object which cannot be achieved by the combination of the conventional seat cushion pad and the support frame portion is achieved. The inventors have found that the present invention can be achieved, and have completed the present invention.

According to this configuration, a seat cushion pad having a high degree of freedom in adjusting the hysteresis loss, having an air permeability of 0.05 to 1.5 cfm, and having a hysteresis loss of the core layer of 17% or less can be reliably obtained. , Which has a high damping property capable of lowering the resonance transmissibility at 2 to 4 Hz and reducing the vibration transmissibility at around 6 Hz to the same or less than the conventional one, and has an excellent fit when seated at the same time. A sheet structure is obtained. In addition, it is possible to provide a seat structure that can surely reduce the feeling of squeezing and the pressure on the abdomen when the vehicle is running.

The polyether polyol having an ethylene oxide unit at the terminal has a hydroxyl value of 24 to 36 mg.
When KOH / g is used, the air permeability and the hysteresis loss are within the desired ranges, and the other characteristics required as a seat cushion pad are also excellent.

As the polyisocyanate compound, toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) are used in an equivalent ratio of 70/30 to 90/90.
By using the mixed diisocyanate compound mixed in the range of / 10, the air permeability is 0.05 to 1.5 c.
fm and the hysteresis loss of the core layer is 1
A seat cushion pad of 7% or less can be reliably manufactured.

The silicone foam stabilizer is represented by polydimethylsiloxane or (Chemical Formula 1) in which the equivalent ratio m / n of ethylene oxide units m to propylene oxide units n in the copolymerized polyether is Preferably, the compound has a ratio of 0.4 / 0.6 to 0.05 / 0.95.

[0013]

Embedded image In formula (1), X is an organic residue having 1 to 4 carbon atoms, R is an alkyl group or an acyl group, x is 80 to 250, y
Is from 0 to 50. The above-described seat cushion pad of the present invention has the air permeability of 0.1 to 1.5 cfm [2.81 to 42.2 L / mi].
n. , And the hysteresis loss is more preferably 15% or less. Permeability is ASTM D
It is measured according to -1564 (DOW method).

In the seat cushion pad, the portion between the skin layer and the core portion changes continuously, and the boundary is not clearly formed. However, the hysteresis loss of the core portion clearly indicates the portion of the core layer. Remove and measure.

According to the present invention, as shown in the results of the embodiments described later, the seat cushion has a low resonance magnification in the vibration transmission characteristic curve and a vibration transmission near 6 Hz which is equal to or lower than the conventional one. It becomes a pad. That is, according to the present invention, in any shape,
A seat cushion pad having a lower resonance magnification and a lower vibration transmission rate at 6 Hz than the conventional seat cushion pad can be obtained.

It should be noted that the air permeability is not a value measured including a cover member such as a cloth which is finally covered when a seat is formed, but a characteristic measured including a skin layer of a seat cushion pad.

On the other hand, the hysteresis loss of the core layer, which is shown as a physical property for specifying the seat cushion pad used in the seat structure of the present invention, is almost independent of the air permeability and is determined by the type of the polymer constituting the polyurethane foam. It is a characteristic. Further, a new finding was obtained that the resonance frequency of the polyurethane foam seat cushion pad depends (is proportional) to the hysteresis loss of the core layer, and the resonance frequency is inversely proportional to the resonance magnification. From these facts, it is effective to use a material having a small hysteresis loss of the core layer in order to lower the resonance frequency in order to realize a seat cushion pad having a low resonance magnification and a low vibration transmissibility at 6 Hz. That is what led. The hysteresis loss of the core layer is preferably 17% or less, more preferably 15% or less,
The lower the better.

In the seat cushion pad, the polyurethane foam has a core density of 50 to 65 kg / m ³ , an air permeability of 0.05 to 1.5 cfm, and a hysteresis loss of the core layer of 17% or less. Thus, a seat cushion pad that satisfies all of the compression elastic moduli required for an automobile seat cushion pad can be reliably obtained.
It is effective and preferable for reducing the resonance magnification at ~ 4 Hz and reducing the vibration transmissibility around 6 Hz.

It is preferable that the elastic means is an S-shaped spring extending and arranged along a substantially horizontal plane from the front edge toward the rear side.

According to this configuration, according to this configuration, the pressing force applied to the seat cushion pad constituting the seat can be supported substantially evenly, and the characteristics of the seat cushion pad can be faithfully reflected, which is convenient. It is easy to manufacture and does not cause a rise in manufacturing cost.

In this case, the S-shaped spring may be formed of a curved steel wire literally consisting of a repetition of an S-shape, may be a combination of a straight portion and a curved portion, and is relatively square. The shape may be similar to a U-shape.

A reinforcing spring may be connected to the S-shaped spring. With this configuration, when a load is applied due to the occupant being seated or the like, the S
This is advantageous because a uniform elastic function can be maintained against the bending of the U-shaped spring (in addition to the bending in the vertical direction, attempts to bend so as to spread toward both outer sides of the sheet).

In the case of vibration having a resonance frequency of 3.8 Hz or less, it is preferable that the resonance magnification does not exceed 4.0.

According to this configuration, it is possible to achieve a seat structure having a high damping property and a more excellent fit when seated at the same time.

It is preferable that the hysteresis loss is 20% or less.

According to this configuration, a higher damping rate can be realized, and when vibration is involved, the sitting posture is stable and the fit is improved, which is convenient.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a seat structure according to the present invention will be described in detail below. As shown in FIGS. 1 and 2, the seat cushion is composed of a polyurethane foam having a skin layer and a core layer formed by injecting a polyurethane foam material into a mold and having a one-layer seating surface. It has a pad A and a support frame portion B that is arranged below the seat cushion pad A and supports the seat cushion pad A.

The flexible polyurethane foam constituting the seat cushion pad A used in the seat structure is formed from a polyurethane foam raw material containing a polyol compound, a polyisocyanate component, a foaming agent, a catalyst and a foam stabilizer.

The type of polyol compound used in the flexible polyurethane foam is not particularly limited as long as the value of the hysteresis loss of the obtained seat cushion pad falls within the above-mentioned range. It is preferable to use oxyalkylene glycol because the value of hysteresis loss can be easily adjusted to the value or less.

As the polyoxyalkylene glycol, a so-called polyether polyol in which a polyfunctional alcohol compound is used as an initiator and an alkylene oxide is added thereto is usually used.

Examples of the polyisocyanate compound include various aromatic, alicyclic, and aliphatic polyisocyanate compounds having two or more isocyanate groups, which are generally used in the production of a seat cushion pad, and those polyisocyanate compounds. A modified polyisocyanate compound obtained by modifying an isocyanate compound can be used. Further, two or more polyisocyanate compounds may be used in combination. Among these, toluene diisocyanate, diphenylmethane diisocyanate, and crude MDI are preferred because of their high reactivity, good characteristics of the seat cushion pad, low cost, and the like. Toluene diisocyanate includes 2,4-substituted product and 2,6-substituted product, and the use of a mixture thereof is preferred.
-Substituted / 2,6-substituted mixture ratio is 90/10 to 60 /
The use of a mixture of 40 is preferred. Further, toluene diisocyanate: crude MDI is added in an amount of 70:30 to 90: 1.
The use of a blend having a weight ratio of 0, particularly preferably 80:20 ensures that a foam having a hysteresis loss of the core layer of 17% or less is obtained, and that the foaming efficiency and the reaction curability are good and the overall production efficiency is high. Is higher and more preferred.

Water, HCFC-141b,
HFC-134a, HFC-245fa, HFC-36
Halogenated hydrocarbons such as 5mfc, cyclopentane and n
Low-boiling aliphatic or cycloaliphatic hydrocarbons such as pentane,
Liquefied carbon dioxide and the like. Among these foaming agents, it is preferable to use liquefied carbon dioxide and water in combination, and it is particularly preferable to use water alone. Blowing agent, the core density is added in an amount of 50~65kg / m ^3.

As the foam stabilizer, the average value of the height of the free foamed foam evaluated by the foaming stock solution composition shown in Table 1 was 2
Use one that is 25 mm or more. As such a silicone-based foam stabilizer, a known foam stabilizer which is polydimethylsiloxane or a derivative thereof can be used without limitation. As the silicone-based foam stabilizer, a commercially available product is preferably used. Specifically, SF2965, SF2962, SF2904, S
F2908, SRX294A, (manufactured by Dow Corning Toray Silicone), L-5366, L-5309 (manufactured by Nippon Unicar), B8680 (manufactured by Goldschmidt) and the like are commercially available.

[0034]

[Table 1] In the production of the seat cushion pad, it is also a preferable embodiment to use a low molecular weight polyvalent active hydrogen compound as necessary, and it becomes easy to adjust hysteresis loss, air permeability, and rigidity of the seat cushion pad. Examples of such low molecular weight polyvalent active hydrogen compounds include polyhydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, and glycerin, and ethylene glycol starting from these polyhydric alcohols. Hydroxyl value obtained by polymerizing oxide or propylene oxide is 300 to 1000 mg KO
H / g compounds, alkanolamines such as monoethanolamine, diethanolamine, triethanolamine and N-methyldiethanolamine are exemplified.
These compounds may be used alone or as a mixture of two or more. Use of commercially available products using these compounds is also suitable, and examples thereof include KL-210 (manufactured by Mitsui Chemicals, Inc.), Hard Master 17 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and EL-980 (manufactured by Asahi Glass Co., Ltd.). You.

The amount of each component used in the polyurethane foam raw material containing the polyol compound, the polyisocyanate component, the foaming agent, the catalyst and the foam stabilizer is usually as follows, but the air permeability of the seat cushion pad is as follows. Needless to say, in order to adjust the amount, the amount of use can be appropriately changed.

The equivalent ratio of the hydroxyl group of the polyol component containing the polyol compound to the isocyanate group of the polyisocyanate component (isocyanate index [NCO
index]) is 0.85 to 1.15 (8 in index notation)
5 to 115), and more preferably approximately equivalent 1.0 (100 in exponential notation). When using water as a blowing agent, the amount of water used is
Usually, 0.1 to 100 parts by weight of the polyol compound
8 parts by weight, preferably 2 to 4 parts by weight. The amount of the catalyst is usually 1 to 100 parts by weight of the polyol compound.
0 parts by weight or less, preferably 0.05 to 1.0 part by weight. The amount of the foam stabilizer used is usually 0.01 to 5 parts by weight (in the case of a foam stabilizer diluted with a plasticizer or the like, based on the active ingredient), preferably 0 to 100 parts by weight of the polyol compound. 0.1 to 2 parts by weight.

The air permeability using a foam stabilizer can be adjusted by adjusting the cell diameter of the polyurethane foam. When the cell diameter is reduced, the air permeability can be reduced.

A polyurethane foam molded into a predetermined shape, which is a seat cushion pad, is thus obtained. On the back surface of the seat cushion pad, for example, a supporter or a resin support made of polyurethane, polypropylene, polyethylene, polystyrene or a foam thereof is used. PP
Supporter (reinforcing material) such as cloth, coarse blanket and non-woven fabric
Can be laminated by an integral molding method in which the material is previously inserted into a mold during molding or by bonding after foam molding.

The seats and the like actually mounted on the vehicle are:
The above-described seat cushion pad is covered with an outer layer such as a real leather, a moquette, a tricot, a jersey, a woven fabric, and the like, and a support frame portion described below is attached to the seat cushion pad for assembly of a vehicle. When covering the outer layer with the seat cushion pad, it is also preferable to attach one member of the hook-and-loop fastener to the seat cushion pad by bonding or the like.

Next, the support frame B for supporting the seat cushion pad A will be described. The support frame part B is
As shown in FIG. 2, a front edge portion 1 having a rigidity function and disposed at a lower portion on the front side of a seat surface portion of the seat cushion pad A;
Four S-shaped springs 2 which are elastic means connected to the front edge portion 1 and extended rearward from the front edge portion 1 are provided, and the S-shaped spring 2 is further extended. The long side is arranged in a direction substantially orthogonal to the direction, and a substantially rectangular closed-shaped reinforcing spring 3 is connected to the S-shaped spring 2. Although the reinforcing spring 3 is not always necessary, FIG.
When the load is applied due to the occupant being seated or the like, when the reinforcing spring 3 is arranged as shown in FIG. This is advantageous because a uniform elastic function can be maintained in such a manner as to bend toward both outer sides. S-shaped spring 2
And the connection of the reinforcing spring 3 may be welded or joined,
A steel plate may be bent and covered at the overlapping portion of the S-shaped spring 2 and the reinforcing spring 3 and fixed by a clip method while being covered, and various connection methods can be adopted.

The S-shaped spring 2 has a straight portion 2a and a curved portion 2b.
One end in the longitudinal direction is connected to the front edge 1 and the other end is connected to the connecting rod 4 forming the support frame B. The connection method is not particularly limited as long as the sheet structure has a predetermined strength. FIG. 2 shows an example in which four S-shaped springs 2 are provided. However, the number of S-shaped springs 2 is not limited to this. For example, it can be appropriately selected according to a vehicle type or the like.

[0042]

The embodiments will be described below. In addition, the evaluation methods of the used physical properties etc. are as follows.

[Physical Physical Properties of Seat Cushion Pad] a) 25% ILD (Indentation Load)
Deflection: Load when the seat cushion pad is compressed by 25% with a pressing plate having a diameter of 200 mm (based on JIS K6400). This value is 20kg
It is preferable to be about f in terms of sitting comfort.

B) Air permeability (cfm): ASTM D-1
Measured according to 564. That is, a measurement sample having a length of 50 mm, a width of 50 mm, and a thickness of 25 mm including a skin portion under a hip point, which is a seating surface of a seat cushion pad, is sampled from three places and measured using a measuring instrument manufactured by FLUID DATA. It is a measured value (DOW method).

C) Hysteresis loss (%): 10 cm from the core (excluding the skin layer) of the seat cushion pad.
A measurement sample having a thickness of 0 mm, a width of 100 mm, and a thickness of at least 30 mm was collected and measured according to JIS K-6400. The removed skin layer is about 10 mm. d) Core density (kg / m ³ ): The density measured for the core portion of the seat cushion pad. e) Feeling of feeling cold and pressure on the abdomen: The seat cushion was actually attached to the vehicle, and five panelists got on and traveled, and the sensory evaluation with the actual vehicle was performed. Since the sample having a thickness of 100 mm is not a real type, the evaluation of the actual vehicle was not performed.

[Vibration Transmittance Characteristics of Seat Cushion Pad] Vibration transmission obtained by loading a 50 kg iron-plate type pressure plate and performing a forced vibration test at an amplitude of ± 2.5 mm in accordance with JASO B-407. From the rate curve, resonance frequency (Hz), resonance magnification, vibration transmissibility (6 Hz, 10 Hz)
Was measured. For measurement of vibration characteristics, a seat cushion vibration tester C-1002DL (manufactured by Ito Seiki Co., Ltd.) was used.

[Vibration transmissibility characteristics of a seat structure in which a seat cushion pad is placed on a support frame portion]
The measurement was performed according to ASO B-407 (however, using a JM-50 50 kg iron press type pressure plate).

[Free foam height] Based on the composition shown in Table 1 above, the total amount of the polyol component excluding the isocyanate component was about 600 g (equivalent to 5 times of about 107 g per use). Weigh it, put it in a cylindrical container with a capacity of 1 liter, and use an auto-homomixer AM-M (manufactured by Tokushu Kika Kogyo Co., Ltd.), diameter 40 mm, edge height 5 m
A total of 12 sheets were mounted on a set of 6 disper blades of 6 m in total, and stirred at 3500 rpm for 5 minutes to prepare a polyol component. The polyol component was allowed to stand for 12 to 20 hours, and the diameter of the bottom was 105 mm and the diameter of the opening was 14 hours.
As a foamed container, 2 liters of DespoCup (manufactured by Iuchi Seieido Co., Ltd.) was used as a frustoconical container having a height of 0 mm and a height of 195 mm. The mixture was stirred for 5 seconds, and the isocyanate component was immediately added so that the NCO index became 1.0 (100 in exponential notation).
The mixture was stirred at 500 rpm for 7 seconds to form a foamed composition, and allowed to stand to foam. The foaming composition was mixed so that the total amount was 147.3 g, and both the polyol component and the isocyanate component were used by adjusting the temperature to 25 ° C. As shown in FIG. 4, the free foamed foam height was determined by placing a foamed container containing a foam on a horizontal table and measuring the height using a gold scale. Figure 4 shows the measurement of the free foam height
Shown in In addition, the measurement result of the free foamed foam height (unit: mm) showed a maximum value of 244 mm, a minimum value of 233 mm, and an average value of 238.0 mm. Free foaming was performed 5 times, and the maximum value, the minimum value, and the average value of 5 times were shown. As described above, the silicone foam stabilizer is represented by polydimethylsiloxane or (Chemical Formula 1). In the (Chemical Formula 1), the equivalent ratio m / of ethylene oxide units m and propylene oxide units n in the copolymerized polyether is used. n is 0.4 / 0.6-
Preferably, the compound is 0.05 / 0.95.

[Production of Seat Cushion Pad] The polyurethane foam raw materials used for producing the seat cushion pad are shown in Table 1. In Table 1, the x / y ratio and the m / n ratio of the foam stabilizer are values measured by NMR. The measurement was performed using an FT-NMR DPX400S (BURK
ER) and 2% by weight of heavy foam chloroform
It was measured as a solution. x / y and m / n are respectively expressed by the formula x / y = [(P3-1.5 × P5) / 6] / (P5 /
2) m / n = [(P1-P2-P5) / 4] / (P2 / 3) Here, P1, P2, P3, and P5 are the following H P1 in the chemical formula (2): H of the —OCH ₂ — group and the H (—3.0 to
4.0 ppm) P2: H of C—CH ₃ group (around 1.1 ppm) P3: H of Si—CH ₃ group (around 0 ppm) P5: H of Si—CH ₂ — group in X group (0.45 p
pm).

(Example 1 and Comparative Example 1) Table 2 shows the formulations used for producing the seat cushion pads of Example 1 and Comparative Example 1. After the components shown in Table 2 were blended in the usual manner at the weight ratios shown in the same table and uniformly mixed, a predetermined amount was poured into a mold having a predetermined shape and foamed and cured to obtain a seat cushion pad. .

As the seat cushion pad, a seat cushion having a thickness of 90 mm was manufactured using a seat cushion forming die for an actual vehicle seat cushion pad.

[0052]

[Table 2] FIG. 3 shows the shape of the seat portion of the seat cushion pad. FIG.
Shows the cross-sectional shape in the front-rear direction, that is, the front-rear direction when a person is seated, and (a) position is a seat portion and the thickness is 90 mm.

The ILD measurement position is the seat surface of the seat cushion pad and is shown in FIG. The position below the hip point where the air permeability is measured is near the ILD measurement position.

Tables 3 and 4 show the measurement results of the physical properties of the obtained seat cushion pad and the seat structure and the evaluation results of the feeling of chill. In addition, the measurement regarding the seat cushion pad was performed using a fixed-size sample (400 × 40
0 × 100 t), but the measurement of the sheet structure was performed with a real mold.

[0055]

[Table 3] (Hythros = hysteresis loss)

[Table 4] (Hysteresis = Hysteresis loss) As shown in Tables 3 and 4, the seat structure of the present embodiment has a hysteresis loss, which is a characteristic of the seat cushion pad, within a predetermined range. The feeling of feeling cold and the pressure on the abdomen were good, and the fit when sitting was also good.

On the other hand, in Comparative Example 1, the resonance magnification was large,
It did not satisfy the feeling of chilling and the pressure on the abdomen when the actual seat structure was used.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment in which a seat cushion pad is placed on a support frame portion using a seat structure according to the present invention.

FIG. 2 is a perspective view of a main part showing a support frame part of FIG. 1;

FIG. 3 is a cross-sectional view of an example of a seat cushion pad having a seat portion having a thickness of 90 mm.

FIG. 4 shows a method for measuring the height of a free-foamed foam.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front edge part 2 Elastic means A Seat cushion pad B Support frame part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08G 18/63 C08G 18 / 63F // (C08G 18/63 (C08G 18/63 F 101: 00) 101 (00) (72) Inventor Takanori Sugie 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd. (72) Inventor Katsuya Sato 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber (72) Inventor Kikuo Sekida 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd. F-term (reference) 3B084 CA01 CB01 3B096 AB07 4J034 BA07 DA01 DB03 DB07 DG02 DG03 DQ01 HA01 HA07 HA14 HC12 HC61 HC64 HC67 HC71 JA01 NA01 NA08 QA02 QA07 QB14 QB15 QC02 RA12

Claims (4)

[Claims] 1. A seat cushion pad made of a polyurethane foam having a skin layer and a core layer formed by injecting a polyurethane foam material into a mold and having a single-layer seating surface, and a lower portion of the seat cushion pad. In the seat structure having a support frame portion arranged to support a seat cushion pad, the support frame portion is disposed at a lower portion on the front side of the seat portion and has a rigidity function, and a front edge portion having a rigidity function, And an elastic means extending and disposed from the front edge to the rear side, and the seat cushion pad has an air permeability of 0.05.
１．５1.5 cfm [1.41 to 42.2 L / min. ] And the hysteresis loss of the core layer is 17
% Or less, the polyurethane foam raw material has a hydroxyl value of 20 to 40 mgKOH / g as a polyol component, and a polyether polyol having a terminal of ethylene oxide unit of 30 to 40 mgKOH / g.
80 parts by weight, 70 to 20 parts by weight of a polymer polyol having a hydroxyl value of 15 to 30 mg KOH / g, a silicone foam stabilizer,
Foaming agent and TDI / MDI = 70/30 to 90/10
A sheet structure, characterized in that the silicone foam stabilizer has an average free foam height of 225 mm or more. 2. The seat structure according to claim 1, wherein said elastic means is an S-shaped spring extending and disposed along a substantially horizontal plane from said front edge toward the rear side. 3. The seat structure according to claim 1, wherein the resonance magnification does not exceed 4.0 when the resonance frequency is 3.8 Hz or less. 4. The sheet structure according to claim 1, wherein a hysteresis loss is 20% or less.