JP2005021671A - Seat cushion pad for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seat cushion pad for a vehicle comfortable to sit and ride on. <P>SOLUTION: In this seat cushion pad for the vehicle, wherein a hip lower part 2, a thigh lower part 3 and a side part 4 are formed of polyurethane foam, resonance magnification in the resonance frequency 15-30 Hz of polyurethane foam constituting the thigh lower part 3 is 0.2-0.5, and the density of polyurethane foam of the thigh lower part 3 is preferably about 40-80 kg/m<SP>3</SP>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle seat cushion pad, and more particularly, to a vehicle seat cushion pad that is reduced in weight and cost without impairing sitting comfort, riding comfort, and durability.

  A seat cushion pad attached to a seat of an automobile or the like is made of polyurethane foam, and is manufactured by injecting a urethane stock solution into a mold and performing foam molding.

  By the way, in the vehicle seat, the lower thigh of the seating surface is a place where the thigh of the occupant touches, and the material of this part is closely related to the sitting comfort and the riding comfort.

Japanese Patent Application Laid-Open No. 2002-153357 describes that the lower thigh is made of polyurethane foam having a density of 40 to 80 kg / m ³ and a 25% ILD hardness of 150 to 300N.
JP 2002-153357 A

  Attempts have been made to improve sitting comfort and riding comfort by changing hardness and coefficient of restitution between the lower thigh and lower buttocks. It has been studied how to select the hardness and density to improve the sitting comfort and riding comfort, but it has not been known what kind of characteristics to improve the sitting comfort and riding comfort.

  An object of this invention is to provide the vehicle seat cushion pad which has the characteristic that a seating comfort and riding comfort become favorable.

  The vehicle seat cushion pad of the present invention (Claim 1) is a vehicle seat cushion pad made of polyurethane foam, and the average resonance magnification at a resonance frequency of 15 to 30 Hz of the lower thigh of the seating surface is 0.5 or less. It is characterized by this.

  The vehicle seat cushion pad according to a second aspect is characterized in that, in the first aspect, an average resonance magnification at a resonance frequency of 15 to 30 Hz of the lower thigh is 0.2 to 0.5.

A vehicle seat cushion pad according to a ^third aspect is characterized in that, in the first or second aspect, the density of the polyurethane foam in the lower thigh is 40 to 80 kg / m ³ .

The vehicle seat cushion pad according to claim 4 is characterized in that, in claim 3, the density of the polyurethane foam in the lower thigh is 50 to 70 kg / m ³ .

  A vehicle seat cushion pad according to a fifth aspect of the present invention is the vehicle seat cushion pad according to any one of the first to fourth aspects, wherein a 25% ILD hardness of a lower thigh is 140 to 180 N.

  A vehicle seat cushion pad according to a sixth aspect of the present invention is the vehicle seat cushion pad according to any one of the first to fifth aspects, wherein a rebound rate of a lower thigh is 70 to 90%.

  A vehicle seat cushion pad according to a seventh aspect of the present invention is the vehicle seat cushion pad according to any one of the first to sixth aspects, wherein the side portion has a hardness of 400 × 400 × 100 mm made of the material of the side portion. Is measured by the 6.7D method of JIS K 6400-2: 2004, and the hardness is 140 to 500N.

  In the present invention, there is a significant correlation between the average resonance magnification at the resonance frequency of 15 to 30 Hz of the lower thigh and the sitting comfort and riding comfort, and this resonance magnification is 0.5 or less, particularly 0.2 to 0.5. It was invented by finding that sitting comfort and riding comfort are improved by doubling.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of a vehicle seat cushion pad according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG.

  The vehicle seat cushion pad 1 includes a bottom part 2, a thigh part 3, and a side part 4. The lower buttocks 2 and the lower thigh 3 are located in the center in the left-right direction of the vehicle seat cushion pad 1, and the lower thigh 3 is disposed in front of the lower buttocks 2. The side portions 4 are located on both the left and right sides of the lower buttocks 2 and the lower thigh 3. When the occupant sits on the seat cushion in the normal posture, the butt of the occupant rests on the lower butt 2 and the thigh rests on the lower thigh 3. These bottom part 2, lower leg part 3, and side part 4 are all made of polyurethane foam.

The polyurethane foam of the lower thigh 3 has an average resonance magnification at a resonance frequency of 15 to 30 Hz of 0.5 or less, preferably 0.2 to 0.5, particularly preferably 0.2 to 0.45. The density of the lower thigh 3 is preferably 40 to 80 kg / m ^3, particularly preferably 50 to 70 kg / m ³ , and the hardness is preferably about 140 to 180 N, particularly about 160 to 170 N in terms of 25% ILD hardness. The rebound rate of the lower thigh is preferably about 70 to 90%. This repulsion rate is measured by implementing the ninth term of “JIS K 6400”.

The density of the bottom part 2 is preferably about 40 to 80 kg / m ^{3 in} order to ensure sitting comfort, riding comfort, durability, and the like. Further, the hardness is preferably about 150 to 300 N at 25% ILD hardness.

  The density of the side part 4 is preferably about 40 to 95% of the density of the polyurethane foam in the bottom part 2 for weight reduction. The hardness of the side portion is a test piece of 400 × 400 × 100 mm made of the material of the side portion, and the hardness when the test piece is measured by the 6.7D method of JIS K 6400-2: 2004 is 140 to 500N is preferable, and in particular, 200 to 450N is preferable in order to enhance supportability.

  The molecular weight of the polyol for forming the polyurethane foam constituting the lower thigh 3 is preferably about 5000 to 8000.

  In order to mold the vehicle seat cushion pad of the present invention, a urethane compound stock solution for molding the bottom part 2, the thigh part 3 and the side part 4 is prepared and injected into the entire mold at the same time or with a time difference. Then, foam molding may be performed. The urethane compound stock solution is obtained by mixing a polyol compound solution in which additive components such as a catalyst and a foaming agent are blended with a polyol component and an isocyanate component immediately before molding.

  By varying the molecular weight of the polyol and the isocyanate index at the time of blending, the hardness of the polyurethane foam to be molded can be adjusted, and the resonance magnification at a resonance frequency of 15 to 30 Hz can be adjusted.

  In the vehicle seat cushion pad according to the present invention, a rear edge portion having different characteristics from the bottom portion 2 may be formed behind the bottom portion 2.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

Examples 1-3, Comparative Examples 1-3
The left / right maximum width is about 51cm, the front / rear maximum length is about 56cm, the bottom left / right width is about 32cm, the bottom bottom front / rear length is about 23cm, the thigh bottom left / right width is about 36cm, and the bottom thigh length is about 26cm A vehicle seat cushion pad was manufactured by urethane foam molding. After that, it was attached to a seat cushion frame to produce a seat.

  This seat was attached to a seat vibration device G-9215L manufactured by KENKEN Co., Ltd., and the vibrations were varied by changing various resonance frequencies within the range of resonance frequencies 1 to 50, and the sitting comfort and riding comfort of the seated person (monitor) were monitored. . The monitor is 50 adult men and women aged 20-60. In this monitoring, in addition to individual items such as the softness of the lower thigh and the degree of repulsion, comprehensive sitting comfort and riding comfort were answered. The overall sitting comfort and riding comfort were evaluated on a 10-point scale from -5 points to +5 points, and the average of all 50 persons was adopted.

  The results are shown in Table 1. Table 1 shows the 25% ILD hardness (N) of the lower thigh and the hardness measured by the 6.7D method of JIS K 6400-2: 2004 of the side part and the side part supportability evaluation.

  In addition, the hardness measured by the 6.7D method of JIS K 6400-2: 2004 of the side part is pressed against the surface of the side part sample of 400 mm × 400 mm × 100 mm thickness by pressing a 20 mm diameter hemispherical presser. It is the value (N) of the difference between the reaction force when pre-compressed 15 mm vertically from the surface and the reaction force when it is further pushed in by 15 mm.

  In addition, the support of the side part is a four-point evaluation of the feeling of hitting the side part when sitting on the seat pad and shaking the body from side to side (for example, it fits reasonably hard; feels hard and feels strange). is there.

  As shown in Table 1, there is a significant correlation between the average resonance magnification of the resonance frequency of 15 to 30 Hz and the sitting comfort / riding comfort, and this resonance magnification is 0.5 or less, particularly 0.2 to 0.5, especially 0. By setting it to .25 to 0.45, it is possible to obtain a good sitting comfort and riding comfort.

  As described above, according to the present invention, there is provided a vehicle seat cushion pad having good sitting comfort and riding comfort.

1 is a perspective view of a vehicle seat cushion pad according to an embodiment of the present invention. It is the II-II sectional view taken on the line of FIG.

Explanation of symbols

1 Seat cushion pad for vehicle 2 Lower buttocks 3 Lower thigh 4 Side part

Claims (7)

  A vehicle seat cushion pad made of polyurethane foam, wherein an average resonance magnification at a resonance frequency of 15 to 30 Hz of a lower thigh of a seating surface is 0.5 or less.   The vehicle seat cushion pad according to claim 1, wherein an average resonance magnification at a resonance frequency of 15 to 30 Hz of the lower thigh is 0.2 to 0.5. ^{3. The} vehicle seat cushion pad according to claim 1, wherein the density of the polyurethane foam in the lower thigh is 40 to 80 kg / m < ³ >. 4. The vehicle seat cushion pad according to claim 3, wherein the density of the polyurethane foam in the lower thigh is 50 to 70 kg / m ³ .   The vehicle seat cushion pad according to any one of claims 1 to 4, wherein a 25% ILD hardness of a lower thigh is 140 to 180N.   The vehicle seat cushion pad according to any one of claims 1 to 5, wherein a rebound rate of a lower thigh is 70 to 90%.   The hardness of the side part according to any one of claims 1 to 6, wherein a test piece of 400 × 400 × 100 mm is made of the material of the side part, and the test piece is formed according to 6. of JIS K 6400-2: 2004. A vehicle seat cushion pad having a hardness of 140 to 500 N as measured by the 7D method.

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