JP2003259933A - Seat and pad material for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seat pad material with improved vibration absorbing properties. <P>SOLUTION: The seat pad material has a resonance frequency of ≤3.6 Hz, an amplitude ratio of ≤3.0, an amplitude magnification of ≤0.9 at 6.0 Hz, a core density of ≥48 kg/m<SP>3</SP>and ≤60 kg/m<SP>3</SP>, an air permeability of ≤30 ml/cm<SP>2</SP>s, and an impact resilience of 65±5%. The seat pad material satisfactorily absorbs lower frequency vibration of vertical movement or the like and also higher frequency vibration or microvibration. Therefore, the seat pad material reduces transmission of vibration which is felt by the human body. Urethane foam made from polyol with an average molecular weight of 4,500-5,300 is preferably employed for such a seat pad material to easily attain the vibration absorbing properties. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat installed in a vibrating portion, and more particularly to a seat provided in a vehicle such as a vehicle.

[0002]

2. Description of the Related Art There are various types of general-purpose automobiles such as a type that emphasizes comfort and a type that emphasizes traveling in the suburbs, so-called outdoors. Car seats
In accordance with these purposes, a pad material having a good cushioning feeling or a pad material having a good fitting feeling is used. A pad material with a good cushioning feel is good at absorbing higher frequency vibrations such as micro vibrations transmitted from the road surface when traveling at high speed, but lower frequency vibrations such as vertical movement are easily transmitted to the seated person. . The low frequency vibrations shake the entire body of the occupant. On the other hand, with a pad material having a good fit, low-frequency vibrations such as vertical movement are well absorbed, but fine vibrations with higher frequencies are less likely to be absorbed. The high-frequency vibration causes the portion of the occupant in contact with the pad material, for example, the thigh portion, to quiver.

[0003]

Therefore, according to the present invention,
An object of the present invention is to provide a seat pad material having improved vibration absorption characteristics in the entire range from low frequencies to high frequencies. Also,
An object of the present invention is to provide a vehicle seat with improved vibration absorption characteristics in the entire range from low frequencies to high frequencies.

[0004]

In order to solve the above-mentioned problems, the inventors of the present invention have earnestly studied and as a result, of the two types of conventional pad materials, a pad material having an excellent cushioning feeling has a low resonance frequency. It was found that the absorption capacity for low-frequency vibration is low due to the high resonance magnification, and that the pad material with excellent fit has a lower resonance absorption capacity for high-frequency vibration, although the resonance magnification is smaller than that described above. It was
Then, as a result of researching a pad material having various characteristics while paying attention to a resonance frequency, a resonance magnification, and a vibration transmissibility, a pad material having the following characteristics has been developed. That is, in the present invention, the resonance frequency is 3.6 Hz or less, the resonance magnification is 3.0 or less, the vibration magnification at 6.0 Hz is 0.9 or less, and the core density is 48 kg / m ³ or more and 60 kg / m ³ or less, Provided is a pad material for a sheet, which has an air permeability of 30 ml / cm ² / s or less and a impact resilience of 65 ± 5%. With this sheet pad material, the resonance frequency is 3.6 Hz or less and the resonance magnification is 3.0 or less,
It is possible to favorably absorb lower frequency vibrations such as vertical movement. Further, since the vibration magnification at 6 Hz is 0.9 or less, it is possible to favorably absorb higher frequency vibration, that is, microvibration. Therefore, with this pad material for a seat, the transmission of vibration felt by the human body is reduced. Further, since the impact resilience is 65 ± 5%, the transmission of vibration is reduced, and the cushion feeling and the fit feeling when seated on the pad material are both achieved. Such a pad material has an average molecular weight of 450.
It can be satisfactorily realized by a urethane foam made from a polyol in the range of 0 to 5300 as a raw material. Further, in the present invention, the pad material of the seat portion has a resonance frequency of 3.
6Hz or less, resonance magnification is 3.0 or less, vibration magnification at 6.0Hz is 0.9 or less, and core density is 48kg /
m ³ or more and 60 kg / m ³ or less, and air permeability of 30 ml / cm
Provided is a vehicle seat which is a urethane foam having a rebound resilience of 65 ± 5% at ² / s or less. When the vibration characteristic of the pad material of the seat is within the above range, the vibration that is felt by the body when the vehicle is traveling is preferably reduced from being transmitted to the seated person from the seat. Become.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail. The pad material for a seat according to the present invention can be a known pad material for various seats, that is, a pad material used as a cushion material. Typically, it is made of urethane foam, but may be made of another material having a cushioning property.

When the sheet pad material is made of urethane foam, it can be manufactured by various known manufacturing methods using polyisocyanate and polyol as raw materials. The type of polyol or polyisocyanate is not particularly limited, and may be the material of the pad material used for a known sheet. For example, when manufacturing a pad material for a seat to be installed in a vehicle, a polyol or polyisocyanate used for molding a urethane foam of a vehicle seat can be used. In vehicle seat pad materials, as polyisocyanate,
Tolylene diisocyanate and polymethylene polyphenyl polyisocyanate can be used. As the polyol, for example, polyether polyol can be used, and polypropylene glycol, polytetramethylene glycol, or the like can be used. The polyol preferably has an average molecular weight of 4500 or more and 5
A material of 300 or less is used as a raw material.

The pad material is made of foam. That is, urethane foam can be used. The urethane foam is a slab foam or a mold foam molded by various known methods. Preferably, it is molded by mold foam. The mold foam may be a hot cure mold foam in which the urethane raw material is heated to 160 ° C. or higher and then molded in the mold, or a cold cure mold foam in which the urethane raw material at room temperature is molded in the mold at a predetermined temperature. . In addition, various known members such as a spring for a seat (for a seat cushion) and a frame may be inserted and molded.

The sheet pad material of the present invention thus obtained has a resonance frequency of 3.6 Hz or less, a resonance magnification of 3.0 or less, and a vibration magnification at 6.0 Hz of 0.9 or less. It is characterized by In this specification, the resonance frequency, the resonance magnification, and the 6.0 Hz vibration magnification are numerical values measured by a method according to JASO B407.

The vibration transmissibility of the seat pad material with respect to frequency is represented by a curve as shown in FIG. Further, it has been clarified that the resonance frequency of the human body is around 4 Hz. For this reason, it is preferable that the resonance frequency be as far as possible from 4 Hz, and particularly that it be far from the low frequency side. If the seat pad material has a resonance frequency of 3.6 Hz or less, the human body is unlikely to resonate, and the transmission of vibrations of 10 Hz or less can be satisfactorily reduced.
preferable.

In the seat pad material having a resonance frequency of 3.6 Hz or less, when the resonance magnification is 3.0 or less, the transmissibility of low-frequency vibration can be favorably reduced. When the resonance magnification exceeds 3.0, low-frequency vibrations felt by the body, that is, vertical movement and roll, are transmitted to the body,
I have a bad feeling of sitting. That is, there is little sense of stability, and in the case of a seat installed in a vehicle, car sickness may easily occur. More preferably, the resonance magnification is 2.5 times or less.

In the pad material having the above resonance frequency and resonance magnification, if the 6 Hz vibration magnification is 0.9 or less, the transmission of high frequency vibration can be reduced. 6
When the Hz vibration factor exceeds 0.9, high-frequency vibration, so-called slight vibration, is likely to be transmitted to the human body through the pad material, and the thighs may tremble, which may cause discomfort to the seated person. More preferably, when the 6 Hz vibration magnification is 0.88 or less, high-frequency vibration can be favorably absorbed by the pad material.

When the impact resilience of the seat pad material is 65 ± 5%, a good seating feeling can be obtained in the seat manufactured using the pad material. That is, the pad material has both a good cushioning feeling and a good fitting feeling, and a seat having the pad material in the seat can provide a good seating feeling. If the impact resilience is less than 65-5%, the cushioning feel will deteriorate. If the impact resilience exceeds 65 + 5%, the fit will deteriorate. More preferably, the impact resilience is 65 ± 2%. In this specification, the impact resilience is defined by JIS
It is a value measured according to the regulations of the K6400A method.

Since the pad material for a sheet is a foam, it has a core density of 48 kg / m ³ or more and 60 kg / m ³ or less,
A foam having an air permeability of 30 ml / cm ² / s or less is preferable.

A material having a core density of less than 48 kg / m ³ is likely to transmit low-frequency vibration. In addition, the seat fit and cushion feel are both reduced. Therefore, for example, when such a pad material is used for the seat portion of the seat, the hip portion may sink, and an appropriate height position may not be obtained, or the seating feeling may deteriorate. On the other hand, when the material having a core density of more than 60 kg / m ³ is used, both the cushion feeling and the fit feeling of the seat are improved, but the weight of the pad material is increased and high-frequency vibration is easily transmitted. The core density is more preferably 52 kg / m ³ or more and 60 kg / m ³ or less.
In the present specification, the core density is an apparent density measured according to the regulation of JIS K6400.

When the air permeability is larger than 30 ml / cm ² / s, the vibration transmissibility is increased and the amount of vibration absorption is reduced. Further, if the air permeability is 30 ml / cm ² / s or less, it is expected that the air in the foam can absorb the vibration, and thus the vibration damping effect from the pad material to the human body can be reduced. Can be expected to be done. Preferably, the air permeability is 25 ml / cm ² / s or less. In this specification, the air permeability is JIS K.
It is a value measured according to the regulations of the 6400A method.

In particular, in the case of forming a pad material from a urethane foam, when a polyol having an average molecular weight in the range of 4500 to 5300 is used as a raw material, the impact resilience is 65 ±.
A foam having a repulsion elastic modulus of 5%, particularly 65 ± 2%, can be easily obtained, which is preferable. The type of polyol is not particularly limited, and various polyols that can be used for the pad material for the sheet, such as polyether polyol and polyester polyol, can be used. A polyether polyol is preferable, and specifically, a polyol containing polypropylene glycol, polytetramethylene glycol, or the like as a starting material is preferable.

In the sheet pad material having air permeability, core density and impact resilience in these ranges, the resonance frequency is 3.6 Hz or less and the resonance magnification is 3.0 or less.
When the vibration magnification at Hz is 0.9 or less, the transmission of various vibrations felt by the body is reduced, and the seat pad material has an improved feeling of sitting. Further, it is possible to reduce the weight and material cost of the pad material to obtain a seat pad material having improved vibration absorption characteristics.

The pad material is formed by various known methods.
It is formed into a sheet by being integrated with a member such as a frame that can form the outer shape of the sheet. Typically, a skin covering the surface of the pad material is provided. The method of integrating the pad material and the frame or the like is not particularly limited, and various methods can be used. For example, wrap it around a frame,
The pad material can be molded into a shape that can be engaged with the frame or the like. Alternatively, the pad material may be formed into a predetermined shape by inserting a mounting member such as a screw, a bolt, or a nut to which a fixing tool can be attached, and the pad material may be fixed to the frame or the like by the fixing tool. Alternatively, the pad material may be insert-molded with a die into which a frame or the like is inserted, so that the pad material and the pad are integrated at the same time.

The pad material is preferably used as a cushion material for the seat portion. It is preferable that the main portion of the seat portion, that is, the portion where the hips and thighs of the occupant come into contact is formed of this pad material, and that the cushion material of the entire seat portion is this pad material, More preferable. Also,
It can be used as a pad material for various parts such as a back part, that is, a back part, an armrest part, a headrest part, and a footrest part.

Particularly, in a vehicle seat, a resonance frequency is 3.6 or less and a resonance magnification is 3.0 or less in a main part of a seat, that is, a portion where a seated person's hips or thighs come into contact. It is preferable that the pad material is made of urethane foam having a vibration magnification of 0.9 or less at 6 Hz. A seat with such a pad material has excellent vibration absorption characteristics in both the low frequency region and the high frequency region, so that it can be used in various situations, such as a stable fit feeling in city driving and cushioning when driving on rough roads. It is a vehicle seat that has both a feeling. The vehicle is preferably a passenger car or a motorcycle, but is not limited to this and is suitable for a seat provided in various vehicles such as a working vehicle. Further, the present invention is not limited to a vehicle, and is suitable for a seat installed on a moving object such as a vehicle or a seat installed in a vibrating place. Needless to say, the present invention can also be applied to seats (chairs) provided with a pad material, such as sofas, office chairs, and folding chairs.

[0021]

Example 1 Polymer-dispersed polyol and polyisocyanate (TDI / M) having an average molecular weight of 4950 and an average number of functional groups of 2.9, in which fine polymer particles are stably dispersed.
DI = 80/20), water as a foaming agent, and additive aids such as a catalyst and a cross-linking agent are mixed and put into a molding die, and foamed at a temperature of 65 ° C., a time of 6 minutes, and a liquid temperature of 25 ° C. did. A test piece of 400 × 400 × 100 mm was prepared from the obtained foam-molded product in accordance with the regulations of JASO B407 to prepare Sample 1
The vibration transmissibility to frequency (displacement amount divided by amplitude, amplitude ± 25 mm, load 50k) by 400 x 400 x 100 mm test piece type vibration test measurement method.
g, sweep rate 3.75 Hz / min).

Further, a conventional urethane foam material (high resilience foam) used as a pad material having a good cushioning feeling and a conventional urethane foam material (low resilience type) used as a pad material having a good fitting feeling. With respect to the repulsive foam, the same test pieces were prepared as Comparative Samples 1 and 2, and the vibration transmissibility with respect to frequency was measured by the same vibration test measurement method.

Regarding the obtained Sample 1 and Comparative Samples 1 and 2, the resonance frequency was measured in accordance with the regulations of JASO B407.
The resonance magnification and 6 Hz vibration transmissibility were measured. Furthermore, for sample 1 and comparative samples 1 and 2, JIS K64
The air permeability and the impact resilience were measured according to the regulations of 00.
Table 1 and FIG. 1 show each measurement result and the average molecular weight of the polyol used in the production of each of Sample 1 and Comparative Samples 1 and 2.

The sample 1 has a low resonance frequency of 3.59 Hz and a low resonance magnification of 2.45. Also,
The 6 Hz vibration transmissibility is as small as 0.85. As a result, 0H
In the range of z to 10 Hz, the vibration transmissibility of Sample 1 is small, and the vibration transmission that is easily felt by the body is reduced. In particular, since the resonance magnification is 2.45 times, which is smaller than the comparison samples 1 and 4.81 times and 3.70 times, the amplification of the vibration at the resonance frequency and the frequencies around it is small.

On the other hand, in the comparative sample 1, the resonance frequency is 3.
Although it is as small as 38 Hz, the resonance magnification is as large as 4.81. For this reason, vibrations at a frequency of 3.38 Hz and its surroundings are greatly amplified. Further, in the comparative sample 2, the resonance magnification is about 3.70 times, but the resonance frequency is 3.75 Hz, which is close to 4 Hz which is said to be the resonance frequency of the body. For this reason, the amplification of the vibration of about 4 Hz is relatively large, and it is easy to give a discomfort to a person sitting in the seat provided with this pad material. Also, the 6 Hz vibration transmissibility is 0.9
5 and 0.9 are exceeded, and for the vibration in the range of 0 to 10 Hz, the absorption amount of the vibration is reduced as a whole.

(Example 2) A foam molded article prepared in the same manner as in Sample 1 was used as a pad material for a seat by a known method to prepare a sheet, and a vibration transmission force when running on a test course was measured. . The measurement was performed with a panelist having a weight of 80 kg sitting, and the frequency, frequency and transmissibility were measured by installing an accelerometer under the hip of the test course. Further, the same urethane foam as that of Comparative Sample 1 was used as a pad material of a seat cushion by a known method to prepare a similar sheet, and the frequency and vibration transmissibility were measured in the same manner. The obtained results are shown in FIG.

Comparing the sample 1 with the comparative sample 1, the sample 1 had a small vibration transmissibility in the frequency range of 15 Hz or less, which is the vibration felt by the body. From this, it has been clarified that the sample 1 can absorb various vibrations and can reduce the transmission of various vibrations that are easily felt by the body. Particularly, in Sample 1, the amount of amplification of low-frequency vibration around 5 Hz is reduced, and a sheet that does not easily shake the body can be formed. Also, 10 Hz
In the range of up to 16 Hz, the amount of vibration absorption is increased, and the transmission of microvibration that causes a small trembling of a local body is satisfactorily reduced.

(Embodiment 3) Using the same seat as in Embodiment 2, the ease of use and discomfort after running for 1 hour on a general road with seats seated by five panelists were evaluated. received. The evaluation method was set such that the sheet using the comparative sample 1 which is one of the conventionally used urethane foams had the easiness of sticking, the discomfort was 3.0, and the degree of less fatigue and the degree of relief of the discomfort were further evaluated. The method with a high numerical value was used. Table 2 shows the evaluation of the sheet using the sample 1 and the sheet using the comparative sample 1.

From these results, it was found that the sheet prepared by using the sample 1 can improve the easiness of sticking and alleviate the discomfort by everyone compared with the sheet prepared by using the comparative sample 1. .

[0030]

The present invention can provide a seat pad material having improved vibration absorption characteristics. In addition, it is possible to provide a vehicle seat with improved vibration absorption characteristics.

[Brief description of drawings]

FIG. 1 is a table showing various properties of Sample 1 and Comparative Samples 1 and 2.

FIG. 2 is a graph showing vibration transmissibility of sample 1 and comparative samples 1 and 2 with respect to frequency.

FIG. 3 is a graph showing the vibration transmissibility of the seat for each frequency when the seat provided with the urethane foam of Sample 1 or Comparative Sample 1 is installed in the seat pad material and the vehicle is run.

FIG. 4 is a table showing the results of a sensory test during running of the vehicle.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takayuki Sasaki             25 Asahi, Towada, Kazasu-machi, Kashima-gun, Ibaraki             Glass Urethane Co., Ltd.

Claims (3)

[Claims] 1. A resonance frequency is 3.6 Hz or less and a resonance magnification is
3.0 or less, vibration magnification at 6.0 Hz is 0.9 or less
And Core density is 48 kg / m³60kg / m or more³Below, and
Air permeability 30ml / cm ²/ S or less, the impact resilience is 65
Pad material for seats, which is ± 5%. 2. The pad material for a sheet according to claim 1, which is a urethane foam made from a polyol having an average molecular weight of 4500 to 5300 as a raw material. 3. The pad material of the seat is Resonance frequency is 3.6Hz or less, resonance magnification is 3.0 or less,
The vibration magnification at 6.0 Hz is 0.9 or less, Core density is 48 kg / m³60kg / m or more³Below, and
Air permeability 30ml / cm ²/ S or less, the impact resilience is 65
A vehicle seat made of ± 5% urethane foam.