JPH09193330A - Shock absorbing material for vehicle sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate handling of a cured molding by covering a surface of a viscoelastic material with a film and improve chemical resistance and water resistance by preventing the viscoelastic material before it is cured from infiltrating into an urethane foam of a mold. SOLUTION: The whole face of a viscoelastic material 14a of a shock absorbing material 14 to be embedded in an intermediate layer of a cushion 12 is covered with a film 14b. Accordingly, handling of the viscoelastic material 14a in the case it is previously cured and formed into a molding is facilitated and work for assembling in the cushion 12 is facilitated. When the shock absorbing material 14 is to be integrally molded by using a recess of a cushion main body 13 as a mold of the shock absorbing material 14 and curing by injecting the viscoelastic material 14a before it is cured into the mold, the viscoelastic material 14a before it is cured does not infiltrate into an urethane foam of the main body 13. Further, even when a gasoline which leaks at the time of oil supply to a fuel tank infiltrates into the cushion 12, the gasoline does not come into contact with the viscoelastic material 14a, so that modification of the viscoelastic material 14a can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorbing material which is used by being incorporated in a seat of a vehicle for imparting elastic force and absorbing vibration.

[0002]

2. Description of the Related Art In a seat installed in a vehicle such as an automobile or a motorcycle, a cushion made of urethane foam is usually covered with a seat skin such as synthetic leather or cloth, and has a hard plate shape. It is mounted on the bottom sheet consisting of members, which allows the vibration generated by the engine and the unevenness of the road surface to occur on the running vehicle body,
The cushion absorbs it so that it is not transmitted to the seated person as much as possible.

In such a vehicle seat, since a cushion made of a simple urethane foam does not have sufficient elastic force and vibration absorbing force for a seated person, a viscoelastic material such as a viscoelastic urethane elastomer is used for the body of the urethane foam. It has been conventionally known that a viscoelastic material sufficiently absorbs vibrations so that vibrations felt by a occupant can be reduced by using a multilayered cushion. (See, for example, JP-A-2-286481, JP-A-3-37010, etc.)

[0004]

By the way, in the shock absorbing material for a vehicle seat made of the conventional viscoelastic material as described above, urethane having a low hardness such as a super soft urethane elastomer is used as a matrix resin. Therefore, there is a problem in demolding and cleaning of the mold when molding with a mold, and since the cured molded product is too sticky and difficult to handle, there is also a problem in workability when assembling it into a sheet. is there.

Therefore, it is considered that the cushion body itself of urethane foam is used as a mold and the viscoelastic material before curing is injected and cured to integrally mold the shock absorbing material with respect to the cushion body. However,
Then, since the urethane foam of the cushion main body, which is a mold, is a continuous foamed body, there is a problem in that the injected viscoelastic material before being cured permeates into the urethane foam.

On the other hand, when such a shock absorbing material made of a viscoelastic material is used for a seat of a motorcycle, gasoline leaked when the fuel tank is filled with oil leaks into the cushion of the seat and comes into contact with the viscoelastic material. Then, the viscoelastic material may be deteriorated, and when it is used for a seat of a water bike, when the water on the seat seeps into the cushion and comes into contact with the viscoelastic material, the urethane of the material is hydrolyzed and viscoelastic. May alter material.

Further, when used in a vehicle seat,
Volatile components of the viscoelastic material are volatilized into the sealed vehicle, which may cause so-called fogging that causes the window glass of the vehicle body to fog. There is a risk of spreading the fire.

[0008]

In order to solve the above problems, the present invention provides a shock absorbing material for a vehicle seat, wherein the surface of the viscoelastic material is a film, as described in claim 1 above. It is characterized by being covered with.

Further, in the impact absorbing material for a vehicle seat described in claim 1, as described in claim 2, the viscoelastic material is made of a resin in a super soft urethane elastomer serving as a matrix resin. It is characterized by being mixed with microballoons.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a shock absorbing material for a vehicle seat according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of a motorcycle seat in which an embodiment of the shock absorbing material of the present invention is used. The seat 1 includes a front seating portion 1a on which a driver is seated,
The main frame 2 is a tandem seat in which a rear seating portion 1b on which a passenger is seated is formed continuously in a stepwise manner.
The fuel tank 3 is disposed above the fuel tank 3 and is fixed while being mounted on a pair of seat frames 4 extending rearward from the rear portion of the main frame 2.

FIG. 2 shows a cross section of the seat front seating portion 1a taken along the line AA in FIG. 1, above the bottom seat 11 made of a plate made of metal or hard synthetic resin. Cushion body 13 made of urethane foam and shock absorber 14
A cushion 12 made of a synthetic leather is placed on the outer surface of PVC (polyvinyl chloride) leather and a lining of wooly nylon. There is.

The shock absorbing material 14 of the present embodiment, which is embedded in the intermediate layer of the cushion 12, has the entire surface of the viscoelastic material 14a covered with the film 14b, and the viscoelastic material 14a is a super soft material. The urethane elastomer is used as a matrix resin and resin-made microballoons are mixed therein, and the synthetic resin film 14b is a urethane film having a thickness of 30 μm.

The ultra-soft urethane elastomer that serves as a matrix resin for the viscoelastic material 14a is a urethane elastomer having a hardness of 15 or less according to Asker C hardness tester, which is a durometer for measuring the hardness of soft materials manufactured by Kobunshi Keiki Co., Ltd. For example, a mixture of a trifunctional polyol and a difunctional polyol (polyether-based polyol, polyester-based polyol), triallyl isocyanurate, MD
A mixture of I (diphenylmethane diisocyanate) / TDI (tolylene diisocyanate) prepolymer, bismuth catalyst, tin catalyst, phthalic acid plasticizer, etc.,
A novel urethane resin described in Japanese Patent Publication No. 3-17848 (Applicant Iida Sangyo Co., Ltd.)
The super soft elastomer composition (Applicant: Nippon Automation Co., Ltd., etc.) and Erascoat (trade name, manufactured by Polyurethane Kasei Co., Ltd.) described in JP-A-37217.

The resin-made microballoons mixed in the matrix resin are made of vinylidene chloride resin (vinylidene chloride acrylonitrile copolymer) having an outer shell (average particle size of 40).
Butene gas is encapsulated in ~ 60 micron, particle size range 10-100 micron, and the product name is Expancel DE (made by Sweden Expancel)
Thus, it has been generally commercially available as a filler having a low specific gravity.

Regarding the mixing amount of the resin microballoons in the viscoelastic material 14a, the mixing amount (% by weight) is 1%.
In the following, it will be separated into two layers after casting and curing, and if the mixing amount (% by weight) is 5% or more, the viscosity after mixing will be high and air will enter at the time of casting. %) Range.

As a concrete example of the viscoelastic material 14a of this embodiment, Orotex U1000 and U1 are used.
Urethane elastomer such as 003 (trade name, manufactured by Iida Sangyo Co., Ltd.) is used as an ultra-soft urethane elastomer, and EXPANCEL DE (trade name, manufactured by Sweden Expancel Co., Ltd.) is used as a resin microballoon.
% Some are mixed.

A viscoelastic material 14a prepared by mixing a resin-made microballoon with the above-mentioned ultra-soft urethane elastomer.
The loss factor can be increased according to the amount of resin microballoons mixed, and is lighter than other viscoelastic materials used as shock absorbers in conventional vehicle seats. (Specific gravity 0.62), small rebound resilience (rebound resilience rate 8%), little change in hardness due to temperature change, high vibration absorption, and good fit.

By the way, the viscoelastic material 14a as described above is used.
The storage elastic modulus of the shock absorbing material 14 of the present embodiment in which the urethane film 14b having a thickness of 30 μ is compared with that of the shock absorbing material 14 of the viscoelastic material 14a alone (not covered by the film) ( The results of measuring the (MPa) and the loss coefficient are as shown in Table 2 below.

[0020]

[Table 1]

From this result, even if the viscoelastic material 14a is covered with the film 14b as in this embodiment, if the film 14b is a thin urethane film having a thickness of about 30 μ, the storage elastic modulus (MPa) and the loss are reduced. It can be seen that there is no significant difference in the coefficients, and it is possible to obtain the elastic force and the vibration absorbing force that are almost the same as in the case of only the viscoelastic material 14a.

On the other hand, the shock absorbing material 14 of this embodiment is embedded in the intermediate layer of the cushion 12. In this respect, the shock absorbing material 14 is absorbed in the intermediate layer of the urethane foam cushion body 13 as shown in FIG. (A) in which the material 14 is arranged, and the shock absorbing material 14 at the bottom of the cushion body 13.
The storage spring constants (k) when the compression jig 20 is pressed as shown in (C) for the arrangement of
The results of measuring the gf / mm) and loss factor are as shown in Table 2 below.

[0023]

[Table 2]

From these results, by arranging the shock absorbing material 14 in the intermediate layer of the cushion 12 as in the present embodiment, compared with the case where the shock absorbing material 14 is arranged at the bottom of the cushion 12, the cushion 12 The sheet 1 can be made to have a lower resilience by increasing the loss coefficient as a whole. (The larger the loss coefficient, the smaller the repulsion and the smaller the vibration transmission)

Now, as in this embodiment, the shock absorbing material 14
When embedded in the intermediate layer of the cushion 12, the cushioning body 1 is made up of the shock absorbing material 14 that has been previously cured to form a molded product.
(3) After being fixed in a molding die, a urethane stock solution is poured into the molding die to foam the same, so that the shock absorber 1
It is also possible to integrally form the urethane foam cushion main body 13 around 4, but in that case, the work of assembling the shock absorbing material 14 at a fixed position in the mold is troublesome, and the finished product is completed. In addition, there is a problem in that the positional accuracy of the shock absorbing material 14 in the cushion 12 also deteriorates.

Therefore, as shown in FIG. 4, first, (A)
The cushion main body 13 is preliminarily molded as two upper and lower urethane foam members 13a and 13b, and (B) a film 14b is attached to the recess 13c formed in the lower urethane foam member 13b, and (C) the recess 13c. After casting the viscoelastic material 14a before curing into the inside and curing,
(D) A film 14b is further attached to the upper surface of the cured viscoelastic material 14a, or a film 14b is attached to a corresponding portion of the upper urethane foam member 13a to integrate both urethane foam members 13a and 13b. As a result, the cushion 12 having the shock absorbing material 14 embedded therein is formed.

According to such a manufacturing method, the shock absorber 1 of the viscoelastic material 14a whose surface is covered with the film 14b.
4 is a cushion 12 with good workability and high position accuracy.
It can be manufactured in a state of being arranged in the intermediate layer.

According to the shock absorbing material 14 for a vehicle seat of the present embodiment in which the entire surface of the viscoelastic material 14a as described above is covered with the film 14b, when it is cured beforehand to form a molded article. The surface of the viscoelastic material 14a is covered with the non-adhesive film 14b, so that the viscoelastic material 14a is easier to handle than the shock absorbing material made of only the viscoelastic material, and is easy to handle when the cushion 12 is assembled. Work can be performed easily.

On the other hand, the recess 13 of the cushion body 13 itself
When c is used as a mold of the shock absorbing material 14 and the viscoelastic material 14a before hardening is injected into the mold to be hardened, the shock absorbing material 14 is integrally molded with the cushion body 13. As a result, due to the presence of the film 14b attached to the concave portion 13c so as to cover the lower surface and the side surface of the viscoelastic material 14a, the viscoelastic material 14a before curing may permeate into the urethane foam of the cushion body 13. Can be prevented.

Further, as in the present embodiment, the shock absorbing material 14
Fuel tank 3 when used as a motorcycle seat 1
When the gasoline leaking at the time of oil injection into the cushion 12 of the seat 1 is impregnated with the viscoelastic material 14a, the film 14b prevents the gasoline from coming into contact with the viscoelastic material 14a. It is possible to prevent alteration of the viscoelastic material 14a due to the action, and improve the chemical resistance of the shock absorbing material 14.

Although one embodiment of the impact absorbing material for a vehicle seat according to the present invention has been described above, the present invention is not limited to the specific embodiment as described above. The present invention is not limited to the motorcycle seats described above, but can be applied to other vehicle seats such as automobiles and watercrafts.

That is, in the case of being used for a seat of a water-bike, even if water permeates into the cushion of the seat, the contact of water with the viscoelastic material 14a is prevented by the film 14b, so that the viscoelastic material 14a comes into contact with water. As a result, the hydrolysis of the urethane component can be prevented, and the water resistance of the shock absorbing material 14 can be improved.

When it is used for automobile seats,
The volatilization of volatile components from the viscoelastic material 14a prevents the film 14 from being evaporated.
Since it is blocked by b, it is possible to prevent so-called fogging such that the volatile component fills the interior of the vehicle and cloud the window glass, and imparts flame retardancy to the shock absorbing material 14, which is a viscoelastic material that is easy to burn. It is possible to reduce the risk of fire in the car at the time of an accident.

Further, regarding the structure itself, the entire surface of the viscoelastic material 14a as described above is formed into the film 14b.
In addition to the structure covered by
Further, as shown in FIG. 6, it is also possible to implement by a structure in which only a necessary portion of the surface of the viscoelastic material 14a is partially covered with the film 14b.

As for the constituent material, the viscoelastic material 14a is not limited to the one in which the resin microballoons are mixed as described above, but other conventionally known materials that can be used as a shock absorbing material. It is also possible to implement it with a viscoelastic material, and also to use the viscoelastic material 14
The film 14b that covers a is not limited to the urethane film as described above, but any flexible film such as a vinyl chloride film, a polypropylene film, a polyethylene film, a fluorine film, or the like can be appropriately used.

The thickness of the film 14b to be used is not limited to 30 .mu., But can be appropriately selected within the range of about 15 to 100 .mu., And the material and thickness of the film 14b to be coated can be appropriately changed. , Viscoelastic material 14
Even if a is the same, the rigidity of the shock absorber 14 can be adjusted appropriately.

Further, regarding the arrangement of the shock absorbing material 14 with respect to the cushion 12 of the seat 1, the cushion 12
Not only the intermediate layer, but also the upper layer and the bottom portion can be arranged, and the rigidity of the seat 1 as a whole can be appropriately adjusted by changing the positional relationship in the cushion 12.

[0038]

According to the impact absorbing material for a vehicle seat of the present invention as described above, it is possible to improve chemical resistance and water resistance as compared with a conventional impact absorbing material using a viscoelastic material. Flammability can be imparted, anti-fogging property can be improved, and rigidity can be easily adjusted, and when handled as a pre-cured molded product, the handling is easy. While becoming something
When the impact absorbing material is molded by using the urethane foam cushion main body as a mold, it is possible to prevent the viscoelastic material before curing injected into the mold from seeping into the urethane foam of the mold.

[Brief description of the drawings]

FIG. 1 is a side view near a seat of a motorcycle showing an example of a vehicle seat using a shock absorbing material according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of the sheet shown in FIG.

FIG. 3 is a storage spring constant of the cushion as a whole in the case where the shock absorbing material of the present invention is arranged in the intermediate layer of the cushion (A), the case where it is arranged in the bottom portion of the cushion (B), and (C) FIG. 4 is an explanatory view showing a jig for measuring a loss coefficient and a jig.

FIG. 4 is an explanatory view showing a manufacturing process in the case of integrally molding the shock absorbing material of the present invention by using the cushion itself of the seat as a mold.

FIG. 5 is a cross-sectional view of a cushion using a shock absorbing material according to another embodiment of the present invention.

FIG. 6 is a cross-sectional view of a cushion using a shock absorbing material according to still another embodiment of the present invention.

[Explanation of symbols]

 1 Seat 12 Cushion 13 Cushion Main Body (Urethane Foam) 14 Shock Absorber 14a Viscoelastic Material 14b Film

Claims (2)

[Claims] 1. A shock absorber for a vehicle seat, wherein the surface of the viscoelastic material is covered with a film. 2. The impact absorbing material for a vehicle seat according to claim 1, wherein the viscoelastic material is a super soft urethane elastomer as a matrix resin mixed with resin microballoons.