JPH11137365A - Seat for vehicle and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat for a vehicle of excellent cushion property, weather resistance and durability and a low manufacture cost and its manufacture. SOLUTION: In a seat back 2 with a headrest composed of a frame 6, a cushion main body 8 and a facing 10 formed from a urea resin material, at the time of molding the seat back 2, the facing 10 is formed by blowing the urea resin material to a lower die 12 beforehand. Then, the seat back 2 and a seat cushion manufactured in a different process by the same method are assembled and this seat for the vehicle is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle seat and a method for manufacturing the same, and more particularly, to a vehicle seat excellent in durability including cushioning and weather resistance and a method for manufacturing the same.

[0002]

2. Description of the Related Art A vehicle seat includes a seat cushion, a seat back, and a headrest. In the prior art, these have three main components, namely, a frame, a cushion main body that receives and supports the occupant's body, and a skin that directly touches the occupant's body. Usually, of these members, the frame is formed by assembling steel pipes or steel plate pressed parts, the cushion body is formed by molding a foamable synthetic resin material, and the skin is genuine leather or vinyl leather. And other materials cut and sewn are used.

[0003] A seat cushion, a seat back and a headrest are manufactured separately from a frame to a skin in separate steps, and then the completed seat cushion, seat back and headrest are assembled to obtain a vehicle seat. In some cases, after forming a product in which only the cushion body of the seat cushion, the seat back and the headrest are integrated, a frame manufactured in a separate process is incorporated into the molded product, and further covered with a skin to obtain a completed vehicle seat. .

[0004] As described above, it is basically required that a vehicle seat receive the body of an occupant and have a sense of stability with little fatigue even when seated for a long time.
It is important to have a comfortable cushioning property, and that there is no deterioration or deterioration even after long-term use,
In addition, it is required to manufacture such a vehicle seat at low cost and with high production efficiency.

[0005] Therefore, as an improved technique for the epidermis,
When integrally molding the cushion portion using a mold, after introducing a vinyl-based material such as the above-mentioned vinyl leather into the mold in advance and forming a skin in the mold, the foamable urethane resin material or the like is used. Japanese Patent Laying-Open No. 48-84867 discloses a technique in which a cushion body and a skin are integrally formed with one mold by injecting the cushion body into a mold. Similarly, as an improved technology for the skin, a cushion body made of foamable polyurethane resin material is molded integrally with a sheet pan made of steel sheet, and at that time, the foamable polyurethane resin material forms the skin itself, so-called Integra Japanese Patent Application Laid-Open No. 46-6634 discloses a technique for manufacturing a seat including a seat pan frame, a cushion body, and a skin in a single step by adopting a luskin structure.

However, when the skin of a vehicle seat is formed using such a vinyl-based material or a polyurethane resin material, the body, clothes, or accessories of the occupant come into contact with the skin, and by repeating this, the skin gradually wears. Or torn and easily damaged.

Further, unlike chairs used indoors, vehicle seats are required to have severe weather resistance because they are easily affected by direct sunlight and outside air. Is a thermoplastic resin, so that it is inferior in heat resistance, low in tensile strength and tear strength, and inferior in cold resistance. Further, a sheet having a reduced skin tensile strength and tear strength is susceptible to physical abrasion and tear caused by the movement of the occupant, and is inferior in durability including the cold resistance.

Further, for example, in the case of a seat in which a cushion body and a skin are simultaneously formed using a polyurethane resin material, it is necessary to increase the thickness of the cushion body in order to obtain a cushioning property satisfactory to the occupant. However, there is a problem in that the layer thickness of the skin must be reduced, and the strength of the skin decreases, which is not preferable. In this case, if an attempt is made to secure the strength by increasing the thickness of the skin, the cushioning property is impaired, which is another disadvantage.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a vehicle seat excellent in cushioning property and durability and inexpensive in manufacturing cost, and a method of manufacturing the same. The purpose is to:

[0010]

In order to solve the above-mentioned problems, a vehicle seat according to the present invention is a vehicle seat comprising a frame, a cushion body supported by the frame, and a skin covering the cushion body. The outer skin is formed from a urea resin material.

The skin formed of the urea resin material is less deteriorated with time due to release of the plasticizer, has good heat resistance because it is not thermoplastic, and deteriorates with time in cold air due to its inherently high elongation and tear strength. And has a characteristic of high tensile strength. For this reason, even if it is used for a long period of time, there is little deterioration and excellent durability, and physical strength is high. On the other hand, the skin made of a urea resin material has a high level of strength as described above, so that the thickness of the skin can be made thinner than conventional ones, so that the seat has excellent cushioning properties, and the occupant has a comfortable sitting comfort. Can be obtained. The thickness of the skin is in the range of 0.5 to 2.0 mm, and more preferably in the range of 0.7 to 1.3 mm. In the case where the seat cushion, the seat back and the headrest are manufactured in different processes, one of them may be replaced with a material other than the urea resin material, if necessary.

Further, the vehicle seat according to the present invention is characterized in that the cushion body is formed of a foamable urea resin material, and the foamable urea resin material itself forms a skin.

As a result, the cushion body and the skin are integrally formed, and a more durable vehicle seat can be obtained. Also in this case, one of the seat cushion, the seat back and the headrest may be replaced with a material other than the urea resin, if necessary.

In the method for manufacturing a vehicle seat according to the present invention, when the skin is formed in advance, a seat molding die defining at least a cavity corresponding to the shape of the cushion body by the upper mold and the lower mold is used. Using, a skin is formed by spraying a urea resin material on the lower mold in advance, and then at least a urea resin skin is formed by injecting a foamable resin into the cavity by clamping the upper mold and the lower mold. It is characterized in that the cushion body and the cushion body are integrally formed.

In the method for manufacturing a vehicle seat according to the present invention, when the cushion main body and the skin are integrally formed at the time of foam molding, an upper mold and a lower mold define at least a cavity for molding the cushion main body. Then, a foamable urea resin material is injected into the cavity, the foamable urea resin material is allowed to react and harden, and after a lapse of a predetermined time, the cushion body and the skin are molded from the cavity with the cushion portion formed of the urea resin material. It is characterized by obtaining.

By using these manufacturing methods, the cushion and the cushion can be obtained by integrally forming the skin and the cushion body with one mold, and the vehicle seat according to the present invention can be efficiently and inexpensively manufactured. Can be manufactured.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a vehicle seat according to the present invention will be described below in detail with reference to the accompanying drawings and the like, in relation to a manufacturing method thereof. In this embodiment, a seat cushion,
The seat back and the headrest are manufactured in the same method, respectively, in different steps, and then assembled integrally. Here, the seat back integrated with the headrest will be described in detail.

As shown in FIGS. 1 and 2, the seat back 2 according to the first embodiment basically includes a cushion 4 and a frame 6 for supporting the cushion 4.
Consists of The cushion portion 4 includes a cushion body 8 formed by foaming and a skin 10 made of a solidified urea resin material and covering the surface of the cushion body 8.

The lower mold 12 for the seatback molding die for manufacturing the seatback 2 configured as described above is:
As schematically shown in FIG. 3, a cavity corresponding to the shape of the cushion portion 4 constituting the seat back 2 is provided, and a urea resin material is sprayed on the surface of the lower mold 12 to form a skin 10.
To form Here, the thickness of the skin 10 is about 1 m.
However, if it is within the range of 0.5 to 2.0 mm, it is empirically comfortable for the occupant, and more preferably, it can be used within the range of 0.7 to 1.3 mm. 2. Thickness
If the thickness is more than 0 mm, the sitting comfort when the occupant is seated is poor, and if the thickness is less than 0.5 mm, the occupant is likely to be torn by accessories or the like in some cases.

With respect to the urea resin material used for spraying to form the skin 10, the types of the main component and the hardener component and the mixing conditions are shown in Table 1.
As a main component having an isocyanate group at a terminal, a polyether polyol having a number of functional groups of 2 and a molecular weight of about 4000 (Example 1), a polyether polyol having a number of functional groups of 2 and a molecular weight of about 4000 and a polyether polyol having a number of functional groups of 2 and a molecular weight of 2 About 2
2,000 polyether polyols (Example 2), a polyester polyol having 2 functional groups and a butylene adipate group having a molecular weight of about 2000 (Example 3), and a polybutylene adipate group having 2 functional groups and a molecular weight of about 2000. A mixture of a polyester polyol having a functional group of 2 and a polyester polyol having an ethylene butylene adipate group having a molecular weight of about 2,000 and having a molecular weight of about 2,000 (Example 4), containing isophorone diisocyanate (IPDI) and a diluent; An additive component mainly composed of a catalyst was used under the blending conditions shown in Table 1, and isophorone diamine (IPDA) was used as a curing agent component.
A diluent and a catalyst were used under the compounding conditions shown in Table 1 for an amine compound mainly composed of In addition, regardless of the conditions of the above examples, the number of functional groups is 2 as a polyether polyol.
3, a polyester polyol having a molecular weight of 400 to 6000 can be used, and a polyester polyol having a functional group number of 2 to 2.3 and a molecular weight of 500 to 2,000 can be used. In each of the examples, good results were obtained with respect to tensile strength, elongation at break, and tear strength, which are physical properties of the resin after curing.

[0021]

[Table 1]

In Table 1, the diluent is toluene,
It is a mixture of xylene, isopropyl alcohol and ethyl acetate. The unit of the blending amount of the main component and the curing agent component is part by weight, and the unit of the physical property after curing is a tensile strength of N.
/ Cm ² , elongation at break%, tear strength N / cm,
The physical properties after curing are values under the conditions of 50 parts by weight of the diluent and 0.3 parts by weight of the catalyst.

As shown in FIG. 4, the preformed synthetic resin frame 6 is set on the upper die 16. Next, the upper mold 16 is moved toward the lower mold 12 so as to be displaced, and the mold 18 is closed. In FIG. 4, reference numeral 20 denotes a resin injection device provided at an end of the upper die 16.

Next, as shown in FIG. 5, a polyurethane resin is selected and used as a material for forming the cushion body 8. That is, the molecular weight of the main component is about 5,000.
50 parts by weight of a polyether polyol having a molecular weight of about 60
Using a mixture of 40 parts by weight of the graft polyol of No. 00,
0.5 part by weight of a catalyst and 1.0 part by weight of a foam stabilizer are added thereto. As a curing agent component, a mixture of 60 parts by weight of diphenylmethane diisocyanate (MDI) and 40 parts by weight of tolylene diisocyanate (TDI) was used, and the molar ratio of OH / NCO was 1.0. In addition, water is used as the blowing agent, in which case the water reacts with the isocyanate groups and the resulting acid is decomposed to release carbon dioxide and form bubbles. As shown in FIG. 5, the material blended under the above conditions is injected into the cavity defined in the mold 18 from the resin injection device 20 and foamed in the cavity. Thereby, the frame 6 and the skin 10
The foaming action is carried out between the above and the cushion main body 8 is formed. After a predetermined time (about 1 to 2 minutes) elapses and solidifies by cooling, the upper mold 16 is separated from the lower mold 12 to take out the seat back 2 in which the skin 10, the cushion body 8 and the frame 6 are integrally formed. (See FIG. 6). A vehicle seat is completed by attaching a seat cushion manufactured in a separate process (not shown).

Next, in the second embodiment, when the cushion portion 4 is formed using a urea resin material, a method in which the cushion main body 8 and the skin 10 made of the urea resin material are integrally formed, a so-called method. The method for forming the integral skin will be described below.

The urea resin material for forming the integral skin was formulated under the following conditions. That is, polyether polyol 70 having a number of functional groups of 2.5 to 3.0 and a molecular weight of 4000 to 6000 as a main component.
90 parts by weight, 0 to 20 parts by weight of a polyoxypropylene amine having a number of functional groups of 2 and a molecular weight of 2,000, 5 to 15 parts by weight of a polyoxypropylene amine having a number of functional groups of 2 and a molecular weight of 230 to 400, and Freon 141B10. To 15 parts by weight, pure water 0 to 0.1 parts by weight, and AC-398 manufactured by Jefferson Chemical Co. as a curing accelerator.
5 parts by weight and KL-No. 1 and 0.02 parts by weight of a coloring agent, and 0 to 3.0 parts by weight of a colorant, and 100 to 0 parts by weight of a polymeric MDI as a curing agent and a monomeric MDI 0 to 145 to 180 equivalents of an amine.
100 parts by weight. The curing agent OH / NCO
Is 0.9 to 1.1.

The manufacturing process of the seat back in this case is performed as follows. In other words, the material is
It is injected into the mold 18 warmed to 0 ° C. When the foaming reaction and the curing reaction proceed at the same time, the curing reaction proceeds relatively quickly in the portion of the urea resin material that is in contact with the lower mold 12 of the mold 18 and corresponds to the skin 10 having a low foaming ratio. A part is formed. Thereby, the skin 10 is formed on the inner surface of the mold.
Is solidified, and at the same time, the cushion body 8 is integrally solidified. Therefore, in the first embodiment, the step of spraying the urea resin material onto the lower mold 12 shown in FIG. 3 can be omitted. That is, after closing the mold 18 with the frame 6 fixed in the cavity (see FIG. 4), a step of injecting the urea resin material into the mold 18 may be performed. In this case, the frame 6 may be fixed to the upper die 16 or the lower die 12 in advance, as in the first embodiment.

Next, in Comparative Example 1, the skin 10 was previously formed on the lower surface of the mold 18 as in the first embodiment.
The seat back 2 was molded using a foamable urethane resin material instead of the urea resin material as the skin material.

Further, in Comparative Example 2, the skin forming method employed in the first embodiment was used, a vinyl chloride resin material was used as the skin material, and a foamable urethane resin material was used as the cushion body material. Seat back 2
Was molded.

Table 2 shows the results of evaluating the basic physical properties of the skin of each vehicle seat manufactured by the above method. Table 2
In the middle, the embodiment is an evaluation of the skin 8 made of the urea resin material according to the first embodiment, and the comparative example 2-1 uses the vinyl chloride resin material and performs the skin only by one molding. In Comparative Example 2-2, after a vinyl chloride resin material was adhered as a thin layer on the mold surface, excess resin was discharged, cooled, and the resin was solidified to obtain a skin layer. The processing method is used.

[0031]

[Table 2]

The skin 8 of the seat back 2 according to the first embodiment has remarkably excellent tensile strength and tear strength, a good elongation at break, and a required modulus as compared with the comparative examples. Have been. In addition, it turned out that the tensile strength and the tear strength of the skin made of the vinyl chloride resin material formed by the slash processing method of Comparative Example 2-2 are lower than those of Comparative Example 2-1.

As described above, the skin of the sheet according to the present embodiment is excellent in tensile strength, tear strength and elongation at break, so that the thickness of the skin can be reduced. It is possible to obtain an excellent vehicle seat.

[0034]

As described above, the vehicle seat according to the present invention has a skin made of a urea resin material, and has high tensile strength, tear strength and elongation at break, and a thermosetting resin material. For this reason, it is superior in heat resistance and the like as compared with a thermoplastic resin material. The urea resin material used for forming the skin is less expensive than other materials.

As a result, the thickness of the cushion body can be increased by reducing the thickness of the skin, so that a vehicle seat having excellent cushioning properties, excellent weather resistance and durability, and low production cost can be obtained. Can be.

Further, in the vehicle seat according to the present invention, the cushion body is made of a foamable urea resin material, and forms a skin itself. As a result, it is possible to obtain a vehicle seat in which the cushion body and the skin are integrally formed, which has high durability, is lightweight, and has a lower manufacturing cost.

Further, in the method of manufacturing a vehicle seat according to the present invention, a skin is formed by spraying a urea resin material on a lower mold of a mold in advance, and then the upper mold and the lower mold are clamped. By injecting the foamable resin into the cavity, at least the urea resin skin and the cushion body are integrally formed.

Further, in the method of manufacturing a vehicle seat according to the present invention, a foamable urea resin material is injected into the cavity, and after a predetermined time has elapsed, the cushion body and the skin are integrally formed of the urea resin from the cavity. Obtained cushion part.

Therefore, according to these vehicle seat manufacturing methods, the cushion portion can be formed by integrally forming the skin and the cushion body with one mold, and the vehicle seat according to the present invention can be efficiently manufactured. It can be manufactured efficiently and at low cost.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram for explaining a cushion portion and a frame constituting a seat back of a vehicle body seat according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of a frame constituting the seat back shown in FIG.

FIG. 3 is a conceptual diagram for explaining a step of forming a skin in advance on a lower mold of a seatback molding die in the method of manufacturing a vehicle body sheet according to the present invention.

FIG. 4 is a conceptual diagram for explaining a step of setting a preformed frame in an upper mold of a mold in a method of manufacturing a vehicle body sheet according to the present invention.

FIG. 5 is a conceptual diagram for explaining a step of forming a cushion main body by a foam molding method in a method of manufacturing a vehicle body sheet according to the present invention.

FIG. 6 is a conceptual diagram for explaining a step of releasing a mold after forming a seat back in the method of manufacturing a vehicle body seat according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 2 ... Seat back 4 ... Cushion part 6 ... Frame 8 ... Cushion body 10 ... Skin 12 ... Lower mold 16 ... Upper mold 18 ... Mold 20 ... Resin injection device

Claims (5)

[Claims] 1. A vehicle seat comprising a frame, a cushion body supported by the frame, and a skin covering the cushion body, wherein the skin is formed of a urea resin material. 2. The vehicle seat according to claim 1, wherein the cushion main body is formed of a foamable urea resin material, and the foamable urea resin material forms a skin by itself. 3. The vehicle seat according to claim 1, wherein the thickness of the skin is 0.5 to 2.0 mm. 4. A method for manufacturing a vehicle seat comprising a frame, a cushion main body and a skin, wherein a sheet forming die for defining at least a cavity corresponding to a shape of the cushion main body by an upper die and a lower die is used. A skin is formed by spraying a urea resin material on the lower mold in advance, and then at least a urea resin skin and a cushion body are formed by clamping the upper mold and the lower mold and injecting a foamable resin into the cavity. A method for manufacturing a vehicle seat, comprising: 5. A method for manufacturing a vehicle seat comprising a frame, a cushion body and a skin, wherein a cavity for molding at least the cushion body is defined by an upper mold and a lower mold, and a foamable urea resin material is filled in the cavity. Inject,
A method for manufacturing a vehicle seat, comprising: reacting and curing the foamable urea resin material; and obtaining a cushion portion in which a cushion body and a skin are formed of urea resin from the cavity after a predetermined time.