JP2000038139A - Steering wheel and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve moldability and to prevent a step from being generated by a joint on the surface by integrally molding a surface material laminated with a decorative material and a resin reinforcing layer, a resin core material and a mandrel. SOLUTION: A preliminarily molded decorative material 5 is arranged in a die, a resin is filled between the decorative material 5 and the die to form a resin reinforcing layer 6, and a surface material 4 is obtained. Dies with different inner face shapes are used for the surface material 4 for the surface side and the surface material 4 for the back side respectively. The surface material 4 for the surface side and the surface material 4 for the back side are arranged in the cavity of a die, and a mandrel 2 is arranged near the center of the cavity. A foaming urethane resin is filled between the resin reinforcing layer 6 of the surface materials 4 and the mandrel 2 to form a resin core material 3. A molded body integrated with the surface materials 4 and the resin mandrel 2 is obtained, the molded body is taken out of the die, and the joint of the surface materials 4, 4 is finished to obtain a steering wheel 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering wheel having a decorative material on its surface, which is formed by first molding a surface material, filling the inside of the surface material with a resin, joining the resin to a metal core, and integrating it. Things and their manufacturing methods.

[0002]

2. Description of the Related Art The present applicant has previously disclosed a method of manufacturing a steering wheel having a wood grain pattern as disclosed in Japanese Unexamined Patent Publication No. Hei 8-3104.
No. 07 has proposed a method. In this method, for example, as shown in FIG. 8, a wooden surface material 21 made of a wooden decorative material is bent and preliminarily formed. This is a method in which the steering wheel is integrally formed by filling a resin between the core metal 22 and the resin core material 23. Alternatively, for example, as shown in FIG. 9, the wooden surface material 21 is bent and preliminarily formed, placed in a mold 20, and filled with resin to form a resin core material 23. The split molded body 2 of the steering wheel
4 and then, as shown in FIG.
There is also described a method of manufacturing a steering wheel by bonding and integrating one another with a cored bar 22 interposed therebetween.

[0003]

However, in the method of integrally forming the steering wheel as shown in FIG. 8, since the shape accuracy and strength of the preformed wooden surface material 21 are small, this method is difficult. There is a problem that it is difficult to set the surface material 21 on the mold 20 and the moldability is extremely poor. In addition, in the method of bonding the divided molded bodies 24 as shown in FIGS. 9 and 10, in addition to the problem of the moldability similar to the above, it is not easy to manufacture the divided molded bodies 24 with high dimensional accuracy. As shown in FIG.
There is also a problem that a step is likely to occur at a joint between the two.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to improve formability when manufacturing a steering wheel having a decorative material on a surface and to prevent a step from being formed on a surface by a seam. With the goal.

[0005]

In order to solve the above-mentioned problems, a steering wheel according to the present invention comprises a surface material formed by laminating a decorative material and a resin reinforcing layer, a resin core material, and a core metal. It is characterized by being integrally molded.
Further, the method of manufacturing a steering wheel of the present invention includes a step of forming a resin material inside the mold after preliminarily forming a decorative material, filling the inside thereof with a resin to form a resin reinforced layer, and obtaining a surface material. The method is characterized by including a step of forming a resin core material by filling a resin between the metal core and the core metal.

Further, the steering wheel according to the present invention is characterized in that a surface material formed by laminating a decorative material and a resin reinforcing layer, and a plurality of divided molded bodies and a metal core integrally formed with a resin core material are joined and joined. It is characterized by being integrated. It is preferable that the joining surfaces of the plurality of divided molded bodies are formed in a shape to be engaged or fitted to each other.
Further, the manufacturing method of the steering wheel of the present invention comprises a step of obtaining a surface material by forming a resin reinforcing layer by filling a resin inside the mold after preliminarily forming a decorative material and then disposing the resin in the mold, The method is characterized by comprising a step of forming a resin core material by filling a resin inside, to obtain a divided molded body, and a step of joining and integrating a plurality of divided molded bodies together with a core metal.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments will be described in order to make the present invention easier to understand. Such an example is
It shows one embodiment of the present invention and does not limit the present invention. It can be arbitrarily changed within the scope of the present invention.
FIG. 1 is a partially cutaway plan view showing an example of the steering wheel of the present invention. In FIG. 1, reference numeral 1 denotes a steering wheel, which includes a rim portion 1a and a spoke portion 1b. This steering wheel 1 is roughly composed of a metal core 2 made of a rod-shaped or pipe-shaped metal, a resinous core material 3 and a surface material 4. It is obtained by laminating a resin reinforced layer 6. Also, of the front side and the back side of the steering wheel 1 with respect to the surface passing through the metal core 2, the rim portion 1a on the back side is preferably formed with unevenness of the grip.

[0008] Such a steering wheel 1 is manufactured as follows. Hereinafter, a first embodiment of a method for manufacturing a steering wheel according to the present invention will be described. First, the decorative material 5 is preliminarily formed by performing a curved surface processing. This makes the cosmetic material 5
Is formed to a state close to the surface shape of the steering wheel 1, but does not necessarily have to match the final shape. Also, a cosmetic material 5 on the front side of the steering wheel 1
And the decorative material 5 to be the back side are respectively preformed. At this time, the same mold may be used for the front side and the back side, or the preforming of the decorative material 5 for the back side may have unevenness of the grip. This may be performed using a mold.

Materials for the decorative material 5 include (1) a three-layer decorative material in which a wooden veneer is laminated on both sides of a thin metal plate, (2) a backing decorative material in which a wooden veneer is lined with a backing material, and (3) A laminated veneer made of one or more layers of wood veneer, (4) a veneer / resin composite material obtained by laminating a wood veneer and a resin thin plate, and (5) a printed pattern applied to a non-woody material. Film materials, etc., can be appropriately selected and used. FIG. 2 shows the decorative material 5
(1) An example in which a three-layer decorative material is preliminarily molded using a three-layer decorative material is shown in (a) a plan view, and (b) is a cross-sectional view taken along line BB in (a).

[0010] Specifically, (1) a three-layer decorative material in which a wooden veneer 5b serving as a surface layer design and a wooden veneer 5c serving as an inner layer are integrally bonded to both surfaces of a thin metal plate 5a by bonding. Is used. The metal thin plate 5a needs to have flexibility and strength to reinforce the wooden veneers 5b and 5c laminated on both sides, and the thickness is selected depending on the metal used. For example, in the case of an aluminum thin plate, one having a thickness of 0.01 to 0.50 mm is preferably used, and a more preferable thickness is 0.05 to 0.20 mm. Wooden veneers 5b, 5 laminated on both sides of a thin metal plate 5a
Although c may be the same, it is particularly desirable that the surface layer has a beautiful grain pattern. The thickness of these wooden veneers 5b and 5c is preferably 0.15 to 1.00 mm. Metal sheet 5
The adhesive used for bonding the a to the wooden veneers 5b and 5c is not particularly limited, but since the three-layer decorative material, that is, the resin-reinforced layer 6 is insert-molded inside the decorative material 5, it is preferably used. It is preferable to perform pressure and heat bonding using a heat-resistant thermosetting adhesive. As the material of the metal sheet 5a, aluminum-based alloy, magnesium, magnesium-based alloy, titanium, titanium-based alloy, copper, copper-based alloy, iron, iron-based alloy, brass, or stainless steel can be used in addition to aluminum. .

(2) The backing decorative material has a thickness of 0.15
A wood veneer of ~ 1.00 mm backed by a backing material such as Japanese paper or a nonwoven fabric of chemical fiber can be preferably used. When such a backing decorative material is used, it is preferable to apply a primer to the back surface, thereby improving the adhesion of the resin reinforcing layer formed on the back surface of the decorative material 5 to the resin material in a later step. Can be done. Acrylic resin, epoxy resin, urethane resin or the like can be preferably used as the primer. A thermoplastic resin compatible with the resin material of the resin reinforcing layer may be added to the primer. Primer thickness is 20-100
It is preferably about μm.

(3) As a laminated single plate, 0.15 to 1.0
Although a 0 mm wooden veneer may be used alone, a plywood in which one or more wooden veneers are laminated on the back surface of a wooden veneer may be used. The laminated veneer has a thickness of 0.15 to 3.00 mm
When the thickness is smaller than this, the shape retention after molding is deteriorated, and it is difficult to stably dispose the surface material 4 in the mold 7 in a later step, and wrinkles may be generated. On the other hand, if the thickness is more than 3.0 mm, the moldability is deteriorated. In addition, a step of obtaining a laminated veneer by laminating and integrating a plurality of wooden veneers and a step of preforming the laminated veneer can be performed simultaneously. (4) As a veneer / resin composite material, 0.15 to 1.00
0.10 to 3.00 mm thick on the back of a 1 mm wooden veneer
Adhered resin thin plates are preferably used. As the material of the resinous thin plate, polyphenylene sulfide (PPS), polycarbonate (PC), ABS resin, or the like is preferable, and a material having compatibility with the resin reinforcing layer 6 formed on the back surface of the decorative material 5 in a later step is preferable. Used selectively. (5) As the film material, a material obtained by printing or the like on a surface of a plastic film, a material having a design property such as a carbon fiber woven fabric film, or the like can be preferably used.

The preliminary forming of the decorative material 5 is preferably performed by a hot press or a vacuum press. The hot pressing conditions are preferably 80 to 140 ° C. for about 1 to 5 minutes,
The vacuum pressing conditions are preferably 80 to 140 ° C. and 1 to 1
It is about 0 minutes. In addition, vacuum forming and compressed air pressure forming can also be used. In addition, prior to the preforming of the decorative material 5, if the humidifying treatment by a known method or an alkali treatment using ammonia is appropriately performed, the decorative material 5 can be obtained.
Can be softened, preventing cracking during curved surface processing,
It is effective for improving moldability.

Next, a resin material reinforced layer 6 is formed inside the molded decorative material 5 by insert molding as described below to obtain the surface material 4. First, a molding die 7 as shown in FIG. 3 is prepared in advance. The mold 7 is an openable upper mold 7a.
And the lower mold 7b, and the inner shape of the cavity 8 of the lower mold 7b is formed to be equal to the outer shape of the steering wheel 1. In this embodiment, the inner surface shape of the cavity 8 is different between the molding die 7 for the front side of the steering wheel 1 and the molding die 7 for the back side.
On the inner surface of the cavity 8 of the molding die 7 for the back side, grip irregularities are formed. In addition, the lower mold 7 of the upper mold 7a
A projecting portion 9 having a semicircular cross section obtained by dividing the outer shape of the resin core material 3 into two is formed on the joint surface with b. The projection 9 is formed so as to be located at the center of the opening of the cavity 8 when the upper mold 7a and the lower mold 7b are closed. Then, the formed decorative material 5 is arranged in the cavity 8 of the molding die 7, the upper die 7a is closed, and the decorative material 5 and the upper die 7 are closed.
Resin is filled between the protrusion 9a and the resin reinforcing layer 6 by insert molding. At this time, the decorative material 5 is formed into a shape along the inner surface shape of the cavity 8 by the injection molding pressure.

As the material of the resin reinforcing layer 6, (1) polyphenylene sulfide (PPS), (2) polycarbonate (PC), and (3) ABS resin are preferably used.
Further, these resins may be filled with glass fibers, carbon fibers, aramid fibers, whiskers, or the like as fillers in an amount of about 0 to 70% by weight. Regarding the basic physical property values of the resin reinforced layer 6, if the flexural strength and Young's modulus are too small, the overall rigidity is reduced. If the flexural strength and Young's modulus are too large, the workability during molding may be adversely affected. ~ 3
00 MPa, more preferably about 150 to 250 MPa, and Young's modulus is preferably about 10 to 25 GPa, more preferably about 15 to 20 GPa. If the coefficient of linear expansion is large, it will be deformed under high temperature, so it may be 0, but preferably 0 to 8 × 10 ⁻⁵ / ° C., more preferably 0.
About 5 × 10 ⁻⁵ / ° C. (1) Preferable molding conditions when using polyphenylene sulfide (PPS) are cylinder temperatures of 280 to 320
° C, mold temperature 80-160 ° C, injection pressure 30-100M
Pa. (2) When polycarbonate (PC) is used, preferable molding conditions are a cylinder temperature of 270 to 330 ° C, a mold temperature of 80 to 130 ° C, and an injection pressure of 70 to 150 MPa. (3) When using ABS resin, preferable molding conditions are cylinder temperature 150 to 250 ° C. and mold temperature 50 to 100.
° C and an injection pressure of 70 to 150 MPa.

Next, a resin core material 3 is formed by filling the inside of the surface material 4 constituting the front side and the surface material 4 constituting the back side obtained as described above to form a resin core material 3. Get. When the resin for the resin core material 3 is filled, the surface material 4 may be arranged in a mold, or the surface material 4 may have rigidity and deform without filling even if there is no mold. If it does not occur, a mold need not be used. At the same time that the resin core 3 is formed, the resin core 3 and the metal core 2 are integrated. That is, first, a molding die 10 as shown in FIG. 4 is prepared in advance. Mold for molding 10
Is composed of an upper mold 10a and a lower mold 10b that can be freely opened and closed. Although the inner surface shape of the cavity 11 does not necessarily have to match the outer surface shape of the steering wheel 1, the front surface material 4 and the rear surface material 4 disposed in the cavity 11 can be pressed. It is necessary. on the other hand,
A core 2 is prepared. The metal core 2 is formed using a metal rod or a metal pipe, and it is preferable that the rim portion 1a and the spoke portion 1b are formed integrally.

Then, as shown in FIG.
The molded surface material 4 on the front side and the surface material 4 on the back side are arranged in the cavity 11 of the “0”, and the metal core 2 is arranged so as to be located at the center of these. Then, a resin is filled between the surface materials 4 and 4 and the metal core 2 to form the resin core material 3 and integrate the metal core 2. As a material of the resin core material 3, a foamable resin such as a foamed urethane resin or a foamed epoxy resin is preferable, and about 0 to 70% by weight of carbon fiber or glass fiber may be filled as a filler in these resins. . Preferred molding conditions for molding the resin core material 3 using these foamable resins are 20 to 150 ° C. and 3 to 60 ° C.
Minutes. Then, the molded body for a steering wheel obtained in this manner is taken out of the mold 10, and the seam between the two surface materials 4, 4 is finished with paper or the like, and then subjected to coloring, painting, polishing or the like as necessary. Thereby, the steering wheel 1 as a final product is obtained.

Regarding the basic physical property values of the resin core material 3, if the density is too low, the strength is insufficient, and if the density is too high, molding failure occurs, so it is preferably 0.1 to 0.5 g / cm ³ , more preferably It is about 0.1 to 0.3 g / cm ³ . If the bending strength is too small, the core metal 2 cannot be held, and if it is too large, the expansion force generated at the time of heating increases, so that the bending strength is preferably 0.5 to 1.5 MPa, more preferably 0.7 to 1.5 MPa.
It is about 1.2 MPa. If the coefficient of linear expansion is large, the resin reinforced layer may be deformed.
Preferably it is 0-6 × 10 ^-5 / ° C, more preferably 0-4.
It is about ^10-5 / ° C.

The resin core material 3 may be made of a thermosetting resin such as urethane resin, phenol resin, thermosetting polyester, polyphenylene sulfide (PPS), polycarbonate (P
C), ABS resin, polyetherimide (PEI), polypropylene (PP), polyethylene (PE), acrylic resin (AC), polyetheretherketone (PEE)
Thermoplastic resins such as K), polyvinyl chloride (PVC), and nylon can be used. Further, these resins may be filled with glass fibers, carbon fibers, aramid fibers, whiskers, or the like as fillers in an amount of about 0 to 70% by weight.

In this embodiment, the shape of the surface material 4 composed of the decorative material 5 and the resin reinforcing layer 6 is formed by dividing the steering wheel 1 into two parts by the surface passing through the metal core 2.
As shown in (a), seams 12, 12 of the surface materials 4, 4
Is located on the plane P passing through the metal core 2,
The positions of the seams 12, 12 are not limited to this. For example, it may be configured as shown in FIGS. FIG.
In the example of (b), the shape of the surface material 4 is formed such that the front surface material 4 is larger than the back surface material 4, and the seams 12, 12 are located on the back side of the surface P. Is configured. It is preferable in terms of appearance that the seams 12, 12 are located on the back side in this manner. In the example of FIG. 5C, the end faces of the two surface materials 4 and 4 are formed in a tapered shape, and the seams 12 and 12 are formed by abutting the end faces. In this way, the strength at the joint between the front and back surface members 4, 4 is increased.

The steering wheel 1 manufactured as described above includes a decorative material 5 in which the surface material 4 has a surface design,
Since it is composed of two layers of the resin reinforcing layer 6 on the inner side, the shape accuracy and strength of the molded surface material 4 are improved.
Therefore, the conventional problem that it is difficult to set the surface material 4 in the mold in the step of forming the resin core material 3 is solved, the moldability is improved, and the workability is improved. If the rigidity of the surface material 4 is further increased, the resin core material 3 can be formed without using a mold. Further, since the resin reinforcing layer 6 is not provided conventionally, the shape accuracy and strength of the surface material 4 are low, and the displacement of the surface material 4 and the formation of the resin core material 3 in the process of forming the resin core material 3 are reduced. Defects, such as resin run-out, are likely to occur, and the yield rate is 50.
%, The present embodiment improves the shape accuracy and strength of the surface material 4, thereby suppressing the occurrence of the above-mentioned defects and improving the non-defective rate to about 80%. Can be. Further, according to the manufacturing method of this embodiment, the surface material 4, the resin core material 3 and the metal core 2 can be integrated simultaneously with the molding of the resin core material 3, so that the number of steps is small and the production efficiency is good. In addition, since no complicated work is required, the production is easy and suitable for mass production. The combination of the material of the decorative material 5, the preforming method, the material of the resin reinforcing layer 6, and the material of the resin core material 3 is not particularly limited and is arbitrary.

Next, a description will be given of a second embodiment of the method for manufacturing a steering wheel according to the present invention. This embodiment is significantly different from the first embodiment in that when forming the resin core 13, the steering wheel 1 is divided into two front and rear sides, each of which is formed into a divided molded body 18. The point is that these divided molded bodies 18 are joined and integrated. First, the decorative material 5 is preformed in the same manner as in the first embodiment.
The same material as in the first embodiment can be used as the material of the decorative material 5.

Next, as shown in FIG. 6A, the resin reinforced layer 16 is formed inside the formed decorative material 5 by insert molding.
To form the surface material 14. At this time, a molding die for the front side and a molding die for the back side formed such that the inner surface shape of the cavity is equal to the outer surface shape of the front side and the back side of the steering wheel 1 are used as the molding dies, On the inner surface of the back side cavity, unevenness of the grip is formed. Also, after molding, a concave portion 17a and a convex portion 17b which engage with each other are respectively formed on the joint surface between the resin reinforced layer 16 of the surface material 14 on the front side of the steering wheel 1 and the resin reinforced layer 16 of the surface material 14 on the back side. Preferably, it is formed. The resin material forming the resin reinforced layer 16, the basic physical properties of the resin reinforced layer 16, and the molding conditions are the same as those of the resin reinforced layer 6 in the first embodiment.

Next, as shown in FIG. 6 (b), the obtained surface material 14 on the front side and the surface material 14 on the back side are arranged in a mold, respectively, and the inside thereof is filled with a resin to form a resin core material. 1
3 is formed, and a front split molding 18 and a rear split molding 18 are produced. At this time, the divided molded body 1
A groove 18a for accommodating the cored bar 2
Is formed. The material, molding conditions, and basic physical properties of the resin core 13 are the same as those of the resin core 3 in the first embodiment.

The front-side divided molded body 18 and the back-side divided molded body 18 obtained as described above are inserted into the grooves 18a by disposing the cored bar 2 and forming the recesses formed in the joint surface. The two divided molded bodies 18 and the cored bar 2 are joined and integrated by engaging the projections 17a with the projections 17b.
Preferably, these integrations are performed using an adhesive.
Further, as the core metal 2, a rim portion 1 a and a spoke portion 1 b are integrally formed in advance as in the case of the first embodiment, or the rim portion may be used when adhering to the divided molded body 18. 1a and the spoke portion 1b may be bonded. Thereafter, the joint between the two divided molded bodies 18 is finished with paper or the like, and then, if necessary, colored, painted, polished, or the like, thereby obtaining the steering wheel 1 as a final product.

According to this embodiment, the surface material 14 is composed of the decorative material 5 serving as the surface layer design and the resin reinforcing layer 16 inside the decorative material 5, so that the shape accuracy and the shape of the molded surface material 14 can be improved. Strength is improved. Therefore, the resin core 13
The conventional problem that it is difficult to set the surface material 14 in the mold in the step of forming the slab is solved, the moldability is improved, and the workability is improved. If the rigidity of the surface material 4 is further increased, the resin core material 3 can be formed without using a mold. In addition, since the shape accuracy and strength of the molded surface material 14 are improved, the dimensional accuracy of the divided molded bodies 18 is increased, and generation of a step at a joint between the divided molded bodies 18 is prevented. Further, in this embodiment,
The concave portion 1 engaging with the joint surface of the divided molded bodies 18 with each other
Since the projections 7a and the projections 17b are formed, the divided molded bodies 18 are joined with high precision.

In this embodiment, the resin reinforced layer 16
Although the concave portion 17a and the convex portion 17b are provided on the joint surface between them, such a concave portion 17a and the convex portion 17b may be provided on the joint surface between the resin core members 13 or the resin reinforcing layer 16 and the resin core. It may be provided on both of the members 13.
Further, the shapes of the concave portion 17a and the convex portion 17b are not limited to those of the present embodiment, and can be appropriately changed as long as they engage with each other. In addition, for example, a shape that can be fitted as shown in FIG. 7 may be used. In this case, the divided molded bodies 18 can be integrated without using an adhesive, and the appearance is poor due to the protrusion of the adhesive. Generation can be prevented. Also in this embodiment, the material of the decorative material 5, the preforming method, the material of the resin reinforcing layer 16, and the resin core material 13
The combination of the materials is not particularly limited and is optional.

[0028]

EXAMPLES Hereinafter, the effects of the present invention will be clarified by showing specific examples. (Example 1) As a decorative material 5, on both sides of an aluminum thin plate having a thickness of 0.1 mm, a wooden veneer having a thickness of 0.2 mm serving as a surface layer design and a wooden veneer having a thickness of 0.2 mm serving as an inner layer. Were prepared to prepare a three-layered decorative material. First, cosmetic material 5
Was subjected to a curved surface processing by a hot press and preformed. The hot pressing conditions at this time were 140 ° C. for 3 minutes. Next, the formed decorative material 5 is placed in the lower mold 7b of the mold 7 shown in FIG.
The upper mold 7a is closed, a resin is filled between the decorative material 5 and the upper mold 7a, insert molding is performed, and the resin reinforcing layer 6 is formed.
Was formed, and a surface material 4 was obtained. The resin to be filled is P
A product obtained by adding 30% by weight of carbon fiber to PS (Fortron 2130A1 manufactured by Polyplastic Co., Ltd.) was used. The molding conditions were a cylinder temperature of 320 ° C., a mold temperature of 110 ° C., and an injection pressure of 70 MPa. The surface material 4 for the front side and the surface material 4 for the back side used molding dies 7 having different inner surface shapes, and the back surface material 4 was formed with grip irregularities. The bending strength of the resin-reinforced layer 6 in the obtained surface material 4 was 280 MPa, the Young's modulus was 20 GPa, the coefficient of linear expansion was 0 in the flow direction, and 4.3 × 10 ⁻⁵ / ° C. in the direction perpendicular thereto.

Next, the obtained surface material 4 for the front side and the surface material 4 for the back side are placed in the cavity 11 of the mold 10 shown in FIG.
And the metal core 2 was arranged near the center of the cavity 11. Then, a foamable urethane resin was filled between the resin reinforcing layer 6 of the surface material 4 and the core metal 2, and foamed and cured to form the resin core material 3. The molding conditions were 50 ° C. for 5 minutes, and the density of the formed resin core material 3 was 0.3 g /
cm ³ , flexural strength 1.0 MPa, coefficient of linear expansion 4 × 10 ⁻⁵
/ ° C. Thus, the surface material 4 and the resin core material 3
Is obtained from the mold, and the joint between the surface materials 4 and 4 is finished with paper or the like, and then, if necessary, colored, painted, and polished. The steering wheel 1 was obtained.

Example 2 A steering wheel 1 was manufactured in the same manner as in Example 1 except that PC was used instead of PPS as the resin material of the resin reinforcing layer 6.
That is, the decorative material 5 is preformed in the same manner as in Example 1 above, placed in the mold 7 shown in FIG. 3, filled with resin, and subjected to insert molding to form the resin reinforced layer 6, Surface material 4 was obtained. As the resin to be filled, a resin obtained by adding 30% by weight of carbon fiber to PC was used. The molding conditions were as follows: cylinder temperature 330 ° C, mold temperature 120 ° C, injection pressure 70
MPa. The surface material 4 for the front side and the surface material 4 for the back side used molding dies 7 having different inner surface shapes, and the back surface material 4 was formed with grip irregularities.
The bending strength of the resin reinforced layer 6 in the obtained surface material 4 is 2
50 MPa, Young's modulus is 15 GPa, linear expansion coefficient is 1.3 × 10 ⁻⁵ / ° C. in the flow direction, and 5.2 × in the direction perpendicular to this.
It was 10 ^-5 / ° C. Next, a resin core material 3 was formed using a foamable urethane resin in the same manner as in Example 1 and the surface material 4, the resin core material 3, and the metal core 2 were integrated. Further, the obtained molded body is taken out of the mold, and the surface material 4,
After finishing the joints between the four with paper or the like, the steering wheel 1 was obtained by coloring, painting, polishing and the like as necessary.

Example 3 A steering wheel 1 was manufactured in the same manner as in Example 1 except that ABS resin was used instead of PPS as the resin material of the resin reinforcing layer 6. That is, the decorative material 5 is preformed in the same manner as in Example 1 above, placed in the mold 7 shown in FIG. 3, filled with resin, and subjected to insert molding to form the resin reinforced layer 6, Surface material 4 was obtained. As a resin to be filled, a resin obtained by adding 30% by weight of carbon fiber to an ABS resin was used.
Molding conditions are cylinder temperature 230 ° C, mold temperature 80 ° C,
The injection pressure was 70 MPa. The surface material 4 for the front side and the surface material 4 for the back side used molding dies 7 having different inner surface shapes, and the back surface material 4 was formed with grip irregularities. The bending strength of the resin-reinforced layer 6 in the obtained surface material 4 is 140 MPa, the Young's modulus is 8 GPa, the linear expansion coefficient is 2.8 × 10 ⁻⁵ / ° C. in the flow direction, and 7.0 × 10 ^{5 in the} direction perpendicular thereto. ⁻⁵ / ° C. Then, in the same manner as in Example 1 described above, a resin core material 3 was formed using a foamable urethane resin.
The surface material 4, the resin core material 3, and the core metal 2 were integrated. Furthermore, after taking out the obtained molded body from the mold and finishing the seam between the surface materials 4 and 4 with paper or the like,
The steering wheel 1 was obtained by coloring, painting, polishing and the like as necessary.

(Example 4) The steering wheel 1 was manufactured in the same manner as in Example 1 except that the backing decorative material was used instead of the three-layer decorative material as the material of the decorative material 5. That is, as the decorative material 5, a nonwoven fabric (basis weight: 50 g / cm) was applied to a wood veneer having a thickness of 0.2 mm serving as a surface design.
Those backed by ² ) were used. And this cosmetic material 5
Was subjected to a curved surface processing by a hot press and preformed. The hot pressing conditions at this time were 140 ° C. for 3 minutes. Subsequently, preferably in order to improve the adhesion between the decorative material 5 and the resin reinforcing layer 6, on the nonwoven fabric surface of the molded decorative material 5,
A primer mainly composed of an acrylic resin having a tertiary amine as a functional group and a curing agent of an epoxy resin having a glycidyl group as a functional group was applied and dried. Primer thickness is 3
It was set to 0 μm. Thereafter, in the same manner as in the first embodiment, a resin reinforcing layer 6 is formed inside the decorative material 5 using a resin material obtained by adding carbon fiber to PPS to obtain a surface material 4, and then a foaming material is formed. Core material 3 using urethane resin
The surface material 4, the resin core material 3, and the core metal 2 were integrated. Furthermore, after taking out the obtained molded body from the mold and finishing the seam between the surface materials 4 and 4 with paper or the like,
The steering wheel 1 was obtained by coloring, painting, polishing and the like as necessary.

[0033]

As described above, according to the present invention,
Since the surface material is composed of the decorative material and the resin reinforcing layer, the shape accuracy and strength of the molded surface material are improved. Therefore, it is easy to set the preformed surface material in the mold in the step of forming the resin core material, thereby improving the moldability and the workability. There is also a possibility that a mold is not required in the step of forming the resin core material. In addition, by improving the shape accuracy and strength of the molded surface material, the occurrence of defects such as misalignment of the surface materials and protrusion of the resin constituting the resin core material in the process of forming the resin core material is suppressed, The yield rate is improved.

In the method of molding a plurality of divided molded bodies and joining and integrating them, the formability and workability are improved by improving the shape accuracy and strength of the molded surface material. In addition, the dimensional accuracy of the divided molded bodies is stabilized, and the occurrence of a step at the joint between the divided molded bodies is prevented. There is also a possibility that a mold is not required in the step of forming the resin core material. Furthermore, by forming the joining surfaces of the divided molded bodies into a shape that engages or fits each other, the joining accuracy of the divided molded bodies is improved, and the workability and the yield are improved. In addition, if the shapes are fitted to each other, it is possible to join and integrate the divided molded bodies without using an adhesive, and it is possible to prevent appearance defects such as sticking out of the adhesive.

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view showing an example of a steering wheel of the present invention.

FIGS. 2A and 2B show examples of a decorative material used in the present invention, wherein FIG. 2A is a plan view and FIG. 2B is a cross-sectional view taken along line BB in FIG.

FIG. 3 is a cross-sectional view illustrating an example of a step of forming a resin reinforced layer according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating an example of a step of forming a resin core material according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an example of a cross-sectional shape of the steering wheel of the present invention.

FIG. 6 shows a second embodiment of the present invention, in which (a)
Is a cross-sectional view of the surface material, and (b) is a cross-sectional view of the divided molded body.

FIG. 7 is a sectional view showing a modification of the surface material according to the second embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating an example of a conventional method for manufacturing a steering wheel.

FIG. 9 is a cross-sectional view for explaining another example of a conventional method for manufacturing a steering wheel.

FIG. 10 is a cross-sectional view for explaining another example of a conventional method for manufacturing a steering wheel.

FIG. 11 is a cross-sectional view for explaining a problem in a conventional method of manufacturing a steering wheel.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Steering wheel, 2 ... Core metal, 3, 13 ... Resin core material, 4, 14 ... Surface material, 5 ... Cosmetic material, 6, 16 ... Resin reinforced layer, 17a ... Concave part, 17b ... Convex part, 18 ... Split molded body

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Suzuki 10-1 Nakazawa-cho, Hamamatsu-shi, Shizuoka Prefecture Inside the Yamaha Corporation (72) Inventor Tadashi Imaizumi 10-1 Nakazawa-cho, Hamamatsu-shi, Shizuoka Prefecture Yamaha Corporation (72) Inventor Toshiharu Fukushima 10-1 Nakazawa-cho, Hamamatsu-shi, Shizuoka F-term in Yamaha Corporation (reference) 3D030 DA25 DA34 DA64 DA67 DB82 4F213 AA04 AA11 AA13 AA15 AA21 AA28 AA29 AA34 AA39 AA42 AB18 AD03 AD04 AD04 AD16 A WA05 WA15 WA52 WA54 WA58 WA74 WB01 WB11

Claims (5)

[Claims] 1. A steering wheel, wherein a surface material formed by laminating a decorative material and a resin reinforcing layer, a resin core material, and a metal core are integrally formed. 2. A step of obtaining a surface material by forming a resin reinforcing layer by filling a resin inside the mold after preliminarily forming a cosmetic material and then disposing the resin in the mold. A method for manufacturing a steering wheel, comprising a step of forming a resin core material by filling a resin with a resin. 3. A method in which a surface material obtained by laminating a decorative material and a resin reinforcing layer, and a plurality of divided molded bodies and a metal core integrally formed with a resin core material are joined and integrated. A special feature of the steering wheel. 4. The steering wheel according to claim 3, wherein joining surfaces of the plurality of divided molded bodies are formed in a shape to be engaged or fitted to each other. 5. A process of preliminarily forming a cosmetic material, disposing it in a mold, filling the inside thereof with a resin to form a resin reinforced layer to obtain a surface material, and filling the inside of the surface material with a resin. A step of forming a resin core material to obtain a divided molded body, and a step of joining and integrating a plurality of divided molded bodies together with a core metal.