JP3367425B2 - Steering wheel and its manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wood veneer on the surface.
A steering wheel having a decorative material having:
First, a surface material is molded, and then a resin is filled into the surface material, and the surface metal is joined and integrated with a cored bar, and the molded product, and a manufacturing method thereof.

[0002]

2. Description of the Related Art The applicant of the present invention has previously disclosed, as a method of manufacturing a steering wheel having a grain pattern, Japanese Patent Laid-Open No. 3104/1996.
The method described in Japanese Patent Application Publication No. 07 is proposed. In this method, for example, as shown in FIG. 8, a wooden surface material 21 made of a wooden decorative material is bent and preformed, and this is placed in a mold 20 together with a core metal 22 to form a wooden surface material 21. This is a method of integrally molding a steering wheel by filling a resin between the core metal 22 and a core material 23 made of resin. Alternatively, for example, as shown in FIG. 9, the wood surface material 21 is bent and preformed, and the wood surface material 21 is placed in a mold 20 and a resin is filled inside to form a resin core material 23. By this, the split molded body 2 of the steering wheel
4 and then as shown in FIG.
It also describes a method of manufacturing a steering wheel by bonding and interposing a cored bar 22 with each other.

[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 wood surface material 21 are small, this wood material is There is a problem that it is difficult to set the surface material 21 in the mold 20, and the formability is extremely poor. In addition, in the method of adhering the divided molded bodies 24 to each other as shown in FIGS. 9 and 10, in addition to the same problem of moldability as described 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 the seam between them.

The present invention has been made in view of the above circumstances, and is to improve moldability when manufacturing a steering wheel having a decorative material having a wood veneer on its surface,
And it is intended to prevent a step due to a seam from being generated on the surface.

[0005]

In order to solve the above problems SUMMARY OF THE INVENTION The steering wheel of the present invention, and a decorative material and the bending strength 100~300MPa having wood veneer
A surface material formed by laminating a resin reinforced layer having a linear expansion coefficient of 8 × 10 ⁻⁵ / ° C. or less , a resin core material, and a core metal integrally molded. Is. Also before
The steering wheel is manufactured by preforming a decorative material having a wood veneer, arranging it in a mold, and filling the inside with a resin so that the bending strength is 100 to 300 MPa .
A step of forming a resin reinforced layer having a linear expansion coefficient of 8 × 10 ⁻⁵ / ° C. or less to obtain a surface material, and a resin is filled between the surface material and the core metal to obtain a linear expansion coefficient of 6 × 10 It is characterized by having a step of forming a resin core material having a temperature of ^-5 / ° C or less .

Further, the steering wheel of the present invention has a bending strength of 100 to 300MP with a decorative material having a wood veneer.
a and a coefficient of linear expansion of 8 × 10 ⁻⁵ / ° C. or less
A surface material formed by laminating a fat reinforcing layer and a linear expansion coefficient of 6 × 1
It is characterized in that a plurality of divided molded bodies integrally molded with a resin core material having a temperature of 0 ⁻⁵ / ° C. or less are joined to a core metal . It is preferable that the joint surfaces of the plurality of divided molded bodies are formed in a shape that engages or fits with each other. In addition , in the manufacturing method of the steering wheel, a decorative material having a wood veneer is preformed and then placed in a mold, and a resin is filled inside the mold so that the bending strength is 100 to 100.
300 MPa and a linear expansion coefficient of 8 × 10 ⁻⁵ / ° C. or less
A step of forming a lower resin reinforced layer to obtain a surface material, and filling the inside of the surface material with a resin to obtain a linear expansion coefficient of 6 × 10 ^−5.
It is characterized by including a step of forming a resin core material having a temperature of / ° C or less to obtain a split molded body, and a step of joining a plurality of split molded bodies to a core metal.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In order to make the present invention easier to understand, examples will be described below. Such an embodiment
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 a steering wheel of the present invention. In FIG. 1, reference numeral 1 is a steering wheel, which includes a rim portion 1a and a spoke portion 1b. The steering wheel 1 is roughly composed of a core metal 2 made of a rod-shaped or pipe-shaped metal, a resin core material 3, and a surface material 4, and the surface material 4 becomes a surface layer.
Decorative material with wood veneer (hereinafter simply referred to as decorative material) 5
And a resin reinforced layer 6 inside thereof are laminated. Further, of the front side and the back side of the steering wheel 1 with the surface passing the core metal 2 as a boundary, the rim portion 1a on the back side is preferably provided with grip irregularities.

Such a steering wheel 1 is manufactured as follows. Hereinafter, a first embodiment of the steering wheel manufacturing method of the present invention will be described. First, the decorative material 5 is curved and preformed. As a result, cosmetic material 5
Is molded to a state close to the surface shape of the steering wheel 1, but it does not necessarily have to match the final shape. The decorative material 5 on the front side of the steering wheel 1
And the decorative material 5 to be the back side are preformed respectively. At this time, the same metal mold may be used for the front side and the back side, or the preforming of the decorative material 5 for the back side has unevenness of the grip. You may perform using a metal mold.

As the material of the decorative material 5, (1) a three-layer decorative material in which wood veneers are laminated on both sides of a thin metal plate, (2) a backing decorative material in which the wood veneer is lined with a backing material, (3) A laminated veneer composed of one or more layers of wood veneer, and (4) a veneer / resin composite material in which a wood veneer and a resin thin plate are laminated can be appropriately selected and used. 2A and 2B show an example in which (1) a three-layer decorative material is used as the decorative material 5, and this is preformed. (A) is a plan view, (b) is BB in (a).
It is sectional drawing which follows the line.

Concretely, (1) as a three-layer decorative material, a wood veneer 5b which is a design of the surface layer and a wood veneer 5c which is an inner layer are integrally bonded to both surfaces of a metal thin plate 5a by adhesion. Is used. The metal thin plate 5a needs to have flexibility and strength to reinforce the wood veneers 5b and 5c laminated on both surfaces, 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. Wood veneer 5b, 5 laminated on both sides of the thin metal plate 5a
Although c may be the same, it is preferable that the surface layer has a beautiful grain pattern. The wood veneers 5b and 5c preferably have a thickness of 0.15 to 1.00 mm. Sheet metal 5
The adhesive used for bonding a to the wood veneers 5b and 5c is not particularly limited, but the three-layer decorative material, that is, the resin-reinforced layer 6 is insert-molded on the inside of the decorative material 5, so that it is preferable. It is preferable to bond under pressure and heat using a heat-resistant thermosetting adhesive. Further, as the material of the metal thin plate 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 thickness of the backing decorative material is 0.15
It is preferable to use a wood veneer having a thickness of up to 1.00 mm backed with a backing material such as Japanese paper or a non-woven fabric of chemical fibers. When such a backing decorative material is used, it is preferable to apply a primer to the back surface thereof, which improves the adhesion of the resin-reinforced layer formed on the back surface of the decorative material 5 to the resin material in the subsequent step. Can be made. As the primer, acrylic resin, epoxy resin, urethane resin or the like can be preferably used. A thermoplastic resin compatible with the resin material of the resin-reinforced layer may be added to the primer. The film thickness of the primer is 20-100
About μm is preferable.

(3) As a laminated veneer, 0.15 to 1.0
A wood veneer of 0 mm may be used alone, or a plywood in which one or a plurality of wood veneers are laminated on the back surface of the wood veneer. The laminated veneer has a thickness of 0.15 to 3.00 mm
The degree is preferable, and if the thickness is smaller than this, the shape retention after molding is deteriorated, and it becomes difficult to stably dispose the surface material 4 in the mold 7 in the subsequent step, and wrinkles may occur. If it is thicker than 3.0 mm, the moldability will deteriorate. It is also possible to simultaneously perform the step of laminating and integrating a plurality of wood veneers to obtain a laminated veneer and the step of preforming this laminated veneer. (4) As a single plate / resin composite material, 0.15-1.00
mm wood veneer backside, thickness 0.10 to 3.00 mm
The one obtained by adhering the resin thin plate of 1 is preferably used. As the material of the resinous thin plate, polyphenylene sulfide (PPS), polycarbonate (PC), ABS resin, etc. are preferable, and those which are compatible with the resin reinforced layer 6 formed on the back surface of the decorative material 5 in a later step. It is selected and used .

The preforming of the decorative material 5 is preferably carried out by a hot press or a vacuum press. The hot press condition is preferably 80 to 140 ° C. and about 1 to 5 minutes,
The vacuum press conditions are preferably 80 to 140 ° C. and 1-1.
It will be about 0 minutes. Alternatively, vacuum forming or compressed air forming may be used. Further, prior to the preforming of the decorative material 5, if necessary, a humidifying treatment by a known method, an alkaline treatment using, for example, ammonia, or the like is appropriately performed.
Can be softened to prevent cracks when processing curved surfaces,
It is effective in improving moldability.

Next, the resin reinforced layer 6 is formed inside the molded decorative material 5 by insert molding in the following manner 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 upper mold 7a that can be opened and closed.
And the lower die 7b, and the inner surface of the cavity 8 of the lower die 7b is formed to have the same shape as the outer surface of the steering wheel 1. In the present embodiment, the inner surface shape of the cavity 8 is different between the molding die 7 for the front side and the molding die 7 for the back side of the steering wheel 1.
On the inner surface of the cavity 8 of the molding die 7 for the back side, unevenness of the grip is formed. Also, the lower mold 7 of the upper mold 7a
A protrusion 9 having a semicircular cross section, which is obtained by dividing the outer shape of the resinous core material 3 into two, is formed on the joint surface with b. The protrusion 9 is formed so as to be positioned at the center of the opening of the cavity 8 when the upper die 7a and the lower die 7b are closed. Then, the molded decorative material 5 is placed in the cavity 8 of the molding die 7, the upper mold 7a is closed, and the decorative material 5 and the upper mold 7 are closed.
A resin is filled between the protrusion 9 and the protrusion 9 and the resin-reinforced layer 6 is insert-molded. At this time, the decorative material 5 is molded into a shape along the inner surface shape of the cavity 8 by the injection molding pressure.

As the material of the resin-reinforced layer 6, (1) polyphenylene sulfide (PPS), (2) polycarbonate (PC), (3) ABS resin and the like are preferably used.
Further, glass fiber, carbon fiber, aramid fiber, whisker, etc. may be filled in these resins in an amount of 0 to 70% by weight as a filler. Regarding the basic physical property values of the resin-reinforced layer 6, if the bending strength and Young's modulus are too small, the overall rigidity will decrease, and if it is too large, the workability at the time of molding may be adversely affected, so the bending strength is 100 to 300 MP.
a, more preferably about 150 to 250 MPa,
The Young's modulus is preferably 10 to 25 GPa, more preferably about 15 to 20 GPa. If the coefficient of linear expansion is large, it deforms at high temperature, so it may be 0, but 0 to 8
× 10 ^-5 / ° C, more preferably 0 to 5 × 10 ^-5 / ° C.
It is considered as a degree. (1) A preferable molding condition when using polyphenylene sulfide (PPS) is a cylinder temperature of 280 to 320.
C, mold temperature 80-160C, injection pressure 30-100M
Pa. (2) Preferred molding conditions when using polycarbonate (PC) 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) Preferred molding conditions when using the ABS resin are a cylinder temperature of 150 to 250 ° C. and a mold temperature of 50 to 100.
The injection pressure is 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 thus obtained with resin to form a steering wheel molded body. To get When the resin for the resin core material 3 is filled, the surface material 4 may be placed in the mold, or the surface material 4 has rigidity and is not deformed at the time of filling without the mold. If it does not occur, the mold may not be used. At the same time that the resin core material 3 is formed, the resin core material 3 and the core metal 2 are integrated. That is, first, a molding die 10 as shown in FIG. 4 is prepared in advance. Mold 10 for molding
Comprises an upper mold 10a and a lower mold 10b which can be opened and closed. The shape of the inner surface of the cavity 11 does not necessarily match the shape of the outer surface of the steering wheel 1, but the surface material 4 for the front side and the surface material 4 for the back side arranged in the cavity 11 can be clamped. It is necessary. on the other hand,
Prepare the core metal 2. The core metal 2 is formed by using a metal rod or a metal pipe, and it is preferable that the rim portion 1a and the spoke portion 1b are integrally formed.

Then, as shown in FIG. 4, the molding die 1 is used.
The front surface material 4 and the back surface material 4 that have been molded are arranged in the cavity 11 of 0, and the cored bar 2 is arranged so as to be located in the center of these. Then, a resin is filled between the surface materials 4, 4 and the core metal 2 to mold the resin core material 3 and integrate the core metal 2. The material of the resin core material 3 is preferably a foaming resin such as urethane foam resin or foaming epoxy resin, and carbon resin or glass fiber may be filled as a filler in about 0 to 70% by weight in these resins. . Preferred molding conditions for molding the resin core material 3 using these foaming resins are 20 to 150 ° C. and 3 to 60.
It's about a minute. Then, the steering wheel molded body thus obtained is taken out of the mold 10, and after finishing the joint between the two surface materials 4 and 4 with paper or the like, coloring, painting, polishing or the like is performed as necessary. As a result, the steering wheel 1 as the final product is obtained.

Regarding the basic physical properties of the resin core material 3, if the density is too small, the strength will be insufficient, and if it is too large, defective molding will occur, so 0.1 to 0.5 g / cm ³ is preferable.
More preferably, it is about 0.1 to 0.3 g / cm ³ . The bending strength is preferably 0.5 to 1.5 MPa, more preferably about 0.7 to 1.2 MPa, because if the bending strength is too small, the core metal 2 cannot be held, and if it is too large, the expansion force generated during heating increases. It is said that If the linear expansion coefficient is large, the resin-reinforced layer may be deformed, and thus may be 0, but 0 to 6 × 10 ⁻⁵ / ° C., and more preferably 0 to
It is set to about 4 × 10 ⁻⁵ / ° C.

As the material of the resin core material 3, thermosetting resins 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)
K), polyvinyl chloride (PVC), and thermoplastics such as nylon can be used. Further, glass fiber, carbon fiber, aramid fiber, whisker, etc. may be filled in these resins in an amount of 0 to 70% by weight as a filler.

In this embodiment, the decorative material 5 and the bending strength are
As shown in FIG. 5 (a), the surface material 4 made of the resin reinforced layer 6 having a degree of 100 to 300 MPa is divided into two parts by the surface passing through the core metal 2, and the surface material 4, The seams 12, 12 of No. 4 are arranged on the surface P passing through the core metal 2.
The position of is not limited to this. For example, FIGS. 5B and 5C
It may be configured as shown in. In the example of FIG. 5B, the surface material 4 is formed such that the surface material 4 on the front side is larger than the surface material 4 on the back side, and the joints 12 and 12 are located on the back side of the surface P. Is configured to. In this way, it is preferable in terms of appearance that the joints 12 and 12 are located on the back side. In the example of FIG. 5C, the end surfaces of the two surface materials 4 and 4 are formed in a taper shape, and the joint surfaces 12 and 12 are formed by abutting the end surfaces. By doing so, the strength at the joint between the front and back surface materials 4, 4 is increased.

In the steering wheel 1 manufactured in this manner, the surface material 4 is a decorative material 5 whose surface layer is a design,
Since it is composed of two layers of the resin reinforced layer 6 having a bending strength of 100 to 300 MPa inside thereof, 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 used without using a mold.
Can be formed. In addition, the conventional bending strength
Since the resin reinforced layer 6 having a pressure of 100 to 300 MPa was not provided, the shape accuracy and strength of the surface material 4 were low, and the deviation of the surface material 4 or the resin core material 3 was eliminated in the step of forming the resin core material 3. Defects such as squeeze out of the constituent resin are likely to occur, and the non-defective rate was about 50%.
According to the present embodiment, since the shape accuracy and strength of the surface material 4 are improved, the occurrence of defects as described above is suppressed,
The non-defective rate can be improved to about 80%. Further, according to the manufacturing method of this embodiment, at the same time when the resin core material 3 is molded,
Since the surface material 4, the resin core material 3 and the core metal 2 can be integrated, the number of steps is small and the manufacturing efficiency is good. Further, it is easy to manufacture because it does not require complicated work and is suitable for mass production. The combination of the material of the decorative material 5, the preforming method, the material of the resin reinforced layer 6, and the material of the resin core material 3 described above is not particularly limited and is arbitrary.

Next, a second embodiment of the steering wheel manufacturing method of the present invention will be described. This embodiment is greatly different from the first embodiment in that, when the resin core material 13 is formed, the split molded bodies 18 each having a shape in which the steering wheel 1 is split into two are formed on the front side and the back side, respectively. The point is to join and integrate these divided molded bodies 18. First, the decorative material 5 is preformed in the same manner as in the first embodiment.
The same material as that of the first embodiment can be used as the material of the decorative material 5.

Next, as shown in FIG. 6 (a), a bending strength of 10 is obtained by insert molding inside the molded decorative material 5.
The surface reinforcement 14 is manufactured by forming the resin reinforced layer 16 having a pressure of 0 to 300 MPa . At this time, as the molding die, a molding die for the front side and a molding die for the back side, which are formed so 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, respectively, The unevenness of the grip is formed on the inner surface of the cavity for the back side. Further, the resin reinforced layer 16 of the surface material 14 on the front side of the steering wheel 1 after molding and the surface material 1 on the back side of the steering wheel 1.
It is preferable to form a concave portion 17a and a convex portion 17b, which engage with each other, on the joint surface with the resin reinforced layer 16 of No. 4 respectively. Resin Material Forming Resin Reinforcement Layer 16, Resin Reinforcement Layer 1
The basic physical property values and molding conditions of No. 6 are the same as those of the resin reinforced layer 6 in the first embodiment.

Next, as shown in FIG. 6B, the obtained front surface material 14 and back surface material 14 are placed in a mold, and a resin is filled inside the mold to form a resin core material. 1
3 is formed, and the divided molded body 18 for the front side and the divided molded body 18 for the back side are respectively manufactured. At this time, the divided molded body 1
Groove 18a for accommodating the cored bar 2 in the joint surface between the eight
Is formed. The material, molding conditions, and basic physical property values of the resin core material 13 are the same as those of the resin core material 3 in the first embodiment.

The split molded body 18 for the front side and the split molded body 18 for the back side thus obtained are arranged with the core metal 2 in these grooves 18a, and the recesses formed in the joint surface. 17a and the convex portion 17b are engaged with each other to join and integrate the two divided molded bodies 18 and the core metal 2.
It is preferable to integrate these by using an adhesive.
Further, as the core metal 2, the one in which the rim portion 1a and the spoke portion 1b are integrally formed in advance is used as in the case of the first embodiment, or the rim portion is used when the split molded body 18 is bonded. You may adhere 1a and the spoke part 1b. After that, after the joint between the two divided molded bodies 18 is finished with paper or the like, coloring, painting, polishing or the like is performed as necessary, whereby the steering wheel 1 as a final product is obtained.

According to this embodiment, the surface material 14 is a surface material of the decorative material 5 and the bending strength inside thereof is 100 to 3.
Since it is composed of two layers of the resin reinforced layer 16 of 00 MPa, the shape accuracy and strength of the molded surface material 14 are improved. Therefore, the conventional problem that it is difficult to set the surface material 14 in the mold in the step of forming the resin core material 13 is solved, the moldability is improved, and the workability is improved. If the rigidity of the surface material 14 is further increased, the resin core material 13 can be formed without using a mold. Further, since the shape accuracy and strength of the molded surface material 14 are improved, the dimensional accuracy of the split molded body 18 is increased, and a step is prevented from occurring at the joint between the split molded bodies 18. Further, in the present embodiment, since the concave portions 17a and the convex portions 17b which are engaged with each other are formed on the joint surfaces of the split molded bodies 18, the split molded bodies 18 are joined with high precision.

In this embodiment, the resin reinforced layer 16 is used.
Although the concave portions 17a and the convex portions 17b are provided on the joint surfaces between them, the concave portions 17a and the convex portions 17b may be formed on the joint surfaces between the resin core materials 13, or the resin reinforced layer 16 and the resin core are provided. It may be provided on both materials 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 are engaged with each other. Further, for example, a shape that can be fitted as shown in FIG. 7 may be adopted, and by doing so, it becomes possible to integrate the divided molded bodies 18 without using an adhesive, and a defective appearance due to the protrusion of the adhesive or the like. Occurrence can be prevented. Also in this embodiment, the material of the decorative material 5, the preforming method, the material of the resin reinforced layer 16, and the resin core material 13 are also used.
The combination of materials is not particularly limited and is arbitrary.

[0028]

EXAMPLES The effects of the present invention will be clarified below with reference to specific examples. (Example 1) As the decorative material 5, a wood veneer having a thickness of 0.2 mm, which is a design of the surface layer, and a wood veneer having a thickness of 0.2 mm, which is an inner layer, are provided on both surfaces of an aluminum thin plate having a thickness of 0.1 mm. A three-layer decorative material obtained by adhering the above was prepared. First, cosmetic material 5
Was subjected to curved surface processing by hot pressing and preformed. The hot press condition at this time was 140 ° C. for 3 minutes. Next, the molded decorative material 5 is applied to the lower mold 7b of the mold 7 shown in FIG.
The resin-reinforced layer 6 is placed inside and the upper mold 7a is closed, and a resin is filled between the decorative material 5 and the upper mold 7a to perform insert molding.
To form a surface material 4. As the resin to be filled, P
A product obtained by adding 30% by weight of carbon fiber to PS (Fortron 2130A1 manufactured by Polyplastics 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 front surface material 4 and the back surface material 4 used molding dies 7 having different inner surface shapes, and the back surface material 4 was provided with uneven grips. 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 linear expansion coefficient was 0 in the flow direction, and 4.3 × 10 ⁻⁵ / ° C. in the direction perpendicular to this.

Next, the surface material 4 for the front side and the surface material 4 for the back side thus obtained are placed in a cavity 11 of a mold 10 shown in FIG.
The core metal 2 was disposed near the center of the cavity 11 as well as inside. Then, a foamable urethane resin was filled between the resin reinforcing layer 6 of the surface material 4 and the core metal 2, and this was foamed and cured to form the resin core material 3. The molding condition is 50 ° C. for 5 minutes, and the density of the resin core material 3 formed is 0.3 g /
cm ³ , bending strength 1.0 MPa, linear expansion coefficient 4 × 10 ^-5
/ ° C. In this way, the surface material 4 and the resin core material 3
A molded body in which the core metal 2 and the core metal 2 are integrated is obtained, the molded body is taken out of the mold, and the joint between the surface materials 4 and 4 is finished with paper or the like, and then colored, painted, and polished as necessary. Then, 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 reinforced layer 6.
That is, in the same manner as in Example 1 above, the decorative material 5 was preformed, placed in the mold 7 shown in FIG. 3, filled with resin, and insert-molded to form the resin reinforced layer 6, Surface material 4 was obtained. As the resin to be filled, PC containing 30% by weight of carbon fiber was used. Molding conditions are cylinder temperature 330 ℃, mold temperature 120 ℃, injection pressure 70
It was set to MPa. The front surface material 4 and the back surface material 4 used molding dies 7 having different inner surface shapes, and the back surface material 4 was provided with uneven grips.
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. Then, 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 core metal 2 were integrated. Further, the obtained molded body is taken out of the mold, and the surface material 4,
After finishing the joint between the four pieces with paper or the like, coloring, painting, polishing, etc. were performed as necessary to obtain a steering wheel 1.

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 reinforced layer 6. That is, in the same manner as in Example 1 above, the decorative material 5 was preformed, placed in the mold 7 shown in FIG. 3, filled with resin, and insert-molded to form the resin reinforced layer 6, Surface material 4 was obtained. As the resin to be filled, an ABS resin containing 30% by weight of carbon fiber was used.
Molding conditions are cylinder temperature 230 ℃, mold temperature 80 ℃,
The injection pressure was 70 MPa. The front surface material 4 and the back surface material 4 used molding dies 7 having different inner surface shapes, and the back surface material 4 was provided with uneven grips. 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 in the direction perpendicular to this. It was ^-5 / ° C. Then, in the same manner as in Example 1 above, a resin core material 3 was formed using a foamable urethane resin.
Was formed to integrate the surface material 4, the resin core material 3, and the core metal 2. Furthermore, after removing the obtained molded body from the mold and finishing the joint between the surface materials 4 and 4 with paper or the like,
Steering wheel 1 was obtained by coloring, painting, polishing, etc., as needed.

Example 4 A steering wheel 1 was manufactured in the same manner as in Example 1 except that a lining 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 non-woven fabric (weight per unit area: 50 g / cm) is applied to a wood veneer having a thickness of 0.2 mm, which is the design of the surface.
^The one lined in ² ) was used. And this decorative material 5
Was subjected to curved surface processing by hot pressing and preformed. The hot press condition at this time was 140 ° C. for 3 minutes. Then, preferably, in order to improve the adhesion between the decorative material 5 and the resin-reinforced layer 6, on the non-woven fabric surface of the molded decorative material 5,
A primer having an acrylic resin having a tertiary amine as a functional group as a main agent and an epoxy resin having a glycidyl group as a functional group as a curing agent was applied and dried. The film thickness of the primer is 3
It was set to 0 μm. Thereafter, in the same manner as in Example 1 above, a resin reinforced layer 6 was formed on the inside of the decorative material 5 using a resin material obtained by adding carbon fibers to PPS to obtain a surface material 4, and then foamability was obtained. Resin core material 3 made from urethane resin
Was formed to integrate the surface material 4, the resin core material 3, and the core metal 2. Furthermore, after removing the obtained molded body from the mold and finishing the joint between the surface materials 4 and 4 with paper or the like,
Steering wheel 1 was obtained by coloring, painting, polishing, etc., as needed.

[0033]

As described above, according to the present invention,
The surface material is a decorative material with a wood veneer and a bending strength of 100
Since it is composed of two layers of the resin reinforced layer of up to 300 MPa, the shape accuracy and strength of the molded surface material are improved. Therefore, it becomes easy to set the surface material preformed in the mold in the step of forming the resin core material, the moldability is improved, and the workability is improved. In addition, there is a possibility that the mold is unnecessary in the step of forming the resin core material. Further, by improving the shape accuracy and strength of the molded surface material, it is possible to suppress the occurrence of defects such as the displacement of the surface materials in the step of forming the resin core material and the protrusion of the resin forming the resin core material, The rate of non-defective products is improved.

Further, in the method of molding a plurality of divided molded bodies and joining and integrating them, the shape accuracy and strength of the molded surface material are improved, so that the moldability is improved and the workability is improved. At the same time, the dimensional accuracy of the divided molded bodies is stabilized, and a step is prevented from occurring at the joint between the divided molded bodies. In addition, there is a possibility that the mold is unnecessary in the step of forming the resin core material. Further, by forming the joint surfaces of the divided molded bodies into a shape that engages or fits with each other, the joining accuracy of the divided molded bodies is improved, and the workability and the yield are improved. Further, if the shapes are such that they fit with each other, the divided molded bodies can be joined and integrated without using an adhesive, and appearance defects such as protrusion of the adhesive can be prevented.

[Brief description of drawings]

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

2A and 2B show an example of a decorative material used in the present invention, FIG. 2A is a plan view, and FIG. 2B is a sectional view taken along line BB in FIG. 2A.

FIG. 3 is a cross-sectional view showing an example of a process of forming a resin-reinforced layer in the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing 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, (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 cross-sectional view showing a modified example of the surface material in the second embodiment of the present invention.

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

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

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

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

[Explanation of symbols]

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

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Imaizumi 10-1 Nakazawa-machi, Hamamatsu-shi, Shizuoka Prefecture Yamaha stock company (72) Toshiharu Fukushima 10-1 Nakazawa-machi, Hamamatsu-shi, Shizuoka Yamaha stock company (56) References JP-A 8-310407 (JP, A) JP-A 61-146501 (JP, A) JP-A 5-269705 (JP, A) JP-A 6-238823 (JP, A) Jikkou 47-16333 (JP, Y1) The Japan Society of Polymer Science, Editorial Committee for Polymer Dictionary, New Edition Polymer Dictionary, Japan, Asakura Shoten Co., Ltd., August 10, 1991, page 338 (58) Fields investigated (Int.Cl. ⁷ , DB name) B62D 1/04-1/28 B29D 31/00

Claims (5)

(57) [Claims] 1. A decorative material having a wood veneer and a bending strength of 1
0 to 300 MPa and a linear expansion coefficient of 8 × 10 ⁻⁵
A surface material formed by laminating a resin reinforced layer having a temperature of / ° C or less ,
A resin core material having a linear expansion coefficient of 6 × 10 ⁻⁵ / ° C. or less ;
A steering wheel characterized by being integrally molded with a core metal. 2. A decorative material having a wood veneer is preformed, then placed in a mold, and the inside is filled with a resin to have a bending strength of 100 to 300 MPa and a linear expansion coefficient of 8 × 10.
^A step of forming a resin reinforced layer having a temperature of ^-5 / ° C or less to obtain a surface material, and linear expansion by filling a resin between the surface material and a core metal.
The method for manufacturing a steering wheel according to claim 1, further comprising the step of forming a resin core material having a rate of 6 × 10 ⁻⁵ / ° C. or less . 3. A decorative material having a wood veneer and a bending strength of 1
0 to 300 MPa and a linear expansion coefficient of 8 × 10 ⁻⁵
A surface material formed by laminating a resin reinforced layer having a temperature of / ° C or less,
A steering wheel comprising a cored bar and a plurality of split molded bodies integrally molded with a resin core material having a linear expansion coefficient of 6 × 10 ⁻⁵ / ° C. or less . 4. The steering wheel according to claim 3, wherein the joint surfaces of the plurality of divided molded bodies are formed in a shape that engages or fits with each other. 5. A decorative material having a wood veneer is preformed, then placed in a mold, and the inside is filled with a resin to have a bending strength of 100 to 300 MPa and a linear expansion coefficient of 8 × 10.
^A step of forming a resin reinforced layer having a temperature of ⁻⁵ / ° C. or less to obtain a surface material, and filling the inside of the surface material with a resin to obtain a linear expansion coefficient of 6;
5. The method according to claim 3 or 4, further comprising a step of forming a resin core material having a temperature of × 10 ^-5 / ° C or less to obtain a divided molded body, and a step of bonding a plurality of divided molded bodies to a core metal. scan <br/> process of tearing wheel.