JP2010125985A - Steering wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heating efficiency of a heater part to a surface design member. <P>SOLUTION: A steering wheel has an annular-shaped rim part 13. A rim part core body 19 consisting of a rim part core material 20 and a filling material 21 is provided in the inside of the rim part 13. Besides, a decoration member 22 decorated with a grain pattern on its surface is attached to a part of the rim part core body 19. The decoration member 22 covers the rim part core body 19, and the heater part 23 is adhered to an inner side face 22a of the decoration member 22. Moreover, both of the rim part core material 20 and the filling material 21 that compose the rim part core body 19 are made by resin material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a steering wheel in which a heater portion that generates heat when energized is provided in a rim portion.

When the temperature of the steering wheel decreases due to use in a cold region, the occupant may not be able to grip the rim of the steering wheel when driving, or may feel uncomfortable when the occupant grips the rim of the steering wheel. is there. Therefore, conventionally, with respect to this problem, for example, in the steering wheel described in Patent Document 1, the core of the rim portion is coated with a polymer foam material, and the concentric body is a heater portion ( It is covered with a veneer member having a heating element. The heater portion is provided on a support piece of a veneer member attached to the core body, and the surface of the heater portion is covered with a surface design member (cover veneer piece) constituting the outermost layer of the veneer member.
JP-A-2005-335706

  However, in the steering wheel described in Patent Document 1, heat generated from the heater part is dissipated around the heater part. Therefore, for example, when the core that exists inside the heater part is made of a material having high thermal conductivity such as metal, the heat generated from the heater part, although the heater part is intended to warm the surface design member, is used. Most of the heat is radiated to the inside of the heater portion, and the ratio of the amount of heat radiated to the surface design member becomes small. As a result, in the steering wheel described in Patent Document 1, it is necessary to set the energization amount to the heater part in advance in anticipation that much of the heat generated from the heater part is transmitted to the inside of the heater part. Since extra power is required, the heater efficiency of the heater portion with respect to the surface design member was lowered.

  This invention is made | formed in view of the said problem, The objective is to provide the steering wheel which can improve the heater efficiency of the heater part with respect to a surface design member.

  In order to achieve the above object, according to the first aspect of the present invention, the heater portion that generates heat when energized is provided outside the core body of the rim portion, and the heater portion and the core body are the rim portion. In the steering wheel covered with the surface design member constituting the surface of the surface design member, the heater portion is covered with the surface design member in a state where heat can be conducted to the surface design member, and the surface design member The gist of the present invention is that the entire portion of the core covered with is made of a resin material.

  In this invention, the heater part generates heat when energized, and the heat is dissipated around the heater part. In this case, since the core inside the heater is made of a resin material having a lower thermal conductivity than the metal core, the heat generated in the heater is radiated to the core. The ratio of heat to be reduced is reduced, and much heat is radiated to the surface design member side. Therefore, since the ratio of the amount of heat radiated from the heater part to the surface design member is increased, it is possible to reduce the energization amount to the heater part without reducing the amount of heat applied to the surface design member. The heater efficiency of the heater part can be improved.

  In order to achieve the above object, according to a second aspect of the present invention, a heater portion that generates heat when energized is provided inside the rim portion, and the surface of the rim portion is constituted by a surface design member. In the steering wheel, the surface design member is formed in a hollow shape, and the heater is attached to the inner surface of the surface design member and faces the space in the surface design member.

  In this invention, since the inside of the heater portion faces the space and the space has a lower thermal conductivity than the metal, the proportion of the heat radiated to the space side of the heat generated in the heater portion is reduced. A lot of heat is radiated to the surface design member side. Therefore, the invention described in claim 2 has the same action and effect as the invention described in claim 1.

The gist of the invention according to claim 3 is that, in the invention according to claim 2, the surface design member is formed of a resin material.
In this invention, a rim part can be reduced in weight compared with the case where a surface design member is formed with a metal material.

  ADVANTAGE OF THE INVENTION According to this invention, the heater efficiency of the heater part with respect to a surface design member can be improved.

(First embodiment)
A first embodiment embodying the present invention will be described below with reference to FIGS.
As shown in FIG. 1, a steering wheel 11 provided in a driver's seat of a vehicle has a circular shape when viewed from the front, and a steering shaft 12 coupled to a steering wheel can be integrally rotated at the center of the steering wheel 11. It is connected. A rim portion (handle portion) 13 constituting the steering wheel 11 is formed in an annular shape centering on the axis L of the steering shaft 12 and is normally gripped when the driver operates the steering wheel 11. Configured as part. Further, the inner peripheral surface of the rim portion 13 is connected to the boss portion 15 via a plurality of (four in this embodiment) spoke portions 14. A pad 16 is attached to the boss portion 15. An electronic control unit (hereinafter referred to as ECU) 17 is disposed inside the pad 16. The rim portion 13 and the spoke portion 14 are provided with a core 18 that forms a skeleton portion of the entire steering wheel 11. A portion of the core body 18 corresponding to the rim portion 13 is configured as a rim portion core body 19.

  The rim core 19 is formed in an annular shape centering on the axis L of the steering shaft 12 in a front view. As shown in FIG. 2 (a), the rim core 19 has a rim formed so that the cross-sectional shape orthogonal to the axis P of the rim core 19 is substantially concave (channel) opening downward. The core member 20 includes a core member 20 and a filler 21 provided so as to cover the rim core member 20. The filler 21 is made of a soft (elastic) material such as polyurethane foam which is a resin material. The rim core member 20 is made of a hard resin material (for example, polypropylene (PP) containing reinforcing fibers). In addition, when the rim | limb part core material 20 is formed from the polypropylene containing a reinforced fiber, as a reinforced fiber, glass fiber and a carbon fiber are used, for example. The rim core material 20 has a predetermined hardness and toughness similar to that of a metal. The rim core body 19 and the filler 21 are both made of a resin material, so that the rim core body 19 has a thermal conductivity of the rim core body 19 as a whole. Is smaller than Further, as shown in FIG. 1, the rim core 19 is partially covered with a pair of decorating members 22 decorated with a wood grain pattern in the circumferential direction X of the steering wheel 11.

  The pair of decorating members 22 is provided in a portion of the entire circumference of the rim core 19 that is easily gripped by the driver. As shown in FIG. 2B, each of the pair of decorating members 22 has a substantially arc-shaped cross section perpendicular to the axis P of the rim core 19. The decorative member 22 is a hard member having rigidity that does not deform even if it is gripped by a person. The pair of decorating members 22 are joined to each other by means such as adhesion, and have a curved cylindrical shape when joined together. In addition, a heater portion 23 is adhered and in close contact with each inner side surface 22a of the pair of decorating members 22. In addition, the part covered with the decorating member 22 among the rim part core bodies 19 is slightly reduced in diameter compared with the part not covered with the decorating member 22.

  The heater part 23 is configured by sewing a single heater wire 25 into a single-drawn shape on a sheet-like base material 24 having a substantially rectangular shape in plan view having an insulating property. The heater 23 is bonded to the inner surface 22a of the decorative member 22 on the side opposite to the side where the heater wire 25 is sewn and exposed, and the side where the heater wire 25 is sewn and exposed is the rim. It is in contact with the outer peripheral portion 19 a of the core 19. The sheet-like base material 24 is comprised from the nonwoven fabric which has heat conductivity.

  The heater wire 25 continuously extends and extends in a wave shape without overlapping with itself. The heater wire 25 is electrically connected to the ECU 17 (see FIG. 1) via an electric wire (not shown), and generates Joule heat when energized by the ECU 17.

Next, the operation of the steering wheel 11 in this embodiment will be described.
When the vehicle is parked under severe cold in winter, the temperature inside the vehicle is lowered, and accordingly, the temperature of the entire steering wheel 11 is also lowered. When the driver sits in the driver's seat and starts driving in this state, an operation for starting the engine is performed by the driver. Then, energization control for the heater unit 23 is started by the ECU 17. By this control, Joule heat is generated from the heater wire 25 of the heater section 23, and the Joule heat is radiated toward the periphery of the heater wire 25. At this time, both the rim portion core material 20 and the filler 21 are resin materials, and the thermal conductivity of the rim portion core body 19 is smaller than when the rim portion core material 20 is made of metal, The ratio of Joule heat from the heater wire 25 toward the rim core 19 is reduced. Then, most of the Joule heat generated in the heater wire 25 is radiated toward the decorating member 22. Therefore, when the decoration member 22 is warmed, the same amount of heat is given to the decoration member 22 even if the current flowing through the heater wire 25 is smaller than when a metal cored bar is present inside the heater portion 23. Can warm up. Therefore, the heater efficiency with respect to the decoration member 22 by the heater part 23 is improving.

According to this embodiment, the following effects can be obtained.
(1) The rim portion 13 of the steering wheel 11 is provided with a rim core 19 inside thereof. The rim core 19 is covered with a pair of decorating members 22. A heater portion 23 is attached to the inner surface 22 a of the decorative member 22, and the heater portion 23 is provided outside the rim portion core body 19. And the rim | limb part core material 20 and the filler 21 which comprise the rim | limb part core body 19 are comprised from the resin material, and the thermal conductivity of the rim | limb part core body 19 is lower than a metal. Therefore, since the ratio of the amount of heat transmitted from the heater part 23 to the decorating member 22 is larger than when a cored bar is present inside the heater part 23, even if the energization amount to the heater part 23 is reduced, Similarly, the decoration member 22 can be warmed. That is, the heater efficiency with respect to the decoration member 22 by the heater part 23 can be improved.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. In this embodiment, the steering wheel 30 includes a skeleton body 31 that forms the entire skeleton, and the skeleton body 31 includes a first divided body 32 and a second divided body 33, and a rim portion of the steering wheel 30. The configuration is mainly different from that of the first embodiment. And the substantially same part as 1st Embodiment attaches | subjects the same number, and the detailed description is abbreviate | omitted.

  As shown in FIG. 3, the skeleton of the entire steering wheel 30 is constituted by a skeleton body 31. The skeleton body 31 includes a hard resin first divided body 32 (see FIG. 4A) disposed on the steering shaft 12 side, and the first divided body 32 in the direction of the axis L of the steering shaft 12. The second divided body 33 (see FIG. 5A) made of hard resin and arranged so as to overlap is formed by welding and joining.

  As shown in FIG. 4A, the first divided body 32 has a predetermined hardness and toughness similar to a metal material, and is made of (siloxane) -modified polycarbonate. The first divided body 32 includes a boss part 34, a first divided rim part 35 having a ring shape in plan view arranged so as to surround the boss part 34, and a plurality of parts that connect the boss part 34 and the first divided rim part 35. The first divided spoke portion 36 is configured. And the boss | hub part 34, the 1st division | segmentation rim part 35, and the 1st division | segmentation spoke part 36 are shape | molded integrally. The boss portion 34 is provided with a seat portion 37.

  The first divided spoke portion 36 has a substantially U-shaped cross section perpendicular to the radial direction of the first divided rim portion 35. A first rib 38 and a second rib 39 are provided in the recess of each first divided spoke portion 36 so as to be orthogonal to each other. Further, the first divided rim portion 35 is formed in a substantially semicircular arc shape in its radial cross section. Then, as shown in FIG. 4B, a belt-like heater portion 23 is bonded to the concave portion of the first divided rim portion 35 in a state along the axial direction of the first divided rim portion 35.

  On the other hand, as shown to Fig.5 (a), while the 2nd division body 33 has predetermined hardness and toughness similar to a metal material, it is comprised with the (siloxane) modified polycarbonate. The second divided body 33 includes a second divided rim portion 41 having an annular shape in plan view, and a plurality of second divided spoke portions 42 extending from the inner diameter side of the second divided rim portion 41 toward the center of the second divided rim portion 41. It is composed of. In FIG. 5A, the second divided body 33 is shown upside down for convenience of explanation. And the 2nd division | segmentation rim part 41 and the 2nd division | segmentation spoke part 42 are shape | molded integrally.

  The second divided spoke portion 42 has a substantially U-shaped cross section perpendicular to the radial direction of the second divided rim portion 41. A third rib 43 and a fourth rib 44 that are formed to be orthogonal to each other are provided inside the second divided spoke portion 42. The second divided rim portion 41 is formed in a substantially semicircular arc shape in its radial cross section. Further, as shown in FIG. 5B, a belt-like heater portion 23 is bonded to the concave portion of the second divided rim portion 41 in a state along the axial direction of the second divided rim portion 41.

  Then, as shown in FIG. 6, the first divided rim portion 35 and the second divided rim portion 41 are welded and joined in a state where the concave portion of the first divided rim portion 35 and the concave portion of the second divided rim portion 41 face each other. Has been. The joined first divided rim portion 35 and second divided rim portion 41 constitute a hollow surface design member 45 whose surface is exposed. The surface design member 45 is formed in a tubular shape whose cross-sectional shape orthogonal to its own axis P is closed. The surface design member 45 also functions as a rim core that has a hardness that does not deform even when the driver grips it. Further, two heater portions 23 are attached to the inner surface 45 a of the surface design member 45.

  The heater portion 23 has the entire side (inner side) on which the heater wire 25 is provided facing the space R in the surface design member 45. In the space R, a metal member (core metal) does not exist. And the heat conductivity inside the heater part 23 is low, and the heat generated from the heater part 23 is difficult to conduct to the inside of the heater part 23 because the heater part 23 faces the space R. . That is, of the heat generated from the heater wire 25, the ratio of the amount of heat radiated toward the inside (space R side) from the heater portion 23 is reduced, and most of the heat generated in the heater wire 25 is the surface design member 45. Heat is released toward the side. Therefore, when heating the surface design member 45, the heater is provided without reducing the amount of heat applied to the surface design member 45 compared to the case where a metal member (core metal) is provided inside the heater portion 23. The current flowing through the line 25 can be reduced.

According to this embodiment, the following effects can be obtained.
(2) The surface design member 45 is formed in a hollow shape. A plurality of heater portions 23 are provided on the inner surface 45 a of the surface design member 45. The heater part 23 has the entire side (inner side) on which the heater wire 25 is provided facing the space R in the surface design member 45. Accordingly, the ratio of the amount of heat dissipated from the heater portion 23 to the surface design member 45 side can be increased, and the energization amount to the heater portion 23 can be reduced correspondingly. The heater efficiency can be improved.

  (3) The surface design member 45 is formed of a resin material. Therefore, the rim portion of the steering wheel 30 can be reduced in weight compared to the case where the surface design member 45 is formed of a metal material.

  (4) The surface design member 45 also serves as a rim core. Therefore, the configuration of the rim portion can be simplified as compared with the case where the rim portion core body is provided separately from the surface design member 45.

Note that the present invention can be embodied in another embodiment described below.
In the first embodiment, the configuration of the rim core 19 may be changed. For example, the filler 21 may be omitted, and the rim core 19 may be configured with only the rim core 20.

  -In 1st Embodiment, you may comprise the surface design member of the rim | limb part 13 with leather. And the heater part 23 may be provided so that the rim | limb core 19 may be enclosed inside leather.

In the first embodiment, the shape of the rim core member 20 may be changed. For example, the rim core material 20 may be hollow.
In the second embodiment, resin ribs may be provided on each of the first divided rim portion 35 and the second divided rim portion 41. For example, a plurality of ribs parallel to the radial direction of the first divided rim portion 35 may be provided in the concave portion of the first divided rim portion 35 with a predetermined interval therebetween. Similarly, a plurality of ribs parallel to the radial direction of the second divided rim portion 41 may be provided in the recessed portion of the second divided rim portion 41 with a predetermined interval therebetween.

  -In 2nd Embodiment, you may change the material of the hard resin which comprises the 1st division body 32. FIG. For example, the first divided body 32 may be composed of an ABS-based resin, and more specifically, may be composed of a polycarbonate ABS resin.

  -In 2nd Embodiment, you may change the material of the hard resin which comprises the 2nd division body 33. FIG. For example, the second divided body 33 may be made of an ABS-based resin, and more specifically, may be made of a polycarbonate ABS resin.

  In the second embodiment, the surface of the rim core 19 may be covered with a soft resin layer. That is, for example, a soft resin layer made of urethane foam may be provided so as to cover the entire outer surface of the surface design member 45, and the surface design of the rim portion may be configured by the surface design member 45 and the soft resin layer.

  -You may apply this invention to the steering wheel used for the steering apparatus of moving bodies other than a vehicle.

The schematic front view of the steering wheel in 1st Embodiment. (A) is a schematic fragmentary sectional view of the rim part along the AA line of FIG. 1, (b) is a schematic fragmentary sectional view of the rim part along the BB line of FIG. The schematic front view of the steering wheel in 2nd Embodiment. (A) is a schematic perspective view of a 1st division body, (b) is a schematic partial perspective view which shows a 1st division | segmentation rim | limb part and a heater part. (A) is a schematic perspective view of a 2nd division body, (b) is a schematic partial perspective view which shows a 2nd division | segmentation rim | limb part and a heater part. FIG. 4 is a schematic partial cross-sectional view of a rim portion taken along line CC in FIG.

Explanation of symbols

  R: Space, 11, 30: Steering wheel, 13: Rim part, 19: Rim core part as core, 22 ... Decoration member as surface design member, 23: Heater part, 45 ... Surface design member, 45a ... inside.

Claims (3)

In the steering wheel in which the heater part that generates heat by being energized is provided outside the core body of the rim part, and the heater part and the core body are covered by a surface design member constituting the surface of the rim part,
The heater portion is covered with the surface design member in a state where heat conduction is possible with respect to the surface design member,
A steering wheel characterized in that the entire portion of the core covered with the surface design member is made of a resin material. In a steering wheel in which a heater portion that generates heat by being energized is provided inside the rim portion, and the surface of the rim portion is constituted by a surface design member,
The surface design member is formed in a hollow shape,
The heater part is attached to the inner surface of the surface design member, and faces the space in the surface design member. The steering wheel according to claim 2,
The steering wheel according to claim 1, wherein the surface design member is formed of a resin material.

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