Steering wheel

Abstract

To provide a steering wheel which is provided in a steering part with a heating element heated on electrification, and which can improve the temperature rising characteristic of the surface of the steering part to a power to be inputted into the heating element.SOLUTION: A steering wheel 10 has a steering part 1 which is steered on gripping by a driver, and which is formed by a stack of a plurality of layers on a core material, and is provided with a heater wire as a heating element heated on electrification inside the plurality of layers, in which the plurality of layers of the steering part 1 include a protection layer 1d4 as an ore-containing layer placed closer to a front layer than the heater wire and containing an ore 30 radiating far-infrared rays.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a steering wheel having a heating element provided in a steering section that is gripped and steered by a driver. [Background technology]

[0002] As a countermeasure against the cold in winter, a steering wheel has been widely known, as described in Patent Document 1, in which a heating element that generates heat when electricity is passed through the steering part that is gripped and steered by the driver is provided, and the heat generated by the heating element raises the temperature of the surface of the steering part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-96740 Summary of the Invention [Problem to be solved by the invention]

[0004] In a steering wheel in which a heating element that generates heat when electricity is applied is provided in the steering section, it is desirable, from the standpoint of reducing power consumption, that the steering section have a high temperature rise characteristic on the surface of the heating element in response to the power input to the heating element.

[0005] Therefore, the present invention aims to provide a steering wheel in which a heating element that generates heat when electricity is applied is provided in the steering section, and which can improve the temperature rise characteristics of the surface of the steering section in response to the power input to the heating element. [Means for solving the problem]

[0006] A typical configuration of a steering wheel according to the present invention for solving the above-mentioned problems is a steering wheel comprising: a steering section which is gripped and steered by a driver, the steering section being formed by laminating a plurality of layers on a core material, the plurality of layers being provided with a heating element which generates heat when electricity is passed through the interior of the plurality of layers; and a boss section which is arranged inside the steering section and connected to the steering center shaft of the steering section, wherein the plurality of layers of the steering section include an ore-containing layer which is arranged on the outer surface side of the heating element and contains an ore which radiates far infrared rays.

[0007] According to the present invention, a heating element that generates heat when electricity is applied is provided inside a plurality of layers that are laminated on a core material to form the steering portion of a steering wheel, and an ore-containing layer containing ores that radiate far-infrared rays is provided on the surface side of the heating element. As a result, the ore-containing layer is heated by the heat generated by the heating element and radiates a large amount of far-infrared rays, so that the heating element and the ore-containing layer can raise the temperature of the surface of the steering portion, thereby improving the temperature rise characteristic of the surface of the steering portion relative to the power input to the heating element.

[0008] The ore may be mixed into the paint applied to the surface of the steering section. With this configuration, a large amount of far infrared rays is emitted from the part that the driver touches, making it easier for the driver's hands to be warmed, and providing the driver with better protection against the cold.

[0009] It is also preferable that the ore-containing layer contains a plurality of types of ore, which can suppress a decrease in the temperature rise characteristics of the surface of the steering section due to a decrease in the emissivity of a specific wavelength band caused by each type of ore. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a plan view of a steering wheel according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of a steering portion of a steering wheel taken along the line A1-A1 shown in FIG. 1. [Figure 3] 1A and 1B are a plan view and a cross-sectional view of the heater layer of the steering section in an expanded state. [Figure 4] FIG. 2 is a diagram showing the layer configuration of a skin layer, which is one of the multiple layers of the steering section. DETAILED DESCRIPTION OF THE INVENTION

[0011] A steering wheel 10 according to one embodiment of the present invention will be described below. The steering wheel 10 is mounted on a vehicle (not shown). In the following description, unless otherwise specified, the up-down direction refers to the up-down direction along the axial direction of a steering shaft (not shown), the front-rear direction refers to the front-rear direction perpendicular to the axial direction of the steering shaft when the vehicle is steered straight ahead, and the left-right direction refers to the left-right direction perpendicular to the axial direction of the steering shaft when the vehicle is steered straight ahead.

[0012] FIG. 1 is a plan view of a steering wheel 10 according to one embodiment of the present invention. In FIG. 1, to make the internal configuration easier to see, an upper cover 3x is made transparent and only the outline is shown by a two-dot chain line. As shown in FIG. 1, the steering wheel 10 includes a steering section 1, a boss section 2 that is disposed inside the steering section 1 and connected to a steering shaft (not shown) that serves as a steering axis, and spoke sections 3 that connect the steering section 1 and the boss section 2. In addition, a lower cover (not shown) is provided on the underside of the steering wheel 10.

[0013] The steering unit 1 is an annular member that is gripped and rotationally steered by the driver of the vehicle. The driver grips the steering unit 1 and rotates the steering unit 1 around a steering shaft connected to the boss unit 2, thereby changing the direction of travel of the vehicle. The steering unit 1 is formed by laminating multiple layers, such as a metal core 1a made of an aluminum alloy or the like, on top of which are coated layer 1b (FIG. 2) that coats the core 1a. Details of these multiple layers will be described later.

[0014] The boss portion 2 is a metal member disposed at the center of the steering unit 1 and connected to a steering shaft (not shown). The boss portion 2 has an axial hole 2a through which the steering shaft is inserted, and with the tip of the steering shaft inserted and fitted into the axial hole 2a, the tip of the steering shaft is fastened with a nut, thereby connecting the boss portion 2 and the steering shaft. The boss portion 2 is also molded integrally with a metal core material 2b.

[0015] In this embodiment, the core material 1a of the steering unit 1, the core material 2b of the boss unit 2, and the core materials 3a1, 3b1, and 3c1 of the spoke unit 3, which will be described later, are integrally molded by die-casting, thereby connecting the steering unit 1, the boss unit 2, and the spoke unit 3. However, the core material 1a of the steering unit 1, the core material 2b of the boss unit 2, and the core materials 3a1, 3b1, and 3c1 of the spoke unit 3 may be formed separately and then connected by welding or the like.

[0016] The spoke portion 3 is composed of spoke portions 3a and 3b extending to both the left and right sides from the boss portion 2, and spoke portion 3c extending rearward from the boss portion 2. Spoke portions 3a and 3b have metal core members 3a1 and 3b1 extending to both the left and right sides so as to connect core member 1a of the steering portion 1 and core member 2b of the boss portion 2, respectively. Spoke portion 3c has metal core member 3c1 extending rearward from core member 2b of the boss portion 2 and branching to the left and right before connecting to core member 1a of the steering portion 1. In addition, spoke portions 3a, 3b, and 3c have resin upper covers 3x that cover core members 3a1, 3b1, and 3c1.

[0017] Next, the multiple layers laminated on the core material 1a of the steering section 1 will be described in detail. Fig. 2 is a cross-sectional view of the steering section 1 taken along the A1-A1 cross section shown in Fig. 1. Fig. 3 is a plan view and a cross-sectional view of the heater layer 1c, which is one of the multiple layers of the steering section 1, in an expanded state. Fig. 4 is an enlarged cross-sectional view of region V shown in Fig. 2, showing the layer configuration of the skin layer 1d, which is one of the multiple layers of the steering section 1.

[0018] As shown in Figure 2, the steering section 1 is formed by laminating, in order, a covering layer 1b made of polyurethane foam that covers the core material 1a, a heater layer 1c having a heater wire 22, and a skin layer 1d made of synthetic leather around the outer periphery of a core material 1a. The skin layer 1d is divided into four parts in the circumferential direction of the steering section 1, with one on each of the top, bottom, left, and right (see Figure 1). These four skin layers 1d have slightly different shapes to match the shapes of the areas where they are installed, but they all have the same layer configuration, so the following will explain the configuration of only one skin layer 1d. Similarly, the heater layer 1c is divided into two parts in the circumferential direction of the steering section 1, with one on each of the left and right sides. However, the two heater layers 1c differ only in that they are symmetrical in shape, so the following will explain the configuration of only the right heater layer 1c.

[0019] As shown in FIG. 3, the heater layer 1c is composed of two substrates 20a and 20b sandwiching a heater wire 22 as a heating element, and is laminated on the outer periphery of the covering layer 1b by bonding them together with an adhesive (not shown). The substrates 20a and 20b are flexible sheets made of foamed polyurethane with a thickness of approximately 0.5 to 0.8 mm, and are bonded together with an adhesive (not shown). The density of the substrate 20b on the skin layer 1d side is higher than the density of the substrate 20a on the covering layer 1b side. This improves the heat insulating properties of the substrate 20a to suppress heat conduction to the core material 1a side, and also improves the thermal conductivity of the substrate 20b, making it easier to conduct heat generated by the heater wire 22 to the skin layer 1d side, thereby improving the temperature rise characteristics of the surface of the steering section 1.

[0020] The heater wire 22 is configured by winding a plurality of conductor strands made of tin-copper alloy wires with a strand diameter of approximately 0.08 mm around a heater core made of a bundle of aromatic polyamide fibers with an outer diameter of approximately 0.2 mm in a spiral shape at a pitch of approximately 1.00 mm. The heater wire 22 is arranged between the substrates 20 a, 20 b in a predetermined unicursal pattern and is connected to lead wires 23 electrically connected to a control device (not shown). The control device controls the flow of electricity through the heater wire 22, causing the heater wire 22 to generate heat and raise the temperature of the surface of the steering section 1.

[0021] 4, the surface layer 1d is formed by laminating a base fabric layer 1d1, an intermediate layer 1d2, a colored layer 1d3, and a protective layer 1d4 in this order, and is bonded to the outer periphery of the heater layer 1c with an adhesive (not shown). The base fabric layer 1d1 is made of fibers such as nonwoven fabric, and is provided to ensure the shape retention of the surface layer 1d and improve the workability of bonding the surface layer 1d to the heater layer 1c, and to provide the steering section 1 with a hardness similar to that of natural leather in terms of feel.

[0022] The intermediate layer 1d2 is made of foamed polyurethane to provide elasticity, and is adhered to the outer periphery of the base fabric layer 1d1 via adhesive 35. The intermediate layer 1d2 is provided to provide the steering section 1 with an elasticity similar to that of natural leather to give it a tactile feel. The colored layer 1d3 is made of a urethane-based paint containing a colorant, and is applied to the outer periphery of the intermediate layer 1d2. The color of the colorant contained in the colored layer 1d3 determines the color of the surface of the steering section 1.

[0023] The protective layer 1d4, which serves as an ore-containing layer, is a layer disposed on the outermost surface of the steering section 1, and is made of a urethane-based paint that is applied to the outer periphery of the colored layer 1d3. The protective layer 1d4 prevents the driver's hands from directly touching the colored layer 1d3, protecting the colored layer 1d3 from wear and preventing the colorant from peeling off. The protective layer 1d4 also contains ore 30 that emits far infrared rays. The ore 30 is crushed to about 100 μm, mixed into the paint that constitutes the protective layer 1d4, and scattered throughout the entire protective layer 1d4. In this embodiment, the protective layer 1d4 contains about 5 to 10% by weight of ore 30.

[0024] In this way, in the steering section 1, by including the ore 30 that radiates far-infrared rays in the protective layer 1d4 that is on the surface side of the heater wire 22, the following effect is achieved. That is, according to Planck's law of radiation, the ore 30 is heated by the heat generated by the heater wire 22, and the amount of far-infrared rays radiated from the ore 30 increases. Furthermore, by including the ore 30 in the layer on the surface side of the heater wire 22, the distance between the surface of the steering section 1 and the ore 30 becomes smaller, and therefore the surface of the steering section 1 is more likely to be heated by the far-infrared rays radiated from the ore 30. As a result, the surface of the steering section 1 can be heated by the heat generated by the heater wire 22 and the far-infrared rays radiated from the protective layer 1d4, and therefore the temperature rise characteristics of the surface of the steering section 1 in relation to the power input to the heater wire 22 can be improved.

[0025] In this embodiment, the ore 30 is crushed into small pieces, mixed into the paint that forms the protective layer 1d4, which is the outermost layer of the steering unit 1, and scattered throughout the entire protective layer 1d4. As a result, far infrared rays are emitted from the entire protective layer 1d4, which can suppress uneven temperature rise on the surface of the steering unit 1. Furthermore, since a large amount of far infrared rays is emitted from the parts that the driver touches, the driver's hands are easily warmed, and the driver's cold weather measures can be further strengthened.

[0026] Furthermore, in order to increase the emissivity of far-infrared rays and improve the heating characteristics of the surface of the steering section 1, the type of ore 30 preferably selected is one containing elements Si, Ca, or Mg in its chemical formula, such as tourmaline, silica, or calcium carbide, and in particular, an ore 30 having an emissivity (ε) of 0.6 or more is preferably selected. Furthermore, the thermal conductivity of the ore 30 is preferably selected to be 1 to 2 W / m·K or more. Furthermore, by including multiple types of ore 30 in the protective layer 1d4, it is possible to suppress a decrease in the heating characteristics of the steering section 1 due to a decrease in the emissivity of various ores 30 in a specific wavelength band.

[0027] Although the present embodiment has been described with respect to a configuration in which the protective layer 1d4 of the skin layer 1d in the steering section 1 contains the ore 30, the present invention is not limited to this. That is, the same effect as above can be obtained by arranging the ore-containing layer containing the ore 30 on the surface side of the heater wire 22 in the steering section 1. For example, the ore 30 may be contained in the colored layer 1d3 by mixing crushed ore 30 together with a colorant into the paint that constitutes the colored layer 1d3 of the skin layer 1d. In this way, the ore 30 is coated with the protective layer 1d4, and peeling of the ore 30 from the steering section 1 can be suppressed.

[0028] Alternatively, crushed ore 30 may be kneaded into the fabric layer 1d1 of the skin layer 1d to make the fabric layer 1d1 an ore-containing fiber, thereby incorporating the ore 30 into the fabric layer 1d1. In this case, it is preferable to crush the ore 30 to about 0.5 μm and incorporate about 1% by weight of the fabric layer 1d1. This prevents the driver from directly touching the ore 30 with their hands, thereby preventing the ore 30 from peeling off from the steering section 1. Alternatively, the ore 30 may be incorporated into multiple layers constituting the skin layer 1d.

[0029] Furthermore, although the present embodiment has been described with reference to a configuration in which the skin layer 1d is synthetic leather, the present invention is not limited to this, and natural leather may also be used. When using a natural leather skin layer 1d, the mineral 30 may be mixed into a coloring agent used to color the natural leather, or the mineral 30 may be mixed into a protective layer applied to the surface of the natural leather. Furthermore, a separate layer containing the mineral 30 may be provided between the natural leather or synthetic leather skin layer 1d and the heater layer 1c.

[0030] Furthermore, although the present embodiment has been described with reference to a configuration in which the heater wire 22 is provided as a heating element in the steering section 1 of the steering wheel 10, the present invention is not limited to this. That is, the same effect as described above can be obtained by providing another general-purpose heater that generates heat when energized inside the steering section 1. However, in order to prevent the tactile feel of the steering section 1 from deteriorating, it is preferable to use a heater wire 22 with a small volume as in the present embodiment. [Explanation of symbols]

[0031] 1...steering part, 1a...core material, 1c...heater layer, 1d...surface layer, 1d4...protective layer, 2...boss part, 10...steering wheel, 22...heater wire, 30...ore

Claims

1. a steering section that is gripped and steered by a driver, the steering section being formed by laminating a plurality of layers on a core material, and a heating element that generates heat when electricity is passed through the plurality of layers; a boss portion disposed inside the steering portion and connected to a steering central shaft of the steering portion; A steering wheel comprising: The plurality of layers of the steering section include an ore-containing layer that is disposed on a surface side of the heating element and contains an ore that radiates far infrared rays, a heater wire as the heating element is sandwiched between the base materials on the core material side and the surface layer side; A steering wheel characterized in that the density of the base material on the surface layer side is higher than the density of the base material on the core material side.

2. 2. The steering wheel according to claim 1, wherein the ore is mixed into paint applied to the surface of the steering portion.

3. 3. The steering wheel according to claim 1, wherein the ore-containing layer contains a plurality of types of ores.

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