Steering device

Abstract

To provide a steering device capable of curbing a deterioration in assemblability of a heating element while using a carbon nano-tube as the heating element.SOLUTION: A steering wheel 10 comprises: a gripping part 1 for being gripped by a driver M during steering; a heating element which is provided within the gripping part 1 and which is energized to generate heat, that is, a heating element which is made of a carbon nano-tube 22 supported by a knitted material 20 formed by knitting a fiber; and an electrode part 20b which energizes the heating element.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a steering device that includes a heating element inside a grip portion that is gripped by a driver. [Background technology]

[0002] As a countermeasure against the cold in winter, a configuration has been known in which a heating element that generates heat when electricity is passed through it is provided inside a grip portion of a steering wheel, which is a steering device and is held by a driver, as described in Patent Document 1. The heating element described in Patent Document 1 is made of a metal heater wire provided on a resin substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-002101 Summary of the Invention [Problem to be solved by the invention]

[0004] Carbon nanotubes are lightweight and have excellent electrical and thermal conductivity, as well as far-infrared radiation heat. Therefore, carbon nanotubes can be used instead of metals as heating elements. However, carbon nanotubes are a hard material. Therefore, when carbon nanotubes are simply uniformly supported on a substrate and then assembled to a gripping part, the carbon nanotubes may crack when the substrate is bent to fit the curved surface of the gripping part, which may result in poor assembly of the heating element.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a steering device that uses carbon nanotubes as a heating element and that can prevent deterioration in the assembly of the heating element. [Means for solving the problem]

[0006] A typical configuration of a steering device according to the present invention for solving the above-mentioned problems is characterized in that the steering device is mounted on a moving body and comprises a gripping portion that is gripped by the driver when steering, a heating element that is provided inside the gripping portion and generates heat when electricity is passed through it, the heating element being made of carbon nanotubes carried on a knitted body formed by weaving fibers, and an electrode portion that passes electricity through the heating element.

[0007] According to the present invention, in a steering device, carbon nanotubes are used as a heating element, and deterioration in the assembly of the heating element can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a view of the area around the driver's seat of a vehicle equipped with a steering wheel, viewed from the left side. [Figure 2] FIG. [Figure 3] FIG. 3 is a cross-sectional view of a grip portion of a steering wheel. [Figure 4] FIG. 2 is a perspective view of the knitted body of the gripping portion. [Figure 5] FIG. 1 is a development view of the knitted body laid out flat. [Figure 6] 1A and 1B are a cross-sectional view and an enlarged view of a knitted body. [Figure 7] 10 is a schematic diagram showing a state in which the knitted body is assembled to a gripping part. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] A steering device according to an embodiment of the present invention will be described below with reference to the drawings. Note that the dimensions, materials, shapes, relative positions, and the like of the components described below are not intended to limit the scope of the present invention unless otherwise specified.

[0010] Fig. 1 is a view from the left side of the driver's seat 59 and its surroundings of a vehicle 50 (mobile body) equipped with a steering wheel 10 as a steering device, with a driver M seated in the driver's seat 59 indicated by a two-dot chain line. Fig. 2 is a front view of the steering wheel 10, with the upper cover 3x made transparent to make the internal configuration easier to see and only the outline indicated by a two-dot chain line. Fig. 3 is a cross-sectional view of the grip portion 1 of the steering wheel 10 taken along the A1-A1 cross section shown in Fig. 2.

[0011] In the following description, unless otherwise specified, the directions described with respect to the steering wheel 10 refer to the directions when the steering wheel 10 is mounted on the vehicle 50 shown in Fig. 1. In other words, the left-right direction refers to the left and right directions of the vehicle 50 on which the steering wheel 10 is mounted, specifically the left and right directions as seen from the driver M. The front-rear direction generally corresponds to the front and rear directions of the vehicle 50, specifically the front and rear directions as seen from the driver M. The up-down direction generally corresponds to the up and down directions in the vertical direction.

[0012] 1, the steering wheel 10 is mounted on the vehicle 50 by being connected to a steering shaft 55 of the vehicle 50. The vehicle 50 is equipped with a steering column 56 that is made up of a column tube 56a that partially covers the outer periphery of the steering shaft 55 and supports the steering shaft 55, and a column cover 56b that covers the portion of the steering shaft 55 that protrudes rearward from an instrument panel 57. The steering wheel 10 is attached to the rear end 55a of the steering shaft 55 that protrudes rearward from the instrument panel 57.

[0013] 2 and 3, steering wheel 10 includes a grip portion 1 that is gripped by driver M when steering vehicle 50, a hub portion 2 that is disposed inside grip portion 1 and connected to steering shaft 55, and spoke portions 3 that connect grip portion 1 and hub portion 2. In addition, a lower cover 4 is provided on the front side of steering wheel 10 (see FIG. 1).

[0014] The grip portion 1 is a portion also called a rim portion, and although it has a circular ring shape in this embodiment, it may have other shapes. The driver grips the grip portion 1 and rotates the grip portion 1 around the steering shaft 55 to change the traveling direction of the vehicle 50.

[0015] The grip part 1 is formed by laminating a metal core 1a made of an aluminum alloy or the like, a covering layer 1b made of a cushioning material such as polyurethane foam, and a skin layer 1c disposed on the outermost surface of the grip part 1. Between the covering layer 1b and the skin layer 1c, a knitted body 20 carrying carbon nanotubes 22 as a heating element that generates heat when electricity is applied is provided. In other words, the knitted body 20 is provided inside the grip part 1.

[0016] The skin layer 1c is divided into four parts in the rotational direction of the grip part 1 and is adhered with an adhesive to the outer periphery of the knit body 20. The skin layer 1c is made of insulating leather, resin, or the like, and protects the driver M who grips the grip part 1 from electric current when the carbon nanotubes 22 are energized. The detailed configuration of the knit body 20 will be described later.

[0017] The hub portion 2 is a metal member connected to the steering shaft 55, and has an axial hole 2a through which the steering shaft 55 is inserted. The rear end portion 55a of the steering shaft 55 is inserted into the axial hole 2a and fitted together, and then fastened with a nut, thereby connecting the hub portion 2 and the steering shaft 55. The hub portion 2 is integrally molded with a metal core material 2b.

[0018] The spokes 3 are composed of left and right spokes 3a and 3b, which extend laterally from the hub 2, respectively, and a lower spoke 3c that extends downward. The left and right spokes 3a and 3b have metal cores 3a1 and 3b1 that extend laterally, respectively, connecting the core 1a of the handle 1 to the core 2b of the hub 2. The lower spoke 3c has a metal core 3c1 that extends downward from the core 2b of the hub 2, branches out laterally, and connects to the core 1a of the handle 1. The left, right, and lower spokes 3a and 3b have upper covers 3x made of resin that cover the cores 3a1, 3b1, and 3c1.

[0019] Here, the core material 1a of the grip portion 1, the core material 2b of the hub portion 2, and the core materials 3a1, 3b1, and 3c1 of the spoke portions 3 are integrally molded by die-casting, thereby connecting the grip portion 1, the hub portion 2, and the spoke portions 3. However, the core material 1a of the grip portion 1, the core material 2b of the hub portion 2, and the core materials 3a1, 3b1, and 3c1 of the spoke portions 3 may be formed separately and then connected by welding or the like.

[0020] Next, the detailed configuration of the knit body 20 will be described. Fig. 4 is a perspective view of the knit body 20. Fig. 5 is a developed view of the knit body 20 laid out flat. Fig. 6A is a cross-sectional view of the knit body 20 taken along the A2-A2 cross section shown in Fig. 5. Fig. 6B is an enlarged view of region X of the knit body 20 shown in Fig. 5. Fig. 7 is a schematic view showing the state when the knit body 20 is assembled to the gripping part 1.

[0021] As shown in FIGS. 4 to 7, the knitted body 20 is an annular member formed by circular knitting (weft knitting) stretchable fibers 21, such as urethane resin or elastomer. An opening 20a is formed in the inner periphery of the knitted body 20. The opening 20a is formed around the entire circumference of the annular knitted body 20. When the knitted body 20 is assembled to the gripping part 1, the core material 1a and the covering layer 1b of the gripping part 1 are housed inside the opening 20a. In other words, the knitted body 20 is a bag-shaped member with the opening 20a as the bag opening, and is assembled to the gripping part 1 by being placed over the core material 1a and the covering layer 1b so that the core material 1a and the covering layer 1b are housed inside the bag.

[0022] The knit body 20 is also impregnated with carbon nanotubes 22. Specifically, the knit body 20 is immersed in a dispersion liquid containing a material such as a stretchable urethane resin or elastomer, in which the carbon nanotubes 22 are dispersed, thereby impregnating the knit body 20 with the carbon nanotubes 22. In this way, the knit body 20 supports the carbon nanotubes 22. Note that the method for supporting the carbon nanotubes 22 on the knit body 20 is not limited to this, and other methods may be used, such as applying the dispersion liquid to the knit body 20 or thermally transferring or silk-screen printing the dispersion liquid in ink onto the knit body 20.

[0023] Furthermore, some of the fibers 21 forming the knit body 20 contain conductive yarns, which constitute electrode portions 20b for conducting electricity through the carbon nanotubes 22. An anode 20b1 of the electrode portion 20b is disposed on the inner circumferential portion 1x (FIG. 2) side of the gripping portion 1, over the entire area in the rotational direction of the gripping portion 1. A cathode 20b2 of the electrode portion 20b is disposed on the outer circumferential portion 1x (FIG. 2) side of the gripping portion 1, over the entire area in the rotational direction of the gripping portion 1. In other words, the anode 20b1 and the cathode 20b2 of the electrode portion 20b are disposed side by side in the circumferential direction of the gripping portion 1 when the knit body 20 is assembled to the gripping portion 1. Lead wires 23 electrically connected to a control device (not shown) are connected to the anode 20b1 and the cathode 20b2 by crimping or the like for the knit. The circumferential direction of the grip portion 1 here is the direction in which the driver M places his / her fingers when gripping the grip portion 1, and the rotation direction is the direction in which the grip portion 1 moves when the steering wheel 10 is turned for steering.

[0024] When assembling the knitted body 20 to the gripping part 1, the assembling worker first applies adhesive to the outer periphery 1b1 of the coating layer 1b. Next, a portion of the knitted body 20 carrying the carbon nanotubes 22 is hooked onto the outer periphery 1b1 of the coating layer 1b. Then, as shown in FIG. 7, the worker stretches the knitted body 20 by hand to widen the opening 20a, and places the knitted body 20 over the outer periphery 1b1 of the coating layer 1b so that the core material 1a and the coating layer 1b of the gripping part 1 are accommodated within the opening 20a. In this manner, the knitted body 20 is assembled to the gripping part 1.

[0025] Here, when the knitted body 20 is assembled to the gripping part 1, the weft direction of the circular knitted body 20 is arranged along the rotation direction of the gripping part 1. In other words, the direction in which the weft knit stitches of the knitted body 20 are connected is along the rotation direction of the gripping part 1. This makes it easier for the knitted body 20 to stretch when assembled to the gripping part 1, making it easier to assemble the knitted body 20 to the gripping part 1. Note that the longitudinal direction of the knitted body 20 shown in FIG. 5 corresponds to the rotation direction of the gripping part 1.

[0026] To heat the grip portion 1, the driver M first operates a switch (not shown) mounted on the vehicle 50. In response to this, the control device controls a power supply (not shown) mounted on the vehicle 50 to apply a voltage to the electrode portion 20b. This causes a current to flow between the anode 20b1 and the cathode 20b2 of the electrode portion 20b, causing the carbon nanotubes 22 to become electrically conductive and generate heat, thereby heating the grip portion 1. In this way, the hands of the driver M holding the grip portion 1 are warmed.

[0027] As described above, the heating element provided inside the grip part 1 is constructed from carbon nanotubes 22 carried by the knitted body 20, which provides the following effects. Specifically, carbon nanotubes 22 are lightweight and have excellent electrical and thermal conductivity, and far-infrared radiation heat effects. On the other hand, carbon nanotubes 22 are hard materials. Therefore, when carbon nanotubes 22 are used as the heating element, there is a risk that the assembly of the heating element to the grip part 1 will be impaired, for example, the carbon nanotubes 22 may break when being fitted to the curved surface of the grip part 1 during assembly.

[0028] In contrast to this, in this embodiment, the carbon nanotubes 22 are supported on the knitted body 20, which has excellent elasticity, and then the knitted body 20 is assembled to the gripping portion 1, thereby assembling the carbon nanotubes 22 to the gripping portion 1. In this way, the elasticity of the knitted body 20 can be utilized to easily make the carbon nanotubes 22 conform to the curved surface of the gripping portion 1, and the carbon nanotubes 22 can be easily assembled to the gripping portion 1. Therefore, with the steering wheel 10 of this embodiment, it is possible to use the carbon nanotubes 22 as a heating element while preventing deterioration in the ease of assembling the heating element. Note that although the knitted body 20 is generally said to have low strength, since the knitted body 20 supports the carbon nanotubes 22, which have high strength, the strength of the knitted body 20 is compensated for by the carbon nanotubes 22.

[0029] Furthermore, the knitted body 20 is assembled to the gripping part 1 by covering the core 1a of the gripping part 1 so that the core 1a of the gripping part 1 is accommodated within the opening 20a, in other words, the inside of the bag of the bag-shaped knitted body 20. With this configuration, the knitted body 20 carrying the carbon nanotubes 22 can be easily assembled to the gripping part 1 in one go. If this is not taken into consideration, it is not necessary to make the knitted body 20 bag-shaped as in this embodiment, and for example, multiple knitted bodies 20 may be assembled to the gripping part 1 by being attached to the outer periphery 1b1 of the covering layer 1b with an adhesive or the like.

[0030] Furthermore, the anode 20b1 and the cathode 20b2 of the electrode portion 20b of the knit body 20 are arranged side by side in the circumferential direction of the grip portion 1 when the knit body 20 is assembled to the grip portion 1. With this configuration, the electrode portion 20b can be arranged over the entire area of ​​the steering wheel 10 in the rotational direction when the steering wheel 10 is viewed from the front, so the steering wheel 10 can be heated evenly and thermal efficiency can be improved. If this point is not taken into consideration, the anode 20b1 and the cathode 20b2 may be arranged side by side in the rotational direction of the grip portion 1. Furthermore, although forming the knit body 20 by circular knitting makes it easier to ensure elongation, the knit body 20 may also be formed by knitting using other knitting methods.

[0031] Furthermore, in this embodiment, when the knit body 20 is assembled to the gripping portion 1, the weft direction of the circularly knitted knit body 20 is arranged along the rotation direction of the gripping portion 1, which makes it easier to assemble the knit body 20 to the gripping portion 1. Here, in order to further improve the ease of assembly of the knit body 20 to the gripping portion 1, the knitting method or stitch direction of the knit body 20 may be configured to be partially changed. For example, in the inner peripheral portion 1x of the gripping portion 1, it is easier to assemble the knit body 20 to the gripping portion 1 if the knit body 20 stretches in the circumferential direction rather than in the rotation direction of the gripping portion 1. Therefore, the weft direction of the portion of the knit body 20 that is arranged in the inner peripheral portion 1x of the gripping portion 1 may be arranged to be along the circumferential direction of the gripping portion 1. Furthermore, only the portion of the knit body 20 that requires strength may be woven rather than knitted.

[0032] In the present embodiment, in order to enhance the stretchability of the knitted body 20, chemical fibers such as urethane-based resins or elastomers are used as the fibers 21 forming the knitted body 20, and a urethane-based resin or elastomer is used as the dispersion in which the carbon nanotubes 22 are dispersed. However, the present invention is not limited to this, and the knitted body 20 may be formed using other types of fibers or dispersions. That is, regardless of the material of the knitted body 20, a certain degree of stretchability can be obtained by using knitted fibers as the support for supporting the carbon nanotubes 22. This improves the ease of assembly to the gripping part 1 compared to a configuration in which the carbon nanotubes 22 are simply supported uniformly on a resin sheet and then assembled to the gripping part 1, or a configuration in which the carbon nanotubes 22 are supported on a woven fabric and then assembled to the gripping part 1. However, forming the knitted body 20 using highly stretchable fibers 21 and dispersions, as in the present embodiment, is preferable because it further improves the ease of assembly to the gripping part 1.

[0033] Furthermore, although the present embodiment has been described with respect to a configuration in which the carbon nanotubes 22 are supported on the knitted body 20 formed using fibers different from the carbon nanotubes 22, the present invention is not limited to this. That is, the knitted body 20 may be formed by weaving fibrous carbon nanotubes 22, and this knitted body 20 may be assembled to the gripping part 1 as a heating element in the same manner as above. Even with this configuration, the carbon nanotubes 22 can be made stretchable by being knitted, and the same effect as above can be obtained.

[0034] In the present embodiment, the carbon nanotubes 22 carried by the knitted body 20 are used as a heating element to warm the hands of the driver M who is gripping the grip portion 1. However, the present invention is not limited to this, and the carbon nanotubes 22 carried by the knitted body 20 may be used as sensor electrodes of a capacitance-type grip sensor that detects the grip of the grip portion 1 by the driver M. Even with this configuration, deterioration in the ease of assembling the sensor electrode to the grip portion 1 can be suppressed, similar to the above-described configuration in which the carbon nanotubes 22 are used as a heating element.

[0035] Furthermore, although the present embodiment has been described with reference to a configuration in which conductive threads are used as the electrode portions 20b for energizing the carbon nanotubes 22, the present invention is not limited to this. For example, the same effect as described above can be obtained by providing the electrode portions 20b by directly printing a conductive material on the knitted body 20. In this case, it is preferable that the conductive material be a stretchable material.

[0036] Furthermore, in this embodiment, the vehicle 50 is used as an example of a moving body on which the steering wheel 10 is mounted, but the present invention is not limited to this. That is, the moving body on which the steering wheel 10 is mounted is not limited to the vehicle 50 as long as it is an object that can carry a person and move, and may be, for example, another vehicle such as a ship or an aircraft. [Explanation of symbols]

[0037] 1...gripping portion, 1a...core material, 10...steering wheel (steering device), 20...knitted body, 20b...electrode portion, 20b1...anode, 20b2...cathode, 22...carbon nanotube (heating element), 50...vehicle (moving object), M...driver

Claims

1. In a steering device mounted on a moving body, a grip portion that is gripped by a driver when steering; a heating element provided inside the gripping portion, which generates heat when electricity is applied, and which is made of carbon nanotubes carried on a knitted body formed by weaving fibers; an electrode portion for energizing the heating element; A steering device comprising:

2. The grip portion includes a core material, 2. The steering device according to claim 1, wherein the knitted body is formed in a bag shape and is assembled to the grip portion by covering the core material so as to house the core material inside the bag.

3. 3. The steering device according to claim 1, wherein the knitted body is formed by weft knitting, and the weft direction of the weft knitting is arranged along the rotation direction of the grip portion.

4. 4. The steering device according to claim 3, wherein the knitted body is formed by circular knitting.

5. 3. The steering device according to claim 1, wherein the anode and cathode of the electrode portion are arranged side by side in the circumferential direction of the grip portion.

6. 6. The steering device according to claim 5, wherein the electrode portion is a conductive thread that constitutes at least a part of the fibers that form the knitted body.

7. In a steering device mounted on a moving body, a grip portion that is gripped by a driver when steering; a heating element provided inside the gripping portion, which generates heat when electricity is applied, and which is made of a knitted body formed by weaving fibrous carbon nanotubes; an electrode portion for energizing the heating element; A steering device comprising:

8. The grip portion includes a core material, The steering device according to claim 7, characterized in that the knitted body is formed in a bag shape and is assembled to the gripping portion by covering the core material so as to house the core material inside the bag.

9. 9. The steering device according to claim 7, wherein the knitted body is formed by weft knitting, and the weft direction of the weft knitting is arranged along the rotation direction of the grip portion.

10. The steering device according to claim 9, wherein the knitted body is formed by circular knitting.

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