STEERING DEVICE

A steering device includes a rotation part and a gripping part; the gripping part includes a core metal part symmetrical across the rotation part, and a covering part that covers the core metal part; the covering part has a first conductive part on one side with respect to a symmetrical plane of the core metal part, formed of a material having conductivity, and a second conductive part on the other side with respect to the symmetrical plane of the core metal part, formed of a material having conductivity; the first and the second conductive parts are arranged independently from each other; and the steering device further includes a harness electrically connecting the first and the second conductive parts, and a detector that detect gripping condition of the gripping part based on change in capacitance generated in the first conductive part and the second conductive part.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the priority based on Japanese Patent Applications No. 2023-129757 filed on Aug. 9, 2023 and No. 2024-109474 filed on Jul. 8, 2024, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

Field

The present disclosure relates to a steering device.

Related Art

Japanese Patent Laid-Open Publication No. 2016-165940 discloses the steering wheel having the function of detecting whether the steering wheel is gripped by an occupant. The steering wheel according to JP2016-165940A includes a rim part to be gripped and rotated by an occupant. The rim part has a substantially annular shape when viewed from the occupant. The core metal serving as the skeletal part of the rim part is surrounded by a soft covering part formed of polyurethane foam. The soft covering part is surrounded by an outer cover made up of three layers formed of different materials. The outermost layer of the outer cover is a soft layer formed of polyurethane foam. The intermediate layer of the outer cover is a base cloth formed of fibers. The innermost layer is a conductive layer formed of a conductive material. The conductive layer is a coating film formed by coating the base cloth on its inner side with a coating material having conductivity. The conductive layer provides conductivity to the entire outer cover, so that the outer cover functions as an electrode. When an occupant grips the rim part, a capacitance between the outer cover and the occupant then changes from the capacitance when the rim part is not gripped. A detection substrate detects the gripping condition of the rim part, on the basis of the change in capacitance.

SUMMARY

The steering wheel according to JP2016-165940A has the conductive layer arranged on the entire periphery of the rim part having a substantially ring-like shape. In the conductive layer, the potential at the portion where a power source is connected may differ from that at a portion which is away from the power connection portion. In some cases, the conductive layer may not be ideally and uniformly configured throughout. Accordingly, the steering wheel according to JP2016-165940A may experience variability in detection accuracy of gripping depending on differences in the gripped portions by an occupant.

The present disclosure may be embodied in the following aspects.

In one aspect of the present disclosure, a steering device is provided. The steering device, which is mounted on a moving object, includes a rotation part attached to the moving object so as to be rotatable, and a gripping part connected to the rotation part; the gripping part includes a core metal part configured to be symmetrical across the rotation part, and a covering part configured to at least partially cover the core metal part; the covering part has a first conductive part arranged on one side with respect to a symmetrical plane of the core metal part, formed of a material having conductivity, and a second conductive part arranged on the other side with respect to the symmetrical plane of the core metal part, formed of a material having conductivity; the first conductive part and the second conductive part are arranged independently from each other; the steering device further includes a harness electrically connecting the first conductive part and the second conductive part, and a detector electrically connected to the first conductive part and the second conductive part via the harness, configured to detect gripping condition of the gripping part based on change in capacitance generated in at least one of the first conductive part and the second conductive part.

The present disclosure may be embodied in various aspects, for example, a vehicle equipped with the steering device, and a method of producing the steering device.

DETAILED DESCRIPTION

A. First Embodiment

FIG.1is an explanatory diagram illustrating a vehicle VW equipped with a steering device1in the present embodiment. InFIG.1, the steering device1is depicted in a simplified form.FIG.1shows an X axis, a Y axis, and a Z axis, which are mutually orthogonal. The X axis extends along the left-right direction of the vehicle VW. The direction from the front to the back of the paper ofFIG.1is defined as the positive direction of the X axis. The Y axis is parallel to the extension direction of a rotation shaft AR which will be described later. The Z axis is orthogonal to the X axis and the Y axis. These also apply toFIG.2toFIG.5, andFIG.8toFIG.10which will be described later. InFIG.1, the vertical direction is represented by a VU axis. The upward direction in the vertical direction is defined as the positive direction of the VU axis.

FIG.2shows the steering device1shown inFIG.1when viewed toward the positive Y direction. InFIG.2, the steering device1is depicted in a simplified form.FIG.3shows the steering device1shown inFIG.2without an outer cover25. The outer cover25will be described later. The steering device1shown inFIG.1enables the steering of the vehicle VW through operation by a driver DR who is an occupant of the vehicle VW. The steering device1is connected to the rotation shaft AR which protrudes from the inside of a front part FRO of the vehicle VW (refer to the rotation shaft AR inFIG.1). The steering device1is attached to the vehicle VW, via the rotation shaft AR. As shown inFIG.2andFIG.3, the steering device1includes a rotation part10, a gripping part20, a harness30, and a detector40. InFIG.2andFIG.3, the rotation shaft AR shown inFIG.1is omitted. The rotation shaft AR is omitted also inFIG.4,FIG.9, andFIG.10.

The rotation part10is attached to the vehicle VW so as to be rotatable. Specifically, the rotation shaft AR shown inFIG.1is inserted through and fixed to a hole101which is formed in the rotation part10, so that the rotation part10is attached to the vehicle VW so as to be rotatable. The rotation part10shown inFIG.2is connected to the gripping part20. In the present embodiment, in the state where the rotation part10is not rotated, the rotation part10is symmetrical with respect to the plane including the Y axis and the Z axis. The position of the rotation part10where the symmetrical plane of the rotation part10includes the Y axis and the Z axis is referred to as “reference angle position of the rotation part10”. The state where the rotation part10is positioned at the reference angle position of the rotation part10is expressed as “the rotation part10is at the reference angle position”.FIG.2shows the rotation part10which is at the reference angle position. These also apply toFIG.3toFIG.5,FIG.9, andFIG.10.

FIG.4shows the steering device1shown inFIG.3without a first covering part22and the rotation part10. InFIG.4, the hole101formed in the rotation part10is illustrated for the sake of convenience. The first covering part22will be described later. The gripping part20is the part configured to be gripped by the driver DR who is an occupant of the vehicle VW. As shown inFIG.2toFIG.4, the gripping part20includes a core metal part21, the first covering part22, and the outer cover25.

The core metal part21shown inFIG.4is covered by the first covering part22and the outer cover25(refer toFIG.2andFIG.3). As shown inFIG.2toFIG.4, in the present embodiment, the core metal part21is configured to be symmetrical across the rotation part10. In the present embodiment, the core metal part21is configured to be symmetrical with respect to a first symmetrical plane PS1which is the plane including the Y axis and the Z axis, in the state where the rotation part10is at the reference angle position.

FIG.5shows the core metal part21ofFIG.4when viewed toward the positive X direction.FIG.5shows the VU axis. In the present embodiment, the core metal part21is configured to be symmetrical with respect to a second symmetrical plane PS2which is the plane including the X axis and the Z axis, in the state where the rotation part10is at the reference angle position. As shown inFIG.5, when the core metal part21is viewed in the X-axis direction, the second symmetrical plane PS2passes through the center of the core metal part21in the Y direction. In the present embodiment, the surface of the core metal part21on the side facing an occupant is defined as a front-face part21A, and the surface on the side opposite to the front-face part21A is defined as a rear-face part21B. Specifically, as shown inFIG.1andFIG.5, the surface of the core metal part21on one side facing the occupant with respect to the second symmetrical plane PS2is defined as the front-face part21A. As shown inFIG.1andFIG.5, the surface of the core metal part21on the other side with respect to the second symmetrical plane PS2is defined as the rear-face part21B.

As shown inFIG.3andFIG.5, in the present embodiment, in the state where the rotation part10is at the reference angle position, a topmost part21acorresponding to the highest part of the core metal part21in the vertical direction is positioned on the upper side in the vertical direction with respect to the rotation part10. In the state where the rotation part10is at the reference angle position, a bottommost part21bcorresponding to the lowest part of the core metal part21in the vertical direction is positioned on the lower side in the vertical direction with respect to the rotation part10. In the present specification, “the upper side in the vertical direction with respect to the rotation part10” means the range upper than the range occupied by the rotation part10in the vertical direction. The state where a certain object A “is positioned on the upper side in the vertical direction with respect to the rotation part10” does not mean that the object A is positioned right above the rotation part10in the vertical direction. In other words, when the object A is projected in the vertical direction, the position of the object A in the horizontal direction may not overlap with the position of the rotation part10. Similarly, in the present specification, “the lower side in the vertical direction with respect to the rotation part10” means the range lower than the range occupied by the rotation part10in the vertical direction. The state where a certain object A “is positioned on the lower side in the vertical direction with respect to the rotation part10” does not mean that the object A is positioned right below the rotation part10in the vertical direction. In other words, when the object A is projected in the vertical direction, the position of the object A in the horizontal direction may not overlap with the position of the rotation part10. As shown inFIG.4, in the present embodiment, the core metal part21has an annular shape when viewed in the Y direction. The core metal part21includes a core metal210and a soft covering part211.

The core metal210serves as the frame part of the core metal part21. The core metal210is covered by the soft covering part211. As shown inFIG.2toFIG.4, the core metal210is configured to be symmetrical across the rotation part10. In the present embodiment, the core metal210has an annular shape when viewed in the Y direction. The core metal210is formed of an alloy such as iron, aluminum, or magnesium. The core metal210is connected to the fixing member which is arranged on the inner periphery of the core metal210so as to extend in the X-axis direction. The fixing member is not illustrated in the figures. The fixing member is formed of the same material as the core metal210. The fixing member has a hole allowing connection with the rotation shaft AR described above, when viewed in the Y-axis direction. The soft covering part211protects the core metal210by covering the core metal210. In the present embodiment, the soft covering part211is formed of polyurethane foam.

FIG.6shows the first covering part22in the state not covering the core metal part21, and the harness30.FIG.7is a schematic diagram ofFIG.6. InFIG.7, the detector40is illustrated to facilitate understanding. The first covering part22, along with the outer cover25, functions as an electrode. As shown inFIG.3, in the present embodiment, the first covering part22is arranged along the outer periphery and the inner periphery of the core metal part21, when viewed in the Y-axis direction. The first covering part22is positioned from the topmost part21aof the core metal part21to the bottommost part21b. In the present embodiment, the first covering part22covers the entire core metal part21. As shown inFIG.3,FIG.6, andFIG.7, the first covering part22includes a first detection part220and a second detection part230.

As shown inFIG.3, the first detection part220is arranged on one side with respect to the first symmetrical plane PS1of the core metal part21. As shown inFIG.3, in the present embodiment, the first detection part220is arranged on the positive X-direction side with respect to the first symmetrical plane PS1of the core metal part21. The first detection part220is arranged on the outer surface of the core metal part21so that, as shown inFIG.3, one end part220aof the first detection part220shown inFIG.6is in contact with the topmost part21aof the core metal part21. Moreover, the first detection part220is arranged on the outer surface of the core metal part21so that, as shown inFIG.3, the other end part220bof the first detection part220shown inFIG.6is in contact with the bottommost part21bof the core metal part21. As shown inFIG.6, the first detection part220, in the state not covering the core metal part21, has a substantially rectangular appearance. As shown inFIG.7, the first detection part220includes a first conductive part221, a first shield part222, a first insulating part223, a first conductive terminal224, and a first shield terminal225.

FIG.8shows the cross-sectional view of the steering device1shown inFIG.3along a line VIII-VIII. InFIG.8, the rotation part10is omitted. The first conductive part221, along with the outer cover25, functions as a detection electrode for detecting a capacitance between the first conductive part221and the driver DR. The first conductive part221is arranged on the outer surface of the core metal part21. As shown inFIG.8, the first shield part222and the first insulating part223are arranged between the first conductive part221and the core metal part21. In the present specification, the state where the first conductive part221is arranged on the outer surface of the core metal part21includes not only the case where the first conductive part221is arranged directly on the outer surface of the core metal part21, but also the case where at least one of the first shield part222and the first insulating part223is arranged between the first conductive part221and the core metal part21. This also applies to a second conductive part231which will be described later. As shown inFIG.3, the first conductive part221is arranged on the positive X-direction side corresponding to one side with respect to the first symmetrical plane PS1of the core metal part21.

The first conductive part221is formed of a material having conductivity. In the present embodiment, the first conductive part221is the coating film formed by coating the first insulting part223with a coating material having conductivity. A mixture of coating resin and powder of conductive carbon or metal oxide may be used as the coating material having conductivity. As shown inFIG.7andFIG.8, the first conductive part221includes a first front conductive part221aand a first rear conductive part221b.

As shown inFIG.8, the first front conductive part221ais arranged so as to be in contact with the front-face part21A of the core metal part21on the side facing the occupant. In the present specification, the state where the first front conductive part221ais arranged so as to be in contact with the front-face part21A of the core metal part21includes not only the case where the first front conductive part221ais in direct contact with the front-face part21A, but also the case where at least one of the first shield part222and the first insulating part223is arranged between the first front conductive part221aand the front-face part21A. Specifically, as shown inFIG.8, the first front conductive part221ais arranged on the negative Y-direction side corresponding to one side with respect to the second symmetrical plane PS2of the core metal part21. As shown inFIG.3, the first front conductive part221ais positioned from the vicinity of the topmost part21aof the core metal part21to the vicinity of the bottommost part21b. As shown inFIG.8, the first rear conductive part221bis arranged so as to be in contact with the rear-face part21B of the core metal part21on the opposite side of the front-face part21A. In the present specification, the state where the first rear conductive part221bis arranged so as to be in contact with the rear-face part21B of the core metal part21includes not only the case where the first rear conductive part221bis in direct contact with the rear-face part21B, but also the case where at least one of the first shield part222and the first insulating part223is arranged between the first rear conductive part221band the rear-face part21B. Specifically, the first rear conductive part221bis arranged on the positive Y-direction side corresponding to the other side with respect to the second symmetrical plane PS2of the core metal part21. The first rear conductive part221bis positioned from the vicinity of the topmost part21aof the core metal part21to the vicinity of the bottommost part21b. In the present embodiment, the first rear conductive part221bhas the same length as the length of the first front conductive part221a, along the outer periphery of the core metal part21.

The first shield part222shown inFIG.7andFIG.8has the function of shielding a capacitance between the core metal210and the first conductive part221. Although not illustrated, the first shield part222is grounded. As shown inFIG.8, the first shield part222is arranged on the surface of the first insulating part223opposite to the surface on which the first conductive part221is arranged. The shape of the first shield part222will be described later. The first shield part222is formed by coating the first insulting part223with a coating material containing a material having conductivity. The first shield part222is arranged between the core metal210and the first conductive part221, thereby enabling stable detection by use of the first conductive part221, as to whether the gripping part20is gripped.

The first insulating part223insulates the first conductive part221and the first shield part222. The first insulating part223is arranged between the first conductive part221and the first shield part222. As shown inFIG.6, the first insulating part223has a sheet-like shape. As shown inFIG.7andFIG.8, the first conductive part221is arranged on one side surface of the first insulating part223, while the first shield part222is arranged on the other surface thereof (refer to the frame illustrated with a broken line inFIG.7). As shown inFIG.8, in the state where the first covering part22covers the core metal part21, the other surface of the first insulating part223faces the core metal part21.

The first conductive terminal224shown inFIG.7electrically connects the first conductive part221and the harness30. The first conductive terminal224includes a first front conductive terminal224aand a first rear conductive terminal224b. The first front conductive terminal224aelectrically connects the first front conductive part221aand the harness30. In the present embodiment, the first front conductive terminal224ais positioned closer to the other end part220bof the first detection part220than to the one end part220a. The first rear conductive terminal224belectrically connects the first rear conductive part221band the harness30. In the present embodiment, the first rear conductive terminal224bis positioned closer to the other end part220bof the first detection part220than to the one end part220a.

The first shield terminal225electrically connects the first shield part222and the detector40. In detail, the first shield terminal225electrically connects the first shield part222and the detector40, via the harness30. The first shield terminal225includes a first front shield terminal225aand a first rear shield terminal225b. In the present embodiment, the first front shield terminal225ais positioned closer to the other end part220bof the first detection part220than to the one end part220a, and closer to the first front conductive part221athan to the first rear conductive part221b. In the present embodiment, the first rear shield terminal225bis positioned closer to the other end part220bof the first detection part220than to the one end part220a, and closer to the first rear conductive part221bthan to the first front conductive part221a.

As shown inFIG.3, the second detection part230is arranged on the other side with respect to the first symmetrical plane PS1of the core metal part21. In the present embodiment, the second detection part230is arranged on the negative X-direction side with respect to the first symmetrical plane PS1of the core metal part21. The second detection part230has the same shape and the same function as those of the first detection part220. The second detection part230in the present embodiment is configured to be symmetrical to the first detection part220with respect to the first symmetrical plane PS1. As shown inFIG.7, the second detection part230includes a second conductive part231, a second shield part232, a second insulating part233, a second conductive terminal234, and a second shield terminal235. In the description below of the second detection part230, the same configurations as those of the first detection part220may be omitted.

The second conductive part231corresponds to the first conductive part221. The second conductive part231, along with the outer cover25, functions as a detection electrode for detecting a capacitance between the second conductive part231and the occupant. The second conductive part231and the first conductive part221are arranged independently from each other. As shown inFIG.7, the second conductive part231in the state not covering the core metal part21is separated from the first conductive part221, not connected thereto. The second conductive part231is formed of a material having conductivity. In the present embodiment, the second conductive part231is the coating film formed by coating the second insulting part233with a coating material having conductivity. The second conductive part231includes a second front conductive part231aand a second rear conductive part231b.

The second front conductive part231acorresponds to the first front conductive part221a. The second front conductive part231ais arranged so as to be in contact with the front-face part21A of the core metal part21. The second rear conductive part231bcorresponds to the first rear conductive part221b. The second rear conductive part231bis arranged so as to be in contact with the rear-face part21B of the core metal part21. The second shield part232corresponds to the first shield part222. The second insulating part233corresponds to the first insulating part223.

The second conductive terminal234corresponds to the first conductive terminal224. The second conductive terminal234electrically connects the second conductive part231and the harness30. The second conductive terminal234includes a second front conductive terminal234aand a second rear conductive terminal234b. The second front conductive terminal234aelectrically connects the second front conductive part231aand the harness30. The second front conductive terminal234ais positioned closer to the other end part230bof the second detection part230than to the one end part230a. The second rear conductive terminal234belectrically connects the second rear conductive part231band the harness30. The second rear conductive terminal234bis positioned closer to the other end part230bof the second detection part230than to the one end part230a.

The second shield terminal235corresponds to the first shield terminal225. The second shield terminal235electrically connects the second shield part232and the detector40. The second shield terminal235includes a second front shield terminal235aand a second rear shield terminal235b. The second front shield terminal235ais positioned closer to the other end part230bof the second detection part230than to the one end part230a, and closer to the second front conductive part231athan to the second rear conductive part231b. The second rear shield terminal235bis positioned closer to the other end part230bof the second detection part230than to the one end part230a, and closer to the second rear conductive part231bthan to the second front conductive part231a.

The outer cover25shown inFIG.2covers the first covering part22. When the outer cover25is in contact with the first conductive part221and the second conductive part231of the first covering part22, the outer cover25, along with the first conductive part221and the second conductive part231, functions as a detection electrode. In the present embodiment, the outer cover25is formed of leather.

The harness30shown inFIG.7electrically connects the first conductive part221and the second conductive part231. In detail, the harness30electrically connects the first conductive terminal224connected to the first conductive part221, and the second conductive terminal234connected to the second conductive part231, thereby electrically connecting the first conductive part221and the second conductive part231. In other words, the harness30electrically connects the first conductive part221and the second conductive part231, via the first conductive terminal224and the second conductive terminal234. In the present embodiment, the harness30includes a first harness310and a second harness320. The first harness310electrically connects the first front conductive part221aand the second front conductive part231a. In the first harness310, one end thereof is in contact with the first front conductive terminal224a, the second front conductive terminal234a, the first front shield terminal225a, and the second front shield terminal235a, and the other end thereof is in contact with the detector40. The second harness320electrically connects the first rear conductive part221band the second rear conductive part231b. In the second harness320, one end thereof is in contact with the first rear conductive terminal224b, the second rear conductive terminal234b, the first rear shield terminal225b, and the second rear shield terminal235b, and the other end thereof is in contact with the detector40.

The detector40detects the gripping condition of the gripping part20, on the basis of the change in capacitance generated in at least one of the first conductive part221and the second conductive part231. The detector40is electrically connected to the first conductive part221and the second conductive part231, via the harness30. As shown inFIG.3, the detector40is arranged between the hole101formed in the rotation part10and the bottommost part21bof the core metal part21. The steering device1having the detector40arranged at the position described above has better appearance compared to another embodiment of the steering device1having the detector40arranged, for example, between the rotation part10and the topmost part21aof the core metal part21. In the present embodiment, as shown inFIG.7, the detector40includes a first detector410and a second detector420. Although only the detector40is illustrated inFIG.3, in reality the first detector410and the second detector420are arranged between the hole101formed in the rotation part10and the bottommost part21bof the core metal part21. As shown inFIG.7, the first detector410is electrically connected to the first front conductive part221aand the second front conductive part231a, the first front shield terminal225a, and the second front shield terminal235a, via the first harness310. The first detector410includes various circuits including an oscillation circuit, a resonance circuit, a detection circuit, and an amplification circuit, which are not illustrated.

When the gripping part20is gripped by an occupant, the capacitance between the occupant and at least one of the first front conductive part221aand the second front conductive part231athen changes from the capacitance of the state where the gripping part20is not gripped, and the resonant frequency changes. The first detector410modulates the changed resonant frequency using amplitude modulation, detects a signal in the detection circuit, amplifies the signal in the amplification circuit, and outputs it to an ECU (Electronic Control Unit) not shown of the vehicle VW as a voltage. The ECU detects the gripping condition of the gripping part20, on the basis of whether the voltage value is larger than a predetermined threshold. The voltage values of the first shield part222and the second shield part232detected by the first detector410are used to output an accurate voltage based on the capacitance between the occupant and one of the first front conductive part221aand the second front conductive part231a. The second detector420is electrically connected to the first rear conductive part221band the second rear conductive part231b, the first rear shield terminal225b, and the second rear shield terminal235b, via the second harness320. The second detector420has the same configurations as those of the first detector410.

In the steering device1in the present embodiment, the first conductive part221and the second conductive part231are positioned on the sides opposite to each other with respect to the first symmetrical plane PS1, and are arranged independently from each other. Accordingly, each of the conductive parts has a smaller area compared to an embodiment where one conductive part covers the entire outer periphery of the core metal part21. As a result, each of the first conductive part221and the second conductive part231is less likely to experience variability in detection accuracy depending on differences in the gripped portions.

The steering device1includes the harness30which electrically connects the first conductive part221and the second conductive part231, wherein the detector40is electrically connected, via the harness30, to the first conductive part221and the second conductive part231. The steering device1having the configurations described above is less likely to experience a decrease in work efficiency when the first covering part22is arranged on the core metal part21in the production of the steering device1, compared to an example embodiment in which the terminal electrically connecting the first conductive part221and the detector40and the terminal electrically connecting the second conductive part231and the detector40are not connected via the harness30. The steering device1in the present embodiment includes the first harness310which electrically connects the first front conductive part221aand the second front conductive part231a, and the second harness320which electrically connects the first rear conductive part221band the second rear conductive part231b. The steering device1in the present embodiment is less likely to experience a decrease in work efficiency when the first covering part22is arranged on the core metal part21in the production of the steering device1, compared to an example embodiment without the first harness310or the second harness320.

In the present specification, the state where the first conductive part221is arranged on one side with respect to the symmetrical plane of the core metal part21while the second conductive part231is arranged on the other side means the state where the first conductive part221is arranged on one side while the second conductive part231is arranged on the other side, with respect to the first symmetrical plane PS1corresponding to the symmetrical plane of the core metal part21configured to be symmetrical across the rotation part10. The symmetrical plane in the above description does not include the second symmetrical plane PS2.

B. Second Embodiment

FIG.9is a schematic diagram illustrating a steering device1B in the second embodiment.FIG.9corresponds toFIG.2. The second embodiment differs from the first embodiment in the shape of an outer cover25B, and in that the gripping part20includes a first light source51and a second light source52, and that a second covering part22B, instead of the first covering part22, covers the core metal part21. The second embodiment has the same configurations, except for the above, as those of the first embodiment. Accordingly, the same configurations are denoted by the same reference signs, and the detailed descriptions thereof are omitted.

The first light source51and the second light source52are configured to glow according to the situation of the vehicle VW. The first light source51and the second light source52in the present embodiment glow in order to prompt the driver DR to grip the gripping part20. The first light source51and the second light source52are arranged on the outer surface of the core metal part21, on the upper side in the vertical direction with respect to the rotation part10in the state where the rotation part10is at the reference angle position. In the present embodiment, the first light source51and the second light source52are arranged in line in the X direction on either side of the topmost part21aof the core metal part21. The first light source51and the second light source52are arranged on the front-face part21A of the core metal part21on the side facing the occupant. In the present embodiment, the first light source51and the second light source52are LEDs. The first light source51and the second light source52are electrically connected to the ECU of the vehicle VW, and receive a signal from the ECU and glow.

FIG.10is an explanatory diagram illustrating the second covering part22B.FIG.11shows the second covering part22B in the state not covering the core metal part21. The second covering part22B has the same configurations as those of the first covering part22. The second covering part22B includes a first detection part220B and a second detection part230B. The differences from the first covering part22are described below. The second covering part22B is arranged on an area of the core metal part21other than the first light source51and the second light source52. The second covering part22B differs from the first covering part22in the shapes of a first front conductive part221Ba and a second front conductive part231Ba.

As shown inFIG.11, in the first front conductive part221Ba of the second covering part22B, an end part221Baa which is positioned on the side closer to the topmost part21aof the core metal part21ofFIG.10than to the bottommost part21bis positioned closer to the bottommost part21b, compared to an end part221Bba of a first rear conductive part221Bb. In other words, in the second covering part22B in the state covering the core metal part21, the first front conductive part221Ba of the second covering part22B has a length along the outer periphery of the core metal part21shorter than the length of the first rear conductive part221Bb (refer toFIGS.10and11). As shown inFIG.11, a first shield part222B and a first insulating part223B are configured to have lengths corresponding to the length along the outer periphery of the core metal part21of the first front conductive part221Ba. Accordingly, as shown inFIG.10, there is a part not covered by the first front conductive part221a, out of the front-face part21A of the surface of the core metal part21facing the occupant and on the portion above the rotation part10in the vertical direction. The first light source51shown inFIG.9is arranged on the part described above. The first rear conductive part221Bb of the second covering part22B has the same length along the outer periphery of the core metal part21as the length of the first rear conductive part221bof the first covering part22shown inFIG.3, along the outer periphery of the core metal part21.

Similarly, in the second front conductive part231Ba of the second covering part22B, an end part231Baa which is positioned on the side closer to the topmost part21aof the core metal part21than to the bottommost part21bis positioned closer to the bottommost part21b, compared to an end part231Bba of a second rear conductive part231Bb. In other words, in the second covering part22B in the state arranged on the core metal part21, the second front conductive part231Ba of the second covering part22B has a length along the outer periphery of the core metal part21shorter than the length of the second rear conductive part231Bb of the second covering part22B. As shown inFIG.11, a second shield part232B and a second insulating part233B are configured to have lengths corresponding to the length along the outer periphery of the core metal part21of the second front conductive part231Ba. Accordingly, as shown inFIG.10, there is a part not covered by the first front conductive part221a, out of the front-face part21A of the surface of the core metal part21facing the occupant and, on the portion above the rotation part10in the vertical direction. The second light source52shown inFIG.9is arranged on the part described above. The second rear conductive part231Bb of the second covering part22B has the same length along the outer periphery of the core metal part21as the length of the second rear conductive part231bof the first covering part22, along the outer periphery of the core metal part21.

In the present embodiment, the angle of approx. 50 degrees is designated as an angle range A1formed between the first detection part220B and the second detection part230B, with the center of the hole101formed in the rotation part10as the vertex, on the plane including the X axis and the Z axis, when the steering device1with the rotation part10being at the reference angle position is viewed in the positive Y direction. The angle illustrated inFIG.10is not accurate.

As shown inFIG.9, the outer cover25B in the second embodiment is configured to cover the core metal part21and the second covering part22B, not to cover the first light source51or the second light source52.

In the steering device1B in the second embodiment, the gripping part20includes the first light source51, the second light source52, and the second covering part22B. The steering device1B with the gripping part20including the first light source51and the second light source52provides greater convenience because the light sources glow according to the condition of a moving object.

FIG.12is an explanatory diagram illustrating a third covering part22C in the third embodiment. As shown inFIG.12, the third embodiment differs from the first embodiment in that a steering device1C includes the third covering part22C, instead of the first covering part22. The third embodiment has the same configurations, except for the above, as those of the first embodiment. Accordingly, the same configurations are denoted by the same reference signs, and the detailed descriptions thereof are omitted. The third covering part22C has the same configurations as those of the first covering part22. In other words, the third covering part22C includes a first detection part220C and a second detection part230C. The differences from the first covering part22are described below.

Although not illustrated, the third covering part22C is positioned from the part of the core metal part21on an upper side relative to a center of rotation of the rotation part10and not including the topmost part21a, to the bottommost part21bof the core metal part21. In detail, the third covering part22C is configured so that the angle A1of approx. 50 degrees, as with the second embodiment shown inFIGS.9and10, corresponds to the angle range formed between the first detection part220C and the second detection part230C, with the center of the hole101formed in the rotation part10as the vertex. In the third embodiment, although not illustrated, the angle of approx. 50 degrees is designated as the angle range formed between the first detection part220C and the second detection part230C, with the center of the hole101formed in the rotation part10as the vertex, when the steering device1C is viewed in the negative Y direction. The third covering part22C is thus positioned from a part of the core metal part21on an upper side relative to a center of rotation of the rotation part10and not including the topmost part21a, to the bottommost part21bof the core metal part21. In other words, a first conductive part221C and a second conductive part231C are positioned from a part of the core metal part21on an upper side relative to a center of rotation of the rotation part10and not including the topmost part21a, to the bottommost part21bof the core metal part21.

The first detection part220C shown inFIG.12has a dimension D1between one end part and the other end part thereof, while the first detection part220of the first covering part22shown inFIG.7has a dimension D2between one end part and the other end part thereof, wherein the dimension D1is smaller than the dimension D2. This also applies to the second detection part230C of the third covering part22C.

In the third embodiment, each of the first conductive part221C and the second conductive part231C is less likely to experience variability in detection accuracy depending on differences in the gripped portions, compared to an embodiment in which each of the first conductive part221C and the second conductive part231C is positioned from the topmost part21aof the core metal part21to the bottommost part21b. The detection of the gripping of the steering device1C is performed in order to detect that the occupant of the moving object is in the condition to operate the moving object. In the case where the occupant grips an upper part of the gripping part20relative to the rotation shaft AR in the vertical direction, the occupant may not operate the steering device1C instantly with intended direction or amount. Accordingly, in the case where the topmost part21aof the core metal part21is gripped, there is low necessity to detect the steering device1C as being gripped.

D. Other Embodiments

(1) In the embodiments described above, the steering device1is mounted on the vehicle VW. A steering device may be mounted on a moving object other than a vehicle, for example, a ship or an aircraft.

(2) In the embodiments described above, the core metal part21is configured to be symmetrical with respect to the second symmetrical plane PS2which is the plane including the X axis and the Z axis, in the state where the rotation part10is at the reference angle position. A core metal part may not be configured to be symmetrical with respect to the plane including both the X axis and the Z axis.

(3) In the embodiments described above, the gripping part20has a substantially annular shape. In another embodiment, a gripping part may have a rectangular or trapezoid appearance when viewed in the Y-axis direction. In another embodiment, a gripping part may have a substantially square shape surrounding a rotation part. A gripping part may have the shape in which the gripping part is connected to the left and right parts and the lower part in the vertical direction of a rotation part in the state where the rotation part is at the reference angle position. A gripping part may be two bar-like members arranged on the left and right sides of a rotation part in the state where the rotation part is at the reference angle position. In the case where a gripping part may have a shape not a substantially annular shape, the topmost part of a core metal part may not be positioned on the upper side in the vertical direction with respect to a rotation part, or the bottommost part of the core metal part may not be positioned on the lower side in the vertical direction with respect to the rotation part, in the state where the rotation part is at the reference angle position.

(4) In the embodiments described above, the core metal210is formed of an alloy such as iron, aluminum, or magnesium. In another embodiment, a core metal may be formed solely of iron, aluminum, or magnesium.

(5) In the embodiments described above, the soft covering part211is formed of polyurethane foam. A soft covering part may be formed of a soft material other than polyurethane foam.

(6) In the first embodiment described above, the first covering part22is positioned from the topmost part21aof the core metal part21to the bottommost part21b. In other words, the first covering part22covers the entire core metal part21. A first covering part may be configured to at least partially cover a core metal part. In another embodiment, a first covering part may be positioned from the part of the core metal part above the center of rotation of the rotation part and not including the topmost part, to the part of the core metal part below the center of rotation of the rotation part and not including the bottommost part.

(7) In the embodiments described above, the first conductive part221and the second conductive part231are the coating films formed by coating the first insulting part223and the second insulating part233with a coating material having conductivity, respectively. In another embodiment, a first conductive part and a second conductive part may be sheet-like members having conductivity, respectively.

(8) In the embodiments described above, the first detection part220includes the first shield part222, while the second detection part230includes the second shield part232. The first shield part222and the second shield part232are formed by coating the first insulting part223and the second insulting part233with a coating material containing a material having conductivity, respectively. In another embodiment, a first detection part may not include a first shield part, while a second detection part may not include a second shield part. In another embodiment, a first shield part and a second shield part may be sheet-like members having conductivity.

(9) In another embodiment, a first conductive part and a second conductive part may be configured to cover the outer periphery of a core metal part, not to cover the inner periphery thereof. In many cases, an occupant, when gripping a gripping part, grips a portion closer to the outer periphery of the core metal part, than to the inner periphery. Accordingly, the first conductive part and the second conductive part may be configured to cover the outer periphery of the core metal, not to cover the inner periphery, allowing the surface areas of the first conductive part and the second conductive part to be reduced while still enabling the detection of the gripping by the occupant.

(10) In the embodiments described above, the first front conductive terminal224ais positioned closer to the other end part220bof the first detection part220than to the one end part220a, and the first rear conductive terminal224bis positioned closer to the other end part220bof the first detection part220than to the one end part220a. In another embodiment in which a detector is positioned between the topmost part of a core metal part and a rotation part, a first front conductive terminal and a first rear conductive terminal may be positioned closer to one end part of a first detection part. Similarly, a second front conductive terminal and a second rear conductive terminal may be positioned closer to one end part of a second detection part.

(11) In the first embodiment described above, the first conductive part221and the second conductive part231are positioned from the vicinity of the topmost part21aof the core metal part21to the vicinity of the bottommost part21b. In another embodiment, a first conductive part and a second conductive part may be positioned from the topmost part of a core metal part to the bottommost part so as not to be in contact with each other.

(12)FIG.13shows a cross-sectional view of the steering device1vthat is a variant of the above first embodiment.FIG.13corresponds toFIG.8of the first embodiment. The steering device1vhas a heater part240between the surface of the core metal part21and the first shield part222. Other aspects of the steering device1vare the same as the steering device1of the first embodiment.

The heater part240has, as its main configuration, a flexible sheet-like configuration with an abbreviated rectangular outline. The heater part240can be constructed, for example, by depositing carbon or metal plating on a resin sheet such as PET (polyethylene terephthalate) or polyamide.

The heater part240is arranged on the surface of the core metal part21so that the two long sides of the rectangle face each other at a position on the surface of the core metal part21facing the rotating section10. The heater part240is connected to a power source. The heater part240generates heat by being supplied with electric power from the power source. As a result, the heat is transmitted to the surface of the first conductive part221. Therefore, the occupant can comfortably hold the gripping part20vof the steering device1veven in winter when the temperature is low.

Because the first shield part222is arranged between the heater part240and the first conductive part221, no electrostatic capacitance is generated between the heater part240and the first conductive part221. As a result, the detection of gripping of the gripping part20vusing the first conductive part221is performed stably.

In this variation, the heater part240has a sheet-like configuration having an abbreviated rectangular outline and flexibility. However, the heater part240can also be configured by applying conductive paint to the surface of the first shield part222.

In the above, the configuration and functions of the steering device1vwere described using the side of the steering device1von which the first detection part220is located with respect to the first symmetry plane PS1as an example (see the lower right part ofFIG.3). The steering device1vhas the same configuration for the side where the second detection part230is arranged with respect to the first symmetry plane PS1(see the lower right part ofFIG.3).

(1) In the embodiments described above, the first conductive part221includes the first front conductive part221aand the first rear conductive part221b, while the second conductive part231includes the second front conductive part231aand the second rear conductive part231b. In another embodiment, a first conductive part may be one conductive part positioned from a front-face part to a rear-face part of the surface of a core metal part, while a second conductive part may be one conductive part positioned from a front-face part to a rear-face part of the surface of the core metal part. In another embodiment, a first conductive part may include a first front conductive part and a first rear conductive part, while a second conductive part may be one conductive part positioned from a front-face part to a rear-face part of the surface of a core metal part. In another embodiment, a second conductive part may include a second front conductive part and a second rear conductive part, while a first conductive part may be one conductive part positioned from a front-face part to a rear-face part of the surface of a core metal part.

(2) In the embodiments described above, the harness30includes the first harness310and the second harness320. In another embodiment in which a first conductive part includes a first front conductive part and a first rear conductive part, while a second conductive part is one conductive part positioned from a front-face part to a rear-face part of the surface of a core metal part, one harness may electrically connect the first front conductive part and the second conductive part. In another embodiment in which a second conductive part includes a second front conductive part and a second rear conductive part, while a first conductive part is one conductive part positioned from a front-face part to a rear-face part of the surface of a core metal part, one harness may electrically connect the second front conductive part and the first conductive part. In another embodiment in which each of a first conductive part and a second conductive part is one conductive part positioned from a front-face part to a rear-face part of the surface of a core metal part, one harness may connect the first conductive part and the second conductive part.

(3) In the embodiments described above, the detector40includes the first detector410and the second detector420. In another embodiment in which each of a first conductive part and a second conductive part is one conductive part positioned from a front-face part to a rear-face part of the surface of a core metal part, a detector may detect the gripping condition of a gripping part, on the basis of the change in capacitance generated in at least one of the first conductive part and the second conductive part.

(1) In the third embodiment described above, the core metal part21has an annular shape, and the third covering part22C is positioned from the part of the core metal part21on an upper side relative to a center of rotation of the rotation part10and not including the topmost part21a, to the vicinity of the bottommost part21bof the core metal part21. In another embodiment in which a core metal part has a substantially square shape surrounding a rotation part, a first conductive part and a second conductive part may be positioned from the part of the core metal part on an upper side relative to a center of rotation of the rotation part and not including the topmost part, to the vicinity of the bottommost part of the core metal part, respectively.

(2) In the second and third embodiments described above, the angle of approx. 50 degrees is designated as the angle range A1formed between the first detection part and the second detection part, with the center of the hole101formed in the rotation part10as the vertex, on the plane including the X axis and the Z axis when the steering device1with the rotation part10being at the reference angle position is viewed in the positive Y direction. In another embodiment, the angle of 10 degrees or 90 degrees may be designated as the angle range formed between a first rear conductive part and a second rear conductive part.

(3) In the embodiments described above, the first conductive part221and the second conductive part231have the same length along the outer periphery of the core metal part21. A first conductive part and a second conductive part may have different lengths along the outer periphery of a core metal part. In another embodiment, a first conductive part may have a shorter length along the outer periphery of a core metal part than the length of a second conductive part, along the outer periphery of the core metal part.

(1) In the second embodiment described above, the core metal part21has an annular shape, and the gripping part20includes two light sources arranged on the front-face part21A of the core metal part21, on the upper side in the vertical direction with respect to the rotation part10. In another embodiment in which a core metal part has a substantially square shape surrounding a rotation part, two light sources may be arranged on a rear side in a moving object of a core metal part, on the upper side in the vertical direction with respect to the rotation part.

(2) In the second embodiment described above, the gripping part20includes two light sources arranged on the upper side in the vertical direction with respect to the rotation part10. In another embodiment, a gripping part may include at least one light source arranged on a side other than the upper side in the vertical direction with respect to a rotation part. In the embodiment above, a covering part is arranged on an area other than the light source of a core metal part.

(3) In the second embodiment described above, the angle of approx. 50 degrees is designated as the angle range A1formed between the first detection part and the second detection part, with the center of the hole101formed in the rotation part10as the vertex, on the plane including the X axis and the Z axis. In another embodiment, a first detection part may be arranged in the vicinity of a first light source, while a second detection part may be arranged in the vicinity of a second light source, so as not to cover the first light source or the second light source illustrated inFIG.9.

(4) In the second embodiment described above, the gripping part20includes two light sources of the first light source51and the second light source52. A gripping part may include one or three light sources, not two. A light source may flicker in order to prompt an occupant to grip a gripping part, or may glow when the occupant is not gripping the gripping part.

The present disclosure may be embodied in the following aspects.

(1) In one aspect of the present disclosure, a steering device is provided. The steering device, which is mounted on a moving object, includes a rotation part attached to the moving object so as to be rotatable, and a gripping part connected to the rotation part; the gripping part includes a core metal part configured to be symmetrical across the rotation part, and a covering part configured to at least partially cover the core metal part; the covering part has a first conductive part arranged on one side with respect to a symmetrical plane of the core metal part, formed of a material having conductivity, and a second conductive part arranged on the other side with respect to the symmetrical plane of the core metal part, formed of a material having conductivity; the first conductive part and the second conductive part are arranged independently from each other; the steering device further includes a harness electrically connecting the first conductive part and the second conductive part, and a detector electrically connected to the first conductive part and the second conductive part via the harness, configured to detect gripping condition of the gripping part based on change in capacitance generated in at least one of the first conductive part and the second conductive part.

In the steering device in the aspect above, the first conductive part and the second conductive part are positioned on the sides opposite to each other with respect to the symmetrical plane, and are arranged independently from each other. Each of the conductive parts thus has a smaller area, compared to the aspect where one conductive part covers the entire outer periphery of a core metal part. As a result, each of the first conductive part and the second conductive part is less likely to experience variability in detection accuracy depending on differences in the gripped portions.

(2) In the steering device in the aspect above, the gripping part may be configured to be gripped by an occupant; a surface of the core metal part includes a front-face part on a side facing the occupant, and a rear-face part on a side opposite to the front-face part, the first conductive part may include a first front conductive part arranged in contact with the front-face part, and a first rear conductive part arranged in contact with the rear-face part, while the second conductive part may include a second front conductive part arranged in contact with the front-face part, and a second rear conductive part arranged in contact with the rear-face part; and the harness may include a first harness electrically connecting the first front conductive part and the second front conductive part, and a second harness electrically connecting the first rear conductive part and the second rear conductive part.

(3) In the steering device in the aspect above, the core metal part may have an annular shape; when the rotation part is at a reference angle position, a topmost part that is a highest part in a vertical direction of the core metal part may be positioned on an upper side in the vertical direction with respect to the rotation part, and the covering part may be positioned from a part of the core metal part on an upper side relative to a center of rotation of the rotation part and that does not include the topmost part, to a bottommost part corresponding to a lowest part in the vertical direction of the core metal part. In the steering device in the aspect above, each of the first conductive part and the second conductive part is less likely to experience variability in detection accuracy depending on differences in the gripped portions, compared to the aspect where the first conductive part and the second conductive part are positioned from the topmost part of the core metal part to the bottommost part, respectively.

The detection of the gripping of the steering device is performed in order to detect that the occupant of the moving object is in the condition to operate the moving object. In the case where the occupant grips the topmost part of the gripping part in the vertical direction, the occupant may not operate the steering device instantly with intended direction or amount. Accordingly, in the case where the topmost part of the core metal part is gripped, there is low necessity to detect the steering device as being gripped.

(4) In the steering device in the aspect above, the gripping part may be configured to be gripped by the occupant; the surface of the core metal part may include the front-face part on the side facing the occupant, and the rear-face part on the side opposite to the front-face part; the core metal part may have an annular shape; the gripping part may further include at least one light source positioned on an upper side in a vertical direction with respect to the rotation part when the rotation part is at a reference angle position, on the front-face part of the core metal part, configured to glow according to a situation of the moving object; and the covering part may be arranged on the core metal part other than the position where the light source is arranged.

In the steering device in the aspect above, the gripping part may include the light source and the covering part.

The present disclosure may be embodied in various aspects, for example, a vehicle equipped with the steering device, and a method of producing the steering device.

The present disclosure may be embodied in various configurations without departing from the spirit of the present disclosure, not limited to the above-described embodiments. For example, the technical features in the embodiments corresponding to the technical features in the respective aspects disclosed above may be appropriately replaced or combined in order to solve some or all of the above-described problems, or in order to achieve some or all of the above-described effects. Any of the technical features not described as essential in the present specification may be omitted appropriately.