Steering wheel

Abstract

To provide a steering wheel which suppresses increase in cost and can be simply manufactured even with a configuration having a display device.SOLUTION: A steering wheel has such a configuration that a display device 20 is arranged at a position visible from a driver in a gripping part 2. The gripping part has a core material 12 arranged at its center, as a roughly circle section. The display device includes a substrate 22, a visible light source 23 mounted on the substrate, and a light guide body 25 which diffuses visible light emitted from the visible light source while deflecting the visible light. The substrate is arranged on a lower side away from the driver, around the core material. The light guide body is configured as such an inverted U-shaped section as to surround three sides of the upper side, inside and outside, excluding the lower side where the substrate is arranged, around the core material. The visible light source is arranged on at least one lower end side of the light guide body having the inverted U-shaped section.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a steering wheel having a grip portion that is gripped during rotational steering, and a display device disposed at a predetermined position on the grip portion that is visible to the driver. [Background technology]

[0002] BACKGROUND ART Conventionally, steering wheels having a display device have been configured such that the display device is disposed in an upper region of the grip portion, which is on the driver's side (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special publication 2017-529272 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional steering wheels, the display device is located in approximately the upper half of the grip area. Therefore, in order to ensure the display device placement area, the shape and position of the core material (core metal) that is located in the center of the grip area other than the display device placement area must be significantly redesigned in the display device placement area. This leaves room for improvement in terms of suppressing increases in cost and simplifying manufacturing.

[0005] The present invention is intended to solve the above-mentioned problems, and aims to provide a steering wheel that can be easily manufactured while suppressing increases in costs, even when configured to include a display device. [Means for solving the problem]

[0006] The steering wheel according to the present invention is configured to include a grip portion that is gripped during rotational steering, and a display device is disposed at a predetermined position on the grip portion that is visible to a driver, The gripping portion has a substantially circular cross section and is configured to have a core material disposed in the center, A display device includes a substrate, a visible light source attached to the substrate and emitting visible light when lit, and a light guide that deflects and diffuses the visible light emitted from the visible light source, A substrate is disposed around the core material on a lower side away from the driver, the light guide is configured to have a cross section of a generally inverted U-shape that surrounds three sides of the core material, including an upper side, an inner side that is the side of the rotation steering shaft, and an outer side that is away from the side of the rotation steering shaft, except for a lower side where the substrate is disposed; The visible light source is disposed on at least one lower end side of a light guide having a cross section that is approximately inverted U-shaped.

[0007] In the steering wheel of the present invention, a display device is provided in the grip portion, but the substrate and light guide constituting the display device are arranged to surround a core material located in the center of the grip portion. Therefore, compared to steering wheels not including a display device, the display device can be mounted without significantly changing the shape or position of the core material, eliminating the need for significant design changes to the core material itself and reducing costs. Furthermore, in the steering wheel of the present invention, the light guide that diffuses visible light emitted from the visible light source has a generally inverted U-shaped cross section that surrounds the core material on three sides: the upper side, the inner side toward the rotating steering shaft, and the outer side away from the rotating steering shaft. Therefore, even when the visible light source is provided on at least one lower end of the generally inverted U-shaped cross section of the light guide, the entire light guide can be illuminated during operation, thereby illuminating a wide area around the core material.

[0008] Therefore, even if the steering wheel of the present invention has a configuration including a display device, it can be manufactured easily while suppressing an increase in cost.

[0009] Furthermore, in the steering wheel of the present invention, when the visible light source is disposed only on one lower end of the light guide having a substantially inverted U-shaped cross section, if the light guide is formed with a different thickness so that an upper portion remote from the visible light source is thicker than other inner or outer portions, the amount of diffusion of visible light emitted from the visible light source in this thicker region during operation can be increased, thereby improving the brightness of the region of the light guide remote from the visible light source. As a result, the light guide can be made to glow brightly over a wider range than when the thickness of the light guide is set to be substantially the same throughout, which is preferable.

[0010] Furthermore, in the steering wheel having the above configuration, the display device has a case portion that houses and holds the substrate, and a cover portion that is made of a light-transmitting body and covers the outer periphery of the light guide, and the outer shape of the cross section when the cover portion is attached to the case portion is configured to approximately match the outer shape of the cross section of the general portion of the grip portion adjacent to the display device, The cover portion has an upper wall portion that covers the upper side of the light guide body, and two side wall portions that extend downward from the edge of the upper wall portion and are arranged to cover the sides of the light guide body, It is preferable that the inner surface side of each side wall portion facing the light guide and the outer surface side of the light guide that is positioned opposite the inner surface thereof are each formed with a locking portion that can be locked to each other when the cover portion is placed over the light guide from above.

[0011] In the steering wheel having the above configuration, when the cover that covers the outer periphery of the light guide is placed over the light guide, the light guide can be locked to the cover by the locking portion, so that the light guide and the cover can be handled as a single unit during assembly to the steering wheel (when assembling the display device), which improves assembly workability. Furthermore, since the display device is configured so that its cross-sectional shape is substantially the same as the general cross-sectional shape of the adjacent grip portion, it is possible to reduce the discomfort felt when steering the grip portion.

[0012] Furthermore, in a steering wheel having the above configuration, if a visible light source is arranged on both lower end sides of the light guide, which has a cross section that is approximately inverted U-shaped, it is possible to make the entire light guide shine brightly, compared to when a visible light source is arranged on only one end side of the light guide, which is preferable.

[0013] Furthermore, in the steering wheel of the above configuration, if the visible light source is arranged so that the upper side facing the driver is covered by a light shield that blocks visible light directed toward the driver when the steering wheel is mounted on the vehicle, the visible light emitted from the visible light source is less likely to directly enter the eyes of the driver who is steering the steering wheel. Therefore, the light guide seen by the driver is prevented from shining brightly in certain areas and shines approximately evenly overall, which is preferable as it allows for a good design when lit. [Brief explanation of the drawings]

[0014] [Figure 1] 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 showing a general area of ​​a ring portion in the steering wheel according to the embodiment, and corresponds to the area II-II in FIG. 1. FIG. [Figure 3] FIG. 2 is a partially enlarged plan view showing a display device portion of the steering wheel according to the embodiment. [Figure 4] 4 is a cross-sectional view showing a portion of a display device in the steering wheel of the embodiment, and corresponds to the portion IV-IV in FIG. 3. FIG. [Figure 5] 4 is a cross-sectional view showing a display device portion of the steering wheel of the embodiment, and corresponds to the VV portion of FIG. 3. FIG. [Figure 6] 6 is a partially enlarged cross-sectional view showing the VI-VI portion of FIG. 3 in the display device of the steering wheel according to the embodiment. [Figure 7] FIG. 2 is a schematic perspective view showing a cover portion of the display device. [Figure 8] FIG. 2 is a schematic perspective view showing a light guide in the display device. [Figure 9] 10 is a schematic cross-sectional view showing a state in which a cover portion integrated with a light guide body is attached to a case portion in a steering wheel according to an embodiment. FIG. [Figure 10] 10A and 10B are diagrams illustrating the state of diffusion of visible light by a light guide in the steering wheel of the embodiment. [Figure 11] 4 is a partially enlarged plan view showing a lighting state of a visible light LED in the steering wheel of the embodiment. FIG. [Figure 12] FIG. 10 is a schematic cross-sectional view of a display device in a steering wheel according to another embodiment of the present invention. [Figure 13] FIG. 10 is a schematic cross-sectional view of a display device in a steering wheel according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of the present invention will be described below with reference to the drawings. As shown in Fig. 1, the steering wheel of this embodiment is configured to have an annular ring portion 2 that is gripped when steering, a boss portion 4 located approximately in the center of the ring portion 2, and a plurality of spokes 3 (three in this embodiment) that connect the ring portion 2 and the boss portion 4. In the steering wheel 1 of this embodiment, the ring portion 2 forms the grip portion. The steering wheel 1 is also configured to include, as its components, an airbag device 6 above the boss portion 4, a display device 20 disposed on the ring portion 2, and a steering wheel main body 10.

[0016] In this specification, unless otherwise specified, the front-to-rear, up-down, and left-to-right directions are based on the straight-ahead steering state of the steering wheel 1 when mounted on a vehicle, and the up-down direction is the direction along the rotational axis of the ring portion 2, the front-to-rear direction is the direction perpendicular to the rotational axis of the ring portion 2 and roughly along the front-to-rear direction of the vehicle, and the left-to-right direction is the direction perpendicular to the rotational axis of the ring portion 2 and roughly along the left-to-right direction of the vehicle.

[0017] The airbag device 6, which is disposed above the boss portion 4, includes an airbag (not shown) that is folded and stored, an inflator (not shown) that supplies inflation gas to the airbag, and a pad 7 that covers the upper surface of the folded airbag. As shown in FIG. 1, the pad 7 is disposed so as to cover the entire upper surface of the boss portion 4.

[0018] 1, the steering wheel body 10 includes a core metal 11 as a core material arranged to interconnect the ring portion 2, the boss portion 4, and the spoke portions 3, a coating layer 13 that covers the periphery of the core metal 11 at the location of the ring portion 2 and the spoke portions 3, a skin layer 14 that covers the outer periphery of the coating layer 13, and a lower cover (not shown) that covers the underside of the boss portion 4. The ring portion 2 as a grip portion has a substantially circular cross section (more specifically, a substantially elliptical cross section) and includes a ring portion core metal 12 (described later) as a core material arranged in the center, the coating layer 13 that covers the periphery of the ring portion core metal 12, and the skin layer 14 that covers the outer periphery of the coating layer 13 in a general area 2a other than the area where the display device 20 is arranged (see FIG. 2).

[0019] The core 11 is made of a metal such as an aluminum alloy. In the core 11, a ring portion core 12 disposed at the location of the ring portion 2 has a cross section that is substantially inverted U-shaped (see FIGS. 2 and 4).

[0020] The covering layer 13 is made of a soft synthetic resin with cushioning properties, and in this embodiment, is made of a soft foam material such as foamed polyurethane. As shown in FIGS. 2 and 4, the covering layer 13 is configured to cover the outer periphery of the ring core metal 12 in the ring portion 2, and has a substantially elliptical cross-sectional shape in the general region 2a other than the region where the display device 20 is located (see FIG. 2). Furthermore, in the region where the display device 20 is located, the covering layer 13 is arranged so as to thinly cover the outer periphery of the ring core metal 12 (see FIG. 4). The skin layer 14 is arranged so as to cover the outer periphery of the covering layer 13 except for the region where the display device 20 is located, and in this embodiment, is made of a synthetic resin sheet or leather such as natural leather, synthetic leather, or artificial leather.

[0021] The display device 20 is disposed in a predetermined position on the ring portion 2 (grip portion) of the steering wheel 1 so as to be visible to a driver (not shown). In this embodiment, as shown in FIG. 1, the display device 20 is disposed on the upper surface of the ring portion 2 of the steering wheel 1 in a straight-ahead steering state, in front of the boss portion 4 (specifically, approximately in the center of the front portion of the ring portion 2 between the left and right spoke portions 3L and 3R, i.e., the front end side of the ring portion 2). In this embodiment, the display device 20 is configured to include only one visible light source (a visible light LED 23 (chip-type light-emitting diode: Light Emitting Diode)) as described below, and the width of the display device 20 (light guide 25, cover portion 50, and case portion 40) is set to approximately three times the width of the visible light LED 23 (specifically, approximately 10 mm) (see FIGS. 3 and 5). That is, in the steering wheel 1 of this embodiment, the display device 20 is disposed in only a portion of the area of ​​the ring portion 2 on the front end side when steering straight ahead.

[0022] As shown in FIGS. 3 to 5, the display device 20 includes a substrate 22, a visible light source (visible light LED 23) attached to the substrate 22, a light guide 25, a case 40 that houses and holds the substrate 22, and a cover 50 that covers the outer periphery of the light guide 25. The display device 20 has a substantially elliptical cross-sectional shape when the cover 50 is attached to the case 40, which substantially matches the cross-sectional shape of the general region 2a of the ring 2 adjacent to the display device 20 (see FIGS. 2 and 4). Furthermore, even in the area where the display device 20 is disposed, the ring core 12 is configured to be disposed in the center, and its cross-sectional shape is substantially the same as that of the portion disposed in the general region 2a. Furthermore, in the area where the display device 20 is disposed, the covering layer 13 is thinner than the general region 2a. Specifically, in the area where the display device 20 is disposed, the covering layer 13 is disposed so as to cover three sides from the upper surface side to the lower surface side, excluding the front surface side (the outer surface side in the inward and outward directions) of the ring core metal 12. In the present embodiment, the front surface 12a of the ring core metal 12 is not covered by the covering layer 13 and is exposed (see FIG. 4).

[0023] The substrate 22 is arranged around the ring core metal 12 on the lower side away from the driver, and in the case of the embodiment, is arranged below the ring core metal 12 so as to be substantially aligned with the ring surface 2b of the ring portion 2. The width dimension of the substrate 22 in the cross section of the ring portion is set to be larger than the width dimension of the ring core metal 12, and the substrate 22 is arranged so as to extend forward and backward beyond the ring core metal 12, and in the case of the embodiment, one visible light source (visible light LED 23) is arranged on the upper surface 22b side (surface side) at the front end 22a side (the outer end side in the inward and outward direction).

[0024] A visible light LED 23 is used as a visible light source that emits visible light when illuminated. In this embodiment, the visible light LED 23 is a full-color LED (so-called three-color LED) in which light sources capable of emitting red, green, and blue light are sealed in a single package and the color can be changed by changing the brightness of each light source. As described above, one visible light LED 23 is disposed on the upper surface 22b (front surface) of the front end 22a (outer end in the inward / outward direction) of the substrate 22. More specifically, the visible light LED 23 is attached to the substrate 22 below a lower front end 25a (described later) of the light guide 25 in a region that protrudes forward beyond the ring portion core metal 12 so as to be able to emit visible light VL upward toward the light guide 25 (see FIG. 4). The visible light LED 23 is disposed approximately in the center of the width direction of the substrate 22 (the circumferential direction of the ring portion 2). The visible light LED 23 is electrically connected to an operating circuit (not shown) and is capable of receiving an operating signal from this operating circuit (not shown) and turning on to emit visible light VL of a predetermined color.

[0025] The light guide 25 is disposed around the ring core metal 12 and is configured as a plate with a generally inverted U-shaped cross section that surrounds the ring core metal 12 on three sides, excluding the lower side where the substrate 22 is disposed: the upper side, the inner side facing the steering shaft (boss portion 4), and the outer side away from the boss portion 4 (see FIGS. 4 and 8 ). Specifically, the light guide 25 is configured so that a front portion 26 disposed on the front side (outside in the inward-outward direction) away from the boss portion 4 is in direct contact with the ring core metal 12, and the light guide 25 is disposed around the ring core metal 12 from an upper portion 27 disposed on the upper side to a rear portion 28 disposed on the rear side (inward in the inward-outward direction) facing the boss portion 4, with the coating layer 13 interposed therebetween. As described above, the visible light LED 23 is disposed on the lower end side (front lower end 25 a side) of the front portion 26 of the light guide 25. The light guide 25 receives visible light VL emitted from the visible light LEDs 23 disposed below the front lower end 25a through an incident surface 25c formed by the end face on the front lower end 25a side, deflects the light (refracts and guides the light) internally, and then widely emits the light from the outer peripheral surface 25d (see FIG. 10 ). The light guide 25 is made of a synthetic resin such as polycarbonate resin or acrylic resin. In this embodiment, the light guide 25 is configured such that a boundary between an upper portion 27, which is an upper portion away from the visible light LEDs 23, and a rear portion 28 is thicker than the other inner or outer portions (front portion 26). Specifically, the thick-walled portion 30 is thickest near the boundary between the upper portion 27 and the rear portion 28, and is formed so that the light converges from the front end of the upper portion 27 to the lower end of the rear portion 28 (see FIG. 4 ).

[0026] In the light guide 25, the outer surfaces 26a, 28a of the front portion 26 and the rear portion 28 are planar and extend substantially perpendicular to the substrate 22 (the ring surface 2b) in the up-down direction. The outer surfaces 26a, 28a of the front portion 26 and the rear portion 28 are disposed opposite to inner surfaces 53a, 54a of the front wall portion 53 and the rear wall portion 54 of the cover portion 50, which will be described later, in the inner-outer direction (front-to-back direction). The inner surfaces 35a, 54a are each formed with locking protrusions 26b, 28b. The locking protrusions 26b, 28b have a substantially semicircular cross section and are formed so as to protrude slightly outward (toward the cover portion 50). The locking protrusions 26b, 28b are formed continuously (in a rib shape) across the entire width of the light guide 25 (the circumferential direction of the ring portion 2) (see FIG. 8). The locking projections 26b, 28b, together with locking projections 53b, 54b (described later) on the cover portion 50, constitute locking portions that can be locked together when the cover portion 50 is placed over the light guide 25 from above, and are configured to be arranged in contact with the upper sides of the locking projections 53b, 54b on the cover portion 50 when the light guide 25 is mounted on a vehicle. A protruding portion 32 that can be inserted into a recess 57 formed on the cover portion 50 is formed on the lower end side (rear lower end 25b side) of the rear portion 28 of the light guide 25 (see FIGS. 6 and 8). A recess 33 that can be inserted into a protruding portion 58 formed protruding from the cover portion 50 is formed on the outer peripheral surface 25d near the boundary between the upper portion 27 and the rear portion 28 of the light guide 25 (in the region of the thick portion 30) so as to be partially recessed (see FIGS. 6 and 8). In the embodiment, these protrusions 32 and recesses 33 are formed on one end side of the width direction of the light guide 25 (in the embodiment, the right end 25e side), as shown in Figure 8, and are formed to position the cover portion 50 and the light guide 25, respectively.

[0027] An inner surface 26c of the front portion 26 of the light guide 25 is formed to substantially conform to the front surface 12a of the ring portion core metal 12. As shown in FIGS. 4 and 8 , a protrusion 26d is formed on the inner surface 26c of the front portion 26, protruding toward the ring portion core metal 12. The protrusion 26d has a substantially semicircular cross section and protrudes slightly inward (toward the ring portion core metal 12). The protrusion 26d is formed continuously over the entire width direction side (circumferential direction side of the ring portion 2) of the light guide 25 at two locations: near the lower end of the front portion 26 and at upper and lower intermediate locations. The protrusion 26d is formed to prevent the front portion 26 and the ring portion core metal 12 from coming into contact over a wide area when the light guide 25 is mounted on a vehicle.

[0028] As shown in FIG. 4 , the case 40 that houses and holds the substrate 22 includes an outer wall 41 curved in a generally arcuate shape and covering the substrate 22 from below to the sides (front and rear sides), and a support portion 43 extending upward from the inner circumferential surface of the outer wall 41 to support the substrate. The outer wall 41 is curved such that its outer surface 41a is generally aligned with the outer surface (skin layer 14) of the general region 2a of the ring portion 2. At both ends of the outer wall 41 (the front upper end 41b and the rear upper end 41c), there are formed substantially rectangular locking holes 42, 42 into which locking claws 56, 56 of the cover 50, which will be described later, can be inserted and locked. The case 40 is made of a black synthetic resin to match the skin layer 14. In this embodiment, the case 40 is made of a soft synthetic resin such as a polyolefin-based thermoplastic elastomer (TPO).

[0029] The cover 50, which covers the outer periphery of the light guide 25, includes an upper wall 51 that covers the upper side of the light guide 25, and two side walls (a front wall 53 and a rear wall 54) that extend downward from the edge of the upper wall 51 and are arranged to cover the sides of the light guide 25. The cover 50 is made of a translucent synthetic resin that is capable of transmitting visible light emitted from the visible light LEDs 23. Specifically, the cover 50 is made of a translucent black transparent polycarbonate resin, acrylic resin, or the like. The upper wall 51 is curved so as to substantially fit along the upper portion 27 of the light guide 25. The front wall portion 53 and the rear wall portion 54 extend downward from the edge of the upper wall portion 51 and are arranged so as to face the front portion 26 and the rear portion 28 of the light guide 25, respectively, in the front and rear directions. The inner surfaces 53a and 54a facing the light guide 25 are flat and extend approximately in the vertical direction, along the outer surfaces 26a and 28a of the front portion 26 and the rear portion 28 of the light guide 25 that are arranged opposite to them.

[0030] Locking claws 56, 56 for attaching the cover 50 to the case 40 are formed on the lower ends 53c, 54c of the front wall 53 and the rear wall 54. Each locking claw 56 is formed at the center of the width of the cover 50 so as to protrude outward from the front wall 53 and the rear wall 54 (see FIG. 7), and has a cross-sectional shape that is a substantially right-angled triangle with its hypotenuse positioned downward. When attaching the cover 50 to the case 40 by moving the cover 50 from above toward the case 40 (see FIG. 9), these locking claws 56 are inserted into the locking holes 42 formed in the outer wall 41, using the inclined surfaces 56a as guides, so as to bend the front upper end 41b and the rear upper end 41c of the outer wall 41 of the case 40, and the upper surfaces 56b are locked to the peripheries of the locking holes 42. As described above, a recess 57 is formed on the lower end 54c of the rear wall 54, into which the protrusion 32 formed on the light guide 25 can be inserted. In this embodiment, the recess 57 is formed on the right end of the rear wall 54, offset in the width direction from the locking claw 56, so as to penetrate the rear wall 54 (see FIGS. 4 and 7). Furthermore, on the inner surface 51a of the upper wall 51, a protrusion 58 is formed so as to partially protrude, so as to be insertable into the recess 33 formed on the light guide 25, as described above. This protrusion 58 is also formed on the right end of the upper wall 51.

[0031] Furthermore, locking protrusions 53b, 54b are formed on inner surfaces 53a, 54a of the front wall portion 53 and the rear wall portion 54 of the cover portion 50. These locking protrusions 53b, 54b have a generally semicircular cross section that is substantially the same in outer shape as the locking protrusions 26b, 28b formed on the light guide 25 side, and are formed so as to protrude slightly inward (toward the light guide 25), and are formed continuously over the entire width direction side of the cover portion 50 (around the circumferential direction of the ring portion 2) like the locking protrusions 26b, 28b on the light guide 25 side (see FIG. 7). The locking projections 53b, 54b, together with the locking projections 26b, 28b on the light guide 25, constitute a locking portion that can be locked together when the cover portion 50 is placed over the light guide 25 from above, and are configured to be arranged in contact with the undersides of the locking projections 26b, 28b on the light guide 25 when mounted on a vehicle. The locking projections 26b, 28b, 53b, 54b that constitute the locking portion are set to have a protrusion amount that can be easily overcome when the cover portion 50 is placed over the light guide 25 from above and moved downward, and that can maintain a mutual locked state (preventing the light guide 25 from coming off the cover portion 50 after being locked).

[0032] A protrusion 51b protruding toward the light guide 25 is formed on the inner surface 51a of the upper wall 51 of the cover 50. As shown in FIGS. 4 and 7 , the protrusion 51b has a generally semicircular cross section and is formed to protrude slightly inward (toward the light guide 25), and is formed continuously over the entire width direction side of the cover 50 (the circumferential direction side of the ring portion 2) (see FIG. 3 ). The protrusion 51b is formed to prevent contact over a wide area between the upper portion 27 of the light guide 25 and the upper wall 51 of the cover 50 when the cover 50 is mounted on a vehicle. In this embodiment, the cover 50 is configured to closely cover the outer periphery of the light guide 25 with a small gap formed therebetween. In addition, the cover portion 50 is configured so that its outer surface 50a smoothly continues from the outer surface 41a of the outer wall portion 41 of the case portion 40 when attached to the case portion 40, and is curved so as to roughly follow the outer surface (skin layer 14) of the general region 2a of the ring portion 2 (see Figures 2, 4, and 5).

[0033] In the steering wheel 1 of this embodiment, the display device 20 is attached to the ring portion 2 as follows. First, the light guide 25 and the cover portion 50 are integrated by engaging the locking protrusions 26b, 28b, 53b, and 54b with each other. The substrate 22 is also attached to the case portion 40. Then, as shown in FIG. 9 , the cover portion 50 holding the light guide 25 is placed over the ring core metal 12, and the cover portion 50 is attached to the case portion 40, which is disposed below the ring core metal 12, using the locking claws 56 and the locking holes 42, with the ring core metal 12 sandwiched therebetween. This completes the attachment of the display device 20 to the ring portion 2. In the steering wheel 1 of this embodiment, the visible light LED 23 is configured to be illuminated, for example, when an activation signal is input from an activation circuit (not shown) to alert the driver. When this visible light LED 23 is turned on, as shown in Figure 10, visible light VL is deflected and diffused within the light guide 25, causing the entire light guide 25 to light up, and when the steering wheel 1 is viewed from above, the entire display device 20 appears to light up, as shown in Figure 11 (the lighted state is shown shaded).

[0034] In the steering wheel 1 of the embodiment, the display device 20 is disposed in the ring portion 2 serving as the grip portion, but the substrate 22 and light guide 25 constituting the display device 20 are disposed so as to surround the periphery of the ring portion core metal 12 (core material) disposed in the center of the ring portion 2. Therefore, compared to a steering wheel not provided with a display device, the display device 20 can be mounted without significantly changing the shape or position of the ring portion core metal 12 (core material), which eliminates the need for a major design change to the core metal 11 itself and suppresses increases in costs. Furthermore, in the steering wheel 1 of the embodiment, the light guide 25 that diffuses the visible light VL emitted from the visible light LED 23 has a cross-sectional shape that is approximately inverted U-shaped, surrounding the ring core metal 12 on three sides: the upper side, the inner side toward the boss portion 4, and the outer side away from the boss portion 4.Therefore, even if the visible light LED 23 is arranged on one lower end side of the light guide 25 that has a cross-sectional shape that is approximately inverted U-shaped (in the embodiment, the front lower end 25a side), when activated, the entire light guide 25 is illuminated, thereby making it possible to illuminate a wide area around the ring core metal 12.

[0035] Therefore, even if the steering wheel 1 of the embodiment has a configuration including the display device 20, an increase in cost can be suppressed and the steering wheel 1 can be easily manufactured.

[0036] Furthermore, in the steering wheel 1 of the embodiment, the visible light LEDs 23 are disposed only on one lower end side (front lower end 25a side) of the light guide 25, and the light guide 25 is formed with a different thickness such that an upper portion distant from the visible light LEDs 23 (more specifically, near the boundary between the upper portion 37 and the rear portion 28) is thicker than other inner or outer portions (front portion 36). Therefore, by providing such thick portion 30 in the light guide 25, the amount of diffusion of visible light VL emitted from the visible light LEDs in the region of the thick portion 30 in the light guide 25 during operation can be increased, thereby improving the brightness of the region of the light guide 25 distant from the visible light LEDs 23. As a result, compared to a case where the thickness of the light guide is set to be substantially uniform throughout, even when the visible light LEDs 23 are disposed only on one end side, the light guide 25 can be made to shine brightly over a wide range. If such a point is not taken into consideration, even in a configuration in which the visible light source is disposed only on one end side, the thickness of the light guide 25 may be set to be substantially uniform over the entire area.

[0037] Furthermore, in the steering wheel 1 of the embodiment, the light guide 25 and the cover portion 50 covering the outer periphery of the light guide 25 are configured to have locking portions (locking protrusions 26b, 28b, 53b, and 54b). When the cover portion 50 is placed over the light guide 25, the locking protrusions 26b, 28b, 53b, and 54b allow the light guide 25 to be locked to the cover portion 50. This allows the light guide 25 and the cover portion 50 to be handled as a single unit during assembly to the steering wheel body 10 (when assembling the display device 20), improving assembly workability. Furthermore, in the steering wheel 1 of the embodiment, the display device 20 is configured to have a cross-sectional shape that is substantially the same as the general region 2a of the adjacent ring portion 2, thereby reducing the sense of discomfort felt when steering the ring portion 2. If this point is not taken into consideration, the light guide 25 and the cover portion 50 may not be provided with locking portions. In the embodiment, the locking projections 26b, 28b, 53b, and 54b serving as locking portions are formed so as to protrude from both the light guide 25 side and the cover portion 50 side, and are arranged over substantially the entire width of the light guide 25 and the cover portion 50. This prevents the cover portion 50 and the light guide 25 from coming into contact over a wide area, and the state in which the light guide 25 is attached to the cover portion 50 can be stably maintained without increasing the amount of protrusion. If these points are not taken into consideration, the shape of the locking portions is not limited to that in the embodiment. For example, a configuration may be adopted in which a protruding body formed on one side is inserted into a recessed portion formed on the other side to be locked.

[0038] In the steering wheel 1 of the embodiment, the cover portion 50 with the integrated light guide 25 is also connected to the case portion 40 by being placed over the case portion 40 from above. That is, in the steering wheel 1 of the embodiment, the engagement direction when the cover portion 50 and the light guide 25 are engaged with each other is the same as the attachment direction of the cover portion 50 with the integrated light guide 25 to the case portion 40, which further improves the workability during assembly.

[0039] In the steering wheel 1 of the embodiment, the visible light LEDs 23 are disposed only on the front lower end 25a side of the light guide 25, but as in the display device 20A of the steering wheel 1A shown in Fig. 12, the visible light LEDs 23A, 23A may be disposed on both lower end sides (both the front lower end 25a side and the rear lower end 25b side) of the light guide 25A having a generally inverted U-shaped cross section. With the steering wheel 1A configured in this way, the light guide 25A can be made to glow brightly over its entirety, compared to the steering wheel 1 described above in which the visible light LEDs 23 are disposed only on one end side of the light guide 25.

[0040] Furthermore, the display device 20B in the steering wheel 1B may be configured as shown in Fig. 13. In the display device 20B shown in Fig. 13, similar to the display device 20 in the steering wheel 1 described above, a substrate 22B having visible light LEDs 23B arranged on an upper surface 22b at a front end 22a side is attached to the case portion 40B so as to be inclined downward toward the front with respect to the ring surface 2b, and the visible light LEDs 23B are attached to the substrate 22B at a position so as not to protrude forward beyond the covering layer 13B that covers the periphery of the ring portion core metal 12. In other words, the visible light LEDs 23B are arranged so that the upper side, which is on the driver's side, is covered by the covering layer 13B, which is a light shield that blocks visible light VL directed toward the driver's side. Furthermore, the portion of covering layer 13B covering the front side of ring core metal 12 is configured to narrow toward the lower end side on the visible light LED 23B side, and light guide 25B is configured to widen toward the front lower end 25a side on the visible light LED 23B side, covering the upper side of visible light LED 23B, and allowing visible light VL emitted from visible light LED 23B to enter through incident surface 25c consisting of the end face on the front lower end side. With steering wheel 1B configured in this way, visible light VL emitted from visible light LED 23B is less likely to enter the eyes of the driver steering steering wheel 1B, and light guide 25B reflected in the driver's eyes is prevented from shining brightly in certain areas, and instead shines approximately evenly overall, improving the design when lit. In the embodiment, the covering layer 13B is configured to act as a light shield and cover the visible light LED from above, but the visible light LED may also be arranged on the back side (lower side) of the substrate, with the substrate acting as the light shield.

[0041] In the steering wheel 1 of the embodiment, the visible light LEDs 23 are arranged only on the front lower end 25a side of the light guide 25 (the lower end side on the outer side in the inward / outward direction of the ring portion 2), but the visible light LEDs may be arranged only on the opposite end side of the light guide 25, i.e., only on the lower end side on the inner side in the inward / outward direction of the ring portion 2. In addition, in the embodiment, the display device 20 is arranged on the front end side of the ring portion 2 when steering straight ahead, but the arrangement position of the display device 20 is not limited to the embodiment, and for example, the display device 20 may be arranged on the rear end side of the ring portion 2 when steering straight ahead. Furthermore, in the embodiment, the display device 20 is arranged with only one visible light LED, but the display device 20 may be configured to have a plurality of visible light LEDs arranged along the circumferential direction of the ring portion and to be elongated along the circumferential direction of the ring portion.

[0042] Although the steering wheel 1 of the embodiment is configured to have a circular ring portion 2, the steering wheels to which the present invention can be applied are not limited to those configured to have a circular ring portion. For example, the present invention can also be applied to steering wheels that have a square ring portion or a type that has a rod-shaped grip portion that partially protrudes from the boss portion 4 instead of the ring portion 2. [Explanation of symbols]

[0043] 1,1A,1B...Steering wheel, 2...Ring part (gripping part), 2a...General area (general part), 12...Ring part core metal (core material), 13B...Coating layer (light shielding body) , 20,20A,20B...Display device, 22,22B...Substrate, 23,23A,23B...Visible light LED (visible light source), 25,25A,25B...Light guide, 25a ...front lower end, 25b...rear lower end, 25d...outer circumferential surface, 26a, 28a...outer surface, 26b, 28b...locking protrusion (locking part), 30...thick part, 40,40B...case part , 50...cover part, 51...top wall part, 53...front wall part (side wall part), 54...rear wall part (side wall part), 53a, 54a...inner surface, 53b, 54b...locking protrusion (locking part).

Claims

1. A steering wheel having a gripping portion to be gripped during rotational steering, and a display device disposed at a predetermined position on the gripping portion that is visible to a driver, The gripping portion has a substantially circular cross section and is configured to have a core material disposed at the center, the display device comprises a substrate, a visible light source attached to the substrate and emitting visible light when lit, and a light guide that deflects and diffuses the visible light emitted from the visible light source, The substrate is disposed around the core material on a lower side away from the driver, the light guide is configured to have a cross section of a generally inverted U-shape surrounding the core material on three sides, including an upper side, an inner side that is a rotation steering shaft side, and an outer side that is away from the rotation steering shaft side, except for a lower side where the substrate is disposed, A steering wheel characterized in that the visible light source is disposed on at least one lower end side of the light guide having a substantially inverted U-shaped cross section.

2. The visible light source is configured to be disposed only on one lower end side of the light guide having a substantially inverted U-shaped cross section, 2. The steering wheel according to claim 1, wherein the light guide is formed with a different thickness dimension so that an upper portion thereof, which is distant from the visible light source, is thicker than other inner or outer portions thereof.

3. the display device has a case portion that houses and holds the substrate, and a cover portion that is formed from a light-transmitting body and covers an outer periphery of the light guide, and the outer shape of a cross section of the cover portion when attached to the case portion is configured to substantially match the outer shape of a cross section of a general portion of the grip portion adjacent to the display device, The cover portion has an upper wall portion that covers the upper side of the light guide, and two side wall portions that extend downward from the edge of the upper wall portion and are arranged to cover the sides of the light guide, A steering wheel as described in claim 1 or 2, characterized in that a locking portion is formed on the inner surface side of each side wall portion that faces the light guide and on the outer surface side of the light guide that is positioned opposite the inner surface, so that the locking portion can be locked to each other when the cover portion is placed over the light guide from above.

4. 4. The steering wheel according to claim 1, wherein the visible light sources are disposed on both lower end sides of the light guide having a substantially inverted U-shaped cross section.

5. 5. The steering wheel according to claim 1, wherein the visible light source is arranged such that, when mounted on a vehicle, an upper side thereof facing the driver is covered by a light blocking body that blocks visible light directed toward the driver.

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