Steering cover

Abstract

In this steering, a cover body is attached to the rim part, and detection electrodes of the cover body are provided on the left side and the right side of the steering. The detection electrodes are composed of a cloth layer and a rubber layer. Thus, when the cover body is attached to the rim part, the cloth layer and the rubber layer of the detection electrodes can be extended, and the cover body can be easily attached to the rim part.

Description

Steering cover

[0001] The present invention relates to a steering cover provided with a pair of detection electrodes for detecting an electrocardiogram waveform of a passenger in contact with the steering cover.

[0002] In the biological information detection device described in JP 2009-45077 A, a steering wheel cover is attached to an operating steering wheel. Furthermore, the steering wheel cover is provided with a pair of contact layers, and the driver comes into contact with the pair of contact layers to detect the driver's electrocardiogram information.

[0003] In this biological information detecting device, the contact layer is made of an epoxy resin containing a conductive filler.

[0004] SUMMARY OF THE INVENTION In consideration of the above, an object of the present invention is to provide a steering cover that allows a cover body to be easily attached to a steering wheel.

[0005] A first aspect of the steering cover of the present invention comprises a cover body attached to a steering wheel operated by a vehicle occupant to steer the vehicle and covering the steering wheel, a pair of detection electrodes provided on the cover body and constituted by at least one of a cloth layer and a rubber layer, and a detection unit connected to the pair of detection electrodes and detecting the electrocardiogram waveform of the occupant in contact with the pair of detection electrodes.

[0006] A steering cover according to a second aspect of the present invention is the steering cover according to the first aspect of the present invention, wherein the detection electrodes are arranged on the front side and outer circumferential side of the steering wheel.

[0007] A steering cover of a third aspect of the present invention is a steering cover of the first or second aspect of the present invention, which includes a DRL electrode that is provided on the cover body along the detection electrodes, comes into contact with an occupant, and in-phase signal noise that enters the pair of detection electrodes via the occupant is inverted and fed back to the occupant.

[0008] A steering cover of a fourth aspect of the present invention is the steering cover of any one of the first to third aspects of the present invention, wherein the threads constituting the fabric layer are inclined with respect to the circumferential direction of the steering wheel.

[0009] A steering cover of a fifth aspect of the present invention is the steering cover of any one of the first to fourth aspects of the present invention, wherein the detection electrodes are provided on the cover body in an overlapping state.

[0010] In a steering cover according to a first aspect of the present invention, a vehicle is steered by an occupant operating the steering wheel. A cover body is attached to the steering wheel to cover the steering wheel. A pair of detection electrodes is provided on the cover body, and a detection unit is connected to the pair of detection electrodes, and the detection unit detects an electrocardiogram waveform of the occupant who is in contact with the pair of detection electrodes.

[0011] Here, the detection electrode is made of at least one of a fabric layer and a rubber layer, so that when the cover body is attached to the steering wheel, the detection electrode can expand and contract, making it easy to attach the cover body to the steering wheel.

[0012] In the steering cover of the second aspect of the present invention, the detection electrodes are disposed on the front and outer periphery of the steering wheel, so that the occupant can touch the detection electrodes with the palm of their hand, allowing the occupant to properly contact the detection electrodes.

[0013] In the steering cover of the third aspect of the present invention, a DRL electrode is provided on the cover body along the detection electrodes, and when an occupant comes into contact with the DRL electrode, common-mode signal noise that has entered the pair of detection electrodes via the occupant is inverted and fed back to the occupant from the DRL electrode, thereby reducing the common-mode signal noise that enters the pair of detection electrodes via the occupant.

[0014] In the steering cover of the fourth aspect of the present invention, the threads constituting the fabric layer are inclined with respect to the circumferential direction of the steering wheel, so that the detection electrode (fabric layer) can easily expand and contract in the circumferential and radial directions of the steering wheel.

[0015] In the steering cover of the fifth aspect of the present invention, the detection electrodes are provided on the cover body in an overlapping state, which allows the detection electrodes to protrude from the cover body by a large amount, thereby enabling an occupant to properly contact the detection electrodes.

[0016] 2A . FIG. 2B is a front view, as seen from the front side, of a steering wheel to which a steering cover according to a first embodiment of the present invention is applied. FIG. 2C is a front view, as seen from the front side, of a cover body of the steering cover according to the first embodiment of the present invention. FIG. 2B is a cross-sectional view taken along line 2B-2B of FIG. 2A . FIG. 2C is a development view, as seen from the front side, of the cover body of the steering cover according to the first embodiment of the present invention. FIG. 2D is a perspective view showing the cover body of the steering cover according to the first embodiment of the present invention before it is attached to the steering. FIG. 2E is a perspective view showing the rim portion of the steering wheel and the cover body in the first embodiment of the present invention. FIG. 2F is a cross-sectional view showing a first step of a process of joining the covering material and the detection electrodes in the steering cover according to the first embodiment of the present invention. FIG. 2G is a cross-sectional view showing a second step of a process of joining the covering material and the detection electrodes in the steering cover according to the first embodiment of the present invention. FIG. 2H is a plan view showing the fabric layer of the detection electrodes in the steering cover according to the first embodiment of the present invention before they are attached to the steering. FIG. 2H is a plan view showing the fabric layer of the detection electrodes in the steering cover according to the first embodiment of the present invention after they have been attached to the steering. FIG. 2I is a front view, as seen from the front side, of a steering wheel to which a steering cover according to a second embodiment of the present invention is applied. FIG. 2I is a development view, as seen from the front side, of a cover body of a steering cover according to a third embodiment of the present invention.

[0017] 1 shows a front view of a steering wheel 12 to which a steering cover 10 according to a first embodiment of the present invention is applied. In the drawing, the front of the steering wheel 12 is indicated by an arrow FR, the upper side of the steering wheel 12 is indicated by an arrow UP, the right side of the steering wheel 12 is indicated by an arrow RH, and the circumferential direction of the steering wheel 12 is indicated by an arrow C.

[0018] In this embodiment, the steering wheel 12 faces the front of the driver's seat of the vehicle, and is disposed in front of the occupant (driver) seated in the driver's seat. The front, upper, and right sides of the steering wheel 12 are directed obliquely upward and rearward, obliquely upward and frontward, and rightward, respectively, of the vehicle.

[0019] 1, the central portion of the steering wheel 12 is a boss portion 12A, and the peripheral portion of the steering wheel 12 is a rim portion 12B (see FIG. 3C) that is annular in front view and has a circular cross section and serves as a gripping portion and a mounting portion. Four spoke portions 12C are provided between the boss portion 12A and the rim portion 12B as connecting portions, and the spoke portions 12C extend from the boss portion 12A to the left, right, diagonally downward to the left, and diagonally downward to the right, and are connected to the rim portion 12B.

[0020] The boss portion 12A is fixed to the rear end (upper end) of a cylindrical steering shaft 14 serving as a support member for the vehicle, and the steering shaft 14 is disposed coaxially with the rim portion 12B. The steering wheel 12 is supported by the steering shaft 14 so as to be rotatable integrally with it, and when an occupant grips the rim portion 12B and rotates the steering wheel 12 in the circumferential direction, the steering shaft 14 rotates about the central axis, thereby steering the vehicle.

[0021] A cover portion 16 is provided on the front portions of the boss portion 12A and the two upper spoke portions 12C, and the cover portion 16 covers the front side of the rear portions of the boss portion 12A and each spoke portion 12C, and a space is provided between the boss portion 12A and the rear portions of each spoke portion 12C. The periphery of the rim portion 12B is formed by a rim base material 18 (see Figure 3C), which is made of rubber.

[0022] The steering cover 10 according to this embodiment is provided with an annular, plate-shaped cover body 20 (see FIGS. 2A and 2B), and the cover body 20 is attached to the rim portion 12B of the steering wheel 12 as an after-market attachment.

[0023] The cover body 20 is provided with an annular, plate-shaped cover base material 22, which is made of rubber.

[0024] The front side of the cover substrate 22 is covered with an annular, strip-shaped covering material 24, which is made of leather (or cloth) and serves as an insulator. The covering material 24 is composed of multiple (four in this embodiment) rectangular pieces 24A (see FIGS. 3A and 3B ), which are connected to each other in an annular shape by sewing. Both widthwise ends of the covering material 24 are bent at both ends of the cover substrate 22 into a U-shaped cross section and connected to both ends of the cover substrate 22 by sewing, thereby fixing the covering material 24 to the cover substrate 22. Elongated rectangular fixing holes 26 (see FIG. 4B ) are formed through the pieces 24A of the covering material 24 on the left and right sides of the steering wheel 12, and the fixing holes 26 extend circumferentially around the steering wheel 12 on the front and outer periphery of the rim portion 12B.

[0025] A long, rectangular detection electrode 28 (see FIG. 4B ) is provided in the covering material 24 (piece 24A) at the position of the fixing hole 26. The detection electrode 28 extends in the circumferential direction of the steering wheel 12, in front of and on the outer periphery of the rim portion 12B. The front side of the detection electrode 28 is a rubber layer 28A made of rubber, and the back side of the detection electrode 28 is a cloth (woven) fabric layer 28B. The rubber layer 28A and the fabric layer 28B are electrically conductive and bonded to each other. The warp and weft threads of the fabric layer 28B are perpendicular to each other, and are inclined at a predetermined angle (45° in this embodiment) with respect to the circumferential direction of the cover body 20 (the circumferential direction of the steering wheel 12) (see FIG. 5A ). Both widthwise ends of the detection electrode 28 are folded back and joined by sewing to both widthwise outer sides of the fixing hole 26 of the covering material 24, whereby the detection electrode 28 is fixed to the covering material 24 and covers the front side of the fixing hole 26. Note that by joining the detection electrode 28 to the covering material 24 by sewing before folding back the detection electrode 28 to the covering material 24 (see FIG. 4A ), the joining operation of the detection electrode 28 to the covering material 24 can be facilitated.

[0026] When the cover body 20 is attached to the rim portion 12B of the steering wheel 12, the cover body 20 is stretched in the circumferential direction of the steering wheel 12 and fitted to the outer periphery of the rim portion 12B in the circumferential direction of the steering wheel 12 (see FIG. 3C). The cover body 20 is then deformed into a C-shape in the width direction (see FIG. 2B) and fitted to the rim portion 12B in the circumferential direction of the rim portion 12B (direction around the circumferential direction of the steering wheel 12). Therefore, on the outer circumferential side of the rim portion 12B, the cover body 20 is stretched in the circumferential direction of the steering wheel 12, and on the inner circumferential side of the rim portion 12B, the cover body 20 is contracted in the circumferential direction of the steering wheel 12.

[0027] The left and right detection electrodes 28 of the steering wheel 12 are each connected to an ECU 32, which serves as a detection unit, via a detection cord 30. The ECU 32 is fixed inside the boss portion 12A of the steering wheel 12, and the detection cord 30 is connected from the detection electrodes 28 to the ECU 32 through the inside of the cover body 20 and inside the spoke portion 12C on the upper side of the steering wheel 12. The ECU 32 is connected to a vehicle power source (not shown) via a power cord 34, and receives power from the power source via the power cord 34.

[0028] Next, the operation of this embodiment will be described.

[0029] In the steering wheel 12 configured as described above, the cover body 20 is attached to the rim portion 12B, and the detection electrodes 28 of the cover body 20 are provided on the left and right sides of the steering wheel 12.

[0030] When the occupant's hands grip the rim portion 12B (including the cover body 20), the left hand usually contacts the left detection electrode 28 of the steering wheel 12, and the right hand usually contacts the right detection electrode 28 of the steering wheel 12. The ECU 32 then detects the differential voltage between the left and right detection electrodes 28 of the steering wheel 12 to detect the occupant's electrocardiogram waveform.

[0031] Here, the detection electrode 28 is made up of a fabric layer 28B and a rubber layer 28A. Therefore, when the cover body 20 is attached to the rim portion 12B, even if the detection electrode 28 is disposed on the outer periphery of the rim portion 12B and stretched in the circumferential direction of the steering wheel 12, the fabric layer 28B and the rubber layer 28A of the detection electrode 28 can stretch, making it easy to attach the cover body 20 to the rim portion 12B. Furthermore, stretching the detection electrode 28 can prevent wrinkles from occurring in the cover body 20.

[0032] Furthermore, the warp and weft threads constituting the fabric layer 28B of the detection electrode 28 are inclined with respect to the circumferential direction of the steering wheel 12. Therefore, when the cover body 20 is attached to the rim portion 12B, the inclination angle of the warp and weft threads of the fabric layer 28B with respect to the circumferential direction of the steering wheel 12 is reduced (see FIG. 5B ), which allows the detection electrode 28 (fabric layer 28B) to easily stretch in the circumferential direction of the steering wheel 12.

[0033] Furthermore, the detection electrodes 28 are disposed on the front and outer periphery of the rim portion 12B. Therefore, when the occupant grips the rim portion 12B, the occupant can contact the detection electrodes 28 with their palms, allowing the occupant to properly contact the detection electrodes 28. As a result, the occupant can rest their arm weight on the rim portion 12B, allowing the occupant's palms to stably contact the detection electrodes 28 even during vibrations caused by the vehicle traveling, thereby preventing noise caused by vehicle vibrations from intruding into the occupant's electrocardiogram waveform detected by the ECU 32.

[0034] Furthermore, in the cover body 20, both widthwise ends of the detection electrode 28 are folded back and joined to the covering material 24 in an overlapping state. This allows the detection electrode 28 to protrude more from the covering material 24, and allows the occupant's hand to more appropriately contact the detection electrode 28 when gripping the rim portion 12B.

[0035] Second Embodiment FIG. 6 shows a front view of a steering wheel 12 to which a steering cover 50 according to a second embodiment of the present invention is applied.

[0036] The steering cover 50 according to this embodiment has a configuration substantially similar to that of the first embodiment, but differs in the following respects.

[0037] 6 , in this embodiment, a substantially rectangular box-shaped bracket 52 is fixed as a fixing part to the lower end of the rim portion 12B of the steering wheel 12, and the bracket 52 protrudes upward (toward the radial inside of the steering wheel 12) from the rim portion 12B. The ECU 32 is fixed within the bracket 52, and the detection cord 30 is connected to the ECU 32 from the detection electrode 28 of the cover body 20 through the inside of the cover body 20. A battery 54 is fixed within the bracket 52, and the ECU 32 is connected to the battery 54 via a power cord 34 and receives power from the battery 54 via the power cord 34.

[0038] Here, this embodiment can also achieve the same functions and effects as the first embodiment.

[0039] Third Embodiment FIG. 7 shows a development view of the cover body 20 of a steering cover 60 according to a third embodiment of the present invention, as viewed from the front side.

[0040] The steering cover 60 according to this embodiment has a configuration substantially similar to that of the first embodiment, but differs in the following respects.

[0041] As shown in Figure 7, in the steering cover 60 according to this embodiment, an elongated rectangular additional hole 62 (see Figure 4B) is formed through the covering material 24 (piece 24A) of the cover body 20 on the rear side of the fixing hole 26, and the additional hole 62 extends in the circumferential direction of the steering wheel 12 on the outer periphery side of the rim portion 12B.

[0042] A long, rectangular DRL electrode 64 (Driven Right Leg electrode) is provided in the covering material 24 (piece 24A) at the position of the additional hole 62. The DRL electrode 64 extends in the circumferential direction of the steering wheel 12, rearward of the detection electrode 28 and on the outer circumferential side of the rim portion 12B. The DRL electrode 64 has a configuration similar to the detection electrode 28 and includes a rubber layer 28A and a fabric layer 28B (see FIGS. 4B and 5A ). Both widthwise ends of the DRL electrode 64 are folded back and joined to both widthwise outer sides of the additional hole 62 in the covering material 24 by sewing, thereby fixing the DRL electrode 64 to the covering material 24 and covering the front side of the additional hole 62.

[0043] The left and right DRL electrodes 64 of the steering wheel 12 are each connected to the ECU 32 via a DRL cord (not shown) in a mutually conductive state, and the DRL cord is connected from the DRL electrodes 64 to the ECU 32 via a path similar to that of the detection cord 30.

[0044] Here, this embodiment can also achieve the same functions and effects as the first embodiment.

[0045] Furthermore, a DRL electrode 64 is provided on the cover body 20 along the detection electrodes 28. Therefore, when the occupant's hands grip the rim portion 12B (including the cover body 20) of the steering wheel 12, the occupant's left hand typically contacts the detection electrode 28 and DRL electrode 64 on the left side of the steering wheel 12, and the occupant's right hand typically contacts the detection electrode 28 and DRL electrode 64 on the right side of the steering wheel 12. Common-mode signal noise that enters the pair of detection electrodes 28 via the occupant is inverted and amplified in the ECU 32 and fed back to the occupant via the pair of DRL electrodes 64. This reduces the common-mode signal noise that enters the pair of detection electrodes 28 via the occupant.

[0046] Furthermore, the DRL electrode 64 is made up of the fabric layer 28B and the rubber layer 28A. Therefore, even if the DRL electrode 64 is positioned on the outer periphery of the rim portion 12B and stretched in the circumferential direction of the steering wheel 12 when the cover body 20 is attached to the rim portion 12B, the fabric layer 28B and the rubber layer 28A of the DRL electrode 64 can stretch, making it easy to attach the cover body 20 to the rim portion 12B. Furthermore, stretching the DRL electrode 64 helps prevent wrinkles from forming in the cover body 20.

[0047] Furthermore, the warp and weft threads constituting the fabric layer 28B of the DRL electrode 64 are inclined relative to the circumferential direction of the steering wheel 12. Therefore, when the cover body 20 is attached to the rim portion 12B, the inclination angle of the warp and weft threads of the fabric layer 28B of the DRL electrode 64 relative to the circumferential direction of the steering wheel 12 is reduced (see FIG. 5B ), which allows the DRL electrode 64 (fabric layer 28B) to easily stretch in the circumferential direction of the steering wheel 12.

[0048] Furthermore, the DRL electrode 64 is disposed on the outer periphery of the rim portion 12B. Therefore, when the occupant grips the rim portion 12B, the occupant can contact the DRL electrode 64 with the palm of their hand, allowing the occupant to properly contact the DRL electrode 64.

[0049] Furthermore, in the cover body 20, both widthwise ends of the DRL electrode 64 are folded back and joined to the covering material 24 in an overlapping state. This allows the DRL electrode 64 to protrude more from the covering material 24, allowing the occupant's hand to more appropriately contact the DRL electrode 64 when gripping the rim portion 12B.

[0050] In this embodiment, the DRL electrode 64 is applied to the first embodiment. However, the DRL electrode 64 may be applied to the second embodiment.

[0051] In the first to third embodiments, the detection electrode 28 and the DRL electrode 64 have the rubber layer 28A on the front side and the fabric layer 28B on the rear side. However, at least one of the detection electrode 28 and the DRL electrode 64 may have the fabric layer 28B on the front side and the rubber layer 28A on the rear side.

[0052] Furthermore, in the first to third embodiments, the detection electrode 28 and the DRL electrode 64 are configured from the rubber layer 28A and the cloth layer 28B. However, at least one of the detection electrode 28 and the DRL electrode 64 may be configured from only the rubber layer 28A or only the cloth layer 28B.

[0053] The disclosure of Japanese Patent Application No. 2023-149371, filed on September 14, 2023, is incorporated herein by reference in its entirety.

[0054] 10: Steering cover, 12: Steering, 20: Cover body, 28: Detection electrode, 28A: Rubber layer, 28B: Fabric layer, 32: ECU (detection unit), 50: Steering cover, 60: Steering cover, 64: DRL electrode

Claims

1. A steering cover comprising: a cover body attached to a steering wheel operated by a vehicle occupant to steer the vehicle and covering the steering wheel; a pair of detection electrodes provided on the cover body and constituted by at least one of a fabric layer and a rubber layer; and a detection unit connected to the pair of detection electrodes and detecting the electrocardiogram waveform of the occupant in contact with the pair of detection electrodes.

2. A steering cover according to claim 1, wherein the detection electrodes are disposed on the front and outer circumferential side of the steering wheel.

3. A steering cover as claimed in claim 1 or claim 2, further comprising a DRL electrode provided on the cover body along the detection electrodes, which is in contact with an occupant and which inverts common-mode signal noise that has entered the pair of detection electrodes via the occupant and is fed back to the occupant.

4. A steering cover according to claim 3, wherein said DRL electrode is formed by at least one of said fabric layer and said rubber layer.

5. A steering cover according to any one of claims 1 to 4, wherein the threads constituting the fabric layer are inclined with respect to the circumferential direction of the steering wheel.

6. A steering cover according to any one of claims 1 to 5, wherein the detection electrodes are provided on the cover body in an overlapping state.

7. A steering cover according to any one of claims 1 to 6, wherein the detection electrodes are provided on the cover body by sewing.

8. A steering cover according to any one of claims 1 to 7, wherein the detection electrodes are wired through the inside of the cover body.

9. A steering cover according to any one of claims 1 to 8, wherein the cover body is stretched in the circumferential direction of the steering wheel and attached to the steering wheel.

10. A steering cover according to any one of claims 1 to 9, wherein the detection electrodes extend in the circumferential direction of the steering wheel.

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