Steering device

Abstract

A steering device is provided with a capacitive sensor unit that has an electrode provided to a rim section and detects a gripping operation of an occupant with respect to the rim section. The rim section has a skeleton section that extends along a closed curve having a predetermined shape and forms a skeleton of the rim section, and a skin section that covers the rim section over the entire circumference in the circumferential direction. When a region on the hub part side in a cross-section of the rim part obtained by cutting the rim part perpendicular to the closed curve is defined as an inner diameter side region and a region on the opposite side of the inner diameter side region is defined as an outer diameter side region, the electrodes are provided between the skeleton part and the skin part and extending across the circumferential direction in the inner diameter side region.

Description

Technical Field

[0001] This invention relates to a steering device capable of detecting the gripping state of the steering wheel. Background Technology

[0002] In recent years, initiatives aimed at providing sustainable transportation systems that take into account the vulnerable populations among traffic participants have become increasingly active. To achieve this goal, research and development related to driver assistance technologies has been undertaken. In this context, devices are known that install a capacitive sensor on the rim of the steering wheel to detect the driver's grip on the rim. Such a device is described, for example, in Patent Document 1.

[0003] In the device described in Patent Document 1, a conductive part that functions as a contact sensor is provided along the entire circumference of the rim. Furthermore, a blank portion is provided on the circumferentially downward side of the rim to cut or trim the conductive part, thereby reducing the contact sensitivity. As a result, when the occupant's abdomen or thigh comes into contact with the rim, it prevents false detection that the rim is being gripped.

[0004] However, as described in Patent Document 1, even if a blanking portion is provided on the circumferentially lower side of the rim, the occupant's body may sometimes come into contact with the rim outside the blanking portion due to factors such as the occupant's posture, the tilting motion of the steering wheel, and the rotation position of the steering wheel. In such cases, it is possible to mistakenly detect that the rim is being gripped.

[0005] Existing technical documents Patent documents Patent Document 1: Japanese Patent No. 6674556 (JP6674556B). Summary of the Invention

[0006] A vehicle steering device according to one embodiment of the present invention includes: a hub portion connected to a steering shaft; a rim portion extending around the hub portion along a closed curve of a predetermined shape in a circumferential direction around the hub portion and held by an occupant; and a spoke portion connecting the hub portion and the rim portion. The steering device also includes a capacitive sensor portion having electrodes disposed in the rim portion to detect the occupant's gripping action on the rim portion. The rim portion has a skeleton portion forming the frame of the rim portion and a skin portion covering the rim portion in a circumferential direction. When the region on the hub portion side of a cross-section of the rim portion cut perpendicularly to the closed curve is defined as the inner diameter side region, and the region on the opposite side of the inner diameter side region is defined as the outer diameter side region, the electrodes are disposed between the skeleton portion and the skin portion and extend circumferentially throughout the inner diameter side region. Attached Figure Description

[0007] The objectives, features, and advantages of the present invention are further illustrated by the following description of embodiments in conjunction with the accompanying drawings.

[0008] Figure 1 This is a side view showing a schematic structure near the driver's seat of a vehicle having a steering device according to an embodiment of the present invention; Figure 2 yes Figure 1 II-direction view; Figure 3 It is along Figure 2 A sectional view taken along line III-III; Figure 4A This is a front view of the rim of the steering wheel, showing the occupant's gripping action; Figure 4B yes Figure 4A Main section view; Figure 5 yes Figure 3 A cross-sectional view of the main part of the rim; Figure 6A This is a cross-sectional view of the main part of a substrate, showing an example of a substrate having an electrode positioning recess provided on the surface of the substrate in the rim portion; Figure 6B This is a cross-sectional view of the main part of the rim portion, showing an example of an electrode positioning recess provided on the surface of the substrate of the rim portion; Figure 7 This is a block diagram illustrating the control structure of a steering device according to an embodiment of the present invention; Figure 8 It is shown by Figure 7 A flowchart of an example of the processing performed by the controller; Figure 9 It is a diagram that roughly shows the positional relationship between the steering wheel and the lower limbs of the occupant; Figure 10 This is a front view showing a modified example of the rim. Detailed Implementation

[0009] The following is for reference Figures 1-10 Embodiments of the present invention will be described. The steering device of the embodiments of the present invention is mounted on a vehicle. The vehicle is, for example, an autonomous vehicle with an autonomous driving function that does not require driver operation. The vehicle may also be a manually driven vehicle that requires driver operation. Hereinafter, an example of the steering device being applied to an autonomous vehicle will be described. This autonomous vehicle is configured to be able to switch the driving mode from an autonomous driving mode that does not require driver operation to a manual driving mode that requires driver operation.

[0010] Figure 1This is a side view showing a schematic structure near the driver's seat of a vehicle 1 equipped with a steering device 100 according to an embodiment of the present invention. Hereinafter, the front-rear direction, left-right direction, and up-down direction are defined as shown in the figure, and the structure of each part will be described according to these definitions. The front-rear direction, left-right direction, and up-down direction are consistent with the front-rear direction (length direction), left-right direction (width direction), and up-down direction (height direction) of the vehicle 1.

[0011] Figure 1 This shows the occupant PS seated in the driver's seat 2 of vehicle 1. (Example) Figure 1 As shown, the steering system 100 is configured facing the driver's seat 2 and has a steering wheel 10 operated by the occupant PS. The steering wheel 10 is supported by the top end (rear end) of a steering shaft 11 that extends upward along the centerline CL0 from the front to the rear of the vehicle. The steering shaft 11 rotates integrally with the steering wheel 10 according to the operation of the steering wheel 10.

[0012] Although detailed illustrations are omitted, the steering device 100 includes a telescopic mechanism 12 and a tilting mechanism 13. The steering wheel 10 can be tilted in the forward and backward directions using the telescopic mechanism 12. Figure 1 The steering wheel 10 can move in the direction of arrow A and can also move vertically using tilting mechanism 13. Thus, the occupant PS can move the steering wheel 10 to any position. The telescopic mechanism 12 and tilting mechanism 13 are driven manually by the occupant. At least one of the telescopic mechanism 12 and tilting mechanism 13 can also be driven by an actuator (e.g., an electric motor).

[0013] Inside the vehicle, for example above the windshield, a camera 14 equipped with imaging elements such as a CCD (charge-coupled device) or a CMOS (complementary metal-oxide-semiconductor) is installed. The camera 14 captures images of the occupant PS, and based on the image signals acquired by the camera 14, the shape and posture of the occupant PS can be identified.

[0014] Figure 2 This is the front view of steering wheel 10. Figure 1 (View from direction II). For example... Figure 2 As shown, the steering wheel 10 has a hub portion 20 connected to the steering shaft 11, a generally annular rim portion 30 disposed around the hub portion 20, and a spoke portion 40 connecting the hub portion 20 and the rim portion 30. The centerline CL0 passes through the central portion of the hub portion 20 (e.g., the center of the hub portion 20), and the steering wheel 10 extends along a surface perpendicular to the centerline CL0. Hereinafter, the direction along a circle centered on the centerline CL0 will be defined as the circumferential direction, and the direction extending radially from the centerline CL0 will be defined as the radial direction.

[0015] The rim portion 30 extends along a circular or approximately circular reference line CL1 centered on the center line CL0. The rim portion 30 is not limited to being circular or approximately circular; it can also be rectangular or approximately rectangular. The rim portion 30 is held by the occupant PS, who uses it to operate the steering wheel 10. The spoke portion 40 consists of three spokes extending from the hub portion 20 to the left, right, and downward. The number of spokes 40 can also be two or four, and the configuration of the spoke portion 40 is not limited to that shown in the figure.

[0016] The rim portion 30 has the same cross-sectional shape throughout the circumference. Figure 3 This is a sectional view showing the rim portion 30 cut perpendicularly to the baseline CL1 (along...). Figure 2 (Cross-sectional view taken along line III-III). Baseline CL1 is located at the center of the section of the rim portion 30. Figure 3 The diagram shows a straight line L1 extending along a plane FS1 perpendicular to the center line CL0 through the baseline CL1, and a straight line L2 (a straight line perpendicular to line L1) parallel to the center line CL0 through the baseline CL1. Line L2 extends downward in the front-back direction, more specifically forward, and along a generally cylindrical curved surface CS1 centered on the center line CL0.

[0017] like Figure 3 As shown, the rim portion 30 has a core rib 31, a base material 32, and a skin 33. The core rib 31 is located in the center of the rim portion 30. The core rib 31 is formed of a high-rigidity metal material such as stainless steel. The core rib 31 extends along the reference line CL1, forming the skeleton portion that constitutes the framework of the rim portion 30. Figure 3 In this design, the core rib 31 is set to have a roughly circular cross-section, but the core rib 31 can also be tubular (roughly cylindrical). The cross-section is curved into a roughly C-shaped or U-shaped form.

[0018] The substrate 32 has a generally cylindrical cross-section. The substrate 32 is formed to surround the entire outer circumferential surface of the core 31, defining the overall shape of the rim portion 30. The substrate 32 is formed of a material with lower stiffness than the core 31 (e.g., a resin material such as non-conductive polyurethane), constituting the base of the rim portion 30. The skin 33 covers the entire outer circumferential surface of the substrate 32, with its surface exposed to the outside. That is, the skin 33 constitutes a skin portion that covers the entire circumference of the rim portion 30. When an occupant holds the rim portion 30, the occupant's hand comes into contact with the skin 33. The skin 33 is made of resin material, leather, wood, etc.

[0019] exist Figure 3In the cross-section of the rim portion 30, the region AR1, which is radially inward of the curved surface CS1 (straight line L2) and on the side opposite to the centerline CL0, is called the inner diameter side region. The region AR2, which is radially outward of the curved surface CS1 and on the opposite side of the centerline CL0, is called the outer diameter side region. Furthermore, the region forward of the plane FS1 (straight line L1) is called the front side region AR3, and the region rearward (occupant side) of the plane FS1 is called the rear side region AR4. The front side region AR3 is the region on the base end side of the steering shaft 11, and the rear side region AR4 is the region on the top end side of the steering shaft 11.

[0020] The steering device 100 of this embodiment also includes a capacitive sensor unit 60 for detecting the occupant's gripping action on the wheel rim portion 30. The sensor unit 60 includes a power source (not shown), an electrode 61 disposed on the wheel rim portion 30, and a detection circuit 62 for detecting the capacitance or changes in capacitance of the electrode 61. Figure 7 The detection circuit 62 detects, for example, the electrical characteristics of electrode 61, namely the capacitance between electrode 61 and ground (vehicle body). When the object being detected (occupant's body) approaches electrode 61, the capacitance detected by the detection circuit 62 increases; when the object being detected (occupant's body) moves away from electrode 61, the capacitance detected by the detection circuit 62 decreases.

[0021] like Figure 3 As shown, electrode 61 is sandwiched between substrate 32 and epidermis 33, covering the entire area of ​​the inner diameter side region AR1 and the front region AR3 of rim portion 30. In other words, electrode 61 is positioned on the opposite side from the side facing the occupant's lower limbs and the opposite side from the side facing the occupant's abdomen. Electrode 61 is arranged along the outer peripheral surface of substrate 32, and its overall shape is a quarter circle. Figure 2 As shown by the dashed line, one end of a pair of signal lines 45 is connected to electrode 61. The signal lines 45 are arranged inside the spoke portion 40 along the spoke portion 40, and their other ends are connected to the detection circuit 62.

[0022] Figure 4A This is a front view of the rim portion 30 showing the occupant's gripping action (viewed from the occupant's side, i.e., from the rear). Figure 4B yes Figure 4A A sectional view of the main parts. For convenience, in Figure 4A The illustrations of the hub portion 20 and the spoke portion 40 of the steering wheel 10 are omitted.

[0023] like Figure 4A , 4BAs shown, when the occupant grips the rim portion 30, the area from the CM (carpal joint) to the MP (palmopododigital joint) of the occupant's palm, as well as the thenar eminence (referred to as the wrist-side region AR10), is mainly located in the outer diameter side region AR2 of the rim portion 30. On the other hand, the area from the base of the fingers to the fingertips (referred to as the finger-side region AR20) is mainly located in the inner diameter side region AR1. At this time, the finger-side region AR20 is close to the electrode 61. As a result, the capacitance of the electrode 61 increases, enabling the detection of the occupant's gripping action on the steering wheel 10.

[0024] In particular, the electrode 61 is disposed in the inner diameter side region AR1 of the rim portion 30 of the wheel rim portion 30, which is the finger-side region AR20 facing the occupant's hand, thus enabling high-precision detection of the occupant gripping the steering wheel 10 (rim portion 30). In other words, since the electrode 61 is not present in the outer diameter side region AR2, even if the occupant's lower limbs or the like come into contact with the rim portion 30, the sensor unit 60 can be prevented from falsely detecting the contact.

[0025] Figure 5 The structure of electrode 61 is shown in detail. Figure 3 A sectional view of the main part of the rim section 30. (See attached image.) Figure 5 As shown, electrode 61 has a pair of electrode layers (inner electrode layer 611 and outer electrode layer 612) that are generally thin plates and an insulating layer 613 sandwiched between the pair of electrode layers 611 and 612.

[0026] An adhesive (adhesive layer) 63 is applied to the outer peripheral surface of the substrate 32 to form an adhesive layer. The inner electrode layer 611 is... Figure 3 The inner diameter side region AR1 and the front side region AR3 are bonded to the outer peripheral surface of the substrate 32 using adhesive 63 over the entire circumference of the rim portion 30. The outer electrode layer 612 is disposed over the entire area of ​​the inner electrode layer 611, facing the inner peripheral surface of the skin 33 in a manner that is separated from the inner electrode layer 611 by an insulating layer 613.

[0027] In this embodiment, electrode 61 is only disposed in a portion of the circle centered on the baseline CL1 (inner diameter side region AR1 and front side region AR3). Figure 3 Therefore, compared to the case where electrodes 61 are arranged in a circular pattern centered on the baseline CL1, the area of ​​electrode 61 is smaller. As a result, the detection sensitivity of sensor unit 60 is prone to decrease, but because an insulating layer 613 is sandwiched between a pair of electrode layers 611 and 612 to form electrode 61, the decrease in detection sensitivity of sensor unit 60 can be suppressed.

[0028] In this embodiment, the electrode 61 is mounted overlapping the surface of the substrate 32. Therefore, compared to the case where the electrode 61 is disposed inside the rim portion 30 by insert molding, it is easier to install the electrode 61, and the manufacturing cost of the steering wheel 10 with the electrode 61 can be reduced. Furthermore, the signal line 45 connected to the electrode 61 ( Figure 2 The signal lines 45 are arranged along the spoke portion 40. Therefore, compared with the case where the electrode 61 is provided inside the rim portion 30 by insert molding, the signal lines 45 can be arranged more easily.

[0029] As described above, the electrode 61 is bonded and fixed to the outer peripheral surface of the substrate 32. However, in this state, the position of the electrode 61 may shift due to temperature changes in the external environment causing the substrate 32 to expand and compress. Therefore, a concave locking portion can be provided to restrict the position of the electrode 61 to prevent the electrode 61 from shifting. Figure 6A This is a diagram that schematically illustrates the example.

[0030] like Figure 6A As shown, a recess 35 with a depth equivalent to the thickness of the electrode 61 is provided on the outer peripheral surface of the substrate 32, and a locking portion 36 protruding circumferentially to cover both ends of the recess 35 in the circumferential direction. When the electrode 61 is disposed in the recess 35, firstly, while bending the electrode 61, one end of the electrode 61 is inserted into the inside of the locking portion 36 on one circumferential end side of the recess 35. Next, while bending the central portion of the electrode 61 into a convex shape towards the opposite side of the recess 35, the other end of the electrode 61 is inserted into the inside of the locking portion 36 on the other circumferential end side of the recess 35. Thus, as Figure 6A As shown by the dashed line, the electrode 61 can be integrally disposed in the recess 35.

[0031] Figure 6B To show in more detail Figure 6A A cross-sectional view of the configuration of electrode 61. (See attached image.) Figure 6B As shown, an electrode 61 (inner electrode layer 611, insulating layer 613, and outer electrode layer 612) is disposed in the recess 35 using an adhesive 63. With the electrode 61 disposed in the recess 35, both circumferential ends of the electrode 61 are covered by a locking portion 36. This restricts the position of the electrode 61, preventing it from shifting. After the electrode 61 is disposed in the recess 35, the electrode 61 and the locking portion 36 are covered by a skin 33.

[0032] Figure 7 This is a block diagram illustrating the control structure of the steering device 100 according to this embodiment. Figure 7As shown, the steering system 100 includes a sensor unit 60, a camera 14, a controller 50, a notification device 55, and an automatic driving system 56. The notification device 55 is a device used to notify the occupant of their grip requirements on the steering wheel 10, and consists of a speaker and a monitor.

[0033] Signals from the detection circuit 62 and the camera 14 are input to the controller 50. The controller 50 is configured as a computer having a CPU (Central Processing Unit), ROM (Read-Only Memory), RAM (Random Access Memory), and other peripheral circuits. The controller 50 functions as a threshold setting unit 51, a determination unit 52, and an output unit 53.

[0034] The threshold setting unit 51 identifies the occupant's body shape and posture based on the image signal acquired by the camera 14. Furthermore, based on the identified body shape and posture, it sets a threshold Ca for determining the grip of the steering wheel 10. The threshold setting unit 51 calculates the shortest distance from the occupant's lower limbs and abdomen to the steering wheel 10 based on the identified body shape and posture; the smaller the distance, the larger the threshold Ca is set to. That is, the closer the lower limbs, etc., are to the steering wheel 10, the larger the threshold Ca is.

[0035] The determination unit 52 determines whether the capacitance C detected by the detection circuit 62 is above the threshold Ca set by the threshold setting unit 51. Furthermore, if the capacitance C is above the threshold Ca (C≥Ca), the determination unit 52 determines that the steering wheel 10 is being held. On the other hand, if the capacitance C is below the threshold Ca (C<Ca), the determination unit 52 determines that the steering wheel 10 is not being held.

[0036] The output unit 53 outputs the determination result of the determination unit 52 to the notification device 55 and the automatic driving system 56. Furthermore, the output unit 53 communicates with the automatic driving system 56 to determine whether a request to hold the steering wheel 10 has been output from the automatic driving system 56. Then, when a holding request is output from the automatic driving system 56, a signal is output to the notification device 55 to notify the occupant to hold the steering wheel 10.

[0037] For example, while the vehicle 1 is driving in autonomous driving mode, the autonomous driving system 56 determines whether it is necessary to switch from autonomous driving mode to manual driving mode based on the conditions around the vehicle 1 and the condition of the vehicle itself. Then, when it is determined that a switch from autonomous driving mode to manual driving mode is necessary (for example, when changing the autonomous driving level from level 3 to level 2), the autonomous driving system 56 outputs a steering wheel grip requirement.

[0038] Figure 8This is a flowchart illustrating an example of a process executed by the CPU of controller 50 according to a pre-stored program. For example, when vehicle 1 is driving in autonomous driving mode, the process begins when the autonomous driving system 56 outputs a request to hold the steering wheel 10, that is, when a request to hold the steering wheel 10 is reported from the notification device 55, and repeats at a predetermined cycle. Alternatively, the process shown in the flowchart can begin whenever the power switch of vehicle 1 is turned on, regardless of whether a holding request is output.

[0039] First, in step S1 (S: processing step), the CPU of the controller 50 reads signals from the sensor unit 60 (detection circuit 62) and the camera 14. Next, in step S2, the CPU identifies the occupant's body shape and posture based on the image signal from the camera 14, and sets a threshold Ca based on the occupant's body shape and posture. Specifically, based on the identified occupant's body shape and posture, the shortest distance from the occupant's lower limbs or abdomen to the steering wheel 10 is calculated; the smaller the distance, the larger the threshold Ca is set to. Next, in step S3, the CPU determines whether the capacitance C detected by the sensor unit 60 is above the threshold Ca.

[0040] When S3 is affirmative (S3: Yes), proceed to S4; when S3 is negative (S3: No), proceed to S5. In S4, the CPU outputs a control signal indicating that the steering wheel 10 is being controlled to the notification device 55 and the automatic driving system 56. This stops the notification of the control request for the steering wheel 10.

[0041] On the other hand, in S5, a non-control signal indicating that the steering wheel 10 is not being held is output to the notification device 55 and the automatic driving system 56. The notification device 55 continues to notify the control request as long as it outputs the non-control signal. Although the notification device 55 notifies the control request within a specified time, when no control signal is output, that is, when the occupant is not holding the steering wheel 10, the automatic driving system 56 performs the vehicle 1's prescribed action (e.g., a stop action).

[0042] The operation of the steering device 100 in this embodiment is summarized below. During automatic driving mode, when a switch to manual driving mode is required, the notification device 55 notifies the driver of a requirement to hold the steering wheel 10. Consequently, the occupant (driver) holds the steering wheel 10. When the steering wheel 10 is held, the capacitance C detected by the sensor unit 60 increases, and capacitance C exceeds the threshold Ca. As a result, a holding signal is output to the automatic driving system 56, and the driving mode is switched to manual driving mode (S4).

[0043] In this case, the electrode 61 of the sensor unit 60 is disposed in the inner diameter side region AR1 and the front side region AR3 of the rim portion 30. Figure 3 Therefore, when the occupant grips the rim portion 30, the finger-side area AR20 ( Figure 4AWhen the steering wheel 10 approaches electrode 61, the capacitance C detected by sensor unit 60 increases. This allows for accurate detection of the steering wheel 10's gripping motion.

[0044] Figure 9 This diagram schematically illustrates the positional relationship between the steering wheel 10 and the occupant's lower limbs (around the thighs) PS1. (See diagram for example.) Figure 9 As shown, the occupant's lower limb PS1 is closest to the outer diameter side region AR2 and the rear region AR4 of the lower part of the steering wheel 10, i.e., region ARa. In this embodiment, the electrode 61 is not provided in region ARa, but the electrode 61 is provided in the inner diameter side region AR1 and the front region AR3, i.e., region ARb, which is furthest from the lower limb PS1. Therefore, there is no occupant in the direction of the electric field line of the electrode 61 indicated by the arrow, which can prevent the occupant's hands from approaching the steering wheel 10 and falsely detecting the grip of the steering wheel 10.

[0045] In the above text, a single electrode 61 is provided around the entire circumference of the rim portion 30, but multiple electrodes 61 can also be provided in the circumferential direction. Figure 10 This is a front view (viewed from the rear) of the rim portion 30 in this example. Figure 10 As shown, electrode 61 is divided into four equal parts by axes CL11, CL12, CL13, and CL14 extending radially outward from the center line CL0. Therefore, in the inner diameter side region AR1 and the front side region AR3 of the rim portion 30... Figure 3 Four electrodes 61A, 61B, 61C, and 61D (dashed lines) are set in the circumferential direction.

[0046] Each electrode 61A to 61D is connected to a separate detection circuit 62. Figure 7 ), Figure 10 The steering system 100 has four sensor units 60. Therefore, in addition to determining whether the steering wheel 10 is being gripped, the CPU can also determine which area of ​​the steering wheel 10 is being gripped circumferentially. Figure 10 In this configuration, electrode 61 is divided into four parts in the circumferential direction, but it can also be divided into two parts, three parts, or five or more parts, with multiple electrodes 61 arranged in the circumferential direction. When electrode 61 is divided into multiple parts in the circumferential direction, the division can also be uneven in the circumferential direction.

[0047] The following effects can be achieved by adopting this implementation method.

[0048] (1) The steering device 100 for a vehicle includes: a hub portion 20 connected to a steering shaft 11; a rim portion 30 extending around the hub portion 20 along a generally circular reference line CL1 in a circumferential direction centered on the hub portion 20 and held by an occupant; and a spoke portion 40 connecting the hub portion 20 and the rim portion 30. Figure 1 , Figure 2 The steering system 100 also includes a capacitive sensor unit 60, which has electrodes 61 disposed on the wheel rim portion 30 to detect the occupant's gripping action on the wheel rim portion 30. Figure 7 The rim portion 30 has a core 31 forming the skeleton of the rim portion 30 and a skin 33 covering the entire circumference of the rim portion 30 in the circumferential direction. Figure 3 When the region on the side of the hub portion 20 in a cross-section of the rim portion 30, which is cut perpendicularly to the baseline CL1, is defined as the inner diameter side region AR1, and the region on the opposite side of the inner diameter side region AR1 is defined as the outer diameter side region AR2, the electrode 61 is circumferentially extended between the core 31 and the epidermis 33 and throughout the inner diameter side region AR1. Figure 3 , Figure 4A ).

[0049] By placing the electrode 61 in the inner diameter side region AR1 of the rim portion 30, false detection of the steering wheel 10 being held by the occupant can be prevented when the occupant's lower limbs are in contact with the steering wheel 10. The electrode 61 is distributed throughout the entire circumference of the rim portion 30, eliminating the need for blank areas without the electrode 61 in the circumferential direction of the steering wheel 10. Therefore, the steering wheel 10 is easily constructed. Since the electrode 61 is located in the inner diameter side region AR1 of the rim portion 30 in any region of the circumferential direction of the steering wheel 10, the holding state of the steering wheel 10 can be detected with high accuracy regardless of the occupant's posture, the tilting motion of the steering wheel 10, or the rotational position of the steering wheel 10.

[0050] (2) Electrode 61 is provided circumferentially in the inner diameter side region AR1 of the rim portion 30, on the base end side of the steering shaft 11, i.e., the front side region AR3 of the vehicle 1. Figure 3 , Figure 4A In this way, the electrode 61 is provided in the front region AR3, which is furthest from the occupant in the inner diameter region AR1 of the rim portion 30, thereby effectively preventing false detection of gripping actions when the occupant's hands or other parts of the steering wheel 10 are in contact with the steering wheel 10.

[0051] (3) The rim portion 30 also has a base material 32 that surrounds the core 31 around the entire circumference. Figure 2 Electrode 61 has an inner electrode layer 611 mounted on the surface of substrate 32, an outer electrode layer 612 facing the skin 33 and disposed opposite to the inner electrode layer 611, and an insulating layer 613 sandwiched between the inner electrode layer 611 and the outer electrode layer 612. Figure 5 Therefore, compared to the case where the electrode 61 is embedded in the rim portion 30 by insert molding, the electrode 61 can be easily placed in the rim portion 30.

[0052] (4) The steering device 100 also includes an adhesive 63, which is disposed on the surface of the substrate 32 and adheres to the inner electrode layer 611. Figure 5 Therefore, the installation process of electrode 61 is simple, which can reduce the manufacturing cost of steering device 100.

[0053] (5) The substrate 32 has a concave locking portion 36 for locking the end of the electrode 61 in the circumferential direction. Figure 6A , Figure 6B Therefore, it is possible to prevent the position of electrode 61 from shifting in the event of temperature changes in the external environment causing the substrate 32 to expand or compress.

[0054] (6) The sensor section 60 also has a signal line 45, one end of which is electrically connected to the electrode 61 and extends along the spoke section 40. Figure 2 Therefore, it is easy to arrange signal lines 45.

[0055] (7) The steering device 100 further includes: a camera 14 that detects the body shape and posture of the occupant; a determination unit 52 that determines whether the rim portion 30 is being held based on the magnitude of the capacitance detected by the electrode 61 and a threshold Ca; and a threshold setting unit 51 that sets a threshold Ca based on the body shape and posture of the occupant detected by the camera 14. Figure 1 , Figure 7 Therefore, regardless of the occupant's body shape or posture, it is possible to determine with high precision whether the steering wheel 10 is being held.

[0056] (8) Electrode 61 may also be a plurality of electrodes 61 (61A, 61B, 61C, 61D) that are divided circumferentially and arranged on the rim portion 30. Figure 10 In this case, the controller 50 also functions as a gripping area determination unit, which determines the gripping area of ​​the occupant on the rim portion 30 based on signals from multiple electrodes 61. With this structure, it is possible to determine which circumferential region of the steering wheel 10 the occupant is gripping.

[0057] This embodiment can be modified in various ways. Several modifications will be described below. In the above embodiment, the electrode 61 is provided throughout the circumferential direction of the rim portion 30, centered on the center line CL0, in the inner diameter side region AR1 and the front side region AR3. However, as long as it is provided in the inner diameter side region AR1 of the rim portion 30, part or all of the electrode 61 can also be provided in the rear side region AR4. The electrode 61 can also be provided in a portion of the circumferential direction centered on the center line CL0. In the above embodiment, the electrode 61 is provided in a quarter circle region of the cross section of the rim portion 30 centered on the reference line CL1. However, as long as it is provided at least in the inner diameter side region AR1, the electrode 61 can also be provided in a region narrower or wider than a quarter circle.

[0058] In the above embodiment, the rim portion 30 extends around the hub portion 20 along a generally circular closed curve, i.e., the reference line CL1. However, the overall shape of the rim portion 30, i.e., the shape of the closed curve (prescribed shape), is not limited to a circle. For example, the rim portion 30 may also be elliptical or generally rectangular. In the above embodiment, the electrode 61 is formed by an inner electrode layer 611 (first electrode layer) and an outer electrode layer 612 (second electrode layer) facing each other with an insulating layer 613 between them. However, the electrode configuration is not limited to the above description. In the above embodiment, the inner electrode layer 611 is bonded to the surface of the substrate 32 using an adhesive 63. However, the electrode 61 can also be disposed on the rim portion 30 by other methods. In the above embodiment, the signal line 45 connected to the electrode 61 extends along the spoke portion 40. However, the wire extending along the spoke portion is not limited to a signal line.

[0059] In the above embodiment, the camera 14 detects the occupant's body shape and posture, but the configuration of the detection unit is not limited to those described above. The detection unit can also detect the occupant's body shape or posture. For example, one or more seating sensors can be provided on the seating surface of the seat cushion and / or seat back, and the occupant's body shape or posture can be detected based on signals from the seating sensors. Therefore, the threshold setting unit 51 can set a threshold Ca based on the occupant's body shape or posture. Sometimes, when the position of the steering wheel 10 is adjusted by the telescopic mechanism 12 and the tilting mechanism 13, the positional relationship between the occupant and the steering wheel 10 remains constant regardless of the occupant's body shape. Therefore, the detection unit (e.g., camera 14) can also detect the proximity of the steering wheel 10 to the occupant PS's body (e.g., lower limbs), and the threshold setting unit 51 can set the threshold Ca based on the detection result.

[0060] It is possible to combine one or more of the above-described embodiments and variations, and to combine the variations with each other.

[0061] Using this invention, the gripping status of the steering wheel can be detected with high precision.

[0062] The present invention has been described above in conjunction with preferred embodiments, but those skilled in the art should understand that various modifications and changes can be made without departing from the scope of the claims.

Claims

1. A steering device, a steering device (100) for a vehicle, comprising: The hub (20) is connected to the steering shaft (11); A rim portion (30), which extends around the hub portion (20) along a closed curve (CL1) of a predetermined shape on the circumference of the entire circumference centered on the hub portion (20), and is held by the occupant; and The spoke portion (40) connects the hub portion (20) and the rim portion (30). The steering device is characterized in that... It also includes a capacitive sensor unit (60), which has electrodes (61) disposed on the rim portion (30) to detect the occupant's gripping action on the rim portion (30). The rim portion (30) has a skeleton portion (31) forming the skeleton of the rim portion (30) and a skin portion (33) covering the entire circumference of the rim portion (30). When the region on the side of the hub portion (20) in the cross section of the rim portion (30) which is cut perpendicularly to the closed curve (CL1) is defined as the inner diameter side region (AR1), and the region on the opposite side of the inner diameter side region (AR1) is defined as the outer diameter side region (AR2), the electrode (61) is provided circumferentially between the skeleton portion (31) and the skin portion (33) and throughout the inner diameter side region (AR1).

2. The steering device according to claim 1, characterized in that, The electrode (61) extends circumferentially throughout the region (AR3) on the base end side of the steering shaft (11) in the inner diameter side region (AR1) of the cross section of the rim portion (30).

3. The steering device according to claim 1 or 2, characterized in that, The rim portion (30) also has a base (32) that surrounds the skeleton portion (31) around the entire circumference. The electrode (61) has a first electrode layer (611) mounted on the surface of the base (32), a second electrode layer (612) facing the epidermis (33) and disposed opposite to the first electrode layer (611), and an insulating layer (613) sandwiched between the first electrode layer (611) and the second electrode layer (612).

4. The steering device according to claim 3, characterized in that, It also includes an adhesive portion (63), which is disposed on the surface of the base (32) and adheres to the first electrode layer (611).

5. The steering device according to claim 3, characterized in that, The base (32) has a concave locking portion (36) for locking the electrode (61) at its end in the circumferential direction.

6. The steering device according to claim 1 or 2, characterized in that, The sensor section (60) also has a wire (45) with one end electrically connected to the electrode (61) and extending along the spoke section (40).

7. The steering device according to claim 1 or 2, characterized in that, It also has: The detection unit (14) detects at least one of the occupant's body shape and posture; The determination unit (52) determines that the rim portion (30) is being held based on the difference between the capacitance detected by the electrode (61) and the threshold (Ca). as well as The threshold setting unit (51) sets the threshold (Ca) based on at least one of the occupant's body shape and posture detected by the detection unit (14).

8. The steering device according to claim 7, characterized in that, The determination unit (52) calculates the shortest distance from the lower limb of the occupant to the rim (30) based on at least one of the occupant's body shape and posture detected by the detection unit (14). The shorter the shortest distance, the larger the threshold (Ca) is set.

9. The steering device according to claim 1 or 2, characterized in that, The electrode (61) is a plurality of electrodes (61A, 61B, 61C, 61D) that are divided into multiple parts in the circumferential direction and arranged in the rim portion (30). The steering device also includes a gripping area determining unit, which determines the gripping area of ​​the occupant on the rim portion (30) based on signals from the plurality of electrodes (61A, 61B, 61C, 61D).

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