Sensor device and steering device

Abstract

This sensor device comprises: a housing; a detection electrode which is provided on the outer peripheral surface of the housing so as to face a rim part and is capacitively coupled to the hand of a driver gripping the rim part to detect electrostatic capacitance; an operation knob which has an operation surface exposed from an opening of a decorative cover and is disposed such that the operation surface faces the driver; a substrate which is provided in the internal space of the housing; and an input operation detection unit which is provided on the substrate and detects an input operation to the operation knob by the driver. The housing has a restriction wall which restricts water that has entered from the periphery of the operation knob in the opening of the decorative cover from reaching the detection electrode and the substrate when the sensor device is submerged in water in any of an initial state of a steering wheel and a state of rotation operation in an arbitrary direction.

Description

Sensor device and steering device

[0001] The present invention relates to a sensor device and a steering device.

[0002] The following Patent Document 1 discloses a technology for detecting contact of a passenger's hand with the connection part between the rim and the spoke part of a steering wheel having a switch on the spoke part using an electrode on the spoke part.

[0003] Japanese Patent Application Laid-Open No. 2023-063050

[0004] However, with the technology of Patent Document 1, if water gets on the spokes of the steering wheel, the water that seeps in from around the switch may reach the electrode and capacitively couple with the electrode, which may prevent the electrode from detecting the contact of the occupant's hand with high accuracy.

[0005] Furthermore, in the steering wheel of Patent Document 1, if a circuit board on which a detection means for detecting the operation of the switch is mounted is provided on the back side of the switch, there is a risk that water that seeps in from around the switch will reach the circuit board, causing the detection means mounted on the circuit board to be unable to accurately detect the operation of the switch.

[0006] In one embodiment, the sensor device is mounted on the spokes of a steering wheel having a rim portion gripped by the driver, a hub portion located in the center of the rim portion, and spoke portions extending from the hub portion to support the rim portion, and is covered with a decorative cover having an opening. The sensor device comprises: a housing; a detection electrode located on the outer peripheral surface of the housing opposite the rim portion and which capacitively couples with the driver's hand gripping the rim portion to detect capacitance; an operation knob having an operation surface exposed from the opening in the decorative cover and positioned so that the operation surface faces the driver; a substrate located in the internal space of the housing; and an input operation detection unit located on the substrate that detects input operations made by the driver on the operation knob. The housing has a restricting wall that prevents water that enters from around the operation knob at the opening in the decorative cover from reaching either the detection electrode or the substrate when the sensor device becomes wet, whether the steering wheel is in its initial state or is rotated in any direction.

[0007] According to the sensor device of one embodiment, when the sensor device is submerged in water, water that has entered from around the operation knob can be prevented from reaching either the detection electrode or the substrate.

[0008] 1 is a plan view of a steering device according to an embodiment; 2 is a schematic cross-sectional view of a steering device according to an embodiment; 3 is an enlarged view of a periphery of a sensor device in a steering device according to an embodiment (when a decorative cover is not attached); 4 is an enlarged view of a periphery of a sensor device in a steering device according to an embodiment (when a decorative cover is attached); 5 is an external perspective view of a sensor device according to an embodiment;

[0009] Hereinafter, an embodiment will be described with reference to the drawings.

[0010] (Configuration of Steering Device 10) FIG. 1 is a plan view of a steering device 10 according to one embodiment.

[0011] In the following description, for convenience, the X-axis direction will be referred to as the left-right direction, the Y-axis direction as the front-rear direction, and the Z-axis direction as the up-down direction. However, the positive X-axis direction will be referred to as the right direction, the positive Y-axis direction as the forward direction, and the positive Z-axis direction as the upward direction. These directions indicate relative positional relationships within the device and do not limit the installation direction or operation direction of the device. Any devices that have the same relative positional relationship within the device, even if the installation direction or operation direction is different, are all included in the scope of the present invention.

[0012] The steering device 10 shown in FIG. 1 is mounted in the cabin of a vehicle such as an automobile, and is used by a driver to operate the steering wheel and perform various input operations for the vehicle.

[0013] As shown in FIG. 1, the steering device 10 includes a steering wheel 12 and two sensor devices 100 (sensor devices 100L and 100R).

[0014] The steering wheel 12 is comprised of a rim portion 13, spokes 14, and a hub portion 15. The rim portion 13 is an annular portion that is gripped by the driver's fingers to operate the steering wheel. Although not shown, the cross-sectional configuration of the rim portion 13 includes a metal rim core portion located in the center and a resin (e.g., urethane) covering portion that covers the outer surface of the rim core portion. The left side (negative side of the X-axis) of the rim portion 13 forms a grip portion 13L that is gripped by the fingers of the driver's left hand. The right side (positive side of the X-axis) of the rim portion 13 forms a grip portion 13R that is gripped by the fingers of the driver's right hand. Note that while both the steering wheel 12 and the rim portion 13 in this embodiment are annular, they are not limited thereto and may have various shapes, such as a special shape in which only the lower portion is connected and the upper portion is cut off, or a rim having a linear portion.

[0015] The hub portion 15 is provided at the center of the rim portion 13 and supports the spoke portions 14. The spoke portions 14 extend from the hub portion 15 in the radially outer direction of the rim portion 13 and support the rim portion 13 from the inside. In this embodiment, as an example, the spoke portions 14 have a first portion 14A extending rightward (positive direction of the X-axis) from the hub portion 15, a second portion 14B extending leftward (negative direction of the X-axis) from the hub portion 15, and a third portion 14C extending downward (negative direction of the Z-axis) from the hub portion 15. In other words, the spoke portions 14 are generally T-shaped in a plan view.

[0016] The right-side (X-axis positive) end of the first portion 14A of the spoke portion 14 is connected to the rim core metal portion of the rim portion 13 in the region of the gripping portion 13R of the rim portion 13. The left-side (X-axis negative) end of the second portion 14B of the spoke portion 14 is connected to the rim core metal portion of the rim portion 13 in the region of the gripping portion 13L of the rim portion 13. The lower-side (Z-axis negative) end of the third portion 14C of the spoke portion 14 is connected to the rim core metal portion of the rim portion 13. In this way, the spoke portion 14 supports the rim portion 13 from the inside.

[0017] The spoke portions 14 and hub portion 15 are each composed of a metallic spoke core portion that forms the base of the spoke portion 14, a metallic hub core portion that forms the base of the hub portion 15, a resin (e.g., urethane) covering portion that covers the outer surfaces of the spoke core portions and hub core portions, and functional parts such as a resin decorative cover 16 and a horn that are attached to the rider-side surfaces of the spoke core portions and hub core portions.

[0018] The hub portion 15 has a through hole 15A formed in the hub core metal portion, and is fixed to a steering shaft (not shown) inserted into the through hole 15A with a nut (not shown) or the like. This allows the hub portion 15 to rotate together with the steering wheel 12 in response to steering operation, thereby allowing the steering shaft to rotate about the central axis.

[0019] The sensor devices 100L and 100R are installed on the spokes 14 to perform various input operations. The sensor device 100R is installed on a first portion 14A of the spokes 14. The sensor device 100L is installed on a second portion 14B of the spokes 14. The sensor devices 100L and 100R have a substantially rectangular shape in a plan view from the driver's side (negative side of the Y axis), and are symmetrical to each other with respect to a plane passing through the center of the steering wheel 12. The driver's side (negative side of the Y axis) surface of each of the sensor devices 100L and 100R serves as an operation surface 100A on which various input operations are performed.

[0020] The sensor device 100L is provided near the grip portion 13L of the rim portion 13. The sensor device 100L allows input operation of the operation surface 100A with the fingers of the driver's left hand gripping the area of ​​the grip portion 13L. The sensor device 100L can also detect the grip state of the grip portion 13L with the driver's left hand in a non-contact manner.

[0021] The sensor device 100R is provided near the grip portion 13R of the rim portion 13. The sensor device 100R allows input operation of the operation surface 100A with the fingers of the driver's right hand gripping the area of ​​the grip portion 13R. The sensor device 100R can also detect the grip state of the grip portion 13R with the driver's right hand in a non-contact manner.

[0022] Fig. 2 is a schematic cross-sectional view of the sensor device 100R in the steering device 10 according to one embodiment. Fig. 3 is an enlarged view of the periphery of the sensor device 100R in the steering device 10 according to one embodiment (when the decorative cover 16 is not attached). Fig. 4 is an enlarged view of the periphery of the sensor device 100R in the steering device 10 according to one embodiment (when the decorative cover 16 is attached).

[0023] As shown in FIG. 3 , the sensor device 100R has a plurality of operation knobs 140 aligned on an operation surface 100A, which is the surface on the driver's side. The sensor device 100R is installed on a first portion 14A of the spoke portion 14 of the steering wheel 12. As shown in FIG. 4 , a resin decorative cover 16 is attached to the driver's side of the spoke portion 14 of the steering wheel 12. As a result, as shown in FIGS. 2 and 4 , the sensor device 100R is mounted on the first portion 14A of the spoke portion 14 of the steering wheel 12 with the plurality of operation knobs 140 exposed through openings 16A formed in the decorative cover 16, and the periphery of the sensor device 100R on the driver's side is covered by the decorative cover 16. As a result, a planar operation surface 100A is formed on the driver's side of the sensor device 100R together with the surface of the decorative cover 16 and the surfaces of the plurality of operation knobs 140.

[0024] As described above, the decorative cover 16 is formed with openings 16A shaped to conform to the outer shapes of the multiple operation knobs 140 as viewed from the driver's side. As shown in Figures 2 and 4, the multiple operation knobs 140 provided in the sensor device 100R are exposed from the openings 16A formed in the decorative cover 16, allowing them to be operated from the driver's side. In this embodiment, the operation is a pressing operation, but this is not limited to this, and any other input operation such as a tilting operation is also possible.

[0025] Note that small gaps are formed around the plurality of operation knobs 140 in the opening 16A. Therefore, when the steering device 10 according to one embodiment is exposed to water from above the decorative cover 16, there is a risk that water may seep in from around the plurality of operation knobs 140 in the opening 16A to the back side of the decorative cover 16.

[0026] (Configuration of sensor device 100) The configuration of the sensor device 100 will be described below using the sensor device 100R as a representative example. Fig. 5 is an external perspective view of the sensor device 100R according to one embodiment. Fig. 6 is an exploded perspective view of the sensor device 100R according to one embodiment.

[0027] As shown in FIGS. 2, 5 and 6, the sensor device 100R includes a housing 110, an electrostatic detection unit 120, a plurality of operation knobs 140, a bottom case 150, and a substrate 160.

[0028] The housing 110 is a resin container-shaped member that is thin in the front-to-rear direction (Y-axis direction) and has an internal space. The housing 110 has a generally rectangular shape when viewed from the driver's side (Y-axis negative side). The housing 110 has a driver-facing side wall portion 111 that extends to face the driver, and an outer peripheral wall portion 112 that extends toward the driver.

[0029] The driver-facing side wall portion 111 is a portion that forms the surface that faces the driver via the decorative cover 16. The driver-facing side wall portion 111 has a generally flat plate shape that is parallel to the board 160, and blocks the driver side (Y-axis negative side) of the internal space of the housing 110 from the board 160.

[0030] The outer peripheral wall 112 is a portion that surrounds the sides of the internal space of the housing 110. As shown in Fig. 6 , the outer peripheral wall 112 of the housing 110 has an upper wall 112a, a right wall 112b, and a lower wall 112c that are provided to surround the upper side (positive side of the Z axis), right side (positive side of the X axis), and lower side (negative side of the Z axis) of the driver-facing side wall 111. Portions of the upper wall 112a, the right wall 112b, and the lower wall 112c are provided to protrude toward the driver (negative side of the Y axis) beyond the surface of the driver-facing side wall 111 of the housing 110.

[0031] Additionally, the outer peripheral wall 112 of the housing 110 has an extension wall 112d that is provided to extend the outer peripheral wall 112. The extension wall 112d is a wall-like portion that extends obliquely downward (in the negative X-axis direction and the negative Z-axis direction) from the left end of the lower wall 112c of the outer peripheral wall 112 along the right side surface of the third portion 14C (see FIG. 1) of the spoke 14.

[0032] The internal space of the housing 110 is provided with a substrate 160 and the components of each of the multiple switches (such as a switch element 161 provided on the substrate 160, an actuator that links the operating knob 140 and the switch element 161, etc.).

[0033] The electrostatic detection unit 120 is a sheet-like sensor that is provided to electrostatically and non-contactly detect whether the driver's right hand is gripping the right grip portion 13R of the rim portion 13. The electrostatic detection unit 120 has an overall band-like shape. The electrostatic detection unit 120 is provided on the outer peripheral wall portion 112 of the housing 110.

[0034] Specifically, the electrostatic detection unit 120 is attached with double-sided tape or the like along the surfaces of the upper wall portion 112a, right wall portion 112b, lower wall portion 112c, and extension wall portion 112d of the outer peripheral wall portion 112 of the housing 110. As a result, the electrostatic detection unit 120 is disposed opposite the grip portion 13R of the rim portion 13 provided on the right side (positive direction of the X axis) of the housing 110, and can detect the fingers of the driver's right hand gripping the grip portion 13R in a non-contact manner.

[0035] The configuration of the sensor device 100R has been described above, but the configuration of the sensor device 100L is substantially symmetrical to the configuration of the sensor device 100R, and is basically the same as the configuration of the sensor device 100R.

[0036] The multiple operation knobs 140 are aligned on the driver-facing sidewall 111 of the housing 110 and are provided to be operable for input. The surface of each of the multiple operation knobs 140 is exposed from the opening 16A of the decorative cover 16 and serves as an operation surface 100A on which the driver performs various input operations. Each of the multiple operation knobs 140 is supported by the housing 110 so that the operation surface 100A faces the driver. Each of the multiple operation knobs 140 is provided to penetrate the driver-facing sidewall 111 while being movably supported by the housing 110, and when the driver performs an input operation, it can activate a switch element 161 provided on a substrate 160 via an actuator or the like.

[0037] Bottom case 150 is a resin member that closes the bottom side (positive side of the Y axis) of the internal space of housing 110. Bottom case 150 is detachably attached to housing 110 by screws or the like.

[0038] The substrate 160 is a flat, resin member provided in the internal space of the housing 110 and supported by the bottom case 150. A plurality of switch elements 161 are provided on the substrate 160 in correspondence with the plurality of operation knobs 140. The switch elements 161 are push switches, which are an example of an "input operation detection unit," and in this embodiment, detect a driver's pressing input operation on the operation knob 140. Note that in this embodiment, the bottom case 150 is a separate part from the housing 110, but the bottom case 150 and the housing 110 may be molded integrally.

[0039] 7 is a cross-sectional view schematically illustrating the layered structure of the electrostatic detection unit 120 included in the sensor device 100 according to one embodiment. As shown in Fig. 7, the electrostatic detection unit 120 has a layered structure in which, from the front surface side, a coverlay 121, a detection electrode 122, a base 123, an active shield electrode 124, and a coverlay 125 are layered.

[0040] The base 123 is a flexible, insulating sheet-like member that serves as the base of the electrostatic detection unit 120. In the example shown in Fig. 7, the base 123 has a configuration in which polyimide films 123b are attached to both sides of an intermediate material 123a such as silicone rubber with double-sided tape 123c.

[0041] The detection electrode 122 is formed on the surface of the base 123. The detection electrode 122 is provided to capacitively couple with the fingers of the driver's hand that are close to the detection electrode, and to detect the grip of the fingers of the driver's hand in a non-contact manner using a capacitive method.

[0042] The active shield electrode 124 is formed on the back surface of the base 123. The active shield electrode 124 is driven by a drive signal synchronized with the drive signal of the detection electrode 122, thereby making it possible to remove noise components that are applied to the detection electrode 122 from the back side of the detection electrode 122.

[0043] The detection electrode 122 and the active shield electrode 124 are made of a thin film conductor such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or a metal film (e.g., a composite material of silver, copper, aluminum, and molybdenum).

[0044] The coverlay 121 is a resin film-like member that is provided over the surface of the base 123 on which the detection electrodes 122 are formed. The coverlay 125 covers the surface of the base 123 to protect the surface of the base 123 and the detection electrodes 122.

[0045] The coverlay 125 is a resin film-like member that is provided on the back surface of the base 123 on which the active shield electrode 124 is formed. The coverlay 125 covers the back surface of the base 123, thereby protecting the back surface of the base 123 and the active shield electrode 124.

[0046] The electrostatic detection unit 120 having the above-described laminated structure has its back surface (the surface on the coverlay 125 side) attached to the surface of the outer peripheral wall 112 (the upper wall 112a, the right wall 112b, the lower wall 112c, and the extended wall 112d) of the housing 110. As a result, the electrostatic detection unit 120 is provided on the spokes 14 of the steering wheel 12 so that the detection electrode 122 and the active shield electrode 124 face the grip portion 13R of the rim 13. As a result, the electrostatic detection unit 120 is capacitively coupled with the fingers of the driver's hand gripping the grip portion 13R, and can detect changes in capacitance due to gripping in a non-contact manner using the detection electrode 122. At this time, the active shield electrode 124 of the electrostatic detection unit 120 can remove noise components applied to the detection electrode 122 from the housing 110 side behind the electrostatic detection unit 120.

[0047] (Configuration of control system provided in sensor device 100) Fig. 8 is a diagram showing the configuration of a control system provided in sensor device 100 according to one embodiment. As shown in Fig. 8, the control system provided in sensor device 100 includes the detection electrode 122 and active shield electrode 124 already described, and a control device 130. Note that the configuration of the control system of sensor device 100 shown in Fig. 8 is common to sensor devices 100L and 100R.

[0048] The control device 130 is a device that can determine whether or not the driver's fingers are gripping the rim portion 13 (grip portions 13L, 13R) of the steering wheel 12 based on the detection results from the detection electrode 122, and output the determination result.

[0049] 8, the control device 130 is electrically connected to each of the detection electrode 122 and the active shield electrode 124. The control device 130 includes a detection electrode control unit 131, a shield electrode control unit 132, a determination unit 133, and a result output unit 134.

[0050] The detection electrode control unit 131 detects a change in capacitance in the detection electrode 122. Specifically, the detection electrode control unit 131 drives the detection electrode 122 by applying an AC voltage consisting of a sine wave as a drive signal to the detection electrode 122. Then, the detection electrode 122 detects a change in the current value of the current flowing through the detection electrode 122 as a change in capacitance.

[0051] For example, the detection electrode 122 of the sensor device 100R is provided near the grip portion 13R, facing the grip portion 13R. Therefore, when the fingers of the driver's right hand grip the grip portion 13R, the fingers of the driver's right hand are located close to the detection electrode 122 of the sensor device 100R. As a result, the detection electrode 122 of the sensor device 100R is capacitively coupled with the fingers of the driver's right hand, and the current value of the current flowing through the detection electrode 122 changes. This allows the detection electrode 122 of the sensor device 100R to detect (non-contact detection) the fingers of the driver's right hand.

[0052] As shown in Figures 5 and 6, the electrostatic detection unit 120 of the sensor device 100R has a shape that is bent at approximately right angles at the upper right corner and the lower right corner of the housing 110, so that it can detect the fingers of the driver's right hand within a range of approximately ±30° at the grip portion 13R, based on the 90° position (positive side of the X-axis) of the rim portion 13.

[0053] The shield electrode control unit 132 generates an active shield signal and outputs the active shield signal to the active shield electrode 124. In this way, the shield electrode control unit 132 drives the active shield electrode 124. The active shield signal is, for example, a signal (i.e., an AC voltage consisting of a sine wave) having a waveform synchronized with the drive signal applied to the detection electrode 122 from the detection electrode control unit 131. When the active shield electrode 124 is driven, it can remove noise components applied to the detection electrode 122 from the back side (the housing 110 side) of the active shield electrode 124. In other words, the active shield electrode 124 can remove noise components from the capacitance detected by the detection electrode 122.

[0054] The determination unit 133 determines whether or not the driver's fingers are gripping the grip portions 13L and 13R based on the change in capacitance in the detection electrodes 122 detected by the detection electrode control unit 131.

[0055] For example, if the difference value between the reference value of the capacitance of the detection electrode 122 provided in the sensor device 100R exceeds a predetermined threshold value th, the judgment unit 133 judges that the fingers of the driver's right hand are gripping the grip portion 13R.

[0056] Conversely, if the difference value between the reference value of the capacitance of the detection electrode 122 provided in the sensor device 100R is less than a predetermined threshold value th, the judgment unit 133 determines that there are no fingers on the driver's right hand gripping the grip portion 13R.

[0057] The reference value is a value set assuming a capacitance value when the driver's finger or the like is not in proximity.

[0058] The threshold value th is set to a suitable value determined in advance by actual device testing, simulation, or the like. As described above, the control device 130 drives the active shield electrode 124, and therefore the capacitance detected by the detection electrode 122 is one from which noise components from the back side (housing 110 side) of the detection electrode 122 have been removed. For this reason, in this embodiment, the threshold value th is set to a value from which noise components from the back side (housing 110 side) of the detection electrode 122 have been removed by the active shield electrode 124, and therefore the threshold value th is lower than that of a conventional configuration that does not use an active shield electrode.

[0059] The result output unit 134 outputs the judgment result by the judgment unit 133 (i.e., whether or not the driver's fingers are gripping the gripping portions 13L, 13R) to the outside (for example, a device that executes processing according to the judgment result by the judgment unit 133).

[0060] The control device 130 is realized by, for example, a computer (for example, an integrated circuit (IC)) equipped with a processor (for example, a CPU), a storage medium (for example, a read-only memory (ROM), a random access memory (RAM), a solid-state drive (SSD), etc.), an external interface, etc. For example, the control processing in each functional unit of the control device 130 shown in FIG. 8 is realized by the processor executing a program stored in a storage medium in the control device 130.

[0061] (Waterproof structure of housing 110) Fig. 9 is a partially enlarged perspective view of sensor device 100R according to one embodiment. Fig. 10 is a plan view of sensor device 100R according to one embodiment as viewed from the driver's side. Fig. 11 is a partially enlarged perspective view of sensor device 100R according to one embodiment (with multiple operation knobs 140 removed). Fig. 12 is a plan view of sensor device 100R according to one embodiment (with multiple operation knobs 140 removed) as viewed from the driver's side.

[0062] In one embodiment of the sensor device 100R, the housing 110 has a "control wall" (such as the driver-facing side wall portion 111 described below) that prevents water that has entered from around the operating knob 140 at the opening 16A of the decorative cover 16 from reaching either the detection electrode 122 or the substrate 160 when the sensor device 100R becomes wet, whether the steering wheel 12 is in its initial state or when it is rotated in any direction.

[0063] The "restriction wall" prevents water from flowing further into the detection electrode 122 and the substrate 160 when the sensor device 100R is submerged in water, regardless of the rotation state of the steering wheel 12. This prevents the detection electrode 122 and the substrate 160 from getting wet. Therefore, according to the sensor device 100R of the embodiment, even when the sensor device 100R is submerged in water, the detection electrode 122 can reliably detect the gripping state, and the substrate 160 can reliably detect an input operation using the operation knob 140.

[0064] As shown in FIGS. 9 to 12 , in the sensor device 100R according to one embodiment, the housing 110 includes a driver-facing sidewall 111. The driver-facing sidewall 111 is an example of a "first restriction wall" included in the "restriction wall." The driver-facing sidewall 111 is provided on the driver's side in the internal space of the housing 110, parallel to the substrate 160. In other words, the driver-facing sidewall 111 is a flat wall that covers the driver's side relative to the substrate 160 in the internal space of the housing 110, blocking the opening of the internal space to prevent water from flowing away from the driver's side.

[0065] As a result, in one embodiment of the sensor device 100R, the driver-facing side wall portion 111 can prevent water that has entered from around the operating knob 140 at the opening 16A of the decorative cover 16 from entering the internal space of the housing 110, thereby preventing the substrate 160 provided inside the housing 110 from becoming wet.

[0066] 2, 11, and 12, a plurality of through holes 111A are formed in the driver-facing side wall portion 111. Each of the plurality of through holes 111A supports the operation knob 140 so that it can move up and down, and is provided so that the operation knob 140 and an actuator (not shown) can be inserted into the housing 110, and the actuator can press a switch element 161 provided on the substrate 160 in response to an input operation of the operation knob 140.

[0067] Each of the plurality of through holes 111A has a cylindrical wall portion 111B surrounding the through hole 111A. When viewed from the driver's side, the through hole 111A and the wall portion 111B are entirely covered by the operation knob 140 (they are provided inside the outer periphery of the operation knob 140), and the wall portion 111B is provided to protrude toward the driver further than the surface of the driver-facing side wall portion 111. As a result, the wall portion 111B can prevent water that has entered from around the operation knob 140 at the opening 16A and fallen on the surface of the driver-facing side wall portion 111 from entering the interior of the housing 110 through the through hole 111A, thereby preventing the substrate 160 provided inside the housing 110 from becoming wet.

[0068] 2, 11, and 12, in the sensor device 100R according to one embodiment, the housing 110 includes a second restriction wall 113 extending from the driver-facing side wall 111 (first restriction wall) toward the driver between the operation knob 140 and the detection electrode 122 (electrostatic detection unit 120). The second restriction wall 113 is an example of a "second restriction wall" included in the "restriction wall." The second restriction wall 113 restricts the flow of water toward the detection electrode 122 (electrostatic detection unit 120) and extends continuously between the opening 16A and the detection electrode 122 (electrostatic detection unit 120).

[0069] As a result, in one embodiment of the sensor device 100R, water that has been wetted from around the operating knob 140 at the opening 16A and flows along the surface of the driver-facing side wall 111 can be confined to the area inside the second regulating wall 113 by the second regulating wall 113, preventing the water from flowing out to an area outside the second regulating wall 113, and therefore preventing the detection electrode 122, which is provided in an area outside the second regulating wall 113, from being wetted.

[0070] In particular, the second restriction wall 113 (see the area surrounded by the dashed lines in FIGS. 11 and 12 ) is provided continuously without any gaps along the detection electrode 122 (electrostatic detection unit 120). That is, since the electrostatic detection unit 120 is provided along the outer peripheral wall 112 of the housing 110 (the upper wall 112 a, the right wall 112 b, the lower wall 112 c, and the extension wall 112 d), the second restriction wall 113 is provided substantially along the outer peripheral wall 112 of the housing 110.

[0071] As a result, in one embodiment of the sensor device 100R, the second restricting wall 113 can reliably prevent water that has fallen into the area inside the second restricting wall 113 on the surface of the driver-facing side wall 111 from flowing out to the area outside the second restricting wall 113 from around the operating knob 140 at the opening 16A, and therefore the detection electrode 122 provided in the area outside the second restricting wall 113 can be reliably prevented from falling into the water.

[0072] Furthermore, the second restricting wall 113 is provided seamlessly so as to surround the driver-facing side wall 111 in three directions (i.e., the three directions in the positive Z-axis direction, the negative Z-axis direction, and the positive X-axis direction when the steering wheel on which the electrostatic detection unit 120 is provided is viewed from the driver's side in plan view). Therefore, regardless of whether the steering wheel 12 is in an initial state or is rotated in any direction, when the surface of the driver-facing side wall 111 becomes wet, the second restricting wall 113 can restrict the flow of water flowing over the surface of the driver-facing side wall 111 due to gravity at the position of the second restricting wall 113, thereby reliably preventing the electrostatic detection unit 120 from becoming wet.

[0073] In this embodiment, the second restricting wall 113 includes a portion of the upper wall portion 112a of the outer peripheral wall portion 112 and a portion of the lower wall portion 112c of the outer peripheral wall portion 112. However, this is not limited thereto, and for example, the second restricting wall 113 may be formed only by the outer peripheral wall portion 112, or may be provided separately from the outer peripheral wall portion 112 without including the outer peripheral wall portion 112. In other words, the second restricting wall 113 does not necessarily need to be adjacent to the outer peripheral wall portion 112, and can be provided in any region between the operation knob 140 and the detection electrode 122 to prevent the detection electrode 122 from becoming wet.

[0074] In addition, in one embodiment of the sensor device 100R, the housing 110 has a ``drainage channel'' (for example, a first drainage channel 115 and a second drainage channel 118) that discharges water that has entered from around the operating knob 140 in a direction away from the detection electrode 122 and the substrate 160 when the sensor device 100R is submerged in water.

[0075] As a result, sensor device 100R according to one embodiment can use the "drainage channel" to guide water that has splashed on driver-facing side wall portion 111 in a direction away from detection electrode 122 and substrate 160, and discharge it to the outside of sensor device 100R. As a result, sensor device 100R according to one embodiment can suppress water from accumulating inside the device, and can prevent the water from capacitively coupling with detection electrode 122, which could result in erroneous detection of the driver's grip.

[0076] Here, as shown by the arrows in FIGS. 11 and 12, the “drainage channels” of the housing 110 include, for example, a first drainage channel 115 and a second drainage channel 118 .

[0077] Here, as shown in Figures 11 and 12, in one embodiment of the sensor device 100R, the "drainage channel" of the housing 110 includes a first drainage channel 115 that extends from around the operating knob 140 toward the hub portion 15 (see Figure 1).

[0078] As a result, when the sensor device 100R of one embodiment becomes wet, the water that has entered from around the operating knob 140 can be easily discharged through the first drainage channel 115 toward the hub portion 15 (i.e., toward the center of the steering wheel 12, which is the direction in which the detection electrode 122 and the substrate 160 are not located).

[0079] In particular, in the sensor device 100R according to one embodiment, the first drainage channel 115 has a plurality of ribs 115A that extend at an angle toward the hub portion 15 and the direction of gravity in the initial state of the steering wheel 12. Each of the plurality of ribs 115A has a wall shape that protrudes toward the driver from the surface of the driver-facing side wall portion 111.

[0080] As a result, the sensor device 100R of one embodiment can weaken the flow rate of water in the direction of gravity by abutting water that has entered around the operating knob 140 against the rib 115A, and further, can distribute and direct water that has entered around the operating knob 140 along the rib 115A so that it can be reliably discharged in predetermined amounts toward the hub portion 15 (i.e., toward the center of the steering wheel 12).

[0081] 11 and 12 , in sensor device 100R according to one embodiment, housing 110 has through-hole 116 that penetrates housing 110 from the driver's side to the rear side in an area near connection 17 (see FIGS. 1, 3, and 4) between spoke portion 14 and rim portion 13. In sensor device 100R according to one embodiment, housing 110 also has second drainage channel 118 that drains water that has entered from around operation knob 140 to the rear side of housing 110 via through-hole 116.

[0082] Specifically, the through-hole 116 is provided in the lower right corner of the driver-facing side wall 111 in an area that does not overlap with the substrate 160 as viewed from the driver. That is, the through-hole 116 is provided so as to penetrate the area between the substrate 160 of the housing 110 and the detection electrode 122. Meanwhile, the lower wall 112c of the housing 110 is inclined downward to the right with respect to a horizontal plane that is level with the ground (a horizontal plane parallel to the X-axis) when the steering device 10 is in the neutral steering position. Therefore, water that enters from around the operation knob 140 and splashes onto the surface of the driver-facing side wall 111 flows toward the lower wall 112c due to gravity, and further flows along the lower wall 112c toward the through-hole 116, which is provided at the most downstream position of the second drainage channel 118 (i.e., the most downstream position in the direction of gravity).

[0083] As a result, when sensor device 100R according to one embodiment is submerged in water, water that has entered around operation knob 140 can flow downstream in second drainage channel 118 due to gravity on the surface of driver-facing side wall 111. Sensor device 100R according to one embodiment can then discharge the water that flows downstream in second drainage channel 118 due to gravity from through-hole 116 formed at the most downstream position of second drainage channel 118 to the back side of housing 110 (positive side of the Y axis) without contacting either substrate 160 or detection electrode 122.

[0084] Because sensor device 100R according to one embodiment has outer peripheral wall 112 on three sides of driver-facing side wall 111, depending on the rotation state of steering wheel 12, when sensor device 100R is exposed to water, water that enters around operation knob 140 may be received from three directions by outer peripheral wall 112 and accumulate in the lower right corner of driver-facing side wall 111, which is the lower corner in the direction of gravity (see FIG. 14 ). However, in sensor device 100R according to one embodiment, because housing 110 has through-hole 116 in the lower right corner of driver-facing side wall 111, water that enters around operation knob 140 can be discharged through through-hole 116 to the rear side of housing 110 (positive side of the Y axis). Therefore, regardless of the rotation state of steering wheel 12, water can be prevented from accumulating in the lower right corner of driver-facing side wall 111.

[0085] Furthermore, for example, if water flowing through the second drainage channel 118 remains on the inner wall of the through hole 116 or in its vicinity, the water may become capacitively coupled to the detection electrode 122, and the electrostatic capacitance detected by the detection electrode 122 may contain noise components.

[0086] Therefore, the sensor device 100R according to one embodiment includes an active shield electrode 124 (see FIGS. 7 and 13) provided in a region near the through-hole 116 on the outer circumferential surface of the housing 110.

[0087] As a result, in one embodiment of the sensor device 100R, the active shield electrode 124 can block the capacitive coupling of water to the detection electrode 122 even if water remains on the inner wall of or near the through hole 116.

[0088] 13 is a diagram showing drainage paths in the sensor device 100R when the steering wheel 12 is in the initial state. As shown in FIG. 13 , if the sensor device 100R is submerged in water when the steering wheel 12 is in the initial state, the sensor device 100R receives water from around the operation knob 140 by gravity using the plurality of ribs 115A that are located on the lower side in the direction of gravity (Z-axis direction) and the lower wall portion 112c of the outer peripheral wall portion 112. The water is then drained toward the hub portion 15 (i.e., toward the center of the steering wheel 12 where the detection electrode 122 and the substrate 160 are not provided) through the plurality of first drainage channels 115 provided along the plurality of ribs 115A. The second drainage channels 118 provided along the lower wall portion 112c allow the water to be drained from the through-holes 116 to the rear side of the housing 110 (the positive side of the Y-axis) without coming into contact with the detection electrode 122 and the substrate 160.

[0089] 14 is a diagram showing the drainage path in the sensor device 100R when the steering wheel 12 is rotated 90° clockwise. As shown in FIG. 14 , if the sensor device 100R is submerged in water when the steering wheel 12 is rotated 90° clockwise, the sensor device 100R can drain water from around the operation knob 140 through the second drainage path 118 extending in the direction of gravity (X-axis direction) along the lower wall portion 112c of the outer peripheral wall portion 112, and from the through-hole 116 located below in the direction of gravity (X-axis direction) to the back side of the housing 110 (positive side of the Y-axis) without contacting the detection electrode 122 and the substrate 160.

[0090] 15 is a diagram showing the drainage path in the sensor device 100R when the steering wheel 12 is rotated 180° clockwise. As shown in FIG. 15, if the sensor device 100R is submerged in water when the steering wheel 12 is rotated 180° clockwise, the sensor device 100R receives water from around the operation knob 140 by gravity using the upper wall portion 112a of the outer peripheral wall portion 112, which is on the lower side in the direction of gravity (Z-axis direction), and can drain the water toward the hub portion 15 (i.e., toward the center of the steering wheel 12, where the detection electrode 122 and the substrate 160 are not provided) through the first drainage path 115 provided along the upper wall portion 112a.

[0091] 16 is a diagram showing the drainage paths in the sensor device 100R when the steering wheel 12 is rotated 270° clockwise. As shown in FIG. 16, if the sensor device 100R is submerged in water when the steering wheel 12 is rotated 270° clockwise, the sensor device 100R can drain water from around the operation knob 140 in accordance with gravity toward the hub portion 15 (i.e., toward the center of the steering wheel 12 where the detection electrode 122 and the substrate 160 are not provided) through the multiple first drainage paths 115 that extend in the gravity direction (X-axis direction) along the multiple ribs 115A.

[0092] As described above, in one embodiment of the sensor device 100R, when the sensor device 100R becomes wet, regardless of the rotation state of the steering wheel 12, the water can be reliably discharged from around the operating knob 140 to the outside of the sensor device 100R via the first drainage channel 115, the second drainage channel 118, and the through hole 116, thereby preventing the detection electrode 122 and the substrate 160 from getting wet.

[0093] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0094] This international application claims priority based on Japanese Patent Application No. 2023-222685, filed on December 28, 2023, the entire contents of which are incorporated herein by reference.

[0095] 10 Steering device 12 Steering wheel 13 Rim portion 13L Grip portion 13R Grip portion 14 Spoke portion 14A First portion 14B Second portion 14C Third portion 15 Hub portion 15A Through hole 16 Decorative cover 16A Opening 17 Connection portion 100, 100L, 100R Sensor device 100A Operation surface 110 Housing 111 Driver-facing side wall portion (restriction wall / first restriction wall) 112 Outer peripheral wall portion 112a Upper wall portion 112b Right wall portion 112c Lower wall portion 112d Extension wall portion 113 Second restriction wall (restriction wall) 115 First drainage channel (drainage channel) 115A Rib 116 Through hole 118 Second drainage channel (drainage channel) 120 Electrostatic detection unit 121 Coverlay 122 Detection electrode 123 Base 123a Intermediate material 123b Polyimide film 123c Double-sided tape 124 Active shield electrode 125 Coverlay 130 Control device 131 Detection electrode control unit 132 Shield electrode control unit 133 Determination unit 134 Result output unit 140 Operation knob 150 Bottom case 160 Substrate 161 Switch element (input operation detection unit) th Threshold value

Claims

1. A sensor device mounted on the spoke portion of a steering wheel having a rim portion gripped by a driver, a hub portion disposed at the center of the rim portion, and a spoke portion extending from the hub portion to support the rim portion, and covered with a decorative cover having an opening, the sensor device comprising: a housing; a detection electrode provided on an outer peripheral surface of the housing to face the rim portion and detecting a capacitance by capacitive coupling with the hand of the driver gripping the rim portion; an operation knob having an operation surface exposed from the opening of the decorative cover and disposed so that the operation surface faces the driver; a substrate provided in an internal space of the housing; and an input operation detection unit provided on the substrate and detecting an input operation by the driver to the operation knob, wherein the housing has a regulation wall that regulates water entering from around the operation knob at the opening of the decorative cover from reaching any of the detection electrode and the substrate when the sensor device is waterlogged, in any of an initial state of the steering wheel and a state where the steering wheel is rotated in an arbitrary direction.

2. The sensor device according to claim 1, wherein the regulation wall includes: a first regulation wall provided to close the driver side with respect to the substrate in the internal space of the housing and constituting a surface facing the driver; and a second regulation wall erected from the first regulation wall toward the driver side between the operation knob and the detection electrode.

3. The sensor device according to claim 2, wherein the second regulation wall is provided continuously along the detection electrode without a break in the middle.

4. The sensor device according to claim 3, wherein the housing has a drainage path that discharges water entering from around the operation knob at the opening of the decorative cover in a direction where the detection electrode and the substrate are not present when the sensor device is waterlogged.

5. The sensor device according to claim 4, wherein the drainage path includes a first drainage path extending from around the operation knob toward the hub portion.

6. The sensor device according to claim 5, wherein the first drainage path has ribs that are inclined in the direction of gravity and the hub portion in the initial state of the steering wheel.

7. The housing has a through-hole that penetrates the housing from the driver side to the back side in a region near the connection portion between the spoke portion and the rim portion, and the drainage channel includes a second drainage channel that drains water that has entered from around the operation knob at the opening of the decorative cover to the back side of the housing through the through-hole. The sensor device according to claim 4, characterized in that.

8. The sensor device according to claim 7, further comprising an active shield electrode provided in a region near the through-hole on the outer peripheral surface of the housing.

9. The sensor device according to claim 1, further comprising a determination unit that determines the gripping of the rim portion by the driver based on the change in capacitance detected by the detection electrode.

10. A steering device, comprising: the steering wheel; and the sensor device according to any one of claims 1 to 9 mounted on the steering wheel.

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