Electrode structure, steering wheel, and method of manufacturing steering wheel

Abstract

To provide an electrode structure, a steering wheel and a manufacturing method of the steering wheel that suppress sharp rises in manufacturing costs of a steering wheel, while securing exterior appearance of the steering wheel.SOLUTION: An electrode structure 20 is disposed in a steering wheel 1 provided in a vehicle 3. The electrode structure 20 comprises: an insulator 21; a first electrode 31 disposed on a first surface 21a of the insulator 21 that is a surface facing a metal core 11 of the steering wheel 1; a second electrode 32 disposed on a second surface 21b that is a surface on the opposite side of the first surface 21a of the insulator 21; a projection part 23 projecting from the insulator 21 toward the metal core 11; and an engaging part 22 engaging with the metal core 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an electrode structure, a steering wheel, and a method for manufacturing a steering wheel. [Background technology]

[0002] Conventionally, a method has been disclosed in which a cutting tool is used to make cuts in a foam material of a steering wheel, and conductors of a sensor are introduced into each of a first layer and a second layer of the cuts (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 145868 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the cuts in the foam of the steering wheel can degrade the appearance of the steering wheel, and the increased man-hours required for cutting and for introducing the conductors of the sensor can increase the manufacturing cost of the steering wheel.

[0005] Therefore, the present disclosure provides an electrode structure, a steering wheel, and a method for manufacturing a steering wheel that can suppress an increase in the manufacturing costs of the steering wheel while ensuring the appearance of the steering wheel. [Means for solving the problem]

[0006] An electrode structure according to one embodiment of the present disclosure is an electrode structure arranged on a steering wheel provided on a vehicle, and includes an insulator, a first electrode arranged on a first surface of the insulator which is the surface facing a core metal of the steering wheel, a second electrode arranged on a second surface of the insulator which is the surface opposite to the first surface, a protrusion protruding from the insulator toward the core metal, and a hooking portion hooking onto the core metal.

[0007] These comprehensive or specific aspects may be realized by a system, an apparatus, a method, a recording medium, or a computer program, or may be realized by any combination of a system, an apparatus, a method, a recording medium, and a computer program. Effect of the Invention

[0008] The electrode structure etc. of the present disclosure can suppress an increase in the manufacturing costs of the steering wheel while ensuring the appearance of the steering wheel. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a vehicle interior in which a steering wheel according to an embodiment is arranged. [Diagram 2] FIG. 2 is a cross-sectional view showing the steering wheel of the embodiment taken along line II-II in FIG. [Diagram 3] FIG. 3 is a cross-sectional perspective view showing the steering wheel in the embodiment. [Figure 4] FIG. 4 is a block diagram showing a steering wheel according to the embodiment. [Diagram 5] FIG. 5 is a flowchart showing a method for manufacturing a steering wheel according to an embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a steering wheel in the first modification of the embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a steering wheel in the second modification of the embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a steering wheel in a third modified example of the embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a steering wheel in a fourth modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An electrode structure according to one embodiment of the present disclosure is an electrode structure arranged on a steering wheel provided on a vehicle, and includes an insulator, a first electrode arranged on a first surface of the insulator which is the surface facing a core metal of the steering wheel, a second electrode arranged on a second surface of the insulator which is the surface opposite to the first surface, a protrusion protruding from the insulator toward the core metal, and a hooking portion hooking onto the core metal.

[0011] According to this, the electrode structure can be attached to the core bar in advance. This allows the electrode structure to be disposed inside the steering wheel when the steering wheel is formed. This eliminates the need to form the steering wheel, then cut the steering wheel to dispose the first and second electrodes, as in the conventional method. This makes it difficult for the appearance of the steering wheel to deteriorate and for the man-hours involved in manufacturing the steering wheel to increase.

[0012] Therefore, the electrode structure can suppress an increase in the manufacturing costs of the steering wheel while ensuring the appearance of the steering wheel.

[0013] In particular, in this electrode structure, the protrusion protruding from the insulator toward the core and the engagement portion engaging with the core can ensure the posture of the first electrode and the insulator relative to the core. Therefore, the protrusion and the engagement portion can prevent the first electrode and the core from being electrically connected. As a result, when the electrode structure is used to detect gripping of a steering wheel, it can accurately detect that the driver's hands are gripping the steering wheel.

[0014] Furthermore, since the protrusion and the engaging portion can ensure the orientation of the first electrode and the insulator relative to the core metal, the electrode structure can be reliably incorporated into the steering wheel when the steering wheel is molded from resin.

[0015] Furthermore, the protrusion can maintain the distance between the core metal and the first electrode, and the engaging portion can engage the insulator with the core metal, thereby fixing the insulator to the core metal. This makes it possible to prevent the insulator from shifting in position relative to the core metal or rotating in the circumferential direction of the steering wheel due to pressure during resin molding of the steering wheel.

[0016] Moreover, an electrode structure according to one embodiment of the present disclosure is an electrode structure arranged on a steering wheel provided on a vehicle, and includes an insulator made of hard plastic, a first electrode arranged on a first surface of the insulator which is a surface facing a core metal of the steering wheel, and a second electrode arranged on a second surface of the insulator which is a surface opposite to the first surface.

[0017] In this electrode structure, the insulator on which the first and second electrodes are arranged is also made of hard plastic, so that, for example, the electrode structure can be attached to the core in advance while ensuring the orientation of the first electrode and the insulator relative to the core, thereby achieving the same effects as those described above.

[0018] A steering wheel according to one aspect of the present disclosure includes an electrode structure, the core metal, and a foam covering the electrode structure.

[0019] This steering wheel also provides the same effects as those described above.

[0020] In addition, a method for manufacturing a steering wheel according to one aspect of the present disclosure includes engaging the engaging portion of an electrode structure with the core metal, and covering the electrode structure with a foam while the engaging portion is engaged with the core metal.

[0021] This method of manufacturing a steering wheel also provides the same effects as those described above.

[0022] In the electrode structure, the engaging portion has a second recess that engages with a first recess formed in the core metal.

[0023] According to this, the first recess and the second recess engage with each other, and the engaging portion can fix the insulator to the core metal, which can prevent the insulator from being displaced relative to the core metal or from being rotated in the circumferential direction of the steering wheel due to pressure applied during resin molding of the steering wheel.

[0024] In addition, in the electrode structure, in a cross section of the steering wheel cut along a plane perpendicular to the circumferential direction of the steering wheel, the protrusion and the engaging portion sandwich the core metal, and the protrusion and the engaging portion are positioned opposite each other.

[0025] According to this, the hook portion can support the insulator at a position corresponding to the position where the protrusion supports the insulator, and therefore the protrusion and the hook portion can be arranged to space the first electrode and the insulator away from the core metal so that the first electrode does not contact the core metal.

[0026] Furthermore, when forming the steering wheel, a space in which the foam can be filled can be secured between the first electrode and the insulator, making it possible to resin-molde the foam between the first electrode and the insulator.

[0027] In addition, it is possible to further prevent the insulator from being displaced relative to the core metal or from being rotated in the circumferential direction of the steering wheel due to pressure caused during resin molding of the steering wheel.

[0028] In addition, in the electrode structure, the core metal has a curved portion in a cross section when the steering wheel is cut along a plane perpendicular to the circumferential direction of the steering wheel, and the protrusion is positioned at a position opposite the curved portion.

[0029] With this, even if the core has a curved portion, the protrusion can be arranged to space the first electrode and the insulator away from the curved portion so that the first electrode does not come into contact with the core.

[0030] In the electrode structure, the protrusion and the engagement portion are formed integrally with the insulator.

[0031] This makes it possible to suppress the increase in the number of steps, such as bonding the protrusions and the engagement portions to the insulator.

[0032] In addition, in the electrode structure, the insulator, the first electrode, and the second electrode are arranged in a range from at least the outer periphery of the steering wheel to the rear side of the vehicle in a cross section of the steering wheel cut by a plane perpendicular to the circumferential direction of the steering wheel.

[0033] According to this, when the driver grips the steering wheel, the electrode structure can be disposed at a position where the driver's hands are likely to come into contact with the surface of the steering wheel, so that gripping by the driver's hands can be reliably detected.

[0034] Furthermore, since there is no need to arrange the electrode structure over the entire steering wheel, it is possible to suppress an increase in material costs for the electrode structure.

[0035] In the electrode structure, the protruding portion and the engaging portion each have a curved surface portion in which corners of the contour of the protruding portion and the engaging portion are rounded.

[0036] According to this, when manufacturing the steering wheel, for example, when filling the foam so as to cover the core metal, the insulator, the first electrode, and the second electrode, the foam can be made to flow, so that the foam can be reliably filled around the protrusion and the engagement portion.

[0037] In the electrode structure, the insulator is made of a resin material, the first electrode is made of metal plating, a metal sheet, or a metal plate, and the second electrode is made of metal plating, a metal sheet, or a metal plate.

[0038] According to this, the insulator can be formed using a resin material according to the shape and size of the core. Also, since the first electrode and the second electrode can be arranged on the insulator, the member in which the insulator, the first electrode, and the second electrode are integrated can be easily assembled to the core. Furthermore, if the insulator has a certain strength, the insulator can arrange the first electrode in a state where the first electrode is separated from the core.

[0039] In the electrode structure, an AC voltage having the same phase as an AC voltage applied to the second electrode is applied to the first electrode.

[0040] This can cancel or reduce the capacitance between the first electrode and the second electrode, so that by using a control circuit that detects the driver's gripping of the steering wheel with his / her hands, the control circuit can accurately detect the change in capacitance between the second electrode and the driver's hands that occurs when the driver's hands grip the steering wheel.

[0041] In the electrode structure, the core metal has an annular shape, and the insulator has a shape disposed along an outer peripheral surface of the core metal.

[0042] This allows the insulator to be disposed in accordance with the outer shape of the core metal, thereby enhancing the versatility of the electrode structure.

[0043] In the electrode structure, the first electrode is made of a metal plating, a metal sheet, or a metal plate, and the second electrode is made of a metal plating, a metal sheet, or a metal plate.

[0044] According to this, since the first electrode and the second electrode can be arranged on the insulator, the member in which the insulator, the first electrode, and the second electrode are integrated can be easily assembled to the core metal. Furthermore, if the insulator has a certain strength, the insulator can arrange the first electrode in a state where the first electrode is separated from the core metal.

[0045] Hereinafter, the embodiment will be specifically described with reference to the drawings.

[0046] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component arrangement and connection forms, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, among the components in the following embodiments, components that are not described in an independent claim showing a top concept are described as optional components.

[0047] In addition, each drawing is a schematic diagram and is not necessarily a precise illustration. In addition, in each drawing, the same components are denoted by the same reference numerals.

[0048] In the following embodiments, expressions such as "approximately equal intervals" or "T-shaped" are used. For example, "approximately equal intervals" or "T-shaped" does not only mean that the intervals are completely equal or that the shape is T-shaped, but also means that the intervals are substantially equal or that the shape is T-shaped, that is, includes an error of about several percent. Furthermore, "approximately equal intervals" or "T-shaped" means that the intervals are equal or that the shape is T-shaped within the range in which the effects of the present disclosure can be achieved. The same applies to other expressions using "approximately" or "shaped."

[0049] (Embodiment) <Components: 1 steering wheel> FIG. 1 is a diagram showing a cabin of a vehicle 3 in which a steering wheel 1 according to an embodiment is arranged.

[0050] As shown in FIG. 1, a steering wheel 1 can provide a steering angle to the steered wheels of a vehicle 3, for example.

[0051] The steering wheel 1 has a rim 10. The rim 10 is integrally formed with T-shaped spokes 9 arranged on the inner circumferential surface of the rim 10.

[0052] As shown in Figures 2 and 3, the rim 10 includes a core metal 11, an electrode structure 20, and a foam 12 covering the electrode structure 20. Here, Figure 2 is a cross-sectional view showing the steering wheel 1 of the embodiment taken along line II-II in Figure 1. Figure 3 is a cross-sectional perspective view showing the steering wheel 1 of the embodiment. In Figure 3, the contour of the foam 12 is indicated by a dashed line.

[0053] [Core wire 11] The core 11 is a metal annular core. Specifically, the core 11 has an annular first portion 11a and an annular second portion 11b arranged on the outer circumferential side of the first portion 11a. One end edge of the first portion 11a and one end edge of the second portion 11b are connected to each other. In other words, the cross section of the core 11 when the core 11 is cut along a plane perpendicular to the circumferential direction of the core 11 (hereinafter sometimes referred to as the cross section of the core 11) has a U-shape, V-shape, J-shape, C-shape, or the like.

[0054] In addition, since the cross section of the core metal 11 is U-shaped, V-shaped, J-shaped, C-shaped, or the like, a first recess 10a is formed between the first portion 11a and the second portion 11b. The first recess 10a is a recess having a circular ring shape. In this embodiment, the first recess 10a is formed on the front side of the rim 10 with respect to the vehicle 3 (the side opposite the seat side with respect to the rim 10).

[0055] Moreover, the core metal 11 has a curved portion 13. Specifically, the curved portion 13 is a surface on the outer circumferential side of the core metal 11 in a cross section of the core metal 11, and is formed at a connection portion between the first portion 11a and the second portion 11b.

[0056] [Electrode structure 20] The electrode structure 20 is used in a device that detects the grip of the steering wheel 1 by the driver's hand. Specifically, the electrode structure 20 is connected to a control circuit 40 that can detect the grip of the steering wheel 1 by the driver's hand. When the driver's hand grips the rim 10, the capacitance between the electrode of the electrode structure 20 and the hand changes. The control circuit 40 detects the grip based on an output signal from the electrode of the electrode structure 20 indicating the change in capacitance. Specifically, the control circuit 40 measures the capacitance of the electrode or a value (amount of change) corresponding to the capacitance, and detects the grip of the rim 10 by the driver's hand based on the value. Such a control circuit 40 is composed of a dedicated circuit or a general-purpose processor. Also, the control circuit 40 is embedded in, for example, the spoke 9 of FIG. 1.

[0057] The electrode structure 20 is disposed in a steering wheel 1 provided in a vehicle 3. In this embodiment, the electrode structure 20 is embedded in a rim 10 of the steering wheel 1. Specifically, the electrode structure 20 includes an insulator 21, a hooking portion 22, a protruding portion 23, a first electrode 31, and a second electrode 32.

[0058] The insulator 21 has a circular ring shape similar to that of the core 11, and is disposed along the outer peripheral surface of the core 11 so as to be concentric with the core 11. In other words, the insulator 21 has a larger diameter than the core 11.

[0059] A first electrode 31 is disposed on a first surface 21a of the insulator 21 that faces the core metal 11, and a second electrode 32 is disposed on a second surface 21b of the insulator 21 that is the surface opposite to the first surface 21a. The insulator 21 can be disposed such that the first electrode 31 and the second electrode 32 overlap each other so that they are not electrically connected to each other. The insulator 21 is made of a resin material such as a hard plastic, for example, polycarbonate or polybutylene terephthalate.

[0060] Moreover, the insulator 21 has a constant thickness. For example, the constant thickness of the insulator 21 is about several mm. Since the insulator 21 has a constant thickness, rigidity is ensured. Therefore, when the steering wheel 1 is molded from resin, the insulator 21 is unlikely to deform and can maintain its posture.

[0061] Moreover, the insulator 21 is supported by the engaging portion 22, and is disposed in a state spaced a predetermined distance from the core metal 11. In other words, the first electrode 31 disposed on the insulator 21 is disposed in a state spaced a predetermined distance from the core metal 11. Moreover, the first electrode 31 and the foam 12 are disposed between the insulator 21 and the core metal 11.

[0062] The hooking portion 22 is a support piece capable of supporting the insulator 21 on the core metal 11. Specifically, the hooking portion 22 has a second recess 22a that hooks into a first recess 10a formed in the core metal 11. A part of the hooking portion 22 is inserted into the first recess 10a of the core metal 11, and an end of the first portion 11a of the core metal 11 is inserted into the second recess 22a, whereby the hooking portion 22 hooks into the first recess 10a formed in the core metal 11. In this way, the hooking portion 22 is connected to the core metal 11.

[0063] Here, the end portion of the first portion 11a of the core metal 11 refers to a tip portion of the first portion 11a which is located on the front side of the vehicle 3 in the cross section of the core metal 11.

[0064] Furthermore, the hooking portion 22 has a curved portion 22b in which the corners of the contour of the hooking portion 22 are rounded. Specifically, the hooking portion 22 has a corner with a predetermined radius R so that the corners formed in the hooking portion 22 are rounded. The curved portion 22b may be formed in the entire portion where the hooking portion 22 contacts the foam 12. This allows the foam 12 to flow when filling the hooking portion 22, so that the periphery of the hooking portion 22 is reliably filled with the foam 12.

[0065] Furthermore, the hooking portion 22 is integrally formed with the insulator 21 and cannot be separated from the insulator 21 without being destroyed. The hooking portion 22 may be a separate body that can be separated from the insulator 21 without being destroyed. In this case, for example, the hooking portion 22 may be connected to the insulator 21 by connecting a recess formed in the hooking portion 22 to a protrusion formed in the insulator 21. The hooking portion 22 may also be connected to the insulator 21 by an adhesive, a connecting member, or the like.

[0066] Moreover, a plurality of the hooking portions 22 are arranged on the core metal 11 and the insulator 21. For example, four or eight hooking portions 22 may be arranged on the core metal 11 and the insulator 21. The number of the hooking portions 22 shown in the present disclosure is merely an example, and is not limited to the number shown in the present disclosure. Moreover, a plurality of sets of one or more hooking portions 22 may be arranged on the rim 10 at approximately equal intervals.

[0067] The hook portion 22 is made of a resin material such as polycarbonate or polybutylene terephthalate.

[0068] The protrusion 23 is disposed at a position facing the curved portion 13 of the core metal 11. The protrusion 23 also protrudes from the insulator 21 toward the core metal 11. The tip of the protrusion 23 abuts against the core metal 11. In other words, the protrusion 23 is disposed between the insulator 21 and the core metal 11. Therefore, the protrusion 23 can maintain the position of the insulator 21 relative to the core metal 11 so that the insulator 21 and the first electrode 31 do not come into contact with the core metal 11.

[0069] Moreover, the protruding portion 23 has a curved portion 22b in which the corners of the contour of the protruding portion 23 are rounded. Specifically, in the protruding portion 23, a corner of a predetermined radius R is provided so that the corners formed in the protruding portion 23 are rounded. As a result, when the foam 12 is filled, the foam 12 flows, and the periphery of the protruding portion 23 is reliably filled with the foam 12.

[0070] Moreover, the protrusion 23 is formed integrally with the insulator 21 and cannot be separated from the insulator 21 without being destroyed. The protrusion 23 may be a separate body that can be separated from the insulator 21 without being destroyed. In this case, for example, the protrusion 23 may be connected to the insulator 21 by connecting a recess formed in the protrusion 23 to a protrusion formed in the insulator 21. The protrusion 23 may also be connected to the insulator 21 by an adhesive, a connecting member, or the like.

[0071] Moreover, a plurality of protrusions 23 are arranged on the core metal 11 and the insulator 21. For example, four or eight protrusions 23 may be arranged on the core metal 11 and the insulator 21. Note that the number of protrusions 23 shown in this disclosure is merely an example and is not limited to the number shown in this disclosure. Furthermore, the protrusions 23 may be arranged on the core metal 11 and the insulator 21 at approximately equal intervals.

[0072] Here, the relationship between the insulator 21, the engaging portion 22, and the protruding portion 23 will be described.

[0073] In this embodiment, the hook portion 22 is disposed at one end of the insulator 21 in a cross section of the insulator 21 cut along a plane perpendicular to the circumferential direction of the insulator 21 (hereinafter, sometimes referred to as a cross section of the insulator 21). The protrusion 23 is disposed at the other end of the insulator 21 in the cross section of the insulator 21. Therefore, when the cross section of the insulator 21 is viewed, one end of the insulator 21 is supported by the hook portion 22, and the other end of the insulator 21 is supported by the protrusion 23. As a result, the protrusion 23 and the hook portion 22 can maintain the position of the insulator 21 relative to the core metal 11 so that the insulator 21 and the first electrode 31 are spaced apart from the core metal 11.

[0074] The protruding portion 23 is made of a resin material such as polycarbonate or polybutylene terephthalate.

[0075] Here, the relationship between the core metal 11, the engaging portion 22, and the protruding portion 23 will be described.

[0076] In this embodiment, in a cross section of the rim 10 cut along a plane perpendicular to the circumferential direction of the rim 10 (hereinafter, sometimes referred to as a cross section of the rim 10), the protrusion 23 and the hook 22 sandwich the core metal 11, and the protrusion 23 and the hook 22 are arranged in positions facing each other via the core metal 11. Specifically, since a plurality of the protrusions 23 and the hook 22 are arranged on the insulator 21, the plurality of protrusions 23 and the plurality of hook 22 are arranged on the insulator 21 at substantially equal intervals so that the plurality of protrusions 23 and the plurality of hook 22 correspond one-to-one, one-to-many, or many-to-one. In other words, in the cross section of the rim 10, the protrusion 23 arranged on the other end of the insulator 21 and the hook 22 arranged on one end of the insulator 21 are arranged so as to sandwich the core metal 11. For this reason, the electrode structure 20 can be firmly attached to the core metal 11.

[0077] The first electrode 31 is made of a metal plating, a metal sheet, or a metal plate. When the first electrode 31 is a metal sheet or a metal plate, the metal sheet or the metal plate is attached to the first surface 21a of the insulator 21 by an adhesive or the like. The first electrode 31 is, for example, a metal containing copper, aluminum, or the like.

[0078] The first electrode 31 has a circular ring shape similar to that of the insulator 21. The first electrode 31 is disposed on a first surface 21a of the insulator 21, which is a surface facing the core metal 11 of the steering wheel 1. That is, the first electrode 31 is disposed along the inner peripheral surface of the insulator 21 facing the core metal 11 via the foam 12. The first electrode 31 is disposed apart from the core metal 11, and the foam 12 is filled between the first electrode 31 and the core metal 11. Therefore, the first electrode 31 is not electrically connected to the core metal 11.

[0079] Moreover, an AC voltage having the same phase as the AC voltage applied to the second electrode 32 is applied to the first electrode 31. The AC voltage applied to the first electrode 31 is an AC voltage applied from a power supply unit 41 by a control circuit 40 controlling the power supply unit 41, as shown in Fig. 4. Here, Fig. 4 is a block diagram showing a steering wheel 1 in the embodiment.

[0080] Here, the power supply unit 41 in FIG. 4 is controlled by the control circuit 40, and is therefore capable of applying an AC voltage to the first electrode 31 and the second electrode 32 via the harness.

[0081] 2 and 3, by applying an AC voltage of the same phase to the first electrode 31 and the second electrode 32, it is possible to cancel or reduce the capacitance between the first electrode 31 and the second electrode 32. Therefore, the control circuit 40 can detect a change in the capacitance generated between the second electrode 32 and the driver's hand.

[0082] The second electrode 32 is made of a metal plating, a metal sheet, or a metal plate. When the second electrode 32 is a metal sheet or a metal plate, the metal sheet or the metal plate is attached to the second surface 21b of the insulator 21 by an adhesive or the like. The second electrode 32 is, for example, a metal containing copper, aluminum, or the like.

[0083] The second electrode 32 has a circular ring shape similar to that of the insulator 21. The second electrode 32 is disposed on a second surface 21b, which is the surface opposite to the first surface 21a of the insulator 21. In other words, the second electrode 32 is disposed along the outer peripheral surface of the insulator 21 so as to sandwich the insulator 21 together with the first electrode 31.

[0084] An AC voltage is also applied to the second electrode 32. The AC voltage applied to the second electrode 32 is an AC voltage applied from the power supply unit 41 by the control circuit 40 controlling the power supply unit 41 in FIG. 4. Here, since the second electrode 32 is disposed on the outer peripheral surface of the insulator 21, when the part of the rim 10 where the second electrode 32 is disposed is gripped by the driver's hand, a capacitance is formed between the second electrode 32 and the hand. Therefore, the control circuit 40 can detect the grip of the rim 10 by the hand according to the change in the capacitance.

[0085] In addition, when the first electrode 31 and the second electrode 32 are viewed overlapping each other, the first electrode 31 covers the entire second electrode 32, and the surface area of ​​the first electrode 31 arranged on the first surface 21a is larger than the surface area of ​​the second electrode 32 arranged on the second surface 21b. Therefore, the first electrode 31 can shield the second electrode 32 and the core metal 11 so as to suppress changes in the capacitance between them.

[0086] In addition, the insulator 21, the first electrode 31, and the second electrode 32 are arranged in a range from at least the outer circumferential side of the rim 10 of the steering wheel 1 to the rear side of the vehicle 3 on a cross section of the steering wheel 1 cut by a plane perpendicular to the circumferential direction of the rim 10 of the steering wheel 1 (hereinafter sometimes referred to as the cross section of the steering wheel 1).

[0087] In this embodiment, the insulator 21, the first electrode 31, and the second electrode 32 are arranged over at least a quarter of the circumference along the circumferential direction of the cross section of the rim 10. In Fig. 2, the insulator 21, the first electrode 31, and the second electrode 32 are arranged over a range larger than the range A between two straight lines V1 and V2 indicated by the two-dot chain line. In this way, the insulator 21, the first electrode 31, and the second electrode 32 are arranged at locations that are likely to come into contact with the driver's hands when the driver grips the rim 10, and the electrode structure 20 can accurately detect the grip by the driver's hands.

[0088] [Foam 12] The foam 12 is a portion that is gripped by the driver's hands, and constitutes the outer shell of the rim 10 of the steering wheel 1. The foam 12 is made of a resin material, such as a urethane resin, such as polyurethane, that covers the electrode structure 20. The foam 12 embeds the insulator 21, the engaging portion 22, the protruding portion 23, the first electrode 31, the second electrode 32, and the core metal 11. In other words, the insulator 21, the engaging portion 22, the protruding portion 23, the first electrode 31, the second electrode 32, and the core metal 11 are covered by the foam 12 so as not to be exposed from the foam 12.

[0089] <Method of manufacturing the steering wheel 1> FIG. 5 is a flowchart showing a method for manufacturing the steering wheel 1 according to the embodiment.

[0090] 5, a core bar 11 and an electrode structure 20 are prepared. The electrode structure 20 is assembled by engaging the second recess 22a of the engagement portion 22 in the electrode structure 20 with the first recess 10a in the core bar 11 (S11: assembly step). This provides an assembled structure in which the electrode structure 20 is assembled to the core bar 11, with the engagement portion 22 of the electrode structure 20 engaged with the core bar 11.

[0091] Next, the assembled structure is fixed in the cavity of a mold, and the mold is clamped. Then, with the engaging portion 22 engaged with the core metal 11, the electrode structure 20 is covered with the foam 12. That is, the injection molding resin is poured into the cavity in the mold from a gate formed in the mold (S12: injection process). The injection molding resin is a resin material such as a urethane resin such as polyurethane.

[0092] This allows the foam 12 to cover the electrode structure 20 with the engaging portion 22 engaged with the core metal 11. In this manner, the steering wheel 1 can be obtained.

[0093] <Action and effect> The effects of the electrode structure 20, the steering wheel 1, and the method for manufacturing the steering wheel 1 in this embodiment will be described.

[0094] As described above, the electrode structure 20 of the present embodiment is an electrode structure 20 arranged on a steering wheel 1 provided on a vehicle 3, and includes an insulator 21, a first electrode 31 arranged on a first surface 21a of the insulator 21 which is the surface facing the core metal 11 of the steering wheel 1, a second electrode 32 arranged on a second surface 21b which is the surface opposite to the first surface 21a of the insulator 21, a protrusion 23 protruding from the insulator 21 toward the core metal 11, and a hooking portion 22 that hooks onto the core metal 11.

[0095] According to this, the electrode structure 20 can be attached to the core metal 11 in advance. This allows the electrode structure 20 to be disposed inside the steering wheel 1 when the steering wheel 1 is formed. Therefore, there is no need to form the steering wheel and then cut the steering wheel to dispose the first and second electrodes, as in the conventional method. Therefore, in this embodiment, it is difficult for the appearance of the steering wheel 1 to deteriorate and the number of steps required for manufacturing the steering wheel 1 to increase.

[0096] Therefore, the electrode structure 20 can prevent the manufacturing costs of the steering wheel 1 from increasing while ensuring the appearance of the steering wheel 1.

[0097] In particular, in this electrode structure 20, the postures of the first electrode 31 and the insulator 21 relative to the core metal 11 can be secured by the protruding portion 23 protruding from the insulator 21 toward the core metal 11 and the engaging portion 22 engaging with the core metal 11. Therefore, the protruding portion 23 and the engaging portion 22 can prevent the first electrode 31 and the core metal 11 from being electrically connected to each other. As a result, when the electrode structure 20 is used to detect gripping of the steering wheel 1, it can accurately detect that the driver's hands are gripping the steering wheel 1.

[0098] In addition, since the protrusion 23 and the engagement portion 22 can secure the posture of the first electrode 31 and the insulator 21 relative to the core metal 11, the electrode structure 20 can be reliably incorporated into the steering wheel 1 when the steering wheel 1 is molded from resin.

[0099] Furthermore, the protrusion 23 can maintain the distance between the core metal 11 and the first electrode 31, and the engaging portion 22 can engage the insulator 21 with the core metal 11, thereby fixing the insulator 21 to the core metal 11. This makes it possible to prevent the insulator 21 from shifting in position with respect to the core metal 11 or from rotating in the circumferential direction of the steering wheel 1 due to pressure applied during resin molding of the steering wheel 1.

[0100] Moreover, the electrode structure 20 of the present embodiment is an electrode structure 20 arranged on a steering wheel 1 provided on a vehicle 3, and includes an insulator 21 made of hard plastic, a first electrode 31 arranged on a first surface 21a of the insulator 21 which is the surface facing the core metal 11 of the steering wheel 1, and a second electrode 32 arranged on a second surface 21b which is the surface opposite to the first surface 21a of the insulator 21.

[0101] In this electrode structure 20 as well, since the insulator 21 on which the first electrode 31 and the second electrode 32 are arranged is made of hard plastic, for example, the electrode structure 20 can be attached to the core metal 11 in advance while ensuring the posture of the first electrode 31 and the insulator 21 relative to the core metal 11. This provides the same effects as those described above.

[0102] Moreover, the steering wheel 1 of this embodiment includes an electrode structure 20, a core metal 11, and a foam body 12 that covers the electrode structure 20.

[0103] This steering wheel 1 also provides the same effects as those described above.

[0104] In addition, in the manufacturing method of steering wheel 1 of the present embodiment, engaging portion 22 of electrode structure 20 is engaged with core metal 11. Then, in a state in which engaging portion 22 is engaged with core metal 11, electrode structure 20 is covered with foam 12.

[0105] This manufacturing method for steering wheel 1 also provides the same effects as those described above.

[0106] In the electrode structure 20 of this embodiment, the engaging portion 22 has a second recess 22a that engages with the first recess 10a formed in the core metal 11.

[0107] According to this, the first recess 10a and the second recess 22a engage with each other, so that the engaging portion 22 can fix the insulator 21 to the core metal 11. Therefore, it is possible to further prevent the insulator 21 from being misaligned with respect to the core metal 11 or from being rotated in the circumferential direction of the steering wheel 1 due to the pressure applied during resin molding of the steering wheel 1.

[0108] Furthermore, in the electrode structure 20 of this embodiment, in a cross section of the steering wheel 1 cut along a plane perpendicular to the circumferential direction of the steering wheel 1, the protrusion 23 and the hooking portion 22 sandwich the core wire 11, and the protrusion 23 and the hooking portion 22 are positioned opposite each other.

[0109] This allows the hook portion 22 to support the insulator 21 at a location corresponding to the position where the protrusion 23 supports the insulator 21. Therefore, the protrusion 23 and the hook portion 22 can be arranged in a state where the first electrode 31 and the insulator 21 are spaced apart from the core metal 11 so that the first electrode 31 does not come into contact with the core metal 11.

[0110] Furthermore, when forming the steering wheel 1, a space can be secured between the first electrode 31 and the insulator 21 into which the foam 12 can be filled. Therefore, the foam 12 can be resin-molded between the first electrode 31 and the insulator 21.

[0111] Moreover, it is possible to further prevent the insulator 21 from being displaced relative to the core metal 11 or from being rotated in the circumferential direction of the steering wheel 1 due to pressure applied during resin molding of the steering wheel 1.

[0112] In the electrode structure 20 of the present embodiment, the core metal 11 has a curved portion 13 in a cross section obtained when the steering wheel 1 is cut along a plane perpendicular to the circumferential direction of the steering wheel 1. The protruding portion 23 is disposed at a position opposite to the curved portion 13.

[0113] According to this, even if the core metal 11 has a curved portion 13, the protrusion 23 can be positioned to space the first electrode 31 and the insulator 21 away from the curved portion 13 so that the first electrode 31 does not come into contact with the core metal 11.

[0114] In the electrode structure 20 of the present embodiment, the protrusion 23 and the hook 22 are formed integrally with the insulator 21 .

[0115] This makes it possible to suppress an increase in the number of steps, such as bonding the protruding portion 23 and the engaging portion 22 to the insulator 21.

[0116] In addition, in the electrode structure 20 of this embodiment, the insulator 21, the first electrode 31, and the second electrode 32 are arranged at least in the range from the outer periphery of the steering wheel 1 to the rear side of the vehicle 3 in the cross section of the steering wheel 1 cut by a plane perpendicular to the circumferential direction of the steering wheel 1.

[0117] According to this, when the driver's hands grip the steering wheel 1, the electrode structure 20 can be disposed at a position where the driver's hands are likely to come into contact with the surface of the steering wheel 1. Therefore, gripping by the driver's hands can be reliably detected.

[0118] In addition, since it is not necessary to arrange the electrode structure 20 over the entire steering wheel 1, an increase in the material cost of the electrode structure 20 can be suppressed.

[0119] In the electrode structure 20 of the present embodiment, the protruding portion 23 and the engaging portion 22 have curved surface portions 22b in which the corners of the contours of the protruding portion 23 and the engaging portion 22 are rounded.

[0120] According to this, in manufacturing the steering wheel 1, for example, when the foam 12 is filled so as to cover the core metal 11, the insulator 21, the first electrode 31, and the second electrode 32, the foam 12 can be made to flow. Therefore, the foam 12 can be reliably filled around the protrusion 23 and the engagement portion 22.

[0121] In the electrode structure 20 of the present embodiment, the insulator 21 is made of a resin material. The first electrode 31 is made of a metal plating, a metal sheet, or a metal plate. The second electrode 32 is made of a metal plating, a metal sheet, or a metal plate.

[0122] This allows the insulator 21 to be formed using a resin material in accordance with the shape and size of the core metal 11. Also, since the first electrode 31 and the second electrode 32 can be arranged in the insulator 21, a member in which the insulator 21, the first electrode 31 and the second electrode 32 are integrated can be easily assembled to the core metal 11. Furthermore, if a certain level of strength is ensured in the insulator 21, the insulator 21 allows the first electrode 31 to be arranged in a state in which the first electrode 31 is separated from the core metal 11.

[0123] In the electrode structure 20 of the present embodiment, an AC voltage having the same phase as the AC voltage applied to the second electrode 32 is applied to the first electrode 31 .

[0124] This can cancel or reduce the capacitance between the first electrode 31 and the second electrode 32. Therefore, by using the control circuit 40 that detects the grip of the steering wheel 1 by the driver's hand, the control circuit 40 can accurately detect the change in capacitance between the second electrode 32 and the driver's hand that occurs when the driver's hand grips the steering wheel 1.

[0125] In the electrode structure 20 of the present embodiment, the metal core 11 is annular. The insulator 21 is shaped to be disposed along the surface of the metal core 11 on the outer circumferential side.

[0126] This allows the insulator 21 to be arranged in accordance with the outer shape of the core metal 11. This allows the electrode structure 20 to have increased versatility.

[0127] In the electrode structure 20 of the present embodiment, the first electrode 31 is made of a metal plating, a metal sheet, or a metal plate, and the second electrode 32 is made of a metal plating, a metal sheet, or a metal plate.

[0128] According to this, the first electrode 31 and the second electrode 32 can be arranged on the insulator 21, and therefore a member in which the insulator 21, the first electrode 31, and the second electrode 32 are integrated can be easily assembled to the core metal 11. Furthermore, if a certain level of strength is ensured for the insulator 21, the insulator 21 can arrange the first electrode 31 in a state in which the first electrode 31 is spaced apart from the core metal 11.

[0129] (First Modification of the Embodiment) The electrode structure 20 and steering wheel 1 of this modified example differ from the electrode structure and steering wheel of the embodiment in that the engaging portion 122a engages with the core metal 11. The electrode structure 20 and steering wheel 1 of this modified example have the same configurations and functions as those of the electrode structure and steering wheel of the embodiment, and the detailed description of the configurations and functions will be omitted by using the same reference numerals.

[0130] FIG. 6 is a cross-sectional view showing a steering wheel 1 in a first modified example of the embodiment.

[0131] 6, the hooking portion 122a of this modification is disposed across the first portion 11a and the second portion 11b of the core metal 11, and thereby hooks onto the core metal 11. That is, the second recess 22a of the hooking portion 122a hooks onto the core metal 11 so as to sandwich the core metal 11 from the first portion 11a to the second portion 11b of the core metal 11. This allows the hooking portion 122a and the core metal 11 to be more firmly connected. This makes it possible to prevent the insulator 21 from being displaced relative to the core metal 11 or from being rotated in the circumferential direction of the steering wheel 1 due to pressure applied during resin molding of the steering wheel 1.

[0132] (Modification 2 of the embodiment) The electrode structure 20 and steering wheel 1 of this modified example differ from the electrode structure and steering wheel of the embodiment in that the engaging portion 122b engages with the second portion 11b of the core metal 11. The electrode structure 20 and steering wheel 1 of this modified example have the same configurations and functions as those of the electrode structure and steering wheel of the embodiment, and the same reference numerals are used for the configurations and functions, and detailed descriptions of the configurations and functions will be omitted.

[0133] FIG. 7 is a cross-sectional view showing a steering wheel 1 according to a second modification of the embodiment.

[0134] As shown in FIG. 7, the hooking portion 122b of this modification is hooked to the second portion 11b of the core metal 11. Specifically, the hooking portion 122b extends from the insulator 21 to the second portion 11b of the core metal 11. The first portion 11a of the core metal 11 is in contact with the hooking portion 122b. The second recess 22a of the hooking portion 122b is hooked to the second portion 11b of the core metal 11. This allows the hooking portion 122b to be connected to the second portion 11b in a state in which the hooking portion 122b is in contact with the first portion 11a of the core metal 11, so that the hooking portion 122b and the core metal 11 can be more firmly connected to each other. This makes it possible to prevent the insulator 21 from being displaced relative to the core metal 11 or from being rotated in the circumferential direction of the steering wheel 1 due to the pressure applied during resin molding of the steering wheel 1.

[0135] (Third Modification of the Embodiment) The electrode structure 20 and steering wheel 1 of this modified example differ from the electrode structure and steering wheel of the embodiment in that the engaging portion 122c engages with the first portion 11a and the second portion 11b of the core metal 11. The electrode structure 20 and steering wheel 1 of this modified example have the same configurations and functions as the electrode structure and steering wheel of the embodiment, and the detailed description of the configurations and functions will be omitted by using the same reference numerals.

[0136] FIG. 8 is a cross-sectional view showing a steering wheel 1 in a third modified example of the embodiment.

[0137] As shown in FIG. 8, the hooking portion 122c of this modification is hooked to the first portion 11a and the second portion 11b of the core metal 11. Specifically, the hooking portion 122c extends from the insulator 21 to the second portion 11b of the core metal 11 via the first portion 11a. The hooking portion 122c is formed with two second recesses 22a. One of the two second recesses 22a is hooked to the first portion 11a of the core metal 11, and the other of the two second recesses 22a is hooked to the second portion 11b of the core metal 11. As a result, one of the second recesses 22a is connected to the first portion 11a of the core metal 11, and the other second recess 22a is connected to the second portion 11b of the core metal 11, so that the hooking portion 122c and the core metal 11 can be more firmly connected to each other. Therefore, it is possible to prevent the insulator 21 from being displaced relative to the core metal 11 or from being rotated in the circumferential direction of the steering wheel 1 due to pressure applied during resin molding of the steering wheel 1.

[0138] (Fourth Modification of the Embodiment) The electrode structure 20 and steering wheel 1a of this modification differ from the electrode structure and steering wheel of the embodiment in that an insulator separate from the insulator 21 is provided. The configurations and functions of the electrode structure 20 and steering wheel 1a of this modification are the same as those of the electrode structure and steering wheel of the embodiment, and the same reference numerals are used to denote the same configurations and functions, and detailed descriptions of the configurations and functions will be omitted. In this modification, the insulator 21 is called the first insulator 21, and the insulator separate from the insulator 21 is called the second insulator 29.

[0139] FIG. 9 is a cross-sectional view showing a steering wheel 1a in a fourth modified example of the embodiment.

[0140] In this modification, as shown in Fig. 9, a second insulator 29 is disposed between the core metal 11 and the first electrode 31. Specifically, the second insulator 29 has an annular shape and is disposed between the core metal 11 and the first electrode 31 along the outer peripheral surface of the core metal 11. That is, the second insulator 29 is sandwiched between the core metal 11 and the first electrode 31. This allows the second insulator 29 to fill the gap between the core metal 11 and the first electrode 31 so that the foam 12 does not enter between the second insulator 29 and the core metal 11 and between the second insulator 29 and the first electrode 31.

[0141] Moreover, the second insulator 29 may be included in a component of the electrode structure 20, or may be included in a component of the steering wheel 1a.

[0142] The second insulator 29 is made of a resin material such as a hard plastic, for example, polycarbonate or polybutylene terephthalate.

[0143] This allows the posture of the first insulator 21 relative to the core 11 to be maintained so that the first electrode 31 and the core 11 do not come into contact with each other, thereby more reliably securing the distance between the first electrode 31 and the core 11.

[0144] (Other variations) The electrode structure, steering wheel, and steering wheel manufacturing method according to the present disclosure have been described above based on the above-mentioned embodiments, but the present disclosure is not limited to these embodiments. As long as the modifications do not deviate from the spirit of the present disclosure, modifications that a person skilled in the art may make to the embodiments may also be included in the scope of the present disclosure.

[0145] For example, in the electrode structure, steering wheel, and steering wheel manufacturing method according to the above embodiment, the protrusion and the engagement portion may not be arranged at a position facing each other in the cross section of the steering wheel. Specifically, when a plurality of protrusions and engagement portions are arranged on the insulator, the plurality of protrusions and the plurality of engagement portions may be arranged on the insulator so that the plurality of protrusions and the plurality of engagement portions do not correspond to each other. That is, only one of the protrusion arranged on the other end of the insulator and the engagement portion arranged on one end of the insulator may be arranged on the cross section of the rim. For example, the four engagement portions and the six protrusions may not be arranged at a position facing each other in the cross section of the steering wheel when the protrusion and the engagement portion are molded from the resin. In this case, it is possible to suppress the fluidity of the injection molding resin from being hindered when the foam is molded from the resin.

[0146] In the electrode structure, the steering wheel, and the method for manufacturing the steering wheel according to the above-described embodiments, the steering wheel may further include a control circuit.

[0147] In addition, the present disclosure also includes forms obtained by applying various modifications to the above-described embodiments that a person skilled in the art may conceive, and forms realized by arbitrarily combining the components and functions of each embodiment within the scope that does not deviate from the spirit of the present disclosure. [Industrial Applicability]

[0148] The electrode structure, steering wheel, and steering wheel manufacturing method of the present disclosure are applicable to, for example, vehicle steering wheels. [Explanation of symbols]

[0149] 1, 1a Steering wheel 3. Vehicle 10a First recess 11 Core wire 12 Foam 13 Curved section 20 Electrode structure 21 Insulator (first insulator) 21a 1st page 21b 2nd side 22, 122a, 122b, 122c interlocking part 22a Second recess 22b Curved part 23 Protrusion 31 1st electrode 32 2nd electrode

Claims

1. An electrode structure to be disposed on a steering wheel of a vehicle, An insulator; a first electrode disposed on a first surface of the insulator, the first surface being a surface facing a core metal of the steering wheel; a second electrode disposed on a second surface of the insulator opposite to the first surface; a protruding portion protruding from the insulator toward the core metal; and a hook portion that hooks onto the core metal. Electrode structure.

2. The engaging portion has a second recess that engages with a first recess formed in the core metal. The electrode structure of claim 1 .

3. In a cross section of the steering wheel taken along a plane perpendicular to a circumferential direction of the steering wheel, the protruding portion and the engaging portion sandwich the core metal, and the protruding portion and the engaging portion are disposed in opposing positions. The electrode structure according to claim 1 or 2.

4. the core metal has a curved portion that is curved in a cross section when the steering wheel is cut along a plane perpendicular to a circumferential direction of the steering wheel, The protruding portion is disposed at a position opposite to the curved portion. The electrode structure according to claim 1 or 2.

5. The protrusion and the engagement portion are integrally formed with the insulator. The electrode structure according to any one of claims 1 to 4.

6. the insulator, the first electrode, and the second electrode are disposed in a range from at least an outer circumferential side of the steering wheel to a rear side of the vehicle in a cross section of the steering wheel taken along a plane perpendicular to a circumferential direction of the steering wheel; The electrode structure according to any one of claims 1 to 5.

7. The protrusion and the engagement portion have curved surface portions in which corners of the contours of the protrusion and the engagement portion are rounded. The electrode structure according to any one of claims 1 to 6.

8. The insulator is made of a resin material, The first electrode is formed of a metal plating, a metal sheet, or a metal plate; The second electrode is composed of a metal plating, a metal sheet, or a metal plate. The electrode structure according to any one of claims 1 to 7.

9. An AC voltage having the same phase as an AC voltage applied to the second electrode is applied to the first electrode. The electrode structure according to any one of claims 1 to 8.

10. An electrode structure according to any one of claims 1 to 9; The core metal, A foam covering the electrode structure. Steering wheel.

11. The electrode structure according to any one of claims 1 to 9 is provided with an engagement portion which is engaged with the core metal, the electrode structure is covered with a foam in a state where the engaging portion is engaged with the core metal; A method for manufacturing a steering wheel.

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