Steering wheel and method for manufacturing the same

Abstract

In a steering wheel (10), a sensor member (22) includes a mounting part (31) that is formed of an insulating material and is configured to be mounted on the outer surface of a core material (21), and a sensor body (32) that is joined to the outer surface of the mounting part (31). The mounting part (31) includes an opening (P2) in a part of a second direction (Dir2) that is the circumferential direction along outer peripheral lines (21a, 21b, 21c) of the core material (21) in a cross section (SE), and a pair of end parts (41c) for forming the opening (P2), and has the shape of an inner peripheral line (41b) corresponding to a part of the shapes of the outer peripheral lines (21a, 21b, 21c) of the core material (21). An outer layer member (23) includes an outer layer protrusion (52) that protrudes inward, and the outer layer protrusion (52) is present in a gap between the pair of end parts (41c) of the mounting part (31) and is in contact with the core material (21).

Description

Steering wheel and manufacturing method thereof

[0001] The present disclosure relates to steering wheels and methods of manufacturing the same.

[0002] Patent Document 1 discloses a steering wheel including a core member having a cross-sectional shape such as a U-shape, an electrode structure disposed along a portion of the outer peripheral surface of the core member for detecting capacitance, and a foam covering the core member and the electrode structure. The electrode structure has a protrusion that abuts against the outer peripheral surface of the core member so that the electrode portion does not contact the core member, and a recess into which the U-shaped end of the core member is inserted. A method for manufacturing a steering wheel includes fixing an assembly structure in which the electrode structure is fixed to the core member in a cavity of a mold, and molding the foam member by injection molding.

[0003] Patent Document 2 discloses a steering wheel including a core material having a cross-sectional shape such as a U-shape, a resin inner layer material covering the outer surface of the core material, an electrostatic sheet covering the outer surface of the resin inner layer material, and a resin outer layer material covering the outer surface of the electrostatic sheet. The resin inner layer material is formed by injection molding and integrated with the core material. The electrostatic sheet is pre-formed into a C-shape corresponding to the curved outer surface of the core material. After the C-shaped electrostatic sheet is placed on the outside of the resin inner layer material, the electrostatic sheet is heated to bond the electrostatic sheet to the outer surface of the resin inner layer material. The resin outer layer material is formed by injection molding and bonded to the outer surface of the electrostatic sheet.

[0004] JP 2023-32819 A JP 2019-117182 A

[0005] The center line of the core material of a steering wheel is curved, making it difficult to mount a sensor on the outer periphery of the core material. While technologies such as those described in Patent Documents 1 and 2 have improved mountability, there is still room for improvement.

[0006] To improve the fit to the core material, it is possible to form the sensor part from a material that is easily deformed and to fit the sensor part to the core material while deforming it. However, from the viewpoint of the detection performance of the sensor part, it is better to avoid excessive deformation of the sensor part when fitting it.

[0007] The present disclosure has been made in consideration of this background, and aims to provide a steering wheel and a manufacturing method thereof that can improve the attachability of the sensor portion while suppressing excessive deformation of the sensor portion when attached.

[0008] One aspect of the present disclosure relates to a steering wheel comprising: a core material extending in a first direction, which is a direction along a predetermined curve; a sensor member attached to an outer surface of the core material; and an outer layer member covering the outer surface of the sensor member, wherein the sensor member comprises: an attachment portion formed of an insulating material and configured to be attached to the outer surface of the core material; and a sensor main body joined to the outer surface of the attachment portion, wherein the attachment portion has an opening in a part of a second direction, which is a circumferential direction along the outer periphery of the core material, in a cross section perpendicular to a center line of the core material extending in the first direction, and has a pair of ends for forming the opening, and has an inner periphery shape corresponding to a part of the outer periphery shape of the core material, wherein the outer layer member has an outer layer protrusion protruding inward, and the outer layer protrusion is located in a gap between the pair of ends of the attachment portion and in contact with the core material.

[0009] Another aspect of the present disclosure is a method for manufacturing the steering wheel, comprising the steps of: attaching the sensor member to the core material; and placing the unit in which the sensor member is attached to the core material in a mold, molding the outer layer member by injection molding, and integrating the core material, the sensor member, and the outer layer member.

[0010] According to one aspect of the present disclosure, a sensor member constituting a steering wheel is attached to an outer surface of a core material that extends in a first direction along a predetermined curve. Because the core material is formed in a shape that extends in the first direction along a curve, it is not easy to attach the sensor member to the outer surface of the core material.

[0011] However, the sensor member includes an attachment portion in addition to the sensor main body. The attachment portion is configured to be attached to the outer surface of the core material. This attachment portion is configured to have an opening in a cross section perpendicular to the center line extending in the first direction, in a part of the second direction, which is the circumferential direction along the outer periphery of the core material. In other words, the attachment portion has a pair of ends for forming the opening. Therefore, since the attachment portion has an opening in the cross section, it is easy to attach the attachment portion to the core material.

[0012] Furthermore, the mounting portion has an inner peripheral line shape in the cross section that corresponds to a part of the outer peripheral line shape of the core material. Therefore, when the mounting portion is attached to the core material, the mounting portion can be positioned at a desired position relative to the core material. As described above, the mounting portion can be easily attached to the core material and can be positioned at a stable position relative to the core material. In this way, the mounting portion is configured to improve the attachability to the core material.

[0013] The sensor body that constitutes the sensor member is bonded to the outer surface of the attachment part. Therefore, the sensor body itself does not need to improve the attachability to the core material. Therefore, the sensor member including the attachment part and the sensor body can be attached to the core material with good attachability.

[0014] Furthermore, since the sensor body is bonded to the outer surface of the attachment part, excessive deformation of the sensor body constituting the sensor member can be suppressed when the sensor member is attached to the core material, which can improve the detection performance of the sensor body.

[0015] The steering wheel further includes an outer layer member covering the outer surface of the sensor member. The outer layer member has outer layer protrusions that protrude inward. The outer layer protrusions are located in the gap between the pair of ends of the mounting portion and are arranged to contact the core member. Therefore, the outer layer protrusions can restrict rotation of the outer layer member relative to the core member and the sensor body. In other words, the outer layer protrusions function to maintain the position of the outer layer member relative to the core member and the sensor body.

[0016] According to another aspect of the present disclosure, a unit in which the sensor member is attached to a core member is placed in a mold, and the outer layer member is molded by injection molding. In this way, the core member, the sensor member, and the outer layer member are integrated, and the outer layer member can be formed into the above-described shape. Therefore, a steering wheel having the above-described functions can be easily manufactured.

[0017] As described above, it is possible to provide a steering wheel and a manufacturing method thereof that can improve the attachability of the sensor portion while preventing the sensor portion from being excessively deformed when attached.

[0018] FIG. 1 is a front view of a steering wheel according to a first embodiment. FIG. 2 is an enlarged perspective cross-sectional view of portion A in FIG. 1. FIG. 3 is a perspective cross-sectional view showing a portion of a core material constituting the steering wheel shown in FIG. 2. FIG. 4 is a perspective cross-sectional view showing a portion of a sensor member constituting the steering wheel shown in FIG. 2. FIG. 5 is a perspective cross-sectional view showing a portion of a sensor main body constituting the sensor member shown in FIG. 4. FIG. 6 is a perspective cross-sectional view showing a portion of an outer layer member constituting the steering wheel shown in FIG. 2. FIG. 7 is an enlarged view of portion B in FIG. 2. FIG. 8 is a flowchart showing a method for manufacturing a steering wheel. FIG. 9 is a flowchart showing a method for manufacturing a steering wheel according to a second embodiment. FIG. 10 is a partially enlarged perspective cross-sectional view of a steering wheel according to a third embodiment. FIG. 11 is a partially enlarged perspective cross-sectional view of a steering wheel according to a fourth embodiment. FIG. 12 is a partially enlarged perspective cross-sectional view including a sensor member constituting a steering wheel according to a fifth embodiment. FIG. 13 is an enlarged view of portion B in FIG. 2 according to a sixth embodiment. FIG. 14 is a front view of a steering wheel according to a seventh embodiment.

[0019] (Embodiment 1) 1. Overall Configuration of Steering Wheel 10 The overall configuration of the steering wheel 10 will be described with reference to Fig. 1. As shown in Fig. 1, the steering wheel 10 includes a core portion 11, a grip portion 12, and a plurality of spoke portions 13 (three in this embodiment) that connect the core portion 11 and the grip portion 12.

[0020] The grip portion 12 is formed, for example, in a circular ring shape. However, the grip portion 12 can be formed in any shape, such as a polygonal ring shape or a shape separated into left and right sides. The center line L1 of the grip portion 12 is configured to extend in a first direction Dir1, which is a direction along a predetermined curve. This means that the center line L1 of the grip portion 12 is not a single straight line, and includes cases where it is formed only by a curve, where it is formed by a curve and a straight line, and where it is formed by multiple straight lines in different directions.

[0021] When the grip portion 12 has a circular ring shape, the first direction Dir1 is a direction along the circle with the same curvature. When the grip portion 12 has a polygonal ring shape, the first direction Dir1 is a direction along the polygon. When the grip portion 12 has a shape separated into left and right, the first direction Dir1 is a direction along the shape corresponding to each of the left and right grip portions 12.

[0022] 2 to 6, the structure of the grip portion 12 will be described. As described above, the grip portion 12 extends in a first direction Dir1 (shown in FIG. 1), which is a direction along a predetermined curve. The grip portion 12 includes a core material 21, a sensor member 22 disposed on the outer surface of the core material 21, and an outer layer member 23 disposed on the outer surface of the sensor member 22.

[0023] 2, the core material 21 constitutes the center of the grip portion 12 and is formed in a shape corresponding to the shape of the grip portion 12. In other words, the core material 21 extends in a first direction Dir1, which is a direction along a predetermined curve. In this embodiment, the core material 21 is formed in a circular ring shape.

[0024] As shown in FIGS. 2 and 3 , in a cross section SE perpendicular to a center line L1 (shown in FIG. 1 ) of the core material 21 extending in the first direction Dir1, the core material 21 is formed in a U-shape or a C-shape. The U-shaped or C-shaped opening P1 of the core material 21 is located at the bottom of FIG. 2 , i.e., toward the back of FIG. 1 . Therefore, as shown in FIGS. 2 and 3 , the outer surface of the core material 21 has an upper outer periphery 21a, a left outer periphery 21b, and a right outer periphery 21c in the cross section SE. The outer peripheries 21a, 21b, and 21c of the core material 21 are formed as convex or linear lines extending outward. However, the outer peripheries 21a, 21b, and 21c of the core material 21 may also be formed as slightly concave lines. The core material 21 also has a recess 21d that opens downward in FIGS. 2 and 3 . The recess 21d of the core material 21 is formed over the entire length in the first direction Dir1. The recess 21d of the core material 21 may be open in a direction other than the downward direction in FIG.

[0025] The core material 21 is made of any metal such as steel, aluminum, or magnesium. In this embodiment, the core material 21 is electrically conductive. However, the core material 21 may be made of any material other than metal as long as it has a predetermined rigidity. The core material 21 may also be made of a material that is not electrically conductive. The core material 21 is firmly connected to the spoke portion 13.

[0026] As shown in Fig. 2, the sensor member 22 is attached to the outer surface of the core material 21. In this embodiment, the sensor member 22 is attached to a part of the outer surface of the core material 21. "Attached" means that the target member is attached to the mating member. In other words, the sensor member 22 is formed separately from the core material 21, and by attaching the sensor member 22 to the core material 21, the two are integrated.

[0027] Here, by attaching the sensor member 22, the core material 21 and the sensor member 22 may be joined, or the core material 21 and the sensor member 22 may be in contact without being joined. However, regardless of whether the sensor member 22 is joined or not, when the sensor member 22 is attached to the core material 21, the sensor member 22 needs to be held in position relative to the core material 21 to a certain extent. In this embodiment, the sensor member 22 is held in position by being fitted into the core material 21 and mechanically engaging with the core material 21. Therefore, even if the core material 21 and the sensor member 22 are not joined, the sensor member 22 is held in position relative to the core material 21.

[0028] 4, the sensor member 22 includes a mounting portion 31 and a sensor main body 32. The mounting portion 31 is located inside the sensor member 22, and the sensor main body 32 is located outside the sensor member 22.

[0029] The mounting portion 31 is formed from an insulating material. For example, the mounting portion 31 is formed from at least one of a resin, an elastomer, and a foam. An example of a resin is polyolefin (ethylene octene). Examples of an elastomer are SEBS (a block copolymer of styrene, ethylene, butadiene, and styrene) and EPDM (ethylene propylene diene rubber). Examples of a foam are polyurethane foam, polyethylene foam, and EPDM (ethylene propylene diene rubber). The melting point of the mounting portion 31 is lower than the lowest melting point of the materials constituting the sensor body 32.

[0030] The mounting portion 31 is attached to the outer surface of the core material 21. As shown in FIG. 4, the mounting portion 31 includes a mounting portion main body 41 and a mounting portion protrusion 42.

[0031] The mounting portion body 41 is formed to extend along the center line L1 (shown in FIG. 1) of the core material 21. Furthermore, in a cross section SE perpendicular to the center line L1, the mounting portion body 41 has a shape extending in a second direction Dir2, which is the circumferential direction along the outer circumferential lines 21a, 21b, and 21c of the core material 21. The mounting portion body 41 is formed, for example, in a C-shape or U-shape in the cross section SE. Therefore, the mounting portion body 41 has an outer circumferential line 41a and an inner circumferential line 41b in the C-shape or U-shape in the cross section SE.

[0032] The shape of the outer peripheral line 41a of the mounting portion main body 41 is arc-shaped. However, the shape of the outer peripheral line 41a is not limited to an arc-shaped shape. Furthermore, the shape of the inner peripheral line 41b of the mounting portion main body 41 corresponds to the shapes of parts of the outer peripheral lines 21a, 21b, and 21c of the core material 21. In this embodiment, the shape of the inner peripheral line 41b of the mounting portion main body 41 corresponds to the entire upper outer peripheral line 21a of the core material 21, the entire left outer peripheral line 21b, and only part of the right outer peripheral line 21c. In other words, the shape of the inner peripheral line 41b of the mounting portion main body 41 does not have a part that corresponds to the part of the right outer peripheral line 21c.

[0033] Furthermore, the mounting body 41 has an opening P2 in a part of the second direction Dir2. In Fig. 4, the opening P2 is located on the right side. That is, the mounting body 41 has a pair of ends 41c for forming the opening P2.

[0034] The minimum width of the opening P2, i.e., the opening width of the pair of end portions 41c, is D1. In this embodiment, the distance between the pair of end portions 41c increases toward the inside.

[0035] The mounting portion protrusion 42 is formed to protrude inward. In the cross section SE, the mounting portion protrusion 42 protrudes inward from the inner circumferential line 41b of the mounting portion main body 41. In FIG. 4, the mounting portion protrusion 42 protrudes upward from a lower portion of the inner circumferential line 41b of the mounting portion main body 41. The mounting portion protrusion 42 is formed in a shape corresponding to the recess 21d of the core material 21. Therefore, as shown in FIG. 2, the mounting portion protrusion 42 is configured to fill the recess 21d of the core material 21. In other words, in the cross section SE, the shape of the mounting portion protrusion 42 corresponds to the shape of the recess 21d of the core material 21. Note that the mounting portion protrusion 42 fills the recess 21d of the core material 21 without any gaps. However, a small gap may be formed between the mounting portion protrusion 42 and the recess 21d of the core material 21.

[0036] 4 , in cross section SE, the opening width D1 of the pair of ends 41c of the mounting portion main body 41 is smaller than the maximum distance D2 between two points on the inner surface of the mounting portion 31. Therefore, when mounting the mounting portion 31 to the core material 21, it is necessary to widen the opening P2 of the mounting portion 31. Furthermore, when mounting the mounting portion 31 to the core material 21, it is also necessary to widen the opening P2 of the mounting portion 31 so that the mounting portion protrusions 42 can be inserted into the recesses 21d of the core material 21.

[0037] 2, in cross section SE, the inner circumferential line 41b of the mounting body 41 contacts the entire upper outer circumferential line 21a, the entire left outer circumferential line 21b, and only a portion of the right outer circumferential line 21c of the core material 21. Also, in cross section SE, the shape line of the mounting protrusion 42 contacts the shape line of the recess 21d of the core material 21. However, in cross section SE, due to the opening P2, the mounting body 41 does not have a portion corresponding to the remaining portion of the right outer circumferential line 21c of the core material 21.

[0038] Here, in the cross section SE, the inner peripheral line 41b of the mounting portion main body 41 and the geometric line of the mounting portion protrusion 42 may be joined to the outer peripheral lines 21a, 21b, 21c and the geometric line of the recess 21d of the core material 21, or they may be in contact without being joined. "Joining" refers to joining by adhesive, joining by the adhesive force of the materials themselves, etc.

[0039] 2, the mounting portion main body 41 covers most of the outer surface of the core material 21, and the mounting portion protrusions 42 are embedded in the recesses 21d of the core material 21, so that the mounting portion 31 can be held in position relative to the core material 21. In particular, when mounting the mounting portion 31 to the core material 21, the opening P2 of the mounting portion 31 is widened. The mounting portion 31 is configured to be fitted into the core material 21, so that it mechanically engages with the core material 21, thereby holding its position.

[0040] The sensor main body 32 constitutes, for example, an electrostatic sensor. Therefore, the sensor main body 32 includes electrodes. The sensor main body 32 detects when the driver's hand comes into contact with the grip portion 12. The sensor main body 32 may include a heater wire that functions as a heater in addition to the electrodes that function as an electrostatic sensor. The sensor main body 32 may also include a conductive layer that functions as both the electrodes that function as an electrostatic sensor and the heater wire that functions as a heater.

[0041] The sensor body 32 is made of a flexible material. As shown in FIG. 5 , the sensor body 32 is formed so as to extend along the center line L1 (shown in FIG. 1 ) of the core material 21. Furthermore, in a cross section SE perpendicular to the center line L1, the sensor body 32 has a shape that extends in a second direction Dir2, which is the circumferential direction along the outer circumferential line 41a of the mounting body 41. The sensor body 32 is formed, for example, in a C-shape or U-shape in the cross section SE. Therefore, the sensor body 32 has an opening P3 at a position corresponding to the opening P2 of the mounting body 41.

[0042] 4, the sensor body 32 is bonded to the outer surface of the mounting body 41. The term "bonding" here refers to bonding with an adhesive, bonding by the adhesive force of the material itself, and the like.

[0043] The thickness of the sensor body 32 is formed thinner than the maximum thickness of the mounting portion 31. Therefore, at the cross section SE, the bending rigidity of the mounting portion 31 is higher than the bending rigidity of the sensor body 32. The bending rigidity (EI) is expressed by "Young's modulus (E) x moment of inertia (I)". In other words, when comparing the bending rigidity of the sensor body 32 alone with the bending rigidity of the unit in which the mounting portion 31 and the sensor body 32 are joined, the bending rigidity of the latter unit is higher. Therefore, even if the position retention force of the sensor body 32 alone is low, by joining the sensor body 32 to the mounting portion 31, the position retention force of the unit as a whole is increased.

[0044] The sensor body 32 is formed in a sheet shape and has no notches on the outer periphery. Specifically, when the C-shape or U-shape of the sensor body 32 is unfolded and placed on a plane, the sensor body 32 has no notches on the outer periphery, for example, a rectangular shape. This simplifies the structure of the sensor body 32. The sensor body 32 may also have a notch on the outer periphery.

[0045] In order to mount the sensor main body 32 on the core material 21 whose center line L1 is a curve, a notch is usually provided on the outer periphery to prevent wrinkles from forming. However, in this embodiment, the sensor main body 32 does not have such a notch. The reason for this will be described later.

[0046] 2, the outer layer member 23 covers the outer surface of the sensor member 22. In this embodiment, the outer layer member 23 covers the entire outer surface of the sensor member 22 and also covers the portion of the core material 21 that is not covered by the sensor member 22.

[0047] The outer layer member 23 is formed of an insulating material. The outer layer member 23 is formed of, for example, at least one of a resin, an elastomer, and a foam. An example of a resin is polyolefin (ethylene octene). Examples of elastomers are SEBS (a block copolymer of styrene, ethylene, butadiene, and styrene) and EPDM (ethylene propylene diene rubber). Examples of foams are polyurethane foam, polyethylene foam, and EPDM (ethylene propylene diene rubber). The melting point of the outer layer member 23 is lower than the lowest melting point of the materials constituting the sensor body 32 and lower than the melting point of the mounting portion 31.

[0048] As shown in FIGS. 2 and 6 , the outer layer member 23 includes an outer layer main body 51 and outer layer projections 52 .

[0049] The outer layer body 51 is formed in an endless ring shape in the cross section SE. In this embodiment, the outer layer body 51 is formed in a circular ring shape in the cross section SE. The outer surface of the outer layer body 51 is the part that the driver's hand comes into contact with. In the cross section SE, the thickness of the outer layer body 51 is set to have cushioning properties to improve the driver's gripping feel, and to enable a sensor member to detect when the driver's hand comes into contact with the outer layer body 51.

[0050] The inner surface of the outer layer main body 51 contacts the entire outer surface of the sensor member 22 and contacts the portion of the outer surface of the mounting portion 31 where the sensor member 22 is not present. Therefore, the outer layer main body 51 completely covers the sensor member 22 and the mounting portion 31.

[0051] The outer layer protrusions 52 are formed to protrude inward. In cross section SE, the outer layer protrusions 52 protrude inward from the inner circumferential line of the outer layer main body 51. In FIG. 6, the outer layer protrusions 52 protrude leftward from the right portion of the inner circumferential line of the outer layer main body 51. The outer layer protrusions 52 are formed in a shape corresponding to the opening P2 of the mounting portion 31. The outer layer protrusions 52 are present in the gap between a pair of ends of the mounting portion 31. The outer layer protrusions 52 are configured to fill the opening P2 of the mounting portion 31. In other words, a portion of the outer layer protrusions 52 contacts the core material 21. Furthermore, another portion of the outer layer protrusions 52 contacts a pair of ends 41c of the mounting portion 31.

[0052] 3. Structure of the Sensor Body 32 The structure of the sensor body 32 will be described with reference to Fig. 7. As described above, the sensor body 32 constitutes a capacitive sensor. The sensor body 32 includes a first conductive layer 61, a sensor insulating layer 62, and a second conductive layer 63.

[0053] The first conductive layer 61 constitutes a detection electrode of the electrostatic sensor. The first conductive layer 61 is formed, for example, from a conductive cloth, a conductive elastomer, or the like. The conductive cloth may be a woven cloth made of warp and weft threads, or a nonwoven fabric. The conductive elastomer is composed of an elastomer as the main component and contains a conductive filler.

[0054] In this embodiment, the first conductive layer 61 has a plurality of through holes 61a. When the first conductive layer 61 is a conductive cloth, the through holes 61a are formed by gaps between the fibers. When the first conductive layer 61 is a conductive elastomer, the through holes 61a are intentionally formed. By forming the through holes 61a in the first conductive layer 61, the first conductive layer 61 has an uneven outer surface. The outer layer main body 51 of the outer layer member 23 fits into the recesses in the outer surface of the first conductive layer 61. In other words, the outer layer main body 51 of the outer layer member 23 engages with the uneven outer surface of the first conductive layer 61 in the planar direction. Note that the first conductive layer 61 may not have through holes 61a, but may have a plurality of blind recesses formed on its outer surface.

[0055] The sensor insulating layer 62 is formed of an insulating material. The sensor insulating layer 62 is formed of, for example, at least one of a resin, an elastomer, and a foam. An example of a resin is polyolefin (ethylene octene). Examples of elastomers are SEBS (a block copolymer of styrene, ethylene, butadiene, and styrene) and EPDM (ethylene propylene diene rubber). Examples of foams are polyurethane foam, polyethylene foam, and EPDM (ethylene propylene diene rubber). The sensor insulating layer 62 is formed of a different material from the mounting portion 31 and from the outer layer member 23. The melting point of the sensor insulating layer 62 is higher than that of the mounting portion 31 and the outer layer member 23.

[0056] The sensor insulating layer 62 is bonded to the inner surface of the first conductive layer 61. The sensor insulating layer 62 and the first conductive layer 61 are bonded by fusing the sensor insulating layer 62 itself. Alternatively, the sensor insulating layer 62 and the first conductive layer 61 may be bonded by an adhesive.

[0057] The outer shape of the sensor insulating layer 62 is larger than the outer shape of the first conductive layer 61. The first conductive layer 61 is disposed in the central region excluding the entire periphery of the outer periphery of the sensor insulating layer 62. In other words, the entire periphery of the outer periphery of the sensor insulating layer 62 is an area 62a where the first conductive layer 61 is not disposed.

[0058] Here, as described above, the outer layer member 23 is bonded to the outer surface of the first conductive layer 61. Furthermore, the outer layer member 23 is bonded to the sensor insulating layer 62 via the multiple through holes 61a of the first conductive layer 61. Furthermore, the outer layer member 23 is directly bonded to a region 62a of the sensor insulating layer 62 where the first conductive layer 61 is not disposed, i.e., the outer peripheral region.

[0059] The outer layer member 23 and the sensor insulating layer 62 may be joined by fusing the outer layer member 23 itself, or by using an adhesive. This joining is the same for the region via the through hole 61 a and the region 62 a where the first conductive layer 61 is not disposed.

[0060] The second conductive layer 63 constitutes a detection electrode or a shield electrode of the electrostatic sensor. Like the first conductive layer 61, the second conductive layer 63 is formed of, for example, a conductive cloth or a conductive elastomer. The second conductive layer 63 may constitute a heater wire in addition to the detection electrode or the shield electrode of the electrostatic sensor. Furthermore, the second conductive layer 63 may be configured to serve both as a detection electrode or a shield electrode of the electrostatic sensor and as a heater wire.

[0061] The second conductive layer 63 is bonded to the inner surface of the sensor insulating layer 62. The second conductive layer 63 and the sensor insulating layer 62 are bonded by fusing the sensor insulating layer 62 itself. Alternatively, the second conductive layer 63 and the sensor insulating layer 62 may be bonded by an adhesive.

[0062] The outer shape of the sensor insulating layer 62 is larger than the outer shape of the second conductive layer 63. The second conductive layer 63 is disposed in the central region of the outer periphery of the sensor insulating layer 62, excluding the entire periphery. In other words, the outer periphery of the sensor insulating layer 62 is a region 62b where the second conductive layer 63 is not disposed along the entire periphery. The outer shape of the sensor insulating layer 62 may be the same as the outer shape of the second conductive layer 63. The region where the second conductive layer 63 is not disposed may be set to any region other than the outer periphery.

[0063] Furthermore, the second conductive layer 63 is disposed in contact with the outer surface of the mounting portion main body 41 of the mounting portion 31. The second conductive layer 63 may be bonded to the mounting portion main body 41, or may be in contact with the mounting portion main body 41 without being bonded.

[0064] In this embodiment, the second conductive layer 63 has a plurality of through holes 63a. When the second conductive layer 63 is a conductive cloth, the through holes 63a are formed by gaps between the fibers. When the second conductive layer 63 is a conductive elastomer, the through holes 63a are intentionally formed. By forming the through holes 63a in the second conductive layer 63, the second conductive layer 63 has an uneven inner surface. The mounting portion main body 41 of the mounting portion 31 fits into the recesses in the outer surface of the second conductive layer 63. In other words, the mounting portion main body 41 of the mounting portion 31 engages with the unevenness on the inner surface of the second conductive layer 63 in the planar direction. Note that the second conductive layer 63 may not have through holes 63a, but may have a plurality of blind recesses formed on the inner surface.

[0065] Here, the mounting portion main body 41 of the mounting portion 31 is bonded to the inner surface of the second conductive layer 63. Furthermore, the mounting portion main body 41 is bonded to the sensor insulating layer 62 via the multiple through holes 63a of the second conductive layer 63. Furthermore, the mounting portion main body 41 is directly bonded to an area 62b of the sensor insulating layer 62 where the second conductive layer 63 is not disposed, i.e., the outer peripheral area.

[0066] The mounting portion main body 41 and the sensor insulating layer 62 may be joined by fusing the mounting portion main body 41 itself, or by using an adhesive. This joining is the same for the region via the through hole 63a and the region 62b where the second conductive layer 63 is not disposed.

[0067] 4. Manufacturing Method of Steering Wheel 10 A manufacturing method of the above-mentioned steering wheel 10 will be described with reference to Figure 8. First, a manufacturing process of the sensor member 22 is performed (S11). In the manufacturing process of the sensor member 22, a sheet-like material (not shown) for the sensor main body 32 is first prepared (S111, material preparation process). The material for the sensor main body 32 is formed, for example, in a flat shape.

[0068] Next, the material of the sensor body 32 is shaped to form the sensor body 32 shown in Fig. 5 (S112, shaping step). Next, the shaped sensor body 32 is placed in a mold, and the mounting portion 31 is molded by injection molding (S113, mounting portion injection molding step). This produces the sensor member 22 in which the sensor body 32 and the mounting portion 31 are integrated, as shown in Fig. 4.

[0069] After the sensor member 22 is manufactured, the opening P2 of the sensor member 22 is widened and the sensor member 22 is attached to the core member 21 (S12, attachment step). The core member 21 and the sensor member 22 are then placed in a mold, and the outer layer member 23 is formed by injection molding (S13, outer layer injection molding step). This integrates the core member 21, the sensor member 22, and the outer layer member 23. In this way, the grip portion 12 is completed.

[0070] 5. Density of the outer layer member 23, mounting portion 31, and sensor insulating layer 62 The density of the outer layer member 23 is preferably lower than that of the mounting portion 31 and lower than that of the sensor insulating layer 62. In this case, the thickness of the mounting portion 31 and the sensor insulating layer 62 can be stabilized, thereby stabilizing the distance between the core material 21 and the sensor main body 32. This improves the detection performance of the sensor main body 32. Furthermore, the thickness of the outer layer member 23 can be made relatively flexible compared to the mounting portion 31 and the sensor insulating layer 62. As a result, a good tactile sensation can be provided.

[0071] Furthermore, it is preferable that the density of the mounting portion 31 is equal to or greater than the density of the sensor insulating layer 62. This stabilizes the thickness of the mounting portion 31, thereby stabilizing the distance between the core material 21 and the sensor main body 32. This improves the detection performance of the sensor main body 32.

[0072] On the other hand, the density of the mounting portion 31 may be lower than the density of the sensor insulating layer 62. In this case, the density of the mounting portion 31, which is relatively thick, is relatively low, making it easier to mount the sensor member 22 on the core material 21.

[0073] 6. Young's modulus of the outer layer member 23, the mounting portion 31, and the sensor insulating layer 62 The Young's modulus of the outer layer member 23 is preferably smaller than that of the mounting portion 31 and smaller than that of the sensor insulating layer 62. In this case, the thickness of the mounting portion 31 and the sensor insulating layer 62 can be stabilized, thereby stabilizing the distance between the core material 21 and the sensor main body 32. This improves the detection performance of the sensor main body 32. Furthermore, the thickness of the outer layer member 23 can be made relatively flexible compared to the mounting portion 31 and the sensor insulating layer 62. As a result, a good tactile sensation can be provided.

[0074] Furthermore, it is preferable that the Young's modulus of the mounting portion 31 is equal to or greater than the Young's modulus of the sensor insulating layer 62. This stabilizes the thickness of the mounting portion 31, thereby stabilizing the distance between the core material 21 and the sensor main body 32. This improves the detection performance of the sensor main body 32.

[0075] On the other hand, the Young's modulus of the mounting portion 31 may be smaller than the Young's modulus of the sensor insulating layer 62. In this case, the mounting portion 31 has a relatively large thickness and a relatively low density, which makes it easier to mount the sensor member 22 on the core material 21.

[0076] 7. Effects of the Configuration of the Sensor Member 22 The sensor member 22 is configured to be attached to the outer surface of the core material 21 extending in a first direction Dir1, which is a direction along a predetermined curve. The sensor member 22 includes a mounting portion 31 formed of an insulating material and configured to be attached to the outer surface of the core material 21, and a sensor main body 32 joined to the outer surface of the mounting portion 31.

[0077] In a cross section SE of the core material 21 that is perpendicular to a center line L1 extending in the first direction Dir1, the mounting portion 31 has an opening P2 in a part of the second direction Dir2, which is the circumferential direction along the outer circumferential lines 21a, 21b, and 21c of the core material 21, and has a pair of end portions 41c for forming the opening P2. Furthermore, the mounting portion 31 has a shape of an inner circumferential line 41b that corresponds to a part of the shape of the outer circumferential lines 21a, 21b, and 21c of the core material 21.

[0078] According to the above configuration, the sensor member 22 is attached to the outer surface of the core material 21, which extends in the first direction Dir1 along a predetermined curve. Because the core material 21 is formed in a shape that extends in the first direction Dir1 along a curve, it is not easy to attach the sensor member 22 to the outer surface of the core material 21.

[0079] However, the sensor member 22 includes a mounting portion 31 in addition to the sensor main body 32. The mounting portion 31 is configured to be mounted on the outer surface of the core material 21. This mounting portion 31 is configured to have an opening in a part of the second direction Dir2, which is the circumferential direction along the outer circumferential lines 21a, 21b, and 21c of the core material 21, in a cross section SE perpendicular to the center line L1 extending in the first direction Dir1. In other words, the mounting portion 31 has a pair of end portions 41c for forming the opening P2. Therefore, because the mounting portion 31 has the opening P2 in the cross section SE, it is easy to mount the mounting portion 31 on the core material 21.

[0080] Furthermore, in the cross section SE, the attachment portion 31 has an inner peripheral line 41b that has a shape that corresponds to part of the shape of the outer peripheral lines 21a, 21b, and 21c of the core material 21. Therefore, when the attachment portion 31 is attached to the core material 21, the attachment portion 31 can be positioned at a desired position relative to the core material 21. As described above, the attachment portion 31 can be easily attached to the core material 21 and can be positioned at a stable position relative to the core material 21. In this way, the attachment portion 31 is configured to improve the ease of attachment to the core material 21.

[0081] The sensor body 32 constituting the sensor member 22 includes at least a first conductive layer 61 and a sensor insulating layer 62, and is bonded to the outer surface of the mounting portion 31. Because the sensor body 32 is bonded to the outer surface of the mounting portion 31, there is no need for the sensor body 32 itself to improve the mountability to the core material 21. Therefore, the sensor member 22 including the mounting portion 31 and the sensor body 32 can be easily mounted to the core material 21.

[0082] Furthermore, since the sensor body 32 is joined to the outer surface of the mounting portion 31, excessive deformation of the sensor body 32 constituting the sensor member 22 can be suppressed when the sensor member 22 is mounted on the core material 21. Therefore, the detection performance of the sensor body 32 can be improved.

[0083] Furthermore, in the cross section SE, the flexural rigidity (EI) of the mounting portion 31 is set to be higher than the flexural rigidity (EI) of the sensor main body 32. In this way, the high flexural rigidity of the mounting portion 31 allows the mounting portion 31 to retain its shape relative to the sensor main body 32. As a result, the shape stability of the sensor member 22 can be ensured compared to the case where only the sensor main body 32 is used.

[0084] Here, the thickness of the sensor main body 32 is thinner than the maximum thickness of the mounting portion 31. With this configuration, as described above, the bending rigidity (EI) of the mounting portion 31 is higher than the bending rigidity (EI) of the sensor main body 32 at the cross section SE.

[0085] Furthermore, the sensor insulating layer 62 is formed from a material different from that of the mounting portion 31. This allows the mounting portion 31 and the sensor insulating layer 62 to be formed from materials suited to their respective purposes.

[0086] Furthermore, in cross section SE, the opening width D1 of the pair of ends 41c of the mounting portion 31 is smaller than the maximum distance D2 between two points on the inner surface of the mounting portion 31. With this configuration, when the sensor member 22 is attached to the core material 21, the opening P2 of the mounting portion 31 is widened. In this way, the mounting portion 31 is configured to be fitted into the core material 21, and is thereby mechanically engaged with the core material 21, thereby maintaining its position.

[0087] Furthermore, the core material 21 has a recess 21d. The mounting portion 31 has a mounting portion protrusion 42 that protrudes inward, and the mounting portion protrusion 42 is configured to fill the recess 21d of the core material 21. With this configuration, the mounting portion 31 is mechanically engaged with the core material 21 more firmly, and is held in position.

[0088] The mounting portion 31 may be joined to the core material 21, or may be in contact with the core material 21 without being joined. Not joining them makes it easier to attach the sensor member 22 to the core material 21. In particular, because the shapes of the mounting portion 31 and the core material 21 allow them to be mechanically engaged with each other and maintain their positions, it is sufficient if they are not joined.

[0089] Furthermore, the melting point of the mounting portion 31 is lower than the lowest melting point of the materials constituting the sensor body 32. This makes it possible to suppress thermal deformation of the sensor body 32 during injection molding of the mounting portion 31. As a result, it is possible to prevent the detection performance of the sensor body 32 from being affected.

[0090] The sensor main body 32 also constitutes a capacitive sensor. The sensor main body 32 includes at least a first conductive layer 61 and a sensor insulating layer 62 bonded to the inner surface of the first conductive layer 61. The sensor main body 32 can output a capacitance equivalent value that changes depending on the distance between the first conductive layer 61 and the occupant's hand. The capacitance equivalent value is output as, for example, a voltage or a current.

[0091] Furthermore, the sensor main body 32 includes a first conductive layer 61, a sensor insulating layer 62 bonded to the inner surface of the first conductive layer 61, and a second conductive layer 63 bonded to the inner surface of the sensor insulating layer 62. The second conductive layer 63 can form another detection electrode for the electrostatic sensor, can form a shield electrode, or can form a heater wire. It can also serve as a combination of these.

[0092] The mounting portion 31 is joined to the sensor insulating layer 62 in a region 62b where the second conductive layer 63 is not disposed. This makes it possible to effectively maintain the positions of the mounting portion 31 and the sensor main body 32.

[0093] Furthermore, the sensor main body 32 has an uneven surface on its inner surface, and the mounting part 31 engages with the uneven surface on the inner surface of the sensor main body 32. In other words, the sensor main body 32 and the mounting part 31 engage with each other in a configuration that has an anchor effect, thereby ensuring the force with which the sensor main body 32 and the mounting part 31 can be held in position.

[0094] In particular, the second conductive layer 63 may have a plurality of through holes 63a, and the mounting portion 31 may be bonded to the sensor insulating layer 62 via the plurality of through holes 63a in the second conductive layer 63. In this case, the positions of the sensor main body 32 and the mounting portion 31 can be more effectively maintained. Furthermore, the bonding between the sensor insulating layer 62 and the mounting portion 31 via the through holes 63a in the second conductive layer 63 ensures positional retention through the anchor effect. In other words, the anchor effect can be more effectively exerted. Furthermore, this is effective when the bonding strength between the mounting portion 31 and the second conductive layer 63 is weaker than the bonding strength between the mounting portion 31 and the sensor insulating layer 62.

[0095] 8. Effects of the manufacturing method of the sensor member 22 In the mounting portion injection molding process, the sensor main body 32 is placed in a mold, and the mounting portion 31 is molded by injection molding, integrating the mounting portion 31 and the sensor main body 32. In this way, the mounting portion 31 and the sensor main body 32 can be integrated together to form the above-described shape of the mounting portion 31. Then, the sensor member 22 can be molded with the mounting portion 31 and the sensor main body 32 integrated together. Therefore, the sensor member 22 having the above-described functions can be easily manufactured.

[0096] Furthermore, when molding the sensor body 32, a planar material for the sensor body 32 is prepared, and the material for the sensor body 32 is shaped to form the sensor body 32. In the mounting portion injection molding process, the shaped sensor body 32 is placed in a mold. In this way, by preforming the sensor body 32 into a shape that is easy to place in a mold, the number of preparation steps required when molding the mounting portion 31 can be reduced.

[0097] 9. Effects of the Configuration of the Grip Section 12 The grip section 12 includes a core material 21 extending in a first direction Dir1, which is a direction along a predetermined curve, a sensor member 22 attached to the outer surface of the core material 21, and an outer layer member 23 covering the outer surface of the sensor member 22. The outer layer member 23 has outer layer protrusions 52 that protrude inward. The outer layer protrusions 52 are located in the gap between the pair of ends 41c of the attachment section 31 and are configured to come into contact with the core material 21.

[0098] Therefore, the outer layer protrusions 52 can restrict the outer layer member 23 from rotating relative to the core material 21 and the sensor member 22. In other words, the outer layer protrusions 52 function to maintain the position of the outer layer member 23 relative to the core material 21 and the sensor member 22.

[0099] The outer layer member 23 may be joined to an area of ​​the sensor insulating layer 62 where the first conductive layer 61 is not disposed. This makes it possible to effectively maintain the positions of the sensor main body 32 and the outer layer member 23.

[0100] Furthermore, the sensor main body 32 has an uneven outer surface, and the outer layer member 23 engages with the uneven outer surface of the sensor main body 32. In other words, the sensor main body 32 and the outer layer member 23 engage with each other in a configuration that has an anchor effect, thereby ensuring the force with which the sensor main body 32 and the outer layer member 23 can be held in position.

[0101] In particular, the first conductive layer 61 may have a plurality of through holes 61a, and the outer layer member 23 may be bonded to the sensor insulating layer 62 via the plurality of through holes 61a in the first conductive layer 61. In this case, the positions of the sensor main body 32 and the outer layer member 23 can be more effectively maintained. Furthermore, bonding between the sensor insulating layer 62 and the outer layer member 23 via the through holes 61a in the first conductive layer 61 ensures positional retention through the anchor effect. In other words, the anchor effect can be more effectively exerted. Furthermore, this is effective when the bonding strength between the outer layer member 23 and the first conductive layer 61 is weaker than the bonding strength between the outer layer member 23 and the sensor insulating layer 62.

[0102] Furthermore, the melting point of the mounting portion 31 is lower than the lowest melting point of the materials constituting the sensor body 32, and the melting point of the outer layer member 23 is lower than the melting point of the mounting portion 31. This makes it possible to suppress thermal deformation of the sensor body 32 when the mounting portion 31 is injection molded. As a result, it is possible to prevent any impact on the detection performance of the sensor body 32. Furthermore, it is possible to suppress thermal deformation of the mounting portion 31 and the sensor body 32 when the outer layer member 23 is injection molded. As a result, it is possible to prevent any impact on the detection performance of the sensor body 32 and the shape retention function of the mounting portion 31.

[0103] 10. Effects of the Manufacturing Method of the Grip Portion 12 In the manufacturing method of the grip portion 12, the unit (21, 22) in which the sensor member 22 is attached to the core material 21 is placed in a mold, and the outer layer member 23 is formed by injection molding. In this way, the core material 21, the sensor member 22, and the outer layer member 23 can be integrated while forming the above-described shape of the outer layer member 23. Therefore, the grip portion 12 of the steering wheel 10 having the above-described functions can be easily manufactured.

[0104] Even if the core material 21 and the sensor member 22 are not joined, by molding the outer layer member 23 by injection molding, the pressure during injection molding can cause the core material 21 to adhere tightly to the sensor member 22.

[0105] By placing the unit (21, 22) consisting of the core material 21 and the sensor member 22 in a mold and molding the outer layer member 23 by injection molding, the outer layer protrusions 52 that constitute the outer layer member 23 can be molded into the opening P2 of the mounting portion 31. Furthermore, the outer layer protrusions 52 of the outer layer member 23 can be brought into contact with the core material 21.

[0106] (Embodiment 2) A method for manufacturing a steering wheel 10 of this embodiment will be described with reference to Figure 9. The configuration of the steering wheel 10 is the same as that of embodiment 1. However, the sensor member 22 is molded from an elastomer. Specifically, the first conductive layer 61 and the second conductive layer 63 that constitute the sensor member 22 are molded from a conductive elastomer. The sensor insulating layer 62 that constitutes the sensor member 22 is molded from an insulating elastomer. The main components of the elastomers may be the same or different.

[0107] First, a manufacturing process of the sensor member 22 is carried out (S21). In the manufacturing process of the sensor member 22, first, the sensor body 32 shown in Fig. 5 is molded by injection molding (S211, sensor body injection molding process).

[0108] Next, the molded sensor body 32 is placed in a mold, and the mounting portion 31 is molded by injection molding (S212, mounting portion injection molding step). As a result, the sensor member 22 in which the sensor body 32 and the mounting portion 31 are integrated is manufactured, as shown in FIG.

[0109] After the sensor member 22 is manufactured, the opening P2 of the sensor member 22 is widened and the sensor member 22 is attached to the core material 21 (S22, attachment step). Next, the unit consisting of the core material 21 and the sensor member 22 is placed in a mold, and the outer layer member 23 is formed by injection molding (S23, outer layer injection molding step). This integrates the core material 21, the sensor member 22, and the outer layer member 23. In this way, the grip portion 12 is completed.

[0110] According to this embodiment, the sensor member 22 shown in Fig. 5 can be manufactured in one process, and the reduction in the number of manufacturing processes can reduce costs.

[0111] (Embodiment 3) The grip portion 12 of the steering wheel 10 of this embodiment will be described with reference to Figure 10. In embodiment 1, the distance between the pair of end portions 41c of the mounting portion main body 41 constituting the mounting portion 31 increases toward the inside. In this embodiment, the distance between the pair of end portions 41c is constant regardless of the radial position.

[0112] In this case, the thickness of the mounting portion main body 41 constituting the mounting portion 31 is configured to become thinner in the cross section SE as it moves away from the pair of end portions 41c in the circumferential direction. In other words, the end of the pair of end portions 41c on the opening P2 side is formed to be the thickest. Note that the separation distance between the pair of end portions 41c is not limited to being constant, and any thickness relationship may be used. For example, the separation distance between the pair of end portions 41c may become smaller as it moves inward. In other words, the width of the opening P2 decreases inward.

[0113] The mounting portion 31 has low rigidity near the pair of ends 41c. Therefore, the shape retention strength near the pair of ends 41c is lower than other portions. Furthermore, the mounting portion 31, which is integrated with the sensor main body 32, widens the opening P2 when mounted on the core material 21. This is detrimental to the shape retention of the pair of ends 41c of the mounting portion 31. However, by making the pair of ends 41c of the mounting portion 31 thicker toward the ends as described above, the shape retention strength of the pair of ends 41c is increased. In other words, even if the mounting portion 31 has the above configuration and requires movement when mounted on the core material 21, the shape retention strength of the mounting portion 31 can be sufficiently ensured.

[0114] (Embodiment 4) The grip portion 12 of the steering wheel 10 of this embodiment will be described with reference to Figure 11. In embodiment 3, the thickness of the mounting portion main body 41 constituting the mounting portion 31 is configured to become thinner as it moves away from the pair of end portions 41c in the circumferential direction in the cross section SE. In this embodiment, the thickness of the mounting portion main body 41 constituting the mounting portion 31 is configured to become thicker as it moves away from the pair of end portions 41c in the circumferential direction in the cross section SE.

[0115] In particular, in cross section SE, the pair of end portions 41c are spaced apart from the outer circumferential line 21c of the core material 21. The pair of end portions 41c have inner surfaces 41c1 at positions spaced apart from the core material 21. The inner surfaces 41c1 are formed, for example, in a curved, concave shape or a straight shape. Therefore, the outer circumferential line 21c of the core material 21 faces the inner surfaces 41c1 of the pair of end portions 41c of the mounting portion main body 41 of the mounting portion 31. In other words, when the sensor member 22 is mounted on the core material 21, a space having a width greater than the width of the opening P2 is formed inside the opening P2.

[0116] By injection molding the outer layer member 23, the outer layer protrusions 52 are formed in the space formed by the pair of end portions 41c of the mounting portion main body 41 and the core material 21. Therefore, the outer layer protrusions 52 come into contact with the inner surfaces 41c1 of the pair of end portions 41c of the mounting portion main body 41.

[0117] The pair of end portions 41c of the attachment portion main body 41 are formed thinner toward the end portions, which makes it easier to attach the sensor member 22 to the core material 21. Furthermore, the outer layer protrusions 52 come into contact with the inner surfaces 41c1 of the pair of end portions 41c of the sensor member 22, thereby more effectively restricting rotation of the outer layer member 23 relative to the core material 21 and the sensor member 22. In other words, the outer layer protrusions 52 effectively function to maintain the position of the outer layer member 23 relative to the core material 21 and the sensor member 22.

[0118] Fifth Embodiment The grip portion 12 of the steering wheel 10 of the fifth embodiment will be described with reference to Fig. 12. In the first embodiment, the sensor main body 32 is C-shaped or U-shaped in cross section SE and is configured to correspond to most of the outer circumferential line 41a of the mounting portion main body 41.

[0119] In this embodiment, the sensor main body 32 is disposed on only a portion of the circumferential direction of the outer circumferential line 41a of the attachment main body 41. The sensor main body 32 is composed of multiple members, one of which has a circumferential width corresponding to an upper portion of the outer circumferential line 41a of the attachment main body 41 and is joined to that portion. The other has a circumferential width corresponding to a lower portion of the attachment main body 41 and is joined to that portion. However, the number of sensor main bodies 32 can be set arbitrarily, and the circumferential width can also be set arbitrarily. Furthermore, the sensor main body 32 may have a circumferential width corresponding to only the upper portion of the outer circumferential line 41a of the attachment main body 41 and be joined to that portion. Alternatively, the sensor main body 32 may be joined to only the lower portion.

[0120] The mounting portion 31 exhibits a shape-retaining function, and the sensor member 22 only needs to be joined to the mounting portion 31, so the above-described configuration can be adopted.

[0121] Sixth Embodiment The configuration of the sensor main body 32 in a steering wheel 10 according to a sixth embodiment will be described with reference to Fig. 13. In this embodiment, the sensor main body 32 has a plurality of through holes 32a. In detail, the first conductive layer 61 constituting the sensor main body 32 has a plurality of through holes 61a, the sensor insulating layer 62 has a plurality of through holes 62c, and the second conductive layer 63 has a plurality of through holes 63a. The through holes 61a, 62c, and 63a are connected to each other.

[0122] The outer layer member 23 is joined to the mounting portion 31 via a plurality of through holes 32a in the sensor main body 32. In Fig. 13, the outer layer member 23 is configured to fit into the through holes 32a, but the mounting portion 31 may also be configured to fit into the through holes 32a. Alternatively, the outer layer member 23 and the mounting portion 31 may each fit into the through holes 32a.

[0123] By joining the mounting portion 31 and the outer layer member 23, it is possible to reliably maintain the positions of the sensor main body 32 and the outer layer member 23. Furthermore, by joining the mounting portion 31 and the outer layer member 23 via the through-hole 32a of the sensor main body 32, it is possible to ensure position-maintaining force due to the anchor effect.

[0124] Seventh Embodiment A steering wheel 10 according to a seventh embodiment will be described with reference to Fig. 14. In this embodiment, the grip portion 12 of the steering wheel 10 includes a core member 21, a sensor member 22, and an outer layer member 23, similar to the first embodiment.

[0125] In embodiment 1, the sensor member 22 is arranged over the entire length of the grip portion 12 in the first direction Dir1, and further, the mounting portion 31 and the sensor main body 32 that constitute the sensor member 22 are also arranged over the entire length of the grip portion 12 in the first direction Dir1.

[0126] In this embodiment, the mounting portion 31 constituting the sensor member 22 is disposed over the entire length of the grip portion 12 in the first direction Dir1. On the other hand, the sensor main body 32 constituting the sensor member 22 is disposed in the hatched area in Fig. 14, i.e., only a part of the mounting portion 31 in the first direction Dir1. In Fig. 14, the sensor main body 32 is disposed in the grip portion 12 except for the upper portion, i.e., in the left, right, and lower portions.

[0127] However, the location where the sensor main body 32 is disposed may be arbitrary. For example, the sensor main body 32 may be divided into multiple locations in the first direction Dir1. For example, the sensor main body 32 may be disposed independently on the left and right sides of the grip portion 12. Furthermore, the sensor main body 32 may be disposed independently on the front surface (front side) and back surface (rear side) of the grip portion 12.

[0128] 14, the mounting portion 31 constituting the sensor member 22 is disposed around the entire circumference of the grip portion 12, but the mounting portion 31 may be disposed only in a portion of the first direction Dir1 of the grip portion 12. In this case, the mounting portion 31 may be disposed, for example, in the hatched area in FIG. 14, i.e., only in a portion of the first direction Dir1. Furthermore, the mounting portion 31 is not limited to the hatched area in FIG. 14, and may be divided and disposed at multiple locations in the first direction Dir1.

[0129] When the mounting portion 31 is disposed in only a portion of the grip portion 12 in the first direction Dir1, the sensor main body 32 constituting the sensor member 22 may be disposed over the entire length of the mounting portion 31, having the same length in the first direction Dir1 as the mounting portion 31. The sensor main body 32 may also be disposed in only a portion of the mounting portion 31 in the first direction Dir1. For example, when the mounting portion 31 is disposed in a portion excluding the upper portion of the grip portion 12, the sensor main body 32 may be disposed independently on the left and right portions of the mounting portion 31.

[0130] In addition, when the mounting portion 31 is positioned only in a part of the first direction Dir1 of the grip portion 12, the core material 21 may be present in the part where the mounting portion 31 is not positioned, or the outer layer member 23 may be present.

Claims

1. A sensor element (22) comprising a core material (21) extending in a first direction (Dir1) that is a direction along a predetermined curve; a sensor element (22) attached to the outer surface of the core material; and an outer layer member (23) that covers the outer surface of the sensor element, wherein the sensor element comprises: an attachment portion (31) formed of an insulating material and configured to be attached to the outer surface of the core material; and a sensor body (32) joined to the outer surface of the attachment portion, wherein the attachment portion has an opening (P2) in a part of a second direction (Dir2) that is a circumferential direction along the outer circumferential line (21a, 21b, 21c) of the core material in a cross section (SE) perpendicular to a center line (L1) of the core material that extends in the first direction, and has a pair of end portions (41c) for forming the opening, and has an inner circumferential line (41b) shape that corresponds to a part of the shape of the outer circumferential line (21a, 21b, 21c) of the core material, The outer layer member has an outer layer protrusion (52) that protrudes inward, and the outer layer protrusion is present in the gap between the pair of ends of the mounting portion and contacts the core material.

2. The steering wheel according to claim 1, wherein in a cross section of the core material perpendicular to a center line extending in the first direction, the mounting portion has a bending rigidity higher than that of the sensor body.

3. The steering wheel according to claim 2, wherein the thickness of the sensor body is thinner than the maximum thickness of the mounting portion.

4. A steering wheel as claimed in any one of claims 1 to 3, wherein in a cross section perpendicular to a center line extending in the first direction in the core material, the opening width (D1) of the pair of ends of the mounting portion is smaller than the maximum distance (D2) between two points on the outer surface of the core material.

5. A steering wheel according to any one of claims 1 to 3, wherein the outer layer protrusions contact the inner surfaces of the pair of ends of the sensor member.

6. A steering wheel as claimed in any one of claims 1 to 3, wherein the sensor body comprises: a first conductive layer (61); a sensor insulating layer (62) bonded to the inner surface of the first conductive layer; and a second conductive layer (63) bonded to the inner surface of the sensor insulating layer.

7. A steering wheel as claimed in any one of claims 1 to 3, wherein the sensor body comprises a first conductive layer (61) and a sensor insulating layer (62) joined to the inner surface of the first conductive layer, and the outer layer member is joined to an area of ​​the sensor insulating layer where the first conductive layer is not located.

8. A steering wheel as claimed in any one of claims 1 to 3, wherein the sensor body comprises: a first conductive layer (61) having a plurality of through holes (61a); and a sensor insulating layer (62) joined to the inner surface of the first conductive layer; and the outer layer member is joined to the sensor insulating layer via the plurality of through holes in the first conductive layer.

9. A steering wheel as claimed in any one of claims 1 to 3, wherein the sensor body has a plurality of through holes (61a, 63a), and the outer layer member is joined to the mounting portion via the plurality of through holes of the sensor body.

10. A steering wheel according to any one of claims 1 to 3, wherein the sensor body has an uneven outer surface, and the outer layer member engages with the uneven outer surface of the sensor body.

11. A steering wheel as claimed in any one of claims 1 to 3, wherein the melting point of the mounting portion is lower than the lowest melting point of the materials constituting the sensor body, and the melting point of the outer layer material is lower than the melting point of the mounting portion.

12. A steering wheel as claimed in any one of claims 1 to 3, wherein the core material has a recess (21d), the mounting portion has a mounting portion protrusion (42) that protrudes inward, and the mounting portion protrusion fills the recess of the core material.

13. A steering wheel according to any one of claims 1 to 3, wherein the sensor main body is provided with a sensor insulating layer (62), and the density of the outer layer member is lower than the density of the mounting portion and lower than the density of the sensor insulating layer.

14. A steering wheel according to any one of claims 1 to 3, wherein the sensor main body is provided with a sensor insulating layer (62), and the Young's modulus of the outer layer member is smaller than the Young's modulus of the mounting portion and is also smaller than the Young's modulus of the sensor insulating layer.

15. A steering wheel as set forth in any one of claims 1 to 3, wherein the thickness of the mounting portion in a cross section perpendicular to the center line of the core material extending in the first direction is configured to increase with increasing distance from the pair of ends in the circumferential direction.

16. A steering wheel as set forth in any one of claims 1 to 3, wherein the thickness of the mounting portion in a cross section perpendicular to the center line of the core material extending in the first direction is configured to decrease with increasing distance from the pair of ends in the circumferential direction.

17. A steering wheel according to any one of claims 1 to 3, wherein the sensor body is formed in a sheet shape and has no notches on the outer periphery.

18. A steering wheel according to any one of claims 1 to 3, wherein the mounting portion is in contact with the core material without being joined thereto.

19. A steering wheel as claimed in any one of claims 1 to 3, wherein the sensor body is provided with a sensor insulating layer (62), and the mounting portion, the sensor insulating layer and the outer layer member are formed from at least one of resin, elastomer and foam.

20. A method for manufacturing a steering wheel as claimed in any one of claims 1 to 3, comprising the steps of: attaching the sensor member to the core material (S12, S22); and placing the unit in which the sensor member is attached to the core material in a mold, molding the outer layer member by injection molding, and integrating the core material, the sensor member, and the outer layer member (S13, S23).

21. A method for manufacturing a steering wheel as described in claim 20, further comprising steps (S113, S212) of placing the sensor main body in a mold, molding the mounting portion by injection molding, and integrating the mounting portion and the sensor main body, wherein in the steps (S12, S22) of mounting the sensor member, the sensor member integrated in the steps (S113, S212) of molding the mounting portion is mounted to the core material.

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