Steering wheel

Abstract

To provide a steering wheel that can reduce the occurrence of quality variations due to differences in workers and reduce the occurrence of appearance defects due to functional parts such as sensor parts.SOLUTION: In a steering wheel (1), a rim portion (10) has a rim base material portion (20), a covering portion (30) that covers the rim base material portion (20), and a sheet-like functional component (40) provided between the rim base material portion (20) and the covering portion (30). The functional component (40) has a first side edge portion (46) that includes one side edge in the width direction, and a second side edge portion (47) that includes the other side edge in the width direction. When the cross section of the rim portion (10) is viewed, the rim base material portion (20) has a side edge mounting portion (27) on which the first side edge portion (46) and the second side edge portion (47) of the functional component (40) are mounted, and the outer peripheral surface of the side edge mounting portion (27) is formed with a curvature smaller than that of the outer surface formed by the covering portion (30) correspondingly to the formation area of the side edge mounting portion (27).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a steering wheel for a motor vehicle. [Background technology]

[0002] JP 2021-154850 A (Patent Document 1) describes a steering wheel equipped with a sensor component that detects the driver's grip. The steering wheel of Patent Document 1 has an annular rim portion (ring portion), a boss portion disposed in the center of the rim portion, and spoke portions connecting the rim portion and the boss portion.

[0003] The rim portion of the steering wheel has a core portion, a base material portion that encases the core portion, a covering portion that is disposed on the surface (outer surface) side of the rim portion, and a sensor component that is disposed between the base material portion and the covering portion. In this case, the base material portion is integrally formed with the core portion by injection molding a synthetic resin such as urethane around the core portion. The covering portion is generally formed of a skin material such as natural leather or synthetic leather.

[0004] The rim portion of Patent Document 1 is formed, for example, by manually attaching a sensor component to the surface of a base material, and then wrapping a covering portion around the sensor component to cover the base material and the sensor component from the outside with the covering portion.

[0005] According to the steering wheel of Patent Document 1, when the driver's hands grip the rim of the steering wheel or approach as if to grip the rim, the capacitance of the sensor component increases, and the detection circuit detects this increase in capacitance, thereby making it possible to detect the driver's grip. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2021-154850 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the steering wheel of Patent Document 1, the rim portion is formed by an operator manually wrapping the covering portion around the base material portion and the sensor component, as described above. On the other hand, the rim of the steering wheel may be formed, for example, by setting the steering wheel before the covering portion is disposed (i.e., the steering wheel with the sensor components disposed on the surface of the base material portion of the rim portion) in a mold and molding (insert molding) a soft synthetic resin such as polyurethane that forms the covering portion in the mold. By molding the covering portion in this way, the steering wheel can be manufactured more efficiently than, for example, wrapping the covering portion by hand. Also, it is possible to reduce the occurrence of quality variations due to differences in workers.

[0008] However, when forming the covering portion by molding synthetic resin onto the outside of the base material and the sensor component, sometimes a part of the sensor component (for example, a part that forms the insulating portion of the sensor component) peels off from the base material of the rim portion between the time when the steering wheel is set in the mold and the time when the mold is filled with synthetic resin during the molding process.

[0009] When molding such a covering, if the sensor component peels off before the synthetic resin is filled into the mold, a part of the sensor component may be exposed on the outer surface of the molded covering, or even if the sensor component is not exposed, an unnatural convex or protruding part may be formed on the outer surface of the covering, which may result in a decrease in the quality and yield of the steering wheel.

[0010] Furthermore, in order to prevent the above-mentioned sensor components from appearing and the appearance defects such as the formation of unnatural protrusions or projections from occurring in the rim portion, it is necessary to take various preventive measures or treatments, change the molding process of the covering portion, etc. This can lead to an increase in manufacturing costs and a complicated manufacturing process.

[0011] The present invention has been made in consideration of the above-mentioned problems in the conventional art, and its object is to provide a steering wheel that is less susceptible to quality variations due to differences in workers and that is less susceptible to appearance defects due to functional components such as sensor components. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the steering wheel provided by the present invention has at least an annular rim portion, and a cross section perpendicular to the circumferential direction of the rim portion is formed to be circular or approximately circular, the rim portion having a rim base material portion, a covering portion that covers the rim base material portion from the outside, and a sheet-like functional component arranged between the rim base material portion and the covering portion, the functional component having a first side edge portion including one side edge in the width direction of the functional component, and a second side edge portion including the other side edge in the width direction of the functional component, when the cross section of the rim portion is viewed, the rim base material portion has a side edge mounting portion on which the first side edge and the second side edge of the functional component are arranged, and the outer circumferential surface of the side edge mounting portion is formed with a curvature smaller than the curvature of the outer surface formed by the covering portion corresponding to the formation area of ​​the side edge mounting portion.

[0013] In the steering wheel of the present invention, when the cross section of the rim portion is viewed, it is preferable that the rim base material portion has a curved portion formed in an arc shape or an approximately arc shape, and a flat portion formed in a straight line, and when the cross section of the rim portion is viewed, a part of the functional component is arranged on the curved portion of the rim base material portion, and the first side edge portion and the second side edge portion of the functional component are arranged on the flat portion of the rim base material portion.

[0014] In this case, the covering portion has a first covering portion provided corresponding to at least a portion of the portion where the curved portion of the rim portion is formed, and a second covering portion provided corresponding to the portion where the flat portion of the rim portion is formed and formed thicker than the first covering portion, and when viewing the cross section of the rim portion, it is preferable that the second covering portion has a shape that makes the cross section of the rim portion circular or approximately circular.

[0015] In the present invention, the side edge mounting portion of the rim portion is preferably provided on an inner periphery of the annular rim portion. Furthermore, the covering portion is preferably made of an elastic synthetic resin. Effect of the Invention

[0016] According to the steering wheel of the present invention, since the covering portion is formed by molding synthetic resin, it is possible to prevent quality variations due to differences in workers. Also, since the first side edge portion and the second side edge portion of the functional part are arranged on the flat surface portion of the rim base material portion, it is possible to prevent appearance defects due to the functional part. [Brief description of the drawings]

[0017] [Figure 1] 1 is a front view showing a schematic diagram of a steering wheel according to an embodiment of the present invention; [Diagram 2] 2 is a cross-sectional view showing a schematic cross section taken along line II-II shown in FIG. 1. [Diagram 3] 3 is an enlarged cross-sectional view showing a part of the cross section shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] BEST MODE FOR CARRYING OUT THE PRESENT DISCLOSURE Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. EXAMPLES

[0019] Fig. 1 is a front view showing a steering wheel according to the present embodiment, Fig. 2 is a cross-sectional view showing a cross section taken along line II-II shown in Fig. 1, Fig. 3 is an enlarged cross-sectional view showing a cross section within the dashed line shown in Fig. 2.

[0020] In the following description, the terms "up-down" and "left-right" refer to directions perpendicular to the axial direction of the steering shaft on which the steering wheel is mounted, and which refer to the up-down direction (the direction connecting the 0 o'clock and 6 o'clock parts of the rim part on the page in Figure 1) and the left-right direction (the direction connecting the 9 o'clock and 3 o'clock parts of the rim part on the page in Figure 1) of the steering wheel when viewed from the driver's side with the steering wheel held in neutral position.

[0021] In addition, "forward" refers to the direction parallel to the axial direction of the steering shaft, toward the front side of the steering wheel when viewed from the driver's side (the front side of the page in FIG. 1), and "rearward" refers to the direction toward the rear side of the steering wheel (the rear side of the page in FIG. 1).

[0022] The steering wheel 1 of this embodiment has a steering body 2, a steering pad 3 arranged on the occupant-facing surface (front surface) of the steering body 2 facing the driver and housing an airbag module therein, a finisher 4 arranged to extend downward and to both the left and right sides from the steering pad 3, and a lower cover (not shown) that covers the back surface (rear surface) of the steering body 2 opposite the occupant-facing surface.

[0023] The steering body 2 has an annular rim portion 10 that is gripped by the driver, a boss portion (not shown) that is disposed in the center of the rim portion 10 and supports the steering pad 3, and three spoke portions (not shown) that connect the rim portion 10 and the boss portion. Note that since the main feature of the present invention is the rim portion 10 of the steering wheel 1, the following description will focus mainly on the rim portion 10.

[0024] The rim portion 10 of this embodiment has a shape such that when viewed in a cross section perpendicular to the circumferential direction of the rim portion 10 (see FIG. 2), the cross section of the rim portion 10 is circular (a perfect circle). The cross section of the rim portion 10 may be formed to be approximately circular. "Approximately circular" means a shape close to a circle, such as an ellipse or an oval.

[0025] The rim portion 10 of this embodiment comprises a rim base material portion 20 formed in an annular shape along the circumferential direction of the rim portion 10, a covering portion 30 attached to the rim base material portion 20 so as to cover the rim base material portion 20 from the outside, and a sensor component 40 (also called a sensor mat) arranged between the rim base material portion 20 and the covering portion 30 (see Figure 2).In this case, the sensor component 40 is arranged with its inner surface in contact with the rim base material portion 20 and its outer surface in contact with the covering portion (outer resin portion) 30.

[0026] When viewed in the cross section (Figure 2), the rim base material portion 20 has a rim core metal portion 21 which forms the core material, and a protective portion (inner resin portion) 22 which covers the rim core metal portion 21. The rim core metal portion 21 is arranged in the centre of the rim portion 10 in the cross section, and is formed in a roughly U-shape from a metal such as an alloy. The rim core metal portion 21 is arranged continuously around the entire circumference of the rim portion 10 in the circumferential direction of the annular rim portion 10.

[0027] The protective part 22 of the rim base material part 20 is formed on the outside of the rim core metal part 21 so as to encase the rim core metal part 21 inward. The protective part 22 is made of a soft synthetic resin such as polyurethane resin. Note that in the present invention, there are no particular limitations on the materials of the rim core metal part 21 and the protective part 22, and the protective part 22 may be made of a hard synthetic resin such as polypropylene or ABS.

[0028] The outer peripheral surface of the rim base material portion 20 (i.e. the outer peripheral surface of the protective portion 22) has a curved surface portion 26 formed in an arc shape and a flat surface portion 27 formed in a straight line when viewed in the cross section (FIG. 2). The curved surface portion 26 of the rim base material portion 20 may be formed in an approximately arc shape that is close to an arc shape. For example, when viewing the steering wheel 1 shown in FIG. 1, the annular rim portion 10 has an inner peripheral portion 11 on the inside close to the steering pad 3 and an outer peripheral portion 12 away from the steering pad 3.

[0029] In this case, the flat surface portion 27 of the rim base material portion 20 is provided on the inner periphery 11 of the rim portion 10, and a first side edge portion 46 and a second side edge portion 47, described below, on the left and right sides of the sensor component 40 are arranged on the flat surface portion 27 provided on this inner periphery 11. In other words, when looking at the cross section of the rim base material portion 20 (Figure 2), the rim base material portion 20 has a side edge mounting portion 27 on which the first side edge portion 46 and second side edge portion 47 of the sensor component 40 are arranged, and this side edge mounting portion 27 is formed by the flat surface portion 27 of the rim base material portion 20.

[0030] The formation area 28 of the flat surface portion (side edge mounting portion) 27 in the rim base material portion 20 is provided so that the range of the central angle of the rim portion 10, which is circular, is 30° or more and 90° or less in the cross section (FIG. 2), preferably 45° or more and 80° or less. By providing the formation area 28 of the flat surface portion 27 in a range where the central angle is 30° or more, the left and right first side edge portions 46 and second side edge portions 47 of the sensor component 40 can be stably arranged on the flat surface portion 27 of the rim base material portion 20. By providing the formation area 28 of the flat surface portion 27 in a range where the central angle is 90° or less, the formation area 28 of the curved surface portion 26 in the rim base material portion 20 can be stably secured, and the function of the sensor component 40 attached to the rim base material portion 20 can be stably exerted.

[0031] The covering portion 30 is arranged so as to cover the rim base material portion 20 from the outside, and forms the outer surface of the rim portion 10. The covering portion 30 is formed from a soft synthetic resin having elasticity, such as polyurethane resin. The covering portion 30 is formed by performing insert molding in a state where the rim portion 10 in which the sensor component 40 is attached to the rim base material portion 20 (i.e., the rim portion 10 before the covering portion 30 is formed) is set in a mold. Note that in the present invention, the material of the covering portion 30 is not particularly limited. The covering portion 30 may be formed from a hard synthetic resin, such as polypropylene or ABS.

[0032] The covering portion 30 has a first covering portion 31 provided in correspondence with the area where the curved portion 26 of the rim base material portion 20 is formed in the cross section (Figure 2) of the rim portion 10, and a second covering portion 32 provided in correspondence with the area where the flat portion 27 of the rim base material portion 20 is formed. Here, the first covering portion 31 and the second covering portion 32 being provided in correspondence with the areas where the curved portion 26 and the flat portion 27 are formed, respectively, means that the first covering portion 31 and the second covering portion 32 are provided in the same area in the cross section (Figure 2) as the areas where the curved portion 26 and the flat portion 27 are formed.

[0033] The first covering portion 31 is provided with a constant thickness on the outside of the curved portion 26 of the rim base material portion 20. Note that in the present invention, the thickness of the covering portion 30 (the first covering portion 31 and the second covering portion 32) refers to the distance between the inner and outer circumferential surfaces of the covering portion 30 when, for example, a cross section perpendicular to the circumferential direction of the rim portion 10 is viewed.

[0034] The second covering portion 32 is provided on the outside of the flat portion 27 of the rim base material portion 20. The second covering portion 32 is formed to be thicker than the first covering portion 31 in the cross section of the rim portion 10 (FIG. 2). The second covering portion 32 also has a shape that forms the cross section of the rim portion 10 into a circular (or approximately circular) shape. In other words, the second covering portion 32 is formed such that the thickness of the second covering portion 32 is changed in the circumferential direction of the covering portion 30 in the cross section of the rim portion 10 so as to compensate for the change in thickness of the rim base material portion 20 caused by the provision of the flat portion 27 on the rim base material portion 20.

[0035] For this reason, the outer peripheral surface of the flat portion (side edge mounting portion) 27 of the rim base material portion 20 is formed with a curvature smaller than the curvature of the outer surface formed by the second covering portion 32. In this case, the outer peripheral surface of the flat portion 27 being formed with a curvature smaller than the curvature of the outer surface of the second covering portion 32 includes a case where the outer peripheral surface of the flat portion 27 is formed as a flat surface with a curvature of zero, and a case where the outer peripheral surface of the flat portion 27 is formed as a curved surface that curves with a larger radius of curvature than the outer surface of the second covering portion 32. In addition, the outer surface of the second covering portion 32 is also the outer surface of the rim portion 10.

[0036] The sensor component 40 is disposed at a position between the rim base material portion 20 and the covering portion 30 so as to be wrapped around the rim base material portion 20. The sensor component 40 is formed in the shape of a long, thin sheet in the circumferential direction of the annular rim portion 10, and is installed along the circumferential direction of the rim portion 10 over the entire or nearly entire circumference of the rim portion 10. The sensor component 40 has an inner surface in contact with the rim base material portion 20 and an outer surface in contact with the covering portion 30.

[0037] In the following description of the sensor component 40, the direction along the circumferential direction of the annular rim portion 10 of the sensor component 40 is defined as the length direction of the sensor component 40. The direction perpendicular to the inner and outer surfaces of the sensor component 40 is defined as the thickness direction of the sensor component 40. The direction perpendicular to the length direction and thickness direction of the sensor component 40 is defined as the width direction of the sensor component 40. In this case, the width direction of the sensor component 40 is the direction along the circumferential direction of the covering portion 30 in the cross section of the rim portion 10 shown in FIG. 2 when the sensor component 40 is attached to the rim base material portion 20.

[0038] As shown in FIG. 3, the sensor component 40 has a base portion 41 formed of an insulator (dielectric), a sensor electrode 42 provided on the outer surface side of the base portion 41 (the side closer to the covering portion 30), and a guard electrode 43 provided on the inner surface side of the base portion 41 (the side closer to the rim substrate portion 20).

[0039] The sensor component 40 is electrically connected to a sensor control unit (not shown) installed in the steering body 2, and this sensor control unit is capable of determining whether or not the driver's hands are gripping the rim portion 10 of the steering wheel. The sensor control unit may also be provided so as to be capable of detecting that the driver's hands have approached the rim portion 10 so as to grip it.

[0040] The base portion 41 of the sensor component 40 is disposed between the sensor electrode 42 and the guard electrode 43, and is formed integrally with the sensor electrode 42 and the guard electrode 43. The sensor electrode 42 and the guard electrode 43 are each formed from conductive cloth made of plated synthetic fiber.

[0041] The sensor electrode 42 is bonded to the outer peripheral surface of the base portion 41. When viewing a cross section of the rim portion 10, as shown in Fig. 3, the sensor electrode 42 is formed so that its circumferential length (width direction of the sensor component 40) in the cross section is shorter than that of the base portion 41. The guard electrode 43 is bonded to the inner peripheral surface of the base portion 41. When viewing a cross section of the rim portion 10, as shown in Fig. 3, the guard electrode 43 is formed so that its circumferential length in the cross section is longer than that of the sensor electrode 42 and shorter than that of the base portion 41.

[0042] The sensor electrode 42 and the guard electrode 43 of the sensor component 40 are not particularly limited in material or structure as long as they are conductive, and may be formed using, for example, a metal wire. The sensor electrode 42 and the guard electrode 43 may be attached to the base portion 41 by, for example, sewing.

[0043] The sensor component 40 has a first side edge (left side edge) 46 including one side edge (e.g., the left side) in the width direction of the sensor component 40, and a second side edge (right side edge) 47 including the other side edge (e.g., the right side) in the width direction. The first side edge 46 and the second side edge 47 of the sensor component 40 include at least a portion formed by stacking three layers of the guard electrode 43, the base portion 41, and the sensor electrode 42 of the sensor component 40. The first side edge 46 and the second side edge 47 also include a portion formed only by the base portion 41.

[0044] The sensor component 40 is attached to the outer peripheral surface of the rim base material portion 20 so as to encase the rim base material portion 20. In this case, the sensor component 40 is attached to the rim base material portion 20 so that, when viewed in cross section of the rim portion 10 (FIG. 2), it covers the entire surface of the curved surface portion 26 of the rim base material portion 20, and at least a part of the first side edge portion 46 and at least a part of the second side edge portion 47 of the sensor component 40 are positioned on the flat surface portion 27 of the rim base material portion 20. In this case, it is preferable that the first side edge portion 46 and the second side edge portion 47 of the sensor component 40 are attached so that the portion where the three layers of the guard electrode 43, the base portion 41, and the sensor electrode 42 of the sensor component 40 are overlapped is positioned on the flat surface portion 27 of the rim base material portion 20.

[0045] By arranging the first side edge 46 and second side edge 47 of the sensor component 40 on the flat surface portion 27 of the rim base material portion 20 in this way, when the sensor component 40 is attached to the rim base material portion 20, the force (reaction force) that causes the first side edge 46 and second side edge 47 of the sensor component 40 to move away from the rim base material portion 20 and return can be reduced, compared to when the first side edge 46 and second side edge 47 are arranged on the curved surface portion 26. This makes it possible to make the first side edge 46 and second side edge 47 of the sensor component 40 less likely to peel off from the outer circumferential surface of the rim base material portion 20.

[0046] Next, a method for forming the rim portion 10 of the steering wheel 1 of this embodiment will be described. To form the rim portion 10, first the process of producing the rim base material portion 20 is carried out. In the process of producing the rim base material portion 20, a rim core metal portion 21 formed in a prescribed shape is prepared, and the rim core metal portion 21 is set in a mold for forming the protective portion 22. Next, the mold in which the rim core metal portion 21 is set is used to mold (e.g. injection molding) a soft synthetic resin. This produces a ring-shaped rim base material portion 20 in which the rim core metal portion 21 is enclosed inside the protective portion 22. A flat portion 27 is formed on the inner periphery 11 of the rim base material portion 20 produced at this time.

[0047] Next, a process is performed in which the sensor component 40 is attached to the obtained rim base material portion 20. In this process, for example, an operator manually applies adhesive to the rim base material portion 20, and then the sensor component 40 is attached to the annular rim base material portion 20 with the guard electrode 43 facing the rim base material portion 20.

[0048] In this process, the adhesive is applied to the surface of the rim base material portion 20 to which the sensor component 40 will be attached. At this time, because the curved portion 26 and the flat portion 27 are formed on the outer peripheral surface of the rim base material portion 20, the worker can easily grasp the boundary between the curved portion 26 and the flat portion 27 by, for example, touching the rim base material portion 20. Therefore, by using the boundary between the curved portion 26 and the flat portion 27 as a guide, the worker can easily apply an appropriate amount of adhesive to the outer peripheral surface of the rim base material portion 20.

[0049] Furthermore, the sensor component 40 is affixed to the rim base material portion 20 so as to cover the curved surface portion 26 of the rim base material portion 20 in the width direction of the sensor component 40, and so that a first side edge portion 46 and a second side edge portion 47 of the sensor component 40 are disposed on the flat surface portion 27 of the rim base material portion 20. Furthermore, the sensor component 40 is affixed to the entire or nearly entire circumference of the rim base material portion 20, which is formed in an annular shape, in the length direction of the sensor component 40.

[0050] The rim base material portion 20 with the sensor component 40 attached thereto is then set in a mold for molding the covering portion 30. At this time, the first side edge portion 46 and the second side edge portion 47 of the sensor component 40 are adhered to the flat portion 27, not the curved portion 26, of the rim base material portion 20, and are therefore held within the mold in a state in which they are unlikely to peel off from the rim base material portion 20. Then, by performing insert molding using the mold with the rim base material portion 20 held inside, the covering portion 30 made of soft synthetic resin is formed on the outside of the rim base material portion 20 and the sensor component 40. As a result, the rim portion 10 shown in Figures 2 and 3 is produced.

[0051] In the steering wheel 1 of this embodiment having the rim portion 10 produced as described above, the covering portion 30 that covers the rim base material portion 20 and the sensor component 40 is formed by insert molding, rather than being formed by manual pasting by an operator as in Patent Document 1, for example. This makes it possible to efficiently form the rim portion 10 equipped with the covering portion 30. It also makes it possible to reduce the variation in quality of the steering wheel 1 (particularly the rim portion 10) caused by differences in operators.

[0052] Furthermore, according to the steering wheel of this embodiment, the first side edge 46 and the second side edge 47 of the sensor component 40 are bonded to the flat portion 27 of the rim base material portion 20, so that the above-mentioned reaction force generated at the first side edge 46 and the second side edge 47 can be suppressed and the first side edge 46 and the second side edge 47 can be held without peeling off from the rim base material portion 20. Therefore, even if the rim base material portion 20 to which the sensor component 40 is attached is set in a mold and the covering portion 30 is molded to form the rim portion 10, it is possible to prevent parts of the first side edge 46 and the second side edge 47 of the sensor component 40 from peeling off from the rim base material portion 20 and being exposed on the outer surface of the covering portion 30, and to prevent unnatural convexities or protrusions from being formed on the outer surface of the covering portion 30.

[0053] Furthermore, in the steering wheel of this embodiment, the second covering portion 32 of the covering portion 30 is formed on the flat portion 27 of the rim base material portion 20 to be thicker than the first covering portion 31 so as to make the cross section of the rim portion 10 circular (or approximately circular). Therefore, even if a part of the first side edge portion 46 and the second side edge portion 47 of the sensor component 40 peels off from the rim base material portion 20 before the soft synthetic resin is filled into the mold in the molding process of the covering portion 30, the peeled part of the first side edge portion 46 and the second side edge portion 47 can be made to be more unlikely to be exposed on the outer surface of the covering portion 30 by the thick second covering portion 32 of the covering portion 30 to be molded. In addition, it is possible to make it difficult to form an unnatural convex portion or protrusion due to the peeled part.

[0054] As a result, it is possible to effectively prevent deterioration in the appearance quality and yield of the steering wheel caused by peeling off of the sensor component 40. Furthermore, since there is no need to take measures or processes to prevent peeling off of the sensor component 40, it is expected that the manufacturing cost can be reduced and the manufacturing process can be simplified.

[0055] In addition, it is generally known that when a driver grips the rim portion 10 of the steering wheel 1, the driver's fingertips are likely to come into contact with the inner circumference 11 of the rim portion 10 and its vicinity, and therefore the inner circumference 11 of the rim portion 10 is less likely to affect the performance and accuracy of detecting that the driver is gripping the rim portion 10 than the outer circumference 12 of the rim portion 10.

[0056] For this reason, in the steering wheel 1 of this embodiment, even if a gap is formed between the first side edge 46 and the second side edge 47 of the sensor component 40 in the inner circumference 11 of the rim portion 10, which is unlikely to affect the grip detection performance and detection accuracy, even if there are portions of the first side edge 46 and the second side edge 47 of the sensor component 40 where the sensor electrode 42 is not arranged, or even if the second covering portion 32 of the covering portion 30 is formed thick, it is possible to prevent a decrease in the performance and accuracy of detecting the driver's grip by the sensor component 40.

[0057] The present invention is not limited to the above-described embodiments, and various modifications are possible as long as they have substantially the same configuration as those described in the claims of the present invention and provide similar operational effects.

[0058] For example, the shape, dimensions, and design of the steering wheel are not particularly limited and can be changed. In the above-mentioned embodiment, the sheet-like functional part arranged between the rim core metal part and the covering part is a sensor part that detects the driver's contact with the rim part. However, in the present invention, the sheet-like functional part is not limited to a sensor part, and may be, for example, a heater part such as a heater sheet having a function of heating the rim part, or a sheet-like part having other functions. [Explanation of symbols]

[0059] 1 Steering wheel 2 Steering body 3 Steering Pad 4 Finisher 10 Rim 11 Inner circumference 12 Outer periphery 20 Rim base material 21 Rim core metal 22 Protective part (inner resin part) 26 Curved part 27 Flat surface (side edge attachment part) 28 Formation area 30 Covering part (outer resin part) 31 First Covering Section 32 Second Covering Section 40 Sensor parts 41 Base 42 Sensor electrode 43 Guard Electrode 46 First side edge (left side edge) 47 Second side edge (right side edge)

Claims

1. A steering wheel having at least an annular rim portion, a cross section perpendicular to the circumferential direction of the rim portion being formed to be circular or approximately circular, the rim portion having a rim base material portion, a covering portion that covers the rim base material portion from the outside, and a sheet-like functional component disposed between the rim base material portion and the covering portion, The functional component has a first side edge portion including one side edge in a width direction of the functional component and a second side edge portion including the other side edge in the width direction of the functional component, When the cross section of the rim portion is viewed, the rim base material portion has a side edge mounting portion on which the first side edge portion and the second side edge portion of the functional component are arranged, and the outer peripheral surface of the side edge mounting portion is formed with a curvature smaller than the curvature of the outer surface formed by the covering portion in correspondence with the formation area of ​​the side edge mounting portion. A steering wheel characterized by:

2. When the cross section of the rim portion is viewed, the rim base material portion has a curved surface portion formed in an arc shape or a substantially arc shape, and a flat surface portion formed in a straight line, When the cross section of the rim portion is viewed, a part of the functional component is disposed on the curved surface portion of the rim base material portion, and the first side edge portion and the second side edge portion of the functional component are disposed on the flat surface portion of the rim base material portion.

2. The steering wheel of claim 1.

3. the covering portion has a first covering portion provided corresponding to at least a part of a portion of the rim portion where the curved surface portion is formed, and a second covering portion provided corresponding to a portion of the rim portion where the flat surface portion is formed and formed thicker than the first covering portion, When the cross section of the rim portion is viewed, the second covering portion has a shape that makes the cross section of the rim portion circular or approximately circular.

3. A steering wheel according to claim 2.

4. The side edge mounting portion of the rim portion is provided on the inner periphery of the annular rim portion.

2. The steering wheel of claim 1.

5. The covering portion is made of an elastic synthetic resin.

2. The steering wheel of claim 1.

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