Steering wheel

Abstract

To provide a steering wheel capable of preventing an adjacent layer, which adjoins a skin layer, from being damaged due to an external force applied during work of finishing a seam of a skin layer material.SOLUTION: A steering wheel having a rim part which includes a core bar and a sheath 5 covering the core bar, includes a mat material 6 that is interposed between a skin material 9 of the rim part and the sheath 5 and has a conductive part 7 on the skin material 9 side. The skin material 9 has a seam 91 formed in a direction intersecting a circumferential direction of the rim part. The sheath 5 is formed with a groove 51, which receives the seam 91 and part of the mat material 6. A skid 8 is interposed between the skin material 9 and conductive part 7 at least in the vicinity of the seam 91.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a steering wheel.

Background Art

[0002] In recent years, steering wheels have become widely popular in which a conductive layer is provided between the skin layer and the core metal so that it is possible to detect whether a driver is gripping or releasing the rim portion.

[0003] For example, Patent Document 1 discloses a steering wheel in which a conductive layer made of an elastic body is provided between the skin layer and the core metal of the rim portion, and based on a change in capacitance between the driver's hand and the elastic body layer while ensuring flexibility, it is possible to detect whether the driver is gripping or releasing the rim portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As vehicles are increasingly equipped with an automatic driving function, the concept of the steering wheel is changing from something that a driver always operates to something that is operated as needed. Accordingly, the shape of the steering wheel itself is also changing from the conventional substantially circular shape to a non-circular shape. Along with this, in the skin layer used to improve the design of steering wheels of various shapes, it is necessary to match parts of various shapes.

[0006] In addition, in some cases, a sheet-like material such as natural leather or artificial leather (hereinafter referred to as the skin layer material) is used as the skin layer of the rim portion. In such a case, the skin layer is formed by sewing together the skin layer materials of a plurality of parts. The joints between the skin layer material parts are arranged at various locations on the rim portion. Further, in order to improve the appearance, a recess is formed in the covering material that covers the core metal, and a finish is performed in which the joint between the parts is pushed into the recess.

[0007] On the other hand, when an operator pushes the joint into the recess, the force applied to the joint by the operator is also transmitted to the adjacent layer adjacent to the skin layer through the joint. Thus, the force applied to the adjacent layer through the joint may damage the adjacent layer, such as causing distortion in the adjacent layer. However, Patent Document 1 only considers the case of using a coating layer as the skin layer of the rim portion, and does not consider the case of using the above-described skin layer material, and thus cannot solve such a problem.

[0008] The present invention has been made in view of such circumstances, and an object thereof is to prevent damage to an adjacent layer adjacent to the skin layer due to an external force applied during the operation of finishing the joint portion (seam portion) of the skin layer material formed at various locations, in order to form a skin layer provided for improving the designability of steering wheels of various shapes.

Means for Solving the Problems

[0009] The steering wheel according to the present invention is a steering wheel including a rim portion having a core metal and a covering portion covering the core metal, and is provided between the skin material of the rim portion and the covering portion, and includes a mat material having a conductive portion on the skin material side. The skin material has a joint formed in a direction intersecting the circumferential direction of the rim portion, and a groove for receiving the joint and a part of the mat material is formed in the covering portion. At least a sliding material is interposed between the skin material and the conductive portion, at least in the vicinity of the joint.

Effects of the Invention

[0010] According to the present invention, it is possible to prevent the adjacent layer adjacent to the skin layer from being damaged by an external force applied during the operation of finishing the joint of the skin layer material. In addition, as the popularity of self-driving vehicles progresses, a steering wheel shape assuming various hands-on / hands-off (steering / non-steering) scenes has emerged, and even if a more disadvantageous structural environment is created for the adjacent layer, the resistance can be enhanced.

Brief Description of the Drawings

[0011]

Figure 1

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, the steering wheel according to the embodiment of the present invention will be described in detail with reference to the drawings.

[0013] FIG. 1 is a front view of a steering wheel 100 according to the present embodiment. The steering wheel 100 for a vehicle according to the present embodiment includes an annular rim portion 10 and a hub portion 11 disposed on the center side of the rim portion 10. The hub portion 11 is connected to the rim portion 10 by three spoke portions 3. Further, an airbag (not shown) is installed inside the hub portion 11.

[0014] The surface of the rim portion 10 is covered with a skin material 9, and the skin material 9 is made of, for example, natural leather, artificial leather, or the like. The skin material 9 includes two parts, a skin material 9a and a skin material 9b. As shown in FIG. 1, the skin materials 9a and 9b are sewn together to form a joint portion 91. The joint portion 91 is formed in a direction intersecting the circumferential direction of the rim portion 10 and is formed at two locations spaced apart in the circumferential direction of the rim portion 10.

[0015] FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1. FIG. 3 shows a cross-section of the rim portion 10 near the joint portion 91 of the skin material 9, and FIG. 2 shows a cross-section of the rim portion 10 at a portion other than the joint portion 91. FIGS. 2 and 3 show cross-sections along a direction orthogonal to the axis of the rim portion 10.

[0016] As shown in FIGS. 2 to 3, the internal configuration of the rim portion 10 of the steering wheel 100 according to the present embodiment differs depending on the circumferential position of the rim portion 10. First, based on FIG. 2, the internal configuration of the rim portion 10 at a portion other than the joint portion 91 will be described.

[0017] The rim portion 10 is circular in cross-section, and a rim core metal 20 is located at the center of the rim portion 10. The rim core metal 20 has a U-shaped cross-section and is made of, for example, a metal or alloy such as magnesium or aluminum. The rim core metal 20 is covered by a covering portion 5.

[0018] The covering portion 5 has insulation properties and is made of, for example, urethane, elastomer, or the like. The covering portion 5 covers the rim core metal 20 and has a substantially circular cross-section.

[0019] The outer side of the covering portion 5 is covered by a mat material 6. That is, one main surface of the mat material 6 is in contact with the covering portion 5. The mat material 6 is made of a flexible elastic material. The mat material 6 is made of, for example, polyurethane, elastomer, etc. Although not shown, a GND wire is provided inside the mat material 6.

[0020] Also, a conductive cloth 7 is laid on the other main surface side of the mat material 6. The conductive cloth 7 is a fabric manufactured by weaving fibers vertically and horizontally. For example, PET (polyethylene terephthalate) fibers are used. A plating treatment using a conductive material such as silver, copper, nickel, etc. is applied to the surface of the conductive cloth 7, whereby the conductive cloth 7 has conductivity.

[0021] Furthermore, the mat material 6 and the conductive cloth 7 are covered by the skin material 9 as described above. That is, the skin material 9 is adjacent to the conductive cloth 7 and is the outermost layer of the rim portion 10 in a cross-sectional view. The skin material 9 is grasped by the driver and is the part that the driver's hand directly touches.

[0022] In this way, the rim portion 10 is in contact with each other without anything intervening between the conductive cloth 7 and the skin material 9 at parts other than the joint portion 91. However, it is different in the vicinity of the joint portion 91. This will be described in detail below with reference to FIGS. 3 and 4.

[0023] FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 1. FIG. 4 shows a cross-section in the vicinity of the joint portion 91. Even in the vicinity of the joint portion 91, similar to the parts other than the joint portion 91, a rim core metal 20 is located on the center side of the rim portion 10, and the rim core metal 20 is covered by an insulating covering portion 5. On the other hand, in the vicinity of the joint portion 91, a groove 51 is provided circumferentially on the outer surface of the covering portion 5 in the circumferential direction of the rim portion 10. The groove 51 has a substantially U-shaped cross-section and is formed obliquely with respect to the radial direction of the rim portion 10.

[0024] In addition, the outer surface of the covering portion 5 is covered with a mat material 6. Similar to the portions other than the joint portion 91, a conductive cloth 7 is laid on the other main surface side of the mat material 6, and the conductive cloth 7 is covered with a skin material 9.

[0025] Furthermore, in the vicinity of the joint portion 91, a sliding material 8 is interposed between the conductive cloth 7 and the skin material 9. The sliding material 8 is disposed over the vicinity of the groove 51 including the groove 51 of the covering portion 5 in the circumferential direction of the rim portion 10. Also, the sliding material 8 is provided circumferentially around the rim portion 10 in a cross-sectional view. The sliding material 8 is made of a material having a coefficient of static friction between the skin material 9 smaller than the coefficient of static friction between the skin material 9 and the conductive cloth 7. For example, the sliding material 8 is made of a non-woven fabric or the like.

[0026] Note that in the vicinity of the joint portion 91, the joint portion 91 of the skin materials 9a and 9b is received in the groove 51 together with a part of the mat material 6, the conductive cloth 7, and the sliding material 8. At this time, the mat material 6 and the conductive cloth 7 extend over the entire inner surface of the groove 51. In FIG. 4, reference numeral “30” is a seam of the skin materials 9a and 9b.

[0027] The steering wheel 100 having the above-described configuration can detect whether the driver is gripping the steering wheel 100 or has released the hand from the steering wheel 100.

[0028] Specifically, due to the gripping force of the driver who grips the rim portion 10, the distance between the conductive cloth 7 and the GND line of the mat material 6 in the radial direction of the rim portion 10 changes, and accordingly, the capacitance changes. By detecting such a change in capacitance, it is detected whether the driver is gripping the steering wheel 100.

[0029] FIG. 5 is an explanatory view of the manufacturing process of the steering wheel 100. FIG. 5 shows a process of sewing and finishing a sheet related to the skin material 9 (hereinafter referred to as a skin material sheet).

[0030] When sewing the skin material sheet, in order to improve the appearance, the sewing is performed so that the seam is arranged on the inner peripheral side of the rim portion 10. Such sewing work of the rim portion 10 is performed by using a dedicated tool 50, while pulling the thread 40 passing through both edges of the aligned skin material sheets to the inner peripheral side of the rim portion 10 (see the arrow in FIG. 5). That is, during the sewing work, a force (hereinafter referred to as the sewing force) that is pulled toward the center side of the rim portion 10 is applied to both edges of the skin material sheet.

[0031] Therefore, in the portion on the inner peripheral side of the rim portion 10 in a cross-sectional view of the skin material sheet, the sewing force acts as a tension, and the skin material sheet extends. In FIG. 5, the tension is indicated by a black arrow, and the length of the arrow indicates the magnitude of the tension. Also, in the portion on the outer peripheral side of the rim portion 10 in a cross-sectional view of the skin material sheet, the sewing force acts as a pressing force on the conductive cloth 7. In FIG. 5, the pressing force applied to the conductive cloth 7 is indicated by a white arrow, and the length of the arrow indicates the magnitude of the pressing force.

[0032] Furthermore, after the completion of the sewing work, since a restoring force acts on the skin material sheet that has extended during the sewing work, the skin material sheet contracts. Therefore, there is a possibility that stress may be generated in the adjacent conductive cloth 7 due to the expansion and contraction of the skin material sheet. That is, due to the friction between the conductive cloth 7 and the skin material 9, the conductive cloth 7 may also expand and contract according to the expansion and contraction of the skin material 9.

[0033] On the other hand, as described above, the conductive cloth 7 is a woven fabric and has conductivity by plating treatment. However, when the conductive cloth 7 expands or contracts along with the expansion and contraction of the skin material 9, a shift in the intersection where the warp or weft constituting the conductive cloth 7 deviates from the normal intersection position where the warp and weft intersect may occur. The intersection shift increases as the sewing force increases, and when the intersection shift occurs, conduction cannot be achieved at such intersections.

[0034] In the conductive cloth 7 that has received the pressing force of the skin material 9, in addition to the above-described intersection shift, there is also a possibility that the warp or weft may be damaged. Furthermore, the pressing force of the skin material 9 is also transmitted to the mat material 6 via the conductive cloth 7. In the mat material 6 that receives the pressing force of the skin material 9, as a result, the GND line protrudes relatively toward the conductive cloth 7 side, which may also increase the damage to the warp or weft.

[0035] On the other hand, during the finishing of the rim portion 10, in order to improve the appearance, an operation of pushing the joint portion 91 of the skin material 9 into the groove 51 is performed. By such an operation, as described above, the joint portion 91 is received in the groove 51 together with a part of the mat material 6, the conductive cloth 7, and the sliding material 8.

[0036] However, during such an operation, since the force for pushing the joint portion 91 into the groove 51 is also transmitted to the conductive cloth 7 via the skin material 9, the conductive cloth 7 is distorted and receives the pressing force. FIG. 6 is a cross-sectional view for explaining the damage received by the conductive cloth 7 by the operation of pushing the joint portion 91 into the groove 51.

[0037] During the operation of pushing the joint portion 91 into the groove 51 (hereinafter referred to as the pushing operation), a large force is applied from the outside of the skin material 9 toward the inside of the groove 51 (see the black arrow in FIG. 6). As a result, while the joint portion 91 is being pushed into the groove 51, the skin material 9 extends in the vicinity of the seam 30. Further, after such a pushing operation, a restoring force acts on the extended skin material 9, and the skin material 9 contracts. Therefore, expansion and contraction of the skin material 9 occur in the vicinity of the seam 30 (see the solid arrow in FIG. 6).

[0038] Therefore, when the skin material 9 expands and contracts, in the region R1 of the conductive cloth 7 corresponding to the vicinity of the seam 30, the conductive cloth 7 may also expand and contract due to the friction between the conductive cloth 7 and the skin material 9. Further, due to this, there may be a risk of the intersection deviation described above occurring in the conductive cloth 7. Furthermore, since the conductive cloth 7 is curved toward the inside of the groove 51 in the region R1, there is also a risk of damage to the conductive cloth 7.

[0039] On the other hand, when pushing in the joint portion 91, the external pressing force is transmitted to the conductive cloth 7 at the bottom of the groove 51 via the joint portion 91. That is, in the conductive cloth 7, in the region R2 facing the direction of the external pressing force, it receives the external pressing force (refer to the arrow in the region R2 of FIG. 6), and there is a risk of damage to the warp or weft.

[0040] Furthermore, the external pressing force is also transmitted to the mat material 6 via the conductive cloth 7. In the mat material 6 that has received the pressing force, as a result, the GND line protrudes relatively toward the conductive cloth 7 side, which may further increase the damage to the warp or weft of the conductive cloth 7.

[0041] That is, in the vicinity of the joint portion 91 of the skin material 9, in addition to the intersection displacement that may occur during the sewing operation of the skin material sheet, the probability of intersection displacement, distortion, and damage that may occur during the pushing-in operation of the joint portion 91 is high.

[0042] In contrast, as described above, in the steering wheel 100 of the present embodiment, in the vicinity of the joint portion 91, a sliding material 8 is interposed between the conductive cloth 7 and the skin material 9, and the static friction coefficient between the sliding material 8 and the skin material 9 is configured to be smaller than the static friction coefficient between the skin material 9 and the conductive cloth 7.

[0043] Therefore, in the vicinity of the joint portion 91, since the conductive cloth 7 is in contact with the skin material 9 via the sliding material 8 and the friction between the skin material 9 and the sliding material 8 is reduced, the expansion and contraction (stress) generated in the skin material 9 are less likely to be transmitted to the conductive cloth 7. Thus, the occurrence of intersection displacement can be prevented.

[0044] Also, in the vicinity of the joint portion 91, since the sliding material 8 is interposed between the skin material 9 and the conductive cloth 7, a part of the pressing force applied from the outside during the pushing-in operation of the joint portion 91 is absorbed and relaxed by the sliding material 8. Therefore, damage to the conductive cloth 7 due to such a pressing force can be suppressed as much as possible.

[0045] Also, as described above, in the steering wheel 100 of the present embodiment, the joint portion 91 of the skin material 9 is received in the groove 51 together with a part of the mat material 6, the conductive cloth 7, and the sliding material 8. Therefore, the joint portion 91 of the skin material 9 cannot be visually recognized from the outside, and the appearance is improved.

[0046] Furthermore, in the steering wheel 100 of the present embodiment, the groove 51 is formed obliquely with respect to the radial direction of the rim portion 10. As a result, compared with the case where the groove 51 is formed along the radial direction of the rim portion 10, it is possible to suppress the detachment of the joint portion 91 received in the groove 51.

[0047] And, in the above, the case where the sliding material 8 is provided only in the vicinity of the joint portion 91 in the rim portion 10 has been described as an example, but the present invention is not limited thereto. A configuration in which the sliding material 8 is provided over the entire range of the rim portion 10 may be employed.

[0048] Also, the present invention is not limited by the dividing direction of the skin material 9 (the direction of the joint portion 91 and the groove 51), and the skin material 9 may be divided in any direction. When the skin material 9 is pulled obliquely with respect to the dividing direction during sewing, local pulling occurs. The sliding material 8 can prevent the pulling force applied to the portion where elongation due to the pulling is not desired from affecting the conductive cloth 7.

[0049] In addition, in the above, the case where the coefficient of static friction between the sliding material 8 and the skin material 9 is smaller than the coefficient of static friction between the skin material 9 and the conductive cloth 7 has been described as an example, but the present invention is not limited thereto. The coefficient of static friction between the sliding material 8 and the skin material 9 may be smaller than the coefficient of static friction between the skin material 9 and the conductive cloth 7, and the coefficient of static friction between the sliding material 8 and the conductive cloth 7 may be smaller than the coefficient of static friction between the skin material 9 and the conductive cloth 7. In this case, in addition to the friction between the skin material 9 and the sliding material 8 being reduced, the friction between the sliding material 8 and the conductive cloth 7 is also reduced, so that the conductive cloth 7 is less likely to be affected by the expansion and contraction generated in the skin material 9.

[0050] In addition, the steering wheel 100 is applicable regardless of the vehicle type, and for example, it is also applicable to vehicles having an automatic driving function.

[0051] In the above, the steering wheel 100 with the rim portion 10 being annular has been described as an example, but the present invention is not limited thereto. Needless to say, it is also applicable to a non-circular steering wheel in which the rim portion 10 is non-circular.

[0052] Figs. 7 to 11 are schematic diagrams illustrating other embodiments of the present invention. Each of the steering wheels 100 according to Figs. 7 to 11 includes a non-circular rim portion 10. For convenience, in Figs. 7 to 11, the joint portion 91 is shown by a solid line.

[0053] As shown in these figures, it is a fact that as the popularization of the automatic driving function progresses, the shape of the steering wheel becomes complicated and the positions of the joint portions are diverse, and the adjacent layer of the skin layer is on the way to a structure that is easily damaged, suggesting that the present invention can prevent this point.

Explanation of Reference Numerals

[0054] 5 Covering portion 6 Mat material 8 Sliding material 7 Conductive cloth (conductive portion) 9 Skin material 10 Rim portion 20 Rim core 30 Seam 51 Groove 91 Joint portion 100 Steering wheel

Claims

1. In a steering wheel (100) comprising a rim portion (10) having a core metal (20) and a covering portion (5) covering the core metal (20), a mat material (6) is provided between the skin material (9) of the rim portion (10) and the covering portion (5), and the mat material (6) has a conductive portion (7) on the side of the skin material (9). The skin material (9) has a joint portion (91) formed in a direction intersecting the circumferential direction of the rim portion (10). A groove (51) for receiving the joint portion (91) and a part of the mat material (6) is formed in the covering portion (5). A sliding material (8) made of non-woven fabric is interposed between the skin material (9) and the conductive portion (7). The sliding material (8) is provided over the entire inner surface of the groove (51) and around the groove (51). The rim portion (10) has a circular cross-section. The groove (51) is formed obliquely by shifting in the circumferential direction of the rim portion (10) with respect to the radial direction of the rim portion (10) as it approaches the core metal (20). The steering wheel (100) is characterized by this.

2. The steering wheel (100) according to claim 1, wherein the coefficient of static friction between the sliding material (8) and the skin material (9) is smaller than the coefficient of static friction between the skin material (9) and the conductive portion (7).

3. The steering wheel (100) according to claim 1 or 2, wherein the conductive portion (7) is provided over the entire inner surface of the groove (51).

4. The steering wheel (100) according to any one of claims 1 to 3, wherein the conductive portion (7) is a fabric having a metallic surface.

5. The steering wheel (100) according to any one of claims 1 to 4, wherein the sliding material (8) is non-woven fabric.

6. The steering wheel (100) according to any one of claims 1 to 5, which is used in a vehicle having an automatic driving function.

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