JP7392685B2 - steering wheel - Google Patents

Description

TECHNICAL FIELD The present invention relates to a steering wheel configured by providing an annular grip that a driver grips during steering with a heater element that can heat up the grip.

Conventionally, this type of steering wheel includes an annular gripping part that can be rotated around a steering center axis, and the gripping part has a steering wheel between a coating layer that covers the core material and a skin layer on the outer surface side. It was configured by disposing a heater element made of a band-shaped sheet body along the circumferential direction around the central axis (see, for example, Patent Document 1). The heater element is formed by adhering a flexible sheet-like back side base material on the coating layer side and a front side base material on the skin layer side to each other with heater wires in between. The structure was such that it was attached and disposed on the outer peripheral surface side of the layer.

Unexamined Japanese Patent Publication No. 2016-6750

However, in conventional steering wheels, if the band-shaped sheet that constitutes the heater element is difficult to stretch, it is difficult to stick to the surface side of the coating layer, and wrinkles appear on the inner circumferential side of the grip, which is the steering center axis side. This causes a situation where the feel of the epidermis layer becomes worse.

The present invention solves the above-mentioned problems, and aims to provide a steering wheel that can suppress deterioration in feel even if a skin layer is provided around a heater element.

The steering wheel according to the present invention includes an annular grip that can be rotated around the steering center axis,
The gripping portion is configured by disposing a heater element made of a band-shaped sheet body along a circumferential direction around the steering center axis between a coating layer that covers the core material and a skin layer on the outer surface side. ,
The heater element is formed by bonding a back side base material on the covering layer side and a front side base material on the skin layer side, which are in the form of a flexible sheet, to each other with a heater wire in between. Also, a steering wheel configured to be attached and disposed on the outer peripheral surface side of the coating layer,
The sheet body of the heater element is characterized in that both edges in the transverse direction are formed as a single layer of one of the back side base material and the front side base material.

In the steering wheel according to the present invention, when the belt-shaped sheet body of the heater element is stretched in the lateral direction so as to be attached to the outer peripheral surface side of the coating layer, both edges in the lateral direction are attached to the back side of the coating layer side. It does not have two layers: the base material and the front base material on the skin layer side, but is composed of a single layer on one side, and has a two-layer structure with the back base material and the front base material bonded to each other. Therefore, it can be easily stretched in the transverse direction, and the heater element can be attached to the outer circumferential surface of the coating layer without causing wrinkles on the inner circumferential side, which is the steering center axis side of the gripping part. be able to. Therefore, even if the epidermis layer is subsequently disposed, the epidermis layer will be disposed smoothly without wrinkles.

Therefore, in the steering wheel according to the present invention, even if a skin layer is provided around the heater element, the heater element is unlikely to wrinkle, so it can be arranged without wrinkles, and deterioration in feel can be suppressed.

In the steering wheel according to the present invention, it is desirable that both edges of the sheet body of the heater element in the lateral direction are each formed as a single layer of the front side base material.

In such a configuration, since the front base material on the side closer to the skin layer constitutes the entire area in the transverse direction, the outer surface side of the heater element attached to the coating layer is made flush with suppressed steps. When the epidermis layer is subsequently disposed, the epidermis layer can be disposed without wrinkles.

FIG. 1 is a schematic plan view showing a steering wheel provided with a heater element according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the grip portion of the steering wheel in which the heater element of the embodiment is disposed, and corresponds to the section II-II in FIG. 1. FIG. It is a top view of the heater element of embodiment. 4 is a cross-sectional view of the heater element of the embodiment, corresponding to the section IV-IV in FIG. 3. FIG. It is a figure explaining the back side base material and front side base material before sandwiching the heater wire in the heater element of an embodiment. It is a figure explaining the state which sticks the heater element of embodiment to a coating layer. It is a figure explaining the state which sticks the heater element of the modification of embodiment to the coating layer. FIG. 7 is a plan view of a heater element according to another modification of the embodiment. 9 is a cross-sectional view of the heater element shown in FIG. 8, corresponding to a section IX-IX in FIG. 8. FIG. FIG. 9 is a diagram illustrating a state in which the heater element shown in FIG. 8 is attached to the outer peripheral surface side of the coating layer.

Hereinafter, one embodiment of the present invention will be described based on the drawings.As shown in FIG. R, a boss part B on the steering center axis CO side located approximately at the center of the grip part R, and spoke parts S (L, R, B) that connect the grip part R and the boss part B. has been done. The spoke portion S includes spoke portions SL and SR extending from the boss portion B to both left and right sides, and a spoke portion SB extending from the boss portion B to the rear side. The steering wheel W also includes an airbag device 45 shown by a two-dot chain line disposed on the upper side of the boss part B, the steering wheel body 1, and a lower cover (not shown) that covers the lower side of the boss part B. Configured with the necessary features.

Further, the steering wheel main body 1 includes a grip portion R, a boss portion B, and a core member 3 made of a metal material such as an aluminum alloy that connects the spoke portions S. The core material 3 connects the grip core material part 4 disposed on the grip part R, the boss core material part 5 disposed on the boss part B, and the grip core material part 4 and the boss core material part 5. The spoke core portions 6 (L, R) and 7 are arranged in the spoke portion S (L, R, B). The boss core portion 5 is provided with a steel boss 5a that is coupled to a steering shaft (not shown) of the vehicle that forms a steering center axis CO. In addition, the spoke core parts 6 are arranged in spoke core parts 6L and 6R arranged in the left and right spoke parts SL and SR, and in the spoke part SB on the rear side, and are arranged on the left and right sides of the boss core part 5. It is composed of two spoke core parts 7, 7 which are branched into two spoke core parts 7, 7, and are connected on the grip core part 4 side.

As shown in FIG. 2, a covering layer 10 made of foamed polyurethane is provided around the gripping core portion 4 disposed on the gripping portion R, and a covering layer 10 made of foamed polyurethane is provided on the surface side of the gripping portion R. Further, between the covering layer 10 and the skin layer 40, a heater element 14 capable of raising the temperature of the grip portion R is provided.

As shown in FIGS. 3 and 4, the heater element 14 is formed by holding a heater wire 35 on a flexible sheet-like base material 19, and extends around the steering center axis CO in the grip portion R. It is made up of a belt-shaped sheet body 16 along the circumferential direction of. In the case of the embodiment, the heater elements 14 are disposed on each of the left and right sides of the grip portion R, and two heater elements 14 are used for the entire steering wheel W. In the case of the embodiment, since the heater element 14R on the right side and the heater element 14L on the left side shown in FIG. 1 differ only in that they are bilaterally symmetrical, the heater element 14R on the right side shown in FIG. The element 14(R) will be explained, and the explanation of the heater element 14(L) on the left side will be omitted.

The base material 19 of the sheet body 16 forming the heater element 14 is composed of two layers: a back side base material 20 on the coating layer 10 side and a front side base material 23 on the skin layer 40 side. and the front base material 23 are bonded to each other with the heater wire 35 in between, thereby holding the heater wire 35 in a sandwiched manner (see FIG. 4).

Further, in the sheet body 16 of the embodiment, both edges (side edges) 16c and 16d in the transverse direction WD are formed as a single layer of one of the back side base material 20 and the front side base material 23. In the case of the embodiment, the side edges 16c and 16d are formed from a single layer portion 25 that is a single layer of the front base material 23. In the case of the embodiment, the width dimension WL0 of the sheet body 16 (heater element 14) is set to 100 mm within the range of approximately 90 to 110 mm, and the width dimension WL1 of the single layer portion 25 is set to 12 mm within the range of approximately 5 to 25 mm. There is. In other words, the width WL1 of the single layer portion 25 is approximately 4 to 27% of the width WL0 of the sheet body 16 (heater element 14).

Furthermore, both the back side base material 20 and the front side base material 23 are formed from sheet materials of foamed polyurethane, and the thickness dimensions tA1 and tB1 of the back side base material 20 and the front side base material 23 are both 0.5 to 0.5. It is set to 0.7 mm within the range of 0.8 mm. However, regarding the density of the back side base material 20 and the front side base material 23, the density on the front side base material 23 side is made higher than the density of the back side base material 20. Specifically, the density of the back side base material 20 is set to 0.2 g/cm ³ within a range of about 0.1 to 0.3 g/cm ³ . The density of the front side base material 23 is set to 0.5 g/cm ³ within a range of about 0.3 to 0.7 g/cm ³ . Incidentally, in the embodiment, the front base material 23 on the side closer to the skin layer 40 of the heater element 14 has a high density and can have good thermal conductivity, so that the heat generated by the heater wire 35 is transferred to the skin layer 40. On the contrary, the back side base material 20 lowers its density and improves its heat insulation properties, suppressing heat conduction to the core material 3 (grip core material part 4) side. The temperature can be efficiently raised on the skin layer 40 side during energization.

In addition, in the case of the embodiment, as shown in FIG. 5, the back side base material 20 is a sheet-like preliminary back side member 21 whose thickness dimension tA0 was 3.5 mm, which is about 3 to 4 mm, and has a thickness of about 1/5. The front base material 23 is a sheet-like preliminary front member 24 whose thickness dimension tB0 is 8 mm, which is about 5 to 10 mm, and is compressed to a thickness of about 1/12 of the thickness tA1 of 0.7 mm. It is compressed and formed to have a dimension tB1 of 0.7 mm.

The heater element 14 is constructed by using an adhesive 31 between the back side base material 20 and the front side base material 23, which have the same thickness dimensions tA1 and tB1, with the heater wire 35 in a predetermined wiring pattern in between. They are formed by adhering them to each other.

In the case of the embodiment, the heater wire 35 includes a conductor wire made of a tin-copper alloy wire with a wire diameter of about 0.08 mm on the outer periphery of a heater core made of an aromatic polyamide fiber bundle with an outer diameter of about 0.2 mm. It is constructed by winding a plurality of (about 7 pieces) in a spiral shape with a pitch of about 1.00 mm. The heater wire 35 of the embodiment has a wire diameter of about 0.37 mm. As shown in FIG. 3, the heater wires 35 are held between the back side base material 20 and the front side base material 23 of the base material 19 in a predetermined single-stroke pattern, and are connected to a temperature control device (not shown). The lead wire 36 is connected to the lead wire 36.

In addition, in the manufactured heater element 14, the side edges 16c and 16d in the width direction (short direction) WD are arranged on the inner circumferential surface side of the grip portion R when being wrapped around the coating layer 10, so that wrinkles are likely to occur. Therefore, triangular notches 17 are provided in advance on the side edges 16c and 16d (see FIG. 3).

In manufacturing the steering wheel W of the embodiment, a coating layer 10 is provided around the gripping core part 4 of the core bar 2 in the steering wheel body 1 and the spoke core parts 6 and 7 near the gripping core part 4. After that, the heater element 14 is attached to the outer peripheral surface 10a side of the coating layer 10. At that time, while pulling the end edges 16a and 16b of the left and right heater elements 14 so as to touch each other, and pulling the side edges 16c and 16d of the heater element 14 as shown in FIG. It is attached to the outer peripheral surface 10a side. At that time, since the side edges 16c and 16d do not have a two-layer structure in which the back side base material 20 and the front side base material 23 are bonded together, but are made of a single layer part 25 of only the front side base material 23, they are easy to stretch, and the grip part It can be attached to the inner surface 10c side of the outer peripheral surface 10a of the coating layer 10 on the inner peripheral surface side of R without causing wrinkles. Of course, notches 17 are also provided on the side edges 16c and 16d, and when the side edges 16c and 16d are attached to the outer peripheral surface 10a, the notches 17 are narrowed to further prevent wrinkles. It can be attached to the outer circumferential surface 10a of the coating layer 10 on the inner circumferential surface side of the gripping part R without causing any damage. In addition, on the outer surface 10b side of the outer circumferential surface 10a of the coating layer 10, the end edges 16a and 16b of the left and right heater elements 14 are pulled and attached so as to abut each other.

After pasting the heater element 14, the steering wheel body 1 can be manufactured by wrapping the leather 41 as the skin layer 40 around the outer peripheral surface of the heater element 14 using the adhesive 38. After that, while attaching a lower cover (not shown) to the lower side of the boss part B, the boss 5a of the boss part B is fastened to the steering shaft of the vehicle, and the airbag device 45 is attached to the upper side of the boss part B. The wheel W can be assembled and the steering wheel W can be mounted on the vehicle. Note that when installing the airbag device 45, the lead wire 36 of the heater element 14 is connected to a lead wire extending from a detection circuit (not shown) capable of detecting the driver's grip.

In the steering wheel W mounted on the vehicle, the heater wire 35 of the heater element 14 is energized under the control of a temperature control device (not shown), and the temperature of the grip portion R is raised to a predetermined temperature.

In the steering wheel W of the embodiment, when stretching the strip-shaped sheet body 16 of the heater element 14 in the transverse direction WD so as to adhere it to the outer circumferential surface 10a side of the coating layer 10, The edges 16c and 16d do not have two layers, the back side base material 20 on the coating layer 10 side and the front side base material 23 on the skin layer 40 side, and are composed of a single layer part 25 on one side, Since it does not have a two-layer structure of the back side base material 20 and the front side base material 23 that are bonded to each other, it can be easily stretched in the lateral direction WD, and the inner periphery on the side of the steering center axis CO in the grip portion R can be easily stretched. The heater element 14 can be attached to the outer circumferential surface 10a side of the coating layer 10 without causing wrinkles on the side (inner surface 10c side). Therefore, even if the skin layer 40 is subsequently disposed, the skin layer 40 is smoothly disposed without wrinkles.

Therefore, in the steering wheel W of the embodiment, even if the skin layer 40 is provided around the heater element 14, wrinkles do not easily occur in the heater element 14, so that the steering wheel W can be arranged without wrinkles, and deterioration in feel can be suppressed.

In the steering wheel W of the embodiment, both edges 16c and 16d of the sheet body 16 of the heater element 14 in the lateral direction WD are each formed as a single layer portion 25 of the front side base material 23.

Therefore, in the embodiment, since the front side base material 23 on the side closer to the skin layer 40 constitutes the entire area in the transverse direction WD, the outer surface side of the heater element 14 attached to the coating layer 10 can be Since the surface layer 40 can be made flush, the skin layer 40 can be provided even more without wrinkles when the skin layer 40 is subsequently provided.

Of course, like the sheet body 16A of the heater element 14A shown in FIG. 7, both edges 16c and 16d in the transverse direction WD may be configured from the single layer portion 25A on the back side base material 20A side. That is, in the back side base material 20A and the front side base material 23A, which serve as the base material 19A that holds the heater wire 35 in a sandwiched manner, both edges 16c and 16d in the widthwise direction WD are composed of only the back side base material 20A. . Note that these back side base material 20A and front side base material 23A are formed from the same foamed polyurethane as the back side base material 20 and front side base material 23 of the embodiment.

In this case, when the sheet body 16A is stretched in the transverse direction WD so as to be attached to the outer circumferential surface 10a of the coating layer 10, both edges 16c and 16d in the transverse direction WD are attached to the back side of the coating layer 10. The two layers of the material 20A and the front base material 23A on the skin layer 40 side are not disposed, but are composed of a single layer part 25A on one side, and the back base material 20A and the front base material are bonded to each other. Since it does not have a two-layer structure with 23A, it can be easily stretched in the lateral direction WD without causing wrinkles on the inner peripheral side (inner surface 10c side) of the grip portion R that is on the steering center axis CO side. In addition, the heater element 14A can be attached to the outer peripheral surface 10a side of the coating layer 10. Therefore, even if the skin layer 40 is subsequently disposed, the skin layer 40 is smoothly disposed without wrinkles.

In addition, in the case of configuring the heater element so that it can easily extend in the longitudinal direction LD, for example, as shown in FIGS. A heater element 14B may be used in which a large number of slits 26 are formed so as to be arranged in parallel in the direction LD. The slit 26 is formed on the front side of the front base material 23B, which is the skin layer 40 side.

In this heater element 14B, in the back side base material 20B and the front side base material 23B as the base material 19B which holds the heater wire 35 in a sandwich manner, both edges 16c and 16d in the width direction WD are formed only by the front side base material 23B. It is configured. Note that these back side base material 20B and front side base material 23B are formed from the same foamed polyurethane as the back side base material 20 and front side base material 23 of the embodiment.

In this heater element 14B, when it is attached to the outer surface 10a of the coating layer 10, both edges 16c and 16d of the sheet body 16B in the width direction WD are composed of a single layer portion 25B, and the inner surface 10c side (see FIG. 6) without wrinkles. Furthermore, when the belt-shaped sheet body 16B of the heater element 14B is stretched in the longitudinal direction LD so as to be attached to the outer circumferential surface 10a side of the coating layer 10, the outer circumferential surface 10b side of the outer circumferential surface 10a is as shown in FIG. Thus, each slit 26 opens so as to widen the opposing walls 26b and 26b in the slit 26, and easily extends in the longitudinal direction LD, without causing wrinkles, on the outer circumferential surface 10a side of the coating layer 10. It can be attached to. Therefore, even if the skin layer 40 is subsequently disposed, the skin layer 40 will be smoothly disposed without wrinkles.

Incidentally, the slit 26 as described above is a heater element 14B having a two-layer structure in which a back side base material 20B and a front side base material 23B made of polyurethane foam are bonded to each other, and elongation in the longitudinal direction LD is suppressed. It is suitable if

In addition, when providing a slit in the front side base material 23B, the slit may be provided not only in the slit 26 on the front side but also on the back side.

3... Core material, 4... Gripping core material portion, 10... Coating layer, 10a... Outer peripheral surface, 14, 14A, 14B... Heater element, 16, 16A, 16B... Sheet body, 16a... Side edge,
16b... Side edge, 20, 20A, 20B... Back side base material, 23, 23A, 23B... Front side base material, 25, 25A, 25B... Single layer part, 35... Heater wire, 40... Skin layer,
WD...Short direction (of the seat body), LD...Longitudinal direction (of the seat body), R...Gripping portion, CO...Steering center axis, W...Steering wheel.

Claims (2)

Equipped with an annular grip that can be rotated around the steering center axis,
The gripping portion is configured by disposing a heater element made of a band-shaped sheet body along a circumferential direction around the steering center axis between a coating layer that covers the core material and a skin layer on the outer surface side. ,
The heater element is formed by bonding a back side base material on the covering layer side and a front side base material on the skin layer side, which are in the form of a flexible sheet, to each other with a heater wire in between. Also, a steering wheel configured to be attached and disposed on the outer peripheral surface side of the coating layer,
A steering wheel characterized in that the sheet body of the heater element is formed such that both edges in the transverse direction are formed as a single layer of one of the back side base material and the front side base material. The steering wheel according to claim 1, wherein both edges of the sheet body of the heater element in the lateral direction are each formed as a single layer of the front side base material.

Images