Steering wheel

Abstract

To provide a steering wheel configured to be able to reduce burdens on wrists of a driver when the driver grips a steering part and suppress the steering part from deteriorating in operability, with a simple structure, even when the wheel is mounted on a vehicle in which an angle of a steering shaft with respect to a horizontal surface is small.SOLUTION: A steering wheel 10 comprises a boss part 3 connected to a steering shaft 55 of a vehicle 50, and a steering part 1 that is gripped by a driver M and is rotationally steered with the steering shaft 55 as a center. The steering part 1 has general portions 1ax1 and 1bx1 forming a steering surface P inclined to fall forward, with respect to a flat surface S that is orthogonal to a rotation axis R of the steering shaft 55 and bending portions 1ax2 and 1bx bending forward from lower end portions 1ax1 and 1bx1b of the general portions 1ax1 and 1bx1.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a steering wheel mounted on a vehicle. [Background technology]

[0002] A steering wheel mounted on a vehicle includes a boss portion connected to a steering shaft serving as the steering axis of the vehicle, and a steering portion that is gripped by the driver and rotated around the steering shaft. The steering surface of the steering portion is generally positioned perpendicular to the steering shaft.

[0003] Furthermore, the space below the steering wheel, i.e., the space under the driver's feet, can be designed to be larger as the angle of the steering shaft relative to the horizontal plane becomes smaller. In a configuration in which the steering surface of the steering unit is positioned perpendicular to the rotation axis of the steering shaft, if the angle of the steering shaft relative to the horizontal plane is small, the steering surface of the steering unit will be positioned at an angle close to perpendicular to the horizontal plane. In this case, the driver's wrists will be more likely to be strained when gripping the steering unit.

[0004] On the other hand, Patent Document 1 describes a steering wheel in which the steering surface is tilted forward with respect to a plane perpendicular to the rotation axis of the steering shaft. This configuration reduces the angle of the steering surface with respect to the horizontal plane, reducing the strain on the driver's wrists when gripping the steering part.

[0005] Furthermore, when the above configuration is adopted, the lower part of the steering unit approaches the abdomen of the driver, which may cause interference between the driver's elbow joint and abdomen when the driver turns the steering unit, resulting in a risk of reduced operability of the steering unit.In response to this, Patent Document 1 describes a configuration in which a mechanism is provided that changes the steering surface so that it approaches perpendicular to the horizontal plane as the rotation angle of the steering unit increases, thereby moving the lower part of the steering unit away from the abdomen of the driver and preventing a reduction in operability of the steering unit. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-111245 Summary of the Invention [Problem to be solved by the invention]

[0007] In the configuration described in Patent Document 1, a mechanism including an actuator, a motor, gears, etc. is provided as a mechanism for changing the steering surface so that it approaches perpendicular to the horizontal plane as the rotation angle of the steering section increases. When such a mechanism is provided, the configuration of the steering wheel becomes complicated, which may lead to an increase in the number of parts and a deterioration in assembly ease.

[0008] Therefore, the present invention aims to provide a steering wheel that has a simple configuration, reduces the strain on the driver's wrist when gripping the steering section, and prevents a decrease in the operability of the steering section, even when installed in a vehicle with a small angle of the steering shaft relative to the horizontal plane. [Means for solving the problem]

[0009] A typical configuration of a steering wheel according to the present invention for solving the above-mentioned problems is characterized by comprising: a boss portion connected to a steering shaft of a vehicle; and a steering section that is gripped by a driver and rotated and steered around the steering shaft, the steering section having a first region that forms a steering surface that is inclined so as to lean forward with respect to a plane perpendicular to the rotation axis of the steering shaft; and a second region that bends forward from the lower end of the first region.

[0010] According to the present invention, even when a steering wheel is installed in a vehicle in which the angle of the steering shaft relative to the horizontal plane is small, the simple configuration can reduce the strain on the driver's wrist when gripping the steering section and prevent a decrease in the operability of the steering section. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a view of the area around the driver's seat of a vehicle equipped with a steering wheel according to an embodiment of the present invention, viewed from the left side. [Figure 2] 1A and 1B are a front view and a cross-sectional view of a steering wheel; [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 1 is a view of the area around the driver's seat of a vehicle equipped with a steering wheel, viewed from the left side. DETAILED DESCRIPTION OF THE INVENTION

[0012] A steering wheel 10 according to one embodiment of the present invention will be described below. Note that the dimensions, materials, shapes, and relative positions of the components described below are not intended to limit the scope of the present invention unless otherwise specified.

[0013] FIG. 1 is a view from the left side of the area around a driver's seat 59 of a vehicle 50 equipped with a steering wheel 10 according to this embodiment. FIG. 2 is a front view and a cross-sectional view of the steering wheel 10. FIG. 3 is a rear view of the steering wheel 10. FIG. 4 is a plan view of the steering wheel 10. FIG. 5 is a left side view of the steering wheel 10. FIG. 6 is a perspective view of the steering wheel 10.

[0014] In the following description, the directions described with respect to the steering wheel 10 refer to the directions when the steering wheel 10 is mounted on the vehicle 50 shown in Fig. 1. In other words, the left-right direction refers to the left and right directions of the vehicle 50 on which the steering wheel 10 is mounted, specifically the left and right directions as seen from the driver M. The front-rear direction refers to the front and rear directions of the vehicle 50, specifically the front and rear directions as seen from the driver M. The up-down direction refers to the up and down directions in the vertical direction.

[0015] 1, the steering wheel 10 is mounted on a vehicle 50 by being connected to a steering shaft 55 serving as a steering axis. The vehicle 50 is equipped with a steering column 56 that is made up of a column tube 56a that partially covers the outer periphery of the steering shaft 55 to support the steering shaft 55, and a column cover 56b that covers the portion of the steering shaft 55 that protrudes rearward from an instrument panel 57. The steering wheel 10 is attached to the tip of the steering shaft 55 that protrudes rearward from the instrument panel 57.

[0016] As shown in Figures 2 to 6, the steering wheel 10 has a boss portion 3 connected to a steering shaft 55, and a steering portion 1 arranged around the boss portion 3 and gripped by the driver M to rotate and steer. The boss portion 3 is a steel member arranged on the front side of the steering wheel 10 and approximately in the center of the steering wheel 10, and has a shaft hole 3a into which the steering shaft 55 is inserted and fitted. With the tip of the steering shaft 55 inserted into and fitted into the shaft hole 3a of the boss portion 3, the tip of the steering shaft 55 is fastened with a nut, thereby connecting the boss portion 3 and the steering shaft 55.

[0017] The boss portion 3 is supported by a support metal plate (not shown). The boss portion 3 can be supported by the support metal plate (not shown) by, for example, integrally molding the two by die-casting, or by fastening to the support metal plate with screws or the like. This support metal plate is disposed in the space between a lower cover 5 that covers the front and side sides of the steering wheel 10, and a pad 4 that covers the rear side of the steering wheel 10. In addition to the support metal plate (not shown), an airbag (not shown), a horn switch (not shown), and the like are provided in the space between the pad 4 and the lower cover 5.

[0018] The steering unit 1 is located on both the left and right sides of the boss portion 3 and is a member to be gripped by the driver M. The steering unit 1 is composed of a left steering unit 1a extending substantially vertically on the left side of the boss portion 3, and a right steering unit 1b extending substantially vertically on the right side of the boss portion 3. The left steering unit 1a has a core 1w, a base material 1v that covers the outer periphery of the core 1w, and a cover member 1z (grip portion) that covers the outer periphery of the base material 1v from the left side of the front of the left steering unit 1a to the left side of the rear of the left steering unit 1a. The right steering unit 1b has a shape symmetrical to the left steering unit 1a with respect to the boss portion 3, and is identical in configuration except for the shape. Therefore, the right steering unit 1b has a core 1w, base material 1v, and cover member 1z (grip portion) that are symmetrical to the left steering unit 1a. In this embodiment, the core 1w is made of aluminum alloy, the base material 1v is made of acrylic resin, and the cover member 1z is made of urethane resin, but they may be made of other materials. The cover member 1z is provided to improve the tactile feel and grip when the driver M grasps the steering unit 1. It is a member configured with a surface friction coefficient higher than that of the base material 1v and is adhered and fixed to the outer periphery of the base material 1v with an adhesive. This cover member 1z is configured so that the outer end face in the left-right direction of the steering unit 1 has a better tactile feel and higher grip than the inner end face (on the boss portion 3 side). Note that the vertical width K1 (FIG. 2) of the part where the cover member 1z is provided in the left steering unit 1a and the right steering unit 1b is set to 120 mm in this embodiment to ensure a width equal to or greater than the average width of the driver M's hand. It is preferable to set the width K1 in the range of 110 mm≦K1≦130 mm.

[0019] The left steering unit 1a has a general portion 1ax1 (first region) extending rearward from the top to the bottom so as to approach the driver M, and a bent portion 1ax2 (second region) bending forward from a lower end portion 1ax1b of the general portion 1ax1. Similarly, the right steering unit 1b has a general portion 1bx1 (first region) extending rearward from the top to the bottom so as to approach the driver M, and a bent portion 1bx2 (second region) bending forward from a lower end portion 1bx1b of the general portion 1bx1. The general portions 1ax1 and 1bx1 are arranged vertically from above to below the center of the boss portion 3. The bent portions 1ax2 and 1bx2 are arranged vertically throughout their entire regions below the center of the boss portion 3. The dashed dotted line shown in FIG. 5 indicates the center line of the boss portion 3. These general portions 1ax1, 1bx1 and bent portions 1ax2, 1bx2 can be easily formed by changing the shape of the core metal 1w.

[0020] In addition, the angle θ5 (FIG. 2) formed by an imaginary line connecting the right end of the upper end 1a1 of the left steering unit 1a and the left end of the lower end 1a2 and the vertical direction is set to 15 degrees in this embodiment. Because the right steering unit 1b has a shape symmetrical to the left steering unit 1a, the angle formed by an imaginary line connecting the left end of the upper end 1b1 of the right steering unit 1b and the right end of the lower end 1b2 and the vertical direction is also set to 15 degrees. By setting the angle θ5 to 15 degrees in this way, the driver M can be guided to a natural driving posture.

[0021] The steering wheel 10 also has an upper connecting portion 7 that connects the upper end portion 1a1 of the left steering portion 1a and the upper end portion 1b1 of the right steering portion 1b. The upper connecting portion 7 is connected to the left steering portion 1a and the right steering portion 1b with screws 93, respectively. The center portion of the upper connecting portion 7 in the left-right direction is connected to a support metal plate (not shown) that supports the boss portion 3 with screws (not shown). The steering wheel 10 also has a left connecting portion 8 that connects the lower end portion 1a2 of the left steering portion 1a to the support metal plate that supports the boss portion 3, and a right connecting portion 9 that connects the lower end portion 1b2 of the right steering portion 1b to the support metal plate that supports the boss portion 3. The left steering portion 1a and the left connecting portion 8 are connected with screws (not shown). The right steering portion 1b and the right connecting portion 9 are connected with screws (not shown). The left connecting portion 8 and the right connecting portion 9 are connected to a support metal plate (not shown) that supports the boss portion 3 with screws (not shown). In this way, the steering section 1 is connected to the boss section 3 via the upper connecting section 7, the left connecting section 8, the right connecting section 9, and the supporting metal plate that supports the boss section 3.

[0022] In addition, the distance K2 (FIG. 4) between the left end face of the left steering unit 1a and the right end face of the right steering unit 1b is set to 370 mm in this embodiment. To achieve this, the angle θ1a (FIG. 4) formed between the extension direction of the connecting portion 7a of the upper connecting portion 7 with the left steering unit 1a and the left-right direction, and the angle θ1b (FIG. 4) formed between the extension direction of the connecting portion 7b of the upper connecting portion 7 with the right steering unit 1b and the left-right direction are each set to 30.4 degrees in this embodiment. In a conventional steering wheel with a circular steering unit, the diameter based on the outer end face of the steering unit is approximately 370 mm. Therefore, by setting the distance K2 to 370 mm as in this embodiment, it is possible to achieve steering performance equivalent to that of a circular steering unit 1.

[0023] The driver M holds the left steering section 1a of the steering unit 1 with his left hand and the right steering section 1b with his right hand, and turns the steering unit 1 around the steering shaft 55 to turn the vehicle 50 right or left and change the direction of travel of the vehicle 50. The steering wheel 10 of this embodiment is equipped with a sensor (not shown) that detects the rotation angle of the steering unit 1, and employs a steer-by-wire system in which the vehicle 50 steers the tires in accordance with the detection result of the sensor.

[0024] Next, the positional relationship of each member constituting the steering wheel 10 will be described in detail. Fig. 7 is a view of the driver's seat 59 of a vehicle 50 equipped with the steering wheel 10, viewed from the left side. Note that Fig. 7 corresponds to Fig. 1, with the horizontal plane H, the rotation axis R of the steering shaft 55, the steering surface P, and the like inserted therein.

[0025] As shown in Fig. 7, the angle θ2 of the steering shaft 55 of the vehicle 50 relative to the horizontal plane H is set to 12 degrees in this embodiment. This angle θ2 is generally set to about 20 degrees. However, since the smaller the angle θ2, the more space can be designed for the feet of the driver M, in this embodiment, the angle θ2 is set to be smaller than usual. This angle θ2 is preferably set in the range of 0 degrees≦θ2<20 degrees.

[0026] Furthermore, when the angle θ2 is set to a small value and the steering surface P of the steering unit 1 is arranged parallel to the plane S perpendicular to the rotation axis R of the steering shaft 55, the steering surface P will be positioned at an angle close to perpendicular to the horizontal plane H. The steering surface P of the steering unit 1 here is an imaginary plane that is tangent to the rear end surface 1ax1a of the general section 1ax1 of the left steering unit 1a and the rear end surface 1bx1a of the general section 1bx1 of the right steering unit 1b. The rotation axis R of the steering shaft 55 is an imaginary line connecting the rotation centers of the steering shaft 55 and is an imaginary line that extends infinitely. In this case, the driver M is more likely to put strain on his or her wrists when gripping the steering unit 1.

[0027] Therefore, in this embodiment, the steering surface P is inclined so as to lean forward with respect to a plane S perpendicular to the rotation axis R of the steering shaft 55. In other words, in the steering unit 1, the general portion 1ax1 of the left steering unit 1a and the general portion 1bx1 of the right steering unit 1b are configured to form a steering surface P that is inclined so as to lean forward with respect to a plane S perpendicular to the rotation axis R of the steering shaft 55. With this configuration, even when the angle θ2 is small, the angle of the steering surface P with respect to the horizontal plane H can be made closer to horizontal, thereby ensuring ample space for the feet of the driver M and reducing the strain on the wrists of the driver M when gripping the steering unit 1.

[0028] Furthermore, when the steering surface P is inclined with respect to the plane S as described above, the lower part of the steering unit 1 approaches the vicinity of the abdomen of the driver M. Therefore, when the driver M turns the steering unit 1, the elbow joint of the driver M and his / her abdomen are likely to interfere with each other, which may reduce the operability of the steering unit 1. In contrast, in this embodiment, the lower part of the steering unit 1 is provided with bent parts 1ax2, 1bx2 that bend forward from the lower end parts 1ax1b, 1bx1b of the general parts 1ax1, 1bx1. This allows the lower part of the steering unit 1 to be separated from the vicinity of the abdomen of the driver M, thereby preventing a reduction in the operability of the steering unit 1. Note that, here, the bent parts 1ax2, 1bx2 bending forward means that they bend at least forward with respect to the extension direction of the general parts 1ax1, 1bx1, and the bent parts 1ax2, 1bx2 do not necessarily have to extend forward in the fore-and-aft direction. That is, the bent portions 1ax2 and 1bx2 are configured so that the angle θ4 formed between the steering surface P and the bent portions 1ax2 and 1bx2 is a positive value when the direction away from the driver M is taken as positive. In this embodiment, the angle θ4 is set to 24.5 degrees.

[0029] Furthermore, the general portions 1ax1, 1bx1 and the bent portions 1ax2, 1bx2 of the steering unit 1 can be easily formed by changing the shape of the core metal 1w, etc. Therefore, according to the steering wheel 10 of this embodiment, even when the steering wheel 10 is mounted on a vehicle 50 in which the angle of the steering shaft 55 with respect to the horizontal plane H is small, the steering wheel 10 can reduce the burden on the wrists of the driver M when gripping the steering unit 1 with a simple configuration and prevent a decrease in the operability of the steering unit 1.

[0030] In this embodiment, the angle θ3 between the plane S perpendicular to the rotation axis R of the steering shaft 55 and the steering surface P is set to 25 degrees. This angle θ2 is normally set to 20 degrees, but is tilted by 8 degrees to compensate for the 12-degree tilt. The angle θ2 is further tilted by 17 degrees to take into account the operability of the steering unit 1. The sum of these 8 and 17 degrees results in the angle θ3 being 25 degrees. By setting the angle θ3 to a value obtained by subtracting the angle θ2 from at least 20 degrees, the strain on the wrists of the driver M when gripping the steering unit 1 can be reduced to the same level as normal. In other words, by setting θ3 ≧ 20 − θ2 (degrees), the strain on the wrists of the driver M when gripping the steering unit 1 can be reduced to more than normal. The angle θ3 is preferably set within the range of 0 degrees < θ3 ≦ 50 degrees.

[0031] In this embodiment, the bent portions 1ax2, 1bx2 of the steering unit 1 extend substantially parallel to a plane S perpendicular to the rotation axis R of the steering shaft 55. Here, "substantially parallel" includes a configuration in which the rear end faces 1ax2a, 1bx2a of the bent portions 1ax2, 1bx2 extend parallel to the plane S, as well as a configuration in which the rear end faces 1ax2a, 1bx2a of the bent portions 1ax2, 1bx2 extend with a deviation within a range of ±5 degrees from parallel. In this embodiment, the distance K3 between the plane S and the rear end faces 1ax2a, 1bx2a of the bent portions 1ax2, 1bx2 is set to 20.3 mm. With this configuration, the distance between the abdomen of the driver M and the bent portions 1ax2, 1bx2 becomes equivalent to the distance if the steering unit 1 were to be annular.

[0032] Although the present embodiment has been described with reference to the steering wheel 10 employing a steer-by-wire system, the present invention is not limited to this. That is, a configuration may be adopted in which the tires of the vehicle 50 are mechanically steered via the steering shaft 55 when the steering unit 1 is rotated and steered. However, when a steer-by-wire system is employed, the rotation angle of the steering unit 1 becomes relatively small, and the bent portions 1ax2 and 1bx2 tend to be positioned near the abdomen of the driver M in the direction of rotation of the steering unit 1, which is preferable because it further enhances the above-described effects.

[0033] Furthermore, in this embodiment, the present invention has been described by exemplifying the steering wheel 10 having the steering section 1 that extends generally linearly in the vertical direction, but the present invention is not limited to this and may be applied to steering sections 1 of other shapes. For example, even if the present invention is applied to a steering section 1 that is circular, the same effects as those described above can be obtained. [Explanation of symbols]

[0034] 1...Steering section, 1ax1, 1bx1...General section (first area), 1ax2, 1bx2...Bending section (second area), 1z...Cover member (grip section), 3...Boss section, 10...Steering wheel, 50...Vehicle, 55...Steering shaft (steering axis), H...Horizontal plane, M...Driver, P...Steering surface, R...Rotation axis, S...Plane (plane perpendicular to the rotation axis of the steering axis)

Claims

1. a boss portion connected to a steering shaft of a vehicle; a steering unit that is gripped by a driver and steered around the steering shaft, the steering unit having a first region that forms a steering surface that is inclined so as to lean forward with respect to a plane perpendicular to the rotation axis of the steering shaft, and a second region that bends forward from a lower end of the first region; Equipped with A steering wheel, wherein the second region extends to a lower end of the steering portion so as to separate the lower portion of the steering portion from the vicinity of the abdomen of the driver.

2. 2. The steering wheel according to claim 1, wherein at least a portion of the first region is disposed above the center of the boss portion in the vertical direction.

3. 3. The steering wheel according to claim 1, wherein the entire second region is disposed below the center of the boss portion in the vertical direction.

4. 2. The steering wheel according to claim 1, wherein the second region extends parallel to the plane or at an angle within a range of ±5 degrees relative to the plane.

5. 2. The steering wheel according to claim 1, wherein a grip portion having a higher friction coefficient than an inner end surface is provided on an outer end surface of the steering portion in the left-right direction.

6. 2. The steering wheel according to claim 1, wherein the steering wheel is mounted on the vehicle such that an angle of the steering axis relative to a horizontal plane is equal to or greater than 0 degrees and less than 20 degrees.

7. 2. The steering wheel according to claim 1, wherein the steering wheel is equipped with a sensor that detects the rotation angle of the steering portion, and is mounted on the vehicle to steer tires in accordance with the detection result of the sensor.

8. The steering section comprises a left steering section extending generally linearly in the vertical direction on the left side of the boss section, and a right steering section extending generally linearly in the vertical direction on the right side of the boss section, 2. The steering wheel according to claim 1, wherein the first area and the second area are arranged in the left steering section and the right steering section, respectively.

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