JP7798006B2 - Steering wheel - Google Patents

Description

The present invention relates to a steering wheel mounted on a vehicle.

A steering wheel installed in a vehicle has a boss portion connected to the steering shaft, which serves 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.

Furthermore, the space below the steering wheel, i.e., the space under the driver's feet, can be designed to be larger the smaller the angle of the steering shaft relative to the horizontal plane. In a configuration where 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 are more likely to be strained when gripping the steering unit.

Meanwhile, 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 wheel.

Furthermore, when the above configuration is adopted, the lower part of the steering unit approaches the driver's abdomen, which can easily cause interference between the driver's elbow joint and abdomen when the driver rotates the steering unit, potentially reducing the operability of the steering unit. In response to this, Patent Document 1 describes a configuration that provides a mechanism 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 driver's abdomen and preventing a reduction in the operability of the steering unit.

JP 2010-111245 A

In the configuration described in Patent Document 1, a mechanism including an actuator, motor, gears, etc. is provided to change the steering surface so that it approaches perpendicular to the horizontal plane as the rotation angle of the steering unit increases. The provision of such a mechanism complicates the steering wheel configuration, which may increase the number of parts and make assembly difficult.

The present invention aims to provide a steering wheel with a simple configuration that reduces the strain on the driver's wrists when gripping the steering section and prevents a decrease in the operability of the steering section, even when the steering wheel is installed in a vehicle with a small angle of the steering shaft relative to the horizontal plane.

A typical configuration of a steering wheel according to the present invention that solves the above problems is characterized by comprising a boss portion connected to the steering shaft of the vehicle, and a steering section that is gripped by the driver and rotated around the steering shaft, the steering section having a first region that forms a steering surface that is inclined forward relative 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.

The present invention provides a steering wheel with a simple configuration that reduces the strain on the driver's wrist when gripping the steering unit and prevents a decrease in the operability of the steering unit, even when the steering wheel is installed in a vehicle with a small angle of the steering shaft relative to the horizontal plane.

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. 1A and 1B are a front view and a cross-sectional view of a steering wheel; FIG. FIG. FIG. FIG. 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.

The following describes a steering wheel 10 according to one embodiment of the present invention. Note that the dimensions, materials, shapes, and relative positions of the components described below are not intended to limit the scope of this invention unless specifically stated otherwise.

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

In the following description, the directions described in relation to the steering wheel 10 refer to the directions when the steering wheel 10 is mounted on the vehicle 50 shown in Figure 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.

As shown in FIG. 1, the steering wheel 10 is mounted on the 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 consisting of a column tube 56a that partially covers the outer periphery of the steering shaft 55 and supports it, and a column cover 56b that covers the portion of the steering shaft 55 that protrudes rearward from the instrument panel 57. The steering wheel 10 is attached to the end of the steering shaft 55 that protrudes rearward from the instrument panel 57.

As shown in Figures 2 to 6, the steering wheel 10 has a boss portion 3 connected to the 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 located on the front side of the steering wheel 10 and approximately in the center of the steering wheel 10, and has an axial hole 3a through which the steering shaft 55 is inserted and fitted. With the tip of the steering shaft 55 inserted and fitted into the axial 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.

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 located in the space between the lower cover 5, which covers the front and side sides of the steering wheel 10, and the pad 4, which 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 other components are provided in the space between the pad 4 and the lower cover 5.

The steering unit 1 is located on both the left and right sides of the boss 3 and is gripped by the driver M. The steering unit 1 is composed of a left steering unit 1a extending generally vertically on the left side of the boss 3, and a right steering unit 1b extending generally vertically on the right side of the boss 3. The left steering unit 1a has a core 1w, a base material 1v covering the outer periphery of the core 1w, and a cover member 1z (grip portion) covering 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. The right steering unit 1b is symmetrical to the left steering unit 1a with respect to the boss 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) 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 these may be formed from 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 adhesively fixed to the outer periphery of the base material 1v. This cover member 1z is configured so that the outer end face of the steering unit 1 in the left-right direction 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 (Figure 2) of the portion of the left steering unit 1a and right steering unit 1b where the cover member 1z is provided 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 within the range of 110 mm≦K1≦130 mm.

Furthermore, the left steering unit 1a has a general portion 1ax1 (first region) extending rearward from the top to the bottom so as to be close to the driver M, and a bent portion 1ax2 (second region) bending forward from the lower end 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 be close to the driver M, and a bent portion 1bx2 (second region) bending forward from the lower end 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 entirety below the center of the boss portion 3. Note that the dotted line shown in Figure 5 is 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 bar 1w.

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

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, respectively, with screws 93. The left-right center of the upper connecting portion 7 is connected to a support metal plate (not shown) that supports the boss portion 3 with a screw (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 a screw (not shown). The right steering portion 1b and the right connecting portion 9 are connected with a screw (not shown). Additionally, the left and right connecting portions 8 and 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 unit 1 is connected to the boss portion 3 via the support metal plate that supports the upper connecting portion 7, the left and right connecting portions 8 and 9, and the boss portion 3.

In addition, the distance K2 (Figure 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 (Figure 4) 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 (Figure 4) 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 conventional steering wheels with annular steering units, 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 when the steering unit 1 is annular.

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

Next, the positional relationships of the various components that make up the steering wheel 10 will be described in detail. Figure 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 Figure 7 corresponds to Figure 1, with the horizontal plane H, the rotation axis R of the steering shaft 55, and the steering surface P inserted.

As shown in Figure 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 around 20 degrees. However, the smaller the angle θ2, the more space can be designed to accommodate the feet of the driver M, so in this embodiment, the angle θ2 is set smaller than usual. This angle θ2 is preferably set in the range 0 degrees < θ2 < 20 degrees.

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

In this embodiment, the steering surface P is tilted 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 section 1ax1 of the left steering unit 1a and the general section 1bx1 of the right steering unit 1b are configured to form a steering surface P that is tilted 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 driver M's feet and reducing the strain on the driver M's wrists when gripping the steering unit 1.

Furthermore, when the steering surface P is inclined relative to the plane S as described above, the lower part of the steering unit 1 approaches the abdomen of the driver M. This increases the likelihood of interference between the driver M's elbow joint and abdomen when the driver M rotates the steering unit 1, potentially reducing the operability of the steering unit 1. In response to this, in this embodiment, the lower part of the steering unit 1 is provided with bent parts 1ax2, 1bx2 that bend forward from the lower ends 1ax1b, 1bx1b of the general parts 1ax1, 1bx1. This allows the lower part of the steering unit 1 to be spaced away from the abdomen of the driver M, thereby preventing a reduction in the operability of the steering unit 1. Note that, here, "bent parts 1ax2, 1bx2 bending forward" means that they bend forward at least in the direction in which the general parts 1ax1, 1bx1 extend; it is not necessary for the bent parts 1ax2, 1bx2 to extend forward in the fore-and-aft direction. In other words, the bends 1ax2 and 1bx2 should be configured so that the angle θ4 between the steering surface P and the bends 1ax2 and 1bx2 is a positive value when the direction away from the driver M is defined as positive. In this embodiment, the angle θ4 is set to 24.5 degrees.

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, with the steering wheel 10 of this embodiment, even when it is installed in a vehicle 50 in which the angle of the steering shaft 55 with respect to the horizontal plane H is small, the simple configuration reduces the strain on the wrists of the driver M when gripping the steering unit 1 and prevents a decrease in the operability of the steering unit 1.

In addition, in this embodiment, the angle θ3 between the plane S perpendicular to the rotation axis R of the steering shaft 55 and the steering plane P is set to 25 degrees. This is because the angle θ2, which is normally set to 20 degrees, is tilted to 12 degrees, and is set to 8 degrees to compensate for this inclination. To account for the operability of the steering unit 1, the angle is further tilted by 17 degrees, resulting in angle θ3 of 25 degrees, which is the sum of 8 degrees and 17 degrees. By setting angle θ3 to a value obtained by subtracting 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 more than normal. It is preferable to set angle θ3 within the range of 0 degrees < θ3 ≦ 50 degrees.

In this embodiment, the bent portions 1ax2, 1bx2 of the steering unit 1 extend substantially parallel to a plane S that is perpendicular to the rotation axis R of the steering shaft 55. "Substantially parallel" here 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 they extend offset from parallel within a range of ±5 degrees. 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 is equivalent to the distance if the steering unit 1 were toricular.

Note that while this embodiment describes a steering wheel 10 that employs a steer-by-wire system, the present invention is not limited to this. That is, the vehicle 50's tires may be mechanically steered via the steering shaft 55 when the steering unit 1 is rotated. 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 are more likely 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 effects described above.

In addition, in this embodiment, the present invention has been described using as an example a steering wheel 10 having a 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, the same effects as described above can be obtained even when the present invention is applied to a steering section 1 that is circular.

1...Steering section, 1ax1, 1bx1...General section (first region), 1ax2, 1bx2...Bent section (second region), 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 (8)

a boss portion connected to a steering shaft of a vehicle;
a steering unit that is gripped by a driver and rotatably 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 . A steering wheel as described in claim 1, characterized in that at least a portion of the first region is positioned vertically above the center of the boss portion. A steering wheel as described in claim 1 or 2, characterized in that the entire second region is positioned vertically below the center of the boss portion. 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 . A steering wheel as described in claim 1, characterized in that the outer end surfaces of the steering section in the left-right direction are provided with grip portions having a higher coefficient of friction than the inner end surfaces. The steering wheel described in claim 1, characterized in that the steering wheel is mounted on the vehicle with the steering axis at an angle of 0 degrees or more and less than 20 degrees relative to the horizontal plane. The steering wheel of claim 1, characterized in that the steering wheel is equipped with a sensor that detects the rotation angle of the steering section and is mounted on the vehicle to steer the tires in accordance with the detection results of the sensor. The steering unit includes a left steering unit extending generally linearly in the vertical direction on the left side of the boss unit, and a right steering unit extending generally linearly in the vertical direction on the right side of the boss unit,
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.