JP2010052477A - Steering device and steering method of steering wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering device in which a steering wheel can be steered without using tie-rods and knuckle arms, and a method of steering the steering wheel. <P>SOLUTION: The steering device includes: a first gear 10, which converts the rotation of a steering shaft 6 that rotates around axial center according to the steering operation of a driver into rotation around the axis of vertical direction of a vehicle; a second gear 12, which is rotated around the axis of the vertical direction of the vehicle by the rotation of the first gear 10; and a steering force transmission part 14, which rockably connects the second gear 12 and a wheel support member 2 that supports the steering wheel W rotatably around the axis of the longitudinal direction of the vehicle and that of vehicle width direction. The steering force transmission part 14 rotates the wheel support member 2 around the axis of the vertical direction of the vehicle by the rotation of the second gear 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a steering device and a steering wheel steering method for steering a steered wheel according to a driver's steering operation.

As a conventional steering device, for example, as described in Patent Document 1, there is a device that connects a steered wheel and a tie rod via a knuckle arm. The knuckle arm extends in the vehicle front-rear direction from the center of rotation of the steering wheel.
JP-A-4-262971

In the steering device described in Patent Document 1, the tie rod is displaced according to the steering operation of the driver, and the steered wheels are steered via the knuckle arm. For this reason, there is a possibility that the steering range of the steered wheel is restricted due to interference between the steered wheel, the tie rod, and the knuckle arm.
The present invention has been made paying attention to the above problems, and provides a steering device and a steering wheel steering method capable of steering a steered wheel without using a tie rod and a knuckle arm. Let it be an issue.

  In order to solve the above problems, the present invention provides a steering device that steers a steered wheel according to a driver's steering operation by rotating a steering shaft extending in the vehicle width direction according to the steering operation. The rotation of the steering shaft is converted into the rotation of the steering wheel about the vehicle vertical axis through the first gear and the second gear arranged on the link member.

  According to the present invention, the rotation of the steering shaft according to the driver's steering operation can be converted into the rotation of the wheel support member via the first gear and the second gear. For this reason, it becomes possible to steer the steered wheels without using tie rods and knuckle arms.

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described with reference to the drawings.
(First embodiment)
(Constitution)
First, the configuration of the steering device 1 will be described with reference to FIGS. 1 to 5.
FIG. 1 is a top view showing a steering apparatus 1 of the present embodiment. FIG. 2 is a view taken in the direction of arrow II in FIG. 1 and shows the steering device 1 as seen from the rear in the vehicle front-rear direction.
The steering device 1 is a device that steers the steered wheels W according to a steering operation of a driver (not shown). In the present embodiment, the steered wheel W is a front wheel.

As shown in FIGS. 1 and 2, the steering device 1 includes a wheel support member 2, a link member 4, a steering shaft 6, a steering means 8, and a steering force transmission unit 14.
The wheel support member 2 rotatably supports the steering wheel W and is connected to the lower end of the strut 18 including the shock absorber 16. That is, in the present embodiment, a vehicle including the steering device 1 is a vehicle including a strut suspension. Further, in FIG. 2, a vehicle body that connects the upper ends of the struts 18 is shown with a symbol B.

The link member 4 is formed by a lower link disposed between the wheel support member 2 and the vehicle body side member 20 below the center of rotation of the steering wheel W in the vehicle vertical direction. The link member 4 is formed in a structure having a space (internal space) inside. In the present embodiment, the vehicle body side member 20 is a subframe.
Moreover, the link member 4 is a shape which has two vehicle body side member connection parts in one end part, and has one wheel support member connection part in the other end seeing from the vehicle up-down direction. The wheel support member connecting portion extends toward the steered wheel W.

  The two vehicle body side member connection portions are connected to the vehicle body side member 20 at two vehicle body side connection points L that are separated from each other in the vehicle front-rear direction. Specifically, the two vehicle body side member connecting portions are connected to the vehicle body side member 20 via two bushes 22 that are spaced apart from each other in the vehicle front-rear direction. In the drawings and the following description, of the two vehicle body side connection points L, the vehicle body side connection point L disposed in front of the vehicle front-rear direction is referred to as a vehicle body side connection point LF. Similarly, of the two vehicle body side connection points L, the vehicle body side connection point L arranged behind the vehicle front-rear direction is referred to as a vehicle body side connection point LR. In the drawings and the following description, of the two bushes 22, the bush 22 constituting the vehicle body side connection point LF is referred to as a bush 22F, and the bush 22 constituting the vehicle body side connection point LR is referred to as a bush 22R. Describe.

  The bushes 22F and 22R are configured by interposing an elastic body made of a rubber body between an outer cylinder and an inner cylinder arranged in a nested manner. In the present embodiment, as an example, a case will be described in which the outer cylinder is fixed to two vehicle body side member connecting portions via bolts or the like (not shown) and the inner cylinder is fixed to the vehicle body side member 20. Thereby, the vehicle body side member 20 and the link member 4 are connected so as to be swingable via the elastic bodies provided in the bushes 22F and 22R. That is, one end portion of the link member 4 is connected to the vehicle body side member 20 so as to be swingable.

The link member 4 includes a first gear 10 and a second gear 12.
The first gear 10 is formed by, for example, a spur gear, and meshes with the shaft-side gear 24 in a state where the rotation shaft is directed in the vehicle vertical direction. Therefore, the first gear 10 converts the rotation of the steering shaft 6 into rotation about the vehicle vertical axis. In the drawing, the rotation axis of the first gear 10 is indicated by a one-dot chain line S1. Further, the direction of rotation of the first gear 10 is indicated by a bidirectional arrow A3.

Further, the first gear 10 is disposed on the steered wheel W side with respect to the steering shaft 6, and is disposed at a position outside the vehicle width direction with respect to the vehicle body side member 20 of the link member 4.
The first gear 10 is attached to the link member 4. Specifically, it is attached to the link member 4 in a state of being arranged in the internal space of the link member 4. Thereby, the first gear 10 is disposed at a position overlapping the link member 4 when viewed from the vehicle front-rear direction.

  Similar to the first gear 10, the second gear 12 is formed by, for example, a spur gear, and meshes with the first gear 10 in a state where the rotation shaft is directed in the vehicle vertical direction. Accordingly, the second gear 12 rotates around the vehicle vertical axis by the rotation of the first gear 10. In the drawing, the rotation axis of the second gear 12 is indicated by a one-dot chain line S2. The direction of rotation of the second gear 12 is indicated by a bidirectional arrow A4.

Further, the second gear 12 is arranged on the steered wheel W side with respect to the first gear 10. Thereby, the steering shaft 6, the first gear 10, and the second gear 12 are arranged in the order of the steering shaft 6, the first gear 10, and the second gear 12 from the vehicle body side member 20 side to the steering wheel W side.
The second gear 12 is attached to the link member 4 in the same manner as the first gear 10. Specifically, it is attached to the link member 4 in a state of being arranged in the internal space of the link member 4. Accordingly, the second gear 12 is arranged at a position overlapping the link member 4 when viewed from the vehicle front-rear direction, like the first gear 10.
As described above, the steering shaft 6, the first gear 10, and the second gear 12 are arranged at positions that overlap the link member 4 when viewed from the vehicle front-rear direction.

The steering shaft 6 is a rod-like member that can rotate about its axis with its axis directed in the vehicle width direction, and one end portion is disposed between the steering wheel W and the vehicle body side member 20. That is, the steering shaft 6 extends in the vehicle width direction. Here, the one end portion of the steering shaft 6 is an end portion on the steering wheel W side. In the drawing, the rotation direction of the steering shaft 6 is indicated by a bidirectional arrow A1.
The steering shaft 6 is disposed in the internal space of the link member 4. Thereby, the steering shaft 6 is disposed at a position overlapping the link member 4 when viewed from the vehicle front-rear direction.

A shaft side gear 24 is attached to the end of the steering shaft 6 on the side of the steering wheel W. The shaft side gear 24 is a gear whose outer peripheral surface is inclined with respect to the rotation axis of the steering shaft 6, such as a bevel gear. Specifically, the gear has a shape whose outer diameter decreases from the vehicle body side member 20 toward the steering wheel W.
The end of the steering shaft 6 on the vehicle body side member 20 side is connected to the steering means 8 via a pivot member 26 that can rotate about the vehicle longitudinal axis. Thereby, the steering shaft 6 and the steering means 8 are connected in a state in which the steering shaft 6 and the steering means 8 can rotate about the vehicle longitudinal axis.

The pivot member 26 has a pivot point PP.
The pivot point PP is arranged on a straight line passing through the vehicle body side connection point LF and the vehicle body side connection point LR. Specifically, the pivot point PP is disposed between the vehicle body side connection point LF and the vehicle body side connection point LR. Thereby, the connection point of the steering shaft 6 and the steering means 8 is arrange | positioned on the straight line which passes through the two vehicle body side connection points LF and LR. In the drawing, a straight line passing through the vehicle body side connection point LF and the vehicle body side connection point LR is indicated by a one-dot chain line T.

  The steering means 8 includes a steering wheel disposed in a driver's seat (not shown), and a rotating shaft 8A connected to the steering wheel via a gear (not shown). The end of the rotating shaft 8A is connected to the steering shaft 6 via a pivot member 26. As a result, when the driver operates the steering wheel, the rotation shaft 8A rotates through the rotation of the gear according to this operation. Therefore, the steering means 8 rotates the steering shaft 6 according to the driver's steering operation. In the figure, the direction of rotation of the rotary shaft 8A is indicated by a bidirectional arrow A2.

Hereinafter, the configuration of the steering force transmission unit 14 will be described with reference to FIGS. 1 and 2 and FIGS. 3 to 5.
FIG. 3 is an enlarged view of a range surrounded by a circle III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. In addition, in FIG. 4, illustrations other than the 2nd gearwheel 12 and the steering force transmission part 14 are abbreviate | omitted for description. Similarly, in FIG. 5, illustrations other than the steering force transmission unit 14 are omitted.

As shown in FIGS. 3 to 5, the steering force transmission unit 14 includes an outer member 28, an inner member 30, and a plurality of rolling elements 32.
The outer member 28 includes a recess 34.
The recess 34 is formed in a hemispherical shape with the opening directed upward in the vehicle vertical direction, and is disposed in the internal space of the link member 4. That is, the outer member 28 has an internal space. Further, the outer member 28 is supported by the link member 4 via the bearing member 36 and the support shaft 38.

A plurality of outer member-side rolling element rolling grooves 40 are formed on the inner surface of the recess 34.
Each outer member side rolling element rolling groove 40 is formed in a shape extending radially when viewed from the vehicle vertical direction. That is, a plurality of outer member-side rolling element rolling grooves 40 extending radially when viewed from the vehicle vertical direction are formed on the inner surface of the recess 34.
Further, an outward member side protrusion 42 is provided on the inner surface of the recess 34.

The outer member side protrusion 42 protrudes toward the rotation axis S <b> 2 of the second gear 12 from the outer member side rolling element rolling groove 40. Specifically, the outer member side protruding portion 42 is provided in a portion between the adjacent outer member side rolling element rolling grooves 40 on the inner surface of the concave portion 34.
The outer surface of the recess 34 is connected to the second gear 12 over the entire circumferential direction of the second gear 12. Specifically, an opening is formed on the inner diameter side of the second gear 12, and the recess 34 is fixed in the opening.

As a result, the outer surface of the recess 34 is connected to the second gear 12. Specifically, the outer surface of the recess 34 is connected to the second gear 12 so that the outer member 28 and the second gear 12 rotate about the same axis.
The bearing member 36 includes an outer ring 36A, an inner ring 36B, and a plurality of bearing balls 36C disposed so as to be able to roll between the outer ring 36A and the inner ring 36B. The bottom surface of the outer ring 36 </ b> A is connected to the inner surface of the link member 4.

The support shaft 38 is arranged with the shaft directed in the vehicle vertical direction. An outer member 28 is attached to the upper end portion of the support shaft 38. The lower end portion of the support shaft 38 is attached to the inner diameter surface of the inner ring 36 </ b> B included in the bearing member 36. As a result, the support shaft 38 is coupled to the link member 4 via the bearing member 36.
The inner member 30 includes a hemispherical portion 44.

The hemispherical portion 44 is formed in a hemispherical shape having a curved surface and a flat surface, and is disposed opposite to the concave portion 34. Specifically, the hemispherical portion 44 is disposed in the concave portion 34 with the inner surface of the concave portion 34 and the curved surface of the hemispherical portion 44 facing each other.
A plurality of inner member side rolling element rolling grooves 46 are formed on the curved surface of the hemispherical portion 44.
Each inner member-side rolling element rolling groove 46 is formed to face the outer member-side rolling element rolling groove 40. Therefore, the hemispherical portion 44 has a plurality of inner member-side rolling element rolling grooves 46 that face the outer member-side rolling element rolling grooves 40.

In addition, an inward member side protruding portion 48 is provided on the curved surface of the hemispherical portion 44.
The inward member side protruding portion 48 protrudes to the inner surface of the recess 34 from the inward member side rolling element rolling groove 46. Specifically, the inward member side protruding portion 48 is provided in a portion between the adjacent inner member side rolling element rolling grooves 46 in the curved surface of the hemispherical portion 44.
Further, the outer member side protruding portion 42 and the inner member side protruding portion 48 are formed such that a gap C formed between the outer member side protruding portion 42 and the inner member side protruding portion 48 is a diameter D of the rolling element 32. It forms so that it may become less. As a result, the minimum gap between the inner surface of the concave portion 34 and the hemispherical portion 44 is made smaller than the diameter of the rolling element 32.

On the plane of the hemispherical portion 44, a rod-shaped transmission shaft 50 whose axis is directed in the vehicle vertical direction is attached. Specifically, the lower end surface of the transmission shaft 50 is attached to the plane of the hemispherical portion 44.
The upper end side of the transmission shaft 50 protrudes upward in the vehicle vertical direction from the internal space of the link member 4 and is attached to the wheel support member 2. Specifically, the upper end side of the transmission shaft 50 is passed through the opening formed in the opening of the recess 34 and the surface of the link member 4 facing the wheel support member 2, and is attached to the wheel support member 2.

Thereby, the plane of the hemispherical part 44 is connected to the wheel support member 2. Specifically, the plane of the hemispherical portion 44 is connected to the wheel support member 2 so that the inner member 30 and the wheel support member 2 rotate about the same axis.
A boot 52 formed using an elastic material such as rubber is disposed between the link member 4 and the wheel support member 2. The boot 52 is formed with a through hole that penetrates the upper end side of the transmission shaft 50. Furthermore, the boot 52 is attached to the link member 4 so as to close an opening formed on the surface of the link member 4 facing the wheel support member 2. Thereby, the boot 52 suppresses entry of mud or the like into the link member 4.

  Each rolling element 32 is formed of, for example, a steel ball and is disposed between the concave portion 34 and the hemispherical portion 44. Specifically, the outer member side rolling element rolling groove 40 and the inner member side rolling element rolling groove 46 are loaded so as to be freely rollable. In addition, between the rolling elements 32 adjacent between the outer member side rolling element rolling groove 40 and the inner member side rolling element rolling groove 46, the cages 54 that prevent the rolling elements 32 from contacting each other. Place. Further, in the gap formed between the outer member side rolling element rolling groove 40 and the inner member side rolling element rolling groove 46, together with the rolling element 32 and the cage 54, a lubricant such as grease (not shown). )).

Therefore, by configuring the outer member 28, the inner member 30 and the rolling element 32 as described above, the outer member 28, the inner member 30 and the rolling element 32 are rotated by the rotation of the second gear 12. A steering force transmission mechanism 56 that rotates the wheel support member 2 about the vehicle vertical axis is formed.
Specifically, when the first gear 10 and the second gear 12 are rotated by the rotation of the steering shaft 6, the recess 34 is rotated by the rotation of the second gear 12.

At this time, a gap C formed between the outer member side protruding portion 42 and the inner member side protruding portion 48 is set to be smaller than the diameter D of the rolling element 32. For this reason, when the recessed part 34 rotates, the outer member side protrusion part 42 presses the inner member side protrusion part 48 via the rolling element 32. This pressing force is a pressing force for rotating the hemispherical portion 44.
As described above, the steering force transmission unit 14 includes the steering force transmission mechanism 56 that rotates the wheel support member 2 around the vehicle vertical axis by the rotation of the second gear 12.
The steering force transmission unit 14 connects the wheel support member 2 and the second gear 12 so as to be swingable about the vehicle longitudinal axis and the vehicle width axis. As a result, the other end of the link member 4 is slidably connected to the steered wheels W via the steering force transmission unit 14.

(Operation)
Next, the operation of the steering device 1 will be described with reference to FIGS.
First, an operation for changing the traveling direction of the vehicle when the vehicle including the steering device 1 is traveling will be described.
When the vehicle equipped with the steering device 1 is traveling, for example, when the driver operates the steering wheel during a right turn or a left turn, the steering shaft 6 is rotated around the axis by the steering means 8 (see FIG. 1 and FIG. 1). (See Figure 2)
When the steering shaft 6 rotates around the axis, the shaft side gear 24 rotates around the axis of the steering shaft 6 (see FIGS. 1 and 2). Then, the first gear 10 that meshes with the shaft-side gear 24 rotates around the vehicle vertical axis. As a result, the rotation of the steering shaft 6 is converted into rotation around the vehicle vertical axis (see FIGS. 1 and 2).

When the first gear 10 rotates about the vehicle vertical axis, the second gear 12 that meshes with the first gear 10 rotates about the vehicle vertical axis by the rotation of the first gear 10 (FIGS. 1 to 4). reference).
When the second gear 12 rotates about the vehicle vertical axis, the outer member 28 connected to the second gear 12 rotates about the vehicle vertical axis (see FIG. 3). Here, since the support shaft 38 that supports the concave portion 34 included in the outer member 28 is connected to the link member 4 via the bearing member 36, the concave portion 34 is moved relative to the link member 4 by the rotation of the bearing member 36. It rotates smoothly (see FIG. 3).

At this time, an outer member-side protruding portion 42 that protrudes toward the rotation shaft S2 of the second gear 12 from the plurality of outer member-side rolling element rolling grooves 40 is provided on the inner surface of the recess 34 (FIG. 4). reference).
In addition, the curved surface of the hemispherical portion 44 included in the inner member 30 is opposed to the outer member-side rolling element rolling groove 40, and is closer to the inner surface of the recess 34 than the plurality of inner member-side rolling element rolling grooves 46. A plurality of inner member side projecting portions 48 that project is provided (see FIG. 4). In addition, the gap C formed between the outer member side protrusion 42 and the inner member side protrusion 48 is less than the diameter D of the rolling element 32 (see FIG. 4).

For this reason, when the concave portion 34 is rotated around the vehicle vertical axis by the rotation of the second gear 12, this rotation is transmitted from the outer member side protruding portion 42 via the rolling elements 32 to the inner member side protruding portion 48. (See FIG. 3).
As a result, the hemispherical portion 44 rotates around the vehicle vertical axis, and the transmission shaft 50 attached to the hemispherical portion 44 rotates around the vehicle vertical axis (see FIGS. 3 and 4).

When the transmission shaft 50 attached to the hemispherical portion 44 rotates about the vehicle vertical axis, the wheel support member 2 connected to the transmission shaft 50 rotates about the vehicle vertical axis. And the steering wheel W which the wheel support member 2 supports rotatably rotates around a vehicle up-down direction axis | shaft (refer FIGS. 1-3). Thereby, the advancing direction of the vehicle provided with the steering device 1 changes in a direction according to the steering operation of the steering wheel by the driver.
As described above, when the traveling direction of the vehicle is changed during traveling of the vehicle including the steering device 1 of the present embodiment, the rotation of the steering shaft 6 according to the steering operation of the driver is performed on the wheel support member 2. Converting to rotation, the steered wheel W is steered.

Here, with reference to the steering apparatus 1 of a comparative example, the effect | action of the steering apparatus 1 of this embodiment is demonstrated. The steering device 1 of the comparative example is configured to convert the rotation of the steering shaft 6 into the rotation of the wheel support member 2 as in the steering device 1 of the present embodiment.
First, with reference to FIG.6 and FIG.7, the structure of the steering apparatus 1 of a comparative example is demonstrated.
FIG. 6 is a top view showing a steering device 1 of a comparative example. FIG. 7 is a view taken in the direction of the arrow VII in FIG. 6, and is a view of the steering device 1 of the comparative example viewed from the rear in the vehicle front-rear direction.
As shown in FIGS. 6 and 7, the steering device 1 of the comparative example is different from the steering device 1 of the present embodiment in that the wheel support member 2 is replaced with the first wheel support member 2A, the second wheel support member 2B, Are formed in combination.

The first wheel support member 2 </ b> A is connected to the steering wheel W.
The second wheel support member 2 </ b> B is connected to the vehicle body side member 20 via the link member 4.
Further, the second wheel support member 2B supports the first wheel support member 2A via the first gear 10 and the second gear 12 so as to be rotatable about the vehicle vertical axis. Thereby, the rotational force of the steering shaft 6 is converted into the rotational force around the vehicle vertical axis through the first gear 10 and the second gear 12.

Further, unlike the steering apparatus 1 of the present embodiment, the steering apparatus 1 of the comparative example includes a restraining link 58 that connects the second wheel support member 2B and the link member 4. Accordingly, the rotation of the second wheel support member 2B around the vehicle vertical axis is restricted, and the rotation angle of the first wheel support member 2A is set as the steering angle of the steered wheels W.
As described above, in the steering device 1 of the comparative example, unlike the steering device 1 of the present embodiment, the wheel support member 2 is formed from two members (the first wheel support member 2A and the second wheel support member 2B).

Further, unlike the steering device 1 of the present embodiment, the steering device 1 of the comparative example includes a restraining link 58.
Therefore, in the steering device 1 of the comparative example, the number of parts increases as compared with the steering device 1 of the present embodiment, and there is a possibility that problems such as a complicated structure and an increased manufacturing cost may occur.

  On the other hand, in the steering device 1 of the present embodiment, the rotation of the steering shaft 6 is converted into the rotation of the wheel support member 2 via the first gear 10, the second gear 12, and the steering force transmission unit 14, The wheel support member 20 can be formed from a single member. In addition, since the wheel support member 20 can be formed of a single member, the restraint link can be eliminated as compared with the steering device 1 of the comparative example.

Next, an operation when an external force is applied to the steered wheel W, such as when the steered wheel W comes into contact with a road surface projection during traveling of the vehicle including the steering device 1, will be described.
When an external force is applied to the steered wheel W, such as when the steered wheel W comes into contact with a road surface projection, this external force causes the steered wheel W to move around the axis in the vehicle longitudinal direction (camber change), There may be a displacement (caster change) around the axis in the width direction.

  Here, the outer member 28 has a plurality of outer member-side rolling element rolling grooves 40 that extend radially when viewed from the vehicle vertical direction (see FIGS. 4 and 5). On the other hand, the inner member 30 has a plurality of inner member-side rolling element rolling grooves 46 facing the outer member-side rolling element rolling grooves 40 (see FIGS. 4 and 5). In addition to this, each rolling element 32 is arranged to roll freely between the outer member side rolling element rolling groove 40 and the inner member side rolling element rolling groove 46 (see FIGS. 4 and 5). .

For this reason, even if a camber change occurs in the steering wheel W and the wheel support member 2 and the outer member 28 and the inner member 30 cause relative displacement about the axis in the vehicle front-rear direction, this relative displacement is It becomes possible to allow through the rolling of each rolling element 32 (see FIGS. 1 to 5).
Similarly, even if a caster change occurs in the steering wheel W and the wheel support member 2, and the outer member 28 and the inner member 30 cause relative displacement around the axis in the vehicle width direction, this relative displacement is It becomes possible to allow through the rolling of each rolling element 32 (see FIGS. 1 to 5).

Here, each outer member-side rolling element rolling groove 40 and each inner member-side rolling element rolling groove 46 have a shape extending radially when viewed from the vehicle vertical direction. For this reason, even if the steering angle of the steered wheels W is changed, it is possible to allow relative displacement between the outer member 28 and the inner member 30 caused by a camber change or a caster change.
Therefore, even if a camber change or a caster change occurs in the steering wheel W due to an external force applied to the steering wheel W during traveling of the vehicle, the wheel support member 2 and the second gear 12 are moved in the vehicle longitudinal direction and the vehicle width direction. It is possible to allow these changes by swinging around the axis toward the.

In addition to the camber change and caster change described above, when an external force is applied to the steered wheels W, the external force causes the vehicle up-down direction between the link member 4 and the vehicle body side member 20 when viewed from the vehicle front-rear direction. Relative displacement may occur.
Here, the link member 4 is swingably connected to the vehicle body side member 20 at two vehicle body side connection points LF and vehicle body side connection points LR that are separated in the vehicle longitudinal direction (see FIG. 1). In addition, the pivot point PP of the pivot member 26 is arranged on a straight line passing through the vehicle body side connection point LF and the vehicle body side connection point LR, and the pivot point PP is replaced with two vehicle body side connection points LF, PR. (See FIG. 1).

Therefore, even when a relative displacement in the vehicle vertical direction occurs between the link member 4 and the vehicle body side member 20 as viewed from the front-rear direction of the vehicle due to an external force applied to the steered wheels W when the vehicle is running, The displacement can be allowed by the rotation of the pivot member 26.
As described above, the steering wheel steering method implemented by the operation of the steering device 1 of the present embodiment causes the first gear 10 to rotate the steering shaft 6 according to the driver's steering operation around the vehicle vertical axis. Convert to rotation to. In addition, the rotation of the first gear 10 causes the second gear 12 to rotate about the vehicle vertical axis. Further, the second gear 12 and the wheel support member 2 that rotatably supports the steered wheel W are connected so as to be swingable about the vehicle longitudinal axis and the vehicle width axis, and the second gear 12 rotates. Thus, the wheel support member 2 is rotated about the vehicle vertical axis.

(Effects of the first embodiment)
(1) In the steering device of the present embodiment, the link member rotates about the vehicle vertical axis by rotation of the first gear and the first gear that converts rotation of the steering shaft into rotation about the vehicle vertical axis. A second gear.
In addition to this, the steering force transmission unit that slidably connects the other end of the link member to the steering wheel includes a steering force transmission mechanism that rotates the wheel support member about the vehicle vertical axis by the rotation of the second gear. .
Therefore, the rotation of the steering shaft according to the driver's steering operation can be converted into the rotation of the wheel support member via the first gear, the second gear, and the steering force transmission unit.

As a result, the steered wheels can be steered without using tie rods and knuckle arms, and the steered area of the steered wheels can be increased, so that the steering angle of the steered wheels can be increased. .
In addition, even if a camber change or caster change occurs in the steered wheel due to an external force applied to the steered wheel, the wheel support member and the second gear swing around the axis in the vehicle longitudinal direction and the vehicle width direction. Thus, these changes can be allowed.

(2) In the steering device of the present embodiment, the rotation of the steering shaft according to the driver's steering operation is converted into the rotation of the wheel support member via the first gear, the second gear, and the steering force transmission unit. Is possible.
As a result, the wheel support member can be formed from a single member, the increase in the number of parts can be prevented, the structure can be simplified, and the manufacturing cost can be reduced.

(3) In the steering device according to the present embodiment, the wheel support member can be formed by one member, and therefore, there is no need to provide a restraining link as in the case of forming the wheel support member from two members. .
As a result, compared with the case where the wheel support member is formed from two members, an increase in the number of parts can be prevented, the structure can be simplified, and the manufacturing cost can be reduced.
Further, unlike the case where the wheel support member is formed from two members, it is possible to adopt a configuration in which the restraining link is eliminated. For this reason, it is possible to increase the region for displacing the steered wheels, and it is possible to increase the steering angle of the steered wheels.

Furthermore, it is possible to reduce the weight of the steering device as compared with the case where the wheel support member is formed from two members. For this reason, it is possible to maintain advantages such as low fuel consumption for a vehicle including a steering device.
Further, the number of parts of the steering device can be reduced as compared with the case where the wheel support member is formed of two members. For this reason, it becomes possible to increase the clearance formed in the lower part of the vehicle body, and to improve the degree of freedom in designing the vehicle.

(4) In the steering device of the present embodiment, one end of the link member is connected to the vehicle body side member at two vehicle body side connection points that are separated in the vehicle front-rear direction, and the steering shaft and the steering means are connected to the vehicle front and rear. Connect in a rotatable state around the direction axis. In addition, the connection point between the steering shaft and the steering means is arranged on a straight line passing through the two vehicle body side connection points.
Therefore, even when a relative displacement in the vehicle vertical direction occurs between the link member and the vehicle body side member as viewed from the front-rear direction of the vehicle due to an external force applied to the steered wheels during traveling of the vehicle, the relative displacement Can be allowed by rotation of the pivot member.
As a result, the durability of the steering shaft and the steering means can be improved, and the durability of the steering device can be improved.

(5) In the steering device of the present embodiment, the steering shaft, the first gear, and the second gear are arranged in the internal space of the link member. As a result, the steering shaft, the first gear, and the second gear are arranged at positions that overlap the link member when viewed from the front-rear direction of the vehicle.
As a result, it is possible to increase the clearance formed in the lower part of the vehicle body as compared with the case where the steering shaft, the first gear, and the second gear are arranged at positions that do not overlap with the link member when viewed from the vehicle front-rear direction. Become. For this reason, it becomes possible to improve the design freedom of vehicles.
Further, the displacement of the steering shaft, the first gear, and the second gear in the vehicle vertical direction can be shared by the link member. For this reason, it becomes possible to suppress the relative displacement of the steering shaft, the first gear, the second gear, and the link member.

(6) In the steering device according to the present embodiment, the steering force transmission unit includes an outer member having a hemispherical recess whose opening is directed upward in the vehicle vertical direction, and an inner side having a hemispherical portion opposed to the recess. A member, and a plurality of rolling elements disposed between the concave portion and the hemispherical portion.
In addition, a plurality of outer member side rolling element rolling grooves extending radially from the vehicle vertical direction are formed on the inner surface of the recess, and the outer member side rolling element rolling grooves are opposed to the curved surface of the hemisphere portion. A plurality of inner member-side rolling element rolling grooves are formed. In addition, a plurality of rolling elements are slidably loaded between the outer member side rolling element rolling groove and the inner member side rolling element rolling groove, and the minimum gap between the concave portion and the hemispherical portion is set to the rolling member. Should be less than the diameter of the moving object Furthermore, the outer surface of the recess is connected to the second gear, and the flat surface of the hemisphere is connected to the wheel support member.

For this reason, when the outer member rotates around the vehicle vertical axis by the rotation of the second gear, this rotation is transmitted from the recess to the hemispherical part via each rolling element, and the inner member and the wheel support member are Rotate around the vehicle vertical axis.
Further, even if a camber change or a caster change occurs in the steering wheel and the wheel support member, and the outer member and the inner member cause a relative displacement about the axis in the vehicle longitudinal direction or the vehicle width direction, this relative displacement Can be allowed through the rolling of each rolling element.

Furthermore, since the plurality of outer member-side rolling element rolling grooves and the plurality of inner member-side rolling element rolling grooves extend radially when viewed from the vehicle up-down direction, they do not depend on the steering angle of the steered wheels. The relative displacement of the steering wheel and the wheel support member can be allowed through the rolling of each rolling element.
As a result, the configuration of the steering force transmission unit is rotated around the vehicle vertical axis by the rotation of the second gear without an actuator such as a motor, and is swung around the axis in the vehicle longitudinal direction and the vehicle width direction. It becomes possible to make it a movable configuration.

(7) In the steered wheel steering method of the present embodiment, the rotation of the steering shaft according to the steering operation of the driver is converted into the rotation about the vehicle vertical axis by the first gear, and further the rotation of the first gear To rotate the second gear.
In addition to this, the second gear and a wheel support member that rotatably supports the steering wheel are connected so as to be swingable about the vehicle longitudinal axis and the vehicle width axis, and by rotation of the second gear, The wheel support member is rotated about the vehicle vertical axis.

For this reason, it becomes possible to transmit the rotation of the steering shaft according to the steering operation of the driver to the wheel support member via the first gear, the second gear, and the steering force transmission unit.
As a result, the wheel support member can be rotated about the vehicle vertical axis in accordance with the driver's steering operation.
In addition, even if a camber change or caster change occurs in the steered wheel due to an external force applied to the steered wheel, the wheel support member and the second gear swing around the axis in the vehicle longitudinal direction and the vehicle width direction. Thus, these changes can be allowed.

(Application examples)
(1) In the steering device 1 of the present embodiment, the pivot point PP of the pivot member 26 is arranged on a straight line passing through the two vehicle body side connection points LF and PR, but the present invention is not limited to this. That is, the pivot point PP of the pivot member 26 may be offset from the straight line passing through the two vehicle body side connection points LF and PR in the vehicle width direction. However, as in the steering device 1 of the present embodiment, the arrangement of the pivot point PP causes the relative displacement in the vehicle vertical direction that occurs between the link member 4 and the vehicle body side member 20 to be caused by the rotation of the pivot member 26. This is preferable because it can be tolerated.

(2) In the steering device 1 according to the present embodiment, the steering shaft 6, the first gear 10, and the second gear 12 are arranged at positions overlapping the link member 4 when viewed from the front-rear direction of the vehicle. is not. That is, for example, the steering shaft 6, the first gear 10, and the second gear 12 may be disposed above the link member 4 in the vehicle vertical direction. However, it is preferable to dispose the steering shaft 6, the first gear 10, and the second gear 12 as in the steering device 1 of the present embodiment because the degree of freedom in designing the vehicle can be improved. .

(3) In the steering apparatus 1 according to the present embodiment, the steering force transmission unit 14 includes the outer member 28, the inner member 30, and the plurality of rolling elements 32. However, the present invention is not limited to this. Instead, the steering force transmission unit 14 may be constituted by a universal joint, for example. In short, the configuration of the steering force transmission unit 14 is configured to connect the second gear 12 and the wheel support member 2 so as to be swingable about the vehicle longitudinal axis and the vehicle width axis, and to rotate the second gear 12. Thus, the wheel support member 2 may be configured to rotate about the vehicle vertical axis.

(4) In the steering device 1 of the present embodiment, the steering wheel W is the front wheel, but the present invention is not limited to this, and the steering wheel W may be the rear wheel. The steered wheels W may be front wheels and rear wheels.
(5) In the steering device 1 of the present embodiment, the steering shaft 6, the first gear 10, and the second gear 12 are moved from the vehicle body side member 20 side to the steering wheel W side. The gears 12 are arranged in this order, but the present invention is not limited to this. That is, for example, as shown in FIG. 8, the first gear 10 and the second gear 12 may be arranged in parallel along the vehicle longitudinal direction. FIG. 8 is a view showing a modified steering apparatus 1.

(6) In the steering device 1 of the present embodiment, the pivot point PP of the pivot member 26 is disposed between the vehicle body side connection point LF and the vehicle body side connection point LR. However, the present invention is not limited to this. That is, for example, as shown in FIG. 9, the pivot point PP of the pivot member 26 may be arranged in front of the vehicle body side connection point LF in the front-rear direction of the vehicle. Similarly, the pivot point PP of the pivot member 26 may be disposed behind the vehicle body side connection point LR in the vehicle front-rear direction. FIG. 9 is a view showing a steering apparatus 1 according to a modification.

(7) In the steering device 1 of the present embodiment, the vehicle including the steering device 1 is a vehicle including a strut suspension, but is not limited thereto. That is, for example, as shown in FIG. 10, as a vehicle including a wishbone type suspension including an upper link 60 that arranges the vehicle including the steering device 1 above the rotation center of the steering wheel W in the vehicle vertical direction. Also good. In addition, FIG. 10 is a figure which shows the steering apparatus 1 of a modification.

(8) In the steering device 1 of the present embodiment, the link member 4 is formed by a single member, but the present invention is not limited to this. That is, the link member 4 may be formed by combining, for example, a front link formed in a columnar shape and a rear link formed in a trapezoidal shape when viewed from the vehicle vertical direction. In this case, for example, only the rear link supports the first gear 10 and the second gear 12 so as to be rotatable relative to the rear link.

(Second embodiment)
Next, a second embodiment of the present invention will be described.
(Constitution)
First, the configuration of the steering device 1 of the present embodiment will be described with reference to FIG.
FIG. 11 is a diagram illustrating a configuration of the steering device 1 according to the present embodiment, and is a diagram of the steering device 1 viewed from the rear in the vehicle front-rear direction.
As shown in FIG. 11, the configuration of the steering device 1 of the present embodiment is the same as that of the first embodiment described above except for the configuration of the vehicle including the steering device 1 and the configuration of the link member 4. Since the configuration of the vehicle including the steering device 1 and the configuration other than the link member 4 are the same as those in the first embodiment described above, detailed description thereof is omitted.

In the steering device 1 of the present embodiment, a vehicle including the steering device 1 is a vehicle including a wishbone type suspension.
In the steering device 1 of the present embodiment, the link member 4 to which the first gear 10 and the second gear 12 are attached is an upper link 60 that is disposed above the center of rotation of the steering wheel W in the vehicle vertical direction. In addition to the upper link 60, FIG. 11 shows a lower link 62 that is disposed below the center of rotation of the steering wheel W in the vehicle vertical direction and connects the wheel support member 2 and the vehicle body side member 20. .
Other configurations are the same as those of the first embodiment described above.

(Operation)
Next, the operation of the steering device 1 will be described with reference to FIG. In the following description, since the configuration other than the link member 4 is the same as that of the first embodiment described above, the operation of different parts will be mainly described.
Since the operation for changing the traveling direction of the vehicle during traveling of the vehicle including the steering device 1 is the same as that in the first embodiment described above, the description thereof is omitted.

Next, an operation when an external force is applied to the steered wheel W, such as when the steered wheel W comes into contact with a road surface projection during traveling of the vehicle including the steering device 1, will be described.
When an external force is applied to the steered wheel W, such as when the steered wheel W comes into contact with a road surface projection, a camber change or caster change may occur on the steered wheel W due to the external force.
On the other hand, in the steering apparatus 1 according to the present embodiment, the first gear 10 and the second gear 12 are attached to the upper link 60 in which the link member 4 is disposed above the rotation center of the steering wheel in the vehicle vertical direction.

For this reason, compared with the case where the first gear 10 and the second gear 12 are attached to the lower link 62, the periphery of the drive shaft or the like when the camber change or the caster change occurs in the steering wheel W and the wheel support member 2. Interference between the member and the steering device 1 can be suppressed.
Therefore, even when a camber change or a caster change occurs in the steering wheel W due to an external force applied to the steering wheel W during traveling of the vehicle, the interference between the peripheral member such as the drive shaft and the steering device 1 can be suppressed. It becomes possible.
In addition to the camber change and caster change described above, when an external force is applied to the steered wheels W, the external force causes the vehicle up-down direction between the link member 4 and the vehicle body side member 20 when viewed from the vehicle front-rear direction. Relative displacement may occur. Since the operation at that time is the same as that of the first embodiment described above, description thereof is omitted.

(Effect of the second embodiment)
(1) In the steering device of the present embodiment, the link member to which the first gear and the second gear are attached is an upper link that is disposed above the rotation center of the steering wheel in the vehicle vertical direction.
For this reason, compared with the case where the link member is a lower link that is disposed below the rotation center of the steering wheel in the vehicle vertical direction, the clearance that is formed below the rotation center of the steering wheel in the vehicle vertical direction is increased. It becomes possible.
As a result, when a caster change or camber change occurs in the steered wheel due to an external force applied to the steered wheel, such as when the steered wheel comes into contact with a road surface projection, the interference between the drive shaft and the steering device is suppressed. Is possible.

1 is a diagram illustrating a configuration of a steering device 1 according to a first embodiment of the present invention, and is a top view of the steering device 1. FIG. FIG. 2 is a view taken along line II in FIG. 1. FIG. 3 is an enlarged view of a range surrounded by a circle III in FIG. 2. It is the IV-IV sectional view taken on the line of FIG. It is the VV sectional view taken on the line of FIG. It is a figure which shows the steering apparatus 1 of a comparative example. It is a VII arrow directional view of FIG. It is a figure which shows the steering apparatus 1 of a modification. It is a figure which shows the steering apparatus 1 of a modification. It is a figure which shows the steering apparatus 1 of a modification. It is a figure which shows the structure of the steering apparatus 1 of 2nd embodiment of this invention, and is the figure which looked at the steering apparatus 1 from the vehicle front-back direction back.

Explanation of symbols

1 Steering device 2 Wheel support member 4 Link member (lower link, upper link)
6 Steering shaft 8 Steering means 10 First gear 12 Second gear 14 Steering force transmission portion 16 Shock absorber 18 Strut 20 Vehicle body side member 22 Bush 24 Shaft side gear 26 Pivot member 28 Outer member 30 Inner member 32 Rolling element 34 Concave part 36 Bearing member 38 Support shaft 40 Outer member side rolling element rolling groove 42 Outer member side protruding part 44 Hemisphere part 46 Inner member side rolling element rolling groove 48 Inner member side protruding part 50 Transmission shaft 52 Boot 54 Cage 56 Steering force transmission mechanism (outer member 28, inner member 30, rolling element 32)
58 Constraining link 60 Upper link 62 Lower link W Steering wheel B Vehicle body LF, LR Vehicle body side connection points (two vehicle body side connection points)
PP Pivot point T A straight line passing through the vehicle body side connection point LF and the vehicle body side connection point LR (a straight line passing through two vehicle body side connection points)
S1 Rotating shaft of first gear 10 S2 Rotating shaft of second gear 12 C Clearance formed between outer member side protruding portion 42 and inner member side protruding portion 48 D Diameter of rolling element 32

Claims (6)

A steering device for steering a steered wheel according to a steering operation of a driver,
A wheel support member that rotatably supports the steering wheel, one end portion is swingably connected to the vehicle body side member, and the other end portion is swingably connected to the steering wheel via a steering force transmission portion. A link member, a steering shaft extending in the vehicle width direction and rotatable about an axis, and a steering means for rotating the steering shaft in accordance with the steering operation,
The link member includes a first gear that converts rotation of the steering shaft into rotation about a vehicle vertical axis at a position outside the vehicle body side member of the link member in the vehicle width direction, and the first gear A second gear that rotates about the vehicle vertical axis by the rotation of
The steering device, wherein the steering force transmission unit includes a steering force transmission mechanism that rotates the wheel support member about a vehicle vertical axis by rotation of the second gear. One end of the link member is connected to the vehicle body side member at two vehicle body side connection points that are separated in the vehicle longitudinal direction,
The steering shaft and the steering means are connected so as to be rotatable at least about a vehicle longitudinal axis, and a connection point between the steering shaft and the steering means passes through the two vehicle body side connection points. The steering device according to claim 1, wherein the steering device is arranged on a straight line.   3. The steering device according to claim 1, wherein the steering shaft, the first gear, and the second gear are arranged at positions that overlap the link member when viewed from the front-rear direction of the vehicle.   The steering apparatus according to any one of claims 1 to 3, wherein the link member is an upper link that is disposed above the center of rotation of the steering wheel in a vehicle vertical direction. The steering force transmission unit includes an outer member having a hemispherical concave portion whose opening is directed upward in the vehicle vertical direction, an inner member having a hemispherical portion opposed to the concave portion, the concave portion, and the hemispherical portion. A plurality of rolling elements arranged between and
A plurality of outer member-side rolling element rolling grooves extending radially when viewed from the vehicle vertical direction are formed on the inner surface of the recess,
A plurality of inner member-side rolling element rolling grooves facing the outer member-side rolling element rolling groove are formed on the curved surface of the hemispherical portion,
The plurality of rolling elements are slidably loaded between the outer member-side rolling element rolling grooves and the inner member-side rolling element rolling grooves,
The minimum gap between the recess and the hemisphere is less than the diameter of the rolling element,
Connecting the outer surface of the recess to the second gear;
The steering device according to any one of claims 1 to 4, wherein a plane of the hemispherical portion is connected to the wheel support member. A steered wheel steering method for steering a steered wheel according to a driver's steering operation,
The rotation of the steering shaft according to the steering operation is converted into rotation around the vehicle vertical axis by the first gear,
By rotating the first gear, the second gear is rotated around the vehicle vertical axis,
By rotating the second gear, the second gear and a wheel support member that rotatably supports the steering wheel are connected to be swingable about a vehicle longitudinal axis and a vehicle width axis. A steered wheel steering method, wherein a wheel support member is rotated about a vehicle vertical axis.

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