JP4111073B2 - Vehicle steering system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle steering apparatus that steers a wheel by using a power source in a vehicle and, more particularly, to an improved structure for imparting a force to the wheel to steer it. It is.
[0002]
[Prior art]
2. Description of the Related Art A vehicle steering apparatus that steers a wheel by using a power source in a vehicle to steer the vehicle is already known (see, for example, Patent Document 1).
[0003]
The vehicle steering apparatus described in Patent Document 1 includes (a) a rack shaft that is linearly moved to steer wheels, (b) a support shaft that intersects with the rack shaft, and (c) a rack shaft. A rotating body parallel to the rotating body; (d) an electric motor as a power source for rotating the support shaft; (e) a bevel gear pair that transmits the rotational motion of the supporting shaft to the rotating body; and (f) rotation of the rotating body. And a ball screw for converting the movement into a linear movement of the rack shaft.
[0004]
[Patent Document 1]
JP 2002-27497A
[0005]
[Problems to be solved by the invention]
This type of vehicle steering apparatus is, for example, a type that is mechanically insulated from a steering operation member operated by a driver for steering and is electrically connected to the steering operation member, so-called steer-by-steer. -It is possible to adopt a wire system. When this method is adopted, in principle, the wheels are steered using only a power source (for example, an electric motor or a pressure source).
[0006]
This type of vehicle steering apparatus is further mechanically linked to the steering operation member at all times, so that when the steering operation member is operated, the operation force is transmitted to the wheels as a steering force, and In order to assist the operation, it is also possible to adopt a power steering system in which power from a power source is added to the wheels as a steering force.
[0007]
That is, in this power steering system, a system that transmits the manual turning force by the driver to the wheels and a system that transmits the assist turning force by the power source to the wheels coexist.
[0008]
When this power steering system is adopted, even if the power source is lost, manual steering by the driver is ensured. On the other hand, even when the steer-by-wire method described above is employed, it is desirable to employ a backup mechanism so that manual steering by the driver is ensured even if the power source is lost.
[0009]
For this reason, even when the steer-by-wire method is adopted, a system that transmits the steering force from the power source to the wheels when the power source is normal and a manual steering force by the driver when the power source is abnormal Should be co-located with the transmission system.
[0010]
If it does so, it is desirable to coexist the system which transmits steering power by a power source to a wheel, and the system which transmits manual steering power by a driver to a wheel, even if it is a case where any system is adopted.
[0011]
However, if this request is to be realized, the structure of the vehicle steering device is likely to be complicated. This problem is particularly serious when the steer-by-wire method is adopted. When adopting the power steering method, it is possible to add the manual turning force and the turning force by the power source to the same wheel in series with each other, and add them to the same wheel in an independent system. This is because it is indispensable when the steer-byer wire method is adopted.
[0012]
Against the background described above, the present invention is a vehicle steering apparatus that steers a wheel by using a power source in the vehicle to steer the vehicle, and has a structure that applies a force to the wheel to steer it. It has been made with the task of facilitating downsizing.
[0013]
[Means for Solving the Problems and Effects of the Invention]
  The following aspects are obtained by the present invention. Each mode is divided into sections, each section is numbered, and is described in a form that cites other section numbers as necessary. This is to facilitate understanding of some of the technical features described herein and some of the combinations thereof. The technical features and combinations of the technical features described herein are It should not be construed as limited.
(1) A vehicle steering apparatus that steers a vehicle by turning a wheel using a power source in the vehicle,
  A linear motion member that is linearly moved to steer the wheels;
  A first axis of rotation intersecting the linear motion member;
  Of the first axis of rotationBy steering wheel operation force or wire operation forceA first motion conversion mechanism that converts rotational motion into linear motion of the linear motion member;
  A first power source arranged to be coaxial with the first rotating shaft and to overlap in a diametrical direction for linearly moving the linear motion member;
  A second axis of rotation parallel to the linear motion member;
  SaidOf the second axis of rotationBy one of the first power source or the second power source different from the first power source and the first power sourceA second motion conversion mechanism that converts rotational motion into linear motion of the linear motion member;
  A vehicle steering apparatus including:
[0014]
In this device, the turning force of the wheels passes through the first transmission path through the first rotating shaft, the first motion conversion mechanism, and the linear motion member, the first power source, and the linear motion member. It is generated using the second transmission path.
[0015]
Here, in the second transmission path, a mode in which the first power source and the linear motion member are linked with each other via the second rotation shaft and the second motion conversion mechanism, It is possible to adopt a mode in which they are linked with each other via a motion conversion mechanism. In any case, as a result, the first power source causes the linear motion member to linearly move regardless of the route to be used.
[0016]
In the apparatus according to this aspect, the first rotating shaft and the first power source are coaxial with each other and diametrically with respect to each other even though the first and second transmission paths exist. Are arranged to overlap. That is, in order to arrange the first power source, it is not indispensable to set another rotation axis that is not coaxial with the first rotation shaft in the vehicle steering apparatus.
[0017]
Therefore, according to this apparatus, when the first rotating shaft and the first power source are not arranged coaxially with each other, and arranged coaxially with each other, they overlap with each other in the diametrical direction. Compared to the case where the wheels are not arranged, the structure for imparting the steering force to the wheels can be made compact.
[0018]
The “first power source” in this section includes, for example, a motor that is coaxial with the first rotating shaft or a rotating member that is coaxial with the first rotating shaft and is rotated by pressure. It is possible to configure the pressure source as a main component.
[0019]
Furthermore, the apparatus according to this section can employ the above-described steer-by-wire system or the above-described power steering system.
(2) The first power source includes a rotating member that is coaxial with the first rotating shaft and is arranged so as to overlap with the first rotating shaft in the diameter direction, and rotates the rotating member. The vehicle steering device according to (1).
[0020]
According to this apparatus, it becomes easy to arrange the first rotating shaft and the rotating member in the first power source in a compact manner.
(3) The vehicle steering apparatus according to (2), wherein the rotating member is hollow, and the first rotating shaft extends coaxially through the rotating member and extends to the linear motion member.
[0021]
According to this apparatus, it becomes easy to arrange the first rotating shaft and the rotating member in the item (2) in a compact manner.
(4) The vehicle steering apparatus according to (3), wherein the first rotating shaft and the rotating member are supported so as to be relatively rotatable.
[0022]
According to this device, it is possible to cause the wheel turning force transmission path that has passed through the first rotation shaft and the wheel turning force transmission path that has passed through the rotating member to function independently of each other as transmission paths.
(5) The vehicle steering apparatus according to any one of (2) to (4), further including a motion transmission mechanism that transmits a rotational motion of the rotating member to the second rotating shaft.
[0023]
According to this apparatus, the turning force by the first power source is transmitted to the linear motion member via the rotation member, the motion transmission mechanism, the second rotation shaft, and the second motion conversion mechanism.
[0024]
Here, for example, when the transmission efficiency in the direction from the wheel to the first power source, that is, the reverse efficiency is designed to be low with respect to the motion transmission mechanism, the wheel is switched against the road surface input to the wheel. It is not indispensable to actively provide a detent for maintaining the rudder angle.
(6) The motion transmission mechanism includes a hypoid gear configured by meshing a pair of bevel gears that transmit motion between staggered shafts, and one of the pair of bevel gears is coaxial with the rotating member. The vehicle steering device according to (5), wherein the vehicle is rotated integrally, and the other is rotated integrally coaxially with the second rotation shaft.
[0025]
According to this device, it is easy to make the structure for transmitting motion between the two staggered shafts of the rotating member and the second rotating shaft compact.
(7) The vehicle steering apparatus according to any one of (1) to (6), wherein a center line of the first rotation shaft is three-dimensionally intersected with a center line of the linear motion member.
[0026]
  According to this apparatus, it is possible to cross the linear motion member without locally offsetting the first rotation axis.
(8) Furthermore,The second power source isIn order to rotate the second rotating shaft, it is arranged coaxially with the second rotating shaft.Is a thing(1) The steering apparatus for vehicles according to any one of (7).
[0027]
According to this apparatus, the steering force is applied to the wheel by using both the first power source and the second power source according to any one of the items (1) to (7). It becomes possible.
[0028]
  These first and second power sources are redundant for the same purpose so as to ensure that the power source is used to impart a steering force unless both of them fail. It is possible to make it work. That is, the first and second power sources can cooperate with each other to realize a redundant design.
(9) The second power source includes a plurality of rotating units that rotate the second rotating shaft independently of each other.Said second rotating shaftThe vehicle steering apparatus according to item (8), which is included coaxially with the vehicle.
[0029]
According to this apparatus, by configuring the second power source to include a plurality of rotating units, a redundant design can be realized by the second power source alone.
(10) The vehicle includes a steering operation member operated by a driver of the vehicle, and the vehicle steering apparatus further selects at least an operation force of the steering operation member as a rotation force on the first rotation shaft. The vehicle steering device according to any one of (1) to (9), including an operation force transmission device that transmits the operation force.
[0030]
According to this apparatus, the state which steers a wheel with the manual operation force by a driver | operator is ensured. The operating force transmission device in this device is designed so that the manual operating force can be transmitted to the wheels at all times when the vehicle steering device adopts the power steering system described above, whereas the steering-by device described above. -When adopting the wire system, it is designed to transmit the manual operation force to the wheels when the power source should be lost.
(11) The first power source includes a hollow rotating member that is coaxially penetrated by the first rotating shaft, and the rotating member is supported by the first rotating shaft. The vehicle steering system according to any one of (1) to (10), wherein one rotation shaft extends through the linear motion member and is rotatably supported on both sides of the linear motion member. apparatus.
[0031]
According to this apparatus, since the first rotating shaft is rotatably supported on both sides of the intersection of the first rotating shaft and the linear motion member, that is, the point of action of the force, it is compared with the case where it is supported only on one side. In addition, the support rigidity of the first rotating shaft is improved, and it is easy to avoid the center line of the first rotating shaft from being shifted unexpectedly during its operation. Furthermore, it is easy to avoid a decrease in transmission efficiency and abnormal noise caused by such an unscheduled shift.
(12) The vehicle steering apparatus according to any one of (1) to (11), further including an absolute angle sensor that detects an absolute rotation angle of the first rotation shaft.
[0032]
In general, the technique for detecting the absolute rotation angle of a certain rotating shaft is more advanced when the rotating shaft rotates twice or more than when it does not rotate more than one rotation. Therefore, for example, a speed reduction mechanism that reduces the rotational speed of the rotation shaft may be added to the absolute angle sensor. Then, there arises a problem that the structure for detecting the absolute rotation angle is increased in size and a problem that the apparatus cost is increased.
[0033]
On the other hand, in the apparatus according to this section, the first rotation shaft whose absolute rotation angle is to be detected does not go through the series structure of the motion transmission mechanism and the second motion conversion mechanism, It is linked to a linear motion member via a motion conversion mechanism. In other words, the first rotating shaft is generally linked to the linear motion member without going through a structure in which a mechanism having a deceleration function is serialized.
[0034]
Therefore, according to this device, the change amount of the absolute rotation angle of the first rotation shaft corresponding to the change of the turning angle of the wheel by the same amount is the same as that of the motion transmission mechanism and the second rotation shaft. Compared to the case where the linear motion member is linked via a series structure with the motion conversion mechanism, the number of the motions can be reduced.
[0035]
Therefore, according to this apparatus, the structure of the absolute angle sensor that detects the absolute angle of the first rotating shaft can be made compact and the cost can be easily reduced.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, some of more specific embodiments of the present invention will be described in detail with reference to the drawings.
[0037]
FIG. 1 systematically shows a steering apparatus for a vehicle according to the first embodiment of the present invention in a sectional view. This steering device electrically steers left and right front wheels as steered wheels in a steer-by-wire system in a vehicle having left and right front wheels (not shown) and left and right rear wheels (not shown). .
[0038]
As shown in FIG. 1, this vehicle includes a steering wheel 10 (this is an example of the steering operation member) that is rotated by a driver to steer left and right steered wheels. On the other hand, the steering device is configured to include an operation control unit 20 and a steering control unit 22.
[0039]
As shown in FIG. 1, the operation control unit 20 includes a steering shaft 30 that is coaxially connected to the steering wheel 10. On the other hand, as shown in FIG. 1, the steering control unit 22 is a rack bar (also called a rack shaft) that extends in the left-right direction and is moved in the length direction of the vehicle. This is an example of the linear motion member. ) 32, and the left and right steered wheels are steered by the rack bar 32.
[0040]
In this steering apparatus, as long as it is normal, the steering wheel 10 and the steering control unit 22 are mechanically insulated from each other. Therefore, the operation control unit 20 artificially applies a steering reaction force to the steering wheel 10 in order to reproduce an operation feeling equivalent to that of a conventional manual steering device.
[0041]
Specifically, as shown in FIG. 1, the operation control unit 20 is provided with a steering shaft motor 40. Although not shown, the steering shaft motor 40 is configured to include a rotor and a stator. This configuration is common to the following other motors.
[0042]
On the other hand, in the steering control unit 22, as shown in FIG. 1, a pinion 54 is engaged with a rack 52 formed on the rack bar 32. That is, in this steering apparatus, the rack 52 and the pinion 54 cooperate with each other to form a rack-and-pinion-type motion conversion mechanism 55 (this is an example of the first motion conversion mechanism). It is. A pinion shaft 56 extending from the pinion 54 (this is an example of the first rotating shaft) is three-dimensionally intersected with the rack bar 32 at a right angle.
[0043]
In order to impart linear motion to the rack bar 32, the steering control unit 22 includes first and second rack shaft motors 58 and 59 (hereinafter simply referred to as “motors A and B”) and their rotational motion. Is provided with a ball screw 60 (which is an example of the second motion conversion mechanism) as a motion conversion mechanism for converting the motion to the linear motion of the rack bar 32.
[0044]
The ball screw 60 is generally designed to have a higher reduction ratio (higher reduction effect) than the rack-and-pinion type motion conversion mechanism 55. Therefore, the ball screw 60 is higher than the motion conversion mechanism 55 in terms of reverse efficiency, and therefore effectively used as a detent that prevents rotation of the steered wheels against the road surface input to the steered wheels. Is generally possible.
[0045]
In addition, the reason why the two rack shaft motors 58 and 59 are used for the same rack bar 32 is to increase the redundancy of the electrical drive system of the rack bar 32 and improve the fault tolerance. is there. This type of redundant design is also found elsewhere in this embodiment.
[0046]
The motors A and B are provided with a cylindrical housing 61 common to them. The rack bar 32 is coaxially penetrated through the housing 61, and both end portions of the rack bar 32 are exposed from both end portions of the housing 61. A rack 52 is formed at one of both end portions of the rack bar 32, and a pinion 54 is engaged with the rack 52. A ball screw 60 is also accommodated in the housing 61. The ball screw 60 is configured by screwing a female screw 62 and a male screw 64.
[0047]
The female screw 62 is supported so as to be rotatable and immovable in the axial direction. The female screw 62 functions as a rotor 70 common to the motors A and B. As a result, the female screw 62 is rotated by the motors A and B.
[0048]
A magnet 72 is attached to the outer surface of the rotor 70, and the rotor 70 faces the stators 74 of the motor A and the motor B in the magnet 72. The rotor 70 is supported by the housing 61 through a suitable number of bearings 78 so as to be relatively rotatable.
[0049]
On the other hand, the male screw 64 is supported so as not to rotate but to move in the axial direction. The male screw 64 is linearly displaced in accordance with the rotation of the female screw 62, thereby displacing the rack bar 32 in the length direction thereof. This male screw 64 is also referred to as a rack shaft.
[0050]
In order to detect the rotation angle of the same rotor 70, two rotation angle sensors 82, 82 are provided. Each of the rotation angle sensors 82 and 82 is a resolver, and includes a resolver rotor 84 that rotates together with the rotor 70 and a resolver stator 86 that is fixed to the housing 61.
[0051]
As shown in FIG. 1, the steering control unit 22 further includes a coaxial motor 90 (hereinafter simply referred to as “motor C”) coaxially with the pinion shaft 56. The motor C is provided to apply a rotational force to the rotor 70. The motor C is provided to be redundant with respect to the motors A and B as a power source for rotating the rotor 70. Thereby, the fault tolerance of this steering device is improved.
[0052]
The motor C includes a cylindrical housing 94. The pinion shaft 56 is penetrated coaxially through the housing 94, and both end portions of the pinion shaft 56 are exposed from both end portions of the housing 94.
[0053]
The motor C includes a hollow rotor 100 (which is an example of the rotating member) having a magnet 98 mounted on the outer peripheral side and a stator 102 disposed on the outer peripheral side thereof. In the present embodiment, the rotor 100 has a hollow structure, and the pinion shaft 56 is coaxially penetrated through the rotor 100. The pinion shaft 56 is supported by the rotor 100 via an appropriate number of bearings 104 so as to be relatively rotatable, and the rotor 100 is supported by the housing 94 via an appropriate number of bearings 106. One end portion of the pinion shaft 56 protrudes from one end portion of the housing 94 and passes through the rack bar 32, but is supported via the bearing 104 as described above on one side of the rack bar 32. In addition, the other side is also supported via a bearing 108. That is, the pinion shaft 56 is rotatably supported on both sides of the rack bar 32 via the bearings 104 and 108, respectively.
[0054]
As is apparent from the above description, in the present embodiment, the pinion shaft 56 and the motor C are arranged coaxially with each other and overlapping each other in the diameter direction thereof. Further, the housing 94 is provided with a rotation angle sensor 112. The rotation angle sensor 112 is also a resolver, and includes a resolver rotor 114 that rotates together with the rotor 100 and a resolver stator 116 that is fixed to the housing 94.
[0055]
As shown in FIG. 1, the steering control unit 22 further includes a motion transmission mechanism 120 for transmitting the rotational motion of the rotor 100 to the rotor 70 having an axis that is different from the axis of the rotor 100. In this embodiment, the motion transmission mechanism 120 is configured as a hypoid gear. The hypoid gear is composed of a pair of bevel gears 122 and 124 that transmit motion between staggered axes. One bevel gear 122 is rotated integrally with the rotor 100, and the other bevel gear 124 is rotated coaxially with the rotor 70.
[0056]
As shown in FIG. 2, the pair of bevel gears 122 and 124 have their axes intersecting with each other. Therefore, in this embodiment, the pinion 54 is meshed with the rack 52 formed on the side surface eccentric from the center line of the rack bar 32 without locally offsetting the rack bar 32.
[0057]
As shown in FIG. 1, the pinion shaft 56 is equipped with an absolute angle sensor 130 that detects the absolute angle thereof.
[0058]
As shown in FIG. 1, the steering device mechanically steers the left and right front wheels by operating the steering wheel 10 when the electrical system of the steering control unit 22 breaks down. Therefore, a backup control unit 140 is provided.
[0059]
As shown in FIG. 1, the backup control unit 140 includes a pulley 142 engaged with the steering shaft 30 and a pulley 144 engaged with the pinion shaft 56. In this embodiment, both pulleys 142 and 144 are coaxially fixed to the corresponding ones of the steering shaft 30 and the pinion shaft 56. A wire 146 is wound around the two pulleys 142 and 144.
[0060]
However, a clutch 150 is provided between the steering shaft 30 and the pinion shaft 56, specifically, in the middle of the wire 146. The clutch 150 always mechanically insulates the two from each other. However, when the steering device is abnormal, the two are mechanically linked to each other.
[0061]
As is clear from the above description, in this embodiment, the two pulleys 142, the pulley 144, the wire 146, and the clutch 150 together constitute the operating force transmission device.
[0062]
As shown in FIG. 1, the operation control unit 20 is provided with an absolute angle sensor 152 that detects a steering angle that is a rotation angle of the steering wheel 10 as an absolute angle.
[0063]
The structure of this steering apparatus has been described above. Next, the operation thereof will be described.
[0064]
When the electrical system of the steering apparatus is normal, the clutch 150 is in a released state, and therefore the operating force of the steering wheel 10 is not transmitted to the pinion shaft 56. Instead, the motor A to C that is not abnormal is driven based on the operating state of the steering wheel 10.
[0065]
When the motors A and B are driven, the rotational motion of the rotor 70 is converted into linear motion by the ball screw 60 and transmitted to the rack bar 32. As a result, the rack bar 32 is linearly displaced, and based on this, the steered wheels are steered.
[0066]
On the other hand, when the motor C is driven, the rotational motion of the rotor 100 is transmitted to the rotor 70 via the motion transmission mechanism 120. Thereafter, similarly to the above case, the rack bar 32 is linearly displaced and the steered wheels are steered.
[0067]
On the other hand, when the electric system of the steering device is abnormal, the clutch 150 is in a connected state, and therefore, the operating force of the steering wheel 10 is transmitted to the pinion shaft 56 through the pulley 142, the wire 146, and the pulley 144. . When the pinion shaft 56 is rotated by the operating force, the rotational motion is converted into a linear motion of the rack bar 32 by a rack-and-pinion motion conversion mechanism 55. Thereafter, the steered wheels are steered based on the linear displacement of the rack bar 32 in the same manner as described above.
[0068]
Next, a second embodiment of the present invention will be described. However, the present embodiment differs from the first embodiment only in the relative positional relationship between the pinion shaft 56 and the rack bar 32, the shape of the rack bar 32, and the type of the motion transmission mechanism 120, and the other elements are common. For this reason, common elements will be referred to using the same names or symbols, and detailed description thereof will be omitted, and only different elements will be described in detail.
[0069]
In the first embodiment, as shown in FIG. 2, the center line of the pinion shaft 56 and the center line of the rack bar 32 are three-dimensionally crossed with each other, and therefore a hypoid gear is employed as the motion transmission mechanism 120. The local offset of the rack bar 32 is omitted.
[0070]
In contrast, in the present embodiment, as shown in FIGS. 3 to 5, the center line of the pinion shaft 56 and the center line of the rack bar 32 are orthogonal to each other. Therefore, the motion transmission mechanism 170 is mainly composed of a pair of bevel gears 172 and 174 that transmit motion between these orthogonal axes.
[0071]
In the present embodiment, as shown in FIG. 4, the rack bar 32 is locally offset, and a rack 52 is formed at the offset portion 176. As a result, the rack-and-pinion type motion conversion mechanism 55 is realized even though the center line of the rack bar 32 and the center line of the pinion shaft 56 are orthogonal to each other.
[0072]
Next, a third embodiment of the present invention will be described. However, the present embodiment is different from the first embodiment only in the steering control method and the driving method of the rack bar 32, and is common to the other elements, so the same name or symbol is used for the common elements. Therefore, the detailed description will be omitted by citing and only different elements will be described in detail.
[0073]
In the first embodiment, as described above, the steer-by-wire method is adopted as the steering control method, but in this embodiment, an electric steering method that is an example of a power steering method is adopted. .
[0074]
Specifically, as shown in FIG. 6, the steering shaft 30 and the pinion shaft 56 are always mechanically linked to each other by a joint 190. Therefore, in the present embodiment, the operation force of the steering wheel 10 is transmitted to the pinion shaft 56 and the rack bar 32 regardless of whether or not the electric system of the steering device is abnormal, and as a result, the wheels are steered by the manual operation force. Be made.
[0075]
Further, in the present embodiment, a torque sensor 192 is provided to detect the steering torque applied to the steering wheel 10 by the driver.
[0076]
In the first embodiment, as shown in FIG. 1, the rotor 70 is rotated not only by the motors A and B but also by the motor C. However, in the present embodiment, the rotor 70 is rotated only by the motor C. It is supposed to be.
[0077]
In the present embodiment, when the electrical system is normal, the motor C is driven to electrically assist the operating force of the steering wheel 10. Specifically, the rotor 100 and the bevel gear 122 are rotated by the motor C, and the rotational motion thereof is transmitted to the bevel-shaped gear 124 and the rotor 70 by the motion transmission mechanism 170, and the rotational motion of the rotor 70 is the ball screw 60. Is converted into a linear motion of the rack bar 32. As a result, the wheels are steered.
[0078]
As described above, some of the embodiments of the present invention have been described in detail with reference to the drawings. However, these are only examples, and include the aspects described in the section of [Means for Solving the Problems and Effects of the Invention]. As described above, the present invention can be implemented in other forms in which various modifications and improvements are made based on the knowledge of those skilled in the art.
[Brief description of the drawings]
FIG. 1 is a front sectional view systematically showing a vehicle steering apparatus according to a first embodiment of the present invention.
2 is a partial side cross-sectional view showing a motion transmission mechanism 120 in FIG. 1. FIG.
FIG. 3 is a front cross-sectional view showing a main part of a vehicle steering apparatus according to a second embodiment of the present invention.
4 is a plan sectional view showing a main part of the vehicle steering system of FIG. 3; FIG.
5 is a side cross-sectional view showing a main part of the vehicle steering device of FIG. 3; FIG.
FIG. 6 is a front sectional view showing a vehicle steering apparatus according to a third embodiment of the present invention.
[Explanation of symbols]
32 rack bars
52 racks
54 Pinion
55 Motion conversion mechanism
56 pinion shaft
58 Motor A
59 Motor B
60 Ball screw
70 rotor
90 Coaxial motor
100 rotor
120,170 Motion transmission mechanism
130 Absolute angle sensor
140 Backup control unit
142,144 pulley
146 wire
150 clutch

Claims (9)

A vehicle steering apparatus that steers a wheel by using a power source in a vehicle to steer the vehicle,
A linear motion member that is linearly moved to steer the wheels;
A first axis of rotation intersecting the linear motion member;
A first motion conversion mechanism that converts a rotational motion by an operation force of the steering wheel of the first rotation shaft or an operation force through a wire into a linear motion of the linear motion member;
A first power source arranged to be coaxial with the first rotating shaft and to overlap in a diametrical direction for linearly moving the linear motion member;
A second axis of rotation parallel to the linear motion member;
It said second of said first power source of the rotary shaft, or a straight line of the first power source and the linear motion member rotational movement by one of the first power source is different from the second power source A second motion conversion mechanism that converts motion,
A vehicle steering apparatus including:   The first power source includes a rotating member that is coaxial with the first rotating shaft and is arranged to overlap with the first rotating shaft in a diametrical direction, and rotates the rotating member. The vehicle steering device according to claim 1.   The vehicle steering apparatus according to claim 2, wherein the rotating member is hollow, and the first rotating shaft extends coaxially through the rotating member and extends to the linear motion member.   The vehicle steering apparatus according to claim 2, further comprising a motion transmission mechanism that transmits a rotational motion of the rotating member to the second rotating shaft. It said second power source, said to rotate the second rotary shaft, the vehicle steering apparatus according to any one of the second rotary shaft and the claims 1 to 4 in which is arranged coaxially . The vehicle steering apparatus according to claim 5, wherein the second power source includes a plurality of rotating portions that rotate the second rotating shaft independently of each other coaxially with the second rotating shaft .   The vehicle includes a steering operation member operated by a driver of the vehicle, and the vehicle steering device further transmits at least selectively the operation force of the steering operation member to the first rotation shaft as a rotation force. The vehicle steering device according to any one of claims 1 to 6, further comprising an operating force transmission device.   The first power source includes a hollow rotating member that is coaxially penetrated by the first rotating shaft, and the rotating member is supported by the first rotating shaft. The vehicle steering apparatus according to claim 1, wherein a shaft extends through the linear motion member and is rotatably supported on both sides of the linear motion member.   The vehicle steering apparatus according to claim 1, further comprising an absolute angle sensor that detects an absolute rotation angle of the first rotation shaft.

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