JP2016060245A - Vehicular steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular steering device that can be operated more accurately.SOLUTION: A vehicular steering device (10) is mounted with a planetary gear mechanism (140). A planetary gear (150) of the planetary gear mechanism (140) is constituted of: a gear shaft (151) fixed to a planetary carrier (); a thrust bearing (152) provided on an outer periphery of the gear shaft (151); a needle-shaped roller bearing (153) provided on an upper face part of the thrust bearing (152) and on the outer periphery of the gear shaft (151); a gear main body (154) that is provided on the outer periphery of the needle-shaped roller bearing (153) and on the upper face part of the thrust bearing (152), on a peripheral edge of which are formed a plurality of teeth; and a washer (155) provided on the upper face part of the gear main body (154).SELECTED DRAWING: Figure 5

Description

  The present invention relates to a so-called steer-by-wire (abbreviated as “SBW”) vehicle steering apparatus.

  The steer-by-wire vehicle steering device is configured such that, during normal driving, the steering wheel and the rack shaft that steers the wheel are mechanically separated. In such a vehicle steering apparatus, the steering wheel is mechanically connected to the rack shaft in an emergency. As a conventional technique related to a vehicle steering apparatus equipped with a clutch mechanism for switching between disconnection and connection, there is a technique disclosed in Patent Document 1.

  A vehicle steering apparatus as shown in Patent Document 1 is formed integrally with an input shaft connected to a steering wheel, a planetary gear mechanism connected to the input shaft, and the planetary gear mechanism. And a pinion shaft having one end connected to the planetary gear mechanism and the clutch mechanism and the other end connected to the rack shaft.

  The clutch mechanism has a gear-like lock wheel that can rotate integrally with the sun gear of the planetary gear mechanism, two lock arms that are swingably mounted near the lock wheel, and each of these lock arms. And a solenoid having a contactable rod and capable of regulating the swing of the lock arm.

  The planetary gear mechanism is configured such that a sun gear is arranged at the center, a planetary gear that can revolve while rotating around the periphery of the sun gear is supported by a planetary carrier, and a ring gear is arranged at the periphery of the orbit drawn when the planetary gear revolves. ing. The ring gear is connected to the input shaft, and the planetary carrier is connected to the pinion shaft.

  During normal operation, the lock wheel is in a rotatable state. As a result, the sun gear is also rotatable. The ring gear connected to the input shaft is also rotatable. Since both the sun gear and the ring gear can rotate, even if a steering torque is generated on the input shaft, the planetary gear only rotates and does not revolve. That is, the planetary gear is idled and the steering torque is not transmitted to the pinion shaft. In this case, the turning power provided according to the steering torque is generated by the turning actuator provided on the rack shaft to perform the turning.

  On the other hand, in an emergency, by stopping energization to the solenoid, the lock arm swings by the urging force of the spring. One of the swinging lock arms comes into contact with the teeth of the lock wheel to restrict the rotation of the lock wheel. Thereby, rotation of the sun gear formed integrally with the lock wheel is also restricted. When the steering torque is generated on the input shaft and the ring gear rotates, the planetary gear revolves while rotating around the periphery of the sun gear. As a result, the planetary carrier rotates and the pinion shaft also rotates. That is, the steering torque of the input shaft is transmitted to the pinion shaft. In this case, the steering torque generated on the input shaft is transmitted to the rack shaft, and the steering can be performed.

  When the planetary gear rotates as disclosed in Patent Literature 1, frictional resistance inevitably occurs between the components constituting the planetary gear. For example, even when the sun gear is idling, the planetary gear may slightly revolve due to the influence of friction. As a result, the planetary carrier rotates and the pinion shaft also rotates. In other words, when it is desired to prevent the pinion shaft from rotating, the pinion shaft may be slightly rotated. It is desired to suppress the rotation of the pinion shaft against the intention and operate the vehicle steering device more accurately.

JP 2008-189077 A

  An object of the present invention is to provide a vehicle steering apparatus that can be operated more accurately.

According to the first aspect of the present invention, the steering wheel, the input shaft connected to the steering wheel, the planetary gear mechanism connected to the input shaft, and the clutch mechanism connected to the planetary gear mechanism. A pinion shaft connected to the input shaft via the planetary gear mechanism and the clutch mechanism, a rack shaft connected to the pinion shaft via a rack and pinion mechanism, and the rack shaft directly or A vehicle steering apparatus having a steering actuator that is indirectly connected and transmits a power for steering according to a steering amount of the steering wheel to the rack shaft;
The planetary gear mechanism has a planetary carrier that supports a planetary gear and is connected to the pinion shaft;
The planetary gear is
A gear shaft fixed to the planetary carrier;
A thrust bearing provided on the outer periphery of the gear shaft;
A needle roller bearing provided on the upper surface of the thrust bearing and on the outer periphery of the gear shaft;
A gear body provided with an outer periphery of the needle roller bearing and an upper surface portion of the thrust bearing, and a plurality of teeth formed on the periphery;
There is provided a vehicle steering apparatus comprising a washer provided on an upper surface portion of the gear body.

  In the invention according to claim 1, the planetary gear includes a gear shaft fixed to the planetary carrier, a thrust bearing provided on the outer periphery of the gear shaft, an upper surface portion of the thrust bearing, and an outer periphery of the gear shaft. A needle roller bearing provided, a gear body provided on the outer periphery of the needle roller bearing and on the upper surface portion of the thrust bearing and having a plurality of teeth formed on the periphery thereof, and provided on the upper surface portion of the gear body It consists of a washer.

  By providing the thrust bearing, the needle roller bearing, and the washer, the frictional resistance generated between the gear body and the gear shaft or between the gear body and each part of the planetary carrier can be reduced. As a result, unintentional rotation of the pinion shaft can be suppressed, and the vehicle steering device can be operated more accurately. It is particularly effective to take measures against friction of a planetary gear having a high rotational speed.

1 is a schematic diagram of a vehicle steering apparatus according to an embodiment of the present invention. It is sectional drawing of the principal part of the clutch mechanism and planetary gear mechanism which were shown by FIG. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. It is the figure which expanded the planetary gear shown by FIG. FIG. 3 is a schematic diagram of a clutch mechanism and a planetary gear mechanism shown in FIG. 2. It is a figure explaining an effect | action when the clutch mechanism shown by FIG. 3 exists in a fastening state. It is a figure explaining the effect | action of the planetary gear mechanism in case the clutch mechanism shown by FIG. 5 exists in a fastening state.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the description, left and right refer to the left and right based on the vehicle occupant, and front and rear refer to the front and rear based on the traveling direction of the vehicle.
<Example>

  A vehicle steering apparatus according to an embodiment will be described with reference to the drawings.

  As shown in FIG. 1, in the vehicle steering apparatus 10, the steering mechanism 30 is mechanically separated from the steering wheel 21 in a normal state, and the steering actuator 38 is operated according to the steering amount of the steering wheel 21. A so-called steer-by-wire system in which steering power is generated, transmitted to the steering mechanism 30, and the left and right steering wheels 35, 35 are steered by the steering mechanism 30. Abbreviation “SBW”). Hereinafter, the vehicle steering apparatus 10 will be described in detail.

  A steering mechanism 20 of the vehicle steering apparatus 10 includes a steering wheel 21 gripped by a driver, an input shaft 22 connected to the steering wheel 21, and an input shaft 22 that is disposed to face the input shaft 22 and is generated on the input shaft 22. A steering torque sensor 23 that detects the steering torque, a steering angle sensor 24 that is disposed opposite to the input shaft 22 and detects the steering angle of the steering wheel 21, and a reaction that applies a steering reaction force (reaction torque) to the steering wheel 21. It comprises a force transmission mechanism 25 and a motor rotation angle sensor 27 that detects the rotation angle of the reaction force motor 26 of the reaction force transmission mechanism 25.

  The steering angle of the steering wheel 21 is detected using a resolver of the reaction force motor 26 in addition to the steering angle sensor 24. The steering angle sensor 24 is an absolute angle sensor. The resolver of the reaction force motor 26 is a relative angle sensor with higher accuracy than the steering angle sensor 24.

  The steering mechanism 30 is connected to the lower end portion of the input shaft 22 via a planetary gear mechanism 140 and a clutch mechanism 80, and is connected to the pinion shaft 31 via a rack and pinion mechanism 33. A rack shaft 34, tie rods 36 and 36 and knuckles 37 and 37 that connect steered wheels 35 and 35 (for example, front wheels) to both ends of the rack shaft 34, and a steering shaft that adds steering power to the rack shaft 34 It comprises an actuator 38 and a pinion shaft rotation angle sensor 41 provided opposite to the pinion shaft 31 and detecting the rotation angle of the pinion shaft 31.

  The input shaft 22 includes a plurality of shaft members 22a connected by universal joints 22b and 22b.

  The reaction force transmission mechanism 25 is a mechanism that transmits reaction force torque generated by the reaction force motor 26 to the input shaft 22 via the worm gear mechanism 28. The worm gear mechanism 28 includes a worm 28 a provided on the motor shaft 26 a of the reaction force motor 26, and a worm wheel 28 b that meshes with the worm 28 a and is provided on the input shaft 22. An electric motor can be used as the reaction force motor 26.

  The rack and pinion mechanism 33 provided in the steering mechanism 30 includes a pinion 43 formed integrally with the pinion shaft 31, and a rack 44 meshed with the pinion 43 and formed integrally with the rack shaft 34. It consists of.

  The steering actuator 38 includes a steering power motor 45 that generates steering power and a steering power transmission mechanism 46 that transmits the steering power to the rack shaft 34. An electric motor can be used as the steering power motor 45.

  The position of the rack shaft 34 is detected by using the pinion shaft rotation angle sensor 41 and the resolver of the turning power motor 45 as well. The pinion shaft rotation angle sensor 41 is an absolute angle sensor. The resolver of the turning power motor 45 is a relative angle sensor with higher accuracy than the pinion shaft rotation angle sensor 41. At the time of activation, the middle point is written using the pinion shaft rotation angle sensor 41. Normally, control is performed using the resolver detection value.

  The steered power transmission mechanism 46 includes a drive pulley 47 attached to the rotating shaft of the steered power motor 45, a driven pulley 48 attached to the rack shaft 34, and the drive pulley 47 and the driven pulley 48. And a belt 49 which is stretched over.

  The clutch mechanism 80 is a mechanism for switching between a fastening state in which the input shaft 22 and the pinion shaft 31 are mechanically connected and a release state in which the input shaft 22 and the pinion shaft 31 are mechanically disconnected. is there. In the engaged state, the steering torque generated on the input shaft 22 by the steering wheel 21 can be transmitted to the pinion shaft 31. On the other hand, in the released state, the steering torque generated on the input shaft 22 by the steering of the steering wheel 21 cannot be transmitted to the pinion shaft 31.

  Detection signals detected by the steering torque sensor 23, the steering angle sensor 24, the motor rotation angle sensor 27, and the pinion shaft rotation angle sensor 41 are sent to the control unit 51. In addition to these, the controller 51 includes a vehicle speed sensor 52 that detects the traveling speed of the vehicle, a yaw rate sensor 53 that detects the yaw angular velocity (angular velocity of the yaw motion), an acceleration sensor 54 that detects the acceleration of the vehicle, and other various types. Each sensor 55 receives a detection signal. The control unit 51 receives detection signals from these sensors and issues control signals to the reaction force motor 26, the turning power motor 45, and the clutch mechanism 80.

  The vehicle steering device 10 is in a released state during normal times. That is, even if the steering wheel 21 is steered, the steering torque generated on the input shaft 22 is not transmitted to the pinion shaft 31. In this case, the steering actuator 38 generates steering power according to the steering amount of the steering wheel 21. This turning power is transmitted to the rack shaft 34 and the turning wheels 35 and 35 are turned.

  The vehicle steering device 10 is in a fastening state in an emergency. The input shaft 22 and the pinion shaft 31 are mechanically connected by the clutch mechanism 80. Therefore, the steering torque generated by steering the steering wheel 21 is transmitted from the input shaft 22 to the pinion shaft 31 via the planetary gear mechanism 140 and the clutch mechanism 80. Due to the steering torque transmitted to the pinion shaft 31, the rack shaft 34 is displaced in the left-right direction, and the steered wheels 35, 35 are steered. A more specific configuration will be described with reference to FIG.

  FIG. 2 shows the clutch mechanism 80 in the released state. As shown in FIG. 2, the pinion shaft 31 is rotatably supported by a lower needle roller bearing 62 and a lower ball bearing 63 attached to the lower housing 61. A middle housing 64 is overlaid on the upper portion of the lower housing 61. The middle housing 64 accommodates the main part of the clutch mechanism 80. An upper housing 65 is overlaid on the upper portion of the middle housing 64. The upper housing 65 accommodates the main part of the planetary gear mechanism 140. The lower housing 61, the middle housing 64, and the upper housing 65 are fastened by bolts 66.

  Referring also to FIG. 3, the clutch mechanism 80 includes a gear-shaped lock wheel 90 that is rotatably supported by a middle ball bearing 67 attached to the pinion shaft 31, and a first mechanism that regulates the rotation of the lock wheel 90. 1 and second locking means 100 and 120.

  Returning to FIG. 2, the planetary gear mechanism 140 rotates and revolves around the sun gear 141 that is disposed above the lock wheel 90 and is integrally formed with the lock wheel 90 via the connection cylinder portion 161. A possible planetary gear 150, a planetary carrier 144 that supports the planetary gear 150 and is connected to the upper end of the pinion shaft 31, and an input shaft 22 is integrally formed at the upper end so as to cover the outer periphery of the planetary carrier 144. Ring gear 145.

  The planetary carrier 144 is press-fitted into the pinion shaft 31. The sun gear 141 is supported by the pinion shaft 31 via the middle ball bearing 67 and also supported by the planetary carrier 144 via the first upper ball bearing 72. More specifically, the sun gear 141 is supported by the first upper ball bearing 72 and the middle ball bearing 67. The first upper ball bearing 72 is supported by the planetary carrier 144. The middle ball bearing 67 is supported by the pinion shaft 31. The planetary carrier 144 can rotate around the axis line CL1 together with the pinion shaft 31.

  A second upper ball bearing 73 is provided between the outer peripheral surface of the ring gear 145 and the inner peripheral surface of the upper housing 65. Further, a third upper ball bearing 74 is provided between the outer peripheral surface of the input shaft 22 and the inner peripheral surface of the upper housing 65. Both the ring gear 145 and the input shaft 22 are rotatable around the axis line CL1. A seal 75 is provided at the upper end of the upper housing 65 along the outer peripheral surface of the input shaft 22 to prevent entry of dust and the like.

  The centers of the pinion shaft 31, the lock wheel 90, the connecting cylinder 161, the sun gear 141, the planetary carrier 144, the ring gear 145, and the input shaft 22 are located on the axis CL1. The axis lines CL1 of the pinion shaft 31, the lock wheel 90, the connecting cylinder portion 161, the sun gear 141, the planetary carrier 144, the ring gear 145, and the input shaft 22 coincide with each other.

  With reference to the direction in which the axis line CL1 extends, the height of the portion P1 where the middle housing 64 and the upper housing 65 are overlapped with the height of the connecting tube portion 161.

  As shown in FIG. 3, the lock wheel 90 has eight teeth 92 formed at equal intervals from the substantially disc-shaped wheel body 91 toward the outer periphery, and the teeth 92 are located in the middle between the teeth 92 and the teeth 92. Eight low teeth 93 having a low height are formed. Between the teeth 92 and the low teeth 93, the outer peripheral surface portion 91a of the wheel body 91 faces. In summary, teeth 92, an outer peripheral surface portion 91a, low teeth 93, and an outer peripheral surface portion 91a are repeatedly formed at equal intervals on the outer periphery of the lock wheel 90. The circumferential lengths of the teeth 92, the outer peripheral surface portion 91a, and the low teeth 93 are substantially the same.

  The first locking means 100 includes a first support shaft 101 provided on the periphery of the lock wheel 90, and a first lock arm 102 (lock arm) attached to the first support shaft 101 so as to be swingable. 102), a first torsion coil spring 103 (biasing member 103) that urges the first lock arm 102 toward the lock wheel 90, and a swing toward the middle housing 64 side of the first lock arm 102. A first swing regulating pin 104 that regulates the movement, a second support shaft 106 provided on the periphery of the lock wheel 90, and a second lock arm attached to the second support shaft 106 so as to be swingable. 107 (lock arm 107) and a second torsion coil spring for urging the second lock arm 107 toward the lock wheel 90 08 (the urging member 108), the second swing restriction pin 109 for restricting the swing toward the middle housing 64 side of the second lock arm 107, and the first and second lock arms 102 and 107. And a first solenoid 111 (solenoid 111) having a possible first rod 111a (rod 111a). The first solenoid 111 is attached to the outer wall 64 a of the middle housing 64 by bolts 113 and 113.

  The basic structure of the second locking means 120 is the same as that of the first locking means 100. The second locking means 120 includes a third support shaft 121 provided on the periphery of the lock wheel 90, and a third lock arm 122 (lock arm) attached to the third support shaft 121 so as to be swingable. 122), a third torsion coil spring 123 (biasing member 123) that urges the third lock arm 122 toward the lock wheel 90, and a swing toward the middle housing 64 side of the third lock arm 122. A third swing restricting pin 124 that restricts the movement, a fourth support shaft 126 provided on the periphery of the lock wheel 90, and a fourth lock arm that is swingably attached to the fourth support shaft 126. 127 (lock arm 127) and a fourth torsion coil spring for urging the fourth lock arm 127 toward the lock wheel 90 28 (biasing member 128), a fourth swing restricting pin 129 for restricting a swing toward the middle housing 64 side of the fourth lock arm 127, and advancing and retreating toward the third and fourth lock arms 122, 127 And a second solenoid 131 (solenoid 131) having a possible second rod 131a (rod 131a). The second solenoid 131 is attached to the outer wall portion 64 a of the middle housing 64 by bolts 133 and 133.

  Returning to FIG. 3, the first lock arm 102 has a first arm main body portion 102 b in which the tip end portion 102 a abuts on the lock wheel 90 and a direction away from the tip end portion 102 a based on the first support shaft 101. The extending first receiving portion 102c is integrally formed.

  The basic configuration of the second to fourth lock arms 107, 122, and 127 is the same as that of the first lock arm 102, and a detailed description thereof is omitted. The second lock arm 107 includes a second arm main body portion 107b having a tip portion 107a and a second receiving portion 107c. The third lock arm 122 includes a third arm main body 122b having a distal end portion 122a and a third receiving portion 122c. The fourth lock arm 127 includes a fourth arm main body 127b having a distal end portion 127a and a fourth receiving portion 127c.

  The first torsion coil spring 103 is wound around the first support shaft 101. One end 103 a of the first torsion coil spring 103 extends in a direction away from the lock wheel 90 and abuts against the middle housing 64. The other end 103 b of the first torsion coil spring 103 is in contact with the first receiving portion 102 c and urges the first receiving portion 102 c in a direction away from the lock wheel 90. The first arm main body portion 102b extending from the first support shaft 101 to the opposite side of the first receiving portion 102c is urged toward the lock wheel 90.

  The basic configuration of the second to fourth torsion coil springs 108, 123, and 128 is the same as that of the first torsion coil spring 103. One ends 108 a, 123 a, 128 a of the second to fourth torsion coil springs 108, 123, 128 are in contact with the middle housing 64, respectively. The other ends 108b, 123b, 128b of the second to fourth torsion coil springs 108, 123, 128 are in contact with the second to fourth receiving portions 107c, 122c, 127c, respectively.

  As shown in FIG. 2, the middle ball bearing 67, the lock wheel 90, and the first lock arm 102 are disposed on the axis CL2 of the first rod 111a. That is, in the height direction, the middle ball bearing 67, the lock wheel 90, the first lock arm 102, and the first rod 111a coincide. The same applies to the second lock arm (FIG. 3, reference numeral 107).

  Referring also to FIG. 3, the height of the axis CL2 of the first rod 111a and the height of the axis CL3 of the second rod 131a also coincide. The third and fourth lock arms 122 and 127 coincide with the axis CL3 of the second rod 131a in the height direction. For this reason, in the height direction, the middle ball bearing 67, the lock wheel 90, the third and fourth lock arms 122 and 127, and the second rod 131a coincide with each other.

  The axis CL2 of the first rod 111a intersects with the axis CL3 of the second rod 131a on the axis CL1 of the pinion shaft 31.

  As shown in FIG. 4, the planetary gear 150 includes a gear shaft 151 that is fixed to the planetary carrier 144 and cannot rotate, a thrust ball bearing 152 provided on the outer periphery of the gear shaft 151, and the thrust ball bearing 152. Needle roller bearing 153 provided on the upper surface, gear body 154 provided on the outer periphery of needle roller bearing 153 and having a plurality of teeth formed on the outer periphery, and provided on the upper surface of gear body 154 And a washer 155.

  Above the gear shaft 151 of the planetary gear 150, a flat washer 162 passed through the pinion shaft 31 faces. A C ring 163 fixed to the pinion shaft 31 faces a position close to the top of the flat washer 162. The plain washer 162 is restricted from being displaced upward by the C ring 163. The gear shaft 151 is prevented from being pulled upward by the C ring 163 via the plain washer 162.

  The ring gear 145 includes a ring gear main body 145a with which the gear main body 154 of the planetary gear 150 is engaged, and a step portion 145b formed by a plurality of steps so that the diameter decreases upward from the ring gear main body 145a.

  As shown in FIG. 5, the first and second solenoids 111 and 131 do not receive a lock signal (see FIG. 1, Cn) from the control unit (FIG. 1, reference numeral 51) in a normal state. In a state where no lock signal is received, the first and second solenoids 111 and 131 are in an excited state. At this time, the first and second rods 111a and 131a are in the advanced positions. The first to fourth lock arms 102, 107, 122, 127 are restricted from swinging toward the lock wheel 90 by the first or second rods 111 a, 131 a being in contact with each other. Thereby, the lock wheel 90 is in a rotatable state. The sun gear 141 integrated with the lock wheel 90 is also rotatable (is idle).

  By steering the steering wheel 21, the ring gear 145 rotates through the input shaft 22. This rotational force is transmitted to the sun gear 141 through the planetary gear 150. Since the sun gear 141 is rotatable, the planetary gear 150 only rotates on the spot. That is, it does not revolve around the sun gear 141. For this reason, the planetary carrier 144 does not rotate, and the steering force is hardly transmitted from the input shaft 22 to the pinion shaft 31.

  Thus, in the normal state, the planetary gear mechanism 140 is in an open state. When the steering wheel 21 is steered, the control unit (FIG. 1, reference numeral 51) shown in FIG. 1 controls the turning power motor (FIG. 1, reference numeral 45), so that the running state of the vehicle is controlled by the steering mechanism 30. It is possible to steer the steered wheels 35 and 35 with the optimum steering characteristics according to the above.

  Thereafter, when the electrical connection between the steering mechanism 20 and the steering mechanism 30 is released due to some factor, or when the ignition key switch is turned off, the control unit (FIG. 1, reference numeral 51) indicates a lock signal. To emit.

  As shown in FIG. 6, in an emergency, the first and second solenoids 111 and 131 are in a non-excited state upon receiving a lock signal. As a result, the first and second rods 111a and 131a retreat. As a result, the first and second rods 111 a and 131 a are separated from the first to fourth lock arms 102, 107, 122, and 127. The first to fourth lock arms 102, 107, 122, 127 swing toward the lock wheel 90 by the urging force of the first to fourth coil springs 103, 108, 123, 128.

  Any one of the first to fourth lock arms 102, 107, 122, 127 abuts on the teeth 92 of the lock wheel 90 and restricts the rotation of the lock wheel 90. At this time, the rotation of the sun gear 141 integrated with the lock wheel 90 is also restricted. The figure shows a state in which the first lock arm 102 abuts against the teeth 92 of the lock wheel 90 and the rotation of the lock wheel 90 is restricted. On the other hand, the second to fourth lock arms 107, 122, 127 are in contact with the lock wheel 90 at positions where the lock wheel 90 is allowed to rotate.

  Thus, when the clutch mechanism 80 receives the lock signal, the clutch mechanism 80 locks the sun gear 141 in a stopped state, thereby bringing the planetary gear mechanism 140 into a connected state. That is, when the electrical connection is released, the backup system is automatically switched.

  As shown in FIG. 7, by steering the steering wheel 21, the ring gear 145 rotates, and the rotational force is transmitted to the planetary gear 150. At this time, the rotation of the sun gear 141 is restricted. For this reason, the planetary gear 150 revolves while rotating around the sun gear 141. As the sun gear revolves, the planetary carrier 144 rotates. The pinion shaft 31 connected to the planetary carrier 144 rotates to steer the steered wheels 35 and 35 via the rack and pinion mechanism 33. The steering force of the steering wheel 21 can be mechanically transmitted to the steering mechanism 30 via the planetary gear mechanism 140. In this case, the reaction force motor 26 does not generate a steering reaction force.

  Returning to FIG. 4, the planetary gear 144 includes a gear shaft 151 fixed to the planetary carrier 144, a thrust ball bearing 152 (thrust bearing) provided on the outer periphery of the gear shaft 151, and an upper surface of the thrust ball bearing 152. And a needle roller bearing 153 provided on the outer periphery of the gear shaft 151 and a plurality of teeth formed on the outer periphery of the needle roller bearing 153 and on the upper surface of the thrust ball bearing 152. The gear main body 154 and a washer 155 provided on the upper surface of the gear main body 154.

  When the gear main body 154 rotates, resistance due to friction is inevitably generated between the gear main body 154 and the gear shaft 151 or between the gear main body 154 and each part of the planetary carrier 144. Referring also to FIG. 5, even if the sun gear 141 is in the idling state, the planetary gear 150 may slightly revolve due to the influence of friction. Thereby, the planetary carrier 144 rotates and the pinion shaft 31 also rotates. That is, when it is desired to prevent the pinion shaft 31 from rotating, the pinion shaft 31 may be slightly rotated.

  By providing the thrust ball bearing 152, the needle roller bearing 153, and the washer 155, it is possible to reduce the frictional resistance generated between the gear main body 154 and the gear shaft 151 or between the gear main body 154 and each part of the planetary carrier 144. it can. Thereby, rotation of the pinion shaft 31 against the intention can be suppressed, and the vehicle steering apparatus can be operated more accurately. It is particularly effective to take measures against friction of the planetary gear 144 having a high rotational speed.

  Further, a thrust ball bearing 152 is provided below the gear body 154. Thereby, the gear body 154 can be smoothly rotated while receiving the weight of the gear body 154. In addition, a washer 155 is provided above the gear body 154. While the vehicle is traveling, the gear body 154 may be displaced upward due to vibration. Even in such a case, the upper surface of the gear main body 154 can be received and smooth rotation can be ensured.

  Although the first to fourth lock arms according to the present invention have been described with examples having different shapes, the position of contact with the lock wheel is adjusted by the position where the first to fourth support shafts are provided. May be. Furthermore, these can also be combined. That is, it is only necessary for each lock arm to abut on a different position of the lock wheel with reference to the gap between the teeth of the lock wheel, and the invention is not limited to these types.

  The vehicle steering device of the present invention is suitable for being mounted on a passenger car.

DESCRIPTION OF SYMBOLS 10 ... Vehicle steering device 21 ... Steering wheel 22 ... Input shaft 31 ... Pinion shaft 33 ... Rack and pinion mechanism 34 ... Rack shaft 38 ... Steering actuator 80 ... Clutch mechanism 140 ... Planetary gear mechanism 150 ... Planetary gear 151 ... Gear shaft 152 ... Thrust ball bearings (thrust bearings)
153 ... Needle roller bearing 154 ... Gear body 155 ... Washer

Claims (1)

Steering wheel, input shaft coupled to the steering wheel, planetary gear mechanism coupled to the input shaft, clutch mechanism coupled to the planetary gear mechanism, and the planetary gear mechanism and clutch A pinion shaft connected to the input shaft via a mechanism, a rack shaft connected to the pinion shaft via a rack-and-pinion mechanism, and a direct or indirect connection to the rack shaft. A steering apparatus for a vehicle having a steering actuator that transmits steering power according to a steering amount to the rack shaft;
The planetary gear mechanism has a planetary carrier that supports a planetary gear and is connected to the pinion shaft;
The planetary gear is
A gear shaft fixed to the planetary carrier;
A thrust bearing provided on the outer periphery of the gear shaft;
A needle roller bearing provided on the upper surface of the thrust bearing and on the outer periphery of the gear shaft;
A gear body provided with an outer periphery of the needle roller bearing and an upper surface portion of the thrust bearing, and a plurality of teeth formed on the periphery;
A vehicle steering apparatus comprising a washer provided on an upper surface portion of the gear body.

Images